Enhancement of mouse natural killer cell activity after dearterialization of experimental renal tumors

Dearterialization of intrarenally transplanted syngeneic or allogeneic tumors in C57Bl/6 mice resulted in a pronounced enhancement of spontaneous cell mediated cytotoxicity of spleen lymphocytes. The augmentation was evident 48 hours after occlusion of the renal artery and persisted for at least 1 week. Dearterialization of non-tumor bearing kidneys had no effect on spontaneous cell mediated cytotoxicity. The effector cells responsible for the increased cytotoxicity were identified as natural killer cells based on their lack of adherence to nylon-wool, resistance to treatment with Thy 1.2 antibodies and complement and complete elimination by antibodies to asialo-GM1 and complement. The increase in natural killer cell activity reported here is in close parallel to that observed after embolization of human renal tumors. The present murine system may provide a valuable tool for evaluation of immunobiological effects of tumor dearterialization.