犬传染性肝炎病毒Hexon蛋白Loop1、Loop2基因的克隆与表达

犬传染性肝炎病毒（ICHV）主要的中和抗原表位位于六邻体蛋白Loop1、Loop2上。本次研究参考Genebank发表的基因序列设计引物,提取ICHV基因组DNA,,分别PCR扩增六邻体蛋白（Hexon）的Loop1、Loop2基因片段,用T4酶连接在一起,克隆入原核表达载体pET28a中,测序显示本室保存病毒分离株Loop1与CLL株、RI261株和Toronto A26/61株核苷酸序列同源性分别为100%、100%和83.8%;Loop2与CLL株、RI261株和Toronto A26/61株核苷酸序列同源性分别为88.1%、88.1%和99.3%,推导的氨基酸序列同源性分别为93.6%、93.6%和98.6%。转化BL21工程菌,实现了重组Loop蛋白在大肠杆菌中的高效表达,其表达的重组蛋白以包涵体形式存在,分子量约为36kDa,并且利用镍柱纯化重组蛋白,纯度达95%以上。本实验为建立新的犬传染性肝炎病毒基因工程产品奠定了良好的基础。     

犬传染性肝炎病毒Hexon蛋白Loop1、Loop2基因的克隆与表达

腺病毒主要的中和抗原表位位于六邻体蛋白Loop1、Loop2上,目前的研究主要集中在人腺病毒,犬传染性肝炎病毒（即犬腺病毒Ⅰ型）尚未见报道。本次研究参考Genebank发表的基因序列设计引物,提取ICHV基因组DNA,分别PCR扩增六邻体蛋白（Hexon）的Loop1、Loop2基因片段,用T4酶连接在一起,克隆入原核表达载体pET28a中,测序显示本室保存病毒分离株Loop1与CLL株、RI261株和TorontoA26/61株核苷酸序列同源性分别为100%、100%和83.8%;Loop2与CLL株、RI261株和TorontoA26/61株核苷酸序列同源性分别为88.1%、88.1%和99.3%,推导的氨基酸序列同源性分别为93.6%、93.6%和98.6%。转化BL21工程菌,实现了重组Loop蛋白在大肠杆菌中的高效表达,分子质量约为36kDa,并且利用镍柱纯化重组蛋白,纯度达95%以上。用重组蛋白免疫BALB/c小鼠后,以间接ELISA法测定血清抗病毒抗体效价达1：320以上,western blot鉴定免疫血清与ICHV特异性结合。本实验为建立新的犬传染性肝炎病毒基因工程产品奠定了良好的基础。     

长春地区引起婴幼儿肺炎的3、7型腺病毒分子流行病学研究

本文对长春地区1976年—1988年引起小儿肺炎的135株3.7型腺病毒核酸进行了限制性内切酶图谱分析,结果表明:75株7型腺病毒经BamHⅠ、BelⅠ、BglⅠ、XbaⅠ、SmaⅠ、HindⅢ分析后表现为二个基因组型—7b和7d。其中60株7b(88％),流行于1976—1988年;15株7d(12％)自1982年出现逐年增加,到1987—1988年的5株都是7d。60株3型腺病毒被BglⅡ、BamHⅠ分析后表现为三个基因组型,我们用3Ⅰ、3Ⅱ、3Ⅲ代表它们,其中S6株3Ⅰ(93.3％)流行于1976—1888年;3Ⅱ、3Ⅲ散在分布。通过临床资料整理,发现该地区3.7型腺病毒的不同基因组型在毒力致病性上存在着差别。     

