title: Hyperexpression of FcgammaRI and Toll-like receptor 4 in the intestinal mast cells of Crohn's disease patients.
abstract: We previously reported that human mast cells (MCs) express high affinity IgG receptor (FcgammaRI) and Toll-like receptor 4 (TLR4) in response to interferon (IFN)-gamma in vitro. The number of MCs is known to increase in Crohn's disease (CD) and ulcerative colitis (UC). We aimed to examine the expression and function of the receptors in these diseases by immunohistochemistry of the colonic mucosae and by in vitro experiments. The density of MCs expressing FcgammaRI, TLR4, or both proteins was significantly higher in CD than in UC or control samples. The density of TNF-alpha(+) MCs expressing FcgammaRI or TLR4 was significantly higher in CD than in control samples. LPS and IgG1 cross-linking synergistically induced a high level of TNF-alpha production in IFN-gamma-treated human MCs. Hyperexpression of FcgammaRI and TLR4 on MCs was related to the high frequency of TNF-alpha expression in CD, suggesting the activation of MCs via these receptors in vivo.
authors.affiliation: Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Kobayashi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okamura
authors.forename: Tatsukuni
authors.initials: T
authors.lastname: Ohno
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Saito
authors.forename: Masatomo
authors.initials: M
authors.lastname: Mori
authors.forename: Chisei
authors.initials: C
authors.lastname: Ra
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Okayama
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D003093:Colitis, Ulcerative / Q000276:immunology*; D003424:Crohn Disease / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000276:immunology* / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000473:pathology; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology / Q000473:pathology; D017452:Receptors, IgG / Q000096:biosynthesis* / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis* / Q000276:immunology; D053802:Tryptases / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology