Figure 6. IFNα modulates TNFα responses in human Mϕ.

A-B, CD14+ macrophages isolated from the synovial fluids of 9 patients with RA were lysed immediately after purification or cultured overnight (12 hours) in the absence or presence of IFNAR antibodies (2 μg/ml); mouse IgG_2a (2 μg/ml) was used as an isotype control. The expression of IL-8 mRNA and MMP9 mRNA was measured using real time PCR and normalized relative to GAPDH mRNA. The Friedman test followed by post-hoc analysis with the Wilcoxon matched-pairs signed rank test was used for statistical analysis. C, CD14+ cells isolated from the peripheral blood of 3 healthy donors were cultured in the presence or absence of IFNα (10,000 U/ml) for 48 hours and were then stimulated with TNFα (10 ng/ml) for 3 hours. The expression of IL8 mRNA and MMP9 mRNA was measured using real time PCR and normalized relative to GAPDH mRNA. Relative mRNA levels are expressed as a percentage of gene induction following TNFα stimulation alone, which was set at 100%. A paired Student's t test was used for statistical analysis. (*=p<0.05, **=p<0.01, ***=p<0.001)