Identification of secreted and membrane-bound bat immunoglobulin using a Microchiropteran-specific mouse monoclonal antibody

Bat immunity has received increasing attention because some bat species are being decimated by the fungal disease, White Nose Syndrome, while other species are potential reservoirs of zoonotic viruses. Identifying specific immune processes requires new specific tools and reagents. In this study, we describe a new mouse monoclonal antibody (mAb) reactive with Eptesicus fuscus immunoglobulins. The epitope recognized by mAb BT1-4F10 was localized to immunoglobulin light (lambda) chains; hence, the mAb recognized serum immunoglobulins and B lymphocytes. The BT1-4F10 epitope appeared to be restricted to Microchiropteran immunoglobulins and absent from Megachiropteran immunoglobulins. Analyses of sera and other E. fuscus fluids showed that most, if not all, secreted immunoglobulins utilized lambda light chains. Finally, mAb BT1-4F10 permitted the identification of B cell follicles in splenic white pulp. This Microchiropteran-specific mAb has potential utility in seroassays; hence, this reagent may have both basic and practical applications for studying immune process.     

Enzyme-linked immunosorbent assay to monitor colorectal carcinoma patients treated with a monoclonal antibody (17-1A)

An enzyme-linked immunosorbent assay (ELISA) was compared to a radioimmunoassay (RIA) for the detection and quantification of mouse monoclonal antibody MoAb 17-1A and for measurement of the host response (i.e. anti-mouse immunoglobulin in sera from patients receiving immunotherapy with MoAb 17-1A. Comparable sensitivity and reproducibility were noted with RIA and ELISA but ELISA was more rapid to perform than RIA. Thus quantitative ELISA compared favorably with the RIA for MoAb detection.     

抗人层黏连蛋白单克隆抗体的制备及特性鉴定

目的:制备抗人层黏连蛋白(laminin,LN)单克隆抗体(mAb)并鉴定其特性。方法:以人LN免疫BALB/c小鼠,采用杂交瘤技术制备抗人的mAb;同时采用间接ELISA法柃测mAb的腹水效价及mAb的相对亲和力;采用ELISA法鉴定mAb的Ig亚类、进行表位分析及特异性鉴定。结果:获得4株可分泌特异性mAb的杂交瘤细胞2A3、2C6、3G7和4H2,其腹水mAb 的效价为3.6 × 104～2.1×106;4株mAb的Ig亚类为IgG1,轻链均属κ型;相对亲和力2C6在1012以上,2A3、3G7和4H2在106以上;其中2株与1个表位结合,另2株与另外的1个表位结合。结论:成功地制备出抗人LN的mAb,为进一步研究LN在一些疾病中的作用提供了工具。     

An isotopic antiglobulin test for quantitation of anti-sheep red blood cell antibodies of individual Ig classes in mice bearing different IgCH haplotypes

An isotopic antiglobulin test (IAT) for anti-sheep red blood cell (SRBC) antibodies of different immunoglobulin (Ig) classes was developed and used to measure levels of IgM, IgA, IgG, IgG2a, IgG2b, and IgG3 anti-SRBC antibody in sera from 12 inbred strains of mice. Characterization of the Ig class specific heteroantisera prepared for use in this assay revealed substantial amounts of antibodies reactive with idiotypic and allotypic determinants of IgG1, IgG2a, IgG2b and IgA. Accordingly, class specific antibodies which do not discriminate among Ig molecules of different IgCH phenotypes were isolated from each heteroantiserum by absorption and elution from Ig's of selected strains. Levels of anti-SRBC antibody are expressed as units of antibody/ml relative to an anti-SRBC antiserum reference standard. The use of conversion factors (estimates of the relative reactivity of each anti-Ig reagent) allows quantitative comparisons within the between IgG subclasses. This method allows measurements of nanogram amounts of specific anti-SRBC antibodies of a single Ig class, and simultaneous measurements of antibody levels in 6 Ig classes from a single 30 microliter serum sample. Analysis of the responses of several strains of inbred mice indicates striking variations (5-31-fold) in the amounts and relative proportions of different Ig classes. The IgG subclass distributions observed appear to be associated with the IgCH but not the H-2 haplotypes of the strains studied.     

结肠癌相关抗原的制备及其临床意义

目的从培养的结肠癌细胞LOVO中纯化结肠癌相关抗原,探讨其在结肠癌患者血清中的表达。方法裂解结肠癌细胞LOVO,以抗结肠癌相关抗原单克隆抗体(mAb)4D10作为配基进行亲和层析纯化结肠癌相关抗原,SDS-PAGE电泳和Western blot进行鉴定,并用双抗夹心ELISA法检测该相关抗原在结肠癌患者及正常人血清中的表达。结果纯化所获与4D10特异结合的结肠癌相关抗原,其相对分子质量(Mr)约为65000,该抗原由Mr约为30000和35000两种亚基组成。人血清检测实验表明,该抗原在结肠癌患者血清中有较高的表达,与正常人血清相比存在显著的统计学差异(P<0.01)。结论利用mAb4D10进行免疫亲和层析,从结肠癌细胞LOVO中获得纯化的肿瘤相关抗原,该抗原有可能在临床上为结肠癌的诊断提供一定的参考价值。     

Long-lasting unresponsiveness to polyclonal T cell-binding immunoglobulins

We have shown that mice after a single injection of anti-T cell antibody followed by multiple injections of a second xeno-, allo- or syngeneic anti-T cell antibody differing from the former in species origin developed specific, long-lasting tolerance to the second antibody. To characterize the mechanism of this anti-antibody unresponsiveness and the modalities accompanying the preinjection step, we injected mice with anti-pan T, anti-CD4 or anti-CD8 monoclonal antibodies, followed by multiple injections of polyclonal rabbit anti-mouse thymocyte globulin (RbATG). Our observations indicate that: (i) Depletion of CD4+ cells is the most important factor for tolerance induction to subsequently injected RbATG. Non-depleting mAb were less effective, and antibody-induced CD4 modulation or blockade were inconsequential. (ii) The prevention of anti-antibody responses involves specific B cell tolerance, as shown by suppression of anti-RbATG but not anti-bovine serum albumin (BSA) antibodies after challenge of tolerant mice with RbATG-BSA conjugates. (iii) Suppression of anti-antibody responses involves T cell unresponsiveness rather marginally, as demonstrated by in vitro spleen cell restimulation with RbATG and in vivo antibody response to RbATG-fluorescein isothiocyanate hapten conjugate. (iv) Analysis of isotypes of anti-RbATG anti-bodies does not suggest alterations in Th1/Th2 tuning as being responsible for this kind of tolerance. (v) Over 150-day survival of fully allogeneic skin grafts (CBA-to-C57BL/6) was observed in mice preinjected with anti pan-T or anti-CD4 mAb followed by RbATG. Mice treated with anti-CD4 mAb alone rejected allografts within 21 days and induced anti-antibodies. Taken together, our experiments suggest B cell tolerance as main mechanism in this type of acquired long-term humoral unresponsiveness to foreign, polyclonal, T cell-binding immunoglobulins.     

抗人可溶性间皮素相关蛋白单克隆抗体的制备及特性鉴定

目的:制备鼠抗人可溶性间皮素相关蛋白(SMR)的单克隆抗体(mAb),鉴定其生物学特性。方法:应用计算机通过综合预测对间皮素(MSLN)进行B-细胞表位预测。合成相应肽段并免疫BALB/c小鼠,采用杂交瘤技术制备mAb,利用免疫细胞化学和Western blot分析对所制备的mAb进行鉴定。结果:综合预测方法分析间皮素的抗原表位可能于153-162、282-292及471-481氨基酸残基或其附近,选择性合成了可能性最高的位于471-481氨基酸残基的可溶性间皮素相关蛋白表位,制备了mAb(2H10),经免疫细胞化学和Western blot分析该抗体具有较高的特异性。结论:成功地制备了鼠抗人可溶性间皮素相关蛋白的mAb(2H10),该抗体具有较高的特异性,为进一步利用ELISA对可溶性间皮素相关蛋白进行检测奠定了基础。     

A rat anti-mouse kappa chain specific monoclonal antibody, 187.1.10: purification, immunochemical properties and its utility as a general second-antibody reagent

