Biological effects of chicken type III interferon on expression of interferon-stimulated genes in chickens: comparison with type I and type II interferons.

Interferons (IFNs) are key mediators that activate host defense mechanisms against viruses. The recently identified mammalian Type III IFN has biological effects similar to type I IFN. However, the biological effects of type III IFN have not yet been characterized in birds. We compared the effects of chicken type III IFN (IFN-λ) with type I (IFN-β) and type II (IFN-γ) IFNs on IFN-stimulated genes (ISGs) using recombinant proteins expressed in Escherichia coli. Recombinant chicken IFN-λ inhibited influenza virus replication and induced the mRNA expression of the ISGs, Mx and OAS, in chicken embryonic fibroblasts (CEFs) in a dose-dependent manner. However, the effective dose of IFN-λ was higher than that of IFN-β and IFN-γ. Furthermore, the effect of IFN-λ on induction of Mx and OAS was lesser than that of IFN-β, but comparable to that of IFN-γ. These results indicate that chicken IFN-λ has the potential to induce ISGs and inhibit viral replication in chicken cells.