Researchers at Philadelphia’s Jefferson Medical College have found that blocking small pieces of genetic material called microRNA (miRNA) could help antiretroviral drugs reach HIV that hides out in CD4 cells.

Current antiretroviral drugs only work against HIV that is reproducing inside active CD4 cells. While drug regimens can reduce virus in the blood below detectable levels, immature copies of HIV remain inside memory CD4 cells that have switched from an activated to a resting state. As soon a person stops taking the drugs, even after years of suppressing the virus, those immature copies of HIV can begin reproducing if the cells become active, ultimately reestablishing the infection in a short time. Gaining access to the dormant virus has been a major goal of scientists seeking a way to eradicate HIV from the body.

Now, Hui Zhang, MD, PhD, and colleagues have found that miRNA is what helps HIV quietly hide out inside the resting CD4 cells. When they artificially blocked miRNA in test tubes, HIV that had lain dormant inside resting cells began to reproduce. Dr. Zhang hopes this discovery will lead to treatments that safely block miRNA in people, saying that this “might become a kind of therapeutic approach to get the virus out of hiding, making it visible and a target.”