SCAVENGING, SIGNALING AND ADHESION COUPLING IN MACROPHAGES - IMPLICATIONS FOR ATHEROGENESIS

Integrins are in physical association and functional cooperation with other membrane proteins that include receptors with scavenger function s, glycosyl-phosphatidylinositol-linked receptors, the family of integ rin associated multimembrane spanning signalling proteins and possibly other less characterized proteins with a coupling or signalling funct ion, Monocyte adhesion, migration and differentiation to phagocyticall y active scavenger cells are directly coupled processes, involving int egrins as common transducers for a panel of integrin-linked specific r eceptors, which assemble a master cluster to coordinate adhesion, migr ation, scavenging and associated metabolic pathways of the lysosomal a nd secretory route, and also processes involved in host response. As m acrophages represent highly heterogeneous cells that have major phenot ypical and functional differences associated with specific patterns of integrin expression, the functional cooperation of integrins with sca venger receptors has to be related to specialized subsets of monocytes and macrophages as well as to ligand specific effects which mediate r eceptor coupling.