title: Current data on IL-17 and Th17 cells and implications for graft versus host disease.
abstract: Human interleukin 17 was first described in 1995 as a new cytokine produced primarily by activated T CD4+ cells that stimulate the secretion of IL-6 and IL-8 by human fibroblasts, besides increasing the expression of ICAM-1. Various authors have reported that IL-17A has a role in the protection of organisms against extracellular bacteria and fungi due to the capacity of IL-17A to recruit neutrophils to the areas of infection, evidencing a pathological role in various models of autoimmune diseases, such as experimental autoimmune encephalitis and arthritis. The participation of IL-17A has also been described in the acute rejection of organ transplants and graft versus host disease. However, the greatest revolution in research with IL-17 happened in 2000, when it was proposed that IL-17 cannot be classified as Th1 or Th2, but rather, simply as a new lineage of IL-17-producing T-cells. These findings modified the previously established Th1/Th2 paradigm, leading to the definition of the CD3+ CD4+ Th17 cellular subtype and establishment of a new model to explain the origin of various immune events, as well as its implication in the graft versus host disease that is discussed in depth in this article.
authors.forename: Marília
authors.initials: M
authors.lastname: Normanton
authors.forename: Luciana Cavalheiro
authors.initials: LC
authors.lastname: Marti
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004195:Disease Models, Animal; D006086:Graft vs Host Disease / Q000276:immunology* / Q000503:physiopathology; D006801:Humans; D020381:Interleukin-17 / Q000276:immunology*; D051379:Mice; D058504:Th17 Cells / Q000276:immunology*
chemical_list: D020381:Interleukin-17