In 2007, given the limitations of genome editing to that point, it was clear that a more robust and efficient technology was needed to be able to routinely generate genetically defined human cell lines. To achieve this goal, Horizon applied a seminal discovery by Professor David Russell that certain forms of Adeno-Associated Virus (AAV) were more than 1,000 times more efficient at gene-targeting in human somatic cell-types than plasmid-based methods.
What is rAAV?
Definition: Recombinant Adeno-Associated Virus or rAAV uses an exchange of nucleotide sequences to enable insertion, deletion or replacement of DNA sequences in cells. Unlike other gene editing methods, this is achieved without causing a double strand DNA break, instead stimulating endogenous homologous recombination. Due to its non-pathogenic nature, it is also suitable for gene therapy in live patients.
In this approach, homologous recombination (HR) allows the precise and specific ability to edit-on-demand the genome of any mammalian cell down to single base-pair resolution and without sequence error. rAAV is an excellent tool for the generation of knockins or any modifications that should involve a single allele.
The use of rAAV vectors in gene-targeting has since been further refined for an additional tenfold increase in efficiency. Efforts are also underway to blend rAAV with CRISPR to develop a hybrid platform that combines the ease and efficiency of CRISPR gene editing with the precision and capacity for knockins of rAAV.
Find out how Horizon is systematically optimizing its gene editing workflows, and combining CRISPR and rAAV for maximum efficiency