鳜亲环蛋白A在传染性脾肾坏死病毒增殖中的作用

Effect of mandarin fish cyclophilin A on the multiplication of infectious spleen and kidney necrosis virus

为研究鳜亲环蛋白(CypA)在传染性脾肾坏死病毒(ISKNV)感染中的作用,通过RT-PCR克隆了CypA全长开放读码框(SC-CypA)。结果表明SC-CypA基因全长495 bp,编码164个氨基酸,分子量为17.59 ku。通过Blast比对和同源性进化分析,发现其与人、鼠、原鸡和斑点鲖等物种的CypA具有高度相似性,表明SC-CypA属于CypA家族的成员。环孢素A(CsA)具有免疫抑制作用,是CypA的抑制剂。结果发现,CsA浓度与ISKNV增殖具有一定的剂量依赖关系;CsA作用不同时间对ISKNV均有抑制效果;CsA对ISKNV感染诱导的细胞因子的表达具有调节作用,能抑制IL-1β、IL-8、IL-18和ISG15的表达。研究表明,宿主的CypA对ISKNV的增殖起着重要的作用,通过添加其抑制剂CsA能有效抑制病毒的增殖。

It has been shown that host protein cyclophilin A （CypA） played a key role in the replication of several viruses. In order to address the function of Mandarin fish CypA （SC-CypA） in infectious spleen and kidney necrosis virus （ISKNV） replication, the full ORF of SC-CypA was first cloned and characterized. The ORF of SC- CypA encoded a polypeptide of 164 amino acids with calculated molecular weight of 17.59 ku. The deduced amino acid sequences of the SC-CypA shared highly conserved structures with CypAs from other species, indicating that SC-CypA should be a new member of the CypA family. Cyclosporin A （CsA） is a specific inhibitor of CypA. ISKNV replication was inhibited by the addition of CsA in a manner of dose dependence. CsA could effectively inhibit the replication of ISKNV at different time points after ISKNV infection, and the strongest inhibitory effect was observed at 72 h poi. The addition of CsA could inhibit the mRNA expressions of IL- 1 β, IL-8, IL-18 and ISG15 in CPB cells after the infection of ISKNV. These suggest that SC-CypA plays a key role in the ISKNV replication, and CsA could effectively inhibit the replication of ISKNV.