title: Depletion and repopulation of lymphocytes in Peyer's patches of mice after total lymphoid irradiation.
abstract: The depletion and repopulation of lymphocytes in specific cellular domains of mouse Peyer's patches were examined following total lymphoid irradiation (TLI). BALB/c mice 5-months-old were given 17 fractionated doses of irradiation to a total of 3400 to 4250 rads over a 4-week period, and Peyer's patches were examined by immunohistochemistry at 1 to 4 days and 1 to 4 weeks after TLI. Cryostat sections were labeled with monoclonal antibodies directed against B220 (B cells), Thy-1.2 (all T cells), L3T4 (helper T cells), and Ly-2 (cytotoxic/suppressor T cells). In depleted mice, Peyer's patches were greatly reduced in size in comparison to controls, although the structural framework of follicles, domes, and interfollicular areas was still present. B cells in follicles were reduced to a small core of B220+ cells interspersed with nonlymphocytic cells. T cells were virtually eliminated from the patch except for a small population of Thy-1.2+ cells that were neither L3T4+ nor Ly-2+ in follicle domes. During early stages of repopulation at 1 to 2 weeks after TLI, follicles increased in size and were populated by helper T cells but Peyer's patches lacked discrete interfollicular T cell regions. At 3 to 4 weeks after TLI, T cell regions were found in interfollicular areas. The results indicate that morphologically distinct cellular domains are maintained in Peyer's patches after TLI which are sequentially repopulated by immigrating lymphocytes.
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000950:Antigens, Ly / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000528:radiation effects; D008208:Lymphatic System / Q000528:radiation effects*; D008214:Lymphocytes / Q000166:cytology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010581:Peyer's Patches / Q000166:cytology / Q000528:radiation effects*; D013601:T-Lymphocytes / Q000528:radiation effects; D018800:Thy-1 Antigens
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D018800:Thy-1 Antigens