SEPARATE CLONES OF CYTOTOXIC T LYMPHOCYTES ARE GENERATED AGAINST PRIVATE AND PUBLIC H-2 ANTIGENS

By cytolysis and monolayer absorption tests, the kinetics of the generation of CBA/H cytotoxic lymphocytes (Tc) in response to stimulation by H-2b antigens have been analyzed in vitro. The Tc population which reacts with public antigens of H-2b and H-2d strains shows peak activity in culture at 4 to 5 days, then rapidly decreases. The population with cytotoxic activity against the private antigens of H-2b cells peaks later and persists longer. The antipublic cytolytic activity was shown to be specific and not attributable to antibody-dependent cell-mediated cytotoxicity (ADCMC), but was attributable to Ly1-, 2+ effector cells. By suitable conditions of absorption on C57BL/10 monolayers, the precursors of the antiprivate clone could be selectively removed without impairing the antipublic H-2d response. These and previous results present an argument that the cross-reactivity which Tc display on different H-2 haplotypes is attributable to clones directed against shared determinants and is not attributable to low affinity binding of Tc activated by private H-2 antigens.