Using a barcoded AAV capsid library to select for clinically relevant gene therapy vectors.

Area of Science:

• Gene therapy
• Viral vector development
• Cell biology

Background:

• Recombinant adeno-associated viral (rAAV) vectors are used for gene transfer but have limitations in transducing certain tissues.
• Recent advances in reprogramming cells offer new therapeutic avenues for diseases like diabetes.

Purpose of the Study:

• To develop novel AAV vectors with enhanced transduction efficiency for primary human islets and hepatocytes.
• To identify a versatile vector suitable for both preclinical research and clinical applications in metabolic diseases.

Main Methods:

• Construction and screening of complex barcoded replication-competent capsid-shuffled AAV libraries.
• Selection of high-transducing variants using primary human islets.
• Evaluation of transduction efficiency in human islet cells, human embryonic stem cell-derived β cells, and hepatocytes in a humanized chimeric mouse model.

Main Results:

• Generation of a chimeric AAV capsid, designated AAV-KP1.
• AAV-KP1 demonstrated up to 10-fold higher transduction efficiency in primary human islets and human embryonic stem cell-derived β cells compared to existing best-in-class AAV vectors.
• High-level transduction of both mouse and human hepatocytes was achieved using AAV-KP1 in a humanized chimeric mouse model.

Conclusions:

• AAV-KP1 is a highly efficient chimeric AAV vector for transducing human islet cells and hepatocytes.
• This versatile vector holds significant potential for advancing gene therapy strategies for diabetes and liver-based diseases.
• AAV-KP1 facilitates preclinical testing and may be applicable in future human clinical trials.