Robertsen Børre
Department of Marine Biotechnology, Norwegian College of Fishery Science, University of Tromsø, 9037 Tromso, Norway.
Fish Shellfish Immunol. 2006 Feb;20(2):172-91. doi: 10.1016/j.fsi.2005.01.010.
Interferons (IFNs) are secreted proteins, which induce vertebrate cells into an antiviral state. In mammals, three families of IFNs (type I IFN, type II IFN and IFN-lambda) can be distinguished on the basis of gene structure, protein structure and functional properties. Type I IFNs, which include IFN-alpha and IFN-beta, are encoded by intron lacking genes and have a major role in the first line of defense against viruses. The human IFN-lambdas have similar biological properties as type I IFNs, but are encoded by intron containing genes. Type II IFN is identical to IFN-gamma, which is produced by T helper 1 cells in response to mitogens and antigens and has a key role in adaptive cell mediated immunity. IFNs, which show structural and functional properties similar to mammalian type I IFNs, have recently been cloned from Atlantic salmon, channel catfish, pufferfish, and zebrafish. Teleost fish appear to have at least two type I IFN genes. Phylogenetic sequence analysis shows that the fish type I IFNs form a group separated from the avian type I IFNs and the mammalian IFN-alpha, -beta and -lambda groups. Interestingly, the fish IFNs possess the same exon/intron structure as the IFN-lambdas, but show most sequence similarity to IFN-alpha. Recently, IFN-gamma genes have also been cloned from several fish species and shown to have the same exon/intron structure as mammalian IFN-gamma genes. The antiviral effect of mammalian type I IFN is exerted through binding to the IFN-alpha/beta-receptor, which triggers signal transduction through the JAK-STAT signal transduction pathway resulting in expression of Mx and other antiviral proteins. Putative IFN receptor genes have been identified in pufferfish. Several interferon regulatory factors and members of the JAK-STAT pathway have also been identified in various fish species. Moreover, Mx and several other interferon stimulated genes have been cloned and studied in fish. Furthermore, antiviral activity of Mx protein from Atlantic salmon and Japanese flounder has recently been demonstrated.
干扰素（IFNs）是分泌蛋白，可诱导脊椎动物细胞进入抗病毒状态。在哺乳动物中，可根据基因结构、蛋白质结构和功能特性区分出三类干扰素（I型干扰素、II型干扰素和λ干扰素）。I型干扰素包括α干扰素和β干扰素，由无内含子的基因编码，在抵御病毒的第一道防线中起主要作用。人类λ干扰素具有与I型干扰素相似的生物学特性，但由含内含子的基因编码。II型干扰素等同于γ干扰素，由辅助性T1细胞在有丝分裂原和抗原刺激下产生，在适应性细胞介导免疫中起关键作用。最近，已从大西洋鲑鱼、斑点叉尾鮰、河豚和斑马鱼中克隆出结构和功能特性与哺乳动物I型干扰素相似的干扰素。硬骨鱼似乎至少有两个I型干扰素基因。系统发育序列分析表明，鱼类I型干扰素形成一个与禽类I型干扰素以及哺乳动物α、β和λ干扰素群体分开的类群。有趣的是，鱼类干扰素具有与λ干扰素相同的外显子/内含子结构，但与α干扰素的序列相似性最高。最近，也已从几种鱼类中克隆出γ干扰素基因，并表明其具有与哺乳动物γ干扰素基因相同的外显子/内含子结构。哺乳动物I型干扰素的抗病毒作用是通过与α/β干扰素受体结合来实现的，该受体通过JAK-STAT信号转导途径触发信号转导，从而导致Mx和其他抗病毒蛋白的表达。在河豚中已鉴定出假定的干扰素受体基因。在各种鱼类中还鉴定出了几种干扰素调节因子和JAK-STAT途径的成员。此外，已在鱼类中克隆并研究了Mx和其他几种干扰素刺激基因。此外，最近已证明大西洋鲑鱼和牙鲆的Mx蛋白具有抗病毒活性。
