scholarly journals Transcriptional Analysis of Major Heat Shock Genes of Helicobacter pylori

2000 ◽  
Vol 182 (15) ◽  
pp. 4257-4263 ◽  
Author(s):  
Georg Homuth ◽  
Stephanie Domm ◽  
Diethelm Kleiner ◽  
Wolfgang Schumann
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Transcriptional Analysis ◽  
Transcriptional Level ◽  
Heat Shock Genes ◽  
Induction Kinetic ◽  
H Pylori ◽  
Bicistronic Mrna

ABSTRACT The transcriptional organization and heat inducibility of the major heat shock genes hrcA, dnaK, dnaJ,groEL, and htpG were analyzed on the transcriptional level in Helicobacter pylori strain 69A. The strongly heat-induced dnaK operon was found to be tricistronic, consisting of the genes hrcA,grpE, and dnaK. The dnaJ gene specified one monocistronic mRNA which was also heat inducible. The genes groES and groEL were transcribed as one strongly heat-inducible bicistronic mRNA which exhibited exactly the same induction kinetic as the dnaK operon. Surprisingly, transcription of the monocistronic htpG gene was switched off after heat shock. The data presented are discussed with regard to the different mechanisms regulating expression of heat shock genes inH. pylori

scholarly journals Effects ofHelicobacter pyloriand Heat Shock Protein 70 on the Proliferation of Human Gastric Epithelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Liping Tao ◽  
Hai Zou ◽  
Zhimin Huang
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Epithelial Cells ◽  
Heat Shock Protein ◽  
Mtt Assay ◽  
Heat Shock Protein 70 ◽  
Hsp70 Expression ◽  
Gastric Epithelial Cells ◽  
Ags Cells ◽  
H Pylori

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.

scholarly journals Transcriptional Phase Variation of a Type III Restriction-Modification System in Helicobacter pylori

2002 ◽  
Vol 184 (23) ◽  
pp. 6615-6623 ◽  
Author(s):  
Nicolette de Vries ◽  
Dirk Duinsbergen ◽  
Ernst J. Kuipers ◽  
Raymond G. J. Pot ◽  
Patricia Wiesenekker ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Phase Variation ◽  
Transcriptional Level ◽  
Length Variation ◽  
Phase Variable ◽  
Modification System ◽  
Type Iii ◽  
Restriction Modification System ◽  
H Pylori ◽  
Restriction Modification

ABSTRACT Phase variation is important in bacterial pathogenesis, since it generates antigenic variation for the evasion of immune responses and provides a strategy for quick adaptation to environmental changes. In this study, a Helicobacter pylori clone, designated MOD525, was identified that displayed phase-variable lacZ expression. The clone contained a transcriptional lacZ fusion in a putative type III DNA methyltransferase gene (mod, a homolog of the gene JHP1296 of strain J99), organized in an operon-like structure with a putative type III restriction endonuclease gene (res, a homolog of the gene JHP1297), located directly upstream of it. This putative type III restriction-modification system was common in H. pylori, as it was present in 15 out of 16 clinical isolates. Phase variation of the mod gene occurred at the transcriptional level both in clone MOD525 and in the parental H. pylori strain 1061. Further analysis showed that the res gene also displayed transcriptional phase variation and that it was cotranscribed with the mod gene. A homopolymeric cytosine tract (C tract) was present in the 5′ coding region of the res gene. Length variation of this C tract caused the res open reading frame (ORF) to shift in and out of frame, switching the res gene on and off at the translational level. Surprisingly, the presence of an intact res ORF was positively correlated with active transcription of the downstream mod gene. Moreover, the C tract was required for the occurrence of transcriptional phase variation. Our finding that translation and transcription are linked during phase variation through slipped-strand mispairing is new for H. pylori.

scholarly journals Antibody to Heat Shock Protein Can Be Used for Early Serological Monitoring of Helicobacter pylori Eradication Treatment

