ALBERT

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Yang Hu, Wei-Chao Chen, Yu-Feng Shen, Bin Zhu, Gao-Xue Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viral diseases in aquaculture were challenging because there are few preventative measures and/or treatments. Our previous study indicated that imidazole arctigenin derivatives possessed antiviral activities against infectious hematopoietic necrosis virus (IHNV). Based on the structure-activity relationship in that study, a new imidazole arctigenin derivative, 4-(8-(2-ethylimidazole)octyloxy)-arctigenin (EOA), was designed, synthesized and its anti-IHNV activity was evaluated. By comparing inhibitory concentration at half-maximal activity (IC〈sub〉50〈/sub〉), we found that EOA (IC〈sub〉50〈/sub〉 = 0.56 mg/L) possessed a higher antiviral activity than those imidazole arctigenin derivatives in our previous study. Besides, EOA could significantly decrease cytopathic effect (CPE) and viral titer induced by IHNV in epithelioma papulosum cyprinid (EPC) cells. In addition, EOA significantly inhibited apoptosis induced by IHNV in EPC cells. Further data verified that EOA inhibited IHNV replication in rainbow trout, with reducing 32.0% mortality of IHNV-infected fish. The results suggested that EOA was more stable with a prolonged inhibitory half-life in the early stage of virus infection (1–4 days). Consistent with above results, EOA repressed IHNV glycoprotein gene expression in virus sensitive tissues (kidney and spleen) in the early stage of virus infection. Moreover, histopathological evaluation showed that tissues from the spleen and kidney of fish infected with IHNV exhibited pathological changes. But there were no lesions in any of the tissues from the control group and EOA-treaten group. In accordance with the histopathological assay, EOA could elicited anti-inflammation response in non-viral infected rainbow trout by down-regulating the expression of cytokine genes (〈em〉IL-8〈/em〉, 〈em〉IL-12p40〈/em〉, and 〈em〉TNF-α〈/em〉). Altogether, EOA was expected to be a therapeutic agent against IHNV infection in the field of aquaculture.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Junjun He, Haiying Liang, Jiaping Zhu, Xiaochen Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Antibacterial peptides (AMPs) constitute an important part of the body's innate immune system and are responsible for a wide range of inhibitory effects against pathogens such as bacteria, fungi, and viruses. In this study, multi-step high performance liquid chromatography (HPLC), combined with Mass Spectrometry (MS), was used to isolate and identify proteins with antibacterial activity from the serum of 〈em〉Pinctada fucata martensii〈/em〉 (〈em〉P.f. Martensii〈/em〉) and obtain a component named 〈em〉P.f. Martensii〈/em〉 antimicrobial peptide-1 (PmAMP-1). 〈em〉PmAMP-1〈/em〉 cDNA was cloned and sequenced by rapid amplification of cDNA ends (RACE) and mRNA expression of was analyzed by quantitative real-time PCR (qRT-PCR). From the results of this study, full-length 〈em〉PmAMP-1 c〈/em〉DNA was shown to be 700 base pairs (bp) long with an open reading frame (ORF) of 294 bp, encoding 97 amino acids with a predicted structure that is mostly α-helices. 〈em〉PmAMP-〈/em〉1 mRNA was constitutively expressed in all tested tissues including the adductor muscle, mantle, hepatopancreas, gill, gonads and hemocytes. The highest level of 〈em〉PmAMP-〈/em〉1 transcription was observed at 8 h and 2 h after bacterial challenge in hemocytes and adductor muscle (p 〈 0.01), respectively. Furthermore, PmAMP-1 caused significant morphological alterations in 〈em〉E. coli,〈/em〉 as shown by transmission electron microscopy (TEM). The results from this study provide a valuable base for further exploration of molluscan innate immunity and immune response.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Bin Zhong, Zeyin Jiang, Zhenhuang Chen, Kazue Ishihara, Huilin Mao, Shanghong Wang, Gang Lin, Chengyu Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, studies have shown that IκB kinase β (IKKβ), a critical kinase in the nucleus factor kappa-B (NF-κB) pathway, participates in inflammatory responses associated with unfolded protein response (UPR) and plays an important role in ER stress-induced cell death. The unfolded protein response (UPR), which is a regulatory system to restore cellular homeostasis in the endoplasmic reticulum (ER), such as oxidative stress, bacterial infection, and virus invasion. The UPR pathways have been reported to be involved in immune responses in mammals, including the classical NF-κB pathway. However, the molecular mechanism of their crosstalk remains to be elucidated. Previously, we demonstrated that IKKβ also has some conserved functions between fish and human, as grass carp (〈em〉Ctenopharyngodon idella〈/em〉) IKKβ (CiIKKβ) can activate NF-κB pathway. In this study, we found that CiIKKβ level in nucleus was elevated under ER stress and CiIKKβ can interact with grass carp X-box-binding protein 1 (CiXBP1S), a key transcription factor in UPR. Consistently, fluorescent histochemical analysis of grass carp kidney (CIK) cells indicated that CiIKKβ and CiXBP1S colocalized under ER stress. Furthermore, overexpression of CiIKKβ in CIK cells enhanced ER stress tolerance by regulating UPR signaling and resulted in the significant increase of cell viability.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Lu-Yun Ni, Qing Han, Hong-Ping Chen, Xiao-Chun Luo, An-Xing Li, Xue-Ming Dan, Yan-Wei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Macrophage expressed gene 1 (Mpeg1) is a molecule that can form pores and destroy the cell membrane of invading pathogens. In this study, we identified two Mpeg1 isoforms from the orange-spotted grouper (〈em〉Epinephelus coioides〈/em〉) and named them EcMpeg1a and EcMpeg1b. Predicted proteins of the two EcMpeg1s contained a signal peptide, a conserved membrane attack complex/perforin (MACPF) domain, a transmembrane segment, and an intracellular region. Sequence alignment demonstrated that two EcMpeg1 proteins share a high sequence identity with that of other teleosts. Tissue distribution analysis showed that EcMpeg1s were expressed in all tissues tested in healthy grouper, with the highest expression in the head kidney and spleen. After infection with the ciliate parasite 〈em〉Cryptocaryon irritans〈/em〉, expression of the two EcMpeg1s was significantly upregulated in the spleen and gills. Furthermore, the recombinant EcMpeg1a showed antiparasitic and antibacterial activity against Gram-negative and -positive bacteria, whereas EcMpeg1b had an inhibitory effect only against Gram-positive bacteria. These results indicated that EcMpeg1s play an important role in the host response against invading pathogens.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Pengfei Chu, Libo He, Cheng Yang, Wencheng Zeng, Rong Huang, Lanjie Liao, Yongming Li, Zuoyan Zhu, Yaping Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Autophagy is an essential and conserved process that plays an important role in physiological homeostasis, adaptive response to stress and the immune response. Autophagy-related proteins (ATGs) are key components of the autophagic machinery. In the study, grass carp (〈em〉Ctenopharyngodon idella〈/em〉) autophagy-related gene 5 (〈em〉ATG5〈/em〉) and 12 (〈em〉ATG12〈/em〉) were identified. In the gill and intestine, 〈em〉ATG5〈/em〉 and 〈em〉ATG12〈/em〉 were highly expressed, but after grass carp reovirus (GCRV) infection, they were decreased significantly. In 〈em〉Ctenopharyngodon idella〈/em〉 kidney (CIK) cells, the sharp variation of 〈em〉ATG5〈/em〉 and 〈em〉ATG12〈/em〉 expression was observed after poly(I:C) infection. Subcellular localisation showed that ATG5 and ATG12 were evenly distributed in the cytoplasm and nucleus. However, the interaction between ATG5 and ATG12 was only found in cytoplasm in both 293T cells and CIK cells. In addition, the overexpression of ATG5 or ATG12 in 293T cells showed enhanced autophagy, and autophagic process was facilitated when ATG5 and ATG12 were simultaneously overexpressed. Dual-luciferase activity assay indicated that both ATG5 and ATG12 remarkably suppressed the promoter activity of 〈em〉IRF3〈/em〉, 〈em〉IRF7〈/em〉, and 〈em〉IFN-I〈/em〉. Further, ATG5 and ATG12 conjugate showed far stronger inhibitory affection on the expression of 〈em〉IFN-I〈/em〉 than either ATG5 or ATG12 in response to poly(I:C) or GCRV infection. Taken together, the results demonstrate that grass carp ATG5 and ATG12 play an important role in innate immunity and autophagy.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Chao Xu, Wen-Bin Liu, Sofie Charlotte Remø, Bing-Ke Wang, Hua-Juan Shi, Li Zhang, Jia-Dai Liu, Xiang-Fei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigated the effects of restricted feeding on the growth performance, oxidative stress and inflammation of 〈em〉Megalobrama amblycephala〈/em〉 fed high-carbohydrate (HC) diets. Fish (46.94 ± 0.04 g) were randomly assigned to four groups containing the satiation of a control diet (30% carbohydrate) and three satiate levels (100% (HC1), 80% (HC2) and 60% (HC3)) of the HC diets (43% carbohydrate) for 8 weeks. Results showed that HC1 diet remarkably decreased final weight (FW), weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), hepatic activities of total anti-oxidation capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT), the AMP/ATP ratio, the p-AMPKα/t-AMPKα ratio, sirtuin-1 (SIRT1) protein expression and hepatic transcriptions of AMPKα2, SIRT1, nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx1) and interleukin10 (IL 10) compared to the control group, whereas the opposite was true for protein efficiency ratio (PER), nitrogen retention efficiency (NRE), energy retention efficiency (ERE), plasma glucose levels, alanine transaminase (AST) and aspartate aminotransferase (ALT) activities, hepatic contents of malondialdehyde (MDA), tumour necrosis factor α (TNF α) and interleukin 1β (IL 1β), ATP and AMP contents and hepatic transcriptions of kelch-like ECH associating protein 1 (Keap1), IkB kinase α (IKK α), nuclear factor kappa B (NF-κB), TNF α, IL 1β, interleukin 6 (IL 6) and transforming growth factor β (TGF β). As for the HC groups, fish fed the HC2 diet obtained relatively high values of SGR, PER, NRE, ERE, hepatic activities of T-AOC, SOD and CAT, the AMP/ATP ratio, the p-AMPKα/t-AMPKα ratio, SIRT1 protein expression and hepatic transcriptions of AMPKα2, Nrf2, CAT, copper/zinc superoxide dismutase (Cu/Zn-SOD), Mn-SOD, GPx1, glutathione S-transferase (GST) and interleukin10 (IL 10), while the opposite was true for hepatic content of IL 6 and transcription of IKK α. Overall, an 80% satiation improved the growth performance and alleviated the oxidative stress and inflammation of blunt snout bream fed HC diets via the activation of the AMPK-SIRT1 pathway and the up-regulation of the activities and transcriptions of Nrf2-modulated antioxidant enzymes coupled with the depression of the levels and transcriptions of the NF-κB-mediated pro-inflammatory cytokines.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Jiangfan Zhang, Chuanju Dong, Junchang Feng, Junpeng Li, Shengjie Li, Jianxin Feng, Xiaodi Duan, Gaigai Sun, Peng Xu, Xuejun Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉HIFs〈/em〉 (Hypoxia inducible factors) are the main regulators of the expression change of oxygen-dependent genes, in addition, they also play important roles in immune regulation. 〈em〉HIFs〈/em〉 participate in infectious diseases and inflammatory responses, providing us a new therapeutic target for the treatment of diseases. In this study, 16 〈em〉HIFs〈/em〉 were identified in common carp genome database. Comparative genomics analysis showed large expansion of 〈em〉HIF〈/em〉 gene family and approved the four round whole genome duplication (WGD) event in common carp. To further understand the function of 〈em〉HIFs〈/em〉, the domain architectures were predicted. All HIF proteins had the conserved HLH-PAS domain, which were essential for them to form dimer and bind to the downstream targets. The differences in domain of HIFα and HIFβ might result in their different functions. Phylogenetic analysis revealed that all 〈em〉HIFs〈/em〉 were divided into two subfamilies and the 〈em〉HIFs〈/em〉 in common carp were clustered with their teleost counterparts indicating they are highly conservative during evolution. In addition, the tissue distribution was examined by RT-PCR showed that most of 〈em〉HIF〈/em〉 genes had a wide range of tissue distribution but exhibited tissue-specific expression patterns. The expression divergences were observed between the copy genes, for example, 〈em〉HIF1A-1〈/em〉, 〈em〉HIF2A-1〈/em〉, 〈em〉ARNT-〈/em〉2 had wide tissue distribution while their copies had limited tissue distribution, proving the function divergence of copies post the WGD event. In order to find an effective activation of 〈em〉HIFs〈/em〉 and apply to treatment of aquatic diseases, we investigate the dietary supplementation effects of different strains of 〈em〉Lactococcus lactis〈/em〉 on the expression of 〈em〉HIFα〈/em〉 subfamily members in kidney of common carp infected with 〈em〉A. hydrophila〈/em〉. In addition, all of the 〈em〉HIF〈/em〉 genes have a high expression in the early stages of infection, and decreased in the treatment time point of 48 h in common carp. This phenomenon confirms that as a switch, the main function of 〈em〉HIFs〈/em〉 is to regulate the production of immune response factors in early infection. So activation of the switch may be an effective method for infectious disease treatment. As expected, the treatment groups improved the expression of 〈em〉HIFs〈/em〉 compared with the control group, and the effects of the three strains are different. The strain1 of 〈em〉L. lactis〈/em〉 had a stronger induction on 〈em〉HIF〈/em〉 genes than strain2 and strain3, and it might be applied as a potential activation of 〈em〉HIF〈/em〉 genes for disease treatment. So, adding befitting 〈em〉L. lactis〈/em〉 maybe a well method to activate the 〈em〉HIF〈/em〉 genes to protect them from mycobacterial infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): K.A.S.N. Shanaka, M.D. Neranjan Tharuka, Thanthrige Thiunuwan Priyathilaka, Jehee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viperin, also known as RSAD2 (Radical S-adenosyl methionine domain containing 2), is an interferon-induced endoplasmic reticulum-associated antiviral protein. Previous studies have shown that viperin levels are elevated in the presence of viral RNA, but it has rarely been characterized in marine organisms. This study was designed to functionally characterize rockfish viperin (〈em〉SsVip〈/em〉), to examine the effects of different immune stimulants on its expression, and to determine its subcellular localization. SsVip is a 349 amino acid protein with a predicted molecular mass of 40.24 kDa. It contains an S-adenosyl 〈span〉l〈/span〉-methionine binding conserved domain with a CNYKCGFC sequence. Unchallenged tissue expression analysis using quantitative real time PCR (qPCR) revealed 〈em〉SsVip〈/em〉 expression to be the highest in the blood, followed by the spleen. When challenged with poly I:C, 〈em〉SsVip〈/em〉 was upregulated by approximately 60-fold in the blood after 24 h, and approximately 50-fold in the spleen after 12 h. Notable upregulation was detected throughout the poly I:C challenge experiment in both tissues. Significant expression of 〈em〉SsVip〈/em〉 was detected in the blood following 〈em〉Streptococcus iniae〈/em〉 and lipopolysaccharide challenge, and viral hemorrhagic septicemia virus (VHSV) gene transcription was significantly downregulated during SsVip overexpression. Furthermore, cell viability assay and virus titer quantification with the presence of SsVip revealed a significant reduction in virus replication. As with previously identified viperin counterparts, SsVip was localized in the endoplasmic reticulum. Our findings show that SsVip is an antiviral protein crucial to innate immune defense.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jing Li, Zhi-Bin Wu, Zhao Zhang, Ji-Wei Zha, Shen-Ye Qu, Xiao-Zhou Qi, Gao-Xue Wang, Fei Ling〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nowadays, there is no suitable treatment for vibriosis in groupers. So an eco-efficient and environmentally friendly treatment is necessary for the grouper industry. Probiotic-feeding has been a promising strategy to control the bacterial pathogens in aquaculture. A new 〈em〉Bacillus velezensis〈/em〉 strain named K2 was isolated from the intestinal tract of healthy grouper, and exhibited wide antimicrobial spectrum of against fish pathogens, including 〈em〉Vibrio harveyi〈/em〉, 〈em〉Vibrio alginolyticus〈/em〉, 〈em〉Aeromonas hydrophila〈/em〉, 〈em〉Aeromonas veronii〈/em〉, 〈em〉Aeromonas caviae〈/em〉, 〈em〉Enterococcus casseliflavus〈/em〉 and 〈em〉Lactococcus garvieae〈/em〉. Moreover, results of the safety of 〈em〉B. velezensis〈/em〉 K2 showed that intraperitoneal injection of K2 in healthy grouper did not cause any pathological abnormality or death, indicating this bacteria could be considered as a candidate probiotic in aquaculture. Groupers were fed with the diets containing 1 × 10〈sup〉7〈/sup〉 cfu/g of 〈em〉B. velezensis〈/em〉 K2 for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that diets supplemented with K2 significantly increased serum acid phosphatase (ACP) activity (〈em〉P〈/em〉 〈 0.05). Results of the mRNA expression of immune-related genes in the head kidney of hybrid grouper showed that the expression of lysozyme gene was significantly upregulated after 1 and 2 weeks of feeding (〈em〉P〈/em〉 〈 0.05). A significant up-regulation of the expression of piscidin, IgM and MyD88 were detected at day 21, whereas the TLR3 and TLR5 showed lower expression compared to the controls during 21 days, and a significant decrease of TLR3 gene was found at day 28 (〈em〉P〈/em〉 〈 0.05). After challenge with 〈em〉V. harveyi〈/em〉, the survival rate of fish administrated with the strain K2 for 28 days was signifiacantly higher than the controls without this strain (〈em〉P〈/em〉 〈 0.05). These results collectively suggest that 〈em〉B. velezensis〈/em〉 K2 is a potential probiotic species to improve health status and disease resistance and can be developed as a probiotic agent in grouper industry.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Phennapa Promthale, Pattira Pongtippatee, Boonsirm Withyachumnarnkul, Kanokpan Wongprasert〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fishmeal is the main source of protein in the shrimp feed industry and is normally derived from trash fish. As such, the production of fishmeal has an adverse effect on the marine environment by taking away small and juvenile fish, leading to depletion of marine species. There is a need for alternative sources of protein which will substitute fishmeal in the aquaculture industry. This study evaluated the components and nutritional efficacy of bioflocs, which were used to substitute fishmeal protein. The effect of bioflocs diets on growth performance, survival rate, and immune response in shrimp compared to normal fishmeal feed were determined. Bioflocs were harvested from the shrimp ponds (C:N ratio 〉12:1) at Shrimp Village, Chaiya district, Surat Thani, Thailand. The total protein in bioflocs was about 48% and the total lipid was about 5% (dried weight) and the percentages of essential amino acids (EAA) and fatty acids (EFA) in bioflocs were similar to those of fishmeal feed. Shrimp fed with the different dietary bioflocs feed regimens [% to replace fishmeal; 0% (B0), 25% (B25), 50% (B50), 75% (B75), and 100% (B100)] for 42 days revealed that all growth parameters were almost similar to those of the control shrimp (shrimp fed with normal fishmeal, B0) including final body weight, weight gain, specific growth rate, and feed conversion ratio. Remarkably, the survival rates, the levels of immune parameters, and expression of immune genes (proPO-I, PEN-4 and dicer) were significantly higher in bioflocs fed shrimp, especially in B25 and B50 shrimp. Moreover, B25 and B50 bioflocs fed shrimp showed notably increased survival rates following 〈em〉Vibrio parahaemolyticus (V. parahaemolyticus)〈/em〉 infection. In conclusion, the present study demonstrates that shrimp survival and immunity are enhanced by biofiocs substituted fishmeal. Significantly, the bioflocs diets activated the immune response to prevent 〈em〉V. parahaemolyticus〈/em〉 infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Sarah J. Poynter, Shanee Herrington-Krause, Stephanie J. DeWitte-Orr〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In mammals, the multifunctional DExH/D-box helicases, DDX3 and DHX9, are nucleic acid sensors with a role in antiviral immunity; their role in innate immunity in fish is not yet understood. In the present study, full-length DDX3 and DHX9 coding sequences were identified in rainbow trout (〈em〉Oncorhynchus mykiss)〈/em〉. Bioinformatic analysis demonstrated both deduced proteins were similar to those of other species, with ~80% identity to other fish species and ~70–75% identity to mammals, and both protein sequences had conserved domains found amongst all species. Phylogenetic analysis revealed clustering of DDX3 and DHX9 with corresponding proteins from other fish. Cellular localization of overexpressed DDX3 and DHX9 was performed using GFP-tagged proteins, and endogenous DDX3 localization was measured using immunocytochemistry. In the rainbow trout gonadal cell line, RTG-2, DHX9 localized mostly to the nucleus, while DDX3 was found mainly in the cytoplasm. Tissue distribution from healthy juvenile rainbow trout revealed ubiquitous constitutive expression, highest levels of DDX3 expression were seen in the liver and DHX9 levels were fairly consistent among all tissues tested. Stimulation of RTG-2 cells revealed that DDX3 and DHX9 transcripts were both significantly upregulated by treatment with the dsRNA molecule, poly I:C. A pull-down assay suggested both proteins were able to bind dsRNA. In addition to their roles in RNA metabolism, the conserved common domains found between the rainbow trout proteins and other species having defined antiviral roles, combined with the ability for the proteins to bind to dsRNA, suggest these proteins may play an important role in fish innate antiviral immunity. Future studies on both DDX3 and DHX9 function will contribute to a better understanding of teleost immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): Ke-Cheng Zhu, Hua-Yang Guo, Nan Zhang, Bao-Suo Liu, Liang Guo, Shi-Gui Jiang, Dian-Chang Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interferon regulatory factor 8 (IRF8) increases type I IFN transcription levels by binding to IFN promoters, thereby playing a role in innate immunity. Nevertheless, the detailed mechanism through which IRF8 regulates type II IFN in fish remains ambiguous. In the present study, two genes from the golden pompano (〈em〉Trachinotus ovatus〈/em〉), 〈em〉IRF8〈/em〉 (〈em〉ToIRF8〈/em〉) and 〈em〉IFN gamma〈/em〉 (〈em〉ToIFNγ〈/em〉), were identified in the IFN/IRF-based signalling pathway. The full-length 〈em〉ToIRF8〈/em〉 cDNA was composed of 2,141 bp and encoded a 421 amino acid polypeptide; the genomic DNA was 2,917 bp in length and consisted of 8 exons and 7 introns. The putative protein showed the highest sequence identity (90–92%) with fish IRF8 and possessed a DNA-binding domain (DBD), an IRF-association domain (IAD) and a nuclear localization signal (NLS) motif consistent with those of IRF8 in other vertebrates. Furthermore, the 〈em〉ToIRF8〈/em〉 transcripts were expressed in all examined tissues of healthy fish, with higher levels observed in the central nervous and immune relevant tissues. They were upregulated by polyinosinic acid: polycytidylic acid [poly (I: C)], lipopolysaccharide (LPS) and flagellin treatments in the blood, liver, intestine and kidney. The results from assays of subcellular localization showed that 〈em〉ToIRF8〈/em〉 was localized to the cytoplasm. Moreover, to investigate whether ToIRF8 was a regulator of 〈em〉ToIFNγ〈/em〉, a promoter analysis was performed using progressive deletion mutations of 〈em〉ToIFNγ〈/em〉. The results indicated that the region from −601 bp to −468 bp includes the core promoter. Mutation analyses indicated that the activity of the 〈em〉ToIFNγ〈/em〉 promoter significantly decreased after the targeted mutation of the M1-M3 binding sites. Additionally, overexpressed 〈em〉ToIRF8〈/em〉 in vitro notably increased the expression of several IFN/IRF-based signalling pathway genes. These results suggest that 〈em〉IRF8〈/em〉 is vital in the defence of 〈em〉T. ovatus〈/em〉 against bacterial infection and contributes to a better understanding of the transcriptional mechanisms of ToIRF8 on type II IFN in fish.