Fig. 3

IFN-γ correlated with the upregulation of PD-L1 in glioma microenvironment. a The gating strategies of flow cytometric analysis and the analysis of PD-L1 expression on the glioma-infiltrated immune cells. Tumor-infiltrated cells were isolated from GL261 model (day 20). b The statistical summary for PD-L1 expression on the major glioma-infiltrated immune cells, n = 6. c Primary microglia, BMDM, or GL261 cell line treated with IFN-γ (20 ng/ml) for 24 h, and the PD-L1 expression was analyzed by flow cytometry. d The statistical summary for PD-L1 expression of the cells, n = 3. e Microglia were treated with or without GCM (20%, vol/vol) for 24 h. Then, microglia were washed with PBS after stimulation. OT II mice-derived CD4⁺ T cells were isolated and stained with CFSE dye. Microglia and CD4⁺ T cells were co-cultured for 4 days supplied with or without OVA_323–339 peptides (0.1 μM). Flow cytometry analysis of the co-cultured microglia for PD-L1 level. f Flow cytometric analysis of tumor-infiltrating IFN-γ⁺ cells. Tumor-infiltrated cells were isolated from the GL261 model (day 20). Right panel, the summary of IFN-γ⁺ cell population. Unpaired Student’s t test was performed in b and d. **p < 0.01. All values are shown as mean ± SEM