Salp15 Binding to DC-SIGN Inhibits Cytokine Expression by Impairing both Nucleosome Remodeling and mRNA Stabilization (original) (raw)
Figure 4
Salp15 Destabilizes IL-6 and TNF-α mRNA and Impairs Nucleosome Remodeling at the IL-12p35 Promoter
(A) Salp15 destabilizes IL-6 and TNF-α mRNA. DCs were stimulated with Salp15 and LPS for 6 h. Actinomycin D (ActD) was added to block new mRNA synthesis. Cells were harvested for 2 h to determine mRNA half-life. IL-12p35 mRNA stability remained unaltered in the presence of Salp15, whereas IL-6 and TNF-α mRNA half-life was strongly reduced. This was completely restored using Raf (GW5074) or MEK (U0126) inhibitors. Bars represent the mean of two independent experiments ± SE. ND: Not determined.
(B) IL-12 inhibition by Salp15 is a result of decreased nucleosome remodeling at the IL-12p35 promoter. Cells were stimulated as described before and harvested. Using enzymatic digestion, nucleosome remodeling was measured by quantitative real time PCR. Results are expressed as a percentage of the remodeling observed in EcoRI-digested samples. The decreased remodeling induced by Salp15 could be completely restored using Raf (GW5074) or MEK (U0126) inhibitors. Results represent results from one donor.