Fig. 5: USP5 deficiency enhances PD-L1 expression, inhibits tumor cell-intrinsic immune response and remodels anti-tumor immunity.

a Kaplan-Meier analysis of USP5 and CD4 or CD8 expression and overall survival of 90 HCC patients. b A total of 5.0 × 10⁶ WT or Usp5-KO Hepa1-6 cells were subcutaneously implanted in C57BL/6 mice pretreated with anti-IgG, anti-NK1.1, anti-CD4, and anti-CD8 antibodies (n = 6). Tumor growth was monitored at the indicated time points. ***p < 0.001 by two-way ANOVA. c IB analysis of lysates derived from dissected xenografts formed by Usp5-depleted H22 or Hepa1-6 cells. d, e IB analysis of Pd-l1 in the WT and Usp5-KO Hepa1-6 cells transfected with Flag-Ythdf1 constructs for 36 h or treated with 2.5 μM WP1130 for 24 h. f Activated T cells and tumor cells were co-cultured in 24-well plates for 4 days and surviving tumor cells were visualized by crystal violet staining. Relative fold ratios of surviving cell intensities are shown. n = 3. **p < 0.01. t-test. g Correlation between the fold changes of differentially expressed genes in Ythdf1 and Usp5 knockout Hepa1-6 cells. h The top 5 terms in GO analysis of the immune-related genes suppressed by both Usp5 and Ythdf1 knockout Hepa1-6 cells. n = 3. i GSEA and heatmap showing the differential expression of genes in Fig. 5g. n = 3. j mRNA levels of indicated genes from sgUsp5 or sgCtrl Hepa1-6 cells were analyzed using QRT-PCR. n = 3. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. t-test. k The mRNA and protein levels in Usp5 and Ythdf1 knockout Hepa1-6 cells are measured by RNA-Seq and proteomics. l, m Usp5 or Ythdf1 depletion affects tumor growth in mouse xenograft in NOD/SCID and C57BL/6 mice (n = 8). Tumor growth was monitored at the indicated time points, and tumor volume were measured at the endpoint (l). Tumor image and tumor weight are presented (m). ***p < 0.001 by two-way ANOVA. All data are presented as mean ± SEM. All IB data are representative of two independent experiments. Source data are provided as a Source Data file.