Helicobacter pylori heat-shock protein 60 induces inflammatory responses through the Toll-like receptor-triggered pathway in cultured human gastric epithelial cells

Department of Bacteriology, Okayama University, Okayama, Okayama, Japan
Microbiology (Impact Factor: 2.56). 01/2005; 150(Pt 12):3913-22. DOI: 10.1099/mic.0.27527-0
Source: PubMed


Contact between Helicobacter pylori and gastric epithelial cells results in activation of NF-kappaB followed by secretion of interleukin (IL)-8. However, host-cell receptor(s) and their ligands involved in H. pylori-related IL-8 production have yet to be fully defined. In this study, the interaction between Toll-like receptors (TLRs), which are host receptors for pathogens involved in the innate immune response, and heat-shock protein (HSP) 60, an immune-potent antigen of H. pylori, was examined during H. pylori-induced IL-8 secretion in vitro. Recombinant H. pylori HSP60 (rHpHSP60) was prepared and added to cultured KATO III human gastric epithelial cells with or without pre-incubation with mouse monoclonal anti-TLR2 or anti-TLR4 antibodies. IL-8 mRNA expression and IL-8 protein release were analysed by Northern blotting and immunoassay. Involvement of NF-kappaB activation was analysed immunocytochemically by anti-NF-kappaB p65 antibody and ammonium pyrrolidinedithiocarbamate (PDTC), an inhibitor of NF-kappaB-mediated transcriptional activation. rHpHSP60 induced IL-8 mRNA expression and IL-8 secretion in a dose-dependent manner in KATO III cells. Anti-TLR2 antibody inhibited rHpHSP60-induced IL-8 secretion by 75 %, and anti-TLR4 antibody inhibited it by 30 %. rHpHSP60 induced nuclear translocation of NF-kappaB p65, which was inhibited by pretreatment with anti-TLR2 antibody. Treatment with PDTC significantly decreased the secretion of IL-8 induced by rHpHSP60. These findings suggest that H. pylori HSP60 activates NF-kappaB and induces IL-8 production through TLR-triggered pathways in gastric epithelial cells. Thus, it is possible that H. pylori HSP60 and TLR interaction in host cells contributes to the development of gastric inflammation caused by H. pylori infection.

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Available from: Motowo Mizuno, Jan 30, 2014
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    • "In normal gastric epithelial cells, constitutive and inducible expression of TLR2, TLR4 and TLR5 mRNA and protein has been shown in response to bacterial components and whole organisms (115, 116). Inducible expression of TLR4 and TLR2-dependent secretion of cytokines in vitro can be inhibited by blocking anti-TLR2 antibodies (117). "
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    • "As the first barrier against bacteria invasion, gastric epithelial cells initiate the natural immunity of gastric mucosa by expressing Toll-like receptors (TLRs) after H.pylori colonization [1]–[3]. Previous studies indicate that the expression of TLR4 in gastric epithelial cells activates myeloid differentiation protein 88 (MyD88) leading to NF-κB activity and the production of cytokines/chemokines, which causes chemotaxis of monocytes/macrophages and polymorphonuclear leukocyte infiltration [4], [5]. Therefore, gastric epithelial cells play an important role in the immune responses and chronic inflammation of gastric mucosa. "
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