Numerous retroviral particles (pseudocoloured) endogenously produced by lymphoma cells in an immune-deficient mouse.

George Kassiotis : Retroviral Immunology Laboratory

We are investigating why some types of viruses set up long-term infections inside cells and how they affect gene activity, evolution and disease.

There are many types of viruses that infect humans and they work in different ways. Some viruses just ‘hit and run’ - such as the viruses that cause flu or the common cold - infecting cells and causing disease but disappearing afterwards.

Others, including HIV, herpes and hepatitis, set up long-term, lingering infections that can last a lifetime. We want to find out how these long-term (chronic) viral infections are established and discover why the immune system doesn’t get rid of them.

As well as studying external viruses that infect us, we are also investigating a group of ancient viruses that have been hiding in the human genome for many thousands of years, known as endogenous retroviruses.

We want to find out how these internal viruses have evolved to become useful, switching genes on or off as part of normal life, and how they might be involved in disease. Intriguingly, some of them even seem to help the immune system respond to viral infection.

Our work is shedding light on the ways in which humans and viruses co-exist and have evolved together, revealing more about their role in health and disease and pointing towards new ideas for anti-viral treatments.