人巨细胞病毒UL144基因多态性与婴儿肝炎  

Polymorphism of human cytomegalovirus UL144 gene and infant hepatitis

作　　者：叶万定 温正旺[1] 章虎[1] 陈益平[1] Ye Wanding;Wen Zhengwang;Zhang Hu;Chen Yiping(Department of Pediatric Infectious Disease,the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University,Wenzhou 325000,Zhejiang,China)

机构地区：[1]温州医科大学附属第二医院儿童感染科,浙江温州325000

出　　处：《国际流行病学传染病学杂志》2018年第6期423-427,共5页International Journal of Epidemiology and Infectious Disease

基　　金：温州市科学技术局公益性科技项目(Y20160018).

摘　　要：目的了解人巨细胞病毒(HCMV)UL144基因在婴儿HCMV肝炎中的多态性及序列特点。方法收集2017年1-6月温州医科大学附属第二医院24例HCMV肝炎患儿的尿液,通过离心获取尿沉渣,提取HCMV DNA;采用PCR扩增DNA提取物UL144基因开放读码框(ORF),并进行荧光电泳检测;扩增阳性样本进行DNA测序及分析。结果24例HCMV肝炎患儿尿沉渣中,11例扩增阳性(其中样本IH6氨基酸编码提前终止),UL144基因检出率为45.8%。种系进化树分析显示,10例阳性样本(除外IH6)DNA序列分为3个基因型为A型(1例),B型(8例),C型(1例)。将所测得的UL144序列及Toledo株进行同源性比较,核苷酸同源性为56.8%~100%,氨基酸同源性为48.2%~100%;与Toledo株比较,A型和C型氨基酸序列变异性小,同源性分别为98.2%和82.9%;而B型变异性大,同源性为48.8%~49.4%。EXPASY数据库分析功能位点显示,除ZF-CTCHY和Prokar_Lipoprotein仅存在于UL144 B型外,其他功能位点均存在于三种基因型中;其中N-glycosylation、TN-FR_NGFR_1、CRD、TNFR_C6、NCD3G呈高度保守性。结论婴儿HCMV肝炎UL144基因存在A、B、C3个基因型,以B型为主;A型和C型较为保守,而B型存在显著变异性。UL144基因所编码蛋白的重要功能位点具有高度保守性。Objective To investigate the polymorphism and sequence characteristics of human cytomegalovirus (HCMV) UL144 gene in infants with HCMV hepatitis.Methods From January to June 2017, 24 infants with HCMV hepatitis were recruited in Second Affiliated Hospital of Wenzhou Medical University. Urine samples were collected to obtain urine sediments by centrifugation, and then DNA was extracted. The UL144 gene open reading frame (ORF) was amplified by polymerase chain reaction (PCR) in DNA extractives and detected by fluorescence electrophoresis. Positive results were determined by DNA sequencing.Results Out of 24 urine samples from infants with HCMV hepatitis, UL144 were successfully amplified and sequenced by PCR in 11 patients (The amino acid encoding of the specimen IH6 terminated prematurely) , the positive detection rate was 45.8%. Phylogenetic tree analysis showed that DNA sequences of the 10 positive specimens (except for IH6) were divided into 3 genotypes including type A (1 case) , type B (8 cases) and type C (1 case) . Homology comparison between UL144 gene sequences and Toledo strains revealed that the nucleotide homology ranged from 56.8% to 100%, and amino acid homology ranged from 48.2% to 100%. Compared with Toledo strains, amino acid sequences of genotype A and genotype C had less variability, of which the homology were 98.2% and 82.9%, respectively. However, genotype B had more variability, of which the homology was from 48.8% to 49.4%. Then functional motifs analyzed by EXPASY showed that except that ZF-CTCHY and Prokar_Lipoprotein existed only in UL144 B type, all other functional loci existed in three genotypes. Among them, N-glycosylation, TNFR_NGFR_1, CRD, TNFR_C6 and NCD3G were highly conservative.Conclusions There are three UL144 genotypes in infants with cytomegalovirus hepatitis, including A, B and C. Genotype B is the main type. Type A and C are conservative, while type B is obviously variable. Important functional motifs encoded by UL144 are highly conserved.

关 键 词：巨细胞病毒 肝炎 种系进化 核苷酸 同源性 婴儿 

分 类 号：R725.7[医药卫生—儿科]