TY - JOUR
T1 - Vacuolating cytotoxin and variants in Atg16L1 that disrupt autophagy promote helicobacter pylori infection in humans
AU - Raju, Deepa
AU - Hussey, Seamus
AU - Ang, Michelle
AU - Terebiznik, Mauricio R.
AU - Sibony, Michal
AU - Galindo-Mata, Esther
AU - Gupta, Vijay
AU - Blanke, Steven R.
AU - Delgado, Alberto
AU - Romero-Gallo, Judith
AU - Ramjeet, Mahendra Singh
AU - Mascarenhas, Heidi
AU - Peek, Richard M.
AU - Correa, Pelayo
AU - Streutker, Cathy
AU - Hold, Georgina
AU - Kunstmann, Erdmutte
AU - Yoshimori, Tamotsu
AU - Silverberg, Mark S.
AU - Girardin, Stephen E.
AU - Philpott, Dana J.
AU - El Omar, Emad
AU - Jones, Nicola L.
PY - 2012/5
Y1 - 2012/5
N2 - Background & Aims: The Helicobacter pylori toxin vacuolating cytotoxin (VacA) promotes gastric colonization, and its presence (VacA+) is associated with more-severe disease. The exact mechanisms by which VacA contributes to infection are unclear. We previously found that limited exposure to VacA induces autophagy of gastric cells, which eliminates the toxin; we investigated whether autophagy serves as a defense mechanism against H pylori infection. Methods: We investigated the effect of VacA on autophagy in human gastric epithelial cells and primary gastric cells from mice. Expression of p62, a marker of autophagy, was also assessed in gastric tissues from patients infected with toxigenic (VacA+) or nontoxigenic strains. We analyzed the effect of VacA on autophagy in peripheral blood monocytes obtained from subjects with different genotypes of ATG16L1, which regulates autophagy. We performed genotyping for ATG16L1 in 2 cohorts of infected and uninfected subjects. Results: Prolonged exposure of human gastric epithelial cells and mouse gastric cells to VacA disrupted induction of autophagy in response to the toxin, because the cells lacked cathepsin D in autophagosomes. Loss of autophagy resulted in the accumulation of p62 and reactive oxygen species. Gastric biopsy samples from patients infected with VacA+, but not nontoxigenic strains of H pylori, had increased levels of p62. Peripheral blood monocytes isolated from individuals with polymorphisms in ATG16L1 that increase susceptibility to Crohn's disease had reduced induction of autophagy in response to VacA+ compared to cells from individuals that did not have these polymorphisms. The presence of the ATG16L1 Crohn's disease risk variant increased susceptibility to H pylori infection in 2 separate cohorts. Conclusions: Autophagy protects against infection with H pylori; the toxin VacA disrupts autophagy to promote infection, which could contribute to inflammation and eventual carcinogenesis.
AB - Background & Aims: The Helicobacter pylori toxin vacuolating cytotoxin (VacA) promotes gastric colonization, and its presence (VacA+) is associated with more-severe disease. The exact mechanisms by which VacA contributes to infection are unclear. We previously found that limited exposure to VacA induces autophagy of gastric cells, which eliminates the toxin; we investigated whether autophagy serves as a defense mechanism against H pylori infection. Methods: We investigated the effect of VacA on autophagy in human gastric epithelial cells and primary gastric cells from mice. Expression of p62, a marker of autophagy, was also assessed in gastric tissues from patients infected with toxigenic (VacA+) or nontoxigenic strains. We analyzed the effect of VacA on autophagy in peripheral blood monocytes obtained from subjects with different genotypes of ATG16L1, which regulates autophagy. We performed genotyping for ATG16L1 in 2 cohorts of infected and uninfected subjects. Results: Prolonged exposure of human gastric epithelial cells and mouse gastric cells to VacA disrupted induction of autophagy in response to the toxin, because the cells lacked cathepsin D in autophagosomes. Loss of autophagy resulted in the accumulation of p62 and reactive oxygen species. Gastric biopsy samples from patients infected with VacA+, but not nontoxigenic strains of H pylori, had increased levels of p62. Peripheral blood monocytes isolated from individuals with polymorphisms in ATG16L1 that increase susceptibility to Crohn's disease had reduced induction of autophagy in response to VacA+ compared to cells from individuals that did not have these polymorphisms. The presence of the ATG16L1 Crohn's disease risk variant increased susceptibility to H pylori infection in 2 separate cohorts. Conclusions: Autophagy protects against infection with H pylori; the toxin VacA disrupts autophagy to promote infection, which could contribute to inflammation and eventual carcinogenesis.
KW - Bacteria Toxin
KW - Genetic
KW - Stomach Cancer
KW - Tumor
UR - http://www.scopus.com/inward/record.url?scp=84860223287&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860223287&partnerID=8YFLogxK
U2 - 10.1053/j.gastro.2012.01.043
DO - 10.1053/j.gastro.2012.01.043
M3 - Article
C2 - 22333951
AN - SCOPUS:84860223287
SN - 0016-5085
VL - 142
SP - 1160
EP - 1171
JO - Gastroenterology
JF - Gastroenterology
IS - 5
ER -