DEXAMETHASONE MODULATES CD2 EXPRESSION

Glucocorticoid hormones (GCs) are able to modulate leukocyte activity. We studied the effect of dexamethasone (DEX) on the expression of CD2 , an adhesion molecule involved in T-lymphocyte homing and activation. Results of flow cytometry analysis and immunoprecipitation with anti- CD2 monoclonal antibodies (mAbs) indicated that in vitro treatment wit h DEX augments CD2 expression in transformed T-cell lines. This effect correlated with a rapid increase in the mRNA and was inhibited by act inomycin-D (AD). The DEX-induced CD2 augmentation was transient, peake d at days 1-2 and returned to the levels of untreated controls al days 3-4. It was a dose-dependent phenomenon, mediated by the GC receptor (GCR), because it was inhibited by the GCR antagonist RU486, and was n ot induced by other steroids such as testosterone and progesterone. Th is CD2 modulation could presumably contribute to GC-induced effects on T-cell activity. (C) 1997 International Society for Immunopharmacolog y.