Eradication of FVIII Inhibitors using Gene-Based Therapy

使用基因疗法根除 FVIII 抑制剂

• 批准号: 8391966
• 负责人: John S. Lollar
• 金额: $ 31.54万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8391966
• 关键词: A Mouse; Address; Animal Model; Animals; Antibodies; Antigen-Antibody Complex; Antigens; Autoimmune Diseases; Biological; Biological Models; CD34 gene; Cells; Clinical; Clinical Treatment; Clinical Trials; Complication; Crohn' s disease; Data; Dependence; Development; Disease; Dose; Engraftment; Epitopes; Family suidae; Goals; Health; Hematopoietic Stem Cell Transplantation; Hemophilia A; Human; Hybrids; Immune; Immune Tolerance; Immune response; Immune system; Immunity; Immunodeficient Mouse; Infusion procedures; Instruction; Laboratories; Methods; Multiple Sclerosis; Mus; Patients; Production; Proteins; Protocols documentation; Recombinants; Refractory; Regimen; Reporting; Rheumatoid Arthritis; Stem cells; Systemic Lupus Erythematosus; Transgenes; Translating; Transplantation; Variant; Whole-Body Irradiation; base; cell type; clinically significant; conditioning; cost; enzyme replacement therapy; gene therapy; genetically modified cells; in vitro activity; inhibitor/antagonist; success; treatment strategy

PROJECT SUMMARY (See instructions): The development of inhibitory antibodies directed against human factor Vlll (h-fVIII) remains the most signiflcant clinical complication associated with the treatment of hemophilia A and is a critical barrier to gene therapy approaches. Not dissimilar to what occurs in the majority of monogenic diseases treated using protein replacement therapy, 20 - 30% of hemophilia A patients develop an immune response to the infused fVIII product that renders treatment ineffective. Therefore, the discovery and development of new methods to induce immune tolerance or hypo-responsiveness are needed. Hematopoietic stem cell transplantation (HSCT) protocols are showing promise in clinical trials for the treatment of a variety of human autoimmune disorders. Furthermore, HSCT combined with gene therapy has been shown, at least in animal models, to facilitate the introduction of and tolerance to neo or allo-antigens, such as those proteins deficient in monogenic diseases like hemophilia A. Our laboratories recently reported that transplantation of geneticallymodified HSCs containing a high-expression porcine (p)-fVIII transgene into hemophilia A mice results in the production of high levels of circulating fVlll activity. None of the recipient mice developed anti-fVlll antibodies following HSCT gene therapy, even in the context of non-myeloablative and non-radiation-based conditioning. Subsequently, we studied HSCT gene therapy in hemophilia A mice harboring anfi-hfVlll inhibitory antibody titers. Even though the majority of mice contained circulating antibodies that cross-reacted with and inhibited p-fVIII activity in vitro, transplantation of genetically-modified HSCs expressing p-fVlll into myeloablated hemophilia A mice restored circulating fVIII activity. Curative p-fVlll activity levels persisted and anti-h-fVIII antibody titers steadily declined throughout the course of the study in all mice. In contrast, the use of non-myeloablative total body irradiation (TBI) was only partially successful in promoting the engraftment of genetically-modified cells and resulted in a delayed reduction of anti-fVIII antibody titers. Therefore, pre-existing immunity presents an additional barrier to HSCT gene therapy. These data suggest that, while HSCT-based gene therapy incorporating a p-fVIII can be utilized successfully for the treatment of patients with refractory anti-hfVIII inhibitors, 1) more aggressive transplant conditioning is necessary to achieve disease correction, 2) the use of an orthologous (or other non-idenfical antigen) transgene product is critical, and 3) enduring tolerance/hyporesponsiveness can be achieved. The focus of this proposal is to develop an HSCT gene therapy strategy for the treatment of hemophilia A when complicated by inhibitors.

项目摘要（请参阅说明）： 针对人因子VLLL（H-FVIII）的抑制性抗体的发展仍然是最多的 与血友病A治疗相关的明显临床并发症，是基因的关键障碍 治疗方法。与大多数使用的单基因疾病中发生的情况不同 蛋白质替代疗法，20-30％的血友病A患者对注入的患者产生免疫反应 FVIII产品使治疗无效。因此，发现和开发新方法 需要诱导免疫耐受性或低反应性。造血干细胞移植 （HSCT）方案在临床试验中显示出对各种人类自身免疫的治疗的希望 疾病。此外，HSCT与基因疗法的结合至少在动物模型中显示为 促进对Neo或Allo抗原的引入和耐受性，例如那些缺乏的蛋白 单基因疾病等血友病A。我们的实验室最近报道了遗传学改良的移植 含有高表达猪（P）-FVIII转基因到血友病A小鼠的HSC导致 产生高水平的循环FVLLL活性。没有一个受体小鼠开发抗FVLLL抗体 遵循HSCT基因治疗，即使在非毛刺和非放射性的背景下 调理。随后，我们研究了具有Anfi-Hfvlll的血友病的HSCT基因治疗 抑制性抗体滴度。即使大多数小鼠含有交叉反应的循环抗体 在体外抑制并抑制P-FVIII活性，将p-fvlll的遗传改性HSC移植到 脊髓脑化的血友病A小鼠恢复了循环的FVIII活性。治愈性P-FVLLL活性水平持续存在 在所有小鼠的整个研究过程中，在整个研究过程中，抗H-FVIII抗体滴度稳步下降。相反， 使用非毛囊全身照射（TBI）仅在促进 植物修饰细胞的植入，导致抗FVIII抗体滴度的延迟减少。 因此，预先存在的免疫力为HSCT基因治疗带来了额外的障碍。这些数据暗示 尽管基于HSCT的基因疗法纳入了P-FVIII，但可以成功地用于治疗 难治性抗HFVIII抑制剂的患者，1）需要更具侵略性的移植调节 实现疾病纠正，2）使用直系同源（或其他非肾抗原）转基因产物的使用是 至关重要的3）可以实现持久的耐受性/不足。该提议的重点是 当抑制剂复杂时，制定了HSCT基因治疗策略，以治疗血友病A。