Myeloid cell interactions with T cells in atherosclerosis

Summary

Principal Investigator: Klaus F Ley
Abstract: DESCRIPTION (provided by applicant): We hypothesize that different subsets of myeloid cells have distinct and overlapping functions in atherosclerosis. Here, we propose to test which subsets are responsible for inflammatory cytokine production, antigen presentation, and foam cell formation, and how these processes are modulated by platelet factor 4 (Pf4, also known as CXCL4). Macrophage accumulation initiates the formation of fatty streaks, which eventually develop into atherosclerotic lesions. Macrophages are also critically involved in vulnerable plaque, whose rupture triggers major adverse cardiovascular events (MACE). Macrophages and DCs are antigen- presenting cells (APCs) that interact with T cells, amplifying inflammation. CD4 T cell interaction with APCs is evident in multiphoton microscopy: the T cells pause when they form an immunological synapse. CXCL4, the product of the Pf4 gene, is pro-atherogenic and drastically alters macrophage phenotype. To investigate APC functions, foam cell formation, antigen presentation and the impact of Pf4 on these processes, we propose to combine newly developed multiphoton live cell imaging of the aortic wall with flow cytometry, immunofluorescence and histology. Specific aim 1 is to test which subsets of myeloid cells become foam cells in the aortic wall, using aortic wall flow cytometry and multiphoton live cell imaging in GFP-tagged Apoe-/- mice. We have generated LysMGFP Apoe-/-, Cx3cr1GFP Apoe-/- and CD11cYFP Apoe-/- mice. In each of these mouse strains, different subsets of myeloid cells are green (or yellow) fluorescent. Specific aim 2 is to test the effects of T cell interactios with macrophages and dendritic cells on atherosclerosis. T cells derived from OTII transgenic mice express a monoclonal TCR that recognizes an ovalbumin peptide. Polyclonal T cells, some of which are specific to "atherosclerosis antigens", are isolated from dsRed Apoe-/- mice. These T cells are transferred to aortas of LysMGFP Apoe-/-, Cx3cr1GFP Apoe-/- and CD11cYFP Apoe-/- mice to test their interactions with APCs, which are expected to induce T cell proliferation (BrdU), polarization (interferon-[unreadable], IL-17A) and foam cell formation (oxLDL uptake). Specific aim 3 is to investigate the effect of platelet factor 4 on foam cell formation an function. PF4 is a strong modulator of macrophage phenotype, promoting the M4 phenotype in vitro. Pf4-/-Apoe-/- mice have been reported to develop smaller atherosclerotic lesions. To address possible mechanisms, we propose to cross Pf4-/-Apoe-/- mice with our fluorescent reporter mice to visualize changes in myeloid subset composition, phenotype and behavior in these mice. When this research is complete, we will know which macrophage subset(s) become foam cells, which interact with T cells in a productive immune response to trigger re-stimulation, proliferation and cytokine production, and how PF4 influences both processes. PF4 or other molecules investigated here may emerge as targets for prevention or therapy of atherosclerosis and its complications.
Funding Period: 2012-07-01 - 2017-05-31
more information: NIH RePORT

Top Publications

  1. pmc Interleukin-27 receptor limits atherosclerosis in Ldlr-/- mice
    Ekaterina K Koltsova
    Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
    Circ Res 111:1274-85. 2012
  2. pmc Regulated accumulation of desmosterol integrates macrophage lipid metabolism and inflammatory responses
    Nathanael J Spann
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, 92093 0651, USA
    Cell 151:138-52. 2012
  3. pmc Increased atherosclerotic lesion formation and vascular leukocyte accumulation in renal impairment are mediated by interleukin-17A
    Shuwang Ge
    From the Department of Medicine, Hannover Medical School, Hannover, Germany
    Circ Res 113:965-74. 2013

Detail Information

Publications3

  1. pmc Interleukin-27 receptor limits atherosclerosis in Ldlr-/- mice
    Ekaterina K Koltsova
    Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
    Circ Res 111:1274-85. 2012
    ..The expression of the IL-27 subunit Ebi3 is elevated in human atheromas, yet its function in atherosclerosis remains unknown...
  2. pmc Regulated accumulation of desmosterol integrates macrophage lipid metabolism and inflammatory responses
    Nathanael J Spann
    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, 92093 0651, USA
    Cell 151:138-52. 2012
    ..These observations suggest that macrophage activation in atherosclerotic lesions results from extrinsic, proinflammatory signals generated within the artery wall that suppress homeostatic and anti-inflammatory functions of desmosterol...
  3. pmc Increased atherosclerotic lesion formation and vascular leukocyte accumulation in renal impairment are mediated by interleukin-17A
    Shuwang Ge
    From the Department of Medicine, Hannover Medical School, Hannover, Germany
    Circ Res 113:965-74. 2013
    ..How atherosclerotic inflammation is altered in renal impairment is incompletely understood...

Research Grants30

  1. Pathophysiology of Alveolar Epithelial Lung Injury
    Jacob I Sznajder; Fiscal Year: 2013
    ..The insights gained from the data generated from these studies will provide novel molecular targets for the development of new therapeutic strategies to treat patients with lung injury. ..
  2. Mental Stress Ischemia: Prognosis and Genetic Influences
    Arshed A Quyyumi; Fiscal Year: 2013
    ....
  3. Cellular and molecular mechanisms of endothelial repair and atherosclerosis
    Jason Ciril Kovacic; Fiscal Year: 2013
    ..Here, we will investigate the cellular and molecular mechanisms dictating cardiovascular morbidity and mortality, with a view to making meaningful inroads into the prevention and treatment of this epidemic. ..
  4. Cardiac Myosin Binding Protein-C: Structure, Function, and Regulation
    David M Warshaw; Fiscal Year: 2013
    ..abstract_text> ..
  5. Endothelial Injury and Repair: CardioPulmonary Vascular Biology COBRE
    SHARON IRENE SMITH ROUNDS; Fiscal Year: 2013
    ..abstract_text> ..
  6. Interactions Between Inflammation, Oxidant Stress and Cardiovascular Disease
    David G Harrison; Fiscal Year: 2013
    ..Overall, these studies will promote our understanding of the interplay between inflammation, oxidant stress and cardiovascular disease. ..
  7. LIPID AND LIPOPROTEIN METABOLISM IN ATHEROSCLEROSIS
    Alan M Fogelman; Fiscal Year: 2013
    ..These six Projects will be supported by four cores and together will form a highly interactive and synergistic Program Project that is focused on lipid and lipoprotein metabolism in atherosclerosis. ..
  8. Digitalis-Induced Signaling by Cardiac Na+/K+-ATPase
    Amir Askari; Fiscal Year: 2013
    ..abstract_text> ..
  9. Mechanisms of Microvascular Control and Coordination in Health and Disease
    Gerald A Meininger; Fiscal Year: 2013
    ..End of Abstract) ..
  10. INTEGRATED MECHANISMS OF CARDIAC MALADAPTATION
    R John Solaro; Fiscal Year: 2013
    ..Studies proposed here offer the potential for novel diagnostic procedures early in the progression of the disorders, and targets for novel therapies. (End of Abstract) ..
  11. Interactive Signaling Modules in Vascular Inflammation
    Linda H Shapiro; Fiscal Year: 2013
    ..abstract_text> ..
  12. Discovery and Development of Therapeutic Genes for CHF
    H Kirk Hammond; Fiscal Year: 2013
    ..Four Cores will support the Program: Digital Imaging (Dr. Farquhar);Vector Production (Dr. Miyanohara);Translational Systems (Dr. Hammond) and Clinical &Administrative (Dr. Hammond). ..