Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Immunology, Brain, Regulatory T cells, Tregs, Neuroimmunology, Multiple sclerosis, Stroke, Alzheimer's disease, WHITE-MATTER, B-CELLS, REPAIR, CNS, INFLAMMATION, POPULATION, RESPONSES, REQUIRES, MEMORY, Autoimmunity, Forkhead Transcription Factors, Homeostasis, Humans, Lymphocyte Activation, T-Lymphocytes, Regulatory, 1107 Immunology, 3204 Immunology

Abstract:

Regulatory T cells (Tregs) control inflammation and maintain immune homeostasis. The well-characterised circulatory population of CD4+Foxp3+ Tregs is effective at preventing autoimmunity and constraining the immune response, through direct and indirect restraint of conventional T cell activation. Recent advances in Treg cell biology have identified tissue-resident Tregs, with tissue-specific functions that contribute to the maintenance of tissue homeostasis and repair. A population of brain-resident Tregs, characterised as CD69+, has recently been identified in the healthy brain of mice and humans, with rapid population expansion observed under a number of neuroinflammatory conditions. During neuroinflammation, brain-resident Tregs have been proposed to control astrogliosis through the production of amphiregulin, polarize microglia into neuroprotective states, and restrain inflammatory responses by releasing IL-10. While protective effects for Tregs have been demonstrated in a number of neuroinflammatory pathologies, a clear demarcation between the role of circulatory and brain-resident Tregs has been difficult to achieve. Here we review the state-of-the-art for brain-resident Treg population, and describe their potential utilization as a therapeutic target across different neuroinflammatory conditions.