Novel AAV Capsids and Gene Regulatory Elements for GeneExpression in Microglia

项目摘要： 小胶质细胞是大脑的常驻巨噬细胞，在大脑发育期间承担多种功能， 疾病长期以来，人们都知道阿尔茨海默病（AD）会对大脑的变化做出反应，最近的遗传研究表明， AD发作表明AD风险变异体通常存在于或接近于在AD中特异性表达基因中， 小胶质细胞，表明小胶质细胞在驱动AD中发挥积极作用。此外，小胶质细胞表现出各种 大脑发育过程中的功能，包括突触修剪。基因编码的组成部分， 通过小胶质细胞介导突触修剪的补体系统与精神分裂症有关。 然而，研究小胶质细胞在正常和患病大脑中的作用的一个主要瓶颈是缺乏病毒表达。 快速操纵基因表达的工具。病毒载体也将有利于转基因的研究， 没有动物可用。最后，病毒载体将使研究基因治疗AD的潜力成为可能， 影响小胶质细胞的罕见疾病。然而，虽然小胶质细胞显示出适度的和局部的转导， 在体内，它们对腺相关病毒（AAV）的转导具有抗性，优选的腺相关病毒（AAV）是慢病毒。 由于它们的上级扩散性和极好的安全性，它们被用于神经科学研究和基因治疗。 在这里，我们建议阐明AAV对小胶质细胞转导的障碍，工程化AAV衣壳变体， 能够克服这些障碍，在体内抑制小胶质细胞，并开发新的基因调控元件， 这将使小胶质细胞特异性转基因能够从病毒载体表达。这将是一个合作项目 史蒂文斯和德弗曼实验室之间，结合他们在研究小胶质细胞（史蒂文斯）和 开发新的AAV载体（Deverman）。

Project Summary: Microglia, the resident macrophages of the brain, assume a multitude of functions during brain development and disease. Long known to react to changes in brains affected by Alzheimer’s disease (AD), genetic studies of late- onset AD indicate that AD risk variants are commonly found in or near genes that are specifically expressed in microglia, suggesting that microglia play an active role in driving AD. In addition, microglia exhibit various functions during brain development, including synapse pruning. Genes coding for components of the complement system, which mediates synapse pruning by microglia, have been linked to schizophrenia. However, a major bottleneck in studying the roles of microglia in normal and diseased brains is the lack of viral tools for rapidly manipulating their gene expression. Viral vectors would also benefit studies where transgenic animals are not available. Finally, viral vectors would enable studies on the potential of gene therapy for AD and rare diseases that affect microglia. However, while microglia show modest and localized transduction by lentiviruses in vivo, they are resistant to transduction by adeno-associated viruses (AAVs), the preferred viral vectors used in neuroscience research and gene therapy due to their superior spread and excellent safety profile. Here we propose to elucidate the barriers to microglia transduction by AAVs, engineer AAV capsid variants that are able to overcome these barriers and transduce microglia in vivo, and develop novel gene regulatory elements that will enable microglia-specific transgene expression from viral vectors. This will be a collaborative project between the Stevens and Deverman labs, combining their expertise in studying microglia (Stevens) and in developing novel AAV vectors (Deverman).