Single cell RNA-seq reveals the CCL5/SDC1 receptor-ligand interaction between T cells and tumor cells in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by the complex tumor microenvironment (TME), consisting of an abundance of stromal cells. Among them, tumor infiltrating T cells play a pivotal role in tumor progress. To identify the full spectrum and developmental trajectory of T cells and their crosstalk with tumor cells in PDAC, we conducted scRNA-seq analysis based on multiple datasets from our institution and open da-tabases. We delineated the cellular landscape and transcriptional dynamics of T cells in PDAC. Through the inferCNV analysis and known tumor markers, the malignant ductal cells were identified. The inter-patients heterogeneity of tumor cells was also identified. After integrating T cells and malignant ductal cells, we found the CCL5-SDC1/4 receptor-ligand interactions between them. Furthermore, we demonstrated that CCL5 pro-moted tumor cells migration via interacting with SDC1 in vitro. Our findings pave the way for characterizing the heterogeneity and development trajectory of T cells, and cell-to-cell communications in TME of PDAC, which might provide a new target for immunotherapy.