The interrelationship between cytotoxin-associated gene A (CagA), vacuolating cytotoxin (VacA), and Helicobacter pylori-related diseases was investigated in 155 H. pylori-infected patients. Four (7%) of 60 subjects had mixed cagA+ and cagA- H. pylori infections. The H. pylori isolates from 98.3% of 121 patients with anti-CagA antibodies were cagA+. The occurrence of cagA+ H. pylori among 76 pat...

For over a century, since the discovery by Roux and Yersin that sterile culture supernatants of Corynebacterium diphtheriae contained a potent toxin able to reproduce the lesions caused by diphtheria (1), most pathogenic bacteria have been considered to be microorganisms able to intoxicate local and distant tissues by secreting toxins in the ex-tracellular medium. Recently, it has been shown th...

Many Gram-negative pathogens harbor type IV secretion systems (T4SSs) that translocate bacterial virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen Helicobacter pylori strongly depends on a T4SS. This T4SS forms a needle-like pilus, and its assembly is accomplished by multiple protein-protein interactions and various pilus-associated factors th...

CagA seropositivity is an important risk factor for gastric adenocarcinoma and duodenal ulcer. However, CagA seropositivity is also found in Helicobacter pylori-seronegative subjects. Is CagA seropositivity in these subjects a sign of a past H. pylori infection, or does it represent a false-positive reaction? This study investigates the intensity of the CagA immune reaction and the variation in...

To expand our knowledge of Helicobacter pylori virulence mechanisms, we used iTRAQ (isobaric tagging reagents for relative and absolute quantification)-based proteomic analysis to investigate the effect of H. pylori on gastric AGS tissue culture cells. In particular, we were interested in finding out which effects of H. pylori were dependent on the cytotoxins CagA and VacA. Protein analysis was...

Many bacterial pathogens inject into host cells effector proteins that are substrates for host tyrosine kinases such as Src and Abl family kinases. Phosphorylated effectors eventually subvert host cell signaling, aiding disease development. In the case of the gastric pathogen Helicobacter pylori, which is a major risk factor for the development of gastric cancer, the only known effector protein...

Helicobacter pylori is a causative agent of gastritis and peptic ulcer. cagA(+) H. pylori strains are more virulent than cagA(-) strains and are associated with gastric carcinoma. The cagA gene product, CagA, is injected by the bacterium into gastric epithelial cells and subsequently undergoes tyrosine phosphorylation. The phosphorylated CagA specifically binds SHP-2 phosphatase, activates the ...

BACKGROUND Infection with cagA-positive, cagA EPIYA motif ABD type, and vacA s1, m1, and i1 genotype strains of Helicobacter pylori is associated with an exacerbated inflammatory response and increased risk of gastroduodenal diseases. However, it is unclear whether the prevalence and virulence factor genotypes found in Southeast Asia are similar to those in Western countries. Here, we examined ...

Tumour-derived CXCL8 facilitates the movement of myeloid-derived suppressor cells, which are able to restrain antitumour immune responses tumour microenvironment. Kruppel-like factor 4 (KLF4) is a potential in gastric cancer (GC). However, knowledge regarding correlations between KLF4 and GC limited. We use cellular molecular biological methods assess whether these two factors interact GC. Expr...

If cytotoxin-associated gene A (CagA) status affects the response rates of therapy, then it may be possible to predict Helicobacter pylori eradication rates. We aimed to evaluate the response to eradication treatment of H. pylori infection in CagA-positive and CagA-negative patients. A total of 184 patients (93 males, 91 females, mean age 42.6 +/- 12.8 years) with H. pylori-positive chronic gas...