Helicobacter pylori G27
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ABSTRACT:
PROVIDER: PRJNA249072 | ENA |
REPOSITORIES: ENA
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Project description:Helicobacter pylori G27 Transcriptome or Gene expression
| PRJNA545152 | ENA
Project description:The human gastric pathogen Helicobacter pylori is extremely well adapted to the highly acidic conditions encountered in the stomach. The pronounced acid resistance of H. pylori relies mainly on the ammonia-producing enzyme urease, however, urease-independent mechanisms are likely to contribute to acid adaptation. Acid-responsive gene regulation is mediated at least in part by the ArsRS two-component system consisting of the essential OmpR-like response regulator ArsR and the non-essential cognate histidine kinase ArsS whose autophosphorylation is triggered in response to low pH. In this study by global transcriptional profiling of an ArsS-deficient H. pylori mutant grown at pH 5.0 we define the ArsR~P- dependent regulon consisting of 110 genes including the urease gene cluster, the genes encoding the aliphatic amidases AmiE and AmiF and the rocF gene encoding arginase. Transcriptome analyses were performed using a whole-genome microarray containing 1649 PCR products generated with specific primer pairs derived from the genome sequences of H. pylori 26695 (Tomb et al., 1997. The complete genome sequence of the gastric pathogen Helicobacter pylori. Nature 388:539-547) and J99 (Alm et al., 1999. Genomic-sequence comparison of two unrelated isolates of the human gastric pathogen Helicobacter pylori. Nature 397:176-180) which were spotted in duplicate. Microarrays were produced as described by Gressmann et al. (Gressmann et al., 2005. Gain and loss of multiple genes during the evolution of Helicobacter pylori. PLoS Genet 1(4):e43). To determine genes which are differentially expressed in the ArsS-deficient mutant G27/HP165::km at pH 5.0, cDNA was prepared from RNA extracted from H. pylori G27 and G27/HP165::km after exposing the bacteria for one hour to acidic pH. A total of eight RNA samples from two independent RNA preparations from strain G27 and G27/HP165::km, respectively, was used for cDNA labelling und hybridisation. Dye reversal colour swaps were performed as follows: One cDNA sample was generated using Cy3-dCTP and the other using Cy5-dCTP resulting in four labelled cDNAs per colour swap. Cy5-dCTP and Cy3-dCTP labelled cDNAs were combined and hybridized to the H. pylori microarray. The slides were scanned using ScanArray HT and analysed by using the ScanArray express software (Perkin Elmer). Spots were flagged and eliminated from analysis when the signal to background ratio was less then three or in obvious instances of high background or stray fluorescent signals. Median intensities of spots were background corrected and differences in dye bias were normalized by using the LOWESS algorithm (Yang et al., 2002. Normalization for cDNA microarray data: a robuste composite method addressing single and multiple slide systematic variation. Nucleic Acid Res. 30:e15). The signal ratios as measure of differential expression between the red and green channels were obtained from processed signal intensities. Ratios were further analysed with Microsoft Excel (Microsoft) and SAM software for statistic significance (Tusher et al., 2001. Significance analysis of microarrays applied to the ionizing radiation response. Proc. Natl. Acad. Sci. USA 98:5116-5121). To determine the significance of differential expression RNA was isolated from the H. pylori G27 wild-type grown in BHI broth (pH 5.0), and 20 µg of this RNA were labelled either with Cy3-dCTP or with Cy5-dCTP. The two cDNA probes generated were hybridized onto the same slide, and the data were analysed as mentioned above. Signal ratios < 0.5 and > 2.0 were analyzed further.
