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，现在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）炎症性疾病的鉴定和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。申请人先前的工作确立了CD 40/CD 40配体（CD 40 L）二联体在体外和体内动脉粥样硬化形成中的突出作用，并且进一步鉴定了CD 40/CD 40 L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标。然而，CD 40/CD 40 L二联体在免疫系统中的中心作用可能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CD 40/CD 40 L二联体促进动脉粥样硬化形成的病理生理途径，以帮助设计治疗这种流行的人类疾病的明确治疗策略。具体目的I：描述CD 40 L在血栓形成和/或溶栓中的作用。申请人的初步研究表明了CD 40信号传导在血栓形成中的新的、先前未被怀疑的功能。通过可溶性和/或膜相关的CD 40 L调节纤维蛋白凝块形成将在体外和离体研究，采用鼠以及人的血液制剂。此外，将检验凝血级联的介质增强CD 40/CD 40 L表达的假设。具体目标二：为了验证EC、SMC和单核/巨噬细胞在CD 40/CD 40 L介导的动脉粥样硬化形成中采用不同信号转导途径的假设。EC、SMC和单核细胞/巨噬细胞上的CD 40连接触发的信号转导途径和诱导动脉粥样硬化相关介质，例如，组织因子，将被表征。这些研究将扩展申请人的初步工作，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中的CD 40信号传导。具体目的III：确定与CD 40/CD 4 OL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/CD 40 L复合突变小鼠中动脉粥样硬化减少。Ldlr-、CD 40/Ldlr-和CD 40 L/Ldlr复合突变小鼠将用于骨髓重建研究，以表征与体内CD 40/CD 40 L介导的动脉粥样硬化斑块形成、进展和分化相关的细胞类型。这三个特定目标的结合不仅将为CD 40/CD 40 L二分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.