Specific immunosuppression byTrichinella: fine specificity and effect on lymphocyte functionin vivo

Abstract

Muscle-phaseTrichinellalarvae depress the immune response of mice to the phosphorylcholine (PC)-bearingTrichinellaantigen FCp without affecting responses to other PC-bearing or non-PC antigens. The depressive activity is independent of antigen dose andTrichinellaspecies and, in adoptive cell transfer experiments with lethally irradiated recipient mice, depended on the state of the recipient (infected recipients had a depressed response even a month after their encysted larvae had been killed and regardless of whether the donor had been exposed to FCp) but not on the state of the transferred cells. We conclude that lymphocytes are not permanently altered by the depressive action, that the agent responsible persists in the host at least a month after the death of the encystedTrichinellalarvae, and that the alteration does not eliminate lymphocyte immunological memory.