VIRAL CHEMOKINE RECEPTORS: TRANSPLANT VASCULAR SCLEROSIS

病毒趋化因子受体：移植血管硬化

• 批准号: 6231417
• 负责人: SUSAN L ORLOFF
• 金额: $ 26.43万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6231417
• 关键词: arteriosclerosis; atherosclerosis; biological signal transduction; cell migration; cell type; cytokine receptors; cytomegalovirus; disease /disorder model; gene expression; gene mutation; heart transplantation; immunocytochemistry; in situ hybridization; laboratory rat; muscle cells; pathologic process; polymerase chain reaction; protein structure function; receptor expression; recombinant virus; sclerosis; smooth muscle; tissue /cell culture; transplant rejection; virus infection mechanism

The long term goal of this project is to identify mechanisms involved with human cytomegalovirus (HCMV) acceleration of transplant vascular sclerosis. The primary cause of graft loss of all vascularized organ transplants is due to a vascular lesion associated with chronic rejection. This form of vasculopathy referred to as TVS is characterized by concentric neointimal smooth muscle cell proliferation that results in vessel occlusion and ultimately graft failure. To date the only therapy available to treat severe TVS is retransplantation. Clinical studies in transplant recipients have demonstrated a direct link between HCMV and the acceleration of TVS. Based on these findings, we have developed a rat model of heart and small bowel transplantation in which CMV infection accelerates the time and severity of TVS. While the exact mechanism through which CMV mediates this process is unknown, recent work from our group suggests that CMV may contribute to TVS through induction of smooth muscle cell (SMC) migration towards sites of chemokine production through expression of a virally encoded chemokine receptor (US28). We have also observed that Rat and Murine CMV also induce SMC migration through their respective viral chemokine receptors R33 and M33, which are functional homologues of HCMV US28. We hypothesize that the mechanism of CMV-accelerated TVS involves the expression of virally encoded chemokine receptors leading to intimal SMC migration, which results in the characteristic vascular lesions of TVS. Therefore, we will utilize our in vitro and in vivo models to extend our observations and determine the role of virally encoded chemokine receptors in the development of TVS in three specific aims. First, using a rat cardiac transplant model of chronic rejection, we will determine the effects of virus on the kinetics of disease progression of TVS and the extent of viral expression in tissues as well as the cell types involved in the process. We will also determine the host factors such as chemokines and cytokines, and the contribution of R33 involved at various stages of the development of RCMV-induced TVS. Secondly, we will characterize the R33 domains involved in signaling which induce SMC migration and the ligands, which serve as agonists or antagonists to induced cellular movement. In the last specific, we will generate recombinant RCMV which contain mutations in domains involved in signaling to understand their contribution to TVS in the rat cardiac transplant model. Lastly, antagonists of R33 induced SMC migration in vitro will be tested for their ability to block TVS in the in vivo rat model. These studies will provide a valuable animal model to understand the role of CMV in the acceleration of TVS. In addition completion of these studies will form the basis for novel and rational design of therapeutic strategies to enhance long-term graft survival in HCMV infected transplant recipients.

该项目的长期目标是确定与人巨细胞病毒（HCMV）加速移植血管硬化有关的机制。所有血管化器官移植物移植物损失的主要原因是与慢性排斥相关的血管病变。这种形式的血管病变被称为 TVS，其特征是同心新内膜平滑肌细胞增殖，导致血管闭塞并最终导致移植失败。迄今为止，治疗严重 TVS 的唯一疗法是再移植。对移植受者的临床研究表明，HCMV 与 TVS 加速之间存在直接联系。基于这些发现，我们开发了一种心脏和小肠移植的大鼠模型，其中 CMV 感染加速了 TVS 的时间和严重程度。虽然 CMV 介导这一过程的确切机制尚不清楚，但我们小组最近的工作表明，CMV 可能通过表达病毒编码的趋化因子受体 (US28) 诱导平滑肌细胞 (SMC) 迁移到趋化因子产生位点，从而促成 TVS ）。我们还观察到，大鼠和小鼠 CMV 还通过各自的病毒趋化因子受体 R33 和 M33 诱导 SMC 迁移，R33 和 M33 是 HCMV US28 的功能同源物。我们推测CMV加速TVS的机制涉及病毒编码的趋化因子受体的表达导致内膜SMC迁移，从而导致TVS的特征性血管病变。因此，我们将利用我们的体外和体内模型来扩展我们的观察，并确定病毒编码的趋化因子受体在 TVS 发展中的作用，以实现三个特定目标。首先，利用慢性排斥反应的大鼠心脏移植模型，我们将确定病毒对 TVS 疾病进展动力学的影响以及病毒在组织中表达的程度以及参与该过程的细胞类型。我们还将确定趋化因子和细胞因子等宿主因素，以及 R33 在 RCMV 诱导的 TVS 发展各个阶段的贡献。其次，我们将表征参与诱导 SMC 迁移的信号传导的 R33 结构域和作为诱导细胞运动的激动剂或拮抗剂的配体。在最后一个具体内容中，我们将生成重组 RCMV，其中包含信号传导相关域的突变，以了解它们对大鼠心脏移植模型中 TVS 的贡献。最后，将测试 R33 体外诱导 SMC 迁移的拮抗剂在体内大鼠模型中阻断 TVS 的能力。这些研究将为了解 CMV 在 TVS 加速中的作用提供有价值的动物模型。此外，这些研究的完成将为新颖且合理的治疗策略设计奠定基础，以提高 HCMV 感染的移植受者的长期移植物存活率。