Suppressor T cells in mice made unresponsive to skin allografts

We have induced suppressor T cells (Ts), capable of delaying allogeneic skin graft rejection, through the intravenous administration of allogeneic spleen cells under normal conditions. H-2 and non-H-2 incompatibility between recipient mice and donor skins induced strong graft rejection. However, when the Ts were transferred into recipient mice, the mean survival time was prolonged for every combination between recipient mice and donor skin. Studies using several strains of congenic mice revealed the antigen specificity of these Ts. Treatment with monoclonal anti-Lyt-2.2 or anti-Thy-1.2 antibody and complement abolished the suppression shown by the Ts of skin graft rejection. The suppression induced by these Ts, however, was resistant to treatment with monoclonal anti-Lyt-1.2, anti-L3T4, or anti-I-A antibody and complement. These results showed that the Ts were Lyt-1-2+, L3T4-, Ia-, T cells.