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Tetsuro Ikuta, Akihiro Tame, Masaki Saito, Yui Aoki, Yukiko Nagai, Makoto Sugimura, Koji Inoue, Katsunori Fujikura, Kazue Ohishi, Tadashi Maruyama, Takao Yoshida〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In symbiotic systems in which symbionts are transmitted horizontally, hosts must accept symbionts from the environment while defending themselves against invading pathogenic microorganisms. How they distinguish pathogens from symbionts and how the latter evade host immune defences are not clearly understood. Recognition of foreign materials is one of the most critical steps in stimulating immune responses, and pattern recognition receptors (PRRs) play vital roles in this process. In this study, we focused on a group of highly conserved PRRs, peptidoglycan recognition proteins (PGRPs), in the deep-sea mussel, 〈em〉Bathymodiolus septemdierum〈/em〉, which harbours chemosynthetic bacteria in their gill epithelial cells. We isolated 〈em〉B. septemdierum〈/em〉 PGRP genes 〈em〉BsPGRP-S〈/em〉 and 〈em〉BsPGRP-L〈/em〉, which encode a short- and a long-type PGRP, respectively. The short-type PGRP has a signal peptide and was expressed in the asymbiotic goblet mucous cells in the gill epithelium, whereas the long-type PGRP was predicted to include a transmembrane domain and was expressed in gill bacteriocytes. Based on these findings, we hypothesize that the secreted and transmembrane PGRPs are engaged in host defence against pathogenic bacteria and/or in the regulation of symbiosis via different cellular localizations and mechanisms.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Guilherme Rabelo Coelho, Pedro Prezotto Neto, Fernanda Cortinhas Barbosa, Rafael Silva Dos Santos, Patrícia Brigatte, Patrick Jack Spencer, Sandra Coccuzzo Sampaio, Fernanda D’Amélio, Daniel Carvalho Pimenta, Juliana Mozer Sciani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Stingrays skin secretions are largely studied due to the human envenoming medical relevance of the sting puncture that evolves to inflammatory events, including necrosis. Such toxic effects can be correlated to the biochemical composition of the sting mucus, according to the literature. Fish skin plays important biological roles, such as the control of the osmotic pressure gradient, protection against mechanical forces and microorganism infections. The mucus, on the other hand, is a rich and complex fluid, acting on swimming, nutrition and the innate immune system. The elasmobranch's epidermis is a tissue composed mainly by mucus secretory cells, and marine stingrays have already been described to present secretory glands spread throughout the body. Little is known about the biochemical composition of the stingray mucus, but recent studies have corroborated the importance of mucus in the envenomation process. Aiming to assess the mucus composition, a new non-invasive mucus collection method was developed that focused on peptides and proteins, and biological assays were performed to analyze the toxic and immune activities of the 〈em〉Hypanus americanus〈/em〉 mucus. Pathophysiological characterization showed the presence of peptidases on the mucus, as well as the induction of edema and leukocyte recruitment in mice. The fractionated mucus improved phagocytosis on macrophages and showed antimicrobial activity against 〈em〉T. rubrumç. neoformans〈/em〉 and 〈em〉C. albicans in vitro〈/em〉. The proteomic analyses showed the presence of immune-related proteins like actin, histones, hemoglobin, and ribosomal proteins. This protein pattern is similar to those reported for other fish mucus and stingray venoms. This is the first report depicting the 〈em〉Hypanus〈/em〉 stingray mucus composition, highlighting its biochemical composition and importance for the stingray immune system and the possible role on the envenomation process.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Mariana Maluli Marinho de Mello, Camila de Fátima Pereira de Faria, Fábio Sabbadin Zanuzzo, Elisabeth Criscuolo Urbinati〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we show that β-glucan can modulate cortisol release in fish. We simulated a common situation in aquaculture: the transport of fish followed by contact with an opportunistic pathogen and observed what effect glucan had on the immune and stress response in these conditions. Pacu (〈em〉Piaractus mesopotamicus〈/em〉) were fed with a diet containing β-glucan (0.1%) for 15 days prior to transport followed by an injection with heat-killed 〈em〉Aeromonas hydrophila.〈/em〉 We sampled fish before transport, at arrival and at 3 and 24 h after bacterial injection. β-Glucans are used in aquaculture and have a known immunostimulatory effect, which was observed in this study. The results showed that β-glucan modulated the plasma cortisol levels differently by increasing these levels up to 24 h after transport and preventing the increase caused by bacterial inoculum injection. In addition, β-glucan enhanced the activity of the complement system at 24 h and reduced the monocytes and lymphocytes number in peripheral blood at 3 and 24 h after bacterial inoculation. Our results suggest that β-glucan modulated a bidirectional interaction between the stress and the immune responses. The modulation of cortisol levels and the immunostimulation by β-glucan at different moments in our study suggest the compound has a protective effect by avoiding higher levels of the hormone and improving resistance against bacterial infection in pacu. These results add evidence to support the use of β-glucan as an immunomodulator in the aquaculture industry.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Min Sun Kim, Ki Hong Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although the type I interferon-mediated increase of Mx1 and ISG15 gene expression in Epithelioma papulosum cyprini (EPC) cells has been reported, the antiviral role of Mx1 and ISG15 in EPC cells has not been investigated. In this study, to know the anti-viral hemorrhagic septicemia virus (VHSV) role of Mx1 and ISG15 of EPC cells, either Mx1 or ISG15 gene was knocked-out using a CRISPR/Cas9 system, and the progression of cytopathic effects (CPE) and viral growth were analyzed. Mx1 gene and ISG15 gene knockout EPC cells were successfully produced via CRISPR/Cas9 coupled with a single-cell cloning. Through the sequence analysis, one clone showing two heterozygous indel patterns in Mx1 gene and a clone showing three heterozygous indel patterns in ISG15 gene were selected for further analyses. Mx1 knockout EPC cells did not show any differences in VHSV-mediated CPE progression, even when pre-treated with polyinosinic:polycytidylic acid (poly I:C), compared to control EPC cells. These results suggest that Mx1 in EPC cells may be unfunctional to cytoplasmic RNA viruses. In contrast to Mx1, ISG15 knockout cells showed clearly hampered anti-VHSV activity even when pre-treated with poly I:C, indicating that ISG15 plays an important role in type I interferon-mediated anti-viral activity in EPC cells, which allowed VHSV to replicate more efficiently in ISG15 knockout cells than Mx1 knockout and control cells.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): José Luis Sánchez-Salgado, Mohamed Alí Pereyra, Concepción Agundis, Montserrat Calzada-Ruiz, Erika Kantun-Briceño, Edgar Zenteno〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In crustaceans, it has been suggested that specific protection against pathogens could be triggered by vaccines and biological response modifiers; although the specific mechanisms of this protection have not been clarified yet. In the crayfish 〈em〉Cherax quadricarinatus〈/em〉, a humoral lectin (CqL) binds its own granular hemocytes through a specific receptor (CqLR) and increases the production of reactive oxygen species (ROS). In the present study, we challenged 〈em〉in vivo〈/em〉 crayfishes with immunostimulants, β-glucan (200 μg/kg) or LPS (20 μg/kg), and identified the participation of cellular and humoral mechanisms. The stimulants generated a complex modification in the total hemocytes count (THC), as well as in the proportion of hemocyte subsets. At 2 h after the challenge, the largest value in THC was observed in either challenged crayfishes. Furthermore, at the same time, hyaline hemocytes were the most abundant subset in the hemolymph; after 6 h, granular hemocytes (GH) were the most abundant hemocyte subset. It has been observed that a specific subset of GH possesses a CqLR that has been related to ROS production. After 2 and 6 h of the β-glucan challenge, a significant increase in CqLR expression was observed in the three circulating hemocyte subsets; also, an increased expression of CqL was detected in a granular hemocytes sub-population. After 2 and 6 h of stimulation, the specific activity of the serum lectin challenged with β-glucan was 250% and 160% higher than in the LPS-treated-group, respectively (〈em〉P〈/em〉 〈 0.05). Hemocytes from challenged crayfishes were stimulated 〈em〉ex vivo〈/em〉 with CqL, ROS production was 180% higher in hemocytes treated with β-glucan + CqL than in hemocytes treated with LPS + CqL (〈em〉P〈/em〉 〈 0.05). The results evidence the effectivity of immune stimulators to activate specific crayfish defense mechanisms, the participation of CqL and its receptor (CqLR) could play an important role in the regulation of immune cellular functions, like ROS production, in 〈em〉Cherax quadricarinatus〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Nikolai Mugue, Nadezhda Terekhanova, Sergey Afanasyev, Aleksei Krasnov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sturgeons represent a substantial scientific interest due to their high economic value, endangered status and also as the most primitive group of ray-finned fishes. Rapid progress in knowledge of sturgeon immunity was achieved recently with use of RNA sequencing. We report transcriptome sequencing of gill, head kidney, and spleen of bester sturgeon (a hybrid of beluga 〈em〉Huso huso〈/em〉 and sterlet 〈em〉Acipen〈/em〉s〈em〉er ruthenus〈/em〉) injected with synthetic double-stranded RNA (polyI:C). The composition of transcriptome and responses to treatment were examined in the context of comparative genomics with focus on immune genes. Sturgeon transcripts matched to 21.5 k different proteins (blastx). With reference to Atlantic salmon, the functional groups and pathways of the immune system were uniformly represented: at average 36.5 ± 0.8% genes were found. Immune genes comprise a significant fraction of transcriptome. Among twenty genes with highest transcription levels, five are specialized immune genes and two encode heme and iron binding proteins (〈em〉serotransferrin〈/em〉 and 〈em〉hemopexin〈/em〉) also known as acute phase proteins. Challenge induced multiple functional groups including apoptosis, cell cycle and a number of metabolic pathways. Treatment stimulated innate antiviral immunity, which is well conserved between sturgeon and salmon, the most responsive genes were 〈em〉mx, rsad2 (viperin)〈/em〉, 〈em〉interferon induced protein 44〈/em〉 and 〈em〉protein with tetratricopeptide repeats 5〈/em〉, 〈em〉cd87〈/em〉 and 〈em〉receptor transporting protein 3〈/em〉. Results added to knowledge of immune phylogeny. Gain and loss of genes was assessed by comparison with genomes from different phylogenetic groups. Among differentially expressed genes, percentage of acquired and lost genes was much lower in comparison with genes present in all vertebrates. Innate antiviral immunity was subject to the greatest changes in evolution of jawed vertebrates. A significant fraction of genes (15%) was lost in mammals and only half of genes is annotated in public databases as involved in antiviral responses. Change of function may have an important role in evolution of immunity together with gain and loss of genes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Malene Soleng, Lill-Heidi Johansen, Hanne Johnsen, Gunhild S. Johansson, Mette W. Breiland, Lisbeth Rørmark, Karin Pittman, Lars-Flemming Pedersen, Carlo C. Lazado〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Peracetic acid (PAA), a strong organic peroxide, is considered a relatively sustainable disinfectant in aquaculture because of its broad effectivity against many pathogens at low concentrations and because it degrades spontaneously to harmless residues. The impacts of PAA on fish health must be determined before its use as either a routine disinfectant or chemotherapeutant. Here we investigated the systemic and mucosal stress responses of Atlantic salmon (〈em〉Salmo salar〈/em〉) to PAA. In experiment 1, salmon were exposed to different nominal concentrations (0, 0.6, and 2.4 ppm) of PAA for 5 min, followed by a re-exposure to the same concentrations for 30 min 2 weeks later. Sampling was performed before exposure to PAA and at 2 h, 48 h, and 2 w after exposures. In experiment 2, fish were subjected to crowding stress prior to PAA exposure at 4.8 ppm for 30 min. The fish were sampled before exposure and 1 h, 4 h, and 2 w after. The two trials were performed in a recirculation system. Both systemic (i.e., plasma cortisol, glucose, lactate, total antioxidant capacity) and mucosal (i.e., expression of antioxidant coding genes in the skin and gills) stress indicators were affected by the treatments at varying levels, and it was apparent that the fish were able to mount a robust response to the physiological demands of PAA exposure. The cortisol levels increased in the early hours after exposure and returned to basal level afterwards. Prior exposure history to PAA did not markedly affect the levels of plasma lactate and glucose when fish were re-exposed to PAA. Crowding stress before PAA treatment, however, did alter some of the stress indicators (i.e., lactate, glucose and expression of antioxidant genes in the gills), suggesting that stress history serves as both a confounding and compounding factor on how stress responses to PAA are mobilised. Nonetheless, the changes were not substantial. Gene expression profile analyses revealed that the antioxidant system was more responsive to PAA in the gills than in the skin. The increased antioxidant capacity in the plasma, particularly at 2.4 ppm and higher, indicates that antioxidants were produced to neutralise the internal redox imbalance resulting from PAA exposure. In conclusion, the results show that salmon were able to mount a robust adaptive response to different PAA doses and exposure times, and a combined exposure to stress and PAA. These results underscore the potential of PAA as a chemotherapeutant for salmon at PAA concentrations commonly applied to control parasitic infestations.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Zhiwei Cao, Sijia Liu, Hao Nan, Kaixia Zhao, Xiaodong Xu, Gaoxue Wang, Hong Ji, Hongying Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cyprinid herpesvirus 2 (CyHV-2) is the causative pathogen of herpesviral haematopoietic necrosis disease, which has caused huge economic losses to aquaculture industry in China. In this study, nine truncated CyHV-2 membrane glycoproteins (ORF25, ORF25C, ORF25D, ORF30, ORF124, ORF131, ORF136, ORF142A, ORF146) and a GFP reporter protein were respectively expressed using baculovirus surface displaying system. Western blot showed that the proteins were successfully packaged in the recombinant virus particles. In baculovirus transduced gibel carp kidney cells, the target proteins were expressed and displayed on the fish cell surface. Healthy gibel carp were immunized by immersion with the recombinant baculoviruses and the fish treated with phosphate-buffered saline (PBS) were served as mock group. The expression of 〈em〉interleukin-11〈/em〉 (〈em〉IL-11〈/em〉), 〈em〉interferon α〈/em〉 (〈em〉IFNα〈/em〉) and a complement component gene 〈em〉C3〈/em〉 were significantly up-regulated in most experimental groups, and 〈em〉interferon γ〈/em〉 (〈em〉IFNγ〈/em〉) expression in some groups were also induced after immunization. Subsequently, the immunized gibel carp were challenged by intraperitoneal injection of CyHV-2 virus. All the immunized groups exhibited reduced mortality after CyHV-2 challenge. In the groups immunized with baculoviruses displaying and expressing ORF25, ORF25C and ORF146, the relative percentage survival values reached 83.3%, 87.5% and 70.8%, respectively. Our data suggested that baculovirus-displayed ORF25, ORF25C and ORF146 could be potential vaccine candidates for the prevention of CyHV-2 infection in gibel carp.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Armando Vega-López, Nataraj S. Pagadala, Brenda P. López-Tapia, Ruth L. Madera-Sandoval, Erika Rosales-Cruz, Minerva Nájera-Martínez, Elba Reyes-Maldonado〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The signaling mediated by small non-proteinogenic molecules, which probably have the capacity to serve as a bridge amongst complex systems is one of the most exiting challenges for the study. In the current report, stem cells differentiation of the immune system in Nile tilapia treated with sub-basal doses of GABA evaluated as c-kit〈sup〉+〈/sup〉 and Sca-1〈sup〉+〈/sup〉 cells disappearance on pronephros, thymus, spleen and peripheral blood mononuclear cells by flow cytometry was assessed. Explanation of biological response was performed by molecular docking approach and multiparametric analysis. Stem cell differentiation depends on a delicate balance of negative and positive interactions of this neurotransmitter with receptors and transcription factors involved in this process. This in turn depends on the type of interaction with hematopoietic niche to differentiate into primordial, early or late hematopoiesis as well as from the dose delivery. In fish treated with the low doses of GABA (0.1% over basal value) primordial hematopoiesis is regulated by interaction of glutamate (Glu) with the Ly-6 antigen. Early hematopoiesis was influenced by the bond of GABA near or adjacent to turns of FLTR3-Ig-IV domain. During late hematopoiesis, negative regulation by structural modifications on PU.1/IRF-4 complex, IL-7Rα and GM-CSFR mainly prevails. Results of molecular docking were in agreement with the percentages of the main blood cells lineages estimated in pronephros by flow cytometry. Current study provides the first evidences about the role of inhibitory and excitatory neurotransmitters such as GABA and Glu, respectively with the most transcriptional factors and receptors involved on hematopoiesis in adult Nile tilapia.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1050464819308320-fx1.jpg" width="266" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Xianyun Ren, Yunbin Zhang, Ping Liu, Jian Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study aimed to use isobaric tags (IBTs) to investigate the immune response of the hepatopancreas of 〈em〉Marsupenaeus japonicas〈/em〉 infected with 〈em〉Vibrio parahaemolyticus〈/em〉 or white spot syndrome virus (WSSV). Liquid chromatography-tandem mass spectrometry and protein sequencing identified 1005 proteins. Among them, 109 proteins were upregulated and 94 were downregulated after 〈em〉V. parahaemolyticus〈/em〉 infection. After WSSV infection, 130 proteins were identified as differentially abundant, including 88 that were upregulated and 42 were downregulated. Fifty-four proteins were identified as differentially abundant after both 〈em〉V. parahaemolyticus〈/em〉 and WSSV infection. A number of proteins related to cytoskeletal processes, including actin and myosin, and apoptosis-related proteins were upregulated in shrimp after 〈em〉V. parahaemolyticus〈/em〉 and WSSV infection, indicating that phagocytosis and apoptosis may be involved in the response to in 〈em〉V. parahaemolyticus〈/em〉 or WSSV infection. Quantitative real-time PCR was carried out to verify the reliability of the proteomic data. These data provide a basis to characterize the immunity-related processes of shrimp in response to infection with WSSV or 〈em〉V. parahaemolyticus〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): Jiajia Yu, Hongxia Wang, Xin Yue, Baozhong Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Meretrix petechialis〈/em〉 is an important commercial aquaculture species in China. During the clam culture period, mass mortality events often occurred due to the 〈em〉Vibrio〈/em〉 infection. In this paper, 〈em〉M. petechialis〈/em〉 were challenged with 〈em〉Vibrio parahaemolyticus〈/em〉 immersion to simulate a natural infection, and the infection process were divided into four phases including latency, prodrome, onset and recovery phases based on the clam mortality data. Then, the dynamic response of clams to 〈em〉Vibrio〈/em〉 infection at different infection phases were investigated by transcriptome analysis. A total of 38,067 differentially expressed genes (DEGs) were identified at different infection phases. DEG annotations showed that immune-related and metabolism-related signaling pathways were enriched, indicating that immune defense and metabolism process play key roles during bacterial infection. Three kinds of expression pattern were classified by cluster analysis, including U-shape, L-shape and inverted V-shape. Anabolism and cellular growth proliferation related signaling pathways were repressed (long-lasting or transient) during bacterial infection. However, the immune related signaling pathways with different immune functions showed induction expression or repression expression against bacterial infection, which indicated that immune system take different strategies against bacterial infection. Furthermore, some signaling pathways such as PI3K-Akt signaling pathway both involved in immune defense and cell metabolism. This study provides a sight that the dynamic immunity and metabolic responses may be integrated to improve the host survival and shift more energy for immune defense.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Guang-hua Wang, Zhao-xia Li, En-mian Guo, Jing-jing Wang, Min Zhang, Yong-hua Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Calreticulin (CRT) is a highly conserved and multi-functional protein with diverse localizations. CRT has lectin-like properties and possesses important immunological activities in mammalian. In teleost, very limited studies on CRT immunologic function have been documented. In the present study, a CRT homologue (SsCRT) was cloned, identified and characterized from black rockfish, 〈em〉Sebastes schlegeli〈/em〉, an important aquaculture species in East Asia. The full length of 〈em〉SsCRT〈/em〉 cDNA is 2180 bp and encoded a polypeptide of 425 amino acids. SsCRT contains a signal peptide, three distinct structural and functional domains (N-, P- and C-domains), and an endoplasmic reticulum (ER) retrieval signal sequence (KDEL). The deduced amino acid sequence of SsCRT shares 89–92% overall sequence identities with the CRT proteins of several fish species. 〈em〉SsCRT〈/em〉 was distributed ubiquitously in all the detected tissues and was highly expressed in the spleen, muscle and liver. After the infection of fish extracellular bacterial pathogen 〈em〉Vibrio anguillarum〈/em〉 and intracellular bacterial pathogen 〈em〉Edwardsiella tarda〈/em〉, the mRNA transcripts of 〈em〉SsCRT〈/em〉 in spleen, liver, and head kidney were significantly up-regulated. The expression patterns were time-dependent and tissue-dependent. Recombinant SsCRT (rSsCRT) exhibited apparent binding activities against different bacteria and PAMPs. 