The effects of activin-A and TGF-β on NK-cell IFN-γ production, gene regulation, and viability. Purified NK cells were cultured at 105 (A,E) or 106 (B-D) in 96- or 24-well plates, respectively, in media supplemented with IL-2 (20 U/mL) and IL-12 (10 ng/mL) in the absence or presence of increasing concentrations of activin-A or TGF-β. (A) NK-cell production of IFN-γ by ELISA after 24 hours. (B-D) Detection of T-bet, IFN-γ, Perforin, Granzyme A and B, IL-12RBI and IL-12RBII mRNA expression by qRT-PCR ex vivo or after 16 hours of stimulation in the absence of presence of activin-A or TGF-β (each 100 ng/mL). (E) Detection of cell viability by PI and apoptosis by poly-caspase, caspase 3/7, and caspase 8 expression using flow cytometry. Data represent the mean plus or minus 1 SD of 3 separate donors. *P < .01 and **P < .05 versus no addition of activin-A or TGF-β or versus ex vivo– or cytokine-stimulated levels.
