An expansion of different myeloid derived suppressive cell (MDSC) subsets can be detected in the blood and secondary lymphoid organs of early and advanced pancreatic ductal adenocarcinoma (PDAC) patients. Double negative (CD14-HLA-DR-) MDSCs are frequently induced by PDACs. In addition, by releasing S100A8 and S100A9, advanced PDAC lesions cause an expansion of highly immunosuppressive CD33+CD14+HLA-DR- monocytic MDSCs expressing low levels of cytotoxic T lymphocyte antigen 4 (CTLA4) on the cell surface.
Keywords: CD8+ T cells; CTLA4; PDL1; S100 proteins; dendritic cells; myeloid-derived suppressive cells; pancreatic ductal adenocarcinoma.