title: Characterization of IL-17A-producing cells in celiac disease mucosa.
abstract: Celiac disease (CD) is a gluten-sensitive enteropathy associated with a marked infiltration of the mucosa with IFN-gamma-secreting Th1 cells. Recent studies have shown that a novel subset of T cells characterized by expression of high levels of IL-17A, termed Th17 cells, may be responsible for pathogenic effects previously attributed to Th1 cells. In this study, we characterized the expression of IL-17A-producing cells in CD. By real-time PCR and ELISA, it was shown that expression of IL-17A RNA and protein is more pronounced in active CD biopsy specimens in comparison with inactive CD and normal mucosal biopsy specimens. Flow cytometry confirmed that IL-17A is overproduced in CD mucosa and that CD4(+) and CD4(+)CD8(+) cells were major sources. The majority of IL-17A-producing CD4(+) and CD4(+)CD8(+) cells coexpressed IFN-gamma but not CD161. The addition of a peptic-tryptic digest of gliadin to ex vivo organ cultures of duodenal biopsy specimens taken from inactive CD patients enhanced IL-17A production by both CD4(+) and CD4(+)CD8(+) cells. Because we previously showed that IL-21, a T cell-derived cytokine involved in the control of Th17 cell responses, is overproduced in CD, we next assessed whether IL-17A expression is regulated by IL-21. Blockade of IL-21 activity by a neutralizing IL-21 Ab reduced IL-17A expression in cultures of active CD and peptic-tryptic digest of gliadin-treated CD biopsy specimens. In conclusion, our data show that IL-17A is increased in CD and is produced by cells that also make IFN-gamma.
authors.affiliation: Dipartimento di Medicina Interna, Università Tor Vergata, Rome, Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Monteleone
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Sarra
authors.forename: Giovanna
authors.initials: G
authors.lastname: Del Vecchio Blanco
authors.forename: Omero Alessandro
authors.initials: OA
authors.lastname: Paoluzi
authors.forename: Eleonora
authors.initials: E
authors.lastname: Franzè
authors.forename: Daniele
authors.initials: D
authors.lastname: Fina
authors.forename: Alessia
authors.initials: A
authors.lastname: Fabrizi
authors.forename: Thomas T
authors.initials: TT
authors.lastname: MacDonald
authors.forename: Francesco
authors.initials: F
authors.lastname: Pallone
authors.forename: Giovanni
authors.initials: G
authors.lastname: Monteleone
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002446:Celiac Disease / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D004386:Duodenum / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism / Q000502:physiology; D007371:Interferon-gamma / Q000096:biosynthesis; D020381:Interleukin-17 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D007378:Interleukins / Q000037:antagonists & inhibitors / Q000502:physiology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D009924:Organ Culture Techniques; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology; D000098546:Interleukin-21
chemical_list: C508717:IL17A protein, human; D018836:Inflammation Mediators; D020381:Interleukin-17; D007378:Interleukins; D007371:Interferon-gamma; D000098546:Interleukin-21