Periodic Reporting for period 1 - Striking streaks (Invariant Natural Killer T-cells in atherogenesis)
Reporting period: 2018-09-01 to 2020-08-31
Many survivors of childhood chronic disease struggle with early atherosclerosis later in life. As a physician-scientist I am inspired by their lifelong fight, and my research focuses on the etiology, diagnosis, and prevention of early atherosclerosis in children at risk. During the MSCA Fellowship I studied one of the cellular players involved in atherogenesis, so-called invariant Natural Killer T (iNKT) cells. iNKT cells are unique immune cells for their restriction to lipid antigens rather than peptide antigens, which underlies their pivotal role in lipid-driven disorders such as atherosclerosis. The exact role of iNKT cells in atherogenesis however remains elusive, because the origin of the lipid antigens in atherosclerosis is currently unknown. Importantly, more insight in the role of iNKT cells in atherogenesis may enable harnessing of iNKT cells for cardiovascular protection in the future.
During my MSCA Fellowship at the cardiovascular immunology laboratory of Professor Monaco at the Kennedy Institute of the University of Oxford, I focused on three objectives. First, I studied whether lipid antigens are contained in the circulating lipoprotein fraction, which plays a critical role in atherosclerosis. Next, I studied the impact of lipoprotein-associated lipid antigens on iNKT cell function. Finally, I explored whether manipulation of lipoprotein metabolism impacts the function of iNKT cells.
Since circulating lipoproteins routinely contain lipids that are structurally similar to lipid antigens, I hypothesized that circulating lipoproteins would also contain lipid antigens for iNKT cells. I developed CD1d-sortagging as a novel and innovative approach for lipid antigen identification. CD1d-sortagging employs bacterial sortase enzymes for site-specific cleavage and biotin labeling of CD1d-lipid antigen complexes, followed by isolation and potentially identification of the lipid antigens. Using CD1d-sortagging and state-of-the-art microscopy techniques, I have been able to show that circulating lipoproteins can indeed contain lipid antigens for iNKT cell function. Furthermore, I discovered that the containment of lipid antigens in lipoproteins affects iNKT cell function. Finally, I showed that manipulation of lipoprotein metabolism impacts the delivery of lipid antigens to antigen presenting cells, and thereby the function of iNKT cells. In conclusion, the MSCA Fellowship project showed that lipoproteins are not only involved in plaque development as lipid deposits, but also play a role in the activation of iNKT cells.
During my MSCA Fellowship at the cardiovascular immunology laboratory of Professor Monaco at the Kennedy Institute of the University of Oxford, I focused on three objectives. First, I studied whether lipid antigens are contained in the circulating lipoprotein fraction, which plays a critical role in atherosclerosis. Next, I studied the impact of lipoprotein-associated lipid antigens on iNKT cell function. Finally, I explored whether manipulation of lipoprotein metabolism impacts the function of iNKT cells.
Since circulating lipoproteins routinely contain lipids that are structurally similar to lipid antigens, I hypothesized that circulating lipoproteins would also contain lipid antigens for iNKT cells. I developed CD1d-sortagging as a novel and innovative approach for lipid antigen identification. CD1d-sortagging employs bacterial sortase enzymes for site-specific cleavage and biotin labeling of CD1d-lipid antigen complexes, followed by isolation and potentially identification of the lipid antigens. Using CD1d-sortagging and state-of-the-art microscopy techniques, I have been able to show that circulating lipoproteins can indeed contain lipid antigens for iNKT cell function. Furthermore, I discovered that the containment of lipid antigens in lipoproteins affects iNKT cell function. Finally, I showed that manipulation of lipoprotein metabolism impacts the delivery of lipid antigens to antigen presenting cells, and thereby the function of iNKT cells. In conclusion, the MSCA Fellowship project showed that lipoproteins are not only involved in plaque development as lipid deposits, but also play a role in the activation of iNKT cells.
Since circulating lipoproteins routinely contain lipids that are structurally similar to lipid antigens, I hypothesized that circulating lipoproteins would also contain lipid antigens for iNKT cells. I developed CD1d-sortagging as a novel and innovative approach for lipid antigen identification. CD1d-sortagging employs bacterial sortase enzymes for site-specific cleavage and biotin labeling of CD1d-lipid antigen complexes, followed by isolation and potentially identification of the lipid antigens. Using CD1d-sortagging and state-of-the-art microscopy techniques, I have been able to show that circulating lipoproteins can indeed contain lipid antigens for iNKT cell function. Furthermore, I discovered that the containment of lipid antigens in lipoproteins affects iNKT cell function. Finally, I showed that manipulation of lipoprotein metabolism impacts the delivery of lipid antigens to antigen presenting cells, and thereby the function of iNKT cells. In conclusion, the MSCA Fellowship project showed that lipoproteins are not only involved in plaque development as lipid deposits, but also play a role in the activation of iNKT cells.
