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: 2.84). 01/2005; 150(Pt 12):3913-22. DOI: 10.1099/mic.0.27527-0
Source: PubMed

ABSTRACT 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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    • "Although the single cysteine residue within HpHsp60 was found not to be involved in the formation of an intermolecular disulfide bond, the residue did contribute to HpHsp60 structural integrity and is relevant to production of the pro-inflammatory cytokines IL-8 and TNF-a. H. pylori Hsp60 has been found to induce IL-8 release in both gastric epithelial cells [11] and monocytes/ macrophages [10] through the Toll-like receptor (TLR)-2/4-medi- ated signal pathway. By engagement with TLR-2/TLR-4, HpHsp60 activates mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and p38 and then induces the nuclear translocation of NF-jB to trigger TNF-a and IL-8 production [10]. "
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    ABSTRACT: Helicobacter pylori heat shock protein 60 (HpHsp60) was first identified as an adhesion molecule associated with H. pylori infection. Here we have analyzed the structure of HpHsp60 via amino acid BLAST, circular dichroism, and electrophoresis and the results indicate that most recombinant HpHsp60 molecules exist as dimers or tetramers, which is quite different from Escherichia coli Hsp60. Treatment of human monocytic cells THP-1 with HpHsp60 was found to up-regulate a panel of cytokines including IL-1alpha, IL-8, IL-10, IFN-gamma, TNF-alpha, TGF-beta, GRO, and RANTES. Carboxymethylated HpHsp60 molecules with a switched oligomeric status were able to further enhance NF-kappaB-mediated IL-8 and TNF-alpha secretion in THP-1 cells compared to unmodified HpHsp60 molecules. These results indicated that the oligomeric status of HpHsp60s might have an important role in regulating host inflammation and thus help facilitate H. pylori persistent infection.
    Biochemical and Biophysical Research Communications 09/2009; 388(2):283-9. DOI:10.1016/j.bbrc.2009.07.159 · 2.28 Impact Factor
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    • "Further, some studies have suggested that host factors, including the immune response to alkyl hydroperoxide reductase, and interleukin 1 (IL-1) gene family polymorphism, et al., might mainly affect the clinical outcome of H. pylori infection [11– 13]. Our previous studies have demonstrated that H. pylori itself or its components elicited innate immune responses via toll-like receptor (TLR) 2 and TLR 4 on gastric epithelial cells and monocytes [14] [15]. Especially, IL-8 released from these cells is involved in the activation of neutrocytes and lymphocytes [13] [16]. "
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    ABSTRACT: Helicobacter pylori (H. pylori) infection is a definite causative factor for gastric ulcers (GUs). In the present study we detected a specific antigen of gastric epithelial cells (HGC-27) using cell ELISA, which was recognized by the sera of GU patients (n = 20) but not in patients with chronic gastritis (CG; n = 20) or in healthy volunteers (HC; n = 10). This antigen was over-expressed by a stressful (heat-stressed) environment, and was identified as elongation factor 2 kinase (EF-2K) by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes) from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1) and cytotoxic T lymphocyte (CTL) as opposed to those from CG patients. The target cells (HGC-27) expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU.
    Clinical and Developmental Immunology 02/2009; 2009(1740-2522):850623. DOI:10.1155/2009/850623 · 2.93 Impact Factor
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