Intestinal organoids are a newly developed culture system for investigating pathogen-host interactions. Intestinal organoid models have been widely used since their development, because the results obtained from this type of culture model better represent physiological conditions than those from well-established cell lines. The three-dimensional (3D) porcine intestinal organoid model was reported in 2018 and 2019 for the investigation of intestinal pathogens. However, those organoid culture models were basal-out intestinal organoids, which are not suitable for porcine enteric virus research because they invade the intestines via the apical side of epithelial cells on villi. In this study, we developed a porcine apical-out intestinal organoid culture system and verified its infectivity, type I and type III interferon (IFN) antiviral responses, and inflammatory responses following infection by a swine enteric virus. Our results imply that this apical-out porcine intestinal organoid culture system is an ideal model for the investigation of interactions between swine enteric viruses and the intestines.

The intestinal epithelium is a physical barrier to enteric viruses and commensal bacteria. It plays an essential role in maintaining the balance between the host and intestinal microenvironment.