用ELISA法检测鼠群中呼肠孤病毒抗体

本文用ELISA法检测小鼠呼肠孤病毒(Reo_3)抗体,并以美国Reo_3抗体药盒作验证。首先用110只SPF小鼠确定Reo_3抗体阳性界限为0.118。然后于1984年秋～1985年秋对开放饲养三个品系595只小鼠作了检测。结果表明,检出阳性率为7.9～34.4％,同时检测另5种病毒抗体(MHV,Sendai EHF,Ectromelia,LCM)发现Reo_3居第四位。证明本法用于检测Reo_3抗体特异性强,敏感性高,操作简便,重复性亦好,可供鼠群常规检测使用。     

用自身红细胞凝集试验检测肾综合征出血热病人全血中病毒特异性抗体

目的：验证微量快速自身血凝实验检测肾综合征出血热(HFRS)病人全血中病毒抗体的实用性。方法：采用直接玻片自身血凝试验检测临床诊断为HFRS病人全血中的特异性抗体，采用ELISA法作平行对照。结果：检测HFRS病人全血41份，自身血凝实验29例(70．73％)为阳性，ELISA法31例(75．61％)为阳性；用自身血凝实验检测90例正常人全血，其中89例不出现凝集。结论：应用自身血凝实验检测HFRS病人全血中病毒抗体，简便、微量、快速、特异性强，非常适合基层医疗单位使用。     

血清新型冠状病毒特异性抗体水平的检测及其动态变化规律

重症急性呼吸综合征(SARS)的病原体相继被不同实验室发现并确证为一种新型冠状病毒，又称为SARS病毒，已确定了病毒基因的一级结构和一些基因组特征，为利用分子免疫学手段研究和建立SARS的血清学诊断方法奠定了基础。我国军事医学科学院等单位已成功建立了检测SARS病毒抗体的ELISA方法，并开发出相应的检测试剂盒。本研究采用ELISA方法检测SARS患者和医务人员血清SARS病毒特异IgG抗体，观察SARS病毒抗体在患者和高危易感人群的产生规律和水平，为SARS的诊断及其流行传播特点的分析提供实验依据。     

61例HIV抗体筛查呈反应性蛋白印迹试验阴性样本核酸检测结果分析

<正>目前国内检测艾滋病病毒(HIV)抗体最常用的方法有酶联免疫吸附试验(ELISA)、快速检测(RT)、蛋白印迹试验(WB)等。ELISA试剂问世以来,性能不断改进,现有的第四代ELISA试剂在第三代基础上增加了p24抗原检测,从而实现了HIV抗原/抗体的同步检测~([1])。虽然WB是我国HIV的确证实验,但WB在早期感染者的检测中存在漏检风险~([2]),这严     

乙型脑炎病毒抗体捕获ELISA检测方法的初步建立

目的 建立检测乙型脑炎病毒抗体的抗体捕获ELISA方法.方法 以乙型脑炎病毒E蛋白抗原表位E39特异的单克隆抗体包被ELISA板,吸附乙型脑炎减毒活疫苗株SA14-14-2病毒粒子,再以吸附的病毒粒子捕获乙型脑炎病毒抗体,建立抗体捕获ELISA方法:同时与以乙型脑炎病毒细胞培养上清包被的间接ELISA方法进行对比,并检测临床血清样品105份.结果 间接ELISA方法背景无法消除,1:10、1:100、1:1000各稀释度的阳性血清与阴性血清吸光度(A)值相近,A阳性血清/阴性血清分别为1.02、0.99、1.13,均<2.1.而抗体捕获ELISA方法1:10、1:100稀释度的A阳性血清/阴性血清分别为3.57、2.94,均>2.1;1:1000稀释度的A阳性血清/阴性血清为1.42,<2.1,表明血清稀释度为1:100时可以显著区别乙型脑炎病毒感染的阳性血清与阴性血清,明显消除间接ELISA方法中背景过高的问题.抗体捕获ELISA方法检测105份临床血清样品,A阳性血清/阴性血清为0.257～0.321(0.262±0.050),均<2.1,为乙型脑炎病毒抗体阴性血清.结论 初步建立了乙型脑炎病毒抗体捕获ELISA方法,该方法特异性较高,对于建立乙型脑炎病毒群的快速鉴别诊断方法具有重要意义.     

