Immunomodulators Could Potentially Treat HIV

Targeting CD4+ T lymphocytes could help antiretroviral therapy eliminate all HIV.

In a recent study, researchers discovered that certain cells provide a “safe house” for HIV during antiretroviral therapy (ART), allowing it to live and proliferate.

“We have found cell markers to target HIV reservoirs,” said principle investigator Nicolas Chomont, PhD. “This discovery has opened new treatment perspectives to eliminate these reservoirs and perhaps one-day cure people infected with the virus."

During ART, HIV survives in pools of cells called reservoirs, according to the study, published by PLOS Pathogens.

"Antiretroviral drugs work well. Generally, viral loads fall to undetectable levels in hospital blood tests," Dr Chomont said. “The problem is that if the person stops ART, the virus returns quickly, because it was hidden in these pools. The goal of my laboratory is to identify the cells in which the virus hides and eliminate them. If we succeed, then infected people may eventually be able to safely stop ART, which is not without its side effects”

HIV is typically housed in CD4+ T lymphocytes, which defend the body against infections; however, the reservoir pool is difficult to find since there are a million cells but only 1 cell pool. The researchers were able to identify 3 cell markers that are characteristic of the reservoir pools.

The proteins PD-1, LAG-3, TIGIT are expressed at the surface of the cells that house the virus, according to the study.

"Using the house analogy, PD-1, LAG-3, and TIGIT are the chimney, door, and fence, for example," Dr Chomont said. “The goal is to destroy all the houses that have these characteristics, in order to eliminate the virus.”

The researchers plan to continue testing antibodies that bind to these markers. Since some immunomodulators are already approved for use, these findings could be implemented fairly quickly.

“This discovery is important because, until now, no combination of markers has had the potential for therapeutic treatment against HIV pools,” concluded researcher Rémi Fromentin, PharmD, PhD. “The advantage is that anticancer drugs that specifically target these markers already exist. We believe we could use the same drugs to destroy HIV reservoirs.”