Phenotype of the terminal transferase-positive cells in human foetal liver and bone-marrow: analysis with monoclonal antibodies.
Liver and bone-marrow of 20 human foetuses between 15th and 20th week of gestational age were examined. Mononuclear cells were labelled with murine monoclonal antibodies to reveal surface antigens and with a rabbit antiserum to TdT for the detection of the nuclear enzyme, using a double colour indirect immunofluorescence technique. The results have revealed that TdT+ cells express the phenotype of B cell precursors HLA-DR+, CALLA+, FMC8+, LEU-1-, LEU-5-, LEU-9-. It suggests that foetal liver and bone-marrow have an active function in B-lymphopoiesis in humans. The involvement of TdT in the process of B-cell immunological acquisition is uncertain because only humans and Xenopus embryos, among the species examined, express TdT outside the thymus during ontogenesis.
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000032:analysis; D001853:Bone Marrow / Q000196:embryology* / Q000201:enzymology; D004253:DNA Nucleotidylexotransferase / Q000032:analysis*; D004254:DNA Nucleotidyltransferases / Q000032:analysis*; D005260:Female; D005455:Fluorescent Antibody Technique; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D008099:Liver / Q000196:embryology* / Q000201:enzymology; D010641:Phenotype; D011247:Pregnancy
D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D004254:DNA Nucleotidyltransferases; D004253:DNA Nucleotidylexotransferase