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

描述(由申请人提供)： 摘要粘多糖I型(MPS I)是影响中枢神经系统(CNS)的最常见的溶酶体贮积性疾病之一，由α-L艾杜糖苷酶(IDUA)缺乏引起，目前的治疗方法难以治愈。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学IDUA水平，如果血脑屏障(BBB)能够被克服，那么它可能在治疗中枢神经系统症状方面起到治疗作用。内源性受体介导的跨细胞分泌系统在形成血脑屏障的脑毛细血管内皮细胞上的应用将使神经治疗药物能够通过循环快速和广泛地跨血脑屏障输送。这项工作的总体目标是开发一种新的治疗方法，利用低密度脂蛋白受体家族(LDLRf)介导的跨细胞传递融合蛋白，通过LV介导的肝脏和/或HSC中的基因转移来治疗MPS I中的CNS表现。我们将通过体外和体内评估，确定apoE的最佳LDLRf结合域，以最有效地运输BBB，同时保持融合IDUA的正常催化功能和溶酶体酶运输(特定目标1)。将研究蛋白质在中枢神经系统和外周器官中的空间和时间分布，目标是肝脏或HSC来源的红系细胞作为不同年龄小鼠组织特异性转基因产生的储藏器官(特定目标2)。将在小鼠MPS I模型中进行临床前评估，以确定中枢神经系统治疗的窗口，包括用于代谢校正的GAG检测、用于中枢神经系统正常化的病理学评估和用于改善中枢神经系统功能缺陷的行为评估(特定目标3)。综上所述，这些研究不仅将导致开发一种新的方法来治疗神经系统疾病，如MPS I，以终生BBB为靶向的蛋白输送，而且还将为体内受体介导的BBB运输系统随年龄或病理条件的变化提供重要的知识。 公共卫生相关性： 叙述血脑屏障阻碍了神经治疗和诊断试剂快速和广泛地输送到中枢神经系统的能力。本申请中描述的研究将打开治疗神经疾病的新方法的大门-从MPS I型到主要的公共卫生问题，如中风和阿尔茨海默病。

DESCRIPTION (provided by applicant): 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. PUBLIC HEALTH RELEVANCE: Narrative The blood-brain-barrier has hindered the capability of rapid and wide delivery of neurotherapeutics and diagnostic agents to the central nervous system. The studies described in this application will open the door to novel approaches for the treatment of neurological disorders-from MPS type I to major public health concerns such as stroke and Alzheimer's disease.