Journal Article

Atg16L1 T300A variant decreases selective autophagy resulting in altered cytokine signaling and decreased antibacterial defense

Norman, Jason M., Horn, Heiko, Lassen, Kara G., Shamji, Alykhan F., Patel, Khushbu K., Villablanca, Eduardo J., Becker, Morgan L., Bhan, Atul K., Stappenbeck, Thaddeus S., Liu, Ta-Chiang, Jaffe, Jacob D., Daly, Mark J., Virgin, Herbert W., Fagbami, Lola, Mercer, Johnathan, Carr, Steven A., Peloquin, Joanna M., Xavier, Ramnik J., Conway, Kara L., Yilmaz, Omer H., Schreiber, Stuart L., Heath, Robert J., Kuballa, Petric, Becker, Christine E.

2014

Overview

A coding polymorphism (Thr300Ala) in the essential autophagy gene, autophagy related 16-like 1 (ATG16L1), confers increased risk for the development of Crohn disease, although the mechanisms by which single disease-associated polymorphisms contribute to pathogenesis have been difficult to dissect given that environmental factors likely influence disease initiation in these patients. Here we introduce a knock-in mouse model expressing the Atg16L1 T300A variant. Consistent with the human polymorphism, T300A knock-in mice do not develop spontaneous intestinal inflammation, but exhibit morphological defects in Paneth and goblet cells. Selective autophagy is reduced in multiple cell types from T300A knock-in mice compared with WT mice. The T300A polymorphism significantly increases caspase 3- and caspase 7-mediated cleavage of Atg16L1, resulting in lower levels of full-length Atg16Ll T300A protein. Moreover, Atg16L1 T300A is associated with decreased antibacterial autophagy and increased IL-1β production in primary cells and in vivo. Quantitative proteomics for protein interactors of ATG16L1 identified previously unknown nonoverlapping sets of proteins involved in ATG16L1dependent antibacterial autophagy or IL-1β production. These findings demonstrate how the T300A polymorphism leads to cell typeand pathway-specific disruptions of selective autophagy and suggest a mechanism by which this polymorphism contributes to disease.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: animal models / Animals / Antibacterials / Autophagy / Autophagy - genetics / Biological Sciences / Blotting, Western / Carrier Proteins - genetics / caspases / Chromatography, Liquid / Crohn disease / Crohn Disease - genetics / Crohn Disease - immunology / Cytokines / Environmental factors / Enzyme-Linked Immunosorbent Assay / Epithelial cells / Flow Cytometry / Gene Knock-In Techniques / genes / goblet cells / Goblet Cells - pathology / Goblets / HeLa cells / humans / inflammation / interleukin-1beta / Intestines / Mice / Morphology / Paneth Cells - pathology / Pathogenesis / patients / Polymorphism / Polymorphism, Single Nucleotide - genetics / primary productivity / Protein isoforms / Proteins / Proteomics / Real-Time Polymerase Chain Reaction / risk / Salmonella Infections - immunology / Secretion / Shigella / Stem cells / Tandem Mass Spectrometry