Tumor Microenvironment following Gemcitabine Treatment Favors Differentiation of Immunosuppressive Ly6Chigh Myeloid Cells

Regulation of myeloid-derived suppressor cells (MDSC) by ongoing inflammation following repeated chemotherapy remain elusive. In this study, we show that a multidose clinical regimen of gemcitabine (GEM) treatment enhances the immunosuppressive function of monocytic MDSC (M-MDSC), although tumor development is delayed in E0771 tumor-bearing mice. Accordingly, effector IFN-γ–producing CD4 and CD8 T cells are significantly decreased in the tumor...