Figure 4.

VPA Augments HSV^GM-CSF Innate Anti-tumor Immunity

(A) Expression of NK ligands (MICA/B and ULBP2/5/6) on the surface of melanoma cells was determined by flow cytometry. Cells were treated with VPA at the indicated doses for 48 h. Mean fluorescence intensity is shown + SEM (n = 3). (B) Healthy donor PBMCs (untreated [0 PFUs] or activated with HSV^GM-CSF [0.001 or 0.01 PFUs] overnight) were co-cultured with melanoma cells with or without VPA for 5 h, and the percentage of target cell death was determined by flow cytometry. The graph shows the mean + SEM for at least four independent experiments. Statistical significance is denoted by *p < 0.05, **p < 0.01, and p*** < 0.005.