Brunetti-Pierri Nicola, Ng Thomas, Iannitti David A, Palmer Donna J, Beaudet Arthur L, Finegold Milton J, Carey K Dee, Cioffi William G, Ng Philip
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Hum Gene Ther. 2006 Apr;17(4):391-404. doi: 10.1089/hum.2006.17.391.
Helper-dependent adenoviral vectors (HDAds) are attractive vectors for liver-directed gene therapy because they can mediate sustained, high-level transgene expression without chronic toxicity. However, high vector doses are required to achieve efficient hepatic transduction by systemic delivery because of a nonlinear dose response. Unfortunately, such high doses result in systemic vector dissemination and dose-dependent acute toxicity with potentially severe and lethal consequences. We hypothesize that the threshold to efficient hepatic transduction may be circumvented by delivering the vector into the surgically isolated liver via the portal vein. Total hepatic isolation was achieved by occluding hepatic inflow from the portal vein and hepatic artery and by occluding hepatic venous outflow at the inferior vena cava. We demonstrate in nonhuman primates that this approach resulted in significantly higher efficiency hepatic transduction with reduced systemic vector dissemination compared with systemic intravascular delivery. This method of delivery was associated with transient acute toxicity, the severity of which was variable. Importantly, stable, high levels of transgene expression were obtained for at least 665 days for one baboon and for at least 560 days for two baboons with no evidence of long-term toxicity.
辅助依赖型腺病毒载体（HDAds）是用于肝脏定向基因治疗的有吸引力的载体，因为它们可以介导持续的高水平转基因表达且无慢性毒性。然而，由于非线性剂量反应，通过全身递送实现有效的肝脏转导需要高载体剂量。不幸的是，如此高的剂量会导致载体在全身扩散，并产生剂量依赖性急性毒性，可能带来严重和致命的后果。我们假设，通过门静脉将载体递送至手术分离的肝脏，可以规避有效肝脏转导的阈值。通过阻断门静脉和肝动脉的肝血流以及阻断下腔静脉的肝静脉流出，实现了全肝分离。我们在非人灵长类动物中证明，与全身血管内递送相比，这种方法可显著提高肝脏转导效率，并减少载体在全身的扩散。这种递送方法与短暂的急性毒性相关，其严重程度各不相同。重要的是，一只狒狒至少665天、两只狒狒至少560天获得了稳定、高水平的转基因表达，且没有长期毒性的证据。
