IL-10-mediated inhibition of increased IL-12p40 and TNFα mRNA accumulation and protein secretion in BMDCs. BMDCs from WT and IL-10^-/- mice were stimulated with LPS (5 μg/mL) in the presence or absence of IL-10 (10 ng/mL). (A) IL-12p40 secretion at 24 hours, (B) TNFα secretion at 24 hours as measured in triplicate supernatants by enzyme-linked immunosorbent assay (ELISA). Error bars represent standard error of the mean (SEM). (C) IL-12p40 and IL-10 mRNA levels as determined by RT-PCR in RNA isolated from 12-hour LPS-stimulated BMDCs. In some samples, IL-10 receptor antibody or isotype control IgG (30 μg/mL) was used for blockade of the IL-10 receptor. The results are representative of 3 independent experiments.