摘要
In addition to maintaining immune tolerance, FOXP3 + regulatory T (T reg ) cells perform specialized functions in tissue homeostasis and remodelling 1,2 . However, the characteristics and functions of brain T reg cells are not well understood because there is a low number of T reg cells in the brain under normal conditions. Here we show that there is massive accumulation of T reg cells in the mouse brain after ischaemic stroke, and this potentiates neurological recovery during the chronic phase of ischaemic brain injury. Although brain T reg cells are similar to T reg cells in other tissues such as visceral adipose tissue and muscle 3–5 , they are apparently distinct and express unique genes related to the nervous system including Htr7, which encodes the serotonin receptor 5-HT 7 . The amplification of brain T reg cells is dependent on interleukin (IL)-2, IL-33, serotonin and T cell receptor recognition, and infiltration into the brain is driven by the chemokines CCL1 and CCL20. Brain T reg cells suppress neurotoxic astrogliosis by producing amphiregulin, a low-affinity epidermal growth factor receptor (EGFR) ligand. Stroke is a leading cause of neurological disability, and there are currently few effective recovery methods other than rehabilitation during the chronic phase. Our findings suggest that T reg cells and their products may provide therapeutic opportunities for neuronal protection against stroke and neuroinflammatory diseases.