FIGURE 4.

LAK cells, cultured in the presence of blocking anti-2B4, anti-CD48, or anti-CD2 mAbs, produced less IFN-γ upon K562 target exposure. Human primary NK cells, cultured with 300 units/ml of IL-2 for 14 days in the presence (A) or absence (B) of 5 μg/ml of isotype control or anti-2B4, anti-CD48, or anti-CD2 mAbs, were incubated with K562 cells at an E:T ratio of 2:1 for 18 h. In B, mIgG isotype control, anti-2B4, anti-CD48, or anti-CD2 mAbs were added during the 18-h assay. Secretion of IFN-γ into the supernatant was assessed by ELISA. The data are representatives of a minimum 3 of independent experiments. ***, p < 0.001, as determined by ANOVA combined with a Tukey post hoc test. Error bars represent S.D.