Identification of a cDNA encoding channel catfish interferon
Identification of a cDNA encoding channel catfish interferon
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DOI：
10.1016/s0145-305x(03)00122-8
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发表时间：
2004-02-01
影响因子：
2.9
通讯作者：
Chinchar, VG
中科院分区：
文献类型：
--
作者：
Long, S;Wilson, M;Chinchar, VG
尽管我们对硬骨鱼免疫的理解取得了相当大的进展，但在分子水平上已经确定的细胞因子基因，包括干扰素（IFN）基因，相对较少。相反，许多研究表明，在病毒感染或暴露于双链RNA后，鱼或鱼细胞产生一种功能类似于哺乳动物IFN的可溶性因子。通过BLASTX筛选从富含nk样细胞的混合淋巴细胞培养中产生的鲶鱼EST文库，鉴定了一个假定的鲶鱼（CF） IFN cDNA。与其作为假定的细胞因子cDNA的指定一致，3'非翻译区包含RNA不稳定基序的多个拷贝。对推导出的CF IFN氨基酸序列的分析显示，它与一组哺乳动物和鸟类IFN蛋白的相似性较低，而与最近发现的斑马鱼IFN蛋白的相似性明显较高。为了确定鉴定的cDNA是否编码CF IFN，在用紫外线灭活的鲶鱼呼肠孤病毒感染通道鲶鱼卵巢（CCO）细胞或暴露于双链RNA，诱导鲶鱼和其他物种的IFN或IFN样活性的处理后，监测其表达。在这两种情况下，检测到推测的CF IFN mRNA上调。此外，CIF IFN mRNA的上调伴随着培养基中抗病毒因子的出现。为了证实这些结果，我们在COS-7细胞中合成了重组CF IFN，并在CCO细胞中显示出抗病毒活性。总的来说，这些结果有力地证明了鉴定的鲶鱼cDNA是IFN同源物(C) 2003 Elsevier Ltd.。版权所有。
Despite considerable advances in our understanding of teleost immunity, relatively few cytokine genes, including those for interferon (IFN), have been identified at the molecular level. In contrast, numerous studies have shown that following virus infection or exposure to double-stranded RNA, fish or fish cells produce a soluble factor that is functionally similar to mammalian IFN. A putative catfish (CF) IFN cDNA was identified by BLASTX screening of a catfish EST library generated from a mixed lymphocyte culture enriched for NK-like cells. Consistent with its designation as a putative cytokine cDNA, the 3' non-translated region contained multiple copies of an RNA instability motif. Analysis of the deduced amino acid sequence of CF IFN showed low levels of identity/similarity to a panel of mammalian and avian IFN proteins, and markedly higher similarity to a recently identified zebrafish IFN. To determine if the identified cDNA encoded CF IFN, expression was monitored following infection of channel catfish ovary (CCO) cells with UV-inactivated catfish reovirus or exposure to double-stranded RNA, treatments which induce IFN or IFN-like activity in catfish and other species. In both cases, upregulation of putative CF IFN mRNA was detected. Moreover, upregulation of CIF IFN mRNA was accompanied by the appearance of an antiviral factor in the culture medium. To confirm these results, recombinant CF IFN was synthesized in COS-7 cells and shown to have antiviral activity in CCO cells. Collectively, these results argue strongly that the identified catfish cDNA is an IFN homolog (C) 2003 Elsevier Ltd. All rights reserved.