Production of Interferon‐α/β by Murine Dendritic Cell Lines Stimulated by Virus and Bacteria

The interferon-alpha and -beta (IFN-alpha/beta) producing ability of the two murine dendritic cell (DC) lines D2SC/1 and FSDC was studied. The D2SC/1 cells produced IFN-alpha and -beta when stimulated by herpes simplex virus (HSV), Sendai virus (SV) or by the bacteria Escherichia coli or Staphylococcus aureus Cowan I. Precultivating (priming) D2SC/1 cells with recombinant IFN-beta or a combination of IFN-beta and granulocyte-macrophage colony-stimulating factor increased production of IFN-alpha/beta induced by HSV or the bacteria, but not by SV. Also, the kinetics of IFN-alpha/beta responses were different for SV compared to HSV and the bacteria, suggesting different induction mechanisms. The FSDC cells differed from the D2SC/1 cells mainly in that predominantly IFN-beta was produced, that little or no IFN-alpha/beta production was induced by the bacteria, and that the IFN-alpha/beta responses were most efficiently primed by IFN-gamma. Priming the DC lines with tumour necrosis factor-alpha, interleukin-10 (IL-10) or IL-4 did not affect the IFN-alpha/beta response induced by HSV. The results show that the two DC lines provide a convenient tool to study the induction and control of the IFN-alpha/beta response, as well as the immunoregulatory role of IFN-alpha/beta produced by DC.