title: Distribution of T and B lymphocytes in jejunal and ileocaecal Peyer's patches of lambs.
abstract: Jejunal (JPPs) and ileocaecal (IPP) Peyer's patches in lambs were studied by employing the indirect and the avidin-biotin-peroxidase methods, using antibodies to sheep IgM and thymocytes. Thymocyte sera absorbed with IPP germinal centre cells showed specificity for T cells in the thymus, lymph nodes and Peyer's patches. Whereas JPPs had large interfollicular T cell areas, IPP mainly contained B cells, although small triangular T cell areas were found at the apex of the follicles. Some T cells were also found in the dome and corona region of JPPs and IPP. While germinal centres of JPPs had about 40 per cent of IgM-positive cells, IPP germinal centres contained about 80 per cent of such cells. Negative or weak IgM-positive cells were seen in the peripheral zone of IPP germinal centres, contrasting with surface IgM-positive cells in the central zone, and indicating a centripetal migration of maturing lymphocytes.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002432:Cecum / Q000166:cytology / Q000276:immunology*; D005260:Female; D007082:Ileum / Q000166:cytology / Q000276:immunology*; D007075:Immunoglobulin M / Q000032:analysis; D007583:Jejunum / Q000166:cytology / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology; D008297:Male; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology*; D012756:Sheep; D013601:T-Lymphocytes / Q000166:cytology*; D013950:Thymus Gland / Q000276:immunology
chemical_list: D007075:Immunoglobulin M