Interaction Between Tumor and Host During Progressive Neoplastic Growth in Histoincompatible Recipients2

Abstract

Tumor sublines were selected for progressive growth in H-2 incompatible recipients by passage through allogeneic newborn hosts or adult hosts preheated with humoral isoantibodies directed against the tumor cells. Tumors of these sublines have a reduced concentration of H-2 isoantigenic determinants compared to the strain-specific tumor of origin. The nonspecific sublines also have a markedly decreased sensitivity to cytotoxic H-2 isoantibodies in vitro. Mice carrying H-2 incompatible tumor grafts produced hemagglutinins against the tumor genotype; the fluctuations in antibody titers and tumor size were closely correlated. Experiments were performed to test the possibility that humoral antibody production facilitates tumor growth (“self-enhancement”). Injection of antiserum into mice carrying H-2 incompatible tumors increased the growth rate of the tumor. Splenectomy decreased the production of humoral isoantibodies and inhibited the growth of nonspecific tumor sublines. These findings support the hypothesis that the immune response of the hosts against H-2 incompatible neoplastic cells contributes to progressive growth by a process of self-enhancement.