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Reverse transcriptases of primate viruses as immunological markers 总被引：20，自引：0，他引：20
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H5N1亚型高致病性禽流感病毒A/goose/Guangdong/1/96株反向基因操作系统的建立 总被引：8，自引：0，他引：8
A/goose/Guangdong/1/96（GSGD/1/96）是中国分离的第1株H5N1亚型禽流感病毒，它不仅是97香港感染并致人死亡的H5N1亚型流感病毒HA基因供体株，而且是中国目前已报到的H5亚型流感病毒分离株的共同祖先。本研究建立了该病毒的8质粒反向基因操作系统，并通过细胞转染成功拯救了该病毒（R-GSGD/1/96）。R-GSGD/1/96在对SPF鸡和 Balb/c小鼠的致病性方面保持了与亲本野毒(W-GSGD/1/96)一致的生物学特性，即对鸡都是高致病性毒株，R-GSGD/1/96与W-GSGD/1/96的静脉致病指数分别为2.01和2.10；救获病毒与野生病毒一样，尽管106EID50经鼻腔感染小鼠后1～2 d内能从肺脏检测到低滴度的病毒，但不能在小鼠体内成功复制。GSGD/1/96反向基因操作系统的成功建立为进一步开展中国高致病性禽流感病毒分离株的生物学特性、遗传衍化及结构与其功能关系研究奠定了基础。 相似文献
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The accuracy of reverse transcriptase from HIV-1 总被引：72，自引：0，他引：72
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为了拯救出H3N2亚型流感病毒的重组新病毒,利用反向遗传学手段,8个质粒共同转染293T细胞,包装带有双点突变（第119位氨基酸由E突变为V,第222位氨基酸由I突变成L）、单点突变和野生型的流感病毒H3N2;在MDCK细胞中传代包装成的H3N2病毒。结果表明,野生流感病毒H3N2和其突变株包装成功,第119位氨基酸单点突变型滴度与野生型的相近,而第222位氨基酸单点突变和双突变型滴度要比野生型的低。本实验成功证明了H3N2神经氨酸酶上两个位点（第119和222位氨基酸）对病毒包装及复制起到关键的作用,且NA上第222位氨基酸相对于第119位氨基酸显得要更重要。 相似文献
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Genetic variation in HTLV-III/LAV over time in patients with AIDS or at risk for AIDS 总被引：89，自引：0，他引：89
B H Hahn G M Shaw M E Taylor R R Redfield P D Markham S Z Salahuddin F Wong-Staal R C Gallo E S Parks W P Parks 《Science (New York, N.Y.)》1986,232(4757):1548-1553
In a study of genetic variation in the AIDS virus, HTLV-III/LAV, sequential virus isolates from persistently infected individuals were examined by Southern blot genomic analysis, molecular cloning, and nucleotide sequencing. Four to six virus isolates were obtained from each of three individuals over a 1-year or 2-year period. Changes were detected throughout the viral genomes and consisted of isolated and clustered nucleotide point mutations as well as short deletions or insertions. Results from genomic restriction mapping and nucleotide sequence comparisons indicated that viruses isolated sequentially had evolved in parallel from a common progenitor virus. The rate of evolution of HTLV-III/LAV was estimated to be at least 10(-3) nucleotide substitutions per site per year for the env gene and 10(-4) for the gag gene, values a millionfold greater than for most DNA genomes. Despite this relatively rapid rate of sequence divergence, virus isolates from any one patient were all much more related to each other than to viruses from other individuals. In view of the substantial heterogeneity among most independent HTLV-III/LAV isolates, the repeated isolation from a given individual of only highly related viruses raises the possibility that some type of interference mechanism may prevent simultaneous infection by more than one major genotypic form of the virus. 相似文献
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Isolation of infectious bovine rhinotracheitis virus from the soft-shelled tick, Ornithodoros coriaceus 总被引：1，自引：0，他引：1
