title: Analysis of interleukin-8 secretion induced by Helicobacter pylori from the gastric epithelial cell line MKN45: a mechanism independent of the intensity of cytotoxicity.
abstract: Interleukin (IL)-8, a potent chemoattractant and activator of neutrophils, has been implicated to have a major role in the pathogenesis of gastric mucosal injury by Helicobacter pylori infection. We examined the relationship between cytotoxicity and IL-8 secretion induced by H. pylori. Furthermore, whether the vacuolating cytotoxin of H. pylori mediates IL-8 secretion from gastric epithelial cell lines was examined. Among the inflammatory cytokines, messages for IL-6, IL-8 and transforming growth factor-beta 1 were produced by gastric cancer (MKN45) cells in response to exposure to the cytotoxic strain of H. pylori. MKN45 incubated with the viable cytotoxic strain of H. pylori secreted IL-8. In contrast, the supernatant of neither the cytotoxic nor the non-cytotoxic strain induced IL-8 secretion. There was no correlation between IL-8 secretion and the intensity of cytotoxicity. In conclusion, these findings suggest that IL-8 secretion from MKN45 induced by H. pylori is mediated by factors other than cytotoxicity.
authors.affiliation: Department of Internal Medicine 6, Tokai University School of Medicine, Kanagawa, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takagi
authors.forename: S
authors.initials: S
authors.lastname: Kamiya
authors.forename: Y
authors.initials: Y
authors.lastname: Koga
authors.forename: U
authors.initials: U
authors.lastname: Ohta
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Shirai
authors.forename: S
authors.initials: S
authors.lastname: Harasawa
authors.forename: T
authors.initials: T
authors.lastname: Miwa
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology; D001427:Bacterial Toxins; D003603:Cytotoxins; D004797:Enzyme-Linked Immunosorbent Assay; D004848:Epithelium / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D005753:Gastric Mucosa / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D018375:Neutrophil Activation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D013274:Stomach Neoplasms / Q000378:metabolism / Q000382:microbiology; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; D015850:Interleukin-6; D016209:Interleukin-8; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C074689:VacA protein, Helicobacter pylori