The central nervous system and the immune system work closely together to maintain host homeostasis. In fact, it has been recognised for many years that disruptions in this interplay, such as in a brain injury, can lead to an impairment of host immunity and renders the host with increased risks to infections. Therefore, using a mouse model, the project aims to delineate the mechanisms underlying the immune suppression after stroke. The expected outcome of these experiments is to advance our understanding of basic biology and to identify mechanisms that contribute to immune regulation and susceptibility to infection following a brain injury.