Development of bovine intestinal organoids as a model to study host-parasite interactions

Intestinal organoids are excellent models to decipher host-pathogen interactions and to date, have been differentiated from human, murine and porcine intestinal stem cells. However, intestinal organoids have not yet been established in the bovine system. We describe a novel method to derive bovine intestinal organoids in vitro. Bovine intestinal crypts were isolated from the ileum of calves by enzymatic digestion and mixed with Matrigel®. The crypt/Matrigel® mixture was plated in a 24 well plate with IntestiCult® growth medium containing three inhibitors. Crypts formed spheroid structures and differentiated into organoid structures following 6 days of culture. The three dimensional structure of bovine intestinal organoids was confirmed by whole mount imaging. Characterisation of the cell types within bovine intestinal organoids is currently underway using quantitative RT-PCR and immunofluorescence. Bovine intestinal organoids will be used to dissect the interaction between Cryptosporidium parasites and intestinal epithelial cells, which are the primary target of Cryptosporidium in vivo. Furthermore, the ability of Cryptosporidium parasites to cultivate within bovine intestinal organoids will be examined and if successful, would negate the use of animals to generate Cryptosporidium parasites.