抗禽流感病毒H5N1亚型单克隆抗体制备初报

目的制备禽流感H5N1亚型病毒的单克隆抗体,为相关研究提供工具。方法以禽流感H5N1亚型病毒免疫BALBc小鼠,取其脾细胞和SP20细胞融合,用血凝抑制试验(HI)和酶联免疫反应(ELISA)检测培养上清,并将阳性融合细胞稀释克隆化3次直至100%孔均为阳性,筛选阳性克隆株,运用免疫荧光法评估单克隆抗体检测病毒感染的犬肾细胞(MDCK)。结果得到三株稳定分泌抗体的细胞并命名为F8、F9、G11,抗体亚型鉴定结果分别为IgG1、IgG2a和IgG2b;在免疫荧光法单克隆抗体能够检测出感染MDCK细胞的病毒。结论建立了3株抗禽流感H5N1亚型病毒的单克隆抗体细胞株,其产生的一株高特异性的McAbG11能够用于H5N1亚型禽流感病毒感染诊断,并可能应用于禽流感病毒H5N1亚型感染的防治。     

Oxidation of tyrosine by peroxidase isozymes derived from peanut suspension culture medium and by isolated cell walls

A comparative study on tyrosine oxidation was made with a pure cationic and anionic peroxidase from peanut cell culture medium. The results showed that both isozymes possessed almost identical capacity to oxidize tyrosine to dityrosine, isodityrosine and polytyrosine with the main difference being the pH optimum (pH 4 for the anionic and pH 7 for the cationic isozyme). Variation of reaction time after 1.5 h incubation had little effect on the quantity and quality of the oxidation products. On the other hand, increase of enzyme units correspondingly increased tyrosine-oxidation. The removal of heme and carbohydrate moieties from the holoenzyme arrested the reaction thereby suggesting the role played by these moieties in stabilizing the active site of peroxidase isoenzymes. Isolated cell wall extracts catalyzed the tyrosine-oxidation equally well as the purified peroxidase. Even though polyclonal antibodies against anionic peroxidase inhibited the in vitro tyrosine reaction they did not affect the tyrosine oxidation by the cell walls, while the cationic antibodies did.Abbreviations A.PRX anionic peanut peroxidase - C.PRX cationic peanut peroxidase - PcAb polyclonal antibodies - ELISA enzyme-linked-immuno-sorbent-assay - TFMS trifluoromethane sulfonic acid     

白背飞虱单克隆抗体的制备及其特性的研究

应用杂交瘤技术,制备出4株高度特异性的白背飞虱单克隆抗体,分别命名为WPH-1H9、WPH-2B6、WPH-2E12和WPH-3F12。这些抗体与其它8种昆虫未发生交叉反应,其中WPH-2B6可与白背飞虱所有虫态发生反应,其余3株只与卵和雌成虫发生反应。应用免疫双扩散法鉴定抗体类型及亚类,结果表明：WPH-2B6为IgG_2b亚类,其余均为IgG₁亚类。SDS-聚丙烯酰胺凝胶电泳和Western blot印迹分析表明,白背飞虱抗原主要由分子量分别为182、116、66.2及40 kD的4个多肽组成,其中WPH-2B6与182、116 kD的多肽结合,其余3株的单抗只与116 kD的多肽具有亲和性。最后对这些单克隆抗体在捕食作用研究中的应用潜力进行了讨论。     

马立克氏病毒单克隆抗体的研究

获得了4株分泌马立克氏病毒(MDV)特异性单克隆抗体(McAb)的杂交瘤细胞:4BS10对MDV所有毒株呈阳性反应;4CN8 对MDV血清1,3型毒株发生反应;2BN90和4CN24只对MDV血清1型毒株有阳性反应。3个McAb属IgG1,1个为IgG2b,均不中和MDV,免疫扩散试验也无沉淀线。对禽白血病毒(ALV)无交叉反应。 以2BN90和辣根过氧化物酶、异硫氰酸荧光素的结合物进行直接酶联免疫吸附试验和直接荧光抗体试验,均获得成功。抗体滴度前者为1/51,200,后者为1/640。对ALV无交叉反应。     

