Effect of H. pylori infection on the induction and secretion of IL-8 by gastric epithelial cells.

(A) Transcriptional activation of IL-8 gene in AGS cells, infected by the corresponding H. pylori mutant strains, expressing CagA with variable numbers of functional (EPIYA-C) or defective (EPIFA-C) phosphorylation motifs. IL-8 gene transcriptional activation was determined by a Quantitative Real Time PCR at 2, 4 and 24h post-infection. Statistical analysis was done by Student t-test and levels of significance depicted are *<0.05, **<0.01, ***<0.001, ****<0.0001. (B) IL-8 concentration levels determined by ELISA, in the supernatants of AGS cells, infected by H. pylori mutant strains. Statistical analysis and levels of significance as in (A).