STAPHYLOCOCCAL-ENTEROTOXIN-B MODULATES V-BETA-8(-ASSOCIATED T-CELL MEMORY AGAINST CONVENTIONAL ANTIGEN() TCR)

Primary in vivo challenge with the superantigen staphylococcal enterot oxin B (SEB) induces polyclonal proliferation of an unusually large pr oportion of circulating T-cells that bear the V beta 8-T-cell receptor (TcR) domain. Early and vigorous proliferation of V beta 8(+) T-cells precedes their selective deletion, leaving the host unresponsive upon rechallenge with the native immunogen SEB. Nonetheless, this inductio n of anergy is incompletely understood, Recently we demonstrated that more cells than just V beta 8(+) T-cells undergo clonal proliferation after challenge with SEE (Cell. Immunol. 154, 440, 1994). These findin gs suggested that non-V beta 8(+) T-cells may have a role in the induc tion of superantigen-induced anergy. To further investigate this, we e numerated CD4(+) and CD8(+) T-cells in lymph nodes and spleens from Ba lb/c mice at various times after primary and secondary challenge with either a high or a low dose of SEB. Using these kinetic data we invest igated whether challenge with SEB would modulate antigen-specific V be ta 8-associated T-memory responses. To this end, the V beta 8(+) T-cel l-associated responses induced by SEE were compared with the V beta 8( +) TcR-associated memory responses induced by the nominal antigen sper m whale myoglobin (SWM). Results indicated that challenge of SWM-prime d mice with SEE abrogated the V beta 8-associated SWM-specific T-cell memory for an extended but transient period of time. Moreover, prechal lenge with SEE blocked the establishment of de novo V beta(+) T-cell-m ediated immunity. These findings suggest that administration of low an d controlled doses of microbial superantigen could provide long-term s uppression of antigen-specific cell-mediated immunity. (C) 1995 Academ ic Press, Inc.