Effects of interleukin-2, OK-432 and interferon-gamma on in vitro induction of nonspecific killer cells by concanavalin A in mice.

Human interleukin-2 (IL-2), OK-432 and mouse interferon-gamma (IFN-gamma) were evaluated for their beneficial effects on in vitro induction of nonspecific killer cells by concanavalin A (Con A). Nonspecific killer cells could be induced by culturing C57BL/6 spleen cells for 4 days with Con A. Con A activated killer cells showed direct cell-mediated cytotoxicity (DCMC) and lectin-dependent cell-mediated cytotoxicity (LDCC) against natural killer (NK) sensitive YAC-1 cells, and LDCC against NK-resistant EL-4 cells in a 4 hr-51Cr release assay. Higher DCMC and LDCC reactivity against YAC-1 cells, and higher LDCC reactivity against EL-4 cells were obtained with spleen cells cultured with Con A plus IL-2, or Con A plus OK-432 than with those cultured with Con A alone. No beneficial effect of IFN-gamma and no additive effects of IL-2 plus OK-432, or IL-2 plus IFN-gamma were observed in the induction of nonspecific killer cells by Con A.