Improved HSV Vectors: Gene Transfer into Nervous System

描述(申请人提供)：基因转移方法创造了 为人类神经系统疾病开发基因治疗的机会 帕金森氏病(PD)。因为帕金森病代表了一组临床上相似的 每个症状都由不同的机制触发，我们假设存在 一条共同的下游病理生理途径。我们的目标是开发治疗方法 用于指向路径中的共享公共节点的PD。对这种情况的阐述 神经保护性基因治疗取决于安全和 一种高效的基因转移载体，可表达治疗肿瘤的基因 在特定的神经元群体中延长了周期。当前可用的 单纯疱疹病毒(HSV)直接基因治疗载体 “扩增”载体已被证明能同时容纳一个大的(9kb) 酪氨酸羟化酶(TH)启动子片段并提供高度选择性 黑质多巴胺(DA)神经元的基因表达。然而，HSV 扩增载体表现出转基因沉默，这是一种一次性的障碍 为慢性病(如帕金森病)服药。我们的数据表明转基因 沉默是异染色质形成的结果。这样做的目的之一是 项目是通过改变载体的倾向来颠覆转基因沉默 形成异染色质。在具体目标1中，我们检查了多个不同的 刺激常染色质形成的途径，即染色质状态 支持长期基因表达。与发展有关的第二个问题 帕金森病基因治疗的核心是将不同的治疗基因定向到每个隔室 病变的黑质纹状体通路：多巴胺神经元和靶区纹状体。在……里面 具体目标2我们将开发单独的载体，以提供直接 不同基因产物在每个解剖区段的表达。三分之一 PD基因治疗成功的问题是在适当的动物模型中进行评估 这种疾病的危害。《特定目标3》将采用两种动物模型：我们的小说 A-突触核蛋白导致进行性黑质纹状体功能障碍的小鼠 黑质TH和运动功能减退；以及我们改良的慢性MPTP 纹状体失神经、多巴胺能细胞丢失和 神经行为综合征。建议的研究将产生优化的HSV 媒介，提供对其特征的详细了解，以及 评估它们在机械上不同的帕金森病模型中的有效性。

DESCRIPTION (provided by applicant): Gene transfer methods have created the opportunity for developing gene therapy for human neurological diseases such as Parkinson's Disease (PD). Since PD represents a group of clinically similar syndromes each triggered by a different mechanism we hypothesize the existence of a shared downstream pathophysiologic pathway. Our goal is to develop therapy for PD directed at a shared common node in the pathway. The elaboration of such neuroprotective gene therapy is contingent on the development of safe and efficacious gene transfer vectors that can express a therapeutic gene for a prolonged period in specific neuronal populations. Of the currently available vehicles for direct gene therapy only plasmid based herpes simplex virus (HSV) "amplicon" vectors have been demonstrated to both accommodate a large (9 kb) tyrosine hydroxylase (TH) promoter fragment and to provide highly selective gene expression in dopamine (DA) neurons in the substantia nigra. However, HSV amplicon vectors exhibit transgene silencing that is an impediment to one-time dosing for a chronic disease such as PD. Our data indicate that transgene silencing results from heterochromatin formation. One of the goals of this project is to subvert transgene silencing by altering the propensity of vector to form heterochromatin. In Specific Aim 1 we examine multiple different approaches to stimulate euchromatin formation, that chromatin state posited to support long term gene expression. A second issue pertinent to the development of PD gene therapy is to direct different therapeutic genes to each compartment of the diseased nigrostriatal pathway: dopamine neurons and target striatum. In Specific Aim 2 we will develop separate vectors which will afford direct expression of different gene products to each anatomical compartment. A third issue for successful PD gene therapy is evaluation in appropriate animal models of the disease. Specific Aim 3 will employ two animal models: Our novel a-synuclein mice which develop progressive nigrostriatal dysfunction, reduction of substantia nigra TH and hypokinetic activity; and our modified chronic MPTP model which produces striatal denervation, dopaminergic cell loss and a neurobehavorial syndrome. The proposed studies will yield optimized HSV vectors, provide a detailed understanding of their characteristics, and evaluate their effectiveness in mechanistically different models of PD.