Definition of two pathways for generation of suppressor T-cell activity

Antigen-stimulated Ly1 cells induce T cells from nonimmune donors to develop potent feedback suppressive activity. Suppression is mediated by Ly23 suppressor T (Ts) cells, which are generated from either Ly23 or Ly123 precursors. Ts activity generated from Ly23 precursors requires a strong inducer signal and is rapidly expressed but short lived. In contrast, Ts activity from Ly123 precursors is relatively long lived and is efficiently generated by relatively low levels of inducer signals. Induction of both Ly123 and Ly23 precursors to become Ts cells requires that both cells share genes linked to the Ig-H locus.