一株引起严重急性呼吸道感染病例的A亚型人呼吸道合胞病毒全基因组基因特征分析

Whole-genome Sequence Analysis of Human Respiratory Syncytial Virus Subgroup A Associated with Severe Acute Respiratory Infection in China

人呼吸道合胞病毒(Human respiratory syncytial virus,HRSV)是导致儿童急性呼吸道感染的最重要的呼吸道病毒之一。根据对单克隆抗体的反应,HRSV分为A、B两个亚型。为探讨严重急性呼吸道感染(Severe acute respi-ratory infection,SARI)病例中HRSV全基因组基因特征,本研究对2017年河南省漯河市住院SARI病例中检测到的1株HRSV A亚型病毒通过Sanger测序方法对其全基因组序列进行了测定和分析。通过Sequencher 5.4.5、MEGA 5.05、BioEdit 7.0.5等生物信息学软件进行序列拼接和比对,进行了基因亲缘性关系分析、氨基酸变异和糖基化位点分析。基于HRSV全基因组序列和11个单个蛋白基因序列构建的亲缘性关系分析结果提示本研究中检测到的这株HRSVA病毒(RSVAs/Luohe.Henan/CHN/42.17)属于ON1基因型,该型是我国近年流行的优势基因型。该病毒全基因组序列与35条全球代表株的核苷酸和氨基酸同源性分别为92.69%～99.82%和93.63%～99.67%;G蛋白编码区氨基酸变异最高,而F蛋白相对保守。糖基化位点分析发现,该病毒的F蛋白有6个N-糖基化位点,未发现O-糖基化位点,此结果与原型株long株相同;G蛋白N-糖基化位点有6个,O-糖基化位点为82个,而原型株long株有11个N-糖基化位点,15个O-糖基化位点。本研究对2017年河南省漯河市SARI病例中一株HRSVA病毒全基因组序列进行了测定,与世界其他地区报道的HRSVA亚型病毒全基因组序列进行了对比分析,揭示了SARI病例中我国HRSV优势流行ON1基因型病毒全基因组的核苷酸和氨基酸变异特征,以及G蛋白和F蛋白编码区糖基化情况,丰富了我国HRSV基因数据库,也为HRSV的核酸检测方法的建立、疫苗研发和预防性单克隆抗体的评价提供了核苷酸和氨基酸的基础数据。

Human respiratory syncytial virus(HRSV) infection is one of the leading causes of acute respiratory tract infection in young children worldwide. HRSV could be divided into two subgroups, subgroup A(HRSVA) and subgroup B(HRSVB), based on its reactivity with monoclonal antibodies. We obtained one complete genome of HRSVA from hospitalized cases with severe acute respiratory infection(SARI) in Luohe City Henan Province, China, during 2017 using Sanger sequencing process. Sequence editing and alignment, phylogenetic analyses, amino-acid variation and glycosylation were conducted using Sequencher 5.4.5, MEGA 5.05 and BioEdit 7.0.5 software. The HRSVA strain in our study was the ON1 genotype, the most prevalent HRSV subgroup A circulating in China in recent years, based on phylogenetic analysis of the complete genomes and also with 11 individual protein-coding regions. Comparison between RSVAs/Luohe.Henan and 35 representative global strains demonstrated that the homology of nucleotides and amino acids was 92.69%~99.82% and 93.63%~99.67%, respectively;genetic variation was highest in the G-protein encoding region, whereas F protein was highly conserved. Six N-glycosylation sites were predicted for F protein, but no O-glycosylation was found, which was similar to the prototype long strain. In addition, different from the prototype long strain, 82 potential O-linked glycosylation sites and 6 N-glycosylation sites were predicted for G protein. In the present study, the whole-genome sequence was obtained directly from the clinical specimen of a SARI patient in Luohe City, China, during 2017.Compared with HRSVA viruses from other parts of the world, we illustrated the genetic characteristics of nucleotides and amino acids of ON1 genotype of HRSVA subtype virus, the most prevalent virus circulating in China in recent years, and glycosylation for F and G protein-coding regions were also analyzed. We obtained basic genetic data of nucleotides and amino acids, which enriched Chinese HRSV genetic database, will be useful for the development of nucleic acid detection assay, vaccine development and evaluation of prophylactic monoclonal antibodies.