呼吸道合胞病毒北京地区分离株G蛋白的基因分析

从经单克隆抗体证实为Ａ亚型的北京地区呼吸道合胞病毒（ＲＳＶ）分离株Ｂ７９中,用ＲＴ－ＰＣＲ扩增出编码Ｇ蛋白的基因片段,克隆至载体ｐＴＺ１８Ｒ中。经核苷酸序列测定证明,我国北京地区分离的Ａ亚型株Ｂ７９与ＲＳＶＡ亚型原型株（Ａ２株）Ｇ蛋白基因的核苷酸同源性为９３．８％,核苷酸的有义突变率达６５％。由核苷酸推导出氨基酸序列的同源性为８９．６％。氨基酸的变异主要集中在胞外区一个高度保守区的两端,而胞内区和跨膜区相对保守。本文探讨了我国北京地区ＲＳＶ分离株的Ｇ蛋白基因同原型株之间的变异,在疫苗研制中的意义。     

浙江地区呼吸道合胞病毒G基因分子特征分析

收集2004年冬季浙江省儿童医院呼吸道感染患儿的鼻咽吸引物,进行呼吸道合胞病毒(RSV)分离,对分离株用特异性RT-PCR鉴定;对鉴定阳性的RSV毒株进行G蛋白全基因序列测定,并与RSV国际标准株及各地参考株的G蛋白基因序列进行同源性比较并构建基因进化树。结果表明,在4株RSV浙江分离株中,3株G蛋白基因ORF全长897bp,另1株为894bp;各分离株之间的核苷酸与氨基酸同源性分别为98.05%、97.06%;与A型RSV标准株的核酸同源性为95.69%,与B型RSV标准株的同源性为78.79%;其3’端基因高变区核苷酸序列与RSVGA2亚型的同源性最高。提示2004年冬季浙江省RSV流行株属于RSVGA2亚型。     

浙江地区呼吸道合胞病毒G基因分子特征分析

收集2004年冬季浙江省儿童医院呼吸道感染患儿的鼻咽吸引物,进行呼吸道合胞病毒(RSV)分离,对分离株用特异性RT-PCR鉴定;对鉴定阳性的RSV毒株进行G蛋白全基因序列测定,并与RSV国际标准株及各地参考株的G蛋白基因序列进行同源性比较并构建基因进化树.结果表明,在4株RSV浙江分离株中,3株G蛋白基因ORF全长897bp,另1株为894bp;各分离株之间的核苷酸与氨基酸同源性分别为98.05%、97.06%;与A型RSV标准株的核酸同源性为95.69%,与B型RSV标准株的同源性为78.79%;其3'端基因高变区核苷酸序列与RSV GA2亚型的同源性最高.提示2004年冬季浙江省RSV流行株属于RSV GA2亚型.     

呼吸道合胞病毒在北京地区分离株G蛋白的基因分析

从经单克隆抗体证实为Ａ亚型的北京地区呼吸道合胞病毒（ＲＳＶ）分离株Ｂ７９中,用ＲＴ－ＰＣＲＴ扩增出编码Ｇ蛋白的基因片段,克隆至载体ｐＴＺ１８Ｒ中,经核苷酸序列测定证明,我国北京地区分离的Ａ亚型株Ｂ７９与ＲＳＶＡ亚型原型株（Ａ２株）Ｇ蛋白基因的核苷酸同源性为９３．８％,核苷酸的有义突变率为６５％,由核苷酸推导出氨基酸序列的同源性为８９．６％,氨基酸的变异主要集中在胞外区一个高度保守区的两端,而胞内区     

