H. pylori genotypes and host gene expression profiles
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE6143 | GEO | 2008/05/01
SECONDARY ACCESSION(S): PRJNA97677
REPOSITORIES: GEO
Similar Datasets
Project description:H. pylori virulence factors have been suggested to be important in determining the outcome of infection. The H. pylori adhesion protein BabA2 is thought to play an crucial role in bacterial colonization and in induction of a severe gastric inflammation, particularly in combination with expression of CagA and VacA. However, the influence of these virulence factors on the pathogenesis of H. pylori infection, is still poorly understood. To address this question, the inflammatory gene expression profiles from two groups of patients infected with triple-negative strains (lacking expression of CagA, BabA2 and VacAs1, but expressing VacAs2) and triple-positive strains (expressing CagA, VacAs1 and BabA2, but lacking expression of VacAs2) were investigated. The gene expression pattern in the antrum gastric mucosa from patients infected with different H. pylori strains was very similar, and no differentially expressed genes could be identified by pair-wise comparisons. Our data thus suggest a lack of correlation between the host inflammatory responses in the gastric mucosa and expression of the BabA2, CagA and VacAs1 genes. Two groups of patients who infected with double-positive strains (type I strains, expressing CagA and VacAs1 genes) and triple-negative strains (lacking the CagA, BabA2 and VacAs1, but expressing VacAs2) were investigated in this study.
2008-05-01 | E-GEOD-6143 | biostudies-arrayexpress
Project description:Background: Helicobacter pylori has been shown to alter the secretion of gastric hormones that modulate body fat deposition. Since cag-positive H. pylori strains interact intimately with the host gastric epithelial cells and trigger higher inflammation than cag-negative strains, we hypothesized that gastric colonization with H. pylori strains without functional cagA ameliorates obesity and its complications by modulating gastric gene expression and inflammation. Methodology/Principal Findings: To test this hypothesis we examined the effects of gastric colonization on metabolic and inflammatory markers in mice infected with two isogenic strains of H. pylori: 26695 strain 98-325 (cagA+ wild-type) and its cag pathogenicity island (cagPAI) mutant strain 99-305, a knockout made by inserting a chloramphenicol resistance cassette. Only the cagPAI mutant decreased fasting blood glucose levels, improved glucose tolerance and suppressed weight gain in db/db mice and mice with diet-induced obesity. These effects were associated with increased gastric leptin levels, suppressed infiltration of macrophages, enhanced influx of regulatory T cells (Treg) in adipose tissue and suppressed gastric inflammation. Gene set enrichment analyses of gastric mucosal samples identified six differentially modulated pathways, including the Hedgehog signaling pathway that is associated with control of cellular proliferation and gastric carcinogenesis as well as the insulin signaling pathway. Conclusions/Significance: Gastric colonization with cagPAI-negative strains of H. pylori ameliorate obesity and inflammation by modulating gastric gene expression, suggesting that cag-negative H. pylori strains might be beneficial in ameliorating obesity and its co-morbidities. Gastric mucosa from three groups of mice: uninfected, infected with H. pylori 26695 strain 98-325 (cagA+ wild-type) or infected with H. pylori mutant strain 99-305 (lacking cag pathogenicity island; cagA-)
2010-11-13 | E-GEOD-21833 | biostudies-arrayexpress
Project description:Background: Helicobacter pylori is an important human pathogen that infects the human gastric mucosa leading to chronic inflammation which is responsible for severe gastroduodenal diseases. The Outer Inflammatory Protein A (OipA) of H. pylori is an important virulence factor. However, the role of OipA in gastric cancer and ulcer development is still not well-established. Phase variation within a CT dinucleotide repeat motif of oipA switches its expression “on” and “off”. This study aims to elucidate the role of OipA in H. pylori infection using oipA “on” and “off” clinical strains and oipA deletion mutant. Methods: Proteomics analysis was performed on AGS human gastric epithelial cell line post-infection with oipA “on” and “off” H. pylori using liquid chromatography / mass spectrometry (LC/MS). In addition, AGS apoptosis and cell cycle assays were performed. To confirm the findings, oipA deletion mutant (ΔoipA) was generated and expression of VacA was detected using Western blotting. Result: Expression of AGS proteins involve in human disease was suppressed / down-regulated post-infection with oipA “off” strains, as well as oipA mutant, compared to oipA “on” strains. Furthermore, oipA “off” strains and oipA mutant resulted in a higher level of apoptosis and G0/G1 cell-cycle arrest in AGS cells than oipA “on” strains. Interestingly, deletion of oipA was found to increase VacA production by the bacterium. Discussion: The capability of oipA “off” strains to induce apoptosis and suppress proteins having roles in human disease may suggest that these H. pylori may be less virulent or may even be protective against carcinogenesis compared to its oipA “on” counterparts. This may potentially explain the higher incidence of gastric cancer among East Asian which oipA “on” strains predominates. Conclusions: Data from this study strengthened our understanding of the role of H. pylori OipA as a virulence factor in chronic inflammation, metastasis and carcinogenesis.
