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: 10345618
• 负责人: Tippi Mackenzie
• 金额: $ 72.36万
• 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/10345618
• 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 Data; Clinical Trials; Clustered Regularly Interspaced Short Palindromic Repeats; Data; Disease; Dissociation; Embryo; Ensure; Erythrocytes; Erythroid; Erythropoiesis; First Pregnancy Trimester; Frequencies; 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; 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; Repression; Safety; Scheme; Severity of illness; Site; Specificity; Stem cell transplant; Testing; Toxic effect; Transfusion; Transgenes; Transplantation; Work; alpha Globin; alpha thalassemia major; alpha-Thalassemia; base; beta Globin; beta Thalassemia; design; experimental study; fetal; first-in-human; 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.

摘要 α-地中海贫血是世界上最常见的单基因疾病之一;而携带者 具有东南亚血统的人的发病率最高，但健康负担不断扩大 美国由于移民模式。虽然α-重型地中海贫血是最严重的疾病形式， (ATM，其中所有四个α-珠蛋白基因被删除），以前在子宫内往往是致命的，许多 患者在宫内输血后存活到出生，通常具有良好的神经功能， 结果。然而，这些患者患有严重的慢性病，需要每月输血 或者出生后进行干细胞移植有三个基因突变的患者（如 血红蛋白H恒定弹簧，HbH-CS）也可以有严重的疾病，需要慢性输血。 虽然已经为β-地中海贫血患者开发了几种基因疗法治疗， 最严重的α-地中海贫血患者没有此类治疗，这表明 医疗需求。由于与β-地中海贫血相似--缺乏功能性血红蛋白四聚体， 在缺乏相应的结合伴侣的情况下形成有毒的珠蛋白聚集体-我们相信， 可以将临床上成功纠正β地中海贫血的基因治疗策略应用于 用于校正α-地中海贫血的类似方法。这些策略包括：1）CRISPR/AAV- 介导的基因组编辑，以用α-珠蛋白转基因替换β-珠蛋白的拷贝（Aim 1，进行 斯坦福大学的Matthew Porteus和凯尔克罗默博士）; 2）α-珠蛋白盒的慢病毒递送 具有红系特异性表达（Aim 2，由UCLA的Donald Kohn博士进行）;和 介导的α-珠蛋白（α-珠蛋白的胚胎前体）的去阻遏（Aim 3，由Drs. 加州大学旧金山分校的蒂皮·麦肯齐和布鲁斯·康克林）。我们的多机构团队一直积极 合作开发这些战略和本赠款中提供的初步数据。所有三 将在体外开发独立的策略，并根据其使细胞正常化， 珠蛋白链失衡并恢复α-地中海贫血衍生HSC的功能性血红蛋白四聚体 （从在UCSF接受治疗的ATM和HbH-CS患者中获得）。此外，主要和 将进行二次小鼠移植实验以确保编辑的HSC保留它们的 移植和重建造血谱系的能力。的预期成果 拟议的工作是一个重大的进步，朝着普遍治愈α-地中海贫血， 可开发为IND的大量临床前数据（一种或多种方法）， FDA批准了一项创新的首次人体I/II期临床试验，用于这种疾病的体外矫正。