Novel intestinal organoid-derived monolayers to model celiac epithelium in vitro.

RAHMANI S; GALIPEAU HJ; SU HM; CHIRDO F.G; DIDAR TF; VERDU E

Banff

Congreso; Canadian Digestive Diseases Week (CDDW). March 1-3, 2019; 2019

Canadian Gastroenterology Society

Celiac-Prone Epithelium in vitroRahmani S, Galipeau HJ, SU HM, Chirdo F, Didar TF, Verdu EFBackground: The role intestinal epithelial cells (IECs) play in the breakdown of tolerance to gluten at an early stage in celiac disease (CeD) is unclear. Epithelial stress is a feature of CeD, and although the triggers are largely unknown, it is accompanied by expression of several markers that could be involved in initiation of inflammatory responses. IECs have been shown to express MHC class II (MHC-II) molecules and participate in antigen presentation in several models (I am not sure that this was demonstrated in several models). Whether IECs can participate in gluten peptide presentation, the major environmental trigger in celiac disease, is unknown. To study this, a model expressing human MHC-II, HLA DQ8 or DQ2, would be required.Aims: To develop organoid monolayers from transgenic mice expressing human celiac risk genes: HLA-DQ8 and HLA-DQ2. To investigate conditions leading to the induction of epithelial MHC-II and its co-stimulatory molecules, CD80, CD86 and CD40, that could enable early gluten peptide presentation.Methods: In order to show pathophysiological significance of the model, we used two approaches, either induction of inflammation in vivo through gluten sensitization, or by direct stimulation of the monolayers using pro-inflammatory cytokines relevant in CeD, such as IFN𝜸. Mice were sensitized with Pepsin-Trypsin (PT) digested gliadin and cholera toxin (CT) once a week for 3 weeks, followed by a challenge phase in which they only received gliadin, one of the main proteins in gluten. Control mice received CT only. We then developed organoid monolayers from the duodenum followed by stimulation with 10 ng/ml IFN𝜸. Then, markers necessary for gluten peptide presentation, the expression of MHC-II and their co-stimulatory molecules, were evaluated using flow cytometry. Results: We found that both in vivo gluten sensitization and in vitro stimulation of the organoid derived monolayer with IFN𝜸 induced a proinflammatory response, that independently primed the epithelium to express MHC-II molecules (p 0.02 and