Response of 4T1 tumor-bearing mice to treatment with local radiotherapy and anti-CD137 mAb is improved in the absence of iNKT cells. WT or iNKT−/− mice were injected s.c. with 4T1 cells and randomly assigned to treatment groups (N = 5-6 mice/group) on day 13 when tumors became palpable. Local tumor radiotherapy (RT) in two fractions of 12 Gy was given on days 13 and 14 post-tumor inoculation and anti-CD137 mAb on days 15, 18 and 21. (A) Treatment schema. (B) Tumor growth over time. Fractions indicate the number of mice showing complete tumor regression. (C) Kaplan-Meier survival curves. (D) Tumor growth in naïve WT mice and iNKT−/− mice that rejected tumors and were challenged on day 120 with 4T1 cells. Data is representative of 2 independent experiments. *
p < 0.05.