2000 ◽  
Vol 7 (4) ◽  
pp. 574-577 ◽  
Author(s):  
Naoko Yunoki ◽  
Kenji Yokota ◽  
Motowo Mizuno ◽  
Yoshiro Kawahara ◽  
Masayasu Adachi ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Antimicrobial Agents ◽  
Eradication Therapy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peptic Ulcers ◽  
Whole Cell ◽  
Humoral Immune ◽  
Whole Cell Lysate ◽  
H Pylori

ABSTRACT Infection with Helicobacter pylori induces humoral immune responses against various antigens of the bacterium. Heat shock proteins (hsps) are immunodominant antigens in various diseases including H. pylori infection. In the present study, we measured the anti-hsp antibody titers in 42 patients with H. pylori-infected peptic ulcers during a bacterial eradication study. The patients were treated with a proton pump inhibitor and antimicrobial agents to eradicate the organism. Their sera were obtained at pretreatment and at 1 month and 6 months after the eradication therapy. The titers of immunoglobulin G antibodies to theH. pylori hsp, whole-cell lysate, and urease (30-kDa subunit) antigens in serum were measured by a capture enzyme-linked immunosorbent assay. The levels of H. pylori hsp60 antibodies in sera collected 1 month after treatment had declined significantly, even when changes in the titers of antibodies to whole-cell and urease antigens were not apparent. These results suggest that measurement of antibodies to H. pylorihsp60 in serum is useful for the early monitoring of the effectiveness of eradication therapy.

scholarly journals Helicobacter pylori Induces RANTES through Activation of NF-κB

2003 ◽  
Vol 71 (7) ◽  
pp. 3748-3756 ◽  
Author(s):  
Naoki Mori ◽  
Alan M. Krensky ◽  
Romas Geleziunas ◽  
Akihiro Wada ◽  
Toshiya Hirayama ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Intracellular Signaling ◽  
Interleukin 1 ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Gastric Epithelial Cells ◽  
Rantes Promoter ◽  
H Pylori

ABSTRACT Helicobacter pylori-infected gastric mucosa displays a conspicuous infiltration of mononuclear cells and neutrophils. RANTES (short for “regulated upon activation, normal T cell expressed and secreted”) is a chemoattractant cytokine (chemokine) important in the infiltration of T lymphocytes and monocytes. RANTES may therefore contribute to the cellular infiltrate in the H. pylori-infected gastric mucosa. The aim of this study was to analyze the molecular mechanism responsible for H. pylori-mediated RANTES expression. We observed that gastric epithelial cells produced RANTES upon coculture with H. pylori. In addition, H. pylori induced RANTES mRNA expression and an increase in luciferase activity in cells which were transfected with a luciferase reporter construct derived from the RANTES promoter, in gastric epithelial cells, indicating that the induction of RANTES production occurred at the transcriptional level. Induction of RANTES was dependent on an intact cag pathogenicity island. Activation of the RANTES promoter by H. pylori occurred through the action of NF-κB. Transfection of kinase-deficient mutants of IκB kinase (IKK) and NF-κB-inducing kinase (NIK) inhibited H. pylori-mediated RANTES activation. In contrast, tumor necrosis factor alpha- or interleukin-1/Toll-like receptor signaling molecules—such as mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1, MyD88, and interleukin-1 receptor-associated kinase—did not play a role in RANTES activation by H. pylori. Collectively, H. pylori induced NF-κB activation through an intracellular signaling pathway that involved IKK and NIK, leading to RANTES gene transcription. RANTES induction by H. pylori may play an important role in gastric inflammation.

scholarly journals Dual Control of Helicobacter pylori Heat Shock Gene Transcription by HspR and HrcA

2004 ◽  
Vol 186 (10) ◽  
pp. 2956-2965 ◽  
Author(s):  
Gunther Spohn ◽  
Alberto Danielli ◽  
Davide Roncarati ◽  
Isabel Delany ◽  
Rino Rappuoli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Heat Shock ◽  
Heat Shock Gene ◽  
Inverted Repeats ◽  
Dual Control ◽  
Shock Gene ◽  
Heat Shock Gene Expression ◽  
H Pylori

