Development of cytoplasmic CD3+/T cell receptor-negative cells in the peripheral lymphoid tissues of chickens.
In a study of T cell ontogeny using monoclonal antibodies specific for chicken T cell receptors (TcR) and associated cell surface molecules, we found a subset of lymphocytes that express cytoplasmic CD3 epitopes in the absence of cell surface CD3/TcR complexes. Approximately half of these cells, which were present in the spleen, bursa and intestine of young chick embryos, expressed surface CD8. None expressed CD4, TcR 1 (gamma/delta), TcR 2 (alpha/beta) or TcR 3 (a third CD3-associated heterodimer in the chicken). These cytoplasmic CD3+CD8 +/- cells, tentatively named TcR 0 cells to denote their lack of surface TcR, appeared first in the spleen of 8-day embryos, 4 days before TcR expression begins in the thymus, and reached a peak frequency of approximately 10% of the splenic cell in 14-day embryos. The TcR 0 cells were also present in adult birds, where they comprised only about 1% of the CD3+ spleen cells and approximately 40% of the lymphocytes in the intestinal epithelium. We conclude that the avian TcR 0 cells represent a thymus-independent lineage of lymphocytes which, like natural killer cells in mammals, may play an important role in body defense.
Department of Pathology, University of Alabama, Birmingham.
R P
RP
Bucy
C L
CL
Chen
M D
MD
Cooper
D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D002060:Bursa of Fabricius / Q000196:embryology; D017252:CD3 Complex; D002642:Chick Embryo / Q000166:cytology / Q000276:immunology*; D003593:Cytoplasm / Q000276:immunology; D000939:Epitopes / Q000032:analysis; D007422:Intestines / Q000196:embryology; D008221:Lymphoid Tissue / Q000166:cytology / Q000196:embryology* / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D013154:Spleen / Q000196:embryology; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000196:embryology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D000939:Epitopes; D011948:Receptors, Antigen, T-Cell