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Sample records for antibody conjugate dota-morab-003

  1. Antibody Drug Conjugates: Preclinical Considerations.

    Science.gov (United States)

    Bornstein, Gadi G

    2015-05-01

    The development path for antibody drug conjugates (ADCs) is more complex and challenging than for unmodified antibodies. While many of the preclinical considerations for both unmodified and antibody drug conjugates are shared, special considerations must be taken into account when developing an ADC. Unlike unmodified antibodies, an ADC must preferentially bind to tumor cells, internalize, and traffic to the appropriate intracellular compartment to release the payload. Parameters that can impact the pharmacological properties of this class of therapeutics include the selection of the payload, the type of linker, and the methodology for payload drug conjugation. Despite a plethora of in vitro assays and in vivo models to screen and evaluate ADCs, the challenge remains to develop improved preclinical tools that will be more predictive of clinical outcome. This review will focus on preclinical considerations for clinically validated small molecule ADCs. In addition, the lessons learned from Mylotarg®, the first in class FDA-approved ADC, are highlighted.

  2. Antibody conjugate radioimmunotherapy of superficial bladder cancer

    International Nuclear Information System (INIS)

    Perkins, Alan; Hopper, Melanie; Murray, Andrea; Frier, Malcolm; Bishop, Mike

    2002-01-01

    The administration of antibody conjugates for cancer therapy is now proving to be of clinical value. We are currently undertaking a programme of clinical studies using the monoclonal antibody C 595 (gG3) which reacts with the MUC1 glycoprotein antigen that is aberrantly expressed in a high proportion of bladder tumours. Radio immuno conjugates of the C 595 antibody have been produced with high radiolabelling efficiency and immuno reactivity using Tc-99 m and In-111 for diagnostic imaging, and disease staging and the cytotoxic radionuclides Cu-67 and Re-188 for therapy of superficial bladder cancer. A Phase I/II therapeutic trail involving the intravesical administration of antibody directly into the bladder has now begun. (author)

  3. Antibody-Conjugated Nanoparticles for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Manuel Arruebo

    2009-01-01

    Full Text Available Nanoscience and Nanotechnology have found their way into the fields of Biotechnology and Medicine. Nanoparticles by themselves offer specific physicochemical properties that they do not exhibit in bulk form, where materials show constant physical properties regardless of size. Antibodies are nanosize biological products that are part of the specific immune system. In addition to their own properties as pathogens or toxin neutralizers, as well as in the recruitment of immune elements (complement, improving phagocytosis, cytotoxicity antibody dependent by natural killer cells, etc., they could carry several elements (toxins, drugs, fluorochroms, or even nanoparticles, etc. and be used in several diagnostic procedures, or even in therapy to destroy a specific target. The conjugation of antibodies to nanoparticles can generate a product that combines the properties of both. For example, they can combine the small size of nanoparticles and their special thermal, imaging, drug carrier, or magnetic characteristics with the abilities of antibodies, such as specific and selective recognition. The hybrid product will show versatility and specificity. In this review, we analyse both antibodies and nanoparticles, focusing especially on the recent developments for antibody-conjugated nanoparticles, offering the researcher an overview of the different applications and possibilities of these hybrid carriers.

  4. Antibody conjugate radioimmunotherapy of superficial bladder cancer

    Directory of Open Access Journals (Sweden)

    Alan Perkins

    2002-09-01

    Full Text Available The administration of antibody conjugates for cancer therapy is now proving to be of clinical value. We are currently undertaking a programme of clinical studies using the monoclonal antibody C595 (IgG3 which reacts with the MUC1 glycoprotein antigen that is aberrantly expressed in a high proportion of bladder tumours. Radioimmunoconjugates of the C595 antibody have been produced with high radiolabelling efficiency and immunoreactivity using Tc-99m and In-111 for diagnostic imaging, and disease staging and the cytotoxic radionuclides Cu-67 and Re-188 for therapy of superficial bladder cancer. A Phase I/II therapeutic trail involving the intravesical administration of antibody directly into the bladder has now begun.A administração de anticorpos conjugados para o tratamento do câncer está agora provando ser de valor clínico. Nós estamos atualmente realizando um programa de estudos clínicos usando o anticorpo monoclonal C595 (IgG3 que reage com a glicoproteína MUC1 que está aberrantemente expressa numa alta proporção de tumores de bexiga. Tem sido produzidos radioimunoconjugados do anticorpo C595, com alta eficiência de radiomarcação e a imunoreatividade, usando-se o Tc-99m e In-111, para o diagnóstico por imagem e estagiamento de doenças. Tem sido produzidos, também, radionuclídeos citotóxicos (Cu-67 e Re-188 para o tratamento de cânceres superficiais de bexiga. A fase terapêutica I/II já se iniciou, envolvendo a administração intravesical do anticorpo diretamente na bexiga.

  5. Methods to Design and Synthesize Antibody-Drug Conjugates (ADCs

    Directory of Open Access Journals (Sweden)

    Houzong Yao

    2016-02-01

    Full Text Available Antibody-drug conjugates (ADCs have become a promising targeted therapy strategy that combines the specificity, favorable pharmacokinetics and biodistributions of antibodies with the destructive potential of highly potent drugs. One of the biggest challenges in the development of ADCs is the application of suitable linkers for conjugating drugs to antibodies. Recently, the design and synthesis of linkers are making great progress. In this review, we present the methods that are currently used to synthesize antibody-drug conjugates by using thiols, amines, alcohols, aldehydes and azides.

  6. Recent advances in the construction of antibody-drug conjugates

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    Chudasama, Vijay; Maruani, Antoine; Caddick, Stephen

    2016-02-01

    Antibody-drug conjugates (ADCs) comprise antibodies covalently attached to highly potent drugs using a variety of conjugation technologies. As therapeutics, they combine the exquisite specificity of antibodies, enabling discrimination between healthy and diseased tissue, with the cell-killing ability of cytotoxic drugs. This powerful and exciting class of targeted therapy has shown considerable promise in the treatment of various cancers with two US Food and Drug Administration approved ADCs currently on the market (Adcetris and Kadcyla) and approximately 40 currently undergoing clinical evaluation. However, most of these ADCs exist as heterogeneous mixtures, which can result in a narrow therapeutic window and have major pharmacokinetic implications. In order for ADCs to deliver their full potential, sophisticated site-specific conjugation technologies to connect the drug to the antibody are vital. This Perspective discusses the strategies currently used for the site-specific construction of ADCs and appraises their merits and disadvantages.

  7. Data on atherosclerosis specific antibody conjugation to nanoemulsions

    Directory of Open Access Journals (Sweden)

    Geoffrey Prévot

    2017-12-01

    Full Text Available This article present data related to the publication entitled “Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging” (Prévot et al., 2017 [1]. Herein we describe the engineering in the baculovirus-insect cell system and purification processes of the human scFv-Fc TEG4-2C antibody, specific of platelets within the atheroma plaque. For molecular targeting purpose, atheroma specific antibody was conjugated to nanoemulsions (NEs using a heterobifunctional linker (DSPE-PEG-maleimide. Atheroma labelling was assayed by immunochemistry on arterial sections from rabbits.

  8. Anti-transferrin receptor antibody and antibody-drug conjugates cross the blood-brain barrier

    International Nuclear Information System (INIS)

    Friden, P.M.; Walus, L.R.; Musso, G.F.; Taylor, M.A.; Malfroy, B.; Starzyk, R.M.

    1991-01-01

    Delivery of nonlipophilic drugs to the brain is hindered by the tightly apposed capillary endothelial cells that make up the blood-brain barrier. The authors have examined the ability of a monoclonal antibody (OX-26), which recognizes the rat transferrin receptor, to function as a carrier for the delivery of drugs across the blood-brain barrier. This antibody, which was previously shown to bind preferentially to capillary endothelial cells in the brain after intravenous administration, labels the entire cerebrovascular bed in a dose-dependent manner. The initially uniform labeling of brain capillaries becomes extremely punctate ∼ 4 hr after injection, suggesting a time-dependent sequestering of the antibody. Capillary-depletion experiments, in which the brain is separated into capillary and parenchymal fractions, show a time-dependent migration of radiolabeled antibody from the capillaries into the brain parenchyma, which is consistent with the transcytosis of compounds across the blood-brain barrier. Antibody-methotrexate conjugates were tested in vivo to assess the carrier ability of this antibody. Immunohistochemical staining for either component of an OX-26-methotrexate conjugate revealed patterns of cerebrovascular labeling identical to those observed with the unaltered antibody. Accumulation of radiolabeled methotrexate in the brain parenchyma is greatly enhanced when the drug is conjugated to OX-26

  9. Oriented conjugation of single-domain antibodies and quantum dots.

    Science.gov (United States)

    Brazhnik, Kristina; Nabiev, Igor; Sukhanova, Alyona

    2014-01-01

    Nanoparticle-based biodetection routinely employs monoclonal antibodies (mAbs) for targeting. However, the large size of mAbs limits the number of ligands per nanoparticle and severely restricts the bioavailability and distribution of these probes in a sample. Furthermore, conventional conjugation techniques provide nanoprobes with irregular orientation of mAbs on the nanoparticle surface and often provoke mAb unfolding. Here, we describe a protocol for engineering a new generation of ultrasmall diagnostic nanoprobes through oriented conjugation of semiconductor quantum dots (QDs) with 13 kDa single-domain antibodies (sdAbs) derived from llama immunoglobulin G (IgG). The sdAbs are conjugated with QDs in a highly oriented manner via an additional cysteine residue specifically integrated into the sdAb C-terminus. The resultant nanoprobes are <12 nm in diameter, ten times smaller in volume compared to the known alternatives. They have been proved highly efficient in flow cytometry and immunuhistochemical diagnostics. This approach can be easily extended to other semiconductor and plasmonic nanoparticles.

  10. Metal chelate conjugated monoclonal antibodies, wherein the metal is an α emitter

    International Nuclear Information System (INIS)

    Gansow, O.A.; Strand, M.

    1984-01-01

    Methods of manufacturing and purifying metal chelate conjugated monoclonal antibodies are described, wherein the chelated metal emits alpha radiation. The conjugates are suited for therapeutic uses being substantially free of nonchelated radiometal. (author)

  11. Conjugation effects on antibody-drug conjugates: evaluation of interaction kinetics in real time on living cells.

    Science.gov (United States)

    Bondza, Sina; Stenberg, Jonas; Nestor, Marika; Andersson, Karl; Björkelund, Hanna

    2014-11-03

    Antibody-drug conjugates (ADC) have shown promising effects in cancer therapy by combining the target specificity of an antibody with the toxicity of a chemotherapeutic drug. As the number of therapeutic antibodies is significantly larger than those used as ADCs, there is unused potential for more effective therapies. However, the conjugation of an additional molecule to an antibody may affect the interaction with its target, altering association rate, dissociation rate, or both. Any changes of the binding kinetics can have subsequent effects on the efficacy of the ADCs, thus the kinetics are important to monitor during ADC development and production. This paper describes a method for the analysis of conjugation effects on antibody binding to its antigen, using the instrument LigandTracer and a fluorescent monovalent anti-IgG binder denoted FIBA, which did not affect the interaction. All measurements were done in real time using living cells which naturally expressed the antigens. With this method the binding profiles of different conjugations of the therapeutic anti-EGFR antibody cetuximab and the anti-CD44v6 antibody fragment AbD15171 were evaluated and compared. Even comparatively small modifications of cetuximab altered the interaction with the epidermal growth factor receptor (EGFR). In contrast, no impact on the AbD15171-CD44v6 interaction was observed upon conjugation. This illustrates the importance to study the binding profile for each ADC combination, as it is difficult to draw any general conclusion about conjugation effects. The modification of interaction kinetics through conjugation opens up new possibilities when optimizing an antibody or an ADC, since the conjugations can be used to create a binding profile more apt for a specific clinical need.

  12. Process development of a FGF21 protein-antibody conjugate.

    Science.gov (United States)

    Dirksen, Anouk; Davis, Keith A; Collins, Joe T; Bhattacharya, Keshab; Finneman, Jari I; Pepin, Erin L; Ryczek, Jeffrey S; Brown, Paul W; Wellborn, William B; Mangalathillam, Ratish; Evans, Brad P; Pozzo, Mark J; Finn, Rory F

    2017-09-26

    A scalable, viable process was developed for the Fibroblast Growth Factor 21 (FGF21) protein-antibody conjugate, CVX-343, an extended half-life therapeutic for the treatment of metabolic disease. CVX-343 utilizes the CovX antibody scaffold technology platform that was specifically developed for peptide and protein half-life extension. CVX-343 is representative of a growing number of complex novel peptide- and protein-based bioconjugate molecules currently being explored as therapeutic candidates. The complexity of these bioconjugates, assembled using well-established chemistries, can lead to very difficult production schemes requiring multiple starting materials and a combination of diverse technologies. Key improvements had to be made to the original CVX-343 Phase 1 manufacturing process in preparation for Phase 3 and commercial manufacturing. A strategy of minimizing FGF21 A129C dimerization and stabilizing the FGF21 A129C Drug Substance Intermediate (DSI), linker, and activated FGF21 intermediate was pursued. The use of tris(2-carboxyethyl)phosphine (TCEP) to prevent FGF21 A129C dimerization through disulfide formation was eliminated. FGF21 A129C dimerization and linker hydrolysis were minimized by formulating and activating FGF21 A129C at acidic instead of neutral pH. An activation use test was utilized to guide FGF21 A129C pooling in order to minimize misfolds, dimers, and misfolded dimers in the FGF21 A129C DSI. After final optimization of reaction conditions, a process was established that reduced the consumption of FGF21 A129C by 36% (from 4.7 to 3.0 equivalents) and the consumption of linker by 55% (from 1.4 to 0.95 equivalents for a smaller required amount of FGF21 A129C ). The overall process time was reduced from ∼5 to ∼3 days. The product distribution improved from containing ∼60% to ∼75% desired bifunctionalized (+2 FGF21) FGF21-antibody conjugate in the crude conjugation mixture and from ∼80% to ∼85% in the final CVX-343 Drug Substance

  13. Antibody-protein A conjugated quantum dots for multiplexed imaging of surface receptors in living cells.

    Science.gov (United States)

    Jin, Takashi; Tiwari, Dhermendra K; Tanaka, Shin-Ichi; Inouye, Yasushi; Yoshizawa, Keiko; Watanabe, Tomonobu M

    2010-11-01

    To use quantum dots (QDs) as fluorescent probes for receptor imaging, QD surface should be modified with biomolecules such as antibodies, peptides, carbohydrates, and small-molecule ligands for receptors. Among these QDs, antibody conjugated QDs are the most promising fluorescent probes. There are many kinds of coupling reactions that can be used for preparing antibody conjugated QDs. Most of the antibody coupling reactions, however, are non-selective and time-consuming. In this paper, we report a facile method for preparing antibody conjugated QDs for surface receptor imaging. We used ProteinA as an adaptor protein for binding of antibody to QDs. By using ProteinA conjugated QDs, various types of antibodies are easily attached to the surface of the QDs via non-covalent binding between the F(c) (fragment crystallization) region of antibody and ProteinA. To show the utility of ProteinA conjugated QDs, HER2 (anti-human epidermal growth factor receptor 2) in KPL-4 human breast cancer cells were stained by using anti-HER2 antibody conjugated ProteinA-QDs. In addition, multiplexed imaging of HER2 and CXCR4 (chemokine receptor) in the KPL-4 cells was performed. The result showed that CXCR4 receptors coexist with HER2 receptors in the membrane surface of KPL-4 cells. ProteinA mediated antibody conjugation to QDs is very useful to prepare fluorescent probes for multiplexed imaging of surface receptors in living cells.

  14. Conference report: hot topics in antibody-drug conjugate development.

    Science.gov (United States)

    Thudium, Karen; Bilic, Sanela

    2013-12-01

    American Association of Pharmaceutical Scientists National Biotechnology Conference Sheraton San Diego Hotel and Marina, San Diego, CA, USA, 19-23 May 2013 The National Biotechnology Conference, is a premier meeting for biotechnology professionals covering a broad range of hot topics in the biotechnology industry. Attracting participants from academia, industry and regulatory, this meeting features sessions that aim to address emerging subjects of interest and allows for open exchange between scientists. The 2013 conference featured leading researchers in the fields of antibody-drug conjugates (ADCs) and immunogenicity. Herein, we present a summary of the ADC hot topics, including bioanalytical and PK considerations, quantitative evaluation of the impact of immunogenicity and ADME to understand ADC drug-drug interactions, and clinical considerations for ADC development. This article aims to summarize the recommendations that were made by the speakers during various sessions throughout the conference.

  15. Current status of antibody-drug conjugate bioanalysis

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2017-04-01

    Full Text Available Antibody-drug conjugate (ADC consists of a cytotoxic drug covalently bound to a monoclonal antibody via a linker. Because of the complexity of ADC structure unique bioanalytical strategies are needed to identify, characterize and quantify the ADC species most relevant to safety and efficacy. ADC bioanalysis need an integrated bioanalytical approach including ligand-binding assay (LBA and LC-MS based assays to provide comprehensive characterization of the exposure/response relationship. This mini-review will summarize recent publications on ADC bioanalytical strategies and will focus on the publications within last three years on the advancement of hybrid ligand-binding/LC-MS methods for ADC PK and stability evaluation and for intact ADC-DAR distribution measurement to profile ADC biotransformation and catabolism. Special attention is paid to the publications on selection of ADC analytes, assay platforms and DAR characteristics of LBA as well as on the transition of the bioanalytical testing strategy at different phases of clinical development.

  16. DNA-templated antibody conjugation for targeted drug delivery to cancer cells

    DEFF Research Database (Denmark)

    Liu, Tianqiang

    2016-01-01

    conjugation strategy. Recently, a site-selective antibody conjugation method called “DNA-templated protein conjugation (DTPC)” was developed by our group. The site-selective covalently attachment of single-stranded DNA (ssDNA) to proteins was achieved by using a metal-affinity DNA probe and DNA-templated...... state to get a good pharmacological performance. Recombinant antibody engineering with non-natural amino acids, or enzyme-mediated conjugation approaches (transglutaminase, Sortase A or endoglycosidase) have been reported for producing homogeneous antibody conjugates. However, these methods require...... organic synthesis due to the wide existence of the 3-histidine cluster in most wild-type proteins. In this thesis, three projects that relate to targeted drug delivery to cancer cells based on the DTPC method is described. The first project was a delivery system which uses transferrin as the targeting...

  17. Chemical de-conjugation for investigating the stability of small molecule drugs in antibody-drug conjugates.

    Science.gov (United States)

    Chen, Tao; Su, Dian; Gruenhagen, Jason; Gu, Christine; Li, Yi; Yehl, Peter; Chetwyn, Nik P; Medley, Colin D

    2016-01-05

    Antibody-drug conjugates (ADCs) offer new therapeutic options for advanced cancer patients through precision killing with fewer side effects. The stability and efficacy of ADCs are closely related, emphasizing the urgency and importance of gaining a comprehensive understanding of ADC stability. In this work, a chemical de-conjugation approach was developed to investigate the in-situ stability of the small molecule drug while it is conjugated to the antibody. This method involves chemical-mediated release of the small molecule drug from the ADC and subsequent characterization of the released small molecule drug by HPLC. The feasibility of this technique was demonstrated utilizing a model ADC containing a disulfide linker that is sensitive to the reducing environment within cancer cells. Five reducing agents were screened for use in de-conjugation; tris(2-carboxyethyl) phosphine (TCEP) was selected for further optimization due to its high efficiency and clean impurity profile. The optimized de-conjugation assay was shown to have excellent specificity and precision. More importantly, it was shown to be stability indicating, enabling the identification and quantification of the small molecule drug and its degradation products under different formulation pHs and storage temperatures. In summary, the chemical de-conjugation strategy demonstrated here offers a powerful tool to assess the in-situ stability of small molecule drugs on ADCs and the resulting information will shed light on ADC formulation/process development and storage condition selection. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. A VAR2CSA:CSP conjugate capable of inducing dual specificity antibody responses

    DEFF Research Database (Denmark)

    Matondo, Sungwa; Thrane, Susan; Janitzek, Christoph Mikkel

    2017-01-01

    Catcher peptide. The covalent interaction between SpyTag/SpyCatcher enables the formation of DBL1x-DBL2x-ID2a:CSP conjugate vaccine. Immunogenicity and quality of antibody responses induced by the conjugate vaccine, as well as a control CSP-SpyCatcher vaccine, was tested in BALB/c mice.  Results: Serum samples...

  19. Antibody-nanoparticle conjugates to enhance the sensitivity of ELISA-based detection methods.

    Directory of Open Access Journals (Sweden)

    Margaret M Billingsley

    Full Text Available Accurate antigen detection is imperative for clinicians to diagnose disease, assess treatment success, and predict patient prognosis. The most common technique used for the detection of disease-associated biomarkers is the enzyme linked immunosorbent assay (ELISA. In an ELISA, primary antibodies are incubated with biological samples containing the biomarker of interest. Then, detectible secondary antibodies conjugated with horseradish peroxidase (HRP bind the primary antibodies. Upon addition of a color-changing substrate, the samples provide a colorimetric signal that directly correlates to the targeted biomarker concentration. While ELISAs are effective for analyzing samples with high biomarker content, they lack the sensitivity required to analyze samples with low antigen levels. We hypothesized that the sensitivity of ELISAs could be enhanced by replacing freely delivered primary antibodies with antibody-nanoparticle conjugates that provide excess binding sites for detectible secondary antibodies, ultimately leading to increased signal. Here, we investigated the use of nanoshells (NS decorated with antibodies specific to epidermal growth factor receptor (EGFR as a model system (EGFR-NS. We incubated one healthy and two breast cancer cell lines, each expressing different levels of EGFR, with EGFR-NS, untargeted NS, or unconjugated EGFR antibodies, as well as detectable secondary antibodies. We found that EGFR-NS consistently increased signal intensity relative to unconjugated EGFR antibodies, with a substantial 13-fold enhancement from cells expressing high levels of EGFR. Additionally, 40x more unconjugated antibodies were required to detect EGFR compared to those conjugated to NS. Our results demonstrate that antibody-nanoparticle conjugates lower the detection limit of traditional ELISAs and support further investigation of this strategy with other antibodies and nanoparticles. Owing to their enhanced sensitivity, we anticipate that

  20. Comparative assay of fluorescent antibody test results among twelve European National Reference Laboratories using various anti-rabies conjugates

    DEFF Research Database (Denmark)

    Robardet, E.; Andrieu, S.; Rasmussen, Thomas Bruun

    2013-01-01

    Twelve National Reference Laboratories (NRLs) for rabies have undertaken a comparative assay to assess the comparison of fluorescent antibody test (FAT) results using five coded commercial anti-rabies conjugates (Biorad, Bioveta, Fujirebio, Millipore, and SIFIN conjugates). Homogenized positive...

  1. Indocyanine green as effective antibody conjugate for intracellular molecular targeted photodynamic therapy

    Science.gov (United States)

    Wang, Sijia; Hüttmann, Gereon; Rudnitzki, Florian; Diddens-Tschoeke, Heyke; Zhang, Zhenxi; Rahmanzadeh, Ramtin

    2016-07-01

    The fluorescent dye indocyanine green (ICG) is clinically approved and has been applied for ophthalmic and intraoperative angiography, measurement of cardiac output and liver function, or as contrast agent in cancer surgery. Though ICG is known for its photochemical effects, it has played a minor role so far in photodynamic therapy or techniques for targeted protein-inactivation. Here, we investigated ICG as an antibody-conjugate for the selective inactivation of the protein Ki-67 in the nucleus of cells. Conjugates of the Ki-67 antibody TuBB-9 with different amounts of ICG were synthesized and delivered into HeLa and OVCAR-5 cells through conjugation to the nuclear localization sequence. Endosomal escape of the macromolecular antibodies into the cytoplasm was optically triggered by photochemical internalization with the photosensitizer BPD. The second light irradiation at 690 nm inactivated Ki-67 and subsequently caused cell death. Here, we show that ICG as an antibody-conjugate can be an effective photosensitizing agent. Best effects were achieved with 1.8 ICG molecules per antibody. Conjugated to antibodies, the ICG absorption peaks vary proportionally with concentration. The absorption of ICG above 650 nm within the optical window of tissue opens the possibility of selective Ki-67 inactivation deep inside of tissues.

  2. Effect of different hapten-carrier conjugation ratios and molecular orientations on antibody affinity against a peptide antigen

    DEFF Research Database (Denmark)

    Pedersen, M. K.; Sørensen, Nanna Skall; Heegaard, Peter M. H.

    2006-01-01

    ten dines at two-weeks intervals with low doses of the eight conjugates, Blood samples collected between each immunisation were analysed by ELISA for specific antibody titres and relative affinities. With both types of conjugations, the anti-peptide antibody titres increased in response to increasing...... the affinity and titre of antibodies raised against the hapten using different conjugation ratios and orientations. The peptide was coupled to ovalbumin in four Conjugation ratios and two molecular orientations - terminal and central - and the Conjugates were verified by mass spectrometry. Mice were immunised...

  3. Characterization of hapten-protein conjugates: antibody generation and immunoassay development for chlorophenoxyacetic acid pesticides.

    Science.gov (United States)

    Boro, Robin C; Singh, K Vikas; Suri, C Raman

    2009-01-01

    The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten-protein conjugates. In this study, we report a new fluorescence-based method for the characterization of hapten-protein conjugates. The method is based on an effect promoted by hapten-protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten-protein conjugation density for two different chlorophenoxyacetic acid pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxybutyric acid (2,4-DB), coupled to carrier protein. Highly sensitive anti-2,4-D and anti-2,4-DB antibodies were obtained using these well-characterized hapten-protein conjugates. The generated antibodies were used in an immunoassay format demonstrating inhibitory concentration (IC50) values equal to 30 and 7 ng/mL for 2,4-D and 2,4-DB, respectively. Linearity was observed in the concentration range between 0.1-500 nglmL with LODs around 4 and 3 ng/mL for 2,4-D and 2,4-DB, respectively, in standard water samples. The proposed method was successfully applied for the determination of the extent of hapten-protein conjugation to produce specific antibodies for immunoassay development against pesticides.

  4. Toward anticancer immunotherapeutics: well-defined polymer-antibody conjugates for selective dendritic cell targeting.

    Science.gov (United States)

    Tappertzhofen, Kristof; Bednarczyk, Monika; Koynov, Kaloian; Bros, Matthias; Grabbe, Stephan; Zentel, Rudolf

    2014-10-01

    This paper describes the synthesis of semitelechelic maleimide-modified N-(2-hydroxypropyl)methacrylamid) (HPMA) based polymers of narrow dispersity that can be conjugated e.g. to anti-DEC-205 antibodies affording "star-like" topologies (one antibody decorated with several polymer chains). FCS revealed a hydrodynamic diameter of R(h)  = 7.9 nm and SEC narrow dispersity (1.45). Primary in vitro studies with bone marrow derived dendritic cells (DC) show higher cellular binding and uptake rates compared to control samples. Moreover, incubating these conjugates to primary splenocytes demonstrates a much higher affinity to the primary DCs than to any other immune cell population within the spleen. This differentiation is, thereby, much more pronounced for the star-like conjugates than for conjugates made from polymers statistically modified with anti-DEC-205. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Study of conjugation and radiolabeling of monoclonal antibody rituximab for use in radionuclide therapy

    International Nuclear Information System (INIS)

    Massicano, Adriana Vidal Fernandes

    2011-01-01

    Lymphomas are tumors originated from the transformation of a lymphocyte in the lymphatic system. The most common lymphoma is the Non-Hodgkin Lymphoma (NHL). Advances in immunology and molecular biology have been improving NHL's detection and treatment strategies development, such as Radioimmunotherapy (RIT). Rituximab is an anti-CD20 monoclonal antibody used as immunotherapeutic to treat refractory or relapsed NHL. The goal of the present work was to conjugate this antibody to DOTA-NHS-ester bifunctional chelator and to radiolabel it with 177 Lu radioisotope in order to develop a radio immunotherapeutic agent for NHL's treatment. Different rituximab to DOTA molar ratios (1:5, 1:10, 1:20, 1:50, 1:250, 1:500 and 1:1000) were evaluated in order to determine the best condition for obtaining the highest radiochemical purity of radio immunotherapeutic. The stability of the unlabeled immuno conjugated was evaluated by high performance liquid chromatography (HPLC) for up to 240 days in different storage conditions. The stability of the labeled preparations was evaluated either after storing at 2-8 degree C or incubation in human serum at 37 degree C. The binding to serum proteins was also determined. In vivo studies were performed in healthy Swiss mice, in order to characterize the biological properties of labeled conjugate. Finally, preliminary studies of radio immuno conjugated competitive binding to CD20 positive Raji cells were carried out in order to analyze if the process of conjugation and radiolabeling compromises the immunoreactivity of the antibody. The conjugation applying lower antibody to chelator molar ratios (1:5, 1:10 and 1:20) showed high stability when stored for up to 240 days in different conditions. The HPLC analysis showed that the monoclonal antibody conjugated in molar ratio 1:50 was labeled with higher radiochemical purity (> 95%) when purified in PD-10 column. This conjugate showed reasonable stability at 2-8 degree C. The analysis of the

  6. Hacking into the granuloma: could antibody antibiotic conjugates be developed for TB?

    Science.gov (United States)

    Ekins, Sean

    2014-12-01

    Alternatives to small molecule or vaccine approaches to treating tuberculosis are rarely discussed. Attacking Mycobacterium tuberculosis in the granuloma represents a challenge. It is proposed that the conjugation of small molecules onto a monoclonal antibody that recognizes macrophage or lymphocytes cell surface receptors, might be a way to target the bacteria in the granuloma. This antibody drug conjugate approach is currently being used in 2 FDA approved targeted cancer therapies. The pros and cons of this proposal for further research are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K. (Abbott Laboratories, Department 90M, Abbott Park, IL (United States))

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates.

  8. Increased streptavidin uptake in tumors pretargeted with biotinylated antibody using a conjugate of streptavidin-Fab fragment

    International Nuclear Information System (INIS)

    Yao Zhengsheng; Zhang Meili; Sakahara, Harumi; Saga, Tsuneo; Kobayashi, Hisataka; Nakamoto, Yuji; Toyama, Sakuji; Konishi, Junji

    1998-01-01

    Radiolabeled streptavidin accumulated in tumors pretargeted with biotinylated antibody. However, the absolute delivery of radioactivity was limited. To increase the tumor uptake of radioactivity further, we conjugated streptavidin with a mouse monoclonal antibody (MAb) fragment, OST6Fab, which recognizes antigen on human osteosarcoma. Another mouse MAb, OST7, which also reacts with the same tumor but recognizes an epitope different from the OST6 epitope, was biotinylated. The radioiodinated streptavidin-OST6Fab conjugate was administered to tumor-bearing mice after the biotinylated OST7 pretargeting. The uptake of the conjugate in tumors pretargeted with the biotinylated antibody was significantly higher than that of streptavidin and that of the conjugate of streptavidin and irrelevant Fab fragment. Renal uptake of radioactivity was decreased markedly, and the blood clearance was retarded by the conjugation with Fab fragment. In conclusion, the conjugate of streptavidin with specific Fab fragment increased the accumulation of radioactivity in tumors pretargeted with biotinylated antibody

  9. Air plasma coupled with antibody-conjugated nanoparticles: a new weapon against cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, G C; Park, S R [Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Busan 602-739 (Korea, Republic of); Kim, G J; Lee, J K [Department of Electronic and Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Jeon, S M; Seo, H J [Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Iza, F, E-mail: jkl@postech.ac.k [Department of Electronic and Electrical Engineering, Loughborough University, Leicestershire LE11-3TU (United Kingdom)

    2009-02-07

    Ambient air plasmas have been known to kill cancer cells. To enhance selectivity we have used antibody-conjugated nanoparticles. We achieved five times enhancement of melanoma cell death over the case of the plasma alone by using an air plasma with gold nanoparticles bound to anti-FAK antibodies. Our results show that this new interdisciplinary technique has enormous potential for use as a complement to conventional therapies. (fast track communication)

  10. Antibody response to Haemophilus influenzae type b capsular polysaccharide conjugated to tetanus toxoid in preterm infants

    DEFF Research Database (Denmark)

    Kristensen, Kim; Gyhrs, A; Lausen, B

    1996-01-01

    OBJECTIVE: To evaluate the antibody response to a Haemophilus influenzae type b capsular polysaccharide (HibCP) tetanus toxoid (TT) conjugate vaccine (HibCP-TT) in preterm infants. SUBJECTS: Thirty-five healthy preterm infants with gestational ages (GA) from 27 to 36 weeks and birth weights from...

  11. Persistence of Serogroup C Antibody Responses Following Quadrivalent Meningococcal Conjugate Vaccination in United States Military Personnel

    Science.gov (United States)

    2014-05-14

    available at ScienceDirect Vaccine j our na l ho me page: www.elsev ier .com/ locate /vacc ine ersistence of serogroup C antibody responses following...22] Auckland C, Gray S, Borrow R, Andrews N, Goldblatt D, Ramsay M, et al. Clinical and immunologic risk factors for meningococcal C conjugate

  12. [Equilibrium and kinetic parameters of interaction between peroxidase conjugates of strophanthin and anti-peroxidase antibodies].

    Science.gov (United States)

    Tarun, E I; Karaseva, E I; Metelitsa, D I

    1997-01-01

    Interactions of three horseradish peroxidase (HRP)-strophanthin conjugates containing one, two, or three glycoside molecules (HRP-Str1, 2, or 3, respectively) with polyclonal anti-HRP antibodies were studied by homogeneous enzyme immunoassay. The total peroxidase activity of free conjugates and their immune complexes was estimated from the oxidation of o-phenylenediamine. The dissociation constants of the immune complexes and the rate constants of their dissociation and formation were determined. The equilibrium and kinetic parameters were determined for the interactions of the HRP-Str2 immune complex with anti-strophanthin and anti-HRP antibodies. The determined equilibrium and kinetic parameters of the HRP-Str interactions with anti-HRP antibodies depended on the molecular weights, sizes, and structures of the antigens studied.

  13. Therapy of Murine Pulmonary Aspergillosis with Antibody-Alliinase Conjugates and Alliin▿

    Science.gov (United States)

    Appel, Elena; Vallon-Eberhard, Alexandra; Rabinkov, Aharon; Brenner, Ori; Shin, Irina; Sasson, Keren; Shadkchan, Yona; Osherov, Nir; Jung, Steffen; Mirelman, David

    2010-01-01

    Aspergillus fumigatus is an opportunistic fungal pathogen responsible for invasive aspergillosis in immunocompromised individuals. The high morbidity and mortality rates as well as the poor efficacy of antifungal agents remain major clinical concerns. Allicin (diallyl-dithiosulfinate), which is produced by the garlic enzyme alliinase from the harmless substrate alliin, has been shown to have wide-range antifungal specificity. A monoclonal antibody (MAb) against A. fumigatus was produced and chemically ligated to the enzyme alliinase. The purified antibody-alliinase conjugate bound to conidia and hyphae of A. fumigatus at nanomolar concentrations. In the presence of alliin, the conjugate produced cytotoxic allicin molecules, which killed the fungus. In vivo testing of the therapeutical potential of the conjugate was carried out in immunosuppressed mice infected intranasally with conidia of A. fumigatus. Intratracheal (i.t.) instillation of the conjugate and alliin (four treatments) resulted in 80 to 85% animal survival (36 days), with almost complete fungal clearance. Repetitive intratracheal administration of the conjugate and alliin was also effective when treatments were initiated at a more advanced stage of infection (50 h). The fungi were killed specifically without causing damage to the lung tissue or overt discomfort to the animals. Intratracheal instillation of the conjugate without alliin or of the unconjugated monoclonal antibody significantly delayed the death of the infected mice, but only 20% of the animals survived. A limitation of this study is that the demonstration was achieved in a constrained setting. Other routes of drug delivery will be investigated for the treatment of pulmonary and extrapulmonary aspergillosis. PMID:19949059

  14. Comparison of the Photobleaching and Photostability Traits of Alexa Fluor 568- and Fluorescein Isothiocyanate- conjugated Antibody.

    Science.gov (United States)

    Mahmoudian, Jafar; Hadavi, Reza; Jeddi-Tehrani, Mahmood; Mahmoudi, Ahmad Reza; Bayat, Ali Ahmad; Shaban, Elham; Vafakhah, Mohtaram; Darzi, Maryam; Tarahomi, Majid; Ghods, Roya

    2011-01-01

    Synthetic fluorescent dyes that are conjugated to antibodies are useful tools to probe molecules. Based on dye chemical structures, their photobleaching and photostability indices are quite diverse. It is generally believed that among different fluorescent dyes, Alexa Fluor family has greater photostability than traditional dyes like fluorescein isothiocyanate (FITC) and Cy5. Alexa Fluor 568 is a member of Alexa Fluor family presumed to have superior photostability and photobleahing profiles than FITC. In this experimental study, we conjugated Alexa Fluor 568 and FITC dyes to a mouse anti-human nestin monoclonal antibody (ANM) to acquire their photobleaching profiles and photostability indices. Then, the fluorophore/antibody ratios were calculated using a spectrophotometer. The photobleaching profiles and photostability indices of conjugated antibodies were subsequently studied by immunocytochemistry (ICC). Samples were continuously illuminated and digital images acquired under a fluorescent microscope. Data were processed by ImageJ software. Alexa Fluor 568 has a brighter fluorescence and higher photostability than FITC. Alexa Fluor 568 is a capable dye to use in photostaining techniques and it has a longer photostability when compared to FITC.

  15. Compact quantum dot-antibody conjugates for FRET immunoassays with subnanomolar detection limits

    Science.gov (United States)

    Mattera, Lucia; Bhuckory, Shashi; Wegner, K. David; Qiu, Xue; Agnese, Fabio; Lincheneau, Christophe; Senden, Tim; Djurado, David; Charbonnière, Loïc J.; Hildebrandt, Niko; Reiss, Peter

    2016-05-01

    A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields ultra-compact, stable, and highly luminescent antibody-QD conjugates suitable for use in FRET immunoassays. Hydrophobic InPZnS/ZnSe/ZnS (emission wavelength: 530 nm), CdSe/ZnS (605 nm), and CdSeTe/ZnS (705 nm) QDs were surface functionalized with zwitterionic penicillamine, enabling aqueous phase transfer under conservation of the photoluminescence properties. Post-functionalization with a heterobifunctional crosslinker, containing a lipoic acid group and a maleimide function, enabled the subsequent coupling to sulfhydryl groups of proteins. This was demonstrated by QD conjugation with fragmented antibodies (F(ab)). The obtained F(ab)-QD conjugates range among the smallest antibody-functionalized nanoprobes ever reported, with a hydrodynamic diameter 26 nm without biomolecules). The LODs of 0.8 and 3.7 ng mL-1 obtained in 50 μL serum samples are below the clinical cut-off level of PSA (4 ng mL-1) and demonstrate their direct applicability in clinical diagnostics.A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields ultra-compact, stable, and highly luminescent antibody-QD conjugates suitable for use in FRET immunoassays. Hydrophobic InPZnS/ZnSe/ZnS (emission wavelength: 530 nm), CdSe/ZnS (605 nm), and CdSeTe/ZnS (705 nm) QDs were surface functionalized with zwitterionic penicillamine, enabling aqueous phase transfer under conservation of the photoluminescence properties. Post-functionalization with a heterobifunctional crosslinker, containing a lipoic acid group and a maleimide function, enabled the subsequent coupling to sulfhydryl groups of proteins. This was demonstrated by QD conjugation with fragmented antibodies (F(ab)). The obtained F(ab)-QD conjugates range among the smallest antibody-functionalized nanoprobes ever reported, with a hydrodynamic diameter 26 nm without biomolecules). The LODs

  16. [Effect of Photodynamic Inactivation (PDI) using Riboflavin-Conjugated Antibody against Staphylococcus aureus].

    Science.gov (United States)

    Song, X; Stachon, T; Seitz, B; Wang, J; Bischoff, M; Langenbucher, A; Janunts, E; Szentmáry, N

    2015-08-01

    Crosslinking/riboflavin-UVA photodynamic therapy is a potential treatment alternative in antibiotic resistant infectious keratitis. For photodynamic therapy a specific (against bacteria) conjugated antibody may be used in order to increase the effect of the treatment. In our present study we analysed the impact of photodynamic inactivation using riboflavin-conjugated antibody or riboflavin alone on Staphylococcus aureus, in vitro. Staphylococcus aureus (S. aureus) was incubated in 1 : 100 diluted riboflavin-conjugated antibody (R-AB) for 30 minutes in darkness. Following UVA-light illumination (375 nm) with an energy dose of 2, 3, 4 and 8 J/cm(2), bacteria were brought to blood agar Plates for 24 hours before colony-forming unit (CFU) counting. In an additional group, we incubated bacteria to 0, 0.05 or 0.1 % riboflavin 5-phosphate as described above followed by illumination using UVA light (375 nm) with an energy dose of 2 J/cm(2), before CFU counting. The number of CFU decreased significantly (inactivation of 36 %, p = 0.022) using 1 : 100 diluted riboflavin-conjugated antibody and 2 J/cm(2) UVA-light illumination, compared to untreated controls. The use of 3, 4 und 8 J/cm(2) energy dose and R-AB in 1 : 100 dilution did not further change the decrease of CFU (inactivation of 39, 39 and 40 %; p = 0.016; p = 0.016; p = 0.015). The use of 0.05 % or 0.1 % riboflavin 5-phosphate alone and UVA-light illumination reduced the CFU count significantly (inactivation of 73 and 55 %; p = 0.002; p = 0.005), compared to untreated controls. The use of riboflavin-conjugated antibody or 0.05 % or 0.1 % riboflavin 5-phosphate and UVA-light illumination reduces the number of CFU of S. aureus. However, none of these photodynamic therapies reached the necessary 99 % killing rate of these bacteria. Further work is needed to increase the efficacy of riboflavin-conjugated antibodies against antibiotic resistant bacteria. Georg

  17. Opsonic and protective properties of antibodies raised to conjugate vaccines targeting six Staphylococcus aureus antigens.

    Directory of Open Access Journals (Sweden)

    Clarissa Pozzi

    Full Text Available Staphylococcus aureus is a major cause of nosocomial and community-acquired infections for which a vaccine is greatly desired. Antigens found on the S. aureus outer surface include the capsular polysaccharides (CP of serotype 5 (CP5 or 8 (CP8 and/or a second antigen, a β-(1→6-polymer of N-acetyl-D-glucosamine (PNAG. Antibodies specific for either CP or PNAG antigens have excellent in vitro opsonic killing activity (OPKA, but when mixed together have potent interference in OPKA and murine protection. To ascertain if this interference could be abrogated by using a synthetic non-acetylated oligosaccharide fragment of PNAG, 9GlcNH(2, in place of chemically partially deacetylated PNAG, three conjugate vaccines consisting of 9GlcNH(2 conjugated to a non-toxic mutant of alpha-hemolysin (Hla H35L, CP5 conjugated to clumping factor B (ClfB, or CP8 conjugated to iron-surface determinant B (IsdB were used separately to immunize rabbits. Opsonic antibodies mediating killing of multiple S. aureus strains were elicited for all three vaccines and showed carbohydrate antigen-specific reductions in the tissue bacterial burdens in animal models of S. aureus skin abscesses, pneumonia, and nasal colonization. Carrier-protein specific immunity was also shown to be effective in reducing bacterial levels in infected lungs and in nasal colonization. However, use of synthetic 9GlcNH(2 to induce antibody to PNAG did not overcome the interference in OPKA engendered when these were combined with antibody to either CP5 or CP8. Whereas each individual vaccine showed efficacy, combining antisera to CP antigens and PNAG still abrogated individual OPKA activities, indicating difficulty in achieving a multi-valent vaccine targeting both the CP and PNAG antigens.

  18. Novel Phospholipid-Protein Conjugates Allow Improved Detection of Antibodies in Patients with Autoimmune Diseases

    DEFF Research Database (Denmark)

    Samuelsen, Simone V; Maity, Arindam; Nybo, Mads

    2016-01-01

    Reliable measurement of clinically relevant autoimmune antibodies toward phospholipid-protein conjugates is highly desirable in research and clinical assays. To date, the development in this field has been limited to the use of natural heterogeneous antigens. However, this approach does not take ...... on the correlation of detected autoantibodies with disease activity and manifestations. This confirms the crucial importance of antigens' composition on research and diagnostic assays, and opens up exciting perspectives for synthetic antigens in future studies of autoimmunity.......Reliable measurement of clinically relevant autoimmune antibodies toward phospholipid-protein conjugates is highly desirable in research and clinical assays. To date, the development in this field has been limited to the use of natural heterogeneous antigens. However, this approach does not take...... structural features of biologically active antigens into account and leads to low reliability and poor scientific test value. Here we describe novel phospholipid-protein conjugates for specific detection of human autoimmune antibodies. Our synthetic approach includes mild oxidation of synthetic phospholipid...

  19. Synthesis and antibody conjugation of magnetic nanoparticles with improved specific power absorption rates for alternating magnetic field cancer therapy

    International Nuclear Information System (INIS)

    Gruettner, Cordula; Mueller, Knut; Teller, Joachim; Westphal, Fritz; Foreman, Allan; Ivkov, Robert

    2007-01-01

    Bionized nanoferrite (BNF) particles with high specific power absorption rates were synthesized in the size range of 20-100 nm by high-pressure homogenization for targeted cancer therapy with alternating magnetic fields. Several strategies were used to conjugate antibodies to the BNF particles. These strategies were compared using an immunoassay to find optimal conditions to reach a high immunoreactivity of the final antibody-particle conjugate

  20. Antibody-Drug Conjugates (ADCs) for Personalized Treatment of Solid Tumors: A Review.

    Science.gov (United States)

    Lambert, John M; Morris, Charles Q

    2017-05-01

    Attaching a cytotoxic "payload" to an antibody to form an antibody-drug conjugate (ADC) provides a mechanism for selective delivery of the cytotoxic agent to cancer cells via the specific binding of the antibody to cancer-selective cell surface molecules. The first ADC to receive marketing authorization was gemtuzumab ozogamicin, which comprises an anti-CD33 antibody conjugated to a highly potent DNA-targeting antibiotic, calicheamicin, approved in 2000 for treating acute myeloid leukemia. It was withdrawn from the US market in 2010 following an unsuccessful confirmatory trial. The development of two classes of highly potent microtubule-disrupting agents, maytansinoids and auristatins, as payloads for ADCs resulted in approval of brentuximab vedotin in 2011 for treating Hodgkin lymphoma and anaplastic large cell lymphoma, and approval of ado-trastuzumab emtansine in 2013 for treating HER2-positive breast cancer. Their success stimulated much research into the ADC approach, with >60 ADCs currently in clinical evaluation, mostly targeting solid tumors. Five ADCs have advanced into pivotal clinical trials for treating various solid tumors-platinum-resistant ovarian cancer, mesothelioma, triple-negative breast cancer, glioblastoma, and small cell lung cancer. The level of target expression is a key parameter in predicting the likelihood of patient benefit for all these ADCs, as well as for the approved compound, ado-trastuzumab emtansine. The development of a patient selection strategy linked to target expression on the tumor is thus critically important for identifying the population appropriate for receiving treatment.

  1. Properties of surface functionalized iron oxide nanoparticles (ferrofluid) conjugated antibody for lateral flow immunoassay application

    Energy Technology Data Exchange (ETDEWEB)

    Nor, Noorhashimah Mohamad [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Abdul Razak, Khairunisak, E-mail: khairunisak@eng.usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); NanoBiotechnology Research and Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), 11800 USM, Penang (Malaysia); Tan, Soo Choon; Noordin, Rahmah [NanoBiotechnology Research and Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), 11800 USM, Penang (Malaysia)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer The effects of acid functionalization and biocompatible polymer on iron oxide nanoparticles (IONPs) ferrofluid were studied. Black-Right-Pointing-Pointer The IONPs functionalized using citric acid (IONPs-CA) is the most stable ferrofluid with zeta potential value of -49 mV. Black-Right-Pointing-Pointer IONPs-CA can be directly conjugated with antibody without biocompatible polymer coating. Black-Right-Pointing-Pointer IONPs-CA had optimum detection efficiency of 15 min assay time. Black-Right-Pointing-Pointer IONPs-CA showed the highest colour intensity in labelling lateral flow immunoassay. - Abstract: In this study, colloidal stability of iron oxide nanoparticles (IONPs) with several acid functionalizations and biocompatible polymer coating were compared for use as labelling agent in lateral flow immunoassay (LFIA). IONPs were synthesized using the precipitation method and peptized using perchloric acid (PA), nitric acid (NA) and citric acid (CA) to form a stable IONPs ferrofluid. Steric stabilization of IONPs using silane polyethelene glycol (SiPEG) was developed to improve biocompatibility and provide spaces for subsequent conjugation process. From the transmission electron microscopy (TEM) images, the sizes of IONPs obtained with different acids peptization were in range of 11-17 nm. The IONPs peptized using citric acid showed the most stable ferrofluid condition at physiological condition with zeta potential value of -49 mV. The LFIA was also developed to examine the conjugation properties of IONPs to mouse anti-human IgG{sub 4} antibody (M{alpha}HIgG{sub 4}). IONPs functionalized with citric acid can be directly conjugated with the M{alpha}HIgG{sub 4} without the need of SiPEG addition. This is due to the presence of the carboxylic group that acted as a ligand to the extended bond formation with the antibody. Moreover, the conjugation of IONPs with M{alpha}HIgG{sub 4} was also tested in a LFIA to detect brugian

  2. Multiplexed detection of various breast cancer cells by perfluorocarbon/quantum dot nanoemulsions conjugated with antibodies

    Science.gov (United States)

    Bae, Pan Kee; Chung, Bong Hyun

    2014-07-01

    The effective targeting of cancer cell surface antigens is an attractive approach in cancer diagnosis and therapy. Multifunctional nanoprobes with cell-targeting specificity are likely to find important applications in bioanalysis, biomedicine, and clinical diagnosis. In this study, we have fabricated biocompatible perfluorocan/quantum dot nanoemulsions as bimodal imaging nanoprobes for the targeting of breast cancer cells. Perfluorocarbon/quantum dot nanoemulsions conjugated with monoclonal antibodies, as a type of bimodal imaging nanoprobe based on 19 F-MR and optical imaging, have been synthesized and applied for targeted imaging of three different breast cancer cells (SKBR3, MCF-7, MDA-MB 468), respectively. We have shown that the cancer-detection capabilities of antibody-conjugated PFC/QDs nanoemulsions could be successfully applied to target of various breast cancer cells. These modified PFC/QDs nanoemulsions were shown to target the cancer cell surface receptors specially. Conjugation of ligands to nanoemulsions targeting over-expressed cell surface receptors is a promising approach for targeted imaging to tumor cells. We further propose that the PFC/QDs nanoemulsions could be used in targeted imaging of breast cancer cells.

  3. Quantification and imaging of HER2 protein using nanocrystals conjugated with single-domain antibodies

    International Nuclear Information System (INIS)

    Glukhov, S; Berestovoy, M; Nabiev, I; Sukhanova, A; Chames, P; Baty, D

    2017-01-01

    This study dealt with quantification and imaging of human epidermal growth factor receptor 2 (HER2), an important prognostic marker for cancer diagnosis and treatment, using specific quantum-dot-based conjugates. Fluorescent inorganic nanocrystals or quantum dots (QDs) are extremely highly resistant to photobleaching and have a high emission quantum yield and a continuous range of emission spectra, from the ultraviolet to the infrared regions. Ultrasmall nanoprobes consisting of highly affine anti-HER2 single-domain antibodies (sdAbs or 'nanobodies') conjugated with QDs in a strictly oriented manner have been designed. QDs with a fluorescence peak maxima at wavelengths of 562 nm, 569 nm, 570 nm or in the near-infrared region were used. Here, we present our results of ISA quantification of HER2 protein, in situ imaging of HER2 protein on the surface of HER2-positive SK-BR-3 cells in immunohistochemical experiments, and counting of stained with anti-HER2 conjugates HER2-positive SK-BR-3 cells in their mixture with unstained cells of the same culture in flow cytometry experiments. The data demonstrate that the anti-HER2 QD–sdAb conjugates obtained are highly specific and sensitive and could be used in numerous applications for advanced integrated diagnosis. (paper)

  4. Synthesis and evaluation of 99mTc/99Tc-MAG3-biotin conjugates for antibody pretargeting strategies

    International Nuclear Information System (INIS)

    Gog, Frank B. van; Visser, Gerard W.M.; Gowrising, Radjish W.A.; Snow, Gordon B.; Dongen, Guus A.M.S. van

    1998-01-01

    Four 99m Tc-MAG3-biotin conjugates were synthesized to determine their potential use in antibody pretargeting strategies for radioimmunoscintigraphy (RIS). To use these 99m Tc-MAG3-biotin conjugates as model compounds for 186 Re-MAG3-biotin conjugates for radioimmunotherapy (RIT), nanomolar amounts of 99 Tc were added as carrier to 99m Tc. The biotin derivatives used for the preparation of the conjugates - biocytin, biotin hydrazide, biotinyl-piperazine, and biotinyl-diaminosuccinic acid - differed at the site that is regarded to be susceptible to hydrolysis by biotinidase present in human plasma. All four conjugates were produced with high radiochemical purity, were stable in PBS, and demonstrated full binding capacity to streptavidin. The 99m Tc/ 99 Tc-MAG3-labeled biotinyl-piperazine and biotinyl-diaminosuccinic acid conjugates were stable in mouse as well as human plasma, whereas the corresponding biocytin and biotin hydrazide conjugates were rapidly degraded. The biodistribution in nude mice at 30 min after injection was similar for all conjugates, and a rapid blood clearance and high intestinal excretion were both observed. It is concluded that the metabolic routing of a conjugate containing biotin and MAG3 is dominated by these two moieties. For this reason, MAG3-biotin conjugates do not seem suited for pretargeted RIT, for which quantitative and fast renal excretion is a prerequisite to minimize radiation toxicity. However, in a pretargeted RIS approach the 99m Tc-MAG3-biotin conjugates might have potential

  5. Novel Phospholipid-Protein Conjugates Allow Improved Detection of Antibodies in Patients with Autoimmune Diseases.

    Science.gov (United States)

    Samuelsen, Simone V; Maity, Arindam; Nybo, Mads; Macaubas, Claudia; Lønstrup, Lars; Balboni, Imelda M; Mellins, Elizabeth D; Astakhova, Kira

    2016-01-01

    Reliable measurement of clinically relevant autoimmune antibodies toward phospholipid-protein conjugates is highly desirable in research and clinical assays. To date, the development in this field has been limited to the use of natural heterogeneous antigens. However, this approach does not take structural features of biologically active antigens into account and leads to low reliability and poor scientific test value. Here we describe novel phospholipid-protein conjugates for specific detection of human autoimmune antibodies. Our synthetic approach includes mild oxidation of synthetic phospholipid cardiolipin, and as the last step, coupling of the product with azide-containing linker and copper-catalyzed click chemistry with β2-glycoprotein I and prothrombin. To prove utility of the product antigens, we used enzyme-linked immunosorbent assay and three cohorts of samples obtained from patients in Denmark (n = 34) and the USA (n = 27 and n = 14). Afterwards we analyzed correlation of the obtained autoantibody titers with clinical parameters for each patient. Our results prove that using novel antigens clinically relevant autoantibodies can be detected with high repeatability, sensitivity and specificity. Unlike previously used antigens the obtained autoantibody titers strongly correlate with high disease activity and in particular, with arthritis, renal involvement, anti-Smith antibodies and high lymphocyte count. Importantly, chemical composition of antigens has a strong influence on the correlation of detected autoantibodies with disease activity and manifestations. This confirms the crucial importance of antigens' composition on research and diagnostic assays, and opens up exciting perspectives for synthetic antigens in future studies of autoimmunity.

  6. Evaluation of methods for large scale preparation of antibody ligand conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Wu Chuanchu; Gansow, Otto A.; Brechbiel, Martin W. E-mail: martinwb@box-m.nih.gov

    1999-04-01

    A rapid, single vessel method for preparation of clinical grade monoclonal antibody-chelating agent conjugates has been evaluated. By use of diafiltration methodology, currently employed dialysis step(s) that are normally used for the production of immunoconjugates may be eliminated. This technique has the advantage of eliminating the use of large amounts of buffer and the several days of time associated with purification of the product conjugate from unreacted ligand by dialysis, reduced risk of metal, pyrogen, and bacterial contamination, all coupled with the ability to produce multi-hundred milligram amounts of product suitable for vialing under GMP conditions for clinical applications. Evaluation of the product by this method indicates a superior quality of purity as compared with immunoconjugates prepared by the established methods.

  7. Kinetics of antibody responses after primary immunization with meningococcal serogroup C conjugate vaccine or secondary immunization with either conjugate or polysaccharide vaccine in adults

    NARCIS (Netherlands)

    de Voer, Richarda M.; van der Klis, Fiona R. M.; Engels, Carla W. A. M.; Schepp, Rutger M.; van de Kassteele, Jan; Sanders, Elisabeth A. M.; Rijkers, Ger T.; Berbers, Guy A. M.

    2009-01-01

    In the Netherlands the meningococcal serogroup C conjugate (MenCC) vaccine is administered as a single dose at 14 months. We evaluated the kinetics of isotype-specific antibodies in adults (n = 21) after primary immunization with MenCC or secondary immunization with MenCC or plain MenC

  8. Development and Characterization of a Camelid Single Domain Antibody-Urease Conjugate That Targets Vascular Endothelial Growth Factor Receptor 2.

    Science.gov (United States)

    Tian, Baomin; Wong, Wah Yau; Uger, Marni D; Wisniewski, Pawel; Chao, Heman

    2017-01-01

    Angiogenesis is the process of new blood vessel formation and is essential for a tumor to grow beyond a certain size. Tumors secrete the pro-angiogenic factor vascular endothelial growth factor, which acts upon local endothelial cells by binding to vascular endothelial growth factor receptors (VEGFRs). In this study, we describe the development and characterization of V21-DOS47, an immunoconjugate that targets VEGFR2. V21-DOS47 is composed of a camelid single domain anti-VEGFR2 antibody (V21) and the enzyme urease. The conjugate specifically binds to VEGFR2 and urease converts endogenous urea into ammonia, which is toxic to tumor cells. Previously, we developed a similar antibody-urease conjugate, L-DOS47, which is currently in clinical trials for non-small cell lung cancer. Although V21-DOS47 was designed from parameters learned from the generation of L-DOS47, additional optimization was required to produce V21-DOS47. In this study, we describe the expression and purification of two versions of the V21 antibody: V21H1 and V21H4. Each was conjugated to urease using a different chemical cross-linker. The conjugates were characterized by a panel of analytical techniques, including SDS-PAGE, size exclusion chromatography, Western blotting, and LC-MS E peptide mapping. Binding characteristics were determined by ELISA and flow cytometry assays. To improve the stability of the conjugates at physiologic pH, the pIs of the V21 antibodies were adjusted by adding several amino acid residues to the C-terminus. For V21H4, a terminal cysteine was also added for use in the conjugation chemistry. The modified V21 antibodies were expressed in the E. coli BL21 (DE3) pT7 system. V21H1 was conjugated to urease using the heterobifunctional cross-linker succinimidyl-[( N -maleimidopropionamido)-diethyleneglycol] ester (SM(PEG) 2 ), which targets lysine resides in the antibody. V21H4 was conjugated to urease using the homobifunctional cross-linker, 1,8-bis(maleimido)diethylene glycol

  9. Synthetic rabbit-human antibody conjugate as a control in immunoassays for immunoglobulin M specific to hepatitis E virus

    Directory of Open Access Journals (Sweden)

    Zhang Rui

    2010-05-01

    Full Text Available Abstract Background In assays for anti-hepatitis E virus (HEV immunoglobulin M (IgM, large volumes of the patient's sera cannot be easily obtained for use as a positive control. In this study, we investigated an alternative chemical method in which rabbit anti-HEV IgG was conjugated with human IgM and was used as a positive control in the anti-HEV IgM assay. Rabbit anti-HEV IgG was isolated from immune sera by chromatography on protein A-Sepharose and was conjugated with human IgM by using 1-ethyl-3-(3-dimethylaminopropylcarbodiimide (EDC as a crosslinker. Results The specific anti-HEV IgG antibody titer was 100,000 times that of the negative control, i.e., prebleed rabbit serum. The results of anti-HEV IgM enzyme-linked immunosobent assay showed that the antibody conjugate was similar to anti-HEV IgM antibodies produced in humans. The results of a stability experiment showed that the antibody conjugate was stable for use in external quality assessment or internal quality control trials. Conclusions We concluded that the chemically conjugated rabbit-human antibody could be used instead of the traditional serum control as a positive control in the anti-HEV IgM assay.

  10. The preparation and characterization of the metal-texaphyrin complex and metal-texaphyrin-antibody conjugate

    International Nuclear Information System (INIS)

    Rekova, M.; Kral, V.; Jedinakova-Krizova, V.

    2006-01-01

    This work was aimed to the preparation of yttrium-texaphyrin or lutetium-texaphyrin complex and the characterization of these complexes by various methods. The yttrium-texaphyrin complex (or the lutetium-texaphyrin complex) was prepared via transmetallation of the calcium-texaphyrin complex in ethanol at 70 deg C. The complexes prepared were purified on reverse-phase SepPak TM columns (C18). Mass spectrometry (MS-ESI) and UV-VIS spectrophotometry were used for analytical determination of the yttrium-texaphyrin complex and lutetium-texaphyrin complex in the transmetallation product. The complexes were characterized by UV-VIS spectrophotometry, IRFT spectroscopy, FT-Raman spectroscopy, etc. The complexes were also labelled with radionuclides such as 90 Y and 177 Lu. These complexes are conjugated with the monoclonal antibody and labelled with 90 Y or 177 Lu nuclides. After clinical testing, the radionuclide-texaphyrin-monoclonal antibody immunoconjugates can be used for diagnosis and therapy. (author)

  11. Radioimmunotherapy: a specific treatment protocol for cancer by cytotoxic radioisotopes conjugated to antibodies.

    Science.gov (United States)

    Kawashima, Hidekazu

    2014-01-01

    Radioimmunotherapy (RIT) represents a selective internal radiation therapy, that is, the use of radionuclides conjugated to tumor-directed monoclonal antibodies (including those fragments) or peptides. In a clinical field, two successful examples of this treatment protocol are currently extended by (90)Y-ibritumomab tiuxetan (Zevalin) and (131)I-tositumomab (Bexxar), both of which are anti-CD20 monoclonal antibodies coupled to cytotoxic radioisotopes and are approved for the treatment of non-Hodgkin lymphoma patients. In addition, some beneficial observations are obtained in preclinical studies targeting solid tumors. To date, in order to reduce the unnecessary exposure and to enhance the therapeutic efficacy, various biological, chemical, and treatment procedural improvements have been investigated in RIT. This review outlines the fundamentals of RIT and current knowledge of the preclinical/clinical trials for cancer treatment.

  12. Radioimmunotherapy: A Specific Treatment Protocol for Cancer by Cytotoxic Radioisotopes Conjugated to Antibodies

    Directory of Open Access Journals (Sweden)

    Hidekazu Kawashima

    2014-01-01

    Full Text Available Radioimmunotherapy (RIT represents a selective internal radiation therapy, that is, the use of radionuclides conjugated to tumor-directed monoclonal antibodies (including those fragments or peptides. In a clinical field, two successful examples of this treatment protocol are currently extended by 90Y-ibritumomab tiuxetan (Zevalin and 131I-tositumomab (Bexxar, both of which are anti-CD20 monoclonal antibodies coupled to cytotoxic radioisotopes and are approved for the treatment of non-Hodgkin lymphoma patients. In addition, some beneficial observations are obtained in preclinical studies targeting solid tumors. To date, in order to reduce the unnecessary exposure and to enhance the therapeutic efficacy, various biological, chemical, and treatment procedural improvements have been investigated in RIT. This review outlines the fundamentals of RIT and current knowledge of the preclinical/clinical trials for cancer treatment.

  13. Drug-to-antibody determination for an antibody-drug-conjugate utilizing cathepsin B digestion coupled with reversed-phase high-pressure liquid chromatography analysis.

    Science.gov (United States)

    Adamo, Michael; Sun, Guoyong; Qiu, Difei; Valente, Joseph; Lan, Wenkui; Song, Hangtian; Bolgar, Mark; Katiyar, Amit; Krishnamurthy, Girija

    2017-01-20

    Antibody drug conjugates or ADCs are currently being evaluated for their effectiveness as targeted chemotherapeutic agents across the pharmaceutical industry. Due to the complexity arising from the choice of antibody, drug and linker; analytical methods for release and stability testing are required to provide a detailed understanding of both the antibody and the drug during manufacturing and storage. The ADC analyzed in this work consists of a tubulysin drug analogue that is randomly conjugated to lysine residues in a human IgG1 antibody. The drug is attached to the lysine residue through a peptidic, hydrolytically stable, cathepsin B cleavable linker. The random lysine conjugation produces a heterogeneous mixture of conjugated species with a variable drug-to-antibody ratio (DAR), therefore, the average amount of drug attached to the antibody is a critical parameter that needs to be monitored. In this work we have developed a universal method for determining DAR in ADCs that employ a cathepsin B cleavable linker. The ADC is first cleaved at the hinge region and then mildly reduced prior to treatment with the cathepsin B enzyme to release the drug from the antibody fragments. This pre-treatment allows the cathepsin B enzyme unrestricted access to the cleavage sites and ensures optimal conditions for the cathepsin B to cleave all the drug from the ADC molecule. The cleaved drug is then separated from the protein components by reversed phase high performance liquid chromatography (RP-HPLC) and quantitated using UV absorbance. This method affords superior cleavage efficiency to other methods that only employ a cathepsin digestion step as confirmed by mass spectrometry analysis. This method was shown to be accurate and precise for the quantitation of the DAR for two different random lysine conjugated ADC molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Development of a peptide conjugate vaccine for inducing therapeutic anti-IgE antibodies.

    Science.gov (United States)

    Licari, Amelia; Castagnoli, Riccardo; De Sando, Elisabetta; Marseglia, Gian Luigi

    2017-04-01

    Given the multifaceted effector functions of IgE in immediate hypersensitivity, late-phase reactions, regulation of IgE receptor expression and immune modulation, IgE antibodies have long represented an attractive target for therapeutic agents in asthma and other allergic diseases. Effective pharmacologic blockade of the binding of IgE to its receptors has become one of most innovative therapeutic strategies in the field of allergic diseases in the last 10 years. Areas covered: The latest strategies targeting IgE include the development of a therapeutic vaccine, able to trigger our own immune systems to produce therapeutic anti-IgE antibodies, potentially providing a further step forward in the treatment of allergic diseases. The aim of this review is to discuss the discovery strategy, preclinical and early clinical development of a peptide conjugate vaccine for inducing therapeutic anti-IgE antibodies. Expert opinion: Outside the area of development of humanized anti-IgE monoclonal antibodies, the research field of therapeutic IgE-targeted vaccines holds potential benefits for the treatment of allergic diseases. However, most of the experimental observations in animal models have not yet been translated into new treatments and evidence of human efficacy and safety of this new therapeutic strategy are still lacking.

  15. Assembly of High-Potency Photosensitizer-Antibody Conjugates through Application of Dendron Multiplier Technology.

    Science.gov (United States)

    Bryden, Francesca; Maruani, Antoine; Rodrigues, João M M; Cheng, Miffy H Y; Savoie, Huguette; Beeby, Andrew; Chudasama, Vijay; Boyle, Ross W

    2018-01-17

    Exploitation of photosensitizers as payloads for antibody-based anticancer therapeutics offers a novel alternative to the small pool of commonly utilized cytotoxins. However, existing bioconjugation methodologies are incompatible with the requirement of increased antibody loading without compromising antibody function, stability, or homogeneity. Herein, we describe the first application of dendritic multiplier groups to allow the loading of more than 4 porphyrins to a full IgG antibody in a site-specific and highly homogeneous manner. Photophysical evaluation of UV-visible absorbance and singlet oxygen quantum yields highlighted porphyrin-dendron 14 as the best candidate for bioconjugation; with subsequent bioconjugation producing a HER2-targeted therapeutic with average loading ratios of 15.4:1. In vitro evaluation of conjugate 18 demonstrated a nanomolar photocytotoxic effect in a target cell line, which overexpresses HER2, with no observed photocytotoxicity at the same concentration in a control cell line which expresses native HER2 levels, or in the absence of irradiation with visible light.

  16. The study of conjugation of anti-CD20 monoclonal antibody for labeling with metallic or lanthanides radionuclides

    International Nuclear Information System (INIS)

    Akanji, Akinkunmi Ganiyu

    2012-01-01

    Lymphomas are malignancies or cancers that start from the malign transformation of a lymphocyte in the lymphatic system. Generally, lymphomas start from the lymph nodes or from the agglomeration of the lymphatic tissues, organs like stomach, intestines, in some cases it can involve the bone marrow and the blood, it can also disseminate to other organs. Lymphomas are divided in two major categories: Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Patient with NHL are generally treated with radiotherapy alone or combined with immunotherapy using monoclonal antibody rituximab (MabThera®). Currently, monoclonal antibodies (Acm) conjugated with bifunctional chelate agents and radiolabeled with metallic or lanthanides radionuclides are a treatment reality for patients with NHL by the principle of radioimmunotherapy (RIT). This study focused on the conditions of conjugation of Acm rituximab (MabThera®) with bifunctional chelating agents DOTA and DTPA. Various parameters were studied: method of Acm purification, conditions of Acm conjugation, the method for determination of number of chelate agent coupled to the Acm, method for purification of the conjugated antibody Acm, conditions of labeling of the conjugated antibody with lutetium-177, method of purification of the radiolabeled immuno conjugate, method of radiochemical purity (RP), specific binding in vitro Raji cells (Human Burkitt) and biological distribution performed in normal Balb-c mouse. The three methodologies employed in pre-purification of Acm (dialysis, size exclusion chromatograph and dial filtration) demonstrated to be efficient; they provided sample recovery exceeding 90%. However, the methodology of dial filtration presents minimal sample loss, and gave the final recovery of the sample in micro liters; thereby facilitating sample use in subsequent experiments. Numbers of chelators attached to the Acm molecule was proportional to the molar ratio studied. When we evaluated the influence of different

  17. Lipophilic indocarbocyanine conjugates for efficient incorporation of enzymes, antibodies and small molecules into biological membranes.

    Science.gov (United States)

    Smith, Weston J; Tran, Huy; Griffin, James I; Jones, Jessica; Vu, Vivian P; Nilewski, Lizanne; Gianneschi, Nathan; Simberg, Dmitri

    2018-04-01

    Decoration of cell membranes with biomolecules, targeting ligands and imaging agents is an emerging strategy to improve functionality of cell-based therapies. Compared to covalent chemistry or genetic expression on the cell surface, lipid painting (i.e., incorporation of lipid-conjugated molecules into the cell bilayer) is a fast, non-damaging and less expensive approach. Previous studies demonstrated excellent incorporation and retention of distearyl indocarbocyanine dye DiI in membranes of cells in vitro and in vivo. In order to exploit the membrane stability of DiI, we synthesized an amino-DiI derivative, to which we subsequently conjugated an antibody (cetuximab), an enzyme (superoxide dismutase), and a small molecule (DyLight 800). Red blood cells have long been used as drug delivery vehicles so they were utilized as a model to study the incorporation of DiI conjugates in the plasma membrane. All the DiI constructs demonstrated fast and efficient ex vivo incorporation in the membrane of mouse RBCs, resulting in millions of exogenous molecules per RBC. Following an intravenous injection into mice, the molecules were detected on circulating RBCs for several days. DiI anchored molecules showed longer residence time in blood and significantly higher area under the curve (AUC) compared to free non-conjugated molecules. Thus, cetuximab, SOD and DyLight painted on RBC showed 5.5-fold, 6.5-fold and 78-fold increase in the AUC, respectively, compared to the non-modified molecules. Lipophilic indocarbocyanine anchors are a promising technology for incorporation of biomolecules and small molecules into biological membranes for in vivo applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Novel Phospholipid-Protein Conjugates Allow Improved Detection of Antibodies in Patients with Autoimmune Diseases.

    Directory of Open Access Journals (Sweden)

    Simone V Samuelsen

    Full Text Available Reliable measurement of clinically relevant autoimmune antibodies toward phospholipid-protein conjugates is highly desirable in research and clinical assays. To date, the development in this field has been limited to the use of natural heterogeneous antigens. However, this approach does not take structural features of biologically active antigens into account and leads to low reliability and poor scientific test value. Here we describe novel phospholipid-protein conjugates for specific detection of human autoimmune antibodies. Our synthetic approach includes mild oxidation of synthetic phospholipid cardiolipin, and as the last step, coupling of the product with azide-containing linker and copper-catalyzed click chemistry with β2-glycoprotein I and prothrombin. To prove utility of the product antigens, we used enzyme-linked immunosorbent assay and three cohorts of samples obtained from patients in Denmark (n = 34 and the USA (n = 27 and n = 14. Afterwards we analyzed correlation of the obtained autoantibody titers with clinical parameters for each patient. Our results prove that using novel antigens clinically relevant autoantibodies can be detected with high repeatability, sensitivity and specificity. Unlike previously used antigens the obtained autoantibody titers strongly correlate with high disease activity and in particular, with arthritis, renal involvement, anti-Smith antibodies and high lymphocyte count. Importantly, chemical composition of antigens has a strong influence on the correlation of detected autoantibodies with disease activity and manifestations. This confirms the crucial importance of antigens' composition on research and diagnostic assays, and opens up exciting perspectives for synthetic antigens in future studies of autoimmunity.

