title: Immune reactions against elongation factor 2 kinase: specific pathogenesis of gastric ulcer from Helicobacter pylori infection.
abstract: Helicobacter pylori (H. pylori) infection is a definite causative factor for gastric ulcers (GUs). In the present study we detected a specific antigen of gastric epithelial cells (HGC-27) using cell ELISA, which was recognized by the sera of GU patients (n = 20) but not in patients with chronic gastritis (CG; n = 20) or in healthy volunteers (HC; n = 10). This antigen was over-expressed by a stressful (heat-stressed) environment, and was identified as elongation factor 2 kinase (EF-2K) by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes) from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1) and cytotoxic T lymphocyte (CTL) as opposed to those from CG patients. The target cells (HGC-27) expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU.
authors.affiliation: Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. k-ayada@sj8.so-net.ne.jp
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ayada
authors.forename: Kenji
authors.initials: K
authors.lastname: Yokota
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Kawahara
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hirai
authors.forename: Tomoki
authors.initials: T
authors.lastname: Inaba
authors.forename: Masahide
authors.initials: M
authors.lastname: Kita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okada
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Oguma
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D002460:Cell Line; D002908:Chronic Disease; D054736:Elongation Factor 2 Kinase / Q000276:immunology* / Q000378:metabolism; D005753:Gastric Mucosa / Q000276:immunology / Q000382:microbiology; D005756:Gastritis / Q000276:immunology / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology* / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D013276:Stomach Ulcer / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology
chemical_list: D001323:Autoantibodies; D054736:Elongation Factor 2 Kinase