Bioengineering of a Stent-Graft for Gene Therapy

描述（由申请人提供）： 覆膜支架是一种由金属支架支撑的聚合物膜组成的导管，使用导管技术将金属支架放置在血管中。我们用基因工程改造了血管平滑肌细胞（SMC），并将它们放置在专门设计用于保护SMC细胞免受植入创伤的支架移植物上。我们发现这些基因工程细胞存活并增殖，并且基因表达在很长一段时间内保持在高水平，这表明这种新的基因治疗策略将基因产物直接输送到血液中的可行性。本项目的目的是探索是否可以使用充满基因工程SMC的支架移植物来递送功能性因子IX（F.IX）以治疗血友病B。血友病B是由于凝血因子IX缺乏引起的X连锁出血素质。血友病是基因治疗的理想模型，因为不需要精确调控和组织特异性转基因表达。我们将使用血友病狗模型来研究生物工程支架移植物用于基因治疗的可行性。我们假设血管内F.使用充满逆转录病毒转导的SMC的支架移植物的F.IX将提供以治疗水平递送F.IX以纠正凝血缺陷的机会。我们将首先确定使用导管技术将生物工程支架植入血友病B犬的主动脉后，转基因产物犬F.IX可以产生多长时间和多少。我们将通过植入覆膜支架的长度调节F.IX的产生水平。然后，我们将确定是否分泌F。在这些水平的X可以通过测量凝血参数来改善血友病犬的凝血缺陷。还将检查宿主对转基因产物犬F.IX的免疫应答。该项目的成果将直接应用于血友病以及其他血液和血管疾病的治疗。

DESCRIPTION (provided by applicant): A stent-graft is a conduit composed of a polymer membrane supported by a metal stent that is placed in a vessel using catheter technology. We have genetically engineered vascular smooth muscle cells (SMC) and placed them on a stent graft that was specifically designed to shelter the SMC cells from implantation trauma. We found that these genetically engineered cells survived and proliferated and that gene expression was maintained at high levels over a long period, indicating the feasibility of this new gene therapy strategy to deliver the gene product directly into the bloodstream. The objective of this project is to explore whether a stent-graft suffused with genetically engineered SMC can be used to deliver functional Factor IX (F.IX) to treat hemophilia B. Hemophilia B is an X-linked bleeding diathesis resulting from a deficiency of blood coagulation factor IX. Hemophilia is an ideal model for gene therapy because precise regulation and tissue-specific transgene expression are not required. We will use a hemophilic dog model to study the feasibility of bioengineering a stent graft for gene therapy. We hypothesize that the intravascular delivery of F. IX using a stent-graft suffused with retrovirally transduced SMC will offer the opportunity for delivery of F.IX at a therapeutic level to correct the coagulation defect. We will first determine how long and how much of the transgene product canine F.IX can be produced from the bioengineered stent grafts after being implanted into the aorta of a hemophilia B dog using catheter technology. We will modulate the level of F.IX production by the length of the implanted stent graft. Then, we will determine whether the secreted F. X at these levels can ameliorate the coagulation defect in a hemophilic dog by measuring coagulation parameters. The host immune response to the transgene product canine F.IX will also be examined. The outcome of the project will have direct applications in the treatment of hemophilia as well as other blood and vascular disorders.