LPS- but not CD40L-matured LXR agonist–treated DCs fail to stimulate T cells. (A) Immature DCs (iDCs) were differentiated for 7 days and left untreated (control) or treated from day 2 on with 2 μM of the LXR agonist T0901317 (T09). Mature DCs were obtained from iDCs by incubation with LPS for the last 2 days. At day 7, immature and LPS-matured DCs were washed extensively, irradiated, and cocultured with 1 × 10⁵ allogeneic purified CD4⁺ T cells at the indicated ratios. After 4 days, proliferation was measured by [³H]-thymidine incorporation in 4 independent experiments. (B) Allogeneic MLRs were performed as described for panel A using LPS- and CD40-matured DCs, respectively. *P ≤ .05 for difference between T09-treated versus untreated DCs. Data show the means and SEM of 4 independent experiments.