The interferon system of teleost fish

Expression regulation and functional characterization of a novel interferon inducible gene Gig2 and its promoter

“…In teleost fish, an acid-resistant IFN-like activity can be detected in many fish organs or fish cells upon virus infection (Robertsen, 2006;Zhang et al, 2007). Recently IFN genes (referred to as type I IFN in this study) have been characterized from several different fish species including zebrafish (Altmann et al, 2003), pufferfish (Lutfalla et al, 2003), channel catfish (Long et al, 2004), Atlantic salmon (Robertsen et al, 2003) and rainbow trout .…”

“…Recently IFN genes (referred to as type I IFN in this study) have been characterized from several different fish species including zebrafish (Altmann et al, 2003), pufferfish (Lutfalla et al, 2003), channel catfish (Long et al, 2004), Atlantic salmon (Robertsen et al, 2003) and rainbow trout . All identified fish IFNs have genomic structures similar to mammalian type III IFN (IFN-) but protein sequences homologous to type I IFN (IFN-␣/␤) (Robertsen, 2006). Type II IFNs (IFN-␥) are most conserved, and they have been described in many fish species (Zou et al, 2005;Igawa et al, 2006).…”

Fish virus-induced interferon exerts antiviral function through Stat1 pathway

“…In teleost fish, virus infection results in production of an acid-resistant IFN-like activity (Robertsen, 2006). Recently virusinduced IFN genes have been characterized in various fish species (Aggad et al, 2009;Altmann et al, 2003;Long et al, 2004;Lutfalla et al, 2003;Robertsen et al, 2003;Zou et al, 2007), and some downstream ISG counterparts have also been identified (Robertsen, 2006;Zhang et al, 2007), strongly indicating that teleost fish possess an IFN antiviral system.…”

“…Recently virusinduced IFN genes have been characterized in various fish species (Aggad et al, 2009;Altmann et al, 2003;Long et al, 2004;Lutfalla et al, 2003;Robertsen et al, 2003;Zou et al, 2007), and some downstream ISG counterparts have also been identified (Robertsen, 2006;Zhang et al, 2007), strongly indicating that teleost fish possess an IFN antiviral system. In support of this notion, IFN inducible genes including Mx and PKR have been proved to block virus replication in fish (Caipang et al, 2003;Larsen et al, 2004;Zhu et al, 2008), and there exists a conserved RLR (RIG-I-like receptors) pathway responsible for fish IFN induction during virus infection (Biacchesi et al, 2009).…”

“…In support of this notion, IFN inducible genes including Mx and PKR have been proved to block virus replication in fish (Caipang et al, 2003;Larsen et al, 2004;Zhu et al, 2008), and there exists a conserved RLR (RIG-I-like receptors) pathway responsible for fish IFN induction during virus infection (Biacchesi et al, 2009). Fish virus-induced IFNs exhibit more homology to mammalian type I IFN molecules on the basis of protein sequence identity, but they are not clearly an ␣-or ␤-IFN (Robertsen, 2006;Robertsen et al, 2003). However, the genome structure analysis shows that these IFN molecules are more evolutionally similar to type III IFN due to the presence of introns (Lutfalla et al, 2003) and, importantly, no intronless IFN gene has been reported in fish to date.…”