Role of the CD40/CD40L dyad in atherosclerosis

描述(由申请人提供)：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，动脉粥样硬化越来越被认为是一种复杂和多因素的疾病。特别是，动脉粥样硬化是一种(慢性)炎症性疾病，免疫介质的含义有助于我们最近对这一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)二联体在体外和体内动脉粥样硬化形成中的重要作用，并进一步确定CD40/CD40L相互作用的中断是防止斑块进展和调节与斑块稳定相关的过程的潜在治疗靶点。然而，CD40/CD40L二联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。这项建议将评估CD40/CD40L双联体促进动脉粥样硬化的病理生理途径，以帮助设计明确的治疗策略来治疗这种流行的人类疾病。具体目的I：研究CD40L在血栓形成和/或溶栓中的作用。对申请者的初步研究表明，CD40信号在血栓形成中的作用是新的，以前没有人怀疑过。通过可溶性和/或膜相关的CD40L对纤维蛋白凝块形成的调节将在体外和体外进行研究，使用小鼠和人的血液标本。此外，凝血级联介质增强CD40/CD40L表达的假设将得到验证。特定目的II：验证EC、SMC和单核/巨噬细胞在CD40/CD40L介导的动脉粥样硬化形成中采用不同的信号转导途径的假说。CD40在EC、SMC和单核/巨噬细胞上的结扎所触发的信号转导通路以及与动脉粥样硬化相关的诱导介质，如组织因子，将被描述。这些研究将扩展申请者的初步工作，涉及TRAF和不同的转录因子在这些动脉粥样硬化相关细胞类型的CD40信号中的作用。特定目的III：确定与CD40/CD4OL介导的动脉粥样硬化形成相关的细胞类型。申请者的初步研究表明，Ldlr/CD40L复合突变小鼠的动脉粥样硬化程度有所减轻。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的形成、发展和分化相关的细胞类型(S)。这三个特定目标的结合不仅将为CD40/CD40L二联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.