A monoclonal autoantibody against a cryptic epitope on tissue-adherent low-density lipoprotein for molecular imaging in atherosclerosis
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Objectives We aimed to generate and characterize IgG monoclonal autoantibodies in atherosclerosis for targeting of novel molecular determinants.
Background Antibody-based constructs for molecular imaging and therapeutic delivery provide promising opportunities for the diagnosis and treatment of atherosclerosis.
Methods We created hybridomas from an unimmunized LDL receptor-deficient (Ldlr-/-) mouse and selected an IgG2b isotype autoantibody, LO9, for further characterization.
Results LO9 reacted well with native LDL bound to immobilized matrix components, and less well to oxidized LDL. LO9 binding to immobilized native LDL was not neutralized by fluid-phase native LDL, indicating an adhesion-dependent epitope. We localized the epitope to a 20 amino-acid peptide sequence (P5) in the globular amino-terminus of apolipoprotein B. LO9 reacted with antigen in mouse atherosclerosis and in both human stable and ruptured coronary atherosclerosis. Furthermore, in vivo near-infrared fluorescence molecular tomographic imaging and ex vivo confocal microscopy showed that intravenously injected LO9 localized beneath endothelium of the aortic arch in Ldlr-/- mice, in the vicinity of macrophages.
Conclusions We believe LO9 is the first example of an IgG autoantibody that reacts with a native LDL epitope revealed by adherence to tissue matrix. Antibodies against adherent native LDL have potential as molecular targeting agents for imaging of and therapeutic delivery to atherosclerosis.
Background Antibody-based constructs for molecular imaging and therapeutic delivery provide promising opportunities for the diagnosis and treatment of atherosclerosis.
Methods We created hybridomas from an unimmunized LDL receptor-deficient (Ldlr-/-) mouse and selected an IgG2b isotype autoantibody, LO9, for further characterization.
Results LO9 reacted well with native LDL bound to immobilized matrix components, and less well to oxidized LDL. LO9 binding to immobilized native LDL was not neutralized by fluid-phase native LDL, indicating an adhesion-dependent epitope. We localized the epitope to a 20 amino-acid peptide sequence (P5) in the globular amino-terminus of apolipoprotein B. LO9 reacted with antigen in mouse atherosclerosis and in both human stable and ruptured coronary atherosclerosis. Furthermore, in vivo near-infrared fluorescence molecular tomographic imaging and ex vivo confocal microscopy showed that intravenously injected LO9 localized beneath endothelium of the aortic arch in Ldlr-/- mice, in the vicinity of macrophages.
Conclusions We believe LO9 is the first example of an IgG autoantibody that reacts with a native LDL epitope revealed by adherence to tissue matrix. Antibodies against adherent native LDL have potential as molecular targeting agents for imaging of and therapeutic delivery to atherosclerosis.
Date Acceptance
2022-02-09
Citation
JACC: Cardiovascular Imaging, 15 (8)
ISSN
1876-7591
Publisher
Elsevier
Journal / Book Title
JACC: Cardiovascular Imaging
Volume
15
Issue
8
Copyright Statement
© 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open
access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Sponsor
Wellcome Trust
British Heart Foundation
Wellcome Trust
Identifier
https://www.sciencedirect.com/science/article/pii/S1936878X2200167X?via%3Dihub
Grant Number
FS/17/16/32560
203928/Z/16/Z
Subjects
atherosclerosis
lipids and cholesterol
molecular imaging
Animals
Antibodies, Monoclonal
Atherosclerosis
Autoantibodies
Epitopes
Humans
Immunoglobulin G
Lipoproteins, LDL
Mice
Molecular Imaging
Predictive Value of Tests
Animals
Humans
Mice
Lipoproteins, LDL
Immunoglobulin G
Antibodies, Monoclonal
Autoantibodies
Epitopes
Predictive Value of Tests
Atherosclerosis
Molecular Imaging
Cardiovascular System & Hematology
1102 Cardiorespiratory Medicine and Haematology
1103 Clinical Sciences
Publication Status
Published