Barriers to achieving efficient gene therapy

实现有效基因治疗的障碍

• 批准号: 8652991
• 负责人: Lili Wang
• 金额: $ 20.35万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8652991
• 关键词: Animal Model; B-Lymphocyte Epitopes; B-Lymphocytes; Binding; Capsid; Cells; Chimera organism; Clinical; Clinical Trials; Cryoelectron Microscopy; Disease; Dose; Engineering; Epitopes; Gene Transfer; Genome engineering; Goals; Hemophilia B; Hepatic; Hepatocyte; Human; Immune; Immune response; Immunity; Inborn Genetic Diseases; Individual; Inherited; Instruction; Learning; Life; Liver; Macaca; Maps; Mediating; Metabolic Diseases; Modeling; Monoclonal Antibodies; Mutagenesis; Mutation; Natural Immunity; Plasmapheresis; Principal Investigator; Resistance; Sampling; Serotyping; Site; Solutions; Structure; Surface; Surveys; T-Cell Activation; T-Lymphocyte; Therapeutic Effect; Transgenes; Tropism; Tyrosine; Variant; adeno-associated viral vector; base; ds-DNA; effective therapy; gene therapy; gene therapy clinical trial; improved; in vivo; multicatalytic endopeptidase complex; neutralizing antibody; nonhuman primate; novel; pre-clinical; preclinical study; transduction efficiency; urea cycle; vector

The goal of this proposal is to explore ways to generate a novel AAV vector to overcome the barrier of pre- existing vector neutralizing antibodies (NAbs) to achieve efficient gene transfer in vivo. In vivo delivery of AAV vectors has shown promise in a variety of pre-clinical and clinical models of inherited disorders. The major challenges to date involve host immune responses and poor transduction efficiency due to limited vector tropism and poor delivery of the vector to the target cell. AAV serotype 8 (AAVS) has been identified as the best Clinical Candidate vector for liver-directed gene transfer and is currenfiy being evaluated in a human clinical trial for gene therapy of hemophilia B. Much is still being learned about host-vector immune interactions such as the effect of innate immunity and activation of T cells and B cells against the vector and its transgene product. One of the most important aspects of host immunity is the impact of neutralizing antibodies (NAb) on transduction efficiency. NAb against the AAV vector capsid results in substantial reduction in transducfion when administered systemically, as demonstrated in preclinical studies in animal models and in human clinical trials. We have characterized the threshold titer of pre-existing NAb that is compromising to AAVS gene transfer in nonhuman primates. Pre-existing NAb fiters in excess of 1:10 substantially diminish hepatocyte transduction at the dose of 3x10^^ genonne copies/kg. Based on our survey in human samples, we predict that 25% of humans in the USA will not be suitable for systemic delivery of AAVS vector. Engineered vectors that can escape neutralization would provide a more general and effective solufion. In this project, we will employ mulfiple approaches guided by AAV structures with the ultimate aim to generate an "AAVS-prime" (AAVS') vector that retains the high liver tropism of AAVS and is more resistant to neutralization in humans. RELEVANCE (See instructions): Many inherited metabolic diseases, such as OTC deficiency, are lacking effective treatments. Adeno- associated vector-mediated hepatic gene therapy has the potential to provide an alternative to cure or treat these life-threatening disorders. This project aims to developing improved vectors to overcome the barriers to achieving efficient therapeutic effects.

该提案的目标是探索生成新型 AAV 载体的方法，以克服预编码的障碍。 现有的载体中和抗体（NAb）可实现体内有效的基因转移。体内递送 AAV 载体在各种遗传性疾病的临床前和临床模型中显示出前景。这 迄今为止的主要挑战涉及宿主免疫反应和由于有限的转导效率而导致的低转导效率。 载体向性和载体向靶细胞的递送不良。 AAV 血清型 8 (AAVS) 已被鉴定 作为肝脏定向基因转移的最佳临床候选载体，目前正在接受评估 血友病 B 基因治疗的人体临床试验。关于宿主载体免疫仍有很多了解 相互作用，例如先天免疫的影响以及 T 细胞和 B 细胞针对载体的激活 及其转基因产物。宿主免疫力最重要的方面之一是中和的影响 抗体（NAb）对转导效率的影响。针对 AAV 载体衣壳的 NAb 会产生大量的结果 动物临床前研究表明，全身给药时转导减少 模型和人体临床试验。我们已经确定了预先存在的 NAb 的阈值滴度，即 损害非人类灵长类动物的 AAVS 基因转移。现有 NAb 适配子超过 1:10 在 3x10^^genonne 拷贝/kg 的剂量下显着减少肝细胞转导。基于我们的 对人类样本的调查显示，我们预测美国 25% 的人不适合进行系统性治疗 AAVS 载体的递送。可以逃脱中和作用的工程载体将提供更通用的方法 和有效的解决方案。在这个项目中，我们将采用以 AAV 结构为指导的多种方法 最终目标是生成“AAVS-prime”（AAVS'）载体，该载体保留了 AAVS 的高肝向性，并且 人类对中和作用更有抵抗力。 相关性（参见说明）： 许多遗传性代谢疾病，例如 OTC 缺乏症，缺乏有效的治疗方法。腺苷- 相关载体介导的肝脏基因疗法有可能提供一种替代治疗方法 这些危及生命的疾病。该项目旨在开发改进的载体以克服障碍 以达到高效的治疗效果。