西藏地区儿童急性呼吸道感染中呼吸道合胞病毒的初步研究

本研究为了解西藏地区儿童急性呼吸道感染中呼吸道合胞病毒(Respiratory syncytial virus,RSV)及基因型别。首先采用直接免疫荧光法检测2011年4～7月西藏自治区人民医院儿科病房因急性呼吸道感染住院患儿的鼻咽分泌物标本中7种常见的呼吸道病毒及人类偏肺病毒(Human metapneumovirus,hMPV)的抗原。然后对RSV抗原阳性的标本分别提取RNA,用逆转录-巢式聚合酶链反应法(Nest-PCR)确定RSV型别,同时用实时荧光PCR(Real-Time PCR)方法进行验证。再通过对G蛋白基因PCR扩增产物序列测定确定RSV的基因型。通过与GenBank中不同地区RSV分离株的G蛋白基因序列比对,了解西藏地区RSV G蛋白的结构特点及变异情况。结果表明,从167例标本中检测出呼吸道病毒抗原阳性的为65例,总阳性率为38.9%(65/167),其中RSV 45例,占阳性标本的69.2%(45/65),对其中42例RSV阳性标本进行了PCR分型,其中40例为A亚型,2例为B亚型。对7株A亚型RSV G蛋白基因PCR产物测序结果显示,全部为GA2基因型。西藏RSV与RSV原型株A2株核苷酸的同源性为90.7%～91.8%,氨基酸的同源性只有86.5%～87.2%。氨基酸的变异主要集中在胞外区一个高度保守序列的两端。7株西藏A亚型RSV G蛋白的核苷酸序列与GenBank中不同的RSV分离株相比同源性为90.7%～91.8%。西藏地区2011年春季小儿急性呼吸道感染的病毒病原主要为呼吸道合胞病毒,A亚型是2011年西藏地区的流行优势型别,其G蛋白胞外区基因具有较高的变异性。     

近年北京人偏肺病毒基质蛋白、小疏水蛋白和粘附糖蛋白的遗传变异特征分析

为了探讨北京地区儿童中流行的人偏肺病毒(Human metapneumovirus,hMPV)结构蛋白基因特征,本研究着重对hMPV北京地区地方株的基质蛋白(Matrix protein,M)、小疏水蛋白(Small hydrophobic protein,SH)和粘附蛋白(Attachment protein,G)基因进行了基因特征的分析。本研究对2006年至2010年42株hMPV的M蛋白、49株SH蛋白和55株G蛋白基因特征进行了分析,进化分析显示北京地区流行的hMPV的这3个编码蛋白基因分别属于A2、B1和B2基因亚型。地方株M基因高度保守,A和B基因型之间存在7个氨基酸位点的变异(型内高度保守)。不同基因型(A和B)和不同基因亚型(A2和B1、A2和B2)之间的SH基因的氨基酸同源性在60.7%～64.4%之间,而同一基因亚型内的氨基酸同源性则在93.3%～100%之间;同一基因型不同基因亚型之间(B1和B2)的氨基酸同源性在84.7%～88.7%之间。不同年份不同基因亚型G蛋白具有遗传多样性,使用不同的终止密码、核苷酸缺失和插入导致其核苷酸长度不同,变异程度相当高。不同基因型和不同基因亚型之间的G基因的氨基酸同源性在34.0%～38.6%之间,同一基因亚型内的氨基酸同源性在81.5%～100%之间;同一基因型不同基因亚型之间的氨基酸同源性在64.3%～69.2%之间。2008年至2010年的B2基因亚型的毒株大多数在多个位点出现了相同的氨基酸突变,同时出现了2个氨基酸的插入或重复插入,这些毒株在B2基因亚型内形成了一个新的进化簇。抗原位点预测分析显示不同基因亚型的SH和G蛋白的抗原位点均存在差异。     

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

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。     

鸭甲肝病毒3型2012年山东分离株VP1基因的序列分析

为揭示近年来鸭甲肝病毒3型(DHAV-3)中国分离株VP1基因的遗传变异规律,本研究对2012年从山东省分离到的13株DHAV-3的VP1基因分别进行PCR扩增、序列测序与分析。结果显示,13株DHAV-3的VP1基因均由720个核苷酸组成,共编码240个氨基酸,核苷酸序列和氨基酸序列同源性分别为94.6%～99.9%和95.0%～100%。与GenBank中公布的31株DHAV-3的VP1基因的核苷酸和氨基酸序列同源性分别为92.5%～100%和90.8%～100%。系统进化分析显示,DHAV-3可分为两个基因型,其中除疫苗毒B63之外所有中国分离株均属于GⅠ型,越南分离毒株主要属于GⅡ型S1亚型,而韩国分离株组成GⅡ型中的S2亚型,具有明显的地域特征。     

