Anti-oxidised low-density lipoprotein antibodies and antibody fragment targeted nanoparticles for the translational study of atherosclerosis
File(s)
Author(s)
Hartley, Adam
Type
Thesis
Abstract
There is an unmet need in prevention of cardiovascular disease, through predicting and preventing future index events; as well as a requirement for better prevention of recurrent events. This project focuses on these two needs, through development of antibodies against malondialdehyde-modified low-density lipoprotein (MDA-LDL) as biomarkers of atherosclerosis and antibody-conjugated nanoparticles for molecular targeting of atherosclerosis. One further objective is to develop a novel translational model, aiming to reduce reliance on animals in preclinical atherosclerosis research.
Firstly, I explored the relationship between IgG/ IgM antibodies against MDA-LDL with atherosclerosis and exercise. Serum was utilised from patients with chest pain undergoing computerised tomography coronary angiography in the SCOT-HEART trial and patients with coronary artery disease in the ORBITA trial. The SCOT-HEART study reports that both anti-MDA-LDL antibodies protectively related to atherosclerotic plaque characteristics. The ORBITA study demonstrates that exercise results in reduced anti-MDA-LDL antibody levels, which was unaffected by percutaneous coronary intervention.
Secondly, I harnessed LO1Fab as a targeting ligand for fluorescent nanoparticles, aiming to localise to MDA-LDL-rich atherosclerotic plaques. LO1Fab is a humanised fragment of LO1, which is a monoclonal murine antibody that recognises MDA-LDL. The final optimised nanoparticle construct underwent vigorous in vitro testing prior to in vivo evaluation, where nanoparticles localised to atherosclerotic regions in vivo, confirmed on ex vivo analysis.
Lastly, I developed an amputated human limb model of atherosclerosis, consisting of perfusing a limb with oxygenated blood via a pulsatile pump under physiological conditions. The model has been successfully performed, with X-ray angiography, intravascular ultrasound and optical coherence tomography. In a proof-of-concept study, circulated indocyanine green localised to atherosclerotic regions on fluorescence reflectance imaging.
In summary, this thesis demonstrates the utility of antibodies against MDA-LDL as serological and molecular targeting agents of atherosclerosis in vivo, whilst also developing a novel experimental model of atherosclerosis.
Firstly, I explored the relationship between IgG/ IgM antibodies against MDA-LDL with atherosclerosis and exercise. Serum was utilised from patients with chest pain undergoing computerised tomography coronary angiography in the SCOT-HEART trial and patients with coronary artery disease in the ORBITA trial. The SCOT-HEART study reports that both anti-MDA-LDL antibodies protectively related to atherosclerotic plaque characteristics. The ORBITA study demonstrates that exercise results in reduced anti-MDA-LDL antibody levels, which was unaffected by percutaneous coronary intervention.
Secondly, I harnessed LO1Fab as a targeting ligand for fluorescent nanoparticles, aiming to localise to MDA-LDL-rich atherosclerotic plaques. LO1Fab is a humanised fragment of LO1, which is a monoclonal murine antibody that recognises MDA-LDL. The final optimised nanoparticle construct underwent vigorous in vitro testing prior to in vivo evaluation, where nanoparticles localised to atherosclerotic regions in vivo, confirmed on ex vivo analysis.
Lastly, I developed an amputated human limb model of atherosclerosis, consisting of perfusing a limb with oxygenated blood via a pulsatile pump under physiological conditions. The model has been successfully performed, with X-ray angiography, intravascular ultrasound and optical coherence tomography. In a proof-of-concept study, circulated indocyanine green localised to atherosclerotic regions on fluorescence reflectance imaging.
In summary, this thesis demonstrates the utility of antibodies against MDA-LDL as serological and molecular targeting agents of atherosclerosis in vivo, whilst also developing a novel experimental model of atherosclerosis.
Version
Open Access
Date Issued
2024-01-04
Date Awarded
2024-06-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Khamis, Ramzi
Haskard, Dorian
Mason, Justin
Sponsor
Wellcome Trust (London, England)
Grant Number
220572/Z/20/Z
Publisher Department
National Heart & Lung Institute
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)