title: Effect of interleukin (IL)-35 on IL-17 expression and production by human CD4+T cells.
abstract: BACKGROUND
  Interleukin (IL)-17 produced by mainly T helper 17 (Th17) cells may play an important destructive role in chronic periodontitis (CP). Thus, anti-inflammatory cytokines, such as IL-35, might have a beneficial effect in periodontitis by inhibiting differentiation of Th17 cells. Th17 differentiation is regulated by the retinoic acid receptor-related orphan receptor (ROR)α(encoded byRORA) and RORγt (encoded byRORC). However, the role of IL-35 in periodontitis is not clear and the effect of IL-35 on the function of Th17 cells is still incompletely understood. Therefore, we investigated the effects of IL-35 on Th17 cells.
  
  
  METHODS
  Peripheral blood mononuclear cells (PBMCs) were sampled from three healthy volunteers and three CP patients and were analyzed by flow cytometry for T cell population. Th17 cells differentiated by a cytokine cocktail (recombinant transforming growth factor-β, rIL-6, rIL-1β, anti-interferon (IFN)-γ, anti-IL-2 and anti-IL-4) from PBMCs were cultured with or without rIL-35.IL17A(which usually refers to IL-17),RORAandRORCmRNA expression was analyzed by quantitative polymerase chain reaction, and IL-17A production was determined by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The proportion of IL-17A+CD4+slightly increased in CP patients compared with healthy controls, however, there were no significant differences in the percentage of IL-17A+CD4+as well as IFN-γ+CD4+and Foxp3+CD4+T cells between healthy controls and CP patients.IL17A,RORAandRORCmRNA expression was significantly increased in Th17 cells induced by the cytokine cocktail, and the induction was significantly inhibited by addition of rIL-35 (1 ng/mL). IL-17A production in Th17 cells was significantly inhibited by rIL-35 addition (1 ng/mL).
  
  
  CONCLUSIONS
  The present study suggests that IL-35 could directly suppress IL-17 expression via RORαand RORγt inhibition and might play an important role in inflammatory diseases such as periodontitis.
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Okada
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Takeki
authors.initials: T
authors.lastname: Fujimura
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kikuchi
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Aino
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kamiya
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Ario
authors.initials: A
authors.lastname: Izawa
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Iwamura
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Goto
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Iichiro
authors.initials: I
authors.lastname: Okabe
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Miyake
authors.affiliation: Department of Microbiology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hasegawa
authors.affiliation: Department of Integrative Education of Pharmacy, School of Pharmacy, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Makio
authors.initials: M
authors.lastname: Mogi
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University , Nagoya , Aichi , Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Mitani
keywords: Interleukin-17; Interleukin-35; Periodontitis; Retinoic acid receptor-related orphan receptor; Th17