Davis Adam S, Federici Thais, Ray William C, Boulis Nicholas M, OʼConnor Deirdre, Clark K Reed, Bartlett Jeffrey S
‡Gene Therapy Center and ¶Battelle Center for Mathematical Medicine, The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio; §Department of Neurosurgery, Emory University, Atlanta, Georgia; ‖Department of Pediatrics, College of Medicine and Public Health and #Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine and Public Health, The Ohio State University Columbus, Ohio; **Calimmune, Inc, Tucson, Arizona.
Neurosurgery. 2015 Feb;76(2):216-25; discussion 225. doi: 10.1227/NEU.0000000000000589.
After injection into muscle and peripheral nerves, a variety of viral vectors undergo retrograde transport to lower motor neurons. However, because of its attractive safety profile and durable gene expression, adeno-associated virus (AAV) remains the only vector to have been applied to the human nervous system for the treatment of neurodegenerative disease. Nonetheless, only a very small fraction of intramuscularly injected AAV vector arrives at the spinal cord.
To engineer a novel AAV vector by inserting a neuronal targeting peptide (Tet1), with binding properties similar to those of tetanus toxin, into the AAV1 capsid.
Integral to this approach was the use of structure-based design to increase the effectiveness of functional capsid engineering. This approach allowed the optimization of scaffolding regions for effective display of the foreign epitope while minimizing disruption of the native capsid structure. We also validated an approach by which low-titer tropism-modified AAV vectors can be rescued by particle mosaicism with unmodified capsid proteins.
Importantly, our rationally engineered AAV1-based vectors exhibited markedly enhanced transduction of cultured motor neurons, diminished transduction of nontarget cells, and markedly superior retrograde delivery compared with unmodified AAV1 vector.
This approach promises a significant advancement in the rational engineering of AAV vectors for diseases of the nervous system and other organs.
多种病毒载体注入肌肉和周围神经后会逆行运输至下运动神经元。然而，由于腺相关病毒（AAV）具有吸引人的安全性和持久的基因表达，它仍然是唯一已应用于人类神经系统治疗神经退行性疾病的载体。尽管如此，肌肉注射的AAV载体仅有极小一部分能到达脊髓。
通过将具有与破伤风毒素相似结合特性的神经元靶向肽（Tet1）插入AAV1衣壳，构建一种新型AAV载体。
该方法的核心是利用基于结构的设计来提高功能性衣壳工程的有效性。这种方法能够优化支架区域，以有效展示外源表位，同时尽量减少对天然衣壳结构的破坏。我们还验证了一种方法，即通过与未修饰的衣壳蛋白进行颗粒镶嵌来拯救低滴度嗜性修饰的AAV载体。
重要的是，与未修饰的AAV1载体相比，我们合理设计的基于AAV1的载体在培养的运动神经元中转导明显增强，在非靶细胞中转导减少，并且逆行递送明显更优。
这种方法有望在用于神经系统和其他器官疾病的AAV载体合理工程方面取得重大进展。
