ON THE MODE OF ACTION OF LFA-1

The leukocyte function-associated molecule 1 (LFA-1) plays a key role in cell adhesion among leukocytes and between leukocytes and other cell types. Although two ligands of LFA-1 have been identified, namely the intercellular adhesion molecules 1 (ICAM-1) and 2 (ICAM-2), the exact mechanism by which LFA-1 binds to and detaches from its ligand(s) has remained obscure. Based on novel findings Carl Figdor, Yvette van Kooyk and Gerrit Keizer now present a model of LFA-1-mediated lymphocyte adhesion, showing that LFA-1-dependent cell adhesion is a dynamic process in which ligand-binding affinity is regulated by intramolecular changes in LFA-1. This process is controlled by other lymphocyte surface structures, notably CD2 and CD3. © 1990.