A rat IgG1 monoclonal antibody, produced by hybridoma 187.1.10, exhibits specificity for mouse immunoglobulins containing kappa light chains (Yelton et al., 1981). The 187.1.10 hybridoma cell line secreted upwards of 200 micrograms/ml of monoclonal antibody in tissue culture and the secreted product was purified in a single step by antigen-immunoadsorbent affinity chromatography. The homogeneity of the purified 187.1.10 protein was determined by isoelectrofocusing and SDS gel electrophoresis. Equilibrium binding analyses of the radioiodinated 187.1.10 antibody indicated a strong interaction with its antigen of KA = 2 X 10(9) l/mole. The 187.1.10 antibody did not readily bind to Staph. aureus protein A unless it was complexed with antigen. The binding of immune complexes of 187.1.10 to protein A was shown to be dependent on the Fc region of the antigen. The utility of the 187.1.10 monoclonal antibody as a general second antibody reagent for studying mouse immunoglobulins was demonstrated in a rapid solid phase immunoprecipitation assay to detect and analyze radioiodinated membrane proteins of a human cytotoxic T cell line.     

Measurement of BK papovavirus IgG and IgM by radioimmunoassay (RIA)

Current techniques for the measurement of BK papovavirus (BKV) specific IgM include sucrose density gradient centrifugation followed by hemagglutination inhibition (HAI) or indirect immunofluorescent (IF) staining of BKV infected cells using a fluorescein conjugated anti-human IgM antibody. These techniques are cumbersome and labor intensive and do not lend themselves to testing large numbers of sera. A solid phase radioimmunoassay (RIA) was developed to facilitate the measurement of BKV IgG and IgM in large numbers of sera. Solid phase antigen was prepared by adsorbing CsCl purified BKV antigen to polyvinyl chloride microtiter plates. Following reaction with serum, bound immunoglobulin was detected with iodinated goat anti-human IgG or IgM. RIA for the measurement of BKV IgG was sensitive with titers approaching 10⁻⁶. Determination of IgG titers by RIA and HAI showed good agreement (P < 0.01, correlation coefficient = 0.74). Measurement of BKV IgM was not affected by the presence of BKV IgG as evidenced by sucrose density gradient fractionation of IgM positive sera, removal of IgG by treatment with S. aureus protein A, and addition of BKV IgG to BKV IgM. Rheumatoid factor (RF) gave false positive IgM titers in the presence of BKV IgG when RF titers were ≥ 1:640 by latex agglutination testing and BKV IgG levels exceed 1:256 by HAI. False positives due to RF could be eliminated by treatment of sera with sheep anti—human IgG antisera. RIA for BKV IgM was specific as sera containing JCV-, cytomegalovirus (CMV)-, rubella-, or hepatitis B core antibody (anti HBc)—IgM were negative by RIA. RIA detected BKV IgM in several sera from renal dialysis or allograft palienls with titers ranging from 1:400 to 1:128,000 and demonstrated that BKV IgM persisted in sera of renal allograft patients for as long as 343 days post transplantation.     

Monoclonal radioimmunoassay for hepatitis B surface antigen in sera of children with acute leukemia

Hepatitis B surface antigen (HBsAg) was detected by a monoclonal antibody radioimmunoassay in sera from five of 43 children (11.6%) with acute leukemia, who were negative by conventional assay. None of the nine positive sera had evidence of reactivity for HBV-DNA or DNA-polymerase activity. No correlation was found between the presence of HBsAg in serum by monoclonal RIA and the behaviour of anti-viral antibodies. Twenty-two children could be studied for liver HBsAg by immunofluorescence, and nine of them (40.9%) were positive, including three patients having HBsAg reactivity in serum. These data indicate that monoclonal antibodies increase the sensitivity of RIA for the detection of serum HBsAg in children with acute leukemia, who previously have frequently been found to have an atypical hepatitis B virus (HBV) serology.     

异嗜性抗体对甲状腺功能测定干扰作用的研究

目的 研究异嗜性抗体(HAb)对甲状腺功能测定的干扰,分析其临床特点并探讨减少和排除干扰作用的方法.方法 2008年5月-2009年6月,在我院选择296例甲状腺功能测定表现为血浆TSH水平不适当增高的患者(FT3、FT4测定采用固相放射免疫分析方法,TSH测定采用免疫放射分析方法-IRMA),其中9例疑诊HAb增多症...     