〈em〉In vivo〈/em〉 studies showed that the expressions of multiple immune-related genes such as TNF13B, IL-1β, IL-8, SAA, Hsp70, and ISG15 in head kidney were significantly enhanced when black rockfish were treated with rSsCRT. Furthermore, rSsCRT reduced pathogen dissemination and replication in fish kidney and spleen. These results indicated that SsCRT served as an immune receptor to recognize and eliminate the invading pathogens, which played a vital role in the immune response of 〈em〉Sebastes schlegeli〈/em〉. These findings provide new insights into understanding the roles of CRT proteins in immune response and pathogen infection in teleost.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Ying Wu, Yongcan Zhou, Zhenjie Cao, Yun Sun, Yang Chen, Yajing Xiang, Lu Wang, Shengnan Zhang, Weiliang Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interleukins (ILs) are a subgroup of cytokines, which are molecules involved in the intercellular regulation of the immune system. These cytokines have been extensively studied in mammalian models, but systematic analyses of fish are limited. In the current study, 3 IL genes from golden pompano (〈em〉Trachinotus ovatus〈/em〉) were characterized. The IL-1β protein contains IL-1 family signature motif, and four long helices (αA - αD) in IL-11 and IL-34, which were well conserved. All 3 ILs clustered phylogenetically with their respective IL relatives in mammalian and other teleost species. Under normal physiological conditions, the expression of IL-1β, IL-11, and IL-34 were detected at varied levels in the 11 tissues examined. Most of the 3 ILs examined were highly expressed in liver, spleen, kidney, gill, or skin. Following pathogenic bacterial, viral, or parasitic challenge, IL-1β, IL-11, and IL-34 exhibited distinctly different expression profiles in a time-, tissue-, and pathogen-dependent manner. In general, IL-1β was expressed at higher levels following challenge with all pathogens examined than was observed for IL-11 and IL-34. Furthermore, 〈em〉Streptococcus agalactiae〈/em〉 and 〈em〉Cryptocaryon irritans〈/em〉 caused higher levels of IL-1β and IL-11 expression than 〈em〉Vibrio harveyi〈/em〉 and viral nervous necrosis virus (VNNV). The increased expression of IL-34 caused by VNNV and 〈em〉C. irritans〈/em〉 were higher than that caused by 〈em〉V. harveyi〈/em〉 and 〈em〉S. agalactiae〈/em〉. These results suggest that these 3 ILs in 〈em〉T. ovatus〈/em〉 may play different effect pathogen type specific responses.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Dinglong Yang, Yijing Han, Lizhu Chen, Ruiwen Cao, Qing Wang, Zhijun Dong, Hui Liu, Xiaoli Zhang, Qianqian Zhang, Jianmin Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bactericidal permeability-increasing protein (BPI) is an antimicrobial protein with potent endotoxin-neutralising activity and plays a crucial role in innate immunity against bacterial infection. In the present study, a 〈em〉bpi〈/em〉 (designed as 〈em〉rpbpi〈/em〉) was identified and characterized from manila clam 〈em〉Ruditapes philippinarum〈/em〉. Multiple alignments and phylogenetic analysis suggested that 〈em〉rpbpi〈/em〉 was a new member of the 〈em〉bpis〈/em〉 family. In non-stimulated clams, 〈em〉rpbpi〈/em〉 transcripts were ubiquitously expressed in all tested tissues with the highest expression level in hemocytes. After 〈em〉Vibrio anguillarum〈/em〉 challenge, the expression levels of 〈em〉rpbpi〈/em〉 mRNA in hemocytes were up-regulated significantly at 3 h and 48 h compared with that in the control, which were 4.01- and 19.10-fold (〈em〉P〈/em〉 〈 0.05), respectively. The recombinant RpBPI (rRpBPI) showed high antibacterial activities against Gram-negative bacteria 〈em〉Escherichia coli〈/em〉 and 〈em〉V. anguillarum〈/em〉, but not 〈em〉Staphylococcus aureus〈/em〉. Moreover, membrane integrity analysis revealed that rRpBPI increased the membrane permeability of Gram-negative bacteria, and then resulted in cell death. Overall, our results suggested that RpBPI played an important role in the elimination of invaded bacteria through membrane-disruptive activity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Wenlin Wu, Congjie Dai, Xunwei Duan, Cuifang Wang, Xiaosi Lin, Jiaying Ke, Yixuan Wang, Xiaobo Zhang, Haipeng Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉White shrimp 〈em〉Litopenaeus vannamei〈/em〉 are widely cultured in the world and white spot syndrome virus (WSSV) led to huge economic losses in the shrimp industry every year. In the present study, miRNAs involved in the response of shrimp 〈em〉L. vannamei〈/em〉 to WSSV infection were obtained through the Illumina HiSeq 2500 high-throughput next-generation sequencing technique. A total number of 7 known miRNAs and 54 putative novel miRNAs were obtained. Among them, 14 DEMs were identified in the shrimp infected with WSSV. The putative target genes of these DEMs were related to host immune response or signaling pathways, indicating the importance of miRNAs in shrimp against WSSV infection. The results will provide information for further research on shrimp response to virus infection and contribute to the development of new strategies for effective protection against WSSV infections.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Rahul Krishnan, Syed Shariq Nazir Qadiri, Myung-Joo Oh〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nectin-4/PVRL4 belonging to the family of immunoglobulin-like cell adhesion molecules was identified as a potential cellular receptor for several animal viruses. Here we show that nervous necrosis virus that causes viral nervous necrosis in teleosts uses the same receptor in its life cycle. Transfection of SSN-1 cell lines with an expression vector encoding Nectin-4 rendered them to be more susceptible to NNV. Immunofluorescence microscopy on Nectin-4 expressing cells revealed that the protein interacted with NNV specifically. A virus binding assay indicated that Nectin-4 was a bonafide receptor that supported virus attachment to the host cell whereas siRNA directed against Nectin-4 blocked NNV infections in grouper primary brain cells. Results of the present study will improve our understanding of the pathogenesis of NNV infection and provide a target for the development of novel antiviral interventions in marine finfish aquaculture.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jun Di, Zhipeng Chu, Shuhuan Zhang, Jun Huang, Hao Du, Qiwei Wei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present study, we aimed to screen the potential probiotic 〈em〉Bacillus subtilis〈/em〉 isolated from the gut of healthy fish using 〈em〉in vitro〈/em〉 assays and to evaluate its effect on Dabry's sturgeon (〈em〉Acipenser dabryanus〈/em〉) using 〈em〉in vivo〈/em〉 feeding experiments. Among the isolates, 〈em〉B. subtilis〈/em〉 BSth-5 and BSth-19 exhibited antimicrobial effect against four sturgeon-pathogenic bacteria, including 〈em〉Aeromonas hydrophila〈/em〉, 〈em〉A. veronii〈/em〉, 〈em〉A. media〈/em〉, and 〈em〉Streptococcus iniae〈/em〉. The cell number of 〈em〉B. subtilis〈/em〉 BSth-5 and BSth-19 changed little after 2 h of exposure to pH 3.0 or fresh Dabry's sturgeon bile at 2.5% and 5.0%. Meanwhile, 〈em〉B. subtilis〈/em〉 BSth-5 and BSth-19 produced extracellular protease, cellulose, and lipase. And it was proved that 〈em〉B. subtilis〈/em〉 BSth-5 and BSth-19 were harmless after injection of Dabry's sturgeon. One group of Dabry's sturgeon was fed a control diet and two groups were fed experimental diets containing 2.0 × 10〈sup〉8〈/sup〉 CFU/g BSth-5 (T1 group) or BSth-19 (T2 group) for 8 weeks. No significant differences in final weight, weight gain rate, and special growth rate were observed in the T1 and T2 groups compared to the control group (〈em〉P〈/em〉 〉 0.05), but a significant improvement in survival rate was detected after 4 and 8 weeks of feeding (〈em〉P〈/em〉 〈 0.05). After 8 weeks, serum total antioxidant capacity, total superoxide dismutase activity, and IgM levels were significantly higher in the T1 and T2 groups compared to the control group (〈em〉P〈/em〉 〈 0.05). Moreover, serum lysozyme activity was significantly higher in the T1 group relative to the control group during the whole experiment period (〈em〉P〈/em〉 〈 0.05); however, the differences were not significant between the T2 and control groups (〈em〉P〈/em〉 〉 0.05). Serum malondialdehyde levels in the T1 and T2 groups were significantly lower than those in the control group after 4 weeks (〈em〉P〈/em〉 〈 0.05). Sturgeons in the T1 and T2 groups showed a higher survival rate after 〈em〉Aeromonas hydrophila〈/em〉 infection. To summarize, dietary supplementation with BSth-5 and BSth-19 could enhance the survival rate, antioxidant activity, serum immunity, and disease resistance in 〈em〉A. dabryanus〈/em〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1050464819308204-fx1.jpg" width="388" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Håvard Bjørgen, Oskar Mongstad Løken, Ida Bergva Aas, Per Gunnar Fjelldal, Tom Hansen, Lars Austbø, Erling Olaf Koppang〈/p〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Pan Wu, Weiguang Yang, Yuying Dong, Yanling Wang, Ying Zhang, Xuejun Zou, Hui Ge, Dongxue Hu, Yubo Cui, Zhaobo Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Application of traditional bait in aquaculture caused environment pollution and disease frequent occurrence. Residual coconut could be re-utilized to culture Spinibarbus sinensis as dietary supplement. Therefore, a novel integrated system of the improvement of yield, antioxidant and nonspecific immunity of Spinibarbus sinensis by dietary residual coconut was proposed and investigated. Spinibarbus sinensis could grow well in all supplement residual coconut groups. Survival rate, yield, whole fish body composition under 15–45% groups were increased compared with control group (CK). Bioactive substances (polyphenols and vitamin) in residual coconut enhanced AKP, ACP, phagocytic, SOD, CAT activities through up-regulating 〈em〉AKP, ACP, SOD, CAT〈/em〉 genes expression levels. Theoretical analysis showed bioactive substances regulated these genes expressions and enzyme activities as stimulus signal, component, active center. Moreover, residual coconut improved mTOR and NF-kB signaling pathway. Furthermore, residual coconut inhibited 〈em〉Aeromonas hydrophila〈/em〉 that increased resistance to diseases. This technology completed the solid waste recovery and the Spinibarbus sinensis culture simultaneously.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jianting Lu, Xianyong Bu, Shusheng Xiao, Zhideng Lin, Xinyue Wang, Yongyi Jia, Xiaodan Wang, Jian G. Qin, Liqiao Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study evaluates the effect of dietary supplementation of immunostimulants on the Chinese mitten crab (〈em〉Eriocheir sinensis〈/em〉) with a single administration of mannan oligosaccharide (MOS), or its combination with either β-glucan or with inulin for 8 weeks. Four diets included an untreated control diet (C), MOS alone (3 g kg〈sup〉−1〈/sup〉, M), MOS with β-glucan (3 g kg 〈sup〉−1〈/sup〉 MOS + 1.5 g kg 〈sup〉−1〈/sup〉 β-glucan, MB), and MOS with inulin (3 g kg 〈sup〉−1〈/sup〉 MOS + 10 g kg 〈sup〉−1〈/sup〉 inulin, MI). The weight gain and specific growth rate of the crabs fed M, MB, and MI diets were improved by lowing feed conversion ratio. The growth and feed utilization of the crabs fed the MB diet were improved compared with the other three groups. The crabs fed the M, MB and MI diets showed a higher intestinal trypsin activity than that in the M and control groups. The highest trypsin activity in the hepatopancreas was observed in the MB group. Crabs fed M, MB and MI diets increased antioxidant system-related enzyme activities, but reduced malondialdehyde. The highest activities of alkaline phosphatase, acid phosphatase, lysozyme and phenol oxidase in the gut and the respiratory burst of the crabs were found in the MB group. The MB diet promoted the mRNA expression of 〈em〉E. sinensis〈/em〉 immune genes (ES-PT, ES-Relish, ES-LITAF, p38MAPK and Crustin) compared with the control. After 3 days of infection with 〈em〉Aeromonas hydrophila〈/em〉, the highest survival of crabs was also found in the MB group. This study indicates that the combination of MOS with β-glucan or with inulin can improve growth, antioxidant capacity, non-specific immunity and disease resistance in 〈em〉E. sinensis〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Marco Rozas-Serri, Andrea Peña, Lucerina Maldonado〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Piscirickettsiosis is the most challenging disease present in the Chilean salmon industry. The aim of this study was to describe the expression of genes associated with immune response of Atlantic salmon intraperitoneally infected with LF-89 and EM-90 〈em〉Piscirickettsia salmonis〈/em〉 and vaccinated with inactivated whole-cell bacterin of 〈em〉P. salmonis〈/em〉. The fish infected with PS-LF-89 showed an anti-inflammatory response, whereas this finding was not observed in the PS-EM-90-infected fish and vaccinated fish. Fish infected with both 〈em〉P. salmonis〈/em〉 isolates showed 〈em〉mhc1-mhc2〈/em〉, 〈em〉cd4-cd8b〈/em〉 and 〈em〉igm〈/em〉 overexpression, suggesting that 〈em〉P. salmonis〈/em〉 promotes a T CD4〈sup〉+〈/sup〉 and T CD8〈sup〉+〈/sup〉 cell response and a humoral immune response. The vaccinated-fish exhibited 〈em〉mhc1〈/em〉, 〈em〉mhc2〈/em〉 and 〈em〉cd4〈/em〉 overexpression but a significant downregulation of 〈em〉cd8b〈/em〉 and 〈em〉igm〈/em〉, suggesting that the vaccine supported the CD4〈sup〉+〈/sup〉 T-cell response but did not induce an immune response mediated by CD8〈sup〉+〈/sup〉 T cells or a humoral response. In conclusion, the expression pattern of genes related to the humoral and cell-mediated adaptive immune response showed upregulation in fish infected with 〈em〉P. salmonis〈/em〉 and down-regulation in vaccinated fish. The results of this study contribute to our understanding of the immune response against 〈em〉P. salmonis〈/em〉 and can be used in the optimization of SRS prevention and control measures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Wen-rui Li, Yong-hua Hu, Shuai Jiang, Li Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Japanese flounder (〈em〉Paralichthys olivaceus〈/em〉) is an important economic fish species farmed in China and other countries. It is susceptible to infection by 〈em〉Edwardsiella tarda〈/em〉, a severe fish pathogen with a broad host range. In this study, we employed high-throughput deep sequencing technology to identify, in a global scale, flounder kidney microRNAs (miRNAs) induced by 〈em〉E. tarda〈/em〉 at different stages of infection. Differentially expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs) exhibiting significantly altered expression levels before and after 〈em〉E. tarda〈/em〉 infection were examined. A total of 96 DEmiRNAs were identified, for which 2779 target genes were predicted. Eighty-seven miRNA–mRNA pairs, involving 29 DEmiRNAs and 86 DEmRNAs, showed negative correlations in their expression patterns. GO and KEGG enrichment analysis revealed that the putative target genes of the DEmiRNAs were associated with diverse biological processes, cellular components, and molecular functions. One of the DEmiRNAs, pol-miR-182-5p, was demonstrated to regulate sphingosine-1-phosphate receptor 1 (PoS1PR1) negatively in a manner that depended on the specific interaction between the seed sequence of pol-miR-182-5p and the 3'-UTR of PoS1PR1. Overexpression of pol-miR-182-5p in flounder cells promoted apoptosis and inhibited cellular viability. Knockdown of PoS1PR1 in flounder enhanced 〈em〉E. tarda〈/em〉 invasion and dissemination in fish tissues. These results provide new insights into miRNA-mediated anti-bacterial immunity in flounder.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Hongli Xia, Yuan Li, Zhiwen Wang, Wenjie Chen, Jun Cheng, Dapeng Yu, Yishan Lu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nile tilapia (〈em〉Oreochromis niloticus〈/em〉) is a pivotal economic fish that has been plagued by Streptococcus infections. Tumor necrosis factor receptor-associated factor 5 (TRAF5) is a crucial adaptor molecule, which can trigger downstream signaling cascades involved in immune pathway. In this study, Nile tilapia TRAF5 coding sequence (named OnTRAF5) was obtained, which contained typical functional domains, such as RING, zinc finger, coiled-coil and MATH domain. Different from other TRAF molecules, OnTRAF5 had shown relatively low identify with its homolog, and it was clustered into other teleost TRAF5 proteins. qRT-PCR was used to analysis the expression level of OnTRAF5 in gill, skin, muscle, head kidney, heart, intestine, thymus, liver, spleen and brain, In healthy Nile tilapia, the expression level of OnTRAF5 in intestine, gill and spleen were significantly higher than other tissues. While under 〈em〉Streptococcus agalactiae〈/em〉 infection, the expression level of OnTRAF5 was improved significantly in all detected organs. Additionally, over-expression WT OnTRAF5 activated NF-κB, deletion of RING or zinc finger caused the activity impaired. In conclusion, OnTRAF5 participate in anti-bacteria immune response and is crucial for the signaling transduction.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Tianjian Hu, Ran Chen, Lingzhi Zhang, Zhuang Wang, Dahai Yang, Yuanxing Zhang, Xiaohong Liu, Qin Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Edwardsiella piscicida〈/em〉 is an important pathogen that infects a wide range of hosts, from fish to human. Its infection leads to extensive losses in a diverse array of commercially important fish, like Japanese flounder, turbot, and tilapia. During the infection, type III secretion system (T3SS) and type VI secretion system (T6SS) of 〈em〉E. piscicida〈/em〉 play significant roles, but how T3SS and T6SS cooperatively contribute to its virulence is still unknown. In this study, we first examined the roles of T3SS and T6SS in different processes during 〈em〉E. piscicida〈/em〉 infection of host cells, and revealed that T3SS of 〈em〉E. piscicida〈/em〉 is responsible for promoting bacterial invasion, the following intracellular replication and inducing cell death in host cells, while T6SS restrains 〈em〉E. piscicida〈/em〉 intracellular replication and cell death in J774A.1 cells, which suggested that T3SS and T6SS antagonistically concert 〈em〉E. piscicida〈/em〉 infection. Furthermore, we found an significant decrease in transcription level of IL-1β in zebrafish kidney infected with T3SS mutant and an drastically increase in transcription level of TNF- α infected with T6SS mutant when compared with the wild-type. Interestingly, both T3SS and T6SS mutants showed significant attenuated virulence in the zebrafish infection model when compared with the wild-type. Finally, considering the cooperative role of T3SS and T6SS, we generated a mutant strain WEDΔT6SS based on the existing live attenuated vaccine (LAV) WED which showed improved vaccine safety and comparable immune protection. Therefore, WEDΔT6SS could be used as an optimized LAV in the future. Taken together, this work suggested a bilateral role of T3SS and T6SS which respectively act as spear and shield during 〈em〉E. piscicida〈/em〉 infection, together contribute to 〈em〉E. piscicida〈/em〉 virulence.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Yuanxia Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study aims to investigate the effects of 〈em〉Rhodiola rosea〈/em〉 polysaccharide (RRP) on the growth performance and nonspecific immunity of red swamp crayfish 〈em〉Procambarus clarkia〈/em〉. RRP was prepared by hot water extraction and partly characterised by high-performance liquid chromatography and sugar composition analyses. Three diets supplemented with three different levels of RRP (0.2, 0.6 and 1 g kg diet〈sup〉−1〈/sup〉) were formulated and tested for growth performance and nonspecific immunity of red swamp crayfish 〈em〉Procambarus clarkii,〈/em〉 while a diet without any RRP supplementation served as control. After 8 weeks of feeding, body weight gain, feed efficiency, survival rate, phenoloxidase activity, superoxide dismutase activity, glutathione peroxidase level, total haemocyte count and number of hyaline cells, semigranular cells and granular cells and resistance to 〈em〉Aeromonas hydrophila〈/em〉 were higher than those of the control. Moreover, based on the efficiency of RRP on the growth performance and nonspecific immunity of crayfish, the optimum dose of RRP was found to be 0.6 g kg diet〈sup〉−1〈/sup〉. Hence, intake of diets containing RRP could enhance the growth performance, immune responses and improve resistance of crayfish to infection by 〈em〉A. hydrophila.〈/em〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Xiujuan Zhou, Jing Xing, Xiaoqian Tang, Xiuzhen Sheng, Wenbin Zhan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interleukin-2 receptor subunit beta of flounder (〈em〉Paralichthys olivace〈/em〉, fIL-2Rβ) was annotated on the NCBI, its gene was cloned and characterized functionally in this study. And then the amino acids sequences and tertiary structure of fIL-2Rβ were analyzed, respectively. RT-PCR and ImageJ analyzed showed that fIL-2Rβ mRNA were expressed in the gill, spleen, kidney, intestines, liver, blood, muscle and skin, which showed high signals in spleen and blood. And then the recombinant protein of fIL-2Rβ extracellular region and its polyclonal antibodies were produced, native fIL-2Rβ molecules in flounder peripheral blood leukocytes (PBLs) were identified at 60.7 kDa by Mass spectrometry, which were in accordance with the molecular mass of full fIL-2Rβ protein calculated on the predicted protein sequence. Then the IL-2Rβ+ cell in T/B lymphocytes were characterized by Flow cytometry and indirect immunofluorescence assay, respectively. The results showed that the percentages of IL-2Rβ+ leukocytes, IL-2Rβ+/CD4+, IL-2Rβ+/IgM+ lymphocytes were 18.4 ± 2.7%, 4.5 ± 0.8%, 4.3% ± 0.5 in PBLs, and were 13.6 ± 0.9%, 4.6 ± 1.1%, 6.1% ± 0.4 in spleen, similarly, the percentages of IL-2Rβ+ leukocytes, IL-2Rβ+/CD4+, IL-2Rβ+/IgM+ lymphocytes were 9.4 ± 0.3%, 4.0 ± 0.5%, 5.7 ± 0.1% in head kidney, respectively. After KLH injection, compared with control group, the gene expression of IL-2, IL-2Rβ, CD3, TCR, CD79b and IgM in spleen of flounder were up-regulated, respectively (〈em〉p〈/em〉 〈 0.05). And the FCM results showed that the percentages of IL-2Rβ+ leukocytes in PBLs were significantly increased post Keyhole limpet hemocyanin (KLH) injection, which peaked 23.9 ± 0.9% at 9〈sup〉th〈/sup〉 day (〈em〉p〈/em〉 〈 0.05). To our knowledge, those results first reported that the characteristics of IL-2R and IL-2R + molecules were expressed on both B and T lymphocytes in fish. At the same time, this study lays a foundation for further exploring the interaction between IL-2 and IL-2R to promote cell proliferation and carrying out biological functions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Ebru Yilmaz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study investigated the effects of dietary anthocyanin on the growth performance, haematological, non-specific immune, and spleen gene expression responses of Nile tilapia, 〈em〉Oreochromis niloticus〈/em〉. Five experimental groups of fish with mean weights of 8.24 ± 0.64 g were used in the study; four of these were fed with diets incorporating anthocyanin (20 mg kg -〈sup〉1〈/sup〉, 40 mg kg〈sup〉−1〈/sup〉, 80 mg kg〈sup〉−1〈/sup〉 and 160 mg kg〈sup〉−1〈/sup〉), while the fifth was a control group without dietary anthocyanin. Growth performance and haematological parameters of tilapia were not affected by anthocyanin-supplemented diets (p 〉 0.05). Dietary anthocyanin significantly increased respiratory burst activity, phagocytic activity, phagocytic index, lysozyme activity, myeloperoxidase activity, serum total superoxide dismutase (T.SOD) activity, and serum catalase (CAT) activity (p 〈 0.05). The total immunoglobulin level was highest in the 80 mg kg〈sup〉−1〈/sup〉 group compared with the other groups (p 〈 0.05). In addition, with the anthocyanin-containing diets, the gene levels of interleukin 1, beta (〈em〉IL-1β〈/em〉), interleukin 8 (〈em〉IL-8〈/em〉), tumor necrosis factor (〈em〉TNF-α〈/em〉), heat shock protein 70 (〈em〉HSP70〈/em〉), and interferon gamma (〈em〉IFN-γ〈/em〉) were increased in the fish spleen, and the gene levels of 〈em〉CAT〈/em〉, 〈em〉GPx〈/em〉, and 〈em〉SOD〈/em〉 were also increased in fish liver (p 〈 0.05). At the end of the experiment, the fish were subjected to ammonia stress. The groups fed with 20 and 40 mg kg〈sup〉−1〈/sup〉 anthocyanin exhibited higher survival rates than the other groups. In summary, feeding Nile tilapia with anthocyanin-containing diets caused increases in the innate immune parameters, gene expression responses, and the survival rate of the fish subjected to ammonia stress.