Moderate oxidation of hypertriglyceridemic low-density lipoprotein causes apolipoprotein B epitope change and enhances its uptake by macrophages.
We prepared monoclonal antibody (MabB4) that selectively binds to acetylated low-density lipoprotein (LDL). Native hypertriglyceridemic LDL (HT-LDL) obtained from IIb and native normotriglyceridemic LDL (NT-LDL) from type IIa scarcely bound with MabB4. When these LDL were oxidized moderately by incubation with copper ions, the binding of MabB4 to HT-LDL was enhanced compared to that of NT-LDL, although the contents of the hydroperoxide they produced were the same. The incorporation of moderately oxidized HT-LDL into macrophages was enhanced compared to that of NT-LDL, and the rate of incorporation parallel the binding of LDL for MabB4. These results suggested that moderate oxidation of HT-LDL expressed some apolipoprotein B epitope on the surface of acetylated LDL to a much greater degree than NT-LDL, and that this expressed epitope might work as a ligand of moderately oxidized HT-LDL for the recognition by macrophages.
Ishikawa
Y
Y
Second Department of Internal Medicine, School of Medicine, Chiba University, Japan.
Inadera
H
H
Shirai
K
K
Hashimoto
H
H
Fukamachi
I
I
Saito
Y
Y
Yoshida
S
S
D001055:Apolipoproteins B / Q000737:chemistry / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood*; D008077:Lipoproteins, LDL / Q000276:immunology / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D010084:Oxidation-Reduction; D014280:Triglycerides / Q000276:immunology / Q000378:metabolism*
D001055:Apolipoproteins B; D000939:Epitopes; D008077:Lipoproteins, LDL; D014280:Triglycerides; C032607:low density lipoprotein triglyceride