A 3-D enteroid-based model to study T-cell and epithelial cell interaction.

The constant interaction between intestinal epithelial cells (IECs) and intraepithelial lymphocytes (IELs) is thought to regulate mucosal barrier function and immune responses against invading pathogens. IELs represent a heterogeneous population of mostly activated and antigen-experienced T cells, but the biological function of IELs and their relationship with IECs is still poorly understood. Here, we describe a method to study T-cell-epithelial cell interactions using a recently established long-term intestinal "enteroid" culture system. This system allowed the study of peripheral T cell survival, proliferation, differentiation and behavior during long-term co-cultures with crypt-derived 3-D enteroids. Peripheral T cells activated in the presence of enteroids acquire several features of IELs, including morphology, membrane markers and movement in the epithelial layer. This co-culture system may facilitate the investigation of complex interactions between intestinal epithelial cells and immune cells, particularly allowing long term-cultures and studies targeting specific pathways in IEC or immune cell compartments.