White blood cells interacting with the venular wall
The movie shows white blood cells interacting with the venular wall in an inflamed tissue. To do their job, white cells must be carried by the blood stream to the site of inflamation, where they must cross the blood vessel wall in order to migrate into the tissue on their mission to search out and destroy pathogens. This complex sequence of cellular events includes many steps. Initially leukocytes roll along the endothelial surface - transient interactions that are mediated by the selectin family of adhesion molecules. If conditions are right, they are activated and firmly adhere via a second family of cell adhesion molecules; they eventually flatten and migrate across the endothelial cell wall. To do this, they must communicate with the endothelial cells to cause them to “unzip” their cell-cell junctions in an organised and reversible way. We are interested in understanding how each of these steps is regulated in blood perfused microvessels, with particular focus on the role of firm adhesion in signaling to the endothelial cells to increase their permeability.