Effect of IL-10 on the half-life of TNF-RII mRNA in LPS-stimulated monocytes. Monocytes (5 × 106 cells/mL) were cultured in the presence of LPS (100 ng/mL) or LPS + IL-10 (10 ng/mL) for 4 hours. Actinomycin D (5 μg/mL) was then added and the cultures further incubated for up to 8 hours longer. At designated time points, cells were harvested and RNA extracted. Levels of TNF-RII and β-actin mRNA were determined by Northern blotting. Autoradiographic films were analyzed by laser densitometric scanning on an LKB Ultroscan XL-500. Levels of TNF-RII mRNA were normalized to β-actin and then used to plot the percent reduction of TNF-RII mRNA over time for the 2 treatment groups: LPS v LPS + IL-10. Similar results were obtained in 2 separate experiments.
