WorldWideScience

Sample records for llama antibody fragments

  1. 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

  2. Isolation of llama antibody fragments for prevention of dandruff by phage display in shampoo

    NARCIS (Netherlands)

    Dolk, E.; Vaart, M. van der; Lutje Hulsik, D.; Vriend, G.; Haard, H. de; Spinelli, S.; Cambillau, C.; Frenken, L.; Verrips, T.

    As part of research exploring the feasibility of using antibody fragments to inhibit the growth of organisms implicated in dandruff, we isolated antibody fragments that bind to a cell surface protein of Malassezia furfur in the presence of shampoo. We found that phage display of llama

  3. 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

  4. 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

  5. Improved functional immobilization of llama single-domain antibody fragments to polystyrene surfaces using small peptides

    NARCIS (Netherlands)

    Harmsen, M.M.; Fijten, H.P.D.

    2012-01-01

    We studied the effect of different fusion domains on the functional immobilization of three llama single-domain antibody fragments (VHHs) after passive adsorption to polystyrene in enzyme-linked immunosorbent assays (ELISA). Three VHHs produced without any fusion domain were efficiently adsorbed to

  6. Stimulation of chymosin secretion by simultaneous expression with chymosin-binding llama single-domain antibody fragments in yeast

    NARCIS (Netherlands)

    Harmsen, M.M.; Smits, C.B.; Geus, de B.

    2002-01-01

    We studied the effect of coexpression of chymosin and chymosin-binding llama single-domain antibody fragments (VHHs) on the secretion of chymosin by Saccharomyces cerevisiae cells. A VHH expression library containing chymosin-specific VHHs was obtained by immunization of a llama and coexpressed with

  7. 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

  8. Prolonged in vivo residence times of llama single-domain antibody fragments in pigs by binding to porcine immunoglobulins

    NARCIS (Netherlands)

    Harmsen, M.M.; Solt, van C.B.; Fijten, H.P.D.; Setten, van M.C.

    2005-01-01

    The therapeutic parenteral application of llama single-domain antibody fragments (VHHs) is hampered by their small size, resulting in a fast elimination from the body. Here we describe a method to increase the serum half-life of VHHs in pigs by fusion to another VHH binding to porcine immunoglobulin

  9. 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.

  10. Isolation of Panels of Llama Single-Domain Antibody Fragments Binding All Nine Neuraminidase Subtypes of Influenza A Virus

    Directory of Open Access Journals (Sweden)

    Guus Koch

    2013-04-01

    Full Text Available Avian influenza A virus comprises sixteen hemagglutinin (HA and nine neuraminidase (NA subtypes (N1–N9. To isolate llama single-domain antibody fragments (VHHs against all N subtypes, four llamas were immunized with mixtures of influenza viruses. Selections using influenza virus yielded predominantly VHHs binding to the highly immunogenic HA and nucleoprotein. However, selection using enzymatically active recombinant NA (rNA protein enabled us to isolate NA binding VHHs. Some isolated VHHs cross-reacted to other N subtypes. These were subsequently used for the capture of N subtypes that could not be produced as recombinant protein (rN6 or were enzymatically inactive (rN1, rN5 in phage display selection, yielding novel VHHs. In total we isolated 188 NA binding VHHs, 64 of which were expressed in yeast. Most VHHs specifically recognize a single N subtype, but some VHHs cross-react with other N-subtypes. At least one VHH bound to all N subtypes, except N4, identifying a conserved antigenic site. Thus, this work (1 describes methods for isolating NA binding VHHs, (2 illustrates the suitability of llama immunization with multiple antigens for retrieving many binders against different antigens and (3 describes 64 novel NA binding VHHs, including a broadly reactive VHH, which can be used in various assays for influenza virus subtyping, detection or serology.

  11. 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

  12. 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

  13. Passive immunization of guinea-pigs with llama single-domain antibody fragments against foot-and-mouth disease

    NARCIS (Netherlands)

    Harmsen, M.M.; Solt, van C.B.; Fijten, H.P.D.; Keulen, van L.; Rosalia, R.A.; Weerdmeester, K.; Cornelissen, A.H.M.; Bruin, de M.G.M.; Eble, P.L.; Dekker, A.

    2007-01-01

    Foot-and-mouth disease (FMD) is a highly contagious disease that occasionally causes outbreaks in Europe. There is a need for therapies that provide rapid protection against FMD in outbreak situations. We aim to provide such rapid protection by passive immunization with llama single-domain antibody

  14. 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.

  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. 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. In vitro neutralisation of rotavirus infection by two broadly specific recombinant monovalent llama-derived antibody fragments

    NARCIS (Netherlands)

    F. Aladin (Farah); A.W.C. Einerhand (Sandra); J. Bouma (Janneke); S. Bezemer (Sandra); P. Hermans (Pim); D. Wolvers (Danielle); K. Bellamy (Kate); L.G.J. Frenken (Leon); J. Gray (Jim); M. Iturriza-Gómara (Miren)

    2012-01-01

    textabstractRotavirus is the main cause of viral gastroenteritis in young children. Therefore, the development of inexpensive antiviral products for the prevention and/or treatment of rotavirus disease remains a priority. Previously we have shown that a recombinant monovalent antibody fragment

  18. Passive immunization of pigs with bispecific llama single-domain antibody fragments against foot-and-mouth disease and porcine immunoglobulin

    NARCIS (Netherlands)

    Harmsen, M.M.; Fijten, H.P.D.; Dekker, A.; Eble, P.L.

    2008-01-01

    Foot-and-mouth disease (FMD) is a contagious viral disease of cloven-hoofed animals that occasionally causes outbreaks in Europe. We aim to develop an immunotherapy that confers rapid protection against FMD in outbreak situations. For this purpose, we previously isolated llama single-domain antibody

  19. Llama Antibody Fragments Recognizing Various Epitopes of the CD4bs Neutralize a Broad Range of HIV-1 Subtypes A, B and C

    Science.gov (United States)

    Aasa-Chapman, Marlèn; Gorlani, Andrea; Forsman Quigley, Anna; Hulsik, David Lutje; Chen, Lei; Weiss, Robin; de Haard, Hans; Verrips, Theo

    2012-01-01

    Many of the neutralising antibodies, isolated to date, display limited activities against the globally most prevalent HIV-1 subtypes A and C. Therefore, those subtypes are considered to be an important target for antibody-based therapy. Variable domains of llama heavy chain antibodies (VHH) have some superior properties compared with classical antibodies. Therefore we describe the application of trimeric forms of envelope proteins (Env), derived from HIV-1 of subtype A and B/C, for a prolonged immunization of two llamas. A panel of VHH, which interfere with CD4 binding to HIV-1 Env were selected with use of panning. The results of binding and competition assays to various Env, including a variant with a stabilized CD4-binding state (gp120Ds2), cross-competition experiments, maturation analysis and neutralisation assays, enabled us to classify the selected VHH into three groups. The VHH of group I were efficient mainly against viruses of subtype A, C and B′/C. The VHH of group II resemble the broadly neutralising antibody (bnmAb) b12, neutralizing mainly subtype B and C viruses, however some had a broader neutralisation profile. A representative of the third group, 2E7, had an even higher neutralization breadth, neutralizing 21 out of the 26 tested strains belonging to the A, A/G, B, B/C and C subtypes. To evaluate the contribution of certain amino acids to the potency of the VHH a small set of the mutants were constructed. Surprisingly this yielded one mutant with slightly improved neutralisation potency against 92UG37.A9 (subtype A) and 96ZM651.02 (subtype C). These findings and the well-known stability of VHH indicate the potential application of these VHH as anti-HIV-1 microbicides. PMID:22438910

  20. 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.

  1. Recombinant monovalent llama-derived antibody fragments (VHH to rotavirus VP6 protect neonatal gnotobiotic piglets against human rotavirus-induced diarrhea.

    Directory of Open Access Journals (Sweden)

    Celina G Vega

    Full Text Available Group A Rotavirus (RVA is the leading cause of severe diarrhea in children. The aims of the present study were to determine the neutralizing activity of VP6-specific llama-derived single domain nanoantibodies (VHH nanoAbs against different RVA strains in vitro and to evaluate the ability of G6P[1] VP6-specific llama-derived single domain nanoantibodies (VHH to protect against human rotavirus in gnotobiotic (Gn piglets experimentally inoculated with virulent Wa G1P[8] rotavirus. Supplementation of the daily milk diet with 3B2 VHH clone produced using a baculovirus vector expression system (final ELISA antibody -Ab- titer of 4096; virus neutralization -VN- titer of 256 for 9 days conferred full protection against rotavirus associated diarrhea and significantly reduced virus shedding. The administration of comparable levels of porcine IgG Abs only protected 4 out of 6 of the animals from human RVA diarrhea but significantly reduced virus shedding. In contrast, G6P[1]-VP6 rotavirus-specific IgY Abs purified from eggs of hyperimmunized hens failed to protect piglets against human RVA-induced diarrhea or virus shedding when administering similar quantities of Abs. The oral administration of VHH nanoAb neither interfered with the host's isotype profiles of the Ab secreting cell responses to rotavirus, nor induced detectable host Ab responses to the treatment in serum or intestinal contents. This study shows that the oral administration of rotavirus VP6-VHH nanoAb is a broadly reactive and effective treatment against rotavirus-induced diarrhea in neonatal pigs. Our findings highlight the potential value of a broad neutralizing VP6-specific VHH nanoAb as a treatment that can complement or be used as an alternative to the current strain-specific RVA vaccines. Nanobodies could also be scaled-up to develop pediatric medication or functional food like infant milk formulas that might help treat RVA diarrhea.

  2. Recombinant monovalent llama-derived antibody fragments (VHH) to rotavirus VP6 protect neonatal gnotobiotic piglets against human rotavirus-induced diarrhea.

    Science.gov (United States)

    Vega, Celina G; Bok, Marina; Vlasova, Anastasia N; Chattha, Kuldeep S; Gómez-Sebastián, Silvia; Nuñez, Carmen; Alvarado, Carmen; Lasa, Rodrigo; Escribano, José M; Garaicoechea, Lorena L; Fernandez, Fernando; Bok, Karin; Wigdorovitz, Andrés; Saif, Linda J; Parreño, Viviana

    2013-01-01

    Group A Rotavirus (RVA) is the leading cause of severe diarrhea in children. The aims of the present study were to determine the neutralizing activity of VP6-specific llama-derived single domain nanoantibodies (VHH nanoAbs) against different RVA strains in vitro and to evaluate the ability of G6P[1] VP6-specific llama-derived single domain nanoantibodies (VHH) to protect against human rotavirus in gnotobiotic (Gn) piglets experimentally inoculated with virulent Wa G1P[8] rotavirus. Supplementation of the daily milk diet with 3B2 VHH clone produced using a baculovirus vector expression system (final ELISA antibody -Ab- titer of 4096; virus neutralization -VN- titer of 256) for 9 days conferred full protection against rotavirus associated diarrhea and significantly reduced virus shedding. The administration of comparable levels of porcine IgG Abs only protected 4 out of 6 of the animals from human RVA diarrhea but significantly reduced virus shedding. In contrast, G6P[1]-VP6 rotavirus-specific IgY Abs purified from eggs of hyperimmunized hens failed to protect piglets against human RVA-induced diarrhea or virus shedding when administering similar quantities of Abs. The oral administration of VHH nanoAb neither interfered with the host's isotype profiles of the Ab secreting cell responses to rotavirus, nor induced detectable host Ab responses to the treatment in serum or intestinal contents. This study shows that the oral administration of rotavirus VP6-VHH nanoAb is a broadly reactive and effective treatment against rotavirus-induced diarrhea in neonatal pigs. Our findings highlight the potential value of a broad neutralizing VP6-specific VHH nanoAb as a treatment that can complement or be used as an alternative to the current strain-specific RVA vaccines. Nanobodies could also be scaled-up to develop pediatric medication or functional food like infant milk formulas that might help treat RVA diarrhea.

  3. An Exopolysaccharide-Deficient Mutant of Lactobacillus rhamnosus GG Efficiently Displays a Protective Llama Antibody Fragment against Rotavirus on Its Surface.

    Science.gov (United States)

    Álvarez, Beatriz; Krogh-Andersen, Kasper; Tellgren-Roth, Christian; Martínez, Noelia; Günaydın, Gökçe; Lin, Yin; Martín, M Cruz; Álvarez, Miguel A; Hammarström, Lennart; Marcotte, Harold

    2015-09-01

    Rotavirus is the leading cause of infantile diarrhea in developing countries, where it causes a high number of deaths among infants. Two vaccines are available, being highly effective in developed countries although markedly less efficient in developing countries. As a complementary treatment to the vaccines, a Lactobacillus strain producing an anti-rotavirus antibody fragment in the gastrointestinal tract could potentially be used. In order to develop such an alternative therapy, the effectiveness of Lactobacillus rhamnosus GG to produce and display a VHH antibody fragment (referred to as anti-rotavirus protein 1 [ARP1]) on the surface was investigated. L. rhamnosus GG is one of the best-characterized probiotic bacteria and has intrinsic antirotavirus activity. Among four L. rhamnosus GG strains [GG (CMC), GG (ATCC 53103), GG (NCC 3003), and GG (UT)] originating from different sources, only GG (UT) was able to display ARP1 on the bacterial surface. The genomic analysis of strain GG (UT) showed that the genes welE and welF of the EPS cluster are inactivated, which causes a defect in exopolysaccharide (EPS) production, allowing efficient display of ARP1 on its surface. Finally, GG (UT) seemed to confer a level of protection against rotavirus-induced diarrhea similar to that of wild-type GG (NCC 3003) in a mouse pup model, indicating that the EPS may not be involved in the intrinsic antirotavirus activity. Most important, GG (EM233), a derivative of GG (UT) producing ARP1, was significantly more protective than the control strain L. casei BL23. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. 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

  5. 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.

  6. A broad set of different llama antibodies specific for a 16 kDa heat shock protein of Mycobacterium tuberculosis

    NARCIS (Netherlands)

    Trilling, Anke K.; de Ronde, Hans; Noteboom, Linda; van Houwelingen, Adèle; Roelse, Margriet; Srivastava, Saurabh K.; Haasnoot, Willem; Jongsma, Maarten A.; Kolk, Arend; Zuilhof, Han; Beekwilder, Jules

    2011-01-01

    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. Antibodies for Mycobacterium tuberculosis (M.

  7. In Vivo Neutralization of α-Cobratoxin with High-Affinity Llama Single-Domain Antibodies (VHHs) and a VHH-Fc Antibody

    Science.gov (United States)

    Richard, Gabrielle; Meyers, Ashley J.; McLean, Michael D.; Arbabi-Ghahroudi, Mehdi; MacKenzie, Roger; Hall, J. Christopher

    2013-01-01

    Small recombinant antibody fragments (e.g. scFvs and VHHs), which are highly tissue permeable, are being investigated for antivenom production as conventional antivenoms consisting of IgG or F(ab’)2 antibody fragments do not effectively neutralize venom toxins located in deep tissues. However, antivenoms composed entirely of small antibody fragments may have poor therapeutic efficacy due to their short serum half-lives. To increase serum persistence and maintain tissue penetration, we prepared low and high molecular mass antivenom antibodies. Four llama VHHs were isolated from an immune VHH-displayed phage library and were shown to have high affinity, in the low nM range, for α-cobratoxin (α–Cbtx), the most lethal component of Naja kaouthia venom. Subsequently, our highest affinity VHH (C2) was fused to a human Fc fragment to create a VHH2-Fc antibody that would offer prolonged serum persistence. After in planta (Nicotiana benthamiana) expression and purification, we show that our VHH2-Fc antibody retained high affinity binding to α–Cbtx. Mouse α–Cbtx challenge studies showed that our highest affinity VHHs (C2 and C20) and the VHH2-Fc antibody effectively neutralized lethality induced by α–Cbtx at an antibody:toxin molar ratio as low as ca. 0.75×:1. Further research towards the development of an antivenom therapeutic involving these anti-α-Cbtx VHHs and VHH2-Fc antibody molecules should involve testing them as a combination, to determine whether they maintain tissue penetration capability and low immunogenicity, and whether they exhibit improved serum persistence and therapeutic efficacy. PMID:23894495

  8. 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.

  9. Middle East respiratory syndrome coronavirus specific antibodies in naturally exposed Israeli llamas, alpacas and camels

    Directory of Open Access Journals (Sweden)

    Dan David

    2018-06-01

    Full Text Available Thus far, no human MERS-CoV infections have been reported from Israel. Evidence for the circulation of MERS-CoV in dromedaries has been reported from almost all the countries of the Middle East, except Israel. Therefore, we aimed to analyze MERS-CoV infection in Israeli camelids, sampled between 2012 and 2017. A total of 411 camels, 102 alpacas and 19 llamas' sera were tested for the presence of antibodies to MERS-CoV. Our findings indicate a lower MERS-CoV seropositivity among Israeli dromedaries than in the surrounding countries, and for the first time naturally infected llamas were identified. In addition, nasal swabs of 661 camels, alpacas and lamas, obtained from January 2015 to December 2017, were tested for the presence of MERS-CoV RNA. All nasal swabs were negative, indicating no evidence for MERS-CoV active circulation in these camelids during that time period. Keywords: MERS coronavirus, Antibodies, Israel, Dromedary camels, Llamas, Alpacas

  10. Refolding Technologies for Antibody Fragments

    Directory of Open Access Journals (Sweden)

    Tsutomu Arakawa

    2014-05-01

    Full Text Available Refolding is one of the production technologies for pharmaceutical grade antibody fragments. Detergents and denaturants are primarily used to solubilize the insoluble proteins. The solubilized and denatured proteins are refolded by reducing the concentration of the denaturants or detergents. Several refolding technologies have been used for antibody fragments, comprising dilution, dialysis, solid phase solvent exchange and size exclusion chromatography, as reviewed here. Aggregation suppressor or folding-assisting agents, including arginine hydrochloride, ionic liquids and detergents or denaturants at low concentrations, are included in the refolding solvent to enhance refolding yield.

  11.  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.

  12. Escherichia coli F4 fimbriae specific lama single-domain antibody fragments effectively inhibit bacterial adhesion in vitro but poorly protect against diarrhea

    NARCIS (Netherlands)

    Harmsen, M.M.; Solt, van C.B.; Hoogendoorn, A.; Zijderveld, van F.G.; Niewold, T.A.; Meulen, van der J.

    2005-01-01

    Oral administration of polyclonal antibodies directed against enterotoxigenic Escherichia coli (ETEC) F4 fimbriae is used to protect against piglet post-weaning diarrhoea. For cost reasons, we aim to replace these polyclonal antibodies by recombinant llama single-domain antibody fragments (VHHs)

  13. A novel llama antibody targeting Fn14 exhibits anti-metastatic activity in vivo.

    Science.gov (United States)

    Trebing, Johannes; Lang, Isabell; Chopra, Martin; Salzmann, Steffen; Moshir, Mahan; Silence, Karen; Riedel, Simone S; Siegmund, Daniela; Beilhack, Andreas; Otto, Christoph; Wajant, Harald

    2014-01-01

    Expression of fibroblast growth factor (FGF)-inducible 14 (Fn14), a member of the tumor necrosis factor receptor superfamily, is typically low in healthy adult organisms, but strong Fn14 expression is induced in tissue injury and tissue remodeling. High Fn14 expression is also observed in solid tumors, which is why this receptor is under consideration as a therapeutic target in oncology. Here, we describe various novel mouse-human cross-reactive llama-derived recombinant Fn14-specific antibodies (5B6, 18D1, 4G5) harboring the human IgG1 Fc domain. In contrast to recombinant variants of the established Fn14-specific antibodies PDL192 and P4A8, all three llama-derived antibodies efficiently bound to the W42A and R56P mutants of human Fn14. 18D1 and 4G5, but not 5B6, efficiently blocked TNF-like weak inducer of apoptosis(TWEA K) binding at low concentrations (0.2–2 μg/ml). Oligomerization and Fcγ receptor (FcγR) binding converted all antibodies into strong Fn14 agonists. Variants of 18D1 with enhanced and reduced antibody-dependent cell-mediated cytotoxicity (ADCC) activity were further analyzed in vivo with respect to their effect on metastasis. In a xenogeneic model using human colon carcinoma cancer cells, both antibody variants were effective in reducing metastasis to the liver. In contrast, only the 18D1 variant with enhanced ADCC activity, but not its ADCC-defective counterpart, suppressed lung metastasis in the RE NCA model. In sum, this suggests that Fn14 targeting might primarily act by triggering of antibody effector functions, but also by blockade of TWEA K-Fn14 interaction in some cases

  14. 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

  15. 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.

  16. 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.

  17. 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.

  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. Microbials for the production of monoclonal antibodies and antibody fragments.

    Science.gov (United States)

    Spadiut, Oliver; Capone, Simona; Krainer, Florian; Glieder, Anton; Herwig, Christoph

    2014-01-01

    Monoclonal antibodies (mAbs) and antibody fragments represent the most important biopharmaceutical products today. Because full length antibodies are glycosylated, mammalian cells, which allow human-like N-glycosylation, are currently used for their production. However, mammalian cells have several drawbacks when it comes to bioprocessing and scale-up, resulting in long processing times and elevated costs. By contrast, antibody fragments, that are not glycosylated but still exhibit antigen binding properties, can be produced in microbial organisms, which are easy to manipulate and cultivate. In this review, we summarize recent advances in the expression systems, strain engineering, and production processes for the three main microbials used in antibody and antibody fragment production, namely Saccharomyces cerevisiae, Pichia pastoris, and Escherichia coli. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Llama Single Domain Antibodies Specific for the 7 Botulinum Neurotoxin Serotypes as Heptaplex Immunoreagents

    Science.gov (United States)

    Collazo, M. Thelma; Garza, John A.; Hayhurst, Andrew

    2010-01-01

    Background There are currently 7 known serotypes of botulinum neurotoxin (BoNT) classified upon non-cross reactivity of neutralizing immunoglobulins. Non-neutralizing immunoglobulins, however, can exhibit cross-reactivities between 2 or more serotypes, particularly mosaic forms, which can hamper the development of highly specific immunoassays, especially if based on polyclonal antisera. Here we employ facile recombinant antibody technology to subtractively select ligands to each of the 7 BoNT serotypes, resulting in populations with very high specificity for their intended serotype. Methods and Findings A single llama was immunized with a cocktail of 7 BoNT toxoids to generate a phage display library of single domain antibodies (sdAb, VHH or nanobodies) which were selected on live toxins. Resulting sdAb were capable of detecting both toxin and toxin complex with the best combinations able to detect 100s-10s of pg per 50 µL sample in a liquid bead array. The most sensitive sdAb were combined in a heptaplex assay to identify each of the BoNT serotypes in buffer and milk and to a lesser extent in carrot juice, orange juice and cola. Several anti-A(1) sdAb recognized A2 complex, showing that subtype cross-reactivity within a serotype was evident. Many of our sdAb could act as both captor and tracer for several toxin and toxin complexes suggesting sdAb can be used as architectural probes to indicate BoNT oligomerisation. Six of 14 anti-A clones exhibited inhibition of SNAP-25 cleavage in the neuro-2A assay indicating some sdAb had toxin neutralizing capabilities. Many sdAb were also shown to be refoldable after exposure to high temperatures in contrast to polyclonal antisera, as monitored by circular dichroism. Conclusions Our panel of molecularly flexible antibodies should not only serve as a good starting point for ruggedizing assays and inhibitors, but enable the intricate architectures of BoNT toxins and complexes to be probed more extensively. PMID:20098614

  1. Structural insight in the inhibition of adherence of F4 fimbriae producing enterotoxigenic Escherichia coli by llama single domain antibodies.

    Science.gov (United States)

    Moonens, Kristof; Van den Broeck, Imke; Okello, Emmanuel; Pardon, Els; De Kerpel, Maia; Remaut, Han; De Greve, Henri

    2015-02-24

    Enterotoxigenic Escherichia coli that cause neonatal and post-weaning diarrhea in piglets express F4 fimbriae to mediate attachment towards host receptors. Recently we described how llama single domain antibodies (VHHs) fused to IgA, produced in Arabidopsis thaliana seeds and fed to piglets resulted in a progressive decline in shedding of F4 positive ETEC bacteria. Here we present the structures of these inhibiting VHHs in complex with the major adhesive subunit FaeG. A conserved surface, distant from the lactose binding pocket, is targeted by these VHHs, highlighting the possibility of targeting epitopes on single-domain adhesins that are non-involved in receptor binding.

  2. Heterologous radioimmunoassay for llama and alpaca luteinizing hormone with a monoclonal antibody, and equine standard and a human tracer

    International Nuclear Information System (INIS)

    Aba, M.A.; Forsberg, M.

    1995-01-01

    A radioimmunoassay for llama and alpaca LH was developed using a human I 125 LH tracer from a commercial kit, equine LH diluted in human LH free serum as standard, and amonoclonal antibody (518B7) specific for LH but with low species specificity. A 60-min delay in the addition of the tracer and overnight incubation gave a sensitivity of 0.8 μ3g L -1 . The intra-assay coefficient of variation was 37% at 1 μg L -1 , declined to 15% at 4 μg L -1 and was below 6% for concentrations up to 32 μg L -1 . The inter-assay coefficients of variation for 3 control samples were 20% (2.8 μg L -1 ), 16% (7.1 μg L -1 ) and 9.8% (19 μg L -1 ). In an attempt to increase sensitivity, all tubes were preincubated for 4 h at room temperature before adding the tracer, and the sample volume was increased from 50 μL to 100 μL (in the standard curve the increased volume was compensated for by human LH free serum). With this protocol, the assay sensitivity was 0,5 μg L -1 . The assay was validated clinically and demonstrated increased concentrations of LH after mating in llamas and alpacas. Furthermore, the assay was used to monitor LH responses to a single dose of GnRH in llamas (adult males and females at different ages). (au) 9 refs

  3. Comparison of newly developed anti-bone morphogenetic protein 4 llama-derived antibodies with commercially available BMP4 inhibitors.

    Science.gov (United States)

    Calpe, Silvia; Correia, Ana C P; Sancho-Serra, Maria Del Carmen; Krishnadath, Kausilia K

    2016-01-01

    Due to improved understanding of the role of bone morphogenetic protein 4 (BMP4) in an increasing number of diseases, the development of selective inhibitors of BMP4 is an attractive therapeutic option. The currently available BMP4 inhibitors are not suitable as therapeutics because of their low specificity and low effectiveness. Here, we compared newly generated anti-BMP4 llama-derived antibodies (VHHs) with 3 different types of commercially available BMP4 inhibitors, natural antagonists, small molecule BMPR inhibitors and conventional anti-BMP4 monoclonal antibodies. We found that the anti-BMP4 VHHs were as effective as the natural antagonist or small molecule inhibitors, but had higher specificity. We also showed that commercial anti-BMP4 antibodies were inferior in terms of both specificity and effectiveness. These findings might result from the fact that the VHHs C4C4 and C8C8 target a small region within the BMPR1 epitope of BMP4, whereas the commercial antibodies target other areas of the BMP4 molecule. Our results show that the newly developed anti-BMP4 VHHs are promising antibodies with better specificity and effectivity for inhibition of BMP4, making them an attractive tool for research and for therapeutic applications.

  4. Microbial platform technology for recombinant antibody fragment production: A review.

    Science.gov (United States)

    Gupta, Sanjeev Kumar; Shukla, Pratyoosh

    2017-02-01

    Recombinant antibody fragments are being used for the last few years as an important therapeutic protein to cure various critical and life threatening human diseases. Several expression platforms now days employed for the production of these recombinant fragments, out of which bacterial system has emerged a promising host for higher expression. Since, a small antibody fragment unlike full antibody does not require human-like post-translational modification therefore it is potentially expressed in prokaryotic production system. Recently, small antibody fragments such as scFvs (single-chain variable fragments) and Fabs (antibody fragments) which does not require glycosylation are successfully produced in bacteria and have commercially launched for therapeutic use as these fragments shows better tissue penetration and less immunogenic to human body compared to full-size antibody. Recently developed Wacker's ESETEC secretion technology is an efficient technology for the expression and secretion of the antibody fragment (Fab) exceeded up to 4.0 g/L while scFv up to 3.5 g/L into the fermentation broth. The Pfenex system and pOP prokaryotic expression vector are another platform used for the considerably good amount of antibody fragment production successfully. In this review, we summarize the recent progress on various expression platforms and cloning approaches for the production of different forms of antibody fragments in E. coli.

  5. Effective Inhibition of Bone Morphogenetic Protein Function by Highly Specific Llama-Derived Antibodies.

    Science.gov (United States)

    Calpe, Silvia; Wagner, Koen; El Khattabi, Mohamed; Rutten, Lucy; Zimberlin, Cheryl; Dolk, Edward; Verrips, C Theo; Medema, Jan Paul; Spits, Hergen; Krishnadath, Kausilia K

    2015-11-01

    Bone morphogenetic proteins (BMP) have important but distinct roles in tissue homeostasis and disease, including carcinogenesis and tumor progression. A large number of BMP inhibitors are available to study BMP function; however, as most of these antagonists are promiscuous, evaluating specific effects of individual BMPs is not feasible. Because the oncogenic role of the different BMPs varies for each neoplasm, highly selective BMP inhibitors are required. Here, we describe the generation of three types of llama-derived heavy chain variable domains (VHH) that selectively bind to either BMP4, to BMP2 and 4, or to BMP2, 4, 5, and 6. These generated VHHs have high affinity to their targets and are able to inhibit BMP signaling. Epitope binning and docking modeling have shed light into the basis for their BMP specificity. As opposed to the wide structural reach of natural inhibitors, these small molecules target the grooves and pockets of BMPs involved in receptor binding. In organoid experiments, specific inhibition of BMP4 does not affect the activation of normal stem cells. Furthermore, in vitro inhibition of cancer-derived BMP4 noncanonical signals results in an increase of chemosensitivity in a colorectal cancer cell line. Therefore, because of their high specificity and low off-target effects, these VHHs could represent a therapeutic alternative for BMP4(+) malignancies. ©2015 American Association for Cancer Research.

  6. Cloning, bacterial expression and crystallization of Fv antibody fragments

    Science.gov (United States)

    E´, Jean-Luc; Boulot, Ginette; Chitarra, V´ronique; Riottot, Marie-Madeleine; Souchon, H´le`ne; Houdusse, Anne; Bentley, Graham A.; Narayana Bhat, T.; Spinelli, Silvia; Poljak, Roberto J.

    1992-08-01

    The variable Fv fragments of antibodies, cloned in recombinant plasmids, can be expressed in bacteria as functional proteins having immunochemical properties which are very similar or identical with those of the corresponding parts of the parent eukaryotic antibodies. They offer new possibilities for the study of antibody-antigen interactions since the crystals of Fv fragments and of their complexes with antigen reported here diffract X-rays to a higher resolution that those obtained with the cognate Fab fragments. The Fv approach should facilitate the structural study of the combining site of antibodies and the further characterization of antigen-antibody interactions by site-directed mutagenesis experiments.

  7. 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

  8. Cowpox Virus in Llama, Italy

    Science.gov (United States)

    Brozzi, Alberto; Eleni, Claudia; Polici, Nicola; D’Alterio, Gianlorenzo; Carletti, Fabrizio; Scicluna, Maria Teresa; Castilletti, Concetta; Capobianchi, Maria R.; Di Caro, Antonino; Autorino, Gian Luca; Amaddeo, Demetrio

    2011-01-01

    Cowpox virus (CPXV) was isolated from skin lesions of a llama on a farm in Italy. Transmission electron microscopy showed brick-shaped particles consistent with orthopoxviruses. CPXV-antibodies were detected in llama and human serum samples; a CPXV isolate had a hemagglutinin sequence identical to CPXV-MonKre08/1–2-3 strains isolated from banded mongooses in Germany. PMID:21801638

  9. 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

  10. 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....

  11. 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...

  12. Coccidioidomycosis in the llama: case report and epidemiologic survey.

    Science.gov (United States)

    Muir, S; Pappagianis, D

    1982-12-01

    An 8-year-old nongravid female llama with a 1-month history of progressive posterior paresis was referred because of suspected degenerative myelopathy secondary to copper deficiency or plant poisoning. Neurologic examination revealed loss of conscious proprioception and slightly depressed bilateral patellar reflexes. Electromyographic examination of hindlimb flexors and extensors did not elicit evidence of lower motor neuron disease. Possible fragmentation and mottling of the 10th thoracic vertebral body were noted radiographically. Results of a lumbar CSF tap, complete blood count, and fecal flotation were not diagnostic. In the face of poor prognosis, the llama was euthanatized. Postmortem and histologic evaluation revealed, in addition to disseminated visceral granulomas, an extradural pyogranulomatous mass compressing the cord laterally at the level of T-10. Large numbers of Coccidioides immitis were dispersed throughout the granulomas. Complement fixing antibody tests in 11 other herd members showed evidence of C immitis infection in three.

  13. LLAMA Project

    Science.gov (United States)

    Arnal, E. M.; Abraham, Z.; Giménez de Castro, G.; de Gouveia dal Pino, E. M.; Larrarte, J. J.; Lepine, J.; Morras, R.; Viramonte, J.

    2014-10-01

    The project LLAMA, acronym of Long Latin American Millimetre Array is very briefly described in this paper. This project is a joint scientific and technological undertaking of Argentina and Brazil on the basis of an equal investment share, whose mail goal is both to install and to operate an observing facility capable of exploring the Universe at millimetre and sub/millimetre wavelengths. This facility will be erected in the argentinean province of Salta, in a site located at 4830m above sea level.

  14. Monoclonal antibodies and Fc fragments for treating solid tumors

    Directory of Open Access Journals (Sweden)

    Eisenbeis AM

    2012-01-01

    Full Text Available Andrea M Eisenbeis, Stefan J GrauDepartment of Neurosurgery, University Hospital of Cologne, Cologne, GermanyAbstract: Advances in biotechnology, better understanding of pathophysiological processes, as well as the identification of an increasing number of molecular markers have facilitated the use of monoclonal antibodies and Fc fragments in various fields in medicine. In this context, a rapidly growing number of these substances have also emerged in the field of oncology. This review will summarize the currently approved monoclonal antibodies used for the treatment of solid tumors with a focus on their clinical application, biological background, and currently ongoing trials.Keywords: targeted therapy, monoclonal antibodies, cancer, biological therapy

  15. Toxoplasma gondii infection in llama (Llama glama): acute visceral disseminated lesions, diagnosis, and development of tissue cysts.

    Science.gov (United States)

    Dubey, J P; Newell, T K; Verma, S K; Calero-Bernal, R; Stevens, E L

    2014-06-01

    Clinical toxoplasmosis has been reported in many species of warm-blooded animals but is rare in camelids. Here we report acute fatal systemic toxoplasmosis involving heart, thyroid gland, stomach, intestine, diaphragm, kidneys, adrenal glands, and liver of a 13-mo-old llama (Llama glama). Many Toxoplasma gondii tachyzoites were associated with tissue necrosis in multiple organs. Death was attributed to severe myocarditis. Ulcers associated with numerous tachyzoites were present in the C3 compartment of the stomach. Tissue cyst development was followed using bradyzoite-specific T. gondii antibodies. Individual intracellular, and groups of 2 or more, bradyzoites were identified in hepatocytes, biliary epithelium, myocardiocytes, lung, diaphragm, thyroid gland, spleen, and stomach. Lesions in the brain were a few microglial nodules and very early tissue cysts containing 1-3 bradyzoites. These observations suggest that the animal had acquired toxoplasmosis recently. Diagnosis was confirmed immunohistochemically by reaction with T. gondii -specific polyclonal rabbit serum but not with antibodies to the related protozoan Neospora caninum . Genetic typing using the DNA extracted from paraffin-embedded myocardium of llama and 10 PCR-restriction fragment length polymorphism (RFLP) markers revealed a type II allele at the SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1 L358, and Apico loci; therefore, this isolate belongs to the ToxoDB PCR-RFLP genotype #1, which is most common in North America and Europe.

  16. 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

  17. Monoclonal antibody fragment removal mediated by mixed mode resins.

    Science.gov (United States)

    O'Connor, Ellen; Aspelund, Matthew; Bartnik, Frank; Berge, Mark; Coughlin, Kelly; Kambarami, Mutsa; Spencer, David; Yan, Huiming; Wang, William

    2017-05-26

    Efforts to increase monoclonal antibody expression in cell culture can result in the presence of fragmented species requiring removal in downstream processing. Capto adhere, HEA Hypercel, and PPA Hypercel anion exchange/hydrophobic interaction mixed mode resins were evaluated for their fragment removal capabilities and found to separate large hinge IgG1 antibody fragment (LHF) from monomer. Removal of greater than 75% of LHF population occurred at pH 8 and low conductivity. The mechanism of fragment removal was investigated in two series of experiments. The first experimental series consisted of comparison to chromatographic behavior on corresponding single mode resins. Both single mode anion exchange and hydrophobic interaction resins failed to separate LHF. The second experimental series studied the impact of phase modifiers, ethylene glycol, urea, and arginine on the mixed mode mediated removal. The addition of ethylene glycol decreased LHF removal by half. Further decreases in LHF separation were seen upon incubation with urea and arginine. Therefore, it was discovered that the purification is the result of a mixed mode phenomena dominated by hydrophobic interaction and hydrogen bonding effects. The site of interaction between the LHF and mixed mode resin was determined by chemical labeling of lysine residues with sulfo-NHS acetate. The labeling identified the antibody hinge and light chain regions as mediating the fragment separation. Sequence analysis showed that under separation conditions, a hydrophobic proline patch and hydrogen bonding serine and threonine residues mediate the hinge interaction with the Capto adhere ligand. Additionally, a case study is presented detailing the optimization of fragment removal using Capto adhere resin to achieve purity and yield targets in a manufacturing facility. This study demonstrated that mixed mode resins can be readily integrated into commercial antibody platform processes when additional chromatographic abilities

  18. Chimeric recombinant antibody fragments in cardiac troponin I immunoassay.

    Science.gov (United States)

    Hyytiä, Heidi; Heikkilä, Taina; Brockmann, Eeva-Christine; Kekki, Henna; Hedberg, Pirjo; Puolakanaho, Tarja; Lövgren, Timo; Pettersson, Kim

    2015-03-01

    To introduce a novel nanoparticle-based immunoassay for cardiac troponin I (cTnI) utilizing chimeric antibody fragments and to demonstrate that removal of antibody Fc-part and antibody chimerization decrease matrix related interferences. A sandwich-type immunoassay for cTnI based on recombinant chimeric (mouse variable/human constant) antigen binding (cFab) antibodies and intrinsically fluorescent nanoparticles was developed. To test whether using chimeric antibody fragments helps to avoid matrix related interferences, samples (n=39) with known amounts of triglycerides, bilirubin, rheumatoid factor (RF) or human anti-mouse antibodies (HAMAs) were measured with the novel assay, along with a previously published nanoparticle-based research assay with the same antibody epitopes. The limit of detection (LoD) was 3.30ng/L. Within-laboratory precision for 29ng/L and 2819ng/L cTnI were 13.7% and 15.9%, respectively. Regression analysis with Siemens ADVIA Centaur® yielded a slope (95% confidence intervals) of 0.18 (0.17-1.19) and a y-intercept of 1.94 (-1.28-3.91) ng/L. When compared to a previously published nanoparticle-based assay, the novel assay showed substantially reduced interference in the tested interference prone samples, 15.4 vs. 51.3%. A rheumatoid factor containing sample was decreased from 241ng/L to fragments enabled the development of a sensitive (LoD=3.3ng/L) immunoassay for the detection of cTnI and decreased matrix related interferences, thus resulting in a lower number of falsely elevated cTnI-values. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Katerina T. Xenaki

    2017-10-01

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

  20. Recombinant fragment of an antibody tailored for direct radioiodination

    Czech Academy of Sciences Publication Activity Database

    Sedláček, Juraj; Fábry, Milan; Sieglová, Irena; Král, Vlastimil; Uhnáková, Bronislava; Mudra, M.; Kronrád, L.; Sawicka, A.; Mikolajczak, R.; Řezáčová, Pavlína

    2012-01-01

    Roč. 55, č. 1 (2012), s. 52-56 ISSN 0362-4803 R&D Projects: GA MPO 2A-2TP1/076; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z50520514 Keywords : I125 labelling * single-chain antibody variable fragment * tyrosine-rich polypeptide segment * fusion protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.240, year: 2012

  1. A simple and robust approach to immobilization of antibody fragments.

    Science.gov (United States)

    Ikonomova, Svetlana P; He, Ziming; Karlsson, Amy J

    2016-08-01

    Antibody fragments, such as the single-chain variable fragment (scFv), have much potential in research and diagnostics because of their antigen-binding ability similar to a full-sized antibody and their ease of production in microorganisms. Some applications of antibody fragments require immobilization on a surface, and we have established a simple immobilization method that is based on the biotin-streptavidin interaction and does not require a separate purification step. We genetically fused two biotinylation tags-the biotin carboxyl carrier protein (BCCP) or the AviTag minimal sequence-to six different scFvs (scFv13R4, scFvD10, scFv26-10, scFv3, scFv5, and scFv12) for site-specific biotinylation in vivo by endogenous biotin ligases produced by Escherichia coli. The biotinylated scFvs were immobilized onto streptavidin-coated plates directly from cell lysates, and immobilization was detected through enzyme-linked immunosorbent assays. All scFvs fusions were successfully immobilized, and scFvs biotinylated via the BCCP tag tended to immobilize better than those biotinylated via the AviTag, even when biotinylation efficiency was improved with the biotin ligase BirA. The ability of immobilized scFvs to bind antigens was confirmed using scFv13R4 and scFvD10 with their respective targets β-galactosidase and bacteriophage lambda head protein D (gpD). The immobilized scFv13R4 bound to β-galactosidase at the same level for both biotinylation tags when the surface was saturated with the scFv, and immobilized scFvs retained their functionality for at least 100days after immobilization. The simplicity and robustness of our method make it a promising approach for future applications that require antibody fragment immobilization. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A Single-Domain Llama Antibody Potently Inhibits the Enzymatic Activity of Botulinum Neurotoxin by Binding to the Non-Catalytic [alpha]-Exosite Binding Region

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Jianbo; Thompson, Aaron A.; Fan, Yongfeng; Lou, Jianlong; Conrad, Fraser; Ho, Mengfei; Pires-Alves, Melissa; Wilson, Brenda A.; Stevens, Raymond C.; Marks, James D. (UIUC); (Scripps); (UCSF)

    2010-08-13

    Ingestion or inhalation of botulinum neurotoxin (BoNT) results in botulism, a severe and frequently fatal disease. Current treatments rely on antitoxins, which, while effective, cannot reverse symptoms once BoNT has entered the neuron. For treatments that can reverse intoxication, interest has focused on developing inhibitors of the enzymatic BoNT light chain (BoNT Lc). Such inhibitors typically mimic substrate and bind in or around the substrate cleavage pocket. To explore the full range of binding sites for serotype A light chain (BoNT/A Lc) inhibitors, we created a library of non-immune llama single-domain VHH (camelid heavy-chain variable region derived from heavy-chain-only antibody) antibodies displayed on the surface of the yeast Saccharomyces cerevisiae. Library selection on BoNT/A Lc yielded 15 yeast-displayed VHH with equilibrium dissociation constants (K{sub d}) from 230 to 0.03 nM measured by flow cytometry. Eight of 15 VHH inhibited the cleavage of substrate SNAP25 (synaptosome-associated protein of 25,000 Da) by BoNT/A Lc. The most potent VHH (Aa1) had a solution K{sub d} for BoNT/A Lc of 1.47 x 10{sup -10} M and an IC{sub 50} (50% inhibitory concentration) of 4.7 x 10{sup -10} M and was resistant to heat denaturation and reducing conditions. To understand the mechanism by which Aa1 inhibited catalysis, we solved the X-ray crystal structure of the BoNT/A Lc-Aa1 VHH complex at 2.6 {angstrom} resolution. The structure reveals that the Aa1 VHH binds in the {alpha}-exosite of the BoNT/A Lc, far from the active site for catalysis. The study validates the utility of non-immune llama VHH libraries as a source of enzyme inhibitors and identifies the BoNT/A Lc {alpha}-exosite as a target for inhibitor development.

  3. 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

  4. 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

  5. Cell-free synthesis of functional antibody fragments to provide a structural basis for antibody-antigen interaction.

    Directory of Open Access Journals (Sweden)

    Takayoshi Matsuda

    Full Text Available Growing numbers of therapeutic antibodies offer excellent treatment strategies for many diseases. Elucidation of the interaction between a potential therapeutic antibody and its target protein by structural analysis reveals the mechanism of action and offers useful information for developing rational antibody designs for improved affinity. Here, we developed a rapid, high-yield cell-free system using dialysis mode to synthesize antibody fragments for the structural analysis of antibody-antigen complexes. Optimal synthesis conditions of fragments (Fv and Fab of the anti-EGFR antibody 059-152 were rapidly determined in a day by using a 30-μl-scale unit. The concentration of supplemented disulfide isomerase, DsbC, was critical to obtaining soluble antibody fragments. The optimal conditions were directly applicable to a 9-ml-scale reaction, with linear scalable yields of more than 1 mg/ml. Analyses of purified 059-152-Fv and Fab showed that the cell-free synthesized antibody fragments were disulfide-bridged, with antigen binding activity comparable to that of clinical antibodies. Examination of the crystal structure of cell-free synthesized 059-152-Fv in complex with the extracellular domain of human EGFR revealed that the epitope of 059-152-Fv broadly covers the EGF binding surface on domain III, including residues that formed critical hydrogen bonds with EGF (Asp355EGFR, Gln384EGFR, H409EGFR, and Lys465EGFR, so that the antibody inhibited EGFR activation. We further demonstrated the application of the cell-free system to site-specific integration of non-natural amino acids for antibody engineering, which would expand the availability of therapeutic antibodies based on structural information and rational design. This cell-free system could be an ideal antibody-fragment production platform for functional and structural analysis of potential therapeutic antibodies and for engineered antibody development.

  6. A sensitive progesterone enzyme immunoassay for cow, goat and llama plasma using a monoclonal antibody and Danazol (17-α-2,4-pregnadien-20-yno (2,3-D) isoxazol-17-ol) as a displacing agent

    International Nuclear Information System (INIS)

    Aba, M.A.; Carlsson, M.A.; Karlsson, A.; Forsberg, M.

    2001-01-01

    A sensitive progesterone enzyme immunoassay was developed for cow, goat and llama plasma using a monoclonal antibody and Danazol (17-α-2,4-pregnadien-20-yno (2,3-d) isoxazol-17-ol) as a displacing agent. The microtitration plates were first coated with progesterone 3 (o-carboxy-methyl) oxine: BSA conjugate. The immune reaction was performed by incubating overnight a mixture of 50 μL of plasma and 100 μL of first antibody. After washing, 100 μL of the second antibody (horse radish peroxidase conjugated anti-mouse IgG) were added. The plates were incubated for 1 hour and washed. Immediately the substrate solution was added and finally the reaction stopped and optical density measured. This assay allows accurate determination of progesterone in plasma from several species with good specificity, precision and accuracy, and is suitable for the rapid assessment of luteal function and reproductive status in both clinical and research situations. (author)

  7. Characterization of Tumor-Avid Antibody Fragments Genetically Engineered for Mono-Specific Radionuclide Chelation

    International Nuclear Information System (INIS)

    Quinn, T.P.

    2003-01-01

    The successful clinical application of targeted-radiopharmaceuticals depends on the development of molecules that optimize tumor specific radionuclide deposition and minimize non-specific organ irradiation. To this end, this proposal outlines a research effort to identify and evaluate novel antibodies and antibody fragments that bind breast tumors. The tumor-avid antibodies will be investigated for as imaging and therapeutic agents and to gain a better understanding of the pharmacokinetics and metabolism of radiolabeled tumor-avid antibody fragments through the use of site-specifically labeled molecules. Antibodies or antibody fragments, that bind breast carcinoma carbohydrate antigens, will be obtained from hybridoma or bacteriophage library screening. More specifically, antibody fragments that bind the carcinoma-associated Thomsen-Friedenreich (T) antigen will be radiolabeled with 99m Tc and 188 Re at a natural amino acid chelation site and will be investigated in vivo for their abilities to target human breast tumors. In addition, site-specific radiolabeled antibody fragments will be biosynthesized using misacylated suppressor tRNAs. Homogeneously radiolabeled populations of antibody fragments will be used to investigate the effects of radionuclide location and chelation chemistries on their biodistribution and metabolism. It is hypothesized that site-specifically radiolabeled antibody fragments will possess enhanced tumor imaging and therapeutic properties due to optimal label location and conjugation chemistries. New insights into the factors that govern antibody metabolism in vivo are also expected from this work. Results from these studies should enhance our ability to design and synthesize radiolabeled antibody fragments that have improved pharmacokinetic properties. The studies in this proposal involve basic research into the development of antibody-based radiopharmaceuticals, with the ultimate goal of application in humans. This type of basic nuclear

  8. Llama nanoantibodies with therapeutic potential against human norovirus diarrhea.

    Science.gov (United States)

    Garaicoechea, Lorena; Aguilar, Andrea; Parra, Gabriel I; Bok, Marina; Sosnovtsev, Stanislav V; Canziani, Gabriela; Green, Kim Y; Bok, Karin; Parreño, Viviana

    2015-01-01

    Noroviruses are a major cause of acute gastroenteritis, but no vaccines or therapeutic drugs are available. Llama-derived single chain antibody fragments (also called VHH) are small, recombinant monoclonal antibodies of 15 kDa with several advantages over conventional antibodies. The aim of this study was to generate recombinant monoclonal VHH specific for the two major norovirus (NoV) genogroups (GI and GII) in order to investigate their potential as immunotherapy for the treatment of NoV diarrhea. To accomplish this objective, two llamas were immunized with either GI.1 (Norwalk-1968) or GII.4 (MD2004) VLPs. After immunization, peripheral blood lymphocytes were collected and used to generate two VHH libraries. Using phage display technology, 10 VHH clones specific for GI.1, and 8 specific for GII.4 were selected for further characterization. All VHH recognized conformational epitopes in the P domain of the immunizing VP1 capsid protein, with the exception of one GII.4 VHH that recognized a linear P domain epitope. The GI.1 VHHs were highly specific for the immunizing GI.1 genotype, with only one VHH cross-reacting with GI.3 genotype. The GII.4 VHHs reacted with the immunizing GII.4 strain and showed a varying reactivity profile among different GII genotypes. One VHH specific for GI.1 and three specific for GII.4 could block the binding of homologous VLPs to synthetic HBGA carbohydrates, saliva, and pig gastric mucin, and in addition, could inhibit the hemagglutination of red blood cells by homologous VLPs. The ability of Nov-specific VHHs to perform well in these surrogate neutralization assays supports their further development as immunotherapy for NoV treatment and immunoprophylaxis.

  9. Labeling and stability of radiolabeled antibody fragments by a direct 99mTc-labeling method

    International Nuclear Information System (INIS)

    Pak, K.Y.; Nedelman, M.A.; Tam, S.H.; Wilson, E.; Daddona, P.E.

    1992-01-01

    The in vitro labeling and stability of 99m Tc-labeled antibody Fab' fragments prepared by a direct labeling technique were evaluated. Eight antibody fragments derived from murine IgG1 (N = 5), IgG2a (N = 2) and IgG3 (N = 1) isotypes were labeled with a preformed 99m Tc-D-glucarate complex. No loss of radioactivity incorporation was observed for all the 99m Tc-labeled antibody fragments after 24 h incubation at 37 o C. 99m Tc-labeled antibody fragments (IgG1, N = 2; IgG2a, n = 2; IgG3, N = 1) were stable upon challenge with DTPA, EDTA or acidic pH. Using the affinity chromatography technique, two of the 99m Tc-labeled antibody fragments displayed no loss of immunoreactivity after prolonged incubation in phosphate buffer up to 24 h at 37 o C. Bonding between 99m Tc and antibody fragments was elucidated by challenging with a diamide ditholate (N 2 S 2 ) compound. The Fab' with IgG2a isotype displayed tighter binding to 99m Tc in comparison to Fab' from IgG1 and IgG3 isotype in N 2 S 2 challenge and incubation with human plasma. The in vivo biodistribution of five 99m Tc-labeled fragments were evaluated in normal mice. (Author)

  10. Scanning force microscopy and fluorescence microscopy of microcontact printed antibodies and antibody fragments.

    Science.gov (United States)

    LaGraff, John R; Chu-LaGraff, Quynh

    2006-05-09

    Unlabeled primary immunoglobulin G (IgG) antibodies and its F(ab')2 and Fc fragments were attached to oxygen-plasma-cleaned glass substrates using either microcontact printing (MCP) or physical adsorption during bath application from dilute solutions. Fluorescently labeled secondary IgGs were then bound to surface-immobilized IgG, and the relative surface coverage was determined by measuring the fluorescence intensity. Results indicated that the surface coverage of IgG increased with increasing protein solution concentration for both MCP and bath-applied IgG and that a greater concentration of IgG was transferred to a glass substrate using MCP than during physisorption during bath applications. Scanning force microscopy (SFM) showed that patterned MCP IgG monolayers were 5 nm in height, indicating that IgG molecules lie flat on the substrate. After incubation with a secondary IgG, the overall line thickness increased to around 15 nm, indicating that the secondary IgG was in a more vertical orientation with respect to the substrate. The surface roughness of these MCP patterned IgG bilayers as measured by SFM was observed to increase with increasing surface coverage. Physisorption of IgG to both unmodified patterned polydimethylsiloxane (PDMS) stamps and plasma-cleaned glass substrates was modeled by Langmuir adsorption kinetics yielding IgG binding constants of K(MCP) = 1.7(2) x 10(7) M(-1) and K(bath) = 7.8(7) x 10(5) M(-1), respectively. MCP experiments involving primary F(ab')2 and Fc fragments incubated in fluorescently labeled fragment-specific secondary IgGs were carried out to test for the function and orientation of IgG. Finally, possible origins of MCP stamping defects such as pits, pull outs, droplets, and reverse protein transfer are discussed.

  11. Isolation of Single-Domain Antibody Fragments That Preferentially Detect Intact (146S Particles of Foot-and-Mouth Disease Virus for Use in Vaccine Quality Control

    Directory of Open Access Journals (Sweden)

    Michiel M. Harmsen

    2017-08-01

    Full Text Available Intact (146S foot-and-mouth disease virus (FMDVs can dissociate into specific (12S viral capsid degradation products. FMD vaccines normally consist of inactivated virions. Vaccine quality is dependent on 146S virus particles rather than 12S particles. We earlier isolated two llama single-domain antibody fragments (VHHs that specifically recognize 146S particles of FMDV strain O1 Manisa and shown their potential use in quality control of FMD vaccines during manufacturing. These 146S-specific VHHs were specific for particular O serotype strains and did not bind strains from other FMDV serotypes. Here, we describe the isolation of 146S-specific VHHs against FMDV SAT2 and Asia 1 strains by phage display selection from llama immune libraries. VHHs that bind both 12S and 146S particles were readily isolated but VHHs that bind specifically to 146S particles could only be isolated by phage display selection using prior depletion for 12S particles. We obtained one 146S-specific VHH—M332F—that binds to strain Asia 1 Shamir and several VHHs that preferentially bind 146S particles of SAT2 strain SAU/2/00, from which we selected VHH M379F for further characterization. Both M332F and M379F did not bind FMDV strains from other serotypes. In a sandwich enzyme-linked immunosorbent assay (ELISA employing unlabeled and biotinylated versions of the same VHH M332F showed high specificity for 146S particles but M379F showed lower 146S-specificity with some cross-reaction with 12S particles. These ELISAs could detect 146S particle concentrations as low as 2.3–4.6 µg/l. They can be used for FMD vaccine quality control and research and development, for example, to identify virion stabilizing excipients.

  12. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix

    OpenAIRE

    Hui Liang; Xiaoran Li; Bin Wang; Bing Chen; Yannan Zhao; Jie Sun; Yan Zhuang; Jiajia Shi; He Shen; Zhijun Zhang; Jianwu Dai

    2016-01-01

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of ...

  13. Antibody Fragments as Potential Biopharmaceuticals for Cancer Therapy: Success and Limitations.

    Science.gov (United States)

    Kholodenko, Roman V; Kalinovsky, Daniel V; Doronin, Igor I; Ponomarev, Eugene D; Kholodenko, Irina V

    2017-08-17

    Monoclonal antibodies (mAbs) are an important class of therapeutic agents approved for the therapy of many types of malignancies. However, in certain cases applications of conventional mAbs have several limitations in anticancer immunotherapy. These limitations include insufficient efficacy and adverse effects. The antigen-binding fragments of antibodies have a considerable potential to overcome the disadvantages of conventional mAbs, such as poor penetration into solid tumors and Fc-mediated bystander activation of the immune system. Fragments of antibodies retain antigen specificity and part of functional properties of conventional mAbs and at the same time have much better penetration into the tumors and a greatly reduced level of adverse effects. Recent advantages in antibody engineering allowed to produce different types of antibody fragments with improved structure and properties for efficient elimination of tumor cells. These molecules opened up new perspectives for anticancer therapy. Here we will overview the structural features of the various types of antibody fragments and their applications for anticancer therapy as separate molecules and as part of complex conjugates or structures. Mechanisms of antitumor action of antibody fragments as well as their advantages and disadvantages for clinical application will be discussed in this review. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Antigen-targeting strategies using single-domain antibody fragments

    NARCIS (Netherlands)

    Duarte, Joao Nuno Silva

    2017-01-01

    Antibodies display high selectivity and affinity and have been the preferred platform for antigen targeting. Despite the development of antigen-delivery systems that enable T cell activation, targeting approaches that enhance antibody responses need improvement. This need specially applies to poorly

  15. Properties, production and applications of camelid single-domain antibody fragments

    NARCIS (Netherlands)

    Harmsen, M.M.; Haard, de H.J.

    2007-01-01

    Camelids produce functional antibodies devoid of light chains of which the single N-terminal domain is fully capable of antigen binding. These single-domain antibody fragments (VHHs or Nanobodies®) have several advantages for biotechnological applications. They are well expressed in microorganisms

  16. Fab antibody fragment-functionalized liposomes for specific targeting of antigen-positive cells

    Czech Academy of Sciences Publication Activity Database

    Ohradanova-Repic, A.; Nogueira, E.; Hartl, I.; Gomes, A.C.; Preto, A.; Steinhuber, E.; Muehlgrabner, V.; Repic, M.; Kuttke, M.; Zwirzitz, A.; Prouza, M.; Suchánek, M.; Wozniak-Knopp, G.; Hořejší, Václav; Schabbauer, G.; Cavaco-Paulo, A.; Stockinger, H.

    2018-01-01

    Roč. 14, č. 1 (2018), s. 123-130 ISSN 1549-9634 Institutional support: RVO:68378050 Keywords : Active targeting * Liposome functionalization * Immunoliposome * Antibody engineering * Recombinant Fab antibody fragment Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Cell biology Impact factor: 5.720, year: 2016

  17. Inhibition of ligand exchange kinetics via active-site trapping with an antibody fragment.

    Science.gov (United States)

    Oyen, David; Steyaert, Jan; Barlow, John N

    2014-04-01

    We describe the first example of an inhibitory antibody fragment (nanobody ca1697) that binds simultaneously to an enzyme (the enzyme dihydrofolate reductase from Escherichia coli) and its bound substrate (folate). Binding of the antibody to the substrate causes a 20-fold reduction in the rate of folate exchange kinetics. This work opens up the prospect of designing new types of antibody-based inhibitors of enzymes and receptors through suitable design of immunogens.

  18. The Llama Project.

    Science.gov (United States)

    Ganzel, Candy; Stuglik, Jan

    2003-01-01

    At a suburban Indiana elementary school, the Project Approach serves as the basis of the curriculum in all Kindergarten classrooms. The four classes of 5- and 6-year-old children at this school chose to study llamas. This article discusses how the project evolved, describes the three phases of the project, and provides teachers' reflections on the…

  19. Production and characterization of anti-human IgG F(ab')2 antibody fragment.

    Science.gov (United States)

    Valedkarimi, Zahra; Nasiri, Hadi; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Esparvarinha, Mojghan; Majidi, Jafar

    2018-04-10

    In present study an optimized protocol for the separation of antibodies into antigen-binding fragments F(ab')2 using pepsin digestion was investigated. The production of these fragments is a consequential step in the development of medical research, treatment and diagnosis. For production of polyclonal antibody rabbit received antigen in four steps. The rabbit serum at 1/128000 dilution showed high absorbance in reaction with human IgG at the designed ELISA method. Rabbit IgG was purified by Ion-Exchange Chromatography (IEC) method. Purity was assessed by SDS-PAGE method. In non-reduced condition only one band was seen in about 150 kDa MW position and in reduced form, two bands were seen in 50 and 25 kDa MW positions. Rabbit IgG was digested by pepsin enzyme. The antibody fragments solution was applied to Gel filtration column to isolate the F(ab')2. Non-reduced SDS-PAGE for determining the purity of F(ab')2 fragment resulted in one band in 100 kDa corresponds to F(ab')2 fragment and a band in 150 kDa MW position corresponds to undigested IgG antibodies. The activities of FITC conjugated F(ab')2 fragment and commercial ones were compared using flowcytometry method. The activity results implied that the FITC conjugated- anti human F(ab')2 fragment worked as efficiently as the commercial one.

  20. Development of human antibody fragments using antibody phage display for the detection and diagnosis of Venezuelan equine encephalitis virus (VEEV

    Directory of Open Access Journals (Sweden)

    Hust Michael

    2008-09-01

    Full Text Available Abstract Background Venezuelan equine encephalitis virus (VEEV belongs to the Alphavirus group. Several species of this family are also pathogenic to humans and are recognized as potential agents of biological warfare and terrorism. The objective of this work was the generation of recombinant antibodies for the detection of VEEV after a potential bioterrorism assault or an natural outbreak of VEEV. Results In this work, human anti-VEEV single chain Fragments variable (scFv were isolated for the first time from a human naïve antibody gene library using optimized selection processes. In total eleven different scFvs were identified and their immunological specificity was assessed. The specific detection of the VEEV strains TC83, H12/93 and 230 by the selected antibody fragments was proved. Active as well as formalin inactivated virus particles were recognized by the selected antibody fragments which could be also used for Western blot analysis of VEEV proteins and immunohistochemistry of VEEV infected cells. The anti-VEEV scFv phage clones did not show any cross-reactivity with Alphavirus species of the Western equine encephalitis virus (WEEV and Eastern equine encephalitis virus (EEEV antigenic complex, nor did they react with Chikungunya virus (CHIKV, if they were used as detection reagent. Conclusion For the first time, this study describes the selection of antibodies against a human pathogenic virus from a human naïve scFv antibody gene library using complete, active virus particles as antigen. The broad and sensitive applicability of scFv-presenting phage for the immunological detection and diagnosis of Alphavirus species was demonstrated. The selected antibody fragments will improve the fast identification of VEEV in case of a biological warfare or terroristic attack or a natural outbreak.

