Efficient in vivo base editing via single adeno-associated viruses with size-optimized genomes encoding compact adenine base editors.

Nat Biomed Eng
Authors
Abstract

The viral delivery of base editors has been complicated by their size and by the limited packaging capacity of adeno-associated viruses (AAVs). Typically, dual-AAV approaches based on trans-splicing inteins have been used. Here we show that, compared with dual-AAV systems, AAVs with size-optimized genomes incorporating compact adenine base editors (ABEs) enable efficient editing in mice at similar or lower doses. Single-AAV-encoded ABEs retro-orbitally injected in mice led to editing efficiencies in liver (66%), heart (33%) and muscle (22%) tissues that were up to 2.5-fold those of dual-AAV ABE8e, and to a 93% knockdown (on average) of human PCSK9 and of mouse Pcsk9 and Angptl3 in circulation, concomitant with substantial reductions of plasma cholesterol and triglycerides. Moreover, three size-minimized ABE8e variants, each compatible with single-AAV delivery, collectively offer compatibility with protospacer-adjacent motifs for editing approximately 82% of the adenines in the human genome. ABEs encoded within single AAVs will facilitate research and therapeutic applications of base editing by simplifying AAV production and characterization, and by reducing the dose required for the desired level of editing.

Year of Publication
2022
Journal
Nat Biomed Eng
Date Published
2022 Jul 28
ISSN
2157-846X
DOI
10.1038/s41551-022-00911-4
PubMed ID
35902773
Links
Grant list
UG3AI150551 / U.S. Department of Health & Human Services | NIH | National Institute of Allergy and Infectious Diseases (NIAID)
U01AI142756 / U.S. Department of Health & Human Services | NIH | National Institute of Allergy and Infectious Diseases (NIAID)
R35GM118062 / U.S. Department of Health & Human Services | NIH | National Institute of General Medical Sciences (NIGMS)
RM1HG009490 / U.S. Department of Health & Human Services | NIH | National Human Genome Research Institute (NHGRI)
Liu Investigatorship / Howard Hughes Medical Institute (HHMI)
Liu Grant / Bill and Melinda Gates Foundation (Bill & Melinda Gates Foundation)