河北省HIV-1流行株的env基因序列测定和亚型分析

目的了解河北省HIV-1亚型的分布特点和传播方式,推测流行时间,预测流行趋势。方法采集HIV感染者的全血样品,分离外周血单核细胞(PBMC),提取前病毒DNA,使用套式聚合酶链反应(nested-PCR),扩增HIV-1的env基因的C2-V3区并进行序列测定和亚型分析。结果对22份HIV-1感染者的样品,扩增得到了18份HIV-1envC2-V3基因片段,经序列测定和基因分析鉴定出3种HIV-1M亚群基因亚型,即:B′、CRF-BC和C亚型。B′亚型的组内基因离散率为7.84%±3.14%(n=14),基因序列与云南瑞丽株rl42(泰国B亚型)相近;2株CRF-BC亚型与广西毒株的基因离散率为4.60%。与血液途径感染有关的人员均为B′(泰国B)亚型。结论目前,在河北省发现了3种HIV-1亚型。输供血途径中B′亚型仍是主要的流行亚型,可能来源于云南吸毒人群。HIV-1B′亚型在河北省的流行时间大约为7~9年。     

32例有偿献血感染者HIV-1膜区序列测定及V3环氨基酸变异特点分析

目的 了解我国有偿献血人群中HIV-1B'亚型流行株的膜蛋白V3环序列特征.方法 巢式PCR扩增前病毒DNAc2-c3区后测序,进行病毒亚型鉴定和V3环序列特点分析.结果 所检的32个HIV-1B'亚型株V3环顶端四肽有五种形式.AIDS组与无症状感染组相比前者呈现更多的T/SI型毒株V3环变异特点.结论 我国有偿献血人群中HIV-1 B'亚型流行株V3环顶端四肽有多种形式.处于病程不同时期的患者体内病毒V3区呈现不同的氨基酸变异特点和电荷积累趋势,提示可能具有不同的生物学表型特征.     

呼吸道合胞病毒G蛋白胞外区基因克隆及序列分析

目的 对呼吸道合胞病毒Ｇ蛋白胞外区基因进行克隆及序列分析。方法 从ＲＳＶ感染的喘息型支气管炎患儿咽试子分离的病毒培养物中提取病毒ＲＮＡ,进行逆转录及ＰＣＲ扩增,克隆到Ｇ蛋白胞外区基因ＤＮＡ序列分析。结果 克隆片段全长６９０ｂｐ,编码一个含有２２９个氨基酸的多肽。与５个ＧｅｎＢａｎｋ中不同的ＲＳＶ分离株（包括Ａ,Ｂ亚型）的Ｇ蛋白胞外区的氨基酸序列相比,Ａ亚型的ＲＳＶ毒株氨基酸水平的同源率为９５．２％     

HIV-1型中国株E、B亚型gag基因的克隆与表达

目的 克隆和表达人免疫缺陷病毒（ＨＩＶ）Ⅰ型中国株Ｅ、Ｂ亚型代表株的结构基因ｇａｇ。方法 在分子流行病学调查的基础上，选择１份经部分ｇｐ１２０基因测序判定为Ｅ亚型和１份经部分ｇｐ１２０基因测序判定为Ｂ亚型的代表性样品。利用套式聚合酶链反应（ＰＣＲ），扩增外周血中的前病毒。获得了结构基因ｇａｇ全长片断，并先后克隆到ｐｌｉｎ８Ｐｒ５５和ｐＦａｓｔＢａｃｌ载体中，我们首次克隆到全长的中国株Ｅ亚型ｇａｇ基     

