Schuettrumpf Joerg, Liu Jian-Hua, Couto Linda B, Addya Kathakaly, Leonard Debra G B, Zhen Zhu, Sommer Jürg, Arruda Valder R
The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Mol Ther. 2006 Jun;13(6):1064-73. doi: 10.1016/j.ymthe.2006.03.002. Epub 2006 May 2.
The risk of germline transmission of vector sequences in humans is a major safety concern, because the enrollment of subjects of reproductive age in early-phase clinical trials of gene transfer continues to increase. In a study of adult men with hemophilia B, adeno-associated virus serotype 2 (AAV2) delivered to the liver via the hepatic artery resulted in unexpected transient vector dissemination to the semen. Here we report that intravenous AAV2 injection in rabbits proved a useful model to assess biologic parameters of vector dissemination to the semen. Detectable vector sequences in semen disappeared in a dose-dependent and time-dependent fashion. AAV infectious particles were present only as long as day 4 after injection and were undetectable thereafter. The kinetics of vector clearance was faster in the semen fractions enriched for motile sperm than in the total semen. In addition, increased frequency of semen sampling accelerated the clearance of vector sequences from semen. Long-term follow-up, spanning hundreds of spermatogenesis cycles, showed that there was no recurrence of detectable vector sequences in semen, thus reducing the probability of inadvertent transduction of early spermatogonia not committed to differentiation at the time of vector injection. We conclude that AAV2 presents minimal germline transmission risk for humans.
载体序列在人类中发生种系传播的风险是一个主要的安全问题，因为在基因转移早期临床试验中纳入育龄受试者的情况持续增加。在一项针对成年乙型血友病男性的研究中，通过肝动脉输送到肝脏的2型腺相关病毒（AAV2）导致载体意外短暂播散至精液。在此我们报告，在兔子中静脉注射AAV2证明是评估载体播散至精液的生物学参数的有用模型。精液中可检测到的载体序列以剂量和时间依赖性方式消失。AAV感染性颗粒仅在注射后第4天存在，此后无法检测到。在富含活动精子的精液组分中，载体清除的动力学比在全精液中更快。此外，增加精液采样频率加速了载体序列从精液中的清除。跨越数百个精子发生周期的长期随访表明，精液中未检测到的载体序列没有复发，从而降低了在载体注射时未致力于分化的早期精原细胞被意外转导的可能性。我们得出结论，AAV2对人类的种系传播风险极小。
