title: Anti-inflammatory effects of IL-17A on Helicobacter pylori-induced gastritis.
abstract: Helicobacter pylori-induced immune responses are skewed toward a T helper (Th) 1 phenotype. IL-17-producing Th17 cells have recently been discovered, and we examined the role of IL-17A in H. pylori-induced gastritis. Six months after inoculation with H. pylori, the mice received an intraperitoneal injection of recombinant IL-17A, anti-IL-17A antibody or irrelevant IgG(2a) for 3days. H. pylori infection markedly increased mRNA for IL-17A. Double immunofluorescence studies showed that IL-17A proteins were expressed on CD4(+) T cells, macrophages, and dendritic cells. H. pylori infection elevated mRNAs for IL-12, IFN-gamma, and TNF-alpha with increase in myeloperoxidase activity, whereas it did not affect mRNAs for IL-4 and IL-5. Neutralization of IL-17A elevated mRNAs for IFN-gamma and TNF-alpha, and myeloperoxidase activity, whereas recombinant IL-17A had a tendency to reduce these parameters. In conclusion, IL-17A exerts anti-inflammatory effects on H. pylori-induced gastritis through suppression of Th1 differentiation.
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan. kojiotani@med.osaka-cu.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Otani
authors.forename: Toshio
authors.initials: T
authors.lastname: Watanabe
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tanigawa
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Okazaki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Yamagami
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tominaga
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Oshitani
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Arakawa
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D005756:Gastritis / Q000276:immunology* / Q000382:microbiology; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori / Q000276:immunology*; D007108:Immune Tolerance; D020381:Interleukin-17 / Q000008:administration & dosage / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D020381:Interleukin-17; D011994:Recombinant Proteins