Fig. 3: mGluR4 shapes the immune signature in the TME of the Hepa1-6BL tumors.

A Representative plots and quantification of tumor-infiltrating CD45.2⁺ cells in Hepa1-6BL subcutaneous tumors (n = 6 mice per group). B A schematic diagram illustrating the application of CD45.2⁺ cells, purified from Hepa1-6BL tumors, for single-cell RNA sequencing and TCR analysis. C UMAP analysis of CD45.2⁺ cells. D Proportions of each cell cluster in the TME of Hepa1-6BL tumors grown in Grm4^-/- or WT mice. E GSEA-KEGG analysis of all DC clusters from Hepa1-6BL tumors. Potential functions and pathway enrichments are shown as normalized enrichment scores (NES) adjusted for multiple comparisons. F Visualization of GSEA analysis of core gene variation involved in the function and biological processes of DCs. Statistical testing was performed by permutation test. G Heat maps indicate the expression of selected genes in each DC cluster. The statistical difference was calculated by Student’s t-test. The P-values were corrected with Benjamini-Hochberg adjustment. H Flow cytometry analysis of the frequency and number of tumor-infiltrating DCs among CD45.2⁺ cells in mice bearing Hepa1-6BL subcutaneous tumors (n = 5 mice per group). I Quantitative plots of CD80 and CD86 in tumor-infiltrating DCs (n = 5 mice per group). J Schematic diagram of co-culture assay to evaluate the effect of DCs sorted from Hepa1-6BL tumor or LN on OT1 T cell proliferation and effector function. K The proliferation of CD8⁺ T cells (n = 6 biological replicates), (L) quantification of IFNγ expression (n = 6 biological replicates), and (M) the Annexin V⁺ of tumor cells (n = 5 biological replicates). N, O Representative flow plot and quantification of CD24⁺ cDC1s and SIRPα⁺ cDC2s in (N) tumors and (O) draining lymph nodes (dLN) at day 15 after tumor inoculation (n = 4 mice per group). Data were presented as mean ± SEM. Statistical significance was determined by unpaired t-test two-tailed (A, H, I, K, L, M, N, O) and one-sided (E, F, G). All biological experiments were repeated at least three times and yielded consistent results. Source data are provided as a Source Data file.