SARS patients-derived human recombinant antibodies to S and M proteins efficiently neutralize SARS-coronavirus infectivity

Objective To develop a specific SARS virus-targeted antibody preparation for emergent prophylaxis and treatment of SARS virus infection. Methods By using phage display technology, we constructed a naive antibody library from convalescent SARS patient lymphocytes. To obtain the neutralizing antibody to SARS virus surface proteins, the library panning procedure was performed on purified SARS virions and the specific Fab antibody clones were enriched by four rounds of repeated panning procedure and screened by highthroughput selection. The selected Fab antibodies expressed in the periplasma of E. coli were soluble and further purified and tested for their binding properties and antiviral function to SARS virus. The functional Fab antibodies were converted to full human IgG antibodies with recombinant baculovirus/insect cell systems and their neutralizing activities were further determined. Results After four rounds of the panning, a number of SARS-CoV virus-targeted human recombinant Fab antibodies were isolated from the SARS patient antibody library. Most of these were identified to recognize both natural and recombinant SARS spike （S） proteins, two Fab antibodies were specific for the virus membrane （M） protein, only one bound to SARS-CoV nucleocapsid protein. The SARS-CoV S and M protein-targeted Fab or IgG antibodies showed significant neutralizing activities in cytopathic effect （CPE） inhibition neutralization test, these antibodies were able to completely neutralize the SARS virus and protect the Vero cells from CPE after virus infection. However, the N protein-targeted Fab or IgG antibodies failed to neutralize the virus. In addition, the SARS N protein-targeted human Fab antibody reacted with the denatured N proteins, whereas none of the S and M protein specific neutralizing antibodies did. These results suggested that the S and M protein-specific neutralizing antibodies could recognize conformational epitopes which might be involved in the binding of virions to cellular receptors and the fusion activity of the virus Conclusion The SARS-CoV spike protein and membrane proteins are able to elicite efficient neutralizing antibodies in SARS patients. The neutralizing antibodies we generated in this study may be more promising candidates for prophylaxis and treatment of SARS infection.     

严重急性呼吸综合征冠状病毒2假病毒的制备及验证

目的 建立严重急性呼吸综合征冠状病毒2（SARS-CoV-2）假病毒（SARS-CoV-2 pps）的制备方法。方法 设计、合成序列优化的SARS-CoV-2刺突蛋白（S）基因,构建表达质粒,转染293T细胞,用免疫荧光检测S蛋白的表达;将该质粒与基于慢病毒基因骨架的含增强绿色荧光蛋白（EGFP）报告基因的假病毒包装质粒共转染293T细胞,收集细胞培养上清,感染Vero E6和Huh7细胞,观察细胞内EGFP的表达;将制备的SARS-CoV-2 pps感染Vero E6细胞,检测膜融合抑制剂氯喹和盐酸阿比朵尔、SARS-CoV-2 S1蛋白单克隆抗体及新型冠状病毒肺炎患者恢复期血清对假病毒感染性的影响。结果 构建的SARS-CoV-2 S质粒转染的293T细胞可与S1蛋白单克隆抗体及新型冠状病毒肺炎患者恢复期血清反应。SARS-CoV-2 S质粒与HIV假病毒包装质粒共转染293T细胞的上清加入Vero E6细胞和Huh7细胞36 h和72 h后可分别观察到细胞内表达的EGFP,EGFP阳性的Huh7细胞数量明显多于Vero E6细胞。2种膜融合抑制剂、1株人源S1单克隆抗体及2份新型冠状病毒肺炎患者恢复期血清均可有效抑制SARS-CoV-2 pps对Vero E6细胞的感染（P均<0.01）。结论 成功制备了SARS-CoV-2 pps,其可用于后续抗SARS-CoV-2药物筛选与疫苗评价。     

鼠抗SARS病毒X4蛋白单克隆抗体的制备及鉴定

目的:制备SARS病毒X4蛋白的单克隆抗体,探讨X4蛋白的结构和功能,以及临床应用的价值.方法:以重组SARS病毒X4蛋白为免疫原,免疫Balb/c小鼠,取免疫小鼠的脾细胞和同系小鼠的骨髓瘤细胞进行常规融合, 通过间接ELISA的筛选和有限稀释克隆化,获得鼠抗SARS病毒X4蛋白单克隆抗体的杂交瘤细胞株,通过ELISA,Western blot和免疫荧光实验等方法鉴定其特性.结果:成功地建立了3株稳定分泌抗X4蛋白的单克隆抗体杂交瘤细胞株,分别命名为8A5,8H6和4A2.3株单克隆抗体的免疫球蛋白亚类均为IgG2a.通过ELISA, Western blot等方法的鉴定,抗X4蛋白的单克隆抗体能与X4蛋白发生特异性反应.免疫荧光实验的结果表明,X4蛋白的单克隆抗体能与SARS-病毒感染的Vero E6 细胞发生特异性结合.结论:获得了特异性识别SARS病毒X4蛋白的单克隆抗体,为SARS病毒X4蛋白的生物学功能研究奠定了基础.     

