Researchers Announce a Breakthrough on HIV/AIDS Treatment

A technique that alters T cells has been shown to reduce the amount of virus in infected people.

Sangamo's approach is based on the observation that some people have a naturally occurring mutation in the CCR5 gene that protects them against HIV. Ordinarily, humans have two copies of every gene. It turns out that individuals with a mutation in both copies of the CCR5 gene cannot be infected by the most common HIV strains. In people with the so-called Delta-32 mutation in just one copy of the gene, infection rarely progresses to AIDS. In the U.S., about 1 percent of the population is thought to carry the helpful mutation, which some researchers believe arose as protection against the Black Death.

Previous evidence existed showing that CCR5-negative cells could help AIDS patients. In 2007, an American man with AIDS and lymphoma received, as treatment for the cancer, a bone-marrow transplant from a person with the CCR5 mutation. The marrow recipient has been free of both AIDS and cancer since then. Sangamo's method treats a patient's own cells, with less risk than a marrow transplant.