  1. 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.

  2. Generation of “LYmph Node Derived Antibody Libraries” (LYNDAL) for selecting fully human antibody fragments with therapeutic potential.

    Science.gov (United States)

    Diebolder, Philipp; Keller, Armin; Haase, Stephanie; Schlegelmilch, Anne; Kiefer, Jonathan D; Karimi, Tamana; Weber, Tobias; Moldenhauer, Gerhard; Kehm, Roland; Eis-Hübinger, Anna M; Jäger, Dirk; Federspil, Philippe A; Herold-Mende, Christel; Dyckhoff, Gerhard; Kontermann, Roland E; Arndt, Michaela A E; Krauss, Jürgen

    2014-01-01

    The development of efficient strategies for generating fully human monoclonal antibodies with unique functional properties that are exploitable for tailored therapeutic interventions remains a major challenge in the antibody technology field. Here, we present a methodology for recovering such antibodies from antigen-encountered human B cell repertoires. As the source for variable antibody genes, we cloned immunoglobulin G (IgG)-derived B cell repertoires from lymph nodes of 20 individuals undergoing surgery for head and neck cancer. Sequence analysis of unselected “LYmph Node Derived Antibody Libraries” (LYNDAL) revealed a naturally occurring distribution pattern of rearranged antibody sequences, representing all known variable gene families and most functional germline sequences. To demonstrate the feasibility for selecting antibodies with therapeutic potential from these repertoires, seven LYNDAL from donors with high serum titers against herpes simplex virus (HSV) were panned on recombinant glycoprotein B of HSV-1. Screening for specific binders delivered 34 single-chain variable fragments (scFvs) with unique sequences. Sequence analysis revealed extensive somatic hypermutation of enriched clones as a result of affinity maturation. Binding of scFvs to common glycoprotein B variants from HSV-1 and HSV-2 strains was highly specific, and the majority of analyzed antibody fragments bound to the target antigen with nanomolar affinity. From eight scFvs with HSV-neutralizing capacity in vitro,the most potent antibody neutralized 50% HSV-2 at 4.5 nM as a dimeric (scFv)2. We anticipate our approach to be useful for recovering fully human antibodies with therapeutic potential.

  3. Fv-clasp: An Artificially Designed Small Antibody Fragment with Improved Production Compatibility, Stability, and Crystallizability.

    Science.gov (United States)

    Arimori, Takao; Kitago, Yu; Umitsu, Masataka; Fujii, Yuki; Asaki, Ryoko; Tamura-Kawakami, Keiko; Takagi, Junichi

    2017-10-03

    Antibody fragments are frequently used as a "crystallization chaperone" to aid structural analysis of complex macromolecules that are otherwise crystallization resistant, but conventional fragment formats have not been designed for this particular application. By fusing an anti-parallel coiled-coil structure derived from the SARAH domain of human Mst1 kinase to the variable region of an antibody, we succeeded in creating a novel chimeric antibody fragment of ∼37 kDa, termed "Fv-clasp," which exhibits excellent crystallization compatibility while maintaining the binding ability of the original IgG molecule. The "clasp" and the engineered disulfide bond at the bottom of the Fv suppressed the internal mobility of the fragment and shielded hydrophobic residues, likely contributing to the high heat stability and the crystallizability of the Fv-clasp. Finally, Fv-clasp antibodies showed superior "chaperoning" activity over conventional Fab fragments, and facilitated the structure determination of an ectodomain fragment of integrin α6β1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Isolation and expression of recombinant antibody fragments to the biological warfare pathogen Brucella melitensis.

    Science.gov (United States)

    Hayhurst, Andrew; Happe, Scott; Mabry, Robert; Koch, Zephyr; Iverson, Brent L; Georgiou, George

    2003-05-01

    Brucella melitensis is a highly infectious animal pathogen able to cause a recurring debilitating disease in humans and is therefore high on the list of biological warfare agents. Immunoglobulin genes from mice immunized with gamma-irradiated B. melitensis strain 16M were used to construct a library that was screened by phage display against similarly prepared bacteria. The selected phage particles afforded a strong enzyme-linked immunosorbent assay (ELISA) signal against gamma-irradiated B. melitensis cells. However, extensive efforts to express the respective single chain antibody variable region fragment (scFv) in soluble form failed due to: (i) poor solubility and (ii) in vivo degradation of the c-myc tag used for the detection of the recombinant antibodies. Both problems could be addressed by: (i) fusing a human kappa light chain constant domain (Ck) chain to the scFv to generate single chain antibody fragment (scAb) antibody fragments and (ii) by co-expression of the periplasmic chaperone Skp. While soluble, functional antibodies could be produced in this manner, phage-displaying scFvs or scAbs were still found to be superior ELISA reagents for immunoassays, due to the large signal amplification afforded by anti-phage antibodies. The isolated phage antibodies were shown to be highly specific to B. melitensis and did not recognize Yersinia pseudotuberculosis in contrast to the existing diagnostic monoclonal YST 9.2.1.

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

    NARCIS (Netherlands)

    Xenaki, Katerina T; Oliveira, Sabrina; van Bergen En Henegouwen, Paul M P

    2017-01-01

    The use of antibody-based therapeutics has proven very promising for clinical applications in cancer patients, with multiple examples of antibodies and antibody-drug conjugates successfully applied for the treatment of solid tumors and lymphomas. Given reported recurrence rates, improvements are

  6. Fragmentation, labeling and biodistribution studies of KS1/4, a monoclonal antibody

    International Nuclear Information System (INIS)

    Mohd, S.B.

    1987-01-01

    In this study, an IgG2a (KS1/4), a monoclonal antibody (MoAb) specific against a human lung adenocarcinoma (UCLA P-3) was successfully fragmented enzymatically to yield F(ab') 2 and Fab by using pepsin and papain, respectively. The kinetic of fragmentation of the MoAb was compared to that of human immunoglobulin G (IgG). A similar pattern of fragmentation was observed with both antibodies with a higher percentage yield of the F(ab') 2 and Fab obtained upon the fragmentation of the IgG by the enzymes. The KS1/4 and the two fragments were labeled with three different radionuclides, namely iodine-131, indium-111 and selenium-75. The radioiodination of the MoAb and the fragments was carried out by using a modified chloramine-T method. Radiometal labeling of the MoAb and the fragments with indium-111 was performed by using DTPA as a bifunctional chelating agent, while intrinsic labeling of the MoAb was done by culturing the hybridoma in the presence of 75 Se-methionine. The biodistribution of the radiolabeled MoAb, F(ab') 2 and Fab fragments were performed by injecting the preparations intravenously into nude mice bearing human lung adenocarcinoma

  7. Direct labelling of monomeric antibody fragments Fab' with 99mTc

    International Nuclear Information System (INIS)

    Li Jun; Wang Shizhen; Yang Ziyi

    1994-01-01

    Direct labelling method and conditions of monomeric antibody Fab' with 99m Tc were investigated. Polyclonal antibody IgG was digested with ficin to produce dimeric fragments F(ab') 2 , which was subsequently reduced to monomeric fragments Fab' with 2-mercaptoethylamine. Finally, Fab' was incubated with sodium gluconate (Sn(II)) kit solution and 99m TcO 4 - eluted at room temperature to form 99m Tc-Fab'. The labelling efficiency was 85%-95%. The stability of labelled products was satisfactory and the elimination rate was faster than 99m Tc-IgG

  8. Computational identification of antigen-binding antibody fragments.

    Science.gov (United States)

    Burkovitz, Anat; Leiderman, Olga; Sela-Culang, Inbal; Byk, Gerardo; Ofran, Yanay

    2013-03-01

    Determining which parts of the Ab are essential for Ag recognition and binding is crucial for understanding B cell-mediated immunity. Identification of fragments of Abs that maintain specificity to the Ag will also allow for the development of improved Ab-based therapy and diagnostics. In this article, we show that structural analysis of Ab-Ag complexes reveals which fragments of the Ab may bind the Ag on their own. In particular, it is possible to predict whether a given CDR is likely to bind the Ag as a peptide by analyzing the energetic contribution of each CDR to Ag binding and by assessing to what extent the interaction between that CDR and the Ag depends on other CDRs. To demonstrate this, we analyzed five Ab-Ag complexes and predicted for each of them which of the CDRs may bind the Ag on its own as a peptide. We then show that these predictions are in agreement with our experimental analysis and with previously published experimental results. These findings promote our understanding of the modular nature of Ab-Ag interactions and lay the foundation for the rational design of active CDR-derived peptides.

  9. Composition and method for detecting cancer with technetium labeled antibody fragments

    International Nuclear Information System (INIS)

    Burchiel, S. W.; Crockford, D. R.; Rhodes, B. A.

    1984-01-01

    F(ab') 2 or Fab fragments of antibodies to: (a) human chorionic gonadotropin (hCG), hCG alpha subunit, hCG beta subunit, or an hCG-like material; or (b) other tumor specific or tumor associated molecules, to include carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), human melanoma associated antigens, human sarcoma associated antigens or other antigens, are radiolabeled with technetium-99m (Tc-99m). When the F(ab') 2 or Fab fragments of antibody to such tumor associated antigens are injected intravenously into a patient, the radiolabeled composition accumulates at tumor sites. The accumulation of the cancer seeking radiopharmaceutical at tumor sites permits detection by external gamma scintigraphy. Thus, the composition is useful in the monitoring, localization and detection of cancer in the body. In an alternative composition, a double antibody approach to tumor localization using radiolabeled F(ab') 2 or Fab fragments is utilized. In this approach, a tumor specific antibody in the form of IgG, F(ab') 2 or Fab is first administered to a patient intravenously. Following a sufficient period of time, a second antibody in the form of F(ab') 2 or Fab is administered. The second antibody is radiolabeled with Tc-99m and has the property that it is reactive with the first antibody. This double antibody method has the advantage over a single antibody approach in that smaller tumors can be localized and detected and that the total amount of radioactive trace localized at the cancer site is increased

  10. Engineering Venom’s Toxin-Neutralizing Antibody Fragments and Its Therapeutic Potential

    Directory of Open Access Journals (Sweden)

    Larissa M. Alvarenga

    2014-08-01

    Full Text Available Serum therapy remains the only specific treatment against envenoming, but anti-venoms are still prepared by fragmentation of polyclonal antibodies isolated from hyper-immunized horse serum. Most of these anti-venoms are considered to be efficient, but their production is tedious, and their use may be associated with adverse effects. Recombinant antibodies and smaller functional units are now emerging as credible alternatives and constitute a source of still unexploited biomolecules capable of neutralizing venoms. This review will be a walk through the technologies that have recently been applied leading to novel antibody formats with better properties in terms of homogeneity, specific activity and possible safety.

  11. Human antibody fragments specific for the epidermal growth factor receptor selected from large non-immunised phage display libraries.

    Science.gov (United States)

    Souriau, Christelle; Rothacker, Julie; Hoogenboom, Hennie R; Nice, Edouard

    2004-09-01

    Antibodies to EGFR have been shown to display anti-tumour effects mediated in part by inhibition of cellular proliferation and angiogenesis, and by enhancement of apoptosis. Humanised antibodies are preferred for clinical use to reduce complications with HAMA and HAHA responses frequently seen with murine and chimaeric antibodies. We have used depletion and subtractive selection strategies on cells expressing the EGFR to sample two large antibody fragment phage display libraries for the presence of human antibodies which are specific for the EGFR. Four Fab fragments and six scFv fragments were identified, with affinities of up to 2.2nM as determined by BIAcore analysis using global fitting of the binding curves to obtain the individual rate constants (ka and kd). This overall approach offers a generic screening method for the identification of growth factor specific antibodies and antibody fragments from large expression libraries and has potential for the rapid development of new therapeutic and diagnostic reagents.

  12. 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

  13. 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.

  14. Llama immunization with full-length VAR2CSA generates cross-reactive and inhibitory single-domain antibodies against the DBL1X domain.

    Science.gov (United States)

    Nunes-Silva, Sofia; Gangnard, Stéphane; Vidal, Marta; Vuchelen, Anneleen; Dechavanne, Sebastien; Chan, Sherwin; Pardon, Els; Steyaert, Jan; Ramboarina, Stephanie; Chêne, Arnaud; Gamain, Benoît

    2014-12-09

    VAR2CSA stands today as the leading vaccine candidate aiming to protect future pregnant women living in malaria endemic areas against the severe clinical outcomes of pregnancy associated malaria (PAM). The rational design of an efficient VAR2CSA-based vaccine relies on a profound understanding of the molecular interactions associated with P. falciparum infected erythrocyte sequestration in the placenta. Following immunization of a llama with the full-length VAR2CSA recombinant protein, we have expressed and characterized a panel of 19 nanobodies able to recognize the recombinant VAR2CSA as well as the surface of erythrocytes infected with parasites originating from different parts of the world. Domain mapping revealed that a large majority of nanobodies targeted DBL1X whereas a few of them were directed towards DBL4ε, DBL5ε and DBL6ε. One nanobody targeting the DBL1X was able to recognize the native VAR2CSA protein of the three parasite lines tested. Furthermore, four nanobodies targeting DBL1X reproducibly inhibited CSA adhesion of erythrocytes infected with the homologous NF54-CSA parasite strain, providing evidences that DBL1X domain is part or close to the CSA binding site. These nanobodies could serve as useful tools to identify conserved epitopes shared between different variants and to characterize the interactions between VAR2CSA and CSA.

  15. Phage-display libraries of murine and human antibody Fab fragments

    DEFF Research Database (Denmark)

    Engberg, J; Andersen, P S; Nielsen, L K

    1996-01-01

    We provide efficient and detailed procedures for construction, expression, and screening of comprehensive libraries of murine or human antibody Fab fragments displayed on the surface of filamentous phage. In addition, protocols for producing and using ultra-electrocompetent cells, for producing Fab...

  16. 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

  17. Antibody engineering using phage display with a coiled-coil heterodimeric Fv antibody fragment.

    Directory of Open Access Journals (Sweden)

    Xinwei Wang

    Full Text Available A Fab-like antibody binding unit, ccFv, in which a pair of heterodimeric coiled-coil domains was fused to V(H and V(L for Fv stabilization, was constructed for an anti-VEGF antibody. The anti-VEGF ccFv showed the same binding affinity as scFv but significantly improved stability and phage display level. Furthermore, phage display libraries in the ccFv format were constructed for humanization and affinity maturation of the anti-VEGF antibody. A panel of V(H frameworks and V(H-CDR3 variants, with a significant improvement in affinity and expressibility in both E. coli and yeast systems, was isolated from the ccFv phage libraries. These results demonstrate the potential application of the ccFv antibody format in antibody engineering.

  18. 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.

  19. 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

  20. Design and Testing of a Thermostable Platform for Multimerization of Single Domain Antibodies

    Science.gov (United States)

    2012-08-01

    H.J. Properties , production, and applications of camelid single domain antibody fragments. Appl. Microbiol. Biot. 2007, 77, 13‒22. 2. Goldman...Conway, J.; Sherwood, L.J.; Fech, M.; Vo, B.; Liu, J.L.; Hayhurst, A. Thermostable llama single domain antibodies for detection of Botulinum A...antiparallel coiled-coil inserted. J. Mol. Bio. 2001, 306, 25‒35. 9. Liu, J.L.; Anderson, G.P.; Goldman, E.R. Isolation of anti- toxin single domain

  1. Detection of experimental myocarditis by monoclonal antimyosin antibody, Fab fragment

    Energy Technology Data Exchange (ETDEWEB)

    Rezkalla, S.; Kloner, R.A.; Khaw, B.A.; Haber, E.; Fallon, J.T.; Smith, F.E.; Khatib, R.

    1989-02-01

    The purpose of this study was to determine whether monoclonal antimyosin Fab (antigen binding fragment) was capable of labeling hearts with experimental coxsackievirus myocarditis, and to determine whether Fab could be used for detecting myocardial damage in either early or chronic phases of the disease. Sixty-five, 3-week-old cesarean-derived 1 (CD 1) mice were divided into two groups: group I (noninfected animals) and group II (infected with coxsackievirus B3). Mice from each group were killed on days 7, 17, 30, or 90 of infection. Forty-eight hours before killing, mice were injected with monoclonal I-125 antimyosin, Fab (25 microCi/injection) and radioactivity was counted in the heart. Selected heart sections were also examined by autoradiography. Heart radioactivity, count/m/mg (m +/- SEM) on days 7, 17, 30, and 90 of infection was 10.8 +/- 1.7, 21.3 +/- 1.1, 11.2 +/- 3.4, and 12.4 +/- 1.5 for group I, versus 36.7 +/- 8.0 (p less than 0.01), 50.0 +/- 4.5 (p less than 0.001), 33.4 +/- 16.1 (p = NS), and 40.6 +/- 8.5 (p less than 0.01) for group II, respectively. Autoradiography revealed focal uptake within areas of necrotic myocardium. We conclude that I125 Fab may be useful in detecting myocardial damage in the experimental model of murine myocarditis up to day 90 of infection.

  2. Detection of experimental myocarditis by monoclonal antimyosin antibody, Fab fragment

    International Nuclear Information System (INIS)

    Rezkalla, S.; Kloner, R.A.; Khaw, B.A.; Haber, E.; Fallon, J.T.; Smith, F.E.; Khatib, R.

    1989-01-01

    The purpose of this study was to determine whether monoclonal antimyosin Fab (antigen binding fragment) was capable of labeling hearts with experimental coxsackievirus myocarditis, and to determine whether Fab could be used for detecting myocardial damage in either early or chronic phases of the disease. Sixty-five, 3-week-old cesarean-derived 1 (CD 1) mice were divided into two groups: group I (noninfected animals) and group II (infected with coxsackievirus B3). Mice from each group were killed on days 7, 17, 30, or 90 of infection. Forty-eight hours before killing, mice were injected with monoclonal I-125 antimyosin, Fab (25 microCi/injection) and radioactivity was counted in the heart. Selected heart sections were also examined by autoradiography. Heart radioactivity, count/m/mg (m +/- SEM) on days 7, 17, 30, and 90 of infection was 10.8 +/- 1.7, 21.3 +/- 1.1, 11.2 +/- 3.4, and 12.4 +/- 1.5 for group I, versus 36.7 +/- 8.0 (p less than 0.01), 50.0 +/- 4.5 (p less than 0.001), 33.4 +/- 16.1 (p = NS), and 40.6 +/- 8.5 (p less than 0.01) for group II, respectively. Autoradiography revealed focal uptake within areas of necrotic myocardium. We conclude that I125 Fab may be useful in detecting myocardial damage in the experimental model of murine myocarditis up to day 90 of infection

  3. Radioimmunodetection of human tumor xenografts by monoclonal antibody F(ab')/sub 2/ fragments

    Energy Technology Data Exchange (ETDEWEB)

    Herlyn, D.; Munz, D.L.; Herlyn, M.; Koprowski, H.; Powe, J.; Alavi, A.; Meinken, G.E.; Srivastava, S.C.

    1986-01-01

    Procedures are described for the radiolocalization of human tumors by murine monoclonal antibodies (MAb) in animal model systems. Visualization of tumor xenografts was clearer in nude mice compared to experimentally immunosuppressed mice due to the higher tumor viability. MAb localization in tumor tissue was greatly enhanced when F(ab')/sub 2/ fragments rather than intact antibody molecules were used. Although tumors could be visualized with /sup 131/I-, /sup 123/I-or /sup 111/In-labeled MAb fragments without background subtraction, tumor-to-background ratios of radioactivity were highest for /sup 131/I-labeled fragments. /sup 131/I-labeled F(ab')/sub 2/ fragments of eight MAb against human colorectal carcinoma, melanoma or lung carcinoma localized specifically only in those tumors that bound the MAb in vitro and not in unrelated tumors. Radiolabeled fragments of MAb with other specificities (anti-hepatitis virus MAb) did not localize in tumors. All MAb that inhibited tumor growth in nude mice effectively localized these tumors by ..gamma..-scintigraphy. Some MAb were effective in localizing tumors but ineffective in inhibiting their growth. The ability of the specific radiolabeled F(ab')/sub 2/ fragments to localize in tumor grafts correlated significantly with MAb binding affinity and density of antigenic sites on tumor cells together, but not with either in vitro binding parameter alone.

  4. PET imaging of osteosarcoma in dogs using a fluorine-18-labeled monoclonal antibody fab fragment

    International Nuclear Information System (INIS)

    Page, R.L.; Garg, P.K.; Gard, S.

    1994-01-01

    Four dogs with histologically confirmed osteogenic sarcoma were studied with PET following intravenous injection of the 18 F-labeled Fab fragment of TP-3, a monoclonal antibody specific for human and canine osteosarcomas. The antibody fragment was labeled using the N-succinimidyl (8-(4'-( 18 F)fluorobenzyl)amino)suberate acylation agent. Blood clearance of activity was biphasic in all dogs but half-times were variable (T 1/2β = 2-13 hr). Catabolism of labeled Fab was reflected by the decrease in protein-associated activity in serum from more than 90% at 1 min to 60%-80% at 4 hr. PET images demonstrated increased accumulation of 18 F at the primary tumor site relative to normal contralateral bone in one dog as early as 15 min after injection. Biopsies obtained after euthanasia indicated higher uptake at the edges of the tumor as observed on the PET scans. Tumor uptake was 1-3 x 10 -3 % injected dose/g, a level similar to that reported for other Fab fragments in human tumors. In the three dogs with metastatic disease, early PET images reflected activity in the blood pool but later uptake was observed in suspected metastatic sites. These results, although preliminary, suggest that PET imaging of 18 F-labeled antibody fragments is feasible and that dogs with spontaneous tumors could be a valuable model for preclinical research with radioimmunoconjugates. 34 refs., 6 figs., 2 tabs

  5. PET imaging of osteosarcoma in dogs using a fluorine-18-labeled monoclonal antibody fab fragment

    Energy Technology Data Exchange (ETDEWEB)

    Page, R.L.; Garg, P.K.; Gard, S. [North Carolina State Univ., Raleigh, NC (United States)]|[Duke Univ. Medical Center, Durham, NC (United States)]|[North Carolina and Norke Radium Hospital, Oslo (Norway)] [and others

    1994-09-01

    Four dogs with histologically confirmed osteogenic sarcoma were studied with PET following intravenous injection of the {sup 18}F-labeled Fab fragment of TP-3, a monoclonal antibody specific for human and canine osteosarcomas. The antibody fragment was labeled using the N-succinimidyl (8-(4{prime}-({sup 18}F)fluorobenzyl)amino)suberate acylation agent. Blood clearance of activity was biphasic in all dogs but half-times were variable (T{sub 1/2{beta}} = 2-13 hr). Catabolism of labeled Fab was reflected by the decrease in protein-associated activity in serum from more than 90% at 1 min to 60%-80% at 4 hr. PET images demonstrated increased accumulation of {sup 18}F at the primary tumor site relative to normal contralateral bone in one dog as early as 15 min after injection. Biopsies obtained after euthanasia indicated higher uptake at the edges of the tumor as observed on the PET scans. Tumor uptake was 1-3 x 10{sup -3}% injected dose/g, a level similar to that reported for other Fab fragments in human tumors. In the three dogs with metastatic disease, early PET images reflected activity in the blood pool but later uptake was observed in suspected metastatic sites. These results, although preliminary, suggest that PET imaging of {sup 18}F-labeled antibody fragments is feasible and that dogs with spontaneous tumors could be a valuable model for preclinical research with radioimmunoconjugates. 34 refs., 6 figs., 2 tabs.

  6. Characterization of a recombinant humanized anti-cocaine monoclonal antibody and its Fab fragment.

    Science.gov (United States)

    Kirley, Terence L; Norman, Andrew B

    2015-01-01

    Variations of post-translational modifications are important for stability and in vivo behavior of therapeutic antibodies. A recombinant humanized anti-cocaine monoclonal antibody (h2E2) was characterized for heterogeneity of N-linked glycosylation and disulfide bonds. In addition, charge heterogeneity, which is partially due to the presence or absence of C-terminal lysine on the heavy chains, was examined. For cocaine overdose therapy, Fab fragments may be therapeutic, and thus, a simplified method of generation, purification, and characterization of the Fab fragment generated by Endoproteinase Lys-C digestion was devised. Both the intact h2E2 antibody and purified Fab fragments were analyzed for their affinities for cocaine and 2 of its metabolites, benzoylecgonine and cocaethylene, by fluorescence quenching of intrinsic antibody tyrosine and tryptophan fluorescence resulting from binding of these drugs. Binding constants obtained from fluorescence quenching measurements are in agreement with recently published radioligand and ELISA binding assays. The dissociation constants determined for the h2E2 monoclonal and its Fab fragment are approximately 1, 5, and 20 nM for cocaethylene, cocaine, and benzoylecgonine, respectively. Tryptophan fluorescence quenching (emission at 330 nm) was measured after either excitation of tyrosine and tryptophan (280 nm) or selective excitation of tryptophan alone (295 nm). More accurate binding constants are obtained using tryptophan selective excitation at 295 nm, likely due to interfering absorption of cocaine and metabolites at 280 nm. These quenching results are consistent with multiple tryptophan and tyrosine residues in or near the predicted binding location of cocaine in a previously published 3-D model of this antibody's variable region.

  7. Construction and sequencing analysis of scFv antibody fragment derived from monoclonal antibody against norfloxacin (Nor155

    Directory of Open Access Journals (Sweden)

    J. Mala

    2017-06-01

    Full Text Available Norfloxacin belongs to the group of fluoroquinolone antibiotics which has been approved for treatment in animals. However, its residues in animal products can pose adverse side effects to consumer. Therefore, detection of the residue in different food matrices must be concerned. In this study, a single chain variable fragment (scFv that recognizes norfloxacin antibiotic was constructed. The cDNA was synthesized from total RNA of hybridoma cells against norfloxacin. Genes encoding VH and VL regions of monoclonal antibody against norfloxacin (Nor155 were amplified and size of VH and VL fragments was 402 bp and 363 bp, respectively. The scFv of Nor155 was constructed by an addition of (Gly4Ser3 as a linker between VH and VL regions and subcloned into pPICZαA, an expression vector of Pichia pastoris. The sequence of scFv Nor155 (GenBank No. AJG06891.1 was confirmed by sequencing analysis. The complementarity determining regions (CDR I, II, and III of VH and VL were specified by Kabat method. The obtained recombinant plasmid will be useful for production of scFv antibody against norfloxacin in P. pastoris and further engineer scFv antibody against fluoroquinolone antibiotics.

  8. Tumour targeting with monovalent fragments of anti-neuroblastoma antibody chCE7

    International Nuclear Information System (INIS)

    Carrel, F.; Novak-Hofer, I.; Ruch, C.; Zimmermann, K.; Amstutz, H.

    1997-01-01

    The in vitro and in vivo behaviour of the monovalent single chain (scFv) and Fab-fragments derived from anti-neuroblastoma antibody chCE7 is reported. When comparing tumour uptake and -retention of radioactivity of 67 Cu-labelled monovalent chCE7 with divalent chCE7 F(ab') 2 the advantage of the radiocopper label over the radioiodine label was more pronounced with the divalent (internalising) F(ab') 2 fragments. (author) 1 fig., 1 ref

  9. Application of 99mTc-labeled chimeric Fab fragments of monoclonal antibody A7 for radioimmunoscintigraphy of pancreatic cancer

    International Nuclear Information System (INIS)

    Matsumura, Hiroomi

    1999-01-01

    Pancreatic cancer is one of the most lethal diseases and its prognosis is still poor. To improve the survival rate, it is essential to develop new technologies for early and definitive diagnosis. In this study, chimeric Fab fragments of monoclonal antibody A7 were successfully radio-labeled with 99m Tc, preventing depression of the antigen-binding activity. 99m Tc-labeled monoclonal antibody A7, 99m Tc-labeled chimeric Fab fragments of monoclonal antibody A7, 99m Tc-labeled normal mouse IgG and 99m Tc-labeled Fab fragments of normal mouse IgG were injected intravenously into nude mice bearing human pancreatic cancer xenografts and the radioactivity was subsequently measured. The tumor accumulation was significantly higher with labeled monoclonal antibody A7 than with normal mouse IgG, and higher with chimeric Fab fragments of monoclonal antibody A7 than with Fab fragments of normal mouse IgG. The tumor/blood ratio of radioactivity increased rapidly over time with chimeric Fab fragments of monoclonal antibody A7. These results suggest that chimeric Fab fragments of monoclonal antibody A7 may be useful for diagnosing pancreatic cancer by means of radioimmunoscintigraphy. (author)

  10. Multifunctional PSCA antibody fragments for PET and optical prostate cancer imaging

    Science.gov (United States)

    2017-10-01

    that recognize PSCA (prostate stem cell antigen), a cell surface protein highly expressed in prostate cancer. These engineered antibody fragments...operatively. Prostate stem cell antigen (PSCA) is a cell - surface marker overexpressed in primary and metastatic cancers1. In vivo administration of...REPORT: Annual PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT

  11. Nebulized Anti-IL-13 Monoclonal Antibody Fab' Fragment Reduces Allergen-Induced Asthma

    OpenAIRE

    Hacha, Jonathan; Tomlinson, K; Maertens, Ludovic; Paulissen, Geneviève; Rocks, Natacha; Foidart, Jean-Michel; Noël, Agnès; Palframan, R; Guéders, Maud; Cataldo, Didier

    2012-01-01

    Rationale: Interleukin-13 (IL-13) is a prototypic Th2 cytokine and a central mediator of the complex cascade of events leading to asthmatic phenotype. Indeed, IL-13 plays key roles in IgE synthesis, bronchial hyperresponsiveness, mucus hypersecretion, subepithelial fibrosis and eosinophil infiltration. Objectives: We assessed the potential efficacy of inhaled anti-IL-13 monoclonal antibody Fab' fragment on allergen-induced airway inflammation, hyperresponsiveness and remodeling in an experime...

  12. Radioimmunoimaging using F(ab')2 fragment of monoclonal antibodies against human alpha-fetoprotein

    International Nuclear Information System (INIS)

    Sakahara, Harumi; Endo, Keigo; Nakashima, Tetsuo; Koizumi, Mitsuru; Ohta, Hitoya; Torizuka, Kanji; Okada, Kenichiro; Yoshida, Osamu; Nishi, Shinzo.

    1985-01-01

    Using monoclonal antibodies against human α-fetoprotein (AFP), radioiodinated F(ab') 2 fragments were compared with whole IgG as a radiotracer for radioimmunoimaging of cancer. F(ab') 2 fragments were obtained by pepsin digestion of whole IgG (IgGl). IgG and F(ab') 2 were labeled with 125 I or 131 I by the chloramine-T method with almost full retention of antibody activity. F(ab') 2 fragments were cleared more rapidly from the circulation in normal mice with a half life of 6.3 hours than whole IgG with a half life of 5.5 days. Radioactivity of F(ab') 2 in various organs also decreased faster than IgG. In nude mice transplanted with AFP-producing human testicular tumor, F(ab') 2 fragments demonstrated superior scintigrams to whole IgG at 2 days after the injection, because of the fast disappearance of background radioactivity. Although absolute accumulation of 131 I labeled F(ab') 2 in the tumor was less than that of 131 I labeled IgG, tumor to other organ ratios were much higher with F(ab') 2 than those of IgG. The tumor to blood ratio of 131 I labeled F(ab') 2 was 1.04 at day 2, whereas tumor to blood ratio of 131 I labeled IgG was 0.55 at day 2 and 0.92 at day 4, respectively. These results indicated that for the radiolabeling of monoclonal antibodies, F(ab') 2 fragments would be superior to whole IgG in the radioimmunoimaging of cancer. (author)

  13. Use of flow cytometry to identify monoclonal antibodies that recognize conserved epitopes on orthologous leukocyte differentiation antigens in goats, llamas, and rabbits

    Czech Academy of Sciences Publication Activity Database

    Davis, W. C.; Drbal, Karel; El-Aziz, A.; Mosaad, A.E.; Elbagory, A.R.M.; TIbary, A.; Barrington, G.M.; Park, Y.H.; Hamilton, M.J.

    2007-01-01

    Roč. 119, 1-2 (2007), s. 123-130 ISSN 0165-2427 Institutional research plan: CEZ:AV0Z50520514 Keywords : flow cytometry * monoclonal antibodies * leukocytes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.957, year: 2007

  14. Efficient production of Trastuzumab Fab antibody fragments in Brevibacillus choshinensis expression system.

    Science.gov (United States)

    Mizukami, Makoto; Onishi, Hiromasa; Hanagata, Hiroshi; Miyauchi, Akira; Ito, Yuji; Tokunaga, Hiroko; Ishibashi, Matsujiro; Arakawa, Tsutomu; Tokunaga, Masao

    2018-10-01

    The Brevibacillus expression system has been successfully employed for the efficient productions of a variety of recombinant proteins, including enzymes, cytokines, antigens and antibody fragments. Here, we succeeded in secretory expression of Trastuzumab Fab antibody fragments using B. choshinensis/BIC (Brevibacillus in vivocloning) expression system. In the fed-batch high-density cell culture, recombinant Trastuzumab Fab with amino-terminal His-tag (His-BcFab) was secreted at high level, 1.25 g/liter, and Fab without His-tag (BcFab) at ∼145 mg/L of culture supernatant. His-BcFab and BcFab were purified to homogeneity using combination of conventional column chromatographies with a yield of 10-13%. This BcFab preparation exhibited native structure and functions evaluated by enzyme-linked immunosorbent assay, surface plasmon resonance, circular dichroism measurements and size exclusion chromatography. To our knowledge, this is the highest production of Fab antibody fragments in gram-positive bacterial expression/secretion systems. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Use of an anti-platelet monoclonal antibody F (ab')2 fragment for imaging thrombus

    International Nuclear Information System (INIS)

    Loutfi, I.; Stuttle, A.W.J.; Peters, A.M.; George, P.; Lavender, J.P.; Lumley, P.

    1990-01-01

    Ten patients with suspected thrombus have been studied using 111 In-labelled F (ab')2 fragments of P256, a monoclonal antibody which recognizes an epitope on the platelet membrane glycoprotein IIb/IIIa complex. The F (ab')2 fragment was radiolabelled with 111 In via diethylenetri-aminepentamacetic acid to give a specific activity of up to 190 MBq (5mCi) mg - 1 without impairment of immunoreactivity. In vitro platelet aggregation studies showed that the F (ab')2 fragment caused less platelet aggregation than the whole antibody on a molar ratio and was without significant effect upon the sensitivity of platelets to a range of aggregating agents. Platalets were labelled in ten patients by intravenous injection of approximately 100 μg P256 F (ab')2. Of the ten patients studies, six showed localization of activity consistent with platelet accumulation. Localization was clearly seen when associated with thrombus of the lower limbs (three patients: deep vein thrombosis; one patient: aortofemoral graft), and was apparent although less marked in two other cases, one of aortic aneurysm and one of carotid stenosis. Use of radiolabelled P256 F (ab')2 offers a means of non-invasive detection of thrombus which, from in vitro studies, would appear to have less direct effect of platelet behaviour than the whole antibody. (author). 9 refs. 8 figs. 1 tab

  16. 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.

  17. 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.

  18. Monoclonal antibodies from rats immunized with fragment D of human fibrinogen

    International Nuclear Information System (INIS)

    Kennel, S.J.; Chen, J.P.; Lankford, P.K.; Foote, L.J.

    1981-01-01

    Fischer rats were immunized with fragment D (Fg-D) of human fibrinogen (Fg) to obtain antibody specific for neoantigens unique to this molecule. Absorption of serum with whole Fg indicated that some of the antibody produced reacted preferentially with Fg-D. Hybridoma cultures were prepared by fusion of immune rat spleen cells with mouse myeloma P3-X63-Ag8. Monoclonal antibodies obtained from these cultures fell into two classes: (a) Those reacting equally well with Fg and Fg-D. (b) Those reacting preferentially but not absolutely wth Fg-D. Antibody from hybridoma 104-14, a member of the first group had an affinity for Fg-D of 1.5 x 10 9 M -1 while antibodies from 106-59 and 106-71 (group 2) demonstrated much lower affinities of 1.0 x 10 7 and 4.7 x 10 6 M -1 , respectively. The cross reactivity of antibodies in the second group indicated that they react with protein conformations that are altered during production of Fg-D from Fg

  19. Cross-Reactivity of Polyclonal Antibodies against Canavalia ensiformis (Jack Bean) Urease and Helicobacter pylori Urease Subunit A Fragments.

    Science.gov (United States)

    Kaminski, Zbigniew Jerzy; Relich, Inga; Konieczna, Iwona; Kaca, Wieslaw; Kolesinska, Beata

    2018-01-01

    Overlapping decapeptide fragments of H. pylori urease subunit A (UreA) were synthesized and tested with polyclonal antibodies against Canavalia ensiformis (Jack bean) urease. The linear epitopes of UreA identified using the dot blot method were then examined using epitope mapping. For this purpose, series of overlapping fragments of UreA, frameshifted ± four amino acid residues were synthesized. Most of the UreA epitopes which reacted with the Jack bean urease polyclonal antibodies had been recognized in previous studies by monoclonal antibodies against H. pylori urease. Fragments 11 - 24, 21 - 33, and 31 - 42 were able to interact with the Jack bean urease antibodies, giving stable immunological complexes. However, the lack of recognition by these antibodies of all the components in the peptide map strongly suggests that a non-continuous (nonlinear) epitope is located on the N-terminal domain of UreA. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  20. Human antibody fragments specific for Bothrops jararacussu venom reduce the toxicity of other Bothrops sp. venoms.

    Science.gov (United States)

    Roncolato, Eduardo Crosara; Pucca, Manuela Berto; Funayama, Jaqueline Carlos; Bertolini, Thaís Barboza; Campos, Lucas Benício; Barbosa, José Elpidio

    2013-01-01

    Approximately 20,000 snakebites are registered each year in Brazil. The classical treatment for venomous snakebite involves the administration of sera obtained from immunized horses. Moreover, the production and care of horses is costly, and the use of heterologous sera can cause hypersensitivity reactions. The production of human antibody fragments by phage display technology is seen as a means of overcoming some of these disadvantages. The studies here attempted to test human monoclonal antibodies specific to Bothrops jararacussu against other Bothrops sp. venoms, using the Griffin.1 library of human single-chain fragment-variable (scFv) phage antibodies. Using the Griffin.1 phage antibody library, this laboratory previously produced scFvs capable of inhibiting the phospholipase and myotoxic activities of Bothrops jararacussu venom. The structural and functional similarities of the various forms of phospholipase A2 (PLA₂) in Bothrops venom served as the basis for the present study wherein the effectiveness of those same scFvs were evaluated against B. jararaca, B. neuwiedi, and B. moojeni venoms. Each clone was found to recognize all three Bothrops venoms, and purified scFvs partially inhibited their in vitro phospholipase activity. In vivo assays demonstrated that the scFv clone P2B7 reduced myotoxicity and increased the survival of animals that received the test venoms. The results here indicate that the scFv P2B7 is a candidate for inclusion in a mixture of specific antibodies to produce a human anti-bothropic sera. This data demonstrates that the human scFv P2B7 represents an alternative therapeutic approach to heterologous anti-bothropic sera available today.

  1. Evaluation of tumor targeting with radiolabeled F(ab2 fragment of a humanized monoclonal antibody

    Directory of Open Access Journals (Sweden)

    "Babaei MH

    2002-08-01

    Full Text Available Humanized monoclonal antibody U36 and its F(ab'2 fragment, radio labeled with 125I, were tested for tumor localization in nude mice bearing a squamous cell carcinoma xenograft line derived from a head and neck carcinoma. Monoclonal antibody IgG or F(ab'2 fragment were injected in parallel and at days 1, 2 and 3, mice were dissected for determination of isotope biodistribution. IgG as well as F(ab'2 showed highly specific localization in tumor tissue. The mean tumor uptake (n=3 is expressed as the percentage of the injected dose per gram of tumor tissue (%ID/g. %ID/g of IgG was 11.7% at day 1 and decreased to 10.9% at day 3 whereas %ID/g of F(ab'2 was 2.9% at day 1 and decreased on following days. Tumor to blood ratios (T/B at day 1 were 0.86 for IgG and 1.32 for F(ab'2 and reached a maximum at day 3 with values of 4.41 and 1.84 respectively. These findings suggest that the superior tumor to non-tumor ratios in the day of 1 render the F(ab'2 fragment more qualified for specific targeting radioisotopes to tumor xenografts in this exprimental setting.

  2. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix.

    Science.gov (United States)

    Liang, Hui; Li, Xiaoran; Wang, Bin; Chen, Bing; Zhao, Yannan; Sun, Jie; Zhuang, Yan; Shi, Jiajia; Shen, He; Zhang, Zhijun; Dai, Jianwu

    2016-02-17

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of cetuximab was fused with CBD (CBD-Fab) and expressed in Pichia pastoris. CBD-Fab maintained antigen binding and anti-tumor activity of cetuximab and obtained a collagen-binding ability in vitro. The results also showed CBD-Fab was mainly enriched in tumors and had longer retention time in tumors in A431 s.c. xenografts. Furthermore, CBD-Fab showed a similar therapeutic efficacy as cetuximab in A431 xenografts. Although CBD-Fab hasn't showed better therapeutic effects than cetuximab, its smaller molecular and special target may be applicable as antibody-drug conjugates (ADC) or immunotoxins.

  3. T cell receptor-like recognition of tumor in vivo by synthetic antibody fragment.

    Directory of Open Access Journals (Sweden)

    Keith R Miller

    Full Text Available A major difficulty in treating cancer is the inability to differentiate between normal and tumor cells. The immune system differentiates tumor from normal cells by T cell receptor (TCR binding of tumor-associated peptides bound to Major Histocompatibility Complex (pMHC molecules. The peptides, derived from the tumor-specific proteins, are presented by MHC proteins, which then serve as cancer markers. The TCR is a difficult protein to use as a recombinant protein because of production issues and has poor affinity for pMHC; therefore, it is not a good choice for use as a tumor identifier outside of the immune system. We constructed a synthetic antibody-fragment (Fab library in the phage-display format and isolated antibody-fragments that bind pMHC with high affinity and specificity. One Fab, fE75, recognizes our model cancer marker, the Human Epidermal growth factor Receptor 2 (HER2/neu peptide, E75, bound to the MHC called Human Leukocyte Antigen-A2 (HLA-A2, with nanomolar affinity. The fE75 bound selectively to E75/HLA-A2 positive cancer cell lines in vitro. The fE75 Fab conjugated with (64Cu selectively accumulated in E75/HLA-A2 positive tumors and not in E75/HLA-A2 negative tumors in an HLA-A2 transgenic mouse as probed using positron emission tomography/computed tomography (PET/CT imaging. Considering that hundreds to thousands of different peptides bound to HLA-A2 are present on the surface of each cell, the fact that fE75 arrives at the tumor at all shows extraordinary specificity. These antibody fragments have great potential for diagnosis and targeted drug delivery in cancer.

  4. Efficient production of antibody Fab fragment by transient gene expression in insect cells.

    Science.gov (United States)

    Mori, Keita; Hamada, Hirotsugu; Ogawa, Takafumi; Ohmuro-Matsuyama, Yuki; Katsuda, Tomohisa; Yamaji, Hideki

    2017-08-01

    Transient gene expression allows a rapid production of diverse recombinant proteins in early-stage preclinical and clinical developments of biologics. Insect cells have proven to be an excellent platform for the production of functional recombinant proteins. In the present study, the production of an antibody Fab fragment by transient gene expression in lepidopteran insect cells was investigated. The DNA fragments encoding heavy-chain (Hc; Fd fragment) and light-chain (Lc) genes of an Fab fragment were individually cloned into the plasmid vector pIHAneo, which contained the Bombyx mori actin promoter downstream of the B. mori nucleopolyhedrovirus (BmNPV) IE-1 transactivator and the BmNPV HR3 enhancer for high-level expression. Trichoplusia ni BTI-TN-5B1-4 (High Five) cells were co-transfected with the resultant plasmid vectors using linear polyethyleneimine. When the transfection efficiency was evaluated, a plasmid vector encoding an enhanced green fluorescent protein (EGFP) gene was also co-transfected. Transfection and culture conditions were optimized based on both the flow cytometry of the EGFP expression in transfected cells and the yield of the secreted Fab fragments determined by enzyme-linked immunosorbent assay (ELISA). Under optimal conditions, a yield of approximately 120 mg/L of Fab fragments was achieved in 5 days in a shake-flask culture. Transient gene expression in insect cells may offer a promising approach to the high-throughput production of recombinant proteins. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Locking the Elbow: Improved Antibody Fab Fragments as Chaperones for Structure Determination.

    Science.gov (United States)

    Bailey, Lucas J; Sheehy, Kimberly M; Dominik, Pawel K; Liang, Wenguang G; Rui, Huan; Clark, Michael; Jaskolowski, Mateusz; Kim, Yejoon; Deneka, Dawid; Tang, Wei-Jen; Kossiakoff, Anthony A

    2018-02-02

    Antibody Fab fragments have been exploited with significant success to facilitate the structure determination of challenging macromolecules as crystallization chaperones and as molecular fiducial marks for single particle cryo-electron microscopy approaches. However, the inherent flexibility of the "elbow" regions, which link the constant and variable domains of the Fab, can introduce disorder and thus diminish their effectiveness. We have developed a phage display engineering strategy to generate synthetic Fab variants that significantly reduces elbow flexibility, while maintaining their high affinity and stability. This strategy was validated using previously recalcitrant Fab-antigen complexes where introduction of an engineered elbow region enhanced crystallization and diffraction resolution. Furthermore, incorporation of the mutations appears to be generally portable to other synthetic antibodies and may serve as a universal strategy to enhance the success rates of Fabs as structure determination chaperones. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Subcellular localization of estradiol receptor in MCF7 cells studied with nanogold-labelled antibody fragments.

    Science.gov (United States)

    Kessels, M M; Qualmann, B; Thole, H H; Sierralta, W D

    1998-01-01

    Ultrastructural localization studies of estradiol receptor in hormone-deprived and hormone-stimulated MCF7 cells were done using F(ab') fragments of three different antibodies (#402, 13H2, HT277) covalently linked to nanogold. These ultra-small, non-charged immunoreagents, combined with a size-enlargement by silver enhancement, localized estradiol receptor in both nuclear and cytoplasmic areas of non-stimulated target cells; stimulation with the steroid induced a predominantly nuclear labelling. In the cytoplasm of resting cells, tagging was often observed at or in the proximity of stress fibers. In the nucleus a large proportion of receptor was found inside the nucleolus, specially with the reagent derived from antibody 13H2. We postulate that different accessibilities of receptor epitopes account for the different labelling densities observed at cytoskeletal elements and the nucleoli.

  7. [Preparation of monoclonal antibody against 4-amylphenol and homology modeling of its Fv fragment].

    Science.gov (United States)

    Cheng, Lei; Wu, Haizhen; Fei, Jing; Zhang, Lujia; Ye, Jiang; Zhang, Huizhan

    2017-03-01

    Objective To prepare and characterize a monoclonal antibody (mAb) against 4-amylphenol (4-AP), clone its cDNA sequence and make homology modeling for its Fv fragment. Methods A high-affinity anti-4-AP mAb was generated from a hybridoma cell line F10 using electrofusion between splenocytes from APA-BSA-immunized mouse and Sp2/0 myeloma cells. Then we extracted the mRNA of F10 cells and cloned the cDNA of mAb. The homology modeling and molecular docking of its Fv fragment was conducted with biological software. Results Under the optimum conditions, the ic-ELISA equation was y=A 2 +(A 1 -A 2 )/(1+(x/x 0 ) p ) (A 1 =1.28; A 2 =-0.066; x 0 =12560.75; p=0.74) with a correlation coefficient (R 2 ) of 0.997. The lowest detectable limit was 0.65 μg/mL. The heavy and light chains of mAb respectively belonged to IgG1 and Kappa. The homology modeling and molecular docking studies revealed that the binding of 4-Ap and mAb was attributed to the hydrogen bond and hydrophobic interactions. Conclusion The study successfully established a stable 4-AP mAb-secreting hybridoma cell line. The study on spatial structure of Fv fragment using homology modeling provided a reference for the development and design of single chain variable fragments.

  8. In vivo tumor targeting and imaging with engineered trivalent antibody fragments containing collagen-derived sequences.

    Directory of Open Access Journals (Sweden)

    Angel M Cuesta

    Full Text Available There is an urgent need to develop new and effective agents for cancer targeting. In this work, a multivalent antibody is characterized in vivo in living animals. The antibody, termed "trimerbody", comprises a single-chain antibody (scFv fragment connected to the N-terminal trimerization subdomain of collagen XVIII NC1 by a flexible linker. As indicated by computer graphic modeling, the trimerbody has a tripod-shaped structure with three highly flexible scFv heads radially outward oriented. Trimerbodies are trimeric in solution and exhibited multivalent binding, which provides them with at least a 100-fold increase in functional affinity than the monovalent scFv. Our results also demonstrate the feasibility of producing functional bispecific trimerbodies, which concurrently bind two different ligands. A trimerbody specific for the carcinoembryonic antigen (CEA, a classic tumor-associated antigen, showed efficient tumor targeting after systemic administration in mice bearing CEA-positive tumors. Importantly, a trimerbody that recognizes an angiogenesis-associated laminin epitope, showed excellent tumor localization in several cancer types, including fibrosarcomas and carcinomas. These results illustrate the potential of this new antibody format for imaging and therapeutic applications, and suggest that some laminin epitopes might be universal targets for cancer targeting.

  9. Comparative imaging and biodistribution studies with an anti-CEA monoclonal antibody and its F(ab)2 and Fab fragments in mice with colon carcinoma xenografts

    International Nuclear Information System (INIS)

    Andrew, S.M.; Pimm, M.V.; Baldwin, R.W.; Perkins, A.C.

    1986-01-01

    An IgG1 mouse monoclonal antibody directed against CEA has been digested with papain to yield F(ab) 2 and Fab fragments. Following radioiodination, intact antibody and fragments showed specific binding to cells of a CEA-producing tumour, although the immune reactivities of the fragments were lower than that of intact antibody. Gamma scintigraphy of nude mice bearing CEA producing human tumour xenografts and injected with 131 I-labelled fragments showed earlier and superior imaging of tumours than did 131 I-intact antibody, and this was most marked with the Fab fragment. Sequential dissection analyses showed that this was due to earlier and higher tumour-to-blood ratios with fragments than with intact antibody, but in absolute terms the degree of localization of both fragment types was significantly lower than that of intact antibody. (orig.)

  10. Immobilization and functional reconstitution of antibody Fab fragment by solid-phase refolding.

    Science.gov (United States)

    Kumada, Yoichi; Hamasaki, Kyoto; Nakagawa, Aya; Sasaki, Eiju; Shirai, Tatsunori; Okumura, Masahiro; Inoue, Manami; Kishimoto, Michimasa

    2013-12-31

    In this study, we demonstrated the successful preparation of a Fab antibody-immobilized hydrophilic polystyrene (phi-PS) plate via one- and two-step solid-phase refolding methods. Both polystyrene-binding peptide (PS-tag)-fused Fd fragment of heavy chain (Fab H-PS) and full-length of light-chain (Fab L-PS) were individually produced in insoluble fractions of Escherichia coli cells, and they were highly purified in the presence of 8M of urea. Antigen-binding activities of Fab antibody immobilized were correctly recovered by the one-step solid-phase refolding method that a mixture of Fab H-PS and Fab L-PS was immobilized in the presence of 0.5-2M urea, followed by surface washing of the phi-PS plate with PBST. These results indicate that by genetic fusion of a PS-tag, a complex between Fab H and Fab L was efficiently immobilized on the surface of a phi-PS plate even in the presence of a low concentration of urea, and was then correctly refolded to retain its high antigen-binding activity via removal of the urea. A two-step solid-phase refolding method whereby Fab H-PS and Fab L-PS were successively refolded on the surface of a phi-PS plate also resulted in Fab antibody formation on the plate. Furthermore, both the binding affinity and the specificity of the Fab antibody produced by the two-step method were highly maintained, according to the results of sandwich ELISA and competitive ELISA using Fab antibody-immobilized plate via two-step solid-phase refolding. Thus, the solid-phase refolding method demonstrated in this study should be quite useful for the preparation of a Fab antibody-immobilized PS surface with high efficiency from individually produced Fab H-PS and Fab L-PS. This method will be applicable to the preparation of a large Fab antibody library on the surface of a PS plate for use in antibody screening. © 2013. Published by Elsevier B.V. All rights reserved.

  11. Localization of tumors in vivo by scintigraphic identification of Clostridium butyricum using 131I-labelled antibodies and F(ab')2-antibody fragments

    International Nuclear Information System (INIS)

    Vogt, R.; Mehnert, W.H.; Schmidt, H.E.; Altenbrunn, H.J.; Akademie der Wissenschaften der DDR, Berlin-Buch. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1979-01-01

    Tumor-bearing mice injected with clostridial spores show enrichment and germination of the spores within the tumor. 131 I-labelled anti-Clostridium-antibodies and anti-Clostridium-F(ab') 2 -fragments were used for a possible localization of tumors in vivo by scintiscanning. The application of the antibody revealed increased radioactivity in the tumors of mice pretreated with spores as well as in animals without pretreatment. In using F(ab') 2 -fragments instead of total antibody neither the apparently unspecific increase of radioactivity in not pretreated mice nor the specific fixation of labelled F(ab') 2 -fragments to clostridial rods in the tumors of pretreated animals could be demonstrated. The results are discussed with respect to further investigation

  12. Evaluation of selectivity in homologous multimodal chromatographic systems using in silico designed antibody fragment libraries.

    Science.gov (United States)

    Karkov, Hanne Sophie; Woo, James; Krogh, Berit Olsen; Ahmadian, Haleh; Cramer, Steven M

    2015-12-24

    This study describes the in silico design, surface property analyses, production and chromatographic evaluations of a diverse set of antibody Fab fragment variants. Based on previous findings, we hypothesized that the complementarity-determining regions (CDRs) constitute important binding sites for multimodal chromatographic ligands. Given that antibodies are highly diversified molecules and in particular the CDRs, we set out to examine the generality of this result. For this purpose, four different Fab fragments with different CDRs and/or framework regions of the variable domains were identified and related variants were designed in silico. The four Fab variant libraries were subsequently generated by site-directed mutagenesis and produced by recombinant expression and affinity purification to enable examination of their chromatographic retention behavior. The effects of geometric re-arrangement of the functional moieties on the multimodal resin ligands were also investigated with respect to Fab variant retention profiles by comparing two commercially available multimodal cation-exchange ligands, Capto MMC and Nuvia cPrime, and two novel multimodal ligand prototypes. Interestingly, the chromatographic data demonstrated distinct selectivity trends between the four Fab variant libraries. For three of the Fab libraries, the CDR regions appeared as major binding sites for all multimodal ligands. In contrast, the fourth Fab library displayed a distinctly different chromatographic behavior, where Nuvia cPrime and related multimodal ligand prototypes provided markedly improved selectivity over Capto MMC. Clearly, the results illustrate that the discriminating power of multimodal ligands differs between different Fab fragments. The results are promising indications that multimodal chromatography using the appropriate multimodal ligands can be employed in downstream bioprocessing for challenging selective separation of product related variants. Copyright © 2015 Elsevier B

  13. Association of Circulating Transfer RNA fragments with antibody response to Mycoplasma bovis in beef cattle.

    Science.gov (United States)

    Casas, Eduardo; Cai, Guohong; Kuehn, Larry A; Register, Karen B; McDaneld, Tara G; Neill, John D

    2018-03-13

    High throughput sequencing allows identification of small non-coding RNAs. Transfer RNA Fragments are a class of small non-coding RNAs, and have been identified as being involved in inhibition of gene expression. Given their role, it is possible they may be involved in mediating the infection-induced defense response in the host. Therefore, the objective of this study was to identify 5' transfer RNA fragments (tRF5s) associated with a serum antibody response to M. bovis in beef cattle. The tRF5s encoding alanine, glutamic acid, glycine, lysine, proline, selenocysteine, threonine, and valine were associated (P < 0.05) with antibody response against M. bovis. tRF5s encoding alanine, glutamine, glutamic acid, glycine, histidine, lysine, proline, selenocysteine, threonine, and valine were associated (P < 0.05) with season, which could be attributed to calf growth. There were interactions (P < 0.05) between antibody response to M. bovis and season for tRF5 encoding selenocysteine (anticodon UGA), proline (anticodon CGG), and glutamine (anticodon TTG). Selenocysteine is a rarely used amino acid that is incorporated into proteins by the opal stop codon (UGA), and its function is not well understood. Differential expression of tRF5s was identified between ELISA-positive and negative animals. Production of tRF5s may be associated with a host defense mechanism triggered by bacterial infection, or it may provide some advantage to a pathogen during infection of a host. Further studies are needed to establish if tRF5s could be used as a diagnostic marker of chronic exposure.

  14. Anti-coagulation effect of Fc fragment against anti-β2-GP1 antibodies in mouse models with APS.

    Science.gov (United States)

    Xie, Weidong; Zhang, Yaou; Bu, Cunya; Sun, Shijing; Hu, Shaoliang; Cai, Guoping

    2011-01-01

    Anti-beta (2)-glycoprotein I (anti-β2-GP1) is one of the important pathogenesis factors responsible for thrombosis formation in patients with antiphospholipid syndrome (APS). Administration of intravenous immunoglobulin (IVIg) is a common method used to inhibit the abnormal antibody levels and decrease the mortality of APS in emergency situations. We hypothesize that the Fc fragment of IgG is the molecular structure responsible for these effects. The present study investigates the beneficial effects of both recombinant and natural human Fc fragments of heterogeneous IgG against human anti-β2-GP1 antibodies in mouse models with APS. Results showed that both recombinant and natural human Fc fragments moderately but significantly decreased the levels of serum anti-β2-GP1 antibodies and had anti-coagulation effects in human β2-GP1-immunized mice. Furthermore, both recombinant and natural human Fc fragments inhibited thrombosis formation and decreased mortality in mouse models infused intravenously with human anti-β2GP1 antibodies from patients with APS. Findings suggest that the Fc fragment might be one of the active structural units of heterogeneous IgG. Thus, recombinant human Fc fragment administration may be a useful treatment for individuals with APS. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Shark Variable New Antigen Receptor (VNAR Single Domain Antibody Fragments: Stability and Diagnostic Applications

    Directory of Open Access Journals (Sweden)

    Stewart Nuttall

    2013-01-01

    Full Text Available The single variable new antigen receptor domain antibody fragments (VNARs derived from shark immunoglobulin new antigen receptor antibodies (IgNARs represent some of the smallest known immunoglobulin-based protein scaffolds. As single domains, they demonstrate favorable size and cryptic epitope recognition properties, making them attractive in diagnosis and therapy of numerous disease states. Here, we examine the stability of VNAR domains with a focus on a family of VNARs specific for apical membrane antigen 1 (AMA-1 from Plasmodium falciparum. The VNARs are compared to traditional monoclonal antibodies (mAbs in liquid, lyophilized and immobilized nitrocellulose formats. When maintained in various formats at 45 °C, VNARs have improved stability compared to mAbs for periods of up to four weeks. Using circular dichroism spectroscopy we demonstrate that VNAR domains are able to refold following heating to 80 °C. We also demonstrate that VNAR domains are stable during incubation under potential in vivo conditions such as stomach acid, but not to the protease rich environment of murine stomach scrapings. Taken together, our results demonstrate the suitability of shark VNAR domains for various diagnostic platforms and related applications.

  16. [Molecular dynamics of immune complex of photoadduct-containing DNA with Fab-Anti-DNA antibody fragment].

    Science.gov (United States)

    Akberova, N I; Zhmurov, A A; Nevzorova, T A; Litvinov, R I

    2016-01-01

    Antibodies to DNA play an important role in the pathogenesis of autoimmune diseases. The elucidation of structural mechanisms of both the antigen recognition and the interaction of anti-DNA antibodies with DNA will help to understand the role of DNA-containing immune complexes in various pathologies and can provide a basis for new treatment modalities. Moreover, the DNA-antibody complex is an analog of specific intracellular DNA-protein interactions. In this work, we used in silico molecular dynamic simulations of bimolecular complexes of the dsDNA segment containing the Fab fragment of an anti-DNA antibody to obtain the detailed thermodynamic and structural characteristics of dynamic intermolecular interactions. Using computationally modified crystal structure of the Fab-DNA complex (PDB ID: 3VW3), we studied the equilibrium molecular dynamics of the 64M-5 antibody Fab fragment associated with the dsDNA fragment containing the thymine dimer, the product of DNA photodamage. Amino acid residues that constitute paratopes and the complementary nucleotide epitopes for the Fab-DNA construct were identified. Stacking and electrostatic interactions were found to play the main role in mediating the most specific antibody-dsDNA contacts, while hydrogen bonds were less significant. These findings may shed light on the formation and properties of pathogenic anti-DNA antibodies in autoimmune diseases, such as systemic lupus erythematosus associated with skin photosensitivity and DNA photodamage.

  17. 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.

  18. ECT with /sup 123/I-labeled fragments of anti-CEA monoclonal antibodies in colo-rectal cancer

    International Nuclear Information System (INIS)

    Bischof-Delaloye, A.; Delaloye, B.

    1986-01-01

    The recent progress of tumor localization with labelled antibodies can be attributed to three techniques: 1) use of I-123 as a label; 2) fragmentation of antibodies; 3) tomographic recording and evaluation of patient radiation data. Under these conditions the method yields good sensitivity and specifity indexes (15/16 for primary tumors and local recurrences, 7/10 for metastasis). A strictly prospective study, however, remains mandatory in order to assess the clinical value of this method

  19. Evaluation of radioiodinated and radiocopper labeled monovalent fragments of monoclonal antibody chCE7 for targeting of neuroblastoma

    International Nuclear Information System (INIS)

    Carrel, Francois; Amstutz, Hanspeter; Novak-Hofer, Ilse; Schubiger, P. August

    1997-01-01

    Monovalent fragments of antineuroblastoma antibody mAb chCE7 were evaluated for their in vitro and in vivo tumor cell binding properties. Single chain fragments were constructed from the variable region genes cloned from hybridoma cells, expressed in E.coli and purified by metal chelate affinity chromatography. Radioiodinated CE7-scFv fragments were found to bind with high affinity (K d ∼10 -9 M) to target cells in vitro but formed aggregates at 37 deg. C, and bound to serum proteins in vitro and in vivo. Circular Dichroism spectra revealed the protein to be in a conformationally altered form and no permanent 'refolding' could be achieved. In contrast, chCE7-Fab fragments were found to bind to target tumor cells with similar affinity than the parent mAb chCE7 (K d ∼10 -10 M), showed no tendency to aggregate and were stable in serum both in vitro and in vivo. Kinetics of association and dissociation of radioiodinated scFv and Fab fragments were found to be rapid. Radioiodination with the Iodogen method led to impaired immunoreactivity which was found to further increase the off- rates of radioiodinated fragments from tumor cells. Radioiodination with the Bolton-Hunter reagent as well as labeling of chCE7-Fab fragments with 67 Cu via the macrocyclic CPTA ligand led to fully immunoreactive Fab fragments. Radioiodinated and radiocopper labeled monovalent CE7 fragments did not internalize into target tumor cells as the parent mAb and its F(ab') 2 fragment. A comparison of the biodistribution in tumor bearing nude mice of the radiocopper labeled monovalent, non internalizing Fab fragments with the internalizing divalent F(ab') 2 fragments showed in both cases high levels of radioactivity in the kidneys. Concerning tumor uptake, radioactivity from both internalizing and non internalizing fragments remained associated with tumor tissue for longer times than in case of the corresponding radioiodinated fragments. When compared with the radioiodinated forms, tumor uptake

  20. Packing motifs as predictors of the propensity of antibody fragments to crystallize

    Science.gov (United States)

    Edmundson, Allen B.; DeWitt, Christina R.; Goldsteen, Benjamin Z.; Ramsland, Paul A.

