title: Do bursa-derived T cells exist?
abstract: In order to study the bursal origin of T cells, 18-d chromosomally-marked bursa cells were transplanted into 18-d chick embryos treated with cyclophosphamide (CY). Transfer of bursa cells restored not only the humoral immune functions but also the mitogenic responses of peripheral blood lymphocytes against phytohaemagglutinin and concanavalin A (Con A). Transplanted bursa cells proliferated primarily in the recipients' bursa. Only 8 out of 209 Con A responsive spleen cells were of donor origin, but no donor-derived cells were observed in the thymus. These findings suggest that cells in the 18-d embryonic bursa are already committed to the B cell lineage, and are not capable of migrating into thymus and of developing into mature T cells.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens; D001402:B-Lymphocytes / Q000276:immunology / Q000637:transplantation* / Q000648:ultrastructure; D002060:Bursa of Fabricius / Q000166:cytology* / Q000196:embryology; D002465:Cell Movement; D002642:Chick Embryo; D002645:Chickens; D002875:Chromosomes; D003208:Concanavalin A / Q000494:pharmacology; D003520:Cyclophosphamide / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology / Q000648:ultrastructure; D014184:Transplantation, Homologous
chemical_list: D000941:Antigens; D010835:Phytohemagglutinins; D003208:Concanavalin A; D003520:Cyclophosphamide