The expression profiles and regulation of PD-L1 in tumor-induced myeloid-derived suppressor cells.

ABSTRACT: Programmed death-ligand 1 (PD-L1) is an inhibitory ligand that binds to PD-1 to suppress T cell activation. PD-L1 is constitutively expressed and inducible in tumor cells, but the expression profiles and regulatory mechanism of PD-L1 in myeloid-derived suppressor cells (MDSCs) are largely unknown. We report that PD-L1 is abundantly expressed in tumor-infiltrating leukocytes in human patients with both microsatellite instable and microsatellite stable colon cancer. About 60% CD11b⁺CD33⁺HLA-DR^- MDSCs from peripheral blood of human colon cancer patients are PD-L1⁺. PD-L1⁺ MDSCs are also significantly higher in tumor-bearing mice than in tumor-free mice. Interestingly, the highest PD-L1⁺ MDSCs were observed in the tumor microenv

SUBMITTER: Lu C 

PROVIDER: S-EPMC5214087 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature