Chapter 14 Adhesive proteins and their cellular receptors
Abstract Many, and perhaps most, important cell adhesion receptors and ligands have been identified and characterized. The reagents, systems, and technologies are therefore available for a “reductionist” approach to the roles of cell adhesion in processes such as the interaction of blood with biomedical materials. Key to the success of this approach is the recognition that the same molecules or families of molecules are responsible for many different processes in organisms that have evolved over hundreds of millions of years. For instance, the α IIb β 3 integrin receptor that mediates platelet adhesion and aggregation and is defective in Glanzmann thrombasthenia in humans is very similar to the receptor that mediates muscle attachment and is defective in fruitflies with the myospheriod phenotype. The challenges to the field of cell adhesion are to understand the events that control the activities of adhesion receptors and ligands, the signals that emanate from ligated receptors, and how the signals are processed to influence behavior when cells encounter surfaces or other cells. To exemplify these issues, this chapter focuses on the α v β 3 integrin receptor, an adhesive ligand for the receptor, vitronectin; and modulation of cellular adhesion to vitronectin by high-molecular-weight kininogen. Platelet adhesion to biomaterials is contrasted with the more complex phenomenon of neutrophil adhesion to vascular endothelial cells.