Autocrine generation of active GC during DC differentiation inhibits subsequent immunostimulatory potential. (A) Monocytes were cultured in the presence of IL-4/GM-CSF with vehicle or 10^-7 M cortisol or 10^-7 M cortisone ± GA for 7 days and then exposed to TNF-α for 48 hours. Flow cytometric histograms show log fluorescence staining of CD83 (bold line) versus that of isotype control (dotted line). Figures top right indicate mean cellular fluorescence. Data are representative of 3 independent experiments. (B) DCs were cultured as in panel A, washed extensively, and then used in allogeneic mixed leukocyte reactions (in the absence of GC) with 0.2 to 3.0 × 10⁴ irradiated DCs and 1 × 10⁵ CD4⁺CD45RA⁺ T-cell responders. Proliferation was measured in counts per minute (cpm) on day 5 by incorporation of [³H]-thymidine; symbols represent mean ± SEM proliferation (^*P < .05 proliferation cortisone versus cortisone plus GA, n = 3). (C) DCs were cultured as in panel A and then cocultured with CD40L-expressing fibroblasts for 48 hours. At 48 hours, culture supernatants were obtained, and IL-12p70 levels were measured by ELISA. Bars represent mean ± SEM IL-12p70 production (^*P < .01 paired t test for both cortisone and cortisol pretreatment versus control, ^*P = .05 paired t test cortisone versus cortisone plus GA).