Understanding the T cell repertoire in health and disease. Immune recognition of viruses usually involves a large number of different 'killer T cells' that kill cells infected by virus. However, during prolonged infection or in the elderly the number of different killer T cells that recognise the virus is greatly reduced. This reduction in the diversity of the immune response allows the virus to avoid immune recognition, and leads to more severe infection. We aim to understand how diversity is ....Understanding the T cell repertoire in health and disease. Immune recognition of viruses usually involves a large number of different 'killer T cells' that kill cells infected by virus. However, during prolonged infection or in the elderly the number of different killer T cells that recognise the virus is greatly reduced. This reduction in the diversity of the immune response allows the virus to avoid immune recognition, and leads to more severe infection. We aim to understand how diversity is generated in the immune response, and how it becomes narrowed with age or prolonged infection. This information can be used to design vaccines for persistent infections such as HIV, and to improve immune control of infection in the elderly.Read moreRead less