Fig. 5

Tumor growth upon a combinatory or mono-treatment with NaHCO₃ and anti-PD-L1 in anti-PD-L1 responsive and nonresponsive tumor models. A Tumor volumes of MC38^wt (n = 8 animals per group), B MC38^{PD−L1−/−} (n = 4–5 animals per group), C IFN-γ knockout mice (neutral and acidosis, n = 7–8 animals per group). D CT26^wt (n = 7–8 animals per group), and E CT26^{PD−L1−/−} (n = 8 animals per group) tumor volumes  of mice treated with NaHCO₃ and/or anti-PD-L1 mAb. F Tumor volumes of B16-F10^wt (n = 5–8 animals per group) and (G) 4T1^wt tumors (n = 5–8 animals per group) growing in mice treated with NaHCO₃ and/or anti-PD-L1 mAb. Treatment with NaHCO₃-enriched water (200 mM, NaHCO₃) started three days prior to cancer cell inoculation; anti-PD-L1 mAb (200 µg per mouse) was administered every third day starting on day 4 (MC38^wt, CT26^wt, B16-F10^wt) or day 5 (4T1^wt) after the cancer cell inoculation. Tumors from mice with intact IFN-γ signaling that received regular drinking water developed an acidic tumor pH_e (Control). Data are presented as the means ± SEM. Statistics: Tukey’s multiple comparison test (A, C, D, and F) and Sidak’s multiple comparison test (B and E)