A new study suggests that some protease inhibitors (PIs) might be doing double duty—stopping viral reproduction and calming down a hyper-active immune system.

A team led by Luigi Racioppi, PhD, in Italy, looked at the maturation process of a type of immune cell known as dendritic cells (DCs) in the presence of a handful of older PIs. They found that both Norvir (ritonavir) and Invirase (saquinavir) caused newly matured DCs to behave oddly. The cells barely responded to the presence of a bacterium that circulates widely in people with HIV.

In most cases a robust immune response is the goal, but experts now think that chronic inflammation—both against HIV and bacteria that leak out of HIV-damaged cells in the gut—is at the root of a lot of bad stuff, namely cardiovascular disease and certain cancers. In this case, grown-up DCs that don't overreact to gut bacteria could be just what the doctor ordered.

Racioppi's team is set to look at newer PIs such as Prezista (darunavir) and Reyataz (atazanavir). Studying the anti-inflammatory properties of these drugs, he says, “would open [new avenues] for designing PIs with more powerful activity on the immune system.”