Effect of cyclosporin A on the T-effector and T-suppressor cell response in contact sensitivity

The effect of cyclosporin A (CyA) on the induction, expression and regulation of the immune response to the contact sensitivity agent 2,4-dinitroflouro-benzene, (DNFB) has been studied in BALB/c mice. CyA was administered orally during the sensitization phase or during the elicitation phase. The following results were obtained. CyA administered orally during the sensitization phase at a high dose resulted in a reduction of the contact sensitivity response. Feeding lower doses had no effect on the ear swelling response. CyA inhibited the ear swelling response if administered during the elicitation phase. In transfer experiments it was shown that the induction of the T-effector cell of delayed hypersensitivity (TDH) was insensitive to the suppressive action of CyA, while the effector function of this T-cell subpopulation was CyA-sensitive. T-suppressor (TS) cell response was studied in animals by inducing tolerance through epicutaneous application of an allergen overload and by transfer of TS cells induced by intravenous injection of the contact sensitizer. Tolerance induction in vivo and TS-cell induction and function were inhibited in CyA-treated animals.