Identification of the Zebrafish IFN Receptor: Implications for the Origin of the Vertebrate IFN System

• DOI: 10.4049/jimmunol.178.7.4385
• Publication Date: 2014-04-18T22:53:35Z
• Authors: Jean-Pierre Levraud; Pierre Boudinot; Ingrid Colin; Abdenour Benmansour; Nadine Peyrieras; Philippe Herbomel; Georges Lutfalla
• Keywords: 570; 0303 health sciences; Embryo, Nonmammalian; Transcription, Genetic; ZEBRAFISH; Molecular Sequence Data; Zebrafish Proteins; 3. Good health; Alternative Splicing; Protein Subunits; 03 medical and health sciences; [SDV.IMM]Life Sciences [q-bio]/Immunology; Animals; [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]; [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]; Amino Acid Sequence; Interferons; Promoter Regions, Genetic; Zebrafish; Receptors, Interferon

Abstract The recent description of virus-induced fish IFNs has raised questions about the evolution of this complex antiviral system. Identification of the receptor of the zebrafish virus-induced IFN (zIFN) was sought to help resolve these questions. We set up an experimental system to study the zIFN system in the course of a viral infection of zebrafish embryos. In this setting, zIFN was induced by viral infection, and we identified zIFN-dependent induced transcripts. Embryos quickly died from the infection, but zIFN overexpression increased their survival. We took advantage of this experimental system to perform in vivo loss and gain of function analysis of candidate receptors of the class II helical receptor family and identified zCRFB1 and zCRFB5 as the two subunits of the zebrafish IFN receptor. Based on the organization of the zIFN gene and the protein structure of the identified receptor components, the virus-induced fish IFNs appear as orthologs of mammalian IFN-λ, specifying type III IFN as the ancestral antiviral system of vertebrates.