Monocyte adherence to human vascular endothelium.

An acute inflammatory response requires that circulating monocytes bind to and migrate across the endothelium of the vessel wall to gain access to inflamed sites. Various mediators of inflammation--cytokines and chemoattractants--have been shown to initiate and regulate the margination and extravasation of monocytes. This review summarizes evidence that the mechanism underlying the initial adhesion of monocytes to normal and cytokine-stimulated endothelial cells and their subsequent transendothelial migration are successive events in monocyte-endothelial cell interaction. Special emphasis is given to the current knowledge of the contribution of adhesion molecules belonging to the family of beta 1- and beta 2-integrins, the immunoglobulin supergene family, and the selectins to such cellular interaction. The sequence of events that allow monocytes to attach to, migrate over and finally pass the endothelium is discussed in detail.