Inflammatory Bowel Disease (IBD) is caused by multiple genetic and environmental factors but the molecular mechanisms leading to chronic inflammation in the gut are largely not understood. Much of the heritable human risk for IBD, particularly in Crohn’s disease, can be mapped to defects in lysosomes, a cellular organelle responsible for bacterial degradation. Previous studies implicate defective lysosome in Paneth and dendritic cells as major liabilities for IBD, but understanding the lysosomes in these cell-types have been challenging due to studying rare organelles (<3% cell mass) within rare cell types (<5% cells).
To address this challenge, we propose to adopt a recently developed rapid lysosomal purification method called LysoIP, a technique that enables robust profiling of lysosomal proteins that are often below the detection threshold at the whole-cell level. Our hypothesis is that molecular defects in intestinal lysosomes underlie IBD pathology and that molecular identification of lysosomal contents will reveal mechanisms leading to chronic inflammation. To this end, we will use genetic mouse models that share similarities to human gut and purify lysosomes from multiple epithelial and immune subsets in the intestine. We anticipate that our dataset will be useful in providing a comprehensive understanding of lysosomes mediating gut health.