抗乙型肝炎病毒e抗原和核心抗原双特异性单克隆抗体的建立与应用

用基因工程技术在大肠杆菌中高效表达的乙型肝炎病毒核心抗原(内含高滴度的e抗原)免疫Balb/C小鼠,取免疫小鼠脾细胞与小鼠骨髓瘤细胞(Sp2/0)融合,获得两株分泌高滴度既抗-HBe又抗-HBc的双特异性杂交瘤细胞系。细胞培养上清液中抗体滴度为100～1000以上;免疫腹水中的抗体滴度为8万至10万以上,均属IgG2a亚类。细胞在实验室连续传代二年多,仍保持高效分泌抗体能力。此单克隆抗体与HBeAg或HBcAg的结合可被抗-HBc或抗-HBc阳性血清所抑制,竞争抑制率在85.9％～96.8％之间。用此单克隆抗体与HBe的β型单克隆抗体和抗HBc的α型单克隆抗体配对,可组装成检测HBeAg/抗-HBe和抗-HBc的诊断试剂,具有重要的应用价值。     

抗人IL-6单克隆抗体的制备及鉴定

用基因重组人IL-6免疫Balb/c小鼠,采用小鼠杂交瘤技术,筛选克隆到分泌抗人重组IL-6单克隆抗体的杂交瘤细胞株,并对其中2H₂、 1D₂ 和4B₄瘤细胞株进行了鉴定.其抗体类别均为IgG,亚类分别为IgG1和IgG2a.用多种细胞因子和无关蛋白的鉴别试验结果证实它们均特异地识别rhIL-6.免疫转染结果显示,该单抗识别分子质量为21 ku的IL-6单一条带.IL-6单克隆抗体的亲和常数K_aff= 1.62×10⁹ (mol/L)^-1.     

Monoclonal antibodies against human beta-glucocerebrosidase

Monoclonal antibodies were obtained against the membrane-bound lysosomal enzyme beta-glucocerebrosidase (acid beta-glucosidase), which is deficient in Gaucher's disease. BALB/c mice were immunized with homogeneous enzyme protein extracted from a sodium dodecyl sulphate/polyacrylamide gel. The mice were subsequently hyperimmunized with partially purified enzyme prior to fusion of spleen cells with myeloma cells. After fusion, 32 primary hybrid cell populations were obtained which continued to produce antibodies against beta-glucocerebrosidase after prolonged time of culture. All antibodies reacted with both native and denatured enzyme. Four primary cell populations were subcloned and the antibodies produced were characterized. The antibodies were all four of the IgG1 subclass. Three of these antibodies bind to protein A whereas one does not. The results of binding assays indicated that three of the antibodies react with the same antigenic domain (epitope 1), but the fourth with a different one (epitope 2). Probably two antigenic determinants are present in epitope 1 since one of the antibodies with specificity for epitope 1 is inactivated after iodination by the chloramine-T procedure whereas a second one is not.     

Progress and prospects in the use of peroxidase to study cell development

The need for peroxidase purification is stressed as a requirement for comparative studies on isoenzyme structure as well as for detailed investigations on biosynthesis. A single cationic protein possessing the major peroxidase activity was isolated from the medium in which peanut cells had grown. The antibodies raised against this pure protein were employed as a probe to study the site of synthesis of peroxidase in the cell as well as the proportion of total synthesized protein which was peroxidase. Structural studies on the purified isoenzymes suggest the presence of three gene loci for peroxidase in cultured peanut cells. The results are discussed together with potential assays for induction of this enzyme and the relationship to cell development.     

Immunological similarity of the cationic and the anionic peanut peroxidase isozymes

Antibodies against both the native and the deglycosylated cationic peanut peroxidase (C.PRX) were used to probe the structural relationship of this isozyme with its anionic counterpart. Not only the native but also the deglycosylated forms of the cationic and the anionic peroxidases reacted with both antibodies. The activity of the cationic isozymes was inhibited by anti-native C.PRX. Similar but nevertheless distinct immunodetection patterns resulted from reaction of the partially digested cationic and anionic peroxidase peptides with antibodies directed to the deglycosylated as well as to the native C.PRX, suggesting a similarity in their polypeptide structures.     

Evaluation of production and characterization of monoclonal antibodies to human IgG of four subclasses

