NK cells induce IL-10–producing Tr1-like cells in GKO mice. GKO mice depleted of NK cells and repleted with autologous or WT NK were immunized for EAU. (A) On day 11, CD4⁺ T cells were isolated from draining LNs and pulsed with PMA/ionomycin. Expression of Tbet and IL-10 in CD4⁺ T cells was studied by intracellular staining. (left) Representative staining; (right) mean values of three combined experiments; (B) Expression of Tr1-related genes: Il10, Il21, Tbx21, cMaf, and Ahr of cells in A by real-time PCR. (C) Expression of Tbet and Foxp3 in CD4⁺ T cells was quantitated by intracellular staining. Data in B and C are from three independent experiments. **, P < 0.01 by Mann-Whitney U test.