During the advent of gene therapy, fixing single-gene disorders seemed the most obvious application. But early vectors failed to transfect enough targeted cells long enough to have more than a transient effect. Recent animal studies using adeno-associated virus (AAV) may provide renewed hope for treating single-gene disorders. Two groups recently took advantage of AAV's ability to infect nondividing muscle cells--something that most other vectors cannot provide.1 And both used clever techniques to boost the gene therapy's efficacy.
A University of Pennsylvania Health System group used AAV along with histamine to treat hamsters with limb-girdle muscular dystrophy (MD).2 And a Salk Institute group in La Jolla, Calif., added to the evidence that AAV may be able to help treat hemophilia.3
Researchers had previously been stymied in getting the virus to infect large amounts of muscle. Intravenous injections weren't effective because the viruses stayed in the bloodstream, comments Hansell H. Stedman, assistant ...