Human IgG of four subclasses, semi-purified from pooled human serum by a series of DEAE ion exchange and protein A affinity chromatographies, were used as immunogens and initial screening antigens to produce subclass-specific and -restricted monoclonal antibodies (McAbs). These McAbs were bound to CNBr-activated Sepharose 4B and utilized in immunoaffinity chromatography to prepare four polyclonal human IgG subclasses of satisfactory purities, which were then used as final screening antigens. Subclass-specific McAbs thus chosen were further evaluated for subclass- and especially allotype-specificity using a panel of monoclonal IgG myeloma proteins with representative Gm markers for each subclass in micro enzyme-linked immunosorbent assay (ELISA). A total of 10 clones of subclass-specific McAbs (one for anti-IgG1, three anti-IgG2, two anti-IgG3, four anti-IgG4) were established. Among them, IgG2-specific clones of HG2-30F and HG2-56F, IgG3-specific HG3-7C and HG3-32C, and IgG4-specific HG4-53G McAbs were superior to the corresponding specificity standard McAbs chosen by the Human Immunoglobulins Subcommittee of the WHO/International Union of Immunological Societies (IUIS) in 1985. As allotype-specific McAbs, HG1-1E for G1m(az) and HG3-3B for G3m(b) were obtained. In micro ELISA of this study as well as all protocols of the previous WHO/IUIS collaborative study, antigens (myeloma IgG subclasses) were immobilized or fixed to a solid phase, resulting in possible variations in their epitope expressions. We developed a new assay system, micro radioimmunoassay (RIA), in which reactivities of McAbs against free IgG subclasses in solution can be evaluated. HG2-30F, having extremely high reactivities to coated IgG2 in micro ELISA, remarkably reduced its reactivities to free IgG2 in solution in micro RIA. Two other clones also showed some different reactivities in micro RIA and micro ELISA. We believe that this micro RIA is valuable for evaluation of McAbs reactivities against native human IgG subclasses in solution.     

抗黄曲霉尿酸氧化酶单克隆抗体的制备和初步鉴定

目的:制备抗黄曲霉尿酸氧化酶单克隆抗体。方法:采用杂交瘤技术,获得2株针对重组黄曲霉尿酸氧化酶(rUOX)的杂交瘤细胞McAb17和McAb3;采用盐析和A蛋白亲合层析柱纯化该抗体。结果:McAb17和McAb3的腹水效价达到1∶512000,纯化后获得纯度大于95%的单抗,抗体亚类(型)分别为IgG1/k型和IgG2a/k型;ELISA结果显示制备的单抗与rUOX和Rasburicase(商品化rUOX)可发生特异反应。结论:制备了抗黄曲霉尿酸氧化酶单克隆抗体McAb17和McAb3,为检测rUOX在动物体内的代谢变化提供了良好的实验基础。     

重组恶性疟原虫DNA质粒免疫小鼠制备单克隆抗体

用恶性疟原虫MSP131基因片段的重组质粒DNA直接免疫BALB/c小鼠,诱导产生体液,免疫后取脾细胞与SP2/0小鼠骨髓瘤细胞在PEG1450作用下进行融合,获得了2株能分泌抗恶性疟原虫MSP131单克隆抗体的小鼠杂交瘤细胞株9H9和8A2。用酶联免疫吸附试验检测,小鼠腹水抗体滴度最高为1∶10 000。经免疫球蛋白类型和亚类鉴定,2株杂交瘤细胞株均为IgG\-1\.蛋白免疫印迹试验表明,此单克隆抗体与MSP1\|31蛋白抗原有特异免疫反应,证明通过质粒DNA直接免疫小鼠可制备特异性单克隆抗体。     

Characterization of two forms of cationic peroxidase from cultured peanut cells.

Two forms of cationic peroxidase from peanut cells were differentiated by concanavalin A affinity chromatography. They differed in molecular mass as well as concanavalin A binding, leading to the initial suggestion that they represented two isozymes of peroxidase. However, similar values for the specific activity, Soret absorption, calcium content, and peptide molecular mass were observed for each of the forms. Therefore, the binding and nonbinding fractions most likely represent two molecular forms of cationic peanut peroxidase, rather than two distinct cationic isozymes. The difference between these two forms is discussed in terms of glycosylation. Through the amino acid sequence analysis of the formic acid treated peptide, the cationic isozyme has been shown to be identical in amino acid sequence to the cDNA clone PNC1.     

Characterization of epitopes on the cationic peanut peroxidase by four monoclonal antibodies

The epitope sites on the cationic peanut peroxidase were characterized by four monoclonal antibodies raised against this isozyme. Evidence is presented showing that the epitope for monoclonal antibody 1B is located on the polypeptide. Sensitivity of the epitopes recognized by 1M and 2F to 0.1M HCl, boiling, 10 mM periodate and trifluoromethane sulfonic acid treatment indicate that they occur at regions where oligosaccharides are linked to the polypeptide backbone. The antigenic specificity of 2A is, in addition, dependent on the conformation of the epitope site which is destroyed after partial proteolysis of the peroxidase.     

