Proinflammatory cytokines and Helicobacter pylori stimulate CC-chemokine expression in gastric epithelial cells

Abstract

Helicobacter pylori (H. pylori) has been shown to stimulate secretion of IL-8, a CXC-chemokine, from gastric epithelial cells, and this process is important in the induction of gastric mucosal inflammation associated with H. pylori infection. However, considering the biological effects and target cells, CC-chemokines may also be playing an important role in H. pylori-associated gastritis. In the present study, we investigated the expression of IL-8 (CXC-chemokine), MCP-1 (CC-chemokine), and RANTES (CC-chemokine) in human gastric mucosa by RT-PCR analysis. The positive rates of IL-8, MCP-1, and RANTES in 35 patients were 68.5%, 80%, and 80% respectively, suggesting the possible importance of CC-chemokines. We next examined the production of MCP-1 by MKN28 gastric epithelial cells. MKN28 cells were found to secrete MCP-1 in response to IL-1 beta or TNFalpha in a dose- and time-dependent manner. Quantitative RT-PCR analysis showed the induction of MCP-1 mRNA by these proinflammatory cytokines. Co-culture with H. pylori also induced the expression of MCP-1 mRNA. These results suggest that gastric epithelial cells secrete CC chemokine MCP-1 in response to proinflammatory cytokines and H. pylori, and this process may also be important in the chronic gastric inflammation associated with H. pylori infection.