Role of the CD40/CD40L dyad in atherosclerosis

描述（由申请人提供）：动脉粥样硬化最初被认为是脂肪沉积导致的进行性血管闭塞的简单过程，但越来越多地被认为是一种复杂的多因素疾病。特别是，动脉粥样硬化形成作为一种（慢性）炎症性疾病的识别以及免疫介质的影响有助于我们最近对这种流行的人类疾病的理解。申请人之前的工作确立了CD40/CD40配体(CD40L)二元体在体外和体内动脉粥样硬化形成中的显着作用，并且进一步确定了CD40/CD40L相互作用的中断作为预防斑块进展和介导与斑块稳定相关的过程的潜在治疗靶点。然而，CD40/CD40L 二元体在免疫系统中的核心作用可能会限制这些研究中采用的基于抗体的方法的临床应用。该提案将评估 CD40/CD40L 二元体促进动脉粥样硬化形成的病理生理学途径，以协助设计治疗这种常见人类疾病的明确治疗策略。具体目标 I：表征 CD40L 在血栓形成和/或溶栓中的作用。申请人的初步研究表明CD40信号传导在血栓形成中具有新颖的、先前未被怀疑的功能。将使用小鼠和人的血液制剂在体外和离体研究通过可溶性和/或膜相关的 CD40L 对纤维蛋白凝块形成的调节。此外，将测试凝血级联介质增强 CD40/CD40L 表达的假设。具体目标 II：检验 EC、SMC 和单核细胞/巨噬细胞在 CD40/CD40L 介导的动脉粥样硬化形成中采用差异信号转导途径的假设。将表征由 EC、SMC 和单核细胞/巨噬细胞上的 CD40 连接触发的信号转导途径以及与动脉粥样硬化相关的诱导介质（例如组织因子）。这些研究将扩展申请人的初步工作，涉及这些动脉粥样硬化相关细胞类型中 CD40 信号传导中的 TRAF 和不同转录因子。具体目标 III：确定与 CD40/CD4OL 介导的动脉粥样硬化形成相关的细胞类型。申请人的初步研究表明Ldlr/CD40L复合突变小鼠的动脉粥样硬化减轻。 Ldlr-、CD40/Ldlr-和 CD40L/Ldlr 复合突变小鼠将用于骨髓重建研究，以表征与 CD40/CD40L 介导的体内动脉粥样硬化斑块形成、进展和分化相关的细胞类型。这三个具体目标的结合不仅将为 CD40/CD40L 二元体在动脉粥样硬化中的作用提供新的见解，而且还可能有助于确定未来治疗的明确治疗靶点。

DESCRIPTION (provided by applicant): Originally considered a simple process of progressive blood vessel occlusion by fatty deposits, atherosclerosis is increasingly appreciated as a complex and multifactorial disease. In particular, the identification of atherogenesis as a (chronic) inflammatory disease and the implication of immune mediators contributed to our recent understanding of this prevalent human disease. Previous work by the applicants established a prominent role of the CD40/CD40 ligand (CD40L) dyad in atherogenesis in vitro and in vivo, and furthermore identified the interruption of CD40/CD40L interactions as a potential therapeutic target preventing plaque progression and mediating processes associated with plaque stabilization. The central role of the CD40/CD40L dyad within the immune system, however, may limit the clinical application of the antibody-based approach employed in these studies. This proposal will evaluate the pathophysiologic pathways via which the CD40/CD40L dyad promotes atherogenesis to assist in the design of defined therapeutic strategies for the treatment of this prevalent human disease. Specific Aim I: To characterize the role of CD40L in thrombosis and/or thrombolysis. Preliminary studies of the applicants suggested novel, previously unsuspected, functions of CD40 signaling in thrombosis. The modulation of fibrin clot formation via soluble and/or membrane-associated CD40L will be investigated in vitro and ex vivo, employing murine as well as human blood preparations. Furthermore, the hypothesis that mediators of the coagulation cascade enhance CD40/CD40L expression will be tested. Specific Aim II: To test the hypothesis that EC, SMC, and monocytes/macrophages employ differential signal transduction pathways in CD40/CD40L-mediated atherogenesis. Signal transduction pathways triggered by the ligation of CD40 on EC, SMC, and monocytes/macrophages and inducing mediators relevant to atherosclerosis, e.g., tissue factor, will be characterized. These studies will extend preliminary work by the applicants, implicating TRAFs and distinct transcription factors in CD40 signaling within these atheroma-associated cell types. Specific Aim III: To determine the cell types relevant for CD40/CD4OL-mediated atherogenesis. Preliminary studies by the applicants demonstrated diminished atherosclerosis in Ldlr/CD40L compound mutant mice. Ldlr-, CD40/Ldlr-, and CD40L/Ldlr compound mutant mice will be employed in bone marrow reconstitution studies to characterize the cell type(s) relevant to the CD40/CD40L-mediated formation, progression, and differentiation of atherosclerotic plaques in vivo. The combination of these three specific aims will not only provide novel insights into the role of the CD40/CD40L dyad in atherosclerosis, but may also aid identification of defined therapeutic targets for future treatment.