人巨细胞病毒感染对人胚肺成纤维细胞复制允许因子Cdt1表达的影响

Influence of human cytomegalovirus infection on replication licensing factor Cdt1 in human embryonic lung fibroblast

目的研究人巨细胞病毒（human cytomegalovirus，HCMV）感染对人胚肺成纤维细胞（human embryonic lung fibroblast，HELF）复制允许因子Cdt1表达的影响，探讨HCMV感染的发病机制。方法以HCMV感染同步化的HELF作为感染组，同时设模拟感染组为对照组。采用半定量逆转录聚合酶链反应（RT-PCR）法检测Cdt1 mRNA的表达水平。结果模拟感染组在感染后12h时Cdt1 mRNA表达水平最高，后逐渐下降，至72h时达最低水平，96h时又稍回升。感染组在感染后12h时Cdt1 mRNA表达水平较低，24h时稍升高，48h达最高峰，48h后至72h急剧下降，96h时大致维持72h时水平。两组相比，12h、24h和48h时Cdt1 mRNA表达水平差异有显著性（P为0．001～0．030），12h和24h时感染组较模拟感染组明显降低，48h时感染组较模拟感染组明显升高。模拟感染组Cdt1 mRNA表达水平的高峰出现在感染后12h，而感染组的高峰则出现在感染后48h，较之明显滞后。结论HCMV感染使HELF复制允许因子Cdt1 mRNA的表达水平迟滞。

Objective To study the expression level of replication licensing factor Cdt1 after human cytomegalovirus （HCMV） infected human embryonic lung fibroblast （HELF）, and explore the pathogenesis of HCMV infection. Methods Synchronized HELF were infected with HCMV, the simulant-infected group was set up as control group, the expression level of Cdt1 mRNA in HELF was determined by reverse transcription-ploymerase chain reaction （RT-PCR）. Results In the simulant-infected group, the expression level of Cdt1 gene reached a peak at 12 hours of post-infection, then decreased gradually, and reached a nadir at 72 hours of post-infection, but then returned a little at 96 hours of post-infection, while in the infected group, the expression level of Cdt1 gene was low at 12 hours of post-infection, then increased slightly at 24 hours of post-infection, and reached a peak at 48 hours of post-infection, and then decreased sharply from 48 to 72 hours of post-infection, and at 96 hours of post-infection maintained the same levels as at 72 hours of post-infection. The statistical analysis showed the expression level of Cdt1 gene in HCMV-infected group was significantly lower （P〈0. 05） than that in the simulant-infected group at 12 and 24 hours of post-infection, but significantly higher at 48 hours of post-infection. The expression level of Cdt1 gene reached a peak at 12 hours of post-infection in the simulant-infected group, but in HCMV-infected group, reached a peak at 48 hours of post-infection, which markedly lagged behind the one in the simulant-infected group. Conclusion HCMV infection has an effect on the expression level of replication licensing gene Cdt1, and makes the expression lag behind.