title: Suppression of T cells by myeloid-derived suppressor cells in cancer.
abstract: Myeloid-derived suppressor cells (MDSCs) are a population of immature myeloid cells defined by their immunosuppression. Elevated levels of certain soluble cytokines in tumor microenvironment, such as IL-6 and IL-10, contribute to the recruitment and accumulation of tumor-associated MDSCs. In turn, MDSCs secret IL-6 and IL-10 and form a positive self-feedback to promote self-expansion. MDSCs also release other soluble cytokines such as TGF-β and chemokines to exert their suppressive function by induction of regulatory T cells. Exhaustion of some amino acids by MDSCs with many secretory enzymes or membrane transporters as well as their metabolites leads to blockage of T cells development. The interaction of membrane molecules on MDSCs and T cells leads inactivation and apoptosis of T cells. There may be one or some dominant mechanism(s) by which MDSCs impair the immune system in different tumor microenvironment. Thus, it is important to identify the subpopulations of MDSCs and clarify the dominant mechanism(s) through which MDSCs inhibit antitumor immunity in order to establish a more individual immunotherapy by eliminating MDSCs-mediated suppression. Currently studies concentrated on therapeutic strategies targeting MDSCs have obtained promising results. However, more studies are needed to demonstrate their clinical safety and efficacy.
authors.affiliation: Department of Immunology, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Immunology and Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
authors.forename: Jieying
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Immunology, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Immunology and Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Cancer Molecular Diagnostic Core, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
authors.forename: Pengpeng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Immunology, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Immunology and Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Yu
authors.affiliation: Department of Immunology, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Immunology and Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wei
authors.affiliation: Department of Immunology, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Immunology and Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Immunology, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Immunology and Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China; Cancer Molecular Diagnostic Core, National Clinical Research Center of Cancer, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China. Electronic address: yu_jinpu@sina.com.
authors.forename: Jinpu
authors.initials: J
authors.lastname: Yu
mesh_terms: D000818:Animals; D006801:Humans; D007109:Immunity; D007165:Immunosuppression Therapy; D007167:Immunotherapy / Q000379:methods*; D000072737:Myeloid-Derived Suppressor Cells / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D019139:Tumor Escape; D059016:Tumor Microenvironment
keywords: Cancer; Immune suppression; Myeloid-derived suppressor cell; T cell; Targeted therapy