INTERACTION BETWEEN HELICOBACTER-PYLORI AND HUMAN GASTRIC EPITHELIAL-CELLS IN CULTURE - EFFECT OF ANTIULCER DRUGS

A human in vitro model to study the interaction between Helicobacter p ylori and gastric epithelial cells was developed using primary culture s of gastric mucosal cells (isolated from gastric biopsies or operativ e specimen and maintained in culture for 2 weeks) as well as the well- differentiated human gastric carcinoma cell line HM02, the undifferent iated gastric tumour cell line HM51, and the laryngeal epithelial cell line HEp-2. Primary cultures and all cell lines were exposed to seven isolates of H. pylori isolated from gastritis and duodenal ulcer pati ents. Microbial adherence was assessed by microscopical evaluation of Giemsa-stained preparations and by culturing the viable bacteria attac hed to the epithelial cells. All H. pylori isolates adhered to the gas tric cells in primary culture, to HM02 cells, and to HEp-2 cells with the greatest binding affinity found in primary gastric cells. No adher ence was detected in HM51 cells. H. pylori adherence was dependent on bacterial load, incubation time, and temperature. There was no differe nce in microbial binding between H. pylori isolates derived from gastr itis and duodenal ulcer patients. The effect of antiulcer drugs on H. pylori adherence was investigated by pre-incubating isolates of H. pyl ori with omeprazole, cimetidine, and bismuth subcitrate. Omeprazole an d cimetidine failed to significantly influence microbial adherence. In contrast, bismuth subcitrate already in concentrations below the MIC range decreased H. pylori adherence in gastric epithelial cells and in HEp-2 cells substantially. Our study shows that primary cultured huma n gastric mucosal cells and the human gastric carcinoma cell line HM02 provide suitable in vitro models for the study of the interactions be tween H. pylori and the gastric epithelium. This gastric cell model is characterized by a high affinity for H. pylori binding.