Effects of Methylprednisolone on the in Vitro Induction and Function of Suppressor Cells in Man

Abstract

The effects of the steroid methylprednisolone [MP] on the induction of suppressor lymphocytes in human mixed lymphocyte cultures (MLC) were examined. Concentrations of MP sufficient to inhibit both the cellular proliferation and the generation of cytotoxic lymphocytes in MLC appeared to enhance the induction of suppressor cells in these cultures. Maximum enhancement of suppressor cell induction occurred at an MP concentration of .apprx. 1 .mu.g/ml. The presence of low concentrations of MP, not sufficient to inhibit proliferation in MLC, significantly potentiated the inhibiting effect of suppressor cells on cellular proliferation. The inhibition observed by the combined effect of MP and suppressor cells was equivalent to that seen using 5 times as many suppressor cells alone.