2010-07-01 | E-GEOD-4293 | biostudies-arrayexpress
Project description:Helicobacter pylori is a human gastric pathogen associated with gastric and duodenal ulcers as well as specific gastric cancers. It is well-evidenced that motility is essential for this pathogen to colonize human gastric tissues. We found that the H. pylori G27 HP0518 mutant showed greater motility than the parental strain, leading to increased cell adhesion and subsequent CagA translocation and NF-κB activation in AGS cells. This mutant expressed a higher molecular mass flagellin A (FlaA) than the parental wild-type strain and the complemented HP0518 mutant, which correlated with differences in motility. Deglycosylation assays indicated that the increased molecular mass of the FlaA protein expressed by the mutant was due to O-linked glycoside modifications. Electron micrographs demonstrated that expression of bundle-formed flagellin filaments in the HP0518 mutant was enhanced in comparison to the wild-type strain. Different degrees of FlaA glycosylation between H. pylori strains suggested that glycosylation could affect both virulence and persistence in vivo. In conclusion, HP0518 inactivation resulted in FlaA hyper-glycosylation leading to increased virulence and motility.
2010-12-22 | GSE14752 | GEO
Project description:Helicobacter pylori genome re-sequencing
| PRJNA545123 | ENA
Project description:Helicobacter pylori is a human gastric pathogen associated with gastric and duodenal ulcers as well as specific gastric cancers. It is well-evidenced that motility is essential for this pathogen to colonize human gastric tissues. We found that the H. pylori G27 HP0518 mutant showed greater motility than the parental strain, leading to increased cell adhesion and subsequent CagA translocation and NF-κB activation in AGS cells. This mutant expressed a higher molecular mass flagellin A (FlaA) than the parental wild-type strain and the complemented HP0518 mutant, which correlated with differences in motility. Deglycosylation assays indicated that the increased molecular mass of the FlaA protein expressed by the mutant was due to O-linked glycoside modifications. Electron micrographs demonstrated that expression of bundle-formed flagellin filaments in the HP0518 mutant was enhanced in comparison to the wild-type strain. Different degrees of FlaA glycosylation between H. pylori strains suggested that glycosylation could affect both virulence and persistence in vivo. In conclusion, HP0518 inactivation resulted in FlaA hyper-glycosylation leading to increased virulence and motility. Microarray experiments were carried out as two-color hybridizations with a color-swap dye-reversal setting to compensate Cy-dye specific effects and to ensure statistically relevant data.
2010-12-22 | E-GEOD-14752 | biostudies-arrayexpress
Project description:Helicobacter pylori (H. pylori) is a human pathogen that infects almost half of the world’s population. Infection with H. pylori is frequently associated with chronic gastritis and can even lead to gastric and duodenal ulcers and gastric cancer. Although the persistent colonization of H. pylori and the development of H. pylori-associated gastritis remain poorly understood, it is believed that, in gastric mucosa, the modulated gastric epithelial cells (GECs) by H. pylori are key contributors. We used microarrays to detail the global programme of gene expression in Helicobacter pylori infected-gastric epithelial cell line AGS cells and identified up-regulated genes induced by Helicobacter pylori infection.
2024-04-18 | GSE264263 | GEO
Project description:HspR role in Helicobacter pylori heat-shock response
| PRJNA414191 | ENA
Project description:Helicobacter pylori infection reprograms host gene expression and influences various cellular processes, which have been investigated by cDNA microarray in vitro culture cells and in vivo patients of the chronic abdominal complaint. In this study，the effects of H. pylori infection on host gene expression in the gastric antral mucosa of patients with chronic gastritis were examined.
2012-04-30 | GSE30042 | GEO
Project description:HspR and HrcA role in Helicobacter pylori heat-shock response
| PRJNA421261 | ENA
Project description:Helicobacter pylori causes chronic gastritis and avoids elimination by the immune system of the infected host. The commensal bacterium Lactobacillus acidophilus has been reported to exert beneficial effects as a supplement during H. pylori eradication therapy. In the present study, we applied whole genome microarray analysis to compare the immune response induced in murine bone marrow derived macrophages (BMDM) stimulated with L. acidophilus, H. pylori, or with both bacteria in combination Microarray expression profiling was performed to analyze stimulation of bone marrow derived macrophages with Helicobacter pylori 251, Lactobacillus acidophilus NCFM or Lactobacillus acidophilus NCFM co-stimulated with Helicobacter pylori 251 were analyzed 5 hours after infection.
2013-07-02 | E-GEOD-42622 | biostudies-arrayexpress