A team of Japanese and Belgian scientists have managed to temporarily cure hemophiliac mice with gene therapy. Lead study author Tadanori Yamada of Osaka University, and colleagues used a small, hollow fragment of the hepatits B virus to deliver the gene therapy to the animals. The problem with using engineered viruses is that the genes are sometimes delivered to tissues other than those the scientists want to target, however the hepatitis B-based gene therapy only appears to target the liver. Tests showed that the virus particles successfully delivered blood clotting genes to the liver, and that the body then went on to produce measurable amounts of blood clotting proteins for roughly 40 days. The researchers conclude that their method appears to provide a “a safe vehicle for delivering both genes and drugs.” Other scientists commenting on the technique say that it has its limitations. Dr Mark Kay, director of Stanford University’s Human Gene Therapy Program, said the findings were “encouraging,” but warned that the therapy only provides a temporary cure and that repeated injections of the therapy will cause the body to build up a resistance to it. Meanwhile, Inder Verma of the Salk Institute of Biological Studies, commented that a major problem with using the hepatitis B virus is that many people are vaccinated against it and thus the body will kill the therapy as it would the virus.
SOURCE/REFERENCE: Reported by www.ap.org on the 30th June 2003.