  19. Target-mediated drug disposition model and its approximations for antibody-drug conjugates.

    Science.gov (United States)

    Gibiansky, Leonid; Gibiansky, Ekaterina

    2014-02-01

    Antibody-drug conjugate (ADC) is a complex structure composed of an antibody linked to several molecules of a biologically active cytotoxic drug. The number of ADC compounds in clinical development now exceeds 30, with two of them already on the market. However, there is no rigorous mechanistic model that describes pharmacokinetic (PK) properties of these compounds. PK modeling of ADCs is even more complicated than that of other biologics as the model should describe distribution, binding, and elimination of antibodies with different toxin load, and also the deconjugation process and PK of the released toxin. This work extends the target-mediated drug disposition (TMDD) model to describe ADCs, derives the rapid binding (quasi-equilibrium), quasi-steady-state, and Michaelis-Menten approximations of the TMDD model as applied to ADCs, derives the TMDD model and its approximations for ADCs with load-independent properties, and discusses further simplifications of the system under various assumptions. The developed models are shown to describe data simulated from the available clinical population PK models of trastuzumab emtansine (T-DM1), one of the two currently approved ADCs. Identifiability of model parameters is also discussed and illustrated on the simulated T-DM1 examples.

  20. Carrier priming or suppression: understanding carrier priming enhancement of anti-polysaccharide antibody response to conjugate vaccines.

    Science.gov (United States)

    Pobre, Karl; Tashani, Mohamed; Ridda, Iman; Rashid, Harunor; Wong, Melanie; Booy, Robert

    2014-03-14

    With the availability of newer conjugate vaccines, immunization schedules have become increasingly complex due to the potential for unpredictable immunologic interference such as 'carrier priming' and 'carrier induced epitopic suppression'. Carrier priming refers to an augmented antibody response to a carbohydrate portion of a glycoconjugate vaccine in an individual previously primed with the carrier protein. This review aims to provide a critical evaluation of the available data on carrier priming (and suppression) and conceptualize ways by which this phenomenon can be utilized to strengthen vaccination schedules. We conducted this literature review by searching well-known databases to date to identify relevant studies, then extracted and synthesized the data on carrier priming of widely used conjugate polysaccharide vaccines, such as, pneumococcal conjugate vaccine (PCV), meningococcal conjugate vaccine (MenCV) and Haemophilus influenzae type b conjugate vaccines (HibV). We found evidence of carrier priming with some conjugate vaccines, particularly HibV and PCV, in both animal and human models but controversy surrounds MenCV. This has implications for the immunogenicity of conjugate polysaccharide vaccines following the administration of tetanus-toxoid or diphtheria-toxoid containing vaccine (such as DTP). Available evidence supports a promising role for carrier priming in terms of maximizing the immunogenicity of conjugate vaccines and enhancing immunization schedule by making it more efficient and cost effective. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Conjugation of ampicillin and enrofloxacin residues with bovine serum albumin and raising of polyclonal antibodies against them

    Directory of Open Access Journals (Sweden)

    B. Sampath Kumar

    2016-04-01

    Full Text Available Aim: The aim of this study is to test the potency of bovine serum albumin (BSA conjugated ampicillin (AMP and enrofloxacin (ENR antigens in eliciting an immune response in rats using indirect competitive enzyme-linked immunosorbent assay (icELISA. Materials and Methods: AMP and ENR antibiotics were conjugated with BSA by carbodiimide reaction using 1-ethyl-3-(3-dimethylaminopropyl carbodiimide (EDC as a cross-linker. The successful conjugation was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sprague-Dawley rats were immunized with the conjugates and blood samples were collected serially at 15 days time interval after first immunization plus first booster, second booster, third booster, and the fourth sampling was done 1½ month after the third booster. The antibody titres in the antisera of each antibiotic in all the four immunization cycles (ICs were determined by an icELISA at various serum dilutions ranging from 1/100 to 1/6400. Results: Analysis of antibiotic-BSA conjugates by sodium dodecyl sulfate polyacrylamide gel electrophoresis and coomassie blue staining revealed high molecular weight bands of 85 kDa and 74 kDa for AMP-BSA and ENR-BSA respectively when compared to 68 kDa band of BSA. Both the antibiotic conjugates elicited a good immune response in rats but comparatively the response was more with AMP-BSA conjugate than ENR-BSA conjugate. Maximum optical density 450 value of 2.577 was recorded for AMP-BSA antisera, and 1.723 was recorded for ENR-BSA antisera at 1/100th antiserum dilution in third IC. Conclusion: AMP and ENR antibiotics proved to be good immunogens when conjugated to BSA by carbodiimide reaction with EDC as crosslinker. The polyclonal antibodies produced can be employed for detecting AMP and ENR residues in milk and urine samples.

  2. Systemic and Mucosal Antibody Responses to Soluble and Nanoparticle-Conjugated Antigens Administered Intranasally

    Directory of Open Access Journals (Sweden)

    Savannah E. Howe

    2016-10-01

    Full Text Available Nanoparticles (NPs are increasingly being used for drug delivery, as well as antigen carriers and immunostimulants for the purpose of developing vaccines. In this work, we examined how intranasal (i.n. priming followed by i.n. or subcutaneous (s.c. boosting immunization affects the humoral immune response to chicken ovalbumin (Ova and Ova conjugated to 20 nm NPs (NP-Ova. We show that i.n. priming with 20 mg of soluble Ova, a dose known to trigger oral tolerance when administered via gastric gavage, induced substantial systemic IgG1 and IgG2c, as well as mucosal antibodies. These responses were further boosted following a s.c. immunization with Ova and complete Freund’s adjuvant (Ova+CFA. In contrast, 100 µg of Ova delivered via NPs induced an IgG1-dominated systemic response, and primed the intestinal mucosa for secretion of IgA. Following a secondary s.c. or i.n. immunization with Ova+CFA or NP-Ova, systemic IgG1 titers significantly increased, and serum IgG2c and intestinal antibodies were induced in mice primed nasally with NP-Ova. Only Ova- and NP-Ova-primed mice that were s.c.-boosted exhibited substantial systemic and mucosal titers for up to 6 months after priming, whereas the antibodies of i.n.-boosted mice declined over time. Our results indicate that although the amount of Ova delivered by NPs was 1000-fold less than Ova delivered in soluble form, the antigen-specific antibody responses, both systemic and mucosal, are essentially identical by 6 months following the initial priming immunization. Additionally, both i.n.- and s.c.-boosting strategies for NP-Ova-primed mice were capable of inducing a polarized Th1/Th2 immune response, as well as intestinal antibodies; however, it is only by using a heterogeneous prime-boost strategy that long-lasting antibody responses were initiated. These results provide valuable insight for future mucosal vaccine development, as well as furthering our understanding of mucosal antibody responses.

  3. Imaging of Hsp70-positive tumors with cmHsp70.1 antibody-conjugated gold nanoparticles

    Science.gov (United States)

    Gehrmann, Mathias K; Kimm, Melanie A; Stangl, Stefan; Schmid, Thomas E; Noël, Peter B; Rummeny, Ernst J; Multhoff, Gabriele

    2015-01-01

    Real-time imaging of small tumors is still one of the challenges in cancer diagnosis, prognosis, and monitoring of clinical outcome. Targeting novel biomarkers that are selectively expressed on a large variety of different tumors but not normal cells has the potential to improve the imaging capacity of existing methods such as computed tomography. Herein, we present a novel technique using cmHsp70.1 monoclonal antibody-conjugated spherical gold nanoparticles for quantification of the targeted uptake of gold nanoparticles into membrane Hsp70-positive tumor cells. Upon binding, cmHsp70.1-conjugated gold nanoparticles but not nanoparticles coupled to an isotype-matched IgG1 antibody or empty nanoparticles are rapidly taken up by highly malignant Hsp70 membrane-positive mouse tumor cells. After 24 hours, the cmHsp70.1-conjugated gold nanoparticles are found to be enriched in the perinuclear region. Specificity for membrane Hsp70 was shown by using an Hsp70 knockout tumor cell system. Toxic side effects of the cmHsp70.1-conjugated nanoparticles are not observed at a concentration of 1–10 µg/mL. Experiments are ongoing to evaluate whether cmHsp70.1 antibody-conjugated gold nanoparticles are suitable for the detection of membrane-Hsp70-positive tumors in vivo. PMID:26392771

  4. Preclinical and clinical pharmacokinetic/pharmacodynamic considerations for antibody-drug conjugates.

    Science.gov (United States)

    Sapra, Puja; Betts, Alison; Boni, Joseph

    2013-09-01

    Antibody-drug conjugates (ADCs) represent a promising therapeutic modality for the clinical management of cancer. Here we discuss the clinical pharmacology and safety of ADCs that are either approved or in late stages of clinical development. We have taken examples of ADCs employing either DNA damaging payloads (such as calicheamicin) or tubulin depolymerizing agents (such as auristatins and maytansinoids) to discuss the impact of dose and dosage intervals on pharmacokinetics/pharmacodynamics (PK/PD) and safety of ADCs. We also discuss the development of PK/PD models that were validated using preclinical and clinical data from two approved ADCs (ado-trastuzumab emtansine (T-DM1, Kadcyla™) and brentuximab vedotin (SGN-35, Adcetris™). These models could be used to predict clinical efficacious doses of ADCs.

  5. Control Strategy for Small Molecule Impurities in Antibody-Drug Conjugates.

    Science.gov (United States)

    Gong, Hai H; Ihle, Nathan; Jones, Michael T; Kelly, Kathleen; Kott, Laila; Raglione, Thomas; Whitlock, Scott; Zhang, Qunying; Zheng, Jie

    2018-04-01

    Antibody-drug conjugates (ADCs) are an emerging class of biopharmaceuticals. As such, there are no specific guidelines addressing impurity limits and qualification requirements. The current ICH guidelines on impurities, Q3A (Impurities in New Drug Substances), Q3B (Impurities in New Drug Products), and Q6B (Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products) do not adequately address how to assess small molecule impurities in ADCs. The International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) formed an impurities working group (IWG) to discuss this issue. This white paper presents a strategy for evaluating the impact of small molecule impurities in ADCs. This strategy suggests a science-based approach that can be applied to the design of control systems for ADC therapeutics. The key principles that form the basis for this strategy include the significant difference in molecular weights between small molecule impurities and the ADC, the conjugation potential of the small molecule impurities, and the typical dosing concentrations and dosing schedule. The result is that exposure to small impurities in ADCs is so low as to often pose little or no significant safety risk.

  6. Site-specific conjugation of single domain antibodies to liposomes enhances photosensitizer uptake and photodynamic therapy efficacy

    NARCIS (Netherlands)

    Broekgaarden, M.; van Vught, R.; Oliveira, S.; Roovers, R. C.; van Bergen En Henegouwen, P. M. P.; Pieters, R. J.; van Gulik, T. M.; Breukink, E.; Heger, M.

    2016-01-01

    Photodynamic therapy for therapy-resistant cancers will greatly benefit from targeted delivery of tumor photosensitizing agents. In this study, a strategy for the site-specific conjugation of single domain antibodies onto liposomes containing the photosensitizer zinc phthalocyanine was developed and

  7. Site-specific conjugation of single domain antibodies to liposomes enhances photosensitizer uptake and photodynamic therapy efficacy.

    Science.gov (United States)

    Broekgaarden, M; van Vught, R; Oliveira, S; Roovers, R C; van Bergen en Henegouwen, P M P; Pieters, R J; Van Gulik, T M; Breukink, E; Heger, M

    2016-03-28

    Photodynamic therapy for therapy-resistant cancers will greatly benefit from targeted delivery of tumor photosensitizing agents. In this study, a strategy for the site-specific conjugation of single domain antibodies onto liposomes containing the photosensitizer zinc phthalocyanine was developed and tested.

  8. High-throughput oxidation screen of antibody-drug conjugates by analytical protein A chromatography following IdeS digest.

    Science.gov (United States)

    Buecheler, Jakob W; Winzer, Matthias; Weber, Christian; Gieseler, Henning

    2018-05-01

    Oxidation of protein therapeutics is a major chemical degradation pathway which may impact bioactivity, serum half-life and stability. Therefore, oxidation is a relevant parameter which has to be monitored throughout formulation development. Methods such as HIC, RPLC and LC/MS achieve a separation of oxidized and non-oxidized species by differences in hydrophobicity. Antibody-drug conjugates (ADC) although are highly more complex due to the heterogeneity in linker, drug, drug-to-antibody ratio (DAR) and conjugation site. The analytical protein A chromatography can provide a simple and fast alternative to these common methods. A miniature analytical protein A chromatography method in combination with an IdeS digest was developed to analyse ADCs. The IdeS digest efficiency of an IgG1 was monitored using SEC-HPLC and non-reducing SDS-PAGE. An antibody-fluorescent dye conjugate was conjugated at different dye-to-antibody ratios as model construct to mimic an ADC. With IdeS, an almost complete digest of a model IgG1 can be achieved (digested protein amount >98%). This enables subsequent analytical protein A chromatography, which consequently eliminates any interference of payload with the stationary phase. A novel high-throughput method for an interchain cysteine-linked ADC oxidation screens during formulation development was developed. © 2018 Royal Pharmaceutical Society.

  9. A simplified suite of methods to evaluate chelator conjugation of antibodies: effects on hydrodynamic radius and biodistribution

    International Nuclear Information System (INIS)

    Al-Ejeh, Fares; Darby, Jocelyn M.; Thierry, Benjamin; Brown, Michael P.

    2009-01-01

    Introduction: Antibodies covalently conjugated with chelators such as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) are required for radioimmunoscintigraphy and radioimmunotherapy, which are of growing importance in cancer medicine. Method: Here, we report a suite of simple methods that provide a preclinical assessment package for evaluating the effects of DOTA conjugation on the in vitro and in vivo performance of monoclonal antibodies. We exemplify the use of these methods by investigating the effects of DOTA conjugation on the biochemical properties of the DAB4 clone of the La/SSB-specific murine monoclonal autoantibody, APOMAB (registered) , which is a novel malignant cell death ligand. Results: We have developed a 96-well microtiter-plate assay to measure directly the concentration of DOTA and other chelators in antibody-chelator conjugate solutions. Coupled with a commercial assay for measuring protein concentration, the dual microtiter-plate method can rapidly determine chelator/antibody ratios in the same plate. The biochemical properties of DAB4 immunoconjugates were altered as the DOTA/Ab ratio increased so that: (i) mass/charge ratio decreased; (ii) hydrodynamic radius increased; (iii) antibody immunoactivity decreased; (iv) rate of chelation of metal ions and specific radioactivity both increased and in vivo, (v) tumor uptake decreased as nonspecific uptake by liver and spleen increased. Conclusion: This simplified suite of methods readily identifies biochemical characteristics of the DOTA-immunoconjugates such as hydrodynamic diameter and decreased mass/charge ratio associated with compromised immunotargeting efficiency and, thus, may prove useful for optimizing conjugation procedures in order to maximize immunoconjugate-mediated radioimmunoscintigraphy and radioimmunotherapy.

  10. Template-directed covalent conjugation of DNA to native antibodies, transferrin and other metal-binding proteins

    Science.gov (United States)

    Rosen, Christian B.; Kodal, Anne L. B.; Nielsen, Jesper S.; Schaffert, David H.; Scavenius, Carsten; Okholm, Anders H.; Voigt, Niels V.; Enghild, Jan J.; Kjems, Jørgen; Tørring, Thomas; Gothelf, Kurt V.

    2014-09-01

    DNA-protein conjugates are important in bioanalytical chemistry, molecular diagnostics and bionanotechnology, as the DNA provides a unique handle to identify, functionalize or otherwise manipulate proteins. To maintain protein activity, conjugation of a single DNA handle to a specific location on the protein is often needed. However, preparing such high-quality site-specific conjugates often requires genetically engineered proteins, which is a laborious and technically challenging approach. Here we demonstrate a simpler method to create site-selective DNA-protein conjugates. Using a guiding DNA strand modified with a metal-binding functionality, we directed a second DNA strand to the vicinity of a metal-binding site of His6-tagged or wild-type metal-binding proteins, such as serotransferrin, where it subsequently reacted with lysine residues at that site. This method, DNA-templated protein conjugation, facilitates the production of site-selective protein conjugates, and also conjugation to IgG1 antibodies via a histidine cluster in the constant domain.

  11. Antibody drug conjugates and bystander killing: is antigen-dependent internalisation required?

    Science.gov (United States)

    Staudacher, Alexander H; Brown, Michael P

    2017-12-05

    Antibody drug conjugates (ADCs) employ the exquisite specificity of tumour-specific monoclonal antibodies (mAb) for the targeted delivery of highly potent cytotoxic drugs to the tumour site. The chemistry of the linker, which connects the drug to the mAb, determines how and when the drug is released from the mAb. This, as well as the chemistry of the drug, can dictate whether the drug can diffuse into surrounding cells, resulting in 'bystander killing'. Initially, any bystander killing mechanism of action of an ADC was understood to involve an essential sequence of steps beginning with surface antigen targeting, internalisation, intracellular linker cleavage, drug release, and diffusion of drug away from the targeted cell. However, recent studies indicate that, depending on the linker and drug combination, this mechanism may not be essential and ADCs can be cleaved extracellularly or via other mechanisms. In this minireview, we will examine the role of bystander killing by ADCs and explore the emerging evidence of how this can occur independently of internalisation.

  12. Emission variation in infrared (CdSeTe)/ZnS quantum dots conjugated to antibodies

    Science.gov (United States)

    Jaramillo Gómez, J. A.; Casas Espinola, J. L.; Douda, J.

    2014-11-01

    The paper presents the photoluminescence (PL) and Raman scattering investigations of infrared CdSeTe/ZnS quantum dots (QDs) with emission at 800 nm (1.60 eV) in nonconjugated states and after the conjugation to the anti-papilloma virus antibodies (Ab). The Raman scattering study has shown that the CdSeTe core includes two layers with different material compositions such as: CdSe0.5Te0.5 and CdSe0.7Te0.3. PL spectra of nonconjugated CdSeTe/ZnS QDs are characterized by two Gaussian shape PL bands related to exciton emission in the CdSeTe core and in intermediate layer at the core/shell interface. PL spectra of bioconjugated QDs have changed essentially: the main PL band related to the core emission shifts into high energy and become asymmetric. The energy diagram of double core/shell CdSeTe/ZnS QDs has been analyzed to explain the PL spectrum of nonconjugated QDs and its transformation at the bioconjugation to the papiloma virus antibodies. It is shown that the PL spectrum transformation in bioconjugated QDs can be a powerful technique for biology and medicine.

  13. Emission variation in infrared (CdSeTe)/ZnS quantum dots conjugated to antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jaramillo Gómez, J.A. [UPIITA – Instituto Politécnico Nacional, México D. F. 07320, México (Mexico); Casas Espinola, J.L., E-mail: jlcasas@esfm.ipn.mx [ESFM – Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Douda, J. [UPIITA – Instituto Politécnico Nacional, México D. F. 07320, México (Mexico)

    2014-11-15

    The paper presents the photoluminescence (PL) and Raman scattering investigations of infrared CdSeTe/ZnS quantum dots (QDs) with emission at 800 nm (1.60 eV) in nonconjugated states and after the conjugation to the anti-papilloma virus antibodies (Ab). The Raman scattering study has shown that the CdSeTe core includes two layers with different material compositions such as: CdSe{sub 0.5}Te{sub 0.5} and CdSe{sub 0.7}Te{sub 0.3}. PL spectra of nonconjugated CdSeTe/ZnS QDs are characterized by two Gaussian shape PL bands related to exciton emission in the CdSeTe core and in intermediate layer at the core/shell interface. PL spectra of bioconjugated QDs have changed essentially: the main PL band related to the core emission shifts into high energy and become asymmetric. The energy diagram of double core/shell CdSeTe/ZnS QDs has been analyzed to explain the PL spectrum of nonconjugated QDs and its transformation at the bioconjugation to the papiloma virus antibodies. It is shown that the PL spectrum transformation in bioconjugated QDs can be a powerful technique for biology and medicine.

  14. Treatment with belimumab in systemic lupus erythematosus does not impair antibody response to 13-valent pneumococcal conjugate vaccine.

    Science.gov (United States)

    Nagel, J; Saxne, T; Geborek, P; Bengtsson, A A; Jacobsen, S; Svaerke Joergensen, C; Nilsson, J-Å; Skattum, L; Jönsen, A; Kapetanovic, M C

    2017-09-01

    Background/purpose The objective of this study was to explore the impact of systemic lupus erythematosus and belimumab given in addition to standard of care therapy on 13-valent conjugated pneumococcal vaccine (PCV13) response. Methods Forty-seven systemic lupus erythematosus patients and 21 healthy controls were immunized with a single dose of 13-valent conjugated pneumococcal vaccine. Forty systemic lupus erythematosus patients were treated with traditional disease-modifying anti rheumatic drugs, 11 of those received belimumab in addition, and 32 patients were treated with concomitant prednisolone. Quantification of serotype specific IgG levels to 12 pneumococcal capsular polysaccharides was performed in serum taken before and four to six weeks after vaccination using multiplex fluorescent microsphere immunoassay. IgG levels against serotypes 23F and 6B were also analyzed using standard enzyme-linked immunosorbent assays. Opsonophagocytic assay was performed on serotype 23F to evaluate the functionality of the antibodies. Pre- and post-vaccination log transformed antibody levels were compared to determine the impact of systemic lupus erythematosus diagnosis and different treatments on antibody response. Results Systemic lupus erythematosus patients as a group showed lower post-vaccination antibody levels and lower fold increase of antibody levels after vaccination compared to controls ( p = 0.02 and p = 0.009, respectively). Systemic lupus erythematosus patients treated with belimumab in addition to standard of care therapy or with only hydroxychloroquine did not differ compared to controls, whereas the other treatment groups had significantly lower fold increase of post-vaccination antibody levels. Higher age was associated with lower post-vaccination antibody levels among systemic lupus erythematosus patients. Conclusion Belimumab given in addition to traditional disease-modifying anti rheumatic drugs or prednisolone did not further impair antibody

  15. Intratumoral delivery of CpG-conjugated anti-MUC1 antibody enhances NK cell anti-tumor activity.

    Science.gov (United States)

    Schettini, Jorge; Kidiyoor, Amritha; Besmer, Dahlia M; Tinder, Teresa L; Roy, Lopamudra Das; Lustgarten, Joseph; Gendler, Sandra J; Mukherjee, Pinku

    2012-11-01

    Monoclonal antibodies (mAbs) against tumor-associated antigens are useful anticancer agents. Antibody-dependent cellular cytotoxicity (ADCC) is one of the major mechanisms responsible for initiating natural killer cell (NK)-mediated killing of tumors. However, the regulation of ADCC via NK cells is poorly understood. We have investigated the cytolytic activity of NK cells against pancreatic cancer cells that were coated with an antibody directed against the human tumor antigen, Mucin-1 designated HMFG-2, either alone or conjugated to CpG oligodeoxynucleotide (CpG ODN). Conjugated antibodies were tested for their ability to elicit ADCC in vitro and in vivo against pancreatic cancer cells. NK cells cultured in the presence of immobilized CpG ODN, HMFG-2 Ab, or CpG ODN-conjugated HMFG-2 Ab were able to up-regulate perforin similarly. Interestingly, a significant higher ADCC was observed when CpG ODN-conjugated HMFG-2-coated tumor cells were co-cultured with NK cells compared to unconjugated HMFG-2 Ab or CpG ODN alone. Moreover, MyD88-deficient NK cells can perform ADCC in vitro. Furthermore, intratumoral injections of CpG ODN-conjugated HMFG-2 induced a significant reduction in tumor burden in vivo in an established model of pancreatic tumor in nude mice compared to CpG ODN or the HMFG-2 alone. Depletion of macrophages or NK cells before treatment confirmed that both cells were required for the anti-tumor response in vivo. Results also suggest that CpG ODN and HMFG-2 Ab could be sensed by NK cells on the mAb-coated tumor cells triggering enhanced ADCC in vitro and in vivo.

  16. HER2 monoclonal antibodies that do not interfere with receptor heterodimerization-mediated signaling induce effective internalization and represent valuable components for rational antibody-drug conjugate design.

    Science.gov (United States)

    de Goeij, Bart E C G; Peipp, Matthias; de Haij, Simone; van den Brink, Edward N; Kellner, Christian; Riedl, Thilo; de Jong, Rob; Vink, Tom; Strumane, Kristin; Bleeker, Wim K; Parren, Paul W H I

    2014-01-01

    The human epidermal growth factor receptor (HER)2 provides an excellent target for selective delivery of cytotoxic drugs to tumor cells by antibody-drug conjugates (ADC) as has been clinically validated by ado-trastuzumab emtansine (Kadcyla(TM)). While selecting a suitable antibody for an ADC approach often takes specificity and efficient antibody-target complex internalization into account, the characteristics of the optimal antibody candidate remain poorly understood. We studied a large panel of human HER2 antibodies to identify the characteristics that make them most suitable for an ADC approach. As a model toxin, amenable to in vitro high-throughput screening, we employed Pseudomonas exotoxin A (ETA') fused to an anti-kappa light chain domain antibody. Cytotoxicity induced by HER2 antibodies, which were thus non-covalently linked to ETA', was assessed for high and low HER2 expressing tumor cell lines and correlated with internalization and downmodulation of HER2 antibody-target complexes. Our results demonstrate that HER2 antibodies that do not inhibit heterodimerization of HER2 with related ErbB receptors internalize more efficiently and show greater ETA'-mediated cytotoxicity than antibodies that do inhibit such heterodimerization. Moreover, stimulation with ErbB ligand significantly enhanced ADC-mediated tumor kill by antibodies that do not inhibit HER2 heterodimerization. This suggests that the formation of HER2/ErbB-heterodimers enhances ADC internalization and subsequent killing of tumor cells. Our study indicates that selecting HER2 ADCs that allow piggybacking of HER2 onto other ErbB receptors provides an attractive strategy for increasing ADC delivery and tumor cell killing capacity to both high and low HER2 expressing tumor cells.

  17. Real-Time Analysis on Drug-Antibody Ratio of Antibody-Drug Conjugates for Synthesis, Process Optimization, and Quality Control.

    Science.gov (United States)

    Tang, Yubo; Tang, Feng; Yang, Yang; Zhao, Lei; Zhou, Hu; Dong, Jinhua; Huang, Wei

    2017-08-10

    Drug-antibody ratio (DAR) of antibody-drug conjugates (ADCs) is important for their therapeutic efficacy and pharmacokinetics, therefore control on DAR in synthesis process is a key for ADC quality control. Although various analytical methods were reported, the real-time monitoring on DAR is still a challenge because time-consuming sample preparation is usually needed during the analysis. Antibody deglycosylation of ADC simplifies DAR measurement, however long-time PNGaseF digestion for deglycosylation hampers the real-time detection. Here, we report a rapid DAR analysis within 15 min by robust deglycosylation treatment and LC-MS detection that enables real-time DAR monitoring for optimization on ADC synthetic process. With this approach, we were able to screen suitable conjugation conditions efficiently and afford the ADCs with expected DARs. To the best of our knowledge, this is the first report on real-time DAR analysis of ADCs for conjugation optimization and quality control, compatible with random lysine-linked ADCs, glycosite-specific ADCs, and the complicated dual-payload ADCs.

  18. Outer membrane protein complex of Meningococcus enhances the antipolysaccharide antibody response to pneumococcal polysaccharide-CRM₁₉₇ conjugate vaccine.

    Science.gov (United States)

    Lai, Zengzu; Schreiber, John R

    2011-05-01

    Bacterial polysaccharides (PS) are T cell-independent antigens that do not induce immunologic memory and are poor immunogens in infants. Conjugate vaccines in which the PS is covalently linked to a carrier protein have enhanced immunogenicity that resembles that of T cell-dependent antigens. The Haemophilus influenzae type b (Hib) conjugate vaccine, which uses the outer membrane protein complex (OMPC) from meningococcus as a carrier protein, elicits protective levels of anti-capsular PS antibody (Ab) after a single dose, in contrast to other conjugate vaccines, which require multiple doses. We have previously shown that OMPC robustly engages Toll-like receptor 2 (TLR2) and enhances the early anti-Hib PS Ab titer associated with an increase in TLR2-mediated induction of cytokines. We now show that the addition of OMPC to the 7-valent pneumococcal PS-CRM₁₉₇ conjugate vaccine during immunization significantly increases the anti-PS IgG and IgM responses to most serotypes of pneumococcus contained in the vaccine. The addition of OMPC also increased the likelihood of anti-PS IgG3 production against serotypes 4, 6B, 9V, 18C, 19F, and 23F. Splenocytes from mice who had received OMPC with the pneumococcal conjugate vaccine produced significantly more interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) than splenocytes from mice who received phosphate-buffered saline (PBS) plus the conjugate vaccine. We conclude that OMPC enhances the anti-PS Ab response to pneumococcal PS-CRM₁₉₇ conjugate vaccine, an effect associated with a distinct change in cytokine profile. It may be possible to reduce the number of conjugate vaccine doses required to achieve protective Ab levels by priming with adjuvants that are TLR2 ligands.

  19. Imaging of Hsp70-positive tumors with cmHsp70.1 antibody-conjugated gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Gehrmann MK

    2015-09-01

    Full Text Available Mathias K Gehrmann,1 Melanie A Kimm,2 Stefan Stangl,1 Thomas E Schmid,1 Peter B Noël,2 Ernst J Rummeny,2 Gabriele Multhoff11Department of Radiation Oncology, 2Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, GermanyAbstract: Real-time imaging of small tumors is still one of the challenges in cancer diagnosis, prognosis, and monitoring of clinical outcome. Targeting novel biomarkers that are selectively expressed on a large variety of different tumors but not normal cells has the potential to improve the imaging capacity of existing methods such as computed tomography. Herein, we present a novel technique using cmHsp70.1 monoclonal antibody-conjugated spherical gold nanoparticles for quantification of the targeted uptake of gold nanoparticles into membrane Hsp70-positive tumor cells. Upon binding, cmHsp70.1-conjugated gold nanoparticles but not nanoparticles coupled to an isotype-matched IgG1 antibody or empty nanoparticles are rapidly taken up by highly malignant Hsp70 membrane-positive mouse tumor cells. After 24 hours, the cmHsp70.1-conjugated gold nanoparticles are found to be enriched in the perinuclear region. Specificity for membrane Hsp70 was shown by using an Hsp70 knockout tumor cell system. Toxic side effects of the cmHsp70.1-conjugated nanoparticles are not observed at a concentration of 1–10 µg/mL. Experiments are ongoing to evaluate whether cmHsp70.1 antibody-conjugated gold nanoparticles are suitable for the detection of membrane-Hsp70-positive tumors in vivo.Keywords: heat shock protein 70, tumor biomarker, theranostics, multimodal CT, multispectral CT, k-edge

  20. Treatment with belimumab in systemic lupus erythematosus does not impair antibody response to 13-valent pneumococcal conjugate vaccine

    DEFF Research Database (Denmark)

    Nagel, J.; Saxne, T.; Geborek, P.

    2017-01-01

    enzyme-linked immunosorbent assays. Opsonophagocytic assay was performed on serotype 23F to evaluate the functionality of the antibodies. Pre- and post-vaccination log transformed antibody levels were compared to determine the impact of systemic lupus erythematosus diagnosis and different treatments......Background/purpose The objective of this study was to explore the impact of systemic lupus erythematosus and belimumab given in addition to standard of care therapy on 13-valent conjugated pneumococcal vaccine (PCV13) response. Methods Forty-seven systemic lupus erythematosus patients and 21...... healthy controls were immunized with a single dose of 13-valent conjugated pneumococcal vaccine. Forty systemic lupus erythematosus patients were treated with traditional disease-modifying anti rheumatic drugs, 11 of those received belimumab in addition, and 32 patients were treated with concomitant...

  1. World Antibody-Drug Conjugate Summit, October 15-16, 2013, San Francisco, CA.

    Science.gov (United States)

    Klinguer-Hamour, Christine; Strop, Pavel; Shah, Dhaval K; Ducry, Laurent; Xu, April; Beck, Alain

    2014-01-01

    The World Antibody-Drug Conjugate (WADC) Summits organized by Hanson Wade are currently the largest meetings fully dedicated to ADCs. The first global ADC Summit was organized in Boston in October 2010. Since 2011, two WADC are held every year in Frankfurt and San Francisco, respectively. The 2013 WADC San Francisco event was structured around plenary sessions with keynote speakers from AbbVie, Agensys, ImmunoGen, Immunomedics, Genentech, Pfizer and Seattle Genetics. Parallel tracks were also organized addressing ADC discovery, development and optimization of chemistry, manufacturing and control (CMC) issues. Discovery and process scientists, regulatory experts (US Food and Drug Administration), academics and clinicians were present, including representatives from biotechnology firms (Concortis, CytomX Therapeutics, Glykos, Evonik, Igenica, Innate Pharma, Mersana Therapeutics, Polytherics, Quanta Biodesign, Redwood Bioscience, Sutro Biopharma, SynAffix), pharmaceutical companies (Amgen, Genmab, Johnson and Johnson, MedImmune, Novartis, Progenics, Takeda) and contract research or manufacturing organizations (Baxter, Bayer, BSP Pharmaceuticals, Fujifilm/Diosynth, Lonza, Pierre Fabre Contract Manufacturing, Piramal, SAFC, SafeBridge).

  2. A mechanistic tumor penetration model to guide antibody drug conjugate design.

    Directory of Open Access Journals (Sweden)

    Christina Vasalou

    Full Text Available Antibody drug conjugates (ADCs represent novel anti-cancer modalities engineered to specifically target and kill tumor cells expressing corresponding antigens. Due to their large size and their complex kinetics, these therapeutic agents often face heterogeneous distributions in tumors, leading to large untargeted regions that escape therapy. We present a modeling framework which includes the systemic distribution, vascular permeability, interstitial transport, as well as binding and payload release kinetics of ADC-therapeutic agents in mouse xenografts. We focused, in particular, on receptor dynamics such as endocytic trafficking mechanisms within cancer cells, to simulate their impact on tumor mass shrinkage upon ADC administration. Our model identified undesirable tumor properties that can impair ADC tissue homogeneity, further compromising ADC success, and explored ADC design optimization scenarios to counteract upon such unfavorable intrinsic tumor tissue attributes. We further demonstrated the profound impact of cytotoxic payload release mechanisms and the role of bystander killing effects on tumor shrinkage. This model platform affords a customizable simulation environment which can aid with experimental data interpretation and the design of ADC therapeutic treatments.

  3. Discovery of Peptidomimetic Antibody-Drug Conjugate Linkers with Enhanced Protease Specificity.

    Science.gov (United States)

    Wei, BinQing; Gunzner-Toste, Janet; Yao, Hui; Wang, Tao; Wang, Jing; Xu, Zijin; Chen, Jinhua; Wai, John; Nonomiya, Jim; Tsai, Siao Ping; Chuh, Josefa; Kozak, Katherine R; Liu, Yichin; Yu, Shang-Fan; Lau, Jeff; Li, Guangmin; Phillips, Gail D; Leipold, Doug; Kamath, Amrita; Su, Dian; Xu, Keyang; Eigenbrot, Charles; Steinbacher, Stefan; Ohri, Rachana; Raab, Helga; Staben, Leanna R; Zhao, Guiling; Flygare, John A; Pillow, Thomas H; Verma, Vishal; Masterson, Luke A; Howard, Philip W; Safina, Brian

    2018-02-08

    Antibody-drug conjugates (ADCs) have become an important therapeutic modality for oncology, with three approved by the FDA and over 60 others in clinical trials. Despite the progress, improvements in ADC therapeutic index are desired. Peptide-based ADC linkers that are cleaved by lysosomal proteases have shown sufficient stability in serum and effective payload-release in targeted cells. If the linker can be preferentially hydrolyzed by tumor-specific proteases, safety margin may improve. However, the use of peptide-based linkers limits our ability to modulate protease specificity. Here we report the structure-guided discovery of novel, nonpeptidic ADC linkers. We show that a cyclobutane-1,1-dicarboxamide-containing linker is hydrolyzed predominantly by cathepsin B while the valine-citrulline dipeptide linker is not. ADCs bearing the nonpeptidic linker are as efficacious and stable in vivo as those with the dipeptide linker. Our results strongly support the application of the peptidomimetic linker and present new opportunities for improving the selectivity of ADCs.

  4. In-Depth Comparison of Lysine-Based Antibody-Drug Conjugates Prepared on Solid Support Versus in Solution

    Directory of Open Access Journals (Sweden)

    Keith J. Arlotta

    2018-01-01

    Full Text Available Antibody drug conjugates are a rapidly growing form of targeted chemotherapeutics. As companies and researchers move to develop new antibody–drug conjugate (ADC candidates, high-throughput methods will become increasingly common. Here we use advanced characterization techniques to assess two trastuzumab-DM1 (T-DM1 ADCs; one produced using Protein A immobilization and the other produced in solution. Following determination of payload site and distribution with liquid chromatography-mass spectrometry (LC/MS, thermal stability, heat-induced aggregation, tertiary structure, and binding affinity were characterized using differential scanning calorimetry (DSC, dynamic light scattering (DLS, Raman spectroscopy, and isothermal titration calorimetry (ITC, respectively. Small differences in the thermal stability of the CH2 domain of the antibody as well as aggregation onset temperatures were observed from DSC and DLS, respectively. However, no significant differences in secondary and tertiary structure were observed with Raman spectroscopy, or binding affinity as measured by ITC. Lysine-based ADC conjugation produces an innately heterogeneous population that can generate significant variability in the results of sensitive characterization techniques. Characterization of these ADCs indicated nominal differences in thermal stability but not in tertiary structure or binding affinity. Our results lead us to conclude that lysine-based ADCs synthesized following Protein A immobilization, common in small-scale conjugations, are highly similar to equivalent ADCs produced in larger scale, solution-based methods.

  5. A novel multi-walled carbon nanotube-based antibody conjugate for quantitative and semi-quantitative lateral flow assays.

    Science.gov (United States)

    Sun, Wenjuan; Hu, Xiaolong; Liu, Jia; Zhang, Yurong; Lu, Jianzhong; Zeng, Libo

    2017-10-01

    In this study, the multi-walled carbon nanotubes (MWCNTs) were applied in lateral flow strips (LFS) for semi-quantitative and quantitative assays. Firstly, the solubility of MWCNTs was improved using various surfactants to enhance their biocompatibility for practical application. The dispersed MWCNTs were conjugated with the methamphetamine (MET) antibody in a non-covalent manner and then manufactured into the LFS for the quantitative detection of MET. The MWCNTs-based lateral flow assay (MWCNTs-LFA) exhibited an excellent linear relationship between the values of test line and MET when its concentration ranges from 62.5 to 1500 ng/mL. The sensitivity of the LFS was evaluated by conjugating MWCNTs with HCG antibody and the MWCNTs conjugated method is 10 times more sensitive than the one conjugated with classical colloidal gold nanoparticles. Taken together, our data demonstrate that MWCNTs-LFA is a more sensitive and reliable assay for semi-quantitative and quantitative detection which can be used in forensic analysis.

  6. Engineering of ultra-small diagnostic nanoprobes through oriented conjugation of single-domain antibodies and quantum dots

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Alyona Sukhanova, Klervi Even-Desrumeaux, Patrick Chames, Daniel Baty, Mikhail Artemyev, Vladimir Oleinikov & Igor Nabiev ### Abstract Nanoparticle-based biodetection commonly employs monoclonal antibodies (mAbs) for targeting. Although several types of conjugates have been used for biomarker labeling, the large size of mAbs limits the number of ligands per nanoparticle, impedes their intratumoral distribution, and limits intracellular penetration. Furthermore, the condition...

  7. A Rapid Detection Method of Brucella with Quantum Dots and Magnetic Beads Conjugated with Different Polyclonal Antibodies

    Science.gov (United States)

    Song, Dandan; Qu, Xiaofeng; Liu, Yushen; Li, Li; Yin, Dehui; Li, Juan; Xu, Kun; Xie, Renguo; Zhai, Yue; Zhang, Huiwen; Bao, Hao; Zhao, Chao; Wang, Juan; Song, Xiuling; Song, Wenzhi

    2017-03-01

    Brucella spp. are facultative intracellular bacteria that cause zoonotic disease of brucellosis worldwide. Traditional methods for detection of Brucella spp. take 48-72 h that does not meet the need of rapid detection. Herein, a new rapid detection method of Brucella was developed based on polyclonal antibody-conjugating quantum dots and antibody-modified magnetic beads. First, polyclonal antibodies IgG and IgY were prepared and then the antibody conjugated with quantum dots (QDs) and immunomagnetic beads (IMB), respectively, which were activated by N-(3-dimethylaminopropyl)- N'-ethylcar-bodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to form probes. We used the IMB probe to separate the Brucella and labeled by the QD probe, and then detected the fluorescence intensity with a fluorescence spectrometer. The detection method takes 105 min with a limit of detection of 103 CFU/mL and ranges from 10 to 105 CFU/mL ( R 2 = 0.9983), and it can be well used in real samples.

  8. Antibody persistence following meningococcal C conjugate vaccination in children and adolescents infected with human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Ana Cristina Cisne Frota

    Full Text Available Abstract Objective: HIV-infected individuals (HIVI are threatened by meningococcal infection and presented lower response to vaccines. Data are scarce on long-term persistence of human serum bactericidal antibody (hSBA after a meningococcal C conjugate (MCC vaccine in HIVI youth; the authors aimed to describe this persistence in HIVI. Methods: HIVI and HIV uninfected individuals (HIVU, aged 2–18 years, CD4 >15% were recruited. Seroprotection (hSBA ≥1:4 at baseline and at 12–18 months after immunization was evaluated and the association of the different factors with the long-term persistence was calculated using logistic regression. Results: A total of 145 HIVI, 50 HIVU were recruited and immunized, and their median age was 11 years (median age in HIVI group was 12 years, and 10 years in HIVU group, p-value = 0.02. 85 HIVI (44% had undetectable viral load (UVL. Seroprotection rate was 27.2%: 24.1% in HIVI and 36% in HIVU 12–18 months after immunization (p = 0.14. Baseline immunity (odds ratio [OR] = 70.70, 95% CI: 65.2–766.6; UVL at entry (OR: 2.87, 95% CI: 0.96–8.62 and lower family income (OR: 0.09, 95% CI: 0.01–0.69 were associated with seroprotection among HIVI. Conclusion: Seroprotection at 12–18 months after single dose of MCC was low for both groups, and higher among individuals who presented baseline immunity. Among HIVI, vaccine should be administered after UVL is achieved.

  9. Modulation of Macropinocytosis-Mediated Internalization Decreases Ocular Toxicity of Antibody-Drug Conjugates.

    Science.gov (United States)

    Zhao, Hui; Atkinson, John; Gulesserian, Sara; Zeng, Zhilan; Nater, Jenny; Ou, Jimmy W; Yang, Peng; Morrison, Karen; Coleman, Jeffrey; Malik, Faisal; Challita-Eid, Pia M; Karki, Sher; Aviña, Hector; Hubert, René S; Capo, Linnette; Snyder, Josh; Moon, Sung-Ju; Luethy, Roland; Mendelsohn, Brian A; Stover, David R; Doñate, Fernando

    2018-01-30

    AGS-16C3F is an antibody-drug conjugate (ADC) against ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3) containing the mcMMAF linker-payload currently in development for treatment of metastatic renal cell carcinoma. AGS-16C3F and other ADC have been reported to cause ocular toxicity in patients by unknown mechanisms. To investigate this toxicity, we developed an in vitro assay using human corneal epithelial cells (HCEC) and show that HCEC internalized AGS-16C3F and other ADCs by macropinocytosis, causing inhibition of cell proliferation. We observed the same mechanism for target-independent internalization of AGS-16C3F in fibroblasts and human umbilical vein endothelial cells (HUVEC). Macropinocytosis-mediated intake of macromolecules is facilitated by the presence of positive charges or hydrophobic residues on the surface of the macromolecule. Modification of AGS-16C3F, either by attachment of poly-glutamate peptides, mutation of residue K16 to D on AGS-16C3F (AGS-16C3F(K16D)), or decreasing the overall hydrophobicity via attachment of polyethylene glycol moieties, significantly reduced cytotoxicity against HCEC and other primary cells. Rabbits treated with AGS-16C3F showed significant ocular toxicity, whereas those treated with AGS-16C3F(K16D) presented with less severe and delayed toxicities. Both molecules displayed similar anti-tumor activity in a mouse xenograft model. These findings establish a mechanism of action for target-independent toxicities of AGS-16C3F and ADCs in general, and provide methods to ameliorate these toxicities. Copyright ©2018, American Association for Cancer Research.

  10. Antibody persistence following meningococcal C conjugate vaccination in children and adolescents infected with human immunodeficiency virus.

    Science.gov (United States)

    Frota, Ana Cristina Cisne; Harrison, Lee H; Ferreira, Bianca; Menna-Barreto, Daniela; Castro, Raquel Bernardo Nana de; Silva, Giselle Pereira da; Oliveira, Ricardo Hugo de; Abreu, Thalita F; Milagres, Lucimar G; Hofer, Cristina B

    HIV-infected individuals (HIVI) are threatened by meningococcal infection and presented lower response to vaccines. Data are scarce on long-term persistence of human serum bactericidal antibody (hSBA) after a meningococcal C conjugate (MCC) vaccine in HIVI youth; the authors aimed to describe this persistence in HIVI. HIVI and HIV uninfected individuals (HIVU), aged 2-18 years, CD4 >15% were recruited. Seroprotection (hSBA ≥1:4) at baseline and at 12-18 months after immunization was evaluated and the association of the different factors with the long-term persistence was calculated using logistic regression. A total of 145 HIVI, 50 HIVU were recruited and immunized, and their median age was 11 years (median age in HIVI group was 12 years, and 10 years in HIVU group, p-value=0.02). 85 HIVI (44%) had undetectable viral load (UVL). Seroprotection rate was 27.2%: 24.1% in HIVI and 36% in HIVU 12-18 months after immunization (p=0.14). Baseline immunity (odds ratio [OR]=70.70, 95% CI: 65.2-766.6); UVL at entry (OR: 2.87, 95% CI: 0.96-8.62) and lower family income (OR: 0.09, 95% CI: 0.01-0.69) were associated with seroprotection among HIVI. Seroprotection at 12-18 months after single dose of MCC was low for both groups, and higher among individuals who presented baseline immunity. Among HIVI, vaccine should be administered after UVL is achieved. Copyright © 2017. Published by Elsevier Editora Ltda.

  11. Characterization of the antibody response to a Haemophilus influenzae type b conjugate vaccine in children with recurrent lower respiratory tract infection

    DEFF Research Database (Denmark)

    Kristensen, K; Barington, T; Pressler, T

    1995-01-01

    once with a Haemophilus influenzae type b (Hib) conjugate vaccine. Total IgG subclasses, total antipolysaccharide Hib antibodies, and antipolysaccharide Hib antibodies of IgM, IgG, IgA, and IgG1-4 specificity were determined by ELISA. There were no significant differences between the two groups in any...

  12. Pharmacokinetics and pharmacodynamics of DSTA4637A: A novel THIOMAB™ antibody antibiotic conjugate against Staphylococcus aureus in mice.

    Science.gov (United States)

    Zhou, Chenguang; Lehar, Sophie; Gutierrez, Johnny; Rosenberger, Carrie M; Ljumanovic, Nina; Dinoso, Jason; Koppada, Neelima; Hong, Kyu; Baruch, Amos; Carrasco-Triguero, Montserrat; Saad, Ola; Mariathasan, Sanjeev; Kamath, Amrita V

    DSTA4637A, a novel THIOMAB™ antibody antibiotic conjugate (TAC) against Staphylococcus aureus (S. aureus), is currently being investigated as a potential therapy against S. aureus infections. Structurally, TAC is composed of an anti-S. aureus antibody linked to a potent antibiotic, dmDNA31. The goal of the current study was to characterize the pharmacokinetics (PK) of TAC in mice, assess the effect of S. aureus infection on its PK, and evaluate its pharmacodynamics (PD) by measuring the bacterial load in various organs at different timepoints following TAC treatment. Plasma concentrations of 3 analytes, total antibody (TAb), antibody-conjugated dmDNA31 (ac-dmDNA31), and unconjugated dmDNA31, were measured in these studies. In non-infected mice (target antigen absent), following intravenous (IV) administration of a single dose of TAC, systemic concentration-time profiles of both TAb and ac-dmDNA31 were bi-exponential and characterized by a short distribution phase and a long elimination phase as expected for a monoclonal antibody-based therapeutic. Systemic exposures of both TAb and ac-dmDNA31 were dose proportional over the dose range tested (5 to 50 mg/kg). In a mouse model of systemic S. aureus infection (target antigen present), a single IV dose of TAC demonstrated PK behavior similar to that in the non-infected mice, and substantially reduced bacterial load in the heart, kidney, and bones on 7 and 14 d post dosing. These findings have increased our understanding of the PK and PK/PD of this novel molecule, and have shown that at efficacious dose levels the presence of S. aureus infection had minimal effect on TAC PK.

  13. Stimulation of protective antibodies against type Ia and Ib group B streptococci by a type Ia polysaccharide-tetanus toxoid conjugate vaccine.

    OpenAIRE

    Wessels, M R; Paoletti, L C; Rodewald, A K; Michon, F; DiFabio, J; Jennings, H J; Kasper, D L

    1993-01-01

    Antisera elicited by type Ia group B streptococci (GBS) contain antibodies that react with both type Ia and type Ib strains. Previous studies suggested that antibodies elicited by type Ia organisms recognized a carbohydrate antigen or epitope common to Ia and Ib strains. We now report the synthesis and immunogenicity testing of a type Ia polysaccharide-tetanus toxoid (Ia-TT) conjugate vaccine. Ia-TT elicited type Ia polysaccharide-specific immunoglobulin G antibodies in all three of the rabbi...

  14. An enzymatic deconjugation method for the analysis of small molecule active drugs on antibody-drug conjugates.

    Science.gov (United States)

    Li, Yi; Gu, Christine; Gruenhagen, Jason; Yehl, Peter; Chetwyn, Nik P; Medley, Colin D

    2016-01-01

    Antibody-drug conjugates (ADCs) are complex therapeutic agents that use the specific targeting properties of antibodies and the highly potent cytotoxicity of small molecule drugs to selectively eliminate tumor cells while limiting the toxicity to normal healthy tissues. Two critical quality attributes of ADCs are the purity and stability of the active small molecule drug linked to the ADC, but these are difficult to assess once the drug is conjugated to the antibody. In this study, we report a enzyme deconjugation approach to cleave small molecule drugs from ADCs, which allows the drugs to be subsequently characterized by reversed-phase high performance liquid chromatography. The model ADC we used in this study utilizes a valine-citrulline linker that is designed to be sensitive to endoproteases after internalization by tumor cells. We screened several proteases to determine the most effective enzyme. Among the 3 cysteine proteases evaluated, papain had the best efficiency in cleaving the small molecule drug from the model ADC. The deconjugation conditions were further optimized to achieve complete cleavage of the small molecule drug. This papain deconjugation approach demonstrated excellent specificity and precision. The purity and stability of the active drug on an ADC drug product was evaluated and the major degradation products of the active drug were identified. The papain deconjugation method was also applied to several other ADCs, with the results suggesting it could be applied generally to ADCs containing a valine-citrulline linker. Our results indicate that the papain deconjugation method is a powerful tool for characterizing the active small molecule drug conjugated to an ADC, and may be useful in ensuring the product quality, efficacy and the safety of ADCs.

  15. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor, E-mail: manzoork@aims.amrita.edu, E-mail: ullasmony@aims.amrita.edu [Amrita Centre for Nanoscience and Molecular Medicine, Amrita Institute of Medical Science, Cochin 682 041 (India)

    2011-07-15

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with {approx} 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of {approx} 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in {approx} 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of {approx} 12 nm retained bright fluorescence over an extended duration of {approx} a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of {approx} 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of {approx} 8.2% in human peripheral blood cells (PBMCs) which are CD33{sup low}. The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  16. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    Science.gov (United States)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor

    2011-07-01

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with ~ 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of ~ 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in ~ 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of ~ 12 nm retained bright fluorescence over an extended duration of ~ a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of ~ 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of ~ 8.2% in human peripheral blood cells (PBMCs) which are CD33low. The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  17. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    International Nuclear Information System (INIS)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor

    2011-01-01

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with ∼ 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of ∼ 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in ∼ 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of ∼ 12 nm retained bright fluorescence over an extended duration of ∼ a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of ∼ 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of ∼ 8.2% in human peripheral blood cells (PBMCs) which are CD33 low . The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  18. High resolution separations of charge variants and disulfide isomers of monoclonal antibodies and antibody drug conjugates using ultra-high voltage capillary electrophoresis with high electric field strength.

    Science.gov (United States)

    Henley, W Hampton; He, Yan; Mellors, J Scott; Batz, Nicholas G; Ramsey, J Michael; Jorgenson, James W

    2017-11-10

    Ultra-high voltage capillary electrophoresis with high electric field strength has been applied to the separation of the charge variants, drug conjugates, and disulfide isomers of monoclonal antibodies. Samples composed of many closely related species are difficult to resolve and quantify using traditional analytical instrumentation. High performance instrumentation can often save considerable time and effort otherwise spent on extensive method development. Ideally, the resolution obtained for a given CE buffer system scales with the square root of the applied voltage. Currently available commercial CE instrumentation is limited to an applied voltage of approximately 30kV and a maximum electric field strength of 1kV/cm due to design limitations. The instrumentation described here is capable of safely applying potentials of at least 120kV with electric field strengths over 2000V/cm, potentially doubling the resolution of the best conventional CE buffer/capillary systems while decreasing analysis time in some applications. Separations of these complex mixtures using this new instrumentation demonstrate the potential of ultra-high voltage CE to identify the presence of previously unresolved components and to reduce analysis time for complex mixtures of antibody variants and drug conjugates. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Indication of viruses and virus-specific antibodies by ELISA using conjugates based on β-lactamase obtained by genetic engineering

    International Nuclear Information System (INIS)

    Kharitonenkov, I.G.; Kordym, V.A.; Khristova, M.L.; Leonov, S.V.; Kirillova, V.S.; Chernykh, S.I.

    1987-01-01

    The method of enzyme-linked immunosorbent assay (ELISA), by means of which antigens and antibodies of different origin can be detected with high sensitivity and specificity, is an immunoenzymatic technique based on the use of conjugates, or macromolecular complexes formed by covalent attachment of enzyme molecules to antigen or antibody molecules. Conjugates based on peroxidase, alkaline phosphatase, and beta-galactosidase are most frequently used to construct immunoenzymatic test systems. The use of these enzymes in ELISA, however, is complicated by the fact that they are often present in free or bound form in the biological material under study, and that their substrates either possess low stability, are difficult to synthesize, or are toxic. In this paper, in order to avoid these shortcomings, the authors develop a method for the biosynthesis of lactamase conjugates which is based on genetic engineering, and demonstrate the viability and stability of these conjugates in radioimmunoenzymatic assay of viruses

  20. Production of anti-fullerene C{sub 60} polyclonal antibodies and study of their interaction with a conjugated form of fullerene

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, O. D., E-mail: odhendrick@gmail.com; Fedyunina, N. S. [Russian Academy of Sciences, Institute of Biochemistry (Russian Federation); Martianov, A. A. [Moscow State University (Russian Federation); Zherdev, A. V.; Dzantiev, B. B. [Russian Academy of Sciences, Institute of Biochemistry (Russian Federation)

    2011-09-15

    The aim of this study was to produce anti-fullerene C{sub 60} antibodies for the development of detection systems for fullerene C{sub 60} derivatives. To produce anti-fullerene C{sub 60} antibodies, conjugates of the fullerene C{sub 60} carboxylic derivative with thyroglobulin, soybean trypsin inhibitor, and bovine serum albumin were synthesized by carbodiimide activation and characterized. Immunization of rabbits by the conjugates led to the production of polyclonal anti-fullerene antibodies. The specificity of the immune response to fullerene was investigated. Indirect competitive immunoenzyme assay was developed for the determination of conjugated fullerene with detection limits of 0.04 ng/mL (calculated for coupled C{sub 60}) and 0.4 ng/mL (accordingly to total fullerene-protein concentration).

  1. Antibody-drug conjugate bioanalysis using LB-LC-MS/MS hybrid assays: strategies, methodology and correlation to ligand-binding assays.

    Science.gov (United States)

    Wang, Jian; Gu, Huidong; Liu, Ang; Kozhich, Alexander; Rangan, Vangipuram; Myler, Heather; Luo, Linlin; Wong, Richard; Sun, Huadong; Wang, Bonnie; Vezina, Heather E; Deshpande, Shrikant; Zhang, Yan; Yang, Zheng; Olah, Timothy V; Aubry, Anne-Francoise; Arnold, Mark E; Pillutla, Renuka; DeSilva, Binodh

    2016-07-01

    Antibody-drug conjugates (ADCs) are complex drug constructs with multiple species in the heterogeneous mixture that contribute to their efficacy and toxicity. The bioanalysis of ADCs involves multiple assays and analytical platforms. A series of ligand binding and LC-MS/MS (LB-LC-MS/MS) hybrid assays, through different combinations of anti-idiotype (anti-Id), anti-payload, or generic capture reagents, and cathepsin-B or trypsin enzyme digestion, were developed and evaluated for the analysis of conjugated-payload as well as for species traditionally measured by ligand-binding assays, total-antibody and conjugated-antibody. Hybrid assays are complementary or viable alternatives to ligand-binding assay for ADC bioanalysis and PK/PD modeling. The fit-for-purpose choice of analytes, assays and platforms and an integrated strategy from Discovery to Development for ADC PK and bioanalysis are recommended.

  2. Vaccination with Shigella flexneri 2a conjugate induces type 2a and cross-reactive type 6 antibodies in humans but not in mice.

    Science.gov (United States)

    Farzam, Nahid; Ramon-Saraf, Reut; Banet-Levi, Yonit; Lerner-Geva, Liat; Ashkenazi, Shai; Kubler-Kielb, Joanna; Vinogradov, Evgeny; Robbins, John B; Schneerson, Rachel

    2017-09-05

    Shigella flexneri (S. flexneri) 6 has emerged as an important cause of shigellosis. Our efficacy study of Shigella sonnei and S. flexneri 2a O-specific polysaccharide (O-SP) conjugates in 1-4year-olds had too few S. flexneri 2a cases for efficacy evaluation but surprisingly showed protection of 3-4year-olds, S. flexneri 2a-recipients, from S. flexneri 6 infection. To investigate this cross-protection antibodies to both Shigella types were investigated in all sera remaining from previous studies. Twenty to 30% of 3-44year-old humans injected with S. flexneri 2a conjugate responded with ≥4-fold increases of IgG anti type 6, p<0.00001. The specificity of these antibodies was shown by inhibition studies. S. flexneri 6 infection of 2 children induced besides S. flexneri 6, also S. flexneri 2a antibodies, at levels of S. flexneri 2a vaccinees. S. flexneri 2a antibodies induced by S. flexneri 6 conjugates could not be studied since no such conjugate was assessed in humans and mice responded almost exclusively to the O-SP of the injected conjugate, with no cross-reactive antibodies. Our results indicate induction of cross-reactive protective antibodies. The O-acetylated disaccharide shared by S. flexneri 6 and 2a O-SPs, is the likely basis for their cross-reactivity. S. flexneri 6 O-SP conjugates, alone and in combination with S. flexneri 2a, merit further investigation for broad S. flexneri protection. Published by Elsevier Ltd.

  3. Characterization of SGN-CD123A, A Potent CD123-Directed Antibody-Drug Conjugate for Acute Myeloid Leukemia.

    Science.gov (United States)

    Li, Fu; Sutherland, May Kung; Yu, Changpu; Walter, Roland B; Westendorf, Lori; Valliere-Douglass, John; Pan, Lucy; Cronkite, Ashley; Sussman, Django; Klussman, Kerry; Ulrich, Michelle; Anderson, Martha E; Stone, Ivan J; Zeng, Weiping; Jonas, Mechthild; Lewis, Timothy S; Goswami, Maitrayee; Wang, Sa A; Senter, Peter D; Law, Che-Leung; Feldman, Eric J; Benjamin, Dennis R

    2018-02-01

    Treatment choices for acute myelogenous leukemia (AML) patients resistant to conventional chemotherapies are limited and novel therapeutic agents are needed. IL3 receptor alpha (IL3Rα, or CD123) is expressed on the majority of AML blasts, and there is evidence that its expression is increased on leukemic relative to normal hematopoietic stem cells, which makes it an attractive target for antibody-based therapy. Here, we report the generation and preclinical characterization of SGN-CD123A, an antibody-drug conjugate using the pyrrolobenzodiazepine dimer (PBD) linker and a humanized CD123 antibody with engineered cysteines for site-specific conjugation. Mechanistically, SGN-CD123A induces activation of DNA damage response pathways, cell-cycle changes, and apoptosis in AML cells. In vitro , SGN-CD123A-mediated potent cytotoxicity of 11/12 CD123 + AML cell lines and 20/23 primary samples from AML patients, including those with unfavorable cytogenetic profiles or FLT3 mutations. In vivo , SGN-CD123A treatment led to AML eradication in a disseminated disease model, remission in a subcutaneous xenograft model, and significant growth delay in a multidrug resistance xenograft model. Moreover, SGN-CD123A also resulted in durable complete remission of a patient-derived xenograft AML model. When combined with a FLT3 inhibitor quizartinib, SGN-CD123A enhanced the activity of quizartinib against two FLT3-mutated xenograft models. Overall, these data demonstrate that SGN-CD123A is a potent antileukemic agent, supporting an ongoing trial to evaluate its safety and efficacy in AML patients (NCT02848248). Mol Cancer Ther; 17(2); 554-64. ©2017 AACR . ©2017 American Association for Cancer Research.

  4. Conjugation of PspA4Pro with Capsular Streptococcus pneumoniae Polysaccharide Serotype 14 Does Not Reduce the Induction of Cross-Reactive Antibodies.

    Science.gov (United States)

    da Silva, Míriam A; Converso, Thiago R; Gonçalves, Viviane M; Leite, Luciana C C; Tanizaki, Martha M; Barazzone, Giovana C

    2017-08-01

    Current pneumococcal vaccines are composed of bacterial polysaccharides as antigens, plain or conjugated to carrier proteins. While efficacious against vaccine serotypes, epidemiologic data show an increasing incidence of infections caused by nonvaccine serotypes of Streptococcus pneumoniae The use of pneumococcal surface protein A (PspA) as a carrier protein in a conjugate vaccine could help prevent serotype replacement by increasing vaccine coverage and reducing selective pressure of S. pneumoniae serotypes. PspA is present in all pneumococcal strains, is highly immunogenic, and is known to induce protective antibodies. Based on its sequence, PspA has been classified into three families and six clades. A PspA fragment derived from family 2, clade 4 (PspA4Pro), was shown to generate antibodies with a broad range of cross-reactivity, across clades and families. Here, PspA4Pro was modified and conjugated to capsular polysaccharide serotype 14 (PS14). We investigated the impact of conjugation on the immune response induced to PspA4Pro and PS14. Mice immunized with the PS14-mPspA4Pro conjugate produced higher titers of anti-PS14 antibodies than the animals that received coadministered antigens. The conjugate induced antibodies with opsonophagocytic activity against PS14-carrying strains, as well as against a panel of strains bearing PspAs from five clades (encompassing families 1 and 2) bearing a non-PS14 serotype. Furthermore, mice immunized with PS14-mPspA4Pro were protected against nasal colonization with a nonrelated S. pneumoniae strain bearing PspA from clade 1, serotype 6B. These results demonstrate that the cross-reactivity mediated by PspA4Pro is retained following conjugation, supporting the use of PspA4 as a carrier protein in order to enhance pneumococcal vaccine coverage and encourage its further investigation as a candidate in future vaccine designs. Copyright © 2017 American Society for Microbiology.

  5. Site-Selective Orientated Immobilization of Antibodies and Conjugates for Immunodiagnostics Development

    Science.gov (United States)

    Rusling, James

    2016-01-01

    Immobilized antibody systems are the key to develop efficient diagnostics and separations tools. In the last decade, developments in the field of biomolecular engineering and crosslinker chemistry have greatly influenced the development of this field. With all these new approaches at our disposal, several new immobilization methods have been created to address the main challenges associated with immobilized antibodies. Few of these challenges that we have discussed in this review are mainly associated to the site-specific immobilization, appropriate orientation, and activity retention. We have discussed the effect of antibody immobilization approaches on the parameters on the performance of an immunoassay. PMID:27876681

  6. Amperometric Immunosensor for Carbofuran Detection Based on MWCNTs/GS-PEI-Au and AuNPs-Antibody Conjugate

    Directory of Open Access Journals (Sweden)

    Xiangyou Wang

    2013-04-01

    Full Text Available In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au nanocomposites were modified onto the surface of a glass carbon electrode (GCE via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD, ultraviolet and visible absorption spectroscopy (UV-vis and scanning electron microscopy (SEM, respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3. The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication.

  7. Antibody-conjugated gold nanoparticle-based immunosensor for ultra-sensitive detection of troponin-T.

    Science.gov (United States)

    Jacobs, Michael; Panneer Selvam, Anjan; Craven, Jon Engel; Prasad, Shalini

    2014-12-01

    The technology presented in this study demonstrates the feasibility of integrating nanostructures onto the surface of an electrical platform to achieve enhanced detection of the cardiac biomarker, troponin-T. A polymer microcontact printing technique was modified using printed circuit boards as molds for the application of gold nanoparticles onto microelectrode-patterned glass substrates. The microelectrodes were designed to support electrical impedance spectroscopy measurements and fabricated using standard photolithography methods. Capture antibodies specific to troponin-T were functionalized onto the surface of gold nanoparticles by using a thiol-based cross-linking molecule. The antibody-conjugated gold nanoparticles were stamped onto the electrodes using a matching pattern imprinted onto an elastomeric mold. As a control to validate the efficacy of the nanotextured surface on the glass substrate, an electroplated printed circuit board was also used. The incorporation of gold nanoparticles showed significant amplification of the electro-ionic signals generated through binding of the antigen to its capture antibody. Enhanced sensitivity was demonstrated through detection of the target biomarker in the femtogram per milliliter range in buffer solution and biological media. In the absence of gold nanoparticles, the sensor demonstrated detection of troponin-T at higher concentration points. This study illustrates a robust method for developing a more sensitive, label-free biosensor. © 2014 Society for Laboratory Automation and Screening.

  8. Statistical modeling of the drug load distribution on trastuzumab emtansine (Kadcyla), a lysine-linked antibody drug conjugate.

    Science.gov (United States)

    Kim, Michael T; Chen, Yan; Marhoul, Joseph; Jacobson, Fred

    2014-07-16

    Trastuzumab emtansine (Kadcyla) is a recently approved antibody-drug conjugate produced by attachment of the anti-tubulin drug, DM1, to lysine amines via the SMCC linker. The resulting product exhibits a drug load distribution from 0 to 8 drugs per antibody that can be quantified using mass spectrometry. Different statistical models were tested against the experimental data derived from samples produced during process characterization studies to determine best fit. The Poisson distribution gives the best correlation for samples manufactured using the target process conditions (yielding the target average drug to antibody ratio (DAR) of 3.5) as well as those produced under conditions that exceed the allowed manufacturing ranges and yield products with average DAR values that are significantly different from the target (i.e., ≤3.0 or ≥4.0). The Poisson distribution establishes a link between average DAR values and drug load distributions, implying that measurement and control of the former (i.e., via a simple UV spectrophotometric method) could be used to indirectly control the latter in trastuzumab emtansine.

  9. 77 FR 9678 - Prospective Grant of Exclusive License: Photosensitizing Antibody-Fluorophore Conjugates for...

    Science.gov (United States)

    2012-02-17

    ... photoimmunotherapy (PIT). The therapeutic agent is a targeted photosensitizer composed of a tumor specific antibody... photosensitizer. The prospective exclusive evaluation option license will comply with the terms and conditions of...

  10. Association of serum bactericidal antibody and opsonic antibody levels after Neisseria meningitidis serogroup C conjugate vaccine in Brazilian children and adolescents infected or not infected with HIV.

    Science.gov (United States)

    Pereira-Manfro, Wânia F; Alvino, Raquel M; Cruz, Aline C; Silva, Giselle P; Castro, Raquel B N; Ferreira, Bianca; Barreto, Daniella M; Frota, Ana Cristina C; Hofer, Cristina B; Milagres, Lucimar G

    2016-12-07

    Neisseria meningitidis serogroup C (MenC) is the main causative agent of meningitis in Brazil. HIV infection affects the quality of the immune system. HIV + children have an increased risk of infection to encapsulated bacteria such as N. meningitidis. We evaluated the opsonic antibody (OPA) levels and its correlation with serum bactericidal antibody (SBA) levels induced by one and two doses of a MenC conjugate vaccine in children and adolescents HIV + and HIV-exposed but uninfected children (HEU) group. Overall the data show the importance of two doses of vaccine for HIV + individuals. About 79% and 58% of HIV + patients showed SBA and OPA positive response after two doses of vaccine, respectively. For HEU group, 62% and 41% of patients showed SBA and OPA positive response after one dose of vaccine, respectively. A positive and significant association between SBA and OPA levels was seen after two doses of vaccine in HIV + patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Development of an immunochromatographic strip incorporating anti-mitragynine monoclonal antibody conjugated to colloidal gold for kratom alkaloids detection.

    Science.gov (United States)

    Limsuwanchote, Supattra; Putalun, Waraporn; Tanaka, Hiroyuki; Morimoto, Satoshi; Keawpradub, Niwat; Wungsintaweekul, Juraithip

    2017-12-29

    A lateral flow-based immunochromatographic strip was developed for the rapid detection of mitragynine (MG), a dominant alkaloid found in the leaves of kratom. Monoclonal antibody (mAb) against MG (anti-MG mAb) was conjugated to colloidal gold and used as a recognition probe. MG-ovalbumin conjugate (MG-OVA) and goat anti-mouse IgG were immobilized on the strip to produce a test zone and control zone, respectively. Based on the principle of a competitive assay, MG in a test sample competed with MG-OVA resident in the test zone to bind with colloidal gold-anti-MG mAb, resulting in an inverse relation of color intensity at the test zone and MG amount. The limit of detection (LOD) of the immunochromatographic strip is determined at 1 mg/mL of MG by visual assessment and 0.60 mg/mL by Image J analysis. The developed immunochromatographic strip can determine MG in kratom cocktails and kratom leaf samples. It could serve as a rapid and simple diagnostic kit for the detection of MG in kratom samples. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity

    NARCIS (Netherlands)

    Kreutz, M.; Giquel, B.; Hu, Q.; Abuknesha, R.; Uematsu, S.; Akira, S.; Nestle, F.O.; Diebold, S.S.

    2012-01-01

    Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is

  13. Production of soluble and active microbial transglutaminase in Escherichia coli for site‐specific antibody drug conjugation

    Science.gov (United States)

    Lui, Victor; Melton‐Witt, Jody; Farias, Santiago Esteban; Foletti, Davide; Shelton, David; Pons, Jaume; Rajpal, Arvind

    2015-01-01

    Abstract Applications of microbial transglutaminase (mTGase) produced from Streptomyces mobarensis (S. mobarensis) were recently extended from food to pharmaceutical industry. To use mTGase for clinical applications, like generation of site specific antibody drug conjugates, it would be beneficial to manufacture mTGase in Escherichia coli (E. coli). To date, attempts to express recombinant soluble and active S. mobarensis mTGase have been largely unsuccessful. mTGase from S. mobarensis is naturally expressed as proenzyme and stepwise proteolytically processed into its active mature form outside of the bacterial cell. The pro‐domain is essential for correct folding of mTGase as well as for inhibiting activity of mTGase inside the cell. Here, we report a genetically modified mTGase that has full activity and can be expressed at high yields in the cytoplasm of E. coli. To achieve this we performed an alanine‐scan of the mTGase pro‐domain and identified mutants that maintain its chaperone function but destabilize the cleaved pro‐domain/mTGase interaction in a temperature dependent fashion. This allows proper folding of mTGase and keeps the enzyme inactive during expression at 20°C, but results in full activity when shifted to 37°C due to loosen domain interactions. The insertion of the 3C protease cleavage site together with pro‐domain alanine mutants Tyr14, Ile24, or Asn25 facilitate high yields (30–75 mg/L), and produced an enzyme with activity identical to wild type mTGase from S. mobarensis. Site‐specific antibody drug conjugates made with the E .coli produced mTGase demonstrated identical potency in an in vitro cell assay to those made with mTGase from S. mobarensis. PMID:26481561

  14. Production of soluble and active microbial transglutaminase in Escherichia coli for site-specific antibody drug conjugation.

    Science.gov (United States)

    Rickert, Mathias; Strop, Pavel; Lui, Victor; Melton-Witt, Jody; Farias, Santiago Esteban; Foletti, Davide; Shelton, David; Pons, Jaume; Rajpal, Arvind

    2016-02-01

    Applications of microbial transglutaminase (mTGase) produced from Streptomyces mobarensis (S. mobarensis) were recently extended from food to pharmaceutical industry. To use mTGase for clinical applications, like generation of site specific antibody drug conjugates, it would be beneficial to manufacture mTGase in Escherichia coli (E. coli). To date, attempts to express recombinant soluble and active S. mobarensis mTGase have been largely unsuccessful. mTGase from S. mobarensis is naturally expressed as proenzyme and stepwise proteolytically processed into its active mature form outside of the bacterial cell. The pro-domain is essential for correct folding of mTGase as well as for inhibiting activity of mTGase inside the cell. Here, we report a genetically modified mTGase that has full activity and can be expressed at high yields in the cytoplasm of E. coli. To achieve this we performed an alanine-scan of the mTGase pro-domain and identified mutants that maintain its chaperone function but destabilize the cleaved pro-domain/mTGase interaction in a temperature dependent fashion. This allows proper folding of mTGase and keeps the enzyme inactive during expression at 20°C, but results in full activity when shifted to 37°C due to loosen domain interactions. The insertion of the 3C protease cleavage site together with pro-domain alanine mutants Tyr14, Ile24, or Asn25 facilitate high yields (30-75 mg/L), and produced an enzyme with activity identical to wild type mTGase from S. mobarensis. Site-specific antibody drug conjugates made with the E .coli produced mTGase demonstrated identical potency in an in vitro cell assay to those made with mTGase from S. mobarensis. © 2015 The Protein Society.

  15. Site-specific antibody-liposome conjugation through copper-free click chemistry: a molecular biology approach for targeted photodynamic therapy (Conference Presentation)

    Science.gov (United States)

    Obaid, Girgis; Wang, Yucheng; Kuriakose, Jerrin; Broekgaarden, Mans; Alkhateeb, Ahmed; Bulin, Anne-Laure; Hui, James; Tsourkas, Andrew; Hasan, Tayyaba

    2016-03-01

    Nanocarriers, such as liposomes, have the ability to potentiate photodynamic therapy (PDT) treatment regimens by the encapsulation of high payloads of photosensitizers and enhance their passive delivery to tumors through the enhanced permeability and retention effect. By conjugating targeting moieties to the surface of the liposomal nanoconstructs, cellular selectivity is imparted on them and PDT-based therapies can be performed with significantly higher dose tolerances, as off-target toxicity is simultaneously reduced.1 However, the maximal benefits of conventional targeted nanocarriers, including liposomes, are hindered by practical limitations including chemical instability, non-selective conjugation chemistry, poor control over ligand orientation, and loss of ligand functionality following conjugation, amongst others.2 We have developed a robust, physically and chemically stable liposomal nanoplatform containing benzoporphyrin derivative photosensitizer molecules within the phospholipid bilayer and an optimized surface density of strained cyclooctyne moieties for `click' conjugation to azido-functionalized antibodies.3 The clinical chimeric anti-EGFR antibody Cetuximab is site-specifically photocrosslinked to a recombinant bioengineered that recognizes the antibody's Fc region, containing a terminal azide.4 The copper-free click conjugation of the bioengineered Cetuximab derivative to the optimized photosensitizing liposome provides exceptional control over the antibody's optimal orientation for cellular antigen binding. Importantly, the reaction occurs rapidly under physiological conditions, bioorthogonally (selectively in the presence of other biomolecules) and without the need for toxic copper catalysis.3 Such state-of-the-art conjugation strategies push the boundaries of targeted photodynamic therapy beyond the limitations of traditional chemical coupling techniques to produce more robust and effective targeted therapeutics with applications beyond

  16. Antibody Persistence in Young Children 5 Years after Vaccination with a Combined Haemophilus influenzae Type b-Neisseria meningitidis Serogroup C Conjugate Vaccine Coadministered with Diphtheria-Tetanus-Acellular Pertussis-Based and Pneumococcal Conjugate Vaccines.

    Science.gov (United States)

    Tejedor, Juan Carlos; Brzostek, Jerzy; Konior, Ryszard; Grunert, Detlef; Kolhe, Devayani; Baine, Yaela; Van Der Wielen, Marie

    2016-07-01

    We evaluated antibody persistence in children up to 5 years after administration of a combined Haemophilus influenzae type b (Hib)-Neisseria meningitidis serogroup C (MenC)-tetanus toxoid (TT) conjugate vaccine coadministered with a pneumococcal conjugate vaccine. This is the follow-up study of a randomized trial (ClinicalTrials.gov registration no. NCT00334334/00463437) in which healthy children were vaccinated (primary vaccinations at 2, 4, and 6 months of age and booster vaccination at 11 to 18 months of age) with Hib-MenC-TT or a control MenC conjugate vaccine, coadministered with diphtheria-tetanus-acellular pertussis (DTPa)-based combination vaccines (DTPa/Hib for control groups) and a pneumococcal conjugate vaccine (10-valent pneumococcal nontypeable H. influenzae protein D conjugate vaccine [PHiD-CV] or 7-valent cross-reacting material 197 [CRM197] conjugate vaccine [7vCRM]). MenC antibody titers were measured with a serum bactericidal antibody (SBA) assay using rabbit complement (i.e., rabbit SBA [rSBA]), and antibodies against Hib polyribosylribitol phosphate (PRP) were measured with an enzyme-linked immunosorbent assay. Antibody persistence up to 5 years after booster vaccination is reported for 530 children ∼6 years of age. The percentages of children with seroprotective rSBA-MenC titers were between 24.2% and 40.1% in all groups approximately 5 years after booster vaccination. More than 98.5% of children in each group retained seroprotective anti-PRP concentrations. No vaccine-related serious adverse events and no events related to a lack of vaccine efficacy were reported. Approximately 5 years after booster vaccination, the majority of children retained seroprotective anti-PRP antibody concentrations. The percentage of children retaining seroprotective rSBA-MenC titers was low (≤40%), suggesting that a significant proportion of children may be unprotected against MenC disease. (This study has been registered at ClinicalTrials.gov under

  17. An advanced conjugation strategy for the preparation of quantum dot-antibody immunoprobes

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, V.; Čadková, M.; Datinská, Vladimíra; Klepárník, Karel; Foret, František; Bílková, Z.; Korecká, L.

    2017-01-01

    Roč. 9, č. 13 (2017), s. 1991-1997 ISSN 1759-9660 R&D Projects: GA ČR(CZ) GA17-01995S Institutional support: RVO:68081715 Keywords : quantum dots * immunoprobes * antibodies Subject RIV: CB - Analytical Chemistry , Separation OBOR OECD: Analytical chemistry Impact factor: 1.900, year: 2016

  18. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies

    DEFF Research Database (Denmark)

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-01-01

    microbeads modified with N-alkyl hydroxylamine and N-alkyl-O-methyl hydroxylamine surface groups by incubation of antigen and beads for 16 h at 40 oC without the need for coupling agents. The efficiency of the new method was evaluated by flow cytometry in model samples and serum samples containing antibodies...

  19. Antibody-targeted polymer-doxorubicin conjugates with pH-controlled activation

    Czech Academy of Sciences Publication Activity Database

    Ulbrich, Karel; Etrych, Tomáš; Chytil, Petr; Jelínková, Markéta; Říhová, Blanka

    2004-01-01

    Roč. 12, č. 8 (2004), s. 477-489 ISSN 1061-186X R&D Projects: GA ČR GA305/02/1425 Keywords : HPMA copolymers * doxorubicin * antibody Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.907, year: 2004

  20. An advanced conjugation strategy for the preparation of quantum dot-antibody immunoprobes

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, V.; Čadková, M.; Datinská, Vladimíra; Klepárník, Karel; Foret, František; Bílková, Z.; Korecká, L.

    2017-01-01

    Roč. 9, č. 13 (2017), s. 1991-1997 ISSN 1759-9660 R&D Projects: GA ČR(CZ) GA17-01995S Institutional support: RVO:68081715 Keywords : quantum dots * immunoprobes * antibodies Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 1.900, year: 2016

  1. Noble polymeric surface conjugated with zwitterionic moieties and antibodies for the isolation of exosomes from human serum.

    Science.gov (United States)

    Kim, Gahee; Yoo, Chang Eun; Kim, Myoungsoon; Kang, Hyun Ju; Park, Donghyun; Lee, Myoyong; Huh, Nam

    2012-10-17

    New zwitterionic polymer-coated immunoaffinity beads were developed to resist nonspecific protein adsorption from undiluted human serum for diagnostic applications of exosomes. A zwitterionic sulfobetaine monomer with an amine functional group was employed for simple surface chemistry and antifouling properties. An exosomal biomarker protein, epithelial cell adhesion molecule (EpCAM), was selected as a target molecule in this work. The beads were coated with polyacrylic acids (PAA) for increasing biorecognition sites, and protein G was then conjugated with carboxylic acid groups on the surfaces for controlling EpCAM antibody orientation. The remaining free carboxylic acid groups were modified with sulfobetaine moieties, and anti-EpCAM antibody was finally introduced. The amount of anti-EpCAM on the beads was increased by 40% when compared with PAA-uncoated beads. The surfaces of the beads exhibited near-net-zero charge, and nonspecific protein adsorption was effectively suppressed by sulfobetaine moieties. EpCAM was captured from undiluted human serum with almost the same degree of efficiency as from PBS buffer solution using the newly developed immunoaffinity beads.

  2. Development of a novel long-acting antidiabetic FGF21 mimetic by targeted conjugation to a scaffold antibody.

    Science.gov (United States)

    Huang, Jie; Ishino, Tetsuya; Chen, Gang; Rolzin, Paul; Osothprarop, Trina F; Retting, Kelsey; Li, Lingna; Jin, Ping; Matin, Marla J; Huyghe, Bernard; Talukdar, Saswata; Bradshaw, Curt W; Palanki, Moorthy; Violand, Bernard N; Woodnutt, Gary; Lappe, Rodney W; Ogilvie, Kathleen; Levin, Nancy

    2013-08-01

    Fibroblast growth factor (FGF)21 improves insulin sensitivity, reduces body weight, and reverses hepatic steatosis in preclinical species. We generated long-acting FGF21 mimetics by site-specific conjugation of the protein to a scaffold antibody. Linking FGF21 through the C terminus decreased bioactivity, whereas bioactivity was maintained by linkage to selected internal positions. In mice, these CovX-Bodies retain efficacy while increasing half-life up to 70-fold compared with wild-type FGF21. A preferred midlinked CovX-Body, CVX-343, demonstrated enhanced in vivo stability in preclinical species, and a single injection improved glucose tolerance for 6 days in ob/ob mice. In diet-induced obese mice, weekly doses of CVX-343 reduced body weight, blood glucose, and lipids levels. In db/db mice, CVX-343 increased glucose tolerance, pancreatic β-cell mass, and proliferation. CVX-343, created by linkage of the CovX scaffold antibody to the engineered residue A129C of FGF21 protein, demonstrated superior preclinical pharmacodynamics by extending serum half-life of FGF21 while preserving full therapeutic functionality.

  3. Tuning the Hydrolytic Stability of Next Generation Maleimide Cross-Linkers Enables Access to Albumin-Antibody Fragment Conjugates and tri-scFvs.

    Science.gov (United States)

    Forte, Nafsika; Livanos, Maria; Miranda, Enrique; Morais, Maurício; Yang, Xiaoping; Rajkumar, Vineeth S; Chester, Kerry A; Chudasama, Vijay; Baker, James R

    2018-02-21

    We describe investigations to expand the scope of next generation maleimide cross-linkers for the construction of homogeneous protein-protein conjugates. Diiodomaleimides are shown to offer the ideal properties of rapid bioconjugation with reduced hydrolysis, allowing the cross-linking of even sterically hindered systems. The optimized linkers are exploited to link human serum albumin to antibody fragments (Fab or scFv) as a prospective half-life extension platform, with retention of antigen binding and robust serum stability. Finally, a triprotein conjugate is formed, by linking scFv antibody fragments targeting carcinoembryonic antigen. This tri-scFv is shown to infer a combination of greater antigen avidity and increased in vivo half-life, representing a promising platform for antibody therapeutic development.

  4. Characterization of the antibody response to a Haemophilus influenzae type b conjugate vaccine in children with recurrent lower respiratory tract infection

    DEFF Research Database (Denmark)

    Kristensen, K; Barington, T; Pressler, T

    1995-01-01

    once with a Haemophilus influenzae type b (Hib) conjugate vaccine. Total IgG subclasses, total antipolysaccharide Hib antibodies, and antipolysaccharide Hib antibodies of IgM, IgG, IgA, and IgG1-4 specificity were determined by ELISA. There were no significant differences between the two groups in any...... single total IgG subclass, but total IgG measured as the sum of all four subclasses was significantly lower in the children with RLRI than in the controls (P = 0.036). Before vaccination, the children with RLRI had significantly less IgG antipolysaccharide Hib antibody than the controls (P = 0......M response to Hib conjugate vaccine in these children, since this isotype predominates in the primary immune response, i.e., in the absence of immunologic memory.(ABSTRACT TRUNCATED AT 250 WORDS)...

  5. Co-association of methotrexate and SPIONs into anti-CD64 antibody-conjugated PLGA nanoparticles for theranostic application.

    Science.gov (United States)

    Moura, Catarina Costa; Segundo, Marcela A; Neves, José das; Reis, Salette; Sarmento, Bruno

    2014-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease with severe consequences for the quality of life of sufferers. Regrettably, the inflammatory process involved remains unclear, and finding successful therapies as well as new means for its early diagnosis have proved to be daunting tasks. As macrophages are strongly associated with RA inflammation, effective diagnosis and therapy may encompass the ability to target these cells. In this work, a new approach for targeted therapy and imaging of RA was developed based on the use of multifunctional polymeric nanoparticles. Poly(lactic-co-glycolic acid) nanoparticles were prepared using a single emulsion-evaporation method and comprisaed the co-association of superparamagnetic iron oxide nanoparticles (SPIONs) and methotrexate. The nanoparticles were further functionalized with an antibody against the macrophage-specific receptor, CD64, which is overexpressed at sites of RA. The devised nanoparticles were characterized for mean particle size, polydispersity index, zeta potential, and morphology, as well as the association of SPIONs, methotrexate, and the anti-CD64 antibody. Lastly, the cytotoxicity of the developed nanoparticles was assessed in RAW 264.7 cells using standard MTT and LDH assays. The nanoparticles had a mean diameter in the range of 130-200 nm and zeta potential values ranging from -32 mV to -16 mV. Association with either methotrexate or SPIONs did not significantly affect the properties of the nanoparticles. Conjugation with the anti-CD64 antibody, in turn, caused a slight increase in size and surface charge. Transmission electron microscopy confirmed the association of SPIONs within the poly(lactic-co-glycolic acid) matrix. Both anti-CD64 and methotrexate association were confirmed by Fourier transform infrared spectroscopy, and quantified yielding values as high as 36% and 79%, respectively. In vitro toxicity studies confirmed the methotrexate-loaded nanosystem to be more effective than the free drug

  6. SNAP-tag technology mediates site specific conjugation of antibody fragments with a photosensitizer and improves target specific phototoxicity in tumor cells.

    Science.gov (United States)

    Hussain, Ahmad Fawzi; Kampmeier, Florian; von Felbert, Verena; Merk, Hans-F; Tur, Mehmet Kemal; Barth, Stefan

    2011-12-21

    Cancer cells can be killed by photosensitizing agents that induce toxic effects when exposed to nonhazardous light, but this also causes significant damage to surrounding healthy cells. The specificity of photodynamic therapy can be increased by conjugating photosensitizing agents to antibodies and antibody fragments that bind specifically to tumor cell antigens. However, standard conjugation reactions produce heterogeneous products whose targeting specificity and spectroscopic properties can be compromised. In this study, we used an antibody fragment (scFv-425) that binds to the epidermal growth factor receptor (EGFR) as a model to investigate the use of SNAP-tag fusions as an improved conjugation strategy. The scFv-425-SNAP-tag fusion protein allowed the specific conjugation of a chlorin e6 photosensitizer modified with O(6)-benzylguanine, generating a homogeneous product that was delivered specifically to EGFR(+) cancer cells and resulted in significant, tumor cell-specific cytotoxicity. The impact of our results on the development of photodynamic therapy is discussed.

  7. Attachment Site Cysteine Thiol pKa Is a Key Driver for Site-Dependent Stability of THIOMAB Antibody-Drug Conjugates.

    Science.gov (United States)

    Vollmar, Breanna S; Wei, Binqing; Ohri, Rachana; Zhou, Jianhui; He, Jintang; Yu, Shang-Fan; Leipold, Douglas; Cosino, Ely; Yee, Sharon; Fourie-O'Donohue, Aimee; Li, Guangmin; Phillips, Gail L; Kozak, Katherine R; Kamath, Amrita; Xu, Keyang; Lee, Genee; Lazar, Greg A; Erickson, Hans K

    2017-10-18

    The incorporation of cysteines into antibodies by mutagenesis allows for the direct conjugation of small molecules to specific sites on the antibody via disulfide bonds. The stability of the disulfide bond linkage between the small molecule and the antibody is highly dependent on the location of the engineered cysteine in either the heavy chain (HC) or the light chain (LC) of the antibody. Here, we explore the basis for this site-dependent stability. We evaluated the in vivo efficacy and pharmacokinetics of five different cysteine mutants of trastuzumab conjugated to a pyrrolobenzodiazepine (PBD) via disulfide bonds. A significant correlation was observed between disulfide stability and efficacy for the conjugates. We hypothesized that the observed site-dependent stability of the disulfide-linked conjugates could be due to differences in the attachment site cysteine thiol pK a . We measured the cysteine thiol pK a using isothermal titration calorimetry (ITC) and found that the variants with the highest thiol pK a (LC K149C and HC A140C) were found to yield the conjugates with the greatest in vivo stability. Guided by homology modeling, we identified several mutations adjacent to LC K149C that reduced the cysteine thiol pK a and, thus, decreased the in vivo stability of the disulfide-linked PBD conjugated to LC K149C. We also present results suggesting that the high thiol pK a of LC K149C is responsible for the sustained circulation stability of LC K149C TDCs utilizing a maleimide-based linker. Taken together, our results provide evidence that the site-dependent stability of cys-engineered antibody-drug conjugates may be explained by interactions between the engineered cysteine and the local protein environment that serves to modulate the side-chain thiol pK a . The influence of cysteine thiol pK a on stability and efficacy offers a new parameter for the optimization of ADCs that utilize cysteine engineering.

  8. Evaluation of a new biotin-DOTA conjugate for pretargeted antibody-guided radioimmunotherapy (PAGRIT {sup registered})

    Energy Technology Data Exchange (ETDEWEB)

    Urbano, Nicoletta; Papi, Stefano; Paganelli, Giovanni; Chinol, Marco [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Ginanneschi, Mauro [University of Florence and CNR-ICOM, Polo Scientifico, Laboratory of Peptides and Proteins, Chemistry and Biology, Sesto Fiorentino (Italy); De Santis, Rita; Pace, Silvia; Lindstedt, Ragnar; Ferrari, Liliana [Sigma Tau SpA R and D, Pomezia, Rome (Italy); Choi, Sun Ju [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2007-01-15

    A novel biotin-DOTA conjugate (r-BHD: reduced biotinamidohexylamine-DOTA) was investigated in order to provide an efficient pretargeted antibody-guided radioimmunotherapy (PAGRIT {sup registered}) application. Preclinical and clinical results are described. {sup 90}Y and {sup 177}Lu were used to label r-BHD. The effect of pH and a wide range of specific activities were studied. Radiolabelled r-BHD was tested for affinity towards avidin and for stability in saline or in human serum with and without ascorbic acid. Pharmacokinetic data were collected and organ biodistribution evaluated in a tumour-bearing pretargeted animal model. A pilot study was performed in a metastatic melanoma patient and dosimetry was estimated. High radiochemical purity (>99%) was routinely achieved with {sup 90}Y or {sup 177}Lu in sodium acetate buffer (1.0 M, pH 5.0) at a specific activity of 2.6 MBq/nmol. Both {sup 90}Y- and {sup 177}Lu-r-BHD were also prepared at higher specific activities. Radiolabelled r-BHD was stable up to 96 h in human serum and saline with the addition of ascorbic acid. The structural modifications proposed for the r-BHD stabilised it against enzymatic degradation while retaining high binding affinity for avidin. Renal clearance appeared to be the main route of excretion in animals, and high tumour uptake was observed in the pretargeted animals. The patient study showed a total body clearance of {proportional_to}85% in 24 h, with a kidney absorbed dose of 1.5 mGy/MBq. Tumour uptake was rapid and the calculated dose to a 10-mm tumour lesion was {proportional_to}12 mGy/MBq. These results indicate that the new biotin-DOTA conjugate may be a suitable candidate for pretargeting trials. (orig.)

  9. Pneumococcal Polysaccharide Abrogates Conjugate-Induced Germinal Center Reaction and Depletes Antibody Secreting Cell Pool, Causing Hyporesponsiveness

    Science.gov (United States)

    Bjarnarson, Stefania P.; Benonisson, Hreinn; Del Giudice, Giuseppe; Jonsdottir, Ingileif

    2013-01-01

    Background Plain pneumococcal polysaccharide (PPS) booster administered during second year of life has been shown to cause hyporesponsiveness. We assessed the effects of PPS booster on splenic memory B cell responses and persistence of PPS-specific long-lived plasma cells in the bone marrow (BM). Methods Neonatal mice were primed subcutanously (s.c.) or intranasally (i.n.) with pneumococcal conjugate (Pnc1-TT) and the adjuvant LT-K63, and boosted with PPS+LT-K63 or saline 1, 2 or 3 times with 16 day intervals. Seven days after each booster, spleens were removed, germinal centers (GC), IgM+, IgG+ follicles and PPS-specific antibody secreting cells (AbSC) in spleen and BM enumerated. Results PPS booster s.c., but not i.n., compromised the Pnc1-TT-induced PPS-specific Abs by abrogating the Pnc1-TT-induced GC reaction and depleting PPS-specific AbSCs in spleen and limiting their homing to the BM. There was no difference in the frequency of PPS-specific AbSCs in spleen and BM between mice that received 1, 2 or 3 PPS boosters s.c.. Repeated PPS+LT-K63 booster i.n. reduced the frequency of PPS-specific IgG+ AbSCs in BM. Conclusions PPS booster-induced hyporesponsiveness is caused by abrogation of conjugate-induced GC reaction and depletion of PPS-specific IgG+ AbSCs resulting in no homing of new PPS-specific long-lived plasma cells to the BM or survival. These results should be taken into account in design of vaccination schedules where polysaccharides are being considered. PMID:24069152

  10. Antibody persistence after serogroup C meningococcal conjugate vaccine in children with sickle cell disease.

    Science.gov (United States)

    Souza, Alessandra R; Maruyama, Claudia M; Sáfadi, Marco Aurélio P; Lopes, Marta H; Azevedo, Raymundo S; Findlow, Helen; Bai, Xilian; Borrow, Ray; Weckx, Lily Y

    2016-08-05

    A decline of protective antibody titers after MCC vaccine has been demonstrated in healthy children, this may be an issue of concern for risk groups. The aim of this study was to evaluate the persistence of bactericidal antibodies after MCC vaccine in sickle cell disease (SCD) patients. The type of vaccine used and booster response were also analyzed. SCD patients (n=141) previously immunized with MCC vaccines had blood drawn 2-8 years after the last priming dose. They were distributed according to age at primary immunization into groups: vaccination (2-3, 4-5 and 6-8). Serum bactericidal antibodies with baby rabbit complement (rSBA) and serogroup C-specific IgG concentrations were measured. The correlate of protection was rSBA titer ⩾8. Subjects with rSBA children primed under 2years of age rSBA titer ⩾8 was demonstrated in 53.3%, 21.7% and 35.0%, 2-3, 4-5, 6-8years, respectively, after vaccination, compared with 70.0%, 45.0% and 53.5%, respectively, for individuals primed at ages 2-13years. rSBA median titers and IgG median levels were higher in the older group. Six to eight years after vaccination the percentage of patients with rSBA titers ⩾8 was significantly higher in the group primed with MCC-TT (78.5%) compared with those primed with MCC-CRM197 [Menjugate® (33.3%) or Meningitec® (35.7%)] (p=0.033). After a booster, 98% achieved rSBA titer ⩾8. Immunity to meningococcal serogroup C in SCD children declines rapidly after vaccination and is dependent on the age at priming. Booster doses are needed to maintain protection in SCD patients. Persistence of antibodies seems to be longer in individuals primed with MCC-TT vaccine comparing to those immunized with MCC-CRM197. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. In vivo subcellular imaging of tumors in mouse models using a fluorophore-conjugated anti-carcinoembryonic antigen antibody in two-photon excitation microscopy.

    Science.gov (United States)

    Koga, Shigehiro; Oshima, Yusuke; Honkura, Naoki; Iimura, Tadahiro; Kameda, Kenji; Sato, Koichi; Yoshida, Motohira; Yamamoto, Yuji; Watanabe, Yuji; Hikita, Atsuhiko; Imamura, Takeshi

    2014-10-01

    Recently, there has been growing interest in applying fluorescence imaging techniques to the study of various disease processes and complex biological phenomena in vivo. To apply these methods to clinical settings, several groups have developed protocols for fluorescence imaging using antibodies against tumor markers conjugated to fluorescent substances. Although these probes have been useful in macroscopic imaging, the specificity and sensitivity of these methods must be improved to enable them to detect micro-lesions in the early phases of cancer, resulting in better treatment outcomes. To establish a sensitive and highly specific imaging method, we used a fluorophore-conjugated anti-carcinoembryonic antigen (CEA) antibody to perform macroscopic and microscopic in vivo imaging of inoculated cancer cells expressing GFP with or without CEA. Macroscopic imaging by fluorescence zoom microscopy revealed that bio-conjugation of Alexa Fluor 594 to the anti-CEA antibody allowed visualization of tumor mass consisting of CEA-expressing human cancer cells, but the background levels were unacceptably high. In contrast, microscopic imaging using a two-photon excitation microscope and the same fluorescent antibody resulted in subcellular-resolution imaging that was more specific and sensitive than conventional imaging using a fluorescence zoom microscope. These results suggest that two-photon excitation microscopy in conjunction with fluorophore-conjugated antibodies could be widely adapted to detection of cancer-specific cell-surface molecules, both in cancer research and in clinical applications. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  12. Therapeutic advantages of Auger electron- over beta-emitting radiometals or radioiodine when conjugated to internalizing antibodies.

    Science.gov (United States)

    Behr, T M; Béhé, M; Löhr, M; Sgouros, G; Angerstein, C; Wehrmann, E; Nebendahl, K; Becker, W

    2000-07-01

    Recent studies suggest a higher anti-tumour efficacy of internalizing monoclonal antibodies (MAbs) when labelled with Auger electron emitters, as compared with beta-emitters. The aim of this study was to compare the anti-tumour efficacy and toxicity of the internalizing MAb, CO17-1A, labelled with Auger electron emitters (125I, (111)In) versus conventional beta(-)-emitters (131I, 90Y) in a colon cancer model, and to assess whether the residualizing radiometals may have therapeutic advantages over the conventionally iodinated conjugates. Biodistribution studies of 125I-, (111)In- or 88Y-labelled CO17-1A were performed in nude mice bearing subcutaneous human colon cancer xenografts. For therapy, the mice were injected with either unlabelled or 125I-, 131I-, (111)In- or 90Y-labelled CO17-1A IgG2a, whereas control groups were left untreated or were given a radiolabelled isotype-matched irrelevant antibody. The influence of internalization was assessed by comparing the results with those obtained with an anti-carcinoembryonic antigen (CEA) antibody which does not internalize to a relevant extent. The maximum tolerated activities (MTA) and doses (MTD) of each agent were determined. Myelotoxicity and potential second-organ toxicities, as well as tumour growth, were monitored. Bone marrow transplantation (BMT) was performed in order to enable dose intensification. Radiometals showed significantly better tumour-to-blood ratios than the respective iodinated conjugates. The MTAs of 131I- and 125I-CO17-1A without artificial support were 11.1 MBq (300 microCi) and 111 MBq (3 mCi), respectively; the MTA of the metals was reached at 4 MBq (100 microCi) for 90Y-, and at 85 MBq (2.3 mCi) for (111)In-CO17-1A. Myelotoxicity was dose limiting in all cases. BMT enabled an increase in the MTA to 15 MBq (400 microCi) of 131I-labelled CO17-1A, to 4.4 MBq (120 microCi) of 90Y-labelled CO17-1A, and to 118 MBq (3.2 mCi) of (111)In-labelled CO17-1A, while the MTA of 125I-CO17-1A had not been

  13. Therapy of human carcinoma xenografts with antibodies to EGFr and HER-2 conjugated to radionuclides emitting low-energy electrons

    Energy Technology Data Exchange (ETDEWEB)

    Mattes, M.J.; Goldenberg, David M. [Garden State Cancer Center at the Center for Molecular Medicine and Immunology, Belleville, NJ (United States)

    2008-07-15

    Low-energy electrons (10-50 keV) can be effective and specific cytotoxic agents when delivered to the cell surface by antibodies, because their path length in tissue is comparable to a cell diameter. In this study, we have begun to evaluate the therapeutic potential of antibodies (Abs) conjugated to {sup 111}In against carcinoma xenografts in nude mice. Abs to EGFr or HER-2 were labeled with {sup 111}In to a high specific activity of approximately 1.48 GBq/mg (40 mCi/mg). They were injected into nude mice 5-6 days after inoculation of human carcinoma cells, either A431 or SK-OV-3, and tumor growth was monitored. In preliminary in vitro experiments, we calculated the cumulative decays per cell, estimated the centigray dose delivered to the nucleus, and related this to the fraction surviving. Abs to both antigens provided significant protection in nude mouse xenograft models (p values ranging from <0.05 to <0.001). Some mice appeared to be cured, but most had delayed tumor growth. The specificity of the effect was demonstrated by testing non-reactive Abs labeled in the same way. The radioactivity was required, because unconjugated Abs had no therapeutic effect. The maximum tolerated dose was required in order for therapy to be effective, but most of the treated mice had no significant weight loss or other overt signs of toxicity. Abs labeled with nuclides emitting low-energy electrons, such as {sup 111}In, can be effective therapeutic agents against microscopic s.c. tumors. This strategy should be considered for clinical applications. (orig.)

  14. Antibody conjugated glycine doped polyaniline nanofilms as efficient biosensor for atrazine

    Science.gov (United States)

    Bhardwaj, Sanjeev K.; Sharma, Amit L.; Kim, Ki-Hyun; Deep, Akash

    2017-12-01

    Atrazine is an important member of triazine family of pesticides. The development of its detection methods gained great attention due to the potential health risks associated with its contamination in various media including water, soil, and food. The contamination of atrazine in drinking water beyond the legal permissible limit of EPA (e.g. 3 ng ml-1) may cause various damages to living organisms (e.g. heart, urinary, and limb defects). In this research, we discuss the potential significance of a highly sensitive conductometric immunosensor for sensing the atrazine pesticide. To this end, electrochemical assembly of glycine doped polyaniline (PAni) nanofilms on silicon (Si) substrate was built and modified further with anti-atrazine antibodies. The herein developed immunosensor offered highly sensitive detection of atrazine with a low detection limit of 0.07 ng ml-1. The proposed biosensor was simple in design with excellent performance in terms of its sensitivity, stability and specificity. Highlights •Glycine doped PAni nanofilms have been electropolymerized on Silicon substrates. •Functionality of the above thin films provides opportunity to develop an immunosensing platform. •Highly sensitive and specific detection of atrazine has been realized over a wide concentration range with a LOD of 0.07 ng ml-1. Novelty statement Atrazine is a widely used pesticide in the agriculture sector. It is highly recommended to develop simple biosensing systems for enabling the prospect of routine monitoring. The present research for the first time proposes the design of a glycine doped PAni based simple and highly effective biosensor for the atrazine pesticide. The doping of glycine has easily generated functional groups on the nano-PAni material for further convenient immobilization of anti-atrazine antibodies. The proposed sensor can be highlighted with advantages like ease of fabrication, use of environment friendly functionalization agent, specificity, wide

  15. Use of a charge reducing agent to enable intact mass analysis of cysteine-linked antibody-drug-conjugates by native mass spectrometry

    Directory of Open Access Journals (Sweden)

    Kamila J. Pacholarz

    2016-06-01

    Full Text Available Antibody-drug-conjugates (ADC are a growing class of anticancer biopharmaceuticals. Conjugation of cysteine linked ADCs, requires initial reduction of mAb inter-chain disulfide bonds, as the drugs are attached via thiol chemistry. This results in the active mAb moiety being transformed from a covalently linked tetramer to non-covalently linked complexes, which hinders precise determination of drug load with LC–MS. Here, we show how the addition of the charge reducing agent triethylammonium acetate (TEAA preserves the intact mAb structure, is well suited to the study of cysteine linked conjugates and facilitates easy drug load determination by direct infusion native MS.

  16. DOTA-Functionalized Polylysine: A High Number of DOTA Chelates Positively Influences the Biodistribution of Enzymatic Conjugated Anti-Tumor Antibody chCE7agl.

    OpenAIRE

    Grünberg Jürgen; Jeger Simone; Sarko Dikran; Dennler Patrick; Zimmermann Kurt; Mier Walter; Schibli Roger

    2013-01-01

    Site-specific enzymatic reactions with microbial transglutaminase (mTGase) lead to a homogenous species of immunoconjugates with a defined ligand/antibody ratio. In the present study, we have investigated the influence of different numbers of 1,4,7,10-tetraazacyclododecane-N-N'-N''-N'''-tetraacetic acid (DOTA) chelats coupled to a decalysine backbone on the in vivo behavior of the chimeric monoclonal anti-L1CAM antibody chCE7agl. The enzymatic conjugation of (DOTA)1-decalysine, (DOTA)3-decaly...

  17. Antibody-conjugated gold-gold sulfide nanoparticles as multifunctional agents for imaging and therapy of breast cancer

    Directory of Open Access Journals (Sweden)

    Emily S Day

    2010-06-01

    Full Text Available Emily S Day, Lissett R Bickford, John H Slater, Nicholas S Riggall, Rebekah A Drezek, Jennifer L WestDepartment of Bioengineering, Rice University, Houston, TX, USAAbstract: The goal of this study was to develop near-infrared (NIR resonant gold-gold sulfide nanoparticles (GGS-NPs as dual contrast and therapeutic agents for cancer management via multiphoton microscopy followed by higher intensity photoablation. We demonstrate that GGS-NPs exposed to a pulsed, NIR laser exhibit two-photon induced photoluminescence that can be utilized to visualize cancerous cells in vitro. When conjugated with anti-HER2 antibodies, these nanoparticles specifically bind SK-BR-3 breast carcinoma cells that overexpress the HER2 receptor, enabling the cells to be imaged via multiphoton microscopy with an incident laser power of 1 mW. Higher excitation power (50 mW could be employed to induce thermal damage to the cancerous cells, producing extensive membrane blebbing within seconds leading to cell death. GGS-NPs are ideal multifunctional agents for cancer management because they offer the ability to pinpoint precise treatment sites and perform subsequent thermal ablation in a single setting.Keywords: cancer, nanomedicine, multiphoton microscopy, photoluminescence, photothermal therapy, theranostics

  18. CD9 monoclonal antibody-conjugated PEGylated liposomes for targeted delivery of rapamycin in the treatment of cellular senescence

    Science.gov (United States)

    Thuy Nguyen, Hanh; Thapa, Raj Kumar; Shin, Beom Soo; Jeong, Jee-Heon; Kim, Jae-Ryong; Yong, Chul Soon; Kim, Jong Oh

    2017-03-01

    Premature cellular senescence refers to the state of irreversible cell cycle arrest due to DNA damage or other stresses. In this study, CD9 monoclonal antibody (CD9mAb) was successfully conjugated to the surface of PEGylated liposomes for targeted delivery of rapamycin (LR-CD9mAb) to overcome senescence of CD9 receptor-overexpressing cells. LR-CD9mAb has a small particle size (143.3 ± 2.4 nm), narrow size distribution (polydispersity index: 0.220 ± 0.036), and negative zeta potential (-14.6 ± 1.2 mV). The uptake of CD9-targeted liposomes by premature senescent human dermal fibroblasts (HDFs) was higher than that by young HDFs, as displayed by confocal microscopic images. The senescence might not be reversed by treatment with rapamycin; however, the drug promoted cell proliferation and reduced the number of cells that expressed the senescence-associated-β-galactosidase (SA-β-gal). These effects were further confirmed by cell viability, cell cycle, and Western blotting analyses. Moreover, CD9-targeted liposomes showed better anti-senescence activity, in comparison with free rapamycin or the conventional liposomal formulation, suggesting the potential application of this system in further in vivo studies.

  19. A size exclusion-reversed phase two dimensional-liquid chromatography methodology for stability and small molecule related species in antibody drug conjugates.

    Science.gov (United States)

    Li, Yi; Gu, Christine; Gruenhagen, Jason; Zhang, Kelly; Yehl, Peter; Chetwyn, Nik P; Medley, Colin D

    2015-05-08

    Antibody drug conjugates (ADCs) are complex therapeutic agents combining the specific targeting properties of antibodies and highly potent cytotoxic small molecule drugs to selectively eliminate tumor cells while limiting the toxicity to normal healthy tissues. One unique critical quality attribute of ADCs is the content of unconjugated small molecule drug present from either incomplete conjugation or degradation of the ADC. In this work, size exclusion chromatography (SEC) was coupled with reversed-phase (RP) HPLC in an online 2-dimensional chromatography format for identification and quantitation of unconjugated small molecule drugs and related small molecule impurities in ADC samples directly without sample preparation. The SEC method in the 1st dimension not only separated the small molecule impurities from the intact ADC, but also provided information about the size variants (monomer, dimer, aggregates, etc.) of the ADC. The small molecule peak from the SEC was trapped and sent to a RP-HPLC in the 2nd dimension to further separate and quantify the different small molecule impurities present in the ADC sample. This SEC-RP 2D-LC method demonstrated excellent precision (%RSDmolecule degradation products and aggregation of the conjugate were observed in the stability samples and the degradation pathways of the ADC were investigated. This 2D-LC method offers a powerful tool for ADC characterization and provides valuable information for conjugation and formulation development. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Novel antibody conjugates for enhanced tumor uptake. Final report, September 1, 1992--August 31, 1997

    International Nuclear Information System (INIS)

    Thakur, M.

    1997-01-01

    Progress in three areas of research is summarized. These are as follows: Labeling Monoclonal antibodies (MAbs) with Tc-99m and Re-186; human melanoma tumors and specific MAbs; evaluation of biological response modifiers (BRM). The techniques of labeling MAbs (IgM, IgG, F(ab') 2 or F(ab')) with Tc-99m was developed in the author's laboratory in 1989 and that with Re-186 in 1992. The techniques are in daily use in the laboratory since then and are adapted to a convenient kit formulation. The metal ions are bound at MAb sulfhydryls generated by a controlled reduction of a pair of disulfide groups. At least two types of MAbs labeled with Tc-99m by this method have been administered into patients and excellent diagnostic results have been obtained. Over the past two and a half years the author has been successfully growing human melanoma tumors in athymic Balb/c nude mice. The cell LINE, WM-9, was obtained from Dr. D Herlyn's laboratory at Wistar Institute in Philadelphia. Sufficient quantities of antihuman melanoma specific antibodies ME 31.3 (Wistar, IgG-1) and MEM-136 (Hybritech, IgG-2A) and their F(ab') 2 fragments are also available in the laboratory. The use of BRM is a rapidly evolving field. Over the past four years, the author has evaluated a number of BRMs in a quest for agents that may augment MAb tumor uptake. These included interferon-α; a pokeweed mitogen and Ukrain, an alkaloid separated from a plant Chelideonium Majis. In these preliminary studies, normal Balb/c mice were used and the BRMs were given i.p. one hour prior to the i.v. administration of tumor necrosis factor or an MAb (TNT-F(ab') 2 ) labeled with Tc-99m which served as an imaging agent. Animals were sacrificed at 1.5 hr or 4 hrs post-injection. Highlights of the work are given here in a table

  1. SGN-CD33A: a novel CD33-targeting antibody-drug conjugate using a pyrrolobenzodiazepine dimer is active in models of drug-resistant AML.

    Science.gov (United States)

    Kung Sutherland, May S; Walter, Roland B; Jeffrey, Scott C; Burke, Patrick J; Yu, Changpu; Kostner, Heather; Stone, Ivan; Ryan, Maureen C; Sussman, Django; Lyon, Robert P; Zeng, Weiping; Harrington, Kimberly H; Klussman, Kerry; Westendorf, Lori; Meyer, David; Bernstein, Irwin D; Senter, Peter D; Benjamin, Dennis R; Drachman, Jonathan G; McEarchern, Julie A

    2013-08-22

    Outcomes in acute myeloid leukemia (AML) remain unsatisfactory, and novel treatments are urgently needed. One strategy explores antibodies and their drug conjugates, particularly those targeting CD33. Emerging data with gemtuzumab ozogamicin (GO) demonstrate target validity and activity in some patients with AML, but efficacy is limited by heterogeneous drug conjugation, linker instability, and a high incidence of multidrug resistance. We describe here the development of SGN-CD33A, a humanized anti-CD33 antibody with engineered cysteines conjugated to a highly potent, synthetic DNA cross-linking pyrrolobenzodiazepine dimer via a protease-cleavable linker. The use of engineered cysteine residues at the sites of drug linker attachment results in a drug loading of approximately 2 pyrrolobenzodiazepine dimers per antibody. In preclinical testing, SGN-CD33A is more potent than GO against a panel of AML cell lines and primary AML cells in vitro and in xenotransplantation studies in mice. Unlike GO, antileukemic activity is observed with SGN-CD33A in AML models with the multidrug-resistant phenotype. Mechanistic studies indicate that the cytotoxic effects of SGN-CD33A involve DNA damage with ensuing cell cycle arrest and apoptotic cell death. Together, these data suggest that SGN-CD33A has CD33-directed antitumor activity and support clinical testing of this novel therapeutic in patients with AML.

  2. Co-association of methotrexate and SPIONs into anti-CD64 antibody-conjugated PLGA nanoparticles for theranostic application

    Directory of Open Access Journals (Sweden)

    Moura CC

    2014-10-01

    significantly affect the properties of the nanoparticles. Conjugation with the anti-CD64 antibody, in turn, caused a slight increase in size and surface charge. Transmission electron microscopy confirmed the association of SPIONs within the poly(lactic-co-glycolic acid matrix. Both anti-CD64 and methotrexate association were confirmed by Fourier transform infrared spectroscopy, and quantified yielding values as high as 36% and 79%, respectively. In vitro toxicity studies confirmed the methotrexate-loaded nanosystem to be more effective than the free drug.Conclusion: Multifunctional anti-CD64-conjugated poly(lactic-co-glycolic acid nanoparticles for the combined delivery of methotrexate and SPIONs were successfully prepared and characterized. This nanosystem has the potential to provide a new theranostic approach for the management of RA. Keywords: FcγRI, methotrexate, poly(lactic-co-glycolic acid, superparamagnetic iron oxide nanoparticles, targeted drug delivery

  3. Validation of analytical method to calculate the concentration of conjugated monoclonal antibody

    International Nuclear Information System (INIS)

    Alcarde, Lais F.; Massicano, Adriana V.F.; Oliveira, Ricardo S.; Araujo, Elaine B. de

    2013-01-01

    The objective of this study was to develop a quantitative analytical method using high performance liquid chromatography (HPLC) to determine the antibody concentration in conjunction with bifunctional chelator. Assays were performed using a high performance liquid chromatograph, and the following conditions were used: flow rate of 1 mL / min, 15 min run time, 0.2 M sodium phosphate buffer pH 7.0 as the mobile phase and column of molecular exclusion BioSep SEC S-3000 (300 x 7.8 mm, 5 μM - Phenomenex). The calibration curve was obtained with AcM diluted in 0.2 M sodium phosphate buffer pH 7.0 by serial dilution, yielding the concentrations: 400 μg/mL, 200 μg/mL, 100 μg/mL, 50 μg/mL, 25 μg/mL and 12.5 μg/mL. From the calibration curve calculated the equation of the line and with it the concentration of the immunoconjugate. To ensure the validity of the method accuracy and precision studies were conducted. The accuracy test consisted in the evaluation of 3 samples of known concentration, being this test performed with low concentrations (50 μg/mL), medium (100 μg/mL) and high (200 μg/mL). The precision test consisted of 3 consecutive measurements of one sample of known concentration, subject to the conditions set forth above for the other tests. The correlation coefficient of the standard curve was greater than 97%, the accuracy was satisfactory at low concentrations as well as accuracy. The method was validated by showing it for the accurate and precise determination of the concentration of the immunoconjugate. Furthermore, this assay was found to be extremely important, because using the correct mass of the protein, the radiochemical purity of the radioimmunoconjugate was above 95% in all studies

  4. Improved micro-distribution of antibody-photon absorber conjugates after initial near infrared photoimmunotherapy (NIR-PIT).

    Science.gov (United States)

    Nagaya, Tadanobu; Nakamura, Yuko; Sato, Kazuhide; Harada, Toshiko; Choyke, Peter L; Kobayashi, Hisataka

    2016-06-28

    Near infrared photoimmunotherapy (NIR-PIT), a targeted cancer therapy which uses an antibody-photo absorber conjugate (APC) and near infrared light exposure, dramatically improves nano-drug delivery into treated tumor beds due to enhanced vascular permeability. We investigated the micro-distribution of APCs in a variety of NIR-PIT treated tumors. Either cetuximab (cet) or trastuzumab (tra) conjugated with IR700 (cet-tra-IR700) was administered, as appropriate, to each mouse model of tumor. Tumor-bearing mice implanted with A431-GFP, MDAMB468-GFP, 3T3Her2-GFP or N87-GFP were separated into 5 groups: group 1=no treatment; group 2=cet-tra-IR700 i.v., no light exposure; group 3=cet-tra-IR700 i.v., NIR light exposure; group 4=cet-tra-IR700 i.v. and additional cet-tra-IR700 i.v. at 24h but no light exposure; group 5=cet-tra-IR700 i.v., NIR light exposure and additional cet-tra-IR700 i.v. immediately after NIR but no additional NIR light exposure. In vivo, ex vivo and microscopic fluorescence imaging was performed. Fluorescence from the surface of the tumor (s-tumor) was compared to fluorescence from deeper areas of the tumor (d-tumor). In general, there was no significant difference in the fluorescence intensity of GFP in the tumors among all groups, however the highest IR700 fluorescence intensity was consistently shown in group 5 tumors due to added APC after NIR-PIT. Fluorescence microscopy in all tumor types demonstrated that GFP relative fluorescence intensity (RFI) in s-tumor was significantly lower in group 3 and 5 (NIR-PIT groups) than in group 1, 2, and 4 (no NIR-PIT) yet there was no significant difference in d-tumor RFI among all groups. IR700 fluorescent RFI in the d-tumor was highest in group 5 (NIR-PIT+additional APC) compared to the other groups. Cell killing after NIR-PIT was primarily on the surface, however, APCs administered immediately after NIR-PIT penetrated deeper into tissue resulting in improved cell killing after a 2nd NIR-PIT session. This

  5. Gold magnetic nanoparticle conjugate-based lateral flow assay for the detection of IgM class antibodies related to TORCH infections.

    Science.gov (United States)

    Li, Xingxing; Zhang, Qinlu; Hou, Peng; Chen, Mingwei; Hui, Wenli; Vermorken, Alphons; Luo, Zhiyi; Li, Hong; Li, Qin; Cui, Yali

    2015-11-01

    In this study, a lateral flow immunochromatographic assay (LFIA) system for the detection of immunoglobulin M (IgM) antibodies, related to TORCH [(T)oxoplasmosis, (O)ther agents, (R)ubella (also known as German Measles), (C)ytomegalovirus, and (H)erpes simplex virus infections], based on gold magnetic nanoparticles, was established. Following modification with poly(methacrylic acid), the gold magnetic nanoparticles conjugated with an anti‑human IgM antibody (μ‑chain specific) to construct a probe. A lateral flow assay device was constructed based on these conjugates. IgM antibodies to four types of pathogens, notably toxoplasmosis, rubella virus, cytomegalovirus and herpes simplex virus type 2, were detected using this device. Compared with commercial colloidal gold‑based LFIA strips, our method exhibited higher sensitivity. No interference with triglycerides, hemoglobin and bilirubin occurred, and no cross‑reactivity was noted among the four pathogens. The gold magnetic nanoparticle‑LFIA strips were used to assess 41 seropositive and 121 seronegative serum samples. The sensitivity was 100% (162/162) and the specificity was 100% (162/162). This method cannot only be used for the detection of TORCH IgM-specific antibodies, but it can potentially be developed for use in the diagnosis of other acute or recently identified autoimmune diseases.

  6. Antibody Drug Conjugates Differentiate Uptake and DNA Alkylation of Pyrrolobenzodiazepines in Tumors from Organs of Xenograft Mice.

    Science.gov (United States)

    Ma, Yong; Khojasteh, S Cyrus; Hop, Cornelis E C A; Erickson, Hans K; Polson, Andrew; Pillow, Thomas H; Yu, Shang-Fan; Wang, Hong; Dragovich, Peter S; Zhang, Donglu

    2016-12-01

    Pyrrolobenzodiazepine (PBD)-dimer is a DNA minor groove alkylator, and its CD22 THIOMAB antibody drug conjugate (ADC) demonstrated, through a disulfide linker, an efficacy in tumor reduction for more than 7 weeks with minimal body weight loss in xenograft mice after a single 0.5-1 mg/kg i.v. dose. The DNA alkylation was investigated here in tumors and healthy organs of mice to understand the sustained efficacy and tolerability. The experimental procedures included the collection of tumors and organ tissues of xenograft mice treated with the ADC followed by DNA isolation/hydrolysis/quantitation and payload recovery from reversible DNA alkylation. PBD-dimer formed a considerable amount of adducts with tissue DNA, representing approximately 98% (at 24 hours), and 99% (at 96 hours) of the total PBD-dimer in tumors, and 78-89% in liver and lung tissues, suggesting highly efficient covalent binding of the released PBD-dimer to tissue DNA. The amount of PBD-DNA adducts in tumor tissues was approximately 24-fold (at 24 hours) and 70-fold (at 96 hours) greater than the corresponding amount of adducts in liver and lung tissues. In addition, the DNA alkylation levels increased 3-fold to 4-fold from 24 to 96 hours in tumors [41/10 6 base pairs (bp) at 96 hours] but remained at the same level (1/10 6 bp) in livers and lungs. These results support the typical target-mediated cumulative uptake of ADC into tumors and payload release that offers an explanation for its sustained antitumor efficacy. In addition, the low level of DNA alkylation in normal tissues is consistent with the tolerability observed in mice. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  7. Cancer Cell Targeting Using Folic Acid/Anti-HER2 Antibody Conjugated Fluorescent CdSe/CdS/ZnS-MPA and CdTe-MSA Quantum Dots.

    Science.gov (United States)

    Singh, Gurpal; Kumar, Manoj; Soni, Udit; Arora, Vikas; Bansal, Vivek; Gupta, Dikshi; Bhat, Madhusudan; Dinda, Amit K; Sapra, Sameer; Singh, Harpal

    2015-12-01

    CdSe/CdS/ZnS and CdTe quantum dots (QDs) were synthesized by successive ion layer adsorption and reaction (SILAR) technique and direct aqueous synthesis respectively using thiol stabilizers. Synthesized CdSe/CdS/ZnS and CdTe QDs stabilized with 3-mercaptopropionic acid (MPA) and mercaptosuccinic acid (MSA) were used as fluorescent labels after conjugation with folic acid (FA) and anti-HER2 antibodies. Photoluminescence quantum yield of folated CdSe/CdS/ZnS-MPA and CdTe-MSA QDs was 59% and 77% than that of non-folated hydrophilic QDs. The folate receptor-mediated delivery of folic acid-conjugated CdTe-MSA and CdSe/CdS/ZnS-MPA QDs showed higher cellular internalization as observed by confocal laser scanning microscopic studies. Folated and non-folated CdTe-MSA QDs were highly toxic and exhibited only 10% cell viability as compared to > 80% cell viability with CdSe/CdS/ZnS-MPA QDs over the concentration ranging from 3.38 to 50 pmoles. Immunohistochemistry (IHC) results of human breast cancer tissue samples showed positive results with anti-HER2 antibody conjugated CdSe/CdS/ZnS-MPA QDs with better sensitivity and specificity as compared to conventional IHC analysis using diaminobenzedene staining.

  8. Comparison of serum bactericidal and antibody titers induced by two Haemophilus influenzae type b conjugate vaccines: A phase III randomized double-blind study.

    Science.gov (United States)

    Akeda, Yukihiro; Koizumi, Yuka; Takanami, Yohei; Sumino, Shuji; Hattori, Yumi; Sugizaki, Kayoko; Mitsuya, Nodoka; Oishi, Kazunori

    2018-03-14

    Haemophilus influenzae type b (Hib) conjugate vaccines have drastically reduced disease incidence worldwide. Protection against Hib infection has relied on the serum bactericidal activity (SBA) of antibodies to the Hib capsular polysaccharide (polyribosylribitol phosphate). However, licensure usually relies on measuring induction of antibodies to PRP as a surrogate for SBA. In a phase III clinical trial we compared a PRP-conjugate vaccine using the nontoxic diphtheria toxin mutant, CRM 197 , as carrier protein with the licensed tetanus toxoid conjugate when administered subcutaneously as a three dose primary series in Japanese infants. As an addition to the phase III study, we have now evaluated SBA and show PRP-CRM 197 induces higher levels of SBA than PRP-T four weeks after the primary series, with a statistically significant correlation with anti-PRP titers. This data confirms the superior immunogenicity of PRP-CRM 197 compared with PRP-T assessed as SBA following a three-dose primary series by subcutaneous administration. Clinical trial registry: Registered on ClinicalTrials.gov (NCT01379846). Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Meningococcal serogroup C immunogenicity, antibody persistence and memory B-cells induced by the monovalent meningococcal serogroup C versus quadrivalent meningococcal serogroup ACWY conjugate booster vaccine : A randomized controlled trial

    NARCIS (Netherlands)

    van Ravenhorst, Mariëtte B; van der Klis, Fiona R M; van Rooijen, Debbie M; Knol, Mirjam J.; Stoof, Susanne P; Sanders, Elisabeth A M; Berbers, Guy A M

    2017-01-01

    BACKGROUND: Adolescents are considered the key transmitters of meningococci in the population. Meningococcal serogroup C (MenC) antibody levels wane rapidly after MenC conjugate vaccination in young children, leaving adolescents with low antibody levels. In this study, we compared MenC immune

  10. Elimination of Tumor Cells Using Folate Receptor Targeting by Antibody-Conjugated, Gold-Coated Magnetite Nanoparticles in a Murine Breast Cancer Model

    Directory of Open Access Journals (Sweden)

    Evan S. Krystofiak

    2012-01-01

    Full Text Available Background. The chemotherapeutic treatment of cancer suffers from poor specificity for targeting the tumor cells and often results in adverse effects such as systemic toxicity, damage to nontarget tissues, and development of drug-resistant tumors in patients. Increasingly, drug nanocarriers have been explored as a way of lessening or overcoming these problems. In this study, antibody-conjugated Au-coated magnetite nanoparticles, in conjunction with inductive heating produced by exposure to an oscillating magnetic field (OMF, were evaluated for their effects on the viability of tumor cells in a murine model of breast cancer. Treatment effects were evaluated by light microscopy and SEM. Results. 4T1 mammary epithelial carcinoma cells overexpressing the folate receptor were targeted with an anti-folate receptor primary antibody, followed by labeling with secondary antibody-conjugated Au-coated magnetite nanoparticles. In the absence of OMF exposure, nanoparticle labeling had no effect on 4T1 cell viability. However, following OMF treatment, many of the labeled 4T1 cells showed extensive membrane damage by SEM analysis, and dramatically reduced viability as assessed using a live/dead staining assay. Conclusions. These results demonstrate that Au-coated magnetite targeted to tumor cells through binding to an overexpressed surface receptor, in the presence of an OMF, can lead to tumor cell death.

  11. Photoluminescence of double core/shell infrared (CdSeTe)/ZnS quantum dots conjugated to Pseudo rabies virus antibodies

    Science.gov (United States)

    Torchynska, T. V.; Casas Espinola, J. L.; Jaramillo Gómez, J. A.; Douda, J.; Gazarian, K.

    2013-06-01

    Double core CdSeTe/ZnS quantum dots (QDs) with emission at 800 nm (1.60 eV) have been studied by photoluminescence (PL) and Raman scattering methods in the non-conjugated state and after the conjugation to the Pseudo rabies virus (PRV) antibodies. The transformation of PL spectra, stimulated by the electric charge of antibodies, has been detected for the bioconjugated QDs. Raman scattering spectra are investigated with the aim to reveal the CdSeTe core compositions. The double core QD energy diagrams were designed that help to analyze the PL spectra and their transformation at the bioconjugation. It is revealed that the interface in double core QDs has the type II quantum well character that permits to explain the near IR optical transition (1.60 eV) in the double core QDs. It is shown that the essential transformation of PL spectra is useful for the study of QD bioconjugation with specific antibodies and can be a powerful technique in early medical diagnostics.

  12. Anti-PDGF receptor β antibody-conjugated squarticles loaded with minoxidil for alopecia treatment by targeting hair follicles and dermal papilla cells.

    Science.gov (United States)

    Aljuffali, Ibrahim A; Pan, Tai-Long; Sung, Calvin T; Chang, Shu-Hao; Fang, Jia-You

    2015-08-01

    This study developed lipid nanocarriers, called squarticles, conjugated with anti-platelet-derived growth factor (PDGF)-receptor β antibody to determine whether targeted Minoxidil (MXD) delivery to the follicles and dermal papilla cells (DPCs) could be achieved. Squalene and hexadecyl palmitate (HP) were used as the matrix of the squarticles. The PDGF-squarticles showed a mean diameter and zeta potential of 195 nm and -46 mV, respectively. Nanoparticle encapsulation enhanced MXD porcine skin deposition from 0.11 to 0.23 μg/mg. The antibody-conjugated nanoparticles ameliorated follicular uptake of MXD by 3-fold compared to that of the control solution in the in vivo mouse model. Both vertical and horizontal skin sections exhibited a wide distribution of nanoparticles in the follicles, epidermis, and deeper skin strata. The encapsulated MXD moderately elicited proliferation of DPCs and vascular endothelial growth factor (VEGF) expression. The active targeting of PDGF-squarticles may be advantageous to improving the limited success of alopecia therapy. Topical use of minoxidil is only one of the very few treatment options for alopecia. Nonetheless, the current delivery method is far from ideal. In this article, the authors developed lipid nanocarriers with anti-platelet-derived growth factor receptor ? antibody to target dermal papilla cells, and showed enhanced uptake of minoxidil. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Sporozoite neutralizing antibodies elicited in mice and rhesus macaques immunized with a Plasmodium falciparum repeat peptide conjugated to meningococcal outer membrane protein complex

    Directory of Open Access Journals (Sweden)

    Craig ePrzysiecki

    2012-11-01

    Full Text Available Antibodies that neutralize infectivity of malaria sporozoites target the central repeat region of the circumsporozoite (CS protein, which in Plasmodium falciparum is comprised primarily of 30-40 tandem NANP tetramer repeats. We evaluated immunogenicity of an alum-adsorbed (NANP6 peptide conjugated to an outer membrane protein complex (OMPC derived from Neisseria meningitidis, a carrier protein used in a licensed H. influenzae pediatric vaccine. Mice immunized with alum-adsorbed (NANP6-OMPC, with or without Iscomatrix© as co-adjuvant, developed high levels of anti-repeat peptide antibody that inhibited in vitro invasion of human hepatoma cells by transgenic P. berghei sporozoites that express P. falciparum CS repeats (PfPb. Inhibition of sporozoite invasion in vitro correlated with in vivo resistance to challenge by the bites of PfPb infected mosquitoes. Challenged mice had > 90% reduction of hepatic stage parasites as measured by real-time PCR, and either sterile immunity, i.e. no detectable blood stage parasites, or delayed prepatent periods which indicate neutralization of a majority, but not all, sporozoites. Rhesus macaques immunized with two doses of (NANP6-OMPC/MAA formulated with Iscomatrix© developed anti-repeat antibodies that persisted for ~2 years. A third dose of (NANP6-OMPC/MAA+ Iscomatrix© at that time elicited strong anamnestic antibody responses. Rhesus macaque immune sera obtained post second and third dose of vaccine displayed high levels of sporozoite neutralizing activity in vitro that correlated with presence of high anti-repeat antibody titers. These preclinical studies in mice of different MHC haplotypes and a non-human primate support use of CS peptide-OMPC conjugates as a highly immunogenic platform to evaluate CS protective epitopes. Potential pre-erythrocytic vaccines can be combined with sexual blood stage vaccines as a multi-antigen malaria vaccine to block invasion and transmission of Plasmodium parasites

  14. A Protein-Conjugate Approach to Develop a Monoclonal Antibody-Based Antigen Detection Test for the Diagnosis of Human Brucellosis

    Science.gov (United States)

    Patra, Kailash P.; Saito, Mayuko; Atluri, Vidya L.; Rolán, Hortensia G.; Young, Briana; Kerrinnes, Tobias; Smits, Henk; Ricaldi, Jessica N.; Gotuzzo, Eduardo; Gilman, Robert H.; Tsolis, Renee M.; Vinetz, Joseph M.

    2014-01-01

    Human brucellosis is most commonly diagnosed by serology based on agglutination of fixed Brucella abortus as antigen. Nucleic acid amplification techniques have not proven capable of reproducibly and sensitively demonstrating the presence of Brucella DNA in clinical specimens. We sought to optimize a monoclonal antibody-based assay to detect Brucella melitensis lipopolysaccharide in blood by conjugating B. melitensis LPS to keyhole limpet hemocyanin, an immunogenic protein carrier to maximize IgG affinity of monoclonal antibodies. A panel of specific of monoclonal antibodies was obtained that recognized both B. melitensis and B. abortus lipopolysaccharide epitopes. An antigen capture assay was developed that detected B. melitensis in the blood of experimentally infected mice and, in a pilot study, in naturally infected Peruvian subjects. As a proof of principle, a majority (7/10) of the patients with positive blood cultures had B. melitensis lipopolysaccharide detected in the initial blood specimen obtained. One of 10 patients with relapsed brucellosis and negative blood culture had a positive serum antigen test. No seronegative/blood culture negative patients had a positive serum antigen test. Analysis of the pair of monoclonal antibodies (2D1, 2E8) used in the capture ELISA for potential cross-reactivity in the detection of lipopolysaccharides of E. coli O157:H7 and Yersinia enterocolitica O9 showed specificity for Brucella lipopolysaccharide. This new approach to develop antigen-detection monoclonal antibodies against a T cell-independent polysaccharide antigen based on immunogenic protein conjugation may lead to the production of improved rapid point-of-care-deployable assays for the diagnosis of brucellosis and other infectious diseases. PMID:24901521

  15. A New Highly Selective and Specific Anti-puerarin polyclonal Antibody for Determination of Puerarin Using a Mannich Reaction Hapten Conjugate.

    Science.gov (United States)

    Udomsin, Orapin; Krittanai, Supaluk; Kitisripanya, Tharita; Tanaka, Hiroyuki; Putalun, Waraporn

    2018-01-01

    Puerarin (PUE) is a phytoestrogen found in Pueraria candollei and Pueraria lobata. These plants are substantial for traditional medicine in various Asian countries. PUE is a key marker that can be found only in the Pueraria species. To establish the method for determination of PUE content which is required for quality control of pharmaceutical products. PUE-cationized bovine serum albumin conjugate was created via Mannich reaction. After the rabbit immunization, the obtain anti-PUE polyclonal antibody (PAb) was used to develop an enzyme-linked immunosorbent assay (ELISA). An anti-PUE PAb possess a great sensitivity and specificity. The cross-reactivity analysis shows no cross-reaction of an established antibody against other substances. In addition, we successfully developed an indirect competitive ELISA (icELISA) for the quantitative analysis of PUE. The result of method validation conforms to acceptance criteria and correlates with high-performance liquid chromatography, the reference method. The icELISA was applied to determine PUE content in Pueraria spp. plant samples and its derived pharmaceutical products. This highly specific immunogen was created from the Mannich reaction. An icELISA can also be applied to other research propose in the further studies. The new immunogen conjugated (puerarin-cBSA) via Mannich reaction was successfully in rising of antibody against puerarin (PUE)The obtained anti-PUE polyclonal antibody (PAb) was high sensitivity and specificity to PUEAn indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed and validated using anti-PUE PAbThe established icELISA was applied to determine PUE content in various tuberous root of Pueraria sppMoreover, icELISA method can be applicable in Pueraria spp. derived products. Abbreviations used: PUE: Puerarin; PAb: Polyclonal antibody; ELISA: Enzyme-linked immunosorbent assay; icELISA: Indirect competitive ELISA; cBSA: Cationized bovine serum albumin.

  16. DOTA-functionalized polylysine: a high number of DOTA chelates positively influences the biodistribution of enzymatic conjugated anti-tumor antibody chCE7agl.

    Directory of Open Access Journals (Sweden)

    Jürgen Grünberg

    Full Text Available Site-specific enzymatic reactions with microbial transglutaminase (mTGase lead to a homogenous species of immunoconjugates with a defined ligand/antibody ratio. In the present study, we have investigated the influence of different numbers of 1,4,7,10-tetraazacyclododecane-N-N'-N''-N'''-tetraacetic acid (DOTA chelats coupled to a decalysine backbone on the in vivo behavior of the chimeric monoclonal anti-L1CAM antibody chCE7agl. The enzymatic conjugation of (DOTA1-decalysine, (DOTA3-decalysine or (DOTA5-decalysine to the antibody heavy chain (via Gln295/297 gave rise to immunoconjugates containing two, six or ten DOTA moieties respectively. Radiolabeling of the immunoconjugates with (177Lu yielded specific activities of approximately 70 MBq/mg, 400 MBq/mg and 700 MBq/mg with increasing numbers of DOTA chelates. Biodistribution experiments in SKOV3ip human ovarian cancer cell xenografts demonstrated a high and specific accumulation of radioactivity at the tumor site for all antibody derivatives with a maximal tumor accumulation of 43.6±4.3% ID/g at 24 h for chCE7agl-[(DOTA-decalysine]2, 30.6±12.0% ID/g at 24 h for chCE7agl-[(DOTA3-decalysine]2 and 49.9±3.1% ID/g at 48 h for chCE7agl-[(DOTA5-decalysine]2. The rapid elimination from the blood of chCE7agl-[(DOTA-decalysine]2 (1.0±0.1% ID/g at 24 h is associated with a high liver accumulation (23.2±4.6% ID/g at 24 h. This behavior changed depending on the numbers of DOTA moieties coupled to the decalysine peptide with a slower blood clearance (5.1±1.0 (DOTA3 versus 11.7±1.4% ID/g (DOTA5, p<0.005 at 24 h and lower radioactivity levels in the liver (21.4±3.4 (DOTA3 versus 5.8±0.7 (DOTA5, p<0.005 at 24 h. We conclude that the site-specific and stoichiometric uniform conjugation of the highly DOTA-substituted decalysine ((DOTA5-decalysine to an anti-tumor antibody leads to the formation of immunoconjugates with high specific activity and excellent in vivo behavior and is a valuable option for

  17. Characterization and cancer cell targeted imaging properties of human antivascular endothelial growth factor monoclonal antibody conjugated CdTe/ZnS quantum dots.

    Science.gov (United States)

    Pang, Lili; Xu, Jian; Shu, Chang; Guo, Jin; Ma, Xiaona; Liu, Yu; Zhong, Wenying

    2014-12-01

    High luminescence quantum yield water-soluble CdTe/ZnS core/shell quantum dots (QDs) stabilized with thioglycolic acid were synthesized. QDs were chemically coupled to fully humanized antivascular endothelial growth factor165 monoclonal antibodies to produce fluorescent probes. These probes can be used to assay the biological affinity of the antibody. The properties of QDs conjugated to an antibody were characterized by ultraviolet and visible spectrophotometry, fluorescent spectrophotometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transmission electron microscopy and fluorescence microscopy. Cell-targeted imaging was performed in human breast cancer cell lines. The cytotoxicity of bare QDs and fluorescent probes was evaluated in the MCF-7 cells with an MTT viability assay. The results proved that CdTe/ZnS QD-monoclonal antibody nanoprobes had been successfully prepared with excellent spectral properties in target detections. Surface modification by ZnS shell could mitigate the cytotoxicity of cadmium-based QDs. The therapeutic effects of antivascular endothelial growth factor antibodies towards cultured human cancer cells were confirmed by MTT assay. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Establishing in vitro-in vivo correlation for antibody drug conjugate efficacy: a PK/PD modeling approach.

    Science.gov (United States)

    Shah, Dhaval K; Loganzo, Frank; Haddish-Berhane, Nahor; Musto, Sylvia; Wald, Hallie S; Barletta, Frank; Lucas, Judy; Clark, Tracey; Hansel, Steve; Betts, Alison

    2018-04-01

    The objective of this manuscript was to establish in vitro-in vivo correlation (IVIVC) between the in vitro efficacy and in vivo efficacy of antibody drug conjugates (ADCs), using a PK/PD modeling approach. Nineteen different ADCs were used to develop IVIVC. In vitro efficacy of ADCs was evaluated using a kinetic cell cytotoxicity assay. The cytotoxicity data obtained from in vitro studies was characterized using a novel mathematical model, parameter estimates from which were used to derive an in vitro efficacy matrix for each ADC, termed as 'in vitro tumor static concentration' (TSC in vitro ). TSC in vitro is a theoretical concentration at continuous exposure of which the number of cells will neither increase nor decrease, compared to the initial cell number in the experiment. The in vivo efficacy of ADCs was evaluated using tumor growth inhibition (TGI) studies performed on human tumor xenograft bearing mice. The TGI data obtained from in vivo studies was characterized using a PK/PD model, parameter estimates from which were used to derive an in vivo efficacy matrix for each ADC, termed as 'in vivo tumor static concentration' (TSC in vivo ). TSC in vivo is a theoretical concentration if one were to maintain in the plasma of a tumor bearing mouse, the tumor volume will neither increase nor decrease compared to the initial tumor volume. Comparison of the TSC in vitro and TSC in vivo values from 19 ADCs provided a linear and positive IVIVC. The Spearman's rank correlation coefficient for TSC in vitro and TSC in vivo was found to be 0.82. On average TSC in vivo was found to be ~ 27 times higher than TSC in vitro . The reasonable IVIVC for ADCs suggests that in vitro efficacy data was correctly able to differentiate ADCs for their in vivo efficacy. Thus, IVIVC can be used as a tool to triage ADC molecules in the discovery stage, thereby preventing unnecessary scaling-up of ADCs and waste of time and resources. An ability to predict the concentration of ADC that is

  19. Inhibition of Megakaryocyte Differentiation by Antibody-Drug Conjugates (ADCs) is Mediated by Macropinocytosis: Implications for ADC-induced Thrombocytopenia.

    Science.gov (United States)

    Zhao, Hui; Gulesserian, Sara; Ganesan, Sathish Kumar; Ou, Jimmy; Morrison, Karen; Zeng, Zhilan; Robles, Veronica; Snyder, Josh; Do, Lisa; Aviña, Hector; Karki, Sher; Stover, David R; Doñate, Fernando

    2017-09-01

    Thrombocytopenia is a common adverse event in cancer patients treated with antibody-drug conjugates (ADC), including AGS-16C3F, an ADC targeting ENPP3 (ectonucleotide pyrophosphatase/phosphodiesterase-3) and trastuzumab emtansine (T-DM1). This study aims to elucidate the mechanism of action of ADC-induced thrombocytopenia. ENPP3 expression in platelets and megakaryocytes (MK) was investigated and shown to be negative. The direct effect of AGS-16C3F on platelets was evaluated using platelet rich plasma following the expression of platelet activation markers. Effects of AGS-16C3F, T-DM1, and control ADCs on maturing megakaryocytes were evaluated in an in vitro system in which human hematopoietic stem cells (HSC) were differentiated into MKs. AGS-16C3F, like T-DM1, did not affect platelets directly, but inhibited MK differentiation by the activity of Cys-mcMMAF, its active metabolite. FcγRIIA did not appear to play an important role in ADC cytotoxicity to differentiating MKs. AGS-16C3F, cytotoxic to MKs, did not bind to FcγRIIA on MKs. Blocking the interaction of T-DM1 with FcγRIIA did not prevent the inhibition of MK differentiation and IgG1-mcMMAF was not as cytotoxic to MKs despite binding to FcγRIIA. Several lines of evidence suggest that internalization of AGS-16C3F into MKs is mediated by macropinocytosis. Macropinocytosis activity of differentiating HSCs correlated with cell sensitivity to AGS-16C3F. AGS-16C3F was colocalized with a macropinocytosis marker, dextran-Texas Red in differentiating MKs. Ethyl isopropyl amiloride (EIPA), a macropinocytosis inhibitor, blocked internalization of dextran-Texas Red and AGS-16C3F. These data support the notion that inhibition of MK differentiation via macropinocytosis-mediated internalization plays a role in ADC-induced thrombocytopenia. Mol Cancer Ther; 16(9); 1877-86. ©2017 AACR See related article by Zhao et al., p. 1866 . ©2017 American Association for Cancer Research.

  20. Selective modification of NMR relaxation time in human colorectal carcinoma by using gadolinium-diethylenetriaminepentaacetic acid conjugated with monoclonal antibody 19-9.

    OpenAIRE

    Curtet, C; Tellier, C; Bohy, J; Conti, M L; Saccavini, J C; Thedrez, P; Douillard, J Y; Chatal, J F; Koprowski, H

    1986-01-01

    Monoclonal antibody 19-9 (mAb 19-9) against human colon adenocarcinoma was conjugated with gadolinium X diethylenetriaminepentaacetic acid (Gd X DTPA) and used as a contrast agent in nuclear magnetic resonance (NMR) in an effort to improve tumor target selectivity in nude mice. The data indicate that Gd X DTPA-mAb 19-9 in solution decreased the T1 relaxation of water protons at 90 MHz in direct proportion to the gadolinium concentration, and this effect was greater than in Gd X DTPA solutions...

  1. Electronic effects in emission of core/shell CdSe/ZnS quantum dots conjugated to anti-Interleukin 10 antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Quintos Vazquez, A.L. [ESIME—Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Torchynska, T.V., E-mail: ttorch@esfm.ipn.mx [ESFM–Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Casas Espinola, J.L. [ESFM–Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Jaramillo Gómez, J.A.; Douda, J. [UPIITA–Instituto Politécnico Nacional, México D. F. 07320, México (Mexico)

    2013-11-15

    The paper presents a comparative study of the photoluminescence (PL) and Raman scattering spectra of the core–shell CdSe/ZnS quantum dots (QDs) in nonconjugated states and after the conjugation to anti-Interleukin 10 antibodies (anti-IL10). All optical measurements are performed on the dried droplets of the original solution of nonconjugated and bioconjugated QDs located on the Si substrate. CdSe/ZnS QDs with emission at 605 and 655 nm have been used. PL spectra of nonconjugated QDs are characterized by one Gaussian shape PL band related to the exciton emission in the CdSe core. PL spectra of bioconjugated QDs have changed essentially: the core PL band shifts into the high energy spectral range (“blue” sift) and becomes asymmetric. Additionally two new PL bands appear. A set of physical reasons has been proposed for the “blue” shift explanation for the core PL band in bioconjugated QDs. Then Raman scattering spectra have been studied with the aim to analyze the impact of elastic strains or the oxidation process at the QD bioconjugation. The variation of PL spectra versus excitation light intensities has been studied to analyze the exciton emission via excited states in QDs. Finally the PL spectrum transformation for the core emission in bioconjugated QDs has been attributed to the electronic quantum confined effects stimulated by the electric charges of bioconjugated antibodies. -- Highlights: • The conjugation of CdSe/ZnS QDs to anti-Interleukin 10 antibodies has been studied. • PL shift to high energy is detected in bioconjugated CdSe/ZnS QDs. • The PL energy shift in bioconjugated QDs is stimulated by antibody electric charges. • The reasons of PL energy shift in bioconjugated QDs have been discussed.

  2. A cross-reacting material CRM197 conjugate vaccine induces diphtheria toxin neutralizing antibody response in children and adolescents infected or not with HIV.

    Science.gov (United States)

    Silva, Giselle P; Santos, Rafaela S; Pereira-Manfro, Wânia F; Ferreira, Bianca; Barreto, Daniella M; Frota, Ana Cristina C; Hofer, Cristina B; Milagres, Lucimar G

    2017-07-05

    Anti-diphtheria antibody levels decrease with aging, and frequent booster vaccinations are required to maintain herd immunity. We analyzed the diphtheria toxin neutralizing antibody (DT-Nab) response induced by a conjugate vaccine (meningococcal C polysaccharide-CRM 197 ) in HIV-vertically infected (HI) children and adolescents and healthy controls (HC) with matched age. We report the association of DT-Nab with the bactericidal antibodies to serogroup C meningococcus (MenC). Before vaccination, 21 HI patients (50%) had no protection against diphtheria (≤0.01IU/ml of antibody) and only 8 (19%) showed complete protection (≥0.1IU/ml). About half of the HC (56%) had complete protection before immunization and 6 subjects (12%) had no protection against diphtheria. After one and two vaccine injections, 96% of HC and 64% of HI vaccinees, respectively, showed full protection against diphtheria. These data indicate that CRM 197 was able to induce primary and/or booster response in both groups of individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Single-chain antibody conjugated to a cage amine chelator and labeled with positron-emitting copper-64 for diagnostic imaging of activated platelets.

    Science.gov (United States)

    Alt, Karen; Paterson, Brett M; Ardipradja, Katie; Schieber, Christine; Buncic, Gojko; Lim, Bock; Poniger, Stan S; Jakoby, Bjoern; Wang, Xiaowei; O'Keefe, Graeme J; Tochon-Danguy, Henri J; Scott, Andrew M; Ackermann, Uwe; Peter, Karlheinz; Donnelly, Paul S; Hagemeyer, Christoph E

    2014-08-04

    Imaging of activated platelets using an activation specific anti-GPIIb/IIIa integrin single-chain antibody (scFvanti-LIBS) conjugated to a positron emitting copper-64 complex of a cage amine sarcophagine chelator (MeCOSar) is reported. This tracer was compared in vitro to a (64)Cu(II) complex of the scFv conjugated to another commonly used macrocycle, DOTA. The scFvanti-LIBS-MeCOSar conjugate was radiolabeled with (64)Cu(II) rapidly under mild conditions and with higher specific activity than scFvanti-LIBS-DOTA. The utility of scFvanti-LIBS-MeCOSar as a diagnostic agent was assessed in vivo in a mouse model of acute thrombosis. The uptake of scFvanti-LIBS-(64)CuMeCOSar in the injured vessel was significantly higher than the noninjured vessel. Positron emission tomography (PET) was used to show accumulation of scFvanti-LIBS-(64)CuMeCOSar with high and specific uptake in the injured vessel. ScFvanti-LIBS-(64)CuMeCOSar is an excellent tool for highly sensitive in vivo detection of activated platelets in PET and has the potential to be used for early diagnosis of acute thrombotic events.

  4. The study of conjugation of anti-CD20 monoclonal antibody for labeling with metallic or lanthanides radionuclides; Estudo de conjugacao do anticorpo anti-CD20 para marcacao com radionuclideos metalicos ou lantanideos

    Energy Technology Data Exchange (ETDEWEB)

    Akanji, Akinkunmi Ganiyu

    2012-07-01

    Lymphomas are malignancies or cancers that start from the malign transformation of a lymphocyte in the lymphatic system. Generally, lymphomas start from the lymph nodes or from the agglomeration of the lymphatic tissues, organs like stomach, intestines, in some cases it can involve the bone marrow and the blood, it can also disseminate to other organs. Lymphomas are divided in two major categories: Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Patient with NHL are generally treated with radiotherapy alone or combined with immunotherapy using monoclonal antibody rituximab (MabThera Registered-Sign ). Currently, monoclonal antibodies (Acm) conjugated with bifunctional chelate agents and radiolabeled with metallic or lanthanides radionuclides are a treatment reality for patients with NHL by the principle of radioimmunotherapy (RIT). This study focused on the conditions of conjugation of Acm rituximab (MabThera Registered-Sign ) with bifunctional chelating agents DOTA and DTPA. Various parameters were studied: method of Acm purification, conditions of Acm conjugation, the method for determination of number of chelate agent coupled to the Acm, method for purification of the conjugated antibody Acm, conditions of labeling of the conjugated antibody with lutetium-177, method of purification of the radiolabeled immuno conjugate, method of radiochemical purity (RP), specific binding in vitro Raji cells (Human Burkitt) and biological distribution performed in normal Balb-c mouse. The three methodologies employed in pre-purification of Acm (dialysis, size exclusion chromatograph and dial filtration) demonstrated to be efficient; they provided sample recovery exceeding 90%. However, the methodology of dial filtration presents minimal sample loss, and gave the final recovery of the sample in micro liters; thereby facilitating sample use in subsequent experiments. Numbers of chelators attached to the Acm molecule was proportional to the molar ratio studied. When we evaluated

  5. Antibody-conjugated, dual-modal, near-infrared fluorescent iron oxide nanoparticles for antiamyloidgenic activity and specific detection of amyloid-β fibrils

    Directory of Open Access Journals (Sweden)

    Skaat H

    2013-10-01

    Full Text Available Hadas Skaat,1 Enav Corem-Slakmon,1 Igor Grinberg,1 David Last,2 David Goez,2 Yael Mardor,2,3 Shlomo Margel1 1Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan, Israel; 2Advanced Technology Center, Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel; 3Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel Abstract: Amyloid-β (Aβ peptide is the main fibrillar component of plaque deposits found in brains affected by Alzheimer's disease (AD and is related to the pathogenesis of AD. Passive anti-Aβ immunotherapy has emerged as a promising approach for the therapy of AD, based on the administration of specific anti-Aβ monoclonal antibodies (aAβmAbs to delay Aβ aggregation in the brain. However, the main disadvantage of this approach is the required readministration of the aAβmAbs at frequent intervals. There are only a few reports describing in vitro study for the immobilization of aAβmAbs to nanoparticles as potential targeting agents of Aβ aggregates. In this article, we report the immobilization of the aAβmAb clone BAM10 to near-infrared fluorescent maghemite nanoparticles for the inhibition of Aβ40 fibrillation kinetics and the specific detection of Aβ40 fibrils. The BAM10-conjugated iron oxide nanoparticles were well-characterized, including their immunogold labeling and cytotoxic effect on PC-12 (pheochromocytoma cell line. Indeed, these antibody-conjugated nanoparticles significantly inhibit the Aβ40 fibrillation kinetics compared with the same concentration, or even five times higher, of the free BAM10. This inhibitory effect was confirmed by different assays such as the photo-induced crosslinking of unmodified proteins combined with sodium dodecyl sulfate–polyacrylamide gel electrophoresis. A cell viability assay also confirmed that these antibody-conjugated nanoparticles significantly reduced the Aβ40-induced cytotoxicity to PC-12 cells. Furthermore, the selective

  6. Comparison of a chimeric anti-carcinoembryonic antigen antibody conjugated with visible or near-infrared fluorescent dyes for imaging pancreatic cancer in orthotopic nude mouse models

    Science.gov (United States)

    Maawy, Ali A.; Hiroshima, Yukihiko; Kaushal, Sharmeela; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

    2013-12-01

    The aim of this study was to evaluate a set of visible and near-infrared dyes conjugated to a tumor-specific chimeric antibody for high-resolution tumor imaging in orthotopic models of pancreatic cancer. BxPC-3 human pancreatic cancer was orthotopically implanted into pancreata of nude mice. Mice received a single intravenous injection of a chimeric anti-carcinoembryonic antigen antibody conjugated to one of the following fluorophores: 488-nm group (Alexa Fluor 488 or DyLight 488); 550-nm group (Alexa Fluor 555 or DyLight 550); 650-nm group (Alexa Fluor 660 or DyLight 650), or the 750-nm group (Alexa Fluor 750 or DyLight 755). After 24 h, the Olympus OV100 small-animal imaging system was used for noninvasive and intravital fluorescence imaging of mice. Dyes were compared with respect to depth of imaging, resolution, tumor-to-background ratio (TBR), photobleaching, and hemoglobin quenching. The longer wavelength dyes had increased depth of penetration and ability to detect the smallest tumor deposits and provided the highest TBRs, resistance to hemoglobin quenching, and specificity. The shorter wavelength dyes were more photostable. This study showed unique advantages of each dye for specific cancer imaging in a clinically relevant orthotopic model.

  7. Development of novel anti-Kv 11.1 antibody-conjugated PEG-TiO2 nanoparticles for targeting pancreatic ductal adenocarcinoma cells

    Science.gov (United States)

    Sette, Angelica; Spadavecchia, Jolanda; Landoulsi, Jessem; Casale, Sandra; Haye, Bernard; Crociani, Olivia; Arcangeli, Annarosa

    2013-12-01

    Titanium dioxide (TiO2) has been widely used in many nanotechnology areas including nanomedicine, where it could be proposed for the photodynamic and sonodynamic cancer therapies. However, TiO2 nanoformulations have been shown to be toxic for living cells. In this article, we report the development of a new delivery system, based on nontoxic TiO2 nanoparticles, further conjugated with a monoclonal antibody against a novel and easily accessible tumor marker, e.g., the Kv 11.1 potassium channel. We synthesized, by simple solvothermal method, dicarboxylic acid-terminated PEG TiO2 nanocrystals (PEG-TiO2 NPs). Anti-Kv 11.1 monoclonal antibodies (Kv 11.1-Mab) were further linked to the terminal carboxylic acid groups. Proper conjugation was confirmed by X-ray photoelectron spectroscopy analysis. Kv 11.1-Mab-PEG-TiO2 NPs efficiently recognized the specific Kv 11.1 antigen, both in vitro and in pancreatic ductal adenocarcinoma (PDAC) cells, which express the Kv 11.1 channel onto the plasma membrane. Both PEG TiO2 and Kv 11.1-Mab-PEG-TiO2 NPs were not cytotoxic, but only Kv 11.1-Mab-PEG-TiO2 NPs were efficiently internalized into PDAC cells. Data gathered from this study may have further applications for the chemical design of nanostructures to be applied for therapeutic purposes in pancreatic cancer.

  8. Binding diversity of monoclonal antibodies to alpha(2-->8) polysialic acid conjugated to outer membrane vesicle via adipic acid dihydrazide.

    Science.gov (United States)

    Devi, S J; Karpas, A B; Frasch, C E

    1996-07-01

    Murine monoclonal antibodies (mAbs) were generated using group B Neisseria meningitidis and Escherichia coli K1 polysaccharides (PSs) conjugated to outer membrane vesicle (OMV) via adipic acid dihydrazide, and were used to identify the immunodeterminants expressed on these capsular PSs. Ten mAbs representative of IgM and all subclasses of IgG were obtained which recognized diverse immunodeterminants on alpha(2-->8) polysialic acid (PSA). The specificity of mAbs to different antigenic determinants was assessed by their differential binding to PSA attached to a solid phase by different methods and confirmed by absorption studies. Two mAbs from the E. coli K1 fusion were directed to the O-acetyl epitope and the rest reacted with both the PSs only when attached to a solid phase by certain means. The methods by which PSA was coated on the solid phase had an impact on the epitope expression and binding pattern. At the concentrations used, the O-acetyl-specific mAbs, IgG1 and IgG3 mAbs were not bactericidal against group B N. meningitidis, whereas other mAbs were. The conjugates B and K1 PSs present to the murine immune system different antigenic determinants, some of which elicit bactericidal antibodies.

  9. Isolation of recombinant Hepatitis B surface antigen with antibody-conjugated superparamagnetic Fe3O4/SiO2core-shell nanoparticles.

    Science.gov (United States)

    Mostafaei, Mehdi; Hosseini, Seyed Nezamedin; Khatami, Maryam; Javidanbardan, Amin; Sepahy, Abbas Akhavan; Asadi, Ebadullah

    2018-05-01

    In the production process of recombinant Hepatitis B surface antigen (rHBsAg) various separation techniques are used to purify this virus-like particle (VLP). In this study, we developed antibody-conjugated super-paramagnetic Fe 3 O 4 /SiO 2 core-shell nanoparticles as a highly selective method for isolation of expressed rHBsAg in yeast Pichia pastoris. For this purpose, first, iron oxide magnetic nanoparticles (MNP s ) were prepared by co-precipitation method in alkali media and coated with silica. Then the surface was activated by amine groups and conjugated with oxidized antibodies. X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) were used to study the physical properties of MNPs. To evaluate the efficacy of these MNPs as a purification technique successfully synthesized MNPs were added to the rHBsAg sample to couple with the antigen and then be isolated based on their magnetic property. In the present research, in the optimum condition, we could isolate 65% of total rHBsAg from the final vaccine sample with purity above 95%. In this procedure, the maximum obtained specific yield (mg HBsAg/mg MNPs) was equal to 37.6. These results underline the potential application of the immune-magnetic separation (IMS) in the future bioseparation systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Anti-HER2 antibody and ScFvEGFR-conjugated antifouling magnetic iron oxide nanoparticles for targeting and magnetic resonance imaging of breast cancer

    Directory of Open Access Journals (Sweden)

    Chen H

    2013-10-01

    Full Text Available Hongwei Chen,1,* Liya Wang,1,2,* Qiqi Yu,1,2 Weiping Qian,3 Diana Tiwari,1 Hong Yi,4 Andrew Y Wang,5 Jing Huang,1,2 Lily Yang,3 Hui Mao1,2 1Department of Radiology and Imaging Sciences, 2Center for Systems Imaging, 3Department of Surgery, Emory University School of Medicine, 4Robert Apkarian Electron Microscopy Core, Emory University, Atlanta, GA, 5Ocean NanoTech LLC, Springdale, AK, USA *These authors contributed equally to this work Abstract: Antifouling magnetic iron oxide nanoparticles (IONPs coated with block copolymer poly(ethylene oxide-block-poly(γ-methacryloxypropyltrimethoxysilane (PEO-b-PγMPS were investigated for improving cell targeting by reducing nonspecific uptake. Conjugation of a HER2 antibody, Herceptin®, or a single chain fragment (ScFv of antibody against epidermal growth factor receptor (ScFvEGFR to PEO-b-PγMPS-coated IONPs resulted in HER2-targeted or EGFR-targeted IONPs (anti-HER2-IONPs or ScFvEGFR-IONPs. The anti-HER2-IONPs bound specifically to SK-BR-3, a HER2-overexpressing breast cancer cell line, but not to MDA-MB-231, a HER2-underexpressing cell line. On the other hand, the ScFvEGFR-IONPs showed strong reactivity with MDA-MB-231, an EGFR-positive human breast cancer cell line, but not with MDA-MB-453, an EGFR-negative human breast cancer cell line. Transmission electron microscopy revealed internalization of the receptor-targeted nanoparticles by the targeted cancer cells. In addition, both antibody-conjugated and non-antibody-conjugated IONPs showed reduced nonspecific uptake by RAW264.7 mouse macrophages in vitro. The developed IONPs showed a long blood circulation time (serum half-life 11.6 hours in mice and low accumulation in both the liver and spleen. At 24 hours after systemic administration of ScFvEGFR-IONPs into mice bearing EGFR-positive breast cancer 4T1 mouse mammary tumors, magnetic resonance imaging revealed signal reduction in the tumor as a result of the accumulation of the targeted IONPs

  11. The impact of administration of conjugate vaccines containing cross reacting material on Haemophilus influenzae type b antibody responses in infants: A systematic review and meta-analysis of randomised controlled trials.

    Science.gov (United States)

    Voysey, Merryn; Sadarangani, Manish; Clutterbuck, Elizabeth; Bolgiano, Barbara; Pollard, Andrew J

    2016-07-25

    Protein-polysaccharide conjugate vaccines such as Haemophilus influenzae type b (Hib), meningococcal, and pneumococcal vaccine, induce immunological memory and longer lasting protection than plain polysaccharide vaccines. The most common proteins used as carriers are tetanus toxoid (TT) and cross reacting material-197 (CRM), a mutant form of diphtheria toxoid. CRM conjugate vaccines have been reported to suppress antibody responses to co-administered Hib-TT vaccine. We conducted a systematic review and meta-analysis of randomised controlled trials in which infants were randomised to receive meningococcal or pneumococcal conjugate vaccines along with Hib-TT. Trials of licensed vaccines with different carrier proteins were included for group C meningococcal (MenC), quadrivalent ACWY meningococcal (MenACWY), and pneumococcal vaccines. Twenty-three trials were included in the meta-analyses. Overall, administration of MenC-CRM in a 2 or 3 dose schedule resulted in a 45% reduction in Hib antibody concentrations (GMR 0.55, 95% CI 0.49-0.62). MenACWY-CRM boosted Hib antibody responses by 22% (GMR 1.22, 95% CI 1.06-1.41) whilst pneumococcal CRM conjugate vaccines had no impact on Hib antibody responses (GMR 0.91, 95% CI 0.68-1.22). The effect of CRM protein-polysaccharide conjugate vaccines on Hib antibody responses varies greatly between vaccines. Co-administration of a CRM conjugate vaccine can produce either positive or negative effects on Hib antibody responses. These inconsistencies suggest that CRM itself may not be the main driver of variability in Hib responses, and challenge current perspectives on this issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Quantitation of antibody-secreting cells in the blood after vaccination with Haemophilus influenzae type b conjugate vaccine

    DEFF Research Database (Denmark)

    Barington, T; Heilmann, C; Andersen, V

    1990-01-01

    The human B-lymphocyte response to protein-conjugated polysaccharide antigens has not previously been studied at the cellular level. In order to do so, we developed and evaluated haemolytic plaque-forming cell assays detecting Haemophilus influenzae type b (Hib) capsular polysaccharide...... capsular polysaccharides from Hib and pneumococci. The predominance of IgA AbSC in response to both conjugate and pure polysaccharide vaccines is probably due to reactivation of the same clones of IgA-committed memory B cells originally primed at the mucosa by natural exposure to the polysaccharide...

  13. Effect of Antigen Retrieval Methods on Nonspecific Binding of Antibody-Metal Nanoparticle Conjugates on Formalin-Fixed Paraffin-Embedded Tissue.

    Science.gov (United States)

    Zhang, Yuying; Wang, Xin-Ping; Perner, Sven; Bankfalvi, Agnes; Schlücker, Sebastian

    2018-01-02

    Immunohistochemical analysis of formalin-fixed paraffin-embedded (FFPE) tissues provides important diagnostic and prognostic information in pathology. Metal nanoparticles (NPs) and, in particular, surface-enhanced Raman scattering (SERS) nanotags as a new class of labeling reagents are promising to be used for multiplexed protein profiling on tissue sections. However, nonspecific binding of NPs onto the tissue specimens greatly hampers their clinical applications. In this study, we found that the antigen retrieval method strongly influences the extent of nonspecific binding of the antibody-SERS NP conjugates to the tissue. Our SERS labels comprised ca. 70 nm Au nanostars coated with ethylene glycol-modified Raman reporter molecules for hydrophilic stabilization and subsequent covalent bioconjugation to antibodies. We systematically investigated the influence of heat- and protease-induced epitope retrieval (HIER and PIER, respectively) on the immunostaining quality of prostate-specific antigen (PSA) on human prostate tissue sections. The best staining results were obtained with PIER. Pretreatment of the tissue sections by HIER led to selective but nonspecific adsorption of the antibody-Au nanostar conjugates onto epithelial cells, while enzymatic treatment within PIER did not. In addition to gold nanostars, also other types of metal NPs with different shapes and sizes (including ca. 20 nm quasi-spherical Au NPs and ca. 60 nm quasi-spherical Au/Ag nanoshells) as well as tissue sections from different organs (including prostate and breast) were tested; in each case the same tendency was observed, i.e., PIER yielded better results than HIER. Therefore, we recommend PIER for future NP-based tissue immunostaining such as immuno-SERS microscopy. Alternatively, for antigens that can only be unmasked by heating, PEGylation of the NPs is recommended to avoid nonspecific binding.

  14. [Equilibrium and kinetic parameters of the interaction of strophanthin K and its peroxidase conjugates with soluble and immobilized specific antibodies].

    Science.gov (United States)

    Tarun, E I; Savenkova, M I; Metelitsa, D I

    1995-07-01

    Using solid phase enzyme-linked immunoassay (ELISA), rate constants for the formation and dissociation as well as equilibrium dissociation constants for strophanthin complexes interaction with specific antibodies (both soluble and immobilized on activated polystyrene beads and polyamide membranes) have been determined. A satisfactory correlation was found between dissociation constants for immune complexes determined by ELISA (both soluble and immobilized ones) and associations constants for these complexes determined by the Scatchard method. The experimental values of kinetic and equilibrium constants for strophanthin K and its peroxidase complexes interaction reflect the difference in the nature of interacting particles and their environment. Strophanthin complexes with antibodies appeared to be more stable when formed on adsorbents (in comparison with those formed in solution). Strophanthin interaction with immobilized antibodies occurred at a slower rate than that with soluble antibodies. Strophanthin reacts with antibodies more readily than its complexes both in solution and on solid matrices of various polymeric nature.

  15. Immunosuppressive drugs impairs antibody response of the polysaccharide and conjugated pneumococcal vaccines in patients with Crohn's disease

    DEFF Research Database (Denmark)

    Kantsø, Bjørn; Halkjær, Sofie Ingdam; Thomsen, Ole Østergaard

    2015-01-01

    with and without immunosuppressive treatment four weeks post vaccination. METHODS: In a randomized trial of the 23-valent pneumococcal polysaccharide vaccine (PPV23) and the 13-valent pneumococcal conjugated vaccine (PCV13), a group of CD patients treated with immunosuppressive drugs (IS) alone or in combination...

  16. Stunting correlates with high salivary and serum antibody levels after 13-valent pneumococcal conjugate vaccination of Venezuelan Amerindian children

    NARCIS (Netherlands)

    Verhagen, Lilly M; Hermsen, Meyke; Rivera-Olivero, Ismar; Sisco, María Carolina; Pinelli, Elena; Hermans, Peter W M; Berbers, Guy A M; de Waard, Jacobus H; de Jonge, Marien I

    2016-01-01

    OBJECTIVE: To determine the impact of pre-vaccination nutritional status on vaccine responses in Venezuelan Warao Amerindian children vaccinated with the 13-valent pneumococcal conjugate vaccine (PCV13) and to investigate whether saliva can be used as read-out for these vaccine responses. METHODS: A

  17. Antibody Kinetics and Response to Routine Vaccinations in Infants Born to Women Who Received an Investigational Trivalent Group B Streptococcus Polysaccharide CRM197-Conjugate Vaccine During Pregnancy.

    Science.gov (United States)

    Madhi, Shabir A; Koen, Anthonet; Cutland, Clare L; Jose, Lisa; Govender, Niresha; Wittke, Frederick; Olugbosi, Morounfolu; Sobanjo-Ter Meulen, Ajoke; Baker, Sherryl; Dull, Peter M; Narasimhan, Vas; Slobod, Karen

    2017-11-13

    Maternal vaccination against group B Streptococcus (GBS) might provide protection against invasive GBS disease in infants. We investigated the kinetics of transplacentally transferred GBS serotype-specific capsular antibodies in the infants and their immune response to diphtheria toxoid and pneumococcal vaccination. This phase 1b/2, observer-blind, single-center study (NCT01193920) enrolled infants born to women previously randomized (1:1:1:1) to receive either GBS vaccine at dosages of 0.5, 2.5, or 5.0 μg of each of 3 CRM197-glycoconjugates (serotypes Ia, Ib, and III), or placebo. Infants received routine immunization: combination diphtheria vaccine (diphtheria-tetanus-acellular pertussis-inactivated poliovirus/Haemophilus influenzae type b vaccine; age 6/10/ 14 weeks) and 13-valent pneumococcal CRM197-conjugate vaccine (PCV13; age 6/14 weeks and 9 months). Antibody levels were assessed at birth, day (D) 43, and D91 for GBS serotypes; 1 month postdose 3 (D127) for diphtheria; and 1 month postprimary (D127) and postbooster (D301) doses for pneumococcal serotypes. Of 317 infants enrolled, 295 completed the study. In infants of GBS vaccine recipients, GBS serotype-specific antibody geometric mean concentrations were significantly higher than in the placebo group at all timepoints and predictably decreased to 41%-61% and 26%-76% of birth levels by D43 and D91, respectively. Across all groups, ≥95% of infants were seroprotected against diphtheria at D127 and ≥91% of infants had seroprotective antibody levels against each PCV13 pneumococcal serotype at D301. Maternal vaccination with an investigational CRM197-glycoconjugate GBS vaccine elicited higher GBS serotype-specific antibody levels in infants until 90 days of age, compared with a placebo group, and did not affect infant immune responses to diphtheria toxoid and pneumococcal vaccination. NCT01193920. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  18. DOTA-functionalized polylysine: a high number of DOTA chelates positively influences the biodistribution of enzymatic conjugated anti-tumor antibody chCE7agl.

    Science.gov (United States)

    Grünberg, Jürgen; Jeger, Simone; Sarko, Dikran; Dennler, Patrick; Zimmermann, Kurt; Mier, Walter; Schibli, Roger

    2013-01-01

    Site-specific enzymatic reactions with microbial transglutaminase (mTGase) lead to a homogenous species of immunoconjugates with a defined ligand/antibody ratio. In the present study, we have investigated the influence of different numbers of 1,4,7,10-tetraazacyclododecane-N-N'-N''-N'''-tetraacetic acid (DOTA) chelats coupled to a decalysine backbone on the in vivo behavior of the chimeric monoclonal anti-L1CAM antibody chCE7agl. The enzymatic conjugation of (DOTA)1-decalysine, (DOTA)3-decalysine or (DOTA)5-decalysine to the antibody heavy chain (via Gln295/297) gave rise to immunoconjugates containing two, six or ten DOTA moieties respectively. Radiolabeling of the immunoconjugates with (177)Lu yielded specific activities of approximately 70 MBq/mg, 400 MBq/mg and 700 MBq/mg with increasing numbers of DOTA chelates. Biodistribution experiments in SKOV3ip human ovarian cancer cell xenografts demonstrated a high and specific accumulation of radioactivity at the tumor site for all antibody derivatives with a maximal tumor accumulation of 43.6±4.3% ID/g at 24 h for chCE7agl-[(DOTA)-decalysine]2, 30.6±12.0% ID/g at 24 h for chCE7agl-[(DOTA)3-decalysine]2 and 49.9±3.1% ID/g at 48 h for chCE7agl-[(DOTA)5-decalysine)]2. The rapid elimination from the blood of chCE7agl-[(DOTA)-decalysine]2 (1.0±0.1% ID/g at 24 h) is associated with a high liver accumulation (23.2±4.6% ID/g at 24 h). This behavior changed depending on the numbers of DOTA moieties coupled to the decalysine peptide with a slower blood clearance (5.1±1.0 (DOTA)3 versus 11.7±1.4% ID/g (DOTA)5, pactivity and excellent in vivo behavior and is a valuable option for radioimmunotherapy and potentially antibody-drug conjugates (ADCs).

  19. Preparation of gold nanoparticles by microwave heating and application of spectroscopy to study conjugate of gold nanoparticles with antibody E. coli O157:H7

    International Nuclear Information System (INIS)

    Ngo, Vo Ke Thanh; Nguyen, Hoang Phuong Uyen; Huynh, Trong Phat; Tran, Nguyen Nguyen Pham; Lam, Quang Vinh; Huynh, Thanh Dat

    2015-01-01

    Gold nanoparticles (AuNPs) of 15–20 nm size range have attracted attention for producing smart sensing devices as diagnostic tools in biomedical sciences. Citrate capped AuNPs are negatively charged, which can be exploited for electrostatic interactions with some positively charged biomolecules like antibodies. In this paper we describe a method for the low cost synthesis of gold nanoparticles using sodium citrate (Na 3 Ct) reduction in chloroauric acid (HAuCl 4 .3H 2 O) by microwave heating (diameter about 13–15 nm). Gold nanoparticles were functionalized with surface activation by 3-mercaptopropionic acid for attaching antibody. These nanoparticles were then reacted with anti-E. coli O157:H7, using N-hydroxy succinimide (NHS) and carbondimide hydrochloride (EDC) coupling chemistry. The product was characterized with UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy and zeta potential. In addition, the binding of antibody-gold nanoparticles conjugates to E. coli O157:H7 was demonstrated using transmission electron microscopy (TEM). (paper)

  20. Preparation of gold nanoparticles by microwave heating and application of spectroscopy to study conjugate of gold nanoparticles with antibody E. coli O157:H7

    Science.gov (United States)

    Thanh Ngo, Vo Ke; Phuong Uyen Nguyen, Hoang; Phat Huynh, Trong; Nguyen Pham Tran, Nguyen; Lam, Quang Vinh; Dat Huynh, Thanh

    2015-09-01

    Gold nanoparticles (AuNPs) of 15-20 nm size range have attracted attention for producing smart sensing devices as diagnostic tools in biomedical sciences. Citrate capped AuNPs are negatively charged, which can be exploited for electrostatic interactions with some positively charged biomolecules like antibodies. In this paper we describe a method for the low cost synthesis of gold nanoparticles using sodium citrate (Na3Ct) reduction in chloroauric acid (HAuCl4.3H2O) by microwave heating (diameter about 13-15 nm). Gold nanoparticles were functionalized with surface activation by 3-mercaptopropionic acid for attaching antibody. These nanoparticles were then reacted with anti-E. coli O157:H7, using N-hydroxy succinimide (NHS) and carbondimide hydrochloride (EDC) coupling chemistry. The product was characterized with UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy and zeta potential. In addition, the binding of antibody-gold nanoparticles conjugates to E. coli O157:H7 was demonstrated using transmission electron microscopy (TEM).

  1. Biodistribution and PET Imaging of a Novel [(68)Ga]-Anti-CD163-Antibody Conjugate in Rats with Collagen-Induced Arthritis and in Controls

    DEFF Research Database (Denmark)

    Eichendorff, Sascha; Svendsen, Pia; Bender, Dirk

    2015-01-01

    -68 and evaluated stability and binding specificity of the conjugate ([(68)Ga]ED2) in vitro. Furthermore, tracer biodistribution was assessed in vivo in healthy rats and rats with acute collagen-induced arthritis (CIA) by MicroPET and tissue analysis. RESULTS: Radiosynthesis of [(68)Ga]ED2 antibody...... was also changed in the sense that a significantly higher liver uptake and lower spleen uptake of [(68)Ga]ED2 was measured in CIA rats that accordingly showed a corresponding change in level of CD163 expression. CONCLUSIONS: [(68)Ga]ED2 specifically binds CD163 in vitro and in vivo. Biodistribution studies...... in CIA rats suggest that this novel tool may have applications in studies of inflammatory diseases....

  2. Hib antibody responses in infants following diphtheria, tetanus, acellular pertussis, and conjugated Haemophilus influenzae type b (Hib) combination vaccines with decreasing amounts of tetanus toxoid.

    Science.gov (United States)

    Bernstein, Henry H; Seyferth, Elisabeth R

    2017-12-04

    While combination vaccines have contributed to improved vaccine uptake rates in children, studies have documented varied immunogenicity to specific vaccine components. We studied whether varying the amount of tetanus toxoid (TT) in a DTaP and Hib combination vaccine would result in immunogenicity comparable with separate, concurrent administration. We evaluated the immunogenicity of Massachusetts Biologic Laboratories (MBL) diphtheria, tetanus, and acellular pertussis (mDTaP) vaccine combined with tetanus-conjugated MBL Haemophilus influenzae type b vaccine (mHib) in a single injection (DTaPH). We compared four DTaPH vaccines containing varying concentrations of TT. We also evaluated the immune response to the DTaP vaccine manufactured by Connaught Laboratories (now known as Sanofi Pasteur) given with mHib and with Wyeth Hib-CRM 197 (HbOC) as separate injections. Vaccines were administered to 240 healthy infants at 2, 4, and 6 months of age, and blood specimens for antibody determination were obtained before each immunization and one month after the third immunization. We found no significant differences in immune response to the vaccines between the four DTaPH groups. Hib antibody responses were similar in the mHib and the HbOC groups but significantly lower in the DTaPH groups, as measured by Chinese Hamster Ovary (CHO) cell neutralization titers and filamentous hemagglutinin antigen (FHA) geometric mean concentrations (GMC) of anti-Hib antibodies. There were no significant differences between the groups in pertussis or tetanus toxoid antibody levels. Reducing tetanus toxoid amounts did not produce comparable immunogenicity for Hib. The nature of the interaction between immune responses to DTaPH components should be explored further to enable the development of better Hib-containing combination vaccines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. An emerging playbook for antibody-drug conjugates: lessons from the laboratory and clinic suggest a strategy for improving efficacy and safety.

    Science.gov (United States)

    Drake, Penelope M; Rabuka, David

    2015-10-01

    Antibody-drug conjugates (ADCs) have become de rigueur for pharmaceutical oncology drug development pipelines. There are more than 40 ADCs undergoing clinical trials and many more in preclinical development. The field has rushed to follow the initial successes of Kadcyla™ and Adcetris™, and moved forward with new targets without much pause for optimization. In some respects, the ADC space has become divided into the clinical realm-where the proven technologies continue to represent the bulk of clinical candidates with a few exceptions-and the research realm-where innovations in conjugation chemistry and linker technologies have suggested that there is much room for improvement in the conventional methods. Now, two and four years after the approvals of Kadcyla™ and Adcetris™, respectively, consensus may at last be building that these two drugs rely on rather unique target antigens that enable their success. It is becoming increasingly clear that future target antigens will require additional innovative approaches. Next-generation ADCs have begun to move out of the lab and into the clinic, where there is a pressing need for continued innovation to overcome the twin challenges of safety and efficacy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. The effect of varied pH on the luminescence characteristics of antibody-mercaptoacetic acid conjugated ZnS nanowires

    Science.gov (United States)

    Chaudhry, Madeeha; Rehman, Malik Abdul; Gul, Asghari; Qamar, Raheel; Bhatti, Arshad Saleem

    2017-11-01

    We demonstrate here that the effect of varied pH of the media on the photoluminescence (PL) properties of mercaptoacetic acid (MAA) and digoxin antibody (Ab) conjugated zinc sulphide (ZnS) nanowires. The charge-transfer kinetics from MAA to ZnS and vice versa showed a profound effect on the luminescence of ZnS defect states. The PL intensity of the ZnS defect states showed strong dependence on the value of pH with respect to the pKa of MAA. The carboxyl and thiol group of MAA in the protonated (pH pKa) and deprotonated (pH > pKa) states resulted in the quenched PL intensity. While for pH ∼ pKa, the PL intensity was regained as there was equal probability of both protonated and deprotonated carboxyl and thiol groups. These findings indicated that pH of the environment is a key parameter for the use of MAA-Ab conjugated ZnS nanowires as an optical biomarker.

  5. Salivary antibody levels in adolescents in response to a meningococcal serogroup C conjugate booster vaccination nine years after priming : systemically induced local immunity and saliva as potential surveillance tool

    NARCIS (Netherlands)

    Stoof, Susanne P; van der Klis, Fiona R M; van Rooijen, Debbie M; Bogaert, Debby|info:eu-repo/dai/nl/264105834; Trzcinski, Krzysztof|info:eu-repo/dai/nl/323349609; Sanders, Elisabeth A M|info:eu-repo/dai/nl/126771960; Berbers, Guy A M

    2015-01-01

    BACKGROUND: In several countries large-scale immunization of children and young adults with Meningococcal serogroup C (MenC) conjugate vaccines has induced long-standing herd protection. Salivary antibodies may play an important role in mucosal protection against meningococcal acquisition and

  6. Differential regulation of polysaccharide-specific antibody responses to isolated polysaccharides, conjugate vaccines, and intact Gram-positive versus Gram-negative extracellular bacteria.

    Science.gov (United States)

    Snapper, Clifford M

    2016-06-24

    Bacterial capsular polysaccharides are major virulence factors and are key targets in a number of licensed anti-bacterial vaccines. Their major characteristics are their large molecular weight and expression of repeating antigenic epitopes that mediate multivalent B cell receptor cross-linking. In addition, since the majority of these antigens cannot associate with MHC-II they fail to recruit CD4+ T cell help and are referred to as T cell-independent antigens. In this review I will discuss a series of studies from my laboratory that have underscored the importance of understanding polysaccharide-specific antibody responses within the context in which the PS is expressed (i.e. in isolation, as a component of conjugate vaccines, and expressed naturally by intact bacteria). We have shown that multivalent B cell receptor crosslinking, as mediated by polysaccharides, uniquely determines the qualitative response of the B cell to subsequent stimuli, but by itself is insufficient to induce antibody secretion or class switching. For these latter events to occur, second signals must act in concert with primary signals derived from the B cell receptor. The co-expression of polysaccharide and protein within intact bacteria promotes recruitment of CD4+ T cell help for the associated PS-specific IgG response, in contrast to isolated polysaccharides. Further, the particulate nature of extracellular bacteria confers properties to the polysaccharide-specific IgG response that makes it distinct immunologically from soluble conjugate vaccines. Finally, the underlying biochemical and/or structural differences that distinguish Gram-positive and Gram-negative bacteria appear to play critical roles in differentially regulating the associated polysaccharide-specific IgG responses to these groups of pathogens. These studies have a number of implications for the understanding and future design of polysaccharide-based vaccines. Published by Elsevier Ltd.

  7. Bispecific antibody complex pre-targeting and targeted delivery of polymer drug conjugates for imaging and therapy in dual human mammary cancer xenografts. Targeted polymer drug conjugates for cancer diagnosis and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Khaw, Ban-An; Gada, Keyur S.; Patil, Vishwesh; Panwar, Rajiv; Mandapati, Savitri [Northeastern University, Department of Pharmaceutical Sciences, Bouve College of Health Sciences, School of Pharmacy, Boston, MA (United States); Hatefi, Arash [Rutgers University, Department of Pharmaceutics, New Brunswick, NJ (United States); Majewski, Stan [West Virginia University, Department of Radiology, Morgantown, WV (United States); Weisenberger, Andrew [Thomas Jefferson National Accelerator Facility, Jefferson Lab, Newport News, VA (United States)

    2014-08-15

    Doxorubicin, a frontline chemotherapeutic agent, limited by its cardiotoxicity and other tissue toxicities, was conjugated to N-terminal DTPA-modified polyglutamic acid (D-Dox-PGA) to produce polymer pro-drug conjugates. D-Dox-PGA or Tc-99 m labeled DTPA-succinyl-polylysine polymers (DSPL) were targeted to HER2-positive human mammary carcinoma (BT-474) in a double xenografted SCID mouse model also hosting HER2-negative human mammary carcinoma (BT-20). After pretargeting with bispecific anti-HER2-affibody-anti-DTPA-Fab complexes (BAAC), anti-DTPA-Fab or only phosphate buffered saline, D-Dox-PGA or Tc-99 m DSPL were administered. Positive therapeutic control mice were injected with Dox alone at maximum tolerated dose (MTD). Only BT-474 lesions were visualized by gamma imaging with Tc-99 m-DSPL; BT-20 lesions were not. Therapeutic efficacy was equivalent in mice pretargeted with BAAC/targeted with D-Dox-PGA to mice treated only with doxorubicin. There was no total body weight (TBW) loss at three times the doxorubicin equivalent MTD with D-Dox-PGA, whereas mice treated with doxorubicin lost 10 % of TBW at 2 weeks and 16 % after the second MTD injection leading to death of all mice. Our cancer imaging and pretargeted therapeutic approaches are highly target specific, delivering very high specific activity reagents that may result in the development of a novel theranostic application. HER/2 neu specific affibody-anti-DTPA-Fab bispecific antibody pretargeting of HER2 positive human mammary xenografts enabled exquisite targeting of polymers loaded with radioisotopes for molecular imaging and doxorubicin for effective therapy without the associating non-tumor normal tissue toxicities. (orig.)

  8. EpCAM antibody-conjugated mesoporous silica nanoparticles to enhance the anticancer efficacy of carboplatin in retinoblastoma.

    Science.gov (United States)

    Qu, Wei; Meng, Bo; Yu, Yangyang; Wang, Shaowei

    2017-07-01

    Retinoblastoma (RB) is a rare type of tumor which occurs in the intraocular spaces of eye. Carboplatin (CRB) has been used for the treatment of RB along with focal therapy. In this study, we have demonstrated the preparation of EpCAM-conjugated mesoporous silica nanoparticles for the successful delivery of carboplatin (CRB) to the retinoblastoma cells. The particles size and morphology was nanosized and spherical and exhibited a controlled release kinetics. Cellular uptake studies reveal that enhanced internalization was observed for EpCMSN compared to that of CMSN. The remarkable difference in cellular uptake might be attributed to the specific receptor mediated cellular internalization for EpCMSN compared to that of CMSN which might entered the cells by passive diffusion. Consistently, EpCMSN exhibited a superior anticancer effect in retinoblastoma cells. The IC50 value of EpCMSN was 1.38μg/ml which is significantly lesser compared to that of free CRB (3.26μg/ml). EpCMSN resulted in 2-fold increase in caspase-3 level compared to that of free CRB. The higher targeting effect of EpCAM receptor resulted in enhanced apoptosis of cancer cells after treatment with EpCMSN in retinoblastoma cells. Taken together, EpCAM conjugated MSN might be advantageous for the targeted treatment of receptor-overexpressed ocular malignancies like retinoblastoma. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Pneumococcal antibody concentrations of subjects in communities fully or partially vaccinated with a seven-valent pneumococcal conjugate vaccine.

    Directory of Open Access Journals (Sweden)

    Martin O C Ota

    Full Text Available A recent trial with PCV-7 in a rural Gambian community showed reduced vaccine-type pneumococcal carriage in fully vaccinated compared with control communities. We measured pneumococcal polysaccharide antibody concentrations in this trial to understand further the mechanisms underlying the observed changes.A single-blind, cluster-randomized (by village trial was conducted in 21 Gambian villages. In 11 villages, all residents received PCV-7 (Vaccine group; in 10 control villages only children 5.0 µg/mL for all but serotype 9V of the PCV-7 serotypes in the older group, but not in the younger age group.Higher antibodies in vaccinated communities provide an explanation for the lower pneumococcal carriage rates in fully vaccinated compared to control communities.Controlled-Trials.com ISRCTN51695599 51695599.

  10. Antibody-Conjugated Nontoxic Arginine-Doped Fe3O4 Nanoparticles for Magnetic Circulating Tumor Cells Separation

    OpenAIRE

    F. Kashanian; M. M. Masoudi; A. Akbari; A. Shamloo; M. R. Zand; S. S. Salehi

    2017-01-01

    Nano-sized materials present new opportunities in biology and medicine and they are used as biomedical tools for investigation, separation of molecules and cells. To achieve more effective cancer therapy, it is essential to select cancer cells exactly. This research suggests that using the antibody-functionalized nontoxic Arginine-doped magnetic nanoparticles (A-MNPs), has been prosperous in detection, capture, and magnetic separation of circulating tumor cells (CTCs) in tumor tissue. In this...

  11. Noninvasive in vivo multispectral optoacoustic imaging of apoptosis in triple negative breast cancer using indocyanine green conjugated phosphatidylserine monoclonal antibody.

    Science.gov (United States)

    Kannadorai, Ravi Kumar; Udumala, Sunil Kumar; Sidney, Yu Wing Kwong

    2016-12-01

    Noninvasive and nonradioactive imaging modality to track and image apoptosis during chemotherapy of triple negative breast cancer is much needed for an effective treatment plan. Phosphatidylserine (PS) is a biomarker transiently exposed on the outer surface of the cells during apoptosis. Its externalization occurs within a few hours of an apoptotic stimulus by a chemotherapy drug and leads to presentation of millions of phospholipid molecules per apoptotic cell on the cell surface. This makes PS an abundant and accessible target for apoptosis imaging. In the current work, we show that PS monoclonal antibody tagged with indocyanine green (ICG) can help to track and image apoptosis using multispectral optoacoustic tomography multispectral optoacoustic imaging does not involve the use of radioactivity, the longer the circulatory time of the PS antibody can be exploited to monitor apoptosis over a period of time without multiple injections of commonly used imaging probes such as Tc-99m Annexin V or F-18 ML10. The proposed apoptosis imaging technique involving multispectral optoacoustic tomography, monoclonal antibody, and near-infrared absorbing fluorescent marker can be an effective tool for imaging apoptosis and treatment planning.

  12. Specific tumor labeling enhanced by polyethylene glycol linkage of near infrared dyes conjugated to a chimeric anti-carcinoembryonic antigen antibody in a nude mouse model of human pancreatic cancer

    Science.gov (United States)

    Maawy, Ali A.; Hiroshima, Yukihiko; Zhang, Yong; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

    2014-10-01

    Labeling of metastatic tumors can aid in their staging and resection of cancer. Near infrared (NIR) dyes have been used in the clinic for tumor labeling. However, there can be a nonspecific uptake of dye by the liver, lungs, and lymph nodes, which hinders detection of metastasis. In order to overcome these problems, we have used two NIR dyes (DyLight 650 and 750) conjugated to a chimeric anti-carcinoembryonic antigen antibody to evaluate how polyethylene glycol linkage (PEGylation) can improve specific tumor labeling in a nude mouse model of human pancreatic cancer. The conjugated PEGylated and non-PEGylated DyLight 650 and 750 dyes were injected intravenously into non-tumor-bearing nude mice. Serum samples were collected at various time points in order to determine serum concentrations and elimination kinetics. Conjugated PEGylated dyes had significantly higher serum dye concentrations than non-PEGylated dyes (p=0.005 for the 650 dyes and p<0.001 for the 750 dyes). Human pancreatic tumors subcutaneously implanted into nude mice were labeled with antibody-dye conjugates and serially imaged. Labeling with conjugated PEGylated dyes resulted in significantly brighter tumors compared to the non-PEGylated dyes (p<0.001 for the 650 dyes; p=0.01 for 750 dyes). PEGylation of the NIR dyes also decreased their accumulation in lymph nodes, liver, and lung. These results demonstrate enhanced selective tumor labeling by PEGylation of dyes conjugated to a tumor-specific antibody, suggesting their future clinical use in fluorescence-guided surgery.

  13. Antibody persistence 5 years after vaccination at 2 to 10 years of age with Quadrivalent MenACWY-CRM conjugate vaccine, and responses to a booster vaccination.

    Science.gov (United States)

    Block, Stan L; Christensen, Shane; Verma, Bikash; Xie, Fang; Keshavan, Pavitra; Dull, Peter M; Smolenov, Igor

    2015-04-27

    In a multi-center extension study, children 2-10 years of age, initially vaccinated with one or two doses (2-5 year-olds) or one dose (6-10 year-olds) of quadrivalent meningococcal CRM197-conjugate vaccine (MenACWY-CRM), were assessed five years later for antibody persistence and booster response using serum bactericidal assay with human complement (hSBA). Children 7-10 and 11-15 years of age, who received MenACWY-CRM in the original study, and age-matched vaccine-naïve children, were enrolled in this extension study. After an initial blood draw, children received one dose of MenACWY-CRM as booster or primary dose, with a second blood draw 28 days later. hSBA titers decreased five years after primary vaccination, but were higher than in non-vaccinated controls against serogroups C, W and Y, with substantial proportions having titers ≥8: 7-22% for A, 32-57% for C, 74-83% for W, and 48-54% for Y. Previously-vaccinated children demonstrated booster responses to revaccination against all four serogroups. Responses to primary vaccination in vaccine-naïve controls were lower and similar to primary responses observed in the original study. All vaccinations were generally well tolerated, with no safety concern raised. Approximately half the children vaccinated as 2-10 year-olds maintained protective antibodies against serogroups C, W and Y five years later, but fewer did against serogroup A. Declining titers five years after vaccination and robust booster responses suggest that five years may be an appropriate interval to revaccinate children, subject to epidemiology and delivery considerations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Moisture content determination in an antibody-drug conjugate freeze-dried medicine by near-infrared spectroscopy: A case study for release testing.

    Science.gov (United States)

    Clavaud, Matthieu; Roggo, Yves; Dégardin, Klara; Sacré, Pierre-Yves; Hubert, Philippe; Ziemons, Eric

    2016-11-30

    The use of Near-infrared spectroscopy (NIRS) as a fast and non-destructive technique was employed for moisture content (MC) determination in Antibody-drug conjugates (ADCs) in replacement to Karl Fischer (KF) method. The lab analysis of ADCs, high potent medicines, should be performed in conditions ensuring the operator's safety and using secured analytical tools like NIRS. A NIRS method was first developed and validated in compliance with current guidelines. The novelty of this work first lies in the large number of samples prepared for a wide moisture calibration range of 0.51%-4.01%. Then, the classical Partial Least Square (PLS) regression was used as chemometric tool for the computation of the model. Excellent predictive calibration results were shown. A coefficient of correlation (r) value of 0.99 was obtained. An intercept value of 0.02 and a slope of 0.99 were observed, while the root mean square error of calibration (RMSEC) and the root mean square error of prediction (RMSEP) were respectively 0.10% and 0.12%. In addition, instrumentation, model performances and robustness of the method were evaluated, demonstrating the validation results. Calibration transfer issue and impact of the number of samples were also evaluated. Consequently, a validation strategy was introduced as a basis for submission to the health authorities' for release and stability activities in a cGMP environment in replacement of the KF method. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. In Vivo HER2-Targeted Magnetic Resonance Tumor Imaging Using Iron Oxide Nanoparticles Conjugated with Anti-HER2 Fragment Antibody.

    Science.gov (United States)

    Ding, Ning; Sano, Kohei; Kanazaki, Kengo; Ohashi, Manami; Deguchi, Jun; Kanada, Yuko; Ono, Masahiro; Saji, Hideo

    2016-12-01

    The feasibility of iron oxide nanoparticles (IONPs) conjugated with anti-epidermal growth factor receptor 2 (HER2) single-chain antibody (scFv-IONPs) as novel HER2-targeted magnetic resonance (MR) contrast agents was investigated. The scFv-IONPs were prepared and identified. For in vitro MRI, NCI-N87 (HER2 high expression) and SUIT2 (low expression) cells were incubated with scFv-IONPs. For in vivo MRI, NCI-N87 and SUIT2 tumor-bearing mice were intravenously injected with scFv-IONPs and imaged before and 24 h post-injection. The scFv-IONPs demonstrated high transverse relaxivity (296.3 s -1  mM -1 ) and affinity toward HER2 (K D  = 11.7 nM). In the in vitro MRI, NCI-N87 cells treated with scFv-IONPs exhibited significant MR signal reduction (44.6 %) than SUIT2 cells (6.8 %). In the in vivo MRI, decrease of MR signals in NCI-N87 tumors (19.3 %) was more notable than that in SUIT2 tumors (6.2 %). The scFv-IONPs enabled HER2-specific tumor MR imaging, suggesting the potential of scFv-IONPs as a robust HER2-targeted MR contrast agent.

  16. Formulation and Cytotoxicity of Ribosome-Inactivating Protein Mirabilis Jalapa L. Nanoparticles Using Alginate-Low Viscosity Chitosan Conjugated with Anti-Epcam Antibodies in the T47D Breast Cancer Cell Line.

    Science.gov (United States)

    Wicaksono, Psycha Anindya; Name, Sismindari; Martien, Ronny; Ismail, Hilda

    2016-01-01

    Ribosome-inactivating protein (RIP) from Mirabilis jalapa L. leaves has cytotoxic effects on breast cancer cell lines but is less toxic towards normal cells. However, it can easily be degraded after administration so it needs to be formulated into nanoparticles to increase its resistance to enzymatic degradation. The objectives of this study were to develop a protein extract of M. jalapa L. leaves (RIP-MJ) incorporated into nanoparticles conjugated with Anti-EpCAM antibodies, and to determine its cytotoxicity and selectivity in the T47D breast cancer cell line. RIP-MJ was extracted from red-flowered M. jalapa L. leaves. Nanoparticles were formulated based on polyelectrolyte complexation using low viscosity chitosan and alginate, then chemically conjugated with anti-EpCAM antibody using EDAC based on carbodiimide reaction. RIP-MJ nanoparticles were characterised for the particle size, polydispersity index, zeta potential, particle morphology, and entrapment efficiency. The cytotoxicity of RIP-MJ nanoparticles against T47D and Vero cells was then determined with MTT assay. The optimal formula of RIP-MJ nanoparticles was obtained at the concentration of RIP-MJ, low viscosity chitosan and alginate respectively 0.05%, 1%, and 0.4% (m/v). RIP-MJ nanoparticles are hexagonal with high entrapment efficiency of 98.6%, average size of 130.7 nm, polydispersity index of 0.380 and zeta potential +26.33 mV. The IC50 values of both anti-EpCAM-conjugated and non-conjugated RIP-MJ nanoparticles for T47D cells (13.3 and 14.9 μg/mL) were lower than for Vero cells (27.8 and 33.6 μg/mL). The IC50 values of conjugated and non- conjugated RIP-MJ for both cells were much lower than IC50 values of non-formulated RIP-MJ (>500 μg/mL).

  17. A clinical trial examining the effect of increased total CRM(197) carrier protein dose on the antibody response to Haemophilus influenzae type b CRM(197) conjugate vaccine.

    Science.gov (United States)

    Usonis, Vytautas; Bakasenas, Vytautas; Lockhart, Stephen; Baker, Sherryl; Gruber, William; Laudat, France

    2008-08-18

    CRM(197) is a carrier protein in certain conjugate vaccines. When multiple conjugate vaccines with the same carrier protein are administered simultaneously, reduced response to vaccines and/or antigens related to the carrier protein may occur. This study examined responses of infants who, in addition to diphtheria toxoid/tetanus toxoid/acellular pertussis vaccine (DTaP) received either diphtheria CRM(197)-based Haemophilus influenzae type b conjugate vaccine (HbOC) or HbOC and a diphtheria CRM(197)-based combination 9-valent pneumococcal conjugate vaccine/meningococcal group C conjugate vaccine. Administration of conjugate vaccines with CRM(197) carrier protein load >50 microg did not reduce response to CRM(197) conjugate vaccines or immunogenicity to immunologically cross-reactive diphtheria toxoid.

  18. Mortalin antibody-conjugated quantum dot transfer from human mesenchymal stromal cells to breast cancer cells requires cell–cell interaction

    International Nuclear Information System (INIS)

    Pietilä, Mika; Lehenkari, Petri; Kuvaja, Paula; Kaakinen, Mika; Kaul, Sunil C.; Wadhwa, Renu; Uemura, Toshimasa

    2013-01-01

    The role of tumor stroma in regulation of breast cancer growth has been widely studied. However, the details on the type of heterocellular cross-talk between stromal and breast cancer cells (BCCs) are still poorly known. In the present study, in order to investigate the intercellular communication between human mesenchymal stromal cells (hMSCs) and breast cancer cells (BCCs, MDA-MB-231), we recruited cell-internalizing quantum dots (i-QD) generated by conjugation of cell-internalizing anti-mortalin antibody and quantum dots (QD). Co-culture of illuminated and color-coded hMSCs (QD655) and BCCs (QD585) revealed the intercellular transfer of QD655 signal from hMSCs to BCCs. The amount of QD double positive BCCs increased gradually within 48 h of co-culture. We found prominent intercellular transfer of QD655 in hanging drop co-culture system and it was non-existent when hMSCs and BBCs cells were co-cultured in trans-well system lacking imminent cell–cell contact. Fluorescent and electron microscope analyses also supported that the direct cell-to-cell interactions may be required for the intercellular transfer of QD655 from hMSCs to BCCs. To the best of our knowledge, the study provides a first demonstration of transcellular crosstalk between stromal cells and BCCs that involve direct contact and may also include a transfer of mortalin, an anti-apoptotic and growth-promoting factor enriched in cancer cells

  19. Selective modification of NMR relaxation time in human colorectal carcinoma by using gadolinium-diethylenetriaminepentaacetic acid conjugated with monoclonal antibody 19-9.

    Science.gov (United States)

    Curtet, C; Tellier, C; Bohy, J; Conti, M L; Saccavini, J C; Thedrez, P; Douillard, J Y; Chatal, J F; Koprowski, H

    1986-01-01

    Monoclonal antibody 19-9 (mAb 19-9) against human colon adenocarcinoma was conjugated with gadolinium X diethylenetriaminepentaacetic acid (Gd X DTPA) and used as a contrast agent in nuclear magnetic resonance (NMR) in an effort to improve tumor target selectivity in nude mice. The data indicate that Gd X DTPA-mAb 19-9 in solution decreased the T1 relaxation of water protons at 90 MHz in direct proportion to the gadolinium concentration, and this effect was greater than in Gd X DTPA solutions. T1 relaxation time at 90 MHz, measured in tumors removed from nude mice 24 hr after injection of Gd X DTPA-mAb 19-9 (Gd, 20 mumol/kg; 16 DTPA molecules per mAb molecule), was significantly decreased (by 15%) as compared with the control group. Similar results were obtained in tumors from mice injected with Gd X DTPA-mAb 19-9 solutions in which Gd was used at 2, 6, or 10 mumol/kg (16 DTPA molecules per mAb molecule). These doses are lower than those commonly used for Gd X DTPA (10-100 mumol/kg) as contrast agent. Tumor localization by the Gd X DTPA-mAb 19-9 complex containing radioactive Gd (0.3 microCi/microgram of 153Gd) to confirm scintigraphy revealed significant concentrations of the complex (5% of the injected dose per gram of tissue) in the tumor. Scan images recorded in planar scintigraphy at day 5 showed good visualization of tumors. Images PMID:3459174

  20. Three-year antibody persistence and safety after a single dose of combined haemophilus influenzae type b (Hib)-Neisseria meningitidis serogroup C-tetanus toxoid conjugate vaccine in Hib-primed toddlers.

    Science.gov (United States)

    Booy, Robert; Richmond, Peter; Nolan, Terry; McVernon, Jodie; Marshall, Helen; Nissen, Michael; Reynolds, Graham; Ziegler, John B; Stoney, Tanya; Heron, Leon; Lambert, Stephen; Mesaros, Narcisa; Peddiraju, Kavitha; Miller, Jacqueline M

    2013-02-01

    Persistence of seroprotective bactericidal antibody titers is important for long-term protection against meningococcal serogroup C disease in young children. Antibody persistence values were determined in children up to 3 years after vaccination with a single dose of the combined Haemophilus influenzae type b (Hib)-Neisseria meningitidis serogroup C (MenC)-tetanus toxoid (TT) conjugate vaccine (Hib-MenC-TT; www.ClinicalTrials.gov: NCT00326118). The children had been randomized at ages 12-18 months to receive either 1 dose of Hib-MenC-TT (Hib-MenC group) or separately administered Hib-TT conjugate vaccine and MenC-CRM197 (MCC) vaccine (Hib plus MCC group). All children had been primed in infancy with a Hib vaccine. Antibodies against MenC were measured by a serum bactericidal assay using rabbit complement (rSBA-MenC) and antibodies against Hib polyribosylribitol phosphate were assessed by enzyme-linked immunosorbent assay. The rSBA-MenC titers ≥1:8 were demonstrated 3 years after vaccination in 64.2% and 53.2% of participants in the Hib-MenC group and in the Hib plus MCC group, respectively. Antipolyribosylribitol phosphate concentrations ≥0.15 µg/mL persisted in >98% of participants in both groups. The rSBA-MenC geometric mean titers and antipolyribosylribitol phosphate geometric mean concentrations remained higher 3 years after vaccination than before vaccination. No serious adverse events assessed by the investigator as being related to vaccination were reported. In this antibody persistence study of Hib-primed but MenC-naïve toddlers who received a single dose of Hib-MenC-TT, protective antibody levels against Hib and MenC were maintained in the majority of children 3 years after vaccination.

  1. Cancer Cell Targeting Using Folic Acid/Anti-HER2 Antibody Conjugated Fluorescent CdSe/CdS/ZnS-Mercaptopropionic Acid and CdTe-Mercaptosuccinic Acid Quantum Dots.

    Science.gov (United States)

    Singh, Gurpal; Kumar, Manoj; Soni, Udit; Arora, Vikas; Bansal, Vivek; Gupta, Dikshi; Bhat, Madhusudan; Dinda, Amit K; Sapra, Sameer; Singh, Harpal

    2016-01-01

    CdSe/CdS/ZnS and CdTe quantum dots (QDs) were synthesized by successive ion layer adsorption and reaction (SILAR) technique and direct aqueous synthesis respectively using thiol stabilizers. Synthesized CdSe/CdS/ZnS and CdTe QDs stabilized with 3-mercaptopropionic acid (MPA) and mercaptosuccinic acid (MSA) were used as fluorescent labels after conjugation with folic acid (FA) and anti-HER2 antibodies. Photoluminescence quantum yield of folated CdSe/CdS/ZnS-MPA and CdTe-MSA QDs was 59% and 77% than that of non-folated hydrophilic QDs. The folate receptor-mediated delivery of folic acid-conjugated CdTe-MSA and CdSe/CdS/ZnS-MPA QDs showed higher cellular internalization as observed by confocal laser scanning microscopic studies. Folated and non-folated CdTe-MSA QDs were highly toxic and exhibited only 10% cell viability as compared to > 80% cell viability with CdSe/CdS/ZnS-MPA QDs over the concentration ranging from 3.38 to 50 pmoles. Immunohistochemistry (IHC) results of human breast cancer tissue samples showed positive results with anti-HER2 antibody conjugated CdSe/CdS/ZnS-MPA QDs with better sensitivity and specificity as compared to conventional IHC analysis using diaminobenzedene staining.

  2. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  3. Non-epitope-specific suppression of the antibody response to Haemophilus influenzae type b conjugate vaccines by preimmunization with vaccine components

    DEFF Research Database (Denmark)

    Barington, T; Skettrup, M; Juul, L

    1993-01-01

    Recently, conjugate vaccines containing Haemophilus influenzae type b capsular polysaccharide (HibCP) coupled to protein carriers were introduced for use in infants and certain adult risk groups. Similar conjugate vaccines against other capsulated bacteria are currently under development for both...

  4. EMERGE: A Randomized Phase II Study of the Antibody-Drug Conjugate Glembatumumab Vedotin in Advanced Glycoprotein NMB-Expressing Breast Cancer.

    Science.gov (United States)

    Yardley, Denise A; Weaver, Robert; Melisko, Michelle E; Saleh, Mansoor N; Arena, Francis P; Forero, Andres; Cigler, Tessa; Stopeck, Alison; Citrin, Dennis; Oliff, Ira; Bechhold, Rebecca; Loutfi, Randa; Garcia, Agustin A; Cruickshank, Scott; Crowley, Elizabeth; Green, Jennifer; Hawthorne, Thomas; Yellin, Michael J; Davis, Thomas A; Vahdat, Linda T

    2015-05-10

    Glycoprotein NMB (gpNMB), a negative prognostic marker, is overexpressed in multiple tumor types. Glembatumumab vedotin is a gpNMB-specific monoclonal antibody conjugated to the potent cytotoxin monomethyl auristatin E. This phase II study investigated the activity of glembatumumab vedotin in advanced breast cancer by gpNMB expression. Patients (n = 124) with refractory breast cancer that expressed gpNMB in ≥ 5% of epithelial or stromal cells by central immunohistochemistry were stratified by gpNMB expression (tumor, low stromal intensity, high stromal intensity) and were randomly assigned 2:1 to glembatumumab vedotin (n = 83) or investigator's choice (IC) chemotherapy (n = 41). The study was powered to detect overall objective response rate (ORR) in the glembatumumab vedotin arm between 10% (null) and 22.5% (alternative hypothesis) with preplanned investigation of activity by gpNMB distribution and/or intensity (Stratum 1 to Stratum 3). Glembatumumab vedotin was well tolerated as compared with IC chemotherapy (less hematologic toxicity; more rash, pruritus, neuropathy, and alopecia). ORR was 6% (five of 83) for glembatumumab vedotin versus 7% (three of 41) for IC, without significant intertreatment differences for predefined strata. Secondary end point revealed ORR of 12% (10 of 83) versus 12% (five of 41) overall, and 30% (seven of 23) versus 9% (one of 11) for gpNMB overexpression (≥ 25% of tumor cells). Unplanned analysis showed ORR of 18% (five of 28) versus 0% (0 of 11) in patients with triple-negative breast cancer (TNBC), and 40% (four of 10) versus 0% (zero of six) in gpNMB-overexpressing TNBC. Glembatumumab vedotin is well tolerated in heavily pretreated patients with breast cancer. Although the primary end point in advanced gpNMB-expressing breast cancer was not met for all enrolled patients (median tumor gpNMB expression, 5%), activity may be enhanced in patients with gpNMB-overexpressing tumors and/or TNBC. A pivotal phase II trial (METRIC

  5. In vivo tumor targeting and imaging with anti-vascular endothelial growth factor antibody-conjugated dextran-coated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Hsieh WJ

    2012-06-01

    Full Text Available Wan-Ju Hsieh,1 Chan-Jung Liang,1 Jen-Jie Chieh,4 Shu-Huei Wang,1 I-Rue Lai,1 Jyh-Horng Chen,2 Fu-Hsiung Chang,3 Wei-Kung Tseng,4–6 Shieh-Yueh Yang,4 Chau-Chung Wu,7 Yuh-Lien Chen11Institute of Anatomy and Cell Biology, College of Medicine, 2Department of Electrical Engineering, 3Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei, Taiwan; 4Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan; 5Division of Cardiology, Department of Internal Medicine, E-Da Hospital, Taipei, Taiwan; 6Department of Medical Imaging and Radiological Sciences, I-Shou University, Taipei, Taiwan; 7Department of Internal Medicine and Primary Care Medicine, National Taiwan University Hospital, Taipei, TaiwanBackground: Active targeting by specific antibodies combined with nanoparticles is a promising technology for cancer imaging and detection by magnetic resonance imaging (MRI. The aim of the present study is to investigate whether the systemic delivery of antivascular endothelial growth factor antibodies conjugating to the surface of functionalized supermagnetic iron oxide nanoparticles (anti-VEGF-NPs led to target-specific accumulation in the tumor.Methods: The VEGF expression in human colon cancer and in Balb/c mice bearing colon cancers was examined by immunohistochemistry. The distribution of these anti-VEGF-NPs particles or NPs particles were evaluated by MRI at days 1, 2, or 9 after the injection into the jugular vein of Balb/c mice bearing colon cancers. Tumor and normal tissues (liver, spleen, lung, and kidney were collected and were examined by Prussian blue staining to determine the presence and distribution of NPs in the tissue sections.Results: VEGF is highly expressed in human and mouse colon cancer tissues. MRI showed significant changes in the T*2 signal and T2 relaxation in the anti-VEGF-NP- injected-mice, but not in mice injected with NP alone. Examination of paraffin

  6. Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Anne Marie Kay Kovach

    2016-10-01

    Full Text Available Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF antibody and ligand cluster of differentiation 80 (CD80 for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA. The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTMNPO CRL-2836 at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF. Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum

  7. A new bifunctional chelating agent conjugated with monoclonal antibody and labelled with technetium-99m for targeted scintigraphy: 6-(4-isothiocyanatobenzyl)-5,7-dioxo-1,11-(carboxymethyl)-1,4,8,11-tetraazacyclotridecane.

    Science.gov (United States)

    Mishra, Anil Kumar; Panwar, Puja; Hosono, Makoto; Chuttani, Krishna; Mishra, Pushpa; Sharma, Rakesh Kumar; Chatal, Jean-Francois

    2004-01-01

    The purpose of this study was to obtain the convenient, synthetically useful bifunctional chelating agent, 6-(4-isothiocyanatobenzyl)-5,7-dioxo-1,11-(carboxymethyl)-1,4,8,11-tetraazacyclotridecane, and to apply it to stable (99m)Tc-labelling of monoclonal antibodies (mAbs). The chelate was synthesised by reaction of nitrobenzyl malonate and triethylenetetramine followed by alkylation by reacting with bromoacetic acid at pH 10. The amino group was converted to isothiocyanato derivative by reacting with thiophosgene at pH 2.0. Conjugation with mAbs [(anti-carcinoembryonic antigen (CEA) and anti-epidermal growth factor receptor (EGFr)] was performed at pH 8.4 using trisodium phosphate solution by incubating at 37 degrees C for 1 h and subjected to purification on size exclusion chromatography. When radioimmunoconjugates were labelled with (99m)Tc, the specific activity of immunoconjugates was 20-30 mCi/mg of protein and their immunoreactivity exceeded 80%. The stability in serum indicated that the metal remained bound to antibodies. Biodistribution studies in athymic mice grafted with U-87 human glioblastoma multiforme and MDA-MB-468 human breast carcinoma tumours revealed significant localisation of (99m)Tc-labelled antibodies in tumours and reduced accumulation in normal organs. This bifunctional chelating agent is promising for immunoscintigraphy because of good tumour-to-normal organ contrast.

  8. Meningococcal serogroup C immunogenicity, antibody persistence and memory B-cells induced by the monovalent meningococcal serogroup C versus quadrivalent meningococcal serogroup ACWY conjugate booster vaccine: A randomized controlled trial.

    Science.gov (United States)

    van Ravenhorst, Mariëtte B; van der Klis, Fiona R M; van Rooijen, Debbie M; Knol, Mirjam J; Stoof, Susanne P; Sanders, Elisabeth A M; Berbers, Guy A M

    2017-08-24

    Adolescents are considered the key transmitters of meningococci in the population. Meningococcal serogroup C (MenC) antibody levels wane rapidly after MenC conjugate vaccination in young children, leaving adolescents with low antibody levels. In this study, we compared MenC immune responses after booster vaccination in adolescence with either tetanus toxoid conjugated MenC (MenC-TT) or MenACWY (MenACWY-TT) vaccine, and aimed to establish an optimal age for this booster. Healthy 10-, 12-, and 15-year-olds, who received a single dose of MenC-TT vaccine in early childhood, were randomized to receive MenC-TT or MenACWY-TT vaccine. MenC serum bactericidal antibody (rSBA) titers, MenC polysaccharide (PS) specific IgG, IgG1 and IgG2 and MenC-specific IgG and IgA memory B-cells were determined before, one month and one year after the booster. Non-inferiority was tested by comparing geometric mean titers (GMTs) between vaccinees at one year. Of 501 participants, 464 (92.6%) were included in the 'according to protocol' cohort analysis. At one month, all participants developed high MenC rSBA titers (>24,000 in all groups) and MenC-PS-specific IgG levels. Non-inferiority was not demonstrated one year after the booster with higher MenC GMTs after the monovalent vaccine, but 462/464 (99.6%) participants maintained protective MenC rSBA titers. IgG levels mainly consisted of IgG1, but similar levels of increase were observed for IgG1 and IgG2. Both vaccines induced a clear increase in the number of circulating MenC-PS specific IgG and IgA memory B-cells. Between one month and one year, the highest antibody decay rate was observed in the 10-year-olds. Both MenC-TT and MenACWY-TT vaccines induced robust protective MenC immune responses after the booster vaccination, although non-inferiority could not be demonstrated for the MenACWY-TT vaccine after one year. Our results underline the importance of optimal timing of a meningococcal booster vaccination to protect against MenC disease

  9. Catalase and superoxide dismutase conjugated with platelet-endothelial cell adhesion molecule antibody distinctly alleviate abnormal endothelial permeability caused by exogenous reactive oxygen species and vascular endothelial growth factor.