质粒表达型siRNA对SARS-CoV复制与感染干扰的初步研究

目的构建针对SARS-CoV的特异性siRNA质粒,利用RNA干扰技术抑制该病毒复制与感染.方法根据SARS-CoV的全长基因序列,以4个不同的部位为靶点,分别设计、合成含有19 nt干扰序列的一段寡核苷酸,将两两互补的寡核苷酸经退火后所形成的序列克隆到pSilencer 3.1-H1载体中,构建表达siRNA的质粒.采用脂质体法将质粒转染Vero E6细胞,经潮霉素抗性筛选后,再对稳定表达的细胞进行细胞病变、病毒空斑形成和MTT实验,以观察干扰效应.结果对所构建的质粒分别测序,确定其含有siRNA的序列与预期的特异性干扰序列一致.用不同浓度的SARS-CoV感染转染质粒后的细胞,与阴性对照相比,其细胞病变减轻、活细胞显著增加,病毒空斑明显减少.结论利用RNA干扰能有效的抑制SARS-CoV在细胞中的复制,并对细胞有保护作用,为预防、治疗SARS提供了新的思路和方法.     

SARS病毒S蛋白的原核表达与DNA疫苗的构建

目的 探讨SARS冠状病毒的刺突(spike,S)蛋白的免疫学特性,以及S蛋白作为SARS-CoV病毒疫苗组分的可行性。方法 将S蛋白基因分段克隆入原核表达载体pET-15b,并在大肠杆菌中表达,经过亲和层析得到纯化的重组蛋白rS_a和rS_b;将全长S基因克隆入真核分泌表达载体pSecTagB,得到重组DNA疫苗pSecS,免疫小鼠,得到SAS-CoVS蛋白抗血清。然后用纯化的重组蛋白rS_a和rS_b建立的SARS-CoVS抗体ELISA检测技术研究所构建的S-DNA疫苗的免疫效果。结果 分段的重组蛋白rS_a和rS_b在大肠杆菌中均以可溶性形式得到高效表达,并能与SARS确诊病人血清以及pSecS免疫鼠血清发生特异性抗原抗体反应,原核表达的重组分段S蛋白具有SARS-CoVS蛋白相似的抗原性。结论 原核表达的两段重组S蛋白有可能作为抗原组分用于临床SARS-CoV检测中;所构建的SARS-CoV的S基因核酸疫苗能在小鼠体内产生特异性抗体,这为进一步SARSDNA疫苗的研制提供一定的借鉴作用。     

Tat融合蛋白表达载体TAT-OCT4的克隆化及蛋白表达研究

目的构建重组表达载体TAT-OCT4,在E.coli BL21中高效表达并纯化融合蛋白。为进一步通过蛋白转导方式诱导多能干细胞提供物质基础。方法经RT-PCR获得编码人OCT4的全基因序列,连接到原核表达载体TAT-V2上,得到重组表达载体TAT-OCT4,转化大肠埃希菌,异丙基-β-D-硫代吡喃半乳糖苷（isopropylβ-D-thiogalactopyranoside,IPTG）诱导TAT-OCT4融合蛋白的表达。表达产物用SDS-PAGE鉴定,亲和层析柱纯化融合蛋白,并应用Western Blot检测蛋白的特异性,应用免疫荧光检测融合蛋白转导人皮肤成纤维（human skin fibroblasts,HSF）细胞的效果。结果成功构建了TAT-OCT4融合蛋白的原核表达载体,在诱导下获得了高效表达并纯化了融合蛋白,Western Blot鉴定正确。免疫荧光提示融合蛋白可快速转导入HSF细胞内。结论 TAT-OCT4融合蛋白可以安全,高效地转导入HSF细胞中。     

Efficient and quick inactivation of SARS coronavirus and other microbes exposed to the surfaces of some metal catalysts

