Genetic Therapy for CNS Manifestations in MPS I via BBB-targeted Protein Delivery

摘要 粘多糖样沉积症I型（MPS I），由α-L- 艾杜糖醛酸酶（IDUA）是最常见的溶酶体贮积病（LSD）之一 影响中枢神经系统（CNS），无法通过电流治愈 治疗。我们已经证明，慢病毒载体（LV）介导的基因传递可以 在血浆中产生持续的超生理IDUA水平， 治疗中枢神经系统的表现，如果血脑屏障（BBB）可以克服。的 内源性受体介导的转胞吞系统在血脑屏障形成中的应用 脑毛细血管内皮将能够快速和广泛地递送神经治疗剂 通过循环穿过血脑屏障拟议工作的总体目标是制定一个 利用低密度脂蛋白受体家族（LDLRf）的新治疗方法- 介导的转胞吞作用，用于通过LV介导的基因将融合蛋白递送穿过BBB 在肝脏和/或HSC中转移，用于治疗MPS I的CNS表现。 我们将通过体外和体内评价，确定LDLRf的最佳结合结构域， apoE用于最有效的BBB转运，同时保留正常的催化功能， 融合IDUA的溶酶体酶运输（特异性目的1）。的空间和时间 将研究CNS和外周器官中的蛋白质分布谱，靶向 肝或HSC衍生的红系细胞作为组织特异性转基因的贮库器官 在不同年龄的小鼠中的产量（具体目标2）。临床前评价将 在鼠MPS I模型中进行，以通过GAG试验确定CNS治疗的窗口 用于代谢校正、CNS正常化和行为的病理学评价 改善CNS功能缺陷的评估（具体目标3）。采取 总之，这些研究不仅将导致开发一种新的方法， 使用终身BBB靶向蛋白治疗神经系统疾病，如MPS I 传递，而且还提供了重要的知识，在体内的变化，受体介导的 BBB运输系统随年龄增长或处于病理状态。

Abstract Mucopolysaccharidosis type I (MPS I), resulting from the deficiency of alpha-L- iduronidase (IDUA), is one of the most common lysosomal storage diseases (LSD) affecting the central nervous system (CNS), which cannot be cured by current treatments. We have shown that lentiviral vector (LV)-mediated gene delivery can produce sustained supraphysiological IDUA levels in plasma and may be therapeutic in treating CNS manifestations if the blood-brain barrier (BBB) can be overcome. The utilization of the endogenous receptor-mediated transcytosis system on BBB-forming brain capillary endothelium will enable rapid and wide delivery of neurotherapeutics across the BBB via circulation. The overall goal of the work proposed is to develop a novel therapeutic approach utilizing low-density lipoprotein receptor family (LDLRf)- mediated transcytosis for fusion protein delivery across the BBB via LV-mediated gene transfer in the liver and/or the HSC for the treatment of CNS manifestations in MPS I. We will identify, by in vitro and in vivo evaluation, the optimal LDLRf-binding domain of apoE for most efficient BBB transport while retaining the normal catalytic function and lysosomal enzyme trafficking of fusion IDUA (Specific Aim 1). The spatial and temporal protein distribution profile will be studied in the CNS and peripheral organs, targeting the liver or HSC-derived erythroid cells as depot organ for tissue-specific transgene production in mice with different ages (Specific Aim 2). Preclinical evaluation will be conduced in a murine MPS I model to identify window of CNS treatment by GAG assay for metabolic correction, pathology evaluation for CNS normalization and behavioral assessments for improvement of CNS functional deficits (Specific Aim 3). Taken together, these studies will not only lead to the development of a novel approach for the treatment of neurological diseases, such as in MPS I, with lifelong BBB-targeted protein delivery, but also provide important knowledge of in vivo changes in receptor-mediated BBB transport system with aging or under pathological conditions.