WorldWideScience

Sample records for heavy chain antibodies

  1. Heavy chain only antibodies

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud

    2013-01-01

    Unlike conventional antibodies, heavy chain only antibodies derived from camel contain a single variable domain (VHH) and two constant domains (CH2 and CH3). Cloned and isolated VHHs possess unique properties that enable them to excel conventional therapeutic antibodies and their smaller antigen...

  2. Stability of llama heavy chain antibody fragments under extreme conditions

    NARCIS (Netherlands)

    Dolk, E.

    2004-01-01

    Camelids have next to their normal antibodies, a unique subset of antibodies lacking light chains. The resulting single binding domain, VHH, of these heavy chain antibodies consequently have unique properties. A high stability is one of these properties, which was investigated in this thesis. The

  3.  Variable fragments of heavy chain antibodies (VHHs: a new magic bullet molecule of medicine?

    Directory of Open Access Journals (Sweden)

    Dorota Smolarek

    2012-06-01

    Full Text Available  Serum of animals belonging to the Camelidae family (camels and llamas contains fully active antibodies that are naturally devoid of light chains. Variable domains derived from heavy chain antibodies (hcAb called VHHs or nanobodies™ can bind antigens as effectively as full-length antibodies and are easy to clone and express. Because of their potential, VHHs are being intensively studied as potential therapeutic, diagnostic and imaging tools. The paper reviews the molecular background of heavy chain antibodies and describes methods of obtaining recombinant fragments of heavy chain antibodies as well as their therapeutic, diagnostic and other applications.

  4. 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

  5. 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

  6. The association of heavy and light chain variable domains in antibodies: implications for antigen specificity.

    KAUST Repository

    Chailyan, Anna

    2011-06-28

    The antigen-binding site of immunoglobulins is formed by six regions, three from the light and three from the heavy chain variable domains, which, on association of the two chains, form the conventional antigen-binding site of the antibody. The mode of interaction between the heavy and light chain variable domains affects the relative position of the antigen-binding loops and therefore has an effect on the overall conformation of the binding site. In this article, we analyze the structure of the interface between the heavy and light chain variable domains and show that there are essentially two different modes for their interaction that can be identified by the presence of key amino acids in specific positions of the antibody sequences. We also show that the different packing modes are related to the type of recognized antigen.

  7. Antibody Heavy Chain Variable Domains of Different Germline Gene Origins Diversify through Different Paths

    Directory of Open Access Journals (Sweden)

    Ufuk Kirik

    2017-11-01

    Full Text Available B cells produce antibodies, key effector molecules in health and disease. They mature their properties, including their affinity for antigen, through hypermutation events; processes that involve, e.g., base substitution, codon insertion and deletion, often in association with an isotype switch. Investigations of antibody evolution define modes whereby particular antibody responses are able to form, and such studies provide insight important for instance for development of efficient vaccines. Antibody evolution is also used in vitro for the design of antibodies with improved properties. To better understand the basic concepts of antibody evolution, we analyzed the mutational paths, both in terms of amino acid substitution and insertions and deletions, taken by antibodies of the IgG isotype. The analysis focused on the evolution of the heavy chain variable domain of sets of antibodies, each with an origin in 1 of 11 different germline genes representing six human heavy chain germline gene subgroups. Investigated genes were isolated from cells of human bone marrow, a major site of antibody production, and characterized by next-generation sequencing and an in-house bioinformatics pipeline. Apart from substitutions within the complementarity determining regions, multiple framework residues including those in protein cores were targets of extensive diversification. Diversity, both in terms of substitutions, and insertions and deletions, in antibodies is focused to different positions in the sequence in a germline gene-unique manner. Altogether, our findings create a framework for understanding patterns of evolution of antibodies from defined germline genes.

  8. Expression and production of llama variable heavy-chain antibody fragments (VHHs) by Aspergillus awamori

    NARCIS (Netherlands)

    Joosten, V.; Gouka, R.J.; Hondel, C.A.M.J.J. van den; Verrips, C.T.; Lokman, B.C.

    2005-01-01

    We report the expression and production of llama variable heavy-chain antibody fragments (VHHs) by Aspergillus awamori. Fragments encoding VHHs were cloned in a suitable Aspergillus expression vector and transformants secreting VHH fragments were analysed for integrated gene copy-numbers, mRNA

  9. Improved production and function of llama heavy chain antibody fragments by molecular evolution

    NARCIS (Netherlands)

    Linden, van der R.H.; Geus, de B.; Frenken, G.J.; Peters, H.; Verrips, C.T.

    2000-01-01

    The aim of this study was to improve production level of llama heavy chain antibody fragments (V (HH)) in Saccharomyces cerevisiae while retaining functional characteristics. For this purpose, the DNA shuffling technique was used on llama V (HH) fragments specific for the azo-dye reactive red-6. In

  10. Heavy Chain Diseases

    Science.gov (United States)

    ... of heavy chain produced: Alpha Gamma Mu Alpha Heavy Chain Disease Alpha heavy chain disease (IgA heavy ... the disease or lead to a remission. Gamma Heavy Chain Disease Gamma heavy chain disease (IgG heavy ...

  11. Porous silicon biosensor for detection of variable domain of heavy-chain of HCAb antibody

    Science.gov (United States)

    Zhang, Hong-yan; Lü, Xiao-yi; Jia, Zhen-hong; Li, Jiang-wei; Zhang, Fu-chun

    2012-03-01

    In this paper, we produce porous silicon (PSi) by electrochemical etching, and it is the first time to evaluate the performance of label-free porous silicon biosensor for detection of variable domain of heavy chain of heavy-chain antibody (VHH). The binding of hen egg white lysozyme (HEWL) and VHH causes a red shift in the reflection spectrum of the biosensor. The red shift is proportional to the VHH concentration in the range from 14 g·ml-1 to 30 g·ml-1 with a detection limit of 0.648 ng·ml-1. The research is useful for the development of label-free biosensor applied in the rapid and sensitive determination of small molecules.

  12. Generation of human scFv antibody libraries: PCR amplification and assembly of light- and heavy-chain coding sequences.

    Science.gov (United States)

    Andris-Widhopf, Jennifer; Steinberger, Peter; Fuller, Roberta; Rader, Christoph; Barbas, Carlos F

    2011-09-01

    The development of therapeutic antibodies for use in the treatment of human diseases has long been a goal for many researchers in the antibody field. One way to obtain these antibodies is through phage-display libraries constructed from human lymphocytes. This protocol describes the construction of human scFv (single chain antibody fragment) libraries using a short linker (GGSSRSS) or a long linker (GGSSRSSSSGGGGSGGGG). In this method, the individual rearranged heavy- and light-chain variable regions are amplified separately and are linked through a series of overlap polymerase chain reaction (PCR) steps to give the final scFv products that are used for cloning.

  13. Generation and Characterization of Polyclonal Antibody Against Part of Immunoglobulin Constant Heavy υ Chain of Goose

    Science.gov (United States)

    Zhao, Panpan; Guo, Yongli; Ma, Bo; Wang, Junwei

    2014-01-01

    Immunoglobulin Y (abbreviated as IgY) is a type of immunoglobulin that is the major antibody in bird, reptile, and lungfish blood. IgY consists of two light (λ) and two heavy (υ) chains. In the present study, polyclonal antibody against IgYFc was generated and evaluated. rIgYCυ3/Cυ4 was expressed in Escherichia coli, purified and utilized to raise polyclonal antibody in rabbit. High affinity antisera were obtained, which successfully detected the antigen at a dilution of 1:204,800 for ELISA assay. The antibody can specifically recognize both rIgYCυ3/Cυ4 and native IgY by Western bolt analysis. Furthermore, the serum of Grus japonensis or immunoglobulin of chicken, duck, turkey, and silkie samples and dynamic changes of serum GoIgY after immunogenicity with GPV-VP3-virus-like particles (GPV-VP3-VLPs) can be detected with the anti-GoIgYFc polyclonal antibody. These results suggested that the antibody is valuable for the investigation of biochemical properties and biological functions of GoIgY. PMID:25171010

  14. Determination of allergen specificity by heavy chains in grass pollen allergen-specific IgE antibodies.

    Science.gov (United States)

    Gadermaier, Elisabeth; Flicker, Sabine; Lupinek, Christian; Steinberger, Peter; Valenta, Rudolf

    2013-04-01

    Affinity and clonality of allergen-specific IgE antibodies are important determinants for the magnitude of IgE-mediated allergic inflammation. We sought to analyze the contribution of heavy and light chains of human allergen-specific IgE antibodies for allergen specificity and to test whether promiscuous pairing of heavy and light chains with different allergen specificity allows binding and might affect affinity. Ten IgE Fabs specific for 3 non-cross-reactive major timothy grass pollen allergens (Phl p 1, Phl p 2, and Phl p 5) obtained by means of combinatorial cloning from patients with grass pollen allergy were used to construct stable recombinant single chain variable fragments (ScFvs) representing the original Fabs and shuffled ScFvs in which heavy chains were recombined with light chains from IgE Fabs with specificity for other allergens by using the pCANTAB 5 E expression system. Possible ancestor genes for the heavy chain and light chain variable region-encoding genes were determined by using sequence comparison with the ImMunoGeneTics database, and their chromosomal locations were determined. Recombinant ScFvs were tested for allergen specificity and epitope recognition by means of direct and sandwich ELISA, and affinity by using surface plasmon resonance experiments. The shuffling experiments demonstrate that promiscuous pairing of heavy and light chains is possible and maintains allergen specificity, which is mainly determined by the heavy chains. ScFvs consisting of different heavy and light chains exhibited different affinities and even epitope specificity for the corresponding allergen. Our results indicate that allergen specificity of allergen-specific IgE is mainly determined by the heavy chains. Different heavy and light chain pairings in allergen-specific IgE antibodies affect affinity and epitope specificity and thus might influence clinical reactivity to allergens. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by

  15. Many Routes to an Antibody Heavy-Chain CDR3: Necessary, Yet Insufficient, for Specific Binding

    Science.gov (United States)

    D’Angelo, Sara; Ferrara, Fortunato; Naranjo, Leslie; Erasmus, M. Frank; Hraber, Peter; Bradbury, Andrew R. M.

    2018-01-01

    Because of its great potential for diversity, the immunoglobulin heavy-chain complementarity-determining region 3 (HCDR3) is taken as an antibody molecule’s most important component in conferring binding activity and specificity. For this reason, HCDR3s have been used as unique identifiers to investigate adaptive immune responses in vivo and to characterize in vitro selection outputs where display systems were employed. Here, we show that many different HCDR3s can be identified within a target-specific antibody population after in vitro selection. For each identified HCDR3, a number of different antibodies bearing differences elsewhere can be found. In such selected populations, all antibodies with the same HCDR3 recognize the target, albeit at different affinities. In contrast, within unselected populations, the majority of antibodies with the same HCDR3 sequence do not bind the target. In one HCDR3 examined in depth, all target-specific antibodies were derived from the same VDJ rearrangement, while non-binding antibodies with the same HCDR3 were derived from many different V and D gene rearrangements. Careful examination of previously published in vivo datasets reveals that HCDR3s shared between, and within, different individuals can also originate from rearrangements of different V and D genes, with up to 26 different rearrangements yielding the same identical HCDR3 sequence. On the basis of these observations, we conclude that the same HCDR3 can be generated by many different rearrangements, but that specific target binding is an outcome of unique rearrangements and VL pairing: the HCDR3 is necessary, albeit insufficient, for specific antibody binding. PMID:29568296

  16. Generation of human Fab antibody libraries: PCR amplification and assembly of light- and heavy-chain coding sequences.

    Science.gov (United States)

    Andris-Widhopf, Jennifer; Steinberger, Peter; Fuller, Roberta; Rader, Christoph; Barbas, Carlos F

    2011-09-01

    The development of therapeutic antibodies for use in the treatment of human diseases has long been a goal for many researchers in the antibody field. One way to obtain these antibodies is through phage-display libraries constructed from human lymphocytes. This protocol describes the construction of human Fab (fragment antigen binding) antibody libraries. In this method, the individual rearranged heavy- and light-chain variable regions are amplified separately and are linked through a series of overlap polymerase chain reaction (PCR) steps to give the final Fab products that are used for cloning.

  17. The association of heavy and light chain variable domains in antibodies: implications for antigen specificity.

    KAUST Repository

    Chailyan, Anna; Marcatili, Paolo; Tramontano, Anna

    2011-01-01

    of interaction between the heavy and light chain variable domains affects the relative position of the antigen-binding loops and therefore has an effect on the overall conformation of the binding site. In this article, we analyze the structure of the interface

  18. Imaging of myocardial infarction in dogs and humans using monoclonal antibodies specific for human myosin heavy chains

    International Nuclear Information System (INIS)

    Leger, J.; Chevalier, J.; Larue, C.; Gautier, P.; Planchenault, J.; Aumaitre, E.; Messner, P.; Puech, P.; Saccavini, J.C.; Pau, B.

    1991-01-01

    The use of three different monoclonal antibodies specific for human ventricular myosin heavy chains in the visualization of the location and extent of necrosis in dogs with experimental acute myocardial infarction and in humans is described. Using a classic immunohistochemical method or ex vivo analysis of heart slices in dogs with acute myocardial infarction subjected to intravenous injection of unlabeled antimyosin antibodies or antimyosin antibodies labeled with indium-111, it was observed that all antibody fragments specifically reached the targeted necrotic zone less than 2 h after antibody injection and remained bound for up to 24 h. In a limited but significant number of cases (5 of the 12 humans and 11 of 43 dogs), it was possible to image the necrotic zone in vivo as early as 2 to 4 h after antibody injection. In other cases, individual blood clearance variations retarded or even prevented in vivo necrosis detection. Higher antimyosin fixation values were obtained in the necrotic zones in dogs with a rapid blood clearance relative to that of the other dogs. It is concluded that antimyosin antibodies always reached necrotic areas within 2 h. If blood clearance was rapid, in vivo imaging of the necrotic area was possible 2 to 6 h after necrosis, even in humans. In some cases, however, uncontrolled individual variations in the timing required for sufficient blood clearance hampered this rapid in vivo detection of myocardial necrosis

  19. Homologous recombination in hybridoma cells: heavy chain chimeric antibody produced by gene targeting.

    OpenAIRE

    Fell, H P; Yarnold, S; Hellström, I; Hellström, K E; Folger, K R

    1989-01-01

    We demonstrate that murine myeloma cells can efficiently mediate homologous recombination. The murine myeloma cell line J558L was shown to appropriately recombine two transfected DNA molecules in approximately 30% of cells that received and integrated intact copies of both molecules. This activity was then exploited to direct major reconstructions of an endogenous locus within a hybridoma cell line. Production of antigen-specific chimeric heavy chain was achieved by targeting the human IgG1 h...

  20. Application of monoclonal antibodies in functional and comparative investigations of heavy-chain immunoglobulins in new world camelids.

    Science.gov (United States)

    Daley, L P; Gagliardo, L F; Duffy, M S; Smith, M C; Appleton, J A

    2005-03-01

    Of the three immunoglobulin G (IgG) isotypes described to occur in camelids, IgG2 and IgG3 are distinct in that they do not incorporate light chains. These heavy-chain antibodies (HCAbs) constitute approximately 50% of the IgG in llama serum and as much as 75% of the IgG in camel serum. We have produced isotype-specific mouse monoclonal antibodies (MAbs) in order to investigate the roles of HCAbs in camelid immunity. Seventeen stable hybridomas were cloned, and three MAbs that were specific for epitopes on the gamma chains of llama IgG1, IgG2, or IgG3 were characterized in detail. Affinity chromatography revealed that each MAb bound its isotype in solution in llama serum. The antibodies bound to the corresponding alpaca IgGs, to guanaco IgG1 and IgG2, and to camel IgG1. Interestingly, anti-IgG2 MAbs bound three heavy-chain species in llama serum, confirming the presence of three IgG2 subisotypes. Two IgG2 subisotypes were detected in alpaca and guanaco sera. The MAbs detected llama serum IgGs when they were bound to antigen in enzyme-linked immunosorbent assays and were used to discern among isotypes induced during infection with a parasitic nematode. Diseased animals, infected with Parelaphostrongylus tenuis, did not produce antigen-specific HCAbs; rather, they produced the conventional isotype, IgG1, exclusively. Our data document the utility of these MAbs in functional and physiologic investigations of the immune systems of New World camelids.

  1. Modular Construction of Large Non-Immune Human Antibody Phage-Display Libraries from Variable Heavy and Light Chain Gene Cassettes.

    Science.gov (United States)

    Lee, Nam-Kyung; Bidlingmaier, Scott; Su, Yang; Liu, Bin

    2018-01-01

    Monoclonal antibodies and antibody-derived therapeutics have emerged as a rapidly growing class of biological drugs for the treatment of cancer, autoimmunity, infection, and neurological diseases. To support the development of human antibodies, various display techniques based on antibody gene repertoires have been constructed over the last two decades. In particular, scFv-antibody phage display has been extensively utilized to select lead antibodies against a variety of target antigens. To construct a scFv phage display that enables efficient antibody discovery, and optimization, it is desirable to develop a system that allows modular assembly of highly diverse variable heavy chain and light chain (Vκ and Vλ) repertoires. Here, we describe modular construction of large non-immune human antibody phage-display libraries built on variable gene cassettes from heavy chain and light chain repertoires (Vκ- and Vλ-light can be made into independent cassettes). We describe utility of such libraries in antibody discovery and optimization through chain shuffling.

  2. Expression cloning and production of human heavy-chain-only antibodies from murine transgenic plasma cells

    NARCIS (Netherlands)

    D.D. Drabek (Dubravka); R. Janssens (Rick); Boer, E. (Ernie de); Rademaker, R. (Rik); Kloess, J. (Johannes); J.J. Skehel (John ); Grosveld, F. (Frank)

    2016-01-01

    textabstractSeveral technologies have been developed to isolate human antibodies against different target antigens as a source of potential therapeutics, including hybridoma technology, phage and yeast display systems. For conventional antibodies, this involves either random pairing of VH and

  3. Induced refolding of a temperature denatured llama heavy-chain antibody fragment by its antigen

    NARCIS (Netherlands)

    Dolk, E.; Vliet, C. van; Perez, J.M.J.; Vriend, G.; Darbon, H.; Ferrat, G.; Cambillau, C.; Frenken, L.G.J.; Verrips, T.

    2005-01-01

    In a previous study we have shown that llama VHH antibody fragments are able to bind their antigen after a heat shock of 90°C, in contrast to the murine monoclonal antibodies. However, the molecular mechanism by which antibody:antigen interaction occurs under these extreme conditions remains

  4. Targeting Antibodies to Carbon Nanotube Field Effect Transistors by Pyrene Hydrazide Modification of Heavy Chain Carbohydrates

    Directory of Open Access Journals (Sweden)

    Steingrimur Stefansson

    2012-01-01

    Full Text Available Many carbon nanotube field-effect transistor (CNT-FET studies have used immobilized antibodies as the ligand binding moiety. However, antibodies are not optimal for CNT-FET detection due to their large size and charge. Their size can prevent ligands from reaching within the Debye length of the CNTs and a layer of charged antibodies on the circuits can drown out any ligand signal. In an attempt to minimize the antibody footprint on CNT-FETs, we examined whether pyrene hydrazide modification of antibody carbohydrates could reduce the concentration required to functionalize CNT circuits. The carbohydrates are almost exclusively on the antibody Fc region and this site-specific modification could mediate uniform antibody orientation on the CNTs. We compared the hydrazide modification of anti-E. coli O157:H7 polyclonal antibodies to pyrenebutanoic acid succinimidyl ester-coated CNTs and carbodiimide-mediated antibody CNT attachment. Our results show that the pyrene hydrazide modification was superior to those methods with respect to bacteria detection and less than 1 nM labeled antibody was required to functionalize the circuits.

  5. Production of bifunctional proteins by Aspergillus awamori: Llama variable heavy chain antibody fragment (V-HH) R9 coupled to Arthromyces ramosus peroxidase (ARP)

    NARCIS (Netherlands)

    Joosten, V.; Roelofs, M.S.; Dries, van den N.; Goosen, T.; Verrips, C.T.; Hondel, van den C.A.M.J.J.; Lokman, B.C.

    2005-01-01

    The Arthromyces ramosus peroxidase gene (arp) was genetically fused to either the 5'- or 3'-terminal ends of the gene encoding llama variable heavy chain antibody fragment V-HH R9, resulting in the fusion expression cassettes ARP-R9 or R9-ARP. Aspergillus awamori transformants were obtained which

  6. Production of bifunctional proteins by Aspergillus awamori: Llama variable heavy chain antibody fragment (VHH) R9 coupled to Arthromyces ramosus peroxidase (ARP)

    NARCIS (Netherlands)

    Joosten, V.; Roelofs, M.S.; Dries, N. van den; Goosen, T.; Verrips, C.T.; Hondel, C.A.M.J.J. van den; Lokman, B.C.

    2005-01-01

    The Arthromyces ramosus peroxidase gene (arp) was genetically fused to either the 5′- or 3′-terminal ends of the gene encoding llama variable heavy chain antibody fragment VHH R9, resulting in the fusion expression cassettes ARP-R9 or R9-ARP. Aspergillus awamori transformants were obtained which

  7. Improving the accuracy of the structure prediction of the third hypervariable loop of the heavy chains of antibodies.

    KAUST Repository

    Messih, Mario Abdel; Lepore, Rosalba; Marcatili, Paolo; Tramontano, Anna

    2014-01-01

    MOTIVATION: Antibodies are able to recognize a wide range of antigens through their complementary determining regions formed by six hypervariable loops. Predicting the 3D structure of these loops is essential for the analysis and reengineering of novel antibodies with enhanced affinity and specificity. The canonical structure model allows high accuracy prediction for five of the loops. The third loop of the heavy chain, H3, is the hardest to predict because of its diversity in structure, length and sequence composition. RESULTS: We describe a method, based on the Random Forest automatic learning technique, to select structural templates for H3 loops among a dataset of candidates. These can be used to predict the structure of the loop with a higher accuracy than that achieved by any of the presently available methods. The method also has the advantage of being extremely fast and returning a reliable estimate of the model quality. AVAILABILITY AND IMPLEMENTATION: The source code is freely available at http://www.biocomputing.it/H3Loopred/ .

  8. Improving the accuracy of the structure prediction of the third hypervariable loop of the heavy chains of antibodies.

    KAUST Repository

    Messih, Mario Abdel

    2014-06-13

    MOTIVATION: Antibodies are able to recognize a wide range of antigens through their complementary determining regions formed by six hypervariable loops. Predicting the 3D structure of these loops is essential for the analysis and reengineering of novel antibodies with enhanced affinity and specificity. The canonical structure model allows high accuracy prediction for five of the loops. The third loop of the heavy chain, H3, is the hardest to predict because of its diversity in structure, length and sequence composition. RESULTS: We describe a method, based on the Random Forest automatic learning technique, to select structural templates for H3 loops among a dataset of candidates. These can be used to predict the structure of the loop with a higher accuracy than that achieved by any of the presently available methods. The method also has the advantage of being extremely fast and returning a reliable estimate of the model quality. AVAILABILITY AND IMPLEMENTATION: The source code is freely available at http://www.biocomputing.it/H3Loopred/ .

  9. Activity modulation of microbial enzymes by llama (Lama glama) heavy-chain polyclonal antibodies during in vivo immune responses.

    Science.gov (United States)

    Ferrari, A; Weill, F S; Paz, M L; Cela, E M; González Maglio, D H; Leoni, J

    2012-03-01

    Since they were first described in 1993, it was found that recombinant variable fragments (rVHHs) of heavy-chain antibodies (HCAbs) from Camelidae have unusual biophysical properties, as well as a special ability to interact with epitopes that are cryptic for conventional Abs. It has been assumed that in vivo raised polyclonal HCAbs (pHCAbs) should behave in a similar manner than rVHHs; however, this assumption has not been tested sufficiently. Furthermore, our own preliminary work on a single serum sample from a llama immunized with a β-lactamase, has suggested that pHCAbs have no special ability to down-modulate catalytic activity. In this work, we further explored the interaction of pHCAbs from four llamas raised against two microbial enzymes and analyzed it within a short and a long immunization plan. The relative contribution of pHCAbs to serum titer was found to be low compared with that of the most abundant conventional subisotype (IgG(1)), during the whole immunization schedule. Furthermore, pHCAbs not only failed to inhibit the enzymes, but also activated one of them. Altogether, these results suggest that raising high titer inhibitory HCAbs is not a straightforward strategy - neither as a biotechnological strategy nor in the biological context of an immune response against infection - as raising inhibitory rVHHs.

  10. High production of llama variable heavy-chain antibody fragment (VHH) fused to various reader proteins by Aspergillus oryzae.

    Science.gov (United States)

    Hisada, Hiromoto; Tsutsumi, Hiroko; Ishida, Hiroki; Hata, Yoji

    2013-01-01

    Llama variable heavy-chain antibody fragment (VHH) fused to four different reader proteins was produced and secreted in culture medium by Aspergillus oryzae. These fusion proteins consisted of N-terminal reader proteins, VHH, and a C-terminal his-tag sequence which facilitated purification using one-step his-tag affinity chromatography. SDS-PAGE analysis of the deglycosylated purified fusion proteins confirmed that the molecular weight of each corresponded to the expected sum of VHH and the respective reader proteins. The apparent high molecular weight reader protein glucoamylase (GlaB) was found to be suitable for efficient VHH production. The GlaB-VHH-His protein bound its antigen, human chorionic gonadotropin, and was detectable by a new ELISA-based method using a coupled assay with glucoamylase, glucose oxidase, peroxidase, maltose, and 3,3',5,5'-tetramethylbenzidine as substrates. Addition of potassium phosphate to the culture medium induced secretion of 0.61 mg GlaB-VHH-His protein/ml culture medium in 5 days.

  11. 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 D...... of natural HibCP antibodies (r = 0.59; P = 0.00002). A possible role of natural exposure for Hib or cross-reactive bacteria on the mucosal surfaces in the shaping of the isotype response to HibCP conjugate vaccines is discussed....

  12. Immune recognition of botulinum neurotoxin B: antibody-binding regions on the heavy chain of the toxin.

    Science.gov (United States)

    Dolimbek, Behzod Z; Steward, Lance E; Aoki, K Roger; Atassi, M Zouhair

    2008-02-01

    The purpose of this work was to map the continuous regions recognized by human, horse and mouse anti-botulinum neurotoxin B (BoNT/B) antibodies (Abs). We synthesized a panel of sixty 19-residue peptides (peptide C31 was 24 residues) that overlapped consecutively by 5 residues and together encompassed the entire heavy chain of BoNT/B (H/B, residues 442-1291). Abs from the three host species recognized similar, but not identical, peptides. There were also peptides recognized by two or only by one host species. Where a peptide was recognized by Abs of more than one host species, these Abs were at different levels among the species. Human, horse and mouse Abs bound, although in different amounts, to regions within peptides 736-754, 778-796, 848-866, 932-950, 974-992, 1058-1076 and 1128-1146. Human and horse Abs bound to peptides 890-908 and 1170-1188. Human and mouse Abs recognized peptides 470-488/484-502 overlap, 638-656, 722-740, 862-880, 1030-1048, 1072-1090, 1240-1258 and 1268-1291. We concluded that the antigenic regions localized with the three antisera are quite similar, exhibiting in some cases a small shift to the left or to the right. This is consistent with what is known about protein immune recognition. In the three-dimensional structure, the regions recognized on H/B by anti-BoNT/B Abs occupied surface locations and analysis revealed no correlation between these surface locations and surface electrostatic potential, hydrophilicity, hydrophobicity, or temperature factor. A region that bound mouse Abs overlapped with a recently defined site on BoNT/B that binds to mouse and rat synaptotagmin II, thus providing a molecular explanation for the blocking (protecting) activity of these Abs. The regions thus localized afford candidates for incorporation into a synthetic vaccine design.

  13. A shark antibody heavy chain encoded by a nonsomatically rearranged VDJ is preferentially expressed in early development and is convergent with mammalian IgG.

    Science.gov (United States)

    Rumfelt, L L; Avila, D; Diaz, M; Bartl, S; McKinney, E C; Flajnik, M F

    2001-02-13

    In most vertebrate embryos and neonates studied to date unique antigen receptors (antibodies and T cell receptors) are expressed that possess a limited immune repertoire. We have isolated a subclass of IgM, IgM(1gj), from the nurse shark Ginglymostoma cirratum that is preferentially expressed in neonates. The variable (V) region gene encoding the heavy (H) chain underwent V-D-J rearrangement in germ cells ("germline-joined"). Such H chain V genes were discovered over 10 years ago in sharks but until now were not shown to be expressed at appreciable levels; we find expression of H(1gj) in primary and secondary lymphoid tissues early in life, but in adults only in primary lymphoid tissue, which is identified in this work as the epigonal organ. H(1gj) chain associates covalently with light (L) chains and is most similar in sequence to IgM H chains, but like mammalian IgG has three rather than the four IgM constant domains; deletion of the ancestral IgM C2 domain thus defines both IgG and IgM(1gj). Because sharks are the members of the oldest vertebrate class known to possess antibodies, unique or specialized antibodies expressed early in ontogeny in sharks and other vertebrates were likely present at the inception of the adaptive immune system.

  14. Sequences of the joining region genes for immunoglobulin heavy chains and their role in generation of antibody diversity.

    OpenAIRE

    Gough, N M; Bernard, O

    1981-01-01

    To assess the contribution to immunoglobulin heavy chain diversity made by recombination between variable region (VH) genes and joining region (JH) genes, we have determined the sequence of about 2000 nucleotides spanning the rearranged JH gene cluster associated with the VH gene expressed in plasmacytoma HPC76. The active VH76 gene has recombined with the second germ-line JH gene. The region we have studied contains two other JH genes, designated JH3 and JH4. No other JH gene was found withi...

  15. Efficient heterologous expression and secretion in Aspergillus oryzae of a llama variable heavy-chain antibody fragment V(HH) against EGFR.

    Science.gov (United States)

    Okazaki, Fumiyoshi; Aoki, Jun-ichi; Tabuchi, Soichiro; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

    2012-10-01

    We have constructed a filamentous fungus Aspergillus oryzae that secretes a llama variable heavy-chain antibody fragment (V(HH)) that binds specifically to epidermal growth factor receptor (EGFR) in a culture medium. A major improvement in yield was achieved by fusing the V(HH) with a Taka-amylase A signal sequence (sTAA) and a segment of 28 amino acids from the N-terminal region of Rhizopus oryzae lipase (N28). The yields of secreted, immunologically active anti-EGFR V(HH) reached 73.8 mg/1 in a Sakaguchi flask. The V(HH) fragments were released from the sTAA or N28 proteins by an indigenous A. oryzae protease during cultivation. The purified recombinant V(HH) fragment was specifically recognized and could bind to the EGFR with a high affinity.

  16. A monoclonal antibody distinguishes between two IgM heavy chain isotypes in Atlantic salmon and brown trout: protein characterization, 3D modeling and epitope mapping.

    Science.gov (United States)

    Kamil, Atif; Falk, Knut; Sharma, Animesh; Raae, Arnt; Berven, Frode; Koppang, Erling Olaf; Hordvik, Ivar

    2011-09-01

    Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) possess two distinct subpopulations of IgM which can be separated by anion exchange chromatography. Accordingly, there are two isotypic μ genes in these species, related to ancestral tetraploidy. In the present work it was verified by mass spectrometry that IgM of peak 1 (subpopulation 1) have heavy chains previously designated as μB type whereas IgM of peak 2 (subpopulation 2) have heavy chains of μA type. Two adjacent cysteine residues are present near the C-terminal part of μB, in contrast to one cysteine residue in μA. Salmon IgM of both peak 1 and peak 2 contain light chains of the two most common isotypes: IgL1 and IgL3. In contrast to salmon and brown trout, IgM of rainbow trout (Oncorhynchus mykiss) is eluted in a single peak when subjected to anion exchange chromatography. Surprisingly, a monoclonal antibody MAb4C10 against rainbow trout IgM, reacted with μA in salmon, whereas in brown trout it reacted with μB. It is plausible to assume that DNA has been exchanged between the paralogous A and B loci during evolution while maintaining the two sub-variants, with and without the extra cysteine. MAb4C10 was conjugated to magnetic beads and used to separate cells, demonstrating that μ transcripts residing from captured cells were primarily of A type in salmon and B type in brown trout. An analysis of amino acid substitutions in μA and μB of salmon and brown trout indicated that the third constant domain is essential for MAb4C10 binding. This was supported by 3D modeling and was finally verified by studies of MAb4C10 reactivity with a series of recombinant μ3 constructs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Cloning of the immunological repertoire in Escherichia coli for generation of monoclonal catalytic antibodies: construction of a heavy chain variable region-specific cDNA library.

    OpenAIRE

    Sastry, L; Alting-Mees, M; Huse, W D; Short, J M; Sorge, J A; Hay, B N; Janda, K D; Benkovic, S J; Lerner, R A

    1989-01-01

    Efficient generation of catalytic antibodies is uniquely dependent on the exact nature of the binding interactions in the antigen-antibody complex. Current methods for generation of monoclonal antibodies do not efficiently survey the immunological repertoire and, therefore, they limit the number of catalysts that can be obtained. We are exploring methods to clone and express the immunological repertoire in Escherichia coli. As the essential first step, we present here a method for the establi...

  18. The Glycosylphosphatidylinositol-Anchored Variable Region of Llama Heavy Chain-Only Antibody JM4 Efficiently Blocks both Cell-Free and T Cell-T Cell Transmission of Human Immunodeficiency Virus Type 1.

    Science.gov (United States)

    Liu, Lihong; Wang, Weiming; Matz, Julie; Ye, Chaobaihui; Bracq, Lucie; Delon, Jerome; Kimata, Jason T; Chen, Zhiwei; Benichou, Serge; Zhou, Paul

    2016-12-01

    The variable regions (VHHs) of two heavy chain-only antibodies, JM2 and JM4, from llamas that have been immunized with a trimeric gp140 bound to a CD4 mimic have been recently isolated (here referred to as VHH JM2 and VHH JM4, respectively). JM2 binds the CD4-binding site of gp120 and neutralizes HIV-1 strains from subtypes B, C, and G. JM4 binds gp120 and neutralizes HIV-1 strains from subtypes A, B, C, A/E, and G in a CD4-dependent manner. In the present study, we constructed glycosylphosphatidylinositol (GPI)-anchored VHH JM2 and JM4 along with an E4 control and transduced them into human CD4 + cell lines and primary CD4 T cells. We report that by genetically linking the VHHs with a GPI attachment signal, VHHs are targeted to the lipid rafts of the plasma membranes. Expression of GPI-VHH JM4, but not GPI-VHH E4 and JM2, on the surface of transduced TZM.bl cells potently neutralizes multiple subtypes of HIV-1 isolates, including tier 2 or 3 strains, transmitted founders, quasispecies, and soluble single domain antibody (sdAb) JM4-resistant viruses. Moreover, transduction of CEMss-CCR5 cells with GPI-VHH JM4, but not with GPI-VHH E4, confers resistance to both cell-free and T cell-T cell transmission of HIV-1 and HIV-1 envelope-mediated fusion. Finally, GPI-VHH JM4-transduced human primary CD4 T cells efficiently resist both cell-free and T cell-T cell transmission of HIV-1. Thus, we conclude that VHH JM4, when targeted to the lipid rafts of the plasma membrane, efficiently neutralizes HIV-1 infection via both cell-free and T cell-T cell transmission. Our findings should have important implications for GPI-anchored antibody-based therapy against HIV-1. Lipid rafts are specialized dynamic microdomains of the plasma membrane and have been shown to be gateways for HIV-1 budding as well as entry into T cells and macrophages. In nature, many glycosylphosphatidylinositol (GPI)-anchored proteins localize in the lipid rafts. In the present study, we developed GPI

  19. RECOMBINATION OF ANTIBODY POLYPEPTIDE CHAINS IN THE PRESENCE OF ANTIGEN

    Science.gov (United States)

    Metzger, Henry; Mannik, Mart

    1964-01-01

    Conditions were developed by which the separated H and L chains of gamma2 globulins recombined to form four-chained molecules in good yields. In the absence of antigen, anti-2,4-dinitrophenyl (anti-DNP) H chains randomly reassociated with a mixture of antibody and non-specific gamma2 globulin L chains. In the presence of a specific hapten, however, the antibody H chains preferentially interacted with the anti-DNP L chains. Antibody H chain-antibody L chain recombinants formed in the presence of hapten were more active than the corresponding recombinants formed in the absence of hapten. Speculations are made regarding the possible mechanisms and biological significance of these effects. PMID:14247718

  20. Mouse myeloma cells that make short immunoglobulin heavy chains: pleiotropic effects on glycosylation and chain assembly

    OpenAIRE

    1984-01-01

    Two variants in immunoglobulin heavy chain production, derived from the MPC 11 mouse myeloma cell line, make short heavy (H) chains with identical precise deletions of the CH3 domain. The CH3 domain is expressed in the H chain mRNA from both variants. Although in vitro translation of this mRNA produces one H chain species, deleted heavy chains are secreted as heavy-light (HL) and H2L2 moieties in contrast to MPC 11, which secretes only H2L2 . The heavy chains of HL apparently contain more car...

  1. Translocations affecting human immunoglobulin heavy chain locus

    Directory of Open Access Journals (Sweden)

    Sklyar I. V.

    2014-03-01

    Full Text Available Translocations involving human immunoglobulin heavy chain (IGH locus are implicated in different leukaemias and lymphomas, including multiple myeloma, mantle cell lymphoma, Burkitt’s lymphoma and diffuse large B cell lymphoma. We have analysed published data and identified eleven breakpoint cluster regions (bcr related to these cancers within the IgH locus. These ~1 kbp bcrs are specific for one or several types of blood cancer. Our findings could help devise PCR-based assays to detect cancer-related translocations, to identify the mechanisms of translocations and to help in the research of potential translocation partners of the immunoglobulin locus at different stages of B-cell differentiation.

  2. High-throughput sequencing of natively paired antibody chains provides evidence for original antigenic sin shaping the antibody response to influenza vaccination.

    Science.gov (United States)

    Tan, Yann-Chong; Blum, Lisa K; Kongpachith, Sarah; Ju, Chia-Hsin; Cai, Xiaoyong; Lindstrom, Tamsin M; Sokolove, Jeremy; Robinson, William H

    2014-03-01

    We developed a DNA barcoding method to enable high-throughput sequencing of the cognate heavy- and light-chain pairs of the antibodies expressed by individual B cells. We used this approach to elucidate the plasmablast antibody response to influenza vaccination. We show that >75% of the rationally selected plasmablast antibodies bind and neutralize influenza, and that antibodies from clonal families, defined by sharing both heavy-chain VJ and light-chain VJ sequence usage, do so most effectively. Vaccine-induced heavy-chain VJ regions contained on average >20 nucleotide mutations as compared to their predicted germline gene sequences, and some vaccine-induced antibodies exhibited higher binding affinities for hemagglutinins derived from prior years' seasonal influenza as compared to their affinities for the immunization strains. Our results show that influenza vaccination induces the recall of memory B cells that express antibodies that previously underwent affinity maturation against prior years' seasonal influenza, suggesting that 'original antigenic sin' shapes the antibody response to influenza vaccination. Published by Elsevier Inc.

  3. Modelling antibody side chain conformations using heuristic database search.

    Science.gov (United States)

    Ritchie, D W; Kemp, G J

    1997-01-01

    We have developed a knowledge-based system which models the side chain conformations of residues in the variable domains of antibody Fv fragments. The system is written in Prolog and uses an object-oriented database of aligned antibody structures in conjunction with a side chain rotamer library. The antibody database provides 3-dimensional clusters of side chain conformations which can be copied en masse into the model structure. The object-oriented database architecture facilitates a navigational style of database access, necessary to assemble side chains clusters. Around 60% of the model is built using side chain clusters and this eliminates much of the combinatorial complexity associated with many other side chain placement algorithms. Construction and placement of side chain clusters is guided by a heuristic cost function based on a simple model of side chain packing interactions. Even with a simple model, we find that a large proportion of side chain conformations are modelled accurately. We expect our approach could be used with other homologous protein families, in addition to antibodies, both to improve the quality of model structures and to give a "smart start" to the side chain placement problem.

  4. Myeloma-Derived Light Chain Paired with a Diagnostic Monoclonal Antibody Hinders Immunoassay Performance.

    Science.gov (United States)

    Tu, Bailin; Tieman, Bryan; Moore, Jeffrey; Pan, You; Muerhoff, A Scott

    2017-06-01

    Monoclonal antibodies are widely used as the capture and detection reagents in diagnostic immunoassays. In the past, myeloma fusion partners expressing endogenous heavy and/or light chains were often used to generate hybridoma cell lines. As a result, mixed populations of antibodies were produced that can cause inaccurate test results, poor antibody stability, and significant lot-to-lot variability. We describe one such scenario where the P3U1 (P3X63Ag8U.1) myeloma fusion partner was used in the generation of a hybridoma producing protein induced vitamin K absence/antagonist-II (PIVKA II) antibody. The hybridoma produces three subpopulations of immunoglobulin as determined by ion exchange (IEx) chromatography that exhibit varying degrees of immunoreactivity (0%, 50%, or 100%) to the target antigen as determined by Surface Plasmon Resonance. To produce an antibody with the highest possible sensitivity and specificity, the antigen-specific heavy and light chain variable domains (VH and VL) were cloned from the hybridoma and tethered to murine IgG1 and kappa scaffolds. The resulting recombinant antibody was expressed in Chinese hamster ovary cells and is compatible for use in a diagnostic immunoassay.

  5. Immunoglobulin heavy chain exclusion in the shark.

    Directory of Open Access Journals (Sweden)

    Karolina Malecek

    2008-06-01

    Full Text Available The adaptive immune system depends on specific antigen receptors, immunoglobulins (Ig in B lymphocytes and T cell receptors (TCR in T lymphocytes. Adaptive responses to immune challenge are based on the expression of a single species of antigen receptor per cell; and in B cells, this is mediated in part by allelic exclusion at the Ig heavy (H chain locus. How allelic exclusion is regulated is unclear; we considered that sharks, the oldest vertebrates possessing the Ig/TCR-based immune system, would yield insights not previously approachable and reveal the primordial basis of the regulation of allelic exclusion. Sharks have an IgH locus organization consisting of 15-200 independently rearranging miniloci (VH-D1-D2-JH-Cmu, a gene organization that is considered ancestral to the tetrapod and bony fish IgH locus. We found that rearrangement takes place only within a minilocus, and the recombining gene segments are assembled simultaneously and randomly. Only one or few H chain genes were fully rearranged in each shark B cell, whereas the other loci retained their germline configuration. In contrast, most IgH were partially rearranged in every thymocyte (developing T cell examined, but no IgH transcripts were detected. The distinction between B and T cells in their IgH configurations and transcription reveals a heretofore unsuspected chromatin state permissive for rearrangement in precursor lymphocytes, and suggests that controlled limitation of B cell lineage-specific factors mediate regulated rearrangement and allelic exclusion. This regulation may be shared by higher vertebrates in which additional mechanistic and regulatory elements have evolved with their structurally complex IgH locus.

  6. Sequence-Based Discovery Demonstrates That Fixed Light Chain Human Transgenic Rats Produce a Diverse Repertoire of Antigen-Specific Antibodies

    Directory of Open Access Journals (Sweden)

    Katherine E. Harris

    2018-04-01

    Full Text Available We created a novel transgenic rat that expresses human antibodies comprising a diverse repertoire of heavy chains with a single common rearranged kappa light chain (IgKV3-15-JK1. This fixed light chain animal, called OmniFlic, presents a unique system for human therapeutic antibody discovery and a model to study heavy chain repertoire diversity in the context of a constant light chain. The purpose of this study was to analyze heavy chain variable gene usage, clonotype diversity, and to describe the sequence characteristics of antigen-specific monoclonal antibodies (mAbs isolated from immunized OmniFlic animals. Using next-generation sequencing antibody repertoire analysis, we measured heavy chain variable gene usage and the diversity of clonotypes present in the lymph node germinal centers of 75 OmniFlic rats immunized with 9 different protein antigens. Furthermore, we expressed 2,560 unique heavy chain sequences sampled from a diverse set of clonotypes as fixed light chain antibody proteins and measured their binding to antigen by ELISA. Finally, we measured patterns and overall levels of somatic hypermutation in the full B-cell repertoire and in the 2,560 mAbs tested for binding. The results demonstrate that OmniFlic animals produce an abundance of antigen-specific antibodies with heavy chain clonotype diversity that is similar to what has been described with unrestricted light chain use in mammals. In addition, we show that sequence-based discovery is a highly effective and efficient way to identify a large number of diverse monoclonal antibodies to a protein target of interest.

  7. Diversity Analysis of the Immunoglobulin M Heavy Chain Gene in ...

    African Journals Online (AJOL)

    A full-length cDNA encoding the immunoglobulin (IgM) heavy chain gene of Nile tilapia was successfully cloned using the 5' and 3' RACE techniques. The complete cDNA of the Nile tilapia IgM heavy chain gene is 1,921 bp in length and has an open reading frame (ORF) of 1,740 bp, which corresponds to 580 amino acid ...

  8. Sensitive chain specific radioimmunoassay for human immunoglobulins using monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, K; Alderson, T St.J.; Ellis, J [Ludwig Institute for Cancer Research, Cambridge (UK)

    1983-02-25

    A sensitive radioimmunoassay is described for human immunoglobulins. This solid-phase assay uses commercially available monoclonal antibodies and is specific for different Ig chain types. Levels of less than 20 ng/ml Ig are detectable. The assay is suitable for the analysis of human hybridoma supernatants.

  9. Chimeric Anti-Human Podoplanin Antibody NZ-12 of Lambda Light Chain Exerts Higher Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity Compared with NZ-8 of Kappa Light Chain.

    Science.gov (United States)

    Kaneko, Mika K; Abe, Shinji; Ogasawara, Satoshi; Fujii, Yuki; Yamada, Shinji; Murata, Takeshi; Uchida, Hiroaki; Tahara, Hideaki; Nishioka, Yasuhiko; Kato, Yukinari

    2017-02-01

    Podoplanin (PDPN), a type I transmembrane 36-kDa glycoprotein, is expressed not only in normal cells, such as renal epithelial cells (podocytes), lymphatic endothelial cells, and pulmonary type I alveolar cells, but also in cancer cells, including brain tumors and lung squamous cell carcinomas. Podoplanin activates platelet aggregation by binding to C-type lectin-like receptor-2 (CLEC-2) on platelets, and the podoplanin/CLEC-2 interaction facilitates blood/lymphatic vessel separation. We previously produced neutralizing anti-human podoplanin monoclonal antibody (mAb), clone NZ-1 (rat IgG 2a , lambda), which neutralizes the podoplanin/CLEC-2 interaction and inhibits platelet aggregation and cancer metastasis. Human-rat chimeric antibody, NZ-8, was previously developed using variable regions of NZ-1 and human constant regions of heavy chain (IgG 1 ) and light chain (kappa chain). Although NZ-8 showed high antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against human podoplanin-expressing cancer cells, the binding affinity of NZ-8 was lower than that of NZ-1. Herein, we produced a novel human-rat chimeric antibody, NZ-12, the constant regions of which consist of IgG 1 heavy chain and lambda light chain. Using flow cytometry, we demonstrated that the binding affinity of NZ-12 was much higher than that of NZ-8. Furthermore, ADCC and CDC activities of NZ-12 were significantly increased against glioblastoma cell lines (LN319 and D397) and lung cancer cell line (PC-10). These results suggested that NZ-12 could become a promising therapeutic antibody against podoplanin-expressing brain tumors and lung cancers.

  10. Heavy subgraph pairs for traceability of block-chains

    Directory of Open Access Journals (Sweden)

    Li Binlong

    2014-05-01

    Full Text Available A graph is called traceable if it contains a Hamilton path, i.e., a path containing all its vertices. Let G be a graph on n vertices. We say that an induced subgraph of G is o−1-heavy if it contains two nonadjacent vertices which satisfy an Ore-type degree condition for traceability, i.e., with degree sum at least n−1 in G. A block-chain is a graph whose block graph is a path, i.e., it is either a P1, P2, or a 2-connected graph, or a graph with at least one cut vertex and exactly two end-blocks. Obviously, every traceable graph is a block-chain, but the reverse does not hold. In this paper we characterize all the pairs of connected o−1-heavy graphs that guarantee traceability of block-chains. Our main result is a common extension of earlier work on degree sum conditions, forbidden subgraph conditions and heavy subgraph conditions for traceability

  11. Targeting nanodisks via a single chain variable antibody - Apolipoprotein chimera

    International Nuclear Information System (INIS)

    Iovannisci, David M.; Beckstead, Jennifer A.; Ryan, Robert O.

    2009-01-01

    Nanodisks (ND) are nanometer scale complexes of phospholipid and apolipoprotein that have been shown to function as drug delivery vehicles. ND harboring significant quantities of the antifungal agent, amphotericin B, or the bioactive isoprenoid, all trans retinoic acid, have been generated and characterized. As currently formulated, ND possess limited targeting capability. In this study, we constructed a single chain variable antibody (scFv).apolipoprotein chimera and assessed the ability of this fusion protein to form ND and recognize the antigen to which the scFv is directed. Data obtained revealed that α-vimentin scFv.apolipoprotein A-I is functional in ND formation and antigen recognition, opening the door to the use of such chimeras in targeting drug-enriched ND to specific tissues.

  12. Genetically engineered multivalent single chain antibody constructs for cancer therapy

    International Nuclear Information System (INIS)

    Surinder Batra

    2006-01-01

    increase its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more

  13. Gm typing by immunoglobulin heavy-chain gene RFLP analysis.

    OpenAIRE

    Jazwinska, E C; Dunckley, H; Propert, D N; Gatenby, P A; Serjeantson, S W

    1988-01-01

    This study was undertaken to investigate a means of assigning Gm allotypes to Caucasians by RFLP analysis. A single immunoglobulin heavy-chain gamma-4 cDNA probe (HU gamma 4) was hybridized with genomic DNA digested separately with two restriction enzymes, TaqI and PvuII. Results showed excellent correlation (P less than .001) between serologically defined Gm allotypes G1m(1), G1m(2), G2m(23), and G1m;G3m (3;5,10) and RFLPs identified with the (HU gamma 4) probe. We conclude that it is now po...

  14. Tubulointerstitial nephritis accompanying gamma-heavy chain deposition and gamma-heavy chain restricted plasma cells in the kidney.

    Science.gov (United States)

    Nayer, Ali; Green, Dollie F; Gonzalez-Suarez, Maria L; Sujoy, Victoria; Ikpatt, Offiong F; Thomas, David B

    2014-09-01

    Monoclonal immunoglobulin heavy chain (HC) diseases are rare proliferative disorders of B lymphocytes or plasma cells characterized by the presence of monoclonal α-, µ-, or γ-HC without associated light chains in the blood, urine, or both. We report a 59-year-old woman with a history of Hodgkin disease who developed hypercalcemia, proteinuria, and impaired kidney function. Protein electrophoresis and immunofixation displayed γ-HC without associated light chains in the serum and urine. Pathologic examination demonstrated severe tubulointerstitial nephritis associated with diffuse and strong linear staining of the glomerular and tubular basement membranes as well as Bowman capsules for γ-HC, but not for κ- or λ-light chains. Immunohistochemical examination of the kidney and bone marrow demonstrated numerous CD138+ plasma cells immunoreactive for γ-HC, but not for κ- or λ-light chains. This is the first report of tubulointerstitial nephritis associated with γ-HC deposition and γ-HC restricted plasma cells in the kidney. This report heightens awareness about tubulointerstitial nephritis as a possible manifestation of γ-HC deposition in the kidney.

  15. Physical linkage of a human immunoglobulin heavy chain variable region gene segment to diversity and joining region elements

    International Nuclear Information System (INIS)

    Schroeder, H.W. Jr.; Walter, M.A.; Hofker, M.H.; Ebens, A.; Van Dijk, K.W.; Liao, L.C.; Cox, D.W.; Milner, E.C.B.; Perlmutter, R.M.

    1988-01-01

    Antibody genes are assembled from a series of germ-line gene segments that are juxtaposed during the maturation of B lymphocytes. Although diversification of the adult antibody repertoire results in large part from the combinatorial joining of these gene segments, a restricted set of antibody heavy chain variable (V H ), diversity (D H ), and joining (J H ) region gene segments appears preferentially in the human fetal repertoire. The authors report here that one of these early-expressed V H elements (termed V H 6) is the most 3' V H gene segment, positioned 77 kilobases on the 5' side of the J H locus and immediately adjacent to a set of previously described D H sequences. In addition to providing a physical map linking human V H , D H , and J H elements, these results support the view that the programmed development of the antibody V H repertoire is determined in part by the chromosomal position of these gene segments

  16. Hydrogel Tethering Enhances Interdomain Stabilization of Single-Chain Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yijia [Department; Ford, Nicole R. [Marine; Hecht, Karen A. [Marine; Roesijadi, Guritno [Marine; Department; Squier, Thomas C. [Department

    2017-10-12

    Self-assembly of recombinant proteins within the biosilica of living diatoms represents a means to construct functional materials in a reproducible and scalable manner that enable applications that harness the inherent specificities of proteins to sense and respond to environmental cues. Here we describe the use of a silaffin-derived lysine-rich 39 amino-acid targeting sequence (Sil3T8) to direct a single chain fragment variable (scFv) antibody or an enhanced green fluorescent protein (EGFP) to assemble within the biosilica frustule, resulting in abundances in excess of 200,000 proteins per frustule. The fluorescence of either a derivative of trinitrotoluene (TNT) bound to the scFv or the endogenous fluorescence of EGFP was used to monitor pro-tein conformational dynamics, accessibility to external quenchers, binding affinity, and conformational stability. We find that proteins within isolated frustules undergo isotropic rotational motions with two-fold increases in rotational correlation times, which are indicative of weak macromolecular associations within the biosilica. Solvent accessibilities and high-affinity (pM) binding are comparable to those in solution. In contrast to solution conditions, scFv antibod-ies within the biosilica matrix retain their binding affinity in the presence of chaotropic agents (i.e., 8 M urea). These results argue that dramatic increases in protein conforma-tional stability within the biosilica frustule matrices arise through molecular crowding, acting to retain native protein folds and associated functionality to allow the utility of engineered proteins under a range of harsh environmental conditions associated with environmental sensing and industrial catalytic transformations.

  17. SINGLE CHAIN VARIABLE FRAGMENTS OF ANTIBODIES AGAINST DIPHTHERIA TOXIN B-SUBUNIT ISOLATED FROM PHAGE DISPLAY HUMAN ANTIBODY LIBRARY

    Directory of Open Access Journals (Sweden)

    Oliinyk O. S.

    2014-02-01

    Full Text Available Diphtheria toxin is an exoantigen of Corynebacterium diphtheriae that inhibits protein synthesis and kills sensitive cells. The aim of this study was to obtain human recombinant single-chain variable fragment (scFv antibodies against receptor-binding B subunit of diphtheria toxin. 12 specific clones were selected after three rounds of a phage display naїve (unimmunized human antibody library against recombinant B-subunit. scFv DNA inserts from these 12 clones were digested with MvaI, and 6 unique restriction patterns were found. Single-chain antibodies were expressed in Escherichia coli XL1-blue. The recombinant proteins were characterized by immunoblotting of bacterial extracts and detection with an anti-E-tag antibody. The toxin B-subunit-binding function of the single-chain antibody was shown by ELISA. The affinity constants for different clones were found to be from 106 to 108 М–1. Due to the fact, that these antibody fragments recognized epitopes in the receptor-binding Bsubunit of diphtheria toxin, further studies are interesting to evaluate their toxin neutralization properties and potential for therapeutic applications. Obtained scFv-antibodies can also be used for detection and investigation of biological properties of diphtheria toxin.

  18. Camelid-derived heavy-chain nanobody against Clostridium botulinum neurotoxin E in Pichia pastoris.

    Science.gov (United States)

    Baghban, Roghayyeh; Gargari, Seyed Latif Mousavi; Rajabibazl, Masoumeh; Nazarian, Shahram; Bakherad, Hamid

    2016-01-01

    Botulinum neurotoxins (BoNTs) result in severe and often fatal disease, botulism. Common remedial measures such as equine antitoxin and human botulism immunoglobulin in turn are problematic and time-consuming. Therefore, diagnosis and therapy of BoNTs are vital. The variable domain of heavy-chain antibodies (VHH) has unique features, such as the ability to identify and bind specifically to target epitopes and ease of production in bacteria and yeast. The Pichia pastoris is suitable for expression of recombinant antibody fragments. Disulfide bond formation and correct folds of protein with a high yield are some of the advantages of this eukaryotic host. In this study, we have expressed and purified the camelid VHH against BoNT/E in P. pastoris. The final yield of P. pastoris-expressed antibody was estimated to be 16 mg/l, which is higher than that expressed by Escherichia coli. The nanobody expressed in P. pastoris neutralized 4LD50 of the BoNT/E upon i.p. injection in 25% of mice. The nanobody expressed in E. coli extended the mice's survival to 1.5-fold compared to the control. This experiment indicated that the quality of expressed protein in the yeast is superior to that of the bacterial expression. Favorable protein folding by P. pastoris seems to play a role in its better toxin-binding property. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  19. Diversity analysis of the immunoglobulin M heavy chain gene in Nile ...

    African Journals Online (AJOL)

    nu tom

    2015-07-22

    Jul 22, 2015 ... related industries and supply chains, such as hatcheries, feed manufacturers ... system has a high risk of disease outbreaks. The bulk of ...... immunoglobulin heavy-chain locus in zebrafish: identification and expression of a ...

  20. Enhanced protein electrophoresis technique for separating human skeletal muscle myosin heavy chain isoforms

    Science.gov (United States)

    Bamman, M. M.; Clarke, M. S.; Talmadge, R. J.; Feeback, D. L.

    1999-01-01

    Talmadge and Roy (J. Appl. Physiol. 1993, 75, 2337-2340) previously established a sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) protocol for separating all four rat skeletal muscle myosin heavy chain (MHC) isoforms (MHC I, IIa, IIx, IIb); however, when applied to human muscle, the type II MHC isoforms (Ila, IIx) are not clearly distinguished. In this brief paper we describe a modification of the SDS-PAGE protocol which yields distinct and consistent separation of all three adult human MHC isoforms (MHC I, IIa, IIx) in a minigel system. MHC specificity of each band was confirmed by Western blot using three monoclonal IgG antibodies (mAbs) immunoreactive against MHCI (mAb MHCs, Novacastra Laboratories), MHCI+IIa (mAb BF-35), and MHCIIa+IIx (mAb SC-71). Results provide a valuable SDS-PAGE minigel technique for separating MHC isoforms in human muscle without the difficult task of casting gradient gels.

  1. Comparing domain interactions within antibody Fabs with kappa and lambda light chains.

    Science.gov (United States)

    Toughiri, Raheleh; Wu, Xiufeng; Ruiz, Diana; Huang, Flora; Crissman, John W; Dickey, Mark; Froning, Karen; Conner, Elaine M; Cujec, Thomas P; Demarest, Stephen J

    2016-10-01

    IgG antibodies are multi-domain proteins with complex inter-domain interactions. Human IgG heavy chains (HCs) associate with light chains (LCs) of the κ or λ isotype to form mature antibodies capable of binding antigen. The HC/LC interaction involves 4 domains: VH and CH1 from the HC and VL and CL from the LC. Human Fabs with κ LCs have been well characterized for their unfolding behaviors and demonstrate a significant level of cooperativity and stabilization when all 4 domains are intact. Very little is known regarding the thermodynamic properties of human Fabs with λ LCs. Here, we dissect the domain contributions to Fab stability for both κ and λ LC-containing Fabs. We find the cooperativity of unfolding between the constant domains, CH1/Cλ, and variable domains, VH/Vλ, within λ LC-containing Fabs is significantly weaker than that of κ LC-containing Fabs. The data suggests there may not be an evolutionary necessity for strong variable/constant domain cooperativity within λ LC-containing Fabs. After investigating the biophysical properties of Fabs with mismatched variable and constant domain subunits (e.g., VH/Vκ paired with CH1/Cλ or T cell receptor Cα/Cβ), the major role of the constant domains for both κ- and λ-containing Fabs may be to reduce the hydrophobic exposure at the VH/VL interface. Even though Fabs with these non-native pairings were thermodynamically less stable, they secreted well from mammalian cells as well behaved monodisperse proteins, which was in contrast to what was observed with the VH/Vκ and VH/Vλ scFvs that secreted as a mixture of monomer and aggregates.

  2. Uses of monoclonial antibody 8H9

    Science.gov (United States)

    Cheung, Nai-Kong V.

    2015-06-23

    This invention provides an antibody that binds the same antigen as that of monoclonal antibody 8H9, wherein the heavy chain CDR (Complementary Determining Region)1 comprises NYDIN, heavy chain CDR2 comprises WIFPGDGSTQY, heavy chain CDR3 comprises QTTATWFAY, and the light chain CDR1 comprises RASQSISDYLH, light chain CDR2 comprises YASQSIS, and light chain CDR3 comprises QNGHSFPLT. In another embodiment, there is provided a polypeptide that binds the same antigen as that of monoclonal antibody 8H9, wherein the polypeptide comprises NYDIN, WIFPGDGSTQY, QTTATWFAY, RASQSISDYLH, YASQSIS, and QNGHSFPLT.

  3. Neutralization of botulinum neurotoxin by a human monoclonal antibody specific for the catalytic light chain.

    Directory of Open Access Journals (Sweden)

    Sharad P Adekar

    2008-08-01

    Full Text Available Botulinum neurotoxins (BoNT are a family of category A select bioterror agents and the most potent biological toxins known. Cloned antibody therapeutics hold considerable promise as BoNT therapeutics, but the therapeutic utility of antibodies that bind the BoNT light chain domain (LC, a metalloprotease that functions in the cytosol of cholinergic neurons, has not been thoroughly explored.We used an optimized hybridoma method to clone a fully human antibody specific for the LC of serotype A BoNT (BoNT/A. The 4LCA antibody demonstrated potent in vivo neutralization when administered alone and collaborated with an antibody specific for the HC. In Neuro-2a neuroblastoma cells, the 4LCA antibody prevented the cleavage of the BoNT/A proteolytic target, SNAP-25. Unlike an antibody specific for the HC, the 4LCA antibody did not block entry of BoNT/A into cultured cells. Instead, it was taken up into synaptic vesicles along with BoNT/A. The 4LCA antibody also directly inhibited BoNT/A catalytic activity in vitro.An antibody specific for the BoNT/A LC can potently inhibit BoNT/A in vivo and in vitro, using mechanisms not previously associated with BoNT-neutralizing antibodies. Antibodies specific for BoNT LC may be valuable components of an antibody antidote for BoNT exposure.

  4. A binary plasmid system for shuffling combinatorial antibody libraries.

    OpenAIRE

    Collet, T A; Roben, P; O'Kennedy, R; Barbas, C F; Burton, D R; Lerner, R A

    1992-01-01

    We have used a binary system of replicon-compatible plasmids to test the potential for promiscuous recombination of heavy and light chains within sets of human Fab fragments isolated from combinatorial antibody libraries. Antibody molecules showed a surprising amount of promiscuity in that a particular heavy chain could recombine with multiple light chains with retention of binding to a protein antigen. The degree to which a given heavy chain productively paired with any light chain to bind a...

  5. Removal of a C-terminal serine residue proximal to the inter-chain disulfide bond of a human IgG1 lambda light chain mediates enhanced antibody stability and antibody dependent cell-mediated cytotoxicity

    Science.gov (United States)

    Shen, Yang; Zeng, Lin; Zhu, Aiping; Blanc, Tim; Patel, Dipa; Pennello, Anthony; Bari, Amtul; Ng, Stanley; Persaud, Kris; Kang, Yun (Kenneth); Balderes, Paul; Surguladze, David; Hindi, Sagit; Zhou, Qinwei; Ludwig, Dale L.; Snavely, Marshall

    2013-01-01

    Optimization of biophysical properties is a critical success factor for the developability of monoclonal antibodies with potential therapeutic applications. The inter-domain disulfide bond between light chain (Lc) and heavy chain (Hc) in human IgG1 lends structural support for antibody scaffold stability, optimal antigen binding, and normal Fc function. Recently, human IgG1λ has been suggested to exhibit significantly greater susceptibility to reduction of the inter Lc-Hc disulfide bond relative to the same disulfide bond in human IgG1κ. To understand the molecular basis for this observed difference in stability, the sequence and structure of human IgG1λ and human IgG1κ were compared. Based on this Lc comparison, three single mutations were made in the λ Lc proximal to the cysteine residue, which forms a disulfide bond with the Hc. We determined that deletion of S214 (dS) improved resistance of the association between Lc and Hc to thermal stress. In addition, deletion of this terminal serine from the Lc of IgG1λ provided further benefit, including an increase in stability at elevated pH, increased yield from transient transfection, and improved in vitro antibody dependent cell-mediated cytotoxicity (ADCC). These observations support the conclusion that the presence of the terminal serine of the λ Lc creates a weaker inter-chain disulfide bond between the Lc and Hc, leading to slightly reduced stability and a potential compromise in IgG1λ function. Our data from a human IgG1λ provide a basis for further investigation of the effects of deleting terminal serine from λLc on the stability and function of other human IgG1λ antibodies. PMID:23567210

  6. A new approach for generating bispecific antibodies based on a common light chain format and the stable architecture of human immunoglobulin G1.

    Science.gov (United States)

    De Nardis, Camilla; Hendriks, Linda J A; Poirier, Emilie; Arvinte, Tudor; Gros, Piet; Bakker, Alexander B H; de Kruif, John

    2017-09-01

    Bispecific antibodies combine two different antigen-binding sites in a single molecule, enabling more specific targeting, novel mechanisms of action, and higher clinical efficacies. Although they have the potential to outperform conventional monoclonal antibodies, many bispecific antibodies have issues regarding production, stability, and pharmacokinetic properties. Here, we describe a new approach for generating bispecific antibodies using a common light chain format and exploiting the stable architecture of human immunoglobulin G 1 We used iterative experimental validation and computational modeling to identify multiple Fc variant pairs that drive efficient heterodimerization of the antibody heavy chains. Accelerated stability studies enabled selection of one Fc variant pair dubbed "DEKK" consisting of substitutions L351D and L368E in one heavy chain combined with L351K and T366K in the other. Solving the crystal structure of the DEKK Fc region at a resolution of 2.3 Å enabled detailed analysis of the interactions inducing CH3 interface heterodimerization. Local shifts in the IgG backbone accommodate the introduction of lysine side chains that form stabilizing salt-bridge interactions with substituted and native residues in the opposite chain. Overall, the CH3 domain adapted to these shifts at the interface, yielding a stable Fc conformation very similar to that in wild-type IgG. Using the DEKK format, we generated the bispecific antibody MCLA-128, targeting human EGF receptors 2 and 3. MCLA-128 could be readily produced and purified at industrial scale with a standard mammalian cell culture platform and a routine purification protocol. Long-term accelerated stability assays confirmed that MCLA-128 is highly stable and has excellent biophysical characteristics. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Characterization of the interaction between the heavy and light chains of bovine factor Va.

    Science.gov (United States)

    Walker, F J

    1992-10-05

    Bovine factor Va has been previously been shown to consist of heavy (M(r) = 94,000) and light chains (M(r) = 81,000), that interact in a manner dependent upon the presence of either calcium or manganese ions. In an attempt to understand the mechanism of subunit interaction we have studied the effects of temperature and ions on factor Va stability. The rates of formation of factor Va from isolated chains and dissociation were temperature-dependent with an energy of activation of 6.2 and 1.3 kcal mol-1, respectively. The yield of factor Va from isolated chains was inversely related to the amount of time the chains were incubated at 4 degrees C. Incubation of individual chains revealed that the heavy chain is cold-labile, an effect that is reversible. Manganese ion was observed to prevent the conversion to the inactive form. High salt tends to stabilize the two-chain structure of factor Va, but is inhibitory to its formation from isolated chains. High concentrations of either manganese or calcium ions also inhibited reconstitution of activity. The light chain, in particular, was sensitive to the presence of manganese or calcium ion. Heavy chain that had been cleaved by activated protein C had a weakened interaction with the light chain, and the resulting complex had no procoagulant activity. Cooling of the heavy chain to 4 degrees C enhanced its intrinsic fluorescence. Manganese ion prevented some of this enhancement. The heavy chain fluorescence returned to the room temperature value with a half-life of approximately 10 min. In the presence of manganese ion relaxation was accelerated. The intrinsic fluorescence of activated protein C-cleaved heavy chain was not increased when the temperature was decreased. These data suggest that the heavy chain can exist in two forms. Elevated temperature converts it to a form that can bind ions and have a productive interaction with the light chain. However, conditions that prevent the heavy chain from combining with the light

  8. A Trypanosoma brucei kinesin heavy chain promotes parasite growth by triggering host arginase activity.

    Directory of Open Access Journals (Sweden)

    Géraldine De Muylder

    2013-10-01

    Full Text Available In order to promote infection, the blood-borne parasite Trypanosoma brucei releases factors that upregulate arginase expression and activity in myeloid cells.By screening a cDNA library of T. brucei with an antibody neutralizing the arginase-inducing activity of parasite released factors, we identified a Kinesin Heavy Chain isoform, termed TbKHC1, as responsible for this effect. Following interaction with mouse myeloid cells, natural or recombinant TbKHC1 triggered SIGN-R1 receptor-dependent induction of IL-10 production, resulting in arginase-1 activation concomitant with reduction of nitric oxide (NO synthase activity. This TbKHC1 activity was IL-4Rα-independent and did not mirror M2 activation of myeloid cells. As compared to wild-type T. brucei, infection by TbKHC1 KO parasites was characterized by strongly reduced parasitaemia and prolonged host survival time. By treating infected mice with ornithine or with NO synthase inhibitor, we observed that during the first wave of parasitaemia the parasite growth-promoting effect of TbKHC1-mediated arginase activation resulted more from increased polyamine production than from reduction of NO synthesis. In late stage infection, TbKHC1-mediated reduction of NO synthesis appeared to contribute to liver damage linked to shortening of host survival time.A kinesin heavy chain released by T. brucei induces IL-10 and arginase-1 through SIGN-R1 signaling in myeloid cells, which promotes early trypanosome growth and favors parasite settlement in the host. Moreover, in the late stage of infection, the inhibition of NO synthesis by TbKHC1 contributes to liver pathogenicity.

  9. Generation of human antibody fragments against Streptococcus mutans using a phage display chain shuffling approach

    Directory of Open Access Journals (Sweden)

    Barth Stefan

    2005-01-01

    Full Text Available Abstract Background Common oral diseases and dental caries can be prevented effectively by passive immunization. In humans, passive immunotherapy may require the use of humanized or human antibodies to prevent adverse immune responses against murine epitopes. Therefore we generated human single chain and diabody antibody derivatives based on the binding characteristics of the murine monoclonal antibody Guy's 13. The murine form of this antibody has been used successfully to prevent Streptococcus mutans colonization and the development of dental caries in non-human primates, and to prevent bacterial colonization in human clinical trials. Results The antibody derivatives were generated using a chain-shuffling approach based on human antibody variable gene phage-display libraries. Like the parent antibody, these derivatives bound specifically to SAI/II, the surface adhesin of the oral pathogen S. mutans. Conclusions Humanization of murine antibodies can be easily achieved using phage display libraries. The human antibody fragments bind the antigen as well as the causative agent of dental caries. In addition the human diabody derivative is capable of aggregating S. mutans in vitro, making it a useful candidate passive immunotherapeutic agent for oral diseases.

  10. Characterization of human cardiac myosin heavy chain genes

    International Nuclear Information System (INIS)

    Yamauchi-Takihara, K.; Sole, M.J.; Liew, J.; Ing, D.; Liew, C.C.

    1989-01-01

    The authors have isolated and analyzed the structure of the genes coding for the α and β forms of the human cardiac myosin heavy chain (MYHC). Detailed analysis of four overlapping MYHC genomic clones shows that the α-MYHC and β-MYHC genes constitute a total length of 51 kilobases and are tandemly linked. The β-MYHC-encoding gene, predominantly expressed in the normal human ventricle and also in slow-twitch skeletal muscle, is located 4.5 kilobases upstream of the α-MYHC-encoding gene, which is predominantly expressed in normal human atrium. The authors have determined the nucleotide sequences of the β form of the MYHC gene, which is 100% homologous to the cardiac MYHC cDNA clone (pHMC3). It is unlikely that the divergence of a few nucleotide sequences from the cardiac β-MYHC cDNA clone (pHMC3) reported in a MYHC cDNA clone (PSMHCZ) from skeletal muscle is due to a splicing mechanism. This finding suggests that the same β form of the cardiac MYHC gene is expressed in both ventricular and slow-twitch skeletal muscle. The promoter regions of both α- and β-MYHC genes, as well as the first four coding regions in the respective genes, have also been sequenced. The sequences in the 5'-flanking region of the α- and β-MYHC-encoding genes diverge extensively from one another, suggesting that expression of the α- and β-MYHC genes is independently regulated

  11. A binary plasmid system for shuffling combinatorial antibody libraries.

    Science.gov (United States)

    Collet, T A; Roben, P; O'Kennedy, R; Barbas, C F; Burton, D R; Lerner, R A

    1992-11-01

    We have used a binary system of replicon-compatible plasmids to test the potential for promiscuous recombination of heavy and light chains within sets of human Fab fragments isolated from combinatorial antibody libraries. Antibody molecules showed a surprising amount of promiscuity in that a particular heavy chain could recombine with multiple light chains with retention of binding to a protein antigen. The degree to which a given heavy chain productively paired with any light chain to bind antigen varied from 43% to 100% and depended strongly on the heavy-chain sequence. Such productive crosses resulted in a set of Fab fragments of similar apparent binding constants, which seemed to differ mainly in the amount of active Fab fragment produced in the bacterial cell. The dominance of the heavy chain in the antibody-antigen interaction was further explored in a set of directed crosses, in which heavy and light chains derived from antigen-specific clones were crossed with nonrelated heavy and light chains. In these crosses, an Fab fragment retained antigen binding only if it contained a heavy chain from an antigen-specific clone. In no case did the light chain confer detectable affinity when paired with indifferent heavy chains. The surprising promiscuity of heavy chains has ramifications for the evaluation of the diversity of combinatorial libraries made against protein antigens and should allow the combination of one such promiscuous heavy chain with an engineered light chain to form an Fab fragment carrying synthetic cofactors to assist in antibody catalysis.

  12. Porcine circovirus type 2 ORF4 protein binds heavy chain ferritin

    Indian Academy of Sciences (India)

    Porcine circovirus type 2 ORF4 protein binds heavy chain ferritin. Qizhuang Lv Kangkang Guo Tao Wang ... Keywords. Cellular protein; FHC; ORF4 protein; porcine circovirus type 2 (PCV2); yeast two-hybrid ... Journal of Biosciences | News ...

  13. Serial cerebrospinal fluid neurofilament heavy chain levels in severe Guillain-Barre syndrome

    NARCIS (Netherlands)

    Dujmovic, I.; Lunn, M.P.; Reilly, M.M.; Petzold, A.

    2013-01-01

    Introduction: Proximal axonotmesis results in the release of neurofilament (Nf) proteins into the cerebrospinal fluid (CSF) in patients with Guillain-Barré syndrome (GBS). High CSF levels of the phosphorylated form of Nf-heavy chain (NfH

  14. The motion planning problem and exponential stabilization of a heavy chain. Part II

    OpenAIRE

    Piotr Grabowski

    2008-01-01

    This is the second part of paper [P. Grabowski, The motion planning problem and exponential stabilization of a heavy chain. Part I, to appear in International Journal of Control], where a model of a heavy chain system with a punctual load (tip mass) in the form of a system of partial differential equations was interpreted as an abstract semigroup system and then analysed on a Hilbert state space. In particular, in [P. Grabowski, The motion planning problem and exponential stabilization of a h...

  15. Tracing heavy metals in 'swine manure - maggot - chicken' production chain.

    Science.gov (United States)

    Wang, Wanqiang; Zhang, Wenjuan; Wang, Xiaoping; Lei, Chaoliang; Tang, Rui; Zhang, Feng; Yang, Qizhi; Zhu, Fen

    2017-08-21

    With the development of large-scale livestock farming, manure pollution has drawn much attention. Conversion by insects is a rapid and cost-effective new method for manure management. Swine manure conversion with maggots (Musca domestica larvae) has developed, and the harvested maggots are often used as animal feed. However, the flow of heavy metals from manure to downstream processes cannot be ignored, and therefore, heavy metal content was measured in untreated raw manure, maggot-treated manure, harvested maggots and maggot-eating chickens (chest muscle and liver) to evaluate potential heavy metal risks. The levels of zinc, copper, chromium, selenium, cadmium and lead had significant differences between untreated raw manure and maggot-treated manure. The concentrations of all detected heavy metals, except for cadmium and selenium, in maggots met the limits established by the feed or feed additive standards of many countries. The bioaccumulation factor (BAF) of heavy metals decreased with the increase of the maggot instar, indicating that heavy metals were discharged from the bodies of maggots with the growth of maggots. Also, the contents of overall heavy metals in chickens fed harvested maggots met the standards for food. In conclusion, regarding heavy metals, it is eco-safe to use maggots in manure management.

