GPR108 Is a Highly Conserved AAV Entry Factor.

Area of Science:

• Molecular Biology
• Virology
• Gene Therapy

Background:

• Adeno-associated virus (AAV) is a key gene therapy vector.
• Cellular entry mechanisms for AAV remain largely unknown.
• Understanding AAV entry factors is critical for optimizing gene delivery.

Purpose of the Study:

• To identify cellular factors required for adeno-associated virus (AAV) entry.
• To elucidate the role of G protein-coupled receptor 108 (GPR108) in AAV transduction.
• To understand the mechanistic basis of AAV vector tropism.

Main Methods:

• Genome-wide CRISPR screening to identify AAV entry factors.
• Utilized AAVrh32.33 serotype for screening in human cell lines.
• Validated findings using GPR108 knockout (KO) in human, murine, and primary cells, as well as in vivo mouse models.

Main Results:

• GPR108 was identified as a novel AAV entry factor.
• GPR108 is essential for transduction by most tested AAV serotypes, except AAV5.
• Gpr108 KO mice showed significantly reduced AAV expression in vivo.
• Mechanistic studies revealed the requirement of GPR108 domains and identified capsid interactions affecting nuclear import.

Conclusions:

• GPR108 is a conserved AAV entry factor essential for most AAV serotypes.
• This discovery provides mechanistic insights into AAV tropism and nuclear import.
• GPR108 represents a potential target for enhancing AAV gene therapy efficacy.