Fig. 2.

ALT-803 stimulation of human NK cells enhances lytic activity against cetuximab-coated SCCHN cell lines. Purified human CD56⁺ NK cells were incubated overnight in medium alone or stimulated with ALT-803 (10 ng/ml). The lytic activity of NK cells against cetuximab-coated squamous cell carcinoma of the head and neck (SCCHN) cell lines a Cal27, b SCC2, c SCC47 was assessed via a standard 4-h ⁵¹Cr release assay. Each graph depicts results from one representative donor. N = 3 for Cal27 and SCC47 and n = 2 for the SCC2 cell line. d Graphical representation of cytotoxicity data for each cell line at the 50:1 E:T ratio. Means + STD lysis of three different healthy donors, *P < 0.05 compared to IgG; ^#P < 0.05 compared to cetuximab alone