Expression of interleukin 8 and CD54 by human gastric epithelium after Helicobacter pylori infection in vitro

Background/Aims: Helicobacter pylori is associated with neutrophil infiltrates, although the mechanism of their recruitment is only partially defined. The aim of the study was to determine if Kato III, a human gastric epithelial cell line, expressed cytokines and the intercellular adhesion molecule 1 (ICAM-1), which could contribute to the initiation of inflammation during infection with H. pylori. Methods: Kato III cells were stimulated with H. pylori and were examined for evidence of infection, cytokine production, and the expression of ICAM-1. Results: The expression of interleukin 8 messenger RNA and immunoreactive protein by Kato III cells was significantly increased over constitutive levels within 3 hours of infection with H. pylori. Infected Kato III supernatants activated neutrophils as evidenced by increased CD11b/CD18 and decreased l-selectin that could be blocked by anti-interleukin 8. In contrast, Campylobacter jejuni, lipopolysaccharide, killed H. pylori, and supernatants from cultures of H. pylori did not increase interleukin 8. Interleukins 2 and 6; interferons alfa, beta, and gamma; and tumor necrosis factor were not produced by resting or H. pylori-stimulated Kato III cells. In addition to producing interleukin 8, Kato III constitutively expressed surface ICAM-1, which acts as an intercellular adhesion molecule for neutrophils. Conclusions: Our results indicate that H. pylori stimulates the gastric epithelium to initiate inflammation and neutrophil recruitment and activation.