无偿献血者标本血清学和核酸检测情况分析

目的:分析无偿献血者标本血清学检测和核酸检测情况,为制定血液筛查策略提供依据,降低输血传播性病原体漏检率。方法:分别用2种ELISA试剂对无偿献血者标本进行HBsAg、抗-HCV、HIV抗原/抗体检测,用荧光定性PCR方法对HBsAg、抗-HCV、HIV抗原/抗体ELISA检测结果阴性、0.5≤S/CO≤5.0、S/CO5.0的标本进行HBV-DNA、HCV-RNA、HIV-RNA检测。对190份HBsAg(-)/HBV-DNA(+)献血者标本进行化学发光补充实验。结果:187 791例血清学检测阴性的无偿献血者标本中检出1例HIV-RNA病毒,194例HBV-DNA病毒,未检出HCV RNA病毒。科华和罗氏核酸检测系统拆分阳性率和阳性检出率差异无统计学意义(P0.05)。HBsAg、抗-HCV、HIV抗原/抗体ELISA双试剂阳性(S/CO10.0)标本HBV-DNA、HCV-RAN和HIV-RNA阳性检出率分别为88.89%、84.62%和100%,0.5≤S/CO≤10.0 ELISA双试剂阳性标本的HBV-DNA、HCV-RAN和HIV-RNA阳性检出率分别为69.44%(25/36)、0和0;HBsAg ELISA检测双试剂阳性结果不同组间(S/CO10.0和0.7≤S/CO≤10.0)核酸阳性检出率差异无统计学意义(P0.05)。对194例HBsAg(-)/HBV-DNA(+)中的190例标本进行化学发光补充实验,检出1例HBsAg阳性,HBcAb阳性检出率为90.00%。结论:HBsAg ELISA检测后HBV输血风险仍然较高(103/10万)。NAT技术的应用,降低了血液病毒窗口期、OBI等输血残余风险。HBsAg、抗-HCV、HIV抗原/抗体ELISA阳性反应的HBV-DNA、HCV-RAN、HIV-RNA检出率与ELISA检测S/CO值的高低及2种ELISA试剂检测结果一致程度有一定关联。采用灵敏度高的血清学方法和核酸检测技术,可进一步降低输血传播病原体的漏检率,保障输血安全。     

狂犬病病毒基质蛋白的原核表达及其间接ELISA方法的建立

目的以原核表达的狂犬病病毒M蛋白作为检测抗原,建立间接ELISA方法用来检测狂犬病病毒抗体。方法为表达狂犬病病毒(RV)基质蛋白(M),采用RT-PCR方法从狂犬病病毒Flury-LEP株中扩增RV基质蛋白基因,双酶切后定向克隆至原核表达载体pET-32a(+),构建重组质粒pET-M。将重组质粒pET-M转化至宿主菌E.coli Rosetta中进行表达。SDS-PAGE和Western blot分析确定蛋白表达量和特异性。用纯化的重组M蛋白作为包被抗原建立检测犬RV抗体的间接ELISA方法,通过优化反应条件,确定抗原最佳包被量、血清的最佳稀释度、Protein A-HRP的最佳稀释度。结果经PCR、双酶切及测序鉴定,重组质粒pET-M构建成功,将重组质粒进行转化后诱导表达,经SDS-PAGE电泳分析得到高效表达的M蛋白,重组蛋白可被RV阳性血清特异性识别,表明基质蛋白具有良好的反应原性。用表达的狂犬病病毒M蛋白建立了检测RV抗体的间接ELISA方法,用该间接ELISA方法与以狂犬病病毒作为诊断抗原的商品化ELISA试剂盒分别对93份临床血清样品进行检测,结果两者的符合率为89.2%。结论用原核表达的重组M蛋白作为包被抗原建立的间接ELISA方法可用做检测犬RV抗体水平的参考。     

胶体金免疫层析检测犬、猫抗狂犬病病毒IgG抗体的研究

目的建立检测犬、猫抗狂犬病病毒(RV)IgG抗体的胶体金免疫层析方法。方法采用柠檬酸三钠还原法制备胶体金用以标记SPA,同时将重组RVN蛋白、抗SPA抗体分别包被至硝酸纤维素膜的检测线与质控线上,制备一种检测犬、猫抗RVIgG抗体的胶体金检测卡,进行了特异性和灵敏度试验,并与ELISA同时检测临床样品、统计结果。结果 GICA试纸条检测灵敏度为0.5IU/mL,与犬瘟热病毒、犬细小病毒等阳性血清无交叉反应,并与ELISA相比,两者的符合率为94.6%。结论成功建立了检测犬、猫抗RVIgG抗体的通用型胶体金免疫层析方法 ,该方法灵敏度高,特异性强,检测速度快,操作简便,可广泛应用于基层。     

