Novel gene therapy strategies for Canavan disease

卡纳万病的新型基因治疗策略

• 批准号: 9145787
• 负责人: Guangping Gao
• 金额: $ 47.27万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9145787
• 关键词: Acetyltransferase; Address; Affect; Antigen-Presenting Cells; Applications Grants; Area; Ashkenazim; Aspartic Acid; Aspartoacylase; Biodistribution; Blood - brain barrier anatomy; Brain; Canavan Disease; Capsid; Central Nervous System Diseases; Cessation of life; Childhood; Clinical; Clinical Research; Codon Nucleotides; DNA cassette; Data; Defect; Demyelinations; Dependovirus; Development; Disease; Dose; Ethnic group; Foundations; Functional disorder; Future; Gene Delivery; Gene Expression; Gene Transfer; Generations; Genes; Genome; Head; Immunity; Inherited; Intervention; Intravenous; Kidney Diseases; Knockout Mice; Lead; Macrocephaly; Mediating; Metabolic; MicroRNAs; Mitochondria; Modeling; Mus; Muscle hypotonia; Mutation; NAT1 gene; Neurodegenerative Disorders; Neurons; Oligodendroglia; Patients; Peripheral; Permeability; Phenotype; Population; Prevalence; Recombinant adeno-associated virus (rAAV); Recombinants; Reporting; Research; Retinal Diseases; Role; Route; Safety; Seroprevalences; Serotyping; Spinal Cord; Swelling; Testing; Therapeutic; Tissues; Toxic effect; Transduction Gene; Treatment Efficacy; Work; adeno-associated viral vector; base; brain parenchyma; cell type; design; disease phenotype; effective therapy; follower of religion Jewish; gene correction; gene replacement therapy; gene therapy; immunotoxicity; improved; infancy; intravenous injection; leukodystrophy; meetings; motor disorder; mouse model; myelination; neuropathology; novel; novel strategies; patient population; postnatal; prevent; promoter; repaired; research clinical testing; success; therapeutic gene; therapy outcome; transduction efficiency; transgene expression; treatment strategy; vector; white matter

DESCRIPTION (provided by applicant): Canavan disease (CD) is a rare, inherited, and fatal, childhood leukodystrophy caused by autosomal recessive mutations in the aspartoacylase gene (ASPA). Although CD has been found in a wide range of ethnic groups, it is especially prevalent in the Ashkenazi Jewish population, affecting one in 6,400 - 13,500 people in this group. ASPA deficiency in Canavan patients leads to accumulation of N-Acetyl-Aspartic Acid (NAA), resulting in swelling and spongy degeneration of white matter in the brain. The clinical manifestations of this fatal disease includ psychomotor retardation, hypotonia, macrocephaly, head lag, and early death. NAA is synthesized in the mitochondria of neurons by N-acetyltransferase (NAT1) and hydrolyzed in oligodendrocytes (OLs) by ASPA. Pathogenic mechanism(s) of ASPA deficiency in the CNS and contributions of ASPA deficits in PTs to the pathophysiology of CD are not well studied. Currently, there is no effective clinical intervention available for CD. ASPA gene replacement therapy is an attractive strategy for the treatment of CD. Earlier gene therapy efforts based on the first generation of AAV serotype 2-derived vector offered no clinical benefit. That was likely due to inadequate transduction efficiency of rAAV2 and limitations of localized intraparenchymal vector delivery. Recent advances in AAV vectorology produced some novel recombinant AAVs (rAAVs), such as rAAV9 reported by Kaspar et al., and rAAVrh.8 and rh.10 identified by our lab, that are highly efficient in transducing large areas of the brain and spinal cord by crossing the blood-brain-barrier (BBB) after intravenous (IV) injection. Here, we hypothesize that using these novel vectors and route of administration, we can develop safe, effective, and sustained gene therapy strategies that will correct the metabolic defect, alleviate the disease phenotype, and prolong survival of CD mice without causing significant toxicity. Specifically, this project will further our understanding of the pathophysiology of CD, particularly in the PTs and the mechanism of rAAV-mediated CD gene therapy after intravenous delivery. We will compare the BBB permeability between wild type (Wt) and ASPA Knockout (ASPA-/-) mice, and define the latest therapeutic window for CD. We will optimize the transgene cassette to express hASPA more efficiently and safely. We will compare our 3 lead vectors (i.e. rAAV9, rh.8, and rh.10) in ASPA-/- mice for minimum effective dose, the latest therapeutic window, long lasting therapeutic outcomes, immunotoxicity, and biodistribution profiles. To facilitate future clinical development, we will also compare these 3 vectors for sero- prevalence in the CD patient population and study impact of pre-existing immunity on CNS gene therapy by adoptively transferring capsid immunities to ASPA-/- mice. These proposed studies will significantly advance our current understanding of CD, and serve as the basis for the development of safe and effective rAAV gene therapeutics for CD patients.

描述（由申请人提供）： Canavan病（CD）是一种罕见，遗传和致命的儿童白细胞营养不良，这是由Aspartoacylase基因（ASPA）中常染色体隐性突变引起的。尽管在广泛的族裔中发现了CD，但在Ashkenazi犹太人口中尤其普遍，影响了该组中的6,400-13,500人。 Canavan患者的ASPA缺乏会导致N-乙酰基天冬氨酸（NAA）的积累，从而导致大脑中白质的肿胀和海绵状变性。这种致命疾病的临床表现包括心理运动迟缓，肌张力低下，大脑，头部滞后和早亡。 NaA由N-乙酰基转移酶（NAT1）在神经元的线粒体中合成，并由ASPA在少突胶质细胞（OLS）中水解。 ASPA缺乏症的致病机制在PT中的ASPA缺陷对CD的病理生理学的贡献尚未得到很好的研究。目前，CD尚无有效的临床干预措施。 ASPA基因替代疗法是治疗CD的有吸引力的策略。基于第一代AAV血清型2衍生载体的早期基因治疗工作没有任何临床益处。这可能是由于RAAV2的转导效率不足以及局部核内载体递送的局限性。 AAV载体学的最新进展产生了一些新型的重组AAV（RAAVS），例如Kaspar等人报道的RAAV9，以及我们实验室确定的Raavrh.8和Rh.10，它们在跨越血脑度 - 甲壳机（BBB）的大脑和脊髓中非常有效，在脑和脊柱中均高效。在这里，我们假设使用这些新颖的载体和给药途径，我们可以制定安全，有效和持续的基因治疗策略，这些策略将纠正代谢缺陷，减轻疾病表型，并延长CD小鼠的存活而不会引起明显的毒性。具体而言，该项目将进一步了解CD的病理生理学，尤其是在静脉输送后RAAV介导的CD基因治疗的机理中。我们将比较野生型（WT）和ASPA敲除（ASPA - / - ）小鼠之间的BBB渗透性，并定义CD的最新治疗窗口。我们将优化转基因盒子，以更有效，安全地表达HASPA。我们将比较ASPA - / - 小鼠中的3个铅矢量（即RAAV9，RH.8和RH.10）的最低有效剂量，最新的治疗窗口，持久的治疗结果，免疫毒性，免疫毒性和生物分布谱。为了促进未来的临床发展，我们还将比较CD患者人群中血清患病率的这三个载体，并研究了先前的免疫对CNS基因治疗的影响，通过将衣壳免疫转移到ASPA - / - 小鼠中。这些拟议的研究将显着提高我们当前对CD的理解，并作为为CD患者开发安全有效的RAAV基因疗法的基础。