Preparation and characterisation of two monoclonal antibodies against oxidatively modified low-density lipoprotein (O-LDL) and detection of O-LDL in serum in patients with coronary heart disease

Abstract

There is much evidence that oxidatively modified low-density lipoprotein (O-LDL) plays an important role in the pathogenesis of atherosclerosis. To investigate this further and to facilitate early diagnosis of atherosclerosis, we raised two monoclonal antibodies (mAbs) against O-LDL. Competitive assay showed that one of these, HOL3, recognised O-LDL oxidatively modified for 2, 8 and 16 h. The other, HOL5, interacted only with O-LDL oxidatively modified for 8 and 16 h. The immunological reactivities of the mAbs with serum of healthy donors indicated that the reactivity of HOL3 was stronger than that of HOL5, Compared with healthy donors, the corresponding optical density (OD) values of O-LDL in serum of coronary heart disease patients produced by the two mAbs were all higher, but the degrees of the increase were different. The increase in percentage of serum O-LDL detected with HOL5 in the CHD patients was 337%, while that with HOL3 was only 37%. Therefore, the mAbs, especially HOL5, may be useful tools for investigating O-LDL in the circulation of CHD patients. Because lipid peroxidation and subsequent modification of LDL also occur in some other diseases, these immunological reagents could also be useful in studies on their pathogenesis.