Shenzhen Key Laboratory for Molecular Biology of Neural Development, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Shenzhen-Hong Kong Institute of Brain Science, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Shenzhen Key Laboratory for Molecular Biology of Neural Development, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Shenzhen-Hong Kong Institute of Brain Science, Shenzhen 518055, China.
Neurosci Lett. 2022 Jul 27;784:136746. doi: 10.1016/j.neulet.2022.136746. Epub 2022 Jun 16.
Recombinant adeno-associated viruses (rAAVs) are widespread vectors in neuroscience research. However, the nearly absent retrograde access to projection neurons hampers their application in functional dissection of neural circuits and in therapeutic intervention. Recently, engineering of the AAV2 capsid has generated an AAV variant, called rAAV2-retro, with exceptional retrograde functionality. This variant comprises a 10-mer peptide insertion at residue 587 and two point mutations (LADQDYTKTA + V708I + N382D). Here, we evaluated the contribution of each mutation to retrograde transport in prefrontal cortex -striatum and amygdala-striatum pathways, respectively. Results showed that disruption of the inserted decapeptide almost completely abolishes the retrograde access to neurons projecting to striatum. Eliminating N382D has little effect on the retrograde functionality. Restoring another mutation V708I, however, even improves its performance in amygdala-striatum pathway. Parallel comparison within same animal further confirms this conflicting effect of V708I. These results demonstrate a pivotal role of decapeptide insertion in gaining the capacity of retrograde transport and highlight a neural circuit-dependent contribution of V708I. It suggests constant and custom engineering of rAAV2-retro might be required to tackle the challenge of tremendous neuronal heterogeneity.
重组腺相关病毒 (rAAV) 是神经科学研究中广泛使用的载体。然而，几乎不存在逆行进入投射神经元的能力限制了它们在神经回路功能解析和治疗干预中的应用。最近，对 AAV2 衣壳的工程改造产生了一种称为 rAAV2-retro 的 AAV 变体，具有出色的逆行功能。该变体在残基 587 处包含一个 10 肽插入，以及两个点突变 (LADQDYTKTA + V708I + N382D)。在这里，我们评估了每个突变对前额叶皮层 -纹状体和杏仁核 -纹状体通路中逆行运输的贡献。结果表明，插入的十肽的破坏几乎完全消除了逆行进入投射到纹状体的神经元的能力。消除 N382D 对逆行功能几乎没有影响。然而，恢复另一个突变 V708I 甚至可以提高其在杏仁核 -纹状体通路中的性能。在同一动物中的平行比较进一步证实了 V708I 的这种相互矛盾的影响。这些结果表明十肽插入在获得逆行运输能力方面起着关键作用，并突出了 V708I 的神经回路依赖性贡献。这表明需要对 rAAV2-retro 进行持续和定制的工程改造，以应对巨大神经元异质性的挑战。
