Prokaryotic Expression and Identification of Outer Membrane Protein 2 of Chlamydia trachomatis

Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.

Water relations and an expression analysis of plasma membrane intrinsic proteins in sensitive and tolerant rice during chilling and recovery

A symptom of chilling injury is development of water deficit in shoots, resulting from an imbalance of water transport and transpiration. In this work, two rice varieties （Oryza sativa L. var. Wasetoitsu and Somewake） seedlings were chilled at 7 ℃, followed by recovery at 28 ℃. Based on the growth phenotype and electrolyte leakage tests, Somewake was shown to be a chilling-tolerant variety, and Wasetoitsu a chilling-sensitive one. The chilling stress reduced markedly the relative water content （RWC） of leaves, accumulative transpiration and osmotic root hydraulic conductivity （Lp） in both varieties. But when retumed to 28 ℃, the water relation balance of Somewake recovered better. The mRNA expression profile of all the 11 plasma membrane intrinsic proteins （PIPs）, a subgroup of aquaporins, was subsequently determined by real-time reverse transcription （RT）-PCR with TaqMan-minor grove binder （MGB） probes derived from rice var. Nipponbare during chilling treatment and recovery. Most of the PIP genes was down-regulated at the low temperature, and recovered at the warm temperature. The relative expression of some PIPs in both Somewake and Wasetoitsu decreased in parallel during the chilling. However during the recovery, the relative expression of OsPIP1;1, OsPIP2;1, OsPIP2;7 in shoots and OsPIP1：1, OsPIP2：1 in roots were significantly higher in Somewake than Wasetoitsu. This supports the role of PIPs in re-establishing water balance after chilling conditions. We discuss the diversified roles played by members of the aquaporin PIP subfamily in plant chilling tolerance depending on aquaporin isoforms, plant tissue and the stage of chilling duration.

Expression and Purification of SARS Coronavirus Membrane Protein

To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E.Coli) BL21 (DE3) and induced by Isopropyl-β-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.9921 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.

Gene cloning and prokaryotic expression of recombinant outer membrane protein from Vibrio parahaemolyticus

Gram-negative Vibrio parahaemolyticus is a common pathogen in humans and marine animals, The outer membrane protein of bacteria plays an important role in the infection and pathogenicity to the host. Thus, the outer membrane proteins are an ideal target for vaccines. We amplified a complete outer membrane protein gene （ompW） from E parahaemolyticus ATCC 17802. We then cloned and expressed the gene into Escherichia coli BL21 （DE3） cells. The gene coded for a protein that was 42.78 kDa. We purified the protein using Ni-NTA affinity chromatography and Anti-His antibody Western blotting, respectively. Our results provide a basis for future application of the OmpW protein as a vaccine candidate against infection by E parahaemolyticus. In addition, the purified OmpW protein can be used for further functional and structural studies.

Bcl-2 over-expression and activation of protein kinase C suppress the Trail-induced apoptosis in Jurkat T cells

Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.

Expression of lipopolysaccharide binding protein and its receptor CD14 in experimental alcoholic liver disease

AIM: To evaluate the relationship between the expression of lipopolysaccharides (LPS) binding protein (LBP) and CD14 mRNA and the severity of liver injury in alcohol-fed rats. METHODS: Twenty Wistar rats were divided into two groups:ethanol-fed group (group E) and control group (group C). Group E was fed with ethanol(5-12 g x kg(-1) x d(-1)) and group C received dextrose instead of ethanol. Rats of the two groups were sacrificed at 4 weeks and 8 weeks. Levels of endotoxin and alanine transaminase (ALT) in blood were measured, and liver pathology was observed under light and electronic microscopy. Expressions of LBP and CD14 mRNA in liver tissues were determined by RT-PCR analysis. RESULTS: Plasma endotoxin levels were increased more significantly in group E(129+/-21) ng x L(-1) and (187+/-35) ng x L(-1) at 4 and 8 wk than in control rats(48+/-9) ng x L(-1) and (53+/-11) ng x L(-1), respectively (P【0.05). Mean values of plasma ALT levels were (1867+/-250) nkat x L(-1) and (2450+/-367) nkat x L(-1) in Group E. The values were increased more dramatically in ethanol-fed rats than in Group C after 4 and 8 weeks. In liver section from ethanol-fed rats, there were marked pathological changes (steatosis, cell infiltration and necrosis). In ethanol-fed rats, ethanol administration led to a significant increase in LBP and CD14 mRNA levels compared with the control group (P【0.05). CONCLUSION: Ethanol administration led to a significant increase in endotoxin levels in serum and LBP and CD14 mRNA expressions in liver tissues. The increase of LBP and CD14 mRNA expression might wake the liver more sensitive to endotoxin and liver injury.

Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody

Aim： To investigate the possible functions of human sperm membrane protein （hSMP-1） in the process of fertilization. Methods： A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 （anti-rhSMP-1） antibodies. Sperm acrosome reaction and spermzona pellucida （ZP） binding assay were carried out in 10-week-old BALB/c mice. Results： Recombinant hSMP-1 was successfully cloned and expressed. The expression of the native protein was limited on the acrosome of human and mouse sperm. Treatment of anti-rhSMP-1 antibodies significantly decreased the average number of sperms bound to each egg. Meanwhile, the percentage of acrosome reaction was decreased in comparison to pre-immune control after treatment with anti-rhSMP-1 （P 〈 0.05）. Conclusion： The results suggest that anti-rhSMP-1 antibody inhibited mouse acrosome reaction and sperm-ZP binding.

Expression Characterization and Preparation of Human Amyloid Precursor Protein in Escherichia coli

To analyze whether expressed amyloid precursor protein（APP） existed in hydrophilic（cytoplasmid） or hydrophobic（lipid bilayer） environment in E. coli and to obtain intact APP for study on its function, we investigated the expression characterization and preparation of the three intact isoforms APP770, APP751, and APP695 in E. coll. The results show that these expressed APPs existed both in hydrophilic cytoplasm region as inclusion bodies and hydrophobic membrane region as membrane-bound state in E. coll. APPs in inclusion bodies were purified on an NTA-Ni^2＋ agarose column after dissolving in the urea buffer and APPs in membrane-bound state were obtained by ultracentrifugation. The activity analysis indicates that APP770 and APP751 exhibited strong trypsin-inhibitory activity like the natural ones. These results indicate that E. coli cells can be used as host cells for the expression of human integral membrane protein like APP in either soluble or membrane-bound state unless the interest protein undergone post-translational modification is required.

C-type lectins and human epithelial membrane protein1:Are they new proteins in keratin disorders?

Here we report a family with a clinical spectrum of Pachyonychia Congenita Tarda (PCT) encompassing two generations via a balanced chromosomal translocation between 4q26 and 12p12.3. We discuss the effects of chromosomal translocations on gene expression through involved breakpoints and structural gene abnormalities detected by array CGH. We believe that the family we present gives further insight to the better understanding of molecular and structural basis of keratin disorders, and to the late onset and genetic basis of PCT through the possible role of C-type lectins and human epithelial membrane protein1 (EMP1). Better understanding of the molecular basis of keratin disorders is the foundation for improved diagnosis, genetic counseling and novel therapeutic approaches to overcome the current treatment limitations related to this disease.

Adenovirus-mediated expression of pig α(1,3) galactosyltransferase reconstructs Gal α(1,3) Gal epitope on the surface of human tumor cells

Gal alpha(1, 3) Gal (gal epitope) is a carbohydrate epitope and synthesized in large amount by alpha(1, 3) galactosyltransferase [alpha(1, 3) GT] enzyme on the cells of lower mammalian animals such as pigs and mice. Human has no gal epitope due to the inactivation of alpha(1, 3) GT gene but produces a large amount of antibodies (anti-Gal) which recognize Gal alpha(1, 3) Gal structures specifically. In this study, a replication-deficient recombinant adenoviral vector Ad5sGT containing pig alpha(1, 3) GT cDNA was constructed and characterized. Adenoviral vector-mediated transfer of pig alpha(1, 3) GT gene into human tumor cells such as malignant melanoma A375, stomach cancer SGC-7901, and lung cancer SPC-A-1 was reported for the first time. Results showed that Gal epitope did not increase the sensitivity of human tumor cells to human complement-mediated lysis, although human complement activation and the binding of human IgG and IgM natural antibodies to human tumor cells were enhanced significantly after Ad5sGT transduction. Appearance of gal epitope on the human tumor cells changed the expression of cell surface carbohydrates reacting with Ulex europaeus I (UEA I) lectins, Vicia villosa agglutinin (VVA), Arachis hypogaea agglutinin (PNA), and Glycine max agglutinin (SBA) to different degrees. In addition, no effect of gal epitope on the growth in vitro of human tumor cells was observed in MTT assay.