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Yan-Lin Guo, Lin Feng, Wei-Dan Jiang, Pei Wu, Yang Liu, Sheng-Yao Kuang, Ling Tang, Wu-Neng Tang, Xiao-Qiu Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Iron is an important mineral element for fish. In this study, we investigated the influences of dietary iron deficiency on intestinal immune function as well as underlying signaling of on-growing grass carp (〈em〉Ctenopharyngodon idella〈/em〉). Fish were fed with six graded level of dietary iron for sixty days, and a fourteen days’ challenge test under infection of 〈em〉Aeromonas hydrophila〈/em〉 thereafter. Results showed that compared with optimal iron level, iron deficiency increased enteritis morbidity, decreased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) concentrations and down-regulated mRNA levels of hepcidin, liver expressed antimicrobial peptide 2A (LEAP-2A), LEAP-2B, Mucin2, β-defensin-1, anti-inflammatory cytokines transforming growth factor β1 (TGF-β1), TGF-β2, interleukin 4/13A (IL-4/13A), IL-4/13B, IL-10, IL-11 and IL-15, inhibitor of κBα (IκBα), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1), whereas up-regulated mRNA levels of pro-inflammatory cytokines IL-1β, interferon γ2 (IFN-γ2), IL-8, IL-12p35, IL-12p40 and IL-17D, nuclear factor kappa B (NF-κB) p65, IκB kinases α (IKKα), IKKβ and eIF4E-binding protein (4E-BP) in intestine of on-growing grass carp, indicating that iron deficiency impaired intestinal immune function of fish under infection of 〈em〉A. hydrophila〈/em〉. Besides, iron excess also increased enteritis morbidity and impaired immune function of fish under infection of 〈em〉A. hydrophila〈/em〉. In addition, the effect of ferrous fumarate on intestinal immune function of on-growing grass carp is more efficient than ferrous sulfate. Finally, based on ability against enteritis, LZ activities in mid intestine and distal intestine, we recommended adding 83.37, 86.71 and 85.39 mg iron/kg into diet, respectively.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Luqing Pan, Xin Zhang, Liubing Yang, Shanshan Pan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hemocyanin, a multifunctional oxygen-carrying protein, has critical effects on immune defense in crustaceans. To explore the role of hemocyanin in anti-pathogen mechanism, effects of 〈em〉Vibrio harveyi〈/em〉 (〈em〉V. harvey〈/em〉) and 〈em〉Staphyloccocus aureus〈/em〉 (〈em〉S. aureus〈/em〉) on hemocyanin synthesis and innate immune responses were investigated in 〈em〉Litopenaeus vannamei〈/em〉 (〈em〉L. vannamei〈/em〉) during infection 〈em〉in vivo〈/em〉. Results showed that 10〈sup〉5〈/sup〉 and 10〈sup〉6〈/sup〉 cells mL〈sup〉−1〈/sup〉 〈em〉V. harveyi〈/em〉 and 10〈sup〉6〈/sup〉 cells mL〈sup〉−1〈/sup〉 〈em〉S. aureus〈/em〉 significantly affected plasma hemocyanin concentration, hepatopancreas hemocyanin mRNA and subunits expressions, plasma phenol oxidase (PO), hemocyanin-derived PO (Hd-PO), antibacterial, and bacteriolytic activities during the experiment under bacterial stress, while these parameters did not change remarkably in control group. The concentration of hemocyanin in plasma fluctuated, with a minimum at 12 h and a maximum at 24 h. Moreover, the expression of hemocyanin mRNA peaked at 12 h, while the level of hemocyanin p75 and p77 subunits reached maximum at 24 h. Besides, plasma PO and Hd-PO activities peaked at 24 h, and antimicrobial and bacteriolytic activities peaked at 12 h and 24 h, respectively. In addition, 10〈sup〉5〈/sup〉 cells mL〈sup〉−1〈/sup〉 〈em〉S. aureus〈/em〉 had no significant effect on the synthesis of hemocyanin and prophenoloxidase activating (pro-PO) system, but significantly increased antimicrobial activity at 12 h and bacteriolytic activity at 24 h. Therefore, these results suggest that the hemocyanin synthesis was initiated after invasion of pathogen, and the newly synthesized hemocyanin, acted as an immune molecule, can exerts PO activity to regulate the immune defense in 〈em〉L. vannamei in vivo〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Fangyi Chen, Kejian Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mud crabs, 〈em〉Scylla paramamosain〈/em〉, are one of the most economical and nutritious crab species in China and South Asia. Inconsistent with the high development of commercial mud crab aquaculture, effective immunological methods to prevent frequently-occurring diseases have not yet been developed. Thus, high mortalities often occur throughout the different developmental stages of this species resulting in large economic losses. In recent years, numerous attempts have been made to use various advanced biological technologies to understand the innate immunity of 〈em〉S. paramamosain〈/em〉 as well as to characterize specific immune components. This review summarizes these research advances regarding cellular and humoral responses of the mud crab during pathogen infection, highlighting hemocytes and gills defense, pattern recognition, immune-related signaling pathways (Toll, IMD, JAK/STAT, and prophenoloxidase (proPO) cascades), immune effectors (antimicrobial peptides), production of reactive oxygen species and the antioxidant system. Diseases affecting the development of mud crab aquaculture and potential disease control strategies are discussed.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1050464819307867-fx1.jpg" width="354" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Ai-Guo Huang, Xiao-Ping Tan, Shen-Ye Qu, Gao-Xue Wang, Bin Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉White spot syndrome virus (WSSV) is a serious epidemic pathogen of crustaceans and cause severe economic losses to aquaculture. However, no commercial drugs presently available to control WSSV infection. Genipin (GN) is a bioactive compound extracted from the fruit of 〈em〉Gardenia jasminoides〈/em〉 and exhibits potential antiviral activity. In the study, the antiviral activity of GN against WSSV was investigated in crayfish 〈em〉Procambarus clarkii〈/em〉 and in shrimp 〈em〉Litopenaeus vannamei〈/em〉. 〈em〉In vitro〈/em〉 antiviral test showed that GN could inhibit WSSV replication in crayfish and in shrimp, and the highest inhibition on WSSV was over 99% when treatment with 50 mg/kg of GN for 24 h. 〈em〉In vivo〈/em〉 antiviral test proved that GN could be used to treat and prevent WSSV infection. GN could also effectively protect crayfish from WSSV infection by reducing the mortality rate of WSSV-infected crayfish. Moreover, GN attenuated the WSSV-induced oxidative stress and inflammatory by upregulation the expression of antioxidant-related genes and downregulation the expression of inflammatory-related genes, respectively. Mechanically, GN inhibited WSSV replication at least via decreasing 〈em〉STAT〈/em〉 (〈em〉signal transducer and activator of transcription〈/em〉) gene expression to block WSSV immediate-early gene 〈em〉ie1〈/em〉 transcription. Additionally, the inhibition of 〈em〉BI-1〈/em〉 (〈em〉Bax inhibitor-1〈/em〉) gene expression also played an important role in the suppression of WSSV infection. In conclusion, GN represented a potential therapeutic and preventive agent to block WSSV infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Zhiying He, Fan Mao, Yue Lin, Jun Li, Xiangyu Zhang, Yuehuan Zhang, Zhiming Xiang, Zohaib Noor, Yang Zhang, Ziniu Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phagocytosis is one of the fundamental cellular immune defense parameter that helps in the elimination of the invading pathogens in both vertebrates and invertebrates, which require plenty of energy for functioning. In the present study, we identified the critical energy regulator AMP-activated protein kinase (AMPK) in 〈em〉Crassostrea hongkongensis〈/em〉 which is composed of three subunits, named 〈em〉Ch〈/em〉AMPK-α, 〈em〉Ch〈/em〉AMPK-β, and 〈em〉Ch〈/em〉AMPK-γ, and then analyzed the function of AMPK in regulating hemocyte phagocytosis. All the three 〈em〉Ch〈/em〉AMPK subunits mRNA were detected to be expressed at various embryological stages, and also constitutively expressed in multiple tissues with high expression in gill and mantle. The phylogenetic tree showed that the three subunits of AMPK were correspondingly clustered with its orthologue branches. Furthermore Western Blot analysis revealed that the AMPK pharmacological inhibitors Compound C could effectively down-regulate the Thr〈sup〉172〈/sup〉 phosphorylation level of AMPK-α, and the hemocyte phagocytosis was inhibited by Compound C (CC), which indicate its existence in the oyster. Our results showed that treatment of AMPK inhibitors significantly attenuated the capacity of hemocytes phagocytosis. Moreover, Compound C could also change the organization of actin cytoskeleton in the oyster hemocytes, demonstrating the crucial role of AMPK signaling in control of phagocytosis.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jian He, Tao-Lin Xie, Xiao Li, Yang Yu, Zhi-Peng Zhan, Shao-Ping Weng, Chang-Jun Guo, Jian-Guo He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mandarin fish (〈em〉Siniperca chuatsi〈/em〉) is a universally farmed fish species in China and has a large farming scale and economic value. With the high-density cultural mode in mandarin fish, viral diseases, such as infectious spleen and kidney necrosis virus (ISKNV) and 〈em〉Siniperca chuatsi〈/em〉 rhabdovirus (SCRV), have increased loss, which has seriously restricted the development of aquaculture. Y-Box binding protein 1 (YB-1) is a member of cold shock protein family that regulates multiple cellular processes. The roles of mammalian YB-1 protein in environmental stress and innate immunity have been studied well, but its roles in teleost fishes remain unknown. In the present study, the characteristic of 〈em〉S. chuatsi〈/em〉 YB-1 (〈em〉sc〈/em〉YB-1) and its roles in cold stress and virus infection were investigated. The 〈em〉sc〈/em〉YB-1 obtained an 1541 bp cDNA that contains a 903 bp open reading frame encoding a protein of 300 amino acids. Tissue distribution results showed that the 〈em〉sc〈/em〉YB-1 is a ubiquitously expressed gene found among tissues from mandarin fish. Overexpression of 〈em〉sc〈/em〉YB-1 can increase the expression levels of cold shock-responsive genes, such as 〈em〉scHsc70a〈/em〉, 〈em〉scHsc70b〈/em〉, and 〈em〉scp53〈/em〉. Furthermore, the role of 〈em〉sc〈/em〉YB-1 in innate immunity was also investigated in mandarin fish fry (MFF-1) cells. The expression level of 〈em〉sc〈/em〉YB-1 was significant change in response to poly (I:C), poly (dG:dC), PMA, ISKNV, or SCRV stimulation. The overexpression of 〈em〉sc〈/em〉YB-1 can significantly increase the expression levels of NF-κB-responsive genes, including 〈em〉scIL-8, scTNF-α〈/em〉, and 〈em〉scIFN-h.〈/em〉 The NF-κB-luciferase report assay results showed that the relative expression of luciferin was significantly increased in the cells overexpressed with 〈em〉sc〈/em〉YB-1 compared with those in cells overexpressed with control plasmid. These results indicate that 〈em〉sc〈/em〉YB-1 can induce the NF-κB signaling pathway in MFF-1 cells. Overexpressed 〈em〉sc〈/em〉YB-1 can downregulate the expression of ISKNV viral major capsid protein (〈em〉mcp〈/em〉) gene but upregulates the expression of SCRV 〈em〉mcp〈/em〉 gene. Moreover, knockdown of 〈em〉sc〈/em〉YB-1 using siRNA can upregulate the expression of ISKNV 〈em〉mcp〈/em〉 gene but downregulates the expression of SCRV 〈em〉mcp〈/em〉 gene. These results indicate that 〈em〉sc〈/em〉YB-1 suppresses ISKNV infection while enhancing SCRV infection. The above observations suggest that 〈em〉sc〈/em〉YB-1 is involved in cold stress and virus infection. Our study will provide an insight into the roles of teleost fish YB-1 protein in stress response and innate immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Hien Van Doan, Seyed Hossein Hoseinifar, Korawan Sringarm, Sanchai Jaturasitha, Bundit Yuangsoi, Mahmoud A.O. Dawood, Maria Ángeles Esteban, Einar Ringø, Caterina Faggio〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study aimed to assess the possible effects of Assam tea (〈em〉Camellia sinensis〈/em〉) extract (ATE) on growth performances, immune responses, and disease resistance of Nile tilapia, 〈em〉Oreochromis niloticus〈/em〉 against 〈em〉Streptococcus agalactiae〈/em〉. Five levels of ATE were supplemented into the based diet at 0, 1, 2, 4, and 8 g kg〈sup〉−1〈/sup〉 feed of Nile tilapia fingerlings (10.9 ± 0.04 g initial weight) in triplicate. After four and eight weeks of feeding, fish were sampled to determine the effects of the tea supplements upon their growth performance, as well as serum and mucosal immune responses. A disease challenge using 〈em〉S. agalactiae〈/em〉 was conducted at the end of the feeding trial. Fish fed ATE revealed significantly improved serum lysozyme, peroxidase, alternative complement (ACH50), phagocytosis, and respiratory burst activities compared to the basal control fed fish (〈em〉P〈/em〉 〈 0.05). The mucus lysozyme and peroxidase activities were ameliorated through ATE supplementation in the tilapia diets. Supplementation of ATE significantly (〈em〉P〈/em〉 〈 0.05) enhanced final body weight, weight gain, and specific growth rate; while a decreased feed conversion ratio was revealed at 2 g kg〈sup〉−1〈/sup〉 inclusion level, after four and eight weeks. Challenge test showed that the relative percent survival (RSP) of fish in each treatment was 33.33%, 60.00%, 83.33%, 76.68%, and 66.68% in groups fed 0, 1, 2, 4, and 8 g kg〈sup〉−1〈/sup〉, respectively. In summary, diets supplemented with ATE especially at 2 g kg〈sup〉−1〈/sup〉 increased the humoral and mucosal immunity, enhanced growth performance, and offered higher resistance against 〈em〉S. agalactiae〈/em〉 infection in Nile tilapia.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jiquan Zhang, Yujie Liu, Yongzhao Zhou, Wenzheng Wang, Naike Su, Yuying Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Trehalose, a nonreducing disaccharide, is present in a wide variety of organisms and plays a key role in many organisms under different stress conditions. In the study, the full-length cDNA sequence encoding trehalose-6-phosphate synthase (EcTPS) was obtained from 〈em〉Exopalaemon carinicauda〈/em〉. The complete nucleotide sequence of 〈em〉EcTPS〈/em〉 contained a 2532 bp open reading frame (ORF) encoding a putative protein of 843 amino acids. The domain architecture of the deduced EcTPS contained a glycol_transf_20 domain and a trehalose_PPase domain. 〈em〉EcTPS〈/em〉 mRNA was predominantly expressed in the hepatopancreas. The expression of 〈em〉EcTPS〈/em〉 in the prawns challenged with 〈em〉Vibrio parahaemolyticus〈/em〉 and 〈em〉Aeromonas hydrophila〈/em〉 changed in a time-dependent manner. The function of 〈em〉EcTPS〈/em〉 was also studied by double-strand RNA interference. The results showed that the knock-down of 〈em〉EcTPS〈/em〉 increased the mortality of the 〈em〉Vibrio〈/em〉-challenged group and 〈em〉Aeromonas〈/em〉-challenged group compared with the control group. The present study provides some new insight into the immune function of the trehalose-6-phosphate synthase in prawns.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Rui Jia, Zhengyan Gu, Qin He, Jinliang Du, Liping Cao, Galina Jeney, Pao Xu, Guojun Yin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Radix Bupleuri extract (RBE) is one of the most popular oriental herbal medicines, which has anti-oxidative and anti-inflammatory properties. However, its protective effects and underlying molecular mechanisms on oxidative damage in tilapia are still unclear. The aims of the study were to explore the anti-oxidative, anti-inflammatory and hepatoprotective effects of RBE against oxidative damage, and to elucidate underlying molecular mechanisms in fish. Tilapia received diet containing three doses of RBE (0, 1 and 3 g/kg diet) for 60 days, and then were given an intraperitoneal injection of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 or saline. Before injection, RBE treatments improved growth performance and partial anti-oxidative capacity in tilapia. After oxidative damage, RBE pretreatments were able to signally reduce the higher serum aminotransferases, alkaline phosphatase (AKP) and liver necrosis. In serum and liver, the abnormal lipid peroxidation level and antioxidant status induced by H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 injection were restored by RBE treatments. Furthermore, RBE treatments activated erythroid 2-related factor 2 (Nrf2) signaling pathway, which promoted the gene expression of heme oxygenase 1 (HO-1), NAD(P) H:quinone oxidoreductase 1 (NQO-1), glutathione-S-transferase (GST) and catalase (CAT). Meanwhile, RBE treatments reduced inflammatory response by inhibiting TLRs-MyD88-NF-κB signaling pathway, accompanied by the lower interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-8 mRNA levels. In addition, RBE treatments upregulated complement (C3) gene expression and downregulated heat shock protein (HSP70) gene expression. In conclusion, the current study suggested that RBE pretreatments protected against H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉-induced oxidative damage in tilapia. The beneficial activity of RBE may be due to the modulation of Nrf2/ARE and TLRs-Myd88-NF-κB signaling pathway.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Ye Zhao, Hui Liu, Qing Wang, Bingjun Li, Hongxia Zhang, Yongrui Pi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The gut microbiota is essential for health and physiological functions in the host organism. However, the toxicological evaluation of environmental pollutants on the gut microbiota is still insufficient. In the present study, the juvenile sea cucumber 〈em〉Apostichopus japonicus〈/em〉 was exposed for 14 days to Benzo[〈em〉a〈/em〉]pyrene (BaP), which is a model polycyclic aromatic hydrocarbon (PAH), at four different concentrations (0, 0.5, 5, and 25 μg/L). We analyzed the intestinal microbial community of 〈em〉A. japonicas〈/em〉 using 16S rRNA gene amplicon sequencing. Our results demonstrate that BaP exposure caused alterations to the microbiome community composition in sea cucumbers. At the phylum level, 〈em〉Planctomycetes〈/em〉 were significantly more abundant in BaP exposure groups at 14 d compared with the control group, and the abundance of 〈em〉Proteobacteria〈/em〉 and 〈em〉Bacteroidetes〈/em〉 increased while the abundance of 〈em〉Firmicutes〈/em〉 decreased following BaP exposure. At the genus level, multiple beneficial and autochthonous genera declined in the BaP treatment groups compared to the control, including 〈em〉Lactococcus〈/em〉, 〈em〉Bacillus〈/em〉, 〈em〉Lactobacillus〈/em〉, 〈em〉Enterococcus〈/em〉, 〈em〉Leuconostoc〈/em〉 and 〈em〉Weissella〈/em〉; however, a bloom of alkane-degrading bacteria was found in BaP-exposed guts and included 〈em〉Lutibacter〈/em〉, 〈em〉Pseudoalteromonas〈/em〉, 〈em〉Polaribacter〈/em〉, 〈em〉Rhodopirellula〈/em〉 and 〈em〉Blastopirellula〈/em〉. Furthermore, histological morphology, enzymatic activity and gene expression analysis revealed that BaP exposure also negatively impacted gut structure and function and presented as inflammation or atrophy, oxidative stress and immune suppression in sea cucumber intestines. Collectively, these findings provide insights into the toxic effects of BaP exposure on 〈em〉A. japonicas〈/em〉 associated with intestinal microbiota and health.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Mengting Luo, Linwei Yang, Zi-ang Wang, Hongliang Zuo, Shaoping Weng, Jianguo He, Xiaopeng Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉C-type lectins (CTLs) are a group of lectins with at least one carbohydrate recognition domain (CRD), the binding of which to carbohydrates requires the presence of calcium ions. CTLs generally function as pattern recognition receptors (PRRs), essentially participating in innate immunity. In the current study, a novel CTL termed LvCTL5 was identified from Pacific white shrimp 〈em〉Litopenaeus vannamei〈/em〉, which shared sequence identities with other crustacean CTLs. LvCTL5 was highly expressed in hepatopancreas and could be activated by infection with bacteria, virus and fungi. The recombinant LvCTL5 protein purified from 〈em〉E. coli〈/em〉 showed microbiostatic and agglutination activities against bacteria and fungi 〈em〉in vitro〈/em〉. Silencing of LvCTL5 〈em〉in vivo〈/em〉 could significantly affect expression of a series of immune effector genes and down-regulate the phagocytic activity of hemocytes. Compared with controls, the LvCTL5-silenced shrimp were highly susceptible to 〈em〉Vibrio parahaemolyticus〈/em〉 and white spot syndrome virus (WSSV) infections. These suggest that LvCTL5 has microbiostatic and immune regulatory activities and is implicated in antiviral and antibacterial responses.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Yi Tang, Yujia Sun, Lingmin Zhao, Xiaojin Xu, Lixing Huang, Yingxue Qin, Yongquan Su, Ganfeng Yi, Qingpi Yan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Large yellow croaker (〈em〉Larimichthys crocea〈/em〉) is an economical important farmed fish in China. “Visceral White Spot Disease” caused by 〈em〉Pseudomonas plecoglossicida〈/em〉 is a disease with a high mortality rate in cage-cultured 〈em〉L. crocea〈/em〉 in recent years and resulted in heavy economy lossess. The dual RNA-seq results of previous study showed that the expression of 〈em〉clpV〈/em〉 gene in 〈em〉P. plecoglossicida〈/em〉 was significantly up-regulated during infection. RNAi significantly reduced the expression of 〈em〉clpV〈/em〉 in 〈em〉P. plecoglossicida〈/em〉 with maximum silencing efficiency of 96.1%. Compared with the wild type strain, infection of 〈em〉clpV〈/em〉-RNAi strain resulted in a delayed onset time and a 25% reduction in mortality of 〈em〉L. crocea〈/em〉, as well as lessening the symptoms of the spleen. The results of dual RNA-seq of 〈em〉L. crocea〈/em〉 infected by 〈em〉clpV〈/em〉-RNAi strain of 〈em〉P. plecoglossicida〈/em〉 changed considerably, compared with the counterpart infected with the wild strain. The KEGG enrichment analysis showed that Cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, C-type lectin receptor signaling pathway and MAPK signaling pathway of 〈em〉L. crocea〈/em〉 were most affected by the silence of 〈em〉clpV〈/em〉 in 〈em〉P. plecoglossicida〈/em〉. RNAi of 〈em〉clpV〈/em〉 resulted in the downregulation of genes in flagella assembly pathway and a weaker immune response of host.