title: Interleukin-21 in chronic inflammatory diseases.
abstract: Interleukin-21 (IL-21), a cytokine produced by various subsets of activated CD4+ T cells, regulates multiple innate and adaptive immune responses. Indeed, IL-21 controls the proliferation and function of CD4+ and CD8+ T lymphocytes, drives the differentiation of B cells into memory cells and Ig-secreting plasma cells, enhances the activity of natural killer cells and negatively regulates the differentiation and activity of regulatory T cells. Moroever, IL-21 can stimulate nonimmune cells to synthesize various inflammatory molecules. Excessive production of IL-21 has been described in many human chronic inflammatory disorders and there is evidence that blockade of IL-21 helps attenuate detrimental responses in mouse models of immune-mediated diseases. In this article we briefly review data supporting the pathogenic role of IL-21 in immune-inflammatory pathologies and discuss the benefits and risks of IL-21 neutralization in patients with such diseases.
authors.affiliation: Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Sarra
authors.forename: Francesco
authors.initials: F
authors.lastname: Pallone
authors.forename: Giovanni
authors.initials: G
authors.lastname: Monteleone
mesh_terms: D000818:Animals; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology / Q000378:metabolism; D005759:Gastroenteritis / Q000378:metabolism; D006801:Humans; D007378:Interleukins / Q000502:physiology*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology / Q000378:metabolism; D011565:Psoriasis / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D000098546:Interleukin-21
keywords: CD4; IL-21; autoimmunity; inflammation