FIGURE 1.

Helicobacter pylori exposure increased the frequency of EBV infection of gastric epithelial cells. A, Experimental EBV infection to H. pylori‐exposed epithelial cells is performed in accordance with the illustrated time schedule. B‐D, AGS cells (B), MKN28 cells (C), and GES‐1 cells (D) were exposed to H. pylori, then infected with eGFP‐EBV. The efficiency of infection was determined by detecting eGFP using a fluorescence microscope (top) or flow cytometry (left bottom). The efficiency of infection was also determined by EBV copy number analysis (right bottom). E, Neither CagA nor VacA was involved in the enhancement of EBV infection through H. pylori exposure, but cagPAI was involved. Before incubation with EBV, AGS cells were exposed to wild‐type, CagA knockout (KO), VacA‐KO, and cagPAI‐KO H. pylori strains, respectively. The frequency of EBV infection was confirmed using FACS analysis. *P < .05, **P < .01. White column: unexposed cells, black column: wild‐type H. pylori‐exposed cells, gray column: CagA, VacA, or cagPAI‐KO H. pylori‐exposed cells. WT: wild‐type H. pylori. All experiments were performed 3 times and the average value and SD were described