The Cold Case Files of rAAV Capsid Influence on Transduction: New Leads

Area of Science:

• Gene Therapy
• Molecular Biology
• Virology

Background:

• Adeno-associated virus (AAV) is a key vector in gene therapy, with capsid engineering focused on cell targeting and reduced immunogenicity.
• Stable transgene expression is crucial for therapeutic efficacy, but current methods rely on transgene cassette elements.
• Emerging evidence suggests AAV capsid residues, separate from those involved in receptor binding, can influence transgene expression.

Purpose of the Study:

• To review and consolidate evidence for a novel role of AAV capsid residues in mediating transgene expression.
• To elucidate the mechanisms by which the AAV capsid influences transgene expression.
• To highlight the implications of these findings for future AAV capsid engineering strategies.

Main Methods:

• Literature review and data synthesis.
• Analysis of existing studies on AAV capsid function and gene expression.
• Focus on capsid interactions with transgenes, cellular proteins, and epigenetic modifications.

Main Results:

• Accumulating evidence supports a role for specific AAV capsid residues in regulating transgene expression.
• These regulatory capsid elements are distinct from those mediating cellular receptor binding.
• Potential mechanisms involve interactions with the transgene, cellular proteins, and epigenetic modulation.

Conclusions:

• AAV capsid residues, beyond their role in cell entry, can significantly influence transgene expression levels and stability.
• Understanding these capsid-mediated regulatory mechanisms is essential for optimizing AAV gene therapy vectors.
• This review proposes a paradigm shift in AAV capsid engineering, incorporating transgene expression control.