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HUMAN GASTRIC BIOPSIES CULTURED IN VITRO, AN USEFUL MODEL FOR STUDIES OF HELICOBACTER PYLORI INFLAMMATORY RESPONSES
Author(s) -
Olfat Farzad O.,
Noslund Erik,
Fredman Jakob,
Borén Thomas,
Engstrand Lars
Publication year - 2000
Publication title -
journal of gastroenterology and hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.214
H-Index - 130
eISSN - 1440-1746
pISSN - 0815-9319
DOI - 10.1046/j.1440-1746.2000.00a39.x
Subject(s) - helicobacter pylori , in vitro , asymptomatic , microbiology and biotechnology , virulence , colonization , medicine , stomach , strain (injury) , gastric biopsy , biopsy , cytokine , mutant , cell culture , biology , pathology , immunology , gastritis , gene , gastroenterology , biochemistry , genetics
Objective We have developed a unique in vitro model by culturing human biopsies to create a similar environment of the human infection. By using this method we have investigated the reaction of the tissue to exposure to different clinical isolates of H. pylori. The binding/colonization ability of some type strains and some clinical isolates was analyzed. The cytokine production of the stomach tissue was measured and analyzed with respect to time, number of bacteria and defined virulence factors. Methods Donut‐shaped biopsies were removed for culture, from uninfected patients who went through surgery due to obesity. The underlying tissues were removed and the epithelial cell layer was punched out into 2 mm biopsies. After adherence of biopsies to the surface, the different H. pylori strains were added to the biopsies with different adjusted pH. Using an ELISA kit, the production of IL‐8 was analyzed and Viable Count estimates were performed. Results The production of IL‐8 started 3‐4 hours post‐infection. This was similar for all strains analyzed. Maximal difference between strains was seen in a set of two isogenic strains, where the mutant lacks the entire cag‐PAI. Another strains which activate neutrophils, also induced IL‐8 at high level. The lowest level was observed in a strain isolated from an asymptomatic patient. However, although the IL‐8 production was different for the isogenic strains, colonization pattern didnít show such variability. Conclusion Our model is based on the use of the human gastric tissues, where the tissues are vital and produce mucus. These biosies are resistant to acidic conditions as low as pH 2. Our data in this series of experiments confirmed the influence of cag‐PAI in production of IL‐8. This method can be used to study bacterium‐host cross‐talk and serve as a more reliable infection model.