Helicobacter pylori
Ontology highlight
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PROVIDER: PRJDB10720 | ENA |
REPOSITORIES: ENA
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Project description:Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori-colonized individuals develop disease. We examined the ability of two H. pylori isolates to induce differential host responses in vivo or in vitro, and then used an H. pylori whole genome microarray to identify bacterial determinants related to pathogenesis. Gastric ulcer strain B128 induced more severe gastritis, proliferation, and apoptosis in gerbil mucosa than did duodenal ulcer strain G1.1, and gastric ulceration and atrophy occurred only in B128+ gerbils. In vitro, gerbil-passaged B128 derivatives significantly increased IL-8 secretion and apoptosis compared with G1.1 strains. DNA hybridization to the microarray identified several strain-specific differences in gene composition including a large deletion of the cag pathogenicity island in strain G1.1. Partial and complete disruption of the cag island in strain B128 attenuated induction of IL-8 in vitro and significantly decreased gastric inflammation in vivo. These results indicate that the ability of H. pylori to regulate epithelial cell responses related to inflammation depends on the presence of an intact cag pathogenicity island. Use of an H pylori whole genome microarray is an effective method to identify differences in gene content between H. pylori strains that induce distinct pathological outcomes in a rodent model of H. pylori infection. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
2005-08-16 | E-GEOD-3135 | biostudies-arrayexpress
Project description:Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori-colonized individuals develop disease. We examined the ability of two H. pylori isolates to induce differential host responses in vivo or in vitro, and then used an H. pylori whole genome microarray to identify bacterial determinants related to pathogenesis. Gastric ulcer strain B128 induced more severe gastritis, proliferation, and apoptosis in gerbil mucosa than did duodenal ulcer strain G1.1, and gastric ulceration and atrophy occurred only in B128+ gerbils. In vitro, gerbil-passaged B128 derivatives significantly increased IL-8 secretion and apoptosis compared with G1.1 strains. DNA hybridization to the microarray identified several strain-specific differences in gene composition including a large deletion of the cag pathogenicity island in strain G1.1. Partial and complete disruption of the cag island in strain B128 attenuated induction of IL-8 in vitro and significantly decreased gastric inflammation in vivo. These results indicate that the ability of H. pylori to regulate epithelial cell responses related to inflammation depends on the presence of an intact cag pathogenicity island. Use of an H pylori whole genome microarray is an effective method to identify differences in gene content between H. pylori strains that induce distinct pathological outcomes in a rodent model of H. pylori infection. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-08-16 | GSE3135 | GEO
Project description:Helicobacter pylori, a gastroenteric pathogen believed to have co-evolved with humans for 100.000 years, has a high genetic variability that motivates the study of different H. pylori populations and the diseases caused by them in order to find determinants for disease evolution. In this study we utilized both genomic and proteomic tools to compare a H. pylori strain (Nic25_A) from Nicaragua isolated from a patient with intestinal metaplasia with the P12 strain from Europe isolated from a patient with duodenal ulcer. Differences in the protein expression levels between the two strains were determined by both label-free quantification (MaxQuant) and labelling methods (tandem mass tags, TMT), utilizing a lipid-based protein immobilization (LPI™) technique to target surface protein peptides. Using the MaxQuant software, we found 52 proteins significantly differing between the two strains (up-or-down regulated by a factor of 1.5) and with TMT we were able to find 18 proteins with different expression levels between the strains. The P12 (duodenal ulcer) strain had higher expression of genes belonging to the cagPAI operon, while Nic25_A (intestinal metaplasia) had higher expression of the acid response regulator ArsR, as well as proteins regulated by ArsR; KatA, AmiE, and proteins involved in urease production. The results show that differences in protein expression can be detected by proteomic approaches in H. pylori strains of different pathogenicity, which might have implications for studies of disease progression.