Exploitation of the results:
The MSCA Fellowship enabled the development of CD1d-sortagging in vitro, as a novel and promising tool to identify CD1d-associated lipid antigens. Though the use of CD1d-sortagging in vivo has yet to be shown, CD1d-sortagging may provide novel opportunities for lipid antigen identification in many other settings. We are in close communication with the Knowledge Transfer office at the University to exploit successful use in vivo, hopefully in the near future.
Dissemination of the results:
The study results have been disseminated in several ways:
- Scientific presentations: 2018 EULAR congress, 2019 ESC congress, 2020 internal seminar Kennedy Institute University of Oxford, 2020 Seminar at the Weatherall Institute of Molecular Medicine, University of Oxford, 2020 Oxford Metabolic Health Symposium.
- Scientific publications: 2 scientific publications have been submitted, 1 is currently under revision.
- Patient involvement: study plans and results were presented at the yearly Pulse meeting of the Dutch Heart foundation, which provides a platform for interaction with patients, industry, and policy makers.
- Public engagement: I have participated in the European Researcher’s night, and visited a primary school to present my research and inspire a passion for science.
Impact of COVID-19 on work performed:
- The generation of a CD1d-sortagging mouse model was delayed. Therefore, identification of lipoprotein-associated iNKT cell antigens in vivo could not yet be performed.
- There were no human plaques available during the COVID-19 epidemic. Therefore, human atheroma cell cultures could not be employed to study the impact of plaque-associated lipid antigens on the intra-lesional cytokine environment.
Exploitation of the results:
The MSCA Fellowship enabled the development of CD1d-sortagging in vitro, as a novel and promising tool to identify CD1d-associated lipid antigens. Though the use of CD1d-sortagging in vivo has yet to be shown, CD1d-sortagging may provide novel opportunities for lipid antigen identification in many other settings. We are in close communication with the Knowledge Transfer office at the University to exploit successful use in vivo, hopefully in the near future.
Dissemination of the results:
The study results have been disseminated in several ways:
- Scientific presentations: 2018 EULAR congress, 2019 ESC congress, 2020 internal seminar Kennedy Institute University of Oxford, 2020 Seminar at the Weatherall Institute of Molecular Medicine, University of Oxford, 2020 Oxford Metabolic Health Symposium.
- Scientific publications: 2 scientific publications have been submitted, 1 is currently under revision.
- Patient involvement: study plans and results were presented at the yearly Pulse meeting of the Dutch Heart foundation, which provides a platform for interaction with patients, industry, and policy makers.
- Public engagement: I have participated in the European Researcher’s night, and visited a primary school to present my research and inspire a passion for science.
Impact of COVID-19 on work performed:
- The generation of a CD1d-sortagging mouse model was delayed. Therefore, identification of lipoprotein-associated iNKT cell antigens in vivo could not yet be performed.
- There were no human plaques available during the COVID-19 epidemic. Therefore, human atheroma cell cultures could not be employed to study the impact of plaque-associated lipid antigens on the intra-lesional cytokine environment.
The MSCA project has impact on several levels:
- Impact on the researcher’s career: The MSCA Fellowship has been essential to strengthen my fundamental research skills, start a fundamental research line into the effects of dyslipidemia on immune cell function and atherosclerosis, and develop a strategic international network. Moreover, the MSCA Fellowship enhanced my competitiveness for national (e.g. NWO-VIDI) and European (e.g. ERC) grants to establish my own translational research group on early atherosclerosis in children, now I have returned to the Netherlands. -
- Impact on society: An emerging number of studies indicates that children with chronic disease are at risk for early atherosclerosis. The MSCA Fellowship supported my research into early atherosclerosis in children with chronic disease. In the near future, I envision the development of a multi-disciplinary cardiovascular follow-up and prevention program for children at risk for early atherosclerosis.
- Impact on policy making: The Dutch Heart Foundation recently established early prevention of atherosclerosis as one of their policy cornerstones, and primary aims. The MSCA Fellowship supported my research into early atherosclerosis in children with chronic disease, and therefore fully aligns with the policy of the Dutch Heart Foundation.
- Impact on the researcher’s career: The MSCA Fellowship has been essential to strengthen my fundamental research skills, start a fundamental research line into the effects of dyslipidemia on immune cell function and atherosclerosis, and develop a strategic international network. Moreover, the MSCA Fellowship enhanced my competitiveness for national (e.g. NWO-VIDI) and European (e.g. ERC) grants to establish my own translational research group on early atherosclerosis in children, now I have returned to the Netherlands. -
- Impact on society: An emerging number of studies indicates that children with chronic disease are at risk for early atherosclerosis. The MSCA Fellowship supported my research into early atherosclerosis in children with chronic disease. In the near future, I envision the development of a multi-disciplinary cardiovascular follow-up and prevention program for children at risk for early atherosclerosis.
- Impact on policy making: The Dutch Heart Foundation recently established early prevention of atherosclerosis as one of their policy cornerstones, and primary aims. The MSCA Fellowship supported my research into early atherosclerosis in children with chronic disease, and therefore fully aligns with the policy of the Dutch Heart Foundation.