抗牛血清IgG单克隆抗体杂交瘤细胞株的建立及鉴定

用牛血清IgG免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤细胞SP2/0进行融合,用含山羊血清的培养基培养细胞,上清用间接ELISA法筛选。获得4株能稳定分泌抗牛血清IgG的单克隆抗体杂交瘤细胞株,分别命名为1G5、2A8、3F5、4C5。其中2A8为IgG2a,其余3株为IgG1;腹水单抗的ELISA滴度均超过10-5;除3F5株单抗与山羊血清有交叉反应外,1G5、2A8、4C5株与人、马、猪、羊、兔、豚鼠等血清均不发生交叉反应;4株单抗与制备病毒性疫苗的基质液呈阴性反应;4株单抗识别分子量为160kD的牛血清IgG的两个不同抗原表位;4株单抗相对亲和力大小依次为4C5>2A8>1G5>3F5,相对敏感度依次为2A8>4C5>3F5>1G5;4株杂交瘤细胞株的染色体计数均大于90条,连续培养三个月以及冷冻保存半年后复苏,细胞生长良好。使用这些单抗建立的双抗体夹心法检测生物制品中的残留牛血清IgG。     

Localization of epitopes of herpes simplex virus type 1 glycoprotein D.

We previously defined eight groups of monoclonal antibodies which react with distinct epitopes of herpes simplex virus glycoprotein D (gD). One of these, group VII antibody, was shown to react with a type-common continuous epitope within residues 11 to 19 of the mature glycoprotein (residues 36 to 44 of the predicted sequence of gD). In the current investigation, we have localized the sites of binding of two additional antibody groups which recognize continuous epitopes of gD. The use of truncated forms of gD as well as computer predictions of secondary structure and hydrophilicity were instrumental in locating these epitopes and choosing synthetic peptides to mimic their reactivity. Group II antibodies, which are type common, react with an epitope within residues 268 to 287 of the mature glycoprotein (residues 293 to 312 of the predicted sequence). Group V antibodies, which are gD-1 specific, react with an epitope within residues 340 to 356 of the mature protein (residues 365 to 381 of the predicted sequence). Four additional groups of monoclonal antibodies appear to react with discontinuous epitopes of gD-1, since the reactivity of these antibodies was lost when the glycoprotein was denatured by reduction and alkylation. Truncated forms of gD were used to localize these four epitopes to the first 260 amino acids of the mature protein. Competition experiments were used to assess the relative positions of binding of various pairs of monoclonal antibodies. In several cases, when one antibody was bound, there was no interference with the binding of an antibody from another group, indicating that the epitopes were distinct. However, in other cases, there was competition, indicating that these epitopes might share some common amino acids.     

抗H9亚型禽流感病毒血凝素单克隆抗体的制备和鉴定

目的:获得分泌抗H9亚型禽流感病毒(AIV)血凝素单克隆抗体的杂交瘤细胞。方法:以H9N2亚型AIV为免疫原,免疫6～8周龄雌性BALB/c小鼠,取其脾细胞与骨髓瘤细胞Sp2/0-Ag-14,在PEG4000的作用下进行细胞融合,通过血凝抑制(HI)试验筛选分泌抗H9亚型AIV血凝素单克隆抗体的杂交瘤细胞。结果:经过连续3～4次克隆化,获得能稳定分泌抗H9亚型AIV血凝素的单克隆抗体细胞系6株,分别命名为1B2、1C10、1G2、2B7、2E3和5E11。6株细胞培养上清HI效价为24～28,腹水HI效价为210～213。除1G2为IgM外,其余5株均为IgG1。Western blotting结果显示,1B2、1C10、2B7和2E3能与AIVH9蛋白在Mr为75000处反应,表明其是针对AIVH9亚型血凝素蛋白的单抗。特异性试验表明该6株单抗均只与H9亚型AIV发生特异性HI反应,而不与其他14个HA亚型的AIV及新城疫病毒、传染性支气管炎病毒发生交叉反应,显示出良好的特异性。结论:制备了针对H9亚型禽流感病毒血凝素的单克隆抗体,为禽流感的快速诊断和病毒的抗原性分析等奠定了基础。     

Core alpha1,3-fucose is a key part of the epitope recognized by antibodies reacting against plant N-linked oligosaccharides and is present in a wide variety of plant extracts

