Leukocyte adhesion - an integrated molecular process at the leukocyte plasma membrane

Leukocyte adhesion is of pivotal functional importance, because most leukoc yte functions depend on cell-cell contact. It must be strictly controlled, both at the level of specificity and strength of interaction, and therefore several molecular systems are involved. The most important leukocyte adhes ion molecules are the selectins, the leukocyte-specific beta(2)-integrins a nd the intercellular adhesion molecules. The selectins induce an initial we ak contact between cells, whereas firm adhesion is achieved through integri n-intercellular adhesion molecular binding. Although studies during the pas t twenty years have revealed several important features of leukocyte adhesi on much is still poorly understood, and further work dealing with several a spects of adhesion is urgently needed. In this short essay, we review some recent developments in the field.