CagA EPIYA polymorphisms in Colombian Helicobacter pylori strains and their influence on disease-associated cellular responses

作     者：Carlos Alberto Fajardo Andrés Javier Quiroga Andrea Coronado Karen Labrador Nicole Acosta Pilar Delgado Carlos Jaramillo María Mercedes Bravo 

作者机构：Cancer and Infectious Agents Research Group National Cancer Institute Molecular Diagnostics and Bioinformatics Laboratory Biological Sciences Department Los Andes University 

出 版 物：《World Journal of Gastrointestinal Oncology》 (世界胃肠肿瘤学杂志（英文版）（电子版）)

年 卷 期：2013年第5卷第3期

页      面：50-59页

核心收录：

学科分类：1007[医学-药学(可授医学、理学学位)] 100705[医学-微生物与生化药学] 1001[医学-基础医学(可授医学、理学学位)] 100103[医学-病原生物学] 10[医学] 

基　　金：Supported by National Cancer Institute  Bogotá  Colombia Grant No. 41030310 to Bravo MM and Sciences Faculty  LosAndes University  Bogotá  Colombia 

主　　题：Helicobacter pylori cagA 3’region CagA protein Interleukin 8 Cell elongation Glu-Pro-Ile-Tyr-Ala 

摘      要：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 cellswere infected with each strain and assayed for translo-cation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked 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 phos-phorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gas-tritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P 0.02; 49.1% ± 23.1% vs 26.2%±14.8%, P0.045; 49.1% ± 23.1% vs 21.5% ± 19.5%, P0.043 and 49.1% ± 23.1% vs 29.5% ± 27.1%, P 0.047 respectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGS cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL,P 0.0001). We did not observe differences in the extent of cell