Heterologous Soluble Expression of Recombinant OmpR of <i>Aeromonas hydrophila</i>and Its Immunogenic Potential

Aeromonas hydrophila, a gram negative bacterium is a major fish pathogen and causes major economic losses to aquaculture industry. Outer membrane proteins play a significant role in its survival during different environmental conditions and bacterial pathogenesis. The outer membrane protein R (OmpR) is a member of the two-component regulatory system of Aeromonas hydrophila which differentially regulates the expression of OmpF or OmpC depending on the osmolarity conditions. Role of OmpR has been demonstrated in its virulence in other infectious bacteria and it is found to be a potential drug target/vaccine candidate. However, the OmpR of A. hydrophila has not been characterized. In the present study, we report recombinant expression, purification of the OmpR of A. hydrophila strain Ah17 in salt inducible E. coli GJ1158 cells. Leaky expression of rOmpR was confirmed by Western blot analysis using anti-6 × His antibody. The histidine tagged recombinant OmpR (rOmpR) (~29 kDa) was purified using Ni-NTA affinity chromatography from the soluble fraction of induced E. coli cells. The rOmpR was found to be highly immunogenic with end point titres of greater than 1:80,000. The anti-rOmpR antisera were capable of agglutinating live A. hydrophila cells, thus showing vaccine potential of the rOmpR.

血清IL-2、sST2表达与特发性膜性肾病免疫抑制剂治疗反应性的相关性

目的探讨特发性膜性肾病患者血清白介素-2(IL-2)、可溶性生长刺激表达基因2蛋白(sST2)表达水平与免疫抑制剂治疗反应性的相关性。方法选取2020年1月至2022年10月于医院接受免疫抑制剂治疗的135例特发性膜性肾病患者,于入院时检测患者血清IL-2、sST2,并于治疗完成后测定24 h尿蛋白定量,依据患者治疗反应性分为缓解组与未缓解组。对比两组患者一般资料及入院时血清IL-2、sST2水平,采用点二列相关性分析血清IL-2、sST2水平与特发性膜性肾病免疫抑制剂治疗反应性的关系,并绘制受试者工作特征(ROC)曲线评估血清IL-2、sST2水平预测特发性膜性肾病免疫抑制剂治疗反应性的价值。结果135例特发性膜性肾病患者中共有132例完成规律治疗,经免疫抑制剂治疗6个月后,101例患者疾病缓解,纳入缓解组,其余31例患者纳入未缓解组。未缓解组年龄、入院时肾功能分级、疾病分期、血清IL-2、sST2水平均高于缓解组,差异有统计学意义(P<0.05);点二列相关性分析显示,血清IL-2、sST2水平与特发性膜性肾病免疫抑制剂治疗反应性不良风险呈正相关(r 1=0.428,P 1<0.001;r 2=0.344,P 2<0.001);绘制ROC曲线,结果显示,血清IL-2、sST2预测特发性膜性肾病免疫抑制剂治疗反应性不良的曲线下面积均>0.7,具有一定预测价值,且联合预测价值更高。结论血清IL-2、sST2表达水平与特发性膜性肾病患者免疫抑制剂治疗反应性密切相关,二者表达水平越高,治疗反应性越差,且联合检测可作为预测特发性膜性肾病患者免疫抑制剂治疗反应性的敏感指标。

The recombinant expression systems for structure determination of eukaryotic membrane proteins

Eukaryotic membrane proteins, many of which are key players in various biological processes, constitute more than half of the drug targets and represent important candidates for structural studies. In contrast to their physiological significance, only very limited number of eukaryoUc membrane protein structures have been obtained due to the technical challenges in the genera- tion of recombinant proteins. In this review, we examine the major recombinant expression systems for eukaryotic membrane proteins and compare their relative advantages and disadvantages. We also attempted to summarize the recent technical strategies in the advancement of eukaryotic membrane protein purification and crystallization.