表达轮状病毒G2和G3型vp7基因重组腺病毒的免疫效果

为探索以非复制型腺病毒为表达载体的多价轮病毒(Rotavirus,RV)基因工程疫苗的可行性,在前期工作的基础上,对表达我国G2和G3型毒株νp7基因的重组腺病毒的免疫效果进行了研究.分别用表达G2和G3型的νp7基因的重组腺病毒rvAdG2vp7、rvAdG3VP7经滴鼻和灌胃两种途径免疫Balb/c小鼠,对免疫后小鼠的血清抗体、黏膜抗体和相关的细胞因子水平进行了检测和比较。结果表明,用表达G2和G3型νp7基因的管理费用腺病毒经滴鼻和灌胃两种途径免疫小鼠后,可诱导机体产生较强的RV特异性免疫反应,名手体液免疫、细胞免疫和黏膜免疫,并能产生中的抗体.但免疫反应以Th1类反应也占有相当的比例.本研究为新型RV基因工程疫苗的深入研究奠定了基础.     

表达轮状病毒G2和G3型vp7基因重组腺病毒的免疫效果

为探索以非复制型腺病毒为表达载体的多价轮状病毒(Rotavirus,RV)基因工程疫苗的可行性,在前期工作的基础上,对表达我国G2和G3型RV流行毒株vp7基因的重组腺病毒的免疫效果进行了研究。分别用表达G2和G3型vp7基因的重组腺病毒rvAdG2VP7、rvAdG3VP7经滴鼻和灌胃两种途径免疫Balb/c小鼠,对免疫后小鼠的血清抗体、黏膜抗体和相关的细胞因子水平进行了检测和比较。结果表明,用表达G2和G3型vp7基因的重组腺病毒经滴鼻和灌胃两种途径免疫小鼠后,均可诱导机体产生较强的RV特异性免疫反应,包括体液免疫、细胞免疫和黏膜免疫,并能产生中和抗体。但免疫反应以Th2类为主,Th1类反应也占有相当的比例。本研究为新型RV基因工程疫苗的深入研究奠定了基础。     

重组虎源H5N1流感病毒HA基因犬2型腺病毒的构建与实验免疫研究

H5N1流感病毒可以对虎和猫产生致死性感染,为研制可用于预防猫科动物流感的新型疫苗,构建了重组虎源H5N1流感病毒HA基因的犬2型腺病毒。将A/Tiger/Harbin/01/2003(H5N1)的HA基因克隆入pVAX1载体中,然后将含有HA基因的表达盒(CMV HA PolyA)克隆入pVAXΔE3的SSPⅠ酶切缺失处,获得含有HA表达盒的穿梭载体pΔEHA。用SalⅠ NruⅠ分别对pΔEHA和pPoly-2-CAV2进行双酶切,将含有HA表达盒的SalⅠ NruⅠ片段克隆入pPoly2-CAV2,获得了在E3区缺失处插入HA表达盒的重组质粒pCAV-2/HA。释放CAV-2/HA重组基因组转染MDCK细胞,获得了重组活病毒CAV2/HA,经Western blot分析表明重组表达产物可被流感病毒HA单克隆抗体3A13所识别。使用该重组病毒免疫猫可以产生效价为1∶8~1∶16的抗H5亚型流感病毒血凝抑制抗体。     

长春和北京地区引起婴幼儿肺炎的3型与7型腺病毒的分子流行病学研究

对长春和北京地区连续12年(1976年冬至1988年春)引起小儿肺炎的3、7型腺病毒102株标本,进行了限制性内切酶核酸电泳图谱分析。56株7型腺病毒经BamHⅠ、BclⅠ、BglⅠ、XbaⅠ、SmaⅠ、HindⅢ分析后,表现为两个基因组型——Ad7 b和Ad7 d。46株3型腺病毒被Bg1 Ⅱ、BamHⅠ酶解后,表现为 3个基因组型——Ad 3Ⅰ、Ad 3Ⅱ、Ad 3Ⅲ。各基因组型的分布情况是:56株7型腺病毒中,43株为Ad 7 b(76.8％),流行于1976年冬至1986年春;13株是Ad 7 d(23.2％),出现于1982年,与Ad 7 b共同流行;1986年～1988年分析的5株病毒都是Ad 7d。43株3型腺病毒中,Ad3Ⅰ42株(91.0％),分布于12年中;Ad 3Ⅱ、Ad 3Ⅲ各2株,散在分布。此结果表明,国内这12年中引起小儿肺炎的3型腺病毒至少有3个基因组型,7型腺病毒至少有两个基因组型。Ad3Ⅰ和Ad7 b是流行优势基因组型。但自80年代初开始出现Ad7 d以来,有逐年增多的趋势,最近两年的标本又都是Ad7 d,很可能它将取代Ad7 b而成为流行的优势基因组型.     

