Differentiation of B lymphocytes in sheep. I. Phenotypic analysis of ileal Peyer's patch cells and the demonstration of a precursor population for sIg+ cells in the ileal Peyer's patches.
The ileal Peyer's patches (IPP) of sheep may be a primary lymphoid organ for b cells since they have a number of important features in common with the bursa of Fabricius of chickens. We have examined the surface phenotype of IPP cells. Approximately 90% to 95% of IPP cells are 'low sIgM+'; that is, they have surface IgM, but in much smaller amounts than peripheral B cells, which are 'high sIgM+'. IPP cells with sIgG or sIgA are very rare. Upon exposure to a tumour promotor, phorbol myristate acetate (PMA), in vitro, low sIgM+ cells differentiated into high sIgM+ cells. The amount of Ia-like antigens on the surface also increased after PMA treatment. Approximately 5% of IPP cells bore no identifiable markers. However, these cells could also be induced into high sIgM+ cells upon exposure to PMA; this may indicate the presence of precursors of sIgM+ cells within the IPP. While PNA (peanut agglutinin) binds strongly to the vast majority of IPP cells, it binds very little, if at all, to B cells obtained from the periphery, unless they have been treated with neuraminidase; this suggests that cells in the B lineage retain their PNA receptors, but that these become masked by sialic acid on mature B cells.
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation / Q000187:drug effects; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007082:Ileum / Q000276:immunology*; D007075:Immunoglobulin M / Q000032:analysis; D008196:Lymph / Q000276:immunology; D008297:Male; D010581:Peyer's Patches / Q000276:immunology*; D011947:Receptors, Antigen, B-Cell / Q000032:analysis*; D012756:Sheep; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell; D013755:Tetradecanoylphorbol Acetate