THE UPTAKE AND TRANSPORT OF NANOPARTICLES IN THE MURINE SMALL INTESTINE

The small intestine is a mucosal surface that is exposed to a large number of antigens from food and commensal organisms and preferentially develops a state of unresponsiveness or tolerance to these antigens. Epithelial cells take up soluble antigens leading to the development of oral tolerance. Goblet cells are also capable taking up soluble antigen. M cells, known for the uptake of particulate antigen, are found primarily in the follicle-associated epithelium, which is not critical for oral tolerance. To determine whether intestinal epithelial cells (IECs) take up particulate antigen, fluorescent nanoparticles 0.02 - 2 μm in diameter were administered to mice. It was found that IECs and goblet cells take up nanoparticles ≤40 nm in diameter and these nanoparticles are rapidly transported to the mesenteric lymph nodes, an organ important for the induction of tolerance to dietary antigens and immunity to pathogens