Towards Cell-Based Therapy of Alopecia Areata: Autologous Human Vδ2+ Foxp3+ γδTreg Cells Restore Hair-Follicle Immune Privilege and Promote Hair Regrowth in Human Alopecia Areata Models Ex Vivo and In Vivo

The study investigates the use of autologous human Vδ2+ Foxp3+ γδTreg cells as a cell-based therapy for alopecia areata (AA). These cells were expanded and activated in vitro and then injected into human scalp skin xenografts on mice. The γδTregs successfully reduced lymphocytic infiltration, restored hair follicle immune privilege, and promoted hair regrowth in AA lesions. In ex vivo models, they suppressed pathogenic T-cell activity and counteracted AA hallmarks through IL-10 and TGF-β1 secretion, contact-dependent inhibition, and adenosine generation. The findings indicate that γδTregs could be a promising therapeutic approach for AA and other autoimmune diseases involving immune privilege collapse.