Developing gene therapy strategies to treat alpha thalassemia

开发治疗α地中海贫血的基因治疗策略

• 批准号: 10545021
• 负责人: Tippi Mackenzie
• 金额: $ 71.1万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10545021
• 关键词: Address; Adult; Affect; Alleles; Binding; Biological Assay; Birth; Blood Transfusion; CRISPR screen; Caring; Cell Differentiation process; Cell Transplantation; Cells; Chronic; Chronic Disease; Clinic; Clinical; Clinical Trials; Clustered Regularly Interspaced Short Palindromic Repeats; Collaborations; Compensation; Data; Disease; Dissociation; Embryo; Engraftment; Ensure; Erythrocytes; Erythroid; Erythropoiesis; First Pregnancy Trimester; Frequencies; Gene Deletion; Gene Mutation; Genes; Globin; Grant; Guide RNA; Health; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Hemoglobin; Hemoglobin H; Hemoglobinopathies; High Pressure Liquid Chromatography; Human; Immigration; Immunodeficient Mouse; In Vitro; Initiator Codon; Institution; International; Intrauterine Blood Transfusion; Length; Lentivirus Vector; Mediating; Medical; Mendelian disorder; Morbidity - disease rate; Mus; Mutate; Neurological outcome; Nucleic Acid Regulatory Sequences; Outcome; Oxygen; PTPRC gene; Patients; Pattern; Phase I/II Clinical Trial; Production; Proteins; Regimen; Registries; Safety; Scheme; Severity of illness; Site; Specificity; Stem cell transplant; Testing; Toxic effect; Transfusion; Transgenes; Transplantation; Work; alpha Globin; alpha thalassemia major; alpha-Thalassemia; beta Globin; beta Thalassemia; derepression; design; experimental study; fetal; first-in-human; functional restoration; gamma Globin; gene replacement; gene therapy; genome editing; hematopoietic stem cell differentiation; improved; in utero; in vivo; innovation; insertion/deletion mutation; iron chelation therapy; postnatal; pre-clinical; reconstitution; repaired; restoration; southeast Asian; treatment strategy; vector; zeta Globin

ABSTRACT Alpha-thalassemia is one of the most common monogenic diseases in the world; while the carrier frequency is highest in those with South East Asian heritage, there is an expanding health burden in the US due to immigration patterns. Although the most severe form of disease, α-thalassemia major (ATM, in which all four alpha-globin genes are deleted), was formerly often lethal in utero, numerous patients are now surviving to birth after intrauterine blood transfusions, often with excellent neurologic outcomes. However, these patients have a severe chronic disease that requires monthly transfusions or a stem cell transplantation after birth. Patients with a three-gene mutation (such as those with Hemoglobin H-Constant Spring, HbH-CS) can also have severe disease requiring chronic transfusions. While several gene therapy treatments have been developed for patients with β-thalassemia, there are no such therapies for patients with the most severe forms of α-thalassemia, indicating a major unmet medical need. Due to the similarity to β-thalassemia—lack of functional hemoglobin tetramers and formation of toxic globin aggregates in absence of the corresponding binding partner—we believe we can adapt gene therapy strategies that have successfully corrected β-thalassemia in the clinic into analogous approaches for correction of α-thalassemia. These strategies include: 1) CRISPR/AAV- mediated genome editing to replace a copy of β-globin with an α-globin transgene (Aim 1, conducted by Drs. Matthew Porteus and Kyle Cromer at Stanford); 2) Lentiviral delivery of an α-globin cassette with erythroid-specific expression (Aim 2, conducted by Dr. Donald Kohn at UCLA); and 3) CRISPR- mediated de-repression of ζ-globin, the embryonic precursor to α-globin (Aim 3, conducted by Drs. Tippi MacKenzie and Bruce Conklin at UCSF). Our multi-institutional team has been actively collaborating to develop these strategies and the preliminary data presented in this grant. All three independent strategies will be developed in vitro and assessed based on their ability to normalize the globin chain imbalance and restore functional hemoglobin tetramers to α-thalassemia-derived HSCs (obtained from patients with ATM and HbH-CS cared for at UCSF). Furthermore, primary and secondary mouse transplantation experiments will be performed to ensure that edited HSCs retain their ability to engraft and reconstitute hematopoietic lineages in vivo. The expected outcome of the proposed work is a significant advancement toward a universal cure for α-thalassemia by generating substantial pre-clinical data (for one or more approaches) that may be developed into an IND with the FDA for an innovative first-in-human phase I/II clinical trial for ex vivo correction of this disease.

抽象的 α-甲性甲性疾病是世界上最常见的单基因疾病之一。而载体 在东南亚遗产的人中，频率最高，健康燃烧不断扩大 由于移民模式，美国。虽然是最严重的疾病形式，但α-丘脑贫血主要 （ATM，其中所有四个α-珠蛋白基因均被删除），以前在子宫内经常致命，许多 现在，患者在宫内输血后生日生日，通常具有出色的神经系统 结果。但是，这些患者患有严重的慢性疾病，需要每月输血 或出生后的干细胞移植。患有三基因突变的患者（例如 血红蛋白H-Constant Spring，HBH-CS）也可能患有严重的疾病，需要慢性输血。 虽然已经针对β-丘脑贫血的患者开发了几种基因治疗，但是 对于具有最严重形式的α-甲性甲性疾病的患者没有这种疗法 医疗需求。由于与β-丘脑贫血的相似性 - 功能性血红蛋白四聚体和 在没有相应的结合伴侣的情况下，有毒球蛋白聚集体的形成 - 我们相信我们 可以适应已成功纠正临床中β-硫代甲基贫血的基因治疗策略 校正α-甲性贫血的类似方法。这些策略包括：1）CRISPR/AAV-- 介导的基因组编辑，用α-珠蛋白转化代替β-珠蛋白的副本（AIM 1，进行 由Drs。斯坦福大学的Matthew Porteus和Kyle Cromer）； 2）慢病毒递送的α-珠蛋白盒 用红细胞特异性表达（AIM 2，由UCLA的Donald Kohn博士进行）； 3）crispr- ζ-Globin的介导去抑制，ζ-Globin是α-珠蛋白的胚胎前体（AIM 3，由DRS进行。 UCSF的Tippi Mackenzie和Bruce Conklin）。我们的多机构团队一直积极 合作制定这些策略和本赠款中介绍的初步数据。这三个 独立策略将在体外制定，并根据其正常化的能力进行评估 球蛋白链的不平衡和恢复功能性血红蛋白四聚体至α-丘陵降级的HSC （从UCSF受到ATM和HBH-CS患者的速度获得）。此外，主要和 将进行次级小鼠移植实验，以确保编辑的HSC保留其 能够在体内植入和重建造血谱系的能力。预期的结果 拟议的工作是通过产生α-丘脑贫血的普遍治疗的重大进步 大量的临床前数据（对于一种或多种方法）可能会与 FDA进行了创新的人类第一期I/II临床试验，用于对该疾病的体内校正。