title: Identification and expression analysis of two interleukin-23α (p19) isoforms, in rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar.
abstract: Interleukin (IL)-23 is a heterodimeric IL-12 family cytokine composed of a p19 α-chain, linked to a p40 β-chain that is shared with IL-12. IL-23 is distinguished functionally from IL-12 by its ability to induce the production of IL-17, and differentiation of Th17 cells in mammals. Three isoforms of p40 (p40a, p40b and p40c) have been found in some 3R teleosts. Salmonids also possess three p40 isoforms (p40b1, p40b2 and p40c) although p40a is missing, and two copies (paralogues) of p40b are present that have presumably been retained following the 4R duplication in this fish lineage. Teleost p19 has been discovered recently in zebrafish, but to date there is limited information on expression and modulation of this molecule. In this report we have cloned two p19 paralogues (p19a and p19b) in salmonids, suggesting that a salmonid can possess six potential IL-23 isoforms. Whilst Atlantic salmon has two active p19 genes, the rainbow trout p19b gene may have been pseudogenized. The salmonid p19 translations share moderate identities (22.8-29.9%) to zebrafish and mammalian p19 molecules, but their identity was supported by structural features, a conserved 4 exon/3 intron gene organisation, and phylogenetic tree analysis. The active salmonid p19 genes are highly expressed in blood and gonad. Bacterial (Yersinia ruckeri) and viral infection in rainbow trout induces the expression of p19a, suggesting pathogen-specific induction of IL-23 isoforms. Trout p19a expression was also induced by PAMPs (poly IC and peptidoglycan) and the proinflammatory cytokine IL-1β in primary head kidney macrophages. These data may indicate diverse functional roles of trout IL-23 isoforms in regulating the immune response in fish.
authors.affiliation: Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK; College of Fishery and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Yousheng
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK.
authors.forename: Mansourah
authors.initials: M
authors.lastname: Husain
authors.affiliation: Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK; Key Laboratory of Aquaculture and Ecology of Coastal pool in Jiangsu Province, Department of Ocean Technology, Yancheng Institute of Technology, Yancheng, Jiangsu 224051, China.
authors.forename: Zhitao
authors.initials: Z
authors.lastname: Qi
authors.affiliation: Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK; Molecular Genetics, School of Science, University of Waikato, Hamilton, New Zealand.
authors.forename: Steve
authors.initials: S
authors.lastname: Bird
authors.affiliation: Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK. Electronic address: t.h.wang@abdn.ac.uk.
authors.forename: Tiehui
authors.initials: T
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005091:Exons; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000097:blood / Q000235:genetics* / Q000276:immunology; D015870:Gene Expression; D006066:Gonads / Q000276:immunology / Q000382:microbiology; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D053760:Interleukin-23 Subunit p19 / Q000097:blood / Q000235:genetics* / Q000276:immunology; D007438:Introns; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010457:Peptidoglycan / Q000494:pharmacology; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D061251:Primary Cell Culture; D020033:Protein Isoforms / Q000097:blood / Q000235:genetics / Q000276:immunology; D020317:Salmo salar / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015009:Yersinia Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D044124:Yersinia ruckeri / Q000276:immunology; D015027:Zebrafish / Q000235:genetics / Q000276:immunology / Q000382:microbiology
chemical_list: D029941:Fish Proteins; D053583:Interleukin-1beta; D053760:Interleukin-23 Subunit p19; D010457:Peptidoglycan; D020033:Protein Isoforms; D011070:Poly I-C
keywords: Atlantic salmon Salmo salar; Cloning; Expression; IL-23; Rainbow trout Oncorhynchus mykiss; p19