Induction of suppressor T cells by intravenous administration of monoclonal anti-I-A antibody.

Abstract

Intravenously administered monoclonal anti-I-A antibodies successfully induced suppressor T (Ts) cells specific for alloantigen-specific delayed-type hypersensitivity (DTH) responses in mice. These Ts cells exerted their effects in the effector phase and had no H-2 restrictions. Phenotypic analysis revealed L3T4 antigens on their cell surface but failed to reveal Lyt-2 antigen. Ts cell activity was abrogated by a 30-min incubation with the anti-I-A antibodies used for Ts cell induction. Incubation in the anti-I-A-antibody-coated plate also abrogated the Ts cell activity. Since anti-I-A antibody is idiotypic for the I-A antigen, it is suggested that these Ts cells might express antiidiotypic receptors for I-A antigens. These findings are considered to be consistent with previous observations of hapten-specific systems, in which antiidiotypic Ts cells are inducible by idiotypic antibodies.