To study the two metal catalysts Ag/Al2O3 and Cu/Al2O3 that interdict the transmission pathway for SARS and other respiratory infectious diseases. Methods Two metal catalysts Ag/Al2O3 and Cu/Al2O3 were pressed into wafers.One hundred μL 10^6 TCID50/mL SARS-CoV, 100μL 10^6 PFU/mL recombinant baculovirus expressing hamster‘s prion protein (haPrP) protein and roughly 10^6 E. coli were slowly dropped onto the surfaces of the catalyst wafers and exposed for 5 and 20min, respectively. After eluted from the surfaces of wafers, the infectivity of viruses and propagation of bacteria were measured. The expression of PrP protein was determined by Western blot. The morphological changes of bacteria were observed by electronic microscopy. Results After exposure to the catalysts surfaces for 5 and 20 rain, the infectivity of SARS-CoV in Vero cells and baculovirus in Sf9 cells dropped down to a very low and undetectable level, and no colony was detected using bacteria culture method. The expression of haPrP protein reduced to 21.8% in the preparation of Sf9 cells infected with recombinant baculovirus exposed for 5 min and was undetectable exposed for 20 min. Bacterial membranes seemed to be cracked and the cytoplasm seemed to be effluent from cell bodies. Conclusion Exposures to the surfaces of Ag/Al2O3 and Cu/Al2O3 destroy the replication and propagation abilities of SARS-CoV, baculovirus and E. coil Inactivation ability of metal catalysts needs to interact with air, utilizing oxygen molecules in air. Efficiently killing viruses and bacteria on the surfaces of the two metal catalysts has a promising potential for air-disinfection in hospitals, communities, and households.     

SARS病毒S蛋白的原核表达与DNA疫苗的构建

目的探讨SARS冠状病毒的刺突(spike，S)蛋白的免疫学特性，以及S蛋白作为SARS—CoV病毒疫苗组分的可行性。方法将S蛋白基因分段克隆入原核表达载体pET—15b，并在大肠杆菌中表达，经过亲和层析得到纯化的重组蛋白rSa和rSb；将全长S基因克隆入真核分泌表达载体pSecTagB，得到重组DNA疫苗pSecS，免疫小鼠，得到SAS—CoV S蛋白抗血清。然后用纯化的重组蛋白rSa和rSb建立的SARS—CoV S抗体ELISA检测技术研究所构建的S-DNA疫苗的免疫效果。结果分段的重组蛋白rSa和rSb在大肠杆菌中均以可溶性形式得到高效表达，并能与SARS确诊病人血清以及pSecS免疫鼠血清发生特异性抗原抗体反应，原核表达的重组分段S蛋白具有SARS—CoV S蛋白相似的抗原性。结论原核表达的两段重组S蛋白有可能作为抗原组分用于临床SARS—CoV检测中；所构建的SARS—CoV的S基因核酸疫苗能在小鼠体内产生特异性抗体，这为进一步SARS DNA疫苗的研制提供一定的借鉴作用。     

SARS冠状病毒M蛋白B细胞抗原表位的原核表达与抗原活性检测

目的从SARS冠状病毒M蛋白的线性重叠肽链文库中筛选出5个B细胞抗原表位,通过构建原核表达载体,表达抗原表位融合蛋白,并检测其抗原活性.方法应用大肠杆菌高频密码子设计引物,通过PCR方法合成编码SARS冠状病毒M蛋白5个抗原表位(MKY1、MKY2、MKY3、MKY4和MKY5)的DNA片段,经克隆和测序分析,亚克隆至表达载体pET-CKS,转化大肠杆菌BL21;阳性菌株经IPTG诱导,SDS-PAGE分析;大量诱导表达抗原表位融合蛋白,亲和层析予以纯化;Western检测SARS病人阳性血清对融合蛋白的识别.结果成功构建SARS冠状病毒M蛋白抗原表位的表达载体,在大肠杆菌BL21中表达,融合蛋白表达量达到细菌总蛋白30%,经亲和层析纯化,融合蛋白可被SARS病人抗血清识别.结论原核表达的抗原表位融合蛋白具有良好的抗原活性,为下一步进行SARS冠状病毒诊断试剂盒的开发研究奠定基础.     

