Immunocompetent cells of the chicken. I. Specific surface antigenic markers on bursa and thymus cells.

Specific antisera to chicken thymus and to bursa of Fabricius were obtained in rabbits. After appropriate absorption and dilution all four anti-thymus sera, in the presence of guinea pig C', killed >90% of thymus and <==12% of bursa cells. They were cytotoxic for approximately 50% of spleen cells and did not affect antibody-forming cells. The surface antigen detected by these antisera was named chicken T-lymphocyte antigen (CTLA). Two of four anti-bursa sera, under similar conditions, killed >90% of bursa cells and <==10% of thymus cells. These antisera were cytotoxc for a large percentage of antibody-forming cells and killed approximately 30% of spleen cells The other two anti-bursa sera were somewhat less potent but showed similar specificity. The surface antigen detected by these antisera was named chicken bursa-derived lymphocyte antigen (CBuLA). Rabbit antisera to chicken immunoglobulin were cytotoxic for bursa but not for thymus cells and killed a similar percentage of spleen cells as did anti-bursa sera. They were also cytotoxic for antibody-forming cells.