Molecular characterization and expression of sensory neuron membrane proteins in the parasitoid Microplitis mediator (Hymenoptera: Braconidae)

Sensory neuron membrane proteins(SNMPs),homologs of the human fatty acid transport protein CD36 family,are observed to play a significant role in chemoreception,especially in detecting sex pheromone in Drosophila and some lepidopteran species.In the current study,two full‐length SNMP transcripts,MmedSNMP1 and MmedSNMP2,were identified in the parasitoid Microplitis mediator(Hymenoptera:Braconidae).Quantitative real‐time polymerase chain reaction analysis showed that the expression of MmedSNMP1 was significantly higher in antennae than in other tissues of both sexes.In addition,the MmedSNMP1 transcript was increased dramatically in newly emerged adults and there were no significant differences between adults with or without mating and parasitic experiences.However,compared with MmedSNMP1,the expression of MmedSNMP2 was widely found in various tissues,significantly increased at half‐pigmented pupae stage and remained at a relatively constant level during the following developmental stages.It was found that MmedSNMP1 contained eight exons and seven introns,which was highly conserved compared with other insect species.In situ hybridization assay demonstrated that MmedSNMP1 transcript was distributed widely in antennal flagella.Among selected chemosensory genes(odorant binding protein,odorant receptor,and ionotropic receptor genes),MmedSNMP1 only partially overlapped with MmedORco in olfactory sensory neurons of antennae.Subsequent immunolocalization results further indicated that MmedSNMP1 was mainly expressed in sensilla placodea of antennae and possibly involved in perceiving plant volatiles and sex pheromones.These findings lay a foundation for further investigating the roles of SNMPs in the chemosensation of parasitoids.

滑液囊支原体GA组件蛋白的原核表达及间接ELISA方法的建立

【目的】体外表达滑液囊支原体(Mycoplasma synoviae,MS)的GA组件蛋白(GA module-containing protein),建立一种MS抗体检测方法,用于血清学检测及MS抗体水平监测。【方法】分析、筛选MS的GA组件蛋白长链保守结构域,合成重组质粒pET30a-ΔGA-L,转化大肠杆菌BL21(DE3)感受态细胞进行诱导表达,并优化表达条件;通过SDS-PAGE检测重组蛋白的表达,纯化重组蛋白ΔGA-L并进行Western blotting鉴定;以纯化后的重组蛋白ΔGA-L作为包被抗原,建立MS抗体的间接ELISA检测方法,优化反应条件,确定临界值,对其特异性、敏感性、重复性进行检验,并进行临床样品检测。【结果】重组蛋白ΔGA-L的分子质量大小为45.7 ku,最佳表达条件为25℃、0.2 mmol/L IPTG诱导表达5 h,以包涵体形式表达。Western blotting结果表明,重组蛋白ΔGA-L能与MS抗体发生特异性反应。以ΔGA-L抗原包被浓度为0.5μg/mL,一抗稀释度为1∶400,二抗稀释度为1∶12 000为最佳条件,建立了MS抗体间接ELISA检测方法,其阴阳性临界值为0.283;所建立方法特异性强、灵敏度高,有较高稳定性;与商品化MS抗体检测试剂盒总符合率为96%。【结论】本研究成功表达了MS重组蛋白ΔGA-L,所建立的MS抗体间接ELISA检测方法具有良好的特异性、敏感性、重复性,为MS抗体检测提供了有效快捷的方法。