SARS冠状病毒S蛋白多价核酸疫苗的构建和免疫学原性

目的构建以SARS冠状病毒（severe acutere spiratory syndrome coronavlrus,SARs．c0V）S蛋白3个保守片段基因的组合为抗原基因DNA疫苗,采用肌肉注射的方法接种小鼠后观察机体产生免疫应答的情况。方法将人工合成的S蛋白3个保守片段基因组合（称为Sa）克隆至真核表达载体pcDNA3、1（-）,随之将重组质粒进行小鼠肌肉免疫,定期检测血清中抗SARS—CoV的病毒特异性抗体水平,流式细胞仪观察其淋巴细胞表型变化,PCR法检测质粒分布,免疫组化检测抗原表达。结果疫苗注射后15d就能在血清中检测出病毒特异性抗体,并且疫苗能在机体中持续表达抗原引发机体持续的免疫应答,直到注射后45d免疫应答都不见减弱;以CTLT淋巴细胞为主的CD8＋T淋巴细胞的百分比含量增加极显著,引起强大的体液免疫和细胞免疫;而空载体质粒对照组未检测出明显的特异性免疫应答。结论以S蛋白3个保守片段基因组合为抗原基因的DNA疫苗通过肌注能诱导小鼠针对SARS病毒强大的免疫应答。     

抗SARS冠状病毒S1蛋白N端249至667的单克隆抗体的制备与鉴定

目的在获得了具有免疫原性的SARS冠状病毒S1蛋白片段的基础上,制备和鉴定特异性抗该段S1蛋白单克隆抗体(mAb)。方法原核表达含S蛋白受体结合区的SARS冠状病毒S1蛋白片段S1c(N端249-667氨基酸残基),其免疫原性经SARS病人恢复期血清鉴定后免疫BALB/c小鼠,按常规方法制备单克隆抗体,并采用ELISA间接法、免疫荧光和免疫印迹进行筛选和鉴定。结果筛选出3株特异性针对SARS冠状病毒S1蛋白N端249-667的mAb杂交瘤细胞株,IgG亚类鉴定1株为IgG1,2株为IgG2a,经免疫荧光鉴定与人冠状病毒株229E和OC43无交叉反应。结论获得3株抗SARS冠状病毒S蛋白受体结合区特异性单克隆抗体,为建立新的SARS冠状病毒检测方法的和进一步研究S蛋白的功能奠定了基础。     

抗SARS冠状病毒S1蛋白N端249至667的单克隆抗体的制备与鉴定

目的 在获得了具有免疫原性的SARS冠状病毒S1蛋白片段的基础上，制备和鉴定特异性抗该段S1蛋白单克隆抗体(mAb)。方法 原核表达含S蛋白受体结合区的SARS冠状病毒S1蛋白片段Slc(N端249-667氨基酸残基)，其免疫原性经SARS病人恢复期血清鉴定后免疫BALB／c小鼠，按常规方法制备单克隆抗体，并采用ELISA间接法、免疫荧光和免疫印迹进行筛选和鉴定。结果 筛选出3株特异性针对SARS冠状病毒S1蛋白N端249-667的mAb杂交瘤细胞株，IgG亚类鉴定1株为IgG1，2株为IgG2a，经免疫荧光鉴定与人冠状病毒株229E和OC43无交叉反应。结论 获得3株抗SARS冠状病毒S蛋白受体结合区特异性单克隆抗体。为建立新的SARS冠状病毒检测方法的和进一步研究S蛋白的功能奠定了基础。     

Pathogenesis of severe acute respiratory syndrome

Severe acute respiratory syndrome （SARS） first emerged in Guangdong province, China in November 2002. During the following 3 months, it spread rapidly across the world, resulting in approximately 800 deaths. In 2004, subsequent sporadic cases emerged in Singapore and China. A novel coronavirus, SARS-CoV, was identified as the etiological agent of SARS.1＇2 This virus belongs to a family of large, positive, single-stranded RNA viruses. Nevertheless, genomic characterization shows that the SARS-CoV is only moderately related to other known coronaviruses.3 In contrast with previously described coronaviruses, SARS-CoV infection typically causes severe symptoms related to the lower respiratory tract. The SARS-CoV genome includes 14 putative open reading frames encoding 28 potential proteins, and the functions of many of these proteins are not known.4 A number of complete and partial autopsies of SARS patients have been reported since the first outbreak in 2003. The predominant pathological finding in these cases was diffuse alveolar damage （DAD）, This severe pulmonary injury of SARS patients is caused both by5 direct viral effects and immunopathogenetic factors, Many important aspects of the pathogenesis of SARS have not yet been fully clarified. In this article, we summarize the most important mechanisms involved in the complex pathogenesis of SARS, including clinical characters, host and receptors, immune system response and genetic factors.     

