Peroxidized lipoproteins recognized by a new monoclonal antibody (DLR1a/104G) in atherosclerotic lesions

Monoclonal DLR1a/104G antibody, which recognizes peroxidized lipoproteins, was raised. Mice were immunized with the float-up fraction of the atherosclerotic arterial homogenate from WHHL rabbits. Sensitized spleen cells were fused with myeloma cells (3P/U1). Hybridoma clones were selected using peroxidized LDL prepared by CuSO4-catalyzed peroxidation and native LDL as positive and negative standards, respectively. The monoclonal DLR1a/104G antibody was highly reactive with peroxidized LDL, slightly with LDL modified with malondialdehyde, but not significantly with acetyl- or native LDL. The antigenicity in the case of peroxidized LDL did not decrease on extraction with hexane/isopropanol (3:2). The antigenicity coincided with the fluorescence (E350, F430) of the protein fraction of LDL peroxidized with CuSO4. These results suggest that an antigenic determinant exists in atherosclerotic lesions, which is the same as that for lipoproteins peroxidized with CuSO4.