B6^dom1 is a dominant epitope recognized by C3H.SW-derived CTLs on C57BL/6, LP, and D1.LP, but not on 129 cells. (A) B6^dom1 is dominant on C57BL/6, LP, and D1.LP cells. C3H.SW mice were primed IP and their splenocytes were restimulated in MLC with cells from C57BL/6, LP, or D1.LP mice. Effectors were tested at various E:T ratios on C3H.SW Con A blasts that had been incubated with graded concentrations of B6^dom1 peptide (⧫), control YSNENMDAM peptide (□), or culture medium alone (◂). (B) LP-derived anti-C57BL/6 CTLs do not kill T2D^b targets coated with B6^dom1 peptide. E:T ratio was 50:1 (closed bar) or 25:1 (open bar). (C) B6^dom1-specific CTLs (SW10/B cell line) kill 129 Con A blasts. (D) C3H.SW-derived anti-129 CTLs do not kill C3H.SW Con A blast targets coated with optimal concentration of B6^dom1 peptide (AAPDNRETF; 10⁻¹⁰ mol/L).