Figure 2.

ML NK cells control CRC cells growing in spheroids more efficiently than cNK cells. spheroids generated from GFP+ HCT116 (a–c) and HT29 (d–f) cells were incubated with cNK or ML NK cells at different E:T ratios. (a, d) Representative images at baseline and at 24 h of spheroids (green) and labeled NK cells. (b, e) quantitation of GFP+ area of spheroid images. Untreated spheroids were used as control. (c, f) annexin V/7-AAD flow cytometry-based killing assay. Spheroids were co-cultured with cNK or ML NK cells at indicated E:T ratio for 4 hours and then dissociated for flow cytometric analysis. Percent of specific killing was calculated as the decrement in annexin V/7-AAD negative viable tumor cells compared to tumor cells alone. Two-way ANOVA with Tukey posttest for imaging, two-way repeated measures ANOVA for flow-based killing assay. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.