Combined anti-OX40/IL-2c therapy boosts anti-tumor immunity through a T cell-dependent mechanism.

<p><b>A, B</b>) Wild-type mice received 1×10⁶ MCA-205 sarcoma tumor cells (n = 8/group). Tumor-bearing mice were treated with anti-OX40 or rat IgG Ab (days 10, 14; i.p.) along with IL-2 cytokine/mAb complexes (days 10–13; i.p.) and the extent of <b>A</b>) tumor growth and <b>B</b>) survival of tumor-bearing mice were assessed. Data are representative of one out of 2 independent experiments. <b>C</b>) MCA-205 tumor-bearing mice (as in (<b>A</b>)) received no treatment (n = 9), anti-CD4 (n = 6), anti-CD8 (n = 6), or anti-CD4+anti-CD8 (n = 3) (200 mcg/dose; i.p.) 9, 17, and 24 days post-tumor implantation. Mice were then treated with anti-OX40 (days 10, 14) and IL-2c (days 10–13) and the extent of survival of tumor-bearing mice was assessed.