Nathwani A C, Davidoff A, Hanawa H, Zhou J F, Vanin E F, Nienhuis A W
Division of Experimental Hematology, Department of Hematology/ Oncology, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
Blood. 2001 Mar 1;97(5):1258-65. doi: 10.1182/blood.v97.5.1258.
Long-term expression of coagulation factor IX (FIX) has been observed in murine and canine models following administration of recombinant adeno-associated viral (rAAV) vectors into either the portal vein or muscle. These studies were designed to evaluate factors that influence rAAV-mediated FIX expression. Stable and persistent human FIX (hFIX) expression (> 22 weeks) was observed from 4 vectors after injection into the portal circulation of immunodeficient mice. The level of expression was dependent on promoter with the highest expression, 10% of physiologic levels, observed with a vector containing the cytomegalovirus (CMV) enhancer/beta-actin promoter complex (CAGG). The kinetics of expression after injection of vector particles into muscle, tail vein, or portal vein were similar with hFIX detectable at 2 weeks and reaching a plateau by 8 weeks. For a given dose, intraportal administration of rAAV CAGG-FIX resulted in a 1.5-fold or 4-fold higher level of hFIX compared to tail vein or intramuscular injections, respectively. Polymerase chain reaction analysis demonstrated predominant localization of the rAAV FIX genome in liver and spleen after tail vein injection with a higher proportion in liver after portal vein injection. Therapeutic levels of hFIX were detected in the majority of immunocompetent mice (21 of 22) following intravenous administration of rAAV vector without the development of anti-hFIX antibodies, but hFIX was not detected in 14 immunocompetent mice following intramuscular administration, irrespective of strain. Instead, neutralizing anti-hFIX antibodies were detected in all the mice. These observations may have important implications for hemophilia B gene therapy with rAAV vectors.
在将重组腺相关病毒（rAAV）载体经门静脉或肌肉给药后，已在小鼠和犬模型中观察到凝血因子IX（FIX）的长期表达。这些研究旨在评估影响rAAV介导的FIX表达的因素。在将4种载体注射到免疫缺陷小鼠的门静脉循环后，观察到稳定且持久的人FIX（hFIX）表达（>22周）。表达水平取决于启动子，含有巨细胞病毒（CMV）增强子/β-肌动蛋白启动子复合物（CAGG）的载体观察到最高表达水平，为生理水平的10%。将载体颗粒注射到肌肉、尾静脉或门静脉后，表达动力学相似，hFIX在2周时可检测到，并在8周时达到平台期。对于给定剂量，与尾静脉或肌肉注射相比，经门静脉给予rAAV CAGG-FIX分别导致hFIX水平高1.5倍或4倍。聚合酶链反应分析表明，尾静脉注射后rAAV FIX基因组主要定位于肝脏和脾脏，门静脉注射后肝脏中的比例更高。在大多数免疫活性小鼠（22只中的21只）静脉注射rAAV载体后检测到治疗水平的hFIX，且未产生抗hFIX抗体，但在14只免疫活性小鼠肌肉注射后未检测到hFIX，无论品系如何。相反，在所有小鼠中均检测到中和性抗hFIX抗体。这些观察结果可能对rAAV载体治疗血友病B具有重要意义。
