MEASUREMENT OF GLYCATED LDL WITH MONOCLONAL ANTIBODIES

THE LONG-TERM OBJECTIVE OF THIS PROJECT IS TO DEVELOP A SPECIFIC AND ACCURATE IMMUNODIAGNOSTIC TEST TO MEASURE THE AMOUNT OF NON-ENZYMATICALLY GLYCATED LOW DENSITY LIPOPROTEIN (LDL) IN HUMAN PLASMA. THE TEST WILL BE AN ELISA CONSTRUCT THAT EMPLOYS MONOCLONAL ANTIBODY THAT SPECIFICALLY RECOGNIZE GLYCATED LDL, AND DO NOT REACT WITH UNGLYCATED LDL MOIETIES. GLYCATION OF LDL, THE MAJOR CARRIER OF PLASMA CHOLESTEROL, IS A STRUCTURAL MODIFICATION THAT AFFECTS THE ATHEROGENIC POTENTIAL OF LIPOPROTEINS, AND THAT INCREASES THE SUSCEPTIBILITY OF DIABETIC SUBJECTS TO ATHEROSCLEROTIC COMPLICATIONS. IN PARTICULAR, EXPOSURE TO GLYCATED LDL LEADS TO INTRACELLULAR ACCUMULATION OF CHOLESTEROL ESTERS, COMPROMISES THE PHYSIOLOGICAL ABILITY OF LDL TO BE METABOLIZED BY THE LDL RECEPTOR PATHWAY, AND PROMOTES UPTAKE BY ALTERNATIVE RECEPTORS LEADING TO MORPHOLOGIC TRANSFORMATION OF MACROPHAGES INTO FOAM CELLS. THUS, MEASUREMENT OF GLYCATED LDL IN PLASMA OR SERUM MAY BE DIAGNOSTICALLY AND PROGNOSTICALLY IMPORTANT IN PATIENTS WITH DIABETES MELLITUS. HOWEVER, ASIDE FROM TIME CONSUMING, CUMBERSOME AND OFTEN INADEQUATE METHODS SUITABLE ONLY FOR RESEARCH LABORATORIES, THERE CURRENTLY ARE NO RELIABLE AND CONVENIENT MEANS TO ESTIMATING GLYCATED LDL CONCENTRATIONS IN CLINICAL SAMPLES. A SIMPLE AND SPECIFIC METHOD FOR MEASURING GLYCATED LDL IN PLASMA IS NEEDED NOT ONLY FOR ITS POTENTIAL AS A DIAGNOSTIC INDICATOR OF ATHEROGENESIS IN DIABETIC INDIVIDUALS, BUT ALSO FOR USE AS A REPRODUCIBLE PARAMETER FOR LONG TERM FOLLOW UP IN DIABETIC POPULATIONS TO ASSES THE PREDICTIVE VALUE AND RISK ASSOCIATED WITH ELEVATED LEVELS OF GLYCATED LDL. THIS PROJECT WILL EXPLOIT OUR RECENT DEMONSTRABLE SUCCESS IN CREATING UNIQUE AND HIGHLY SPECIFIC MONOCLONAL ANTIBODIES THAT RECOGNIZE GLYCATED EPITOPES RESIDING IN LDL APOPROTEIN BUT NOT IN OTHER PLASMA PROTEINS AND THAT DO NOT REACT WITH UNGLYCATED LDL.