Unraveling the immune response to factor VIII

总体组件 项目总结/摘要 血友病A是最常见的严重先天性出血性疾病。它是由F8基因突变引起的。 导致凝血因子VIII（fVIII）缺乏或完全缺乏的X染色体上的缺陷。电流 血友病患者的治疗是静脉输注血浆衍生或重组FVIII， 预防出血或在出血发生后进行治疗。治疗中最重要的并发症 A型血友病患者的主要症状是产生fVIII的抑制性抗体（抑制剂）。未来的标准- A型血友病的治疗将是基因治疗。在临床前基因治疗研究中， 阻止了对遗传损伤的长期矫正。 我们建议建立一个埃默里因子VIII中心，由一组高度互动的研究人员组成， 多样化的研究技能和对FVIII免疫原性的既定兴趣。核心假设是， FVIII结构中的结构决定簇，包括其聚糖，是其高度免疫原性的原因 行为本提案中的三个项目涉及这些主题，旨在确定 fVIII结构、fVIII糖生物学和fVIII在基因治疗环境中对其免疫原性的影响。在项目1中， 因子VIII的免疫识别的结构基础”，我们寻求鉴定可以被免疫识别的免疫原性结构。 修饰以产生免疫原性较低的FVIII分子。这将通过使用X射线晶体学来实现， 氢氘交换质谱，单粒子负染电镜，表面 等离子体共振光谱和分析超离心以确定FVIII和FVIII的结构 免疫复合物在项目2“因子VIII的免疫生物学”中，研究了因子VIII聚糖的作用和 将确定微生物群对抗-αGal抗体发展对抑制剂形成的影响。另夕h 将评价项目1中表征的fVIII免疫复合物的免疫原性。在项目3中，“小说 用于预防或治疗因子VIII抑制剂的因子VIII技术”， 和免疫反应性的生物工程重组输注产品以及肝定向的AAV和HSC- 将分析定向LV基因治疗衍生的FVIII。关键设计参数 将鉴定肝定向AAV-fVIII基因治疗的免疫原性和抑制剂消除辐射潜力。 此外，非遗传毒性HSC定向LV基因的免疫原性和抑制剂消除潜力 将评估治疗方案。这个项目非常重要，因为它涉及因果机制 的FVIII抑制和修改这些机制的影响，以改善血友病A患者的治疗。

Overall Component Project Summary/Abstract Hemophilia A is the most common severe congenital bleeding disorder. It is caused by mutations in the F8 gene on the X chromosome that lead to deficiency or complete absence of blood coagulation factor VIII (fVIII). Current management of patients with hemophilia is intravenous infusion of either plasma-derived or recombinant fVIII to prevent bleeding or to treat bleeding after it has occurred. The most significant complication in the management of patients with hemophilia A is the development of inhibitory antibodies (inhibitors) to fVIII. The future standard- of-care of hemophilia A will be gene therapy. In preclinical gene therapy studies, the development of inhibitors has prevented long-term correction of the genetic lesion. We propose to create an Emory Factor VIII Center consisting of a group of highly interactive investigators with diverse research skills and an established interest in the immunogenicity of fVIII. The central hypothesis is that structural determinants in fVIII structure, including its glycans, are responsible for its highly immunogenic behavior. The three projects in this proposal address these themes with aims to determine the relationship of fVIII structure, fVIII glycobiology and fVIII in gene therapy settings to its immunogenicity. In Project 1, “The Structural Basis for Immune Recognition of Factor VIII”, we seek to identify immunogenic structures that can be modified to produce a less immunogenic fVIII molecule. This will be accomplished by using X-ray crystallography, hydrogen-deuterium exchange mass spectrometry, single-particle negative-stain electron microscopy, surface plasmon resonance spectroscopy and analytical ultracentrifugation to determine the structure of fVIII and fVIII immune complexes. In Project 2, “The Immunobiology of Factor VIII”, the role of fVIII glycans and the impact of microbiota on anti-αGal antibody development on inhibitor formation will be determined. Additionally, the immunogenicity of fVIII immune complexes characterized in Project 1 will be evaluated. In Project 3, “Novel Factor VIII Technologies for the Prevention or Treatment of Factor VIII Inhibitors”, the molecular composition and immune reactivity of bioengineered recombinant infusion products as well as liver-directed AAV and HSC- directed LV gene therapy derived fVIII will be analyzed. Critical design parameters associated with immunogenicity and inhibitor eradiation potential of liver-directed AAV-fVIII gene therapy will be identified. Additionally, the immunogenicity and inhibitor eradicating potential of non-genotoxic HSC-directed LV gene therapy protocols will be evaluated. This program is highly significant because it addresses causal mechanisms for fVIII inhibition and implications for modifying these mechanisms to improve therapy for hemophilia A patients.