  16. Development of single chain variable fragment (scFv) antibodies against Xylella fastidiosa subsp. pauca by phage display.

    Science.gov (United States)

    Yuan, Qing; Jordan, Ramon; Brlansky, Ronald H; Istomina, Olga; Hartung, John

    2015-10-01

    Xylella fastidiosa is a member of the gamma proteobacteria. It is fastidious, insect-vectored and xylem-limited and causes a variety of diseases, some severe, on a wide range of economically important perennial crops, including grape and citrus. Antibody based detection assays are commercially available for X. fastidiosa, and are effective at the species, but not at the subspecies level. We have made a library of scFv antibody fragments directed against X. fastidiosa subsp. pauca strain 9a5c (citrus) by using phage display technology. Antibody gene repertoires were PCR-amplified using 23 primers for the heavy chain variable region (V(H)) and 21 primers for the light chain variable region (V(L)). The V(H) and V(L) were joined by overlap extension PCR, and then the genes of the scFv library were ligated into the phage vector pKM19. The library contained 1.2×10(7) independent clones with full-length scFv inserts. In each of 3cycles of affinity-selection with 9a5c, about 1.0×10(12) phage were used for panning with 4.1×10(6), 7.1×10(6), 2.1×10(7) phage recovered after the first, second and third cycles, respectively. Sixty-six percent of clones from the final library bound X. fastidiosa 9a5c in an ELISA. Some of these scFv antibodies recognized strain 9a5c and did not recognize X. fastidiosa strains that cause Pierce's disease of grapevine. Published by Elsevier B.V.

  17. Escherichia coli surface display of single-chain antibody VRC01 against HIV-1 infection

    International Nuclear Information System (INIS)

    Wang, Lin-Xu; Mellon, Michael; Bowder, Dane; Quinn, Meghan; Shea, Danielle; Wood, Charles; Xiang, Shi-Hua

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) transmission and infection occur mainly via the mucosal surfaces. The commensal bacteria residing in these surfaces can potentially be employed as a vehicle for delivering inhibitors to prevent HIV-1 infection. In this study, we have employed a bacteria-based strategy to display a broadly neutralizing antibody VRC01, which could potentially be used to prevent HIV-1 infection. The VRC01 antibody mimics CD4-binding to gp120 and has broadly neutralization activities against HIV-1. We have designed a construct that can express the fusion peptide of the scFv-VRC01 antibody together with the autotransporter β-barrel domain of IgAP gene from Neisseria gonorrhoeae, which enabled surface display of the antibody molecule. Our results indicate that the scFv-VRC01 antibody molecule was displayed on the surface of the bacteria as demonstrated by flow cytometry and immunofluorescence microscopy. The engineered bacteria can capture HIV-1 particles via surface-binding and inhibit HIV-1 infection in cell culture. - Highlights: • Designed single-chain VRC01 antibody was demonstrated to bind HIV-1 envelope gp120. • Single-chain VRC01 antibody was successfully displayed on the surface of E. coli. • Engineered bacteria can absorb HIV-1 particles and prevent HIV-1 infection in cell culture

  18. A high affinity monoclonal antibody recognizing the light chain of human coagulating factor VII.

    Science.gov (United States)

    Sarial, Sheila; Asadi, Farzad; Jeddi-Tehrani, Mahmood; Hadavi, Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Taghizadeh-Jahed, Masoud; Shokri, Fazel; Rabbani, Hodjattallah

    2012-12-01

    Factor VII (FVII) is a serine protease-coagulating element responsible for the initiation of an extrinsic pathway of clot formation. Here we generated and characterized a high affinity monoclonal antibody that specifically recognizes human FVII. Recombinant human FVII (rh-FVII) was used for the production of a monoclonal antibody using BALB/c mice. The specificity of the antibody was determined by Western blot using plasma samples from human, mouse, sheep, goat, bovine, rabbit, and rat. Furthermore, the antibody was used to detect transiently expressed rh-FVII in BHK21 cell line using Western blot and sandwich ELISA. A mouse IgG1 (kappa chain) monoclonal antibody clone 1F1-B11 was produced against rh-FVII. The affinity constant (K(aff)) of the antibody was calculated to be 6.4×10(10) M(-1). The antibody could specifically recognize an epitope on the light chain of hFVII, with no reactivity with factor VII from several other animals. In addition, transiently expressed rh-FVII in BHK21 cells was recognized by 1F1-B11. The high affinity as well as the specificity of 1F1-B11 for hFVII will facilitate the affinity purification of hFVII and also production of FVII deficient plasma and minimizes the risk of bovine FVII contamination when fetal bovine serum-supplemented media are used for production and subsequent purification of rh-FVII.

  19. [Construction of a phage antibody library and screening of anti-epidermal growth factor receptor variant III single chain antibody].

    Science.gov (United States)

    Han, Dong-gang; Duan, Xiao-yi; Guo, You-min; Zhou, Qi; Wang, Quan-ying; Yang, Guang-xiao

    2010-01-01

    To obtain specific anti-epidermal growth factor receptor variant III (EGFRvIII) single chain antibody (ScFv) by phage antibody library display system. The total RNA was extracted from the spleen B cells of BALB/c mice immunized with pep-3-OVA protein, and the first-strand cDNA was synthesized by reverse transcription. Antibody VH and VL gene fragments were amplified and joined to a ScFv gene with the linker. The ScFv gene was ligated into the phagemid vector pCANTAB5E, which was transformed into competent E. coli TG1. The transformed cells were then infected with M13KO7 helper phage to yield the recombinant phage to construct the phage ScFv library. Pep-3-BSA protein was used to screen the phage antibody library and ELISA carried out to characterize the activity of the antibody. The VH and VL gene fragments of the antibody were about 350 bp and 320 bp in length as analyzed by agarose gel electrophoresis. The ScFv gene was 780 bp, consistent with the expected length. The recombinant phagemid with ScFv gene insert was rescued, and an immune phage ScFv library with the content of 5.0x10(6) was constructed. The recombinant ScFv phage had a titer of 3.0x10(4) cfu/ml, and the fourth phage harvest yielded 56 times as much as that of the first one. SDS-PAGE demonstrated a molecular mass of the soluble ScFv of about 28 kD. ELISA results indicated good specificity of the ScFv to bind EGFRvIII. An immune phage ScFv library is successfully constructed, and the ScFv antibody fragment is capable of specific binding to EGFRvIII.

  20. Myosin heavy chain composition of tiger (Panthera tigris) and cheetah (Acinonyx jubatus) hindlimb muscles.

    Science.gov (United States)

    Hyatt, Jon-Philippe K; Roy, Roland R; Rugg, Stuart; Talmadge, Robert J

    2010-01-01

    Felids have a wide range of locomotor activity patterns and maximal running speeds, including the very fast cheetah (Acinonyx jubatas), the roaming tiger (Panthera tigris), and the relatively sedentary domestic cat (Felis catus). As previous studies have suggested a relationship between the amount and type of activity and the myosin heavy chain (MHC) isoform composition of a muscle, we assessed the MHC isoform composition of selected hindlimb muscles from these three felid species with differing activity regimens. Using gel electrophoresis, western blotting, histochemistry, and immunohistochemistry with MHC isoform-specific antibodies, we compared the MHC composition in the tibialis anterior, medial gastrocnemius (MG), plantaris (Plt), and soleus muscles of the tiger, cheetah, and domestic cat. The soleus muscle was absent in the cheetah. At least one slow (type I) and three fast (types IIa, IIx, and IIb) MHC isoforms were present in the muscles of each felid. The tiger had a high combined percentage of the characteristically slower isoforms (MHCs I and IIa) in the MG (62%) and the Plt (86%), whereas these percentages were relatively low in the MG (44%) and Plt (55%) of the cheetah. In general, the MHC isoform characteristics of the hindlimb muscles matched the daily activity patterns of these felids: the tiger has daily demands for covering long distances, whereas the cheetah has requirements for speed and power. (c) 2009 Wiley-Liss, Inc.

  1. Suppression of Aggrus/podoplanin-induced platelet aggregation and pulmonary metastasis by a single-chain antibody variable region fragment

    International Nuclear Information System (INIS)

    Miyata, Kenichi; Takagi, Satoshi; Sato, Shigeo; Morioka, Hiroshi; Shiba, Kiyotaka; Minamisawa, Tamiko; Takami, Miho; Fujita, Naoya

    2014-01-01

    Almost all highly metastatic tumor cells possess high platelet aggregating abilities, thereby form large tumor cell-platelet aggregates in the microvasculature. Embolization of tumor cells in the microvasculature is considered to be the first step in metastasis to distant organs. We previously identified the platelet aggregation-inducing factor expressed on the surfaces of highly metastatic tumor cells and named as Aggrus. Aggrus was observed to be identical to the marker protein podoplanin (alternative names, T1α, OTS-8, and others). Aggrus is frequently overexpressed in several types of tumors and enhances platelet aggregation by interacting with the platelet receptor C-type lectin-like receptor 2 (CLEC-2). Here, we generated a novel single-chain antibody variable region fragment (scFv) by linking the variable regions of heavy and light chains of the neutralizing anti-human Aggrus monoclonal antibody MS-1 with a flexible peptide linker. Unfortunately, the generated KM10 scFv failed to suppress Aggrus-induced platelet aggregation in vitro. Therefore, we performed phage display screening and finally obtained a high-affinity scFv, K-11. K-11 scFv was able to suppress Aggrus-induced platelet aggregation in vitro. Moreover, K-11 scFv prevented the formation of pulmonary metastasis in vivo. These results suggest that K-11 scFv may be useful as metastasis inhibitory scFv and is expected to aid in the development of preclinical and clinical examinations of Aggrus-targeted cancer therapies

  2. Acquired cutis laxa associated with light and heavy chain deposition disease

    Directory of Open Access Journals (Sweden)

    Reena A Majithia

    2018-01-01

    Full Text Available Acquired cutis laxa (ACL is a rare connective tissue disorder characterized by pendulous and coarsely wrinkled skin. There have been few cases of its association to monoclonal immunoglobulin deposition disease (MIDD, which constitutes the light chain (LCDD, heavy chain (HCDD, and light and heavy chain (LHCDD deposition disease. MIDD predominantly involves the kidney. Skin is the next common organ to be affected by HCDD, which presents as ACL. We report the case of a 40-year-old male who presented with ACL associated with LHCDD. The clinical features of ACL in the present case appeared prior to the development of clinical features related to LHCDD.

  3. Excessive amounts of mu heavy chain block B-cell development.

    Science.gov (United States)

    Zhu, Lingqiao; Chang, Cheong-Hee; Dunnick, Wesley

    2011-09-01

    Antigen-independent B-cell development occurs in several stages that depend on the expression of Ig heavy and light chain. We identified a line of mice that lacked mature B cells in the spleen. This mouse line carried approximately 11 copies of a transgene of the murine heavy chain constant region locus, and B-lineage cells expressed excessive amounts of the intracellular μ heavy chain. B-cell development failed in the bone marrow at the pro/pre B-cell transition, and examination of other lines with various copy numbers of the same transgene suggested that deficiencies in B-cell development increased with increased transgene copy number. Expression of a transgenic (Tg) light chain along with the Tg μ heavy chain led to minimal rescue of B-cell development in the bone marrow and B cells in the spleen. There are several potential mechanisms for the death of pro/pre B cells as a consequence of excess heavy chain expression.

  4. A sensitive chain specific radioimmunoassay for human immunoglobulins using monoclonal antibodies

    International Nuclear Information System (INIS)

    Sikora, K.; Alderson, T.St.J.; Ellis, J.

    1983-01-01

    A sensitive radioimmunoassay is described for human immunoglobulins. This solid-phase assay uses commercially available monoclonal antibodies and is specific for different Ig chain types. Levels of less than 20 ng/ml Ig are detectable. The assay is suitable for the analysis of human hybridoma supernatants. (Auth.)

  5. Optimization of the crystallizability of a single-chain antibody fragment

    Czech Academy of Sciences Publication Activity Database

    Škerlová, Jana; Král, Vlastimil; Fábry, Milan; Sedláček, Juraj; Veverka, Václav; Řezáčová, Pavlína

    2014-01-01

    Roč. 70, č. 12 (2014), s. 1701-1706 ISSN 1744-3091 R&D Projects: GA MŠk(CZ) LK11205 Institutional support: RVO:61388963 ; RVO:68378050 Keywords : single-chain antibody fragment * Thermofluor assay * differential scanning fluorimetry * crystallizability optimization * oligomerization * crystallization Subject RIV: CE - Biochemistry Impact factor: 0.527, year: 2014

  6. Heavy subgraph pairs for traceability of block-chains

    NARCIS (Netherlands)

    Li, Binlong; Li, Binlong; Broersma, Haitze J.; Zhang, Shenggui

    2014-01-01

    A graph is called traceable if it contains a Hamilton path, i.e., a path containing all its vertices. Let G be a graph on n vertices. We say that an induced subgraph of G is o-1-heavy if it contains two nonadjacent vertices which satisfy an Ore-type degree condition for traceability, i.e., with

  7. A plasmid containing the human metallothionein II gene can function as an antibody-assisted electrophoretic biosensor for heavy metals.

    Science.gov (United States)

    Wooten, Dennis C; Starr, Clarise R; Lyon, Wanda J

    2016-01-01

    Different forms of heavy metals affect biochemical systems in characteristic ways that cannot be detected with typical metal analysis methods like atomic absorption spectrometry. Further, using living systems to analyze interaction of heavy metals with biochemical systems can be laborious and unreliable. To generate a reliable easy-to-use biologically-based biosensor system, the entire human metallothionein-II (MT-II) gene was incorporated into a plasmid (pUC57-MT) easily replicated in Escherichia coli. In this system, a commercial polyclonal antibody raised against human metal-responsive transcription factor-1 protein (MTF-1 protein) could modify the electrophoretic migration patterns (i.e. cause specific decreases in agarose gel electrophoretic mobility) of the plasmid in the presence or absence of heavy metals other than zinc (Zn). In the study here, heavy metals, MTF-1 protein, and polyclonal anti-MTF-1 antibody were used to assess pUC57-MT plasmid antibody-assisted electrophoretic mobility. Anti-MTF-1 antibody bound both MTF-1 protein and pUC57-MT plasmid in a non-competitive fashion such that it could be used to differentiate specific heavy metal binding. The results showed that antibody-inhibited plasmid migration was heavy metal level-dependent. Zinc caused a unique mobility shift pattern opposite to that of other metals tested, i.e. Zn blocked the antibody ability to inhibit plasmid migration, despite a greatly increased affinity for DNA by the antibody when Zn was present. The Zn effect was reversed/modified by adding MTF-1 protein. Additionally, antibody inhibition of plasmid mobility was resistant to heat pre-treatment and trypsinization, indicating absence of residual DNA extraction-resistant bacterial DNA binding proteins. DNA binding by anti-DNA antibodies may be commonly enhanced by xenobiotic heavy metals and elevated levels of Zn, thus making them potentially effective tools for assessment of heavy metal bioavailability in aqueous solutions and

  8. A novel variable antibody fragment dimerized by leucine zippers with enhanced neutralizing potency against rabies virus G protein compared to its corresponding single-chain variable antibody fragment.

    Science.gov (United States)

    Li, Zhuang; Cheng, Yue; Xi, Hualong; Gu, Tiejun; Yuan, Ruosen; Chen, Xiaoxu; Jiang, Chunlai; Kong, Wei; Wu, Yongge

    2015-12-01

    Fatal rabies can be prevented effectively by post-exposure prophylactic (PEP) with rabies immunoglobulin (RIG). Single-chain variable fragments (scFv), which are composed of a variable heavy chain (VH) and a variable light chain (VL) connected by a peptide linker, can potentially be used to replace RIG. However, in our previous study, a scFv (scFV57S) specific for the rabies virus (RV) G protein showed a lower neutralizing potency than that of its parent IgG due to lower stability and altered peptide assembly pattern. In monoclonal antibodies, the VH and VL interact non-covalently, while in scFvs the VH is connected covalently with the VL by the artificial linker. In this study, we constructed and expressed two peptides 57VL-JUN-HIS and 57VH-FOS-HA in Escherichia coli. The well-known Fos and Jun leucine zippers were utilized to dimerize VH and VL similarly to the IgG counterpart. The two peptides assembled to form zipFv57S in vitro. Due to the greater similarity in structure with IgG, the zipFv57S protein showed a higher binding ability and affinity resulting in notable improvement of in vitro neutralizing activity over its corresponding scFv. The zipFv57S protein was also found to be more stable and showed similar protective rate as RIG in mice challenged with a lethal dose of RV. Our results not only indicated zipFv57S as an ideal alternative for RIG in PEP but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced neutralizing potency. Copyright © 2015. Published by Elsevier Ltd.

  9. Single Chain Antibody Fragment against Venom from the Snake Daboia russelii formosensis

    Directory of Open Access Journals (Sweden)

    Chi-Hsin Lee

    2017-10-01

    Full Text Available Russell’s vipers containing hemotoxic and neurotoxic venom commonly cause snake envenomation. Horse-derived antivenom is a specific antidote, but its production is expensive and has side effects. Developing a cost-effective and more tolerable therapeutic strategy is favorable. In this study, using glutaraldehyde-attenuated Daboia russelii formosensis (DRF venom proteins to immunize chickens, polyclonal yolk-immunoglobulin (IgY antibodies were generated and showed a specific binding affinity. Phage display technology was used to generate two antibody libraries of single-chain variable fragments (scFvs containing 3.4 × 107 and 5.5 × 107 transformants, respectively. Phage-based ELISA indicated that specific clones were enriched after bio-panning. The nucleotide sequences of scFv-expressing clones were analyzed and classified into six groups in the short linker and four groups in the long linker. These scFv antibodies specifically bound to DRF proteins, but not other venom proteins. Mass spectrometric data suggested that these scFv antibodies may recognize phospholipase A2 RV-4 or RV-7. In vivo studies showed that anti-DRF IgY exhibited complete protective effects and mixed scFv antibodies increased the survival rate and time of mice challenged with a lethal dose of DRF proteins. These antibodies can be potentially applied in a rapid diagnostic method or for treatment in the future.

  10. Single Chain Antibody Fragment against Venom from the Snake Daboia russelii formosensis.

    Science.gov (United States)

    Lee, Chi-Hsin; Lee, Yu-Ching; Lee, Yueh-Lun; Leu, Sy-Jye; Lin, Liang-Tzung; Chen, Chi-Ching; Chiang, Jen-Ron; Mwale, Pharaoh Fellow; Tsai, Bor-Yu; Hung, Ching-Sheng; Yang, Yi-Yuan

    2017-10-27

    Russell's vipers containing hemotoxic and neurotoxic venom commonly cause snake envenomation. Horse-derived antivenom is a specific antidote, but its production is expensive and has side effects. Developing a cost-effective and more tolerable therapeutic strategy is favorable. In this study, using glutaraldehyde-attenuated Daboia russelii formosensis (DRF) venom proteins to immunize chickens, polyclonal yolk-immunoglobulin (IgY) antibodies were generated and showed a specific binding affinity. Phage display technology was used to generate two antibody libraries of single-chain variable fragments (scFvs) containing 3.4 × 10⁷ and 5.5 × 10⁷ transformants, respectively. Phage-based ELISA indicated that specific clones were enriched after bio-panning. The nucleotide sequences of scFv-expressing clones were analyzed and classified into six groups in the short linker and four groups in the long linker. These scFv antibodies specifically bound to DRF proteins, but not other venom proteins. Mass spectrometric data suggested that these scFv antibodies may recognize phospholipase A2 RV-4 or RV-7. In vivo studies showed that anti-DRF IgY exhibited complete protective effects and mixed scFv antibodies increased the survival rate and time of mice challenged with a lethal dose of DRF proteins. These antibodies can be potentially applied in a rapid diagnostic method or for treatment in the future.

  11. Side chain requirements for affinity and specificity in D5, an HIV-1 antibody derived from the VH1-69 germline segment.

    Science.gov (United States)

    Stewart, Alex; Harrison, Joseph S; Regula, Lauren K; Lai, Jonathan R

    2013-04-08

    Analysis of factors contributing to high affinity antibody-protein interactions provides insight into natural antibody evolution, and guides the design of antibodies with new or enhanced function. We previously studied the interaction between antibody D5 and its target, a designed protein based on HIV-1 gp41 known as 5-Helix, as a model system [Da Silva, G. F.; Harrison, J. S.; Lai, J. R., Biochemistry, 2010, 49, 5464-5472]. Antibody D5 represents an interesting case study because it is derived from the VH1-69 germline segment; this germline segment is characterized by a hydrophobic second heavy chain complementarity determining region (HCDR2) that constitutes the major functional paratope in D5 and several antibodies derived from the same progenitor. Here we explore side chain requirements for affinity and specificity in D5 using phage display. Two D5-based libraries were prepared that contained diversity in all three light chain complementarity determining regions (LCDRs 1-3), and in the third HCDR (HCDR3). The first library allowed residues to vary among a restricted set of six amino acids (Tyr/Ala/Asp/Ser/His/Pro; D5-Lib-I). The second library was designed based on a survey of existing VH1-69 antibody structures (D5-Lib-II). Both libraries were subjected to multiple rounds of selection against 5-Helix, and individual clones characterized. We found that selectants from D5-Lib-I generally had moderate affinity and specificity, while many clones from D5-Lib-II exhibited D5-like properties. Additional analysis of the D5-Lib-II functional population revealed position-specific biases for particular amino acids, many that differed from the identity of those side chains in D5. Together these results suggest that there is some permissiveness for alternative side chains in the LCDRs and HCDR3 of D5, but that replacement with a minimal set of residues is not tolerated in this scaffold for 5-Helix recognition. This work provides novel information about this high

  12. Myosin heavy chain expression in rabbit masseter muscle during postnatal development

    NARCIS (Netherlands)

    Bredman, J. J.; Weijs, W. A.; Korfage, H. A.; Brugman, P.; Moorman, A. F.

    1992-01-01

    The expression of isoforms of myosin heavy chain (MHC) during postnatal development was studied in the masseter muscle of the rabbit. Evidence is presented that in addition to adult fast and slow myosin, the rabbit masseter contains neonatal and 'cardiac' alpha-MHC. During postnatal growth myosin

  13. Expression of porcine myosin heavy chain 1 gene in Berkshire loins ...

    African Journals Online (AJOL)

    Expression of porcine myosin heavy chain 1 gene in Berkshire loins with a high pH24 value. Jin Hun Kang, Woo Young Bang, Eun Jung Kwon, Yong Hwa Lee, Da Hye Park, Eun Seok Cho, Min Ji Kim, Jong-Soon Choi, Hwa Chun Park, Beom Young Park, Chul Wook Kim ...

  14. Ig Light Chain Precedes Heavy Chain Gene Rearrangement during Development of B Cells in Swine

    Czech Academy of Sciences Publication Activity Database

    Šinkora, Marek; Šinkorová, Jana; Štěpánová, Kateřina

    2017-01-01

    Roč. 198, č. 4 (2017), s. 1543-1552 ISSN 0022-1767 R&D Projects: GA ČR GA15-02274S Institutional support: RVO:61388971 Keywords : ANTIBODY REPERTOIRE DEVELOPMENT * ILEAL PEYERS-PATCHES * DELTA T-LYMPHOCYTES Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.856, year: 2016

  15. A Strategy for Generating a Broad-Spectrum Monoclonal Antibody and Soluble Single-Chain Variable Fragments against Plant Potyviruses

    Science.gov (United States)

    Liu, Han-Lin; Lin, Wei-Fang; Hu, Wen-Chi; Lee, Yung-An

    2015-01-01

    Potyviruses are major pathogens that often cause mixed infection in calla lilies. To reduce the time and cost of virus indexing, a detection method for the simultaneous targeting of multiple potyviruses was developed by generating a broad-spectrum monoclonal antibody (MAb) for detecting the greatest possible number of potyviruses. The conserved 121-amino-acid core regions of the capsid proteins of Dasheen mosaic potyvirus (DsMV), Konjak mosaic potyvirus (KoMV), and Zantedeschia mild mosaic potyvirus (ZaMMV) were sequentially concatenated and expressed as a recombinant protein for immunization. After hybridoma cell fusion and selection, one stable cell line that secreted a group-specific antibody, named C4 MAb, was selected. In the reaction spectrum test, the C4 MAb detected at least 14 potyviruses by indirect enzyme-linked immunosorbent assay (I-ELISA) and Western blot analysis. Furthermore, the variable regions of the heavy (VH) and light (VL) chains of the C4 MAb were separately cloned and constructed as single-chain variable fragments (scFvs) for expression in Escherichia coli. Moreover, the pectate lyase E (PelE) signal peptide of Erwinia chrysanthemi S3-1 was added to promote the secretion of C4 scFvs into the medium. According to Western blot analysis and I-ELISA, the soluble C4 scFv (VL-VH) fragment showed a binding specificity similar to that of the C4 MAb. Our results demonstrate that a recombinant protein derived from fusion of the conserved regions of viral proteins has the potential to produce a broad-spectrum MAb against a large group of viruses and that the PelE signal peptide can improve the secretion of scFvs in E. coli. PMID:26209665

  16. Myosin heavy chain profile of equine gluteus medius muscle following prolonged draught-exercise training and detraining.

    Science.gov (United States)

    Serrano, A L; Rivero, J L

    2000-04-01

    Fourteen 4-year old Andalusian mares were used to examine the plasticity of myosin heavy chain (MHC) composition in horse skeletal muscle with heavy draught-exercise training and detraining. Seven horses underwent a training programme based on carriage exercises for 8 months. Afterwards, they were kept in paddocks for 3 months. The remaining seven animals were used as control horses. Three gluteus medius muscle biopsies were removed at depths of 20, 40 and 60 mm from each horse before (month 0), during the training (months 3 and 8) and after detraining (month 11). Myosin heavy chain composition was analysed by electrophoresis and immunohistochemically with anti-MHC monoclonal antibodies. Fibre areas, oxidative capacity and capillaries were studied histochemically. After 8 months of training, MHC-IIX and IIX fibres decreased whereas MHC-I and type I and I + IIA fibres increased. Neither MHC-IIA nor the percentage of IIA fibres changed when the data were considered as a whole, but the proportion of MHC-IIA increased in the superficial region of the muscle after 8 months of training. Mean areas of type II fibres were not affected by training and detraining, but the cross-sectional of type I fibres increased after 3 month of training and not further increases were recorded afterward. The percentage of high-oxidative capacity fibres and the number of capillaries per mm2 increased with training. Most of these muscular adaptations reverted after detraining. These results indicate that long term draught-exercise training induces a reversible transition of MHC composition in equine muscle in the order IIX --> IIA --> I. The physiological implication of these changes is an impact on the velocity of shortening and fatigue resistance of muscle fibres.

  17. Detection of clonal immunoglobulin heavy chain gene rearrangements by the polymerase chain reaction and capillary gel electrophoresis.

    Science.gov (United States)

    Fan, Hongxin; Robetorye, Ryan S

    2013-01-01

    Although well-established diagnostic criteria exist for mature B-cell neoplasms, a definitive diagnosis of a B-cell lymphoproliferative disorder cannot always be obtained using more conventional techniques such as flow cytometric immunophenotyping, conventional cytogenetics, fluorescence in situ hybridization, or immunohistochemistry. However, because B-cell malignancies contain identically rearranged immunoglobulin heavy chain genes, the polymerase chain reaction (PCR) can be a fast, convenient, and dependable option to identify clonal B-cell processes. This chapter describes the use of PCR and capillary electrophoresis to identify clonal immunoglobulin heavy chain (IGH) variable and joining region (VH-JH) gene rearrangements (IGH VH-JH PCR) using a commercially available method employing multiple multiplex PCR tubes that was originally developed as the result of a large European BIOMED-2 collaborative study (Invivoscribe Technologies). The core protocol involves the use of three separate master mix tubes that target the conserved framework (FR1, FR2, and FR3) and joining (J) regions of the IGH gene. Analysis of these three framework regions can detect approximately 88% of clonal IGH gene rearrangements.

  18. Shark Ig light chain junctions are as diverse as in heavy chains.

    Science.gov (United States)

    Fleurant, Marshall; Changchien, Lily; Chen, Chin-Tung; Flajnik, Martin F; Hsu, Ellen

    2004-11-01

    We have characterized a small family of four genes encoding one of the three nurse shark Ig L chain isotypes, called NS5. All NS5 cDNA sequences are encoded by three loci, of which two are organized as conventional clusters, each consisting of a V and J gene segment that can recombine and one C region exon; the third contains a germline-joined VJ in-frame and the fourth locus is a pseudogene. This is the second nurse shark L chain type where both germline-joined and split V-J organizations have been found. Since there are only two rearranging Ig loci, it was possible for the first time to examine junctional diversity in defined fish Ig genes, comparing productive vs nonproductive rearrangements. N region addition was found to be considerably more extensive in length and in frequency than any other vertebrate L chain so far reported and rivals that in H chain. We put forth the speculation that the unprecedented efficiency of N region addition (87-93% of NS5 sequences) may be a result not only of simultaneous H and L chain rearrangement in the shark but also of processing events that afford greater accessibility of the V or J gene coding ends to terminal deoxynucleotidyltransferase.

  19. Heavy and Light chain amyloidosois presenting as complete heart block: A rare presentation of a rare disease.

    Science.gov (United States)

    Priyamvada, P S; Morkhandikar, S; Srinivas, B H; Parameswaran, S

    2015-01-01

    Amyloidosis is an uncommon disease characterized by deposition of proteinaceous material in the extracellular matrix, which results from abnormal protein folding. Even though more than 25 precursor proteins are identified, majority of systemic amyloidosis results from deposition of abnormal immunoglobulin (Ig) light chains. In heavy chain amyloidosis (AH), deposits are derived from both heavy chain alone, whereas in heavy and light chain amyloidosis (AHL), the deposits are derived from Ig heavy chains and light chains. Both AH and AHL are extremely rare diseases. Here, we report an unusual presentation of IgG (lambda) AHL amyloidosis in the background of multiple myeloma, where the initial clinical presentation was complete heart block, which preceded the definitive diagnosis by 18 months.

  20. Heavy and Light chain amyloidosois presenting as complete heart block: A rare presentation of a rare disease

    Directory of Open Access Journals (Sweden)

    P S Priyamvada

    2015-01-01

    Full Text Available Amyloidosis is an uncommon disease characterized by deposition of proteinaceous material in the extracellular matrix, which results from abnormal protein folding. Even though more than 25 precursor proteins are identified, majority of systemic amyloidosis results from deposition of abnormal immunoglobulin (Ig light chains. In heavy chain amyloidosis (AH, deposits are derived from both heavy chain alone, whereas in heavy and light chain amyloidosis (AHL, the deposits are derived from Ig heavy chains and light chains. Both AH and AHL are extremely rare diseases. Here, we report an unusual presentation of IgG (lambda AHL amyloidosis in the background of multiple myeloma, where the initial clinical presentation was complete heart block, which preceded the definitive diagnosis by 18 months.

  1. Immunoglobulin G4: an odd antibody

    NARCIS (Netherlands)

    Aalberse, R. C.; Stapel, S. O.; Schuurman, J.; Rispens, T.

    2009-01-01

    Despite its well-known association with IgE-mediated allergy, IgG4 antibodies still have several poorly understood characteristics. IgG4 is a very dynamic antibody: the antibody is involved in a continuous process of half-molecules (i.e. a heavy and attached light-chain) exchange. This process, also

  2. Clathrin Heavy Chain Is Important for Viability, Oviposition, Embryogenesis and, Possibly, Systemic RNAi Response in the Predatory Mite Metaseiulus occidentalis

    Science.gov (United States)

    Wu, Ke; Hoy, Marjorie A.

    2014-01-01

    Clathrin heavy chain has been shown to be important for viability, embryogenesis, and RNA interference (RNAi) in arthropods such as Drosophila melanogaster. However, the functional roles of clathrin heavy chain in chelicerate arthropods, such as the predatory mite Metaseiulus occidentalis, remain unknown. We previously showed that dsRNA ingestion, followed by feeding on spider mites, induced systemic and robust RNAi in M. occidentalis females. In the current study, we performed a loss-of-function analysis of the clathrin heavy chain gene in M. occidentalis using RNAi. We showed that ingestion of clathrin heavy chain dsRNA by M. occidentalis females resulted in gene knockdown and reduced longevity. In addition, clathrin heavy chain dsRNA treatment almost completely abolished oviposition by M. occidentalis females and the few eggs produced did not hatch. Finally, we demonstrated that clathrin heavy chain gene knockdown in M. occidentalis females significantly reduced a subsequent RNAi response induced by ingestion of cathepsin L dsRNA. The last finding suggests that clathrin heavy chain may be involved in systemic RNAi responses mediated by orally delivered dsRNAs in M. occidentalis. PMID:25329675

  3. Early Bronchus-Associated Lymphoid Tissue Lymphoma Diagnosed with Immunoglobulin Heavy Chain Molecular Testing

    Directory of Open Access Journals (Sweden)

    Pen Li

    2016-01-01

    Full Text Available When extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT, a low grade B-cell lymphoma, arises in the lung it is referred to as bronchus-associated lymphoid tissue (BALT lymphoma. We describe a patient with a history of Sjögren’s syndrome and rheumatoid arthritis with dyspnea and imaging consistent with lymphoid interstitial pneumonia (LIP. However, while histology and immunohistochemistry lacked definitive features of a lymphoma, immunoglobulin heavy chain (IgH polymerase chain reaction testing demonstrated B-cell monoclonality, consistent with an early BALT lymphoma.

  4. The in vivo characteristics of genetically engineered divalent and tetravalent single-chain antibody constructs

    International Nuclear Information System (INIS)

    Wittel, Uwe A.; Jain, Maneesh; Goel, Apollina; Chauhan, Subhash C.; Colcher, David; Batra, Surinder K.

    2005-01-01

    Engineered multivalent single-chain Fv (scFv) constructs have been demonstrated to exhibit rapid blood clearance and better tumor penetration. To understand the short plasma half-life of multivalent single-chain antibody fragments, the pharmacokinetic properties of covalent dimeric scFv [sc(Fv) 2 ], noncovalent tetrameric scFv {[sc(Fv) 2 ] 2 } and IgG of MAb CC49 were examined. The scFvs displayed an ability to form higher molecular aggregates in vivo. A specific proteolytic cleavage of the linker sequence of the covalent dimeric or a deterioration of the noncovalent association of the dimeric scFv into tetravalent scFv constructs was not observed. In conclusion, sc(Fv) 2 and [sc(Fv) 2 ] 2 are stable in vivo and have significant potential for diagnostic and therapeutic applications

  5. Use of bortezomib in heavy-chain deposition disease: a report of 3 cases.

    Science.gov (United States)

    Patel, Kinjal; Dillon, John J; Leung, Nelson; Bomback, Andrew S; Appel, Gerald B; D'Agati, Vivette; Canetta, Pietro A

    2014-07-01

    Heavy-chain deposition disease (HCDD) is a rare complication of plasma cell dyscrasia in which monoclonal heavy chains deposit in glomerular and tubular basement membranes of the kidney. Clinical and pathologic features of HCDD have been well described in case reports and series, but evidence supporting specific therapies is sparse. Historically, the disease has had a poor prognosis, intensifying the need to clarify optimal treatments. We describe 3 cases of HCDD with biopsy-proven glomerular involvement, severe nephrotic syndrome, and decline in kidney function that were treated successfully with bortezomib, a proteasome inhibitor. None of these patients had multiple myeloma. In all cases, bortezomib-based therapy resulted in sustained resolution of nephrotic syndrome and improvement in kidney function. All 3 patients developed peripheral neuropathy; otherwise, treatment was well tolerated. To our knowledge, this is the first description of the clinical effectiveness of bortezomib against HCDD. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  6. Genetic stability of gene targeted immunoglobulin loci. I. Heavy chain isotype exchange induced by a universal gene replacement vector.

    Science.gov (United States)

    Kardinal, C; Selmayr, M; Mocikat, R

    1996-11-01

    Gene targeting at the immunoglobulin loci of B cells is an efficient tool for studying immunoglobulin expression or generating chimeric antibodies. We have shown that vector integration induced by human immunoglobulin G1 (IgG1) insertion vectors results in subsequent vector excision mediated by the duplicated target sequence, whereas replacement events which could be induced by the same constructs remain stable. We could demonstrate that the distribution of the vector homology strongly influences the genetic stability obtained. To this end we developed a novel type of a heavy chain replacement vector making use of the heavy chain class switch recombination sequence. Despite the presence of a two-sided homology this construct is universally applicable irrespective of the constant gene region utilized by the B cell. In comparison to an integration vector the frequency of stable incorporation was strongly increased, but we still observed vector excision, although at a markedly reduced rate. The latter events even occurred with circular constructs. Linearization of the construct at various sites and the comparison with an integration vector that carries the identical homology sequence, but differs in the distribution of homology, revealed the following features of homologous recombination of immunoglobulin genes: (i) the integration frequency is only determined by the length of the homology flank where the cross-over takes place; (ii) a 5' flank that does not meet the minimum requirement of homology length cannot be complemented by a sufficient 3' flank; (iii) free vector ends play a role for integration as well as for replacement targeting; (iv) truncating recombination events are suppressed in the presence of two flanks. Furthermore, we show that the switch region that was used as 3' flank is non-functional in an inverted orientation.

  7. Modification of Antibody Function by Mutagenesis.

    Science.gov (United States)

    Dasch, James R; Dasch, Amy L

    2017-09-01

    The ability to "fine-tune" recombinant antibodies by mutagenesis separates recombinant antibodies from hybridoma-derived antibodies because the latter are locked with respect to their properties. Recombinant antibodies can be modified to suit the application: Changes in isotype, format (e.g., scFv, Fab, bispecific antibodies), and specificity can be made once the heavy- and light-chain sequences are available. After immunoglobulin heavy and light chains for a particular antibody have been cloned, the binding site-namely, the complementarity determining regions (CDR)-can be manipulated by mutagenesis to obtain antibody variants with improved properties. The method described here is relatively simple, uses commercially available reagents, and is effective. Using the pComb3H vector, a commercial mutagenesis kit, PfuTurbo polymerase (Agilent), and two mutagenic primers, a library of phage with mutagenized heavy and light CDR3 can be obtained. © 2017 Cold Spring Harbor Laboratory Press.

  8. Cell surface expression of single chain antibodies with applications to imaging of gene expression in vivo

    International Nuclear Information System (INIS)

    Northrop, Jeffrey P.; Bednarski, Mark; Li, King C.; Barbieri, Susan O.; Lu, Amy T.; Nguyen, Dee; Varadarajan, John; Osen, Maureen; Star-Lack, Josh

    2003-01-01

    Imaging of gene expression in vivo has many potential uses for biomedical research and drug discovery, ranging from the study of gene regulation and cancer to the non-invasive assessment of gene therapies. To streamline the development of imaging marker gene technologies for nuclear medicine, we propose a new approach to the design of reporter/probe pairs wherein the reporter is a cell surface-expressed single chain antibody variable fragment that has been raised against a low molecular weight imaging probe with optimized pharmacokinetic properties. Proof of concept of the approach was achieved using a single chain antibody variable fragment that binds with high affinity to fluorescein and an imaging probe consisting of fluorescein isothiocyanate coupled to the chelator diethylene triamine penta-acetic acid labeled with the gamma-emitter 111 In. We demonstrate specific high-affinity binding of this probe to the cell surface-expressed reporter in vitro and assess the in vivo biodistribution of the probe both in wild-type mice and in mice harboring tumor xenografts expressing the reporter. Specific uptake of the probe by, and in vivo imaging of, tumors expressing the reporter are shown. Since ScFvs with high affinities can be raised to almost any protein or small molecule, the proposed methodology may offer a new flexibility in the design of imaging tracer/reporter pairs wherein both probe pharmacokinetics and binding affinities can be readily optimized. (orig.)

  9. Fusion Peptide Improves Stability and Bioactivity of Single Chain Antibody against Rabies Virus.

    Science.gov (United States)

    Xi, Hualong; Zhang, Kaixin; Yin, Yanchun; Gu, Tiejun; Sun, Qing; Shi, Linqing; Zhang, Renxia; Jiang, Chunlai; Kong, Wei; Wu, Yongge

    2017-04-28

    The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and halflife. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

  10. Increased myosin heavy chain-beta with atrial expression of ventricular light chain-2 in canine cardiomyopathy.

    Science.gov (United States)

    Fuller, Geraldine A; Bicer, Sabahattin; Hamlin, Robert L; Yamaguchi, Mamoru; Reiser, Peter J

    2007-10-01

    Dilated cardiomyopathy is a naturally occurring disease in humans and dogs. Human studies have shown increased levels of myosin heavy chain (MHC)-beta in failing ventricles and the left atria (LA) and of ventricular light chain (VLC)-2 in the right atria in dilated cardiomyopathy. This study evaluates the levels of MHC-beta in all heart chambers in prolonged canine right ventricular pacing. In addition, we determined whether levels of VLC2 were altered in these hearts. Failing hearts demonstrated significantly increased levels of MHC-beta in the right atria, right atrial appendage, LA, left atrial appendage (LAA), and right ventricle compared with controls. Significant levels of VLC2 were detected in the right atria of paced hearts. Differences in MHC-beta expression were observed between the LA and the LAA of paced and control dogs. MHC-beta expression was significantly greater in the LA of paced and control dogs compared with their respective LAA. The cardiac myosin isoform shifts in this study were similar to those observed in end-stage human heart failure and more severe than those reported in less prolonged pacing models, supporting the use of this model for further study of end-stage human heart failure. The observation of consistent differences between sampling sites, especially LA versus LAA, indicates the need for rigorous sampling consistency in future studies.

  11. Kinetic analysis of a monoclonal therapeutic antibody and its single-chain homolog by surface plasmon resonance.

    Science.gov (United States)

    Patel, Rekha; Andrien, Bruce A

    2010-01-01

    Monoclonal antibodies (mAbs) and antibody fragments have become an emerging class of therapeutics since 1986. Their versatility enables them to be engineered for optimal efficiency and decreased immunogenicity, and the path to market has been set by recent regulatory approvals. One of the initial criteria for success of any protein or antibody therapeutic is to understand its binding characteristics to the target antigen. Surface plasmon resonance (SPR) has been widely used and is an important tool for ligand-antigen binding characterization. In this work, the binding kinetics of a recombinant mAb and its single-chain antibody homolog, single-chain variable fragment (scFv), was analyzed by SPR. These two proteins target the same antigen. The binding kinetics of the mAb (bivalent antibody) and scFv (monovalent scFv) for this antigen was analyzed along with an assessment of the thermodynamics of the binding interactions. Alternative binding configurations were investigated to evaluate potential experimental bias because theoretically experimental binding configuration should have no impact on binding kinetics. Self-association binding kinetics in the proteins' respective formulation solutions and antigen epitope mapping were also evaluated. Functional characterization of monoclonal and single-chain antibodies has become just as important as structural characterization in the biotechnology field.

  12. Variation in N-linked carbohydrate chains in different batches of two chimeric monoclonal IgG1 antibodies produced by different murine SP2/0 transfectoma cell subclones.

    Science.gov (United States)

    Bergwerff, A A; Stroop, C J; Murray, B; Holtorf, A P; Pluschke, G; Van Oostrum, J; Kamerling, J P; Vliegenthart, J F

    1995-06-01

    Two chimeric human/murine monoclonal antibodies were constructed by substitution of the murine constant regions with human gamma 1 and kappa constant regions for heavy and light chains, respectively. The chimeric human/murine molecules are anti-idiotypic antibodies, meaning that they were directed against the antigen binding site in the variable region of another antibody. Antibody batches were produced under identical production conditions, using two selected SP2/0 myeloma cell subclones, which produce chimeric antibodies with different variable regions, but identical constant regions. Several samples were collected during the production of the antibodies in hollow-fibre reactors. The heavy chain, but not the light chain, of the two different chimeric IgG1 antibodies is glycosylated. Structural analysis of the enzymically released N-linked carbohydrate chains by 1H-NMR spectroscopy, as well as by chromatographic profiling, demonstrated that the collection of N-glycans comprises a small amount of monoantennary, and for the greater part diantennary structures. The N-glycans are completely (alpha 1-->6)-fucosylated at the innermost GlcNAc residue. The antennae of the neutral diantennary N-glycans are built up from GlcNAc beta 1-->2, Gal beta 1-->4GlcNAc beta 1-->2 or Gal alpha 1-->3G alpha 1 beta 1-->4GlcNAc beta 1-->2 elements, whereas the antennae of the neutral monoantennary carbohydrate chains have only (beta 1-->2)-linked GlcNAc residues. Galactosylation of the GlcNAc beta 1-->2Man alpha 1-->6 branch occurs four times more frequently than that of the GlcNAc beta 1-->2Man alpha 1-->3 branch, independently of the production batch. A small amount of the diantennary N-glycans are mono- or disialylated, carrying N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc), exclusively (alpha 2-->6)-linked to beta Gal. Analysis of the different production batches demonstrates that the structures of the N-linked carbohydrate chains are identical in the two

  13. Myosin heavy chain composition of single fibres from m. biceps brachii of male body builders

    DEFF Research Database (Denmark)

    Klitgaard, H; Zhou, M.-Y.; Richter, Erik

    1990-01-01

    The myosin heavy chain (MHC) composition of single fibres from m. biceps brachii of young sedentary men (28 +/- 0.4 years, mean +/- SE, n = 4) and male body builders (25 +/- 2.0 years, n = 4) was analysed with a sensitive one-dimensional electrophoretic technique. Compared with sedentary men...... expression of MHC isoforms within histochemical type II fibres of human skeletal muscle with body building. Furthermore, in human skeletal muscle differences in expression of MHC isoforms may not always be reflected in the traditional histochemical classification of types I, IIa, IIb and IIc fibres....

  14. Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay for Glycocholic Acid Based on Chicken Single-Chain Variable Fragment Antibodies.

    Science.gov (United States)

    Cui, Xiping; Vasylieva, Natalia; Wu, Panpan; Barnych, Bogdan; Yang, Jun; Shen, Ding; He, Qiyi; Gee, Shirley J; Zhao, Suqing; Hammock, Bruce D

    2017-10-17

    Glycocholic acid (GCA) is an important metabolite of bile acids, whose urine levels are expected to be a specific diagnostic biomarker for hepatocellular carcinoma (HCC). A high-throughput immunoassay for determination of GCA would be of significant advantage and useful for primary diagnosis, surveillance, and early detection of HCC. Single-chain variable fragment (scFv) antibodies have several desirable characteristics and are an attractive alternative to traditional antibodies for the immunoassay. Because chicken antibodies possess single heavy and light variable functional domains, they are an ideal framework for simplified generation of recombinant antibodies for GCA detection. However, chicken scFvs have rarely been used to detect GCA. In this study, a scFv library was generated from chickens immunized with a GCA hapten coupled to bovine serum albumin (BSA), and anti-GCA scFvs were isolated by a phage-displayed method. Compared to the homologous coating antigen, use of a heterologous coating antigen resulted in about an 85-fold improvement in sensitivity of the immunoassay. This assay, under optimized conditions, had a linear range of 0.02-0.18 μg/mL, with an IC 50 of 0.06 μg/mL. The assay showed negligible cross-reactivity with various related bile acids, except for taurocholic acid. The detection of GCA from spiked human urine samples ranged from 86.7% to 123.3%. These results, combined with the advantages of scFv antibodies, indicated that a chicken scFv-based enzyme-linked immunosorbent assay is a suitable method for high-throughput screening of GCA in human urine.

  15. Immunoglobulin Heavy Chain Variable Region and Major Histocompatibility Region Genes Are Linked to Induced Graves' Disease in Females From Two Very Large Families of Recombinant Inbred Mice

    Science.gov (United States)

    Aliesky, Holly; Banuelos, Bianca; Magana, Jessica; Williams, Robert W.; Rapoport, Basil

    2014-01-01

    Graves' hyperthyroidism is caused by antibodies to the TSH receptor (TSHR) that mimic thyroid stimulation by TSH. Stimulating TSHR antibodies and hyperthyroidism can be induced by immunizing mice with adenovirus expressing the human TSHR A-subunit. Prior analysis of induced Graves' disease in small families of recombinant inbred (RI) female mice demonstrated strong genetic control but did not resolve trait loci for TSHR antibodies or elevated serum T4. We investigated the genetic basis for induced Graves' disease in female mice of two large RI families and combined data with earlier findings to provide phenotypes for 178 genotypes. TSHR antibodies measured by inhibition of TSH binding to its receptor were highly significantly linked in the BXD set to the major histocompatibility region (chromosome 17), consistent with observations in 3 other RI families. In the LXS family, we detected linkage between T4 levels after TSHR-adenovirus immunization and the Ig heavy chain variable region (Igvh, chromosome 12). This observation is a key finding because components of the antigen binding region of Igs determine antibody specificity and have been previously linked to induced thyroid-stimulating antibodies. Data from the LXS family provide the first evidence in mice of a direct link between induced hyperthyroidism and Igvh genes. A role for major histocompatibility genes has now been established for genetic susceptibility to Graves' disease in both humans and mice. Future studies using arrays incorporating variation in the complex human Ig gene locus will be necessary to determine whether Igvh genes are also linked to Graves' disease in humans. PMID:25051451

  16. Effective single chain antibody (scFv) concentrations in vivo via adenoviral vector mediated expression of secretory scFv

    NARCIS (Netherlands)

    Arafat, WO; Gomez-Navarro, J; Buchsbaum, DJ; Xiang, J; Casado, E; Barker, SD; Mahasreshti, PJ; Haisma, HJ; Barnes, MN; Siegal, GP; Alvarez, RD; Hemminki, A; Nettelbeck, DM; Curiel, DT

    Single chain antibodies (scFv) represent powerful interventional agents for the achievement of targeted therapeutics. The practical utility of these agents have been limited, however, by difficulties related to production of recombinant scFv and the achievement of effective and sustained levels of

  17. Reduction in beta-myosin heavy chains in stunned myocardium as assessed by nondenaturing gel electrophoresis.

    Science.gov (United States)

    Garcia, S C; Pomblum, V J; Gams, E; Rupp, H; Schipke, J D

    2007-09-01

    Myosin plays a key role in the structure and function of cardiac muscle. Three myosin isoenzymes (V(1), V(2), and V(3)) with different ATPase activities have been identified in mammalian ventricles based on their heavy chain constituents. The relative amount of myosin isoenzymes changes under physiological and pathological conditions. Until now, myosin isoenzymes have frequently been determined using either tube gel (nondenaturing) polyacrylamide gel electrophoresis (PAGE), or gradient or uniform sodium dodecyl sulfate (denaturing) PAGE. Both methods have disadvantages, e.g., a long running time. We developed, therefore, a uniform, nondenaturing PAGE with slab minigel format for analyzing the myosin isoenzymes in normoxic and stunned rabbit hearts. In normoxic hearts of adult rabbits, V(3) predominated over V(1) (46 vs 41%). In turn, in the stunned hearts, V(1) predominated over V(3) (70 vs 30%), and the heterodimeric V(2) was not anymore detectable. This alteration appears to result from a selective loss of myosin heavy chain (MHC)-beta. In parallel, the biochemical markers troponin I and creatine kinase were increased in the stunned hearts. We suggest that alterations of myosin isoenzymes in stunned myocardium can be monitored with native PAGE. The present analysis of myosin isoenzyme appears thus as a new tool for evaluating defects in MHC dimer formation in postischemic hearts.

  18. Screening for single-chain variable fragment antibodies against multiple Cry1 toxins from an immunized mouse phage display antibody library.

    Science.gov (United States)

    Dong, Sa; Bo, Zongyi; Zhang, Cunzheng; Feng, Jianguo; Liu, Xianjin

    2018-04-01

    Single-chain variable fragment (scFv) is a kind of antibody that possess only one chain of the complete antibody while maintaining the antigen-specific binding abilities and can be expressed in prokaryotic system. In this study, scFvs against Cry1 toxins were screened out from an immunized mouse phage displayed antibody library, which was successfully constructed with capacity of 6.25 × 10 7  CFU/mL. Using the mixed and alternative antigen coating strategy and after four rounds of affinity screening, seven positive phage-scFvs against Cry1 toxins were selected and characterized. Among them, clone scFv-3H9 (MG214869) showing relative stable and high binding abilities to six Cry1 toxins was selected for expression and purification. SDS-PAGE indicated that the scFv-3H9 fragments approximately 27 kDa were successfully expressed in Escherichia coli HB2151 strain. The purified scFv-3H9 was used to establish the double antibody sandwich enzyme-linked immunosorbent assay method (DAS-ELISA) for detecting six Cry1 toxins, of which the lowest detectable limits (LOD) and the lowest quantitative limits (LOQ) were 3.14-11.07 and 8.22-39.44 ng mL -1 , respectively, with the correlation coefficient higher than 0.997. The average recoveries of Cry1 toxins from spiked rice leaf samples were ranged from 84 to 95%, with coefficient of variation (CV) less than 8.2%, showing good accuracy for the multi-residue determination of six Cry1 toxins in agricultural samples. This research suggested that the constructed phage display antibody library based on the animal which was immunized with the mixture of several antigens under the same category can be used for the quick and effective screening of generic antibodies.

  19. Direct photoaffinity labeling by nucleotides of the apparent catalytic site on the heavy chains of smooth muscle and Acanthamoeba myosins

    International Nuclear Information System (INIS)

    Maruta, H.; Korn, E.D.

    1981-01-01

    The heavy chains of Acanthamoeba myosins, IA, IB and II, turkey gizzard myosin, and rabbit skeletal muscle myosin subfragment-1 were specifically labeled by radioactive ATP, ADP, and UTP, each of which is a substrate or product of myosin ATPase activity, when irradiated with uv light at 0 0 C. With UTP, as much as 0.45 mol/mol of Acanthamoeba myosin IA heavy chain and 1 mol/mol of turkey gizzard myosin heavy chain was incorporated. Evidence that the ligands were associated with the catalytic site included the observations that reaction occurred only with nucleotides that are substrates or products of the ATPase activity; that the reaction was blocked by pyrophosphate which is an inhibitor of the ATPase activity; that ATP was bound as ADP; and that label was probably restricted to a single peptide following limited subtilisin proteolysis of labeled Acanthamoeba myosin IA heavy chain and extensive cleavage with CNBr and trypsin of labeled turkey gizzard myosin heavy chain

  20. Epitope mapping of the alpha-chain of the insulin-like growth factor I receptor using antipeptide antibodies.

    Science.gov (United States)

    Delafontaine, P; Ku, L; Ververis, J J; Cohen, C; Runge, M S; Alexander, R W

    1994-12-01

    Insulin-like growth factor I (IGF I) is an important mitogen for vascular smooth muscle cells (VSMC). The IGF I receptor (IGF IR) is a heterotetramer composed of two cross-linked extracellular alpha-chains and two membrane-spanning beta-chains that contain a tyrosine-kinase domain. It has a high degree of sequence similarity to the insulin receptor (IR), and the putative ligand-specific binding site has been localized to a cysteine-rich region (CRR) of the alpha-chain. To obtain insights into antigenic determinants of the IGF IR, we raised a panel of site-specific polyclonal antibodies against short peptide sequences N-terminal to and within the CRR. Several antibodies raised against linear epitopes within the CRR bound to solubilized and native rat and human IGF IR by ELISA, did not cross-react with IR, but unexpectedly failed to inhibit 125I-IGF I binding. A polyclonal antibody directed against a 48-amino acid synthetic peptide, corresponding to a region of the CRR postulated to be essential for ligand binding, failed to react with either solubilized, reduced or intact IGF IR. Three antibodies specific for the N-terminus of the alpha-chain reacted with solubilized and native IGF IR. One of these, RAB 6, directed against amino acids 38-44 of the IGF IR, inhibited 125I-IGF I binding to rat aortic smooth muscle cells (RASM) and to IGF IR/3T3 cells (overexpressing human IGF IR) by up to 45%. Immunohistochemical analysis revealed strong IGF IR staining in the medial smooth muscle cell layer of rat aorta. These findings are consistent with a model wherein conformational epitopes within the CRR and linear epitopes within the N-terminus of the alpha-chain contribute to the IGF I binding pocket. These antibodies should provide a valuable tool to study structure-function relationships and in vivo regulation of the IGF IR.

  1. Nanobodies - the new concept in antibody engineering

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... These heavy-chain antibodies contain a single variable domain (VHH) and two ... clonal antibody products were on the market and more than 100 in ..... genous showing no sign of spontaneous dimerisation in contrast to scFv ...

  2. Reshaping Human Antibodies: Grafting an Antilysozyme Activity

    Science.gov (United States)

    Verhoeyen, Martine; Milstein, Cesar; Winter, Greg

    1988-03-01

    The production of therapeutic human monoclonal antibodies by hybridoma technology has proved difficult, and this has prompted the ``humanizing'' of mouse monoclonal antibodies by recombinant DNA techniques. It was shown previously that the binding site for a small hapten could be grafted from the heavy-chain variable domain of a mouse antibody to that of a human myeloma protein by transplanting the hypervariable loops. It is now shown that a large binding site for a protein antigen (lysozyme) can also be transplanted from mouse to human heavy chain. The success of such constructions may be facilitated by an induced-fit mechanism.

  3. Bioaccumulative and conchological assessment of heavy metal transfer in a soil-plant-snail food chain

    Directory of Open Access Journals (Sweden)

    Nica Dragos V

    2012-06-01

    Full Text Available Abstract Background Copper (Cu, zinc (Zn, cadmium (Cd, and lead (Pb can pose serious threats to environmental health because they tend to bioaccumulate in terrestrial ecosystems. We investigated under field conditions the transfer of these heavy metals in a soil-plant-snail food chain in Banat area, Romania. The main goal of this paper was to assess the Roman snail (Helix pomatia usefulness in environmental monitoring as bioindicator of heavy metal accumulation. Eight sampling sites, selected by different history of heavy metal (HM exposure, were chosen to be sampled for soil, nettle leaves, and newly matured snails. This study also aimed to identify the putative effects of HM accumulation in the environment on phenotypic variability in selected shell features, which included shell height (SH, relative shell height (RSH, and whorl number (WN. Results Significantly higher amounts of HMs were accumulated in snail hepatopancreas and not in foot. Cu, Zn, and Cd have biomagnified in the snail body, particularly in the hepatopancreas. In contrast, Pb decreased when going up into the food chain. Zn, Cd, and Pb correlated highly with each other at all levels of the investigated food chain. Zn and Pb exhibited an effective soil–plant transfer, whereas in the snail body only foot Cu concentration was correlated with that in soil. There were significant differences among sampling sites for WN, SH, and RSH when compared with reference snails. WN was strongly correlated with Cd and Pb concentrations in nettle leaves but not with Cu and Zn. SH was independent of HM concentrations in soil, snail hepatopancreas, and foot. However, SH correlated negatively with nettle leaves concentrations for each HM except Cu. In contrast, RSH correlated significantly only with Pb concentration in hepatopancreas. Conclusions The snail hepatopancreas accumulates high amounts of HMs, and therefore, this organ can function as a reliable biomarker for tracking HM bioavailability

  4. Immunolabelling, histochemistry and in situ hybridisation in human skeletal muscle fibres to detect myosin heavy chain expression at the protein and mRNA level

    Science.gov (United States)

    SERRANO, A. L.; PÉREZ, MARGARITA; LUCÍA, A.; CHICHARRO, J. L.; QUIROZ-ROTHE, E.; RIVERO, J. L. L.

    2001-01-01

    The distribution of muscle fibres classified on the basis of their content of different myosin heavy chain (MHC) isoforms was analysed in vastus lateralis muscle biopsies of 15 young men (with an average age of 22 y) by correlating immunohistochemistry with specific anti-MHC monoclonal antibodies, myofibrillar ATPase (mATPase) histochemistry and in situ hybridisation with probes specific for MHC β-slow, MHC-IIA and MHC-IIX. The characterisation of a large number of individual fibres was compared and correlated on a fibre-to-fibre basis. The panel of monoclonal antibodies used in the study allowed classification of human skeletal muscle fibres into 5 categories according to the MHC isoform they express at the protein level, types I, I+IIA, IIA, IIAX and IIX. Hybrid fibres coexpressing two isoforms represented a considerable proportion of the fibre composition (about 14%) and were clearly underestimated by mATPase histochemistry. For a very high percentage of fibres there was a precise correspondence between the MHC protein isoforms and mRNA transcripts. The integrated methods used demonstrate a high degree of precision of the immunohistochemical procedure used for the identification and quantification of human skeletal muscle fibre types. The monoclonal antibody S5-8H2 is particularly useful for identifying hybrid IIAX fibres. This protocol offers new prospects for muscle fibre classification in human experimental studies. PMID:11554510

  5. Characterization of a Single Chain Fv Antibody that Reacts with Free Morphine

    Directory of Open Access Journals (Sweden)

    Kazuhisa Sugimura

    2013-02-01

    Full Text Available An immune phage library derived from mice, hyperimmunized with morphine-conjugated BSA, was used to isolate a single-chain Fv (scFv clone, M86, with binding activity to morphine-conjugated thyroglobulin (morphine-C-Tg but not to codeine-, cocaine-, or ketamine-conjugated Tg. Surface plasmon resonance analysis using a morphine-C-Tg-coupled CM5 sensor chip showed that the Kd value was 1.26 × 10−8 M. To analyze its binding activity to free morphine and related compounds, we performed a competitive ELISA with M86 and morphine-C-Tg in the absence or presence of varying doses of free morphine and related compounds. IC50 values for opium, morphine, codeine, and heroin were 257 ng/mL, 36.4, 7.3, and 7.4 nM, respectively. Ketamine and cocaine exhibited no competitive binding activity to M86. Thus, we established a phage library-derived scFv, M86, which recognized not only free morphine and codeine as opium components but also heroin. This characteristic of M86 may be useful for developing therapeutic reagents for opiate addiction and as a free morphine-specific antibody probe.

  6. Protective Effects of Clenbuterol against Dexamethasone-Induced Masseter Muscle Atrophy and Myosin Heavy Chain Transition.

    Directory of Open Access Journals (Sweden)

    Daisuke Umeki

    Full Text Available Glucocorticoid has a direct catabolic effect on skeletal muscle, leading to muscle atrophy, but no effective pharmacotherapy is available. We reported that clenbuterol (CB induced masseter muscle hypertrophy and slow-to-fast myosin heavy chain (MHC isoform transition through direct muscle β2-adrenergic receptor stimulation. Thus, we hypothesized that CB would antagonize glucocorticoid (dexamethasone; DEX-induced muscle atrophy and fast-to-slow MHC isoform transition.We examined the effect of CB on DEX-induced masseter muscle atrophy by measuring masseter muscle weight, fiber diameter, cross-sectional area, and myosin heavy chain (MHC composition. To elucidate the mechanisms involved, we used immunoblotting to study the effects of CB on muscle hypertrophic signaling (insulin growth factor 1 (IGF1 expression, Akt/mammalian target of rapamycin (mTOR pathway, and calcineurin pathway and atrophic signaling (Akt/Forkhead box-O (FOXO pathway and myostatin expression in masseter muscle of rats treated with DEX and/or CB.Masseter muscle weight in the DEX-treated group was significantly lower than that in the Control group, as expected, but co-treatment with CB suppressed the DEX-induced masseter muscle atrophy, concomitantly with inhibition of fast-to-slow MHC isoforms transition. Activation of the Akt/mTOR pathway in masseter muscle of the DEX-treated group was significantly inhibited compared to that of the Control group, and CB suppressed this inhibition. DEX also suppressed expression of IGF1 (positive regulator of muscle growth, and CB attenuated this inhibition. Myostatin protein expression was unchanged. CB had no effect on activation of the Akt/FOXO pathway. These results indicate that CB antagonizes DEX-induced muscle atrophy and fast-to-slow MHC isoform transition via modulation of Akt/mTOR activity and IGF1 expression. CB might be a useful pharmacological agent for treatment of glucocorticoid-induced muscle atrophy.

  7. Biosynthesis and characterization of a non-repetitive polypeptide derived from silk fibroin heavy chain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Gaoqiang; Wu, Mingyang; Yi, Honggen; Wang, Jiannan, E-mail: wangjn@suda.edu.cn

    2016-02-01

    Silk fibroin heavy chain is the major protein component of Bombyx mori silk fibroin and is composed of 12 repetitive and 11 non-repetitive regions, with the non-repetitive domain consisting of a hydrophilic polypeptide chain. In order to determine the biomedical function of the non-repetitive domain or potentially use it to modify hydrophobic biomaterials, high-purity isolation is necessary. Previously, we cloned and extended a gene motif (f(1)) encoding the non-repetitive domain. Here, this motif and its multimers are inserted into a glutathione S-transferase (GST)-tagged fusion-protein expression vector. Motif f(1) and multimers f(4) and f(8) were expressed in Escherichia coli BL21 cells following isopropyl β-D-1-thiogalactopyranoside induction, purified by GST-affinity chromatography, and single bands of purified fusion proteins GST-F(1), GST-F(4), and GST-F(8), were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Target polypeptides F(1), F(4), and F(8), were cleaved clearly from the GST-fusion tag following thrombin digestion. Mass spectrometry results indicate that the molecular weights associated with fusion proteins GST-F(1), GST-F(4), and GST-F(8) are 31.5, 43.8, and 59.0 kDa, respectively, and with the cleaved polypeptides F(1), F(4), and F(8) are 4.8, 16.8, and 32.8 kDa, respectively. The F(1), F(4), and F(8) polypeptide chains are negatively charged with isoelectric points (pI) of 3.3, 3.2, and 3.0, respectively. The molecular weight and pI values of the polypeptide chains are consistent with the predicted values and the amino acid compositions similar to predicted sequences. FTIR and CD results show the molecular conformation of F(1) was mainly random coil, and more stable α-helix structure formed in longer molecular chain. - Highlights: • A non-repetitive domain and its multimers of silk fibroin were expressed by E. coli. • The corresponding target polypeptides F(1), F(4) and F(8) were cleaved clearly. • Their

  8. Binding of human beta 2-microglobulin to murine EL4 thymoma cells upregulates MHC class I heavy-chain epitopes, inhibits IL-2 secretion and induces resistance to killing by natural killer cells

    DEFF Research Database (Denmark)

    Claësson, M H; Nissen, Mogens Holst

    1994-01-01

    line (ABLS-8), X63 B-lymphoma cells and YAC cells did not bind h beta 2m. In two of the T lymphomas, EL4 and BW5147, binding of h beta 2m led to an increase in major histocompatibility complex class I (MHC-I) heavy-chain epitope expression as measured by anti-H-2K/D antibody binding and FACS analysis....... EL4 cells which had bound h beta 2m decreased their rate of constitutive IL-2 secretion and became resistant to activated natural killer (NK) cell killing. The present data suggest the binding of h beta 2m to mouse T cells leads to conformational changes of MHC-I heavy chains which influence both...

  9. Crystal structure of the anti-(carcinoembryonic antigen) single-chain Fv antibody MFE-23 and a model for antigen binding based on intermolecular contacts.

    Science.gov (United States)

    Boehm, M K; Corper, A L; Wan, T; Sohi, M K; Sutton, B J; Thornton, J D; Keep, P A; Chester, K A; Begent, R H; Perkins, S J

    2000-03-01

    MFE-23 is the first single-chain Fv antibody molecule to be used in patients and is used to target colorectal cancer through its high affinity for carcinoembryonic antigen (CEA), a cell-surface member of the immunoglobulin superfamily. MFE-23 contains an N-terminal variable heavy-chain domain joined by a (Gly(4)Ser)(3) linker to a variable light-chain (V(L)) domain (kappa chain) with an 11-residue C-terminal Myc-tag. Its crystal structure was determined at 2.4 A resolution by molecular replacement with an R(cryst) of 19.0%. Five of the six antigen-binding loops, L1, L2, L3, H1 and H2, conformed to known canonical structures. The sixth loop, H3, displayed a unique structure, with a beta-hairpin loop and a bifurcated apex characterized by a buried Thr residue. In the crystal lattice, two MFE-23 molecules were associated back-to-back in a manner not seen before. The antigen-binding site displayed a large acidic region located mainly within the H2 loop and a large hydrophobic region within the H3 loop. Even though this structure is unliganded within the crystal, there is an unusually large region of contact between the H1, H2 and H3 loops and the beta-sheet of the V(L) domain of an adjacent molecule (strands DEBA) as a result of intermolecular packing. These interactions exhibited remarkably high surface and electrostatic complementarity. Of seven MFE-23 residues predicted to make contact with antigen, five participated in these lattice contacts, and this model for antigen binding is consistent with previously reported site-specific mutagenesis of MFE-23 and its effect on CEA binding.

  10. In vitro and in vivo properties of human/mouse chimeric monoclonal antibody specific for common acute lymphocytic leukemia antigen

    International Nuclear Information System (INIS)

    Saga, T.; Endo, K.; Koizumi, M.; Kawamura, Y.; Watanabe, Y.; Konishi, J.; Ueda, R.; Nishimura, Y.; Yokoyama, M.; Watanabe, T.

    1990-01-01

    A human/mouse chimeric monoclonal antibody specific for a common acute lymphocytic leukemia antigen was efficiently obtained by ligating human heavy-chain enhancer element to the chimeric heavy- and light-chain genes. Cell binding and competitive inhibition assays of both radioiodine and indium-111- (111In) labeled chimeric antibodies demonstrated in vitro immunoreactivity identical with that of the parental murine monoclonal antibodies. The biodistribution of the radiolabeled chimeric antibody in tumor-bearing nude mice was similar to that of the parental murine antibody. Tumor accumulation of radioiodinated parental and chimeric antibodies was lower than that of 111 In-labeled antibodies, probably because of dehalogenation of the radioiodinated antibodies. Indium-111-labeled chimeric antibody clearly visualized xenografted tumor. These results suggest that a human/mouse chimeric antibody can be labeled with 111 In and radioiodine without the loss of its immunoreactivity, and that chimeric antibody localizes in vivo in the same way as the parental murine antibody

  11. Isolation and characterization of anti c-met single chain fragment variable (scFv) antibodies.

    Science.gov (United States)

    Qamsari, Elmira Safaie; Sharifzadeh, Zahra; Bagheri, Salman; Riazi-Rad, Farhad; Younesi, Vahid; Abolhassani, Mohsen; Ghaderi, Sepideh Safaei; Baradaran, Behzad; Somi, Mohammad Hossein; Yousefi, Mehdi

    2017-12-01

    The receptor tyrosine kinase (RTK) Met is the cell surface receptor for hepatocyte growth factor (HGF) involved in invasive growth programs during embryogenesis and tumorgenesis. There is compelling evidence suggesting important roles for c-Met in colorectal cancer proliferation, migration, invasion, angiogenesis, and survival. Hence, a molecular inhibitor of an extracellular domain of c-Met receptor that blocks c-Met-cell surface interactions could be of great thera-peutic importance. In an attempt to develop molecular inhibitors of c-Met, single chain variable fragment (scFv) phage display libraries Tomlinson I + J against a specific synthetic oligopeptide from the extracellular domain of c-Met receptor were screened; selected scFv were then characterized using various immune techniques. Three c-Met specific scFv (ES1, ES2, and ES3) were selected following five rounds of panning procedures. The scFv showed specific binding to c-Met receptor, and significantly inhibited proliferation responses of a human colorectal carcinoma cell line (HCT-116). Moreover, anti- apoptotic effects of selected scFv antibodies on the HCT-116 cell line were also evaluated using Annexin V/PI assays. The results demonstrated rates of apoptotic cell death of 46.0, 25.5, and 37.8% among these cells were induced by use of ES1, ES2, and ES3, respectively. The results demonstrated ability to successfully isolate/char-acterize specific c-Met scFv that could ultimately have a great therapeutic potential in immuno-therapies against (colorectal) cancers.

  12. Characterization of a specific monoclonal antibody against immunoglobulin light kappa/L1 chain in olive flounder (Paralichthys olivaceus)

    DEFF Research Database (Denmark)

    Kim, Young Kyu; Lee, Jung Seok; Jung, Jae Wook

    2017-01-01

    Immunoglobulins (Ig) are heterodimeric proteins that play critical roles in the adaptive immune system of vertebrates. Because of their plasticity, teleostean Igs are more diverse, and thus do not conform to mammalian classifications. Because of this, mammalian-based Ig cell markers cannot be used...... successfully to study immune responses in fish. There is therefore a need to produce Ig-specific cell markers for fish. Here, we attempted to identify the specific isotype detected by an Ig light chain-specific monoclonal antibody (anti-olive flounder IgL-mAb: M7C3-4) that we had previously produced [11......]. Three newly identified sequences of the Ig light chain from olive flounder were classified according to their isotypes. Subsequent analyses revealed that M7C3-4 was able to specifically detect lymphocytes expressing one of the κ chains (Igκ-a) in olive flounder. Interestingly, Igκ-a+ B cells were more...

  13. Generation and characterisation of murine monoclonal antibodies specific for cervine immunoglobulin light chain, IgM and IgG

    International Nuclear Information System (INIS)

    Hibma, M.; Griffin, J.F.T.

    1992-01-01

    Monoclonal antibodies (mAb) which react with cervine immunoglobulin (Ig) light chain, IgM and IgG were produced using conventional cell fusion technology. Hybridoma supernatants were initially screened for specificity against cervine Ig using an enzyme-linked immunosorbent assay (ELISA). The specificity of supernatants against size-fractionated cervine Ig was further determined. Supernatants were characterised using western blotting and autoradiographic techniques. The mAb OU1G, OU2G and OU3G were specific for cervine gamma-chain of IgG, whereas OU1L was specific for light chain of Ig. A further mAb (OU1M) bound IgM and not IgG. These mAb were found to have varying cross-reactivity against Ig from other species

  14. Locus-specific detection of HLA-DQ and -DR antigens by antibodies against synthetic N-terminal octapeptides of the beta chain

    DEFF Research Database (Denmark)

    Deufel, T; Grove, A; Kofod, Hans

    1985-01-01

    Antibodies against synthetic peptides representing the class-II antigen HLA-DR and -DQ beta chain N-terminal sequences were prepared in rabbits. The two octapeptides only share two amino acids and enzyme-linked immuno-assays showed the antisera only to bind to its own antigen. Both peptide antisera...... chains of HLA-DR and -DQ have been prepared by the preparation by the production of antibodies against the N-terminal sequences of each polypeptide....

  15. Baculovirus display of single chain antibody (scFv using a novel signal peptide

    Directory of Open Access Journals (Sweden)

    Gonzalez Gaëlle

    2010-11-01

    Full Text Available Abstract Background Cells permissive to virus can become refractory to viral replication upon intracellular expression of single chain fragment variable (scFv antibodies directed towards viral structural or regulatory proteins, or virus-coded enzymes. For example, an intrabody derived from MH-SVM33, a monoclonal antibody against a conserved C-terminal epitope of the HIV-1 matrix protein (MAp17, was found to exert an inhibitory effect on HIV-1 replication. Results Two versions of MH-SVM33-derived scFv were constructed in recombinant baculoviruses (BVs and expressed in BV-infected Sf9 cells, N-myristoylation-competent scFvG2/p17 and N-myristoylation-incompetent scFvE2/p17 protein, both carrying a C-terminal HA tag. ScFvG2/p17 expression resulted in an insoluble, membrane-associated protein, whereas scFvE2/p17 was recovered in both soluble and membrane-incorporated forms. When coexpressed with the HIV-1 Pr55Gag precursor, scFvG2/p17 and scFvE2/p17 did not show any detectable negative effect on virus-like particle (VLP assembly and egress, and both failed to be encapsidated in VLP. However, soluble scFvE2/p17 isolated from Sf9 cell lysates was capable of binding to its specific antigen, in the form of a synthetic p17 peptide or as Gag polyprotein-embedded epitope. Significant amounts of scFvE2/p17 were released in the extracellular medium of BV-infected cells in high-molecular weight, pelletable form. This particulate form corresponded to BV particles displaying scFvE2/p17 molecules, inserted into the BV envelope via the scFv N-terminal region. The BV-displayed scFvE2/p17 molecules were found to be immunologically functional, as they reacted with the C-terminal epitope of MAp17. Fusion of the N-terminal 18 amino acid residues from the scFvE2/p17 sequence (N18E2 to another scFv recognizing CD147 (scFv-M6-1B9 conferred the property of BV-display to the resulting chimeric scFv-N18E2/M6. Conclusion Expression of scFvE2/p17 in insect cells using a BV

  16. Single Chain Fv Constructs of Anti-Ganglioside GD2 Antibodies for Radioimaging and Radioimmunotherapy

    International Nuclear Information System (INIS)

    Cheung, Nai-Kong

    2003-01-01

    because of its broad and usually homogeneous distribution in human solid tumors, and most importantly, their absence on cell membranes of normal human tissues. In separate experiments, we have shown that T-cells transduced with the herpes simplex viral thymidine kinase (HSV-tk) gene can be radiolabeled with 131 I-FIAU to a safe nuclear radiation dose. Using a dicistronic construct we are inserting chimeric immune receptor plus HSV-tk into T-cells to allow such their trafficking to be radioactively monitored. We plan to study the role of cytokines, chemoreceptors and CD4 helper T-cells in recruiting CD8+ transduced T-cells to the tumor site. These studies should provide us with an adoptive cell therapy approach to target cytotoxicity to human tumors, and a lymphocyte tracking tool to study delivery to the tumor sites, to determine if they proliferate locally and/or recirculate. Such pharmacologic information is crucial for optimizing gene-modified T-cells in future clinical trials. Single chain FV constructs of anti-ganglioside GD2 antibodies for radioimaging

  17. Light-chain residue 95 is critical for antigen binding and multispecificity of monoclonal antibody G2.

    Science.gov (United States)

    Usui, Daiki; Inaba, Satomi; Kamatari, Yuji O; Ishiguro, Naotaka; Oda, Masayuki

    2017-09-02

    The monoclonal antibody, G2, specifically binds to the immunogen peptide derived from the chicken prion protein, Pep18mer, and two chicken proteins derived peptides, Pep8 and Pep395; G2 binds with equal affinity to Pep18mer. The amino acid sequences of the three peptides are completely different, and so the recognition mechanism of G2 is unique and interesting. We generated a single-chain Fv (scFv) antibody of G2, and demonstrated its correct folding with an antigen binding function similar to intact G2 antibody. We also generated a Pro containing mutant of G2 scFv at residue 95 of the light chain, and analyzed its antigen binding using a surface plasmon biosensor. The mutant lost its binding ability to Pep18mer, but remained those to Pep8 and Pep395. The results clearly indicate residue 95 as being critical for multispecific antigen binding of G2 at the site generated from the junctional diversity introduced at the joints between the V and J gene segments. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Interaction of thyroid state and denervation on skeletal myosin heavy chain expression

    Science.gov (United States)

    Haddad, F.; Arnold, C.; Zeng, M.; Baldwin, K.

