An area of T cell localization in the cloacal bursa of White Leghorn chickens.
Within the cloacal bursa (bursa of Fabricius), there is a diffusely infiltrated area (DIA) of lymphoid cells just dorsal to the bursal duct opening. Because this region displayed certain histologic characteristics of thymus-dependent areas found in mammals, such as high endothelial venules, heavy reticular fiber components, and epithelium infiltrated with lymphocytes, experiments were conducted to determine whether thymus-derived cells (T cells) were present. Two independent methods substantiated the presence of T cells in the DIA. After the acid alpha-naphthyl acetate staining technique, the characteristic T cell focal esterase activity could be demonstrated in significant numbers of cells found in the DIA. Also autologous radioactively labeled thymocytes could be identified in the DIA by autoradiography a few hours after IV injection. This establishment of a definite T cell area within the bursa gives additional credence to the contention that the bursa functions as a secondary lymphatic organ.
D000818:Animals; D001345:Autoradiography; D002060:Bursa of Fabricius / Q000166:cytology* / Q000201:enzymology; D002645:Chickens / Q000033:anatomy & histology*; D006651:Histocytochemistry; D009283:Naphthol AS D Esterase / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000201:enzymology / Q000637:transplantation; D014182:Transplantation, Autologous
D009283:Naphthol AS D Esterase