GAMMA-DELTA-T-CELL RECEPTOR-POSITIVE CELLS OF HUMAN SKIN .2. APPEARANCE IN DELAYED-TYPE HYPERSENSITIVITY REACTION

In order to investigate the distribution and involvement of human gammadelta T-cell receptor-positive (TCR+) cells in delayed-type hypersensitivity reactions of the skin, we examined the occurrence and kinetics of gammadelta TCR+ cells during skin reactions of allergic contact dermatitis. In normal human skin sections, gammadelta TCR+ cells were scarce. In allergic contact dermatitis from DNCB, increased gammadelta TCR+ cells were observed both in the epidermis and in the dermis from 48 h after the challenge. Most of the gammadelta TCR+ cells were TCRdelta1+ deltaTCS1- BB3+ TigammaA+ (Vdelta1- Vdelta2+ Vy9+). The percentage of gammadelta TCR+ cells in the peripheral blood remained unchanged and a few gammadelta TCR+ cells in the skin lesions proliferated in situ. It is suggested that the gammadelta TCR+ cells in skin lesions of allergic contact dermatitis may not be involved in initiation of delayed-type hypersensitivity but may have some other roles responding to factors induced in the reaction.