We provide a cell-based model of the human gut epithelial barrier to analyze the impact of test substances and/or infectious agents on gut barrier integrity and function. Caco-2 cells (human epithelial cell line) and THP-1 cells (human monocytic cell line) are co-cultured in a transwell culture system that models the epithelial barrier (Caco-2 cells) and the underlying lamina propria with resident macrophages (THP-1 cells). After addition of test substances and/or infectious agents to the upper chamber of the transwell system ("gut lumen"), epithelial barrier integrity and function as well as transmigration of pathogens and the resulting immune response by epithelial cells and macrophages is analyzed using various approaches.
Fig.: Experimental setup and analytical endpoints of the in-vitro model for gut epithelial barrier and lamina propria. The expression of tissue markers (e.g. Occludin) in the Caco-2 cell monolayer is analyzed by immunofluorescence (IF) followed by quantification. An ultra-structural analysis can be obtained by transmission electron microscopy (TEM). The small arrow indicates a tight junction.