Human epidermal resident memory T cells: beyond the dermal perspective

This review highlights the significant role of epidermal resident memory T (T RM) cells in immune surveillance, challenging the traditional focus on the dermis. The epidermis, previously seen mainly as a physical barrier, is now recognized as a specialized immunological compartment with abundant T RM cells, including CD8+ CD69+ CD103+ populations and regulatory T RM cells. These cells interact with Langerhans cells and keratinocytes, forming an integrated immune ecosystem that maintains epidermal immune homeostasis. The review also links epidermal T RM cells to diseases like HIV, fixed drug eruption, vitiligo, and alopecia areata, suggesting that understanding this network could offer new insights into disease pathogenesis and treatment.