Figure 5.

PD-1 Blockade Enhances IAV-Mediated Oncolysis of B16-F10 Melanoma Lung Metastases

(A) Immune checkpoint profile of B16-F10 cells. In vitro-cultivated B16-F10 cells were subjected to flow cytometry analysis for different IC molecules, including CTLA-4 ligands CD80 and CD86, PD-1 ligands PD-L1 and PD-L2, as well as B7-H3 and B7-H4. Shown are FACS histograms representative of two independent experiments. (B) Time schedule of IAV infection (red arrow), anti-PD-L1 mAb injections, tumor score, and BALF analysis (blue arrows) of C57BL/6 mice after i.v. injection of syngeneic B16F10 melanoma cells (upper black arrow). (C) The number of surface metastases and their progressive growth were calculated on day 12 p.i. as described in the legend of Figure 3. The amount of tumor tissue in non-infected mice treated with the isotype antibody was assigned a value of 1 (right image, black column with open symbols). Values of individual animals and mean values (columns) per group are shown. ∗p < 0.05 (one-way ANOVA followed by Dunnett’s multiple comparison test). (D) Levels of pro-inflammatory cytokines in BALFs were measured on day 12 p.i. Values of individual animals and mean values (columns) per group are shown.