H-2K^b mutations limit the CTL response to SV40 TASA

The cytotoxic T lymphocyte (CTL) responses directed towards SV40 tumor-associated specific antigen (TASA) in nine strains of spontaneously arising K^b mutant mice were analyzed. All nine mutants generated normal levels of H-2D^b-restricted response, but the K-end-restricted CTL response varied. B6.C-H-2^bm1 (bm1) did not produce K-end-restricted SV40 TASA-specific CTL upon immunization, and SV40-transformed bm1 cells were not lysed by intra-H-2 recombinant K^b [B10.A(5R)] CTL. Nonreciprocal cross-reactive lysis was seen between B6-H-2^bm8 (bm8) and B10.A(5R). Strain B6-H-2^bm8 mice produce highly specific K^bm8-restricted CTL that lyse SV40-transformed bm8 cells (Kbm8SV) but not B10.A(5R) target cells (K5RSV), although Kbm8SV targets can be partially lysed by B10.A(5R) CTL. The other seven K^b mutants cross-react with B10.A(5R). These experiments definitively show that genes mapping to the K and/or D region directly control the H-2-restricted CTL response to SV40 TASA.