中国西藏小反刍兽疫病毒野生株China/Tib/Gej/07-30基质蛋白基因和融合蛋白基因的分子特征分析

对我国西藏小反刍兽疫病毒野生株China/Tib/Gej/07-30进行基质蛋白(M)和融合蛋白(F)基因序列测定,并进行分子生物学特征分析。首先应用逆转录聚合酶链式反应扩增出M和F基因片段,对聚合酶链式反应产物进行直接测序,然后对测定的核苷酸和推测的氨基酸序列进行比较分析。China/Tib/Gej/07-30的M基因由1483个核苷酸组成,编码335个氨基酸,与其他分离株核苷酸和氨基酸序列同源性分别为92.4%～97.7%和97.0%～98.2%。F基因由2411个核苷酸组成,编码546个氨基酸,与其他分离株核苷酸和氨基酸序列同源性分别为85.5%～96.1%和94.3%～98.2%。China/Tib/Gej/07-30的F蛋白含有信号肽序列和跨膜结构域,序列高度变异。F蛋白第104～108位和第109～133位氨基酸位点分别是高度保守的裂解位点和融合肽结构域。F蛋白还含有序列高度保守的三个七肽重复区。China/Tib/Gej/07-30的M基因3′端的非编码区(UTR)长度为443个核苷酸,GC含量高达68.4%,与其他PPRV毒株的同源性为82.4%～93.5%。China/Tib/Gej/07-30的F基因5′UTR区长度为634个核苷酸,GC含量高达70.0%,与其他PPRV毒株序列相似性为76.2%～91.7%。     

2009年云南省2株肠道病毒71型分离株全基因组序列遗传特性分析

对2009年云南省肠道病毒71型分离株KMM09和KM186-09进行全基因组序列测序,并与我国及其它国家流行的EV71基因型进行比较和进化分析。KMM09和KM186-09基因组长为7 409bp,编码2 193个氨基酸,VP1系统进化分析显示2009年云南分离株属于C4基因型的C4a亚型。在结构区,与其它基因型相比较,C基因型之间的核苷酸和氨基酸的同源性高于其它基因型;而在非结构区,C4与B基因型和CA16原型株G10同源性高于其它C基因亚型。通过RDP3重组软件和blast比对分析,发现EV71C4基因型与B3基因型,与CA16原型株G10的基因组在非结构区存在重组。EV71全基因组序列的比较和分析,对了解引起我国手足口病暴发或流行C4基因亚型EV71毒株的遗传特性具有重要意义。     

猪瘟病毒强弱毒株和野毒株E2全基因序列测定及比较分析

为了比较猪瘟病毒 (HCV)野毒株、疫苗株及标准株之间E2基因抗原区域的差异 ,采用RT PCR扩增了HCV石门株、兔化弱毒疫苗株、野毒 0 3及 0 7株的囊膜糖蛋白E2 (gp55)全基因的cDNA片段 ,分别克隆于pGEM T载体中并对其进行了核苷酸序列测定及氨基酸序列的推导 ,同时进行了同源性比较及E2结构与功能的分析。所测 4株HCVE2基因的长度均为1 2 73bp,所编码的氨基酸序列均包括部分信号肽序列和完整的跨膜区序列 ,共由 381个氨基酸组成 ;4个毒株E2蛋白N末端的 683位至 690位信号肽序列 (WLLLVTGA)和C末端 1 0 30～1 0 63位跨膜区均为保守序列 ,而且具疏水性 ;N末端抗原功能区中 ,4个E2蛋白与其它所比较序列在位于第 753位至 759位氨基酸处 ,均有一段保守序列RYLASLH ,无一氨基酸发生变异 ,为亲水性 ,在整个E2蛋白抗原谱中抗原性峰值为最高 ,推测对抗原性产生起重要作用 ;4个E2蛋白的氨基酸序列中均含有 1 5个半胱氨酸 (Cys)残基 ,其数量及位置与国外五株HCV(Brescia ,C ,Alfort.ALD和GPE)完全一致。表明…     

Genetic diversity of the attachment protein of subgroup B respiratory syncytial viruses.