survivin蛋白的原核高效、可溶性表达及其抗体在恶性肿瘤早期诊断中的应用

目的 实现重组survivin在大肠杆菌中的高效、可溶性表达,检测健康人和肿瘤患者血清中anti-survivin并探讨其在肿瘤早期诊断中的应用价值.方法 重组PET32a-survivin质粒转化BL21感受态细胞,IPTG诱导表达8 h后对表达产物行溶菌酶处理、冻融及超声处理,SDS-PAGE及Western blot鉴定后用镍离子金属螯合层析柱纯化.建立基于重组融合蛋白的survivin特异性抗体的检测方法,对300份健康血清、144份肿瘤血清anti-survivin进行了检测,并将anti-sur-vivin与肝癌、肠癌、胰腺癌、卵巢癌患者中AFP、CEA、CA199、CA125等肿瘤标志物进行了联合分析.结果 重组survivin融合蛋白在BL21中获得了高效、可溶性表达,表达量约占菌体总蛋白的30%.建立了检测survivin抗体的间接ELISA方法,anti-survivin在不同的肿瘤血清中均有表达,阳性率各不相同.结论 成功的实现了survivin蛋白在大肠杆菌中的高效、可溶性表达;结果提示在肿瘤的辅助诊断中,anti-survivin与现有的肿瘤标志物CA199、CEA、CA-199和CA-125联合检测,可以互相补充其不足,提高肿瘤的诊断率.     

新基因ZNFD的克隆及其多克隆抗体的制备

目的:PCR扩增得到新基因ZNFD(Znf domain containing protein),构建pET32a-ZNFD原核表达载体,诱导蛋白表达及制备多克隆抗体。方法:通过PCR的方法克隆新基因ZNFD,选取部分抗原免疫原性较高的部分ORF序列,克隆到原核表达载体pET32a上,利用大肠杆菌Rosetta-gami(DE3)表达系统表达ZNFD融合蛋白。纯化目的蛋白免疫家兔,制备多克隆抗体。通过琼脂糖双向扩散实验和Western blot鉴定其效价和特异性。结果:经测序鉴定已成功克隆ZNFD基因。通过构建原核表达载体pET32a-ZNFD,在大肠杆菌Rosetta-gami(DE3)中使用IPTG诱导表达,得到相对分子质量约为45 kD的融合蛋白。纯化蛋白免疫家兔,制备的多克隆抗体具有较强的免疫特异性。结论:得到纯化的ZNFD蛋白,制备的多克隆抗体达到了一定的效价,且具有高特异性,为进一步研究ZNFD的功能奠定了实验基础。     

Molecular biological analysis of genotyping and phylogeny of severe acute respiratory syndrome associated coronavirus

Background SARS-CoV is the causative agent of severe acute respiratory syndrome (SARS) which has been associated with outbreaks of SARS in Guangdong, Hong Kong and Beijing of China, and other regions worldwide. SARS-CoV from human has shown some variations but its origin is still unknown. The genotyping and phylogeny of SARS-CoV were analyzed and reported in this paper.Methods Full or partial genomes of 44 SARS-CoV strains were collected from GenBank. The genotype, single nucleotide polymorphism and phylogeny of these SARS-CoV strains were analyzed by molecular biological, bioinformatic and epidemiological methods.Results There were 188 point mutations in the 33 virus full genomes with the counts of mutation mounting to 297. Further analysis was carried out among 36 of 188 loci with more than two times of mutation. All the 36 mutation loci occurred in coding sequences and 22 loci were non-synonymous. The gene mutation rates of replicase 1AB, S2 domain of spike glycoprotein and nucleocapsid protein were lower (0.079%-0.103%). There were 4 mutation loci in S1 domain of spike glycoprotein. The gene mutation rate of ORF10 was the highest (3. 333% ) with 4 mutation loci in this small domain(120 bp) and 3 of 4 loci related to deletion mutation. By bioinformatics processing and analysis, the nucleotides at 7 loci of genome (T:T:A:G:T:C:T/C:G:G:A:C:T:C) can classify SARS-CoV into two types. Therefore a novel definition is put forward that according to these 7 loci of mutation, 40 strains of SARS-CoV in GenBank can be grouped into two genotypes, T:T:A:G:T:C:T and C:G:G:A:C:T:C, and named as SARS-CoV Yexin genotype and Xiaohong genotype. The two genotypes can be further divided into some sub-genotypes. These genotypes can also be approved by phylogenetic tree of three levels of 44 loci of mutation, spike glycoprotein gene and complete genome sequence. Compared to various strains among SARS-CoV Yexin genotype and Xiaohong genotype, GD01 strain of Yexin genotype is more closely related to SARS-CoV like-virus from animals.Conclusion The results mentioned above suggest that SARS-CoV is responding to host immunological pressures and experiencing variation which provide clues, information and evidence of molecular bioloav for the clinical patholocly, vaccine developing and epidemic investigation.     

