Ancestral library identifies conserved reprogrammable liver motif on AAV capsid

Eric Zinn; Carmen Unzu; Pauline F Schmit; Heikki T Turunen; Nerea Zabaleta; Julio Sanmiguel; Allegra Fieldsend; Urja Bhatt; Cheikh Diop; Erin Merkel; Rakesh Gurrala; Bryan Peacker; Christopher Rios; Kathleen Messemer; Jennifer Santos; Reynette Estelien; Eva Andres-Mateos; Amy J Wagers; Christopher Tipper; Luk H Vandenberghe

doi:10.1016/j.xcrm.2022.100803

Ancestral library identifies conserved reprogrammable liver motif on AAV capsid

Cell Rep Med. 2022 Nov 15;3(11):100803. doi: 10.1016/j.xcrm.2022.100803. Epub 2022 Nov 2.

Authors

Eric Zinn¹, Carmen Unzu¹, Pauline F Schmit¹, Heikki T Turunen¹, Nerea Zabaleta¹, Julio Sanmiguel¹, Allegra Fieldsend¹, Urja Bhatt¹, Cheikh Diop¹, Erin Merkel¹, Rakesh Gurrala¹, Bryan Peacker², Christopher Rios², Kathleen Messemer², Jennifer Santos¹, Reynette Estelien¹, Eva Andres-Mateos¹, Amy J Wagers³, Christopher Tipper¹, Luk H Vandenberghe⁴

Affiliations

¹ Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Mass Eye and Ear, Boston, MA, USA; Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; The Broad Institute of Harvard and MIT, Cambridge, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA.
² Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA 02115, USA.
³ Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA 02115, USA; Joslin Diabetes Center, Boston, MA 02215, USA.
⁴ Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Mass Eye and Ear, Boston, MA, USA; Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; The Broad Institute of Harvard and MIT, Cambridge, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA. Electronic address: luk_vandenberghe@meei.harvard.edu.

Abstract

Gene therapy is emerging as a modality in 21st-century medicine. Adeno-associated viral (AAV) gene transfer is a leading technology to achieve efficient and durable expression of a therapeutic transgene. However, the structural complexity of the capsid has constrained efforts to engineer the particle toward improved clinical safety and efficacy. Here, we generate a curated library of barcoded AAVs with mutations across a variety of functionally relevant motifs. We then screen this library in vitro and in vivo in mice and nonhuman primates, enabling a broad, multiparametric assessment of every vector within the library. Among the results, we note a single residue that modulates liver transduction across all interrogated models while preserving transduction in heart and skeletal muscles. Moreover, we find that this mutation can be grafted into AAV9 and leads to profound liver detargeting while retaining muscle transduction-a finding potentially relevant to preventing hepatoxicities seen in clinical studies.

Keywords: AAV9; ASR; Anc80; adeno-associated virus; ancestral sequence reconstruction; capsid; gene therapy; hepatotoxicity; hepatotropism; library; liver toggle.

Publication types

Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural

MeSH terms

Animals
Capsid Proteins / genetics
Capsid* / metabolism
Dependovirus / genetics
Genetic Vectors* / genetics
Liver / metabolism
Mice

Substances

Capsid Proteins

Grants and funding

P30 EY003790/EY/NEI NIH HHS/United States