An investigation of the nature of induced suppression to experimental autoimmune thyroiditis

When mice are pretreated with soluble mouse thyroglobulin (MTg), subsequent induction of autoantibodies in experimental allergic thyroiditis (EAT) is suppressed. This suppression can be reproducibly transferred to low-level irradiated syngeneic recipients and is specific for MTg. Injection of normal cells does not reverse this tolerance, also indicative of an active suppression. Neither can the induced unresponsiveness be overcome by immunization with cross-reactive xenogeneic Tg; although antibodies are formed which will bind to MTg, these are not to epitopes to which antibodies are normally formed on immunization or towards which tolerance is induced. This implies that tolerance might be induced at least at the B-cell level, a view supported by the inability of DNP to provide a new carrier to break tolerance when conjugated to MTg. The poorer response to DNP in these animals also suggests anergy of the MTg-specific T helpers.