Helicobacter pylori vacuolating cytotoxin inhibits T lymphocyte activation.

Cloning and Expression of the Heterogenic Vacuolating Cytotoxin From an Iranian Helicobacter pylori Strain

Vacuolating Cytotoxin of Helicobacter pylori

Vacuolating cytotoxin (VacA) is one of the most important virulence factors of H. pylori (Hp), which isthe only toxic protein that is secreted from Hp cell into the culture supernatant. The effects of VacA oneukaryotic systems is the subject of many previous and on going research studies. Intracellular targetsfor this toxin include: late endosomal and lysosomal compartments, m...

In vitro cytotoxic effects of vacuolating cytotoxin produced by clinical isolates of Helicobacter pylori.

The vacuolating cytotoxin produced by Helicobacter pylori is considered to be one virulence factor causing peptic ulceration. In this study, we examined the activity of vacuolating cytotoxin in induction of intracellular vacuolation of rabbit gastric epithelial cells (RGECs). We used culture supernatants of H. pylori as a source of vacuolating cytotoxin and quantitated cytotoxic activity by the...

Natural diversity in the N terminus of the mature vacuolating cytotoxin of Helicobacter pylori determines cytotoxin activity.

Naturally occurring noncytotoxic vacA type s2 strains of Helicobacter pylori have a 12-residue extension to the vacuolating cytotoxin (VacA) compared with cytotoxic type s1 strains. We show that adding the region encoding this extension to type s1 vacA completely abolishes vacuolating cytotoxin activity but has no effect on VacA production.

Evolution of the Helicobacter pylori vacuolating cytotoxin in a human stomach.

We describe two subclones of Helicobacter pylori, isolated contemporaneously from a human stomach, which differ markedly in the vacuolating cytotoxin gene, vacA, but whose near identity in sequences outside this locus implies a very recent common origin. The differences are consistent with homologous recombination with DNA from another strain and result in a changed vacA midregion and, importan...