Endothelial Cells: Barrier between Blood and Tissue

In order to fight infections, leukocytes need to access microbes in tissues by extravasating from the flowing blood. This process that initiates inflammation and keeps it alive is controled by endothelial cells that form the interphase between blood and tissue. Whereas the mechanism of capturing leukocytes to the blood vessel wall at sites of inflammation is rather well understood, very little is known about how leukocytes actually overcome the blood vessel wall (diapedesis). It is considered as likely, although still controversially discussed by some, that leukocytes move into tissue by penetrating through the junctions of endothelial cells. One of the major goals of research of the department Vascular Cell Biology at the MPI for Molecular Biomedicine is to identify and understand the molecular mechanisms that allow paracellular diapedesis.