Fig 1: RRBP1 inhibition promotes antitumor immunity via the CXCL10-CXCR3 axis in BC. (A) ScRNA-seq data showed the CXCR3 expression of CD8+T cells in shNC and shRRBP1 groups. (B) The correlation between CXCR3 expression and CXCL10 expression or activated CD8+ T cell based on 571 patients from TCGA-BLCA cohort and GSE13507 cohorts. (C) MB49 cells were co-cultured with CD8+ T cells, and tumor cells were stained with crystal violet. (D) Evaluation of the effect of genetic inhibition of RRBP1 on the cytotoxicity of CD8+ T cells in vitro conditioned culture model. (E) Schematic diagram of in vitro CD8+ T-cell migration assays. (F) The number of CD8+ T cells passing through the membrane of a Transwell system was analyzed by flow cytometry. (G–I) C57BL/6 mice were subcutaneously injected with 5×105 stable MB49 cells (shNC or shRRBP1 cells) (n=6). Tumor-bearing mice received intraperitoneal injection of either vehicle or anti-CXCL10 when the tumor volume reached a calculated average of 100 mm3. The tumor sizes (G), volumes (H), and weights (I) were measured. (J) Representative images of IHC and mIHC staining for CD8, CXCR3, CXCL10, IFN-γ, GZMB in different tumor tissues. (K) Flow cytometric analysis of tumor-infiltrating CD8+ T cells, CXCR3+ CD8+ T cells, IFN-γ+ CD8+ T cells or GZMB+ CD8+ T cells in distinct tumor tissues. Data are represented as mean means±SD. Statistical analysis was performed using unpaired two-tailed t-test (D, F, I, K) and two-way ANOVA with Tukey’s multiple comparison test (H). The data presented represent on one or three independent experiments. *p<0.01, **p<0.01, ***p<0.001. ANOVA, analysis of variance; BC, bladder cancer; GZMB, Granzyme B; IFN, interferon; RRBP1, ribosomal-binding protein 1; scRNA-seq, single-cell RNA sequencing; IHC, immunohistochemistry; mIHC, multiplex immunohistochemistry; BLCA, bladder urothelial carcinoma.