ABSTRACT
Glucocorticosteroids (GC) are the true immunomodulators that can depress and enhance immune reactions. Hormone-activated GC receptors (GCR) change the transcription of many genes, resulting in modified immune responses. The direction of immunomodulation under which GC act depends on their level, the quantity and state of GCR, the amount of different cytokines and cytokine receptors and other immunoactive molecules. The modulation of proinflammatory (IL-1 beta, IL-6, TNF-alpha) cytokine production by human peripheral lymphocytes treated with a wide range of dexamethasone (10(-6)-10(-12) mol) in the serum-free culture medium was observed in the present study. Enhanced or suppressed cytokine release depends on GC doses, intermittent or continuous contact with the hormone and cell environment. The magnitude of changes in IL-1 beta and TNF-alpha production was similar (parallel stimulation or depression) while diminished TNF-alpha was observed simultaneously with enhanced IL-6 production and vice versa. The suppression of proinflammatory cytokine production by GC is well documented. The experimental conditions of increased cytokine release with dexamethasone in the serum-free culture medium can serve as a model of investigation in false results of steroid immunosuppression.
