Helicobacter pylori infection and CagA protein translocation in human primary gastric epithelial cell culture

Background: Increasing evidence has shown that Helicobacter pylori CagA protein translocation into gastric epithelial cells plays an important role in the development of gastric inflammation and malignancy. Translocated CagA undergoes tyrosine phosphorylation in gastric adenocarcinoma cell line cells, and CagA involves disruption of cellular apical-junction complex in Madin-Darby canine kidney cells. Methods: To elucidate whether these events take place in normal human gastric epithelium, we infected human primary gastric epithelial cells with H. pylori. Results: Our results demonstrate that CagA protein was translocated into primary gastric epithelial cells and tyrosine phosphorylated. The translocated CagA induces cytoskeletal rearrangement and the disruption of tight junctions in primary gastric epithelial cells. Conclusions: This study provides direct evidence of the modulation of gastric epithelial cells by CagA protein translocation, and advances our understanding of the pathogenesis of H. pylori infection.