Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Biomaterials. 2018 Sep;176:71-83. doi: 10.1016/j.biomaterials.2018.05.041. Epub 2018 May 26.
The adeno-associated virus (AAV) vector has been used in preclinical and clinical trials of gene therapy for central nervous system (CNS) diseases. One of the biggest challenges of effectively delivering AAV to the brain is to surmount the blood-brain barrier (BBB). Herein, we identified several potential BBB shuttle peptides that significantly enhanced AAV8 transduction in the brain after a systemic administration, the best of which was the THR peptide. The enhancement of AAV8 brain transduction by THR is dose-dependent, and neurons are the primary THR targets. Mechanism studies revealed that THR directly bound to the AAV8 virion, increasing its ability to cross the endothelial cell barrier. Further experiments showed that binding of THR to the AAV virion did not interfere with AAV8 infection biology, and that THR competitively blocked transferrin from binding to AAV8. Taken together, our results demonstrate, for the first time, that BBB shuttle peptides are able to directly interact with AAV and increase the ability of the AAV vectors to cross the BBB for transduction enhancement in the brain. These results will shed important light on the potential applications of BBB shuttle peptides for enhancing brain transduction with systemic administration of AAV vectors.
腺相关病毒 (AAV) 载体已被用于中枢神经系统 (CNS) 疾病基因治疗的临床前和临床试验。将 AAV 有效递送至大脑的最大挑战之一是克服血脑屏障 (BBB)。在此，我们鉴定了几种潜在的 BBB 穿梭肽，它们在全身性给药后可显著增强 AAV8 在大脑中的转导，其中最佳的是 THR 肽。THR 对 AAV8 脑转导的增强作用呈剂量依赖性，神经元是 THR 的主要靶标。机制研究表明，THR 直接与 AAV8 病毒颗粒结合，增加其穿过内皮细胞屏障的能力。进一步的实验表明，THR 与 AAV 病毒颗粒的结合不干扰 AAV8 的感染生物学，并且 THR 竞争性地阻止转铁蛋白与 AAV8 结合。总之，我们的研究结果首次表明，BBB 穿梭肽能够直接与 AAV 相互作用，增加 AAV 载体穿过 BBB 的能力，从而增强大脑中的转导。这些结果将为利用 BBB 穿梭肽增强全身性给予 AAV 载体后的大脑转导提供重要启示。
