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

Figure 2

Early synergistic elevation of LPS-stimulated IL-10 expression by the cAMP pathway in BMDM and in vivo is diminished with time. (a) BMDM from C57BL/6 mice were incubated with LPS (10 ng/ml) and/or isoproterenol (Iso, 1 μM) for up to 24 h. The medium was collected, and secretion of endogenous IL-10 was measured by ELISA. Data represent the (). Values of isoproterenol treatment were indistinguishable from control values. for LPS+Iso relative to either LPS or control and for LPS relative to control, at all time points. (b) BALB/c mice were IP-injected with the cAMP inducer PCERA-1 (1 mg/kg) or with vehicle 30 min prior to IP administration of LPS (5 mg/kg). Blood was collected at the indicated time points. IL-10 and TNFα serum levels were measured by ELISA. Data expressed as the ( for -1.5 h, for other time points). for LPS+PCERA-1 relative to LPS only at 1-2 h in the IL-10 assay (b, left) and at 1-3.5 h in the TNFα assay (b, right). Cytokine levels were undetected following administration of PCERA-1 alone or vehicle. The experiments were carried out twice.

(a)

(b)