ALBERT

Description: Cord blood transplantation (CBT) has been considered a treatment modality to hematologic malignancies, marrow failure syndromes and genetic diseases. It has advantages such as immediate availability, lower risk of transmitting infections and higher tolerance to HLA disparities compared to bone marrow. The major drawbacks are slow hematopoietic recovery and a high incidence of graft failure or delayed engraftment, as a result of low stem progenitors (CD34+cells) yields. This study aimed at investigating if there was correlation between engraftment and number of total nucleated cells (TNC), number of CD34+ cells as well as number of granulocyte/monocyte colony forming units (CFU-GM) and erythroid burst forming units (BFU-E). Eighty four patients (age 0 to 55, M=7) with a variety of diseases (10 AML, 12 ALL, 31 Fanconi Anemia, 1 Hodgkin Lymphoma, 3 JMML, 3 Blackfan Diamond, 6 Wiskott Aldrich, 1 Krabbe Disease, 2 SAA, 4 CML, 3 Osteopetrosis, 3 SCID, 1 Diskeratosis Congenita, 1 Adrenoleukodystrophy, 1 Thalassemia Major, 1 Thrombocytopenia w/chromosome 7 monossomy) who underwent CBT were included in this study; 47.6% (40/84) of these patients had graft failure while 52.4% (44/84) showed successful engraftment. Regarding HLA-A, B and DRB1 matching, 20.2% (17/84) recipient/donor pairs were 6/6, 42.9% (36/84) were 5/6, 35.7% (30/84) were 4/6 and 1.2% (1/84) was 3/4. TNC and CD34+ cell counts in addition to hematopoeitic progenitor cells (CFU-GM and BFU-E) testing were performed in cord blood products after thawing and washing procedures. CD34+cells were analyzed by two color technique using FACS Calibur (San Jose, CA) and absolute counts were assessed by two-platform ISHAGE method. Colony assays for BFU-E and CFU-GM were performed by plating 3×104 mononuclear cells in methylcellulose medium with human recombinant cytokines (Methocult GF, Stem Cell Technologies); cultures were kept at 37°C in humidified incubator with 5% CO2 and after 14 days colonies were scored under an inverted microscope. Comparison of pre-thawing TNC [M=1.34×109(0.56–5.00)] and CD34+ [M=2.61×105/Kg (0.39–25.48)] cell counts, provided by cord blood banks, with post-thawing TNC [M=1.09×109(0.36–4.20)] and CD34+ [M=1.3×105/Kg(0.06–9.8)], performed by Wilcoxon signed rank test, showed a significant decrease in both cases (P

Description: Tumor necrosis factor alpha (TNF-α) production is abnormally high in Fanconi anemia (FA) cells and contributes to the hematopoietic defects seen in FA complementation group C–deficient (Fancc−/−) mice. Applying gene expression microarray and proteomic methods to studies on FANCC-deficient cells we found that genes encoding proteins directly involved in ubiquitinylation are overrepresented in the signature of FA bone marrow cells and that ubiquitinylation profiles of FA-C and complemented cells were substantially different. Finding that Toll-like receptor 8 (TLR8) was one of the proteins ubiquitinylated only in mutant cells, we confirmed that TLR8 (or a TLR8-associated protein) is ubiquitinylated in mutant FA-C cells and that TNF-α production in mutant cells depended upon TLR8 and the canonical downstream signaling intermediates interleukin 1 receptor–associated kinase (IRAK) and IκB kinase-alpha/beta. FANCC-deficient THP-1 cells and macrophages from Fancc−/− mice overexpressed TNF-α in response to TLR8 agonists but not other TLR agonists. Ectopically expressed FANCC point mutants were capable of fully complementing the mitomycin-C hypersensitivity phenotype of FA-C cells but did not suppress TNF-α overproduction. In conclusion, FANCC suppresses TNF-α production in mononuclear phagocytes by suppressing TLR8 activity and this particular function of FANCC is independent of its function in protecting the genome from cross-linking agents.