A novel class of self-complementary AAV vectors with multiple advantages based on cceAAV lacking mutant ITR

Area of Science:

• Molecular Biology
• Gene Therapy
• Virology

Background:

• Self-complementary AAV (scAAV) vectors facilitate rapid transgene expression.
• Inefficient resolution of mutant inverted terminal repeats (mITR) in scAAV vectors leads to noncanonical genomes, reducing expression and potentially impacting safety.

Purpose of the Study:

• To develop a novel class of scAAV vectors, termed covalently closed-end AAV (cceAAV) vectors.
• To overcome the limitations associated with mITR resolution in traditional scAAV vector production.

Main Methods:

• Developed cceAAV vectors utilizing a protelomerase (TelN) recognition sequence to covalently join DNA strands, eliminating the need for mITR resolution.
• Employed a single ITR for vector generation.
• Utilized standard triple-plasmid transfection and AAV vector purification protocols.

Main Results:

• cceAAV vectors achieved yields comparable to traditional scAAV vectors.
• Demonstrated significantly enhanced transgene expression compared to scAAV vectors.
• Showed enhanced long-term FIX expression in hemophilia B mouse models using cceAAV-FIX.

Conclusions:

• cceAAV vectors offer an improved alternative to scAAV vectors for gene therapy applications.
• The novel design enhances transgene expression and holds promise for developing advanced gene therapy drugs.
• This technology may lead to safer and more effective gene transfer strategies.