IFN-γ and IL-12p70 production are reduced in allogeneic cultures containing 4-OH-IF-treated DCs. DCs were treated with 4-OH-IF (100 μM) alone for 90 minutes on day 8 or with 4-OH-IF then GSH-OEt at a final concentration of 0.4 mM for 5 hours. Untreated cells were used as controls. DCs were washed and resuspended in RPMI medium plus 10% FCS and incubated with allogeneic PBLs (105/well) in 96-well plates at different PBL/DC ratios for 6 days. Results are shown for the PBL/DC ratio of 64:1. Additional controls included DC alone, 4-OH-IF-treated DCs alone, or PBLs alone. Cell culture supernatants were collected after 6 days, and (A) IFN-γ and (B) IL-12p70 levels were determined using ELISA specific for each cytokine. Results in panel A represent the mean of triplicate samples ± SD from 3 separate experiments. Results in panel B represent the mean of triplicate samples ± SD from 1 experiment. *P < .05.
