Cell‐mediated anti‐tumor response in the RL♂61 system II. Control of the T killer cells by an H‐2‐linked Ir gene interfering with non‐H‐2 factors

Abstract

The generation of cytolytic T lymphocytes (CTL) during the immune response directed against the syngeneic X‐ray‐induced BALB/c RL♂ 1 leukemia has been described previously: T killer cells react with a tumor antigen of RL♂ 1 cells, and the H‐2D^d molecules of the target cells play some role in the interaction. The study of anti‐RL♂ 1 responses of [(C57BL/6 × BALB/c) × BALB/c] mice shows that the major histocompatibility complex controls the anti‐RL♂ 1 CTL reaction at a second level, through an Ir gene, with dominant responsiveness, probably mapping to the right of I‐B and controlling the high or low‐CTL responder phenotype. Another non‐ H‐Associated gene interferes with the H‐2‐linked Ir gene, a responder allele at the non‐H‐2 locus, being necessary for the expression of the high‐responder phenotype at the Ir gene locus.