<b>A MONOCLONAL ANTIBODY RECOGNIZING ENDOTHELIAL CELLS OVERLYING ATHEROSCLEROTIC LESIONS IN THE </b><b>RABBIT </b>

Abstract

We prepared a monoclonal antibody (MAb 1-168) which recognizes the endothelial cells in the rabbit atherosclerotic aorta, by immunizing mice with the homogenate of atherosclerotic aorta of rabbits fed a high cholesterol diet. Indirect immunofiuorescence microscopy of the cryosections revealed that MAb 1-168 exclusively stained the endothelial cells overlying the lesions. Specific immunofluorescences were observed in the cytoplasm as dot or stripe-like patterns. In contrast, specific immunolabellings were scarcely detected in the endothelial cells overlying the nonlesional area in the aorta of cholesterol-fed and normal rabbits. MAb 1-168 also stained cultured porcine endothelial cells. Relatively weak fluorescences were observed along the cell periphery and stress fibers. The molecular weight of the antigenic material was identified as 40 kDa by SDS-PAGE and Western blot analysis of cultured porcine endothelial cells and rabbit atherosclerotic lesions. These findings suggest that the antigenic material may be an actin cytoskeleton-related substance that increased in the endothelial cells overlying the atherosclerotic plaques.A During the pathogenesis of atherosclerosis, the intima of arteries becomes thickened because of foam cell accumulation and smooth muscle cell proliferation. Damage or dysfunction of the arterial endothelial layer is also considered to be one of the most important events in the development of atherosclerotic lesions (17, 18). Using animal models, many investigators have demonstrated atherogenesis-related endothelial functional alterations such as the adhesion of blood cells to the endothelium