Abstract
Humoral antibody directed against a grafted murine lymphoma can suppress the growth of the tumor in mice of the inbred strain native to the tumor. Antibody, however, cannot suppress the tumor growth in mice given 500 R of whole-body irradiation. When the tumor-antibody inoculum is admixed with lymphocytes or macrophages obtained from peritoneal exudate, macrophages experimentally rendered nonphagocytic, or with platelets isolated from peripheral blood, the tumor growth is suppressed in irradiated mice. These results indicate that mechanisms other than phagocytosis may play an important role in antibody-mediated suppression of tumor growth in vivo.