湖北省HIV-1流行株gag基因序列测定及亚型分析

目的 了解湖北省HIV-1感染者流行毒株亚型分布和流行趋势.方法 随机采集湖北省HIV-1感染者的抗凝全血标本,分离血浆,提取病毒RNA,用套式聚合酶链反应扩增HIV-1病毒gag基因,并进行序列测定和亚型分析.结果 对80份HIV-1感染者的样品进行扩增,得到了62份样品的HIV-1基因片段.共发现7种HIV-1亚型和流行重组株.泰国B'亚型占11.3％ (7/62),欧美B亚型占4.8％ (3/62),G亚型占4.8％ (3/62),CRF07-BC占22.6％ (14/62),CRF08-BC占6.5％(4/62),CRF01-AE占48.4％(30/62),CRF15-01B占1.6％ (1/62).在湖北省发现了CRF15-01B和G亚型.结论 湖北省存在多种HIV-1亚型和流行重组型,CRF01-AE、CRF07-BC两种重组亚型毒株为目前湖北省HIV-1流行优势毒株,应加强对HIV-1毒株亚型变异的监测,及时调整防治策略.     

北京市男男性接触HIV-1感染者膜蛋白基因序列测定及亚型分析

目的 了解北京市男男性接触人群(MSM)中HIV-1的最新流行趋势及膜蛋白V3环序列特征.方法 巢式聚合酶链式反应(n-PER)扩增2007年提取的北京市男男性接触HIV感染者基因组DNA样品,对膜蛋白基因C2-V3区测序,进行病毒亚型及V3环序列特点分析.结果 11例样本中,4例是欧美B亚型,5例是AE重组亚型,1例是BC重组亚型,1例是01B重组亚型.V3环顶端四肽以GPGQ和GPGR为主.结论 北京市男男性接触HIV-1感染者中重组亚型呈蔓延流行趋势.     

登革2型病毒NGC株E基因扩增和部分序列分析

目的 体外扩增、克隆登革2型病毒（NGC株）包膜糖蛋白E基因约1．5kb的基因片段,并对目的基因片段进行部分碱基序列测定和分析。方法 采用逆转录聚合酶链反应扩增出E目的基因片段,经限制性内切酶Kpn1/Xbal酶切后用低熔点琼脂糖挖块回收法回收纯化,插入真核表达载体pcDNA3的多克隆位点,构建重组体pcDNA3-E,转化大肠杆菌DH5a,通过对目的基因片段的部分碱基序列测定鉴定克隆的正确性,并分析其氨基酸变异。结果 从登革2型病毒（NGC株）中扩增出约1．5kb的DNA片段,目的基因片段的部分测序与参考序列的同源性为96．53％,7个氨基酸发生变异,4个变异氨基酸与登革2型病毒Jamaica株相应位置的氨基酸相同。结论 体外成功扩增并克隆DV2（NGC株）全长E基因片段,其序列变异及与其他毒株的同源性研究为登革病毒致病机理和疫苗的研究提供材料。     

应用随机PCR方法鉴定一株肠道病毒

目的 从基因水平对一肠道病毒分离株进行分析鉴定,方法 提取病毒RNA,以锚定随机引物反转录合成双链cDNA,用锚定特异引物进行随机扩增,扩增产物进行克隆,测序和序列分析。结果 随机扩增的病毒基因在电泳上呈典型的smear带型;11个随机克隆经GenBank检索,与肠道病毒成员具有最高的同源性且同源率超无穷大0%;11个克隆随机分布于病毒的基因组中,排定后的序列形成4个毗连序列群,共计2261个碱基,涵盖病毒基因组的30%;部分序列与柯萨奇病毒B6型氨基酸同源率达97.3%,参照测定序列合成的引物能够特异性地扩增病毒基因。结论 经序列分析证实小RNA病毒XJ90株为肠道病毒科成员。     