    1999-01-01

    A recurring theme in the crystallization of antibody fragments in our laboratory has been a packing pattern involving formation of intermolecular, antiparallel β-pleated sheets across two-fold axes. The most common motif is the antiparallel stacking of constant (C) domains of light (L) chain dimers or Fab molecules. Here, cross-molecule six-stranded sheets are produced by hydrogen-bonding interactions of three-residue polypeptide segments (triads), in the i, i+2 and i+4 positions of the final strands (designated 3-3) of the three-chain layers from two adjacent molecules. In the variable (V) domains the triads are supplied by the first strands (4-1) of the four-chain layers and the resulting cross-molecule sheets contain eight strands. The latter type of packing is more likely to be seen in crystals of Fv fragments (V domains only) than in those of L chain dimers or Fabs. Amongst the triads from either the V or C domains, there are on average four sets of backbone carbonyl and amide groups within hydrogen bonding distance (chain dimers, Fab and Fvs are likely to crystallize in these packing patterns.

  1. Immunoscintigraphy of human pancreatic carcinoma in nude mice with I-131-F(ab')/sub 2/-fragments of monoclonal antibodies

    International Nuclear Information System (INIS)

    Senekowitsch, R.; Maul, F.D.; Wenisch, H.J.C.; Kriegel, H.; Hor, G.

    1985-01-01

    In the present study radioiodinated F(ab')/sub 2/-fragments of CA19-9 and antibody that reacts specifically with human gastrointestinal cancer were examined for their ability to detect human pancreatic carcinoma hosted in nude mice. Tumor-bearing mice received 80μCi of I-131-F(ab')/sub 2/ with a specific activity of 1.8μCi/μg. All mice were imaged after the injection and every 24hr up to 6 days. The retained radioactivity was also registered with a whole-body counter immediately after imaging. As a control F(ab's)/sub 2/ of a nonspecific antibody were administered in parallel to another group of animals bearing the same tumor. Three animals of each group were killed at 1,2,4 and 8 days for determination of the distribution of both labeled antibody-fragments. On scintigraphic images obtained with the CA19-9-F(ab')/sub 2/ the tumors could be visualized 24hr after injection, the best dilineation however was achieved 96hr p.i.. The biodistribution data exhibited a more rapid blood clearance for the specific fragments compared to that for the unspecific ones. Tumors showed an increase in uptake up to 48hr reaching 1.7% of the injected dose per gram, declining to values of 0.08%/g at day 6 p.i.. The highest tumor-to-blood ratios were found after 96h. They were 7 for the CA19-9-fragments compared to 1.5 for the unspecific fragments. The whole body counting revealed a more rapid excretion for the fragments of the specific monoclonal antibodies than for the unspecific ones. In summary the authors were able to show that CA19-9-F(ab')/sub 2/-fragments can be used for immunodetection of human pancreatic carcinoma hosted in nude mice

  2. In vitro and in vivo tumor models for studies of distribution of radiolabelled monoclonal antibodies and fragments

    International Nuclear Information System (INIS)

    Buchegger, F.; Halpern, S.E.; Sutherland, R.M.; Schreyer, M.; Mach, J.P.; Rochester Univ., NY

    1986-01-01

    Colon carcinoma multicellular spheroids were incubated in vitro with radiolabelled MAbs. The more rapid penetration of fragments as compared to intact MAbs was clearly demonstrated. For the study of antibody localization in tumors in vivo, the model of nude mice with ligated kidneys was used. Although very artificial, this model allowed to demonstrate that, without urinary excretion, Fab fragments accumulated more rapidly into the tumor than intact MAbs and disappeared faster from the blood. This difference was less striking for F(ab') 2 fragments. In the liver a decreased accumulation of both types of fragments as compared to intact MAbs was observed. Concerning radio-immunotherapy we think that Fab fragments are not useful because of their too short half-life the circulation and in tumor and because they will probably be too toxic for the kidneys. Intact MAbs and F(ab') 2 fragments have each their advantages. Intact MAbs show highest tumor accumulation in mice without ligated kidney, however, they remain mostly on the periphery of tumor nodules, as shown by autoradiography. F(ab') 2 fragments have been found to penetrate deeper into the tumor and to accumulate less in the liver. It might be therefore an advantage to combine intact MAbs with F(ab') 2 fragments, so that in the tumor two different regions could be attacked whereas in normal tissues toxicity could be distributed to different organs such as to the liver with intact MAbs and to the kidney with F(ab') 2 fragments. (orig.) [de

  3. Cultivation of Pichia pastoris carrying the scFv anti LDL (- antibody fragment. Effect of preculture carbon source

    Directory of Open Access Journals (Sweden)

    Cesar Andres Diaz Arias

    Full Text Available Abstract Antibodies and antibody fragments are nowadays among the most important biotechnological products, and Pichia pastoris is one of the most important vectors to produce them as well as other recombinant proteins. The conditions to effectively cultivate a P. pastoris strain previously genetically modified to produce the single-chain variable fragment anti low density lipoprotein (- under the control of the alcohol oxidase promoter have been investigated in this study. In particular, it was evaluated if, and eventually how, the carbon source (glucose or glycerol used in the preculture preceding cryopreservation in 20% glycerol influences both cell and antibody fragment productions either in flasks or in bioreactor. Although in flasks the volumetric productivity of the antibody fragment secreted by cells precultured, cryopreserved and reactivated in glycerol was 42.9% higher compared with cells precultured in glucose, the use of glycerol in bioreactor led to a remarkable shortening of the lag phase, thereby increasing it by no less than thrice compared to flasks. These results are quite promising in comparison with those reported in the literature for possible future industrial applications of this cultivation, taking into account that the overall process time was reduced by around 8 h.

  4. Preparation and radiolabeling of humanized anti-HER1 monoclonal antibody nimotuzumab Fab' fragment with 68Ga and 90Y

    International Nuclear Information System (INIS)

    Alonso Martinez, L. M.; Xiques Castillo, A.; Leyva Montanna, R.; Perez-Malo Cruz, M.; Zamora Barrabi, M.; Manresa Sanchez, Y.

    2013-01-01

    Antibody-based targeted delivery of radioisotopes to malignant tissues is a promising approach in cancer diagnostics and therapy. However, intact antibody molecules are large glycoproteins (∼150 kDa) that have limited application in molecular imaging and therapy due to their relatively slow clearance from the circulation leading to a high background signal rather both cases the sensitivity can be increased with the use of enzymatically produced Fab' fragments. In this work, the ability to get labeled with 62 Ga and 90 Y of a monoclonal antibody (mAb) Fab' fragment against the transmembrane receptor tyrosine kinase HER-1 was studied for future applications in PET imaging and radioimmunotherapy of tumors. In order to obtain the Fab' fragment the mAb was cleaved with pepsin in molar excess. After separating the reaction mixture in two steps using affinity and ion-exchange chromatography, the Fab' fragment was finally obtained by reduction of the F(ab') 2 with a molar excess of 2-mercaptoethanol followed by a size exclusion purification step. The Fab' fragment was derivatized with 1,4,7,10-tetraaza cyclododecane-1,4,7,10-tetraacetic acid mono N-hydroxysuccinimide commercial ester (DOTA-NHS-ester) applying a simple procedure and the number of DOTA groups linked to Fab' were determinate. The labeling of the conjugate with 68 Ga and 90 Y from 'in-house generators yielded radiochemically pure probes that can become a suitable radioimmunoconjugated in a near future. (Author)

  5. Aptamers, antibody scFv, and antibody Fab' fragments: An overview and comparison of three of the most versatile biosensor biorecognition elements.

    Science.gov (United States)

    Crivianu-Gaita, Victor; Thompson, Michael

    2016-11-15

    The choice of biosensing elements is crucial for the development of the optimal biosensor. Three of the most versatile biosensing elements are antibody single-chain Fv fragments (scFv), antibody fragment-antigen binding (Fab') units, and aptamers. This article provides an overview of these three biorecognition elements with respects to their synthesis/engineering, various immobilization techniques, and examples of their use in biosensors. Furthermore, the final section of the review compares and contrasts their characteristics (time/cost of development, ease and variability of immobilization, affinity, stability) illustrating their advantages and disadvantages. Overall, scFv fragments are found to display the highest customizability (i.e. addition of functional groups, immobilizing peptides, etc.) due to recombinant synthesis techniques. If time and cost are an issue in the development of the biosensor, Fab' fragments should be chosen as they are relatively cheap and can be developed quickly from whole antibodies (several days). However, if there are sufficient funds and time is not a factor, aptamers should be utilized as they display the greatest affinity towards their target analytes and are extremely stable (excellent biosensor regenerability). Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Characterization of Fusobacterium necrophorum isolated from llama and alpaca.

    Science.gov (United States)

    Kumar, Amit; Anderson, David; Amachawadi, Raghavendra G; Nagaraja, Tiruvoor G; Narayanan, Sanjeev K

    2013-07-01

    Fusobacterium necrophorum, a Gram-negative, anaerobic bacterium, is an opportunistic animal and human pathogen that causes a variety of infections termed necrobacillosis. There are 2 subspecies of F. necrophorum (subsp. necrophorum and subsp. funduliforme) that differ morphologically and biochemically and in virulence. Leukotoxin, a secreted protein, is considered to be the major virulence factor. In camelids, F. necrophorum causes a variety of infections, generally involving the lips, tongue, pharynx, interdigital spaces, foot pad, larynx, mandible, or maxillary bones. The objective of the current study was to characterize the presumptive Fusobacterium isolates from a variety of necrotic infections in llama (Lama glama) and alpaca (Vicugna pacos) and determine whether the strains possess leukotoxin activities. A total of 7 isolates from alpaca and 2 isolates from llama were characterized. Based on growth characteristics in broth culture, and biochemical and polymerase chain reaction analyses, all 9 isolates belonged to subsp. necrophorum and possessed the putative hemagglutinin gene. Western blot analysis with antileukotoxin antibodies raised in rabbit showed the presence of leukotoxin protein in the culture supernatant of all isolates. Furthermore, flow cytometry of the culture supernatants demonstrated cytotoxicity to bovine and alpaca polymorphonuclear leukocytes (PMNs). The extent of cytotoxicity to either alpaca or bovine PMNs differed among camelid strains. The cytotoxicity of many of the camelid strains was higher (P llama and alpaca are similar to bovine isolates, and leukotoxin may be a major virulence factor.

  7. The Antiviral Mechanism of an Influenza A Virus Nucleoprotein-Specific Single-Domain Antibody Fragment

    Energy Technology Data Exchange (ETDEWEB)

    Hanke, Leo; Knockenhauer, Kevin E.; Brewer, R. Camille; van Diest, Eline; Schmidt, Florian I.; Schwartz, Thomas U.; Ploegh, Hidde L. (Whitehead); (MIT)

    2016-12-13

    Alpaca-derived single-domain antibody fragments (VHHs) that target the influenza A virus nucleoprotein (NP) can protect cells from infection when expressed in the cytosol. We found that one such VHH, αNP-VHH1, exhibits antiviral activity similar to that of Mx proteins by blocking nuclear import of incoming viral ribonucleoproteins (vRNPs) and viral transcription and replication in the nucleus. We determined a 3.2-Å crystal structure of αNP-VHH1 in complex with influenza A virus NP. The VHH binds to a nonconserved region on the body domain of NP, which has been associated with binding to host factors and serves as a determinant of host range. Several of the NP/VHH interface residues determine sensitivity of NP to antiviral Mx GTPases. The structure of the NP/αNP-VHH1 complex affords a plausible explanation for the inhibitory properties of the VHH and suggests a rationale for the antiviral properties of Mx proteins. Such knowledge can be leveraged for much-needed novel antiviral strategies.

    IMPORTANCEInfluenza virus strains can rapidly escape from protection afforded by seasonal vaccines or acquire resistance to available drugs. Additional ways to interfere with the virus life cycle are therefore urgently needed. The influenza virus nucleoprotein is one promising target for antiviral interventions. We have previously isolated alpaca-derived single-domain antibody fragments (VHHs) that protect cells from influenza virus infection if expressed intracellularly. We show here that one such VHH exhibits antiviral activities similar to those of proteins of the cellular antiviral defense (Mx proteins). We determined the three-dimensional structure of this VHH in complex with the influenza virus nucleoprotein and identified the interaction site, which overlaps regions that determine sensitivity of the virus to Mx proteins. Our data define a new vulnerability of influenza virus, help us to better understand the cellular antiviral mechanisms, and

  8. Fab fragments of ovine antibody to colchicine enhance its clearance in the rat.

    Science.gov (United States)

    Peake, Philip W; Pianta, Timothy J; Succar, Lena; Fernando, Mangalee; Buckley, Nicholas A; Endre, Zoltan H

    2015-06-01

    Colchicine is an anti-inflammatory alkaloid used for the treatment of acute gout, but has a narrow therapeutic index. Colchicine overdoses are relatively rare, but have high mortality requiring rapid treatment. To evaluate the ability of a newly available ovine fragment antigen-binding (Fab) antibody to colchicine (ColchiFab(™)) to protect rats against renal and other injury 24 h after colchicine ingestion. Rats were gavaged with colchicine (5 mg/kg), then 2 h later injected intraperitoneally with 5 ml of sterile saline, or Fab anti-colchicine, a newly available ovine antibody to colchicine. Samples of blood were taken at 1, 2, 5 and 24 h after gavage, and urine was collected from 5 to 24 h after gavage. Concentrations of colchicine in tissue, blood and urine were measured by liquid chromatography/mass spectrometry, concentrations of Fab anti-colchicine, urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 or KIM-1 by enzyme-linked immunosorbent assay or ELISA, while concentrations of creatine kinase and creatinine (Cr) were measured enzymatically. Colchicine equilibrated rapidly throughout the body and increased serum creatine kinase. Fab anti-colchicine also rapidly redistributed to the blood and remained at high concentrations over 24 h. Fab anti-colchicine caused a rapid 7.1-fold increase in serum colchicine level, followed by excretion of both colchicine and Fab anti-colchicine through the urine. This was associated with the accumulation of colchicine in the kidney, a reversal of colchicine-induced diarrhoea, and increasing urinary NGAL level; from 168 ± 48 to 477 ± 255 ng/mmol Cr [mean ± standard deviation or SD]. Fab anti-colchicine greatly increased the clearance of colchicine, although increasing NGAL level suggested the presence of mild kidney damage. These data suggest clinical utility for Fab anti-colchicine in the treatment of colchicine overdose.

  9. Isolation and characterisation of Ebolavirus-specific recombinant antibody fragments from murine and shark immune libraries.

    Science.gov (United States)

    Goodchild, Sarah A; Dooley, Helen; Schoepp, Randal J; Flajnik, Martin; Lonsdale, Stephen G

    2011-09-01

    Members of the genus Ebolavirus cause fulminating outbreaks of disease in human and non-human primate populations with a mortality rate up to 90%. To facilitate rapid detection of these pathogens in clinical and environmental samples, robust reagents capable of providing sensitive and specific detection are required. In this work recombinant antibody libraries were generated from murine (single chain variable domain fragment; scFv) and nurse shark, Ginglymostoma cirratum (IgNAR V) hosts immunised with Zaire ebolavirus. This provides the first recorded IgNAR V response against a particulate antigen in the nurse shark. Both murine scFv and shark IgNAR V libraries were panned by phage display technology to identify useful antibodies for the generation of immunological detection reagents. Two murine scFv were shown to have specificity to the Zaire ebolavirus viral matrix protein VP40. Two isolated IgNAR V were shown to bind to the viral nucleoprotein (NP) and to capture viable Zaire ebolavirus with a high degree of sensitivity. Assays developed with IgNAR V cross-reacted to Reston ebolavirus, Sudan ebolavirus and Bundibugyo ebolavirus. Despite this broad reactivity, neither of IgNAR V showed reactivity to Côte d'Ivoire ebolavirus. IgNAR V was substantially more resistant to irreversible thermal denaturation than murine scFv and monoclonal IgG in a comparative test. The demonstrable robustness of the IgNAR V domains may offer enhanced utility as immunological detection reagents in fieldable biosensor applications for use in tropical or subtropical countries where outbreaks of Ebolavirus haemorrhagic fever occur. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  10. Secretory signal peptide modification for optimized antibody-fragment expression-secretion in Leishmania tarentolae

    Directory of Open Access Journals (Sweden)

    Klatt Stephan

    2012-07-01

    Full Text Available Abstract Background Secretory signal peptides (SPs are well-known sequence motifs targeting proteins for translocation across the endoplasmic reticulum membrane. After passing through the secretory pathway, most proteins are secreted to the environment. Here, we describe the modification of an expression vector containing the SP from secreted acid phosphatase 1 (SAP1 of Leishmania mexicana for optimized protein expression-secretion in the eukaryotic parasite Leishmania tarentolae with regard to recombinant antibody fragments. For experimental design the online tool SignalP was used, which predicts the presence and location of SPs and their cleavage sites in polypeptides. To evaluate the signal peptide cleavage site as well as changes of expression, SPs were N-terminally linked to single-chain Fragment variables (scFv’s. The ability of L. tarentolae to express complex eukaryotic proteins with highly diverse post-translational modifications and its easy bacteria-like handling, makes the parasite a promising expression system for secretory proteins. Results We generated four vectors with different SP-sequence modifications based on in-silico analyses with SignalP in respect to cleavage probability and location, named pLTEX-2 to pLTEX-5. To evaluate their functionality, we cloned four individual scFv-fragments into the vectors and transfected all 16 constructs into L. tarentolae. Independently from the expressed scFv, pLTEX-5 derived constructs showed the highest expression rate, followed by pLTEX-4 and pLTEX-2, whereas only low amounts of protein could be obtained from pLTEX-3 clones, indicating dysfunction of the SP. Next, we analysed the SP cleavage sites by Edman degradation. For pLTEX-2, -4, and -5 derived scFv’s, the results corresponded to in-silico predictions, whereas pLTEX-3 derived scFv’s contained one additional amino-acid (AA. Conclusions The obtained results demonstrate the importance of SP-sequence optimization for efficient

  11. 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.

  12. Ultra scaledown to predict filtering centrifugation of secreted antibody fragments from fungal broth.

    Science.gov (United States)

    Boulding, N; Yim, S S S; Keshavarz-Moore, E; Ayazi Shamlou, P; Berry, M

    2002-08-20

    Extracellularly expressed anti-hen egg lysozyme single-chain antibody fragments (scFv) produced by Aspergillus awamori were recovered using filtering centrifugation. Two filtering centrifuges with 0.5- and 30-L capacities were used to represent laboratory- and pilot-scale equipment, respectively. Critical regime analysis using the computational fluid dynamics (CFD) technique provided information about the local energy dissipation rates in both units. Experimental data indicated loss of scFv activity for energy dissipation rates above about 2.0 x 10(4) W kg(-1). This loss of activity increased in the presence of gas-liquid interfaces during filtering centrifugation. An ultra scaledown filtering centrifuge with a maximum working volume of 35 mL was designed to mimic the operating conditions identified by the critical regime analysis for the laboratory- and pilot-plant-scale units. The recovered scFv activity levels and the separation performance of the three units were comparable when operated at equal maximum energy dissipation rates. Copyright 2002 Wiley Periodicals, Inc.

  13. A recombinant dromedary antibody fragment (VHH or nanobody) directed against human Duffy antigen receptor for chemokines.

    Science.gov (United States)

    Smolarek, Dorota; Hattab, Claude; Hassanzadeh-Ghassabeh, Gholamreza; Cochet, Sylvie; Gutiérrez, Carlos; de Brevern, Alexandre G; Udomsangpetch, Rachanee; Picot, Julien; Grodecka, Magdalena; Wasniowska, Kazimiera; Muyldermans, Serge; Colin, Yves; Le Van Kim, Caroline; Czerwinski, Marcin; Bertrand, Olivier

    2010-10-01

    Fy blood group antigens are carried by the Duffy antigen receptor for chemokines (DARC), a red cells receptor for Plasmodium vivax broadly implicated in human health and diseases. Recombinant VHHs, or nanobodies, the smallest intact antigen binding fragment derivative from the heavy chain-only antibodies present in camelids, were prepared from a dromedary immunized against DARC N-terminal extracellular domain and selected for DARC binding. A described VHH, CA52, does recognize native DARC on cells. It inhibits P. vivax invasion of erythrocytes and displaces interleukin-8 bound to DARC. The targeted epitope overlaps the well-defined DARC Fy6 epitope. K (D) of CA52-DARC equilibrium is sub-nanomolar, hence ideal to develop diagnostic or therapeutic compounds. Immunocapture by immobilized CA52 yielded highly purified DARC from engineered K562 cells. This first report on a VHH with specificity for a red blood cell protein exemplifies VHHs' potentialities to target, to purify, and to modulate the function of cellular markers.

  14. Characterization of crystals of an antibody-recognition fragment of the cancer differentiation antigen mesothelin in complex with the therapeutic antibody MORAb-009

    International Nuclear Information System (INIS)

    Ma, Jichun; Tang, Wai Kwan; Esser, Lothar; Pastan, Ira; Xia, Di

    2012-01-01

    The therapeutic antibody MORAb-009 disrupts the interaction of mesothelin and the ovarian cancer antigen CA-125. Crystals have been grown of the Fab fragment derived from MORAb-009 and of its complex with an N-terminal fragment of mesothelin. The mesothelin-specific monoclonal antibody MORAb-009 is capable of blocking the binding of mesothelin to CA-125 and displays promising anticancer potential. It is currently undergoing clinical trials. In order to understand the basis of the interaction between MORAb-009 and mesothelin at atomic resolution, both the Fab fragment of MORAb-009 and the complex between the Fab and an N-terminal fragment of mesothelin (residues 7–64) were crystallized. The crystals of the Fab diffracted X-rays to 1.75 Å resolution and had the symmetry of space group P4 1 2 1 2, with unit-cell parameters a = b = 140.6, c = 282.0 Å. The crystals of the mesothelin–Fab complex diffracted to 2.6 Å resolution and belonged to the hexagonal space group P6 4 , with unit-cell parameters a = b = 146.2, c = 80.9 Å. Structural analyses of these molecules are in progress

  15. 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.

  16. Reproduction in llamas and alpacas: a review.

    Science.gov (United States)

    Smith, C L; Peter, A T; Pugh, D G

    1994-02-02

    In this review we attempt to compile and summarize the diverse and often contradictory material presented on the reproduction of llamas and alpacas (hereafter referred to as lamoids). Lamoids have recently gained international popularity, and theriogenologists are often asked to intervene in clinical management of reproductive problems of these animals. We therefore present a discussion of the reproductive anatomy, physiology, and behavior of llamas as well as the follicular dynamics as observed with ultrasonography. The nonsurgical embryo transfer procedure and the nutrient requirements of llamas are also discussed.

  17. Unilateral nephrectomy in a juvenile llama

    International Nuclear Information System (INIS)

    Van Hoogmoed, L.; Snyder, J.R.; Roberts, G.; Harmon, F.A.

    1997-01-01

    The purpose of this study was to describe the clinical presentation, diagnostic evaluation, and surgical management of a llama with an ectopic ureter. Nine-month-old female llama. The diagnostic evaluation included the use of computed tomography and an excretory ureterogram to confirm and identify the location of the ectopic ureter. Surgical management involved a unilateral nephrectomy. Computed tomography is a valuable asset to diagnose the presence and terminal location of an ectopic ureter in llamas, and nephrectomy appears to be a viable procedure to resolve the subsequent urinary incontinence

  18. Phage display selection of fully human antibody fragments to inhibit growth-promoting effects of glycine-extended gastrin 17 on human colorectal cancer cells.

    Science.gov (United States)

    Khajeh, Shirin; Tohidkia, Mohammad Reza; Aghanejad, Ayuob; Mehdipour, Tayebeh; Fathi, Farzaneh; Omidi, Yadollah

    2018-06-09

    Glycine-extended gastrin 17 (G17-Gly), a dominant processing intermediate of gastrin gene, has been implicated in the development or maintenance of colorectal cancers (CRCs). Hence, neutralizing G17-Gly activity by antibody entities can provide a potential therapeutic strategy in the patients with CRCs. To this end, we isolated fully human antibody fragments from a phage antibody library through biopanning against different epitopes of G17-Gly in order to obtain the highest possible antibody diversity. ELISA screening and sequence analysis identified 2 scFvs and 4 V L antibody fragments. Kinetic analysis of the antibody fragments by SPR revealed K D values to be in the nanomolar range (87.9-334 nM). The selected anti-G17-Gly antibody fragments were analyzed for growth inhibition and apoptotic assays in a CRC cell line, HCT-116, which is well-characterized for expressing gastrin intermediate species but not amidated gastrin. The antibody fragments exhibited significant inhibition of HCT-116 cells proliferation ranging from 36.5 to 73% of controls. Further, Annexin V/PI staining indicated that apoptosis rates of scFv H8 and V L G8 treated cells were 45.8 and 63%, respectively. Based on these results, we for the first time, demonstrated the isolation of anti-G17-Gly human scFv and V L antibodies with potential therapeutic applications in G17-Gly-responsive tumors.

  19. 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.

  20. Use and limitations of radiolabelled anti-CEA antibodies and their fragments for photoscanning detection of human colorectal carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Mach, J P; Forni, M; Ritschard, J; Buchegger, F; Carrel, S; Widgren, S; Donath, A; Alberto, P [Lausanne Univ. (Switzerland)

    1980-08-01

    Fifty-three patients with histologically proven carcinoma were injected with highly purified (/sup 131/I)-labelled goat antibodies or fragments of antibodies against carcinoembryonic antigen (CEA). Each patient was tested by external photoscanning 4, 24, 36, 48h after injection. In 22 patients (16 of 38 injected with intact antibodies, 5 of 13 with F(ab')/sub 2/ fragments and 1 of 2 with Fab' fragments), an increased concentration of /sup 131/I radioactivity corresponding to the previously known tumor location was detected by photoscanning 36-48 h after injection. Blood pool and secreted radioactivity was determined in all patients by injecting 15 min after scanning, (sup(99m)Tc)-labeled normal serum albumin and free sup(99m)TcO/sub 4//sup -/. The computerized subtraction of sup(99m)Tc from /sup 131/I radioactivity enhanced the definition of tumor localization in the 22 positive patients. However, in spite of the computerized subtraction, interpretation of the scans remained doubtful for 12 patients and was entirely negative for 19 additional patients.

  1. Production and purification of polyclonal antibody against F(ab')2 fragment of human immunoglobulin G

    OpenAIRE

    Nasiri, Hadi; Valedkarimi, Zahra; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Kazemi, Tohid; Esparvarinha, Mojghan; Majidi, Jafar

    2017-01-01

    Antibodies are essential tools of biomedical and biochemical researches. Polyclonal antibodies are produced against different epitopes of antigens. Purified F(ab')2 can be used for animal’s immunization to produce polyclonal antibodies. Human immunoglobulin G (IgG) was purified by ion exchange chromatography method. In all stages verification method of the purified antibodies was sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Purified IgG was digested by pepsin enzyme a...

  2. Serum and urine analysis of the aminoterminal procollagen peptide type III by radioimmunoassay with antibody Fab fragments.

    Science.gov (United States)

    Rohde, H; Langer, I; Krieg, T; Timpl, R

    1983-09-01

    A radioimmunoassay based on antibody Fab fragments was developed for the aminoterminal peptide Col 1-3 of bovine type III procollagen. This assay does not distinguish the intact aminopropeptide Col 1-3 from its globular fragment Col 1. Parallel inhibition profiles were observed with human serum and urine allowing the simultaneous quantitative determination of intact and fragmented antigens in these samples. Most of the material has a size similar to that of fragment Col 1 indicating that the aminopropeptide is degraded under physiologic conditions. The concentration of aminopeptide in normal sera was in the range 15-63 ng/ml. Daily excretion was found to be in the range 30-110 micrograms. More than 50% of patients with alcoholic hepatitis and liver cirrhosis showed elevated serum levels of aminopropeptide by the Fab assay. Elevated concentrations were detected more frequently with an antibody radioimmunoassay which measures mainly the intact form of the aminopropeptide. It is suggested that analysis of patients material by both assays could improve their diagnostic application.

  3. An Ehrlichia strain from a llama (Lama glama) and Llama-associated ticks (Ixodes pacificus).

    Science.gov (United States)

    Barlough, J E; Madigan, J E; Turoff, D R; Clover, J R; Shelly, S M; Dumler, J S

    1997-01-01

    An ehrlichia was identified in the blood of a diseased llama (lama glama). Sequencing of its 16S rRNA gene showed the ehrlichia to be closely related to members of the Ehrlichia phagocytophila genogroup. The agent was also found in a pool of ticks (Ixodes pacificus) collected at the llama site. PMID:9157118

  4. Radiolabeled monoclonal antibody 15 and its fragments for localization and imaging of xenografts of human lung cancer

    International Nuclear Information System (INIS)

    Endo, K.; Kamma, H.; Ogata, T.

    1988-01-01

    Monoclonal antibody (MAb) 15 and its F(ab')2 and Fab fragments were radioiodinated, and their biodistribution and imaging were compared in BALB/c nude mice bearing a xenograft of a human lung cancer (TKB-2). Association constants for 125I-labeled MAb 15 IgG, F(ab')2, and Fab were 1.9 X 10(9), 1.8 X 10(9), and 3.7 X 10(8) M-1, respectively. Immunoreactive fractions ranged from 0.59 to 0.50. Cultured TKB-2 cells expressed 1.1 X 10(4) binding sites/cell for MAb 15 IgG in vitro. The binding of a control antibody and the binding of its fragments to TKB-2 cells were less than 3% of the input doses. The mice with the TKB-2 tumors were given simultaneous injections of 10 microCi of 131I-labeled MAb 15 or its fragments and 10 microCi of 125I-labeled control IgG or its fragments. With MAb 15 IgG, the percentage of the injected dose bound per gram of tissue (ID/g) of the tumor was 3.68% at day 7, when the localization index (LI) was 4.38. At day 2 after MAb 15 F(ab')2 injection, 1.12% of the ID/g was localized in the tumor and the LI was 3.04. After MAb 15 Fab injection, the percentage of the ID/g of the tumor was 0.31% and the LI was 2.58 at day 1. MAb 15 IgG, F(ab')2, and Fab cleared from the blood early, with a half-life of 33, 16, and 9 hours, respectively. The distributions of MAb 15 and its fragments in the normal organs did not differ from those of the control. Radioimaging with 100 microCi of 131I-labeled MAb 15 and its fragments showed that 42%, 44%, and 32% of the total-body count were localized in the tumor with IgG at day 7, F(ab')2 at day 2, or Fab at day 1, respectively. Because the radioactivity remaining in the tumor with Fab was low, the image was insufficient. Throughout the period, less than 10% of the control IgG and its fragments remained in the tumor. Microautoradiography confirmed the binding of MAb 15 and its fragments to the tumor cells

  5. F(ab'2 antibody fragments against Trypanosoma cruzi calreticulin inhibit its interaction with the first component of human complement

    Directory of Open Access Journals (Sweden)

    LORENA AGUILAR

    2005-01-01

    Full Text Available Trypanosoma cruzi calreticulin (TcCRT, described in our laboratory, retains several important functional features from its vertebrate homologues. We have shown that recombinant TcCRT inhibits the human complement system when it binds to the collagenous portion of C1q. The generation of classical pathway convertases and membrane attack complexes is thus strongly inhibited. In most T. cruzi-infected individuals, TcCRT is immunogenic and mediates the generation of specific antibodies. By reverting the C1q / TcCRT interaction, a parasite immune evasion strategy, these antibodies contribute to the host / parasite equilibrium. In an in vitro correlate of this situation, we show that the C1q / TcCRT interaction is inhibited by F(ab'2 polyclonal anti-TcCRT IgG fragments. It is therefore feasible that in infected humans anti-TcCRT antibodies participate in reverting an important parasite strategy aimed at inhibiting the classical complement pathway. Thus, membrane-bound TcCRT interacts with the collagenous portion C1q, and this C1q is recognized by the CD91-bound host cell CRT, thus facilitating parasite internalization. Based on our in vitro results, it could be proposed that the in vivo interaction between TcCRT and vertebrate C1q could be inhibited by F(ab'2 fragments anti-rTcCRT or against its S functional domain, thus interfering with the internalization process

  6. Bivalent fragment of the ior-CEA1 antibody. A challenge to the positive CEA tumors radioimmunotherapy

    International Nuclear Information System (INIS)

    Ravelo, Rolando; Sanchez, Iradia; Pimentel, Gilmara; Oliva, Juan; Perez, Lincidio; Ayala, Marta; Bell, Hansell; Gavilondo, Jorge

    2006-01-01

    The directed radiotherapy of the solid tumors with fragments recombinants of radiolabelled antibodies is a topic of current investigation, so much at preclinical level as clinical. This work describes the preclinical characterization of a new fragment type diabody of the AcMo ior CEA1 that has been labelled with 131 I for their use in the diagnosis and the therapy of CEA positive tumors. The radiolabelling methodology used allows the incorporation of more than 90% of the radio iodine to the molecule without committing the capacity of recognition of its antigen significantly. The combination of the favourable properties pharmacy kinetic and high selective accumulation in the tumor, they make of the diabody anti CEA an appropriate candidate for the radioimmunodiagnosis and the radioimmunotherapy of tumors that expresses CEA (Author)

  7. Monoclonal Antibody Fragments for Targeting Therapeutics to Growth Plate Cartilage | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    Researchers at The Eunice Kennedy Shriver National Institute on Child Health and Human Development (NICHD) have discovered monoclonal antibodies that bind to matrilin-3, a protein specifically expressed in cartilage tissue, that could be used for treating or inhibiting growth plate disorders, such as a skeletal dysplasia or short stature. The monoclonal antibodies can also be used to target therapeutic agents, such as anti-arthritis agents, to cartilage tissue. NICHD seeks statements of capability or interest from parties interested in collaborative research to co-develop, evaluate, or commercialize treatment of skeletal disorders using targeting antibodies.

  8. Codon-Precise, Synthetic, Antibody Fragment Libraries Built Using Automated Hexamer Codon Additions and Validated through Next Generation Sequencing

    Directory of Open Access Journals (Sweden)

    Laura Frigotto

    2015-05-01

    Full Text Available We have previously described ProxiMAX, a technology that enables the fabrication of precise, combinatorial gene libraries via codon-by-codon saturation mutagenesis. ProxiMAX was originally performed using manual, enzymatic transfer of codons via blunt-end ligation. Here we present Colibra™: an automated, proprietary version of ProxiMAX used specifically for antibody library generation, in which double-codon hexamers are transferred during the saturation cycling process. The reduction in process complexity, resulting library quality and an unprecedented saturation of up to 24 contiguous codons are described. Utility of the method is demonstrated via fabrication of complementarity determining regions (CDR in antibody fragment libraries and next generation sequencing (NGS analysis of their quality and diversity.

  9. Technetium-99 labelling of DD-3B6/22 antifibrin monoclonal antibody fragmented Fab' for thrombus imaging

    International Nuclear Information System (INIS)

    Lee, F-T.; Boniface, G.R.; Lambrecht, R.M.; Rylatt, D.B.; Bundesen, P.G.

    1993-01-01

    The antifibrin DD-3B6/22 monoclonal antibody Fab' fragment, a murine immunoglobulin, IgG3, has been labelled with technetium-99m ( 99mTc ) via a transchelation reaction, to specific activity in excess of 30 mCi/mg protein. The radiolabelling of Fab' was dependent on time, temperature, pH, antibody concentrations and nature intermediary transchelation complex used. The resultant radioconjugate was stable in vitro and in vivo. Blood clearance of 99m Tc-Fab' in rat followed two compartment kinetics with the half time of the fast phase being 0.5 h. The main route of excretion was via the kidneys with little uptake indicated by other tissues. The results suggest that the inherent specificity of the antibody, small molecular size, rapid plasma clearance, high specific radioactivity, together with the physical properties of the 99m Tc label, combine to make this labelled monoclonal antibody (MoAb), potentially suitable as a radiopharmaceutical for the scintigraphic detection of thrombi in humans. 17 refs., 3 tabs., 5 figs

  10. Radioimmunoimaging of experimental thrombi in dogs using technetium-99m-labeled monoclonal antibody fragments reactive with human platelets

    International Nuclear Information System (INIS)

    Som, P.; Oster, Z.H.; Zamora, P.O.; Yamamoto, K.; Sacker, D.F.; Brill, A.B.; Newell, K.D.; Rhodes, B.A.

    1986-01-01

    Monoclonal antibody 50H.19, which reacts with human platelets, was converted to fragments, pretinned, and made into kits for subsequent radiolabeling with /sup 99m/Tc. The antibody, which cross-reacts with dog platelets, was used to evaluate in vitro binding to blood clots and in vivo in experimental thrombi in dogs. After radiolabeling, 97.4 +/- 6.4% of the /sup 99m/Tc was antibody-associated. The preparations retained immunoreactivity, as determined by: binding studies using whole blood and determining the ratio of cell-to-plasma radioactivity (ratios of 57.6-61.2) and binding of the antibody to clots (clot/serum ratios were 57.2-74.6%). Approximately 50% of the radioactivity was cleared from the blood in 3-6 min and 18-24% was excreted in urine within 3 hr. Experimental thrombi in dogs could be visualized consistently within 2-3 hr postinjection in peripheral veins and arteries, pulmonary arteries, and the right ventricle. In addition, damage to blood vessel intima without visible thrombi could also be detected. This method has the following advantages: short and simple pre-imaging preparation, and rapid visualization of thrombi with no need for blood-pool subtraction or delayed imaging

  11. Radioimmunolocalization and selective delivery of radiation in a rat model system: comparison of intact and fragmented antibody

    International Nuclear Information System (INIS)

    Walker, K.Z.; Seymour-Munn, K.; Axiak, S.M.; Raison, R.L.; Basten, A.; Towson, J.E.; Bautovitch, G.J.; Morris, J.

    1988-01-01

    Monoclonal antibody (MoAb) fragments are known to have advantages over intact immunoglobulins for radioimmunoscintigraphy. It is less clear whether they are as effective in the delivery of radioimmunotherapy. The imaging and dosimetric properties of an intact MoAb, K-1-21, reactive against human kappa light chains (LC) were compared with that of its F(ab') 2 and Fab fragments using a normal rat model system. Two days after injection of 131 I-K-1-21 into rats bearing antigen-sepharose implants, gamma camera images showed specific localization of the MoAb to the target (kappa LC) but not to the control (lambda LC) implant. Better images were obtained with K-1-21 F(ab') 2 than with Fab or intact antibody. Mean kappa implant: blood ratios were 8.6 ± 3.9 for Fab, 7.9 ± 1.8 for F(ab') 2 and 2.0 ± 0.3 for intact K-1-21. The improvement associated with the use of 131 I-K-1-21 fragments was, however, achieved at the expense of lower absolute values of activity at the target site. Thus the absorbed dose delivered to the implant by the intact K-1-21 was double that delivered with F(ab') 2 and six times that delivered with Fab. As intact K-1-21 also delivered a greater radiation dose to normal tissues, F(ab') 2 fragments may have the greatest overall advantages for therapy with radionuclide MoAb conjugates. (author)

  12. A novel method for in Situ detection of hydrolyzable casein fragments in a cheese matrix by antibody phage display technique and CLSM

    DEFF Research Database (Denmark)

    Duan, Zhi; Brüggemann, Dagmar Adeline; Siegumfeldt, Henrik

    2009-01-01

    three small synthetic peptides of the alpha(s1)-casein sequence. These peptides traverse enzymatic cleavage sites of casein during cheese ripening. The specificity of the generated anti-peptide antibodies was determined by ELISA and Western blot. Finally, an immunofluorescent labeling protocol......A novel method to monitor in situ hydrolyzable casein fragments during cheese ripening by using immunofluorescent labeling and confocal laser scanning microscopy (CLSM) was developed. Monoclonal single chain variable fragments of antibody (scFvs) were generated by antibody phage display toward...

  13. Studies of nontarget-mediated distribution of human full-length IgG1 antibody and its FAb fragment in cardiovascular and metabolic-related tissues.

    Science.gov (United States)

    Davidsson, Pia; Söderling, Ann-Sofi; Svensson, Lena; Ahnmark, Andrea; Flodin, Christine; Wanag, Ewa; Screpanti-Sundqvist, Valentina; Gennemark, Peter

    2015-05-01

    Tissue distribution and pharmacokinetics (PK) of full-length nontargeted antibody and its antigen-binding fragment (FAb) were evaluated for a range of tissues primarily of interest for cardiovascular and metabolic diseases. Mice were intravenously injected with a dose of 10 mg/kg of either human IgG1or its FAb fragment; perfused tissues were collected at a range of time points over 3 weeks for the human IgG1 antibody and 1 week for the human FAb antibody. Tissues were homogenized and antibody concentrations were measured by specific immunoassays on the Gyros system. Exposure in terms of maximum concentration (Cmax ) and area under the curve was assessed for all nine tissues. Tissue exposure of full-length antibody relative to plasma exposure was found to be between 1% and 10%, except for brain (0.2%). Relative concentrations of FAb antibody were the same, except for kidney tissue, where the antibody concentration was found to be ten times higher than in plasma. However, the absolute tissue uptake of full-length IgG was significantly higher than the absolute tissue uptake of the FAb antibody. This study provides a reference PK state for full-length whole and FAb antibodies in tissues related to cardiovascular and metabolic diseases that do not include antigen or antibody binding. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. Radioiodinated iodobenzoyl conjugates of a monoclonal antibody Fab fragment. In vivo comparisons with chloramine-T-labeled Fab

    International Nuclear Information System (INIS)

    Wilbur, D.S.; Hadley, S.W.; Grant, L.M.; Hylarides, M.D.

    1991-01-01

    A comparative investigation of the biodistributions of radioiodinated p- and m-iodobenzoyl conjugates of a monoclonal antibody Fab fragment, NR-LU-10 Fab, and the same antibody Fab fragment radioiodinated by the chloramine-T (ChT) method has been carried out in mice. Coinjected, dual-isotope studies in athymic mice with tumor xenografts have demonstrated that there are only minor differences in the in vivo distributions of the iodobenzoyl-labeled Fabs, except in the excretory organs, kidneys, and intestines, where major differences were observed. Similarly, coinjection of either the p-iodobenzoyl or m-iodobenzoyl conjugate of NR-LU-10 Fab with the Fab radioiodinated with ChT/radioiodide into BALB/c mice provided additional data that indicated that the two iodobenzoyl conjugates distributed similar in a number of selected tissues. The tissue-distribution differences of the regioisomeric iodobenzoyl conjugates in relation to the ChT-radioiodinated Fab were large for the stomach and neck, consistent with previous studies. The most notable difference between the two iodobenzoyl conjugates was the kidney activity, where the m-iodobenzoyl conjugate was similar to the directly labeled Fab, but the p-iodobenzoyl-conjugated Fab was higher by nearly a factor of 2

  15. Potent neutralization of VEGF biological activities with a fully human antibody Fab fragment directed against VEGF receptor 2

    International Nuclear Information System (INIS)

    Miao, H.-Q.; Hu, Kun; Jimenez, Xenia; Navarro, Elizabeth; Zhang, Haifan; Lu Dan; Ludwig, Dale L.; Balderes, Paul; Zhu Zhenping

    2006-01-01

    Compelling evidence suggest that vascular endothelial growth factor (VEGF) and its receptors, especially receptor 2 (VEGFR2, or kinase insert domain-containing receptor, KDR), play a critical role in angiogenesis under both physiological and pathological conditions, including cancer and angiogenic retinopathies such as age-related macular degeneration (AMD). To this end, inhibition of angiogenesis with antagonists to either VEGF or KDR has yielded significant therapeutic efficacy both in preclinical studies in animal models and in clinical trials in patients with cancer and AMD. We previously reported the identification of a high affinity, fully human anti-KDR antibody fragment, 1121B Fab, through a highly stringent affinity maturation process with a Fab originally isolated from a naive human antibody phage display library. In this study, we demonstrate that 1121B Fab is able to strongly block KDR/VEGF interaction, resulting in potent inhibition of an array of biological activities of VEGF, including activation of the receptor and its signaling pathway, intracellular calcium mobilization, and migration and proliferation of endothelial cells. Taken together, our data lend strong support to the further development of 1121B Fab fragment as an anti-angiogenesis agent in both cancer and angiogenic retinopathies

  16. Site-specific chemical modification of antibody fragments using traceless cleavable linkers.

    Science.gov (United States)

    Bernardes, Gonçalo J L; Steiner, Martina; Hartmann, Isabelle; Neri, Dario; Casi, Giulio

    2013-11-01

    Antibody-drug conjugates (ADCs) are promising agents for the selective delivery of cytotoxic drugs to specific cells (for example, tumors). In this protocol, we describe two strategies for the precise modification at engineered C- or N-terminal cysteines of antibodies in IgG, diabody and small immunoprotein (SIP) formats that yield homogenous ADCs. In this protocol, cemadotin derivatives are used as model drugs, as these agents have a potent cytotoxic activity and are easy to synthesize. However, other drugs with similar functional groups could be considered. In the first approach, a cemadotin derivative containing a sulfhydryl group results in a mixed disulfide linkage. In the second approach, a cemadotin derivative containing an aldehyde group is joined via a thiazolidine linkage. The procedures outlined are robust, enabling the preparation of ADCs with a defined number of drugs per antibody in a time frame between 7 and 24 h.

  17. Selection of monoclonal anti-CEA antibody fragments for tumor detection by immunoscintigraphy

    International Nuclear Information System (INIS)

    Mach, J.P.; Buchegger, F.

    1986-01-01

    It is described how individual MAb directed against carcinoembryotic antigen (CEA) is selected which does not crossreact with granulocytes and gives the best tumor localization in the model of nude mice grafted with human colon carcinoma. Using this model, the superiority of F(ab')/sub 2/ and particularly Fab fragments from high affinity MAb for the localization of relatively small tumor nodules is demonstrated. These MAb fragments are also successfully used in an ongoing clinical trial for the detection of primary and metastatic colorectal carcinomas

  18. Feasibility study of the Fab fragment of a monoclonal antibody against tissue factor as a diagnostic tool.

    Science.gov (United States)

    Tsumura, Ryo; Sato, Ryuta; Furuya, Fumiaki; Koga, Yoshikatsu; Yamamoto, Yoshiyuki; Fujiwara, Yuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

    2015-12-01

    Tissue factor (TF) is expressed strongly in various types of cancer, especially cancers that are often refractory to treatment, such as pancreatic cancer. In this study, we compared the differences in the biophysical and pharmacological properties of whole IgG and the Fab fragment of anti-human TF monoclonal antibody (1849 antibodies), in order to determine their suitability for application in the diagnosis and treatment of cancers. In the biophysical examination, we investigated the characteristics of 1849-whole IgG and 1849-Fab by SPR sensing and confocal fluorescence microscopy analysis using recombinant human TF antigen and TF-overexpressing human pancreatic cancer cell line, BxPC3, respectively. After conjugation with Alexa-Flour-647, in vivo imaging was conducted in mice bearing BxPC3 xenograft tumors. Furthermore, the distribution of the conjugates in tumors and major organs was evaluated by ex vivo study. The in vitro experiments showed that 1849 antibodies had high affinity against TF antigen. In addition, 1849-Fab showed a faster dissociation rate from the antigen than 1849-whole IgG. In mice, 1849-Fab-Alexa-Flour-647 showed rapid renal clearance and faster tumor accumulation, achieving a high contrast signal over nearby normal tissues in the early phase and enhanced tumor penetration after administration. On the other hand, 1849-whole IgG-Alexa-Flour-647 showed slow clearance from the blood and sustained high tumor accumulation. These results suggest that 1849-Fab may be a useful tool for pancreatic cancer diagnosis.

  19. 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.

  20. 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.

  1. Hepatic encephalopathy associated with hepatic lipidosis in llamas (Lama glama).

    Science.gov (United States)

    Pillitteri, C A; Craig, L E

    2013-01-01

    Hepatic encephalopathy has been listed as a differential for llamas displaying neurologic signs, but it has not been histopathologically described. This report details the neurologic histopathologic findings associated with 3 cases of hepatic lipidosis with concurrent neurologic signs and compares them to 3 cases of hepatic lipidosis in the absence of neurologic signs and 3 cases without hepatic lipidosis. Brain from all 3 llamas displaying neurologic signs contained Alzheimer type II cells, which were not detected in either subset of llamas without neurologic signs. Astrocytic immunohistochemical staining intensity for glial fibrillary acid protein was decreased in llamas with neurologic signs as compared to 2 of 3 llamas with hepatic lipidosis and without neurologic signs and to 2 of 3 llamas without hepatic lipidosis. Immunohistochemical staining for S100 did not vary between groups. These findings suggest that hepatic encephalopathy may be associated with hepatic lipidosis in llamas.

  2. 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.

  3. Reproductive endocrinology of llamas and alpacas.

    Science.gov (United States)

    Bravo, P W

    1994-07-01

    The physiology of reproduction with emphasis in endocrinology of llamas and alpacas is addressed. Basic concepts of ovarian follicular dynamics, endocrine events associated with induction of ovulation, corpus luteum formation, pregnancy, parturition, postpartum interval, puberty, and sexual behavior on the female are reviewed. Pathologic conditions of the reproductive process are also reviewed.

  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 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

  6. 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.

  7. Therapeutic Activity of an Engineered Synthetic Killer Antiidiotypic Antibody Fragment against Experimental Mucosal and Systemic Candidiasis

    OpenAIRE

    Polonelli, Luciano; Magliani, Walter; Conti, Stefania; Bracci, Luisa; Lozzi, Luisa; Neri, Paolo; Adriani, Daniela; De Bernardis, Flavia; Cassone, Antonio

    2003-01-01

    Peptides derived from the sequence of a single-chain, recombinant, antiidiotypic antibody (IdAb; KT-scFv) acting as a functional internal image of a microbicidal, wide-spectrum yeast killer toxin (KT) were synthesized and studied for their antimicrobial activity by using the KT-susceptible Candida albicans as model organism. A decapeptide containing the first three amino acids (SAS) of the light chain CDR1 was selected and optimized by alanine replacement of a single residue. This peptide exe...

  8. Specific Conjugation of the Hinge Region for Homogeneous Preparation of Antibody Fragment-Drug Conjugate: A Case Study for Doxorubicin-PEG-anti-CD20 Fab' Synthesis.

    Science.gov (United States)

    Zhou, Zhan; Zhang, Jing; Zhang, Yan; Ma, Guanghui; Su, Zhiguo

    2016-01-20

    Conventional preparation strategies for antibody-drug conjugates (ADCs) result in heterogeneous products with various molecular sizes and species. In this study, we developed a homogeneous preparation strategy by site-specific conjugation of the anticancer drug with an antibody fragment. The model drug doxorubicin (DOX) was coupled to the Fab' fragment of anti-CD20 IgG at its permissive sites through a heterotelechelic PEG linker, generating an antibody fragment-drug conjugate (AFDC). Anti-CD20 IgG was digested and reduced specifically with β-mercaptoethylamine to generate the Fab' fragment with two free mercapto groups in its hinge region. Meanwhile, DOX was conjugated with α-succinimidylsuccinate ω-maleimide polyethylene glycol (NHS-PEG-MAL) to form MAL-PEG-DOX, which was subsequently linked to the free mercapto containing Fab' fragment to form a Fab'-PEG-DOX conjugate. The dual site-specific bioconjugation was achieved through the combination of highly selective reduction of IgG and introduction of heterotelechelic PEG linker. The resulting AFDC provides an utterly homogeneous product, with a definite ratio of one fragment to two drugs. Laser confocal microscopy and cell ELISA revealed that the AFDC could accumulate in the antigen-positive Daudi tumor cell. In addition, the Fab'-PEG-DOX retained appreciable targeting ability and improved antitumor activity, demonstrating an excellent therapeutic effect on the lymphoma mice model for better cure rate and significantly reduced side effects.

  9. Immunocytochemistry by electron spectroscopic imaging using well defined boronated monovalent antibody fragments.

    Science.gov (United States)

    Kessels, M M; Qualmann, B; Sierralta, W D

    1996-01-01

    Contributing to the rapidly developing field of immunoelectron microscopy a new kind of markers has been created. The element boron, incorporated as very stable carborane clusters into different kinds of peptides, served as a marker detectable by electron spectroscopic imaging (ESI)--an electron microscopic technique with high-resolution potential. Covalently linked immunoreagents conspicuous by the small size of both antigen recognizing part and marker moiety are accessible by using peptide concepts for label construction and their conjugation with Fab' fragments. Due to a specific labeling of the free thiol groups of the Fab' fragments, the antigen binding capacity was not affected by the attachment of the markers and the resulting immunoprobes exhibited an elongated shape with the antigen combining site and the label located at opposite ends. The labeling densities observed with these reagents were found to be significantly higher than those obtained by using conventional colloidal gold methods. Combined with digital image processing and analysis systems, boron-based ESI proved to be a powerful approach in ultrastructural immunocytochemistry employing pre- and post-embedding methods.

  10. High affinity human antibody fragments to dengue virus non-structural protein 3.

    Directory of Open Access Journals (Sweden)

    Nicole J Moreland

    Full Text Available BACKGROUND: The enzyme activities catalysed by flavivirus non-structural protein 3 (NS3 are essential for virus replication. They are distributed between the N-terminal protease domain in the first one-third and the C-terminal ATPase/helicase and nucleoside 5' triphosphatase domain which forms the remainder of the 618-aa long protein. METHODOLOGY/PRINCIPAL FINDINGS: In this study, dengue full-length NS3 protein with residues 49 to 66 of NS2B covalently attached via a flexible linker, was used as bait in biopanning with a naïve human Fab phage-display library. Using a range of truncated constructs spanning the NS2B cofactor region and the full-length NS3, 10 unique Fab were identified and characterized. Of these, monoclonal Fab 3F8 was shown to bind α3″ (residues 526 through 531 within subdomain III of the helicase domain. The antibody inhibits the ATPase and helicase activites of NS3 in biochemical assays and reduces DENV replication in HEK293 cells that were previously transfected with Fab 3F8 compared with mock transfected cells. CONCLUSIONS/SIGNIFICANCE: Antibodies such as 3F8 are valuable tools for studying the molecular mechanisms of flaviviral replication and for the monospecific detection of replicating dengue virus in vivo.

  11. 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

  12. Selective targeting of tumour neovasculature by a radiohalogenated human antibody fragment specific for the ED-B domain of fibronectin

    International Nuclear Information System (INIS)

    Demartis, S.; Tarli, L.; Neri, D.; Borsi, L.; Zardi, L.

    2001-01-01

    Angiogenesis is a characteristic feature of many aggressive tumours and other disorders. Antibodies capable of binding to new blood vessels, but not to mature vessels, could be used as selective targeting agents for immunoscintigraphic and radioimmunotherapeutic applications. Here we show that scFv(L19), a recombinant human antibody fragment with sub-nanomolar affinity for the ED-B domain of fibronectin, a marker of angiogenesis, can be stably labelled with iodine-125 and astatine-211 with full retention of immunoreactivity, using a trimethyl-stannyl benzoate bifunctional derivative. Biodistribution studies in mice bearing two different types of tumour grafted subcutaneously, followed by ex vivo micro-autoradiographic analysis, revealed that scFv(L19) rapidly localises around tumour blood vessels, but not around normal vessels. Four hours after intravenous injection of the stably radioiodinated scFv(L19), tumour to blood ratios were 6:1 in mice bearing the F9 murine teratocarcinoma and 9:1 in mice bearing an FE8 rat sarcoma. As expected, all other organs (including kidney) contained significantly less radioactivity than the tumour. Since the ED-B domain of fibronectin has an identical sequence in mouse and man, scFv(L19) is a pan-species antibody and the results presented here suggest clinical utility of radiolabelled scFv(L19) for the scintigraphic detection of angiogenesis in vivo. Furthermore, it should now be possible to investigate scFv(L19) for the selective delivery of 211 At to the tumour neovasculature, causing the selective death of tumour endothelial cells and tumour collapse. (orig.)

  13. Study of the viability of technetium-99m labeling of whole antimyosin antibody and its fragment: development of radiopharmaceutical for cardiac survey

    International Nuclear Information System (INIS)

    Carvalho, Guilherme Luiz de Castro

    2007-01-01

    In the acute myocardium infarction, the myocytes cell membrane loses its integrity, allowing the influx of extracellular macromolecules such as circulating antibody into the damaged cell. The use of the specific antibodies against cardiac myosin labeled with 99m Tc allows to determine the localization and extension of myocardial infarction. The purpose of this work was to study the viability of labeling of the antimyosin monoclonal antibody and its fragment F(ab')2 with 99m Tc. Because of the high cost of antimyosin antibody, others antibodies were used to optimize the methodology and the best condition was used for antimyosin antibody. The intact antibody was cleaved by pepsin to produce F(ab') 2 fragment. The F(ab') 2 and the intact antibody were reduced by treatment with Dithiothreitol (DTT) and 2-Mercaptoethanol (2-ME) and labeled with 99m Tc by direct method. Different concentrations of reductant, mixing conditions and incubation times were studied. In the standard condition, incubation at molar ratio 1:1000 (antibody:reducing agent) at room temperature for 30 minutes with continuous rotation (850 rpm), 13.28 - SH groups were formed per molecule. It was studied the influence of p H, of the concentration of stannous chloride (Sn 2+ ) and incubation time in the labeling condition. The better radiochemical yield (90.06 +- 1.53%) was obtained using 2.5 μg of Sn 2+ in p H 4.5 for 60 minutes. The labeling of the fragment F(ab') 2 did not present satisfactory results because of the low yield of the digestion. After purification by PD-10, the biodistribution study was performed and showed that the intact antimyosin antibody labeled with 99m Tc presented fast kinetic compatible with the biodistribution of an intact antibody labeled with 99m Tc. Scintigraphy image of the animal with myocardial infarction was obtained and compared with the image of a normal animal. The studies allow to conclude that the use of fragment F(ab') 2 are not viable, but the use of the labeled

  14. 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.

  15. Detection and quantification of microcystins (cyanobacterial hepatotoxins) with recombinant antibody fragments isolated from a naïve human phage display library.

    Science.gov (United States)

    McElhiney, J; Lawton, L A; Porter, A J

    2000-12-01

    Single-chain antibody fragments against the cyanobacterial hepatotoxin microcystin-LR were isolated from a naive human phage display library and expressed in Escherichia coli. In competition enzyme-linked immunosorbent assay (ELISA), the most sensitive antibody clone selected from the library detected free microcystin-LR with an IC(50) value of 4 microM. It was found to cross react with three other microcystin variants - microcystin-RR, microcystin-LW and microcystin-LF - and detected microcystins in extracts of the cyanobacterium Microcystis aeruginosa, found to contain the toxins by high-performance liquid chromatography (HPLC). The quantification of microcystins in these extracts by ELISA and HPLC showed good correlation. Although the antibody isolated in this study was considerably less sensitive than the polyclonal and monoclonal antibodies already available for microcystin detection, phage display technology represents a cheaper, more rapid alternative for the production of anti-microcystin antibodies than the methods currently in use.

  16. Kinetics and tissue distribution of the radiolabeled chimeric monoclonal antibody MOv18 IgG and F(ab')2 fragments in ovarian carcinoma patients

    NARCIS (Netherlands)

    Buist, M. R.; Kenemans, P.; den Hollander, W.; Vermorken, J. B.; Molthoff, C. J.; Burger, C. W.; Helmerhorst, T. J.; Baak, J. P.; Roos, J. C.

    1993-01-01

    Twenty-four patients suspected of having ovarian carcinoma received i.v. injection with a combination of radiolabeled intact IgG (1 mg) and F(ab')2 fragments (1 mg) of the chimeric monoclonal antibody MOv18, each form labeled with 1.85 MBq 131I or 125I. Laparotomy was performed either 2 or 6 days

  17. Pharmacokinetics and tumor targeting of 131I-labeled F(ab')2 fragments of the chimeric monoclonal antibody G250: preclinical and clinical pilot studies.

    NARCIS (Netherlands)

    Brouwers, A.H.; Mulders, P.F.A.; Oosterwijk, E.; Buijs, W.C.A.M.; Corstens, F.H.M.; Boerman, O.C.; Oyen, W.J.G.

    2004-01-01

    INTRODUCTION: Clinical and animal studies of chimeric monoclonal antibody G250 (moAb cG250) for the targeting of clear-cell renal cell carcinoma (RCC), to date, have been with the intact IgG form. To determine whether F(ab')2 fragments are more suited for radioimmunotherapy (RIT) than intact IgG,

  18. Radioimmunoimaging of human colon carcinoma grafted into nudemice using 131I-labeled monoclonal anticea antibody and its F(ab')2 fragments

    International Nuclear Information System (INIS)

    Liu Guangda

    1988-01-01

    131 I-labeled monoclonal anti-CEA antibody and its F(ab') 2 fragments were injected into nude mice bearing human colon carcinoma xenografts for tumor localization and radioimmunoimaging studies. Transplanted tumors were visualized in 12 hours after injection of the labeled anti-CEA or its F(ab') 2 by gamma camera. Biodistribution data indicated that F(ab') 2 fragments were cleared more rapidly from blood (T 1/2 = 13.3 h for F(ab') 2 , T 1/2 = 21.1 h for intact antibody) over 6-24 h and had higher tumor blood ratios. The intact antibody was concentrated in the tumor better than F(ab') 2 . In double-label experiments, a nonspecific localization of the control ( 125 I-labeled anti-HCG) in the tumor was also observed

  19. Antibody guided targeting of non-small cell lung cancer using 111In-labeled HMFG1 F(ab')2 fragments

    International Nuclear Information System (INIS)

    Kalofonos, H.P.; Sivolapenko, G.B.; Courtenay-Luck, N.S.

