Single-cell RNA-seq and spatial transcriptomics characterize CD8+ exhausted T cells in pancreatic ductal adenocarcinoma

Pancreatic cancer resists immunotherapy due to a suppressive immune microenvironment where CD8⁺ T cells play a key role. Using single‑cell RNA sequencing and spatial transcriptomics, we characterized CD8⁺ exhausted T (Tex) cells in pancreatic ductal adenocarcinoma (PDAC). We generated single‑cell profiles from PDAC tumors and matched peripheral blood mononuclear cells, and performed T cell sub‑analysis. We found CXCL13 upregulated and GZMK downregulated in CD8⁺ Tex cells. Cell‑cell interaction analysis showed that T cells most frequently interacted with myeloid cells and cancer cells via ligand‑receptor pairs; INHBA⁺ macrophages and cancer cells communicated most with CD8⁺ Tex cells. Two key LR pairs (SPP1–integrin α4β1 and PLAUR–integrin α4β1) mediated crosstalk between cancer cells and CD8⁺ Tex cells, confirmed by immunofluorescence, spatial mapping, and protein docking. High SPP1 and PLAUR expression correlated with poor prognosis in TCGA‑PAAD. These findings provide a resource for understanding CD8⁺ T cell exhaustion in PDAC.