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Hao Chen, Minxiao Wang, Huan Zhang, Hao Wang, Zhao Lv, Li Zhou, Zhaoshan Zhong, Chao Lian, Lei Cao, Chaolun Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As domain species in seep and vent ecosystem, Bathymodioline mussels has been regarded as a model organism in investigating deep sea chemosymbiosis. However, mechanisms underlying their symbiosis with chemosynthetic bacteria, especially how the host recognizes symbionts, have remained largely unsolved. In the present study, a modified pull-down assay was conducted using enriched symbiotic methane-oxidation bacteria as bait and gill proteins of 〈em〉Bathymodiolus platifrons〈/em〉 as a target to isolate pattern recognition receptors involved in the immune recognition of symbionts. As a result, a total of 47 proteins including BpLRR-1 were identified from the pull-down assay. It was found that complete cDNA sequence of BpLRR-1 contained an open reading frame of 1479 bp and could encode a protein of 492 amino acid residues with no signal peptide or transmembrane region but eight LRR motif and two EFh motif. The binding patterns of BpLRR-1 against microbial associated molecular patterns were subsequently investigated by surface plasmon resonance analysis and LPS pull-down assay. Consequently, BpLRR-1 was found with high binding affinity with LPS and suggested as a key molecule in recognizing symbionts. Besides, transcripts of BpLRR-1 were found decreased significantly during symbiont depletion assay yet increased rigorously during symbionts or nonsymbiotic 〈em〉Vibrio alginolyticus〈/em〉 challenge, further demonstrating its participation in the chemosynthetic symbiosis. Collectively, these results suggest that BpLRR-1 could serve as an intracellular recognition receptor for the endosymbionts, providing new hints for understanding the immune recognition in symbiosis of 〈em〉B. platifrons〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): Yuan Luo, Yun-Ni Zhang, Han Zhang, Hong-Bo Lv, Mei-Ling Zhang, Li-Qiao Chen, Zhen-Yu Du〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Peroxisome proliferator-activated receptor α (PPARα) plays critical physiological roles in energy metabolism, antioxidation and immunity of mammals, however, these functions have not been fully understood in fish. In the present study, Nile tilapia (〈em〉Oreochromis niloticus〈/em〉) were fed with fenofibrate, an agonist of PPARα, for six weeks, and subsequently challenged with 〈em〉Aeromonas hydrophila〈/em〉. The results showed that PPARα was efficiently activated by fenofibrate through increasing mRNA and protein expressions and protein dephosphorylation. PPARα activation increased significantly mitochondrial fatty acid β-oxidation efficiency, the copy number of mitochondrial DNA and expression of monoamine oxidase (MAO), a marker gene of mitochondria. Meanwhile, PPARα activation also increased significantly the expression of NADH dehydrogenase [ubiquinone] 1α subcomplex subunit 9 (NDUFA9, complex I) and mitochondrial cytochrome 〈em〉c〈/em〉 oxidase 1 (MTCO1, complex IV). The fenofibrate-fed fish had higher survival rate when exposed to 〈em〉A. hydrophila〈/em〉. Moreover, the fenofibrate-fed fish also had higher activities of immune and antioxidative enzymes, and gene expressions of anti-inflammatory cytokines, while had lower expressions of pro-inflammatory cytokine genes. Taken together, PPARα activation improved the ability of Nile tilapia to resist 〈em〉A. hydrophila〈/em〉, mainly through enhancing mitochondrial fatty acids β-oxidation, immune and antioxidant capacities, as well as inhibiting inflammation. This is the first study showing the regulatory effects of PPARα activation on immune functions through increasing mitochondria-mediated energy supply in fish.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): Ivon F. Maha, Xiao Xie, Suming Zhou, Youbin Yu, Xiao Liu, Aysha Zahid, Yuhua Lei, Rongrong Ma, Fei Yin, Dong Qian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The yellow drum 〈em〉Nibea albiflora〈/em〉 is less susceptible to 〈em〉Cryptocaryon irritans〈/em〉 infection than is the case with other marine fishes such as 〈em〉Larimichthys crocea〈/em〉, 〈em〉Lateolabrax japonicus,〈/em〉 and 〈em〉Pagrus major〈/em〉. To investigate further their resistance mechanism, we infected the 〈em〉N. albiflora〈/em〉 with the 〈em〉C. irritans〈/em〉 at a median lethal concentration of 2050 theronts/g fish. The skins of the infected and the uninfected fishes were sampled at 24 h and 72 h followed by an extensive analysis of metabolism. The study results revealed that there were 2694 potential metabolites. At 24 h post-infection, 12 metabolites were up-regulated and 17 were down-regulated whereas at 72 h post-infection, 22 metabolites were up-regulated and 26 were down-regulated. Pathway enrichment analysis shows that the differential enriched pathways were higher at 24 h with 22 categories and 58 subcategories (49 up, 9 down) than at 72 h whereby the differential enriched pathways were 6 categories and 8 subcategories (4 up, 4 down). In addition, the principal component analysis (PCA) plot shows that at 24 h the metabolites composition of infected group were separately clustered to uninfected group while at 72 h the metabolites composition in infected group were much closer to uninfected group. This indicated that 〈em〉C. irritans〈/em〉 caused strong metabolic stress on the 〈em〉N. albiflora〈/em〉 at 24 h and restoration of the dysregulated metabolic state took place at 72 h of infection. Also, at 72 h post infection a total of 17 compounds were identified as potential biomarkers.〈/p〉 〈p〉Furthermore, out of 2694 primary metabolites detected, 23 metabolites could be clearly identified and semi quantified with a known identification number and assigned into 66 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Most of the enriched KEGG pathways were mainly from metabolic pathway classes, including the metabolic pathway, biosynthesis of secondary metabolites, taurine and hypotaurine metabolism, purine metabolism, linoleic acid metabolism, phenylalanine, tyrosine and tryptophan biosynthesis. Others were glyoxylate and dicarboxylate metabolism, glutathione metabolism, and alanine, aspartate, and glutamate metabolism. Moreover, out of the identified metabolites, only 6 metabolites were statistically differentially expressed, namely, L -glutamate (up-regulated) at 24 h was important for energy and precursor for other glutathiones and instruments of preventing oxidative injury; 15-hydroxy- eicosatetraenoic acid (15-HETE), (S)-(−)-2-Hydroxyisocaproic acid, and adenine (up-regulated) at 72 h were important for anti-inflammatory and immune responses during infection; others were delta-valerolactam and betaine which were down-regulated compared to uninfected group at 72 h, might be related to immure responses including stimulation of immune system such as production of antibodies.〈/p〉 〈p〉Our results therefore further advance our understanding on the immunological regulation of 〈em〉N. albiflora〈/em〉 during immune response against infections as they indicated a strong relationship between skin metabolome and 〈em〉C. irritans〈/em〉 infection.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Hye-Jin Go, Chan-Hee Kim, Ji Been Park, Tae Young Kim, Tae Kwan Lee, Hye Young Oh, Nam Gyu Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fish skin mucus is considered to act as the first line of defense against waterborne pathogens and to be potential source of novel antimicrobial components. Here we report the purification and characterization of a novel hepcidin type 2-like antimicrobial peptide (〈em〉Tp〈/em〉HAMP2) from the skin mucus of the pufferfish 〈em〉Takifugu pardalis〈/em〉. The purified 〈em〉Tp〈/em〉HAMP2 comprised of 23 amino acids (AAs) with eight Cys residues that form four intramolecular disulfide bonds. The 〈em〉Tp〈/em〉HAMP2 gene shared overall structural characteristics with all known hepcidins, which have a tripartite exon-intron gene organization and three structural signatures in the precursor protein. Phylogenetically, 〈em〉Tp〈/em〉HAMP2 was classified as HAMP2 class in acanthopterygian fish. Interestingly, the AA sequence of 〈em〉Tp〈/em〉HAMP2 did not contain a proprotein cleavage site (RXXR motif) that conserved in most hepcidins and showed a highly positive charged (RKR-) short N-terminus and Val〈sup〉18〈/sup〉 and Gly〈sup〉22〈/sup〉 residues, which are distinctive structures compared to other known active hepcidins. Recombinant 〈em〉Tp〈/em〉HAMP2 identical to the native form exhibited a broad spectrum and potent antimicrobial activity against tested gram-positive and -negative bacteria. Expression of 〈em〉Tp〈/em〉HAMP2 mRNA was predominant in the liver and was upregulated in the liver, the spleen, the intestine, and the skin of 〈em〉T. pardalis〈/em〉 post immune challenge. Thus, our findings suggests that 〈em〉Tp〈/em〉HAMP2 might be of importance in the framework of discovering the fish hepcidins, especially type 2s, and provide noteworthy insight into its gene structure and expression and in the innate immunity as well as the mucosal immunity in regard to hepcidins’ evolutionary history in fish species.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Chen Li, Yepin Yu, Xin Zhang, Jingguang Wei, Qiwei Qin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Autophagy is an evolutionarily conserved, multi-step lysosomal degradation process used to maintain cell survival and homeostasis. A series of autophagy-related genes (Atgs) are involved in the autophagic pathway. In mammals, a growing number of studies have attributed functions to some Atgs that are distinct from their classical role in autophagosome biogenesis, such as resistance to pathogens. However, little is known about the functions of fish Atgs. In this study, we cloned and characterized an 〈em〉atg12〈/em〉 homolog from orange spotted grouper (〈em〉Epinephelus coioides〈/em〉) (〈em〉Ecatg12〈/em〉). 〈em〉Ecatg12〈/em〉 encodes a 117 amino acid protein that shares 94.0% and 76.8% identity with gourami (〈em〉Anabas_testudineus〈/em〉) and humans (〈em〉Homo sapiens〈/em〉), respectively. The transcription level of 〈em〉Ecatg12〈/em〉 was lower in cells infected with Singapore grouper iridovirus (SGIV) than in non-infected cells. Fluorescence microscopy revealed that EcAtg12 localized in the cytoplasm and nucleus in grouper spleen cells. Overexpression of EcAtg12 significantly increased the replication of SGIV, as evidenced by increased severity of the cytopathic effect, transcription levels of viral genes, levels of viral proteins, and progeny virus yield. Further studies showed that EcAtg12 overexpression decreased the expression levels of interferon (IFN) related molecules and pro-inflammatory factors and inhibited the promoter activity of IFN-3, interferon-stimulated response element, and nuclear factor-κB. Together, these results demonstrate that EcAtg12 plays crucial roles in SGIV replication by downregulating antiviral immune responses.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Lijun Xu, Luqing Pan, Xin Zhang, Cun Wei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Shrimps like other arthropods rely on innate immune system, and may have some form of adaptive immunity in defending against pathogens. Phagocytosis is one of the oldest cellular processes, serving as a development process, a feeding mechanism and especially as a key defense reaction in innate immunity of all multicellular organisms. It is confirmed that crustacean hyperglycemic hormone (CHH) is one of the most important neuropeptides produced by Neuro-endocrine Immune (NEI) regulatory network, which undertakes important roles in various biological processes, especially in immune function and stress response. In this study, the recombinant 〈em〉Litopenaeus vannamei〈/em〉 CHH (rLvCHH) was obtained from a bacterial expression system and the intracellular signaling pathways involved in the mechanism of phagocytosis after rLvCHH injection was investigated. The results showed that the contents of adenylyl cyclase (AC), phospholipase C (PLC) and calmodulin (CaM) in hemocytes were increased significantly after rLvCHH injection. Furthermore, the mRNA expression levels of NF-kB family members (relish and dorsal) and phagocytosis-related proteins in hemocytes were basically overexpressed after rLvCHH stimulation, while the expression level of NF-kB repressing factor (NKRF) gene was down-regulated significantly. Eventually, the total hemocyte count and phagocytic activity of hemocyte were dramatically enhanced within 3 h. Collectively, these results indicate that shrimps 〈em〉L. vannamei〈/em〉 could carry out a simple but ‘smart’ NEI regulation through the action of neuroendocrine factors, which could couple with their receptors and trigger the downstream signaling pathways during the phagocytic responses of hemocytes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Maxime Boutier, Yuan Gao, Owen Donohoe, Alain Vanderplasschen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Aquaculture is one of the world's most important and fastest growing food production sectors, with an average annual growth of 5.8% during the period 2001–2016. Common carp (〈em〉Cyprinus carpio〈/em〉) is one of the main aquatic species produced for human consumption and is the world's third most produced finfish. Koi carp, on the other hand, are grown as a popular ornamental fish. In the late 1990s, both of these sectors were threatened by the emergence of a deadly disease caused by cyprinid herpesvirus 3 (CyHV-3; initially called koi herpesvirus or KHV). Since then, several research groups have focused their work on developing methods to fight this disease. Despite increasing knowledge about the pathobiology of this virus, there are currently no efficient and cost-effective therapeutic methods available to fight this disease. Facing the lack of efficient treatments, safe and efficacious prophylactic methods such as the use of vaccines represent the most promising approach to the control of this virus. The common carp production sector is not a heavily industrialized production sector and the fish produced have low individual value. Therefore, development of vaccine methods adapted to mass vaccination are more suitable. Multiple vaccine candidates against CyHV-3 have been developed and studied, including DNA, bacterial vector, inactivated, conventional attenuated and recombinant attenuated vaccines. However, there is currently only one vaccine commercially available in limited regions. The present review aims to summarize and evaluate the knowledge acquired from the study of these vaccines against CyHV-3 and provide discussion on future prospects.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Yilong Wang, Baojie Wang, Xuqing Shao, Jianchun Shao, Mei Liu, Mengqiang Wang, Lei Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Rearing density and disease management are considered as pivotal factors determining shrimp farm productivity and profitability. To systematically investigate the potential mechanisms for density-related differences between disease susceptibility and rearing densities, we conducted comparative transcriptome analysis of the molecular differences between hepatopancreas and intestine of 〈em〉Litopenaeus vannamei〈/em〉 under two different rearing densities (800- and 400- shrimp/m〈sup〉3〈/sup〉) for 15 d and further analyzed the differences in immune response to 〈em〉Vibrio parahaemolyticus〈/em〉 E1 (VPE1) raised under two density conditions. Totally 45 different expression genes (DEGs) were identified in the hepatopancreas under two different rearing densities, the DEGs were grouped into four processes or pathways related to animal immune system. Then, exposure to the VPE1 resulted in 639 DEGs, involved into fourteen immune related processes or pathways. In the intestine, seventeen processes or pathways related to the immune system were identified among the 5470 DEGs under two different rearing densities. 279 DEGs were identified post VPE1 challenge, classified into five processes or pathways associated with the immune system. Meanwhile, the results of growth performance, histopathology and the activities of antioxidant enzymes in the hepatopancreas and intestines of shrimp showed that high density decreased weight gain rate (63.20 ± 1.67% and 18.73 ± 3.35% in the high and low rearing density groups, respectively), severely destroyed the histopathology and inhibited the antioxidant enzymes activities. This study demonstrated that rearing density in 〈em〉L. vannamei〈/em〉 significantly impacts susceptibility to the VPE1, via altered transcriptional challenge responses, and thus higher mortality due to disease.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Youliang Rao, Jianfei Ji, Zhiwei Liao, Hang Su, Jianguo Su〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉TANK-binding kinase 1 (TBK1) is an important kinase that regulates the activation of interferon regulatory factor 3/7 (IRF3/7) to induce type I interferon (IFN–I) production in antiviral immune responses. However, in long-term virus-host crosstalk, viruses have evolved elaborate strategies to evade host immune defense mechanisms. In the present study, we found that grass carp (〈em〉Ctenopharyngodon idella〈/em〉) reovirus (GCRV) hijacks TBK1 to escape IRF7-IFN-Is signaling activation. In brief, GCRV inhibited TBK1 activation by restaining K63-linked ubiquitination of TBK1 and promoting its K48-linked ubiquitination. This regulation resulted in that under low titer of GCRV infection, TBK1 overexpression specifically supressed promoter activity and phosphorylation of IRF7 and induction of downstream IFN1and IFN3. qRT-PCR data uncovered that TBK1 negatively regulated IRF7, IFN1 and IFN3 transcription levels under low viral titer infection. Along with enhancement of GCRV titers, TBK1 swiched its function to up-regulate IRF7, IFN1 and IFN3 mRNA levels. Accordingly, TBK1 promoted GCRV replication at low infected titer, but inhibited GCRV replication at high infected titer. All these results revealed a viral evasion strategy that GCRV utilizes TBK1 to block cellular IFN responses at low titers or early stages in fish species, which will lay a foundation for further researching on host-virus interactions and developing novel antiviral strategies in lower vertebrates.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Dongyan Guan, Huiwen Sun, Xiao Meng, Jiting Wang, Wenju Wan, Haojun Han, Zhen Wang, Yang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A feeding trial was conducted to evaluate the effects of different molar mass chitooligosaccharides (1000 Da, 3000 Da and 8000 Da) on growth, antioxidant capacity, non-specific immune response, and resistance to 〈em〉Aeromonas hydrophila〈/em〉 in GIFT tilapia (〈em〉Oreochromis niloticus〈/em〉). A total of 600 fish were divided into four treatments with five replicates of thirty fish per tank. The results showed that the supplementation of 1000 Da and 3000 Da COS significantly improved the growth performance and feed utilization in GIFT tilapia. The trend of decreasing total cholesterol, triglyceride, ALT, and ACP activity was observed in fish fed diet supplemented COS. The supplementation of 1000 Da and 3000 Da COS significantly improved the serum TAC activity, and decreased the serum MDA and catalase activities (〈em〉P〈/em〉 〈 0.05). The lysozyme activity of blood, liver, and gills in fish fed diets supplemented with 1000 Da and 3000 Da COS was significantly higher than that of fish fed control diet after 56 days of feeding (〈em〉P〈/em〉 〈 0.05). The phagocytic activity and phagocytic index of fish fed diets supplemented with 1000 Da and 3000 Da COS were significantly higher than those of fish fed control diet. Post-challenge test showed that fish mortality in 1000 Da, 3000 Da, and 8000 Da COS groups were significantly lower than that of fish in control group (〈em〉P〈/em〉 〈 0.05). In conclusion, the present study indicated that dietary 1000 Da and 3000 Da COS supplementation could enhance more performance and immune response of GIFT tilapia than 8000 Da COS.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Ke Ji, Hualiang Liang, Mingchun Ren, Xianping Ge, Bo Liu, Bingwen Xi, Liangkun Pan, Heng Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dietary administration of tryptophan has been proved improving growth performance of fish. An 8-week feeding trial was conducted to investigate the effects of dietary tryptophan level on antioxidant capacity and immune response through Nrf2 and TOR signaling pathway. The results showed that, 0.08% tryptophan level significantly increased plasma aspartate aminotransferase (AST), while immunoglobulin M (IgM) and alkaline phosphatase (ALP) were strikingly increased by 0.40% level. The level of plasma complement component 3 (C3), alanine aminotransferase (ALT) and albumin (ALB) were independent of tryptophan supplementation. Total superoxide dismutase (T-SOD), catalase (CAT), total antioxidant capacity (T-AOC) and glutathione (GSH) activity were increased with increasing dietary tryptophan level until 0.40% and then decreased, while the level of malondialdehyde (MDA) showed a reverse trend. 0.19% and 0.28% tryptophan level significantly improved the glutathione peroxidase 1 (GPx-1) activity. Compared with 0.08% dietary tryptophan level, 0.40% level significantly improved nuclear factor erythroid 2-related factor 2 (Nrf2), GPx, manganese superoxide dismutase (Mn-SOD), CAT and transforming growth factor-β (TGF-β) mRNA level, while Kelch-like ECH-associated protein 1 (Keap1) and interleukin 1β (IL-1β) mRNA level were significantly decreased. The relative expression of copper zinc superoxide dismutase (Cu/Zn-SOD), heme oxygenase-1 (HO-1), target of rapamycin (TOR), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), protein kinase B (Akt) and interleukin 10 (IL-10) were significantly improved by 0.28% diet, while the mRNA level of tumor necrosis factor-α (TNF-α) and nuclear factor-kappa B (NF-κB) were increased by 0.08% diet. Interleukin 8 (IL-8) mRNA level was not significantly affected by dietary tryptophan. Based on MDA and T-SOD value, the optimal dietary tryptophan level of juvenile blunt snout bream was determined to be 0.33% (1.03% of dietary protein) and 0.36% (1.13% of dietary protein), respectively, using quadratic regression analysis.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Changle Qi, Xiaodan Wang, Fenglu Han, Yongyi Jia, Zhideng Lin, Chunling Wang, Jianting Lu, Lu Yang, Xinyue Wang, Erchao Li, Jian G. Qin, Liqiao Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To investigate the effects of arginine (Arg) on the growth, antioxidant capacity, immunity and disease resistance of juvenile Chinese mitten crab, three diets containing Arg levels at 1.72% (control), 2.73% and 3.72% were formulated and fed to Chinese mitten crab (0.22 ± 0.03 g) for eight weeks. The weight gain, ecdysterone and growth hormone in the serum, relative expression of insulin-like growth factor 2 in the hepatopancreas significantly increased in crabs fed the 2.73% and 3.72% Arg diets. The protein and lipid contents significantly increased in crabs fed the 3.72% Arg diet. The feed conversion ratios in crabs fed the diets with Arg additions were lower than in the control. Arg supplementation also enhanced the antioxidative capacity by increasing the activities of superoxide dismutase, catalase and the relative expression of Kelch-like ECH-associated protein 1 gene in the hepatopancreas, which subsequently decreased malondialdehyde content in the hepatopancreas. Besides, Arg also decreased nitric oxide content in the serum and the activity of nitric oxide synthetase in the hepatopancreas. The relative mRNA levels of crustin, relish, lysozyme and cryptocyanin genes were significantly upregulated by Arg supplementation. The activities of acid phosphatase and alkaline phosphatase in the serum significantly increased in crabs fed the 3.72% Arg diet than those in the control. Similarly, the relative mRNA levels of crustin, cryptocyanin and proPO genes were significantly upregulated in crabs fed the 2.73% Arg diet after lipopolysaccharide challenge, and in crabs fed the 3.72% Arg diet after the Poly (I:C) challenge. The crabs fed the 2.73% and 3.72% Arg diets had higher survival rate after bacterial infection than those fed the control diet. This study indicates that the addition of Arg to the diet at 2.7–3.7% can improve the growth, survival, antioxidant capacity, immunity and disease resistance in juvenile Chinese mitten crab.