title: Development of IL-17-mediated delayed-type hypersensitivity is not affected by down-regulation of IL-25 expression.
abstract: BACKGROUND
  IL-25, which is a member of the IL-17 family, induces Th2 cell differentiation and Th2 cytokine production, contributing to induction of Th2-type immune responses and diseases, as a result of which it suppresses Th1- and Th17-type immune responses.
  
  
  METHODS
  To elucidate the role of IL-25 in the pathogenesis of IL-17-mediated delayed-type hypersensitivity (DTH), IL-25-deficient mice were sensitized with methylated BSA (mBSA), and then a DTH reaction was induced by mBSA challenge. mBSA-specific T-cell induction was assessed on the basis of cell proliferation and cytokine production. The DTH reaction was evaluated on the basis of tissue swelling, histology and inflammatory mediator expression.
  
  
  RESULTS
  IL-25 expression was markedly reduced in local DTH lesions. However, mBSA-specific Th1, Th2 and Th17 cell induction, and the mBSA-induced DTH reaction were comparable in IL-25-deficient and wild-type mice.
  
  
  CONCLUSIONS
  IL-25 is not essential for differentiation of Th1, Th2 and Th17 cells in the sensitization phase or induction of local inflammation in the elicitation phase of the mBSA-induced DTH reaction.
authors.affiliation: Department of Allergy and Immunology, National Research Institute for Child Health and Development, Tokyo, Japan.
authors.forename: Akina
authors.initials: A
authors.lastname: Ishii
authors.forename: Keisuke
authors.initials: K
authors.lastname: Oboki
authors.forename: Aya
authors.initials: A
authors.lastname: Nambu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Morita
authors.forename: Tatsukuni
authors.initials: T
authors.lastname: Ohno
authors.forename: Naoki
authors.initials: N
authors.lastname: Kajiwara
authors.forename: Ken
authors.initials: K
authors.lastname: Arae
authors.forename: Hajime
authors.initials: H
authors.lastname: Sudo
authors.forename: Ko
authors.initials: K
authors.lastname: Okumura
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Saito
authors.forename: Susumu
authors.initials: S
authors.lastname: Nakae
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D015536:Down-Regulation; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007114:Immunization; D020381:Interleukin-17 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
chemical_list: C486701:IL25 protein, human; D020381:Interleukin-17