Figure 2

Stimulation of PD-L1 expression with IFN-γ results in activation of IFN-γ related signaling pathway components. (A,B) E0771 cells were treated with 100 ng/ml IFN-γ and Western analyses for IRF-1, STAT1, pSTAT1 (S727), PD-L1 and HSP-90 was performed indicated that IFN-γ stimulated canonical components of the IFN-γ signaling pathway. In contrast, treatment of E0771 cells with SI-2 induced PD-L1 without elevating pSTAT1 or IRF-1. (C) SI-2 induced the expression of cell stress response proteins ATF4, IRE1α, p-IRE1α and XBP1s. E0771 cells were treated for 24 hr with the indicated concentrations of SI-2. ***P < 0.005, two-tailed Student’s t-test. For each group of WB figures (A–C): all the blots were performed in the same experimental setup and processed in parallel. All gels were loaded with identical amount of protein sample. Dashed separating lines indicate that the blots were run in parallel but on separate gels. Full length blots are available in the supplementary information.