表达猪圆环病毒2型Cap蛋白重组复制缺陷型人5型腺病毒的构建及小鼠免疫试验

构建表达猪圆环病毒2型Cap蛋白重组复制缺陷型人5型腺病毒,评价其对小鼠免疫效果。本研究将编码PCV2Cap蛋白的ORF2克隆到腺病毒表达系统穿梭质粒,构建了重组穿梭质粒pacAd5CMV-Cap。将被限制性内切酶PacI线性化后的骨架质粒和重组穿梭质粒共转染HEK293AD细胞,两者在真核细胞内同源重组并包装出携带PCV2-Cap基因的复制缺陷型重组人5型腺病毒,命名为rAd5-Cap;以同样方法重组获得了不含任何靶基因的野生型重组腺病毒wt-rAd5。病毒增殖稳定后,rAd5-Cap与wt-rAd5滴度可达到108.5 TCID50/mL左右;一步增殖实验证明,相对于wt-rAd5,rAd5-Cap中Cap基因的引入几乎没有给重组腺病毒增殖造成影响。RT-PCR和间接免疫荧光实验显示,rAd5-Cap能够有效介导PCV2Cap蛋白在真核细胞HEK293AD细胞中表达。以107 TCID50的rAd5-Cap肌肉注射接种小鼠,14d后小鼠血清中产生可检测水平的针对Cap蛋白的体液免疫应答,并且至少在免疫后28d之前抗体水平持续加强。对重组腺病毒的分子生物学鉴定和在小鼠上的初步免疫试验结果表明,重组腺病毒rAd5-Cap可介导Cap蛋白在真核细胞中的表达,并且表达的靶蛋白具有较好的免疫原性,为进一步将其开发成新型PCV2疫苗奠定了基础。     

共表达人p53、GM-CSF和B7-1基因的重组腺病毒的构建

 为开展肿瘤的复合基因治疗 ,构建以串联方式携带人野生型p53、GM CSF和B7 1基因的重组腺病毒穿梭质粒pBB 1 0 2 .将pBB 1 0 2与腺病毒包装质粒GT40 50共转染 2 93细胞 ,通过细胞内同源重组获得重组腺病毒BB 1 0 2 .在 2 93细胞中扩增病毒 ,并通过氯化铯密度梯度超速离心纯化病毒 ,获得高滴度和高纯度的病毒 .分别经免疫组织化学分析、ELISA和流式细胞分析 ,检测BB 1 0 2介导的人野生型p53、GM CSF和B7 1基因在喉癌细胞Hep 2中的表达 .结果表明 ,BB 1 0 2能够有效地将其所携带的目的基因导入Hep 2细胞并使其在细胞中高效表达 ,表达高峰期为转染后 2～ 4d ,此后随时间递减 ,可持续 1 0d以上 .     

人源分泌型血管内皮细胞生长因子受体flt-1（Ⅰ～Ⅳ区）的基因克隆及其腺病毒载体的构建和表达

肿瘤的生长、转移与血管形成密切相关,利用基因治疗的方法将抗血管形成的因子导入体内是目前肿瘤生物治疗研究的重要策略.血管内皮细胞生长因子（VEGF）在血管生成中起重要作用,因此阻断VEGF与相应受体的结合成为抗血管形成的重要靶点.通过RT-PCR从人脐静脉内皮细胞克隆了VEGF受体Flt-1的信号肽及胞外Ⅰ～Ⅳ区cDNA,即可溶性sFlt-1的cDNA片段.利用Ad-Easy体系, 在细菌BJ5183中同源重组后,转染包装细胞293,成功包装出重组flt-1腺病毒,利用它可有效地感染低分化胃黏液腺癌细胞株MGC803.经RT-PCR,免疫沉淀及免疫印迹等不同方法检测表明,被感染细胞能表达并分泌Flt-1的胞外区蛋白,为后续进行抗肿瘤血管形成的基因治疗研究奠定了基础.     

