Modulation of suppressor mechanisms in allergic contact dermatitis: 2. Inhibition of suppressor T-lymphocytes by Corynebacterium parvum.

Pretreatment of BALB/c mice with Corynebacterium parvum inhibited the induction of tolerance to the contact sensitizing agent 2,4-dinitrofluorobenzene induced by intravenous injection of DNBSO3. The suppressive effect on tolerance induction has further been analyzed by adoptive transfer experiments. Injection of C. parvum intraperitoneally (0.7-2.8 mg/mouse) before injection of the tolergen inhibited the generation of T-suppressor cells as shown by transfer of spleen cells from the tolerized donor to naive recipients. Pretreatment of the recipients of the suppressor T-cells from tolerized animals with C. parvum also inhibited the function of these cells in the recipient animals. Time-kinetic experiments suggested that more than one mechanism appeared to be responsible for the tolerance induced by DNBSO3; C. parvum (probably via activated macrophages) suppressed tolerance which is mediated by T-suppressor lymphocytes. These results suggest that T-suppressor lymphocytes may--similarly as T-helper cells--be modulated by an activated monocytic-phagocytic system.