人巨细胞病毒UL148基因在临床低传代分离株中的多态性研究

目的 研究人巨细胞病毒(HCMV)UL148序列在临床低传代分离株中的多态性。方法 对38株经荧光定量PCR方法(Q-PCR)检测HCMV-DNA为阳性的临床低传代分离株的细胞培养上清液进行HCMV UL148全序列PCR扩增，并对PCR扩增产物进行序列测定及分析。结果 38株临床低传代分离株有17株PCR扩增阳性，与HCMV Toledo株进行序列比较分析，17株临床分离株ULl48开放阅读框架(ORF)长度均与Toledo株相同。其编码蛋白的氨基酸变异率为0．3％～2．3％。所有分离株均有蛋白翻译后修饰位点的新增或缺失。与Toledo株相比17株临床分离株UL148蛋白质二级结构预测结果均为第15～18位之间由α-螺旋变为β-折叠。结论 17株HCMV临床低传代分离株UL148基因及其编码产物的氨基酸序列比较保守，但仍存在一定程度的多态性。

Polymorphism analysis of human cytomegalovirus UL148 gene in low passage clinical isolates

BACKGROUND: To investigate the polymorphism of human cytomegalovirus UL148 gene in low passage clinical isolates and to study the relationship between the polymorphism and different pathogenesis of congenital HCMV infection. METHODS: PCR was performed to amplify the entire HCMV UL148 gene region of 38 clinical isolates, which had been proven containing detectable HCMV-DNA by using FQ-PCR.PCR amplification products were sequenced directly and the sequence data were analysed. RESULTS: Seventeen of 38 isolates were amplified successfully. By comparison with Toledo sequence, the length of UL148 ORFs in all 17 clinical isolates was similar to that of Toledo.Amino acid variability rate of UL148 protein was 0.3%-2.3%. There were additional or deleted sites of posttranslational modification of UL148 protein in all clinical isolates. CONCLUSION: All DNA and deduced amino acid sequences of UL148 gene shared great similarity among HCMV clinical strains regardless of their polymorphism.