T helper 17 cells: discovery, function, and physiological trigger.
In the few years since their discovery, T helper 17 cells (T(H)17) have been shown to play an important role in host defense against infections, and in tissue inflammation during autoimmunity. T(H)17 cells produce IL-17, IL-21, IL-10, and IL-22 cytokines, and thus have broad effects on a variety of tissues. Notably, the requirement for the immunosuppressive cytokine TGF-beta along with the pro-inflammatory cytokine IL-6 for T(H)17 differentiation supports the intimate relationship between the T(H)17 subset and FOXP3(+) regulatory T cells. Here, we discuss current knowledge on effector functions and differentiation of the T(H)17 lineage. Furthermore, we now know of a physiological stimulus for T(H)17 differentiation: innate immune recognition of cells undergoing apoptosis as a direct result of infection induces unique development of this subset. As our knowledge of T(H)17 and T regulatory cells grows, we are building on a new framework for the understanding of effector T cell differentiation and the biology of CD4(+) T cell adaptive immune responses.
Torchinsky
Miriam Beer
MB
Department of Medicine, Immunology Institute, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA.
Blander
J Magarian
JM
D000818:Animals; D015551:Autoimmunity / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D007249:Inflammation / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D020381:Interleukin-17 / Q000276:immunology*; D007378:Interleukins / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D050796:STAT3 Transcription Factor / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D000097043:Interleukin-22; D000098546:Interleukin-21
D016207:Cytokines; D016753:Interleukin-10; D020381:Interleukin-17; D007378:Interleukins; D011948:Receptors, Antigen, T-Cell; D050796:STAT3 Transcription Factor; D000097043:Interleukin-22; D000098546:Interleukin-21