    1988-01-01

    Immunoscintigraphy using F(ab')2 fragments of tumor-associated monoclonal antibody HMFG1 was performed in 14 patients with primary and metastatic non-small cell carcinoma of lung cancer. The antibody was conjugated with diethylenetriamine pentaacetic acid and labeled with 111 In. Quality control studies showed efficient incorporation of 111 In onto antibody (5 mCi/mg), no significant loss of immunoreactivity, and in vitro and in vivo stability. The optimal time for imaging was between 48 and 72 h. Following i.v. administration, serum activity fell rapidly (t1/2a = 2.5 +/- 1.3 (SD) h; t1/2b = 42 +/- 4.5 h). The majority of the radioactivity was associated with the plasma and not with the blood cells. All patients had a significant concentration of 111 In in the liver (approximately 20% of the injected dose, 48 h postadministration). No toxicity was encountered. No human antimurine-IgG antibody was detected in any of the patients within 4 months of follow-up, even in patients receiving two administrations of F(ab')2 fragments. Localization of all primary lesions and the majority (80%) of metastatic lesions was achieved. Seven of 14 patients were also studied using a 111 In-labeled nonspecific antibody (Fab')2 fragment (4C4). In three patients the specificity index was higher than the other four (P less than 0.05). We conclude that although successful targeting of 111 In-labeled (Fab')2 fragments of HMFG1 can be achieved in patients with non-small cell carcinoma of lung, observable tumor localization can also be achieved using a nonspecific antibody

  20. Effect of polyethylene glycol conjugation on conformational and colloidal stability of a monoclonal antibody antigen-binding fragment (Fab').

    Science.gov (United States)

    Roque, Cristopher; Sheung, Anthony; Rahman, Nausheen; Ausar, S Fernando

    2015-02-02

    We have investigated the effects of site specific "hinge" polyethylene glycol conjugation (PEGylation) on thermal, pH, and colloidal stability of a monoclonal antibody antigen-binding fragment (Fab') using a variety of biophysical techniques. The results obtained by circular dichroism (CD), ultraviolet (UV) absorbance, and fluorescence spectroscopy suggested that the physical stability of the Fab' is maximized at pH 6-7 with no apparent differences due to PEGylation. Temperature-induced aggregation experiments revealed that PEGylation was able to increase the transition temperature, as well as prevent the formation of visible and subvisible aggregates. Statistical comparison of the three-index empirical phase diagram (EPD) revealed significant differences in thermal and pH stability signatures between Fab' and PEG-Fab'. Upon mechanical stress, micro-flow imaging (MFI) and measurement of the optical density at 360 nm showed that the PEG-Fab' had significantly higher resistance to surface-induced aggregation compared to the Fab'. Analysis of the interaction parameter, kD, indicated repulsive intermolecular forces for PEG-Fab' and attractive forces for Fab'. In conclusion, PEGylation appears to protect Fab' against thermal and mechanical stress-induced aggregation, likely due to a steric hindrance mechanism.

  1. Measuring Response to Therapy by Near-Infrared Imaging of Tumors Using a Phosphatidylserine-Targeting Antibody Fragment

    Directory of Open Access Journals (Sweden)

    Jian Gong

    2013-06-01

    Full Text Available Imaging tumors and their response to treatment could be a valuable biomarker toward early assessment of therapy in patients with cancer. Phosphatidylserine (PS is confined to the inner leaflet of the plasma membrane in normal cells but is externalized on tumor vascular endothelial cells (ECs and tumor cells, and PS exposure is further enhanced in response to radiation and chemotherapy. In the present study, we evaluated the potential of a PS-targeting human F(ab'2 antibody fragment, PGN650, to detect exposure of PS in tumor-bearing mice. Tumor uptake of PGN650 was measured by near-infrared optical imaging in human tumor xenografts in immunodeficient mice. PGN650 specifically targeted tumors and was shown to target CD31-positive ECs and tumor cells. Tumor uptake of PGN650 was significantly higher in animals pretreated with docetaxel. The peak tumor to normal tissue (T/N ratio of probe was observed at 24 hours postinjection of probe, and tumor binding was detected for at least 120 hours. In repeat dose studies, PGN650 uptake in tumors was significantly higher following pretreatment with docetaxel compared to baseline uptake prior to treatment. PGN650 may be a useful probe to detect PS exposed in tumors and to monitor enhanced PS exposure to optimize therapeutic agents to treat tumors.

  2. Immunodeficiency syndrome in a 3-year-old llama.

    OpenAIRE

    Sivasankar, M

    1999-01-01

    An adult, castrated male llama was presented for evaluation of a chronic respiratory problem. Complete blood analyses indicated a leukopenia and hypoproteinemia. Radial immunodiffusion, bone marrow core, and lymph node biopsies supported a tentative diagnosis of juvenile llama immunodeficiency syndrome. This diagnosis was confirmed by postmortem findings.

  3. 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

  4. Modified cytokeratins expressed on the surface of carcinoma cells undergo endocytosis upon binding of human monoclonal antibody and its recombinant Fab fragment

    DEFF Research Database (Denmark)

    Ditzel, H J; Garrigues, U; Andersen, C B

    1997-01-01

    display selection and the human Fab fragment was expressed in bacteria. Analysis by confocal laser scanning microscopy demonstrated that COU-1 bound in a uniform punctate pattern to the surface of viable carcinoma cells stained at 4 degrees C, and binding increased significantly when cells were cultured...... was significantly reduced. Similar results were obtained using intact IgM COU-1 and the recombinant Fab fragment. Immunohistological studies indicated that COU-1, in contrast to murine monoclonal antibodies against normal cytokeratin 8 and 18, could differentiate between malignant and normal colon epithelia...

  5. Isolation of Mal d 1 and Api g 1 - specific recombinant antibodies from mouse IgG Fab fragment libraries - Mal d 1-specific antibody exhibits cross-reactivity against Bet v 1.

    Science.gov (United States)

    Haka, Jaana; Niemi, Merja H; Iljin, Kristiina; Reddy, Vanga Siva; Takkinen, Kristiina; Laukkanen, Marja-Leena

    2015-05-27

    Around 3-5% of the population suffer from IgE-mediated food allergies in Western countries and the number of food-allergenic people is increasing. Individuals with certain pollen allergies may also suffer from a sensitisation to proteins in the food products. As an example a person sensitised to the major birch pollen allergen, Bet v 1, is often sensitised to its homologues, such as the major allergens of apple, Mal d 1, and celery, Api g 1, as well. Development of tools for the reliable, sensitive and quick detection of allergens present in various food products is essential for allergic persons to prevent the consumption of substances causing mild and even life-threatening immune responses. The use of monoclonal antibodies would ensure the specific detection of the harmful food content for a sensitised person. Mouse IgG antibody libraries were constructed from immunised mice and specific recombinant antibodies for Mal d 1 and Api g 1 were isolated from the libraries by phage display. More detailed characterisation of the resulting antibodies was carried out using ELISA, SPR experiments and immunoprecipitation assays. The allergen-specific Fab fragments exhibited high affinity towards the target recombinant allergens. Furthermore, the Fab fragments also recognised native allergens from natural sources. Interestingly, isolated Mal d 1-specific antibody bound also to Bet v 1, the main allergen eliciting the cross-reactivity syndrome between the birch pollen and apple. Despite the similarities in Api g 1 and Bet v 1 tertiary structures, the isolated Api g 1-specific antibodies showed no cross-reactivity to Bet v 1. Here, high-affinity allergen-specific recombinant antibodies were isolated with interesting binding properties. With further development, these antibodies can be utilised as tools for the specific and reliable detection of allergens from different consumable products. This study gives new preliminary insights to elucidate the mechanism behind the pollen

  6. Taxonomy Icon Data: llama [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available llama Lama glama Chordata/Vertebrata/Mammalia/Theria/Eutheria/Artiodactyla Lama_glama_L.png Lama_glama_NL.png Lama_glama_S.png Lama_glama..._NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Lama+glam...a&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Lama+glama&t=NL http://biosciencedbc.jp/t...axonomy_icon/icon.cgi?i=Lama+glama&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Lama+glama&t=NS ...

  7. PET Imaging of Abdominal Aortic Aneurysm with 64Cu-Labeled Anti-CD105 Antibody Fab Fragment.

    Science.gov (United States)

    Shi, Sixiang; Orbay, Hakan; Yang, Yunan; Graves, Stephen A; Nayak, Tapas R; Hong, Hao; Hernandez, Reinier; Luo, Haiming; Goel, Shreya; Theuer, Charles P; Nickles, Robert J; Cai, Weibo

    2015-06-01

    The critical challenge in abdominal aortic aneurysm (AAA) research is the accurate diagnosis and assessment of AAA progression. Angiogenesis is a pathologic hallmark of AAA, and CD105 is highly expressed on newly formed vessels. Our goal was to use (64)Cu-labeled anti-CD105 antibody Fab fragment for noninvasive assessment of angiogenesis in the aortic wall in a murine model of AAA. Fab fragment of TRC105, a mAb that specifically binds to CD105, was generated by enzymatic papain digestion and conjugated to NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid) for (64)Cu labeling. The binding affinity/specificity of NOTA-TRC105-Fab was evaluated by flow cytometry and various ex vivo studies. BALB/c mice were anesthetized and treated with calcium phosphate to induce AAA and underwent weekly PET scans using (64)Cu-NOTA-TRC105-Fab. Biodistribution and autoradiography studies were also performed to confirm the accuracy of PET results. NOTA-TRC105-Fab exhibited high purity and specifically bound to CD105 in vitro. Uptake of (64)Cu-NOTA-TRC105-Fab increased from a control level of 3.4 ± 0.1 to 9.5 ± 0.4 percentage injected dose per gram (%ID/g) at 6 h after injection on day 5 and decreased to 7.2 ± 1.4 %ID/g on day 12, which correlated well with biodistribution and autoradiography studies (i.e., much higher tracer uptake in AAA than normal aorta). Of note, enhanced AAA contrast was achieved, due to the minimal background in the abdominal area of mice. Degradation of elastic fibers and highly expressed CD105 were observed in ex vivo studies. (64)Cu-NOTA-TRC105-Fab cleared rapidly through the kidneys, which enabled noninvasive PET imaging of the aorta with enhanced contrast and showed increased angiogenesis (CD105 expression) during AAA. (64)Cu-NOTA-TRC105-Fab PET may potentially be used for future diagnosis and prognosis of AAA. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  8. Bone marrow dosimetry in rats using direct tissue counting after injection of radio-iodinated intact monoclonal antibodies or F(ab')2 fragments

    International Nuclear Information System (INIS)

    Buchegger, F.; Chalandon, Y.; Pelegrin, A.; Hardman, N.; Mach, J.P.

    1991-01-01

    Normal rats were injected intravenously with 131I- and 125I-labeled intact murine and chimeric mouse-human monoclonal antibodies directed against carcinoembryonic antigen or with the corresponding F(ab')2 fragments. At different times after injection, individual animals were killed and radioactivity of blood and major organs, including bones and bone marrow, was determined. Ratios comparing radioactivity concentration in different tissues with that of bone marrow were calculated and found to remain stable during several effective half-lives of the antibodies. Mean bone marrow radioactivity was 35% (range, 29%-40%) of that of blood and 126% (range, 108%-147%) of that of liver after injection of intact Mabs or F(ab')2 fragments. In nude rats bearing human colon carcinoma xenografts producing carcinoembryonic antigen, relative bone marrow radioactivity was slightly lower than that in normal rats

  9. High contrast tumor imaging with radio-labeled antibody Fab fragments tailored for optimized pharmacokinetics via PASylation.

    Science.gov (United States)

    Mendler, Claudia T; Friedrich, Lars; Laitinen, Iina; Schlapschy, Martin; Schwaiger, Markus; Wester, Hans-Jürgen; Skerra, Arne

    2015-01-01

    Although antigen-binding fragments (Fabs) of antibodies constitute established tracers for in vivo radiodiagnostics, their functionality is hampered by a very short circulation half-life. PASylation, the genetic fusion with a long, conformationally disordered amino acid chain comprising Pro, Ala and Ser, provides a convenient way to expand protein size and, consequently, retard renal filtration. Humanized αHER2 and αCD20 Fabs were systematically fused with 100 to 600 PAS residues and produced in E. coli. Cytofluorimetric titration analysis on tumor cell lines confirmed that antigen-binding activities of the parental antibodies were retained. The radio-iodinated PASylated Fabs were studied by positron emission tomography (PET) imaging and biodistribution analysis in mouse tumor xenograft models. While the unmodified αHER2 and αCD20 Fabs showed weak tumor uptake (0.8% and 0.2% ID/g, respectively; 24 h p.i.) tumor-associated radioactivity was boosted with increasing PAS length (up to 9 and 26-fold, respectively), approaching an optimum for Fab-PAS400. Remarkably, 6- and 5-fold higher tumor-to-blood ratios compared with the unmodified Fabs were measured in the biodistribution analysis (48 h p.i.) for αHER2 Fab-PAS100 and Fab-PAS200, respectively. These findings were confirmed by PET studies, showing high imaging contrast in line with tumor-to-blood ratios of 12.2 and 5.7 (24 h p.i.) for αHER2 Fab-PAS100 and Fab-PAS200. Even stronger tumor signals were obtained with the corresponding αCD20 Fabs, both in PET imaging and biodistribution analysis, with an uptake of 2.8% ID/g for Fab-PAS100 vs. 0.24% ID/g for the unmodified Fab. Hence, by engineering Fabs via PASylation, plasma half-life can be tailored to significantly improve tracer uptake and tumor contrast, thus optimally matching reagent/target interactions.

  10. Targeting osteomyelitis with complete [99mTc]besilesomab and fragmented [99mTc]sulesomab antibodies: kinetic evaluations

    International Nuclear Information System (INIS)

    GRATZ, Stefan; KEMKE, Bendix; KEIZE, Patrik; KAMPEN, Wim U.; LUSTER, Markus; HÖFFKEN, Helmut

    2016-01-01

    The aim of this retrospective study was to compare the targeting of “pure” osteomyelitis (i.e., without surrounding soft tissue infection) by directly 99mTc-labelled complete immunoglobulin G (IgG) monoclonal antibody (MAb) ([99mTc]besilesomab) and by directly 99mTc-labelled fragment antigen-binding (FAb) MAb ([99mTc]sulesomab) in relation to their kinetic fate. A total of 73 patients with “pure” osteomyelitis were examined with [99mTc]besilesomab, (Scintimun®, IBA/CIS bio international, Saclay, France; N.=38) and [99mTc]sulesomab (LeukoScan®, Immunomedics Inc., Morris Plains, NJ, USA; N.=35). Kinetic data were deduced from whole-body and single-photon emission computed tomographic scans, performed 10 minutes to 24 hour p.i. (region-of-interest technique [ROI]). In targeting “pure” osteomyelitis, sensitivities at 1-4 hours were found to be higher for [99mTc]sulesomab (44% and 80% for [99mTc]besilesomab and [99mTc]sulesomab, respectively) but at significantly lower target/background (T/B) ratios than with [99mTc]besilesomab (1.8±0.3 versus 1.4±0.5 for [99mTc]besilesomab and [99mTc]sulesomab respectively; P<0.01). With [99mTc]besilesomab, there was a continuous osteomyelitis uptake over 24 hours, whereas with [99mTc]sulesomab, the maximal uptake occurred mostly within 1-4 hours, with subsequent clearance being slower for antigen-bound activity than for nonspecific background. Hence, diagnosis was possible mostly after 4h with [99mTc]sulesomab but often not before 24 hours with [99mTc]besilesomab, the later increasing significantly (P<0.01) in sensitivity (87% and 84% for [99mTc]besilesomab and [99mTc]sulesomab, respectively). These results show that the higher sensitivity of [99mTc]sulesomab in osteomyelitis targeting at earlier p.i. times does not rely on an increased antibody uptake but on a more rapid clearance of nonspecific background activity due to faster metabolism and excretion. Intact [99mTc]besilesomab show a slow, continuous uptake

  11. Identification and characterization of a thermally cleaved fragment of monoclonal antibody-A detected by sodium dodecyl sulfate-capillary gel electrophoresis.

    Science.gov (United States)

    Kubota, Kei; Kobayashi, Naoki; Yabuta, Masayuki; Ohara, Motomu; Naito, Toyohiro; Kubo, Takuya; Otsuka, Koji

    2017-06-05

    This report describes a novel, comprehensive approach to identifying a fragment peak of monoclonal antibody-A (mAb-A), detected by sodium dodecyl sulfate-capillary gel electrophoresis (SDS-cGE). The fragment migrated close to the internal standard (10kDa marker) of SDS-cGE and increased about 0.5% under a 25°C condition for 6 months. Generally, identification of fragments observed in SDS-cGE is challenging to carry out due to the difficulty of collecting analytical amounts of fractionations from the capillary. In this study, in-gel digestion peptide mapping and reversed phase liquid chromatography-mass spectrometry (RPLC-MS) were employed to elucidate the structure of the fragment. In addition, a Gelfree 8100 fractionation system was newly introduced to collect the fragment and the fraction was applied to the structural analysis of a mAb for the first time. These three analytical methods showed comparable results, proving that the fragment was a fraction of heavy chain HC1-104. The fragment contained complementarity determining regions (CDRs), which are significant to antigen binding, and thus would affect the efficacy of mAb-A. In addition, SDS-cGE without the 10kDa marker was demonstrated to clarify the increased amount of the fragment, and the experiment revealed that the fragment increases 0.2% per year in storage at 5°C. The combination of the three analytical methodologies successfully identified the impurity peak detected by SDS-cGE, providing information critical to assuring the quality and stability of the biotherapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. 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.

  13. Radioimmunoimaging of human breast carcinoma xenografts in nude mouse model with 111In-labeled new monoclonal antibody EBA-1 and F(ab')2 fragments

    International Nuclear Information System (INIS)

    Yemul, Shrishailam; Leon, J.A.; Pozniakoff, Ted; Esser, P.D.; Estabrook, Alison; Met-Path Inc., Teterboro, NJ

    1993-01-01

    Radioimmunoimaging characteristics of a new monoclonal antibody EBA-1 and its F(ab') 2 fragments utilizing nu/nu mice bearing human breast carcinoma xenografts are described. 111 In-DPTA conjugates of EBA-1 localized with tumor/blood ratios of 0.99 ± 0.10 (P 2 radioconjugates at 48 h. These results suggest that EBA-1 and its F(ab') 2 might be useful reagents in radioimmunoimaging and radioimmunotherapy. (author)

  14. How protein recognizes ladder-like polycyclic ethers. Interactions between ciguatoxin (CTX3C) fragments and its specific antibody 10C9.

    Science.gov (United States)

    Ui, Mihoko; Tanaka, Yoshikazu; Tsumuraya, Takeshi; Fujii, Ikuo; Inoue, Masayuki; Hirama, Masahiro; Tsumoto, Kouhei

    2008-07-11

    Ciguatoxins are a family of marine toxins composed of transfused polycyclic ethers. It has not yet been clarified at the atomic level on the pathogenic mechanism of these toxins or the interaction between a polycyclic ether compounds and a protein. Using the crystal structures of anti-ciguatoxin antibody 10C9 Fab in ligand-free form and in complexes with ABCD-ring (CTX3C-ABCD) and ABCDE-ring (CTX3C-ABCDE) fragments of the antigen CTX3C at resolutions of 2.6, 2.4, and 2.3 angstroms, respectively, we elucidated the mechanism of the interaction between the polycyclic ethers and the antibody. 10C9 Fab has an extraordinarily large and deep binding pocket at the center of the variable region, where CTX3C-ABCD or CTX3C-ABCDE binds longitudinally in the pocket via hydrogen bonds and van der Waals interactions. Upon antigen-antibody complexation, 10C9 Fab adjusts to the antigen fragments by means of rotational motion in the variable region. In addition, the antigen fragment lacking the E-ring induces a large motion in the constant region. Consequently, the thermostability of 10C9 Fab is enhanced by 10 degrees C upon complexation with CTX3C-ABCDE but not with CTX3C-ABCD. The crystal structures presented in this study also show that 10C9 Fab recoginition of CTX3C antigens requires molecular rearrangements over the entire antibody structure. These results further expand the fundamental understanding of the mechanism by which ladder-like polycyclic ethers are recognized and may be useful for the design of novel therapeutic agents by antibodies, marine toxins, or new diagnostic reagents for the detection and targeting of members of the polycyclic ether family.

  15. Tumour localization and pharmacokinetics of iodine-125 human monoclonal IgM antibody (COU-1) and its monomeric and half-monomeric fragments analysed in nude mice grafted with human tumour

    International Nuclear Information System (INIS)

    Ditzel, H.; Erb, K.; Rasmussen, J.W.; Jensenius, J.C.

    1992-01-01

    Human monoclonal IgM antibodies reactive with cancer-associated antigens may not have the optimal imaging capability due to their large size. Fragmentation of human IgM is less than straight-forward due to the loss of immunoreactivity. From the human monoclonal IgM antibody COU-1 we have prepared monomeric and half-monomeric fragments, which retain the ability to bind to colon cancer cells in vitro. The pharmacokinetics and tumour localization were evaluated in nude mice bearing human colon adenocarcinoma and human melanoma grafts. Faster clearance from the circulation was seen for the smaller half-monomeric fragment with a half-life (rapid phase/slow phase) of 2 h/16 h compared with the intact antibody, 4 h/25 h, and the monomeric fragment, 3 h/27 h. Intact COU-1 as well as the fragments accumulated in the colon tumour graft. Higher amounts of radioactivity were found in the colon tumour as compared to normal organs for intact COU-1 at days 4 and 6, for the monomeric fragment at day 4, and for the half-monomeric fragment at day 2 after injection. This investigation demonstrates the favourable biodistribution of the half monomeric COU-1 fragment. The fast clearance of this fragment resulted in a tumour-to-muscle ratio as high as 22 on day 2 after injection. Also, only this fragment gave a positive tumour-to-blood ratio. Normal IgM and its fragments were used as controls. Radioimmunoscintigraphy demonstrated the colon tumour discriminatory properties of each of the three iodine-labelled antibody preparations. The results compare favourably with previously reported investigations of the localization of human monoclonal antibodies and suggest that fragments of human monoclonal IgM antibodies may be useful tools for the immunodetection of cancer in patients. (orig.)

  16. Orientation of llama antibodies strongly increases sensitivity of biosensors

    NARCIS (Netherlands)

    Trilling, A.K.; Hesselink, T.; Houwelingen, van A.; Cordewener, J.H.G.; Jongsma, M.A.; Schoffelen, S.; Hest, van J.C.M.; Zuilhof, J.T.; Beekwilder, J.

    2014-01-01

    Sensitivity of biosensors depends on theorientation of bio-receptors on the sensor surface.The objective of this study was to organize bio-receptors on surfaces in a way that their analyte binding site is exposed to the analyte solution. VHH proteins recognizing foot-and-mouth disease virus (FMDV)

  17. Orientation of llama antibodies strongly increases sensitivity of biosensors.

    Science.gov (United States)

    Trilling, Anke K; Hesselink, Thamara; van Houwelingen, Adèle; Cordewener, Jan H G; Jongsma, Maarten A; Schoffelen, Sanne; van Hest, Jan C M; Zuilhof, Han; Beekwilder, Jules

    2014-10-15

    Sensitivity of biosensors depends on the orientation of bio-receptors on the sensor surface. The objective of this study was to organize bio-receptors on surfaces in a way that their analyte binding site is exposed to the analyte solution. VHH proteins recognizing foot-and-mouth disease virus (FMDV) were used for making biosensors, and azides were introduced in the VHH to function as bioorthogonal reactive groups. The importance of the orientation of bio-receptors was addressed by comparing sensors with randomly oriented VHH (with multiple exposed azide groups) to sensors with uniformly oriented VHH (with only a single azide group). A surface plasmon resonance (SPR) chip exposing cyclooctyne was reacted to azide functionalized VHH domains, using click chemistry. Comparison between randomly and uniformly oriented bio-receptors showed up to 800-fold increase in biosensor sensitivity. This technique may increase the containment of infectious diseases such as FMDV as its strongly enhanced sensitivity may facilitate early diagnostics. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Method of stably radiolabeling antibodies with technetium and rhenium

    International Nuclear Information System (INIS)

    Paik, C.H.; Reba, R.C.; Eckelman, W.C.

    1987-01-01

    A method is described for labeling antibodies or antibody fragments with radionuclides of technetium or rhenium to obtain stable labeling, comprising: reacting a reduced radioisotope of technetium or rhenium with an antibody or antibody fragment, or a diethylenetriaminepentaacetic acid conjugated antibody or antibody fragment, in the presence of free or carrier-bound diethylenetriaminepentaacetic acid (DTPA). The amount of DTPA is sufficient to substantially completely inhibit binding of the reduced technetium or rhenium to nonstable binding sites of the antibody or antibody fragment, or the DTPA-conjugated antibody or antibody fragment. The resultant stably labeled antibody or antibody fragment, or DTPA[conjugated antibody or antibody fragment is recovered

  19. Cutaneous angiomatosis in a llama (Lama glama).

    Science.gov (United States)

    Luppi, M M; Malta, M C C; Ocarino, N M; França, S A; Serakides, R

    2010-01-01

    Cutaneous angiomatosis was diagnosed in an adult female llama (Lama glama). Lesions were raised or plaque-like, erythematous, firm to soft in consistency and were observed on the face and skin of the axillary, abdominal, perineal and inguinal regions. The lesions were not painful or pruritic. Microscopical examination revealed an irregular parakeratotic lamellar hyperkeratosis associated with diffuse proliferation of arterioles and venules in the superficial dermis. Immunohistochemical analysis determined that the cells forming these vessels and perivascular cells expressed factor VIII-related antigen, vascular endothelial growth factor (VEGF), CD31 and smooth-muscle alpha-actin. These studies confirmed the diagnosis of cutaneous angiomatosis. Copyright 2009 Elsevier Ltd. All rights reserved.

  20. Platelet aggregation responses in clinically healthy adult llamas.

    Science.gov (United States)

    Gilbert, Rosanne M; Bird, Karyn E; Kutzler, Michelle A

    2009-03-01

    Limited information exists regarding hemostasis in camelids despite the importance of platelet function testing in the accurate identification of platelet disorders. As further importation of llamas to North America is restricted, variability in breeding stock will continue to decrease, potentially leading to an increase in heritable bleeding disorders. The objective of this study was to measure platelet aggregation responses in clinically healthy llamas and provide baseline data to which abnormal platelet function may be compared in the future. Blood samples were collected from 39 healthy adult llamas, citrated, and centrifuged to produce platelet-rich plasma (PRP). Within 4 hours of the blood draw, 20 microL of each agonist reagent were added to 180 microL of PRP. Final concentrations of agonists were 2 x 10(-5) M ADP, 0.19 mg collagen/mL PRP, 1 x 10(-4) M epinephrine, and 500 microg arachidonic acid/mL PRP. Llama platelets were most responsive to ADP and collagen, with a maximum percent aggregation (mean+/-SD) of 71.3+/-18.6% and 55.8+/-19% and aggregation rates of 9.5+/-3.9 and 6.7+/-3.7 cm/min, respectively. Llama platelet aggregation in response to epinephrine and arachidonic acid was minimal to absent. This study is the first of its kind to establish baseline values for platelet aggregation in healthy adult llamas.

  1. Immunoscintigraphy of adenocarcinomas by means of 111In-labelled F(ab')2 fragments of anti-CEA monoclonal antibody F023C5

    International Nuclear Information System (INIS)

    Riva, P.; Paganelli, G.; Callegaro, L.

    1988-01-01

    F(ab') 2 fragments of F023C5, an anti-CEA monoclonal antibody, were conjugated to diethylenetriamine pentaacetic acid (DTPA) and converted into a ready to use reagent for instant 111 In-labelling. The resulting 111 In radiopharmaceutical was administered intravenously and tested for its ability to image (at 48-72 h after administration) 31 primary and 85 metastatic carcinoma lesions in 70 adenocarcinoma patients (26 gastrointestinal, 18 breast and 26 lung tumour patients) whose serum CEA was elevated in 43 cases and normal in the other 27. (author)

  2. Experimental study on 211At labelled monoclonal antibody 3H11 and its Fab fragment radioimmunotherapy for human gastric cancer xenografts in nude mice

    International Nuclear Information System (INIS)

    Jin Jiannan; Liu Ning; Zhang Shuyuan; Zhang Shiyuan; Luo Deyuan; Zhou Maolun

    1996-01-01

    Experimental radioimmunotherapy investigation of α-emitting radionuclide 211 At labelled anti-gastric cancer monoclonal antibody 3H11 and its Fab fragment for nude mice carrying human gastric cancer xenografts was conducted. Three i.p. injections of 14.8 or 22.2 kBq/g mouse were given, once every 5 days. The results showed that the growth of tumor xenografts was inhibited efficiently. The most evident therapy effect was observed at 15 days after treatment, and the tumor inhibition rates were 65% and 72%, respectively. No radiation injury of important organs was found

  3. Generation of human antibody fragments recognizing distinct epitopes of the nucleocapsid (N SARS-CoV protein using a phage display approach

    Directory of Open Access Journals (Sweden)

    Grasso Felicia

    2005-09-01

    Full Text Available Abstract Background Severe acute respiratory syndrome (SARS-CoV is a newly emerging virus that causes SARS with high mortality rate in infected people. Successful control of the global SARS epidemic will require rapid and sensitive diagnostic tests to monitor its spread, as well as, the development of vaccines and new antiviral compounds including neutralizing antibodies that effectively prevent or treat this disease. Methods The human synthetic single-chain fragment variable (scFv ETH-2 phage antibody library was used for the isolation of scFvs against the nucleocapsid (N protein of SARS-CoV using a bio panning-based strategy. The selected scFvs were characterized under genetics-molecular aspects and for SARS-CoV N protein detection in ELISA, western blotting and immunocytochemistry. Results Human scFv antibodies to N protein of SARS-CoV can be easily isolated by selecting the ETH-2 phage library on immunotubes coated with antigen. These in vitro selected human scFvs specifically recognize in ELISA and western blotting studies distinct epitopes in N protein domains and detect in immunohistochemistry investigations SARS-CoV particles in infected Vero cells. Conclusion The human scFv antibodies isolated and described in this study represent useful reagents for rapid detection of N SARS-CoV protein and SARS virus particles in infected target cells.

  4. Antibody fragments directed against different portions of the human neural cell adhesion molecule L1 act as inhibitors or activators of L1 function.

    Directory of Open Access Journals (Sweden)

    Yan Wang

    Full Text Available The neural cell adhesion molecule L1 plays important roles in neuronal migration and survival, neuritogenesis and synaptogenesis. L1 has also been found in tumors of different origins, with levels of L1 expression correlating positively with the metastatic potential of tumors. To select antibodies targeting the varied functions of L1, we screened the Tomlinson library of recombinant human antibody fragments to identify antibodies binding to recombinant human L1 protein comprising the entire extracellular domain of human L1. We obtained four L1 binding single-chain variable fragment antibodies (scFvs, named I4, I6, I13, and I27 and showed by enzyme-linked immunosorbent assay (ELISA that scFvs I4 and I6 have high affinity to the immunoglobulin-like (Ig domains 1-4 of L1, while scFvs I13 and I27 bind strongly to the fibronectin type III homologous (Fn domains 1-3 of L1. Application of scFvs I4 and I6 to human SK-N-SH neuroblastoma cells reduced proliferation and transmigration of these cells. Treatment of SK-N-SH cells with scFvs I13 and I27 enhanced cell proliferation and migration, neurite outgrowth, and protected against the toxic effects of H(2O(2 by increasing the ratio of Bcl-2/Bax. In addition, scFvs I4 and I6 inhibited and scFvs I13 and I27 promoted phosphorylation of src and Erk. Our findings indicate that scFvs reacting with the immunoglobulin-like domains 1-4 inhibit L1 functions, whereas scFvs interacting with the fibronectin type III domains 1-3 trigger L1 functions of cultured neuroblastoma cells.

  5. Crystallization and preliminary X-ray diffraction analysis of the Fab fragment of WO2, an antibody specific for the Aβ peptides associated with Alzheimer’s disease

    Energy Technology Data Exchange (ETDEWEB)

    Wun, Kwok S. [Biota Structural Biology Laboratory and Centre for Structural Neurobiology, St Vincent’s Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065 (Australia); Miles, Luke A. [Biota Structural Biology Laboratory and Centre for Structural Neurobiology, St Vincent’s Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065 (Australia); Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010 (Australia); Crespi, Gabriela A. N. [Biota Structural Biology Laboratory and Centre for Structural Neurobiology, St Vincent’s Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065 (Australia); Wycherley, Kaye [WEHI Biotechnology Centre, La Trobe R& D Park, Bundoora, Victoria 3086 (Australia); Ascher, David B. [Biota Structural Biology Laboratory and Centre for Structural Neurobiology, St Vincent’s Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065 (Australia); Barnham, Kevin J.; Cappai, Roberto [Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010 (Australia); Department of Pathology, The University of Melbourne, Victoria 3010 (Australia); The Mental Health Research Institute of Victoria, Parkville, Victoria 3052 (Australia); Beyreuther, Konrad [ZMBH, University of Heidelberg, Heidelberg (Germany); Masters, Colin L. [Department of Pathology, The University of Melbourne, Victoria 3010 (Australia); The Mental Health Research Institute of Victoria, Parkville, Victoria 3052 (Australia); Parker, Michael W. [Biota Structural Biology Laboratory and Centre for Structural Neurobiology, St Vincent’s Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065 (Australia); Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010 (Australia); McKinstry, William J., E-mail: wjmckinstry@hotmail.com [Biota Structural Biology Laboratory and Centre for Structural Neurobiology, St Vincent’s Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065 (Australia); Department of Medicine (St Vincent’s Hospital), The University of Melbourne, 41 Victoria Parade, Fitzroy 3065 (Australia)

    2008-05-01

    Crystallization and X-ray diffraction data collection of the Fab fragment of the monoclonal antibody WO2 in the absence or presence of amyloid β peptides associated with Alzheimer’s disease are reported. The murine monoclonal antibody WO2 specifically binds the N-terminal region of the amyloid β peptide (Aβ) associated with Alzheimer’s disease. This region of Aβ has been shown to be the immunodominant B-cell epitope of the peptide and hence is considered to be a basis for the development of immunotherapeutic strategies against this prevalent cause of dementia. Structural studies have been undertaken in order to characterize the molecular basis for antibody recognition of this important epitope. Here, details of the crystallization and X-ray analysis of the Fab fragment of the unliganded WO2 antibody in two crystal forms and of the complexes that it forms with the truncated Aβ peptides Aβ{sub 1–16} and Aβ{sub 1–28} are presented. These crystals were all obtained using the hanging-drop vapour-diffusion method at 295 K. Crystals of WO2 Fab were grown in polyethylene glycol solutions containing ZnSO{sub 4}; they belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} and diffracted to 1.6 Å resolution. The complexes of WO2 Fab with either Aβ{sub 1–@}@{sub 16} or Aβ{sub 1–28} were cocrystallized from polyethylene glycol solutions. These two complex crystals grew in the same space group, P2{sub 1}2{sub 1}2{sub 1}, and diffracted to 1.6 Å resolution. A second crystal form of WO2 Fab was grown in the presence of the sparingly soluble Aβ{sub 1–42} in PEG 550 MME. This second form belonged to space group P2{sub 1} and diffracted to 1.9 Å resolution.

  6. 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.

  7. An integrated top-down and bottom-up proteomic approach to characterize the antigen-binding fragment of antibodies.

    Science.gov (United States)

    Dekker, Lennard; Wu, Si; Vanduijn, Martijn; Tolić, Nikolai; Stingl, Christoph; Zhao, Rui; Luider, Theo; Paša-Tolić, Ljiljana

    2014-05-01

    We have previously shown that different individuals exposed to the same antigen produce antibodies with identical mutations in their complementarity determining regions (CDR), suggesting that CDR tryptic peptides can serve as biomarkers for disease diagnosis and prognosis. Complete Fabs derived from disease specific antibodies have even higher potential; they could potentially be used for disease treatment and are required to identify the antigens toward which the antibodies are directed. However, complete Fab sequence characterization via LC-MS analysis of tryptic peptides (i.e. bottom-up) has proven to be impractical for mixtures of antibodies. To tackle this challenge, we have developed an integrated bottom-up and top-down MS approach, employing 2D chromatography coupled with Fourier transform mass spectrometry (FTMS), and applied this approach for full characterization of the variable parts of two pharmaceutical monoclonal antibodies with sensitivity comparable to the bottom-up standard. These efforts represent an essential step toward the identification of disease specific antibodies in patient samples with potentially significant clinical impact. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Localization by whole-body autoradiography of intact and fragmented radiolabeled antibodies in a metastatic human colonic cancer model

    International Nuclear Information System (INIS)

    Fand, Irwin; Sharkey, R.M.; Grundy, J.P.; Goldenberg, D.M.

    1992-01-01

    In this report, we have employed macroautoradiography to compare the tumor targeting of 125 I-labeled anti-carcinoembryonic antigen (CEA) MAb (NP-4) to 125 I-labeled anti-colon-specific antigen-p (CSAp) MAb (Mu-9) and their labeled F(ab') 2 and Fab' fragments, in nude mice each bearing large dorsal human colonic tumor xenografts, and small nodular tumors in the liver and lungs. Using intact MAbs (NP-4 and Mu-9), clearance of background radioactivity was delayed to 3-7 days post-treatment. Treatment with F(ab') 2 and Fab' fragments of both NP-4 and Mu-9 MAbs, however, promoted clearance of background 125 I-radioactivity which was well advanced by 6-24 h and complete by 24-48 h after injection. Localization of 125 I-radioactivity in large and micrometastatic tumor perimeters was the most characteristic uptake pattern observed for both intact and fragmented MAbs. Qualitative analysis of macroautoradiographic images and quantitative densitometry indicated that the higher tumor-to-blood ratios achieved with labeled F(ab') 2 and Fab' fragments at early time points, compared to labeled whole immunoglobulin, appeared to be more a function of rapid plasma clearance, tumor mass, location of xenografts and specific tumor growth patterns than increased tumor penetrance by lower molecular weight univalent and bivalent immune fragments. (Author)

  9. An Immunosensor Based on Antibody Binding Fragments Attached to Gold Nanoparticles for the Detection of Peptides Derived from Avian Influenza Hemagglutinin H5

    Directory of Open Access Journals (Sweden)

    Urszula Jarocka

    2014-08-01

    Full Text Available This paper concerns the development of an immunosensor for detection of peptides derived from avian influenza hemagglutinin H5. Its preparation consists of successive gold electrode modification steps: (i modification with 1,6-hexanedithiol and gold colloidal nanoparticles; (ii immobilization of antibody-binding fragments (Fab’ of anti-hemagglutinin H5 monoclonal antibodies Mab 6-9-1 via S-Au covalent bonds; and (iii covering the remaining free space on the electrode surfaces with bovine serum albumin. The interactions between Fab’ fragments and hemagglutinin (HA variants have been explored with electrochemical impedance spectroscopy (EIS in the presence of [Fe(CN6]3−/4− as an electroactive marker. The immunosensor was able to recognize three different His-tagged variants of recombinant hemagglutinin from H5N1 viruses: H1 subunit (17–340 residues of A/swan/Poland/305-135V08/2006, the long HA (17–530 residues A/Bar-headed Goose/Qinghai/12/2005 and H1 subunit (1–345 residues of A/Vietnam/1194/2004. The strongest response has been observed for the long variant with detection limit of 2.2 pg/mL and dynamic range from 4.0 to 20.0 pg/mL.

  10. Repeated embryo collection and interspecies transfer in alpacas and llamas during non-breeding season

    OpenAIRE

    Pacheco J; Tollig S; Von Walter AW; Pezo D; Velez V

    2015-01-01

    Sexual behavior evaluation was evaluated, collecting and interspecies embryo transfer inter species in llamas and alpacas during non-breeding season, 10 and 10 donor alpacas llamas, alpacas and 20 receiving 20 llamas, 5 alpacas and 5 llamas males were used. Sexual behavior by libido in males and acceptance of female to male in the presence of a dominant follicle was evaluated, the collection of embryos simple ovulation by non-surgical technique was performed and the fresh embryos are transfer...

  11. Isolation and characterisation of a human-like antibody fragment (scFv that inactivates VEEV in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Torsten Rülker

    Full Text Available Venezuelan equine encephalitis virus (VEEV belongs to the Alphavirus genus and several species of this family are pathogenic to humans. The viruses are classified as potential agents of biological warfare and terrorism and sensitive detection as well as effective prophylaxis and antiviral therapies are required.In this work, we describe the isolation of the anti-VEEV single chain Fragment variable (scFv, ToR67-3B4, from a non-human primate (NHP antibody gene library. We report its recloning into the bivalent scFv-Fc format and further immunological and biochemical characterisation.The scFv-Fc ToR67-3B4 recognised viable as well as formalin and ß-propionolactone (ß-Pl inactivated virus particles and could be applied for immunoblot analysis of VEEV proteins and immuno-histochemistry of VEEV infected cells. It detected specifically the viral E1 envelope protein of VEEV but did not react with reduced viral glycoprotein preparations suggesting that recognition depends upon conformational epitopes. The recombinant antibody was able to detect multiple VEEV subtypes and displayed only marginal cross-reactivity to other Alphavirus species except for EEEV. In addition, the scFv-Fc fusion described here might be of therapeutic use since it successfully inactivated VEEV in a murine disease model. When the recombinant antibody was administered 6 hours post challenge, 80% to 100% of mice survived lethal VEEV IA/B or IE infection. Forty to sixty percent of mice survived when scFv-Fc ToR67-3B4 was applied 6 hours post challenge with VEEV subtypes II and former IIIA. In combination with E2-neutralising antibodies the NHP antibody isolated here could significantly improve passive protection as well as generic therapy of VEE.

  12. 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.

  13. Metabolic changes and induction of hepatic lipidosis during feed restriction in llamas.

    Science.gov (United States)

    Tornquist, S J; Cebra, C K; Van Saun, R J; Smith, B B; Mattoon, J S

    2001-07-01

    To determine whether feed restriction induces hepatic lipidosis (HL) in llamas and to evaluate the metabolic changes that develop during feed restriction. 8 healthy adult female llamas. Llamas were fed grass hay at a rate of 0.25% of their body weight per day for 13 to 28 days. Llamas were monitored by use of clinical observation, serum biochemical analyses, and ultrasound-guided liver biopsies. All 8 llamas lost weight and mobilized fat. Five llamas developed HL, including 4 that were nursing crias. During the period of feed restriction, mean serum concentration of bile acids and activities of aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), and gamma-glutamyl transferase (GGT) were significantly higher in llamas that developed HL, compared with llamas that did not. Mean insulin-to-cortisol concentration ratios were lower in llamas with HL before and up to 7 days of feed restriction, compared with those that did not develop HL. HL in llamas may be induced by severe feed restriction, particularly in the face of increased energy demand. Llamas with weight loss attributable to inadequate dietary intake may develop biochemical evidence of hepatopathy and HL. Increases in serum concentration of bile acids and activities of GGT, AST, and SDH may indicate the development of HL in llamas and identify affected animals for aggressive therapeutic intervention.

  14. On-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry using Fab´antibody fragments for the analysis of serum transthyretin.

    Science.gov (United States)

    Pont, Laura; Benavente, Fernando; Barbosa, José; Sanz-Nebot, Victoria

    2017-08-01

    This paper describes an on-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry (IA-SPE-CE-MS) method using an immunoaffinity sorbent with Fab' antibody fragments (Fab'-IA) for the analysis of serum transthyretin (TTR), a homotetrameric protein (M r ~56,000) involved in different types of amyloidosis. The IA sorbent was prepared by covalent attachment of Fab' fragments obtained from a polyclonal IgG antibody against TTR to succinimidyl silica particles. The Fab'-IA-SPE-CE-MS methodology was first established analyzing TTR standard solutions. Under optimized conditions, repeatability and reproducibility were acceptable, the method was linear between 1 and 25µgmL -1 , limits of detection (LODs) were around 0.5µgmL -1 (50-fold lower than by CE-MS, ~25µgmL -1 ) and different TTR conformations were observed (folded and unfolded). The applicability of the developed method to screen for familial amyloidotic polyneuropathy type I (FAP-I), which is the most common hereditary systemic amyloidosis, was evaluated analyzing serum samples from healthy controls and FAP-I patients. For the analysis of sera, the most abundant proteins were precipitated with 5% (v/v) of phenol before Fab'-IA-SPE-CE-MS. The current method enhanced our previous results for the analysis of TTR using intact antibodies immobilized on magnetic beads. It allowed a slight improvement on LODs (2-fold), the detection of proteoforms found at lower concentrations and the preparation of microcartridges with extended durability. Copyright © 2017. Published by Elsevier B.V.

  15. 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.

  16. Isolation of scFv antibody fragments against HER2 and CEA tumor antigens from combinatorial antibody libraries derived from cancer patients.

    Science.gov (United States)

    Ayat, Hoda; Burrone, Oscar R; Sadghizadeh, Majid; Jahanzad, Eissa; Rastgou, Nasrin; Moghadasi, Sarrira; Arbabi, Mehdi

    2013-11-01

    Tumor cells expressing HER-2/neu and CEA antigens are potentially ideal targets for antibody-targeted therapy. In this study, two large human combinatorial libraries have been generated from the lymph nodes of breast cancer patients that express HER2 and CEA antigens in their tumors. These 'immune' libraries have been constructed in two different formats of scFv, differing in the length of the peptide linker connecting the two variable VH and VL domains. Libraries derived from these patients may contain a larger pool of anti-tumor antigen antibodies and are useful repertoire for isolating scFvs against any tumor markers. The results of this study showed that we were successful in obtaining human scFvs against HER-2/neu and CEA. For HER-2, cell-panning strategy was performed and resulted in two scFv binders that detected the complete HER-2 receptor on the cell membrane and internalized to the cells. Also, preliminary ELISA data showed that several anti-CEA scFv binders were isolated by panning. Copyright © 2013 The International Alliance for Biological Standardization. All rights reserved.

  17. Computed tomography of the llama head: technique and normal anatomy

    International Nuclear Information System (INIS)

    Hathcock, J.T.; Pugh, D.G.; Cartee, R.E.; Hammond, L.

    1996-01-01

    Computed tomography was performed on the head of 6 normal adult llamas. The animals were under general anesthesia and positioned in dorsal recumbency on the scanning table. The area scanned was from the external occipital protuberance to the rostral portion of the nasal passage, and the images are presented in both a bone window and a soft tissue window to allow evaluation and identification of the anatomy of the head. Computed tomography of the llama head can be accomplished by most computed tomography scanners utilizing a technique similar to that used in small animals with minor modification of the scanning table

  18. 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.

  19. Construction of a llama bacterial artificial chromosome library with approximately 9-fold genome equivalent coverage.

    Science.gov (United States)

    Airmet, K W; Hinckley, J D; Tree, L T; Moss, M; Blumell, S; Ulicny, K; Gustafson, A K; Weed, M; Theodosis, R; Lehnardt, M; Genho, J; Stevens, M R; Kooyman, D L

    2012-01-01

    The Ilama is an important agricultural livestock in much of South America. The llama is increasing in popularity in the United States as a companion animal. Little work has been done to improve llama production using modern technology. A paucity of information is available regarding the llama genome. We report the construction of a llama bacterial artificial chromosome (BAC) library of about 196,224 clones in the vector pECBAC1. Using flow cytometry and bovine, human, mouse, and chicken as controls, we determined the llama genome size to be 2.4 × 10⁹ bp. The average insert size of the library is 137.8 kb corresponding to approximately 9-fold genome coverage. Further studies are needed to further characterize the library and llama genome. We anticipate that this new library will help facilitate future genomic studies in the llama.

  20. Crystallization and preliminary X-ray diffraction analysis of prion protein bound to the Fab fragment of the POM1 antibody

    International Nuclear Information System (INIS)

    Baral, Pravas Kumar; Wieland, Barbara; Swayampakula, Mridula; Polymenidou, Magdalini; Aguzzi, Adriano; Kav, Nat N. V.; James, Michael N. G.

    2011-01-01

    The complex of MoPrP(120–232) and Fab POM1 has been crystallized (space group C2, unit-cell parameters a = 83.68, b = 106.9, c = 76.25 Å, β = 95.6°). Diffraction data to 2.30 Å resolution have been collected using synchrotron radiation. Prion diseases are neurodegenerative diseases that are characterized by the conversion of the cellular prion protein PrP c to the pathogenic isoform PrP sc . Several antibodies are known to interact with the cellular prion protein and to inhibit this transition. An antibody Fab fragment, Fab POM1, was produced that recognizes a structural motif of the C-terminal domain of mouse prion protein. To study the mechanism by which Fab POM1 recognizes and binds the prion molecule, the complex between Fab POM1 and the C-terminal domain of mouse prion (residues 120–232) was prepared and crystallized. Crystals of this binary complex belonged to the monoclinic space group C2, with unit-cell parameters a = 83.68, b = 106.9, c = 76.25 Å, β = 95.6°

  1. Mapping the Binding Interface of VEGF and a Monoclonal Antibody Fab-1 Fragment with Fast Photochemical Oxidation of Proteins (FPOP) and Mass Spectrometry

    Science.gov (United States)

    Zhang, Ying; Wecksler, Aaron T.; Molina, Patricia; Deperalta, Galahad; Gross, Michael L.

    2017-05-01

    We previously analyzed the Fab-1:VEGF (vascular endothelial growth factor) system described in this work, with both native top-down mass spectrometry and bottom-up mass spectrometry (carboxyl-group or GEE footprinting) techniques. This work continues bottom-up mass spectrometry analysis using a fast photochemical oxidation of proteins (FPOP) platform to map the solution binding interface of VEGF and a fragment antigen binding region of an antibody (Fab-1). In this study, we use FPOP to compare the changes in solvent accessibility by quantitating the extent of oxidative modification in the unbound versus bound states. Determining the changes in solvent accessibility enables the inference of the protein binding sites (epitope and paratopes) and a comparison to the previously published Fab-1:VEGF crystal structure, adding to the top-down and bottom-up data. Using this method, we investigated peptide-level and residue-level changes in solvent accessibility between the unbound proteins and bound complex. Mapping these data onto the Fab-1:VEGF crystal structure enabled successful characterization of both the binding region and regions of remote conformation changes. These data, coupled with our previous higher order structure (HOS) studies, demonstrate the value of a comprehensive toolbox of methods for identifying the putative epitopes and paratopes for biotherapeutic antibodies.

  2. 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

  3. Pharmacokinetics of the FO23C5 anti-CEA antibody fragment labelled with 99Tcm and 111In: a comparison in patients

    International Nuclear Information System (INIS)

    Hnatowich, D.J.; Mardirossian, G.; Rusckowski, M.; Roy, S.; Busche, H.; Griffin, T.W.; Brill, A.B.

    1993-01-01

    The FO23C5 anti-carcinoembryonic antigen (CEA) F(ab') 2 antibody was radiolabelled with sup(111)In via diethylenetriaminepentaacetic acid (DTPA) and directly with 99 Tc m by stannous ion and mercaptoethanol antibody reduction to compare the pharmacokinetics of these three agents. Four patients received 15 mCi 99 Tc m -Fab' 1 week before receiving 1 mCi 111 In-F(ab') 2 . Five additional patients received only the 99 Tc m -Fab'. The biodistribution of 99 Tc m was as expected for a labelled Fab' fragment: relative to 111 In, 99 Tc m cleared rapidly from circulation and into kidneys and urine. Liver levels of 111 In and 99 Tc m were surprisingly similar at 1 day although initial 111 In levels were lower and increased while 99 Tc m levels were higher and decreased. Spleen levels were also similar. In 4/9 patients receiving 99 Tc m , hepatobiliary clearance was observed at levels which could confuse interpretation whereas this mode of clearance was observed in only 1/4 patients receiving 111 In. Image quality was superior with 111 In versus 99 Tc m at 1 day postadministration as judged by counting rates and background activity whereas the opposite was true at 2-3 h postadministration. (author)

  4. Multinuclear NMR study of the structure of the Fv fragment of anti-dansyl mouse IgG2a antibody

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hideo; Odaka, Asano; Matsunaga, Chigusa; Kato, Koichi; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo (Japan)); Kawaminami, Shunro (Kao Corp., Tochigi (Japan))

    1991-07-02

    A multinuclear NMR study is reported of Fv, which is a minimum antigen-binding unit of immunoglobulin. Fv has been prepared by clostripain digestion of a mouse anti-dansyl IgG2a monoclonal antibody that lacks the entire C{sub H}1 domain. A variety of Fv analogues labeled with {sup 2}H in the aromatic rings and with {sup 13}C and/or {sup 15}N in the peptide bonds have been prepared and used for multinuclear NMR analyses of Fv spectra of Fv sensitively reflect the antigen binding and can be used along with {sup 1}H and {sup 13}C spectral data for the structural analyses of antigen-antibody interactions. Hydrogen-deuterium exchange of the amide protons has been folowed in the absence and presence of DNS-Lys by using the {sup 1}H-{sup 15}N shift correlation spectra. Use of the {beta}-shift observed for the carbonyl carbon resonances has also been helpful in following the hydrogen-deuterium exchange. On the basis of the NMR data obtained, the static and dynamic structure of the Fv fragment in the absence and presence of DNS-Lys has been discussed.

  5. Multinuclear NMR study of the structure of the Fv fragment of anti-dansyl mouse IgG2a antibody

    International Nuclear Information System (INIS)

    Takahashi, Hideo; Odaka, Asano; Matsunaga, Chigusa; Kato, Koichi; Shimada, Ichio; Arata, Yoji; Kawaminami, Shunro

    1991-01-01

    A multinuclear NMR study is reported of Fv, which is a minimum antigen-binding unit of immunoglobulin. Fv has been prepared by clostripain digestion of a mouse anti-dansyl IgG2a monoclonal antibody that lacks the entire C H 1 domain. A variety of Fv analogues labeled with 2 H in the aromatic rings and with 13 C and/or 15 N in the peptide bonds have been prepared and used for multinuclear NMR analyses of Fv spectra of Fv sensitively reflect the antigen binding and can be used along with 1 H and 13 C spectral data for the structural analyses of antigen-antibody interactions. Hydrogen-deuterium exchange of the amide protons has been folowed in the absence and presence of DNS-Lys by using the 1 H- 15 N shift correlation spectra. Use of the β-shift observed for the carbonyl carbon resonances has also been helpful in following the hydrogen-deuterium exchange. On the basis of the NMR data obtained, the static and dynamic structure of the Fv fragment in the absence and presence of DNS-Lys has been discussed

  6. Generalized Tuberculosis in Llamas (Lama glama) Due to Mycobacterium microti

    Science.gov (United States)

    Oevermann, A.; Pfyffer, G. E.; Zanolari, P.; Meylan, M.; Robert, N.

    2004-01-01

    Necropsy of two llamas revealed numerous caseous nodules containing abundant acid-fast bacilli (AFB) in various organs. The AFB were identified by spoligotyping as Mycobacterium microti, vole type. Infection caused by M. microti should be considered in the differential diagnosis of debilitating diseases in New World camelids. PMID:15071059

  7. Peritonitis in a llama caused by Streptococcus equi subsp. zooepidemicus.

    Science.gov (United States)

    Hewson, J; Cebra, C K

    2001-01-01

    A 7-month-old, male llama was diagnosed with peritonitis caused by Streptococcus equi subsp. zooepidemicus. Clinical findings, medical treatment, and case outcome are described. Hematogenous dissemination from suspected pneumonia is proposed as the route of infection in this case. Possible transmission of the organism through contact with horses is discussed. PMID:11424579

  8. Comparing manager and visitor perceptions of llama use in wilderness

    Science.gov (United States)

    Alan E. Watson; Neal A. Christensen; Dale J. Blahna; Kari S. Archibald

    1998-01-01

    Llama use in wilderness is projected to increase over the next 5 years. While the greatest concerns about this increase in use are unexpected impacts to native flora, impacts to native fauna, and conflicts with other user types, there is also concern about how prepared managers are to deal with this increasing recreation demand. This research compares manager attitudes...

  9. A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

    International Nuclear Information System (INIS)

    Qi, Zhi; Pan, Chungen; Lu, Hong; Shui, Yuan; Li, Lin; Li, Xiaojuan; Xu, Xueqing; Liu, Shuwen; Jiang, Shibo

    2010-01-01

    Research highlights: → One recombinant mimetics of gp41 prehairpin fusion intermediate (PFI) consisting of gp41 N46 sequence, foldon and IgG Fc, designated N46FdFc, was expressed. → N46FdFc-induced antibodies in mice that neutralized HIV-1 infection, inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. → These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines. -- Abstract: HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.

  10. Neuromuscular partitioning, architectural design, and myosin fiber types of the M. vastus lateralis of the llama (Lama glama).

    Science.gov (United States)

    Graziotti, Guillermo H; Palencia, Pablo; Delhon, Gustavo; Rivero, José-Luis L

    2004-11-01

    The llama (Lama glama) is one of the few mammals of relatively large body size in which three fast myosin heavy chain isoforms (i.e., IIA, IIX, IIB) are extensively expressed in their locomotory muscles. This study was designed to gain insight into the morphological and functional organization of skeletal musculature in this peculiar animal model. The neuromuscular partitioning, architectural design, and myosin fiber types were systematically studied in the M. vastus lateralis of adult llamas (n = 15). Four nonoverlapping neuromuscular partitions or compartments were identified macroscopically (using a modified Sihler's technique for muscle depigmentation), although they did not conform strictly to the definitions of "neuromuscular compartments." Each neuromuscular partition was innervated by primary branches of the femoral nerve and was arranged within the muscle as paired partitions, two in parallel (deep-superficial compartmentalization) and the other two in-series (proximo-distal compartmentalization). These neuromuscular partitions of the muscle varied in their respective architectural designs (studied after partial digestion with diluted nitric acid) and myosin fiber type characteristics (identified immunohistochemically with specific anti-myosin monoclonal antibodies, then examined by quantitative histochemistry and image analysis). The deep partitions of the muscle had longer fibers, with lower angles of pinnation, and higher percentages of fast-glycolytic fibers than the superficial partitions of the muscle. These differences clearly suggest a division of labor in the whole M. vastus lateralis of llamas, with deep partitions exhibiting features well adapted for dynamic activities in the extension of stifle, whereas superficial portions seem to be related to the antigravitational role of the muscle in preserving the extension of the stifle during standing and stance phase of the stride. This peculiar structural and functional organization of the llama M

  11. Novel camelid antibody fragments targeting recombinant nucleoprotein of Araucaria hantavirus: a prototype for an early diagnosis of Hantavirus Pulmonary Syndrome.

    Directory of Open Access Journals (Sweden)

    Soraya S Pereira

    Full Text Available In addition to conventional antibodies, camelids produce immunoglobulins G composed exclusively of heavy chains in which the antigen binding site is formed only by single domains called VHH. Their particular characteristics make VHHs interesting tools for drug-delivery, passive immunotherapy and high-throughput diagnosis. Hantaviruses are rodent-borne viruses of the Bunyaviridae family. Two clinical forms of the infection are known. Hemorrhagic Fever with Renal Syndrome (HFRS is present in the Old World, while Hantavirus Pulmonary Syndrome (HPS is found on the American continent. There is no specific treatment for HPS and its diagnosis is carried out by molecular or serological techniques, using mainly monoclonal antibodies or hantavirus nucleoprotein (N to detect IgM and IgG in patient serum. This study proposes the use of camelid VHHs to develop alternative methods for diagnosing and confirming HPS. Phage display technology was employed to obtain VHHs. After immunizing one Lama glama against the recombinant N protein (prNΔ₈₅ of a Brazilian hantavirus strain, VHH regions were isolated to construct an immune library. VHHs were displayed fused to the M13KO7 phage coat protein III and the selection steps were performed on immobilized prNΔ₈₅. After selection, eighty clones recognized specifically the N protein. These were sequenced, grouped based mainly on the CDRs, and five clones were analyzed by western blot (WB, surface plasmon resonance (SPR device, and ELISA. Besides the ability to recognize prNΔ85 by WB, all selected clones showed affinity constants in the nanomolar range. Additionaly, the clone KC329705 is able to detect prNΔ₈₅ in solution, as well as the native viral antigen. Findings support the hypothesis that selected VHHs could be a powerful tool in the development of rapid and accurate HPS diagnostic assays, which are essential to provide supportive care to patients and reduce the high mortality rate associated with

  12. Analysis of genetic diversity in Bolivian llama populations using microsatellites.

    Science.gov (United States)

    Barreta, J; Gutiérrez-Gil, B; Iñiguez, V; Romero, F; Saavedra, V; Chiri, R; Rodríguez, T; Arranz, J J

    2013-08-01

    South American camelids (SACs) have a major role in the maintenance and potential future of rural Andean human populations. More than 60% of the 3.7 million llamas living worldwide are found in Bolivia. Due to the lack of studies focusing on genetic diversity in Bolivian llamas, this analysis investigates both the genetic diversity and structure of 12 regional groups of llamas that span the greater part of the range of distribution for this species in Bolivia. The analysis of 42 microsatellite markers in the considered regional groups showed that, in general, there were high levels of polymorphism (a total of 506 detected alleles; average PIC across per marker: 0.66), which are comparable with those reported for other populations of domestic SACs. The estimated diversity parameters indicated that there was high intrapopulational genetic variation (average number of alleles and average expected heterozygosity per marker: 12.04 and 0.68, respectively) and weak genetic differentiation among populations (FST range: 0.003-0.052). In agreement with these estimates, Bolivian llamas showed a weak genetic structure and an intense gene flow between all the studied regional groups, which is due to the exchange of reproductive males between the different flocks. Interestingly, the groups for which the largest pairwise FST estimates were observed, Sud Lípez and Nor Lípez, showed a certain level of genetic differentiation that is probably due to the pattern of geographic isolation and limited communication infrastructures of these southern localities. Overall, the population parameters reported here may serve as a reference when establishing conservation policies that address Bolivian llama populations. © 2012 Blackwell Verlag GmbH.

