Project description:To distinguish between Helicobacter pylori isolates that may cause greater disease in patients, we used whole genome expression profiling as a platform to study host-pathogen interactions and identify gene signatures associated with isolates from patients with higher cancer risk.
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 and Kx2 were also grown in cell media in the absence of cells. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) and non-progenitor gastric epithelial cells (npGECs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island. Keywords: other
Project description:To distinguish between Helicobacter pylori isolates that may cause greater disease in patients, we used whole genome expression profiling as a platform to study host-pathogen interactions and identify gene signatures associated with isolates from patients with higher cancer risk. Expression profiles were studied for 3 clinical isolates from a region of high gastric cancer incidence (PZ5056, PZ5080, PZ5086) in Colombia and 3 isolates from a region with low gastric cancer incidence in Colombia (PZ5004, PZ5024, PZ5026). Each experiment was done in triplicate by infecting monolayers of gastric epithelial cells for 1 hour with the isolates.
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
Project description:Helicobacter pylori (H.pylori) infection is an important factor in the occurrence of human gastric diseases, but its pathogenic mechanism is not clear. N6-methyladenosine (m6A) is the most prevalent reversible methylation modification in mammalian RNA and it plays a crucial role in controlling many biological processes. We used MeRIP-seq technology to sequence the GES-1 cells infected with Helicobacter pylori(H. pylori) for 48 h.
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island.
Project description:Background Gastric Helicobacter pylori colonization leads to iron deficiency anemia (IDA), especially in children and adolescents. However the pathogenesis is poorly understood. Objective We sought to identify specific H. pylori genes involved in IDA development, by comparing bacterial genome-wide expression profiling in patients affected or not. Methods H. pylori were isolated from four children with IDA and four from matched controls without IDA. Based on these isolates, cDNA microarrays under iron-replete or depleted conditions were systematically performed to compare gene expression profiles at the whole genome level. Real-time reverse-transcription (RT-) PCR and protein assays were performed for further assessing the profile differentiation of the identified H. pylori IDA-associated genes. Results We identified 29 and 11 genes with significantly higher or lower expression in the IDA isolates compared to non-IDA isolates, respectively. Especially notable were higher expression of sabA gene encoding sialic acid-binding adhesin in the IDA isolates, which was confirmed by real-time RT-PCR study. Moreover, iron-depletion in vitro led to up-regulation of fecA1 and frpB1 genes and down-regulation of pfr, as predicted. Known iron-regulated genes such as fur, pfr, fecA, and feoB did not significantly differ between both groups. The IDA isolates had significantly higher expression of vacuolating cytotoxin gene vacA than non-IDA isolates, consistent with the results of VacA protein assays. There were no significant differences in bacterial growth value between IDA and non-IDA isolates. Conclusions It is likely that H. pylori carrying high expression of sabA causes IDA, especially in children and adolescents who have increased daily iron demand. In addition, it is possible that several host-interactive genes, including vacA, may play a synergistic role for sabA in IDA development.