Figure 3.

EP decreases the IFN-I response in LPS-stimulated DCs. DCs were pre-treated with 10mM EP for 1 h before LPS 100 ng/ml. Cells were harvested after (A) 1 h for Ifnb level of expression and (B–E) 6 h for the IFN-I-stimulated gene expression analysis by real-time RT-PCR. Values were expressed as fold difference in mRNA from the control (untreated cells). (F) CXCL10 ELISA from 24 h culture supernatants. Results in (A) are the average of biological replicates from 1 representative of 5 independent experiments (n = 5). Results in (B–E) are from 10 independent experiments (n = 10) and in (F) from 5 independent experiments (n = 5). Results are expressed as mean ± SEM. (G) EP reduces the ability of DCs to stimulate an allogeneic T cell response in the MLR assay. We treated DCs with LPS ± EP pre-treatment for 24 h, then we washed and used them as APCs to induce lymphocyte proliferation in an in vitro MLR assay. We used a DC:splenocyte ratio of 1:30. Lymphocyte proliferation was measured by ³H thymidine incorporation. Stimulation index was calculated by dividing the counts per minute (cpm) for each condition by the cpm of lymphocytes exposed to untreated DCs. Results are from 3 to 4 biological replicates of 2 independent experiments (n = 2, 7 data numbers). Data was analyzed using the two-tailed unpaired Student's t-test. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.