Detection of electronegative low density lipoprotein (LDL−) in plasma and atherosclerotic lesions by monoclonal antibody-based immunoassays

ObjectivesTo produce a monoclonal antibody (MAb) against electronegative LDL (LDL−) for detecting this modified lipoprotein in blood plasma and tissues.Design and methodsLDL− was isolated from human blood plasma and used as an antigen for immunization of Balb/c mice. Lymphocytes of immunized mice were fused with myeloma cells (SP2/0) to obtain the hybridomas. LDL− was detected in blood plasma and atherosclerotic lesions of humans and rabbits by MAb-based ELISA and immunohistochemistry, respectively.ResultsLDL− concentrations were higher (P < 0.05) in the blood plasma of hypercholesterolemic subjects (HC, 248 ± 77 mg/dL of total cholesterol) than in normolipidemic subjects (NL, 173 ± 82 mg/dL of total cholesterol) and rabbits (HC, 250 ± 15 mg/dL of cholesterol versus NL, 81 ± 12 mg/dL of cholesterol). Moreover, LDL− was detected in the atherosclerotic lesions of humans and rabbits.ConclusionThese MAb-based immunoassays are adequate to detect LDL− in biological samples and represent an important tool for investigating the role of LDL− in atherosclerosis.