APPEARANCE OF GAMMA-DELTA T-CELL RECEPTOR-POSITIVE CELLS FOLLOWING ALPHA-BETA T-CELL RECEPTOR-POSITIVE CELLS IN THE LEPROMIN REACTION OF HUMAN SKIN

To elucidate the involvement of human gammadelta T cell receptor (TcR)+ cells in mycobacterial infection, we examined the kinetics of these cells in skin lesions of human lepromin reaction. The majority of CD3+ cells two days after induction of the lepromin reaction were alphabeta TcR+, while gammadelta TcR+ cells accounted for only 4.4 +/- 1.4% of the CD3+ cells. On day 21, the incidence of gammadelta TcR+ cells was greater (16.0 +/- 2.1%), although alphabeta TcR+ cells remained the predominant population. These kinetics of alphabeta TcR+ cells and gammadelta TcR+ cells contradict the 'early response, self-surveillance' hypothesis for gammadelta TcR+ cells in mice. Most of the gammadelta TcR+ cells in this study of the lepromin reaction were Vdelta1- Vdelta2+ Vgamma9+, and some of them proliferated in the skin lesions, suggesting that gammadelta TcR+ cells in the lesions may respond to mycobacterial antigens and may play an active part in the lepromin reaction. However, these gammadelta TcR+ cells were not correlated with granuloma formation, the size of necrotic areas, mycobacterial content, or the incidence of CD4+ cells and CD8+ cells.