重组日本血吸虫14-3-3蛋白的纯化和免疫特性分析

目的：纯化日本血吸虫信号蛋白质14-3-3编码基因的原核表达产物。分析纯化产物的免疫学特性。方法：SDS-PAGE鉴定重组日本血吸虫14-3-3（rSj14-3-3)蛋白包涵体，超声破碎细胞收集包涵体。尿素溶解包涵体，NiSO4平衡层析柱，亲和层析纯化rSj14-3-3,Western-blot鉴定纯化产物的免疫学特性。结果：rSj14-3-3是以包涵体形式在大肠埃希菌中表达。通过亲和层析在32.5kDa附近得到单一蛋白条带，Western-blot证实纯化产物为rSj14-3-3，且具有与天然Sj14-3-3相同的抗原表位。结论：成功纯化了rSj14-3-3蛋白，为研究14-3-3在血吸虫信号转导中的作用奠定了基础。     

沙眼衣原体T细胞抗原CT143原核表达、纯化及免疫活性鉴定

目的克隆沙眼衣原体（Chlamydia trachomatis,Ct）T细胞抗原Ct143基因,表达并纯化该蛋白,检测其免疫活性。方法采用PCR技术从ct基因组中扩增Ct143基因,并构建pGEX-6p—Ct143原核表达质粒,转化E．coli XL1-Blue．IPTG诱导重组GST-CT143融合蛋白表达,经酶切后得到无GST标签的纯蛋白免疫Balb／c鼠,ELISA及Western-blot分析CT143蛋白免疫原性及免疫反应性。结果成功构建了pGEX-6p—CT143原核表达质粒,序列测定证实重组质粒插入片段与GenBank登陆的CtD型一致,长度为843bp;GST—CT143融合蛋白在E．coli中获得稳定高效表达;纯蛋白与佐剂混匀后肌肉免疫小鼠,ELISA检测免疫小鼠的血清效价为1：12800,Westem blot结果表明该蛋白与Ct泌尿生殖道感染病人混合血清中IgG结合,具有免疫反应性。结论成功克隆表达了CtT细胞抗原CT143,该抗原经纯化后具有良好的免疫原性及免疫反应性。     

SARS冠状病毒单克隆抗体制备及在肺尸检标本染色中的应用

目的制备抗SARS冠状病毒的单克隆抗体,用于SARS的实验室诊断。方法灭活SARS冠状病毒(PUMC01)全病毒免疫BALB／C小鼠,取小鼠脾细胞与骨髓瘤细胞(NS-1)融合,用酶联免疫吸附试验(ELISA)、间接免疫荧光法(IFA)及免疫印迹法对所获得的细胞克隆进行筛选和鉴定,并用其中一株(M2)杂交瘤诱生的腹水单克隆抗体对SARS患者尸检肺组织切片进行免疫组织化学染色。结果共筛选出6株杂交瘤细胞,ELISA及IFA法证实其分泌的单克隆抗体与SARS冠状病毒有特异性反应,与其他常见呼吸道病原体均无交叉反应。免疫双扩散方法鉴定1株杂交瘤细胞(M2)为免疫球蛋白IgG3型,其余5株均为IgG1型。免疫印迹试验显示1株杂交瘤细胞(M2)分泌的抗体与相对分子质量68000的蛋白有特异性反应;4株杂交瘤细胞分泌的抗体与相对分子质量27000的蛋白有特异性反应,1株在免疫印迹上未见到结果。SARS患者尸检肺组织病理切片免疫组织化学染色阳性,在肺泡上皮细胞、支气管上皮细胞及巨噬细胞的胞浆均可见阳性颗粒。结论我们制备的6株单克隆抗体是抗SARS冠状病毒的特异性单克隆抗体,用于SARS尸检肺组织免疫组化染色,结果阳性。