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Kamila Oliveira Santos, João Costa-Filho, Jade Riet, Kérolin Luana Spagnol, Bruna Félix Nornberg, Mateus Tavares Kütter, Marcelo Borges Tesser, Luis Fernando Marins〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Although aquaculture is among the fastest growing food production sectors in the world, one of the bottlenecks for the continuity of its expansion is the dependence of animal protein on commercial feed formulations. Vegetable proteins are an alternative due to the low cost and high availability. However, this protein source is accompanied by a series of antinutritional and pro-inflammatory compounds, including phytate. Phytases can be added in feed for phytate degradation and increase nutrient availability. However, the use of purified phytases significantly increases the production costs. An interesting alternative is to use probiotics genetically modified as bioreactors for phytase production. In the present study, a strain of 〈em〉Bacillus subtilis〈/em〉 secreting a fungal phytase was used to evaluate the effect of a feed with high content of soybean meal on zebrafish (〈em〉Danio rerio〈/em〉). We analysed the condition factor (K) of fish, and the expression of genes related to the immune system, inflammatory response and oxidative.〈/p〉 〈p〉stress. The results obtained demonstrate that the transgenic probiotic was efficient in improving the fish condition factor, stimulating the immune system, reducing the inflammatory response and oxidative stress. Thus, probiotics acting as phytase bioreactors can be considered an interesting tool for the adaptation of commercial species to feed of lower cost.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Kun Yang, Shiyu Feng, Shengnan Zhang, Licheng Yin, Hong Zhou, Anying Zhang, Xinyan Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a new 〈em〉il-4/13〈/em〉 cDNA was isolated from grass carp 〈em〉(Ctenopharyngodon idella)〈/em〉 using homologous cloning. The phylogenetic tree and sequence alignment of the deduced amino acid (aa) sequence showed that it was closer to grass carp 〈em〉il-4/13b〈/em〉 (〈em〉gcil-4/13b〈/em〉) than other homologues and therefore named 〈em〉gcil-4/13b-like〈/em〉 (〈em〉gcil-4/〈/em〉13bl). It has 399-nt coding sequence (CDS) which is less than 〈em〉gcil-4/13b〈/em〉 (408 nt). In addition, the cloned 〈em〉gcil-4/〈/em〉13bl gene is approximately 1600 bp in length and has a conserved genetic structure consisting of four exons and three introns. Compared to 〈em〉gcil-4/13b〈/em〉 gene, it has a variety of nucleotides variation across the CDS and contains a longer intron 3, suggesting that it is a new 〈em〉gcil-4/13〈/em〉 gene. The 〈em〉gcil-4/〈/em〉13bl transcripts were ubiquitously expressed in almost all selected tissues, and there was almost only 〈em〉gcil-4/〈/em〉13bl detected in brain and head kidney (HK). Recombinant grass carp (rgc) Il-4/13bl was prepared by using 〈em〉Escherichia coli〈/em〉 (〈em〉E. coli〈/em〉) Rosetta-gami 2 (DE3). The functional study demonstrated that rgcIl-4/13bl significantly upregulated 〈em〉arginase-2〈/em〉 gene expression and arginase activity, whilst downregulated nitric oxide (NO) production as well as the transcript levels of inducible nitric oxide synthesase (〈em〉inos〈/em〉) and 〈em〉ifn-γ〈/em〉 in freshly isolated grass carp HK monocytes/macrophages (M0/Mϕ). These data suggested that the newly cloned 〈em〉il-4/〈/em〉13bl had the conserved functions to activate M2-type but antagonize M1-type macrophages. Furthermore, rgcIl-4/13bl was able to drive the proliferation of M0/Mϕ which were pre-treated by rgcM-csf, indicating the involvement of gcIl-4/13bl in the proliferation of macrophages. Here we not only identified a new 〈em〉il-4/13〈/em〉-encoding gene in grass carp, but also for the first time revealed a novel function of fish Il-4/13 combined with M-csf engaging in M0/Mϕ proliferation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Laura Camacho-Jiménez, Monserrath Felix-Portillo, Dahlia M. Nuñez-Hernandez, Gloria Yepiz-Plascencia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hypoxia is a common stressor for aquaculture species. The Pacific white shrimp 〈em〉Litopenaeus vannamei〈/em〉 survives low dissolved oxygen (DO) conditions by adjusting its energy metabolism. In vertebrates, the transcription factor p53 regulates glucose metabolism under stress through diverse target genes like the Tp53-induced glycolysis and apoptotic regulator (TIGAR), a protein similar to fructose-2,6-bisphosphatase that has a pro-survival role in cells participating in the defense against oxidative damage. Until now, TIGAR has been not reported in any invertebrate species, including crustaceans. In this work, we report the molecular cloning of the white shrimp TIGAR. The cDNA sequence is 765 bp encoding a 254 amino acid protein. Bioinformatics analyses predicted that although the overall sequence identities of 〈em〉L. vannamei〈/em〉 TIGAR and vertebrate proteins are not very high (33.61%–35.34%), they have a remarkable predicted structural similarity with full conservation of catalytic residues, secondary and three-dimensional structures. Gene expression analysis by RT-qPCR revealed that the mRNA abundance of TIGAR in white shrimp is tissue-specific under normal oxygen conditions, with higher expression in gills than hepatopancreas and muscle. Also, gene expression in gills and hepatopancreas is modified by environmental hypoxia, suggesting that TIGAR participates in the cellular tolerance of 〈em〉L. vannamei〈/em〉 to this stressor.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Rajamanthrilage Kasun Madusanka, Thanthrige Thiunuwan Priyathilaka, N.D. Janson, T.D.W. Kasthuriarachchi, Sumi Jung, M.D. Neranjan Tharuka, Jehee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Galectins are β-galactoside-binding lectins, which are involved in pattern recognition, cell adhesion, and stimulation of the host innate immune responses against microbial pathogens. In spite of several functional studies on different galectins isolated from vertebrates and invertebrates, this is the first report to present functional studies for galectin-8 from the marine teleost tissues. In the present study, we characterized galectin-8 homolog from black rockfish (〈em〉Sebastes schlegelii〈/em〉), in molecular and functional aspects. Rockfish galectin-8 (〈em〉SsGal8〈/em〉) was found to consist of a 969 bp long open reading frame (ORF), encoding a protein of 322 amino acids and the predicted molecular weight was 35.82 kDa. 〈em〉In silico〈/em〉 analysis of 〈em〉SsGal8〈/em〉 revealed the presence of two carbohydrate binding domains (CRDs), at both N and C-termini and a linker peptide of 40 amino acids, in between the two domains. As expected, the phylogenetic tree categorized 〈em〉SsGal8〈/em〉 as a tandem-repeat galectin, and ultimately positioned it in the sub-clade of fish galectin-8. rSsGal8 was able to strongly agglutinate fish erythrocytes and the inhibition of agglutination was successfully exhibited by lactose and 〈span〉d〈/span〉-galactose. Bacterial agglutination assay resulted in agglutination of both Gram (+) and Gram (−) bacteria, including 〈em〉Escherichia coli, Vibrio harveyi, Vibrio parahaemolyticus, Streptococcus parauberis, Lactococcus garvieae, Streptococcus iniae〈/em〉 and 〈em〉Vibrio tapetis.〈/em〉 The tissue distribution analysis based on qPCR assays, revealed a ubiquitous tissue expression of 〈em〉SsGal8〈/em〉 for the examined rockfish tissues, with the most pronounced expression in blood, followed by brain, intestine, head kidney and kidney. Furthermore, the mRNA transcription level of 〈em〉SsGal8〈/em〉 was significantly up-regulated in spleen, liver and head kidney, upon immune challenges with 〈em〉Streptococcus iniae〈/em〉, LPS and poly I:C, in a time dependent manner. Taken together, these findings strongly suggest the contribution of 〈em〉SsGal8〈/em〉 in regulating innate immune responses to protect the rockfish from bacterial infections.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xing-Wei Xiang, Jin-Xing Xiao, Yu-Fang Zhou, Bin Zheng, Zheng-Shun Wen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The black seabream (〈em〉Sparus macrocephlus〈/em〉) is an economically pivotal aquaculture species cultured in China and Southeast Asian countries. To understand the molecular immune mechanisms underlying the response to 〈em〉Vibrio parahaemolyticus〈/em〉, a comparative gene transcription analysis were performed with utilized fresh livers of 〈em〉V. parahaemolyticus〈/em〉-immunized 〈em〉Sparus macrocephlus〈/em〉 with a control group through RNA-Seq technology. A total of 256663 contigs were obtained after excluded the low-quality sequences and assembly. The average length of contigs collected from this research is 1066.93 bp. Furthermore, blast analysis indicates 30747 contigs were annotated based on homology with matches in the NT, NR, gene, and string databases. A gene ontology analysis was employed to classify 21598 genes according to three major functional categories: molecular function, cellular component, and biological process. A total of 14470 genes were discovered in 303 KEGG pathways. RSEM and EdgeR were introduced to estimate 3841 genes significantly different expressed (False Discovery Rate〈0.001) which includes 4072 up-regulated genes and 3771 down-regulated genes. A significant enrichment analysis of these differentially expressed genes and isogenes were conducted to reveal the major immune-related pathways which refer to the toll-like receptor, complement, coagulation cascades, and chemokine signaling pathways. In addition, 92175 potential simple sequence repeats (SSRs) and 121912 candidate single nucleotide polymorphisms (SNPs) were detected and identified sequencely in the 〈em〉Sparus macrocephlus〈/em〉 liver transcriptome. This research characterized a gene expression pattern for normal and the 〈em〉V. parahaemolyticus〈/em〉 -immunized 〈em〉Sparus macrocephlus〈/em〉 for the first time and not only sheds new light on the molecular mechanisms underlying the host-〈em〉V. parahaemolyticus〈/em〉 interaction but contribute to facilitate future studies on 〈em〉Sparus macrocephlus〈/em〉 gene expression and functional genomics.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yi-Hong Chen, Jian-Guo He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The shrimp aquaculture industry is plagued by disease. Due to the lack of deep understanding of the relationship between innate immune mechanism and environmental adaptation mechanism, it is difficult to prevent and control the diseases of shrimp. The shrimp innate immune system has received much recent attention, and the functions of the humoral immune response and the cellular immune response have been preliminarily characterized. The role of environmental stress in shrimp disease has also been investigated recently, attempting to clarify the interactions among the innate immune response, the environmental stress response, and disease. Both the innate immune response and the environmental stress response have a complex relationship with shrimp diseases. Although these systems are important safeguards, allowing shrimp to adapt to adverse environments and resist infection, some pathogens, such as white spot syndrome virus, hijack these host systems. As shrimp lack an adaptive immune system, immunization therapy cannot be used to prevent and control shrimp disease. However, shrimp diseases can be controlled using ecological techniques. These techniques, which are based on the innate immune response and the environmental stress response, significantly reduce the impact of shrimp diseases. The object of this review is to summarize the recent research on shrimp environmental adaptation mechanisms, innate immune response mechanisms, and the relationship between these systems. We also suggest some directions for future research.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yinnan Mu, Shimin Zhou, Ning Ding, Jingqun Ao, Xinhua Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Chemokines are a superfamily of structurally related chemotactic cytokines exerting significant roles in regulating cell migration and activation. Currently, five subgroups of fish specific CXC chemokines, named CXCL_F1-CXCL_F5, have been identified in teleost fish. However, understanding of the functions of these fish specific CXC chemokines is still limited. Here, a new member of fish specific CXC chemokines, 〈em〉Lc〈/em〉CXCL_F6, was cloned from large yellow croaker 〈em〉Larimichthys crocea〈/em〉. Its open reading frame (ORF) is 369 nucleotides long, encoding a peptide of 122 amino acids (aa). The deduced 〈em〉Lc〈/em〉CXCL_F6 protein contains a 19-aa signal peptide and a 103-aa mature polypeptide, which has four conserved cysteine residues (C〈sup〉28〈/sup〉, C〈sup〉30〈/sup〉, C〈sup〉56〈/sup〉, and C〈sup〉72〈/sup〉), as found in other known CXC chemokines. Phylogenetic analysis showed 〈em〉Lc〈/em〉CXCL_F6 formed a separate clade with sequences from other fish species, tentatively named CXCL_F6, distinct from the clades formed by fish CXCL_F1-5 and mammalian CXC chemokines. The 〈em〉Lc〈/em〉CXCL_F6 transcripts were constitutively expressed in all examined tissues and significantly up-regulated in the spleen and head kidney tissues by poly (I:C) and 〈em〉Vibrio alginolyticus〈/em〉. Its transcripts were also detected in primary head kidney leukocytes (HKLs), peripheral blood leucocytes (PBLs), and large yellow croaker head kidney (LYCK) cell line, and significantly up-regulated by poly(I:C), lipopolysaccharide (LPS), and peptidoglycan (PGN) in HKLs. Recombinant 〈em〉Lc〈/em〉CXCL_F6 protein (r〈em〉Lc〈/em〉CXCL_F6) could not only chemotactically attract monocytes/macrophages and lymphocytes from PBLs, but also enhance NO release and expression of proinflammatory cytokines (TNF-α, IL-1β, and CXCL8) in monocytes/macrophages. These results indicate that 〈em〉Lc〈/em〉CXCL_F6 plays a role in mediating the inflammatory response.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Jinghua Chen, Lu Zhang, Ning Yang, Mengyu Tian, Qiang Fu, Fenghua Tan, Chao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Galectins are a family of galactoside-binding proteins with an affinity for β-galactosides, involved in mediating fundamental processes including development, inflammation, cell migration and apoptosis. Galectin-4 is a member of tendem-repeat galectins, plays vital roles in intestinal epithelial barrier. Here, one galectin-4 gene was captured in turbot (〈em〉Sm〈/em〉Lgals4) contains a 1197 bp open reading frame (ORF). In comparison to other species, 〈em〉Sm〈/em〉Lgals4 showed the highest similarity and identity both to large yellow croaker. The genomic structure analysis showed that 〈em〉Sm〈/em〉Lgals4 had conserved exons in the CRD domains compared to other vertebrate species. The syntenic analysis revealed that galectin-4 had the same neighboring genes across all the selected species, which suggested the synteny encompassing galectin-4 region during vertebrate evolution. Subsequently, 〈em〉Sm〈/em〉Lgals4 was widely expressed in all the examined tissues, with the highest expression level in intestine and the lowest expression level in skin. In addition, 〈em〉Sm〈/em〉Lgals4 was significantly down-regulated in intestine following both Gram-negative bacteria 〈em〉Vibrio anguillarum〈/em〉, and Gram-positive bacteria 〈em〉Streptococcus iniae〈/em〉 immersion challenge. Finally, the 〈em〉rSm〈/em〉Lgals4 showed strong binding ability to all the examined microbial ligands. Taken together, our results suggested 〈em〉Sm〈/em〉Lgals4 plays vital roles in fish intestinal immune responses against infection, but the detailed roles of galectin-4 in teleost are still lacking, further studies are needed to be carried out to characterize whether galectin-4 plays similar roles in teleost intestinal immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yanxiu Mo, Yunpeng Fan, Wen Fu, Wenting Xu, Shujuan Chen, Yuanhui Wen, Shaojun Liu, Liangyue Peng, Yamei Xiao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Previous research has indicated that the small compound, SP600125, could induce polyploidy of fish cells, and has established a stable tetraploid cell line from diploid fish cells. In order to explore how fish cells maintain homeostasis under SP600125-stress 〈em〉in vitro〈/em〉, this study investigates impacts of SP600125-stress on intracellular pathways, as well as on regulation of the cellular homeostasis feedback in fish cells. Transcriptomes are obtained from the SP600125-treated cells. Compared with unigenes expressed in control group (crucial carp fin cells), a total of 2670 and 1846 unigenes are significantly upregulated and downregulated in these cells, respectively. Differentially expressed genes are found, which are involved in innate defense, inflammatory pathways and cell adhesion molecules-related pathways. The SP600125-stress enhances cell-mediated immunity, characterized by significantly increasing expression of multiple immune genes. These enhanced immune genes include the pro-inflammatory cytokines (IL-1β, TNF-ɑ, IL-6R), the adaptor signal transducers (STAT, IκBɑ), and the integrins (ɑ2β1, ɑMβ2). Furthermore, mitochondria are contributed to the cellular homeostasis regulation upon the SP600125-stress. The results show that acute inflammation is an adaptive and controlled response to the SP600125-stress, which is beneficial for alleviating toxicity by SP600125. They provide a potential way of breeding fish polyploidy induced by SP600125 in the future research.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Maciej Woźny, Kazimierz Obremski, Piotr Hliwa, Piotr Gomułka, Rafał Różyński, Paweł Wojtacha, Maciej Florczyk, Helmut Segner, Paweł Brzuzan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To investigate the effects of feed contamination with zearalenone (ZEN) at the current European Commission (EC) guidance value (2 mg⋅kg〈sup〉−1〈/sup〉 feed) on the growth and health of rainbow trout, we performed a long-term feeding trial under aquaculture conditions. It started with the external feeding of the fish larvae, and continued for 96 weeks, at which point the fish had reached market size. To assess the growth of fish and their feeding efficiency throughout this period, the fish were regularly weighed and measured, and their feed consumption was monitored. Additionally, to investigate potential health effects, after 72 weeks of the exposure to ZEN, the fishes' blood was analyzed for major hematological and biochemical indices, and their head kidney, spleen, and liver were examined for morphological, histopathological, cytological, and molecular changes. Finally, to gain insight into the metabolism and distribution of ZEN in fish, the content of free and glucuronidated forms of ZEN and its major metabolites was measured in the intestine, liver, and muscles of the exposed fish. The feed-borne exposure of rainbow trout to ZEN at a dose of 2 mg⋅kg〈sup〉−1〈/sup〉 feed resulted in higher feeding efficiency and growth rate, most probably due to the anabolic properties of the ZEN metabolite. Importantly for the consumers of fish, despite absorption and metabolism of ZEN in the digestive system of the fish that had been exposed for 72 weeks, the residuals of ZEN were not transferred to the fishes’ muscles, which rules out a potential risk to human health related to the consumption of fish meat. However, the increased growth of fish fed with the contaminated feed may come at some cost, as the exposure to ZEN was associated with modulation of key components of the adaptive and innate immune systems. Moreover, the trunk kidney of ZEN-fed fish showed massive inflammation that was likely caused by pathogen infection. These findings raise concerns about fish health under the current recommended EC guidance values.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xin Cai, Chengbin Gao, Huanhuan Song, Ning Yang, Qiang Fu, Fenghua Tan, Chao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cathepsin Z (CTSZ) is a lysosomal cysteine protease of the papain superfamily. It participates in the host immune defense via phagocytosis, signal transduction, cell-cell communication, proliferation, and migration of immune cells such as monocytes, macrophages, and dendritic cells. In this study, we reported the identification of 〈em〉Sm〈/em〉CTSZ, a CTSZ homolog from turbot (〈em〉Scophthalmus maximus〈/em〉 L.). 〈em〉Sm〈/em〉CTSZ was 317 residues in length and contains a Pept-C1 domain. In multiple species comparison, 〈em〉Sm〈/em〉CTSZ shared 65–93% overall sequence identities with the CTSZ counterparts from human, rat, and several fish species. In the phylogenetic analysis, 〈em〉Sm〈/em〉CTSZ showed the closest relationship to 〈em〉Cynoglossus semilaevis〈/em〉. The syntenic analysis revealed the similar neighboring genes of CTSZ across all the selected species, which suggested the synteny encompassing CTSZ region during vertebrate evolution. Subsequently, 〈em〉Sm〈/em〉CTSZ was constitutively expressed in various tissues, with the lowest and highest levels in brain and intestine respectively. In addition, 〈em〉Sm〈/em〉CTSZ was significantly up-regulated in intestine following both Gram-negative bacteria 〈em〉Vibrio anguillarum〈/em〉, and Gram-positive bacteria 〈em〉Streptococcus iniae〈/em〉 immersion challenge. Finally, the 〈em〉rSm〈/em〉CTSZ showed strong binding ability to all the examined microbial ligands, and the agglutination effect to different bacteria. Taken together, these results indicated 〈em〉Sm〈/em〉CTSZ could play important roles in mucosal immune response in the event of bacterial infection in teleost. However, the knowledge of CTSZ are still limited in teleost species, further studies should be carried out to better characterize its detailed roles in teleost mucosal immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Zhi Zhou, Zhaoqun Liu, Lingui Wang, Jian Luo, Hailang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Giant clams are one of the most important animals in coral reef ecosystem, and its growth and reproduction are being threatened by heat stress due to global warming. In the present study, the symbiont density, the crucial enzyme activities and the transcriptome were investigated in the outer mantle of giant clam 〈em〉Tridacna crocea〈/em〉 after the acute exposure of high temperature. The density of symbiotic zooxanthellae decreased significantly during 12–24 h, with the minimum level (7.75 × 10〈sup〉5〈/sup〉 cell cm〈sup〉−2〈/sup〉, 〈em〉p〈/em〉 〈 0.05) at 12 h after heat stress. The activities of superoxide dismutase in the heat stress group was significantly lower than that in the control group at 24 h after heat stress, while no significant change in the activities of catalase was observed during the entire stress process. The activation level of caspase3 began to increase significantly at 12 h (1.22-fold, 〈em〉p〈/em〉 〈 0.05), and reached the highest level at 24 h (1.38-fold, 〈em〉p〈/em〉 〈 0.05) after heat stress. Six paired-end libraries were sequenced in two groups, including the heat stress and control group at 12 h after heat stress. Through the assembling of 187,116,632 paired-end reads with lengths of 2 × 150 bp, a total of 26,676 genes were obtained which derived from giant clam. Bioinformatics analysis revealed 47 significantly upregulated and 88 significantly downregulated genes at 12 h after the treatment. There were 12 overrepresented GO terms for significantly upregulated genes, mostly related to unfolded protein binding and ATP binding, whereas no GO term was overrepresented for significantly downregulated genes. These results collectively suggest high temperature could induce excessive oxidative stress through the repressed antioxidant ability, the apoptosis activated by the unfolded protein response, and further the collapse of the symbiosis between host and symbiont, which has been threatening the growth and reproduction of the giant clam 〈em〉T. crocea〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Zhi-qiang Du, Yue Wang, Hong-yu Ma, Xiu-li Shen, Kai Wang, Jie Du, Xiao-dong Yu, Wen-hong Fang, Xin-cang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Crustins play important roles in defending against bacteria in the innate immunity system of crustaceans. In present study, we identified a crustin gene in 〈em〉Scylla paramamosain〈/em〉, which was named as 〈em〉SpCrus6〈/em〉. The ORF of 〈em〉Sp〈/em〉Crus6 possessed a signal peptide sequence (SPS) at the N-terminus and a WAP domain at the C-terminus. And there were 5 Proline residues, 5 Glycine and 4 Cysteine residues between SPS and WAP domain in 〈em〉Sp〈/em〉Crus6. These features indicated that 〈em〉Sp〈/em〉Crus6 was a new member of crustin family. The 〈em〉SpCrus6〈/em〉 mRNA transcripts were up-regulated obviously after bacteria or virus challenge. These changes showed that 〈em〉SpCrus6〈/em〉 was involved in the antimicrobial and antiviral responses of 〈em〉Scylla paramamosain〈/em〉. Recombinant 〈em〉Sp〈/em〉Crus6 (r〈em〉Sp〈/em〉Crus6) showed strong inhibitory abilities against Gram-positive bacteria (〈em〉Bacillus megaterium〈/em〉, 〈em〉Staphylococcus aureus〈/em〉, and 〈em〉Bacillus subtilis〈/em〉). But the inhibitory abilities against four Gram-negative bacteria (〈em〉Vibrio parahemolyticus〈/em〉, 〈em〉Vibrio alginolyticus〈/em〉, 〈em〉Vibrio harveyi〈/em〉 and 〈em〉Escherichia coli〈/em〉) and two fungi (〈em〉Pichia pastoris〈/em〉 and 〈em〉Candida albicans〈/em〉) were not strong enough. Besides, r〈em〉Sp〈/em〉Crus6 could strongly bind to two Gram-positive bacteria (〈em〉B〈/em〉. 