2022-03-14 | PXD005020 | Pride
Project description:Helicobacter pylori (H. pylori) infection is associated with an inflammatory response in the gastric mucosa, ultimately leading to cellular hyperproliferation and malignant transformation. Hitherto, only expression of a single gene, or a limited number of genes, has been investigated in infected patients. Thus, the impact of H. pylori on the expression of a broad set of genes has not yet been analyzed. cDNA arrays were therefore used to establish the global pattern of gene expression in gastric tissue of healthy subjects and of H. pylori infected patients. Two main gene expression profiles were identified based on cluster analysis. The data obtained suggest a strong involvement of selected Toll-like receptors (TLRs)3, adhesion molecules, chemokines, and interleukins in the mucosal response. This pattern is clearly different from that observed using gastric epithelial cell lines infected in vitro with H. pylori. The genotype of the bacteria (presence of genes encoding CagA, VacA and BabA) was analyzed by PCR and shown to be associated with different expression profiles. The presence of a Keywords = H. pylori Keywords = gastric inflammation Keywords = cytokines Keywords: parallel sample
2004-01-07 | GSE581 | GEO
Project description:TC1: gastric epithelial (AGS) cells infected with wild type H. pylori (G27) and isogenic mutants in cagA and vacA for 0, 0.5, 3, 6, and 12 hours. Total RNA was used to make single stranded Cy5 labelled probe and compared to Cy3 labelled probe from uninfected AGS cells. Hybridizations of G27 (trial 4) and cagA- (trial 3) timecourses were done in parallel. A technical replicate of the G27 time course (trial 5) and hybridization of vacA- (trial 3) time course were done in parallel. The cagA 6 and 12 hour time points were technically replicated (trial 4) (the cagA 6 hour sample of trial 3 was lost). TC2: Biological replication and expansion of TC1, using more isogenic mutants and timepoints. AGS cells were mock infected, infected with G27, and isogenic mutants in cagN, cagA, cagE, and a deletion of the cag PAI for 0. 1, 3, 6, 12, and 24 hours. Probe synthesis and hybridization was done as in TC1. Note: there may have been a sample mix-up with PAI 12, swapping it with G27 or cagN 12.
2005-09-30 | E-SMDB-1661 | biostudies-arrayexpress
Project description:The proteins from the Fanconi Anemia (FA) pathway of DNA repair maintain DNA replication fork integrity by preventing the unscheduled degradation of nascent DNA at regions of stalled replication forks. Here, we ask if the bacterial pathogen H. pylori exploits the fork stabilisation machinery to generate double stand breaks (DSBs) and genomic instability. Specifically, we study if the H. pylori virulence factor CagA generates host genomic DSBs through replication fork destabilisation and collapse. An inducible gastric cancer model was used to examine global CagA-dependent transcriptomic and proteomic alterations, using RNA sequencing and SILAC-based mass spectrometry, respectively. The transcriptional alterations were confirmed in gastric cancer cell lines infected with H. pylori. Functional analysis was performed using chromatin fractionation, pulsed-field gel electrophoresis (PFGE), and single molecule DNA replication/repair fiber assays. We found a core set of 31 DNA repair factors including the FA genes FANCI, FANCD2, BRCA1, and BRCA2 that were downregulated following CagA expression. H. pylori infection of gastric cancer cell lines showed downregulation of the aforementioned FA genes in a CagA-dependent manner. Consistent with FA pathway downregulation, chromatin purification studies revealed impaired levels of Rad51 but higher recruitment of the nuclease MRE11 on the chromatin of CagA-expressing cells, suggesting impaired fork protection. In line with the above data, fibre assays revealed higher fork degradation, lower fork speed, daughter strands gap accumulation, and impaired re-start of replication forks in the presence of CagA, indicating compromised genome stability. By downregulating the expression of key DNA repair genes such as FANCI, FANCD2, BRCA1, and BRCA2, H. pylori CagA compromises host replication fork stability and induces DNA DSBs through fork collapse. These data unveil an intriguing example of a bacterial virulence factor that induces genomic instability by interfering with the host replication fork stabilisation machinery.
