title: The role of IL-17 in psoriasis.
abstract: BACKGROUND
  Psoriasis is a chronic skin condition traditionally believed to involve the Th1 pathway. Recently, the IL-23/Th17/IL-17 pathway has been highlighted in the pathogenesis of psoriasis and other autoimmune inflammatory conditions. From a clinician's perspective, we sought to review the basic science data relevant to IL-17's role in psoriasis pathogenesis.
  
  
  METHODS
  We performed a Pubmed and Web of Knowledge search for English articles starting from 1990 that discussed the Th17 pathway. Search terms such as "IL-17" and "psoriasis" were utilized.
  
  
  RESULTS
  The IL-17 pathway is regulated by IL-23, a cytokine that is vital for the expansion and maintenance of the Th17 cell population. Th17 derived cytokines (IL-17A, IL-17F, IL-17A/F and IL-22) were elevated in both psoriasis-like murine models and human psoriatic lesional biopsies. Ixekizumab (anti-IL-17A) treatment of psoriasis was found to normalize levels of IL-17 downstream gene products.
  
  
  CONCLUSIONS
  Both preclinical and clinical studies support the central role of IL-17 in the pathogenesis of psoriasis.
authors.affiliation: Chicago Medical School, Rosalind Franklin University of Medicine and Science , North Chicago, IL , USA .
authors.forename: Mona
authors.initials: M
authors.lastname: Malakouti
authors.forename: Gabrielle Elena
authors.initials: GE
authors.lastname: Brown
authors.forename: Eva
authors.initials: E
authors.lastname: Wang
authors.forename: John
authors.initials: J
authors.lastname: Koo
authors.forename: Ethan C
authors.initials: EC
authors.lastname: Levin
mesh_terms: D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology*; D016207:Cytokines / Q000276:immunology; D006801:Humans; D020381:Interleukin-17 / Q000037:antagonists & inhibitors / Q000276:immunology*; D053759:Interleukin-23 / Q000276:immunology; D007378:Interleukins / Q000276:immunology; D051379:Mice; D011565:Psoriasis / Q000188:drug therapy / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology*; D000097043:Interleukin-22
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D016207:Cytokines; D020381:Interleukin-17; D053759:Interleukin-23; D007378:Interleukins; D000097043:Interleukin-22; C549079:ixekizumab
keywords: Biologics; Ixekizumab; Th17; brodalumab; secukinumab