PD-L1 regulation of colonic inflammation and colorectal cancerdevelopment

PD-L1 acts as an immune checkpoint that inhibits T cell activation and suppresses colonic inflammation. We aimed at determine the cellular and molecular mechanisms underlying PD-L1 function in colon epithelium and colon cancer. scRNA-seq was perform to determine the gene expression profiles in epithelial cells and immune cells in the single-cell level. Tumors were induced in WT and PD-L1 KO mice. Analysis of WT and PD-L1 KO tumors revealed that loss of PD-L1 alters T cells, myeloid cells, B cells, and tumor-associated fibroblast subpopulations. Our finding determines that PD-L1 regulates multiple cellular populations to regulates host immune response and tumor development. Overall design: Tumor tissues were dissected from mice and digested with collagenase to make single cells. The single cells were collected using a 10xGenomics system for cDNA libraray preparation and high throughout DNA sequencing.