Aptamer-programmable adeno-associated viral vectors as a novel platform for cell-specific gene transfer

• Published in: Molecular therapy. Nucleic acids Vol. 31; pp. 383 - 397
• Main Authors: Puzzo, Francesco, Zhang, Chuanling, Powell Gray, Bethany, Zhang, Feijie, Sullenger, Bruce A., Kay, Mark A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 14.03.2023; American Society of Gene & Cell Therapy; Elsevier
• Subjects: adeno-associated virus; aptamers; gene therapy; MT: Delivery Strategies; Original; precision medicine; synthetic biology; vector engineering; synthetic biology; gene therapy; precision medicine; adeno-associated virus; MT: Delivery Strategies; aptamers; vector engineering
• ISSN: 2162-2531; 2162-2531
• DOI: 10.1016/j.omtn.2023.01.007

Adeno-associated viruses (AAVs) are commonly used for in vivo gene therapy. Nevertheless, the wide tropism that characterizes these vectors limits specific targeting to a particular cell type or tissue. Here, we developed new chemically modified AAV vectors (Nε-AAVs) displaying a single site substitution on the capsid surface for post-production vector engineering through biorthogonal copper-free click chemistry. We were able to identify AAV vectors that would tolerate the unnatural amino acid substitution on the capsid without disrupting their packaging efficiency. We functionalized the Nε-AAVs through conjugation with DNA (AS1411) or RNA (E3) aptamers or with a folic acid moiety (FA). E3-, AS1411-, and FA-AAVs showed on average a 3- to 9-fold increase in transduction compared with their non-conjugated counterparts in different cancer cell lines. Using specific competitors, we established ligand-specific transduction. In vivo studies confirmed the selective uptake of FA-AAV and AS1411-AAV without off-target transduction in peripheral organs. Overall, the high versatility of these novel Nε-AAVs might pave the way to tailoring gene therapy vectors toward specific types of cells both for ex vivo and in vivo applications. [Display omitted] The study by Puzzo et al. shows that replacement of AAV capsid amino acids by unnatural amino acids followed by chemical conjugation of a small-molecule ligand RNA or DNA aptamer to the unnatural amino acid can re-target AAV entry into cells.