Fig. 6

PPT1 inhibitor DC661-induced immunogenic cell death promoted the maturation of DCs and the activation of CD8⁺ T cells. A Immunofluorescent imaging of CRT expression on the cell surface of Hep 1-6 cells treated with DC661 (3 µM, 6 h). Nuclei are stained with Hoechst 33,258. Scale bars, 10 μm. B Immunofluorescent imaging of HMGB-1 release by Hep 1-6 cells treated with DC661 (3 µM, 6 h). Nuclei are stained with Hoechst 33,258. Scale bars, 10 μm. C ELISA detection of HMGB1 release into cell culture medium. Cells were incubated with DC661 at 3 µM for 6 h. Data represent mean ± SD; ***P < 0.001. D ELISA detection of ATP release into the cell culture medium. Cells were incubated with DC661 at 3 µM for 6 h. Data represent mean ± SD; ***P < 0.001. E, F Flow cytometric analysis (left) and quantification (right) of mature DC cells (CD11c⁺CD80⁺CD86⁺) from the spleens of DC661- or vehicle-treated Hep 1-6 tumor-bearing mice. Data represent mean ± SD; ***P < 0.001. G–I The expression level of PPT1 was associated with the immune infiltration in the HCC tumor microenvironment. Scatter plots (G) and correlation diagrams (H, I) showing the difference of CD4⁺ T cells and macrophages infiltration level between PPT1-high and -low groups in TCGA-LIHC. **P < 0.01; ***P < 0.001