Gene therapy: The power of persistence Nearly 50 years after the concept was first proposed, gene therapy is now considered a promising treatment option for several human diseases. The path to success has been long and tortuous. Serious adverse effects were encountered in early clinical studies, but this fueled basic research that led to safer and more efficient gene transfer vectors. Gene therapy in various forms has produced clinical benefits in patients with blindness, neuromuscular disease, hemophilia, immunodeficiencies, and cancer. Dunbar et al. review the pioneering work that led the gene therapy field to its current state, describe gene-editing technologies that are expected to play a major role in the field's future, and discuss practical challenges in getting these therapies to patients who need them. Science, this issue p. eaan4672 BACKGROUND Nearly five decades ago, visionary scientists hypothesized that genetic modification by exogenous DNA might be an effective treatment for inherited human diseases. This “gene therapy” strategy offered the theoretical advantage that a durable and possibly curative clinical benefit would be achieved by a single treatment. Although the journey from concept to clinical application has been long and tortuous, gene therapy is now bringing new treatment options to multiple fields of medicine. We review critical discoveries leading to the development of successful gene therapies, focusing on direct in vivo administration of viral vectors, adoptive transfer of genetically engineered T cells or hematopoietic stem cells, and emerging genome editing technologies. ADVANCES The development of gene delivery vectors such as replication-defective retro viruses and adeno-associated virus (AAV), coupled with encouraging results in preclinical disease models, led to the initiation of clinical trials in the early 1990s. Unfortunately, these early trials exposed serious therapy-related toxicities, including inflammatory responses to the vectors and malignancies caused by vector-mediated insertional activation of proto-oncogenes. These setbacks fueled more basic research in virology, immunology, cell biology, model development, and target disease, which ultimately led to successful clinical translation of gene therapies in the 2000s. Lentiviral vectors improved efficiency of gene transfer to nondividing cells. In early-phase clinical trials, these safer and more efficient vectors were used for transduction of autologous hematopoietic stem cells, leading to clinical benefit in patients with immunodeficiencies, hemoglobinopathies, and metabolic and storage disorders. T cells engineered to express CD19-specific chimeric antigen receptors were shown to have potent antitumor activity in patients with lymphoid malignancies. In vivo delivery of therapeutic AAV vectors to the retina, liver, and nervous system resulted in clinical improvement in patients with congenital blindness, hemophilia B, and spinal muscular atrophy, respectively. In the United States, Food and Drug Administration (FDA) approvals of the first gene therapy products occurred in 2017, including chimeric antigen receptor (CAR)–T cells to treat B cell malignancies and AAV vectors for in vivo treatment of congenital blindness. Promising clinical trial results in neuromuscular diseases and hemophilia will likely result in additional approvals in the near future. In recent years, genome editing technologies have been developed that are based on engineered or bacterial nucleases. In contrast to viral vectors, which can mediate only gene addition, genome editing approaches offer a precise scalpel for gene addition, gene ablation, and gene “correction.” Genome editing can be performed on cells ex vivo or the editing machinery can be delivered in vivo to effect in situ genome editing. Translation of these technologies to patient care is in its infancy in comparison to viral gene addition therapies, but multiple clinical genome editing trials are expected to open over the next decade. OUTLOOK Building on decades of scientific, clinical, and manufacturing advances, gene therapies have begun to improve the lives of patients with cancer and a variety of inherited genetic diseases. Partnerships with biotechnology and pharmaceutical companies with expertise in manufacturing and scale-up will be required for these therapies to have a broad impact on human disease. Many challenges remain, including understanding and preventing genotoxicity from integrating vectors or off-target genome editing, improving gene transfer or editing efficiency to levels necessary for treatment of many target diseases, preventing immune responses that limit in vivo administration of vectors or genome editing complexes, and overcoming manufacturing and regulatory hurdles. Importantly, a societal consensus must be reached on the ethics of germline genome editing in light of rapid scientific advances that have made this a real, rather than hypothetical, issue. Finally, payers and gene therapy clinicians and companies will need to work together to design and test new payment models to facilitate delivery of expensive but potentially curative therapies to patients in need. The ability of gene therapies to provide durable benefits to human health, exemplified by the scientific advances and clinical successes over the past several years, justifies continued optimism and increasing efforts toward making these therapies part of our standard treatment armamentarium for human disease. Three essential tools for human gene therapy. AAV and lentiviral vectors are the basis of several recently approved gene therapies. Gene editing technologies are in their translational and clinical infancy but are expected to play an increasing role in the field. After almost 30 years of promise tempered by setbacks, gene therapies are rapidly becoming a critical component of the therapeutic armamentarium for a variety of inherited and acquired human diseases. Gene therapies for inherited immune disorders, hemophilia, eye and neurodegenerative disorders, and lymphoid cancers recently progressed to approved drug status in the United States and Europe, or are anticipated to receive approval in the near future. In this Review, we discuss milestones in the development of gene therapies, focusing on direct in vivo administration of viral vectors and adoptive transfer of genetically engineered T cells or hematopoietic stem cells. We also discuss emerging genome editing technologies that should further advance the scope and efficacy of gene therapy approaches.

