Lectin-like oxidized LDL receptor-1 (LOX-1) supports adhesion of mononuclear leukocytes and a monocyte-like cell line THP-1 cells under static and flow conditions

Adhesion of mononuclear leukocytes to vascular endothelial cells appears one of the initial steps in the process of atherogenesis and inflammation. We examined if LOX-1, an endothelial scavenger receptor with C-type lectin-like structure, can support adhesion of mononuclear leukocytes. Under a static condition, CHO-K1 cells stably expressing LOX-1 showed more prominent adhesion of human peripheral blood mononuclear leukocytes and THP-1 cells than untransfected CHO-K1 cells, in a temperature-independent fashion. Mononuclear leukocytes also adhered to plastic plates precoated with recombinant soluble LOX-1 extracellular domain. A neutralizing anti-LOX-1 monoclonal antibody, as well as oxidized low-density lipoprotein, significantly blocked adhesion of THP-1 cells to CHO-K1 cells overexpressing LOX-1 and bovine aortic endothelial cells. Under a flow condition, increased numbers of THP-1 cells showed rolling with reduced velocities on LOX-1-expressing CHO-K1 cells, compared with those on untransfected CHO-K1 cells. Taken together, LOX-1 can work as a cell surface receptor for mononuclear leukocytes under both static and flow conditions.