Dataset Information

The Crohn's disease: associated ATG16L1 variant and Salmonella invasion.

ABSTRACT:

Objective

A common genetic coding variant in the core autophagy gene ATG16L1 is associated with increased susceptibility to Crohn's disease (CD). The variant encodes an amino acid change in ATG16L1 such that the threonine at position 300 is substituted with an alanine (ATG16L1 T300A). How this variant contributes to increased risk of CD is not known, but studies with transfected cell lines and gene-targeted mice have demonstrated that ATG16L1 is required for autophagy, control of interleukin-1-β and autophagic clearance of intracellular microbes. In addition, studies with human cells expressing ATG16L1 T300A indicate that this variant reduces the autophagic clearance of intracellular microbes.

Design/results

We demonstrate, using somatically gene-targeted human cells that the ATG16L1 T300A variant confers protection from cellular invasion by Salmonella. In addition, we show that ATG16L1-deficient cells are resistant to bacterial invasion.

Conclusions

These results suggest that cellular expression of ATG16L1 facilitates bacterial invasion and that the CD-associated ATG16L1 T300A variant may confer protection from bacterial infection.

SUBMITTER: Messer JS

PROVIDER: S-EPMC3686164 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature

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Publications

The Crohn's disease: associated ATG16L1 variant and Salmonella invasion.

Messer Jeannette S JS Murphy Stephen F SF Logsdon Mark F MF Lodolce James P JP Grimm Wesley A WA Bartulis Sarah J SJ Vogel Tiphanie P TP Burn Melisa M Boone David L DL

BMJ open 20130620 6

<h4>Objective</h4>A common genetic coding variant in the core autophagy gene ATG16L1 is associated with increased susceptibility to Crohn's disease (CD). The variant encodes an amino acid change in ATG16L1 such that the threonine at position 300 is substituted with an alanine (ATG16L1 T300A). How this variant contributes to increased risk of CD is not known, but studies with transfected cell lines and gene-targeted mice have demonstrated that ATG16L1 is required for autophagy, control of interle ...[more]

PMID: 23794574

Similar Datasets

Project description:ObjectivesAutophagy-related 16-like 1 (ATG16L1) deficiency leads to impaired cellular autophagy and bacterial degradation as well as an altered cytokine production. The single-nucleotide polymorphism rs2241880 (T300A) is associated with an increased risk for Crohn's disease (CD). ATG16L1 polymorphisms could therefore have an impact on the risk of infectious complications and disease course in CD. We examined the impact of the T300A genotype on the antibacterial response toward a panel of pathogenic bacteria in vitro, as well as clinical infectious complications in vivo and the disease course in a Danish cohort of patients with CD.MethodsA total of 236 CD patients were genotyped for ATG16L1(T300A); their clinical records were reviewed, and microbial, radiological, and surgical data were scrutinized. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy controls and CD patients carrying the different ATG16L1 genotypes, and the production of tumor necrosis factor (TNF)-α and interleukin (IL)-1β was measured by enzyme-linked immunosorbent assay after stimulation with a panel of pathogenic bacteria of clinical relevance for the gastrointestinal tract, e.g., enteroinvasive Escherichia coli (EIEC), Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, or Mycobacterium avium paratuberculosis.ResultsFifty-seven healthy controls (15, 29, 13) and 236 patients with CD (50, 108, 78) were genotyped for the T300A ATG16L1 polymorphism (AA homozygous, GG homozygous risk variant, AG heterozygous variant, respectively). The median duration of disease was 128 months (range, 30-175). The cumulative follow-up of this cohort was 2,366 patient-years. ATG16L1 gene variations interfered with the production of IL-1β, which was significantly increased in PBMCs from GG patients in response to all tested bacteria, whereas the TNF-α production was decreased in PBMCs from GG patients stimulated with EIEC, L. monocytogenes, and S. typhimurium, but unaffected by the other bacteria tested. Moreover, the GG variant showed a nonsignificant increase in the risk of bowel resections (P=0.07) and postsurgical infections (P=0.08), whereas the risk of non-disease-related infections was unaffected by genotype in the observation period. In addition, patients with AA and AG variants had a higher frequency of complicated fistulizing disease (P=0.03) with an overall more aggravated disease course with an increased number of surgical procedures for fistulous disease from a median 6.5 operations (2.0 in GG patients; P=0.002). This risk was independent on disease phenotype (penetrating vs. non-penetrating) and immunomodulating medication.ConclusionsThe T300A variant in patients with CD strongly increases the risk for complicated fistulizing disease, and significantly affects antibacterial responses in vitro, but the latter effect seems to have a minor role for the infectious risk in CD.

Dataset Information

The Crohn's disease: associated ATG16L1 variant and Salmonella invasion.

Objective

Design/results

Conclusions

Publications

The Crohn's disease: associated ATG16L1 variant and Salmonella invasion.

Similar Datasets

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