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基因疗法成熟

基因疗法：持久性的力量 在这个概念首次提出近 50 年后，基因疗法现在被认为是治疗多种人类疾病的一种很有前途的选择。成功之路漫长而曲折。在早期的临床研究中遇到了严重的不良反应，但这推动了基础研究，从而产生了更安全、更有效的基因转移载体。各种形式的基因治疗已经为失明、神经肌肉疾病、血友病、免疫缺陷和癌症患者带来了临床益处。邓巴等人。回顾引领基因治疗领域发展到目前状态的开创性工作，描述有望在该领域未来发挥重要作用的基因编辑技术，并讨论将这些疗法带给需要它们的患者的实际挑战。科学，这个问题 p。eaan4672 背景 近五年前，有远见的科学家假设外源 DNA 的基因改造可能是治疗遗传性人类疾病的有效方法。这种“基因治疗”策略提供了理论上的优势，即通过单一治疗可以获得持久且可能治愈的临床益处。尽管从概念到临床应用的旅程漫长而曲折，但基因治疗现在正在为多个医学领域带来新的治疗选择。我们回顾了导致成功基因疗法开发的关键发现，重点是病毒载体的直接体内给药、基因工程 T 细胞或造血干细胞的过继转移，以及新兴的基因组编辑技术。进展 复制缺陷型逆转录病毒和腺相关病毒 (AAV) 等基因递送载体的开发，加上临床前疾病模型中令人鼓舞的结果，导致了 1990 年代初期临床试验的启动。不幸的是，这些早期试验暴露了严重的治疗相关毒性，包括对载体的炎症反应和由载体介导的原癌基因插入激活引起的恶性肿瘤。这些挫折推动了病毒学、免疫学、细胞生物学、模型开发和目标疾病方面的更多基础研究，最终导致了 2000 年代基因疗法的成功临床转化。慢病毒载体提高了基因转移到非分裂细胞的效率。在早期临床试验中，这些更安全、更有效的载体被用于转导自体造血干细胞，从而为免疫缺陷、血红蛋白病以及代谢和储存障碍患者带来临床益处。经工程改造以表达 CD19 特异性嵌合抗原受体的 T 细胞在淋巴恶性肿瘤患者中显示出有效的抗肿瘤活性。治疗性 AAV 载体向视网膜、肝脏和神经系统的体内递送分别导致先天性失明、血友病 B 和脊髓性肌萎缩患者的临床改善。在美国，食品和药物管理局 (FDA) 于 2017 年批准了第一个基因治疗产品，包括用于治疗 B 细胞恶性肿瘤的嵌合抗原受体 (CAR)-T 细胞和用于先天性失明的体内治疗的 AAV 载体。在神经肌肉疾病和血友病方面的有希望的临床试验结果可能会在不久的将来获得更多的批准。近年来，已经开发了基于工程或细菌核酸酶的基因组编辑技术。与只能介导基因添加的病毒载体相比，基因组编辑方法为基因添加、基因消融和基因“校正”提供了精确的手术刀。基因组编辑可以在离体细胞上进行，也可以在体内传递编辑机制以实现原位基因组编辑。与病毒基因添加疗法相比，将这些技术转化为患者护理尚处于起步阶段，但预计未来十年将开展多项临床基因组编辑试验。展望 以数十年的科学、临床和制造进步为基础，基因疗法已经开始改善癌症和各种遗传性遗传病患者的生活。要使这些疗法对人类疾病产生广泛影响，需要与在制造和扩大规模方面具有专业知识的生物技术和制药公司建立合作伙伴关系。许多挑战仍然存在，包括理解和防止整合载体或脱靶基因组编辑引起的基因毒性，将基因转移或编辑效率提高到治疗许多目标疾病所需的水平，防止限制体内施用载体或基因组编辑复合物的免疫反应，并克服制造和监管障碍。重要的是，鉴于迅速的科学进步使生殖系基因组编辑成为现实，必须就生殖系基因组编辑的伦理达成社会共识，而不是假设，问题。最后，支付方、基因治疗临床医生和公司需要共同设计和测试新的支付模式，以促进向有需要的患者提供昂贵但可能治愈的疗法。基因疗法为人类健康提供持久益处的能力，以过去几年的科学进步和临床成功为例，证明了继续乐观并加大努力使这些疗法成为我们人类疾病标准治疗装备的一部分是合理的。人类基因治疗的三个基本工具。AAV 和慢病毒载体是最近批准的几种基因疗法的基础。基因编辑技术处于转化和临床初期，但预计将在该领域发挥越来越大的作用。在经历了近 30 年的挫折后，基因疗法正迅速成为治疗各种遗传性和获得性人类疾病的重要组成部分。遗传性免疫疾病、血友病、眼部和神经退行性疾病以及淋巴癌的基因疗法最近在美国和欧洲取得了批准的药物状态，或预计将在不久的将来获得批准。在这篇综述中，我们讨论了基因疗法发展的里程碑，重点是病毒载体的直接体内给药和基因工程 T 细胞或造血干细胞的过继转移。我们还讨论了新兴的基因组编辑技术，这些技术应该会进一步推进基因治疗方法的范围和有效性。基因疗法正迅速成为治疗各种遗传性和获得性人类疾病的重要组成部分。遗传性免疫疾病、血友病、眼部和神经退行性疾病以及淋巴癌的基因疗法最近在美国和欧洲取得了批准的药物状态，或预计将在不久的将来获得批准。在这篇综述中，我们讨论了基因疗法发展的里程碑，重点是病毒载体的直接体内给药和基因工程 T 细胞或造血干细胞的过继转移。我们还讨论了新兴的基因组编辑技术，这些技术应该会进一步提高基因治疗方法的范围和功效。基因疗法正迅速成为治疗各种遗传性和获得性人类疾病的重要组成部分。遗传性免疫疾病、血友病、眼部和神经退行性疾病以及淋巴癌的基因疗法最近在美国和欧洲取得了批准的药物状态，或预计将在不久的将来获得批准。在这篇综述中，我们讨论了基因疗法发展的里程碑，重点是病毒载体的直接体内给药和基因工程 T 细胞或造血干细胞的过继转移。我们还讨论了新兴的基因组编辑技术，这些技术应该会进一步提高基因治疗方法的范围和功效。