image: Scheme illustrating the comparison between the blood-brain barrier (BBB) and the gut-vascular barrier (GVB). The BBB is a selective barrier important for the protection of central nervous system from toxins and for the delivery of nutrients. Brain capillaries are covered by pericytes and are contacted by astrocytes and neurons. Together these cells form the functional unit called neuro-vascular unit. Similar to BBB, gut endothelial cells are organized in a gut-vascular unit since they are surrounded by enteric glial cells and pericytes. In unperturbed state, GVB controls the type of antigens that are translocated across the endothelial cells to reach the systemic circulation and prohibits entry of the intestinal microbiota. Intestinal pathogens such as Salmonella typhimurium can disrupt the GVB to favor their systemic dissemination. Indeed during infection gut endothelial cells show modified permeability to macromolecules and they up-regulate the expression of PV1 (Plasmalemma Vesicle Associated Protein-1), marker of leaky vascular barriers. This material relates to a paper that appeared in the Nov. 13, 2015 issue of Science, published by AAAS. The paper, by I. Spadoni at European Institute of Oncology in Milan, Italy, and colleagues was titled, 'A gut-vascular barrier controls the systemic dissemination of bacteria.' view more
Credit: Illustration by Ilaria Spadoni