Figure 4. C-di-AMP induces IFN-β production in murine dendritic cells (DCs).

(A) C-di-AMP targets the IFNB promoter in DCs and monocytes/macrophages/granulocytes in vivo. Mice of indicated phenotypes were i. n. treated with c-di-AMP: “CD4+” indicates T cell specific, “CD19+” B cell specifc, “LysM+” monocyte/macrophage/granulocyte specific, and “CD11c+” DC specific control of luciferase expression by the IFN-β promoter. Quantification of in vivo imaging signals derived from luciferase activity at different time points is shown for n = 5. Results are expressed as average of radiance (in photons/s/cm²/steridian). Error bars are SEM. (B) C-di-AMP induces IFN-β production in DCs in vitro. BMDCs were cultured in the presence of GM-CSF or Flt3l, as indicated on the x axis. IFN-β secretion was determined in the culture medium by ELISA. Error bars are SEM, n = 3.