Immune responses, subcellular localization, and antiviral activity of interferon-induced protein 35 (IFP35) in rock bream (Oplegnathus fasciatus)

• Published in: Developmental and comparative immunology 2021-10, Vol.123, p.104142-104142, Article 104142
• Main Authors: Madhuranga, W.S.P., Tharuka, M.D. Neranjan, Harasgama, J.C., Kwon, Hyukjae, Wan, Qiang, Lee, Jehee
• Format: Article
• Language: English
• Subjects: Amino acids; Animals; Antiviral activity; Antiviral Agents - metabolism; Antiviral defense; Bream; Cytoplasm; DNA Virus Infections - immunology; Evolutionary conservation; Fish diseases; Fish Proteins - genetics; Fish Proteins - metabolism; Fishes - immunology; Gene expression; Gene regulation; Gills; Immune response; Immune system; Immunity; Inflammation; Inflammatory response; Interferon; Interferon Type I - metabolism; Interferon-induced protein; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Intracellular Space; Iridovirus - physiology; Lipopolysaccharide; Lipopolysaccharides; Localization; Molecular weight; Myc protein; NID domain; Oplegnathus fasciatus; Pairwise alignment; Phylogeny; Protein Transport; Proteins; Rock bream; Rocks; Sequence Alignment; Streptococcus infections; Transcription; Virus Diseases - immunology
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2021.104142

Interferon-induced protein 35 kDa (IFP35) has been demonstrated to play important roles in antiviral defense, inflammatory response and cancer progression. However, its precise function in teleost fish remains to be elucidated. Herein, we functionally characterized the rock bream (Oplegnathus fasciatus) IFP35 (OfIFP35) to understand its expression pattern, subcellular localization, antiviral activity, and regulation of downstream genes. OfIFP35 consists of an 1107 bp open reading frame encoding 368 amino acids, including two N-myc-interactor (Nmi)/IFP35 domains (NIDs). The predicted molecular weight of OfIFP35 was 42 kDa, with a theoretical isoelectric point (pI) of 5.10. Evolutionary conservation of IFP35 was analyzed using multiple, pairwise alignments and phylogenetic tree analysis. OfIFP35 in rock bream was found to be highest expressed in the gills. Immune challenges with iridovirus, polyinosinic:polycytidylic acid, lipopolysaccharide, and live bacteria (Streptococcus iniae and Edwardsiella tarda) significantly upregulated its mRNA expression in gill and liver tissues of the rock bream. GFP-tagged OfIFP35 was localized in the cytoplasm of FHM cells, and its overexpression significantly suppressed VHSV transcription in vitro. Moreover, the analysis of downstream gene expression revealed that OfIFP35 could activate the type I interferon pathway. Collectively, these findings indicate that OfIFP35 is important for the immune system of rock bream as it promotes defense responses during viral infections. •The interferon-induced protein 35 was characterized from rock bream (OfIFP35).•OfIFP35 expression was modulated upon immune challenge.•Highest level of OfIFP35 transcript was found in gill tissue.•OfIFP35 significantly suppressed the mRNA expression levels of viral hemorrhagic septicemia virus (VHSV) in vitro.•OfIFP35 regulated the IRF3, viperin, ISG15, and Mx genes expression in FHM cells.