Helicobacter pylori CagA induced interleukin-8 secretion in gastric epithelial cells

Aim: Since, contradictory data have been reported about the effect of diverse variants of H. pylori virulence factors on IL-8 induction, we aimed to analyze the effect of this diversity on levels of IL-8 secretion in AGS cell line. Background: Helicobacter pylori colonizes the human stomach and induces the activation of inflammatory cytokines, including interleukin (IL)-8, in the gastric mucosa. This induction promotes neutrophil and monocyte recruitment that causes gastric tissue damage. Methods: To determine whether different strains of H. pylori and their CagA variants have possible roles on IL-8 induction, polarized AGS cell line was infected with CagA+ H. pylori strains carrying different EPIYA motifs (ABCCC and ABC) and CagA- strain for 24 hours. Difference in stimulation of IL-8 was measured by ELISA. Results: IL-8 secretion was elevated in the treated cells with CagA encoding strains compared with the negative one. Furthermore, a noticeably increased level of IL-8 induction was measured by the CagA-EPIYA type ABCCC encoding strain in compare to that carried EPIYA type ABC Conclusion: Results of this study provide new evidence about different effects of H. pylori strains and possible roles of their CagA variants on IL-8 induction. It seems that not only carriage of cagA and its expression, but also diversity in EPIYA motif be involved in IL-8 induction in the gastric epithelial cells.