  13. Combining proteomic tools to characterize the protein fraction of llama (Lama glama) milk.

    Science.gov (United States)

    Saadaoui, Besma; Bianchi, Leonardo; Henry, Céline; Miranda, Guy; Martin, Patrice; Cebo, Christelle

    2014-05-01

    Llamas belong to the Camelidae family along with camels. While dromedary camel milk has been broadly characterized, data on llama milk proteins are scarce. The objective of this study was thus to investigate the protein composition of llama milk. Skimmed llama milk proteins were first characterized by a 2D separation technique coupling RP-HPLC in the first dimension with SDS-PAGE in the second dimension (RP-HPLC/SDS-PAGE). Llama milk proteins, namely caseins (αs1 -, αs2 -, β-, and κ-caseins), α-lactalbumin, lactoferrin, and serum albumin, were identified using PMF. Llama milk proteins were also characterized by online LC-ESI-MS analysis. This approach allowed attributing precise molecular masses for most of the previously MS-identified llama milk proteins. Interestingly, α-lactalbumin exhibits distinct chromatographic behaviors between llama and dromedary camel milk. De novo sequencing of the llama α-lactalbumin protein by LC coupled with MS/MS (LC-MS/MS) showed the occurrence of two amino acid substitutions (R62L/I and K89L/I) that partly explained the higher hydrophobicity of llama α-lactalbumin compared with its dromedary counterpart. Taken together, these results provide for the first time a thorough description of the protein fraction of Lama glama milk. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. ImmunoPET of tissue factor expression in triple-negative breast cancer with a radiolabeled antibody Fab fragment

    International Nuclear Information System (INIS)

    Shi, Sixiang; Hong, Hao; Orbay, Hakan; Yang, Yunan; Ohman, Jakob D.; Graves, Stephen A.; Nickles, Robert J.; Liu, Bai; Wong, Hing C.; Cai, Weibo

    2015-01-01

    To date, there is no effective therapy for triple-negative breast cancer (TNBC), which has a dismal clinical outcome. Upregulation of tissue factor (TF) expression leads to increased patient morbidity and mortality in many solid tumor types, including TNBC. Our goal was to employ the Fab fragment of ALT-836, a chimeric anti-human TF mAb, for PET imaging of TNBC, which can be used to guide future TNBC therapy. ALT-836-Fab was generated by enzymatic papain digestion. SDS-PAGE and FACS studies were performed to evaluate the integrity and TF binding affinity of ALT-836-Fab before NOTA conjugation and 64 Cu-labeling. Serial PET imaging and biodistribution studies were carried out to evaluate the tumor targeting efficacy and pharmacokinetics in the MDA-MB-231 TNBC model, which expresses high levels of TF on the tumor cells. Blocking studies, histological assessment, as well as RT-PCR were performed to confirm TF specificity of 64 Cu-NOTA-ALT-836-Fab. ALT-836-Fab was produced with high purity, which exhibited superb TF binding affinity and specificity. Serial PET imaging revealed rapid and persistent tumor uptake of 64 Cu-NOTA-ALT-836-Fab (5.1 ± 0.5 %ID/g at 24 h post-injection; n = 4) and high tumor/muscle ratio (7.0 ± 1.2 at 24 h post-injection; n = 4), several-fold higher than that of the blocking group and tumor models that do not express significant level of TF, which was confirmed by biodistribution studies. TF specificity of the tracer was also validated by histology and RT-PCR. 64 Cu-NOTA-ALT-836-Fab exhibited prominent tissue factor targeting efficiency in MDA-MB-231 TNBC model. The use of a Fab fragment led to fast tumor uptake and good tissue/muscle ratio, which may be translated into same-day immunoPET imaging in the clinical setting to improve TNBC patient management. (orig.)

  15. ImmunoPET of tissue factor expression in triple-negative breast cancer with a radiolabeled antibody Fab fragment.

    Science.gov (United States)

    Shi, Sixiang; Hong, Hao; Orbay, Hakan; Graves, Stephen A; Yang, Yunan; Ohman, Jakob D; Liu, Bai; Nickles, Robert J; Wong, Hing C; Cai, Weibo

    2015-07-01

    To date, there is no effective therapy for triple-negative breast cancer (TNBC), which has a dismal clinical outcome. Upregulation of tissue factor (TF) expression leads to increased patient morbidity and mortality in many solid tumor types, including TNBC. Our goal was to employ the Fab fragment of ALT-836, a chimeric anti-human TF mAb, for PET imaging of TNBC, which can be used to guide future TNBC therapy. ALT-836-Fab was generated by enzymatic papain digestion. SDS-PAGE and FACS studies were performed to evaluate the integrity and TF binding affinity of ALT-836-Fab before NOTA conjugation and (64)Cu-labeling. Serial PET imaging and biodistribution studies were carried out to evaluate the tumor targeting efficacy and pharmacokinetics in the MDA-MB-231 TNBC model, which expresses high levels of TF on the tumor cells. Blocking studies, histological assessment, as well as RT-PCR were performed to confirm TF specificity of (64)Cu-NOTA-ALT-836-Fab. ALT-836-Fab was produced with high purity, which exhibited superb TF binding affinity and specificity. Serial PET imaging revealed rapid and persistent tumor uptake of (64)Cu-NOTA-ALT-836-Fab (5.1 ± 0.5 %ID/g at 24 h post-injection; n = 4) and high tumor/muscle ratio (7.0 ± 1.2 at 24 h post-injection; n = 4), several-fold higher than that of the blocking group and tumor models that do not express significant level of TF, which was confirmed by biodistribution studies. TF specificity of the tracer was also validated by histology and RT-PCR. (64)Cu-NOTA-ALT-836-Fab exhibited prominent tissue factor targeting efficiency in MDA-MB-231 TNBC model. The use of a Fab fragment led to fast tumor uptake and good tissue/muscle ratio, which may be translated into same-day immunoPET imaging in the clinical setting to improve TNBC patient management.

  16. ImmunoPET of tissue factor expression in triple-negative breast cancer with a radiolabeled antibody Fab fragment

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Sixiang [University of Wisconsin, Materials Science Program, Madison, WI (United States); Hong, Hao; Orbay, Hakan; Yang, Yunan; Ohman, Jakob D. [University of Wisconsin, Department of Radiology, Madison, WI (United States); Graves, Stephen A.; Nickles, Robert J. [University of Wisconsin, Department of Medical Physics, Madison, WI (United States); Liu, Bai; Wong, Hing C. [Altor BioScience, Miramar, FL (United States); Cai, Weibo [University of Wisconsin, Materials Science Program, Madison, WI (United States); University of Wisconsin, Department of Radiology, Madison, WI (United States); University of Wisconsin, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States); University of Wisconsin, Departments of Radiology and Medical Physics, Madison, WI (United States)

    2015-07-15

    To date, there is no effective therapy for triple-negative breast cancer (TNBC), which has a dismal clinical outcome. Upregulation of tissue factor (TF) expression leads to increased patient morbidity and mortality in many solid tumor types, including TNBC. Our goal was to employ the Fab fragment of ALT-836, a chimeric anti-human TF mAb, for PET imaging of TNBC, which can be used to guide future TNBC therapy. ALT-836-Fab was generated by enzymatic papain digestion. SDS-PAGE and FACS studies were performed to evaluate the integrity and TF binding affinity of ALT-836-Fab before NOTA conjugation and {sup 64}Cu-labeling. Serial PET imaging and biodistribution studies were carried out to evaluate the tumor targeting efficacy and pharmacokinetics in the MDA-MB-231 TNBC model, which expresses high levels of TF on the tumor cells. Blocking studies, histological assessment, as well as RT-PCR were performed to confirm TF specificity of {sup 64}Cu-NOTA-ALT-836-Fab. ALT-836-Fab was produced with high purity, which exhibited superb TF binding affinity and specificity. Serial PET imaging revealed rapid and persistent tumor uptake of {sup 64}Cu-NOTA-ALT-836-Fab (5.1 ± 0.5 %ID/g at 24 h post-injection; n = 4) and high tumor/muscle ratio (7.0 ± 1.2 at 24 h post-injection; n = 4), several-fold higher than that of the blocking group and tumor models that do not express significant level of TF, which was confirmed by biodistribution studies. TF specificity of the tracer was also validated by histology and RT-PCR. {sup 64}Cu-NOTA-ALT-836-Fab exhibited prominent tissue factor targeting efficiency in MDA-MB-231 TNBC model. The use of a Fab fragment led to fast tumor uptake and good tissue/muscle ratio, which may be translated into same-day immunoPET imaging in the clinical setting to improve TNBC patient management. (orig.)

  17. Selection and characterization of naturally occurring single-domain (IgNAR) antibody fragments from immunized sharks by phage display.

    Science.gov (United States)

    Dooley, Helen; Flajnik, Martin F; Porter, Andrew J

    2003-09-01

    The novel immunoglobulin isotype novel antigen receptor (IgNAR) is found in cartilaginous fish and is composed of a heavy-chain homodimer that does not associate with light chains. The variable regions of IgNAR function as independent domains similar to those found in the heavy-chain immunoglobulins of Camelids. Here, we describe the successful cloning and generation of a phage-displayed, single-domain library based upon the variable domain of IgNAR. Selection of such a library generated from nurse sharks (Ginglymostoma cirratum) immunized with the model antigen hen egg-white lysozyme (HEL) enabled the successful isolation of intact antigen-specific binders matured in vivo. The selected variable domains were shown to be functionally expressed in Escherichia coli, extremely stable, and bind to antigen specifically with an affinity in the nanomolar range. This approach can therefore be considered as an alternative route for the isolation of minimal antigen-binding fragments with favorable characteristics.

  18. A Camelid-derived Antibody Fragment Targeting the Active Site of a Serine Protease Balances between Inhibitor and Substrate Behavior.

    Science.gov (United States)

    Kromann-Hansen, Tobias; Oldenburg, Emil; Yung, Kristen Wing Yu; Ghassabeh, Gholamreza H; Muyldermans, Serge; Declerck, Paul J; Huang, Mingdong; Andreasen, Peter A; Ngo, Jacky Chi Ki

    2016-07-15

    A peptide segment that binds the active site of a serine protease in a substrate-like manner may behave like an inhibitor or a substrate. However, there is sparse information on which factors determine the behavior a particular peptide segment will exhibit. Here, we describe the first x-ray crystal structure of a nanobody in complex with a serine protease. The nanobody displays a new type of interaction between an antibody and a serine protease as it inserts its complementary determining region-H3 loop into the active site of the protease in a substrate-like manner. The unique binding mechanism causes the nanobody to behave as a strong inhibitor as well as a poor substrate. Intriguingly, its substrate behavior is incomplete, as 30-40% of the nanobody remained intact and inhibitory after prolonged incubation with the protease. Biochemical analysis reveals that an intra-loop interaction network within the complementary determining region-H3 of the nanobody balances its inhibitor versus substrate behavior. Collectively, our results unveil molecular factors, which may be a general mechanism to determine the substrate versus inhibitor behavior of other protease inhibitors. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. A Camelid-derived Antibody Fragment Targeting the Active Site of a Serine Protease Balances between Inhibitor and Substrate Behavior*

    Science.gov (United States)

    Kromann-Hansen, Tobias; Oldenburg, Emil; Yung, Kristen Wing Yu; Ghassabeh, Gholamreza H.; Muyldermans, Serge; Declerck, Paul J.; Huang, Mingdong; Andreasen, Peter A.; Ngo, Jacky Chi Ki

    2016-01-01

    A peptide segment that binds the active site of a serine protease in a substrate-like manner may behave like an inhibitor or a substrate. However, there is sparse information on which factors determine the behavior a particular peptide segment will exhibit. Here, we describe the first x-ray crystal structure of a nanobody in complex with a serine protease. The nanobody displays a new type of interaction between an antibody and a serine protease as it inserts its complementary determining region-H3 loop into the active site of the protease in a substrate-like manner. The unique binding mechanism causes the nanobody to behave as a strong inhibitor as well as a poor substrate. Intriguingly, its substrate behavior is incomplete, as 30–40% of the nanobody remained intact and inhibitory after prolonged incubation with the protease. Biochemical analysis reveals that an intra-loop interaction network within the complementary determining region-H3 of the nanobody balances its inhibitor versus substrate behavior. Collectively, our results unveil molecular factors, which may be a general mechanism to determine the substrate versus inhibitor behavior of other protease inhibitors. PMID:27226628

  20. Re-188 labelling of DD-3B6/22 Fab' monoclonal antibody fragment for radio immuno therapy

    International Nuclear Information System (INIS)

    Schmidt, P.F.; Smith, S.V.; Bundesen, P.

    1996-01-01

    The chemical similarity of technetium and rhenium has created much interest in the nuclear medicine field to make a 'matched pair' of radiopharmaceuticals for radioimmuno- diagnosis and therapy. Clinical trials with the 99 mTc-DD-3B6/22 Fab' has shown promise in the diagnosis of ovarian cancer. The design of the analogous therapeutic agent with rhenium-188 (155 keV γ 15 % abundant, β E max 2.1 MeV, T 1/2 17 h) is under investigation. The present study describes the approach taken for direct radiolabelling of the DD-3B6/22 Fab' with carrier-free 188 Re and its biological evaluation in balb/c and nude mice. The effect of temperature, pH and antibody concentration on the amount and rate of transchelation was also evaluated. The final product had a specific activity of 35 mCi/mg with an immunoreactive fraction of 77%. Stability of the product was assessed under various conditions: temperature, presence and absence of an inert atmosphere and presence of ascorbic acid (stabilised). Pharmacokinetics of the final product was evaluated in balb/c and nude mice transplanted with both D-dimer (+Ve) and Glycine (-Ve) beads. Results show that 188 Re DD-3B6/22 Fab' clears rapidly from the blood (α = 2.4 hr, β = 3.5 hr) and is excreted through the renal system. Localisation to subcutaneous antigen beads shows specific uptake to the D-dimer (antigen) beads was achieved within 6 h (0.23% ID) and was maintained for 24 hour post injection. Specificity to antigen implants was 5:1 (P 99m Tc DD-3B6/22 Fab' in mice. The radiolabelling procedures are congenial for therapeutic levels and hence the authors believe that the 188 Re DD-3B6/22 Fab' has some potential for use in treatment of ovarian cancer

  1. Double mutation of cell wall proteins CspB and PBP1a increases secretion of the antibody Fab fragment from Corynebacterium glutamicum

    Science.gov (United States)

    2014-01-01

    Background Among other advantages, recombinant antibody-binding fragments (Fabs) hold great clinical and commercial potential, owing to their efficient tissue penetration compared to that of full-length IgGs. Although production of recombinant Fab using microbial expression systems has been reported, yields of active Fab have not been satisfactory. We recently developed the Corynebacterium glutamicum protein expression system (CORYNEX®) and demonstrated improved yield and purity for some applications, although the system has not been applied to Fab production. Results The Fab fragment of human anti-HER2 was successfully secreted by the CORYNEX® system using the conventional C. glutamicum strain YDK010, but the productivity was very low. To improve the secretion efficiency, we investigated the effects of deleting cell wall-related genes. Fab secretion was increased 5.2 times by deletion of pbp1a, encoding one of the penicillin-binding proteins (PBP1a), mediating cell wall peptidoglycan (PG) synthesis. However, this Δpbp1a mutation did not improve Fab secretion in the wild-type ATCC13869 strain. Because YDK010 carries a mutation in the cspB gene encoding a surface (S)-layer protein, we evaluated the effect of ΔcspB mutation on Fab secretion from ATCC13869. The Δpbp1a mutation showed a positive effect on Fab secretion only in combination with the ΔcspB mutation. The ΔcspBΔpbp1a double mutant showed much greater sensitivity to lysozyme than either single mutant or the wild-type strain, suggesting that these mutations reduced cell wall resistance to protein secretion. Conclusion There are at least two crucial permeability barriers to Fab secretion in the cell surface structure of C. glutamicum, the PG layer, and the S-layer. The ΔcspBΔpbp1a double mutant allows efficient Fab production using the CORYNEX® system. PMID:24731213

  2. Effect of culture medium, host strain and oxygen transfer on recombinant Fab antibody fragment yield and leakage to medium in shaken E. coli cultures

    Science.gov (United States)

    2013-01-01

    Background Fab antibody fragments in E. coli are usually directed to the oxidizing periplasmic space for correct folding. From periplasm Fab fragments may further leak into extracellular medium. Information on the cultivation parameters affecting this leakage is scarce, and the unpredictable nature of Fab leakage is problematic regarding consistent product recovery. To elucidate the effects of cultivation conditions, we investigated Fab expression and accumulation into either periplasm or medium in E. coli K-12 and E. coli BL21 when grown in different types of media and under different aeration conditions. Results Small-scale Fab expression demonstrated significant differences in yield and ratio of periplasmic to extracellular Fab between different culture media and host strains. Expression in a medium with fed-batch-like glucose feeding provided highest total and extracellular yields in both strains. Unexpectedly, cultivation in baffled shake flasks at 150 rpm shaking speed resulted in higher yield and accumulation of Fabs into culture medium as compared to cultivation at 250 rpm. In the fed-batch medium, extracellular fraction in E. coli K-12 increased from 2-17% of total Fab at 250 rpm up to 75% at 150 rpm. This was partly due to increased lysis, but also leakage from intact cells increased at the lower shaking speed. Total Fab yield in E. coli BL21 in glycerol-based autoinduction medium was 5 to 9-fold higher at the lower shaking speed, and the extracellular fraction increased from ≤ 10% to 20-90%. The effect of aeration on Fab localization was reproduced in multiwell plate by variation of culture volume. Conclusions Yield and leakage of Fab fragments are dependent on expression strain, culture medium, aeration rate, and the combination of these parameters. Maximum productivity in fed-batch-like conditions and in autoinduction medium is achieved under sufficiently oxygen-limited conditions, and lower aeration also promotes increased Fab accumulation into

  3. Repeated embryo collection and interspecies transfer in alpacas and llamas during non-breeding season

    Directory of Open Access Journals (Sweden)

    Pacheco J

    2015-08-01

    Full Text Available Sexual behavior evaluation was evaluated, collecting and interspecies embryo transfer inter species in llamas and alpacas during non-breeding season, 10 and 10 donor alpacas llamas, alpacas and 20 receiving 20 llamas, 5 alpacas and 5 llamas males were used. Sexual behavior by libido in males and acceptance of female to male in the presence of a dominant follicle was evaluated, the collection of embryos simple ovulation by non-surgical technique was performed and the fresh embryos are transferred directly into the horn left. It was observed that only 40% of alpaca accept the male and female in all cases had to use two males for mating, but all llama males mounted on the first attempt and accepted all females breeding. Embryos were collected at 25 and 60% of alpacas and llamas washes respectively, all were grade 1 embryos transferable; the embryo transfer fertility evaluated by ultrasound at 25 days was 100 and 41.6% respectively for donor alpaca and llama, however ultrasound evaluation at 60 days fertility was 50 and 25% respectively for donor alpaca and llama. We conclude that there is greater reproductive seasonality in alpaca regard to llamas, all were grade 1 embryos collected, fertility evaluated by ultrasound 25 days down to 60 days, demonstrating embryonic mortality, possibly due to the non-breeding season of both species.

  4. No detectable carotenoid concentrations in serum of llamas and alpacas.

    Science.gov (United States)

    Raila, J; Schweigert, F J; Stanitznig, A; Lambacher, B; Franz, S; Baldermann, S; Wittek, T

    2017-08-01

    Carotenoids are lipid-soluble pigments and important for a variety of physiological functions. They are major dietary vitamin A precursors and act as lipophilic antioxidants in a variety of tissues and are associated with important health benefits in humans and animals. All animals must acquire carotenoids from their diet, but to our knowledge, there are no studies investigating the intestinal carotenoid absorption and their blood concentrations in New World camelids. The present study aimed to assess the serum concentrations of selected carotenoids in llamas (n = 13) and alpacas (n = 27). Serum carotenoids as well as retinol (vitamin A) and α-tocopherol (vitamin E) were determined by high-performance liquid chromatography coupled with mass spectrometry and these were unable to detect any carotenoids (α- and β-carotene, α- and β-cryptoxanthin, lutein, zeaxanthin, lycopene) in the samples. The concentrations of retinol in alpacas (2.89 ± 1.13 μmol/l; mean ± SD) were higher (p = 0.024) than those found in llamas (2.05 ± 0.87 μmol/l); however, the concentrations of α-tocopherol were not significantly (p = 0.166) different (llamas: 3.98 ± 1.83 μmol/l; alpacas: 4.95 ± 2.14 μmol/l). The results show that both llamas and alpacas are not able to absorb intact carotenoids, but efficiently convert provitamin A carotenoids to retinol. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  5. Effects of Fab' fragments of specific egg yolk antibody (IgY-Fab') against Shewanella putrefaciens on the preservation of refrigerated turbot.

    Science.gov (United States)

    Zhang, Qian; Lin, Hong; Sui, Jianxin; Wang, Jingxue; Cao, Limin

    2015-01-01

    In our previous studies the specific egg yolk antibody (IgY) against Shewanella putrefaciens (one of the specific spoilage organisms for marine products during aerobic chilling storage) demonstrated significant activity to prolong the shelf life of refrigerated fish. The exploitation of the antigen-binding fragment plus the hinge region (IgY-Fab') is now considered a promising method for improving the efficiency of such natural antimicrobial agents. The antimicrobial activity of IgY-Fab' against S. putrefaciens was investigated using refrigerated turbot as samples. By microbial, chemical and sensory tests, it was shown to be able to effectively inhibit bacterial growth and prolong the shelf life of samples, with an efficiency evaluated significantly higher than that of whole IgY with the same molarity. The interaction between IgY agents and S. putrefaciens cells was also investigated, and the IgY-Fab' showed a much greater ability to damage cell membranes than the whole IgY. Compared to whole IgY with the same molarity, IgY-Fab' demonstrated higher and more durable antimicrobial efficiency. Such a result was assumed to be closely related to its structural properties (such as the much lower molecular weight), which may enhance its ability to influence physiological activities of antigen bacteria, especially the property or/and structure of cell membranes. © 2014 Society of Chemical Industry.

  6. Localization of mammary tumors in vivo with 131I-labeled Fab fragments of antibodies against mouse mammary epithelial (MME) antigens

    International Nuclear Information System (INIS)

    Wilbanks, T.; Peterson, J.A.; Miller, S.; Kaufman, L.; Ortendahl, D.; Ceriani, R.L.

    1981-01-01

    The Fab fragments of antibodies against cell-type-specific surface antigens of mouse mammary epithelial cells (MME-antigens) were used to localize mammary tumors successfully. The radioiodine-labeled anti-MME (Fab) was injected into mice carrying simulated mammary metastases, and after 24 hours the amount of label per gram of excised tissue was several times greater in the tumor than in liver, brain, lung, or muscle. Kidney showed considerable accumulation of label but this appeared to be nonspecific. Kinetic studies revealed a rapid elimination of labeled Fab in the urine with only 1% of the injected dose remaining in the entire blood pool after 24 hours. Wit a high-purity germanium camera, mammary tumors were clearly located ty the 131 I-labeled anti-MME (Fab), and normalization to /sup 99m/Tc-pertechnetate distribution in the animal increased the specificity. The density of 131 I-label was fourfold greater over the mammary tumor than over comparable areas of the mouse. No accumulation of 131 I-anti-MME (Fab) was observed in nonmammary tumors nor in mammary tumors when labeled nonspecific Fab was used. An analogous system using an antihuman mammary epithelial antiserum is being developed for localization of breast metastases in humans

  7. Crystal structure of the antigen-binding fragment of a monoclonal antibody specific for the multidrug-resistance-linked ABC transporter human P-glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Esser, Lothar; Shukla, Suneet; Zhou, Fei; Ambudkar, Suresh V.; Xia, Di

    2016-07-27

    P-glycoprotein (P-gp) is a polyspecific ATP-dependent transporter linked to multidrug resistance in cancers that plays important roles in the pharmacokinetics of a large number of drugs. The drug-resistance phenotype of P-gp can be modulated by the monoclonal antibody UIC2, which specifically recognizes human P-gp in a conformation-dependent manner. Here, the purification, sequence determination and high-resolution structure of the Fab fragment of UIC2 (UIC2/Fab) are reported. Purified UIC2/Fab binds human P-gp with a 1:1 stoichiometry. Crystals of UIC2/Fab are triclinic (space groupP1), with unit-cell parametersa= 40.67,b= 44.91,c= 58.09 Å, α = 97.62, β = 99.10, γ = 94.09°, and diffracted X-rays to 1.6 Å resolution. The structure was determined by molecular replacement and refined to 1.65 Å resolution. The asymmetric unit contains one molecule of UIC2/Fab, which exhibits a positively charged antigen-binding surface, suggesting that it might recognize an oppositely charged extracellular epitope of P-gp.

  8. 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

  9. Morphometric analysis of llama (Lama glama) sperm head.

    Science.gov (United States)

    Casaretto, C; Lombardo, D M; Giuliano, S; Gambarotta, M; Carretero, M I; Miragaya, M H

    2012-05-01

    Llama production in Argentina has increased, as the international interest in breeding this type of animals has grown in the last years. Considering the great polymorphism that llama spermatozoa present at evaluation using light microscopy, the aim of this study was to objectively evaluate llama sperm head morphometry using digital morphometric analysis. Five ejaculates from each of eight males were obtained to evaluate morphometric parameters of 8000 sperm heads stained with Tinción 15(®). The following average results were obtained for each parameter: size parameters: area 20.09 μm(2), length 6.60 μm, width 4.14 μm, equivalent circle diameter 5.06 μm, curve length 5.79 μm and curve width 3.48 μm; boundary parameters: perimeter 18.54 μm and convex perimeter 17.34 μm; and shape parameters: roundness 1.28 and elongation 1.59. Morphometric parameters of sperm head were compared between ejaculates of the same male and between males. Significant differences between ejaculates of the same male were found for all parameters evaluated (P < 0.01). Significant differences between males were found for all morphometric parameters (P < 0.01) except for curve length, curve width and perimeter. The differences detected would indicate that there is not a single morphometric pattern for Lama glama sperm head, because parameter values cannot be standardised. © 2011 Blackwell Verlag GmbH.

  10. Pituitary null cell adenoma in a domestic llama (Lama glama).

    Science.gov (United States)

    Chalkley, M D; Kiupel, M; Draper, A C E

    2014-07-01

    Pituitary gland neoplasia has been reported rarely in camelids. A 12-year-old neutered male llama (Lama glama) presented with lethargy, inappetence and neurological signs. On physical examination, the llama was mentally dull and exhibited compulsive pacing and circling to the left. Complete blood count and serum biochemistry revealed haemoconcentration, mild hypophosphataemia, hyperglycaemia, hypercreatininaemia and hyperalbuminaemia. Humane destruction was elected due to rapid clinical deterioration and poor prognosis. Post-mortem examination revealed a pituitary macroadenoma and bilateral internal hydrocephalus. Microscopically, the pituitary tumour was composed of neoplastic chromophobic pituitary cells. Ultrastructural studies revealed similar neoplastic cells to those previously described in human null cell adenomas. Immunohistochemically, the neoplastic cells were strongly immunoreactive for neuroendocrine markers (synaptophysin and chromogranin A), but did not exhibit immunoreactivity for epithelial, mesenchymal, neuronal and all major pituitary hormone markers (adrenocorticotropic hormone, follicle stimulating hormone, growth hormone, luteinizing hormone, melanocyte-stimulating hormone, prolactin and thyroid stimulating hormone), consistent with the diagnosis of a pituitary null cell adenoma. This is the first report of pituitary neoplasia in a llama. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Effects of an Aβ-antibody fragment on Aβ aggregation and astrocytic uptake are modulated by apolipoprotein E and J mimetic peptides.

    Directory of Open Access Journals (Sweden)

    Laia Montoliu-Gaya

    Full Text Available Aβ-Immunotherapy has long been studied in the treatment of Alzheimer's disease (AD, but not how other molecules involved in the disease can affect antibody performance. We previously designed an antibody fragment, scFv-h3D6, and showed that it precludes Aβ-induced cytotoxicity by withdrawing Aβ oligomers from the amyloid pathway towards a non-toxic, worm-like pathway. ScFv-h3D6 was effective at the behavioral, cellular, and molecular levels in the 3xTg-AD mouse model. Because scFv-h3D6 treatment restored apolipoprotein E (apoE and J (apoJ concentrations to non-pathological values, and Aβ internalization by glial cells was found to be decreased in the presence of these apolipoproteins, we now aimed to test the influence of scFv-h3D6 on Aβ aggregation and cellular uptake by primary human astrocytes in the presence of therapeutic apoE and apoJ mimetic peptides (MPs. Firstly, we demonstrated by CD and FTIR that the molecules used in this work were well folded. Next, interactions between apoE or apoJ-MP, scFv-h3D6 and Aβ were studied by CD. The conformational change induced by the interaction of Aβ with apoE-MP was much bigger than the induced with apoJ-MP, in line with the observed formation of protective worm-like fibrils by the scFv-h3D6/Aβ complex in the presence of apoJ-MP, but not of apoE-MP. ScFv-h3D6, apoJ-MP, and apoE-MP to a different extent reduced Aβ uptake by astrocytes, and apoE-MP partially interfered with the dramatic reduction by scFv-h3D6 while apoJ-MP had no effect on scFv-h3D6 action. As sustained Aβ uptake by astrocytes may impair their normal functions, and ultimately neuronal viability, this work shows another beneficence of scFv-h3D6 treatment, which is not further improved by the use of apoE or apoJ mimetic peptides.

  12. 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

  13. Development and validation of an antigen-binding capture ELISA for native and putrescine-modified anti-tetanus F(ab')2 fragments for the assessment of the cellular uptake and plasma kinetics of the antibodies.

    OpenAIRE

    Welfringer, Frédéric; D'Athis, Philippe; Scherrmann, Jean-Michel; Hervé, Françoise

    2005-01-01

    International audience; Cationization is a strategy to enhance the permeability of antibodies to physiological membranes for potential therapeutic and diagnostic applications of these proteins, with one of its crucial points being the retention of antigen binding activity. Here, we describe the cationization of horse polyclonal anti-tetanus F(ab')(2) fragments and the development and validation of an ELISA for quantitative measurements of the binding activity of the native and cationized F(ab...

  14. Squamous cell carcinoma originating from a cutaneous scar in a llama.

    Science.gov (United States)

    Rogers, K; Barrington, G M; Parish, S M

    1997-01-01

    A nonhealing wound associated with a laceration in a 12-year-old llama was evaluated. Initial attempts at closure were unsuccessful and biopsy revealed scar tissue. Subsequent biopsies, 18 mo later, revealed squamous cell carcinoma with regional metastasis. This report describes squamous cell carcinoma, secondary to a traumatic wound in a llama. Images Figure 1. Figure 2. PMID:9332750

  15. Squamous cell carcinoma originating from a cutaneous scar in a llama.

    OpenAIRE

    Rogers, K; Barrington, G M; Parish, S M

    1997-01-01

    A nonhealing wound associated with a laceration in a 12-year-old llama was evaluated. Initial attempts at closure were unsuccessful and biopsy revealed scar tissue. Subsequent biopsies, 18 mo later, revealed squamous cell carcinoma with regional metastasis. This report describes squamous cell carcinoma, secondary to a traumatic wound in a llama.

  16. Assessment of the effects of feed restriction and amino acid supplementation on glucose tolerance in llamas.

    Science.gov (United States)

    Cebra, Christopher K; Tornquist, Susan J; Jester, Rebecca M; Stelletta, Calogero

    2004-07-01

    To assess the effects of prolonged feed deprivation on glucose tolerance, insulin secretion, and lipid homeostasis in llamas. 9 adult female llamas. On each of 2 consecutive days, food was withheld from the llamas for 8 hours. Blood samples were collected before and 5, 15, 30, 45, 60, 120, and 240 minutes after IV injection of dextrose (0.5 g/kg) for determination of plasma insulin and serum glucose, triglyceride, and nonesterified fatty acid concentrations. Between experimental periods, the llamas received supplemental amino acids IV (185 mg/kg in solution). The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 23 days, after which the experimental procedures were repeated. Feed restriction decreased glucose tolerance and had slight effects on insulin secretion in llamas. Basal lipid fractions were higher after feed restriction, but dextrose administration resulted in similar reductions in serum lipid concentrations with and without feed restriction. Insulin secretion was decreased on the second day of each study period, which lessened reduction of serum lipid concentrations but did not affect glucose tolerance. Despite having a comparatively competent pancreatic response, feed-restricted llamas assimilated dextrose via an IV bolus more slowly than did llamas on full rations. However, repeated administration of dextrose reduced insulin secretion and could promote hyperglycemia and fat mobilization. These findings suggested that veterinarians should use alternative methods of supplying energy to camelids with long-term reduced feed intake or consider administering agents to improve the assimilation of glucose.

  17. Noninvasive detection of cardiac repair after acute myocardial infarction in rats by 111In fab fragment of monoclonal antibody specific for tenascin-C

    International Nuclear Information System (INIS)

    Okada, Kenichi; Uehara, Tomoya; Arano, Yasushi

    2008-01-01

    Left ventricular (LV) remodeling after acute myocardial infarction (MI) causes heart failure, and thus it is important to evaluate cardiac repair as the early stage of LV remodeling. Tenascin-C (TNC), an extracellular matrix glycoprotein, is transiently and abundantly expressed in the heart during the early stage of tissue remodeling after MI. However, it is not expressed in healthy adult heart. This study was undertaken to develop a new noninvasive diagnostic technique to detect cardiac repair after acute MI using 111 In Fab fragment of a monoclonal antibody specific for TNC. 111 In-anti-TNC-Fab was injected intravenously in 13 rats at 1 (D1, n=3), 3 (D3, n=5), and 5 (D5, n=5) days after producing MI and in 5 sham-operated rats (S). We performed autoradiography and dual-isotope single-photon emission computed tomography imaging (SPECT) of 111 In-anti-TNC-Fab and 99m Tc methoxyisobutyl isonitrile (MIBI). The radioactivity in the heart was significantly higher in D (D1, 0.45±0.06% injected-dose/g; D3, 0.64±0.12; D5, 0.38±0.07) than S (0.27±0.06, P 111 In-anti-TNC-Fab, which was complementary to the perfusion image. The results of the present study indicated that we can localize the infarcted region in the heart by ex vivo and in vivo imaging methods using 111 In-anti-TNC-Fab, and suggested the potential usefulness of noninvasive detection of cardiac repair. (author)

  18. Inhibition of the Myotoxicity Induced by Bothrops jararacussu Venom and Isolated Phospholipases A2 by Specific Camelid Single-Domain Antibody Fragments.

    Directory of Open Access Journals (Sweden)

    Nidiane D R Prado

    Full Text Available Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II, two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs and immunoglobulin frameworks (FRs of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718 were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607 neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem.

  19. 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

  20. Mapping the epitopes of a neutralizing antibody fragment directed against the lethal factor of Bacillus anthracis and cross-reacting with the homologous edema factor.

    Directory of Open Access Journals (Sweden)

    Philippe Thullier

    Full Text Available The lethal toxin (LT of Bacillus anthracis, composed of the protective antigen (PA and the lethal factor (LF, plays an essential role in anthrax pathogenesis. PA also interacts with the edema factor (EF, 20% identity with LF to form the edema toxin (ET, which has a lesser role in anthrax pathogenesis. The first recombinant antibody fragment directed against LF was scFv 2LF; it neutralizes LT by blocking the interaction between PA and LF. Here, we report that scFv 2LF cross-reacts with EF and cross-neutralizes ET, and we present an in silico method taking advantage of this cross-reactivity to map the epitope of scFv 2LF on both LF and EF. This method identified five epitope candidates on LF, constituted of a total of 32 residues, which were tested experimentally by mutating the residues to alanine. This combined approach precisely identified the epitope of scFv 2LF on LF as five residues (H229, R230, Q234, L235 and Y236, of which three were missed by the consensus epitope candidate identified by pre-existing in silico methods. The homolog of this epitope on EF (H253, R254, E258, L259 and Y260 was experimentally confirmed to constitute the epitope of scFv 2LF on EF. Other inhibitors, including synthetic molecules, could be used to target these epitopes for therapeutic purposes. The in silico method presented here may be of more general interest.

  1. Biogas production from llama and cow manure at high altitude

    International Nuclear Information System (INIS)

    Alvarez, Rene; Villca, Saul; Liden, Gunnar

    2006-01-01

    Methane production from llama and cow manures from the Bolivian high plateau (The 'Altiplano') was studied using a parallel reactor set-up consisting of 10 lab-scale biogasifiers. The effects of pressure (495 and 760mmHg), temperature (11 and 35 deg. C), hydraulic retention time (20 and 50 days), and manure content in the slurry (10%, 20% and 50%) were evaluated with respect to productivity and methane yields based on two 2 4-1 fractional factorial designs with 8 treatments for each kind of manure. The reactors were operated semi-continuously with daily manure feeding for periods between 50 and 100 days. Temperature was the main factor effect found, and the hydraulic retention time and the manure content in feed were also found significant whereas the effect of pressure was not significant in the range studied. The methane yield obtained with cow manure at 11 - bar C was between 6.4 and 33.6lCH 4 kg -1 VS (volatile solids added) whereas at 35 deg. C the methane yield was between 49.6 and 131.3lCH 4 kg -1 VS. The methane yield from llama manure was somewhat lower than for cow manure (between 3.3 and 19.3lCH 4 kg -1 VS at 11 deg. C and between 35.6 and 84.1lCH 4 kg -1 VS at 35 deg. C, respectively). However, overall llama manure was found to be the best raw material of the two for biogas production, due to its high content of volatile solid-higher than has been previously reported for most manures-and also its high nitrogen and phosphorous content

  2. Entry of blood urea into the rumen of the llama

    International Nuclear Information System (INIS)

    Hinderer, S.; Engelhardt, W. von

    1976-01-01

    Transfer of body urea into the temporarily isolated rumen cleaned and filled with a test solution was measured in the llama. Simultaneously urea recirculation into the total gastro-intestinal tract (GI-tract) was estimated using 14 C-urea. The permeability of the rumen wall to urea could be changed significantly. With CO 2 or butyric acid in the test solution, permeability was highest, it was low when food was withheld and when no volatile fatty acids were present in the solution. Changes in the permeability can affect the transfer of blood urea across the rumen wall more extensively than changes in plasma urea concentrations. (author)

  3. LLAMA: A new mm and submm observing facility

    Science.gov (United States)

    Arnal, E. M.; Abraham, Z.; Cappa, C.; Giménez de Castro, G.; da Gouveia dal Pino, E. M.; Larrarte, J. J.; Lepine, J.; Viramonte, J.

    2017-07-01

    The current status of the project LLAMA, acronym of Large Latin American Millimetre Array is very briefly described in this paper. This project is a joint scientific and technological undertaking of Argentina and Brazil on the basis of an equal investment share, whose mail goal is both to install and to operate an observing facility capable of exploring the Universe at millimetre and sub/millimetre wavelengths. This facility will be erected in the argentinean province of Salta, at a site located 4830m above sea level.

  4. 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.

  5. Comparison of two cooling protocols for llama semen: with and without collagenase and seminal plasma in the medium.

    Science.gov (United States)

    Carretero, M I; Giuliano, S M; Arraztoa, C C; Santa Cruz, R C; Fumuso, F G; Neild, D M

    2017-08-01

    Seminal plasma (SP) of South American Camelids could interfere with the interaction of spermatozoa with the extenders; therefore it becomes necessary to improve semen management using enzymatic treatment. Our objective was to compare two cooling protocols for llama semen. Twelve ejaculates were incubated in 0.1% collagenase and then were divided into two aliquots. One was extended in lactose and egg yolk (LEY) (Protocol A: collagenase and SP present). The other aliquot was centrifuged, and the pellet was resuspended in LEY (Protocol B: collagenase and SP absent). Both samples were maintained at 5°C during 24 hr. Routine and DNA evaluations were carried out in raw and cooled semen. Both cooling protocols maintained sperm viability, membrane function and DNA fragmentation, with Protocol A showing a significantly lowered total and progressive motility (p semen samples prior to either cooling or freeze-thawing. © 2016 Blackwell Verlag GmbH.

  6. Preparation, biodistribution and dosimetry of copper-64-labeled anti-colorectal carcinoma monoclonal antibody fragments 1A3-F(ab')2

    International Nuclear Information System (INIS)

    Anderson, C.J.; Schwarz, S.W.; Connett, J.M.

    1995-01-01

    Antibody fragments labeled with a radiometal using bifunctional chelates generally undergo renal clearance followed by trapping of the metabolites, leading to high radiation doses to the kidneys. Copper-64-labeled BAT-2IT-1A3-F(ab') 2 was recently reported to accumulate in colorectal tumors in an animal model, however, kidney uptake was also high. In this study, the preparation of 64 Cu-BAT-2IT-1A3-F(ab') 2 was optimized to reduce the renal uptake. The bifunctional chelate 6-bromoacetamidobenzyl-1,4,8,11-tetraazacyclotetradecane-N,N',N double-prime,N'double-prime-tetraacetic acid (BAT) was conjugated to 1A3-F(ab') 2 using the linking agent 2-iminothiolane (2IT). The conjugation reaction produced 20% of a lower molecular weight impurity found to be TETA-1A3-Fab'. The conjugation procedure was optimized to include FPLC purification of the BAT-2IT-1A3-F(ab') 2 from TETA-1A3-Fab' after conjugation prior to labeling with 64 Cu. The biodistribution of 64 Cu-labeled FPLC-purified and unpurified conjugates was determined in normal Sprague-Dawley rats and tumor-bearing Golden Syrian hamsters. Human absorbed doses were calculated from rat biodistribution data and PET imaging of a baboon. Upon FPLC purification of the BAT-2IT-1A3-F(ab') 2 , the immunoreactivity of 64 Cu-labeled 1A3-F(ab') 2 was significantly improved over that of non-FPLC-purified 64 Cu-BAT-2IT-1A3-F(ab') 2 , and the kidney uptake was decreased in normal rats. The biodistribution in hamsters showed some improvement in both tumor uptake and kidney clearance with FPLC-purified 64 Cu-BAT-2IT-1A3-F(ab') 2 .The improved dosimetry of 64 Cu-labeled FPLC purified BAT-2IT-1A3-F(ab') 2 should more readily allow this agent to be investigated clinically to image colorectal cancer using PET. 33 refs., 7 figs., 3 tabs

  7. PET Imaging of Macrophage Mannose Receptor-Expressing Macrophages in Tumor Stroma Using 18F-Radiolabeled Camelid Single-Domain Antibody Fragments.

    Science.gov (United States)

    Blykers, Anneleen; Schoonooghe, Steve; Xavier, Catarina; D'hoe, Kevin; Laoui, Damya; D'Huyvetter, Matthias; Vaneycken, Ilse; Cleeren, Frederik; Bormans, Guy; Heemskerk, Johannes; Raes, Geert; De Baetselier, Patrick; Lahoutte, Tony; Devoogdt, Nick; Van Ginderachter, Jo A; Caveliers, Vicky

    2015-08-01

    Tumor-associated macrophages constitute a major component of the stroma of solid tumors, encompassing distinct subpopulations with different characteristics and functions. We aimed to identify M2-oriented tumor-supporting macrophages within the tumor microenvironment as indicators of cancer progression and prognosis, using PET imaging. This can be realized by designing (18)F-labeled camelid single-domain antibody fragments (sdAbs) specifically targeting the macrophage mannose receptor (MMR), which has been identified as an important biomarker on this cell population. Cross-reactive anti-MMR sdAbs were generated after immunization of an alpaca with the extracellular domains of both human and mouse MMR. The lead binder was chosen on the basis of comparisons of binding affinity and in vivo pharmacokinetics. The PET tracer (18)F-fluorobenzoate (FB)-anti-MMR sdAb was developed using the prosthetic group N-succinimidyl-4-(18)F-fluorobenzoate ((18)F-SFB), and its biodistribution, tumor-targeting potential, and specificity in terms of macrophage and MMR targeting were evaluated in mouse tumor models. Four sdAbs were selected after affinity screening, but only 2 were found to be cross-reactive for human and mouse MMR. The lead anti-MMR 3.49 sdAb, bearing an affinity of 12 and 1.8 nM for mouse and human MMR, respectively, was chosen for its favorable in vivo biodistribution profile and tumor-targeting capacity. (18)F-FB-anti-MMR 3.49 sdAb was synthesized with a 5%-10% radiochemical yield using an automated and optimized protocol. In vivo biodistribution analyses showed fast clearance via the kidneys and retention in MMR-expressing organs and tumor. The kidney retention of the fluorinated sdAb was 20-fold lower than a (99m)Tc-labeled counterpart. Compared with MMR- and C-C chemokine receptor 2-deficient mice, significantly higher uptake was observed in tumors grown in wild-type mice, demonstrating the specificity of the (18)F tracer for MMR and macrophages, respectively. Anti

  8. Radiolabeled Antibody Fragment for Preparation of (177Lu-DOTAm-PAMAM G3.0-F(ab’2 trastuzumab as a Radiopharmaceutical for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    R.D. Haryuni

    2017-06-01

    Full Text Available Several radiolabeled monoclonal antibodies (mAbs have been used as radioimmunotherapy (RIT agents for cancer therapy. The use of mAbs as RIT agents is due to their ability to carry effectors, in the form of radionuclides which emit alpha (α particles, beta (β particles, or auger electrons, and bind specifically to cancer expressed receptor. This paper reports the preparation of radiolabelled trastuzumab in form of (177Lu-DOTAm-PAMAM G3-F(ab'2-trastuzumab, which will be expected as a potential RIT agent for therapy of breast cancer overexpressed human epidermal growth factor receptor 2 (HER2. Due to its reduced molecular weight, the use of F(ab'2-trastuzumab on the aforementioned RIT agent candidate is expected to reach its target much faster compared to the intact trastuzumab. Meanwhile, the role of PAMAM G3 is to increase the specific activity of the radiotherapeutic agent of Lu-177 due to the ability of its 32 –NH2 functional groups that are able to bind many DOTAs (£ 31 which in turn can bind a large number of 177Lu. The preparation was initiated by fragmentation of trastuzumab using pepsin enzyme in 0.02 M acetic acid buffer with a pH of 4.5 to produce F(ab'2-trastuzumab with a purity of 95 % after purification with PD-10 column. The F(ab'2-trastuzumab was then reacted with succinimidyl 4-(N-maleimidomethyl cyclohexane-1-carboxylate (SMCC to produce SMCC-F(ab'2-trastuzumab. The next reaction was to conjugate SMCC-F(ab'2-trastuzumab with DOTA-PAMAM G3.0-SH, which was prepared by reaction NHS-DOTA with PAMAM G3.0 and followed by reacting it with 2-iminothiolane to give (DOTAm-PAMAM G3.0-F(ab'2-trastuzumab. Finally, the (DOTAm-PAMAM G3.0-F(ab'2-trastuzumab was radiolabelled with 177Lu to produce (177Lu-DOTAm-PAMAM G3.0-F(ab'2-trastuzumab, resulting in a radiochemical purity of 98 % after purification with PD-10 column.Received: 31 October 2015; Revised: 30 June 2016; Accepted: 25 September 2016

  9. Traditional llama husbandry and breeding management in the Ayopaya region, Bolivia.

    Science.gov (United States)

    Markemann, A; Valle Zárate, A

    2010-01-01

    The llama claims the largest population of the domestic South American camelids, most of which are raised in Bolivia. More than 53,000 rural families are dedicated to llama husbandry as part of their livelihood strategy. Contemporary Andean societies deliberately select animals for specific traits and employ substantial livestock management to secure subsistence. This study presents traditional llama husbandry and breeding management activities in the Ayopaya region, Bolivia. Traditional selection traits for male and female llamas are documented and assessed by a ranking and a ratio-scaled evaluation. Husbandry and management parameters are in concordance with other studies conducted in the region, but show a high variation. Average llama herd sizes are rather small (mu = 45.6). In some herds, breeding males are utilized for a long time and mix with other herds, causing concerns about inbreeding. Preferred trait groups for llama males according to farmers' responses were body conformation, fibre, testicle conformation, fleece colour and height at withers. Traditional selection criteria generally relate to the phenotype, but also include the commercially interesting fibre trait. The presented results should be considered in breeding and management programmes for the respective llama population to ensure sustainable use of this genetically and culturally valuable resource.

  10. Llama oviductal sperm reservoirs: involvement of bulbourethral glands.

    Science.gov (United States)

    Apichela, S A; Argañaraz, M E; Giuliano, S; Zampini, R; Carretero, I; Miragaya, M; Miceli, D C

    2014-04-01

    The aim of this study was to elucidate the role of llama seminal plasma in the formation of oviductal sperm reservoirs. Female llamas with follicles in the mature phase were mated with a bulbourethral glands-removed male. Females mated with nonbulbourethral glands-removed males were used as control. Oviducts were obtained by surgery 24 h after mating. The uterotubal junction and isthmus were examined by scanning electron microscopy, and mucopolysaccharides were identified by Alcian blue staining. To know the proteins probably involved in sperm reservoir formation, SDS-PAGE of seminal plasma (8% and 18% resolving gel) was made. Spermatozoa only adhered to the oviductal mucosa surface of uterotubal junction of females mated with nonbulbourethral glands-removed males confirming that seminal plasma and, in particular, bulbourethral secretions are related with the oviductal sperm reservoir formation. Histological sections showed sperm in the lumen, immersed in substance, positive for acid mucopolysaccharides. Alcian blue staining of seminal plasma proteins SDS-PAGE showed a band of high molecular weight containing mucopolysaccharides, only present in nonbulbourethral glands-removed males. Bulbourethral glands would secrete at least eight different proteins that most likely participate in the process of sperm storage in the oviduct. © 2013 Blackwell Verlag GmbH.

  11. Nutritional support for treatment of hepatic lipidosis in a llama.

    Science.gov (United States)

    Van Saun, R J; Callihan, B R; Tornquist, S J

    2000-11-15

    A 3-year-old female llama that was 3 months into her first lactation and 10 weeks pregnant was evaluated for anorexia of 24 hours' duration. On physical examination, the llama was in lateral recumbency, bradycardic, tachypneic, and hyperthermic. Palpation per rectum confirmed the presence of a possible dry fecal mass in the spiral colon. A tissue biopsy specimen of the liver was obtained, and histologic examination revealed moderate diffuse lipid accumulation within the hepatocytes. Lactated Ringer's solution was administered for rehydration, and partial parenteral nutrition was then initiated. Hepatic lipidosis is a disease characterized by abnormal accumulation of lipid in the liver and is associated with high mortality in camelids. Anorexia associated with hepatic lipidosis promotes further lipid mobilization and fatty infiltration of the liver. Partial parenteral nutrition with enteral supplementation may be used to maintain adequate energy intake and minimize further lipid mobilization. The distinctive metabolism of camelids may require higher amino acid supplementation relative to nonprotein calories in parenteral solutions than those traditionally provided to other species. Treatment with insulin may be effective

  12. Development of an immunoassay for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) based upon the recombinant Fab fragment of 2,4-D specific antibody

    Science.gov (United States)

    Nguyen, Van C.; Nguyen, Thi D. T.; Dau, Hung A.; Tham, Thu N.; Quyen, Dinh T.; Bachmman, Till; Schmid, Rolf D.

    2001-09-01

    To develop an immunoassay and further an immunosensor for 2,4-D based upon recombinant antibody, the Fab fragments of 2,4-D specific antibody were expressed in E. coli. Western blotting analysis of the periplasmic cell fractions shown that under the non-reducing condition only a single protein band at a molecular mass of 45-kDa, corresponding to the whole Fab fragment was detected. Antigen binding activity for 2,4-D was found only in the extract of cells bearing the 2,4-D plasmid. An immunoassay based on the competitive reaction of 2,4-D and enzyme tracer with 2,4-D Fab fragments immobilized on micro titer plates via rabbit anti-mouse IgC was developed. Using this assay, 2,4-D could be detected at concentration range of 0.5 (mu) g/1 to 10(mu) g/1. The center point of the 2,4-D test was found at a concentration of 5 (mu) g/l. The assay was applied for detection of 2,4-D in spiked orange samples, resulting in recovery rate of 90 percent. The immunoassay could be applied to monitor human exposure to 2,4-D from contamination in fruit samples.

  13. Neutralization of Clostridium difficile Toxin B Mediated by Engineered Lactobacilli That Produce Single-Domain Antibodies

    Science.gov (United States)

    Andersen, Kasper Krogh; Strokappe, Nika M.; Hultberg, Anna; Truusalu, Kai; Smidt, Imbi; Mikelsaar, Raik-Hiio; Mikelsaar, Marika; Verrips, Theo; Hammarström, Lennart

    2015-01-01

    Clostridium difficile is the primary cause of nosocomial antibiotic-associated diarrhea in the Western world. The major virulence factors of C. difficile are two exotoxins, toxin A (TcdA) and toxin B (TcdB), which cause extensive colonic inflammation and epithelial damage manifested by episodes of diarrhea. In this study, we explored the basis for an oral antitoxin strategy based on engineered Lactobacillus strains expressing TcdB-neutralizing antibody fragments in the gastrointestinal tract. Variable domain of heavy chain-only (VHH) antibodies were raised in llamas by immunization with the complete TcdB toxin. Four unique VHH fragments neutralizing TcdB in vitro were isolated. When these VHH fragments were expressed in either secreted or cell wall-anchored form in Lactobacillus paracasei BL23, they were able to neutralize the cytotoxic effect of the toxin in an in vitro cell-based assay. Prophylactic treatment with a combination of two strains of engineered L. paracasei BL23 expressing two neutralizing anti-TcdB VHH fragments (VHH-B2 and VHH-G3) delayed killing in a hamster protection model where the animals were challenged with spores of a TcdA− TcdB+ strain of C. difficile (P survived until the termination of the experiment at day 5 and showed either no damage or limited inflammation of the colonic mucosa despite having been colonized with C. difficile for up to 4 days. The protective effect in the hamster model suggests that the strategy could be explored as a supplement to existing therapies for patients. PMID:26573738

  14. 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.)

  15. Circulating levels of chromatin fragments are inversely correlated with anti-dsDNA antibody levels in human and murine systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Jørgensen, Mariann H; Rekvig, Ole Petter; Jacobsen, Rasmus S

    2011-01-01

    Anti-dsDNA antibodies represent a central pathogenic factor in Lupus nephritis. Together with nucleosomes they deposit as immune complexes in the mesangial matrix and along basement membranes within the glomeruli. The origin of the nucleosomes and when they appear e.g. in circulation is not known...... an inverse correlation between anti-dsDNA antibodies and the DNA concentration in the circulation in both murine and human serum samples. High titer of anti-DNA antibodies in human sera correlated with reduced levels of circulating chromatin, and in lupus prone mice with deposition within glomeruli....... The inverse correlation between DNA concentration and anti-dsDNA antibodies may reflect antibody-dependent deposition of immune complexes during the development of lupus nephritis in autoimmune lupus prone mice. The measurement of circulating DNA in SLE sera by using qPCR may indicate and detect...

  16. /sup 99m/Tc radiolabelling and quality control tests of anti-melanoma monoclonal antibodies and F(ab')/sub 2/ fragments for immunoscintigraphy

    International Nuclear Information System (INIS)

    Callegaro, L.; Deleide, G.; Dovis, M.; Cecconato, E.; Scassellati, G.A.

    1986-01-01

    Tumour radioimmunodetection was first developed by using radiolabelled polyclonal antibodies, raised in goats against tumour associated antigens (TAA). The availability of monoclonal antibodies to TAA has definitely contributed to more extensive in vivo use of radiolabelled antibodies. However, many factors are involved in tumour radioimmunolocalization, related either to the antibody and radioisotope features or to the natural history of the tumour itself. The experimental protocol developed by the authors allows a full evaluation of the properties of a particular MoAb.This paper illustrates the work done with on a particular set of monoclonal antibodies, raised against human melanoma associated antigens, with the aim of visualizing primary and metastatic lesions in melanoma patients

  17. Evaluation of intra-abdominal vasectomy in llamas and alpacas.

    Science.gov (United States)

    Bravo, P W; Sumar, J

    1991-11-01

    A method of intra-abdominal vasectomy (deferentectomy), using a laparoscopic technique in llamas and alpacas, was evaluated. Food was withheld from 14 animals for 24 hours before sedation and laparoscopy. The ductus deferens was located close to the bladder, and a 2- to 3-cm section of ductus deferens was resected with the aid of a pair of hook scissors. The procedure was completed in 5 to 8 minutes, and animals did not have any adverse effects. Forty-five days after vasectomy, animals were used for detecting sexually receptive females or inducing ovulation during reproductive physiologic studies. The procedure did not impair libido and had no effect on male sexual behavior for many years. The technique is simpler, safer, and faster than the traditional external approach.

  18. Entry of blood urea into the rumen of the llama

    International Nuclear Information System (INIS)

    Hinderer, S.; Engelhardt, W. von

    1976-01-01

    Llamas were provided with a large rumen fistula, and the transfer of blood urea into the temporarily isolated rumen, cleaned and filled with test solution was measured. Plasma urea clearance due to transfer of blood urea across the rumen wall should indicate changes in its permeability to urea. Clearance values were highest with CO 2 or with high concentrations of butyric acid. Permeability was low when food was with-held and when no volatile fatty acids were present in the solution. The permeability of the rumen wall to blood urea can be altered significantly. These changes can affect blood urea transfer more extensively than changes in the plasma urea concentration within physiological ranges

  19. Efficacy of anthelmintics on South American camelid (llama and alpaca) farms in Georgia.

    Science.gov (United States)

    Gillespie, Rose-Ann M; Williamson, Lisa H; Terrill, Thomas H; Kaplan, Ray M

    2010-08-27

    The number of South American camelid (SAC; llama and alpaca) farms is growing in the southeastern United States, and infection with gastrointestinal nematodes (GIN) is a major health concern in this region. There is widespread resistance to anthelmintic remedies in small ruminants (sheep and goats), but a paucity of information on llamas and alpacas. Anthelmintic resistance was evaluated on three SAC farms (two llama; one alpaca) in Georgia in the southern United States using fecal egg count reduction (FECR) tests. For each farm, animals were randomly assigned to 1 of 5 treatment groups based on initial fecal egg count (FEC) and number of animals available (2-5 groups, n=9-11 per treatment). Ivermectin (IVM, subcutaneous injection; 0.3mg/kg body weight (BW)) and a control group were tested on an alpaca farm, and fenbendazole (FBZ, oral; 10mg/kg BW; two farms), moxidectin (MOX oral; 0.2mg/kg BW; two farms), and levamisole (LEV, oral; 8 mg/kg BW; one farm) were added for the llama farms. Anthelmintic efficacy was determined by comparing FEC of treatment and control animals 14 days post-treatment, with resistance evaluated using the World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines. Based upon these guidelines, there was GIN resistance to IVM in both llamas and alpacas in Georgia and to FBZ on both llama farms where this drug was tested. There was MOX resistance on one llama farm using the FECR test, while there was no resistance to LEV detected in this study. These data demonstrate a serious emerging problem in the United States of llama and alpaca GIN resistant to drugs from two of the three major anthelmintic classes. (c) 2010 Elsevier B.V. All rights reserved.

  20. 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

  1. 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.

  2. Dulaglutide, a long-acting GLP-1 analog fused with an Fc antibody fragment for the potential treatment of type 2 diabetes

    DEFF Research Database (Denmark)

    Jimenez-Solem, Espen; Rasmussen, Mette H; Christensen, Mikkel

    2010-01-01

    Dulaglutide (LY-2189265) is a novel, long-acting glucagon-like peptide 1 (GLP-1) analog being developed by Eli Lilly for the treatment of type 2 diabetes mellitus (T2DM). Dulaglutide consists of GLP-1(7-37) covalently linked to an Fc fragment of human IgG4, thereby protecting the GLP-1 moiety from...

  3. Optimization of IGF-1R SPECT/CT Imaging Using In-111-Labeled F(ab ')(2) and Fab Fragments of Article the Monoclonal Antibody R1507

    NARCIS (Netherlands)

    Heskamp, Sandra; van Laarhoven, Hanneke W. M.; Molkenboer-Kuenen, Janneke D. M.; Bouwman, Wilbert H.; van der Graaf, Winette T. A.; Oyen, Wim J. G.; Boerman, Otto C.

    2012-01-01

    The insulin-like growth factor 1 receptor (IGF-1R) is a potential new target for the treatment of breast cancer. Patients with breast cancer lesions that express IGF-1R may benefit from treatment with anti-IGF-IR antibodies. IGF-1R expression can be visualized using radiolabeled R1507, a monoclonal

  4. Comparison of IgG and F(ab')2 fragments of bispecific anti-RCCxanti-DTIn-1 antibody for pretargeting purposes.

    NARCIS (Netherlands)

    Schaijk, F.G. van; Boerman, O.C.; Soede, A.C.; McBride, W.J.; Goldenberg, D.M.; Corstens, F.H.M.; Oosterwijk, E.

    2005-01-01

    PURPOSE: An effective pretargeting strategy was developed for renal cell carcinoma (RCC) based on a biologically produced bispecific monoclonal antibody: anti-RCCxanti-DTPA(In) (bsMAb: G250xDTIn-1). Tumour uptake of a (111)In-labelled bivalent peptide after pretargeting with bsMAb G250xDTIn-1 was

  5. Circulating levels of chromatin fragments are inversely correlated with anti-dsDNA antibody levels in human and murine systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Jørgensen, Mariann H; Rekvig, Ole Petter; Jacobsen, Rasmus S

    2011-01-01

    Anti-dsDNA antibodies represent a central pathogenic factor in Lupus nephritis. Together with nucleosomes they deposit as immune complexes in the mesangial matrix and along basement membranes within the glomeruli. The origin of the nucleosomes and when they appear e.g. in circulation is not known...

  6. The effect of repeated administrations of llama ovulation-inducing factor (OIF/NGF) during the peri-ovulatory period on corpus luteum development and function in llamas.

    Science.gov (United States)

    Fernández, A; Ulloa-Leal, C; Silva, M; Norambuena, C; Adams, G P; Guerra, M; Ratto, M H

    2014-10-01

    The objective of the study was to test the hypothesis that repeated administrations of OIF/NGF during the peri-ovulatory period (pre-ovulatory, ovulatory, early post-ovulatory), will enhance the luteotrophic effect in llamas. Female llamas were examined daily by transrectal ultrasonography in B- and Doppler-mode using a scanner equipped with a 7.5-MHz linear-array transducer to monitor ovarian follicle and luteal dynamics. When a growing follicle ≥7mm was detected, llamas were assigned randomly to one of the three groups and given 1mg of purified OIF/NGF im (intramuscular) (a) pre-ovulation (single dose; n=12), (b) pre-ovulation and at the time of ovulation (2 doses, n=10), or (c) pre-ovulation, at the time of ovulation, and 24h after ovulation (3 doses, n=10). The pre-ovulatory follicle diameter at the time of treatment, ovulation rate and the first day of CL detection did not differ (P=0.3) among groups. However, maximum CL diameter was greatest (P=0.003) in llamas in the 2-dose group, and smallest in the 3-dose group. Accordingly, the 2 dose-group had the largest day-to-day profile for CL diameter (Pllama seminal plasma is luteotrophic and the effect on CL size and function is affected by the number and timing of treatments during the peri-ovulatory period. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Spontaneous ovulation or male effect in alpacas and llamas

    Directory of Open Access Journals (Sweden)

    Sumar JB

    2016-08-01

    Full Text Available New discoveries in ovulation induced mammals, researchers considered the question of whether spontaneous and induced ovulations are distinct entities or individual parts of a single continuum of a “malefacilitated oestrus and ovulation”. This rigid classification should be taken with precaution, because is possible that the various mechanisms involved in the spontaneous ovulation can, under specific conditions coexist in some determined species. It is possible that male hormones can provoke the ovulation by masculine pheromones. The “Ram Effect” can be used to synchronize ewes naturally, for artificial insemination. Pheromones are specialized hormones released by the ram and smelled by the ewes; they are found in the wool and wax, in such a way that synchronized the heat and the advancement of the breeding season Also, using artificial vaginal-cervical stimulation (AVS with a glass rod, ovulation has been induced in the mink, shrews and felids. This form of tactile stimulation (AVS has found no ability for induction of ovulation in SAC. Additional stimuli/cues are often necessary to facilitate the ovulatory response. They include olfactory, visual, auditory or posture, more of them very common in SAC. Few research studies in alpacas and llamas showed a variable number of females ovulating by the sole proximity of the male to the female, by adopting the copulatory position (posture (sitting or prone position, female to female mounting (tactile, males mounting females covered with aprons to avoid penis intromission (tactile and auditory, interrupted matings, sitting close to a male copulating to a female (visual, olfactory?, the guttural sound (orgling made by the copulating male (auditory, and probably other non-identified cues. The rate of spontaneous ovulation in alpacas and llamas, increase up to 50% during the breeding season. These spontaneous ovulation has been diagnosed by sexual behavior (female rejection to the male, by

  8. Use of a fragment of glycoprotein G-2 produced in the baculovirus expression system for detecting herpes simplex virus type 2-specific antibodies

    NARCIS (Netherlands)

    Ikoma, M; Liljeqvist, JA; Glazenburg, KL; The, TH; Welling-Wester, S; Groen, J.

