Animals (Nov 2023)

Molecular and Functional Characterization of α Chain of Interleukin-15 Receptor (<i>IL-15Rα</i>) in Orange-Spotted Grouper (<i>Epinephelus coioides</i>) in Response to <i>Vibrio harveyi</i> Challenge

  • Yilin Zhang,
  • Fan Wu,
  • Guanjian Yang,
  • Jichang Jian,
  • Yishan Lu,
  • Zhiwen Wang

DOI
https://doi.org/10.3390/ani13233641
Journal volume & issue
Vol. 13, no. 23
p. 3641

Abstract

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Interleukin-15 (IL15) is a proinflammatory cytokine that could induce the production of inflammatory cytokines. In this study, the α chain of the IL15 receptor of Epinephelus coioides (Ec-IL15Rα), a natural regulator of IL15, was identified, and immune response functions of fish were determined and characterized. Ec-IL15Rα contains a 720 bp open reading frame that encodes 239 amino acids, including four typical conserved cysteine residues with a highly conserved sushi domain. Ec-IL15Rα is closely related to Epinephelus lanceolatus and is the most clustered with teleost. Subcellular localization studies showed that Ec-IL15Rα was situated in the cytoplasm and cell membrane. Ec-IL15Rα was detected in 11 tissues, with the highest expression in the liver and blood. Meanwhile, the Ec-IL15Rα transcriptional levels substantially increased in nine tissues after Vibrio harveyi infection. Ec-IL15Rα was significantly up-regulated in HKLs by ConA, PHA, LPS and poly I:C stimulation. In vitro analysis, the recombinant protein of rEc-IL15Rα stimulates HKL proliferation and IL1R, IL6R, IL10, and IL16 expression. Challenge experiments revealed that IL15Rα protein showed an increase of 6.67–10% survival protection rate after V. harveyi infection. This study provides a better understanding of the immune protection of IL15Rα in vertebrate fish.

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