    Science.gov (United States)

    Han, Jingyan; Shuvaev, Vladimir V; Muzykantov, Vladimir R

    2011-07-01

    Reactive oxygen species (ROS) superoxide anion (O(2)()) and hydrogen peroxide (H(2)O(2)) produced by activated leukocytes and endothelial cells in sites of inflammation or ischemia cause endothelial barrier dysfunction that may lead to tissue edema. Antioxidant enzymes (AOEs) catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet-endothelial cell adhesion molecule-1 (PECAM-1) specifically bind to endothelium, quench the corresponding ROS, and alleviate vascular oxidative stress and inflammation. In the present work, we studied the effects of anti-PECAM/catalase and anti-PECAM/SOD conjugates on the abnormal permeability manifested by transendothelial electrical resistance decline, increased fluorescein isothiocyanate-dextran influx, and redistribution of vascular endothelial-cadherin in human umbilical vein endothelial cell (HUVEC) monolayers. Anti-PECAM/catalase protected HUVEC monolayers against H(2)O(2)-induced endothelial barrier dysfunction. Polyethylene glycol-conjugated catalase exerted orders of magnitude lower endothelial uptake and no protective effect, similarly to IgG/catalase. Anti-PECAM/catalase, but not anti-PECAM/SOD, alleviated endothelial hyperpermeability caused by exposure to hypoxanthine/xanthine oxidase, implicating primarily H(2)O(2) in the disruption of the endothelial barrier in this model. Thrombin-induced endothelial permeability was not affected by treatment with anti-PECAM/AOEs or the NADPH oxidase inhibitor apocynin or overexpression of AOEs, indicating that the endogenous ROS play no key role in thrombin-mediated endothelial barrier dysfunction. In contrast, anti-PECAM/SOD, but not anti-PECAM/catalase, inhibited a vascular endothelial growth factor (VEGF)-induced increase in endothelial permeability, identifying a key role of endogenous O(2)() in the VEGF-mediated regulation of endothelial barrier function. Therefore, AOEs targeted to endothelial cells provide versatile molecular tools for testing the roles of

  10. Fiber-Optic Biosensor Employing Alexa-Fluor Conjugated Antibody for Detection of Escherichia coli O157:H7 from Ground Beef in Four Hours

    Science.gov (United States)

    Geng, Tao; Uknalis, Joe; Tu, Su-I; Bhunia, Arun K.

    2006-01-01

    Fiber optic biosensor has a great potential to meet the need for rapid, sensitive, and real-time microbial detection systems. We developed an antibody-based fiber-optic biosensor to rapidly detect low levels of Escherichia coli O157:H7 cells in ground beef. The principle of the sensor is a sandwich immunoassay using an antibody which is specific for E. coli O157:H7. A polyclonal antibody was first immobilized on polystyrene fiber waveguides through a biotin-streptavidin reaction that served as a capture antibody. An Alexa Fluor 647 dye-labeled antibody to E. coli O157:H7 was used to detect cells and generate a specific fluorescent signal, which was acquired by launching a 635 nm laser-light from an Analyte-2000. Fluorescent molecules within several hundred nanometers of the fiber were excited by an evanescent wave, and a portion of the emission light from fluorescent dye transmitted by the fiber and collected by a photodetector at wavelengths of 670 to 710 nm quantitatively. This immunosensor was specific for E. coli O157:H7 compared with multiple other foodborne bacteria. In addition, the biosensor was able to detect as low as 103 CFU/ml pure cultured E. coli O157:H7 cells grown in culture broth. Artificially inoculated E. coli O157:H7 at concentration of 1 CFU/ml in ground beef could be detected by this method after only 4 hours of enrichment.

  11. Five-year Antibody Persistence and Safety After a Single Dose of Combined Haemophilus influenzae Type B Neisseria meningitidis Serogroup C-Tetanus Toxoid Conjugate Vaccine in Haemophilus influenzae Type B-primed Toddlers.

    Science.gov (United States)

    Booy, Robert; Nolan, Terry; Reynolds, Graham; Richmond, Peter; Nissen, Michael; Marshall, Helen; Stoney, Tanya; Van Der Wielen, Marie; Kolhe, Devayani; Miller, Jacqueline M

    2015-12-01

    Antibody persistence is evaluated in healthy Australian children 4 and 5 years postvaccination with a single dose of combined Haemophilus influenzae type b-Neisseria meningitidis serogroup C tetanus toxoid conjugate vaccine (Hib-MenC-TT) compared with separately administered Hib-TT and MenC-CRM197 vaccines (Hib + MCC). This is another follow-up of a phase III, open, randomized, controlled study (NCT00326118), in which 433 Hib-primed but MenC naïve toddlers aged 12-18 months were randomized 3:1 to receive Hib-MenC-TT or Hib + MCC vaccines. Protection against (1) MenC was measured by serum bactericidal antibody assay using rabbit complement (rSBA) and (2) Hib was measured by enzyme-linked immunosorbent assay of antibodies to polyribosylribitol phosphate (anti-PRP). Study children were assessed for any potentially vaccine-related serious adverse events at each persistence study visit. The according-to-protocol cohorts for persistence at years 4 and 5 included 282 and 263 children, respectively. The percentages of children with rSBA-MenC titers ≥1:8 at years 4 and 5 were 12.5% and 19.0%, respectively, in the Hib-MenC group; and 12.3% and 25.0% in the Hib + MCC group. All children in each group had anti-PRP concentrations ≥0.15 μg/mL at year 5. Exploratory analyses suggested no potential differences between groups in rSBA-MenC or anti-PRP antibody persistence. No vaccine-related serious adverse events were reported. Antibody persistence was similar for years 4 and 5 after Hib-MenC-TT or Hib + MCC vaccination, with the majority of children retaining anti-PRP antibody concentrations ≥0.15 μg/mL at both timepoints. The percentage of children retaining rSBA-MenC titers ≥1:8 was low (≤25%), suggesting that a MenC booster dose may be warranted before adolescence.

  12. The future of monoclonal antibody technology

    OpenAIRE

    Zider, Alexander; Drakeman, Donald L

    2010-01-01

    With the rapid growth of monoclonal antibody-based products, new technologies have emerged for creating modified forms of antibodies, including fragments, conjugates and multi-specific antibodies. We created a database of 450 therapeutic antibodies in development to determine which technologies and indications will constitute the “next generation” of antibody products. We conclude that the antibodies of the future will closely resemble the antibodies that have already been approved for commer...

  13. Heavy-chain isotype patterns of human antibody-secreting cells induced by Haemophilus influenzae type b conjugate vaccines in relation to age and preimmunity

    DEFF Research Database (Denmark)

    Barington, T; Juul, Lars; Gyhrs, A

    1994-01-01

    The influence of preexisting immunity on the heavy-chain isotypes of circulating antibody-secreting cells (AbSC) induced by vaccination with Haemophilus influenzae type b (Hib) capsular polysaccharide (HibCP) coupled to tetanus toxoid (TT) or diphtheria toxoid (DT) and by vaccination with TT or DT...

  14. Immunogenicity, Safety and Antibody Persistence of a Booster Dose of Quadrivalent Meningococcal ACWY-tetanus Toxoid Conjugate Vaccine Compared with Monovalent Meningococcal Serogroup C Vaccine Administered Four Years After Primary Vaccination Using the Same Vaccines.

    Science.gov (United States)

    Vesikari, Timo; Forsten, Aino; Bianco, Veronique; Van der Wielen, Marie; Miller, Jacqueline M

    2015-12-01

    We evaluated safety, immunogenicity and antibody persistence of meningococcal serogroups A, C, W and Y tetanus toxoid conjugate vaccine (MenACWY-TT) booster vaccination 4 years after priming of toddlers. This phase III, open-label, controlled study in Finland (NCT00955682) enrolled children previously randomized (3:1) at 12-23 months (NCT00474266) to receive 1 dose of MenACWY-TT or MenC conjugate vaccine (MenC-CRM197). Serum bactericidal antibody titers using rabbit (rSBA, cut-off 1:8) and human complement (hSBA, cut-off 1:8) were assessed at year 3 and 4 after priming and 1 month and 1 year after administration of a booster dose of the same vaccine given for primary vaccination. Reactogenicity and safety were assessed, and vaccination-related serious adverse events were recorded from the time of primary vaccination. Before booster (year 4), 74.1%, 40.4%, 49.3% and 58.2% of MenACWY-TT-recipients retained rSBA titers ≥1:8 for serogroups A, C, W and Y, respectively; 28.8%, 73.2%, 80.6% and 65.4% retained hSBA ≥1:8. Percentages for the MenC-CRM group were 35.6% (rSBA-MenC) and 46.9% (hSBA-MenC). After MenACWY-TT booster, ≥99.5% had rSBA ≥1:8 and hSBA ≥1:8 for each serogroup. After MenC-CRM197 booster, all children had rSBA-MenC ≥1:8 and hSBA-MenC ≥1:8. At year 5, percentages above the cut-off were ≥97.4% (rSBA) and ≥95.5% (hSBA) in MenACWY-TT-vaccinees for each serogroup. The MenACWY-TT booster dose had a clinically acceptable safety profile. No vaccine-related serious adverse events were reported. There was evidence of antibody persistence 4 years after toddlers were primed with MenACWY-TT. Booster vaccination induced robust immune responses for all serogroups with an acceptable safety profile.

  15. Radiohalogenated half-antibodies and maleimide intermediate therefor

    Science.gov (United States)

    Kassis, Amin I.; Khawli, Leslie A.

    1991-01-01

    N-(m-radiohalophenyl) maleimide can be conjugated with a reduced antibody having a mercapto group to provide a radiolabelled half-antibody having immunological specific binding characteristics of whole antibody.

  16. Conjugal violence

    Directory of Open Access Journals (Sweden)

    Simona Mihaiu

    2015-10-01

    Full Text Available Scientific knowledge of different aspects related to conjugal violence is highly important for people directly involved, such as researchers, practitioners and the entire society. In this respect, globally, specialised studies continue to advance, offer correct definitions, clear descriptions, convincing assessments to certain issues, encouraging thus long-term research, since some specialists have managed to overcome restrictive or ideological methods and explanations. Moreover, in practice, debates reach almost all social, political and legal dimensions regarding appropriate and efficient forms of preventing conjugal violence. Unfortunately, in Romania there are fewer research and prevention approaches of this social problem. In general, attention is directed to domestic violence and conjugal violence is dealt with only implicitly. Considering the given context, the aim of the paper is to outline, by analysing specialised literature, a new research direction and implicitly, social intervention. I specify that this article represents a stage in the ongoing postdoctoral research project, entitled "Conjugal homicide. Aggressors and victims".

  17. Technology of DTPA and immunoglobulins conjugation and their attachment to 90Y and 177Lu radionuclides

    International Nuclear Information System (INIS)

    Rekova, M.; Jedinakova-Krizova, V.

    2010-01-01

    The aim of the study of labeling of ligand-antibody conjugates was to find optimal conditions of preparing of these conjugates and appropriate radioactivity of selected nuclide for applications in nuclear medicine. Conjugation of the γ-immunoglobulin G (human or bovine IgG, polyclonal antibodies) and bifunctional chelating agent, diethylenetriaminepentaacetic acid dianhydride (cDTPAA), was carried out. Various values of the cDTPAA/antibody ratio, the weight concentration of polyclonal or monoclonal antibodies (MEM-97) and buffers were used. Further, the labeling conditions of the DTPA-IgG conjugate by radionuclides 90 Y and 177 Lu were optimized, and the labeling yield and the conjugation ratio of prepared radionuclide-DTPA-IgG conjugates was determined. Optimal incubation time of the immunoglobulin conjugation was obtained at 30 min from mixing of individual components. The labeling yield of radionuclide-DTPA-antibody conjugate higher than 95% was achieved. Higher values of conjugation ratio of radionuclide-DTPA-antibody conjugate were achieved in 0.1 mol L -1 carbonate buffer, pH 8.5, and the 0.1 mol L -1 carbonate buffer is suitable for studied conjugation systems. This study showed that the labeling yield as well as the conjugation ratio of tested systems depend on the amount of antibody substance, bifunctional chelating agent/antibody molar ratio and pH value of the buffer used. (author)

  18. Five-year antibody persistence and safety following a booster dose of combined Haemophilus influenzae type b-Neisseria meningitidis serogroup C-tetanus toxoid conjugate vaccine.

    Science.gov (United States)

    Tejedor, Juan Carlos; Merino, José Manuel; Moro, Manuel; Navarro, Maria-Luisa; Espín, José; Omeñaca, Félix; García-Sicilia, José; Moreno-Pérez, David; Ruiz-Contreras, Jesús; Centeno, Fernando; Barrio, Francisco; Cabanillas, Lucia; Muro, Marta; Esporrin, Carlos; De Torres, Maria Jose; Caubet, Magalie; Boutriau, Dominique; Miller, Jacqueline M; Mesaros, Narcisa

    2012-10-01

    Booster vaccination with the combined Haemophilus influenza type b-Neisseria meningitides serogroup C-tetanus toxoid vaccine (Hib-MenC-TT) has been reported to induce different MenC antibody responses depending on the priming vaccines, with a possible impact on long-term protection. Here, the five-year persistence of immune responses induced by a booster dose of Hib-MenC-TT was evaluated in toddlers primed with either Hib-MenC-TT or MenC-TT. This is the follow-up of a phase III, open, randomized study, in which a Hib-MenC-TT booster dose was given at 13.14 months of age to toddlers primed with either 3 doses of Hib-MenC-TT or 2 doses of MenC-TT in infancy. Children in the control group had received 3 primary doses and a booster dose of MenC-CRM197. Functional antibodies against MenC were measured by a serum bactericidal assay with rabbit complement (rSBA-MenC) and antibodies against Hib polyribosylribitol phosphate by enzyme-linked immunosorbent assay. Serious adverse events considered by the investigator to be possibly related to vaccination were to be reported throughout the study. At 66 months postbooster, rSBA-MenC titers ≥8 were retained by 82.6% of children primed with Hib-MenC-TT, 94.1% of children primed with MenC-TT, and 60.9% of children in the control group. All children who received the Hib-MenC-TT booster dose retained anti- polyribosylribitol phosphate concentrations ≥0.15 μg/mL. No serious adverse events considered possibly related to vaccination were reported. There is evidence of good antibody persistence against MenC and Hib for more than five years postbooster vaccination with Hib-MenC TT in toddlers primed with Hib-MenC-TT or MenC-TT.

  19. Antibody persistence up to 5 years after vaccination of toddlers and children between 12 months and 10 years of age with a quadrivalent meningococcal ACWY-tetanus toxoid conjugate vaccine.

    Science.gov (United States)

    Vesikari, Timo; Forsten, Aino; Bianco, Veronique; Van der Wielen, Marie; Miller, Jacqueline M

    2016-01-01

    We studied the persistence of serum bactericidal antibody using rabbit and human complement (rSBA/hSBA, cut-offs 1:8) 5 y after a single dose of meningococcal serogroups A, C, W, Y tetanus toxoid conjugate vaccine (MenACWY-TT) compared with age-appropriate control vaccines in toddlers and children (NCT00427908). Children were previously randomized (3:1) to receive either MenACWY-TT or control vaccine (MenC-CRM197 in 1-<2 y olds; MenACWY-polysaccharide vaccine [Men-PS] in 2-<11 y olds). Subjects with rSBA-MenC titers <1:8 at any time point were revaccinated with MenC conjugate vaccine and discontinued from the study. A repeated measurement statistical model assessed potential selection effects due to drop-outs. At year 5 in MenACWY-TT-vaccinated-toddlers for serogroups A, C, W, and Y respectively, percentages with rSBA titers ≥1:8 were 73.5%, 77.6%, 34.7%, and 42.9%, hSBA ≥1:8 were 35.6%, 91.7%, 82.6% and 80.0%. For MenC-CRM197 recipients, 63.6% had persisting rSBA-MenC titers ≥1:8 and 90.9% had hSBA-MenC ≥1:8 (not significantly different versus MenACWY-TT for either assay: exploratory analyses). In 2-<11 y olds rSBA titers ≥1:8 in MenACWY-TT-vaccinees were 90.8%, 90.8%, 78.6%, and 78.6% and 15.4%, 100%, 0.0%, 7.7% in Men-PS-vaccinees (significantly different for serogroups A, W and Y, exploratory analyses). Serogroups A, W and Y rSBA GMTs were ≥ 26-fold higher in MenACWY-TT-vaccinees. As expected, GMTs modeled at year 5 to assess the impact of subject drop out (mainly for revaccination), appeared lower for serogroup C. No vaccine-related SAEs were reported. Antibody persistence was observed for all serogroups up to 5 y after MenACWY-TT vaccination.

  20. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    The role of proteins as very effective immunogens for the generation of antibodies is indisputable. Nevertheless, cases in which protein usage for antibody production is not feasible or convenient compelled the creation of a powerful alternative consisting of synthetic peptides. Synthetic peptides...... can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery...

  1. Safety, pharmacokinetics, and antitumour activity of trastuzumab deruxtecan (DS-8201), a HER2-targeting antibody-drug conjugate, in patients with advanced breast and gastric or gastro-oesophageal tumours: a phase 1 dose-escalation study.

    Science.gov (United States)

    Doi, Toshihiko; Shitara, Kohei; Naito, Yoichi; Shimomura, Akihiko; Fujiwara, Yasuhiro; Yonemori, Kan; Shimizu, Chikako; Shimoi, Tatsunori; Kuboki, Yasutoshi; Matsubara, Nobuaki; Kitano, Atsuko; Jikoh, Takahiro; Lee, Caleb; Fujisaki, Yoshihiko; Ogitani, Yusuke; Yver, Antoine; Tamura, Kenji

    2017-11-01

    Antibody-drug conjugates have emerged as a powerful strategy in cancer therapy and combine the ability of monoclonal antibodies to specifically target tumour cells with the highly potent killing activity of drugs with payloads too toxic for systemic administration. Trastuzumab deruxtecan (also known as DS-8201) is an antibody-drug conjugate comprised of a humanised antibody against HER2, a novel enzyme-cleavable linker, and a topoisomerase I inhibitor payload. We assessed its safety and tolerability in patients with advanced breast and gastric or gastro-oesophageal tumours. This was an open-label, dose-escalation phase 1 trial done at two study sites in Japan. Eligible patients were at least 20 years old with breast or gastric or gastro-oesophageal carcinomas refractory to standard therapy regardless of HER2 status. Participants received initial intravenous doses of trastuzumab deruxtecan from 0·8 to 8·0 mg/kg and dose-limiting toxicities were assessed over a 21-day cycle; thereafter, dose reductions were implemented as needed and patients were treated once every 3 weeks until they had unacceptable toxic effects or their disease progressed. Primary endpoints included identification of safety and the maximum tolerated dose or recommended phase 2 dosing and were analysed in all participants who received at least one dose of study drug. The dose-escalation study is the first part of a two-part study with the second dose-expansion part ongoing and enrolling patients as of July 8, 2017, in Japan and the USA. This trial is registered at ClinicalTrials.gov, number NCT02564900. Between Aug 28, 2015, and Aug 26, 2016, 24 patients were enrolled and received trastuzumab deruxtecan (n=3 for each of 0·8, 1·6, 3·2, and 8·0 mg/kg doses; n=6 for each of 5·4 and 6·4 mg/kg). Up to the study cutoff date of Feb 1, 2017, no dose-limiting toxic effects, substantial cardiovascular toxic effects, or deaths occurred. One patient was removed from the activity analysis because they

  2. A randomized study to assess the immunogenicity, antibody persistence and safety of a tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine in children aged 2–10 years

    Science.gov (United States)

    Vesikari, Timo; Forstén, Aino; Boutriau, Dominique; Bianco, Véronique; Van der Wielen, Marie; Miller, Jacqueline M.

    2012-01-01

    Incidence of meningococcal diseases is high in children, and effective vaccines are needed for this age group. In this phase II, open, controlled study, 309 children aged 2–10 y from Finland were randomized (3:1) into two parallel groups to receive one dose of meningococcal ACWY-tetanus toxoid conjugate vaccine (ACWY-TT group; n = 231) or a licensed meningococcal ACWY polysaccharide vaccine (Men-PS group; n = 78). Serum bactericidal activity using rabbit complement (rSBA) was evaluated up to three years post-vaccination. Exploratory comparisons suggested that rSBA vaccine response rates and geometric mean titers (GMTs) for each serogroup at one month post-vaccination and rSBA GMTs for serogroups A, W-135 and Y up to three years post-vaccination were higher in the ACWY-TT compared with Men-PS group, but did not detect any difference between groups in terms of rSBA-MenC GMTs at three years post-vaccination; this is explained by the higher proportion of children from the Men-PS group who were excluded because they were re-vaccinated with a monovalent meningococcal serogroup C vaccine due to loss of protective antibody levels against this serogroup. Although there was a higher incidence of local reactogenicity in the ACWY-TT group, general and unsolicited symptoms reporting rates were comparable in both groups. This study showed that MenACWY-TT was immunogenic with a clinically acceptable safety profile in children aged 2–10 y. MenACWY-TT induced higher functional antibody titers for all serogroups, which persisted longer for serogroups A, W-135 and Y, than the MenACWY polysaccharide vaccine. This study has been registered at www.clinicaltrials.gov NCT00427908. PMID:23032168

  3. Gene delivery in malignant B cells using the combination of lentiviruses conjugated to anti-transferrin receptor antibodies and an immunoglobulin promoter.

    Science.gov (United States)

    Leoh, Lai Sum; Morizono, Kouki; Kershaw, Kathleen M; Chen, Irvin S Y; Penichet, Manuel L; Daniels-Wells, Tracy R

    2014-01-01

    We previously developed an antibody-avidin fusion protein (ch128.1Av) specific for the human transferrin receptor 1 (TfR1; CD71) to be used as a delivery vector for cancer therapy and showed that ch128.1Av delivers the biotinylated plant toxin saporin-6 into malignant B cells. However, as a result of widespread expression of TfR1, delivery of the toxin to normal cells is a concern. Therefore, we explored the potential of a dual targeted lentiviral-mediated gene therapy strategy to restrict gene expression to malignant B cells. Targeting occurs through the use of ch128.1Av or its parental antibody without avidin (ch128.1) and through transcriptional regulation using an immunoglobulin promoter. Flow cytometry was used to detect the expression of enhanced green fluorescent protein (EGFP) in a panel of cell lines. Cell viability after specific delivery of the therapeutic gene FCU1, a chimeric enzyme consisting of cytosine deaminase genetically fused to uracil phosphoribosyltransferse that converts the 5-fluorocytosine (5-FC) prodrug into toxic metabolites, was monitored using the MTS or WST-1 viability assay. We found that EGFP was specifically expressed in a panel of human malignant B-cell lines, but not in human malignant T-cell lines. EGFP expression was observed in all cell lines when a ubiquitous promoter was used. Furthermore, we show the decrease of cell viability in malignant plasma cells in the presence of 5-FC and the FCU1 gene. The present study demonstrates that gene expression can be restricted to malignant B cells and suggests that this dual targeted gene therapy strategy may help to circumvent the potential side effects of certain TfR1-targeted protein delivery approaches. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Protein carriers of conjugate vaccines

    Science.gov (United States)

    Pichichero, Michael E

    2013-01-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

  5. Validation of analytical method to calculate the concentration of conjugated monoclonal antibody; Validacao de metodo analitico para calculo de concentracao de anticorpo monoclonal conjugado

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Lais F.; Massicano, Adriana V.F.; Oliveira, Ricardo S.; Araujo, Elaine B. de, E-mail: lais_alcarde@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of this study was to develop a quantitative analytical method using high performance liquid chromatography (HPLC) to determine the antibody concentration in conjunction with bifunctional chelator. Assays were performed using a high performance liquid chromatograph, and the following conditions were used: flow rate of 1 mL / min, 15 min run time, 0.2 M sodium phosphate buffer pH 7.0 as the mobile phase and column of molecular exclusion BioSep SEC S-3000 (300 x 7.8 mm, 5 μM - Phenomenex). The calibration curve was obtained with AcM diluted in 0.2 M sodium phosphate buffer pH 7.0 by serial dilution, yielding the concentrations: 400 μg/mL, 200 μg/mL, 100 μg/mL, 50 μg/mL, 25 μg/mL and 12.5 μg/mL. From the calibration curve calculated the equation of the line and with it the concentration of the immunoconjugate. To ensure the validity of the method accuracy and precision studies were conducted. The accuracy test consisted in the evaluation of 3 samples of known concentration, being this test performed with low concentrations (50 μg/mL), medium (100 μg/mL) and high (200 μg/mL). The precision test consisted of 3 consecutive measurements of one sample of known concentration, subject to the conditions set forth above for the other tests. The correlation coefficient of the standard curve was greater than 97%, the accuracy was satisfactory at low concentrations as well as accuracy. The method was validated by showing it for the accurate and precise determination of the concentration of the immunoconjugate. Furthermore, this assay was found to be extremely important, because using the correct mass of the protein, the radiochemical purity of the radioimmunoconjugate was above 95% in all studies.

  6. Glutathione Conjugation

    Science.gov (United States)

    Shimabukuro, R. H.; Frear, D. S.; Swanson, H. R.; Walsh, W. C.

    1971-01-01

    The primary factor for atrazine selectivity in corn (Zea mays) is the activity of a soluble enzyme, glutathione S-transferase, which detoxifies atrazine by catalyzing the formation of an atrazine-glutathione conjugate (GS-atrazine). The nonenzymatic, benzoxazinone-catalyzed hydrolysis of atrazine to hydroxyatrazine contributed to the total resistance of corn to atrazine, but the nonenzymatic detoxication pathway does not seem to be essential for resistance. All corn lines investigated, except for susceptible GT112, rapidly detoxified atrazine by glutathione conjugation. Only GT112 had low glutathione S-transferase activity. Hydroxyatrazine was found in significant quantities only when atrazine was introduced initially into the roots. The amount of hydroxyatrazine formed was nearly equal for susceptible GT112 and most of the resistant corn lines investigated. This investigation indicates that some plants protect themselves against toxic organic halide compounds with a mechanism similar to that known to exist in animals. PMID:5543779

  7. Antibody pretargeting advances cancer radioimmunodetection and radioimmunotherapy.

    Science.gov (United States)

    Goldenberg, David M; Sharkey, Robert M; Paganelli, Giovanni; Barbet, Jacques; Chatal, Jean-François

    2006-02-10

    This article reviews the methods of pretargeting, which involve separating the targeting antibody from the subsequent delivery of an imaging or therapeutic agent that binds to the tumor-localized antibody. This provides enhanced tumor:background ratios and the delivery of a higher therapeutic dose than when antibodies are directly conjugated with radionuclides, as currently practiced in cancer radioimmunotherapy. We describe initial promising clinical results using streptavidin-antibody constructs with biotin-radionuclide conjugates in the treatment of patients with malignant gliomas, and of bispecific antibodies with hapten-radionuclides in the therapy of tumors expressing carcinoembryonic antigen, such as medullary thyroid and small-cell lung cancers.

  8. Radioimmunoassay method for detection of gonorrhea antibodies

    International Nuclear Information System (INIS)

    1975-01-01

    A novel radioimmunoassay for the detection of gonorrhea antibodies in serum is described. A radionuclide is bound to gonorrhea antigens produced by a growth culture. In the presence of gonorrhea antibodies in the serum, an antigen-antibody conjugate is formed, the concentration of which can be measured with conventional radiometric methods. The radioimmunoassay is highly specific

  9. Parallel synthesis and screening of peptide conjugates.

    Science.gov (United States)

    Dirksen, Anouk; Madsen, Mark; Dello Iacono, Giuseppe; Matin, Marla J; Bacica, Michael; Stanković, Nebojša; Callans, Sherri; Bhat, Abhijit

    2014-06-18

    Peptide conjugates represent an emerging class of therapeutics. However, in contrast to that of small molecules and peptides, the discovery and optimization of peptide conjugates is low in throughput, resource intensive, time-consuming, and based on educated decisions rather than screening. A strategy for the parallel synthesis and screening of peptide conjugates is presented that (1) reduces variability in the conjugation steps; (2) provides a new method to rapidly and quantitatively measure conversion in crude conjugation mixtures; (3) introduces a purification step using an immobilized chemical scavenger that does not rely on protein-specific binding; and (4) is supported by robust analytical methods to characterize the large number of end products. Copper-free click chemistry is used as the chemoselective ligation method for conjugation and purification. The productivity in the generation and screening of peptide conjugates is significantly improved by applying this strategy as is demonstrated by the optimization of the anti-Angiopoietin-2 (Ang2) CovX-body, CVX-060, a peptide-antibody scaffold conjugate that has advanced in clinical trials for oncology indications.

  10. Antibody Production with Synthetic Peptides.

    Science.gov (United States)

    Lee, Bao-Shiang; Huang, Jin-Sheng; Jayathilaka, Lasanthi P; Lee, Jenny; Gupta, Shalini

    2016-01-01

    Peptides (usually 10-20 amino acid residues in length) can be used as effectively as proteins in raising antibodies producing both polyclonal and monoclonal antibodies routinely with titers higher than 20,000. Peptide antigens do not function as immunogens unless they are conjugated to proteins. Production of high quality antipeptide antibodies is dependent upon peptide sequence selection, the success of peptide synthesis, peptide-carrier protein conjugation, the humoral immune response in the host animal, the adjuvant used, the peptide dose administered, the injection method, and the purification of the antibody. Peptide sequence selection is probably the most critical step in the production of antipeptide antibodies. Although the process for designing peptide antigens is not exact, several guidelines and computational B-cell epitope prediction methods can help maximize the likelihood of producing antipeptide antibodies that recognize the protein. Antibodies raised by peptides have become essential tools in life science research. Virtually all phospho-specific antibodies are now produced using phosphopeptides as antigens. Typically, 5-20 mg of peptide is enough for antipeptide antibody production. It takes 3 months to produce a polyclonal antipeptide antibody in rabbits that yields ~100 mL of serum which corresponds to ~8-10 mg of the specific antibody after affinity purification using a peptide column.

  11. Immunogenicity of novel sulfadimethoxide conjugates | Chen ...

    African Journals Online (AJOL)

    Immunogenicity of novel sulfadimethoxide conjugates. L Chen, J Su, X Zhang, L Li, X He. Abstract. Sulfadimethoxine (SDM) is an antibiotic commonly added to animal feeds. Anti-SDM antibodies are useful for the detection of residual SDM in foods, feeds and biological fluids by ELISA. In this study, we show that SDM is ...

  12. Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

    DEFF Research Database (Denmark)

    Houen, G.; Olsen, D.T.; Hansen, P.R.

    2003-01-01

    of ovalbumin and various peptides were prepared in a similar manner and used for production of peptide antisera by direct immunization with the conjugates bound to the ion exchanger. Advantages of the method are its solid-phase nature, allowing fast and efficient reactions and intermediate washings......, and immunization experiments with the eluted conjugates showed that the more substituted conjugates gave rise to the highest titers of glutathione antibodies. Direct immunization with the conjugates adsorbed to the ion exchange matrix was possible and gave rise to high titers of glutathione antibodies. Conjugates...

  13. Site-Selective Conjugation of Native Proteins with DNA

    DEFF Research Database (Denmark)

    Trads, Julie Brender; Tørring, Thomas; Gothelf, Kurt Vesterager

    2017-01-01

    -protein conjugates. In DNA nanotechnology, the DNA handle is exploited to precisely position proteins by self-assembly. For these applications, site-selective conjugation is almost always desired because fully functional proteins are required to maintain the specificity of antibodies and the activity of enzymes...... because approximately one-third of all wild-type proteins contain metal-binding sites, including many IgG antibodies, and it is also applicable to His-tagged proteins. This emerging field provides direct access to site-selective conjugates of DNA to commercially available proteins. In this Account, we...

  14. Segmented conjugated polymers

    Indian Academy of Sciences (India)

    Segmented conjugated polymers, wherein the conjugation is randomly truncated by varying lengths of non-conjugated segments, form an interesting class of polymers as they not only represent systems of varying stiffness, but also ones where the backbone can be construed as being made up of chromophores of varying ...

  15. Site-specifically radioiodinated antibody for targeting tumors

    International Nuclear Information System (INIS)

    Rea, D.W.; Ultee, M.E.; Belinka, B.A. Jr.; Coughlin, D.J.; Alvarez, V.L.

    1990-01-01

    Labeling of an antibody site specifically through its carbohydrate regions preserves its antigen-binding activity. Previously site-specific labeling studies have conjugated antibodies with metallic radioisotopes or drugs. We now report site-specific labeling with a new radioiodinated compound, 2-hydroxy-5-iodo-3-methylbenzoyl hydrazide, whose synthesis we described earlier. The compound is reacted with aldehyde groups produced by specific oxidation of the carbohydrate portion of the antibody with sodium m-periodate. Optimized conjugation conditions give good recovery of active antibody containing 10 groups per molecule. The conjugate is stable in solution for at least several weeks at both 4 and -70 degrees C. When injected into nude mice bearing LS174T human cancer xenografts, the conjugate of B72.3 antibody localizes well to tumor tissue, with low uptake by other organs. This biodistribution is similar to that of conjugate prepared by using solid-phase chloramine-T (Iodohead). There are only two significant differences. First, the carbohydrate conjugate is much less susceptible to dehalogenation, and thus shows much less thyroid uptake. Secondly, the biological half-life of the carbohydrate conjugate was about half that of the chloramine-T one. This could be due primarily to lysis of the hydrazine bond through which the antibody is attached to the compound, which would then be excreted rapidly by itself. The new reagent will be especially useful for antibodies which either cannot be labeled by chloramine-T methods, or whose activity is impaired by them

  16. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, Paul Robert; Houen, Gunnar

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors...... such as structure, accessibility and amino acid composition are crucial. Since small peptides tend not to be immunogenic, it may be necessary to conjugate them to carrier proteins in order to enhance immune presentation. Several strategies for conjugation of peptide-carriers applied for immunization exist...

  17. Antibody-Directed Phototherapy (ADP

    Directory of Open Access Journals (Sweden)

    M. Adil Butt

    2013-04-01

    Full Text Available Photodynamic therapy (PDT is a clinically-approved but rather under-exploited treatment modality for cancer and pre-cancerous superficial lesions. It utilises a cold laser or LED to activate a photochemical reaction between a light activated drug (photosensitiser-drug and oxygen to generate cytotoxic oxygen species. These free radical species damage cellular components leading to cell death. Despite its benefits, the complexity, limited potency and side effects of PDT have led to poor general usage. However, the research area is very active with an increasing understanding of PDT-related cell biology, photophysics and significant progress in molecular targeting of disease. Monoclonal antibody therapy is maturing and the next wave of antibody therapies includes antibody-drug conjugates (ADCs, which promise to be more potent and curable. These developments could lift antibody-directed phototherapy (ADP to success. ADP promises to increase specificity and potency and improve drug pharmacokinetics, thus delivering better PDT drugs whilst retaining its other benefits. Whole antibody conjugates with first generation ADP-drugs displayed problems with aggregation, poor pharmacokinetics and loss of immuno-reactivity. However, these early ADP-drugs still showed improved selectivity and potency. Improved PS-drug chemistry and a variety of conjugation strategies have led to improved ADP-drugs with retained antibody and PS-drug function. More recently, recombinant antibody fragments have been used to deliver ADP-drugs with superior drug loading, more favourable pharmacokinetics, enhanced potency and target cell selectivity. These improvements offer a promise of better quality PDT drugs.

  18. Macrocyclic Radiochelates for Antibody Imaging and Therapy of Breast Cancer

    National Research Council Canada - National Science Library

    Lewis, Michael

    1998-01-01

    Conjugation of bifunctional chelating agents allows monoclonal antibodies (mAbs) to be labeled with radiometals for delivery of diagnostic or therapeutic radiation to primary breast tumors or metastatic disease...

  19. Atomic force bio-analytics of polymerization and aggregation of phycoerythrin-conjugated immunoglobulin G molecules

    Science.gov (United States)

    Chen, Yong; Cai, Jiye; Xu, Qingcai; Chen, Zheng W.

    2010-01-01

    While bio-labeled immunoglobulin (IgG) or antibodies are extensively used in imaging studies and therapeutic modality, there have been no reports describing atomic force microscopy (AFM) micrographs of these labeled IgG molecules. Here, AFM studies of phycoerythrin (PE)-conjugated IgG were undertaken to examine whether PE conjugation induced conformational changes or molecular interaction, and subsequently resulted in an alteration in nano-structures of PE-conjugated IgG complex. Once immobilized on mica, single PE-conjugated IgG molecule exhibited globular shape with approximately 60 microns in diameter and 5 microns in height. PE-conjugated IgG were able to form monomers, spindle-like trimers, and hexamers that developed through an end–end connection of two trimers, after they were continuously immobilized on mica. Interestingly, these multimers could aggregate in different directions to form circular monolayers with a highly dense core of PE-conjugated IgG polymers. The formation of these well-organized polymers and aggregates of PE-conjugated IgG may be attributed to the PE conjugation as well as the air–liquid tension on subtract. These findings may help to understand the nano-structures of bio-labeled IgG or antibodies, and facilitate the potential use of PE-conjugated antibodies as markers or immunosensers for AFM bio-analytics of biomolecules in cells and membranes. PMID:15482861

  20. Nanobody-photosensitizer conjugates for targeted photodynamic therapy

    NARCIS (Netherlands)

    Heukers, Raimond; van Bergen en Henegouwen, P; Oliveira, Sabrina

    2014-01-01

    Photodynamic therapy (PDT) induces cell death through light activation of a photosensitizer (PS). Targeted delivery of PS via monoclonal antibodies has improved tumor selectivity. However, these conjugates have long half-lives, leading to relatively long photosensitivity in patients. In an attempt

  1. Meningococcal conjugate vaccines: optimizing global impact

    Directory of Open Access Journals (Sweden)

    Terranella A

    2011-09-01

    Full Text Available Andrew Terranella1,2, Amanda Cohn2, Thomas Clark2 1Epidemic Intelligence Service, Division of Applied Sciences, Scientific Education and Professional Development Program Office, 2Meningitis and Vaccine Preventable Diseases Branch, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA Abstract: Meningococcal conjugate vaccines have several advantages over polysaccharide vaccines, including the ability to induce greater antibody persistence, avidity, immunologic memory, and herd immunity. Since 1999, meningococcal conjugate vaccine programs have been established across the globe. Many of these vaccination programs have resulted in significant decline in meningococcal disease in several countries. Recent introduction of serogroup A conjugate vaccine in Africa offers the potential to eliminate meningococcal disease as a public health problem in Africa. However, the duration of immune response and the development of widespread herd immunity in the population remain important questions for meningococcal vaccine programs. Because of the unique epidemiology of meningococcal disease around the world, the optimal vaccination strategy for long-term disease prevention will vary by country. Keywords: conjugate vaccine, meningitis, meningococcal vaccine, meningococcal disease

  2. Qualidade conjugal: mapeando conceitos

    Directory of Open Access Journals (Sweden)

    Clarisse Mosmann

    2006-12-01

    Full Text Available Apesar da ampla utilização do conceito de qualidade conjugal, identifica-se falta de clareza conceitual acerca das variáveis que o compõem. Esse artigo apresenta revisão da literatura na área com o objetivo de mapear o conceito de qualidade conjugal. Foram analisadas sete principais teorias sobre o tema: Troca Social, Comportamental, Apego, Teoria da Crise, Interacionismo Simbólico. Pelos postulados propostos nas diferentes teorias, podem-se identificar três grupos de variáveis fundamentais na definição da qualidade conjugal: recursos pessoais dos cônjuges, contexto de inserção do casal e processos adaptativos. Neste sentido, a qualidade conjugal é resultado do processo dinâmico e interativo do casal, razão deste caráter multidimensional.

  3. Conjugated Polymer Solar Cells

    National Research Council Canada - National Science Library

    Paraschuk, Dmitry Y

    2006-01-01

    This report results from a contract tasking Moscow State University as follows: Conjugated polymers are promising materials for many photonics applications, in particular, for photovoltaic and solar cell devices...

  4. Polymers for Protein Conjugation

    Directory of Open Access Journals (Sweden)

    Gianfranco Pasut

    2014-01-01

    Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

  5. Synthesis and antimicrobial activity of gold nanoparticle conjugates with cefotaxime

    Science.gov (United States)

    Titanova, Elena O.; Burygin, Gennady L.

    2016-04-01

    Gold nanoparticles (GNPs) have attracted significant interest as a novel platform for various applications to nanobiotechnology and biomedicine. The conjugates of GNPs with antibiotics and antibodies were also used for selective photothermal killing of protozoa and bacteria. Also the conjugates of some antibiotics with GNPs decreased the number of bacterial growing cells. In this work was made the procedure optimization for conjugation of cefotaxime (a third-generation cephalosporin antibiotic) with GNPs (15 nm) and we examined the antimicrobial properties of this conjugate to bacteria culture of E. coli K-12. Addition of cefotaxime solution to colloidal gold does not change their color and extinction spectrum. For physiologically active concentration of cefotaxime (3 μg/mL), it was shown that the optimum pH for the conjugation was more than 9.5. A partial aggregation of the GNPs in saline medium was observed at pH 6.5-7.5. The optimum concentration of K2CO3 for conjugation cefotaxime with GNPs-15 was 5 mM. The optimum concentration of cefotaxime was at 0.36 μg/mL. We found the inhibition of the growth of E. coli K12 upon application cefotaxime-GNP conjugates.

  6. The future of antibodies as cancer drugs.

    Science.gov (United States)

    Reichert, Janice M; Dhimolea, Eugen

    2012-09-01

    Targeted therapeutics such as monoclonal antibodies (mAbs) have proven successful as cancer drugs. To profile products that could be marketed in the future, we examined the current commercial clinical pipeline of mAb candidates for cancer. Our analysis revealed trends toward development of a variety of noncanonical mAbs, including antibody-drug conjugates (ADCs), bispecific antibodies, engineered antibodies and antibody fragments and/or domains. We found substantial diversity in the antibody sequence source, isotype, carbohydrate residues, targets and mechanisms of action (MOA). Although well-validated targets, such as epidermal growth factor receptor (EGFR) and CD20, continue to provide opportunities for companies, we found notable trends toward targeting less-well-validated antigens and exploration of innovative MOA such as the generation of anticancer immune responses or recruitment of cytotoxic T cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Antibody or Antibody Fragments: Implications for Molecular Imaging and Targeted Therapy of Solid Tumors

    Directory of Open Access Journals (Sweden)

    Katerina T. Xenaki

    2017-10-01

    Full Text Available The use of antibody-based therapeutics has proven very promising for clinical applications in cancer patients, with multiple examples of antibodies and antibody–drug conjugates successfully applied for the treatment of solid tumors and lymphomas. Given reported recurrence rates, improvements are clearly still necessary. A major factor limiting the efficacy of antibody-targeted cancer therapies may be the incomplete penetration of the antibody or antibody–drug conjugate into the tumor. Incomplete tumor penetration also affects the outcome of molecular imaging, when using such targeting agents. From the injection site until they arrive inside the tumor, targeting molecules are faced with several barriers that impact intratumoral distribution. The primary means of antibody transport inside tumors is based on diffusion. The diffusive penetration inside the tumor is influenced by both antibody properties, such as size and binding affinity, as well as tumor properties, such as microenvironment, vascularization, and targeted antigen availability. Engineering smaller antibody fragments has shown to improve the rate of tumor uptake and intratumoral distribution. However, it is often accompanied by more rapid clearance from the body and in several cases also by inherent destabilization and reduction of the binding affinity of the antibody. In this perspective, we discuss different cancer targeting approaches based on antibodies or their fragments. We carefully consider how their size and binding properties influence their intratumoral uptake and distribution, and how this may affect cancer imaging and therapy of solid tumors.

  8. Antiprothrombin Antibodies

    Directory of Open Access Journals (Sweden)

    Polona Žigon

    2015-05-01

    Full Text Available In patients with the antiphospholipid syndrome (APS, the presence of a group of pathogenic autoantibodies called antiphospholipid antibodies causes thrombosis and pregnancy complications. The most frequent antigenic target of antiphospholipid antibodies are phospholipid bound β2-glycoprotein 1 (β2GPI and prothrombin. The international classification criteria for APS connect the occurrence of thrombosis and/or obstetric complications together with the persistence of lupus anticoagulant, anti-cardiolipin antibodies (aCL and antibodies against β2GPI (anti-β2GPI into APS. Current trends for the diagnostic evaluation of APS patients propose determination of multiple antiphospholipid antibodies, among them also anti-prothrombin antibodies, to gain a common score which estimates the risk for thrombosis in APS patients. Antiprothrombin antibodies are common in APS patients and are sometimes the only antiphospholipid antibodies being elevated. Methods for their determination differ and have not yet been standardized. Many novel studies confirmed method using phosphatidylserine/prothrombin (aPS/PT ELISA as an antigen on solid phase encompass higher diagnostic accuracy compared to method using prothrombin alone (aPT ELISA. Our research group developed an in-house aPS/PT ELISA with increased analytical sensitivity which enables the determination of all clinically relevant antiprothrombin antibodies. aPS/PT exhibited the highest percentage of lupus anticoagulant activity compared to aCL and anti-β2GPI. aPS/PT antibodies measured with the in-house method associated with venous thrombosis and presented the strongest independent risk factor for the presence of obstetric complications among all tested antiphospholipid antibodies

  9. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  10. Photoluminescence in conjugated polymers

    International Nuclear Information System (INIS)

    Furst, J.E.; Laugesen, R.; Dastoor, P.; McNeill, C.

    2002-01-01

    Full text: Conjugated polymers combine the electronic and optical properties of semiconductors with the processability of polymers. They contain a sequence of alternate single and double carbon bonds so that the overlap of unhybridised p z orbitals creates a delocalised ρ system which gives semiconducting properties with p-bonding (valence) and p* -antibonding (conduction) bands. Photoluminesence (PL) in conjugated polymers results from the radiative decay of singlet excitons confined to a single chain. The present work is the first in a series of studies in our laboratory that will characterize the optical properties of conjugated polymers. The experiment involves the illumination of thin films of conjugated polymer with UV light (I=360 nm) and observing the subsequent fluorescence using a custom-built, fluorescence spectrometer. Photoluminesence spectra provide basic information about the structure of the polymer film. A typical spectrum is shown in the accompanying figure. The position of the first peak is related to the polymer chain length and resolved multiple vibronic peaks are an indication of film structure and morphology. We will also present results related to the optical degradation of these materials when exposed to air and UV light

  11. Ultraviolet phase conjugation

    International Nuclear Information System (INIS)

    Slatkine, M.; Bigio, I.J.; Fisher, R.A.; Maloney, M.L.; Busse, J.R.; Tercovich, R.G.; Feldman, B.J.

    1981-01-01

    Diffraction-limited phase conjugate reflection of an injection-locked high-power (approx. 1 MW) ultraviolet excimer laser beam has been demonstrated via stimulated Brillouin scattering. Reflectivities higher than 70% were attained. Limitations as well as coherence and power requirements for image retention are discussed

  12. Crisis and Conjugal Power

    Science.gov (United States)

    Bahr, Stephen L.; Rollins, Boyd C.

    1971-01-01

    It was hypothesized that the more equalitarian the conjugal power structure in a noncrisis situation, the more likely the relative marital power will change during a crisis. This was tested using an observational experimental method, and the hypothesis was supported. (Author/CG)

  13. Protein carriers of conjugate vaccines: characteristics, development, and clinical trials.

    Science.gov (United States)

    Pichichero, Michael E

    2013-12-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products.

  14. Humoral response to conjugate pneumococcal vaccine in paediatric oncology patients.

    Science.gov (United States)

    Cheng, Frankie Wai Tsoi; Ip, Margaret; Chu, Yvonne Yuen Ling; Lin, Zheng; Lee, Vincent; Shing, Ming Kong; Leung, Wing Kwan; Yuen, Patrick Man Pan; Li, Chi Kong

    2012-04-01

    Pneumococcal conjugate vaccine (PCV) is an effective way to prevent invasive pneumococcal diseases in high risk populations. The efficacy of this vaccine in paediatric oncology patients remains unknown. The authors evaluated the antibody response to seven pneumococcal serotypes in paediatric oncology patients given two doses of heptavalent PCV (PCV-7). Forty-four patients (20 males; 24 females) with median age 9.5 years were studied. After two doses of PCV-7, 86-100% of patients had protective antibody titres against the seven vaccine serotypes. Increases in geometric mean antibody concentrations ranged from 3.8-fold for serotype 19F to 85.8-fold for serotype 14. There was no documented invasive pneumococcal disease in our cohort during the study period. PCV can elicit protective antipneumococcal antibody responses in paediatric oncology patients.

  15. High Mobility Conjugated Polymers

    Science.gov (United States)

    2007-10-20

    blends with poly(3- hexylthiophene) (PHT) could be readily fabricated as uniform nanofibers by co- electrospinning their solutions with another solution...We have demonstrated that nanofibers of conjugated 10 - polymers and their blends could be conveniently fabricated by electrospinning . Furthermore, we...luminance o - - characteristics of an ITO/ PEDOT /TAPC k D r a Vol gt, V, (V) /BPQ-PPO/LiF/A! device are shown in Fig. 30. (A) Current density-voltage

  16. Preparation and biological evaluation of radiolabelled antibodies with selected carbohydrate modifications

    International Nuclear Information System (INIS)

    Qi, P.; Koganty, R.R.; Selvaraj, S.

    1993-01-01

    Two carbohydrates, N-acetylgalactosamine (GalNAc) and galactose-β-1,3-GalNAc have been attached to human IgG (hIgG) by a novel linking reagent, hexafluoroglutaric acid dimethyl ester. Fluorine-19 NMR signals were used for the determination of the conjugation ratio. A third carbohydrate, sialic acid, was conjugated via reductive amination and the conjugation ratio determined by a resorcinol assay. The biological behaviour of these radiodinated antibodies with carbohydrate modification in normal mice indicates an enhanced liver uptake at 15 min post-injection with an associated change in circulating blood levels occurs for the galactose-based hIgG preparations. However, no significant differences in the biodistribution were observed for the sialic acid conjugate. These studies confirm the potential of carbohydrate-antibody conjugation for modifying the behaviour of antibodies in immunoscintigraphy and radioimmunotherapy. (author)

  17. Biological characterization of cetuximab-conjugated gold nanoparticles in a tumor animal model

    Science.gov (United States)

    Kao, Hao-Wen; Lin, Yi-Yu; Chen, Chao-Cheng; Chi, Kwan-Hwa; Tien, Der-Chi; Hsia, Chien-Chung; Lin, Wuu-Jyh; Chen, Fu-Du; Lin, Ming-Hsien; Wang, Hsin-Ell

    2014-07-01

    Gold nanoparticles (AuNPs) are widely applied to the diagnosis and treatment of cancer and can be modified to contain target-specific ligands via gold-thiolate bonding. This study investigated the pharmacokinetics and microdistribution of antibody-mediated active targeting gold nanoparticles in mice with subcutaneous lung carcinoma. We conjugated AuNPs with cetuximab (C225), an antibody-targeting epidermal growth factor receptor (EGFR), and then labeled with In-111, which created EGFR-targeted AuNPs. In vitro studies showed that after a 2 h incubation, the uptake of C225-conjugated AuNPs in high EGFR-expression A549 cells was 14.9-fold higher than that of PEGylated AuNPs; furthermore, uptake was also higher at 3.8-fold when MCF7 cells with lower EGFR-expression were used. MicroSPECT/CT imaging and a biodistribution study conducted by using a A549 tumor xenograft mouse model provided evidence of elevated uptake of the C225-conjugated AuNPs into the tumor cells as a result of active targeting. Moreover, the microdistribution of PEGylated AuNPs revealed that a large portion of AuNPs remained in the tumor interstitium, whereas the C225-conjugated AuNPs displayed enhanced internalization via antibody-mediated endocytosis. Our findings suggest that the anti-EGFR antibody-conjugated AuNPs are likely to be a plausible nano-sized vehicle for drug delivery to EGFR-expressing tumors.

  18. The Role of Monoclonal Antibodies in the Management of Leukemia

    Directory of Open Access Journals (Sweden)

    Mohamad Cherry

    2010-10-01

    Full Text Available This article will review the monoclonal antibodies more commonly used in leukemias. In the last three decades, scientists have made considerable progress understanding the structure and the functions of various surface antigens, such as CD20, CD33. The introduction of rituximab, an anti CD20 monoclonal antibody, had a great impact in the treatment of lymphoproliferative disorders. Gemtuzumab, an anti CD 33 conjugated monoclonal antibody has activity in acute mylegenous leukemia (AML. As this field is undergoing a rapid growth, the years will see an increasing use of monoclonal antibodies in hematological malignancies.

  19. Cambridge Healthtech Institute's 4th Annual Recombinant Antibodies Conference.

    Science.gov (United States)

    Casey, Joanne L; Coley, Andrew M

    2003-08-01

    The 4th Annual Recombinant Antibodies Conference was immediately following the 5th Annual 'Molecular Display: The Chemistry Set for Proteins and Small Molecules' conference, both held in Cambridge, MA and organised by Cambridge Healthtech Institute. The former conference focused on development of new approaches for recombinant antibody development, with particular emphasis on improved methods for selection and optimisation allowing rapid validation and development of human antibodies for the clinic. There were many impressive presentations describing emerging technologies such as new antibody-like scaffolds, covalent P2 antibody display, de-immunisation of antibodies and measuring affinities of as many as 400 clones simultaneously using proteomic microarray platforms. The conference also highlighted the latest applications of library technologies for proteomics and target discovery, and the generation of therapeutic molecules as antibodies alone or as drug, toxin or radionuclide conjugates.

  20. Antibody biotechnology

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... and automated, the hybrid cells can be stored for many years in liquid nitrogen and antibodies production is homogeneous. The hybridoma method .... they may be modified to vehicle active molecules such as radio-isotopes, toxins, cytokines, enzyme etc. In these cases, the therapeutic effect is due to ...

  1. Catalytic Antibodies

    Indian Academy of Sciences (India)

    The ability of the highly evolved machinery of immune system to produce structurally and functionally complex ... to Pauling, if the structure of the antigen binding site of antibodies were to be produced in a random ..... where the immune system of the body is destructive, as in autoimmune disorders or after organ transplant.

  2. Catalytic Antibodies

    Indian Academy of Sciences (India)

    While chemistry provides the framework for understanding the structure and function of biomolecules, the immune sys- tem provides a highly evolved natural process to generate one class of complex biomolecules – the antibodies. A combination of the two could be exploited to generate new classes of molecules with novel ...

  3. Self-Adjuvanting Glycopeptide Conjugate Vaccine against Disseminated Candidiasis

    Science.gov (United States)

    Xin, Hong; Cartmell, Jonathan; Bailey, Justin J.; Dziadek, Sebastian; Bundle, David R.; Cutler, Jim E.

    2012-01-01

    Our research on pathogenesis of disseminated candidiasis led to the discovery that antibodies specific for Candida albicans cell surface β-1, 2–mannotriose [β-(Man)3] protect mice. A 14 mer peptide Fba, which derived from the N-terminal portion of the C. albicans cytosolic/cell surface protein fructose-bisphosphate aldolase, was used as the glycan carrier and resulted in a novel synthetic glycopeptide vaccine β-(Man)3-Fba. By a dendritic cell-based immunization approach, this conjugate induced protective antibody responses against both the glycan and peptide parts of the vaccine. In this report, we modified the β-(Man)3-Fba conjugate by coupling it to tetanus toxoid (TT) in order to improve immunogenicity and allow for use of an adjuvant suitable for human use. By new immunization procedures entirely compatible with human use, the modified β-(Man)3-Fba-TT was administered either alone or as a mixture made with alum or monophosphoryl lipid A (MPL) adjuvants and given to mice by a subcutaneous (s.c.) route. Mice vaccinated with or, surprisingly, without adjuvant responded well by making robust antibody responses. The immunized groups showed a high degree of protection against a lethal challenge with C. albicans as evidenced by increased survival times and reduced kidney fungal burden as compared to control groups that received only adjuvant or DPBS buffer prior to challenge. To confirm that induced antibodies were protective, sera from mice immunized against the β-(Man)3-Fba-TT conjugate transferred protection against disseminated candidiasis to naïve mice, whereas C. albicans-absorbed immune sera did not. Similar antibody responses and protection induced by the β-(Man)3-Fba-TT vaccine was observed in inbred BALB/c and outbred Swiss Webster mice. We conclude that addition of TT to the glycopeptide conjugate results in a self-adjuvanting vaccine that promotes robust antibody responses without the need for additional adjuvant, which is novel and represents a

  4. Aptamer–Liposome Conjugates

    DEFF Research Database (Denmark)

    Ries, Oliver; Vogel, Stefan

    2016-01-01

    Aptamers, often termed as ‘chemical antibodies,’ are an emerging class of synthetic ligands for efficient target-specific molecular recognition. The objective of this book is to highlight recent advances and potential of aptamers in various disease conditions. . This book focuses...... on the applications of aptamers in targeted nanotherapy, detection, and in molecular imaging in various disease conditions such as cancer, neurological diseases and infectious diseases....

  5. Electrochromic in conjugated polymers

    International Nuclear Information System (INIS)

    Picado Valenzuela, Alfredo

    2007-01-01

    This revision considered object the description of one of the materials with the greatest potential in the field of electrochromic (mainly in the visible region): the conjugated polymers (CP), area of enormous potential both now and in a short time ahead. The CP are insulating materials and organic semiconductors in a state not doped. They can be doped positively or negatively being observed a significant increase in the conductivity and being generated a color change in these materials. The understanding of how optical properties vary based on the chemical structure of the polymer or its mixtures and more precisely of the alternatives that can be entered into the conjugated system or π system to obtain a material that besides to be flexible, environmentally stable, presents the colored states. The revision was centred chiefly in the polypyrrole (Ppy), the polythiophene (PTh) and their derivatives such as poly (3.4-ethylenedioxythiophene) (PEDOT). The advantage of using monomers with variable structure, to adjust the composition of the copolymer, or to blend with the PC, allows to obtain a variety of colored states that can be modulated through the visible spectrum and even with applications to wavelengths outside of this region. Because the PC presented at least two different colored states can be varied continuously as a function of the voltage applied. In some cases, they may submit multicoloured statements, which offers a range of possibilities for their application in flexible electronic devices type screens and windows. Applications include smart windows, camouflage clothing and data screens. This type of material is emerging as one of the substitutes of the traditional inorganic semiconductor, with the advantage of its low cost, high flexibility and the possibility to generate multiple colors through the handling of the monomers in the structure and control of energy of his band gap. (author) [es

  6. Generalized conjugate gradient squared

    Energy Technology Data Exchange (ETDEWEB)

    Fokkema, D.R.; Sleijpen, G.L.G. [Utrecht Univ. (Netherlands)

    1994-12-31

    In order to solve non-symmetric linear systems of equations, the Conjugate Gradient Squared (CGS) is a well-known and widely used iterative method. In practice the method converges fast, often twice as fast as the Bi-Conjugate Gradient method. This is what you may expect, since CGS uses the square of the BiCG polynomial. However, CGS may suffer from its erratic convergence behavior. The method may diverge or the approximate solution may be inaccurate. BiCGSTAB uses the BiCG polynomial and a product of linear factors in an attempt to smoothen the convergence. In many cases, this has proven to be very effective. Unfortunately, the convergence of BiCGSTAB may stall when a linear factor (nearly) degenerates. BiCGstab({ell}) is designed to overcome this degeneration of linear factors. It generalizes BiCGSTAB and uses both the BiCG polynomial and a product of higher order factors. Still, CGS may converge faster than BiCGSTAB or BiCGstab({ell}). So instead of using a product of linear or higher order factors, it may be worthwhile to look for other polynomials. Since the BiCG polynomial is based on a three term recursion, a natural choice would be a polynomial based on another three term recursion. Possibly, a suitable choice of recursion coefficients would result in method that converges faster or as fast as CGS, but less erratic. It turns out that an algorithm for such a method can easily be formulated. One particular choice for the recursion coefficients leads to CGS. Therefore one could call this algorithm generalized CGS. Another choice for the recursion coefficients leads to BiCGSTAB. It is therefore possible to mix linear factors and some polynomial based on a three term recursion. This way one may get the best of both worlds. The authors will report on their findings.

  7. Fingerprinting of Natural Product by Eastern Blotting Using Monoclonal Antibodies

    OpenAIRE

    Tanaka, Hiroyuki; Putalun, Waraporn; Shoyama, Yukihiro

    2012-01-01

    We succeeded in developing the fingerprint of natural product by eastern blotting using monoclonal antibodies. After developing and separating them on a TLC plate, solasodine glycosides are oxidized by NaIO4 and reacted with a protein to give conjugates which are recognized with anti-solamargine monoclonal antibody (MAb). Anti-solamargine MAb having wide cross-reactivity can stain and detect all solasodine glycosides by fingerprint. Different sensitivity between solamargine and solasonine was...

  8. A sulfhydryl-reactive ruthenium (II complex and its conjugation to protein G as a universal reagent for fluorescent immunoassays.

    Directory of Open Access Journals (Sweden)

    Jing-Tang Lin

    Full Text Available To develop a fluorescent ruthenium complex for biosensing, we synthesized a novel sulfhydryl-reactive compound, 4-bromophenanthroline bis-2,2'-dipyridine Ruthenium bis (hexafluorophosphate. The synthesized Ru(II complex was crosslinked with thiol-modified protein G to form a universal reagent for fluorescent immunoassays. The resulting Ru(II-protein G conjugates were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. The emission peak wavelength of the Ru(II-protein G conjugate was 602 nm at the excitation of 452 nm which is similar to the spectra of the Ru(II complex, indicating that Ru(II-protein G conjugates still remain the same fluorescence after conjugation. To test the usefulness of the conjugate for biosensing, immunoglobulin G (IgG binding assay was conducted. The result showed that Ru(II-protein G conjugates were capable of binding IgG and the more cross-linkers to modify protein G, the higher conjugation efficiency. To demonstrate the feasibility of Ru(II-protein G conjugates for fluorescent immunoassays, the detection of recombinant histidine-tagged protein using the conjugates and anti-histidine antibody was developed. The results showed that the histidine-tagged protein was successfully detected with dose-response, indicating that Ru(II-protein G conjugate is a useful universal fluorescent reagent for quantitative immunoassays.

  9. Antibody proteases: induction of catalytic response.

    Science.gov (United States)

    Gabibov, A G; Friboulet, A; Thomas, D; Demin, A V; Ponomarenko, N A; Vorobiev, I I; Pillet, D; Paon, M; Alexandrova, E S; Telegin, G B; Reshetnyak, A V; Grigorieva, O V; Gnuchev, N V; Malishkin, K A; Genkin, D D

    2002-10-01

    Most of the data accumulated throughout the years on investigation of catalytic antibodies indicate that their production increases on the background of autoimmune abnormalities. The different approaches to induction of catalytic response toward recombinant gp120 HIV-1 surface protein in mice with various autoimmune pathologies are described. The peptidylphosphonate conjugate containing structural part of gp120 molecule is used for reactive immunization of NZB/NZW F1, MRL, and SJL mice. The specific modification of heavy and light chains of mouse autoantibodies with Val-Ala-Glu-Glu-Glu-Val-PO(OPh)2 reactive peptide was demonstrated. Increased proteolytic activity of polyclonal antibodies in SJL mice encouraged us to investigate the production of antigen-specific catalytic antibodies on the background of induced experimental autoimmune encephalomyelitis (EAE). The immunization of autoimmune-prone mice with the engineered fusions containing the fragments of gp120 and encephalitogenic epitope of myelin basic protein (MBP(89-104)) was made. The proteolytic activity of polyclonal antibodies isolated from the sera of autoimmune mice immunized by the described antigen was shown. Specific immune response of SJL mice to these antigens was characterized. Polyclonal antibodies purified from sera of the immunized animals revealed proteolytic activity. The antiidiotypic approach to raise the specific proteolytic antibody as an "internal image" of protease is described. The "second order" monoclonal antibodies toward subtilisin Carlsberg revealed pronounced proteolytic activity.

  10. Reciprocity and conjugation fidelity in double phase conjugate mirrors

    Science.gov (United States)

    Delaye, Philippe; Fotiadi, Andrei A.; Roosen, Gerald

    1999-09-01

    It is well known that the conservation of energy in an optical system can be described by an invariant (intensity of the optical wave) during propagation. We identically show that reciprocity can be described by an invariant. This invariant is the overlap integral of two counterpropagating waves, that stays constant in every place of a reciprocal optical system. Applied to the double phase conjugate mirror (DPCM) this invariant can be rewritten as an equality between the ratio of the conjugation fidelity of the two ports of the DPCM and the ratio of the transmission in intensity of the two beams. If restricted to a plane wave case this relation becomes the well known equality of the diffraction efficiencies in both directions. We have implemented an experimental set-up that allows to show that the double phase conjugate mirror is reciprocal what confirms all the above discussion. We use the same set-up to measure the conjugation fidelity of the DPCM.

  11. Antibody-guided photoablation of voltage-gated potassium currents

    Science.gov (United States)

    Stephanopoulos, Nicholas; Austin, Daniel C.; Francis, Matthew B.; Trimmer, James S.

    2013-01-01

    A family of 40 mammalian voltage-gated potassium (Kv) channels control membrane excitability in electrically excitable cells. The contribution of individual Kv channel types to electrophysiological signaling has been difficult to assign, as few selective inhibitors exist for individual Kv subunits. Guided by the exquisite selectivity of immune system interactions, we find potential for antibody conjugates as selective Kv inhibitors. Here, functionally benign anti-Kv channel monoclonal antibodies (mAbs) were chemically modified to facilitate photoablation of K currents. Antibodies were conjugated to porphyrin compounds that upon photostimulation inflict localized oxidative damage. Anti-Kv4.2 mAb–porphyrin conjugates facilitated photoablation of Kv4.2 currents. The degree of K current ablation was dependent on photon dose and conjugate concentration. Kv channel photoablation was selective for Kv4.2 over Kv4.3 or Kv2.1, yielding specificity not present in existing neurotoxins or other Kv channel inhibitors. We conclude that antibody–porphyrin conjugates are capable of selective photoablation of Kv currents. These findings demonstrate that subtype-specific mAbs that in themselves do not modulate ion channel function are capable of delivering functional payloads to specific ion channel targets. PMID:23940262

  12. A VAR2CSA:CSP conjugate capable of inducing dual specificity ...

    African Journals Online (AJOL)

    A VAR2CSA:CSP conjugate capable of inducing dual specificity antibody responses. Matondo Sungwa1, Thrane Susan2, Janitzek Christoph Mikkel2, Kavishe Reginald Adolph1,. Mwakalinga Steven Boniface1, Theander Thor Grundtvig2, Salanti Ali2,. Nielsen Morten Agertoug2, Sander Adam Frederik2. 1. Kilimanjaro ...

  13. Enhanced control of Mycobacterium tuberculosis extrapulmonary dissemination in mice by an arabinomannan-protein conjugate vaccine.

    Directory of Open Access Journals (Sweden)

    Rafael Prados-Rosales

    2017-03-01

    Full Text Available Currently there are a dozen or so of new vaccine candidates in clinical trials for prevention of tuberculosis (TB and each formulation attempts to elicit protection by enhancement of cell-mediated immunity (CMI. In contrast, most approved vaccines against other bacterial pathogens are believed to mediate protection by eliciting antibody responses. However, it has been difficult to apply this formula to TB because of the difficulty in reliably eliciting protective antibodies. Here, we developed capsular polysaccharide conjugates by linking mycobacterial capsular arabinomannan (AM to either Mtb Ag85b or B. anthracis protective antigen (PA. Further, we studied their immunogenicity by ELISA and AM glycan microarrays and protection efficacy in mice. Immunization with either Abg85b-AM or PA-AM conjugates elicited an AM-specific antibody response in mice. AM binding antibodies stimulated transcriptional changes in Mtb. Sera from AM conjugate immunized mice reacted against a broad spectrum of AM structural variants and specifically recognized arabinan fragments. Conjugate vaccine immunized mice infected with Mtb had lower bacterial numbers in lungs and spleen, and lived longer than control mice. These findings provide additional evidence that humoral immunity can contribute to protection against Mtb.

  14. Development and Characterization of a Camelid Single Domain Antibody–Urease Conjugate That Targets Vascular Endothelial Growth Factor Receptor 2

    Directory of Open Access Journals (Sweden)

    Baomin Tian

    2017-08-01

    Full Text Available Angiogenesis is the process of new blood vessel formation and is essential for a tumor to grow beyond a certain size. Tumors secrete the pro-angiogenic factor vascular endothelial growth factor, which acts upon local endothelial cells by binding to vascular endothelial growth factor receptors (VEGFRs. In this study, we describe the development and characterization of V21-DOS47, an immunoconjugate that targets VEGFR2. V21-DOS47 is composed of a camelid single domain anti-VEGFR2 antibody (V21 and the enzyme urease. The conjugate specifically binds to VEGFR2 and urease converts endogenous urea into ammonia, which is toxic to tumor cells. Previously, we developed a similar antibody–urease conjugate, L-DOS47, which is currently in clinical trials for non-small cell lung cancer. Although V21-DOS47 was designed from parameters learned from the generation of L-DOS47, additional optimization was required to produce V21-DOS47. In this study, we describe the expression and purification of two versions of the V21 antibody: V21H1 and V21H4. Each was conjugated to urease using a different chemical cross-linker. The conjugates were characterized by a panel of analytical techniques, including SDS-PAGE, size exclusion chromatography, Western blotting, and LC-MSE peptide mapping. Binding characteristics were determined by ELISA and flow cytometry assays. To improve the stability of the conjugates at physiologic pH, the pIs of the V21 antibodies were adjusted by adding several amino acid residues to the C-terminus. For V21H4, a terminal cysteine was also added for use in the conjugation chemistry. The modified V21 antibodies were expressed in the E. coli BL21 (DE3 pT7 system. V21H1 was conjugated to urease using the heterobifunctional cross-linker succinimidyl-[(N-maleimidopropionamido-diethyleneglycol] ester (SM(PEG2, which targets lysine resides in the antibody. V21H4 was conjugated to urease using the homobifunctional cross-linker, 1,8-bis

  15. Production and purification of polyclonal antibody against bovine ...

    African Journals Online (AJOL)

    Antibodies are important tools in medical researches which have led to many advances in this field. Anti-bovine immunoglobulins and its conjugate with horse radish peroxidase (HRP) is used to diagnose cows' disease by ELISA or western blotting tests. In this study, the production, purification and horse radish peroxidase ...

  16. Specific targeting of tumor cells by lyophilisomes functionalized with antibodies

    NARCIS (Netherlands)

    van Bracht, Etienne; Stolle, Sarah; Hafmans, Theo G.; Boerman, Otto C.; Oosterwijk, Egbert; van Kuppevelt, Toin H.; Daamen, Willeke F.

    Lyophilisomes are a novel class of proteinaceous biodegradable nano/micro drug delivery capsules prepared by freezing, annealing and Iyophilization. In the present study, lyophilisomes were functionalized for active targeting by antibody conjugation in order to obtain a selective drug-carrier

  17. Production and purification of polyclonal antibody against bovine ...

    African Journals Online (AJOL)

    SERVER

    2007-06-18

    Jun 18, 2007 ... that ion-exchange chromatography could be an appropriate method for purification of IgG antibodies. Key words: Anti bovine immunoglobulins, horse radish peroxidase conjugation, ion-exchange chromatography, polyclonal ... diagnostic and therapeutic applications (Gallacher, 1993;. Gathumbi et al.

  18. Monoclonal antibodies specific for the organophosphate pesticide azinphos-methyl

    NARCIS (Netherlands)

    Jones, WT; Harvey, D; Jones, SD; Ryan, GB; Wynberg, H; TenHoeve, W; Reynolds, PHS

    1995-01-01

    2-(2-Mercapto-5-methyl-1,3,2-dioxaphosphorinan-5-yl,2-sulphide) methoxyacetic acid has been synthesized and used to prepare an azinphos hapten and protein conjugates. Monoclonal antibodies of high affinity against the pesticide azinphos-methyl were prepared from mice immunized with the

  19. Egg Yolk Antibodies (IgY) in Routine Diagnostic Work.

    Science.gov (United States)

    Staak, Christian

    1996-01-01

    According to Linscott"s Directory of Immunological and Biological Reagents (1994/95) the commercial availability of egg-yolk antibodies (IgY) is extremely low. For preparation, cleaning and detection of IgY it would be of advantage to have a "Protein Y" available analogous to protein A and protein G for mammalian antibodies. Until now, the search for "Protein Y" was unsuccessful. IgY has been used for routine diagnostic work covering the following subjects: 1.Identification of the host species from abdominal blood of haematophageous insects; 2.IgY-anti-horse-Ig-PO conjugate for ELISA on dourine; 3.FITC-conjugated IgY-antirabies for diagnostic work on rabies; 4.FITC-conjugated IgY against avian virus diseases (Newcastle dis., Infectious bronchitis, Gumboro). In all cases satisfactory results have been achieved.

  20. Sequential measurements of conjugate observables

    Energy Technology Data Exchange (ETDEWEB)

    Carmeli, Claudio [Dipartimento di Fisica, Universita di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Heinosaari, Teiko [Department of Physics and Astronomy, Turku Centre for Quantum Physics, University of Turku, 20014 Turku (Finland); Toigo, Alessandro, E-mail: claudio.carmeli@gmail.com, E-mail: teiko.heinosaari@utu.fi, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica ' Francesco Brioschi' , Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2011-07-15

    We present a unified treatment of sequential measurements of two conjugate observables. Our approach is to derive a mathematical structure theorem for all the relevant covariant instruments. As a consequence of this result, we show that every Weyl-Heisenberg covariant observable can be implemented as a sequential measurement of two conjugate observables. This method is applicable both in finite- and infinite-dimensional Hilbert spaces, therefore covering sequential spin component measurements as well as position-momentum sequential measurements.

