The key to developing a new drug to fight HIV may lie in the blood of a patient whose immune system can control the infection, a new study says. Scientists discovered proteins in the patient’s blood that blocked the virus from infecting immune cells. Researchers hope to harness these proteins not only to treat the virus, but to help develop a vaccine.
HIV is such a dangerous virus because it attacks the very cells that would normally fight it off, called T cells. These cells protect the body against infections, and when an HIV patient’s T cells drop to dangerously low levels, the patient is said to have progressed to AIDS; AIDS patients typically die of secondary infections the body is too weak to fight off.
Antibodies that successfully neutralize HIV are rare
That’s why this patient, called Z258, is so important: his body has a natural immunity to the virus. His immunity is a little different than the famous Berlin Patient, who received a bone marrow transplant from someone who has T cells HIV can’t bind to — and thus can’t infect. Instead, patient Z258’s blood contained immune proteins called antibodies that block the virus from infecting cells, and they can neutralize a whopping 98 percent of the de-clawed HIV virus strains the scientists generated in the lab. These antibodies could even block strains that other, similar antibodies were powerless against. Even though HIV was detectable in his blood and he wasn’t being treated at the time, this patient had normal T cell levels after more than two decades of infection. The researchers named the antibody N6 in their findings published this week in the journal Immunity.
“It is an important step, it’s very interesting scientifically,” says Lars Hangartner, an immunologist at the Scripps Research Institute. While experiments with antibody therapies haven’t completely cleared primates’ bodies of HIV, understanding how the body generates effective neutralizing antibodies could help with designing vaccines. And antibodies could be useful preventative treatments if someone suspects they’ve been exposed to HIV, he says.