Fig. 5: HMGB1 and RICTOR mRNAs epigenetically impede responses to anti-PD-L1 therapy in HCC through PD-L1+exosomes activity.

a PMBC killing assay scheme. HMGB1/RICTOR mRNA interference HCC cells (abbreviated as “KD-HMGB1 or KD-RICTOR”, respectively) were cocultured with activated PBMCs and treated with or without Atezolizumab for 48 h before apoptosis detection. b Cell apoptosis in treated HCC cells was evaluated by TUNEL assay (above). The apoptotic cell ratios were shown (below). c Exosomes isolated from cell culture supernatants in treated HCC cells were determined by flow cytometry using PE-fluorescein-conjugated anti-PD-L1 antibody (red). Isotype matched antibody (PE-fluorescein-conjugated anti-IgG antibody) was used as gating controls (black). Percentages of PD-L1+ Exo resulted from the relative fluorescence values gated by isotype controls. Exo: exosomes. **p < 0.01, ***p < 0.001