Current Challenges and Future Directions in Recombinant AAV-Mediated Gene Therapy of Duchenne Muscular Dystrophy

Abstract

Various characteristics of adeno-associated virus (AAV)-based vectors with long-term safe expression have made it an exciting transduction tool for clinical gene therapy of Duchenne muscular dystrophy (DMD). Although host immune reactions against the vector as well as transgene products were detected in some instances of the clinical studies, there have been promising observations. Methods of producing AAV vectors for considerable in vivo experimentation and clinical investigations have been developed and a number of studies with AAV vector-mediated muscle transduction were attempted. Notably, an intravenous limb perfusion transduction technique enables extensive transgene expression in the skeletal muscles without noticeable adverse events. Furthermore, cardiac transduction by the rAAV9-microdystrophin would be promising to prevent development of cardiac dysfunction. Recent achievements in transduction technology suggest that long-term transgene expression with therapeutic benefits in DMD treatment would be achieved by the rAAV-mediated transduction strategy with an adequate regimen to regulate host immune response.

Precise Correction of the Dystrophin Gene in Duchenne Muscular Dystrophy Patient Induced Pluripotent Stem Cells by TALEN and CRISPR-Cas9

“…The large size of the dystrophin gene hampers the delivery of therapeutic cDNA for gene augmentation. Therefore, the delivery of truncated microdystrophin or microutrophin by an adeno-associated viral (AAV) vector ( Okada and Takeda, 2013 ), lentiviral vector ( Pichavant et al., 2011 ), or Sleeping Beauty transposon ( Filareto et al., 2013 ) has been investigated for DMD gene therapy. However, restoration of the full-length dystrophin protein remains challenging.…”

Bone-Targeted Alkaline Phosphatase Treatment of Mandibular Bone and Teeth in Lethal Hypophosphatasia via an scAAV8 Vector

“…In addition, we used the MCK promoter as a safer and more practical approach because the skeletal muscles are easily accessible and have a large capacity for protein production. 26 TNALP was expressed specifically in the muscle by scAAV8-MCK-TNALP-D 10 -mediated muscle transduction, and then it went to circulation. 13 High levels of ALP activity were restricted to the muscle (means ± SD, TNALP-D 10 versus WT; 0.164 ± 0.084 versus 0.007 ± 0.003 U/mg, p < 0.01, at day 90), and ALP activity was not remarkable in the heart, lung, or liver using the MCK promoter, which was the same experiment system of this study.…”

基于&lt;bold&gt;CRISPR/Cas9&lt;/bold&gt;基因编辑技术的人类遗传疾病基因治疗相关研究进展

“…这些突变包括Dmd基因的小规 模碱基缺失或部分外显子的大规模丢失, 最终导致转 录过程中可读框的移码, 产生功能残缺的肌萎缩蛋白 http://engine.scichina.com/doi/10.1360/N052017-00169 (dystrophin) [41] . 虽然包括AAV传输 [42] 、慢病毒传输 [41] 以及"睡美人"转座子系统(sleeping beauty transposon) [43] 等在内的手段已经被用于DMD基因治疗的相关研究, 但Dmd基因较大的序列长度在很大程度上阻碍了治疗 性基因的有效递送. 因此, 力争恢复全长肌萎缩蛋白 编码基因序列的治疗努力仍然极具挑战 [44] .…”