KIM185, A MONOCLONAL-ANTIBODY TO CD18 WHICH INDUCES A CHANGE IN THE CONFORMATION OF CD18 AND PROMOTES BOTH LFA-1-DEPENDENT AND CR3-DEPENDENT ADHESION

Unactivated peripheral blood leukocytes show little tendency to bind t o other cells or matrix components, whilst, in the presence of inflamm atory mediators, adhesive interactions can rapidly increase. The Leu-C AM (beta2 integrin) family of adhesion molecules have been shown to me diate a variety of these induced adhesion events. Here we describe a m onoclonal antibody against CD18, KIM185, which stimulates JY cell homo typic aggregation by a CD11a pathway as well as inducing the adherence ot neutrophils to protein-coated plastic by a CD11b-dependent mechani sm. The antibody recognizes an epitope distinct from the previously de scribed KIM127 antibody and evidence is presented that the binding of KIM185 can cause a change in the conformation of the CD18 molecule.