Strategies for Sustained Effect of AAV-mediated Correction of Pompe Disease

AAV 介导的庞贝病纠正持续效果策略

• 批准号: 7489002
• 负责人: BARRY J BYRNE
• 金额: $ 31.02万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7489002
• 关键词: Ablation; Acids; Active Sites; Address; Adoptive Transfer; Affect; Alpha-glucosidase; Animal Model; Antibody Formation; Antigens; Binding; Biochemical; Cells; Condition; Data; Defect; Dendritic Cells; Depth; Development; Disease; Distal; Effectiveness; Epitopes; Functional disorder; Gene Delivery; Gene Expression; Gene Transfer; Glycogen; Glycogen Storage Disease; Glycogen storage disease type II; Goals; Grant; Heart; Hepatic Tissue; Hepatocyte; Human; Immune; Immune Tolerance; Immune response; Immunosuppressive Agents; In Vitro; Lead; Liver; Maps; Mediating; Metabolic; Metabolic Diseases; Modeling; Molecular; Mus; Muscle Weakness; Organ; Patients; Pharmaceutical Preparations; Phenotype; Post-Translational Protein Processing; Prevention; Property; Protein Precursors; Proteins; Reaction; Recombinant adeno-associated virus (rAAV); Recombinants; Replacement Therapy; Research Design; Research Personnel; Serotyping; Severities; Single-Gene Defect; Skeletal Muscle; Structure; Structure-Activity Relationship; Therapeutic; Tissues; Transgenes; Work; adeno-associated viral vector; base; clinically relevant; gene replacement; gene therapy; glucose-6-phosphatase; glucosidase; immunogenic; immunogenicity; immunoregulation; improved; in vivo; indexing; inorganic phosphate; insight; mouse model; novel; prevent; programs; protein distribution; protein structure; receptor; response; success; therapeutic gene; therapeutic protein; therapeutic transgene; uptake; vector; vector-induced

Glycogen storage disease type II (GSD II) is a prototypic metabolic storage disease resulting from a single gene defect. The availability of a mouse model has provided a forum in which to assess gene replacement therapy. In particular, we have investigated the feasibility of recombinant adeno-associated virus (rAAV)-mediated gene delivery of acid-alpha glucosidase (GAA) for liver-directed correction of a mouse model of GSD II. In previous studies, we have demonstrated high-efficacy in vivo gene transfer of GAA to heart and skeletal muscle using rAAV vectors. Recently, we have shown correction of distal tissues (cross-correction) via uptake of secreted protein resulting from over-expression of therapeutic GAA protein from hepatic tissue. However, we also noted that the levels of cross-correction that could be achieved were dependent on the level of humoral immune response to the expressed GAA. In this study, we propose to extend our studies and examine the potential of immune modulation to improve the efficacy of rAAV-mediated, liver-directed gene therapy for GSD II. In our initial studies, we will evaluate the efficacy of immunosuppressive drugs to prevent immune response to rAAV-derived or infused recombinant GAA protein. Interestingly, as others and we have noted some instances of rAAV-mediated immune tolerance to a therapeutic transgene, we propose to characterize the mechanism of vector-induced tolerance to GAA through adoptive transfer studies with the aim of optimizing rAAV-based therapy. While our previous studies had indicated that immune response to the transgene product substantially influenced the success of therapy, it is possible that the vector itself may have influenced the severity of immune response. To address this, we propose to assess the potential immunogenicity of six different rAAV serotype vectors in primary human dendritic cells in vitro. In addition to analyzing the character of and examination the potential of modulation of the immune response resulting from therapy, we also propose to characterize the inherent properties of GAA that contribute to elicitation of immune response with the eventual goal of identifying novel modulations that would lead to a less immunogenic, more effective therapeutic product. We will map the antigenic epitopes of the GAA protein and correlate those findings to the structure of the protein by determining the crystal structure of GAA. Understanding the structure-function relationship in the GAA protein would not only allow us to identify regions of antigenicity, but also provide insight into the mechanism of action and potentially the molecular basis of GSD II. Together, these studies will yield important new information in establishing clinically relevant strategies for liver-directed rAAV-mediated gene therapy in general, and for the treatment of GSD II, in particular.

糖原储存疾病II型（GSD II）是由单个基因缺陷引起的原型代谢储存疾病。小鼠模型的可用性提供了一个论坛，以评估基因替代疗法。特别是，我们研究了重组腺相关病毒（RAAV）介导的基因递送酸 - α葡萄糖苷酶（GAA）对GSD II小鼠模型的肝脏定向校正的基因递送。在以前的研究中，我们有 使用RAAV载体显示出高效率在体内基因转移到心脏和骨骼肌。最近，我们通过摄取肝组织过表达而导致的分泌蛋白来校正远端组织（交叉校正）。但是，我们还指出，可以是 所实现的取决于对表达的GAA的体液免疫反应水平。在这项研究中，我们建议扩展我们的研究并检查免疫调节的潜力，以提高RAAV介导的，肝脏指导的基因治疗对GSD II的功效。在我们的最初研究中，我们将评估免疫抑制药物的功效，以防止对RAAV衍生或注入的重组GAA蛋白的免疫反应。有趣的是，像其他人一样 注意到RAAV介导的对治疗转基因的免疫耐受性的某些实例，我们建议通过过继转移研究来表征载体诱导的对GAA的耐受性的机制，以优化基于RAAV的治疗。尽管我们以前的研究表明，对转基因产物的免疫反应显着影响治疗的成功，但媒介本身可能会影响免疫的严重程度 回复。为了解决这个问题，我们建议评估体外原代人树突状细胞中六种不同RAAV血清型载体的潜在免疫原性。除了分析治疗引起的免疫反应的调节的特征和检查的特征外，我们还建议表征GAA的固有特性，这些特性有助于促进免疫反应，并最终识别新的调制，以识别新型调节 导致免疫原性，更有效的治疗产物。我们将通过确定GAA的晶体结构来绘制GAA蛋白的抗原表位，并将这些发现与蛋白质的结构相关联。了解GAA蛋白中的结构功能关系不仅会使我们能够识别抗原性区域，还可以 提供有关作用机理以及GSD II的分子基础的见解。总之，这些研究将产生重要的新信息，以建立肝脏指导的RAAV介导的基因疗法，尤其是治疗GSD II的临床相关策略。