An ancient virus reconstructed by researchers could make gene therapy more efficient.

Credit: Livia Carvalho

Viruses are used in such therapies to deliver functioning genes to diseased cells in the body, but better viruses are needed to transfer genes more efficiently. Luk Vandenberghe of the Massachusetts Eye and Ear Infirmary in Boston and his colleagues analysed the amino-acid sequences of the proteins that coat 75 adeno-associated viruses (AAV), 5 of which are being tested in human gene-therapy trials. They predicted how the structure of these proteins might have evolved, and came up with protein sequences for 9 AAVs that might have been ancestors of the current viruses. They synthesized the ancient AAVs and found that one, Anc80, could efficiently transfer genes to muscles and the retina in mice (pictured), and to the liver in both mice and monkeys.

Anc80 did not trigger any negative side effects in these animals that would prevent it from delivering genes to cells.

Cell Rep. (2015)