Comprehensive Gene Therapy for Mucopolysaccharidosis VII

描述（由申请人提供）：我们的长期目标是开发安全有效的方法，用于粘多糖沉积症的综合基因治疗，其特征是溶酶体糖胺聚糖（GAG）沉积，由遗传性缺乏GAGs逐步降解所需的酶引起。由于GAG沉积物影响多个系统，包括肝脏、脾脏、骨骼、大脑和眼睛，因此这些疾病的基因治疗提出了特殊的挑战。在这个项目中，我们将针对粘多糖沉积症-VTI（MPS-VII，β-葡萄糖醛酸酶缺乏症，Sly综合征），因为有一个良好的表征小鼠模型。在初步研究中，我们已经表明，使用基于SV 40的重组载体转移β-葡萄糖醛酸苷酶（GUSB）基因具有改善大脑以及肝脏和脾脏中GAG沉积的潜力。第一个具体目标是优化基于SV 40的载体，用于安全有效的系统性基因转移。将产生新型病毒基因缺失载体以容纳启动子，用于在各种组织中有效地长期转基因表达。将引入绝缘子以保护宿主基因组中的相邻基因不被载体内的增强子意外激活。在具体目标2中，我们将确定最佳给药途径、基因转移的有效性、组织和血清GUSB水平以及含GAG的溶酶体囊泡的减少。除了评估肝脏和脾脏的表型校正外，还将特别强调在静脉内、脑室内或脑内注射载体后将基因转移到大脑不同区域中的各种类型的脑细胞。我们还将确定将这些载体注射到新生或胎鼠中对在发育早期纠正GUSB缺陷的能力的潜力，从而预防早期脑损伤，这在MPS VII中很常见。由于基于SV-40的载体无毒、无免疫原性并且能够整合到宿主基因组中，因此该项目的成功完成应为与内脏、骨骼和中枢神经系统损伤相关的所有形式的溶酶体贮积症的综合分子治疗提供安全有效的方法。

DESCRIPTION (provided by applicant): Our long-term objective is to develop safe and effective methods for comprehensive gene-based therapies for mucopolysaccharidoses, which are characterized by lysosomal glycosaminoglycan (GAG) deposition, resulting from inherited deficiency of enzymes needed for stepwise degradation of GAGs. Because GAG deposits affect multiple systems, including the liver, spleen, bones, brain and eyes, gene therapy for these disorders present a special challenge. In this project, we will target mucopolysaccharidosis-VTI (MPS-VII, beta-glucuronidase deficiency, Sly syndrome), since a well-characterized murine model is available. In preliminary studies, we have shown that transfer of the beta-glucuronidase (GUSB) gene using recombinant SV40-based vectors has the potential to ameliorate the GAG deposits in the brain as well as in the liver and spleen. The first specific aim is to optimize SV40- based vectors for safe and efficient systemic gene transfer. Novel viral gene-deleted vectors will be generated to accommodate promoters for efficient long-term transgene expression in various tissues. Insulators will be introduced to protect neighboring genes in the host genome from being accidentally activated by enhancers within the vector. In Specific Aim 2, we will determine optimal routes of administration, efficacy of gene transfer, tissue and serum GUSB levels and reduction of GAG-containing lysosomal vesicles. In addition to evaluating phenotypic correction of the liver and spleen, special emphasis will be placed on gene transfer to various types of brain cells in different regions of the brain after intravenous, intracerebro-ventricular or intracerebral injection of the vectors. We will also determine the potential of injecting these vectors into newborn or fetal mice on the ability to correct GUSB deficiency early in development, thereby preventing early brain damage, which is common in MPS VII. Since SV-40-based vectors are non-toxic, non-immunogenic and capable of integrating into the host genome, successful completion of this project should provide a safe and effective method for comprehensive molecular therapy of all forms of lysosomal storage disorders that are associated with visceral, skeletal and central nervous system injury.