Helicobacter pylori (Hp) vacuolating cytotoxin VacA induces cellular vacuolation in epithelial cells. We found that VacA could efficiently block proliferation of T cells by inducing a G1/S cell cycle arrest. It interfered with the T cell receptor/interleukin-2 (IL-2) signaling pathway at the level of the Ca2+-calmodulin-dependent phosphatase calcineurin. Nuclear translocation of nuclear factor ...

The vacuolating cytotoxin (VacA) is a major virulence factor of Helicobacter pylori which is not yet well characterised and is difficult to obtain in large quantities. Here we describe the production of a monoclonal antibody that recognises the native but not the denatured form of VacA. The antibody can be efficiently used in affinity chromatography for one-step purification of large quantities...

Infection with Helicobacter pylori strains harboring determinants of pathogenicity may lead to a strong inflammatory response in gastric mucosa. In this work, we examined the frequency of the cagA, vacA and iceA genotypes in H. pylori strains isolated from Brazilian patients and correlated these with the clinical manifestations. H. pylori was isolated from 165 patients [30 with non-ulcer dyspep...

In its mature form, the VacA toxin of Helicobacter pylori is a 95-kDa protein which is released from the bacteria as a low-activity complex. This complex can be activated by low-pH treatment that parallels the activity of the toxin on target cells. VacA has been previously shown to insert itself into lipid membranes and to induce anion-selective channels in planar lipid bilayers. Binding of Vac...

Gastric cancer is a significant health problem in Asia. Although the prevalence of Helicobacter pylori infection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized that H. pylori virulence factors contribute to the differences. The status of cagA, vacA, jhp0562, and β-(1,3)galT(jhp0563) was examined ...

Background Helicobacter pylori (H. pylori) infection has been associated with gastritis, gastric ulcer, mucosa-associated lymphoid tissue lymphoma and gastric cancer. The prevalence of H. pylori virulence genes have been studied in different populations and from different sources of samples but their prevalence has not been studied in dental plaque in Jordanian people; therefore, the aim of thi...

background :   vaculating cytotoxic a ( vaca ) gene is one of the multiple helicobacter pylori genotypes that produce a cytotoxin protein (vaca).this gene is a major cause of chronic peptic ulcers and gastric cancer. the aim of this study was to determine the correlation between vaca gene with peptic ulcer disease (pud) and non-ulcer dyspepsia (nud).   methods :    this was a case control study...

The present report describes an analysis of two virulence genes of Helicobacter pylori. Parts of the cagA gene, as well as parts from the signal (s) and middle (m) regions of the mosaic vacA gene, were amplified with biotin-labelled PCR primers and the products were subsequently analyzed by a single-step reverse hybridization line probe assay (LiPA). This assay comprises a strip containing mult...

PURPOSE The purpose of this research was to analyze cagA and vacA genotypes status in H. pylori isolates and relationship with clinical outcomes. METHODS Gastric biopsy specimens were cultured for H. pylori isolation and cagA and vacA genes were detected in these isolates. Data were collected and the results were analyzed using χ2 and Fishers exact tests by SPSS software version. 16. RESULT...

The vacuolating toxin A (VacA) is one of the most important virulence factors in Helicobacter pylori-induced damage to human gastric epithelium. Using human gastric epithelial cells in culture and broth culture filtrate from a VacA-producing H. pylori strain, we studied 1) the delivery of VacA to cells, 2) the localization and fate of internalized toxin, and 3) the persistence of toxin inside t...