CD1d blockade enhances systemic IFN-γ response induced by RT + anti-CTLA-4 blockade. WT or iNKT−/− mice were treated with local tumor radiotherapy in two fractions of 12 Gy given on days 13 and 14 post-tumor inoculation. Mice received anti-CTLA-4 mAb on days 15, 18 and 21. Some mice additionally received anti-CD1d mAb or isotype mAb i.p. on days 3, 7 and 11 post tumor inoculation. Spleen were harvested at day 22 and concentration of (A) IFN-γ, (B) IL-10 and (C) IL-4 were measured in supernatants of PMA + ionomycin stimulated cells. Bars indicate the mean ± SD of 4 mice/group. **
p < 0.005.