人巨细胞病毒临床分离株US28基因的研究

目的 研究US28基因在儿童人巨细胞病毒临床分离株中的多态性，探讨多态性与致病性间的关系。方法 对临床分离株进行PCR扩增和HMA—SSCP分析，选取有代表性的毒株进行克隆和测序，对测序结果进行序列分析。结果 测序结果可见US28核酸变异比较普遍，变异集中在序列的两端，大部分变异是同义突变，US28的重要功能基团高度保守；氨基酸变异使临床株的US28编码蛋白的二级结构呈现出3种新构象；未发现US28基因多态性与临床致病性的联系；GenBank序列与临床分离株序列的氨基酸高突变位点不尽相同。结论 US28基因变异在临床分离株中普遍存在，临床株序列与GenBank序列在氨基酸的高突变位点上存在差异；实验室标准株VHL／E株比AD169株和TOWNE株更接近临床株。

Polymorphisms of HCMV US28 gene of the clinical isolates from children

Objective To study the polymorphism of human cytomegalovirus US28 gene in children and investigate the relationship between the polymorphism and pathogenesis. Methods The FQ-PCR was carried out to determine the DNA quantity of clinical isolate and then the segmental PCR and HMA-SSCP were performed to test the mutation of US28 gene. The typical isolates from different diseases were selected to clone and sequence, then the results were analyzed. Results The nucleic acid mutation is frequent among the sequence of US28, those mutations focus on the two ends of US28, but most of them are sense mutation. The important functional groups of US28 are highly conserved. The amino acid mutation of some isolates resulted in the change of secondary structure, but the phylogenetic tree analysis did not show any clear association between the pathogenesis and the distribution of clinical isolates. The comparison of US28 sequences from AIDS patients with the sequences from children in our study showed that both sequences have their own specific high mutation points. Conclusion There is polymorphism among the HCMV US28 gene of clinical isolates from children. There observed no clear relationship was between the Pathogenesis and the distribution of clinical isolates.