梭形芽孢杆菌(Bacillus fusiforms)N141发酵产河豚毒素的研究

对分离筛选得到的产河豚毒素(TTX)的梭形芽孢杆菌(Bacillus fusiforms )N141菌株,在10 L发酵罐中进行发酵产TTX的试验.发酵产物经提取和精制后,用高效薄层色谱、小鼠生物试验,以及河豚毒素单抗ELISA检测试剂盒,检测出发酵液中含有TTX.研究了菌体生长、pH、溶氧、以及产物TTX的变化规律.结果表明TTX是在菌体生长进入稳定期后才产生的,说明TTX是微生物产生的次级代谢产物.10 L罐发酵产TTX的工艺技术,在500 L发酵罐进行了验证,重现性良好.这为微生物源河豚毒素的发酵中试提供了科学依据.     

Asia I口蹄疫vp2蛋白单克隆抗体的制备及单抗竞争ELISA方法的建立

制备Asia I口蹄疫病毒vp2单克隆抗体(mAb)并建立了单抗竞争ELISA方法。用纯化的Asia I型口蹄疫病毒vp2重组蛋白免疫BALB/c小鼠, 将免疫小鼠的脾细胞与骨髓瘤SP2/0细胞融合, 采用间接ELISA和有限稀释法筛选杂交瘤细胞。分别用ELISA、Western blotting检测mAb腹水的效价及其特异性。筛选到杂交瘤细胞2株, 腹水效价均在100×29以上; 以纯化后的Asia I型口蹄疫病毒vp2重组蛋白作为抗原, 利用Asia I型口蹄疫病毒vp2单抗酶标物建立了竞争ELISA方法用来检测Asia I型口蹄疫抗体。临床应用表明, 该方法与UBI公司的口蹄疫全病毒抗体检测试剂盒总符合率达89.0%, 和荷兰赛迪公司的口蹄疫病毒LPB-ELISA抗体检测试剂盒总符合率达86.5%。     

Asia Ⅰ口蹄疫vp2蛋白单克隆抗体的制备及单抗竞争ELISA方法的建立

制备Asia Ⅰ口蹄疫病毒vp2单克隆抗体(mAb)并建立了单抗竞争ELISA方法.用纯化的Asia Ⅰ型口蹄疫病毒vp2重组蛋白免疫BALB/c小鼠,将免疫小鼠的脾细胞与骨髓瘤SP2/0细胞融合,采用间接ELISA和有限稀释法筛选杂交瘤细胞.分别用ELISA、Western blotting检测mAb腹水的效价及其特异性.筛选到杂交瘤细胞2株,腹水效价均在100×2<'9>以上:以纯化后的AsiaⅠ型口蹄疫病毒vp2重组蛋白作为抗原,利用Asia Ⅰ型口蹄疫病毒vp2单抗酶标物建立了竞争ELISA方法用来检测Asia Ⅰ型口蹄疫抗体.临床应用表明,该方法与UBI公司的口蹄疫全病毒抗体检测试剂盒总符合率达89.0%,和荷兰赛迪公司的口蹄疫病毒LPB-ELISA抗体检测试剂盒总符合率达86.5%.     

中华蜜蜂囊状幼虫病病毒单克隆抗体的制备与鉴定

为了制备中华蜜蜂囊状幼虫病病毒(CSBV)单克隆抗体,本实验利用纯化的中华蜜蜂囊状幼虫病毒(CSBV)免疫Balb/c小鼠,经过3次免疫后,小鼠断尾采血测其血清效价,选择效价高于1∶80 000的小鼠,在细胞融合前3~4d再加强免疫一次。取免疫小鼠脾细胞与SP2/0骨髓瘤细胞进行细胞融合,用间接ELISA筛选阳性细胞株并进行3次亚克隆后注射入Balb/c小鼠(Mus musculus)腹腔制备单抗腹水。共获得9株稳定分泌抗CSBV的单克隆抗体,命名为10A1、5B10、5A5、5H2、11D7、9A5、1D3、3C10、10C4,效价都在1∶16 000以上,经间接ELISA实验检测表明,具有较好的特异性。在此基础上,将9株腹水单抗分别与CSBV互作后,接种于2~3日龄中华蜜蜂幼虫,观察幼虫死亡率,研究单克隆抗体中和CSBV病毒能力,结果表明筛选到三株单克隆抗体(10A1、5A5、9A5)对CSBV有中和作用,为CSBV的防治研究奠定了基础。     