    Fragments of glycoprotein G (gG-2(281-594His)), comprising residues 281 to 594 of herpes simplex virus type 2 (HSV-2), glycoprotein G of HSV-1 (gG-1(t26-189His)), and glycoprotein D of HSV-1 (gD-1(1-313)), were expressed in the baculovirus expression system to develop an assay for the detection of

  9. Identification of Lamanema chavezi Becklund 1963 infection in a llama (Lama glama) in the United States.

    Science.gov (United States)

    Jarvinen, Julie Ann C; Whitley, Elizabeth M; Kreuder, Amanda J; Schleining, Jennifer A

    2014-01-01

    Infection with Lamanema chavezi, a parasitic nematode of New World camelids, was diagnosed by examination of feces and formalin-fixed liver from a 14-month-old female llama (Lama glama) that died after a 6-week illness. Infection with L. chavezi was initially suspected when a granuloma containing an unidentified nematode was detected microscopically in the hepatic parenchyma from a necropsy specimen. The subsequent diagnosis of L. chavezi infection was based on the morphologic features of 2 immature nematodes dissected from individual hepatic granulomas, characteristics of eggs detected in feces of the llama by centrifugal flotation in sugar solution (specific gravity: 1.30), development of third-stage larvae within the eggs after incubation of the llama feces at room temperature for ≥30 days, and the morphology of third-stage larvae released from the embryonated eggs. Collectively, these findings indicate that the llama, born and raised in Oregon, harbored an autochthonous L. chavezi infection. Eggs identified as L. chavezi were also detected by centrifugal flotation of pelleted feces from 3 of 7 herd mates of the llama indicating this parasite is endemic in the Oregon herd. The findings reported herein serve to alert diagnosticians and veterinary practitioners to the occurrence of L. chavezi in New World camelids in the United States and describe diagnostic features of this potential pathogen.

  10. Ovulation-inducing factor: a protein component of llama seminal plasma

    Directory of Open Access Journals (Sweden)

    Huanca Wilfredo

    2010-05-01

    Full Text Available Abstract Background Previously, we documented the presence of ovulation-inducing factor (OIF in the seminal plasma of llamas and alpacas. The purpose of the study was to define the biochemical characteristics of the molecule(s in seminal plasma responsible for inducing ovulation. Methods In Experiment 1, llama seminal plasma was centrifuged using filtration devices with nominal molecular mass cut-offs of 30, 10 and 5 kDa. Female llamas (n = 9 per group were treated i.m. with whole seminal plasma (positive control, phosphate-buffered saline (negative control, or the fraction of seminal plasma equal or higher than 30 kDa, 10 to 30 kDa, 5 to 10 kDa, or Results In Experiment 1, all llamas in the equal or higher than 30 kDa and positive control groups ovulated (9/9 in each, but none ovulated in the other groups (P Conclusions We conclude that ovulation-inducing factor (OIF in llama seminal plasma is a protein molecule that is resistant to heat and enzymatic digestion with proteinase K, and has a molecular mass of approximately equal or higher than 30 kDa.

  11. Um metaromance histórico: «Jaguar en Llamas», Arturo Arias

    Directory of Open Access Journals (Sweden)

    Márcia Paraquett

    2011-10-01

    Full Text Available Resumo: O romance histórico Jaguar en llamas, do escritor guatemalteco Arturo Arias, parodia a história de seu país, subvertendo a história oficial, conforme o procedimento utilizado por outros autores hispano-americanos no final do século XX. Esse romance, no entanto, não se constrói segundo o paradigma convencional, o que o torna um meta romance histórico.Palavras-chave: Literatura guatemalteca; Arturo Arias; Jaguar en Llamas; paródia; romance histórico.Resumen: La novela histórica Jaguar en llamas, del escritor gualtemalteco Arturo Arias, parodia la historia de su país, subvertiendo la historia oficial, de acuerdo con el procedimiento de otros autores hispanoamericanos en el fin del siglo XX, aunque no se construya según el paradigma convencional, lo que hace con que esa novela sea leída y vista como una meta novela histórica.Palabras-clave: Literatura guatemalteca; Arturo Arias; Jaguar en Llamas; parodia; novela histórica.Keywords: Guatemalan literature; Arturo Arias; Jaguar en Llamas; parody; historical novel.

  12. Carcass characteristics of llamas (Lama glama) reared in Central Chile.

    Science.gov (United States)

    Pérez; Maino; Guzmán; Vaquero; Köbrich; Pokniak

    2000-07-01

    Body and carcass composition were studied on 10 male and 10 female naturally reared llamas (Lama glama). Half the animals were young (9-12 months) and the other half adult (>3 year). The average live weights for young and adult males were 104.4 and 100.6kg, and for females 67.6 and 104.6kg, respectively. Average carcass weights for the four groups were 58.9, 56.2, 36.8 and 56.7kg, respectively. Carcass composition for males and females was similar, but males had slightly higher dressing percentages than females (56.1 and 55.8 vs. 54.1 and 54.2 for young and adult males and females, respectively). Carcass length and fat depth at the loin and proportions of cuts in the carcass were similar for both the sexes, except for leg and tail, which were proportionately heavier in young females compared to the other groups. The composition of meat on fresh basis was: moisture 70.2%, protein 20.5%, ether extract 8.23% and ash 3.4%. Age and sex seemed to have no effects on the body and carcass characteristics studied nor on the chemical composition of meat.

  13. Jet fragmentation

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1985-10-01

    The paper reviews studies on jet fragmentation. The subject is discussed under the topic headings: fragmentation models, charged particle multiplicity, bose-einstein correlations, identified hadrons in jets, heavy quark fragmentation, baryon production, gluon and quark jets compared, the string effect, and two successful models. (U.K.)

  14. A case of nasal myiasis due to Oestrus ovis (Diptera: Oestridae) in a llama (Lama glama).

    Science.gov (United States)

    Gomez-Puerta, Luis Antonio; Alroy, Karen Ann; Ticona, Daniel Santiago; Lopez-Urbina, Maria Teresa; Gonzalez, Armando Emiliano

    2013-01-01

    Infection by the larval form of Oestrus ovis (sheep bot fly) is common in many areas of Peru. This is an obligate parasite of sheep and goats, and it is the cause of oestrosis, or nasal myiasis, which can lead to severe clinical manifestations in livestock. A case of myiasis caused by O. ovis in a llama (Lama glama) in Cuzco, Peru, is reported here. This llama presented with respiratory distress and died due to bilateral hemorrhagic pneumonia. During the necropsy, six intact dipterous larvae were recovered from the nasal fossae and cranial sinuses being identified as O. ovis. This is the first report of nasal myiasis in llamas due to O. ovis in Peru.

  15. Detection of fiber-digesting bacteria in the forestomach contents of llamas (Lama glama by PCR

    Directory of Open Access Journals (Sweden)

    María E Cerón Cucchi

    Full Text Available The high fibrolytic activity and large biomass of strictly-anaerobic bacteria that inhabit the rumen makes them primarily responsible for the degradation of the forage consumed by ruminants. Llamas feed mainly on low quality fibrous roughages that are digested by an active and diverse microflora. The products of this fermentation are volatile fatty acids and microbial biomass, which will be used by the animals. The aim of this study was to detect the three major fiber-digesting anaerobic bacteria in the forestomach contents of llamas by PCR. In this study, we detected Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes in the forestomach contents of eight native llamas from Argentina.

  16. A case of nasal myiasis due to Oestrus ovis (Diptera: Oestridae in a llama (Lama glama

    Directory of Open Access Journals (Sweden)

    Luis Antonio Gomez-Puerta

    Full Text Available Infection by the larval form of Oestrus ovis (sheep bot fly is common in many areas of Peru. This is an obligate parasite of sheep and goats, and it is the cause of oestrosis, or nasal myiasis, which can lead to severe clinical manifestations in livestock. A case of myiasis caused byO. ovis in a llama (Lama glama in Cuzco, Peru, is reported here. This llama presented with respiratory distress and died due to bilateral hemorrhagic pneumonia. During the necropsy, six intact dipterous larvae were recovered from the nasal fossae and cranial sinuses being identified as O. ovis. This is the first report of nasal myiasis in llamas due to O. ovis in Peru.

  17. Use of computed tomography to evaluate the intestinal tract of adult llamas

    International Nuclear Information System (INIS)

    Van Hoogmoed, L.; Roberts, G.; Snyder, J.R.; Yarbrough, T.; Haromon, F.

    1998-01-01

    In the llama, signs of colic are obscure and may be exhibited as persistent sternal recumbency and anorexia even in the presence of a surgical lesion. Diagnostic methods for evaluation of abdominal disorders are limited. As a result, surgical intervention may be prolonged and increase the risk of mortality and postoperative complications. The objective of this study was to determine the feasibility of computed tomography to evaluate the llama intestinal tract. Eighteen hours prior to the computed tomography scan, six llamas were given barium sulfate (15%) via an orogastric tube. Following induction of general anesthesia, the llamas were positioned in sternal recumbency, and 10 mm contiguous slices were obtained from the diaphragm to the tuber ischiadicum. Structures that were consistently identified included the first, second, and third compartments (C1, 2, and 3), small intestine, spiral colon, and ascending colon. C1 was easily identified in the cranial aspect of the abdomen due to its large size relative to the other compartments and characteristic saccules. C2 was located cranial, ventral, and to the right of C1, while C3 was visualized as a tubular structure to the right and ventral to C1 and C2, C3 was traced caudally until it turned dorsally and continued cranially to a dilated ampulla in the right cranial abdomen delineating the entrance to the small intestine. The spiral colon was identified consistently in the left ventral caudal abdomen. Structures that could not be conclusively identified included the cecum and mesenteric lymph nodes. Computed tomography allowed a consistent evaluation of the major intestinal structures associated with colic in the llama. Thus, computed tomography is a potentially valuable noninvasive diagnostic tool to effectively evaluate the abdominal cavity and differentiate medical from surgical lesions in the llama

  18. Crystal structure of snake venom acetylcholinesterase in complex with inhibitory antibody fragment Fab410 bound at the peripheral site: evidence for open and closed states of a back door channel.

    Science.gov (United States)

    Bourne, Yves; Renault, Ludovic; Marchot, Pascale

    2015-01-16

    The acetylcholinesterase found in the venom of Bungarus fasciatus (BfAChE) is produced as a soluble, non-amphiphilic monomer with a canonical catalytic domain but a distinct C terminus compared with the other vertebrate enzymes. Moreover, the peripheral anionic site of BfAChE, a surface site located at the active site gorge entrance, bears two substitutions altering sensitivity to cationic inhibitors. Antibody Elec410, generated against Electrophorus electricus acetylcholinesterase (EeAChE), inhibits EeAChE and BfAChE by binding to their peripheral sites. However, both complexes retain significant residual catalytic activity, suggesting incomplete gorge occlusion by bound antibody and/or high frequency back door opening. To explore a novel acetylcholinesterase species, ascertain the molecular bases of inhibition by Elec410, and document the determinants and mechanisms for back door opening, we solved a 2.7-Å resolution crystal structure of natural BfAChE in complex with antibody fragment Fab410. Crystalline BfAChE forms the canonical dimer found in all acetylcholinesterase structures. Equally represented open and closed states of a back door channel, associated with alternate positions of a tyrosine phenol ring at the active site base, coexist in each subunit. At the BfAChE molecular surface, Fab410 is seated on the long Ω-loop between two N-glycan chains and partially occludes the gorge entrance, a position that fully reflects the available mutagenesis and biochemical data. Experimentally based flexible molecular docking supports a similar Fab410 binding mode onto the EeAChE antigen. These data document the molecular and dynamic peculiarities of BfAChE with high frequency back door opening, and the mode of action of Elec410 as one of the largest peptidic inhibitors targeting the acetylcholinesterase peripheral site. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Construction of bifunctional molecules specific to antigen and antibody’s Fc-fragment by fusion of scFv-antibodies with staphylococcal protein A

    Directory of Open Access Journals (Sweden)

    Kolibo D. V.

    2009-06-01

    Full Text Available Aim. To develop approach for detection of scFv and their complexes with antigens. Methods. The fusion proteins, which include sequences of scFv and staphylococcal protein A, were constructed and the obtained bifunctional molecules were immunochemically analysed. Results. It was shown, that scFv fused with protein A and their complexes with antigens are effectively recognized by labelled immunoglobulins with unrestricted antigenic specificity. Conclusions. The fusion of scFv with protein A fragment is a perspective approach to increase the efficiency of application in ELISA. The obtained scFv, fused with protein A, could be used for development of test-systems for the detection of diphtheria toxin.

  20. Thrombus imaging with indium-111 and iodine-131-labeled fibrin-specific monoclonal antibody and its F(ab')2 and Fab fragments

    International Nuclear Information System (INIS)

    Rosebrough, S.F.; Grossman, Z.D.; McAfee, J.G.

    1988-01-01

    We have previously reported successful imaging of fresh (2-4 hr old) and aged (1-5 days old) canine thrombi with 131 I-labeled intact monoclonal antibody (MAb) specific for fibrin. We now report thrombus imaging with 131 I-labeled F(ab')2 and Fab and 111 In-labeled intact MAb, F(ab')2, and Fab. Indium-111-labeled F(ab')2 proved to be the best imaging agent due to less nonspecific binding in the liver than whole IgG. Image quality was improved by the higher administered dose permissible with 111 In and its better physical characteristics for imaging, compared to 131 I. Immunofluorescence of fresh human histologic sections showed intact MAb and F(ab')2 binding to thrombi, pulmonary emboli, and atherosclerotic plaques, strengthening the feasibility of clinical thrombus imaging

  1. Development and validation of an antigen-binding capture ELISA for native and putrescine-modified anti-tetanus F(ab')2 fragments for the assessment of the cellular uptake and plasma kinetics of the antibodies.

    Science.gov (United States)

    Welfringer, Frédéric; d'Athis, Philippe; Scherrmann, Jean-Michel; Hervé, Françoise

    2005-12-20

    Cationization is a strategy to enhance the permeability of antibodies to physiological membranes for potential therapeutic and diagnostic applications of these proteins, with one of its crucial points being the retention of antigen binding activity. Here, we describe the cationization of horse polyclonal anti-tetanus F(ab')(2) fragments and the development and validation of an ELISA for quantitative measurements of the binding activity of the native and cationized F(ab')(2) in cell lysates and rat plasma samples, assessing the cellular uptake and plasma kinetics of these antibodies, respectively. The method used tetanus anatoxin coated on microtitre plates as capture antigen to bind sample or standard F(ab')(2), the amount of antibody binding being quantified using, first, a secondary biotinylated anti-horse antibody/streptavidin-alkaline phosphatase complex in situ and then a measurement of the substrate product. Cationization of the F(ab')(2) was performed with putrescine at pH 4.5 using soluble carbodiimide as carboxyl activator. The average substitution ratio was determined at 3 putrescine molecules per F(ab')(2) molecule. The cationized F(ab')(2) retained roughly 80% of the initial antigen binding activity and was stable over a 1 year period of storage at -20 degrees C. The ELISA validation data showed that the method was linear for both the native and cationized F(ab')(2) using Hanks' balanced saline solution with 0.2% bovine serum albumin as assay diluent for the cell lysate samples. The useful F(ab')(2) concentration range was 2.5-25 ng/ml and the limit of quantification was 2.5 ng/ml. With rat blank plasma used as assay diluent for the rat plasma samples the useful F(ab')(2) concentration range was 3.5-25 ng/ml and the limit of quantification was 3.5 ng/ml. Specific requirements for the limits of quantification were fulfilled: precision tetanus F(ab')(2) in an HL 60 cell model, and of plasma kinetics after i.v. administration to rats.

  2. Middle East respiratory syndrome coronavirus specific antibodies in naturally exposed Israeli llamas, alpacas and camels

    NARCIS (Netherlands)

    David, D. (Dan); Rotenberg, D. (Ditza); Khinich, E. (Evgeny); Erster, O. (Oran); Bardenstein, S. (Svetlana); van Straten, M. (Michael); N.M.A. Okba (Nisreen); Raj, S.V. (Stalin V.); B.L. Haagmans (Bart); Miculitzki, M. (Marcelo); Davidson, I. (Irit)

    2018-01-01

    textabstractThus far, no human MERS-CoV infections have been reported from Israel. Evidence for the circulation of MERS-CoV in dromedaries has been reported from almost all the countries of the Middle East, except Israel. Therefore, we aimed to analyze MERS-CoV infection in Israeli camelids, sampled

  3. Crystallization and diffraction properties of the Fab fragment of 3B5H10, an antibody specific for disease-causing polyglutamine stretches

    International Nuclear Information System (INIS)

    Peters-Libeu, Clare; Newhouse, Yvonne; Krishnan, Preethi; Cheung, Kenneth; Brooks, Elizabeth; Weisgraber, Karl; Finkbeiner, Steven

    2005-01-01

    Optimization of crystallization conditions and cryoprotectants decreased the anisotropy of the diffraction obtained from 3B5H10 Fab crystals. Dehydration improved the resolution of cryoprotected 3B5H10 crystals from 2.6 to 1.9 Å, but changed the space group of the crystals from P2 1 2 1 2 to P2 1 . Because it binds soluble forms of proteins with disease-associated polyglutamine expansions, the antibody 3B5H10 is a powerful tool for studying polyglutamine-related diseases. Crystals of the 3B5H10 Fab (47 kDa) were obtained by vapor diffusion at room temperature from PEG 3350. However, the initial crystals gave highly anisotropic diffraction patterns. After optimization of the crystallization conditions and cryoprotectants, a nearly isotropic diffraction pattern at 2.6 Å resolution was achieved for crystals with unit-cell parameters a = 133.26, b = 79.52, c = 41.49 Å and space group P2 1 2 1 2. Dehydrated crystals diffracted isotropically to 1.9 Å with unit-cell parameters a = 123.65, b = 78.25, c = 42.26 Å, β = 90.3° and space group P2 1

  4. Crystallization and diffraction properties of the Fab fragment of 3B5H10, an antibody specific for disease-causing polyglutamine stretches

    Energy Technology Data Exchange (ETDEWEB)

    Peters-Libeu, Clare; Newhouse, Yvonne; Krishnan, Preethi; Cheung, Kenneth; Brooks, Elizabeth [Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 (United States); Weisgraber, Karl [Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 (United States); Department of Pathology, University of California, San Francisco, CA 94143 (United States); Finkbeiner, Steven, E-mail: sfinkbeiner@gladstone.ucsf.edu [Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 (United States); Departments of Neurology, Physiology and Neuroscience and Biomedical Sciences Program, University of California, San Francisco, CA 94143 (United States)

    2005-12-01

    Optimization of crystallization conditions and cryoprotectants decreased the anisotropy of the diffraction obtained from 3B5H10 Fab crystals. Dehydration improved the resolution of cryoprotected 3B5H10 crystals from 2.6 to 1.9 Å, but changed the space group of the crystals from P2{sub 1}2{sub 1}2 to P2{sub 1}. Because it binds soluble forms of proteins with disease-associated polyglutamine expansions, the antibody 3B5H10 is a powerful tool for studying polyglutamine-related diseases. Crystals of the 3B5H10 Fab (47 kDa) were obtained by vapor diffusion at room temperature from PEG 3350. However, the initial crystals gave highly anisotropic diffraction patterns. After optimization of the crystallization conditions and cryoprotectants, a nearly isotropic diffraction pattern at 2.6 Å resolution was achieved for crystals with unit-cell parameters a = 133.26, b = 79.52, c = 41.49 Å and space group P2{sub 1}2{sub 1}2. Dehydrated crystals diffracted isotropically to 1.9 Å with unit-cell parameters a = 123.65, b = 78.25, c = 42.26 Å, β = 90.3° and space group P2{sub 1}.

  5. Radiolabeled antibody imaging

    International Nuclear Information System (INIS)

    Wahl, R.L.

    1987-01-01

    Radiolabeled antibodies, in particular monoclonal antibodies, offer the potential for the specific nuclear imaging of malignant and benign diseases in man. If this imaging potential is realized, they may also have a large role in cancer treatment. This paper reviews: (1) what monoclonal antibodies are and how they differ from polyclonal antibodies, (2) how they are produced and radiolabeled, (3) the results of preclinical and clinical trials in cancer imaging, including the utility of SPECT and antibody fragments, (4) the role of antibodies in the diagnosis of benign diseases, (5) alternate routes of antibody delivery, (6) the role of these agents in therapy, and (7) whether this technology ''revolutionizes'' the practice of nuclear radiology, or has a more limited complementary role in the imaging department

  6. Encendiendo una Llama. Bilingual Gifted and Talented Program: Overview, Identification of Students, and Instructional Approaches.

    Science.gov (United States)

    Hartford Public Schools, CT.

    Three pamphlets describe facets of "Encendiendo Una Llama," a Hartford (Connecticut) demonstration program for bilingual gifted and talented students. An overview pamphlet summarizes key aspects of the model program: identification procedures, instructional services, teacher training, parent involvement, evidence of effectiveness, implementation…

  7. Year One Evaluation of "Encendiendo Una Llama" Bilingual Gifted and Talented Program. Report 80-12.

    Science.gov (United States)

    Barstow, Daniel; Roby, Wallace R.

    The document reports activities of "Encendiendo Una Llama," a bilingual gifted and talented program serving 60 students in grades K through 6 in a school day resource room component or in an after school program. Twelve program objectives are outlined in terms of proposed activities, proposed evaluation, actual results, and…

  8. Identification of cattle, llama and horse meat by near infrared reflectance or transflectance spectroscopy.

    Science.gov (United States)

    Mamani-Linares, L W; Gallo, C; Alomar, D

    2012-02-01

    Visible and near infrared reflectance spectroscopy (VIS-NIRS) was used to discriminate meat and meat juices from three livestock species. In a first trial, samples of Longissimus lumborum muscle, corresponding to beef (31) llamas (21) and horses (27), were homogenised and their spectra collected in reflectance (NIRSystems 6500 scanning monochromator, in the range of 400-2500 nm). In the second trial, samples of meat juice (same muscle) from the same species (20 beef, 19 llama and 19 horse) were scanned in folded transmission (transflectance). Discriminating models (PLS regression) were developed against "dummy" variables, testing different mathematical treatments of the spectra. Best models indentified the species of almost all samples by their meat (reflectance) or meat juice (transflectance) spectra. A few (three of beef and one of llama, for meat samples; one of beef and one of horse, for juice samples) were classified as uncertain. It is concluded that NIRS is an effective tool to recognise meat and meat juice from beef, llama and horses. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. The Adventures of Artemis and the Llama: A Case for Imaginary Histories in Art Education

    Science.gov (United States)

    Vallance, Elizabeth

    2004-01-01

    Artemis is a late Hellenistic Greek marble sculpture of the huntress, running in a flowing garment, now lacking arms, legs, and head, and about three-quarters life-sized. The llama is a remarkable hollow male figure of smooth thin gold, and about two inches tall, and was made by the Inca before the Spanish conquest in 1532. This narrative is just…

  10. Genotypic characterization of Chilean llama (Lama glama) and alpaca (Vicugna pacos) pestivirus isolates.

    Science.gov (United States)

    Aguirre, I M; Fuentes, R; Celedón, M O

    2014-01-31

    Llamas and alpacas are domesticated South American camelids (SACs) important to ancestral population in the Altiplano region, and to different communities worldwide where they have been introduced. These ungulates have shown to be susceptible to several livestock viral pathogens such as members of the Pestivirus genus, in particular Bovine Viral Diarrhea (BVDV), but there is little data available on Pestivirus infections in SACs. In this study we aimed to detect and identify Pestivirus genotypes and subgroups infecting SACs in both wild and confined environments. Samples were collected from 136 llamas and 30 alpacas from different areas in the Chilean Altiplano (wild animals), and from 22 llamas and 26 alpacas diagnosed as Pestivirus positive from the Metropolitana region in Chile (confined animals). Seroneutralization tests showed titers lower than 2 in all 166 samples from Chilean Altiplano. These samples were also negative to BVDV isolation, indicating that these animals have not been exposed to Pestivirus. After reactivation of positive samples from the Metropolitana region, the 5' non-codifying region (5'NCR) and E2 glycoprotein were amplified by RT-PCR from the Pestivirus genome. Viral sequences were pairwise compared and phylogenetic trees were constructed. The 5'NCR analysis showed that all 12 sequenced isolates belonged to BVDV-1. Of particular interest, isolates from eight llama and two alpaca were BVDV-1j and two alpacas were BVDV-1b. In agreement with these results, E2 phylogenetic analysis rendered a similar grouping indicating that all 16 isolates belong to BVDV-1. However, the lower availability of E2 sequences determines the creation of a smaller number of sub-groups than the 5'NCR sequences. Based on the E2 sequences, the 5'NCR BVDV 1j group consisting of all the llamas and 3 alpacas are completely included in the E2 BVDV 1e group. Due to the universal availability of the 5'NCR segment, we propose the classification of these Chilean llamas and

  11. Nuclear fragmentation

    International Nuclear Information System (INIS)

    Chung, K.C.

    1989-01-01

    An introduction to nuclear fragmentation, with emphasis in percolation ideas, is presented. The main theoretical models are discussed and as an application, the uniform expansion approximation is presented and the statistical multifragmentation model is used to calculate the fragment energy spectra. (L.C.)

  12. Ablation of human colon carcinoma in nude mice by 131I-labeled monoclonal anti-carcinoembryonic antigen antibody F(ab')2 fragments

    International Nuclear Information System (INIS)

    Buchegger, F.; Pfister, C.; Fournier, K.; Prevel, F.; Schreyer, M.; Carrel, S.; Mach, J.P.

    1989-01-01

    Pooled F(ab')2 fragments of three MAbs against distinct epitopes of carcinoembryonic antigen (CEA) were used for radioimmunotherapy of nude mice bearing a subcutaneous human colon carcinoma xenograft. 9-10 d after transplantation when tumor nodules were in exponential growth, 36 mice were treated by intravenous injection of different amounts of 131 I-labeled MAb F(ab')2. All 14 mice injected with a single dose of 2,200 (n = 10) or 2,800 microCi (n = 4) showed complete tumor remission. 8 of the 10 mice treated with 2,200 microCi survived in good health for 1 yr when they were killed and shown to be tumor free. Four of nine other mice treated with four fractionated doses of 400 microCi showed no tumor relapse for more than 9 mo. In contrast, all 15 mice injected with 1,600-3,000 microCi 131 I-control IgG F(ab')2 showed tumor growth retardation of only 1-4 wk, and 15 of 16 mice injected with unlabeled anti-CEA MAb F(ab')2 showed unmodified tumor progression as compared with untreated mice. From tissue radioactivity distributions it was calculated that by an injection of 2,200 microCi 131 I-MAb F(ab')2 a mean dose of 8,335 rad was selectively delivered to the tumor, while the tissue-absorbed radiation doses for the normal organs were: peripheral blood, 2,093; stomach, 1,668; kidney, 1,289; lung, 1,185; liver, 617; spleen, 501; small intestine, 427; large intestine, 367; bone, 337; and muscle, 198. These treatments were well tolerated since out of 19 mice with complete tumor remission only 4 required bone marrow transplantation and 17 were in good health for 6-12 mo of observation

  13. Monoclonal antibody OKB7, which identifies the 14OKd complement receptor type 2 (CR/sub 2/), also identifies a 72Kd secreted fragment of CR/sub 2/ that contains the C3d-binding site

    Energy Technology Data Exchange (ETDEWEB)

    Myones, B.L.; Ross, G.D.

    1986-03-05

    CR/sub 2/ is a 140-145Kd glycoprotein expressed on B lymphocytes which binds both C3d and Epstein-Barr virus (EBV). OKB7, an IgG/sub 2a/ monoclonal antibody to CR/sub 2/, blocks C3d and EBV binding, while HB-5, another monoclonal IgG/sub 2a/ anti-CR/sub 2/, does not. A 72Kd C3d-binding glycoprotein (gp72), isolated from Raji cell media, was previously thought to be CR/sub 2/ because a polyclonal rabbit anti-gp72 inhibited EC3d rosettes. ELISA assay demonstrated that OKB7, but not HB-5, bound to purified gp72 fixed to microtiter wells. Insoluble and soluble gp72 blocked Raji cell uptake of /sup 125/I-labeled OKB7, but not labeled anti-B2 or HB-5. Rabbit anti-gp72 immunoprecipitated bands at 140Kd and 72Kd from /sup 125/I-labelled and solubilized B cell membranes. Culture media from Raji cells grown in the presence /sup 3/H-labeled amino acids was sequentially immunoprecipitated by irrelevant antibody, OKB7, and HB-5. A single 72Kd radiolabeled band was demonstrated only with OKB7, and this was identical to that produced by the immunoprecipitation of /sup 125/I-labeled gp72 with rabbit anti-gp72. Thus, OKB7, which identifies the 140Kd CR/sub 2/ molecule, also identifies a 72Kd shed fragment of CR/sub 2/ isolated from Raji cell media, which contains the C3d-binding site.

  14. Monoclonal antibody OKB7, which identifies the 14OKd complement receptor type 2 (CR2), also identifies a 72Kd secreted fragment of CR2 that contains the C3d-binding site

    International Nuclear Information System (INIS)

    Myones, B.L.; Ross, G.D.

    1986-01-01

    CR 2 is a 140-145Kd glycoprotein expressed on B lymphocytes which binds both C3d and Epstein-Barr virus (EBV). OKB7, an IgG/sub 2a/ monoclonal antibody to CR 2 , blocks C3d and EBV binding, while HB-5, another monoclonal IgG/sub 2a/ anti-CR 2 , does not. A 72Kd C3d-binding glycoprotein (gp72), isolated from Raji cell media, was previously thought to be CR 2 because a polyclonal rabbit anti-gp72 inhibited EC3d rosettes. ELISA assay demonstrated that OKB7, but not HB-5, bound to purified gp72 fixed to microtiter wells. Insoluble and soluble gp72 blocked Raji cell uptake of 125 I-labeled OKB7, but not labeled anti-B2 or HB-5. Rabbit anti-gp72 immunoprecipitated bands at 140Kd and 72Kd from 125 I-labelled and solubilized B cell membranes. Culture media from Raji cells grown in the presence 3 H-labeled amino acids was sequentially immunoprecipitated by irrelevant antibody, OKB7, and HB-5. A single 72Kd radiolabeled band was demonstrated only with OKB7, and this was identical to that produced by the immunoprecipitation of 125 I-labeled gp72 with rabbit anti-gp72. Thus, OKB7, which identifies the 140Kd CR 2 molecule, also identifies a 72Kd shed fragment of CR 2 isolated from Raji cell media, which contains the C3d-binding site

  15. Production of a phage-displayed single chain variable fragment ...

    African Journals Online (AJOL)

    Abstract. Purpose: To develop specific single chain variable fragments (scFv) against ... libraries. The binding ability of the selected scFv antibody fragments against the IBDV particles was ..... Hermelink H, Koscielniak E. A human recombinant.

  16. Effect of Polysorbate 20 and Polysorbate 80 on the Higher-Order Structure of a Monoclonal Antibody and Its Fab and Fc Fragments Probed Using 2D Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Singh, Surinder M; Bandi, Swati; Jones, David N M; Mallela, Krishna M G

    2017-12-01

    We examined how polysorbate 20 (PS20; Tween 20) and polysorbate 80 (PS80; Tween 80) affect the higher-order structure of a monoclonal antibody (mAb) and its antigen-binding (Fab) and crystallizable (Fc) fragments, using near-UV circular dichroism and 2D nuclear magnetic resonance (NMR). Both polysorbates bind to the mAb with submillimolar affinity. Binding causes significant changes in the tertiary structure of mAb with no changes in its secondary structure. 2D 13 C- 1 H methyl NMR indicates that with increasing concentration of polysorbates, the Fab region showed a decrease in crosspeak volumes. In addition to volume changes, PS20 caused significant changes in the chemical shifts compared to no changes in the case of PS80. No such changes in crosspeak volumes or chemical shifts were observed in the case of Fc region, indicating that polysorbates predominantly affect the Fab region compared to the Fc region. This differential effect of polysorbates on the Fab and Fc regions was because of the lesser thermodynamic stability of the Fab compared to the Fc. These results further indicate that PS80 is the preferred polysorbate for this mAb formulation, because it offers higher protection against aggregation, causes lesser structural perturbation, and has weaker binding affinity with fewer binding sites compared to PS20. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  17. Controlled fragmentation

    International Nuclear Information System (INIS)

    Arnold, Werner

    2002-01-01

    Contrary to natural fragmentation, controlled fragmentation offers the possibility to adapt fragment parameters like size and mass to the performance requirements in a very flexible way. Known mechanisms like grooves inside the casing, weaken the structure. This is, however, excluded for applications with high accelerations during launch or piercing requirements for example on a semi armor piercing penetrator. Another method to achieve controlled fragmentation with an additional grid layer is presented with which the required grooves are produced 'just in time' inside the casing during detonation of the high explosive. The process of generating the grooves aided by the grid layer was studied using the hydrocode HULL with respect to varying grid designs and material combinations. Subsequent to this, a large range of these theoretically investigated combinations was contemplated in substantial experimental tests. With an optimised grid design and a suitable material selection, the controlled fragment admits a very flexible adaptation to the set requirements. Additional advantages like the increase of perforation performance or incendiary amplification can be realized with the grid layer

  18. Ambigüedad y justicia en El Llano en llamas de Juan Rulfo

    Directory of Open Access Journals (Sweden)

    Goldgel Carballo, Víctor

    2007-04-01

    Full Text Available In El llano en llamas, the multiplication of points of view and narrative voices bring about a reflection on the potentialities and dangers of ambiguous meaning. By appealing to a multiperspectivism that emphasizes discontinuity, Rulfo invite us to examine the violence inherent to the encounter between different voices, and upon the ways in which the coercion and silencing of the other support the construction of hegemonic meaning.En El llano en llamas la multiplicación de puntos de vista propicia una reflexión sobre las potencialidades y los peligros de un sentido ambiguo. Mediante un multiperspectivismo que enfatiza lo discontinuo, Rulfo nos invita a meditar acerca de la violencia inherente al encuentro entre diferentes y acerca de los modos en que la coerción y el silenciamiento del otro funcionan como pilares en la construcción de sentidos hegemónicos.

  19. Fracture repair with transfixation pins and fiberglass cast in llamas and small ruminants.

    Science.gov (United States)

    Kaneps, A J; Schmotzer, W B; Huber, M J; Riebold, T W; Watrous, B J; Arnold, J S

    1989-11-01

    Transfixation pinning with fiberglass casting is an effective and adaptable method of longbone fracture fixation in llamas and small ruminants. Treatment of fractures in 7 limbs of 4 llamas and 2 small ruminants with this technique are described. Steinmann pins are placed transcortically proximal, and if necessary, distal to the fracture. The pin ends and limb are encased in fiberglass cast material. The cast is strong enough in animals of this size to eliminate the need for external frames or connecting bars. Severely comminuted fractures and fractures near joints are especially suited to fixation with this technique. Complications encountered in these cases included loosening of pins and one delayed union. All fractures healed to permit full use of the limb.

  20. Diminished renal urea excretion in the llama at reduced food intake

    International Nuclear Information System (INIS)

    Engelhardt, W.; Engelhardt, W. von

    1976-01-01

    Renal urea excretion was studied in three llamas under various feeding conditions. Glomerular filtration rate (GFR) was estimated from inulin clearance. Tubular reabsorbed urea was the difference between glomerular filtered and renal excreted urea. Plasma urea concentration increased significantly when feeding was reduced by 40% and 60%, not applicable to a straw diet. With reduced hay feeding and on a straw diet only a slight and insignificant decrease was observed in renal urea excretion, with only a 3% lowering in GFR and glomerular filtered urea. With a straw diet, the glomerular filtered urea was significantly below the controls. The fraction of filtered urea reabsorbed in the tubules was constant (36%-47%). Very high reabsorption (87%) on a supplemented straw dietwas observed in one llama which after nearly 6 months on this low protein diet - could be shown to have lost only 5% of its body weight

  1. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  2. Chameleon fragmentation

    International Nuclear Information System (INIS)

    Brax, Philippe; Upadhye, Amol

    2014-01-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ 4 and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments

  3. Oriented conjugates of monoclonal and single-domain antibodies with quantum dots for flow cytometry and immunohistochemistry diagnostic applications

    Science.gov (United States)

    Sukhanova, Alyona; Even-Desrumeaux, Klervi; Millot, Jean-Marc; Chames, Patrick; Baty, Daniel; Artemyev, Mikhail; Oleinikov, Vladimir; Cohen, Jacques H. M.; Nabiev, Igor

    2012-03-01

    Ideal diagnostic nanoprobes should not exceed 15 nm in size and should contain high-affinity homogeneously oriented capture molecules on their surface. An advanced procedure for antibody (Ab) reduction was used to cleave each Ab into two functional half-Abs, 75-kDa heavy-light chain fragments, each containing an intact antigen-binding site. Affinity purification of half-Abs followed by their linkage to quantum dots (QDs) yielded oriented QD-Ab conjugates whose functionality was considerably improved compared to those obtained using the standard protocols. Ultrasmall diagnostic nanoprobes were engineered through oriented conjugation of QDs with 13-kDa single-domain Abs (sdAbs) derived from llama IgG. sdAbs were tagged with QDs via an additional cysteine residue specifically integrated into the C-terminal region of sdAb using genetic engineering. This approach made it possible to obtain sdAb-QD nanoprobes <12 nm in diameter comprising four copies of sdAbs linked to the same QD in an oriented manner. sdAb-QD conjugates against carcinoembryonic antigen (CEA) and HER2 exhibited an extremely high specificity in flow cytometry; the quality of immunohistochemical labeling of biopsy samples was found to be superior to that of labeling according to the current "gold standard" protocols of anatomo-pathological practice. The nano-bioengineering approaches developed can be extended to oriented conjugation of Abs and sdAbs with different semiconductor, noble metal, or magnetic nanoparticles.

  4. Molecular detection of Sarcocystis aucheniae in the blood of llamas from Argentina.

    Science.gov (United States)

    Martin, Mara; Decker Franco, Cecilia; Romero, Sandra; Carletti, Tamara; Schnittger, Leonhard; Florin-Christensen, Monica

    Sarcocystis aucheniae are apicomplexan protozoa that infect South American camelids (SACs), giving rise to macroscopic cysts similar to rice grains in skeletal muscles. Visual detection of macrocysts in slaughtered animals hampers commercialization of SAC meat, a highly relevant economic exploitation for Andean rural families. Importantly, the consumption of undercooked S. aucheniae-infested meat causes gastroenteritis. A carnivore definitive host, possibly the dog, acquires the parasite when feeding on infected SAC meat, and later eliminates infective oocysts in its feces. The parasite cycle is completed when SACs ingest contaminated water or pastures. We hypothesized that parasite DNA can be detected in SAC blood using molecular methods. In order to test this hypothesis, a seminested PCR format was specifically designed to target the hypervariable 18S rRNA gene region of S. aucheniae. PCR conditions were optimized using genomic DNA extracted from macrocyst bradyzoites. A detection limit of up to 1 parasite in 10μl of llama blood was established based on DNA samples extracted from aliquots of S. aucheniae bradyzoite-spiked non-infected llama blood. The seminested PCR allowed to detect natural infections of S. aucheniae in llama blood samples originating in the Andean flatlands of Argentina. Specific amplification of S. aucheniae DNA was corroborated by amplicon sequencing. This is the first report of S. aucheniae detection in llama blood, which provides a valuable diagnostic tool for epidemiological studies and for the evaluation of the efficacy of control measures for this parasitosis. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Upper airway obstruction in a llama caused by aberrant nasopharyngeal bots (Cephenemyia sp.)

    International Nuclear Information System (INIS)

    Mattoon, J.S.; Gerros, T.C.; Parker, J.E.; Carter, C.A.; LaMarche, R.M.

    1997-01-01

    A 9 month old female llama was presented with inspiratory dyspnea. Radiographically, there was a large soft tissue mass nearly occluding the nasopharynx. During endoscopic examination three nasopharyngeal bots were identified embedded in the mass. The larvae were removed and the patient treated with ivermectin. The patient was discharged one week later free of clinical respiratory disease. In follow-up radiographs made 6 weeks later, only residual radiopacity in the area of the mass remained

  6. Diminished renal urea excretion in the llama at reduced food intake

    International Nuclear Information System (INIS)

    Engelhardt, W.; Engelhardt, W. von

    1976-01-01

    At a low protein low-energy diet or during reduced food intake, the glomerular filtration rate and thereby the glomerular filtered urea was reduced by about 30%. During most experiments tubular reabsorption of filtered urea was rather constant (averaging 43%). A high reabsorption of 87% was observed in one llama for several weeks during a straw diet with moderate supplementation of some carbohydrates. (author)

  7. LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies

    Science.gov (United States)

    Rosario, D. J.; Burtscher, L.; Davies, R. I.; Koss, M.; Ricci, C.; Lutz, D.; Riffel, R.; Alexander, D. M.; Genzel, R.; Hicks, E. H.; Lin, M.-Y.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry, G.; Riffel, R. A.; Schartmann, M.; Schawinski, K.; Schnorr-Müller, A.; Saintonge, A.; Shimizu, T.; Sternberg, A.; Storchi-Bergmann, T.; Sturm, E.; Tacconi, L.; Treister, E.; Veilleux, S.

    2018-02-01

    Using new Atacama Pathfinder Experiment and James Clerk Maxwell Telescope spectroscopy of the CO 2→1 line, we undertake a controlled study of cold molecular gas in moderately luminous (Lbol = 1043-44.5 erg s-1) active galactic nuclei (AGN) and inactive galaxies from the Luminous Local AGN with Matched Analogs (LLAMA) survey. We use spatially resolved infrared photometry of the LLAMA galaxies from 2MASS, the Wide-field Infrared Survey Explorer the Infrared Astronomical Satellite and the Herschel Space Observatory (Herschel), corrected for nuclear emission using multicomponent spectral energy distribution fits, to examine the dust-reprocessed star formation rates, molecular gas fractions and star formation efficiencies (SFEs) over their central 1-3 kpc. We find that the gas fractions and central SFEs of both active and inactive galaxies are similar when controlling for host stellar mass and morphology (Hubble type). The equivalent central molecular gas depletion times are consistent with the discs of normal spiral galaxies in the local Universe. Despite energetic arguments that the AGN in LLAMA should be capable of disrupting the observable cold molecular gas in their central environments, our results indicate that nuclear radiation only couples weakly with this phase. We find a mild preference for obscured AGN to contain higher amounts of central molecular gas, which suggests connection between AGN obscuration and the gaseous environment of the nucleus. Systems with depressed SFEs are not found among the LLAMA AGN. We speculate that the processes that sustain the collapse of molecular gas into dense pre-stellar cores may also be a prerequisite for the inflow of material on to AGN accretion discs.

  8. Macroscopic anatomy, irrigation and venous drainage of female reproductive apparatus of llama (Lama glama)

    OpenAIRE

    León M., Eric; Sato S., Alberto; Navarrete Z., Miluska; Cisneros S., Jannet

    2011-01-01

    The anatomical description of the reproductive tract of the female llama was studied in four animals. Macroscopically, the reproductive system is morphologically similar to the cow. However, the difference is the absence of intercornual ligament and cotyledons, and the presence of an intercornual septum, as in the alpaca. The distribution of the arteries and veins that irrigated and drained the blood to and from the pelvic cavity and reproductive system presented a vascular distribution almos...

  9. Prevalence of Mycoplasma haemolamae infection in Peruvian and Chilean llamas and alpacas.

    Science.gov (United States)

    Tornquist, Susan J; Boeder, Lisa; Rios-Phillips, Carolina; Alarcon, Virgilio

    2010-09-01

    Mycoplasma haemolamae is a hemotropic mycoplasma that affects red blood cells of llamas (Lama glama) and alpacas (Lama pacos). It is variably associated with anemia, and most infections are subclinical. Development of a polymerase chain reaction assay has facilitated detection of this infection in llamas and alpacas in the United States and other countries. Whether the infection occurs in camelids in South America has previously been unknown. The current study documents a 15.8% infection rate among 76 Peruvian llamas, a 19.3% infection rate among Peruvian alpacas at one site, and a 9.26% infection rate in 108 Chilean alpacas from selected herds. All of the camelids tested appeared to be clinically healthy. No gender or species predilection was found. Only 1 positive camelid younger than 18 months was found. Infection is not associated with anemia, and the mean packed cell volume (PCV) in positive Peruvian camelids was slightly higher than the mean PCV in negative Peruvian camelids. In the Chilean alpacas, the positive alpacas had a slightly lower PCV than the negative alpacas, although the mean PCV was not in the anemic range in any of the groups.

  10. Hepatic lipidosis in llamas and alpacas: 31 cases (1991-1997).

    Science.gov (United States)

    Tornquist, S J; Van Saun, R J; Smith, B B; Cebra, C K; Snyder, S P

    1999-05-01

    To identify factors associated with hepatic lipidosis (HL) in llamas and alpacas. Retrospective case series. 30 llamas and 1 alpaca. Medical records were searched to identify llamas or alpacas in which a histologic diagnosis of HL was made. Information was retrieved on signalment, history, clinical and laboratory findings, and results of necropsy or examination of biopsy specimens. Data were analyzed using descriptive statistics and chi 2 analyses. Females were affected more often than males; however, the sex distribution was not different from that of the camelid population in the diagnostic laboratory's database. Fifty-four percent of the females were pregnant, and 46% were lactating. Most affected camelids were 6 to 10 years old. Anorexia and recent weight loss were common (51.6% of camelids). An infective agent was found in only one ilama, and toxins and mineral deficiencies were not identified. The most common abnormalities on serum biochemical analysis were a high concentration of bile acids, high activities of gamma-glutamyltransferase (GGT) and aspartate aminotransferase (AST), and hypoproteinemia. Concentrations of nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (beta-HB) were high in those camelids in which these compounds were assayed. Twenty-nine camelids did not survive. Sick camelids should be considered at risk for developing HL, especially those with anorexia or the metabolic demands of pregnancy and lactation. Other stresses also appear to contribute. High concentrations of NEFA, beta-HB, and bile acids; high activities of GGT and AST; and hypoproteinemia may indicate that HL has developed.

  11. 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.

  12. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2017-01-01

    The PhD project Bespoke Fragments is investigating the space emerging in the exploration of the relationship between digital drawing and fabrication, and the field of materials and their properties and capacities. Through a series of different experiments, the project situates itself in a shuttli...

  13. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  14. Use of focused acoustics for cell disruption to provide ultra scale-down insights of microbial homogenization and its bioprocess impact--recovery of antibody fragments from rec E. coli.

    Science.gov (United States)

    Li, Qiang; Aucamp, Jean P; Tang, Alison; Chatel, Alex; Hoare, Mike

    2012-08-01

    An ultra scale-down (USD) device that provides insight of how industrial homogenization impacts bioprocess performance is desirable in the biopharmaceutical industry, especially at the early stage of process development where only a small quantity of material is available. In this work, we assess the effectiveness of focused acoustics as the basis of an USD cell disruption method to mimic and study high-pressure, step-wise homogenization of rec Escherichia coli cells for the recovery of an intracellular protein, antibody fragment (Fab'). The release of both Fab' and of overall protein follows first-order reaction kinetics with respect to time of exposure to focused acoustics. The rate constant is directly proportional to applied electrical power input per unit volume. For nearly total protein or Fab' release (>99%), the key physical properties of the disruptate produced by focused acoustics, such as cell debris particle size distribution and apparent viscosity show good agreement with those for homogenates produced by high-pressure homogenization operated to give the same fractional release. The only key difference is observed for partial disruption of cells where focused acoustics yields a disruptate of lower viscosity than homogenization, evidently due to a greater extent of polynucleic acids degradation. Verification of this USD approach to cell disruption by high-pressure homogenization is achieved using USD centrifugation to demonstrate the same sedimentation characteristics of disruptates prepared using both the scaled-down focused acoustic and the pilot-scale homogenization methods for the same fraction of protein release. Copyright © 2012 Wiley Periodicals, Inc.

  15. Sistemática, taxonomía y domesticación de alpacas y llamas: nueva evidencia cromosómica y molecular Systematics, taxonomy and domestication of alpaca and llama: new chromosomal and molecular evidence

    Directory of Open Access Journals (Sweden)

    JUAN C MARÍN

    2007-06-01

    Full Text Available Existen cuatro especies de camélidos sudamericanos, dos de ellos silvestres, guanaco (Lama guanicoe y vicuña (Vicugna vicugna, y dos formas domésticas, alpaca (Lama pacos y llama (Lama glama, cuyo origen ha sido objeto de debate. En el presente estudio la variación en el patrón de bandas G de los cromosomas de llamas y alpacas y la secuencia de dos genes mitocondriales han sido usados para estudiar el origen y la clasificación de llamas y alpacas. Patrones de bandas cromosómicas similares fueron observados en las cuatro especies de Lamini, incluso similares a los descritos para camello, Camelus bactrianus. Sin embargo, se encontraron finas y consistentes diferencias en los brazos cortos del cromosoma 1, permitiendo separar a camellos, guanacos y llamas, de las de vicuñas y alpacas. Este patrón fue consistente incluso en un híbrido guanaco x alpaca. Relaciones equivalentes fueron encontradas en las secuencias completas del gen para citocromo b, así como en el árbol de expansión mínima de las secuencias parciales de la región control, agrupando a guanacos con llamas y a vicuñas con alpacas. Los análisis filogenéticos mostraron a V. vicugna y a L. guanicoe como grupos recíprocamente monofHéticos. El análisis de las secuencias de ambos genes mostró dos ciados entre las vicuñas, concordantes con las subespecies reconocidas para esta especie, pero los resultados obtenidos para guanacos no reflejaron la existencia de las cuatro subespecies previamente propuestas. El análisis combinado de variaciones cromosómicas y moleculares demostraron una alta similitud genética entre alpacas y vicuñas, así como entre llamas y guanacos. Aunque se revela hibridización direccional, nuestros resultados apoyan fuertemente la hipótesis de que la llama se deriva de L. guanicoe, y la alpaca de V. vicugna, apoyando la reclasificación de la alpaca como V. pacosFour camelid species exist in South America: two wild, the guanaco (Lama guanicoe and

  16. Architectural fragments

    DEFF Research Database (Denmark)

    Bang, Jacob Sebastian

    2018-01-01

    I have created a large collection of plaster models: a collection of Obstructions, errors and opportunities that may develop into architecture. The models are fragments of different complex shapes as well as more simple circular models with different profiling and diameters. In this contect I have....... I try to invent the ways of drawing the models - that decode and unfold them into architectural fragments- into future buildings or constructions in the landscape. [1] Luigi Moretti: Italian architect, 1907 - 1973 [2] Man Ray: American artist, 1890 - 1976. in 2015, I saw the wonderful exhibition...... "Man Ray - Human Equations" at the Glyptotek in Copenhagen, organized by the Philips Collection in Washington D.C. and the Israel Museum in Jerusalem (in 2013). See also: "Man Ray - Human Equations" catalogue published by Hatje Cantz Verlag, Germany, 2014....

  17. A stably expressed llama single-domain intrabody targeting Rev displays broad-spectrum anti-HIV activity.

    Science.gov (United States)

    Boons, Eline; Li, Guangdi; Vanstreels, Els; Vercruysse, Thomas; Pannecouque, Christophe; Vandamme, Anne-Mieke; Daelemans, Dirk

    2014-12-01

    The HIV Rev protein mediates the transport of partially and unspliced HIV mRNA from the nucleus to the cytoplasm. Rev multimerizes on a secondary stem-loop structure present in the viral intron-containing mRNA species and recruits the cellular karyopherin CRM1 to export viral mRNAs from the nucleus to the cytoplasm. Previously we have identified a single-domain intrabody (Nb(190)), derived from a llama heavy-chain antibody, which efficiently inhibits Rev multimerization and suppresses the production of infectious virus. We recently mapped the epitope of this nanobody and demonstrated that Rev residues K20 and Y23 are crucial for interaction while residues V16, H53 and L60 are important to a lesser extent. Here, we generated cell lines stably expressing Nb(190) and assessed the capacity of these cell lines to suppress the replication of different HIV-1 subtypes. These cells stably expressing the single-domain antibody are protected from virus-induced cytopathogenic effect even in the context of high multiplicity of infection. In addition, the replication of different subtypes of group M and one strain of group O is significantly suppressed in these cell lines. Next, we analysed the natural variations of Rev amino acids in sequence samples from HIV-1 infected patients worldwide and assessed the effect of Nb(190) on the most prevalent polymorphisms occurring at the key epitope positions (K20 and Y23) in Rev. We found that Nb(190) was able to suppress the function of these Rev variants except for the K20N mutant, which was present in only 0.7% of HIV-1 sequence populations (n = 4632). Cells stably expressing the single-domain intrabody Nb(190) are protected against virus-induced cytopathogenic effect and display a selective survival advantage upon infection. In addition, Nb(190) suppresses the replication of a wide range of different HIV-1 subtypes. Large-scale sequence analysis reveals that the Nb(190) epitope positions in Rev are well conserved across major HIV-1

  18. Intermediate Fragment

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

  19. Fragmentation based

    Directory of Open Access Journals (Sweden)

    Shashank Srivastava

    2014-01-01

    Gaining the understanding of mobile agent architecture and the security concerns, in this paper, we proposed a security protocol which addresses security with mitigated computational cost. The protocol is a combination of self decryption, co-operation and obfuscation technique. To circumvent the risk of malicious code execution in attacking environment, we have proposed fragmentation based encryption technique. Our encryption technique suits the general mobile agent size and provides hard and thorny obfuscation increasing attacker’s challenge on the same plane providing better performance with respect to computational cost as compared to existing AES encryption.

  20. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2016-01-01

    , investigating levels of control and uncertainty encountering with these. Through tangible experiments, the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect's digital drawing and workflow. The project sees this expansion as an opportunity to connect...... architectural designs, tectonics and aesthetics. In this Ph.D.-project a series a physical, but conceptual, experiment plays the central role in the knowledge production. The experiments result in materialised architectural fragments and tangible experiences. However, these creations also become the driving...

  1. Expression of recombinant Antibodies

    Directory of Open Access Journals (Sweden)

    André eFrenzel

    2013-07-01

    Full Text Available Recombinant antibodies are highly specific detection probes in research, diagnostics and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines and transgenic plants are promising to obtain antibodies with human-like post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications.

  2. Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF) present in llama seminal plasma.

    Science.gov (United States)

    Silva, Mauricio E; Smulders, Juan P; Guerra, Monserrat; Valderrama, Ximena P; Letelier, Claudia; Adams, Gregg P; Ratto, Marcelo H

    2011-05-30

    The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group) and a) pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate) followed by 1 mg of purified llama OIF, b) pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c) pre-treated with a placebo (2 ml of saline) followed by 1 mg of purified llama OIF or d) pre-treated with a placebo (2 ml of saline) followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment) to Day 16. Ovulation rate was not different (P = 0.89) between placebo+GnRH (86%) and placebo+OIF groups (100%); however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

  3. Embryo yield in llamas synchronized with two different intravaginal progesterone-releasing devices and superovulated with eCG

    Directory of Open Access Journals (Sweden)

    Juan F. Aller

    2015-09-01

    Full Text Available The objectives of this study were to compare the effects of two intravaginal devices (ID containing the same dose (0.5 g of progesterone (P4 on subsequent ovarian response, embryo production and circulating P4 concentration profile in llamas (Lama glama treated with equine chorionic gonadotropin (eCG for ovarian superstimulation. Female llamas were randomly assigned (n = 10 llamas per group to one of the following groups and treated (Day 0 with an ID containing 0.5 g of vegetal P4 to synchronize the emergence of a new follicular wave: i DIB 0.5® and ii Cronipres M15®. On Day 3 llamas were intramuscularly treated with 1000 IU of eCG. The IDs were removed on Day 7. Llamas were naturally mated (Day 9 and treated with GnRH analogue to induce ovulation. A second mating was allowed 24 h later. Embryos were collected between 7 and 8 days after the first mating. Blood samples were taken every day from Day 0 to Day 7 to measure circulating P4 concentrations. The results indicated that DIB device maintained greater plasma P4 levels as compared to Cronipres until Day 2. However, the mean (± SD number of corpora lutea and recovered embryos was not affected (p < 0.05 by the type of ID (5.3 ± 2.6 vs 4.2 ± 2.2 and 3.5 ± 2.7 vs 2.6 ± 3.0 for DIB and Cronipres, respectively. In conclusion, both DIB and Cronipres devices can be successfully used to synchronize the emergence of follicular wave prior to a single dose of eCG in superovulation protocol in llamas.

  4. Embryo yield in llamas synchronized with two different intravaginal progesterone-releasing devices and superovulated with eCG

    Energy Technology Data Exchange (ETDEWEB)

    Aller, J.F.; Abalos, M.C.; Acuña, F.A.; Virgili, R.; Requena, F.; Cancino, A.K.

    2015-07-01

    The objectives of this study were to compare the effects of two intravaginal devices (ID) containing the same dose (0.5 g) of progesterone (P4) on subsequent ovarian response, embryo production and circulating P4 concentration profile in llamas (Lama glama) treated with equine chorionic gonadotropin (eCG) for ovarian superstimulation. Female llamas were randomly assigned (n = 10 llamas per group) to one of the following groups and treated (Day 0) with an ID containing 0.5 g of vegetal P4 to synchronize the emergence of a new follicular wave: i) DIB 0.5® and ii) Cronipres M15®. On Day 3 llamas were intramuscularly treated with 1000 IU of eCG. The IDs were removed on Day 7. Llamas were naturally mated (Day 9) and treated with GnRH analogue to induce ovulation. A second mating was allowed 24 h later. Embryos were collected between 7 and 8 days after the first mating. Blood samples were taken every day from Day 0 to Day 7 to measure circulating P4 concentrations. The results indicated that DIB device maintained greater plasma P4 levels as compared to Cronipres until Day 2. However, the mean (± SD) number of corpora lutea and recovered embryos was not affected (p < 0.05) by the type of ID (5.3 ± 2.6 vs 4.2 ± 2.2 and 3.5 ± 2.7 vs 2.6 ± 3.0 for DIB and Cronipres, respectively). In conclusion, both DIB and Cronipres devices can be successfully used to synchronize the emergence of follicular wave prior to a single dose of eCG in superovulation protocol in llamas. (Author)

  5. Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF present in llama seminal plasma

    Directory of Open Access Journals (Sweden)

    Letelier Claudia

    2011-05-01

    Full Text Available Abstract Background The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Methods Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group and a pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate followed by 1 mg of purified llama OIF, b pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c pre-treated with a placebo (2 ml of saline followed by 1 mg of purified llama OIF or d pre-treated with a placebo (2 ml of saline followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment to Day 16. Results Ovulation rate was not different (P = 0.89 between placebo+GnRH (86% and placebo+OIF groups (100%; however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P Conclusion Cetrorelix (GnRH antagonist inhibited the preovulatory LH surge induced by OIF in llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

  6. Comparison of differents methods of sperm selection of llama raw semen.

    Science.gov (United States)

    Santa Cruz, R; Giuliano, S M; Gambarotta, M C; Morrell, J M; Abraham, M C; Miragaya, M H; Carretero, M I

    2016-10-01

    The objective of this study was to compare the efficiency of different sperm selection methods applied to the same llama ejaculate. Four treatments were compared: two variants of the swim up technique (with and without seminal plasma), and two different colloids, Androcoll-E-Large and Percoll(®). Using electroejaculation, 21 semen samples were obtained from 7 llama males (n=7, r=3). The ejaculates were incubated in a solution of 0.1% collagenase, to decrease thread formation, and then split into 4 aliquots: one aliquot was layered over a column of Androcoll-E-Large (SLC) and the second over a column of Percoll (45%). The third aliquot was deposited in a tube with culture medium and was incubated at a 45° angle for 30min at 37°C (SU1). The last aliquot was centrifuged to separate the spermatozoa and seminal plasma. The sperm pellet obtained was resuspended, and transferred to a tube with culture medium which was incubated at an angle of 45° for 30min at 37°C (SU2). Both aliquots SLC and P showed higher proportions of progressive motility and plasma membrane functionality (p≤0.05) than raw semen. There were no significant differences (p>0.05) in sperm viability and in normal spermatozoa between raw semen and treatments. Nevertheless, only SLC did not have a significant increase of bent tails. In conclusion SLC centrifugation would be the method of choice for selecting llama spermatozoa. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Molecular characterization of the llama FGF5 gene and identification of putative loss of function mutations.

    Science.gov (United States)

    Daverio, M S; Vidal-Rioja, L; Frank, E N; Di Rocco, F

    2017-12-01

    Llama, the most numerous domestic camelid in Argentina, has good fiber-production ability. Although a few genes related to other productive traits have been characterized, the molecular genetic basis of fiber growth control in camelids is still poorly understood. Fibroblast growth factor 5 (FGF5) is a secreted signaling protein that controls hair growth in humans and other mammals. Mutations in the FGF5 gene have been associated with long-hair phenotypes in several species. Here, we sequenced the llama FGF5 gene, which consists of three exons encoding 813 bp. cDNA analysis from hair follicles revealed the expression of two FGF5 alternative spliced transcripts, in one of which exon 2 is absent. DNA variation analysis showed four polymorphisms in the coding region: a synonymous SNP (c.210A>G), a single base deletion (c.348delA), a 12-bp insertion (c.351_352insCATATAACATAG) and a non-sense mutation (c.499C>T). The deletion was always found together with the insertion forming a haplotype and producing a putative truncated protein of 123 amino acids. The c.499C>T mutation also leads to a premature stop codon at position 168. In both cases, critical functional domains of FGF5, including one heparin binding site, are lost. All animals analyzed were homozygous for one of the deleterious mutations or compound heterozygous for both (i.e. c.348delA, c.351_352insCATATAACATAG/c.499T). Sequencing of guanaco samples showed that the FGF5 gene encodes a full-length 270-amino acid protein. These results suggest that FGF5 is likely functional in short-haired wild species and non-functional in the domestic fiber-producing species, the llama. © 2017 Stichting International Foundation for Animal Genetics.

