%0 Journal Article %T Phenotype, development, and biological function of myeloid-derived suppressor cells %A Bingyi Shi %A Steven Shao %A Tingting Wu %A Yang Zhao %A Yong Zhao %J Archive of "Oncoimmunology". %D 2016 %R 10.1080/2162402X.2015.1004983 %X CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) are an important population of innate regulatory cells mainly comprising monocytic MDSCs (M-MDSCs) with a phenotype of CD11b+Ly6G£¿Ly6Chigh and granulocytic MDSCs (G-MDSCs) with a phenotype of CD11b+Ly6G+Ly6Clow in mice. They play crucial roles in the pathogenesis of cancers, chronic infections, autoimmune diseases, and transplantation. Various extracellular factors such as lipopolysaccharide (LPS), macrophage colony-stimulating factor (M-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), stem cell factor (SCF), interleukin (IL)-6, interferon gamma (IFN¦Ã), IL-1¦Â, vascular endothelial growth factor (VEGF), Hsp72, IL-13, C5a, and prostaglandin E2 (PGE2) can induce MDSC differentiation, whereas IL-4 and all-trans-retinoic acid can inhibit this process. For the intracellular signals, signal transducer and activator of transcription (STAT) family members, C/EBP¦Â and cyclooxigenase-2 (COX-2) promote MDSC function, whereas interferon regulatory factor-8 (IRF-8) and Smad3 downregulate MDSC activity. The immunosuppressive function of MDSCs is mediated through various effector molecules, primarily cellular metabolism-related molecules such as nitric oxide (NO), arginase, reactive oxygen species (ROS), transforming growth factor ¦Â (TGF¦Â), IL-10, indoleamine 2,3-dioxygenase (IDO), heme oxygenase-1 (HO-1), carbon monoxide (CO), and PGE2. In this article, we will summarize the molecules involved in the induction and function of MDSCs as well as the regulatory pathways of MDSCs %K immune modulation %K immune tolerance %K immunosuppression %K innate cells %K myeloid-derived suppressor cells %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4801459/