    1997-01-01

    The goal of this study was to examine the effects of altered thyroid state and denervation (Den) on skeletal myosin heavy chain (MHC) expression in the plantaris and soleus muscles. Rats were subjected to unilateral denervation (Den) and randomly assigned to one of three groups: (1) euthyroid; (2) hyperthyroid; (3) and hypothyroid. Denervation caused severe muscle atrophy and muscle-type specific MHC transformation. Denervation transformed the soleus to a faster muscle, and its effects required the presence of circulating thyroid hormone. In contrast, denervation transformed the plantaris to a slower muscle independently of thyroid state. Furthermore, thyroid hormone effects did not depend upon innervation status in the soleus, while they required the presence of the nerve in the plantaris. Collectively, these findings suggest that both thyroid hormone and intact nerve (a) differentially affect MHC transformations in fast and slow muscle; and (b) are important factors in regulating the optimal expression of both type I and IIB MHC genes. This research suggests that for patients with nerve damage and/or paralysis, both muscle mass and biochemical properties can also be affected by the thyroid state.

  19. RUNX1-induced silencing of non-muscle myosin heavy chain IIB contributes to megakaryocyte polyploidization.

    Science.gov (United States)

    Lordier, Larissa; Bluteau, Dominique; Jalil, Abdelali; Legrand, Céline; Pan, Jiajia; Rameau, Philippe; Jouni, Dima; Bluteau, Olivier; Mercher, Thomas; Leon, Catherine; Gachet, Christian; Debili, Najet; Vainchenker, William; Raslova, Hana; Chang, Yunhua

    2012-03-06

    Megakaryocytes are unique mammalian cells that undergo polyploidization (endomitosis) during differentiation, leading to an increase in cell size and protein production that precedes platelet production. Recent evidence demonstrates that endomitosis is a consequence of a late failure in cytokinesis associated with a contractile ring defect. Here we show that the non-muscle myosin IIB heavy chain (MYH10) is expressed in immature megakaryocytes and specifically localizes in the contractile ring. MYH10 downmodulation by short hairpin RNA increases polyploidization by inhibiting the return of 4N cells to 2N, but other regulators, such as of the G1/S transition, might regulate further polyploidization of the 4N cells. Conversely, re-expression of MYH10 in the megakaryocytes prevents polyploidization and the transition of 2N to 4N cells. During polyploidization, MYH10 expression is repressed by the major megakaryocyte transcription factor RUNX1. Thus, RUNX1-mediated silencing of MYH10 is required for the switch from mitosis to endomitosis, linking polyploidization with megakaryocyte differentiation.

  20. A Mouse Neurodegenerative Dynein Heavy Chain Mutation Alters Dynein Motility and Localization in Neurospora crassa

    Science.gov (United States)

    Sivagurunathan, Senthilkumar; Schnittker, Robert R.; Nandini, Swaran; Plamann, Michael D.; King, Stephen J.

    2013-01-01

    Cytoplasmic dynein is responsible for the transport and delivery of cargoes in organisms ranging from humans to fungi. Dysfunction of dynein motor machinery due to mutations in dynein or its activating complex dynactin can result in one of several neurological diseases in mammals. The mouse Legs at odd angles (Loa) mutation in the tail domain of the dynein heavy chain has been shown to lead to progressive neurodegeneration in mice. The mechanism by which the Loa mutation affects dynein function is just beginning to be understood. In this work, we generated the dynein tail mutation observed in Loa mice into the Neurospora crassa genome and utilized cell biological and complementing biochemical approaches to characterize how that tail mutation affected dynein function. We determined that the Loa mutation exhibits several subtle defects upon dynein function in N. crassa that were not seen in mice, including alterations in dynein localization, impaired velocity of vesicle transport, and in the biochemical properties of purified motors. Our work provides new information on the role of the tail domain on dynein function and points out areas of future research that will be of interest to pursue in mammalian systems. PMID:22991199

  1. Prognostic value of serum heavy/light chain ratios in patients with POEMS syndrome.

    Science.gov (United States)

    Wang, Chen; Su, Wei; Cai, Qian-Qian; Cai, Hao; Ji, Wei; Di, Qian; Duan, Ming-Hui; Cao, Xin-Xin; Zhou, Dao-Bin; Li, Jian

    2016-07-01

    POEMS syndrome is a rare plasma cell dyscrasia. Serum concentrations of the monoclonal protein in this disorder are typically low, and inapplicable to monitor disease activity in most cases, resulting in limited practical and prognostic values. Novel immunoassays measuring isotype-specific heavy/light chain (HLC) pairs showed its utility in disease monitoring and outcome prediction in several plasma cell dyscrasias. We report results of HLC measurements in 90 patients with POEMS syndrome. Sixty-six patients (73%; 95% confidence interval, 63-82%) had an abnormal HLC ratio at baseline. It could stratify the risk of disease relapse and was strongly associated with worse progression-free survival in a multivariate analysis (P = 0.021; hazard ratio [HR] 6.89, 95% CI 1.34-35.43). After therapy, HLC ratios improved, with 43 patients (48%) remaining abnormal. The post-therapeutic HLC ratio, if abnormal, also remained as an independent prognostic factor associated with worse progression-free survival (P = 0.019; HR 4.30, 95% CI 1.27-14.56). These results suggest the prognostic utility of HLC ratios in clinical management of POEMS patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Time course of myosin heavy chain transitions in neonatal rats: importance of innervation and thyroid state

    Science.gov (United States)

    Adams, G. R.; McCue, S. A.; Zeng, M.; Baldwin, K. M.

    1999-01-01

    During the postnatal period, rat limb muscles adapt to weight bearing via the replacement of embryonic (Emb) and neonatal (Neo) myosin heavy chains (MHCs) by the adult isoforms. Our aim was to characterize this transition in terms of the six MHC isoforms expressed in skeletal muscle and to determine the importance of innervation and thyroid hormone status on the attainment of the adult MHC phenotype. Neonatal rats were made hypothyroid via propylthiouracil (PTU) injection. In normal and PTU subgroups, leg muscles were unilaterally denervated at 15 days of age. The MHC profiles of plantaris (PLN) and soleus (Sol) muscles were determined at 7, 14, 23, and 30 days postpartum. At day 7, the Sol MHC profile was 55% type I, 30% Emb, and 10% Neo; in the PLN, the pattern was 60% Neo and 25% Emb. By day 30 the Sol and PLN had essentially attained an adult MHC profile in the controls. PTU augmented slow MHC expression in the Sol, whereas in the PLN it markedly repressed IIb MHC by retaining neonatal MHC expression. Denervation blunted the upregulation of IIb in the PLN and of Type I in the Sol and shifted the pattern to greater expression of IIa and IIx MHCs in both muscles. In contrast to previous observations, these findings collectively suggest that both an intact thyroid and innervation state are obligatory for the attainment of the adult MHC phenotype, particularly in fast-twitch muscles.

  3. Single-fiber myosin heavy chain polymorphism during postnatal development: modulation by hypothyroidism

    Science.gov (United States)

    di Maso, N. A.; Caiozzo, V. J.; Baldwin, K. M.

    2000-01-01

    The primary objective of this study was to follow the developmental time course of myosin heavy chain (MHC) isoform transitions in single fibers of the rodent plantaris muscle. Hypothyroidism was used in conjunction with single-fiber analyses to better describe a possible linkage between the neonatal and fast type IIB MHC isoforms during development. In contrast to the general concept that developmental MHC isoform transitions give rise to muscle fibers that express only a single MHC isoform, the single-fiber analyses revealed a very high degree of MHC polymorphism throughout postnatal development. In the adult state, MHC polymorphism was so pervasive that the rodent plantaris muscles contained approximately 12-15 different pools of fibers (i.e., fiber types). The degree of polymorphism observed at the single-fiber level made it difficult to determine specific developmental schemes analogous to those observed previously for the rodent soleus muscle. However, hypothyroidism was useful in that it confirmed a possible link between the developmental regulation of the neonatal and fast type IIB MHC isoforms.

  4. Clathrin heavy chain 1 is required for spindle assembly and chromosome congression in mouse oocytes.

    Science.gov (United States)

    Zhao, Jie; Wang, Lu; Zhou, Hong-Xia; Liu, Li; Lu, Angeleem; Li, Guang-Peng; Schatten, Heide; Liang, Cheng-Guang

    2013-10-01

    Clathrin heavy chain 1 (CLTC) has been considered a “moonlighting protein” which acts in membrane trafficking during interphase and in stabilizing spindle fibers during mitosis. However, its roles in meiosis, especially in mammalian oocyte maturation, remain unclear. This study investigated CLTC expression and function in spindle formation and chromosome congression during mouse oocyte meiotic maturation. Our results showed that the expression level of CLTC increased after germinal vesicle breakdown (GVBD) and peaked in the M phase. Immunostaining results showed CLTC distribution throughout the cytoplasm in a cell cycle-dependent manner. Appearance and disappearance of CLTC along with β-tubulin (TUBB) could be observed during spindle dynamic changes. To explore the relationship between CLTC and microtubule dynamics, oocytes at metaphase were treated with taxol or nocodazole. CLTC colocalized with TUBB at the enlarged spindle and with cytoplasmic asters after taxol treatment; it disassembled and distributed into the cytoplasm along with TUBB after nocodazole treatment. Disruption of CLTC function using stealth siRNA caused a decreased first polar body extrusion rate and extensive spindle formation and chromosome congression defects. Taken together, these results show that CLTC plays an important role in spindle assembly and chromosome congression through a microtubule correlation mechanism during mouse oocyte maturation.

  5. Phosphoneurofilament heavy chain and N-glycomics from the cerebrospinal fluid in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Gonçalves, Margarida; Tillack, Linda; de Carvalho, Mamede; Pinto, Susana; Conradt, Harald S; Costa, Júlia

    2015-01-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease of the motor neuron for which no clinically validated biomarkers have been identified. We have quantified by ELISA the biomarker phosphoneurofilament heavy chain (pNFH) in the cerebrospinal fluid (CSF) of ALS patients (n=29) and age-matched control patients with other diseases (n=19) by ELISA. Furthermore, we compared protein N-glycosylation of the CSF in ALS patients and controls, by applying a glycomics approach based on liquid chromatography and mass spectrometry. pNFH levels were significantly higher in ALS patients in comparison with controls (P<0.0001) in particular in fast progressors. The N-glycans found in the CSF were predominantly complex diantennary with sialic acid in α2,3- and α2,6-linkage, and bisecting N-acetylglucosamine-containing structures as well as peripherally fucosylated structures were found. As compared with controls the ALS group had a significant increase of a peak composed of the monosialylated diantennary glycans A2G2S(6)1 and FA2G2S(3)1 (P=0.0348). Our results underscore the value of pNFH as a biomarker in ALS. In addition, we identified a variation of the N-glycosylation pattern in ALS, suggesting that this change should be explored in future studies as potential biomarker. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Iron Deposition and Ferritin Heavy Chain (Fth Localization in Rodent Teeth

    Directory of Open Access Journals (Sweden)

    Wen Xin

    2013-01-01

    Full Text Available Abstract Background An iron rich layer on the labial surface is characteristic of the enamel of rodent incisors. In order to address a role for iron content in continuously growing incisors during odontogenesis, we studied iron deposition patterns in enamel and dentine using Perls’ blue staining and ferritin heavy chain (Fth immunolocalization. Fth expression is regulated by iron level; therefore its localization can be used as a sensitive indicator for iron deposition. Results Sagittal sections of 4-week old rat incisors showed a gradual increase in iron level in the enamel organ from secretory to maturation stages. In addition, iron was detected in ameloblasts of erupting third molars of 4-week old rats, suggesting iron plays a role in both incisor and molar development. In odontoblasts, the presence of iron was demonstrated, and this is consistent with iron’s role in collagen synthesis. Using postnatal 3-, 6-, 9-day old mice, the spatial and temporal expression of Fth in tooth development again indicated the presence of iron in mature ameloblasts and odontoblasts. Conclusions While these data do not explain what functional role iron has in tooth formation, it does highlight a significant molecular activity associated with the formation of the rodent dentition.

  7. Combination of neurofilament heavy chain and complement c3 as CSF biomarkers for ALS

    Science.gov (United States)

    Ganesalingam, Jeban; An, Jiyan; Shaw, Christopher E; Shaw, Gerry; Lacomis, David; Bowser, Robert

    2011-01-01

    Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and ultimately fatal neurodegenerative disease with an average survival of 3 years from symptom onset. Rapid and conclusive early diagnosis is essential if interventions with disease-modifying therapies are to be successful. Cytoskeletal modification and inflammation are known to occur during the pathogenesis of ALS. We measured levels of cytoskeletal proteins and inflammatory markers in the cerebrospinal fluid (CSF) of ALS, disease controls and healthy subjects. We determined threshold values for each protein that provided the optimal sensitivity and specificity for ALS within a training set, as determined by receiver operating characteristic (ROC) analysis. Interestingly, the optimal assay was a ratio of the levels for phosphorylated neurofilament heavy chain and complement C3 (pNFH/C3). We next applied this assay to a separate test set of CSF samples to verify our results. Overall, the predictive pNFH/C3 ratio identified ALS with 87.3% sensitivity and 94.6% specificity in a total of 71 ALS subjects, 52 disease control subjects and 40 healthy subjects. In addition, the level of CSF pNFH correlated with survival of ALS patients. We also detected increased pNFH in the plasma of ALS patients and observed a correlation between CSF and plasma pNFH levels within the same subjects. These findings support large-scale prospective biomarker studies to determine the clinical utility of diagnostic and prognostic signatures in ALS. PMID:21418221

  8. Identification of tumor associated single-chain Fv by panning and screening antibody phage library using tumor cells

    Science.gov (United States)

    Nie, Yong-Zhan; He, Feng-Tian; Li, Zhi-Kui; Wu, Kai-Chun; Cao, Yun-Xin; Chen, Bao-Jun; Fan, Dai-Ming

    2002-01-01

    AIM: To study the feasibility of panning and screening phage-displaying recombinant single-chain variable fragment (ScFv) of anti-tumor monoclonal antibodies for fixed whole cells as the carriers of mAb-binding antigens. METHODS: The recombinant phage displaying libraries for anti-colorectal tumor mAb MC3Ab, MC5Ab and anti-gastric tumor mAb MGD1 was constructed. Panning and screening were carried out by means of modified fixation of colorectal and gastric tumor cells expressed the mAb-binding antigens. Concordance of binding specificity to tumor cells between phage clones and parent antibodies was analyzed. The phage of positive clones was identified with competitive ELISA, and infected by E. coli HB2151 to express soluble ScFv. RESULTS: The ratio of positive clones to MC3-ScF-MC5-ScFv and MGD1-ScFv were 60%, 24% and 30%. MC3-ScFv had Mr 32000 confirmed by Western blot. The specificity to antigen had no difference between 4 positive recombinant phage antibodies and MC3Ab. CONCLUSION: The modified process of fixing whole tumor cells is efficient, convenient and feasible to pan and screen the phage-displaying ScFv of anti-tumor monoclonal antibodies. PMID:12174367

  9. Arg9 facilitates the translocation and downstream signal inhibition of an anti-HER2 single chain antibody

    Directory of Open Access Journals (Sweden)

    Hu Yi

    2012-07-01

    Full Text Available Abstract Background HER2 plays a critical role in the pathogenesis of many cancers and is linked to poor prognosis or cancer metastases. Monoclonal antibodies, such as Herceptin against HER2-overexpressing cancers, have showed satisfactory clinical therapeutic effect. However, they have difficulty to surmount obstacles to enter cells or blood–brain barrier. Results In this study, a cell-penetrating peptide Arg9 was linked to the C-terminus of anti-HER2 single chain antibody (MIL5scFv. Flow cytometry, confocal microscopy and electron microscopy analysis all revealed that Arg9 peptide facilitated the penetration of MIL5scFv into HER2-negative cell line NIH3T3 and orientate in mitochondria. More interestingly, Western blot assay showed the potential enhanced bioactivity of MIL5scFv-Arg9 in HER2+ cell line SKOV3, indicating that Arg9 could help large molecules (e.g. antibody to penetrate into cells and therefore enhance its anti-neoplastic function. Conclusions Our work represented an attractive by preliminary strategy to enhance the therapeutic effect of existing antibodies by entering cells easier, or more desirable, surmounting the physical barriers, especially in hard-to-reach cancers such as brain metastases cases.

  10. Selection of diethylstilbestrol-specific single-chain antibodies from a non-immunized mouse ribosome display library.

    Directory of Open Access Journals (Sweden)

    Yanan Sun

    Full Text Available Single chain variable fragments (scFvs against diethylstilbestrol (DES were selected from the splenocytes of non-immunized mice by ribosome display technology. A naive library was constructed and engineered to allow in vitro transcription and translation using an E. coli lysate system. Alternating selection in solution and immobilization in microtiter wells was used to pan mRNA-ribosome-antibody (ARM complexes. After seven rounds of ribosome display, the expression vector pTIG-TRX containing the selected specific scFv DNAs were transformed into Escherichia coli BL21 (DE3 for expression. Twenty-six positive clones were screened and five clones had high antibody affinity and specificity to DES as evidenced by indirect competitive ELISA. Sequence analysis showed that these five DES-specific scFvs had different amino acid sequences, but the CDRs were highly similar. Surface plasmon resonance (SPR analysis was used to determine binding kinetics of one clone (30-1. The measured K(D was 3.79 µM. These results indicate that ribosome display technology can be used to efficiently isolate hapten-specific antibody (Ab fragments from a naive library; this study provides a methodological framework for the development of novel immunoassays for multiple environmental pollutants with low molecular weight detection using recombinant antibodies.

  11. A novel heavy domain antibody library with functionally optimized complementarity determining regions.

    Directory of Open Access Journals (Sweden)

    Ole Aalund Mandrup

    Full Text Available Today a number of synthetic antibody libraries of different formats have been created and used for the selection of a large number of recombinant antibodies. One of the determining factors for successful isolation of recombinant antibodies from libraries lies in the quality of the libraries i.e. the number of correctly folded, functional antibodies contained in the library. Here, we describe the construction of a novel, high quality, synthetic single domain antibody library dubbed Predator. The library is based on the HEL4 domain antibody with the addition of recently reported mutations concerning the amino acid composition at positions critical for the folding characteristics and aggregation propensities of domain antibodies. As a unique feature, the CDR3 of the library was designed to mimic the natural human immune response by designating amino acids known to be prevalent in functional antibodies to the diversity in CDR3. CDR randomizations were performed using trinucleotide synthesis to avoid the presence of stop codons. Furthermore a novel cycle free elongation method was used for the conversion of the synthesized single stranded DNA containing the randomized CDRs into double stranded DNA of the library. In addition a modular approach has been adopted for the scaffold in which each CDR region is flanked by unique restrictions sites, allowing easy affinity maturation of selected clones by CDR shuffling. To validate the quality of the library, one round phage display selections were performed on purified antigens and highly complex antigen mixtures such as cultured eukaryotic cells resulting in several specific binders. The further characterization of some of the selected clones, however, indicates a reduction in thermodynamic stability caused by the inclusion the additional mutations to the HEL4 scaffold.

  12. Comparison of new ELISA method with established SDS-PAGE method for determination of muscle myosin heavy chain isoforms

    Czech Academy of Sciences Publication Activity Database

    Říčný, Jan; Soukup, Tomáš

    2011-01-01

    Roč. 60, č. 6 (2011), s. 899-904 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/08/0256 Grant - others:EC(XE) LSH-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscle fiber types * myosin heavy chains * SDS - PAGE * immunoreactions * thyroid hormones * ELISA Subject RIV: EA - Cell Biology Impact factor: 1.555, year: 2011

  13. Construction and characterization of the alpha form of a cardiac myosin heavy chain cDNA clone and its developmental expression in the Syrian hamster.

    OpenAIRE

    Liew, C C; Jandreski, M A

    1986-01-01

    A cDNA clone, pVHC1, was isolated from a Syrian hamster heart cDNA library and was compared to the rat alpha (pCMHC21) and beta (pCMHC5) ventricular myosin heavy chain cDNA clones. The DNA sequence and amino acid sequence deducted from the DNA show more homology with pCMHC21 than pCMHC5. This indicates that pVHC1 is an alpha ventricular myosin heavy chain cDNA clone. However, even though pVHC1 shows a high degree of nucleotide and amino acid conservation with the rat myosin heavy chain sequen...

  14. Ku70 is required for late B cell development and immunoglobulin heavy chain class switching.

    Science.gov (United States)

    Manis, J P; Gu, Y; Lansford, R; Sonoda, E; Ferrini, R; Davidson, L; Rajewsky, K; Alt, F W

    1998-06-15

    Immunoglobulin (Ig) heavy chain (HC) class switch recombination (CSR) is a late B cell process that involves intrachromosomal DNA rearrangement. Ku70 and Ku80 form a DNA end-binding complex required for DNA double strand break repair and V(D)J recombination. Ku70(-/-) (K70T) mice, like recombination activating gene (RAG)-1- or RAG-2-deficient (R1T or R2T) mice, have impaired B and T cell development at an early progenitor stage, which is thought to result at least in part from defective V(D)J recombination (Gu, Y., K.J. Seidl, G.A. Rathbun, C. Zhu, J.P. Manis, N. van der Stoep, L. Davidson, H.L. Cheng, J.M. Sekiguchi, K. Frank, et al. 1997. Immunity. 7:653-665; Ouyang, H., A. Nussenzweig, A. Kurimasa, V.C. Soares, X. Li, C. Cordon-Cardo, W. Li, N. Cheong, M. Nussenzweig, G. Iliakis, et al. 1997. J. Exp. Med. 186:921-929). Therefore, to examine the potential role of Ku70 in CSR, we generated K70T mice that carry a germline Ig HC locus in which the JH region was replaced with a functionally rearranged VH(D)JH and Ig lambda light chain transgene (referred to as K70T/HL mice). Previously, we have shown that B cells from R1T or R2T mice carrying these rearranged Ig genes (R1T/HL or R2T/HL mice) can undergo CSR to IgG isotypes (Lansford, R., J. Manis, E. Sonoda, K. Rajewsky, and F. Alt. 1998. Int. Immunol. 10:325-332). K70T/HL mice had significant numbers of peripheral surface IgM+ B cells, which generated serum IgM levels similar to those of R2T/HL mice. However, in contrast to R2T/HL mice, K70T/HL mice had no detectable serum IgG isotypes. In vitro culture of K70T/HL B cells with agents that induce CSR in normal or R2T/HL B cells did lead to the induction of germline CH transcripts, indicating that initial signaling pathways for CSR were intact in K70T/HL cells. However, treatment with such agents did not lead to detectable CSR by K70T/HL B cells, and instead, led to cell death within 72 h. We conclude that Ku70 is required for the generation of B cells that have

  15. Large-scale chromatin remodeling at the immunoglobulin heavy chain locus: a paradigm for multigene regulation.

    Science.gov (United States)

    Bolland, Daniel J; Wood, Andrew L; Corcoran, Anne E

    2009-01-01

    V(D)J recombination in lymphocytes is the cutting and pasting together of antigen receptor genes in cis to generate the enormous variety of coding sequences required to produce diverse antigen receptor proteins. It is the key role of the adaptive immune response, which must potentially combat millions of different foreign antigens. Most antigen receptor loci have evolved to be extremely large and contain multiple individual V, D and J genes. The immunoglobulin heavy chain (Igh) and immunoglobulin kappa light chain (Igk) loci are the largest multigene loci in the mammalian genome and V(D)J recombination is one of the most complicated genetic processes in the nucleus. The challenge for the appropriate lymphocyte is one of macro-management-to make all of the antigen receptor genes in a particular locus available for recombination at the appropriate developmental time-point. Conversely, these large loci must be kept closed in lymphocytes in which they do not normally recombine, to guard against genomic instability generated by the DNA double strand breaks inherent to the V(D)J recombination process. To manage all of these demanding criteria, V(D)J recombination is regulated at numerous levels. It is restricted to lymphocytes since the Rag genes which control the DNA double-strand break step of recombination are only expressed in these cells. Within the lymphocyte lineage, immunoglobulin recombination is restricted to B-lymphocytes and TCR recombination to T-lymphocytes by regulation of locus accessibility, which occurs at multiple levels. Accessibility of recombination signal sequences (RSSs) flanking individual V, D and J genes at the nucleosomal level is the key micro-management mechanism, which is discussed in greater detail in other chapters. This chapter will explore how the antigen receptor loci are regulated as a whole, focussing on the Igh locus as a paradigm for the mechanisms involved. Numerous recent studies have begun to unravel the complex and

  16. Anti-DNA antibodies: Sequencing, cloning, and expression

    Energy Technology Data Exchange (ETDEWEB)

    Barry, M.M.

    1992-01-01

    To gain some insight into the mechanism of systemic lupus erythematosus, and the interactions involved in proteins binding to DNA four anti-DNA antibodies have been investigated. Two of the antibodies, Hed 10 and Jel 242, have previously been prepared from female NZB/NZW mice which develop an autoimmune disease resembling human SLE. The remaining two antibodies, Jel 72 and Jel 318, have previously been produced via immunization of C57BL/6 mice. The isotypes of the four antibodies investigated in this thesis were determined by an enzyme-linked-immunosorbent assay. All four antibodies contained [kappa] light chains and [gamma]2a heavy chains except Jel 318 which contains a [gamma]2b heavy chain. The complete variable regions of the heavy and light chains of these four antibodies were sequenced from their respective mRNAs. The gene segments and variable gene families expressed in each antibody were identified. Analysis of the genes used in the autoimmune anti-DNA antibodies and those produced by immunization indicated no obvious differences to account for their different origins. Examination of the amino acid residues present in the complementary-determining regions of these four antibodies indicates a preference for aromatic amino acids. Jel 72 and Jel 242 contain three arginine residues in the third complementary-determining region. A single-chain Fv and the variable region of the heavy chain of Hed 10 were expressed in Escherichia coli. Expression resulted in the production of a 26,000 M[sub r] protein and a 15,000 M[sub r] protein. An immunoblot indicated that the 26,000 M[sub r] protein was the Fv for Hed 10, while the 15,000 M[sub r] protein was shown to bind poly (dT). The contribution of the heavy chain to DNA binding was assessed.

  17. Biodistribution and tumor imaging of an anti-CEA single-chain antibody-albumin fusion protein

    International Nuclear Information System (INIS)

    Yazaki, Paul J.; Kassa, Thewodros; Cheung, Chia-wei; Crow, Desiree M.; Sherman, Mark A.; Bading, James R.; Anderson, Anne-Line J.; Colcher, David; Raubitschek, Andrew

    2008-01-01

    Albumin fusion proteins have demonstrated the ability to prolong the in vivo half-life of small therapeutic proteins/peptides in the circulation and thereby potentially increase their therapeutic efficacy. To evaluate if this format can be employed for antibody-based imaging, an anticarcinoembryonic antigen (CEA) single-chain antibody(scFv)-albumin fusion protein was designed, expressed and radiolabeled for biodistribution and imaging studies in athymic mice bearing human colorectal carcinoma LS-174T xenografts. The [ 125 I]-T84.66 fusion protein demonstrated rapid tumor uptake of 12.3% injected dose per gram (ID/g) at 4 h that reached a plateau of 22.7% ID/g by 18 h. This was a dramatic increase in tumor uptake compared to 4.9% ID/g for the scFv alone. The radiometal [ 111 In]-labeled version resulted in higher tumor uptake, 37.2% ID/g at 18 h, which persisted at the tumor site with tumor: blood ratios reaching 18:1 and with normal tissues showing limited uptake. Based on these favorable imaging properties, a pilot [ 64 Cu]-positron emission tomography imaging study was performed with promising results. The anti-CEA T84.66 scFv-albumin fusion protein demonstrates highly specific tumor uptake that is comparable to cognate recombinant antibody fragments. The radiometal-labeled version, which shows lower normal tissue accumulation than these recombinant antibodies, provides a promising and novel platform for antibody-based imaging agents

  18. Role of kinesin heavy chain in Crumbs localization along the rhabdomere elongation in Drosophila photoreceptor.

    Directory of Open Access Journals (Sweden)

    Garrett P League

    Full Text Available BACKGROUND: Crumbs (Crb, a cell polarity gene, has been shown to provide a positional cue for the extension of the apical membrane domain, adherens junction (AJ, and rhabdomere along the growing proximal-distal axis during Drosophila photoreceptor morphogenesis. In developing Drosophila photoreceptors, a stabilized microtubule structure was discovered and its presence was linked to polarity protein localization. It was therefore hypothesized that the microtubules may provide trafficking routes for the polarity proteins during photoreceptor morphogenesis. This study has examined whether Kinesin heavy chain (Khc, a subunit of the microtubule-based motor Kinesin-1, is essential in polarity protein localization in developing photoreceptors. METHODOLOGY/PRINCIPAL FINDINGS: Because a genetic interaction was found between crb and khc, Crb localization was examined in the developing photoreceptors of khc mutants. khc was dispensable during early eye differentiation and development. However, khc mutant photoreceptors showed a range of abnormalities in the apical membrane domain depending on the position along the proximal-distal axis in pupal photoreceptors. The khc mutant showed a progressive mislocalization in the apical domain along the distal-proximal axis during rhabdomere elongation. The khc mutation also led to a similar progressive defect in the stabilized microtubule structures, strongly suggesting that Khc is essential for microtubule structure and Crb localization during distal to proximal rhabdomere elongation in pupal morphogenesis. This role of Khc in apical domain control was further supported by khc's gain-of-function phenotype. Khc overexpression in photoreceptors caused disruption of the apical membrane domain and the stabilized microtubules in the developing photoreceptors. CONCLUSIONS/SIGNIFICANCE: In summary, we examined the role of khc in the regulation of the apical Crb domain in developing photoreceptors. Since the rhabdomeres in

  19. Postnatal development of cerebellar zones revealed by neurofilament heavy chain protein expression

    Directory of Open Access Journals (Sweden)

    Joshua J White

    2013-05-01

    Full Text Available The cerebellum is organized into parasagittal zones that control sensory-motor behavior. Although the architecture of adult zones is well understood, very little is known about how zones emerge during development. Understanding the process of zone formation is an essential step towards unraveling how circuits are constructed to support specific behaviors. Therefore, we focused this study on postnatal development to determine the spatial and temporal changes that establish zonal patterns during circuit formation. We used a combination of wholemount and tissue section immunohistochemistry in mice to show that the cytoskeletal protein neurofilament heavy chain (NFH is a robust marker for postnatal cerebellar zonal patterning. The patterned expression of NFH is initiated shortly after birth, and compared to the domains of several known zonal markers such as zebrin II, HSP25, neurogranin, and phospholipase Cβ4 (PLCβ4, NFH does not exhibit transient expression patterns that are typically remodeled between stages, and the adult zones do not emerge after a period of uniform expression in all lobules. Instead, we found that throughout postnatal development NFH gradually reveals distinct zones in each cerebellar lobule. The boundaries of individual NFH zones sharpen over time, as zones are refined during the second and third weeks after birth. Double labeling with neurogranin and PLCβ4 further revealed that although the postnatal expression of NFH is spatially and temporally unique, its pattern of zones respects a fundamental and well-known molecular topography in the cerebellum. The dynamics of NFH expression support the hypothesis that adult circuits are derived from an embryonic map that is refined into zones during the first three-weeks of life.

  20. Human heavy-chain variable region gene family nonrandomly rearranged in familial chronic lymphocytic leukemia

    International Nuclear Information System (INIS)

    Shen, A.; Humphries, C.; Tucker, P.; Blattner, F.

    1987-01-01

    The authors have identified a family of human immunoglobulin heavy-chain variable-region (V/sub H/) genes, one member of which is rearranged in two affected members of a family in which the father and four of five siblings developed chronic lymphocytic leukemia. Cloning and sequencing of the rearranged V/sub H/ genes from leukemic lymphocytes of three affected siblings showed that two siblings had rearranged V/sub H/ genes (V/sub H/TS1 and V/sub H/WS1) that were 90% homologous. The corresponding germ-line gene, V/sub H/251, was found to part of a small (four gene) V/sub H/ gene family, which they term V/sub H/V. The DNA sequence homology to V/sub H/WS1 (95%) and V/sub H/TS1 (88%) and identical restriction sites on the 5' side of V/sub H/ confirm that rearrangement of V/sub H/251 followed by somatic mutation produced the identical V/sub H/ gene rearrangements in the two siblings. V/sub H/TS1 is not a functional V/sub H/ gene; a functional V/sub H/ rearrangement was found on the other chromosome of this patient. The other two siblings had different V/sub H/ gene rearrangements. All used different diversity genes. Mechanisms proposed for nonrandom selection of a single V/sub H/ gene include developmental regulation of this V/sub H/ gene rearrangement or selection of a subpopulation of B cells in which this V/sub H/ has been rearranged

  1. Muscle fiber type specific induction of slow myosin heavy chain 2 gene expression by electrical stimulation

    International Nuclear Information System (INIS)

    Crew, Jennifer R.; Falzari, Kanakeshwari; DiMario, Joseph X.

    2010-01-01

    Vertebrate skeletal muscle fiber types are defined by a broad array of differentially expressed contractile and metabolic protein genes. The mechanisms that establish and maintain these different fiber types vary throughout development and with changing functional demand. Chicken skeletal muscle fibers can be generally categorized as fast and fast/slow based on expression of the slow myosin heavy chain 2 (MyHC2) gene in fast/slow muscle fibers. To investigate the cellular and molecular mechanisms that control fiber type formation in secondary or fetal muscle fibers, myoblasts from the fast pectoralis major (PM) and fast/slow medial adductor (MA) muscles were isolated, allowed to differentiate in vitro, and electrically stimulated. MA muscle fibers were induced to express the slow MyHC2 gene by electrical stimulation, whereas PM muscle fibers did not express the slow MyHC2 gene under identical stimulation conditions. However, PM muscle fibers did express the slow MyHC2 gene when electrical stimulation was combined with inhibition of inositol triphosphate receptor (IP3R) activity. Electrical stimulation was sufficient to increase nuclear localization of expressed nuclear-factor-of-activated-T-cells (NFAT), NFAT-mediated transcription, and slow MyHC2 promoter activity in MA muscle fibers. In contrast, both electrical stimulation and inhibitors of IP3R activity were required for these effects in PM muscle fibers. Electrical stimulation also increased levels of peroxisome-proliferator-activated receptor-γ co-activator-1 (PGC-1α) protein in PM and MA muscle fibers. These results indicate that MA muscle fibers can be induced by electrical stimulation to express the slow MyHC2 gene and that fast PM muscle fibers are refractory to stimulation-induced slow MyHC2 gene expression due to fast PM muscle fiber specific cellular mechanisms involving IP3R activity.

  2. Effect of ageing on the myosin heavy chain composition of the human sternocleidomastoid muscle.

    Science.gov (United States)

    Meznaric, M; Eržen, I; Karen, P; Cvetko, E

    2018-03-01

    The myosin heavy chain (MyHC) composition of ageing limb muscles is transformed into a slower phenotype and expresses fast-twitch fibre type atrophy, presumably due to age-related motor unit remodelling and a change in the patterns of physical activity. It is not known if ageing affects the sternocleidomastoid muscle (SCM) in a similar way. The goal of the study was to analyze the MyHC composition and the size of muscle fibres in the ageing SCM by immunohistochemical methods and quantitative analysis and stereology using our own software for morphometry. We hypothesize that with ageing the MyHC composition of SCM transforms similarly as in ageing limb muscles, but the size of the muscle fibres is less effected as in limb muscles. The study was performed on the autopsy samples of the SCM in 12 older males. The results were compared with those published in our previous study on 15 young adult males. An ageing SCM transforms into a slower MyHC profile: the percentage of slow-twitch fibres is enhanced (numerical proportion 44.6 vs. 31.5%, Pfibres is diminished (numerical proportion 14.1 vs. 26.8%, Pfast-twitch fibres expressing MyHC-2a and 2x is smaller (50.6 vs. 63.5%, Pfibres expressing the fastest myosin isoform MyHC-2x is smaller too (19.0 vs. 34.5%, Pfibres expressing the fastest MyHC-2x provide circumstantial evidence for: (i) more fast-twitch than slow-twitch motor units being lost; and (ii) reinnervation by the surviving motor units. There appears to be no significant influence on muscle fibre size, which is congruent with relatively unchanged SCM activity during life. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Myosin heavy-chain isoforms in the flight and leg muscles of hummingbirds and zebra finches.

    Science.gov (United States)

    Velten, Brandy P; Welch, Kenneth C

    2014-06-01

    Myosin heavy chain (MHC) isoform complement is intimately related to a muscle's contractile properties, yet relatively little is known about avian MHC isoforms or how they may vary with fiber type and/or the contractile properties of a muscle. The rapid shortening of muscles necessary to power flight at the high wingbeat frequencies of ruby-throated hummingbirds and zebra finches (25-60 Hz), along with the varied morphology and use of the hummingbird hindlimb, provides a unique opportunity to understand how contractile and morphological properties of avian muscle may be reflected in MHC expression. Isoforms of the hummingbird and zebra finch flight and hindlimb muscles were electrophoretically separated and compared with those of other avian species representing different contractile properties and fiber types. The flight muscles of the study species operate at drastically different contraction rates and are composed of different histochemically defined fiber types, yet each exhibited the same, single MHC isoform corresponding to the chicken adult fast isoform. Thus, despite quantitative differences in the contractile demands of flight muscles across species, this isoform appears necessary for meeting the performance demands of avian powered flight. Variation in flight muscle contractile performance across species may be due to differences in the structural composition of this conserved isoform and/or variation within other mechanically linked proteins. The leg muscles were more varied in their MHC isoform composition across both muscles and species. The disparity in hindlimb MHC expression between hummingbirds and the other species highlights previously observed differences in fiber type composition and thrust production during take-off. Copyright © 2014 the American Physiological Society.

  4. VHH Antibodies: Reagents for Mycotoxin Detection in Food Products

    Directory of Open Access Journals (Sweden)

    Jia Wang

    2018-02-01

    Full Text Available Mycotoxins are the toxic secondary metabolites produced by fungi and they are a worldwide public health concern. A VHH antibody (or nanobody is the smallest antigen binding entity and is produced by heavy chain only antibodies. Compared with conventional antibodies, VHH antibodies overcome many pitfalls typically encountered in clinical therapeutics and immunodiagnostics. Likewise, VHH antibodies are particularly useful for monitoring mycotoxins in food and feedstuffs, as they are easily genetic engineered and have superior stability. In this review, we summarize the efforts to produce anti-mycotoxins VHH antibodies and associated assays, presenting VHH as a potential tool in mycotoxin analysis.

  5. [Construction of human phage antibody library and screening for human monoclonal antibodies of amylin].

    Science.gov (United States)

    Gong, Qian; Li, Chang-ying; Chang, Ji-wu; Zhu, Tie-hong

    2012-06-01

    To screen monoclonal antibodies to amylin from a constructed human phage antibody library and identify their antigenic specificity and combining activities. The heavy chain Fd fragment and light chain of human immunoglobulin genes were amplified from peripheral blood lymphocytes of healthy donors using RT-PCR, and then inserted into phagemid pComb3XSS to generate a human phage antibody library. The insertion of light chain or heavy chain Fd genes were identified by PCR after the digestion of Sac I, Xba I, Xho Iand Spe I. One of positive clones was analyzed by DNA sequencing. The specific anti-amylin clones were screened from antibody library against human amylin antigens and then the positive clones were determined by Phage-ELISA analysis. A Fab phage antibody library with 0.8×10(8); members was constructed with the efficacy of about 70%. DNA sequence analysis indicated V(H); gene belonged to V(H);3 gene family and V(λ); gene belonged to the V(λ); gene family. Using human amylin as panning antigen, specific anti-amylin Fab antibodies were enriched by screening the library for three times. Phage-ELISA assay showed the positive clones had very good specificity to amylin antigen. The successful construction of a phage antibody library and the identification of anti-amylin Fab antibodies provide a basis for further study and preparation of human anti-amylin antibodies.

  6. Characterization of the fine specificity of peptide antibodies to HLA-DQ beta-chain molecules

    DEFF Research Database (Denmark)

    Petersen, J S; Atar, D; Karlsen, Alan E

    1990-01-01

    In an attempt to produce epitope specific antisera which could distinguish two closely associated HLA-DQ beta-chain alleles, we immunized 20 rabbits with synthetic peptides representing sequences from the first domain of the HLA-DQw8 and -DQw7 beta-chain molecules, differing only by one amino acid...... in position 57. Several of the antisera in immunoblotting specifically recognized either the HLA-DQw7 or the HLA-DQw8 beta-chain allele as previously reported. The fine specificity of the antisera was tested in ELISA using synthetic peptides of varying length as solid phase antigen. Two out of the 20 antisera...

  7. Analysis of the relationship between end-to-end distance and activity of single-chain antibody against colorectal carcinoma.

    Science.gov (United States)

    Zhang, Jianhua; Liu, Shanhong; Shang, Zhigang; Shi, Li; Yun, Jun

    2012-08-22

    We investigated the relationship of End-to-end distance between VH and VL with different peptide linkers and the activity of single-chain antibodies by computer-aided simulation. First, we developed (G4S)n (where n = 1-9) as the linker to connect VH and VL, and estimated the 3D structure of single-chain Fv antibody (scFv) by homologous modeling. After molecular models were evaluated and optimized, the coordinate system of every protein was built and unified into one coordinate system, and End-to-end distances calculated using 3D space coordinates. After expression and purification of scFv-n with (G4S)n as n = 1, 3, 5, 7 or 9, the immunoreactivity of purified ND-1 scFv-n was determined by ELISA. A multi-factorial relationship model was employed to analyze the structural factors affecting scFv: rn=ABn-ABO2+CDn-CDO2+BCn-BCst2. The relationship between immunoreactivity and r-values revealed that fusion protein structure approached the desired state when the r-value = 3. The immunoreactivity declined as the r-value increased, but when the r-value exceeded a certain threshold, it stabilized. We used a linear relationship to analyze structural factors affecting scFv immunoreactivity.

  8. Single chain variable fragment antibodies block aggregation and toxicity induced by familial ALS-linked mutant forms of SOD1.

    Science.gov (United States)

    Ghadge, Ghanashyam D; Pavlovic, John D; Koduvayur, Sujatha P; Kay, Brian K; Roos, Raymond P

    2013-08-01

    Approximately 10% of amyotrophic lateral sclerosis (ALS) cases are familial (known as FALS) with an autosomal dominant inheritance pattern, and ~25% of FALS cases are caused by mutations in Cu/Zn superoxide dismutase (SOD1). There is convincing evidence that mutant SOD1 (mtSOD1) kills motor neurons (MNs) because of a gain-of-function toxicity, most likely related to aggregation of mtSOD1. A number of recent reports have suggested that antibodies can be used to treat mtSOD1-induced FALS. To follow up on the use of antibodies as potential therapeutics, we generated single chain fragments of variable region antibodies (scFvs) against SOD1, and then expressed them as 'intrabodies' within a motor neuron cell line. In the present study, we describe isolation of human scFvs that interfere with mtSOD1 in vitro aggregation and toxicity. These scFvs may have therapeutic potential in sporadic ALS, as well as FALS, given that sporadic ALS may also involve abnormalities in the SOD1 protein or activity. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Improved affinity of a chicken single-chain antibody to avian ...

    African Journals Online (AJOL)

    linyuan

    2011-12-12

    Dec 12, 2011 ... Jianhua Wang. 1. , Ying Zhang ... et al., 1991; Dougan et al., 1998; Chang et al., 2009). The site-directed ... Analysis of the three-dimensional structure of the antigen-antibody ..... Altering the fine specificity of an anti-Legionella ...

  10. Hotspots for Vitamin-Steroid-Thyroid Hormone Response Elements Within Switch Regions of Immunoglobulin Heavy Chain Loci Predict a Direct Influence of Vitamins and Hormones on B Cell Class Switch Recombination.

    Science.gov (United States)

    Hurwitz, Julia L; Penkert, Rhiannon R; Xu, Beisi; Fan, Yiping; Partridge, Janet F; Maul, Robert W; Gearhart, Patricia J

    2016-03-01

    Vitamin A deficiencies are common throughout the world and have a significant negative influence on immune protection against viral infections. Mouse models demonstrate that the production of IgA, a first line of defense against viruses at mucosal sites, is inhibited in the context of vitamin A deficiency. In vitro, the addition of vitamin A to activated B cells can enhance IgA expression, but downregulate IgE. Previous reports have demonstrated that vitamin A modifies cytokine patterns, and in so doing may influence antibody isotype expression by an indirect mechanism. However, we have now discovered hundreds of potential response elements among Sμ, Sɛ, and Sα switch sites within immunoglobulin heavy chain loci. These hotspots appear in both mouse and human loci and include targets for vitamin receptors and related proteins (e.g., estrogen receptors) in the nuclear receptor superfamily. Full response elements with direct repeats are relatively infrequent or absent in Sγ regions although half-sites are present. Based on these results, we pose a hypothesis that nuclear receptors have a direct effect on the immunoglobulin heavy chain class switch recombination event. We propose that vitamin A may alter S site accessibility to activation-induced deaminase and nonhomologous end-joining machinery, thereby influencing the isotype switch, antibody production, and protection against viral infections at mucosal sites.

  11. Enzymatic single-chain antibody tagging: a universal approach to targeted molecular imaging and cell homing in cardiovascular disease.

    Science.gov (United States)

    Ta, H T; Prabhu, S; Leitner, E; Jia, F; von Elverfeldt, D; Jackson, Katherine E; Heidt, T; Nair, A K N; Pearce, H; von Zur Muhlen, C; Wang, X; Peter, K; Hagemeyer, C E

    2011-08-05

    Antibody-targeted delivery of imaging agents can enhance the sensitivity and accuracy of current imaging techniques. Similarly, homing of effector cells to disease sites increases the efficacy of regenerative cell therapy while reducing the number of cells required. Currently, targeting can be achieved via chemical conjugation to specific antibodies, which typically results in the loss of antibody functionality and in severe cell damage. An ideal conjugation technique should ensure retention of antigen-binding activity and functionality of the targeted biological component. To develop a biochemically robust, highly reproducible, and site-specific coupling method using the Staphylococcus aureus sortase A enzyme for the conjugation of a single-chain antibody (scFv) to nanoparticles and cells for molecular imaging and cell homing in cardiovascular diseases. This scFv specifically binds to activated platelets, which play a pivotal role in thrombosis, atherosclerosis, and inflammation. The conjugation procedure involves chemical and enzyme-mediated coupling steps. The scFv was successfully conjugated to iron oxide particles (contrast agents for magnetic resonance imaging) and to model cells. Conjugation efficiency ranged between 50% and 70%, and bioactivity of the scFv after coupling was preserved. The targeting of scFv-coupled cells and nanoparticles to activated platelets was strong and specific as demonstrated in in vitro static adhesion assays, in a flow chamber system, in mouse intravital microscopy, and in in vivo magnetic resonance imaging of mouse carotid arteries. This unique biotechnological approach provides a versatile and broadly applicable tool for procuring targeted regenerative cell therapy and targeted molecular imaging in cardiovascular and inflammatory diseases and beyond.

  12. Removal of round off errors in the matrix exponential method for solving the heavy nuclide chain

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Noh, Jae Man; Joo, Hyung Kook

    2005-01-01

    Many nodal codes for core simulation adopt the micro-depletion procedure for the depletion analysis. Unlike the macro-depletion procedure, the microdepletion procedure uses micro-cross sections and number densities of important nuclides to generate the macro cross section of a spatial calculational node. Therefore, it needs to solve the chain equations of the nuclides of interest to obtain their number densities. There are several methods such as the matrix exponential method (MEM) and the chain linearization method (CLM) for solving the nuclide chain equations. The former solves chain equations exactly even when the cycles that come from the alpha decay exist in the chain while the latter solves the chain approximately when the cycles exist in the chain. The former has another advantage over the latter. Many nodal codes for depletion analysis, such as MASTER, solve only the hard coded nuclide chains with the CLM. Therefore, if we want to extend the chain by adding some more nuclides to the chain, we have to modify the source code. In contrast, we can extend the chain just by modifying the input in the MEM because it is easy to implement the MEM solver for solving an arbitrary nuclide chain. In spite of these advantages of the MEM, many nodal codes adopt the chain linearization because the former has a large round off error when the flux level is very high or short lived or strong absorber nuclides exist in the chain. In this paper, we propose a new technique to remove the round off errors in the MEM and we compared the performance of the two methods

  13. Myosin heavy chain expression in cranial, pectoral fin, and tail muscle regions of zebrafish embryos.

    Science.gov (United States)

    Peng, Mou-Yun; Wen, Hui-Ju; Shih, Li-Jane; Kuo, Ching-Ming; Hwang, Sheng-Ping L

    2002-12-01

    To investigate whether different myosin heavy chain (MHC) isoforms may constitute myofibrils in the trunk and tail musculature and if their respective expression may be regulated by spadetail (spt) and no tail (brachyury), we identified and characterized mRNA expression patterns of an embryonic- and tail muscle-specific MHC gene (named myhz2) during zebrafish development in wild type, spt, and ntl mutant embryos. The identified myhz2 MHC gene encodes a polypeptide containing 1,935 amino acids. Deduced amino acid comparisons showed that myhz2 MHC shared 92.6% sequence identity with that of carp fast skeletal MHC. Temporal and spatial myhz2 MHC mRNA expression patterns were analyzed by quantitative RT-PCR and whole-mount in situ hybridization using primer pairs and probes designed from the 3'-untranslated region (UTR). Temporally myhz2 MHC mRNA appears in pharyngula embryos and peaks in protruding-mouth larvae. The expression level decreased in 7-day-old hatching larvae, and mRNA expression was not detectable in adult fish. Spatially in pharyngula embryos, mRNA was localized only in the tail somite region, while in long-pec embryos, transcripts were also expressed in the two cranial muscle elements of the adductor mandibulae and medial rectus, as well as in pectoral fin muscles and the tail muscle region. Myhz2 MHC mRNA was expressed in most cranial muscle elements, pectoral fin muscles, and the tail muscle region of 3-day-old hatching larvae. In contrast, no expression of myhz2 MHC mRNA could be observed in spt prim-15 mutant embryos. In spt long-pec mutant embryos, transcripts were expressed in two cranial muscle elements and the tail muscle region, but not in pectoral fin muscles, while only trace amounts of myhz2 MHC mRNA were expressed in the remaining tail muscle region of 38 hpf and long-pec ntl mutant embryos. Copyright 2002 Wiley-Liss, Inc.

  14. Frequency patterns of T-cell exposed motifs in immunoglobulin heavy chain peptides presented by MHCs

    Directory of Open Access Journals (Sweden)

    Robert D. Bremel

    2014-10-01

    Full Text Available Immunoglobulins are highly diverse protein sequences that are processed and presented to T-cells by B-cells and other antigen presenting cells. We examined a large dataset of immunoglobulin heavy chain variable regions (IGHV to assess the diversity of T-cell exposed motifs (TCEM. TCEM comprise those amino acids in a MHC-bound peptide which face outwards, surrounded by the MHC histotope, and which engage the T-cell receptor. Within IGHV there is a distinct pattern of predicted MHC class II binding and a very high frequency of re-use of the TCEMs. The re-use frequency indicates that only a limited number of different cognate T-cells are required to engage many different clonal B-cells. The amino acids in each outward-facing TCEM are intercalated with the amino acids of inward-facing MHC groove-exposed motifs (GEM. Different GEM may have differing, allele-specific, MHC binding affinities. The intercalation of TCEM and GEM in a peptide allows for a vast combinatorial repertoire of epitopes, each eliciting a different response. Outcome of T-cell receptor binding is determined by overall signal strength, which is a function of the number of responding T-cells and the duration of engagement. Hence, the frequency of T-cell exposed motif re-use appears to be an important determinant of whether a T-cell response is stimulatory or suppressive. The frequency distribution of TCEMs implies that somatic hypermutation is followed by clonal expansion that develop along repeated pathways. The observations of TCEM and GEM derived from immunoglobulins suggest a relatively simple, yet powerful, mechanism to correlate T-cell polyspecificity, through re-use of TCEMs, with a very high degree of specificity achieved by combination with a diversity of GEMs. The frequency profile of TCEMs also points to an economical mechanism for maintaining T-cell memory, recall, and self-discrimination based on an endogenously generated profile of motifs.

  15. Prolonged Cre expression driven by the α-myosin heavy chain promoter can be cardiotoxic.

    Science.gov (United States)

    Pugach, Emily K; Richmond, Phillip A; Azofeifa, Joseph G; Dowell, Robin D; Leinwand, Leslie A

    2015-09-01

    Studying the importance of genetic factors in a desired cell type or tissue necessitates the use of precise genetic tools. With the introduction of bacteriophage Cre recombinase/loxP mediated DNA editing and promoter-specific Cre expression, it is feasible to generate conditional knockout mice in which particular genes are disrupted in a cell type-specific manner in vivo. In cardiac myocytes, this is often achieved through α-myosin heavy chain promoter (αMyHC)-driven Cre expression in conjunction with a loxP-site flanked gene of interest. Recent studies in other cell types demonstrate toxicity of Cre expression through induction of DNA damage. However, it is unclear to what extent the traditionally used αMyHC-Cre line [1] may exhibit cardiotoxicity. Further, the genotype of αMyHC-Cre(+/-) is not often included as a control group in cardiac myocyte-specific knockout studies. Here we present evidence that these αMyHC-Cre(+/-) mice show molecular signs of cardiac toxicity by 3months of age and exhibit decreased cardiac function by 6months of age compared to wild-type littermates. Hearts from αMyHC-Cre(+/-) mice also display evidence of fibrosis, inflammation, and DNA damage. Interestingly, some of the early functional changes observed in αMyHC-Cre(+/-) mice are sexually dimorphic. Given the high level of Cre recombinase expression resulting from expression from the αMyHC promoter, we asked if degenerate loxP-like sites naturally exist in the mouse genome and if so, whether they are affected by Cre in the absence of canonical loxP-sites. Using a novel bioinformatics search tool, we identified 619 loxP-like sites with 4 or less mismatches to the canonical loxP-site. 227 sites overlapped with annotated genes and 55 of these genes were expressed in cardiac muscle. Expression of ~26% of the 27 genes tested was disrupted in αMyHC-Cre(+/-) mice indicating potential targeting by Cre. Taken together, these results highlight both the importance of using αMyHC-Cre mice

  16. Signal peptide-dependent inhibition of MHC class I heavy chain translation by rhesus cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Colin J Powers

    2008-10-01

    Full Text Available The US2-11 region of human and rhesus cytomegalovirus encodes a conserved family of glycoproteins that inhibit MHC-I assembly with viral peptides, thus preventing cytotoxic T cell recognition. Since HCMV lacking US2-11 is no longer able to block assembly and transport of MHC-I, we examined whether this is also observed for RhCMV lacking the corresponding region. Unexpectedly, recombinant RhCMV lacking US2-11 was still able to inhibit MHC-I expression in infected fibroblasts, suggesting the presence of an additional MHC-I evasion mechanism. Progressive deletion analysis of RhCMV-specific genomic regions revealed that MHC-I expression is fully restored upon additional deletion of rh178. The protein encoded by this RhCMV-specific open reading frame is anchored in the endoplasmic reticulum membrane. In the presence of rh178, RhCMV prevented MHC-I heavy chain (HC expression, but did not inhibit mRNA transcription or association of HC mRNA with translating ribosomes. Proteasome inhibitors stabilized a HC degradation intermediate in the absence of rh178, but not in its presence, suggesting that rh178 prevents completion of HC translation. This interference was signal sequence-dependent since replacing the signal peptide with that of CD4 or murine HC rendered human HCs resistant to rh178. We have identified an inhibitor of antigen presentation encoded by rhesus cytomegalovirus unique in both its lack of homology to any other known protein and in its mechanism of action. By preventing signal sequence-dependent HC translocation, rh178 acts prior to US2, US3 and US11 which attack MHC-I proteins after protein synthesis is completed. Rh178 is the first viral protein known to interfere at this step of the MHC-I pathway, thus taking advantage of the conserved nature of HC leader peptides, and represents a new mechanism of translational interference.

  17. Effects of different activity and inactivity paradigms on myosin heavy chain gene expression in striated muscle

    Science.gov (United States)

    Baldwin, K. M.; Haddad, F.

    2001-01-01

    The goal of this mini-review is to summarize findings concerning the role that different models of muscular activity and inactivity play in altering gene expression of the myosin heavy chain (MHC) family of motor proteins in mammalian cardiac and skeletal muscle. This was done in the context of examining parallel findings concerning the role that thyroid hormone (T(3), 3,5,3'-triiodothyronine) plays in MHC expression. Findings show that both cardiac and skeletal muscles of experimental animals are initially undifferentiated at birth and then undergo a marked level of growth and differentiation in attaining the adult MHC phenotype in a T(3)/activity level-dependent fashion. Cardiac MHC expression in small mammals is highly sensitive to thyroid deficiency, diabetes, energy deprivation, and hypertension; each of these interventions induces upregulation of the beta-MHC isoform, which functions to economize circulatory function in the face of altered energy demand. In skeletal muscle, hyperthyroidism, as well as interventions that unload or reduce the weight-bearing activity of the muscle, causes slow to fast MHC conversions. Fast to slow conversions, however, are seen under hypothyroidism or when the muscles either become chronically overloaded or subjected to intermittent loading as occurs during resistance training and endurance exercise. The regulation of MHC gene expression by T(3) or mechanical stimuli appears to be strongly regulated by transcriptional events, based on recent findings on transgenic models and animals transfected with promoter-reporter constructs. However, the mechanisms by which T(3) and mechanical stimuli exert their control on transcriptional processes appear to be different. Additional findings show that individual skeletal muscle fibers have the genetic machinery to express simultaneously all of the adult MHCs, e.g., slow type I and fast IIa, IIx, and IIb, in unique combinations under certain experimental conditions. This degree of

  18. Production and characterization of monoclonal antibodies against α-globin chain-containing human hemoglobins for detecting α-thalassemia disease.

    Science.gov (United States)

    Pakdeepak, Kanet; Pata, Supansa; Chiampanichayakul, Sawitree; Kasinrerk, Watchara; Tatu, Thanusak

    2016-01-01

    Monoclonal antibodies against α-globin containing human Hbs, named AMS-Alpha1 and AMS-Alpha 2, were produced by the hybridoma technique using spleen cells enriched by the newly developed B lymphocyte enrichment protocol. These two monoclonal antibodies were of IgM class, reacting to only intact form of human Hbs A, A2, E, and F, which contain α-globin chain. By the indirect ELISA, the AMS-Alpha1 and AMS-Alpha 2 quantified less amount of α-globin chain containing hemoglobins in HbH disease than the SEA-α thalassemia 1 carriers and normal individuals. It was thus anticipated that these monoclonal antibodies can be used for detecting Hb Bart's hydrops fetalis in which no α-globin chain is produced.

  19. Botulinum neurotoxin type A radiolabeled at either the light or the heavy chain

    International Nuclear Information System (INIS)

    Dekleva, M.L.; DasGupta, B.R.; Sathyamoorthy, V.

    1989-01-01

    Botulinum neurotoxin (NT) has two distinct structural regions called L and H chains (approximately 50 and approximately 100 kDa, respectively). Although the H chain is responsible for binding of the NT to neuronal cells, it is not known which of the subunits is internalized and therefore responsible for causing the blockage of acetylcholine release in susceptible neuronal cells. In this report we describe for the first time the preparation of type A NT which is selectively radiolabeled at either the L or the H chain subunit. Such NT preparations will be useful as tools for determining the distribution of L and H chains in poisoned neuronal cells and the role that each subunit plays in inducing toxicity. The L and H chains of the NT (approximately 150 kDa) were separated, purified, and then individually radiolabeled by reductive methylation of the lysine residues using [3H]- or [14C]formaldehyde. The labeled L and H chains were reconjugated with the complementary unlabeled L and H chains. Formation of -S-S- and noncovalent bonds between the L and H chains regenerated the approximately 150 kDa NT. Autoradiographs of sodium dodecyl sulfate polyacrylamide gels confirmed that each reconstituted NT preparation was labeled at only one subunit chain. NT selectively labeled at either the L or the H chain had specific radioactivities of ca. 25-30 and 45-55 microCi/mumol, respectively, and toxicity (mouse LD50/mg protein) values of 2.2 +/- 1.1 X 10(7) and 3.0 +/- 1.0 X 10(7), respectively. A linear increase in the specific radioactivity of L and H chain subunits was observed with increasing concentrations of 3H- or 14C-labeled formaldehyde in the reaction mixture and with increasing concentrations of L or H chain in the reaction mixture

  20. Chlorpyrifos- and chlorpyrifos oxon-induced neurite retraction in pre-differentiated N2a cells is associated with transient hyperphosphorylation of neurofilament heavy chain and ERK 1/2

    Energy Technology Data Exchange (ETDEWEB)

    Sindi, Ramya A., E-mail: ramya.sindi2010@my.ntu.ac.uk [Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom); School of Applied Medical Sciences, Umm Al-Qura University, Makkah (Saudi Arabia); Harris, Wayne [Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom); Arnott, Gordon [School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS (United Kingdom); Flaskos, John [Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Lloyd Mills, Chris [School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS (United Kingdom); Hargreaves, Alan J., E-mail: alan.hargreaves@ntu.ac.uk [Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS (United Kingdom)

    2016-10-01

    Chlorpyrifos (CPF) and CPF-oxon (CPO) are known to inhibit neurite outgrowth but little is known about their ability to induce neurite retraction in differentiating neuronal cells. The aims of this study were to determine the ability of these compounds to destabilize neurites and to identify the key molecular events involved. N2a cells were induced to differentiate for 20 h before exposure to CPF or CPO for 2–8 h. Fixed cell monolayers labeled with carboxyfluorescein succinimidyl ester or immunofluorescently stained with antibodies to tubulin (B512) or phosphorylated neurofilament heavy chain (Ta51) showed time- and concentration-dependent reductions in numbers and length of axon-like processes compared to the control, respectively, retraction of neurites being observed within 2 h of exposure by live cell imaging. Neurofilament disruption was also observed in treated cells stained by indirect immunofluorescence with anti-phosphorylated neurofilament heavy chain (NFH) monoclonal antibody SMI34, while the microtubule network was unaffected. Western blotting analysis revealed transiently increased levels of reactivity of Ta51 after 2 h exposure and reduced levels of reactivity of the same antibody following 8 h treatment with both compounds, whereas reactivity with antibodies to anti-total NFH or anti-tubulin was not affected. The alteration in NFH phosphorylation at 2 h exposure was associated with increased activation of extracellular signal-regulated protein kinase ERK 1/2. However, increased levels of phosphatase activity were observed following 8 h exposure. These findings suggest for the first time that organophosphorothionate pesticide-induced neurite retraction in N2a cells is associated with transient increases in NFH phosphorylation and ERK1/2 activation. - Highlights: • Chlorpyrifos and chlorpyrifos oxon induced rapid neurite retraction in N2a cells. • This occurred following transient hyperphosphorylation of ERK 1/2. • It was concomitant with

  1. Chlorpyrifos- and chlorpyrifos oxon-induced neurite retraction in pre-differentiated N2a cells is associated with transient hyperphosphorylation of neurofilament heavy chain and ERK 1/2

    International Nuclear Information System (INIS)

    Sindi, Ramya A.; Harris, Wayne; Arnott, Gordon; Flaskos, John; Lloyd Mills, Chris; Hargreaves, Alan J.

    2016-01-01

    Chlorpyrifos (CPF) and CPF-oxon (CPO) are known to inhibit neurite outgrowth but little is known about their ability to induce neurite retraction in differentiating neuronal cells. The aims of this study were to determine the ability of these compounds to destabilize neurites and to identify the key molecular events involved. N2a cells were induced to differentiate for 20 h before exposure to CPF or CPO for 2–8 h. Fixed cell monolayers labeled with carboxyfluorescein succinimidyl ester or immunofluorescently stained with antibodies to tubulin (B512) or phosphorylated neurofilament heavy chain (Ta51) showed time- and concentration-dependent reductions in numbers and length of axon-like processes compared to the control, respectively, retraction of neurites being observed within 2 h of exposure by live cell imaging. Neurofilament disruption was also observed in treated cells stained by indirect immunofluorescence with anti-phosphorylated neurofilament heavy chain (NFH) monoclonal antibody SMI34, while the microtubule network was unaffected. Western blotting analysis revealed transiently increased levels of reactivity of Ta51 after 2 h exposure and reduced levels of reactivity of the same antibody following 8 h treatment with both compounds, whereas reactivity with antibodies to anti-total NFH or anti-tubulin was not affected. The alteration in NFH phosphorylation at 2 h exposure was associated with increased activation of extracellular signal-regulated protein kinase ERK 1/2. However, increased levels of phosphatase activity were observed following 8 h exposure. These findings suggest for the first time that organophosphorothionate pesticide-induced neurite retraction in N2a cells is associated with transient increases in NFH phosphorylation and ERK1/2 activation. - Highlights: • Chlorpyrifos and chlorpyrifos oxon induced rapid neurite retraction in N2a cells. • This occurred following transient hyperphosphorylation of ERK 1/2. • It was concomitant with

  2. B-Lymphoblastic Lymphomas Evolving from Follicular Lymphomas Co-Express Surrogate Light Chains and Mutated Gamma Heavy Chains.

    Science.gov (United States)

    Slot, Linda M; Hoogeboom, Robbert; Smit, Laura A; Wormhoudt, Thera A M; Biemond, Bart J; Oud, Monique E C M; Schilder-Tol, Esther J M; Mulder, André B; Jongejan, Aldo; van Kampen, Antoine H C; Kluin, Philip M; Guikema, Jeroen E J; Bende, Richard J; van Noesel, Carel J M

    2016-12-01

    Follicular lymphoma (FL) is an indolent B-cell non-Hodgkin lymphoma able to transform into germinal center-type diffuse large B-cell lymphoma. We describe four extraordinary cases of FL, which progressed to TdT + CD20 - precursor B-lymphoblastic lymphoma (B-LBL). Fluorescence in situ hybridization analysis showed that all four B-LBLs had acquired a MYC translocation on transformation. Comparative genomic hybridization analysis of one case demonstrated that in addition to 26 numerical aberrations that were shared between the FL and B-LBL, deletion of CDKN2A/B and 17q11, 14q32 amplification, and copy-neutral loss of heterozygosity of 9p were gained in the B-LBL cells. Whole-exome sequencing revealed mutations in FMN2, NEB, and SYNE1 and a nonsense mutation in KMT2D, all shared by the FL and B-LBL, and TNFRSF14, SMARCA2, CCND3 mutations uniquely present in the B-LBL. Remarkably, all four FL-B-LBL pairs expressed IgG. In two B-LBLs, evidence was obtained for ongoing rearrangement of IG light chain variable genes and expression of the surrogate light chain. IGHV mutation analysis showed that all FL-B-LBL pairs harbored identical or near-identical somatic mutations. From the somatic gene alterations found in the IG and non-IG genes, we conclude that the FLs and B-LBLs did not develop in parallel from early t(14;18)-positive IG-unmutated precursors, but that the B-LBLs developed from preexistent FL subclones that accumulated additional genetic damage. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  3. Effects of hypothyroidism on myosin heavy chain composition and fibre types of fast skeletal muscles in a small marsupial, Antechinus flavipes.

    Science.gov (United States)

    Zhong, Wendy W H; Withers, Kerry W; Hoh, Joseph F Y

    2010-04-01

    Effects of drug-induced hypothyroidism on myosin heavy chain (MyHC) content and fibre types of fast skeletal muscles were studied in a small marsupial, Antechinus flavipes. SDS-PAGE of MyHCs from the tibialis anterior and gastrocnemius revealed four isoforms, 2B, 2X, 2A and slow, in that order of decreasing abundance. After 5 weeks treatment with methimazole, the functionally fastest 2B MyHC significantly decreased, while 2X, 2A and slow MyHCs increased. Immunohistochemistry using monospecific antibodies to each of the four MyHCs revealed decreased 2b and 2x fibres, and increased 2a and hybrid fibres co-expressing two or three MyHCs. In the normally homogeneously fast superficial regions of these muscles, evenly distributed slow-staining fibres appeared, resembling the distribution of slow primary myotubes in fast muscles during development. Hybrid fibres containing 2A and slow MyHCs were virtually absent. These results are more detailed but broadly similar to the earlier studies on eutherians. We hypothesize that hypothyroidism essentially reverses the effects of thyroid hormone on MyHC gene expression of muscle fibres during myogenesis, which differ according to the developmental origin of the fibre: it induces slow MyHC expression in 2b fibres derived from fast primary myotubes, and shifts fast MyHC expression in fibres of secondary origin towards 2A, but not slow, MyHC.

  4. Complement component C1r mediated cleavage of the heavy chain of the major histocompatibility class I antigens

    DEFF Research Database (Denmark)

    Eriksson, H; Nissen, Mogens Holst

    1992-01-01

    Apart from cleaving C1s, we demonstrate for the first time that: 1) at concentrations found in serum, the activated forms of the complement components C1r in addition to C1s can cleave the heavy chain of MHC class I antigens, 2) the cleavage by C1r and C1s is seemingly dependent upon a native con......-chain of MHC class I was shown to take place between the alpha 2- and alpha 3- domains as estimated by the Con A-Sepharose precipitation pattern on SDS-PAGE. The alpha 1/alpha 2 fragment was still shown to interact with beta 2-microglobulin as shown by immunoprecipitation....

  5. Prognostic significance of highly sulfated chondroitin sulfates in ovarian cancer defined by the single chain antibody GD3A11.

    Science.gov (United States)

    van der Steen, Sophieke C H A; van Tilborg, Angela A G; Vallen, Myrtille J E; Bulten, Johan; van Kuppevelt, Toin H; Massuger, Leon F A G

    2016-03-01

    The extracellular matrix (ECM) of ovarian cancer may provide a number of potential biomarkers. Chondroitin sulfate (CS), a class of sulfated polysaccharides, is abundantly present in the ECM of ovarian cancer. Structural alterations of CS chains (i.e. sulfation pattern) have been demonstrated to play a role in cancer development and progression. In this study we investigate the potential of highly sulfated CS as a biomarker in ovarian cancer using the single chain antibody GD3A11 selected by the phage display technology. The specificity of the antibody was determined by an indirect ELISA. GD3A11 epitope expression was assessed by immunohistochemistry in healthy organs, benign and malignant ovarian tumors (N=359) and correlated to clinical parameters. The CHST15 gene, responsible for the biosynthesis of highly sulfated CS was evaluated for mutation and methylation status. The GD3A11 epitope was minimally expressed in normal organs. Intense expression was observed in the ECM of different ovarian cancer subtypes, in contrast to benign ovarian tumors. Expression was independent of tumor grade, FIGO stage, and the use chemotherapy. For the aggressive ovarian cancer phenotype, intense expression was identified as an independent predictor for poor prognosis. CHST15 gene analysis showed no mutations nor an altered methylation status. Specific highly sulfated CS motifs expressed in the tumoral ECM hold biomarker potential in ovarian cancer patients. These matrix motifs constitute a novel class of biomarkers with prognostic significance and may be instrumental for innovative diagnostic and therapeutic applications (e.g. targeted therapy) in management of ovarian cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. [Construction and screening of phage antibody libraries against epidermal growth factor receptor and soluble expression of single chain Fv].

    Science.gov (United States)

    Sheng, Wei-Jin; Miao, Qing-Fang; Zhen, Yong-Su

    2009-06-01

    Recent studies have shown that epidermal growth factor receptor (EGFR) is an important target for cancer therapy. The present study prepared single chain Fv (scFv) directed against EGFR. Balb/c mice were immunized by human carcinoma A431 cells, and total RNA of the splenic cells was extracted. VH and VL gene fragments were amplified by RT-PCR and further joined into scFv gene with a linker, then scFv gene fragments were ligated into the phagemid vector pCANTAB 5E. The phagemid containing scFv were transformed into electro-competent E. coli TG1 cells. The recombinant phage antibody library was constructed through rescuing the transformed cells with help phage M13K07. The specified recombinant phages were enriched through 5 rounds of affinity panning and the anti-EGFR phage scFv clones were screened and identified with ELISA. A total of 48 clones from the library were selected randomly and 45 clones were identified positive. After infecting E. coli HB2151 cells with one positive clone, soluble recombinant antibodies about 27 kD were produced and located in the periplasm and the supernatant. The result of sequencing showed that the scFv gene was 768 bp, which encoded 256 amino acid residues. VH and VL including 3 CDRs and 4 FRs, respectively, were all homologous to mouse Ig. The soluble scFv showed the specific binding activity to purified EGFR and EGFR located in carcinoma cell membrane. The successful preparation of anti-EGFR scFv will provide an EGFR targeted molecule for the development of antibody-based drugs and biological therapy of cancer.

  7. Hybridization-based antibody cDNA recovery for the production of recombinant antibodies identified by repertoire sequencing.

    Science.gov (United States)

    Valdés-Alemán, Javier; Téllez-Sosa, Juan; Ovilla-Muñoz, Marbella; Godoy-Lozano, Elizabeth; Velázquez-Ramírez, Daniel; Valdovinos-Torres, Humberto; Gómez-Barreto, Rosa E; Martinez-Barnetche, Jesús

    2014-01-01

    High-throughput sequencing of the antibody repertoire is enabling a thorough analysis of B cell diversity and clonal selection, which may improve the novel antibody discovery process. Theoretically, an adequate bioinformatic analysis could allow identification of candidate antigen-specific antibodies, requiring their recombinant production for experimental validation of their specificity. Gene synthesis is commonly used for the generation of recombinant antibodies identified in silico. Novel strategies that bypass gene synthesis could offer more accessible antibody identification and validation alternatives. We developed a hybridization-based recovery strategy that targets the complementarity-determining region 3 (CDRH3) for the enrichment of cDNA of candidate antigen-specific antibody sequences. Ten clonal groups of interest were identified through bioinformatic analysis of the heavy chain antibody repertoire of mice immunized with hen egg white lysozyme (HEL). cDNA from eight of the targeted clonal groups was recovered efficiently, leading to the generation of recombinant antibodies. One representative heavy chain sequence from each clonal group recovered was paired with previously reported anti-HEL light chains to generate full antibodies, later tested for HEL-binding capacity. The recovery process proposed represents a simple and scalable molecular strategy that could enhance antibody identification and specificity assessment, enabling a more cost-efficient generation of recombinant antibodies.

  8. Targeted Multiplex Imaging Mass Spectrometry with Single Chain Fragment Variable (scfv) Recombinant Antibodies

    Science.gov (United States)

    Thiery, Gwendoline; Mernaugh, Ray L.; Yan, Heping; Spraggins, Jeffrey M.; Yang, Junhai; Parl, Fritz F.; Caprioli, Richard M.

    2012-10-01

    Recombinant scfv antibodies specific for CYP1A1 and CYP1B1 P450 enzymes were combined with targeted imaging mass spectrometry to simultaneously detect the P450 enzymes present in archived, paraffin-embedded, human breast cancer tissue sections. By using CYP1A1 and CYP1B1 specific scfv, each coupled to a unique reporter molecule (i.e., a mass tag) it was possible to simultaneously detect multiple antigens within a single tissue sample with high sensitivity and specificity using mass spectrometry. The capability of imaging multiple antigens at the same time is a significant advance that overcomes technical barriers encountered when using present day approaches to develop assays that can simultaneously detect more than a single antigen in the same tissue sample.

