CD1d blockade improves response of WT mice to treatment with radiotherapy and anti-CTLA-4. (A) WT 4T1 tumor-bearing mice (N = 8 mice/group) 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 on days 3, 7 and 11 post tumor inoculation. (B) Tumor growth is shown for each group until the last day when all mice were alive, day 28 for control and anti-CD1d treated groups, and day 35 for RT + anti-CTLA-4-treated groups. Fractions indicate the number of mice showing complete tumor regression over the total in each group. (C) Surviving tumor-free mice were followed until day 150. Data shown are from one of 2 independent experiments performed with similar results. *
p < 0.05, **
p < 0.005.