Infectious bovine rhinotracheitis virus was isolated from the soft-shelled tick (Ornithodoros coriaceus). Serological identification of the isolated viruses was confirmed by restriction endonuclease digestion of purified virus DNA. These isolations indicate that the soft-shelled tick may be a vector for infectious bovine rhinotracheitis virus. This may be the first reported isolation of mammalian herpesvirus from an arthropod vector. 相似文献
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Isolation of a new virus, HBLV, in patients with lymphoproliferative disorders 总被引：116，自引：0，他引：116
S Z Salahuddin D V Ablashi P D Markham S F Josephs S Sturzenegger M Kaplan G Halligan P Biberfeld F Wong-Staal B Kramarsky 《Science (New York, N.Y.)》1986,234(4776):596-601
A novel human B-lymphotropic virus (HBLV) was isolated from the peripheral blood leukocytes of six individuals: two HTLV-III seropositive patients from the United States (one with AIDS-related lymphoma and one with dermatopathic lymphadenopathy), three HTLV-III seronegative patients from the United States (one with angioimmunoblastic lymphadenopathy, one with cutaneous T-cell lymphoma, and one with immunoblastic lymphoma), and one HTLV-III seronegative patient with acute lymphocytic leukemia from Jamaica. All six isolates were closely related by antigenic analysis, and sera from all six virus-positive patients reacted immunologically with each virus isolate. In contrast, only four sera from 220 randomly selected healthy donors and none from 12 AIDS patients without associated lymphoma were seropositive. The virus selectively infected freshly isolated human B cells and converted them into large, refractile mono- or binucleated cells with nuclear and cytoplasmic inclusion bodies. HBLV is morphologically similar to viruses of the herpesvirus family but is readily distinguishable from the known human and nonhuman primate herpesviruses by host range, in vitro biological effects, and antigenic features. 相似文献
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KLA 16 virus, recovered from a child with Thailand hemorrhagic fever, produces infant mouse, rat, and hamster disease that is characterized by spontaneous bleeding at multiple sites, notably in the gastrointestinal tract, and by marked abnormalities in hemostatic mechanisms. This virus differs in this respect from Chikungunya virus to which it is immunologically similar and from other Thai hemorrhagic fever viruses. 相似文献
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猪瘟病毒C株全长cDNA感染性克隆的构建及病毒拯救 总被引：3，自引：1，他引：2
【目的】建立猪瘟病毒研究技术平台,为进一步研究猪瘟病毒C株在细胞中的增殖机制及猪瘟病毒标记疫苗奠定基础。【方法】本试验以猪瘟病毒C株为研究材料,经RT-PCR扩增获得涵盖全长的6个片段,用合适的酶切位点连接,成功构建了C株全长感染性克隆pAC-CS。体外转录得到RNA,然后将其分别转染BHK-21和SK6细胞。拯救的病毒通过上清传代(常规病毒传代)和带毒细胞传毒繁殖。【结果】通过RT-PCR、免疫过氧化酶单层细胞试验和兔体发热试验检测,表明病毒拯救成功。经比较以电转的方式转染SK6的效果较好。通过带毒细胞传代,至12代时病毒滴度稳定达104TCID50?mL-1,而上清传代至第3代时用免疫过氧化酶单层细胞试验(IPMA)不能检测出病毒。【结论】成功构建了猪瘟病毒C株感染性克隆;拯救C株时以SK6细胞电转较好;带毒细胞传代培养C株有利于获得较高滴度的病毒。 相似文献
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Inhibition of chemical carcinogenesis by viral vaccines 总被引：3，自引：0，他引：3
