title: Cloning and characterization of a novel membrane-associated antigenic protein of Helicobacter pylori.
abstract: Infection by Helicobacter pylori, a noninvasive bacterium, induces chronic leukocyte infiltration in the stomach by still largely unknown molecular mechanisms. We investigated the possibility that a membrane protein of H. pylori induces an inflammatory reaction in the subepithelial tissue of the stomach. By generating an expression library of H. pylori chromosomal DNA and screening with rabbit antiserum raised to a membrane fraction of H. pylori and sera of infected patients, we cloned a 16.0-kDa protein (HP-MP1) which appeared to attach to the inner membrane of the H. pylori in a homodimeric form. Anti-HP-MP1 antibodies were detected in the sera of infected patients but not in those of uninfected controls. Coincubation of monocytes with recombinant HP-MP1 led to cell activation and production of interleukin-1alpha (IL-1alpha), tumor necrosis factor alpha, IL-8, and macrophage inflammatory protein 1alpha. The results indicate that HP-MP1 is an antigenic membrane-associated protein of H. pylori which potentially activates monocytes. This suggests that HP-MP1 may play roles in the pathogenesis of perpetual tissue inflammation associated with H. pylori infection.
authors.affiliation: Divisions of Clinical Bio-Regulatory Science, Graduate School of Medicine, Kyoto University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Wakatsuki
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Itoh
authors.forename: K
authors.initials: K
authors.lastname: Murakami
authors.forename: A
authors.initials: A
authors.lastname: Mizoguchi
authors.forename: T
authors.initials: T
authors.lastname: Usui
authors.forename: T
authors.initials: T
authors.lastname: Chiba
authors.forename: T
authors.initials: T
authors.lastname: Kita
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D002478:Cells, Cultured; D003001:Cloning, Molecular; D016207:Cytokines / Q000096:biosynthesis; D005798:Genes, Bacterial / Q000276:immunology; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D011994:Recombinant Proteins / Q000302:isolation & purification; D014510:Urease / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D016207:Cytokines; C116708:HP-MP1 protein, Helicobacter pylori; D011994:Recombinant Proteins; D014510:Urease