The cAMP Pathway Amplifies Early MyD88-Dependent and Type I Interferon-Independent LPS-Induced Interleukin-10 Expression in Mouse Macrophages

Figure 3

The insensitivity of late-phase IL-10 induction to isoproterenol does not result from partial receptor desensitization. (a, b) RAW264.7 macrophages were transfected with a luciferase reporter regulated by 4 repeats of a consensus CRE sequence. Luciferase reporter data expressed as the () of values normalized against Renilla luciferase activity, relative to unstimulated control cells. (a) The cells were preincubated for 21 h with either LPS (10 ng/ml) or vehicle, washed and further incubated for the following 3 h with isoproterenol (Iso, 1 μM) and/or LPS (10 ng/ml). (b) The cells were treated for 3 h or 24 h with isoproterenol (Iso, 1 μM) or with the PDE4 inhibitor rolipram (20 μM). . (c) RAW264.7 macrophages were incubated for the indicated time with LPS (10 ng/ml) in the presence or absence of the PDE4 inhibitor rolipram (20 μM). IL-10 and TNFα secretion was measured by ELISA. Data expressed as the (). for LPS+rolipram relative to LPS alone at all time points except for IL-10 at 24 h. The experiments were carried out twice (a, c) or three times (b) with similar results.

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