Clonal expansion precedes anergy and death of Vβ8+ peripheral T cells responding to staphylococcal enterotoxin B in vivo

Abstract

Staphylococcal enterotoxin B (SEB) selectively stimulates T cells bearing T cell receptor V_β8 domains and hence provides a useful model to study immunity and tolerance in vivo. We show here that V_β8⁺ T cells in both CD4⁺ and CD8⁺ subsets expand dramatically (fivefold) in lymphoid tissues of mice 2–4 days following injection with SEB. This initial clonal expansion, which is accompanied by a transient hyper-reactivity to SEB, is followed by a rapid decrease in V_β8⁺ cells and a concomitant induction of specific non-responsiveness which persists for at least 30 days. Selective death of V_β8⁺ cells occurs during this latter phase. Taken together, our data indicate that clonal expansion, anergy and death can occur as sequential stages of an immune response in vivo.