Endothelial cell biology. Adhesion molecules involved in the microvascular inflammatory response.

Accumulation of leukocytes in tissues is essential for effective host defense. To fulfill this role the cell must interact with and penetrate the vessel wall and migrate in the tissue. It is now clear that cell adhesion molecules play a crucial role in orchestrating these processes. A number of families of such adhesion molecules that mediate the interaction of circulating leukocytes and vascular endothelial cells have been identified. These include the leukocyte integrins, the selectins, members of the immunoglobulin family, and certain carbohydrates. Studies in vitro have elucidated which of these adhesion molecules are important in the interaction of different leukocyte classes with the endothelium under both basal and stimulated conditions. With the aid of monoclonal antibodies, the role that these molecules play in the interaction of inflammatory cells in the microvasculature in vivo is being assessed. Studies to date have demonstrated the key role of cell adhesion molecules in inflammation.