油莎豆块茎高水平表达CePIP1;1基因的克隆与分析

油莎豆隶属于禾本目莎草科,是一种在块茎中高水平积累油脂的新型草本油料作物。与其他块根块茎类作物类似,未成熟油莎豆块茎的含水量高达85%,因此,水分平衡对于块茎的发育至关重要。质膜内在蛋白(PIP)是一类定位在细胞膜上具有高效水分转运活性的水通道蛋白,包含PIP1和PIP2两个亚类。本研究基于块茎蛋白组中鉴定到的一个PIP蛋白,采用RT-PCR技术对其编码基因进行克隆,并在此基础上分析其基因结构、序列特征、进化关系、表达特性及蛋白亚细胞定位。结果表明:CePIP1;1含有3个内含子,编码区全长867 bp,编码288个氨基酸,理论分子量为30.76 kDa,等电点为8.82,不稳定系数为32.95,总平均疏水指数为0.384,脂肪族指数为95.28,属于稳定的碱性疏水型蛋白;该蛋白含有保守的MIP结构域,其中包括6个跨膜螺旋、2个半螺旋以及位于半螺旋顶端的NPA基序。序列比对和进化分析显示,CePIP1;1与水稻的PIP1亚类聚在一起,相比于菠菜PIP2;1拥有延伸的N端和较短的C端,符合PIP1亚类的基本特征。在烟草叶片中的亚细胞定位分析显示,CePIP1;1定位在细胞膜,这与生物信息学预测结果一致。表达分析显示,CePIP1;1在分析的所有组织中均高水平表达,属于组成型表达基因,其在块茎的发育过程中呈现先升后降的钟形趋势,与水分含量趋势基本一致。这些结果为下一步的功能分析及油莎豆遗传改良奠定坚实的基础。

幽门螺杆菌东亚型菌株GZ7/cagA^(+)和GZ7/ΔcagA源外膜囊泡的蛋白组学比较

目的通过分离、鉴定和比较细胞毒素相关基因A蛋白(cagA)、阳性幽门螺杆菌(H.pylori)、东亚型菌株GZ7/cagA^(+)及其cagA敲除菌株GZ7/ΔcagA来源的外膜囊泡(OMVs)中的差异表达蛋白(DEPs),分析cagA基因对OMVs中蛋白表达的影响。方法采用超速离心法分别提取GZ7/ΔcagA和GZ7/cagA^(+)的OMVs,通过透射电镜和纳米颗粒追踪技术鉴定其形态和粒径,使用Western blot技术验证两组OMVs中cagA蛋白的表达,分析OMVs的蛋白质组学;对蛋白组学数据进行质控分析和主成分分析鉴定后,以上调蛋白倍数变化(FC)>2.0、下调蛋白FC<0.5,FDR≤0.05为筛选条件筛选DEPs,利用OmicsBean在线工具、Gene Ontology和KOBAS对DEPs进行生物信息学分析;采用免疫荧光鉴定OMVs细胞在细胞中的定位,实时无标记细胞分析仪检测细胞活性。结果通过电镜和粒径证实成功分离纯化了OMVs;蛋白质组分析发现,GZ7/cagA^(+)-OMVs组与GZ7/ΔcagA-OMVs组比较有79个DEPs,其中38个蛋白下调、41个蛋白上调;生物信息学分析显示,DEPs主要与丙酮酸代谢、丙酸代谢、糖酵解/糖异生及柠檬酸循环等代谢途径有关;免疫荧光和实时无标记细胞分析证实H.pylori来源的OMVs能进入细胞并定位在线粒体并抑制细胞增殖。结论cagA能影响H.pylori分泌的OMVs中蛋白质的成分,DEPs可能促进cagA^(+)H.pylori在胃黏膜上的定植及致病性。

