巨细胞病毒感染的细胞微丝骨架重组异常

Impaired Microfilament Cytoskeletal Rearrangement in Cytome-galovirus Infected Cells

本研究探讨巨细胞病毒(CMV)感染对人胚成纤维细胞(HF)微丝骨架影响及与病毒复制状态的可能关系。用显微镜观察细胞形态,采用RT-PCR检测β-actin表达,Western-blot检测胞内肌动蛋白质含量,间接免疫荧光标记病毒即刻早期抗原(IE)与微丝骨架探针观察HF细胞内感染状况及微丝骨架变化。结果表明CMV感染率大于95%,IE抗原主要位于胞核。受染细胞变粗、变圆,甚至脱壁,呈时间依赖性。感染后72、96小时,受染细胞内β-actin表达呈渐进性下调,差异显著(P<0.05);96小时后胞内β-actin含量则为未感染组的(74.2±13.4)%,差异显著(P<0.05)。受染细胞内微丝排列紊乱,极性消失;细胞融合,荧光强度明显减弱。结论CMV引起细胞内肌动蛋白质、微丝骨架形态及重组异常可能有助于其侵袭宿主细胞并进一步活化及复制。

The objective of this study was to investigate the effect of cytomegalovirus （CMV） infection on actin and microfilament in human embryo fibroblast cells（HF） and to explore the possible relationship with CMV replication. The cell shape was observed by microscopy after the infection of CMV, RT-PCR assay was used to detect the mRNA expression of β-actin gene, while Westen-blot was used to measure the level of β-actin protein. CMV immediately early antigen （IE） in HF cells was analyzed by indirect immunofluorescence assay. Microfilament alteration was determined by cytoskeleton fluorescence probe. The results showed that CMV IE was observed in more than 95% of HF cells after infection, primarily located in nucleus. HF cells infected by CMV changed from thin shuttle shape to round and thick ball shape, even detached from wall. β-actin got a significant and gradual decreasing of mRNA level in time-dependent manner （ P 〈 0.05 ）. Compared with uninfected group, the expression of β-actin protein decreased to （ 74.2 ＋ β.4） % at 96 hours after infection （ P 〈 0.05 ）. In infected HF cells, microfilaments were ruptured, arranged turbulently, as well as cells merged and fluorescence density of microfilament obviously reduced. It is concluded that cytomegalovirus can induce alteration of actin and microfilament, which may be helpful for CMV to infect, replicate and reactivate in host cells.