狂犬病病毒P基因的原核表达及间接ELISA方法的应用

目的以狂犬病病毒P蛋白作为检测抗原,用间接ELISA方法检测狂犬病病毒抗体。方法根据GenBank发表的狂犬病病毒(Rabies Virus,RV)LEP-Flury株的基因序列设计引物,通过RT-PCR扩增出P基因的全长序列,克隆于pGM-T载体中,获得重组质粒pGM-T-P,将重组质粒用限制性内切酶NotI和EcoRI进行双酶切,酶切产物定向克隆于原核表达载体pET-32a(+)中,构建原核重组表达质粒pET-32a-P,阳性重组质粒转化原核表达宿主菌BL21(DE3),用IPTG诱导表达。SDS-PAGE和Western-blot分析确定蛋白表达量和特异性。用纯化的蛋白作为诊断抗原,通过对反应条件的优化,初步将间接ELISA方法应用于狂犬病病毒抗体的检测中。结果扩增RV P基因,构建了克隆质粒pGM-T-P、原核表达质粒pET-32a-P,高效表达了主要以可溶性形式存在的P蛋白,并能与RV阳性血清发生特异性反应。用表达的狂犬病病毒重组P蛋白建立了用于RV抗体检测的间接ELISA方法。结论成功表达了磷蛋白,用其作为固化抗原以间接ELISA方法检测RV抗体。     

传染性非典型肺炎的血清学诊断研究

目的 评估传染性非典型肺炎(世界卫生组织又称严重急性呼吸综合征，SARS)血清病毒特异性抗体检测在SARS诊断中的实用价值，了解免疫荧光抗体法(IFA)和酶联免疫吸附法(ELISA)对SARS病毒特异性抗体检测结果的一致性程度。方法 用IFA和ELISA检测267例不同病程SARS患和132例对照组血清SARS病毒特异性抗体，以敏感度、特异度、阳性预测值(17PV)、阴性预测值(NPV)和准确度评价其诊断价值，并以Kappa值评价两种检测方法结果的一致性。结果 以IFA检测的血清特异性IgM类和IgG类抗体阳性率在病程第11天明显增高，病程≥11天，IgM类抗体诊断SARS的敏感度为65．6％，特异度100．0％，PPV 100．0％，NPV 71．0％，准确度81．3％；IgG类抗体则分别为敏感度91．1％，特异度97．0％，PPV 97．3％，NPV 90．1％，准确度93．8％。以ELISA方法所测结果与IFA结果相仿。对IFA和ELISA法检测的一致性检验示Kappa值分别为0．640和0．779。结论 血清病毒特异性抗体在SARS发病10天以上阳性率高，抗体检测有助于确立发病10天以上SARS的血清学诊断。IFA和ELISA检测SARS病毒抗体的一致性较好。     

Interferon inhibits Sendai virus-induced cell fusion: an effect on cell membrane fluidity.

Interferon can affect several cellular functions, in addition to its antiviral activity. We report here that pretreatment of human cells with homologous interferon significantly inhibits cell fusion induced by Sendai virus and that this refractory state is accompanied by a decrease in cell plasma membrane fluidity. Multinucleate cell formation induced by beta-propiolactone-inactivated Sendai virus in human fibroblast cells (a system in which fusion results from an interaction of the viral glycoprotein with the cell membrane) was inhibited by more than 90% after addition of human interferon for 18-24 hr. This inhibition could be neutralized by antiserum to interferon. Furthermore, inhibitor studies with cycloheximide and actinomycin D clearly indicated that synthesis of protein and RNA is necessary to establish the resistant state. To determine whether the inhibition of Sendai virus-induced cell fusion resulted from interferon-induced changes at the cell plasma membrane, experiments were carried out using the fluorescence probe 1,6-diphenyl-1,3,5-hexatriene, which is capable of sensing molecular motions in the hydrocarbon core of the bilayer structure. A significant decrease in the membrane fluidity of interferon-treated cells was observed. It is likely, therefore, that the inhibitory effect on Sendai virus-induced cell fusion observed in interferon-treated cells results from an increased rigidity of the target cell membrane.     

Cell fusion induced by scrapie and Creutzfeldt-Jakob virus-infected brain preparations.

Cell fusion was induced by brain extracts containing the scrapie virus and the virus of Creutzfeldt-Jakob disease. The assay involved quantitation of colony-forming ability in a double selection system, strandardized against fusion induced by Sendai virus. Correlation between the logarithm of virus dilution and the hybrid colony number gave similar curves for scrapie virus and Sendai virus. Fusion induction may explain some aspects of pathogenesis in these diseases and provide a potential in vitro assay.     

Purification of the fusion protein of Sendai virus: analysis of the NH2-terminal sequence generated during precursor activation.

