FIG 3.

esIFN-κ and esIFN-ω initiate IFN signaling in an E. serotinus brain cell line. (A) Cells were treated with either recombinant esIFN-κ and esIFN-ω MBP-tagged proteins (1 and 10 μg/ml) or MBP alone (1 and 10 μg/ml) for 3 h as described in the text. Only the higher concentration (10 μg/ml) of recombinant esIFN-ω induced a significant increase in ISG56 mRNA (*, P < 0.05), as measured by qRT-PCR. (B) Cells were transfected with esIFN-κ and esIFN-ω expression plasmids (1.2 μg/well in a 12-well plate) or poly(I·C) at 10 μg/ml as a positive control. Note that eukaryotic expressed esIFN-κ and esIFN-ω induced a much stronger ISG56 mRNA level, as measured by qRT-PCR. The expressions of Mx1 and IFIT3 were also upregulated by esIFN-ω.