Lab notes: Antibody neighbours can protect the immune system from HIV attack

Scientists at The Scripps Research Institute in the United States have found a way to potentially cure HIV infection. The scientists are testing a new therapy by tethering HIV-fighting antibodies to immune cells and created cell populations resistant to the virus. Under laboratory conditions, these resistant cells quickly replace diseased cells offering long-term protection to a person infected with the HIV virus.

The therapy described in a study published in the journal Proceedings of the National Academy of Sciences offers a significant advantage over others in which antibodies float freely in the bloodstream at a lower concentrations. Here, antibodies latch on to the white blood cell surface, blocking the HIV virus reaching receptor sites to cause infection. The researchers call this the “neighbour effect”, with one attached neighbour antibody being far more effective in repelling the virus than many free antibodies in the vicinity.

The scientists first tested their method on the rhinovirus, which is responsible for many cases of the common cold. They introduced a new gene to cultured human cells that instructed cells to synthesise antibodies that bind with the cell receptor that the rhinovirus binds to. The researchers then added rhinovirus to these cell populations, which were a mix of both engineered and therefore ”vaccinated” cells and unengineered cells. In two days they found that populations of only the unengineered cells that did not have antibody protection died off. The populations of mixed cells that had initially started to die out but quickly bounced back.

The researchers then tested the same method against HIV by making antibodies that bind to the CD4 receptor sites of white blood cells. After introducing cells to the virus, the researchers got an HIV-resistant cell population.

The research team will now evaluate this new therapy before conducting trials with HIV-infected patients. The team is evaluating the possibility of using gene therapy for AIDS using blood stem cell transplantation to test this new antibody therapy.