ABSTRACT The HspR repressor regulates transcription of the groESL, hrcA-grpE-dnaK, and cbpA-hspR-orf operons of Helicobacter pylori. Here we show that two of the HspR-regulated operons, namely, the groESL and dnaK operons, encoding the major cellular chaperone machineries are also regulated by the H. pylori homologue of the HrcA repressor. Similarly to the hspR mutation, deletion of the hrcA gene also leads to complete derepression of the P gro and P hrc promoters. The presence of both HspR and HrcA is therefore necessary for regulated transcription from these promoters. HrcA binds directly to P gro and P hrc , likely contacting two inverted repeats with similarity to the CIRCE motif, which are present on both promoters. HrcA regulation is, however, shown to depend on binding of the HspR protein, since deletion of the HspR-binding site of the P gro promoter leads to loss of heat inducibility of this promoter. In contrast, transcription from the P cbp promoter is regulated solely by HspR. HspR is also shown to form oligomers in vivo through a stretch of hydrophobic repeats between amino acid positions 66 and 97. The implications of these findings for the elucidation of the networks regulating heat shock gene expression in H. pylori are discussed.

scholarly journals Identification of B-Cell Epitopes of HspA from Helicobacter pylori and Detection of Epitope Antibody Profiles in Naturally Infected Persons

Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 65
Author(s):  
Xin Zhang ◽  
Shuli Sang ◽  
Qing Guan ◽  
Haoxia Tao ◽  
Yanchun Wang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
B Cell ◽  
Protein A ◽  
Peptide Fragments ◽  
Nickel Ion ◽  
B Cell Epitopes ◽  
E Coli ◽  
Important Target ◽  
H Pylori

Helicobacter pylori (H. pylori), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni2+ is an important co-factor required for the maturation and enzymatic activity of H. pylori urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of H. pylori. In this work, HspA was truncated into five fragments to determine the location of an antigen immunodominant peptide. A series of overlapping, truncated 11-amino-acid peptides in immunodominant peptide fragments were synthesized chemically and screened by ELISA. The immunogenicity and antigenicity of the screened epitope peptides were verified by ELISA, Western blot, and lymphocyte proliferation tests. Two novel B-cell epitopes were identified, covering amino acids 2–31 of HspA, which are HP11 (2–12; KFQPLGERVLV) and HP19 (18–28; ENKTSSGIIIP). The antiserum obtained from HP11-KLH and HP19-KLH immunized mice can bind to naive HspA in H. pylori SS2000, rHspA expressed in E. coli, and the corresponding GST fusion peptide. Among HspA seropositive persons, the seropositive rates of HP11 and HP19 were 21.4% and 33.3%, respectively. Both of the B-cell epitopes of HspA are highly conserved epitopes with good antigenicity and immunogenicity.

scholarly journals CtsR Is the Master Regulator of Stress Response Gene Expression in Oenococcus oeni

2005 ◽  
Vol 187 (16) ◽  
pp. 5614-5623 ◽  
Author(s):  
Cosette Grandvalet ◽  
Françoise Coucheney ◽  
Charlotte Beltramo ◽  
Jean Guzzo
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Molecular Chaperone ◽  
Oenococcus Oeni ◽  
Transcriptional Level ◽  
Class Iii ◽  
Heat Shock Genes ◽  
Gram Positive ◽  
Stress Genes ◽  
Gram Positive Bacteria

