title: Salmonids have an extraordinary complex type I IFN system: characterization of the IFN locus in rainbow trout oncorhynchus mykiss reveals two novel IFN subgroups.
abstract: Fish type I IFNs are classified into two groups with two (group I) or four (group II) cysteines in the mature peptide and can be further divided into four subgroups, termed IFN-a, -b, -c, and -d. Salmonids possess all four subgroups, whereas other teleost species have one or more but not all groups. In this study, we have discovered two further subgroups (IFN-e and -f) in rainbow trout Oncorhynchus mykiss and analyzed the expression of all six subgroups in rainbow trout and brown trout Salmo trutta. In rainbow trout RTG-2 and RTS-11 cells, polyinosinic-polycytidylic acid stimulation resulted in early activation of IFN-d, whereas the IFN-e subgroup containing the highest number of members showed weak induction. In contrast with the cell lines, remarkable induction of IFN-a, -b, and -c was detected in primary head kidney leukocytes after polyinosinic-polycytidylic acid treatment, whereas a moderate increase of IFNs was observed after stimulation with resiquimod. Infection of brown trout with hemorrhagic septicemia virus resulted in early induction of IFN-d, -e, and -f and a marked increase of IFN-b and IFN-c expression in kidney and spleen. IFN transcripts were found to be strongly correlated with the viral burden and with marker genes of the IFN antiviral cascade. The results demonstrate that the IFN system of salmonids is far more complex than previously realized, and in-depth research is required to fully understand its regulation and function.
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom; j.j.zou@abdn.ac.uk c.secombes@abdn.ac.uk.
authors: Jun
authors: J
authors: Zou
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom; Centre for Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Weymouth, Dorset DT48 UB, United Kingdom;
authors: Bartolomeo
authors: B
authors: Gorgoglione
authors: Centre for Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Weymouth, Dorset DT48 UB, United Kingdom;
authors: Nicholas G H
authors: NG
authors: Taylor
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom;
authors: Thitiya
authors: T
authors: Summathed
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom;
authors: Po-Tsang
authors: PT
authors: Lee
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom;
authors: Akshaya
authors: A
authors: Panigrahi
authors: Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1313, Unité de Génétique Animale et Biologie Intégrative, Jouy-en-Josas Cedex 78352, France;
authors: Carine
authors: C
authors: Genet
authors: Institute of Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China;
authors: Young-Mao
authors: YM
authors: Chen
authors: Institute of Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China;
authors: Tzong-Yueh
authors: TY
authors: Chen
authors: Zoology Department, Government College University, Lahore 54000, Pakistan;
authors: Mahmood
authors: M
authors: Ul Hassan
authors: Faculty of Fisheries and Wild Life, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan; and.
authors: Sharif M
authors: SM
authors: Mughal
authors: Institut National de la Recherche Agronomique, Unité de Virologie et Immunologie Moléculaires, Jouy-en-Josas Cedex 78352, France.
authors: Pierre
authors: P
authors: Boudinot
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom; j.j.zou@abdn.ac.uk c.secombes@abdn.ac.uk.
authors: Christopher J
authors: CJ
authors: Secombes
mesh_terms: D000818:Animals; D001483:Base Sequence; D029941:Fish Proteins / Q000235:genetics* / Q000276:immunology; D056426:Genetic Loci / Q000502:physiology*; D007370:Interferon Type I / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000276:immunology; D009928:Organ Specificity / Q000502:physiology
chemical_list: D029941:Fish Proteins; D007370:Interferon Type I