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.

项目摘要弗里德里希（Friedreich）的共济失调（FRDA）是一种多系统的常染色体隐性障碍主要是由纯合的GAA重复扩张突变引起的 Frataxin（FXN）基因的第一内含子导致其表达降低。 Frataxin是与铁代谢有关的线粒体蛋白。 FRDA的特征是共济失调，神经变性，肌肉无力和心肌病。没有治疗这种致命疾病。我们测试了一种由野生型（WT）组成的疾病的新疗法 Y8GR小鼠中的造血干和祖细胞（HSPC）移植 FRDA的模型。该模型仅表示突变的人FXN变换，从而模仿了FRDA患者和临床的转录缺乏表型。使用此策略的前提来自我们以前的数据 Cystinosis，一种多系统性溶酶体储存障碍，HSPC检索通过将HSPC分化为组织内的巨噬细胞的移植通过隧道纳米管（TNT）转移符号蛋白酶素的溶酶体向相邻病细胞。 TNT也可以转移线粒体，因此我们假设这是策略也可以治疗FRDA。这种疗法的效果超出了我们的期望 FRDA作为神经系统，肌肉和心脏并发症已完全纠正单次输注后移植后长达7个月（经测试的最新时间点）致命辐照的Y8GR小鼠中的HSPC。鉴于发病率和死亡率的高风险与同种异体HSPC移植相关，我们的目标是开发 FRDA的自体HSPC基因治疗方法。因为过表达 Frataxin有毒，我们将测试两种不同的方法以进行体内基因校正和恢复基因在HSPC中的生理表达。一种策略是引入 HSPC在其短形式的控制下，人FXN（HFXN）cDNA 内源性启动子使用慢病毒载体。由于大多数患者携带GAA 重复扩展，第二种方法是使用CRISPR/CAS9介导的基因在HSPC中删除此突变的编辑方法。人和鼠FRDA HSPCS 将使用。最后，我们还将确定HSPC移植反向的能力先前存在并发症。这项工作代表了第一个自体基因校正的 HSPC移植治疗策略的FRDA，为A奠定了基础此策略的临床应用。