Fig. 8

PKP3 suppresses antitumor immunity by regulating PD-L1, and PKP3/PD-L1 axis inhibition enhances the efficacy of anti-PD-1 therapy. A Schematic diagram showing the grouping and treatment plan of the in vivo study: C57BL/6 mice were inoculated with 10⁶ CTRL, CTRL+PKP3-OE, sgCD274 or sgCD274 + PKP3-OE LLC cells, and the tumor volume was measured at the indicated time points. B Time-course evaluation of tumor volumes measured every 3 days. C Representative images and statistical quantitation of IF staining of PKP3, PD-L1 and CD8α in the indicated groups. Scale bars, 100 μm. D Representative images and statistical quantitation of the FACS analysis of IFN-γ⁺, TNF-α⁺, GzmB⁺ and perforin⁺ CD8⁺ TILs from the indicated xenograft tumor samples. E Schematic diagram showing the grouping and treatment plan of the in vivo study: C57BL/6 mice were inoculated with 10⁶ shControl or sh-mouse PKP3 LLC cells and received PD-1 mAb treatment or IgG2b control at the indicated time points. F Time-course evaluation of tumor volumes measured every 3 days. G Representative images and statistical quantitation of IF staining of PKP3, PD-L1 and CD8α in the indicated groups. Scale bars, 100 μm. H Representative images and statistical quantitation of the FACS analysis of IFN-γ⁺, TNF-α⁺, GzmB⁺ and perforin⁺ CD8⁺ TILs in the indicated xenograft tumor samples. I Representative images and statistical quantitation of IHC staining of PKP3 and PD-L1 in NSCLC samples from cohort I. Scale bars, 200 μm. J K–M analysis of OS of patients in cohort I. Patients were divided into group 1 (low PKP3/high TILs, n = 13), group 2 (low PKP3/low TILs or high PKP3/high TILs, n = 22) and group 3 (high PKP3/low TILs, n = 33). Data represent the mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001. P values were determined by one-way ANOVA with Tukey’s post hoc test (B, C, D, E, F, G and H) or the log-rank test (J) Correlations were determined by the Spearman correlation test (I)