〈em〉subtilis〈/em〉 and 〈em〉B〈/em〉. 〈em〉megaterium〈/em〉) and three Gram-negative bacteria (〈em〉V〈/em〉. 〈em〉alginolyticus〈/em〉, 〈em〉V〈/em〉. 〈em〉parahemolyticus〈/em〉, and 〈em〉V〈/em〉. 〈em〉harveyi〈/em〉). And the binding levels to 〈em〉S. aureus〈/em〉 and two fungi (〈em〉P〈/em〉. 〈em〉pastoris〈/em〉 and 〈em〉C〈/em〉. 〈em〉albicans〈/em〉) were weak. The polysaccharides binding assays’ results showed r〈em〉Sp〈/em〉Crus6 had superior binding activities to LPS, LTA, PGN and 〈em〉β〈/em〉-glucan. Through agglutinating assays, we found r〈em〉Sp〈/em〉Crus6 could agglutinate well three Gram-positive bacteria (〈em〉S〈/em〉. 〈em〉aureus〈/em〉, 〈em〉B〈/em〉. 〈em〉subtilis〈/em〉 and 〈em〉B〈/em〉. 〈em〉megaterium〈/em〉). And the agglutinating activities to Gram-negative bacteria and fungi were not found. In the aspect of antiviral functions, r〈em〉Sp〈/em〉Crus6 could bind specifically to the recombinant envelop protein 26 (rVP26) of white spot syndrome virus (WSSV) but not to recombinant envelop protein 28 (rVP28), whereas GST protein could not bind to rVP26 or rVP28. Besides, r〈em〉Sp〈/em〉Crus6 could suppress WSSV reproduction to some extent. Taken together, 〈em〉Sp〈/em〉Crus6 was a multifunctional immunity effector in the innate immunity defending response of 〈em〉S〈/em〉. 〈em〉paramamosain〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yunkun Li, Jiayu Wu, Dong Li, Anqi Huang, Guixian Bu, Fengyan Meng, Fanli Kong, Xiaohan Cao, Xingfa Han, Xiaofu Pan, Wei Fan, Shiyong Yang, Xianyin Zeng, Xiaogang Du〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Schizothorax prenanti〈/em〉 (〈em〉S. prenanti〈/em〉), an important species of economical fish in Southwest China, is susceptible to 〈em〉Aeromonas hydrophila〈/em〉 (Ah). To understand the immune response to Ah, the transcriptome profiling of spleen of 〈em〉S. prenanti〈/em〉 was analyzed after Ah infection. A total of 6, 213 different expression genes (DEGs) were obtained, including 3, 066 up-regulated DEGs and 3, 147 down-regulated DEGs. These DEGs were annotated by KEGG and GO databases, so that the immune-related DEGs (IRDs) can be identified and classified. Then, the interesting IRDs were screened to build heat map, and the reliability of the transcriptome data was validated by qPCR. In order to clarify the mechanism of signal transduction in the anti-bacterial immunity, the signaling pathway initiated by TLRs was predicted. In this pathway, TLR25 and TLR5 mediate the NF-κB and AP-1 signals via MyD88-dependent pathway. Meanwhile, the type I IFN (IFNα/β) induced by IRF1 and IRF3/7 may play an important role in the anti-bacterial immunity. In conclusion, this study preliminarily provides insights into the mechanism of signal transduction after Ah infection in 〈em〉S. prenanti〈/em〉, which contributes to exploring the complex anti-bacterial immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Hongye Jiang, Qing Bian, Weiwei Zeng, Pengli Ren, Hengchang Sun, Zhipeng Lin, Zeli Tang, Xinyi Zhou, Qing Wang, Yingying Wang, Yensheng Wang, Mei X. Wu, Xuerong Li, Xinbing Yu, Yan Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Grass carp (〈em〉Ctenopharyngodon idellus〈/em〉) hemorrhagic disease (GCHD), caused by grass carp reovirus (GCRV), has given rise to an enormous loss in grass carp industry during the past years. Up to date, vaccination remained to be the most effective way to protect grass carp from GCHD. Oral vaccination is of major interest due to its advantages of noninvasive, time-saving, and easily-operated. The introduction of oral vaccination has profound impact on aquaculture industry because of its feasibility of extensive application for fish in various size and age. However, the main challenge in developing oral vaccine is that antigens are easily degraded and are easy to induce tolerance. 〈em〉Bacillus subtilis〈/em〉 (〈em〉B. subtilis〈/em〉) spores would be an ideal oral vaccine delivery system for their robust specialty, gene operability, safety and adjuvant property. VP4 protein is the major outer capsid protein encoded by GCRV segment 6 (S6), which plays an important role in viral invasion and replication. In this study, we used 〈em〉B. subtilis〈/em〉 spores as the oral delivery system and successfully constructed the 〈em〉B. subtilis〈/em〉 CotC-VP4 recombinant spores (CotC-VP4 spores) to evaluate its protective efficacy in grass carp. Grass carp orally immunized with CotC-VP4 spores showed a survival rate of 57% and the relative percent survival (RPS) of 47% after the viral challenge. Further, the specific IgM levels in serum and the specific IgZ levels in intestinal mucus were significantly higher in the CotC-VP4 group than those in the Naive group. The immune-related genes including three innate immune-related genes (IL-4/13A, IL-4/13B, CSF1R), four adaptive immune-related genes (BAFF, CD4L, MHC-II, CD8), three inflammation-related genes (IL-1β, TNF-α, TGF-β) and interferon type I (IFN-I) related signaling pathway genes were significantly up-regulated in the CotC-VP4 group. The study demonstrated that the CotC-VP4 spores produced protection in grass carp against GCRV infection, and triggered both innate and adaptive immunity post oral immunization. This work highlighted that 〈em〉Bacillus subtilis〈/em〉 spores were powerful platforms for oral vaccine delivery, and the combination of 〈em〉Bacillus subtilis〈/em〉 spores with GCRV VP4 protein was a promising oral vaccine.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Guang-hua Wang, Jing-jing Wang, Bin Yue, Xue Du, He-he Du, Min Zhang, Yong-hua Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High-mobility group box 2 (HMGB2) is a non-histone chromosomal protein that involved diverse functions such as transcriptional regulation and innate immune responses in mammalian. In teleost, very limited studies on HMGB2 proteins have been documented. Black rockfish (〈em〉Sebastes schlegelii〈/em〉) is an economic fish species and cultured worldwide. However, the study of black rockfish about immunology is very scarce. In the present study, a HMGB2 homologue gene (〈em〉SsHMGB2〈/em〉) was identified and characterized in black rockfish. The open reading frame of 〈em〉SsHMGB2〈/em〉 is 648 bp, and the deduced amino acid sequence of 〈em〉SsHMGB2〈/em〉 shares 74.4%–91.2% overall sequence identities with the HMGB2 proteins of several fish species. In silico analysis identified several conserved features, including two basic HMG boxes and an acidic C-terminal tail composed of 24 Asp/Glu residues. Expression of 〈em〉SsHMGB2〈/em〉 occurred in multiple tissues and was upregulated during pathogens infection. Recombinant SsHMGB2 (rSsHMGB2) exhibited apparent binding activities against DNA. 〈em〉In vivo〈/em〉 studies showed that the expressions of multiple immune-related genes in head kidney were significantly enhanced when black rockfish were treated with rSsHMGB2. Furthermore, rSsHMGB2 reduced pathogen dissemination and replication in fish kidney and spleen. Taken together, these results suggest that SsHMGB2 possesses apparent immunoregulatory properties and played a role in fighting bacterial infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Sai-Wei Chen, Chun-Hung Liu, Shao-Yang Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bacteria-induced diseases are a major cause of mortality in aquaculture. Probiotics have commonly been used to replace antibiotics for prophylactic biocontrol in aquaculture. In the present study, 〈em〉Paenibacillus ehimensis〈/em〉 NPUST1 was isolated from a tilapia culture pond. This probiotic has bacteriocin-like activities against 〈em〉Aeromonas hydrophila〈/em〉 and was characterized by biochemical analysis and 16S rDNA sequencing. The physiochemical properties of a crude extract of the bacteriocin-like substance revealed low pH and high thermal tolerance. The substance exhibited broad-spectrum antimicrobial activity against diverse aquatic pathogens, food spoilage, clinical pathogens, and plant pathogens. The effect of dietary supplementation with 〈em〉P. ehimensis〈/em〉 NPUST1 was evaluated in regard to the growth of Nile tilapia (〈em〉Oreochromis niloticus〈/em〉) and immunity against pathogenic infection. The results showed significantly increased weight gain (WG), feed conversion ratio (FCR), and feed efficiency (FE) in Nile tilapia fed 〈em〉P. ehimensis〈/em〉 NPUST1 for 2 months compared with fish fed a control diet. When challenged with 〈em〉A. hydrophila〈/em〉 and 〈em〉S. iniae,〈/em〉 the fish fed 〈em〉P. ehimensis〈/em〉 NPUST1 also exhibited a higher survival rate than fish fed the control diet. The immune parameters revealed that the 〈em〉P. ehimensis〈/em〉 NPUST1-fed fish had significantly higher phagocytic activity, respiratory burst, and superoxide dismutase (SOD) of the head kidney leukocytes, as well as higher serum lysozyme activity and expression of cytokines TNF-α and IL-1β than the fish fed the control diet. These results indicate that dietary supplementation with 〈em〉P. ehimensis〈/em〉 NPUST1 improved the growth performance, immunity, and disease resistance in Nile tilapia.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Cheng-cai Zheng, Xin-yi Cai, Meng-meng Huang, Idefonce Mkingule, Cong Sun, Shi-Chao Qian, Zhen-ju Wu, Bing-nan Han, Hui Fei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Japanese eel (〈em〉Anguilla japonica〈/em〉) has become a commercially important fish species all over the world. High-density aquaculture has led to congestion and contributed to bacterial infection outbreaks that have caused high mortality. Therefore a 56-days feeding trial was conducted to determine the effects of dietary 〈em〉Bacillus amyloliquefaciens〈/em〉 (GB-9) and 〈em〉Yarrowia lipolytica〈/em〉 lipase2 (YLL2) on growth performance, digestive enzymes activity, innate immunity and resistance to pathogens of 〈em〉A. japonica〈/em〉. Fish growth performance was significantly affected by dietary YLL2 supplementation but not by GB-9. Fish fed diets with YLL2 at 2.0 g/kg diet in combination of high and low levels of GB-9 (5.0 g/kg and 2.0 g/kg) produced the highest growth. For digestive enzyme, lipase and trypsin activities was promoted by dietary containing YLL2, while amylase activities was increased by dietary containing YLL2, GB-9 single or combination. For innate immunity, the mucus lysozyme activity, leukocytes phagocytosis activity and reactive oxygen species level of skin, peroxidase and lysozyme activity of serum were enhanced in fish fed with GB-9 compared to those in control group (p 〈 0.05). The highest resistance to 〈em〉Vibrio anguillarum〈/em〉 and 〈em〉Aeromonas hydrophila〈/em〉 was determined in fish fed with 5.0 g kg〈sup〉−1〈/sup〉 GB-9 + 2.0 g/kg YLL2. This study demonstrated that GB-9 and YLL2 enhanced non-specific immune defense system of 〈em〉A. japonica〈/em〉, providing them with higher resistance to pathogens. The present results suggested that the combination of these supplements could be considered as potential biological additives for aquaculture farmed fish.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xianyong Bu, Xuqiu Lian, Yi Wang, Chengzeng Luo, Shengqiang Tao, Yilu Liao, Jiaming Yang, Aijing Chen, Yuhong Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of the present study was to investigate effects of dietary yeast culture on immune response related to TLR2-MyD88-NF-kβ signaling pathway, antioxidant capability and disease resistance against 〈em〉Aeromonas hydrophila〈/em〉 for Ussuri catfish (〈em〉Pseudobagrus ussuriensis〈/em〉). A total of 240 Ussuri catfish (mean weight of 7.39 ± 0.32 g) were randomly distributed into four groups that fed diets containing 0 (Y0), 10 (Y1), 20 (Y2) and 30 (Y3) g kg〈sup〉−1〈/sup〉 yeast culture for 8 weeks. The results indicated that dietary 10 g kg〈sup〉−1〈/sup〉 yeast culture supplementation significantly down-regulated mRNA levels of TLR2, MyD88, NF-kβ p65, IL-1β and IL-8 in the liver tissue compared with the control group (〈em〉P〈/em〉 〈 0.05). Simultaneously, serum lysozyme (LZM) activity, respiratory burst activity (RBA) of phagocytes, plasma alkaline phosphatase (AKP) activity and immunoglobulin M (IgM) content were significantly improved in fish fed Y1 diet (〈em〉P〈/em〉 〈 0.05). Fish fed Y1 diet had significantly higher serum alternative complement pathway activity (ACH50) and plasma complement 3 (C3) content than the Y3 group (〈em〉P〈/em〉 〈 0.05). However, no significant differences were observed in plasma acid phosphatase (ACP) activity and complement 4 (C4) content among the groups (〈em〉P〈/em〉 〉 0.05). Fish cumulative mortality rate (CMR) in the Y1 and Y2 groups were significantly lower than that in Y0 and Y3 groups (〈em〉P〈/em〉 〈 0.05), and the lowest CMR was observed in the Y1 group after challenge by 〈em〉A. hydrophila〈/em〉. The highest hepatic superoxide dismutase and glutathione peroxidase activities, total antioxidant capacity and the lowest malondialdehyde content were found in Y1 group, but no significant difference was found in hepatic catalase activity among the groups (〈em〉P〈/em〉 〉 0.05). These results demonstrate that dietary 10 g kg〈sup〉−1〈/sup〉 yeast culture could effectively improve the immunity, antioxidant capability and disease resistance against 〈em〉A. hydrophila〈/em〉 for Ussuri catfish and could down-regulate the mRNA expression levels of pro-inflammatory cytokines modulated by TLR2-MyD88-NF-kβ signaling pathway.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Tao Wang, Xin Wen, Yadong Hu, Xinyu Zhang, Dan Wang, Shaowu Yin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Copper nanoparticles (Cu NPs) are a new pollutant in aquaculture, representing a hazard to aquatic organisms. We investigated the effects of Cu NPs exposure on oxidative stress, apoptosis and immune response in an economically important model species, 〈em〉Takifugu fasciatus〈/em〉. The juvenile fish were exposed to control, 20 or 100 μg Cu NPs/L for 30 days. The growth of 〈em〉T. fasciatus〈/em〉 was inhibited after Cu NPs exposure. Copper accumulation in liver increased with increasing Cu NPs dose. Oxidative stress indicators [malondialdehyde (MDA), total superoxide dismutase (T-SOD), catalase (CAT) and glutathione (GSH)], apoptosis index and activities of caspases (caspase-3, caspase-9) were all increased with the increase of Cu NPs concentration in liver. With an increase in Cu NPs dose, the activities of succinate dehydrogenase (SDH) and Na〈sup〉+〈/sup〉-K〈sup〉+〈/sup〉-ATPase as well as cytochrome c (Cyt-c) concentration in mitochondria decreased, accompanied by increased Cyt-c concentration in cytosol. Apoptosis-related gene expressions of 〈em〉p53〈/em〉, 〈em〉caspase-3〈/em〉, 〈em〉caspase-9〈/em〉 and 〈em〉Bax〈/em〉 were increased with the increase of Cu NPs dose. However, the opposite result was found in 〈em〉Bcl2〈/em〉 expression. The physiological indicators of immune response [heat shock protein 70 (HSP70), heat shock protein 90 (HSP90), immunoglobulin M (IgM) and lysozyme (LZM)] as well as the mRNA levels of 〈em〉HSP70〈/em〉, 〈em〉HSP90〈/em〉, 〈em〉IgM〈/em〉 and 〈em〉C-LZM〈/em〉 were all increased after Cu NPs exposure〈em〉.〈/em〉 Our results will be helpful in understanding the mechanism of Cu NPs toxicity in 〈em〉T. fasciatus〈/em〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1050464818306867-fx1.jpg" width="278" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Junguo Ma, Xi Chen, Guangyuan Xin, Xiaoyu Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study aimed to determine the chronic toxicity of 1-methyl-3-octylimidazolium bromide ([C〈sub〉8〈/sub〉mim]Br) on the silver carp to further reveal the toxicological mechanisms of ionic liquids. Chronic exposure of silver carp to [C〈sub〉8〈/sub〉mim]Br at concentrations of 1.095 and 4.380 mg/L for 60 d was conducted under laboratory conditions. The results revealed that chronic exposure to [C〈sub〉8〈/sub〉mim]Br inhibited the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and reduced glutathione (GSH) levels while markedly increasing malondialdehyde (MDA) and protein carbonyl (PC) levels in fish spleen, indicating that [C〈sub〉8〈/sub〉mim]Br treatment induced oxidative stress. Additionally, long-term exposure to [C〈sub〉8〈/sub〉mim]Br markedly upregulated the expressions of nuclear factor-κB (NF-κB), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), IL-6, tumour necrosis factor-α (TNF-α), and interferon-γ (IFN-γ); altered the levels of transforming growth factor-β (TGF-β); and increased the mRNA levels of p38MAPK, c-fos, c-jun, and c-myc, suggesting that long-term exposure to [C〈sub〉8〈/sub〉mim]Br might promote the inflammatory response in fish spleen and that p38MAPK/NF-κB signalling may potentially be involved in this process. Moreover, [C〈sub〉8〈/sub〉mim]Br-exposure altered lysozyme activity and complement 3 (C3) and immunoglobulin M (IgM) content, indicating that chronic [C〈sub〉8〈/sub〉mim]Br exposure also has immunotoxic effects on silver carp. Furthermore, we also found that [C〈sub〉8〈/sub〉mim]Br exposure reduced miR-125b levels, altered miR-143 levels, and upregulated miR-155 and miR-21 levels, suggesting that these miRNAs may be involved in the [C〈sub〉8〈/sub〉mim]Br-induced inflammatory response in fish spleen. In summary, the present study indicates that chronic exposure to [C〈sub〉8〈/sub〉mim]Br induces inflammation in fish spleen and that oxidative stress-mediated p38MAPK/NF-κB signalling and miRNAs may play a key role in this process.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Chaozheng Li, Shaoping Weng, Jianguo He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As invertebrates, shrimps rely on multiple innate defense reactions, including humoral immunity and cellular immunity to recognize and eliminate various invaders, such as viruses. White spot syndrome virus (WSSV) causes the most prevalent and devastating viral disease in penaeid shrimps, which are the most widely cultured species in the coastal waters worldwide. In the last couple of decades, studies about WSSV implicate a dual role of the immune system in protecting shrimps against the infection; these studies also explore on the pathogenesis of WSSV infection. Herein, we review our current knowledge of the innate immune responses of shrimps to WSSV, as well as the molecular mechanisms used by this virus to evade host immune responses or actively subvert them for its own benefit. Deciphering the interactions between WSSV and the shrimp host is paramount to understanding the mechanisms that regulate the balance between immune-mediated protection and pathogenesis during viral infection and to the development of a safe and effective WSSV defensive strategy.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xin Zhang, Jialong Shi, Yulong Sun, Yusuf Jibril Habib, Huiping Yang, Ziping Zhang, Yilei Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years, the abalone aquaculture industry has been threatened by the deteriorating environmental conditions, such as hypoxia and thermal stress in the hot summers. It is necessary to investigate the molecular mechanism in response to these environmental challenges, and subsequently understand the immune defense system. In this study, the transcriptome profiles by RNA-seq of hemocytes from the small abalone 〈em〉Haliotis diversicolor〈/em〉 after exposure to hypoxia, thermal stress, and hypoxia plus thermal stress were established. A total of 103,703,074 clean reads were obtained and 99,774 unigenes were assembled. Of the 99,774 unigenes, 47,154 and 20,455 had homologous sequences in the Nr and Swiss-Prot protein databases, while 16,944 and 10,840 unigenes could be classified by COG or KEGG databases, respectively. RNAseq analysis revealed that the differentially expressed genes (DEGs) after challenges of hypoxia, thermal stress, or hypoxia plus thermal stress were 24,189, 29,165 and 23,665, among which more than 3000 genes involved in at least 230 pathways, including several classical immune-related pathways. The genes and pathways that were involved in immune response to hypoxia/thermal challenges were identified by transcriptome analysis and further validated by quantitative real-time PCR and RNAi technology. The findings in this study can provide information on 〈em〉H. diversicolor〈/em〉 innate immunity to improve the abalone aquaculture industry, and the analysis of the potential immune-related genes in innate immunity signaling pathways and the obtained transcriptome data can provide an invaluable genetic resource for the study of the genome and functional genes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Thanthrige Thiunuwan Priyathilaka, S.D.N.K. Bathige, Seongdo Lee, Bo-Hye Nam, Jehee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Toll-like receptors (TLRs) are well-known pattern recognition receptors that play key immunological roles in a diverse range of organisms. In this study, two novel invertebrate TLRs from disk abalone (designated as AbTLR-A and AbTLR-B) were identified and functionally characterized for the first time. AbTLR-A and AbTLR-B comprised the typical TLR domain architecture containing an extracellular leucine-rich repeat domain, transmembrane domain, and Toll/interleukin-1 receptor domain. Expressional analysis revealed that both TLRs were constitutively expressed at all the early embryonic stages of disk abalone analyzed, with the highest level of 〈em〉AbTLR-A〈/em〉 found at the 16-cell stage and 〈em〉AbTLR-B〈/em〉 at the trochophore stage. According to tissue distribution analysis, prominent mRNA expression of 〈em〉AbTLR-A〈/em〉 and 〈em〉AbTLR-B〈/em〉 was detected in the hemocytes and gills, respectively. 