Interferons (IFNs) are cytokines produced by host cells in response to the infection with pathogens. By binding to the corresponding receptors, IFNs trigger different pathways to block intracellular replication and growth of pathogens and to impede the infection of surrounding cells. Due to their key role in host defence against viral infections as well as for clinical therapies, the IFN responses and regulation mechanisms are well studied. However, studies on type I IFNs are mainly focusing on IFNα and β subtypes. Knowledge about IFNκ and ω is limited. Moreover, most of the studies are done in humans or mouse models but not in the original host of zoonotic pathogens.Bats are important re... More
Interferons (IFNs) are cytokines produced by host cells in response to the infection with pathogens. By binding to the corresponding receptors, IFNs trigger different pathways to block intracellular replication and growth of pathogens and to impede the infection of surrounding cells. Due to their key role in host defence against viral infections as well as for clinical therapies, the IFN responses and regulation mechanisms are well studied. However, studies on type I IFNs are mainly focusing on IFNα and β subtypes. Knowledge about IFNκ and ω is limited. Moreover, most of the studies are done in humans or mouse models but not in the original host of zoonotic pathogens.Bats are important reservoirs and transmitters of zoonotic viruses like lyssaviruses. A few studies have shown an antiviral activity of IFNs in fruit bats. However, the function of type I IFNs against lyssaviruses in bats is not studied yet. Here, IFNκ and IFNω genes from European serotine bat, Eptesicus serotinus, were cloned and functionally characterized. E. serotinus IFNκ and IFNω genes are intron-less and well conserved between Microchiropterean species. The promoter regions of both genes contain essential regulatory elements for transcription factors. In vitro studies indicated a strong activation of IFN signalling by recombinant IFNω, whereas IFNκ displayed weaker activation. Noticeably, both IFNs inhibit to different extents the replication of different lyssaviruses in susceptible bat cell line. The present study provides functional data on the innate host defence against lyssaviruses in endangered European bats.IMPORTANCE: In this manuscript we describe for the first time the molecular and functional characterization of two type I interferons (IFN κ and ω) from European serotine bat (Eptesicus serotinus). The importance of this study is mainly based on the fact that very limited information about the early innate immune response against bat Lyssaviruses in their natural host serotine bats is yet available. Generally, whereas the antiviral activity of other type I interferons is well studied the functional involvement of IFN κ and ω is not yet investigated.
