CD36 IS A RECEPTOR FOR OXIDIZED LOW-DENSITY-LIPOPROTEIN

The oxidation of low density lipoprotein (LDL) in the arterial wall is thought to contribute to human atherosclerotic lesion formation, in p art by the high affinity uptake of oxidized LDL (OxLDL) by macrophages , resulting in foam cell formation. We have utilized cloning by expres sion to identify CD36 as a macrophage receptor for OxLDL. Transfection of a CD36 clone into 293 cells results in the specific and high affin ity binding of OxLDL, followed by its internalization and degradation. An anti-CD36 antibody blocks 50% of the binding of OxLDL to platelets and to human macrophage-like THP cells. Furthermore, like mouse macro phages, 293 cells expressing CD36 recognize LDL which has been oxidize d only 4 h, whereas more extensive oxidation of the LDL is required fo r recognition by the other known OxLDL receptors, the acetylated LDL ( AcLDL) receptor and FcgammaRII-B2. CD36 may play a role in scavenging LDL modified by oxidation and may mediate effects of OxLDL on monocyte s and platelets in atherosclerotic lesions.