Thymocyte emigration in the chicken: an over-representation of CD4+ cells over CD8+ in the periphery.
We have examined the emigration of chicken thymocytes after intrathymic fluorescein isothiocyanate (FITC) labelling in situ. In this paper we show that in young birds about 0.7% and 0.4% of thymocytes emigrate from the thymus to the blood and the spleen, respectively, per day. This suggests that, as in mammals, most thymocytes die within the thymus. At 3 weeks of age gamma delta and alpha beta T cells leave the thymus in comparable levels to their appearance in the blood. The phenotype of recent emigrants in peripheral tissues is similar to that of mature T cells. Interestingly, recent emigrants contain relatively much higher numbers of CD4+ and fewer CD8+ cells than is observed in peripheral tissues in a steady-state situation.
Katevuo
K
K
Basel Institute for Immunology, Switzerland.
Vainio
O
O
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D002645:Chickens / Q000276:immunology*; D016130:Immunophenotyping; D007700:Kinetics; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*