Modulation of HLA-DR expression on CD14HIGH and CD14LOW monocytes by IL-10 or hydrocortisone. Blood samples from healthy donors were incubated for 24 hours without or with IL-10 (10 ng/ml), hydrocortisone (HC, 100 μM), and/or RU486 (20 μM), an antagonist of the glucocorticoid receptor. For both subpopulations, the results are expressed as percent change of mean fluorescence intensity for HLA-DR measured in untreated cells (control). The results are the mean ± SEM of five independent experiments with different donors. * P < 0.05, ** P < 0.01 compared with control by Mann-Whitney U-test.