Figure 1.
Combination radiation and anti-PD-1 therapy induces an abscopal effect in contralateral flank tumors. A. 1.5 × 105 B16-F10 tumor cells were injected in to each flank of wildtype C57BL/6 mice. Nine days later, mice received 150 µg anti-PD-1 antibody or IgG via intraperitoneal injection. After five days, indicated mice received 8 Gy in 4 fractions to one flank tumor. Growth of the irradiated (left) and non-irradiated contralateral tumor (right) was followed for 20 days. B. At the conclusion of the experiment, tumor tissues were harvested and digested to a single cell suspension with collagenase/hyaluronidase. T cell phenotype and frequency was determined using staining for readout by flow cytometry. Indicated study is representative of the independent experiments. *P < 0.05 for the indicated comparisons at day 20 in A. and between anti-PD-1 and anti-PD-1 + head irradiation groups in B.