[Cloning and expression analysis of two pro-inflammatory cytokines, IL-1β and its receptor, IL-1R2, in the Asian swamp eel Monopterus albus].
Interleukin-1β (IL-1β) is the prototypic pro-inflammatory cytokine, whose functions are mediated through interaction with its receptors (IL-1R1 and IL-1R2). Herein, we cloned the full-length cDNA and genomic DNA of IL-1β and IL-1R2 in the Asian swamp eel (Monopterus albus). The eel IL-1β cDNA encodes a putative polypeptide of 246 amino acids. The protein sequence includes a typical IL-1 family signature, but lacked an interleukin-converting enzyme cleavage site. The genomic DNA of eel IL-1β was 2520 bp and comprised five exons and four introns. The eel IL-1R2 cDNA encoded a putative propeptide of 423 amino acid residues, comprising a signal peptide, a transmembrane region and two Ig-like domains in the extracellular region. Similar to other vertebrates, the genomic DNA of the eel IL-1R2 has nine exons and eight introns. Real-time PCR analysis indicated that IL-1β and IL-1R2 were constitutively expressed in all tissues, especially in the liver and immune-related organs. After infection with Aeromonas hydrophila, the transcript levels of IL-1β and IL-1R2 were induced in the head kidney and spleen, reaching their highest levels at 6 h post injection. In vitro, IL-1β and IL-1R2 mRNA levels were also upregulated rapidly at 1h post infection with A. hydrophila. Furthermore, acanthocephalan Pallisentis (Neosentis) celatus could induce the expression of both genes in the head kidney and intestine. In infected intestines, the transcript levels of IL-1β and IL-1R2 were increased by 21.4-fold and 20.8-fold, respectively, relative to the control. The present study indicated that IL-1β and IL-1R2 play an important role in inflammation and host defense, especially in the antiacanthocephalan response.
Engineering Research Center of Ecology and Agricultural, Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, Hubei Province, 434020 China.|School of Animal Science, Yangtze University, Jingzhou, Hubei Province, 434020 China.
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Xu
School of Animal Science, Yangtze University, Jingzhou, Hubei Province, 434020 China.
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Xu
School of Animal Science, Yangtze University, Jingzhou, Hubei Province, 434020 China.
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JW
Zhou
Fisheries Institute, Anhui Academy of Agricultural Sciences, Hefei, Anhui Province, 230031 China.
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Pan
School of Animal Science, Yangtze University, Jingzhou, Hubei Province, 434020 China.
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R
Tuo
School of Animal Science, Yangtze University, Jingzhou, Hubei Province, 434020 China.
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Ai
Engineering Research Center of Ecology and Agricultural, Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, Hubei Province, 434020 China.|Hubei Collaborative Innovation Center for Freshwater Aquaculture, Wuhan, 430070 China.|yangdaiqin319@163.com.
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Yang
D000818:Animals; D003001:Cloning, Molecular; D029941:Fish Proteins / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology*; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000235:genetics; D009928:Organ Specificity / Q000502:physiology; D053574:Receptors, Interleukin-1 Type II / Q000096:biosynthesis / Q000235:genetics; D023701:Smegmamorpha / Q000235:genetics / Q000378:metabolism
D029941:Fish Proteins; D053583:Interleukin-1beta; D053574:Receptors, Interleukin-1 Type II
Asian swamp eel; IL-1β; IL1 receptor 2; Monopterus albus; gene structure; inducible expression; interleukin-1β