  9. Characterization of a Single Chain Fv Antibody that Reacts with Free Morphine

    OpenAIRE

    Matsukizono, Miho; Kamegawa, Mariko; Tanaka, Koichi; Kohra, Shinya; Arizono, Koji; Hamazoe, Yuta; Sugimura, Kazuhisa

    2013-01-01

    An immune phage library derived from mice, hyperimmunized with morphine-conjugated BSA, was used to isolate a single-chain Fv (scFv) clone, M86, with binding activity to morphine-conjugated thyroglobulin (morphine-C-Tg) but not to codeine-, cocaine-, or ketamine-conjugated Tg. Surface plasmon resonance analysis using a morphine-C-Tg-coupled CM5 sensor chip showed that the Kd value was 1.26 × 10−8 M. To analyze its binding activity to free morphine and related compounds, we performed a competi...

  10. Rapid switch-off of the human myosin heavy chain IIX gene after heavy load muscle contractions is sustained for at least four days.

    Science.gov (United States)

    Andersen, J L; Gruschy-Knudsen, T

    2018-02-01

    Long-term heavy load contractions decrease the relative amount of the myosin heavy chain (MHC) IIX isoform in human skeletal muscle, but the timing of the down-regulation in the short term is unknown. Untrained subjects performed two resistance bouts, in two consecutive days, with one leg, the other leg serving as a control (age 24±1, n=5). Muscle biopsies were obtained in both legs before, immediately after, and 24, 54, and 96 hours after exercise. Serial cryosection analysis combined immunohistochemistry and ATPase histochemistry with In Situ hybridization to identify the distribution of MHC isoforms and their corresponding transcripts, enabling identification of transitional fibers. Fibers positive solely for MHC IIX mRNA decreased in the exercised leg throughout the study period. At 96 hours post-exercise, no fibers solely expressed MHC IIX mRNA. In contrast, the number of fibers expressing MHC IIA mRNA increased throughout the study period. The percentage of fibers expressing mRNA for MHC I was unchanged in both legs at all time points. Pronounced depletion of glycogen in the MHC IIX fibers of the exercised leg verifies that the type IIX fibers were active during the heavy load contractions. Major mismatch between MHC at the mRNA and protein levels was only found in the fibers of the exercised leg. These data provide unequivocal in situ evidence of an immediate shutdown of the MHC IIX gene after resistance exercise. A further novel finding was that the silencing of the MHC IIX gene is sustained at least 4 days after removal of the stimulus. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. MAK33 antibody light chain amyloid fibrils are similar to oligomeric precursors.

    Directory of Open Access Journals (Sweden)

    Manuel Hora

    Full Text Available Little structural information is available so far on amyloid fibrils consisting of immunoglobulin light chains. It is not understood which features of the primary sequence of the protein result in fibril formation. We report here MAS solid-state NMR studies to identify the structured core of κ-type variable domain light chain fibrils. The core contains residues of the CDR2 and the β-strands D, E, F and G of the native immunoglobulin fold. The assigned core region of the fibril is distinct in comparison to the core identified in a previous solid-state NMR study on AL-09 by Piehl at. al, suggesting that VL fibrils can adopt different topologies. In addition, we investigated a soluble oligomeric intermediate state, previously termed the alternatively folded state (AFS, using NMR and FTIR spectroscopy. The NMR oligomer spectra display a high degree of similarity when compared to the fibril spectra, indicating a high structural similarity of the two aggregation states. Based on comparison to the native state NMR chemical shifts, we suggest that fibril formation via domain-swapping seems unlikely. Moreover, we used our results to test the quality of different amyloid prediction algorithms.

  12. Dynein Heavy Chain, Encoded by Two Genes in Agaricomycetes, Is Required for Nuclear Migration in Schizophyllum commune.

    Directory of Open Access Journals (Sweden)

    Melanie Brunsch

    Full Text Available The white-rot fungus Schizophyllum commune (Agaricomycetes was used to study the cell biology of microtubular trafficking during mating interactions, when the two partners exchange nuclei, which are transported along microtubule tracks. For this transport activity, the motor protein dynein is required. In S. commune, the dynein heavy chain is encoded in two parts by two separate genes, dhc1 and dhc2. The N-terminal protein Dhc1 supplies the dimerization domain, while Dhc2 encodes the motor machinery and the microtubule binding domain. This split motor protein is unique to Basidiomycota, where three different sequence patterns suggest independent split events during evolution. To investigate the function of the dynein heavy chain, the gene dhc1 and the motor domain in dhc2 were deleted. Both resulting mutants were viable, but revealed phenotypes in hyphal growth morphology and mating behavior as well as in sexual development. Viability of strain Δdhc2 is due to the higher expression of kinesin-2 and kinesin-14, which was proven via RNA sequencing.

  13. Analyses of Dynein Heavy Chain Mutations Reveal Complex Interactions Between Dynein Motor Domains and Cellular Dynein Functions

    Science.gov (United States)

    Sivagurunathan, Senthilkumar; Schnittker, Robert R.; Razafsky, David S.; Nandini, Swaran; Plamann, Michael D.; King, Stephen J.

    2012-01-01

    Cytoplasmic dynein transports cargoes for a variety of crucial cellular functions. However, since dynein is essential in most eukaryotic organisms, the in-depth study of the cellular function of dynein via genetic analysis of dynein mutations has not been practical. Here, we identify and characterize 34 different dynein heavy chain mutations using a genetic screen of the ascomycete fungus Neurospora crassa, in which dynein is nonessential. Interestingly, our studies show that these mutations segregate into five different classes based on the in vivo localization of the mutated dynein motors. Furthermore, we have determined that the different classes of dynein mutations alter vesicle trafficking, microtubule organization, and nuclear distribution in distinct ways and require dynactin to different extents. In addition, biochemical analyses of dynein from one mutant strain show a strong correlation between its in vitro biochemical properties and the aberrant intracellular function of that altered dynein. When the mutations were mapped to the published dynein crystal structure, we found that the three-dimensional structural locations of the heavy chain mutations were linked to particular classes of altered dynein functions observed in cells. Together, our data indicate that the five classes of dynein mutations represent the entrapment of dynein at five separate points in the dynein mechanochemical and transport cycles. We have developed N. crassa as a model system where we can dissect the complexities of dynein structure, function, and interaction with other proteins with genetic, biochemical, and cell biological studies. PMID:22649085

  14. SNPs within the beta myosin heavy chain (MYH7 and the pyruvate kinase muscle (PKM2 genes in horse

    Directory of Open Access Journals (Sweden)

    Vincenzo Russo

    2010-01-01

    Full Text Available Two highly expressed skeletal muscle genes (the MYH7 gene encoding the myosin heavy chain slow/β-cardiac isoform and the PKM2 gene encoding the pyruvate kinase muscle isoforms were investigated with the objective to identify DNA markers in horses. A panel of DNA samples from different horse breeds was analysed using a PCR-single strand conformation polymorphism (SSCP approach. Four and two alleles were identified for the MYH7 and PKM2 loci, respectively. Mendelian inheritance of alleles of the two investigated genes was confirmed analysing horse families. Sequencing of PCR products obtained from the MYH7 and PKM2 genes made it possible to characterise two SSCP alleles for each gene. The polymorphisms found in the MYH7 and PKM2 genes were further studied in 61 and 68 horses of three (Italian Heavy Draught Horse, Italian Saddler and Murgese and five (Franches-Montagnes, Haflinger, Italian Heavy Draught Horse, Murgese and Standardbred breeds, respectively. Allele frequencies of the two loci varied among the considered breeds. The SNPs discovery in MYH7 and PKM2 genes makes it possible to locate new molecular markers to ECA1. The identified markers could be used in association analysis with performance traits in horses.

  15. Immunogenicity and Protective Efficacy of Brugia malayi Heavy Chain Myosin as Homologous DNA, Protein and Heterologous DNA/Protein Prime Boost Vaccine in Rodent Model.

    Directory of Open Access Journals (Sweden)

    Jyoti Gupta

    Full Text Available We earlier demonstrated the immunoprophylactic efficacy of recombinant heavy chain myosin (Bm-Myo of Brugia malayi (B. malayi in rodent models. In the current study, further attempts have been made to improve this efficacy by employing alternate approaches such as homologous DNA (pcD-Myo and heterologous DNA/protein prime boost (pcD-Myo+Bm-Myo in BALB/c mouse model. The gene bm-myo was cloned in a mammalian expression vector pcDNA 3.1(+ and protein expression was confirmed in mammalian Vero cell line. A significant degree of protection (79.2%±2.32 against L3 challenge in pcD-Myo+Bm-Myo immunized group was observed which was much higher than that exerted by Bm-Myo (66.6%±2.23 and pcD-Myo (41.6%±2.45. In the heterologous immunized group, the percentage of peritoneal leukocytes such as macrophages, neutrophils, B cells and T cells marginally increased and their population augmented further significantly following L3 challenge. pcD-Myo+Bm-Myo immunization elicited robust cellular and humoral immune responses as compared to pcD-Myo and Bm-Myo groups as evidenced by an increased accumulation of CD4+, CD8+ T cells and CD19+ B cells in the mouse spleen and activation of peritoneal macrophages. Though immunized animals produced antigen-specific IgG antibodies and isotypes, sera of mice receiving pcD-Myo+Bm-Myo or Bm-Myo developed much higher antibody levels than other groups and there was profound antibody-dependent cellular adhesion and cytotoxicity (ADCC to B. malayi infective larvae (L3. pcD-Myo+Bm-Myo as well as Bm-Myo mice generated a mixed T helper cell phenotype as evidenced by the production of both pro-inflammatory (IL-2, IFN-γ and anti-inflammatory (IL-4, IL-10 cytokines. Mice receiving pcD-Myo on contrary displayed a polarized pro-inflammatory immune response. The findings suggest that the priming of animals with DNA followed by protein booster generates heightened and mixed pro- and anti-inflammatory immune responses that are capable of

  16. Construction of a recombinant single chain antibody recognizing nonreducing terminal mannose residues applicable to immunohistochemistry.

    Science.gov (United States)

    Yuasa, Noriyuki; Iida, Noriko; Sakaue, Hiroyuki; Zhang, Wei; Wilczynski, Sharon; Fujita-Yamaguchi, Yoko

    2007-10-01

    We recently reported characterization of 25 clones isolated from a phage library displaying human scFvs using a neoglycolipid Man3-DPPE, which was synthesized from mannotriose (Man3) and dipalmitoylphosphatidylethanolamine (DPPE). Of those, 5A3 scFv was successfully expressed and purified as a humanized scFv-Fc form (Sakai et al., Biochemistry 46:253, 2007, Zhang et al. ibid 263). To carry out immunohistochemistry (IHC) in human tissues, a HA tag sequence was introduced to the 5A3 scFv-Fc gene and the resulting construct was transfected to murine myeloma NS0 cells. The 5A3 scFv-Fc protein expressed was affinity-purified. Sodium dodecyl sulfate polyacrylamide gel electrophoresis under nonreducing and reducing conditions and enzyme-linked immunosorbent assay confirmed that 5A3 scFv-Fc protein is dimeric and retained the ability to recognize nonreducing terminal mannose residues. IHC staining of non-neoplastic tissues by this recombinant antibody revealed that no immunoreactivity was detectable in most of 16 tissues examined. Exceptions were found in IHC staining of kidney and pancreas, which demonstrated clear staining of proximal tubules and islet of Langerhans, respectively. These results demonstrated that nonreducing terminal mannose residues are not usually present under normal physiological conditions. This study thus provided a potentially useful tool for examination of the nonreducing terminal mannose residues, which may become exposed under certain pathophysiologycal conditions.

  17. Somatic hypermutation and junctional diversification at Ig heavy chain loci in the nurse shark.

    Science.gov (United States)

    Malecek, Karolina; Brandman, Julie; Brodsky, Jennie E; Ohta, Yuko; Flajnik, Martin F; Hsu, Ellen

    2005-12-15

    We estimate there are approximately 15 IgM H chain loci in the nurse shark genome and have characterized one locus. It consists of one V, two D, and one J germline gene segments, and the constant (C) region can be distinguished from all of the others by a unique combination of restriction endonuclease sites in Cmu2. On the basis of these Cmu2 markers, 22 cDNA clones were selected from an epigonal organ cDNA library from the same individual; their C region sequences proved to be the same up to the polyadenylation site. With the identification of the corresponding germline gene segments, CDR3 from shark H chain rearrangements could be analyzed precisely, for the first time. Considerable diversity was generated by trimming and N addition at the three junctions and by varied recombination patterns of the two D gene segments. The cDNA sequences originated from independent rearrangements events, and most carried both single and contiguous substitutions. The 53 point mutations occurred with a bias for transition changes (53%), whereas the 78 tandem substitutions, mostly 2-4 bp long, do not (36%). The nature of the substitution patterns is the same as for mutants from six loci of two nurse shark L chain isotypes, showing that somatic hypermutation events are very similar at both H and L chain genes in this early vertebrate. The cis-regulatory elements targeting somatic hypermutation must have already existed in the ancestral Ig gene, before H and L chain divergence.

  18. Polyclonal and monoclonal antibodies in clinic.

    Science.gov (United States)

    Wootla, Bharath; Denic, Aleksandar; Rodriguez, Moses

    2014-01-01

    Immunoglobulins (Ig) or antibodies are heavy plasma proteins, with sugar chains added to amino-acid residues by N-linked glycosylation and occasionally by O-linked glycosylation. The versatility of antibodies is demonstrated by the various functions that they mediate such as neutralization, agglutination, fixation with activation of complement and activation of effector cells. Naturally occurring antibodies protect the organism against harmful pathogens, viruses and infections. In addition, almost any organic chemical induces antibody production of antibodies that would bind specifically to the chemical. These antibodies are often produced from multiple B cell clones and referred to as polyclonal antibodies. In recent years, scientists have exploited the highly evolved machinery of the immune system to produce structurally and functionally complex molecules such as antibodies from a single B clone, heralding the era of monoclonal antibodies. Most of the antibodies currently in the clinic, target components of the immune system, are not curative and seek to alleviate symptoms rather than cure disease. Our group used a novel strategy to identify reparative human monoclonal antibodies distinct from conventional antibodies. In this chapter, we discuss the therapeutic relevance of both polyclonal and monoclonal antibodies in clinic.

  19. Flow cytometric analysis of immunoglobulin heavy chain expression in B-cell lymphoma and reactive lymphoid hyperplasia

    Science.gov (United States)

    Grier, David D; Al-Quran, Samer Z; Cardona, Diana M; Li, Ying; Braylan, Raul C

    2012-01-01

    The diagnosis of B-cell lymphoma (BCL) is often dependent on the detection of clonal immunoglobulin (Ig) light chain expression. In some BCLs, the determination of clonality based on Ig light chain restriction may be difficult. The aim of our study was to assess the utility of flow cytometric analysis of surface Ig heavy chain (HC) expression in lymphoid tissues in distinguishing lymphoid hyperplasias from BCLs, and also differentiating various BCL subtypes. HC expression on B-cells varied among different types of hyperplasias. In follicular hyperplasia, IgM and IgD expression was high in mantle cells while germinal center cells showed poor HC expression. In other hyperplasias, B cell compartments were blurred but generally showed high IgD and IgM expression. Compared to hyperplasias, BCLs varied in IgM expression. Small lymphocytic lymphomas had lower IgM expression than mantle cell lymphomas. Of importance, IgD expression was significantly lower in BCLs than in hyperplasias, a finding that can be useful in differentiating lymphoma from reactive processes. PMID:22400070

  20. Secretion of an immunoreactive single-chain variable fragment antibody against mouse interleukin 6 by Lactococcus lactis.

    Science.gov (United States)

    Shigemori, Suguru; Ihara, Masaki; Sato, Takashi; Yamamoto, Yoshinari; Nigar, Shireen; Ogita, Tasuku; Shimosato, Takeshi

    2017-01-01

    Interleukin 6 (IL-6) is an important pathogenic factor in development of various inflammatory and autoimmune diseases and cancer. Blocking antibodies against molecules associated with IL-6/IL-6 receptor signaling are an attractive candidate for the prevention or therapy of these diseases. In this study, we developed a genetically modified strain of Lactococcus lactis secreting a single-chain variable fragment antibody against mouse IL-6 (IL6scFv). An IL6scFv-secretion vector was constructed by cloning an IL6scFv gene fragment into a lactococcal secretion plasmid and was electroporated into L. lactis NZ9000 (NZ-IL6scFv). Secretion of recombinant IL6scFv (rIL6scFv) by nisin-induced NZ-IL6scFv was confirmed by western blotting and was optimized by tuning culture conditions. We found that rIL6scFv could bind to commercial recombinant mouse IL-6. This result clearly demonstrated the immunoreactivity of rIL6scFv. This is the first study to engineer a genetically modified strain of lactic acid bacteria (gmLAB) that produces a functional anti-cytokine scFv. Numerous previous studies suggested that mucosal delivery of biomedical proteins using gmLAB is an effective and low-cost way to treat various disorders. Therefore, NZ-IL6scFv may be an attractive tool for the research and development of new IL-6 targeting agents for various inflammatory and autoimmune diseases as well as for cancer.

  1. Purification of correctly oxidized MHC class I heavy-chain molecules under denaturing conditions: a novel strategy exploiting disulfide assisted protein folding

    DEFF Research Database (Denmark)

    Ferré, Henrik; Ruffet, Emmanuel; Blicher, Thomas

    2003-01-01

    The aim of this study has been to develop a strategy for purifying correctly oxidized denatured major histocompability complex class I (MHC-I) heavy-chain molecules, which on dilution, fold efficiently and become functional. Expression of heavy-chain molecules in bacteria results in the formation...... of insoluble cellular inclusion bodies, which must be solubilized under denaturing conditions. Their subsequent purification and refolding is complicated by the fact that (1). correct folding can only take place in combined presence of beta(2)-microglobulin and a binding peptide; and (2). optimal in vitro...... conditions for disulfide bond formation ( approximately pH 8) and peptide binding ( approximately pH 6.6) are far from complementary. Here we present a two-step strategy, which relies on uncoupling the events of disulfide bond formation and peptide binding. In the first phase, heavy-chain molecules...

  2. Purification of correctly oxidized MHC class I heavy-chain molecules under denaturing conditions: A novel strategy exploiting disulfide assisted protein folding

    DEFF Research Database (Denmark)

    Ferré, Henrik; Ruffet, E.; Blicher, T.

    2003-01-01

    The aim of this study has been to develop a strategy for purifying correctly oxidized denatured major histocompability complex class I (MHC-I) heavy-chain molecules, which on dilution, fold efficiently and become functional. Expression of heavy-chain molecules in bacteria results in the formation...... of insoluble cellular inclusion bodies, which must be solubilized under denaturing conditions. Their subsequent purification and refolding is complicated by the fact that (1) correct folding can only take place in combined presence of beta(2)-microglobulin and a binding peptide; and (2) optimal in vitro...... conditions for disulfide bond formation (similar topH 8) and peptide binding (similar topH 6.6) are far from complementary. Here we present a two-step strategy, which relies on uncoupling the events of disulfide bond formation and peptide binding. In the first phase, heavy-chain molecules with correct...

  3. Activated platelets in carotid artery thrombosis in mice can be selectively targeted with a radiolabeled single-chain antibody.

    Directory of Open Access Journals (Sweden)

    Timo Heidt

    Full Text Available BACKGROUND: Activated platelets can be found on the surface of inflamed, rupture-prone and ruptured plaques as well as in intravascular thrombosis. They are key players in thrombosis and atherosclerosis. In this study we describe the construction of a radiolabeled single-chain antibody targeting the LIBS-epitope of activated platelets to selectively depict platelet activation and wall-adherent non-occlusive thrombosis in a mouse model with nuclear imaging using in vitro and ex vivo autoradiography as well as small animal SPECT-CT for in vivo analysis. METHODOLOGY/PRINCIPAL FINDINGS: LIBS as well as an unspecific control single-chain antibody were labeled with (111Indium ((111In via bifunctional DTPA ( = (111In-LIBS/(111In-control. Autoradiography after incubation with (111In-LIBS on activated platelets in vitro (mean 3866 ± 28 DLU/mm(2, 4010 ± 630 DLU/mm(2 and 4520 ± 293 DLU/mm(2 produced a significantly higher ligand uptake compared to (111In-control (2101 ± 76 DLU/mm(2, 1181 ± 96 DLU/mm(2 and 1866 ± 246 DLU/mm(2 indicating a specific binding to activated platelets; P<0.05. Applying these findings to an ex vivo mouse model of carotid artery thrombosis revealed a significant increase in ligand uptake after injection of (111In-LIBS in the presence of small thrombi compared to the non-injured side, as confirmed by histology (49630 ± 10650 DLU/mm(2 vs. 17390 ± 7470 DLU/mm(2; P<0.05. These findings could also be reproduced in vivo. SPECT-CT analysis of the injured carotid artery with (111In-LIBS resulted in a significant increase of the target-to-background ratio compared to (111In-control (1.99 ± 0.36 vs. 1.1 ± 0.24; P < 0.01. CONCLUSIONS/SIGNIFICANCE: Nuclear imaging with (111In-LIBS allows the detection of platelet activation in vitro and ex vivo with high sensitivity. Using SPECT-CT, wall-adherent activated platelets in carotid arteries could be depicted in vivo. These results encourage further studies elucidating the role of

  4. Preparation and functional studies of hydroxyethyl chitosan nanoparticles loaded with anti-human death receptor 5 single-chain antibody

    Directory of Open Access Journals (Sweden)

    Yang J

    2014-05-01

    Full Text Available Jingjing Yang,1,3,* Xiaoping Huang,1,3,* Fanghong Luo,1 Xiaofeng Cheng,3 Lianna Cheng,3 Bin Liu,4 Lihong Chen,2 Ruyi Hu,1,3 Chunyan Shi,1,3 Guohong Zhuang,1,3 Ping Yin2 1Anti-Cancer Research Center, Medical College, Xiamen University, Fujian, People's Republic of China, 2The Department of Pathology, Zhongshan Hospital, Xiamen University, Xiamen, People's Republic of China, 3Organ transplantation institution, Xiamen University, Xiamen, People's Republic of China, 4Jilin Vocational College of Industry and Technology, Jilin, People's Republic of China  *These authors contributed equally to this work Objective: To prepare hydroxyethyl chitosan nanoparticles loaded with anti-human death receptor 5 single-chain antibody, and study their characteristics, functions, and mechanisms of action. Materials and methods: The anti-human death receptor 5 single-chain antibody was constructed and expressed. Protein-loaded hydroxyethyl chitosan nanoparticles were prepared, and their size, morphology, particle-size distribution and surface zeta potential were measured by scanning electron microscopy and laser particle-size analysis. Mouse H22 hepatocellular carcinoma cells were cultured, and growth inhibition was examined using the CellTiter-Blue cell-viability assay. Flow cytometry and Hoechst 33342 were employed to measure cell apoptosis. Kunming mice with H22 tumor models were treated with protein-loaded hydroxyethyl chitosan nanoparticles, and their body weight and tumor size were measured, while hematoxylin and eosin staining was used to detect antitumor effects in vivo and side effects from tumors. Results: The protein-loaded hydroxyethyl chitosan nanoparticles had good stability; the zeta potential was -24.2±0.205, and the dispersion index was 0.203. The inhibition of the protein-loaded hydroxyethyl chitosan nanoparticles on H22 growth was both time- and dose-dependent. Increased expressions of active caspase 8, active caspase 3, and BAX were detected

  5. Sequences of 12 monoclonal anti-dinitrophenyl spin-label antibodies for NMR studies

    International Nuclear Information System (INIS)

    Leahy, D.J.; Rule, G.S.; Whittaker, M.M.; McConnell, H.M.

    1988-01-01

    Eleven monoclonal antibodies specific for a spin-labeled dinitrophenyl hapten (DNP-SL) have been produces for use in NMR studies. They have been named AN01 and ANO3-AN12. The stability constants for the association of these antibodies with DNP-SL and related haptens were measured by fluorescence quenching. cDNA clones coding for the heavy and light chains of each antibody and of an additional anti-DNP-SL monoclonal antibody, ANO2, have been isolated. The nucleic acid sequence of the 5' end of each clone has been determined, and the amino acid sequence of the variable regions of each antibody has been deduced from the cDNA sequence. The sequences are relatively heterogeneous, but both the heavy and the light chains of ANO1 and ANO3 are derived from the same variable-region gene families as those of the ANO2 antibody. ANO7 has a heavy chain that is related to that of ANO2, and ANO9 has a related light chain. ANO5 and ANO6 are unrelated to ANO2 but share virtually identical heavy and light chains. Preliminary NMR difference spectra comparing related antibodies show that sequence-specific assignment of resonances is possible. Such spectra also provide a measure of structural relatedness

  6. Molecular immune recognition of botulinum neurotoxin B. The light chain regions that bind human blocking antibodies from toxin-treated cervical dystonia patients. Antigenic structure of the entire BoNT/B molecule.

    Science.gov (United States)

    Atassi, M Zouhair; Jankovic, Joseph; Steward, Lance E; Aoki, K Roger; Dolimbek, Behzod Z

    2012-01-01

    We recently mapped the regions on the heavy (H) chain of botulinum neurotoxin, type B (BoNT/B) recognized by blocking antibodies (Abs) from cervical dystonia (CD) patients who develop immunoresistance during toxin treatment. Since blocking could also be effected by Abs directed against regions on the light (L) chain, we have mapped here the L chain, using the same 30 CD antisera. We synthesized, purified and characterized 32 19-residue L chain peptides that overlapped successively by 5 residues (peptide L32 overlapped with peptide N1 of the H chain by 12 residues). In a given patient, Abs against the L chain seemed less intense than those against H chain. Most sera recognized a limited set of L chain peptides. The levels of Abs against a given region varied with the patient, consistent with immune responses to each epitope being under separate MHC control. The peptides most frequently recognized were: L13, by 30 of 30 antisera (100%); L22, by 23 of 30 (76.67%); L19, by 15 of 30 (50.00%); L26, by 11 of 30 (36.70%); and L14, by 12 of 30 (40.00%). The activity of L14 probably derives from its overlap with L13. The levels of Ab binding decreased in the following order: L13 (residues 169-187), L22 (295-313), L19 (253-271), and L26 (351-369). Peptides L12 (155-173), L18 (239-257), L15 (197-215), L1 (1-19) and L23 (309-327) exhibited very low Ab binding. The remaining peptides had little or no Ab-binding activity. The antigenic regions are analyzed in terms of their three-dimensional locations and the enzyme active site. With the previous localization of the antigenic regions on the BoNT/B H chain, the human Ab recognition of the entire BoNT/B molecule is presented and compared to the recognition of BoNT/A by human blocking Abs. Copyright © 2011. Published by Elsevier GmbH.

  7. Genotype phenotype correlations of cardiac beta-myosin heavy chain mutations in Indian patients with hypertrophic and dilated cardiomyopathy

    DEFF Research Database (Denmark)

    Rai, Taranjit Singh; Ahmad, Shamim; Bahl, Ajay

    2009-01-01

    The aim of the current study was to determine the frequency of mutations in the beta-myosin heavy chain gene (MYH7) in a cohort of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) and their families, and to investigate correlations between genotype and phenotype. About 130...... consecutive patients diagnosed with HCM or DCM (69 with HCM and 61 with DCM) attending the cardiology clinic of Post Graduate Institute of Medical Education and Research were screened for mutations in the MYH7 gene. The control group for genetic studies consisted of 100 healthy subjects. We report 14...... mutations in 6 probands (5 probands in HCM and 1 proband in DCM) and their family members. Out of these 6 mutations, 3 are new and are being reported for the first time. One known mutation (p.Gly716Arg) was found to be "de novo" which resulted in severe asymmetric septal hypertrophy (31 mm) and resulted...

  8. Position of nonmuscle myosin heavy chain IIA (NMMHC-IIA) mutations predicts the natural history of MYH9-related disease

    DEFF Research Database (Denmark)

    Pecci, A.; Panza, E.; Pujol-Moix, N.

    2008-01-01

    MYH9-related disease (MYH9-RD) is a rare autosomal-dominant disorder caused by mutations in MYH9, the gene for the heavy chain of nonmuscle myosin IIA (NMMHC-IIA). All patients present from birth with macrothrombocytopenia, but in infancy or adult life, some of them develop sensorineural deafness...... to 50 unrelated pedigrees. The risk of noncongenital manifestations associated with different genotypes was estimated over time by event-free survival analysis. We demonstrated that all subjects with mutations in the motor domain of NMMHC-IIA present with severe thrombocytopenia and develop nephritis...... and deafness before the age of 40 years, while those with mutations in the tail domain have a much lower risk of noncongenital complications and significantly higher platelet counts. We also evaluated the clinical course of patients with mutations in the four most frequently affected residues of NMMHC...

  9. Proteolysis of the heavy chain of major histocompatibility complex class I antigens by complement component C1s

    DEFF Research Database (Denmark)

    Eriksson, H; Nissen, Mogens Holst

    1990-01-01

    weights of the fragments are in agreement with the cleavage located in the area between the disulphide loops of the alpha 2-and alpha 3-domains of the heavy chain. In addition human C1s complement is able to cleave H-2 antigens from mouse in a similar fashion but not rat MHC class I antigen or mouse MHC...... class II antigen (I-Ad). Mouse MHC class I antigen-specific determinants could also be detected in supernatant from mouse spleen cells incubated with C1r and C1s. These results indicate the presence in the body fluids of a non-membrane-bound soluble form of the alpha 1-and alpha 2-domains which...

  10. A Comparative Analysis of Polymerase Chain Reaction and Direct Fluorescent Antibody Test for Diagnosis of Genital Herpes.

    Science.gov (United States)

    Patwardhan, Vrushali; Bhalla, Preena; Rawat, Deepti; Garg, Vijay Kumar; Sardana, Kabir; Sethi, Sumit

    2017-01-01

    To compare laboratory tests that can simultaneously detect and type herpes simplex virus (HSV) directly from the genital ulcer specimens in clinically suspected cases of genital herpes. A study was conducted over 10 months and 44 adult male and female patients clinically suspected with genital herpes were recruited. Genital ulcer swab specimens were subjected to glycoprotein-G gene-based conventional polymerase chain reaction (PCR) and commercially available direct fluorescent antibody (DFA) test and the results were compared. PCR for HSV was positive in 82% (36/44) cases. DFA was positive in 68.2% (30/44) cases. There was 100% agreement between HSV types detected by DFA and PCR. The strength of agreement between the results was better in primary genital herpes than recurrent cases. PCR was found to be better in the detection of HSV in recurrent genital herpes patients. It is a better modality, especially when genital herpes clinically presents with ulcerative or crusted lesions, and is also a cheaper alternative as compared to DFA.

  11. Nonmuscle myosin heavy chain IIA is a critical factor contributing to the efficiency of early infection of severe fever with thrombocytopenia syndrome virus.

    Science.gov (United States)

    Sun, Yinyan; Qi, Yonghe; Liu, Chenxuan; Gao, Wenqing; Chen, Pan; Fu, Liran; Peng, Bo; Wang, Haimin; Jing, Zhiyi; Zhong, Guocai; Li, Wenhui

    2014-01-01

    Severe fever with thrombocytopenia syndrome virus (SFTSV) is a novel phlebovirus in the Bunyaviridae family. Most patients infected by SFTSV present with fever and thrombocytopenia, and up to 30% die due to multiple-organ dysfunction. The mechanisms by which SFTSV enters multiple cell types are unknown. SFTSV contains two species of envelope glycoproteins, Gn (44.2 kDa) and Gc (56 kDa), both of which are encoded by the M segment and are cleaved from a precursor polypeptide (about 116 kDa) in the endoplasmic reticulum (ER). Gn fused with an immunoglobulin Fc tag at its C terminus (Gn-Fc) bound to multiple cells susceptible to the infection of SFTSV and blocked viral infection of human umbilical vein endothelial cells (HUVECs). Immunoprecipitation assays following mass spectrometry analysis showed that Gn binds to nonmuscle myosin heavy chain IIA (NMMHC-IIA), a cellular protein with surface expression in multiple cell types. Small interfering RNA (siRNA) knockdown of NMMHC-IIA, but not the closely related NMMHC-IIB or NMMHC-IIC, reduced SFTSV infection, and NMMHC-IIA specific antibody blocked infection by SFTSV but not other control viruses. Overexpression of NMMHC-IIA in HeLa cells, which show limited susceptivity to SFTSV, markedly enhanced SFTSV infection of the cells. These results show that NMMHC-IIA is critical for the cellular entry of SFTSV. As NMMHC-IIA is essential for the normal functions of platelets and human vascular endothelial cells, it is conceivable that NMMHC-IIA directly contributes to the pathogenesis of SFTSV and may be a useful target for antiviral interventions against the viral infection.

  12. Identification of antigen-specific human monoclonal antibodies using high-throughput sequencing of the antibody repertoire.

    Science.gov (United States)

    Liu, Ju; Li, Ruihua; Liu, Kun; Li, Liangliang; Zai, Xiaodong; Chi, Xiangyang; Fu, Ling; Xu, Junjie; Chen, Wei

    2016-04-22

    High-throughput sequencing of the antibody repertoire provides a large number of antibody variable region sequences that can be used to generate human monoclonal antibodies. However, current screening methods for identifying antigen-specific antibodies are inefficient. In the present study, we developed an antibody clone screening strategy based on clone dynamics and relative frequency, and used it to identify antigen-specific human monoclonal antibodies. Enzyme-linked immunosorbent assay showed that at least 52% of putative positive immunoglobulin heavy chains composed antigen-specific antibodies. Combining information on dynamics and relative frequency improved identification of positive clones and elimination of negative clones. and increase the credibility of putative positive clones. Therefore the screening strategy could simplify the subsequent experimental screening and may facilitate the generation of antigen-specific antibodies. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Bioaccumulation of heavy metals both in wild and mariculture food chains in Daya Bay, South China

    Science.gov (United States)

    Qiu, Yao-Wen

    2015-09-01

    Bioaccumulation and trophic transfer of heavy metals both in the natural marine ecosystem (seawater, sediment, coral reef, phytoplankton, macrophyte, shrimp, crab, shellfish, planktivorous and carnivorous fish) and in the mariculture ecosystem (compound feed, trash fish, farmed pompano and snapper) were studied at Daya Bay, a typical subtropical bay in Southern China. The levels of Cu, Zn, Pb and Cd in sediment were 11.7, 10.2, 53.8 and 2.8 times than those in coral reef, respectively. Pb and Zn levels were markedly higher in phytoplankton than in macrophyte, probably caused by the larger specific surface area in phytoplankton. The highest levels of Zn (98.1), Pb (1.87) and Cd (5.11 μg g-1 dw) in wild organisms were all found in clam (Veremolpa scabra), indicating that these metals were apt to bioaccumulate in shellfish. The average concentrations of Cu, Zn, Pb and Cd in wild fish were 3.7, 2.1, 0.4 and 22.2 times than those in farmed fish, confirming the "growth dilution" hypothesis in farmed fish. Heavy metal bioconcentration factors (BCFs) in algae, bioaccumulation factors (BAFs) in wild species and transfer factors (TFs) in organism were calculated and discussed. The results suggested that biologically essential Cu and Zn were easier to accumulate in fish than non-essential Cd. Concentrations of Cu, Zn and Cd were several times higher in wild fish than in farmed fish whereas the opposite was observed for Pb. This metal also showed the highest transfer factor from food, which means that special attention must be given to fish feed production in relation to metal contamination.

  14. Plasma vitamin D-binding protein (GC) factors, immunoglobulin G heavy chain (GM) allotypes and immunoglobulin kappa light chain (KM1) allotype in patients with sarcoidosis and in healthy control subjects

    DEFF Research Database (Denmark)

    Milman, Nils; Thymann, Mariann; Graudal, Niels

    2002-01-01

    BACKGROUND AND AIM: Sarcoidosis is an immune disease with abnormalities in the production of vitamin D and immunoglobulins. The aim was to examine whether the distribution of plasma vitamin D-binding protein = group-specific component (GC) allotypes, immunoglobulin G heavy chain (GM) allotypes an...

  15. Expansion of B-1a cells with germline heavy chain sequence in lupus mice

    Directory of Open Access Journals (Sweden)

    Nichol E Holodick

    2016-03-01

    Full Text Available B6.Sle1.Sle2.Sle3 (B6.TC lupus-prone mice carrying the NZB allele of Cdkn2c, encoding for the cyclin-dependent kinase inhibitor P18INK4, accumulate B-1a cells due to a higher rate of proliferative self-renewal. However, it is unclear whether this affects primarily early appearing B-1a cells of fetal origin or later appearing B-1a cells that emerge from bone marrow. B-1a cells are the major source of natural autoantibodies, and it has been shown that their protective nature is associated with a germline-like sequence, which is characterized by few N-nucleotide insertions and a repertoire skewed towards rearrangements predominated during fetal life, VH11 and VH12. To determine the nature of B-1a cells expanded in B6.TC mice, we amplified immunoglobulin genes by PCR from single cells in mice. Sequencing showed a significantly higher proportion of B-1a cell antibodies display fewer N-additions in B6.TC mice than in B6 control mice. Following this lower number of N-insertions within the CDR-H3 region, the B6.TC B-1a cells display shorter CDR-H3 length than B6 B-1a cells. The absence of N-additions is a surrogate for fetal origin, as TdT expression starts after birth in mice. Therefore, our results suggest that the B-1a cell population is not only expanded in autoimmune B6.TC mice but also qualitatively different with the majority of cells from fetal origin. Accordingly, our sequencing results also demonstrated overuse of VH11 and VH12 in autoimmune B6.TC mice as compared to B6 controls. These results suggest that the development of lupus autoantibodies in these mice is coupled with skewing of the B-1a cell repertoire and possible retention of protective natural antibodies.

  16. Immunoglobulin diversification in B cell malignancies: internal splicing of heavy chain variable region as a by-product of somatic hypermutation

    NARCIS (Netherlands)

    Bende, R. J.; Aarts, W. M.; Pals, S. T.; van Noesel, C. J. M.

    2002-01-01

    In this study we describe alternative splicing of somatically mutated immunoglobulin (Ig) variable heavy chain (V-H) genes in three distinct primary B cell non-Hodgkin's lymphomas (B-NHL). In two V4-34 expressing lymphomas, ie a post-germinal center type B cell chronic lymphocytic leukemia (B-CLL)

  17. [Changes in titin and myosin heavy chain isoform composition in skeletal muscles of Mongolian gerbil (Meriones unguiculatus) after 12-day spaceflight].

    Science.gov (United States)

    Okuneva, A D; Vikhliantsev, I M; Shpagina, M D; Rogachevskiĭ, V V; Khutsian, S S; Poddubnaia, Z A; Grigor'ev, A I

    2012-01-01

    Changes of titin and myosin heavy chain isoform composition in skeletal muscles (m. soleus, m. gastrocnemius, m. tibialis anterior, m. psoas major) in Mongolian Gerbil (Meriones unguiculatus ) were investigated after 12-day spaceflight on board of Russian space vehicle "Foton-M3". In m. psoas and m. soleus in the gerbils from "Flight" group the expected increase in the content of fast myosin heavy chain isoforms (IIxd and IIa, respectively) were observed. No significant differences were found in the content of IIxd and IIa isoforms of myosin heavy chain in m. tibialis anterior in the gerbils from control group as compared to that in "Flight" group. An unexpected increase in the content of slow myosin heavy chain I isoform and a decrease in the content of fast IIx/d isoform in m. gastrocnemius of the gerbils from "Flight" group were observed. In skeletal muscles of the gerbils from "Flight" group the relative content of titin N2A-isoform was reduced (by 1,2-1,7 times), although the content of its NT-isoform, which was revealed in striated muscles of mammals in our experiments earlier, remained the same. When the content of titin N2A-isoform was decreased, no predictable abnormalities in sarcomeric structure and contractile ability of skeletal muscles in the gerbils from "Flight" group were found. An assumption on the leading role of titin NT-isoform in maintenance of structural and functional properties of striated muscles of mammals was made.

  18. 3D Architecture, dynamics as well as functional implications of genome organization of the Prader-Willi/Angelmann syndrome region & the Immunoglobin Heavy-Chain locus

    NARCIS (Netherlands)

    T.A. Knoch (Tobias)

    2008-01-01

    textabstractThe general 3D architecture of the immunoglobin heavy-chain (Igh) locus was determined by a novel interdisciplinary combination of high-resolution FISH and high-resolution epifluorescence spectral distance microscopy with analytical analysis, computer simulations, as well as

  19. Metastasis-associated protein Mts1 (S100A4) inhibits CK2-mediated phosphorylation and self-assembly of the heavy chain of nonmuscle myosin

    DEFF Research Database (Denmark)

    Kriajevska, M; Bronstein, I B; Scott, D J

    2000-01-01

    a regulatory role in the myosin assembly. In the presence of calcium, Mts1 binds at the C-terminal end of the myosin heavy chain close to the site of phosphorylation by protein kinase CK2 (Ser1944). In the present study, we have shown that interaction of Mts1 with the human platelet myosin or C...

  20. The evolution of multiple isotypic IgM heavy chain genes in the shark.

    Science.gov (United States)

    Lee, Victor; Huang, Jing Li; Lui, Ming Fai; Malecek, Karolina; Ohta, Yuko; Mooers, Arne; Hsu, Ellen

    2008-06-01

    The IgM H chain gene organization of cartilaginous fishes consists of 15-200 miniloci, each with a few gene segments (V(H)-D1-D2-J(H)) and one C gene. This is a gene arrangement ancestral to the complex IgH locus that exists in all other vertebrate classes. To understand the molecular evolution of this system, we studied the nurse shark, which has relatively fewer loci, and characterized the IgH isotypes for organization, functionality, and the somatic diversification mechanisms that act upon them. Gene numbers differ slightly between individuals ( approximately 15), but five active IgM subclasses are always present. Each gene undergoes rearrangement that is strictly confined within the minilocus; in B cells there is no interaction between adjacent loci located > or =120 kb apart. Without combinatorial events, the shark IgM H chain repertoire is based on junctional diversity and, subsequently, somatic hypermutation. We suggest that the significant contribution by junctional diversification reflects the selected novelty introduced by RAG in the early vertebrate ancestor, whereas combinatorial diversity coevolved with the complex translocon organization. Moreover, unlike other cartilaginous fishes, there are no germline-joined VDJ at any nurse shark mu locus, and we suggest that such genes, when functional, are species-specific and may have specialized roles. With an entire complement of IgM genes available for the first time, phylogenetic analyses were performed to examine how the multiple Ig loci evolved. We found that all domains changed at comparable rates, but V(H) appears to be under strong positive selection for increased amino acid sequence diversity, and surprisingly, so does Cmicro2.

  1. Measurements on Pb27+ Sources for the CERN Heavy Ion Injection Chain

    CERN Document Server

    Chamings, J A

    2004-01-01

    CERN, the world's largest particle physics laboratory near Geneva, is currently in the process of building the Large Hadron Collider (LHC). Lead-208 will be used in this accelerator and to meet the injection requirements much work is required to find a suitable and reliable heavy ion source. The work in this report covers two ion sources, the Laser Ion Source (LIS), and the Electron Cyclotron Resonance Ion Source (ECRIS). An emittance measurement, using a pepper pot and CCD camera, was completed on the recently re-installed LIS, measured and analysed to be 140mm.mrad un-normalised and 0.8mm.mrad normalised 4rms for the maximum intensity charge state, Pb27+. A Visual Basic Program was modified to allow Charge State Distribution (CSD) and other scans of the ECRIS at CERN to be taken. Chapter 5 presents the results of the CSD scans taken. This program provided a new method to take 1 dimensional transverse beam profiles. From this a direct emittance measurement was formed for the first time since the source was o...

  2. Comparative genomic analysis of the arthropod muscle myosin heavy chain genes allows ancestral gene reconstruction and reveals a new type of 'partially' processed pseudogene

    Directory of Open Access Journals (Sweden)

    Kollmar Martin

    2008-02-01

    Full Text Available Abstract Background Alternative splicing of mutually exclusive exons is an important mechanism for increasing protein diversity in eukaryotes. The insect Mhc (myosin heavy chain gene produces all different muscle myosins as a result of alternative splicing in contrast to most other organisms of the Metazoa lineage, that have a family of muscle genes with each gene coding for a protein specialized for a functional niche. Results The muscle myosin heavy chain genes of 22 species of the Arthropoda ranging from the waterflea to wasp and Drosophila have been annotated. The analysis of the gene structures allowed the reconstruction of an ancient muscle myosin heavy chain gene and showed that during evolution of the arthropods introns have mainly been lost in these genes although intron gain might have happened in a few cases. Surprisingly, the genome of Aedes aegypti contains another and that of Culex pipiens quinquefasciatus two further muscle myosin heavy chain genes, called Mhc3 and Mhc4, that contain only one variant of the corresponding alternative exons of the Mhc1 gene. Mhc3 transcription in Aedes aegypti is documented by EST data. Mhc3 and Mhc4 inserted in the Aedes and Culex genomes either by gene duplication followed by the loss of all but one variant of the alternative exons, or by incorporation of a transcript of which all other variants have been spliced out retaining the exon-intron structure. The second and more likely possibility represents a new type of a 'partially' processed pseudogene. Conclusion Based on the comparative genomic analysis of the alternatively spliced arthropod muscle myosin heavy chain genes we propose that the splicing process operates sequentially on the transcript. The process consists of the splicing of the mutually exclusive exons until one exon out of the cluster remains while retaining surrounding intronic sequence. In a second step splicing of introns takes place. A related mechanism could be responsible for

  3. Surface mu heavy chain signals down-regulation of the V(D)J-recombinase machinery in the absence of surrogate light chain components.

    Science.gov (United States)

    Galler, Gunther R; Mundt, Cornelia; Parker, Mathew; Pelanda, Roberta; Mårtensson, Inga-Lill; Winkler, Thomas H

    2004-06-07

    Early B cell development is characterized by stepwise, ordered rearrangement of the immunoglobulin (Ig) heavy (HC) and light (LC) chain genes. Only one of the two alleles of these genes is used to produce a receptor, a phenomenon referred to as allelic exclusion. It has been suggested that pre-B cell receptor (pre-BCR) signals are responsible for down-regulation of the VDJH-recombinase machinery (Rag1, Rag2, and terminal deoxynucleotidyl transferase [TdT]), thereby preventing further rearrangement on the second HC allele. Using a mouse model, we show that expression of an inducible muHC transgene in Rag2-/- pro-B cells induces down-regulation of the following: (a) TdT protein, (b) a transgenic green fluorescent protein reporter reflecting endogenous Rag2 expression, and (c) Rag1 primary transcripts. Similar effects were also observed in the absence of surrogate LC (SLC) components, but not in the absence of the signaling subunit Ig-alpha. Furthermore, in wild-type mice and in mice lacking either lambda5, VpreB1/2, or the entire SLC, the TdT protein is down-regulated in muHC+LC- pre-B cells. Surprisingly, muHC without LC is expressed on the surface of pro-/pre-B cells from lambda5-/-, VpreB1-/-VpreB2-/-, and SLC-/- mice. Thus, SLC or LC is not required for muHC cell surface expression and signaling in these cells. Therefore, these findings offer an explanation for the occurrence of HC allelic exclusion in mice lacking SLC components.

  4. Intramolecular trimerization, a novel strategy for making multispecific antibodies with controlled orientation of the antigen binding domains

    DEFF Research Database (Denmark)

    Álvarez-Cienfuegos, Ana; Alanes, Natalia Nuñez del Prado; Compte, Marta

    2016-01-01

    Here, we describe a new strategy that allows the rapid and efficient engineering of mono and multispecific trivalent antibodies. By fusing single-domain antibodies from camelid heavy-chain-only immunoglobulins (VHHs) to the N-terminus of a human collagen XVIII trimerization domain (TIEXVIII) we p...

  5. Endocytosis-independent function of clathrin heavy chain in the control of basal NF-κB activation.

    Directory of Open Access Journals (Sweden)

    Man Lyang Kim

    Full Text Available BACKGROUND: Nuclear factor-κB (NF-κB is a transcription factor that regulates the transcription of genes involved in a variety of biological processes, including innate and adaptive immunity, stress responses and cell proliferation. Constitutive or excessive NF-κB activity has been associated with inflammatory disorders and higher risk of cancer. In contrast to the mechanisms controlling inducible activation, the regulation of basal NF-κB activation is not well understood. Here we test whether clathrin heavy chain (CHC contributes to the regulation of basal NF-κB activity in epithelial cells. METHODOLOGY: Using RNA interference to reduce endogenous CHC expression, we found that CHC is required to prevent constitutive activation of NF-κB and gene expression. Immunofluorescence staining showed constitutive nuclear localization of the NF-κB subunit p65 in absence of stimulation after CHC knockdown. Elevated basal p65 nuclear localization is caused by constitutive phosphorylation and degradation of inhibitor of NF-κB alpha (IκBα through an IκB kinase α (IKKα-dependent mechanism. The role of CHC in NF-κB signaling is functionally relevant as constitutive expression of the proinflammatory chemokine interleukin-8 (IL-8, whose expression is regulated by NF-κB, was found after CHC knockdown. Disruption of clathrin-mediated endocytosis by chemical inhibition or depletion of the μ2-subunit of the endocytosis adaptor protein AP-2, and knockdown of clathrin light chain a (CHLa, failed to induce constitutive NF-κB activation and IL-8 expression, showing that CHC acts on NF-κB independently of endocytosis and CLCa. CONCLUSIONS: We conclude that CHC functions as a built-in molecular brake that ensures a tight control of basal NF-κB activation and gene expression in unstimulated cells. Furthermore, our data suggest a potential link between a defect in CHC expression and chronic inflammation disorder and cancer.

  6. Production, Characterization and Use of Monoclonal Antibodies Recognizing IgY Epitopes Shared by Chicken, Turkey, Pheasant, Peafowl and Sparrow

    OpenAIRE

    Narat, Mojca; Biček, Ajda; Vadnjal, Robert; Benčina, Dušan

    2004-01-01

    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...

  7. Antithyroglobulin antibody

    Science.gov (United States)

    Thyroglobulin antibody; Thyroiditis - thyroglobulin antibody; Hypothyroidism - thyroglobulin antibody; Thyroiditis - thyroglobulin antibody; Graves disease - thyroglobulin antibody; Underactive thyroid - thyroglobulin antibody

  8. A phage-displayed chicken single-chain antibody fused to alkaline phosphatase detects Fusarium pathogens and their presence in cereal grains

    International Nuclear Information System (INIS)

    Hu, Zu-Quan; Li, He-Ping; Zhang, Jing-Bo; Huang, Tao; Liu, Jin-Long; Xue, Sheng; Wu, Ai-Bo; Liao, Yu-Cai

    2013-01-01

    Graphical abstract: A phage-displayed chicken scFv antibody, FvSG7, binds on the surface antigen of conidiospores and the mycelia of F. verticillioides. Its fusion with alkaline phosphatase (AP) through a 218 linker displayed a 4-fold higher affinity compared with the parent scFv antibody and efficiently detected toxigenic Fusarium pathogens in cereal grains. Highlights: ► Generation of a highly reactive scFv antibody against F. verticillioides. ► Localization of the antibody binding to the surface target of F. verticillioides. ► Expression of the antibody–alkaline phosphatase (AP) fusion linked by a 218 linker. ► The antibody–AP fusion has a higher affinity than the parental antibody. ► The antibody–AP fusion detects toxigenic Fusarium pathogens in cereal grains. -- Abstract: Fusarium and its poisonous mycotoxins are distributed worldwide and are of particular interest in agriculture and food safety. A simple analytical method to detect pathogens is essential for forecasting diseases and controlling mycotoxins. This article describes a proposed method for convenient and sensitive detection of Fusarium pathogens that uses the fusion of single-chain variable fragment (scFv) and alkaline phosphatase (AP). A highly reactive scFv antibody specific to soluble cell wall-bound proteins (SCWPs) of F. verticillioides was selected from an immunized chicken phagemid library by phage display. The antibody was verified to bind on the surface of ungerminated conidiospores and mycelia of F. verticillioides. The scFv–AP fusion was constructed, and soluble expression in bacteria was confirmed. Both the antibody properties and enzymatic activity were retained, and the antigen-binding capacity of the fusion was enhanced by the addition of a linker. Surface plasmon resonance measurements confirmed that the fusion displayed 4-fold higher affinity compared with the fusion's parental scFv antibody. Immunoblot analyses showed that the fusion had good binding capacity to

  9. A phage-displayed chicken single-chain antibody fused to alkaline phosphatase detects Fusarium pathogens and their presence in cereal grains

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zu-Quan [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); Li, He-Ping [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Zhang, Jing-Bo [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Huang, Tao [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Liu, Jin-Long; Xue, Sheng [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); Wu, Ai-Bo [Institute for Agri-food Standards and Testing Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products, Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, 1000 Jinqi Road, Shanghai 201403 (China); Liao, Yu-Cai, E-mail: ycliao06@yahoo.com.cn [Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); National Center of Plant Gene Research, Wuhan 430070 (China)

    2013-02-18

    Graphical abstract: A phage-displayed chicken scFv antibody, FvSG7, binds on the surface antigen of conidiospores and the mycelia of F. verticillioides. Its fusion with alkaline phosphatase (AP) through a 218 linker displayed a 4-fold higher affinity compared with the parent scFv antibody and efficiently detected toxigenic Fusarium pathogens in cereal grains. Highlights: ► Generation of a highly reactive scFv antibody against F. verticillioides. ► Localization of the antibody binding to the surface target of F. verticillioides. ► Expression of the antibody–alkaline phosphatase (AP) fusion linked by a 218 linker. ► The antibody–AP fusion has a higher affinity than the parental antibody. ► The antibody–AP fusion detects toxigenic Fusarium pathogens in cereal grains. -- Abstract: Fusarium and its poisonous mycotoxins are distributed worldwide and are of particular interest in agriculture and food safety. A simple analytical method to detect pathogens is essential for forecasting diseases and controlling mycotoxins. This article describes a proposed method for convenient and sensitive detection of Fusarium pathogens that uses the fusion of single-chain variable fragment (scFv) and alkaline phosphatase (AP). A highly reactive scFv antibody specific to soluble cell wall-bound proteins (SCWPs) of F. verticillioides was selected from an immunized chicken phagemid library by phage display. The antibody was verified to bind on the surface of ungerminated conidiospores and mycelia of F. verticillioides. The scFv–AP fusion was constructed, and soluble expression in bacteria was confirmed. Both the antibody properties and enzymatic activity were retained, and the antigen-binding capacity of the fusion was enhanced by the addition of a linker. Surface plasmon resonance measurements confirmed that the fusion displayed 4-fold higher affinity compared with the fusion's parental scFv antibody. Immunoblot analyses showed that the fusion had good binding

  10. Somatic populations of PGT135-137 HIV-1-neutralizing antibodies identified by 454 pyrosequencing and bioinformatics

    Directory of Open Access Journals (Sweden)

    Jiang eZhu

    2012-09-01

    Full Text Available Select HIV-1-infected individuals develop sera capable of neutralizing diverse viral strains. The molecular basis of this neutralization is currently being deciphered by the isolation of HIV-1-neutralizing antibodies. In one infected donor, three neutralizing antibodies, PGT135-137, were identified by assessment of neutralization from individually sorted B cells and found to recognize an epitope containing an N-linked glycan at residue 332 on HIV-1 gp120. Here we use deep sequencing and bioinformatics methods to interrogate the B cell record of this donor to gain a more complete understanding of the humoral immune response. PGT135-137-gene family-specific primers were used to amplify heavy and light chain-variable domain sequences. 454 pyrosequencing produced 141,298 heavy-chain sequences of IGHV4-39 origin and 87,229 light-chain sequences of IGKV3-15 origin. A number of heavy and light chain sequences of ~90% identity to PGT137, several to PGT136, and none of high identity to PGT135 were identified. After expansion of these sequences to include close phylogenetic relatives, a total of 202 heavy-chain sequences and 72 light-chain sequences were identified. These sequences were clustered into populations of 95% identity comprising 15 for heavy chain and 10 for light chain, and a select sequence from each population was synthesized and reconstituted with a PGT137-partner chain. Reconstituted antibodies showed varied neutralization phenotypes for HIV-1 clade A and D isolates. Sequence diversity of the antibody population represented by these tested sequences was notably higher than observed with a 454 pyrosequencing-control analysis on 10 antibodies of defined sequence, suggesting that this diversity results primarily from somatic maturation. Our results thus provide an example of how pathogens like HIV-1 are opposed by a varied humoral immune response, derived from intrinsic mechanisms of antibody development, and embodied by somatic populations

  11. Dlc1 interaction with non-muscle myosin heavy chain II-A (Myh9 and Rac1 activation

    Directory of Open Access Journals (Sweden)

    Mohammad G. Sabbir

    2016-04-01

    Full Text Available The Deleted in liver cancer 1 (Dlc1 gene codes for a Rho GTPase-activating protein that also acts as a tumour suppressor gene. Several studies have consistently found that overexpression leads to excessive cell elongation, cytoskeleton changes and subsequent cell death. However, none of these studies have been able to satisfactorily explain the Dlc1-induced cell morphological phenotypes and the function of the different Dlc1 isoforms. Therefore, we have studied the interacting proteins associated with the three major Dlc1 transcriptional isoforms using a mass spectrometric approach in Dlc1 overexpressing cells. We have found and validated novel interacting partners in constitutive Dlc1-expressing cells. Our study has shown that Dlc1 interacts with non-muscle myosin heavy chain II-A (Myh9, plectin and spectrin proteins in different multiprotein complexes. Overexpression of Dlc1 led to increased phosphorylation of Myh9 protein and activation of Rac1 GTPase. These data support a role for Dlc1 in induced cell elongation morphology and provide some molecular targets for further analysis of this phenotype.

  12. Expression of smooth muscle and non-muscle myosin heavy chain isoforms in cultured vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Rovner, A.S.; Murphy, R.A.; Owens, G.K.

    1986-01-01

    Immunocytochemical studies of cultured smooth muscle cells (SMCs) have disagreed on the nature of myosin expression. This investigation was undertaken to test for the presence of heterogeneous myosin heavy chain (MHC) isoforms in cell culture as a possible explanation for these results. Previously, Rovner et al. detected two MHCs in intact smooth muscles which differed in molecular weight by ca. 4000 daltons (SM1 and SM2) using a 3-4% acrylamide gradient SDS gel system. When sub-confluent primary cultures of rat aorta SMCs were assayed by this system, SM1 and SM2 were seen, along with large amounts of a third, unique MHC, NM, which closely resembled the MHC from human platelet in size and antigenicity. Data from 35 S-methionine autoradiograms showed that the log growth phase SMC cultures were producing almost exclusively NM, but the growth arrest, post-confluent cultures synthesized increased relative amounts of the SM MHC forms and contained comparable amounts of SM1, SM2, and NM. The same patterns of MHC synthesis were seen in sub-passaged SMCs. The expression of the SM-specific forms of myosin in quiescent, post-confluent cultures parallels that of smooth muscle actin suggesting that density induced growth arrest promotes cytodifferentiation in cultured vascular SMCs

  13. Differences in mitochondrial gene expression profiles, enzyme activities and myosin heavy chain types in yak versus bovine skeletal muscles.

    Science.gov (United States)

    Lin, Y Q; Xu, Y O; Yue, Y; Jin, S Y; Qu, Y; Dong, F; Li, Y P; Zheng, Y C

    2012-08-29

    Hypoxia can affect energy metabolism. We examined gene expression and enzyme activity related to mitochondrial energy metabolism, as well as myosin heavy chain (MyHC) types in yaks (Bos grunniens) living at high altitudes. Real-time quantitative PCR assays indicated that the yak has significantly lower levels of carnitine palmitoyltransferase (CPT) mRNA in the biceps femoris and lower levels of uncoupling protein 3 (UCP3) mRNA in both biceps femoris and longissimus dorsi than in Yellow cattle. No significant differences between yak and Yellow cattle were observed in the activities of mitochondrial β-hydroxyacyl-CoA dehydrogenase, isocitrate dehydrogenase and cytochrome oxidase in the same muscles. Semi-quantitative RT-PCR analysis showed that the MyHC 1 mRNA levels in yak biceps femoris was lower than in Yellow cattle. We conclude that the yak has significantly lower mRNA levels of CPT, UCP3, and MyHC 1 in biceps femoris than in Yellow cattle, suggesting that the yak biceps femoris has lower fatty acid oxidation capacity and greater glycolytic metabolic potential.

  14. Characterisation of myosin heavy chain gene variants in the fast and slow muscle fibres of gammarid amphipods.

    Science.gov (United States)

    Whiteley, N M; Magnay, J L; McCleary, S J; Nia, S Khazraee; El Haj, A J; Rock, J

    2010-10-01

    Recent molecular work has revealed a large diversity of myosin heavy chain (MyHC) gene variants in the abdominal musculature of gammarid amphipods. An unusual truncated MyHC transcript from the loop 1 region (Variant A(3)) was consistently observed in multiple species and populations. The current study aimed to determine whether this MyHC variant is specific to a particular muscle fibre type, as a change in net charge to the loop 1 region of Variant A(3) could be functionally significant. The localisation of different fibre types within the abdominal musculature of several gammarid species revealed that the deep flexor and extensor muscles are fast-twitch muscle fibres. The dorsal superficial muscles were identified as slow fibres and the muscles extrinsic to the pleopods were identified as intermediate fibres. Amplification of loop 1 region mRNA from isolated superficial extensor and deep flexor muscles, and subsequent liquid chromatography and sequence analysis revealed that Variant A(3) was the primary MyHC variant in slow muscles, and the conserved A(1) sequence was the primary variant in fast muscles. The specific role of Variant A(3) in the slow muscles remains to be investigated. 2010 Elsevier Inc. All rights reserved.

  15. MR molecular imaging of tumours using ferritin heavy chain reporter gene expression mediated by the hTERT promoter

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yan [Third Military Medical University, Department of Radiology, XinQiao Hospital, ChongQing (China); The First Affiliated Hospital of ChengDu Medical College, Department of Radiology, ChengDu (China); Gong, Ming-fu; Yang, Hua; Zhang, Song; Wang, Guang-xian; Su, Tong-sheng; Wen, Li; Zhang, Dong [Third Military Medical University, Department of Radiology, XinQiao Hospital, ChongQing (China)

    2016-11-15

    Using the human telomerase reverse transcriptase (hTERT) promoter and the modified ferritin heavy chain (Fth) reporter gene, reporter gene expression for MRI was examined in telomerase positive and negative tumour cells and xenografts. Activity of the reporter gene expression vector Lenti-hTERT-Fth1-3FLAG-Puro was compared to constitutive CMV-driven expression and to the untransfected parental control in five tumour cell lines: A549, SKOV3, 293T, U2OS and HPDLF. In vitro, transfected cells were evaluated for FLAG-tagged protein expression, iron accumulation and transverse relaxation. In vivo, tumours transduced by lentiviral vector injection were imaged using T2*WI. Changes in tumour signal intensity were validated by histology. Only telomerase positive tumour cells expressed FLAG-tagged Fth and displayed an increase in R2* above the parental control, with a corresponding change in T2*WI. In addition, only telomerase positive tumours, transduced by injection of the reporter gene expression construct, exhibited a change in signal intensity on T2*WI. Tumour histology verified the expression of FLAG-tagged Fth and iron accumulation in telomerase positive tissue. Reporter gene expression for MRI, using the Fth reporter and the hTERT promoter, may be a useful strategy for the non-invasive diagnosis of many types of cancer. (orig.)

  16. A mechanical comparison of linear and double-looped hung supplemental heavy chain resistance to the back squat: a case study.

    Science.gov (United States)

    Neelly, Kurt R; Terry, Joseph G; Morris, Martin J

    2010-01-01

    A relatively new and scarcely researched technique to increase strength is the use of supplemental heavy chain resistance (SHCR) in conjunction with plate weights to provide variable resistance to free weight exercises. The purpose of this case study was to determine the actual resistance being provided by a double-looped versus a linear hung SHCR to the back squat exercise. The linear technique simply hangs the chain directly from the bar, whereas the double-looped technique uses a smaller chain to adjust the height of the looped chain. In both techniques, as the squat descends, chain weight is unloaded onto the floor, and as the squat ascends, chain weight is progressively loaded back as resistance. One experienced and trained male weight lifter (age = 33 yr; height = 1.83 m; weight = 111.4 kg) served as the subject. Plate weight was set at 84.1 kg, approximately 50% of the subject's 1 repetition maximum. The SHCR was affixed to load cells, sampling at a frequency of 500 Hz, which were affixed to the Olympic bar. Data were collected as the subject completed the back squat under the following conditions: double-looped 1 chain (9.6 kg), double-looped 2 chains (19.2 kg), linear 1 chain, and linear 2 chains. The double-looped SHCR resulted in a 78-89% unloading of the chain weight at the bottom of the squat, whereas the linear hanging SHCR resulted in only a 36-42% unloading. The double-looped technique provided nearly 2 times the variable resistance at the top of the squat compared with the linear hanging technique, showing that attention must be given to the technique used to hang SHCR.

  17. Detection of clonal B cells in microdissected reactive lymphoproliferations: possible diagnostic pitfalls in PCR analysis of immunoglobulin heavy chain gene rearrangement

    DEFF Research Database (Denmark)

    Zhou, X.G.; Sandvej, K.; Gregersen, Niels

    1999-01-01

    Aims-To evaluate the specificity of standard and fluorescence based (GENESCAN) polymerase chain reaction (PCR) immunoglobulin heavy chain (IgH) gene rearrangement analysis in complete and microdissected paraffin wax embedded sections from lymphoid proliferations. Methods-PCR IgH gene rearrangement...... because of preferential priming or detection of local B cell clones. Data from clonal analysis of small, microdissected or lymphocyte poor samples must be evaluated critically. It is recommended that analyses should be run in parallel on at least two tissue specimens. Only reproducible bands present...

  18. Distribution of fast myosin heavy chain-based muscle fibres in the gluteus medius of untrained horses: mismatch between antigenic and ATPase determinants

    Science.gov (United States)

    LINNANE, LINDA; SERRANO, A. L.; RIVERO, J. L. L.

    1999-01-01

    The distribution of muscle fibres classified on the basis of their content of different myosin heavy chain (MHC) isoforms was analysed in muscle biopsies from the gluteus medius of adult untrained horses by correlating immunohistochemistry with specific anti-MHC monoclonal antibodies and standard myofibrillar ATPase (mATPase) histochemistry. Percutaneous needle biopsies were taken at 3 depths (20, 40 and 60 mm) from 4 4-y-old Andalusian stallions. The percentage of ‘pure’ I MHC fibres increased whereas that for pure IIX MHC fibres decreased from the most superficial to the deepest sampling site. Within the fast fibres, types IIA and IIAX MHC-classified fibres were proportionately more abundant in the deepest sampling site than in the superficial region of the muscle. The immunohistochemical and histochemical characterisation of a large number of single fibres (n=1375) was compared and correlated on a fibre-to-fibre basis. The results showed that 40% of the fibres analysed were pure type I (expressing only MHC-I); they showed correct matching between their antigenic and mATPase determinants. In contrast, within the fast fibres, a considerable proportion of fibres were found showing a mismatch between their immunohistochemical and mATPase profiles. The most common mismatched fibre phenotypes comprised fibres displaying coexpression of both fast MHCs when analysed by immunocytochemistry, but showing an mATPase profile similar to typical IIX fibres (moderate mATPase reaction after preincubation at pH 4.4). Considered altogether, the total mismatched fibres represented only 4.2% of the whole fast fibre population in the superficial region of the muscle, but their proportion increased to 15.6% and 38.4% in the middle and deep regions, respectively, of gluteus medius. It is concluded that a considerable number of hybrid fast MHC IIAX fibres are present in the gluteus medius of untrained horses, suggesting that equine type II fibres have probably been misclassified in

  19. Radioimmunoassay of myosin heavy beta chains in human serum for the evaluation of the size of myocardial infarction: correlation with myocardial Tl-201 SPECT and cardiac angioscintigraphy

    International Nuclear Information System (INIS)

    Facello, A.; Gries, P.; Demangeat, C.; Brunot, B.; Roul, G.; Demangeat, J.L.; Moulichon, M.; Bareiss, P.; Sacrez, A.; Constantinesco, A.

    1990-01-01

    To determine the relationship between serum levels of myosin heavy beta chains assessed by an IRMA technique and other radionuclide and enzymatic parameters in the evaluation of the size of myocardial infarction, we studied 22 patients with acute myocardial infarction. Blood samples taken daily between 1st to 13th day of evolution allow the determination of peak and integral of myosine release that showed a good correlation (p [fr

  20. A human/mouse chimeric monoclonal antibody against intercellular adhesion molecule-1 for tumor radioimmunoimaging

    International Nuclear Information System (INIS)

    Yamamura, Miyuki; Hinoda, Yuji; Sasaki, Shigeru; Tsujisaki, Masayuki; Imai, Kohzoh; Oriuchi, Noboru; Endo, Keigo.

    1996-01-01

    A mouse-human chimeric antibody for intercellular adhesion molecule-1 (ICAM-1) was established by using heavy chain loss mouse mutant hybridoma and human immunoglobulin expression vector. The HA58 hybridoma secreted anti-ICAM-1 monoclonal antibody (MoAb) (IgG1,κ). The gene of the mouse variable region of heavy chain was amplified and cloned by the polymerase chain reaction technique directly from the HA58 hybridoma RNA. The variable region of heavy chain was joined with an expression vector which contains human γ1 constant gene. The expression vector was transfected into heavy chain loss mutant cells HA58-7, which produced only murine immunoglobulin light chains. The resultant chimeric MoAb HA58, chHA58, retained full-binding reactivity to ICAM-1 compared with murine HA58 parental antibody. The chimeric MoAb chHA58 showed little antibody dependent cell-mediated cytotoxic activity against cultured tumor cells. Biodistribution studies with 99m Tc-labeled chHA58 in nude mice bearing human gastric carcinoma JRST cells, demonstrated that the tumor-blood ratio was 1.55 at 18 h after injection, when the tumors were clearly visible in gamma scintigraphy. These data suggest that chHA58 may be of practical use for radioimmunoimaging of a wide variety of tumors. (author)

  1. Cold exposure increases slow-type myosin heavy chain 1 (MyHC1) composition of soleus muscle in rats.

    Science.gov (United States)

    Mizunoya, Wataru; Iwamoto, Yohei; Sato, Yusuke; Tatsumi, Ryuichi; Ikeuchi, Yoshihide

    2014-03-01

    The aim of this study was to examine the effects of cold exposure on rat skeletal muscle fiber type, according to myosin heavy chain (MyHC) isoform and metabolism-related factors. Male Wistar rats (7 weeks old) were housed individually at 4 ± 2°C as a cold-exposed group or at room temperature (22 ± 2°C) as a control group for 4 weeks. We found that cold exposure significantly increased the slow-type MyHC1 content in the soleus muscle (a typical slow-type fiber), while the intermediate-type MyHC2A content was significantly decreased. In contrast to soleus, MyHC composition of extensor digitorum longus (EDL, a typical fast-type fiber) and gastrocnemius (a mix of slow-type and fast-type fibers) muscle did not change from cold exposure. Cold exposure increased mRNA expression of mitochondrial uncoupling protein 3 (UCP3) in both the soleus and EDL. Cold exposure also increased mRNA expression of myoglobin, peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) and forkhead box O1 (FOXO1) in the soleus. Upregulation of UCP3 and PGC1α proteins were observed with Western blotting in the gastrocnemius. Thus, cold exposure increased metabolism-related factors in all muscle types that were tested, but MyHC isoforms changed only in the soleus. © 2013 Japanese Society of Animal Science.

  2. Tumor necrosis factor-α attenuates starvation-induced apoptosis through upregulation of ferritin heavy chain in hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Kou, Xingrui; Zhao, Qiudong; Zhao, Xue; Li, Rong; Wei, Lixin; Wu, Mengchao; Jing, Yingying; Deng, Weijie; Sun, Kai; Han, Zhipeng; Ye, Fei; Yu, Guofeng; Fan, Qingmin; Gao, Lu

    2013-01-01

    Tumor microenviroment is characteristic of inflammation, ischemia and starvation of nutrient. TNF-α, which is an extraordinarily pleiotropic cytokine, could be an endogenous tumor promoter in some tumor types. The basic objective of this study was to investigate the effects of TNF-α on the cell viability and apoptosis of hepatocellular carcinoma cells under serum starvation, and to identify the molecular mechanisms involved. For this purpose, five different concentrations of TNF-α and two different serum settings (serum-cultured and serum-deprived) were used to investigate the effects of TNF-α on the cell viability and apoptosis of Hep3B and SMMC-7721 cells. TNF-α (10 ng/ml) attenuated serum starvation-induced apoptosis of hepatocellular carcinoma cells, and autophagy conferred this process. BAY11-7082, a specific inhibitor of NF-κB, reversed the suppression of serum starvation-induced apoptosis by TNF-α. Moreover, TNF-α-induced NF-κB transactivation was suppressed by autophagy inhibitor 3-MA. In addition, TNF-α up-regulated Ferritin heavy chain (FHC) transiently by NF-κB activation and FHC levels were correlated with the TNF-α-induced protection against serum starvation-mediated apoptosis of hepatocellular carcinoma cells. Furthermore, FHC-mediated inhibition of apoptosis depended on suppressing ROS accumulation. Our findings suggested that autophagy conferred the TNF-α protection against serum starvation-mediated apoptosis of hepatocellular carcinoma cells, the mechanism involved with the activation of the TNF-α/ NF-κB /FHC signaling pathway

  3. Cloning of skeletal myosin heavy chain gene family from adult pleopod muscle and whole larvae of shrimps.

    Science.gov (United States)

    Koyama, Hiroki; Piyapattanakorn, Sanit; Watabe, Shugo

    2013-06-01

    The physiological and biological properties of skeletal muscle in crustacea have not been well understood compared with those of vertebrates. The present study focused on myosin, the major protein in skeletal muscle, from shrimps. In our previous study, two full-length genes encoding myosin heavy chain (MHC), a large subunit of the myosin molecule, were cloned from abdominal fast skeletal muscle of kuruma Marsupenaeus japonicus, black tiger Penaeus monodon and Pacific white Penaeus vannamei shrimps, and named as MHCa and MHCb. In this study, we renamed these as MHC1 and MHC2, respectively, due to the presence of various isoforms newly identified. Partial MHC sequences were identified from pleopod muscle of these shrimps. Two MHCs, named MHC3 and MHC4, were identified from pleopod muscle of kuruma shrimp, whereas two MHCs, named MHC4 and MHC5, were cloned from Pacific white shrimp pleopod. MHC3 was cloned only from black tiger shrimp pleopod. Partial MHC sequences from zoea, mysis, and postlarvae of black tiger and Pacific white shrimps were also determined. The phylogenetic tree demonstrated that most MHCs from pleopod muscle and larval MHCs formed clades with MHC1 and MHC2, respectively. These MHCs were considered to be of fast type, since MHC1 and MHC2 are fast-type MHCs according to our previous study. MHC5 obtained from pleopod muscle of Pacific white shrimp in this study was monophyletic with American lobster Homarus americanus S2 slow tonic MHC previously reported, indicating that MHC5 from Pacific white shrimp is of slow type. Copyright © 2013 Wiley Periodicals, Inc.

  4. [The value of serum heavy/light chain immunoassay to assess therapeutic response in patients with multiple myeloma].

    Science.gov (United States)

    Yu, X C; Su, W; Zhuang, J L

    2018-04-14

    Objective: To assess the value of immunoglobulin heavy/light chain (HLC) immunoassay on therapeutic response in patients with multiple myeloma(MM). Methods: A total of 45 newly diagnosed MM patients were retrospectively enrolled in Peking Union Medical College Hospital from 2013 to 2016, whose 115 serum samples were consecutively collected. HLC was tested to evaluate response and compare with other methods for M protein detection. Results: ①There were 30 males and 15 females in total of whom the monoclonal immunoglobulin was IgG in 27 (IgGκ∶IgGλ 12∶15) and IgA (IgAκ∶IgAλ 9∶9) in 18. The arerage age of the studied population was 59 (range 43-80) . ② In 34 patients with serum sample at diagnosis, 32 (94.1%) had abnormal HLC ratio (rHLC) while 2 patients with IgG had normal rHLC. The percentages of abnormal rHLC was 81.8% (18/22) at partial response、50.0%(9/18) at very good complete response and 16.0%(4/25) at complete response. ③In 25 patients reaching CR, there were 13 with IgG and 12 with IgA. 4 patients equally split of IgG and IgA had abnormal rHLC at complete response. ④By monitoring the rHLC of some patients consecutively, we found that the remission of rHLC was to some extent behind the remission of SPE and IEF, or even rFLC. Conclusion: Immunoglobulin HLC detection is one feasible method for minimal residual disease detection.

  5. Thyroid hormone partially corrects the effect of diabetes on mysoin heavy chain RNAs in the rat ventricle

    International Nuclear Information System (INIS)

    Barrieux, A.; Dillmann, W.H.

