Potential HIV Treatment on the Horizon

Special patient population produces new broadly neutralizing antibodies to defeat HIV.

A trio of broadly neutralizing antibodies (bNAbs) was able to fully suppress HIV in infected mice during a recent study.

Most individuals with HIV develop AIDS if the virus is not managed with antiretroviral therapy (ART). However, there is a small group of HIV-positive individuals—–referred to as elite controllers––whose immune systems are capable of defeating the virus.

Elite controllers manufacture bNAbs that can take down multiple forms of HIV. Using antibodies from 1 of these elite controllers, a study published in Science Translational Medicine revealed that a combination of 3 antibodies completely suppressed the virus in HIV-infected mice.

“Some people with HIV produce these antibodies, but most of the time the virus eventually escapes them through mutations in the antibody’s corresponding epitope,” said first author Natalia Freund.

The epitope is the part of the virus that an antibody attaches itself to allowing the virus to mutate, according to the investigators.

“Think of the relationship between the antibodies and the virus as an arms race that goes on and on,” Freund said. “By mutating, some of the virus may escape the antibodies and continue growing. Years later, the body may produce new broadly neutralizing antibodies against the escaped virus, which in turn may mutate and escape yet again.

“What we’ve shown in this study is that after several rounds of escape from these particular antibodies, the virus seems to run out of options. In this particular case, HIV eventually loses this arms race.”

The immune system of an elite controller can defeat the virus by producing new bNAbs, as well as cytotoxic T cells.

Included in the study was a patient with HIV who had been working with the team for 10 years. At least 3 decades ago, the patient was infected with HIV, and since then developed 3 different types of antibodies that bind to 3 different sites on the virus, according to the authors.

In the study, mice infected with HIV—–whose immune systems had been modified to more closely resemble those of humans––were administered BG18, NC37, and BG1. Three weeks after the bNAbs were administered, the results of the study showed that the combination rendered the virus undetectable in two-thirds of the mice.

“This study validates the approach of using 3 different antibodies to control HIV infection, pointing the way toward a potential new treatment for people infected with HIV,” Freund concluded.