Utilizing the Antigen Capsid-Incorporation Strategy for the Development of Adenovirus Serotype 5-Vectored Vaccine Approaches

Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these traditionally modified Ad5 vectors in clinical trials could be primarily correlated with Ad5 pre-existing immunity (PEI) among the majority of the population. To promote Ad5-vectored vaccine development by solving the concern of Ad5 PEI, the innovative Antigen Capsid-Incorporation strategy has been employed. By merit of this strategy, Ad5-vectored we first constructed the hexon shuttle plasmid HVR1-KWAS-HVR5-His₆/pH5S by subcloning the hypervariable region (HVR) 1 of hexon into a previously constructed shuttle plasmid HVR5-His₆/pH5S, which had His₆ tag incorporated into the HVR5. This HVR1 DNA fragment containing a HIV epitope ELDKWAS was synthesized. HVR1-KWAS-HVR5-His₆/pH5S was then linearized and co-transformed with linearized backbone plasmid pAd5/∆H5 (GL) , for homologous recombination. This recombined plasmid pAd5/H5-HVR1-KWAS-HVR5-His₆ was transfected into cells to generate the viral vector Ad5/H5-HVR1-KWAS-HVR5-His₆. This vector was validated to have qualitative fitness indicated by viral physical titer (VP/ml), infectious titer (IP/ml) and corresponding VP/IP ratio. Both the HIV epitope and His₆ tag were surface-exposed on the Ad5 capsid, and retained epitope-specific antigenicity of their own. A neutralization assay indicated the ability of this divalent vector to circumvent neutralization by Ad5-positive sera in vitro. Mice immunization demonstrated the generation of robust humoral immunity specific to the HIV epitope and His₆. This proof-of-principle study suggested that the protocol associated with the Antigen Capsid-Incorporation strategy could be feasibly utilized for the generation of Ad5-vectored vaccines by modifying different capsid proteins. This protocol could even be further modified for the generation of rare-serotype adenovirus-vectored vaccines.     

The Antiviral Restriction Factors IFITM1, 2 and 3 Do Not Inhibit Infection of Human Papillomavirus,Cytomegalovirus and Adenovirus

Type I interferons (IFN-α and β) induce dynamic host defense mechanisms to inhibit viral infections. It has been recently recognized that the interferon-inducible transmembrane proteins (IFITM) 1, 2 and 3 can block entry of a broad spectrum of RNA viruses. However, no study to date has focused on the role of IFITM proteins in DNA virus restriction. Here, we demonstrate that IFN-α or -β treatment of keratinocytes substantially decreases human papillomavirus 16 (HPV16) infection while robustly inducing IFITM1, 2 and 3 expression. However, IFITM1, 2 and 3 overexpression did not inhibit HPV16 infection; rather, IFITM1 and IFITM3 modestly enhanced HPV16 infection in various cell types including primary keratinocytes. Moreover, IFITM1, 2 and 3 did not inhibit infection by two other DNA viruses, human cytomegalovirus (HCMV) and adenovirus type 5 (Ad5). Taken together, we reveal that the entry of several DNA viruses, including HPV, HCMV, and Ad5 is not affected by IFITM1, 2 and 3 expression. These results imply that HPV, and other DNA viruses, may bypass IFITM restriction during intracellular trafficking.     