    1986-01-01

    The relative abundance of the 2 cardiac myosin heavy chains (MHH-α and MHC-β) and their corresponding RNAs is similarly affected by hypothyroidism and diabetes in the rat ventricle. Since circulating levels of thyroid hormone (T 3 ) are significantly decreased in diabetes the decreased RNA-α and increased RNA-β associated with diabetes may be related to T 3 deficiency. Chronically diabetic rats were injected with T 3 , insulin (I), or both and sacrificed between 1 and 12 hrs after injection, MHC RNA was quantified by hybridization of total RNA to a [ 32 P]-cDNA MHC-α probe. Total MHC RNA was measured by retention of S1-resistant label on DE-81 while RNA-α and RNA-β were quantified by separation of intact (α) and partially digested (β) probe by gel electrophoresis. Total MHC RNA was not changed by T 3 or I (.9-1.2 ng/μg of cellular RNA). T 3 and I elicited a very rapid increase in RNA-α (18% in untreated to 38% (I) and 47% (T 3 within 1 hr). I administered either 7 hr before or 1 hr after T 3 did not modify the RNA-α increase observed after T 3 alone. However, the response of diabetic rats to T 3 was markedly different from that of hypothyroid rats. Conclusions: 1) T 3 in diabetic rats does not mimick the effect of T 3 in hypothyroid rats; it may simply impose a hyperthyroid state on the existing diabetes and 2) since neither T 3 nor I are able to increase RNA-α to control levels within 12 hrs, neither hormone is sufficient to regulate the expression of MHC RNAs

  6. Baculovirus display of functional antibody Fab fragments.

    Science.gov (United States)

    Takada, Shinya; Ogawa, Takafumi; Matsui, Kazusa; Suzuki, Tasuku; Katsuda, Tomohisa; Yamaji, Hideki

    2015-08-01

    The generation of a recombinant baculovirus that displays antibody Fab fragments on the surface was investigated. A recombinant baculovirus was engineered so that the heavy chain (Hc; Fd fragment) of a mouse Fab fragment was expressed as a fusion to the N-terminus of baculovirus gp64, while the light chain of the Fab fragment was simultaneously expressed as a secretory protein. Following infection of Sf9 insect cells with the recombinant baculovirus, the culture supernatant was analyzed by enzyme-linked immunosorbent assay using antigen-coated microplates and either an anti-mouse IgG or an anti-gp64 antibody. A relatively strong signal was obtained in each case, showing antigen-binding activity in the culture supernatant. In western blot analysis of the culture supernatant using the anti-gp64 antibody, specific protein bands were detected at an electrophoretic mobility that coincided with the molecular weight of the Hc-gp64 fusion protein as well as that of gp64. Flow cytometry using a fluorescein isothiocyanate-conjugated antibody specific to mouse IgG successfully detected the Fab fragments on the surface of the Sf9 cells. These results suggest that immunologically functional antibody Fab fragments can be displayed on the surface of baculovirus particles, and that a fluorescence-activated cell sorter with a fluorescence-labeled antigen can isolate baculoviruses displaying specific Fab fragments. This successful baculovirus display of antibody Fab fragments may offer a novel approach for the efficient selection of specific antibodies.

  7. Breakpoint of an inversion of chromosome 14 in a T-cell leukemia: sequences downstream of the immunoglobulin heavy chain locus are implicated in tumorigenesis

    International Nuclear Information System (INIS)

    Baer, R.; Heppell, A.; Taylor, A.M.R.; Rabbitts, P.H.; Boullier, B.; Rabbitts, T.H.

    1987-01-01

    T-cell tumors are characterized by inversions or translocations of chromosome 14. The breakpoints of these karyotypic abnormalities occur in chromosome bands 14q11 and 14q32 - the same bands in which the T-cell receptor (TCR) α-chain and immunoglobulin heavy chain genes have been mapped, respectively. Patients with ataxia-telangiectasia are particularly prone to development of T-cell chronic lymphocytic leukemia with such chromosomal abnormalities. The authors describe DNA rearrangements of the TCR α-chain gene in an ataxia-telangiectasia-associated leukemia containing both a normal and an inverted chromosome 14. The normal chromosome 14 has undergone a productive join of TCR α-chain variable (V/sub α/) and joining (J/sub α/) gene segments. The other allele of the TCR α-chain gene features a DNA rearrangement, about 50 kilobases from the TCR α-chain constant (C/sub α/) gene, that represents the breakpoint of the chromosome 14 inversion; this breakpoint is comprised of a TCR J/sub α/) segment (from 14q11) fused to sequences derived from 14q32 but on the centromeric side of C/sub μ/. These results imply that 14q32 sequences located at an undetermined distance downstream of immunoglobulin C/sub μ/ locus can contribute to the development of T-cell tumors

  8. Identification of a second T-cell antigen receptor in human and mouse by an anti-peptide γ-chain-specific monoclonal antibody

    International Nuclear Information System (INIS)

    Ioannides, C.G.; Itoh, K.; Fox, F.E.; Pahwa, R.; Good, R.A.; Platsoucas, C.D.

    1987-01-01

    The authors developed a monoclonal antibody (mAb) (9D7) against a synthetic peptide (P13K) selected from the deduced amino acid sequence of the constant region of the λ chain of the murine T-cell antigen receptor (TCR) (amino acids 118-130). Using this mAb, they identified a putative second TCR expressed on peripheral blood lymphocytes from a patient with severe combined immunodeficiency (SCID) that were propagated in culture with recombinant interleukin 2 (rIL-2) and Con A. This mAb immunoprecipitated two polypeptide chains of 40 and 58 kDa under nonreducing conditions and of 40 and 56 kDa under reducing conditions from 125 I-labeled denatured lysates of T3 + WT31 - lymphocytes expanded in culture from a SCID patient. Chemical crosslinking of 125 I-labeled cells followed by immunoprecipitation with anti-Leu-4 mAb under nonreducing or reducing conditions revealed that the 40- and 56-kDa polypeptide chains were associated with the T3 differentiation antigen. These experiments were done with polyclonal cell populations. Cloned T3 + WT31 - cell populations are required to determine whether the TCR contains two λ polypeptide chains. Using the same 9D7 anti-P18K mAb and immunoblotting analysis, they identified a 35 kDa γ-chain polypeptide under reducing conditions expressed on purified L3T4 - Lyt2 - BALB/c mouse thymocytes. This γ-chain TCR is disulfide linked and has a molecular mass of 80 kDa under nonreducing conditions

  9. Cloning of cDNAs coding for the heavy chain region and connecting region of human factor V, a blood coagulation factor with four types of internal repeats

    International Nuclear Information System (INIS)

    Kane, W.H.; Ichinose, A.; Hagen, F.S.; Davie, E.W.

    1987-01-01

    Human factor V is a high molecular weight plasma glycoprotein that participates as a cofactor in the conversion of prothrombin to thrombin by factor X/sub a/. Prior to its participation in the coagulation cascade, factor V is converted to factor V/sub a/ by thrombin generating a heavy chain and a light chain, and these two chains are held together by calcium ions. A connecting region originally located between the heavy and light chains is liberated during the activation reaction. In a previous study, a cDNA of 2970 nucleotides that codes for the carboxyl-terminal 938 amino acids of factor V was isolated and characterized from a Hep G2 cDNA library. This cDNA has been used to obtain additional clones from Hep G2 and human liver cDNA libraries. Furthermore, a Hep G2 cDNA library prepared with an oligonucleotide from the 5' end of these cDNAs was screened to obtain overlapping cDNA clones that code for the amino-terminal region of the molecule. The composite sequence of these clones spans 6911 nucleotides and is consistent with the size of the factor V message present in Hep G2 cells (approximately 7 kilobases). The cDNA codes for a leader sequence of 28 amino acids and a mature protein of 2196 amino acids. The amino acid sequence predicted from the cDNA was in complete agreement with 139 amino acid residues that were identified by Edman degradation of cyanogen bromide peptides isolated from the heavy chain region and connecting region of plasma factor V. The domain structure of human factor V is similar to that previously reported for human coagulation factor VIII. Two types of tandem repeats (17 and 9 amino acids) have also been identified in the connecting region of factor V. The present data indicate that the amino acid sequence in the heavy and light chain regions of factor V is ∼ 40% identical with the corresponding regions of factor VIII

  10. Molecular cloning of complementary DNAs encoding the heavy chain of the human 4F2 cell-surface antigen: a type II membrane glycoprotein involved in normal and neoplastic cell growth

    International Nuclear Information System (INIS)

    Quackenbush, E.; Clabby, M.; Gottesdiener, K.M.; Barbosa, J.; Jones, N.H.; Strominger, J.L.; Speck, S.; Leiden, J.M.

    1987-01-01

    Complementary DNA (cDNA) clones encoding the heavy chain of the heterodimeric human membrane glycoprotein 4F2 have been isolated by immunoscreening of a λgt11 expression library. The identity of these clones has been confirmed by hybridization to RNA and DNA prepared from mouse L-cell transfectants, which were produced by whole cell gene transfer and selected for cell-surface expression of the human 4F2 heavy chain. DNA sequence analysis suggest that the 4F2 heavy-chain cDNAs encode an approximately 526-amino acid type II membrane glycoprotein, which is composed of a large C-terminal extracellular domain, a single potential transmembrane region, and a 50-81 amino acid N-terminal intracytoplasmic domain. Southern blotting experiments have shown that the 4F2 heavy-chain cDNAs are derived from a single-copy gene that has been highly conserved during mammalian evolution

  11. The use of a cocktail of single chain Fv antibody fragments to improve the in vitro and in vivo targeting of melanoma

    International Nuclear Information System (INIS)

    Pacifico, M.D.; Pearl, R.A.; Kupsch, J.M.

    2006-01-01

    Radio scintigraphy using single chain antibody fragments (scFvs) offers a potenti al means of early detection of melanoma metastases. However, previous studies have shown suboptimal levels of tumour localization and nonspecific background accumulation which may be due to antigen heterogeneity. We aimed to improve tumour localization by using a cocktail of different scFvs targeting different epitopes on melanoma cells. We have previously developed three scFvs against distinct and highly tumour-specific melanoma cell-surface antigens by chain shuffling and antibody phage selection on melanoma cells. Three scFvs, RAFT3, B3 and B4 were labeled with 1 25I odine and tested both individually and as a cocktail in a nude mouse xenograft model far human melanoma. Results demonstrated improved tumour localization in vivo when compared to the individual scFvs. Tumour uptake of the cocktail at l hour was 24.220% ID/g (injected dose/gram) compared with 2.854%, 2.263% and 1.355% far B4, RAFT3 and B3, respectively, when injected individually. In addition, the cocktail exhibited significantly superior tumour to normal tissue ratios far muscle and spleen (p<0.05). A combination or cocktail of scFv clones may have an advantage aver individual scFvs far melanoma targeting in patients because of heterogeneity in the expression of different epitopes of antigens on melanoma cells

  12. Generation of high-affinity, internalizing anti-FGFR2 single-chain variable antibody fragment fused with Fc for targeting gastrointestinal cancers.

    Science.gov (United States)

    Borek, Aleksandra; Sokolowska-Wedzina, Aleksandra; Chodaczek, Grzegorz; Otlewski, Jacek

    2018-01-01

    Fibroblast growth factor receptors (FGFRs) are promising targets for antibody-based cancer therapies, as their substantial overexpression has been found in various tumor cells. Aberrant activation of FGF receptor 2 (FGFR2) signaling through overexpression of FGFR2 and/or its ligands, mutations, or receptor amplification has been reported in multiple cancer types, including gastric, colorectal, endometrial, ovarian, breast and lung cancer. In this paper, we describe application of the phage display technology to produce a panel of high affinity single chain variable antibody fragments (scFvs) against the extracellular ligand-binding domain of FGFR2 (ECD_FGFR2). The binders were selected from the human single chain variable fragment scFv phage display libraries Tomlinson I + J and showed high specificity and binding affinity towards human FGFR2 with nanomolar KD values. To improve the affinity of the best binder selected, scFvF7, we reformatted it to a bivalent diabody format, or fused it with the Fc region (scFvF7-Fc). The scFvF7-Fc antibody construct presented the highest affinity for FGFR2, with a KD of 0.76 nM, and was selectively internalized into cancer cells overexpressing FGFR2, Snu-16 and NCI-H716. Finally, we prepared a conjugate of scFvF7-Fc with the cytotoxic drug monomethyl-auristatin E (MMAE) and evaluated its cytotoxicity. The conjugate delivered MMAE selectively to FGFR2-positive tumor cells. These results indicate that scFvF7-Fc-vcMMAE is a highly potent molecule for the treatment of cancers with FGFR2 overexpression.

  13. Responses of Myosin Heavy Chain Phenotypes and Gene Expressions in Neck Muscle to Micro- an Hyper-Gravity in Mice

    Science.gov (United States)

    Ohira, Tomotaka; Ohira, Takashi; Kawano, F.; Shibaguchi, T.; Okabe, H.; Ohno, Y.; Nakai, N.; Ochiai, T.; Goto, K.; Ohira, Y.

    2013-02-01

    Neck muscles are known to play important roles in the maintenance of head posture against gravity. However, it is not known how the properties of neck muscle are influenced by gravity. Therefore, the current study was performed to investigate the responses of neck muscle (rhomboideus capitis) in mice to inhibition of gravity and/or increase to 2-G for 3 months to test the hypothesis that the properties of neck muscles are regulated in response to the level of mechanical load applied by the gravitational load. Three male wild type C57BL/10J mice (8 weeks old) were launched by space shuttle Discovery (STS-128) and housed in Japanese Experimental Module “KIBO” on the International Space Station in mouse drawer system (MDS) project, which was organized by Italian Space Agency. Only 1 mouse returned to the Earth alive after 3 months by space shuttle Atlantis (STS-129). Neck muscles were sampled from both sides within 3 hours after landing. Cage and laboratory control experiments were also performed on the ground. Further, 3-month ground-based control experiments were performed with 6 groups, i.e. pre-experiment, 3-month hindlimb suspension, 2-G exposure by using animal centrifuge, and vivarium control (n=5 each group). Five mice were allowed to recover from hindlimb suspension (including 5 cage control) for 3 months in the cage. Neck muscles were sampled bilaterally before and after 3-month suspension and 2-G exposure, and at the end of 3-month ambulation recovery. Spaceflight-associated shift of myosin heavy chain phenotype from type I to II and atrophy of type I fibers were observed. In response to spaceflight, 17 genes were up-regulated and 13 genes were down-regulated vs. those in the laboratory control. Expression of 6 genes were up-regulated and that of 88 genes were down-regulated by 3-month exposure to 2-G vs. the age-matched cage control. In response to chronic hindlimb suspension, 4 and 20 genes were up- or down-regulated. Further, 98 genes responded

  14. Discovery and characterization of antibody variants using mass spectrometry-based comparative analysis for biosimilar candidates of monoclonal antibody drugs.

    Science.gov (United States)

    Li, Wenhua; Yang, Bin; Zhou, Dongmei; Xu, Jun; Ke, Zhi; Suen, Wen-Chen

    2016-07-01

    Liquid chromatography mass spectrometry (LC-MS) is the most commonly used technique for the characterization of antibody variants. MAb-X and mAb-Y are two approved IgG1 subtype monoclonal antibody drugs recombinantly produced in Chinese hamster ovary (CHO) cells. We report here that two unexpected and rare antibody variants have been discovered during cell culture process development of biosimilars for these two approved drugs through intact mass analysis. We then used comprehensive mass spectrometry-based comparative analysis including reduced light, heavy chains, and domain-specific mass as well as peptide mapping analysis to fully characterize the observed antibody variants. The "middle-up" mass comparative analysis demonstrated that the antibody variant from mAb-X biosimilar candidate was caused by mass variation of antibody crystalline fragment (Fc), whereas a different variant with mass variation in antibody antigen-binding fragment (Fab) from mAb-Y biosimilar candidate was identified. Endoproteinase Lys-C digested peptide mapping and tandem mass spectrometry analysis further revealed that a leucine to glutamine change in N-terminal 402 site of heavy chain was responsible for the generation of mAb-X antibody variant. Lys-C and trypsin coupled non-reduced and reduced peptide mapping comparative analysis showed that the formation of the light-heavy interchain trisulfide bond resulted in the mAb-Y antibody variant. These two cases confirmed that mass spectrometry-based comparative analysis plays a critical role for the characterization of monoclonal antibody variants, and biosimilar developers should start with a comprehensive structural assessment and comparative analysis to decrease the risk of the process development for biosimilars. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Antiproliferative and apoptotic effects of a specific anti-insulin-like growth factor I receptor single chain antibody on breast cancer cells.

    Science.gov (United States)

    Motallebnezhad, Morteza; Younesi, Vahid; Aghebati-Maleki, Leili; Nickho, Hamid; Safarzadeh, Elham; Ahmadi, Majid; Movassaghpour, Ali Akbar; Hosseini, Ahmad; Yousefi, Mehdi

    2016-11-01

    Insulin-like growth factor I receptor (IGF-IR) is expressed on breast cancer cells and involves in metastasis, survival, and proliferation. Currently, application of IGF-IR-targeting monoclonal antibodies (mAbs), alone or in combination with other drugs, is a promising strategy for breast cancer therapy. Single-chain fragment variable (scFv) antibodies have been introduced as appropriate tools for tumor-targeting purposes because of their advantages over whole antibodies. In the present study, we employed a naïve phage library and isolated scFvs against a specific epitope from extracellular domain of IGF-IR by panning process. The selected scFvs were further characterized using polyclonal and monoclonal phage ELISA, soluble monoclonal ELISA, and colony PCR and sequencing. Antiproliferative and apoptotic effects of selected scFv antibodies on breast cancer cell lines were also evaluated by MTT and Annexin V/PI assays. The results of ELISA indicated specific reactions of the isolated scFvs against the IGF-IR peptide, and analyses of PCR product and sequencing confirmed the presence of full length V H and Vκ inserts. Treatment of MCF7 and SKBR3 cells with anti-IGF-IR scFv led to a significant growth inhibition. The results also showed that scFv treatment significantly augmented trastuzumab growth inhibitory effects on SKBR3 cells. The percentage of the apoptotic MCF7 and SKBR3 cells after 24-h treatment with scFv was 39 and 30.70 %, respectively. Twenty-four-hour treatment with scFv in combination with trastuzumab resulted in 44.75 % apoptosis of SKBR3 cells. Taken together, our results demonstrate that the targeting of IGF-IR by scFv can be an effective strategy in the treatment of breast cancer and provide further evidence for effectiveness of dual targeting of HER2 and IGF-IR in breast cancer therapy.

  16. Modified human beta 2-microglobulin (desLys(58)) displays decreased affinity for the heavy chain of MHC class I and induces nitric oxide production and apoptosis

    DEFF Research Database (Denmark)

    Wang, M; Harhaji, L; Lamberth, K

    2009-01-01

    Beta2-microglobulin (beta2m) is the light chain of major histocompatibility complex class I (MHC-I) molecules, and is a prerequisite for the binding of peptides to the heavy chain and their presentation to CD8+ T cells. beta2m can be modified in vivo and in vitro by proteolytic cleavage...... by complement C1 and subsequent carboxypeptidase B-like activity--processes that lead to the generation of desLys(58) beta2m (dbeta2m). This work aims to study the effect of dbeta2m on peptide binding to MHC-I, the influence of dbeta2m on the binding of beta2m to the MHC-I heavy chain and the biological...... activity of dbeta2m. Both beta2m and dbeta2m are able to support the generation of MHC-I/peptide complexes at 18 degrees C, but complexes formed in the presence of dbeta2m destabilize at 37 degrees C. Moreover, a 250 times higher concentration of dbeta2m than of beta2m is needed to displace MHC...

  17. Construction of a Single Chain Variable Fragment Antibody (scFv) against Carbaryl and Its Interaction with Carbaryl.

    Science.gov (United States)

    Xiuyuan, Zhang; Zhihong, Huang; Lixia, Wang; Xiaonan, Liu

    2015-05-01

    Carbaryl is a low molecular weight insecticide that inhibits cholinesterase. Residues of carbaryl in food and the environment have damaged human health. A high-specificity scFv that can identify carbaryl is still lacking. In the present study, an anti-carbaryl scFv gene was prepared by cloning VL and VH genes from hybridoma cells secreting monoclonal antibody, then VH and VL were fused together using splicing by overlap extension (SOE) PCR with a flexible polypeptide linker connector (Gly4Ser)3, and then the scFv-pET-26b recombinant plasmid was constructed and transformed into E. coli BL21 for expression using IPTG as an inducer. The expressed recombinant protein was identified by SDS-PAGE and ELISA. The three-dimensional structure of the anti-carbaryl scFv was constructed by computer modeling, and carbaryl was docked to the scFv model to obtain the structure of the binding complex. The binding site was composed of Ala51, Ser52, Ile51, Gly54, Ser56, Arg98, and Gly100. This helps to understand the mechanism of interaction between anti-carbaryl antibody and antigen. Furthermore, it provides guidance for in vitro affinity maturation of anti-carbaryl antibody.

  18. Selection and Characterization of Single Chain Antibody Fragments Specific for Hsp90 as a Potential Cancer Targeting Molecule

    Directory of Open Access Journals (Sweden)

    Edyta Petters

    2015-08-01

    Full Text Available Heat shock proteins play an essential role in facilitating malignant transformation and they have been recognized as important factors in human cancers. One of the key elements of the molecular chaperones machinery is Hsp90 and it has recently become a target for anticancer therapeutic approaches. The potential and importance of Hsp90-directed agents becomes apparent when one realizes that disruption of Hsp90 function may influence over 200 oncogenic client proteins. Here, we described the selection and characterization of Hsp90-specific antibody fragments from commercially available Tomlinson I and J phage display libraries. The affinities of Hsp90-binding scFv variants were measured using SPR method. Then, based on the best clone selected, we performed the affinity maturation procedure and obtained valuable Hsp90-specific clones. The selected binders were expressed and applied for immunostaining, ELISA and SPR analysis using model cancer cell lines. All performed experiments confirmed the ability of selected antibodies to interact with the Hsp90. Therefore, the presented Hsp90-specific scFv, might be a starting point for the development of a novel antibody-based strategy targeting cancer.

  19. Expression analysis and specific blockade of the receptor for human thymic stromal lymphopoietin (TSLP) by novel antibodies to the human TSLPRα receptor chain.

    Science.gov (United States)

    Borowski, Andreas; Vetter, Tina; Kuepper, Michael; Wohlmann, Andreas; Krause, Sebastian; Lorenzen, Thomas; Virchow, Johann Christian; Luttmann, Werner; Friedrich, Karlheinz

    2013-02-01

    Thymic stromal lymphopoietin (TSLP) is an interleukin-7 (IL-7)-like cytokine with a pivotal role in development and maintenance of atopic diseases such as allergic asthma and atopic dermatitis. Moreover, recent studies show an involvement of TSLP in the progression of various cancers. TSLP signaling is mediated by the TSLP receptor (TSLPR), a heterodimeric type I cytokine receptor. It consists of the IL-7 receptor alpha chain (IL-7Rα), which is shared with the IL-7 receptor, and the TSLPRα chain as a specific subunit. Blocking signal release by TSLP without affecting IL-7 function is a potentially interesting option for the treatment of atopic diseases or certain tumors. By employing the extracellular domain of human TSLPRα chain (hTSLPRα(ex)) as an antigen, we generated a set of monoclonal antibodies. Several binders to native and/or denatured receptor protein were identified and characterized by cytometry and Western blot analysis. A screen based on a STAT3-driven reporter gene assay in murine pro-B cells expressing a functional hTSLPR yielded two hybridoma clones with specific antagonistic properties towards hTSLP, but not IL-7. Kinetic studies measuring blockade of hTSLP-dependent STAT phosphorylation in a TSLP-responsive cell line revealed an inhibitory constant in the nanomolar range. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Neutralisation and binding of VHS virus by monovalent antibody fragments

    DEFF Research Database (Denmark)

    Cupit, P.M.; Lorenzen, Niels; Strachan, G.

    2001-01-01

    We have previously reported the cloning and characterisation of the heavy and light chain variable domain genes encoding three monoclonal antibodies (Mabs) that bind viral haemorrhagic septicaemia virus (VHSV). Two of these antibodies, 3F1H10 and 3F1A2 both neutralised the virus though 3F1A2...... appeared to recognise a broader range of virus isolates. The variable domains of these two antibodies differ by only four residues (Lorenzen et al., 2000a. Fish Shellfish Immunol. 10, 129-142). To further study the mechanism of neutralisation, Fab fragments as well as a series of recombinant bacterial...... single chain antibody (scAb) fragments were generated from the three anti-VHSV Mabs and their variable domain genes, respectively. Fabs and scAbs derived from the neutralising Mabs were both able to neutralise the VHSV type 1 isolate DK-F1. In addition, a series of scAb fragments were produced using...

  1. A single-chain fusion molecule consisting of peptide, major histocompatibility gene complex class I heavy chain and beta2-microglobulin can fold partially correctly, but binds peptide inefficiently

    DEFF Research Database (Denmark)

    Sylvester-Hvid, C; Buus, S

    1999-01-01

    of a recombinant murine MHC-I molecule, which could be produced in large amounts in bacteria. The recombinant MHC-I protein was expressed as a single molecule (PepSc) consisting of the antigenic peptide linked to the MHC-I heavy chain and further linked to human beta2-microglobulin (hbeta2m). The PepSc molecule...... electrophoresis (SDS-PAGE). Serological analysis revealed the presence of some, but not all, MHC-I-specific epitopes. Biochemically, PepSc could bind peptide, however, rather ineffectively. We suggest that a partially correctly refolded MHC-I has been obtained....

  2. Myosin heavy chain-like localizes at cell contact sites during Drosophila myoblast fusion and interacts in vitro with Rolling pebbles 7

    Energy Technology Data Exchange (ETDEWEB)

    Bonn, Bettina R.; Rudolf, Anja; Hornbruch-Freitag, Christina; Daum, Gabor; Kuckwa, Jessica; Kastl, Lena; Buttgereit, Detlev [Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg (Germany); Renkawitz-Pohl, Renate, E-mail: renkawit@biologie.uni-marburg.de [Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg (Germany)

    2013-02-15

    Besides representing the sarcomeric thick filaments, myosins are involved in many cellular transport and motility processes. Myosin heavy chains are grouped into 18 classes. Here we show that in Drosophila, the unconventional group XVIII myosin heavy chain-like (Mhcl) is transcribed in the mesoderm of embryos, most prominently in founder cells (FCs). An ectopically expressed GFP-tagged Mhcl localizes in the growing muscle at cell–cell contacts towards the attached fusion competent myoblast (FCM). We further show that Mhcl interacts in vitro with the essential fusion protein Rolling pebbles 7 (Rols7), which is part of a protein complex established at cell contact sites (Fusion-restricted Myogenic-Adhesive Structure or FuRMAS). Here, branched F-actin is likely needed to widen the fusion pore and to integrate the myoblast into the growing muscle. We show that the localization of Mhcl is dependent on the presence of Rols7, and we postulate that Mhcl acts at the FuRMAS as an actin motor protein. We further show that Mhcl deficient embryos develop a wild-type musculature. We thus propose that Mhcl functions redundantly to other myosin heavy chains in myoblasts. Lastly, we found that the protein is detectable adjacent to the sarcomeric Z-discs, suggesting an additional function in mature muscles. - Highlights: ► The class XVIII myosin encoding gene Mhcl is transcribed in the mesoderm. ► Mhcl localization at contact sites of fusing myoblasts depends on Rols7. ► Mhcl interacts in vitro with Rols7 which is essential for myogenesis. ► Functional redundancy with other myosins is likely as mutants show no muscle defects. ► Mhcl localizes adjacent to Z-discs of sarcomeres and might support muscle integrity.

  3. Myosin heavy chain-like localizes at cell contact sites during Drosophila myoblast fusion and interacts in vitro with Rolling pebbles 7

    International Nuclear Information System (INIS)

    Bonn, Bettina R.; Rudolf, Anja; Hornbruch-Freitag, Christina; Daum, Gabor; Kuckwa, Jessica; Kastl, Lena; Buttgereit, Detlev; Renkawitz-Pohl, Renate

    2013-01-01

    Besides representing the sarcomeric thick filaments, myosins are involved in many cellular transport and motility processes. Myosin heavy chains are grouped into 18 classes. Here we show that in Drosophila, the unconventional group XVIII myosin heavy chain-like (Mhcl) is transcribed in the mesoderm of embryos, most prominently in founder cells (FCs). An ectopically expressed GFP-tagged Mhcl localizes in the growing muscle at cell–cell contacts towards the attached fusion competent myoblast (FCM). We further show that Mhcl interacts in vitro with the essential fusion protein Rolling pebbles 7 (Rols7), which is part of a protein complex established at cell contact sites (Fusion-restricted Myogenic-Adhesive Structure or FuRMAS). Here, branched F-actin is likely needed to widen the fusion pore and to integrate the myoblast into the growing muscle. We show that the localization of Mhcl is dependent on the presence of Rols7, and we postulate that Mhcl acts at the FuRMAS as an actin motor protein. We further show that Mhcl deficient embryos develop a wild-type musculature. We thus propose that Mhcl functions redundantly to other myosin heavy chains in myoblasts. Lastly, we found that the protein is detectable adjacent to the sarcomeric Z-discs, suggesting an additional function in mature muscles. - Highlights: ► The class XVIII myosin encoding gene Mhcl is transcribed in the mesoderm. ► Mhcl localization at contact sites of fusing myoblasts depends on Rols7. ► Mhcl interacts in vitro with Rols7 which is essential for myogenesis. ► Functional redundancy with other myosins is likely as mutants show no muscle defects. ► Mhcl localizes adjacent to Z-discs of sarcomeres and might support muscle integrity

  4. Designing Optimal LNG Station Network for U.S. Heavy-Duty Freight Trucks using Temporally and Spatially Explicit Supply Chain Optimization

    Science.gov (United States)

    Lee, Allen

    The recent natural gas boom has opened much discussion about the potential of natural gas and specifically Liquefied Natural Gas (LNG) in the United States transportation sector. The switch from diesel to natural gas vehicles would reduce foreign dependence on oil, spur domestic economic growth, and potentially reduce greenhouse gas emissions. LNG provides the most potential for the medium to heavy-duty vehicle market partially due to unstable oil prices and stagnant natural gas prices. As long as the abundance of unconventional gas in the United States remains cheap, fuel switching to natural gas could provide significant cost savings for long haul freight industry. Amid a growing LNG station network and ever increasing demand for freight movement, LNG heavy-duty truck sales are less than anticipated and the industry as a whole is less economic than expected. In spite of much existing and mature natural gas infrastructure, the supply chain for LNG is different and requires explicit and careful planning. This thesis proposes research to explore the claim that the largest obstacle to widespread LNG market penetration is sub-optimal infrastructure planning. No other study we are aware of has explicitly explored the LNG transportation fuel supply chain for heavy-duty freight trucks. This thesis presents a novel methodology that links a network infrastructure optimization model (represents supply side) with a vehicle stock and economic payback model (represents demand side). The model characterizes both a temporal and spatial optimization model of future LNG transportation fuel supply chains in the United States. The principal research goal is to assess the economic feasibility of the current LNG transportation fuel industry and to determine an optimal pathway to achieve ubiquitous commercialization of LNG vehicles in the heavy-duty transport sector. The results indicate that LNG is not economic as a heavy-duty truck fuel until 2030 under current market conditions

  5. A natively paired antibody library yields drug leads with higher sensitivity and specificity than a randomly paired antibody library.

    Science.gov (United States)

    Adler, Adam S; Bedinger, Daniel; Adams, Matthew S; Asensio, Michael A; Edgar, Robert C; Leong, Renee; Leong, Jackson; Mizrahi, Rena A; Spindler, Matthew J; Bandi, Srinivasa Rao; Huang, Haichun; Tawde, Pallavi; Brams, Peter; Johnson, David S

    2018-04-01

    Deep sequencing and single-chain variable fragment (scFv) yeast display methods are becoming more popular for discovery of therapeutic antibody candidates in mouse B cell repertoires. In this study, we compare a deep sequencing and scFv display method that retains native heavy and light chain pairing with a related method that randomly pairs heavy and light chain. We performed the studies in a humanized mouse, using interleukin 21 receptor (IL-21R) as a test immunogen. We identified 44 high-affinity binder scFv with the native pairing method and 100 high-affinity binder scFv with the random pairing method. 30% of the natively paired scFv binders were also discovered with the randomly paired method, and 13% of the randomly paired binders were also discovered with the natively paired method. Additionally, 33% of the scFv binders discovered only in the randomly paired library were initially present in the natively paired pre-sort library. Thus, a significant proportion of "randomly paired" scFv were actually natively paired. We synthesized and produced 46 of the candidates as full-length antibodies and subjected them to a panel of binding assays to characterize their therapeutic potential. 87% of the antibodies were verified as binding IL-21R by at least one assay. We found that antibodies with native light chains were more likely to bind IL-21R than antibodies with non-native light chains, suggesting a higher false positive rate for antibodies from the randomly paired library. Additionally, the randomly paired method failed to identify nearly half of the true natively paired binders, suggesting a higher false negative rate. We conclude that natively paired libraries have critical advantages in sensitivity and specificity for antibody discovery programs.

  6. Myosin heavy chain isoform expression in adult and juvenile mini-muscle mice bred for high-voluntary wheel running.

    Science.gov (United States)

    Talmadge, Robert J; Acosta, Wendy; Garland, Theodore

    2014-11-01

    The myosin heavy chain (MyHC) isoform composition of locomotor and non-locomotor muscles of mini-muscle mice were assessed at the protein and mRNA levels in both adult and juvenile (21 day old) mice. Mini-muscle mice are one outcome of a replicated artificial selection experiment in which four lines of mice were bred for high voluntary wheel running (HR lines). Two of the lines responded with an increase in frequency of a single nucleotide polymorphism in an intron in the MyHC-2b gene (myh4) that when homozygous causes a dramatic reduction in triceps surae mass. We found that both locomotor and non-locomotor muscles of adult mini-muscle mice displayed robust reductions, but not elimination, of the MyHC-2b isoform at both the protein and mRNA levels, with commensurate increases in MyHC-2x and sometimes MyHC-2a, as compared with either a line of HR mice that does not display the mini-muscle phenotype or inbred C57Bl6 mice. Immunohistochemical analyses revealed that locomotor muscles of mini-muscle mice contain fibers that express the MyHC-2b isoform, which migrates normally in SDS-PAGE gels. However, these MyHC-2b positive fibers are generally smaller than the surrounding fibers and smaller than the MyHC-2b positive fibers of non-mini-muscle mice, resulting in characteristically fast muscles that lack a substantial MyHC-2b positive (superficial) region. In contrast, the masseter, a non-locomotor muscle of mini-muscle mice contained MyHC-2b positive fibers that stained more lightly for MyHC-2b, but appeared normal in size and distribution. In adults, many of the MyHC-2b positive fibers in the mini-muscle mice also display central nuclei. Only a small proportion of small MyHC-2b fibers in mini-muscle mice stained positive for the neural cell adhesion molecule, suggesting that anatomical innervation was not compromised. In addition, weanling (21 day old), but not 5 day old mice, displayed alterations in MyHC isoform content at both the protein and mRNA levels, including

  7. Varicella zoster virus myelitis in two elderly patients: diagnostic value of nested polymerase chain reaction assay and antibody index for cerebrospinal fluid specimens.

    Science.gov (United States)

    Takahashi, Teruyuki; Tamura, Masato; Miki, Kenji; Yamaguchi, Mai; Kanno, Akira; Nunomura, Satoshi; Ra, Chisei; Tamiya, Takashi; Kamei, Satoshi; Takasu, Toshiaki

    2013-01-01

    Myelitis is one of the rarest neurological complications of the varicella zoster virus (VZV) infection. Focal muscle weakness with or without sensory disturbance occurs in approximately 5% of the cases after acute VZV infection, with complete recovery in 50-70%. This report describes two rare cases of elderly patients with VZV myelitis secondary to dermatomal zoster rash. Patient 1 was a 79-year-old woman who developed paraplegia, numbness and decreased sensation in the left arm and below thoracic (Th)-10 after sacral zoster. Spinal cord MRI showed a high-signal-intensity lesion at the cervical spinal nerve 2 on a T2-weighted image. Patient 2 was a 73-year-old man who developed right flaccid leg weakness and urinary retention after right dorsal Th 5-8 zoster. Spinal cord MRI showed a high-signal-intensity lesion at Th 3-4 on a T2-weighted image. In both cases, although the conventional single polymerase chain reaction (PCR) assays all showed negative results, the original nested PCR assay detected VZV DNA in the cerebrospinal fluid (CSF) specimen collected on admission. In addition, the anti-VZV IgG antibody by enzyme immunoassay and antibody index were elevated in the CSF specimens during the clinical courses of both patients. On the basis of these findings, both patients were diagnosed with VZV myelitis and were treated with high-dose acyclovir and corticosteroid. This combined treatment was appropriate and effective for the improvement of their functional outcomes. The detection of VZV DNA in CSF by nested PCR assay and the evaluation of the antibody index to VZV had significant diagnostic value.

  8. Production of monoclonal antibodies and development of a quantitative immuno-polymerase chain reaction assay to detect and quantify recombinant Glutathione S-transferase.

    Science.gov (United States)

    Abud, J E; Luque, E H; Ramos, J G; Rodriguez, H A

    2017-07-01

    GST-tagged proteins are important tools for the production of recombinant proteins. Removal of GST tag from its fusion protein, frequently by harsh chemical treatments or proteolytic methods, is often required. Thus, the monitoring of the proteins in tag-free form requires a significant effort to determine the remnants of GST during purification process. In the present study, we developed both a conventional enzyme-linked immunosorbent assay (ELISA) and an immuno-polymerase chain reaction (IPCR) assay, both specific for detection of recombinant GST (rGST). rGST was expressed in Escherichia coli JM109, using a pGEX4T-3 vector, and several anti-rGST monoclonal antibodies were generated using hybridoma technology. Two of these were rationally selected as capture and detection antibodies, allowing the development of a sandwich ELISA with a limit of detection (LOD) of 0.01 μg/ml. To develop the rGST-IPCR assay, we selected "Universal-IPCR" format, comprising the biotin-avidin binding as the coupling system. In addition, the rGST-IPCR was developed in standard PCR tubes, and the surface adsorption of antibodies on PCR tubes, the optimal neutravidin concentrations, the generation of a reporter DNA and the concentration effect were studied and determined. Under optimized assay conditions, the rGST-IPCR assay provided a 100-fold increase in the LOD as well as an expanded working range, in comparison with rGST-ELISA. The proposed method exhibited great potentiality for application in several fields in which measurement of very low levels of GST is necessary, and might provide a model for other IPCR assays. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Development of an enhanced bovine viral diarrhea virus subunit vaccine based on E2 glycoprotein fused to a single chain antibody which targets to antigen-presenting cells

    Directory of Open Access Journals (Sweden)

    Andrea Pecora

    2015-03-01

    Full Text Available Bovine viral diarrhea virus (BVDV is an important cause of economic losses worldwide. E2 is an immunodominant protein and a promising candidate to develop subunit vaccines. To improve its immunogenicity, a truncated E2 (tE2 was fused to a single chain antibody named APCH, which targets to antigen-presenting cells. APCH-tE2 and tE2 proteins were expressed in the baculovirus system and their immunogenicity was firstly compared in guinea pigs. APCH-tE2 vaccine was the best one to evoke a humoral response, and for this reason, it was selected for a cattle vaccination experiment. All the bovines immunized with 1.5 µg of APCH-tE2 developed high levels of neutralizing antibodies against BVDV up to a year post-immunization, demonstrating its significant potential as a subunit vaccine. This novel vaccine is undergoing scale-up and was transferred to the private sector. Nowadays, it is being evaluated for registration as the first Argentinean subunit vaccine for cattle.

  10. Highly sensitive antibody-aptamer sensor for vascular endothelial growth factor based on hybridization chain reaction and pH meter/indicator.

    Science.gov (United States)

    Xu, Huifeng; Kou, Fangxia; Ye, Hongzhi; Wang, Zongwen; Huang, Suixin; Liu, Xianxiang; Zhu, Xi; Lin, Zhenyu; Chen, Guonan

    2017-12-01

    Vascular endothelial growth factor (VEGF) is a crucial signaling protein for the tumor growth and metastasis, which is also acted as the biomarkers for various diseases. In this research, we fabricate an aptamer-antibody sensor for point-of-care test of VEGF. Firstly, target VEGF is captured by antibody immobilized on the microplate, and then binds with aptamer to form the sandwich structure. Next, with the assist of glucose oxidase (GOx)-functionalized ssDNAs, hybridization chain reaction occurs using the aptamer as the primer. Thus, GOx are greatly gathered on the microplate, which catalyzes the oxidization of glucose, leading to the pH change. As a result, the detect limit at a signal-to-noise was estimated to be 0.5pg/mL of target by pH meter, and 1.6pg/mL of VEGF was able to be distinguished by naked eyes. Meanwhile, this method has been used assay VEGF in the serum with the satisfactory results. Copyright © 2017. Published by Elsevier B.V.

  11. Development of an enhanced bovine viral diarrhea virus subunit vaccine based on E2 glycoprotein fused to a single chain antibody which targets to antigen-presenting cells.

    Science.gov (United States)

    Pecora, Andrea; Malacari, Darío A; Pérez Aguirreburualde, María S; Bellido, Demian; Escribano, José M; Dus Santos, María J; Wigdorovitz, Andrés

    2015-01-01

    Bovine viral diarrhea virus (BVDV) is an important cause of economic losses worldwide. E2 is an immunodominant protein and a promising candidate to develop subunit vaccines. To improve its immunogenicity, a truncated E2 (tE2) was fused to a single chain antibody named APCH, which targets to antigen-presenting cells. APCH-tE2 and tE2 proteins were expressed in the baculovirus system and their immunogenicity was firstly compared in guinea pigs. APCH-tE2 vaccine was the best one to evoke a humoral response, and for this reason, it was selected for a cattle vaccination experiment. All the bovines immunized with 1.5 μg of APCH-tE2 developed high levels of neutralizing antibodies against BVDV up to a year post-immunization, demonstrating its significant potential as a subunit vaccine. This novel vaccine is undergoing scale-up and was transferred to the private sector. Nowadays, it is being evaluated for registration as the first Argentinean subunit vaccine for cattle. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Study of heavy metals in the grass-milk product chain by means of neutron activation and atomic absorption

    Energy Technology Data Exchange (ETDEWEB)

    Bruant, C; Bruant, J P; Neuburger, M; Vassal, L; Disant, C; Bittel, R; Fourcy, A

    1974-12-31

    with the heavy metals Hg, Cu, Zn, Pb, and Cd is studied. The first three metals were determined by neutron activation and tae last two by atomic absorption spectrophotometry. The chemical rature of these metals and their biological effect leads to different results from those obtained for tae principal fission products. As a rule the heavy metal concentrations at harvest are much lower than taat of the foods ingested by lactating cows. The cow plays the role of filter. If the concentration of these elements is considered in mu g/g of fresh material there is a reconcentration of these heavy metals in cream and cheese, probably cornected with their physico-chemical affinity for proteins. (JSR)

  13. 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.

  14. In vivo therapy of a murine B cell tumor (BCL1) using antibody-ricin A chain immunotoxins

    International Nuclear Information System (INIS)

    Krolick, K.A.; Uhr, J.W.; Slavin, S.; Vitetta, E.S.

    1982-01-01

    Prolonged remissions were induced in mice bearing advanced BCL1 tumors by the combined approach of nonspecific cytoreductive therapy and administration of a tumor-reactive immunotoxin. Thus, the vast majority of the tumor cells (approximately 95%) were first killed by nonspecific cytoreductive therapy using total lymphoid irradiation (TLI) and splenectomy. The residual tumor cells were then eliminated by intravenous administration of an anti-delta immunotoxin. In three of four experiments, all animals treated in the above fashion appeared tumor free 12-16 wk later. In one experiment, blood cells from the mice in remission were transferred to normal BALB/c recipients, and the latter animals have not developed detectable tumor for the 6 mo of observation. Because 1-10 adoptively transferred BCL1 cells will cause tumor in normal BALB/c mice by 12 wk, the inability to transfer tumor to recipients might indicate that the donor animals were tumor free. In the remainder of the animals treated with the tumor-reactive immunotoxin there was a substantial remission in all animals, but the disease eventually reappeared. In contrast, all mice treated with the control immunotoxin or antibody alone relapsed significantly earlier

  15. Heavy metal concentrations in a soil-plant-snail food chain along a terrestrial soil pollution gradient.

    NARCIS (Netherlands)

    Notten, M.J.M.; Oosthoek, A.; Rozema, J.; Aerts, R.

    2005-01-01

    We investigated concentrations of Zn, Cu, Cd and Pb in the compartments of a soil-plant (Urtica dioica)-snail (Cepaea nemoralis) food chain in four polluted locations in the Biesbosch floodplains, the Netherlands, and two reference locations. Total soil metal concentrations in the polluted locations

  16. A novel antibody engineering strategy for making monovalent bispecific heterodimeric IgG antibodies by electrostatic steering mechanism.

    Science.gov (United States)

    Liu, Zhi; Leng, Esther C; Gunasekaran, Kannan; Pentony, Martin; Shen, Min; Howard, Monique; Stoops, Janelle; Manchulenko, Kathy; Razinkov, Vladimir; Liu, Hua; Fanslow, William; Hu, Zhonghua; Sun, Nancy; Hasegawa, Haruki; Clark, Rutilio; Foltz, Ian N; Yan, Wei

    2015-03-20

    Producing pure and well behaved bispecific antibodies (bsAbs) on a large scale for preclinical and clinical testing is a challenging task. Here, we describe a new strategy for making monovalent bispecific heterodimeric IgG antibodies in mammalian cells. We applied an electrostatic steering mechanism to engineer antibody light chain-heavy chain (LC-HC) interface residues in such a way that each LC strongly favors its cognate HC when two different HCs and two different LCs are co-expressed in the same cell to assemble a functional bispecific antibody. We produced heterodimeric IgGs from transiently and stably transfected mammalian cells. The engineered heterodimeric IgG molecules maintain the overall IgG structure with correct LC-HC pairings, bind to two different antigens with comparable affinity when compared with their parental antibodies, and retain the functionality of parental antibodies in biological assays. In addition, the bispecific heterodimeric IgG derived from anti-HER2 and anti-EGF receptor (EGFR) antibody was shown to induce a higher level of receptor internalization than the combination of two parental antibodies. Mouse xenograft BxPC-3, Panc-1, and Calu-3 human tumor models showed that the heterodimeric IgGs strongly inhibited tumor growth. The described approach can be used to generate tools from two pre-existent antibodies and explore the potential of bispecific antibodies. The asymmetrically engineered Fc variants for antibody-dependent cellular cytotoxicity enhancement could be embedded in monovalent bispecific heterodimeric IgG to make best-in-class therapeutic antibodies. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Purification and refolding of anti-T-antigen single chain antibodies (scFvs) expressed in Escherichia coli as inclusion bodies.

    Science.gov (United States)

    Yuasa, Noriyuki; Koyama, Tsubasa; Fujita-Yamaguchi, Yoko

    2014-02-01

    T-antigen (Galβ1-3GalNAcα-1-Ser/Thr) is an oncofetal antigen that is commonly expressed as a carbohydrate determinant in many adenocarcinomas. Since it is associated with tumor progression and metastasis, production of recombinant antibodies specific for T-antigen could lead to the development of cancer diagnostics and therapeutics. Previously, we isolated and characterized 11 anti-T-antigen phage clones from a phage library displaying human single-chain antibodies (scFvs) and purified one scFv protein, 1G11. More recently, we purified and characterized 1E8 scFv protein using a Drosophila S2 expression system. In the current study, four anti-T-antigen scFv genes belonging to Groups 1-4 were purified from inclusion bodies expressed in Escherichia coli cells. Inclusion bodies isolated from E. coli cells were denatured in 3.5 M Gdn-HCl. Solubilized His-tagged scFv proteins were purified using Ni(2+)-Sepharose column chromatography in the presence of 3.5 M Gdn-HCl. Purified scFv proteins were refolded according to a previously published method of step-wise dialysis. Two anti-T-antigen scFv proteins, 1E6 and 1E8 that belong to Groups 1 and 2, respectively, were produced in sufficient amounts, thus allowing further characterization of their binding activity with T-antigen. Specificity and affinity constants determined using enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR), respectively, provided evidence that both 1E8 and 1E6 scFv proteins are T-antigen specific and suggested that 1E8 scFv protein has a higher affinity for T-antigen than 1E6 scFv protein.

  18. In-Vivo Neutralization of Botulinum Neurotoxin Serotype E Using Rabbit Polyclonal Antibody Developed against BoNT/E Light Chain.

    Science.gov (United States)

    Rani, Sarita; Ponmariappan, S; Sharma, Arti; Kamboj, D V; Jain, A K

    2017-01-01

    Clostridium botulinum is an obligate anaerobic, Gram positive bacterium that secretes extremely toxic substances known as botulinum neurotoxins (BoNTs) that cause serious paralytic illness called botulism. Based upon the serological properties, these neurotoxin have been classified into seven serotypes designated from A to G. Due to extreme toxicity of BoNTs, these neurotoxins have been designated as category A biowarfare agents. There is no commercial neutralizing antibody available for the treatment of botulism. Hence there is an urgent need to develop therapeutic intervention for prevention and cure of botulism within short period. BoNT antiserum injection is still the effective treatment. In the present study, the recombinant light chain of BoNT/E was successfully purified in soluble form. The purified rBoNT/E LC was used for the generation of polyclonal antibody in rabbit. In order to find out the neutralizing capacity of generated antisera, rabbit antiserum was incubated with 20 LD50 of botulinum neurotoxin type E for 1 hour at 37°C and then injected intraperitoneally (IP) into mice. Further in another set of experiments antiserum was administered in different ways that included administration of - antiserum and BoNT/E toxin simultaneously without preincubation, one after another at the same and different time points for its therapeutic ability. To find out cross neutralization capacity, rBoNT/E LC antiserum was pre-incubated with 5 LD50 of BoNT/A, BoNT/B, BoNT/F and then injected (IP) into mice. In all the cases mice were observed continuously for 96 hours. The results clearly indicate that developed polyclonal rabbit antiserum showed serotype specific neutralization of BoNT/E toxin only but not of BoNT/A, BoNT/B and BoNT/F. The developed antibodies will be used for preventive and therapeutic intervention of type 'E' botulism. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. A novel affinity purification method to isolate peptide specific antibodies

    DEFF Research Database (Denmark)

    Karlsen, Alan E; Lernmark, A; Kofod, Hans

    1990-01-01

    Site-specific, high affinity polyclonal antisera are effectively and successfully produced by immunizing rabbits with synthetic peptides. The use of these antisera in subsequent immune analysis is often limited because of non-specific binding. We describe a new and simple method to effectively...... affinity-purify anti-peptide antibodies. To test our system, rabbits were immunized with model peptides representing sequences of the putative rabbit growth hormone receptor and several HLA-DQ beta-chain molecules. Polystyrene plastic beads were coated with peptides. Immune serum was incubated...... with the beads and after a wash step the bound antibodies were eluted in 1 M acetic acid. The eluted material was composed predominantly of intact immunoglobulin as evidenced by the presence of heavy and light chain bands in SDS-PAGE. The eluted antibodies were peptide specific in ELISA and bound only to intact...

  20. Comparison of myosin heavy chain mRNAs, protein isoforms and fiber type proportions in the rat slow and fast muscles

    Czech Academy of Sciences Publication Activity Database

    Žurmanová, J.; Soukup, Tomáš

    2013-01-01

    Roč. 62, č. 4 (2013), s. 445-453 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/08/0256; GA ČR(CZ) GA305/09/1228; GA MŠk(CZ) 7AMB12SK158; GA MŠk(CZ) LH12058 Grant - others:EC(XE) LSH-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : rat * soleus * extensor digitorum longus * myosin heavy chain isoforms * muscle gene expression * quantitative Real Time RT-PCR * SDS - PAGE * fiber type analysis Subject RIV: EA - Cell Biology Impact factor: 1.487, year: 2013

  1. Immunoglobulin heavy and light chains and T-cell receptor beta and gamma chains PCR assessment on cytological samples. A study comparing FTA cards and cryopreserved lymph node fine-needle cytology.

    Science.gov (United States)

    Peluso, A L; Cozzolino, I; Bottiglieri, A; Lucchese, L; Di Crescenzo, R M; Langella, M; Selleri, C; Zeppa, P

    2017-06-01

    To evaluate and compare the DNA yield and quality extracted from lymph node fine needle cytology (FNC) samples stored on FTA cards to those cryopreserved, and to assess the immunoglobulin heavy and light chains (IGHK) and T-Cell receptor beta and gamma chains (TCRBG) PCR tests. DNA extractions were performed on FNC of 80 non-Hodgkin lymphomas (NHL), four myelomas and 56 benign reactive hyperplasias (BRH) cryopreserved and stored on FTA cards. The JAK2 gene was amplified to assess the DNA integrity and the IGHK/TCRBG clonality status was tested. IGHK monoclonality was found in 99% of B-cell NHL and 100% of myeloma. TCRBG monoclonality was found in 100% of T-cell NHL. TCRBG polyclonality was detected in 97% of B-cell NHL, 100% of myeloma and 96% of BRH. IGHK/TCRBG PCR data were confirmed by histological and/or follow-up controls. No differences were found in the DNA quality between cryopreservation and FTA cards storage methods. IGHK/TCRBG PCR of the lymphoproliferative process on FTA cards is comparable to those cryopreserved. FTA cards can be used to store lymph node FNC for further molecular investigations. © 2016 John Wiley & Sons Ltd.

  2. Preparation and characterization of chimeric CD19 monoclonal antibody

    International Nuclear Information System (INIS)

    Zola, H.; Macardle, P.J.; Bradford, T.; Weedon, H.; Yasui, H.; Kurosawa, Y.

    1991-01-01

    CD19 antibodies have been suggested as candidates for immunological attack on leukemic and lymphoma cells of the B lineage because the antigen is restricted to the B lineage. With the potential use of FMC63 in immunotherapy in mind a mouse-human chimera was produced in which the genes coding for the VDJ region of the heavy chain and the VJ region of the light chain derive from the FMC63 mouse hybridoma, while the C region genes code for human IgG1. The genes have been transfected back into a mouse myeloma line, which secretes low levels of immunoglobulin. (Ig). This Ig was purified and biotinylated in order to determine the specificity of the antibody. The chimeric antibody has a reaction profile concordant with the original FMC63 antibody, but has the properties of a human IgG1, including the ability to fix human complement. However, the antibody is not cytotoxic in vitro in the presence of complement or cells capable of mediating antibody-dependent cellular cytotoxicity. Possible reasons for this and ways of using the antibody are discussed. 47 refs., 7 figs

  3. Fluorescent antibody test, quantitative polymerase chain reaction pattern and clinical aspects of rabies virus strains isolated from main reservoirs in Brazil

    Directory of Open Access Journals (Sweden)

    Camila Appolinário

    2015-09-01

    Full Text Available Rabies virus (RABV isolated from different mammals seems to have unique characteristics that influence the outcome of infection. RABV circulates in nature and is maintained by reservoirs that are responsible for the persistence of the disease for almost 4000 years. Considering the different pattern of pathogenicity of RABV strains in naturally and experimentally infected animals, the aim of this study was to analyze the characteristics of RABV variants isolated from the main Brazilian reservoirs, being related to a dog (variant 2, Desmodus rotundus (variant 3, crab eating fox, marmoset, and Myotis spp. Viral replication in brain tissue of experimentally infected mouse was evaluated by two laboratory techniques and the results were compared to clinical evolution from five RABV variants. The presence of the RABV was investigated in brain samples by fluorescent antibody test (FAT and real time polymerase chain reaction (qRT-PCR for quantification of rabies virus nucleoprotein gene (N gene. Virus replication is not correlated with clinical signs and evolution. The pattern of FAT is associated with RABV replication levels. Virus isolates from crab eating fox and marmoset had a longer evolution period and higher survival rate suggesting that the evolution period may contribute to the outcome. RABV virus variants had independent characteristics that determine the clinical evolution and survival of the infected mice.

  4. ESCRT-mediated uptake and degradation of brain-targeted α-synuclein single chain antibody attenuates neuronal degeneration in vivo.

    Science.gov (United States)

    Spencer, Brian; Emadi, Sharareh; Desplats, Paula; Eleuteri, Simona; Michael, Sarah; Kosberg, Kori; Shen, Jay; Rockenstein, Edward; Patrick, Christina; Adame, Anthony; Gonzalez, Tania; Sierks, Michael; Masliah, Eliezer

    2014-10-01

    Parkinson's disease and dementia with Lewy bodies are neurodegenerative disorders characterized by accumulation of α-synuclein (α-syn). Recently, single-chain fragment variables (scFVs) have been developed against individual conformational species of α-syn. Unlike more traditional monoclonal antibodies, these scFVs will not activate or be endocytosed by Fc receptors. For this study, we investigated an scFV directed against oligomeric α-syn fused to the LDL receptor-binding domain from apolipoprotein B (apoB). The modified scFV showed enhanced brain penetration and was imported into neuronal cells through the endosomal sorting complex required for transport (ESCRT) pathway, leading to lysosomal degradation of α-syn aggregates. Further analysis showed that the scFV was effective at ameliorating neurodegenerative pathology and behavioral deficits observed in the mouse model of dementia with Lewy bodies/Parkinson's disease. Thus, the apoB modification had the effect of both increasing accumulation of the scFV in the brain and directing scFV/α-syn complexes for degradation through the ESCRT pathway, leading to improved therapeutic potential of immunotherapy.

  5. The biodistribution and pretargeting radioimmunoimaging of the fusion protein of anti-CEA single-chain antibody and core-streptavidin in human rectocolonic tumor bearing nude mice

    International Nuclear Information System (INIS)

    Yang Weidong; Li Biao; Zhu Chengmo; Jiang Xufeng; Feng Guowei; Wu Xiangpu

    2002-01-01

    Objective: To investigate the biodistribution and two-step pretargeting radioimmunoimaging of the fusion protein of anti-carcinoembryonic antigen (CEA) single-chain antibody (ScFv) and core-streptavidin in human rectocolonic tumor bearing nude mice. Methods: Before the injection of 153 Sm-biotin, the fusion protein of ScFv-core-streptavidin was pretargeted for 24 h (200 μg every nude mouse), 24 h later 153 Sm-biotin was injected. The uptake of radioactivity in tumor and normal tissues in 20 nude mice was measured at 1, 4, 8 and 24 h and the other 3 nude mice was scanned at 8 and 24 h after peritoneal injection of 153 Sm-biotin. Results: The tumor to blood ratio (tumor/blood) reached 0.49 , 1.21, 1.56 and 3.09 at 1, 4, 8 and 24 h respectively. Radioactivity concentration peaked at 8 h in tumor site and demonstrated a 'hot' area, with significant decreasing its background at 24 h. Conclusion: The fusion protein can elevate the tumor/blood ratio, shorten pretargeting and imaging process and also improve image quality

  6. Atrazine analysis using an amperometric immunosensor based on single-chain antibody fragments and regeneration-free multi-calibrant measurement

    International Nuclear Information System (INIS)

    Grennan, Kathleen; Strachan, Gillian; Porter, Andrew J.; Killard, Anthony J.; Smyth, Malcolm R.

    2003-01-01

    This work describes the development of an electrochemical immunosensor for the analysis of atrazine using recombinant single-chain antibody (scAb) fragments. The sensors are based on carbon paste screen-printed electrodes incorporating the conducting polymer polyaniline (PANI)/poly(vinylsulphonic acid) (PVSA), which enables direct mediatorless coupling to take place between the redox centres of antigen-labelled horseradish peroxidase (HRP) and the electrode surface. Competitive immunoassays can be performed in real-time using this separation-free system. Analytical measurements based on the pseudo-linear relationship between the slope of a real-time amperometric signal and the concentration of analyte, yield a novel immunosensor set-up capable of regenerationless amperometric analysis. Multiple, sequential measurements of standards and samples can be performed on a single scAb-modified surface in a matter of minutes. No separation of bound and unbound species was necessary prior to detection. The system is capable of measuring atrazine to a detection limit of 0.1 ppb (0.1 μg l -1 ). This system offers the potential for rapid, cost-effective immunosensing for the analysis of samples of environmental, medical and pharmaceutical significance

  7. Comparison of the membrane-filtration fluorescent antibody test, the enzyme-linked immunosorbent assay, and the polymerase chain reaction to detect Renibacterium salmoninarum in salmon ovarian fluid

    Science.gov (United States)

    Pascho, Ronald J.; Chase, Dorothy M.; McKibben, Constance L.

    1998-01-01

    Ovarian fluid samples from naturally infected chinook salmon (Oncorhynchus tshawytscha) were examined for the presence of Renibacterium salmoninarum by the membrane-filtration fluorescent antibody test (MF-FAT), an antigen capture enzyme-linked immunosorbent assay (ELISA), and a nested polymerase chain reaction (PCR). On the basis of the MF-FAT, 64% (66/103) samples contained detectable levels of R. salmoninarum cells. Among the positive fish, the R. salmoninarum concentrations ranged from 25 cells/ml to 4.3 × 109cells/ml. A soluble antigenic fraction of R. salmoninarum was detected in 39% of the fish (40/103) by the ELISA. The ELISA is considered one of the most sensitive detection methods for bacterial kidney disease in tissues, yet it did not detect R. salmoninarum antigen consistently at bacterial cell concentrations below about 1.3 × 104cells/ml according to the MF-FAT counts. When total DNA was extracted and tested in a nested PCR designed to amplify a 320-base-pair region of the gene encoding a soluble 57-kD protein of R. salmoninarum, 100% of the 100 samples tested were positive. The results provided strong evidence that R. salmoninarum may be present in ovarian fluids thought to be free of the bacterium on the basis of standard diagnostic methods.

  8. Comparison of immune responses against foot-and-mouth disease virus induced by fusion proteins using the swine IgG heavy chain constant region or β-galactosidase as a carrier of immunogenic epitopes

    International Nuclear Information System (INIS)

    Li Guangjin; Chen Weizao; Yan Weiyao; Zhao Kai; Liu Mingqiu; Zhang Jun; Fei Liang; Xu Quanxing; Sheng Zutian; Lu Yonggan; Zheng Zhaoxin

    2004-01-01

    Previously, we demonstrated that a fusion protein (Gal-FMDV) consisting of β-galactosidase and an immunogenic peptide, amino acids (141-160)-(21-40)-(141-160), of foot-and-mouth disease virus (FMDV) VP1 protein induced protective immune responses in guinea pigs and swine. We now designed a new potential recombinant protein vaccine against FMDV in swine. The immunogenic peptide, amino acids (141-160)-(21-40)-(141-160) from the VP1 protein of serotype O FMDV, was fused to the carboxy terminus of a swine immunoglobulin G single heavy chain constant region and expressed in Escherichia coli. The expressed fusion protein (IgG-FMDV) was purified and emulsified with oil adjuvant. Vaccination twice at an interval of 3 weeks with the emulsified IgG-FMDV fusion protein induced an FMDV-specific spleen proliferative T-cell response in guinea pigs and elicited high levels of neutralizing antibody in guinea pigs and swine. All of the immunized animals were efficiently protected against FMDV challenge. There was no significant difference between IgG-FMDV and Gal-FMDV in eliciting immunity after vaccination twice in swine. However, when evaluating the efficacy of a single inoculation of the fusion proteins, we found that IgG-FMDV could elicit a protective immune response in swine, while Gal-FMDV only elicited a weak neutralizing activity and could not protect the swine against FMDV challenge. Our results suggest that the IgG-FMDV fusion protein is a promising vaccine candidate for FMD in swine

  9. Antibody structural modeling with prediction of immunoglobulin structure (PIGS)

    DEFF Research Database (Denmark)

    Marcatili, Paolo; Olimpieri, Pier Paolo; Chailyan, Anna

    2014-01-01

    Antibodies (or immunoglobulins) are crucial for defending organisms from pathogens, but they are also key players in many medical, diagnostic and biotechnological applications. The ability to predict their structure and the specific residues involved in antigen recognition has several useful...... applications in all of these areas. Over the years, we have developed or collaborated in developing a strategy that enables researchers to predict the 3D structure of antibodies with a very satisfactory accuracy. The strategy is completely automated and extremely fast, requiring only a few minutes (∼10 min...... on average) to build a structural model of an antibody. It is based on the concept of canonical structures of antibody loops and on our understanding of the way light and heavy chains pack together....

  10. Antibody structural modeling with prediction of immunoglobulin structure (PIGS)

    KAUST Repository

    Marcatili, Paolo

    2014-11-06

    © 2014 Nature America, Inc. All rights reserved. Antibodies (or immunoglobulins) are crucial for defending organisms from pathogens, but they are also key players in many medical, diagnostic and biotechnological applications. The ability to predict their structure and the specific residues involved in antigen recognition has several useful applications in all of these areas. Over the years, we have developed or collaborated in developing a strategy that enables researchers to predict the 3D structure of antibodies with a very satisfactory accuracy. The strategy is completely automated and extremely fast, requiring only a few minutes (~10 min on average) to build a structural model of an antibody. It is based on the concept of canonical structures of antibody loops and on our understanding of the way light and heavy chains pack together.

  11. Immunoglobulin heavy-chain fluorescence in situ hybridization-chromogenic in situ hybridization DNA probe split signal in the clonality assessment of lymphoproliferative processes on cytological samples.

    Science.gov (United States)

    Zeppa, Pio; Sosa Fernandez, Laura Virginia; Cozzolino, Immacolata; Ronga, Valentina; Genesio, Rita; Salatiello, Maria; Picardi, Marco; Malapelle, Umberto; Troncone, Giancarlo; Vigliar, Elena

    2012-12-25

    The human immunoglobulin heavy-chain (IGH) locus at chromosome 14q32 is frequently involved in different translocations of non-Hodgkin lymphoma (NHL), and the detection of any breakage involving the IGH locus should identify a B-cell NHL. The split-signal IGH fluorescence in situ hybridization-chromogenic in situ hybridization (FISH-CISH) DNA probe is a mixture of 2 fluorochrome-labeled DNAs: a green one that binds the telomeric segment and a red one that binds the centromeric segment, both on the IGH breakpoint. In the current study, the authors tested the capability of the IGH FISH-CISH DNA probe to detect IGH translocations and diagnose B-cell lymphoproliferative processes on cytological samples. Fifty cytological specimens from cases of lymphoproliferative processes were tested using the split-signal IGH FISH-CISH DNA probe and the results were compared with light-chain assessment by flow cytometry (FC), IGH status was tested by polymerase chain reaction (PCR), and clinicohistological data. The signal score produced comparable results on FISH and CISH analysis and detected 29 positive, 15 negative, and 6 inadequate cases; there were 29 true-positive cases (66%), 9 true-negative cases (20%), 6 false-negative cases (14%), and no false-positive cases (0%). Comparing the sensitivity of the IGH FISH-CISH DNA split probe with FC and PCR, the highest sensitivity was obtained by FC, followed by FISH-CISH and PCR. The split-signal IGH FISH-CISH DNA probe is effective in detecting any translocation involving the IGH locus. This probe can be used on different samples from different B-cell lymphoproliferative processes, although it is not useful for classifying specific entities. Cancer (Cancer Cytopathol) 2012;. © 2012 American Cancer Society. Copyright © 2012 American Cancer Society.

  12. Primary structure of bovine calpactin I heavy chain (p36), a major cellular substrate for retroviral protein-tyrosine kinases: homology with the human phospholipase A2 inhibitor lipocortin

    DEFF Research Database (Denmark)

    Kristensen, Torsten; Sarin, C J; Hunter, T

    1986-01-01

    An amplified Okayama-Berg plasmid cDNA library was constructed from total poly(A)+ RNA isolated from the Madin-Darby bovine kidney cell line MDBK. This library was screened with a partial murine calpactin I heavy chain (p36) cDNA clone, the identification of which was based on bovine p36 tryptic ...

  13. A Cross-Reactive Human Single-Chain Antibody for Detection of Major Fish Allergens, Parvalbumins, and Identification of a Major IgE-Binding Epitope.

    Directory of Open Access Journals (Sweden)

    Merima Bublin

    Full Text Available Fish allergy is associated with moderate to severe IgE-mediated reactions to the calcium binding parvalbumins present in fish muscle. Allergy to multiple fish species is caused by parvalbumin-specific cross-reactive IgE recognizing conserved epitopes. In this study, we aimed to produce cross-reactive single chain variable fragment (scFv antibodies for the detection of parvalbumins in fish extracts and the identification of IgE epitopes. Parvalbumin-specific phage clones were isolated from the human ETH-2 phage display library by three rounds of biopanning either against cod parvalbumin or by sequential biopanning against cod (Gad m 1, carp (Cyp c 1 and rainbow trout (Onc m 1 parvalbumins. While biopanning against Gad m 1 resulted in the selection of clones specific exclusively for Gad m 1, the second approach resulted in the selection of clones cross-reacting with all three parvalbumins. Two clones, scFv-gco9 recognizing all three parvalbumins, and scFv-goo8 recognizing only Gad m 1 were expressed in the E. coli non-suppressor strain HB2151 and purified from the periplasm. scFv-gco9 showed highly selective binding to parvalbumins in processed fish products such as breaded cod sticks, fried carp and smoked trout in Western blots. In addition, the scFv-gco9-AP produced as alkaline phosphatase fusion protein, allowed a single-step detection of the parvalbumins. In competitive ELISA, scFv-gco9 was able to inhibit binding of IgE from fish allergic patients' sera to all three β-parvalbumins by up to 80%, whereas inhibition by scFv-goo8 was up to 20%. 1H/15N HSQC NMR analysis of the rGad m 1:scFv-gco9 complex showed participation of amino acid residues conserved among these three parvalbumins explaining their cross-reactivity on a molecular level. In this study, we have demonstrated an approach for the selection of cross-reactive parvalbumin-specific antibodies that can be used for allergen detection and for mapping of conserved epitopes.

  14. A Cross-Reactive Human Single-Chain Antibody for Detection of Major Fish Allergens, Parvalbumins, and Identification of a Major IgE-Binding Epitope.

    Science.gov (United States)

    Bublin, Merima; Kostadinova, Maria; Fuchs, Julian E; Ackerbauer, Daniela; Moraes, Adolfo H; Almeida, Fabio C L; Lengger, Nina; Hafner, Christine; Ebner, Christof; Radauer, Christian; Liedl, Klaus R; Valente, Ana Paula; Breiteneder, Heimo

    2015-01-01

    Fish allergy is associated with moderate to severe IgE-mediated reactions to the calcium binding parvalbumins present in fish muscle. Allergy to multiple fish species is caused by parvalbumin-specific cross-reactive IgE recognizing conserved epitopes. In this study, we aimed to produce cross-reactive single chain variable fragment (scFv) antibodies for the detection of parvalbumins in fish extracts and the identification of IgE epitopes. Parvalbumin-specific phage clones were isolated from the human ETH-2 phage display library by three rounds of biopanning either against cod parvalbumin or by sequential biopanning against cod (Gad m 1), carp (Cyp c 1) and rainbow trout (Onc m 1) parvalbumins. While biopanning against Gad m 1 resulted in the selection of clones specific exclusively for Gad m 1, the second approach resulted in the selection of clones cross-reacting with all three parvalbumins. Two clones, scFv-gco9 recognizing all three parvalbumins, and scFv-goo8 recognizing only Gad m 1 were expressed in the E. coli non-suppressor strain HB2151 and purified from the periplasm. scFv-gco9 showed highly selective binding to parvalbumins in processed fish products such as breaded cod sticks, fried carp and smoked trout in Western blots. In addition, the scFv-gco9-AP produced as alkaline phosphatase fusion protein, allowed a single-step detection of the parvalbumins. In competitive ELISA, scFv-gco9 was able to inhibit binding of IgE from fish allergic patients' sera to all three β-parvalbumins by up to 80%, whereas inhibition by scFv-goo8 was up to 20%. 1H/15N HSQC NMR analysis of the rGad m 1:scFv-gco9 complex showed participation of amino acid residues conserved among these three parvalbumins explaining their cross-reactivity on a molecular level. In this study, we have demonstrated an approach for the selection of cross-reactive parvalbumin-specific antibodies that can be used for allergen detection and for mapping of conserved epitopes.

  15. Generation of a rabbit single-chain fragment variable (scFv) antibody for specific detection of Bradyrhizobium sp. DOA9 in both free-living and bacteroid forms.

    Science.gov (United States)

    Vu, Nguyen Xuan; Pruksametanan, Natcha; Srila, Witsanu; Yuttavanichakul, Watcharin; Teamtisong, Kamonluck; Teaumroong, Neung; Boonkerd, Nantakorn; Tittabutr, Panlada; Yamabhai, Montarop

    2017-01-01

    A simple and reliable method for the detection of specific nitrogen-fixing bacteria in both free-living and bacteroid forms is essential for the development and application of biofertilizer. Traditionally, a polyclonal antibody generated from an immunized rabbit was used for detection. However, the disadvantages of using a polyclonal antibody include limited supply and cross-reactivity to related bacterial strains. This is the first report on the application of phage display technology for the generation of a rabbit recombinant monoclonal antibody for specific detection and monitoring of nitrogen-fixing bacteria in both free-living form and in plant nodules. Bradyrhizobium sp. DOA9, a broad host range soil bacteria, originally isolated from the root nodules of Aeschynomene americana in Thailand was used as a model in this study. A recombinant single-chain fragment variable (scFv) antibody library was constructed from the spleen of a rabbit immunized with DOA9. After three rounds of biopanning, one specific phage-displayed scFv antibody, designated bDOA9rb8, was identified. Specific binding of this antibody was confirmed by phage enzyme-linked immunosorbent assay (phage ELISA). The phage antibody could bind specifically to DOA9 in both free-living cells (pure culture) and bacteroids inside plant nodules. In addition to phage ELISA, specific and robust immunofluorescence staining of both free-living and bacteroid forms could also be observed by confocal-immunofluorescence imaging, without cross-reactivity with other tested bradyrhizobial strains. Moreover, specific binding of free scFv to DOA9 was also demonstrated by ELISA. This recombinant antibody can also be used for the study of the molecular mechanism of plant-microbe interactions in the future.

  16. Development of a monoclonal antibody to urinary degradation products from the C-terminal telopeptide alpha 1 chain of type I collagen. Application in an enzyme Immunoassay and comparison to CrossLaps(TM) ELISA

    DEFF Research Database (Denmark)

    C, Fledelius; I, Kolding; P, Quist

    1997-01-01

    A monoclonal antibody MAbA7 was raised against a synthetic peptide having a sequence (EKAHDGGR) specific for a part of the C-telopeptide alpha 1 chain of type I collagen. MAbA7 was labelled with horseradish peroxide and used in a competitive one-step enzyme-linked immunosorbent assay (ELISA...... concentrations decreased 88% (pantibody and the new assay may be useful for further investigations of the physiological...

  17. Heavy metal concentrations in a soil-plant-snail food chain along a terrestrial soil pollution gradient

    Energy Technology Data Exchange (ETDEWEB)

    Notten, M.J.M. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands)]. E-mail: martje.notten@ecology.falw.vu.nl; Oosthoek, A.J.P. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands); Rozema, J. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands); Aerts, R. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands)

    2005-11-15

    We investigated concentrations of Zn, Cu, Cd and Pb in the compartments of a soil-plant (Urtica dioica)-snail (Cepaea nemoralis) food chain in four polluted locations in the Biesbosch floodplains, the Netherlands, and two reference locations. Total soil metal concentrations in the polluted locations were 4-20 times higher than those in the reference locations. Positive relationships between the generally low leaf concentrations and the soil concentrations were found for Zn only (r {sup 2} = 0.20). Bioaccumulation of Zn, Cu and Cd was observed in the snail tissues. We found positive relationships between the snail and leaf concentrations for all metals (range r {sup 2} = 0.19-0.46). The relationships between soil and snail concentrations were also positive, except for Cu (range r {sup 2} = 0.15-0.33). These results suggest transfer of metals to C. nemoralis snails from U. dioica leaves and from the soil. Metal transfer from polluted leaves to C. nemoralis is more important than transfer from the soil. - Bioaccumulation and positive snail-leaf relationships suggest metal transfer from Urtica dioica leaves to Cepaea nemoralis snails.

  18. Heavy metal concentrations in a soil-plant-snail food chain along a terrestrial soil pollution gradient

    International Nuclear Information System (INIS)

    Notten, M.J.M.; Oosthoek, A.J.P.; Rozema, J.; Aerts, R.

    2005-01-01

    We investigated concentrations of Zn, Cu, Cd and Pb in the compartments of a soil-plant (Urtica dioica)-snail (Cepaea nemoralis) food chain in four polluted locations in the Biesbosch floodplains, the Netherlands, and two reference locations. Total soil metal concentrations in the polluted locations were 4-20 times higher than those in the reference locations. Positive relationships between the generally low leaf concentrations and the soil concentrations were found for Zn only (r 2 = 0.20). Bioaccumulation of Zn, Cu and Cd was observed in the snail tissues. We found positive relationships between the snail and leaf concentrations for all metals (range r 2 = 0.19-0.46). The relationships between soil and snail concentrations were also positive, except for Cu (range r 2 = 0.15-0.33). These results suggest transfer of metals to C. nemoralis snails from U. dioica leaves and from the soil. Metal transfer from polluted leaves to C. nemoralis is more important than transfer from the soil. - Bioaccumulation and positive snail-leaf relationships suggest metal transfer from Urtica dioica leaves to Cepaea nemoralis snails

  19. Epitope structure and binding affinity of single chain llama anti-β-amyloid antibodies revealed by proteolytic excision affinity-mass spectrometry.

