Figure 5.

Obinutuzumab-experienced NK cells exhibit an enhanced IFNγ production in response to cytokines, targets or obinutuzumab re-stimulation. Primary cultured NK cells were isolated upon 90 min of co-culture (2:1) with biotinylated rituximab (RTX-exp)-, obinutuzumab (GA101-exp)-opsonized or non-opsonized Raji (Ctrl-exp) and re-plated for 12 h. (A) NK cells were stained with anti-CD16 (Leu11c) mAb for FACS analysis. Graph depicts CD16 MFI and data are presented as median with the interquartile range. **p < 0.01, ***p < 0.0005. (B) NK cells were re-stimulated (2:1) with non-opsonized targets (Raji-Ctrl), rituximab-opsonized (Raji-RTX) or obinutuzumab-opsonized (Raji-GA101) target cells in the presence of IL-12 (10 ng/mL), or (C) left untreated (none) or treated with IL-12 (10 ng/mL) or IL-2 (100 U/mL). After 18 h, supernatants were collected and assessed for IFNγ levels. Data are presented as mean ± SEM of seven independent experiments. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.0001. Compared to untreated (none), all the differences were statistically significant (p ≤ 0.001).