  8. Contrast-enhanced computed tomography of the gastrointestinal tract in clinically normal alpacas and llamas.

    Science.gov (United States)

    Stieger-Vanegas, Susanne M; Cebra, Christopher K

    2013-01-15

    To assess the feasibility and usefulness of CT enterography to evaluate the gastrointestinal tract in clinically normal llamas and alpacas. Prospective observational study. 7 clinically normal alpacas and 8 clinically normal llamas. The imaging protocol included orogastric administration of iodinated contrast material mixed with water. Three hours later, helical CT scanning was performed of the entire abdomen with transverse and multiplanar sagittal and dorsal projections before and after IV iodinated contrast agent injection. Both oral and IV contrast agents were well tolerated, and no adverse reactions were observed. Transverse images depicted the gastrointestinal tract and pancreas in the short axis; however, dorsal and sagittal projections aided in localizing and differentiating the various gastrointestinal segments, including the pancreas. In all camelids, the wall of the gastrointestinal tract was well differentiated. In all but 2 camelids, all gastrointestinal segments were well visualized and differentiated. In those 2 animals, the cecum was difficult to identify. Good distention of the small intestine was achieved by use of the oral contrast agent. The dorsal projections were useful to identify the pancreas in its entire length. The present study supplied new information about gastrointestinal wall thickness, intestinal diameter, and location of the pancreas and ileocecocolic junction in alpacas and llamas. Multiplanar contrast-enhanced CT was useful to reveal the various segments of the gastrointestinal tract, pancreas, and abdominal lymph nodes. The shorter time delay before imaging, compared with the delay with conventional barium studies, makes this technique complementary or superior to conventional radiographic or ultrasonographic studies for evaluation of the gastrointestinal tract.

  9. Comportamiento farmacocinético de la marbofloxacina y de la enrofloxacina en llamas ("Lama glama")

    OpenAIRE

    Rubio Langre, Sonia

    2011-01-01

    La marbofloxacina y la enrofloxacina son antimicrobianos pertenecientes al grupo de las fluoroquinolonas, desarrolladas exclusivamente para uso veterinario, que han demostrado poseer unas características farmacocinéticas adecuadas para su uso en diversas especies. El objetivo de este trabajo fue definir el comportamiento farmacocinético de la marbofloxacina y enrofloxacina en llamas (Lama glama), a dosis de 5 mg/kg de peso corporal. Para ello se estudió la disposición del fármaco tras la admi...

  10. Heterobilharzia americana infection and congestive heart failure in a llama (Lama glama).

    Science.gov (United States)

    Corapi, W V; Eden, K B; Edwards, J F; Snowden, K F

    2015-05-01

    The schistosome Heterobilharzia americana infects several mammalian species in the southeastern United States, including horses, but infections have not been reported in camelids. This is a report of H. americana infection in a 6-year-old llama with extensive cardiac pathology and congestive heart failure. Parasite-induced granulomas were widely disseminated and included overwhelming involvement of the lungs and liver. Microscopic lesions in the heart included myofiber degeneration and necrosis, with extensive replacement fibrosis. Polymerase chain reaction amplification and sequencing confirmed the presence of H. americana in the lungs. © The Author(s) 2014.

  11. Comparación entre los sitios de LLAMA y APEX

    Science.gov (United States)

    Bareilles, F. A.; Morras, R.; Hauscarriaga, F. P.; Guarrera, L.; Arnal, E. M.; Lepine, J. R. D.

    A comparison among the meteorological condition prevailing at the location of APEX (Atacama Pathfinder Experiment) telescope and the site selected to deploy LLAMA (Long Latin American Millimeter Array) is carried out. The later is dubbed Alto Chorrillo, and is located 4800 m above sea level and around 16 km eastward from the town of San Antonio de los Cobres (province of Salta). This work is part of a long term monitoring campaign aim at selecting sites for millimeter and submillimeter radioastronomy that is being carried out by the Instituto Argentino de Radioastronomía (IAR) since 2002. FULL TEXT IN SPANISH

  12. 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. ...

  13. Tilting the balance between canonical and noncanonical conformations for the H1 hypervariable loop of a llama VHH through point mutations.

    Science.gov (United States)

    Mahajan, Sai Pooja; Velez-Vega, Camilo; Escobedo, Fernando A

    2013-01-10

    Nanobodies are single-domain antibodies found in camelids. These are the smallest naturally occurring binding domains and derive functionality via three hypervariable loops (H1-H3) that form the binding surface. They are excellent candidates for antibody engineering because of their favorable characteristics like small size, high solubility, and stability. To rationally engineer antibodies with affinity for a specific target, the hypervariable loops can be tailored to obtain the desired binding surface. As a first step toward such a goal, we consider the design of loops with a desired conformation. In this study, we focus on the H1 loop of the anti-hCG llama nanobody that exhibits a noncanonical conformation. We aim to "tilt" the stability of the H1 loop structure from a noncanonical conformation to a (humanized) type 1 canonical conformation by studying the effect of selected mutations to the amino acid sequence of the H1, H2, and proximal residues. We use all-atomistic, explicit-solvent, biased molecular dynamic simulations to simulate the wild-type and mutant loops in a prefolded framework. We thus find mutants with increasing propensity to form a stable type 1 canonical conformation of the H1 loop. Free energy landscapes reveal the existence of conformational isomers of the canonical conformation that may play a role in binding different antigenic surfaces. We also elucidate the approximate mechanism and kinetics of transitions between such conformational isomers by using a Markovian model. We find that a particular three-point mutant has the strongest thermodynamic propensity to form the H1 type 1 canonical structure but also to exhibit transitions between conformational isomers, while a different, more rigid three-point mutant has the strongest propensity to be kinetically trapped in such a canonical structure.

  14. Framing Fragmentation

    DEFF Research Database (Denmark)

    Bundgaard, Charlotte

    2009-01-01

    Contemporary industrialized architecture based on advanced information technology and highly technological production processes, implies a radically different approach to architecture than what we have experienced in the past. Works of architecture composed of prefabricated building components......, contain distinctive architectural traits, not only based on rational repetition, but also supporting composition and montage as dynamic concepts. Prefab architecture is an architecture of fragmentation, individualization and changeability, and this sets up new challenges for the architect. This paper...... tries to develop a strategy for the architect dealing with industrially based architecture; a strategy which exploits architectural potentials in industrial building, which recognizes the rules of mass production and which redefines the architect’s position among the agents of building. If recent...

  15. Conversion of a Mouse Fab into a Whole Humanized IgG Antibody for Detecting Botulinum Toxin

    National Research Council Canada - National Science Library

    Palys, Thomas J; Schmid, Kara E; Scherer, John M; Schoepp, Randal J

    2006-01-01

    Antibodies serve as the gold standard in most immunodiagnostic assays. Recent advances in recombinant DNA technology have offered the production of antibody fragments or Fabs as promising alternatives...

  16. 16 kDa heat shock protein from heat-inactivated Mycobacterium tuberculosis is a homodimer - suitability for diagnostic applications with specific llama VHH monoclonals.

    Directory of Open Access Journals (Sweden)

    Saurabh K Srivastava

    Full Text Available BACKGROUND: The 16 kDa heat shock protein (HSP is an immuno-dominant antigen, used in diagnosis of infectious Mycobacterium tuberculosis (M.tb. causing tuberculosis (TB. Its use in serum-based diagnostics is limited, but for the direct identification of M.tb. bacteria in sputum or cultures it may represent a useful tool. Recently, a broad set of twelve 16 kDa specific heavy chain llama antibodies (VHH has been isolated, and their utility for diagnostic applications was explored. METHODOLOGY/PRINCIPAL FINDINGS: To identify the epitopes recognized by the nine (randomly selected from a set of twelve 16 kDa specific VHH antibodies distinct VHH antibodies, 14 overlapping linear epitopes (each 20 amino acid long were characterized using direct and sandwich ELISA techniques. Seven out of 14 epitopes were recognized by 8 out of 9 VHH antibodies. The two highest affinity binders B-F10 and A-23 were found to bind distinct epitopes. Sandwich ELISA and SPR experiments showed that only B-F10 was suitable as secondary antibody with both B-F10 and A-23 as anchoring antibodies. To explain this behavior, the epitopes were matched to the putative 3D structure model. Electrospray ionization time-of-flight mass spectrometry and size exclusion chromatography were used to determine the higher order conformation. A homodimer model best explained the differential immunological reactivity of A-23 and B-F10 against heat-treated M.tb. lysates. CONCLUSIONS/SIGNIFICANCE: The concentrations of secreted antigens of M.tb. in sputum are too low for immunological detection and existing kits are only used for identifying M.tb. in cultures. Here we describe how specific combinations of VHH domains could be used to detect the intracellular HSP antigen. Linked to methods of pre-concentrating M.tb. cells prior to lysis, HSP detection may enable the development of protein-based diagnostics of sputum samples and earlier diagnosis of diseases.

  17. The LLAMA 12 m mm/sub-mm radiotelescope in the Andes

    Science.gov (United States)

    Lepine, Jacques; Edemundo Arnal, Marcelo; de Graauw, Thijs; Abraham, Zulema; Gimenez de Castro, Guillermo; de Gouveia Dal Pino, Elisabete; Morras, Ricardo; Larrarte, Juan; Viramontes, José; Finger, Ricardo; Kooi, Jacob; Reeves, Rodrigo; Beaklini, Pedro

    2015-08-01

    LLAMA (Large Latin American Millimetric Array) is a joint Argentinean-Brazilian project of a 12m mm/sub-mm radio telescope similar to the APEX antenna, to be installed at a site at 4800 m altitude near San Antonio de Los Cobres in the Salta Province in Argentine, at 150 km from ALMA. The scientific cases for single dish and VLBI observations include black holes and accretion disks, the molecular evolution of interstellar clouds, the structure of the Galaxy, the formation of galaxies, and much more. The antenna was ordered to the company Vertex Antennentechnik in June 2014, and the construction is progressing quickly; it will be installed at the site in 2016. The radio telescope will be equipped with up to six receivers covering bands similar to those of ALMA. Cryostats with room for 3 cartridges, constructed by NAOJ (Tokyo,Japan), will be installed in each of the two Nasmyth cabins. Among the first receivers we will have an ALMA band 9 provided by NOVA (Groningen, Holland) and a band 5 from the Chalmers University (Sweden). Other receivers are still being discussed at the time of submission of this abstract,At high frequencies, VLBI observations at high frequencies could be made with ALMA, APEX and ASTE, and Northern radiotelescopes. In this way, LLAMA will be a seed for a Latin-American VLBI network.

  18. Collection and analysis of peritoneal fluid from healthy llamas and alpacas.

    Science.gov (United States)

    Cebra, Christopher K; Tornquist, Susan J; Reed, Shannon K

    2008-05-01

    To describe a technique for abdominocentesis in camelids and report peritoneal fluid biochemical and cytologic findings from healthy llamas and alpacas. Prospective study. Animals-17 adult llamas and 5 adult alpacas. Right paracostal abdominocentesis was performed. Peritoneal fluid was collected by gravity flow into tubes containing potassium-EDTA for cell count and cytologic evaluation and lithium heparin for biochemical analysis. Blood samples were collected via jugular venipuncture into heparinized tubes at the same time. Cytologic components were quantified. Fluid pH and concentrations of total carbon dioxide, sodium, potassium, chloride, lactate, and glucose were compared between peritoneal fluid and venous blood. All but 3 camelids had peritoneal fluid cell counts of or = 2.5 g/dL. Peritoneal fluid of camelids generally contained slightly less glucose, lactate, and sodium and roughly equal concentrations of potassium and chloride as venous blood. Peritoneal fluid was collected safely from healthy camelids. Compared with blood, peritoneal fluid usually had a low cell count and protein concentration, but some individuals had higher values. Electrolyte concentrations resembled those found in blood. High cell counts and protein concentrations found in peritoneal fluid of some healthy camelids may overlap with values found in diseased camelids, complicating interpretation of peritoneal fluid values.

  19. Evaluation of insulin resistance in two kinds of South American camelids: llamas and alpacas.

    Science.gov (United States)

    Araya, A V; Atwater, I; Navia, M A; Jeffs, S

    2000-10-01

    Insulin resistance was evaluated in South American camelids, llamas and alpacas, by use of the minimal model test and the insulin tolerance test. Animals were catheterized for long-term studies and tamed to minimize stress during evaluation. Results indicated a low insulin sensitivity index (SI) = 0 to 0.97, median = 0.39 x 10(-4) min/uIU x ml, about a fifth the value in other mammals and humans. The KITT was between 1.43 and 3.19 %/min, also significantly lower than that reported for humans. Glycosylated hemoglobin concentration was 6%, and HbAlc concentration was 5.5%; red blood cell lifetime, as measured by use of the 51Cr method, was 120 days, similar to the value in humans. We concluded that llamas and alpacas have naturally higher blood glucose concentration than do humans and other mammals during the glucose tolerance test. Using the same mathematical tools to evaluate glucose metabolism as those used in people, South American camelids appear to be resistant to insulin. Thus, the South American camelid may be a useful new animal model for the study of sugar metabolism and various facets of diabetes mellitus, especially protection from the deleterious effects of glycosylation.

  20. Tumor detection using radiolabeled monoclonal antibodies

    International Nuclear Information System (INIS)

    Moldofsky, P.J.; Powe, J.; Hammond, N.D.

    1987-01-01

    Radioisotope conjugated to monoclonal antibody products has been used for imaging tumors targeted by the antibody. As imaging progresses, new sets of procedural and technical questions arise. In this chapter, we discuss several current problems in imaging tumor with radiolabeled monoclonal antibody. These include (1) methods for selection of specific antibody and, once the particular antibody is selected, which fragment form is to be used; (2) imaging procedures: what are the optimum imaging parameters, such as optimum time for imaging after administration of tracer and considerations regarding background subtraction; and (3) noninvasive quantitative techniques: quantitation of localization of antibody indirectly from quantitative information in the images.100 references

  1. Altered specificity of single-chain antibody fragments bound to pandemic H1N1-2009 influenza virus after conversion of the phage-bound to the soluble form

    Directory of Open Access Journals (Sweden)

    Kaku Yoshihiro

    2012-09-01

    Full Text Available Abstract Background In 2009, a novel influenza A/H1N1 virus (H1N1pdm quickly spread worldwide and co-circulated with then-existing seasonal H1N1 virus (sH1N1. Distinguishing between these 2 viruses was necessary to better characterize the epidemiological properties of the emergent virus, including transmission patterns, pathogenesis, and anti-influenza drug resistance. This situation prompted us to develop a point-of-care virus differentiation system before entering the 2009–2010 influenza season. Aiming to establish H1N1pdm-specific detection tools rapidly, we employed phage display libraries to select H1N1pdm-specific single-chain variable fragments (scFvs. Findings Human single-fold scFv libraries (Tomlinson I + J underwent selection for the ability to bind H1N1pdm virus particles. Three rounds of panning brought 1152 phage-bound scFvs, of which 58 clones reacted with H1N1pdm specifically or preferentially over sH1N1 in an enzyme-linked immunosorbent assay (ELISA. After conversion of the scFvs to soluble form, 7 clones demonstrating high/stable expression were finally obtained. However, all the soluble scFvs except No. 29 were found to have lost their specificity/preference for H1N1pdm in ELISA. The specificity/preference of No. 29 was also confirmed by immunofluorescence assay and immunoprecipitation, and the viral nucleoprotein was identified by ELISA as its target protein. The change in specificity associated with scFv conversion from phage-bound to soluble form could be due to loss of phage scaffold pIII protein, which likely provides structural support for the scFv antigen-binding site. It is also possible that the similar antigenic properties of H1N1pdm and sH1N1 led to the observed alterations in scFv specificity. Discussion Using a phage display library, we obtained 7 soluble scFv clones reactive against H1N1pdm; however, only 1 showed specificity/preference toward H1N1pdm. Our results confirmed that using phage display

  2. 1981-82 Project Evaluation for Encendiendo Una Llama: A Program for Bilingual Gifted and Talented Students.

    Science.gov (United States)

    Roby, Wallace

    The operation of "Encendiendo Una Llama," Hartford, Connecticut's program for bilingual gifted students, was evaluated for the 1981-82 school year. A total of 173 gifted children of limited English proficiency in grades 3 through 6 were served by the program at four locations. The program, staff, objectives, and target population are…

  3. Morphofunctional structure of the lingual papillae in three species of South American Camelids: Alpaca, guanaco, and llama.

    Science.gov (United States)

    Erdoğan, Serkan; Villar Arias, Silvia; Pérez, William

    2016-02-01

    The aim of this study was to compare the anatomical and functional characteristics of the lingual papilla among the Camelidae. For this purpose, tongues of alpaca, guanaco, and llama were used. Numerous long and thin filiform papillae were located in the median groove and none were detected on the rest of the dorsal surface of the lingual apex in alpaca. Secondary papillae originated from the base of some filiform papillae on the ventral surface of alpaca tongue. The bases of some filiform papillae of the lateral surface of the lingual apex were inserted into conspicuous grooves in guanaco and tips of filiform papillae on the dorsal surface of the lingual body were ended by bifurcated apex. On the dorsal surface of the lingual apex of llama, there were no filiform papillae but there were numerous filiform papillae on both the lateral margins of the ventral surface of the lingual apex. Fungiform papillae were distributed randomly on dorsal lingual surface and ventral margins of the tongues of all camelid species. Lenticular papillae were located on the lingual torus and varied in size and topographical distribution for each species. Circumvallate papillae had irregular surfaces in llama and alpaca, and smooth surface in guanaco. In conclusion, llama and alpaca tongues were more similar to each other, and tongues of all camelid species displayed more similarities to those of Bactrian and dromedary camels in comparison with other herbivores and ruminants. © 2015 Wiley Periodicals, Inc.

  4. Assessment of the effects of epinephrine and insulin on plasma and serum biochemical variables in llamas and alpacas.

    Science.gov (United States)

    Cebra, Christopher K; Tornquist, Susan J

    2004-12-01

    To describe the metabolic effects of epinephrine administration in New World camelids and investigate whether these effects are influenced by administration of insulin. 6 llamas and 8 alpacas (all adult castrated males). Prior to each experiment, food was withheld from camelids for 8 hours. On each of 2 consecutive days, alpacas were administered epinephrine (10 mg/kg, IM; time 0); alpacas were randomly assigned to receive regular insulin (0.2 U/kg, IV) immediately after epinephrine administration on one of those days. In llamas, the experiment was performed once after administration of epinephrine only. At 0, 30, 60, 90, 120, 150, 180, 210, and 240 minutes after treatment, blood samples were collected and several serum or plasma biochemical variables were assessed; in addition, plasma samples from llamas were assessed for insulin concentrations. Data were compared between days (alpacas only) and between time points. Administration of epinephrine induced mobilization of glucose, triglycerides, nonesterified fatty acids, and beta-hydroxybutyrate. A small increase in endogenous insulin concentration was detected in epinephrine-treated llamas, compared with baseline values. Overall, insulin administration decreased, negated, or delayed the epinephrine-associated increases in serum or plasma concentrations of circulating energy substrates, except that it augmented the epinephrine-associated increase in concentration of triglycerides. Epinephrine appeared to mobilize energy substrates in camelids and hence may be involved in the pathogenesis of disorders of glucose and fat metabolism. Insulin appeared to antagonize most of these effects, and its administration may have therapeutic value in camelids.

  5. 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.

  6. Applications of recombinant antibodies in plant pathology.

    Science.gov (United States)

    Ziegler, Angelika; Torrance, Lesley

    2002-09-01

    Summary Advances in molecular biology have made it possible to produce antibody fragments comprising the binding domains of antibody molecules in diverse heterologous systems, such as Escherichia coli, insect cells, or plants. Antibody fragments specific for a wide range of antigens, including plant pathogens, have been obtained by cloning V-genes from lymphoid tissue, or by selection from large naive phage display libraries, thus avoiding the need for immunization. The antibody fragments have been expressed as fusion proteins to create different functional molecules, and fully recombinant assays have been devised to detect plant viruses. The defined binding properties and unlimited cheap supply of antibody fusion proteins make them useful components of standardized immunoassays. The expression of antibody fragments in plants was shown to confer resistance to several plant pathogens. However, the antibodies usually only slowed the progress of infection and durable 'plantibody' resistance has yet to be demonstrated. In future, it is anticipated that antibody fragments from large libraries will be essential tools in high-throughput approaches to post-genomics research, such as the assignment of gene function, characterization of spatio-temporal patterns of protein expression, and elucidation of protein-protein interactions.

  7. Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

    Energy Technology Data Exchange (ETDEWEB)

    Veggiani, Gianluca; Ossolengo, Giuseppe; Aliprandi, Marisa; Cavallaro, Ugo [IFOM-IEO Campus, Via Adamello 16, 20139 Milano (Italy); Marco, Ario de, E-mail: ario.demarco@ung.si [IFOM-IEO Campus, Via Adamello 16, 20139 Milano (Italy); Dept. Environmental Sciences, University of Nova Gorica (UNG), Vipavska 13, P.O. Box 301-SI-5000, Rozna Dolina, Nova Gorica (Slovenia)

    2011-05-20

    Highlights: {yields} Recombinant antibodies for FGFR1 were isolated from a llama naive library in VHH format. {yields} These antibodies compete with the natural ligand FGF-2 for the same epitope on FGFR1. {yields} The antibody competition inhibits the FGF-2-dependent internalization of FGFR1. -- Abstract: Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naive library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.

  8. Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

    International Nuclear Information System (INIS)

    Veggiani, Gianluca; Ossolengo, Giuseppe; Aliprandi, Marisa; Cavallaro, Ugo; Marco, Ario de

    2011-01-01

    Highlights: → Recombinant antibodies for FGFR1 were isolated from a llama naive library in VHH format. → These antibodies compete with the natural ligand FGF-2 for the same epitope on FGFR1. → The antibody competition inhibits the FGF-2-dependent internalization of FGFR1. -- Abstract: Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naive library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.

  9. Clinical, ultrasonographic, and laboratory findings in 12 llamas and 12 alpacas with malignant round cell tumors

    Science.gov (United States)

    Martin, Jeanne M.; Valentine, Beth A.; Cebra, Christopher K.

    2010-01-01

    Clinical signs, duration of illness, clinicopathologic findings, and ultrasonographic findings were evaluated in 12 llamas and 12 alpacas with malignant round cell tumors (MRCT). All but 1 animal died or was euthanized. Common clinical findings were anorexia, recumbency or weakness, and weight loss or poor growth. Peripheral lymphadenomegaly occurred in only 7 animals and was detected more often at necropsy than during physical examination. Common clinicopathologic abnormalities were hypoalbuminemia, acidosis, azotemia, anemia, hyperglycemia, and neutrophilia. Ultrasonography detected tumors in 4/6 animals. Cytologic evaluation of fluid or tissue aspirates or histopathology of biopsy tissue was diagnostic in 5/6 cases. A clinical course of 2 wk or less prior to death or euthanasia was more common in animals ≤ 2 y of age (9/11) than in older animals (6/13). Regular examination of camelids to include clinical pathology and evaluation of peripheral lymph nodes may result in early detection of MCRT. PMID:21358931

  10. 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 ...

  11. 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 ...

  12. [Progress of research on genetic engineering antibody and its application in prevention and control of parasitic diseases].

    Science.gov (United States)

    Yao, Yuan; Yu, Chuan-xin

    2013-08-01

    Antibody has extensive application prospects in the biomedical field. The inherent disadvantages of traditional polyclonal antibody and monoclonal antibody limit their application values. The humanized and fragmented antibody remodeling has given a rise to a series of genetic engineered antibody variant. This paper reviews the progress of research on genetic engineering antibody and its application in prevention and control of parasitic diseases.

  13. Proyecto "LLAMA"

    Science.gov (United States)

    Arnal, E. M.; Mirabel, I. F.; Morras, R.; Romero, G. E.; Abraham, Z.; de Gouveira Dal Pino, E. M.; Lepine, J.

    In this paper we briefly describe a joint scientific and technological effort between Argentina and Brazil, whose first goal is to install and run, in the northwestern part of Argentina, a millimetre and submillimetre observa- tional facility. In the long run, we would like to incorporate this dish to existing ones (ALMA, APEX, ASTE) in the northern extreme of Chile, to be able to carry out, for the first time in Latinamerican soil, very long base- line interferometry at mm/submm wavelengths. We also succintly mention a long term campaign that is under way in order to monitor the transparency of the atmosphere at those wavelengths. The science that can be accom- plished with this instrument, the technology transfer spin-offs related to this project, and the scientific and strategic importance of this project within both the Argentinean and Latinamerican radioastronomy is described. FULL TEXT IN SPANISH

  14. Oestradiol-17β plasma concentrations after intramuscular injection of oestradiol benzoate or oestradiol cypionate in llamas (Lama glama

    Directory of Open Access Journals (Sweden)

    Aba Marcelo A

    2010-02-01

    Full Text Available Abstract Background Llamas (Lama glama are induced ovulators and the process of ovulation depends on dominant follicular size. In addition, a close relationship between behavioural estrus and ovulation is not registered in llamas. Therefore, the exogenous control of follicular development with hormones aims to predict the optimal time to mate. Oestradiol-17β (E2 and its esters are currently used in domestic species, including camelids, in synchronization treatments. But, in llamas, there is no reports regarding the appropriate dosages to be used and most protocols have been designed by extrapolation from those recommended for other ruminants. The aim of the present study was to characterize plasma E2 concentrations in intact female llamas following a single intramuscular (i.m. injection of two oestradiol esters: oestradiol benzoate (EB and oestradiol cypionate (ECP. Methods Twelve non pregnant and non lactating sexually mature llamas were i.m. injected on day 0 with 2.5 mg of EB (EB group, n = 6 or ECP (ECP group, n = 6. Blood samples were collected immediately before injection, at 1, 6, 12, 24 h after treatment and then daily until day 14 post injection. Changes in hormone concentrations with time were analyzed in each group by analysis of variance (ANOVA using a repeated measures (within-SS design. Plasma E2 concentrations and area under the concentration-time curve (AUC values were compared between groups by ANOVA. In all cases a Least-Significant Difference test (LSD was used to determine differences between means. Hormonal and AUC data are expressed as mean ± S.E.M. Results Peak plasma E2 concentrations were achieved earlier and were higher in EB group than in ECP group. Thereafter, E2 returned to physiological concentrations earlier in EB group (day 5 than in ECP group (day 9. Although plasma E2 profiles differed over time among groups there were no differences between them on AUC values. Conclusions The i.m. injection of a single dose

  15. Oestradiol-17β plasma concentrations after intramuscular injection of oestradiol benzoate or oestradiol cypionate in llamas (Lama glama)

    Science.gov (United States)

    2010-01-01

    Background Llamas (Lama glama) are induced ovulators and the process of ovulation depends on dominant follicular size. In addition, a close relationship between behavioural estrus and ovulation is not registered in llamas. Therefore, the exogenous control of follicular development with hormones aims to predict the optimal time to mate. Oestradiol-17β (E2) and its esters are currently used in domestic species, including camelids, in synchronization treatments. But, in llamas, there is no reports regarding the appropriate dosages to be used and most protocols have been designed by extrapolation from those recommended for other ruminants. The aim of the present study was to characterize plasma E2 concentrations in intact female llamas following a single intramuscular (i.m.) injection of two oestradiol esters: oestradiol benzoate (EB) and oestradiol cypionate (ECP). Methods Twelve non pregnant and non lactating sexually mature llamas were i.m. injected on day 0 with 2.5 mg of EB (EB group, n = 6) or ECP (ECP group, n = 6). Blood samples were collected immediately before injection, at 1, 6, 12, 24 h after treatment and then daily until day 14 post injection. Changes in hormone concentrations with time were analyzed in each group by analysis of variance (ANOVA) using a repeated measures (within-SS) design. Plasma E2 concentrations and area under the concentration-time curve (AUC) values were compared between groups by ANOVA. In all cases a Least-Significant Difference test (LSD) was used to determine differences between means. Hormonal and AUC data are expressed as mean ± S.E.M. Results Peak plasma E2 concentrations were achieved earlier and were higher in EB group than in ECP group. Thereafter, E2 returned to physiological concentrations earlier in EB group (day 5) than in ECP group (day 9). Although plasma E2 profiles differed over time among groups there were no differences between them on AUC values. Conclusions The i.m. injection of a single dose of both

  16. 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- ...

  17. Production of a phage-displayed single chain variable fragment ...

    African Journals Online (AJOL)

    Purpose: To develop specific single chain variable fragments (scFv) against infectious bursal disease virus (IBDV) via phage display technology. Methods: Purified viruses were initially applied for iterative panning rounds of scFv phage display libraries. The binding ability of the selected scFv antibody fragments against the ...

  18. Microbial ecology involved in the ripening of naturally fermented llama meat sausages. A focus on lactobacilli diversity.

    Science.gov (United States)

    Fontana, Cecilia; Bassi, Daniela; López, Constanza; Pisacane, Vincenza; Otero, Maria Claudia; Puglisi, Edoardo; Rebecchi, Annalisa; Cocconcelli, Pier Sandro; Vignolo, Graciela

    2016-11-07

    Llama represents for the Andean regions a valid alternative to bovine and pork meat and thanks to the high proteins and low fat content; it can constitute a good product for the novel food market. In this study, culture-dependent and independent methods were applied to investigate the microbial ecology of naturally fermented llama sausages produced in Northwest Argentina. Two different production technologies of llama sausage were investigated: a pilot-plant scale (P) and an artisanal one (A). Results obtained by High-Throughput Sequencing (HTS) of 16S rRNA amplicons showed that the production technologies influenced the development of microbial communities with a different composition throughout the entire fermentation process. Both sequencing and microbiological counts demonstrated that Lactic Acid Bacteria (LAB) contributed largely to the dominant microbiota. When a total of 230 isolates were approached by RAPD-PCR, presumptive LAB strains from P production exhibited an initial variability in RAPD fingerprints switching to a single profile at the final of ripening, while A production revealed a more heterogeneous RAPD pattern during the whole fermentation process. The constant presence of Lactobacillus sakei along the fermentation in both productions was revealed by HTS and confirmed by species-specific PCR from isolated strains. The technological characterization of Lb. sakei isolates evidenced their ability to grow at 15°C, pH4.5 and 5% NaCl (95%). Most strains hydrolyzed myofibrillar and sarcoplasmic proteins. Bacteriocins encoding genes and antimicrobial resistance were found in 35% and 42.5% of the strains, respectively. An appropriate choice of a combination of autochthonous strains in a starter formulation is fundamental to improve and standardize llama sausages safety and quality. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. In vivo phage display screening for tumor vascular targets in glioblastoma identifies a llama nanobody against dynactin-1-p150Glued.

    Science.gov (United States)

    van Lith, Sanne A M; Roodink, Ilse; Verhoeff, Joost J C; Mäkinen, Petri I; Lappalainen, Jari P; Ylä-Herttuala, Seppo; Raats, Jos; van Wijk, Erwin; Roepman, Ronald; Letteboer, Stef J; Verrijp, Kiek; Leenders, William P J

    2016-11-01

    Diffuse gliomas are primary brain cancers that are characterised by infiltrative growth. Whereas high-grade glioma characteristically presents with perinecrotic neovascularisation, large tumor areas thrive on pre-existent vasculature as well. Clinical studies have revealed that pharmacological inhibition of the angiogenic process does not improve survival of glioblastoma patients. Direct targeting of tumor vessels may however still be an interesting therapeutic approach as it allows pinching off the blood supply to tumor cells. Such tumor vessel targeting requires the identification of tumor-specific vascular targeting agents (TVTAs).Here we describe a novel TVTA, C-C7, which we identified via in vivo biopanning of a llama nanobody phage display library in an orthotopic mouse model of diffuse glioma. We show that C-C7 recognizes a subpopulation of tumor blood vessels in glioma xenografts and clinical glioma samples. Additionally, C-C7 recognizes macrophages and activated endothelial cells in atherosclerotic lesions. By using C-C7 as bait in yeast-2-hybrid (Y2H) screens we identified dynactin-1-p150Glued as its binding partner. The interaction was confirmed by co-immunostainings with C-C7 and a commercial anti-dynactin-1-p150Glued antibody, and via co-immunoprecipitation/western blot studies. Normal brain vessels do not express dynactin-1-p150Glued and its expression is reduced under anti-VEGF therapy, suggesting that dynactin-1-p150Glued is a marker for activated endothelial cells.In conclusion, we show that in vivo phage display combined with Y2H screenings provides a powerful approach to identify tumor-targeting nanobodies and their binding partners. Using this combination of methods we identify dynactin-1-p150Glued as a novel targetable protein on activated endothelial cells and macrophages.

  20. Adaptive functional specialisation of architectural design and fibre type characteristics in agonist shoulder flexor muscles of the llama, Lama glama.

    Science.gov (United States)

    Graziotti, Guillermo H; Chamizo, Verónica E; Ríos, Clara; Acevedo, Luz M; Rodríguez-Menéndez, J M; Victorica, C; Rivero, José-Luis L

    2012-08-01

    Like other camelids, llamas (Lama glama) have the natural ability to pace (moving ipsilateral limbs in near synchronicity). But unlike the Old World camelids (bactrian and dromedary camels), they are well adapted for pacing at slower or moderate speeds in high-altitude habitats, having been described as good climbers and used as pack animals for centuries. In order to gain insight into skeletal muscle design and to ascertain its relationship with the llama's characteristic locomotor behaviour, this study examined the correspondence between architecture and fibre types in two agonist muscles involved in shoulder flexion (M. teres major - TM and M. deltoideus, pars scapularis - DS and pars acromialis - DA). Architectural properties were found to be correlated with fibre-type characteristics both in DS (long fibres, low pinnation angle, fast-glycolytic fibre phenotype with abundant IIB fibres, small fibre size, reduced number of capillaries per fibre and low oxidative capacity) and in DA (short fibres, high pinnation angle, slow-oxidative fibre phenotype with numerous type I fibres, very sparse IIB fibres, and larger fibre size, abundant capillaries and high oxidative capacity). This correlation suggests a clear division of labour within the M. deltoideus of the llama, DS being involved in rapid flexion of the shoulder joint during the swing phase of the gait, and DA in joint stabilisation during the stance phase. However, the architectural design of the TM muscle (longer fibres and lower fibre pinnation angle) was not strictly matched with its fibre-type characteristics (very similar to those of the postural DA muscle). This unusual design suggests a dual function of the TM muscle both in active flexion of the shoulder and in passive support of the limb during the stance phase, pulling the forelimb to the trunk. This functional specialisation seems to be well suited to a quadruped species that needs to increase ipsilateral stability of the limb during the support

  1. 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

  2. Cow, sheep and llama manure at psychrophilic anaerobic co-digestion with low cost tubular digesters in cold climate and high altitude.

    Science.gov (United States)

    Martí-Herrero, J; Alvarez, R; Cespedes, R; Rojas, M R; Conde, V; Aliaga, L; Balboa, M; Danov, S

    2015-04-01

    The aim of this research is to evaluate the co-digestion of cow and llama manure combined with sheep manure, in psychrophilic conditions and real field low cost tubular digesters adapted to cold climate. Four digesters were monitored in cold climate conditions; one fed with cow manure, a second one with llama manure, the third one with co-digestion of cow-sheep manure and the fourth one was fed with llama-sheep manure. The slurry had a mean temperature of 16.6 °C, the organic load rate was 0.44 kgvs m(-3) d(-1) and the hydraulic retention time was 80 days. After one hundred days biogas production was stable, as was the methane content and the pH of the effluent. The co-digestion of cow-sheep manure results in a biogas production increase of 100% compared to the mono-digestion of cow manure, while co-digestion of llama-sheep manure results in a decrease of 50% in biogas production with respect to mono-digestion of llama manure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Cataracts in New World camelids (llamas, alpacas, vicuñas, and guanacos).

    Science.gov (United States)

    Gionfriddo, Juliet R

    2002-05-01

    Cataracts are the most frequently seen lens diseases in New World camelids. The causes of cataracts are unknown in many animals, but cataracts secondary to intraocular inflammation seem to be common. Congenital or juvenile-onset cataracts, if another cause is not apparent, should be considered as possibly caused by heredity, and the affected animals should not be bred. Persistent hyaloid vascular anomalies may also have an important role in cataract formation and could be heritable or caused by an in utero disturbance. Pedigree analyses, test breedings, and possibly DNA studies of llamas with cataracts will be required to determine their potential heritability in these species. Cataract surgery can be done successfully in camelids. It is important to evaluate the posterior segment with B scan ultrasonography before surgery in animals in which the posterior segment previously has not been seen. This evaluation allows the surgeon to better prepare for the presence of hyaloid vascular anomalies. Use of phacoemulsification, gentle tissue handling, liberal use of anti-inflammatory medications and endothelial protectants (BSS + and viscoelastics) during surgery has increased the success rate of this surgery in camelids. Unlike cataract surgery in dogs and horses undergoing, cataract surgery, in camelids seems to be important to remove much of the posterior lens capsule. This removal prevents severe capsular fibrosis and subsequent vision loss. There is evidence that a posterior capsulectomy and anterior viterectomy can help prevent postoperative glaucoma. Research needs to be done to see whether these species have an increased risk for ciliary-block glaucoma.

  4. SL15: A seminal plasma-derived lectin from the sperm of llama (Lama glama).

    Science.gov (United States)

    Zampini, Renato; Sequeira, Sabrina; Argañaraz, Martin E; Apichela, Silvana A

    2017-07-01

    The oviductal sperm reservoir of South American camelids is formed when sperm bind to N-acetylgalactosamine (GalNAc) on the surface of oviductal epithelium. The aim of this study was to characterize the GalNAc-binding proteins on llama sperm, and to establish their origin. Sperm-adsorbed proteins were extracted with 0.5 M KCl in Hepes-balanced salts. Sperm-adsorbed and seminal plasma proteins were then subjected to ligand blotting for their GalNAc affinity, and the labeled bands were identified by mass spectrometry. Three proteins were identified in seminal plasma versus only one in the sperm-adsorbed population; SL15, a seminal lectin, was common to both. SL15 is a homologue of Zymogen granule protein 16, homolog B-like, which belongs to the Jacalin-related lectin family. This lectin is likely presented to sperm via seminal plasma since epididymal sperm are not capable of binding GalNAc, whereas ejaculated sperm does, and its transcript was enriched predominantly in the prostate and bulbourethral glands. This is the first report of a seminal lectin in South American camelids that originates in the male reproductive tract, and is probably involved in sperm reservoir formation. © 2017 Wiley Periodicals, Inc.

  5. Universal elements of fragmentation

    International Nuclear Information System (INIS)

    Yanovsky, V. V.; Tur, A. V.; Kuklina, O. V.

    2010-01-01

    A fragmentation theory is proposed that explains the universal asymptotic behavior of the fragment-size distribution in the large-size range, based on simple physical principles. The basic principles of the theory are the total mass conservation in a fragmentation process and a balance condition for the energy expended in increasing the surface of fragments during their breakup. A flux-based approach is used that makes it possible to supplement the basic principles and develop a minimal theory of fragmentation. Such a supplementary principle is that of decreasing fragment-volume flux with increasing energy expended in fragmentation. It is shown that the behavior of the decreasing flux is directly related to the form of a power-law fragment-size distribution. The minimal theory is used to find universal asymptotic fragment-size distributions and to develop a natural physical classification of fragmentation models. A more general, nonlinear theory of strong fragmentation is also developed. It is demonstrated that solutions to a nonlinear kinetic equation consistent with both basic principles approach a universal asymptotic size distribution. Agreement between the predicted asymptotic fragment-size distributions and experimental observations is discussed.

  6. Poly(I:C) adjuvant strongly enhances parasite-inhibitory antibodies and Th1 response against Plasmodium falciparum merozoite surface protein-1 (42-kDa fragment) in BALB/c mice.

    Science.gov (United States)

    Mehrizi, Akram Abouie; Rezvani, Niloufar; Zakeri, Sedigheh; Gholami, Atefeh; Babaeekhou, Laleh

    2018-04-01

    Malaria vaccine development has been confronted with various challenges such as poor immunogenicity of malaria vaccine candidate antigens, which is considered as the main challenge. However, this problem can be managed using appropriate formulations of antigens and adjuvants. Poly(I:C) is a potent Th1 inducer and a human compatible adjuvant capable of stimulating both B- and T-cell immunity. Plasmodium falciparum merozoite surface protein 1 42 (PfMSP-1 42 ) is a promising vaccine candidate for blood stage of malaria that has faced several difficulties in clinical trials, mainly due to improper adjuvants. Therefore, in the current study, poly(I:C), as a potent Th1 inducer adjuvant, was evaluated to improve the immunogenicity of recombinant PfMSP-1 42 , when compared to CFA/IFA, as reference adjuvant. Poly(I:C) produced high level and titers of anti-PfMSP-1 42 IgG antibodies in which was comparable to CFA/IFA adjuvant. In addition, PfMSP-1 42 formulated with poly(I:C) elicited a higher ratio of IFN-γ/IL-4 (23.9) and IgG2a/IgG1 (3.77) with more persistent, higher avidity, and titer of IgG2a relative to CFA/IFA, indicating a potent Th1 immune response. Poly(I:C) could also help to induce anti-PfMSP-1 42 antibodies with higher growth-inhibitory activity than CFA/IFA. Altogether, the results of the current study demonstrated that poly(I:C) is a potent adjuvant that can be appropriate for being used in PfMSP-1 42 -based vaccine formulations.

  7. Aligning physics and physiology: Engineering antibodies for radionuclide delivery.

    Science.gov (United States)

    Tsai, Wen-Ting K; Wu, Anna M

    2018-03-14

    The exquisite specificity of antibodies and antibody fragments renders them excellent agents for targeted delivery of radionuclides. Radiolabeled antibodies and fragments have been successfully used for molecular imaging and radioimmunotherapy (RIT) of cell surface targets in oncology and immunology. Protein engineering has been used for antibody humanization essential for clinical applications, as well as optimization of important characteristics including pharmacokinetics, biodistribution, and clearance. Although intact antibodies have high potential as imaging and therapeutic agents, challenges include long circulation time in blood, which leads to later imaging time points post-injection and higher blood absorbed dose that may be disadvantageous for RIT. Using engineered fragments may address these challenges, as size reduction and removal of Fc function decreases serum half-life. Radiolabeled fragments and pretargeting strategies can result in high contrast images within hours to days, and a reduction of RIT toxicity in normal tissues. Additionally, fragments can be engineered to direct hepatic or renal clearance, which may be chosen based on the application and disease setting. This review discusses aligning the physical properties of radionuclides (positron, gamma, beta, alpha, and Auger emitters) with antibodies and fragments and highlights recent advances of engineered antibodies and fragments in preclinical and clinical development for imaging and therapy. Copyright © 2018 John Wiley & Sons, Ltd.

  8. The LLAMA Project: A SINFONI Study of Gas Outflows and Feeding in Local, X-ray Selected AGN

    Science.gov (United States)

    Shimizu, Thomas Taro; Davies, Richard; Burtscher, Leonard; Lin, Ming-yi

    2018-01-01

    We present new results from our survey of the inner few hundred parsecs of nearby galaxies as part of our Local Luminous AGN with Matched Analogues (LLAMA) project. AGN within the LLAMA sample were selected based on detection at ultra-hard X-rays (14-195 keV) by the Swift/Burst Alert Telescope ensuring the definitive presence of an AGN. We further imposed a redshift (z 42.5) cutoff to create a complete and volume-limited sample of nearby, luminous AGN. Inactive galaxies were chosen carefully by matching in redshift, host galaxy morphology, inclination, and stellar mass to create a clean sample with which to compare to the AGN. A subset of LLAMA AGN and inactive galaxies were observed with VLT/SINFONI using adaptive optics producing high spatial resolution integral field unit spectra in the H and K band. This unique IFU data allows for analysis of a suite of NIR emission lines including [FeII], H2 (1-0) S(1), [SiVI], and Br-gamma to probe the ionized and warm molecular gas in the circumnuclear region as well as CO absorption lines to probe the stellar disk. I will present initial results from our study including the prevalence of AGN outflows along with their geometry, kinematics, and mass outflow rates and compare the mass, state, and excitation mechanisms of circumnuclear gas between AGN and inactive galaxies. Finally, I will discuss our results in the context of AGN fuelling and feedback and provide insight on interpreting similar data at higher redshift.

  9. Effect of forage quality on intake, chewing activity, faecal particle size distribution, and digestibility of neutral detergent fibre in sheep, goats, and llamas

    DEFF Research Database (Denmark)

    Jalali, Alireza; Nørgaard, Peder; Weisbjerg, Martin Riis

    2012-01-01

    types of forage for two periods in a crossover design. The species included six adult, non-pregnant female Danish Landrace goats, Shropshire sheep, and Lama glama llamas with body weights of 45 ± 5, 75 ± 6, and 135 ± 20 kg (mean ± SD), respectively. Forage included chopped artificially dried grass hay.......05). Sheep and goats had a higher NDF intake per kg BW than did llamas when fed GSS (P ... chewing was higher in sheep than in goats (P goats than in sheep (P goats or sheep (P

  10. Anatomía macroscópica, irrigación y drenaje venoso del aparato reproductor femenino de la llama (Lama glama)

    OpenAIRE

    León M., Eric; Sato S., Alberto; Navarrete Z., Miluska; Cisneros S., Jannet

    2011-01-01

    Se hizo la descripción anatómica del tracto reproductor femenino de la llama. Se usaron 4 llamas adultas. Macroscópicamente, la anatomía del aparato reproductor es morfológicamente similar a la del bovino, diferenciándose por la ausencia de ligamento intercornual y cotiledones, así como por la presentación de un tabique intercornual, como es el caso de la alpaca. La distribución de las arterias y venas que irrigaron y drenaron sangre a la cavidad pélvica y aparato reproductor presentaron en u...

  11. Universality of fragment shapes.

    Science.gov (United States)

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-03-16

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism.

  12. Energy metabolism and methane production in llamas, sheep and goats fed high- and low-quality grass-based diets

    DEFF Research Database (Denmark)

    Nielsen, Mette O.; Kiani, Ali; Tejada, Einstein

    2014-01-01

    goats and six Shropshire sheep, were used in a crossover design study. The experiment lasted for two periods of three weeks. Half of the animals were fed either high-quality grass hay (HP) or low-quality grass seed straw (LP) during each period. Animals were placed in metabolic cages during the last 5 d......, and gaseous exchange was measured by open-circuit indirect calorimetry for 22 h. Metabolisable energy for maintenance (MEm) and fasting energy expenditure (FEExp) were estimated by regression approach. Dry matter (DM) intake per kg0.75 was substantially reduced in llamas and sheep, but not in goats, on the LP...

  13. Anomalous nuclear fragments

    International Nuclear Information System (INIS)

    Karmanov, V.A.

    1983-01-01

    Experimental data are given, the status of anomalon problem is discussed, theoretical approaches to this problem are outlined. Anomalons are exotic objects formed following fragmentation of nuclei-targets under the effect of nuclei - a beam at the energy of several GeV/nucleon. These nuclear fragments have an anomalously large cross section of interaction and respectively, small free path, considerably shorter than primary nuclei have. The experimental daa are obtained in accelerators following irradiation of nuclear emulsions by 16 O, 56 Fe, 40 Ar beams, as well as propane by 12 C beams. The experimental data testify to dependence of fragment free path on the distance L from the point of the fragment formation. A decrease in the fragment free path is established more reliably than its dependence on L. The problem of the anomalon existence cannot be yet considered resolved. Theoretical models suggested for explanation of anomalously large cross sections of nuclear fragment interaction are variable and rather speculative

  14. Higher cytotoxicity of divalent antibody-toxins than monovalent antibody-toxins

    International Nuclear Information System (INIS)

    Won, JaeSeon; Nam, PilWon; Lee, YongChan; Choe, MuHyeon

    2009-01-01

    Recombinant antibody-toxins are constructed via the fusion of a 'carcinoma-specific' antibody fragment to a toxin. Due to the high affinity and high selectivity of the antibody fragments, antibody-toxins can bind to surface antigens on cancer cells and kill them without harming normal cells [L.H. Pai, J.K. Batra, D.J. FitzGerald, M.C. Willingham, I. Pastan, Anti-tumor activities of immunotoxins made of monoclonal antibody B3 and various forms of Pseudomonas exotoxin, Proc. Natl. Acad. Sci. USA 88 (1991) 3358-3362]. In this study, we constructed the antibody-toxin, Fab-SWn-PE38, with SWn (n = 3, 6, 9) sequences containing n-time repeated (G 4 S) between the Fab fragment and PE38 (38 kDa truncated form of Pseudomonas exotoxin A). The SWn sequence also harbored one cysteine residue that could form a disulfide bridge between two Fab-SWn-PE38 monomers. We assessed the cytotoxicity of the monovalent (Fab-SWn-PE38), and divalent ([Fab-SWn-PE38] 2 ) antibody-toxins. The cytotoxicity of the dimer against the CRL1739 cell line was approximately 18.8-fold higher than that of the monomer on the ng/ml scale, which was approximately 37.6-fold higher on the pM scale. These results strongly indicate that divalency provides higher cytotoxicity for an antibody-toxin.

  15. Radioimmunotherapy with Tenarad, a {sup 131}I-labelled antibody fragment targeting the extra-domain A1 of tenascin-C, in patients with refractory Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Aloj, Luigi [Istituto Nazionale Tumori ' ' Fondazione G. Pascale' ' - IRCCS, Struttura Complessa di Medicina Nucleare, Napoli (Italy); D' Ambrosio, Laura; Aurilio, Michela; Morisco, Anna; Caraco' , Corradina; Di Gennaro, Francesca; Lastoria, Secondo [Istituto Nazionale Tumori ' ' Fondazione G. Pascale' ' - IRCCS, Struttura Complessa Medicina Nucleare, Napoli (Italy); Frigeri, Ferdinando; Capobianco, Gaetana; Pinto, Antonio [Istituto Nazionale Tumori ' ' Fondazione G. Pascale' ' - IRCCS, Struttura Complessa di Ematologia Oncologica, Napoli (Italy); Giovannoni, Leonardo; Menssen, Hans D. [Philogen, SpA, Siena (Italy); Neri, Dario [Institute of Pharmaceutical Sciences, ETH, Zurich (Switzerland)

    2014-05-15

    The extra-domain A1 of tenascin-C (TC-A1) is highly expressed in the extracellular matrix of tumours and on newly formed blood vessels and is thus a valuable target for radionuclide therapy. Tenarad is a fully human miniantibody or small immunoprotein (SIP, molecular weight 80 kDa) labelled with {sup 131}I that is derived from a TC-A1-binding antibody. Previous phase I/II studies with a similar compound ({sup 131}I-L19SIP) used for radioimmunotherapy (RIT) have shown preliminary efficacy in a variety of cancer types. In this ongoing phase I/II trial, Tenarad was administered to patients with recurrent Hodgkin's lymphoma (HL) refractory to conventional treatments. Eight patients (four men, four women; age range 19 - 41) were enrolled between April 2010 and March 2011. All patients had received a median of three previous lines of chemotherapy (range three to six) and seven had also undergone autologous stem cell transplantation (ASCT) or bone marrow transplantation. In addition, seven patients received external beam radiation. All patients had nodal disease, constitutional B symptoms and some showed extranodal disease in skeletal bone (four patients), lung (three), liver (two) and spleen (one). Baseline assessments included whole-body FDG PET with contrast-enhanced CT and diagnostic Tenarad planar and SPECT studies. Patients were considered eligible to receive a therapeutic dose of Tenarad (2.05 GBq/m{sup 2}) if tumour uptake was more than four times higher than that of muscle. All patients were eligible and received the therapeutic dose of Tenarad. Only one patient developed grade 4 thrombocytopenia and leucocytopenia, requiring hospitalization and therapeutic intervention. All other patients had haematological toxicity of grade 3 or lower, which resolved spontaneously. At the first response assessment (4 - 6 weeks after therapy), one patient showed a complete response, one showed a partial response (PR) and five had disease stabilization (SD). Five patients

  16. Fission fragment angular momentum

    International Nuclear Information System (INIS)

    Frenne, D. De

    1991-01-01

    Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs

  17. Antigenic variability in bovine viral diarrhea virus (BVDV) isolates from alpaca (Vicugna pacos), llama (Lama glama) and bovines in Chile.

    Science.gov (United States)

    Aguirre, I M; Quezada, M P; Celedón, M O

    2014-01-31

    Llamas and alpacas are domesticated South American camelids (SACs) important to ancestral population in the Altiplano region, and to different communities where they have been introduced worldwide. These ungulates have shown to be susceptible to several livestock viral pathogens such as members of the Pestivirus genus and mainly to bovine viral diarrhea virus (BVDV). Seventeen Chilean BVDV isolates were analyzed by serum cross neutralization with samples obtained from five llama, six alpacas, three bovines, plus three reference strains belonging to different subgroups and genotypes. The objective was to describe antigenic differences and similarities among them. Antigenic comparison showed significant differences between different subgroups. Consequently, antigenic similarities were observed among isolates belonging to the same subgroup and also between isolates from different animal species belonging the same subgroup. Among the analyzed samples, one pair of 1b subgroup isolates showed significant antigenic differences. On the other hand, one pair of isolates from different subgroups (1b and 1j) shared antigenic similarities indicating antigenic relatedness. This study shows for the first time the presence of antigenic differences within BVDV 1b subgroup and antigenic similarities within 1j subgroup isolates, demonstrating that genetic differences within BVDV subgroups do not necessary corresponds to differences on antigenicity. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Evaluation of the effect of cooling and of the addition of collagenase on llama sperm DNA using toluidine blue.

    Science.gov (United States)

    Carretero, M I; Giuliano, S M; Casaretto, C I; Gambarotta, M C; Neild, D M

    2012-05-01

    The effect cryopreservation has on sperm chromatin condensation has been studied in many species but not in South American camelids. The objectives of this study were to evaluate with toluidine blue (TB) the effects of cooling and of adding collagenase on llama sperm DNA condensation. The optimum incubation time (30 s, 1.5 and 3 min) with a reducing agent (dithiothreitol) was also determined. When comparing cooled samples with the raw ejaculate, a significant increase in sperm showing a high degree of decondensation (TB positive) was observed (P = 0.005). A positive correlation was observed, both in raw and cooled semen, between sperm head morphological abnormalities observed in TB-stained cells and TB-positive sperm (highly decondensed DNA), but not with TB-intermediate spermatozoa (moderately decondensed DNA). No significant differences (P > 0.05) were observed in samples incubated with or without 0.1% collagenase. In cooled semen, but not in raw, a significant increase (P = 0.000) in reacted sperm (TB positive) was observed using 3-min incubation with 1% dithiothreitol (DTT). To conclude, cooling would seem to produce an increase in llama sperm chromatin decondensation. Also, 0.1% collagenase in H-TALP-BSA could be added to raw semen to aid its manipulation as it would not seem to increase DNA decondensation. © 2011 Blackwell Verlag GmbH.

  19. Radioimmunoimaging of experimental gliomas using radiolabelled monoclonal antibodies

    International Nuclear Information System (INIS)

    Glaessner, H.

    1986-01-01

    The biodistribution and tumour uptake of radiolabelled (131 I) glioma-seeking monoclonal antibodies (14 AC1) and their F(ab') 2 fragments were investigated in nude mice having received glioma transplants. Radioimmunoimaging by external scintigraphy at 48 and 96 hours pointed to a superior tumour localisation by the fragments that was clearly related to the dose. Wholebody determinations of the biokinetic behaviour led to the following results: Faster clearance anc more ready elimination from the blood pool for the fragments, preferential uptake in the tumour; intact antibodies; binding in the liver, spleen and lungs. The study confirmed the value of fragments of monoclonal antibodies in the diagnosis of tumours and pointed to the possibility of using intact monoclonal antibodies as carriers of radioisotopes and cytotoxic drugs within the scope of therapeutic programmes. (TRV) [de

  20. Meat quality attributes of the Longissimus lumborum muscle of the Kh'ara genotype of llama (Lama glama) reared extensively in northern Chile.

    Science.gov (United States)

    Mamani-Linares, L W; Gallo, C B

    2013-05-01

    Twenty male llama of the Kh'ara genotype, reared extensively in the north of Chile, were slaughtered at ages between 2 and 4 permanent teeth (2 to 3.5years) and analyses were carried out on the Longissimus lumborum muscle, including composition (moisture, fat, protein, ash, cholesterol, amino acids, fatty acid profile and collagen content) and meat quality parameters (pH, color, water holding capacity and Warner-Bratzler shear-force). Llama meat was characterized by a low cholesterol (39.04mg/100g) and intramuscular fat (1.56%) content, a total collagen content of 6.28mg/g, of which 20.28% was soluble collagen. Amino acid composition and fatty acid profile were similar to those found for beef finished on forage. Llama meat showed a low n-6/n-3 (4.69) and hypocholesterolemic/hypercholesterolemic (1.55) ratio and acceptable values of DFA (65.78%). Quality parameters in llama Longissimus muscle were within the ranges reported for more traditional meats such as beef and lamb. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Relevamiento serológico de anticuerpos contra enfermedades virales de interés sanitario en llamas (Lama glama de la provincia de Jujuy, Argentina

    Directory of Open Access Journals (Sweden)

    Elena S Barbieri

    Full Text Available Las poblaciones de llamas de Argentina se concentran principalmente en la provincia de Jujuy; su explotación representa un importante recurso económico de las comunidades altoandinas. El objetivo de este trabajo fue evaluar la seroprevalencia de anticuerpos contra algunos agentes virales asociados a enfermedades de impacto productivo en rodeos de llamas de Jujuy. Se analizaron 349 sueros de llamas adultas de 6 departamentos de la puna jujeña ubicados por encima de los 3300 msnm. Se obtuvo una prevalencia del 100 % para rotavirus grupo A y del 70 % para el virus parainfluenza-3 bovino, mientras que no se detectaron reactores para herpesvirus bovino 1, virus de la diarrea viral bovina, influenza A humana (H1N1 e influenza equina (H3N8. Los resultados obtenidos confirman la amplia distribución de rotavirus y virus parainfluenza y la baja susceptibilidad a herpesvirus y pestivirus en las tropas de llamas de la puna jujeña.

  2. Clinical experience in humans with radiolabeled antibody for tumor detection

    International Nuclear Information System (INIS)

    Morrison, R.T.; Lyster, D.M.; Szasz, I.; Alcorn, L.N.; Huckell, V.F.; Rhodes, B.; Breslow, K.; Burchiel, S.

    1982-01-01

    I-131 and Tc-99m labeled polyclonal or monoclonal antibody and fragments of antibody, specific to human chorionic gonadotropin (hCG) or to a melanoma cell surface antigen (MCSA) were injected into proven cancer patients. Using standard homeostasis parameters, and scanning techniques, the safety and efficacy of each antibody was evaluated. Antibody fragments were expected to clear faster from the circulation allowing for earlier imaging and a better target-to-non-target ratio. The technetium label may perturb the antiboby's kinetics so that clearance is more rapid for both whole antibody and fragments. After a statistical evaluation of all parameters measured pre and post injection it was concluded that no acute toxicity reactions were present in any patient studied. Scan results were not acceptable for a tumor detecting procedure used in routine practice. Tumor upake was seen in less than 10% of scans

  3. Sarcocystis spp. in llamas (Lama glama) in Southern Bolivia: a cross sectional study of the prevalence, risk factors and loss in income caused by carcass downgrades.

    Science.gov (United States)

    Rooney, A L; Limon, G; Vides, H; Cortez, A; Guitian, J

    2014-10-01

    Llamas (Lama glama) are intermediate hosts of the protozoan parasite Sarcocystis spp. This parasite is described as causing economic losses in the production of llama meat in South America. The aim of this study was to estimate prevalence, identify risk factors and explore spatial patterns of Sarcocystis in llamas in an area of the Bolivian High Plateau including estimating financial losses due to carcass downgrades as a result of the presence of Sarcocystis cysts. Information was collected from a local abattoir between 2006 and 2011 on 1196 llamas. Sarcocystis status was determined at meat inspection where any carcasses with one or more visible cysts were deemed Sarcocystis positive. A high prevalence was found, estimated to vary between 23.4% (95% CI 16.6-30.1) in 2007 and 50.3% (95% CI 44.4-56.3) in 2011. Period prevalence between 2006 and 2011 was estimated at 34.1% (95% CI 31.4-36.8). Age, sex and type (analogous to breed) were identified as risk factors for Sarcocystis using a mixed-effects logistic regression model adjusting for clustering by community and owner. Llamas over 4.5 years of age had an increased odds of being Sarcocystis positive (OR 19.31, 95% CI 9.10-40.98) as well as females (OR 1.75, 95% CI 1.13-2.68) and long haired type llamas (OR 1.90, 95% CI 1.26-2.87). An interaction between age and sex was detected indicating that the increased odds of disease from the youngest age group to the 2.5-4.5 years group was much more pronounced in females than in males. Spatial patterns of Sarcocystis were explored at district level by means of Standardised Morbidity Ratios and some spatial heterogeneity was revealed. Estimates of financial loss due to the disease were calculated using the difference in price paid for Sarcocystis positive and negative meat. Loss due to Sarcocystis varied per year but could be up to 20% of the annual income generated through the abattoir by sale of meat. Overall this study shows a high prevalence of Sarcocystis in the study

  4. 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 ...

  5. Evaluation of two platelet-rich plasma processing methods and two platelet-activation techniques for use in llamas and alpacas.

    Science.gov (United States)

    Semevolos, Stacy A; Youngblood, Cori D; Grissom, Stephanie K; Gorman, M Elena; Larson, Maureen K

    2016-11-01

    OBJECTIVE To evaluate 2 processing methods (commercial kit vs conical tube centrifugation) for preparing platelet rich plasma (PRP) for use in llamas and alpacas. SAMPLES Blood samples (30 mL each) aseptically collected from 6 healthy llamas and 6 healthy alpacas. PROCEDURES PRP was prepared from blood samples by use of a commercial kit and by double-step conical tube centrifugation. A CBC was performed for blood and PRP samples. Platelets in PRP samples were activated by means of a freeze-thaw method with or without 23mM CaCl 2 , and concentrations of platelet-derived growth factor-BB and transforming growth factor-β 1 were measured. Values were compared between processing methods and camelid species. RESULTS Blood CBC values for llamas and alpacas were similar. The commercial kit yielded a significantly greater degree of platelet enrichment (mean increase, 8.5 fold vs 2.8 fold) and WBC enrichment (mean increase, 3.7 fold vs 1.9 fold) than did conical tube centrifugation. Llamas had a significantly greater degree of platelet enrichment than alpacas by either processing method. No difference in WBC enrichment was identified between species. Concentrations of both growth factors were significantly greater in PRP samples obtained by use of the commercial kit versus those obtained by conical tube centrifugation. CONCLUSIONS AND CLINICAL RELEVANCE For blood samples from camelids, the commercial kit yielded a PRP product with a higher platelet and WBC concentration than achieved by conical tube centrifugation. Optimal PRP platelet and WBC concentrations for various applications need to be determined for llamas and alpacas.

