FIG. 5.

H. pylori OMV stimulate IL-8 production from gastric epithelial cells. AGS cells were grown alone or in the presence of different concentrations of H. pylori OMV (5 to 50 μg of protein) from either a cag PAI⁺ toxigenic strain (dark gray bars) or a cag PAI− nontoxigenic strain (light gray bars). Culture medium was collected after 24 h, and the IL-8 concentration was measured by an ELISA. The data are means ± standard errors for four independent experiments. An asterisk indicates an amount is statistically significantly different (P < 0.05) from the amount produced by untreated cells. There was a strain-dependent effect with 50 μg of OMV (P = 0.008).