Resident T Cell Activation Leads to Human Hair Follicle Immune Privilege Loss Ex Vivo, Prevented by DHODH Inhibitor Farudodstat: Relevance for Alopecia Areata

This study explores the role of resident T cell activation in the loss of immune privilege in human hair follicles, which is linked to alopecia areata (AA). Using an ex vivo model with hair follicles from 7 healthy donors, researchers found that T cell activation led to immune privilege collapse, marked by increased MHC class I and II expression. The DHODH inhibitor farudodstat was shown to reduce T cell proliferation and MHC expression, partially preventing this collapse. These findings suggest that farudodstat could be a promising therapeutic candidate for AA by targeting T cell proliferation and preserving hair follicle immune privilege.