人细胞角蛋白19片段单克隆抗体的制备和鉴定

目的制备人细胞角蛋白19片段(CYFRA21-1)的单克隆抗体(mAb),并对其免疫特性进行鉴定。方法用重组CYFRA21-1蛋白免疫BALB/c小鼠,取血清效价最高小鼠的脾脏细胞与小鼠骨髓瘤细胞SP2/0融合,筛选出阳性杂交瘤细胞株,进行亚克隆,并鉴定分泌抗体亚型;制备小鼠腹水,用protein G从腹水中纯化出CYFRA21-1的mAb;用间接ELISA测定mAb的效价,Western blot和竞争ELISA对mAb的免疫特性进行检测,竞争ELISA对mAb的临床应用性进行评价。结果获得2G8和12G7两株能稳定分泌人CYFRA21-1mAb的杂交瘤细胞株,其分泌抗体都为轻链为κ的IgG1;两株mAb都能特异识别人血清中的CYFRA21-1,效价分别为1×10-6和5×10-7;检测134份血清样本CYFRA21-1含量的结果与北京源德生物医学工程有限公司CYFRA21-1化学发光法定量检测试剂盒检测结果的相关性分别为y=0.8167x+0.3755(r=0.9772)和y=0.8142x+0.3655(r=0.9770)。结论成功制备两株人CYFRA21-1的特异mAb,为后期人血清CYFRA21-1定量测定试剂盒的完全国产化奠定了良好的基础。     

肝癌候选标志物HCCR单克隆抗体的制备和鉴定

目的:制备肝癌候选标志物HCCR蛋白的单克隆抗体(mAb).方法:重组表达HCCR-1167-360蛋白用于动物免疫,用含有HCCR蛋白抗原表位YLGTRR的重组蛋白(Ep-HCCR)检测血清抗体效价及筛选阳性克隆.通过ELISA、Western blot、免疫荧光和免疫组化方法鉴定制备的HCCR抗体的性质.结果:获得1株分泌HCCR抗体杂交瘤细胞株,通过ELISA方法测定抗体的亲和力常数为5.4×106L/mol;Western blot结果显示,该抗体能特异识别肝癌HepG2细胞中HCCR-1和HCCR-2蛋白;免疫荧光检测显示,HCCR蛋白主要分布在细胞质和细胞膜中;免疫组化检测到肝癌组织中有HCCR蛋白表达但在正常组织中没有.结论:成功制备了1株抗HCCR特异性mAb,为建立基于HCCR的肝癌检测方法奠定了基础.     

Detection of circulating immune complexes with a Raji cell enzyme immunoassay

The primary aim of this work was to produce specific monoclonal antibodies to human growth hormone (hGH) for use in a diagnostic RIA of hGH levels in serum. Three different schedules were used for immunization of BALB/c mice and the splenocytes from each mouse were fused with myeloma cells Sp 2/0 Ag 14. Each fusion resulted in the production of hundreds of hybridomas secreting hGH-directed antibodies. Six antibodies have been fully characterized and have been grouped into pairs which recognize 3 different epitopes on the hGH molecule. One pair exhibits no cross reaction with the structurally related placental hormone, human placental lactogen (hPL), a second pair has low cross reaction with hPL (1.6-3%) and a third pair reacts equally well with hGH and hPL indicating binding to a common epitope in the 2 molecules. The highest affinity antibody, 74/6, which has an affinity constant of 4.4 X 10(10) l/mol and 3% cross-reactivity with hPL, has been used to establish a RIA for serum hGH measurements. Evidence is provided that hGH levels measured in this assay correlate well with those obtained in a conventional rabbit antiserum assay.     