油莎豆CePIP2;1的克隆、亚细胞定位与表达分析

油莎豆是一种在块茎中高水平积累油脂的草本油料作物,其未成熟块茎的含水量高达85%,水分平衡对于块茎的发育与代谢至关重要。质膜内在蛋白(PIP)是介导细胞间水分跨膜运输的主要通道。本研究报道1个块茎高水平表达的PIP基因CePIP2;1,该基因含有3个内含子,预测编码288个氨基酸(aa),其理论分子量(MW)为30.34 kDa,等电点(pI)为8.60,总平均疏水指数(GRAVY)为0.529,不稳定系数(Ⅱ)为29.60,属于典型的稳定、碱性、疏水型蛋白。CePIP2;1含有保守的MIP结构域,ar/R选择性滤器为F-H-T-R,Froger位点为Q-S-A-F-W,符合高水分转运活性PIP的特征。进化分析显示,CePIP2;1与OsPIP2;1、OsPIP2;2和OsPIP2;3聚在一起,序列相似性分别为91.72%、90.31%和84.98%,支持其归为PIP2亚类。亚细胞定位分析显示,CePIP2;1定位在烟草叶片的细胞膜。进一步的表达分析显示,虽然CePIP2;1为主要的块茎表达PIP基因,但其在叶片、叶鞘、匍匐茎和根等组织中的表达丰度更高,最高的为叶片,而在芽尖中的表达丰度与块茎相当;在块茎的4个典型发育时期(S_(1)~S_(4))中,CePIP2;1基因呈现先升后降的钟形趋势,表达丰度最高的是S_(2)。这些结果为解析油莎豆的水分平衡机制奠定基础。

A Sensitive and Specific IgM-ELISA for the Serological Diagnosis of Human Leptospirosis Using a rLipL32/1-LipL21-OmpL1/2 Fusion Protein

Objective To construct a lipL32//1-1ipL21-OmpL1//2 fusion gene and its prokaryotic expression system, and to establish an enzyme-linked immunosorbent assay （ELISA） using the rLipL32/1-LipL21-OmpL1/2 fusion antigen of Leptospira interrogans for sensitive and specific detection of IgM in the serum of patients with leptospirosis. Methods lipL32/1-1ipL21-OmpL1/2 fusion genes were constructed using a primer-linking PCFI. The target recombinant protein antigens, rLipL32/1, rLipL21, rOmpL1/2 and rLipL32/1-LipL21-OmpL1/2, were expressed and the purified antigens were then immobilized to the surface of microplate wells for ELISA-based detection of IgM in the sera of leptospirosis patients; Results Of 493 acute leptospirosis patients, 95.7% and 97.8% were positive by rLipL32/1-LipL21- OmpL1/2-1gM-ELISA using different serum dilutions, which was higher than the rLipL32/1-1gM-ELISA （93.1% and 90.3%）, rLipL21-1gM-ELISA （90.3% and 87.0%）, and rOmpLI-lgM-ELISA （85.6% and 81.1%） （P〈0.01）. All IgM-ELISAs tested negative against 56 non-leptospirosis patients with typhoid fever, hemorrhagic fever or dengue fever. Conclusion Trigeminal fusion antigen increases ELISA sensitivity and the rLipL32/1-LipL21-OmpL1/2- IgM-ELISA is a sensitive and specific serological diagnostic method for clinical leptospirosis.

布鲁氏菌外膜蛋白16单克隆抗体的制备及初步应用

旨在制备布鲁氏菌外膜蛋白16(OMP16)单克隆抗体,建立OMP16抗体竞争ELISA方法,为布病临床防控提供免疫血清学检测手段。本研究选取保守性高、免疫原性良好的布鲁氏菌OMP16,经原核表达获得携带GST或His标签的重组OMP16(rOMP16)。利用杂交瘤技术筛选可稳定分泌OMP16特异性单克隆抗体的杂交瘤细胞株,经亚型鉴定、细胞核型分析和抗体交叉反应性试验分析单抗性质。制备小鼠腹水并纯化,方阵滴定法建立布鲁氏菌OMP16抗体竞争ELISA方法。结果表明,成功构建OMP16原核表达系统,经表达、纯化获得rGST-uOMP16和rHis-OMP16。筛选到1株遗传稳定的OMP16特异性杂交瘤细胞株,命名为B7;经鉴定,该抗体亚型为IgM-κ型,可识别目的蛋白,与标签蛋白无交叉反应。建立了布鲁氏菌OMP16抗体竞争ELISA方法,该方法与试管凝集试验检测结果相比总体符合率为90.53%,显示出良好的一致性。本研究有望为布鲁氏菌病的临床防控提供特异性高、敏感性好的免疫血清学检测方法。