Role of tumor necrosis factor-alpha and interferon-gamma in Helicobacter pylori infection.
Immune responses to Helicobacter pylori infection play important roles in gastroduodenal diseases. The contributions of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) to the induction of gastric inflammation and to the protection from H. pylori infection were investigated using TNF-alpha geneknockout (TNF-alpha(-/-)) mice and IFN-gamma gene-knockout (IFN-gamma(-/-)) mice. We first examined the colonizing ability of H. pylori strain CPY2052 in the stomach of C57BL/6 wild-type and knockout mice. The number of H. pylori colonized in the stomach of IFN-gamma(-/-) and TNF-alpha(-/-) mice was higher than that of wild-type mice. These findings suggest that TNF-alpha and IFN-gamma may play a protective role in H. pylori infection. Furthermore, we examined the contribution of TNF-alpha and IFN-gamma to gastric inflammation. The CPY2052-infected TNF-alpha(-/-) mice showed a moderate infiltration of mononuclear cells in the lamina propria and erosions in the gastric epithelium as did wild-type mice, whereas the CPY2052-infected IFN-gamma(-/-) mice showed no inflammatory findings even 6 months after infection. These results demonstrate that IFN-gamma may play an important role in gastric inflammation induced by H. pylori infection, whereas TNF-alpha may not participate in the development of inflammatory response.
Yamamoto
Toshiro
T
Department of Microbiology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Kyoto 602-8566, Japan. yamamoto@koto.kpu-m.ac.jp
Kita
Masakazu
M
Ohno
Tomoyuki
T
Iwakura
Yoichiro
Y
Sekikawa
Kenji
K
Imanishi
Jiro
J
D000818:Animals; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D005756:Gastritis / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D016481:Helicobacter Infections / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology*; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma