Participation of a chicken thymocyte antigen in intrathymic differentiation of T cells in vivo.
The participation of CETHB1 antigen in the intrathymic development of T cells was analysed in sublethally X-ray irradiated chickens and normal embryos which were inoculated with anti-thymocyte monoclonal antibody CETHB1. When chickens were given a sublethal X-ray irradiation on the day of hatchings immature thymocytes existed prominently in the thymus up to 3 weeks after irradiation. The inoculation of CETHB1 monoclonal antibody on days 14 and 18 after irradiation caused an increase of CD4- CD8- cells and a decrease of CD4+ CD8+ cells as compared to changes in control chickens. However, expression of T cell receptors CD3, alphabetaTCR, and gammadeltaTCR was not influenced. Inoculation of the monoclonal antibody on embryonic days 13 to 16 resulted in a decrease of CD4+ CD8- cells and an increase of CD4-CD8- and CD4+ CD8+ cells after hatching. Thus, the binding of CETHB1 monoclonal antibody to thymocytes can inhibit the differentiation of both CD4-CD8- and CD4+ CD8+ cells to CD4+ CD8+ and CD4+ CD8- or CD4-CD8+ cells, respectively. These results suggest that CETHB1 antigen participated in the growth and differentiation of thymocytes in the thymic microenvironment.
Mukamoto
M
M
Laboratory of Veterinary Immunology, Department of Veterinary Science, College of Agriculture, Osaka Prefecture University, Sakai 593, Japan.
Kodama
H
H
Baba
T
T