Cloning of a novel interleukin (IL)-20-like gene in rainbow trout Oncorhynchus mykiss gives an insight into the evolution of the IL-10 family

Tiehui Wang, Patricia Díaz-Rosales, Sam A M Martin, Christopher J. Secombes*, Samuel Allen Moore Martin

*Corresponding author for this work

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

A novel IL-20-like (IL-20L) gene has been analyzed in rainbow trout. It has a six exon/five intron gene organisation and is translated into 181 amino acids (aa) with a signal peptide of 25aa and a mature peptide of 156aa. The trout IL-20L translation shares highest identities to other IL-20L molecules from fish and to IL-20 in mammals. Phylogenetic analysis showed that the fish IL-20L molecules form an independent clade but cluster with the group containing the IL-19, IL-20 and IL-24 molecules from higher vertebrates with a high bootstrap value (89%). The fish IL-20L genes are syntenically in the same location as mammalian IL-19/IL-20/IL-24. Gene organisation and multiple alignment also showed a close relationship of fish IL-20L genes to the mammalian IL-19/IL-20/IL-24 subfamily. These data suggest that the fish IL-20L molecules may have arisen from an ancestral gene that gave rise to IL-19, IL-20 and IL-24 in higher vertebrates. A high level of IL-20L expression in immune related tissues and in the brain, suggests an important role of the fish IL-20L molecule in both the fish immune system and nervous system. Although the exact cell types expressing IL-20L have yet to be defined, macrophages express IL-20L. Moreover, the IL-20L expression in the macrophage cell line RTS-11 was modulated by pro-inflammatory cytokines, signalling pathway activators, microbial mimics and the immuno-suppressor dexamethasone. These data suggest that trout IL-20L is an important player in the cytokine network. The increased expression of IL-20L was only detected at late stages (4-24h) of LPS stimulation in RTS-11 cells and in spleen 24-72h after infection with Yersinia ruckeri, and suggests that the increased expression of IL-20L by LPS and infection may be via the rapid increase of pro-inflammatory cytokines (e.g., IL-1beta) and other factors that is known to occur.
Original languageEnglish
Pages (from-to)158-167
Number of pages10
JournalDevelopmental and Comparative Immunology
Volume34
Issue number2
DOIs
Publication statusPublished - 1 Feb 2010

Keywords

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Cloning, Molecular
  • Evolution, Molecular
  • Fish Proteins
  • Gene Expression Regulation
  • Humans
  • Interleukin-10
  • Interleukins
  • Molecular Sequence Data
  • Oncorhynchus mykiss
  • Phylogeny
  • Yersinia Infections
  • Rainbow trout
  • IL-20L
  • IL-10 family
  • Gene organisation
  • Bacterial infection
  • Interferon-gamma
  • IL-1beta
  • Expression
  • Modulation
  • Expression Analysis
  • Yersinis-Ruckeri
  • Host-Defense
  • IFN-Gamma
  • Cytokine
  • Identification
  • Fish
  • Receptors
  • Cell
  • Discovery

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