Cytolytic thymus derived lymphocytes specific for allogeneic stimulator cells crossreact with chemically modified syngeneic cells

Mouse spleen cells cocultured with irradiated allogeneic stimulator cells develop cytolytic effector cells capable of lysing ⁵¹Cr-labeled syngeneic trinitrophenyl-derivatized tumor or spleen targets and to a lesser degree unconjugated tumor cells in addition to the allogeneic stimulator cells. Lysis of trinitrophenyl-syngeneic targets was inhibited completely by cold trinitrophenyl-syngeneic tumor or spleen targets as well as by cells bearing the allogeneic stimulator H-2 haplotype demonstrating the immunological specificity of the interaction. Allogeneic H-2 specificities may, therefore, be considered variants of modified autologous H-2 specificities against which cytolytic thymus-derived clones potentially exist that are capable of exerting immunological surveillance.