Infection and microbial molecular motifs modulate transcription of the interferon-inducible gene ifit5 in a teleost fish

• Published in: Developmental and comparative immunology 2020-10, Vol.111, p.103746-103746, Article 103746
• Main Authors: Bela-ong, Dennis Berbulla, Greiner-Tollersrud, Linn, Andreas van der Wal, Yorick, Jensen, Ingvill, Seternes, Ole Morten, Jørgensen, Jorunn B.
• Format: Article
• Language: English
• Subjects: Atlantic salmon; Ifit5; Interferon; Matematikk og Naturvitenskap: 400; Mathematics and natural science: 400; Mx1; Piscirickettsia salmonis; Salmonid alphavirus; VDP; Zoologiske og botaniske fag: 480; Zoology and botany: 480
• ISSN: 0145-305X; 1879-0089; 1879-0089
• DOI: 10.1016/j.dci.2020.103746

Interferon-induced proteins with tetratricopeptide repeats (IFITs) are involved in antiviral defense. Members of this protein family contain distinctive multiple structural motifs comprising tetratricopeptides that are tandemly arrayed or dispersed along the polypeptide. IFIT-encoding genes are upregulated by type I interferons (IFNs) and other stimuli. IFIT proteins inhibit virus replication by binding to and regulating the functions of cellular and viral RNA and proteins. In teleost fish, knowledge about genes and functions of IFITs is currently limited. In the present work, we describe an IFIT5 orthologue in Atlantic salmon (SsaIFIT5) with characteristic tetratricopeptide repeat motifs. We show here that the gene encoding SsaIFIT5 (SsaIfit5) was ubiquitously expressed in various salmon tissues, while bacterial and viral challenge of live fish and in vitro stimulation of cells with recombinant IFNs and pathogen mimics triggered its transcription. The profound expression in response to various immune stimulation could be ascribed to the identified IFN response elements and binding sites for various immune-relevant transcription factors in the putative promoter of the SsaIfit5 gene. Our results establish SsaIfit5 as an IFN-stimulated gene in A. salmon and strongly suggest a phylogenetically conserved role of the IFIT5 protein in antimicrobial responses in vertebrates. [Display omitted] •Atlantic salmon possesses ifit5 and ifit5-like genes.•Predicted protein of one SsaIfit5 exhibits tetratricopeptide repeat motifs.•ISRE motifs are present in the putative promoter of SsaIfit5.•SsaIfit5 transcription is upregulated by infection, type I IFNs, and TLR ligands.•SsaIfit5 is an interferon-stimulated gene in A. salmon.