Flt3L treatment enhances human NK cell function in spleen cells from reconstituted BRGSF mice. (A) Human NK cells were magnetic-activated cell sorting–enriched from spleens of BRGSF Flt3L treated or not and were stimulated ex vivo with the monokines IL-12, IL-15, and IL-18. Representative flow cytometry immunophenotypic analysis of degranulation (CD107a) and cytokine production (IFN-γ) in NKp46⁺ NK cells is shown. (B) Quantification of IFN-γ–producing and CD107a-expressing NK cells from Flt3L-treated or control BRGSF mice. (C) In vivo functionality of NK cells in BRGSF mice was evaluated by quantifying IFN-γ production and degranulation after in vivo poly(I:C) stimulation. (B,C) Composite data of 4 mice per condition in 2 experiments. Each dot represents 1 mouse. Numbers in plots represent frequencies within gates.