The incidence of 3-methylcholanthrene-induced subcutaneous tumors was significantly reduced by a single injection of inactivated type C RNA viral vaccine. Rauscher leukemia virus vaccine reduced the incidence of sarcomas from 78 to 50 percent in the BALB/cCr mouse. Radiation leukemia virus vaccine and a vaccine from a wild murine leukemia virus derived from a 3-methylcholanthrene tumor reduced the incidence of sarcoma from 86 percent to 33 and 37 percents, respectively, in the C57BL/6 mouse. These reductions in tumor incidence by virus vaccines help support the concept that type C RNA viruses serve as determinants of chemically induced cancer; additional studies of vaccines made with more purified virus preparations are necessary. 相似文献
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中国部分地区高致病性猪繁殖与呼吸综合征病毒的分子流行病学研究 总被引：11，自引：1，他引：11
【目的】对来自2006年猪病流行爆发地的组织样品进行多种病毒的检测,确定引起本次流行的致病病原及PRRSV的分子流行病学特征。【方法】利用（RT-）PCR对采集的样品进行PRRSV北美型和欧洲型、猪圆环病毒2型（PCV2）、猪血凝性脑脊髓炎病毒（PHEV）、日本乙型脑炎病毒（JEV）以及瘟病毒的检测,对PRRSV阳性的进行ORF5的序列测定并分析。【结果】检测到16份PRRSV北美型阳性样品,PCV2阳性样品2份,其它病毒均未检到。PRRSV ORF5序列分析表明笔者分离到的PRRSV株可分为2个群。【结论】（1）PRRSV与2006年肆虐中国养猪业的猪病流行有直接关系;（2）2006年PRRSV流行株主要是以JX0612株为代表,但不同遗传特征的PRRSV也在流行。 相似文献
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While it is widely appreciated that infection with a virulent virus can produce disease in an animal, the ability of a mixture of avirulent viruses to produce disease by means of complementation or recombination in vivo has not been established. In this study, two weakly neuroinvasive herpes simplex virus type 1 (HSV-1) strains were simultaneously inoculated onto the footpads of mice. Many (62%) of the animals that received a 1:1 mixture of the viruses died, whereas the animals that received a similar or 100-fold higher dose of each agent alone survived. Of fourteen viruses isolated from the brains of ten mice that died after receiving the mixture of the two weakly neuroinvasive viruses, eleven were recombinants; three of these recombinants were lethal when reapplied to the footpads of mice. These results show that two avirulent HSV-1 variants may interact in vivo to produce virulent recombinants and a lethal infection. They also suggest that different genetic lesions account for the weakly neuroinvasive character of the HSV-1 strains ANG and KOS after footpad inoculation. 相似文献
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Chikungunya virus and dengue type 2 virus were isolated from a single blood specimen taken from a patient in the acute phase of a dengue-like illness seen at Christian Medical College Hospital, Vellore, South India, in October 1964. In serial blood specimens collected from this patient there was an increase in antibody to these same two viruses. The technique for unmasking an agent (such as dengue) with a long incubation period in mice in the presence of an agent with a short incubation period is described. 相似文献
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Protective efficacy of an H5/H7 trivalent inactivated vaccine (H5-Re13, H5-Re14, and H7-Re4 strains) in chickens,ducks, and geese against newly detected H5N1, H5N6, H5N8, and H7N9 viruses 
