Blocking the immune response to Helper-dependent adenovirus vector for Hemophilia

描述(申请人提供)：项目名称。阻断辅助依赖腺病毒载体的免疫反应以改进血友病A基因治疗。项目摘要。血友病A(HA)是由凝血因子VIII(FVIII)缺乏引起的一种常见的凝血功能障碍。治疗的主流是用重组人FVIII进行替代治疗。然而，由于昂贵的费用、获得治疗的机会以及抗体形成的抑制，患者继续遭受重大的长期发病率和死亡率的困扰。我们开发了一种优化的辅助依赖型腺病毒基因载体(HDAds)系统，使我们能够在小动物和大动物模型上实现分泌型和细胞内转基因的长期表达，而不会出现载体的慢性毒性和持久性。然而，急性毒性仍然是临床翻译的障碍。为了克服这一点，我们建议开发表达SOCS1和/或编码TLR9抑制物序列的免疫抑制HDAd。然而，由于先天免疫系统的巨大冗余性，我们建议开发血液滤过形式的辅助治疗，这种辅助治疗已经在临床上有益于在脓毒症的情况下去除急性免疫成分。在非人类灵长类动物的安全性研究中，我们将结合血液滤过和改进的免疫抑制HDADS。最终，我们将把这种方法应用于小鼠和犬血清白蛋白缺乏的临床前治疗。为了应对FVIII治疗的潜在获得性免疫反应，我们将与FVIII共表达von Willebrand因子(VWF)。通过这些研究，我们将解决血友病基因治疗中的三个重要问题A i)我们能降低对HDADS的先天免疫反应吗？Ii)能否提高FVIII在HA模型中的表达效果？Iii)在辅助血液滤过的非人灵长类动物模型中，我们能降低先天免疫反应吗？这一应用的总体目标是建立安全有效的辅助依赖腺病毒载体(HDAds)与血液滤过相结合的HA基因治疗，该基因治疗可以很容易地翻译到临床上，用于未来的临床试验。在这个指导阶段(K99)，我将通过结合先天免疫反应的细胞自主免疫抑制、非细胞自主体液因子的物理清除和FVIII的稳定因子来提高HDAd治疗HA的治疗指数。指导阶段(K99)将在Brendan Lee博士的指导下在贝勒医学院进行。在随后的独立研究阶段(R00)，我将把这种混合HDADS应用于犬HA，为临床研究做准备。我还将评估血液滤过辅助的混合HDADS注射在非人类灵长类动物中的治疗效果。 公共卫生相关性：项目叙述。血友病A(HA)是由凝血因子VIII(FVIII)缺乏引起的一种常见的凝血功能障碍。治疗的主流是用重组人FVIII进行替代治疗。然而，由于昂贵的费用、获得治疗的机会以及抗体形成的抑制，患者继续遭受重大的长期发病率和死亡率的困扰。这项应用的总体目标是建立安全有效的辅助依赖型腺病毒载体的HA基因治疗，当它与新的物理干预(如血液滤过)相结合时，可以很容易地翻译到临床上，用于未来的临床试验。

DESCRIPTION (provided by applicant): Project Title. Blocking the immune response to Helper-dependent adenovirus vector for improved Hemophilia A gene therapy. Project Abstract. Hemophilia A (HA) is a common disorder of coagulation caused by deficiency of factor VIII (FVIII). The mainstay of treatment has been replacement therapy with recombinant human FVIII. However, because of high cost, access to therapy, and inhibitory antibody formation, patients continue to suffer from significant long-term morbidity and mortality. Our development of an optimized helper-dependent adenoviral gene vector (HDAds) system has enabled us to achieve long term expression of both secreted and intracellular transgenes without chronic toxicity and persistence of vector using both small and large animal models. However, acute toxicity remains an obstacle to clinical translation. To overcome this, we propose to develop immune suppressive HDAds expressing SOCS1 and/or coding TLR9 inhibitor sequences. However, because of the great redundancy of the innate immune system, we propose to develop adjunctive therapy in the form of hemofiltration that has already to be clinically-beneficial to remove the acute immune components in the context of sepsis. We will combine hemofiltration with improved immunosuppressive HDAds in safety studies in nonhuman primates. Ultimately, we will apply this approach to the preclinical treatment of FVIII deficiency in murine and canine HA. To address the potential adaptive immune response to FVIII therapy, we will co-express von Willebrand Factor (vWF) with FVIII. With these studies, we will address three important questions in genetic therapy for hemophilia A i) Can we decrease the innate immune response to HDAds? ii) Can we improve the efficacy of FVIII expression in HA model? iii) Can we decrease the innate immune response in nonhuman primate model with adjunctive hemofiltration? The overall goal of this application is to establish the safe and effective HA gene therapy with helper-dependent adenoviral vectors (HDAds) combined with hemofiltration that can be readily translated in the clinical arena for future clinical trials. During this mentored phase (K99), I will improve the therapeutic index of HDAd for HA therapy by combining cell autonomous immune suppression of the innate immune response, physical clearance of non-cell autonomous humoral factors, and stabilization factor of FVIII,. The mentored phase (K99) will occur at Baylor College of Medicine under the guidance of Dr. Brendan Lee. In the subsequent independent investigator phase (R00), I will apply this hybrid HDAds to canine HA in preparation for clinical studies. I will also evaluate the therapeutic effect of hemofiltration-assisted hybrid HDAds injection in nonhuman primates. PUBLIC HEALTH RELEVANCE: Project Narrative. Hemophilia A (HA) is a common disorder of coagulation caused by deficiency of factor VIII (FVIII). The mainstay of treatment has been replacement therapy with recombinant human FVIII. However, because of high cost, access to therapy, and inhibitory antibody formation, patients continue to suffer from significant long-term morbidity and mortality. The overall goal of this application is to establish the safe and effective HA gene therapy with helper-dependent adenovirus vector which, when combined with novel physical interventions (such as hemofiltration) that can be readily translated in the clinical arena for future clinical trials.