National Institute of Biological Sciences (NIBS), Beijing, China.
Chinese Institute for Brain Research, Beijing, China.
Nat Methods. 2022 Aug;19(8):976-985. doi: 10.1038/s41592-022-01547-7. Epub 2022 Jul 25.
As the resident immune cells in the central nervous system (CNS), microglia orchestrate immune responses and dynamically sculpt neural circuits in the CNS. Microglial dysfunction and mutations of microglia-specific genes have been implicated in many diseases of the CNS. Developing effective and safe vehicles for transgene delivery into microglia will facilitate the studies of microglia biology and microglia-associated disease mechanisms. Here, we report the discovery of adeno-associated virus (AAV) variants that mediate efficient in vitro and in vivo microglial transduction via directed evolution of the AAV capsid protein. These AAV-cMG and AAV-MG variants are capable of delivering various genetic payloads into microglia with high efficiency, and enable sufficient transgene expression to support fluorescent labeling, Ca and neurotransmitter imaging and genome editing in microglia in vivo. Furthermore, single-cell RNA sequencing shows that the AAV-MG variants mediate in vivo transgene delivery without inducing microglia immune activation. These AAV variants should facilitate the use of various genetically encoded sensors and effectors in the study of microglia-related biology.
作为中枢神经系统 (CNS) 中的常驻免疫细胞，小胶质细胞在 CNS 中协调免疫反应并动态塑造神经回路。小胶质细胞功能障碍和小胶质细胞特异性基因的突变与 CNS 的许多疾病有关。开发有效的、安全的转基因载体将有助于小胶质细胞的转染，从而促进小胶质细胞生物学和小胶质细胞相关疾病机制的研究。在这里，我们报告了通过腺相关病毒 (AAV) 衣壳蛋白的定向进化发现了能够通过体外和体内小胶质细胞转导有效传递的 AAV 变体。这些 AAV-cMG 和 AAV-MG 变体能够以高效率将各种遗传有效载荷递送至小胶质细胞，并能够实现足够的转基因表达以支持体内小胶质细胞的荧光标记、Ca 和神经递质成像以及基因组编辑。此外，单细胞 RNA 测序表明，AAV-MG 变体在体内转导转基因时不会诱导小胶质细胞免疫激活。这些 AAV 变体将有助于在小胶质细胞相关生物学研究中使用各种基因编码的传感器和效应器。
