2. Academic Validation
  3. GPR108 Is a Highly Conserved AAV Entry Factor

GPR108 Is a Highly Conserved AAV Entry Factor

  • Mol Ther. 2020 Feb 5;28(2):367-381. doi: 10.1016/j.ymthe.2019.11.005.
Amanda M Dudek 1,  Nerea Zabaleta 1,  Eric Zinn 1,  Sirika Pillay 2,  James Zengel 2,  Caryn Porter 3,  Jennifer Santos Franceschini 1,  Reynette Estelien 1,  Jan E Carette 2,  Guo Ling Zhou 3,  Luk H Vandenberghe 4
Affiliations

Affiliations

  • 1 Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Mass Eye and Ear, Boston, MA, USA; Ocular Genomics Institute, Mass Eye and Ear, Boston, MA, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
  • 2 Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
  • 3 Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA.
  • 4 Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Mass Eye and Ear, Boston, MA, USA; Ocular Genomics Institute, Mass Eye and Ear, Boston, MA, USA; 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.
PMID: 31784416 DOI: 10.1016/j.ymthe.2019.11.005
Abstract

Adeno-associated virus (AAV) is a highly promising gene transfer vector, yet major cellular requirements for AAV entry are poorly understood. Using a genome-wide CRISPR screen for entry of evolutionarily divergent serotype AAVrh32.33, we identified GPR108, a member of the G protein-coupled receptor superfamily, as an AAV entry factor. Of greater than 20 divergent AAVs across all AAV clades tested in human cell lines, only AAV5 transduction was unaffected in the GPR108 knockout (KO). GPR108 dependency was further shown in murine and primary cells in vitro. These findings are further validated in vivo, as the Gpr108 KO mouse demonstrates 10- to 100-fold reduced expression for AAV8 and rh32.33 but not AAV5. Mechanistically, both GPR108 N- and C-terminal domains are required for transduction, and on the capsid, a VP1 unique domain that is not conserved on AAV5 can be transferred to confer GPR108 independence onto AAV2 chimeras. In vitro binding and fractionation studies indicate reduced nuclear import and cytosolic accumulation in the absence of GPR108. We thus have identified the second of two AAV entry factors that is conserved between mice and humans relevant both in vitro and in vivo, further providing a mechanistic understanding to the tropism of AAV gene therapy vectors.

Keywords

AAV; CRISPR screen; GPR108; adeno-associated virus; endosomal escape; entry; in vivo; receptor.

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