  1. The development and applications of polyclonal and monoclonal antibodies for the detection of illicit drugs in saliva samples

    OpenAIRE

    Fanning, Lorna M.

    2002-01-01

    Anti-tetrahydrocannabinol (THC), anti-cocaine and anti-morphine polyclonal antibodies were produced. These antibodies were successfully applied to an ELISA format for the detection of THC, cocaine, and morphine in saliva samples. Monoclonal antibodies against amphetamine and its derivatives were produced using two different conjugates, amphetamine-bovine serum albumin and methamphetaminebovine serum albumin. Two successful clones were produced, and the antibodies were applied to an ELISA ...

  2. Effect of increased CRM₁₉₇ carrier protein dose on meningococcal C bactericidal antibody response.

    Science.gov (United States)

    Lee, Lucia H; Blake, Milan S

    2012-04-01

    New multivalent CRM(197)-based conjugate vaccines are available for childhood immunization. Clinical studies were reviewed to assess meningococcal group C (MenC) antibody responses following MenC-CRM(197) coadministration with CRM(197)-based pneumococcal or Haemophilus influenzae type b conjugate vaccines. Infants receiving a total CRM(197) carrier protein dose of ∼50 μg and concomitant diphtheria-tetanus-acellular pertussis (DTaP)-containing vaccine tended to have lower MenC geometric mean antibody titers and continued to have low titers after the toddler dose. Nevertheless, at least 95% of children in the reported studies achieved a MenC serum bactericidal antibody (SBA) titer of ≥ 1:8 after the last infant or toddler dose. SBA was measured using an assay with a baby rabbit or human complement source. Additional studies are needed to assess long-term antibody persistence and MenC CRM(197) conjugate vaccine immunogenicity using alternative dosing schedules.

  3. A Polar Sulfamide Spacer Significantly Enhances the Manufacturability, Stability, and Therapeutic Index of Antibody–Drug Conjugates

    OpenAIRE

    Jorge M. M. Verkade; Marloes A. Wijdeven; Remon van Geel; Brian M. G. Janssen; Sander S. van Berkel; Floris L. van Delft

    2018-01-01

    Despite tremendous efforts in the field of targeted cancer therapy with antibody–drug conjugates (ADCs), attrition rates have been high. Historically, the priority in ADC development has been the selection of target, antibody, and toxin, with little focus on the nature of the linker. We show here that a short and polar sulfamide spacer (HydraSpace™, AE Oss, The Netherland) positively impacts ADC properties in various ways: (a) efficiency of conjugation; (b) stability; and (c) therapeutic inde...

  4. A Fast and Sensitive Quantitative Lateral Flow Immunoassay for Cry1Ab Based on a Novel Signal Amplification Conjugate

    OpenAIRE

    Chen, Chunxiang; Wu, Jian

    2012-01-01

    A novel lateral flow immunoassay (LFIA) signal amplification strategy for the detection of Cry1Ab based on amplification via a polylysine (PL) chain and biotin-streptavidin system (BSAS) is described. In this system, multiple fluorescence dyes (FL) were directly coated on the surface of PL and conjugated with antibody via the BSAS for construction of novel signal amplification (FLPL-BSAS-mAb1) conjugates, in which FL, PL and BSAS were employed to improve the sensitivity of LFIA. Compared with...

  5. Structural correlates of carrier protein recognition in tetanus toxoid-conjugated bacterial polysaccharide vaccines.

    Science.gov (United States)

    Lockyer, Kay; Gao, Fang; Derrick, Jeremy P; Bolgiano, Barbara

    2015-03-10

    An analysis of structure-antibody recognition relationships in nine licenced polysaccharide-tetanus toxoid (TT) conjugate vaccines was performed. The panel of conjugates used included vaccine components to protect against disease caused by Haemophilus influenzae type b, Neisseria meningitidis groups A, C, W and Y and Streptococcus pneumoniae serotype 18C. Conformation and structural analysis included size exclusion chromatography with multi-angle light scattering to determine size, and intrinsic fluorescence spectroscopy and fluorescence quenching to evaluate the protein folding and exposure of Trp residues. A capture ELISA measured the recognition of TT epitopes in the conjugates, using four rat monoclonal antibodies: 2 localised to the HC domain, and 2 of which were holotoxoid conformation-dependent. The conjugates had a wide range of average molecular masses ranging from 1.8×10(6) g/mol to larger than 20×10(6) g/mol. The panel of conjugates were found to be well folded, and did not have spectral features typical of aggregated TT. A partial correlation was found between molecular mass and epitope recognition. Recognition of the epitopes either on the HC domain or the whole toxoid was not necessarily hampered by the size of the molecule. Correlation was also found between the accessibility of Trp side chains and polysaccharide loading, suggesting also that a higher level of conjugated PS does not necessarily interfere with toxoid accessibility. There were different levels of carrier protein Trp side-chain and epitope accessibility that were localised to the HC domain; these were related to the saccharide type, despite the conjugates being independently manufactured. These findings extend our understanding of the molecular basis for carrier protein recognition in TT conjugate vaccines. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  6. Conjugated Fatty Acid Synthesis

    Science.gov (United States)

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 Δ9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ9cis,11trans,13cis) or α-eleostearic acid (18:3 Δ9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  7. Functional improvements to beta-lactoglobulin by preparing an edible conjugate with cationic saccharide using microbial transglutaminase [corrected] (MTGase).

    Science.gov (United States)

    Ikeuchi, Tomomi; Aoki, Tomomi; Yoshida, Tadashi; Takahashi, Koji; Hattori, Makoto

    2008-05-01

    Bovine beta-lactoglobulin (BLG) was conjugated with cationic saccharides to improve its functions. We used a polylysine-dextran conjugate (PL-Dex) as the cationic saccharide which had been prepared by the Maillard reaction. The molar ratio of PL:Dex was 1:1. The emulsifying property of PL in the acidic pH range was improved by conjugating with Dex. BLG and PL-Dex were conjugated by using microbial transglutaminase (MTGase), the effective conjugation being confirmed by SDS-PAGE. The molar ratio of BLG:PL-Dex was 1:1. Structural analyses by a fluorescence study, ELISA with monoclonal antibodies and measurement of the retinol-binding activity indicated that the conjugates had almost retained the native structure of BLG. The emulsifying property of BLG in the acidic pH range and in the presence of NaCl was improved by conjugating with PL-Dex. The immunogenicity of BLG was reduced by this conjugation, while the antigenicity of the BLG-PL-Dex conjugate was similar to that of BLG in BALB/c mice.

  8. Update on the use of meningococcal serogroup C CRM₁₉₇-conjugate vaccine (Meningitec) against meningitis.

    Science.gov (United States)

    Badahdah, Al-Mamoon; Rashid, Harunor; Khatami, Ameneh

    2016-01-01

    Meningitec is a CRM197-conjugated meningococcal serogroup C (MenC) vaccine, first licensed in 1999. It has been used as a primary and booster vaccine in infants, toddlers, older children and adults, and has been shown to be immunogenic and well-tolerated in all age groups, including premature infants. Vaccine effectiveness has been demonstrated using combined data on all three licensed MenC conjugate vaccines. Evidence from clinical trials, however, suggests that the different MenC conjugate vaccines behave differently with respect to the induction and persistence of bactericidal antibody and generation of immune memory. It appears that Meningitec has a less favorable immunologic profile compared particularly to tetanus toxoid (TT) MenC conjugate vaccines. Data from comparative trials have raised interesting questions on priming of the immune system by conjugate vaccines, particularly in infants. The results from these and other studies are reviewed here with specific focus on Meningitec.

  9. Lysine conjugation properties in human IgGs studied by integrating high-resolution native mass spectrometry and bottom-up proteomics

    NARCIS (Netherlands)

    Gautier, Violette; Boumeester, Anja J.; Lössl, Philip; Heck, Albert J R

    2015-01-01

    Antibody-drug conjugates (ADCs) are a novel class of biopharmaceuticals several of which are now being investigated in clinical studies. In ADCs, potent cytotoxic drugs are coupled via a linker to reactive residues in IgG monoclonal antibodies. Linkage to lysine residues in the IgGs, using

  10. Research study of conjugate materials; Conjugate material no chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper reported an introductory research on possibilities of new glass `conjugate materials.` The report took up the structure and synthetic process of conjugate materials to be researched/developed, classified them according to structural elements on molecular, nanometer and cluster levels, and introduced the structures and functions. Further, as glasses with new functions to be proposed, the paper introduced transparent and high-strength glass used for houses and vehicles, light modulation glass which realizes energy saving and optical data processing, and environmentally functional glass which realizes environmental cleaning or high performance biosensor. An initial survey was also conducted on rights of intellectual property to be taken notice of in Japan and abroad in the present situation. Reports were summed up and introduced of Osaka National Research Institute, Electrotechnical Laboratory, and National Industrial Research Institute of Nagoya which are all carrying out leading studies of conjugate materials. 235 refs., 135 figs., 6 tabs.

  11. Inhibition of mannosidase in hybridomas yields monoclonal antibodies with greater capacity for carbohydrate labeling

    International Nuclear Information System (INIS)

    Simonson, R.B.; Ultee, M.E.; Long, C.G.; Gillette, R.W.; McKearn, T.J.; Rodwell, J.D.

    1988-01-01

    Labeling an antibody site specifically through its carbohydrate residues preserves more of its antigen-binding activity than does labeling through protein moieties. To boost the amount of immunoglobulin G carbohydrate capable of being labeled, we treated hybridoma cells with a mannosidase inhibitor, deoxymannojirimycin (dMM). Polyacrylamide gel electrophoresis showed formation of a glycoprotein with high mannose content, in that endo-beta-N-acetylglucosaminidase H 3.2.1.96) could digest the antibody from the dMM-treated cells, but not from control cultures. Carbohydrate analysis confirmed this conclusion, indicating that the antibody from the dMM-treated cells had twice as much mannose as did the control antibody. The glucosamine content of the treated-cells' antibodies was half that of the control, and no additional carbohydrate residues were detectable in the antibodies secreted by the dMM-treated cells. We conjugated both the dMM and control antibodies through their carbohydrate to a chelator. In labeling, the dMM antibody conjugate incorporated approximately threefold as much 111 In isotope as the control conjugate. The two labeled antibodies were injected into mice and showed similar organ distributions

  12. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  13. Persistence Mechanisms of Conjugative Plasmids

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    maintenance in the host cell. These importantly include the ability to self-mobilize in a process termed conjugative transfer, which may occur across species barriers. Other plasmid stabilizing mechanisms include the multimer resolution system, active partitioning, and post-segregational-killing of plasmid......Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting...... the successful propagation and long-term continued existence of these extra-chromosomal elements is extensive. Apart from the accessory genetic elements that may provide plasmid-harboring cells a selective advantage, special focus is placed on the mechanisms conjugative plasmids employ to ensure their stable...

  14. Molecular Cloning, Expression and Peroxidase Conjugation of Staphylococcus aureus Protein A

    Science.gov (United States)

    Seyfi Abad Shapouri, Masoud Reza; Mahmoodi, Pezhman; Gharibi, Dariush; Ghorbanpoor, Masoud; Yaghoubi, Sara; Rezaei, Elham; Rashno, Mohammad; Mehravar, Neda

    2016-01-01

    Background Staphylococcal protein A (SPA) is a cell wall component of Staphylococcus aureus that binds to different IgG subclasses of human and several animal species. This bacterial protein can be used as an antibody detector in various immunological assays or as an isolation reagent for the purification of antibody molecules via immuno-chromatography procedures. Objectives Molecular cloning and expression of SPA followed by the purification and conjugation of the recombinant protein to peroxidase enzyme. Material and Methods Encoding DNA fragment of SPA was amplified and inserted into a prokaryotic plasmid vector for the expression of recombinant SPA fused to a maltose binding protein (MBP). The recombinant protein was purified using amylose resin column chromatography and conjugated to horseradish peroxidase (HRP) enzyme. Finally, the reactivity of the recombinant SPA was examined against human IgG molecules in ELISA. Results The results indicated that the recombinant peroxidase-conjugated SPA has a good recognition capacity for human IgG molecules and it was able to produce significant OD values after reacting with human IgG molecules at a concentration up to 0.06 μg.well-1. Conclusions This recombinant protein can be very useful in all research laboratories and may decrease some of the expenses, e.g. those for preparing conjugated anti-antibodies. PMID:28959340

  15. Phase conjugation of acoustic beams

    Science.gov (United States)

    Bunkin, F. V.; Vlasov, D. V.; Kravtsov, Iu. A.

    The paper presents a classification of methods for the phase conjugation (PC) of wave fields of various physical natures on the basis of such nonliner interactions as stimulated scattering, and three- and four-wave interactions. Among the latter, attention is given to holographic (volume and surface) and parametric PC schemes, permitting PC with amplification. The possibility of developing phase-conjugated devices using acoustic PC devices on the basis of various nonlinear effects is considered. Experimental results pertaining to the PC of sound fields are presented, and possible applications of acoustic PC devices are indicated.

  16. Prescreening of Nicotine Hapten Linkers in Vitro To Select Hapten-Conjugate Vaccine Candidates for Pharmacokinetic Evaluation in Vivo.

    Science.gov (United States)

    Arutla, Viswanath; Leal, Joseph; Liu, Xiaowei; Sokalingam, Sriram; Raleigh, Michael; Adaralegbe, Adejimi; Liu, Li; Pentel, Paul R; Hecht, Sidney M; Chang, Yung

    2017-05-08

    Since the demonstration of nicotine vaccines as a possible therapeutic intervention for the effects of tobacco smoke, extensive effort has been made to enhance nicotine specific immunity. Linker modifications of nicotine haptens have been a focal point for improving the immunogenicity of nicotine, in which the evaluation of these modifications usually relies on in vivo animal models, such as mice, rats or nonhuman primates. Here, we present two in vitro screening strategies to estimate and predict the immunogenic potential of our newly designed nicotine haptens. One utilizes a competition enzyme-linked immunoabsorbent assay (ELISA) to profile the interactions of nicotine haptens or hapten-protein conjugates with nicotine specific antibodies, both polyclonal and monoclonal. Another relies on computational modeling of the interactions between haptens and amino acid residues near the conjugation site of the carrier protein to infer linker-carrier protein conjugation effect on antinicotine antibody response. Using these two in vitro methods, we ranked the haptens with different linkers for their potential as viable vaccine candidates. The ELISA-based hapten ranking was in an agreement with the results obtained by in vivo nicotine pharmacokinetic analysis. A correlation was found between the average binding affinity (IC 50 ) of the haptens to an anti-Nic monoclonal antibody and the average brain nicotine concentration in the immunized mice. The computational modeling of hapten and carrier protein interactions helps exclude conjugates with strong linker-carrier conjugation effects and low in vivo efficacy. The simplicity of these in vitro screening strategies should facilitate the selection and development of more effective nicotine conjugate vaccines. In addition, these data highlight a previously under-appreciated contribution of linkers and hapten-protein conjugations to conjugate vaccine immunogenicity by virtue of their inclusion in the epitope that binds and

  17. High pressure structural studies of conjugated molecules

    DEFF Research Database (Denmark)

    Knaapila, Matti; Torkkeli, Mika; Scherf, Ullrich

    2018-01-01

    This chapter highlights high pressure GPa level structural studies of conjugated polymers and their analogues: conjugated oligomers and molecules, and rigid rod polymers. Attention is placed on our recent studies of polyfluorenes.......This chapter highlights high pressure GPa level structural studies of conjugated polymers and their analogues: conjugated oligomers and molecules, and rigid rod polymers. Attention is placed on our recent studies of polyfluorenes....

  18. Enhanced photophysics of conjugated polymers

    Science.gov (United States)

    Chen, Liaohai [Darien, IL

    2007-06-12

    A particulate fluorescent conjugated polymer surfactant complex and method of making and using same. The particles are between about 15 and about 50 nm and when formed from a lipsome surfactant have a charge density similar to DNA and are strongly absorbed by cancer cells.

  19. Conjugal Pairing in Escherichia Coli

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  20. Galois conjugates of topological phases

    Science.gov (United States)

    Freedman, M. H.; Gukelberger, J.; Hastings, M. B.; Trebst, S.; Troyer, M.; Wang, Z.

    2012-01-01

    Galois conjugation relates unitary conformal field theories and topological quantum field theories (TQFTs) to their nonunitary counterparts. Here we investigate Galois conjugates of quantum double models, such as the Levin-Wen model. While these Galois-conjugated Hamiltonians are typically non-Hermitian, we find that their ground-state wave functions still obey a generalized version of the usual code property (local operators do not act on the ground-state manifold) and hence enjoy a generalized topological protection. The key question addressed in this paper is whether such nonunitary topological phases can also appear as the ground states of Hermitian Hamiltonians. Specific attempts at constructing Hermitian Hamiltonians with these ground states lead to a loss of the code property and topological protection of the degenerate ground states. Beyond this, we rigorously prove that no local change of basis can transform the ground states of the Galois-conjugated doubled Fibonacci theory into the ground states of a topological model whose Hermitian Hamiltonian satisfies Lieb-Robinson bounds. These include all gapped local or quasilocal Hamiltonians. A similar statement holds for many other nonunitary TQFTs. One consequence is that these nonunitary TQFTs do not describe physical realizations of topological phases. In particular, this implies that the “Gaffnian” wave function can not be the ground state of a gapped fractional quantum Hall state.

  1. Conjugal Pairing in Escherichia Coli

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  2. Bacteriophytochromes control conjugation in Agrobacterium fabrum.

    Science.gov (United States)

    Bai, Yingnan; Rottwinkel, Gregor; Feng, Juan; Liu, Yiyao; Lamparter, Tilman

    2016-08-01

    Bacterial conjugation, the transfer of single stranded plasmid DNA from donor to recipient cell, is mediated through the type IV secretion system. We performed conjugation assays using a transmissible artificial plasmid as reporter. With this assay, conjugation in Agrobacterium fabrum was modulated by the phytochromes Agp1 and Agp2, photoreceptors that are most sensitive in the red region of visible light. In conjugation studies with wild-type donor cells carrying a pBIN-GUSINT plasmid as reporter that lacked the Ti (tumor inducing) plasmid, no conjugation was observed. When either agp1(-) or agp2(-) knockout donor strains were used, plasmid DNA was delivered to the recipient, indicating that both phytochromes suppress conjugation in the wild type donor. In the recipient strains, the loss of Agp1 or Agp2 led to diminished conjugation. When wild type cells with Ti plasmid and pBIN-GUS reporter plasmid were used as donor, a high rate of conjugation was observed. The DNA transfer was down regulated by red or far-red light by a factor of 3.5. With agp1(-) or agp2(-) knockout donor cells, conjugation in the dark was about 10 times lower than with the wild type donor, and with the double knockout donor no conjugation was observed. These results imply that the phytochrome system has evolved to inhibit conjugation in the light. The decrease of conjugation under different temperature correlated with the decrease of phytochrome autophosphorylation. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy ...

    African Journals Online (AJOL)

    REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy. AOK Johnson. Abstract. Conjugated hyperbilirubinaemia exists when the conjugated serum bilirubin level is more than 2 mg/dl or more than 20 per cent of the total serum bilirubin. It is always pathological in early infancy. The causes are many and diverse ...

  4. Cellular response of ovarian carcinoma cells to antibody-photosensitizer-mediated injury

    Science.gov (United States)

    Hasan, Tayyaba; Sherwood, M. E.; Anderson, T.; Bamberg, Mike; Flotte, Thomas J.; Zurawski, Vince R., Jr.

    1990-07-01

    An anti-ovarian carcinoma antibody OC125 was conjugated to a derivative of the photosensitizer (PS) chiorin e6 yj polyglutamic acid. Target cells from a human ovarian cancer cell line were treated with this conjugate and laser irradiation at 656 rim (absorption maximum of PS) and fixed 24 h later for electron microscopy. Electron niicrographs showed a high degree of vacoulization, generalized cell necrosis, and extrusion of organelles. No specific damage to the plasma membrane was noted. Untreated control cells, or cells treated with conjugate or light alone exhibited no injury. These data suggest that even though the antibody recognizes a cell surface antigen, the conjugate is internalized under the conditions of the experiment.

  5. Macrophages are critical effectors of antibody therapies for cancer.

    Science.gov (United States)

    Weiskopf, Kipp; Weissman, Irving L

    2015-01-01

    Macrophages are innate immune cells that derive from circulating monocytes, reside in all tissues, and participate in many states of pathology. Macrophages play a dichotomous role in cancer, where they promote tumor growth but also serve as critical immune effectors of therapeutic antibodies. Macrophages express all classes of Fcγ receptors, and they have immense potential to destroy tumors via the process of antibody-dependent phagocytosis. A number of studies have demonstrated that macrophage phagocytosis is a major mechanism of action of many antibodies approved to treat cancer. Consequently, a number of approaches to augment macrophage responses to therapeutic antibodies are under investigation, including the exploration of new targets and development of antibodies with enhanced functions. For example, the interaction of CD47 with signal-regulatory protein α (SIRPα) serves as a myeloid-specific immune checkpoint that limits the response of macrophages to antibody therapies, and CD47-blocking agents overcome this barrier to augment phagocytosis. The response of macrophages to antibody therapies can also be enhanced with engineered Fc variants, bispecific antibodies, or antibody-drug conjugates. Macrophages have demonstrated success as effectors of cancer immunotherapy, and further investigation will unlock their full potential for the benefit of patients.

  6. Intranasal immunization of the combined lipooligosaccharide conjugates protects mice from the challenges with three serotypes of Moraxella catarrhalis.

    Directory of Open Access Journals (Sweden)

    Dabin Ren

    Full Text Available There are no licensed vaccines available against Moraxella catarrhalis, a significant human respiratory pathogen. Lipooligosaccharide (LOS based conjugate vaccines derived from individual serotype M. catarrhalis only showed partial protection coverage. A vaccine combining LOS conjugates of two or three serotypes might provide a broader protection.Mice were immunized intranasally with the combined conjugates consisting of LOS from serotype A and B or serotype A, B, and C followed by challenge with different M. catarrhalis strains of three serotypes. Mouse lungs, nasal washes, and sera were collected after each challenge for bacterial counts, histological evaluation, cytokine profiles, antibody level and binding activity determinations.Intranasal administration of the combined LOS conjugates not only enhanced pulmonary bacterial clearance of all three serotypes of M. catarrhalis strains in vaccinated mice, but also elevated serotype-specific anti-LOS immunoglobulin (IgA and IgG titers in nasal wash and serum respectively. Mice vaccinated with the combined LOS conjugates also showed increased interferon (IFN-γ, interleukin (IL-12, and IL-4 in the lungs after challenges. Compared to the control group, mice immunized with the combined LOS conjugates also showed reduced lung inflammation after M. catarrhalis infections. The hyperimmune sera induced by the combined conjugates exhibited a broad cross-reactivity toward all three serotypes of M. catarrhalis under transmission electron microscopy.The combined vaccine of serotype A and B LOS conjugates provides protection against most M. catarrhalis strains by eliciting humoral and cellular immune responses.

  7. Antibody-directed targeting of lysostaphin adsorbed onto polylactide nanoparticles increases its antimicrobial activity against S. aureus in vitro

    International Nuclear Information System (INIS)

    Satishkumar, R; Vertegel, A A

    2011-01-01

    The objective of this paper was to study the effect of antibody-directed targeting of S. aureus by comparing the activities of lysostaphin conjugated to biodegradable polylactide nanoparticles (NPs) in the presence and in the absence of co-immobilized anti-S. aureus antibody. Lysostaphin–antibody–NP conjugates were synthesized through physical adsorption at different enzyme:antibody:NP ratios. The synthesized enzyme–NP conjugates were characterized by means of dynamic light scattering and zeta potential analysis, and the total protein binding yield on the NPs was characterized using Alexa Fluor 350 and 594 dyes for the S. aureus antibody and lysostaphin respectively. We observed enhanced antimicrobial activity for both enzyme-coated and enzyme–antibody-coated NPs for lysostaphin coatings corresponding to ∼ 40% of the initial monolayer and higher compared to the free enzyme case (p < 0.05). At the highest antibody coating concentration, bacterial lysis rates for antibody-coated samples were significantly higher than for lysostaphin-coated samples lacking the antibody (p < 0.05). Such enzyme–NP conjugates thus have the potential for becoming novel therapeutic agents for treating antibiotic-resistant S. aureus infections.

  8. A physics-explicit model of bacterial conjugation shows the stabilizing role of the conjugative junction

    OpenAIRE

    Pastuszak, Jakub; Waclaw, Bartlomiej

    2017-01-01

    Conjugation is a process in which bacteria exchange DNA through a physical connection (conjugative junction) between mating cells. Despite its significance for processes such as the spread of antibiotic resistance, the role of physical forces in conjugation is poorly understood. Here we use computer models to show that the conjugative junction not only serves as a link to transfer the DNA but it also mechanically stabilises the mating pair which significantly increases the conjugation rate. W...

  9. The production and characterisation of an antibody to detect the coccidiostat toltrazuril and its metabolite ponazuril.

    OpenAIRE

    Connolly, Lisa; Fodey, T.L.; Elliott, Christopher; Crooks, S.R.H.

    2003-01-01

    The production of an antibody to detect toltrazuril or its metabolite ponazuril is complicated due to structural constraints of conjugating these coccidiostats to a carrier protein. Therefore a search was carried out for a compound that shared a common substructure to use as an antigen mimic. The chosen compound, trifluoraminoether, was conjugated to two carrier proteins (HSA and BTG) and used in the immunisation of six rabbits. Two immunogen doses (1 mg and 0.1 mg) were also used. All six ra...

  10. Quantum dot-based western blot for sensitive detection of pig serum antibody to actinobacillus pleuropneumoniae

    Science.gov (United States)

    Cişmileanu, Ana; Sima, Cornelia; Grigoriu, Constantin

    2007-08-01

    A quantum dot - immunoglobulin conjugate specific for pig IgG, was obtained by carbodiimide chemistry. We used a Western blot technique for detecting specific antibodies against Actinobacillus pleuropneumoniae (A. pp), which cause porcine pleuropneumonia. The antigen used in this technique was Apx haemolysin which is an important virulence factor of A. pp and it induces protective immunity in vaccined pigs. The detection on Western blot membrane was possible at 1/50 dilution of quantum dot conjugate at a dilution of pig serum till 1/6400. The results for pig serum demonstrated a higher sensitivity of QD-based Western blot technique for the presence of antibodies specific for Apx haemolysin in comparison with similar classical techniques (with coloured substrate for enzyme present in secondary antibody conjugate).

  11. TAT Peptide and Its Conjugates: Proteolytic Stability

    OpenAIRE

    Grunwald, Jacob; Rejtar, Tomas; Sawant, Rupa; Wang, Zhouxi; Torchilin, Vladimir P.

    2009-01-01

    The proteolytic cleavage of TATp, TATp-PEG1000-PE conjugate (TATp-conjugate), and TATp as TATp-conjugate in mixed micelles made of TATp-conjugate and PEG5000-PE (2.5% mol of TATp-conjugate, TATp-Mic) were studied by HPLC with fluorescent detection using fluorenylmethyl chloroformate (FMOC) labeling and by MALDI-TOF MS analysis. The cleavage kinetics were analyzed in human blood plasma and in trypsin-containing phosphate buffered saline (PBS), pH 7.4, to simulate the proteolytic activity of hu...

  12. Natural antibodies in normal human serum inhibit Staphylococcus aureus capsular polysaccharide vaccine efficacy.

    Science.gov (United States)

    Skurnik, David; Kropec, Andrea; Roux, Damien; Theilacker, Christian; Huebner, Johannes; Pier, Gerald B

    2012-11-01

    Vaccines against Streptococcus pneumoniae, Neisseria meningitidis, and Hemophilus influenzae type b induce functional opsonic or bactericidal antibodies to surface capsular polysaccharides (CP). Targeting the comparable Staphylococcus aureus CP seems logical, but to date such efforts have failed in human trials. Studies using immunization-induced animal antibodies have documented interference in opsonic and protective activities of antibodies to CP by antibodies to another S. aureus cell surface polysaccharide, poly-N-acetyl glucosamine (PNAG). Here we evaluated whether natural antibody to PNAG in normal human serum (NHS) had a similar deleterious effect. Functional and/or protective activities of antibody to S. aureus CP and PNAG antigens in patients with bacteremia, in mice immunized with combinations of CP and PNAG conjugate vaccines, and in serum samples of healthy subjects with natural antibody to PNAG, to which immunization-induced animal antibodies to CP antigens were added, were evaluated. Antibodies to PNAG and CP that mutually interfered with opsonic killing of S. aureus were detected in 9 of 15 bacteremic patients. Active immunization of mice with combinations of PNAG and CP conjugate antigens always induced antibodies that interfered with each other's functional activity. Non-opsonic natural antibodies to PNAG found in NHS interfered with the functional and protective activities of immunization-induced antibody to CP antigens during experimental infection with S. aureus. Both immunization-induced animal antibodies and natural antibodies to PNAG in NHS interfere with the protective activities of immunization-induced antibody to S. aureus CP5 and CP8 antigens, representing potential barriers to successful use of CP-specific vaccines.

  13. 15th International Conference on Human Antibodies and Hybridomas. 14-16 April 2010, Tiara Park Atlantico Hotel, Porto, Portugal.

    Science.gov (United States)

    Kotlan, Beatrix

    2010-11-01

    Antibodies and antibody conjugates are currently one of the largest classes of new drug entities under development. These versatile molecules are being investigated for the treatment of many pathological conditions, such as cancer and infectious, inflammatory and autoimmune diseases. Antibodies can exert biological effects as naked antibodies by themselves, or can be used as delivery agents conjugated with various drugs (e.g., immunoconjugates) and as tools of multistep targeting. Site-specific delivery of therapeutic agents has been the ultimate goal of the pharmaceutical industry, as it has the potential to maximize drug efficiency while minimizing side effects. Antibodies have much potential for this objective. Thus, it is useful to summarize some of the main strategies currently being employed for the development of these diverse therapeutic molecules and to highlight the recent novelties in the field. These goals were the focus of the 15th International Conference on Human Antibodies and Hybridomas, held during 14-16 April 2010 in Porto, Portugal.

  14. Protection induced by pneumococcal surface protein A (PspA) is enhanced by conjugation to a Streptococcus pneumoniae capsular polysaccharide.

    Science.gov (United States)

    Csordas, Fátima C L; Perciani, Cátia T; Darrieux, Michelle; Gonçalves, Viviane M; Cabrera-Crespo, Joaquim; Takagi, Mickie; Sbrogio-Almeida, Maria E; Leite, Luciana C C; Tanizaki, Martha M

    2008-06-02

    The currently available anti-pneumococcal vaccines are based on capsular polysaccharide (PS), plain or conjugated to a carrier protein. Conjugated vaccines are expensive products, especially in the case of pneumococcus, in which reasonable coverage requires from 7 to 13 serotypes. To obtain increased coverage with fewer components, we evaluated the immunogenicity of the pneumococcal surface protein A (PspA), conjugated to capsular polysaccharide serotype 23F, aiming at induction of an immune response against both components. Mice immunized with PS23F-rPspA1 conjugate produced antibodies against both PS and rPspA1, comparable or slightly higher than that obtained by free PS. The immunized animals challenged with a lethal dose of a virulent strain bearing a homologous PspA, showed that the PS23F-rPspA1 conjugate induced higher survival than rPspA1 alone or in combination with PS. This increased protection was shown to correlate with the enhanced capacity of the antibodies to bind to the pneumococcal surface and to induce complement deposition. Our results indicate that the use of PS-PspA conjugates may be a way to increase coverage against pneumococci with fewer components.

  15. Pneumococcal conjugate vaccination does not induce a persisting mucosal IgA response in children with recurrent acute otitis media.

    NARCIS (Netherlands)

    Bogaert, D.; Veenhoven, R.H.; Ramdin, R.; Luijendijk, I.H.; Rijkers, G.T.; Sanders, E.A.M.; Groot, R. de; Hermans, P.W.M.

    2005-01-01

    AIM: In a prospective controlled study in young children with a history of recurrent acute otitis media, we analyzed the salivary IgA and IgG antibody titers upon vaccination with a 7-valent pneumococcal conjugate vaccine (PCV) given once or twice, followed by a 23-valent polysaccharide booster

  16. Conjugated Polymers for Energy Production

    DEFF Research Database (Denmark)

    Livi, Francesco

    for scalable PSCs fully printed under ambient conditions [Adv. Energy Mater. 2015, 5, 1402186]. PPDTBT resulted to be the conjugated polymer with the best photovoltaic performance within the 104 synthesized macromolecules. Therefore, further studies have been done on such material. The impact of side chain......This dissertation is aimed at developing materials for flexible, large area, ITO-free polymer solar cells (PSCs) fully printed under ambient conditions. A large screening of conjugated polymers, both novel and well-known materials, has been carried out in order to find suitable candidates.......The reactivity of DArP has been further studied and applied to the synthesis of fluorinated copolymers featuring thiophene, which are largely used materials for organic electronics. In particular, by moving the bromine functionality from one monomer to the other, a big impact on the reactivity has been observed...

  17. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets...... with transcobalamin (TC), but not so efficient with the homologous glycoproteins intrinsic factor and haptocorrin. Binding of the B12 octadecanucleotide to TC suggests the capacity of the B12 moiety to serve as a natural vector for specific transport of single stranded, organometallic oligonucleotide loads from...... in humans and animals, through the endogenous B12 transport systems. Binding of the organometallic B12 octadecanucleotide to the three important human proteins of B12 transport was studied, to examine its structural suitability for the task of eventual in vivo oligonucleotide delivery. Binding was efficient...

  18. Correlation of group C meningococcal conjugate vaccine response with B- and T-lymphocyte activity.

    Directory of Open Access Journals (Sweden)

    James B Wing

    Full Text Available Despite the success of conjugate vaccination against meningococcal group C (MenC disease, post-vaccination, some individuals still exhibit rapid waning of initially protective bactericidal antibody levels. The mechanism of this relative loss of humoral protection remains undetermined. In this report we have investigated the relationship between T- and B-cell activation and co-stimulation and the loss of protective antibody titers. We have found that healthy volunteers who lose protective MenC antibody levels one year after receipt of glycoconjugate vaccine exhibit no detectable cellular defect in polyclonal B- or T-cell activation, proliferation or the B-memory pool. This suggests that the processes underlying the more rapid loss of antibody levels are independent of defects in either initial T- or B-cell activation.

  19. The determination of the rate of conjugation of immunoglobulin with a bifunctional chelator

    International Nuclear Information System (INIS)

    Malek, Z.; Miler, V.; Budsky, F.

    2006-01-01

    Imaging of cell's antigens with the use of labelled immunoglobulins allows imaging of specific receptors on cell membrane and specific tumours. It is necessary to carry out the labelling of the immunoglobulins with radionuclides of suitable physical properties which form cations (e.g., 111 In, 90 Y, 177 Lu) that form very strong chelates of sufficiently high stability constant preventing the dissociation of complexes or the radionuclide under 'in-vivo' conditions. The immunoglobulin must be conjugated with the bifunctional chelator (BCH), which contains both chelating unit and reactive group for binding to the immunoglobulin. In our laboratory we have conjugated human IgG and monoclonal antibody CD20 with diethylenetriamine pentaacetic acid dianhydride (cDTPAA). Radionuclides 90 Y and 177 Lu prepared on the LVR-15 reactor were used for labelling. After conjugation and labelling the yields in relation to the amount of isotopic carrier have been determined

  20. Low-Cost Peptide Microarrays for Mapping Continuous Antibody Epitopes.

    Science.gov (United States)

    McBride, Ryan; Head, Steven R; Ordoukhanian, Phillip; Law, Mansun

    2016-01-01

    With the increasing need for understanding antibody specificity in antibody and vaccine research, pepscan assays provide a rapid method for mapping and profiling antibody responses to continuous epitopes. We have developed a relatively low-cost method to generate peptide microarray slides for studying antibody binding. Using a setup of an IntavisAG MultiPep RS peptide synthesizer, a Digilab MicroGrid II 600 microarray printer robot, and an InnoScan 1100 AL scanner, the method allows the interrogation of up to 1536 overlapping, alanine-scanning, and mutant peptides derived from the target antigens. Each peptide is tagged with a polyethylene glycol aminooxy terminus to improve peptide solubility, orientation, and conjugation efficiency to the slide surface.

  1. Synthesis of aminobenzyltriethylenetetraaminohexaacetic acid: conjugation of the chelator to protein by an alkylamine linkage.

    Science.gov (United States)

    Bhargava, K K; Zhang, Z Y; Palestro, C J; Acharya, S A

    1999-10-01

    The conjugation of a chelating agent to an antibody as an anchoring site for a radionuclide is the first step in the successful preparation of a radiolabeled antibody for a diagnostic and therapeutic application. The high affinity of the protein bound chelator towards radionuclide ensures a higher selectivity in the delivery of the radionuclide to the targeted tissue. 4-Aminobenzylderivativetriethlenetetraaminohexaacetic acid (TTHA), a hexadentate chelating agent has been now prepared for conjugation with proteins in view of the higher affinity of TTHA metal ions as compared to DTPA. The latent crosslinking potential of alpha-hydroxy aldehydes has been used to conjugate the new chelating agent to proteins through an alkylamine linkage. On incubation of amino benzyl TTHA with glycoladehyde at neutral pH and room temperature, the reagent is converted to oxo ethyl amino benzyl TTHA. On addition of albumin to this reaction mixture, the oxo ethylamino benzyl TTHA generates reversible schiff base adducts with the amino groups of albumin. The reduction of the Schiff base adducts of the chelator with the protein by sodium cyanoborohydride stabilizes the schiff base adducts as stable alkylamine linkages. 4-Thiocyanatobenzyl TTHA has also been prepared and conjugated to albumin through a thiocarbamoyl linkage. Both preparations of TTHA conjugated albumin complexed with 99mTc and 111In, with high affinity and no decomposition of the complex was noticed for at least up to 6 hrs after the preparation. The radiolabels complexed with these TTHA -albumin conjugates could not be 'chased' out by free DTPA. A comparison of the biodistribution of 111In, bound to the TTHA conjugated through an alkylamine and a thiocarbamoyl linkage showed that 111In complexed with alkylamine linked TTHA was retained in blood to a level nearly 17% higher compared to that seen with thicarbamoyl linked TTHA, one hr after the injection into mice. Thus, the alkylamine linkage appears to be more stable under

  2. IBC's 23rd Antibody Engineering and 10th Antibody Therapeutics Conferences and the Annual Meeting of The Antibody Society: December 2-6, 2012, San Diego, CA.

    Science.gov (United States)

    Marquardt, John; Begent, Richard H J; Chester, Kerry; Huston, James S; Bradbury, Andrew; Scott, Jamie K; Thorpe, Philip E; Veldman, Trudi; Reichert, Janice M; Weiner, Louis M

    2012-01-01

    Now in its 23rd and 10th years, respectively, the Antibody Engineering and Antibody Therapeutics conferences are the Annual Meeting of The Antibody Society. The scientific program covers the full spectrum of challenges in antibody research and development from basic science through clinical development. In this preview of the conferences, the chairs provide their thoughts on sessions that will allow participants to track emerging trends in (1) the development of next-generation immunomodulatory antibodies; (2) the complexity of the environment in which antibodies must function; (3) antibody-targeted central nervous system (CNS) therapies that cross the blood brain barrier; (4) the extension of antibody half-life for improved efficacy and pharmacokinetics (PK)/pharmacodynamics (PD); and (5) the application of next generation DNA sequencing to accelerate antibody research. A pre-conference workshop on Sunday, December 2, 2012 will update participants on recent intellectual property (IP) law changes that affect antibody research, including biosimilar legislation, the America Invents Act and recent court cases. Keynote presentations will be given by Andreas Plückthun (University of Zürich), who will speak on engineering receptor ligands with powerful cellular responses; Gregory Friberg (Amgen Inc.), who will provide clinical updates of bispecific antibodies; James D. Marks (University of California, San Francisco), who will discuss a systems approach to generating tumor targeting antibodies; Dario Neri (Swiss Federal Institute of Technology Zürich), who will speak about delivering immune modulators at the sites of disease; William M. Pardridge (University of California, Los Angeles), who will discuss delivery across the blood-brain barrier; and Peter Senter (Seattle Genetics, Inc.), who will present his vision for the future of antibody-drug conjugates. For more information on these meetings or to register to attend, please visit www.IBCLifeSciences.com/Antibody

  3. The effects of conjugate and light dose on photo-immunotherapy induced cytotoxicity.

    Science.gov (United States)

    Nakajima, Takahito; Sato, Kazuhide; Hanaoka, Hirofumi; Watanabe, Rira; Harada, Toshiko; Choyke, Peter L; Kobayashi, Hisataka

    2014-05-30

    Photoimmunotherapy (PIT) is a highly cell-selective cancer therapy, which employs monoclonal antibodies conjugated to a potent photosensitizer (mAb-IR700). Once the conjugate has bound to the target cell, exposure to near infrared (NIR) light induces necrosis only in targeted cells with minimal damage to adjacent normal cells in vivo. Herein, we report on the effect of altering mAb-IR700 and light power and dose on effectiveness of PIT. For evaluating cytotoxicity, we employed ATP-dependent bioluminescence imaging using a luciferase-transfected MDA-MB-468luc cell line, which expresses EGFR and luciferase. In in vitro experiments, panitumumab-IR700 (Pan-IR700) concentration was varied in combination with varying NIR light doses administered by an LED at one of three power settings, 100 mA and 400 mA continuous wave and 1733 mA intermittent wave. For in vivo experiments, the MDA-MB-468luc orthotopic breast cancer was treated with varying doses of Pan-IR700 and light. The in vitro cell study demonstrated that PIT induced cytotoxicity depended on light dose, when the conjugate concentration was kept constant. Increasing the dose of Pan-IR700 allowed lowering of the light dose to achieve equal effects thus indicating that for a given level of efficacy, the conjugate concentration multiplied by the light dose was a constant. A similar relationship between conjugate and light dose was observed in vivo. The efficacy of PIT is defined by the product of the number of bound antibody conjugates and the dose of NIR light and can be achieve equally with continuous and pulse wave LED light using different power densities.

  4. Acetylcholine receptor antibody

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003576.htm Acetylcholine receptor antibody To use the sharing features on this page, please enable JavaScript. Acetylcholine receptor antibody is a protein found in the blood ...

  5. Platelet antibodies blood test

    Science.gov (United States)

    This blood test shows if you have antibodies against platelets in your blood. Platelets are a part of the blood ... Chernecky CC, Berger BJ. Platelet antibody - blood. In: Chernecky ... caused by platelet destruction, hypersplenism, or hemodilution. ...

  6. Anti-CD20 multivalent HPMA copolymer-Fab′ conjugates for the direct induction of apoptosis

    OpenAIRE

    Chu, Te-Wei; Yang, Jiyuan; Kopeček, Jindřich

    2012-01-01

    A hybrid biomimetic system comprising high-molecular-weight, linear copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) grafted with multiple Fab′ fragments of anti-CD20 monoclonal antibody (mAb) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization followed by attachment of Fab′ fragments via thioether bonds. Exposure of human non-Hodgkin’s lymphoma (NHL) Raji B cells to the multivalent conjugates resulted in crosslinking of CD20 receptors and commenceme...

  7. Evaluation of Immunogenicity of Yersinia enterocolitica O:8 Oligopolysaccaride-DiphtheriaeToxoide Conjugate in Mice

    Directory of Open Access Journals (Sweden)

    SM Rezavian

    2015-06-01

    Full Text Available Background & objectives: Yersiniosis is created by Yersinia enterocolitica O:8 and causes problems in the world especialy in cold and mild countries. The purpose of this study is to evaluate the immunogenicity of Yersinia enterocolitica O:8 oligopolysaccaride (OPS conjugate to diphtheria toxoid (DT as a vaccine candidate.   Methods : After cultivation of bacteria, the LPS were isolated by modified hot phenol method. Then dialysis and concentration were done and the OPS were extracted by acetic acid 2%. To conjugate with diphtheria toxoid, ADH was used as a spacer molecule and EDAC as a linker. Conjugate was purified by gel filtration. Then 4 groups of female BALB/c mice were selected (15 mice in each group. Injection was performed intraperitoneally in three doses with two weeks interval. Then serum samples were collected and antibody response against OPS was measured by indirect ELISA method for detection of total IgG, IgA, IgM, IgG1, IgG2a, IgG2b and IgG3.   Results: After second and third doses, OPS-DT recieved group showed significant increase in all types of antibodies titer in anti-OPS in comparison to group that recived nonconjugated OPS. The increase in titer of antibodies was as: OPS-DT>OPS>DT. A remarkable increase was shown in total IgG and IgM titers (with total amount of 3204 and 670, respectively. In IgG1 subclass the amount was 920 and in other subclasses of IgG (IgG3, IgG2a and IgG2b the amounts were 910, 110, and 99, respectively.   Conclusion: The results shows that OPS of Yersinia enterocolitica O:8 increases the anti-OPS antibodies in the form of conjugate with diphtheria toxoid and could be considered as an appropriate vaccine candidate.

  8. Testing of Ruggedized Antibodies within a Lateral Flow Immunoassay

    Science.gov (United States)

    2017-10-01

    derived from antiricin Mab2. AxioMx technicians rely on a proprietary graft and affinity maturation protocol to develop ruggedized immunoglobulin G (IgG...Antiricin Mab2 (nonthermostable) B. APE36633.03 C. D12f101013 D . 1GX0207 E. 1GX2691 F. RIC-03-A-G1 (nonthermostable) Gold Conjugation 1...Zabetakis, D .; Goldman, E. Binding Kinetics of Antiricin Single Domain Antibodies and Improved Detection Using a B Chain Specific Binder. Anal. Chem

  9. Quantitative assessment of antibody internalization with novel monoclonal antibodies against Alexa fluorophores.

    Directory of Open Access Journals (Sweden)

    Sindy Liao-Chan

    Full Text Available Antibodies against cell surface antigens may be internalized through their specific interactions with these proteins and in some cases may induce or perturb antigen internalization. The anti-cancer efficacy of antibody-drug conjugates is thought to rely on their uptake by cancer cells expressing the surface antigen. Numerous techniques, including microscopy and flow cytometry, have been used to identify antibodies with desired cellular uptake rates. To enable quantitative measurements of internalization of labeled antibodies, an assay based on internalized and quenched fluorescence was developed. For this approach, we generated novel anti-Alexa Fluor monoclonal antibodies (mAbs that effectively and specifically quench cell surface-bound Alexa Fluor 488 or Alexa Fluor 594 fluorescence. Utilizing Alexa Fluor-labeled mAbs against the EphA2 receptor tyrosine kinase, we showed that the anti-Alexa Fluor reagents could be used to monitor internalization quantitatively over time. The anti-Alexa Fluor mAbs were also validated in a proof of concept dual-label internalization assay with simultaneous exposure of cells to two different mAbs. Importantly, the unique anti-Alexa Fluor mAbs described here may also enable other single- and dual-label experiments, including label detection and signal enhancement in macromolecules, trafficking of proteins and microorganisms, and cell migration and morphology.

  10. Reduction-sensitive liposomes from a multifunctional lipid conjugate and natural phospholipids: reduction and release kinetics and cellular uptake.

    Science.gov (United States)

    Goldenbogen, Björn; Brodersen, Nicolai; Gramatica, Andrea; Loew, Martin; Liebscher, Jürgen; Herrmann, Andreas; Egger, Holger; Budde, Bastian; Arbuzova, Anna

    2011-09-06

    The development of targeted and triggerable delivery systems is of high relevance for anticancer therapies. We report here on reduction-sensitive liposomes composed of a novel multifunctional lipidlike conjugate, containing a disulfide bond and a biotin moiety, and natural phospholipids. The incorporation of the disulfide conjugate into vesicles and the kinetics of their reduction were studied using dansyl-labeled conjugate 1 in using the dansyl fluorescence environmental sensitivity and the Förster resonance energy transfer from dansyl to rhodamine-labeled phospholipids. Cleavage of the disulfide bridge (e.g., by tris(2-carboxyethyl)phosphine (TCEP), dithiothreitol (DTT), l-cysteine, or glutathione (GSH)) removed the hydrophilic headgroup of the conjugate and thus changed the membrane organization leading to the release of entrapped molecules. Upon nonspecific uptake of vesicles by macrophages, calcein release from reduction-sensitive liposomes consisting of the disulfide conjugate and phospholipids was more efficient than from reduction-insensitive liposomes composed only of phospholipids. The binding of streptavidin to the conjugates did not interfere with either the subsequent reduction of the disulfide bond of the conjugate or the release of entrapped molecules. Breast cancer cell line BT-474, overexpressing the HER2 receptor, showed a high uptake of the reduction-sensitive doxorubicin-loaded liposomes functionalized with the biotin-tagged anti-HER2 antibody. The release of the entrapped cargo inside the cells was observed, implying the potential of using our system for active targeting and delivery. © 2011 American Chemical Society

  11. Immunogenicity of meningococcal B polysaccharide conjugated to tetanus toxoid or CRM197 via adipic acid dihydrazide.

    Science.gov (United States)

    Bartoloni, A; Norelli, F; Ceccarini, C; Rappuoli, R; Costantino, P

    1995-04-01

    Vaccine development against Group B Neisseria meningitidis is complicated by the nature of the capsular polysaccharide, which is alpha 2-8-linked poly-sialic acid, identical in structure to the poly-sialic acid found in many mammalian tissues during development. To test the feasibility of a vaccine based on this polysaccharide, we synthesized several conjugates of meningococcal B polysaccharide linked to a carrier protein (tetanus toxoid or diphtheria CRM197), via an adipic acid dihydrazide (ADH) spacer. All conjugates induced a strong immune response. However, most of the antibodies were not directed against the Meningococcus B polysaccharide and could not be inhibited by the purified polysaccharide alone. Further investigations showed that the antibodies recognized an epitope composed by the junction between the spacer and the polysaccharide and protein, that is not present in the native polysaccharide and is generated during the coupling reaction. This epitope becomes immunodominant with respect to the poorly immunogenic polysaccharide. While the majority of the immune response is directed against the above epitope, the conjugates induced also an immune response against the Meningococcus B polysaccharide. The anti-Meningococcus B antibodies elicited are of the IgM and IgG class and are inhibitable by the polysaccharide. Moreover, they are bactericidal, thus suggesting that they would induce protection against disease.

  12. Modelling conjugation with stochastic differential equations.

    Science.gov (United States)

    Philipsen, K R; Christiansen, L E; Hasman, H; Madsen, H

    2010-03-07

    Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two Enterococcus faecium strains in a rich exhaustible media. The model contains a new expression for a substrate dependent conjugation rate. A maximum likelihood based method is used to estimate the model parameters. Different models including different noise structure for the system and observations are compared using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared to the model without plate conjugation. The modelling approach described in this article can be applied generally when modelling dynamical systems. 2009 Elsevier Ltd. All rights reserved.

  13. Comparative immunogenicity of conjugates composed of the Staphylococcus aureus type 8 capsular polysaccharide bound to carrier proteins by adipic acid dihydrazide or N-succinimidyl-3-(2-pyridyldithio)propionate.

    Science.gov (United States)

    Fattom, A; Shiloach, J; Bryla, D; Fitzgerald, D; Pastan, I; Karakawa, W W; Robbins, J B; Schneerson, R

    1992-01-01

    Staphylococcus aureus type 8 capsular polysaccharide (CP) was conjugated either to diphtheria toxoid or to Pseudomonas aeruginosa recombinant exoprotein A by using adipic acid dihydrazide (ADH) or N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) as the joining reagent. The polysaccharide/protein ratios of these two pairs of conjugates were similar. The two synthetic schemes bound the linker to the carboxyls of the type 8 CP by carbodiimide-mediated condensation. ADH was bound to the carboxyls of the protein, whereas SPDP reacted with the amino groups of the protein. Intermolecular linking of the carrier protein, caused by the carbodiimide during the conjugation reaction with the type 8 CP derivative, probably accounts for the larger size of the conjugates formed with ADH compared with those formed with SPDP. Both conjugates synthesized with ADH elicited higher levels of CP antibodies, especially after the first immunization, than did those prepared with SPDP. Similar levels of exoprotein A antibodies were elicited by both conjugates. Higher levels of diphtheria toxoid antibodies were elicited by the conjugate prepared with SPDP than by the one prepared with ADH. The basis for the differences in the immunogenicities of these two pairs of S. aureus type 8 CP conjugates is discussed. PMID:1730492

  14. Monoclonal antibodies and cancer

    International Nuclear Information System (INIS)

    Haisma, H.J.

    1987-01-01

    The usefulness of radiolabeled monoclonal antibodies for imaging and treatment of human (ovarian) cancer was investigated. A review of tumor imaging with monoclonal antibodies is presented. Special attention is given to factors that influence the localization of the antibodies in tumors, isotope choice and methods of radiolabeling of the monoclonal antibodies. Two monoclonal antibodies, OC125 and OV-TL3, with high specificity for human epithelial ovarian cancer are characterized. A simple radio-iodination technique was developed for clinical application of the monoclonal antibodies. The behavior of monoclonal antibodies in human tumor xenograft systems and in man are described. Imaging of tumors is complicated because of high background levels of radioactivity in other sites than the tumor, especially in the bloodpool. A technique was developed to improve imaging of human tumor xenographs in nude mice, using subtraction of a specific and a non-specific antibody, radiolabeled with 111 In, 67 Ga and 131 I. To investigate the capability of the two monoclonal antibodies, to specifically localize in human ovarian carcinomas, distribution studies in mice bearing human ovarian carcinoma xenografts were performed. One of the antibodies, OC125, was used for distribution studies in ovarian cancer patients. OC125 was used because of availability and approval to use this antibody in patients. The same antibody was used to investigate the usefulness of radioimmunoimaging in ovarian cancer patients. The interaction of injected radiolabeled antibody OC125 with circulating antigen and an assay to measure the antibody response in ovarian cancer patients after injection of the antibody is described. 265 refs.; 30 figs.; 19 tabs

  15. Exploring cancer metastasis prevention strategy: interrupting adhesion of cancer cells to vascular endothelia of potential metastatic tissues by antibody-coated nanomaterial.

    Science.gov (United States)

    Xie, Jingjing; Dong, Haiyan; Chen, Hongning; Zhao, Rongli; Sinko, Patrick J; Shen, Weiyu; Wang, Jichuang; Lu, Yusheng; Yang, Xiang; Xie, Fangwei; Jia, Lee

    2015-02-03

    Cancer metastasis caused by circulating tumor cells (CTCs) accounts for 90% cancer-related death worldwide. Blocking the circulation of CTCs in bloodstream and their hetero-adhesion to vascular endothelia of the distant metastatic organs may prevent cancer metastasis. Nanomaterial-based intervention with adhesion between CTCs and endothelia has not been reported. Driven by the novel idea that multivalent conjugation of EpCAM and Slex antibodies to dendrimer surface may enhance the capacity and specificity of the nanomaterial conjugates for capturing and down-regulating colorectal CTCs, we conjugated the dendrimer nanomaterial with the EpCAM and Slex antibodies, and examined the capacity of the dual antibody-coated nanomaterial for their roles in interrupting CTCs-related cancer metastasis. The antibody-coated nanomaterial was synthesized and characterized. The conjugates specifically bound and captured colon cancer cells SW620. The conjugate inhibited the cells' viability and their adhesion to fibronectin (Fn)-coated substrate or human umbilical vein endothelial cells (HUVECs) in a concentration-dependent manner. In comparison with SW480 and LoVo cell lines, the activity and adhesion of SW620 to Fn-coated substrate and HUVECs were more specifically inhibited by the dual antibody conjugate because of the higher levels of EpCAM and Slex on SW620 cell surface. The hetero-adhesion between SW620 and Fn-coated substrate, or HUVECs was inhibited by about 60-70%. The dual conjugate showed the inhibition capacity more significant than its corresponding single antibody conjugates. The present study provides the new evidence that coating nanomaterials with more than one antibody against CTCs may effectively interfere with the interaction between SW620 and HUVECs.

  16. Evaluation of bio-conjugation methods for obtaining of synthetic positive control for IgM-capture ELISA

    Directory of Open Access Journals (Sweden)

    O. Y. Galkin

    2014-10-01

    Full Text Available The enzyme-linked immunosorbent assay (ELISA is the most informative and versatile method of serological diagnostics. The possibility of detecting by ELISA specific antibodies of different classes allow to differentiate primary infectious process and its remission, exacerbation and chronic disease (differential diagnosis. This approach is implemented in the methodology for evaluation of patients for the presence of humoral immune response to TORCH-infections pathogens (toxoplasmosis, rubella, cytomegalovirus, herpes simplex viruses’ infections, and some others. Therefore, testing for presence of specific IgG and IgM antibodies against TORCH-infections pathogens in blood serum is an important element of motherhood and childhood protection. The essential problem in the production of IgM-capture ELISA diagnostic kits is obtaining of positive control. The classic version of positive control is human blood serum (plasma containing specific antibodies. But specific IgM-positive sera are insignificant raw materials. This fact can seriously restrict the production of diagnostic kits, especially in the event of large-scale production. We have suggested the methodological approach to using of synthetic positive controls in IgM-capture ELISA kits based on conjugate of normal human IgM and monoclonal antibodies against horseradish peroxidase. It is found that this task can be fulfilled by means of NHS ester-maleimide-mediated conjugation (by sulfosuccinimidyl-4-(N-maleimidomethylcyclohexane-1-carboxylate, reductive amination-mediated conjugation (by sodium periodate and glutaraldehyde-mediated conjugation. It was found that conjugates of normal human IgM and monoclonal antibodies against horseradish peroxidase obtained using NHS ester-mediated maleimide conjugation and periodate method were similar by molecular weight, whereas conjugate synthesized by glutaraldehyde method comprised at least three types of biopolymers with close molecular weight. It was

  17. Diclofenac hypersensitivity: antibody responses to the parent drug and relevant metabolites.

    Directory of Open Access Journals (Sweden)

    Andrea Harrer

    2010-10-01

    Full Text Available Hypersensitivity reactions against nonsteroidal antiinflammatory drugs (NSAIDs like diclofenac (DF can manifest as Type I-like allergic reactions including systemic anaphylaxis. However, except for isolated case studies experimental evidence for an IgE-mediated pathomechanism of DF hypersensitivity is lacking. In this study we aimed to investigate the possible involvement of drug- and/or metabolite-specific antibodies in selective DF hypersensitivity.DF, an organochemically synthesized linkage variant, and five major Phase I metabolites were covalently coupled to carrier proteins. Drug conjugates were analyzed for coupling degree and capacity to crosslink receptor-bound IgE antibodies from drug-sensitized mice. With these conjugates, the presence of hapten-specific IgE antibodies was investigated in patients' samples by ELISA, mediator release assay, and basophil activation test. Production of sulfidoleukotrienes by drug conjugates was determined in PBMCs from DF-hypersensitive patients. All conjugates were shown to carry more than two haptens per carrier molecule. Immunization of mice with drug conjugates induced drug-specific IgE antibodies capable of triggering mediator release. Therefore, the conjugates are suitable tools for detection of drug-specific antibodies and for determination of their anaphylactic activity. Fifty-nine patients were enrolled and categorized as hypersensitive either selectively to DF or to multiple NSAIDs. In none of the patients' samples evidence for drug/metabolite-specific IgE in serum or bound to allergic effector cells was found. In contrast, a small group of patients (8/59, 14% displayed drug/metabolite-specific IgG.We found no evidence for an IgE-mediated effector mechanism based on haptenation of protein carriers in DF-hypersensitive patients. Furthermore, a potential involvement of the most relevant metabolites in DF hypersensitivity reactions could be excluded.

  18. Restriction of anti-peptide antibody specificity by enzyme-modified Sepharose-peptide immunoadsorbents.

    Science.gov (United States)

    Trinca, M L; Muratti, E; Camera, M; Chersi, A

    1988-06-01

    Sepharose-peptide immunoadsorbents, employed for the isolation of specific antibodies from the sera of rabbits immunized with carrier protein-peptide conjugates, were digested with suitable proteolytic enzymes, in order to obtain the splitting of a part of the peptide bound to the gel. This new modified immunoadsorbent can be advantageously used for the isolation of antibody subsets, that do not cross-react with related peptides exhibiting high sequence homology with the immunogens.

  19. A generic mechanism in Neisseria meningitidis for enhanced resistance against bactericidal antibodies

    OpenAIRE

    Uria, Maria Jose; Zhang, Qian; Li, Yanwen; Chan, Angel; Exley, Rachel M.; Gollan, Bridget; Chan, Hannah; Feavers, Ian; Yarwood, Andy; Abad, Raquel; Borrow, Ray; Fleck, Roland A.; Mulloy, Barbara; Vazquez, Julio A.; Tang, Christoph M.

    2008-01-01

    The presence of serum bactericidal antibodies is a proven correlate of protection against systemic infection with the important human pathogen Neisseria meningitidis. We have identified three serogroup C N. meningitidis (MenC) isolates recovered from patients with invasive meningococcal disease that resist killing by bactericidal antibodies induced by the MenC conjugate vaccine. None of the patients had received the vaccine, which has been successfully introduced in countries in North America...

  20. Mass Spectrometry Based Mechanistic Insights into Formation of Tris Conjugates: Implications on Protein Biopharmaceutics

    Science.gov (United States)

    Kabadi, Pradeep G.; Sankaran, Praveen Kallamvalliillam; Palanivelu, Dinesh V.; Adhikary, Laxmi; Khedkar, Anand; Chatterjee, Amarnath

    2016-10-01

    We present here extensive mass spectrometric studies on the formation of a Tris conjugate with a therapeutic monoclonal antibody. The results not only demonstrate the reactive nature of the Tris molecule but also the sequence and reaction conditions that trigger this reactivity. The results corroborate the fact that proteins are, in general, prone to conjugation and/or adduct formation reactions and any modification due to this essentially leads to formation of impurities in a protein sample. Further, the results demonstrate that the conjugation reaction happens via a succinimide intermediate and has sequence specificity. Additionally, the data presented in this study also shows that the Tris formation is produced in-solution and is not an in-source phenomenon. We believe that the facts given here will open further avenues on exploration of Tris as a conjugating agent as well as ensure that the use of Tris or any ionic buffer in the process of producing a biopharmaceutical drug is monitored closely for the presence of such conjugate formation.

  1. The Tcp conjugation system of Clostridium perfringens.

    Science.gov (United States)

    Wisniewski, Jessica A; Rood, Julian I

    2017-05-01

    The Gram-positive pathogen Clostridium perfringens possesses a family of large conjugative plasmids that is typified by the tetracycline resistance plasmid pCW3. Since these plasmids may carry antibiotic resistance genes or genes encoding extracellular or sporulation-associated toxins, the conjugative transfer of these plasmids appears to be important for the epidemiology of C. perfringens-mediated diseases. Sequence analysis of members of this plasmid family identified a highly conserved 35kb region that encodes proteins with various functions, including plasmid replication and partitioning. The tcp conjugation locus also was identified in this region, initially based on low-level amino acid sequence identity to conjugation proteins from the integrative conjugative element Tn916. Genetic studies confirmed that the tcp locus is required for conjugative transfer and combined with biochemical and structural analyses have led to the development of a functional model of the Tcp conjugation apparatus. This review summarises our current understanding of the Tcp conjugation system, which is now one of the best-characterized conjugation systems in Gram-positive bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Chemistry of Oligonucleotibe-Gold Nanoparticle Conjugates

    National Research Council Canada - National Science Library

    Letsinger, Robert

    2003-01-01

    Conjugates prepared by immobilizing thiol-terminated oligonucleotides onto gold nanoparticles from stable colloidal solutions in aqueous media The oligo nucleotides can serve as linkers to organize...

  3. Modelling conjugation with stochastic differential equations

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Hasman, Henrik

    2010-01-01

    using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared......Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two...

  4. Radiolabeled antibody imaging

    International Nuclear Information System (INIS)

    Wahl, R.L.

    1987-01-01

    Radiolabeled antibodies, in particular monoclonal antibodies, offer the potential for the specific nuclear imaging of malignant and benign diseases in man. If this imaging potential is realized, they may also have a large role in cancer treatment. This paper reviews: (1) what monoclonal antibodies are and how they differ from polyclonal antibodies, (2) how they are produced and radiolabeled, (3) the results of preclinical and clinical trials in cancer imaging, including the utility of SPECT and antibody fragments, (4) the role of antibodies in the diagnosis of benign diseases, (5) alternate routes of antibody delivery, (6) the role of these agents in therapy, and (7) whether this technology ''revolutionizes'' the practice of nuclear radiology, or has a more limited complementary role in the imaging department

  5. High-content Analysis of Antibody Phage-display Library Selection Outputs Identifies Tumor Selective Macropinocytosis-dependent Rapidly Internalizing Antibodies*

    Science.gov (United States)

    Ha, Kevin D.; Bidlingmaier, Scott M.; Zhang, Yafeng; Su, Yang; Liu, Bin

    2014-01-01

    Many forms of antibody-based targeted therapeutics, including antibody drug conjugates, utilize the internalizing function of the targeting antibody to gain intracellular entry into tumor cells. Ideal antibodies for developing such therapeutics should be capable of both tumor-selective binding and efficient endocytosis. The macropinocytosis pathway is capable of both rapid and bulk endocytosis, and recent studies have demonstrated that it is selectively up-regulated by cancer cells. We hypothesize that receptor-dependent macropinocytosis can be achieved using tumor-targeting antibodies that internalize via the macropinocytosis pathway, improving potency and selectivity of the antibody-based targeted therapeutic. Although phage antibody display libraries have been utilized to find antibodies that bind and internalize to target cells, no methods have been described to screen for antibodies that internalize specifically via macropinocytosis. We hereby describe a novel screening strategy to identify phage antibodies that bind and rapidly enter tumor cells via macropinocytosis. We utilized an automated microscopic imaging-based, High Content Analysis platform to identify novel internalizing phage antibodies that colocalize with macropinocytic markers from antibody libraries that we have generated previously by laser capture microdissection-based selection, which are enriched for internalizing antibodies binding to tumor cells in situ residing in their tissue microenvironment (Ruan, W., Sassoon, A., An, F., Simko, J. P., and Liu, B. (2006) Identification of clinically significant tumor antigens by selecting phage antibody library on tumor cells in situ using laser capture microdissection. Mol. Cell. Proteomics. 5, 2364–2373). Full-length human IgG molecules derived from macropinocytosing phage antibodies retained the ability to internalize via macropinocytosis, validating our screening strategy. The target antigen for a cross-species binding antibody with a highly

  6. High-content analysis of antibody phage-display library selection outputs identifies tumor selective macropinocytosis-dependent rapidly internalizing antibodies.

    Science.gov (United States)

    Ha, Kevin D; Bidlingmaier, Scott M; Zhang, Yafeng; Su, Yang; Liu, Bin

    2014-12-01

    Many forms of antibody-based targeted therapeutics, including antibody drug conjugates, utilize the internalizing function of the targeting antibody to gain intracellular entry into tumor cells. Ideal antibodies for developing such therapeutics should be capable of both tumor-selective binding and efficient endocytosis. The macropinocytosis pathway is capable of both rapid and bulk endocytosis, and recent studies have demonstrated that it is selectively up-regulated by cancer cells. We hypothesize that receptor-dependent macropinocytosis can be achieved using tumor-targeting antibodies that internalize via the macropinocytosis pathway, improving potency and selectivity of the antibody-based targeted therapeutic. Although phage antibody display libraries have been utilized to find antibodies that bind and internalize to target cells, no methods have been described to screen for antibodies that internalize specifically via macropinocytosis. We hereby describe a novel screening strategy to identify phage antibodies that bind and rapidly enter tumor cells via macropinocytosis. We utilized an automated microscopic imaging-based, High Content Analysis platform to identify novel internalizing phage antibodies that colocalize with macropinocytic markers from antibody libraries that we have generated previously by laser capture microdissection-based selection, which are enriched for internalizing antibodies binding to tumor cells in situ residing in their tissue microenvironment (Ruan, W., Sassoon, A., An, F., Simko, J. P., and Liu, B. (2006) Identification of clinically significant tumor antigens by selecting phage antibody library on tumor cells in situ using laser capture microdissection. Mol. Cell. Proteomics. 5, 2364-2373). Full-length human IgG molecules derived from macropinocytosing phage antibodies retained the ability to internalize via macropinocytosis, validating our screening strategy. The target antigen for a cross-species binding antibody with a highly active

  7. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  8. Design and production of conjugate vaccines againstS.Paratyphi Ausing an O-linked glycosylation system in vivo.

    Science.gov (United States)

    Sun, Peng; Pan, Chao; Zeng, Ming; Liu, Bo; Liang, Haoyu; Wang, Dongshu; Liu, Xiankai; Wang, Bin; Lyu, Yufei; Wu, Jun; Zhu, Li; Wang, Hengliang

    2018-01-01

    Enteric fever, mainly caused by Salmonella enterica serovar Paratyphi A , remains a common and serious infectious disease worldwide. As yet, there are no licensed vaccines against S . Paratyphi A . Biosynthesis of conjugate vaccines has become a promising approach against bacterial infection. However, the popular biosynthetic strategy using N-linked glycosylation systems does not recognize the specialized O-polysaccharide structure of S . Paratyphi A . Here, we describe an O-linked glycosylation approach, the only currently available glycosylation system suitable for an S . Paratyphi A conjugate vaccine. We successfully generated a recombinant S . Paratyphi A strain with a longer O-polysaccharide chain and transformed the O-linked glycosylation system into the strain. Thus, we avoided the need for construction of an O-polysaccharide expression vector. In vivo assays indicated that this conjugate vaccine could evoke IgG1 antibody to O-antigen of S . Paratyphi A strain CMCC 50973 and elicit bactericidal activity against S . Paratyphi A strain CMCC 50973 and five other epidemic strains. Furthermore, we replaced the peptides after the glycosylation site (Ser) with an antigenic peptide (P2). The results showed that the anti-lipopolysaccharide antibody titer, bactericidal activity of serum, and protective effect during animal challenge could be improved, indicating a potential strategy for further vaccine design. Our system provides an easier and more economical method for the production of S . Paratyphi A conjugate vaccines. Modification of the glycosylation site sequon provides a potential approach for the development of next-generation "precise conjugate vaccines."

  9. Quantum dot nanoparticle conjugation, characterization, and applications in neuroscience

    Science.gov (United States)

    Pathak, Smita

    Quantum dot are semiconducting nanoparticles that have been used for decades in a variety of applications such as solar cells, LEDs and medical imaging. Their use in the last area, however, has been extremely limited despite their potential as revolutionary new biological labeling tools. Quantum dots are much brighter and more stable than conventional fluorophores, making them optimal for high resolution imaging and long term studies. Prior work in this area involves synthesizing and chemically conjugating quantum dots to molecules of interest in-house. However this method is both time consuming and prone to human error. Additionally, non-specific binding and nanoparticle aggregation currently prevent researchers from utilizing this system to its fullest capacity. Another critical issue that has not been addressed is determining the number of ligands bound to nanoparticles, which is crucial for proper interpretation of results. In this work, methods to label fixed cells using two types of chemically modified quantum dots are studied. Reproducible non-specific artifact labeling is consistently demonstrated if antibody-quantum dot conditions are less than optimal. In order to explain this, antibodies bound to quantum dots were characterized and quantified. While other groups have qualitatively characterized antibody functionalized quantum dots using TEM, AFM, UV spectroscopy and gel electrophoresis, and in some cases have reported calculated estimates of the putative number of total antibodies bound to quantum dots, no quantitative experimental results had been reported prior to this work. The chemical functionalization and characterization of quantum dot nanocrystals achieved in this work elucidates binding mechanisms of ligands to nanoparticles and allows researchers to not only translate our tools to studies in their own areas of interest but also derive quantitative results from these studies. This research brings ease of use and increased reliability to

  10. DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

    DEFF Research Database (Denmark)

    2004-01-01

    Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

  11. Catalytic enantioselective conjugate addition with Grignard reagents

    NARCIS (Netherlands)

    Lopez, Fernando; Minnaard, Adriaan J.; Feringa, Ben L.

    In this Account, recent advances in catalytic asymmetric conjugate addition of Grignard reagents are discussed. Synthetic methodology to perform highly enantioselective Cu-catalyzed conjugate addition of Grignard reagents to cyclic enones with ee's up to 96% was reported in 2004 from our

  12. Tales of conjugation and sex pheromones

    Science.gov (United States)

    2011-01-01

    This review covers highlights of the author's experience becoming and working as a plasmid biologist. The account chronicles a progression from studies of ColE1 DNA in Escherichia coli to Gram-positive bacteria with an emphasis on conjugation in enterococci. It deals with gene amplification, conjugative transposons and sex pheromones in the context of bacterial antibiotic resistance. PMID:22016844

  13. Bio-Conjugates for Nanoscale Applications

    DEFF Research Database (Denmark)

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  14. Preconditioning the modified conjugate gradient method ...

    African Journals Online (AJOL)

    In this paper, the convergence analysis of the conventional conjugate Gradient method was reviewed. And the convergence analysis of the modified conjugate Gradient method was analysed with our extension on preconditioning the algorithm. Convergence of the algorithm is a function of the condition number of M-1A.

