Epithelial barrier disfunction and crypt hyperplasia are phenomena underlying celiac disease (CeD). Although the immune system is strongly implicated in CeD, the contribution of the intestinal epithelium to disease onset and its pathophysiology remains less well investigated (1). We have developed a human intestine-on-chip model to study the role of (epi)genetics and disease-associated stimulations on intestinal epithelial barrier function in CeD.
We generated human intestinal epithelial cells (IEC) from induced Pluripotent stem cells (iPSCs), derived from CeD patients and control. On our chips, these iPSC-IEC develop into villus-like folds encompassing various cell types representative of the small intestine that support barrier integrity (2,3). By comparing intestine-on-chips from CeD patients and control donors, we can investigate if barrier permeability and functionality are inherently different in CeD. We also generated biopsy-derived ASC-based intestine-on-chip models from the same individuals, providing the option to compare these with the iPSC-based models in an autologous fashion. The ASC-based barriers have been epigenetically primed by the inflammatory processes involved in CeD, while the iPSC-based models have not previously been exposed to these intestinal processes. Comparison of the two models enables characterization of intrinsic barrier permeability as a result of genetic background (iPSC-IECs) and epigenetic mechanisms (ASC-IECs) that modulate epithelial barrier function in CeD.
We mimic disease-specific conditions (crypt hyperplasia and barrier disruption) by stimulating the models with varying concentrations of IFN-γ, either alone or combined at a single, defined concentration together with TNF-α. Subsequently, cellular, epigenetic and transcriptional responses of epithelial cells will be assessed by immunofluorescence and (single cell) RNA- and ATAC-sequencing. Barrier functionality will be assessed by FITC-dextran and viability will be examined in each of the conditions.
In summary, our intestine-on-chip platform supports exploring both intrinsic and epigenetic influences on epithelial barrier function and experimental modelling of barrier disruption and crypt hyperplasia in CeD.