鸡血清与卵黄中抗中华眼镜蛇毒IgY动态变化研究

目的探索特异性IgY的产生和变化规律。方法用眼镜蛇毒原毒免疫产蛋母鸡,ELISA定期检测卵黄中的抗体效价变化,小鼠体外中和实验检测其生物活性。第1次免疫40周后,眼镜蛇毒攻击已免疫母鸡,检测攻击前后鸡血清中抗体效价变化情况,未经眼镜蛇毒免疫的母鸡作阴性对照。结果经免疫后第7天蛋黄中即可检测到抗体,经多次加强免疫,40周时蛋黄中还能保持高效价的抗体,通过分离纯化,此抗体可保护实验小鼠免受4 LD50眼镜蛇毒的攻击;同时,鸡血清中也保留着较高效价的抗体,可中和4 LD50以上的眼镜蛇毒。结论用眼镜蛇毒免疫鸡,经多次加强免疫,卵黄和鸡血清中可持久保持高效价的特异性抗体,初步检测此抗体可中和4 LD50的蛇毒。     

日本七鳃鳗(Lampetra japonica)VLRB的克隆表达及单克隆抗体制备

七鳃鳗(Lampetra japonica)和盲鳗(Hyperotreti)作为现存的无颌类脊椎动物的代表,其适应性免疫系统中的受体分子与哺乳动物的抗原受体分子不同,这种独特的受体分子称为可变淋巴细胞受体VLRs(Variable lym-phocyte receptors)。目前VLRs分为3类,分别是VLRA、VLRB、VLRC,而VLRB由七鳃鳗类B淋巴细胞产生,是其体液免疫中主要成分,与IgM结构和功能类似。文章对日本七鳃鳗VLRB基因保守的C末端进行克隆、原核表达和重组蛋白纯化后,免疫Balb/c小鼠,通过细胞融合及间接酶联免疫吸附实验(Enzyme-linked immu-nosorbent assay,ELISA)筛选技术得到针对VLRB保守区的单克隆抗体细胞株。将杂交瘤细胞接种小鼠腹腔得到大量的单抗腹水,经Protein G亲和纯化后的单抗进行ELISA与Western blotting检测。经ELISA检测抗体效价为1:40000。Western blotting结果显示该单克隆抗体能够特异的检测重组VLRB蛋白及七鳃鳗血清中分泌型VLRB。流式细胞实验证明该单抗能特异识别七鳃鳗类淋巴细胞表面表达的膜型VLRB。VLRB单克隆抗体的成功制备和建株,为研究日本七鳃鳗基于VLR的适应性免疫系统提供了重要的工具。     

肺炎链球菌C多糖含量检测方法的建立

目的使用肺炎链球菌C多糖单克隆抗体(单抗),建立检测荚膜多糖中残留的C多糖含量的方法。方法选择BALB/c雌性小鼠,采用体内诱生单抗腹水,放大生产肺炎链球菌C多糖单抗;使用间接ELISA、抑制性ELISA对其进行特异性鉴定;用特异性和亲和力高的单抗尝试建立肺炎链球菌荚膜多糖中C多糖含量检测的速率比浊法,并对该方法的线性、精密度、特异性进行验证。结果所制4株单抗的抗体类别均为IgM,识别的抗原表位互不相同,亲和力也不同。间接ELISA、抑制性ELISA结果均显示,所获得的单抗能够作用于肺炎链球菌C多糖上的磷酸胆碱位点,具有很好的特异性。选择单抗E8建立速率比浊检测方法的线性、精密度和特异性均良好,检测结果表明肺炎链球菌23个血清型荚膜多糖中C多糖含量不同。结论利用单抗建立了检测肺炎链球菌荚膜多糖中残留的C多糖的含量的速率比浊法。     

抗炭疽人源化单抗在炭疽芽孢致死小鼠模型中的治疗效力评价

目的:建立炭疽芽孢(疫苗株A16R)攻击DBA/2J小鼠的致死模型,并使用该模型评价抗炭疽人源化单抗5E11的治疗效力。方法:用不同剂量A16R芽孢背部皮下攻击小鼠,计算半数致死剂量(LD_(50));ELISA定量检测5E11在小鼠体内的药代动力学参数;用100倍LD_(50)的芽孢攻击小鼠,攻毒后不同时间用不同剂量的5E11单抗治疗小鼠,观察小鼠存活等情况。结果:A16R芽孢攻击DBA/2J小鼠的LD50为7.8×10～3CFU;5E11在小鼠体内的平均消除半衰期约为7 d;攻毒后1 d给药的几个剂量组能够完全保护,攻毒后2～3 d给药能够提供40%～80%的保护。结论:抗炭疽人源化单抗5E11在芽孢攻击致死小鼠模型中表现出良好的保护效果,具有紧急治疗炭疽芽孢感染导致的急性炭疽的潜力。     

