Lentiviral gene therapy for mucopolysaccharidosis

描述（由申请方提供）：II型粘多糖样变性（MPS II，亨特氏综合征）是一种X连锁隐性遗传性疾病，由艾杜糖醛酸-2-硫酸酯酶缺失引起，导致糖胺聚糖硫酸乙酰肝素和硫酸皮肤素全身蓄积。受影响的个体患有骨骼异常、器官肿大、危及生命的阻塞性气道疾病，并且在严重酶缺乏的形式下，患有神经变性和在15岁之前死亡。虽然造血干细胞的移植和植入在治疗某些MPS疾病中显示出有效性，但同种异体移植的MPSII患者迄今尚未表现出改善的神经学结局。在该项目中，我们假设由于从移植的细胞产生的IDS酶不足，所以同种异体移植用于MPSII是无效的，并且表达高水平IDS的供体细胞的基因工程将克服这种不足并提供包括疾病的神经学表现的有效代谢交叉校正。Lentigen是开发用于治疗人类疾病的慢病毒载体的领先公司。在这个I期STTR项目中，我们建议将联合收割机Lentigen的慢病毒载体技术与明尼苏达大学在溶酶体贮积病细胞疗法方面的经验相结合，开发一种治疗亨特氏综合征MPS II的离体转导方法。该提案的具体目的是：（i）构建和测试慢病毒载体，用于转导人类IDS基因沿着绿色荧光蛋白作为细胞标记。载体构建体将基于双启动子、双顺反子和融合蛋白策略产生，并使用Lentigen的专有LentiMax平台包装。(ii)通过将人IDS基因离体慢病毒转导到MSPII小鼠的造血干细胞中来校正代谢和神经疾病。将来自IDS缺陷型小鼠的骨髓用携带IDS基因的慢病毒载体转导，并移植到IDS缺陷型受体中，作为靶向造血干细胞的亨特氏综合征离体基因治疗的模型。将检测给药动物的供体细胞植入和转导、血浆和组织中IDS酶的表达、尿液和组织中储存物质的清除以及学习和运动功能神经行为测试中的表现改善。拟议研究的总体目标是提供临床前数据，以支持实施MPS II基因治疗的最直接和可行的方法，并对未来开发其他溶酶体贮积病的慢病毒基因疗法产生影响。

DESCRIPTION (provided by applicant): Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-linked recessive inherited disorder caused by absence of iduronate-2-sulfatase, resulting in systemic accumulation of glycosaminoglycans heparan sulphate and dermatan sulphate. Affected individuals suffer from skeletal abnormalities, organomegaly, life- threatening obstructive airway disease, and, in the severely enzyme deficient form, neurologic degeneration and death by age 15. While transplantation and engraftment of hematopoietic stem cells has shown efficacy in the treatment of some MPS diseases, allografted MPSII patients have thus far not exhibited improved neurologic outcomes. In this project, we hypothesize that allotransplant for MPSII is ineffective due to insufficient generation of IDS enzyme from engrafted cells, and that genetic engineering of donor cells to express high levels of IDS will overcome this insufficiency and provide effective metabolic cross- correction that includes neurologic manifestations of the disease. Lentigen is a leading company in the development of lentiviral vectors for treatment of human disease. In this Phase I STTR project, we propose to combine Lentigen's lentiviral vector technology with the University of Minnesota's experience in cellular therapies for lysosomal storage diseases by developing an ex vivo transduction approach for the treatment of Hunter syndrome, MPS II. The Specific Aims of the proposal are: (i) To construct and test lentiviral vectors for transduction of the human IDS gene along with green fluorescent protein as a cellular marker. Vector constructs will be generated based on dual promoter, bicistronic and fusion protein strategies, and packaged using Lentigen's proprietary LentiMax platform. (ii) Correction of metabolic and neurologic disease by ex vivo lentiviral transduction of the human IDS gene into hematopoietic stem cells of MSPII mice. Marrow from IDS deficient mice will be transduced with lentiviral vector carrying the IDS gene and transplanted into IDS deficient recipients as a model for ex vivo gene therapy of Hunter syndrome targeting hematopoietic stem cells. Treated animals will be tested for engraftment and transduction of donor cells, IDS enzyme expression in plasma and tissues, clearing of storage materials in urine and in tissues, and improved performance in neurobehavioral tests of learning and motor function. The overall goal of the proposed studies is to provide preclinical data to support the most straightforward and feasible approach for implementation of gene therapy for MPS II, with implications for the development of lentiviral gene therapies for other lysosomal storage diseases in the future.