Avian Interferons and Their Antiviral Effectors

Abstract

Interferon (IFN) responses, mediated by a myriad of IFN-stimulated genes (ISGs), are the most profound innate immune responses against viruses. Cumulatively, these IFN effectors establish a multilayered antiviral state to safeguard the host against invading viral pathogens. Considerable genetic and functional characterizations of mammalian IFNs and their effectors have been made, and our understanding on the avian IFNs has started to expand. Similar to mammalian counterparts, three types of IFNs have been genetically characterized in most avian species with available annotated genomes. Intriguingly, chickens are capable of mounting potent innate immune responses upon various stimuli in the absence of essential components of IFN pathways including retinoic acid-inducible gene I, IFN regulatory factor 3 (IRF3), and possibility IRF9. Understanding these unique properties of the chicken IFN system would propose valuable targets for the development of potential therapeutics for a broader range of viruses of both veterinary and zoonotic importance. This review outlines recent developments in the roles of avian IFNs and ISGs against viruses and highlights important areas of research toward our understanding of the antiviral functions of IFN effectors against viral infections in birds.

Duck karyopherin α4 (duKPNA4) is involved in type I interferon expression and the antiviral response against Japanese encephalitis virus

“…In ducks, the toll-like receptor signaling pathway and the retinoic-acid-inducible gene I signaling pathway largely resemble the human pathways (Evseev and Magor, 2019) and play essential roles in the regulation of type I IFN expression and host antiviral response (Yu and Levine, 2011). Notably, IRF3, as a downstream molecule in the toll-like receptor signaling pathway and the retinoicacid-inducible gene I signaling pathway, is absent in ducks, and duIRF7 instead performs most functions of IRF3 in inducing type I IFN expression (Santhakumar et al, 2017). In the current study, duKPNA4 interacted with duIRF7 and facilitated the nuclear translocation of duIRF7.…”

Acute phase protein response to viral infection and vaccination

“…Like mammals, birds possess an innate immune system as the first barrier of defense against pathogens [65]. Therefore, birds are capable of mounting a rapid response upon viral infection [66]. The magnitude of the response may vary among species: avian H5N1 influenza virus causes a rapid elevation of SAA levels in chicken but not in ducks [53], which may explain the lesser mortality rates and less severe disease in ducks compared to chicken.…”

Interferons: application in veterinary medicine

“…Інтерферон каппа, експресований у ку-рячих клітинах, проявляв противірусну дію щодо вірусів, які містять РНК, як у дослідах in vitro (культура первинних фібробластів), так і ex vivo (культури тканинних органів), а також і in ovo (курячі ембріони) [102].…”