Fig. 2

A^IFN−γ induces PD-L1 expression in anti-PD-L1 mAbs therapy-responsive murine cell lines while PD-L1 expression is not significantly enhanced in those that are non-responsive. A Relative Pdl1 mRNA expression normalized to Gapdh, Aldolase and β-actin (n = 3, statistics: Tukey’s multiple comparison test), B PD-L1 mean fluorescence intensity (MFI) measured using flow cytometry (pooled data from 3 experiments, n = 8, statistics: Tukey’s multiple comparison test) and (C, D) Western blot analysis and densitometry of PD-L1 and β-actin levels (pooled data from 2 experiments, n = 4, statistics: two-tailed Mann–Whitney test) in MC38^wt cells treated with acidic media and/or IFN-γ (10 ng ml⁻¹) for 72 h. Data are presented as the means ± SEM. N = neutral media, A = acidic media, N^IFN−γ = neutral media plus IFN-γ, A^IFN−γ = acidic media plus IFN-γ. E Relative Pdl1 mRNA expression normalized to Gapdh, Aldolase and β-actin (n = 3) and (F) PD-L1 MFI measured using flow cytometry (pooled data from 2 experiments, n = 6) in murine anti-PD-L1-responsive CT26^wt cells following treatment with acidic media and/or IFN-γ (10 ng ml⁻¹) for 72 h. PD-L1 MFI of the (G) nonresponsive murine B16-F10^wt and (H) 4T1^wt cell lines (n = 3) and (I) human HCA7 colony 29 cells (n = 3) treated with acidic media and/or IFN-γ (10 ng ml⁻¹) for 72 h. Data are presented as the means ± SEM. Statistics: Tukey’s multiple comparison test. N = neutral media, A = acidic media, N^IFN−γ = neutral media plus IFN-γ, A^IFN−γ = acidic media plus IFN-γ