RT Journal Article SR Electronic T1 IL-10 Synergizes with Dexamethasone in Inhibiting Human T Cell Proliferation JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 915 OP 919 VO 285 IS 2 A1 Mauro Brunetti A1 Antonella Colasante A1 Nicola Mascetra A1 Mauro Piantelli A1 Piero Musiani A1 Francesca B. Aiello YR 1998 UL http://jpet.aspetjournals.org/content/285/2/915.abstract AB We have evaluated the effects of dexamethasone (Dex) alone or in combination with interleukin (IL)-10 or transforming growth factor-β1 (TGF-β1) on human T cell proliferation. Both IL-10 and TGF-β1 significantly decreased the Dex concentration needed to inhibit T cell proliferation by 50% (IC50). Dex in combination with IL-10 completely inhibited T cell proliferation, even when IL-10 alone was ineffective, as in the case of phytohemagglutinin-induced T cell proliferation. The evaluation of the results according to the isobole method displayed a potent synergistic activity between Dex and IL-10, whereas the combination of Dex with TGF-β1 was additive. IL-10, but not TGF-β1, enhanced the inhibitory effect of Dex on IL-2 production. IL-2 and IL-4 only partly antagonized the antiproliferative effect of the combinations. IL-4 was as effective as IL-2 in antagonizing the combination of Dex with TGF-β1, but significantly less effective against the combination of Dex with IL-10. IL-10 and TGF-β1 are thus able to potentiate the Dex inhibitory effect on T cell proliferation and could be regarded as potential agents for future immunosuppressive protocols. The American Society for Pharmacology and Experimental Therapeutics