2022-02-22 | PXD031168 | Pride
Project description:Background: Helicobacter pylori has been shown to alter the secretion of gastric hormones that modulate body fat deposition. Since cag-positive H. pylori strains interact intimately with the host gastric epithelial cells and trigger higher inflammation than cag-negative strains, we hypothesized that gastric colonization with H. pylori strains without functional cagA ameliorates obesity and its complications by modulating gastric gene expression and inflammation. Methodology/Principal Findings: To test this hypothesis we examined the effects of gastric colonization on metabolic and inflammatory markers in mice infected with two isogenic strains of H. pylori: 26695 strain 98-325 (cagA+ wild-type) and its cag pathogenicity island (cagPAI) mutant strain 99-305, a knockout made by inserting a chloramphenicol resistance cassette. Only the cagPAI mutant decreased fasting blood glucose levels, improved glucose tolerance and suppressed weight gain in db/db mice and mice with diet-induced obesity. These effects were associated with increased gastric leptin levels, suppressed infiltration of macrophages, enhanced influx of regulatory T cells (Treg) in adipose tissue and suppressed gastric inflammation. Gene set enrichment analyses of gastric mucosal samples identified six differentially modulated pathways, including the Hedgehog signaling pathway that is associated with control of cellular proliferation and gastric carcinogenesis as well as the insulin signaling pathway. Conclusions/Significance: Gastric colonization with cagPAI-negative strains of H. pylori ameliorate obesity and inflammation by modulating gastric gene expression, suggesting that cag-negative H. pylori strains might be beneficial in ameliorating obesity and its co-morbidities.
2010-11-13 | GSE21833 | GEO
Project description:TC1: gastric epithelial (AGS) cells infected with wild type H. pylori (G27) and isogenic mutants in cagA and vacA for 0, 0.5, 3, 6, and 12 hours. Total RNA was used to make single stranded Cy5 labelled probe and compared to Cy3 labelled probe from uninfected AGS cells. Hybridizations of G27 (trial 4) and cagA- (trial 3) timecourses were done in parallel. A technical replicate of the G27 time course (trial 5) and hybridization of vacA- (trial 3) time course were done in parallel. The cagA 6 and 12 hour time points were technically replicated (trial 4) (the cagA 6 hour sample of trial 3 was lost). TC2: Biological replication and expansion of TC1, using more isogenic mutants and timepoints. AGS cells were mock infected, infected with G27, and isogenic mutants in cagN, cagA, cagE, and a deletion of the cag PAI for 0. 1, 3, 6, 12, and 24 hours. Probe synthesis and hybridization was done as in TC1. Note: there may have been a sample mix-up with PAI 12, swapping it with G27 or cagN 12. Groups of assays that are related as part of a time series. Computed
2005-11-03 | E-GEOD-3556 | biostudies-arrayexpress
Project description:Helicobacter pylori is a widespread Gram-negative pathogen involved in a variety of gastrointestinal diseases, including gastritis, ulceration, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancer. Immune responses aimed at eradication of H. pylori often prove futile, and paradoxically play a crucial role in the degeneration of epithelial integrity and disease progression. We have previously shown that H. pylori infection of primary human monocytes increases their potential to respond to subsequent bacterial stimuli – a process that may be involved in the generation of exaggerated, yet ineffective immune responses directed against the pathogen. In this study, we show that H. pylori-induced monocyte priming is not a common feature of Gram-negative bacteria, as Acinetobacter lwoffii induces tolerance to subsequent Escherichia coli lipopolysaccharide (LPS) challenge. Although the increased reactivity of H. pylori-infected monocytes seems to be specific to H. pylori, it appears to be independent of its virulence factors Cag pathogenicity island (CagPAI), cytotoxin associated gene A (CagA), vacuolating toxin A (VacA) and g-glutamyl transferase (g-GT). Utilizing whole-cell proteomics complemented with biochemical signaling studies, we show that H. pylori infection of monocytes induces a unique proteomic signature compared to other pro-inflammatory priming stimuli, namely LPS and the pathobiont A. lwoffii. Contrary to these tolerance- inducing stimuli, H. pylori priming leads to accumulation of NF-кB proteins, including p65/RelA, and thus to the acquisition of a monocyte phenotype more responsive to subsequent LPS challenge. The plasticity of pro-inflammatory responses based on abundance and availability of intracellular signaling molecules may be a heretofore underappreciated form of regulating innate immune memory as well as a novel facet of the pathobiology induced by H. pylori
2023-11-10 | PXD045072 | Pride
Project description:TC1: gastric epithelial (AGS) cells infected with wild type H. pylori (G27) and isogenic mutants in cagA and vacA for 0, 0.5, 3, 6, and 12 hours. Total RNA was used to make single stranded Cy5 labelled probe and compared to Cy3 labelled probe from uninfected AGS cells. Hybridizations of G27 (trial 4) and cagA- (trial 3) timecourses were done in parallel. A technical replicate of the G27 time course (trial 5) and hybridization of vacA- (trial 3) time course were done in parallel. The cagA 6 and 12 hour time points were technically replicated (trial 4) (the cagA 6 hour sample of trial 3 was lost). TC2: Biological replication and expansion of TC1, using more isogenic mutants and timepoints. AGS cells were mock infected, infected with G27, and isogenic mutants in cagN, cagA, cagE, and a deletion of the cag PAI for 0. 1, 3, 6, 12, and 24 hours. Probe synthesis and hybridization was done as in TC1. Note: there may have been a sample mix-up with PAI 12, swapping it with G27 or cagN 12. Groups of assays that are related as part of a time series. Keywords: time_series_design
2005-11-04 | GSE3556 | GEO