Pooled Screens Identify GPR108 and TM9SF2 as Host Cell Factors Critical for AAV Transduction

Area of Science:

• Molecular Biology
• Virology
• Gene Therapy

Background:

• Adeno-associated virus (AAV) is a crucial vector in gene therapy.
• Cellular entry and nuclear trafficking mechanisms of AAV remain incompletely understood.

Purpose of the Study:

• To identify host factors that modulate adeno-associated virus type 2 (AAV2) transduction.
• To elucidate the cellular pathways involved in AAV entry and trafficking.

Main Methods:

• Conducted two pooled, genome-wide screens using AAV2 encoding EGFP in U-2 OS cells.
• Utilized genome-wide libraries targeting all human genes for screening.
• Validated screen hits using flow cytometry and imaging studies.

Main Results:

• Identified KIAA0319L (AAVR), GPR108, and TM9SF2 as modulators of AAV2 transduction.
• Confirmed GPR108 and TM9SF2 roles in mediating transduction across eight AAV serotypes.
• GPR108 demonstrated serotype selectivity, not being essential for AAV5 transduction.
• GPR108 was localized to the Golgi, suggesting a role in AAV trafficking or escape.

Conclusions:

• Expanded understanding of AAV transduction mechanisms across different cell types and serotypes.
• Highlighted GPR108 as a critical, serotype-selective factor in AAV cellular entry and trafficking.
• Provided insights into potential AAV-host interactions within the Golgi apparatus.