Immunomax ® activates mouse and human NK cells and this activation is DC-mediated. (A) PBMC of mice injected with Immunomax® (i.v.,10 μg, □) have significantly higher rate of cytotoxicity against NK-sensitive YAC-1 target cells than PBMC from mice (■) injected with PBS. Consolidated data (mean ± SE) of two independent experiments are presented (*P<0.05, **P<0.01). (B) Immunomax® significantly increased the frequency of activated NK cells in purified NK cell/S-DC co-culture but not in purified NK cell culture (*P<0.05). (C) Immunomax® induced proliferation of mouse DX5+ NK cells via the activation of BM-DC. BM-DC pre-activated with Immunomax® (10 μg/ml, 18 hrs, □) were more effective in activation and proliferation of NK cells than control BM-DC without Immunomax® pre-incubation (■). Consolidated data (mean ± SE) of three independent experiments are presented (*p<0.05). (D) A percent of activated and proliferating NK cells in CD4-, CD8-,CD19-,DX5+ subset of mouse splenocytes. (E) Activation with Immunomax® significantly increased the ability of mouse purified NK/BM-DC co-culture to inhibit the growth of 4T1-GFP tumor cells (**P<0.01). (F) Human PBMC stimulated in vitro with Immunomax® (10 μg/ml, □) killed K562 cell line more effectively than control PBMC (■) (*p<0.05). (G) Immunomax® activated NK cells in human whole blood (gray square), but did not activate purified fraction of NK cells from the same blood (■). Consolidated data (mean ± SD) of three independent experiments are represented (**P<0.01).