Engineering of a recombinant trivalent single-chain variable fragment antibody directed against rabies virus glycoprotein G with improved neutralizing potency

Human and equine rabies immunoglobulins are currently available for passive immunization against rabies. However, these are hampered by the limited supply and some drawbacks. Advances in antibody engineering have led to overcome issues of clinical applications and to improve the protective efficacy. In the present study, we report the generation of a trivalent single-chain Fv (scFv50AD1-Fd), that recognizes the rabies virus glycoprotein, genetically fused to the trimerization domain of the bacteriophage T4 fibritin, termed ‘foldon’ (Fd). scFv50AD1-Fd was expressed as soluble recombinant protein in bacterial periplasmic space and purified through affinity chromatography. The molecular integrity and stability were analyzed by polyacrylamide gradient-gel electrophoresis, size-exclusion chromatography and incubation in human sera. The antigen-binding properties of the trimeric scFv were analyzed by direct and competitive-ELISA. Its apparent affinity constant was estimated at 1.4 ± 0.25 × 10⁹ M⁻¹ and was 75-fold higher than its monovalent scFv (1.9 ± 0.68 × 10⁷ M⁻¹). The scFv50AD1-Fd neutralized rabies virus in a standard in vitro and in vivo neutralization assay. We showed a high neutralization activity up to 75-fold compared with monovalent format and the WHO standard serum. The gain in avidity resulting from multivalency along with an improved biological activity makes the trivalent scFv50AD1-Fd construct an important reagent for rabies protection. The antibody engineering approach presented here may serve as a strategy for designing a new generation of anti-rabies for passive immunotherapy.     

An ELISA for the detection of rhinovirus specific antibody in serum and nasal secretion

An enzyme-linked immunosorbent assay (ELISA) which detects rhinovirus specific antibody in human sera and nasal secretions, has been developed. This sandwich ELISA utilizes a rabbit antirhinovirus hyperimmune serum as the capture antibody and was found to be very sensitive, detecting rhinovirus specific antibody in the serum at dilutions of 1:10(6) and 1:10(3.5) for IgG and IgA immunoglobulins, respectively. Thus, this new assay is 10(2)-10(4) times more sensitive than our standard neutralization test. Furthermore, this increase in sensitivity has enabled us to reliably detect rhinovirus specific immunoglobulins in unconcentrated nasal washings, which are thought to be particularly important for protection against rhinovirus reinfection. A preliminary study of the immune response in human volunteers challenged with rhinovirus using this new ELISA system is presented and further applications and potential of the method are also discussed.     

抗rhNDPK-A单克隆抗体的制备及鉴定

目的 :研制抗rhNDPK A (recombinanthumannucleosidediphosphatekinase A)单克隆抗体 (mAb) ,并鉴定其特性。 方法 :以纯化的rhNDPK A免疫BALB/c小鼠 ,采用杂交瘤技术制备抗rhNDPK AmAb ;用免疫双扩散鉴定Ig亚类 ;West ernblot鉴定mAb的特异性 ;间接ELISA检测mAb的腹水效价、亲和常数 ,并进行表位分析。结果 :获得 6株可分泌特异性mAb的抗rhNDPK A的杂交瘤细胞系 2D9、8C7、13E2、15D9、15E3和 2 0D9,Ig亚类均为IgG1;其效价为 1× 10 -4～5× 10 -6;亲和常数为 4 .5× 10 -9～ 2 .8× 10 -10 mol/L ;共有3个抗原表位。结论 :获得抗rhNDPK A的mAb ,为进一步用于临床诊断和实验研究创造了条件     

Serodiagnosis of infectious mononucleosis with a bovine erythrocyte glycoprotein

A glycoprotein from bovine erythrocyte membrane was evaluated in two immunoassays as a reagent for the serodiagnosis of infectious mononucleosis (IM). We previously reported that a partially purified preparation of this glycoprotein, when attached to latex beads, agglutinated in the presence of IM heterophile antibody. In the present study, we used a highly purified form of the glycoprotein both as an agglutinating reagent, covalently bound to latex, and in a solid-phase sandwich-type radioimmunoassay (RIA) for IM antibody detection in a larger population of patients. We tested serum samples from college students with symptoms suggestive of IM with the latex reagent (143 samples) and with the RIA (245 samples). Correlation of these two tests, both with each other and with the classical differentially absorbed, agglutination tests for Paul-Bunnell antibody in IM sera, using fresh sheep or horse cells, was excellent (greater than 97% agreement). The new tests also corresponded in most cases with a rapid, unabsorbed preserved horse erythrocyte slide test. However, in this study of 245 samples, both apparent false-positives (5 samples) and apparent false-negatives (3 samples) were observed with this slide test. In conclusion, we found that the bovine glycoprotein as a reagent can facilitate the diagnosis of IM, giving results comparable to those with erythrocyte agglutination tests on differentially absorbed sera. The advantages are ease and speed of performance (latex test), potential for automation (RIA test), stability and uniformity of the glycoprotein reagent (latex and RIA tests), and most importantly, the ability to use unabsorbed sera (latex and RIA tests).     