  6. String fragmentation; La fragmentation des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, H.J.; Werner, K. [Laboratoire de Physique Subatomique et des Technologies Associees - SUBATECH, Centre National de la Recherche Scientifique, 44 - Nantes (France)

    1997-10-01

    The classical string model is used in VENUS as a fragmentation model. For the soft domain simple 2-parton strings were sufficient, whereas for higher energies up to LHC, the perturbative regime of the QCD gives additional soft gluons, which are mapped on the string as so called kinks, energy singularities between the leading partons. The kinky string model is chosen to handle fragmentation of these strings by application of the Lorentz invariant area law. The `kinky strings` model, corresponding to the perturbative gluons coming from pQCD, takes into consideration this effect by treating the partons and gluons on the same footing. The decay law is always the Artru-Menessier area law which is the most realistic since it is invariant to the Lorentz and gauge transformations. For low mass strings a manipulation of the rupture point is necessary if the string corresponds already to an elementary particle determined by the mass and the flavor content. By means of the fragmentation model it will be possible to simulate the data from future experiments at LHC and RHIC 3 refs.

  7. Hybrid IgG4/IgG4 Fc antibodies form upon 'Fab-arm' exchange as demonstrated by SDS-PAGE or size-exclusion chromatography

    NARCIS (Netherlands)

    Rispens, Theo; den Bleker, Tamara H.; Aalberse, Rob C.

    2010-01-01

    Human IgG4 antibodies are dynamic molecules that in vivo exchange half-molecules to become bispecific antibodies. Here we show that IgG4 antibodies and IgG4 Fc fragments similarly exchange resulting in hybrid antibodies (a single Fab + Fc) with a molecular weight of ca. 100 kDa. These antibodies can

  8. Dimensional crossover in fragmentation

    Science.gov (United States)

    Sotolongo-Costa, Oscar; Rodriguez, Arezky H.; Rodgers, G. J.

    2000-11-01

    Experiments in which thick clay plates and glass rods are fractured have revealed different behavior of fragment mass distribution function in the small and large fragment regions. In this paper we explain this behavior using non-extensive Tsallis statistics and show how the crossover between the two regions is caused by the change in the fragments’ dimensionality during the fracture process. We obtain a physical criterion for the position of this crossover and an expression for the change in the power-law exponent between the small and large fragment regions. These predictions are in good agreement with the experiments on thick clay plates.

  9. Antiparietal cell antibody test

    Science.gov (United States)

    APCA; Anti-gastric parietal cell antibody; Atrophic gastritis - anti-gastric parietal cell antibody; Gastric ulcer - anti-gastric parietal cell antibody; Pernicious anemia - anti-gastric parietal cell antibody; ...

  10. Adaptive functional specialisation of architectural design and fibre type characteristics in agonist shoulder flexor muscles of the llama, Lama glama

    Science.gov (United States)

    Graziotti, Guillermo H; Chamizo, Verónica E; Ríos, Clara; Acevedo, Luz M; Rodríguez-Menéndez, J M; Victorica, C; Rivero, José-Luis L

    2012-01-01

    Like other camelids, llamas (Lama glama) have the natural ability to pace (moving ipsilateral limbs in near synchronicity). But unlike the Old World camelids (bactrian and dromedary camels), they are well adapted for pacing at slower or moderate speeds in high-altitude habitats, having been described as good climbers and used as pack animals for centuries. In order to gain insight into skeletal muscle design and to ascertain its relationship with the llama’s characteristic locomotor behaviour, this study examined the correspondence between architecture and fibre types in two agonist muscles involved in shoulder flexion (M. teres major – TM and M. deltoideus, pars scapularis – DS and pars acromialis – DA). Architectural properties were found to be correlated with fibre-type characteristics both in DS (long fibres, low pinnation angle, fast-glycolytic fibre phenotype with abundant IIB fibres, small fibre size, reduced number of capillaries per fibre and low oxidative capacity) and in DA (short fibres, high pinnation angle, slow-oxidative fibre phenotype with numerous type I fibres, very sparse IIB fibres, and larger fibre size, abundant capillaries and high oxidative capacity). This correlation suggests a clear division of labour within the M. deltoideus of the llama, DS being involved in rapid flexion of the shoulder joint during the swing phase of the gait, and DA in joint stabilisation during the stance phase. However, the architectural design of the TM muscle (longer fibres and lower fibre pinnation angle) was not strictly matched with its fibre-type characteristics (very similar to those of the postural DA muscle). This unusual design suggests a dual function of the TM muscle both in active flexion of the shoulder and in passive support of the limb during the stance phase, pulling the forelimb to the trunk. This functional specialisation seems to be well suited to a quadruped species that needs to increase ipsilateral stability of the limb during the

  11. Functionally fused antibodies--a novel adjuvant fusion system

    DEFF Research Database (Denmark)

    Larsen, Martin; Jensen, Kim Bak; Christensen, Peter Astrup

    2008-01-01

    Antibodies capable of recognizing key molecular targets isolated e.g. by phage display technology have been used in the pursuit of new and improved therapies for prevalent human diseases. These approaches often take advantage of non-immunogenic antibody fragments to achieve specific toxin-, radio...

  12. Embedded Fragments Registry (EFR)

    Data.gov (United States)

    Department of Veterans Affairs — In 2009, the Department of Defense estimated that approximately 40,000 service members who served in OEF/OIF may have embedded fragment wounds as the result of small...

  13. Physics of projectile fragments

    International Nuclear Information System (INIS)

    Minamisono, Tadanori

    1982-01-01

    This is a study report on the polarization phenomena of the projectile fragments produced by heavy ion reactions, and the beta decay of fragments. The experimental project by using heavy ions with the energy from 50 MeV/amu to 250 MeV/amu was designed. Construction of an angle-dispersion spectrograph for projectile fragments was proposed. This is a two-stage spectrograph. The first stage is a QQDQQ type separator, and the second stage is QDQD type. Estimation shows that Co-66 may be separated from the nuclei with mass of 65 and 67. The orientation of fragments can be measured by detecting beta-ray. The apparatus consists of a uniform field magnet, an energy absorber, a stopper, a RF coil and a beta-ray hodoscope. This system can be used for not only this purpose but also for the measurement of hyperfine structure. (Kato, T.)

  14. Fragmentation Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The fragmentation model combines patch size and patch continuity with diversity of vegetation types per patch and rarity of vegetation types per patch. A patch was...

  15. Stone fragmentation by ultrasound

    Indian Academy of Sciences (India)

    Unknown

    In the present work, enhancement of the kidney stone fragmentation by using ultrasound is studied. The cavi- ... ment system like radiation pressure balance, the power is given by ... Thus the bubble size has direct relationship with its life and.

  16. Fragment capture device

    Science.gov (United States)

    Payne, Lloyd R.; Cole, David L.

    2010-03-30

    A fragment capture device for use in explosive containment. The device comprises an assembly of at least two rows of bars positioned to eliminate line-of-sight trajectories between the generation point of fragments and a surrounding containment vessel or asset. The device comprises an array of at least two rows of bars, wherein each row is staggered with respect to the adjacent row, and wherein a lateral dimension of each bar and a relative position of each bar in combination provides blockage of a straight-line passage of a solid fragment through the adjacent rows of bars, wherein a generation point of the solid fragment is located within a cavity at least partially enclosed by the array of bars.

  17. DNA fragmentation in spermatozoa

    DEFF Research Database (Denmark)

    Rex, A S; Aagaard, J.; Fedder, J

    2017-01-01

    Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated....... In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling...... (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage...

  18. Fragment Impact Toolkit (FIT)

    Energy Technology Data Exchange (ETDEWEB)

    Shevitz, Daniel Wolf [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Key, Brian P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garcia, Daniel B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-05

    The Fragment Impact Toolkit (FIT) is a software package used for probabilistic consequence evaluation of fragmenting sources. The typical use case for FIT is to simulate an exploding shell and evaluate the consequence on nearby objects. FIT is written in the programming language Python and is designed as a collection of interacting software modules. Each module has a function that interacts with the other modules to produce desired results.

  19. Antibody-Based Immunotoxins for the Treatment of Cancer

    OpenAIRE

    Nurit Becker; Itai Benhar

    2012-01-01

    Antibody-based immunotoxins comprise an important group in targeted cancer therapeutics. These chimeric proteins are a form of biological guided missiles that combine a targeting moiety with a potent effector molecule. The targeting moiety is mostly a monoclonal antibody (MAb) or a recombinant antibody-based fragment that confers target specificity to the immunotoxin. The effector domain is a potent protein toxin of bacterial or plant origin, which, following binding to the target cells, unde...

  20. First llama (Lama glama) pregnancy obtained after in vitro fertilization and in vitro culture of gametes from live animals.

    Science.gov (United States)

    Trasorras, V; Baca Castex, C; Alonso, A; Giuliano, S; Santa Cruz, R; Arraztoa, C; Chaves, G; Rodríguez, D; Neild, D; Miragaya, M

    2014-07-01

    The aim of this study was to evaluate the developmental competence and pregnancy rate of llama hatched blastocysts produced in vitro using gametes from live animals and two different culture conditions. Fifteen adult females were superstimulated with 1500 IU of eCG, eleven (73%) responded to the treatment and were used as oocyte donors. Follicular aspiration was conducted by flank laparotomy. Semen collections were performed under general anesthesia by electroejaculation of the male. Sixty-six COCs were recovered from 77 aspirated follicles (86% recovery) and were randomly placed in Fertil-TALP microdroplets with the sperm suspension (20 × 10(6)live spermatozoa/ml). After 24 h, they were placed in SOFaa medium supplemented with FCS and randomly assigned to one of two culture conditions. Culture condition 1 (CC1) consisted of 6 days of culture (n=28) and culture condition 2 (CC2) consisted of renewing the culture medium every 48 h (n=35). In CC1, the blastocyst rate was 36% (10/28) and the hatched blastocyst rate was 28% (8/28) whereas in CC2, the blastocyst rate was 34% (12/35) and the hatched blastocyst rate was 20% (7/35) (p>0.05). No pregnancies were obtained after embryo transfer (ET) of CC1 blastocysts (0/8) while one pregnancy was obtained (1/7) after transferring a hatched blastocyst from CC2. Forty-two days after the ET, the pregnancy was lost. This study represents the first report of a pregnancy in the llama after intrauterine transfer of embryos produced by in vitro fertilization using gametes from live animals. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Substrate and O2 fluxes during rest and exercise in a high-altitude-adapted animal, the llama

    International Nuclear Information System (INIS)

    Hochachka, P.W.; Mommsen, T.P.; Jones, J.H.; Taylor, C.R.

    1987-01-01

    Llamas were trained to exercise on a treadmill at graded speeds. O 2 uptake values at rest, at modest exercise (ME) and at heavy exercise were 0.069, 0.297, and 0.594 ml O 2 ·kg -1 ·s -1 . Corresponding values for cardiac output were 1.64, 4.39, and 6.85 ml·kg -1 ·s -1 . Palmitate, glucose, and lactate replacement rates (R a values) were determined at these varying work rates using a single-bolus injection of 14 C- or 3 H-labeled metabolites, two at a time. During ME, the R a values for glucose and palmitate increased about twofold but showed no further increase when exercised intensity was increased about twofold. In contrast to these results, R a values for lactate increased much more with increasing work rate. A combination of increased perfusion (increased cardiac output) and increased lactate availability (increased plasma concentration) could account for the lactate R a data. During prolonged ME, the R a for lactate decreased because lactate availability decreased; concurrently, both the plasma free fatty acid availability and the R a values for pamlitate greatly increased. Because O 2 carrying capacity is low in the llama (as in all high-altitude-adapted mammals), a given level of exercise required exaggerated increases in cardiac output. As a result, the flux rates of palmitate, glucose, and lactate through the plasma compartment could readily account for O 2 flux rates even at relatively high sustainable rates of exercise

  2. 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.

  3. Antibody Engineering and Therapeutics

    Science.gov (United States)

    Almagro, Juan Carlos; Gilliland, Gary L; Breden, Felix; Scott, Jamie K; Sok, Devin; Pauthner, Matthias; Reichert, Janice M; Helguera, Gustavo; Andrabi, Raiees; Mabry, Robert; Bléry, Mathieu; Voss, James E; Laurén, Juha; Abuqayyas, Lubna; Barghorn, Stefan; Ben-Jacob, Eshel; Crowe, James E; Huston, James S; Johnston, Stephen Albert; Krauland, Eric; Lund-Johansen, Fridtjof; Marasco, Wayne A; Parren, Paul WHI; Xu, Kai Y

    2014-01-01

    The 24th Antibody Engineering & Therapeutics meeting brought together a broad range of participants who were updated on the latest advances in antibody research and development. Organized by IBC Life Sciences, the gathering is the annual meeting of The Antibody Society, which serves as the scientific sponsor. Preconference workshops on 3D modeling and delineation of clonal lineages were featured, and the conference included sessions on a wide variety of topics relevant to researchers, including systems biology; antibody deep sequencing and repertoires; the effects of antibody gene variation and usage on antibody response; directed evolution; knowledge-based design; antibodies in a complex environment; polyreactive antibodies and polyspecificity; the interface between antibody therapy and cellular immunity in cancer; antibodies in cardiometabolic medicine; antibody pharmacokinetics, distribution and off-target toxicity; optimizing antibody formats for immunotherapy; polyclonals, oligoclonals and bispecifics; antibody discovery platforms; and antibody-drug conjugates. PMID:24589717

  4. Antibody Derived Peptides for Detection of Ebola Virus Glycoprotein.

    Directory of Open Access Journals (Sweden)

    Luis Mario Rodríguez-Martínez

    Full Text Available Current Ebola virus (EBOV detection methods are costly and impractical for epidemic scenarios. Different immune-based assays have been reported for the detection and quantification of Ebola virus (EBOV proteins. In particular, several monoclonal antibodies (mAbs have been described that bind the capsid glycoprotein (GP of EBOV GP. However, the currently available platforms for the design and production of full-length mAbs are cumbersome and costly. The use of antibody fragments, rather than full-length antibodies, might represent a cost-effective alternative for the development of diagnostic and possibly even therapeutic alternatives for EBOV.We report the design and expression of three recombinant anti-GP mAb fragments in Escherichia coli cultures. These fragments contained the heavy and light variable portions of the three well-studied anti-GP full-length mAbs 13C6, 13F6, and KZ52, and are consequently named scFv-13C6, scFv-13F6, and Fab-KZ52, respectively. All three fragments exhibited specific anti-GP binding activity in ELISA experiments comparable to that of full-length anti-GP antibodies (i.e., the same order of magnitude and they are easily and economically produced in bacterial cultures.Antibody fragments might represent a useful, effective, and low cost alternative to full-length antibodies in Ebola related capture and diagnostics applications.

  5. Fragmentation of relativistic nuclei

    International Nuclear Information System (INIS)

    Cork, B.

    1975-06-01

    Nuclei with energies of several GeV/n interact with hadrons and produce fragments that encompass the fields of nuclear physics, meson physics, and particle physics. Experimental results are now available to explore problems in nuclear physics such as the validity of the shell model to explain the momentum distribution of fragments, the contribution of giant dipole resonances to fragment production cross sections, the effective Coulomb barrier, and nuclear temperatures. A new approach to meson physics is possible by exploring the nucleon charge-exchange process. Particle physics problems are explored by measuring the energy and target dependence of isotope production cross sections, thus determining if limiting fragmentation and target factorization are valid, and measuring total cross sections to determine if the factorization relation, sigma/sub AB/ 2 = sigma/sub AA/ . sigma/sub BB/, is violated. Also, new experiments have been done to measure the angular distribution of fragments that could be explained as nuclear shock waves, and to explore for ultradense matter produced by very heavy ions incident on heavy atoms. (12 figures, 2 tables)

  6. Current diagnostic efficacy of Tc-99m-labeled antitumor antibodies

    International Nuclear Information System (INIS)

    Morrison, R.T.; Lyster, D.M.; Szasz, I.; Alcorn, L.N.; Rhodes, B.A.; Breslow, K.; Burchiel, S.W.

    1983-01-01

    The authors have recently evaluated technetium 99 labeled antibodies specific to human chorionic gonadotropin (hCG) for the in vivo detection of a variety of human tumors. Both mouse monoclonal and sheep polyclonal antibodies were evaluated in this study. Another antibody specific to hCG studied, is an antigen-agglutinating monoclonal F(ab') 2 fragment. Some preliminary results are reported

  7. Fungal Glucosylceramide-Specific Camelid Single Domain Antibodies Are Characterized by Broad Spectrum Antifungal Activity

    Directory of Open Access Journals (Sweden)

    Barbara De Coninck

    2017-06-01

    Full Text Available Chemical crop protection is widely used to control plant diseases. However, the adverse effects of pesticide use on human health and environment, resistance development and the impact of regulatory requirements on the crop protection market urges the agrochemical industry to explore innovative and alternative approaches. In that context, we demonstrate here the potential of camelid single domain antibodies (VHHs generated against fungal glucosylceramides (fGlcCer, important pathogenicity factors. To this end, llamas were immunized with purified fGlcCer and a mixture of mycelium and spores of the fungus Botrytis cinerea, one of the most important plant pathogenic fungi. The llama immune repertoire was subsequently cloned in a phage display vector to generate a library with a diversity of at least 108 different clones. This library was incubated with fGlcCer to identify phages that bind to fGlcCer, and VHHs that specifically bound fGlcCer but not mammalian or plant-derived GlcCer were selected. They were shown to inhibit the growth of B. cinerea in vitro, with VHH 41D01 having the highest antifungal activity. Moreover, VHH 41D01 could reduce disease symptoms induced by B. cinerea when sprayed on tomato leaves. Based on all these data, anti-fGlcCer VHHs show the potential to be used as an alternative approach to combat fungal plant diseases.

  8. Land fragmentation and production diversification

    NARCIS (Netherlands)

    Ciaian, Pavel; Guri, Fatmir; Rajcaniova, Miroslava; Drabik, Dusan; Paloma, Sergio Gomez Y.

    2018-01-01

    We analyze the impact of land fragmentation on production diversification in rural Albania. Albania represents a particularly interesting case for studying land fragmentation as the fragmentation is a direct outcome of land reforms. The results indicate that land fragmentation is an important driver

  9. Heavy fragment radioactivity

    International Nuclear Information System (INIS)

    Silisteanu, I.

    1991-06-01

    The effect of collective mode excitation in heavy fragment radioactivity (HFR) is explored and discussed in the light of current experimental data. It is found that the coupling and resonance effects in fragment interaction and also the proper angular momentum effects may lead to an important enhancing of the emission process. New useful procedures are proposed for the study of nuclear decay properties. The relations between different decay processes are investigated in detail. We are also trying to understand and explain in a unified way the reaction mechanisms in decay phenomena. (author). 17 refs, 4 figs, 3 tabs

  10. Radiometallating antibodies and autoantigenic peptides

    International Nuclear Information System (INIS)

    Mercer-Smith, J.A.; Lewis, D.; Cole, D.A.; Newmyer, S.L.; Schulte, L.D.; Mixon, P.L.; Schreyer, S.A.; Burns, T.P.; Roberts, J.C.; Figard, S.D.; McCormick, D.J.; Lennon, V.A.; Hayashi, M.; Lavallee, D.K.

    1991-01-01

    We have developed methods to radiolabel large molecules, using porphyrins as bifunctional chelating agents for radiometals. The porphyrins are substituted with an N- benzyl group to activate them for radiometallation under mild reaction conditions. Porphyrins that have one functional group for covalent attachment to other molecules cannot cause crosslinking. We have examined the labeling chemistry for antibodies and have developed methods to label smaller biologically active molecules, such as autoantigenic peptides (fragments of the acetylcholine receptor), which are pertinent to myasthenia gravis research. The methods of covalent attachment of these bifunctional chelating agents to large molecules, the radiometallation chemistry, and biological characterization of the radiolabeled compounds will be discussed

  11. Analysis of mitochondrial DNA in Bolivian llama, alpaca and vicuna populations: a contribution to the phylogeny of the South American camelids.

    Science.gov (United States)

    Barreta, J; Gutiérrez-Gil, B; Iñiguez, V; Saavedra, V; Chiri, R; Latorre, E; Arranz, J J

    2013-04-01

    The objectives of this work were to assess the mtDNA diversity of Bolivian South American camelid (SAC) populations and to shed light on the evolutionary relationships between the Bolivian camelids and other populations of SACs. We have analysed two different mtDNA regions: the complete coding region of the MT-CYB gene and 513 bp of the D-loop region. The populations sampled included Bolivian llamas, alpacas and vicunas, and Chilean guanacos. High levels of genetic diversity were observed in the studied populations. In general, MT-CYB was more variable than D-loop. On a species level, the vicunas showed the lowest genetic variability, followed by the guanacos, alpacas and llamas. Phylogenetic analyses performed by including additional available mtDNA sequences from the studied species confirmed the existence of the two monophyletic clades previously described by other authors for guanacos (G) and vicunas (V). Significant levels of mtDNA hybridization were found in the domestic species. Our sequence analyses revealed significant sequence divergence within clade G, and some of the Bolivian llamas grouped with the majority of the southern guanacos. This finding supports the existence of more than the one llama domestication centre in South America previously suggested on the basis of archaeozoological evidence. Additionally, analysis of D-loop sequences revealed two new matrilineal lineages that are distinct from the previously reported G and V clades. The results presented here represent the first report on the population structure and genetic variability of Bolivian camelids and may help to elucidate the complex and dynamic domestication process of SAC populations. © 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.

  12. PELE fragmentation dynamics

    NARCIS (Netherlands)

    Verreault, J.; Hinsberg, N.P. van; Abadjieva, E.

    2013-01-01

    An analytical model that describes the PELE fragmentation dynamics is presented and compared with experimental results from literature. The model accounts for strong shock effects and detailed interactions taking place between the filling – the inner core of the ammunition – and the target

  13. Cryobiology of coral fragments.

    Science.gov (United States)

    Hagedorn, Mary; Farrell, Ann; Carter, Virginia L

    2013-02-01

    Around the world, coral reefs are dying due to human influences, and saving habitat alone may not stop this destruction. This investigation focused on the biological processes that will provide the first steps in understanding the cryobiology of whole coral fragments. Coral fragments are a partnership of coral tissue and endosymbiotic algae, Symbiodinium sp., commonly called zooxanthellae. These data reflected their separate sensitivities to chilling and a cryoprotectant (dimethyl sulfoxide) for the coral Pocillopora damicornis, as measured by tissue loss and Pulse Amplitude Modulated fluorometry 3weeks post-treatment. Five cryoprotectant treatments maintained the viability of the coral tissue and zooxanthellae at control values (1M dimethyl sulfoxide at 1.0, 1.5 and 2.0h exposures, and 1.5M dimethyl sulfoxide at 1.0 and 1.5h exposures, P>0.05, ANOVA), whereas 2M concentrations did not (Pzooxanthellae. During the winter when the fragments were chilled, the coral tissue remained relatively intact (∼25% loss) post-treatment, but the zooxanthellae numbers in the tissue declined after 5min of chilling (Pzooxanthellae numbers declined in response to chilling alone (P0.05, ANOVA), but it did not protect against the loss of zooxanthellae (Pzooxanthellae are the most sensitive element in the coral fragment complex and future cryopreservation protocols must be guided by their greater sensitivity. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Fragments of the Past

    OpenAIRE

    Peter Szende; Annie Holcombe

    2016-01-01

    With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  15. Synthesis of arabinoxylan fragments

    DEFF Research Database (Denmark)

    Underlin, Emilie Nørmølle; Böhm, Maximilian F.; Madsen, Robert

    , or production of commercial chemicals which are mainly obtained from fossil fuels today.The arbinoxylan fragments have a backbone of β-1,4-linked xylans with α-L-arabinose units attached at specific positions. The synthesis ultilises an efficient synthetic route, where all the xylan units can be derived from D...

  16. Fragmented Work Stories

    DEFF Research Database (Denmark)

    Humle, Didde Maria; Reff Pedersen, Anne

    2015-01-01

    stories. We argue that meaning by story making is not always created by coherence and causality; meaning is created by different types of fragmentation: discontinuities, tensions and editing. The objective of this article is to develop and advance antenarrative practice analysis of work stories...

  17. Fragments of the Past

    Directory of Open Access Journals (Sweden)

    Peter Szende

    2016-10-01

    Full Text Available With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  18. Kotai Antibody Builder: automated high-resolution structural modeling of antibodies.

    Science.gov (United States)

    Yamashita, Kazuo; Ikeda, Kazuyoshi; Amada, Karlou; Liang, Shide; Tsuchiya, Yuko; Nakamura, Haruki; Shirai, Hiroki; Standley, Daron M

    2014-11-15

    Kotai Antibody Builder is a Web service for tertiary structural modeling of antibody variable regions. It consists of three main steps: hybrid template selection by sequence alignment and canonical rules, 3D rendering of alignments and CDR-H3 loop modeling. For the last step, in addition to rule-based heuristics used to build the initial model, a refinement option is available that uses fragment assembly followed by knowledge-based scoring. Using targets from the Second Antibody Modeling Assessment, we demonstrate that Kotai Antibody Builder generates models with an overall accuracy equal to that of the best-performing semi-automated predictors using expert knowledge. Kotai Antibody Builder is available at http://kotaiab.org standley@ifrec.osaka-u.ac.jp. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Detection of the matrix metalloproteinases MMP-2 and MMP-9 and tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2 in llama (Lama glama) oviduct.

    Science.gov (United States)

    Zampini, R; Argañaraz, M E; Miceli, D C; Apichela, S A

    2014-06-01

    Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are involved in several reproductive events like oocyte-spermatozoa interaction and semen liquefaction. In order to study their role in the llama oviductal reproductive process, MMP activity in oviductal fluid (OF) was assayed. Considering that llama genome sequences are partially known, a strategy to procure cDNA sequences of MMP-2, MMP-9, TIMP-1 and TIMP-2 was designed. Afterwards, their expression patterns in the different llama oviductal segments were assayed. Gelatine zymograms detected 62 and 94 kDa protease activities that matched MMP-2 and pro-MMP-9, respectively. Expression pattern analysis showed that MMP and TIMP mRNAs were present in ampulla, isthmus, utero-tubal junction (UTJ) and papilla. Altogether, these findings support the argument that MMPs/TIMPs are produced in the oviduct and secreted into the oviductal lumen. Our results encourage further studies to elucidate the role of these proteins in reproductive oviductal events. © 2014 Blackwell Verlag GmbH.

  20. Cationization increases brain distribution of an amyloid-beta protofibril selective F(ab')2 fragment

    OpenAIRE

    Syvänen, Stina; Edén, Desireé; Sehlin, Dag

    2017-01-01

    Antibodies and fragments thereof are, because of high selectivity for their targets, considered as potential therapeutics and biomarkers for several neurological disorders. However, due to their large molecular size, antibodies/fragments do not easily penetrate into the brain. The aim of the present study was to improve the brain distribution via adsorptive-mediated transcytosis of an amyloid-beta (A beta) protofibril selective F(ab')2 fragment (F(ab')2-h158). F(ab')2-h158 was cationized to d...

  1. Generation of HER2 monoclonal antibodies using epitopes of a rabbit polyclonal antibody.

    Science.gov (United States)

    Hu, Francis Jingxin; Uhlen, Mathias; Rockberg, Johan

    2014-01-25

    One of the issues in using polyclonal antibodies is the limited amount of reagent available from an immunisation, leading to batch-to-batch variation and difficulties in obtaining the same antibody performance when the same antigen is re-immunised into several separate animals. This led to the development of hybridoma technology allowing, at least theoretically, for an unlimited production of a specific binder. Nevertheless, polyclonal antibodies are widely used in research and diagnostics and there exists a need for robust methods to convert a polyclonal antibody with good binding performance into a renewable monoclonal with identical or similar binding specificity. Here we have used precise information regarding the functional recognition sequence (epitope) of a rabbit polyclonal antibody with attractive binding characteristics as the basis for generation of a renewable mouse monoclonal antibody. First, the original protein fragment antigen was used for immunisation and generation of mouse hybridoma, without obtaining binders to the same epitope region. Instead a peptide designed using the functional epitope and structural information was synthesised and used for hybridoma production. Several of the monoclonal antibodies generated were found to have similar binding characteristics to those of the original polyclonal antibody. These monoclonal antibodies detected native HER2 on cell lines and were also able to stain HER2 in immunohistochemistry using xenografted mice, as well as human normal and cancer tissues. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. [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.

  3. The materno-fetal interface in llama (Lama guanicoe glama A interface materno-fetal em lhamas (Lama guanicoe glama

    Directory of Open Access Journals (Sweden)

    David M. Iturrizaga

    2007-06-01

    Full Text Available Samples from 9 llamas (28 through 36 weeks of gestation were collected and fixed in 4% buffered paraformaldehyde (light microscopy and in 2.5% buffered glutaraldehyde (transmission and scanning electron microscopy. The material was processed in paraplast and slides (5mm were stained with HE, PAS, Masson-Trichrome, acid phosphatase and Perl's. The uteroferrin was immunolocalized. The results show that llama placenta is chorioallantoic, diffuse, folded and epitheliochorial, and the fetus is covered with an epidermal membrane. The trophoblast cells have variable morphology: cubic, rounded and triangular cells, with cytoplasm containing PAS-positive granules. Binucleated cells with large cytoplasm and rounded nuclei, as well as giant trophoblastic cells with multiple nuclei were also observed. Numerous blood vessels were observed beneath the cells of the uterine epithelium and around the chorionic subdivided branches. Glandular activity was shown by PAS, Perl's, and acid phosphatase positive reactions in the cytoplasm and glandular lumen, and by immunolocalization of the uteroferrin in the glandular epithelium. The uterine glands open in spaces formed by the areoles, which are filled by PAS-positive material. The llama fetus was covered by the epidermal membrane, composed of stratified epithelium, with up to seven layers of mono-, bi- or trinucleated cells. The high level of maternal and fetal vascularization surfaces indicates an intense exchange of substances across both surfaces. The metabolic activity shown in the uterine glands suggests an adaptation of the gestation to the high altitudes of the natural habitat of this species.Fragmentos da placenta de 9 animais (28-36 semanas de gestação, provenientes do Instituto Veterinario de Investigaciones Tropicales y de Altura (IVITA, Cusco-Peru, e da Universidad del Altiplano (UNA, Puno-Peru, foram colhidos e fixados em paraformoldeído 4% em PBS para microscopia de luz e em glutaraldeido em 2,5% PBS

  4. Control del avance del frente de llama en el lecho de sinterización de minerales de hierro

    Directory of Open Access Journals (Sweden)

    Cores, A.

    2010-06-01

    Full Text Available A sintering pan of 40 cm cubed is loaded with a mixture of iron ores, limestone and coke weighing 110 kg in a sintering pilot plant. In this sintering pan, a series of thermocouples have been introduced at different depths. Tests have been carried out to study the width of the combustion zone and the maximum temperature of the flame front across the sintering bed. For the analysis of the results, a data acquisition system was used. This consisted of two modules connected in serie, for performing the analogue-digital conversion. The analogue entry point is the exit point of the thermocouples and the digital exit point was the temperature average. A computer was used for conserving and storing the data and for carrying out interpolations, simulating the state and evolution of the flame front across the bed.

    En una planta piloto de sinterización se cargan, en la paila cúbica de 40 cm de lado, 110 kg de una mezcla de minerales de hierro, caliza y coque, donde se han introducido una serie de termopares a diferentes profundidades. Se realizan ensayos para estudiar la evolución del ancho de la zona de combustión y de la temperatura máxima del frente de llama a través del lecho de sinterización. Para el análisis de los resultados se utiliza un sistema de adquisición de datos formado por dos módulos conectados en serie, encargados de realizar la conversión analógico-digital. La entrada analógica es la salida de los termopares y la salida digital es la medida de la temperatura. Se dispone de un ordenador para la conservación y almacenamiento de los datos y para realizar interpolaciones que simulan el estado y evolución del frente de llama a través del lecho.

  5. Fragments of Time

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    Time travel films necessarily fragment linear narratives, as scenes are revisited with differences from the first time we saw it. Popular films such as Back to the Future mine comedy from these visitations, but there are many different approaches. One extreme is Chris Marker's La Jetée - a film...... made almost completely of still images, recounting the end of the world. These stills can be viewed as fragments that have survived the end of the world and now provide the only access to the events that occured. Shane Carruth's Primer has a different approach to time travel, the narrative diegesis...... that is presented; how do we understand such films and to what extent is it even possible to make sense of a film that has no real beginning, middle or end?...

  6. Fragmentation of atomic systems

    International Nuclear Information System (INIS)

    Bohn, J.L.; Fano, U.

    1996-01-01

    We report recent progress toward a nonperturbative formulation of many-body quantum dynamics that treats all constituent particles on an equal footing. This formulation is capable of detailing the evolution of a system toward the diverse fragments into which it can break up. We illustrate the general concept with the simple example of the simultaneous excitation of both electrons in a helium atom. copyright 1996 The American Physical Society

  7. Modelling the fragmentation mechanisms

    International Nuclear Information System (INIS)

    Bougault, R.; Durand, D.; Gulminelli, F.

    1998-01-01

    We have investigated the role of high amplitude collective motion in the nuclear fragmentation by using semi-classical macroscopic, as well as, microscopic simulations (BUU). These studies are motivated by the search of instabilities responsible for nuclear fragmentation. Two cases were examined: the bubble formation following the collective expansion of the compressed nucleus in case of very central reactions and, in the case of the semi-central collisions, the fast fission of the two partners issued from a binary reaction, in their corresponding Coulomb field. In the two cases the fragmentation channel is dominated by the inter-relation between the Coulomb and nuclear fields, and it is possible to obtain semi-quantitative predictions as functions of interaction parameters. The transport equations of BUU type predicts for central reactions formation of a high density transient state. Of much interest is the mechanism subsequent to de-excitation. It seems reasonable to conceive that the pressure stocked in the compressional mode manifests itself as a collective expansion of the system. As the pressure is a increasing function of the available energy one can conceive a variety of energy depending exit channels, starting from the fragmentation due the amplification of fluctuations interior to the spinodal zone up to the complete vaporization of the highly excited system. If the reached pressure is sufficiently high the reaction final state may preserve the memory of the entrance channel as a collective radial energy superimposed to the thermal disordered motion. Distributions of particles in the configuration space for both central and semi-central reactions for the Pb+Au system are presented. The rupture time is estimated to the order of 300 fm/c, and is strongly dependent on the initial temperature. The study of dependence of the rupture time on the interaction parameters is under way

  8. Hot nuclei and fragmentation

    International Nuclear Information System (INIS)

    Guerreau, D.

    1993-01-01

    A review is made of the present status concerning the production of nuclei above 5 MeV temperature. Considerable progress has been made recently on the understanding of the formation and the fate of such hot nuclei. It appears that the nucleus seems more stable against temperature than predicted by static calculations. However, the occurrence of multifragment production at high excitation energies is now well established. The various experimental features of the fragmentation process are discussed. (author) 59 refs., 12 figs

  9. Excited nuclei fragmentation

    International Nuclear Information System (INIS)

    Ngo, C.

    1986-11-01

    Experimental indications leading to the thought of a very excited nucleus fragmentation are resumed. Theoretical approaches are briefly described; they are used to explain the phenomenon in showing off they are based on a minimum information principle. This model is based on time dependent Thomas-Fermi calculation which allows the mean field effect description, and with a site-bound percolation model which allows the fluctuation description [fr

  10. Effect of monoclonal antibodies on limited proteolysis of native glycoprotein gD of herpes simplex virus type 1

    International Nuclear Information System (INIS)

    Eisenberg, R.J.; Long, D.; Pereira, L.; Hampar, B.; Zweig, M.; Cohen, G.H.

    1982-01-01

    We examined the properties of 17 monoclonal antibodies to glycoprotein gD of herpes simplex type 1 (HSV-1) (gD-1) and HSV-2 (gD-2). The antibodies recognized eight separate determinants of gD, based on differences in radioimmuno-precipitation and neutralization assays. The determinants were distributed as follows: three were gD-1 specific, one was gD-2 specific, and four were type common. Several type-specific and type-common determinants appeared to be involved in neutralization. We developed a procedure for examining the effect that binding of monoclonal antibody has on proteolysis of native gD-1 by Staphylococcus aureus protease V8. We showed that several different patterns of protease V8 cleavage were obtained, depending on the monoclonal antibody used. The proteolysis patterns were generally consistent with the immunological groupings. With four groups of antibodies, we found that fragments of gD-1 remained bound to antibody after V8 treatment. A 38,000-dalton fragment remained bound to antibodies in three different groups of monoclonal antibodies. This fragment appeared to contain one type-common and two type-specific determinants. A 12,000-dalton fragment remained bound to antibodies belonging to one type-common group of monoclonal antibodies. Tryptic peptide analysis revealed that the 12,000-dalton fragment represented a portion of the 38,000-dalton fragment and was enriched in a type-common arginine tryptic peptide

  11. 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.

  12. Detection of thrombi using a Tc-99m labelled antifibrin monoclonal antibody (MoAb)

    International Nuclear Information System (INIS)

    Wasser, M.N.J.M.

    1989-01-01

    This thesis presents an investigation into the possibility of immunoscintigraphic detection of thrombi using an antifibrin monoclonal antibody, and fragments of the latter. The antifibrin antibody and tis fragments were labelled with Ec-99m, which has excellent characteristics for imaging with a gamma camera. The characterization of the antifibrin antibody and its fragments, the assessment of quality of labelling with Tc-99m, and results of experiments in vitro and in animals, which show the potential of immunoscintigraphic detection, are described. (author). 142 refs.; 44 figs.; 5 tabs

  13. Raising an Antibody Specific to Breast Cancer Subpopulations Using Phage Display on Tissue Sections

    DEFF Research Database (Denmark)

    Larsen, Simon Asbjørn; Meldgaard, Theresa; Fridriksdottir, Agla Jael Rubner

    2016-01-01

    BACKGROUND/AIM: Primary tumors display a great level of intra-tumor heterogeneity in breast cancer. The current lack of prognostic and predictive biomarkers limits accurate stratification and the ability to predict response to therapy. The aim of the present study was to select recombinant antibody...... fragments specific against breast cancer subpopulations, aiding the discovery of novel biomarkers. MATERIALS AND METHODS: Recombinant antibody fragments were selected by phage display. A novel shadowstick technology enabled the direct selection using tissue sections of antibody fragments specific against...

  14. Azimuthal Anisotropies in Nuclear Fragmentation

    International Nuclear Information System (INIS)

    Dabrowska, A.; Szarska, M.; Trzupek, A.; Wolter, W.; Wosiek, B.

    2002-01-01

    The directed and elliptic flow of fragments emitted from the excited projectile nuclei has been observed for 158 AGeV Pb collisions with the lead and plastic targets. For comparison the flow analysis has been performed for 10.6 AGeV Au collisions with the emulsion target. The strong directed flow of heaviest fragments is found. Light fragments exhibit directed flow opposite to that of heavy fragments. The elliptic flow for all multiply charged fragments is positive and increases with the charge of the fragment. The observed flow patterns in the fragmentation of the projectile nucleus are practically independent of the mass of the target nucleus and the collision energy. Emission of fragments in nuclear multifragmentation shows similar, although weaker, flow effects. (author)

  15. Universality of projectile fragmentation model

    International Nuclear Information System (INIS)

    Chaudhuri, G.; Mallik, S.; Das Gupta, S.

    2012-01-01

    Presently projectile fragmentation reaction is an important area of research as it is used for the production of radioactive ion beams. In this work, the recently developed projectile fragmentation model with an universal temperature profile is used for studying the charge distributions of different projectile fragmentation reactions with different projectile target combinations at different incident energies. The model for projectile fragmentation consists of three stages: (i) abrasion, (ii) multifragmentation and (iii) evaporation

  16. Virtual fragment preparation for computational fragment-based drug design.

    Science.gov (United States)

    Ludington, Jennifer L

    2015-01-01

    Fragment-based drug design (FBDD) has become an important component of the drug discovery process. The use of fragments can accelerate both the search for a hit molecule and the development of that hit into a lead molecule for clinical testing. In addition to experimental methodologies for FBDD such as NMR and X-ray Crystallography screens, computational techniques are playing an increasingly important role. The success of the computational simulations is due in large part to how the database of virtual fragments is prepared. In order to prepare the fragments appropriately it is necessary to understand how FBDD differs from other approaches and the issues inherent in building up molecules from smaller fragment pieces. The ultimate goal of these calculations is to link two or more simulated fragments into a molecule that has an experimental binding affinity consistent with the additive predicted binding affinities of the virtual fragments. Computationally predicting binding affinities is a complex process, with many opportunities for introducing error. Therefore, care should be taken with the fragment preparation procedure to avoid introducing additional inaccuracies.This chapter is focused on the preparation process used to create a virtual fragment database. Several key issues of fragment preparation which affect the accuracy of binding affinity predictions are discussed. The first issue is the selection of the two-dimensional atomic structure of the virtual fragment. Although the particular usage of the fragment can affect this choice (i.e., whether the fragment will be used for calibration, binding site characterization, hit identification, or lead optimization), general factors such as synthetic accessibility, size, and flexibility are major considerations in selecting the 2D structure. Other aspects of preparing the virtual fragments for simulation are the generation of three-dimensional conformations and the assignment of the associated atomic point charges.

  17. Imaging of colorectal carcinoma with radiolabeled antibodies.

    Science.gov (United States)

    Goldenberg, D M; Goldenberg, H; Sharkey, R M; Lee, R E; Higgenbotham-Ford, E; Horowitz, J A; Hall, T C; Pinsky, C M; Hansen, H J

    1989-10-01

    Colorectal cancer has been the tumor type most frequently studied with radiolabeled antibodies. Among the various antibodies, a majority of patients with colorectal cancer have received xenogeneic polyclonal or monoclonal antibodies against carcino-embryonic antigen. This review summarizes the current status of colorectal cancer imaging with radiolabeled antibodies, ie, radioimmunodetection (RAID), and examines the published studies involving carcinoembryonic antigen (CEA) antibodies and 17-1A, 19-9, and B72.3, and other monoclonal antibodies. In order to better address the issue of the current and future clinical usefulness of this emerging technology, particular attention is given to the protocols, methods, and results of the published studies. Despite differences in study parameters, antibodies and forms, labels, administration routes and doses, and scanning instruments and methods, it has been found that (1) almost no adverse reactions have been evident; (2) antibody fragments are preferred over whole immunoglobulin G reagents because they achieve higher tumor-to-background ratios earlier, thus reducing or precluding the need for dual-isotope subtraction methods or long delays before imaging; (3) use of antibody fragments, including the monovalent Fab' form, permits imaging with short-lived radionuclides of excellent photon properties, such as 123I and 99mTc; (4) circulating antigens against which the imaging antibody is directed can complex with the injected antibody, but such complexes have not prevented successful RAID; (5) patients with high serum titers of the appropriate antigen target usually have higher rates of positive RAID; (6) patients who are seronegative for the tumor antigen being studied can have positive RAID findings, which can represent the detection of occult lesions; (7) single photon emission computed tomography appears to provide better image resolution than planar scanning; (8) regardless of the sensitivity reported in any particular

  18. An Archeology of Fragments

    Directory of Open Access Journals (Sweden)

    Gerald L. Bruns

    2014-10-01

    Full Text Available This is a short (fragmentary history of fragmentary writing from the German Romantics (F. W. Schlegel, Friedrich Hölderlin to modern and contemporary concrete or visual poetry. Such writing is (often deliberately a critique of the logic of subsumption that tries to assimilate whatever is singular and irreducible into totalities of various categorical or systematic sorts. Arguably, the fragment (parataxis is the distinctive feature of literary Modernism, which is a rejection, not of what precedes it, but of what Max Weber called “the rationalization of the world” (or Modernity whose aim is to keep everything, including all that is written, under surveillance and control.

  19. C4d-negative antibody-mediated rejection with high anti-angiotensin II type I receptor antibodies in absence of donor-specific antibodies.

    Science.gov (United States)

    Fuss, Alexander; Hope, Christopher M; Deayton, Susan; Bennett, Greg Donald; Holdsworth, Rhonda; Carroll, Robert P; Coates, P Toby H

    2015-07-01

    Acute antibody-mediated rejection can occur in absence of circulating donor-specific antibodies. Agonistic antibodies targeting the anti-angiotensin II type 1 receptor (anti-AT1 R) are emerging as important non-human leucocyte antigen (HLA) antibodies. Elevated levels of anti-angiotensin II receptor antibodies were first observed in kidney transplant recipients with malignant hypertension and allograft rejection. They have now been studied in three separate kidney transplant populations and associate to frequency of rejection, severity of rejection and graft failure. We report 11 cases of biopsy-proven, Complement 4 fragment d (C4d)-negative, acute rejection occurring without circulating donor-specific anti-HLA antibodies. In eight cases, anti-angiotensin receptor antibodies were retrospectively examined. The remaining three subjects were identified from our centre's newly instituted routine anti-angiotensin receptor antibody screening. All subjects fulfilled Banff 2013 criteria for antibody-mediated rejection and all responded to anti-rejection therapy, which included plasma exchange and angiotensin receptor blocker therapy. These cases support the routine assessment of anti-AT1 R antibodies in kidney transplant recipients to identify subjects at risk. Further studies will need to determine optimal assessment protocol and the effectiveness of pre-emptive treatment with angiotensin receptor blockers. © 2015 Asian Pacific Society of Nephrology.

  20. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Legrain, R.

    1984-08-01

    Projectile and nuclear fragmentation are defined and processes referred to are recalled. The two different aspects of fragmentation are considered but the emphasis is also put on heavy ion induced reactions. The preliminary results of an experiment performed at GANIL to study peripheral heavy ions induced reactions at intermediate energy are presented. The results of this experiment will illustrate the characteristics of projectile fragmentation and this will also give the opportunity to study projectile fragmentation in the transition region. Then nuclear fragmentation is considered which is associated with more central collisions in the case of heavy ion induced reactions. This aspect of fragmentation is also ilustrated with two heavy ion experiments in which fragments emitted at large angle have been observed

  1. Fragmentation of random trees

    International Nuclear Information System (INIS)

    Kalay, Z; Ben-Naim, E

    2015-01-01

    We study fragmentation of a random recursive tree into a forest by repeated removal of nodes. The initial tree consists of N nodes and it is generated by sequential addition of nodes with each new node attaching to a randomly-selected existing node. As nodes are removed from the tree, one at a time, the tree dissolves into an ensemble of separate trees, namely, a forest. We study statistical properties of trees and nodes in this heterogeneous forest, and find that the fraction of remaining nodes m characterizes the system in the limit N→∞. We obtain analytically the size density ϕ s of trees of size s. The size density has power-law tail ϕ s ∼s −α with exponent α=1+(1/m). Therefore, the tail becomes steeper as further nodes are removed, and the fragmentation process is unusual in that exponent α increases continuously with time. We also extend our analysis to the case where nodes are added as well as removed, and obtain the asymptotic size density for growing trees. (paper)

  2. Immunogenicity of anti-tumor necrosis factor antibodies-toward improved methods of anti-antibody measurement.

    Science.gov (United States)

    Aarden, Lucien; Ruuls, Sigrid R; Wolbink, Gertjan

    2008-08-01

    To date, millions of people have been treated with therapeutic monoclonal antibodies (TmAbs) for various indications. It is becoming increasingly clear that TmAbs can be immunogenic, which may reduce efficacy or induce adverse effects. Over the years, the importance of antibody formation has been questioned and sometimes minimized, as few antibody responses to TmAbs (HACA or HAHA) were reported. However, the methods to detect and quantify such antibodies used in the past have been problematic. Only recently, methods have been developed that have adequate sensitivity and are not seriously disturbed by false-positive reactions caused by rheumatoid factors, natural antibodies to Fab or F(ab')2 fragments, or Fc interactions of IgG4. The large number of treated patients, in combination with these new assays, presents a unique opportunity to study the anti-antibody immune response in man, possibly allowing us to manipulate immunogenicity in the future.

  3. Inhibition of type VI secretion by an anti-TssM llama nanobody.

    Directory of Open Access Journals (Sweden)

    Van Son Nguyen

    Full Text Available The type VI secretion system (T6SS is a secretion pathway widespread in Gram-negative bacteria that targets toxins in both prokaryotic and eukaryotic cells. Although most T6SSs identified so far are involved in inter-bacterial competition, a few are directly required for full virulence of pathogens. The T6SS comprises 13 core proteins that assemble a large complex structurally and functionally similar to a phage contractile tail structure anchored to the cell envelope by a trans-membrane spanning stator. The central part of this stator, TssM, is a 1129-amino-acid protein anchored in the inner membrane that binds to the TssJ outer membrane lipoprotein. In this study, we have raised camelid antibodies against the purified TssM periplasmic domain. We report the crystal structure of two specific nanobodies that bind to TssM in the nanomolar range. Interestingly, the most potent nanobody, nb25, competes with the TssJ lipoprotein for TssM binding in vitro suggesting that TssJ and the nb25 CDR3 loop share the same TssM binding site or causes a steric hindrance preventing TssM-TssJ complex formation. Indeed, periplasmic production of the nanobodies displacing the TssM-TssJ interaction inhibits the T6SS function in vivo. This study illustrates the power of nanobodies to specifically target and inhibit bacterial secretion systems.

  4. 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.

  5. Antibodies and Selection of Monoclonal Antibodies.

    Science.gov (United States)

    Hanack, Katja; Messerschmidt, Katrin; Listek, Martin

    Monoclonal antibodies are universal binding molecules with a high specificity for their target and are indispensable tools in research, diagnostics and therapy. The biotechnological generation of monoclonal antibodies was enabled by the hybridoma technology published in 1975 by Köhler and Milstein. Today monoclonal antibodies are used in a variety of applications as flow cytometry, magnetic cell sorting, immunoassays or therapeutic approaches. First step of the generation process is the immunization of the organism with appropriate antigen. After a positive immune response the spleen cells are isolated and fused with myeloma cells in order to generate stable, long-living antibody-producing cell lines - hybridoma cells. In the subsequent identification step the culture supernatants of all hybridoma cells are screened weekly for the production of the antibody of interest. Hybridoma cells producing the antibody of interest are cloned by limited dilution till a monoclonal hybridoma is found. This is a very time-consuming and laborious process and therefore different selection strategies were developed since 1975 in order to facilitate the generation of monoclonal antibodies. Apart from common automation of pipetting processes and ELISA testing there are some promising approaches to select the right monoclonal antibody very early in the process to reduce time and effort of the generation. In this chapter different selection strategies for antibody-producing hybridoma cells are presented and analysed regarding to their benefits compared to conventional limited dilution technology.

  6. Fragment-based lead generation: identification of seed fragments by a highly efficient fragment screening technology

    Science.gov (United States)

    Neumann, Lars; Ritscher, Allegra; Müller, Gerhard; Hafenbradl, Doris

    2009-08-01

    For the detection of the precise and unambiguous binding of fragments to a specific binding site on the target protein, we have developed a novel reporter displacement binding assay technology. The application of this technology for the fragment screening as well as the fragment evolution process with a specific modelling based design strategy is demonstrated for inhibitors of the protein kinase p38alpha. In a fragment screening approach seed fragments were identified which were then used to build compounds from the deep-pocket towards the hinge binding area of the protein kinase p38alpha based on a modelling approach. BIRB796 was used as a blueprint for the alignment of the fragments. The fragment evolution of these deep-pocket binding fragments towards the fully optimized inhibitor BIRB796 included the modulation of the residence time as well as the affinity. The goal of our study was to evaluate the robustness and efficiency of our novel fragment screening technology at high fragment concentrations, compare the screening data with biochemical activity data and to demonstrate the evolution of the hit fragments with fast kinetics, into slow kinetic inhibitors in an in silico approach.

  7. 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...

  8. Sortilin Fragments Deposit at Senile Plaques in Human Cerebrum

    Directory of Open Access Journals (Sweden)

    Xia Hu

    2017-06-01

    Full Text Available Genetic variations in the vacuolar protein sorting 10 protein (Vps10p family have been linked to Alzheimer’s disease (AD. Here we demonstrate deposition of fragments from the Vps10p member sortilin at senile plaques (SPs in aged and AD human cerebrum. Sortilin changes were characterized in postmortem brains with antibodies against the extracellular and intracellular C-terminal domains. The two antibodies exhibited identical labeling in normal human cerebrum, occurring in the somata and dendrites of cortical and hippocampal neurons. The C-terminal antibody also marked extracellular lesions in some aged and all AD cases, appearing as isolated fibrils, mini-plaques, dense-packing or circular mature-looking plaques. Sortilin and β-amyloid (Aβ deposition were correlated overtly in a region/lamina- and case-dependent manner as analyzed in the temporal lobe structures, with co-localized immunofluorescence seen at individual SPs. However, sortilin deposition rarely occurred around the pia, at vascular wall or in areas with typical diffuse Aβ deposition, with the labeling not enhanced by section pretreatment with heating or formic acid. Levels of a major sortilin fragment ~15 kDa, predicted to derive from the C-terminal region, were dramatically elevated in AD relative to control cortical lysates. Thus, sortilin fragments are a prominent constituent of the extracellularly deposited protein products at SPs in human cerebrum.

  9. The future of antibody therapeutics: ADCs bi-specifics and RIT

    International Nuclear Information System (INIS)

    Reichert, J.

    2015-01-01

    Full text of publication follows. Antibodies are widely accepted as remarkably versatile therapeutic agents. As evidence of this, the ∼ 30 antibody products marketed worldwide had total global sales of more than 50 billion dollars in 2012, and the commercial clinical pipeline currently comprises over 350 antibody-based product candidates. In a testament to scientific ingenuity, the investigational molecules (clinical and preclinical) are notably diverse in their composition of matter and include antibodies conjugated to a variety of agents (drugs, radioisotopes), bi-specific antibodies, and fragments or domains of antibodies. The concepts that form the basis of these agents were established decades ago, but advances in technology are now allowing new opportunities for their development. In this presentation, future directions in antibody therapeutics development will be discussed, with a focus on antibody-drug conjugates, bi-specific antibodies and radioimmunotherapy. (author)

  10. Cobre en alimentos de consumo básico por espectroscopia de absorción atómica modalidad de llama, Costa Rica

    OpenAIRE

    Paulina Silva Trejos

    2012-01-01

    Objetivo: Cuantificar el contenido de cobre en alimentos de la canasta básica de consumo del costarricense. Materiales y métodos: Los alimentos se procesaron de acuerdo con el patrón de consumo costarricense, se determinó la cantidad óptima de HNO3.al 65 % óptimo para su digestión en horno de microondas por evaluación de los porcentajes de recuperación. La cuantificación se realizó sobre las muestras digeridas por espectroscopia de absorción atómica de llama., las mediciones se hicieron a 324...

  11. Fragmented medial coronoid process

    International Nuclear Information System (INIS)

    Juhasz, Cs.; Juhasz, T.

    1997-01-01

    Fragmented medial coronoid process: (FCP) is often considered to be part of the osteochondrosis dissecans complex, but trauma and growth discrepancies between the radius and ulna are proposed as causes. There is little to clinically differentiate FCP, from osteochondrosis dissecans (OCD) of the elbow. Pain on, flexion-extension of the elbow and lateral rotation of the paw is a little more consistent in FCP. Radiographic examination of the elbow is important despite the, fact that radiographic signs of the FCP are often nonspecific. Excessive osteoarthrosis and superimposition of the radial head and coronoid process make identification of the FCP difficult. Craniocaudal, flexed mediolateral and 25 degree craniocaudal-lateromedial views are necessary for diagnosis. Osteophyte production is more dramatic with FCP than with OCD and suggests therefore the occurrence of OCP in many cases. Although the detached process may be seen on any view, the oblique projection offers the least obstructed view. Exposure of the joint is identical to that for OCD, that means a medial approach with osteotomy of the epicondyle. In most cases the process is loose enough to be readily apparent, but in some it is necessary to exert force on the process in order to find the cleavage plane. It is necessary to remove the osteophytes as well and to inspect and irrigate the joint carefully to remove cartilage fragments before closure. Confinement is advisable for 4 weeks before returning the dog to normal activity. The outlook for function is good if the FCP is removed before secondary degenerative joint disease is well established

  12. INCREASING OF THE EXPRESSION OF RECOMBINANT scFv-ANTIBODIES EFFICIENCY

    Directory of Open Access Journals (Sweden)

    O.V. Galkin

    2017-10-01

    Full Text Available Obtaining single-chain variable fragments (scFv of recombinant antibodies in E. coli cells is often associated with numerous problems causing low yields or inactive conformation of the product. The aim of this work was to study the influence of staphylococcal protein A fragment fused with scFv antibodies (SpA-tag on the efficiency of expression of final product. Examination of scFv antibodies of different origin and specificity has shown that in similar expression systems fused scFv is synthesized in much higher quantities than free scFv. Furthermore, the scFv antibodies in fused form retained their antigen-binding properties and the SpA fragment the ability to bind other immunoglobulins. Thus, the proposed strategy can be considered effective in improving the efficiency of scFv-antibodies production in E. coli cells.

  13. Fractal statistics of brittle fragmentation

    Directory of Open Access Journals (Sweden)

    M. Davydova

    2013-04-01

    Full Text Available The study of fragmentation statistics of brittle materials that includes four types of experiments is presented. Data processing of the fragmentation of glass plates under quasi-static loading and the fragmentation of quartz cylindrical rods under dynamic loading shows that the size distribution of fragments (spatial quantity is fractal and can be described by a power law. The original experimental technique allows us to measure, apart from the spatial quantity, the temporal quantity - the size of time interval between the impulses of the light reflected from the newly created surfaces. The analysis of distributions of spatial (fragment size and temporal (time interval quantities provides evidence of obeying scaling laws, which suggests the possibility of self-organized criticality in fragmentation.

  14. Identification of antibody glycosylation structures that predict monoclonal antibody Fc-effector function.

    Science.gov (United States)

    Chung, Amy W; Crispin, Max; Pritchard, Laura; Robinson, Hannah; Gorny, Miroslaw K; Yu, Xiaojie; Bailey-Kellogg, Chris; Ackerman, Margaret E; Scanlan, Chris; Zolla-Pazner, Susan; Alter, Galit

    2014-11-13

    To determine monoclonal antibody (mAb) features that predict fragment crystalizable (Fc)-mediated effector functions against HIV. Monoclonal antibodies, derived from Chinese hamster ovary cells or Epstein-Barr virus-immortalized mouse heteromyelomas, with specificity to key regions of the HIV envelope including gp120-V2, gp120-V3 loop, gp120-CD4(+) binding site, and gp41-specific antibodies, were functionally profiled to determine the relative contribution of the variable and constant domain features of the antibodies in driving robust Fc-effector functions. Each mAb was assayed for antibody-binding affinity to gp140(SR162), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and for the ability to bind to FcγRIIa, FcγRIIb and FcγRIIIa receptors. Antibody glycan profiles were determined by HPLC. Neither the specificity nor the affinity of the mAbs determined the potency of Fc-effector function. FcγRIIIa binding strongly predicted ADCC and decreased galactose content inversely correlated with ADCP, whereas N-glycolylneuraminic acid-containing structures exhibited enhanced ADCP. Additionally, the bi-antenary glycan arm onto which galactose was added predicted enhanced binding to FcγRIIIa and ADCC activity, independent of the specificity of the mAb. Our studies point to the specific Fc-glycan structures that can selectively promote Fc-effector functions independently of the antibody specificity. Furthermore, we demonstrated antibody glycan structures associated with enhanced ADCP activity, an emerging Fc-effector function that may aid in the control and clearance of HIV infection.

  15. Fluctuations in the fragmentation process

    International Nuclear Information System (INIS)

    Botet, R.; Ploszajczak, M.

    1993-01-01

    Some general framework of sequential fragmentation is presented, as provided by the newly proposed Fragmentation - Inactivation - Binary model, and to study briefly its basic and universal features. This model includes as particular cases most of the previous kinetic fragmentation models. In particular it is discussed how one arrives in this framework to the critical behaviour, called the shattering transition. This model is then compared to recent data on gold multifragmentation at 600 MeV/nucl. (authors) 20 refs., 5 figs

  16. Making Recombinant Monoclonal Antibody And Radiolabelling For Medical Purpose

    International Nuclear Information System (INIS)

    Nguyen Thi Thu; Duong Van Dong; Vo Thi Cam Hoa; Bui Van Cuong; Chu Van Khoa; Vu Bich Huong; Le Quang Huan

    2008-01-01

    Recombinant monoclonal antibody labeling with 131 I specific to tumor cell has been studied and prepared for treatment of Hodgkin lymphoma. In this study, a recombinant monoclonal antibody with two specific properties is a hybrid molecule created by coupling an antibody variable fragments with peptide melittin. The gene coding the antibody fragment has been obtained from human synthetic Fv libraries using for panning and screening on populations of lymphocytes fragmented from human blood cells with Hodgkin diseases. The gene encoding peptit melittin has been cloned from honeybee Apis cerana DNA. The gene coding recombinant monoclonal antibody has been expressed in E.coli BL21 (DE3) at 37 o C and was induced with 0.6 mM IPTG. The recombinant compound has been purified by affinity chromatography with HiTrap affinity column. The obtained recombinant monoclonal antibody has showed cytolytic activities when added to cell culture medium for LU cancer cell line with the amount of 100 - 200 mg/ml. This monoclonal antibody is labeled with 131 I using chloramine T procedure. ChT mass for the oxidation of 50 μg monoclonal antibody in 76 MBq was 10 μg. Sodium metabisulfite was used as a reducing agent. Reaction time was above 3 mins. The radiochemical purity was determined using electrophoresis and TLC methods. Radiochemical yield was > 97%. Radiochemical purity after purification was > 99%. Nuclear purity was > 99%. Stability of the label antibody was 12 days. This is the product promise potential used in the diagnostic and therapeutic of Hodgkin lymphoma. (author)

  17. MRI of displaced meniscal fragments

    International Nuclear Information System (INIS)

    Dunoski, Brian; Zbojniewicz, Andrew M.; Laor, Tal

    2012-01-01

    A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

  18. MRI of displaced meniscal fragments

    Energy Technology Data Exchange (ETDEWEB)

    Dunoski, Brian [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Zbojniewicz, Andrew M.; Laor, Tal [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States)

    2012-01-15

    A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

  19. Lyme disease antibody

    Science.gov (United States)

    ... JavaScript. The Lyme disease blood test looks for antibodies in the blood to the bacteria that causes ... needed. A laboratory specialist looks for Lyme disease antibodies in the blood sample using the ELISA test . ...

  20. Antinuclear antibody panel

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003535.htm Antinuclear antibody panel To use the sharing features on this page, please enable JavaScript. The antinuclear antibody panel is a blood test that looks at ...