Leukocyte-derived CR3 modulator, integrin modulating factor-1 (IMF-1)

摘要

The invention is concerned with the discovery, isolation and purification of an agent or factor named herein the CR3 modulator or CMF-1 that is synthesized by polymorphonuclear leukocytes (PMN) in response to agonists which enhance CD18 activity. The CR3 modulator binds to CD18 and activates its adhesion-promoting ability. The CR3 modulator appears to be transiently produced by PMN as an acidic amphiphilic lipid. The CR3 modulator can be assayed by adding dilutions of a CR3 modulator -containing solution to resting PMN and observing the ability of CR3 to mediate binding of erythrocytes coated with C3bi (EC3bi). The isolation of the CR3 modulator, its biological and physical properties and diagnostic and therapeutic uses are described.