Novel human liver-tropic AAV variants define transferable domains that markedly enhance the human tropism of AAV7 and AAV8

Recent clinical successes have intensified interest in using adeno-associated virus (AAV) vectors for therapeutic gene delivery. The liver is a key clinical target, given its critical physiological functions and involvement in a wide range of genetic diseases. Here, we report the bioengineering of a set of next-generation AAV vectors, named AAV-SYDs (where SYD stands for Sydney, Australia), with increased human hepatotropism in a liver xenograft mouse model repopulated with primary human hepato-cytes. We followed a two-step process that staggered directed evolution and domain-swapping approaches. Using DNA-family shuffling, we first mapped key AAV capsid regions responsible for efficient human hepatocyte transduction in vivo. Focusing on these regions, we next applied domain-swapping strategies to identify and study key capsid residues that enhance primary human hepatocyte uptake and transgene expression. Our findings underscore the potential of AAV-SYDs as liver gene therapy vectors and provide insights into the mechanism responsible for their enhanced transduction profile.

Automated summary

Recent clinical successes have increased interest in using adeno-associated virus (AAV) vectors for therapeutic gene delivery. This study bioengineered a new generation of AAV vectors, called AAV-SYDs, with increased human hepatotropism. By employing directed evolution and domain-swapping strategies, the key capsid residues responsible for enhanced primary human hepatocyte uptake and transgene expression were identified and studied. These findings highlight the potential of AAV-SYDs as liver gene therapy vectors and provide insights into their enhanced transduction profile.