The Atlantic salmon interleukin 4/13 receptor family: Structure, tissue distribution and modulation of gene expression

• Published in: Fish & Shellfish Immunology
• Main Authors: Sequeida, Alvaro, Castillo, Andrés, Cordero, Natalia, Wong, Valentina, Montero, Ruth, Vergara, Claudio, Valenzuela, Beatriz, Vargas, Deborah, Valdés, Natalia, Morales, Jonathan, Tello, Mario, Sandino, Ana María, Maisey, Kevin, Imarai, Mónica
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2019
• Subjects: article; Text; ddc:570; IL-4/13 receptors > In silico protein structure > IL-4/13A > Atlantic salmon; Atlantic salmon
• Online Access: https://doi.org/10.1016/j.fsi.2019.11.030; https://www.openagrar.de/receive/openagrar_mods_00052739; https://www.openagrar.de/servlets/MCRFileNodeServlet/openagrar_derivate_00027736/SD2019440_SD202091.pdf; https://www.sciencedirect.com/science/article/abs/pii/S1050464819310733

Interleukin (IL)-4 and IL-13 play a central role in T helper 2 immune response in mammals. The cell signalling is mediated by the type I heterodimeric receptor containing the IL-4Rα and γC chains, and the type II receptors formed by IL-4Rα and IL-13Rα1. In salmonid species, three paralogues of the IL-4 and IL-13 cytokines have been reported, il-4/13a, il-4/13b1 and il-4/13b2. In regard to receptors, two paralogues of each IL-4/13 receptor chains have been identified in rainbow trout while five genes named γc1, il-4rα, il-13rα1a, il-13rα1b, and il-13rα2 have identified in Atlantic salmon. Since Atlantic salmon is an important farmed fish species, the aim of this work was to get new insights into distribution, structure and expression regulation of the IL-4/13 receptors in salmon. By using qRT-PCR, it was shown that all γc1, il-4rα, il-13rα1a, il-13rα1b, and il-13rα2 receptor chains were expressed in lymphoid and non-lymphoid tissues of healthy salmon, nonetheless γC expression was higher in lymphoid than non-lymphoid tissues. The in silico structural analysis and homology modelling of the predicted receptor proteins showed that domains and most motifs present in the superior vertebrate chains are conserved in salmon suggesting a conserved role for these receptor chains. Only IL-13Rα1B is a receptor chain with a unique structure that seem not to be present in higher vertebrates but in fish species. In order to determine the regulatory role of IL-4/13 on the expression of receptor chains, Atlantic salmon il-4/13A gene was synthetized and cloned in pET15b. The recombinant IL-4/13A was produced in E. coli and the activity of the purified cytokine was confirmed in vitro. The regulatory role of IL-4/13A on the expression of their potential receptors was tested in salmon receiving the recombinant cytokine and effects were compared with those of the control group. The results showed that IL-4/13A induced the expression of its own gene and GATA-3, in the head kidney of fish but not in the spleen, while IL-10 increased in ...