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.
|Number of pages||7|
|Journal||Scandinavian Journal of Haematology|
|Publication status||Published - 1984|
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