Figure 1.
IFN-α/β inhibition of IL-12 and IFN-γ protein production in vitro. The effects of IFN-α, IFN-β, or IL-2 on SAC-induced IL-12, IFN-γ, TNF, and IL-6 production were examined in culture after 24 hr stimulation of 1 × 106 splenic leukocytes isolated from C57BL/6 mice. Stimulation with SAC was carried out with 0.12% (□), 0.03% (▵), and 0.004% (⋄), or no (•) SAC as specified. Serial dilutions of purified natural IFN-α, IFN-β, or human recombinant IL-2 were added to the test conditions as indicated. Culture supernatant fluids were prepared, and production of IL-12 p40, IFN-γ, TNF, or IL-6 was determined by specific protein ELISA. The following are shown: IL-2 effects on SAC-induced IL-12 p40 (A), IFN-α (B) and IFN-β (C) effects on SAC-induced IL-12 p40, IL-2 effects on SAC-induced IFN-γ (D), IFN-α (E) and IFN-β (F) effects on SAC-induced IFN-γ production, and IFN-α effects on SAC-induced IL-12 p40 (G), TNF (H), and IL-6 (I). The confidence limit of detection for assays is indicated (dotted line).