Regulatory T lymphocytes in traumatic brain injury

Traumatic brain injury (TBI) presents a significant global health challenge with no effective therapies developed to date. Regulatory T lymphocytes (Tregs) have recently emerged as a potential therapy due to their critical roles in maintaining immune homeostasis, reducing inflammation, and promoting brain repair. Following TBI, fluctuations in Treg populations and shifts in their functionality have been noted. However, the precise impact of Tregs on the pathophysiology of TBI remains unclear. In this review, we discuss recent advances in understanding the intricate roles of Tregs in TBI and other brain diseases. Increased knowledge about Tregs may facilitate their future application as an immunotherapy target for TBI treatment. •The number and phenotype of circulating and brain infiltrating Tregs change after TBI.•Tregs exert neuroprotective, reparative, and analgesic effects after TBI.•Treg expansion and Treg/stem cell combination therapy are potential immunotherapies for TBI.