A monoclonal antibody specific for a carbohydrate epitope recognizes an IgE-binding determinant shared by taxonomically unrelated allergenic pollens

Carbohydrate epitopes are capable of binding human IgE from allergic subjects and these epitopes play a role in the cross-reactivity between allergens from unrelated sources. A monoclonal antibody (5E6), specific for a carbohydrate epitope detectable on components of Cupressus arizonica pollen extract, has been produced and characterized. To study the relationship between the epitopes recognized by the monoclonal antibody and by IgE from allergic subjects. To investigate the presence of such carbohydrate IgE determinant in extracts from 21 pollen species belonging to 16 taxonomically related and unrelated families, by means of the monoclonal antibody. IgG-depleted fraction from protein G-purified human allergic serum was obtained. The monoclonal antibody and the IgE from the purified fraction were tested on two glycoproteins, polyamine oxidase and ascorbate oxidase, adsorbed on the ELISA plates. The relationship between the monoclonal- and the IgE-recognized epitopes was investigated by ELISA-competition experiments. Analysis of the distribution of this carbohydrate epitope was performed by direct binding of the monoclonal antibody onto the various extracts. The monoclonal antibody and the IgE were able to bind carbohydrate epitopes on the two plant glycoproteins, ascorbate oxidase and polyamine oxidase. Polyamine oxidase shows only one N-glycosilation site whose carbohydrate moiety seems to be composed of a branched chain of seven ordered sugars, i.e. two N-acetyl-D-glucosamine-, three mannose-, one fucose- and one xylose-residues. This structure bears the epitope recognized by mAb 5E6. Human IgE from the IgG-depleted fraction were found capable of inhibiting the monoclonal antibody binding. The allergenic epitope identified was shared by a large number of extracts with different levels of reactivity (OD490 ranging from 0.110 to 2.060). Our data support the finding that a monoclonal antibody specific for a carbohydrate epitope of Cupressus arizonica pollen extract detects an epitope which is also recognized by IgE from allergic subjects. This characterized reagent could be a useful tool for studying distribution of cross-reactive carbohydrate determinants in allergenic pollen extracts and their components.     

Humane Anti-Mausimmunglobulin-Antikörper als Störfaktoren der TSH-Bestimmung

Summary Monoclonal murine antibodies are increasingly used for immunotherapy and in vivo diagnostic procedures such as immunoscintigraphy. The therapeutic or diagnostic reagent however, is a foreign antigen, which may induce host reactivity. This may interfere with the therapeutic or diagnostic reagent in vivo, resulting in a loss of efficacy or the necessity to increase dosages. In addition, there is an important interference to in vitro immunoassays detecting specific antigens utilizing murine monoclonal antibodies. In the present study, sera of patients who had undergone a therapeutic trial using 140 mg of an anti-CD4 antibody, were investigated. Human anti-murine-immunoglobulin-antibodies (HAMA) were detected 2–3 weeks after treatment was started and reached maximal amounts of 0.8 g/ml after a single and 2 g/ml after a repeated treatment course. Parallely raised values of TSH were found in sera containing HAMAs of more than 0.3 g/ml. Elevations of TSH levels up to 13 U/ml were most pronounced after a repeated trial of the murine antibody and were detectable up to 20 weeks.

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Abkürzungen (HAMA) Humane Anti-Mausimmunglobulin-Antikörper - (mAK) Monoklonale Antikörper - (TSH) Thyreotropin - (RIA) Radioimmunoassay - (IRMA) Immunoradiometrischer Assay - (ELISA) Enzymimmunoassay