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下载免费PDF全文 ZENG Xian-ying HE Xin-wen MENG Fei MA Qi WANG Yan BAO Hong-mei LIU Yan-jing DENG Guo-hua SHI Jian-zhong LI Yan-bing TIAN Guo-bin CHEN Hua-lan 《农业科学学报》2022,21(7):2086-2094
Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains (H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin (HA) and neuraminidase (NA) genes of an H5N6 virus that bears the clade 2.3.4.4h HA gene, H5-Re14 contains the HA and NA genes of an H5N8 virus that bears the clade 2.3.4.4b HA gene, and H7-Re4 contains the HA and NA genes of H7N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses (an H5N1 virus, an H5N6 virus, and an H5N8 virus) bearing the clade 2.3.4.4b HA gene, an H5N6 virus bearing the clade 2.3.4.4h HA gene, and an H7N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4h or 2.3.4.4b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7N9 viruses that are currently circulating in nature. 相似文献
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采集1例疑似感染猪传染性胃肠炎病毒(TGEV)仔猪的粪便,运用RT-PCR方法和血清学方法对病料进行TGEV检测,并应用猪睾丸细胞(ST)进行病毒分离培养,分别采用免疫过氧化物酶单层细胞染色法(IPMA)和RT-PCR方法检测病毒在ST细胞中的增殖动态,应用RT-PCR方法扩增分离TGEV S1基因,经序列测定后,采用DNAStar 7.0和Mega 5.0软件对TGEV进行生物信息学分析。结果表明,病料接种到ST细胞培养后,出现明显细胞病变效应(CPE);RT-PCR检测结果显示,TGEV核酸阳性;血清学鉴定TGEV抗原阳性。将分离毒株命名为TGEV-NY。感染12 h后,IPMA检测结果阳性,且可从细胞培养上清中检出TGEV核酸。序列测定分析表明,分离毒株S1基因开放阅读框(ORF)为2 220 bp,编码740个氨基酸。进化分析显示,分离毒株与我国2006年分离的SC-Y毒株亲缘关系最近,分离毒株属于基因Ⅰ群。 相似文献
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Epidemiologic, clinical, and etiologic studies were carried out on a newly recognized, frequently fatal, pediatric disease syndrome which occurred in urban areas infested with Aedes aegypti mosquitoes. Four types of dengue virus (two of which are new), chikungunya virus, and another virus yet to be identified were isolated from the blood of patients. Dengue viruses, types 2 and 3, were isolated from the mosquitoes. Ample serologic confirmation was obtained of concurrent hemorrhagic fever and infection with one or more of these viruses. Thus, it was discovered that viruses of previously recognized types and of closely related new types apparently have etiologic roles in a new and highly dangerous epidemic disease syndrome. 相似文献
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从患传染性腺胃病的病鸡中分离到4 株病毒,其中H95株在SPF鸡胚上已稳定传代。病料及H95 传代后的鸡胚尿囊液经蔗糖梯度和CsCl密度梯度离心后的纯化物,电镜下为大小80～160 nm 、有囊膜的病毒颗粒,囊膜表面有纤突,呈冠状形态。病毒在CsCl中的浮密度为1.19～1.23 g/cm 3, 对热和氯仿敏感,耐酸,能抵抗1% 胰酶,无直接血凝性,经卵磷脂酶C处理后的病毒则能凝集鸡红细胞,能干扰新城疫病毒在鸡胚上的增殖。应用杂交瘤技术筛选出4 株抗H95株的阳性克隆,经Western blotting, 其中3 株单抗能识别54 kd 蛋白多肽,该条带也能与来自鸡传染性支气管炎病毒(IBV) M41 株的针对N 蛋白的单抗反应。中和试验表明, H95株与其它IBV 毒株在血清型上存在差异。上述研究结果初步表明,鸡传染性腺胃病的病原是冠状病毒科的成员,并且很可能是鸡传染性支气管炎(IB)中以腺胃病变为主要特征的一种新的致病病型。 相似文献
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以分离的犬瘟热病毒（CDV）株感染Vero细胞后提取病毒RNA，经反转录后，用犬瘟热病毒的1对引物扩增出融合蛋白融合区的基因片断。经序列分析显示：分离株CDV－YZ－0101与CDV－YZ－0103在核苷酸和氨基酸水平上同源性一致，与CDV－YZ－0102、CDV－A75／17、CDV－ONPPDV2、PDV1在核苷酸和氮基酸水平上的同源性分别为99.6%、97.9%、92.9％、98.9%、76.2%、93.3%和98.9%、97.9%、98.9%、83.0%、97.9%，表明分离株和相关毒株的融合区基因存在差别。 相似文献