  15. Singularities and Conjugate Points in FLRW Spacetimes

    NARCIS (Netherlands)

    Lam, Huibert het; Prokopec, Tom

    2017-01-01

    Conjugate points play an important role in the proofs of the singularity theorems of Hawking and Penrose. We examine the relation between singularities and conjugate points in FLRW spacetimes with a singularity. In particular we prove a theorem that when a non-comoving, non-spacelike geodesic in a

  16. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  17. The Conjugate Acid-Base Chart.

    Science.gov (United States)

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  18. A partner monoclonal antibody to Moab 730 kills 100% of DU145 ...

    Indian Academy of Sciences (India)

    Prakash

    cytolytic to androgen-independent DU145 and PC3 human prostatic carcinoma cells; Prostate 46 207–213. Vyas H K, Pal R, Vishwakarma R, Lohiya N K and Talwar G P 2009. Selective killing of leukemia and lymphoma cells expressing ectopically hCGβ by a conjugate of curcumin with an antibody against hCGβ subunit ...

  19. Approximate error conjugation gradient minimization methods

    Science.gov (United States)

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  20. Immunogenicity of a combination vaccine containing pneumococcal conjugates and meningococcal PorA OMVs.

    Science.gov (United States)

    van den Dobbelsteen, Germie P J M; van Dijken, Harry H; Pillai, Subramonia; van Alphen, Loek

    2007-03-22

    The pre-clinical immunogenicity of a combination vaccine containing 13-valent pneumococcal conjugate (13vPnC) vaccine (serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F conjugated to CRM197) and nine-valent meningococcal B PorA vaccine (NonaMen; serosubtypes P1.7,16; P1.5-1,2-2; P1.19,15-1; P1.5-2,10; P1.12-1,13; P1.7-2,4; P1.22,14; P1.7-1,1 and P1.18-1,3,6), and any potential immunological interference between pneumococcal and MenB components of the vaccine were evaluated. NIH mice were immunized twice subcutaneously with the vaccines combined in one syringe, or given individually. Combining 13vPnC vaccine with NonaMen vaccine in one syringe had no negative effect on the induced antibody response against any MenB serosubtypes compared to separate injection of the vaccines, and the anti-pneumococcal antibody responses were enhanced. Furthermore, co-administration of the combination vaccine with a combined diphtheria/tetanus/acellular pertussis/inactivated poliomyelitis vaccine/Haemophilus influenzae type b-TT conjugate (DTaP/IPV-Hib) vaccine to New Zealand white rabbits at a different injection site did not affect the anti-pneumococcal polysaccharide and anti-PorA antibody titres. We conclude that no immunological interference was observed by combined administration of pneumococcal conjugate and meningococcal B vaccines in one syringe.

  1. Conjugate and polysaccharide pneumococcal vaccines do not improve initial response of the polysaccharide vaccine in HIV-infected adults.

    Science.gov (United States)

    Peñaranda, Maria; Payeras, Antoni; Cambra, Ana; Mila, Joan; Riera, Melcior

    2010-05-15

    This is a randomized trial to compare the immunoglobulin G response and the antibody avidity after two pneumococcal vaccinations, conjugated pneumococcal vaccine (CPV) and polysaccharide pneumococcal vaccine (PPV) 4 weeks after vs. PPV alone in 202 HIV-infected adults. There were no differences in the two strategies, either in the percentage of immunoglobulin G two-fold increase for the CPV included serotypes or immunoglobulin G two-fold increase, reaching the level of 1 microg/ml except for serotype 23F (26% responded after conjugated pneumococcal vaccine + PPV vs. 14% after PPV). No avidity increases were seen in any strategy.

  2. Influence of prevaccination immunity on the human B-lymphocyte response to a Haemophilus influenzae type b conjugate vaccine

    DEFF Research Database (Denmark)

    Barington, T; Kristensen, K; Henrichsen, J

    1991-01-01

    of Haemophilus influenzae type b capsular polysaccharide (PRP) and diphtheria toxoid (DT), and the response was related to the prevaccination levels of PRP and DT antibodies. Positive correlations were found between increases in plasma PRP (median, 32.0 micrograms/ml) and DT (1.14 IU/ml) antibodies and numbers......The purpose of this study was to investigate whether preexisting immunity to components of a polysaccharide-protein conjugate influences the B-lymphocyte response to vaccination with the conjugate. Thirty-two healthy adults were vaccinated once or twice with a conjugate (PRP-D) consisting...... of circulating PRP and DT antibody-secreting cells (AbSC) (postvaccination days 6 to 9). The B-cell responses (antibody response and AbSC) to both PRP and DT correlated positively with prevaccination levels of anti-DT. DT AbSC appeared earlier (peak, day 7) than PRP AbSC (peak, day 8). Individuals whose PRP Ab...

  3. A Polar Sulfamide Spacer Significantly Enhances the Manufacturability, Stability, and Therapeutic Index of Antibody–Drug Conjugates

    Directory of Open Access Journals (Sweden)

    Jorge M. M. Verkade

    2018-02-01

    Full Text Available Despite tremendous efforts in the field of targeted cancer therapy with antibody–drug conjugates (ADCs, attrition rates have been high. Historically, the priority in ADC development has been the selection of target, antibody, and toxin, with little focus on the nature of the linker. We show here that a short and polar sulfamide spacer (HydraSpace™, AE Oss, The Netherland positively impacts ADC properties in various ways: (a efficiency of conjugation; (b stability; and (c therapeutic index. Different ADC formats are explored in terms of drug-to-antibody ratios (DAR2, DAR4 and we describe the generation of a DAR4 ADC by site-specific attachment of a bivalent linker–payload construct to a single conjugation site in the antibody. A head-to-head comparison of HydraSpace™-containing DAR4 ADCs to marketed drugs, derived from the same antibody and toxic payload components, indicated a significant improvement in both the efficacy and safety of several vivo models, corroborated by in-depth pharmacokinetic analysis. Taken together, HydraSpace™ technology based on a polar sulfamide spacer provides significant improvement in manufacturability, stability, and ADC design, and is a powerful platform to enable next-generation ADCs with enhanced therapeutic index.

  4. Development and Use of a Serum Bactericidal Assay Using Pooled Human Complement To Assess Responses to a Meningococcal Group A Conjugate Vaccine in African Toddlers

    OpenAIRE

    Bash, Margaret C.; Lynn, Freyja; Mocca, Brian; Borrow, Ray; Findlow, Helen; Hassan-King, Musa; Preziosi, Marie-Pierre; Idoko, Olubukola; Sow, Samba; Kulkarni, Prasad; LaForce, F. Marc

    2014-01-01

    A meningococcal group A polysaccharide (PS) conjugate vaccine (PsA-TT) has been developed for African countries affected by epidemic meningitis caused by Neisseria meningitidis. Complement-mediated serum bactericidal antibody (SBA) assays are used to assess protective immune responses to meningococcal vaccination. Human complement (hC′) was used in early studies demonstrating antibody-mediated protection against disease, but it is difficult to obtain and standardize. We developed and evaluate...

  5. Monoclonal antibodies to apolipoprotein AI: generation and characterization.

    Science.gov (United States)

    Falero, G; Rodriguez, I; Rojas, A

    1993-01-01

    BALB/c mice were immunized with apolipoprotein (apo AI)--high density lipoprotein (HDL) conjugate. By polyethylene glycol-induced fusion of isolated spleen cells with the myeloma cell line P3 X63 Ag8 6.5.3, three different hybridomas were obtained and characterized. Two of them were found to secrete antibodies of the IgG2a subclass, whereas the third produced antibodies of the IgG1 type. Binding capacities to 125I-apo AI and 125I-HDL were higher than 90% in all cases. The isolated antibodies recognize independent epitopes on the apo AI molecule and bind isolated HDL and serum-HDL with different affinities.

  6. The mechanism of the photoluminescence changes in bio-conjugated CdSe/ZnS quantum dots

    Science.gov (United States)

    Borkovska, L.; Korsunska, N.; Stara, T.; Kolomys, O.; Strelchuk, V.; Rachkov, O.; Kryshtab, T.

    2013-09-01

    The change of the photoluminescence (PL) and optical characteristics in non-conjugated and conjugated with S6K2 antibody CdSe/ZnS core/shell quantum dots (QDs) during storage in air has been studied by the conventional PL, micro-PL and micro-Raman techniques. The QDs dried on a crystalline Si substrate were kept in the darkness and under illumination. In the PL spectra, the storage resulted in a blue shift of PL peak position, in the increasing of the full width at a half maximum (FWHM) of the PL band and in the decreasing of the PL intensity. In the Raman spectra, the shift of the CdSe LO peak position to the low frequency region and the increasing of its FWHM were observed. The transformations in the PL and optical characteristics correlate with each other and are found to be the largest in bio-conjugated QDs stored under illumination. The increase of the light intensity accelerated the changes occurred during storage. An oxidation of the QD core, which decreases the QD size, is supposed to be responsible for observed transformations. The bio-conjugation is assumed to promote QD oxidation that results in different PL peak position in stored non-conjugated and bio-conjugated QDs. The mechanism of the effect is discussed.

  7. Development of Antibody–Drug Conjugates Using DDS and Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Masahiro Yasunaga

    2017-09-01

    Full Text Available Antibody-drug conjugate (ADC, as a next generation of antibody therapeutics, is a combination of an antibody and a drug connected via a specialized linker. ADC has four action steps: systemic circulation, the enhanced permeability and retention (EPR effect, penetration within the tumor tissue, and action on cells, such as through drug delivery system (DDS drugs. An antibody with a size of about 10 nm has the same capacity for passive targeting as some DDS carriers, depending on the EPR effect. In addition, some antibodies are capable of active targeting. A linker is stable in the bloodstream but should release drugs efficiently in the tumor cells or their microenvironment. Thus, the linker technology is actually a typical controlled release technology in DDS. Here, we focused on molecular imaging. Fluorescent and positron emission tomography (PET imaging is useful for the visualization and evaluation of antibody delivery in terms of passive and active targeting in the systemic circulation and in tumors. To evaluate the controlled release of the ADC in the targeted area, a mass spectrometry imaging (MSI with a mass microscope, to visualize the drug released from ADC, was used. As a result, we succeeded in confirming the significant anti-tumor activity of anti-fibrin, or anti-tissue factor-ADC, in preclinical settings by using DDS and molecular imaging.

  8. TAT peptide and its conjugates: proteolytic stability.

    Science.gov (United States)

    Grunwald, Jacob; Rejtar, Tomas; Sawant, Rupa; Wang, Zhouxi; Torchilin, Vladimir P

    2009-08-19

    The proteolytic cleavage of TATp, TATp-PEG(1000)-PE conjugate (TATp-conjugate), and TATp as TATp-conjugate in mixed micelles made of TATp-conjugate and PEG(5000)-PE (2.5% mol of TATp-conjugate, TATp-Mic) were studied by HPLC with fluorescent detection using fluorenylmethyl chloroformate (FMOC) labeling and by MALDI-TOF MS analysis. The cleavage kinetics were analyzed in human blood plasma and in trypsin-containing phosphate buffered saline (PBS), pH 7.4, to simulate the proteolytic activity of human plasma. The trypsinolysis of free TATp, TATp-conjugate, and TATp-Mic revealed that the main initial fragmentation is an endocleavage at the carboxyl terminus resulting in an Arg-Arg (RR) dimer. The trypsinolysis followed pseudo-first-order kinetics. The cleavage of the free TATp was relatively fast with a half-life of a few minutes (t(1/2) ∼ 3.5 min). The TATp-conjugate showed more stability with about a 3-fold increase in half-life (t(1/2) ∼ 10 min). TATp in TATp-Mic was highly protected against proteolysis with an over 100-fold increase in half-life (t(1/2) ∼ 430 min). The shielding of TATp by PEG moieties in the proposed TATp-Mic is of great importance for its potential use as a cell-penetrating moiety for multifunctional "smart" drug delivery systems with detachable PEG.

  9. Characterization of antibodies to dihydrothymine, a radiolysis product of DNA

    International Nuclear Information System (INIS)

    Hubbard, K.; Ide, H.; Erlanger, B.F.; Wallace, S.S.

    1989-01-01

    Antibodies to dihydrothymine were elicited by immunizing rabbits with dihydrothymidine monophosphate conjugated by carbodiimide to BSA. By use of an ELISA assay, the antibodies produced were found to be specific for dihydrothymine. Hapten inhibition studies showed that dihydrothymidine monophosphate was 3 orders of magnitude more effective as an inhibitor than thymidine monophosphate and 4 orders of magnitude more effective than thymidine glycol monophosphate. With DNA containing dihydrothymine, antibody reactivity was observed at 20 fmol of dihydrothymine, which is approximately 0.1 dihydrothymine per 10,000 bases. Thus, the assay is very sensitive. The antibody reacted with denatured DNA containing dihydrothymine but not with native DNA containing this lesion. The antibody was used for measurement of in vivo incorporation of dihydrothymidine in wild-type Escherichia coli or mutants defective in their ability to remove dihydrothymine from DNA or in the de novo synthesis of thymidylate. Lastly, antibodies to dihydrothymine were use to quantitate the formation of dihydrothymine in DNA X-irradiated under N2. Production of dihydrothymine in irradiated DNA correlated with the level of reducing species produced by X-rays, and dihydrothymine was produced preferentially in irradiated single-stranded or denatured DNA as compared to irradiated duplex DNA

  10. Antibodies Against Melanin

    African Journals Online (AJOL)

    1973-01-06

    Jan 6, 1973 ... Departments of Internal Medicine and Anatomical Pathology, University of Stellenbosch and MRC. Pigment Metabolism Research Unit, ... at the production of antibodies against natural melanoprotein. and a consideration of our negative .... the random polymerization of several monomers, antibody formed ...

  11. Recombinant renewable polyclonal antibodies.

    Science.gov (United States)

    Ferrara, Fortunato; D'Angelo, Sara; Gaiotto, Tiziano; Naranjo, Leslie; Tian, Hongzhao; Gräslund, Susanne; Dobrovetsky, Elena; Hraber, Peter; Lund-Johansen, Fridtjof; Saragozza, Silvia; Sblattero, Daniele; Kiss, Csaba; Bradbury, Andrew R M

    2015-01-01

    Only a small fraction of the antibodies in a traditional polyclonal antibody mixture recognize the target of interest, frequently resulting in undesirable polyreactivity. Here, we show that high-quality recombinant polyclonals, in which hundreds of different antibodies are all directed toward a target of interest, can be easily generated in vitro by combining phage and yeast display. We show that, unlike traditional polyclonals, which are limited resources, recombinant polyclonal antibodies can be amplified over one hundred million-fold without losing representation or functionality. Our protocol was tested on 9 different targets to demonstrate how the strategy allows the selective amplification of antibodies directed toward desirable target specific epitopes, such as those found in one protein but not a closely related one, and the elimination of antibodies recognizing common epitopes, without significant loss of diversity. These recombinant renewable polyclonal antibodies are usable in different assays, and can be generated in high throughput. This approach could potentially be used to develop highly specific recombinant renewable antibodies against all human gene products.

  12. Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy

    Directory of Open Access Journals (Sweden)

    Wiebke Sihver

    2014-03-01

    Full Text Available The epidermal growth factor receptor (EGFR has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment.

  13. A Review of Therapeutic Aptamer Conjugates with Emphasis on New Approaches

    Directory of Open Access Journals (Sweden)

    John G. Bruno

    2013-03-01

    Full Text Available The potential to emulate or enhance antibodies with nucleic acid aptamers while lowering costs has prompted development of new aptamer-protein, siRNA, drug, and nanoparticle conjugates. Specific focal points of this review discuss DNA aptamers covalently bound at their 3' ends to various proteins for enhanced stability and greater pharmacokinetic lifetimes in vivo. The proteins can include Fc tails of IgG for opsonization, and the first component of complement (C1q to trigger complement-mediated lysis of antibiotic-resistant Gram negative bacteria, cancer cells and possibly some parasites during vulnerable stages. In addition, the 3' protein adduct may be a biotoxin, enzyme, or may simply be human serum albumin (HSA or a drug known to bind HSA, thereby retarding kidney and other organ clearance and inhibiting serum exonucleases. In this review, the author summarizes existing therapeutic aptamer conjugate categories and describes his patented concept for PCR-based amplification of double-stranded aptamers followed by covalent attachment of proteins or other agents to the chemically vulnerable overhanging 3' adenine added by Taq polymerase. PCR amplification of aptamers could dramatically lower the current $2,000/gram cost of parallel chemical oligonucleotide synthesis, thereby enabling mass production of aptamer-3'-protein or drug conjugates to better compete against expensive humanized monoclonal antibodies.

  14. Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

    Science.gov (United States)

    Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

    2016-04-01

    Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be

  15. [Immunochemical Detection of Azospirilla in Soil with Genus-Specific Antibodies].

    Science.gov (United States)

    Shirokov, A A; Krasov, A I; Selivanov, N Yu; Burygin, G L; Shchegolev, S Yu; Matora, L Yu

    2015-01-01

    Immunoelectrophoresis and immunodiffusion analysis with antibodies to whole intact cells of the type strain of nitrogen-fixing soil bacteria Azospirillum brasilense Sp7 revealed at least three conservative surface immunogenic proteins of azospirilla. Cross-reactions with these proteins made it possible to use the above antibodies for detection of azospirilla as a genus-specific probe conjugated with horseradish peroxidase as an enzymatic label. Direct immune-enzyme analysis of soil suspensions (typical chernozem, Saratov oblast) confirmed applicability of the conjugates based on genus-specific antibodies to the surface proteins of azospirilla for direct detection of this bacterial genus in environmental samples. These results provide a basis for broad application of this method for analysis of Azospirillum occurrence in soil.

  16. Synthesis of Polyclonal Antibodies against Aflatoxin B1

    Directory of Open Access Journals (Sweden)

    Wiyogo Prio Wicaksono

    2015-09-01

    Full Text Available Polyclonal antibodies of aflatoxin B1 were successfully produced from New Zealand White female rabbits after immunization by the hapten of aflatoxin B1-carboxymethyl hydroxylamine hemihydrochloride (AFB1-CMO conjugated with bovine serum albumin (BSA as the antigen. The hapten was synthesized using the carbodiimide method with CMO as a linker. Absorption peaks at 362, 264, and 218 nm were observed as a result of characterization with UV-Vis spectroscopy, while IR spectroscopy showed peaks at 3448 cm-1 and 1642 cm-1 attributable to the hydroxyl and nitrile groups, respectively. Furthermore, mass spectrometry showed fragmentation at the m/z of 386, 368.2, and 310, which confirms that the hapten of AFB1-CMO was successfully synthesized. The hapten was then conjugated with BSA to serve as an antigen of AFB1 when it was injected into the rabbits. The specificity of the antigen towards its antibody and the confirmation of hapten-BSA conjugation were characterized using the dot blot immunoassay, which showed a BSA concentration of 1.74 mg/mL. Two weeks after the primary immunization by its antigen, agar gel precipitation testing showed that the rabbit blood serum had positive results for polyclonal antibodiest against AFB1 with the highest concentration of antibodiest of 2.19 mg/mL.

  17. Antibody engineering: methods and protocols

    National Research Council Canada - National Science Library

    Chames, Patrick

    2012-01-01

    "Antibody Engineering: Methods and Protocols, Second Edition was compiled to give complete and easy access to a variety of antibody engineering techniques, starting from the creation of antibody repertoires and efficient...

  18. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test; Insulin resistance - insulin antibodies; Diabetes - insulin antibodies ... You appear to have an allergic response to insulin Insulin no longer seems to control your diabetes

  19. Rapid optical imaging of human breast tumour xenografts using anti-HER2 VHHs site-directly conjugated to IRDye 800CW for image-guided surgery

    NARCIS (Netherlands)

    Kijanka, Marta; Warnders, Frank-Jan; El Khattabi, Mohamed; Lub-de Hooge, Marjolijn; van Dam, Gooitzen M.; Ntziachristos, Vasilis; de Vries, Liesbeth; Oliveira, Sabrina; van Bergen en Henegouwen, Paul M. P.

    2013-01-01

    Purpose Molecular optical imaging using monoclonal antibodies is slow with low tumour to background ratio. We used anti-HER2 VHHs conjugated to IRDye 800CW to investigate their potential as probes for rapid optical molecular imaging of HER2-positive tumours by the determination of tumour

  20. Trastuzumab-conjugated liposome-coated fluorescent magnetic nanoparticles to target breast cancer.

    Science.gov (United States)

    Jang, Mijung; Yoon, Young Il; Kwon, Yong Soo; Yoon, Tae-Jong; Lee, Hak Jong; Hwang, Sung Il; Yun, Bo La; Kim, Sun Mi

    2014-01-01

    To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNP@m-SiO2]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNP@m-SiO2]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. The physiochemical characteristics of Lipo[MNP@m-SiO2] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNP@m-SiO2] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin®)-conjugated Lipo[MNP@m-SiO2] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. We obtained uniformly-sized and evenly distributed Lipo[MNP@m-SiO2] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNP@m-SiO2] was observed by in vitro fluorescence and MR imaging. Trastuzumab-conjugated Lipo[MNP@m-SiO2] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.

  1. Optimization of the conjugation method for a serogroup B/C meningococcal vaccine.

    Science.gov (United States)

    Fukasawa, Lucila O; Schenkman, Rocilda P F; Perciani, Catia T; Carneiro, Sylvia M; Dias, Waldely O; Tanizaki, Martha M

    2006-11-01

    A conjugate meningococcal vaccine against serogroup B/C consisting of capsular PS (polysaccharide) from serogroup C conjugated to OMV (outer membrane vesicle) from serogroup B would be a very useful vaccine in regions where there is a prevalence of both serogroups, for example in Brazil. For this purpose, the conjugation method that uses ADHy (adipic acid dihydrazide) as spacer and a carbodi-imide derivative, EDAC [1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide], as catalyser was optimized looking for synthesis yield and maintenance of the antigenicity of both components. The best synthesis conditions preserving the vaccine immunogenicity resulted in a final yield of approx. 17%. Immunogenicity of the vaccine was highest when 10% of the sialic acid residues of the PS were occupied by the ADHy spacer. Sterilization of the conjugate by filtration through a 0.22-microm-pore-size membrane resulted in a low recovery of protein and PS (approximately 50%), although the vaccine immunogenicity was maintained. Using gamma irradiation on freeze-dried sample, it was possible to maintain the integrity of OMV structure and, consequently, its ability to induce bactericidal antibodies.

  2. Biosynthesis of Conjugate Vaccines Using an O-Linked Glycosylation System

    Directory of Open Access Journals (Sweden)

    Chao Pan

    2016-04-01

    Full Text Available Conjugate vaccines are known to be one of the most effective and safest types of vaccines against bacterial pathogens. Previously, vaccine biosynthesis has been performed by using N-linked glycosylation systems. However, the structural specificity of these systems for sugar substrates has hindered their application. Here, we report a novel protein glycosylation system (O-linked glycosylation via Neisseria meningitidis that can transfer virtually any glycan to produce a conjugate vaccine. We successfully established this system in Shigella spp., avoiding the construction of an expression vector for polysaccharide synthesis. We further found that different protein substrates can be glycosylated using this system and that the O-linked glycosylation system can also effectively function in other Gram-negative bacteria, including some strains whose polysaccharide structure was not suitable for conjugation using the N-linked glycosylation system. The results from a series of animal experiments show that the conjugate vaccine produced by this O-linked glycosylation system offered a potentially protective antibody response. Furthermore, we elucidated and optimized the recognition motif, named MOOR, for the O-glycosyltransferase PglL. Finally, we demonstrated that the fusion of other peptides recognized by major histocompatibility complex class II around MOOR had no adverse effects on substrate glycosylation, suggesting that this optimized system will be useful for future vaccine development. Our results expand the glycoengineering toolbox and provide a simpler and more robust strategy for producing bioconjugate vaccines against a variety of pathogens.

  3. Transtuzumab-conjugated liposome-coated fluorscent magnetic namoparticles to target breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Mi Jung; Lee, Hak Jong; Hwang, Sung Il; Yun, Bo La; Kim, Sun Mi [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Yoon, Young Il; Kwon, Yong Soo [Nanoimaging and Therapy Research Center, Institute of Nanoconvergence, Advanced Institutes of Convergence Technology, Seoul National University, Suwon (Korea, Republic of); Yoon, Tae Jong [NanoBio Materials Chemistry Lab., Dept. of Applied Bioscience, CHA University, Pocheon (Korea, Republic of)

    2014-08-15

    To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNPm-SiO{sub 2}]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNPm-SiO{sub 2}]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. The physiochemical characteristics of Lipo[MNPm-SiO{sub 2}] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNPm-SiO{sub 2}] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin)-conjugated Lipo[MNPm-SiO{sub 2}] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. We obtained uniformly-sized and evenly distributed Lipo[MNPm-SiO{sub 2}] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNPm-SiO{sub 2}] was observed by in vitro fluorescence and MR imaging. Trastuzumab-conjugated Lipo[MNPm-SiO{sub 2}] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.

  4. Conjugated Polymers and Oligomers: Structural and Soft Matter Aspects

    DEFF Research Database (Denmark)

    conjugated polymer backbone, water soluble conjugated polyelectrolytes and surfactants, conjugated molecules and biomolecules and DNA and the advanced use of synchrotron radiation and electron microscopy to find out structural details in conjugated molecule films and devices as well as under ambient...

  5. Nature of immobilization surface affects antibody specificity to placental alkaline phosphatase.

    Science.gov (United States)

    Kumar, Mukesh; Khan, Imran; Sinha, Subrata

    2015-01-01

    Retention of native conformation of immobilized protein is essential for various applications including selection and detection of specific recombinant antibodies (scFvs). Placental alkaline phosphatase (PAP), an onco-fetal antigen expressed on the surface of several tumors, was immobilized on supermagnetic particles for selection of recombinant antibodies from a human phage display antibody library. The isolated antibodies were found to be cross-reactive to either of the isozymes of alkaline phosphatase, i.e., bone alkaline phosphatase (BAP) or intestinal alkaline phosphatase (IAP) and could not be used for tumor targeting. A specific anti-PAP monoclonal antibody H17E2 was tested for retention of specificity under these conditions. Binding of the antibody to magnetic beads conjugated IAP and BAP along with PAP and the ability of the two isozymes to inhibit its binding to PAP depicted the loss of isozyme specificity of the antibody. However, the antibody retained its specificity to PAP immobilized on polyvinyl chloride (PVC) surface. Enzyme activity was observed on both surfaces. This demonstrates that nature of immobilization may affect antigen-antibody binding in subtle ways, resulting in alteration of conformation of the epitopes. This may have consequences for determining the specificity of antibody binding for proteins that share a high degree of homology.

  6. Oligonucleotides conjugated to short lysine chains.

    Science.gov (United States)

    Winkler, Johannes; Urban, Ernst; Noe, Christian R

    2005-01-01

    A new method for synthesizing oligonucleotide peptide conjugates by an in-line approach is presented. A phosphorothioate oligonucleotide with the sequence of bcl-2 targeted Oblimersen by employing a modified 2'-amino-2'-desoxy-uridine nucleotide bearing a succinyl linker at the 2' position was prepared. The carboxyl group was protected for solid-phase synthesis as the benzyl ester. Ester cleavage was afforded by a phase transfer reaction using palladium nanoparticles as catalyst and cyclohexadiene as hydrogen donor. Short tails of up to three lysyl residues were conjugated to the oligonucleotide by an inverse stepwise peptide synthesis. The conjugates were characterized by HPLC, mass spectrometry, and circular dichroism. Influence of lysyl tails on CD spectra were minimal. Melting profiles revealed only minimal destabilizing effects on duplexes by conjugation of peptides.

  7. Stochastic differential equations used to model conjugation

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo

    be split into measurement noise and system noise. The system noise is used to compensate for those biological processes not explicitly described by the model. Many authors model conjugation by a simple mass action model first proposed by Levin et al. (1979). Also Michaelis-Menten dependence...... by an experiment conducted with E. faecium. In addition, we suggest that a 3rd order time-delay must be included in the model to account for the delay before a newly conjugated plasmid is expressed. A ML estimate of the parameters based on experimental data is found using the software CTSM. The conjugation rate......Stochastic differential equations (SDEs) are used to model horizontal transfer of antibiotic resis- tance by conjugation. The model describes the concentration of donor, recipient, transconjugants and substrate. The strength of the SDE model over the traditional ODE models is that the noise can...

  8. Deciphering conjugative plasmid permissiveness in wastewater microbiomes

    DEFF Research Database (Denmark)

    Jacquiod, Samuel Jehan Auguste; Brejnrod, Asker Daniel; Milani, Stefan Morberg

    2017-01-01

    Wastewater treatment plants (WWTPs) are designed to robustly treat polluted water. They are characterized by ceaseless flows of organic, chemical and microbial matter, followed by treatment steps before environmental release. WWTPs are hotspots of horizontal gene transfer between bacteria via...... conjugative plasmids, leading to dissemination of potentially hazardous genetic material such as antimicrobial resistance genes (AMRGs). While current focus is on the threat of AMRGs spreading and their environmental maintenance, conjugative plasmid transfer dynamics within and between bacterial communities...... still remains largely uncharted. Furthermore, current in vitro methods used to assess conjugation in complex microbiomes do not include in situ behaviours of recipient cells, resulting in partial understanding of transfers. We investigated the in vitro conjugation capacities of WWTP microbiomes from...

  9. Design and Application of Antimicrobial Peptide Conjugates

    Directory of Open Access Journals (Sweden)

    Andre Reinhardt

    2016-05-01

    Full Text Available Antimicrobial peptides (AMPs are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, but also peptide conjugates containing AMPs, have come more and more into the focus of research during the last few years. Within this article, recent work on AMP conjugates is reviewed. Different aspects will be highlighted as a combination of AMPs with antibiotics or organometallic compounds aiming to increase antibacterial activity or target selectivity, conjugation with photosensitizers for improving photodynamic therapy (PDT or the attachment to particles, to name only a few. Owing to the enormous resonance of antimicrobial conjugates in the literature so far, this research topic seems to be very attractive to different scientific fields, like medicine, biology, biochemistry or chemistry.

  10. Monoclonal antibody "gold rush".

    Science.gov (United States)

    Maggon, Krishan

    2007-01-01

    The market, sales and regulatory approval of new human medicines, during the past few years, indicates increasing number and share of new biologics and emergence of new multibillion dollar molecules. The global sale of monoclonal antibodies in 2006 were $20.6 billion. Remicade had annual sales gain of $1 billion during the past 3 years and five brands had similar increase in 2006. Rituxan with 2006 sales of $4.7 billion was the best selling monoclonal antibody and biological product and the 6th among the top selling medicinal brand. It may be the first biologic and monoclonal antibody to reach $10 billion annual sales in the near future. The strong demand from cancer and arthritis patients has surpassed almost all commercial market research reports and sales forecast. Seven monoclonal antibody brands in 2006 had sales exceeding $1 billion. Humanized or fully human monoclonal antibodies with low immunogenicity, enhanced antigen binding and reduced cellular toxicity provide better clinical efficacy. The higher technical and clinical success rate, overcoming of technical hurdles in large scale manufacturing, low cost of market entry and IND filing, use of fully human and humanized monoclonal antibodies has attracted funds and resources towards R&D. Review of industry research pipeline and sales data during the past 3 years indicate a real paradigm shift in industrial R&D from pharmaceutical to biologics and monoclonal antibodies. The antibody bandwagon has been joined by 200 companies with hundreds of new projects and targets and has attracted billions of dollars in R&D investment, acquisitions and licensing deals leading to the current Monoclonal Antibody Gold Rush.

  11. Antibody-based PET imaging of amyloid beta in mouse models of Alzheimer's disease.

    Science.gov (United States)

    Sehlin, Dag; Fang, Xiaotian T; Cato, Linda; Antoni, Gunnar; Lannfelt, Lars; Syvänen, Stina

    2016-02-19

    Owing to their specificity and high-affinity binding, monoclonal antibodies have potential as positron emission tomography (PET) radioligands and are currently used to image various targets in peripheral organs. However, in the central nervous system, antibody uptake is limited by the blood-brain barrier (BBB). Here we present a PET ligand to be used for diagnosis and evaluation of treatment effects in Alzheimer's disease. The amyloid β (Aβ) antibody mAb158 is radiolabelled and conjugated to a transferrin receptor antibody to enable receptor-mediated transcytosis across the BBB. PET imaging of two different mouse models with Aβ pathology clearly visualize Aβ in the brain. The PET signal increases with age and correlates closely with brain Aβ levels. Thus, we demonstrate that antibody-based PET ligands can be successfully used for brain imaging.

  12. Energetic Tuning in Spirocyclic Conjugated Polymers

    OpenAIRE

    Hugo Bronstein; Frank D. King

    2016-01-01

    Precise control of the energy levels in a conjugated polymer is the key to allowing their exploitation in optoelectronic devices. The introduction of spirocycles into conjugated polymers has traditionally been used to enhance their solid state microstructure. Here we present a highly novel method of energetic tuning through the use of electronically active spirocyclic systems. By modifying the size and oxidation state of a heteroatom in an orthogonal spirocycle we demonstrate energetic fine t...

  13. Two-zone double phase conjugate mirror

    Science.gov (United States)

    Belić, M. R.; Vujić, D.; Sandfuchs, O.; Kaiser, F.

    2001-10-01

    An analysis of photorefractive (PR) oscillators consisting of two facing four-wave mixing regions is carried out. The threshold and operation conditions of different phase conjugate mirrors are discussed with the help of the grating action method. In particular, the threshold and the operation of the two-zone double phase conjugate mirror (DPCM) is compared with other related PR oscillators, the interconnected ring, and different connected DPCM.

  14. Rapid modification of retroviruses using lipid conjugates

    International Nuclear Information System (INIS)

    Mukherjee, Nimisha G; Le Doux, Joseph M; Andrew Lyon, L

    2009-01-01

    Methods are needed to manipulate natural nanoparticles. Viruses are particularly interesting because they can act as therapeutic cellular delivery agents. Here we examine a new method for rapidly modifying retroviruses that uses lipid conjugates composed of a lipid anchor (1,2-distearoyl-sn-glycero-3-phosphoethanolamine), a polyethylene glycol chain, and biotin. The conjugates rapidly and stably modified retroviruses and enabled them to bind streptavidin. The implication of this work for modifying viruses for gene therapy and vaccination protocols is discussed.

  15. Syntheses of conjugated polymers for photonics

    Czech Academy of Sciences Publication Activity Database

    Výprachtický, Drahomír; Cimrová, Věra; Kmínek, Ivan; Pavlačková, Petra

    2010-01-01

    Roč. 295, č. 1 (2010), s. 94-99 ISSN 1022-1360. [Prague Meetings on Macromolecules /73./ New Frontiers in Macromolecular Science: From Macromolecular Concepts of Living Matter to Polymers for Better Quality of Life. Prague, 05.07.2009-09.07.2009] R&D Projects: GA MŠk(CZ) 1M06031 Institutional research plan: CEZ:AV0Z40500505 Keywords : cis and trans isomers * conjugated polymer * conjugated polyelectrolyte Subject RIV: BM - Solid Matter Physics ; Magnetism

  16. Probing cocaine-antibody interactions in buffer and human serum.

    Science.gov (United States)

    Ramakrishnan, Muthu; Alves De Melo, Fernando; Kinsey, Berma M; Ladbury, John E; Kosten, Thomas R; Orson, Frank M

    2012-01-01

    Despite progress in cocaine immunotherapy, the kinetic and thermodynamic properties of antibodies which bind to cocaine and its metabolites are not well understood. It is also not clear how the interactions between them differ in a complex matrix such as the serum present in the human body. In the present study, we have used microscale thermophoresis (MST), isothermal titration calorimetry (ITC), and surface plasmon resonance (SPR) we have evaluated the affinity properties of a representative mouse monoclonal (mAb08) as well as those of polyclonal antibodies purified from vaccinated mouse and human patient serum. MST analysis of fluorescently tagged mAb08 binding to cocaine reveals an approximately 15 fold decrease in its equilibrium dissociation constant in 20-50% human serum compared with that in saline buffer. A similar trend was also found using enriched polyclonal antibodies purified from vaccinated mice and patient serum, for which we have used fluorescently tagged bovine serum albumin conjugated to succinyl norcocaine (BSA-SNC). This conjugate closely mimics both cocaine and the hapten used to raise these antibodies. The ITC data also revealed that cocaine has a moderate affinity of about 2 µM to 20% human serum and very little interaction with human serum albumin or nonspecific human IgG at that concentration range. In a SPR inhibition experiment, the binding of mAb08 to immobilized BSA-SNC was inhibited by cocaine and benzoylecgonine in a highly competitive manner, whereas the purified polyclonal antibodies from vaccinated humans and mice, revealed preferential selectivity to pharmacologically active cocaine but not to the inactive metabolite benzoylecgonine. We have also developed a simple binding model to simulate the challenges associated with cocaine immunotherapy using the variable quantitative and kinetic properties of the antibodies. High sensitivity calorimetric determination of antibody binding to cocaine and its metabolites provide valuable

  17. Antibody affinity maturation

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise

    surface expression of various antibody formats in the generated knockout strain. Functional scFv and scFab fragments were efficiently displayed on yeast whereas impaired chain assembly and heavy chain degradation was observed for display of full-length IgG molecules. To identify the optimal polypeptide......-antibody interface and the antibody intraface.the microenvironment and ecology of Acaryochloris and Prochloron, and in this thesis we attempted to further describe the distribution, growth characteristics and adaptive/regulatory mechanisms of these two cyanobacteria, both in their natural habitat and under defined...

  18. EGFR targeted nanobody-photosensitizer conjugates for photodynamic therapy in a pre-clinical model of head and neck cancer.

    Science.gov (United States)

    van Driel, Pieter B A A; Boonstra, Martin C; Slooter, Maxime D; Heukers, Raimond; Stammes, Marieke A; Snoeks, Thomas J A; de Bruijn, Henriette S; van Diest, Paul J; Vahrmeijer, Alexander L; van Bergen En Henegouwen, Paul M P; van de Velde, Cornelis J H; Löwik, Clemens W G M; Robinson, Dominic J; Oliveira, Sabrina

    2016-05-10

    Photodynamic therapy (PDT) induces cell death through local light activation of a photosensitizer (PS) and has been used to treat head and neck cancers. Yet, common PS lack tumor specificity, which leads to collateral damage to normal tissues. Targeted delivery of PS via antibodies has pre-clinically improved tumor selectivity. However, antibodies have long half-lives and relatively poor tissue penetration, which could limit therapeutic efficacy and lead to long photosensitivity. Here, in this feasibility study, we evaluate at the pre-clinical level a recently introduced format of targeted PDT, which employs nanobodies as targeting agents and a water-soluble PS (IRDye700DX) that is traceable through optical imaging. In vitro, the PS solely binds to cells and induces phototoxicity on cells overexpressing the epidermal growth factor receptor (EGFR), when conjugated to the EGFR targeted nanobodies. To investigate whether this new format of targeted PDT is capable of inducing selective tumor cell death in vivo, PDT was applied on an orthotopic mouse tumor model with illumination at 1h post-injection of the nanobody-PS conjugates, as selected from quantitative fluorescence spectroscopy measurements. In parallel, and as a reference, PDT was applied with an antibody-PS conjugate, with illumination performed 24h post-injection. Importantly, EGFR targeted nanobody-PS conjugates led to extensive tumor necrosis (approx. 90%) and almost no toxicity in healthy tissues, as observed through histology 24h after PDT. Overall, results show that these EGFR targeted nanobody-PS conjugates are selective and able to induce tumor cell death in vivo. Additional studies are now needed to assess the full potential of this approach to improving PDT. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Conjugation in Gram-Positive Bacteria.

    Science.gov (United States)

    Goessweiner-Mohr, Nikolaus; Arends, Karsten; Keller, Walter; Grohmann, Elisabeth

    2014-08-01

    Conjugative transfer is the most important means of spreading antibiotic resistance and virulence factors among bacteria. The key vehicles of this horizontal gene transfer are a group of mobile genetic elements, termed conjugative plasmids. Conjugative plasmids contain as minimum instrumentation an origin of transfer (oriT), DNA-processing factors (a relaxase and accessory proteins), as well as proteins that constitute the trans-envelope transport channel, the so-called mating pair formation (Mpf) proteins. All these protein factors are encoded by one or more transfer (tra) operons that together form the DNA transport machinery, the Gram-positive type IV secretion system. However, multicellular Gram-positive bacteria belonging to the streptomycetes appear to have evolved another mechanism for conjugative plasmid spread reminiscent of the machinery involved in bacterial cell division and sporulation, which transports double-stranded DNA from donor to recipient cells. Here, we focus on the protein key players involved in the plasmid spread through the two different modes and present a new secondary structure homology-based classification system for type IV secretion protein families. Moreover, we discuss the relevance of conjugative plasmid transfer in the environment and summarize novel techniques to visualize and quantify conjugative transfer in situ.

  20. Immunoglobulin and enzyme-conjugated dextran polymers enhance u-PAR staining intensity of carcinoma cells in peripheral blood smears

    DEFF Research Database (Denmark)

    Werther, K; Normark, M; Hansen, B F

    1999-01-01

    The presence of disseminated carcinoma cells in bone marrow and peripheral blood has prognostic importance in patients with carcinomas. Much evidence indicates that dissemination of tumor cells may depend on activation of a variety of degradative enzymes. A strong positive correlation has been...... phenotyping of disseminated carcinoma cells in bone marrow and peripheral blood smears. In the first step, the cells were incubated with antibodies against urokinase plasminogen activator receptor (u-PAR) and subsequently with secondary antibodies conjugated to peroxidase-labeled dextran polymers. A brown...

  1. Development of a competitive lateral flow immunoassay for progesterone: influence of coating conjugates and buffer components.

    Science.gov (United States)

    Posthuma-Trumpie, Geertruida A; Korf, Jakob; van Amerongen, Aart

    2008-11-01

    Several aspects of the development of competitive lateral flow immunoassays (LFIAs) are described. The quantitation of progesterone is taken as an example. The LFIA format consisted of a nitrocellulose membrane spotted with various progesterone conjugates as the test line. A mixture of primary antibody and secondary antibody adsorbed to colloidal carbon was used for signal generation. A digital scanner and dedicated software were used to quantitate the response. A reappraisal of the checkerboard titration, often used in the optimisation of immunoassays, is discussed. Surprisingly, the highest sensitivity of the LFIA format (IC(50) of 0.6 microg L(-1) progesterone in buffer) was achieved by using a high coating concentration of the analyte-protein conjugate and a high dilution of the antibody solution. Immediate addition of all reagents in LFIA was superior to premixing the components and allowing prereaction. Of several blocking agents tested bovine serum albumin was superior in performance, whereas the combination of ovalbumin and progesterone substantially influenced test results.

  2. Selective apoptotic killing of malignant hemopoietic cells by antibody-targeted delivery of an amphipathic peptide.

    Science.gov (United States)

    Marks, Alexandra J; Cooper, Margaret S; Anderson, Robert J; Orchard, Kim H; Hale, Geoffrey; North, Janet M; Ganeshaguru, Kanagasabai; Steele, Andrew J; Mehta, Atul B; Lowdell, Mark W; Wickremasinghe, R Gitendra

    2005-03-15

    The alpha-helical amphipathic peptide D-(KLAKLAK)2 is toxic to eukaryotic cells if internalized by a suitable targeting mechanism. We have targeted this peptide to malignant hemopoietic cells via conjugation to monoclonal antibodies, which recognize lineage-specific cell surface molecules. An anti-CD19/peptide conjugate efficiently killed 3/3 B lymphoid lines. However, an anti-CD33/peptide conjugate was cytotoxic to only one of three CD33-positive myeloid leukemia lines. The IC50 towards susceptible lines were in the low nanomolar range. Conjugates were highly selective and did not kill cells that did not express the appropriate cell surface cognate of the antibody moiety. Anti-CD19/peptide conjugates efficiently killed cells from patients with chronic lymphocytic leukemia but anti-CD33/peptide reagents were less effective against fresh acute myeloid leukemia cells. We therefore suggest that amphipathic peptides may be of value as targeted therapeutic agents for the treatment of a subset of hematologic malignancies.

  3. Conjugation of polysaccharide 6B from Streptococcus pneumoniae with pneumococcal surface protein A: PspA conformation and its effect on the immune response.

    Science.gov (United States)

    Perciani, Catia T; Barazzone, Giovana C; Goulart, Cibelly; Carvalho, Eneas; Cabrera-Crespo, Joaquin; Gonçalves, Viviane M; Leite, Luciana C C; Tanizaki, Martha M

    2013-06-01

    Despite the substantial beneficial effects of incorporating the 7-valent pneumococcal conjugate vaccine (PCV7) into immunization programs, serotype replacement has been observed after its widespread use. As there are many serotypes currently documented, the use of a conjugate vaccine relying on protective pneumococcal proteins as active carriers is a promising alternative to expand PCV coverage. In this study, capsular polysaccharide serotype 6B (PS6B) and recombinant pneumococcal surface protein A (rPspA), a well-known protective antigen from Streptococcus pneumoniae, were covalently attached by two conjugation methods. The conjugation methodology developed by our laboratory, employing 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) as an activating agent through carboxamide formation, was compared with reductive amination, a classical methodology. DMT-MM-mediated conjugation was shown to be more efficient in coupling PS6B to rPspA clade 1 (rPspA1): 55.0% of PS6B was in the conjugate fraction, whereas 24% was observed in the conjugate fraction with reductive amination. The influence of the conjugation process on the rPspA1 structure was assessed by circular dichroism. According to our results, both conjugation processes reduced the alpha-helical content of rPspA; reduction was more pronounced when the reaction between the polysaccharide capsule and rPspA1 was promoted between the carboxyl groups than the amine groups (46% and 13%, respectively). Regarding the immune response, both conjugates induced functional anti-rPspA1 and anti-PS6B antibodies. These results suggest that the secondary structure of PspA1, as well as its reactive groups (amine or carboxyl) involved in the linkage to PS6B, may not play an important role in eliciting a protective immune response to the antigens.

  4. Serum herpes simplex antibodies

    Science.gov (United States)

    ... causes cold sores (oral herpes). HSV-2 causes genital herpes. How the Test is Performed A blood sample ... person has ever been infected with oral or genital herpes . It looks for antibodies to herpes simplex virus ...

  5. Anti-sulfotyrosine antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Bertozzi, Carolyn R [Berkeley, CA; Kehoe, John [Saint Davids, PA; Bradbury, Andrew M [Santa Fe, NM

    2009-09-15

    The invention provides anti-sulfotyrosine specific antibodies capable of detecting and isolating polypeptides that are tyrosine-sulfated. The sulfotyrosine antibodies and antibody fragments of the invention may be used to discriminate between the non-sulfated and sulfated forms of such proteins, using any number of immunological assays, such ELISAs, immunoblots, Western Blots, immunoprecipitations, and the like. Using a phage-display system, single chain antibodies (scFvs) were generated and screened against tyrosine-sulfated synthetic peptide antigens, resulting in the isolation of scFvs that specifically recognize sulfotyrosine-containing peptides and/or demonstrate sulfotyrosine-specific binding in tyrosine sulfated proteins. The VH and VL genes from one such sulfotyrosine-specific scFv were employed to generate a full length, sulfotyrosine-specific immunoglobulin.

  6. Bifunctional antibodies for radioimmunotherapy.

    Science.gov (United States)

    Chatal, J F; Faivre-Chauvet, A; Bardies, M; Peltier, P; Gautherot, E; Barbet, J

    1995-04-01

    In two-step targeting technique using bifunctional antibodies, a nonradiolabeled immunoconjugate with slow uptake kinetics (several days) is initially injected, followed by a small radiolabeled hapten with fast kinetics (several hours) that binds to the bispecific immunoconjugate already taken up by the tumor target. In patients with colorectal or medullary thyroid cancer, clinical studies performed with an anti-CEA/anti-DTPA-indium bifunctional antibody and an indium-111-labeled di-DTPA-TL bivalent hapten showed that tumor uptake was not modified compared to results for F(ab')2 fragments of the same anti-CEA antibody directly labeled with indium-111, whereas the radioactivity of normal tissues was significantly reduced (3- to 6-fold). The fast tumor uptake kinetics (several hours) and high or very high tumor-to-normal tissue ratios obtained with the bifunctional antibody technique are favorable parameters for efficient radioimmunotherapy.

  7. Antibody Blood Tests

    Science.gov (United States)

    Antibody Blood Tests Researchers have discovered that people with celiac disease who eat gluten have higher than normal levels of ... do I do if I have a negative blood test (or panel) but I’m still having symptoms? ...

  8. Decreased immune response to pneumococcal conjugate vaccine after 23-valent pneumococcal polysaccharide vaccine in children.

    Science.gov (United States)

    Sigurdardottir, Sigurveig Th; Center, Kimberly J; Davidsdottir, Katrin; Arason, Vilhjalmur A; Hjalmarsson, Bjorn; Elisdottir, Ragnheidur; Ingolfsdottir, Gunnhildur; Northington, Robert; Scott, Daniel A; Jonsdottir, Ingileif

    2014-01-09

    Pneumococcal polysaccharide vaccine (PPV) is used in children at high risk of IPD. PPV is generally not considered to induce immunologic memory, whereas pneumococcal conjugate vaccines (PCVs) elicit protective antibody responses in infants and induce immunologic memory. Little is known about the characteristics of immune responses to PCV in children who previously received PCV and PPV in series. To characterize immune responses to 13-valent pneumococcal CRM197 conjugate vaccine (PCV13; serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) in children vaccinated in infancy with 9-valent pneumococcal-meningococcal C-CRM197 conjugate combination vaccine (PCV9-MnCC), followed by a toddler dose of PCV9-MnCC or 23-valent pneumococcal polysaccharide vaccine (PPV23). Children (n=89) who received PCV9-MnCC in infancy and PPV23 or PCV9-MnCC at age 12 months in a previous (2002-2003) study were vaccinated at age 7.5 years with PCV13; groups PPV23/PCV13 (n=50) and PCV9/PCV13 (n=39). Immunoglobulin (Ig)G antibodies, avidity, and opsonophagocytic activity (OPA) were measured before and at 1 and 4 weeks postvaccination. One week postvaccination, IgG levels increased significantly for all serotypes in both groups, and >97% of vaccinees achieved IgG ≥0.35μg/ml 4 weeks after PCV13 vaccination. The PCV9/PCV13 group had higher IgG responses compared with the PPV23/PCV13 group. The upper limits of the 95% confidence intervals of the PPV23/PCV13:PCV9/PCV13 IgG geometric mean concentration ratios were vaccination of toddlers may compromise subsequent responses to pneumococcal conjugate vaccines. The clinical relevance of this finding is unclear. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Evaluation of components of X-ray irradiated 7-valent pneumococcal conjugate vaccine and pneumococcal vaccine polyvalent and X-ray and gamma-ray irradiated acellular pertussis component of DTaP vaccine products

    International Nuclear Information System (INIS)

    May, J.C.; Rey, L.; Lee, C.-J.; Arciniega, Juan

    2004-01-01

    Samples of pneumococcal vaccine polyvalent, 7-valent pneumococcal conjugate vaccine, and two different diphtheria and tetanus toxoids and acellular pertussis vaccines adsorbed were irradiated with X-rays and/or gamma-rays (Co-60). Mouse IgG and IgM antibody responses (ELISA) for types 9V, 14, 18C, and 19F pneumococcal polysaccharides and conjugates indicated that the polysaccharides were more tolerant of the radiation than the conjugates. The mouse antibody response for the detoxified pertussis toxin (PT) antigen, filamentous hemagglutinin antigen (FHA), pertactin (PRN), and fimbriae types 2 and 3 (FIM) antigens for the appropriate vaccine type indicated that the antibody response was not significantly changed in the 25 kGy X-ray irradiated vaccines frozen in liquid nitrogen compared to the control vaccine

  10. Evaluation of components of X-ray irradiated 7-valent pneumococcal conjugate vaccine and pneumococcal vaccine polyvalent and X-ray and gamma-ray irradiated acellular pertussis component of DTaP vaccine products

    Energy Technology Data Exchange (ETDEWEB)

    May, J.C. E-mail: may@cber.fda.gov; Rey, L. E-mail: louis.rey@bluewin.ch; Lee, C.-J.; Arciniega, Juan

    2004-10-01

    Samples of pneumococcal vaccine polyvalent, 7-valent pneumococcal conjugate vaccine, and two different diphtheria and tetanus toxoids and acellular pertussis vaccines adsorbed were irradiated with X-rays and/or gamma-rays (Co-60). Mouse IgG and IgM antibody responses (ELISA) for types 9V, 14, 18C, and 19F pneumococcal polysaccharides and conjugates indicated that the polysaccharides were more tolerant of the radiation than the conjugates. The mouse antibody response for the detoxified pertussis toxin (PT) antigen, filamentous hemagglutinin antigen (FHA), pertactin (PRN), and fimbriae types 2 and 3 (FIM) antigens for the appropriate vaccine type indicated that the antibody response was not significantly changed in the 25 kGy X-ray irradiated vaccines frozen in liquid nitrogen compared to the control vaccine.

  11. Herceptin conjugates linked by EDC boost direct tumor cell death via programmed tumor cell necrosis.

    Directory of Open Access Journals (Sweden)

    Jiemiao Hu

    Full Text Available Tumor-targeted antibody therapy is one of the safest biological therapeutics for cancer patients, but it is often ineffective at inducing direct tumor cell death and is ineffective against resistant tumor cells. Currently, the antitumor efficacy of antibody therapy is primarily achieved by inducing indirect tumor cell death, such as antibody-dependent cell cytotoxicity. Our study reveals that Herceptin conjugates, if generated via the crosslinker EDC (1-ethyl-3-(3-dimethylaminopropyl carbodiimide hydrochloride, are capable of engendering human epidermal growth factor receptor 2 (Her2 positive tumor cells death. Using a high-performance liquid chromatography (HPLC system, three peaks with estimated molecular weights of antibody monomer, dimer, and trimer were isolated. Both Herceptin trimer and dimer separated by HPLC induced significant levels of necrotic tumor cell death, although the trimer was more effective than the dimer. Notably, the Herceptin trimer also induced Herceptin-resistant tumor cell death. Surprisingly different from the known cell death mechanism that often results from antibody treatment, the Herceptin trimer elicited effective and direct tumor cell death via a novel mechanism: programmed cell necrosis. In Her2-positive cells, inhibition of necrosis pathways significantly reversed Herceptin trimer-induced cell death. In summary, the Herceptin trimer reported herein harbors great potential for overcoming tumor cell resistance to Herceptin treatment.

  12. Selective Effects of a Morphine Conjugate Vaccine on Heroin and Metabolite Distribution and Heroin-Induced Behaviors in Rats

    Science.gov (United States)

    Pravetoni, M.; Harris, A.C.; Birnbaum, A.K.; Pentel, P.R.

    2013-01-01

    Morphine conjugate vaccines have effectively reduced behavioral effects of heroin in rodents and primates. To better understand how these effects are mediated, heroin and metabolite distribution studies were performed in rats in the presence and absence of vaccination. In non-vaccinated rats 6-monoacetylmorphine (6-MAM) was the predominant opioid in plasma and brain as early as 1 minute after i.v. administration of heroin and for up to 14 minutes. Vaccination with morphine conjugated to keyhole limpet hemocyanin (M-KLH) elicited high titers and concentrations of antibodies with high affinity for heroin, 6-MAM, and morphine. Four minutes after heroin administration vaccinated rats showed substantial retention of all three opioids in plasma compared to controls and reduced 6-MAM and morphine, but not heroin, distribution to brain. Administration of 6-MAM rather than heroin in M-KLH vaccinated rats showed a similar drug distribution pattern. Vaccination reduced heroin-induced analgesia and blocked heroin-induced locomotor activity throughout 2 weeks of repeated testing. Higher serum opioid-specific antibody concentrations were associated with higher plasma opioid concentrations, lower brain 6-MAM and morphine concentrations, and lower heroin-induced locomotor activity. Serum antibody concentrations over 0.2 mg/ml were associated with substantial effects on these measures. These data support a critical role for 6-MAM in mediating the early effects of i.v. heroin and suggest that reducing 6-MAM concentration in brain is essential to the efficacy of morphine conjugate vaccines. PMID:23220743

  13. Targeted cancer therapy through antibody fragments-decorated nanomedicines.

    Science.gov (United States)

    Alibakhshi, Abbas; Abarghooi Kahaki, Fatemeh; Ahangarzadeh, Shahrzad; Yaghoobi, Hajar; Yarian, Fatemeh; Arezumand, Roghaye; Ranjbari, Javad; Mokhtarzadeh, Ahad; de la Guardia, Miguel

    2017-12-28

    Active targeting in cancer nanomedicine, for improved delivery of agents and diagnose, has been reviewed as a successful way for facilitating active uptake of theranostic agents by the tumor cells. The application of a targeting moiety in the targeted carrier complexes can play an important role in differentiating between tumor and healthy tissues. The pharmaceutical carriers, as main part of complexes, can be polymeric nanoparticles, micelles, liposomes, nanogels and carbon nanotubes. The antibodies are among the natural ligands with highest affinity and specificity to target pharmaceutical nanoparticle conjugates. However, the limitations, such as size and long circulating half-lives, hinder reproducible manufacture in clinical studies. Therefore, novel approaches have moved towards minimizing and engineering conventional antibodies as fragments like scFv, Fab, nanobody, bispecific antibody, bifunctional antibody, diabody and minibody preserving their functional potential. Different formats of antibody fragments have been reviewed in this literature update, in terms of structure and function, as smart ligands in cancer diagnosis and therapy of tumor cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Genetic fusion protein 3×STa-ovalbumin is an effective coating antigen in ELISA to titrate anti-STa antibodies.

    Science.gov (United States)

    Duan, Qiangde; Zhang, Weiping

    2017-07-01

    Heat-stable toxin type I (STa)-ovalbumin chemical conjugates are currently used as the only coating antigen in ELISA to titrate anti-STa antibodies for ETEC vaccine candidates. STa-ovalbumin chemical conjugation requires STa toxin purification, a process that can be carried out by only a couple of laboratories and often with a low yield. Alternative ELISA coating antigens are needed for anti-STa antibody titration for ETEC vaccine development. In the present study, we genetically fused STa toxin gene (three copies) to a modified chicken ovalbumin gene for genetic fusion 3×STa-ovalbumin, and examined application of this fusion protein as an alternative coating antigen of anti-STa antibody titration ELISA. Data showed fusion protein 3×STa-ovalbumin was effectively expressed and extracted, and anti-STa antibody titration ELISA using this recombinant protein (25 ng per well) or STa-ovalbumin chemical conjugates (10 ng/well) showed the same levels of sensitivity and specificity. Furthermore, mice immunized with this fusion protein developed anti-STa antibodies; induced antibodies showed in vitro neutralization activity against STa toxin. These results indicate that recombinant fusion protein 3×STa-ovalbumin is an effective ELISA coating antigen for anti-STa antibody titration, enabling a reliable reagent supply to make standardization of STa antibody titration assay feasible and to accelerate ETEC vaccine development. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  15. Exploring the Effect of Conjugation Site and Chemistry on the Immunogenicity of an anti-Group B Streptococcus Glycoconjugate Vaccine Based on GBS67 Pilus Protein and Type V Polysaccharide.

    Science.gov (United States)

    Nilo, Alberto; Passalacqua, Irene; Fabbrini, Monica; Allan, Martin; Usera, Aimee; Carboni, Filippo; Brogioni, Barbara; Pezzicoli, Alfredo; Cobb, Jennifer; Romano, Maria Rosaria; Margarit, Immaculada; Hu, Qi-Ying; Berti, Francesco; Adamo, Roberto

    2015-08-19

    We have recently described a method for tyrosine-ligation of complex glycans that was proven efficient for the site selective coupling of GBS capsular polysaccharides (PSs). Herein, we explored the effect of conjugation of type V polysaccharide onto predetermined lysine or tyrosine residues of the GBS67 pilus protein with the dual role of T-cell carrier for the PS and antigen. For the preparation of a conjugate at predetermined lysine residues of the protein, we investigated a two-step procedure based on microbial Transglutaminase (mTGase) catalyzed insertion of a tag bearing an azide for following copper-free strain-promoted azide-alkyne [3 + 2] cycloaddition (SPAAC) with the polysaccharide. Two glycoconjugates were obtained by tyrosine-ligation through the known SPAAC and a novel thiol-maleimide addition based approach. Controls were prepared by random conjugation of PSV to GBS67 and CRM197, a carrier protein present in many commercial vaccines. Immunological evaluation in mice showed that all the site-directed constructs were able to induce good levels of anti-polysaccharide and anti-protein antibodies inducing osponophagocytic killing of strains expressing individually PSV or GBS67. GBS67 randomly conjugated to PSV showed carrier properties similar to CRM197. Among the tested site-directed conjugates, tyrosine-directed ligation and thiol-malemide addition was elected as the best combination to ensure production of anti-polysaccharide and anti-protein functional antibodies (in vitro opsonophagocytic killing titers) comparable to the controls made by random conjugation, while avoiding anti-linker antibodies. Our findings demonstrate that (i) mTGase based conjugation at lysine residues is an alternative approach for the synthesis of large capsular polysaccharide-protein conjugates; (ii) GBS67 can be used with the dual role of antigen and carrier for PSV; and (iii) thiol-maleimide addition in combination with tyrosine-ligation ensures the production of anti

  16. Modulating antibody pharmacokinetics using hydrophilic polymers.

    Science.gov (United States)

    Chen, Chen; Constantinou, Antony; Deonarain, Mahendra

    2011-09-01

    The use of hydrophilic polymers as a substitute for the Fc-domain in immuno- or non-immuno-based binding proteins is accelerating. Chemical PEGylation has led the way and is still the most advanced and clinically-approved approach. Hydrophilic polymers act by maintaining a flexible conformation and hydrogen bonding to a network of water molecules to acquire a larger hydrodynamic volume and apparent mass than their actual molecular mass suggest. The benefits are increased blood half-life and bioavailability, stability and reduced immunogenicity. In the case of PEG, there is also evidence of enhanced targeting and reduced side effects, but drawbacks include the fact that PEG is non-biodegradable. This report reviews the state of the art for antibody PEGylation in terms of approaches and effects. Additionally, non-biological (such as N-(2-hydroxypropyl)methacrylamide) and potentially superior biological alternatives (such as polysialylation) are described, ending with recombinant approaches (such as hydrophilic peptides and glyco-engineering), which promise to circumvent the need for chemical modification altogether. The emergence of many small, antibody fragment-like mimics will drive the need for such technologies, and PEGylation is still the choice polymer due to its established use and track record. However, there will be a place for many alternative technologies if they can match the pharmacokinetics of PEG-conjugates and bring addition beneficial features such as easier production.

  17. 9th annual European Antibody Congress, November 11-13, 2013, Geneva, Switzerland.

    Science.gov (United States)

    Reichert, Janice M; Beck, Alain; Lugovskoy, Alexey A; Wurch, Thierry; Coats, Steven; Brezski, Randall J

    2014-01-01

    The annual European Antibody Congress (EAC) has traditionally been the key event for updates on critical scientific advances in the antibody field, and 2013 was no exception. Organized by Terrapinn, the well-attended meeting featured presentations on considerations for developing antibodies and antibody-like therapeutics, with separate tracks for antibody-drug conjugates, naked antibodies, and multispecific antibodies or protein scaffolds. The overall focus of the EAC was current approaches to enhance the functionality of therapeutic antibodies or other targeted proteins, with the ultimate goal being improvement of the safety and efficacy of the molecules as treatments for cancer, immune-mediated disorders and other diseases. Roundtable discussion sessions gave participants opportunities to engage in group discussions with industry leaders from companies such as Genmab, Glenmark Pharmaceuticals, MedImmune, Merrimack Pharmaceuticals, and Pierre Fabre. As the 2013 EAC was co-located with the World Biosimilar Congress, participants also received an update on European Medicines Agency guidelines and thoughts on the future direction and development of biosimilar antibodies in the European Union.

  18. DNA-mediated strand displacement facilitates sensitive electronic detection of antibodies in human serums.

    Science.gov (United States)

    Dou, Baoting; Yang, Jianmei; Shi, Kai; Yuan, Ruo; Xiang, Yun

    2016-09-15

    We describe here the development of a sensitive and convenient electronic sensor for the detection of antibodies in human serums. The sensor is constructed by self-assembly formation of a mixed monolayer containing the small molecule epitope conjugated double stranded DNA probes on gold electrode. The target antibody binds the epitope on the dsDNA probe and lowers the melting temperature of the duplex, which facilitates the displacement of the antibody-linked strand of the duplex probe by an invading methylene blue-tagged single stranded DNA (MB-ssDNA) through the strand displacement reaction and leads to the capture of many MB-ssDNA on the sensor surface. Subsequent electrochemical oxidation of the methylene blue labels results in amplified current response for sensitive monitoring of the antibodies. The antibody assay conditions are optimized and the sensor exhibits a linear range between 1.0 and 25.0nM with a detection limit of 0.67nM for the target antibody. The sensor is also selective and can be employed to detect the target antibodies in human serum samples. With the advantages of using small molecule epitope as the antibody recognition element over traditional antigen, the versatile manipulability of the DNA probes and the unique properties of the electrochemical transduction technique, the developed sensor thus hold great potential for simple and sensitive detection of different antibodies and other proteins in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Anti-dog IgG secondary antibody successfully detects IgG in a variety of aquatic mammals

    Science.gov (United States)

    Roehl, Katherine; Jankowski, Mark D.; Hofmeister, Erik K.

    2016-01-01

    Serological tests play an important role in the detection of wildlife diseases. However, while there are many commercial assays and reagents available for domestic species, there is a need to develop efficient serological assays for wildlife. In recent years, marine mammals have represented a wildlife group with emerging infectious diseases, such as influenza, brucellosis, and leptospirosis. However, with the exception of disease-agent-specific assays or functional assays, few reports describe the use of antibody detection assays in marine mammals. In an indirect enzyme-linked immunoassay (EIA) or an immunofluorescence assay, antibody is detected using an antitarget species secondary conjugated antibody. The sensitivity of the assay depends on the avidity of the binding reaction between the bound antibody and the detection antibody. A commercial polyclonal antidog IgG conjugated antibody was tested in an EIA for its ability to sensitively detect the IgG of seven marine mammals including sea otter (Enhydra lutris), polar bear (Ursus maritimus), grey seal (Halichoerus grypus), harbor seal (Phoca vitulina), northern elephant seal (Mirounga angustirostris), California sea lion (Zalophus californianus), Pacific walrus (Odobenus rosmarus) and one freshwater mammal: Asian small-clawed otter (Aonyx cinerea). With the exception of Asian small-clawed sea otters, the detection of IgG in these marine mammals either exceeded or was nearly equal to detection of dog IgG. The use of the tested commercial antidog IgG antibody may be a valid approach to the detection of antibody response to disease in sea mammals.

  20. Surface modification of polyacrylonitrile fiber for immobilization of antibodies and detection of analyte

    International Nuclear Information System (INIS)

    Jain, Swati; Chattopadhyay, Sruti; Jackeray, Richa; Singh, Harpal

    2009-01-01

    Pendent nitrile groups of multifilamentous polyacrylonitrile (PAN) fibers were reduced to amino groups using lithium aluminum hydride for different time of reduction and amine content was estimated by performing acid-base titrations. Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) were used for the characterization of the generated amino groups and thermal properties of the reduced fibers, respectively. The surface morphology of the fibers after reduction and immobilization was characterized using Scanning Electron Microscope (SEM). The newly formed amino groups of the fibers were activated by using glutaraldehyde for the covalent linking of Goat anti-Rabbit IgG-HRP (GAR-HRP) antibody enzyme conjugate. Modified PAN fibers were evaluated as a matrix for sandwich ELISA by using Goat anti-Rabbit antibody (GAR-IgG), Rabbit anti-Goat (RAG-IgG) as analyte and enzyme conjugate GAR-HRP. The fibers reduced for 24 h were able to detect the analyte RAG-IgG at a concentration as low as 3.75 ng mL -1 with 12% skimmed milk as blocking reagent for the optimized concentration of primary antibody GAR-IgG 3 μg mL -1 and peroxidase conjugate GAR-HRP dilution of 8000 fold. The sensitivity, specificity and reproducibility of the developed immunoassay was further established with antibodies present in human blood using Rabbit anti-Human (RAH-IgG) antibody and the corresponding HRP enzyme conjugate. As low as 0.1 μL of human blood was sufficient to perform the assay with the modified fibers.

  1. Surface modification of polyacrylonitrile fiber for immobilization of antibodies and detection of analyte.

    Science.gov (United States)

    Jain, Swati; Chattopadhyay, Sruti; Jackeray, Richa; Singh, Harpal

    2009-11-10

    Pendent nitrile groups of multifilamentous polyacrylonitrile (PAN) fibers were reduced to amino groups using lithium aluminum hydride for different time of reduction and amine content was estimated by performing acid-base titrations. Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) were used for the characterization of the generated amino groups and thermal properties of the reduced fibers, respectively. The surface morphology of the fibers after reduction and immobilization was characterized using Scanning Electron Microscope (SEM). The newly formed amino groups of the fibers were activated by using glutaraldehyde for the covalent linking of Goat anti-Rabbit IgG-HRP (GAR-HRP) antibody enzyme conjugate. Modified PAN fibers were evaluated as a matrix for sandwich ELISA by using Goat anti-Rabbit antibody (GAR-IgG), Rabbit anti-Goat (RAG-IgG) as analyte and enzyme conjugate GAR-HRP. The fibers reduced for 24h were able to detect the analyte RAG-IgG at a concentration as low as 3.75ng mL(-1) with 12% skimmed milk as blocking reagent for the optimized concentration of primary antibody GAR-IgG 3microg mL(-1) and peroxidase conjugate GAR-HRP dilution of 8000 fold. The sensitivity, specificity and reproducibility of the developed immunoassay was further established with antibodies present in human blood using Rabbit anti-Human (RAH-IgG) antibody and the corresponding HRP enzyme conjugate. As low as 0.1microL of human blood was sufficient to perform the assay with the modified fibers.

  2. Surface modification of polyacrylonitrile fiber for immobilization of antibodies and detection of analyte

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Swati, E-mail: swatijain.iitd@gmail.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India); Chattopadhyay, Sruti, E-mail: srutic@hotmail.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India); Jackeray, Richa, E-mail: richajackeray.iitd@gmail.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India); Singh, Harpal, E-mail: harpal2000@yahoo.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India)

    2009-11-10

    Pendent nitrile groups of multifilamentous polyacrylonitrile (PAN) fibers were reduced to amino groups using lithium aluminum hydride for different time of reduction and amine content was estimated by performing acid-base titrations. Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) were used for the characterization of the generated amino groups and thermal properties of the reduced fibers, respectively. The surface morphology of the fibers after reduction and immobilization was characterized using Scanning Electron Microscope (SEM). The newly formed amino groups of the fibers were activated by using glutaraldehyde for the covalent linking of Goat anti-Rabbit IgG-HRP (GAR-HRP) antibody enzyme conjugate. Modified PAN fibers were evaluated as a matrix for sandwich ELISA by using Goat anti-Rabbit antibody (GAR-IgG), Rabbit anti-Goat (RAG-IgG) as analyte and enzyme conjugate GAR-HRP. The fibers reduced for 24 h were able to detect the analyte RAG-IgG at a concentration as low as 3.75 ng mL{sup -1} with 12% skimmed milk as blocking reagent for the optimized concentration of primary antibody GAR-IgG 3 {mu}g mL{sup -1} and peroxidase conjugate GAR-HRP dilution of 8000 fold. The sensitivity, specificity and reproducibility of the developed immunoassay was further established with antibodies present in human blood using Rabbit anti-Human (RAH-IgG) antibody and the corresponding HRP enzyme conjugate. As low as 0.1 {mu}L of human blood was sufficient to perform the assay with the modified fibers.

  3. Natural and Man-made Antibody Repertories for Antibody Discovery

    Directory of Open Access Journals (Sweden)

    Juan C eAlmagro

    2012-11-01

    Full Text Available Antibodies are the fastest-growing segment of the biologics market. The success of antibody-based drugs resides in their exquisite specificity, high potency, stability, solubility, safety and relatively inexpensive manufacturing process in comparison with other biologics. We outline here the structural studies and fundamental principles that define how antibodies interact with diverse targets. We also describe the antibody repertoires and affinity maturation mechanisms of human, mice and chickens, plus the use of novel single-domain antibodies in camelids and sharks. These species all utilize diverse evolutionary solutions to generate specific and high affinity antibodies and illustrate the plasticity of natural antibody repertoires. In addition, we discuss the multiple variations of man-made antibody repertoires designed and validated in the last two decades, which have served as tools to explore how the size, diversity and composition of a repertoire impact the antibody discovery process.

  4. Antibody-linked drug destroys tumor cells and tumor blood vessels in many types of cancer | Center for Cancer Research

    Science.gov (United States)

    A team led by Brad St. Croix, Ph.D., Senior Associate Scientist, Mouse Cancer Genetics Program, has developed an antibody-drug conjugate (ADC) that destroys both tumor cells and the blood vessels that nourish them. The drug significantly shrank breast tumors, colon tumors and several other types of cancer and prolonged survival. Learn more...  

  5. GH and IGF-I induction by passive immunization of rainbow trout Oncorhynchus mykiss Walbaum using a somatostatin 14 antibody

    Science.gov (United States)

    Inhibition of the growth axis by somatostatin was studied in juvenile rainbow trout using passive immunization with a previously isolated somatostatin antibody (antiSS-14). Upon subcutaneously injection of laying hens (Gallus domesticus) with conjugated somatostatin-14 (SS-14), the antiSS-14 was iso...