    Science.gov (United States)

    Paraschiv, Gabriela; Vincke, Cécile; Czaplewska, Paulina; Manea, Marilena; Muyldermans, Serge; Przybylski, Michael

    2013-01-01

    ß-Amyloid (Aß) immunotherapy has become a promising strategy for reducing the level of Aß in brain. New immunological approaches have been recently proposed for rapid, early diagnosis, and molecular treatment of neurodegenerative diseases related to Alzheimer's Disease (AD). The combination of proteolytic epitope excision and extraction and mass spectrometry using digestion with various proteases has been shown to be an efficient tool for the identification and molecular characterization of antigenic determinants. Here, we report the identification of the Aβ epitope recognized by the variable domain of single chain llama anti-Aβ-antibodies, termed Aβ-nanobodies, that have been discovered in the blood of camelids and found to be promising candidates for immunotherapy of AD. The epitope recognized by two Aβ-specific nanobodies was identified by proteolytic epitope extraction- and excision-mass spectrometry using a series of proteases (trypsin, chymotrypsin, GluC-protease, and LysC-protease). Matrix-assisted laser desorption ionization--mass spectrometric analysis of the affinity--elution fraction provided the epitope, Aβ(17-28), in the mid- to carboxy-terminal domain of Aβ, which has been shown to exert an Aß-fibril inhibiting effect. Affinity studies of the synthetic epitope confirmed that the Aβ(17-28) peptide is the minimal fragment that binds to the nanobodies. The interactions between the nanobodies and full length Aβ(1-40) or Aβ-peptides containing or lacking the epitope sequence were further characterized by enzyme linked immunosorbent assay and bioaffinity analysis. Determinations of binding affinities between the Aβ-nanobodies and Aβ(1-40) and the Aβ(17-28) epitope provided K(D) values of approximately 150 and 700 nmol, respectively. Thus, the knowledge of the epitope may be highly useful for future studies of Aβ-aggregation (oligomerization and fibril formation) and for designing new aggregation inhibitors. Copyright © 2012 John Wiley

  20. Generation of Novel Single-Chain Antibodies by Phage-Display Technology to Direct Imaging Agents Highly Selective to Pancreatic β- or α-Cells In Vivo

    Science.gov (United States)

    Ueberberg, Sandra; Meier, Juris J.; Waengler, Carmen; Schechinger, Wolfgang; Dietrich, Johannes W.; Tannapfel, Andrea; Schmitz, Inge; Schirrmacher, Ralf; Köller, Manfred; Klein, Harald H.; Schneider, Stephan

    2009-01-01

    OBJECTIVE Noninvasive determination of pancreatic β-cell mass in vivo has been hampered by the lack of suitable β-cell–specific imaging agents. This report outlines an approach for the development of novel ligands homing selectively to islet cells in vivo. RESEARCH DESIGN AND METHODS To generate agents specifically binding to pancreatic islets, a phage library was screened for single-chain antibodies (SCAs) on rat islets using two different approaches. 1) The library was injected into rats in vivo, and islets were isolated after a circulation time of 5 min. 2) Pancreatic islets were directly isolated, and the library was panned in the islets in vitro. Subsequently, the identified SCAs were extensively characterized in vitro and in vivo. RESULTS We report the generation of SCAs that bind highly selective to either β- or α-cells. These SCAs are internalized by target cells, disappear rapidly from the vasculature, and exert no toxicity in vivo. Specific binding to β- or α-cells was detected in cell lines in vitro, in rats in vivo, and in human tissue in situ. Electron microscopy demonstrated binding of SCAs to the endoplasmatic reticulum and the secretory granules. Finally, in a biodistribution study the labeling intensity derived from [125I]-labeled SCAs after intravenous administration in rats strongly predicted the β-cell mass and was inversely related to the glucose excursions during an intraperitoneal glucose tolerance test. CONCLUSIONS Our data provide strong evidence that the presented SCAs are highly specific for pancreatic β-cells and enable imaging and quantification in vivo. PMID:19592622

  1. Expression and purification of a novel therapeutic single-chain variable fragment antibody against BNP from inclusion bodies of Escherichia coli.

    Science.gov (United States)

    Bu, Dawei; Zhou, Yuwei; Tang, Jian; Jing, Fang; Zhang, Wei

    2013-12-01

    Abnormal brain natriuretic peptide (BNP) secretion is regarded as the dominating mechanism of cerebral salt wasting syndrome (CSW), which results from a renal loss of sodium and water during intracranial disease leading to hyponatremia. Scale preparation of therapeutic single-chain variable fragment (scFv) that can neutralize elevated circulating BNP may have potential value for clinical use. In this report, we used a recently isolated humanized anti-BNP scFv fragment (3C1) as model antibody (Ab) to evaluate the potential of scale production of this therapeutic protein. The truncated gene encoding for scFv fragment cloned in pET22b (+) was mainly overexpressed as inclusion bodies in Escherichia coli (E. coli) Rosetta (DE3) pLysS cells. The insoluble fragment was solubilized and purified by Ni-NTA agarose resin under denaturation conditions, and recovered via an effective refolding buffer containing 50 mM Tris-HCl, pH 8.0, 0.15 M NaCl, 1 mM EDTA, 0.5 M arginine, 2 mM GSH, 1 mM GSSG, and 5% glycerol. The refolded scFv fragment was concentrated by PEG20000, and dialyzed in PBS (containing 5% glycerol, pH 7.4). The final yield was approximately 10.2 mg active scFv fragment per liter of culture (3.4 g wet weight cells). The scFv fragment was more than 95% pure assessed by SDS-PAGE assay. Recombinant scFv fragment with His tag displayed its immunoreactivity with anti-His tag Ab by western blotting. ELISA showed the scFv fragment specifically bound to BNP, and it displayed similar activity as the traditional anti-BNP monoclonal Ab (mAb). Thus, the current strategy allows convenient small-scale production of this therapeutic protein. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Enhancement of antitumor activity by using a fully human gene encoding a single-chain fragmented antibody specific for carcinoembryonic antigen

    Directory of Open Access Journals (Sweden)

    Shibaguchi H

    2017-08-01

    Full Text Available Hirotomo Shibaguchi,1,* Naixiang Luo,1,* Naoto Shirasu,1,* Motomu Kuroki,2 Masahide Kuroki1 1Department of Biochemistry, Faculty of Medicine, Fukuoka University, Fukuoka, Japan; 2School of Nursing, Faculty of Medicine, Fukuoka University, Fukuoka, Japan *These authors equally contributed to this work Abstract: Human leukocyte antigen and/or costimulatory molecules are frequently lacking in metastatic tumor cells, and thus tumor cells are able to escape from the immune system. Although lymphocytes with a chimeric antigen receptor (CAR is a promising approach for overcoming this challenge in cancer immunotherapy, administration of modified T cells alone often demonstrates little efficacy in patients. Therefore, in order to enhance the antitumor activity of immune cells in the cancer microenvironment, we used lymphocytes expressing CAR in combination with a fusion protein of IL-2 that contained the single-chain fragmented antibody (scFv specific for the carcinoembryonic antigen. Among a series of CAR constructs, with or without a spacer and the intracellular domain of CD28, the CAR construct containing CD8α, CD28, and CD3ζ most effectively activated and expressed INF-γ in CAR-bearing T cells. Furthermore, in comparison with free IL-2, the combination of peripheral blood mononuclear cells expressing CAR and the fusion protein containing IL-2 significantly enhanced the antitumor activity against MKN-45 cells, a human gastric cancer cell line. In conclusion, this novel combination therapy of CAR and a fusion protein consisting of a functional cytokine and a fully human scFv may be a promising approach for adoptive cancer immunotherapy. Keywords: chimeric antigen receptor, fusion protein, human scFv, CEA, combination therapy

  3. Identification of anti-CD98 antibody mimotopes for inducing antibodies with antitumor activity by mimotope immunization.

    Science.gov (United States)

    Saito, Misa; Kondo, Masahiro; Ohshima, Motohiro; Deguchi, Kazuki; Hayashi, Hideki; Inoue, Kazuyuki; Tsuji, Daiki; Masuko, Takashi; Itoh, Kunihiko

    2014-04-01

    A mimotope is an antibody-epitope-mimicking peptide retrieved from a phage display random peptide library. Immunization with antitumor antibody-derived mimotopes is promising for inducing antitumor immunity in hosts. In this study, we isolated linear and constrained mimotopes from HBJ127, a tumor-suppressing anti-CD98 heavy chain mAb, and determined their abilities for induction of antitumor activity equal to that of the parent antibody. We detected elevated levels of antipeptide responses, but failed to detect reactivity against native CD98-expressing HeLa cells in sera of immunized mice. Phage display panning and selection of mimotope-immunized mouse spleen-derived antibody Fab library showed that HeLa cell-reactive Fabs were successfully retrieved from the library. This finding indicates that native antigen-reactive Fab clones represented an undetectable minor population in mimotope-induced antibody repertoire. Functional and structural analysis of retrieved Fab clones revealed that they were almost identical to the parent antibody. From these results, we confirmed that mimotope immunization was promising for retrieving antitumor antibodies equivalent to the parent antibody, although the co-administration of adjuvant compounds such as T-cell epitope peptides and Toll-like receptor 4 agonist peptides is likely to be necessary for inducing stronger antitumor immunity than mimotope injection alone. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  4. Routinely used immunoassays do not detect circulating anti-GBM antibodies against native NC1 hexamer and EA epitope of the α3 chain of type IV collagen.

    Science.gov (United States)

    Clavarino, Giovanna; Gauthier, Arnaud; Hellmark, Thomas; Carron, Pierre-Louis; Giovannini, Diane; Colliard, Sophie; Dragon-Durey, Marie-Agnès; Segelmark, Mårten; Cesbron, Jean-Yves; Dumestre-Pérard, Chantal

    2018-04-12

    Detection of circulating anti-GBM antibodies has a key role for the diagnosis of Goodpasture syndrome but immunoassays using purified or recombinant alpha3(IV)NC1 as antigen do not recognize all anti-GBM antibodies. We show that anti-GBM antibodies directed against epitopes in their native conformation or cryptic epitopes are detected by indirect immunofluorescence. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Frequent expression loss of Inter-alpha-trypsin inhibitor heavy chain (ITIH) genes in multiple human solid tumors: A systematic expression analysis

    International Nuclear Information System (INIS)

    Hamm, Alexander; Knuechel, Ruth; Dahl, Edgar; Veeck, Juergen; Bektas, Nuran; Wild, Peter J; Hartmann, Arndt; Heindrichs, Uwe; Kristiansen, Glen; Werbowetski-Ogilvie, Tamra; Del Maestro, Rolando

    2008-01-01

    The inter-alpha-trypsin inhibitors (ITI) are a family of plasma protease inhibitors, assembled from a light chain – bikunin, encoded by AMBP – and five homologous heavy chains (encoded by ITIH1, ITIH2, ITIH3, ITIH4, and ITIH5), contributing to extracellular matrix stability by covalent linkage to hyaluronan. So far, ITIH molecules have been shown to play a particularly important role in inflammation and carcinogenesis. We systematically investigated differential gene expression of the ITIH gene family, as well as AMBP and the interacting partner TNFAIP6 in 13 different human tumor entities (of breast, endometrium, ovary, cervix, stomach, small intestine, colon, rectum, lung, thyroid, prostate, kidney, and pancreas) using cDNA dot blot analysis (Cancer Profiling Array, CPA), semiquantitative RT-PCR and immunohistochemistry. We found that ITIH genes are clearly downregulated in multiple human solid tumors, including breast, colon and lung cancer. Thus, ITIH genes may represent a family of putative tumor suppressor genes that should be analyzed in greater detail in the future. For an initial detailed analysis we chose ITIH2 expression in human breast cancer. Loss of ITIH2 expression in 70% of cases (n = 50, CPA) could be confirmed by real-time PCR in an additional set of breast cancers (n = 36). Next we studied ITIH2 expression on the protein level by analyzing a comprehensive tissue micro array including 185 invasive breast cancer specimens. We found a strong correlation (p < 0.001) between ITIH2 expression and estrogen receptor (ER) expression indicating that ER may be involved in the regulation of this ECM molecule. Altogether, this is the first systematic analysis on the differential expression of ITIH genes in human cancer, showing frequent downregulation that may be associated with initiation and/or progression of these malignancies

  6. Frequent expression loss of Inter-alpha-trypsin inhibitor heavy chain (ITIH genes in multiple human solid tumors: A systematic expression analysis

    Directory of Open Access Journals (Sweden)

    Werbowetski-Ogilvie Tamra

    2008-01-01

    Full Text Available Abstract Background The inter-alpha-trypsin inhibitors (ITI are a family of plasma protease inhibitors, assembled from a light chain – bikunin, encoded by AMBP – and five homologous heavy chains (encoded by ITIH1, ITIH2, ITIH3, ITIH4, and ITIH5, contributing to extracellular matrix stability by covalent linkage to hyaluronan. So far, ITIH molecules have been shown to play a particularly important role in inflammation and carcinogenesis. Methods We systematically investigated differential gene expression of the ITIH gene family, as well as AMBP and the interacting partner TNFAIP6 in 13 different human tumor entities (of breast, endometrium, ovary, cervix, stomach, small intestine, colon, rectum, lung, thyroid, prostate, kidney, and pancreas using cDNA dot blot analysis (Cancer Profiling Array, CPA, semiquantitative RT-PCR and immunohistochemistry. Results We found that ITIH genes are clearly downregulated in multiple human solid tumors, including breast, colon and lung cancer. Thus, ITIH genes may represent a family of putative tumor suppressor genes that should be analyzed in greater detail in the future. For an initial detailed analysis we chose ITIH2 expression in human breast cancer. Loss of ITIH2 expression in 70% of cases (n = 50, CPA could be confirmed by real-time PCR in an additional set of breast cancers (n = 36. Next we studied ITIH2 expression on the protein level by analyzing a comprehensive tissue micro array including 185 invasive breast cancer specimens. We found a strong correlation (p Conclusion Altogether, this is the first systematic analysis on the differential expression of ITIH genes in human cancer, showing frequent downregulation that may be associated with initiation and/or progression of these malignancies.

  7. Use of thermodynamic coupling between antibody-antigen binding and phospholipid acyl chain phase transition energetics to predict immunoliposome targeting affinity.

    Science.gov (United States)

    Klegerman, Melvin E; Zou, Yuejiao; Golunski, Eva; Peng, Tao; Huang, Shao-Ling; McPherson, David D

    2014-09-01

    Thermodynamic analysis of ligand-target binding has been a useful tool for dissecting the nature of the binding mechanism and, therefore, potentially can provide valuable information regarding the utility of targeted formulations. Based on a consistent coupling of antibody-antigen binding and gel-liquid crystal transition energetics observed for antibody-phosphatidylethanolamine (Ab-PE) conjugates, we hypothesized that the thermodynamic parameters and the affinity for antigen of the Ab-PE conjugates could be effectively predicted once the corresponding information for the unconjugated antibody is determined. This hypothesis has now been tested in nine different antibody-targeted echogenic liposome (ELIP) preparations, where antibody is conjugated to dipalmitoylphosphatidylethanolamine (DPPE) head groups through a thioether linkage. Predictions were satisfactory (affinity not significantly different from the population of values found) in five cases (55.6%), but the affinity of the unconjugated antibody was not significantly different from the population of values found in six cases (66.7%), indicating that the affinities of the conjugated antibody tended not to deviate appreciably from those of the free antibody. While knowledge of the affinities of free antibodies may be sufficient to judge their suitability as targeting agents, thermodynamic analysis may still provide valuable information regarding their usefulness for specific applications.

  8. Identification of high-mannose and multiantennary complex-type N-linked glycans containing alpha-galactose epitopes from Nurse shark IgM heavy chain.

    Science.gov (United States)

    Harvey, David J; Crispin, Max; Moffatt, Beryl E; Smith, Sylvia L; Sim, Robert B; Rudd, Pauline M; Dwek, Raymond A

    2009-11-01

    MALDI-TOF mass spectrometry, negative ion nano-electrospray MS/MS and exoglycosidase digestion were used to identify 36 N-linked glycans from 19S IgM heavy chain derived from the nurse shark (Ginglymostoma cirratum). The major glycan was the high-mannose compound, Man(6)GlcNAc(2) accompanied by small amounts of Man(5)GlcNAc(2), Man(7)GlcNAc(2) and Man(8)GlcNAc(2). Bi- and tri-antennary (isomer with a branched 3-antenna) complex-type glycans were also abundant, most contained a bisecting GlcNAc residue (beta1-->4-linked to the central mannose) and with varying numbers of alpha-galactose residues capping the antennae. Small amounts of monosialylated glycans were also found. This appears to be the first comprehensive study of glycosylation in this species of animal. The glycosylation pattern has implications for the mechanism of activation of the complement system by nurse shark IgM.

  9. Effects of chronic Akt/mTOR inhibition by rapamycin on mechanical overload-induced hypertrophy and myosin heavy chain transition in masseter muscle.

    Science.gov (United States)

    Umeki, Daisuke; Ohnuki, Yoshiki; Mototani, Yasumasa; Shiozawa, Kouichi; Fujita, Takayuki; Nakamura, Yoshiki; Saeki, Yasutake; Okumura, Satoshi

    2013-01-01

    To examine the effects of the Akt/mammalian target of rapamycin (mTOR) pathway on masseter muscle hypertrophy and myosin heavy chain (MHC) transition in response to mechanical overload, we analyzed the effects of bite-opening (BO) on the hypertrophy and MHC composition of masseter muscle of BO-rats treated or not treated with rapamycin (RAPA), a selective mTOR inhibitor. The masseter muscle weight in BO-rats was significantly greater than that in controls, and this increase was attenuated by RAPA treatment. Expression of slow-twitch MHC isoforms was significantly increased in BO-rats with/without RAPA treatment, compared with controls, but the magnitude of the increase was much smaller in RAPA-treated BO-rats. Phosphorylation of p44/42 MAPK (ERK1/2), which preserves fast-twitch MHC isoforms in skeletal muscle, was significantly decreased in BO-rats, but the decrease was abrogated by RAPA treatment. Calcineurin signaling is known to be important for masseter muscle hypertrophy and fast-to-slow MHC isoform transition, but expression of known calcineurin activity modulators was unaffected by RAPA treatment. Taken together, these results indicate that the Akt/mTOR pathway is involved in both development of masseter muscle hypertrophy and fast-to-slow MHC isoform transition in response to mechanical overload with inhibition of the ERK1/2 pathway and operates independently of the calcineurin pathway.

  10. Passive Repetitive Stretching for a Short Duration within a Week Increases Myogenic Regulatory Factors and Myosin Heavy Chain mRNA in Rats' Skeletal Muscles

    Directory of Open Access Journals (Sweden)

    Yurie Kamikawa

    2013-01-01

    Full Text Available Stretching is a stimulation of muscle growth. Stretching for hours or days has an effect on muscle hypertrophy. However, differences of continuous stretching and repetitive stretching to affect muscle growth are not well known. To clarify the difference of continuous and repetitive stretching within a short duration, we investigated the gene expression of muscle-related genes on stretched skeletal muscles. We used 8-week-old male Wistar rats ( for this study. Animals medial gastrocnemius muscle was stretched continuously or repetitively for 15 min daily and 4 times/week under anesthesia. After stretching, muscles were removed and total RNA was extracted. Then, reverse transcriptional quantitative real-time PCR was done to evaluate the mRNA expression of MyoD, myogenin, and embryonic myosin heavy chain (MyHC. Muscles, either stretched continuously or repetitively, increased mRNA expression of MyoD, myogenin, and embryonic MyHC more than unstretched muscles. Notably, repetitive stretching resulted in more substantial effects on embryonic MyHC gene expression than continuous stretching. In conclusion, passive stretching for a short duration within a week is effective in increasing myogenic factor expression, and repetitive stretching had more effects than continuous stretching for skeletal muscle on muscle growth. These findings are applicable in clinical muscle-strengthening therapy.

  11. The importance of subfragment 2 and C-terminus of myosin heavy chain for thick filament assembly in skeletal muscle cells.

    Science.gov (United States)

    Ojima, Koichi; Oe, Mika; Nakajima, Ikuyo; Shibata, Masahiro; Muroya, Susumu; Chikuni, Koichi; Hattori, Akihito; Nishimura, Takanori

    2015-04-01

    In skeletal muscle cells, myofibrillar proteins are highly organized into sarcomeres in which thick filaments interdigitate with thin filaments to generate contractile force. The size of thick filaments, which consist mainly of myosin molecules, is strictly controlled. However, little is known about the mechanisms by which myosin molecules assemble into thick filaments. Here, we assessed the ability of each domain of myosin heavy chain (Myh) to form thick filaments. We showed that exogenously expressed subfragment 2 (S2) + light meromyosin (LMM) of Myh was efficiently incorporated into thick filaments in muscle cells, although neither solely expressed S2 nor LMM targeted to thick filaments properly. In nonmuscle COS7 cells, S2+LMM formed more enlarged filaments/speckles than LMM. These results suggest that Myh filament formation is induced by S2 accompanying LMM. We further examined the effects of Myh C-terminus on thick filament assembly. C-terminal deletion mutants were incorporated not into entire thick filaments but rather into restricted regions of thick filaments. Our findings suggest that the elongation of myosin filaments to form thick filaments is regulated by S2 as well as C-terminus of LMM. © 2014 Japanese Society of Animal Science.

  12. Different regions of the immunoglobulin heavy-chain locus are involved in chromosomal translocations in distinct pathogenic forms of Burkitt lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Neri, A.; Barriga, F.; Knowles, D.M.; Magrath, I.T.; Dalla-Favera, R.

    1988-04-01

    The authors show that endemic (eBL), sporadic (sBL), and acquired immunodeficiency syndrome-associated (AIDS-BL) forms of Burkitt lymphoma (BL) carrying t(8; 14) chromosomal translocations display different breakpoints within the immunoglobulin heavy-chain locus (IGH) on chromosome 14. In sBL (7 out of 11) and AIDS-BL (5 out of 6), the breakpoints occurred within or near the IGH ..mu.. switch (S/sub mu/) region on chromosome 14 and within the c-myc locus (MYC) on chromosome 8. In most eBL (13 out of 16) the breakpoints were mapped within or 5' to the IGH joining J/sub H/ region on chromosome 14 and outside the MYC locus on chromosome 8. Cloning and sequencing of the (8; 14) chromosomal junctions from two eBL cell lines and one eBL biopsy sample show that the recombination do not involve IGH-specific recombination signals on chromosome 14 or homologous sequences on chromosome 8, suggesting that these events are not likely to be mediated by the same mechanisms or enzymes as in IGH rearrangements. In general, these data have implications for the timing of occurrence of chromosomal translocations during B-cell differentiation in different BL types.

  13. Aspirin and salicylate bind to immunoglobulin heavy chain binding protein (BiP) and inhibit its ATPase activity in human fibroblasts.

    Science.gov (United States)

    Deng, W G; Ruan, K H; Du, M; Saunders, M A; Wu, K K

    2001-11-01

    Salicylic acid (SA), an endogenous signaling molecule of plants, possesses anti-inflammatory and anti-neoplastic actions in human. Its derivative, aspirin, is the most commonly used anti-inflammatory and analgesic drug. Aspirin and sodium salicylate (salicylates) have been reported to have multiple pharmacological actions. However, it is unclear whether they bind to a cellular protein. Here, we report for the first time the purification from human fibroblasts of a approximately 78 kDa salicylate binding protein with sequence identity to immunoglobulin heavy chain binding protein (BiP). The Kd values of SA binding to crude extract and to recombinant BiP were 45.2 and 54.6 microM, respectively. BiP is a chaperone protein containing a polypeptide binding site recognizing specific heptapeptide sequence and an ATP binding site. A heptapeptide with the specific sequence displaced SA binding in a concentration-dependent manner whereas a control heptapeptide did not. Salicylates inhibited ATPase activity stimulated by this specific heptapeptide but did not block ATP binding or induce BiP expression. These results indicate that salicylates bind specifically to the polypeptide binding site of BiP in human cells that may interfere with folding and transport of proteins important in inflammation.

  14. Ginger extract mitigates ethanol-induced changes of alpha and beta - myosin heavy chain isoforms gene expression and oxidative stress in the heart of male wistar rats.

    Science.gov (United States)

    Shirpoor, Alireza; Zerehpoosh, Mitra; Ansari, Mohammad Hasan Khadem; Kheradmand, Fatemeh; Rasmi, Yousef

    2017-09-01

    The association between ethanol consumption and heart abnormalities, such as chamber dilation, myocyte damage, ventricular hypertrophy, and hypertension is well known. However, underlying molecular mediators involved in ethanol-induced heart abnormalities remain elusive. The aim of this study was to investigate the effect of chronic ethanol exposure on alpha and beta - myosin heavy chain (MHC) isoforms gene expression transition and oxidative stress in rats' heart. It was also planned to find out whether ginger extract mitigated the abnormalities induced by ethanol in rats' heart. Male wistar rats were divided into three groups of eight animals as follows: Control, ethanol, and ginger extract treated ethanolic (GETE) groups. After six weeks of treatment, the results revealed a significant increase in the β-MHC gene expression, 8- OHdG amount, and NADPH oxidase level. Furthermore, a significant decrease in the ratio of α-MHC/β-MHC gene expression to the amount of paraoxonase enzyme in the ethanol group compared to the control group was found. The consumption of Ginger extract along with ethanol ameliorated the changes in MHC isoforms gene expression and reduced the elevated amount of 8-OHdG and NADPH oxidase. Moreover, compared to the consumption of ethanol alone, it increased the paraoxonase level significantly. These findings indicate that ethanol-induced heart abnormalities may in part be associated with MHC isoforms changes mediated by oxidative stress, and that these effects can be alleviated by using ginger extract as an antioxidant molecule. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Proteomic demonstration of the recurrent presence of inter-alpha-inhibitor H4 heavy-chain during aspergillosis induced in an animal model.

    Science.gov (United States)

    Desoubeaux, Guillaume; Jourdan, Marie-Lise; Valera, Lionel; Jardin, Bénédicte; Hem, Sonia; Caille, Agnès; Cormier, Bénédicte; Marchand-Adam, Sylvain; Bailly, Éric; Diot, Patrice; Chandenier, Jacques

    2014-05-01

    Invasive pulmonary aspergillosis remains a matter of great concern in oncology/haematology, intensive care units and organ transplantation departments. Despite the availability of various diagnostic tools with attractive features, new markers of infection are required for better medical care. We therefore looked for potential pulmonary biomarkers of aspergillosis, by carrying out two-dimensional (2D) gel electrophoresis comparing the proteomes of bronchial-alveolar lavage fluids (BALF) from infected rats and from control rats presenting non-specific inflammation, both immunocompromised. A bioinformatic analysis of the 2D-maps revealed significant differences in the abundance of 20 protein spots (ANOVA P-valuevalue0.8). One of these proteins, identified by mass spectrometry, was considered of potential interest: inter-alpha-inhibitor H4 heavy-chain (ITIH4), characterised for the first time in this infectious context. Western blotting confirmed its overabundance in all infected BALF, particularly at early stages of murine aspergillosis. Further investigations were carried on rat serum, and confirmed that ITIH4 levels increased during experimental aspergillosis. Preliminary results in human samples strengthened this trend. To our knowledge, this is the first description of the involvement of ITIH4 in aspergillosis. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. Llama-Derived Single Domain Antibodies Specific for Abrus Agglutinin

    Science.gov (United States)

    Goldman, Ellen R.; Anderson, George P.; Zabetakis, Dan; Walper, Scott; Liu, Jinny L.; Bernstein, Rachael; Calm, Alena; Carney, James P.; O’Brien, Thomas W.; Walker, Jennifer L.; Garber, Eric A. E.

    2011-01-01

    Llama derived single domain antibodies (sdAb), the recombinantly expressed variable heavy domains from the unique heavy-chain only antibodies of camelids, were isolated from a library derived from llamas immunized with a commercial abrin toxoid preparation. Abrin is a potent toxin similar to ricin in structure, sequence and mechanism of action. The selected sdAb were evaluated for their ability to bind to commercial abrin as well as abrax (a recombinant abrin A-chain), purified abrin fractions, Abrus agglutinin (a protein related to abrin but with lower toxicity), ricin, and unrelated proteins. Isolated sdAb were also evaluated for their ability to refold after heat denaturation and ability to be used in sandwich assays as both capture and reporter elements. The best binders were specific for the Abrus agglutinin, showing minimal binding to purified abrin fractions or unrelated proteins. These binders had sub nM affinities and regained most of their secondary structure after heating to 95 °C. They functioned well in sandwich assays. Through gel analysis and the behavior of anti-abrin monoclonal antibodies, we determined that the commercial toxoid preparation used for the original immunizations contained a high percentage of Abrus agglutinin, explaining the selection of Abrus agglutinin binders. Used in conjunction with anti-abrin monoclonal and polyclonal antibodies, these reagents can fill a role to discriminate between the highly toxic abrin and the related, but much less toxic, Abrus agglutinin and distinguish between different crude preparations. PMID:22174977

  17. Single-Domain Antibodies and the Promise of Modular Targeting in Cancer Imaging and Treatment

    Directory of Open Access Journals (Sweden)

    María Elena Iezzi

    2018-02-01

    Full Text Available Monoclonal antibodies and their fragments have significantly changed the outcome of cancer in the clinic, effectively inhibiting tumor cell proliferation, triggering antibody-dependent immune effector cell activation and complement mediated cell death. Along with a continued expansion in number, diversity, and complexity of validated tumor targets there is an increasing focus on engineering recombinant antibody fragments for lead development. Single-domain antibodies (sdAbs, in particular those engineered from the variable heavy-chain fragment (VHH gene found in Camelidae heavy-chain antibodies (or IgG2 and IgG3, are the smallest fragments that retain the full antigen-binding capacity of the antibody with advantageous properties as drugs. For similar reasons, growing attention is being paid to the yet smaller variable heavy chain new antigen receptor (VNAR fragments found in Squalidae. sdAbs have been selected, mostly from immune VHH libraries, to inhibit or modulate enzyme activity, bind soluble factors, internalize cell membrane receptors, or block cytoplasmic targets. This succinct review is a compilation of recent data documenting the application of engineered, recombinant sdAb in the clinic as epitope recognition “modules” to build monomeric, dimeric and multimeric ligands that target, tag and stall solid tumor growth in vivo. Size, affinity, specificity, and the development profile of sdAbs drugs are seemingly consistent with desirable clinical efficacy and safety requirements. But the hepatotoxicity of the tetrameric anti-DR5-VHH drug in patients with pre-existing anti-drug antibodies halted the phase I clinical trial and called for a thorough pre-screening of the immune and poly-specific reactivities of the sdAb leads.

  18. Myosin heavy chain composition in the vastus lateralis muscle in relation to oxygen uptake and heart rate during cycling in humans.

    Science.gov (United States)

    Majerczak, J; Nieckarz, Z; Karasinski, J; Zoladz, J A

    2014-04-01

    In this study we examined the relationship between fast myosin heavy chain (MyHC2) content in the vastus lateralis and the rate of oxygen uptake (VO2) and heart rate (HR) increase during an incremental exercise in 38, young, healthy men. Prior to the exercise test, muscle biopsies were taken in order to evaluate the MyHC composition. It was found that during cycling performed below the lactate threshold (LT), a positive relationship between MyHC2 and the intercept of the oxygen uptake and power output (VO2-PO) relationship existed (r=0.49, P=0.002), despite no correlation between MyHC2 and the slope value of the VO2-PO relationship (r= -0.18, P=0.29). During cycling performed above the LT, MyHC2 correlated positively with the magnitude of the nonlinearity in the VO2-PO relationship; i.e. with the accumulated VO2'excess' (r=0.44, P=0.006) and peak VO2'excess' (r=0.44, P=0.006), as well as with the slope of the HR-PO relationship (r=0.49, P=0.002). We have concluded that a greater MyHC2 content in the vastus lateralis is accompanied by a higher oxygen cost of cycling during exercise performed below the LT. This seems to be related to the higher energy cost of the non-cross-bridge activities in the muscles possessing a greater proportion of MyHC2 content. In the case of heavy-intensity exercise, a higher MyHC2 content in the vastus lateralis is accompanied by greater non-linearity in the VO2-PO relationship, as well as a steeper increase in HR in the function of an increase of PO. This relationship can be explained by greater disturbances in metabolic stability in type II muscle fibres during exercise, resulting in a decrease of muscle mechanical efficiency and greater increase of heart rate at a given power output. Therefore, MyHC composition has an impact on the oxygen cost of cycling both below and above the LT.

  19. Preferrential rearrangement in normal rabbits of the 3' VHa allotype gene that is deleted in Alicia mutants; somatic hypermutation/conversion may play a major role in generating the heterogeneity of rabbit heavy chain variable region sequences.

    Science.gov (United States)

    Allegrucci, M; Young-Cooper, G O; Alexander, C B; Newman, B A; Mage, R G

    1991-02-01

    The rabbit is unique in having well-defined allotypes in the variable region of the heavy chain. Products of the VHa locus, (with alleles a1, a2, and a3), account for the majority of the serum immunoglobulins. A small percentage of the serum immunoglobulins are a-negative. In 1986, Kelus and Weiss described a mutation that depressed the expression of the Ig VH a2 genes in an a1/a2 rabbit. From this animal the Alicia rabbit strain was developed and the mutation was termed ali. We previously showed, using Southern analysis and the transverse alternating field electrophoresis technique, that the difference between the ali rabbit and normal is a relatively small deletion including some of the most 3' VH genes. The most JH proximal 3' VH1 genes in DNA from normal rabbits of a1, a2 and a3 haplotypes encode a1, a2 and a3 molecules respectively, and it has been suggested that these genes are responsible for allelic inheritance of VHa allotypes. The present study suggests that the 3' end of the VH locus probably plays a key role in regulation of VH gene expression in rabbits because VH gene(s) in this region are the target(s) of preferential VDJ rearrangements. This raises the possibility that mechanisms such as somatic gene conversion and hypermutation are at work to generate the antibody repertoire in this species. Our data support the view that the 3' VH1 gene may be the preferred target for rearrangement in normal rabbits, and for the normal chromosome in heterozygous ali animals. However, homozygous ali rabbits with a deletion that removed the a2-encoding VH1 on both chromosomes do survive, rearrange other VH genes and produce normal levels of immunoglobulins as well as a significant percentage of B cells which bear the a2 allotype. This challenges the view that one VH gene, VH1, is solely responsible for the inheritance pattern of VHa allotypes.

  20. Crystallization and preliminary crystallographic studies of the single-chain variable fragment of antibody chA21 in complex with an N-terminal fragment of ErbB2

    International Nuclear Information System (INIS)

    Liu, Yang; Zhou, Huihao; Zhu, Juanjuan; Gao, Yongxiang; Niu, Liwen; Liu, Jing; Teng, Maikun

    2009-01-01

    An antibody–antigen complex consisting of a single-chain variable fragment of the potential therapeutic antibody chA21 and an N-terminal fragment (residues 1–192) of the human ErbB2 extracellular domain was expressed, purified and crystallized. X-ray diffraction data were collected to 2.45 Å resolution. ErbB2 is a transmembrane tyrosine kinase, the overexpression of which causes abnormality and disorder in cell signalling and leads to cell transformation. Previously, an anti-ErbB2 single-chain chimeric antibody chA21 that specifically inhibits the growth of ErbB2-overexpressing cancer cells in vitro and in vivo was developed. Here, an antibody–antigen complex consisting of the single-chain variable fragment (scFv) of chA21 and an N-terminal fragment (residues 1–192, named EP I) of the ErbB2 extracellular domain was crystallized using the sitting-drop vapour-diffusion method. An X-ray diffraction data set was collected to 2.45 Å resolution from a single flash-cooled crystal; the crystal belonged to space group P2 1 2 1 2 1

  1. 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.

  2. The C-terminal amino acid of the MHC-I heavy chain is critical for binding to Derlin-1 in human cytomegalovirus US11-induced MHC-I degradation.

    Science.gov (United States)

    Cho, Sunglim; Kim, Bo Young; Ahn, Kwangseog; Jun, Youngsoo

    2013-01-01

    Derlin-1 plays a critical role in endoplasmic reticulum-associated protein degradation (ERAD) of a particular subset of proteins. Although it is generally accepted that Derlin-1 mediates the export of ERAD substrates from the ER to the cytosol, little is known about how Derlin-1 interacts with these substrates. Human cytomegalovirus (HCMV) US11 exploits Derlin-1-dependent ERAD to degrade major histocompatibility complex class I (MHC-I) molecules and evade immune surveillance. US11 requires the cytosolic tail of the MHC-I heavy chain to divert MHC-I molecules into the ERAD pathway for degradation; however, the underlying mechanisms remain unknown. Here, we show that the cytosolic tail of the MHC-I heavy chain, although not required for interaction with US11, is required for tight binding to Derlin-1 and thus for US11-induced dislocation of the MHC-I heavy chain to the cytosol for proteasomal degradation. Surprisingly, deletion of a single C-terminal amino acid from the cytosolic tail disrupted the interaction between MHC-I molecules and Derlin-1, rendering mutant MHC-I molecules resistant to US11-induced degradation. Consistently, deleting the C-terminal cytosolic region of Derlin-1 prevented it from binding to MHC-I molecules. Taken together, these results suggest that the cytosolic region of Derlin-1 is involved in ERAD substrate binding and that this interaction is critical for the Derlin-1-mediated dislocation of the MHC-I heavy chain to the cytosol during US11-induced MHC-I degradation.

  3. Levels of myosin heavy chain mRNA transcripts and protein isoforms in the fast extensor digitorum longus muscle of 7-month-old rats with chronic thyroid status alterations

    Czech Academy of Sciences Publication Activity Database

    Vadászová, Adriana; Hudecová, S.; Križanová, O.; Soukup, Tomáš

    2006-01-01

    Roč. 55, č. 6 (2006), s. 707-710 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/05/0327 Grant - others:VEGA(SK) 2/4106; NATO(XE) 979876; SAV(SK) APVT-51-027404; MYORES(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : myosin heavy chain isoforms * thyroid hormones * muscle differentiation Subject RIV: ED - Physiology Impact factor: 2.093, year: 2006

  4. [Construction of the lentiviral expression vector for anti-p185(erbB2) mouse/human chimeric antibody].

    Science.gov (United States)

    Liu, Fang; Li, Li; Zhang, Wei; Wang, Qi

    2013-04-01

    This research was to construct the lentiviral expression vector for anti- p185(erbB2) mouse/human chimeric antibody and to determine the expression of the chimeric antibody gene in 293T cells transfected with this vector. The genes (vL and vH) coding light and heavy chain of variable regions of anti-p185(erbB2) mAb and the constant regions of human IgG1 (kappa and gamma1) were cloned with PCR method. The target genes were assembled by three-primers PCR method to obtain the chimeric light chain (L) and the chimeric heavy chain (H). Both chains inserted into the down stream and upper stream of IRES gene of the plasmid pVAX1/IRES respectively. We digested the plasmid pVAX1/ H-IRES-L with endoenzyme and subcloned H-IRES-L into the lentiviral vector pWPI. The enzyme digestion and sequence analysis showed that the lentiviral expression vector pWPI/H-IRES-L was constructed correctly. Then, it was transfected into 293T cells and after 48h, GFP protein expression in 293T cells were detected by fluorescent microscope and the chimeric antibody expression was detected by RT-PCR and direct ELISA. The results showed that after 293T cells were transfected with recombination plasmid, both light and heavy chains of the chimeric antibody genes could express together. The chimeric antibody expressed could bind to p185(erbB2) specifically. This research may lay a sound foundation for further study of anti-p185(erbB2) engineered antibody.

  5. Binding of HIV-1 gp41-directed neutralizing and non-neutralizing fragment antibody binding domain (Fab and single chain variable fragment (ScFv antibodies to the ectodomain of gp41 in the pre-hairpin and six-helix bundle conformations.

    Directory of Open Access Journals (Sweden)

    John M Louis

    Full Text Available We previously reported a series of antibodies, in fragment antigen binding domain (Fab formats, selected from a human non-immune phage library, directed against the internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41. Broadly neutralizing antibodies from that series bind to both the fully exposed N-HR trimer, representing the pre-hairpin intermediate state of gp41, and to partially-exposed N-HR helices within the context of the gp41 six-helix bundle. While the affinities of the Fabs for pre-hairpin intermediate mimetics vary by only 2 to 20-fold between neutralizing and non-neutralizing antibodies, differences in inhibition of viral entry exceed three orders of magnitude. Here we compare the binding of neutralizing (8066 and non-neutralizing (8062 antibodies, differing in only four positions within the CDR-H2 binding loop, in Fab and single chain variable fragment (ScFv formats, to several pre-hairpin intermediate and six-helix bundle constructs of gp41. Residues 56 and 58 of the mini-antibodies are shown to be crucial for neutralization activity. There is a large differential (≥ 150-fold in binding affinity between neutralizing and non-neutralizing antibodies to the six-helix bundle of gp41 and binding to the six-helix bundle does not involve displacement of the outer C-terminal helices of the bundle. The binding stoichiometry is one six-helix bundle to one Fab or three ScFvs. We postulate that neutralization by the 8066 antibody is achieved by binding to a continuum of states along the fusion pathway from the pre-hairpin intermediate all the way to the formation of the six-helix bundle, but prior to irreversible fusion between viral and cellular membranes.

  6. CD98 Heavy Chain Is a Potent Positive Regulator of CD4+ T Cell Proliferation and Interferon-γ Production In Vivo.

    Directory of Open Access Journals (Sweden)

    Takeshi Kurihara

    Full Text Available Upon their recognition of antigens presented by the MHC, T cell proliferation is vital for clonal expansion and the acquisition of effector functions, which are essential for mounting adaptive immune responses. The CD98 heavy chain (CD98hc, Slc3a2 plays a crucial role in the proliferation of both CD4+ and CD8+ T cells, although it is unclear if CD98hc directly regulates the T cell effector functions that are not linked with T cell proliferation in vivo. Here, we demonstrate that CD98hc is required for both CD4+ T cell proliferation and Th1 functional differentiation. T cell-specific deletion of CD98hc did not affect T cell development in the thymus. CD98hc-deficient CD4+ T cells proliferated in vivo more slowly as compared with control T cells. C57BL/6 mice lacking CD98hc in their CD4+ T cells could not control Leishmania major infections due to lowered IFN-γ production, even with massive CD4+ T cell proliferation. CD98hc-deficient CD4+ T cells exhibited lower IFN-γ production compared with wild-type T cells, even when comparing IFN-γ expression in cells that underwent the same number of cell divisions. Therefore, these data indicate that CD98hc is required for CD4+ T cell expansion and functional Th1 differentiation in vivo, and suggest that CD98hc might be a good target for treating Th1-mediated immune disorders.

  7. Role of cyclic AMP sensor Epac1 in masseter muscle hypertrophy and myosin heavy chain transition induced by β2-adrenoceptor stimulation.

    Science.gov (United States)

    Ohnuki, Yoshiki; Umeki, Daisuke; Mototani, Yasumasa; Jin, Huiling; Cai, Wenqian; Shiozawa, Kouichi; Suita, Kenji; Saeki, Yasutake; Fujita, Takayuki; Ishikawa, Yoshihiro; Okumura, Satoshi

    2014-12-15

    The predominant isoform of β-adrenoceptor (β-AR) in skeletal muscle is β2-AR and that in the cardiac muscle is β1-AR. We have reported that Epac1 (exchange protein directly activated by cAMP 1), a new protein kinase A-independent cAMP sensor, does not affect cardiac hypertrophy in response to pressure overload or chronic isoproterenol (isoprenaline) infusion. However, the role of Epac1 in skeletal muscle hypertrophy remains poorly understood. We thus examined the effect of disruption of Epac1, the major Epac isoform in skeletal muscle, on masseter muscle hypertrophy induced by chronic β2-AR stimulation with clenbuterol (CB) in Epac1-null mice (Epac1KO). The masseter muscle weight/tibial length ratio was similar in wild-type (WT) and Epac1KO at baseline and was significantly increased in WT after CB infusion, but this increase was suppressed in Epac1KO. CB treatment significantly increased the proportion of myosin heavy chain (MHC) IIb at the expense of that of MHC IId/x in both WT and Epac1KO, indicating that Epac1 did not mediate the CB-induced MHC isoform transition towards the faster isoform. The mechanism of suppression of CB-mediated hypertrophy in Epac1KO is considered to involve decreased activation of Akt signalling. In addition, CB-induced histone deacetylase 4 (HDAC4) phosphorylation on serine 246 mediated by calmodulin kinase II (CaMKII), which plays a role in skeletal muscle hypertrophy, was suppressed in Epac1KO. Our findings suggest that Epac1 plays a role in β2-AR-mediated masseter muscle hypertrophy, probably through activation of both Akt signalling and CaMKII/HDAC4 signalling. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

  8. Regulation of an antisense RNA with the transition of neonatal to IIb myosin heavy chain during postnatal development and hypothyroidism in rat skeletal muscle.

    Science.gov (United States)

    Pandorf, Clay E; Jiang, Weihua; Qin, Anqi X; Bodell, Paul W; Baldwin, Kenneth M; Haddad, Fadia

    2012-04-01

    Postnatal development of fast skeletal muscle is characterized by a transition in expression of myosin heavy chain (MHC) isoforms, from primarily neonatal MHC at birth to primarily IIb MHC in adults, in a tightly coordinated manner. These isoforms are encoded by distinct genes, which are separated by ∼17 kb on rat chromosome 10. The neonatal-to-IIb MHC transition is inhibited by a hypothyroid state. We examined RNA products [mRNA, pre-mRNA, and natural antisense transcript (NAT)] of developmental and adult-expressed MHC genes (embryonic, neonatal, I, IIa, IIx, and IIb) at 2, 10, 20, and 40 days after birth in normal and thyroid-deficient rat neonates treated with propylthiouracil. We found that a long noncoding antisense-oriented RNA transcript, termed bII NAT, is transcribed from a site within the IIb-Neo intergenic region and across most of the IIb MHC gene. NATs have previously been shown to mediate transcriptional repression of sense-oriented counterparts. The bII NAT is transcriptionally regulated during postnatal development and in response to hypothyroidism. Evidence for a regulatory mechanism is suggested by an inverse relationship between IIb MHC and bII NAT in normal and hypothyroid-treated muscle. Neonatal MHC transcription is coordinately expressed with bII NAT. A comparative phylogenetic analysis also suggests that bII NAT-mediated regulation has been a conserved trait of placental mammals for most of the eutherian evolutionary history. The evidence in support of the regulatory model implicates long noncoding antisense RNA as a mechanism to coordinate the transition between neonatal and IIb MHC during postnatal development.

  9. The Ku Protein Complex Interacts with YY1, Is Up-Regulated in Human Heart Failure, and Represses α Myosin Heavy-Chain Gene Expression

    Science.gov (United States)

    Sucharov, Carmen C.; Helmke, Steve M.; Langer, Stephen J.; Perryman, M. Benjamin; Bristow, Michael; Leinwand, Leslie

    2004-01-01

    Human heart failure is accompanied by repression of genes such as α myosin heavy chain (αMyHC) and SERCA2A and the induction of fetal genes such as βMyHC and atrial natriuretic factor. It seems likely that changes in MyHC isoforms contribute to the poor contractility seen in heart failure, because small changes in isoform composition can have a major effect on the contractility of cardiac myocytes and the heart. Our laboratory has recently shown that YY1 protein levels are increased in human heart failure and that YY1 represses the activity of the human αMyHC promoter. We have now identified a region of the αMyHC promoter that binds a factor whose expression is increased sixfold in failing human hearts. Through peptide mass spectrometry, we identified this binding activity to be a heterodimer of Ku70 and Ku80. Expression of Ku represses the human αMyHC promoter in neonatal rat ventricular myocytes. Moreover, overexpression of Ku70/80 decreases αMyHC mRNA expression and increases skeletal α-actin. Interestingly, YY1 interacts with Ku70 and Ku80 in HeLa cells. Together, YY1, Ku70, and Ku80 repress the αMyHC promoter to an extent that is greater than that with YY1 or Ku70/80 alone. Our results suggest that Ku is an important factor in the repression of the human αMyHC promoter during heart failure. PMID:15367688

  10. Differential muscular myosin heavy chain expression of the pectoral and pelvic girdles during early growth in the king penguin (Aptenodytes patagonicus) chick.

    Science.gov (United States)

    Erbrech, Aude; Robin, Jean-Patrice; Guérin, Nathalie; Groscolas, René; Gilbert, Caroline; Martrette, Jean-Marc

    2011-06-01

    Continuous growth, associated with a steady parental food supply, is a general pattern in offspring development. So that young chicks can acquire their locomotor independence, this period is usually marked by a fast maturation of muscles, during which different myosin heavy chain (MyHC) isoforms are expressed. However, parental food provisioning may fluctuate seasonally, and offspring therefore face a challenge to ensure the necessary maturation of their tissues when energy is limited. To address this trade-off we investigated muscle maturation in both the pectoral and pelvic girdles of king penguin chicks. This species has an exceptionally long rearing period (1 year), which is prolonged when parental food provisioning is drastically reduced during the sub-Antarctic winter. Approximately 1 month post hatching, chicks acquire a functional pedestrian locomotion, which uses pelvic muscles, whereas swimming, which uses the pectoral muscles, only occurs 1 year later. We therefore tested the hypothesis that the MyHC content of the leg muscles reaches a mature state before those of the pectoral muscles. We found that leg muscle MyHC composition changed with the progressive acquisition of pedestrian locomotion, whereas pectoral muscle fibres reached their mature MyHC profile as early as hatching. Contrary to our predictions, the acquisition of the adult profile in pectoral muscles could be related to an early maturation of the contractile muscular proteins, presumably associated with early thermoregulatory capacities of chicks, necessary for survival in their cold environment. This differential maturation appears to reconcile both the locomotor and environmental constraints of king penguin chicks during growth.

  11. A mutation in the dynein heavy chain gene compensates for energy deficit of mutant SOD1 mice and increases potentially neuroprotective IGF-1

    Directory of Open Access Journals (Sweden)

    Larmet Yves

    2011-04-01

    Full Text Available Abstract Background Amyotrophic lateral sclerosis (ALS is a fatal neurodegenerative disease characterized by a progressive loss of motor neurons. ALS patients, as well as animal models such as mice overexpressing mutant SOD1s, are characterized by increased energy expenditure. In mice, this hypermetabolism leads to energy deficit and precipitates motor neuron degeneration. Recent studies have shown that mutations in the gene encoding the dynein heavy chain protein are able to extend lifespan of mutant SOD1 mice. It remains unknown whether the protection offered by these dynein mutations relies on a compensation of energy metabolism defects. Results SOD1(G93A mice were crossbred with mice harboring the dynein mutant Cramping allele (Cra/+ mice. Dynein mutation increased adipose stores in compound transgenic mice through increasing carbohydrate oxidation and sparing lipids. Metabolic changes that occurred in double transgenic mice were accompanied by the normalization of the expression of key mRNAs in the white adipose tissue and liver. Furthermore, Dynein Cra mutation rescued decreased post-prandial plasma triglycerides and decreased non esterified fatty acids upon fasting. In SOD1(G93A mice, the dynein Cra mutation led to increased expression of IGF-1 in the liver, increased systemic IGF-1 and, most importantly, to increased spinal IGF-1 levels that are potentially neuroprotective. Conclusions These findings suggest that the protection against SOD1(G93A offered by the Cramping mutation in the dynein gene is, at least partially, mediated by a reversal in energy deficit and increased IGF-1 availability to motor neurons.

  12. Skeletal muscle myosin heavy chain isoform content in relation to gonadal hormones and anabolic-catabolic balance in trained and untrained men.

    Science.gov (United States)

    Grandys, Marcin; Majerczak, Joanna; Karasinski, Janusz; Kulpa, Jan; Zoladz, Jerzy A

    2012-12-01

    Gonadal hormones and anabolic-catabolic hormone balance have potent influence on skeletal muscle tissue, but little is known about their action with regard to myosin heavy chain (MHC) transformation in humans. We investigated the relationship between skeletal muscle MHC isoform content in the vastus lateralis muscle and basal testosterone (T) concentration in 3 groups of subjects: endurance trained (E), sprint/strength trained (S), and untrained (U) young men. We have also determined basal sex hormone-binding globulin and cortisol (C) concentrations in untrained subjects to examine the relationship between MHC composition and the anabolic-catabolic hormone balance. Moreover, basal free testosterone (fT) and bioavailable testosterone (bio-T) concentrations were calculated for this subgroup. Despite significant differences in MHC isoform content (69.4 ± 2.39%, 61.4 ± 8.04%, and 37.5 ± 13.80% of MHC-2 for groups S, U, and E, respectively, Kruskal-Wallis: H = 18.58, p 0.5). We have also found that in the U group, type 2 MHC in the vastus lateralis muscle is positively correlated with basal fT:C ratio (r = 0.63, p = 0.01). It is concluded that the differences in the training history and training specificity can be distinguished with regard to the MHC composition but not with regard to the basal T concentration. Simultaneously, it has been shown that MHC isoform content in human vastus lateralis muscle may be related to basal anabolic-catabolic hormone balance, and this hypothesis needs further investigation.

  13. Contractile properties of motor units and expression of myosin heavy chain isoforms in rat fast-type muscle after volitional weight-lifting training.

    Science.gov (United States)

    Łochyński, Dawid; Kaczmarek, Dominik; Mrówczyński, Włodzimierz; Warchoł, Wojciech; Majerczak, Joanna; Karasiński, Janusz; Korostyński, Michał; Zoladz, Jerzy A; Celichowski, Jan

    2016-10-01

    Dynamic resistance training increases the force and speed of muscle contraction, but little is known about modifications to the contractile properties of the main physiological types of motor units (MUs) that contribute to these muscle adaptations. Although the contractile profile of MU muscle fibers is tightly coupled to myosin heavy chain (MyHC) protein expression, it is not well understood if MyHC transition is a prerequisite for modifications to the contractile characteristics of MUs. In this study, we examined MU contractile properties, the mRNA expression of MyHC, parvalbumin, and sarcoendoplasmic reticulum Ca 2+ pump isoforms, as well as the MyHC protein content after 5 wk of volitional progressive weight-lifting training in the medial gastrocnemius muscle in rats. The training had no effect on MyHC profiling or Ca 2+ -handling protein gene expression. Maximum force increased in slow (by 49%) and fast (by 21%) MUs. Within fast MUs, the maximum force increased in most fatigue-resistant and intermediate but not most fatigable MUs. Twitch contraction time was shortened in slow and fast fatigue-resistant MUs. Twitch half-relaxation was shortened in fast most fatigue-resistant and intermediate MUs. The force-frequency curve shifted rightward in fast fatigue-resistant MUs. Fast fatigable MUs fatigued less within the initial 15 s while fast fatigue-resistant units increased the ability to potentiate the force within the first minute of the standard fatigue test. In conclusion, at the early stage of resistance training, modifications to the contractile characteristics of MUs appear in the absence of MyHC transition and the upregulation of Ca 2+ -handling genes. Copyright © 2016 the American Physiological Society.

  14. Effective myotube formation in human adipose tissue-derived stem cells expressing dystrophin and myosin heavy chain by cellular fusion with mouse C2C12 myoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Young Woo [Cell Therapy and Tissue Engineering Center, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Biomedical Research Institute, Lifeliver Co., Ltd., Suwon (Korea, Republic of); Lee, Jong Eun; Yang, Mal Sook; Jang, In Keun; Kim, Hyo Eun; Lee, Doo Hoon; Kim, Young Jin [Biomedical Research Institute, Lifeliver Co., Ltd., Suwon (Korea, Republic of); Park, Won Jin [Dr. Park' s Aesthetic Clinic, Seoul (Korea, Republic of); Kong, Jee Hyun; Shim, Kwang Yong [Department of Hematology-Oncology, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Lee, Jong In, E-mail: oncochem@yonsei.ac.kr [Department of Hematology-Oncology, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Kim, Hyun Soo, E-mail: khsmd@unitel.co.kr [Department of Hematology-Oncology, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of)

    2011-04-29

    Highlights: {yields} hASCs were differentiated into skeletal muscle cells by treatment with 5-azacytidine, FGF-2, and the supernatant of cultured hASCs. {yields} Dystrophin and MyHC were expressed in late differentiation step by treatment with the supernatant of cultured hASCs. {yields} hASCs expressing dystrophin and MyHC contributed to myotube formation during co-culture with mouse myoblast C2C12 cells. -- Abstract: Stem cell therapy for muscular dystrophies requires stem cells that are able to participate in the formation of new muscle fibers. However, the differentiation steps that are the most critical for this process are not clear. We investigated the myogenic phases of human adipose tissue-derived stem cells (hASCs) step by step and the capability of myotube formation according to the differentiation phase by cellular fusion with mouse myoblast C2C12 cells. In hASCs treated with 5-azacytidine and fibroblast growth factor-2 (FGF-2) for 1 day, the early differentiation step to express MyoD and myogenin was induced by FGF-2 treatment for 6 days. Dystrophin and myosin heavy chain (MyHC) expression was induced by hASC conditioned medium in the late differentiation step. Myotubes were observed only in hASCs undergoing the late differentiation step by cellular fusion with C2C12 cells. In contrast, hASCs that were normal or in the early stage were not involved in myotube formation. Our results indicate that stem cells expressing dystrophin and MyHC are more suitable for myotube formation by co-culture with myoblasts than normal or early differentiated stem cells expressing MyoD and myogenin.

  15. Effect of 48-h food deprivation on the expressions of myosin heavy-chain isoforms and fiber type-related factors in rats.

    Science.gov (United States)

    Mizunoya, Wataru; Sawano, Shoko; Iwamoto, Yohei; Sato, Yusuke; Tatsumi, Ryuichi; Ikeuchi, Yoshihide

    2013-01-01

    The primary aim of this study was to examine the effects of 48-h food deprivation on rat skeletal muscle fiber type, according to myosin heavy-chain (MyHC) isoform composition and some metabolism-related factors in both slow-type dominant and fast-type dominant muscle tissues. Male Wistar rats (7 wk old) were treated with 48-h food deprivation or ad libitum feeding as control. After the treatment, the soleus muscle (slow-type dominant) and the extensor digitorum longus (EDL, fast-type dominant) were excised. We found that 48-h food deprivation did not affect MyHC composition in either the soleus or EDL, compared with fed rats by electrophoretic separation of MyHC isoforms. However, 48-h food deprivation significantly increased the mRNA expression of fast-type MyHC2B in the EDL muscle. Moreover, food deprivation increased fatty acid metabolism, as shown by elevated levels of related serum energy substrates and mRNA expression of mitochondrial uncoupling protein (UCP) 3 and lipoprotein lipase (LPL) in both the soleus and EDL. UCP3 and LPL are generally expressed at higher levels in slow-type fibers. Furthermore, we found that food deprivation significantly decreased the protein amounts of PGC1α and phosphorylated FOXO1, which are known as skeletal muscle fiber type regulators. In conclusion, 48-h food deprivation increased mRNA expression of fast-type MyHC isoform and oxidative metabolism-related factors in EDL, whereas MyHC composition at the protein level did not change in either the soleus or EDL.

  16. Effects of membrane properties on the binding activities of the HN and HC heavy-chain domains of botulinum neurotoxin A.

    Science.gov (United States)

    Ayyar, B Vijayalakshmi; Atassi, M Zouhair

    2016-12-01

    Binding behaviors of the H N and the H C domains of BoNT/A were investigated individually to identify if there exist any differences in their interaction with the cell membrane. Recombinant fragments corresponding to both BoNT/A H N and H C regions were prepared (H N 519-845 and H C 967-1296) and their binding to synaptic proteins was verified. The binding behaviors of these heavy-chain domains were analyzed by treating the Neuro 2a, a murine neuroblastoma cell line, with compounds known to alter membrane properties. Cholesterol depletion and lipid raft inhibition increased the binding of H N 519-845 to Neuro 2a cells without affecting H C 967-1296-cell interaction. Sphingolipid depletion decreased the binding of cells to both H C 967-1296 and H N 519-845 whereas, loading exogenous GD1a, on to the Neuro 2a cells, increased the binding of both the peptides to cells. Microtubule disruption of the Neuro 2a cells by nocodazole decreased the binding of both H C 967-1296 and H N 519-845 to the treated cells. Inhibition of the clathrin-mediated endocytosis using dynasore, chlorpromazine or potassium (K + ) depletion buffer lowered the binding of both H C 967-1296 and H N 519-845 to the cells, but seemed to exert a more pronounced effect on the binding of H C 967-1296 than on the binding of H N 519-845. Results indicate that while both the H N and H C domains are involved in the binding of the toxin to neuronal cells there are differences in their behavior which probably stem from their respective amino acid composition and structural location in the toxin three-dimensional structure along with their intended role in translocation and internalization into the cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Influence of injection of Chinese botulinum toxin type A on the histomorphology and myosin heavy chain composition of rat gastrocnemius muscles.

    Science.gov (United States)

    Hong, Bin; Chen, Min; Hu, Xing-yue

    2013-11-01

    Botulinum toxin type A (BoNT/A) is a metalloprotease that blocks synaptic transmission via the cleavage of a synaptosomal-associated protein of 25 kDa (SNAP-25). It has gained widespread use as a treatment for cerebral palsy and skeletal muscle hypertrophy. In China, Chinese botulinum toxin type A (CBTX-A), a type of BoNT/A, is in widespread clinical use. However, the changes in the morphological and biochemical properties of treated muscles and in remote muscles from the CBTX-A injection site are relatively unknown. Therefore, we investigated the changes in histomorphology and myosin heavy chain (MyHC) isoform composition and distribution in rat gastrocnemius muscles after intramuscular injection of CBTX-A. The weakness of the injected muscles was assessed periodically to identify their functional deficiency. Muscle slices were stained with hematoxylin-eosin (HE) and adenosine triphosphatase (ATPase). MyHC isoform composition was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to uncover changes in morphological and biochemical properties. Our findings demonstrate that following injection of CBTX-A 5 U into rat gastrocnemius muscles, shifts in MyHC isoform composition emerged on the third day after injection and peaked in the fourth week. The composition remained distinctly different from that of the control group after the twelfth week. More specifically, there was a decrease in the proportion of the type IIb isoform and an increase in the proportions of type IIx, type IIa, and type I isoforms. Data revealed that CBTX-A led to a shift in MyHC composition towards slower isoforms and that the MyHC composition remained far from normal six months after a single injection. However, no noticeable remote muscle weakness was induced.

  18. Effective myotube formation in human adipose tissue-derived stem cells expressing dystrophin and myosin heavy chain by cellular fusion with mouse C2C12 myoblasts

    International Nuclear Information System (INIS)

    Eom, Young Woo; Lee, Jong Eun; Yang, Mal Sook; Jang, In Keun; Kim, Hyo Eun; Lee, Doo Hoon; Kim, Young Jin; Park, Won Jin; Kong, Jee Hyun; Shim, Kwang Yong; Lee, Jong In; Kim, Hyun Soo

    2011-01-01

    Highlights: → hASCs were differentiated into skeletal muscle cells by treatment with 5-azacytidine, FGF-2, and the supernatant of cultured hASCs. → Dystrophin and MyHC were expressed in late differentiation step by treatment with the supernatant of cultured hASCs. → hASCs expressing dystrophin and MyHC contributed to myotube formation during co-culture with mouse myoblast C2C12 cells. -- Abstract: Stem cell therapy for muscular dystrophies requires stem cells that are able to participate in the formation of new muscle fibers. However, the differentiation steps that are the most critical for this process are not clear. We investigated the myogenic phases of human adipose tissue-derived stem cells (hASCs) step by step and the capability of myotube formation according to the differentiation phase by cellular fusion with mouse myoblast C2C12 cells. In hASCs treated with 5-azacytidine and fibroblast growth factor-2 (FGF-2) for 1 day, the early differentiation step to express MyoD and myogenin was induced by FGF-2 treatment for 6 days. Dystrophin and myosin heavy chain (MyHC) expression was induced by hASC conditioned medium in the late differentiation step. Myotubes were observed only in hASCs undergoing the late differentiation step by cellular fusion with C2C12 cells. In contrast, hASCs that were normal or in the early stage were not involved in myotube formation. Our results indicate that stem cells expressing dystrophin and MyHC are more suitable for myotube formation by co-culture with myoblasts than normal or early differentiated stem cells expressing MyoD and myogenin.

  19. Nucleotide sequences of the cDNAs encoding the V-regions of H- and L-chains of a human monoclonal antibody with broad reactivity to malignant tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Toshimitsu; Okajima, Hideki; Okumoto, Takeki [Yoshitomi Pharmaceutical Industries, Ltd., Saitama (Japan); Taniguchi, Masaru [Chiba Univ. (Japan)

    1989-06-12

    The human monoclonal antibody secreted from 4G12 hybridoma cells has broad reactivity to malignant tumor cells, especially for lung squamous cell carcinomas, and recognizes a new tumor-associated and differentiation antigen. The antigen detected by 4G12 is a glycoprotein with MW 195,000 and MW 65,000 under nonreducing and reducing conditions, respectively. Screening of a 4G12 {lambda}gt10 cDNA library with constant region probes for human immunoglobulin yielded full length clones for H- and L-chains. Nucleotide sequences revealed that subtypes of the variable regions were V{sub HIII} and {lambda}{sub 1}, respectively.

  20. FcγRII-binding Centyrins mediate agonism and antibody-dependent cellular phagocytosis when fused to an anti-OX40 antibody.

    Science.gov (United States)

    Zhang, Di; Whitaker, Brian; Derebe, Mehabaw G; Chiu, Mark L

    2018-04-01

    Immunostimulatory antibodies against the tumor necrosis factor receptors (TNFR) are emerging as promising cancer immunotherapies. The agonism activity of such antibodies depends on crosslinking to Fc gamma RIIB receptor (FcγRIIB) to enable the antibody multimerization that drives TNFR activation. Previously, Fc engineering was used to enhance the binding of such antibodies to Fcγ receptors. Here, we report the identification of Centyrins as alternative scaffold proteins with binding affinities to homologous FcγRIIB and FcγRIIA, but not to other types of Fcγ receptors. One Centyrin, S29, was engineered at distinct positions of an anti-OX40 SF2 antibody to generate bispecific and tetravalent molecules named as mAbtyrins. Regardless of the position of S29 on the SF2 antibody, SF2-S29 mAbtyrins could bind FcγRIIB and FcγRIIA specifically while maintaining binding to OX40 receptors. In a NFκB reporter assay, attachment of S29 Centyrin molecules at the C-termini, but not the N-termini, resulted in SF2 antibodies with increased agonism owing to FcγRIIB crosslinking. The mAbtyrins also showed agonism in T-cell activation assays with immobilized FcγRIIB and FcγRIIA, but this activity was confined to mAbtyrins with S29 specifically at the C-termini of antibody heavy chains. Furthermore, regardless of the position of the molecule, S29 Centyrin could equip an otherwise Fc-silent antibody with antibody-dependent cellular phagocytosis activity without affecting the antibody's intrinsic antibody-dependent cell-meditated cytotoxicity and complement-dependent cytotoxicity. In summary, the appropriate adoption FcγRII-binding Centyrins as functional modules represents a novel strategy to engineer therapeutic antibodies with improved functionalities.

  1. Efficient refolding and immobilization of PMMA-tag-fused single-chain Fv antibodies for sensitive immunological detection on a PMMA plate.

    Science.gov (United States)

    Kumada, Yoichi; Ishikawa, Yasuyuki; Fujiwara, Yusuke; Takeda, Rui; Miyamoto, Ryosuke; Niwa, Daisuke; Momose, Shun; Kang, Bongmun; Kishimoto, Michimasa

    2014-09-01

    In this study, we investigated the efficient refolding and site-specific immobilization of single-chain variable fragments (scFvs) genetically fused with a poly(methylmethacrylate)-binding peptide (PMMA-tag). According to the results of an aggregation test of a scFv-PM in the presence of 0.5 M urea, aggregation was hardly detectable at a weak-alkaline pH (8.5) with lower concentrations of NaCl. Consequently, more than 93% recovery of the anti-RNase scFv-PM model was attained, when it was refolded by dialysis against 50 mM TAPS (pH8.5). These results suggested that the apparent isoelectric point (pI) of a target scFv was decreased to a great extent by the genetic fusion of a PMMA-tag containing 5 acidic amino acids, and, thus, the solubility of the scFv-PM in its semi-denatured form was considerably improved. We also designed alternative peptide-tags composed of plural aspartic acid residues (D5, D10 and D15-tags) to decrease the apparent pI value of the fusion protein. As a consequence, scFv-D5, scFv-D10 and scFv-D15 were also efficiently refolded with yields of more than 95%. It is noteworthy that even scFv-PS-D15, which had both a positively charged polystyrene-binding peptide (PS-tag) and a negatively charged D15-tag, was serially connected at the C-terminal region of scFvs, and also refolded with a yield of 96.1%. These results clearly indicate that controlling the apparent pI value of scFvs by the fusion of oligo-peptides composed of acidic amino acids at the C-terminus resulted in a high degree of recovery via dialysis refolding. According to the results of a sandwich ELISA using scFv-PMs, scFv-D15 and scFv-PS-D15 as ligands, high antigen-binding signals were detected from both the PMMA and phi-PS plates immobilized with scFv-PMs. Furthermore, the high antigen-binding activity of scFv-PMs was maintained in an adsorption state when it was immobilized on the surface of not only PMMA, but also hydrophilic PS (phi-PS) and polycarbonate (PC). These results

  2. A monoclonal antibody against PDGF B-chain inhibits PDGF-induced DNA synthesis in C3H fibroblasts and prevents binding of PDGF to its receptor.

    Science.gov (United States)

    Vassbotn, F S; Langeland, N; Hagen, I; Holmsen, H

    1990-09-01

    A monoclonal antibody (MAb 6D11) against platelet-derived growth factor (PDGF) was studied. We found that the MAb 6D11 in concentrations equimolar to PDGF blocked the [3H]thymidine incorporation in C3H/10T1/2 C18 fibroblasts stimulated by PDGF B-B and PDGF A-B. This inhibition was overcome by high doses of PDGF. The [3H]thymidine incorporation stimulated by other growth factors (aFGF, bFGF and bombesin) was not inhibited by the antibody. The MAb 6D11 blocked receptor binding of PDGF B-B, but not PDGF A-A. These findings suggest that the MAb 6D11 abolishes PDGF-induced DNA synthesis by blocking PDGF receptor binding. In this communication we demonstrate an isoform-specific monoclonal antibody against PDGF.

  3. Naturally acquired Lawsonia intracellularis infection in pigs studied from weaning to slaughter by indirect immunofluorescence antibody test and polymerase chain reaction on faeces

    DEFF Research Database (Denmark)

    Jensen, Tim Kåre; Vigre, Håkan; Sørensen, Vibeke

    2005-01-01

    by immunofluorescence antibody test compared to 24% by immunohistochemistry on ileal samples. Thus, applied at the time of slaughter the antibody test appeared to be a highly sensitive ante-mortem diagnostic tool for identifying L. intracelluaris exposed pigs with or without current proliferative enteropathy. (c) 2004......The course of naturally acquired Lawsonia intracellularis infection was studied in 41 pigs by testing blood and faeces samples collected four to seven times from before weaning to slaughter 5 months old. At slaughter, a sample of ileum was taken for histopathology. In the first sampling when...... later on shed and/or were seropositive for L. intracellularis. The lowest prevalence of L. intracellularis was observed in 6-13 weeks old pigs and it seemed as though L. intracellularis in early infected pigs only activates a minor antibody response. At slaughter 66% of the pigs were found positive...

  4. Development of a Recombinant Antibody with Specificity for Chelated Uranyl Ions

    International Nuclear Information System (INIS)

    X. Li; A.M. Kriegel; T.C. Bishop; R.C. Blake; E. Figueiredo; H. Yu; D.A. Blake

    2005-01-01

    The goal of our project is to continue the development of new techniques for rapid, automated identification of radionuclides, metals, and chelators that may contaminant sur face and groundwater at DOE sites. One of the four specific aims of the present project is to develop new technologies in antibody engineering that will enhance our immunosensor program. Recombinant antibodies have potential advantages over monoclonal antibodies produced by standard hybridoma technology. The cloned genes represent a stable, recoverable source for antibody production. In addition, the recombinant format offers opportunities for protein engineering that enhances antibody performance and for studies that relate antibody sequence to binding activity. In this study, a hybridoma that synthesized an antibody (12F6) that recognized a 1:1 complex between 2,9-dicarboxyl-1,10- phenanthroline (DCP) and UO 2 2+ was used as a source of RNA for the development of a recombinant (Fab) 2 fragment. RNA was isolated from the 12F6 hybridoma and the cDNA encoding the entire κ light chain and the linked VH and C1 portions of the heavy chain were amplified from total RNA. cDNA sequences were verified by comparison with the N-terminal amino acid sequences of the light and heavy chains of the native 12F6 monoclonal antibody. A leader sequence and appropriate restriction sites were added to each chain, and the fragments were ligated into a commercial dicistronic vector (pBudCE4.1, Invitrogen, Inc.). COS-1 cells were transfected with this vector and the culture supernatant was assayed for activity and the (Fab) 2 protein. Cells transfected with vector containing 12F6 cDNA synthesized and secreted recombinant (Fab) 2 fragments that bound to the UO 2 2+ -DCP complex with an affinity indistinguishable from that of a (Fab) 2 fragment prepared from the native antibody. Molecular models of the heavy and light chain variable domains were constructed according to the canonical structures method detailed by Morea

  5. The European AntibotABE Framework Program and Its Update: Development of Innovative Botulinum Antibodies

    Directory of Open Access Journals (Sweden)

    Christine Rasetti-Escargueil

    2017-10-01

    Full Text Available The goal of the AntiBotABE Program was the development of recombinant antibodies that neutralize botulinum neurotoxins (BoNT A, B and E. These serotypes are lethal and responsible for most human botulinum cases. To improve therapeutic efficacy, the heavy and light chains (HC and LC of the three BoNT serotypes were targeted to achieve a synergistic effect (oligoclonal antibodies. For antibody isolation, macaques were immunized with the recombinant and non-toxic BoNT/A, B or E, HC or LC, followed by the generation of immune phage-display libraries. Antibodies were selected from these libraries against the holotoxin and further analyzed in in vitro and ex vivo assays. For each library, the best ex vivo neutralizing antibody fragments were germline-humanized and expressed as immunoglobulin G (IgGs. The IgGs were tested in vivo, in a standardized model of protection, and challenged with toxins obtained from collections of Clostridium strains. Protective antibody combinations against BoNT/A and BoNT/B were evidenced and for BoNT/E, the anti-LC antibody alone was found highly protective. The combination of these five antibodies as an oligoclonal antibody cocktail can be clinically and regulatorily developed while their high “humanness” predicts a high tolerance in humans.

  6. X-ray computed tomography imaging of a tumor with high sensitivity using gold nanoparticles conjugated to a cancer-specific antibody via polyethylene glycol chains on their surface

    Science.gov (United States)

    Nakagawa, Tomohiko; Gonda, Kohsuke; Kamei, Takashi; Cong, Liman; Hamada, Yoh; Kitamura, Narufumi; Tada, Hiroshi; Ishida, Takanori; Aimiya, Takuji; Furusawa, Naoko; Nakano, Yasushi; Ohuchi, Noriaki

    2016-01-01

    Contrast agents are often used to enhance the contrast of X-ray computed tomography (CT) imaging of tumors to improve diagnostic accuracy. However, because the iodine-based contrast agents currently used in hospitals are of low molecular weight, the agent is rapidly excreted from the kidney or moves to extravascular tissues through the capillary vessels, depending on its concentration gradient. This leads to nonspecific enhancement of contrast images for tissues. Here, we created gold (Au) nanoparticles as a new contrast agent to specifically image tumors with CT using an enhanced permeability and retention (EPR) effect. Au has a higher X-ray absorption coefficient than does iodine. Au nanoparticles were supported with polyethylene glycol (PEG) chains on their surface to increase the blood retention and were conjugated with a cancer-specific antibody via terminal PEG chains. The developed Au nanoparticles were injected into tumor-bearing mice, and the distribution of Au was examined with CT imaging, transmission electron microscopy, and elemental analysis using inductively coupled plasma optical emission spectrometry. The results show that specific localization of the developed Au nanoparticles in the tumor is affected by a slight difference in particle size and enhanced by the conjugation of a specific antibody against the tumor.

  7. Carbon-13 NMR study of switch variant anti-dansyl antibodies: Antigen binding and domain-domain interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Koichi; Matsunaga, Chigusa; Odaka, Asano; Yamato, Sumie; Takaha, Wakana; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo (Japan))

    1991-07-02

    A {sup 13}C NMR study is reported of switch variant anti-dansyl antibodies, which possess the identical V{sub H}, V{sub L}, and C{sub L} domains in conjunction with highly homologous but not identical heavy-chain constant regions. Each of the antibodies has been selectively labeled with {sup 13}C at the carbonyl carbon of Trp, Tyr, His, or Cys residue by growing hybridoma cells in serum-free medium. Spectral assignments have been made by folowing the procedure described previously for the switch variant antibodies labeled with (1-{sup 13}C)Met. On the basis of the spectral data collected for the antibodies and their proteolytic fragments, the authors discuss how {sup 13}C NMR spectroscopy can be used for the structural analyses of antigen binding and also of domain-domain interactions in the antibody molecule.

