T lymphocyte response to H-2 mutants: Cytotoxic effectors are Ly-1 ⁺2 ⁺

The lymphocyte differentiation (Ly) antigen phenotype of cytotoxic effector T cells specific for H-2 mutant alloantigens was determined. Cytotoxic effectors generated in primary mixed lymphocyte culture and specific for H-2K(ba) and H-2D(da) alloantigens are sensitive to both anti-Ly-1 and anti-Ly-2 serum plus complement. Reconstitution analysis is demonstrated that the mutant-specific T cells were Ly-1 ⁺2 ⁺. These observations and those previously reported, which indicated that H-2K/D mutant-specific T cells proliferating in mixed lymphocyte culture were Ly-1 ⁺2 ⁺, demonstrated that Ly-1 ⁺2 ⁺ T cells are immunocompetent. Furthermore, the nature of the stimulating H-2 complex alloantigen determines the Ly phenotype of response T cells.