F1 resistance to AKR lymphoma cells in vivo and in vitro.

AKR X DBA/2 (AKD2F1) mice resist growth of injected spontaneous AKR lymphoma cells. In vitro, normal F1 responder cells generate Thy-1 positive effector cells specifically cytotoxic for the sensitizing antigens of parental AKR normal or lymphoma cells. The possibility is considered that the homozygous normal and neoplastic AKR cells express antigenic determinants, analogous to hemopoietic histocompatibility (Hh) antigens, which are recognized by the F1 hybrid, resulting in in vivo tumor resistance and in vitro cell-mediated cytotoxicity.