应用A蛋白亲和层析法纯化单克隆抗体

应用Protein A亲和层析法,从采集的小鼠腹水中纯化出了抗凝血因子Ⅶ单克隆抗体,用SDS-PAGE和ELISA法分别检测了纯化后单克隆抗体的纯度及效价,结果显示,电泳为两条带,分别为免疫球蛋白G(IgG)的重链和轻链,纯化后的单克隆抗体纯度达到电泳纯,应用间接ELISA法测定腹水效价为1×10-7左右,与未纯化前无差异。结果表明,应用A蛋白亲和层析法能够得到纯度较高的单克隆抗体,适用于高纯度单克隆抗体的制备。     

巴泰病毒单克隆抗体的制备及鉴定

巴泰病毒(Batai virus,BATV)是一种人兽共患病毒,近年在全球广泛流行。我国也有人和动物感染的相关报道,而目前对BATV的研究仅局限于分子检测和全基因测序,还没有关于BATV单克隆抗体的相关研究,但制备特异性强、活性好的单克隆抗体也是防控BATV的关键。为了制备BATV单克隆抗体,本研究利用纯化的BATV作为抗原免疫雌性BALB/c小鼠,制备鼠源单克隆抗体。通过免疫小鼠后断尾取血,间接ELISA测其血清效价后,将SP2/0细胞与小鼠的脾细胞融合。ELISA方法筛选阳性细胞株,并进行亚克隆后制备单抗腹水,并利用辛酸-硫酸铵沉淀法纯化腹水。结果获得7株单克隆抗体,包括5株IgG型和2株IgM型。其中制备的3E2单克隆抗体效价最高为1∶32 000。经间接ELISA、间接免疫荧光和Western Blot检测表明,制备的3E2单抗具有较好的纯度、活性和特异性,为BATV快速检测方法的建立及致病机制研究奠定了基础。     

克伦特罗单克隆抗体的纯化及其生物学特性的研究

目的：将自制克伦特罗（CL）单克隆抗体纯化并研究其生物学特性,进行性质鉴定并建立检测标准曲线。方法：用ELISA法测定克伦特罗单克隆抗体的亲和常数和抗体活性,ELJSA测定单克隆抗体与BSA的交叉反应及与几种结构和功能类似物的交叉反应,然后采用间接竞争ELISA方法建立检测标准曲线。将制备的含克伦特罗单克隆抗体的小鼠腹水用盐析法和免疫亲和柱层析法进行抗体纯化。结果：经ELISA法测定,单克隆抗体亲和常数为2．90×10mmol／L,抗体效价最高达10^6。单克隆抗体对BSA无反应,对几种结构和功能类似物的交叉反应率均小于0．005％。建立的标准曲线R2=0．9812,最低检测限为1．0ng／ml。结论：建立了间接竞争ELISA检测cL的标准曲线。自制的克伦特罗单克隆抗体亲和力好,特异性高。为以后实际样品的检测及制备CL免疫检测试纸条和试剂盒奠定了基础。     

庆大霉素单克隆抗体的制备及试剂盒的配制

目的建立庆大霉素直接竞争酶联免疫吸附分析方法。方法应用戊二醛法制备庆大霉素完全抗原,通过杂交瘤技术筛选分泌特异性庆大霉素抗体的杂交瘤细胞株,并建立庆大霉素竞争酶联免疫吸附分析检测方法。结果获得3株能稳定分泌庆大霉素单克隆抗体的杂交瘤细胞株,建立了庆大霉素竞争酶联免疫吸附分析检测方法,该方法操作简单具有良好的线性、特异性和精密度;庆大霉素质量浓度在1.5625～50.0000 ng/mL范围内,呈现良好的线性,r2=0.9913,50%抑制浓度为(IC50)为7.37 ng/mL,检测限(LOD)为1.54 ng/mL,该试剂盒与链霉素等8种药物无交叉反应。结论获得3株能稳定分泌庆大霉素单克隆抗体的杂交瘤细胞株,研制的庆大霉素竞争ELISA检测试剂盒具有良好的线性、特异性和精密度。     

A new monoclonal antibody detecting ochratoxin A at the picogram level

Á. GYÖNGYÖSI-HORVÁTH, I. BARNA-VETRÓ AND L. SOLTI. 1996. A monoclonal antibody against ochratoxin A was produced after immunization of Balb/c mice with ochratoxin A-BSA. This antibody was of the IgGl heavy chain subclass with a k type light chain. The 50% inhibition value was 0.45 ng ml^-1 in a direct competitive ELISA and the detection limit was 42 pg ml^-1. This antibody is very specific, cross-reacting only with ochratoxin B (9.3%).     

