Publication Date:
2020
Description:
〈p〉Publication date: March 2020〈/p〉
〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 98〈/p〉
〈p〉Author(s): Yuyuan Wu, Junjun He, Gaoyou Yao, Haiying Liang, Xuemin Huang〈/p〉
〈div xml:lang="en"〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉Proteins in the tumor necrosis factor receptor (TNFR) superfamily play significant roles in many physiological and pathological events, such as inflammation, apoptosis, autoimmunity, and organogenesis. Here, two TNFR gene homologs (〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5〈/em〉) were identified in the pearl oyster 〈em〉Pinctada fucata martensii.〈/em〉 The predicted PmTNFR1 and PmTNFR5 protein sequences were 406 and 533 amino acids long, respectively, and both possessed motifs characteristic of the TNFR family, including a TNFR homology domain (CRD), a transmembrane domain (TM), and death domains. However, the predicted amino acid sequences of PmTNFR1 and PmTNFR5 had low identity (~16–23%) with sequences of vertebrate TNFR family proteins. Furthermore, PmTNFR5 had a death domain at the C-terminal, indicating that this protein may be a novel member of the TNFR superfamily. Constitutive 〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5〈/em〉 mRNA expression was detected in all six pearl oyster tissues tested, with comparatively greater transcript abundance in the hepatopancreas and gill. The gene expression levels of 〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5,〈/em〉 as well as those of downstream signaling molecules related to the NF-κB pathway (〈em〉RIP, TRAF2, TRAF3, IKK,〈/em〉 and 〈em〉NF-κB〈/em〉), were quantified in the gill after LPS challenge and in the hemocytes after nucleus insertion surgery using real-time PCR (qRT-PCR). We found that all genes were significantly upregulated at 6 h and 12 h post-injection, as well as at 15 d post-insertion. We used RNAi to inhibit the expression of the 〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5〈/em〉 genes. We then quantified the expression levels of 〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5〈/em〉, as well as downstream genes, using qRT-PCR. We found that RNAi inhibition of 〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5〈/em〉 downregulated the downstream genes (〈em〉RIP〈/em〉, 〈em〉TRAF2, TRAF3, IKK,〈/em〉 and 〈em〉NF-κB〈/em〉). Therefore, our results suggested that 〈em〉PmTNFR1〈/em〉 and 〈em〉PmTNFR5〈/em〉 mediate the NF-κB signaling pathway, and are closely related to immune defense, particularly allograft immunity, in the pearl oyster 〈em〉P. fucata martensii〈/em〉.〈/p〉〈/div〉
〈/div〉
Print ISSN:
1050-4648
Electronic ISSN:
1095-9947
Topics:
Biology
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Medicine
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