Grant: Project Grant

In our global society, many of us travel to and from work, fly between cities, or even set up residence somewhere new. Along the way, we might bump into others, exchange information, and learn new things that inform our behaviour. Hence, what we learn during our travels can have a dramatic impact on our lives. T lymphocytes have a similarly cosmopolitan lifestyle within the body. The job of T cells in the immune system - to detect and stop the replication of a pathogen or cancer cell as quickly as possible - makes it essential for them to commute continuously between the blood and secondary lymphoid organs. Within lymphoid organs, T cells make critical interactions with other cells that dictate their function and fate. During infections, such interactions can license them to enter tissues and even set up residence there, protecting from reinfection. To understand the implications of the jet-setting behaviour of T cells on their function, we use advanced microscopy to track their movements within tissues in real time. This approach enables us to investigate a number of important questions. How do the interactions T cells make with other cells keep them alive? Why do pathogens or gene defects that prevent migration lead paradoxically both to severe immune deficiencies and to immune-mediated disease? In the long-term, answers to these questions will contribute to the design of better therapies for immunological diseases, such as allergy and autoimmunity, and allow us to harness the function of T cells to improve our ability to treat or prevent infections, from Ebola virus to HIV and beyond.