Reduced priming capability of WAS KO DCs. (A) CD4⁺ T cells were isolated from OVA/CFA-immunized C57BL/6 mice and in vitro proliferation was determined after stimulation with OVA and DCs of either C57BL/6 or WAS KO mice. Similar T-cell stimulatory capacity was observed between the strains for the higher range of OVA, but with lower OVA concentrations, WAS KO DCs were less capable of inducing T-cell proliferation. (B) Ex vivo stimulation of CD4⁺ T cells, isolated from mice that were immunized with OVA-pulsed C57BL/6 DCs, showed that WAS KO DCs were less capable of inducing IFN-γ production, compared with C57BL/6 DCs. Data in panel A are representative of 2 independent experiments with DCs from 2 mice per group and pooled CD4⁺ T cells from 3 OVA/CFA-immunized C57BL/6 mice; averages plus or minus SD are shown. Data in panel B represent the averages plus or minus SEM of 6 mice per group.