CagA EPIYA polymorphisms in ColombianHelicobacter pyloristrains and their influence on disease-associated cellular responses

Abstract

AIM:To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori ) strains from Colombia on the host cell biology. METHODS:Eighty-four H. pylori -cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n = 17), atrophic gastritis (n = 17), duodenal ulcer (n = 16), intestinal metaplasia (n = 16) and gastric cancer (n = 18), were included. To determine the integrity of the cag pathogenicity island (cag PAI) we evaluated the presence of cagA , cagT , cagE , and cag10 genes by polymerase chain reaction. AGS gastric epithelial cells were infected with each strain and assayed for translocation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzymelinked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of "hummingbird" cells (> 15 µm) was determined. RESULTS:Overall 72% (60/84) of the strains were found to harbor a functional cag PAI. Levels of phosphorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gastritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49

Functional Cytotoxin Associated Gene A in Helicobacter pylori Strains and Its Association with Integrity of Cag-pathogenicity Island and Histopathological Changes of Gastric Tissue

“…The link between existence and higher expression levels of CagA and/or T4SS components with progression of gastric pathology and carcinogenesis was similarly depicted by Szkaradkiewicz A et al (51). While our finding and those presented by other studies strongly indicate that intact cagPAI in strains with higher CagA expression level are more virulent, the expression of CagA and intactness of cagPAI may be unrelated, since there are some reports that showed inconsistency between integrity of cagPAI and expression of cagA (52).…”

Study of the oipA genetic diversity and EPIYA motif patterns in cagA-positive Helicobacter pylori strains from Venezuelan patients with chronic gastritis

“…Granulocytic infiltration Lymphocytic infiltration Total (n ¼ 101) were given by Fajardo et al [39] to explain the lack of association between the levels of induction of cell elongation or IL-8 expression and number of EPIYA motifs. Previous studies of our group suggested a synergism between H. pylori virulence factors and host genetic variants of the pro-inflammatory cytokine IL-1 on the development of severe chronic gastritis in Venezuela [23,40].…”

The Suppressive Effects of Geniposide and Genipin on Helicobacter pylori Infections In Vitro and In Vivo

“…The translocation of cagA by the cag‐pathogenicity island (cag‐PAI)‐encoded type IV secretion system affects the phosphorylation of the Glu‐Pro‐Ile‐Tyr‐Ala (EPIYA) motifs and affects the induction of host cell pathogenesis, such as the induction of the nuclear factor (NF)‐κB activation, IL‐8 secretion, and carcinogenesis. IL‐8 is one of the major proinflammatory cytokines and plays an important role in the inflammatory response (Fajardo and others ). Recently, IL‐8 has been found to function as a proangiogenic or a carcinogenic factor (Wroblewski and others ).…”