Abstract
4-Hydroxy-3-nitrophenyl acetyl (NP)-derivatized syngeneic spleen cells administered intravenously induced a population of suppressor T cells that could suppress mice previously primed to NP. The effect was demonstrable when the suppressor cells were transferred to NP-primed mice on the day of challenge for delayed-type hypersensitivity (DTH) responses. In contrast to the suppressor T cell population, which abrogates 5-iodo derivative of NP (NIP)-specific DTH responses when administered before antigen priming, the effector-phase suppressors did not efficiently suppress NIP-specific DTH responses, and were not lysed by treatment with antiidiotype plus complement. Adoptive transfer experiments between major histocompatibility complex and allotype congenic strains of mice allowed demonstration of both Igh-V and I-A restrictions in the transfer of this cell population. The implications of these data in terms of network theories and proposed cellular models for negative immunoregulation were discussed.