Figure 5.

Impact of the depletion of extracellular Ca²⁺ on NK cell cytotoxic activity. The cytotoxic activity of NK cells was assessed in the presence of EDTA by a flow cytometry-based assay using purified NK cells from healthy donors as effector cells and K562 cells as target cells at the indicated effector: target (NK: K562) ratios. EDTA was added to conditioned medium (ALG-CM) (grey hatched bars) or CaCl₂ solution at 3mM (light grey hatched bars). NK cells were incubated with CFSE-labeled K562 for 18h. Results are the mean of the percentage of 7-AAD positive K562 ± SEM of 6 independent experiments. Statistics compared to each media without the addition of EDTA (filled bars) using Wilcoxon paired test *p<0.05.