Macrophage Scavenger Receptors: Structure, Function and Tissue Distribution.

Macrophage scavenger receptor (MSR) is one of the major receptors of macrophages. It plays an important role in the pathological deposition of cholesterol in macrophage-derived foam cells during atherogenesis through receptor-mediated uptake of modified low density lipoproteins. MSR is also important for macrophages to recognize and eliminate pathogenic microorganisms. Targeted disruption of the MSR gene resulted in a reduction in the size of atherosclerotic lesions in atherosclerosis model mice. MSR-knockout mice were more susceptible to infection. Hepatic granuloma formation induced by a single intravenous injection of heat-killed Corynebacterium parvum was significantly delayed in MSR-knockout mice. Using MSR-knockout mice as immunization animals, five monoclonal antibodies against human MSR were successfully produced. Immunohistochemistry using these antibodies revealed a restricted distribution of MSR protein on tissue macrophages in various tissues and organs. These antibodies will provide a new approach to study the role of MSR in normal and various pathological conditions in humans.