Hematopoietic Stem Cell Gene Therapy for Friedreich's ataxia

造血干细胞基因治疗弗里德赖希共济失调

基本信息

批准号：
9635234
负责人：
Stephanie Cherqui
金额：
$ 34.34万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9635234
关键词：
15 year old Age Allogenic Applications Grants Ataxia Autologous Biochemical CD34 gene CRISPR/Cas technology Cardiac Cardiomyopathies Cell Therapy Cells Clinical Trials Complementary DNA Cystinosis Data Development Disease Engraftment Exhibits Foundations Friedreich Ataxia Future Gene Delivery Gene Expression Genes Genetic Transcription Hematopoietic stem cells Hereditary Disease Histologic Human Infusion procedures Introns Investigational Drugs Lead Lentivirus Vector Life Lysosomes Mediating Microglia Mitochondria Mitochondrial Proteins Modeling Molecular Morbidity - disease rate Mus Muscle Muscle Cells Muscle Weakness Mutate Mutation Nanotubes Nerve Degeneration Neurologic Neurons Onset of illness Pathology Patients Peptide Elongation Factor 1 Phase Phenotype Physiological Proteins Risk Sensory Stem cell transplant Symptoms Testing Therapeutic Effect Time Tissues Transgenes Transplantation Treatment Efficacy Wheelchairs Work clinical application clinical phenotype clinical translation curative treatments expectation frataxin gene correction gene therapy high risk in vitro testing in vivo iron metabolism macrophage mortality mouse model novel therapeutics overexpression prevent promoter restoration success treatment strategy

项目摘要

Project Summary Friedreich’s ataxia (FRDA) is a multi-systemic autosomal recessive disorder that is predominantly caused by an homozygous GAA repeat expansion mutation within the first intron of the frataxin (FXN) gene leading to a decrease of its expression. Frataxin is a mitochondrial protein involved in iron metabolism. FRDA is characterized by ataxia, neurodegeneration, muscle weakness, and cardiomyopathy. There is no treatment for this lethal disease. We tested a new therapy for this disease consisting in wildtype (WT) hematopoietic stem and progenitor cell (HSPC) transplantation in the Y8GR mouse model of FRDA. This model expresses exclusively the mutated human FXN transgene, thus mimicking the transcriptional deficiency seen in FRDA patients and the clinical phenotype. The premise for using this strategy came from our previous data on cystinosis, a multi-systemic lysosomal storage disorder, which was rescued by HSPC transplantation via differentiation of the HSPCs into macrophages within tissues and transfer of cystinosin-bearing lysosomes via tunneling nanotubes (TNTs) to the adjacent diseased cells. TNTs can also transfer mitochondria, thus we hypothesized that this strategy could also treat FRDA. This therapy worked quite beyond our expectation in FRDA as the neurologic, muscular and cardiac complications were completely corrected up to 7 months post-transplantation (latest time point tested) after a single infusion of HSPCs in lethally irradiated Y8GR mice. Given the high risk of morbidity and mortality associated with allogeneic HSPC transplantation, our objective is to develop an autologous HSPC gene therapy approach for FRDA. Because overexpression of the frataxin is toxic, we will test two different approaches to ex vivo gene-correct and restore a physiologic expression of the gene in the HSPCs. One strategy will be to introduce in HSPCs the human FXN (hFXN) cDNA under the control of a short form of its endogenous promoter using a lentivirus vector. As most of the patients carry a GAA repeat expansion, the second approach will be to use a CRISPR/Cas9-mediated gene editing approach to remove this mutation in HSPCs. Human and murine FRDA HSPCs will be used. Finally, we will also determine the ability of HSPC transplantation to reverse preexisting complications. This work represents the first autologous gene-corrected HSPC transplantation treatment strategy for FRDA and builds the foundation for a clinical application of this strategy.

项目概要弗里德赖希共济失调 (FRDA) 是一种多系统常染色体隐性遗传病，主要是由纯合 GAA 重复扩增突变引起 Frataxin (FXN) 基因的第一个内含子导致其表达减少。 FRDA 是一种参与铁代谢的线粒体蛋白，其特征是共济失调，神经退行性疾病、肌肉无力和心肌病尚无治疗方法。我们测试了一种针对这种疾病的新疗法，其中包括野生型（WT）。 Y8GR 小鼠造血干细胞和祖细胞 (HSPC) 移植 FRDA 模型该模型仅表达突变的人类 FXN 转基因，从而模仿了 FRDA 患者和临床中观察到的转录缺陷使用该策略的前提来自我们之前的数据。胱氨酸沉积症，一种多系统溶酶体贮积症，由 HSPC 挽救通过将 HSPC 分化为组织内的巨噬细胞进行移植通过隧道纳米管（TNT）将携带胱氨酸的溶酶体转移到邻近的 TNT 也可以转移线粒体，因此我们率先提出了这一点。该策略也可以治疗 FRDA，这种疗法的效果远远超出了我们的预期。 FRDA 彻底纠正了神经、肌肉和心脏并发症单次输注后最多 7 个月（测试的最后时间点）鉴于发病率和死亡率的高风险，经致死照射的 Y8GR 小鼠中的 HSPC。与同种异体 HSPC 移植相关，我们的目标是开发一种由于 FRDA 的过度表达，自体 HSPC 基因治疗方法。 frataxin 是有毒的，我们将测试两种不同的方法来进行离体基因校正和恢复一种策略是在 HSPC 中引入该基因的生理表达。 HSPC 是人类 FXN (hFXN) cDNA，受其短形式的控制使用慢病毒载体的内源启动子，因为大多数患者携带 GAA。重复扩增，第二种方法是使用 CRISPR/Cas9 介导的基因编辑方法消除人类和小鼠 FRDA HSPC 中的这种突变。最后，我们还将确定HSPC移植的逆转能力。这项工作代表了第一个自体基因校正。 FRDA的HSPC移植治疗策略并为未来的治疗奠定基础该策略的临床应用。