Enhanced Antibody-Dependent Lymphocyte-Mediated Cytotoxic activity in mice cured from an ascitic tumor by a single tumor aspiration

Summary Aspiration of approximately 50% of the tumor volume in the syngenic lethal C3H-L1 ascites tumor system at day 12 after intraperitoneal injection of 2×10⁷ tumor cells cured about 40% of the animals from the ascites tumor. The recovering mice showed strong immunity to a second challenge with tumor cells and transfer of spleen cells from recovering mice protected normal mice to tumor development. Complement-dependent serum-mediated cytotoxicity (CDSC) against tumor cells in vitro appeared both in non-recovering and recovering mice being most pronounced in completely cured animals. Antibody-dependent, lymphocyte-mediated cytotoxicity (ADLC) was absent in tumor-bearing and dying mice but appeared early after recovery in cured mice. No direct lymphocyte-mediated cytotoxicity (DLC) could be demonstrated either in non-recovering or in recovering mice.