ABSTRACT Although many stress response genes have been characterized in Oenococcus oeni, little is known about the regulation of stress response in this malolactic bacterium. The expression of eubacterial stress genes is controlled both positively and negatively at the transcriptional level. Overall, negative regulation of heat shock genes appears to be more widespread among gram-positive bacteria. We recently identified an ortholog of the ctsR gene in O. oeni. In Bacillus subtilis, CtsR negatively regulates expression of the clp genes, which belong to the class III family of heat shock genes. The ctsR gene of O. oeni is cotranscribed with the downstream clpC gene. Sequence analysis of the O. oeni IOB 8413 (ATCC BAA-1163) genome revealed the presence of potential CtsR operator sites upstream from most of the major molecular chaperone genes, including the clp genes and the groES and dnaK operons. Using B. subtilis as a heterologous host, CtsR-dependent regulation of O. oeni molecular chaperone genes was demonstrated with transcriptional fusions. No alternative sigma factors appear to be encoded by the O. oeni IOB 8413 (ATCC BAA-1163) genome. Moreover, apart from CtsR, no known genes encoding regulators of stress response, such as HrcA, could be identified in this genome. Unlike the multiple regulatory mechanisms of stress response described in many closely related gram-positive bacteria, this is the first example where dnaK and groESL are controlled by CtsR but not by HrcA.

scholarly journals Characterization of the HspR-Mediated Stress Response in Helicobacter pylori

2002 ◽  
Vol 184 (11) ◽  
pp. 2925-2930 ◽  
Author(s):  
Gunther Spohn ◽  
Isabel Delany ◽  
Rino Rappuoli ◽  
Vincenzo Scarlato
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Transcriptional Response ◽  
Temperature Shift ◽  
Environmental Stresses ◽  
Induction Phase ◽  
Similar Response ◽  
Shock Response ◽  
H Pylori

ABSTRACT The major heat shock genes of Helicobacter pylori are regulated by the HspR repressor. In the present study we characterize the transcriptional response of the three known HspR-dependent promoters P cbp , P gro , and P hrc to different environmental stresses. A temperature shift from 37 to 42°C causes a typical heat shock response at all three promoters characterized by an immediate and strong induction phase of transcription and a subsequent adaptation phase, which is specific for each promoter and whose onset is determined partially by the half-lives of the respective mRNAs. Exposure to high osmolarity induces a similar response on the P gro and P cbp promoters while no such response is detectable at the P hrc promoter. Puromycin treatment induces transcription from all three HspR-dependent promoters, indicating that different environmental stresses are intracellularly sensed by the regulatory machinery through the accumulation of nonnative proteins. The implications of these data for the regulatory network controlling the heat shock response in H. pylori are discussed.

scholarly journals The Helicobacter pylori HspR-Modulator CbpA Is a Multifunctional Heat-Shock Protein

2020 ◽  
Vol 8 (2) ◽  
pp. 251
Author(s):  
Simona Pepe ◽  
Vincenzo Scarlato ◽  
Davide Roncarati
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Functional Characterization ◽  
Direct Interaction ◽  
Binding Activity ◽  
Regulatory Role ◽  
Heat Shock Gene ◽  
Dna Binding Activity ◽  
H Pylori

The medically important human pathogen Helicobacter pylori relies on a collection of highly conserved heat-shock and chaperone proteins to preserve the integrity of cellular polypeptides and to control their homeostasis in response to external stress and changing environmental conditions. Among this set of chaperones, the CbpA protein has been shown to play a regulatory role in heat-shock gene regulation by directly interacting with the master stress-responsive repressor HspR. Apart from this regulatory role, little is known so far about CbpA functional activities. Using biochemistry and molecular biology approaches, we have started the in vitro functional characterization of H. pylori CbpA. Specifically, we show that CbpA is a multifunctional protein, being able to bind DNA and to stimulate the ATPase activity of the major chaperone DnaK. In addition, we report a preliminary observation suggesting that CbpA DNA-binding activity can be affected by the direct interaction with the heat-shock master repressor HspR, supporting the hypothesis of a reciprocal crosstalk between these two proteins. Thus, our work defines novel functions for H. pylori CbpA and stimulates further studies aimed at the comprehension of the complex regulatory interplay among chaperones and heat-shock transcriptional regulators.

Sign in / Sign up

Export Citation Format

Share Document