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.
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. The gastric antral mucosa was obtained from a total of 6 untreated patients undergoing gastroscopic and pathologic confirmation of chronic superficial gastritis. Three patients infected by H. pylori and 3 patients uninfected were used to cDNA microarray experiment.
Project description:This group is focusing on the molecular mechanisms of the biosynthesis of glycoconjugates and carbohydrate ligands important in the process of gastric carcinogenesis and on gastric carcinoma progression and metastasis. The adhesion of H. pylori to epithelial cells induces a variety of modifications, including changes in cell morphology,cytokine production and release, alterations in glycosylation and in the biosynthesis of mucins. This study aims to identify the gene expression changes in the gastric epithelial cells (AGS) induced by Helicobacter pylori infection. This experiment was performed as previously described in the literature by submitting a gastric cell line to co-culture with reference strains of H. pylori. Overall design: The following RNA samples (in triplicate) were analyzed by hybridization to the GLYCOv2 array: 1)Gastric cell line co-culture with H. pylori strain A(High Patogenicity) 2)Gastric cell line co-culture with H. pylori strain B(Low Patogenicity) 3)Gastric cell line without H. pylori co-culture (control)
Project description:Helicobacter pylori are gram-negative bacteria that colonize the human stomach and are the major etiological factor in gastric carcinoma development. The aim of this work was to evaluate changes in gene expression in gastric cells induced by H. pylori. The human gastric carcinoma-derived cell line AGS was infected with H. pylori strain 60190 (ATCC 49503) for 24 hours. RNA was extracted from three independent experiments.
Project description:This group is focusing on the molecular mechanisms of the biosynthesis of glycoconjugates and carbohydrate ligands important in the process of gastric carcinogenesis and on gastric carcinoma progression and metastasis. The adhesion of H. pylori to epithelial cells induces a variety of modifications, including changes in cell morphology,cytokine production and release, alterations in glycosylation and in the biosynthesis of mucins. This study aims to identify the gene expression changes in the gastric epithelial cells (AGS) induced by Helicobacter pylori infection. This experiment was performed as previously described in the literature by submitting a gastric cell line to co-culture with reference strains of H. pylori. The following RNA samples (in triplicate) were analyzed by hybridization to the GLYCOv2 array: 1)Gastric cell line co-culture with H. pylori strain A(High Patogenicity) 2)Gastric cell line co-culture with H. pylori strain B(Low Patogenicity) 3)Gastric cell line without H. pylori co-culture (control)
Project description:Thiele2005 - Genome-scale metabolic network
of Helicobacter pylori (iIT341)
This model is described in the article:
reconstruction of Helicobacter pylori (iIT341 GSM/GPR): an in
silico genome-scale characterization of single- and
Thiele I, Vo TD, Price ND, Palsson
J. Bacteriol. 2005 Aug; 187(16):
Helicobacter pylori is a human gastric pathogen infecting
almost half of the world population. Herein, we present an
updated version of the metabolic reconstruction of H. pylori
strain 26695 based on the revised genome annotation and new
experimental data. This reconstruction, iIT341 GSM/GPR,
represents a detailed review of the current literature about H.
pylori as it integrates biochemical and genomic data in a
comprehensive framework. In total, it accounts for 341
metabolic genes, 476 intracellular reactions, 78 exchange
reactions, and 485 metabolites. Novel features of iIT341
GSM/GPR include (i) gene-protein-reaction associations, (ii)
elementally and charge-balanced reactions, (iii) more accurate
descriptions of isoprenoid and lipopolysaccharide metabolism,
and (iv) quantitative assessments of the supporting data for
each reaction. This metabolic reconstruction was used to carry
out in silico deletion studies to identify essential and
conditionally essential genes in H. pylori. A total of 128
essential and 75 conditionally essential metabolic genes were
identified. Predicted growth phenotypes of single knockouts
were validated using published experimental data. In addition,
in silico double-deletion studies identified a total of 47
synthetic lethal mutants involving 67 different metabolic genes
in rich medium.
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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. Keywords: Identification of an ArsRS-Regulon Overall design: 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.
Project description:Macrophages are important cells involved in infections responses. They are mediators of gastritis in acute Helicobacter pylori (Hp) infection. After macrophages infection with Hp one of the most up-regulated protein is CD300E. To identify effects of CD300E activation in macrophages an agonistic antibody was used to activate CD300E and effects on gene expression were monitored. Overall design: A time serie experiment was performed to identify effects of CD300E activation. 23 samples were profiled. Macrophages monocytes derived using M-CSF for 6 days. They were cultured for 1 d in culture medium without M-CSF and then infected with Helicobacter pylori for 48h. After infection macrophages were treated with an antibody to activate CD300E for 3 hours (3 biological replicates), 6 hours (4 biological replicates) and 24 hours (4 biological replicates). As controls were used macrophages not treated with the activacting CD300E antibody: 3, 6, and 24 hours four biological replicates each.
Project description:Helicobacter pylori is a highly successful and important human pathogen that causes chronic gastritis, peptic ulcer diseases and gastric cancer. Innate immunity plays an important role of the primary defense against pathogens and epidemiological studies have suggested a role of toll-like receptor 1 (TLR1) in the risk of H. pylori acquisition. We performed microarray analysis of gastric mucosal biopsy specimens from H. pylori-positive and uninfected subjects; infection was associated with an ~15-fold up-regulation of TLR10 (p <0.001). Quantitative RT-PCR confirmed TLR10 mRNA levels were increased 3-fold in H. pylori-infection (p <0.001) and immunohistochemistory using anti-TLR10 polyclonal antibodies showed increased TLR10 expression in gastric epithelial cells of infected individuals. In vitro experiments where H. pylori was co-cultured with NCI-N87 gastric cells showed significant H. pylori-specific up-regulation of TLR10 mRNA levels and a correlation with TLR2 mRNA levels (R = 0.87, P <0.001). We compared combinations of TLRs for their ability to mediate NF-_B activation. NF-_B activation was increased following exposure to heat killed H. pylori or H. pylori-LPS only with the TLR2/TLR10 heterodimer. These findings suggest TLR10 is a functional receptor involved in the innate immune response to H. pylori infection and that TLR2/TLR10 heterodimer possibly functions in the recognition of H. pylori-LPS. Overall design: We have employed whole genome microarray expression profiling of gastric epithelium in H.pylori infection. We compare 1) Hp positive and negative group. 2) by gastritis grade 3) by countries.
Project description:Differential gene transcript amounts between Helicobacter pylori N6 (wild type strain) bacteria and isogenic tlpD mutant grown in liquid culture to similar O.D.600 (1.0; mid log) Overall design: Comparative analyses of transcript levels in N6 (wild type strain) and isogenic tlpD mutant comprising four arrays of three biological experiments (one including a dye swap); each array comprising two technical replicates for each gene