HCMV潜伏相关UL138基因重组腺病毒的构建及其对THP-1单核细胞功能的影响

Constructing a recombinant adenovirus carrying human cytomegalovirus UL138 gene and evaluating the effects of UL138 gene on the functions of monocytes

目的：构建含人巨细胞病毒（ HCMV）潜伏相关 UL138基因的重组腺病毒,探讨UL138基因对THP-1单核细胞功能的影响。方法构建携带UL138基因的重组腺病毒,利用TCID50法确定重组腺病毒滴度。重组腺病毒以不同MOI比值感染THP-1细胞,通过绿色荧光蛋白表达确定感染THP-1细胞最佳MOI值；定量PCR分析UL138表达对THP-1细胞前炎症细胞因子表达变化,通过定量PCR芯片分析趋化因子及受体的表达变化。结果成功构建了携带UL138基因的重组腺病毒,TCID50法测定病毒的滴度达1x1011 PFU/ml。利用重组腺病毒携带的绿色荧光蛋白表达检测THP-1细胞的感染率,结果显示,重组腺病毒以MOI=1∶100感染THP-1细胞,感染率为60%, RT-PCR和Western blot证实了THP-1细胞能够表达UL138,且随着时间的延长,蛋白表达量逐渐增多。定量PCR检测发现,THP-1细胞 UL138过表达后,可明显抑制IL-18、IL-1β、IL-6、IL-8、TNF-α等前炎性细胞因子的表达。定量PCR芯片分析显示,UL138表达明显改变THP-1单核细胞内趋化因子及受体的表达,除外 CCL17、CCL21、CCL22、XCL2等趋化因子以及 CCR2、CXCR1、CXCR2、 CXCR4及CX3CR1等趋化因子受体在不同时间点上调表达外, CXCL1、CXCL3、CXCL9、CXCL10、CXCL11等大部分趋化因子及受体的表达均显著减少。结论成功构建了可感染THP-1单核细胞的UL138基因重组腺病毒；THP-1单核细胞过表达UL138可明显影响其功能。

Objective To construct a recombinant adenovirus carrying UL138 gene, which was re-lated to the latent infection of human cytomegalovirus, and to investigate the effects of UL138 gene on the functions of THP-1 mononuclear cells. Methods The recombinant adenovirus expressing the UL138 gene was packaged. The titer of the recombinant adenovirus was determined by calculating 50% tissue culture in-fective dose （ TCID50 ） . THP-1 mononuclear cells were infected with the recombinant adenovirus at different multiplicity of infection （MOI） and the optimal MOI was determined （100 PFU/cell） by observing the ex-pression of green fluorescent protein （ GFP ） . Changes in the expression of proinflammatory cytokines by THP-1 mononuclear cells that was induced by overexpressed UL138 were analyzed by quantitative PCR. Theexpression of chemokines and their receptors were measured by quantitative PCR array. Results The re-combinant adenovirus carrying the UL138 gene was successfully constructed with a titer of 1x10^11 PFU/ml. The rate of THP-1 mononuclear cells that was infected with the recombinant adenovirus was 60% at the MOI of 1 ∶ 100. Results of the RT-PCR analysis and Western blot assay further confirmed that the recombinant adenovirus could infect THP-1 mononuclear cells successfully and the expression of UL138 protein increased gradually over time. The overexpressed UL138 in THP-1 mononuclear cells significantly inhibited the expres-sion of IL-18, IL-1β, IL-6, IL-8 and TNF-α as indicated by the results of quantitative PCR. Results ob-tained from the quantitative PCR array analysis showed that most of the chemokines and their receptors were downregulated in the transfected THP-1 mononuclear cells except for the chemokines of CCL17, CCL21, CCL2 and XCL2 and the receptors of CCR2, CXCR1, CXCR2, CXCR4 and CX3CR1 which were upregulat-ed. Conclusion We successfully constructed the recombinant adenovirus carrying UL138 gene which could be used to infect THP-1 mononuclear cells. Overexpressed UL138 in THP-1 mononuclear cells significantly affected the functions of THP-1 mononuclear cells.