Regulatory Gamma Delta T Cells Protect Human Scalp Hair Follicles From Alopecia Areata In Vivo

This study investigates the role of Foxp3+ γδ regulatory T cells (γδTregs) in protecting human scalp hair follicles from alopecia areata (AA). The researchers found an increased frequency of TCRVδ1/Foxp3 cells in the lesional skin of AA patients. They generated autologous human γδTregs and tested their effects in humanized AA mice and organ-cultured human scalp hair follicles. In vivo, γδTreg injections prevented AA induction and promoted hair regrowth in established lesions, restoring hair follicle immune privilege. Ex vivo, γδTregs reduced expression of immune privilege collapse markers and increased proliferation of hair matrix keratinocytes. The study suggests γδTregs as potential cell-based therapeutics for AA management.