VAP-1: an adhesin and an enzyme

Leukocyte extravasation from the blood into tissues is of paramount importa nce for normal immunosurveillance and in mounting adequate inflammatory res ponses. Multiple traditional adhesion molecules and chemoattractants on leu kocytes and endothelial cells are involved in the emigration process. Vascu lar adhesion protein 1 (VAP-1) is a nonclassical inflammation-inducible end othelial molecule involved in leukocyte-subtype-specific rolling under phys iological shear. Molecularly. VAP-1 belongs to a special class of cell surf ace amino oxidases, The enzymatic reaction itself and the biologically acti ve end products can potentially regulate the adhesive status of the vessel wall. Thus, VAP-1 is an ectoenzyme that has inter-related adhesive and enzy matic functions in regulating physiological trafficking and inflammation.