NK cell cytotoxic potential and cytokine production profiles are preserved after CART transfection. (A) Isolated NK cells (500 000 cells per well) were transfected with GFP-encoding mRNA via L2000 (31 ng of mRNA per well), electroporation (31 or 10 000 ng of mRNA per well), or CARTs (31 ng of mRNA per well) and incubated for a total of 18 hours before assay of functional capacity by IL-12, -15, and -18 cytokine stimulation and K562 cytotoxicity assay. Percentage of NK cells with surface CD107a, intracellular IFN-γ, or intracellular TNFα without stimulus (B), after IL-12, -15, and -18 cytokine stimulation (C), or after K562 cytotoxicity assay at an effector/target (E/T) ratio of 1:3 (D). (E) Percentage of dead K562 cells after 10:1 E/T ratio coculture with transfected NK cells. *P < .05 via Wilcoxon matched-pairs signed rank test (B-D) or paired Student t test (E).