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-2Kbaand H-2Ddaalloantigens are sensitive to both anti-Ly-1 and anti-Ly-2 serum plus complement. Reconstitution analysis 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 responsive T cells.