〈em〉AbTLR-A〈/em〉 and 〈em〉AbTLR-B〈/em〉 mRNAs were significantly up-regulated in response to Gram-negative 〈em〉Vibrio parahemolyticus〈/em〉, Gram-positive 〈em〉Listeria monocytogenes〈/em〉, and viral hemorrhagic septicemia virus injections in abalone hemocytes and gills. Overexpression of AbTLR-A and AbTLR-B in HEK293T cells directly activated nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) responsive reporters. Neither TLRs showed a high response to pathogen-associated molecular patterns 〈em〉in vitro〈/em〉. Co-expression of AbTLR-A and AbTLR-B with AbMyD88-2 and AbMyD88-X activated NF-κB-responsive reporters in a synergetic manner. These findings demonstrate the involvement of AbTLR-A and AbTLR-B in abalone innate immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Mona Saleh, Gokhlesh Kumar, Abdel-Azeem S. Abdel-Baki, Mohamed A. Dkhil, Mansour El-Matbouli, Saleh Al-Quraishy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Ichthyophthirius multifiliis〈/em〉, a ciliated protozoan parasite, causes ichthyophthiriasis and leads to considerable economic losses to the aquaculture industry. Understanding the fish immune response and host-parasite interactions could support developing novel strategies for better disease management and control. Fish skin mucus is the first line of defence against infections through the epidermis. Yet, the common carp, 〈em〉Cyprinus carpio〈/em〉, protein-based defence strategies against infection with 〈em〉I. multifiliis〈/em〉 at this barrier remain elusive. The skin mucus proteome of common carp was investigated at 1 day and 9 days post-exposure with 〈em〉I. multifiliis〈/em〉. Using nano-LC ESI MS/MS and statistical analysis, the abundance of 19 immune related and signal transduction proteins was found to be differentially regulated in skin mucus of common carp in response to 〈em〉I. multifiliis〈/em〉. The analysis revealed increased abundance values of epithelial chloride channel protein, galactose-specific lectin nattection, high choriolytic enzyme 1 (nephrosin), lysozyme C, granulin and protein-glutamine gamma-glutamyltransferase 2 in 〈em〉I. multifiliis-〈/em〉exposed carp skin mucus. Multiple lectins and a diverse array of distinct serpins with protease inhibitor activity were identified likely implicated in lectin pathway activation and regulation of proteolysis, indicating that these proteins contribute to the carp innate immune system and the protective properties of skin mucus. The results obtained from this proteomic analysis enables a better understanding of fish host response to parasitic infection and gives insights into the key role skin mucus plays in protecting fish against deleterious effects of 〈em〉I. multifiliis〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Fufa Qu, Jianzhou Tang, Jinting Liao, Bei Chen, Peng Song, Wenjie Luo, Ding Xiong, Tianting Liu, Qianting Gao, Shuangqing Lu, Zhen Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mitogen-activated protein kinase kinase 6 (MKK6) is an essential component of the p38MAPK signaling pathway, which is involved in the modulation of inflammation, cell apoptosis and survival responses in mammals. However, the function of MKK6s in teleosts is still unclear. In this study, a fish MKK6 homolog (〈em〉Ci〈/em〉MKK6) was first identified from the grass carp (〈em〉Ctenopharyngodon idella〈/em〉), a freshwater fish. 〈em〉Ci〈/em〉MKK6 cDNA encodes a putative protein of 357 amino acids that contains conserved structural characteristics of the MKK6 family, including the S_TKc domain, SVAKT motif and DVD site. The deduced 〈em〉Ci〈/em〉MKK6 protein exhibits high sequence homology with other reported fish MKK6s and shares the closest relationship with MKK6 from 〈em〉Danio rerio〈/em〉. Quantitative real-time PCR (qRT-PCR) analysis revealed that 〈em〉Ci〈/em〉MKK6 mRNA was widely expressed in all tested tissues and stages of embryonic development. Additionally, the transcript levels of 〈em〉Ci〈/em〉MKK6 in the intestine were significantly upregulated in response to bacterial muramyl dipeptide (MDP) and L-Ala-γ-D-Glu-meso-diaminopimelic acid (Tri-DAP) stimulation. Moreover, subcellular localization analysis indicated that 〈em〉Ci〈/em〉MKK6 was distributed in both the cytoplasm and the nucleus of HEK293T cells. Finally, overexpression of 〈em〉Ci〈/em〉MKK6 significantly enhanced the transcriptional activity of the AP-1 reporter gene in HEK293T cells. Overall, these findings may help better clarify the immune function of teleost MKK6s and provide new insight into the immune defense mechanisms of grass carp.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Liting Wu, Shengli Fu, Xiaoxue Yin, Wenna Leng, Zheng Guo, Anli Wang, Jianmin Ye〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Affinity maturation of the antibody response, a process of antibody affinity increasing over response, is one of the key features of the mammalian immune system. However, the process is incompletely understood in teleost, including channel catfish (〈em〉Ictalurus punctaus〈/em〉). In this study, IgM affinity maturation in channel catfish was investigated by estimating the kinetics of antibody affinity using ELISA and ELISPOT assays. Fish were immunized with a T-cell dependent antigen (TNP-KLH), and individual serum IgM antibody titers and affinities, and IgM〈sup〉+〈/sup〉 antibody-secreting cells (ASCs) in peripheral blood were analyzed over a period of 14 weeks. A detectable serum anti-TNP response developed by 2-weeks post-immunization, and the maximal antibody production was observed by 6-weeks post-immunization. The average affinity of anti-TNP serum antibody increased consistently and reached the maximum by 10-weeks post-immunization. The increase of antibody affinity beyond the point of optimal antibody titer revealed that the affinity maturation of IgM antibody response occurred in channel catfish. Dissection of dynamics of individual affinity subpopulations indicated that a significant proportion of low affinity subpopulations appeared at early response, and high affinity subpopulations appeared predominantly at later, resulting in a 100-fold increase in affinity over response. Additional, TNP〈sup〉+〈/sup〉 IgM〈sup〉+〈/sup〉 ASCs was detected by 2-weeks post-immunization and achieved the maximal number by 6-weeks post-immunization. Using an inhibition ELISPOT assay, the findings of a consistent increase in the average affinity of secreted IgM antibody by peripheral blood ASCs, as the immune response progressed, confirmed the occurrence of the affinity maturation. Taken together, the results of this study indicated that affinity maturation occurred in channel catfish following immunization with a TD antigen TNP-KLH.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Weihua Gao, Shuai Li, Qiaoqing Xu, Dashi Zhu, Qin Zhang, Kai Luo, Wenbing Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The CXC chemokine receptors (CXCRs) play critical roles in innate and adaptive immune systems. In this study, six Asian swamp eel (〈em〉Monopterus albus〈/em〉) CXCRs (〈em〉Ma〈/em〉CXCR1–4) were identified and their molecular characterization and expression patterns were analyzed. The open reading frames (ORFs) of 〈em〉Ma〈/em〉CXCR1a, 〈em〉Ma〈/em〉CXCR1b, 〈em〉Ma〈/em〉CXCR2, 〈em〉Ma〈/em〉CXCR3a, 〈em〉Ma〈/em〉CXCR3b, and 〈em〉Ma〈/em〉CXCR4 were 1074 bp (base pairs), 1080 bp, 1125 bp, 1146 bp, 1083 bp, and 1140 bp, and encoded proteins of 357 aa (amino acids), 359 aa, 374 aa, 381 aa, 360 aa, and 379 aa, respectively. All these CXCRs have seven conserved transmembrane domains and four cysteines (with the exception of 〈em〉Ma〈/em〉CXCR3b). Multiple sequence alignment revealed that the 〈em〉Ma〈/em〉CXCRs possess a typical G-protein receptor family 1 signature and a DRY motif. There are also one to four potential N-glycosylation sites in the extracellular regions of the 〈em〉Ma〈/em〉CXCRs, mainly distributed in the N-terminus and extracellular hydrophilic loop (ECL) 2 region. Phylogenetic analysis demonstrated that the 〈em〉Ma〈/em〉CXCRs were clustered together with homologous proteins from other fish. Taken together with the amino acid identity and similarity analysis, these results suggested that the 〈em〉Ma〈/em〉CXCRs are conserved with other homologous genes, in which CXCR4 is more conserved than CXCR1–3. The 〈em〉Ma〈/em〉CXCRs loci showed conserved synteny among teleost fish, and we found that human CXCR1 shares a common ancestor with fish CXCR1a. 〈em〉Ma〈/em〉CXCRs were constitutively expressed in a wide range of tissues (especially in immune-related tissues) with different expression levels, suggesting that the 〈em〉Ma〈/em〉CXCRs have different roles in un-stimulated tissues, and may play vital roles under normal conditions. 〈em〉Ma〈/em〉CXCRs showed different fold changes in the spleen after 〈em〉Aeromonas veronii〈/em〉 and polyinosinic-polycytidylic acid (poly I:C) challenge, which suggested that 〈em〉Ma〈/em〉CXCR1a and 〈em〉Ma〈/em〉CXCR3a have longer antiviral activities compared with their antibacterial functions, and that 〈em〉Ma〈/em〉CXCR1b possesses stronger antiviral than antibacterial activity. 〈em〉Ma〈/em〉CXCR4 may play vital roles during bacterial and viral infection; however, 〈em〉Ma〈/em〉CXCR2 has relatively small effect in antibacterial and antiviral responses. The differential responses of these genes to bacteria and poly I:C implied the differences in the mechanisms of defense against viruses and bacteria.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Sarithaa Sellaththurai, Thanthrige Thiunuwan Priyathilaka, Jehee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Organisms possess a cellular antioxidant defense system inclusive of ROS scavengers to maintain the homeostasis of antioxidant levels. Catalase is a major ROS scavenger enzyme that plays a significant role in the antioxidant defense mechanism of organisms by reducing toxic hydrogen peroxide molecules into a nontoxic form of oxygen and water with a high turnover rate. In the present study, we performed molecular and functional characterization of the catalase homolog from 〈em〉Hippocampus abdominalis〈/em〉 (HaCat). The 〈em〉HaCat〈/em〉 cDNA sequence was identified as a 1578 bp ORF (open reading frame) that encodes a polypeptide of 526 amino acids with 59.33 kDa molecular weight. Its estimated pI value is 7.7, and it does not have any signal sequences. HaCat shared a conserved domain arrangement including the catalase proximal active site signature and heme ligand signature domain with the previously identified catalase counterparts. Phylogenetic analysis displayed close evolutionary relationships between HaCat and catalases from other teleost fish. According to our qPCR results, ubiquitous expression of 〈em〉HaCat〈/em〉 transcripts were observed in all the tested tissues with high expression in the kidney followed by liver. Significant modulations of 〈em〉HaCat〈/em〉 transcription were observed in blood, liver, and kidney tissues post-challenge with 〈em〉Streptococcus iniae〈/em〉, 〈em〉Edwardsiella tarda〈/em〉, poly I:C, and LPS. Peroxidase activity of recombinant HaCat (rHaCat) was evaluated using an ABTS assay and the ROS removal effect was further confirmed by oxidative DNA damage protection and cell viability assays. The rHaCat showed more than 97% activity over a temperature and pH range of 10 °C–40 °C and 5 to 6, respectively. The above results suggest that HaCat plays an indispensable role in the oxidative homeostasis of the seahorse during pathogenic attack.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 30 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Chunyan Zhao, Guangpeng Jiang, Shun Zhou, Guodong Wang, Zhenxia Sha, Yongjun Sun, Yunji Xiu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lysin motif (LysM) is involved in chitin, peptidoglycan and other structurally-related oligosaccharides recognition and binding, and it is important for the biological processes of responsing to bacterial and viral infections and pathogen defense. LysM is also a widely spread protein, ranging from prokaryotes to eukaryotes, including bacteria, plants and mammals. However, research of LysM in teleosts especially in marine fish was rarely scarce. In the present study, four novel LysM domain-containing proteins in turbot (〈em〉Scophthalmus maximus〈/em〉), named as 〈em〉SmLysMd1〈/em〉, 〈em〉SmLysMd2〈/em〉, 〈em〉SmLysMd3〈/em〉, and 〈em〉SmLysMd4〈/em〉, were cloned and identified firstly. The full-length cDNA of 〈em〉SmLysMd1〈/em〉 was 1235 bp with a 678 bp ORF, capable of encoding a peptide of 225 amino acids. The complete cDNA sequence of 〈em〉SmLysMd2〈/em〉 was 1273 bp, and contained a 675 bp ORF, encoding a predicted protein of 224 amino acids. The full-length of 〈em〉SmLysMd3〈/em〉 cDNA was 2132 bp, containing a ORF of 987 bp, with a ORF of encoding 328 amino acids. The full-length 〈em〉SmLysMd4〈/em〉 cDNA was 1115 bp contained a 888 bp ORF, encoding 295 amino acids. And all the four predicated proteins contained a specific LYSM domain. Moreover, 〈em〉SmLysMd1〈/em〉 and 〈em〉SmLysMd2〈/em〉 belong to the intracellular non-secretory types, and 〈em〉SmLysMd3〈/em〉 and 〈em〉SmLysMd4〈/em〉 belong to the anchored transmembrane types. In addition, the four 〈em〉SmLysMd〈/em〉 were ubiquitously expressed in all the examined tissues. Moreover, the 〈em〉SmLysMds〈/em〉 levels were up-regulated in muscle and liver, and had a reduce tendency immediately in different degree following 〈em〉Vibrio vulnificus〈/em〉 challenge, indicating that the turbot LysM could be participant in the immune responses to bacterial infections. The present result of LysM in turbot for the first time in a marine fish will provide foundation knowledge for the functions studies of LysM in immune responses. Further studies should be carried out to better understand their immune mechanism in turbot and other teleosts.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 88〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Muhammad Nadeem Abbas, Saima Kausar, Hongjuan Cui〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Peroxiredoxins (Prxs) are a widespread and greatly transcribed family of antioxidant proteins, which rapidly detoxify peroxynitrite, hydrogen peroxide and organic hydroperoxides. The Prxs family members also modulate various physiological functions, including cell growth, differentiation, embryonic development, immune response, apoptosis, lipid metabolism, and cellular homeostasis. In mammals, the physiological functions of Prxs have extensively been studied; however, the knowledge is scanty in their counterpart, aquatic invertebrates. In recent years, substantial progress has been made in our knowledge of Prxs physiological functions in aquatic invertebrates, which has raised interest in defining the contribution of immune responses and removal of reactive oxygen species. In this review, we describe the recent knowledge on the Prxs physiological function in immune responses and DNA protection activity in aquatic invertebrates.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1050464819302116-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Ping Wang, Zhanying Zhang, Zhongtian Xu, Baoying Guo, Zhi Liao, Pengzhi Qi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Toll-like receptors (TLRs) are a category of most well recognized pattern recognition molecules that act on an vital role in both innate and adaptive immunity. In the present study, a novel toll-like receptor (〈em〉Mc〈/em〉TLRw) was identified and characterized in thick shell mussel 〈em〉Mytilus coruscus. Mc〈/em〉TLRw possesses one intracellular Toll/interleukin-1 (IL-1) receptor (TIR) domain, one transmembrane region (TM), one leucine rich repeat N-terminal domain (LRR_NT) and a few of leucine-rich repeats (LRRs), which all are common in typical TLRs. 〈em〉Mc〈/em〉TLRw transcripts were constitutively expressed in all examined tissues with higher expression levels in immune related tissues, and were significantly induced in haemocytes with the challenges of live 〈em〉Vibrio alginolyticus〈/em〉, lipopolysaccharide (LPS), peptidoglycans (PGN) and β-glucan (GLU), but not induced by polyinosinic-polycytidylic acid (poly I:C). rMcTLRw exhibited affinity to LPS, PGN and GLU while no affinity to poly I:C. Further, the downstream of TLR signaling pathway myeloid differentiation factor 88a (MyD88a), interleukin-1 receptor-associated kinase-4 (IRAK4) and tumor necrosis factor receptor-associated factor 6 (TRAF6) were significantly repressed in 〈em〉Mc〈/em〉TLRw silenced mussels while challenged with LPS. These results collectively indicated that 〈em〉Mc〈/em〉TLRw is one member of TLR family and involved in immune response to against invaders by taking participate in TLR mediated signaling pathway.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Xiaorui Song, Ying Song, Miren Dong, Zhaoqun Liu, Weilin Wang, Lingling Wang, Linsheng Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Runx family is a kind of heteromeric transcription factors, which is defined by the presence of a runt domain. As transcriptional regulator during development and cell fate specification, Runx is best known for its critical roles in hematopoiesis. In the present study, a Runx transcription factor (designed as 〈em〉Cg〈/em〉Runx) was identified and characterized from the oyster 〈em〉Crassostrea gigas〈/em〉. The complete coding sequence of 〈em〉Cg〈/em〉Runx was of 1638 bp encoding a predicted polypeptide of 545 amino acids with one conserved runt domain, which shared high similarity with other reported Runx proteins. 〈em〉Cg〈/em〉Runx was highly expressed in hemocytes, gill and mantle both at the protein and nucleic acid levels. 〈em〉Cg〈/em〉Runx protein was localized specifically in the cell nuclei of hemocytes, and distributed at the tubule lumen of gill filament. During the larval developmental stages, the mRNA transcripts of 〈em〉Cg〈/em〉Runx gradually increased after fertilization, reached to a relative high level at the 8 cell embryos and the blastula stage of 2–4 hpf (hours post fertilization) (about 40-fold), and peaked at early trochophore larvae (10 hpf) (about 60-fold). Whole-mount immunofluorescence assay further revealed that the abundant immunofluorescence signals of 〈em〉Cg〈/em〉Runx distributed through the whole embryo at blastula stage (5 hpf), and progressively reduced with the development to a ring structure around the dorsal region in trochophore larvae (10 hpf). Scattered positive immunoreactivity signals finally appeared in the velum region of D-veliger larvae. After LPS and 〈em〉Vibrio splendidus〈/em〉 stimulations, the expression levels of 〈em〉CgRunx〈/em〉 mRNA in hemocytes were up-regulated significantly compared with that in the control (0 h), which were 2.98- and 2.46-fold (〈em〉p〈/em〉 〈 0.05), 2.67- and 1.5-fold (〈em〉p〈/em〉 〈 0.05), 2.36- and 1.38-fold (〈em〉p〈/em〉 〈 0.05) at 3 h, 6 h and 12 h, respectively. These results collectively suggested that 〈em〉Cg〈/em〉Runx involved in immune response and might participate in larvae hematopoiesis in oyster.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Cuihong You, Baojia Chen, Meng Wang, Shuqi Wang, Mei Zhang, Zhijie Sun, Aweya Jude Juventus, Hongyu Ma, Yuanyou Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Replacement of fish oil (FO) with vegetable oils (VO) in diets is economically desirable for the sustainable development of the aquaculture industry. However, inflammation provoked by FO replacement limited its widely application in fish industry. In order to understand the mechanism of VO-induced inflammation, this study investigated the impact of different dietary vegetable oils on the intestinal health and microbiome in carnivorous marine fish golden pompano (〈em〉Trachinotus ovatus〈/em〉). Three diets supplemented with fish oil (FO, rich in long-chain polyunsaturated fatty acids), soybean oil (SO, rich in 18:2n-6) and linseed oil (LO, rich in 18:3n-3), respectively, were fed on juvenile golden pompano for 8 weeks, and the intestinal histology, digestive enzymes activities, immunity and antioxidant indices as well as intestinal microbiome were determined. The results showed that dietary SO significantly impaired intestinal health, and decreased the number and height of intestinal folds, and muscle thickness, as well as the zonula occludens-1 (〈em〉zo-1〈/em〉) mRNA expression in intestine. Moreover, the two dietary VO significantly decreased the amylase and lipase activities in intestine, and reduced the trypsin activity in the dietary SO group. Furthermore, the two VO diets increased intestinal acid phosphatase (ACP) activity, while intestinal lysozyme (LZM) activity and serum diamine oxidase (DAO) activity in the SO group were also significantly increased (〈em〉P〈/em〉 〈 0.05). Analysis of the intestinal microbiota showed that the two VO diets significantly increased the abundance of intestinal potentially pathogenic bacteria (〈em〉Mycoplasma〈/em〉 and 〈em〉Vibrio〈/em〉) and decreased proportions of intestinal probiotics (〈em〉Bacillus and Lactococcus〈/em〉), especially in the dietary SO group. These results indicate that complete replacement of FO with VO in diets would induce intestinal inflammation and impair intestinal function, which might be due to changes in intestinal microbiota profiles, and that dietary SO would have a more negative effect compared to dietary LO on intestinal health in 〈em〉T. ovatus〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Hengwei Deng, Xiaopeng Xu, Lei Hu, Jingjing Li, Dandan Zhou, Shanshan Liu, Panpan Luo, Jianguo He, Shaoping Weng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉JAK/STAT signaling pathways are associated with the innate immune system and play important roles in mediating immune responses to virus infection. In this study, a Janus kinase gene from 〈em〉Scylla paramamosain〈/em〉 (〈em〉Sp〈/em〉JAK) was cloned and characterized. The full length of 〈em〉Sp〈/em〉JAK mRNA contains a 5′ untranslated region (UTR) of 304 bp, an open reading frame of 3300 bp and a 3′ UTR of 302 bp. The 〈em〉Sp〈/em〉JAK protein contains seven characteristic JAK homology domains (JH1 to JH7) and showed 60% identity (78% similarity), 20% identity (35% similarity), and 21% identity (37% similarity) to the 〈em〉Litopenaeus vannamei〈/em〉 JAK (〈em〉Lv〈/em〉JAK) protein, the 〈em〉Drosophila melanogaster〈/em〉 hopscotch protein, and the 〈em〉Homo sapiens〈/em〉 JAK2 protein, respectively. The mRNA of 〈em〉Sp〈/em〉JAK showed high expression in the brain and nerve but low expression in the hemocyte and muscle. Moreover, the expression of 〈em〉Sp〈/em〉JAK was significantly upregulated by stimulation with mud crab reovirus (MCRV), poly(I:C), and 〈em〉Vibrio parahaemolyticus〈/em〉. 〈em〉Sp〈/em〉JAK significantly activated the STAT of 〈em〉S. paramamosain〈/em〉 (〈em〉Sp〈/em〉STAT) to translocate to the nucleus of 〈em〉Drosophila〈/em〉 Schneider 2 cells. 〈em〉Sp〈/em〉JAK significantly enhanced the activity of the promoter of the WSSV wsv069 gene that was activated significantly by 〈em〉Sp〈/em〉STAT by acting on the STAT-binding DNA motif. These results suggest that 〈em〉Sp〈/em〉JAK activates the JAK/STAT pathway. Furthermore, silencing 〈em〉Sp〈/em〉JAK 〈em〉in vivo〈/em〉 resulted in the high mortality rate of MCRV-infected mud crabs and increased the viral load in tissues. Hence, 〈em〉Sp〈/em〉JAK could play an important role in defense against MCRV in mud crab.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology〈/p〉 〈p〉Author(s): Wen Yang, Chao Liu, Qingsong Xu, Chen Qu, Jiejie Sun, Shu Huang, Ning Kong, Xiaojing Lv, Zhaoqun Liu, Lingling Wang, Linsheng Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Beclin-1, the mammalian ortholog of yeast Atg6, plays essential roles in the regulation of various processes, including autophagy, apoptosis, embryonic development and immune responses in vertebrates. However, the information about Beclin-1 in invertebrates especially crustaceans is still very limited. In the present study, a novel Beclin-1 (designated as 〈em〉Es〈/em〉Beclin-1) was identified from Chinese mitten crab 〈em〉Eriocheir sinensis〈/em〉. The open reading frame of 〈em〉Es〈/em〉Beclin-1 cDNA was of 1275 bp, encoding a typical APG6 domain. The deduced amino acid sequence of 〈em〉Es〈/em〉Beclin-1 shared high similarity ranging from 42.9% to 63.6% with the previously identified Beclins. In the phylogenetic tree, 〈em〉Es〈/em〉Beclin-1 was firstly clustered with 〈em〉Drosophila melanogaster〈/em〉 Atg6 and then assigned into the branch of invertebrate Beclin-1. The mRNA transcripts of 〈em〉Es〈/em〉Beclin-1 were highly expressed in hepatopancreas, hemocytes and gill. After lipopolysaccharide (LPS) and 〈em〉Aeromonas hydrophila〈/em〉 stimulations, the relative mRNA expression of 〈em〉Es〈/em〉Beclin-1 in hemocytes was significantly increased from 3 to 24 h with the peak level of 4.70-fold (〈em〉p〈/em〉 〈 0.01) and 2.91-fold (〈em〉p〈/em〉 〈 0.01) at 6 h, respectively. 〈em〉Es〈/em〉Beclin-1 protein was diffusely distributed in the cytoplasm of crab hemocytes under normal conditions, whereas it displayed predominantly punctuate distribution after LPS stimulation. After 〈em〉Es〈/em〉Beclin-1 was interfered with specific 〈em〉Es〈/em〉Beclin-1-dsRNA, the mRNA transcripts of some antimicrobial peptides, including 〈em〉Es〈/em〉ALF2, 〈em〉Es〈/em〉LYZ, 〈em〉Es〈/em〉Crus and 〈em〉Es〈/em〉Crus2 in crab hemocytes were significantly decreased at 6 h post LPS stimulation. These results implicated that 〈em〉Es〈/em〉Beclin-1 played a role in regulating the antimicrobial peptide expressions in the immune response of 〈em〉E. sinensis〈/em〉.〈/p〉〈/div〉 〈/div〉