Department of Ophthalmology, University of Pittsburgh, Pittsburgh, United States.
Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, United States.
Elife. 2021 Oct 19;10:e64175. doi: 10.7554/eLife.64175.
Adeno-associated virus (AAV)-mediated gene therapies are rapidly advancing to the clinic, and AAV engineering has resulted in vectors with increased ability to deliver therapeutic genes. Although the choice of vector is critical, quantitative comparison of AAVs, especially in large animals, remains challenging.
Here, we developed an efficient single-cell AAV engineering pipeline (scAAVengr) to simultaneously quantify and rank efficiency of competing AAV vectors across all cell types in the same animal.
To demonstrate proof-of-concept for the scAAVengr workflow, we quantified - with cell-type resolution - the abilities of naturally occurring and newly engineered AAVs to mediate gene expression in primate retina following intravitreal injection. A top performing variant identified using this pipeline, K912, was used to deliver SaCas9 and edit the rhodopsin gene in macaque retina, resulting in editing efficiency similar to infection rates detected by the scAAVengr workflow. scAAVengr was then used to identify top-performing AAV variants in mouse brain, heart, and liver following systemic injection.
These results validate scAAVengr as a powerful method for development of AAV vectors.
This work was supported by funding from the Ford Foundation, NEI/NIH, Research to Prevent Blindness, Foundation Fighting Blindness, UPMC Immune Transplant and Therapy Center, and the Van Sloun fund for canine genetic research.
腺相关病毒 (AAV) 介导的基因疗法正在迅速推向临床,AAV 工程已产生了能够更有效地传递治疗基因的载体。尽管载体的选择至关重要,但在大型动物中,对 AAV 的定量比较仍然具有挑战性。
在这里,我们开发了一种高效的单细胞 AAV 工程流水线 (scAAVengr),可以在同一动物的所有细胞类型中同时定量和对竞争 AAV 载体的效率进行排序。
为了证明 scAAVengr 工作流程的概念验证,我们以细胞类型分辨率量化了在猴眼内注射后,天然存在的和新工程化的 AAV 介导基因表达的能力。使用该流水线鉴定的一种表现最佳的变体 K912,用于递送 SaCas9 并编辑猕猴视网膜中的视蛋白基因,其编辑效率与 scAAVengr 工作流程检测到的感染率相似。然后,scAAVengr 用于在全身注射后鉴定小鼠大脑、心脏和肝脏中表现最佳的 AAV 变体。
这些结果验证了 scAAVengr 是开发 AAV 载体的强大方法。
这项工作得到了福特基金会、NIH/NEI、预防盲症研究、盲症基金会、UPMC 免疫移植和治疗中心以及范斯洛恩犬类遗传研究基金的资助。