SPECIFIC RECOGNITION OF STAPHYLOCOCCAL ENTEROTOXIN-A BY HUMAN T-CELLS BEARING RECEPTORS WITH THE V-GAMMA-9 REGION

T CELLS bearing the αβ receptor can specifically react with target cells coated with staphylococcal enterotoxin and expressing major histocompatibility complex class II molecules; these responses depend on which variable region (V) of the receptor's β-subunit is used1-7. We have now examined whether a similar situation exists for human T cells bearing the γδ receptor. We found that reactivity to staphylococcal enterotoxin A is strictly dependent on the presence of the Vγ9 variable region in the γδ T-cell receptor (TCR). These cytotoxic responses required the expression of HLA class II molecules by the target cell and could be inhibited by anti-γδTCR and by anti-HLA-class-II monoclonal antibodies. In contrast to αβTCR+ cell clones, no proliferate response of Vγ9+ T-cell clones towards stimulator cells coated with enterotoxin A was observed in vitro. These results indicate that the γδTCR repertoire might be influenced by enterotoxin A produced during staphylococcal infections in vivo. This could provide a molecular basis for the observation that Vγ9+ T cells form the large majority of peripheral γδTCR+ cells but only a small proportion of thymic γδTCR+ cells. © 1990 Nature Publishing Group.