CLONAL EXPANSION PRECEDES ANERGY AND DEATH OF V-BETA-8+ PERIPHERAL T-CELLS RESPONDING TO STAPHYLOCOCCAL ENTEROTOXIN-B INVIVO

Staphylococcal enterotoxin B (SEB) selectively stimulates T cells bearing T cell receptor V-beta-8 domains and hence provides a useful model to study immunity and tolerance in vivo. We show here that V-beta-8+ 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-beta-8+ cells and a concomitant induction of specific non-responsiveness which persists for at least 30 days. Selective death of V-beta-8+ 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.