Disease-specific Helicobacter pylori virulence factors: the role of cagA, vacA, iceA, babA2 alone or in combination

2000 ◽  
pp. 37-42 ◽  
Author(s):  
Y. Yamaoka ◽  
D. Y. Graham
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Disease Specific

scholarly journals Whole-Genome Sequencing and Comparative Genomics of Three Helicobacter pylori Strains Isolated from the Stomach of a Patient with Adenocarcinoma

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 331
Author(s):  
Montserrat Palau ◽  
Núria Piqué ◽  
M. José Ramírez-Lázaro ◽  
Sergio Lario ◽  
Xavier Calvet ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Virulence Factors ◽  
Outer Membrane Proteins ◽  
Whole Genome ◽  
Flagellar Biosynthesis ◽  
H Pylori ◽  
Restriction Modification

Helicobacter pylori is a common pathogen associated with several severe digestive diseases. Although multiple virulence factors have been described, it is still unclear the role of virulence factors on H. pylori pathogenesis and disease progression. Whole genome sequencing could help to find genetic markers of virulence strains. In this work, we analyzed three complete genomes from isolates obtained at the same point in time from a stomach of a patient with adenocarcinoma, using multiple available bioinformatics tools. The genome analysis of the strains B508A-S1, B508A-T2A and B508A-T4 revealed that they were cagA, babA and sabB/hopO negative. The differences among the three genomes were mainly related to outer membrane proteins, methylases, restriction modification systems and flagellar biosynthesis proteins. The strain B508A-T2A was the only one presenting the genotype vacA s1, and had the most distinct genome as it exhibited fewer shared genes, higher number of unique genes, and more polymorphisms were found in this genome. With all the accumulated information, no significant differences were found among the isolates regarding virulence and origin of the isolates. Nevertheless, some B508A-T2A genome characteristics could be linked to the pathogenicity of H. pylori.

scholarly journals The Role of a Dipeptide Transporter in the Virulence of Human Pathogen, Helicobacter pylori

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaohong Xu ◽  
Junwei Chen ◽  
Xiaoxing Huang ◽  
Shunhang Feng ◽  
Xiaoyan Zhang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Outer Membrane Proteins ◽  
Wild Type ◽  
Ags Cells ◽  
Dipeptide Transporter ◽  
Adhesion Level ◽  
H Pylori ◽  
Substrate Binding Protein

Helicobacter pylori harbors a dipeptide (Dpp) transporter consisting of a substrate-binding protein (DppA), two permeases (DppB and C), and two ATPases (DppD and F). The Dpp transporter is responsible for the transportation of dipeptides and short peptides. We found that its expression is important for the growth of H. pylori. To understand the role of the Dpp transporter in the pathogenesis of H. pylori, the expression of virulence factors and H. pylori-induced IL-8 production were investigated in H. pylori wild-type and isogenic H. pylori Dpp transporter mutants. We found that expression of CagA was downregulated, while expression of type 4 secretion system (T4SS) components was upregulated in Dpp transporter mutants. The DppA mutant strain expressed higher levels of outer membrane proteins (OMPs), including BabA, HopZ, OipA, and SabA, and showed a higher adhesion level to gastric epithelial AGS cells compared with the H. pylori 26695 wild-type strain. After infection of AGS cells, H. pylori ΔdppA induced a higher level of NF-κB activation and IL-8 production compared with wild-type. These results suggested that in addition to supporting the growth of H. pylori, the Dpp transporter causes bacteria to alter the expression of virulence factors and reduces H. pylori-induced NF-κB activation and IL-8 production in gastric epithelial cells.

scholarly journals Role of the Helicobacter pylori virulence factors vacuolating cytotoxin, CagA, and urease in a mouse model of disease.

1995 ◽  
Vol 63 (10) ◽  
pp. 4154-4160 ◽  
Author(s):  
P Ghiara ◽  
M Marchetti ◽  
M J Blaser ◽  
M K Tummuru ◽  
T L Cover ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Mouse Model ◽  
Virulence Factors ◽  
Vacuolating Cytotoxin

scholarly journals Helicobacter pylori Stimulates Dendritic Cells To Induce Interleukin-17 Expression from CD4+ T Lymphocytes

2009 ◽  
Vol 78 (2) ◽  
pp. 845-853 ◽  
Author(s):  
Wafa Khamri ◽  
Marjorie M. Walker ◽  
Peter Clark ◽  
John C. Atherton ◽  
Mark R. Thursz ◽  
...  
Keyword(s):  
T Cells ◽  
Helicobacter Pylori ◽  
Dendritic Cells ◽  
Virulence Factors ◽  
Human Monocyte ◽  
Interleukin 17 ◽  
Th17 Response ◽  
H Pylori

ABSTRACT Helicobacter pylori is a human gastroduodenal pathogen that leads to active chronic inflammation characterized by T-cell responses biased toward a Th1 phenotype. It has been accepted that H. pylori infection induces a Th17 response. At mucosal sites, dendritic cells (DCs) have the capacity to induce effector T cells. Here, we evaluate the role of DCs in the H. pylori-induced interleukin-17 (IL-17) response. Immunohistochemistry and immunofluorescence were performed on human gastric mucosal biopsy samples and showed that myeloid DCs in H. pylori-infected patients colocalized with IL-23- and that IL-17-producing lymphocytes were present in H. pylori-infected antral biopsy samples. In parallel, human monocyte-derived DCs stimulated in vitro with live H. pylori cells produced significant levels of IL-23 in the absence of IL-12 release. The subsequent incubation of H. pylori-infected DCs with autologous CD4+ T cells led to gamma interferon (IFN-γ) and IL-17 expression. The inhibition of IL-1 and, to a lesser extent, IL-23 inhibited IL-17 production by T cells. Finally, isogenic H. pylori mutant strains not expressing major virulence factors were less effective in inducing IL-1 and IL-23 release by DCs and IL-17 release by T cells than parental strains. Altogether, we can conclude that DCs are potent inducers of IL-23/IL-17 expression following H. pylori stimulation. IL-1/IL-23 as well as H. pylori virulence factors seem to play an important role in mediating this response.

Epidemiology and role of Helicobacter pylori virulence factors in gastric cancer carcinogenesis

Apmis ◽  
2020 ◽  
Vol 128 (2) ◽  
pp. 150-161 ◽  
Author(s):  
Asif Sukri ◽  
Alfizah Hanafiah ◽  
Noraziah Mohamad Zin ◽  
Nik Ritza Kosai
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Virulence Factors

scholarly journals Role of polymorphisms in genes that encode cytokines and Helicobacter pylori virulence factors in gastric carcinogenesis

2018 ◽  
Vol 9 (5) ◽  
pp. 83-89 ◽  
Author(s):  
Breno Bittencourt de Brito ◽  
Filipe Antônio França da Silva ◽  
Fabrício Freire de Melo
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Gastric Carcinogenesis
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