Fig. 4.

ALT-803 stimulation of NK cells enhances secretion of IFN-γ. a SCC2, b Cal27, and c SCC47 SCCHN tumor cells were treated with 100 μg/ml of cetuximab or control IgG for 1 h at 37 °C. Purified healthy donor CD56⁺ human NK cells incubated with cytokines (IL-12, IL-2, IL-15, or ALT-803) were co-cultured with tumor cells (cetuximab or control IgG) for 48 h and supernatants assayed for IFN-γ by ELISA. A minimum of 3 donors was tested per cell line, *P < 0.05 compared to NK + tumor cell co-culture; #P < 0.05 compared to NK + IgG + co-culture