AAV library screening identifies novel vector for efficient transduction of human aorta

Area of Science:

• Biotechnology
• Gene Therapy
• Vascular Biology

Background:

• Targeted gene delivery to vascular smooth muscle cells (VSMCs) is crucial for treating various vascular and aortic diseases.
• Existing adeno-associated virus (AAV) vectors have limitations in efficiently targeting VSMCs.

Purpose of the Study:

• To develop and identify a novel AAV capsid motif with enhanced targeting and gene delivery efficiency to VSMCs.
• To compare the efficacy of the novel motif against existing AAV vectors and peptides.

Main Methods:

• Engineered AAV capsids were selected from a random library using a barcoding system for parallel screening.
• Three rounds of selection were performed on primary murine VSMCs (mVSMCs).
• Transduction and transgene expression efficiency were analyzed using genomic DNA (gDNA) and transcribed cDNA reads.

Main Results:

• A novel targeting motif (RFTEKPA) was identified, significantly improving transduction and gene expression in mVSMCs by 70% over AAV9-wild type (WT) and a previously identified peptide (SLRSPPS).
• The novel motif demonstrated improved expression in human aortic smooth muscle cells (HAoSMCs) and human aortic tissue ex vivo, up to threefold compared to SLRSPPS and approximately 70-fold compared to AAV9-WT.
• High cross-species transduction efficiency was observed.

Conclusions:

• The novel RFTEKPA AAV capsid motif exhibits superior targeting and gene delivery efficiency to VSMCs compared to AAV9-WT and SLRSPPS.
• This motif holds significant potential for clinical applications in treating vascular diseases.
• The developed screening method effectively distinguishes between transduction and transgene expression capabilities of AAV capsids.