title: IL-2 family cytokines: new insights into the complex roles of IL-2 as a broad regulator of T helper cell differentiation.
abstract: Interleukin-2 (IL-2) is a pleiotropic cytokine that drives T-cell growth, augments NK cytolytic activity, induces the differentiation of regulatory T cells, and mediates activation-induced cell death. Along with IL-4, IL-7, IL-9, IL-15, and IL-21, IL-2 shares the common cytokine receptor γ chain, γ(c), which is mutated in humans with X-linked severe combined immunodeficiency. Herein, we primarily focus on the recently discovered complex roles of IL-2 in broadly modulating T cells for T helper cell differentiation. IL-2 does not specify the type of Th differentiation that occurs; instead, IL-2 modulates expression of receptors for other cytokines and transcription factors, thereby either promoting or inhibiting cytokine cascades that correlate with each Th differentiation state. In this fashion, IL-2 can prime and potentially maintain Th1 and Th2 differentiation as well as expand such populations of cells, whereas it inhibits Th17 differentiation but also can expand Th17 cells.
authors: Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1674, USA.
authors: Wei
authors: W
authors: Liao
authors: Jian-Xin
authors: JX
authors: Lin
authors: Warren J
authors: WJ
authors: Leonard
mesh_terms: D000818:Animals; D016923:Cell Death / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology*; D049109:Cell Proliferation; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007109:Immunity; D007155:Immunologic Factors / Q000276:immunology / Q000378:metabolism; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D018121:Receptors, Cytokine / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology*; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology*; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology; D053632:X-Linked Combined Immunodeficiency Diseases / Q000235:genetics / Q000276:immunology
chemical_list: D007155:Immunologic Factors; D007376:Interleukin-2; D018121:Receptors, Cytokine; D014157:Transcription Factors