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. 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.