HIV-1 黑龙江省分离株CHNHLJ03009包膜克隆及分析

目的 分析黑龙江省Ⅰ型人免疫缺陷病毒（human irnmunodeficiency virus type 1，HIV-1）原代分离株包膜糖蛋白的变异性及表型特征。方法从一名HIV阳性但未发病的感染者外周血单个核细胞提取DNA，采用保守引物进行HIV包膜直接克隆，进行序列分析及系统树分析。构建了一株带该包膜蛋白的伪病毒并利用表达CXCR4和CCR5的靶细胞进行了感染实验，观察该病毒包膜利用辅助受体的表型特征。结果共获得2个有功能全长env克隆，分别命名为CHNHIJ03009c34（GenBank序列号为AY905493）和CHNHIA03009c33。用全长env氨基酸序列与国内外分离株进行同源性比较分析发现，与分离株CHNHLJ03009c34的包膜同源性最高的病毒为云南的HIV-1 B’亚型分离株RIA2，同源性为91．52％。系统发育分析结果表明，该株为泰国B’亚型，与云南分离株RIA2的遗传距离最近。对包膜蛋白结构分析结果显示，分离株CHNHLJ03009c34包膜在抗原性和亲水性上与RIA2没有明显差别。感染性检测结果显示该病毒只能感染U87．CD4．CCR5细胞，不能感染U87．CD4．CX-CR4细胞。结论本研究从黑龙江省一名HIV-1阳性者克隆到HIV-1CHNHLJ03009病毒的包膜基因，该病毒属于B’亚型（泰国亚型），为R5亲嗜性毒株。该包膜基因克隆为首次报道的黑龙江分离株。     

中国部分甲肝病毒流行株结构蛋白VP3-VPl区基因特点分析

目的分析中国部分甲肝病毒流行株结构蛋白VP3-VPl区基因特点。方法收集42份甲肝患者急性期血清标本,经核酸提取、逆转录及巢氏PCR,测得结构一非结构蛋白VP3-VPl-2A区序列,进行序列同源性比较并分析其基因特点。结果42株HAV病毒株在VPl-2A连接处核苷酸和氨基酸序列同源性分别为89．1％～100％和97．3％～100％;在全长结构蛋白VP3-VPl区的核苷酸和氨基酸序列同源性分别为87．6％～100％和98．8％～100％。VPl-2A连接处序列相同的病毒株在全长结构蛋白VP3．VPl区的核苷酸同源性为98．4％～100％,0～2个氨基酸位点不同。本实验所得序列在中和抗原位点处氨基酸序列均未变异。结论42株病毒株均属于I型,40株是IA亚型,2株IB亚型。本实验所用HAV流行株在结构蛋白VP3．VPl区的核苷酸存在差异但是氨基酸序列高度保守且没有中和抗原位点处的变异。VPl-2A结合处核苷酸序列相同的分离株在全长结构蛋白VP3-VPl区核苷酸序列相同或相近,氨基酸序列保守。     

Near full-length genomic characterization of a HIV type 1 BC recombinant strain from Manipur, India

Genetic complexity of HIV-1 is brought about by recombination between HIV-1 subtypes which leads to the development of epidemiologically significant founder strains. In the present study, the near full-length genome sequence of an HIV-1 isolate from an injecting drug user of Manipur (India) was determined, which evidenced the presence of a novel HIV-1 BC recombinant strain. Near full-length genome was amplified by polymerase chain reaction using primer walking approach. The recombination break points were detected using bootscan and simplot analyses. This isolate exhibited a mosaic structure consisting of subtype C backbone with subtype B insertions at the upstream of pol gene (3026-3259) and the downstream of env gene which spanned till the nef gene (8183-8961). Phylogenetic relationships determined with neighbor-joining trees, revealed that the subtype C sequences clustered with sequences from Indian subtype C HIV-1 strains, and the subtype B sequences clustered with HIV-1 subtype B strains from Thailand. This finding may create a complex scenario of HIV-1 epidemic among the injecting drug users of Manipur in near future.     

