Development of an immunocompetent colon chip to model Crohn's Disease

About This Grant

PROJECT SUMMARY/ABSTRACT The goal of this proposal is to develop an ex vivo experimental platform to enable novel investigations into the roles of the intestinal lumenal and basal microenvironment on the origins of Crohn's Disease (CD). CD is a chronic, idiopathic inflammatory disease of the intestines whose incidence and prevalence are increasing in the U.S. and globally. The disease has a disproportionate impact on the health and well-being of CD patients as well as significant use of health care resources. CD is thought to result from a breakdown of immune tolerance due to a compromised mucus hydrogel and/or epithelial cell barrier function early in the disease, allowing the inappropriate ingress of lumenal microbiota and their metabolites into the basal tissue microenvironment. Prior experimental models of CD are limited by the use of non-human or tumor cells that do not reflect human intestinal physiology, organoid models that do not fully mimic tissue microarchitecture and cell organization, or monolayer systems on stiff surfaces that lead to stem/proliferative cell loss and altered differentiated cell properties. To resolve these limitations, an interdisciplinary collaboration with expertise in advanced bioengineered intestinal platforms, immunology, and clinical gastroenterology has been formed to construct a 3D intestinal platform incorporating primary intestinal and immune cells to support a microenvironment that correctly mimics the colon in health and Crohn’s disease. A physiologic patterned mucus hydrogel will act as a protective barrier and lubricating surface along the lumenal epithelial cell surface. A magnetic fecal surrogate comprised of cellulose and colonic bacteria will recreate the properties of colonic fecal material and its biophysical and biochemical interactions with the lumenal epithelial surface. Collectively these advances in tissue engineering of a humanized colon-on-chip will create an accurate biointerface to produce a powerful ex vivo system to investigate the complex interplay of the intestinal epithelium, mucus hydrogel, fecal microbes/biomatrix and immune cells in health and CD. As a cell source, the project will take advantage of an extensive biobank of over 1000 HLA-typed normal donors and CD patients comprised of paired primary intestinal immune cells and colonic epithelium established at the Benaroya Institute. These specimens will enable the use of autologous tissues to avoid the confounding effects of allogeneic immune reactions.