Fig. 6.

In vivo antitumor effects of OBP-702 and anti-PD-L1 antibody against GR PAN02 tumors. A GR PAN02 cells (4 × 10⁶ cells/site) were inoculated into the flanks of C57BL/6 J mice on day − 28. Anti-PD-L1 antibody was intraperitoneally administered twice a week for four cycles (red arrows). OBP-702 (blue arrows) was injected intratumorally at 1 × 10⁸ PFUs every week for four cycles. One experiment has been performed. B Photographs of tumors in the control, anti-PD-L1 antibody-treated, OBP-702-treated, and combination treatment groups. C Tumor growth curves for non-treated control (black line), anti-PD-L1 antibody-treated (red line), OBP-702-treated (blue line), and combination treatment (green line) mice. D Representative photographs of immunohistochemical staining of CD8⁺ T cells and Gr1⁺ MDSCs in each group. Scale bars, 100 µm. The number of CD8⁺ T cells and the percent area of Gr1⁺ MDSCs were calculated from five different randomly selected fields. E Representative data of flow cytometric analysis of CD3, CD8, CD11b, and Gr1 in each group. The percentages of CD3⁺CD8⁺ T cells and CD11b⁺Gr1⁺ MDSCs among CD45⁺ cells are shown. Data are expressed as mean ± SD (n = 7 in each group; *P < 0.05; **P < 0.01; ***P < 0.001)