Jesus Gil-Pulido1, Núria Amézaga1, Ivana Jorgacevic1, Helga D Manthey1, Melanie Rösch1, Theresa Brand2, Peter Cidlinsky1, Sarah Schäfer1, Andreas Beilhack3, Antoine-Emmanuel Saliba4, Kristina Lorenz2,5, Louis Boon6, Immo Prinz7,8, Ari Waisman9, Thomas Korn10,11,12, Clément Cochain1,13, Alma Zernecke1. 1. Institute of Experimental Biomedicine,University Hospital Würzburg, Würzburg, Germany. 2. Institute of Pharmacology and Toxicology,University of Würzburg, Würzburg, 97078 Germany. 3. Department of Internal Medicine II, University Hospital Würzburg, Würzburg, Germany. 4. Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Center for Infection Research (HZI), Würzburg, Germany. 5. Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, 44139 Germany. 6. Polpharma Biologics, Utrecht, the Netherlands. 7. Institute of Systems Immunology,University Medical Center Hamburg Eppendorf, Hamburg, Germany. 8. Institute of Immunology, Hannover Medical School, Hannover, Germany. 9. Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany. 10. Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. 11. Institute of Experimental Neuroimmunology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. 12. Munich Cluster for Systems Neurology (SyNergy), Munich, Germany. 13. Comprehensive Heart Failure Center, Würzburg, Germany.
Abstract
AIMS: Atherosclerosis is a chronic inflammatory disease of the vessel wall controlled by local and systemic immune responses. The role of interleukin-23 receptor (IL-23R), expressed in adaptive immune cells (mainly T helper 17 cells) and γδ T cells, in atherosclerosis is only incompletely understood. Here we investigated the vascular cell types expressing IL-23R and addressed the function of IL-23R and γδ T cells in atherosclerosis. METHOD AND RESULTS: IL-23R+ cells were frequently found in the aortic root in contrast to the aorta in low density lipoprotein receptor deficient IL-23R reporter mice (Ldlr-/-Il23rgfp/+), and mostly identified as γδ T cells that express IL-17 and GM-CSF. scRNA-seq confirmed γδ T cells as the main cell type expressing Il23r and Il17a in the aorta. Ldlr-/-Il23rgfp/gfp mice deficient in IL-23R showed a loss of IL-23R+ cells in the vasculature, and had reduced atherosclerotic lesion formation in the aortic root compared to Ldlr-/- controls after 6 weeks of high fat diet feeding. In contrast, Ldlr-/-Tcrδ-/- mice lacking all γδ T cells displayed unaltered early atherosclerotic lesion formation compared to Ldlr-/- mice. In both HFD-fed Ldlr-/-Il23rgfp/gfp and Ldlr-/-Tcrδ-/- mice a reduction in the plaque necrotic core area was noted as well as an expansion of splenic regulatory T cells. In vitro, exposure of bone marrow-derived macrophages to both IL-17A and GM-CSF induced cell necrosis, and necroptotic RIP3K and MLKL expression, as well as inflammatory mediators. CONCLUSIONS: IL-23R+ γδ T cells are predominantly found in the aortic root rather than the aorta and promote early atherosclerotic lesion formation, plaque necrosis and inflammation at this site. Targeting IL-23R may thus be explored as a therapeutic approach to mitigate atherosclerotic lesion development. TRANSLATIONAL PERSPECTIVE: The mechanisms and cell types contributing to early inflammation and lesion formation are incompletely understood. Here we demonstrate that the aortic root harbors a population of IL23R-dependent γδ T cells that can release IL-17 and GM-CSF, and both cytokines together induce macrophage inflammation and necroptosis. IL-23R+ γδ T cells locally promote early lesion formation in the aortic root and contribute to the expansion of the necrotic core, a hallmark of vulnerable atherosclerotic lesions. Targeting IL-23R or IL-23 itself could thus be further explored as a therapeutic option in early atherosclerosis. Published on behalf of the European Society of Cardiology. All rights reserved.
AIMS: Atherosclerosis is a chronic inflammatory disease of the vessel wall controlled by local and systemic immune responses. The role of interleukin-23 receptor (IL-23R), expressed in adaptive immune cells (mainly T helper 17 cells) and γδ T cells, in atherosclerosis is only incompletely understood. Here we investigated the vascular cell types expressing IL-23R and addressed the function of IL-23R and γδ T cells in atherosclerosis. METHOD AND RESULTS: IL-23R+ cells were frequently found in the aortic root in contrast to the aorta in low density lipoprotein receptor deficient IL-23R reporter mice (Ldlr-/-Il23rgfp/+), and mostly identified as γδ T cells that express IL-17 and GM-CSF. scRNA-seq confirmed γδ T cells as the main cell type expressing Il23r and Il17a in the aorta. Ldlr-/-Il23rgfp/gfp mice deficient in IL-23R showed a loss of IL-23R+ cells in the vasculature, and had reduced atherosclerotic lesion formation in the aortic root compared to Ldlr-/- controls after 6 weeks of high fat diet feeding. In contrast, Ldlr-/-Tcrδ-/- mice lacking all γδ T cells displayed unaltered early atherosclerotic lesion formation compared to Ldlr-/- mice. In both HFD-fed Ldlr-/-Il23rgfp/gfp and Ldlr-/-Tcrδ-/- mice a reduction in the plaque necrotic core area was noted as well as an expansion of splenic regulatory T cells. In vitro, exposure of bone marrow-derived macrophages to both IL-17A and GM-CSF induced cell necrosis, and necroptotic RIP3K and MLKL expression, as well as inflammatory mediators. CONCLUSIONS: IL-23R+ γδ T cells are predominantly found in the aortic root rather than the aorta and promote early atherosclerotic lesion formation, plaque necrosis and inflammation at this site. Targeting IL-23R may thus be explored as a therapeutic approach to mitigate atherosclerotic lesion development. TRANSLATIONAL PERSPECTIVE: The mechanisms and cell types contributing to early inflammation and lesion formation are incompletely understood. Here we demonstrate that the aortic root harbors a population of IL23R-dependent γδ T cells that can release IL-17 and GM-CSF, and both cytokines together induce macrophage inflammation and necroptosis. IL-23R+ γδ T cells locally promote early lesion formation in the aortic root and contribute to the expansion of the necrotic core, a hallmark of vulnerable atherosclerotic lesions. Targeting IL-23R or IL-23 itself could thus be further explored as a therapeutic option in early atherosclerosis. Published on behalf of the European Society of Cardiology. All rights reserved.