Abstract: The Microplitis bicoloratus bracovirus (MbBV) is one type of polydnavirus, which is mainly found in parasitic wasps (Hymenoptera: Braconidae) and plays a vital role in parasitism. Cyclophilin A (CypA) is a peptidyl-prolyl cis-trans isomerase involved in several different cellular events including the immune response. During the process of insect cells infected by MbBV, whether there was any relationship between MbBV and the level of CypA was mainly investigated. The results showed that the MbBV gene can be detected in Hi5 insect cells after 24 h of infection with MbBV, during which the transcriptional level and protein expression level of cypa were both upregulated. When CypA was silenced or suppressed in MbBV-treated Hi5 cells, vank86, a gene encoding one member of MbBV, was remarkably down-regulated via analysis of qRT-PCR. And overexpression of CypA in Hi5 cells leaded to an upregulation of the vank86. These results indicated that the level of CypA in insect cells might be correlated to the MbBV infection.

Key words: MbBV, cyclophilin A, viral infection, Hi5 cells

摘要： 茧蜂病毒（Microplitis bicoloratus bracovirus，MbBV）属于多分DNA病毒（polydnavirus，PDV）的一种，主要存在于膜翅目茧蜂科寄生蜂中，对于寄生蜂成功寄生宿主起着至关重要的作用。而亲环素A（cyclophilin A，CypA）是一种肽基脯氨酰顺反异构酶，参与免疫反应等多种细胞活动。主要探讨了茧蜂病毒在感染昆虫细胞的过程中，是否与CypA存在相关性。研究结果显示，在粉纹夜蛾(Trichoplusia ni Hübner)卵细胞系（High Five，Hi5）培养基中加入茧蜂病毒24 h后，通过PCR可扩增出与病毒基因大小一致的目的片段，表明Hi5细胞已被茧蜂病毒感染。在病毒感染细胞后，CypA的基因转录水平显著升高，其蛋白表达水平也有所增加；当沉默cypa基因或抑制CypA活性后，实时荧光定量PCR（real-time fluorescence quantitative PCR，qRT-PCR）结果显示，茧蜂病毒基因中的vank86基因转录水平显著下降；而过表达cypa基因，可使vank86基因转录水平上升。研究结果提示，茧蜂病毒在感染昆虫细胞的过程中，可能与CypA存在一定的相关性。

关键词: 茧蜂病毒, 亲环素A, 病毒感染, Hi5细胞