人巨细胞病毒UL134基因在临床低传代分离株的多态性研究

Polymorphism of human cytomegalovirus UL134 gene in low-passage clinical isolates

目的人巨细胞病毒（HCMV）呈现一定的基因多态性。病毒的致病性可能与不同分离株的基因变化有关。HCMV Toledo株和其他低传代临床分离株基因组UL／b’区中发现的19个基因（UL133-UL151）可能在病毒潜伏、复制、逃避机体免疫和不同组织细胞嗜性等方面起重要作用。该文研究HCMV不同临床分离株UL134基因及其编码蛋白氨基酸序列的多态性，分析这种多态性与人巨细胞病毒感染引起的各种疾病之间的关系，提供了HCMV基因多态性的一项基本数据。方法对荧光定量PCR方法检测HCMV-DNA阳性的32株临床低传代分离株进行UL134基因全序列PCR扩增、测序及分析。结果32株临床低传代分离株UL134基因PCR扩增均阳性。与Toledo株比较，临床分离株UL134基因核苷酸和预测编码蛋白质的氨基酸序列较保守，同源性分别为96．4％-98．3％和92．7％-94．9％，但预测编码蛋白质新增一个SUL位点。结论与Toledo株比较，临床分离株UL134基因比较保守，但仍具有一定的多态性，未发现UL134基因与HCMV致病性之间的本质联系。

Objective Human cytomegalovirus （HCMV） displays genetic polymorphisms. Nineteen open reading frames （ORFs, UL133-UL151 ） found in the Toledo strain of HCMV and other low-passage clinical isolates may be essential for viral infection. This study aimed to analyze the polymorphism of HCMV UL134 gene in clinical isolates and explore the relationship between the polymorphism and HCMV infection. Methods PCR was performed to amplify entire UL134 region in 32 clinical isolates, which had been proven as HCMV-DNA positive by FQ-PCR. PCR products were sequenced. Results All of the 32 isolates were amplified and sequenced successfully. HCMV UL134 gene was highly conserved in the clinical isolates. UL134 ORF and its predicted protein in the clinical strains displayed 96.4% - 98.3% nucleotide identity and 92.7% - 94.9% amino acid identity respectively compared to those in the Toledo strain. A new posttranslational modification site, sulfationcamp （SUL） site, was found in UL134 protein of all of the clinical isolates except 35j. Conclusions HCMV ULI34 gene in clinical isolates was highly conserved. No substantial relation was found between UL134 gene and HCMV infectious diseases.