Antibody-mediated redirected cytolysis against murine melanoma cells in vivo.

Cytotoxic T lymphocytes can lyse Fc receptor-bearing target cells in vitro in the presence of anti-CD3 antibodies. This "redirected" lysis is not restricted by major histocompatibility antigens nor does it require nominal antigen recognition by the CTL. The efficacy of redirected lysis in vivo was assessed by comparing the survival of mice inoculated with a melanoma cell line transfected with the gene for mouse Fc receptor versus the untransfected melanoma when inoculated with syngeneic mouse CTL and anti-CD3 antibody. Survival was significantly higher in the animals given injections of Fc receptor melanoma, CTL, and anti-CD3 monoclonal antibody. Delayed injection or i.v. injection of CTL failed to significantly improve survival. Redirected lysis does not preclude the establishment of tumor immunity, since animals that rejected the tumor as a result of redirected lysis exhibited an increased resistance to reinoculation with tumor cells.