  6. Cross-conjugation and quantum interference: a general correlation?

    DEFF Research Database (Denmark)

    Valkenier, Hennie; Guedon, Constant M.; Markussen, Troels

    2014-01-01

    -conjugation patterns, but identical lengths, i.e. an anthracene (linear conjugation), an anthraquinone (cross-conjugation), and a dihydroanthracene (broken conjugation) derivative. To benchmark reliable trends, conductance experiments on these series have been performed by various techniques. Here, we compare data...... characterized by beta = 0.37 +/- 0.03 angstrom(-1) (CP-AFM). Remarkably, for the second series, we do not only find that the linearly conjugated anthracene-containing wire is the most conductive, but also that the cross-conjugated anthraquinone-containing wire is less conductive than the broken...

  7. Lot-to-lot stability of antibody reagents for flow cytometry.

    Science.gov (United States)

    Böttcher, Sebastian; van der Velden, Vincent H J; Villamor, Neus; Ritgen, Matthias; Flores-Montero, Juan; Murua Escobar, Hugo; Kalina, Tomas; Brüggemann, Monika; Grigore, Georgiana; Martin-Ayuso, Marta; Lecrevisse, Quentin; Pedreira, Carlos E; van Dongen, Jacques J M; Orfao, Alberto

    2017-03-30

    The fluorescence detected using fluorochrome-labelled monoclonal antibodies depends not only on the abundance of the target antigen, but amongst many other factors also on the effective fluorochrome-to-antibody ratio. The diagnostic approach of the EuroFlow consortium relies on reproducible fluorescence intensities over time. A capture bead system for mouse immunoglobulin light chains was utilized to compare the mean fluorescence intensity of 1323 consecutive antibody lots to the currently used lot of the same monoclonal antibody. In total, 157 different monoclonal antibodies were assessed over seven years. Median relative difference between consecutive lots was 3.8% (range: 0.01% to 164.7%, interquartile range: 1.3% to 10.1%). The relative difference exceeded 20% in 8.8% of all comparisons. FITC labelled monoclonal antibodies (median relative difference: 2.1%) showed a significantly smaller variation between lots than antibodies conjugated to PE (3.5%), PECy7 (3.9%), PerCPCy5.5 (5.8%), APC (5.8%), APCH7 (7.4%), and APCC750 (14.5%). Reagents labelled with Pacific Blue (1.4%), Pacific Orange (2.4%), HV450 (0.7%), and HV500 (1.7%) demonstrated more consistent results compared to conjugates of BV421 (4.1%) and BV510 (16.2%). Additionally, significant differences in lot-to-lot fluorescence stability amongst antibodies labelled with the same fluorochrome were observed between manufacturers. These observations might guide future quality recommendations for the production and application of fluorescence-labelled monoclonal antibodies in multicolor flow cytometry. Copyright © 2017. Published by Elsevier B.V.

  8. Large Scale Generation and Characterization of Anti-Human CD34 Monoclonal Antibody in Ascetic Fluid of Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Koushan Sineh sepehr

    2013-02-01

    Full Text Available Purpose: Monoclonal antibodies or specific antibodies are now an essential tool of biomedical research and are of great commercial and medical value. The purpose of this study was to produce large scale of monoclonal antibody against CD34 in order to diagnostic application in leukemia and purification of human hematopoietic stem/progenitor cells. Methods: For large scale production of monoclonal antibody, hybridoma cells that produce monoclonal antibody against human CD34 were injected into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. 5 ml ascitic fluid was harvested from each mouse in two times. Evaluation of mAb titration was assessed by ELISA method. The ascitic fluid was examined for class and subclasses by ELISA mouse mAb isotyping Kit. mAb was purified from ascitic fluid by affinity chromatography on Protein A-Sepharose. Purity of monoclonal antibody was monitored by SDS -PAGE and the purified monoclonal antibody was conjugated with FITC. Results: Monoclonal antibodies with high specificity and sensitivity against human CD34 by hybridoma technology were prepared. The subclass of antibody was IgG1 and its light chain was kappa. Conclusion: The conjugated monoclonal antibody could be a useful tool for isolation, purification and characterization of human hematopoietic stem cells.

  9. Phase conjugate Michelson interferometer for optical logic

    Science.gov (United States)

    Khoury, Jed

    2017-05-01

    The interference theory is developed for of the phase conjugate Michelson interferometer in which its ordinary mirrors are replaced by a single externally pumped phase conjugate mirror. According to the theory, it was found that for an interferometer with two equal arms, the path length difference depends solely on the initial alignment of the two input beams, and the vertical alignment readout. Small vertical misalignments in the readout beam by mrad causes a huge change in the phase difference in the phase between the two interferometer arms beam. The phase difference is proportional to the interferometer arm lengths. The overlap between the phase conjugate beams is not affected by the interferometer beam alignment. The interferometer is proposed for nondestructive testing and the design all optical logic and associated fuzzy logic for ultrafast optical pattern recognition.

  10. Tight-binding treatment of conjugated polymers

    DEFF Research Database (Denmark)

    Lynge, Thomas Bastholm

    This PhD thesis concerns conjugated polymers which constitute a constantly growing research area. Today, among other things, conjugated polymers play a role in plastic based solar cells, photodetectors and light emitting diodes, and even today such plastic-based components constitute an alternative...... of tomorrow. This thesis specifically treats the three conjugated polymers trans-polyacetylene (tPA), poly(para-phenylene) (PPP) and poly(para-phe\\-nylene vinylene) (PPV). The present results, which are derived within the tight-binding model, are divided into two parts. In one part, analytic results...... are derived for the optical properties of the polymers expressed in terms of the optical susceptibility both in the presence and in the absence of a static electric field. In the other part, the cumputationally efficient Density Functional-based Tight-Binding (DFTB) model is applied to the description...

  11. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Directory of Open Access Journals (Sweden)

    Jacqueline M. Miller

    2011-01-01

    Full Text Available Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles.

  12. Nonlinear conjugate gradient methods in micromagnetics

    Directory of Open Access Journals (Sweden)

    J. Fischbacher

    2017-04-01

    Full Text Available Conjugate gradient methods for energy minimization in micromagnetics are compared. The comparison of analytic results with numerical simulation shows that standard conjugate gradient method may fail to produce correct results. A method that restricts the step length in the line search is introduced, in order to avoid this problem. When the step length in the line search is controlled, conjugate gradient techniques are a fast and reliable way to compute the hysteresis properties of permanent magnets. The method is applied to investigate demagnetizing effects in NdFe12 based permanent magnets. The reduction of the coercive field by demagnetizing effects is μ0ΔH = 1.4 T at 450 K.

  13. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Science.gov (United States)

    Miller, Jacqueline M.; Mesaros, Narcisa; Van Der Wielen, Marie; Baine, Yaela

    2011-01-01

    Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT) designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles. PMID:21991444

  14. Serogroup A meningococcal conjugate vaccines in Africa.

    Science.gov (United States)

    Kristiansen, Paul A; Jørgensen, Hannah J; Caugant, Dominique A

    2015-01-01

    Serogroup A meningococcal epidemics have been a recurrent public health problem, especially in resource-poor countries of Africa. Recently, the administration in mass vaccination campaigns of a single dose of the monovalent meningococcal conjugate vaccine, MenAfriVac, to the 1-29 year-old population of sub-Saharan Africa has prevented epidemics of meningitis caused by serogroup A Neisseria meningitidis. This strategy has also been shown to provide herd protection of the non-vaccinated population. Development of meningococcal conjugate vaccines covering other serogroups and enhanced use of the pneumococcal and Haemophilus influenzae type b conjugate vaccines must be pursued to fully control bacterial meningitis in sub-Saharan Africa.

  15. Conjugate gradient algorithms using multiple recursions

    Energy Technology Data Exchange (ETDEWEB)

    Barth, T.; Manteuffel, T.

    1996-12-31

    Much is already known about when a conjugate gradient method can be implemented with short recursions for the direction vectors. The work done in 1984 by Faber and Manteuffel gave necessary and sufficient conditions on the iteration matrix A, in order for a conjugate gradient method to be implemented with a single recursion of a certain form. However, this form does not take into account all possible recursions. This became evident when Jagels and Reichel used an algorithm of Gragg for unitary matrices to demonstrate that the class of matrices for which a practical conjugate gradient algorithm exists can be extended to include unitary and shifted unitary matrices. The implementation uses short double recursions for the direction vectors. This motivates the study of multiple recursion algorithms.

  16. CO-releasing molecule (CORM) conjugate systems.

    Science.gov (United States)

    Kautz, Anna Christin; Kunz, Peter C; Janiak, Christoph

    2016-11-15

    The development of CORMs (CO-releasing molecules) as a prodrug for CO administration in living organisms has attracted significant attention. CORMs offer the promising possibility of a safe and controllable release of CO in low amounts triggered by light, ligands, enzymes, etc. For the targeting of specific tissues or diseases and to prevent possible side effects from metals and other residues after CO release, these CORMs are attached to biocompatible systems, like peptides, polymers, nanoparticles, dendrimers, protein cages, non-wovens, tablets, and metal-organic frameworks. We discuss in this review the known CORM carrier conjugates, in short CORM conjugates, with covalently-bound or incorporated CORMs for medicinal and therapeutic applications. Most conjugates are nontoxic, show increasing half-lives of CO release, and make use of the EPR-effect, but still show problems because of a continuous background of CO release and the absence of an on/off-switch for the CO release.

  17. Antibody informatics for drug discovery

    DEFF Research Database (Denmark)

    Shirai, Hiroki; Prades, Catherine; Vita, Randi

    2014-01-01

    to the antibody science in every project in antibody drug discovery. Recent experimental technologies allow for the rapid generation of large-scale data on antibody sequences, affinity, potency, structures, and biological functions; this should accelerate drug discovery research. Therefore, a robust bioinformatic...... infrastructure for these large data sets has become necessary. In this article, we first identify and discuss the typical obstacles faced during the antibody drug discovery process. We then summarize the current status of three sub-fields of antibody informatics as follows: (i) recent progress in technologies...... for antibody rational design using computational approaches to affinity and stability improvement, as well as ab-initio and homology-based antibody modeling; (ii) resources for antibody sequences, structures, and immune epitopes and open drug discovery resources for development of antibody drugs; and (iii...

  18. Conjugated Polymers as Actuators: Modes of Actuation

    DEFF Research Database (Denmark)

    Skaarup, Steen

    2004-01-01

    The physical and chemical properties of conjugated polymers often depend very strongly on the degree of doping with anions or cations. The movement of ions in and out of the polymer matrix as it is redox cycled is also accompanied by mechanical changes. Both the volume and the stiffness can exhibit...... significant differences between the oxidized and reduced states. These effects form the basis of the use of conjugated polymers as actuators (or “artificial muscles”) controllable by a small (1-10 V) voltage. Three basic modes of actuation (bending, linear extension and stiffness change) have been proposed...

  19. Functionalized conjugated polyelectrolytes design and biomedical applications

    CERN Document Server

    Wang, Shu

    2014-01-01

    Functionalized Conjugated Polyelectrolytes presents a comprehensive review of these polyelectrolytes and their biomedical applications. Basic aspects like molecular design and optoelectronic properties are covered in the first chapter. Emphasis is placed on the various applications including sensing (chemical and biological), disease diagnosis, cell imaging, drug/gene delivery and disease treatment. This book explores a multi-disciplinary topic of interest to researchers working in the fields of chemistry, materials, biology and medicine. It also offers an integrated perspective on both basic research and application issues. Functionalized conjugated polyelectrolyte materials, which have already drawn considerable interest, will become a major new direction for biomedicine development.

  20. Conjugated polymers as actuators: modes of actuation

    DEFF Research Database (Denmark)

    Skaarup, Steen

    2007-01-01

    The physical and chemical properties of conjugated polymers often depend very strongly on the degree of doping with anions or cations. The movement of ions in and out of the polymer matrix as it is redox cycled is also accompanied by mechanical changes. Both the volume and the stiffness can exhibit...... significant differences between the oxidized and reduced states. These effects form the basis of the use of conjugated polymers as actuators (or “artificial muscles”) controllable by a small (1-10 V) voltage. Three basic modes of actuation (bending, linear extension and stiffness change) have been proposed...

  1. De-conjugation behavior of conjugated estrogens in the raw sewage, activated sludge and river water.

    Science.gov (United States)

    Kumar, Vimal; Johnson, Andrew C; Nakada, Norihide; Yamashita, Naoyuki; Tanaka, Hiroaki

    2012-08-15

    The fate and behavior of estrone-3-sulfate (E1-3S), estradiol-3-sulfate (E2-3S), estrone-3-glucuronide (E1-3G) and estradiol-3-glucuronide (E2-3G) were studied in raw sewage, activated sludge and river water using microcosms. The glucuronide conjugates had a half-life of 0.4h in raw sewage, yielding 40-60% of their free estrogens. Field observations at three activated sludge processes suggested complete transformation of the glucuronide conjugates in the sewer. In river water glucuronide conjugates half-lives extended to over 2d yielding 60-100% of their free parent estrogens. Transformation of the sulfate conjugates in raw sewage and river water was slow with little formation of the parent estrogens. Sulfate conjugates could readily be detected in sewage influent in the field studies. In activated sludge the sulfate conjugates had half-lives of 0.2h with the transient formation of 10-55% of the free parent estrogens. Field studies indicated transformation of sulfate conjugates across the sewage treatment, although a proportion escaped into the effluent. These results broadly support the view that glucuronide conjugates will be entirely transformed within the sewer largely to their parent estrogens. The sulfate conjugates may persist in raw sewage and river water but are transformable in activated sludge and, in the case of E2-3S, reform a high proportion of the parent estrogen. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Antithyroglobulin Antibodies and Antimicrosomal Antibodies in Various Thyroid Diseases

    International Nuclear Information System (INIS)

    Lee, Gwon Jun; Hong, Key Sak; Choi, Kang Won; Lee, Kyu; Koh, Chang Soon; Lee, Mun Ho; Park, Sung Hoe; Chi, Je Geun; Lee, Sang Kook

    1979-01-01

    The authors investigated the incidence of antithyroglobulin antibodies and antibodies and antimicrosomal antibodies measured by tanned red cell hemagglutination method in subjects suffering from various thyroid disorders. 1) In 15 normal patients, neither suffering from any thyroid diseases nor from any other autoimmune disorders, the antithyroglobulin antibodies were all negative, but the antimicrosomal antibody was positive only in one patient (6.7%). 2) The antithyroglobulin antibodies were positive in 31.5% (34 patients) of 108 patients with various thyroid diseases, and the antimicrosomal antibodies were positive in 37.0% (40 patients). 3) of the 25 patients with Graves' diseases, 7 patients (28.0%) showed positive for the antithyroglobulin antibodies, and 9 (36.0%) for the antimicrosomal antibodies. There was no definite differences in clinical and thyroid functions between the groups with positive and negative results. 4) Both antibodies were positive in 16 (88.9%) and 17 (94.4%) patients respectively among 18 patients with Hashimoto's thyroiditis, all of them were diagnosed histologically. 5) Three out of 33 patients with thyroid adenoma showed positive antibodies, and 3 of 16 patients with thyroid carcinoma revealed positive antibodies. 6) TRCH antibodies demonstrated negative results in 2 patients with subacute thyroiditis, but positive in one patient with idiopathic primary myxedema. 7) The number of patients with high titers(>l:802) was 16 for antithyroglobulin antibody, and 62.5% (10 patients) of which was Hashimoto's thyroiditis. Thirteen (65.0) of 20 patients with high titers (>l:802) for antimicrosomal antibody was Hashimoto's thyroiditis. TRCH test is a simple, sensitive method, and has high reliability and reproducibility. The incidences and titers of antithyroglobulin antibody and antimicrosomal antibody are especially high in Hashimoto's thyroiditis.

  3. Synthesis and immunological properties of Vi and di-O-acetyl pectin protein conjugates with adipic acid dihydrazide as the linker.

    Science.gov (United States)

    Kossaczka, Z; Bystricky, S; Bryla, D A; Shiloach, J; Robbins, J B; Szu, S C

    1997-06-01

    The Vi capsular polysaccharide of Salmonella typhi, a licensed vaccine for typhoid fever in individuals > or = 5 years old, induces low and short-lived antibodies in children, and reinjection does not elicit booster responses at any age. Its immunogenicity was improved by binding Vi to proteins by using N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) as a linker. Similar findings were observed with the structurally related, di-O-acetyl derivative of pectin [poly-alpha(1-->4)-D-GalpA] designated OAcP. Protein conjugates of Vi and OAcP were synthesized by carbodiimide-mediated synthesis with adipic acid dihydrazide (ADH) as the linker. Hydrazide groups were introduced into proteins (bovine serum albumin or recombinant Pseudomonas aeruginosa exoprotein A) by treatment with ADH and 1-ethyl-3(3-dimethylaminopropyl carbodiimide (EDC). The resultant adipic acid hydrazide derivatives (AH-proteins), containing 2.3 to 3.4% AH, had antigenic and physicochemical properties similar to those of the native proteins. The AH-proteins were bound to Vi and OAcP by treatment with EDC. The immunogenicity of Vi or OAcP, alone or as protein conjugates, was evaluated in young outbred mice and guinea pigs by subcutaneous injection of 2.5 and 5.0 microg, respectively, of polysaccharide, and antibodies were measured by enzyme-linked immunosorbent assay. All conjugates were significantly more immunogenic than Vi or OAcP alone and induced booster responses with 5- to 25-fold increases of antibodies. Vi conjugates were significantly more immunogenic than their OAcP analogs. A carboxymethyl derivative of yeast beta-glucan enhanced the anti-Vi response elicited by an OAcP conjugate but had no effect on the immunogenicity of Vi or of OAcP alone. Vi and OAcP conjugates synthesized by this scheme will be evaluated clinically.

  4. Production, purification and characterization of antibodies to 1,25-dihydroxyvitamin D raised in chicken egg yolk.

    Science.gov (United States)

    Bauwens, R M; Kint, J A; Devos, M P; Van Brussel, K A; De Leenheer, A P

    1987-11-30

    For this sensitive RIA for 1 alpha,25-dihydroxyvitamin D, we used antibodies to 1 alpha,25-dihydroxycholecalciferol-3-hemisuccinate conjugated to bovine serum albumin, raised in eggs by immunization of chickens. We describe an efficient method for purification of IgG from egg yolk. We characterized these antibodies with immunoelectrophoresis and by radioimmunoassay. These antibodies show a high affinity for 1 alpha,25-dihydroxyvitamin D3 but cross react with other vitamin D metabolites as well. Extraction and liquid chromatography are necessary to isolate the 1 alpha,25-dihydroxyvitamin D from human serum or plasma before determination by RIA. The sensitivity of the assay is estimated at 5 pg/tube.

  5. Conjugation fidelity of double phase-conjugate mirrors in photorefractive materials with two-center transport.

    Science.gov (United States)

    Geri, I; Ozkul, C

    1996-11-01

    The temporal evolution of double phase-conjugate mirrors (DPCM's) in photorefractive materials such as BaTiO(3):Co:Fe is studied by use of the plane-wave expansion method. The buildup time of DPCM and its conjugation fidelity are compared with those of photorefractive materials with a single-center transport. Numerical simulations show that one can decrease the threshold value of the coupling strength required for the DPCM operation with a high conjugation fidelity by doping the BaTiO(3) crystals weakly with Co in comparison with undoped crystals.

  6. Compositions, antibodies, asthma diagnosis methods, and methods for preparing antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hongjun; Zangar, Richard C.

    2017-01-17

    Methods for preparing an antibody are provided with the method including incorporating 3-bromo-4-hydroxy-benzoic acid into a protein to form an antigen, immunizing a mammalian host with the antigen, and recovering an antibody having an affinity for the antigen from the host. Antibodies having a binding affinity for a monohalotyrosine are provided as well as composition comprising an antibody bound with monohalotyrosine. Compositions comprising a protein having a 3-bromo-4-hydroxy-benzoic acid moiety are also provided. Methods for evaluating the severity of asthma are provide with the methods including analyzing sputum of a patient using an antibody having a binding affinity for monohalotyrosine, and measuring the amount of antibody bound to protein. Methods for determining eosinophil activity in bodily fluid are also provided with the methods including exposing bodily fluid to an antibody having a binding affinity for monohalotyrosine, and measuring the amount of bound antibody to determine the eosinophil activity.

  7. Efficient Xerographic Photoreceptors from Conjugated Polymers and Polymer Blends

    National Research Council Canada - National Science Library

    Zhang, Xuejun, Ph.D

    1998-01-01

    Bilayer xerographic photoreceptors in which pi-conjugated polymers and binary conjugated polymer blends are used as the charge generation layer have been fabricated, evaluated, and shown to be highly efficient...

  8. Immune responses to HBsAg conjugated to protein D of non-typeable Haemophilus influenzae in mice.

    Directory of Open Access Journals (Sweden)

    Qiudong Su

    Full Text Available Hepatitis B vaccine that contains an aluminum hydroxide adjuvant induces apoptotic death of Hepa 1-6 cells. Difficult-to-degrade chemical additives in vaccines effectively enhance vaccine immunogenicity, but also affect the host tissue. Identification of bio-molecules that are readily degraded and compatible in vivo as an adjuvant is important for vaccine research. The hapten-carrier effect suggests that stimulation of helper T (Th cells by carrier adjuvants is feasible. Protein D (PD of non-typeable Haemophilus influenzae covalently conjugated to some polysaccharide vaccines has been confirmed to convert T-cell independent (TI antigens into T-cell dependent (TD antigens, and elicit strong T-cell responses ultimately. Herein, we would substitube PD for aluminum hydroxide adjuvant in Hepatitis B vaccine.Truncated PD (amino acids 20-364 was expressed in Escherichia coli and purified by (NH42SO4 precipitation and DEAE chromatography. After evaluation of antigenicity by western blotting, PD was covalently conjugated to yeast-derived recombinant HBsAg by cross-linking with glutaraldehyde. Intramuscular immunization with the conjugate induced higher level of HBsAg-specific antibody than did HBsAg alone (p < 0.05, and was comparable to commercial Hepatitis B vaccine. During the surveillance period (days 35-105, anti-HBs titers were hold high. Moreover, the conjugated vaccine enhanced Th1 immune responses, while Th2 responses were also activated and induced an antibody response, as determined by IFN-γ ELISPOT and IgG1/IgG2a ratio assays.Recombinant truncated PD covalently conjugated to HBsAg antigen enhanced the immunogenicity of the antigen in mice simultaneously by humoral and cellular immune response, which would facilitate therapeutic hepatitis B vaccines.

  9. Vaccine and Monoclonal Antibody That Enhance Mouse Resistance to Candidiasis ▿

    Science.gov (United States)

    Xin, Hong; Cutler, Jim E.

    2011-01-01

    Previously we showed that antibodies specific for the glycan β-1,2-mannotriose [β-(Man)3] on the cell surface of Candida albicans protect mice against disseminated candidiasis (H. Xin, S. Dziadek, D. R. Bundle, and J. E. Cutler, Proc. Natl. Acad. Sci. U. S. A. 105:13526–13531, 2008). Furthermore, six 14-mer peptides that are within the N-terminal portion of C. albicans wall proteins were conjugated to the glycan in an attempt to create immunogenic glycopeptide conjugates. By a dendritic cell (DC)-based immunization approach, all were immunogenic and three of the six conjugates induced a high degree of protection in mice. Interestingly, whereas all six peptides induced antibody responses when used alone to pulse DCs for subsequent immunizations, three peptides induced protection, and one in particular, peptide Fba (derived from fructose-bisphosphate aldolase), induced robust protective responses and is the focus of the current work. Fba peptide is not restricted by the major histocompatibility complex class II (MHC-II), as it induced anti-Fba antibodies in mice of different H-2 haplotypes and in rabbits. Furthermore, the peptide induced protection against disease caused by different C. albicans strains. Partial protection was achieved when alum was used in place of DCs for Fba immunizations. The passive transfer of immune sera from Fba-vaccinated mice, but not immune serum preabsorbed with fungal cells, conferred protection in naïve mice. This result, along with our finding that a monoclonal antibody specific for the peptide, E2-9 (IgM), protected mice against candidiasis, provide strong evidence that antibodies contribute to protection. Our work demonstrates the utility of cell wall peptides alone or as glycopeptides in vaccines designed for the induction of immunity against candidiasis and monoclonal antibodies as a rapid immunoprotective approach against the disease. PMID:21832099

  10. Flow cytometric measurement of RNA synthesis using bromouridine labelling and bromodeoxyuridine antibodies

    DEFF Research Database (Denmark)

    Jensen, P O; Larsen, J; Christiansen, J

    1993-01-01

    Nuclear RNA synthesis can be analysed by flow cytometry of cells labelled with 5-bromouridine (BrUrd) and stained with anti-bromodeoxyuridine (BrdUrd) antibody and FITC-conjugated secondary antibody. A panel of 5 different commercially available anti-BrdUrd antibodies was tested on cells of a HL-60...... human leukemia cell line, stained as a methanol-fixed nuclear suspension. The BrUrd-induced fluorescence signals were highest with the antibody ABDM (Partec), moderate but reproducible with B-44 (Becton Dickinson), variable or low with BR-3 and IU-4 (Caltag), and not detectable with Bu20a (DAKO...... the variation of RNA synthesis during the cell cycle. The BrUrd incorporation was high in the S and G2 phase, variable in G1, and negligible in mitosis. Similar results were obtained using other cell types....

  11. Functional analysis of the conjugation system from Clostridium perfringens

    OpenAIRE

    Wisniewski, Jessica Ann

    2017-01-01

    In Clostridium perfringens, toxins that cause histotoxic and gastrointestinal diseases have been identified on a family of large conjugative plasmids. The tcp transfer locus was initially identified on the prototype conjugative plasmid, pCW3. This locus has been shown to mediate conjugative plasmid transfer and studies on several of the Tcp proteins have identified their role in plasmid transfer. In general less is known about the mechanism of conjugative transfer in Gram positive bacteria, n...

  12. Production and characterization of polyclonal antibody against a synthetic peptide from β-actin protein

    Directory of Open Access Journals (Sweden)

    Nazila Amini

    2014-06-01

    Full Text Available Objective(s:Antibodies against actin, as one of the most widely studied structural and multifunctional housekeeping proteins in eukaryotic cells, are used as internal loading controls in western blot analyses. The aim of this study was to produce polyclonal antibody against a synthetic peptide derived from N-terminal region of β-actin protein to be used as a protein loading control in western blot and other assay systems. Materials and Methods: A synthetic peptide derived from β-actin protein was designed and conjugated to Keyhole limpet hemocyanin (KLH (and used to immunize a white New Zealand rabbit. The antibody was purified from serum by affinity chromatography column. The purity of the antibody was determined by SDS-PAGE and its ability to recognize the immunizing peptide was measured by ELISA. The reactivity of the antibody with β-actin protein in a panel of different cell lysates was then evaluated by western blot. In addition, the reactivity of the antibody with the corresponding protein was also evaluated by Immunocytochemistry and Immunohistochemistry in different samples. Results: The antibody could recognize the immunizing peptide in ELISA. It could also recognize            β-actin protein in western blot as well as in immunocytochemistry and immunohistochemistry. Conclusion: Our data suggest that this antibody may be used as an internal control in western blot analyses as well as in other immunological applications such as ELISA,immunocytochemistry and immunohistochemistry.

  13. Production and characterization of polyclonal antibody against a synthetic peptide from β-actin protein.

    Science.gov (United States)

    Amini, Nazila; Vishteh, Mohadeseh Naghi; Zarei, Omid; Hadavi, Reza; Ahmadvand, Negah; Rabbani, Hodjattallah; Jeddi-Tehrani, Mahmood

    2014-06-01

    Antibodies against actin, as one of the most widely studied structural and multifunctional housekeeping proteins in eukaryotic cells, are used as internal loading controls in western blot analyses. The aim of this study was to produce polyclonal antibody against a synthetic peptide derived from N-terminal region of β-actin protein to be used as a protein loading control in western blot and other assay systems. A synthetic peptide derived from β-actin protein was designed and conjugated to Keyhole limpet hemocyanin (KLH) and used to immunize a white New Zealand rabbit. The antibody was purified from serum by affinity chromatography column. The purity of the antibody was determined by SDS-PAGE and its ability to recognize the immunizing peptide was measured by ELISA. The reactivity of the antibody with β-actin protein in a panel of different cell lysates was then evaluated by western blot. In addition, the reactivity of the antibody with the corresponding protein was also evaluated by Immunocytochemistry and Immunohistochemistry in different samples. The antibody could recognize the immunizing peptide in ELISA. It could also recognize β-actin protein in western blot as well as in immunocytochemistry and immunohistochemistry. Our data suggest that this antibody may be used as an internal control in western blot analyses as well as in other immunological applications such as ELISA, immunocytochemistry and immunohistochemistry.

  14. Towards a peptide-based suspension array for the detection of pestivirus antibodies in swine.

    Science.gov (United States)

    van der Wal, Fimme J; Jelsma, Tinka; Fijten, Helmi; Achterberg, René P; Loeffen, Willie L A

    2016-09-01

    Classical swine fever (CSF) is a highly contagious and lethal disease in swine. Serological tests for the diagnosis of CSF need not only to detect antibodies against CSFV, but also need to differentiate these from antibodies against other pestiviruses. To investigate the possibilities of specific peptide-based serology, various synthetic peptides that represent a well-described linear epitope of the CSFV E2 protein (TAVSPTTLR) were used to test the viability of a peptide-based suspension array for the detection of antibodies against pestiviruses in swine. The results show that N-terminally biotinylated peptides can bind to avidin conjugated beads, and function in detection of the corresponding monoclonal antibody WH303. There are indications that the length of the spacer between epitope and biotin affect the efficiency of the peptide-antibody interaction. A protocol was established that enables probing for antibodies in porcine sera, where neutravidin-blocking of serum and the use of empty control beads for normalization was crucial. With a set of porcine sera with antibodies against various pestiviruses, the proof of concept of a peptide-based suspension array for specific detection of antibodies against pestiviruses in porcine sera was demonstrated. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Antithyroid microsomal antibody

    Science.gov (United States)

    ... that you have a higher chance of developing thyroid disease in the future. Antithyroid microsomal antibodies may be ... PA: Elsevier; 2016:chap 11. Weiss RE, Refetoff S. Thyroid function testing. In: Jameson JL, De Groot LJ, eds. Endocrinology: Adult and ... Lupus Read more ...

  16. Antibodies Targeting EMT

    Science.gov (United States)

    2017-10-01

    determine their targets on the cell. The newly discovered antibodies will then be engineered for utility as new highly specific drugs and diagnostics in...are from the aldo-keto reductase family (AKRs). Remarkably, 3 of the top 10 genes with induction in the mesenchymal TES2b cells Figure 1. Amino

  17. Monoclonal antibodies in haematopathology

    Energy Technology Data Exchange (ETDEWEB)

    Grignani, F.; Martelli, M.F.; Mason, D.Y.

    1985-01-01

    This book contains over 40 selections. Some of the titles are: Oncogene (c-myc, c-myb) amplification in acute myelogenous leukaemia; Ultrastructural characterization of leukaemic cells with monoloclonal antibodies; Origin of B-cell malignancies; Immunohistology of gut lymphomas; and Spurious evidence of lineage infidelity in monocytic leukaemia.

  18. Monoclonal antibodies in myeloma

    DEFF Research Database (Denmark)

    Sondergeld, P.; van de Donk, N. W. C. J.; Richardson, P. G.

    2015-01-01

    The development of monoclonal antibodies (mAbs) for the treatment of disease goes back to the vision of Paul Ehrlich in the late 19th century; however, the first successful treatment with a mAb was not until 1982, in a lymphoma patient. In multiple myeloma, mAbs are a very recent and exciting add...

  19. Conjugation of hydroxyapatite nanocrystals with human immunoglobulin G for nanomedical applications.

    Science.gov (United States)

    Iafisco, Michele; Varoni, Elena; Di Foggia, Michele; Pietronave, Stefano; Fini, Milena; Roveri, Norberto; Rimondini, Lia; Prat, Maria

    2012-02-01

    Inorganic nanosized drug carriers are a promising field in nanomedicine applied to cancer. Their conjugation with antibodies combines the properties of the nanoparticles themselves with the specific and selective recognition ability of the antibodies to antigens. Biomimetic carbonate-hydroxyapatite (HA) nanoparticles were synthesized and fully characterized; human IgGs, used as model antibodies, were coupled to these nanocrystals. The maximum loading amount, the interaction modelling, the preferential orientation and the secondary structure modifications were evaluated using theoretical models (Langmuir, Freundlich and Langmuir-Freundlich) spectroscopic (UV-Vis, Raman), calorimetric (TGA), and immunochemical techniques (ELISA, Western Blot). HA nanoparticles of about 30 nm adsorbed human IgGs, in a dose-dependent, saturable and stable manner with micromolar affinity and adsorption capability around 2.3 mg/m(2). Adsorption isotherm could be described by Langmuir-Freundlich model, and was due to both energetically homogeneous and heterogeneous binding sites on HA surface, mainly of electrostatic nature. Binding did not induce secondary structure modification of IgGs. A preferential IgG end-on orientation with the involvement of IgG Fc moiety in the adsorption seems most probable due to the steric hindrance of their Fab domains. Biomimetic HA nanocrystals are suitable substrates to produce nanoparticles which can be functionalized with antibodies for efficient targeted drug delivery to tumours. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Women experiencing the intergenerationality of conjugal violence

    Directory of Open Access Journals (Sweden)

    Gilvânia Patrícia do Nascimento Paixão

    2015-10-01

    Full Text Available Objective: to analyze the family relationship, in childhood and adolescence, of women who experience conjugal violence.Method: qualitative study. Interviews were held with 19 women, who were experiencing conjugal violence, and who were resident in a community in Salvador, Bahia, Brazil. The project was approved by the Research Ethics Committee (N. 42/2011.Results: the data was organized using the Discourse of the Collective Subject, identifying the summary central ideas: they witnessed violence between their parents; they suffered repercussions from the violence between their parents: they were angry about the mother's submission to her partner; and they reproduced the conjugal violence. The discourse showed that the women witnessed, in childhood and adolescence, violence between their parents, and were injured both physically and psychologically. As a result of the mother's submission, feelings of anger arose in the children. However, in the adult phase of their own lives, they noticed that their conjugal life resembled that of their parents, reproducing the violence.Conclusion: investment is necessary in strategies designed to break inter-generational violence, and the health professionals are important in this process, as it is a phenomenon with repercussions in health. Because they work in the Family Health Strategy, which focuses on the prevention of harm and illness, health promotion and interdepartmentality, the nurses are essential in the process of preventing and confronting this phenomenon.

  1. Women experiencing the intergenerationality of conjugal violence.

    Science.gov (United States)

    Paixão, Gilvânia Patrícia do Nascimento; Gomes, Nadirlene Pereira; Diniz, Normélia Maria Freire; Carvalho e Lira, Margaret Ollinda de Souza; Carvalho, Milca Ramaiane da Silva; da Silva, Rudval Souza

    2015-01-01

    to analyze the family relationship, in childhood and adolescence, of women who experience conjugal violence. qualitative study. Interviews were held with 19 women, who were experiencing conjugal violence, and who were resident in a community in Salvador, Bahia, Brazil. The project was approved by the Research Ethics Committee (N. 42/2011). the data was organized using the Discourse of the Collective Subject, identifying the summary central ideas: they witnessed violence between their parents; they suffered repercussions from the violence between their parents: they were angry about the mother's submission to her partner; and they reproduced the conjugal violence. The discourse showed that the women witnessed, in childhood and adolescence, violence between their parents, and were injured both physically and psychologically. As a result of the mother's submission, feelings of anger arose in the children. However, in the adult phase of their own lives, they noticed that their conjugal life resembled that of their parents, reproducing the violence. investment is necessary in strategies designed to break inter-generational violence, and the health professionals are important in this process, as it is a phenomenon with repercussions in health. Because they work in the Family Health Strategy, which focuses on the prevention of harm and illness, health promotion and interdepartmentality, the nurses are essential in the process of preventing and confronting this phenomenon.

  2. Unsymmetrical extended -conjugated zinc phthalocyanine for ...

    Indian Academy of Sciences (India)

    We have designed and synthesized a new unsymmetrical zinc phthalocyanine based on `push-pull' and extended -conjugation concept, PCH008. The new sensitizer was fully characterized by CHN anlysis, UV-Vis., fluorescence spectroscopies and cyclic voltammetry. The new sensitizer which upon anchoring onto ...

  3. Compositions for directed alignment of conjugated polymers

    Science.gov (United States)

    Kim, Jinsang; Kim, Bong-Gi; Jeong, Eun Jeong

    2016-04-19

    Conjugated polymers (CPs) achieve directed alignment along an applied flow field and a dichroic ratio of as high as 16.67 in emission from well-aligned thin films and fully realized anisotropic optoelectronic properties of CPs in field-effect transistor (FET).

  4. Theoretical study of conjugated porphyrin polymers

    DEFF Research Database (Denmark)

    Pedersen, T.G.; Lynge, T.B.; Kristensen, P.K.

    2005-01-01

    for these applications. From a theoretical analysis of excitons in long metalloporphyrin chains, we demonstrate that the binding energy is much lower than in usual conjugated polymers. Our calculated absorption spectra are in good agreement with measurements. (c) 2004 Elsevier B.V. All rights reserved....

  5. preconditioning the modified conjugate gradient method

    African Journals Online (AJOL)

    Admin

    The conventional conjugate method (CGM) was originally developed by Hestenes and. Stiefel (1952) as a method of solution for linear systems. Fletcher and Reeves (1964) built the necessary underlying theory for a successful application of the method to quadratic functional and developed its convergence properties.

  6. Ciprofloxacin conjugated zinc oxide nanoparticle: A camouflage ...

    Indian Academy of Sciences (India)

    excellent antibacterial activity against clinically isolated multidrug resistant bacterial strains of Escherichia coli,. Staphylococcus aureus and ... Keywords. Zinc oxide nanoparticles; ciprofloxacin; chemical conjugation; antibacterial property. 1. Introduction ... Nanoparticles of TiO2, ZnO, silver, etc. are commonly known for their ...

  7. Bacillus thuringiensis Conjugation in Simulated Microgravity

    Science.gov (United States)

    Beuls, Elise; van Houdt, Rob; Leys, Natalie; Dijkstra, Camelia; Larkin, Oliver; Mahillon, Jacques

    2009-10-01

    Spaceflight experiments have suggested a possible effect of microgravity on the plasmid transfer among strains of the Gram-positive Bacillus thuringiensis, as opposed to no effect recorded for Gram-negative conjugation. To investigate these potential effects in a more affordable experimental setup, three ground-based microgravity simulators were tested: the Rotating Wall Vessel (RWV), the Random Positioning Machine (RPM), and a superconducting magnet. The bacterial conjugative system consisted in biparental matings between two B. thuringiensis strains, where the transfer frequencies of the conjugative plasmid pAW63 and its ability to mobilize the nonconjugative plasmid pUB110 were assessed. Specifically, potential plasmid transfers in a 0-g position (simulated microgravity) were compared to those obtained under 1-g (normal gravity) condition in each device. Statistical analyses revealed no significant difference in the conjugative and mobilizable transfer frequencies between the three different simulated microgravitational conditions and our standard laboratory condition. These important ground-based observations emphasize the fact that, though no stimulation of plasmid transfer was observed, no inhibition was observed either. In the case of Gram-positive bacteria, this ability to exchange plasmids in weightlessness, as occurs under Earth's conditions, should be seen as particularly relevant in the scope of spread of antibiotic resistances and bacterial virulence.

  8. Conjugated Polymer Actuators: Prospects and Limitations

    DEFF Research Database (Denmark)

    Skaarup, Steen

    2007-01-01

    Actuators constructed with a conjugated polymer as the active part have been predicted to have a number of highly desirable properties: Large mechanical strength, high power density, i.e. high actuation speeds possible, sufficient maximum strain values, high reversibility and safe, low voltages (1...

  9. Theory of periodic conjugate heat transfer

    CERN Document Server

    Zudin, Yuri B

    2016-01-01

    This book presents the theory of periodic conjugate heat transfer in detail. It offers a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body.

  10. One-pot synthesis of conjugated trienes

    Czech Academy of Sciences Publication Activity Database

    Šebesta, Petr; Jahn, Ullrich

    2009-01-01

    Roč. 103, č. 11 (2009), s. 990-990 ISSN 0009-2770. [Pokroky v organické, bioorganické a farmaceutické chemii /44./. 27.11.2009-29.11.2009, Liblice] Institutional research plan: CEZ:AV0Z40550506 Keywords : pheromones * Suzuki coupling * conjugated trienes Subject RIV: CC - Organic Chemistry

  11. Determinants of pneumococcal conjugate vaccine uptake among ...

    African Journals Online (AJOL)

    Subjects: The respondents were the parents/guardians of children less than two years of age attending immunisation services at KNH and those admitted in the peadiatric wards with pneumonia. Results: The study established that the determinants of uptake of Pneumococcal Conjugate Vaccine are age(OR 5.8, CI 1.4-23.4, ...

  12. Mass-Production and Characterization of Anti-CD20 Monoclonal Antibody in Peritoneum of Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Leili Aghebati

    2013-02-01

    Full Text Available Purpose: Monoclonal antibodies are important tools are used in basic research as well as, in diagnosis, imaging and treatment of immunodeficiency diseases, infections and cancers. The purpose of this study was to produce large scale of monoclonal antibody against CD20 in order to diagnostic application in leukemia and lymphomas disorders. Methods: Hybridoma cells that produce monoclonal antibody against human CD20 were administered into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. After twelve days, approximately 7 ml ascetic fluid was harvested from the peritoneum of each mouse. Evaluation of mAb titration was assessed by ELISA method. In the present study, we describe a protocol for large scale production of MAbs. Results: We prepared monoclonal antibodies (mAbs with high specificity and sensitivity against human CD20 by hybridoma method and characterized them by ELISA. The subclass of antibody was IgG2a and its light chain was kappa. Ascetic fluid was purified by Protein-A Sepharose affinity chromatography and the purified monoclonal antibody was conjugated with FITC and Immunofluorescence was done for confirming the specific binding. Conclusion: The conjugated monoclonal antibody could have application in diagnosis B-cell lymphomas, hairy cell leukemia, B-cell chronic lymphocytic leukemia, and melanoma cancer stem cells.

  13. Small is beautiful: N-trimethyl chitosan-ovalbumin conjugates for microneedle-based transcutaneous immunisation.

    Science.gov (United States)

    Bal, Suzanne M; Slütter, Bram; Jiskoot, Wim; Bouwstra, Joke A

    2011-05-23

    To provoke an immune response, a transcutaneously administered vaccine has to diffuse into the skin, reach the lymph nodes and be taken up by dendritic cells (DCs). To study these three steps we immunised mice transcutaneously (with microneedles), intradermally and intranodally. The effect of the formulation was investigated by formulating ovalbumin (OVA) in three ways with N-trimethyl chitosan (TMC): TMC+OVA mixtures, TMC-OVA conjugates and TMC/OVA nanoparticles. Both the percentage OVA(+) DCs in the lymph node and the resultant immunogenicity (serum IgG titres) were studied. Transcutaneously, the TMC-OVA conjugates induced the highest IgG levels and resulted in more OVA(+) DCs in the lymph nodes after 24h than the other TMC formulations. Intradermally, all TMC-adjuvanted OVA formulations increased IgG titres compared to plain OVA. These formulations formed a depot in the skin, prolonging OVA delivery to the lymph nodes. The prolonged delivery of TMC-adjuvanted OVA to lymph node resident DCs was also observed after intranodal immunisation, but in this case the higher uptake did not correspond with elevated antibody titres compared to plain OVA. In conclusion, after transcutaneous administration, TMC-OVA conjugates are most immunogenic among the tested formulations, likely because they penetrate the skin more easily than nanoparticles and consequently are better delivered to DCs, while they show higher uptake by DCs than TMC+OVA mixtures. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Stabilizing cations in the backbones of conjugated polymers

    NARCIS (Netherlands)

    Voortman, Thomas P.; de Gier, Hilde D.; Havenith, Remco W. A.; Chiechi, Ryan C.

    2014-01-01

    We synthesized a cross-conjugated polymer containing ketones in the backbone and converted it to a linearly conjugated, cationic polyarylmethine via a process we call "spinless doping" to create a new class of materials, conjugated polyions. This process involves activating the ketones with a Lewis

  15. DA conjugated polymers containing substituted thiophene, 1, 3, 4 ...

    Indian Academy of Sciences (India)

    ... electron-accepting (A) 1,3,4- oxadiazole unit and non-conjugation linkers. The conjugated segment in P1-P3 contains only five aromatic rings resulting in short conjugation length, but has an alternate D-A arrangement which significantly enhances the intramolecular charge transfer (ICT) interaction within the segment.

  16. Development of Immunoassay Based on Monoclonal Antibody Reacted with the Neonicotinoid Insecticides Clothianidin and Dinotefuran

    OpenAIRE

    Uchigashima, Mikiko; Watanabe, Eiki; Ito, Shigekazu; Iwasa, Seiji; Miyake, Shiro

    2012-01-01

    Enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody (MoAb) was developed for the neonicotinoid insecticide clothianidin. A new clothianidin hapten (3-[5-(3-methyl-2-nitroguanidinomethyl)-1,3-thiazol-2-ylthio] propionic acid) was synthesized and conjugated to keyhole limpet hemocyanin, and was used for monoclonal antibody preparation. The resulting MoAb CTN-16A3-13 was characterized by a direct competitive ELISA (dc-ELISA). The 50% of inhibition concentration value with cl...

  17. Humanized Antibodies for Antiviral Therapy

    Science.gov (United States)

    Co, Man Sung; Deschamps, Marguerite; Whitley, Richard J.; Queen, Cary

    1991-04-01

    Antibody therapy holds great promise for the treatment of cancer, autoimmune disorders, and viral infections. Murine monoclonal antibodies are relatively easy to produce but are severely restricted for therapeutic use by their immunogenicity in humans. Production of human monoclonal antibodies has been problematic. Humanized antibodies can be generated by introducing the six hypervariable regions from the heavy and light chains of a murine antibody into a human framework sequence and combining it with human constant regions. We humanized, with the aid of computer modeling, two murine monoclonal antibodies against herpes simplex virus gB and gD glycoproteins. The binding, virus neutralization, and cell protection results all indicate that both humanized antibodies have retained the binding activities and the biological properties of the murine monoclonal antibodies.

  18. Flow-pattern Guided Fabrication of High-density Barcode Antibody Microarray.

    Science.gov (United States)

    Ramirez, Lisa S; Wang, Jun

    2016-01-06

    Antibody microarray as a well-developed technology is currently challenged by a few other established or emerging high-throughput technologies. In this report, we renovate the antibody microarray technology by using a novel approach for manufacturing and by introducing new features. The fabrication of our high-density antibody microarray is accomplished through perpendicularly oriented flow-patterning of single stranded DNAs and subsequent conversion mediated by DNA-antibody conjugates. This protocol outlines the critical steps in flow-patterning DNA, producing and purifying DNA-antibody conjugates, and assessing the quality of the fabricated microarray. The uniformity and sensitivity are comparable with conventional microarrays, while our microarray fabrication does not require the assistance of an array printer and can be performed in most research laboratories. The other major advantage is that the size of our microarray units is 10 times smaller than that of printed arrays, offering the unique capability of analyzing functional proteins from single cells when interfacing with generic microchip designs. This barcode technology can be widely employed in biomarker detection, cell signaling studies, tissue engineering, and a variety of clinical applications.

  19. Rheumatoid factor interference in immunogenicity assays for human monoclonal antibody therapeutics.

    Science.gov (United States)

    Tatarewicz, Suzanna; Miller, Jill M; Swanson, Steven J; Moxness, Michael S

    2010-05-31

    Rheumatoid factors (RFs) are endogenous human antibodies that bind to human gamma globulins. RFs demonstrate preferential binding to aggregated gamma globulins and are involved in the clearing mechanism of immune complexes. Immunoassays designed to measure human anti-human antibodies (HAHA) after administration of monoclonal antibody therapeutics are thus vulnerable to interference from RFs. When using a sensitive electrochemiluminescent (ECL) bridging immunoassay, samples from subjects with rheumatoid arthritis demonstrated much higher baseline reactivity than healthy subjects. Interference was found to be dependent on the aggregation state of the therapeutic antibody that had been conjugated with the detection reagent (ruthenium). Size exclusion high performance liquid chromatography (SE-HPLC) demonstrated that of the total integrated peaks, as little as 0.55% high molecular weight aggregates (>600kDa) were sufficient to cause increased reactivity. Stability studies of the ruthenium and biotin conjugated therapeutic antibody indicated that storage time, temperature and buffer formulation were critical in maintaining the integrity of the reagents. Through careful SE-HPLC monitoring we were able to choose appropriate storage and buffer conditions which led to a reduction in the false reactivity rate in therapeutic-naïve serum from a rheumatoid arthritis population.

  20. Preparation and evaluation of Salmonella Enteritidis antigen conjugated with nanogold for screening of poultry flocks

    Directory of Open Access Journals (Sweden)

    Hazem Mohammed Ibrahim

    2017-08-01

    Full Text Available Aim: The present work aimed to develop lateral flow immunochromatographic strip (ICS test for detection of Salmonella Enteritidis (SE specific antibodies in chicken sera. Materials and Methods: A rapid lateral flow immunochromatographic test (LFIT has been developed, in which SE Group D antigen labeled with the gold chloride molecules laid on the conjugate pad. Staphylococcus aureus protein A was used as capture antibody at the test line (T of a nitrocellulose (NC membrane and anti-SE antigen-specific rabbit antibodies were used as capture antibody at the control line (C of the NC strip in the lateral flow layout device. Results: Using the developed LFIT, the minimal amount of SE-specific antibodies that can be detected in chicken serum sample was 1427 enzyme-linked immunosorbent assay (ELISA unit/100 μl that was equal to 0.1 μg (Ab/100 μl sample. 100 suspected serum samples collected from a poultry flock were tested with the prepared SE-LFIT kits and the locally prepared stained Salmonella antigen, and the results were compared with those obtained from examination of these samples with Salmonella Group D antibody ELISA kit as the gold standard test. The sensitivity, specificity, and accuracy of the prepared SE-LFIT antigen kits were 94.4%, 90%, and 94%, respectively, while those obtained with stained Salmonella antigen were 88.8%, 90%, and 89%, respectively. Conclusion: The developed test is a simple field rapid test of high sensitivity, specificity, and accuracy that can improve and facilitates rapid field surveillance of salmonellosis among chickens.

  1. iBodies: Modular Synthetic Antibody Mimetics Based on Hydrophilic Polymers Decorated with Functional Moieties

    Czech Academy of Sciences Publication Activity Database

    Šácha, Pavel; Knedlík, Tomáš; Schimer, Jiří; Tykvart, Jan; Parolek, Jan; Navrátil, Václav; Dvořáková, Petra; Sedlák, František; Ulbrich, Karel; Strohalm, Jiří; Majer, Pavel; Šubr, Vladimír; Konvalinka, Jan

    2016-01-01

    Roč. 55, č. 7 (2016), s. 2356-2360 ISSN 1433-7851 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LO1302 Institutional support: RVO:61388963 ; RVO:61389013 Keywords : antibody mimetics * HPMA * molecular recognition * polymer conjugates * protein targeting Subject RIV: CE - Biochemistry; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 11.994, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/anie.201508642/full

  2. Design of indirect solid-phase immunosorbent methods for detecting arenavirus antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A.

    1984-05-01

    Specifications have been elaborated for formulating indirect solid-phase enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (SPRIA) methods that employ anti-human and anti-mice G class immunoglobulin (IgG), conjugated with horseradish peroxidase and /sup 125/I for detecting the arenaviruses Junin, Machupo, Tacaribe, Amalpari, Tamiami, Lassa, and LCM (lymphocytic choriomeningitis). These methods make it possible to identify with a high degree of sensitivity arenavirus antigens and antibodies in various kinds of material.

  3. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    N.D. Zegers (Netty)

    1995-01-01

    textabstractSynthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps

  4. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    Zegers, N.D.

    1995-01-01

    Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the

  5. A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words.

    Science.gov (United States)

    Mirick, G R; Bradt, B M; Denardo, S J; Denardo, G L

    2004-12-01

    The United States Food and Drug Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ((90)yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ((131)I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) anti-CD20 MAbs for use in radioimmunotherapy (RIT) of non-Hodgkin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, assays were developed to determine HAGA (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to ''humanize'' MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades.

  6. A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words

    International Nuclear Information System (INIS)

    Mirick, G. R.; Bradt, B. M.; Denardo, S. J.; Denardo, G. L.

    2004-01-01

    The United States Food and Drugs Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ( 9 0yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ( 1 31I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) antiCD20 MAns for use in radioimmunotherapy (RIT) of non-Hodgikin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, essays were developed to determine HAGE (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to humanize MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades

  7. A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words

    Energy Technology Data Exchange (ETDEWEB)

    Mirick, G. R.; Bradt, B. M.; Denardo, S. J.; Denardo, G. L. [Calfornia Univ., Sacramento (United States). Davis Medical Center

    2004-12-01

    The United States Food and Drugs Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ({sup 9}0yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ({sup 1}31I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) antiCD20 MAns for use in radioimmunotherapy (RIT) of non-Hodgikin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, essays were developed to determine HAGE (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to humanize MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades.

  8. Development of a Pfs25-EPA malaria transmission blocking vaccine as a chemically conjugated nanoparticle.

    Science.gov (United States)

    Shimp, Richard L; Rowe, Christopher; Reiter, Karine; Chen, Beth; Nguyen, Vu; Aebig, Joan; Rausch, Kelly M; Kumar, Krishan; Wu, Yimin; Jin, Albert J; Jones, David S; Narum, David L

    2013-06-19

    Successful efforts to control infectious diseases have often required the use of effective vaccines. The current global strategy for control of malaria, including elimination and eradication will also benefit from the development of an effective vaccine that interrupts malaria transmission. To this end, a vaccine that disrupts malaria transmission within the mosquito host has been investigated for several decades targeting a 25 kDa ookinete specific surface protein, identified as Pfs25. Phase 1 human trial results using a recombinant Pfs25H/Montanide ISA51 formulation demonstrated that human Pfs25 specific antibodies block parasite infectivity to mosquitoes; however, the extent of blocking was likely insufficient for an effective transmission blocking vaccine. To overcome the poor immunogenicity, processes to produce and characterize recombinant Pfs25H conjugated to a detoxified form of Pseudomonas aeruginosa exoprotein A (EPA) have been developed and used to manufacture a cGMP pilot lot for use in human clinical trials. The Pfs25-EPA conjugate appears as a nanoparticle with an average molar mass in solution of approximately 600 kDa by static light scattering with an average diameter 20 nm (range 10-40 nm) by dynamic light scattering. The molar ratio of Pfs25H to EPA is about 3 to 1 by amino acid analysis, respectively. Outbred mice immunized with the Pfs25-EPA conjugated nanoparticle formulated on Alhydrogel(®) had a 75-110 fold increase in Pfs25H specific antibodies when compared to an unconjugated Pfs25H/Alhydrogel(®) formulation. A phase 1 human trial using the Pfs25-EPA/Alhydrogel(®) formulation is ongoing in the United States. Published by Elsevier Ltd.

  9. Do pneumococcal conjugate vaccines provide any cross-protection against serotype 19A?

    Directory of Open Access Journals (Sweden)

    Hoet Bernard

    2010-02-01

    Full Text Available Abstract Background Introduction of the 7-valent pneumococcal conjugate vaccine (7vCRM in several countries has led to a rapid, significant drop in vaccine-type invasive pneumococcal disease (IPD in immunized children. In the United States and some other countries with high antibiotic use, a subsequent rise in serotype 19A IPD has been taken to indicate that the 19F conjugate in the vaccine provides no cross-protection against the immunologically related 19A. Discussion We systematically assessed the clinical efficacy and effectiveness of 19F-containing vaccines against 19A disease or nasopharyngeal carriage by searching English-language articles in the electronic databases PubMed, Current contents, Scopus, and Embase from 1985 to 2008. The vaccine efficacy and effectiveness point estimates were consistently positive for modest protection against 19A IPD and acute otitis media (AOM. However, statistical significance was not reached in any individual study. No consistent impact of 7vCRM on 19A nasopharyngeal colonization could be detected. These findings are discussed in context of immunogenicity analyses indicating that 7vCRM induces functionally active anti-19A antibodies after the booster dose, and that other 19F-containing vaccine formulations may elicit higher levels of such antibodies after both primary and booster doses. Summary Taken together, these results suggest that 19F-conjugates can provide some protection against 19A disease. The magnitude of this protection in a given setting will likely depend on several factors. These include the anti-19A immunogenicity of the specific vaccine formulation, the number of doses of that formulation needed to elicit the response, and the burden of 19A disease that occurs after those doses. It is possible that a modest protective effect may be obscured by the presence of countervailing selection pressures (such as high antibiotic use that favor an increase in colonization with antibiotic

  10. Magnetic Purification of Antibodies

    Science.gov (United States)

    Dhadge, Vijaykumar Laxman

    This work aimed at the development of magnetic nanoparticles for antibody purification and at the evaluation of their performance in Magnetic fishing and in a newly developed hybrid technology Magnetic Aqueous Two Phase Systems. Magnetic materials were produced by coprecipitation and solvothermal approaches. Natural polymers such as dextran, extracellular polysaccharide and gum Arabic were employed for coating of iron oxide magnetic supports. Polymer coated magnetic supports were then modified with synthetic antibody specific ligands,namely boronic acid, a triazine ligand (named 22/8) and an Ugi ligand (named A2C7I1). To optimize the efficacy of magnetic nanoparticles for antibody magnetic fishing, various solutions of pure and crude antibody solutions along with BSA as a non-specific binding protein were tested. The selectivity of magnetic nanoparticle for antibody, IgG, was found effective with boronic acid and ligand 22/8. Magnetic supports were then studied for their performance in high gradient magnetic separator for effective separation capability as well as higher volume handling capability. The magnetic materials were also supplemented to aqueous two phase systems, devising a new purification technology. For this purpose, magnetic particles modified with boronic acid were more effective. This alternative strategy reduced the time of operation,maximized separation capability (yield and purity), while reducing the amount of salt required. Boronic acid coated magnetic particles bound 170 +/- 10 mg hIgG/g MP and eluted 160 +/- 5 mg hIgG/g MP, while binding only 15 +/- 5 mg BSA/g MP. The affinity constant for the interaction between hIgG and APBA_MP was estimated as 4.9 x 105 M-1 (Ka) with a theoretical maximum capacity of 492 mg hIgG adsorbed/g MP (Qmax). APBA_MPs were also tested for antibody purification directly from CHO cell supernatants. The particles were able to bind 98% of IgG loaded and to recover 95% of pure IgG (purity greater than 98%) at extremely

  11. High-efficiency astatination of antibodies using N-iodosuccinimide as the oxidising agent in labelling of N-succinimidyl 3-(trimethylstannyl)benzoate

    International Nuclear Information System (INIS)

    Lindegren, S.; Andersson, H.; Baeck, T.; Jacobsson, L.; Karlsson, B.; Skarnemark, G.

    2001-01-01

    Monoclonal antibodies C215, reactive with colorectal carcinomas, and MOv18, reactive with most of the ovarian carcinomas, were radiohalogenated with [ 211 At]astatine. The radiohalogen was conjugate coupled to antibodies via the intermediate labelling reagent N-succinimidyl-3-(trimethylstannyl)benzoate (m-MeATE) in a two-step, single-pot reaction. Optimisation of the labelling of the reagent was achieved using N-iodosuccinimide, NIS, as the oxidising agent. The yields ranged from 69-95% in the labelling of 0.1-1.0 nmole of the m-MeATE precursor. Subsequent conjugation to antibodies resulted in yields of 58±7%. In vitro binding to tumour cells showed that the immunoreactivity of both antibodies was retained after astatine labelling

  12. Nanobodies and Nanobody-Based Human Heavy Chain Antibodies As Antitumor Therapeutics

    Directory of Open Access Journals (Sweden)

    Peter Bannas

    2017-11-01

    Full Text Available Monoclonal antibodies have revolutionized cancer therapy. However, delivery to tumor cells in vivo is hampered by the large size (150 kDa of conventional antibodies. The minimal target recognition module of a conventional antibody is composed of two non-covalently associated variable domains (VH and VL. The proper orientation of these domains is mediated by their hydrophobic interface and is stabilized by their linkage to disulfide-linked constant domains (CH1 and CL. VH and VL domains can be fused via a genetic linker into a single-chain variable fragment (scFv. scFv modules in turn can be fused to one another, e.g., to generate a bispecific T-cell engager, or they can be fused in various orientations to antibody hinge and Fc domains to generate bi- and multispecific antibodies. However, the inherent hydrophobic interaction of VH and VL domains limits the stability and solubility of engineered antibodies, often causing aggregation and/or mispairing of V-domains. Nanobodies (15 kDa and nanobody-based human heavy chain antibodies (75 kDa can overcome these limitations. Camelids naturally produce antibodies composed only of heavy chains in which the target recognition module is composed of a single variable domain (VHH or Nb. Advantageous features of nanobodies include their small size, high solubility, high stability, and excellent tissue penetration in vivo. Nanobodies can readily be linked genetically to Fc-domains, other nanobodies, peptide tags, or toxins and can be conjugated chemically at a specific site to drugs, radionuclides, photosensitizers, and nanoparticles. These properties make them particularly suited for specific and efficient targeting of tumors in vivo. Chimeric nanobody-heavy chain antibodies combine advantageous features of nanobodies and human Fc domains in about half the size of a conventional antibody. In this review, we discuss recent developments and perspectives for applications of nanobodies and nanobody

  13. Nanobodies and Nanobody-Based Human Heavy Chain Antibodies As Antitumor Therapeutics.

    Science.gov (United States)

    Bannas, Peter; Hambach, Julia; Koch-Nolte, Friedrich

    2017-01-01

    Monoclonal antibodies have revolutionized cancer therapy. However, delivery to tumor cells in vivo is hampered by the large size (150 kDa) of conventional antibodies. The minimal target recognition module of a conventional antibody is composed of two non-covalently associated variable domains (VH and VL). The proper orientation of these domains is mediated by their hydrophobic interface and is stabilized by their linkage to disulfide-linked constant domains (CH1 and CL). VH and VL domains can be fused via a genetic linker into a single-chain variable fragment (scFv). scFv modules in turn can be fused to one another, e.g., to generate a bispecific T-cell engager, or they can be fused in various orientations to antibody hinge and Fc domains to generate bi- and multispecific antibodies. However, the inherent hydrophobic interaction of VH and VL domains limits the stability and solubility of engineered antibodies, often causing aggregation and/or mispairing of V-domains. Nanobodies (15 kDa) and nanobody-based human heavy chain antibodies (75 kDa) can overcome these limitations. Camelids naturally produce antibodies composed only of heavy chains in which the target recognition module is composed of a single variable domain (VHH or Nb). Advantageous features of nanobodies include their small size, high solubility, high stability, and excellent tissue penetration in vivo . Nanobodies can readily be linked genetically to Fc-domains, other nanobodies, peptide tags, or toxins and can be conjugated chemically at a specific site to drugs, radionuclides, photosensitizers, and nanoparticles. These properties make them particularly suited for specific and efficient targeting of tumors in vivo . Chimeric nanobody-heavy chain antibodies combine advantageous features of nanobodies and human Fc domains in about half the size of a conventional antibody. In this review, we discuss recent developments and perspectives for applications of nanobodies and nanobody-based human heavy

  14. Conjugated Polymers and Oligomers: Structural and Soft Matter Aspects

    DEFF Research Database (Denmark)

    This book identifies modern topics and current trends of structural and soft matter aspects of conjugated polymers and oligomers. Each chapter recognizes an active research line where structural perspective dominates research and therefore the book covers fundamental aspects of persistent...... conjugated polymer backbone, water soluble conjugated polyelectrolytes and surfactants, conjugated molecules and biomolecules and DNA and the advanced use of synchrotron radiation and electron microscopy to find out structural details in conjugated molecule films and devices as well as under ambient...... and extreme conditions....

  15. Clinical use of antibodies

    International Nuclear Information System (INIS)

    Baum, R.P.; Hoer, Gustav; Cox, P.H.; Buraggi, G.L.

    1991-01-01

    Use of monoclonal antibodies as tumour specific carrier molecules for therapeutic agents or as in vivo diagnostic reagents when labelled with radionuclides or NMR signal enhancers is attracting more and more attention. The potential is enormous but the technical problems are also considerable requiring the concerted action of many different scientific disciplines. This volume is based upon a symposium organised in Frankfurt in 1990 under the auspices of the European Association of Nuclear Medicines' Specialist Task Groups on Cardiology and the Utility of Labelled Antibodies. It gives a multidisciplinary review of the state of the art and of problems to be solved as well as recording the not inconsiderable successes which have been booked to date. The book will be of value as a reference to both clinicians and research scientists. refs.; figs.; tabs

  16. Determining the limit of detection of surface bound antibody.

    Science.gov (United States)

    Madiona, Robert M T; Welch, Nicholas G; Scoble, Judith A; Muir, Benjamin W; Pigram, Paul J

    2017-08-11

    Determination of a limit of detection (LoD) for surface bound antibodies is crucial for the development and deployment of sensitive bioassays. The measurement of very low concentrations of surface bound antibodies is also important in the manufacturing of pharmaceutical products such as antibody-conjugated pharmaceuticals. Low concentrations are required to avoid an immune response from the target host. Enzyme-linked immunosorbent assay (ELISA), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to determine the LoD for the surface bound antibody (antiepidermal growth factor receptor antibody) on silicon substrates. Antibody solution concentrations between 10 μg/ml and 1 ng/ml and a control (antibody-free buffer solution) were employed, and the detection performance of each technique was compared. For this system, the ELISA LoD was 100 ng/ml and the XPS LoD was 1 μg/ml, corresponding to an estimated surface concentration of 49  ± 7 ng/cm 2 using a 1 μg/ml solution. Due to the multivariate complexity of ToF-SIMS data, analysis was carried out using three different methods, peak ratio calculations, principal component analysis, and artificial neural network analysis. The use of multivariate analysis with this dataset offers an unbiased analytical approach based on the peaks selected from ToF-SIMS data. The results estimate a ToF-SIMS LoD between applied antibody concentrations of 10 and 100 ng/mL. For surface bound antibodies on a silicon substrate, the LoD is below an estimated surface concentration of 49 ng/cm 2 . The authors have determined the LoD for this system using ELISA, XPS, and ToF-SIMS with multivariate analyses, with ToF-SIMS offering an order of magnitude better detection over ELISA and 2 orders of magnitude better detection over XPS.

  17. Production, Characterization and Use of Monoclonal Antibodies Recognizing IgY Epitopes Shared by Chicken, Turkey, Pheasant, Peafowl and Sparrow

    Directory of Open Access Journals (Sweden)

    Ajda Biček

    2004-01-01

    Full Text Available Chicken antibodies are not only a part of immune defense but are more and more popular commercial products in form of chicken polyclonal, monoclonal or recombinant antibodies. We produced and characterized mouse monoclonal antibodies (mAbs that recognize epitopes located on heavy or light chain of chicken immunoglobulin Y (chIgY shared also by some other Phasianidae birds. The use of mAbs 1F5 and 2F10 that recognize heavy chain on chIgY common epitopes was demonstrated on immunoglobulins of turkey, pheasant and peafowl. Chicken IgY light chain specific mAb 3E10 revealed the presence of common epitopes on immunoglobulins of turkey, pheasant and sparrow. Monoclonal antibody clone 1F5/3G2 was used to prepare horseradish peroxidase (HRP conjugate and immunoadsorbent column. Conjugated mAbs were demonstrated to be excellent secondary antibodies for diagnostics of certain infections in different avian species. Since they do not react with mammalian immunoglobulins using our mAbs as secondary antibodies in human serodiagnostics would minimize background staining that appears when using mouse detection system. In dot immunobinding assay (DIBA and immunoblot assay they recognized specific IgY antibodies against Mycoplasma synoviae, Mycoplasma gallisepticum and Newcastle disease virus in sera of infected or vaccinated birds. Immunoadsorption as a method for removal of IgY from samples in which Mycoplasma synoviae specific IgY was predominant immunoglobulin class enabled more exact demonstration of specific IgA and IgM antibodies. Herein we are presenting effective mAbs useful in diagnostics of avian and mammalian infections as well as in final steps of detection and purification of chicken antibodies and their subunits produced in vivo or in vitro as polyclonal, monoclonal or recombinant antibodies.

  18. Synthesis of gold and silver nanoparticle S-ovalbumin protein conjugates by in situ conjugation process

    Science.gov (United States)

    Joshi, Deepti; Soni, R. K.

    2015-05-01

    Pure gold and silver nanoparticle (NP) generation and their conjugation with protein S-ovalbumin using in situ conjugation process have been reported. The in situ conjugation involves nanosecond pulse laser ablation of pure metal target in the protein S-ovalbumin solution. Transmission electron microscopy (TEM) and UV-Visible absorption results show decrease in mean NP size along with narrow particle size distribution on ablation in S-ovalbumin solution as compared to ablation in water for both Au and Ag NPs. Also, the NP size reduction was found to be dependent on the concentration of S-ovalbumin. For AuNPs, spherical NPs of mean size 4 nm with particle size distribution 2-6 nm were obtained at 300 nM S-ovalbumin concentration. Further, it has been observed that the resultant in situ-conjugated colloid gold and silver NP solutions were quite stable even in the presence of NaCl at physiological salt concentration (0.15 M). On post-laser irradiation (532 nm, 15 mJ) for 20 min, 9 nm red shift in surface plasmon resonance peak (SPR), along with increased broadening towards longer wavelength, was observed in the AuNPs-S-ovalbumin sample. Further increase in the time of irradiation showed shift in AuNPs-S-ovalbumin SPR towards lower wavelength. On laser irradiation (532 nm, 15 mJ) for 20 min, no significant change was observed in the line shape of the plasmon absorption band of the AgNPs-S-ovalbumin conjugate. FTIR spectra revealed that S-ovalbumin peptide backbone and secondary structure remain unchanged on laser irradiation during in situ conjugation process. Thus, integrity of S-ovalbumin does not get affected, and no degradation of S-ovalbumin takes place on laser-induced in situ conjugation. Raman results confirm that both Au and Ag NPs interact with S-ovalbumin via thiol-bearing cysteine residues of the disulfide bond.

  19. High-dimensional assessment of B-cell responses to quadrivalent meningococcal conjugate and plain polysaccharide vaccine.

    Science.gov (United States)

    O'Connor, Daniel; Clutterbuck, Elizabeth A; Thompson, Amber J; Snape, Matthew D; Ramasamy, Maheshi N; Kelly, Dominic F; Pollard, Andrew J

    2017-01-30

    Neisseria meningitidis is a globally important cause of meningitis and septicaemia. Twelve capsular groups of meningococci are known, and quadrivalent vaccines against four of these (A, C, W and Y) are available as plain-polysaccharide and protein-polysaccharide conjugate vaccines. Here we apply contemporary methods to describe B-cell responses to meningococcal polysaccharide and conjugate vaccines. Twenty adults were randomly assigned to receive either a meningococcal plain-polysaccharide or conjugate vaccine; one month later all received the conjugate vaccine. Blood samples were taken pre-vaccination and 7, 21 and 28 days after vaccination; B-cell responses were assessed by ELISpot, serum bactericidal assay, flow cytometry and gene expression microarray. Seven days after an initial dose of either vaccine, a gene expression signature characteristic of plasmablasts was detectable. The frequency of newly generated plasma cells (CXCR3 + HLA-DR + ) and the expression of transcripts derived from IGKC and IGHG2 correlated with immunogenicity. Notably, using an independent dataset, the expression of glucosamine (N-acetyl)-6-sulfatase was found to reproducibly correlate with the magnitude of immune response. Transcriptomic and flow cytometric data revealed depletion of switched memory B cells following plain-polysaccharide vaccine. These data describe distinct gene signatures associated with the production of high-avidity antibody and a plain-polysaccharide-specific signature, possibly linked to polysaccharide-induced hyporesponsiveness.

  20. Increase in acrolein-conjugated immunoglobulins in saliva from patients with primary Sjögren's syndrome.

    Science.gov (United States)

    Hirose, Tadao; Saiki, Ryotaro; Uemura, Takeshi; Suzuki, Takehiro; Dohmae, Naoshi; Ito, Satoshi; Takahashi, Hoyu; Ishii, Itsuko; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

    2015-10-23

    We previously reported that the level of protein-conjugated acrolein (PC-Acro), a marker of cell or tissue damage, was increased in saliva from patients with primary Sjögren's syndrome (pSS), and that the level of PC-Acro was well correlated with the severity of pSS. Acrolein-conjugated immunoglobulins were measured in saliva from pSS patients. The activities of autoantibodies recognizing Sjögren's syndrome SSA (Ro) and SSB (La) proteins in saliva from pSS patients were approximately 3- to 5-fold higher than those from control subjects. We also found that autoantibody activities recognizing SSA (Ro) and SSB (La) proteins increased after acrolein treatment of saliva from control subjects. When an antibody against human serum albumin was treated with acrolein, the ability to recognize albumin was reduced but the ability to recognize other proteins was increased. Twenty-four and eleven kinds of acrolein-conjugated amino acids were found at the variable and constant regions of peptides, respectively, obtained from the immunoglobulins in saliva from pSS patients. The altered recognition patterns of immunoglobulins due to acrolein conjugation are at least partially involved in autoimmune diseases. Copyright © 2015 Elsevier B.V. All rights reserved.