  8. Carbon-13 NMR study of switch variant anti-dansyl antibodies: Antigen binding and domain-domain interactions

    International Nuclear Information System (INIS)

    Kato, Koichi; Matsunaga, Chigusa; Odaka, Asano; Yamato, Sumie; Takaha, Wakana; Shimada, Ichio; Arata, Yoji

    1991-01-01

    A 13 C NMR study is reported of switch variant anti-dansyl antibodies, which possess the identical V H , V L , and C L domains in conjunction with highly homologous but not identical heavy-chain constant regions. Each of the antibodies has been selectively labeled with 13 C at the carbonyl carbon of Trp, Tyr, His, or Cys residue by growing hybridoma cells in serum-free medium. Spectral assignments have been made by folowing the procedure described previously for the switch variant antibodies labeled with [1- 13 C]Met. On the basis of the spectral data collected for the antibodies and their proteolytic fragments, the authors discuss how 13 C NMR spectroscopy can be used for the structural analyses of antigen binding and also of domain-domain interactions in the antibody molecule

  9. All-trans retinoic acid increases the expression of oxidative myosin heavy chain through the PPARδ pathway in bovine muscle cells derived from satellite cells.

    Science.gov (United States)

    Kim, Jongkyoo; Wellmann, Kimberly B; Smith, Zachary K; Johnson, Bradley J

    2018-04-24

    All-trans retinoic acid (ATRA) has been associated with various physiological phenomenon in mammalian adipose tissue and skeletal muscle. We hypothesized that ATRA may affect skeletal muscle fiber type in bovine satellite cell culture through various transcriptional processes. Bovine primary satellite cell (BSC) culture experiments were conducted to determine dose effects of ATRA on expression of genes and protein levels related to skeletal muscle fiber type and metabolism. The semimembranosus from crossbred steers (n = 2 steers), aged approximately 24 months, were used to isolate BSC for 3 separate assays. Myogenic differentiation was induced using 3% horse serum upon cultured BSC with increasing doses (0, 1, 10, 100, 1000 nM) of ATRA. After 96 h of incubation, cells were harvested and used to measure the gene expression of protein kinase B (Akt), AMP-activated protein kinase alpha (AMPK), glucose transporter 4 (GLUT4), myogenin, lipoprotein lipase (LPL), myosin heavy chain (MHC) I, MHC IIA,MHC IIX, insulin like growth factor -1 (IGF-1), Peroxisome proliferator activated receptor gamma (PPARγ), PPARδ, and Smad transcription factor 3 (SMAD3) mRNA relative to ribosomal protein subunit 9 (RPS9). The mRNA expression of LPL was increased (P < 0.05) with 100 and 1000nM of ATRA. Expression of GLUT4 was altered (P < 0.05) by ATRA. The treatment of ATRA (1000nM) also increased (P < 0.05) mRNA gene expression of SMAD3. The gene expression of both PPARδ and PPARγ were increased (P < 0.05) with 1000nM of ATRA. Protein level of PPARδ was also affected (P < 0.05) by 1000nM of ATRA and resulted in a greater (P < 0.05) protein level of PPARδ compared to CON. All-trans retinoic acid (10nM) increased gene expression of MHC I (P < 0.05) compared to CON. Expression of MHC IIA was also influenced (P < 0.05) by ATRA. The mRNA expression of MHC IIX was decreased (P < 0.05) with 100 and 1000nM of ATRA.In muscle cells, ATRA may cause muscle fibers to transition towards the MHC

  10. Inter-alpha-trypsin inhibitor heavy chain 4: a novel biomarker for environmental exposure to particulate air pollution in patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Lee KY

    2015-04-01

    Full Text Available Kang-Yun Lee,1–3 Po-Hao Feng,1,2 Shu-Chuan Ho,4 Kai-Jen Chuang,5,6 Tzu-Tao Chen,2,3 Chien-Ling Su,2,4 Wen-Te Liu,2,4 Hsiao-Chi Chuang2,4 1Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, 2Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, 3Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, 4School of Respiratory Therapy, College of Medicine, Taipei Medical University, 5Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, 6School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan Abstract: Chronic obstructive pulmonary disease (COPD is a chronic inflammatory disease that is correlated with environmental stress. Particulate matter ≤10 µm (PM10 is considered to be a risk factor for COPD development; however, the effects of PM10 on the protein levels in COPD remain unclear. Fifty subjects with COPD and 15 healthy controls were recruited. Gene ontology analysis of differentially expressed proteins identified immune system process and binding as the most important biological process and molecular function, respectively, in the responses of PM10-exposed patients with COPD. Biomarkers for PM10 in COPD were identified and compared with the same in healthy controls and included proteoglycan 4 (PRG4, inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4, and apolipoprotein F (APOF. PRG4 and ITIH4 were associated with a past 3-year PM10 exposure level. The receiver operating characteristic curve analysis showed that ITIH4 is a sensitive and specific biomarker for PM10 exposure (area under the curve [AUC] =0.690, P=0.015 compared with PRG4 (AUC =0.636, P=0.083, APOF (AUC =0.523, P=0.766, 8-isoprostane (AUC =0.563, P=0.405, and C-reactive protein (CRP; AUC =0.634, P=0.086. ITIH4 levels were correlated with CRP (r=0

  11. Effect of pedaling rates and myosin heavy chain composition in the vastus lateralis muscle on the power generating capability during incremental cycling in humans.

    Science.gov (United States)

    Majerczak, J; Szkutnik, Z; Duda, K; Komorowska, M; Kolodziejski, L; Karasinski, J; Zoladz, J A

    2008-01-01

    In this study, we have determined power output reached at maximal oxygen uptake during incremental cycling exercise (P(I, max)) performed at low and at high pedaling rates in nineteen untrained men with various myosin heavy chain composition (MyHC) in the vastus lateralis muscle. On separate days, subjects performed two incremental exercise tests until exhaustion at 60 rev min(-1) and at 120 rev min(-1). In the studied group of subjects P(I, max) reached during cycling at 60 rev min(-1) was significantly higher (p=0.0001) than that at 120 rev min(-1) (287+/-29 vs. 215+/-42 W, respectively for 60 and 120 rev min(-1)). For further comparisons, two groups of subjects (n=6, each) were selected according to MyHC composition in the vastus lateralis muscle: group H with higher MyHC II content (56.8+/-2.79 %) and group L with lower MyHC II content in this muscle (28.6+/-5.8 %). P(I, max) reached during cycling performed at 60 rev min(-1) in group H was significantly lower than in group L (p=0.03). However, during cycling at 120 rev min(-1), there was no significant difference in P(I, max) reached by both groups of subjects (p=0.38). Moreover, oxygen uptake (VO(2)), blood hydrogen ion [H(+)], plasma lactate [La(-)] and ammonia [NH(3)] concentrations determined at the four highest power outputs completed during the incremental cycling performed at 60 as well as 120 rev min(-1), in the group H were significantly higher than in group L. We have concluded that during an incremental exercise performed at low pedaling rates the subjects with lower content of MyHC II in the vastus lateralis muscle possess greater power generating capabilities than the subjects with higher content of MyHC II. Surprisingly, at high pedaling rate, power generating capabilities in the subjects with higher MyHC II content in the vastus lateralis muscle did not differ from those found in the subjects with lower content of MyHC II in this muscle, despite higher blood [H(+)], [La(-)] and [NH(3

  12. Single-Domain Antibodies As Versatile Affinity Reagents for Analytical and Diagnostic Applications

    Directory of Open Access Journals (Sweden)

    Gualberto Gonzalez-Sapienza

    2017-08-01

    Full Text Available With just three CDRs in their variable domains, the antigen-binding site of camelid heavy-chain-only antibodies (HcAbs has a more limited structural diversity than that of conventional antibodies. Even so, this does not seem to limit their specificity and high affinity as HcAbs against a broad range of structurally diverse antigens have been reported. The recombinant form of their variable domain [nanobody (Nb] has outstanding properties that make Nbs, not just an alternative option to conventional antibodies, but in many cases, these properties allow them to reach analytical or diagnostic performances that cannot be accomplished with conventional antibodies. These attributes include comprehensive representation of the immune specificity in display libraries, easy adaptation to high-throughput screening, exceptional stability, minimal size, and versatility as affinity building block. Here, we critically reviewed each of these properties and highlight their relevance with regard to recent developments in different fields of immunosensing applications.

  13. Antibody modeling using the prediction of immunoglobulin structure (PIGS) web server [corrected].

    Science.gov (United States)

    Marcatili, Paolo; Olimpieri, Pier Paolo; Chailyan, Anna; Tramontano, Anna

    2014-12-01

    Antibodies (or immunoglobulins) are crucial for defending organisms from pathogens, but they are also key players in many medical, diagnostic and biotechnological applications. The ability to predict their structure and the specific residues involved in antigen recognition has several useful applications in all of these areas. Over the years, we have developed or collaborated in developing a strategy that enables researchers to predict the 3D structure of antibodies with a very satisfactory accuracy. The strategy is completely automated and extremely fast, requiring only a few minutes (∼10 min on average) to build a structural model of an antibody. It is based on the concept of canonical structures of antibody loops and on our understanding of the way light and heavy chains pack together.

  14. Human Cell Line-Derived Monoclonal IgA Antibodies for Cancer Immunotherapy

    Directory of Open Access Journals (Sweden)

    Felix Hart

    2017-05-01

    Full Text Available IgA antibodies have great potential to improve the functional diversity of current IgG antibody-based cancer immunotherapy options. However, IgA production and purification is not well established, which can at least in part be attributed to the more complex glycosylation as compared to IgG antibodies. IgA antibodies possess up to five N-glycosylation sites within their constant region of the heavy chain as compared to one site for IgG antibodies. The human GlycoExpress expression system was developed to produce biotherapeutics with optimized glycosylation and used here to generate a panel of IgA isotype antibodies directed against targets for solid (TA-mucin 1, Her2, EGFR, Thomsen–Friedenreich and hematological (CD20 cancer indications. The feasibility of good manufacturing practice was shown by the production of 11 g IgA within 35 days in a one liter perfusion bioreactor, and IgA antibodies in high purity were obtained after purification. The monoclonal IgA antibodies possessed a high sialylation degree, and no non-human glycan structures were detected. Kinetic analysis revealed increased avidity antigen binding for IgA dimers as compared to monomeric antibodies. The IgA antibodies exhibited potent Fab- and Fc-mediated functionalities against cancer cell lines, whereby especially granulocytes are recruited. Therefore, for patients who do not sufficiently benefit from therapeutic IgG antibodies, IgA antibodies may complement current regiment options and represent a promising strategy for cancer immunotherapy. In conclusion, a panel of novel biofunctional IgA antibodies with human glycosylation was successfully generated.

  15. COAXIAL DISK SHUNT FOR MEASURING IN THE HEAVY-CURRENT CHAIN OF HIGH-VOLTAGE GENERATOR OF STORM DISCHARGES OF IMPULSES OF CURRENT OF ARTIFICIAL LIGHTNING WITH THE INTEGRAL OF ACTION TO 15•106 J/OHM

    Directory of Open Access Journals (Sweden)

    M. I. Baranov

    2017-10-01

    Full Text Available Purpose. Description of construction and basic technical descriptions developed and created in Research & Design Institute «Molniya» National Technical University «Kharkiv Polytechnic Institute» high-voltage heavy-current coaxial disk shunt of type of SC-300M2, allowing reliably to measure the peak-temporal parameters (PTP of impulses of current of artificial lightning in wide peak and temporal ranges with the integral of their action to 15·106 J/Ohm. Methodology. Electrophysics bases of high-voltage impulsive technique, scientific and technical bases of development and creation of high-voltage heavy-current impulsive electrical equipment, including the powerful generators of current of lightning (GCL, and also measuring methods in bit chains powerful high-voltage GCL AVP large impulsive currents of micro- and millisecond temporal ranges. Results. Offered and described new construction of measuring high-voltage heavy-current shunt, containing a measuring round disk from stainless steel easily soiled a 12Х18Н10Т thickness 2 mm and external diameter 80 mm. Experimental a way impulsive active resistance of RS≈0,08 mOhm of the indicated measuring disk and on his basis a calculation coefficient transformation is found of SS of coaxial disk shunt of type of SC-300M2, numeral equal in the concerted mode of operations of his coaxial cable line (CCL SS≈2/RS≈25·103 A/V. It is rotined that it is expedient to use this value SS for measuring in the heavy-current bit chain of GCL ATP impulsive A- and repeated impulsive D- component of current of artificial lightning, and also ATP of aperiodic impulse of current of artificial lightning of temporal form 10 μc/350 μc. It is set that taking into account application in the end CCL of shunt of a co-ordinate divizor of voltage with two output coaxial sockets 1:1 (for SSA≈25·103 A/V and 1:2 (SSC≈12,5·103 A/V at measuring of ATP intermediate B-, protracted C- and shortened protracted C

  16. Whole-Chain Tick Saliva Proteins Presented on Hepatitis B Virus Capsid-Like Particles Induce High-Titered Antibodies with Neutralizing Potential.

    Directory of Open Access Journals (Sweden)

    Philipp Kolb

    Full Text Available Ticks are vectors for various, including pathogenic, microbes. Tick saliva contains multiple anti-host defense factors that enable ticks their bloodmeals yet also facilitate microbe transmission. Lyme disease-causing borreliae profit specifically from the broadly conserved tick histamine release factor (tHRF, and from cysteine-rich glycoproteins represented by Salp15 from Ixodes scapularis and Iric-1 from Ixodes ricinus ticks which they recruit to their outer surface protein C (OspC. Hence these tick proteins are attractive targets for anti-tick vaccines that simultaneously impair borrelia transmission. Main obstacles are the tick proteins´ immunosuppressive activities, and for Salp15 orthologs, the lack of efficient recombinant expression systems. Here, we exploited the immune-enhancing properties of hepatitis B virus core protein (HBc derived capsid-like particles (CLPs to generate, in E. coli, nanoparticulate vaccines presenting tHRF and, as surrogates for the barely soluble wild-type proteins, cysteine-free Salp15 and Iric-1 variants. The latter CLPs were exclusively accessible in the less sterically constrained SplitCore system. Mice immunized with tHRF CLPs mounted a strong anti-tHRF antibody response. CLPs presenting cysteine-free Salp15 and Iric-1 induced antibodies to wild-type, including glycosylated, Salp15 and Iric-1. The broadly distributed epitopes included the OspC interaction sites. In vitro, the anti-Salp15 antibodies interfered with OspC binding and enhanced human complement-mediated killing of Salp15 decorated borreliae. A mixture of all three CLPs induced high titered antibodies against all three targets, suggesting the feasibility of combination vaccines. These data warrant in vivo validation of the new candidate vaccines´ protective potential against tick infestation and Borrelia transmission.

  17. Whole-Chain Tick Saliva Proteins Presented on Hepatitis B Virus Capsid-Like Particles Induce High-Titered Antibodies with Neutralizing Potential

    Science.gov (United States)

    Kolb, Philipp; Wallich, Reinhard; Nassal, Michael

    2015-01-01

    Ticks are vectors for various, including pathogenic, microbes. Tick saliva contains multiple anti-host defense factors that enable ticks their bloodmeals yet also facilitate microbe transmission. Lyme disease-causing borreliae profit specifically from the broadly conserved tick histamine release factor (tHRF), and from cysteine-rich glycoproteins represented by Salp15 from Ixodes scapularis and Iric-1 from Ixodes ricinus ticks which they recruit to their outer surface protein C (OspC). Hence these tick proteins are attractive targets for anti-tick vaccines that simultaneously impair borrelia transmission. Main obstacles are the tick proteins´ immunosuppressive activities, and for Salp15 orthologs, the lack of efficient recombinant expression systems. Here, we exploited the immune-enhancing properties of hepatitis B virus core protein (HBc) derived capsid-like particles (CLPs) to generate, in E. coli, nanoparticulate vaccines presenting tHRF and, as surrogates for the barely soluble wild-type proteins, cysteine-free Salp15 and Iric-1 variants. The latter CLPs were exclusively accessible in the less sterically constrained SplitCore system. Mice immunized with tHRF CLPs mounted a strong anti-tHRF antibody response. CLPs presenting cysteine-free Salp15 and Iric-1 induced antibodies to wild-type, including glycosylated, Salp15 and Iric-1. The broadly distributed epitopes included the OspC interaction sites. In vitro, the anti-Salp15 antibodies interfered with OspC binding and enhanced human complement-mediated killing of Salp15 decorated borreliae. A mixture of all three CLPs induced high titered antibodies against all three targets, suggesting the feasibility of combination vaccines. These data warrant in vivo validation of the new candidate vaccines´ protective potential against tick infestation and Borrelia transmission. PMID:26352137

  18. Llama VHH antibody fragments against GFAP: better diffusion in fixed tissues than classical monoclonal antibodies.

    Science.gov (United States)

    Perruchini, Claire; Pecorari, Frederic; Bourgeois, Jean-Pierre; Duyckaerts, Charles; Rougeon, François; Lafaye, Pierre

    2009-11-01

    Camelids produce antibodies made of homodimeric heavy chains, and the antigen-binding region being composed of a single domain called VHH. These VHHs are much smaller than complete IgG. They are also more thermostable and more soluble in water; they should, therefore, diffuse more readily in the tissues. VHHs, expressed in bacteria, are easier to produce than conventional monoclonal antibodies. Because of these special characteristics, these antibody fragments could have interesting developments in immunohistochemistry and in the development of biomarkers. To test the possibility of their use in immunohistochemistry (IHC), we selected the glial fibrillary acidic protein (GFAP), a well-known marker of astrocytes. One alpaca (Lama pacos) was immunized against GFAP. Lymphocytes were isolated; the DNA was extracted; the VHH-coding sequences were selectively amplified. Three VHHs with a high affinity for GFAP and their corresponding mRNA were selected by ribosome display. Large quantities of the recombinant VHHs coupled with different tags were harvested from transfected bacteria. One of them was shown to immunolabel strongly and specifically to GFAP of human astrocytes in tissue sections. The quality of the IHC was comparable or, in some aspects, superior to the quality obtained with conventional IgG. The VHH was shown to diffuse on a longer distance than conventional monoclonal antibodies in fixed cortical tissue: a property that may be useful in immunolabeling of thick sections.

  19. Antimitochondrial antibody

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003529.htm Antimitochondrial antibody To use the sharing features on this page, please enable JavaScript. Antimitochondrial antibodies (AMA) are substances ( antibodies ) that form against mitochondria. ...

  20. Site-specific antibodies distinguish single amino acid substitutions in position 57 in HLA-DQ beta-chain alleles associated with insulin-dependent diabetes

    DEFF Research Database (Denmark)

    Atar, D; Dyrberg, T; Michelsen, Birgitte

    1989-01-01

    The HLA-DQ beta-chain gene shows a close association with susceptibility or resistance to autoimmune insulin-dependent diabetes mellitus (IDDM) and it has been suggested that the amino acid in position 57 may be of pathogenetic importance. To study the expression of the IDDM associated HLA-DQ beta......-chain alleles, we immunized rabbits with 12 to 13 amino acid long peptides representing HLA-DQw7 and -DQw8 allelic sequences, differing only by one amino acid in position 57 being aspartic acid (Asp) and alanine (Ala), respectively. Immunoblot analysis of lymphoblastoid cells showed that several antisera...

  1. Real Time RT-PCR with a Newly Designed Set of Promers Confirmed the Presence of 2b and 2x/d Myosim Heavy Chain mRNAs in the Rat Slow Soleus Muscle

    Czech Academy of Sciences Publication Activity Database

    Žurmanová, Jitka; Půta, F.; Stopková, R.; Soukup, Tomáš

    2008-01-01

    Roč. 57, č. 6 (2008), s. 973-978 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA305/06/1115; GA ČR(CZ) GA304/08/0256 Grant - others:EC(XE) LSH-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : rat slow soleus muscle * myosin heavy chain isoforms * real time RT-PCR Subject RIV: ED - Physiology Impact factor: 1.653, year: 2008

  2. Levels of myosin heavy chain mRNA transcripts and content of protein isoforms in the slow soleus muscle of 7 month-old rats with altered thyroid status

    Czech Academy of Sciences Publication Activity Database

    Vadászová, Adriana; Hudecová, S.; Križanová, O.; Soukup, Tomáš

    2006-01-01

    Roč. 55, č. 2 (2006), s. 221-225 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GD305/03/H148; GA ČR(CZ) GA304/05/0327 Grant - others:VEGA(SK) 2/6078; SAV(SK) APVT-51-027404; NATO(XE) 979876; MYORES(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : myosin heavy chain * thyroid hormones status * mRNA transcripts Subject RIV: ED - Physiology Impact factor: 2.093, year: 2006

  3. Triticale (XTriticosecale W.) Heavy Metal Upptake as a Possibility of Food Chain Pollution in a Long-Term Field Experiment in Hungary

    Science.gov (United States)

    László Phd, M., ,, Dr.

    2009-04-01

    mixes and crackers due to a savory, nutty flavor. Etanol plants will pay a premium for triticale over barley since it has more starch and no hull, making alcohol production more efficient. Germany, France, China, Poland and Hungary account for nearly 90 percent of world triticale production (Donald et al. 2001). Heavy metals are dangerous because they tend to bioaccumulate in food chain. Bioaccumulation means an increase in the concentration of a chemical in a biological organism over time, compared to the chemical`s concentration in they environment. Compounds accumulate in living things any time they are taken up and stored faster han they are broken down (metabolize) or extreted. Crops have ability to heavy metal accumulation from fertilizers such as Cd, Pb, Cu, Zn etc. to a different degree (Lee et al. 2001, Scholz and Ellerbrock 2004). The main purposes of this study was to determine the triticale toxic element upptake by the soil, triticale leaf+straw and grain element concentrations on acid sandy soil in a long-term field fertilization experiment at Nyirlugos, Hungary in 1998. Material and Methods: Field experiments were carried out on an acidic sandy brown forest soil at Nyírlugos in East-Hungary from 1962 to 2005. Soil geochemical parameters were as follow: humus 0.6%, pH (H2O) 5.8, pH (KCl) 4.6, total N 32.8 mg/kg, AL (ammonium lactate soluble)- P2O5 43 mg/kg, AL-K2O 52 mg/kg. The experiments involved 32 NPKCaMg treatments in 4 replications giving a total of 128 plots. N levels were 0, 50, 100, 150 kg/ha/yr, P2O5 and K2O 0, 60, 120, 180 kg/ha/yr, CaCO3 0, 250, 500, 1000 kg/ha/yr and MgCO3 doses were 0, 140, 280 kg/ha/yr. Plot brutto size was 50 m2. Composite soil samples consisting of 25 subsamples collected at before flowering time from the ploughed layer of each plot. The so-called "mobile" fraction was extracted by ammonium-acetate+EDTA (AAc+EDTA, Lakanen and Ervio 1971) and the heavy metal determination by ICP-AES technic. Plant leaf+straw and seed

  4. Importance of Hypervariable Region 2 for Stability and Affinity of a Shark Single-Domain Antibody Specific for Ebola Virus Nucleoprotein.

    Directory of Open Access Journals (Sweden)

    George P Anderson

    Full Text Available Single-domain antibodies derived from the unique New Antigen Receptor found in sharks have numerous potential applications, ranging from diagnostic reagents to therapeutics. Shark-derived single-domain antibodies possess the same characteristic ability to refold after heat denaturation found in single-domain antibodies derived from camelid heavy-chain-only antibodies. Recently, two shark derived single-domain antibodies specific for the nucleoprotein of Ebola virus were described. Our evaluation confirmed their high affinity for the nucleoprotein, but found their melting temperatures to be low relative to most single-domain antibodies. Our first approach towards improving their stability was grafting antigen-binding regions (complementarity determining regions of one of these single-domain antibodies onto a high melting temperature shark single-domain antibody. This resulted in two variants: one that displayed excellent affinity with a low melting temperature, while the other had poor affinity but a higher melting temperature. These new proteins, however, differed in only 3 amino acids within the complementarity determining region 2 sequence. In shark single-domain antibodies, the complementarity determining region 2 is often referred to as hypervariable region 2, as this segment of the antibody domain is truncated compared to the sequence in camelid single-domain antibodies and conventional heavy chain variable domains. To elucidate which of the three amino acids or combinations thereof were responsible for the affinity and stability we made the 6 double and single point mutants that covered the intermediates between these two clones. We found a single amino acid change that achieved a 10°C higher melting temperature while maintaining sub nM affinity. This research gives insights into the impact of the shark sdAb hypervariable 2 region on both stability and affinity.

  5. Elevated Concentrations of Serum Immunoglobulin Free Light Chains in Systemic Lupus Erythematosus Patients in Relation to Disease Activity, Inflammatory Status, B Cell Activity and Epstein-Barr Virus Antibodies

    DEFF Research Database (Denmark)

    Draborg, Anette H; Lydolph, Magnus; Westergaard, Marie

    2015-01-01

    , FLCs' association with Epstein-Barr virus (EBV) antibodies was examined. METHODS: Using a nephelometric assay, κFLC and λFLC concentrations were quantified in sera from 45 SLE patients and 40 healthy controls. SLE patients with renal insufficiency were excluded in order to preclude high concentrations......OBJECTIVE: In this study, we examined the concentration of serum immunoglobulin free light chains (FLCs) in systemic lupus erythematosus (SLE) patients and investigated its association with various disease parameters in order to evaluate the role of FLCs as a potential biomarker in SLE. Furthermore...... of serum FLCs due to decreased clearance. RESULTS: Serum FLC concentrations were significantly elevated in SLE patients compared to healthy controls (pdisease activity (SLE disease activity...

  6. Rapid Isolation of a Single-Chain Antibody against the Cyanobacterial Toxin Microcystin-LR by Phage Display and Its Use in the Immunoaffinity Concentration of Microcystins from Water

    Science.gov (United States)

    McElhiney, Jacqui; Drever, Mathew; Lawton, Linda A.; Porter, Andy J.

    2002-01-01

    A naïve (unimmunized) human semisynthetic phage display library was employed to isolate recombinant antibody fragments against the cyanobacterial hepatotoxin microcystin-LR. Selected antibody scFv genes were cloned into a soluble expression vector and expressed in Escherichia coli for characterization against purified microcystin-LR by competition enzyme-linked immunosorbent assay (ELISA). The most sensitive single-chain antibody (scAb) isolated was capable of detecting microcystin-LR at levels below the World Health Organization limit in drinking water (1 μg liter−1) and cross-reacted with three other purified microcystin variants (microcystin-RR, -LW, and -LF) and the related cyanotoxin nodularin. Extracts of the cyanobacterium Microcystis aeruginosa were assayed by ELISA, and quantifications of microcystins in toxic samples showed good correlation with analysis by high-performance liquid chromatography. Immobilized scAb was also used to prepare immunoaffinity columns, which were assessed for the ability to concentrate microcystin-LR from water for subsequent analysis by high-performance liquid chromatography. Anti-microcystin-LR scAb was immobilized on columns via a hexahistidine tag, ensuring maximum exposure of antigen binding sites, and the performance of the columns was evaluated by directly applying 150 ml of distilled water spiked with 4 μg of purified microcystin-LR. The procedure was simple, and a recovery rate of 94% was achieved following elution in 1 ml of 100% methanol. Large-scale, low-cost production of anti-microcystin-LR scAb in E. coli is an exciting prospect for the development of biosensors and on-line monitoring systems for microcystins and will also facilitate a range of immunoaffinity applications for the cleanup and concentration of these toxins from environmental samples. PMID:12406716

  7. Myosins 1 and 6, myosin light chain kinase, actin and microtubules cooperate during antibody-mediated internalisation and trafficking of membrane-expressed viral antigens in feline infectious peritonitis virus infected monocytes.

    Science.gov (United States)

    Dewerchin, Hannah L; Desmarets, Lowiese M; Noppe, Ytse; Nauwynck, Hans J

    2014-02-12

    Monocytes infected with feline infectious peritonitis virus, a coronavirus, express viral proteins in their plasma membranes. Upon binding of antibodies, these proteins are quickly internalised through a new clathrin- and caveolae-independent internalisation pathway. By doing so, the infected monocytes can escape antibody-dependent cell lysis. In the present study, we investigated which kinases and cytoskeletal proteins are of importance during internalisation and subsequent intracellular transport. The experiments showed that myosin light chain kinase (MLCK) and myosin 1 are crucial for the initiation of the internalisation. With co-localisation stainings, it was found that MLCK and myosin 1 co-localise with antigens even before internalisation started. Myosin 6 co-localised with the internalising complexes during passage through the cortical actin, were it might play a role in moving or disintegrating actin filaments, to overcome the actin barrier. One minute after internalisation started, vesicles had passed the cortical actin, co-localised with microtubules and association with myosin 6 was lost. The vesicles were further transported over the microtubules and accumulated at the microtubule organising centre after 10 to 30 min. Intracellular trafficking over microtubules was mediated by MLCK, myosin 1 and a small actin tail. Since inhibiting MLCK with ML-7 was so efficient in blocking the internalisation pathway, this target can be used for the development of a new treatment for FIPV.

  8. Antigenic sites on the HN domain of botulinum neurotoxin A stimulate protective antibody responses against active toxin.

    Science.gov (United States)

    Ayyar, B Vijayalakshmi; Tajhya, Rajeev B; Beeton, Christine; Atassi, M Zouhair

    2015-10-28

    Botulinum neurotoxins (BoNTs) are the most toxic substances known. BoNT intoxicates cells in a highly programmed fashion initiated by binding to the cell surface, internalization and enzymatic cleavage of substrate, thus, inhibiting synaptic exocytosis. Over the past two decades, immunological significance of BoNT/A C-terminal heavy chain (HC) and light chain (LC) domains were investigated extensively leading to important findings. In the current work, we explored the significance of BoNT/A heavy chain N-terminal (HN) region as a vaccine candidate. Mice were immunized with recombinant HN519-845 generating antibodies (Abs) that were found to be protective against lethal dose of BoNT/A. Immuno-dominant regions of HN519-845 were identified and individually investigated for antibody response along with synthetic peptides within those regions, using in vivo protection assays against BoNT/A. Results were confirmed by patch-clamp analysis where anti-HN antibodies were studied for the ability to block toxin-induced channel formation. This data strongly indicated that HN519-593 is an important region in generating protective antibodies and should be valuable in a vaccine design. These results are the first to describe and dissect the protective activity of the BoNT/A HN domain.

  9. Transfer of heavy metals in the food chain earthworm Black-tailed godwit (Limosa limosa): Comparison of a polluted and a reference site in The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Roodbergen, Maja [Department of Ecology and Environment, ALTERRA, PO Box 47, 6700 AA, Wageningen (Netherlands); Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Haren (Netherlands)], E-mail: maja.roodbergen@sovon.nl; Klok, Chris; Hout, Annemariet van der [Department of Ecology and Environment, ALTERRA, PO Box 47, 6700 AA, Wageningen (Netherlands)

    2008-12-01

    The Black-tailed godwit (Limosa limosa) is a migratory wader that favours wet meadows for breeding. The species has a Red List status in The Netherlands, as it strongly declined in numbers since the 1960s. Intensification of agriculture and land use change resulting in habitat loss are considered major causes of this decline. In some areas the breeding habitat is contaminated with heavy metals. Adult godwits mainly feed on earthworms in the breeding season, which are known to accumulate heavy metals from the soil. In this paper we investigate the transfer of heavy metals from the soil to the Black-tailed godwit, which may have an additive negative effect on the viability of local populations. We measured heavy metal concentrations in soil, earthworms, and godwit eggs and feathers at a polluted and a reference site. The results suggest that Lead, Mercury and Cadmium are transferred from the soil to godwits even though the species spends only a few months in the breeding area during the year.

  10. Transfer of heavy metals in the food chain earthworm Black-tailed godwit (Limosa limosa): Comparison of a polluted and a reference site in The Netherlands

    International Nuclear Information System (INIS)

    Roodbergen, Maja; Klok, Chris; Hout, Annemariet van der

    2008-01-01

    The Black-tailed godwit (Limosa limosa) is a migratory wader that favours wet meadows for breeding. The species has a Red List status in The Netherlands, as it strongly declined in numbers since the 1960s. Intensification of agriculture and land use change resulting in habitat loss are considered major causes of this decline. In some areas the breeding habitat is contaminated with heavy metals. Adult godwits mainly feed on earthworms in the breeding season, which are known to accumulate heavy metals from the soil. In this paper we investigate the transfer of heavy metals from the soil to the Black-tailed godwit, which may have an additive negative effect on the viability of local populations. We measured heavy metal concentrations in soil, earthworms, and godwit eggs and feathers at a polluted and a reference site. The results suggest that Lead, Mercury and Cadmium are transferred from the soil to godwits even though the species spends only a few months in the breeding area during the year

  11. Purification of polyclonal IgG specific for Camelid’s antibodies and their recombinant nanobodies

    Directory of Open Access Journals (Sweden)

    Haddad Muhammad

    2016-01-01

    Full Text Available Camelid’ s heavy-chain antibody (HCAb consists of only two heavy chains and lacks the two light chains together with the CH1 domain usually found in conventional immunoglobulins. A recombinant single antigen-binding entity, named VHH (or Nanobody® was generated by reengineering the variable domains from HCAb. This study focuses on the detection of camelid´s immunoglobulins as well as their derivative nanobodies using a universal anti-camel antibody produced in rabbit (rIgG. Starting from a crude rabbit serum, a standard stock of rIgG (1 mg/ml was prepared after purification by affinity chromatography using protein-A column. As expected, rIgG was able to detect camel antibodies in ELISA and immunoblotting, and its reactivity was equal against all different camel IgG subclasses, which were purified from serum by differential affinity chromatography on protein-G and -A. Interestingly, rIgG also recognized nanobodies since they were originally part of camel HCAbs, providing an alternative method to detect the corpus of these recombinant proteins rather than targeting their artificial tags. These data suggest that the anti-camel rIgG described here could be efficiently applied at different stages of nanobody technology, including the quantitation of the issued nanobodies and their detection when bound to target antigens.

  12. Affinity improvement of a therapeutic antibody by structure-based computational design: generation of electrostatic interactions in the transition state stabilizes the antibody-antigen complex.

    Directory of Open Access Journals (Sweden)

    Masato Kiyoshi

    Full Text Available The optimization of antibodies is a desirable goal towards the development of better therapeutic strategies. The antibody 11K2 was previously developed as a therapeutic tool for inflammatory diseases, and displays very high affinity (4.6 pM for its antigen the chemokine MCP-1 (monocyte chemo-attractant protein-1. We have employed a virtual library of mutations of 11K2 to identify antibody variants of potentially higher affinity, and to establish benchmarks in the engineering of a mature therapeutic antibody. The most promising candidates identified in the virtual screening were examined by surface plasmon resonance to validate the computational predictions, and to characterize their binding affinity and key thermodynamic properties in detail. Only mutations in the light-chain of the antibody are effective at enhancing its affinity for the antigen in vitro, suggesting that the interaction surface of the heavy-chain (dominated by the hot-spot residue Phe101 is not amenable to optimization. The single-mutation with the highest affinity is L-N31R (4.6-fold higher affinity than wild-type antibody. Importantly, all the single-mutations showing increase affinity incorporate a charged residue (Arg, Asp, or Glu. The characterization of the relevant thermodynamic parameters clarifies the energetic mechanism. Essentially, the formation of new electrostatic interactions early in the binding reaction coordinate (transition state or earlier benefits the durability of the antibody-antigen complex. The combination of in silico calculations and thermodynamic analysis is an effective strategy to improve the affinity of a matured therapeutic antibody.

  13. Elevated Concentrations of Serum Immunoglobulin Free Light Chains in Systemic Lupus Erythematosus Patients in Relation to Disease Activity, Inflammatory Status, B Cell Activity and Epstein-Barr Virus Antibodies.

    Directory of Open Access Journals (Sweden)

    Anette H Draborg

    Full Text Available In this study, we examined the concentration of serum immunoglobulin free light chains (FLCs in systemic lupus erythematosus (SLE patients and investigated its association with various disease parameters in order to evaluate the role of FLCs as a potential biomarker in SLE. Furthermore, FLCs' association with Epstein-Barr virus (EBV antibodies was examined.Using a nephelometric assay, κFLC and λFLC concentrations were quantified in sera from 45 SLE patients and 40 healthy controls. SLE patients with renal insufficiency were excluded in order to preclude high concentrations of serum FLCs due to decreased clearance.Serum FLC concentrations were significantly elevated in SLE patients compared to healthy controls (p<0.0001 also after adjusting for Ig levels (p<0.0001. The concentration of serum FLCs correlated with a global disease activity (SLE disease activity index (SLEDAI score of the SLE patients (r = 0.399, p = 0.007. Furthermore, concentrations of FLCs correlated with titers of dsDNA antibodies (r = 0.383, p = 0.009, and FLC levels and SLEDAI scores correlated in the anti-dsDNA-positive SLE patients, but not in anti-dsDNA-negative SLE patients. Total immunoglobulin (IgG and IgA concentrations correlated with FLC concentrations and elevated FLC levels were additionally shown to associate with the inflammatory marker C-reactive protein and also with complement consumption determined by low C4 in SLE patients. Collectively, results indicated that elevated serum FLCs reflects increased B cell activity in relation to inflammation. SLE patients had an increased seropositivity of EBV-directed antibodies that did not associate with elevated FLC concentrations. An explanation for this could be that serum FLC concentrations reflect the current EBV activity (reactivation whereas EBV-directed antibodies reflect the extent of previous infection/reactivations.SLE patients have elevated concentrations of serum FLCs that correlate with global disease

  14. Human placenta: relative content of antibodies of different classes and subclasses (IgG1-IgG4) containing lambda- and kappa-light chains and chimeric lambda-kappa-immunoglobulins.

    Science.gov (United States)

    Lekchnov, Evgenii A; Sedykh, Sergey E; Dmitrenok, Pavel S; Buneva, Valentina N; Nevinsky, Georgy A

    2015-06-01

    The specific organ placenta is much more than a filter: it is an organ that protects, feeds and regulates the growth of the embryo. Affinity chromatography, ELISA, SDS-PAGE and matrix-assisted laser desorption ionization mass spectrometry were used. Using 10 intact human placentas deprived of blood, a quantitative analysis of average relative content [% of total immunoglobulins (Igs)] was carried out for the first time: (92.7), IgA (2.4), IgM (2.5), kappa-antibodies (51.4), lambda-antibodies (48.6), IgG1 (47.0), IgG2 (39.5), IgG3 (8.8) and IgG4 (4.3). It was shown for the first time that placenta contains sIgA (2.5%). In the classic paradigm, Igs represent products of clonal B-cell populations, each producing antibodies recognizing a single antigen. There is a common belief that IgGs in mammalian biological fluids are monovalent molecules having stable structures and two identical antigen-binding sites. However, similarly to human milk Igs, placenta antibodies undergo extensive half-molecule exchange and the IgG pool consists of 43.5 ± 15.0% kappa-kappa-IgGs and 41.6 ± 17.0% lambda-lambda-IgGs, while 15.0 ± 4.0% of the IgGs contained both kappa- and lambda-light chains. Kappa-kappa-IgGs and lambda-lambda-IgGs contained, respectively (%): IgG1 (47.7 and 34.4), IgG2 (36.3 and 44.5), IgG3 (7.4 and 11.8) and IgG4 (7.5 and 9.1), while chimeric kappa-lambda-IgGs consisted of (%): 43.5 IgG1, 41.0 IgG2, 5.6 IgG3 and 7.9 IgG4. Our data are indicative of the possibility of half-molecule exchange between placenta IgGs of various subclasses, raised against different antigens, which explains a very well-known polyspecificity and cross-reactivity of different human IgGs. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Humanization and characterization of an anti-ricin neutralization monoclonal antibody.

    Directory of Open Access Journals (Sweden)

    Wei-Gang Hu

    Full Text Available Ricin is regarded as a high terrorist risk for the public due to its high toxicity and ease of production. Currently, there is no therapeutic or vaccine available against ricin. D9, a murine monoclonal antibody developed previously in our laboratory, can strongly neutralize ricin and is therefore a good candidate for humanization. Humanization of D9 variable regions was achieved by a complementarity-determining region grafting approach. The humanized D9 (hD9 variable regions were further grafted onto human heavy and light chain constant regions to assemble the complete antibody gene. A foot-and-mouth-disease virus-derived 2A self-processing sequence was introduced between heavy and light chain DNA sequences to cleave the recombinant protein into a functional full-length antibody molecule from a single open reading frame driven by a single promoter in an adenoviral vector. After expression in mammalian cells and purification, the hD9 was demonstrated to have equimolar expression of the full-length antibody heavy and light chains. More importantly, the hD9 exhibited high affinity to ricin with K(D of 1.63 nM, comparable to its parental murine D9 (2.55 nM. In a mouse model, intraperitoneal (i.p. administration of hD9, at a low dose of 5 µg per mouse, 4 hours after the i.p. challenge with 5×LD50 ricin was found to rescue 100% of the mice. In addition, administered 6 hours post-challenge, hD9 could still rescue 50% of the mice. The hD9 has the potential to be used for prophylactic or therapeutic purposes against ricin poisoning.

  16. Construction and expression of a recombinant antibody-targeted plasminogen activator

    International Nuclear Information System (INIS)

    Schnee, J.M.; Runge, M.S.; Matsueda, G.A.; Hudson, N.W.; Seidman, J.G.; Haber, E.; Quertermous, T.

    1987-01-01

    Covalent linkage of tissue-type plasminogen activator (t-PA) to a monoclonal antibody specific for the fibrin β chain (anti-fibrin 59D8) results in a thrombolytic agent that is more specific and more potent that t-PA alone. To provide a ready source of this hybrid molecule and to allow tailoring of the active moieties for optimal activity, the authors have engineered a recombinant version of the 59D8-t-PA conjugate. The rearranged 59D8 heavy chain gene was cloned and combined in the expression vector pSV2gpt with sequence coding for a portion of the γ2b constant region and the catalytic β chain of t-PA. This construct was transfected into heavy chain loss variant cells derived form the 59D8 hybridoma. Recombinant protein was purified by affinity chromatography and analyzed with electrophoretic transfer blots and radioimmunoassay. These revealed a 65-kDa heavy chain-t-PA fusion protein that is secreted in association with the 59D8 light chain in the form of a 170-kDa disulfide-linked dimer. Chromogenic substrate assays showed the fusion protein to have 70% of the peptidolytic activity of native t-PA and to activate plasminogen as efficiently as t-PA. IN a competitive binding assay, reconstituted antibody was shown to have a binding profile similar to that of native 59D8. Thus, by recombinant techniques, they have produced a hybrid protein capable of high affinity fibrin binding and plasminogen activation

  17. A fully automated primary screening system for the discovery of therapeutic antibodies directly from B cells.

    Science.gov (United States)

    Tickle, Simon; Howells, Louise; O'Dowd, Victoria; Starkie, Dale; Whale, Kevin; Saunders, Mark; Lee, David; Lightwood, Daniel

    2015-04-01

    For a therapeutic antibody to succeed, it must meet a range of potency, stability, and specificity criteria. Many of these characteristics are conferred by the amino acid sequence of the heavy and light chain variable regions and, for this reason, can be screened for during antibody selection. However, it is important to consider that antibodies satisfying all these criteria may be of low frequency in an immunized animal; for this reason, it is essential to have a mechanism that allows for efficient sampling of the immune repertoire. UCB's core antibody discovery platform combines high-throughput B cell culture screening and the identification and isolation of single, antigen-specific IgG-secreting B cells through a proprietary technique called the "fluorescent foci" method. Using state-of-the-art automation to facilitate primary screening, extremely efficient interrogation of the natural antibody repertoire is made possible; more than 1 billion immune B cells can now be screened to provide a useful starting point from which to identify the rare therapeutic antibody. This article will describe the design, construction, and commissioning of a bespoke automated screening platform and two examples of how it was used to screen for antibodies against two targets. © 2014 Society for Laboratory Automation and Screening.

  18. A Monoclonal Antibody Based Capture ELISA for Botulinum Neurotoxin Serotype B: Toxin Detection in Food

    Directory of Open Access Journals (Sweden)

    Larry H. Stanker

    2013-11-01

    Full Text Available Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT, produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A–H have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We report here a group of serotype B specific monoclonal antibodies (mAbs capable of binding toxin under physiological conditions. Thus, they serve as capture antibodies for a sandwich (capture ELISA. The antibodies were generated using recombinant peptide fragments corresponding to the receptor-binding domain of the toxin heavy chain as immunogen. Their binding properties suggest that they bind a complex epitope with dissociation constants (KD’s for individual antibodies ranging from 10 to 48 × 10−11 M. Assay performance for all possible combinations of capture-detector antibody pairs was evaluated and the antibody pair resulting in the lowest level of detection (L.O.D., ~20 pg/mL was determined. Toxin was detected in spiked dairy samples with good recoveries at concentrations as low as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the sandwich ELISA described here uses mAb for both the capture and detector antibodies (binding different epitopes on the toxin molecule and readily detects toxin in those food samples tested.

  19. A monoclonal antibody based capture ELISA for botulinum neurotoxin serotype B: toxin detection in food.

    Science.gov (United States)

    Stanker, Larry H; Scotcher, Miles C; Cheng, Luisa; Ching, Kathryn; McGarvey, Jeffery; Hodge, David; Hnasko, Robert

    2013-11-18

    Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT), produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A-H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We report here a group of serotype B specific monoclonal antibodies (mAbs) capable of binding toxin under physiological conditions. Thus, they serve as capture antibodies for a sandwich (capture) ELISA. The antibodies were generated using recombinant peptide fragments corresponding to the receptor-binding domain of the toxin heavy chain as immunogen. Their binding properties suggest that they bind a complex epitope with dissociation constants (KD's) for individual antibodies ranging from 10 to 48 × 10-11 M. Assay performance for all possible combinations of capture-detector antibody pairs was evaluated and the antibody pair resulting in the lowest level of detection (L.O.D.), ~20 pg/mL was determined. Toxin was detected in spiked dairy samples with good recoveries at concentrations as low as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the sandwich ELISA described here uses mAb for both the capture and detector antibodies (binding different epitopes on the toxin molecule) and readily detects toxin in those food samples tested.

  20. Detection of rabies in camel, goat and cattle in Sudan using Fluorescent antibody test (FAT and hemi nested Polymerase Chain Reaction (hnRT-PCR

    Directory of Open Access Journals (Sweden)

    Baraa Abdalaziz Ahmed

    2016-09-01

    Full Text Available Objective: The objective of this study was to identify rabies virus in camels and other animals in Sudan. Materials and methods: Four camel samples were collected from Garraht Elzawia, Kab-kabia and North Darfur areas in Sudan. The samples were collected based on clinical signs. In addition, two camel samples were obtained from Khartoum and Tambool, one goat sample was collected from El-Fashir, and one cattle sample was obtained from Atbara. The samples were transported to the Veterinary Research Institute (VRI at Khartoum, Sudan for further studies. The samples were subjected for nested and hemi nested RT-PCR (hnRT-PCR along with the gold standard Fluorescent antibody test (FAT to diagnose rabies. Results: Out of eight samples, seven were found to be positive by both FAT and RT-PCR methods. The remaining one sample was positive by FAT but negative by hnRT-PCR indicating the suitablity of hnRT-PCR along with FAT for accurate diagnosis of rabies in animals. Conclusion: The study concluded that FAT and RT-PCR are useful tools for research and diagnosis of rabies. [J Adv Vet Anim Res 2016; 3(3.000: 274-277

  1. Protein crystallization with microseed matrix screening: application to human germline antibody Fabs

    International Nuclear Information System (INIS)

    Obmolova, Galina; Malia, Thomas J.; Teplyakov, Alexey; Sweet, Raymond W.; Gilliland, Gary L.

    2014-01-01

    The power of microseed matrix screening is demonstrated in the crystallization of a panel of antibody Fab fragments. The crystallization of 16 human antibody Fab fragments constructed from all pairs of four different heavy chains and four different light chains was enabled by employing microseed matrix screening (MMS). In initial screening, diffraction-quality crystals were obtained for only three Fabs, while many Fabs produced hits that required optimization. Application of MMS, using the initial screens and/or refinement screens, resulted in diffraction-quality crystals of these Fabs. Five Fabs that failed to give hits in the initial screen were crystallized by cross-seeding MMS followed by MMS optimization. The crystallization protocols and strategies that resulted in structure determination of all 16 Fabs are presented. These results illustrate the power of MMS and provide a basis for developing future strategies for macromolecular crystallization

  2. Flexibility of the myosin heavy chain: direct evidence that the region containing SH/sub 1/ and SH/sub 2/ can move 10 /Angstrom/ under the influence of nucleotide binding

    Energy Technology Data Exchange (ETDEWEB)

    Huston, E.E.; Grammer, J.C.; Yount, R.G.

    1988-12-13

    Previous experiments demonstrated that two thiols of skeletal myosin subfragment 1 (SF/sub 1/) could be oxidized to a disulfide bond by treatment with a 2-fold excess of 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) in the presence of MgADP. The resulting characteristic changes in the ATPase activities of SF/sub 1/ and the fact that MgADP was stably trapped at the active site, suggested that the two thiols cross-linked were SH/sub 1/ (Cys-707) and SH/sub 2/ (Cys-697) from the myosin heavy chain. To verify this suggestion, SF/sub 1/, after DTNB treatment as above, was treated with an excess of N-ethylmaleimide to block all accessible thiols. The single protein disulfide produced by DTNB oxidation was reduced with dithioerythritol and the modified SF/sub 1/ internally cross-linked with equimolar (/sup 14/C)p-phenylenedimaleimide (pPDM) in the presence of MgADP. After extensive trypsinization, the major /sup 14/C-labeled peptide was isolated, characterized, and shown to be Cys-Asn-Gly-Val-Leu-Gly-Ile-Arg-Ile-Cys-Arg, in which the two cysteines were cross-linked by pPDM. This peptide is known to contain SH/sub 2/ and SH/sub 1/ in this order and to come from residues 697-708 in the rabbit skeletal myosin heavy chain. Parallel experiments with (/sup 14/C)pPDM and unmodified SF/sub 1/ similar to those above gave an identical SH/sub 1/, SH/sub 2/ tryptic peptide, verifying earlier labeling results. These combined results demonstrate that SH/sub 1/ and SH/sub 2/ cross-linked by pPDM (12-13 /Angstrom/, S to S) or by oxidation with DTNB (2 /Angstrom/, S to S) can move a minimum of 10 /Angstrom/ under the influence of nucleotide binding. Because these residues are separated by only nine amino acids in the primary sequence, this small section of the heavy chain must possess extraordinary flexibility.

  3. Antibody biotechnology

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... Another milestone in the history of antibodies was the work of Porter and Edelman ... transgenic animals (Lonberg et al., 1994; Green et al.,. 1994) or .... create and to screen human recombinant antibodies libraries, that is ...

  4. Antithyroid microsomal antibody

    Science.gov (United States)

    Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb ... Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also been linked with an increased risk ...

  5. Generation of single domain antibody fragments derived from camelids and generation of manifold constructs.

    Science.gov (United States)

    Vincke, Cécile; Gutiérrez, Carlos; Wernery, Ulrich; Devoogdt, Nick; Hassanzadeh-Ghassabeh, Gholamreza; Muyldermans, Serge

    2012-01-01

    Immunizing a camelid (camels and llamas) with soluble, properly folded proteins raises an affinity-matured immune response in the unique camelid heavy-chain only antibodies (HCAbs). The peripheral blood lymphocytes of the immunized animal are used to clone the antigen-binding antibody fragment from the HCAbs in a phage display vector. A representative aliquot of the library of these antigen-binding fragments is used to retrieve single domain antigen-specific binders by successive rounds of panning. These single domain antibody fragments are cloned in tandem to generate manifold constructs (bivalent, biparatopic or bispecific constructs) to increase their functional affinity, to increase specificity, or to connect two independent antigen molecules.

  6. B cell and antibody repertoire development in rabbits: the requirement of gut-associated lymphoid tissues.

    Science.gov (United States)

    Mage, Rose G; Lanning, Dennis; Knight, Katherine L

    2006-01-01

    The antibody repertoire of rabbits has interested immunologists for decades, in part because of the ease with which large quantities of high affinity antibodies can be obtained in serum, and in part because of the presence of genetic variants, allotypes, within V(H), C(H) and C(L) regions. Studies of these allotypes led to the initial descriptions of allelic exclusion, and neonatal suppression of serum Ig production (allotype suppression), and were instrumental in demonstrating that V and C regions are encoded by separate genes and are usually expressed in cis. The immune system of rabbit continues to be of interest primarily because of the use of both gene conversion and somatic hypermutation to diversify rearranged heavy and light chain genes and the role that gut-associated lymphoid tissues (GALT) and intestinal flora play in developing the primary (preimmune) antibody repertoire.

  7. Discovery of a Chemical Modification by Citric Acid in a Recombinant Monoclonal Antibody

    Science.gov (United States)

    2015-01-01

    Recombinant therapeutic monoclonal antibodies exhibit a high degree of heterogeneity that can arise from various post-translational modifications. The formulation for a protein product is to maintain a specific pH and to minimize further modifications. Generally Recognized as Safe (GRAS), citric acid is commonly used for formulation to maintain a pH at a range between 3 and 6 and is generally considered chemically inert. However, as we reported herein, citric acid covalently modified a recombinant monoclonal antibody (IgG1) in a phosphate/citrate-buffered formulation at pH 5.2 and led to the formation of so-called “acidic species” that showed mass increases of 174 and 156 Da, respectively. Peptide mapping revealed that the modification occurred at the N-terminus of the light chain. Three additional antibodies also showed the same modification but displayed different susceptibilities of the N-termini of the light chain, heavy chain, or both. Thus, ostensibly unreactive excipients under certain conditions may increase heterogeneity and acidic species in formulated recombinant monoclonal antibodies. By analogy, other molecules (e.g., succinic acid) with two or more carboxylic acid groups and capable of forming an anhydride may exhibit similar reactivities. Altogether, our findings again reminded us that it is prudent to consider formulations as a potential source for chemical modifications and product heterogeneity. PMID:25136741

  8. Site-specific proteolytic degradation of IgG monoclonal antibodies expressed in tobacco plants.

    Science.gov (United States)

    Hehle, Verena K; Lombardi, Raffaele; van Dolleweerd, Craig J; Paul, Mathew J; Di Micco, Patrizio; Morea, Veronica; Benvenuto, Eugenio; Donini, Marcello; Ma, Julian K-C

    2015-02-01

    Plants are promising hosts for the production of monoclonal antibodies (mAbs). However, proteolytic degradation of antibodies produced both in stable transgenic plants and using transient expression systems is still a major issue for efficient high-yield recombinant protein accumulation. In this work, we have performed a detailed study of the degradation profiles of two human IgG1 mAbs produced in plants: an anti-HIV mAb 2G12 and a tumour-targeting mAb H10. Even though they use different light chains (κ and λ, respectively), the fragmentation pattern of both antibodies was similar. The majority of Ig fragments result from proteolytic degradation, but there are only a limited number of plant proteolytic cleavage events in the immunoglobulin light and heavy chains. All of the cleavage sites identified were in the proximity of interdomain regions and occurred at each interdomain site, with the exception of the VL /CL interface in mAb H10 λ light chain. Cleavage site sequences were analysed, and residue patterns characteristic of proteolytic enzymes substrates were identified. The results of this work help to define common degradation events in plant-produced mAbs and raise the possibility of predicting antibody degradation patterns 'a priori' and designing novel stabilization strategies by site-specific mutagenesis. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  9. Complete assignment of the methionyl carbonyl carbon resonance in switch variant anti-dansyl antibodies labeled with (1- sup 13 C)methionine

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Koichi; Matsunaga, C.; Igarashi, Takako; Kim, Hahyung; Odaka, Asano; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo, Hongo (Japan))

    1991-01-01

    A {sup 13}C NMR study is reported of switch variant anti-dansyl antibodies developed by Dangl et al. who had used the fluorescence-activated cell sorter to select and clone these variants. These switch variant antibodies possess the identical V{sub H}, V{sub L}, and C{sub L} domains in conjunction with different heavy chain constant regions. In the present study, switch variant antibodies of IgG1, IgG2a, and IgG2b subclasses were used along with a short-chain IgG2a antibody, in which the entire C{sub H}1 domain is deleted. The switch variant antibodies were specifically labeled with (1-{sup 13}C)methionine by growing hybridoma cells in serum-free medium. Assignments of all the methionyl carbonyl carbon resonances have been completed by using the intact antibodies along with their fragments and recombined proteins in which either heavy or light chain is labeled. A double labeling method has played a crucial role in the process of the spectral assignments. The strategy used for the assignments has been described in detail. In incorporating {sup 15}N-labeled amino acids into the antibodies for the double labeling, isotope dilution caused a serious problem except in the cases of ({alpha}-{sup 15}N)lysine and ({sup 15}N)threonine, both of which cannot become the substrate of transaminases. It was found that {beta}-chloro-L-alanine is most effective in suppressing the isotope scrambling. So far, spectral assignments by the double labeling method have been possible with {sup 15}N-labeled Ala, His, Ile, Lys, Met, Ser, Thr, Tyr, and Val. On the basis of the results of the present {sup 13}C study, possible use of the assigned carbonyl carbon resonances for the elucidation of the structure-function relationship in the antibody system has been briefly discussed.

  10. Complete assignment of the methionyl carbonyl carbon resonance in switch variant anti-dansyl antibodies labeled with [1-13C]methionine

    International Nuclear Information System (INIS)

    Kato, Koichi; Matsunaga, C.; Igarashi, Takako; Kim, Hahyung; Odaka, Asano; Shimada, Ichio; Arata, Yoji

    1991-01-01

    A 13 C NMR study is reported of switch variant anti-dansyl antibodies developed by Dangl et al. who had used the fluorescence-activated cell sorter to select and clone these variants. These switch variant antibodies possess the identical V H , V L , and C L domains in conjunction with different heavy chain constant regions. In the present study, switch variant antibodies of IgG1, IgG2a, and IgG2b subclasses were used along with a short-chain IgG2a antibody, in which the entire C H 1 domain is deleted. The switch variant antibodies were specifically labeled with [1- 13 C]methionine by growing hybridoma cells in serum-free medium. Assignments of all the methionyl carbonyl carbon resonances have been completed by using the intact antibodies along with their fragments and recombined proteins in which either heavy or light chain is labeled. A double labeling method has played a crucial role in the process of the spectral assignments. The strategy used for the assignments has been described in detail. In incorporating 15 N-labeled amino acids into the antibodies for the double labeling, isotope dilution caused a serious problem except in the cases of [α- 15 N]lysine and [ 15 N]threonine, both of which cannot become the substrate of transaminases. It was found that β-chloro-L-alanine is most effective in suppressing the isotope scrambling. So far, spectral assignments by the double labeling method have been possible with 15 N-labeled Ala, His, Ile, Lys, Met, Ser, Thr, Tyr, and Val. On the basis of the results of the present 13 C study, possible use of the assigned carbonyl carbon resonances for the elucidation of the structure-function relationship in the antibody system has been briefly discussed

  11. Thyroid Antibodies

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  12. Legomedicine-A Versatile Chemo-Enzymatic Approach for the Preparation of Targeted Dual-Labeled Llama Antibody-Nanoparticle Conjugates.

    Science.gov (United States)

    van Lith, Sanne A M; van Duijnhoven, Sander M J; Navis, Anna C; Leenders, William P J; Dolk, Edward; Wennink, Jos W H; van Nostrum, Cornelus F; van Hest, Jan C M

    2017-02-15

    Conjugation of llama single domain antibody fragments (Variable Heavy chain domains of Heavy chain antibodies, VHHs) to diagnostic or therapeutic nanoparticles, peptides, proteins, or drugs offers many opportunities for optimized targeted cancer treatment. Currently, mostly nonspecific conjugation strategies or genetic fusions are used that may compromise VHH functionality. In this paper we present a versatile modular approach for bioorthogonal VHH modification and conjugation. First, sortase A mediated transPEGylation is used for introduction of a chemical click moiety. The resulting clickable VHHs are then used for conjugation to other groups employing the Cu + -independent strain-promoted alkyne-azide cycloadition (SPAAC) reaction. Using this approach, tail-to-tail bispecific VHHs and VHH-targeted nanoparticles are generated without affecting VHH functionality. Furthermore, this approach allows the bioconjugation of multiple moieties to VHHs for simple and convenient production of VHH-based theranostics.

  13. Engineered antibodies for monitoring of polynuclear aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Karu, A.E.; Li, Q.X.; Roberts, V.A.

    1998-01-01

    'The long-term goal of this project is to develop antibodies and antibody-based methods for detection and recovery of polynuclear aromatic hydrocarbons (PAHs) and PAH adducts that are potential biomarkers in environmental and biological samples. The inherent cross-reactivity will be exploited by pattern recognition methods. Dr. Karu''s laboratory uses new haptens representing key PAHs to derive recombinant Fab (rFab) and single-chain Fv (scFv) antibodies from hybridoma lines and combinatorial phage display libraries. Computational models of the haptens and combining sites made by Dr. Roberts''s group are used to guide antibody engineering by mutagenesis. Dr. Li''s laboratory develops enzyme immunoassays (EIAs), sensors, and immunoaffinity methods that make use of the novel haptens and antibodies for practical analytical applications in support of DOE''s mission. This report summarizes work completed in one and one-half years of a 3-year project, with close collaboration between the three research groups. Dr. Alexander Karu''s laboratory: the authors proceeded with the two strategies described in the original proposal. Site-directed mutagenesis was used to correct differences in the rFab N-terminal amino acids that were introduced by the degenerate PCR primers used for gene amplification. The binding constants of the rFabs with the corrected sequences will be compared with those of the parent MAbs, and should be very similar. The 4D5 and 10C10 heavy and light chain sequences are being moved to the pCOMB3H phagemid vector to facilitate selection of new engineered mutants.'

  14. In vitro studies of immunoglobulin heavy-chain binding protein (BiP, GRP78). Interactions of BiP with newly synthesized proteins and adenine nucleotides

    International Nuclear Information System (INIS)

    Kassenbrock, C.K.

    1988-01-01

    Here we examine the interaction of BiP with newly synthesized polypeptides in an in vitro protein translations-translocation system. We find that BiP forms tight complexes with nonglycosylated yeast invertase and incorrectly disulfide-bonded prolactin but not with glycosylated invertase or correctly disulfide-bonded prolactin. Moreover, BiP associates detectably only with completed chains of prolactin, not with chains undergoing synthesis. We conclude that BiP recognizes and binds with high affinity to aberrantly folded or aberrantly glycosylated polypeptides in vitro, but not to all nascent chains as they are folding. BiP also binds APT and can be purified by APT affinity chromatography. We show that submicromolar levels of ATP or ADP decrease the rate of absorption of 125 I-BiP to nitrocellulose filters coated with protein or nonionic detergents. ATP and ADP also protect portions of BiP from proteolytic degradation. In contrast, micromolar levels of AMP increase the rate of adsorption and the rate of proteolytic degradation of BiP. We also show that an ATPase activity co-purifies with BiP, but its slow turnover number suggests a regulatory, rather than a functional role. The BiP-associated ATPase shares several properties with the related cytoplasmic protein, HSC70/clathrin uncoating ATPase

  15. Development and evaluation of single domain antibodies for vaccinia and the L1 antigen.

    Directory of Open Access Journals (Sweden)

    Scott A Walper

    Full Text Available There is ongoing interest to develop high affinity, thermal stable recognition elements to replace conventional antibodies in biothreat detection assays. As part of this effort, single domain antibodies that target vaccinia virus were developed. Two llamas were immunized with killed viral particles followed by boosts with the recombinant membrane protein, L1, to stimulate the immune response for envelope and membrane proteins of the virus. The variable domains of the induced heavy chain antibodies were selected from M13 phage display libraries developed from isolated RNA. Selection via biopanning on the L1 antigen produced single domain antibodies that were specific and had affinities ranging from 4×10(-9 M to 7.0×10(-10 M, as determined by surface plasmon resonance. Several showed good ability to refold after heat denaturation. These L1-binding single domain antibodies, however, failed to recognize the killed vaccinia antigen. Useful vaccinia binding single domain antibodies were isolated by a second selection using the killed virus as the target. The virus binding single domain antibodies were incorporated in sandwich assays as both capture and tracer using the MAGPIX system yielding limits of detection down to 4×10(5 pfu/ml, a four-fold improvement over the limit obtained using conventional antibodies. This work demonstrates the development of anti-vaccinia single domain antibodies and their incorporation into sandwich assays for viral detection. It also highlights the properties of high affinity and thermal stability that are hallmarks of single domain antibodies.

  16. Isolation of a human anti-epidermal growth factor receptor Fab antibody, EG-19-11, with subnanomolar affinity from naïve immunoglobulin repertoires using a hierarchical antibody library system.

    Science.gov (United States)

    Hur, Byung-ung; Yoon, Jae-bong; Liu, Li-Kun; Cha, Sang-hoon

    2010-11-30

    Specific antibodies that possess a subnanomolar affinity are very difficult to obtain from human naïve immunoglobulin repertoires without the use of lengthy affinity optimization procedures. Here, we designed a hierarchical phage-displayed antibody library system to generate an enormous diversity of combinatorial Fab fragments (6×10(17)) and attempted to isolate high-affinity Fabs against the human epidermal growth factor receptor (EGFR). A primary antibody library, designated HuDVFab-8L, comprising 4.5×10(9) human naïve heavy chains and eight unspecified human naïve light chains was selected against the EGFR-Fc protein by biopanning, and four anti-EGFR Fab clones were isolated. Because one of the Fab clones, denoted EG-L2-11, recognized a native EGFR expressed on A431 cells, the heavy chain of the Fab was shuffled with a human naïve light chain repertoire with a diversity of 1.4×10(8) and selected a second time against the EGFR-Fc protein again. One EG-L2-11 variant, denoted EG-19-11, recognized an EGFR epitope that was almost the same as that bound by cetuximab and had a K(D) of approximately 540 pM for soluble EGFR, which is about 7-fold higher than that of the FabC225 derived from cetuximab. This variant was also internalized by A431 cells, likely via receptor-mediated endocytosis, and it efficiently inhibited EGF-mediated tyrosine phosphorylation of the EGFR. These results demonstrate that the use of our hierarchical antibody library system is advantageous in generating fully human antibodies especially with a therapeutic purpose. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Altered phenotypic expression of immunoglobulin heavy-chain variable-region (VH) genes in Alicia rabbits probably reflects a small deletion in the VH genes closest to the joining region.

    Science.gov (United States)

    Allegrucci, M; Newman, B A; Young-Cooper, G O; Alexander, C B; Meier, D; Kelus, A S; Mage, R G

    1990-07-01

    Rabbits of the Alicia strain have a mutation (ali) that segregates with the immunoglobulin heavy-chain (lgh) locus and has a cis effect upon the expression of heavy-chain variable-region (VH) genes encoding the a2 allotype. In heterozygous a1/ali or a3/ali rabbits, serum immunoglobulins are almost entirely the products of the normal a1 or a3 allele and only traces of a2 immunoglobulin are detectable. Adult homozygous ali/ali rabbits likewise have normal immunoglobulin levels resulting from increased production of a-negative immunoglobulins and some residual ability to produce the a2 allotype. By contrast, the majority of the immunoglobulins of wild-type a2 rabbits are a2-positive and only a small percentage are a-negative. Genomic DNAs from homozygous mutant and wild-type animals were indistinguishable by Southern analyses using a variety of restriction enzyme digests and lgh probes. However, when digests with infrequently cutting enzymes were analyzed by transverse alternating-field electrophoresis, the ali DNA fragments were 10-15 kilobases smaller than the wild type. These fragments hybridized to probes both for VH and for a region of DNA a few kilobases downstream of the VH genes nearest the joining region. We suggest that this relatively small deletion affects a segment containing 3' VH genes with important regulatory functions, the loss of which leads to the ali phenotype. These results, and the fact that the 3' VH genes rearrange early in B-cell development, indicate that the 3' end of the VH locus probably plays a key role in regulation of VH gene expression.

  18. Camelid Single-Domain Antibodies: Historical Perspective and Future Outlook

    Directory of Open Access Journals (Sweden)

    Mehdi Arbabi-Ghahroudi

    2017-11-01

    Full Text Available Tremendous effort has been expended over the past two and a half decades to understand many aspects of camelid heavy chain antibodies, from their biology, evolution, and immunogenetics to their potential applications in various fields of research and medicine. In this article, I present a historical perspective on the development of camelid single-domain antibodies (sdAbs or VHHs, also widely known as nanobodies since their discovery and discuss the advantages and disadvantages of these unique molecules in various areas of research, industry, and medicine. Commercialization of camelid sdAbs exploded in 2001 with a flurry of patents issued to the Vrije Universiteit Brussel (VUB and later taken on by the Vlaams Interuniversitair Instituut voor Biotechnologie (VIB and, after 2002, the VIB-founded spin-off company, Ablynx. While entrepreneurial spirit has certainly catalyzed the exploration of nanobodies as marketable products, IP restrictions may be partially responsible for the relatively long time span between the discovery of these biomolecules and their entry into the pharmaceutical market. It is now anticipated that the first VHH-based antibody drug, Caplacizumab, a bivalent anti-vWF antibody for treating rare blood clotting disorders, may be approved and commercialized in 2018 or shortly thereafter. This elusive first approval, along with the expiry of key patents, may substantially alter the scientific and biomedical landscape surrounding camelid sdAbs and pave the way for their emergence as mainstream biotherapeutics.

  19. A chimeric receptor of the insulin-like growth factor receptor type 1 (IGFR1) and a single chain antibody specific to myelin oligodendrocyte glycoprotein activates the IGF1R signalling cascade in CG4 oligodendrocyte progenitors.

    Science.gov (United States)

    Annenkov, Alexander; Rigby, Anne; Amor, Sandra; Zhou, Dun; Yousaf, Nasim; Hemmer, Bernhard; Chernajovsky, Yuti

    2011-08-01

    In order to generate neural stem cells with increased ability to survive after transplantation in brain parenchyma we developed a chimeric receptor (ChR) that binds to myelin oligodendrocyte glycoprotein (MOG) via its ectodomain and activates the insulin-like growth factor receptor type 1 ‎‎(IGF1R) signalling cascade. Activation of this pro-survival pathway in response to ligand broadly available in the brain might increase neuroregenerative potential of transplanted precursors. The ChR was produced by fusing a MOG-specific single ‎chain antibody with the extracellular boundary of the IGF1R transmembrane segment. The ChR is expressed on the cellular surface, predominantly as a monomer, and is not N-glycosylated. To show MOG-dependent functionality of the ChR, neuroblastoma cells B104 expressing this ChR were stimulated with monolayers of cells expressing recombinant MOG. The ChR undergoes MOG-dependent tyrosine phosphorylation and homodimerisation. It promotes insulin and IGF-independent growth of the oligodendrocyte progenitor cell line CG4. The proposed mode of the ChR activation is by MOG-induced dimerisation which promotes kinase domain transphosphorylation, by-passing the requirement of conformation changes known to be important for IGF1R activation. Another ChR, which contains a segment of the β-chain ectodomain, was produced in an attempt to recapitulate some of these conformational changes, but proved non-functional. 2011 Elsevier B.V. All rights reserved.

  20. Impact of substrate contamination with mycotoxins, heavy metals and pesticides on the growth performance and composition of black soldier fly larvae (Hermetia illucens) for use in the feed and food value chain.

    Science.gov (United States)

    Purschke, Benedict; Scheibelberger, Rafaela; Axmann, Sonja; Adler, Andreas; Jäger, Henry

    2017-08-01

    Edible insects have emerged as an alternative and sustainable source of high-quality, animal-derived protein and fat for livestock production or direct human nutrition. During the production of insects, substrate quality is a key parameter to assure optimal insect biomass gain as well as the safety of feed and food derived from commercially reared insects. Therefore, the influence of a realistic substrate contamination scenario on growth performance and accumulation behaviour of black soldier fly larvae (BSFL; Hermetia illucens L.) was investigated. Newly hatched larvae were fed on a corn-based substrate spiked with heavy metals (As, Cd, Cr, Hg, Ni, Pb), mycotoxins (aflatoxins B1/B2/G2, deoxynivalenol, ochratoxin A, zearalenone) and pesticides (chlorpyrifos, chlorpyrifos-methyl, pirimiphos-methyl) under defined breeding conditions (10 days, 28°C, 67% relative humidity). The extent of contaminants' bioaccumulation in the larval tissue as well as the effect on growing determinants were examined. The applied heavy metal substrate contamination was shown to impair larval growing indicated by significantly lower post-trial larval mass and feed conversion ratio (FCR). Cd and Pb accumulation factors of 9 and 2, respectively, were determined, while the concentrations of other heavy metals in the larvae remained below the initial substrate concentration. In contrast, mycotoxins and pesticides have neither been accumulated in the larval tissue nor significantly affected the growing determinants in comparison with the control. The use of BSFL as livestock feed requires contaminant monitoring - especially for Cd and Pb - in the substrates as well as in feedstuff containing BSFL to ensure feed and food safety along the value chain.

  1. The production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi

    NARCIS (Netherlands)

    Joosten, V.; Lokman, C.; Hondel, C.A.M.J.J. van den; Punt, P.J.

    2003-01-01

    In this review we will focus on the current status and views concerning the production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi. We will focus on single-chain antibody fragment production (scFv and VHH) by these lower eukaryotes and the possible applications

  2. A Cholera Conjugate Vaccine Containing O-specific Polysaccharide (OSP of V. cholerae O1 Inaba and Recombinant Fragment of Tetanus Toxin Heavy Chain (OSP:rTTHc Induces Serum, Memory and Lamina Proprial Responses against OSP and Is Protective in Mice.

    Directory of Open Access Journals (Sweden)

    Md Abu Sayeed

    Full Text Available Vibrio cholerae is the cause of cholera, a severe watery diarrhea. Protection against cholera is serogroup specific. Serogroup specificity is defined by the O-specific polysaccharide (OSP component of lipopolysaccharide (LPS.Here we describe a conjugate vaccine for cholera prepared via squaric acid chemistry from the OSP of V. cholerae O1 Inaba strain PIC018 and a recombinant heavy chain fragment of tetanus toxin (OSP:rTTHc. We assessed a range of vaccine doses based on the OSP content of the vaccine (10-50 μg, vaccine compositions varying by molar loading ratio of OSP to rTTHc (3:1, 5:1, 10:1, effect of an adjuvant, and route of immunization.Immunized mice developed prominent anti-OSP and anti-TT serum IgG responses, as well as vibriocidal antibody and memory B cell responses following intramuscular or intradermal vaccination. Mice did not develop anti-squarate responses. Intestinal lamina proprial IgA responses targeting OSP occurred following intradermal vaccination. In general, we found comparable immune responses in mice immunized with these variations, although memory B cell and vibriocidal responses were blunted in mice receiving the highest dose of vaccine (50 μg. We found no appreciable change in immune responses when the conjugate vaccine was administered in the presence or absence of immunoadjuvant alum. Administration of OSP:rTTHc resulted in 55% protective efficacy in a mouse survival cholera challenge model.We report development of an Inaba OSP:rTTHc conjugate vaccine that induces memory responses and protection against cholera in mice. Development of an effective cholera conjugate vaccine that induces high level and long-term immune responses against OSP would be beneficial, especially in young children who respond poorly to polysaccharide antigens.

  3. Contribution of tryptophan residues to the combining site of a monoclonal anti dinitrophenyl spin-label antibody

    International Nuclear Information System (INIS)

    Anglister, J.; Bond, M.W.; Frey, T.; Leahy, D.; Levitt, M.; McConnell, H.M.; Rule, G.S.; Tomasello, J.; Whittaker, M.

    1987-01-01

    Two Fab fragments of the monoclonal anti dinitrophenyl (DNP) spin-label antibody AN02 were prepared by recombination of specifically deuterated heavy and light chains. In the recombinant H(I)L(II) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the heavy chain. In the recombinant H(II)L(I) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the light chain. Saturation of three resonances of H(I)L(II), assigned to tryptophan protons of the light chain, resulted in magnetization transfer to the aromatic proton at position 6 of the DNP ring and to the CH2 protons of the glycines linked to the DNP in a diamagnetic hapten (DNP-DG). Saturation of three resonances of H(II)L(I) assigned to tryptophan protons of the heavy chain resulted in magnetization transfer to the CH2 protons of the glycines in DNP-DG. From the dependence of the magnetization transfer on the irradiation time, the cross relaxation rates between the involved protons were estimated. The inferred distances between these protons of the hapten and certain tryptophan protons are 3-4 A. It is concluded that in the combining site of AN02 there is one tryptophan from the light chain and one tryptophan from the heavy chain that are very near the hapten. When all tyrosines and phenylalanines were perdeuterated and all tryptophan aromatic protons were deuterated except for the protons at positions 2 and 5, titration of the Fab fragments with variable amounts of paramagnetic hapten showed that one proton from the light chain tryptophan is near (less than 7 A) the unpaired electron and that three other protons are significantly closer than 15 A

  4. Contribution of tryptophan residues to the combining site of a monoclonal anti dinitrophenyl spin-label antibody

    Energy Technology Data Exchange (ETDEWEB)

    Anglister, J.; Bond, M.W.; Frey, T.; Leahy, D.; Levitt, M.; McConnell, H.M.; Rule, G.S.; Tomasello, J.; Whittaker, M.