Carbohydrates have been suggested to account for some IgE cross- reactions between various plant, insect, and mollusk extracts, while some IgG antibodies have been successfully raised against plant glycoproteins. A rat monoclonal antibody raised against elderberry abscission tissue (YZ1/2.23) and rabbit polyclonal antiserum against horseradish peroxidase were screened for reactivity in enzyme-linked immunosorbent assay against a range of plant glycoproteins and extracts as well as neoglycoproteins, bee venom phospholipase, and several animal glycoproteins. Of the oligosaccharides tested, Man3XylFucGlcNAc2(MMXF3) derived from horseradish peroxidase was the most potent inhibitor of the reactivity of both YZ1/2.23 and anti- horseradish peroxidase to native horseradish peroxidase glycoprotein. The reactivity of YZ1/2. 23 and anti-horseradish peroxidase against Sophora japonica lectin was most inhibited by a neoglycoconjugate of bromelain glycopeptide cross-linked to bovine serum albumin, while the defucosylated form of this conjugate was inactive as an inhibitor. A wide range of plant extracts was found to react against YZ1/2.23 and anti-horseradish peroxidase, with particularly high reactivities recorded for grass pollen and nut extracts. All these reactivities were inhibitable with the bromelain glycopeptide/bovine serum albumin conjugate. Bee venom phospholipase and whole bee venom reacted weakly with YZ1/2.23 but more strongly with anti-horseradish peroxidase in a manner inhibitable with the bromelain glycopeptide/bovine serum albumin conjugate, while hemocyanin from Helix pomatia reacted poorly with YZ1/2.23 but did react with anti-horseradish peroxidase. It is concluded that the alpha1, 3-fucose residue linked to the chitobiose core of plant glycoproteins is the most important residue in the epitope recognized by the two antibodies studied, but that the polyclonal anti-horseradish peroxidase antiserum also contains antibody populations that recognize the xylose linked to the core mannose of many plant and gastropod N-linked oligosaccharides.      

Resolution and reconstitution of complex V of the mitochondrial oxidative phosphorylation system: properties and composition of the membrane sector

The antigenic properties of purified glycinin subunits were studied using antibodies prepared against them. Antisera against native glycinin did not react with the isolated subunits, and antibodies prepared against the purified subunits were not active against native glycinin. When native glycinin -was denatured, the antiglycinin immunoglobulins lost their ability to react with it, although the denatured complex was then recognized by antibodies against the purified subunits. Substantial structural rearrangement apparently occurred when the native complex was denatured and disaggregated. Acidic polypeptides A_1a, A_1b, and A₂ had similar determinants as judged by their reactions against A_1a and A_1a antisera. The reaction of the A₃ polypeptides with these antibodies was of lower intensity and in each case clear spurs of cross-reactivity were visible. No cross-reaction was detected between polypeptide A₄ and either anti-A_1a or A₂. Anti-A₃ antibodies reacted with each of the acidic polypeptides of glycinin, and distinct spurs of cross-reactivity were observed between A₃ vs A_1a, A₃ vs A₂, and A₃ vs A₄. B₁ Antisera developed a reaction of identity between basic polypeptides B₁ and B₂, but reacted very weakly with B₃ and B₄. The acidic and basic polypeptides of glycinin were immunologically unrelated. The results demonstrated that immunological tests would successfully differentiate some members of the family of acidic subunits, and other immunoglobulins would discriminate between members of the family of basic subunits.     

抗胆汁螺杆菌单克隆抗体的制备

目的制备抗胆汁螺杆菌单克隆抗体（McAbs）。方法用胆汁螺杆菌B2m株皮下免疫BALB/c小鼠,采用杂交瘤技术进行融合。以酶联免疫吸附实验（ELISA）筛选抗胆汁螺杆菌单克隆杂交瘤细胞株并初步鉴定其特异性;免疫印迹试验测定单抗所结合的抗原表位;免疫双向扩散试验确定IgG亚类;腹腔接种法、辛酸-硫酸铵盐析法大量制备、纯化单克隆抗体。结果经过ELISA筛选获得11个阳性杂交瘤细胞株,其效价最高达1：4×10^5以上,并与实验动物常见的15种病原菌呈阴性反应;IgG亚类为IgG2a和IgG2b;免疫印迹试验显示,6株（A-F）与胆汁螺杆菌大约相对分子质量（172、0、21、30、52、66）×10^3的抗原特异结合,5株（G-K）皆与胆汁螺杆菌、幽门螺杆菌等三种螺杆菌大约相对分子质量（52、82）×10^3的抗原呈阳性反应,表明A-F株针对的是胆汁螺杆菌特异性抗原,G-K株可能具有属特异性。结论筛选的单克隆抗体具有较高的特异性和敏感性,所结合的抗原为胆汁螺杆菌或螺杆菌的免疫优势抗原,为进一步的种、属生物学特性研究、菌株分型及血清学检测方法建立等奠定了基础。