Lentiviral Gene Therapy for Wiskott-Aldrich Syndrome

描述（由申请人提供）： 该提案旨在开发一种有效且安全的Wiskott-Aldrich综合征（WAS）基因治疗的临床前模型。虽然使用HLA匹配的骨髓移植可以治愈年轻的WAS患者，但随着年龄的增长，成功率福尔斯急剧下降。多条证据证明了表达WASP的造血细胞亚群的强选择性优势，表明将正常WASP基因引入造血干细胞（HSC）中可以在疾病管理中提供可行的治疗替代方案。虽然概念简单，但开发安全有效的WASP基因置换策略需要在人类和动物系统中进行广泛的临床前建模。该提案利用了联合的专业知识以及重要的研究和临床合作者网络，建立了一个慢病毒递送系统，用于WAS的确定性基因治疗。我们将检验以下假设：1）WASP活性对于边缘区（MZ）B细胞的生成和功能性T调节细胞（TR）的稳态都是至关重要的;这些观察结果有助于解释WAS患者对包囊细菌感染的易感性和自身免疫的高发病率。此外，我们预测LV基因治疗将挽救这些关键缺陷。2)含有泛造血或选择的淋巴限制性启动子的慢病毒载体将导致WAS动物模型中淋巴发育、活化和存活的功能校正;血小板周转;和体内免疫功能。3)在非人灵长类动物模型中分析病毒标记和表达将使我们能够定义用于人类临床试验的最佳载体;并提供关于该载体的任何潜在毒性和/或HSC及其后代中WASP表达失调的关键数据。我们提出的研究将提供几乎所有的关键表达，疗效和安全性数据，以推进WAS的人类基因治疗试验;并有很高的可能性转化为新的疗法。

DESCRIPTION (provided by applicant): This proposal seeks to develop an effective and safe pre-clinical model for gene therapy in Wiskott- Aldrich Syndrome (WAS). While transplantation using HLA-matched bone marrow can be curative for young WAS patients, the success rate falls precipitously with increasing age. Multiple lines of evidence document a strong selective advantage for WASP expressing hematopoeitic cell subsets suggesting that introduction of the normal WASP gene into hematopoietic stem cells (HSC) could provide a viable therapeutic alternative in disease management. While conceptually simple, development of a safe and effective strategy for WASP gene replacement requires extensive pre-clinical modeling in human and animal systems. This proposal takes advantage of combined expertise, and a network of important research and clinical collaborators, to establish a lentiviral delivery system for the definitive genetic treatment of WAS. We will test the hypotheses that: 1) WASP activity is crucial for both the generation of marginal zone (MZ) B cells and homeostasis of functional T-regulatory cells (TR); and that these observations help to explain the susceptibility to infection with encapsulated bacteria, and the high-incidence of autoimmunity in WAS patients, respectively. Further, we predict that LV gene therapy will rescue these key defects. 2) Lentiviral vectors containing a pan-hematopoeitic or selected lymphoid restricted promoters will lead to functional correction of lymphoid development, activation, and survival; platelet turnover; and immune function in vivo in an animal model of WAS. 3) Analysis of viral marking and expression in a non-human primate model will allow us to define the optimal vector for use in human clinical trials; and provide key data with regard to any potential toxicity of this vector and/or dysregulated WASP expression within HSC and their progeny. Our proposed studies will provide nearly all of the key expression, efficacy, and safety data required to move forward with a human gene therapy trial for WAS; and have a very high likelihood for translation into new therapies.