Expression of chMDA5(1-483) induces type I IFN.

<p>The effect of chMDA5(1-483) expression on the activation of the chIFN-β promoter (a) and on type I IFN secretion (b) was analyzed in the DF-1 fibroblast cell line (a) and in the HD-11 macrophage-like cell line (b), respectively. DF-1 cells were transfected with the reporter plasmids for measuring chIFN-β promoter activity and with the indicated expression constructs (a). The firefly and <i>Renilla</i> luciferase activities were determined 24 h later. The IFN-β promoter-induced firefly luciferase activity was normalized with the corresponding <i>Renilla</i> luciferase activity and expressed as fold induction compared to cells transfected with the empty expression plasmid (Vector). The bars represent the mean values of five independent transfections with the error bars showing the standard deviations. The graph is representative of two independent experiments. For type I IFN induction, HD-11 cells were transfected with the indicated plasmids (b). Eighteen hours later, the cell supernatants were assayed for type I IFN using the bioassay as described. The bars represent the mean values of six independent transfections with the error bars showing the standard deviations.