人腺病毒55型感染肺部病变与外周血淋巴细胞关系研究

目的:探讨人腺病毒55型感染肺部病变与外周血淋巴细胞改变的关系及致病意义。方法:以50例经胸部CT证实为腺病毒肺炎的患者为研究对象(肺炎组),调查其外周血细胞及T淋巴细胞亚群变化情况,并与同期腺病毒55型感染未出现肺部病变的患者30例(非肺炎组)对照;亚组分析50例肺炎组中多肺叶病变与单肺叶病变患者之间T淋巴细胞变化的差异。结果:与非肺炎组患者相比,肺炎组患者急性期外周血淋巴细胞比例明显降低、单核细胞比例明显升高(P0.01);肺炎组CD3+T淋巴细胞比例、CD3+CD4+T淋巴细胞比例及CD4/CD8比值较非肺炎组均有明显降低(P0.01)。亚组分析显示,肺炎组患者肺部病变范围不同,T淋巴细胞亚群的变化亦有差异,多肺叶病变组患者CD3+CD8+T淋巴细胞比例较单肺叶病变组明显升高、CD4/CD8比值较单肺叶病变组明显降低(P0.05)。结论:HAdv-55感染引起肺炎病变时,宿主存在明显的细胞免疫功能受损,且与肺部病变程度有一定正相关。     

Occurrence and Distribution of Grapevine Leafroll-associated Viruses 1, 2, 3 and 7 in Turkey

Grapevines in central Anatolia region of Turkey were surveyed for the prevalence of grapevine leafroll viruses. The field study and collection of samples were conducted in nine major grapevine‐growing areas. Samples collected from 622 vines were tested for Grapevine leafroll‐associated virus 1, 2, 3 and 7 (GLRaV‐1, ‐2, ‐3 and ‐7). According to diagnostic tests and surveys, 27 of 41 cultivars and 95 of 622 samples (15.27%) were found to be infected at least one virus. GLRaV‐1 (8.36%) was found to be the most frequently encountered virus associated with leafroll disease of grapes, followed by GLRaV‐3 (5.78%), GLRAV‐7 (3.86%) and GLRAV‐2 (2.41%).     

我国丙型肝炎病毒囊膜蛋白E2高变区1的序列特征

对２３例国内献血员、血透析及肝炎病人血清用反转录巢式ＰＣＲ技术扩增了ＨＣＶＲＮＡ囊膜蛋白２基因的ｃＤＮＡ片段,并进行了序列测定。结果表明２３例病人ＨＣＶＥ２／ＮＳ１Ｎ末端的核苷酸及氨基酸序列呈现多样性,高变区１（ＨＶＲ１）位于核苷酸第１４５９～１５５９位,氨基酸第３８４～４１０位;我国ＨＣＶ株ＨＶＲ１２７个氨基酸中有１５个位置氨基酸相对稳定,氨基酸组成与分布均与Ｓｅｋｉｙａ报道的１６６个ＨＣＶ株的不同。结果提示,研究我国ＨＣＶ株ＨＶＲ１的序列特征有助于ＨＣＶ的流行病学研究,对研制适用于我国的抗体诊断试剂盒及进行疫苗研究均有重要的意义。     

Genetic Variation in VP7 Gene of Human Rotavirus Serotype 2 (G2 Type) Isolated in Japan,China, and Pakistan

Sequence analysis of the gene encoding the major neutralization glycoprotein (VP7) was performed on sixteen human isolates of serotype 2 of rotavirus in Japan, China, and Pakistan and their genetic variations were examined. Comparative studies of their nucleotide and deduced amino acid sequences between the sixteen isolates and the HU5 strain revealed an overall homology of more than 94%. A higher degree of homology in nucleotides was observed among the sixteen isolates than between HU5 and the isolates. A total of thirteen amino acid residues frequently converted to another amino acid. Out of the thirteen, five amino acid residues belonging to the major neutralizing epitope regions (C, E, and F in this communication) converted frequently. From the amino acid sequences three subtypes, subtype 1, subtype 2, and intermediate, were suggested to be classified as previously reported for serotype 1 (Xin et al, Virology, 1993, 197: 813-816).