The role of antibody-dependent cell-mediated cytotoxicity (ADCC) in cytotoxicity mediated by antibody-armed effector cells was examined. Cytotoxicity mediated by unsensitized human peripheral blood mononuclear cells (MNC) directed against the human bladder cancer cell line, 253J, was significantly enhanced when MNC were preincubated with a rabbit anti-253J serum and then washed free of unbound antibody. Nonadherent, Fc receptor positive MNC were the effector cells and the arming antibody was IgG. Supernatants of 24-hour cultures and armed MNC exhibited antibody activity in ADCC assays, suggesting the ADCC was in part responsible for the arming phenomenon.
Absorption Animals