Approach could allow people infected with HIV to set aside their medication — without risking a resurgence of the virus.

Custom-designed immune cells can vanquish pockets of HIV hidden in the cells of people infected with the virus.

Antiretroviral therapies keep HIV in check, but virus-laden cells persist in the body — forcing people with the virus to take the drugs for life. Warner Greene at the Gladstone Institute of Virology and Immunology in San Francisco, California, and his colleagues sought a way to reduce and control the amount of this persistent HIV. Such a therapy could allow patients to safely stop taking medication.

The researchers opted to use CAR-T cells — immune cells that are engineered to home in on and destroy specific targets such as cancer cells. The team’s CAR-T cells kill HIV-infected cells and are guided to their targets by antibodies that can be easily changed. This confers flexibility on the killer cells, which the team named ‘convertible’ CAR-T cells.

In tests on blood cells taken from people infected with HIV, the convertible CAR-T cells cut the amount of latent virus by more than half in just two days.