Restore with Extracellular vesicles the Function of the Intestinal Tract Project acronym: REFIT

The goal of our consortium is to restore or maintain the barrier function, immunity and/or microbiome of the intestinal tract (gut) using extracellular vesicles isolated from cow milk. These extracellular vesicles are nano-sized particles released by cells and found in all body fluids, including milk. It was recently recognized that these vesicles contain many signaling molecules and as such play an important role in the cell-to-cell communication and are often found to be bioactive cross-species.  

In the general population worldwide, every 1 out of 7 men and 1 : 4 women have gastric and intestinal complaints, in total 2 million people in the Netherlands. Inflammatory bowel diseases (IBD; ulcerative colitis (UC) and Crohn’s disease (CD)) has become a global burden with a prevalence that surpasses 0.3%.  

The REFIT consortium includes three partners. At the Radboudumc, we will develop a large-scale isolation method for cow-milk extracellular vesicles (mEVs) and evaluate their functionality on in vitro models of intestinal permeability and gut-immune response. FrieslandCampina will play an integral role by supplying processed milk sources and by sharing their knowledge on scalability and quality control processes. The University of Applied Sciences Utrecht will be vital in performing in dept human intestinal organoid studies including the cross-talk with the host-microbiome ecosystem. 

We have successfully developed an alternative EV isolation technique that yields the same amount of particles as the most commonly used ultracentrifugation method but of higher purity and can be upscaled (patent to be filed). Furthermore, biological activity of mEVs was demonstrated in an functional assay using human chondrocytes (Published PMID: 34965027). Unfortunately, it was not feasible to determine the effect of mEVs on the barrier function using intestinal cell lines and for that we have developed a 2D-intestinal model using human colon organoids. Overall, our results suggest that the main effect of cow milk EVs might be rather on the intestinal immune defense and for this to prove in follow-up studies, a human intestinal organoid model with immune cells must be developed.