Chemical Suppression of Immune Responses in Thymectomized Mice

Abstract

Potentiation of drug-induced suppression of anti-sheep-red-cell antibody formation and of homograft reactivity by adult thymectomy was investigated in mice. It was found that the effect of long-term pretreatment with very small doses of cyclo-phosphamide was most effectively enhanced in thymectomized animals. Immunosuppression induced by other treatment schedules and/or other compounds was only marginally affected, if at all, by previous thymectomy. The pattern of recovery from chemical inhibition of antibody production depended on the type of compound used, Following cyclophosphamide and azathioprine early immunosuppression and subsequent restitution of antibody titers were observed. Cortisone acetate, on the other hand, caused a delayed progressive impairment of antibody formation. The differences are due to the fact that the drugs tested possess different modes of action.