Our immune system is our chief defence against infection, but it is a double-edged sword. Inappropriate or over-exuberant immune responses can be harmful or even fatal. The optimal response is one that is strong enough to clear the pathogen but not so strong that it also kills the host, and our lab is working to understand how that balance is achieved. We study a family of signalling molecules known as cytokines, soluble messengers used by cells of the immune system to communicate with one another. Cytokines can influence the size, speed and quality of an immune response. We want to know how cells control their response to cytokines and how cytokine instructions change as an immune response progresses. We use viral, bacterial and parasitic infection models to analyse cytokine responses in vivo, and our goal is to be able to manipulate cytokine signalling in order to improve the outcome in infection or other immune-related disease.