New study shows how HIV evades the immune system

It is heartening that scientists have just discovered a new mechanism by which HIV evades the immune system, and which shows precisely how the virus avoids elimination. The new research shows that HIV targets and disables a pathway involving a number of biological molecules that are key in blocking viral activity and clearing infection.A team of scientists from Trinity College Dublin has identified the mechanism that enables HIV to evade the immune system, paving the way for a new curative treatment, according to a study published in EBioMedicine, which is a collaborative online journal from Cell Press and the Lancet.HIV remains a major global health problem, with over 40mn 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 will provide a shot in the arm 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.”According to the World Health Organisation (WHO), 76% [60–88%] of all pregnant women living with HIV globally received medicines that prevent transmission to their babies in 2016. Almost 21mn people were receiving antiretroviral treatment by mid-2017. Further, 53% [39–65%] of people living with HIV were receiving antiretroviral treatment in 2016. The WHO African Region is the most affected region, with 25.6mn people living with HIV in 2016. The African region also accounts for almost two thirds of the global total of new HIV infections.