Transforming growth factor-β1b: a second TGF-β1 paralogue in the rainbow trout (Oncorhynchus mykiss) that has a lower constitutive expression but is more responsive to immune stimulation
| Autor: | Maria M. Costa, Jose L. González Vecino, Tanja Maehr, Tiehui Wang, Christopher J. Secombes, Simon Wadsworth, Samuel A.M. Martin |
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| Přispěvatelé: | Marine Alliance for Science and Technology for Scotland |
| Rok vydání: | 2012 |
| Předmět: |
TGF-β
Lipopolysaccharides LPS Macrophage Molecular Sequence Data Aquatic Science Novirhabdovirus Transforming Growth Factor beta1 Exon Fish Diseases Species Specificity Rhabdoviridae Infections Environmental Chemistry Animals Gene Integrin binding Genetics biology Base Sequence VHSV Pathogen-associated molecular pattern Gene Expression Profiling Intron Gene Expression Regulation Developmental General Medicine Sequence Analysis DNA biology.organism_classification Head Kidney Molecular biology Gene expression profiling Trout Rainbow trout Gene Components Poly I-C Oncorhynchus mykiss Cytokines Mitogens |
| Zdroj: | Fishshellfish immunology. 34(2) |
| ISSN: | 1095-9947 |
| Popis: | 13 pages, 9 figures, 2 tables The rainbow trout (Oncorhynchus mykiss) TGF-β1 sequence was one of the first fish cytokines described. Studies of its expression suggest it is constitutively expressed but displays refractory inducibility. Here we describe a second TGF-β1 (TGF-β1b) gene that is novel in several respects. TGF-β1b possesses typical TGF-β features, including a CXC motif and an integrin binding site, a tetrabasic cut site and a mature peptide of 112 amino acids (aa) containing nine conserved cysteine residues. The mature peptide is 83% identical to the first TGF-β1 sequence described in rainbow trout, that we designate TGF-β1a, and relative to TGF-β1a shows higher homology to Atlantic salmon TGF-β1b, zebrafish TGF-β1a, and sea bass and seabream TGF-β1. The gene organisation of salmonid TGF-β1b genes, as inferred from Atlantic salmon whole genome shotgun contigs, is a 6 exon/5 intron structure with exons 3 and 4 of salmonid TGF-β1a genes apparently fused together. The two trout TGF-β1 genes have a wide distribution in vivo, with highest expression found in immune tissues for both isoforms indicating that TGF-β1 has a predominant role in immunity of fish. Expression of both genes was also seen during the ontogeny of trout, with TGF-β1a relatively constant in expression level but TGF-β1b increasing over time. Immune responses in head kidney (HK) macrophages induced by pathogen associated molecular patterns (PAMPs), pro-inflammatory cytokines, mitogens and pathway activators highly elevated the expression level of TGF-β1b but not that of TGF-β1a. TGF-β1b expression was also increased by polyinosinic:polycytidylic acid (poly(I:C)) and/or lipopolysaccharide (LPS) stimulation in three different trout cell lines studied. Finally we show that TGF-β1b is potentially involved in defense against infection with viral haemorrhagic septicemia virus (VHSV), which had no effect on TGF-β1a expression. Thus, it is likely the TGF-β1b gene represents a copy which fulfils the major immune orchestrating functions of TGF-β1 as seen in other vertebrates. TW received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). |
| Databáze: | OpenAIRE |
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