The two glycoproteins of Sendai virus, the hemagglutinin-neuraminidase and the fusion protein (F), were separated and purified by affinity chromatography on a Lens culinaris lectin-Sepharose column. F was shown to consist of two disulfide-bonded glycopolypeptide chains, F1 and F2, of molecular weights 51,000 and 11,000, each of which contained 15% carbohydrate by weight. Amino-terminal sequence analysis showed that F2 was blocked and that the hydrophobic sequence NH2-Phe-Phe-Gly-Ala-Val-Ile-Gly-Ile-Ile-Ala-Leu-Gly-Pro-Ala-Thr- was at the amino terminus of F1. This sequence shows identity at six positions with the hydrophobic amino-terminal sequence of the smaller glycopolypeptide chain, HA2, of the hemagglutinin of influenza virus. Both F1 and HA2 are formed by proteolytic cleavage of precursor glycoproteins (Fo, Sendai virus; HAo, influenza virus). Since these cleavages confer infectivity upon both Sendai and influenza viruses and the ability to induce cell-to-cell fusion upon Sendai virus, the hydrophobic NH2-terminal sequences on F1 and HA2 may play a role in fusion of viral and host-cell membranes.     

Protection against lethal Sendai virus infection by in vivo priming of virus-specific cytotoxic T lymphocytes with a free synthetic peptide.

The only peptide of Sendai virus that is recognized by cytotoxic T lymphocytes (CTL) in B6 mice was found with (i) the use of recombinant vaccinia virus constructs containing separate genes of Sendai virus and (ii) a set of overlapping peptides completely spanning the identified nucleoprotein (NP) gene product. This immunodominant NP peptide is recognized by Sendai virus-specific CTL that are known to have therapeutic effects in vivo. By subcutaneous immunization, this peptide induced Sendai virus and NP peptide-specific CTL memory responses in vivo. Most importantly, mice that had been immunized with this peptide were protected against a lethal virus dose, indicating that viral peptides can be used as antiviral T-cell vaccines. The induction of T-cell memory by free peptide immunization potentially has wide applicability in biology and medicine, including protection against infectious disease.     

Sendai virus utilizes specific sialyloligosaccharides as host cell receptor determinants.

Purified sialyltransferases (CMP-N-acetyl-neuraminate:D-galactosyl-glycoprotein N-acetylneuraminyl-transferase, EC 2.4.99.1) in conjunction with neuraminidase (acylneuraminyl hydrolase, EC 3.2.1.18) were used to produce cell surface sialyloligosaccharides of defined sequence to investigate their role in paramyxovirus infection of host cells. Infection of Madin-Darby bovine kidney cells by Sendai virus was monitored by hemagglutination titer of the virus produced and by changes in morphological characteristics. By either criterion, treatment of the cells with Vibrio cholerae neuraminidase to remove cell surface sialic acids rendered them resistant to infection by Sendai virus. Endogenous replacement of receptors by the cell occurred slowly but supported maximal levels of infection within 6 hr. In contrast, sialylation during a 20-min incubation with CMP-sialic acid and beta-galactoside alpha 2,3-sialytransferase restored full susceptibility to infection. This enzyme elaborates the NeuAc alpha 2,3Gal beta 1,3GalNAc (NeuAc, N-acetylneuraminic acid) sequence on glycoproteins and glycolipids. No restoration of infectivity was observed when neuraminidase-treated cells were sialylated by using beta-galactoside alpha 2,6-sialytransferase, which elaborates the NeuAc-alpha 2,6Gal beta 1,4GlcNAc sequence. These results suggest that sialyloligosaccharide receptor determinants of defined sequence are required for Sendai virus infection of host cells.     

A QUANTITATIVE COMPARISON OF FORMATION OF SPONTANEOUS AND VIRUS-PRODUCED VIABLE HYBRIDS

Ultraviolet-inactivated Sendai virus used in conjunction with a selective system reproducibly gives high yields of viable hybrid cell lines. With two different crosses, the frequency of hybrid colonies obtained after virus treatment was found to be 100 times greater than the frequency of spontaneous hybrids, and this increase was found to show little variation between 33 and 1000 hemagglutinating units of virus. No differences have been found between the properties of hybrids obtained after Sendai treatment and those obtained from untreated mixed cultures of parental cells.     

