Scientists uncover how HIV evades elimination by the immune system

The new research shows that HIV targets and disables a pathway involving a number of biological molecules that are fundamental in blocking viral activity and clearing infection, illustrating precisely how the virus avoids elimination.

HIV remains a major global health problem, with over 40 million people infected worldwide. Whilst people living with the virus have been treated with anti-retroviral therapy for over 30 years, this favoured therapeutic option merely prevents the progression of the disease to AIDS – it doesn’t provide a cure.
The discovery of this mechanism represents a major step forward in the quest to develop an effective treatment for the virus and opens the door to a new era of research in this area.

During any viral infection our immune system produces a powerful molecule (interferon), which ‘interferes’ with the infection and the replication of viruses. Interferon activates an assembly line of molecules in our cells – via the interferon signalling pathway – which causes the body to make antivirals that help to clear the infection.

However, when patients are being treated with anti-retroviral therapy, HIV is not fully cleared by our immune system. Therefore, the team of scientists from Trinity College Dublin investigated whether the virus was somehow blocking the interferon signalling pathway and thus avoiding the immune response that is designed to cure viral infection. The findings confirmed their suspicions.

Commenting on the mechanism that HIV uses to prevent eradication, Nigel Stevenson, Assistant Professor in Immunology at Trinity, said: “We discovered that HIV promotes the destruction of the anti-viral interferon signalling pathway. Essentially, HIV uses the machinery in our own cells to do this, and the virus is thus able to reduce the production of many important anti-viral molecules. Without these anti-viral molecules, our immune system can’t clear viral infections.”

“Our new revelation sheds new light on how HIV avoids elimination, which, in turn, may explain why HIV is still not a curable disease. We feel this discovery could mark a paradigm shift in our understanding of how this virus evades our immune response. It should open the door to a new era of HIV research aiming to cure and eradicate this deadly virus.”

The study was published in EBioMedicine.