FIG. 5.

Increased apoptosis by cagA⁺ H. pylori strains. AGS gastric epithelial cells were infected with H. pylori cagA mutants (strains 28 and 45) or cagA⁺ strains (strains 44, 92, and 99). H. pylori and a subconfluent monolayer of AGS cells were cocultured for 16 h with or without pretreatment by PD98059 (20 μM). (A) Early apoptotic cell proportions measured by flow cytometric analysis after staining with FITC-conjugated annexin V and propidium iodide. (B) Apoptosis of AGS cells was assessed by means of cell death detection ELISA. Values refer to DNA fragmentation as measured by the enrichment factor. Values are means ± standard deviations of triplicate experiments, and representative data of three independent experiments were shown. *, P < 0.05 (compared with each result for cells without PD98059 treatment).