Respiratory syncytial (RS) virus causes repeated infections throughout life. Between the two main antigenic subgroups of RS virus, there is antigenic variation in the attachment protein G. The antigenic differences between the subgroups appear to play a role in allowing repeated infections to occur. Antigenic differences also occur within subgroups; however, neither the extent of these differences nor their contributions to repeat infections are known. We report a molecular analysis of the extent of diversity within the subgroup B RS virus attachment protein genes of viruses isolated from children over a 30-year period. Amino acid sequence differences as high as 12% were observed in the ectodomains of the G proteins among the isolates, whereas the cytoplasmic and transmembrane domains were highly conserved. The changes in the G-protein ectodomain were localized to two areas on either side of a highly conserved region surrounding four cysteine residues. Strikingly, single-amino-acid coding changes generated by substitution mutations were not the only means by which change occurred. Changes also occurred by (i) substitutions that changed the available termination codons, resulting in proteins of various lengths, and (ii) a mutation introduced by a single nucleotide deletion and subsequent nucleotide insertion, which caused a shift in the open reading frame of the protein in comparison to the other G genes analyzed. Fifty-one percent of the G-gene nucleotide changes observed among the isolates resulted in amino acid coding changes in the G protein, indicating a selective pressure for change. Maximum-parsimony analysis demonstrated that distinct evolutionary lineages existed. These data show that sequence diversity exists among the G proteins within the subgroup B RS viruses, and this diversity may be important in the immunobiology of the RS viruses.     

Nucleotide sequence analysis of cDNA encoding the coat protein of cucumber mosaic virus: genome organization and molecular features of the protein

The cDNA sequence coding for the coat protein of cucumber mosaic virus (Japanese Y strain) was cloned, and its nucleotide sequence was determined. The sequence contains an open reading frame that encodes the coat protein composed of 218 amino acids. The nucleotide and deduced amino acid sequences of the coat protein of this strain were compared with those of the Q strain; the homologies of the sequences were 78% and 81%, respectively. Further study of the sequences gave an insight into the genome organization and the molecular features of the coat protein. The coding region can be divided into three characteristic regions. The N-terminal region has conserved features in the positively charged structure, the hydropathy pattern and the predicted secondary structure, although the amino acid sequence is varied mainly due to frameshift mutations. It is noteworthy that the positions of arginine residues in this region are highly conserved. Both the nucleotide and amino acid sequences of the central region are well conserved. The amino acid sequence of the C-terminal region is not conserved, because of frameshift mutations, however, the total number of amino acids is conserved. The nucleotide sequence of the 3'-noncoding region is divergent, but it could form a tRNA-like structure similar to those reported for other viruses. Detailed investigation suggests that the Y and Q strains are evolutionarily distant.     

猪瘟病毒石门株与兔化弱毒株gp55基因的克隆与序列分析

猪瘟病毒石门系强毒株及兔化弱毒疫苗株（ＨＣＬＶ株）是我国的标准毒株,囊膜糖蛋白ｇｐ５５（又称Ｅ１）是该病毒最重要的保护性抗原。本实验采用反转录ＰＣＲ扩增了这两个毒株的ｇｐ５５基因。序列分析结果表明：１．石门株和兔化弱毒株糖蛋白Ｅ１的氨基酸序列含有１５个半胱氨酸残基（Ｃｙｓ）,其数量及位置与国外４株猪瘟病毒（Ａｌｆｏｒｔ、Ｂｒｅｓｃｉａ、ＡＬＤ和ＧＰＥ＾－）完全一样。Ｅ１中Ｃｙｓ的数量及位置的保守性     

