RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, 01605, USA.
Tessera Therapeutics, Inc., 200 Sidney Street, Cambridge, MA, 02139, USA.
Nat Commun. 2021 Nov 1;12(1):6267. doi: 10.1038/s41467-021-26518-y.
Adeno-associated virus (AAV) vectors are important delivery platforms for therapeutic genome editing but are severely constrained by cargo limits. Simultaneous delivery of multiple vectors can limit dose and efficacy and increase safety risks. Here, we describe single-vector, ~4.8-kb AAV platforms that express Nme2Cas9 and either two sgRNAs for segmental deletions, or a single sgRNA with a homology-directed repair (HDR) template. We also use anti-CRISPR proteins to enable production of vectors that self-inactivate via Nme2Cas9 cleavage. We further introduce a nanopore-based sequencing platform that is designed to profile rAAV genomes and serves as a quality control measure for vector homogeneity. We demonstrate that these platforms can effectively treat two disease models [type I hereditary tyrosinemia (HT-I) and mucopolysaccharidosis type I (MPS-I)] in mice by HDR-based correction of the disease allele. These results will enable the engineering of single-vector AAVs that can achieve diverse therapeutic genome editing outcomes.
腺相关病毒 (AAV) 载体是治疗性基因组编辑的重要递送平台,但受到载体容量限制。同时递送多个载体可能会限制剂量和疗效,并增加安全风险。在这里,我们描述了一种 ~4.8kb 的单载体 AAV 平台,它可以表达 Nme2Cas9 和两个用于片段缺失的 sgRNA,或者一个带有同源定向修复 (HDR) 模板的 sgRNA。我们还使用抗 CRISPR 蛋白来生产可以通过 Nme2Cas9 切割自我失活的载体。我们进一步引入了一种基于纳米孔的测序平台,该平台旨在对 rAAV 基因组进行分析,并作为载体均一性的质量控制措施。我们证明,这些平台可以通过 HDR 校正疾病等位基因,有效地治疗两种疾病模型(I 型遗传性酪氨酸血症 (HT-I) 和黏多糖贮积症 I 型 (MPS-I))。这些结果将使单载体 AAV 的工程设计能够实现多样化的治疗性基因组编辑结果。