Fig. 5.

F. nucleatum enhanced the therapeutic effect of PD-L1 blockade by activating STING signaling. a–d The indicated proteins were detected by Western blotting. Actin was used as a loading control. a DLD1 cells were treated with Fn (1:1000) for different time course. b DLD1 cells were pre-treated with H151 for 2 h, and then treated with Fn (1:1000) for 12 h. c CT26.WT cells were treated with Fn (1:1000) for different time course. d CT26.WT cells were pre-treated with C176 for 2 h, and then treated with Fn (1:1000) for different time course. e–h CT26.WT cells were subcutaneously injected into BALB/c mice (n = 7 for each group). Tumor-bearing mice were pre-treated with C176 or vehicle, then intratumorally injected with F. nucleatum or PBS and intraperitoneally injected treated with an anti-PD-L1 mAb or an isotype control mAb every three days until the end of the experiment. Tumor volumes were measured. e An image of tumors collected at the end of the experiment is shown. f, g Tumor volumes and relative tumor volumes at various time points are shown. One-way ANOVA and Bonferroni’s multiple comparison test. h Flow cytometry was used to detect the proportion of IFN-γ⁺ cells in CD8⁺ TILs from mice. One-way ANOVA and Bonferroni’s multiple comparison test. *P < 0.05; **P < 0.01. Fn, F. nucleatum