Researchers from Linköping University in Sweden announced on Mar. 23 that an existing medication may help restore immune cell function in people living with HIV, according to a study published in the journal PLOS Pathogens.
The findings are significant because, while antiviral treatments can control the amount of HIV virus in the blood and slow AIDS progression, many patients still experience impaired immune systems and premature ageing due to chronic activation of their immune response. The study aimed to understand how HIV causes ongoing dysregulation of immunity even under effective treatment.
Normally, when a person is infected by a virus, type I interferon protein activates as an early defense mechanism and then subsides once the infection is controlled. However, researchers found that HIV exploits this signaling pathway by maintaining high levels of type I interferon activation even when viral levels are suppressed by medication. "In the case of an HIV infection, type I interferon provides protection in the first stage when the body gets infected. But if the interferon is chronically activated, an overactivation of the immune system will instead facilitate the spread of HIV in the body," said Cecilia Svanberg, postdoctoral fellow at Linköping University and lead author of the study.
Chronic immune activation eventually exhausts important cells such as dendritic cells and T cells. The research team’s experiments showed that this chronic activation occurs specifically during interactions between these two cell types. This discovery suggests a potential way to restore normal function to exhausted immune cells.
The medication tested was anifrolumab, which blocks type I interferon and is already used for treating systemic lupus erythematosus (SLE). Animal studies have shown that blocking this pathway can reduce viral loads and improve health outcomes for animals with infections similar to HIV. "Using this interferon blocker together with existing antiviral treatment could possibly improve the health of people living with HIV. We think it would be worth investigating further," said Marie Larsson, professor of virology at Linköping University who led the study.
The research was funded by organizations including the Swedish Research Council and Region Östergötland.