猪生殖和呼吸综合征病毒B13株ORF7基因的克隆及在杆状病毒系统中的表达

利用单管RT－PCR方法扩增猪生殖和呼吸综合征病毒（PRRSV）分离株B13株包括ORF7基因的片段,并对其序列进行了测定,结果PRRSV分离株B13ORF7基因长度为384bp,编码128个氨基酸组成的15kD蛋白。与已发表的PRRSV LV株、VR－2332株进行同源性比较,发现核苷酸同源性分别为99.2%、59.4%;氨基酸同源性分别为98.4%、54.7%。。表明PRRSV分离株B13在基因结构上可能与LV株同属于欧洲亚群。同时构建了重组转移载体质粒pAcGHLT-B-ORF7,且该重组转移载体质粒与线性化苜蓿丫纹夜蛾核型多角体病毒（AcMNPV-SVI^-G)基因组DNA（baculo gold linearized baculovirus DNA）共转染草地夜蛾（Spodoptcra frugiperda,Sf9）细胞,得到重组病毒AcMNPV-OCC^--GST-6xHis-ORF7。在感染了重组病毒的Sf9细胞中检测到分子量为46kD的ORF7基因的GST融合蛋白表达产物,能被猪抗PRRSVB13株多克隆血清所特异识别。此结果为PRRS新型诊断抗原的研制奠定了基础。     

Identification of multiple isoforms of the low-affinity human IgG Fc receptor

Two varieties of similar, but structurally distinct, cDNA clones for the human low-affinity receptors for the Fc portion of immunoglobulin G (FcγRII) have been isolated. One type of clone was obtained from human B lymphocytes, and the other from PHA-activated peripheral T cells and monocytes. Transfection of both prototype clones into Cos-7 cells and subsequent specific staining with monoclonal antibodies of the CDw32 group confirmed the identification of the gene products. The nucleotide sequence of the cDNA clone from B lymphocytes contains an open reading frame that encodes a protein of relative mass (M _r) 27000 with an extracellular domain of 179 amino acids containing three potential N-glycosylation sites, a 26 amino acid transmembrane domain, and a 44 amino acid cytoplasmic domain. The clones from peripheral T cells and monocytes both encoded a protein ofM _r 31000 with a 179 amino acid extracellular domain containing two potential N-glycosylation sites and a 26 amino acid transmembrane domain. The two types of clones had similar sequences in their immunoglobulin-like extracellular and transmembrane domains, but differed in their leader sequences and 3′-untranslated regions. The most notable difference between the clones was the presence of a distinctive 76 amino acid cytoplasmic domain in those isolated from T cells and monocytes.     

Molecular basis of host range variation in avian retroviruses.

Previous genetic analysis has localized the region of the Rous sarcoma virus (RSV) env gene responsible for host range specificity to that encoding the middle one-third of gp85. To better understand the host range determinants, the relevant regions of the genomes of infectious molecular clones of the transformation-defective Prague strain of RSV, subgroup B (Pr-RSV-B) and Rous-associated virus 0 (RAV-0) (subgroup E) were sequenced and compared with the sequence of Pr-RSV-C. This comparative analysis identified two variable regions of low amino acid sequence homology flanked by highly conserved amino acid sequences. The first variable region (hr1) begins at base 5654 in the Pr-RSV-C sequence and encodes 32 amino acids. The second variable region (hr2) begins at base 5846 and encodes 27 amino acids. To test the role of the variable regions in host range specificity, we determined the sequence of this region of the env gene of NTRE-4, a recombinant virus between Pr-RSV-B and RAV-0 which exhibits an extended host range. This analysis revealed that the recombinant subgroup-encoding region of NTRE-4 is composed of 200 bases of RAV-0 sequence, including hr2, flanked by sequences which are otherwise of Pr-RSV-B origin. This study indicates that hr1 and hr2 are the domains of gp85 responsible for host range determination in avian retroviruses.