Preactivation enhances human NK-cell function in spleen cells from reconstituted NSG mice and human CB. Splenocytes from reconstituted NSG mice (A-B) purified NK cells from hu-NSG mice (C-D) and human CB (E-F) were used untreated (medium) or preactivated with poly I:C [p(I:C)] or the monokines IL-12 and IL-15. These cultures were restimulated with medium alone, monokines, K562 cells, or CEM cells. Degranulation (CD107a; A,C,E) and cytokine production (IFN-γ; B,D,F) were evaluated after gating on NKp46-positive cells. Panels A and B represent composite data from 4 mice in 2 experiments, panels C and D represent composite data from 10 mice in 2 experiments, and panels E and F represent composite data from 3 experiments.