NK cells are the major source of innate IFN-γ in EAU. (A) DLN of WT mice immunized for EAU were harvested at the specified time and restimulated with low (10 ng/1 µg) or high dose (200 ng/5 µg) PMA/Ionomycin. Intracellular IFN-γ was analyzed in cells expressing NK1.1, CD3, CD4, CD8, and γδ TCR. Data are combined from two experiments with five mice at each time point. (B) WT mice were immunized for EAU and some animals received anti-NK1.1 or anti-CD8 to deplete NK or CD8 T cells. Disease was monitored at the indicated time points by fundus examination (n = 4–6 mice per group). Data are combined from two experiments totaling at least 15 mice per point. *, P < 0.05; linear regression in A and B.