2018-10-26 | PXD005074 | Pride
Project description:Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori-colonized individuals develop disease. We examined the ability of two H. pylori isolates to induce differential host responses in vivo or in vitro, and then used an H. pylori whole genome microarray to identify bacterial determinants related to pathogenesis. Gastric ulcer strain B128 induced more severe gastritis, proliferation, and apoptosis in gerbil mucosa than did duodenal ulcer strain G1.1, and gastric ulceration and atrophy occurred only in B128+ gerbils. In vitro, gerbil-passaged B128 derivatives significantly increased IL-8 secretion and apoptosis compared with G1.1 strains. DNA hybridization to the microarray identified several strain-specific differences in gene composition including a large deletion of the cag pathogenicity island in strain G1.1. Partial and complete disruption of the cag island in strain B128 attenuated induction of IL-8 in vitro and significantly decreased gastric inflammation in vivo. These results indicate that the ability of H. pylori to regulate epithelial cell responses related to inflammation depends on the presence of an intact cag pathogenicity island. Use of an H pylori whole genome microarray is an effective method to identify differences in gene content between H. pylori strains that induce distinct pathological outcomes in a rodent model of H. pylori infection.
2005-06-30 | E-SMDB-1587 | biostudies-arrayexpress
Project description:Infection with Helicobacter pylori strongly impacts global health by causing chronic gastritis, ulcer disease and gastric cancer. Although extensive research into the strong immune response against this persistently colonizing bacterium exists, the specific role of CD8+ T cells remains elusive. We comprehensively characterize gastric H. pylori-specific CD8+ T cell responses in mice and humans. We define CD8+ T cell populations bearing a tissue-resident memory (TRM) phenotype, which infiltrate the gastric mucosa shortly after infection and mediate pathogen control by executing antigen-specific effector properties. These induced CD8+ TRM cells show a skewed T cell receptor beta chain usage and are specific for CagA, the distinctive oncoprotein injected by H. pylori into host cells. As the infection progresses, we observe a loss of the TRM phenotype and replacement of CD8+ by CD4+ T cells, indicating a shift in the immune response during the chronic infection phase. Our results point towards a hitherto unknown role of CD8+ T cell response in this bacterial infection, which may have important clinical implications for treatment and vaccination strategies against H. pylori.
2022-12-17 | GSE216894 | GEO
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:Helicobacter pylori (H. pylori) is a type of pathogen in humans that has infected nearly half of the population worldwide. Infections with H. pylori are typically associated with chronic gastritis and may even lead to gastric and duodenal ulcers and stomach cancer. While the mechanisms behind persistent colonization by H. pylori and the development of gastritis associated with it remain unclear, it is generally believed that the gastric epithelial cells (GECs) modulated by H. pylori in the gastric mucosa play a crucial role. We extensively studied the global gene expression patterns in H. pylori-infected AGS cells, a line of gastric epithelial cells, and identified genes that show increased expression upon infection with H. pylori.
2024-11-25 | GSE282738 | GEO
Project description:Bacterium isolated from duodenal ulcer patient
| PRJNA9627 | ENA
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.
2015-06-01 | GSE60427 | GEO
Project description:Chronic infection of the human stomach with Helicobacter pylori leads to a variety of pathologic sequelae including peptic ulcer and gastric cancer, resulting in significant human morbidity and mortality. Several genes have been implicated in disease related to H. pylori infection including the vacuolating cytotoxin and the cag pathogenicity island. Other factors important for establishment and maintenance of infection include urease enzyme production, motility, iron uptake and stress response. We utilized a C57BL/6 mouse infection model to query a collection of 2400 transposon mutants in two different bacterial strain backgrounds for H. pylori genetic loci contributing to colonization of the stomach. Microarray based tracking of transposon mutants allowed us to monitor the behavior of transposon insertions in 758 different gene loci. Of the loci measured 223 (29%) had a predicted colonization defect. These include previously described H. pylori virulence genes, genes implicated in virulence in other pathogenic bacteria and 81 hypothetical proteins. We have retested 10 previously uncharacterized candidate colonization gene loci by making independent null alleles and confirmed their colonization phenotype using competition experiments and determination of the dose required for 50% infection. Of the genetic loci retested, 60% have strain specific colonization defects while 40% had phenotypes in both strain backgrounds for infection, highlighting the profound effect of H. pylori strain variation on the pathogenic potential of this organism. This SuperSeries is composed of the SubSeries listed below.
2006-12-15 | GSE6531 | GEO