Prevention of the immunosuppressive effects of glucocorticosteroids by cell-free factors from adjuvant-activated accessory cells.

Cultured mouse spleen cells are protected from the immunosuppressive effects of glucocorticosteroid hormones by prior treatment with bacterial adjuvants. The mechanisms by which such protection is acquired were further invgestigated in this study. Cell-free factors, termed glucocorticosteroid response modifying factors (GRMF), were obtained from the supernatant fluid of normal resident murine peritoneal macrophages activated in vitro by treatment with lipopolysaccharide. These factors provided protection against steroid immunosuppression in a dose dependent fashion. Two-step experiments show that GRMF treatment results in the recovery of significant amounts of T helper activity which otherwise is suppressed by steroids. Factors with similar biologic activities were also obtained from murine monocytic cell lines. The possible mechanisms by which GRMF protects the immune response are discussed.