Helicobacter pylori, the causative agent of gastritis and ulcer disease in humans, secretes a toxin called VacA (vacuolating cytotoxin) into culture supernatants. VacA was initially characterized and purified on the basis of its ability to induce the formation of intracellular vacuoles in tissue culture cells. H. pylori strains possessing different alleles of vacA differ in their ability to exp...

UNLABELLED Objective(s) : Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. MATERIALS AND METHODS The antigenic ...

AIMS To determine the relation among the cytotoxin associated gene (cagA) and vacuolating cytotoxin gene (vacA) status of Helicobacter pylori isolates, the associated clinical diseases, and the severity and pattern of chronic gastritis. METHODS Helicobacter pylori was cultured from gastric biopsies obtained from dyspeptic patients. DNA was extracted from the isolates and the cagA and vacA sta...

Pathogenic strains of Helicobacter pylori secrete a cytotoxin, VacA, that in the presence of weak bases, causes osmotic swelling of acidic intracellular compartments enriched in markers for late endosomes and lysosomes. The molecular mechanisms by which VacA causes this vacuolation remain largely unknown. At neutral pH, VacA is predominantly a water-soluble dodecamer formed by two apposing hexa...

The vacuolating cytotoxin VacA is a major virulence factor of Helicobacter pylori, a bacterium responsible for gastroduodenal ulcers and cancer. VacA associates with lipid rafts, is endocytosed, and reaches the late endocytic compartment where it induces vacuolation. We have investigated the endocytic and intracellular trafficking pathways used by VacA, in HeLa and gastric AGS cells. We report ...

The Helicobacter pylori toxin VacA causes vacuolar degeneration in mammalian cell lines in vitro and plays a key role in peptic ulcer disease. Two alleles, m1 and m2, of the mid-region of the vacA gene have been described, and the m2 cytotoxin always has been described as inactive in the in vitro HeLa cell assay. However, the m2 allele is associated with peptic ulcer and is prevalent in populat...

PURPOSE Helicobacter pylori infection by virulent strains is associated with gastric adenocarcinoma. We aimed to determine whether infection with virulent H. pylori preceded precancerous gastric hypochlorhydria and atrophy in gastric cancer relatives and quantify the extent of virulence factor evolution. EXPERIMENTAL DESIGN H. pylori strains from 51 Scottish gastric cancer relatives were char...

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 o...

Mosaicism in vacA alleles with two distinct families of vacA signal sequences (s1 and s2) and two distinct families of middle region alleles (m1 and m2) has been reported. Research suggests that the vacA s1 genotype is closely associated with duodenal ulcer disease and with high cytotoxin production. The aims of this study were to evaluate the role of vacA genotyping with respect to gastric inf...

Helicobacter pylori-produced cytotoxin VacA induces intracellular vacuolation. The VacA-induced vacuole is assumed to represent the pathological status of intracellular trafficking. The fusion mechanism of the endosomes requires the formation of a tight complex between the Q-SNAREs and the R-SNAREs. We recently reported that syntaxin 7, a family member of the Q-SNARE protein, is involved in Vac...