    1987-09-22

    Two Fab fragments of the monoclonal anti dinitrophenyl (DNP) spin-label antibody AN02 were prepared by recombination of specifically deuterated heavy and light chains. In the recombinant H(I)L(II) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the heavy chain. In the recombinant H(II)L(I) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the light chain. Saturation of three resonances of H(I)L(II), assigned to tryptophan protons of the light chain, resulted in magnetization transfer to the aromatic proton at position 6 of the DNP ring and to the CH2 protons of the glycines linked to the DNP in a diamagnetic hapten (DNP-DG). Saturation of three resonances of H(II)L(I) assigned to tryptophan protons of the heavy chain resulted in magnetization transfer to the CH2 protons of the glycines in DNP-DG. From the dependence of the magnetization transfer on the irradiation time, the cross relaxation rates between the involved protons were estimated. The inferred distances between these protons of the hapten and certain tryptophan protons are 3-4 A. It is concluded that in the combining site of AN02 there is one tryptophan from the light chain and one tryptophan from the heavy chain that are very near the hapten. When all tyrosines and phenylalanines were perdeuterated and all tryptophan aromatic protons were deuterated except for the protons at positions 2 and 5, titration of the Fab fragments with variable amounts of paramagnetic hapten showed that one proton from the light chain tryptophan is near (less than 7 A) the unpaired electron and that three other protons are significantly closer than 15 A.

  5. ITIH4 (inter-alpha-trypsin inhibitor heavy chain 4) is a new acute-phase protein isolated from cattle during experimental infection

    DEFF Research Database (Denmark)

    Pineiro, M.; Andres, M.; Iturralde, M.

    2004-01-01

    We have isolated from calf serum a protein with an apparent M, of 120,000. The protein was detected by using antibodies against major acute-phase protein in pigs with acute inflammation. The amino acid sequence of an internal fragment revealed that this protein is the bovine counterpart of ITIH4......, and Peptostreptococcus indolicus to induce an acute-phase reaction. All animals developed moderate to severe clinical mastitis and exhibited remarkable increases in ITIH4 concentration in serum (from 3 to 12 times the initial values, peaking at 48 to 72 h after infection) that correlated with the severity of the disease....... Animals with experimental infections with bovine respiratory syncytial virus (BRSV) also showed increases in ITIH4 concentration (from two- to fivefold), which peaked at around 7 to 8 days after inoculation. Generally, no response was seen after a second infection of the same animals with the virus...

  6. Heavy leptons

    International Nuclear Information System (INIS)

    Smith, C.H.L.

    1977-01-01

    The possibility that a new lepton may exist is discussed under the headings; theoretical reasons for the introduction of heavy leptons, classification of heavy leptons (ortho and paraleptons), discrimination between different types of lepton, decays of charged heavy leptons, production of charged heavy leptons (in e + e - storage rings, neutrino production, photoproduction, and hadroproduction), neutral heavy leptons, and hadroleptons. (U.K.)

  7. Application and Comparative Evaluation of Fluorescent Antibody, Immunohistochemistry and Reverse Transcription Polymerase Chain Reaction Tests for the Detection of Rabies Virus Antigen or Nucleic Acid in Brain Samples of Animals Suspected of Rabies in India

    Directory of Open Access Journals (Sweden)

    K. Nithin Prabhu

    2018-02-01

    Full Text Available Accurate and early diagnosis of animal rabies is critical for undertaking public health measures. Whereas the direct fluorescent antibody (DFA technique is the recommended test, the more convenient, direct rapid immunochemistry test (dRIT, as well as the more sensitive, reverse transcription polymerase chain reaction (RT-PCR, have recently been employed for the laboratory diagnosis of rabies. We compared the three methods on brain samples from domestic (dog, cat, cattle, buffalo, horse, pig and goat and wild (leopard, wolf and jackal animals from various parts of India. Of the 257 samples tested, 167 were positive by all the three tests; in addition, 35 of the 36 decomposed samples were positive by RT-PCR. This is the first study in which such large number of animal samples have been subjected to the three tests simultaneously. The results confirm 100% corroboration between DFA and dRIT, buttress the applicability of dRIT in the simple and rapid diagnosis of rabies in animals, and reaffirm the suitability of RT-PCR for samples unfit for testing either by DFA or dRIT.

  8. Application and Comparative Evaluation of Fluorescent Antibody, Immunohistochemistry and Reverse Transcription Polymerase Chain Reaction Tests for the Detection of Rabies Virus Antigen or Nucleic Acid in Brain Samples of Animals Suspected of Rabies in India.

    Science.gov (United States)

    Prabhu, K Nithin; Isloor, Shrikrishna; Veeresh, B Hanchinal; Rathnamma, Doddamane; Sharada, R; Das, Lekshmi J; Satyanarayana, M L; Hegde, Nagendra R; Rahman, Sira Abdul

    2018-02-28

    Accurate and early diagnosis of animal rabies is critical for undertaking public health measures. Whereas the direct fluorescent antibody (DFA) technique is the recommended test, the more convenient, direct rapid immunochemistry test (dRIT), as well as the more sensitive, reverse transcription polymerase chain reaction (RT-PCR), have recently been employed for the laboratory diagnosis of rabies. We compared the three methods on brain samples from domestic (dog, cat, cattle, buffalo, horse, pig and goat) and wild (leopard, wolf and jackal) animals from various parts of India. Of the 257 samples tested, 167 were positive by all the three tests; in addition, 35 of the 36 decomposed samples were positive by RT-PCR. This is the first study in which such large number of animal samples have been subjected to the three tests simultaneously. The results confirm 100% corroboration between DFA and dRIT, buttress the applicability of dRIT in the simple and rapid diagnosis of rabies in animals, and reaffirm the suitability of RT-PCR for samples unfit for testing either by DFA or dRIT.

  9. A fully synthetic human Fab antibody library based on fixed VH/VL framework pairings with favorable biophysical properties

    Science.gov (United States)

    Tiller, Thomas; Schuster, Ingrid; Deppe, Dorothée; Siegers, Katja; Strohner, Ralf; Herrmann, Tanja; Berenguer, Marion; Poujol, Dominique; Stehle, Jennifer; Stark, Yvonne; Heßling, Martin; Daubert, Daniela; Felderer, Karin; Kaden, Stefan; Kölln, Johanna; Enzelberger, Markus; Urlinger, Stefanie

    2013-01-01

    This report describes the design, generation and testing of Ylanthia, a fully synthetic human Fab antibody library with 1.3E+11 clones. Ylanthia comprises 36 fixed immunoglobulin (Ig) variable heavy (VH)/variable light (VL) chain pairs, which cover a broad range of canonical complementarity-determining region (CDR) structures. The variable Ig heavy and Ig light (VH/VL) chain pairs were selected for biophysical characteristics favorable to manufacturing and development. The selection process included multiple parameters, e.g., assessment of protein expression yield, thermal stability and aggregation propensity in fragment antigen binding (Fab) and IgG1 formats, and relative Fab display rate on phage. The framework regions are fixed and the diversified CDRs were designed based on a systematic analysis of a large set of rearranged human antibody sequences. Care was taken to minimize the occurrence of potential posttranslational modification sites within the CDRs. Phage selection was performed against various antigens and unique antibodies with excellent biophysical properties were isolated. Our results confirm that quality can be built into an antibody library by prudent selection of unmodified, fully human VH/VL pairs as scaffolds. PMID:23571156

  10. Frequency and genetic characterization of V(DD)J recombinants in the human peripheral blood antibody repertoire.

    Science.gov (United States)

    Briney, Bryan S; Willis, Jordan R; Hicar, Mark D; Thomas, James W; Crowe, James E

    2012-09-01

    Antibody heavy-chain recombination that results in the incorporation of multiple diversity (D) genes, although uncommon, contributes substantially to the diversity of the human antibody repertoire. Such recombination allows the generation of heavy chain complementarity determining region 3 (HCDR3) regions of extreme length and enables junctional regions that, because of the nucleotide bias of N-addition regions, are difficult to produce through normal V(D)J recombination. Although this non-classical recombination process has been observed infrequently, comprehensive analysis of the frequency and genetic characteristics of such events in the human peripheral blood antibody repertoire has not been possible because of the rarity of such recombinants and the limitations of traditional sequencing technologies. Here, through the use of high-throughput sequencing of the normal human peripheral blood antibody repertoire, we analysed the frequency and genetic characteristics of V(DD)J recombinants. We found that these recombinations were present in approximately 1 in 800 circulating B cells, and that the frequency was severely reduced in memory cell subsets. We also found that V(DD)J recombination can occur across the spectrum of diversity genes, indicating that virtually all recombination signal sequences that flank diversity genes are amenable to V(DD)J recombination. Finally, we observed a repertoire bias in the diversity gene repertoire at the upstream (5') position, and discovered that this bias was primarily attributable to the order of diversity genes in the genomic locus. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

  11. Differences in Allelic Frequency and CDRH3 Region Limit the Engagement of HIV Env Immunogens by Putative VRC01 Neutralizing Antibody Precursors

    Directory of Open Access Journals (Sweden)

    Christina Yacoob

    2016-11-01

    Full Text Available Elicitation of broadly neutralizing antibodies remains a long-standing goal of HIV vaccine research. Although such antibodies can arise during HIV-1 infection, gaps in our knowledge of their germline, pre-immune precursor forms, as well as on their interaction with viral Env, limit our ability to elicit them through vaccination. Studies of broadly neutralizing antibodies from the VRC01-class provide insight into progenitor B cell receptors (BCRs that could develop into this class of antibodies. Here, we employed high-throughput heavy chain variable region (VH/light chain variable region (VL deep sequencing, combined with biophysical, structural, and modeling antibody analyses, to interrogate circulating potential VRC01-progenitor BCRs in healthy individuals. Our study reveals that not all humans are equally predisposed to generate VRC01-class antibodies, not all predicted progenitor VRC01-expressing B cells can bind to Env, and the CDRH3 region of germline VRC01 antibodies influence their ability to recognize HIV-1. These findings will be critical to the design of optimized immunogens that should consider CDRH3 interactions.

  12. Rapid preparative separation of monoclonal antibody charge variants using laterally-fed membrane chromatography.

    Science.gov (United States)

    Sadavarte, Rahul; Madadkar, Pedram; Filipe, Carlos Dm; Ghosh, Raja

    2018-01-15

    Monoclonal antibodies undergo various forms of chemical transformation which have been shown to cause loss in efficacy and alteration in pharmacokinetic properties of these molecules. Such modified antibody molecules are known as variants. They also display physical properties such as charge that are different from intact antibody molecules. However, the difference in charge is very subtle and separation based on it is quite challenging. Charge variants are usually separated using ion-exchange column chromatography or isoelectric focusing. In this paper, we report a rapid and scalable method for fractionating monoclonal antibody charge variants, based on the use of cation exchange laterally-fed membrane chromatography (LFMC). Starting with a sample of monoclonal antibody hIgG1-CD4, three well-resolved fractions were obtained using either pH or salt gradient. These fractions were identified as acidic, neutral and basic variants. Each of these fractions contained intact heavy and light chains and so antibody fragmentation had no role in variant generation. The separation was comparable to that using column chromatography but was an order of magnitude faster. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Genetic engineering of cell lines using lentiviral vectors to achieve antibody secretion following encapsulated implantation.

    Science.gov (United States)

    Lathuilière, Aurélien; Bohrmann, Bernd; Kopetzki, Erhard; Schweitzer, Christoph; Jacobsen, Helmut; Moniatte, Marc; Aebischer, Patrick; Schneider, Bernard L

    2014-01-01

    The controlled delivery of antibodies by immunoisolated bioimplants containing genetically engineered cells is an attractive and safe approach for chronic treatments. To reach therapeutic antibody levels there is a need to generate renewable cell lines, which can long-term survive in macroencapsulation devices while maintaining high antibody specific productivity. Here we have developed a dual lentiviral vector strategy for the genetic engineering of cell lines compatible with macroencapsulation, using separate vectors encoding IgG light and heavy chains. We show that IgG expression level can be maximized as a function of vector dose and transgene ratio. This approach allows for the generation of stable populations of IgG-expressing C2C12 mouse myoblasts, and for the subsequent isolation of clones stably secreting high IgG levels. Moreover, we demonstrate that cell transduction using this lentiviral system leads to the production of a functional glycosylated antibody by myogenic cells. Subsequent implantation of antibody-secreting cells in a high-capacity macroencapsulation device enables continuous delivery of recombinant antibodies in the mouse subcutaneous tissue, leading to substantial levels of therapeutic IgG detectable in the plasma.

  14. Detection of koi herpesvirus (KHV) using a monoclonal antibody against Cyprinus carpio IgM.

    Science.gov (United States)

    Li, Yingying; Zheng, Shucheng; Wang, Qing; Bergmann, Sven M; Zeng, Weiwei; Wang, Yingying; Liu, Chun; Shi, Cunbin

    2017-08-01

    Koi herpesvirus disease (KHVD) is associated with high mortality in both common carp and koi carp (Cyprinus carpio L.) worldwide. The indirect detection of fish viruses based on the identification of antibodies has emerged as a practical and reliable means of diagnosis. Thus, it is important to create monoclonal antibodies (MAbs) against carp IgM. By using hybridoma-monoclonal antibody technology, one hybridoma cell line secreting MAbs against IgM from carp was established. In western blot analysis, the secreted MAb from cell line A5-E10 recognized the heavy chain of IgM from common carp or koi but did not react with immunoglobulins from three different fish species: grass carp (Ctenopharyngodon idella), tilapia (Oreochromis mossambicus) and Mandarin fish (Siniperca chuatsi). These results demonstrated that this MAb is highly specific for the IgM of carp and suggested that it can be used for monitoring the immunity level of carp, for example for indirect KHV diagnosis by antibody ELISA. We therefore established an indirect ELISA, which was tested using 200 serum samples from koi from three farms. The final results showed that 147 (73.5%) samples were confirmed to be KHV antibody negative and 53 (26.5%) were definitely positive, containing antibodies against KHV.

  15. Rapid production of antigen-specific monoclonal antibodies from a variety of animals

    Directory of Open Access Journals (Sweden)

    Kurosawa Nobuyuki

    2012-09-01

    Full Text Available Abstract Background Although a variety of animals have been used to produce polyclonal antibodies against antigens, the production of antigen-specific monoclonal antibodies from animals remains challenging. Results We propose a simple and rapid strategy to produce monoclonal antibodies from a variety of animals. By staining lymph node cells with an antibody against immunoglobulin and a fluorescent dye specific for the endoplasmic reticulum, plasma/plasmablast cells were identified without using a series of antibodies against lineage markers. By using a fluorescently labeled antigen as a tag for a complementary cell surface immunoglobulin, antigen-specific plasma/plasmablast cells were sorted from the rest of the cell population by fluorescence-activated cell sorting. Amplification of cognate pairs of immunoglobulin heavy and light chain genes followed by DNA transfection into 293FT cells resulted in the highly efficient production of antigen-specific monoclonal antibodies from a variety of immunized animals. Conclusions Our technology eliminates the need for both cell propagation and screening processes, offering a significant advantage over hybridoma and display strategies.

  16. An efficient method for isolating antibody fragments against small peptides by antibody phage display

    DEFF Research Database (Denmark)

    Duan, Zhi; Siegumfeldt, Henrik

    2010-01-01

    We generated monoclonal scFv (single chain variable fragment) antibodies from an antibody phage display library towards three small synthetic peptides derived from the sequence of s1-casein. Key difficulties for selection of scFv-phages against small peptides were addressed. Small peptides do....... The scFvs were sequenced and characterized, and specificity was characterized by ELISA. The methods developed in this study are universally applicable for antibody phage display to efficiently produce antibody fragments against small peptides....

  17. 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

  18. Selective disulfide reduction for labeling and enhancement of Fab antibody fragments

    International Nuclear Information System (INIS)

    Kirley, Terence L.; Greis, Kenneth D.; Norman, Andrew B.

    2016-01-01

    Many methods have been developed for chemical labeling and enhancement of the properties of antibodies and their common fragments, including the Fab and F(ab’) 2 fragments. Somewhat selective reduction of some antibody disulfide bonds has been previously achieved, yielding antibodies and antibody fragments that can be labeled at defined sites, enhancing their utility and properties. Selective reduction of the two hinge disulfide bonds present in F(ab’) 2 fragments using mild reduction has been useful. However, such reduction is often not quantitative and results in the reduction of multiple disulfide bonds, and therefore subsequent multiple labeling or conjugation sites are neither homogenous nor stoichiometric. Here, a simple and efficient selective reduction of the single disulfide bond linking the partial heavy chain and the intact light chain which compose the Fab fragment is accomplished utilizing tris(2-carboxyethyl)phosphine (TCEP) immobilized on agarose beads. The resultant reduced cysteine residues were labeled with several cysteine-selective fluorescent reagents, as well as by cysteine-directed PEGylation. These two cysteine residues can also be re-ligated by means of a bifunctional cysteine cross-linking agent, dibromobimane, thereby both restoring a covalent linkage between the heavy and light chains at this site, far removed from the antigen binding site, and also introducing a fluorescent probe. There are many other research and clinical uses for these selectively partially reduced Fab fragments, including biotinylation, toxin and drug conjugation, and incorporation of radioisotopes, and this technique enables simple generation of very useful Fab fragment derivatives with many potential applications. - Highlights: • TCEP agarose is effective for selective reduction of a single Fab disulfide bond. • This disulfide is solvent accessible and distant from the antigen binding site. • A variety of buffers of varying pHs can be used, simplifying

  19. Selective disulfide reduction for labeling and enhancement of Fab antibody fragments.

    Science.gov (United States)

    Kirley, Terence L; Greis, Kenneth D; Norman, Andrew B

    2016-11-25

    Many methods have been developed for chemical labeling and enhancement of the properties of antibodies and their common fragments, including the Fab and F(ab') 2 fragments. Somewhat selective reduction of some antibody disulfide bonds has been previously achieved, yielding antibodies and antibody fragments that can be labeled at defined sites, enhancing their utility and properties. Selective reduction of the two hinge disulfide bonds present in F(ab') 2 fragments using mild reduction has been useful. However, such reduction is often not quantitative and results in the reduction of multiple disulfide bonds, and therefore subsequent multiple labeling or conjugation sites are neither homogenous nor stoichiometric. Here, a simple and efficient selective reduction of the single disulfide bond linking the partial heavy chain and the intact light chain which compose the Fab fragment is accomplished utilizing tris(2-carboxyethyl)phosphine (TCEP) immobilized on agarose beads. The resultant reduced cysteine residues were labeled with several cysteine-selective fluorescent reagents, as well as by cysteine-directed PEGylation. These two cysteine residues can also be re-ligated by means of a bifunctional cysteine cross-linking agent, dibromobimane, thereby both restoring a covalent linkage between the heavy and light chains at this site, far removed from the antigen binding site, and also introducing a fluorescent probe. There are many other research and clinical uses for these selectively partially reduced Fab fragments, including biotinylation, toxin and drug conjugation, and incorporation of radioisotopes, and this technique enables simple generation of very useful Fab fragment derivatives with many potential applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Epitope mapping of functional domains of human factor V with human and mouse monoclonal antibodies

    International Nuclear Information System (INIS)

    Annamalai, A.E.; Rao, A.K.; Chiu, H.C.; Wang, D.; Dutta-Roy, A.K.; Colman, R.W.

    1986-01-01

    The authors previously described two human monoclonal antibodies (MAbs) which inactivated factor V. The authors have now purified the predominant antibody (H2) on protein A Sepharose using a pH gradient and typed it as IgG 1 ,. Immunoprecipitation of 125 I-human factor Va with H2 demonstrated specificity for the heavy chain (D), Mr = 105,000. The authors compared using ELISA the competitive binding to factor Va, of H2, H1 and two mouse MAbs, B38 (directed to E) and B10 (to activation peptide, Cl). All four antibodies recognized distinct epitopes in factor V with steric overlap in some cases. Factor Xa showed a concentration dependent competition for binding of H1, H2 and B38 but not B10 to factor V/Va in ELISA. All MAbs bound to factor V/Va in the absence of Ca ++ . However, Ca ++ at 8 mM increased the binding of H1 and H2 to 165% and 360% and did not have any effect on the binding of either mouse MAbs. Prothrombin at a concentration of up to 400 μg/ml did not inhibit binding of any of these antibodies. Thus, both the light (E) and heavy (D) chains of factor Va but not the activation peptide (Cl) interact with factor Xa as defined by the MAbs. In addition, sites on both chains for Ca ++ are recognized by particular MAbs (H1 and H2). These studies increase their knowledge of the interactions of factor V domains in the formation of prothrombinase complex

  1. Reversible dimer formation and stability of the anti-tumour single-chain Fv antibody MFE-23 by neutron scattering, analytical ultracentrifugation, and NMR and FT-IR spectroscopy.

    Science.gov (United States)

    Lee, Yie Chia; Boehm, Mark K; Chester, Kerry A; Begent, Richard H J; Perkins, Stephen J

    2002-06-28

    MFE-23 is a single chain Fv (scFv) antibody molecule used to target colorectal cancer through its high affinity for the tumour marker carcinoembryonic antigen (CEA). ScFv molecules are formed from peptide-linked antibody V(H) and V(L) domains, and many of these form dimers. Our recent crystal structure for MFE-23 showed that this formed an unusual symmetric back-to-back association of two monomers that is consistent with a domain-swapped diabody structure. Neutron scattering and modelling fits showed that MFE-23 existed as compact V(H)-V(L)-linked monomers at therapeutically relevant concentrations below 1 mg/ml. Size-exclusion gel chromatography showed that the monomeric and dimeric forms of MFE-23 could be separated, and that the proportions of these two forms depended on the starting MFE-23 concentration. Sedimentation equilibrium experiments by analytical ultracentrifugation at nine concentrations of MFE-23 indicated a reversible monomer-dimer self-association equilibrium with an association constant of 1.9x10(3)-2.2x10(3) M(-1). Sedimentation velocity experiments using the time derivative g(s(*)) method showed that MFE-23-His has a concentration-dependent weight average sedimentation coefficient that increased from 1.8 S for the monomer to about 3-6 S for the dimer. Both values agreed with those calculated from the MFE-23 crystal structure. In relation to the thermal stability of MFE-23, denaturation experiments by (1)H NMR and FT-IR spectroscopy showed that the molecule is stable up to 47 degrees C, after which denaturation was irreversible. MFE-23 dimerisation is discussed in terms of a new model for diabody structures, in which the V(H) and V(L) domains in the monomer are able to dissociate and reassociate to form a dimer, or diabody, but in which symmetric back-to-back contacts between the two monomers are formed. This dimerisation in solution is attributed to the complementary nature of the C-terminal surface of the MFE-23 monomer. Crystal structures for

  2. Beyond CDR-grafting: Structure-guided humanization of framework and CDR regions of an anti-myostatin antibody.

    Science.gov (United States)

    Apgar, James R; Mader, Michelle; Agostinelli, Rita; Benard, Susan; Bialek, Peter; Johnson, Mark; Gao, Yijie; Krebs, Mark; Owens, Jane; Parris, Kevin; St Andre, Michael; Svenson, Kris; Morris, Carl; Tchistiakova, Lioudmila

    2016-10-01

    Antibodies are an important class of biotherapeutics that offer specificity to their antigen, long half-life, effector function interaction and good manufacturability. The immunogenicity of non-human-derived antibodies, which can be a major limitation to development, has been partially overcome by humanization through complementarity-determining region (CDR) grafting onto human acceptor frameworks. The retention of foreign content in the CDR regions, however, is still a potential immunogenic liability. Here, we describe the humanization of an anti-myostatin antibody utilizing a 2-step process of traditional CDR-grafting onto a human acceptor framework, followed by a structure-guided approach to further reduce the murine content of CDR-grafted antibodies. To accomplish this, we solved the co-crystal structures of myostatin with the chimeric (Protein Databank (PDB) id 5F3B) and CDR-grafted anti-myostatin antibody (PDB id 5F3H), allowing us to computationally predict the structurally important CDR residues as well as those making significant contacts with the antigen. Structure-based rational design enabled further germlining of the CDR-grafted antibody, reducing the murine content of the antibody without affecting antigen binding. The overall "humanness" was increased for both the light and heavy chain variable regions.

  3. Exploiting light chains for the scalable generation and platform purification of native human bispecific IgG

    Science.gov (United States)

    Fischer, Nicolas; Elson, Greg; Magistrelli, Giovanni; Dheilly, Elie; Fouque, Nicolas; Laurendon, Amélie; Gueneau, Franck; Ravn, Ulla; Depoisier, Jean-François; Moine, Valery; Raimondi, Sylvain; Malinge, Pauline; Di Grazia, Laura; Rousseau, François; Poitevin, Yves; Calloud, Sébastien; Cayatte, Pierre-Alexis; Alcoz, Mathias; Pontini, Guillemette; Fagète, Séverine; Broyer, Lucile; Corbier, Marie; Schrag, Delphine; Didelot, Gérard; Bosson, Nicolas; Costes, Nessie; Cons, Laura; Buatois, Vanessa; Johnson, Zoe; Ferlin, Walter; Masternak, Krzysztof; Kosco-Vilbois, Marie

    2015-01-01

    Bispecific antibodies enable unique therapeutic approaches but it remains a challenge to produce them at the industrial scale, and the modifications introduced to achieve bispecificity often have an impact on stability and risk of immunogenicity. Here we describe a fully human bispecific IgG devoid of any modification, which can be produced at the industrial scale, using a platform process. This format, referred to as a κλ-body, is assembled by co-expressing one heavy chain and two different light chains, one κ and one λ. Using ten different targets, we demonstrate that light chains can play a dominant role in mediating specificity and high affinity. The κλ-bodies support multiple modes of action, and their stability and pharmacokinetic properties are indistinguishable from therapeutic antibodies. Thus, the κλ-body represents a unique, fully human format that exploits light-chain variable domains for antigen binding and light-chain constant domains for robust downstream processing, to realize the potential of bispecific antibodies. PMID:25672245

  4. New cell line development for antibody-producing Chinese hamster ovary cells using split green fluorescent protein

    Directory of Open Access Journals (Sweden)

    Kim Yeon-Gu

    2012-05-01

    Full Text Available Abstract Background The establishment of high producer is an important issue in Chinese hamster ovary (CHO cell culture considering increased heterogeneity by the random integration of a transfected foreign gene and the altered position of the integrated gene. Fluorescence-activated cell sorting (FACS-based cell line development is an efficient strategy for the selection of CHO cells in high therapeutic protein production. Results An internal ribosome entry site (IRES was introduced for using two green fluorescence protein (GFP fragments as a reporter to both antibody chains, the heavy chain and the light chain. The cells co-transfected with two GFP fragments showed the emission of green fluorescence by the reconstitution of split GFP. The FACS-sorted pool with GFP expression had a higher specific antibody productivity (qAb than that of the unsorted pool. The qAb was highly correlated with the fluorescence intensity with a high correlation coefficient, evidenced from the analysis of median GFP and qAb in individual selected clones. Conclusions This study proved that the fragment complementation for split GFP could be an efficient indication for antibody production on the basis of high correlation of qAb with reconstitution of GFP. Taken together, we developed an efficient FACS-based screening method for high antibody-producing CHO cells with the benefits of the split GFP system.

  5. Time resolved native ion-mobility mass spectrometry to monitor dynamics of IgG4 Fab arm exchange and "bispecific" monoclonal antibody formation.

    Science.gov (United States)

    Debaene, François; Wagner-Rousset, Elsa; Colas, Olivier; Ayoub, Daniel; Corvaïa, Nathalie; Van Dorsselaer, Alain; Beck, Alain; Cianférani, Sarah

    2013-10-15

    Monoclonal antibodies (mAbs) and derivatives such as antibody-drug conjugates (ADC) and bispecific antibodies (bsAb), are the fastest growing class of human therapeutics. Most of the therapeutic antibodies currently on the market and in clinical trials are chimeric, humanized, and human immunoglobulin G1 (IgG1). An increasing number of IgG2s and IgG4s that have distinct structural and functional properties are also investigated to develop products that lack or have diminished antibody effector functions compared to IgG1. Importantly, wild type IgG4 has been shown to form half molecules (one heavy chain and one light chain) that lack interheavy chain disulfide bonds and form intrachain disulfide bonds. Moreover, IgG4 undergoes a process of Fab-arm exchange (FAE) in which the heavy chains of antibodies of different specificities can dissociate and recombine in bispecific antibodies both in vitro and in vivo. Here, native mass spectrometry (MS) and time-resolved traveling wave ion mobility MS (TWIM-MS) were used for the first time for online monitoring of FAE and bsAb formation using Hz6F4-2v3 and natalizumab, two humanized IgG4s which bind to human Junctional Adhesion Molecule-A (JAM-A) and alpha4 integrin, respectively. In addition, native MS analysis of bsAb/JAM-A immune complexes revealed that bsAb can bind up to two antigen molecules, confirming that the Hz6F4 family preferentially binds dimeric JAM-A. Our results illustrate how IM-MS can rapidly assess bsAb structural heterogeneity and be easily implemented into MS workflows for bsAb production follow up and bsAb/antigen complex characterization. Altogether, these results provide new MS-based methodologies for in-depth FAE and bsAb formation monitoring. Native MS and IM-MS will play an increasing role in next generation biopharmaceutical product characterization like bsAbs, antibody mixtures, and antibody-drug conjugates (ADC) as well as for biosimilar and biobetter antibodies.

  6. Experimental and in silico modelling analyses of the gene expression pathway for recombinant antibody and by-product production in NS0 cell lines.

    Science.gov (United States)

    Mead, Emma J; Chiverton, Lesley M; Spurgeon, Sarah K; Martin, Elaine B; Montague, Gary A; Smales, C Mark; von der Haar, Tobias

    2012-01-01

    Monoclonal antibodies are commercially important, high value biotherapeutic drugs used in the treatment of a variety of diseases. These complex molecules consist of two heavy chain and two light chain polypeptides covalently linked by disulphide bonds. They are usually expressed as recombinant proteins from cultured mammalian cells, which are capable of correctly modifying, folding and assembling the polypeptide chains into the native quaternary structure. Such recombinant cell lines often vary in the amounts of product produced and in the heterogeneity of the secreted products. The biological mechanisms of this variation are not fully defined. Here we have utilised experimental and modelling strategies to characterise and define the biology underpinning product heterogeneity in cell lines exhibiting varying antibody expression levels, and then experimentally validated these models. In undertaking these studies we applied and validated biochemical (rate-constant based) and engineering (nonlinear) models of antibody expression to experimental data from four NS0 cell lines with different IgG4 secretion rates. The models predict that export of the full antibody and its fragments are intrinsically linked, and cannot therefore be manipulated individually at the level of the secretory machinery. Instead, the models highlight strategies for the manipulation at the precursor species level to increase recombinant protein yields in both high and low producing cell lines. The models also highlight cell line specific limitations in the antibody expression pathway.

  7. Diversity and maturation in the anti-dansyl antibody response of the Balb/C mouse

    International Nuclear Information System (INIS)

    Burns, F.R.

    1987-01-01

    Ten hybridoma cell lines that produce antibodies with specificity for the 5-dimethylaminonaphthalene-1-sulfonyl(dansyl)-lysine hapten, were studied. Single stranded cDNAs were generated by reverse transcription of the immunoglobulin (Ig) mRNAs primed by 5' P-32 labeled oligonucleotides complementary to specific regions of the Ig message. Nucleic acid sequences of 4 mu heavy chains was sufficient to reveal that the early immune response involves members of at least three distinct heavy chain variable region (V/sub H/) gene families. Nucleic acid sequences and Southern blot data from 6 gamma heavy chains reveal that the gamma response is comprised of members of only a single V/sub H/ family although representation from that family derives from at least three distinguishable germline genes. The abrupt restriction of V/sub H/ family usage at the point of class switch can not be explained on the basis of antigen driven selection or of idio-type repression. The data indicate a mechanism for preferential class switch of a particular V/sub H/ family independent of affinity considerations or repression of other idiotypes

  8. Diversity and maturation in the anti-dansyl antibody response of the Balb/C mouse

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F.R.

    1987-01-01

    Ten hybridoma cell lines that produce antibodies with specificity for the 5-dimethylaminonaphthalene-1-sulfonyl(dansyl)-lysine hapten, were studied. Single stranded cDNAs were generated by reverse transcription of the immunoglobulin (Ig) mRNAs primed by 5' P-32 labeled oligonucleotides complementary to specific regions of the Ig message. Nucleic acid sequences of 4 mu heavy chains was sufficient to reveal that the early immune response involves members of at least three distinct heavy chain variable region (V/sub H/) gene families. Nucleic acid sequences and Southern blot data from 6 gamma heavy chains reveal that the gamma response is comprised of members of only a single V/sub H/ family although representation from that family derives from at least three distinguishable germline genes. The abrupt restriction of V/sub H/ family usage at the point of class switch can not be explained on the basis of antigen driven selection or of idio-type repression. The data indicate a mechanism for preferential class switch of a particular V/sub H/ family independent of affinity considerations or repression of other idiotypes.

  9. Myocardial gene expression of microRNA-133a and myosin heavy and light chains, in conjunction with clinical parameters, predict regression of left ventricular hypertrophy after valve replacement in patients with aortic stenosis.

    Science.gov (United States)

    Villar, Ana V; Merino, David; Wenner, Mareike; Llano, Miguel; Cobo, Manuel; Montalvo, Cecilia; García, Raquel; Martín-Durán, Rafael; Hurlé, Juan M; Hurlé, María A; Nistal, J Francisco

    2011-07-01

    Left ventricular (LV) reverse remodelling after valve replacement in aortic stenosis (AS) has been classically linked to the hydraulic performance of the replacement device, but myocardial status at the time of surgery has received little attention. To establish predictors of LV mass (LVM) regression 1 year after valve replacement in a surgical cohort of patients with AS based on preoperative clinical and echocardiographic parameters and the myocardial gene expression profile at surgery. Transcript levels of remodelling-related proteins and regulators were determined in LV intraoperative biopsies from 46 patients with AS by RT-PCR. Using multiple linear regression analysis, an equation was developed (adjusted R²=0.73; pregression analysis identified microRNA-133a as a significant positive predictor of LVM normalisation, whereas β-myosin heavy chain and BMI constituted negative predictors. Hypertrophy regression 1 year after pressure overload release is related to the preoperative myocardial expression of remodelling-related genes, in conjunction with the patient's clinical background. In this scenario, miR-133 emerges as a key element of the reverse remodelling process. Postoperative improvement of valve haemodynamics does not predict the degree of hypertrophy regression or LVM normalisation. These results led us to reconsider the current reverse remodelling paradigm and (1) to include criteria of hypertrophy reversibility in the decision algorithm used to decide timing for the operation; and (2) to modify other prevailing factors (overweight, diabetes, etc) known to maintain LV hypertrophy.

  10. [Identification and production of monoclonal antibody of Siberian tiger's immunoglobulin].

    Science.gov (United States)

    Zhang, Yaonglong; Zhang, Duanling; Zhou, Ming; Xue, Yuan; Hua, Yuping; Ma, Jianzhang

    2010-03-01

    To purify immunoglobulin (Ig) of Siberian Tiger and prepare monoclonal antibody (mAb) against the Ig,which can be used to develop immunological diagnostic kits for diagnosing infectious disease in Siberian Tiger. The Ig of Siberian tigers was purified with saturated ammonium sulfate combined with recombinant Protein G. The C57BL/6 mice were immunized with the purified Ig. Spleno-cytes of the mice immunized were collected and fused with the mouse myeloma cell line (Sp2/0-Ag14). The positive hybridoma clones were selected by ELISA and were identified by western blot. The sandwich ELISA was used to detect immunocompetence of the purified Ig and the mAb. We obtained three mouse hybridoma clones that produced mAbs against Ig of Siberian Tiger. The derived McAbs could recognize Ig heavy chain of Siberian Tiger specifically. The biological activity of the Ig and obtained McAbs also could be identified by detecting the antibody induced by panleukopenia virus (FPV-HLJ) vaccine in Siberian Tiger. The antibody also would be useful for assess the vaccine efficacy against the infectious disease on the Siberian Tiger. Protein G can be used in Ig purification of Siberian Tiger. The obtained McAbs from the hybridoma ADT11 in this study owned strong ability to bind Ig of Siberian Tiger and have a stable immunocompetence. They can be used to develop diagnostic methods for detecting infectious disease in Siberian Tiger and vaccine research.

  11. Using llama derived single domain antibodies to target botulinum neurotoxins

    Science.gov (United States)

    Swain, Marla D.; Anderson, George P.; Bernstein, Rachael D.; Liu, Jinny L.; Goldman, Ellen R.

    2010-04-01

    Llama serum contains both conventional IgG as well as unique forms of antibody that contain only heavy chains where antigen binding is mediated through a single variable domain. These variable domains can be expressed recombinantly and are referred to as single domain antibodies (sdAb). SdAb are among the smallest known naturally derived antigen binding fragments, possess good solubility, thermal stability, and can refold after heat and chemical denaturation. Llamas were immunized with either BoNT A or B toxoid and phage display libraries prepared. Single domain antibodies (sdAb) that were able to detect botulinum neurotoxin (BoNT) serotypes A and B were selected from their respective libraries. Here, the binders obtained by panning the BoNT B library on either BoNT B toxoid or BoNT B complex toxoid coated plates or BoNT B toxin coupled microspheres are described. Using these panning methods, we selected for binders that showed specificity for BoNT B. Phage displayed binders were screened, moved to a protein expression vector and soluble sdAb was produced. Using a Luminex flow cytometer binders were evaluated in direct binding assays. We have exploited the unique properties of sdAb and used them as biological recognition elements in immuno-based sensors that can detect BoNT B.

  12. Monoclonal antibody

    International Nuclear Information System (INIS)

    Oyamada, Hiyoshimaru

    1987-01-01

    Some aspects of monoclonal antibodies are described, centering on studies made by the author and those presented at the Second International Conference on Monoclonal Antibody Immunoconjugates for Cancer held in March this year (1987). The history of immuno-nuclear medicine and procedures for producing monoclonal antibodies are briefly outlined. Monoclonal antibodies are immunoglobulins. Here, the structure of IgG, which is used most frequently, is described. An IgG is composed of two antigen binding fragments (Fab) and one crystallizable fragment (Fc). The end portion of a Fab reacts with an antigen. One of the major applications of immuno-nuclear medicine is the diagnosis of cancer. As label nucleides, 131 I and 111 I were selected in most cases in the past while 123 I and 99m Tc are currently used more often. Advantages and disadvantages of this diagnosis method is discussed citing studies presented at the First (1986) and Second (1987) International Conference on Monoclonal Antibody Immunoconjugates for Cancer. The present status of the application of monoclonal antibodies to treatment of cancer is also described. (Nogami, K.)

  13. Molecular evolution of broadly neutralizing Llama antibodies to the CD4-binding site of HIV-1.

    Science.gov (United States)

    McCoy, Laura E; Rutten, Lucy; Frampton, Dan; Anderson, Ian; Granger, Luke; Bashford-Rogers, Rachael; Dekkers, Gillian; Strokappe, Nika M; Seaman, Michael S; Koh, Willie; Grippo, Vanina; Kliche, Alexander; Verrips, Theo; Kellam, Paul; Fassati, Ariberto; Weiss, Robin A

    2014-12-01

    To date, no immunization of humans or animals has elicited broadly neutralizing sera able to prevent HIV-1 transmission; however, elicitation of broad and potent heavy chain only antibodies (HCAb) has previously been reported in llamas. In this study, the anti-HIV immune responses in immunized llamas were studied via deep sequencing analysis using broadly neutralizing monoclonal HCAbs as a guides. Distinct neutralizing antibody lineages were identified in each animal, including two defined by novel antibodies (as variable regions called VHH) identified by robotic screening of over 6000 clones. The combined application of five VHH against viruses from clades A, B, C and CRF_AG resulted in neutralization as potent as any of the VHH individually and a predicted 100% coverage with a median IC50 of 0.17 µg/ml for the panel of 60 viruses tested. Molecular analysis of the VHH repertoires of two sets of immunized animals showed that each neutralizing lineage was only observed following immunization, demonstrating that they were elicited de novo. Our results show that immunization can induce potent and broadly neutralizing antibodies in llamas with features similar to human antibodies and provide a framework to analyze the effectiveness of immunization protocols.

  14. Pentavalent single-domain antibodies reduce Campylobacter jejuni motility and colonization in chickens.

    Directory of Open Access Journals (Sweden)

    Ali Riazi

    Full Text Available Campylobacter jejuni is the leading cause of bacterial foodborne illness in the world, with symptoms ranging from acute diarrhea to severe neurological disorders. Contaminated poultry meat is a major source of C. jejuni infection, and therefore, strategies to reduce this organism in poultry, are expected to reduce the incidence of Campylobacter-associated diseases. We have investigated whether oral administration of C. jejuni-specific single-domain antibodies would reduce bacterial colonization levels in chickens. Llama single-domain antibodies specific for C. jejuni were isolated from a phage display library generated from the heavy chain IgG variable domain repertoire of a llama immunized with C. jejuni flagella. Two flagella-specific single-domain antibodies were pentamerized to yield high avidity antibodies capable of multivalent binding to the target antigen. When administered orally to C. jejuni-infected two-day old chicks, the pentabodies significantly reduced C. jejuni colonization in the ceca. In vitro, the motility of the bacteria was also reduced in the presence of the flagella-specific pentabodies, suggesting the mechanism of action is through either direct interference with flagellar motility or antibody-mediated aggregation. Fluorescent microscopy and Western blot analyses revealed specific binding of the anti-flagella pentabodies to the C. jejuni flagellin.

  15. IGHV1-69 B cell chronic lymphocytic leukemia antibodies cross-react with HIV-1 and hepatitis C virus antigens as well as intestinal commensal bacteria.

    Directory of Open Access Journals (Sweden)

    Kwan-Ki Hwang

    Full Text Available B-cell chronic lymphocytic leukemia (B-CLL patients expressing unmutated immunoglobulin heavy variable regions (IGHVs use the IGHV1-69 B cell receptor (BCR in 25% of cases. Since HIV-1 envelope gp41 antibodies also frequently use IGHV1-69 gene segments, we hypothesized that IGHV1-69 B-CLL precursors may contribute to the gp41 B cell response during HIV-1 infection. To test this hypothesis, we rescued 5 IGHV1-69 unmutated antibodies as heterohybridoma IgM paraproteins and as recombinant IgG1 antibodies from B-CLL patients, determined their antigenic specificities and analyzed BCR sequences. IGHV1-69 B-CLL antibodies were enriched for reactivity with HIV-1 envelope gp41, influenza, hepatitis C virus E2 protein and intestinal commensal bacteria. These IGHV1-69 B-CLL antibodies preferentially used IGHD3 and IGHJ6 gene segments and had long heavy chain complementary determining region 3s (HCDR3s (≥21 aa. IGHV1-69 B-CLL BCRs exhibited a phenylalanine at position 54 (F54 of the HCDR2 as do rare HIV-1 gp41 and influenza hemagglutinin stem neutralizing antibodies, while IGHV1-69 gp41 antibodies induced by HIV-1 infection predominantly used leucine (L54 allelic variants. These results demonstrate that the B-CLL cell population is an expansion of members of the innate polyreactive B cell repertoire with reactivity to a number of infectious agent antigens including intestinal commensal bacteria. The B-CLL IGHV1-69 B cell usage of F54 allelic variants strongly suggests that IGHV1-69 B-CLL gp41 antibodies derive from a restricted B cell pool that also produces rare HIV-1 gp41 and influenza hemagglutinin stem antibodies.

  16. Bivalent Llama Single-Domain Antibody Fragments against Tumor Necrosis Factor Have Picomolar Potencies due to Intramolecular Interactions

    Directory of Open Access Journals (Sweden)

    Els Beirnaert

    2017-07-01

    Full Text Available The activity of tumor necrosis factor (TNF, a cytokine involved in inflammatory pathologies, can be inhibited by antibodies or trap molecules. Herein, llama-derived variable heavy-chain domains of heavy-chain antibody (VHH, also called Nanobodies™ were generated for the engineering of bivalent constructs, which antagonize the binding of TNF to its receptors with picomolar potencies. Three monomeric VHHs (VHH#1, VHH#2, and VHH#3 were characterized in detail and found to bind TNF with sub-nanomolar affinities. The crystal structures of the TNF–VHH complexes demonstrate that VHH#1 and VHH#2 share the same epitope, at the center of the interaction area of TNF with its TNFRs, while VHH#3 binds to a different, but partially overlapping epitope. These structures rationalize our results obtained with bivalent constructs in which two VHHs were coupled via linkers of different lengths. Contrary to conventional antibodies, these bivalent Nanobody™ constructs can bind to a single trimeric TNF, thus binding with avidity and blocking two of the three receptor binding sites in the cytokine. The different mode of binding to antigen and the engineering into bivalent constructs supports the design of highly potent VHH-based therapeutic entities.

  17. Immunoglobulin variable region sequences of two human monoclonal antibodies directed to an onco-developmental carbohydrate antigen, lactotetraosylceramide (LcOse4Cer).

    Science.gov (United States)

    Yago, K; Zenita, K; Ohwaki, I; Harada, R; Nozawa, S; Tsukazaki, K; Iwamori, M; Endo, N; Yasuda, N; Okuma, M

    1993-11-01

    A human monoclonal antibody, 11-50, was generated and was shown to recognize an onco-developmental carbohydrate antigen, LcOse4Cer. The isotype of this antibody was IgM, lambda, similar to the previously known human anti-LcOse4 antibodies, such as IgMWOO and HMST-1. We raised a murine anti-idiotypic antibody G3 (IgG1, kappa) against 11-50, and tested its reactivity towards the affinity purified human polyclonal anti-LcOse4 antibodies prepared from pooled human sera using a Gal beta 1-->3GlcNAc beta-immobilized column. The results indicated that at least a part of the human polyclonal anti-LcOse4 antibodies shared the G3 idiotype with 11-50. We further analyzed the sequence of variable regions of the two anti-LcOse4 antibodies, 11-50 and HMST-1. Sequence analysis of the heavy chain variable regions indicated that the VH regions of these two antibodies were highly homologous to each other (93.5% at the nucleic acid level), and these antibodies utilized the germline genes VH1.9III and hv3005f3 as the VH segments, which are closely related germline genes of the VHIII family. It was noted that these germline VH genes are frequently utilized in fetal B cells. The JH region of both antibodies was encoded by the JH4 gene. For the light chain, the V lambda segments of the two antibodies were 96.3% homologous to each other at the nucleic acid level. The V lambda segments of both antibodies showed the highest homology to the rearranged V lambda gene called V lambda II.DS among reported V lambda genes, while the exact germline V lambda genes encoding the two antibodies were not yet registered in available sequence databanks. The amino acid sequences of the J lambda segments of both antibodies were identical. These results indicate that the two human antibodies recognizing the onco-developmental carbohydrate antigen Lc4 are encoded by the same or very homologous germline genes.

  18. A broad set of different llama antibodies specific for a 16 kDa heat shock protein of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Anke K Trilling

    Full Text Available BACKGROUND: Recombinant antibodies are powerful tools in engineering of novel diagnostics. Due to the small size and stable nature of llama antibody domains selected antibodies can serve as a detection reagent in multiplexed and sensitive assays for M. tuberculosis. METHODOLOGY/PRINCIPAL FINDINGS: Antibodies for Mycobacterium tuberculosis (M. tb recognition were raised in Alpaca, and, by phage display, recombinant variable domains of heavy-chain antibodies (VHH binding to M. tuberculosis antigens were isolated. Two phage display selection strategies were followed: one direct selection using semi-purified protein antigen, and a depletion strategy with lysates, aiming to avoid cross-reaction to other mycobacteria. Both panning methods selected a set of binders with widely differing complementarity determining regions. Selected recombinant VHHs were produced in E. coli and shown to bind immobilized lysate in direct Enzymelinked Immunosorbent Assay (ELISA tests and soluble antigen by surface plasmon resonance (SPR analysis. All tested VHHs were specific for tuberculosis-causing mycobacteria (M. tuberculosis, M. bovis and exclusively recognized an immunodominant 16 kDa heat shock protein (hsp. The highest affinity VHH had a dissociation constant (KD of 4 × 10(-10 M. CONCLUSIONS/SIGNIFICANCE: A broad set of different llama antibodies specific for 16 kDa heat shock protein of M. tuberculosis is available. This protein is highly stable and abundant in M. tuberculosis. The VHH that detect this protein are applied in a robust SPR sensor for identification of tuberculosis-causing mycobacteria.

  19. Monoclonal antibodies for the identification and purification of vNAR domains and IgNAR immunoglobulins from the horn shark Heterodontus francisci.

    Science.gov (United States)

    Juarez, Karla; Dubberke, Gudrun; Lugo, Pavel; Koch-Nolte, Friedrich; Buck, Friedrich; Haag, Friedrich; Licea, Alexei

    2011-08-01

    In addition to conventional antibodies, cartilaginous fish have evolved a distinctive type of immunoglobulin, designated as IgNAR, which lacks the light polypeptide chains and is composed entirely by heavy chains. IgNAR molecules can be manipulated by molecular engineering to produce the variable domain of a single heavy chain polypeptide (vNARs). These, together with the VHH camel domains, constitute the smallest naturally occurring domains able to recognize an antigen. Their special features, such as small size, long extended finger-like CDR3, and thermal and chemical stability, make them suitable candidates for biotechnological purposes. Here we describe the generation of two mouse monoclonal antibodies (MAbs), MAb 370-12 and MAb 533-10, that both specifically react with vNAR domains of the horn shark Heterodontus francisci. While the former recognizes a broad spectrum of recombinant vNAR proteins, the latter is more restricted. MAb 370-12 precipitated a single band from whole shark serum, which was identified as IgNAR by mass spectrometry. Additionally, we used MAb 370-12 to follow the IgNAR-mediated immune response of sharks during immunization protocols with two different antigens (complete cells and a synthethic peptide), thus corroborating that MAb 370-12 recognizes both isolated vNAR domains and whole IgNAR molecules. Both MAbs represent an affordable molecular, biochemical, and biotechnological tool in the field of shark single-domain antibodies.

  20. Designer genes. Recombinant antibody fragments for biological imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, A.M.; Yazaki, P.J. [Beckman Research Institute of the City of Hope, Duarte, CA (United States). Dept. of Molecular Biology

    2000-09-01

    Monoclonal antibodies (MAbs), with high specificity and high affinity for their target antigens, can be utilized for delivery of agents such as radionuclides, enzymes, drugs or toxins in vivo. However, the implementation of radiolabeled antibodies as magic bullets for detection and treatment of diseases such as cancer has required addressing several shortcomings of murine MAbs. These include their immunogenicity, sub-optimal targeting and pharmacokinetic properties, and practical issues of production and radiolabeling. Genetic engineering provides a powerful approach for redesigning antibodies for use in oncologic applications in vivo. Recombinant fragments have been produced that retain high affinity for target antigens, and display a combination of rapid, high-level tumor targeting with concomitant clearance from normal tissues and the circulation in animal models. An important first step was cloning and engineering of antibody heavy and light chain variable domains into single-chain Fvs (molecular weight, 25-17 kDa), in which the variable regions are joined via a synthetic linker peptide sequence. Although scFvs themselves showed limited tumor uptake in preclinical and clinical studies, they provide a useful building block for intermediate sized recombinant fragments. Covalently linked dimers or non-covalent dimers of scFvs (also known as diabodies) show improved targeting and clearance properties due to their higher molecular weight (55kDa) and increased avidity. Further gains can be made by generation of larger recombinant fragments, such as the minibody, an scFv-C{sub H}3 fusion protein that self-assembles into a bivalent dimer of 80 kDa. A systematic evaluation of scFv, diabody, minibody, and intact antibody (based on comparison of tumor uptakes, tumor: blood activity ratios, and calculation of an Imaging Figure of Merit) can form the basis for selection of combinations of recombinant fragments and radionuclides for imaging applications. Ease of engineering

  1. Designer genes. Recombinant antibody fragments for biological imaging

    International Nuclear Information System (INIS)

    Wu, A.M.; Yazaki, P.J.

    2000-01-01

    Monoclonal antibodies (MAbs), with high specificy and high affinity for their target antigens, can be utilized for delivery of agents such as radionuclides, enzymes, drugs or toxins in vivo. However, the implementation of radiolabeled antibodies as magic bullets for detection and treatment of diseases such as cancer has required addressing several shortcomings of murine MAbs. These include their immunogenicity, sub-optimal targeting and pharmacokinetic properties, and practical issues of production and radiolabeling. Genetic engineering provides a powerful approach for redesigning antibodies for use in oncologic applications in vivo. Recombinant fragments have been produced that retain high affinity for target antigens, and display a combination of rapid, high-level tumor targeting with concomitant clearance from normal tissues and the circulation in animal models. An important first step was cloning and engineering of antibody heavy and light chain variable domains into single-chain Fvs (molecular weight, 25-17 kDa), in which the variable regions are joined via a synthetic linker peptide sequence. Although scFvs themselves showed limited tumor uptake in preclinical and clinical studies, they provide a useful building block for intermediate sized recombinant fragments. Covalently linked dimers or non-covalent dimers of scFvs (also known as diabodies) show improved targeting and clearance properties due to their higher molecular weight (55kDa) and increased avidity. Further gains can be made by generation of larger recombinant fragments, such as the minibody, an scFv-C H 3 fusion protein that self-assembles into a bivalent dimer of 80 kDa. A systematic evaluation of scFv, diabody, minibody, and intact antibody (based on comparison of tumor uptakes, tumor: blood activity ratios, and calculation of an Imaging Figure of Merit) can form the basis for selection of combinations of recombinant fragments and radionuclides for imaging applications. Ease of engineering and

  2. Preparation of the Fv fragment from a short-chain mouse IgG2a anti-dansyl monoclonal antibody and use of selectively deuterated Fv analogues for two-dimensional 1H NMR analyses fo the antigen-antibody interactions

    International Nuclear Information System (INIS)

    Takahashi, Hideo; Igarashi, Takako; Shimada, Ichio; Arata, Yoji

    1991-01-01

    The Fv fragment, a univalent antigen-binding unit with a molecular weight of 25,000, has successfully been prepared in high yield by limited proteolysis with clostripain of a short-chain mouse IgG2a anti-dansyl monoclonal antibody in which the entire C H 1 domain is deleted. The Fv fragment obtained is stable at room temperature and retains its full antigen-binding capability. It has been shown that selective deuterium labeling of the Fv fragment, which is half the size of the Fab fragment, provides 1 H NMR spectral data at a sufficient resolution for a detailed structural analysis of the antigen-combining site. NOESY spectra of an Fv analogue, in which all aromatic protons except for His C2'-H and Tyr C3',5'-H had been deuterated, were measured in the presence of varying amounts of dansyl-L-lysine. On the basis of the NOESY data obtained, it was possible to assign all the ring proton resonances for the dansly group that is bound to the Fv fragment. It was also possible to obtain information about His and Tyr residues of the Fv fragment in the absence and presence of the antigen. On the basis of the NMR data obtained, the authors have shown that at least two Tyr residues along with one of the amide groups are directly involved in antigen binding. The mode of interaction of the dansyl ring with these residues in the Fv fragment has briefly been discussed

  3. Preparation of the Fv fragment from a short-chain mouse IgG2a anti-dansyl monoclonal antibody and use of selectively deuterated Fv analogues for two-dimensional sup 1 H NMR analyses fo the antigen-antibody interactions

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hideo; Igarashi, Takako; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo (Japan))

    1991-03-19

    The Fv fragment, a univalent antigen-binding unit with a molecular weight of 25,000, has successfully been prepared in high yield by limited proteolysis with clostripain of a short-chain mouse IgG2a anti-dansyl monoclonal antibody in which the entire C{sub H}1 domain is deleted. The Fv fragment obtained is stable at room temperature and retains its full antigen-binding capability. It has been shown that selective deuterium labeling of the Fv fragment, which is half the size of the Fab fragment, provides {sup 1}H NMR spectral data at a sufficient resolution for a detailed structural analysis of the antigen-combining site. NOESY spectra of an Fv analogue, in which all aromatic protons except for His C2{prime}-H and Tyr C3{prime},5{prime}-H had been deuterated, were measured in the presence of varying amounts of dansyl-L-lysine. On the basis of the NOESY data obtained, it was possible to assign all the ring proton resonances for the dansly group that is bound to the Fv fragment. It was also possible to obtain information about His and Tyr residues of the Fv fragment in the absence and presence of the antigen. On the basis of the NMR data obtained, the authors have shown that at least two Tyr residues along with one of the amide groups are directly involved in antigen binding. The mode of interaction of the dansyl ring with these residues in the Fv fragment has briefly been discussed.

  4. Construction and expression of a functional monoclonal antibody SZ-51 specific for GMP-140 chimeric fab fragment in Escherichia coli

    International Nuclear Information System (INIS)

    Gu Jianming; Zhang Xiaomin; Xia Lijun; Wan Haiying; Liu Yue; Li Peixia; Ruan Changgeng

    1996-04-01

    The variable region cDNAs of a monoclonal antibody SZ-51 specific for α-granule membrane protein (GMP-140) on the surface of activated human platelets were spliced with the constant region cDNA of the heavy chain CH1 and light chain k of human Ig G by means of the gene recombination techniques. The above recombinant gene was amplified by the polymerase chain reaction (PCR). The expression vector of phage plasmid pHEN1 SZ-51 Fab/Hu was constructed. The pHEN1-51 Fab/Hu was introduced into non-suppressor E. coli HB2151. The amount of expression of SZ-51 chimeric Fab/Hu measured by quantitative ELISA was about 500 μg/L. Western blot demonstrated that the SZ-51 chimeric Fab fragment could specifically bind to GMP-140. (2 figs.)

  5. A three-layer immunoradiometric assay for antibodies in different immunoglobulin classes and its application to the detection of chicken thyroglobulin autoantibodies and of antibodies to sheep erythrocytes

    International Nuclear Information System (INIS)

    Carvalho, L.C.P. de; Roitt, I.M.; Wick, G.

    1980-01-01

    A versatile solid-phase assay for detection of antibodies in different immunoglobulin classes is described. The assay has been applied to: (1) the detection of IgG and IgM antithyroglobulin autoantibodies in chickens with spontaneous autoimmune thyroiditis, and (2) the detection of anti-sheep cell antibodies in normal chickens. Thyroglobulin-coated plastic tubes or formaldehyde-fixed sheep erythrocytes were used as the solid phase. Antisera were added in succession to the solid-phase antigen so as to form 3 antibody layers: (1) chicken antibody against the solid-phase antigen; (2) heavy-chain-specific rabbit anti-chicken immunoglobulin; and (3) 125 I-labelled goat anti-rabbit immunoglobulin. The assay is suitable for routine determinations on large numbers of samples; its sensitivity enables small volumes of serum to be tested and allows considerable economy in the use of valuable class-specific antisera. The radiolabelled reagent can be readily applied to other assays employing rabbit antisera. (Auth.)

  6. Increased cardiac alpha-myosin heavy chain in left atria and decreased myocardial insulin-like growth factor (Igf-I) expression accompany low heart rate in hibernating grizzly bears.

    Science.gov (United States)

    Barrows, N D; Nelson, O L; Robbins, C T; Rourke, B C

    2011-01-01

    Grizzly bears (Ursus arctos horribilis) tolerate extended periods of extremely low heart rate during hibernation without developing congestive heart failure or cardiac chamber dilation. Left ventricular atrophy and decreased left ventricular compliance have been reported in this species during hibernation. We evaluated the myocardial response to significantly reduced heart rate during hibernation by measuring relative myosin heavy-chain (MyHC) isoform expression and expression of a set of genes important to muscle plasticity and mass regulation in the left atria and left ventricles of active and hibernating bears. We supplemented these data with measurements of systolic and diastolic function via echocardiography in unanesthetized grizzly bears. Atrial strain imaging revealed decreased atrial contractility, decreased expansion/reservoir function (increased atrial stiffness), and decreased passive-filling function (increased ventricular stiffness) in hibernating bears. Relative MyHC-α protein expression increased significantly in the atrium during hibernation. The left ventricle expressed 100% MyHC-β protein in both groups. Insulin-like growth factor (IGF-I) mRNA expression was reduced by ∼50% in both chambers during hibernation, consistent with the ventricular atrophy observed in these bears. Interestingly, mRNA expression of the atrophy-related ubiquitin ligases Muscle Atrophy F-box (MAFBx) and Muscle Ring Finger 1 did not increase, nor did expression of myostatin or hypoxia-inducible factor 1α (HIF-1α). We report atrium-specific decreases of 40% and 50%, respectively, in MAFBx and creatine kinase mRNA expression during hibernation. Decreased creatine kinase expression is consistent with lowered energy requirements and could relate to reduced atrial emptying function during hibernation. Taken together with our hemodynamic assessment, these data suggest a potential downregulation of atrial chamber function during hibernation to prevent fatigue and dilation

  7. Proportions of myosin heavy chain mRNAs, protein isoforms and fiber types in the slow and fast skeletal muscles are maintained after alterations of thyroid status in rats.

    Science.gov (United States)

    Soukup, T; Diallo, M

    2015-01-01

    Recently, we have established that slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles of euthyroid (EU) Lewis rats posses the same proportions between their four myosin heavy chain (MyHC) mRNAs, protein isoforms and fiber types as determined by real time RT-PCR, SDS-PAGE and 2-D stereological fiber type analysis, respectively. In the present paper we investigated if these proportions are maintained in adult Lewis rats with hyperthyroid (HT) and hypothyroid (HY) status. Although HT and HY states change MyHC isoform expression, results from all three methods showed that proportion between MyHC mRNA-1, 2a, -2x/d, -2b, protein isoforms MyHC-1, -2a, -2x/d, -2b and to lesser extent also fiber types 1, 2A, 2X/D, 2B were preserved in both SOL and EDL muscles. Furthermore, in the SOL muscle mRNA expression of slow MyHC-1 remained up to three orders higher compared to fast MyHC transcripts, which explains the predominance of MyHC-1 isoform and fiber type 1 even in HT rats. Although HT status led in the SOL to increased expression of MyHC-2a mRNA, MyHC-2a isoform and 2A fibers, it preserved extremely low expression of MyHC-2x and -2b mRNA and protein isoforms, which explains the absence of pure 2X/D and 2B fibers. HY status, on the other hand, almost completely abolished expression of all three fast MyHC mRNAs, MyHC protein isoforms and fast fiber types in the SOL muscle. Our data present evidence that a correlation between mRNA, protein content and fiber type composition found in EU status is also preserved in HT and HY rats.

  8. Stimulatory and inhibitory mechanisms of slow muscle-specific myosin heavy chain gene expression in fish: Transient and transgenic analysis of torafugu MYHM86-2 promoter in zebrafish embryos

    International Nuclear Information System (INIS)

    Asaduzzaman, Md.; Kinoshita, Shigeharu; Bhuiyan, Sharmin Siddique; Asakawa, Shuichi; Watabe, Shugo

    2013-01-01

    The myosin heavy chain gene, MYH M86-2 , exhibited restricted expression in slow muscle fibers of torafugu embryos and larvae, suggesting its functional roles for embryonic and larval muscle development. However, the transcriptional mechanisms involved in its expression are still ambiguous. The present study is the first extensive analysis of slow muscle-specific MYH M86-2 promoter in fish for identifying the cis-elements that are crucial for its expression. Combining both transient transfection and transgenic approaches, we demonstrated that the 2614 bp 5′-flanking sequences of MYH M86-2 contain a sufficient promoter activity to drive gene expression specific to superficial slow muscle fibers. By cyclopamine treatment, we also demonstrated that the differentiation of such superficial slow muscle fibers depends on hedgehog signaling activity. The deletion analyses defined an upstream fragment necessary for repressing ectopic MYH M86-2 expression in the fast muscle fibers. The transcriptional mechanism that prevents MYH M86-2 expression in the fast muscle fibers is mediated through Sox6 binding elements. We also demonstrated that Sox6 may function as a transcriptional repressor of MYH M86-2 expression. We further discovered that nuclear factor of activated T cells (NFAT) binding elements plays a key role and myocyte enhancer factor-2 (MEF2) binding elements participate in the transcriptional regulation of MYH M86-2 expression. - Highlights: ► MYH M86-2 is highly expressed in slow muscle fibers of torafugu embryos and larvae. ► MYH M86-2 promoter activity depends on the hedgehog signaling. ► Sox6 binding elements inhibits MYH M86-2 expression in fast muscle fibers. ► Sox6 elements function as transcriptional repressor of MYH M86-2 promoter activity. ► NFAT and MEF2 binding elements play a key role for directing MYH M86-2 expression

  9. A Novel Alpha Cardiac Actin (ACTC1 Mutation Mapping to a Domain in Close Contact with Myosin Heavy Chain Leads to a Variety of Congenital Heart Defects, Arrhythmia and Possibly Midline Defects.

    Directory of Open Access Journals (Sweden)

    Céline Augière

    Full Text Available A Lebanese Maronite family presented with 13 relatives affected by various congenital heart defects (mainly atrial septal defects, conduction tissue anomalies and midline defects. No mutations were found in GATA4 and NKX2-5.A set of 399 poly(AC markers was used to perform a linkage analysis which peaked at a 2.98 lod score on the long arm of chromosome 15. The haplotype analysis delineated a 7.7 meganucleotides genomic interval which included the alpha-cardiac actin gene (ACTC1 among 36 other protein coding genes. A heterozygous missense mutation was found (c.251T>C, p.(Met84Thr in the ACTC1 gene which changed a methionine residue conserved up to yeast. This mutation was absent from 1000 genomes and exome variant server database but segregated perfectly in this family with the affection status. This mutation and 2 other ACTC1 mutations (p.(Glu101Lys and p.(Met125Val which result also in congenital heart defects are located in a region in close apposition to a myosin heavy chain head region by contrast to 3 other alpha-cardiac actin mutations (p.(Ala297Ser,p.(Asp313His and p.(Arg314His which result in diverse cardiomyopathies and are located in a totally different interaction surface.Alpha-cardiac actin mutations lead to congenital heart defects, cardiomyopathies and eventually midline defects. The consequence of an ACTC1 mutation may in part be dependent on the interaction surface between actin and myosin.

  10. A new and rapid method for immunoglobulin class and subclass determination of mouse monoclonal antibodies using a solid-phase immunoradiometric assay

    International Nuclear Information System (INIS)

    Storch, M.-J.; Lohmann-Matthes, M.-L.

    1984-01-01

    A solid-phase immunoradiometric assay is described for the detection of mouse immunoglobulin classes and subclasses in unpurified and unconcentrated supernatants of hybridomas. IgG fractions from rabbit antisera specific for mouse immunoglobulin classes and subclasses are used for coating the wells of flexible microtiter plates. Monoclonal antibody present in hybridoma supernatants is bound only to wells that contain the appropriate anti-subclass antibody. The binding of hybridoma antibodies to corresponding IgG subclasses or IgM is then detected by a labeled rabbit anti-mouse antibody binding to all mouse immunoglobulins (heavy and light chains). Thus, only 1 labeled antibody is needed for all assays. The advantages of the method described are the following: results are obtained within a few hours and antibody containing hybridoma supernatants may be used without a concentration step since minute amounts of antibody are detected by the immunoradiometric assay. Cultures producing several subclasses may be early recognized as oligo/polyclonal. (Auth.)

  11. Isolation of Osteosarcoma-Associated Human Antibodies from a Combinatorial Fab Phage Display Library

    Directory of Open Access Journals (Sweden)

    Carmela Dantas-Barbosa

    2009-01-01

    Full Text Available Osteosarcoma, a highly malignant disease, is the most common primary bone tumor and is frequently found in children and adolescents. In order to isolate antibodies against osteosarcoma antigens, a combinatorial osteosarcoma Fab library displayed on the surface of phages was used. After three rounds of selection on the surface of tumor cells, several osteosarcoma-reactive Fabs were detected. From these Fabs, five were better characterized, and despite having differences in their VH (heavy chain variable domain and Vκ (kappa chain variable domain regions, they all bound to a protein with the same molecular mass. Further analysis by cell ELISA and immunocytochemistry suggested that the Fabs recognize a membrane-associated tumor antigen expressed in higher amounts in neoplasic cells than in normal tissue. These results suggest that the human Fabs selected in this work are a valuable tool for the study of this neoplasia.

  12. Production and characterisation of a neutralising chimeric antibody against botulinum neurotoxin A.

    Directory of Open Access Journals (Sweden)

    Julie Prigent

    Full Text Available Botulinum neurotoxins, produced by Clostridium botulinum bacteria, are the causative agent of botulism. This disease only affects a few hundred people each year, thus ranking it among the orphan diseases. However, botulinum toxin type A (BoNT/A is the most potent toxin known to man. Due to their potency and ease of production, these toxins were classified by the Centers for Disease Control and Prevention (CDC as Category A biothreat agents. For several biothreat agents, like BoNT/A, passive immunotherapy remains the only possible effective treatment allowing in vivo neutralization, despite possible major side effects. Recently, several mouse monoclonal antibodies directed against a recombinant fragment of BoNT/A were produced in our laboratory and most efficiently neutralised the neurotoxin. In the present work, the most powerful one, TA12, was selected for chimerisation. The variable regions of this antibody were thus cloned and fused with the constant counterparts of human IgG1 (kappa light and gamma 1 heavy chains. Chimeric antibody production was evaluated in mammalian myeloma cells (SP2/0-Ag14 and insect cells (Sf9. After purifying the recombinant antibody by affinity chromatography, the biochemical properties of chimeric and mouse antibody were compared. Both have the same very low affinity constant (close to 10 pM and the chimeric antibody exhibited a similar capacity to its parent counterpart in neutralising the toxin in vivo. Its strong affinity and high neutralising potency make this chimeric antibody interesting for immunotherapy treatment in humans in cases of poisoning, particularly as there is a probable limitation of the immunological side effects observed with classical polyclonal antisera from heterologous species.

  13. Catalytic Antibodies

    Indian Academy of Sciences (India)

    biological processes and is intended to catalyze a reaction for which no real enzyme is ... the reaction. In order to enhance the rates of chemical reactions, enzymes, ..... of such antibodies has already been exploited in the production of a biosensor. ..... tant to the pharmaceutical and fine chemical industries for the synthesis ...

  14. A recombinant, fully human monoclonal antibody with antitumor activity constructed from phage-displayed antibody fragments

    NARCIS (Netherlands)

    Huls, GA; Heijnen, IAFM; Cuomo, ME; Koningsberger, JC; Boel, E; de Vries, ARV; Loyson, SAJ; Helfrich, W; Henegouwen, GPV; van Meijer, M; de Kruif, J; Logtenberg, T

    A single-chain Fv antibody fragment specific for the tumor-associated Ep-CAM molecule was isolated from a semisynthetic phage display library and converted into an intact, fully human IgG1 monoclonal antibody (huMab), The purified huMab had an affinity of 5 nM and effectively mediated tumor cell

  15. Neutralisation of HIV-1 cell-cell spread by human and llama antibodies.

    Science.gov (United States)

    McCoy, Laura E; Groppelli, Elisabetta; Blanchetot, Christophe; de Haard, Hans; Verrips, Theo; Rutten, Lucy; Weiss, Robin A; Jolly, Clare

    2014-10-02

    Direct cell-cell spread of HIV-1 is a very efficient mode of viral dissemination, with increasing evidence suggesting that it may pose a considerable challenge to controlling viral replication in vivo. Much current vaccine research involves the study of broadly neutralising antibodies (bNabs) that arise during natural infection with the aims of eliciting such antibodies by vaccination or incorporating them into novel therapeutics. However, whether cell-cell spread of HIV-1 can be effectively targeted by bNabs remains unclear, and there is much interest in identifying antibodies capable of efficiently neutralising virus transmitted by cell-cell contact. In this study we have tested a panel of bNAbs for inhibition of cell-cell spread, including some not previously evaluated for inhibition of this mode of HIV-1 transmission. We found that three CD4 binding site antibodies, one from an immunised llama (J3) and two isolated from HIV-1-positive patients (VRC01 and HJ16) neutralised cell-cell spread between T cells, while antibodies specific for glycan moieties (2G12, PG9, PG16) and the MPER (2F5) displayed variable efficacy. Notably, while J3 displayed a high level of potency during cell-cell spread we found that the small size of the llama heavy chain-only variable region (VHH) J3 is not required for efficient neutralisation since recombinant J3 containing a full-length human heavy chain Fc domain was significantly more potent. J3 and J3-Fc also neutralised cell-cell spread of HIV-1 from primary macrophages to CD4+ T cells. In conclusion, while bNabs display variable efficacy at preventing cell-cell spread of HIV-1, we find that some CD4 binding site antibodies can inhibit this mode of HIV-1 dissemination and identify the recently described llama antibody J3 as a particularly potent inhibitor. Effective neutralisation of cell-cell spread between physiologically relevant cell types by J3 and J3-Fc supports the development of VHH J3 nanobodies for therapeutic or

  16. Heavy baryons

    International Nuclear Information System (INIS)

    Koerner, J.G.

    1994-06-01

    We review the experimental and theoretical status of baryons containing one heavy quark. The charm and bottom baryon states are classified and their mass spectra are listed. The appropriate theoretical framework for the description of heavy baryons is the Heavy Quark Effective Theory, whose general ideas and methods are introduced and illustrated in specific examples. We present simple covariant expressions for the spin wave functions of heavy baryons including p-wave baryons. The covariant spin wave functions are used to determine the Heavy Quark Symmetry structure of flavour-changing current-induced transitions between heavy baryons as well as one-pion and one-photon transitions between heavy baryons of the same flavour. We discuss 1/m Q corrections to the current-induced transitions as well as the structure of heavy to light baryon transitions. Whenever possible we attempt to present numbers to compare with experiment by making use of further model-dependent assumptions as e.g. the constituent picture for light quarks. We highlight recent advances in the theoretical understanding of the inclusive decays of hadrons containing one heavy quark including polarization. For exclusive semileptonic decays we discuss rates, angular decay distributions and polarization effects. We provide an update of the experimental and theoretical status of lifetimes of heavy baryons and of exclusive nonleptonic two body decays of charm baryons. (orig.)

  17. An unusual cysteine VL87 affects the antibody fragment conformations without interfering with the disulfide bond formation.

    Science.gov (United States)

    Attallah, Carolina; Aguilar, María Fernanda; Garay, A Sergio; Herrera, Fernando E; Etcheverrigaray, Marina; Oggero, Marcos; Rodrigues, Daniel E

    2017-10-01

    The Cys residues are almost perfectly conserved in all antibodies. They contribute significantly to the antibody fragment stability. The relevance of two natural contiguous Cys residues of an anti-recombinant human-follicle stimulation hormone (rhFSH) in a format of single-chain variable fragment (scFv) was studied. This scFv contains 5 Cys residues: V H 22 and V H 92 in the variable heavy chain (V H ) and V L 23, V L 87 and V L 88 in the variable light chain (V L ). The influence of two unusual contiguous Cys at positions V L 87 and V L 88 was studied by considering the wild type fragment and mutant variants: V L -C88S, V L -C87S, V L -C87Y. The analysis was carried out using antigen-binding ability measurement by indirect specific ELISA and a detailed molecular modeling that comprises homology methods, long molecular dynamics simulations and docking. We found that V L -C87 affected the antibody fragment stability without interfering with the disulfide bond formation. The effect of mutating the V L -C87 by a usual residue at this position like Tyr caused distant structural changes at the V H region that confers a higher mobility to the V H -CDR2 and V H -CDR3 loops improving the scFv binding to the antigen. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Missing Links in Antibody Assembly Control

    Directory of Open Access Journals (Sweden)

    Tiziana Anelli

    2013-01-01

    Full Text Available Fidelity of the humoral immune response requires that quiescent B lymphocytes display membrane bound immunoglobulin M (IgM on B lymphocytes surface as part of the B cell receptor, whose function is to recognize an antigen. At the same time B lymphocytes should not secrete IgM until recognition of the antigen has occurred. The heavy chains of the secretory IgM have a C-terminal tail with a cysteine instead of a membrane anchor, which serves to covalently link the IgM subunits by disulfide bonds to form “pentamers” or “hexamers.” By virtue of the same cysteine, unassembled secretory IgM subunits are recognized and retained (via mixed disulfide bonds by members of the protein disulfide isomerase family, in particular ERp44. This so-called “thiol-mediated retention” bars assembly intermediates from prematurely leaving the cell and thereby exerts quality control on the humoral immune response. In this essay we discuss recent findings on how ERp44 governs such assembly control in a pH-dependent manner, shuttling between the cisGolgi and endoplasmic reticulum, and finally on how pERp1/MZB1, possibly as a co-chaperone of GRP94, may help to overrule the thiol-mediated retention in the activated B cell to give way to antibody secretion.

  19. Assay for the specificity of monoclonal antibodies in crossed immunoelectrophoresis

    DEFF Research Database (Denmark)

    Skjødt, K; Schou, C; Koch, C

    1984-01-01

    A method is described based on crossed immunoelectrophoresis of a complex antigen mixture in agarose gel followed by incubation of the gel with the monoclonal antibody. The bound monoclonal antibody is detected by the use of a secondary enzyme-labelled antibody. Using this technique we have been ...... I molecules. In other experiments using the same technique we demonstrated the reaction of a monoclonal antibody specific for chicken Ig light chains. Udgivelsesdato: 1984-Aug-3...

  20. Falling chains

    OpenAIRE

    Wong, Chun Wa; Yasui, Kosuke

    2005-01-01

    The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is inco...