title: Regulatory T cells in cancer immunotherapy.
abstract: FOXP3(+)CD25(+)CD4(+) regulatory T (Treg) cells, crucial for the maintenance of immunological self-tolerance, are abundant in tumors. Most of them are chemo-attracted to tumor tissues, expanding locally and differentiating into a Treg-cell subpopulation that strongly suppresses the activation and expansion of tumor-antigen-specific effector T cells. Several cancer immunotherapies targeting FOXP3(+)CD4(+) Treg cells, including depletion of Treg cells, are currently being tested in the clinic. In addition, clinical benefit of immune-checkpoint blockade, such as anti-CTLA-4 monoclonal antibody therapy, could be attributed at least in part to depletion of FOXP3(+)CD4(+) Treg cells from tumor tissues. Thus, optimal strategies need to be established for reducing Treg cells or attenuating their suppressive activity in tumor tissues, together with activating and expanding tumor-specific effector T cells.
authors.affiliation: Experimental Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Nishikawa
authors.affiliation: Experimental Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan. Electronic address: shimon@ifrec.osaka-u.ac.jp.
authors.forename: Shimon
authors.initials: S
authors.lastname: Sakaguchi
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology; D018450:Disease Progression; D006801:Humans; D007167:Immunotherapy; D009369:Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm