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Sample records for antibody cha21 inhibits

  1. 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)

    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 P212121

  2. [Inhibition of adenovirus reproduction in cell culture by specific antibodies].

    Science.gov (United States)

    Povnytsia, O Iu; Nosach, L M; Zhovnovata, V L; Zahorodnia, S D; Vantsak, N P; Tokarchuk, L V; Polishchuk, O M; Diachenko, N S

    2009-01-01

    The capacity of specific antibodies to inhibit the reproduction of homo- and heterologous adenoviruses in Hela cell added to culture medium after virus adsorption was studied. The inhibiting effect of polyclonal antivirus and monospecific antihexone antibodies to homo- and heterologous adenoviruses was shown. The effect was more expressed when using antibodies to homologous antibodies. The intensity of inhibition depended on antibodies concentration in the medium and infecting dose of the virus. Essential reduction of the quantity of infected cells and a decrease of the titer of adenovirus synthesized in the presence of homo- and heterologous antibodies was shown but adenovirus reproduction was not inhibited completely. PMID:19663330

  3. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

    Directory of Open Access Journals (Sweden)

    Milly M Choy

    2015-11-01

    Full Text Available The mosquito-borne dengue virus (DENV is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue.

  4. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

    Science.gov (United States)

    Choy, Milly M; Zhang, Summer L; Costa, Vivian V; Tan, Hwee Cheng; Horrevorts, Sophie; Ooi, Eng Eong

    2015-11-01

    The mosquito-borne dengue virus (DENV) is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP) to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue. PMID:26565697

  5. Monoclonal antibodies to the apical chloride channel in Necturus gallbladder inhibit the chloride conductance.

    OpenAIRE

    Finn, A L; Tsai, L M; Falk, R J

    1989-01-01

    Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The...

  6. Ligation of Fc gamma receptor IIB inhibits antibody-dependent enhancement of dengue virus infection.

    Science.gov (United States)

    Chan, Kuan Rong; Zhang, Summer Li-Xin; Tan, Hwee Cheng; Chan, Ying Kai; Chow, Angelia; Lim, Angeline Pei Chiew; Vasudevan, Subhash G; Hanson, Brendon J; Ooi, Eng Eong

    2011-07-26

    The interaction of antibodies, dengue virus (DENV), and monocytes can result in either immunity or enhanced virus infection. These opposing outcomes of dengue antibodies have hampered dengue vaccine development. Recent studies have shown that antibodies neutralize DENV by either preventing virus attachment to cellular receptors or inhibiting viral fusion intracellularly. However, whether the antibody blocks attachment or fusion, the resulting immune complexes are expected to be phagocytosed by Fc gamma receptor (FcγR)-bearing cells and cleared from circulation. This suggests that only antibodies that are able to block fusion intracellularly would be able to neutralize DENV upon FcγR-mediated uptake by monocytes whereas other antibodies would have resulted in enhancement of DENV replication. Using convalescent sera from dengue patients, we observed that neutralization of the homologous serotypes occurred despite FcγR-mediated uptake. However, FcγR-mediated uptake appeared to be inhibited when neutralized heterologous DENV serotypes were used instead. We demonstrate that this inhibition occurred through the formation of viral aggregates by antibodies in a concentration-dependent manner. Aggregation of viruses enabled antibodies to cross-link the inhibitory FcγRIIB, which is expressed at low levels but which inhibits FcγR-mediated phagocytosis and hence prevents antibody-dependent enhancement of DENV infection in monocytes. PMID:21746897

  7. Targeted in vivo inhibition of specific protein-protein interactions using recombinant antibodies.

    Directory of Open Access Journals (Sweden)

    Matej Zábrady

    Full Text Available With the growing availability of genomic sequence information, there is an increasing need for gene function analysis. Antibody-mediated "silencing" represents an intriguing alternative for the precise inhibition of a particular function of biomolecules. Here, we describe a method for selecting recombinant antibodies with a specific purpose in mind, which is to inhibit intrinsic protein-protein interactions in the cytosol of plant cells. Experimental procedures were designed for conveniently evaluating desired properties of recombinant antibodies in consecutive steps. Our selection method was successfully used to develop a recombinant antibody inhibiting the interaction of ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 3 with such of its upstream interaction partners as the receiver domain of CYTOKININ INDEPENDENT HISTIDINE KINASE 1. The specific down-regulation of the cytokinin signaling pathway in vivo demonstrates the validity of our approach. This selection method can serve as a prototype for developing unique recombinant antibodies able to interfere with virtually any biomolecule in the living cell.

  8. Gamma Interferon Inhibits Production of Anti-OspA Borreliacidal Antibody In Vitro

    OpenAIRE

    Munson, Erik L.; Du Chateau, Brian K.; Jensen, Jani R.; Callister, Steven M.; DeCoster, David J.; Schell, Ronald F.

    2002-01-01

    The ability of a Lyme borreliosis vaccine to induce and maintain sustained levels of borreliacidal antibody is necessary for prolonged protection against infection with Borrelia burgdorferi. Vaccination against infection with B. burgdorferi could be improved by determining the mechanism(s) that influences the production of protective borreliacidal antibody. Borreliacidal antibody was inhibited in cultures of lymph node cells obtained from C3H/HeJ mice vaccinated with formalin-inactivated B. b...

  9. Antibody to a molecular marker of cell position inhibits synapse formation in retina.

    OpenAIRE

    Trisler, D.; Bekenstein, J; Daniels, M P

    1986-01-01

    A topographic gradient of TOP molecules in retina can be used to identify neuron position. Antibody to TOP from hybridoma cells that were injected into in vivo embryo eyes diffused into the retina and bound in a topographic gradient of [antibody.TOP] ([Ab.TOP]) complexes. Synapse formation in retina was inhibited in the presence of anti-TOP antibody. This suggests that TOP is involved in synapse formation and that recognition of position by neurons is necessary for normal synapse formation.

  10. Fully human antagonistic antibodies against CCR4 potently inhibit cell signaling and chemotaxis.

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    Urs B Hagemann

    Full Text Available CC chemokine receptor 4 (CCR4 represents a potentially important target for cancer immunotherapy due to its expression on tumor infiltrating immune cells including regulatory T cells (Tregs and on tumor cells in several cancer types and its role in metastasis.Using phage display, human antibody library, affinity maturation and a cell-based antibody selection strategy, the antibody variants against human CCR4 were generated. These antibodies effectively competed with ligand binding, were able to block ligand-induced signaling and cell migration, and demonstrated efficient killing of CCR4-positive tumor cells via ADCC and phagocytosis. In a mouse model of human T-cell lymphoma, significant survival benefit was demonstrated for animals treated with the newly selected anti-CCR4 antibodies.For the first time, successful generation of anti- G-protein coupled chemokine receptor (GPCR antibodies using human non-immune library and phage display on GPCR-expressing cells was demonstrated. The generated anti-CCR4 antibodies possess a dual mode of action (inhibition of ligand-induced signaling and antibody-directed tumor cell killing. The data demonstrate that the anti-tumor activity in vivo is mediated, at least in part, through Fc-receptor dependent effector mechanisms, such as ADCC and phagocytosis. Anti-CC chemokine receptor 4 antibodies inhibiting receptor signaling have potential as immunomodulatory antibodies for cancer.

  11. Monoclonal Antibodies to the Apical Chloride Channel in Necturus Gallbladder Inhibit the Chloride Conductance

    Science.gov (United States)

    Finn, Arthur L.; Tsai, Lih-Min; Falk, Ronald J.

    1989-10-01

    Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The channel or a closely related molecule is present in the membrane whether or not the pathway is open, since, in addition to inhibiting the conductance of the open channel, the antibody also bound to the membrane in the resting state and prevented subsequent opening of the channel. The antibody was shown to recognize, by ELISA, epitopes from the Necturus gallbladder and small intestine. Finally, by Western blot analysis of Necturus gallbladder homogenates, the antibody was shown to recognize two protein bands of Mr 219,000 and Mr 69,000. This antibody should permit isolation and characterization of this important ion channel.

  12. Insulin action is blocked by a monoclonal antibody that inhibits insulin receptor kinase

    International Nuclear Information System (INIS)

    Thirty-six monoclonal antibodies to the human insulin receptor were produced. Thirty-four bound the intracellular domain of the receptor β subunit, the domain containing the tyrosine-specific kinase activity. Of these 34 antibodies, 33 recognized the rat receptor and 1 was shown to precipitate the receptors from mice, chickens and frogs with high affinity. Another of the antibodies inhibited the kinase activities of the human and frog receptors with equal potencies. This antibody inhibited the kinase activities of these receptors by more than 90%, whereas others had no effect on either kinase activity. Microinjection of the inhibiting antibody into Xenopus oocytes blocked the ability of insulin to stimulate oocyte maturation. In contrast, this inhibiting antibody did not block the ability of progesterone to stimulate the same response. Furthermore, control immunoglobulin and a noninhibiting antibody to the receptor β subunit did not block this response to insulin. These results strongly support a role for the tyrosine-specific kinase activity of the insulin receptor in mediating this biological effect of insulin

  13. Separation of hemagglutination-inhibiting immunoglobulin M antibody to rubella virus in human serum by high-performance liquid chromatography.

    OpenAIRE

    N. Kobayashi; M. Suzuki; Nakagawa, T.; Matumoto, M

    1986-01-01

    High-performance liquid chromatography was successfully used to separate hemagglutination-inhibiting immunoglobulin M (IgM) rubella virus antibody from IgG rubella virus antibody in human serum. The fractionation by high-performance liquid chromatography was as effective as sucrose density gradient centrifugation in separating IgM antibody from IgG antibody.

  14. Antipeptide antibody that specifically inhibits insulin receptor autophosphorylation and protein kinase activity

    International Nuclear Information System (INIS)

    Two site-specific antibodies that immunoprecipitate the human insulin receptor have been prepared by immunizing rabbits with chemically synthesized peptides derived from the cDNA-predicted amino acid sequence of the β subunit of the proreceptor. Antibodies to the carboxyl terminus (AbP5) and to a domain around tyrosine-960 (AbP4) specifically recognize the β subunit of the receptor on immunoblots. Both antibodies immunoprecipitated 125I-labeled insulin-receptor complexes and the autophosphorylated receptor. Although neither antibody inhibited insulin binding to the receptor, both insulin-dependent autophosphorylation and exogenous substrate phosphorylation were inhibited by AbP4. Inhibition by AbP4 was dependent upon the phosphorylation state of the receptor; it was not detected when the receptor was autophosphorylated prior to addition of AbP4. AbP4 did not inhibit activity of the related epidermal growth factor (EGF)-receptor tyrosine protein kinase nor did it inhibit the activity of cAMP-dependent kinase or protein kinase C. The observation that an antibody directed to residues 952-967 of the proreceptor neutralizes the protein kinase activity of the β subunit suggest that this region may play a critical role in the function of the hormone-dependent, protein tyrosine-specific kinase activity of the insulin receptor

  15. Overcoming the Constraints of Anti-HIV/CD89 Bispecific Antibodies That Limit Viral Inhibition

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    Xiaocong Yu

    2016-01-01

    Full Text Available Innovative strategies are necessary to maximize the clinical application of HIV neutralizing antibodies. To this end, bispecific constructs of human antibody F240, reactive with well-conserved gp41 epitope and antibody 14A8, reactive with the IgA receptor (CD89 on effector cells, were constructed. A F240 × 14A8 bispecific single chain variable region (scFv molecule was constructed by linking two scFvs using a conventional GGGGS linker. Despite immunoreactivity with HIV gp41 and neutrophils, this bispecific scFv failed to inhibit HIV infection. This is in sharp contrast to viral inhibition using a chemical conjugate of the Fab of these two antibodies. Therefore, we constructed two novel Fab-like bispecific antibody molecules centered on fusion of the IgG1 CH1 domain or CH1-hinge domain to the C-terminus of F240scFv and fusion of the kappa chain CL domain to the C-terminus of 14A8scFv. Both Bi-Fab antibodies showed significant ADCVI activity for multiple clade B and clade C isolates by arming the neutrophils to inhibit HIV infection. The approach presented in this study is unique for HIV immunotherapy in that the impetus of neutralization is to arm and mobilize PMN to destroy HIV and HIV infected cells.

  16. Overcoming the Constraints of Anti-HIV/CD89 Bispecific Antibodies That Limit Viral Inhibition.

    Science.gov (United States)

    Yu, Xiaocong; Duval, Mark; Gawron, Melissa; Posner, Marshall R; Cavacini, Lisa A

    2016-01-01

    Innovative strategies are necessary to maximize the clinical application of HIV neutralizing antibodies. To this end, bispecific constructs of human antibody F240, reactive with well-conserved gp41 epitope and antibody 14A8, reactive with the IgA receptor (CD89) on effector cells, were constructed. A F240 × 14A8 bispecific single chain variable region (scFv) molecule was constructed by linking two scFvs using a conventional GGGGS linker. Despite immunoreactivity with HIV gp41 and neutrophils, this bispecific scFv failed to inhibit HIV infection. This is in sharp contrast to viral inhibition using a chemical conjugate of the Fab of these two antibodies. Therefore, we constructed two novel Fab-like bispecific antibody molecules centered on fusion of the IgG1 CH1 domain or CH1-hinge domain to the C-terminus of F240scFv and fusion of the kappa chain CL domain to the C-terminus of 14A8scFv. Both Bi-Fab antibodies showed significant ADCVI activity for multiple clade B and clade C isolates by arming the neutrophils to inhibit HIV infection. The approach presented in this study is unique for HIV immunotherapy in that the impetus of neutralization is to arm and mobilize PMN to destroy HIV and HIV infected cells. PMID:27419146

  17. Streptococcus pneumoniae-Induced Inhibition of Rat Ependymal Cilia Is Attenuated by Antipneumolysin Antibody

    OpenAIRE

    Hirst, Robert A; Mohammed, Bashir J.; Mitchell, Timothy J.; Andrew, Peter W.; O'Callaghan, Christopher

    2004-01-01

    Ciliated ependymal cells line the ventricular surfaces and aqueducts of the brain. In ex vivo experiments, pneumolysin caused rapid inhibition of the ependymal ciliary beat frequency and caused ependymal cell disruption. Wild-type pneumococci and pneumococci deficient in pneumolysin caused ciliary slowing, but penicillin lysis of wild-type, not pneumolysin-deficient, pneumococci increased the extent of ciliary inhibition. This effect was abolished by antipneumolysin antibody. Ependymal ciliar...

  18. Potent inhibition of drug-resistant HIV protease variants by monoclonal antibodies

    Czech Academy of Sciences Publication Activity Database

    Bartoňová, Vanda; Král, Vlastimil; Sieglová, Irena; Brynda, Jiří; Fábry, Milan; Hořejší, Magdalena; Kožíšek, Milan; Grantz Šašková, Klára; Konvalinka, Jan; Sedláček, Juraj; Řezáčová, Pavlína

    2008-01-01

    Roč. 78, č. 3 (2008), s. 275-277. ISSN 0166-3542 R&D Projects: GA MZd NR8571 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z40550506 Keywords : HIV protease * drug resistance * Inhibiting antibody Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.613, year: 2008

  19. Antibody-dependent enhancement of dengue virus infection is inhibited by SA-17, a doxorubicin derivative.

    Science.gov (United States)

    Ayala-Nuñez, Nilda V; Jarupathirun, Patsaporn; Kaptein, Suzanne J F; Neyts, Johan; Smit, Jolanda M

    2013-10-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus (DENV)-induced disease during a heterologous re-infection. Despite ADE's clinical impact, only a few antiviral compounds have been assessed for their anti-ADE activity. We reported earlier that SA-17, a doxorubicin derivative, efficiently inhibits the in vitro infection of DENV and yellow fever virus. Here we explored SA-17's mechanism of inhibition and investigated if the compound is active against ADE of DENV infection. Since enhanced infectivity stimulated by antibodies has been observed with standard and immature DENV, both types of virions were included in the study. We observed that SA-17 (i) inhibits DENV infection by preventing binding/entry to the cell and (ii) interferes with antibody-mediated infection of both standard and immature DENV2. SA-17 markedly reduced the infectivity of DENV2 in ADE conditions, with IC50s ranging from 0.26 to 2.89μM. The compound exerted its activity when added before, during, and after antibody-opsonization of standard and immature virus. Thus, molecules with the characteristics of SA-17 may be attractive antiviral agents since they can be used both to block DENV2 entry during primary and secondary infection and to inhibit ADE of standard and immature virus. PMID:23994499

  20. Different mechanisms are involved in the antibody mediated inhibition of ligand binding to the urokinase receptor

    DEFF Research Database (Denmark)

    List, K; Høyer-Hansen, G; Rønne, E;

    1999-01-01

    Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance or...

  1. Neutralizing antibodies are unable to inhibit direct viral cell-to-cell spread of human cytomegalovirus.

    Science.gov (United States)

    Jacob, Christian L; Lamorte, Louie; Sepulveda, Eliud; Lorenz, Ivo C; Gauthier, Annick; Franti, Michael

    2013-09-01

    Infection with human cytomegalovirus (CMV) during pregnancy is the most common cause of congenital disorders, and can lead to severe life-long disabilities with associated high cost of care. Since there is no vaccine or effective treatment, current efforts are focused on identifying potent neutralizing antibodies. A panel of CMV monoclonal antibodies identified from patent applications, was synthesized and expressed in order to reproduce data from the literature showing that anti-glycoprotein B antibodies neutralized virus entry into all cell types and that anti-pentameric complex antibodies are highly potent in preventing virus entry into epithelial cells. It had not been established whether antibodies could prevent subsequent rounds of infection that are mediated primarily by direct cell-to-cell transmission. A thorough validation of a plaque reduction assay to monitor cell-to-cell spread led to the conclusion that neutralizing antibodies do not significantly inhibit plaque formation or reduce plaque size when they are added post-infection. PMID:23849792

  2. Characterization of antibody-mediated inhibition of Pseudomonas aeruginosa adhesion to epithelial cells.

    OpenAIRE

    Sexton, M; Reen, D J

    1992-01-01

    An enzyme-linked immunosorbent assay system was developed and used to study adhesion of Pseudomonas aeruginosa to human epithelial cells and the abilities of specific antibodies to inhibit this process. Human buccal epithelial cells coated onto microtiter plates were incubated with P. aeruginosa suspensions, and adherent bacteria were detected by using anti-P. aeruginosa serum and a horseradish peroxidase-conjugated secondary antiserum. Adhesion, quantitated as an increase in A405, varied lin...

  3. Antibody

    Science.gov (United States)

    An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Examples ... microorganisms (bacteria, fungi, parasites, and viruses) and chemicals. Antibodies may be produced when the immune system mistakenly ...

  4. A human monoclonal antibody which inhibits the coaggregation activity of Porphyromonas gingivalis.

    OpenAIRE

    Abiko, Y; Ogura, N; Matsuda, U; Yanagi, K.; Takiguchi, H

    1997-01-01

    A B-cell line producing a human monoclonal antibody (HuMAb) against a recombinant 40-kDa outer membrane protein (OMP) of Porphyromonas gingivalis was constructed by in vivo immunization of a severe combined immunodeficiency C.B.-17/Icr mouse, which had been injected with human peripheral blood lymphocytes, with recombinant 40-kDa OMP and subsequent Epstein-Barr virus immortalization of B cells isolated from the spleen of the mouse. This HuMAb inhibited coaggregation between P. gingivalis vesi...

  5. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt;

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited in a...

  6. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt;

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited...

  7. Antibodies binding the ADAM10 substrate recognition domain inhibit Eph function.

    Science.gov (United States)

    Atapattu, Lakmali; Saha, Nayanendu; Llerena, Carmen; Vail, Mary E; Scott, Andrew M; Nikolov, Dimitar B; Lackmann, Martin; Janes, Peter W

    2012-12-15

    The ADAM10 transmembrane metalloprotease cleaves a variety of cell surface proteins that are important in disease, including ligands for receptor tyrosine kinases of the erbB and Eph families. ADAM10-mediated cleavage of ephrins, the ligands for Eph receptors, is suggested to control Eph/ephrin-mediated cell-cell adhesion and segregation, important during normal developmental processes, and implicated in tumour neo-angiogenesis and metastasis. We previously identified a substrate-binding pocket in the ADAM10 C domain that binds the EphA/ephrin-A complex thereby regulating ephrin cleavage. We have now generated monoclonal antibodies specifically recognising this region of ADAM10, which inhibit ephrin cleavage and Eph/ephrin-mediated cell function, including ephrin-induced Eph receptor internalisation, phosphorylation and Eph-mediated cell segregation. Our studies confirm the important role of ADAM10 in cell-cell interactions mediated by both A- and B-type Eph receptors, and suggest antibodies against the ADAM10 substrate-recognition pocket as promising therapeutic agents, acting by inhibiting cleavage of ephrins and potentially other ADAM10 substrates. PMID:23108669

  8. Complement Inhibition for Prevention and Treatment of Antibody-Mediated Rejection in Renal Allograft Recipients.

    Science.gov (United States)

    Jordan, S C; Choi, J; Kahwaji, J; Vo, A

    2016-04-01

    Therapeutic interventions aimed at the human complement system are recognized as potentially important strategies for the treatment of inflammatory and autoimmune diseases because there is often evidence of complement-mediated injury according to pathologic assessments. In addition, there are a large number of potential targets, both soluble and cell bound, that might offer potential for new drug development, but progress in this area has met with significant challenges. Currently, 2 drugs are approved aimed at inhibition of complement activation. The first option is eculizumab (anti-C5), which is approved for the treatment of paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome. Eculizumab has also been studied in human transplantation for the treatment and prevention of antibody-mediated rejection (ABMR). Initial data from uncontrolled studies suggested a significant benefit of eculizumab for the prevention of ABMR in highly HLA-sensitized patients, but a subsequent randomized, placebo-controlled trial failed to meet its primary endpoint. Anecdotal data, primarily from case studies, showed benefits in treating complement-mediated ABMR. A second approved complement-inhibiting therapy is C1 esterase inhibitor (C1-INH), which is approved for use in patients with hereditary angioedema, a condition caused by mutations in the gene that codes for C1-INH. A recent placebo-controlled trial of C1-INH for prevention of ABMR in HLA-sensitized patients found that the drug was safe, with evidence for inhibition of systemic complement activation and complement-activating donor-specific antibodies. Other drugs are now under development. PMID:27234741

  9. INHIBITION OF Acinetobacter baumannii ADHESION BY ANTI-FIMBRIAL ANTIBODY: THE FIMBRIAL ANTIGEN EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Hadeel K. Musafer

    2013-01-01

    Full Text Available Collecting samples of Acinetobacter baumannii taken from different clinical cases of wounds, septicemia, and urinary tract infections. That was accomplished by taking (296 samples from Baghdad educational hospital and Ibn-al-Baladi hospital. Samples were cultured on solid media (McConkey and blood agars, and according to microscopical, cultural, and biochemical identification, in addition to using API 20-E system, (21 isolates of A. baumannii were identified and in percentage of 47.619, 9.523, 14.285, and 28.571 for wound, blood, sputum, and urine samples, respectively. Methods: detection of fimbriated bacterial isolates among 21 isolates, and all those isolated were fimbriae forming isolates; isolate number (9 was selected as an effective isolate in formation of fimbriae. Non-forming fimbriae isolate of Shigella flexneri is used as negative control. Results and Conclusion: the average of adherence of fimbriated bacterial cell with human epithelial cells was reached (50 adherent bacterial cell per epithelial cell compared with the average of adherence of control isolate (12 adherent bacterial cell per epithelial cell, the inhibition processes are performed: Inhibition of bacterial adherence by specific antibodies of fimbriae antigen showed inhibition effect of adherence in respect to fimbriated isolate A. baumannii 9 also the subminimum inhibitory concentration for four antibiotics (Gentamicin, Tobramycin, Cefepime, and Amikacin inhibit the adherence of fimbriated isolate. The isolates (used in the study have the ability to agglutinate Saccharomyces cerevisiae and human red blood corpuscles (RBCs. The study of effect of different fimbriae extract concentrations (25, 50, 100 μg/ml on immune cells; consequently, reached to the following results: Concentrations of (25, 50, 100 μg/ml showed a negative effect on lymphocyte and PMNs viability which increased significantly (P≤0.05 with increasing of fimbriae extract concentration. On the other hand

  10. Inhibition of Neisseria gonorrhoeae attachment to HeLa cells with monoclonal antibody directed against a protein II.

    OpenAIRE

    Sugasawara, R J; Cannon, J G; Black, W J; Nachamkin, I; Sweet, R L; Brooks, G F

    1983-01-01

    This study showed that a protein II (PII) of Neisseria gonorrhoeae FA1090 appeared to act as a mediator of attachment to HeLa cells. Two colony variants of FA1090 were selected. Both gonococcal variants were nonpiliated, but one contained a PII and the other did not. A monoclonal antibody (1090-10.1), which was directed against the PII, inhibited the apparent PII-mediated attachment to HeLa cells. Antibodies produced from clone 1035-4, which had no PII specificity, did not inhibit the attachm...

  11. Platelet-collagen interaction: inhibition by a monoclonal antibody raised against collagen receptor

    International Nuclear Information System (INIS)

    The authors have previously reported that polyclonal antibody raised against the purified platelet collagen receptor cross reacted with glycoprotein IIb-IIIa complex of platelets. In order to study the receptor function further, the authors prepared a monoclonal antibody to the collagen receptor (65K). Platelet collagen receptor was purified as described previously by the authors. Mice were immunized by injection of purified 65K protein emulsified in complete Freund's adjuvant, and hybridomas were obtained from the fusion of spleen cells of immunized mice with myeloma cells (SP 2/0). The assay for antibody was performed with enzyme-linked immunosorbent assay. The hybridoma cells producing specific anti-65K protein were subcloned and the subcloned cells were injected into peritoneal cavity of Pristane-Primed mice. Immunoglobulin G(IgG) was isolated from ascitic fluids by an Affigel Blue chromatography. The Fab' fragments were isolated from papain digested IgG followed by an Affigel Blue chromatography. Immunoblot experiments using the monoclonal IgG of solubilized platelet membrane proteins following NaDodSO4-polyacrylamide gel electrophoresis showed that the monoclonal IgG reacted with the antigen specifically. It did not react with glycoprotein IIb-IIIa. The isolated IgG and Fab' fragments inhibited competitively the binding of radiolabelled α1(I) to washed platelets and soluble collagen- as well as fibrillar collagen-induced but not ADP-induced platelet aggregation. This indicates that collagen-induced platelet aggregation is mediated through interaction of collagen with 65K platelet receptor

  12. Platelet-collagen interaction: inhibition by a monoclonal antibody raised against collagen receptor

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, T.; Jin, A.; Kang, A.

    1986-05-01

    The authors have previously reported that polyclonal antibody raised against the purified platelet collagen receptor cross reacted with glycoprotein IIb-IIIa complex of platelets. In order to study the receptor function further, the authors prepared a monoclonal antibody to the collagen receptor (65K). Platelet collagen receptor was purified as described previously by the authors. Mice were immunized by injection of purified 65K protein emulsified in complete Freund's adjuvant, and hybridomas were obtained from the fusion of spleen cells of immunized mice with myeloma cells (SP 2/0). The assay for antibody was performed with enzyme-linked immunosorbent assay. The hybridoma cells producing specific anti-65K protein were subcloned and the subcloned cells were injected into peritoneal cavity of Pristane-Primed mice. Immunoglobulin G(IgG) was isolated from ascitic fluids by an Affigel Blue chromatography. The Fab' fragments were isolated from papain digested IgG followed by an Affigel Blue chromatography. Immunoblot experiments using the monoclonal IgG of solubilized platelet membrane proteins following NaDodSO/sub 4/-polyacrylamide gel electrophoresis showed that the monoclonal IgG reacted with the antigen specifically. It did not react with glycoprotein IIb-IIIa. The isolated IgG and Fab' fragments inhibited competitively the binding of radiolabelled ..cap alpha..1(I) to washed platelets and soluble collagen- as well as fibrillar collagen-induced but not ADP-induced platelet aggregation. This indicates that collagen-induced platelet aggregation is mediated through interaction of collagen with 65K platelet receptor.

  13. Monoclonal Antibodies that Inhibit the Proteolytic Activity of Botulinum Neurotoxin Serotype/B

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    Yongfeng Fan

    2015-08-01

    Full Text Available Existing antibodies (Abs used to treat botulism cannot enter the cytosol of neurons and bind to botulinum neurotoxin (BoNT at its site of action, and thus cannot reverse paralysis. However, Abs targeting the proteolytic domain of the toxin could inhibit the proteolytic activity of the toxin intracellularly and potentially reverse intoxication, if they could be delivered intracellularly. As such, antibodies that neutralize toxin activity could serve as potent inhibitory cargos for therapeutic antitoxins against botulism. BoNT serotype B (BoNT/B contains a zinc endopeptidase light chain (LC domain that cleaves synaoptobrevin-2, a SNARE protein responsible for vesicle fusion and acetylcholine vesicle release. To generate monoclonal Abs (mAbs that could reverse paralysis, we targeted the protease domain for Ab generation. Single-chain variable fragment (scFv libraries from immunized mice or humans were displayed on yeast, and 19 unique BoNT/B LC-specific mAbs isolated by fluorescence-activated cell sorting (FACS. The equilibrium dissociation constants (KD of these mAbs for BoNT/B LC ranged from 0.24 nM to 14.3 nM (mean KD 3.27 nM. Eleven mAbs inhibited BoNT/B LC proteolytic activity. The fine epitopes of selected mAbs were identified by alanine-scanning mutagenesis, revealing that inhibitory mAbs bound near the active site, substrate-binding site or the extended substrate-binding site. The results provide mAbs that could prove useful for intracellular reversal of paralysis and identify epitopes that could be targeted by small molecules inhibitors.

  14. SSB peptide and DNA co-immunization induces inhibition of anti-dsDNA antibody production in rabbits

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Patients with systemic lupus erythematosus often have various autoantibodies.The relationship between these antibodies is still poorly understood.The aim of the present study was to observe the anti-SSB antibody and anti-dsDNA antibody production profiles following immunization with synthetic SSB peptide alone,DNA alone or co-immunization with these two antigens.Methods SSB 214-225 aa peptide was synthesized by organic chemistry solid-phase peptide synthesis.Rabbits were immunized with the foliowing antigens:synthetic SSB peptide linked with keyhole limpet hemocyanin (KLH),DNA,SSB plus dsDNA,KLH and PBS.Antibodies were measured by ELISA.Histopathology and direct immufluorescence assays were also applied.Results Ainit-SSB and anti-dsDNA antibodies were produced following immunization with SSB peptide and DNA respectively.The level of SSB antibody in the co-immunization group was higher than that of the SSB peptide immunization group.The level of anti-dsDNA antibody in the co-immunization group was,however,lower than that in the DNA immunization group.Meanwhile,the level of anti-SSB antibody was higher than that of anti-DNA antibody in the co-immunization group.No morphological or immunological abnormalities were found in the heart,liver,kidney,spleen or skin tissues.Conclusion Inhibition of anti-dsDNA-antibody was induced by co-immunization with synthesized SSB peptide and DNA,which might explain,at least partly,the mild disease in some LE subsets associated with SSB antibody.

  15. Aggregation of macrophages and fibroblasts is inhibited by a monoclonal antibody to the hyaluronate receptor

    Energy Technology Data Exchange (ETDEWEB)

    Green, S.J.; Underhill, C.B. (Georgetown Univ. Medical Center, Washington, DC (USA)); Tarone, G. (Univ. of Turin (Italy))

    1988-10-01

    To examine the role of the hyaluronate receptor in cell to cell adhesion, the authors have employed the K-3 monoclonal antibody (MAb) which specifically binds to the hyaluronate receptor and blocks its ability to interact with hyaluronate. In the first set of experiments, they investigated the spontaneous aggregation of SV-3T3 cells, which involves two distinct mechanisms, one of which is dependent upon the presence of divalent cation and the other is independent. The divalent cation-independent aggregation was found to be completely inhibited by both intact and Fab fragments of the K-3 MAb. In contrast, the K-3 MAb had no effect on the divalent cation-dependent aggregation of cells. In a second set of experiments, we examined alveolar macrophages. The presence of hyaluronate receptors on alveolar macrophages was demonstrated by the fact that detergent extracts of these cells could bind ({sup 3})hyaluronate, and this binding was blocked by the K-3 MAb. Immunoblot analysis of alveolar macrophages showed that the hyaluronate receptor had a M{sub r} of 99,500, which is considerably larger than the 85,000 M{sub r} for that on BHK cells. When hyaluronate was added to suspensions of alveolar macrophages, the cells were induced to aggregate. This effect was inhibited by the K-3 MAb, suggesting that the hyaluronate-induced aggregation was mediated by the receptor.

  16. A function blocking anti-mouse integrin α5β1 antibody inhibits angiogenesis and impedes tumor growth in vivo

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    Powers David

    2007-11-01

    Full Text Available Abstract Background Integrins are important adhesion molecules that regulate tumor and endothelial cell survival, proliferation and migration. The integrin α5β1 has been shown to play a critical role during angiogenesis. An inhibitor of this integrin, volociximab (M200, inhibits endothelial cell growth and movement in vitro, independent of the growth factor milieu, and inhibits tumor growth in vivo in the rabbit VX2 carcinoma model. Although volociximab has already been tested in open label, pilot phase II clinical trials in melanoma, pancreatic and renal cell cancer, evaluation of the mechanism of action of volociximab has been limited because this antibody does not cross-react with murine α5β1, precluding its use in standard mouse xenograft models. Methods We generated a panel of rat-anti-mouse α5β1 antibodies, with the intent of identifying an antibody that recapitulated the properties of volociximab. Hybridoma clones were screened for analogous function to volociximab, including specificity for α5β1 heterodimer and blocking of integrin binding to fibronectin. A subset of antibodies that met these criteria were further characterized for their capacities to bind to mouse endothelial cells, inhibit cell migration and block angiogenesis in vitro. One antibody that encompassed all of these attributes, 339.1, was selected from this panel and tested in xenograft models. Results A panel of antibodies was characterized for specificity and potency. The affinity of antibody 339.1 for mouse integrin α5β1 was determined to be 0.59 nM, as measured by BIAcore. This antibody does not significantly cross-react with human integrin, however 339.1 inhibits murine endothelial cell migration and tube formation and elicits cell death in these cells (EC50 = 5.3 nM. In multiple xenograft models, 339.1 inhibited the growth of established tumors by 40–60% (p Conclusion The results herein demonstrate that 339.1, like volociximab, exhibits potent anti-α5β1

  17. Detection of thrombocytic antibodies with the direct and indirect haemolysis inhibition test and the radioimmuno-Coombs test

    International Nuclear Information System (INIS)

    Methods of application of the direct and indirect haemolysis inhibition test were studied in order to optimise the test parameters: The ultimate aim was to standardize the test method and compare its sensitivity in detecting various platelet antibodies with platelet indirect radioactive Coombs-test and the platelet immunofluorescence test. (orig.)

  18. Antibodies against the Plasmodium falciparum glutamate-rich protein from naturally exposed individuals living in a Brazilian malaria-endemic area can inhibit in vitro parasite growth

    DEFF Research Database (Denmark)

    Pratt-Riccio, Lilian Rose; Bianco, Cesare; Totino, Paulo Renato Rivas;

    2011-01-01

    The glutamate-rich protein (GLURP) is an exoantigen expressed in all stages of the Plasmodium falciparum life cycle in humans. Anti-GLURP antibodies can inhibit parasite growth in the presence of monocytes via antibody-dependent cellular inhibition (ADCI), and a major parasite-inhibitory region h...

  19. High concentrations of therapeutic IgG1 antibodies are needed to compensate for inhibition of antibody-dependent cellular cytotoxicity by excess endogenous immunoglobulin G.

    Science.gov (United States)

    Preithner, Susanne; Elm, Stefanie; Lippold, Sandra; Locher, Mathias; Wolf, Andreas; da Silva, Antonio J; Baeuerle, Patrick A; Prang, Nadja S

    2006-03-01

    A common feature of human IgG1 antibodies used for cancer treatment is that their anti-tumour efficacy requires high serum trough levels and continued therapy for several months. Treatment cycles, thereby, consume several grams of IgG1 translating into significant drug needs and costs. The basis for the low in vivo efficacy, which is in contrast to high in vitro antibody-dependent cellular cytotoxicity (ADCC), is not well understood. Here, we have explored factors contributing to this discrepancy using adecatumumab (MT201), a fully human monoclonal IgG1 against epithelial cell adhesion molecule (Ep-CAM) and trastuzumab (Herceptin), a humanized IgG1 with specificity for the human epithelial growth factor receptor type 2 (HER-2) antigen. We found that physiological levels of human sera strongly inhibited ADCC of both IgG1 antibodies. Effects showed some dependence on the density of Ep-CAM and HER-2 targets, the tumour cell line tested and on effector cell and serum donors. Removal of IgG by affinity chromatography abolished the inhibitory effect of a serum pool. Inhibition of ADCC was fully restored by adding back the IgG fraction or by an equal amount of IgG from a commercial source. We further demonstrate that CD56-positive lymphocytes within human PBMC contributed >90% to ADCC and that normal serum levels of IgG effectively competed for in vitro binding of an IgG1 antibody to low-affinity Fcgamma receptor type III (CD16), as is present on natural killer (NK) cells. Competition of serum IgG for binding of therapeutic IgG1 to NK cell may be one important reason why high antibody doses are required in the clinic for treatment of cancer by an ADCC-based mechanism. PMID:16102830

  20. Wnt isoform-specific interactions with coreceptor specify inhibition or potentiation of signaling by LRP6 antibodies.

    Science.gov (United States)

    Gong, Yan; Bourhis, Eric; Chiu, Cecilia; Stawicki, Scott; DeAlmeida, Venita I; Liu, Bob Y; Phamluong, Khanhky; Cao, Tim C; Carano, Richard A D; Ernst, James A; Solloway, Mark; Rubinfeld, Bonnee; Hannoush, Rami N; Wu, Yan; Polakis, Paul; Costa, Mike

    2010-01-01

    β-Catenin-dependent Wnt signaling is initiated as Wnt binds to both the receptor FZD and coreceptor LRP5/6, which then assembles a multimeric complex at the cytoplasmic membrane face to recruit and inactivate the kinase GSK3. The large number and sequence diversity of Wnt isoforms suggest the possibility of domain-specific ligand-coreceptor interactions, and distinct binding sites on LRP6 for Wnt3a and Wnt9b have recently been identified in vitro. Whether mechanistically different interactions between Wnts and coreceptors might mediate signaling remains to be determined. It is also not clear whether coreceptor homodimerization induced extracellularly can activate Wnt signaling, as is the case for receptor tyrosine kinases. We generated monoclonal antibodies against LRP6 with the unexpected ability to inhibit signaling by some Wnt isoforms and potentiate signaling by other isoforms. In cell culture, two antibodies characterized further show reciprocal activities on most Wnts, with one antibody antagonizing and the other potentiating. We demonstrate that these antibodies bind to different regions of LRP6 protein, and inhibition of signaling results from blocking Wnt binding. Antibody-mediated dimerization of LRP6 can potentiate signaling only when a Wnt isoform is also able to bind the complex, presumably recruiting FZD. Endogenous autocrine Wnt signaling in different tumor cell lines can be either antagonized or enhanced by the LRP6 antibodies, indicating expression of different Wnt isoforms. As anticipated from the roles of Wnt signaling in cancer and bone development, antibody activities can also be observed in mice for inhibition of tumor growth and in organ culture for enhancement of bone mineral density. Collectively, our results indicate that separate binding sites for different subsets of Wnt isoforms determine the inhibition or potentiation of signaling conferred by LRP6 antibodies. This complexity of coreceptor-ligand interactions may allow for

  1. Heme Oxygenase-1 Inhibits HLA Class I Antibody-Dependent Endothelial Cell Activation.

    Directory of Open Access Journals (Sweden)

    Eva Zilian

    Full Text Available Antibody-mediated rejection (AMR is a key limiting factor for long-term graft survival in solid organ transplantation. Human leukocyte antigen (HLA class I (HLA I antibodies (Abs play a major role in the pathogenesis of AMR via their interactions with HLA molecules on vascular endothelial cells (ECs. The antioxidant enzyme heme oxygenase (HO-1 has anti-inflammatory functions in the endothelium. As complement-independent effects of HLA I Abs can activate ECs, it was the goal of the current study to investigate the role of HO-1 on activation of human ECs by HLA I Abs. In cell cultures of various primary human macro- and microvascular ECs treatment with monoclonal pan- and allele-specific HLA I Abs up-regulated the expression of inducible proinflammatory adhesion molecules and chemokines (vascular cell adhesion molecule-1 [VCAM-1], intercellular cell adhesion molecule-1 [ICAM-1], interleukin-8 [IL-8] and monocyte chemotactic protein 1 [MCP-1]. Pharmacological induction of HO-1 with cobalt-protoporphyrin IX reduced, whereas inhibition of HO-1 with either zinc-protoporphyrin IX or siRNA-mediated knockdown increased HLA I Ab-dependent up-regulation of VCAM-1. Treatment with two carbon monoxide (CO-releasing molecules, which liberate the gaseous HO product CO, blocked HLA I Ab-dependent EC activation. Finally, in an in vitro adhesion assay exposure of ECs to HLA I Abs led to increased monocyte binding, which was counteracted by up-regulation of HO-1. In conclusion, HLA I Ab-dependent EC activation is modulated by endothelial HO-1 and targeted induction of this enzyme may be a novel therapeutic approach for the treatment of AMR in solid organ transplantation.

  2. An antisperm monoclonal antibody inhibits sperm fusion with zona-free hamster eggs but not homologous eggs.

    Science.gov (United States)

    Primakoff, P; Hyatt, H

    1986-09-01

    The zona-free hamster egg penetration assay (HEPA) was evaluated as a test for identifying fertilization-blocking antibodies. A monoclonal antibody, AH-20, that binds to the surface of guinea pig sperm was used to test antibody inhibition of sperm-egg fusion. AH-20 strongly inhibited guinea pig sperm fusion with zona-free hamster eggs but had no effect on guinea pig sperm fusion with zona-free guinea pig eggs. No inhibition by AH-20 was found in the homologous fusion assay over a wide range of sperm concentration, fertilization rate, and fertilization index. The results suggest that although guinea pig sperm can fuse with both hamster and guinea pig eggs, some aspect of the fusion mechanism is different in the two cases. The findings also indicate that HEPA, which is frequently used to assess the fertility potential of human sperm, can identify as blockers of sperm-egg fusion antibodies that have no effect on homologous sperm-egg fusion. PMID:3527769

  3. A murine monoclonal antibody (VM-1) against human basal cells inhibits the growth of human keratinocytes in culture.

    Science.gov (United States)

    Oseroff, A R; Pfendt, E A; DiCicco, L; Morhenn, V B

    1985-04-01

    Using epidermal cells from psoriatic plaques as the immunogen, an IgG1 murine monoclonal antibody, VM-1, has been produced which stains basal keratinocytes on frozen sections of skin obtained from normal individuals and from psoriatic plaques. In some areas of both normal and psoriatic epidermis, the cell layer immediately above the basal cells is also stained. Cells in the external root sheath of the hair follicles also bind VM-1. The antibody binding site is trypsin-resistant, and is not blocked by bullous pemphigoid serum. If dispersed epidermal cells are preincubated with VM-1 for 1 h or more before plating, the majority of the cells do not attach and spread out on a collagen-coated Petri dish surface or on a fibroblast feeder layer. When added to attached, preconfluent cultures of keratinocytes, VM-1 inhibits growth and alters cell morphology. The growth inhibition is specific for keratinocytes, and viability studies show that it is not due to an immediate toxic effect of the antibody. The VM-1-induced inhibition of keratinocyte growth is not reversed by soy bean or lima bean trypsin inhibitors added at the time of cell plating or at the time of addition of antibody. PMID:3981036

  4. Cytoskeletal inhibitors, anti-adhesion molecule antibodies, and lectins inhibit hepatocyte spheroid formation.

    Directory of Open Access Journals (Sweden)

    Nakamura M

    2002-02-01

    Full Text Available We investigated the role of cytoskeletons, adhesion molecules, membrane-glycosylations, and proteoglycans in forming the shape of adult rat hepatocyte spheroids. Isolated hepatocytes were cultured on dishes coated with chondroitin sulfate phosphatidyl ethanolamine (CS-PE. Spheroid-forming ability was observed after adding cytoskeletal inhibitors (cytochalasin D, colchicine, okadaic acid, mycalolide B, anti-adhesion molecule antibodies (anti-E-cadherin, anti-connexin 32, anti-zo-1, a glycosphingolipid synthetic inhibitor (N-butyldeoxynojirimycin, a proteoglycan synthetic inhibitor (p-nitrophenyl-beta-D-xylopyranoside, and several lectins. Localization of actin was studied using confocal microscopy after rhodamine-phalloidin staining. Adding cytoskeletal inhibitors on the initial day resulted in weakly clustered cell aggregates rather than smoothly formed spheroids. These effects disappeared at lower reagent concentrations. When reagents were added on day 3, after the formation of spheroids, only mycalolide B was associated with an irregular spheroid surface; the others had no effect. Adding the anti-E-cadherin, anti-connexin 32 on the initial day showed inhibition of spheroid formation, but anti-zo-1 and proteoglycan synthetic inhibitor had no effects. Among the several lectins, only Wheat Germ Agglutinin (WGA, Ricinus communis Agglutinin I (RCA-I, and Concanavalin A (ConA showed inhibition. These results suggest that cytoskeletal conformation and some adhesion molecules are necessary to form spheroids. Based on the interactions between lectins and hepatocytes in the present study, hepatocytes appear to contain an N-linked complex or N-linked hybrid glycosylated chains.

  5. A novel monoclonal antibody of human stem cell factor inhibits umbilical cord blood stem cell ex vivo expansion

    Directory of Open Access Journals (Sweden)

    Fan Jie

    2012-12-01

    Full Text Available Abstract Stem cell factor (SCF activates hematopoietic stem cell (HSC self-renewal and is being used to stimulate the ex vivo expansion of HSCs. The mechanism by which SCF supports expansion of HSCs remains poorly understood. In cord blood ex vivo expansion assays, a newly produced anti-SCF monoclonal antibody (clone 23C8 was found to significantly inhibit the expansion of CD34+ cells. This antibody appears to bind directly to a part of SCF that is critical for biological activity toward expansion of CD34+ cells, which is located in the first 104 amino acids from the NH2-terminus.

  6. INHIBITION OF HUMAN EXPERIMENTAL GASTRIC CARCINOMA METASTASIS IN VIVO BY P-SELECTIN MONOCLONAL ANTIBODY

    Institute of Scientific and Technical Information of China (English)

    陈金联; 陈维雄; 朱金水; 陈尼维; 姚明; 周同

    2001-01-01

    Objeetive To study the role of cell adhesion molecule P-selectin monoclonal antibody ( MAb ) in tumor metastasis of an orthotopic metastatic model. Methods SCID mice were implanted orthotopically SGC-7901 human gastric cancer tissue. 3d later, animals received i. v. injections of PBS or P-selectin MAb ( 100μg /injection ) twice weekly for 3 weeks. 42d after operation, all animals were sacrificed. Tissues from all organs were obtained for histopathological evaluation. Results 10 of the animals ( n = 11 ) treated with PBS were found to develop metastatic tumors in the regional lymph nodes, liver, and lung. In contrast, 2 of the animals ( n = 9 ) treated with P-selectin MAb developed metastatic tumors in the organs examined. The expression of P-selectin mRNA in gastric cancer tissue of SCID mice with tumor metastasis was higher than that without such metastasis. Conclusion P-selectin expression is associated with tumor metastasis, and the metastasis may be inhibited by the MAb.

  7. Serological diagnosis of bovine neosporosis by Neospora caninum monoclonal antibody-based competitive inhibition enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Baszler, T V; Knowles, D P; Dubey, J P; Gay, J M; Mathison, B A; McElwain, T F

    1996-06-01

    Neospora caninum, a protozoan parasite closely related to Toxoplasma gondii, causes abortion and congenital infection in cattle. To investigate specific methods of antemortem diagnosis, the antibody responses of infected cows were evaluated by immunoblot assay and competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) by using a monoclonal antibody (MAb), MAb 4A4-2, against N. caninum tachyzoites. MAb 4A4-2 bound diffusely to the exterior surface of N. caninum tachyzoites and recognized a single 65-kDa band in immunoblots. MAb 4A4-2 was unreactive to antigens of two closely related apicomplexan protozoa, Toxoplasma gondii and Sarcocystis cruzi. Binding of MAb 4A4-2 was inhibited by mild periodate treatment of N. caninum antigen, demonstrating the carbohydrate nature of the epitope. Immunoblot analysis of N. caninum tachyzoite antigens with sera from cows with confirmed Neospora-induced abortion revealed at minimum 14 major antigens ranging from 11 to 175 kDa. Although the recognized antigens varied from cow to cow, antigens of 116, 65, and 25 kDa were detected in all cows with abortion confirmed to be caused by N. caninum. The binding of MAb 4A4-2 to N. caninum tachyzoite antigen was consistently inhibited by sera from Neospora-infected cows in a CI-ELISA format and was not inhibited by sera from Neospora antibody-negative cows. Furthermore, sera from cattle experimentally infected with T. gondii, S. cruzi, Sarcocystis hominis, or Sarcocystis hirsuta, which had cross-reactive antibodies recognizing multiple N. caninum antigens by immunoblot assay, did not inhibit binding of MAb 4A4-2 in the CI-ELISA. Thus, MAb 4A4-2 binds a carbohydrate epitope on a single N. caninum tachyzoite surface antigen that is recognized consistently and specifically by Neospora-infected cattle. PMID:8735092

  8. Comparison of serum hemagglutinin and neuraminidase inhibition antibodies after 2010-2011 trivalent inactivated influenza vaccination in healthcare personnel.

    Science.gov (United States)

    Laguio-Vila, Maryrose R; Thompson, Mark G; Reynolds, Sue; Spencer, Sarah M; Gaglani, Manjusha; Naleway, Allison; Ball, Sarah; Bozeman, Sam; Baker, Steven; Martínez-Sobrido, Luis; Levine, Min; Katz, Jackie; Fry, Alicia M; Treanor, John J

    2015-01-01

    Background.  Most inactivated influenza vaccines contain purified and standardized hemagglutinin (HA) and residual neuraminidase (NA) antigens. Vaccine-associated HA antibody responses (hemagglutination inhibition [HAI]) are well described, but less is known about the immune response to the NA. Methods.  Serum of 1349 healthcare personnel (HCP) electing or declining the 2010-2011 trivalent-inactivated influenza vaccine ([IIV3], containing A/California/7/2009 p(H1N1), A/Perth/16/2009 [H3N2], B/Brisbane/60/2008 strains) were tested for NA-inhibiting (NAI) antibody by a modified lectin-based assay using pseudotyped N1 and N2 influenza A viruses with an irrelevant (H5) HA. Neuraminidase-inhibiting and HAI antibody titers were evaluated approximately 30 days after vaccination and end-of-season for those with polymerase chain reaction (PCR)-confirmed influenza infection. Results.  In 916 HCP (68%) receiving IIV3, a 2-fold increase in N1 and N2 NAI antibody occurred in 63.7% and 47.3%, respectively. Smaller responses occurred in HCP age >50 years and those without prior 2009-2010 IIV3 nor monovalent A(H1N1)pdm09 influenza vaccinations. Forty-four PCR-confirmed influenza infections were observed, primarily affecting those with lower pre-exposure HAI and NAI antibodies. Higher pre-NAI titers correlated with shorter duration of illness for A(H1N1)pdm09 virus infections. Conclusions.  Trivalent-inactivated influenza vaccine is modestly immunogenic for N1 and N2 antigens in HCP. Vaccines eliciting robust NA immune responses may improve efficacy and reduce influenza-associated morbidity. PMID:25884004

  9. Neutralizing monoclonal antibodies against hepatitis C virus E2 protein bind discontinuous epitopes and inhibit infection at a postattachment step

    DEFF Research Database (Denmark)

    Sabo, Michelle C; Luca, Vincent C; Prentoe, Jannick; Hopcraft, Sharon E; Blight, Keril J; Yi, Minkyung; Lemon, Stanley M; Ball, Jonathan K; Bukh, Jens; Evans, Matthew J; Fremont, Daved H; Diamond, Michael S

    2011-01-01

    infection at an early postattachment step. Receptor binding studies demonstrated that H77.39 inhibited binding of soluble E2 protein to both CD81 and SR-B1, J6.36 blocked attachment to SR-B1 and modestly reduced binding to CD81, and H77.16 blocked attachment to SR-B1 only. Using yeast surface display, we......The E2 glycoprotein of hepatitis C virus (HCV) mediates viral attachment and entry into target hepatocytes and elicits neutralizing antibodies in infected patients. To characterize the structural and functional basis of HCV neutralization, we generated a novel panel of 78 monoclonal antibodies...... (MAbs) against E2 proteins from genotype 1a and 2a HCV strains. Using high-throughput focus-forming reduction or luciferase-based neutralization assays with chimeric infectious HCV containing structural proteins from both genotypes, we defined eight MAbs that significantly inhibited infection of the...

  10. Leishmania (Viannia) braziliensis nucleoside triphosphate diphosphohydrolase (NTPDase 1): localization and in vitro inhibition of promastigotes growth by polyclonal antibodies.

    Science.gov (United States)

    Porcino, Gabriane Nascimento; Carvalho-Campos, Cristiane; Maia, Ana Carolina Ribeiro Gomes; Detoni, Michelle Lima; Faria-Pinto, Priscila; Coimbra, Elaine Soares; Marques, Marcos José; Juliano, Maria Aparecida; Juliano, Luiz; Diniz, Vanessa Álvaro; Corte-Real, Suzana; Vasconcelos, Eveline Gomes

    2012-10-01

    Nucleoside triphosphate diphosphohydrolase (NTPDase) activity was recently characterized in Leishmania (Viannia) braziliensis promastigotes (Lb), and an antigenic conserved domain (r82-121) from the specific NTPDase 1 isoform was identified. In this work, mouse polyclonal antibodies produced against two synthetic peptides derived from this domain (LbB1LJ, r82-103; LbB2LJ, r102-121) were used. The anti-LbB1LJ or anti-LbB2LJ antibodies were immobilized on protein A-sepharose and immunoprecipitated the NTPDase 1 of 48 kDa and depleted approximately 40% of the phosphohydrolytic activity from detergent-homogenized Lb preparation. Ultrastructural immunocytochemical microscopy identified the NTPDase 1 on the parasite surface and in its subcellular cytoplasmic vesicles, mitochondria, kinetoplast and nucleus. The ATPase and ADPase activities of detergent-homogenized Lb preparation were partially inhibited by anti-LbB1LJ antibody (43-79%), which was more effective than that inhibition (18-47%) by anti-LbB2LJ antibody. In addition, the immune serum anti-LbB1LJ (67%) or anti-LbB2LJ (33%) was cytotoxic, significantly reducing the promastigotes growth in vitro. The results appoint the conserved domain from the L. braziliensis NTPDase as an important target for inhibitor design and the potential application of these biomolecules in experimental protocols of disease control. PMID:22921497

  11. IL-6 blockade by monoclonal antibodies inhibits apolipoprotein (a) expression and lipoprotein (a) synthesis in humans[S

    OpenAIRE

    Müller, Nike; Schulte, Dominik M.; Türk, Kathrin; Freitag-Wolf, Sandra; Hampe, Jochen; Zeuner, Rainald; Johann O Schröder; Gouni-Berthold, Ioanna; Heiner K Berthold; Krone, Wilhelm; Rose-John, Stefan; Schreiber, Stefan; Laudes, Matthias

    2015-01-01

    Lipoprotein (a) [Lp(a)] is a highly atherogenic lipid particle. Although earlier reports suggested that Lp(a) levels are mostly determined by genetic factors, several recent studies have revealed that Lp(a) induction is also caused by chronic inflammation. Therefore, we aimed to examine whether cytokine blockade by monoclonal antibodies may inhibit Lp(a) metabolism. We found that interleukin 6 (IL-6) blockade by tocilizumab (TCZ) reduced Lp(a) while TNF-α-inhibition by adalimumab in humans ha...

  12. Radiometric cytolysis inhibition assay, a new rapid test for neutralizing antibodies to intact and trypsin-cleaved poliovirus

    International Nuclear Information System (INIS)

    We have developed a new rapid test, the radiometric cytolysis inhibition assay (RACINA), for the determination of neutralizing poliovirus antibodies. HeLa cells prelabeled with 51Cr, [3H]leucine, or, preferentially, with [3H]uridine are used as sensitive quantitative indicators of residual infectious virus. Both suspensions and monolayer cultures of the indicator cells can be used. Neutralization of a fraction of a high-titer virus preparation can be scored after the first replication cycle at 8 to 10 h. By lowering the incubation temperature to 30 degree C, the completion of the cytolysis due to the first replication cycle of poliovirus was delayed beyond 21 h. This makes it possible to use the RACINA, unlike the standard microneutralization assay, for measuring antibodies to trypsin-cleaved polioviruses. The RACINA was found to be as sensitive as and more reproducible than the standard microneutralization assay in the measurement of neutralizing poliovirus antibodies. The RACINA is a rapid and reliable test for neutralizing antibodies and in principle it may be applicable for quantitation of neutralizing antibodies to other cytolytic agents as well

  13. Post-streptococcal auto-antibodies inhibit protein disulfide isomerase and are associated with insulin resistance.

    Directory of Open Access Journals (Sweden)

    Adi Aran

    Full Text Available Post-streptococcal autoimmunity affects millions worldwide, targeting multiple organs including the heart, brain, and kidneys. To explore the post-streptococcal autoimmunity spectrum, we used western blot analyses, to screen 310 sera from healthy subjects with (33% and without (67% markers of recent streptococcal infections [anti-Streptolysin O (ASLO or anti-DNAse B (ADB]. A 58 KDa protein, reacting strongly with post-streptococcal sera, was identified as Protein Disulfide Isomerase (PDI, an abundant protein with pleiotropic metabolic, immunologic, and thrombotic effects. Anti-PDI autoantibodies, purified from human sera, targeted similar epitopes in Streptolysin O (SLO, P51-61 and PDI (P328-338. The correlation between post-streptococcal status and anti-human PDI auto-immunity was further confirmed in a total of 2987 samples (13.6% in 530 ASLO positive versus 5.6% in 2457 ASLO negative samples, p<0.0001. Finally, anti-PDI auto-antibodies inhibited PDI-mediated insulin degradation in vitro (n = 90, p<0.001, and correlated with higher serum insulin (14.1 iu/ml vs. 12.2 iu/ml, n = 1215, p = 0.039 and insulin resistance (Homeostatic Model Assessment (HOMA 4.1 vs. 3.1, n = 1215, p = 0.004, in a population-based cohort. These results identify PDI as a major target of post-streptococcal autoimmunity, and establish a new link between infection, autoimmunity, and metabolic disturbances.

  14. Monoclonal Antibodies Targeting the Alpha-Exosite of Botulinum Neurotoxin Serotype/A Inhibit Catalytic Activity.

    Directory of Open Access Journals (Sweden)

    Yongfeng Fan

    Full Text Available The paralytic disease botulism is caused by botulinum neurotoxins (BoNT, multi-domain proteins containing a zinc endopeptidase that cleaves the cognate SNARE protein, thereby blocking acetylcholine neurotransmitter release. Antitoxins currently used to treat botulism neutralize circulating BoNT but cannot enter, bind to or neutralize BoNT that has already entered the neuron. The light chain endopeptidase domain (LC of BoNT serotype A (BoNT/A was targeted for generation of monoclonal antibodies (mAbs that could reverse paralysis resulting from intoxication by BoNT/A. Single-chain variable fragment (scFv libraries from immunized humans and mice were displayed on the surface of yeast, and 19 BoNT/A LC-specific mAbs were isolated by using fluorescence-activated cell sorting (FACS. Affinities of the mAbs for BoNT/A LC ranged from a KD value of 9.0×10-11 M to 3.53×10-8 M (mean KD 5.38×10-9 M and median KD 1.53×10-9 M, as determined by flow cytometry analysis. Eleven mAbs inhibited BoNT/A LC catalytic activity with IC50 values ranging from 8.3 ~73×10-9 M. The fine epitopes of selected mAbs were also mapped by alanine-scanning mutagenesis, revealing that the inhibitory mAbs bound the α-exosite region remote from the BoNT/A LC catalytic center. The results provide mAbs that could prove useful for intracellular reversal of paralysis post-intoxication and further define epitopes that could be targeted by small molecule inhibitors.

  15. The strong in vivo anti-tumor effect of the UIC2 monoclonal antibody is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity.

    Directory of Open Access Journals (Sweden)

    Gábor Szalóki

    Full Text Available P-glycoprotein (Pgp extrudes a large variety of chemotherapeutic drugs from the cells, causing multidrug resistance (MDR. The UIC2 monoclonal antibody recognizes human Pgp and inhibits its drug transport activity. However, this inhibition is partial, since UIC2 binds only to 10-40% of cell surface Pgps, while the rest becomes accessible to this antibody only in the presence of certain substrates or modulators (e.g. cyclosporine A (CsA. The combined addition of UIC2 and 10 times lower concentrations of CsA than what is necessary for Pgp inhibition when the modulator is applied alone, decreased the EC50 of doxorubicin (DOX in KB-V1 (Pgp+ cells in vitro almost to the level of KB-3-1 (Pgp- cells. At the same time, UIC2 alone did not affect the EC50 value of DOX significantly. In xenotransplanted severe combined immunodeficient (SCID mice co-treated with DOX, UIC2 and CsA, the average weight of Pgp+ tumors was only ∼10% of the untreated control and in 52% of these animals we could not detect tumors at all, while DOX treatment alone did not decrease the weight of Pgp+ tumors. These data were confirmed by visualizing the tumors in vivo by positron emission tomography (PET based on their increased 18FDG accumulation. Unexpectedly, UIC2+DOX treatment also decreased the size of tumors compared to the DOX only treated animals, as opposed to the results of our in vitro cytotoxicity assays, suggesting that immunological factors are also involved in the antitumor effect of in vivo UIC2 treatment. Since UIC2 binding itself did not affect the viability of Pgp expressing cells, but it triggered in vitro cell killing by peripheral blood mononuclear cells (PBMCs, it is concluded that the impressive in vivo anti-tumor effect of the DOX-UIC2-CsA treatment is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity (ADCC.

  16. The strong in vivo anti-tumor effect of the UIC2 monoclonal antibody is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity.

    Science.gov (United States)

    Szalóki, Gábor; Krasznai, Zoárd T; Tóth, Ágnes; Vízkeleti, Laura; Szöllősi, Attila G; Trencsényi, György; Lajtos, Imre; Juhász, István; Krasznai, Zoltán; Márián, Teréz; Balázs, Margit; Szabó, Gábor; Goda, Katalin

    2014-01-01

    P-glycoprotein (Pgp) extrudes a large variety of chemotherapeutic drugs from the cells, causing multidrug resistance (MDR). The UIC2 monoclonal antibody recognizes human Pgp and inhibits its drug transport activity. However, this inhibition is partial, since UIC2 binds only to 10-40% of cell surface Pgps, while the rest becomes accessible to this antibody only in the presence of certain substrates or modulators (e.g. cyclosporine A (CsA)). The combined addition of UIC2 and 10 times lower concentrations of CsA than what is necessary for Pgp inhibition when the modulator is applied alone, decreased the EC50 of doxorubicin (DOX) in KB-V1 (Pgp+) cells in vitro almost to the level of KB-3-1 (Pgp-) cells. At the same time, UIC2 alone did not affect the EC50 value of DOX significantly. In xenotransplanted severe combined immunodeficient (SCID) mice co-treated with DOX, UIC2 and CsA, the average weight of Pgp+ tumors was only ∼10% of the untreated control and in 52% of these animals we could not detect tumors at all, while DOX treatment alone did not decrease the weight of Pgp+ tumors. These data were confirmed by visualizing the tumors in vivo by positron emission tomography (PET) based on their increased 18FDG accumulation. Unexpectedly, UIC2+DOX treatment also decreased the size of tumors compared to the DOX only treated animals, as opposed to the results of our in vitro cytotoxicity assays, suggesting that immunological factors are also involved in the antitumor effect of in vivo UIC2 treatment. Since UIC2 binding itself did not affect the viability of Pgp expressing cells, but it triggered in vitro cell killing by peripheral blood mononuclear cells (PBMCs), it is concluded that the impressive in vivo anti-tumor effect of the DOX-UIC2-CsA treatment is the combined result of Pgp inhibition and antibody dependent cell-mediated cytotoxicity (ADCC). PMID:25238617

  17. Inhibition of lipoxygenase activity in lentil protoplasts by monoclonal antibodies introduced into the cells via electroporation

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Maccarrone, M.; Veldink, G.A.

    1992-01-01

    The isolation of lentil protoplasts and the transfer of anti-lipoxygenase monoclonal antibodies into plant protoplasts by electroporation is reported. The dependence of the efficiency of monoclonal antibody incorporation on the field strength is shown as well. The transferred immunoglobulins retaine

  18. Local immunotherapy based on agonistic CD40 antibodies effectively inhibits experimental bladder cancer

    OpenAIRE

    Sandin, Linda C; Tötterman, Thomas H; Sara M. Mangsbo

    2014-01-01

    Local immunotherapy resurfaces in the field of cancer as a potential way to cure localized and metastatic disease with limited toxic effects. We have recently demonstrated that local administration of agonistic CD40 antibodies can cure localized as well as disseminated bladder neoplasms. This approach reduces the circulating concentrations of antibodies that would result from systemic delivery, hence resulting in limited toxicity.

  19. Epitope specificity and isotype of monoclonal anti-D antibodies dictate their ability to inhibit phagocytosis of opsonized platelets.

    Science.gov (United States)

    Kjaersgaard, Mimi; Aslam, Rukhsana; Kim, Michael; Speck, Edwin R; Freedman, John; Stewart, Donald I H; Wiersma, Erik J; Semple, John W

    2007-08-15

    Rh immune globulin (WinRho SDF; Cangene, Mississauga, ON, Canada) is an effective treatment for autoimmune thrombocytopenic purpura; however, maintaining a sustained supply for its use in autoimmune thrombocytopenic purpura and its primary indication, hemolytic disease of the newborn, makes the development of alternative reagents desirable. We compared Rh immune globulin and 6 human monoclonal anti-D antibodies (MoAnti-D) with differing isotypes and specificities for their ability to opsonize erythrocytes and inhibit platelet phagocytosis in an in vitro assay. Results demonstrated that opsonization of erythrocytes with Rh immune globulin significantly (P < .001) reduced phagocytosis of fluorescently labeled opsonized platelets in an Fc-dependent manner. Of the MoAnti-D that shared specificity but differed in isotype, only IgG3 antibodies could significantly (P < .001) inhibit platelet phagocytosis. In contrast, 2 MoAnti-D shared isotypes and differed in specificity; however, only one could significantly (P < .001) inhibit platelet phagocytosis. The results suggest that MoAnti-D epitope specificity and isotypes are critical requirements for optimal inhibition of opsonized platelet phagocytosis. PMID:17456719

  20. Inhibition of CD73 AMP hydrolysis by a therapeutic antibody with a dual, non-competitive mechanism of action.

    Science.gov (United States)

    Geoghegan, James C; Diedrich, Gundo; Lu, Xiaojun; Rosenthal, Kim; Sachsenmeier, Kris F; Wu, Herren; Dall'Acqua, William F; Damschroder, Melissa M

    2016-01-01

    CD73 (ecto-5'-nucleotidase) has recently been established as a promising immuno-oncology target. Given its role in activating purinergic signaling pathways to elicit immune suppression, antagonizing CD73 (i.e., releasing the brake) offers a complimentary pathway to inducing anti-tumor immune responses. Here, we describe the mechanistic activity of a new clinical therapeutic, MEDI9447, a human monoclonal antibody that non-competitively inhibits CD73 activity. Epitope mapping, structural, and mechanistic studies revealed that MEDI9447 antagonizes CD73 through dual mechanisms of inter-CD73 dimer crosslinking and/or steric blocking that prevent CD73 from adopting a catalytically active conformation. To our knowledge, this is the first report of an antibody that inhibits an enzyme's function through 2 distinct modes of action. These results provide a finely mapped epitope that can be targeted for selective, potent, and non-competitive inhibition of CD73, as well as establish a strategy for inhibiting enzymes that function in both membrane-bound and soluble states. PMID:26854859

  1. Neuraminidase inhibiting antibody responses in pigs differ between influenza A virus N2 lineages and by vaccine type.

    Science.gov (United States)

    Sandbulte, Matthew R; Gauger, Phillip C; Kitikoon, Pravina; Chen, Hongjun; Perez, Daniel R; Roth, James A; Vincent, Amy L

    2016-07-19

    The neuraminidase (NA) protein of influenza A viruses (IAV) has important functional roles in the viral replication cycle. Antibodies specific to NA can reduce viral replication and limit disease severity, but are not routinely measured. We analyzed NA inhibiting (NI) antibody titers in serum and respiratory specimens of pigs vaccinated with intramuscular whole-inactivated virus (WIV), intranasal live-attenuated influenza virus (LAIV), and intranasal wild type (WT) IAV. NI titers were also analyzed in sera from an investigation of piglet vaccination in the presence of passive maternally-derived antibodies. Test antigens contained genetically divergent swine-lineage NA genes homologous or heterologous to the vaccines with mismatched hemagglutinin genes (HA). Naïve piglets responded to WIV and LAIV vaccines and WT infection with strong homologous serum NI titers. Cross-reactivity to heterologous NAs depended on the degree of genetic divergence between the NA genes. Bronchoalveolar lavage specimens of LAIV and WT-immunized groups also had significant NI titers against the homologous antigen whereas the WIV group did not. Piglets of vaccinated sows received high levels of passive NI antibody, but their NI responses to homologous LAIV vaccination were impeded. These data demonstrate the utility of the enzyme-linked lectin assay for efficient NI antibody titration of serum as well as respiratory tract secretions. Swine IAV vaccines that induce robust NI responses are likely to provide broader protection against the diverse and rapidly evolving IAV strains that circulate in pig populations. Mucosal antibodies to NA may be one of the protective immune mechanisms induced by LAIV vaccines. PMID:27325350

  2. Monoclonal antibodies to the human insulin receptor block insulin binding and inhibit insulin action.

    OpenAIRE

    Roth, R A; Cassell, D J; Wong, K. Y.; Maddux, B A; Goldfine, I D

    1982-01-01

    Antibodies to the insulin receptor were prepared in BALB/c mice by immunization with IM-9 human lymphocytes, a cell type that has a large number of plasma membrane insulin receptors. The spleens of these mice were then removed, and their lymphocytes were fused to a mouse myeloma cell line, FO cells. After screening over 1,200 resulting hybrids, one stable hybrid was obtained that produced IgG1 antibodies directed towards the insulin receptor. This antibody blocked 125I-labeled insulin binding...

  3. Serum strain-specific or cross-reactive neuraminidase inhibiting antibodies against pandemic А/California/07/2009(H1N1) influenza in healthy volunteers

    OpenAIRE

    Desheva, Yulia A; Smolonogina, Tatiana A; Donina, Svetlana A; Rudenko, Larisa G

    2015-01-01

    Background Pre-existing antibodies to influenza virus neuraminidase may provide protection against infection influenza viruses containing novel hemagglutinin (HA). The aim of our study was to evaluate serum neuraminidase-inhibiting (NI) antibodies against А/California/07/2009(H1N1) [H1N1/2009pdm] and А/New Caledonia/20/1999(H1N1) [H1N1/1999] influenza viruses in relation with the age of participants and hemagglutination-inhibition (HI) antibody levels. Anti-H1N1/2009pdm neuraminidase and anti...

  4. Potent Inhibition of Human Immunodeficiency Virus Type 1 Replication by an Intracellular Anti-Rev Single-Chain Antibody

    Science.gov (United States)

    Duan, Lingxun; Bagasra, Omar; Laughlin, Mark A.; Oakes, Joseph W.; Pomerantz, Roger J.

    1994-05-01

    Human immunodeficiency virus type 1 (HIV-1) has a complex life cycle, which has made it a difficult target for conventional therapeutic modalities. A single-chain antibody moiety, directed against the HIV-1 regulatory protein Rev, which rescues unspliced viral RNA from the nucleus of infected cells, has now been developed. This anti-Rev single-chain construct (SFv) consists of both light and heavy chain variable regions of an anti-Rev monoclonal antibody, which, when expressed intracellularly within human cells, potently inhibits HIV-1 replication. This intracellular SFv molecule is demonstrated to specifically antagonize Rev function. Thus, intracellular SFv expression, against a retroviral regulatory protein, may be useful as a gene therapeutic approach to combat HIV-1 infections.

  5. Active glucose transport and proton pumping in tonoplast membrane of Zea mays L. coleoptiles are inhibited by anti-H+-ATPase antibodies

    International Nuclear Information System (INIS)

    A tonoplast enriched fraction was obtained from Zea mays L. coleoptiles by isopycnic centrifugation of microsomal membranes in a sucrose step gradient. At the 18/26% interface chloride-stimulated and nitrate-inhibited proton pumping activity coincided with a Mg2+-ATP dependent accumulation of 3-O-methyl-D-glucose (OMG) as determined by a membrane filtration technique using 14C-labeled substrate. OMG transport showed an apparently saturable component with a K/sub m/ of 110 micromolar, and was completely inhibited by 10 micromolar carbonyl cyanide m-chlorophenylhydrazone. Polyclonal antibodies against solubilized native tonoplast H+-ATPase and its 62 and 72 kilodalton subunits were assayed for their ability to inhibit proton pumping and OMG accumulation. Antibodies against both the native enzyme and the putative catalytic subunit strongly inhibited proton pumping and OMG transport whereas antibodies against the 62 kilodalton subunit had only a slight effect on both processes

  6. Intracytoplasmic stable expression of IgG1 antibody targeting NS3 helicase inhibits replication of highly efficient hepatitis C Virus 2a clone

    Directory of Open Access Journals (Sweden)

    Clementi Massimo

    2010-06-01

    Full Text Available Abstract Background Hepatitis C virus (HCV infection is a major public health problem with more than 170 million cases of chronic infections worldwide. There is no protective vaccine currently available for HCV, therefore the development of novel strategy to prevent chronic infection is important. We reported earlier that a recombinant human antibody clone blocks viral NS3 helicase activity and inhibits replication of HCV 1b virus. This study was performed further to explore the mechanism of action of this recombinant antibody and to determine whether or not this antibody inhibits replication and infectivity of a highly efficient JFH1 HCV 2a virus clone. Results The antiviral effect of intracellular expressed antibody against the HCV 2a virus strain was examined using a full-length green fluorescence protein (GFP labeled infectious cell culture system. For this purpose, a Huh-7.5 cell line stably expressing the NS3 helicase gene specific IgG1 antibody was prepared. Replication of full-length HCV-GFP chimera RNA and negative-strand RNA was strongly inhibited in Huh-7.5 cells stably expressing NS3 antibody but not in the cells expressing an unrelated control antibody. Huh-7.5 cells stably expressing NS3 helicase antibody effectively suppressed infectious virus production after natural infection and the level of HCV in the cell free supernatant remained undetectable after first passage. In contrast, Huh-7.5 cells stably expressing an control antibody against influenza virus had no effect on virus production and high-levels of infectious HCV were detected in culture supernatants over four rounds of infectivity assay. A recombinant adenovirus based expression system was used to demonstrate that Huh-7.5 replicon cell line expressing the intracellular antibody strongly inhibited the replication of HCV-GFP RNA. Conclusion Recombinant human anti-HCV NS3 antibody clone inhibits replication of HCV 2a virus and infectious virus production. Intracellular

  7. Antibody titers against swine influenza subtypes determined by the hemagglutination inhibition test are highly dependent on the strain

    DEFF Research Database (Denmark)

    Trebbien, Ramona; Nielsen, Jens; Bøtner, Anette;

    diagnostic and epidemiological point of view it is crucial to clarify whether the immunological response to one subtype protects against infection with the other subtype. The hemagglutination inhibition test (HI-test) has been used widely to determine the presence of antibodies in serum against influenza......In Denmark there are three circulating strains of swine influenza H1N1, H1N2 and H3N2. The H1N2 is different from the H1N2 subtypes circulating in other European countries. The Danish subtype is a reassortment between the two Danish circulating swine influenza subtypes H1N1 and H3N2. From a...... viruses. In the present study the HI-test was used to determine antibody response from experimental infected pigs. The aim of the study was to evaluate the antibody response against the new Danish influenza subtype H1N2 (H1N2dk) and to examine the level of crossprotection/reaction between the two...

  8. Inhibition of Staphylococcus epidermidis biofilm formation by rabbit polyclonal antibodies against the SesC protein.

    NARCIS (Netherlands)

    Shahrooei, M.; Hira, V.; Stijlemans, B.; Merckx, R.; Hermans, P.W.M.; Eldere, J. van

    2009-01-01

    Several well-studied proteins with defined roles in Staphylococcus epidermidis biofilm formation are LPXTG motif-containing proteins. Here, we investigate the possible use of the LPXTG motif-containing protein SesC (S. epidermidis surface protein C; accession no. NP_765787) as a target for antibodie

  9. Anti-ADAMTS5 monoclonal antibodies: implications for aggrecanase inhibition in osteoarthritis.

    Science.gov (United States)

    Apte, Suneel S

    2016-01-01

    The extracellular matrix of articular cartilage is structurally specialized for efficient absorption of mechanical impact. In particular, giant aggregates of the large chondroitin sulfate proteoglycan, aggrecan, with the glycosaminoglycan, hyaluronan, allow cartilage to resist compressive load. Proteolysis of aggrecan by members of the proteinase family ADAMTS (A disintegrin-like and metalloproteinase domain with thrombospondin type 1 motif), was identified as an early step in the inexorable destruction of cartilage in osteoarthritis (OA). Of the investigated proteinases, ADAMTS5 has emerged as a principal mediator of aggrecan loss in OA, convincingly so in mouse models, and with high probability in humans. ADAMTS5 has a bipartite organization, comprising a proteinase domain and an ancillary domain containing exosites for interaction with aggrecan and other substrates. In a recent issue of this journal, Santamaria et al. characterized anti-ADAMTS5 monoclonal antibodies isolated from a phage display library. By blocking the catalytic site of the ADAMTS5 immunogen with a synthetic inhibitor, the authors of the paper biased selection of antibodies to the ancillary domain. This work, together with other antibodies targeting ADAMTS5, offers diverse, high-affinity and, as far as can be determined, selective aggrecanase inhibitors. Mapping of their epitopes provided novel insights into ADAMTS5 interactions with aggrecan. These monoclonal antibodies deserve continued investigation for potential arthritis therapy, although their successful use will require a comprehensive understanding of the physiological roles of ADAMTS5, and its regulation, intrinsic properties and intermolecular interactions. PMID:26657033

  10. Antibody-dependent enhancement of dengue virus infection is inhibited by SA-17, a doxorubicin derivative

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa; Jarupathirun, Patsaporn; Kaptein, Suzanne; Neyts, Johan; Smit, Jolanda

    2013-01-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus (DENV)-induced disease during a heterologous re-infection. Despite ADE's clinical impact, only a few antiviral compounds have been assessed for their anti-ADE activity. We reported earlier tha

  11. Inhibition of human immunodeficiency virus (HIV) infection in vitro by anticarbohydrate monoclonal antibodies

    DEFF Research Database (Denmark)

    Hansen, J E; Clausen, H; Nielsen, C;

    1990-01-01

    - and O-linked carbohydrate epitopes (LeY, A1, and sialyl-Tn) were able to block infection by cell-free virus as well as inhibit syncytium formation. Inhibition of virus infectivity was independent of virus strain (HTLVIIIB or patient isolate SSI-002), the cell line used for virus propagation (H9 or MT4...

  12. Fluorescence Adherence Inhibition Assay: A Novel Functional Assessment of Blocking Virus Attachment by Vaccine-Induced Antibodies.

    Science.gov (United States)

    Asati, Atul; Kachurina, Olga; Karol, Alex; Dhir, Vipra; Nguyen, Michael; Parkhill, Robert; Kouiavskaia, Diana; Chumakov, Konstantin; Warren, William; Kachurin, Anatoly

    2016-01-01

    Neutralizing antibodies induced by vaccination or natural infection play a critically important role in protection against the viral diseases. In general, neutralization of the viral infection occurs via two major pathways: pre- and post-attachment modes, the first being the most important for such infections as influenza and polio, the latter being significant for filoviruses. Neutralizing capacity of antibodies is typically evaluated by virus neutralization assays that assess reduction of viral infectivity to the target cells in the presence of functional antibodies. Plaque reduction neutralization test, microneutralization and immunofluorescent assays are often used as gold standard virus neutralization assays. However, these methods are associated with several important prerequisites such as use of live virus requiring safety precautions, tedious evaluation procedure and long assessment time. Hence, there is a need for a robust, inexpensive high throughput functional assay that can be performed rapidly using inactivated virus, without extensive safety precautions. Herein, we report a novel high throughput Fluorescence Adherence Inhibition assay (fADI) using inactivated virus labeled with fluorescent secondary antibodies virus and Vero cells or erythrocytes as targets. It requires only few hours to assess pre-attachment neutralizing capacity of donor sera. fADI assay was tested successfully on donors immunized with polio, yellow fever and influenza vaccines. To further simplify and improve the throughput of the assay, we have developed a mathematical approach for calculating the 50% titers from a single sample dilution, without the need to analyze multi-point titration curves. Assessment of pre- and post-vaccination human sera from subjects immunized with IPOL®, YF-VAX® and 2013-2014 Fluzone® vaccines demonstrated high efficiency of the assay. The results correlated very well with microneutralization assay performed independently by the FDA Center of

  13. Anti-Sclerostin antibody inhibits internalization of Sclerostin and Sclerostin-mediated antagonism of Wnt/LRP6 signaling.

    Directory of Open Access Journals (Sweden)

    Maarten van Dinther

    Full Text Available Sclerosteosis is a rare high bone mass disease that is caused by inactivating mutations in the SOST gene. Its gene product, Sclerostin, is a key negative regulator of bone formation and might therefore serve as a target for the anabolic treatment of osteoporosis. The exact molecular mechanism by which Sclerostin exerts its antagonistic effects on Wnt signaling in bone forming osteoblasts remains unclear. Here we show that Wnt3a-induced transcriptional responses and induction of alkaline phosphatase activity, an early marker of osteoblast differentiation, require the Wnt co-receptors LRP5 and LRP6. Unlike Dickkopf1 (DKK1, Sclerostin does not inhibit Wnt-3a-induced phosphorylation of LRP5 at serine 1503 or LRP6 at serine 1490. Affinity labeling of cell surface proteins with [(125I]Sclerostin identified LRP6 as the main specific Sclerostin receptor in multiple mesenchymal cell lines. When cells were challenged with Sclerostin fused to recombinant green fluorescent protein (GFP this was internalized, likely via a Clathrin-dependent process, and subsequently degraded in a temperature and proteasome-dependent manner. Ectopic expression of LRP6 greatly enhanced binding and cellular uptake of Sclerostin-GFP, which was reduced by the addition of an excess of non-GFP-fused Sclerostin. Finally, an anti-Sclerostin antibody inhibited the internalization of Sclerostin-GFP and binding of Sclerostin to LRP6. Moreover, this antibody attenuated the antagonistic activity of Sclerostin on canonical Wnt-induced responses.

  14. Inhibition of Spontaneous Breast Cancer Metastasis by Anti—Thomsen-Friedenreich Antigen Monoclonal Antibody JAA-F11

    Directory of Open Access Journals (Sweden)

    Jamie Heimburg

    2006-11-01

    Full Text Available Thomsen-Friedenreich antigen (TF-Ag is expressed in many carcinomas, including those of the breast, colon, bladder, prostate. TF-Ag is important in adhesion and metastasis and as a potential immunotherapy target. We hypothesized that passive transfer of JAAF11, an anti -TF-Ag monoclonal antibody, may create a survival advantage for patients with TIF-Ag -expressing tumors by cytotoxicity, blocking of tumor cell adhesion, inhibition of metastasis. This was tested using in vitro models of tumor cell growth; cytotoxicity assays; in vitro, ex vivo, in vivo models of cancer metastasis; and, finally, in vivo effects in mice with metastatic breast cancer. Unlike some anti-TF-Ag antibodies, JAA-F11 did not enhance breast carcinoma cell growth. JAA-F11 did not induce the killing of 4T1 tumor cells through complement-dependent cytotoxicity or apoptotic mechanisms. However, JAA-F11 blocked the stages of metastasis that involve the adhesion of human breast carcinoma cells to human endothelial cells (human umbilical vein endothelial cells and human bone marrow endothelial cells 60 in in vitro static adhesion models, in a perfused ex vivo model, in murine lung vasculature in an in vivo metastatic deposit formation assay. JAA-F11 significantly extended the median survival time of animals bearing metastatic 4T1 breast tumors and caused a > 50% inhibition of lung metastasis.

  15. Anti-epidermal growth factor receptor monoclonal antibody cetuximab inhibits EGFR/HER-2 heterodimerization and activation.

    Science.gov (United States)

    Patel, Dipa; Bassi, Rajiv; Hooper, Andrea; Prewett, Marie; Hicklin, Daniel J; Kang, Xiaoqiang

    2009-01-01

    Human carcinomas frequently express one or more members of the epidermal growth factor receptor family. Two family members, epidermal growth factor receptor (EGFR) and c-erbB2/neu (HER2), homodimerize or heterodimerize upon activation with ligand and trigger potent mechanisms of cellular proliferation, differentiation and migration. In this study, we examined the effect of the anti-EGFR monoclonal antibody Erbitux (cetuximab) on human tumor cells expressing both EGFR and HER2. Investigation of the effect of cetuximab on the activation of EGFR-EGFR, EGFR-HER2 and HER2-HER2 homodimers and heterodimers was conducted using the NCI-N87 human gastric carcinoma cell line. Treatment of NCI-N87 cells with cetuximab completely inhibited formation of EGFR-EGFR homodimers and EGFR-HER2 heterodimers. Activation of HER2-HER2 homodimers was not appreciably stimulated by exogenous ligand and was not inhibited by cetuximab treatment. Furthermore, cetuximab inhibited EGF-induced EGFR and HER2 phosphorylation in CAL27, NCI-H226 and NCI-N87 cells. The activation of downstream signaling molecules such as AKT, MAPK and STAT-3 were also inhibited by cetuximab in these cells. To examine the effect of cetuximab on the growth of tumors in vivo, athymic mice bearing established NCI-N87 or CAL27 xenografts were treated with cetuximab (1 mg, i.p., q3d). The growth of NCI-N87 and CAL27 tumors was significantly inhibited with cetuximab therapy compared to the control groups (p<0.0001 in both cases). In the CAL27 xenograft model, tumor growth inhibition by cetuximab treatment was similar to that by cetuximab and trastuzumab combination treatment. Immunohistological analysis of cetuximab-treated tumors showed a decrease in EGFR-HER2 signaling and reduced tumor cell proliferation. These results suggest that cetuximab may be useful in the treatment of carcinomas co-expressing EGFR and HER2. PMID:19082474

  16. Mode of inhibition of HIV-1 Integrase by a C-terminal domain-specific monoclonal antibody*

    Directory of Open Access Journals (Sweden)

    Merkel George

    2006-06-01

    Full Text Available Abstract Background To further our understanding of the structure and function of HIV-1 integrase (IN we developed and characterized a library of monoclonal antibodies (mAbs directed against this protein. One of these antibodies, mAb33, which is specific for the C-terminal domain, was found to inhibit HIV-1 IN processing activity in vitro; a corresponding Fv fragment was able to inhibit HIV-1 integration in vivo. Our subsequent studies, using heteronuclear nuclear magnetic resonance spectroscopy, identified six solvent accessible residues on the surface of the C-terminal domain that were immobilized upon binding of the antibody, which were proposed to comprise the epitope. Here we test this hypothesis by measuring the affinity of mAb33 to HIV-1 proteins that contain Ala substitutions in each of these positions. To gain additional insight into the mode of inhibition we also measured the DNA binding capacity and enzymatic activities of the Ala substituted proteins. Results We found that Ala substitution of any one of five of the putative epitope residues, F223, R224, Y226, I267, and I268, caused a decrease in the affinity of the mAb33 for HIV-1 IN, confirming the prediction from NMR data. Although IN derivatives with Ala substitutions in or near the mAb33 epitope exhibited decreased enzymatic activity, none of the epitope substitutions compromised DNA binding to full length HIV-1 IN, as measured by surface plasmon resonance spectroscopy. Two of these derivatives, IN (I276A and IN (I267A/I268A, exhibited both increased DNA binding affinity and uncharacteristic dissociation kinetics; these proteins also exhibited non-specific nuclease activity. Results from these investigations are discussed in the context of current models for how the C-terminal domain interacts with substrate DNA. Conclusion It is unlikely that inhibition of HIV-1 IN activity by mAb33 is caused by direct interaction with residues that are essential for substrate binding. Rather

  17. Bevacizumab, an anti-vascular endothelial growth factor antibody, inhibits osteoarthritis

    OpenAIRE

    Nagai, Toshihiro; Sato, Masato; Kobayashi, Miyuki; Yokoyama, Munetaka; Tani, Yoshiki; Mochida, Joji

    2014-01-01

    Introduction Angiogenesis is an important factor in the development of osteoarthritis (OA). We investigated the efficacy of bevacizumab, an antibody against vascular endothelial growth factor and an inhibitor of angiogenesis, in the treatment of OA using a rabbit model of anterior cruciate ligament transection. Methods First, we evaluated the response of gene expression and histology of the normal joint to bevacizumab treatment. Next, in a rabbit model of OA induced by anterior cruciate ligam...

  18. Differential inhibition of lipopolysaccharide-induced phenomena by anti-tumor necrosis factor alpha antibody.

    OpenAIRE

    Vogel, S N; Havell, E A

    1990-01-01

    Tumor necrosis factor alpha (TNF alpha) has been implicated as a major mediator of lipopolysaccharide (LPS)-induced phenomena. Administration to mice of a polyclonal, monospecific antibody prepared against recombinant murine TNF alpha abolished detection of LPS-induced TNF alpha activity and significantly reduced levels of LPS-induced colony-stimulating factor but failed to reduce the production of LPS-induced interferon, corticosterone, or LPS-induced hypoglycemia.

  19. Antibody-dependent cellular inhibition is associated with reduced risk against febrile malaria in a longitudinal cohort study involving Ghanaian children

    DEFF Research Database (Denmark)

    Tiendrebeogo, Regis W; Adu, Bright; Singh, Susheel K; Dziegiel, Morten H; Nébié, Issa; Sirima, Sodiomon B; Christiansen, Michael; Dodoo, Daniel; Theisen, Michael

    2015-01-01

    The antibody-dependent respiratory burst and opsonic phagocytosis assays have been associated with protection against malaria; however, other mechanisms may also be involved. The antibody-dependent cellular inhibition (ADCI) assay is yet to be correlated with protection in longitudinal cohort stu...... ADCI assay as a correlate of protection to guide malaria vaccine studies.......The antibody-dependent respiratory burst and opsonic phagocytosis assays have been associated with protection against malaria; however, other mechanisms may also be involved. The antibody-dependent cellular inhibition (ADCI) assay is yet to be correlated with protection in longitudinal cohort...... studies (LCS). We investigated the relationship between ADCI activity of immunoglobulin G before malaria season and risk of malaria in a LCS involving Ghanaian children. High ADCI activity was significantly associated with reduced risk against malaria. Findings here suggest a potential usefulness of the...

  20. The relationship between single radial hemolysis, hemagglutination inhibition, and virus neutralization assays used to detect antibodies specific for equine influenza viruses.

    Science.gov (United States)

    Morley, P S; Hanson, L K; Bogdan, J R; Townsend, H G; Appleton, J A; Haines, D M

    1995-06-01

    Antibodies specific for equine influenza viruses are usually quantified using single radial hemolysis (SRH), hemagglutination inhibition (HI) or virus neutralization (VN). Neutralizing antibodies are thought to provide optimum protection to challenged animals. The purpose of this study was to determine the extent to which SRH and HI assays detect antibodies which neutralize equine influenza viruses. Acute and convalescent sera from 41 horses were analyzed using VN, SRH, and HI assays. These horses were present in a population of Thoroughbred racehorses during an epidemic of upper respiratory tract disease associated with influenza A/equine/Saskatoon/1/91 (H3N8), infections. Concentrations of antibodies binding to influenza A/equine/Kentucky/1/81 (H3N8), A/equine/Miami/1/63 (H3N8), and A/equine/Prague/1/56 (H7N7) were determined. Results of the VN assay were compared with results from the SRH and HI assays for acute antibody levels, changes in antibody concentrations between acute and convalescent sampling, and the occurrence of seroconversion. The correlation between assays for pre-exposure antibody levels ranged from 88% to 96%. The correlation between assays for change in antibody concentration ranged from 83% to 90% for the H3N8 viruses. This study shows that antibody concentrations specific for equine influenza virus, measured using SRH and HI assays, are highly correlated with concentrations detected using a VN assay. PMID:7653031

  1. Immunisation with recombinant PfEMP1 domains elicits functional rosette-inhibiting and phagocytosis-inducing antibodies to Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Ashfaq Ghumra

    Full Text Available BACKGROUND: Rosetting is a Plasmodium falciparum virulence factor implicated in the pathogenesis of life-threatening malaria. Rosetting occurs when parasite-derived P. falciparum Erythrocyte Membrane Protein One (PfEMP1 on the surface of infected erythrocytes binds to human receptors on uninfected erythrocytes. PfEMP1 is a possible target for a vaccine to induce antibodies to inhibit rosetting and prevent severe malaria. METHODOLOGY/FINDINGS: We examined the vaccine potential of the six extracellular domains of a rosette-mediating PfEMP1 variant (ITvar9/R29var1 from the R29 parasite strain by immunizing rabbits with recombinant proteins expressed in E. coli. Antibodies raised to each domain were tested for surface fluorescence with live infected erythrocytes, rosette inhibition and phagocytosis-induction. Antibodies to all PfEMP1 domains recognized the surface of live infected erythrocytes down to low concentrations (0.02-1.56 µg/ml of total IgG. Antibodies to all PfEMP1 domains except for the second Duffy-Binding-Like region inhibited rosetting (50% inhibitory concentration 0.04-4 µg/ml and were able to opsonize and induce phagocytosis of infected erythrocytes at low concentrations (1.56-6.25 µg/ml. Antibodies to the N-terminal region (NTS-DBL1α were the most effective in all assays. All antibodies were specific for the R29 parasite strain, and showed no functional activity against five other rosetting strains. CONCLUSIONS/SIGNIFICANCE: These results are encouraging for vaccine development as they show that potent antibodies can be generated to recombinant PfEMP1 domains that will inhibit rosetting and induce phagocytosis of infected erythrocytes. However, further work is needed on rosetting mechanisms and cross-reactivity in field isolates to define a set of PfEMP1 variants that could induce functional antibodies against a broad range of P. falciparum rosetting parasites.

  2. A novel monoclonal anti-CD81 antibody produced by genetic immunization efficiently inhibits Hepatitis C virus cell-cell transmission.

    Directory of Open Access Journals (Sweden)

    Isabel Fofana

    Full Text Available BACKGROUND AND AIMS: Hepatitis C virus (HCV infection is a challenge to prevent and treat because of the rapid development of drug resistance and escape. Viral entry is required for initiation, spread, and maintenance of infection, making it an attractive target for antiviral strategies. METHODS: Using genetic immunization, we produced four monoclonal antibodies (mAbs against the HCV host entry factor CD81. The effects of antibodies on inhibition of HCV infection and dissemination were analyzed in HCV permissive human liver cell lines. RESULTS: The anti-CD81 mAbs efficiently inhibited infection by HCV of different genotypes as well as a HCV escape variant selected during liver transplantation and re-infecting the liver graft. Kinetic studies indicated that anti-CD81 mAbs target a post-binding step during HCV entry. In addition to inhibiting cell-free HCV infection, one antibody was also able to block neutralizing antibody-resistant HCV cell-cell transmission and viral dissemination without displaying any detectable toxicity. CONCLUSION: A novel anti-CD81 mAb generated by genetic immunization efficiently blocks HCV spread and dissemination. This antibody will be useful to further unravel the role of virus-host interactions during HCV entry and cell-cell transmission. Furthermore, this antibody may be of interest for the development of antivirals for prevention and treatment of HCV infection.

  3. Anti-caries DNA vaccine-induced secretory immunoglobulin A antibodies inhibit formation of Streptococcus mutans biofilms in vitro

    Institute of Scientific and Technical Information of China (English)

    Li HUANG; Qing-an XU; Chang LIU; Ming-wen FAN; Yu-hong LI

    2013-01-01

    Aim: To investigate the effects of anti-caries DNA vaccine-induced salivary secretory immunoglobulin A (S-IgA) antibodies on Streptococcus mutans (S.mutans) adherence and biofilms formation in vitro.Methods: Adult female Wistar rats were intranasally immunized with the anti-caries DNA vaccine pGJA-P/VAX.Their saliva samples were collected at different times after the immunization,and S-IgA antibody level in the saliva and its inhibition on S.mutans adherence were examined.The effects of S-IgA in the saliva with the strongest inhibitory effects were examined at 3 different stages,ie acquired pellicles,biofilm formation and production of mature biofilms.The number of viable bacteria and depth of the biofilm at 16 h in each stage were determined using counting colony forming units and using a confocal laser scanning microscopy (CLSM).The participation of S-IgA in acquired pellicles and its aggregation with S.mutans were also observed under CLSM.Results: The S-lgA titer in saliva reached its peak and exhibited the strongest inhibition on S.mutans adhesion at 10 weeks after the immunization.The colonies and depth of the biofilm in the saliva-pretreated group were 41.79% and 41.02%,respectively,less than the control group.The colonies and depth of the biofilm in the co-culture group were 27.4% and 22.81% less than the control group.The assembly of S.mutans and S-IgA was observed under CLSM after co-cultivation.In the mature-stage biofilm,no differences were observed between the different groups.Conclusion: These results demonstrate that the anti-caries DNA vaccine induces the production of specific S-IgA antibodies that may prevent dental caries by inhibiting the initial adherence of S.mutans onto tooth surfaces,thereby reducing the accumulation of S.mutans on the acquired pellicles.

  4. Neutralizing antibodies induced by recombinant virus-like particles of enterovirus 71 genotype C4 inhibit infection at pre- and post-attachment steps.

    Directory of Open Access Journals (Sweden)

    Zhiqiang Ku

    Full Text Available BACKGROUND: Enterovirus 71 (EV71 is a major causative agent of hand, foot and mouth disease, which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Antibodies elicited by experimental EV71 vaccines could neutralize infection in vitro and passively protect animal models from lethal challenge, indicating that neutralizing antibodies play an essential role in protection. However, how neutralizing antibodies inhibit infection in vitro remains unclear. METHODS/FINDINGS: In the present study, we explored the mechanisms of neutralization by antibodies against EV71 virus-like particles (VLPs. Recombinant VLPs of EV71 genotype C4 were produced in insect cells using baculovirus vectors. Immunization with the VLPs elicited a high-titer, EV71-specific antibody response in mice. Anti-VLP mouse sera potently neutralized EV71 infection in vitro. The neutralizing antibodies in the anti-VLP mouse sera were found to target mainly an extremely conserved epitope (FGEHKQEKDLEYGAC located at the GH loop of the VP1 protein. The neutralizing anti-VLP antisera were able to inhibit virus binding to target cells efficiently. In addition, post-attachment treatment of virus-bound cells with the anti-VLP antisera also neutralized virus infection, although the antibody concentration required was higher than that of the pre-attachment treatment. CONCLUSIONS: Collectively, our findings represent a valuable addition to the understanding of mechanisms of EV71 neutralization and have strong implications for EV71 vaccine development.

  5. Structural bases of coronavirus attachment to host aminopeptidase N and its inhibition by neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Juan Reguera

    Full Text Available The coronaviruses (CoVs are enveloped viruses of animals and humans associated mostly with enteric and respiratory diseases, such as the severe acute respiratory syndrome and 10-20% of all common colds. A subset of CoVs uses the cell surface aminopeptidase N (APN, a membrane-bound metalloprotease, as a cell entry receptor. In these viruses, the envelope spike glycoprotein (S mediates the attachment of the virus particles to APN and subsequent cell entry, which can be blocked by neutralizing antibodies. Here we describe the crystal structures of the receptor-binding domains (RBDs of two closely related CoV strains, transmissible gastroenteritis virus (TGEV and porcine respiratory CoV (PRCV, in complex with their receptor, porcine APN (pAPN, or with a neutralizing antibody. The data provide detailed information on the architecture of the dimeric pAPN ectodomain and its interaction with the CoV S. We show that a protruding receptor-binding edge in the S determines virus-binding specificity for recessed glycan-containing surfaces in the membrane-distal region of the pAPN ectodomain. Comparison of the RBDs of TGEV and PRCV to those of other related CoVs, suggests that the conformation of the S receptor-binding region determines cell entry receptor specificity. Moreover, the receptor-binding edge is a major antigenic determinant in the TGEV envelope S that is targeted by neutralizing antibodies. Our results provide a compelling view on CoV cell entry and immune neutralization, and may aid the design of antivirals or CoV vaccines. APN is also considered a target for cancer therapy and its structure, reported here, could facilitate the development of anti-cancer drugs.

  6. Inhibition of glucosyltransferase activities of Streptococcus mutans by a monoclonal antibody to a subsequence peptide.

    OpenAIRE

    Chia, J S; Lin, R.H.; S.W. Lin; Chen, J.Y.; C. S. Yang

    1993-01-01

    Preliminary analysis indicated that a 19-amino-acid peptide sequence (435 to 453 of GtfC) within a highly conserved region of the glucosyltransferases of the cariogenic streptococci might be functionally important (J.-S. Chia, S.-W. Lin, T.-Y. Hsu, J.-Y. Chen, H.-W. Kwan, and C.-S. Yang, Infect. Immun. 61:1563-1566, 1993). To obtain antipeptide monoclonal antibodies (MAbs), the 19-amino-acid peptide was conjugated to bovine serum albumin and used as an antigen in BALB/c mice. Six immunoglobul...

  7. Anti-GAPDHS antibodies can inhibit in vitro sperm-oocyte binding

    Czech Academy of Sciences Publication Activity Database

    Dorosh, Andriy; Margaryan, Hasmik; Čapková, Jana; Maňásková-Postlerová, Pavla; Pěknicová, Jana

    Madison: Society for the Study of Reproduction, 2015. s. 212. [48th Annual Meeting of the Society for the Study of reproduction. 18.06.2015-22.06.2015, San Juan] R&D Projects: GA ČR(CZ) GAP503/12/1834; GA MŠk(CZ) ED1.1.00/02.0109 Institutional research plan: CEZ:AV0Z50520701 Institutional support: RVO:86652036 Keywords : GAPDHS * antibodies * sperm-oocyte binding * acrosin * zona pellucida Subject RIV: CE - Biochemistry

  8. High-Throughput Testing of Antibody-Dependent Binding Inhibition of Placental Malaria Parasites

    DEFF Research Database (Denmark)

    Nielsen, Morten A; Salanti, Ali

    2015-01-01

    different human receptors through Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) on the surface of the infected cell. As the var genes encoding the large PfEMP1 antigens are extensively polymorphic, vaccine development strategies are focused on targeting the functional binding epitopes. This...... involves identification of recombinant fragments of PfEMP1s that induce antibodies, which hinder the adhesion of the IE to a given receptor or tissue. Different assays to measure the blocking of adhesion have been described in the literature, each with different advantages. This chapter describes a high...

  9. Broadly Neutralizing Alphavirus Antibodies Bind an Epitope on E2 and Inhibit Entry and Egress.

    Science.gov (United States)

    Fox, Julie M; Long, Feng; Edeling, Melissa A; Lin, Hueylie; van Duijl-Richter, Mareike K S; Fong, Rachel H; Kahle, Kristen M; Smit, Jolanda M; Jin, Jing; Simmons, Graham; Doranz, Benjamin J; Crowe, James E; Fremont, Daved H; Rossmann, Michael G; Diamond, Michael S

    2015-11-19

    We screened a panel of mouse and human monoclonal antibodies (MAbs) against chikungunya virus and identified several with inhibitory activity against multiple alphaviruses. Passive transfer of broadly neutralizing MAbs protected mice against infection by chikungunya, Mayaro, and O'nyong'nyong alphaviruses. Using alanine-scanning mutagenesis, loss-of-function recombinant proteins and viruses, and multiple functional assays, we determined that broadly neutralizing MAbs block multiple steps in the viral lifecycle, including entry and egress, and bind to a conserved epitope on the B domain of the E2 glycoprotein. A 16 Å resolution cryo-electron microscopy structure of a Fab fragment bound to CHIKV E2 B domain provided an explanation for its neutralizing activity. Binding to the B domain was associated with repositioning of the A domain of E2 that enabled cross-linking of neighboring spikes. Our results suggest that B domain antigenic determinants could be targeted for vaccine or antibody therapeutic development against multiple alphaviruses of global concern. PMID:26553503

  10. Antibody to E1 peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to HepG2 cells in vitro

    Science.gov (United States)

    EL-Awady, Mostafa K; Tabll, Ashraf A; Atef, Khaled; Yousef, Samar S; Omran, Moataza H; El-Abd, Yasmin; Bader-Eldin, Noha G; Salem, Ahmad M; Zohny, Samir F; El-Garf, Wael T

    2006-01-01

    AIM: To analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus (HCV). Specific polyclonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of HCV and was shown to be highly conserved among HCV published genotypes. METHODS: Hyper-immune HCV E1 antibodies were incubated over night at 4 °C with serum samples positive for HCV RNA, with viral loads ranging from 615 to 3.2 million IU/ mL. Treated sera were incubated with HepG2 cells for 90 min. Blocking of viral binding and entry into cells by anti E1 antibody were tested by means of RT-PCR and flow cytometry. RESULTS: Direct immunostaining using FITC conjugated E1 antibody followed by Flow cytometric analysis showed reduced mean fluorescence intensity in samples pre-incubated with E1 antibody compared with untreated samples. Furthermore, 13 out of 18 positive sera (72%) showed complete inhibition of infectivity as detected by RT-PCR. CONCLUSION: In house produced E1 antibody, blocks binding and entry of HCV virion infection to target cells suggesting the involvement of this epitope in virus binding and entry. Isolation of these antibodies that block virus attachment to human cells are useful as therapeutic reagents. PMID:16688798

  11. Antibody-Mediated Inhibition of TNFR1 Attenuates Disease in a Mouse Model of Multiple Sclerosis

    OpenAIRE

    Williams, Sarah K.; Olaf Maier; Roman Fischer; Richard Fairless; Sonja Hochmeister; Aleksandar Stojic; Lara Pick; Doreen Haar; Sylvia Musiol; Maria K Storch; Klaus Pfizenmaier; Ricarda Diem

    2014-01-01

    Tumour necrosis factor (TNF) is a proinflammatory cytokine that is known to regulate inflammation in a number of autoimmune diseases, including multiple sclerosis (MS). Although targeting of TNF in models of MS has been successful, the pathological role of TNF in MS remains unclear due to clinical trials where the non-selective inhibition of TNF resulted in exacerbated disease. Subsequent experiments have indicated that this may have resulted from the divergent effects of the two TNF receptor...

  12. A therapeutic anti-CD4 monoclonal antibody inhibits T cell receptor signal transduction in mouse autoimmune cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao-hui; LIAO Yu-hua; YUAN Jing; ZHANG Li; WANG Min; ZHANG Jing-hui; LIU Zhong-ping; DONG Ji-hua

    2007-01-01

    Background T cell immune abnormalities in patients with dilated cardiomyopathy (DCM) has been intensively studied over the past 10 years. Our previous study has suggested that immunization of mice with the peptides derived from human adenine nucleotide translocator (ANT) result in the production of autoantibodies against the ANT and histopathological changes similar to those in human DCM. The ANT peptides can induce autoimmune cardiomyopathy like DCM in Balb/c mice. In this study we aimed to focus on the molecular mechanism of T cells in the autoimmune cardiomyopathy mouse model by detecting the expression of the two T cell signaling molecules.Methods The ANT peptides were used to cause autoimmune cardiomyopathy in Balb/c mice. Anti-L3T4 or rat anti-mouse IgG was administered to the mice (n=6 in each group) simultaneously immunized with ANT. ELISA analysis was used to detect autoantibodies against the ANT peptides and the percentages of interferon-Y and interleukin-4 producing cells among splenic CD4+ lymphocytes was determined by using flow cytometry analysis. The expression of CD45 in spleen T cells was determined by immunohistochemistry and the mRNAs of T cell signaling molecules were detected by real-time PCR.Results Treatment of ANT immunized Balb/c mice with anti-CD4 mAb caused a reduction in the gene expression of P56lck and Zap-70 and a lower level of CD45 expression by spleen T cells. Aiso, a reverse of the Th1/Th2 ratio that results in the reduced production of antibodies against ANT was found in the anti-CD4 monoclonal antibodies (mAb)group. Whereas irrelevant antibody (rat anti-mouse IgG) did not suppress T cell signaling molecules nor inhibit CD45 expression, and control-antibody mice did not show any significant differences compared with the DCM group.Conclusion The results show that anti-CD4 mAb is a powerful inhibitor of the early initiating events of T cell receptor(TCR) signal transduction in mouse autoimmune dilated cardiomyopathy.

  13. HIV reverse transcriptase inhibiting antibodies detected by a new technique: relation to p24 and gp41 antibodies, HIV antigenemia and clinical variables.

    Science.gov (United States)

    Neumüller, M; Karlsson, A; Lennerstrand, J; Källander, C F; Holmberg, V; Långström-Persson, U; Thorstensson, R; Sandström, E; Gronowitz, J S

    1991-05-01

    A new assay for HIV reverse transcriptase activity inhibiting antibodies (RTI-ab) was used for the analysis of a large collection of sera sampled before and after confirmation of HIV infection. In this assay HIV-RT was preincubated with diluted serum, after which residual RT activity was determined by a technique using a template coupled to macrobeads and 125I-lodo-deoxyuridine-triphosphate as the tracer-substrate. Of the 936 sera analysed, 818 were found positive for RTI-ab, and 824 were positive in Western blot (Wb). The prevalence of RTI-ab compared to Wb was therefore 99.3%. The corresponding figure for 930 sera analysed for envelope-ab, i.e., gp41-ab, was 823 positive, and of these 930 sera 815 were Wb positive, giving a comparative prevalence of 101%. In contrast, only 678 samples of 993 analyzed for core ab, i.e., p24, were positive, giving a prevalence of 77.0% as 880 of these samples were Wb positive. Thus, RTI-ab was as prevalent as gp41-ab, and although the analyses of RTI-ab amounts in different stages showed decreasing levels in stage IV compared to stages II or III, all of the sera except 1 were found positive in stages III and IV. Further, it was found that both the few RTI-ab negative samples in stage II and the few RTI-ab positive samples among Wb negative sera were sampled in connection with seroconversion. The specificity of the RTI-ab assay was 100% in a test of 200 serum samples from HIV negative blood donors. It was concluded that RTI-ab analyses can be made highly sensitive and specific and useful for studies of HIV infection. PMID:1715898

  14. DNA-dependent protein kinase inhibits AID-induced antibody gene conversion.

    Directory of Open Access Journals (Sweden)

    Adam J L Cook

    2007-04-01

    Full Text Available Affinity maturation and class switching of antibodies requires activation-induced cytidine deaminase (AID-dependent hypermutation of Ig V(DJ rearrangements and Ig S regions, respectively, in activated B cells. AID deaminates deoxycytidine bases in Ig genes, converting them into deoxyuridines. In V(DJ regions, subsequent excision of the deaminated bases by uracil-DNA glycosylase, or by mismatch repair, leads to further point mutation or gene conversion, depending on the species. In Ig S regions, nicking at the abasic sites produced by AID and uracil-DNA glycosylases results in staggered double-strand breaks, whose repair by nonhomologous end joining mediates Ig class switching. We have tested whether nonhomologous end joining also plays a role in V(DJ hypermutation using chicken DT40 cells deficient for Ku70 or the DNA-dependent protein kinase catalytic subunit (DNA-PKcs. Inactivation of the Ku70 or DNA-PKcs genes in DT40 cells elevated the rate of AID-induced gene conversion as much as 5-fold. Furthermore, DNA-PKcs-deficiency appeared to reduce point mutation. The data provide strong evidence that double-strand DNA ends capable of recruiting the DNA-dependent protein kinase complex are important intermediates in Ig V gene conversion.

  15. The trimeric serine protease HtrA1 forms a cage-like inhibition complex with an anti-HtrA1 antibody.

    Science.gov (United States)

    Ciferri, Claudio; Lipari, Michael T; Liang, Wei-Ching; Estevez, Alberto; Hang, Julie; Stawicki, Scott; Wu, Yan; Moran, Paul; Elliott, Mike; Eigenbrot, Charles; Katschke, Kenneth J; van Lookeren Campagne, Menno; Kirchhofer, Daniel

    2015-12-01

    High temperature requirement A1 (HtrA1) is a trypsin-fold serine protease implicated in the progression of age-related macular degeneration (AMD). Our interest in an antibody therapy to neutralize HtrA1 faces the complication that the target adopts a trimeric arrangement, with three active sites in close proximity. In the present study, we describe antibody 94, obtained from a human antibody phage display library, which forms a distinct macromolecular complex with HtrA1 and inhibits the enzymatic activity of recombinant and native HtrA1 forms. Using biochemical methods and negative-staining EM we were able to elucidate the molecular composition of the IgG94 and Fab94 complexes and the associated inhibition mechanism. The 246-kDa complex between the HtrA1 catalytic domain trimer (HtrA1_Cat) and Fab94 had a propeller-like organization with one Fab bound peripherally to each protomer. Low-resolution EM structures and epitope mapping indicated that the antibody binds to the surface-exposed loops B and C of the catalytic domain, suggesting an allosteric inhibition mechanism. The HtrA1_Cat-IgG94 complex (636 kDa) is a cage-like structure with three centrally located IgG94 molecules co-ordinating two HtrA1_Cat trimers and the six active sites pointing into the cavity of the cage. In both complexes, all antigen-recognition regions (paratopes) are found to bind one HtrA1 protomer and all protomers are bound by a paratope, consistent with the complete inhibition of enzyme activity. Therefore, in addition to its potential therapeutic usefulness, antibody 94 establishes a new paradigm of multimeric serine protease inhibition. PMID:26385991

  16. XGFR*, a novel affinity-matured bispecific antibody targeting IGF-1R and EGFR with combined signaling inhibition and enhanced immune activation for the treatment of pancreatic cancer.

    Science.gov (United States)

    Schanzer, Juergen M; Wartha, Katharina; Moessner, Ekkehard; Hosse, Ralf J; Moser, Samuel; Croasdale, Rebecca; Trochanowska, Halina; Shao, Cuiying; Wang, Peng; Shi, Lei; Weinzierl, Tina; Rieder, Natascha; Bacac, Marina; Ries, Carola H; Kettenberger, Hubert; Schlothauer, Tilman; Friess, Thomas; Umana, Pablo; Klein, Christian

    2016-01-01

    The epidermal growth factor receptor (EGFR) and the insulin-like growth factor-1 receptor (IGF-1R) play critical roles in tumor growth, providing a strong rationale for the combined inhibition of IGF-1R and EGFR signaling in cancer therapy. We describe the design, affinity maturation, in vitro and in vivo characterization of the bispecific anti-IGF-1R/EGFR antibody XGFR*. XGFR* is based on the bispecific IgG antibody XGFR, which enabled heterodimerization of an IGF-1R binding scFab heavy chain with an EGFR-binding light and heavy chain by the "knobs-into-holes" technology. XGFR* is optimized for monovalent binding of human EGFR and IGF-1R with increased binding affinity for IGF-1R due to affinity maturation and highly improved protein stability to oxidative and thermal stress. It bears an afucosylated Fc-portion for optimal induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Stable Chinese hamster ovary cell clones with production yields of 2-3 g/L were generated, allowing for large scale production of the bispecific antibody. XGFR* potently inhibits EGFR- and IGF-1R-dependent receptor phosphorylation, reduces tumor cell proliferation in cells with heterogeneous levels of IGF-1R and EGFR receptor expression and induces strong ADCC in vitro. A comparison of pancreatic and colorectal cancer lines demonstrated superior responsiveness to XGFR*-mediated signaling and tumor growth inhibition in pancreatic cancers that frequently show a high degree of IGF-1R/EGFR co-expression. XGFR* showed potent anti-tumoral efficacy in the orthotopic MiaPaCa-2 pancreatic xenograft model, resulting in nearly complete tumor growth inhibition with significant number of tumor remissions. In summary, the bispecific anti-IGF-1R/EGFR antibody XGFR* combines potent signaling and tumor growth inhibition with enhanced ADCC induction and represents a clinical development candidate for the treatment of pancreatic cancer. PMID:26984378

  17. Inhibition of human immunodeficiency virus (HIV) infection in vitro by anticarbohydrate monoclonal antibodies: peripheral glycosylation of HIV envelope glycoprotein gp120 may be a target for virus neutralization

    DEFF Research Database (Denmark)

    Hansen, J E; Clausen, H; Nielsen, C;

    1990-01-01

    Carbohydrate structures are often involved in the initial adhesion of pathogens to target cells. In the present study, a panel of anticarbohydrate monoclonal antibodies (MAbs) was tested for their ability to inhibit in vitro human immunodeficiency virus infectivity. MAbs against three different N......- and O-linked carbohydrate epitopes (LeY, A1, and sialyl-Tn) were able to block infection by cell-free virus as well as inhibit syncytium formation. Inhibition of virus infectivity was independent of virus strain (HTLVIIIB or patient isolate SSI-002), the cell line used for virus propagation (H9 or MT4...

  18. A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

    International Nuclear Information System (INIS)

    The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice

  19. A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen, E-mail: srrshurology@163.com

    2015-08-14

    The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice.

  20. Characterization of a Human Antibody Fragment Fab and Its Calcium Phosphate Nanoparticles that Inhibit Rabies Virus Infection with Vaccine

    OpenAIRE

    Liu, Xinjian; Lin, Hong; Tang, Qi; Li, Chen; Yang, Songtao; Wang, Zhongcan; Wang, Changjun; He, Qing; Cao, Brian; Feng, Zhenqing; Guan, Xiaohong; Zhu, Jin

    2011-01-01

    Recombinant antibody phage display technology has been used to mimic many aspects of the processes that govern the generation and selection of high-affinity natural human antibodies in the human immune system, especially for infectious disease prophylaxis. An anti-rabies virus immunized phage-display Fab library was constructed from peripheral blood lymphocytes from vaccinated volunteers. The immunized antibody library, with a diversity of 6.7×108, was used to select and produce antibodies th...

  1. Antibody-dependent cellular inhibition is associated with reduced risk against febrile malaria in a longitudinal cohort study involving Ghanaian children

    DEFF Research Database (Denmark)

    Tiendrebeogo, Regis W; Adu, Bright; Singh, Susheel K; Dziegiel, Morten H; Nébié, Issa; Sirima, Sodiomon B; Christiansen, Michael; Dodoo, Daniel; Theisen, Michael

    2015-01-01

    studies (LCS). We investigated the relationship between ADCI activity of immunoglobulin G before malaria season and risk of malaria in a LCS involving Ghanaian children. High ADCI activity was significantly associated with reduced risk against malaria. Findings here suggest a potential usefulness of the...... ADCI assay as a correlate of protection to guide malaria vaccine studies.......The antibody-dependent respiratory burst and opsonic phagocytosis assays have been associated with protection against malaria; however, other mechanisms may also be involved. The antibody-dependent cellular inhibition (ADCI) assay is yet to be correlated with protection in longitudinal cohort...

  2. Competitive-Inhibition Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibodies to Caprine Arthritis-Encephalitis Virus: Diagnostic Tool for Successful Eradication

    OpenAIRE

    Herrmann, Lynn M.; Cheevers, William P.; McGuire, Travis C.; Adams, D. Scott; Hutton, Melinda M.; Gavin, William G.; Knowles, Donald P

    2003-01-01

    A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) was evaluated for the detection of serum antibodies to the surface envelope (SU) of caprine arthritis-encephalitis virus (CAEV) in goats. This assay utilized 96-well microtiter plates containing CAEV-63 SU captured by monoclonal antibody (MAb) F7-299 and measured the competitive displacement of horseradish peroxidase-conjugated MAb GPB 74A binding by undiluted goat sera (F. Özyörük, W. P. Cheevers, G. A. Hullinger, T. C. McGu...

  3. Detection of Serum Antibodies to Ovine Progressive Pneumonia Virus in Sheep by Using a Caprine Arthritis-Encephalitis Virus Competitive-Inhibition Enzyme-Linked Immunosorbent Assay

    OpenAIRE

    Herrmann, Lynn M.; Cheevers, William P.; Marshall, Katherine L.; McGuire, Travis C.; Hutton, Melinda M.; Lewis, Gregory S.; Knowles, Donald P

    2003-01-01

    A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) for detection of antibodies to the surface envelope (SU) of caprine arthritis-encephalitis virus (CAEV) was recently reported (L. M. Herrmann, W. P. Cheevers, T. C. McGuire, D. Scott Adams, M. M. Hutton, W. G. Gavin, and D. P. Knowles, Clin. Diagn. Lab. Immunol. 10:267-271, 2003). The cELISA utilizes CAEV-63 SU captured on microtiter plates using the monoclonal antibody (MAb) F7-299 and measures competitive displacement of bi...

  4. Inhibition of RANKL-dependent cellular fusion in pre-osteoclasts by amiloride and a NHE10-specific monoclonal antibody.

    Science.gov (United States)

    Mine, Yuichi; Shuto, Takahiro; Nikawa, Hiroki; Kawai, Toshihisa; Ohara, Masaru; Kawahara, Kazuko; Ohta, Kouji; Kukita, Toshio; Terada, Yoshihiro; Makihira, Seicho

    2015-06-01

    The functions of Na(+) /H(+) exchangers (NHEs) during osteoclastic differentiation were investigated using the NHE inhibitor amiloride and a monoclonal antibody (MAb). Compared with sRANKL-stimulated control cells, amiloride decreased the number of large TRAP-positive osteoclast cells (OCs) with ≥10 nuclei and increased the number of small TRAP-positive OCs with ≤10 nuclei during sRANKL-dependent osteoclastic differentiation of RAW264.7 cells. NHE10 mRNA expression and OC differentiation markers were increased by sRANKL stimulation in dose- and time-dependent manners. NHEs 1-9 mRNA expression was not increased by sRANKL stimulation. Similar to amiloride, a rat anti-mouse NHE10 MAb (clone 6B11) decreased the number of large TRAP-positive OCs, but increased the number of small TRAP-positive OCs. These findings suggested that inhibition of NHEs by amiloride or an anti-NHE10 MAb prevented sRANKL-promoted cellular fusion. The anti-NHE10 MAb has the potential for use as an effective inhibitor of bone resorption for targeted bone disease therapy. PMID:25612314

  5. Transcription factor Ets1, but not the closely related factor Ets2, inhibits antibody-secreting cell differentiation.

    Science.gov (United States)

    John, Shinu; Russell, Lisa; Chin, Shu Shien; Luo, Wei; Oshima, Robert; Garrett-Sinha, Lee Ann

    2014-02-01

    B cell differentiation into antibody-secreting cells (ASCs) is a tightly regulated process under the control of multiple transcription factors. One such transcription factor, Ets1, blocks the transition of B cells to ASCs via two separate activities: (i) stimulating the expression of target genes that promote B cell identity and (ii) interfering with the functional activity of the transcription factor Blimp1. Ets1 is a member of a multigene family, several members of which are expressed within the B cell lineage, including the closely related protein Ets2. In this report, we demonstrate that Ets1, but not Ets2, can block ASC formation despite the fact that Ets1 and Ets2 bind to apparently identical DNA sequence motifs and are thought to regulate overlapping sets of target genes. The DNA binding domain of Ets1 is required, but not sufficient by itself, to block ASC formation. In addition, less conserved regions within the N terminus of Ets1 play an important role in inhibiting B cell differentiation. Differences between the N termini of Ets1 and Ets2, rather than differences in the DNA binding domains, determine whether the proteins are capable of blocking ASC formation or not. PMID:24277931

  6. Soluble human CD4 elicits an antibody response in rhesus monkeys that inhibits simian immunodeficiency virus replication

    International Nuclear Information System (INIS)

    Rhesus monkeys infected with the simian immunodeficiency virus of macaques (SIVmac) demonstrate significant virologic and clinical improvement as a result of treatment with human recombinant soluble CD4 (rsCD4). The authors show that human rsCD4 does not efficiently inhibit SIVmac replication in bone marrow macrophages of rhesus monkeys and does not significantly augment bone marrow hematopoietic colony formation in vitro. However, plasma of human rsCD4-treated rhesus monkeys does exhibit significant anti-SIVmac activity in vitro. Plasma of these animals efficiently blocks SIVmac replicaton in peripheral blood lymphocytes and bone marrow macrophages. It also increases granulocyte/macrophage colony formation in vitro by bone marrow cells of SIVmac-infected monkeys. This plasma and the IgG fraction of plasma from a rhesus monkey immunized with human rsCD4 in adjuvant demonstrate reactivity with a soluble form of the rhesus monkey CD4 molecule, exhibit binding to CD4+ but not CD8+ concanavalin A-activated rhesus monkey peripheral blood lymphocytes, and precipitate the CD4 molecule from surface-labeled activated rhesus monkey peripheral blood lymphocytes. Moreover, anti-viral activity is demonstrable in the IgG fraction of plasma from a human rsCD4-immunized monkey. These studies raise the possibility that a modified human CD4 molecule serving as an immunogen might elicit an antibody response that could potentially induce a beneficial therapeutic response in human immunodeficiency virus-infected individuals

  7. Structural and Functional Analysis of a C3b-specific Antibody That Selectively Inhibits the Alternative Pathway of Complement*S⃞

    OpenAIRE

    Katschke, Kenneth J.; Stawicki, Scott; Yin, JianPing; Steffek, Micah; Xi, Hongkang; Sturgeon, Lizette; Hass, Philip E.; Loyet, Kelly M.; DeForge, Laura; Wu, Yan; van Lookeren Campagne, Menno; Wiesmann, Christian

    2009-01-01

    Amplification of the complement cascade through the alternative pathway can lead to excessive inflammation. Targeting C3b, a component central to the alternative pathway of complement, provides a powerful approach to inhibit complement-mediated immune responses and tissue injury. In the present study, phage display technology was employed to generate an antibody that selectively recognizes C3b but not the non-activated molecule C3. The crystal structure of C3b in compl...

  8. Intracytoplasmic stable expression of IgG1 antibody targeting NS3 helicase inhibits replication of highly efficient hepatitis C Virus 2a clone

    OpenAIRE

    Clementi Massimo; Burioni Roberto; Liu Gerald; Prabhu Ramesh; Gunduz Feyza; Poat Bret; Hazari Sidhartha; Chandra Partha K; Garry Robert F; Dash Srikanta

    2010-01-01

    Abstract Background Hepatitis C virus (HCV) infection is a major public health problem with more than 170 million cases of chronic infections worldwide. There is no protective vaccine currently available for HCV, therefore the development of novel strategy to prevent chronic infection is important. We reported earlier that a recombinant human antibody clone blocks viral NS3 helicase activity and inhibits replication of HCV 1b virus. This study was performed further to explore the mechanism of...

  9. CCR3 monoclonal antibody inhibits airway eosinophilic inflammation and mucus overproduction in a mouse model of asthma

    Institute of Scientific and Technical Information of China (English)

    Hua-hao SHEN; Feng XU; Gen-sheng ZHANG; Shao-bin WANG; Wei-hua XU

    2006-01-01

    Aim: To explore the effect of a rat anti-mouse CC-chemokine receptor-3 (CCR3) monoclonal antibody (CCR3 mAb) on airway eosinophilia and mucus overproduction in asthmatic mice. Methods: An asthma model was sensitized and challenged by ovalbumin (OVA) in male C57BL/6 mice. Asthmatic mice were given dual administration (intraperitoneal injection and aerosol inhalation) of CCR3 mAb or nonspecific rat IgG (ns-IgG). The number of total and differential inflammatory cells in the bronchial alveolar lavage fluid (BALF) was counted. Eosinophils number, the goblet cell percentage (GCP) and airway mucus index (AMI) were measured in the lung tissues. Interleukin (IL)-5 levels in the BALF were examined. The expression of MUC5AC and the epidermal growth factor receptor (EGFR) mRNA in the lung tissues was detected by semi-quantitative RT-PCR. The results were compared among the groups. Results: CCR3 mAb significantly suppressed the increased eosinophils in the BALF and lung tissues in OVA-challenged mice compared with ns-IgG-treated mice. IL-5 levels in the BALF in CCR3 mAb and ns-IgG administration mice exhibited no obvious changes relative to OVA-challenged asthmatic mice. CCR3 mAb reduced the increased GCP and AMI after OVA challenge and decreased the enhanced expression of MUC5AC and EGFR mRNA in lung tissues in asthmatic animals. Conclusion: CCR3 mAb can significantly inhibit airway eosinophilia and mucus overproduction in asthmatic mice. Blockage of CCR3 may represent a new strategy to asthma therapy.

  10. Anomalous expression of Thy1 (CD90) in B-cell lymphoma cells and proliferation inhibition by anti-Thy1 antibody treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ishiura, Yoshihito [Department of Biochemistry, Kochi University Medical School, Kohasu, Okocho, Nankoku, Kochi 783-8505 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kotani, Norihiro, E-mail: kotani@kochi-u.ac.jp [CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kochi System Glycobiology Center, Kochi University Medical School, Kohasu, Okocho, Nankoku, Kochi 783-8505 (Japan); Yamashita, Ryusuke [Department of Biochemistry, Kochi University Medical School, Kohasu, Okocho, Nankoku, Kochi 783-8505 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Yamamoto, Harumi [Laboratory of Membrane Biochemistry and Biophysics, Graduate School of Biostudies, Kyoto University, Yoshida Shimo-Adachi, Sakyo, Kyoto 606-8501 (Japan); Kozutsumi, Yasunori [CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Laboratory of Membrane Biochemistry and Biophysics, Graduate School of Biostudies, Kyoto University, Yoshida Shimo-Adachi, Sakyo, Kyoto 606-8501 (Japan); Honke, Koichi [Department of Biochemistry, Kochi University Medical School, Kohasu, Okocho, Nankoku, Kochi 783-8505 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kochi System Glycobiology Center, Kochi University Medical School, Kohasu, Okocho, Nankoku, Kochi 783-8505 (Japan)

    2010-05-28

    The anti-CD20 monoclonal antibody (Ab) rituximab is accepted to be an effective therapeutic Ab for malignant B-cell lymphoma; however, discovery of other cell surface antigens is required for the option of antibody medicine. Considering that many tumor-associated antigens are glycans, we have searched glycoconjugates for the candidate antigens that therapeutic Abs target. To this end, we first focused on the difference in the glycogenes expression in terms of Epstein-Barr virus (EBV) infection of a Burkitt's lymphoma cell line, Akata. Using DNA array, flow cytometry and Western blotting, we found that Thy1 was highly expressed in EBV-positive Akata cells. Subsequently, Thy1 was found to be expressed in other B-cell lymphoma cell lines: BJAB, MutuI, and MutuIII, irrespective of EBV infection. Treatment of these cells with an anti-Thy1 monoclonal antibody inhibited proliferation more strongly than the therapeutic Ab rituximab. The B-cell lymphoma cell lines were classified based on the extent of the proliferation inhibition, which was not correlated with the expression level of Thy1. It is suggested that stable residence of receptor tyrosine kinases in lipid rafts sustains cell growth in B-cell lymphoma cells.

  11. An anti-CCR5 monoclonal antibody and small molecule CCR5 antagonists synergize by inhibiting different stages of human immunodeficiency virus type 1 entry

    International Nuclear Information System (INIS)

    HIV-1 coreceptors are attractive targets for novel antivirals. Here, inhibition of entry by two classes of CCR5 antagonists was investigated. We confirmed previous findings that HIV-1 isolates vary greatly in their sensitivity to small molecule inhibitors of CCR5-mediated entry, SCH-C and TAK-779. In contrast, an anti-CCR5 monoclonal antibody (PA14) similarly inhibited entry of diverse viral isolates. Sensitivity to small molecules was V3 loop-dependent and inversely proportional to the level of gp120 binding to CCR5. Moreover, combinations of the MAb and small molecules were highly synergistic in blocking HIV-1 entry, suggesting different mechanisms of action. This was confirmed by time course of inhibition experiments wherein the PA14 MAb and small molecules were shown to inhibit temporally distinct stages of CCR5 usage. We propose that small molecules inhibit V3 binding to the second extracellular loop of CCR5, whereas PA14 preferentially inhibits subsequent events such as CCR5 recruitment into the fusion complex or conformational changes in the gp120-CCR5 complex that trigger fusion. Importantly, our findings suggest that combinations of CCR5 inhibitors with different mechanisms of action will be central to controlling HIV-1 infection and slowing the emergence of resistant strains

  12. Generation and Characterization of C305, a Murine Neutralizing scFv Antibody That Can Inhibit BLyS Binding to Its Receptor BCMA

    Institute of Scientific and Technical Information of China (English)

    Mei-Yun LIU; Wei HAN; Yan-Li DING; Tian-Hong ZHOU; Rui-Yang TIAN; Sheng-Li YANG; Hui LIU; Yi GONG

    2005-01-01

    B-lymphocyte stimulator (BLyS) is a member of the tumor necrosis factor (TNF) family and a key regulator of B cell response. Neutralizing single-chain fragment variable (scFv) antibody against BLyS binding to its receptor BCMA has the potential to play a prominent role in autoimmune disease therapy. A phage display scFv library constructed on pIII protein of M13 filamentous phage was screened using BLyS.After five rounds of panning, their binding activity was characterized by phage-ELISA. Nucleotide sequencing revealed that at least two different scFv gene fragments (C305 and D416) were obtained. The two different scFv gene fragments were expressed to obtain the soluble scFv antibodies, then the soluble scFv antibodies were characterized by means of competitive ELISA and in vitro neutralization assay. The results indicated that C305 is the neutralizing scFv antibody that can inhibit BLyS binding to its receptor BCMA.

  13. Inhibition of the Production of Anti-OspA Borreliacidal Antibody with T Cells from Hamsters Vaccinated against Borrelia burgdorferi

    OpenAIRE

    Jensen, Jani R.; Du Chateau, Brian K.; Munson, Erik L.; Callister, Steven M.; Schell, Ronald F.

    1998-01-01

    The serious morbidity associated with Lyme borreliosis has focused considerable effort on the development of a comprehensive vaccine for protection against infection with Borrelia burgdorferi. Induction of borreliacidal antibody by vaccination or infection has been shown to correlate with protection of humans and animals against infection with the Lyme spirochete. In this report, we showed that high levels of borreliacidal antibody (titer of 1,280) were produced in vitro when T and B cells fr...

  14. Primary structure of the 175K Plasmodium falciparum erythrocyte binding antigen and identification of a peptide which elicits antibodies that inhibit malaria merozoite invasion.

    Science.gov (United States)

    Sim, B K; Orlandi, P A; Haynes, J D; Klotz, F W; Carter, J M; Camus, D; Zegans, M E; Chulay, J D

    1990-11-01

    The Plasmodium falciparum gene encoding erythrocyte binding antigen-175 (EBA-175), a putative receptor for red cell invasion (Camus, D., and T. J. Hadley. 1985. Science (Wash. DC). 230:553-556.), has been isolated and characterized. DNA sequencing demonstrated a single open reading frame encoding a translation product of 1,435 amino acid residues. Peptides corresponding to regions on the deduced amino acid sequence predicted to be B cell epitopes were assessed for immunogenicity. Immunization of mice and rabbits with EBA-peptide 4, a synthetic peptide encompassing amino acid residues 1,062-1,103, produced antibodies that recognized P. falciparum merozoites in an indirect fluorescent antibody assay. When compared to sera from rabbits immunized with the same adjuvant and carrier protein, sera from rabbits immunized with EBA-peptide 4 inhibited merozoite invasion of erythrocytes in vitro by 80% at a 1:5 dilution. Furthermore, these sera inhibited the binding of purified, authentic EBA-175 to erythrocytes, suggesting that their activity in inhibiting merozoite invasion of erythrocytes is mediated by blocking the binding of EBA-175 to erythrocytes. Since the nucleotide sequence of EBA-peptide 4 is conserved among seven strains of P. falciparum from throughout the world (Sim, B. K. L. 1990. Mol. Biochem. Parasitol. 41:293-296.), these data identify a region of the protein that should be a focus of vaccine development efforts. PMID:2229177

  15. Competitive-inhibition enzyme-linked immunosorbent assay for detection of serum antibodies to caprine arthritis-encephalitis virus: diagnostic tool for successful eradication.

    Science.gov (United States)

    Herrmann, Lynn M; Cheevers, William P; McGuire, Travis C; Adams, D Scott; Hutton, Melinda M; Gavin, William G; Knowles, Donald P

    2003-03-01

    A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) was evaluated for the detection of serum antibodies to the surface envelope (SU) of caprine arthritis-encephalitis virus (CAEV) in goats. This assay utilized 96-well microtiter plates containing CAEV-63 SU captured by monoclonal antibody (MAb) F7-299 and measured the competitive displacement of horseradish peroxidase-conjugated MAb GPB 74A binding by undiluted goat sera (F. Ozyörük, W. P. Cheevers, G. A. Hullinger, T. C. McGuire, M. Hutton, and D. P. Knowles, Clin. Diagn. Lab. Immunol. 8:44-51, 2001). Two hundred serum samples from goats in the United States were used to determine the sensitivity and specificity of cELISA based on the immunoprecipitation (IP) of [(35)S]methionine-labeled viral antigens as a standard of comparison. A positive cELISA was defined as >33.2% inhibition of MAb 74A binding based on 2 standard deviations above the mean percent inhibition of 140 IP-negative serum samples. At this cutoff value, there were 0 of 60 false-negative sera (100% sensitivity) and 5 of 140 false-positive sera (96.4% specificity). Additional studies utilized IP-monitored cELISA to establish a CAEV-free herd of 1,640 dairy goats. PMID:12626453

  16. An A1-A1 mutant with improved binding and inhibition of β2GPI/antibody complexes in antiphospholipid syndrome.

    Science.gov (United States)

    Kolyada, Alexey; Karageorgos, Ioannis; Mahlawat, Pardeep; Beglova, Natalia

    2015-03-01

    β2 glycoprotein I (β2GPI) is the most common antigen for autoimmune antibodies in antiphospholipid syndrome (APS). Thrombosis is a clinical feature of APS. We created a molecule (A1-A1) that consists of two identical β2GPI-binding modules from ApoE receptor 2 (ApoER2). A1-A1 binds to β2GPI/antibody complexes, preventing their association with ApoER2 and anionic phospholipids, and reducing thrombus size in the mouse model of APS. Here, we describe a mutant of A1-A1 (mA1-A1ND) with improved affinity for β2GPI. mA1-A1ND inhibits the binding of β2GPI to cardiolipin in the presence of anti-β2GPI antibodies, and inhibits the binding to phospholipids in plasma samples of APS patients, affecting the clotting time. Reduction of the clotting time demonstrates the presence of soluble β2GPI/antibody complexes in patients' plasma. These complexes either already exist in patients' plasma or form rapidly in the proximity to phospholipids. All members of the low-density lipoprotein receptor family bind β2GPI. Modeling studies of A1 in a complex with domain V of β2GPI (β2GPI-DV) revealed two possible modes of interaction of a ligand-binding module from lipoprotein receptors with β2GPI-DV. In both orientations, the ligand-binding module interferes with binding of β2GPI to anionic phospholipids; however, it interacts with two different but overlapping sets of lysine residues in β2GPI-DV, depending on the orientation. PMID:25546421

  17. Inhibition of HIV Env binding to cellular receptors by monoclonal antibody 2G12 as probed by Fc-tagged gp120

    Directory of Open Access Journals (Sweden)

    Wilson Ian A

    2006-07-01

    Full Text Available Abstract During natural HIV infection, an array of host receptors are thought to influence virus attachment and the kinetics of infection. In this study, to probe the interactions of HIV envelope (Env with various receptors, we assessed the inhibitory properties of various anti-Env monoclonal antibodies (mAbs in binding assays. To assist in detecting Env in attachment assays, we generated Fc fusions of full-length wild-type gp120 and several variable loop-deleted gp120s. Through investigation of the inhibition of Env binding to cell lines expressing CD4, CCR5, DC-SIGN, syndecans or combinations thereof, we found that the broadly neutralizing mAb, 2G12, directed to a unique carbohydrate epitope of gp120, inhibited Env-CCR5 binding, partially inhibited Env-DC-SIGN binding, but had no effect on Env-syndecan association. Furthermore, 2G12 inhibited Env attachment to primary monocyte-derived dendritic cells, that expressed CD4 and CCR5 primary HIV receptors, as well as DC-SIGN, and suggested that the dual activities of 2G12 could be valuable in vivo for inhibiting initial virus dissemination and propagation.

  18. A heterodimer of a VHH (variable domains of camelid heavy chain-only) antibody that inhibits anthrax toxin cell binding linked to a VHH antibody that blocks oligomer formation is highly protective in an anthrax spore challenge model.

    Science.gov (United States)

    Moayeri, Mahtab; Leysath, Clinton E; Tremblay, Jacqueline M; Vrentas, Catherine; Crown, Devorah; Leppla, Stephen H; Shoemaker, Charles B

    2015-03-01

    Anthrax disease is caused by a toxin consisting of protective antigen (PA), lethal factor, and edema factor. Antibodies against PA have been shown to be protective against the disease. Variable domains of camelid heavy chain-only antibodies (VHHs) with affinity for PA were obtained from immunized alpacas and screened for anthrax neutralizing activity in macrophage toxicity assays. Two classes of neutralizing VHHs were identified recognizing distinct, non-overlapping epitopes. One class recognizes domain 4 of PA at a well characterized neutralizing site through which PA binds to its cellular receptor. A second neutralizing VHH (JKH-C7) recognizes a novel epitope. This antibody inhibits conversion of the PA oligomer from "pre-pore" to its SDS and heat-resistant "pore" conformation while not preventing cleavage of full-length 83-kDa PA (PA83) by cell surface proteases to its oligomer-competent 63-kDa form (PA63). The antibody prevents endocytosis of the cell surface-generated PA63 subunit but not preformed PA63 oligomers formed in solution. JKH-C7 and the receptor-blocking VHH class (JIK-B8) were expressed as a heterodimeric VHH-based neutralizing agent (VNA2-PA). This VNA displayed improved neutralizing potency in cell assays and protected mice from anthrax toxin challenge with much better efficacy than the separate component VHHs. The VNA protected virtually all mice when separately administered at a 1:1 ratio to toxin and protected mice against Bacillus anthracis spore infection. Thus, our studies show the potential of VNAs as anthrax therapeutics. Due to their simple and stable nature, VNAs should be amenable to genetic delivery or administration via respiratory routes. PMID:25564615

  19. Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Du Li

    2010-08-01

    Full Text Available Abstract Background Overexpression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study, the single-chain variable antibody fragments (scFv targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. Methods DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of γH2AX foci. The radiosensitization in vivo was determined on Balb/c athymic mice transplanted tumours of HeLa cells. Results Four epitopes of DNA-PKcs have been predicted and expressed as the antigens, and a specific human anti-DNA-PKcs scFv antibody gene, anti-DPK3-scFv, was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified, in vitro. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR, decreased repair capability of DNA double-strand breaks (DSB detected by comet assay and immunofluorescence detection of γH2AX foci. Moreover, the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv, which was displayed by the decreased phosphorylation levels of its target Akt/S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and apoptosis rates showed that anti-DPK3-scFv enhanced the sensitivity of tumours transplanted in Balb/c athymic mice to radiation therapy. Conclusion The antiproliferation and radiosensitizing effects of anti-DPK3-scFv via targeting DNA-PKcs make it very appealing for the development as a novel biological radiosensitizer for cancer

  20. Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo

    International Nuclear Information System (INIS)

    Overexpression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study, the single-chain variable antibody fragments (scFv) targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of γH2AX foci. The radiosensitization in vivo was determined on Balb/c athymic mice transplanted tumours of HeLa cells. Four epitopes of DNA-PKcs have been predicted and expressed as the antigens, and a specific human anti-DNA-PKcs scFv antibody gene, anti-DPK3-scFv, was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified, in vitro. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR, decreased repair capability of DNA double-strand breaks (DSB) detected by comet assay and immunofluorescence detection of γH2AX foci. Moreover, the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv, which was displayed by the decreased phosphorylation levels of its target Akt/S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and apoptosis rates showed that anti-DPK3-scFv enhanced the sensitivity of tumours transplanted in Balb/c athymic mice to radiation therapy. The antiproliferation and radiosensitizing effects of anti-DPK3-scFv via targeting DNA-PKcs make it very appealing for the development as a novel biological radiosensitizer for cancer therapeutic potential

  1. Liposomes loaded with P. falciparum merozoite-derived proteins are highly immunogenic and produce invasion-inhibiting and anti-toxin antibodies.

    Science.gov (United States)

    Fotoran, Wesley L; Santangelo, Rachele M; Medeiros, Márcia M; Colhone, Marcelle; Ciancaglini, Pietro; Barboza, Renato; Marinho, Claudio Romero Farias; Stábeli, Rodrigo Guerino; Wunderlich, Gerhard

    2015-11-10

    The formulation of an effective vaccine against malaria is still a significant challenge and the induction of high anti-parasite antibody titers plus a sustained T cell response is mandatory for the success of such a vaccine. We have developed a nanoliposome-based structure which contains plasma membrane-associated proteins (PfMNP) of Plasmodium falciparum merozoites on its surface. Incorporation of parasite-derived proteins led to a significant increase in the size and dispersity of particles. Immunization of particles in BalbC and C57BL/6 mice led to high anti-MSP119 IgG titers (10(4)) after the first dose and reached a plateau (>10(6)) after the third dose. While very high titers were observed against the C-terminal domain of the vaccine candidate MSP1, only modest titers (≤10(3)) were detected against MSP2. The induced antibodies showed also a strong growth-inhibiting effect in reinvasion assays. In addition, PfMNP immunization generated antibodies which partially blocked the inflammatory response, probably by blocking TLR-induced activation of macrophages by malarial toxins such as GPI anchors. The results underline the potential of nanoliposome-based formulations as anti-malarial vaccines. PMID:26334481

  2. Inhibition of the alternative complement activation pathway in traumatic brain injury by a monoclonal anti-factor B antibody: a randomized placebo-controlled study in mice

    Directory of Open Access Journals (Sweden)

    Holers V Michael

    2007-05-01

    Full Text Available Abstract Background The posttraumatic response to traumatic brain injury (TBI is characterized, in part, by activation of the innate immune response, including the complement system. We have recently shown that mice devoid of a functional alternative pathway of complement activation (factor B-/- mice are protected from complement-mediated neuroinflammation and neuropathology after TBI. In the present study, we extrapolated this knowledge from studies in genetically engineered mice to a pharmacological approach using a monoclonal anti-factor B antibody. This neutralizing antibody represents a specific and potent inhibitor of the alternative complement pathway in mice. Methods A focal trauma was applied to the left hemisphere of C57BL/6 mice (n = 89 using a standardized electric weight-drop model. Animals were randomly assigned to two treatment groups: (1 Systemic injection of 1 mg monoclonal anti-factor B antibody (mAb 1379 in 400 μl phosphate-buffered saline (PBS at 1 hour and 24 hours after trauma; (2 Systemic injection of vehicle only (400 μl PBS, as placebo control, at identical time-points after trauma. Sham-operated and untreated mice served as additional negative controls. Evaluation of neurological scores and analysis of brain tissue specimens and serum samples was performed at defined time-points for up to 1 week. Complement activation in serum was assessed by zymosan assay and by murine C5a ELISA. Brain samples were analyzed by immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL histochemistry, and real-time RT-PCR. Results The mAb 1379 leads to a significant inhibition of alternative pathway complement activity and to significantly attenuated C5a levels in serum, as compared to head-injured placebo-treated control mice. TBI induced histomorphological signs of neuroinflammation and neuronal apoptosis in the injured brain hemisphere of placebo-treated control mice for up to 7 days. In contrast, the

  3. In-vitro inhibition of IFNγ+ iTreg mediated by monoclonal antibodies against cell surface determinants essential for iTreg function

    Directory of Open Access Journals (Sweden)

    Daniel Volker

    2012-08-01

    Full Text Available Abstract Background IFNγ-producing CD4+CD25+Foxp3+ PBL represent a subtype of iTreg that are associated with good long-term graft outcome in renal transplant recipients and suppress alloresponses in-vitro. To study the mechanism of immunosuppression, we attempted to block cell surface receptors and thereby inhibited the function of this iTreg subset in-vitro using monoclonal antibodies and recombinant proteins. Methods PBL of healthy control individuals were stimulated polyclonally in-vitro in the presence of monoclonal antibodies or recombinant proteins against/of CD178, CD152, CD279, CD28, CD95, and HLA-DR. Induction of IFNγ+ iTreg and proliferation of effector cells was determined using four-color fluorescence flow cytometry. Blockade of iTreg function was analyzed using polyclonally stimulated co-cultures with separated CD4+CD25+CD127-IFNγ+ PBL. Results High monoclonal antibody concentrations inhibited the induction of CD4+CD25+Foxp3+IFNγ+ PBL (anti-CD152, anti-CD279, anti-CD95: p +CD25+CD127-IFNγ+ PBL (anti-CD178, anti-CD152, anti-CD279, anti-CD95: p +CD25+Foxp3+IFNγ+ PBL (rCD152 and rCD95: p +CD25+CD127-IFNγ+ PBL showed lower cell proliferation than co-cultures with CD4+CD25+CD127-IFNγ- PBL (p +CD25+CD127-IFNγ- PBL-containing co-cultures in the presence of monoclonal antibody (anti-CD28, anti-CD152, anti-CD279: p +CD25+CD127-IFNγ+ PBL (with the exception anti-CD28 monoclonal antibody: p +CD25+CD127-IFNγ- PBL but do not efficiently block suppressive iTreg function in co-cultures with CD4+CD25+CD127-IFNγ+ PBL. Conclusions CD178, CD152, CD279, CD28, CD95, and HLA-DR determinants are important for induction and suppressive function of IFNγ+ iTreg.

  4. EGFR targeting monoclonal antibody combines with an mTOR inhibitor and potentiates tumor inhibition by acting on complementary signaling hubs

    International Nuclear Information System (INIS)

    Nimotuzumab, an anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibody, has been used extensively in many solid tumors and confers significant survival advantage. The antibody has limited skin toxicity and is generally well tolerated. Similar to other anti-EGFR therapies, patients may relapse a few months after treatment. In this study we show for the first time, the use of Nimotuzumab along with Sirolimus has synergistic effect on tumor inhibition as compared with the drugs used individually, in Nimotuzumab responsive and nonresponsive cell lines. In vitro studies prove that while Sirolimus (25 nmol/L) affects the signal downstream to mammalian target of rapamycin (mTOR), Nimotuzumab (83 nmol/L) downregulates pTYR, pMAPK and pSTAT3 by 40%, 20% and 30%, respectively. The combination, targeting these two different signaling hubs, may be associated with the synergistic inhibition observed. In vivo, the use of half human therapeutic equivalent doses for both the drugs substantially reduces tumors established in nude as well as severe combined immunodeficiency (SCID) mice by EGFR overexpressing A-431 cells. The drug combination reduces cell proliferation and the expression of signal transduction molecules. Treated tumors are better differentiated as compared with those established in the control mice. Tumor microarray demonstrates that Nimotuzumab and the combination groups segregate independently to the Sirolimus and the control treatment. The combination uniquely downregulated 55% of the altered tumor genes, extending beyond the typical pathways associated with Nimotuzumab and Sirolimus downstream pathways inhibition. These results would suggest that this nontoxic drug combination improves therapeutic benefit even in patients with low-EGFR expression and severely immunocompromised because of their current medication

  5. CD44 Antibody Inhibition of Macrophage Phagocytosis Targets Fcγ Receptor- and Complement Receptor 3-Dependent Mechanisms.

    Science.gov (United States)

    Amash, Alaa; Wang, Lin; Wang, Yawen; Bhakta, Varsha; Fairn, Gregory D; Hou, Ming; Peng, Jun; Sheffield, William P; Lazarus, Alan H

    2016-04-15

    Targeting CD44, a major leukocyte adhesion molecule, using specific Abs has been shown beneficial in several models of autoimmune and inflammatory diseases. The mechanisms contributing to the anti-inflammatory effects of CD44 Abs, however, remain poorly understood. Phagocytosis is a key component of immune system function and can play a pivotal role in autoimmune states where CD44 Abs have shown to be effective. In this study, we show that the well-known anti-inflammatory CD44 Ab IM7 can inhibit murine macrophage phagocytosis of RBCs. We assessed three selected macrophage phagocytic receptor systems: Fcγ receptors (FcγRs), complement receptor 3 (CR3), and dectin-1. Treatment of macrophages with IM7 resulted in significant inhibition of FcγR-mediated phagocytosis of IgG-opsonized RBCs. The inhibition of FcγR-mediated phagocytosis was at an early stage in the phagocytic process involving both inhibition of the binding of the target RBC to the macrophages and postbinding events. This CD44 Ab also inhibited CR3-mediated phagocytosis of C3bi-opsonized RBCs, but it did not affect the phagocytosis of zymosan particles, known to be mediated by the C-type lectin dectin-1. Other CD44 Abs known to have less broad anti-inflammatory activity, including KM114, KM81, and KM201, did not inhibit FcγR-mediated phagocytosis of RBCs. Taken together, these findings demonstrate selective inhibition of FcγR and CR3-mediated phagocytosis by IM7 and suggest that this broadly anti-inflammatory CD44 Ab inhibits these selected macrophage phagocytic pathways. The understanding of the immune-regulatory effects of CD44 Abs is important in the development and optimization of therapeutic strategies for the potential treatment of autoimmune conditions. PMID:26944929

  6. Detection of Anaplasma antibodies in wildlife and domestic species in wildlife-livestock interface areas of Kenya by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay

    OpenAIRE

    J.J.N. Ngeranwa; S.P. Shompole; E.H. Venter; Wambugu, A.; J.E. Crafford; Penzhorn, B.L.

    2008-01-01

    The seroprevalence of Anaplasma antibodies in wildlife (eland, blue wildebeest, kongoni, impala, Thomson's gazelle, Grant's gazelle, giraffe and plains zebra) and domestic animal (cattle, sheep and goat) populations was studied in wildlife / livestock interface areas of Kenya. Serum samples were analyzed by competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA), using a recombinant antigen (MSP-5) from Anaplasma marginale surface membrane. A monoclonal antibody, FC-16, was ...

  7. Detection of serum antibodies to ovine progressive pneumonia virus in sheep by using a caprine arthritis-encephalitis virus competitive-inhibition enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Herrmann, Lynn M; Cheevers, William P; Marshall, Katherine L; McGuire, Travis C; Hutton, Melinda M; Lewis, Gregory S; Knowles, Donald P

    2003-09-01

    A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) for detection of antibodies to the surface envelope (SU) of caprine arthritis-encephalitis virus (CAEV) was recently reported (L. M. Herrmann, W. P. Cheevers, T. C. McGuire, D. Scott Adams, M. M. Hutton, W. G. Gavin, and D. P. Knowles, Clin. Diagn. Lab. Immunol. 10:267-271, 2003). The cELISA utilizes CAEV-63 SU captured on microtiter plates using the monoclonal antibody (MAb) F7-299 and measures competitive displacement of binding of the anti-CAEV MAb GPB 74A by goat serum. The present study evaluated the CAEV cELISA for detection of antibodies to ovine progressive pneumonia virus (OPPV) in sheep. Three hundred thirty-two sera were randomly selected from 21,373 sheep sera collected throughout the United States to determine the sensitivity and specificity of cELISA and agar gel immunodiffusion (AGID) based on immunoprecipitation (IP) of [35S]methionine-labeled OPPV antigens as a standard of comparison. A positive cELISA test was defined as >20.9 percent inhibition (% I) of MAb 74A binding based on two standard deviations above the mean % I of 191 IP-negative sheep sera. At this cutoff, there were 2 of 141 false-negative sera (98.6% sensitivity) and 6 of 191 false-positive sera (96.9% specificity). Sensitivity and specificity values for IP-monitored AGID were comparable to those for cELISA for 314 of 332 sera with unambiguous AGID results. Concordant results by cELISA and IP resolved 16 of the 18 sera that were indeterminate by AGID. Additional studies evaluated cELISA by using 539 sera from a single OPPV-positive flock. Based on IP of 36 of these sera, there was one false-negative by cELISA among 21 IP-positive sera (95.5% sensitivity) and 0 of 15 false-positives (100% specificity). We conclude that the CAEV cELISA can be applied to detection of OPPV antibodies in sheep with high sensitivity and specificity. PMID:12965917

  8. Monoclonal antibodies to conformational epitopes of the surface glycoprotein of caprine arthritis-encephalitis virus: potential application to competitive-inhibition enzyme-linked immunosorbent assay for detecting antibodies in goat sera.

    Science.gov (United States)

    Ozyörük, F; Cheevers, W P; Hullinger, G A; McGuire, T C; Hutton, M; Knowles, D P

    2001-01-01

    Four immunoglobulin G1 monoclonal antibodies (MAbs) to the gp135 surface envelope glycoprotein (SU) of the 79-63 isolate of caprine arthritis-encephalitis virus (CAEV), referred to as CAEV-63, were characterized and evaluated for their ability to compete with antibody from CAEV-infected goats. Three murine MAbs (MAbs GPB16A, 29A, and 74A) and one caprine MAb (MAb F7-299) were examined. All MAbs reacted in nitrocellulose dot blots with native CAEV-63 SU purified by MAb F7-299 affinity chromatography, whereas none reacted with denatured and reduced SU. All MAbs reacted in Western blots with purified CAEV-63 SU or the SU component of whole-virus lysate following denaturation in the absence of reducing agent, indicating that intramolecular disulfide bonding was essential for epitope integrity. Peptide-N-glycosidase F digestion of SU abolished the reactivities of MAbs 74A and F7-299, whereas treatment of SU with N-acetylneuraminate glycohydrolase (sialidase A) under nonreducing conditions enhanced the reactivities of all MAbs as well as polyclonal goat sera. MAbs 29A and F7-299 were cross-reactive with the SU of an independent strain of CAEV (CAEV-Co). By enzyme-linked immunosorbent assay (ELISA), the reactivities of horseradish peroxidase (HRP)-conjugated MAbs 16A and 29A with homologous CAEV-63 SU were MAb 74A. The reactivity of HRP-conjugated MAb 74A was blocked by sera from goats immunized with CAEV-63 SU or infected with CAEV-63. The reactivity of MAb 74A was also blocked by sera from goats infected with a CAEV-Co molecular clone, although MAb 74A did not react with CAEV-Co SU in Western blots. Thus, goats infected with either CAEV-63 or CAEV-Co make antibodies that inhibit binding of MAb 74A to CAEV-63 SU. A competitive-inhibition ELISA based on displacement of MAb 74A reactivity has potential applicability for the serologic diagnosis of CAEV infection. PMID:11139194

  9. Anti-IGF-1R monoclonal antibody inhibits the carcinogenicity activity of acquired trastuzumab-resistant SKOV3

    OpenAIRE

    Wang, Wei; Yan ZHANG; Lv, Ming; Feng, Jiannan; Peng, Hui; Geng, Jing; Lin, Zhou; Zhou, Tingting; Li, Xinying; Shen, Beifen; Ma, Yuanfang; Qiao, Chunxia

    2014-01-01

    Background Antibody resistance, not only de novo but also acquired cases, usually exists and is related with lower survival rate and high risk of recurrence. Reversing the resistance often results in better clinical therapeutic effect. Previously, we established a trastuzumab-resistant ovarian cancer cell line, named as SKOV3-T, with lower HER2 and induced higher IGF-1R expression level to keep cell survival. Methods IGF-1R was identified important for SKOV3-T growth. Then, a novel anti-IGF-1...

  10. A Recombinant Humanized Anti-Cocaine Monoclonal Antibody Inhibits the Distribution of Cocaine to the Brain in Rats

    OpenAIRE

    Norman, Andrew B.; Gooden, Felicia C. T.; Tabet, Michael R.; Ball, William J.

    2014-01-01

    The monoclonal antibody (mAb), h2E2, is a humanized version of the chimeric human/murine anti-cocaine mAb 2E2. The recombinant h2E2 protein was produced in vitro from a transfected mammalian cell line and retained high affinity (4 nM Kd) and specificity for cocaine over its inactive metabolites benzoylecgonine (BE) and ecgonine methyl ester. In rats, pharmacokinetic studies of h2E2 (120 mg/kg i.v.) showed a long terminal elimination half-life of 9.0 days and a low volume of distribution at st...

  11. Monoclonal antibody OKM5 inhibits the in vitro binding of Plasmodium falciparum-infected erythrocytes to monocytes, endothelial, and C32 melanoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Barnwell, J.W.; Ockenhouse, C.F.; Knowles, D.M. II

    1985-11-01

    Plasmodium falciparum-infected erythrocytes bind in vitro to human endothelial cells, monocytes, and a certain melanoma cell line. Evidence suggests that this interaction is mediated by similar mechanisms which lead to the sequestration of parasitized erythrocytes in vivo through their attachment to endothelial cells of small blood vessels. They show here the monoclonal antibody OKM5, previously shown to react with the membranes of endothelial cells, monocyte,s and platelets, also reacts with the C32 melanoma cell line which also binds P. falciparum-infected erythrocytes. At relatively low concentrations, OKM5 inhibits and reverses the in vitro adherence of infected erythrocytes to target cells. As with monocytes, OKM5 antibody recognizes an /sup 125/I-labeled protein of approximately 88 Kd on the surface of C32 melanoma cells. It seems likely, therefore, that the 88 Kd polypeptide plays a role in cytoadherence, possibly as the receptor or part of a receptor for a ligand on the surface of infected erythrocytes.

  12. A novel mechanism for antibody-based anthrax toxin neutralization: inhibition of prepore-to-pore conversion.

    Science.gov (United States)

    Mechaly, Adva; Levy, Haim; Epstein, Eyal; Rosenfeld, Ronit; Marcus, Hadar; Ben-Arie, Einat; Shafferman, Avigdor; Ordentlich, Arie; Mazor, Ohad

    2012-09-21

    Protective antigen (PA), a key component of anthrax toxin, mediates the entry of lethal factor (LF) or edema factor (EF) through a membranal pore into target cells. We have previously reported the isolation and chimerization of cAb29, an anti-PA monoclonal antibody that effectively neutralizes anthrax toxin in an unknown mechanism. The aim of this study was to elucidate the neutralizing mechanism of this antibody in vitro and to test its ability to confer post-exposure protection against anthrax in vivo. By systematic evaluation of the steps taking place during the PA-based intoxication process, we found that cAb29 did not interfere with the initial steps of intoxication, namely its ability to bind to the anthrax receptor, the consecutive proteolytic cleavage to PA(63), oligomerization, prepore formation, or LF binding. However, the binding of cAb29 to the prepore prevented its pH-triggered transition to the transmembranal pore, thus preventing the last step of intoxication, i.e. the translocation of LF/EF into the cell. Epitope mapping, using a phage display peptide library, revealed that cAb29 binds the 2α(1) loop in domain 2 of PA, a loop that undergoes major conformational changes during pore formation. In vivo, we found that 100% of anthrax-infected rabbits survived when treated with cAb29 12 h after exposure. In conclusion, these experiments demonstrate that cAb29 exerts its potent neutralizing activity in a unique manner by blocking the prepore-to-pore conversion process. PMID:22869370

  13. Selection of single-chain antibodies that specifically interact with vesicular stomatitis virus (VSV) nucleocapsid and inhibit viral RNA synthesis.

    OpenAIRE

    Cortay, Jean-Claude; Gerlier, Denis; Iseni, Frédéric

    2006-01-01

    The RNA genome of non-segmented negative-strand RNA viruses is completely covered by the nucleoprotein (N) forming a ribonucleoprotein complex, the nucleocapsid. The nucleocapsid functions as the template for viral RNA synthesis that is mediated by a viral RNA-dependent RNA polymerase. It is postulated that the selection of molecules that would specifically target the nucleocapsid and thus inhibit the viral polymerase activity could represent a common approach to block negative-strand RNA vir...

  14. Comparative measurement of equine influenza virus antibodies in horse sera by single radial hemolysis, neutralization, and hemagglutination inhibition tests.

    OpenAIRE

    Yamagishi, H; Nagamine, T; Shimoda, K; Ide, S.; Igarashi, Y; Yoshioka, I; Matumoto, M

    1982-01-01

    Single radial hemolysis (SRH), neutralization (NT), and hemagglutination inhibition (HI) tests were carried out on sera from horses immunized against the Prague and Miami strains of equine influenza virus. The HI and NT tests demonstrated good sensitivity; the sensitivity of the SRH test was somewhat lower. The NT titers of individual sera were correlated very closely with the HI titers, although the NT titers were higher. SRH zone diameters of individual sera also showed significant correlat...

  15. Inhibition of P-Selectin and PSGL-1 Using Humanized Monoclonal Antibodies Increases the Sensitivity of Multiple Myeloma Cells to Bortezomib

    Directory of Open Access Journals (Sweden)

    Barbara Muz

    2015-01-01

    Full Text Available Multiple myeloma (MM is a plasma cell malignancy localized in the bone marrow. Despite the introduction of novel therapies majority of MM patients relapse. We have previously shown that inhibition of P-selectin and P-selectin glycoprotein ligand-1 (PSGL-1 play a key role in proliferation of MM and using small-molecule inhibitors of P-selectin/PSGL-1 sensitized MM cells to therapy. However, these small-molecule inhibitors had low specificity to P-selectin and showed poor pharmacokinetics. Therefore, we tested blocking of P-selectin and PSGL-1 using functional monoclonal antibodies in order to sensitize MM cells to therapy. We have demonstrated that inhibiting the interaction between MM cells and endothelial and stromal cells decreased proliferation in MM cells and in parallel induced loose-adhesion to the primary tumor site to facilitate egress. At the same time, blocking this interaction in vivo led to MM cells retention in the circulation and delayed homing to the bone marrow, thus exposing MM cells to bortezomib which contributed to reduced tumor growth and better mice survival. This study provides a better understanding of the biology of P-selectin and PSGL-1 and their roles in dissemination and resensitization of MM to treatment.

  16. High efficacy of anti DBL4e-VAR2CSA antibodies in inhibition of CSA-binding Plasmodium falciparum-infected erythrocytes from pregnant women

    DEFF Research Database (Denmark)

    Magistrado, Pamela A; Minja, Daniel; Doritchamou, Justin; Ndam, Nicaise Tuikue; John, Davis; Schmiegelow, Christentze; Massougbodji, Achille; Dahlbäck, Madeleine; Ditlev, Sisse B; Pinto, Vera V; Resende, Mafalda; Lusingu, John; Theander, Thor G; Salanti, Ali; Nielsen, Morten A

    2011-01-01

    Malaria during pregnancy is a major cause of intra-uterine growth-retardation and infant death in sub-Saharan Africa. Ideally, this could be prevented by a vaccine delivered before the first pregnancy. Antibodies against domain DBL4¿ from VAR2CSA has been shown to inhibit adhesion of laboratory...

  17. The use of homologous virus in the haemagglutination-inhibition assay after vaccination with Newcastle disease virus strain La Sota or clone30 leads to an over estimation of protective serum antibody titres

    NARCIS (Netherlands)

    Maas, R.A.; Oei, H.L.; Kemper, S.; Koch, G.; Visser, L.

    1998-01-01

    We evaluated the influence of the use of the Newcastle disease virus (NDV)-strains Ulster and La Sota in the haemagglutination inhibition (HI) assay for the measurement of antibody titres after NDV vaccination. The use of the homologous La Sota antigen in the HI assay after Clone30 and La Sota vacci

  18. Detection of Anaplasma antibodies in wildlife and domestic species in wildlife-livestock interface areas of Kenya by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay

    Directory of Open Access Journals (Sweden)

    J.J.N. Ngeranwa

    2008-09-01

    Full Text Available The seroprevalence of Anaplasma antibodies in wildlife (eland, blue wildebeest, kongoni, impala, Thomson's gazelle, Grant's gazelle, giraffe and plains zebra and domestic animal (cattle, sheep and goat populations was studied in wildlife / livestock interface areas of Kenya. Serum samples were analyzed by competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA, using a recombinant antigen (MSP-5 from Anaplasma marginale surface membrane. A monoclonal antibody, FC-16, was used as the primary antibody, while anti-mouse conjugated to horseradish peroxidase was used as the secondary antibody. The results indicate a high seroprevalence in both wildlife and livestock populations, in contrast to earlier reports from Kenya, which indicated a low seroprevalence. The differences are attributed to the accurate analytical method used (CI-ELISA, as compared with agglutination techniques, clinical signs and microscopy employed by the earlier workers.

  19. Detection of Anaplasma antibodies in wildlife and domestic species in wildlife-livestock interface areas of Kenya by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Ngeranwa, J J N; Shompole, S P; Venter, E H; Wambugu, A; Crafford, J E; Penzhorn, B L

    2008-09-01

    The seroprevalence of Anaplasma antibodies in wildlife (eland, blue wildebeest, kongoni, impala, Thomson's gazelle, Grant's gazelle, giraffe and plains zebra) and domestic animal (cattle, sheep and goat) populations was studied in wildlife/livestock interface areas of Kenya. Serum samples were analyzed by competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA), using a recombinant antigen (MSP-5) from Anaplasma marginale surface membrane. A monoclonal antibody, FC-16, was used as the primary antibody, while anti-mouse conjugated to horseradish peroxidase was used as the secondary antibody. The results indicate a high seroprevalence in both wildlife and livestock populations, in contrast to earlier reports from Kenya, which indicated a low seroprevalence. The differences are attributed to the accurate analytical method used (CI-ELISA), as compared with agglutination techniques, clinical signs and microscopy employed by the earlier workers. PMID:19040134

  20. Antibody-Mediated Inhibition of the FGFR1c Isoform Induces a Catabolic Lean State in Siberian Hamsters.

    Science.gov (United States)

    Samms, Ricardo J; Lewis, Jo E; Lory, Alex; Fowler, Maxine J; Cooper, Scott; Warner, Amy; Emmerson, Paul; Adams, Andrew C; Luckett, Jeni C; Perkins, Alan C; Wilson, Dana; Barrett, Perry; Tsintzas, Kostas; Ebling, Francis J P

    2015-11-16

    Hypothalamic tanycytes are considered to function as sensors of peripheral metabolism. To facilitate this role, they express a wide range of receptors, including fibroblast growth factor receptor 1 (FGFR1). Using a monoclonal antibody (IMC-H7) that selectively antagonizes the FGFR1c isoform, we investigated possible actions of FGFR1c in a natural animal model of adiposity, the Siberian hamster. Infusion of IMC-H7 into the third ventricle suppressed appetite and increased energy expenditure. Likewise, peripheral treatment with IMC-H7 decreased appetite and body weight and increased energy expenditure and fat oxidation. A greater reduction in body weight and caloric intake was observed in response to IMC-H7 during the long-day fat state as compared to the short-day lean state. This enhanced response to IMC-H7 was also observed in calorically restricted hamsters maintained in long days, suggesting that it is the central photoperiodic state rather than the peripheral adiposity that determines the response to FGFR1c antagonism. Hypothalamic thyroid hormone availability is controlled by deiodinase enzymes (DIO2 and DIO3) expressed in tanycytes and is the key regulator of seasonal cycles of energy balance. Therefore, we determined the effect of IMC-H7 on hypothalamic expression of these deiodinase enzymes. The reductions in food intake and body weight were always associated with decreased expression of DIO2 in the hypothalamic ependymal cell layer containing tanycytes. These data provide further support for the notion the tanycytes are an important component of the mechanism by which the hypothalamus integrates central and peripheral signals to regulate energy intake and expenditure. PMID:26549257

  1. Anti-lipid phosphate phosphohydrolase-3 (LPP3 antibody inhibits bFGF- and VEGF-induced capillary morphogenesis of endothelial cells

    Directory of Open Access Journals (Sweden)

    Humtsoe Joseph O

    2005-08-01

    Full Text Available Abstract Background Angiogenesis, or the remodeling of existing vasculature serves as a lifeline to nourish developing embryos and starved tissues, and to accelerate wound healing, diabetic retinopathy, and tumor progression. Recent studies indicate that angiogenesis requires growth factor activity as well as cell adhesion events mediated by α5β1 and αvβ3 integrins. We previously demonstrated that human lipid phosphate phosphohydrolase-3 (LPP3 acts as a cell-associated ligand for α5β1 and αvβ3 integrins. Here, we test the hypothesis that an anti-LPP3 antibody can inhibit basic fibroblast growth factor (bFGF-and vascular endothelial growth factor (VEGF-induced capillary morphogenesis of endothelial cells (ECs. Results We report that bFGF and VEGF up-regulate LPP3 protein expression in ECs. Immunoprecipitation analyses show that LPP3 is a cell surface protein and undergoes N-glycosylation. Fluorescent activated cell sorting (FACS data suggest that anti-LPP3-RGD detects native neoepitope on the surface of activated ECs. Moreover, we demonstrate LPP3 protein expression in tumor endothelium alongside VEGF. The embedding of ECs into three-dimensional type I collagen in the presence of bFGF and VEGF induce capillary formation. Importantly, we show that the addition of an anti-LPP3 antibody specifically and significantly blocks bFGF- and VEGF-induced capillary morphogenesis of ECs. Conclusion These data suggest that activated ECs as well as tumor endothelium express LPP3 protein. In an in vitro assay, the anti-LPP3-RGD specifically blocks bFGF and VEGF induced capillary morphogenesis of ECs. Our results, therefore, suggest a role for LPP3 in angiogenesis.

  2. Thyroid Antibodies

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Thyroid Antibodies Share this page: Was this page helpful? Also known as: Thyroid Autoantibodies; Antithyroid Antibodies; Antimicrosomal Antibody; Thyroid Microsomal Antibody; ...

  3. Antibodies against the C-terminal peptide of rabbit oviductin inhibit mouse early embryo development to pass 2-cell stage

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A full-length rabbit oviductin cDNA(1909bp) was cloned. It consists of a 5'-UTR of 52bp, an open reading frame (ORF) of 1374bp and a 3'-UTR of 483bp and has more than 80% homology with that of other mammal oviductins. N-terminal peptide (NTP) (384 residues) and C-terminal peptide (CTP)(73 residues) of deduced protein precursor has about 80% and 50% identity with that of other mammals respectively. Fusion proteins GST-NTP 368(1R-368N)and GST-CTP73 (369F-441A) were expressed and purified. NH2-terminal of CTP sequencing reveals that the purified protein is consistent with the deduced one. In order to study the function of NTP and CTP the mouse anti-NTP and rabbit anti-CTP antisera were prepared. Tissue-specific (skeleton muscle, oviduct, uterus, ovary, liver, heart and brain) analysis indicated that rabbit oviductin was only found in oviduct. The conditioned medium derived from the rabbit oviduct mucosa epithelial cells has a function of overcoming the early embryonic development block of Kunming mouse cultured in vitro. Anti-CTP antiserum could totally inhibit the early embryo development at 2-cell stage cultured in the conditioned culture medium, but anti-NTP antiserum couldn't. There was a positive relationship between the ratio of early embryos at development block and the dosage of anti-CTP antiserum added in the conditioned culture medium. These results suggest that oviductin has a function not only on fertilization, but also on the release of early embryonic development block, and the later function domain of rabbit oviductin may be situate in its C-terminal.

  4. Relationship between haemagglutination-inhibiting antibody titres and clinical protection against influenza: development and application of a bayesian random-effects model

    Directory of Open Access Journals (Sweden)

    Megas Françoise

    2010-03-01

    Full Text Available Abstract Background Antibodies directed against haemagglutinin, measured by the haemagglutination inhibition (HI assay are essential to protective immunity against influenza infection. An HI titre of 1:40 is generally accepted to correspond to a 50% reduction in the risk of contracting influenza in a susceptible population, but limited attempts have been made to further quantify the association between HI titre and protective efficacy. Methods We present a model, using a meta-analytical approach, that estimates the level of clinical protection against influenza at any HI titre level. Source data were derived from a systematic literature review that identified 15 studies, representing a total of 5899 adult subjects and 1304 influenza cases with interval-censored information on HI titre. The parameters of the relationship between HI titre and clinical protection were estimated using Bayesian inference with a consideration of random effects and censorship in the available information. Results A significant and positive relationship between HI titre and clinical protection against influenza was observed in all tested models. This relationship was found to be similar irrespective of the type of viral strain (A or B and the vaccination status of the individuals. Conclusion Although limitations in the data used should not be overlooked, the relationship derived in this analysis provides a means to predict the efficacy of inactivated influenza vaccines when only immunogenicity data are available. This relationship can also be useful for comparing the efficacy of different influenza vaccines based on their immunological profile.

  5. ING-1(heMAb, a Monoclonal Antibody to Epithelial Cell Adhesion Molecule, Inhibits Tumor Metastases in a Murine Cancer Model

    Directory of Open Access Journals (Sweden)

    Harry H. Ruan

    2003-11-01

    Full Text Available ING-1(heMAb, a human-engineered monoclonal antibody (MAb that specifically targets the epithelial cell adhesion molecule (Ep-CAM, kills adenocarcinoma cells in vitro and inhibits tumor growth in vivo. In the current study, we evaluated the efficacy of ING-1(heMAb in a murine model of cancer metastases. Mice received intravenous dosing of 1 mg/kg ING-1(heMAb, twice a week, starting on day 2 or day 5. A negative control group received 1 mg/kg human immunoglobulin G with the same dose frequency starting on day 2. A positive control group received weekly 100 mg/kg 54lurouracil/leucovorin starting on day 2. ING-1(heMAb/day 2 treatment significantly reduced both the number of visible tumor nodules in body cavities (P < .01 and the number of metastases on lung surfaces (P < .005. The treatment also resulted in a 91% reduction of micrometastases in lung tissues (P <.0001. Delaying ING-1(heMAb treatment until day 5 caused 54% reduction in micrometastases (P <.005. Our results indicate that a number of parameters, including treatment starting day, dose level, and dose frequency, are critical in achieving the optimal efficacy of ING-1(heMAb. We conclude that ING-1(heMAb effectively reduced tumor metastases in a murine cancer model. Immunotherapy with ING-1(heMAb may be beneficial in treating human metastatic diseases.

  6. Evaluation of enzyme-linked immunosorbent assays and a haemagglutination inhibition tests for the detection of antibodies to Newcastle disease virus in village chickens using a Bayesian approach.

    Science.gov (United States)

    Chaka, H; Thompson, P N; Goutard, F; Grosbois, V

    2015-04-01

    Newcastle disease (ND) is an endemic disease in village chickens in Ethiopia with substantial economic importance. The sensitivity (Se) and specificity (Sp) of a blocking enzyme-linked immunosorbent assay (bELISA, Svanova Biotech), indirect ELISA (iELISA, Laboratoire Service International) and haemagglutination inhibition (HI) test for ND virus (NDV) antibody detection were evaluated in a Bayesian framework in the absence of a gold standard test, on sera collected from unvaccinated chickens kept under the village production system in household flocks and at markets in two woredas (i.e. districts) of the Eastern Shewa zone, Ethiopia. The outcomes of the iELISA test differed dramatically from those of the two other tests with 92% of the samples testing positive as compared with less than 15% for bELISA and HI. iELISA results were also inconsistent with previous estimations of Newcastle serological prevalence. The information provided by the iELISA test was thus considered as highly unreliable, probably due to an extremely low specificity, and thus not considered in the Bayesian models aiming at estimating serological prevalence and test performance parameters. Bayesian modelling of HI and bELISA test results suggested that bELISA had both the highest Se (86.6%; 95% posterior credible interval (PCI): 61.8%; 98.5%), and the highest Sp (98.3%; 95% PCI: 97.2%; 99.5%), while HI had a Se of 80.2% (95% PCI: 59.1%; 94.3%), and a Sp of 96.1% (95% PCI: 95.1%; 97.4%). Model selection and the range of the posterior distribution of the correlation between bELISA and HI test outcomes for truly seropositive animals (median at 0.461; PCI: -0.055; 0.894) suggested a tendency for bELISA and HI to detect the same truly positive animals and to fail to detect the same truly positive animals. The use of bELISA in screening and surveillance for NDV antibodies is indicated given its high Se and Sp, in addition to its ease of automation to handle large numbers of samples compared to HI. The

  7. Inhibition of phagocytosis of complement C3- or immunoglobulin G-coated particles and of C3bi binding by monoclonal antibodies to a monocyte-granulocyte membrane glycoprotein (Mol).

    OpenAIRE

    Arnaout, M. A.; Todd, R F; Dana, N; Melamed, J; Schlossman, S F; Colten, H R

    1983-01-01

    Events that lead to phagocytosis of complement (C3)- or IgG-coated particles after their interaction with specific cell surface receptors are poorly understood. Two mouse monoclonal antibodies (an IgM and an IgG2a) to a human granulocyte-monocyte surface membrane differentiation antigen (Mol) inhibited ingestion by granulocytes both of oil Red O particles opsonized with normal human serum or with IgG and of sheep erythrocytes sensitized with IgG. In addition, they specifically inhibited roset...

  8. The NTS-DBL2X region of VAR2CSA Induces cross-reactive antibodies that inhibit adhesion of several Plasmodium falciparum isolates to chondroitin sulfate A

    DEFF Research Database (Denmark)

    Bigey, Pascal; Gnidehou, Sédami; Doritchamou, Justin;

    2011-01-01

    -adapted parasite lines and field isolates expressing VAR2CSA. Competition enzyme-linked immunosorbent assay (ELISA) was employed to analyze functional resemblance between antibodies induced in animals and those naturally acquired by immune multigravidae. Results. Antibodies targeting the N-terminal sequence (NTS......) up to DBL2X (NTS-DBL2X) efficiently blocked parasite adhesion to chondroitin sulfate A in a manner similar to that of antibodies raised against the entire VAR2CSA extracellular domain. Interestingly, naturally acquired antibodies and those induced by vaccination against NTS-DBL2X target overlapping...

  9. A novel trifunctional IgG-like bispecific antibody to inhibit HIV-1 infection and enhance lysis of HIV by targeting activation of complement

    Directory of Open Access Journals (Sweden)

    Tomlinson Stephen

    2010-06-01

    Full Text Available Abstract Background The complement system is not only a key component of innate immunity but also provides a first line of defense against invading pathogens, especially for viral pathogens. Human immunodeficiency virus (HIV, however, possesses several mechanisms to evade complement-mediated lysis (CoML and exploit the complement system to enhance viral infectivity. Responsible for this intrinsic resistance against complement-mediated virolysis are complement regulatory membrane proteins derived from the host cell that inherently downregulates complement activation at several stages of the cascade. In addition, HIV is protected from complement-mediated lysis by binding soluble factor H (fH through the viral envelope proteins, gp120 and gp41. Whereas inhibition of complement activity is the desired outcome in the vast majority of therapeutic approaches, there is a broader potential for complement-mediated inhibition of HIV by complement local stimulation. Presentation of the hypothesis Our previous studies have proven that the complement-mediated antibody-dependent enhancement of HIV infection is mediated by the association of complement receptor type 2 bound to the C3 fragment and deposited on the surface of HIV virions. Thus, we hypothesize that another new activator of complement, consisting of two dsFv (against gp120 and against C3d respectively linked to a complement-activating human IgG1 Fc domain ((anti-gp120 × anti-C3d-Fc, can not only target and amplify complement activation on HIV virions for enhancing the efficiency of HIV lysis, but also reduce the infectivity of HIV through blocking the gp120 and C3d on the surface of HIV. Testing the hypothesis Our hypothesis was tested using cell-free HIV-1 virions cultivated in vitro and assessment of virus opsonization was performed by incubating appropriate dilutions of virus with medium containing normal human serum and purified (anti-gp120 × anti-C3d-Fc proteins. As a control group, viruses

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

    Science.gov (United States)

    Prado, Nidiane D. R.; Pereira, Soraya S.; da Silva, Michele P.; Morais, Michelle S. S.; Kayano, Anderson M.; Moreira-Dill, Leandro S.; Luiz, Marcos B.; Zanchi, Fernando B.; Fuly, André L.; E. F. Huacca, Maribel; Fernandes, Cleberson F.; Calderon, Leonardo A.; Zuliani, Juliana P.; Soares, Andreimar M.; Stabeli, Rodrigo G.; F. C. Fernandes, Carla

    2016-01-01

    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. PMID:27028872

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

    Science.gov (United States)

    Prado, Nidiane D R; Pereira, Soraya S; da Silva, Michele P; Morais, Michelle S S; Kayano, Anderson M; Moreira-Dill, Leandro S; Luiz, Marcos B; Zanchi, Fernando B; Fuly, André L; E F Huacca, Maribel; Fernandes, Cleberson F; Calderon, Leonardo A; Zuliani, Juliana P; Pereira da Silva, Luiz H; Soares, Andreimar M; Stabeli, Rodrigo G; F C Fernandes, Carla

    2016-01-01

    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. PMID:27028872

  12. 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.

  13. Antibody to E1 peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to HepG2 cells in vitro

    OpenAIRE

    El-Awady, Mostafa K.; Tabll, Ashraf A.; Atef, Khaled; Yousef, Samar S; Omran, Moataza H; El-Abd, Yasmin; Bader-Eldin, Noha G; Salem, Ahmad M; Zohny, Samir F; El-Garf, Wael T

    2006-01-01

    AIM: To analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus (HCV). Specific polyclonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of HCV and was shown to be highly conserved among HCV published genotypes.

  14. Participation of L3T4 in T cell activation in the absence of class II major histocompatibility complex antigens. Inhibition by anti-L3T4 antibodies is a function both of epitope density and mode of presentation of anti-receptor antibody

    DEFF Research Database (Denmark)

    Owens, T; Fazekas de St Groth, B

    1987-01-01

    activation in the complete absence of class II MHC, immobilized antibody (either Sepharose-coupled or plastic-adsorbed) being more effective. The induction of IL 3 production by suboptimal doses of either Con A or plastic-adsorbed F23.1 was inhibited by the anti-L3T4 antibody GK1.5, as was the response to F...... of T cell/antigen interactions. By using antibodies against the T cell antigen receptor (TCR) to activate T cells, thereby circumventing the requirement for antigen presenting cells and MHC-associated antigen, we have been able to study the function of L3T4 in the absence of class II MHC. We have...... used two monoclonal antibodies, KJ16-133.18 and F23.1, that recognize a determinant encoded by the T cell receptor V beta 8 gene family. These antibodies were used to select two clones of T cells with surface phenotype Thy-1.2+, L3T4+, Lyt-2-, KJ16-133.18+, F23.1+, IA-, IE-. One of these clones (E9.D4...

  15. Lysine at position 222 of the goat prion protein inhibits the binding of monoclonal antibody F99/97.6.1.

    Science.gov (United States)

    Mazza, Maria; Guglielmetti, Chiara; Pagano, Marianna; Sciuto, Simona; Ingravalle, Francesco; Martucci, Francesca; Caramelli, Maria; Acutis, Pier Luigi

    2012-09-01

    Prion protein (PrP) is encoded by the PRNP gene, which is highly polymorphic in goats, with polymorphisms encoding amino acid substitutions at the protein level. In the current study, the reactivity of monoclonal antibody (mAb) F99/97.6.1 in binding PrP from goats polymorphic at PRNP codon 222 was investigated. Nervous tissue from 30 scrapie-negative goats with 3 different genotypes (222Q/Q, 222Q/K, and 222K/K) was analyzed by Western blot using mAbs P4 and F99/97.6.1. Although PrP was detected in all 30 samples by mAb P4, detection of PrP by mAb F99/97.6.1 was limited to 222Q/Q (12/12). No PrP was detected by mAb F99/97.6.1 in the 222K/K samples (n = 6), and the signal intensity of mAb F99/97.6.1 for PrP was lower for the 222Q/K samples (12/12 samples). To further investigate these results, additional Western blot analyses were performed, and the PrP signals detected by mAbs F99/97.6.1 and SAF84 were then quantified. The mean F99/SAF84 ratio (± standard deviation) calculated for the 222Q/Q group was 0.73 ± 1.26, and the mean for the 222Q/K group was 0.27 ± 1.31. Statistical analysis of these values evidenced statistically significant differences between the 222Q/Q and 222Q/K samples. The results of the study thus revealed an inhibition by lysine at position 222 on the binding of mAb F99/97.6.1 to goat PrP. This has implications for the use of mAb F99/97.6.1 for diagnostic purposes. Because the 222K allele could be a target for genetic selection in goats, the differential reactivity of mAb F99/97.6.1 could be exploited with a genotyping test setup. PMID:22914824

  16. Monoclonal Antibodies to Conformational Epitopes of the Surface Glycoprotein of Caprine Arthritis-Encephalitis Virus: Potential Application to Competitive-Inhibition Enzyme-Linked Immunosorbent Assay for Detecting Antibodies in Goat Sera

    OpenAIRE

    Özyörük, Fuat; Cheevers, William P.; Hullinger, Gordon A.; McGuire, Travis C.; Hutton, Melinda; Knowles, Donald P

    2001-01-01

    Four immunoglobulin G1 monoclonal antibodies (MAbs) to the gp135 surface envelope glycoprotein (SU) of the 79–63 isolate of caprine arthritis-encephalitis virus (CAEV), referred to as CAEV-63, were characterized and evaluated for their ability to compete with antibody from CAEV-infected goats. Three murine MAbs (MAbs GPB16A, 29A, and 74A) and one caprine MAb (MAb F7-299) were examined. All MAbs reacted in nitrocellulose dot blots with native CAEV-63 SU purified by MAb F7-299 affinity chromato...

  17. Antibody of predetermined specificity to a carboxy-terminal region of H-ras gene products inhibits their guanine nucleotide-binding function.

    OpenAIRE

    Srivastava, S. K.; Lacal, J C; Reynolds, S.H.; Aaronson, S A

    1985-01-01

    The high prevalence of ras oncogenes in human tumors has given increasing impetus to efforts aimed at elucidating the structure and function of their p21 products. To identify functionally important domains of the p21 protein, antibodies were generated against synthetic peptides corresponding to various regions of the protein. Antibodies directed against a synthetic peptide fragment corresponding to amino acid residues 161 to 176 in the carboxy-terminal region of the H-ras-encoded p21 molecul...

  18. Functional effects of anticardiolipin antibodies.

    Science.gov (United States)

    Harris, E N; Pierangeli, S S

    1996-10-01

    The 'lupus anticoagulant' phenomenon is the best documented functional effect of antiphospholipid (aPL) antibodies, occurring either by inhibition of the prothrombinase and/or Factor X activation reactions. Understanding the mechanism by which aPL antibodies inhibit phospholipid dependent coagulation reactions may yield important clues about their 'thrombogenic effects' in vivo. We conducted a series of studies to determine the specificity, diversity, and mechanism by which aPL antibodies inhibit phospholipid dependent reactions. Results showed that purified immunoglobulins with lupus anticoagulant and anti-cardiolipin activities were absorbed by negatively charged phospholipids and both activities were recovered from the phospholipid-antibody precipitate. Purified aPL antibodies inhibited the prothrombinase reaction in a plasma free system in which beta 2-glycoprotein 1 (beta 2-GP1) was absent. Affinity purified aPL antibodies had 25-50 times the inhibitory activity of immunoglobulin preparations. The phospholipid binding proteins, beta 2-GPI and placental anticoagulant protein I (PAP I), independently inhibited the prothrombinase reaction, and when these proteins were combined with aPL, inhibition of the prothrombinase reaction was additive. Antibodies of syphilis had no inhibitory effect, partially accounted for by lack of specificity for phosphotidylserine (PS). Although aPL antibodies inhibited the protein C activation reaction, there was no correlation of these activities with inhibition of the prothrombinase reaction. Together, these results show that aPL exert their effects by interaction with negatively charged phospholipids, in particular phosphotidylserine, but lack of correlation between inhibition of the prothrombinase and protein C activation reactions, suggests that the nature of the coagulation protein is also important. PMID:8902763

  19. Single-chain antibody-based gene therapy: Inhibition of tumor growth by in situ production of phage-derived antibodies blocking functionally active sites of cell-associated matrices

    DEFF Research Database (Denmark)

    Sanz, Laura; Kristensen, Peter; Blanco, Belén;

    2002-01-01

    Experimental evidence suggests that blocking the interactions between endothelial cells and extracellular matrix (ECM) components may provide a potent and general strategy to inhibit tumor neovascularization. Based on these considerations, we have focused our efforts on laminin, component of the ...

  20. 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 to an increased risk ...

  1. Inhibition of human immunodeficiency virus (HIV) infection in vitro by anticarbohydrate monoclonal antibodies: peripheral glycosylation of HIV envelope glycoprotein gp120 may be a target for virus neutralization

    DEFF Research Database (Denmark)

    Hansen, J E; Clausen, H; Nielsen, C;

    1990-01-01

    - and O-linked carbohydrate epitopes (LeY, A1, and sialyl-Tn) were able to block infection by cell-free virus as well as inhibit syncytium formation. Inhibition of virus infectivity was independent of virus strain (HTLVIIIB or patient isolate SSI-002), the cell line used for virus propagation (H9 or MT4...

  2. The potential role of functional inhibition of T regulatory cells by anti-TGFβ antibody in photodynamic therapy of renal cancer

    Science.gov (United States)

    Mroz, Pawel; Hamblin, Michael R.

    2011-03-01

    Photodynamic therapy (PDT) has been shown to be an effective locally ablative anti-cancer treatment that has the additional advantage of inducing tumor-directed immune response. We hypothesized that PDT could be combined with anti-transforming growth factor (TGF) beta antibody that does not significantly affect the population of cytotoxic T lymphocytes (CTL) but at the same time, has the potential to decrease the immunosuppressive effects of regulatory T-cells (Treg) mediated by TGF beta. This hypothesis was tested with aTGF-beta antibody combined with BPD-mediated PDT in a BALB/c renal cell carcinoma model. Evidence of positive benefits of the combination therapy over individual treatments alone was obtained.

  3. Broad-Spectrum Inhibition of HIV-1 by a Monoclonal Antibody Directed against a gp120-Induced Epitope of CD4

    OpenAIRE

    Burastero, Samuele E.; Frigerio, Barbara; Lopalco, Lucia; Sironi, Francesca; Breda, Daniela; Longhi, Renato; Scarlatti, Gabriella; Canevari, Silvana; Figini, Mariangela; Lusso, Paolo

    2011-01-01

    To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to conta...

  4. VIRAL ANTIBODIES IN PRESCHOOL CHILDREN

    Directory of Open Access Journals (Sweden)

    S. Saidi

    1974-08-01

    Full Text Available One hundred sera from children 1 - 6 years of age, representative of a large serum collection, were tested for the prevalence of antibodies against different viruses. Hemagglutination-inhibition (HI antibodies were found in 68% for measles; 61 % for rubella; 75'% for influenza A2/Hong Kong/68, 16% for influenza B/Md./59, 0% for group A arboviruses, 10% for group B arboviruses, 3% for phlebotomus fever group and 4% for Congo-Crimean hemorrhagic fever (C-CHF group of arboviruses Poliomyelitis-neutralizing antibodies for type 1, 2 and 3 were 90%; 85% and 84%~ respectively. Antibody to EH virus was detected in 84% of the sera by immuno-fluorescence. None of the sera were positive for hepatitis-B antigen or antibody by immuno-precipitation test. The prevalence of some viral antibodies found in this survey are compared with results obtained from surveys in other parts of the country.

  5. Structural basis of LaDR5, a novel agonistic anti-death receptor 5 (DR5 monoclonal antibody, to inhibit DR5/TRAIL complex formation

    Directory of Open Access Journals (Sweden)

    Qiao Chunxia

    2012-07-01

    Full Text Available Abstract Background As a member of the TNF superfamily, TRAIL could induce human tumor cell apoptosis through its cognate death receptors DR4 or DR5, which can induce formation of the death inducing signaling complex (DISC and activation of the membrane proximal caspases (caspase-8 or caspase-10 and mitochondrial pathway. Some monoclonal antibodies against DR4 or DR5 have been reported to have anti-tumor activity. Results In this study, we reported a novel mouse anti-human DR5 monoclonal antibody, named as LaDR5, which could compete with TRAIL to bind DR5 and induce the apoptosis of Jurkat cells in the absence of second cross-linking in vitro. Using computer-guided molecular modeling method, the 3-D structure of LaDR5 Fv fragment was constructed. According to the crystal structure of DR5, the 3-D complex structure of DR5 and LaDR5 was modeled using molecular docking method. Based on distance geometry method and intermolecular hydrogen bonding analysis, the key functional domain in DR5 was predicted and the DR5 mutants were designed. And then, three mutants of DR5 was expressed in prokaryotic system and purified by affinity chromatograph to determine the epitope of DR5 identified by LaDR5, which was consistent with the theoretical results of computer-aided analysis. Conclusions Our results demonstrated the specific epitope located in DR5 that plays a crucial role in antibody binding and even antineoplastic bioactivity. Meanwhile, revealed structural features of DR5 may be important to design or screen novel drugs agonist DR5.

  6. Toxic Shock Syndrome Toxin-1-Mediated Toxicity Inhibited by Neutralizing Antibodies Late in the Course of Continual in Vivo and in Vitro Exposure

    Directory of Open Access Journals (Sweden)

    Norbert Stich

    2014-05-01

    Full Text Available Toxic shock syndrome (TSS results from the host’s overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs. There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1 neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation, determination of IL-2 release in the cell supernatant (ELISA, and IL-2 gene activation (real-time PCR (RT-PCR. Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure.

  7. Blockade of the interleukin-2 receptor by anti-Tac antibody inhibits the generation of antigen-nonspecific suppressor T cells in vitro.

    OpenAIRE

    Oh-Ishi, T; Goldman, C K; Misiti, J; Waldmann, T. A.

    1988-01-01

    The role of interleukin 2 (IL-2) in the activation of suppressor T cells was investigated by using the monoclonal antibody anti-Tac, which blocks the binding of IL-2 to the 55-kDa peptide of the high-affinity IL-2 receptor. Anti-Tac was added to an antigen-nonspecific suppressor system in which Con A-induced suppressor T cells were generated during a preculture period, and their effects on immunoglobulin production were assessed in second, indicator cultures containing pokeweed mitogen and pe...

  8. Antibody to Heat Shock Protein 70 (HSP70) Inhibits Human T-Cell Lymphoptropic Virus Type I (HTLV-I) Production by Transformed Rabbit T-Cell Lines

    OpenAIRE

    Hanan Fallouh; Wahib Mahana

    2012-01-01

    Adult T cell leukemia is a fatal malignant transformation caused by the human T-cell lymphoptropic virus type I (HTLV-I). HTLV-I is only associated with the development of this disease in a small percentage of infected individuals. Using two rabbit transformed T-cell lines; RH/K30 (asymptomatic) and RH/K34 (leukemogenic), we have investigated the expression of heat shock proteins (HSP) 90 and 70 and the role of anti-HSPs antibodies on virus production. HSPs surface expression was higher on RH...

  9. Uses of monoclonal antibody 8H9

    Science.gov (United States)

    Cheung, Nai-Kong V.

    2013-04-09

    This invention provides a composition comprising an effective amount of monoclonal antibody 8H9 or a derivative thereof and a suitable carrier. This invention provides a pharmaceutical composition comprising an effective amount of monoclonal antibody 8H9 or a derivative thereof and a pharmaceutically acceptable carrier. This invention also provides an antibody other than the monoclonal antibody 8H9 comprising the complementary determining regions of monoclonal antibody 8H9 or a derivative thereof, capable of binding to the same antigen as the monoclonal antibody 8H9. This invention provides a substance capable of competitively inhibiting the binding of monoclonal antibody 8H9. This invention also provides an isolated scFv of monoclonal antibody 8H9 or a derivative thereof. This invention also provides the 8H9 antigen. This invention also provides different uses of the monoclonal antibody 8H9 or its derivative.

  10. Inhibition of human tumor xenograft growth in nude mice by a conjugate of monoclonal antibody LA22 to epidermal growth factor receptor with anti-tumor antibiotics mitomycin C

    International Nuclear Information System (INIS)

    Anti-EGFR monoclonal antibodies LA22 and Erbitux bind to different epitopes of EGFR. The chemimmunoconjugates of MMC with LA22 or Erbitux were prepared, and in vitro cytotoxicity assays with A549 cells showed that LA22-MMC was much more potent than Erbitux or Erbitux-MMC. Viabilities of A549 cells treated with LA22-MMC, Erbitux or Erbitux-MMC were 35%, 94%, and 81%, respectively. Immunoscintigraphy of xenografts of human A431 and A549 cells in nude mice both showed that 125I-labeled-LA22-MMC enriched in tumor sites prominently. Most importantly, in vivo assays showed LA22-MMC was significantly more effective than free drug MMC in the treatment of subcutaneous xenografts of human A431 cells in nude mice (83% inhibition for LA22-MMC and 30% for MMC). We concluded that LA22-MMC could be a very potent drug for treatment of solid tumors

  11. CCR5 antibodies HGS004 and HGS101 preferentially inhibit drug-bound CCR5 infection and restore drug sensitivity of Maraviroc-resistant HIV-1 in primary cells

    International Nuclear Information System (INIS)

    R5 HIV-1 strains resistant to the CCR5 antagonist Maraviroc (MVC) can use drug-bound CCR5. We demonstrate that MVC-resistant HIV-1 exhibits delayed kinetics of coreceptor engagement and fusion during drug-bound versus free CCR5 infection of cell lines. Antibodies directed against the second extracellular loop (ECL2) of CCR5 had greater antiviral activity against MVC-bound compared to MVC-free CCR5 infection. However, in PBMCs, only ECL2 CCR5 antibodies HGS004 and HGS101, but not 2D7, inhibited infection by MVC resistant HIV-1 more potently with MVC-bound than with free CCR5. In addition, HGS004 and HGS101, but not 2D7, restored the antiviral activity of MVC against resistant virus in PBMCs. In flow cytometric studies, CCR5 binding by the HGS mAbs, but not by 2D7, was increased when PBMCs were treated with MVC, suggesting MVC increases exposure of the relevant epitope. Thus, HGS004 and HGS101 have antiviral mechanisms distinct from 2D7 and could help overcome MVC resistance.

  12. Monoclonal Antibody 16D10 to the C-Terminal Domain of the Feto-Acinar Pancreatic Protein Binds to Membrane of Human Pancreatic Tumoral SOJ-6 Cells and Inhibits the Growth of Tumor Xenografts

    Directory of Open Access Journals (Sweden)

    Laurence Panicot-Dubois

    2004-11-01

    Full Text Available Feto-acinar pancreatic protein (FAPP characterized by mAbJ28 reactivity is a specific component associated with ontogenesis and behaves as an oncodevelopment-associated antigen. We attempted to determine whether pancreatic tumoral SOJ-6 cells are expressed at their surface FAPP antigens and to examine if specific antibodies directed against these FAPP epitopes could decrease the growth of pancreatic tumors in a mice model. For this purpose, we used specific antibodies against either the whole FAPP, the O-glycosylated C-terminal domain, or the N-terminal domain of the protein. Our results indicate that SOJ-6 cells expressed at their surface a 32-kDa peptide corresponding to the C-terminal domain of the FAPP. Furthermore, we show, by using endoproteinase Lys-C or geldanamycin, a drug able to impair the FAPP secretion, that this 32-kDa peptide expressed on the SOJ-6 cell surface comes from the degradation of the FAPP. Finally, an in vivo prospective study using a preventative tumor model in nude mice indicates that targeting this peptide by the use of mAb16D10 inhibits the growth of SOJ-6 xenografts. The specificity of mAb16D10 for pancreatic tumors and the possibility to obtain recombinant structures of mucin-like peptides recognized by mAb16D10 and mAbJ28 are promising tools in immunologic approaches to cure pancreatic cancers.

  13. Inhibition of IL-10 production by maternal antibodies against Group B Streptococcus GAPDH confers immunity to offspring by favoring neutrophil recruitment.

    Directory of Open Access Journals (Sweden)

    Pedro Madureira

    2011-11-01

    Full Text Available Group B Streptococcus (GBS is the leading cause of neonatal pneumonia, septicemia, and meningitis. We have previously shown that in adult mice GBS glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH is an extracellular virulence factor that induces production of the immunosuppressive cytokine interleukin-10 (IL-10 by the host early upon bacterial infection. Here, we investigate whether immunity to neonatal GBS infection could be achieved through maternal vaccination against bacterial GAPDH. Female BALB/c mice were immunized with rGAPDH and the progeny was infected with a lethal inoculum of GBS strains. Neonatal mice born from mothers immunized with rGAPDH were protected against infection with GBS strains, including the ST-17 highly virulent clone. A similar protective effect was observed in newborns passively immunized with anti-rGAPDH IgG antibodies, or F(ab'(2 fragments, indicating that protection achieved with rGAPDH vaccination is independent of opsonophagocytic killing of bacteria. Protection against lethal GBS infection through rGAPDH maternal vaccination was due to neutralization of IL-10 production soon after infection. Consequently, IL-10 deficient (IL-10(-/- mice pups were as resistant to GBS infection as pups born from vaccinated mothers. We observed that protection was correlated with increased neutrophil trafficking to infected organs. Thus, anti-rGAPDH or anti-IL-10R treatment of mice pups before GBS infection resulted in increased neutrophil numbers and lower bacterial load in infected organs, as compared to newborn mice treated with the respective control antibodies. We showed that mothers immunized with rGAPDH produce neutralizing antibodies that are sufficient to decrease IL-10 production and induce neutrophil recruitment into infected tissues in newborn mice. These results uncover a novel mechanism for GBS virulence in a neonatal host that could be neutralized by vaccination or immunotherapy. As GBS GAPDH is a

  14. Inhibition of subcutaneous growth of Ehrlich Ascites Carcinoma (EAC) tumor by post-immunization with EAC-cell gangliosides and its anti-idiotype antibody in relation to tumor angiogenesis, apoptosis, cell cycle and infiltration of CD4+, CD8+ lymphocytes, NK cells, suppressor cells and APC-cells in tumor

    International Nuclear Information System (INIS)

    Both EAC-tumor associated gangliosides and its anti-idiotype antibody inhibited growth of this tumor significantly. Immuno-histological studies with von Willebrand Factor (vWF) antibody indicated that tumor angiogenesis as determined by expression of vWF decreased in tumors of mice, post-immunized with EAC-cell gangliosides as well as its anti-idiotype antibody. Infiltration of various immune cells of the host in the tumor correlated to some extent with tumor-growth inhibition. Apoptosis study using AnnexinV-FITC and propidium iodide indicated that tumor growth inhibition in mice post-immunized with EAC-gangliosides and its anti-idiotype antibody were due to enhanced apoptosis and cell death. Cell cycle analysis by FACS indicated that EAC-cell associated gangliosides and its anti-idiotype antibody were acting both at the M2 i.e. S and M3 i.e. G2/M phases of the cell cycle to arrest tumor growth. (author)

  15. Anti-EphA2 Antibodies Decrease EphA2 Protein Levels in Murine CT26 Colorectal and Human MDA-231 Breast Tumors But Do Not Inhibit Tumor Growth

    Directory of Open Access Journals (Sweden)

    David Kiewlich

    2006-01-01

    Full Text Available The EphA2 receptor tyrosine kinase has been shown to be over-expressed in cancer and a monoclonal antibody (mAb that activates and down-modulates EphA2 was reported to inhibit the growth of human breast and lung tumor xenografts in nude mice. Reduction of EphA2 levels by treatment with anti-EphA2 siRNA also inhibited tumor growth, suggesting that the anti-tumor effects of these agents are mediated by decreasing the levels of EphA2. As these studies employed human tumor xenograft models in nude mice with reagents whose crossreactivity with murine EphA2 is unknown, we generated a mAb (Ab20 that preferentially binds, activates, and induces the degradation of murine EphA2. Treatment of established murine CT26 colorectal tumors with Ab20 reduced EphA2 protein levels to ~12% of control tumor levels, yet had no effect on tumor growth. CT26 tumor cell colonization of the lung was also not affected by Ab20 administration despite having barely detectable levels of EphA2. We also generated and tested a potent agonistic mAb against human EphA2 (1G9-H7. No inhibition of human MDA-231 breast tumor xenograft growth was observed despite evidence for >85% reduction of EphA2 protein levels in the tumors. These results suggest that molecular characteristics of the tumors in addition to EphA2 over-expression may be important for predicting responsiveness to EphA2-directed therapies.

  16. Simplified fluorescent inhibition microtest for the titration of rabies neutralizing antibodies Microteste de inibição de fluorescência simplificado para titulação de anticorpos antirábicos

    Directory of Open Access Journals (Sweden)

    S.R. Favoretto

    1993-04-01

    Full Text Available A simplified fluorescence inhibition microtest (SFIMT was standardized for the evaluation of antirabies serum neutralizing antibodies based on the rapid fluorescent focus inhibition test (RFFIT and the fluorescence inhibition microtest (FIMT. The simplified test showed reproductibility similar to that of the FIMT with advantages as easier executation and quicker reading. A simple pre-treatment of Brazilian microplates produced for immune enzymatic assays (PROSIL gave equivalent results and substantial coast reduction, in relation to imported plates (DIFCO. The simplified test can be easily implemented in less sophisticated laboratories, as alternative to the mouse serum neutralization test, still the most largely employed in Brazil, or even to others as RFFIT and FIMT.No presente trabalho foi padronizada uma microtécnica simplificada para a avaliação de anticorpos neutralizantes anti-rábicos com base no RFFIT e no FIMT. Este teste mostrou reprodutibilidade comparável a dos testes originais, sendo de execução mais simples e de leitura mais rápida. Uma microplaca de fabricação nacional para testes imuno-enzimáticos (PROSIL Ind. e Com. pode ser utilizada com resultados equivalentes aos de microplacas Difco ou similar, com substancial redução de custos, mediante tratamento simples e rápido. O teste estudado pode ser implantado facilmente em laboratórios menos sofisticados substituindo com grandes vantagens a prova de soro-neutralização em camundongos ainda a mais empregada rotineiramente no Brasil.

  17. 抗 Eppin 抗体抑制人精子活性运动及相关机制%Inhibition of sperm activated motility by the anti-Eppin antibody and the potential mechanisms

    Institute of Scientific and Technical Information of China (English)

    龙燕; 李庆; 顾爱华

    2013-01-01

    目的:阐明抗附睾蛋白酶抑制剂( Eppin )抗体抑制人精子动力及分析相关机制。方法:将正常男性精子经过percoll分选后分为7组:空白对照组,抗体对照组与40μg · ml -1抗兔多克隆抗体孵育,其余5组分别与不同浓度抗Eppin抗体(浓度分别为2.5、5、10、20和40μg · ml -1)共同孵育4 h后进行精子动力测定,线粒体膜电位(Δψ)、ATP浓度及电镜镜检检测。结果:随着抗Eppin抗体浓度的增加,精子活力下降并呈浓度依赖趋势;当抗Eppin抗体浓度超过5μg · ml-1,精子Δψ及产生ATP浓度显著下降( P<0.05);部分精子线粒体正常环形结构发生异常改变,亚线粒体膜变薄甚至消失。结论:抗Eppin抗体与人精子共孵育后精子线粒体功能及超微结构异常,导致精子活性运动显著下降。%Objective:To clarify the inhibition of sperm activated motility by the anti-Eppin antibody and the potential mechanisms .Methods: Semen samples were obtained by masturbation from normal donors .The motile sperm were collected through discontinuous percoll gradient centrifugation and divided into 7 groups .The sperm in one group were incubated with the 40 μg· ml -1 anti-rabbit antibody and other five groups were incubated with the 2.5, 5, 10, 20 or 40 μg · ml-1 anti-Eppin antibody .Results: After the sperm treated with the anti-Eppin antibody , the results of computer-assisted semen analysis , mitochondrial membrane potential (Δψ) together with ATP production assays measurement and the images of electron microscopy show the reduction of the activated motility,Δψand ATP production , and the aberrations of the helical pattern of mitochondria with the partial loss of sub-mitochondrial reticulum .Conclusion: After the human sperm incubated with the anti-Eppin antibody , the aberrations in ultra structure and the functions of the mitochondria of the sperm result in the reduction of the sperm

  18. The anti-TNF-α antibody infliximab inhibits the expression of fat-transporter-protein FAT/CD36 in a selective hepatic-radiation mouse model.

    Science.gov (United States)

    Martius, Gesa; Cameron, Silke; Rave-Fränk, Margret; Hess, Clemens F; Wolff, Hendrik A; Malik, Ihtzaz A

    2015-01-01

    Previously, we reported a radiation-induced inflammation triggering fat-accumulation through fatty-acid-translocase/cluster of differentiation protein 36 (FAT/CD36) in rat liver. Furthermore, inhibition of radiation-induced FAT/CD36-expression by anti-tumor necrosis factor-α (anti-TNF-α) (infliximab) was shown in vitro. The current study investigates fat-accumulation in a mouse-model of single-dose liver-irradiation (25-Gray) and the effect of anti-TNF-α-therapy on FAT/CD36 gene-expression. Mice livers were selectively irradiated in vivo in presence or absence of infliximab. Serum- and hepatic-triglycerides, mRNA, and protein were analyzed by colorimetric assays, RT-PCR, Immunofluorescence and Western-Blot, respectively. Sudan-staining was used demonstrating fat-accumulation in tissue. In mice livers, early (1-3 h) induction of TNF-α-expression, a pro-inflammatory cytokine, was observed. It was followed by elevated hepatic-triglyceride level (6-12 h), compared to sham-irradiated controls. In contrast, serum-triglyceride level was decreased at these time points. Similar to triglyceride level in mice livers, Sudan staining of liver cryosections showed a quick (6-12 h) increase of fat-droplets after irradiation. Furthermore, expression of fat-transporter-protein FAT/CD36 was increased at protein level caused by radiation or TNF-α. TNF-α-blockage by anti-TNF-α showed an early inhibition of radiation-induced FAT/CD36 expression in mice livers. Immunohistochemistry showed basolateral and cytoplasmic expression of FAT/CD36 in hepatocytes. Moreover, co-localization of FAT/CD36 was detected with α-smooth muscle actin (α-SMA+) cells and F4/80+ macrophages. In summary, hepatic-radiation triggers fat-accumulation in mice livers, involving acute-phase-processes. Accordingly, anti-TNF-α-therapy prevented early radiation-induced expression of FAT/CD36 in vivo. PMID:25739082

  19. Antibody penetration into living cells. V. Interference between two fc gamma receptor-mediated functions: antibody penetration and antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Llerena, J M; Ruíz-Argüelles, A; Alarcón-Segovia, D; Llorente, L; Díaz-Jouanen, E

    1981-01-01

    The same Fc gamma receptor appears to be shared for two important phenomena: antibody-dependent cellular cytotoxicity (ADCC) and antibody penetration into living cells. ADCC is inhibited through interaction with the Fc gamma receptor during the antibody penetration process, indicating that both mechanisms may modulate each other in vitro. PMID:6972908

  20. Anti-influenza M2e antibody

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M.

    2013-04-16

    Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

  1. Anti-influenza M2e antibody

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M. (Santa Fe, NM)

    2011-12-20

    Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

  2. Bispecific antibodies.

    Science.gov (United States)

    Kontermann, Roland E; Brinkmann, Ulrich

    2015-07-01

    Bispecific antibodies (bsAbs) combine specificities of two antibodies and simultaneously address different antigens or epitopes. BsAbs with 'two-target' functionality can interfere with multiple surface receptors or ligands associated, for example with cancer, proliferation or inflammatory processes. BsAbs can also place targets into close proximity, either to support protein complex formation on one cell, or to trigger contacts between cells. Examples of 'forced-connection' functionalities are bsAbs that support protein complexation in the clotting cascade, or tumor-targeted immune cell recruiters and/or activators. Following years of research and development (R&D), the first bsAb was approved in 2009. Another bsAb entered the market in December 2014 and several more are in clinical trials. Here, we describe the potentials of bsAbs to become the next wave of antibody-based therapies, focusing on molecules in clinical development. PMID:25728220

  3. A truncated receptor-binding domain of MERS-CoV spike protein potently inhibits MERS-CoV infection and induces strong neutralizing antibody responses: implication for developing therapeutics and vaccines.

    Directory of Open Access Journals (Sweden)

    Lanying Du

    Full Text Available An emerging respiratory infectious disease with high mortality, Middle East respiratory syndrome (MERS, is caused by a novel coronavirus (MERS-CoV. It was first reported in 2012 in Saudi Arabia and has now spread to eight countries. Development of effective therapeutics and vaccines is crucial to save lives and halt the spread of MERS-CoV. Here, we show that a recombinant protein containing a 212-amino acid fragment (residues 377-588 in the truncated receptor-binding domain (RBD: residues 367-606 of MERS-CoV spike (S protein fused with human IgG Fc fragment (S377-588-Fc is highly expressed in the culture supernatant of transfected 293T cells. The purified S377-588-Fc protein efficiently binds to dipeptidyl peptidase 4 (DPP4, the receptor of MERS-CoV, and potently inhibited MERS-CoV infection, suggesting its potential to be further developed as a therapeutic modality for treating MERS-CoV infection and saving the patients' lives. The recombinant S377-588-Fc is able to induce in the vaccinated mice strong MERS-CoV S-specific antibodies, which blocks the binding of RBD to DPP4 receptor and effectively neutralizes MERS-CoV infection. These findings indicate that this truncated RBD protein shows promise for further development as an effective and safe vaccine for the prevention of MERS-CoV infection.

  4. Comparison of indirect immunofluorescence test for measles antibodies with haemagglutination inhibition and plaque neutralization tests Comparação da reação de imunofluorescência indireta para o vírus do sarampo com as reações de inibição da hemaglutinação e neutralização por redução de placas

    OpenAIRE

    Vanda Akico Ueda Fick de Souza; Cláudio Sérgio Pannuti; Cid Vieira Franco de Godoy; Paul Albrecht; Marta Heloísa Lopes; João da Silva Mendonça

    1990-01-01

    Indirect Immunofluorescence (IFA), Plaque Reduction Neutralization (PRN) and Haemagglutination Inhibition (HI) tests for measles antibodies were carried out in 197 sera obtained from umbilical cord and vaccinated children. The IFA was also applied to blood samples collected with filter paper. IFA results demonstrated that the test is relatively simple to perform, with good reproducibility for different antigen lots. Good correlation was obtained between IFA, PRN and HI antibody titers. Better...

  5. Monoclonal antibodies

    International Nuclear Information System (INIS)

    Monoclonal antibodies (MAbs) are antibodies having single specificity for a given antigen site (epitope). The development of hybridoma technology and the relative ease by which MAbs can be prepared has revolutionized many aspects of serological applications in diagnosis and differentiation of disease producing agents. The property of monospecificity offers advantages in diagnostic applications over polyclonal sera in that tests can be defined exactly with regard to the antigen detected and the affinity of reaction between the given antigenic site and the monoclonal reagent. In addition, MAbs offer better possibilities for test standardization, because the same reagent can be used in different laboratories. Such an MAb can be supplied by a central laboratory or 'grown' from hybridoma cells, ensuring that the resultant product is identical from laboratory to laboratory and that the part of the test involving the MAb reaction is the same. The methodologies for inoculation regimes, mice, cloning methods, selection of fusion partners, etc., have been validated extensively in developed country laboratories. The decision to establish a MAb production facility must be examined on a strict cost-benefit basis, since it is still expensive to produce a product. There are many MAbs available that should be sought to allow exploitation in developing tests. If a production facility is envisaged, it should produce reagents for national needs, i.e. there should be a clear problem oriented approach whereby exact needs are defined. In the field of veterinary applications, MAbs are the central reagent in many immunoassays based on the enzyme linked immunosorbent assay (ELISA). The development of specific tests for diagnosing diseases is dominated by MAbs and has been fuelled by a strong research base, mainly in developed countries allied to developing countries through the study of related diseases. Thus, there are very many assays dependent on MAbs, some of which form the basis of

  6. Monoclonal antibodies.

    Science.gov (United States)

    2009-01-01

    The ability to produce and exploit monoclonal antibodies (mAbs) has revolutionized many areas of biological sciences. The unique property of an mAb is that it is a single species of immunoglobulin (IG) molecule. This means that the specificity of the interaction of the paratopes on the IG, with the epitopes on an antigenic target, is the same on every molecule. This property can be used to great benefit in immunoassays to provide tests of defined specificity and sensitivity, which improve the possibilities of standardization. The performance of assays can often be determined relating the actual weight of antibody (hence the number of molecules) to the activity. Often the production of an mAb against a specific epitope is the only way that biological entities can be differentiated. This chapter outlines the areas involving the development of assays based on mAbs. The problems involved address include the physical aspects of mAbs and how they may affect assay design and also the implications of results based on monospecific reagents. Often these are not fully understood, leading to assays that are less than satisfactory, which does not justify the relatively high cost of preparing and screening of mAbs. There are many textbooks and reviews dealing with the preparation of mAbs, the principles involved, and various purification and manipulative methods for the preparation of fragments and conjugation. There has been little general information attempting to summarize the best approaches to assay design using mAbs. Much time can be wasted through bad planning, and this is particularly relevant to mAbs. A proper understanding of some basic principles is essential. It is beyond the scope of this chapter to discuss all aspects, but major areas are highlighted. PMID:19219589

  7. Monoclonal antibodies as diagnostics; an appraisal

    Directory of Open Access Journals (Sweden)

    Siddiqui M

    2010-01-01

    Full Text Available Ever since the development of Hybridoma Technology in 1975 by Kohler and Milstein, our vision for antibodies as tools for research for prevention, detection and treatment of diseases, vaccine production, antigenic characterization of pathogens and in the study of genetic regulation of immune responses and disease susceptibility has been revolutionized. The monoclonal antibodies being directed against single epitopes are homogeneous, highly specific and can be produced in unlimited quantities. In animal disease diagnosis, they are very useful for identification and antigenic characterization of pathogens. Monoclonal antibodies have tremendous applications in the field of diagnostics, therapeutics and targeted drug delivery systems, not only for infectious diseases caused by bacteria, viruses and protozoa but also for cancer, metabolic and hormonal disorders. They are also used in the diagnosis of lymphoid and myeloid malignancies, tissue typing, enzyme linked immunosorbent assay, radio immunoassay, serotyping of microorganisms, immunological intervention with passive antibody, antiidiotype inhibition, or magic bullet therapy with cytotoxic agents coupled with anti mouse specific antibody. Recombinant deoxyribonucleic acid technology through genetic engineering has successfully led to the possibility of reconstruction of monoclonal antibodies viz. chimeric antibodies, humanized antibodies and complementarily determining region grafted antibodies and their enormous therapeutic use.

  8. Monoclonal antibodies to Bacteroides fragilis lipopolysaccharide.

    OpenAIRE

    Linko-Kettunen, L; Arstila, P; Jalkanen, M; Jousimies-Somer, H; Lassila, O; Lehtonen, O P; Weintraub, A; Viljanen, M K

    1984-01-01

    Monoclonal antibodies (MoAbs) to the lipopolysaccharide (LPS) of Bacteroides fragilis were produced by immunizing mice before hybridization with bacterial outer membranes solubilized with Triton X-100. Nineteen stabile clones were established. They all produced antibodies that reacted more strongly with purified B. fragilis LPS than with crude sonicated antigen in an enzyme immunoassay. Four MoAbs were studied by immunoblotting and enzyme immunoassay inhibition. Immunoblotting confirmed that ...

  9. T-cell activation. VI. Inhibitory and stimulatory effects of anti-major histocompatibility complex class I antibodies in allogeneic mixed lymphocyte culture

    DEFF Research Database (Denmark)

    Röpke, M; Röpke, C; Claesson, Mogens Helweg

    1993-01-01

    Murine T splenocytes stimulated in primary allogeneic mixed lymphocyte culture (MLC) were incubated with soluble anti-major histocompatibility complex (MHC) class I monoclonal antibodies. These antibodies induced inhibition in the cytotoxicity of the responding population and this inhibition was...

  10. Polyclonal anti-idiotypic antibodies mimicking the small cell lung carcinoma antigen cluster-5A interact with a panel of antibodies and induce specific immune response in animals.

    OpenAIRE

    Zwicky, C.; Stahel, R A; Jaksche, H.; Waibel, R.; Lehmann, H. P.; Loibner, H

    1991-01-01

    Polyclonal anti-idiotypic antibodies (ab2) were generated by immunising goats with the murine IgG2a monoclonal antibody SWA20 which recognises the SCLC antigen cluster-5A, a tumour-associated sialoglycoprotein. Ab2 was shown to bind specifically to antibody SWA20, but not to isotype matched control antibodies. Pre-incubation with ab2 completely inhibited target cell binding of antibody SWA20 and of four other antibodies to cluster-5A antigen, while no effect was seen with antibodies to cluste...

