北京市一例HIV-1独特型重组毒株近全长基因组特征分析

Nearly full-length genome characterization of a unique HIV-1 recombinant strain in Beijing

目的分析北京市献血人群筛查中发现的1例HIV-1独特型重组毒株的基因结构和重组特点。方法基于2018年北京市血液筛查时发现的1例HIV核酸阳性抗体阴性的样本,提取病毒RNA并逆转录为cDNA,用近末端稀释法分两段扩增病毒近全长基因组并测定序列。运用RIP、jpHMM和SimPlot3.5软件进行重组分析,同时采用MEGA7软件构建Neighbor-joining系统进化树对该毒株的同源关系进行分析。结果共获得长度为8792 bp的HIV-1近全长基因序列,分析表明该序列由CRF01_AE和CRF07_BC重组片段组成。与Los Alamos HIV Database(www.hiv.lanl.gov/content/index)中收录的全长序列相比该毒株具有3个独特的重组断点,分4个重组片段,分别是ICRF01_AE(790~6035,HXB2),IICRF07_BC(6036~8586,HXB2),IIICRF01_AE(8587~8828,HXB2)和IVCRF07_BC(8829~9411,HXB2)。其中ICRF01_AE区域属于CRF01_AE的C4簇;IICRF07_BC区域属于CRF07_BC的CRF07BC_N簇。结论1例参与献血的HIV核酸阳性而抗体阴性的感染者携带的毒株具有新型独特的重组模式,提示需要加强监测献血人群中HIV毒株的流行情况,为保障安全用血提供科学数据。

Objective To analyze the genomic structure and recombination characteristics of a newly discovered HIV-1 unique recombinant strain found in blood donors in Beijing.Methods In 2018,one sample from blood donation screening in Beijing was tested positive for HIV nucleic acid and negative for HIV antibody.Viral RNA was extracted and reversely transcribed to cDNA.Two segments of nearly full-length viral genome were amplified by near-endpoint dilution method and were sequenced.RIP,jpHMM and SimPlot 3.5 software were used for recombination analysis.The neighbor joining phylogenetic tree was constructed by MEGA 7 to analyze the homology of the strain.Results A nearly full-length genome of HIV-1 with 8792 bp in length was obtained.Genomic analysis indicated that the genome was composed of CRF01_AE and CRF07_BC recombinant fragments.Compared with the full-length sequence of HIV-1 in Los Alamos HIV Database(www.hiv.lanl.gov/content/index),this strain had three unique recombination breakpoints,forming four recombinant fragments,including ICRF01_AE(790-6035,HXB2),IICRF07_BC(6036-8586,HXB2),IIICRF01_AE(8587-8828,HXB2)and IVCRF07_BC(8829-9411,HXB2).The ICRF01_AE belonged to C4 cluster of CRF01_AE,and IICRF07_BC belonged to CRF07BC_N cluster of CRF07_BC.Conclusions The HIV strain from a blood donor with HIV nucleic acid positive and antibody negative indicated a new and unique recombination mode,suggesting the need to strengthen surveillance of prevalent HIV strains in blood donors,so as to provide scientific data for the blood safety.