Results
3.1. Cytosolic DNA induces IFN-b mRNA in chicken macrophages
To determine whether introduction of cytosolic DNA induces
chicken type I IFN expression, chicken HD-11 macrophage-like cells
were electroporated with calf thymus (CT) DNA and also the synthetic
dsRNA, poly(I:C), a known inducer of chicken IFN-b via
cytosolic recognition (Karpala et al., 2011) (Fig. 1A). An initial
experiment used 20 mg of DNA or poly(I:C), but after finding that
the DNA compromised viability, subsequent experiments used 5 mg.
IFN-b mRNA was clearly induced by both DNA and poly(I:C), with
the DNA response peaking at 4 h post electroporation. Poly(I:C)
gave a low induction of IFN-a, whereas the DNA response was
minimal or absent (Fig. 1A). The primers for IFN-a were designed to
the currently annotated IFNA3 transcript (NM_205427.1), but will
recognise other predicted IFNA transcripts. However, the IFNA loci