Construction and characterization of a full-length infectious clone from a fast-replicating, X4-tropic HIV-1 subtype B′ isolate

In HIV-1 epidemics in China, HIV-1 subtype B′ is the most predominant subtype circulating in intravenous drug users. In this study, we constructed an HIV-1 full-length infectious molecular clone based on the primary virus LWJ, which was isolated from an HIV-infected patient in Fujian Province, China. Phylogenetic and bootscanning analysis of the viral sequence revealed that the isolate LWJ belonged to HIV-1 subtype B′. The infectious clone was designated as “pLWJ”. The virus (LWJ-c) produced from this infectious clone by in vitro transfection of 293T cells could infect both human peripheral blood mononuclear cells (PBMCs) and human the T cell line MT4. Interestingly, the cloned LWJ-c virus utilized CXCR4 as its co-receptor and could replicate in vitro with similar efficiency and kinetics compared to its parental primary isolate LWJ as well as the clade B reference virus NL4-3. The LWJ-c virus could also cause cytopathic effects in both PBMCs and MT cells. Sequence analysis of the envelope glycoprotein of pLWJ showed that a conserved GPGR motif and an arginine at position 11 were present in the V3 loop, which was consistent with previous reports regarding CXCR4 co-receptor usage and syncytium-inducing (SI) phenotype. Thus, the infectious clone represents a fast-replicating, high-producing, CXCR4-tropic and syncytium-inducing isolate. Given the prevalence of HIV-1 subtype B′ in China, this infectious clone can be a very useful tool to provide a versatile molecular model for research focusing on the biological properties of this subtype.     

河南地区HIV-1毒株Gag基因抗原表位变异特征及准种特点研究

目的 探讨中国河南地区人免疫缺陷病毒Ⅰ型(HIV-1)毒株GAG蛋白抗原表位变异特征,并对其准种特点加以分析.方法 套式聚合酶链反应(Nested-PCR)扩增确认HIV阳性样本gagp17～p24基因区段并测序,PCR产物纯化后克隆,挑选克隆株鉴定为阳性后测序,以MEGA(version 3.0)等软件进行分析.结果 河南HIV毒株为B'亚型;gag基因p17区段抗原表位突变有E62G(55.80%),Y79F(48.90%),T84V(48.90%),144V(44.20%),gag基因p24区段抗原表位未见明显变异.结论 HIV-1 B'亚型毒株gag基因p17区段的4个抗原表位,存在较大变异,p24区段较为保守,适合抗原表位疫苗的研制.     

Expression of a processed and a non-processed form of the integrase protein of HIV-1 in the baculovirus system

Summary The integrase (IN) protein of HIV-1 was expressed as a processed and a non-processed protein in the eucaryotic baculovirus expression system. In immunoblots we could demonstrate that recombinant baculoviruses containing the completegag andpol reading frames of HIV-1 expressed a gag/pol precursor polyprotein. The specific proteolytic activity of the recombinant protease on the gag and pol precursor proteins was used for the generation of processed gag (p 17, p 24, p 16) and pol (RT/RNaseH, IN) proteins. The non-processed IN protein, expressed as a polyhedrin fusion protein, was produced at much higher level than the processed protein.     

Identification of 3 phylogenetically related HIV-1 BG intersubtype circulating recombinant forms in Cuba

BG intersubtype recombinants represented 11.6% of HIV-1 isolates in a recent survey in Cuba based on pol sequences, most of them forming a single clade further subdivided into 3 subclades. Here, we analyze 8 near full-length genomes and 1 gag-pol sequence from epidemiologically unlinked Cuban BG recombinants from these 3 subclades (3 from each). Near full-length sequences were also obtained from 3 subtype G and 2 subtype B Cuban viruses. Phylogenetic relationships were estimated via maximum likelihood, and mosaic structures of the recombinants were inferred with the bootscanning, MaxChi, Genconv, and GARD methods. For the near full-length genomes, all recombinants formed a strongly supported clade further subdivided into the same subclades previously defined in pol. Mosaic structures were identical within each subclade and different among subclades, although 5 breakpoints were coincident among all recombinants. Individual phylogenetic trees for nonrecombinant fragments (concatenated B and G subtype segments) indicated a common ancestry for the parental viruses and their relationships to local subtype B and G strains. These results allow us to identify 3 new BG intersubtype circulating recombinant forms in Cuba derived from a common recombinant ancestor, which originated from B and G subtype parental strains circulating in Cuba.     

