Lipid Metabolism in Experimental Atherosclerosis Induced by Immunization with Human Native High- Density Lipoproteins

The etiology of atherosclerosis, which underlies a broad spectrum of cardiovascular diseases, remains unknown. There is currently no doubt that autoimmune reactions are involved in the pathogenesis of atherosclerosis. We previously showed that immunizing rats and rabbits with human native lipoproteins in incomplete Freund’s adjuvant (IFA) results in atherosclerosis-like changes in the aortic wall. However, the mechanisms of the atherogenic effect of the anti-lipoprotein antibodies, in particular their effect on lipid metabolism, remain unclear. The aim of this study was to examine lipid metabolism in rats and rabbits with atherosclerosis-like aortic changes induced by immunization with native human high-density lipoproteins (nhHDL). For this purpose, we compared the lipid profile of blood plasma and peripheral blood mononuclear cells (PBMC) in nhHDL/IFA-immunized rats and rabbits and in IFA-injected animals. Histology studies of the aortic wall in nhHDL/IFA-immunized rabbits and rats revealed atherosclerosis-like changes, while in IFAinjected rats and rabbits, no aortic changes were found. Changes in the lipid profile of blood plasma and PBMC were comparable in animals immunized with nhHDL/IFA and those that received only an IFA injection. Consequently, the changes in the lipid profile of the blood plasma and PBMC of animals immunized with nhHDL/IFA were induced by the IFA and not associated with the immune reaction to the lipoproteins, while the atherosclerosis-like changes in the aortic wall of rabbits and rats caused by the immune reaction to native HDL are not mediated by changes in lipid metabolism