Production of the chemokines monocyte chemotactic protein-1, regulated on activation normal T cell expressed and secreted protein, growth-related oncogene, and interferon-gamma-inducible protein-10 is induced by the Sendai virus in human and rat testicular cells

Several viruses infect the testis, inducing inflammation, which may lead to infertility. In this study we investigated the production in rat and human testicular cells exposed to the Sendai virus of several chemokines that play a major role in inflammatory processes. Exposure of rat testicular macrophages and Sertoli, Leydig, and peritubular cells to the Sendai virus led to the production of mRNA and protein for monocyte chemotactic protein-1 (MCP-1), regulated on activation normal T cell expressed and secreted protein, growth-related oncogene-alpha, and interferon-gamma-inducible protein-10. In rat peritubular cells exposed to the Sendai virus, MCP-1 production was time and dose dependent. In contrast, rat germ cells did not produce these chemokines. Chemokine synthesis was detected in human Leydig cells exposed to the Sendai virus, but not in human total germ cells, suggesting that rats and humans display similar responses in terms of chemokine production. MCP-1, regulated on activation normal T cell expressed and secreted protein, growth-related oncogene-alpha, and interferon-gamma-inducible protein-10 have been reported to be chemoattractants for a large variety of leukocytes. The ability of the Sendai virus to induce chemokine production in somatic cells (mostly peritubular and Leydig cells) may therefore increase the recruitment of leukocytes to sites of infection.     

An alternative route of infection for viruses: entry by means of the asialoglycoprotein receptor of a Sendai virus mutant lacking its attachment protein.

During the first stage of infection, the paramyxovirus Sendai virus attaches to host cells by recognizing specific receptors on the cell surface. Productive virus-cell interactions result in membrane fusion between the viral envelope and the cell surface membrane. It has recently been shown that the ganglioside GD1a and its more complex homologs GT1b and GQ1b are cell surface receptors for Sendai virus. We report in this paper that the temperature-sensitive mutant ts271 of the Enders strain of Sendai virus lacks the viral attachment protein HN and the biological activities of hemagglutination and sialidase activity associated with it when the virus is grown at 38 degrees C. This HN- virus was unable to infect or agglutinate conventional host cells that contained receptor gangliosides and were readily infected by the parental wild-type virus. The HN- virus did, however, attach to and infect Hep G2 cells, a line of hepatoma cells that retains the asialoglycoprotein receptor (ASGP-R) upon continuous culture. This receptor is a mammalian lectin that recognizes galactose- or N-acetylgalactosamine-terminated proteins. In accordance with the known properties of this receptor, infection by the HN- virus was abolished by treatment of Hep G2 cells with sialidase, by the presence of Ca2+ chelators, and by competition with N-acetylgalactosamine, asialoorosomucoid, and antibody to the receptor. F, the only glycoprotein on the HN- virus, was shown to compete with the galactose-terminated protein asialoorosomucoid for the ASGP-R. The ability of the HN- virus to cause cell-cell fusion of Hep G2 cells indicated that attachment of this virus to the ASGP-R still permitted viral entry by its usual mode--i.e., membrane fusion at the cell surface. These results open up the possibility that enveloped viruses, which contain glycosylated proteins or lipids, may make use of naturally occurring lectins in addition to their normal receptors as a means of attachment to host cells.     

Sequential virus infections, bacterial superinfections, and fibrogenesis

Parainfluenza 1 (Sendai) and influenza A virus pneumonitis cause severe lung damage, which, upon resolution, is followed by persistent alveolitis and parenchymal changes characterized by patchy consolidation and collagen deposition in the affected areas. To determine whether these long-term sequelae of the virus pneumonias are cumulative, mice were infected by aerosol inhalation with Sendai virus, influenza A virus, or Sendai followed 30 days later by influenza virus infection. At 90 days after the initial infection, mice were killed for assay of long-term parenchymal changes as quantitated lung hydroxyproline (Hpr) content, morphometric analysis, and total and differential lavage cell counts. Sendai virus infection did not alter the proliferation of influenza virus in the lungs as quantitated by infectious virus titers on Day 1, 3, 5, 7, 9, and 11 of influenza infection. At Day 90, lung Hpr content was cumulative in dual-infected mice, with a concomitant increase in the persistent alveolitis. To determine whether bacterial infections played a similar role in these long-term pulmonary sequelae, mice were infected by aerosol inhalation with either Staphylococcus aureus or Klebsiella pneumoniae or, during the course of influenza virus infection, superinfected with each of the bacteria. Sixty days after infection with K. pneumoniae alone, lung Hpr levels were significantly increased over those in noninfected control mice. Infection with S. aureus had no effect on the quantitated parameters of long-term lung damage. In influenza-infected mice superinfected with K. pneumoniae, lung Hpr content was significantly increased over that of S. aureus did not elevate any quantitated parameter of lung damage when compared with the virus alone.(ABSTRACT TRUNCATED AT 250 WORDS)