Analysis of thymus-leukemia (TL) antigens with monoclonal antibodies

Lysates of radioiodinated thymocytes have been sequentially immunoprecipitated with monoclonal antibodies specific for thymus-leukemia (TL) antigens. The TL antigenic specificities defined by the monoclonal antibodies appear not to correspond precisely to specificities previously defined with conventional alloantisera. Nonetheless, each of two monoclonal antibodies specific for a single TL determinant was found to deplete lysates of B6.Tlaa thymocytes of all molecules precipitable by an alloantiserum specific for the conventionally defined determinants TL.1,2,3,5, and 6. These results suggest that on B6.Tlaa thymocytes, all the conventional TL antigenic specificities (TL. 1,2,3,5,6) as well as the specificities defined by the monoclonal anti-TL antibodies (TL.m2,m3) are carried by a single molecular species.