Ionomycin treated NK cells were unable to secrete IFN-γ as efficiently as control cells, and they do not secrete immunosuppressive cytokines.

<p>(<b>A</b>) IFN-<b>γ</b> production by NK cells was analyzed by flow cytometry after a 6 hours accumulation in the presence of 2.5 μM monensin. Cells were unstimulated, stimulated with 50 U/mL IL-2. or 10ng/mL IL-12 plus 10 ng/mL IL-18 during the resting day, and left alone or cocultured with K562 target cells during 6 hours. PMA/ionomycin stimulation during 4 hours of NK cells was also used to measure their potential ability to produce IFN-<b>γ</b> (<i>n = 6</i>). Two tailed paired Student's T test analysis. (<b>B</b>) Culture of autologous NK cells alone (separate) or in co-culture with DMSO control or ionomycin treated NK cells had no effect on the ability of these NK cells to respond to targets (<i>n = 4</i>). Paired one way ANOVA analysis and Tukey's multiple comparison test. The data show mean ± SEM. **<i>p</i> < 0.01, ***<i>p</i> < 0.001, <i>n</i>.<i>s</i>.: non-significant.