Figure 1.
sST2 inhibits the LPS-induced cytokine production of iMDDCs. (a) Time course of IL-6 secretion. iMDDCs (2.5×105/well) were pre-treated for 1 h with or without sST2 (100 ng/ml), and then the cells were stimulated with LPS (100 ng/ml) for 24 or 48 h. The amount of IL-6 was determined by ELISA. (b) Time course of IL-12p40 secretion was measured as described in (a). (c) Dose dependency of the inhibitory effect of sST2 was tested at various concentrations (1, 10 and 100 ng/ml) against IL-6 production for 24 h after LPS stimulation. (d) Dose dependency of sST2 to IL-10 was also tested as (c). (e) Possible cytotoxicity of sST2 was assayed by measuring the amount of ATP in iMDDCs (3×104/well) by the luciferase light-emitting method. The data are presented as the means of five experiments±s.d. Asterisks denote a statistically significant difference (*P<0.05). ATP, adenosine triphosphate; ELISA, enzyme-linked immunosorbent assay; IL, interleukin; iMDDC, immature monocyte-derived dendritic cell; LPS, lipopolysaccharide; sST2, soluble ST2 protein.