Improving AAV-based gene therapy for Krabbe Disease

改进基于 AAV 的克拉伯病基因疗法

基本信息

批准号：
10653237
负责人：
Gregory J Heller
金额：
$ 5.27万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10653237
关键词：
3 year old Adult Affect Aftercare Age Animals Architecture Behavioral Biochemical Birth Brain Capsid Proteins Catabolism Cell membrane Cells Cessation of life Characteristics Clinical Clinical Trials Complementary DNA DNA Data Demyelinations Dependovirus Deterioration Development Developmental Delay Disorders Diffuse Disease Disease Progression Dose Effectiveness Elderly Enzymes Episome Failure to Thrive Fluorescent in Situ Hybridization Genes Globoid cell leukodystrophy Goals Hematopoietic Stem Cell Transplantation Histologic Histopathology Immunohistochemistry Impairment Infant Inherited Intrathecal Injections Investigation Lesion Life Life Expectancy Longevity Measures Mendelian disorder Mission Modality Modification Mus Mutation Neonatal Nerve Degeneration Neurons Oligodendroglia Paralysed Pathologic Patients Protocols documentation Psychosine Quality of life Recurrent disease Research Personnel Signal Pathway Teenagers Testing Therapeutic Time Tissues Treatment Efficacy Treatment Protocols United States National Institutes of Health Viral Genome Wild Type Mouse adeno-associated viral vector aged burden of illness cell type chronic neurologic disease clinically relevant design dosage end of life exhaustion experimental study functional restoration galactosylceramidase gene therapy immunoreaction improved intravenous injection leukodystrophy mouse model neuropathology oligodendrocyte precursor postnatal preclinical trial prevent stem cells success treatment duration vector viral DNA white matter

项目摘要

Abstract Krabbe’s Disease (KD) is a rare inherited leukodystrophy caused by mutations in the GALC gene encoding the lysosomal enzyme, galactosylceramidase (GALC). Lack of functional GALC leads to global demyelination and neurodegeneration. Untreated KD presents in infants as developmental delay and regression, failure to thrive, and ultimately death by 2-3 years of age. KD is treated with hematopoietic stem cell transplantation (HSCT) which slows the progression of disease and prolongs life expectancy into the teenage years, but it is not a cure. Adeno-associated viruses (AAV) have been utilized successfully as gene therapy treatment vectors in numerous pre-clinical and clinical trials. The initial success of AAV gene therapy in diseases primarily affecting neuronal cells led to investigations of their efficacy in monogenic diseases affecting multiple cells types such as KD. The Bongarzone lab previously developed a treatment protocol using AAV9- GALC to correct the deficiency in the Twitcher murine model of KD. This treatment completely prevented disease development for the first 6-8 months of life, such that AAV-treated mice were nearly indistinguishable from wild-type mice. Despite these promising results, our study also revealed a slow decline in treatment efficacy over time, including development of disease signs and focal demyelinating plaques in mice of advanced age; similar findings have been noted by other investigators as well. No alternative modifications to improve gene therapy have been proposed thus far. The overarching goal of this application is to establish whether gene therapy efficacy is declining due to exhaustion of AAV DNA in the adult brain and how to optimize gene therapy treatment efficacy and duration in Twitcher mice. As AAV-GALC DNA exists as a non-replicating extra-chromosomal episome after entering a cell, we hypothesize the decline in treatment efficacy is caused by loss of therapeutic vector in replicating cells, particularly oligodendrocyte precursors, in the Twitcher brain, which leads to a decrease in the average AAV- GALC episomes per cell over time. This hypothesis will be investigated by treating mice shortly after birth with AAV9-GALC at decreasing dosages and then observing how long the treatment is efficacious based on clinical score, survival, as well as biochemical and histological analyses. We will then examine if redosing utilizing oligodendrocyte targeted AAV (AAV-001) later in life, but prior to disease sign onset, delays or prevents development of disease signs. Finally, we will determine if utilizing AAV-001 singly will increase the efficacy and duration of treatment in comparison to AAV9. This study is important because we need to better understand what happens to episomal AAV DNA long term before attempting to use AAV based therapies to treat KD patients. Furthermore, our findings will have the intrinsic impact of better characterizing how episomal AAV DNA behaves in similar monogenic disorders.

抽象的 Krabbe病（KD）是由GALC基因突变引起的罕见遗传性白细胞营养不良编码溶酶体酶，半乳糖酰胺酶（GALC）。缺乏功能性galc导致全球脱髓鞘和神经退行性。未经治疗的KD呈现在婴儿中，作为发育延迟和回归，未能成长，最终死亡2-3岁。 KD用造血茎治疗细胞移植（HSCT）减慢疾病的发展并延长预期寿命十几岁，但这不是治愈的。腺相关病毒（AAV）已成功用作基因在许多临床前和临床试验中的治疗治疗载体。 AAV基因疗法在疾病主要影响神经元细胞的疾病导致研究其在影响的单基因疾病中的有效性多种细胞类型，例如KD。 Bongarzone Lab先前使用AAV9-制定了治疗方案 galc纠正KD的Twitcher鼠模型中的缺陷。这种治疗完全阻止了生命的头6-8个月的疾病发展，因此AAV治疗的小鼠几乎无法区分来自野生型小鼠。尽管有这些承诺结果，但我们的研究还显示治疗缓慢下降随着时间的流逝，功效，包括疾病体征的发展和小鼠小鼠斑块斑块高龄;其他研究人员也注意到了类似的发现。没有其他修改到目前为止，已经提出了改善基因疗法。此应用的总体目标是确定基因治疗效率是否由于成人大脑中AAV DNA的耗尽以及如何优化基因治疗治疗效率和持续时间抽搐的老鼠。作为AAV-GALC DNA作为非复制外染色体发作的存在细胞，我们假设治疗效率的下降是由复制细胞中热量丧失引起的，特别是在抽搐大脑中的少突胶质细胞前体，导致平均AAV-的降低随着时间的推移，每个细胞的galc促成。该假设将通过与小鼠出生后不久进行研究 AAV9-GALC减少剂量，然后根据临床观察治疗有效多长时间评分，生存以及生化和组织学分析。然后，我们将检查是否正在使用少突胶质细胞在生命之后针对AAV（AAV-001），但在疾病征兆发作之前，延迟或预防疾病体征的发展。最后，我们将确定使用AAV-001是否会单独提高效率与AAV9相比，治疗持续时间。这项研究很重要，因为我们需要更好在尝试使用基于AAV的疗法之前，请了解长期偶发AAV DNA会发生什么治疗KD患者。此外，我们的发现将具有更好地表征偶发性的固有影响 AAV DNA在相似的单基因疾病中的表现。