Researchers experimenting with a protein from hepatitis B virus have developed a new technique for delivering therapeutic genes to the liver while minimizing the accidental introduction of genes to other tissues.
The ideal delivery system for a gene therapy would target only those organs or tissues that need genetic repairs. Live viruses that are altered to carry human genes meet that criterion, but they can trigger dangerous immune responses and cause other problems. Other delivery vectors tend to usher genes to tissues other than the intended ones, a flaw that can lead to side effects.
Shun'ichi Kuroda of Osaka University in Japan and his colleagues suggest a hybrid vehicle: hollow globules of fat covered with a protein isolated from hepatitis B virus. These so-called L particles selectively target liver cells, just as hepatitis B virus does, but are less likely than an intact virus to get out of hand, the researchers say.