Distribution of human immunodeficiency virus type 1 subtypes in the State of Amazonas,Brazil, and subtype C identification

Few studies have reported the molecular epidemiological characterization of HIV-1 in the Northern region of Brazil. The present study reports the molecular and epidemiological characterization of 31 HIV-1 isolates from blood donors from the State of Amazonas who donated blood between April 2006 and March 2007. Serum/plasma samples from all donors were screened for HIV antibodies by ELISA and the results confirmed by Western blot analysis. Genomic DNA was extracted from the buffy coat using the Super Quik-Gene-DNA Isolation kit. Nested PCR was performed on the env, gag, and pol regions of HIV-1 using the Gene Amp PCR System 9700. Sequencing reactions were performed using the inner PCR primers and the DYEnamic™ ET Dye Terminator Kit, and phylogenetic analysis was performed using the gag, pol, and env gene sequences. We collected samples from 31 blood donors who tested positive for HIV-1 in confirmatory experiments. The male:female ratio of blood donors was 3.4:1, and the mean age was 32.4 years (range: 19 to 61 years). Phylogenetic analysis showed that subtype B is the most prevalent among Northern Brazilian HIV-1-seropositive blood donors. One HIV-1 subtype C and one circulating recombinant form (CRF_BF) of HIV-1 were identified in the State of Amazonas. This is the first study showing the occurrence of a possible “homogenous” subtype C in this region of Brazil. This finding could contribute to a better characterization of the HIV-1 strains that circulate in the country. Key words: HIV-1; Subtypes; Phylogenetic analysis; Blood donors; Molecular and epidemiological characterization     

26例有偿献血员HIV-1基因分型与变异特征

目的分析某地区有偿献血人员中流行的人免疫缺陷病毒1型（HIV-1）gag、pol、env基因亚型及基因变异特征。方法提取HIV-1感染者外周血单核细胞（PBMC）DNA,经巢式PCR（NestedPCR）扩增gag（p17-p24）、pol（PR＊RT）、env（C2-V5）基因片段,纯化测序后用MEGA5．0等生物学软件对核苷酸序列进行分析。结果23份样本为B亚型,2份为B亚型与C亚型重组,1份为CRF01-AE与B亚型重组。PR区未发现蛋白酶抑制剂主要耐药性突变,RT区检测到核苷类逆转录酶抑制剂耐药性突变M184V和非核苷类逆转录酶抑制剂耐药性突变K101E,G190A。结论流行于该地区的HIV-1毒株以B亚型为主。大多数毒株对常规抗病毒药物仍然敏感,使用HARRT治疗方案依然有效。CXCR4型辅助受体的毒株顶端四肽多为GPGR（91．7％）,提示GPGR可能与疾病的进展有关。     

Coat Protein Sequence Analysis Reveals Occurrence of New Strains of Sweet Potato Feathery Mottle Virus in Uganda and Tanzania

As subtype C is the most prevalent circulating human immunodeficiency virus type 1 (HIV-1) subtype internationally as well as locally in South Africa, more information on the biological nature and molecular characteristics of these viruses is required. Proviral DNA was isolated from primary cultures of three South African R5 isolates and the near-full length genome amplified by PCR. The resultant PCR product was cloned into the pCR-XL-TOPO vector and a representative clone from each isolate sequenced by primer walking. Phylogenetic analysis showed all three clones clustered within subtype C with a bootstrap value of 100%, and no recombination with other subtypes was identified by distance scan and bootscan analysis. Analysis of the potential coding regions revealed premature truncations of the second rev exon but no other potential structural distortions nor frameshift mutations in the open reading frames. All the clones contained three potential NF-B binding sites, a feature unique to subtype C viruses. The tips of the V3 loops contained the GPGQ sequence motif characteristic of CCR5-utilising subtype C strains, as well as relatively low overall net positive charge characteristic of non-syncytium-inducing isolates. This information contributes to our overall knowledge of circulating strains in South Africa and to the making of effective vaccines and chemotherapeutic agents.