Interleukin-8 production in primary cultures of human gastric epithelial cells induced by Helicobacter pylori

Interleukin-8 (lL-8) production by the gastric mucosa is increased in Helic obacter pylori infection. Previous studies indicated that H. pylori induces IL-8 synthesis in cancer cell lines, and the ability of H. pylori to stimu late IL-S production is supposed to be associated with cagA and other cae p athogenicity island genes, including picB gene. In the present study, we in vestigated the induction of IL-8 in primary cultures of normal human gastri c epithelial cells to elucidate the IL-8 induction by wild type strains and by the pica knockout strain. Human gastric epithelial cells were obtained from surgically resected specimens from four patients. Three H. pylori stra ins (TN2F4; type 1 clinical isolate, TN2F4ml: isogenic picB mutant of TN2F4 , Tx30a: type 2 strain) were cocultured with the normal gastric epithelial cells or the transformed MKN-28. IL-8 levels in culture medium were determi ned by enzyme immunoassay. Human gastric epithelial cells produced IL-8 at a 10-50 times higher level than MKN-28 did when cocultured with TN2F4. The mutant TN2F4ml induced IL-8 at significantly lower levels than the parent s train. Cells from four patients behaved similarly on IL-8 production. The r esults of the present study demonstrated the induction of IL-8 in normal ga stric epithelial cells, suggesting that pica gene product may play an essen tial role ill vivo.