Quantitation of poliovirus antigens in inactivated viral vaccines by enzyme-linked immunosorbent assay using animal sera and monoclonal antibodies

Recent advances in methods for the manufacture of inactivated poliovirus vaccines have resulted in increased vaccine immunogenicity. In conjunction with this capability it is important to have available highly sensitive and quantitative potency assays. The potential suitability of enzyme-linked immunoassay (ELISA) was evaluated using animal sera with neutralizing antibodies or neutralizing monoclonal antibodies for antigen detection in potency tests. The monoclonal antibodies developed, which bound D antigen but not C antigen, were neutralizing unless relatively weakly reactive. Those that bound C antigen only were non-neutralizing. Those that bound both C and D antigens were sometimes neutralizing. D-specific and D/C-specific neutralizing monoclonal antibodies against type-2 poliovirus protected mice on passive immunization against paralytic disease and death from the MEF strain virus. Potency measurements by ELISA using either D-specific neutralizing monoclonal antibodies or type-specific goat sera for antigen detection were sensitive and precise. Tests using C-specific monoclonal antibodies for antigen detection indicated that increased C antigen content may result in falsely elevated reactivities of animal sera with some vaccines. Monoclonal antibodies may be useful ELISA reagents for IPV potency testing.     

A competitive displacement assay to detect saxitoxin and tetrodotoxin

An assay is described which detects saxitoxin (STX) and tetrodotoxin (TTX) by their competitive displacement of [³H]saxitoxin from its receptor in rat brain membranes. The assay has a sensitivity of 0.15 ng STX/ml and 0.8 ng TTX/ml for buffer samples. The assay was also applied to detection of these toxins in unextracted human plasma and found to have a sensitivity of 0.5 ng STX/ml and 0.6 ng TTX/ml. The competitive displacement assay appears to be the most sensitive procedure yet for detection of STX and TTX.     

金霉素单克隆抗体的制备及检测方法的建立

采用羰基二咪唑法,将半抗原金霉素(AM)分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)偶联制备金霉素免疫抗原AM-BSA和检测抗原AM-OVA,通过紫外光谱扫描检测偶联产物。采用细胞杂交瘤技术,制备抗金霉素单克隆抗体杂交瘤细胞株,建立了金霉素竞争ELISA检测方法,其灵敏度达到50ng/ml,且呈现良好的线性关系(r=0.9812),并且与其他抗生素无交叉反应。     

Development and characterization of monoclonal antibodies against Rift Valley fever virus nucleocapsid protein generated by DNA immunization

This paper describes the generation of monoclonal antibodies directed to immunogenic nucleoprotein N epitopes of Rift Valley fever virus (RVFV), and their application in diagnostics, both for antibody detection in competitive ELISA and for antigen capture in a sandwich ELISA. Monoclonal antibodies (mAbs) were generated after DNA immunization of Balb/c mice and characterized by Western blot, ELISA and cell immunostaining assays. At least three different immunorelevant epitopes were defined by mAb competition assays. Interestingly, two of the mAbs generated were able to distinguish between RVFV strains from Egyptian or South African lineages. These monoclonal antibodies constitute useful tools for diagnosis, especially for the detection of serum anti-RVFV antibodies from a broad range of species by means of competitive ELISA.     

Reexamination of tetrodotoxin production by bacteria.

Vibrio alginolyticus has been reported as a good producer of tetrodotoxin (TTX), but the toxin extracted from this bacterium did not react to the monoclonal antibody against TTX. Surprisingly, chromatographic analyses detected high TTX peaks for polypeptone and yeast extracts used as medium materials, which were, as expected, all negative by the mouse bioassay. These results may require us to revise the bacterial production of TTX.     

High-throughput determination of free D-aspartic acid in mammals by enzyme immunoassay using specific monoclonal antibody

A method for rapid determination of free d-aspartic acid (d-Asp) in mammals has been established using a highly specific mouse monoclonal antibody against d-Asp for the first time. An anti-d-Asp monoclonal antibody was obtained by the immunization of bovine-serum-albumin-conjugated d-Asp to BALB/c mice. The obtained antibody has a high specificity toward d-Asp but shows a slight cross-reactivity to all other d- and l- amino acids including l-Asp. The calibration range of the competitive enzyme linked immunosorbent assay (ELISA) is 0.016-16 μmol/mL d-Asp in rat serum samples. The precisions of this method were evaluated by inter-plate and intraplate assays, and the relative standard deviation values were 4.8% and 4.5%, respectively. The values of d-Asp determined by the present ELISA have a good correlation to those determined by high-performance liquid chromatography with the correlation coefficient of 0.963. Using this ELISA, the time course of d-Asp in the rat serum after intravenous administration was successfully demonstrated. The present method provides a simple and high-throughput determination of d-Asp in mammals, and is a useful tool for clarifying the physiological roles and diagnostic values of this d-amino acid.