title: IL-2: a two-faced master regulator of autoimmunity.
abstract: CD4(+) T-cell (Th) cytokines provide important regulatory and effector functions of T-cells. Among them, IL-2 plays a unique role. IL-2 is required for the generation and maintenance of regulatory T-cells (Treg) to provide lifelong protection from autoimmune disease. Whether IL-2 is also required for autoimmune disease development is less clear as Il2(-/)(-) mice themselves spontaneously develop multi-organ inflammation (MOI). In this communication, we discuss evidence that support the thesis that IL-2 is required for the development of autoimmune response, although some aspects of autoimmune response are not regulated by IL-2. Potential IL-2-dependent mechanisms operating at specific stages of the inflammation process are presented. The interplays among Treg, IL-2, autoimmune response and adaptive immunity are discussed. Overall, available information indicates that IL-2 is a two-faced master regulator of autoimmunity: one to prevent autoimmunity while the other promotes autoimmune response. The latter is an unfortunate consequence of IL-2 function that is used to promote the adaptive immune response against foreign antigens and pathogens.
authors.affiliation: Center for Immunity, Inflammation and Regenerative Medicine, Department of Medicine, University of Virginia, VA, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Sharma
authors.forename: Shu Man
authors.initials: SM
authors.lastname: Fu
authors.forename: Shyr-Te
authors.initials: ST
authors.lastname: Ju
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000941:Antigens / Q000276:immunology; D015551:Autoimmunity / Q000276:immunology*; D006801:Humans; D007249:Inflammation / Q000276:immunology; D007376:Interleukin-2 / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D018448:Models, Immunological; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
chemical_list: D000941:Antigens; D007376:Interleukin-2