  11. Antibody-mediated immune suppression is improved when blends of anti-RBC monoclonal antibodies are used in mice.

    Science.gov (United States)

    Bernardo, Lidice; Amash, Alaa; Marjoram, Danielle; Lazarus, Alan H

    2016-08-25

    Although the prevention of hemolytic disease of the fetus and newborn is highly effective using polyclonal anti-D, a recombinant alternative is long overdue. Unfortunately, anti-D monoclonal antibodies have been, at best, disappointing. To determine the primary attribute defining an optimal antibody, we assessed suppression of murine red blood cell (RBC) immunization by single-monoclonal antibodies vs defined blends of subtype-matched antibodies. Allogeneic RBCs expressing the HOD antigen (hen egg lysozyme [HEL]-ovalbumin-human transmembrane Duffy(b)) were transfused into naïve mice alone or together with selected combinations of HEL-specific antibodies, and the resulting suppressive effect was assessed by evaluating the antibody response. Polyclonal HEL antibodies dramatically inhibited the antibody response to the HOD antigen, whereas single-monoclonal HEL antibodies were less effective despite the use of saturating doses. A blend of monoclonal HEL-specific antibodies reactive with different HEL epitopes significantly increased the suppressive effect, whereas a blend of monoclonal antibodies that block each other's binding to the HEL protein did not increase suppression. In conclusion, these data show that polyclonal antibodies are superior to monoclonal antibodies at suppressing the immune response to the HOD cells, a feature that can be completely recapitulated using monoclonal antibodies to different epitopes. PMID:27330002

  12. Monoclonal antibodies against rabbit mammary prolactin receptors. Specific antibodies to the hormone binding domain

    International Nuclear Information System (INIS)

    Three monoclonal antibodies (M110, A82, and A917) were obtained by fusing myeloma cells and spleen cells from mice immunized with partially purified rabbit mammary gland prolactin (PRL) receptors. All 3 antibodies were capable of complete inhibition of 125I-ovine prolactin (oPRL) binding to rabbit mammary PRL receptors in either particulate or soluble form. M110 showed slightly greater potency than oPRL in competing for 125I-oPRL binding. These antibodies also inhibited PRL binding to microsomal fractions from rabbit liver, kidney, adrenal, ovary, and pig mammary gland, although A82 showed poor inhibition in pig mammary gland. There was no cross-reaction of any of the 3 monoclonal antibodies (mAbs) for the other species tested: human (T-47D breast cancer cells) and rat (liver, ovary). In order to confirm that these antibodies are specific to the binding domain, antibodies were purified, iodinated, and binding characteristics were investigated. 125I-M110 and 125I-A82 binding was completely inhibited by lactogenic hormones, whereas nonlactogenic hormones did not cross-react. Competition of 125I-M110 by oPRL was comparable to that of 125I-oPRL by unlabeled oPRL, while 125I-A917 binding was only partially competed (30-60%) by lactogenic hormones. Tissue and species specificity of labeled antibody binding paralleled results of binding inhibition experiments using 125I-oPRL. In addition, A82 and A917 completely inhibited 125I-M110 binding. In contrast, 125I-A82 binding was stimulated by A917 and 125I-A917 binding was stimulated by A82

  13. The determination of rubella hemaogglutination inhibition antibodies protective concentration with RV-IgG standard%利用RV-IgG标准品对风疹疫苗免疫后血清血凝抑制抗体保护浓度的测定

    Institute of Scientific and Technical Information of China (English)

    赵冠棋; 程喆歆; 陈曦; 王燕; 徐维祯; 王华庆; 谷鸿喜

    2012-01-01

    目的 利用风疹病毒的IgG标准品(RV-IgG)进行定量ELISA试验和血凝抑制试验,以测定风疹疫苗免疫后血清血凝抑制(HI)抗体的保护浓度,并验证试剂盒的准确性.方法 RV-IgG标准品和10对风疹疫苗免疫前后血清的定量ELISA试验;风疹病毒血凝素的粗提以及血凝试验;RV-IgG标准品的血凝抑制试验测定其血凝完全被抑制时RV-IgG浓度.结果 将RV-IgG标准品稀释为8个不同浓度梯度做定量ELISA,所测得的浓度值与已知浓度相比无统计学意义(P >0.05);10对风疹疫苗免疫前后人血清抗体浓度进行比较,免疫后血清抗体浓度显著升高(t =2.151,P<0.05);风疹病毒血凝素的凝集效价为1∶128,RV-IgG标准品血凝抑制效价为1∶32,对应的HI抗体浓度为25 IU/ml.结论 实验结果证实血清中风疹病毒HI抗体保护浓度为25 IU/ml;风疹疫苗初次免疫后血清抗体保护性阳转率可达到80%.%Objective To determine the rubella hemaogglutination inhibition (HI) antibodies concentration in persons with rubella vaccine immune serum by RV-IgG standard-based quantitative ELISA and HI test,and verify the accuracy of the kit.Methods RV-IgG standard which was diluted to eight different concentrations,and 10 pairs of serum samples before and after immunized were used to detected the rubella virus serum antibody by quantitative ELISA test,respectively.The hemagglutination tests were performed with rubella virus haemagglutinin which were crudely extracted.The hemagglutination inhibition tests were respectively proceeded with RV-IgG standard and serum samples.After the comparison of the results,rubella antibody protective concentration was confirmed.Results There was no significant difference ( t =2.151,P > 0.05 ) between the measured concentration and the known concentration of RV-IgG standard diluted by the quantitative ELISA test.Comparing 10 pairs of the serum antibody level before and after vaccination,the concentration of

  14. Studies on Purification of Methamidophos Monoclonal Antibodies and Comoarative Immunoactivity of Purified Antibodies

    Institute of Scientific and Technical Information of China (English)

    SU-QING ZHAO; YUAN-MING SUN; CHUN-YAN ZHANG; XIAO-YU HUANG; HOU-RUI ZHANG; ZHEN-YU ZHU

    2003-01-01

    Objective To purify Methamidophos (Met) monoclonal antibodies with two methods andcompare immune activity of purified antibodies. Method Caprylic acid ammonium sulphateprecipition (CAASP) method and Sepharose protein-A (SPA) affinity chromatography method wereused to purify Met monoclonal antibodies, UV spectrum scanning was used to determine proteincontent and recovery of purified antibodies, sodium dodecylsulphate polyacrylamide gelelectrophoresis (SDS-PAGE) was used to analyze the purity of purified antibodies, and enzyme-linkedimmunosorbent assay (ELISA) was used to determine immune activity of purified antibodies.Results Antibody protein content and recovery rate with CAASP method were 7.62 mg/mL and8.05% respectively, antibody protein content and recovery rate with SPA method were 6.45 mg/mLand 5.52% respectively. Purity of antibodies purified by SPA method was higher than that by CAASPmethod. The half-maximal inhibition concentration (IC50) of antibodies purified by SPA to Met was181.26 μg/mL, and the linear working range and the limit of quantification (LOD) were 2.43-3896.01μg/mL and 1.03 μg/mL, respectively. The IC50 of antibodies purified by CAASP to Met was 352.82μg/mL, and the linear working range and LOD were 10.91-11412.29 ug/mL and 3.42 μg/mL,respectively. Conclusion Antibodies purified by SPA method are better than those by CAASPmethod, and Met monoclonal antibodies purified by SPA method can be used to prepare gold-labelledtesting paper for analyzing Met residue in vegetable and drink water.

  15. Antibodies and Selection of Monoclonal Antibodies.

    Science.gov (United States)

    Hanack, Katja; Messerschmidt, Katrin; Listek, Martin

    2016-01-01

    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. PMID:27236550

  16. Monoclonal antibodies against chicken interleukin-6

    Science.gov (United States)

    Monoclonal antibodies (mAb) were produced against a recombinant (r) chicken interleukin-6 (IL-6). Eight mAbs that were produced were tested for isotype; ability to inhibit recombinant forms of chicken (ch), human (h) and murine (m) IL-6; and recognition of rchIL-6 by Western immunoblotting. The mA...

  17. Monoclonal Antibodies Attached to Carbon Nanotube Transistors for Paclitaxel Detection

    Science.gov (United States)

    Lee, Wonbae; Lau, Calvin; Richardson, Mark; Rajapakse, Arith; Weiss, Gregory; Collins, Philip; UCI, Molecular Biology; Biochemistry Collaboration; UCI, Departments of Physics; Astronomy Collaboration

    Paclitaxel is a naturally-occurring pharmaceutical used in numerous cancer treatments, despite its toxic side effects. Partial inhibition of this toxicity has been demonstrated using weakly interacting monoclonal antibodies (3C6 and 8A10), but accurate monitoring of antibody and paclitaxel concentrations remains challenging. Here, single-molecule studies of the kinetics of antibody-paclitaxel interactions have been performed using single-walled carbon nanotube field-effect transistors. The devices were sensitized with single antibody attachments to record the single-molecule binding dynamics of paclitaxel. This label-free technique recorded a range of dynamic interactions between the antibody and paclitaxel, and it provided sensitive paclitaxel detection for pM to nM concentrations. Measurements with two different antibodies suggest ways of extending this working range and uncovering the mechanistic differences among different antibodies.

  18. Cross-domain inhibition of TACE ectodomain

    DEFF Research Database (Denmark)

    Tape, Christopher J; Willems, Sofie H; Dombernowsky, Sarah L;

    2011-01-01

    target for the treatment of cancer and arthritis. Prior attempts to antagonize cell-surface TACE activity have focused on small-molecule inhibition of the metalloprotease active site. Given the highly conserved nature of metalloprotease active sites, this paradigm has failed to produce a truly specific...... individual antibody variable domains to desired epitopes. The resulting "cross-domain" human antibody is a previously undescribed selective TACE antagonist and provides a unique alternative to small-molecule metalloprotease inhibition....

  19. Antiphospholipid Antibody Syndrome

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Antiphospholipid Antibody Syndrome? Antiphospholipid (AN-te-fos-fo-LIP-id) antibody ... weeks or months. This condition is called catastrophic antiphospholipid syndrome (CAPS). People who have APS also are at ...

  20. The antibody mining toolbox

    OpenAIRE

    D'Angelo, Sara; Glanville, Jacob; Ferrara, Fortunato; Naranjo, Leslie; Gleasner, Cheryl D.; Shen, Xiaohong; Bradbury, Andrew RM; Kiss, Csaba

    2013-01-01

    In vitro selection has been an essential tool in the development of recombinant antibodies against various antigen targets. Deep sequencing has recently been gaining ground as an alternative and valuable method to analyze such antibody selections. The analysis provides a novel and extremely detailed view of selected antibody populations, and allows the identification of specific antibodies using only sequencing data, potentially eliminating the need for expensive and laborious low-throughput ...

  1. Heavy chain only antibodies

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  2. Hepatitis A virus antibody

    International Nuclear Information System (INIS)

    A description is presented of a radioimmunoassay designed to prove the presence of the antibody against the hepatitis A virus (HA Ab, anti-Ha) using an Abbott HAVAB set. This proof as well as the proof of the antibody against the nucleus of the hepatitis B virus is based on competition between a normal antibody against hepatitis A virus and a 125I-labelled antibody for the binding sites of a specific antigen spread all over the surface of a tiny ball; this is then indirect proof of the antibody under investigation. The method is described of reading the results from the number of impulses per 60 seconds: the higher the titre of the antibody against the hepatitis A virus in the serum examined, the lower the activity of the specimen concerned. The rate is reported of incidence of the antibody against the hepatitis A virus in a total of 68 convalescents after hepatitis A; the antibody was found in 94.1%. The immunoglobulin made from the convalescents' plasma showed the presence of antibodies in dilutions as high as 1:250 000 while the comparable ratio for normal immunoglobulin Norga was only 1:2500. Differences are discussed in the time incidence of the antibodies against the hepatitis A virus, the antibodies against the surface antigen of hepatitis B, and the antibody against the nucleus of the hepatitis V virus. (author)

  3. Suppression of contractile force in muscle fibers by antibody to myosin subfragment 2.

    OpenAIRE

    Lovell, S; Karr, T; Harrington, W F

    1988-01-01

    Polyclonal antibody directed against the subfragment-2 region of myosin was purified by affinity chromatography. Skinned muscle fibers that had been preincubated with antibody were able to sustain only 7% of the active isometric force generated by control fibers. The effect of antibody on force production could not be accounted for by inhibition of ATP turnover.

  4. Monoclonal antibodies and cancer

    International Nuclear Information System (INIS)

    The usefulness of radiolabeled monoclonal antibodies for imaging and treatment of human (ovarian) cancer was investigated. A review of tumor imaging with monoclonal antibodies is presented. Special attention is given to factors that influence the localization of the antibodies in tumors, isotope choice and methods of radiolabeling of the monoclonal antibodies. Two monoclonal antibodies, OC125 and OV-TL3, with high specificity for human epithelial ovarian cancer are characterized. A simple radio-iodination technique was developed for clinical application of the monoclonal antibodies. The behavior of monoclonal antibodies in human tumor xenograft systems and in man are described. Imaging of tumors is complicated because of high background levels of radioactivity in other sites than the tumor, especially in the bloodpool. A technique was developed to improve imaging of human tumor xenographs in nude mice, using subtraction of a specific and a non-specific antibody, radiolabeled with 111In, 67Ga and 131I. To investigate the capability of the two monoclonal antibodies, to specifically localize in human ovarian carcinomas, distribution studies in mice bearing human ovarian carcinoma xenografts were performed. One of the antibodies, OC125, was used for distribution studies in ovarian cancer patients. OC125 was used because of availability and approval to use this antibody in patients. The same antibody was used to investigate the usefulness of radioimmunoimaging in ovarian cancer patients. The interaction of injected radiolabeled antibody OC125 with circulating antigen and an assay to measure the antibody response in ovarian cancer patients after injection of the antibody is described. 265 refs.; 30 figs.; 19 tabs

  5. Production, isolation, and characterization of rabbit anti-idiotypic antibodies directed against human antithyrotrophin receptor antibodies.

    Science.gov (United States)

    Baker, J R; Lukes, Y G; Burman, K D

    1984-01-01

    Previous studies have shown that anti-idiotypic antibodies can be developed in vivo through animal immunization with idiotype, and that these antibodies can be isolated from other anti-immunoglobulin antibodies by affinity purification. These techniques have relied on large amounts of idiotype, which were produced either by hyperimmunization or by monoclonal antibodies, to serve as the affinity adsorbent. In the present study, we produced anti-idiotypic antibodies to human anti-thyroid-stimulating hormone (TSH) receptor antibodies by first injecting rabbits with (TSH receptor purified) IgG from Graves' patients. The resulting antiserum was then adsorbed with Sepharose-coupled TSH in an attempt to specifically bind and isolate the anti-idiotype. The antibody obtained from this process was shown to bind specifically to TSH receptor-binding antibodies from Graves' patients, and this binding could be inhibited by 56% with the addition of 10(-4) M TSH but not by HCG (10(-2) M). The anti-idiotype also bound to TSH, and this binding could be specifically inhibited by receptor-purified Graves' IgG (60% inhibition at 10 micrograms/ml IgG), but not by IgG from normal subjects (no inhibition at 50 micrograms/ml IgG). In a TSH receptor binding assay, the anti-idiotype could inhibit TSH receptor binding in Graves' sera at a 1,000-fold lower concentration than could anti-kappa/lambda antiserum; the anti-idiotypic antiserum also inhibited in vitro TSH-mediated adenylate cyclase stimulation at an IgG concentration of 5 micrograms/ml, while heterologous anti-TSH antisera and normal IgG at similar concentrations had no effect. Finally, despite being generated against a single patient's TSH receptor binding antibody, the anti-idiotype was able to block TSH receptor binding in the serum of six other Graves' patients, thus suggesting that there may be conformational conservation in the antigen that is recognized by different individuals' TSH receptor-binding immunoglobulins. PMID

  6. Monoclonal antibodies in targeted therapy

    Directory of Open Access Journals (Sweden)

    Beata Powroźnik

    2012-09-01

    Full Text Available Targeted therapy is a new therapeutic method consisting in the inhibition of specific molecular pathways. In modern therapy, the key role is played by monoclonal antibodies, included in the group of biological agents. The success of molecularly targeted therapy is to define the proper “molecular target”, selecting the right drug active against a specific “target” and selecting a group of patients who benefit from treatment. Introduction of targeted therapy resulted in improved results of the treatment of many serious and chronic diseases. In general, targeted molecular therapies have good toxicity profiles, but some patients are exquisitely sensitive to these drugs and can develop particular and severe toxicities. Patient selection and proper monitoring significantly decrease the risk of life-threatening adverse events. Data concerning late side effects are still unavailable because of the short follow-up of molecularly targeted therapy. Currently in the U.S. and Europe there are approximately 31 registered therapeutic monoclonal antibodies, while 160 are subjected to clinical trials. This paper presents an overview of therapeutic monoclonal antibodies currently used in therapy and the present state of knowledge about them. 

  7. Central role of immunoglobulin (Ig) E in the induction of lung eosinophil infiltration and T helper 2 cell cytokine production: inhibition by a non-anaphylactogenic anti-IgE antibody

    OpenAIRE

    1996-01-01

    Elevated levels of immunoglobulin (Ig) E are associated with bronchial asthma, a disease characterized by eosinophilic inflammation of the airways. Activation of antigen-specific T helper (Th) 2 cells in the lung with the subsequent release of interleukin (IL) 4 and IL-5 is believed to play an important role in the pathogenesis of this disease. In this study, we have used a non-anaphylactogenic anti-mouse-IgE antibody to investigate the relationship between IgE, airway eosinophil infiltration...

  8. Monoclonal antibody 4C5 prevents activation of MMP2 and MMP9 by disrupting their interaction with extracellular HSP90 and inhibits formation of metastatic breast cancer cell deposits

    OpenAIRE

    Patsavoudi Evangelia; El Hamidieh Avraam; Stellas Dimitris

    2010-01-01

    Abstract Background Heat shock protein 90 (HSP90) is a molecular chaperone that is considered a new target for the treatment of cancer. Increasing data reveal an extracellular chaperoning activity for HSP90. Here we investigate the interaction of the secreted isoforms of HSP90 with matrix metalloproteinases (MMP) MMP2 and MMP9. Moreover we examine the role of a monoclonal antibody (mAb) against HSP90, mAb 4C5, regarding these interactions and its value as a potential inhibitor of human breast...

  9. Antibody responses of horses to equine influenza viruses during a postepizootic period in Japan.

    OpenAIRE

    Goto, H; Shimizu, K; Taya, Y; Noda, H; Tokunaga, T

    1982-01-01

    The antibody responses to equine influenza viruses were investigated during a postepizootic period of the disease. Serum samples were collected from a total of 128 horses on three occasions during the years 1967-77. No significant increase of hemagglutination-inhibition antibody titers to subtypes 1 and 2 of equine influenza virus were detected in any of the sera tested. The maternal hemagglutination-inhibition antibody titers of foals decreased over a four month interval. A marked increase o...

  10. Neutralization of lymphokine-mediated antirickettsial activity of fibroblasts and macrophages with monoclonal antibody specific for murine interferon gamma.

    OpenAIRE

    Jerrells, T R; Turco, J; Winkler, H H; Spitalny, G L

    1986-01-01

    Lymphokine-mediated inhibition of Rickettsia prowazekii multiplication in L929 fibroblasts was eliminated by treatment of the lymphokine with a monoclonal antibody specific for interferon-gamma. Soluble monoclonal antibody and antibody conjugated to Sepharose beads were equally effective. Macrophage activation to limit the multiplication of Rickettsia conorii was eliminated with antibody-conjugated beads; however, neutralization of the ability to activate macrophages with soluble antibody was...

  11. Immune mediated mechanism for thrombosis: antiphospholipid antibody binding to platelet membranes.

    OpenAIRE

    M. A. Khamashta; Harris, E N; Gharavi, A E; Derue, G; Gil, A.; Vázquez, J. J.; Hughes, G R

    1988-01-01

    Because thrombocytopenia occurs frequently in patients with anticardiolipin (aCL) antibodies and thrombosis, some investigators have proposed that aCL antibodies may play a direct part in thrombosis by binding and activating platelets. To test this proposal experiments were performed to determine whether aCL antibodies can bind platelets. Preincubation of aCL positive sera with freeze-thawed platelets caused significant inhibition of aCL activity in four serum samples tested. Antibodies with ...

  12. Antibodies against the light chain of tetanus toxin in human sera.

    OpenAIRE

    Lin, C S.; Habig, W H; Hardegree, M C

    1985-01-01

    Tetanus toxoid elicits protective antibodies against tetanus toxin in humans and animals. It has been reported that antitoxin from immunized humans contains no anti-light chain antibodies, based on immunodiffusion and quantitative precipitin analyses. We confirmed the absence of precipitating anti-light chain antibodies in tetanus immune globulin. However, the presence of antibodies against the light chain of the toxin was shown by direct binding and inhibition analyses, using enzyme-linked i...

  13. Decay of maternal antibodies in broiler chickens.

    Science.gov (United States)

    Gharaibeh, Saad; Mahmoud, Kamel

    2013-09-01

    The objective of this study was to determine the decay rate of maternal antibodies against major broiler chicken pathogens. A total of 30 one-day-old broiler chicks were obtained from a commercial hatchery and reared in isolation. These chicks were retrieved from a parent flock that received a routine vaccination program. Chicks were bled at hatch and sequentially thereafter every 5 d through 30 d of age. Maternal antibody titers were measured by ELISA for avian encephalomyelitis (AEV), avian influenza virus (AIV), chicken anemia virus (CAV), infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), infectious laryngotracheitis virus (ILTV), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), and reovirus (Reo). Maternal antibody titers for Newcastle disease virus (NDV) were measured using a hemagglutination inhibition test. Half-life estimates of maternal antibody titers were 5.3, 4.2, 7, 5.1, 3.9, 3.8, 4.9, 4.1, 6.3, and 4.7 d for AEV, AIV, CAV, IBDV, IBV, ILTV, MG, MS, NDV, and Reo, respectively. The statistical analysis revealed significant differences among half-lives of maternal antibody titers against certain pathogens. Furthermore, all maternal antibody titers were depleted by 10 d of age except for IBDV. PMID:23960115

  14. Anti-human CD73 monoclonal antibody inhibits metastasis formation in human breast cancer by inducing clustering and internalization of CD73 expressed on the surface of cancer cells

    DEFF Research Database (Denmark)

    Terp, Mikkel G; Olesen, Kristina A; Christensen, Eva Arnspang;

    2013-01-01

    -linking of CD73, because both whole IgG anti-CD73 AD2 mAb and Fab' fragments thereof exhibited this effect. Ex vivo treatment of different breast cancer cell lines with anti-CD73 AD2 mAb before i.v. injection into mice inhibited extravasation/colonization of circulating tumor cells and significantly reduced...... metastasis development. This effect was also observed when the cancer cell-surface expression of CD73 was significantly reduced by small interfering RNA knockdown. The antimetastatic activity is epitope specific, as another Ab that efficiently binds CD73-expressing live cancer cells did not lead to CD73...... internalization and metastasis inhibition. Furthermore, anti-CD73 AD2 mAb inhibited development of metastasis in a spontaneous animal model of human metastatic breast cancer. Our study shows that some anti-CD73 mAbs cause cell-surface clustering of CD73 followed by internalization, thus inhibiting the ability of...

  15. B-cell inhibition by cross-linking CD79b is superior to B-cell depletion with anti-CD20 antibodies in treating murine collagen-induced arthritis

    Czech Academy of Sciences Publication Activity Database

    Bruhl, H.; Cihak, J.; Talke, Y.; Rodriguez-Gomez, M.; Hermann, F.; Goebel, N.; Renner, K.; Plachý, Jiří; Stangassinger, M.; Archemann, S.; Nimmerjahn, F.; Mack, M.

    2015-01-01

    Roč. 45, č. 3 (2015), s. 705-715. ISSN 0014-2980 Institutional support: RVO:68378050 Keywords : Arthritis * B cells * B-cell depletion * B-cell inhibition * CD79b * Humoral immune response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.034, year: 2014

  16. Engineering antibody therapeutics.

    Science.gov (United States)

    Chiu, Mark L; Gilliland, Gary L

    2016-06-01

    The successful introduction of antibody-based protein therapeutics into the arsenal of treatments for patients has within a few decades fostered intense innovation in the production and engineering of antibodies. Reviewed here are the methods currently used to produce antibodies along with how our knowledge of the structural and functional characterization of immunoglobulins has resulted in the engineering of antibodies to produce protein therapeutics with unique properties, both biological and biophysical, that are leading to novel therapeutic approaches. Antibody engineering includes the introduction of the antibody combining site (variable regions) into a host of architectures including bi and multi-specific formats that further impact the therapeutic properties leading to further advantages and successes in patient treatment. PMID:27525816

  17. Cysteinylation of a monoclonal antibody leads to its inactivation.

    Science.gov (United States)

    McSherry, Troy; McSherry, Jennifer; Ozaeta, Panfilo; Longenecker, Kenton; Ramsay, Carol; Fishpaugh, Jeffrey; Allen, Steven

    2016-01-01

    Post-translational modifications can have a signification effect on antibody stability. A comprehensive approach is often required to best understand the underlying reasons the modification affects the antibody's potency or aggregation state. Monoclonal antibody 001 displayed significant variation in terms of potency, as defined by surface plasmon resonance testing (Biacore), from lot to lot independent of any observable aggregation or degradation, suggesting that a post-translational modification could be driving this variability. Analysis of different antibody lots using analytical hydrophobic interaction chromatography (HIC) uncovered multiple peaks of varying size. Electrospray ionization mass spectrometry (ESI-MS) indicated that the antibody contained a cysteinylation post-translational modification in complementarity-determining region (CDR) 3 of the antibody light chain. Fractionation of the antibody by HIC followed by ESI-MS and Biacore showed that the different peaks were antibody containing zero, one, or two cysteinylation modifications, and that the modification interferes with the ability of the modified antibody arm to bind antigen. Molecular modeling of the modified region shows that this oxidation of an unpaired cysteine in the antibody CDR would block a potential antigen binding pocket, suggesting an inhibition mechanism. PMID:27050640

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

    Directory of Open Access Journals (Sweden)

    Sharad P Adekar

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

  19. Affinity purification of antibodies

    Science.gov (United States)

    Antibodies are provided in a variety of formats that includes antiserum, hybridoma culture supernatant or ascites. They can all be used successfully in crude form for the detection of target antigens by immunoassay. However, it is advantageous to use purified antibody in defined quantity to facil...

  20. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  1. Production Of Human Antibodies

    Science.gov (United States)

    Sammons, David W.; Neil, Garry A.

    1993-01-01

    Process for making human monoclonal antibodies based on combination of techniques. Antibodies made active against specific antigen. Process involves in vivo immunization of human B lymphocyte cells in mice. B cells of interest enriched in vitro before fusion. Method potentially applicable to any antigen. Does not rely on use of Epstein-Barr virus at any step. Human lymphocytes taken from any source.

  2. RBC Antibody Screen

    Science.gov (United States)

    ... the baby is Rh-positive and the mother's antibody status is negative for anti-D, the mother is given additional RhIG. This test also may be used to help diagnose autoimmune-related hemolytic anemia ... when a person produces antibodies against his or her own RBC antigens. This ...

  3. Antibody affinity maturation

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise

    Yeast surface display is an effective tool for antibody affinity maturation because yeast can be used as an all-in-one workhorse to assemble, display and screen diversified antibody libraries. By employing the natural ability of yeast Saccharomyces cerevisiae to efficiently recombine multiple DNA...

  4. Assays of thyroid-stimulating antibody

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, J.M.; Zakarija, M.

    1985-01-01

    A comparison is presented of the two major assay methods of thyroid-stimulating antibody (TSAb) of Graves' disease. The basic procedures involve: (1) some index of thyroid stimulation, usually in vitro, using TSAb to indicate its activity; and (2) indirect recognition by assessment of the inhibition of binding of radioiodinated thyrotropin (TSH) to a preparation of its receptor, i.e., TSH-binding inhibition or TBI. There is potential for misinterpretation of data acquired by testing patients' sera by one or the other basic procedure.

  5. Assays of thyroid-stimulating antibody

    International Nuclear Information System (INIS)

    A comparison is presented of the two major assay methods of thyroid-stimulating antibody (TSAb) of Graves' disease. The basic procedures involve: (1) some index of thyroid stimulation, usually in vitro, using TSAb to indicate its activity; and (2) indirect recognition by assessment of the inhibition of binding of radioiodinated thyrotropin (TSH) to a preparation of its receptor, i.e., TSH-binding inhibition or TBI. There is potential for misinterpretation of data acquired by testing patients' sera by one or the other basic procedure

  6. Selection of Recombinant Human Antibodies.

    Science.gov (United States)

    Tomszak, Florian; Weber, Susanne; Zantow, Jonas; Schirrmann, Thomas; Hust, Michael; Frenzel, André

    2016-01-01

    Since the development of therapeutic antibodies the demand of recombinant human antibodies is steadily increasing. Traditionally, therapeutic antibodies were generated by immunization of rat or mice, the generation of hybridoma clones, cloning of the antibody genes and subsequent humanization and engineering of the lead candidates. In the last few years, techniques were developed that use transgenic animals with a human antibody gene repertoire. Here, modern recombinant DNA technologies can be combined with well established immunization and hybridoma technologies to generate already affinity maturated human antibodies. An alternative are in vitro technologies which enabled the generation of fully human antibodies from antibody gene libraries that even exceed the human antibody repertoire. Specific antibodies can be isolated from these libraries in a very short time and therefore reduce the development time of an antibody drug at a very early stage.In this review, we describe different technologies that are currently used for the in vitro and in vivo generation of human antibodies. PMID:27236551

  7. Characterization of human serum spreading factor with monoclonal antibody.

    OpenAIRE

    Barnes, D W; Silnutzer, J; See, C; Shaffer, M

    1983-01-01

    Serum spreading factor is a glycoprotein isolated from human serum that promotes spreading of a variety of cell types on culture dishes. We developed mouse hybridoma lines secreting monoclonal antibody to serum spreading factor that markedly inhibited the rate of serum spreading factor-promoted spreading of both fibroblastic and epithelial cells in culture. Fibronectin-promoted cell spreading was unaffected by monoclonal antibody to serum spreading factor, and the factor appeared to be distin...

  8. Affitins as alternative to antibodies

    International Nuclear Information System (INIS)

    Full text of publication follows. We have developed the use of Sac7d archaeal polypeptide and its homologues as a non-antibody scaffold from which artificial affinity proteins (Affitins) can be derived with a number of favorable properties. Affitins show affinity (sub-nanomolar) and specificity that compare well with those of antibodies [Ref.1]. They are thermally (up to 90 C. degrees) and chemically stable (pH 0-12+, denaturants), well expressed in E. coli (up to 200 mg/L), lack disulfide bridge and have a size compatible with chemical synthesis (7 kDa). We have demonstrated their use as reagents for intra-cellular inhibition [Ref.1], affinity purification [Ref.2], immuno-localization [Ref.3], protein chip array [Ref.4] and biosensors [Ref.5]. We have also shown that Affitins are plastic enough to tolerate several mutagenesis schemes while their fold and their favorable properties are conserved [Ref.6]. Compared to Affitins, monoclonal antibodies are 20 times larger, less stable and more complex molecules. Furthermore, the remarkable stability properties of Affitins make them suited for demanding labeling protocols that are usually used for peptides. All together, these results show that Affitins should be well suited for biomedical applications where fine tuning of the affinity reagent properties is needed. References: [Ref.1] Mouratou, B. et al., (2007), Proc Natl Acad Sci U S A 104, 17983-17988; [Ref.2] Krehenbrink, M. et al. (2008), J Mol Biol 383, 1058-1068; [Ref.3] Buddelmeijer, N. et al. (2009), J Bacteriol 191, 161-168; [Ref.4] Cinier, M. et al. (2009), Bioconjug. Chem. 20, 2270-2277; [Ref.5] Miranda, F. F. et al. (2011), Biosens. Bioelectron. 26, 4184-4190; [Ref.6] Behar G.et al. (2013), Protein Eng Des Sel. 26(4):267-75. (authors)

  9. Antibody discovery: sourcing of monoclonal antibody variable domains.

    Science.gov (United States)

    Strohl, William R

    2014-03-01

    Historically, antibody variable domains for therapeutic antibodies have been sourced primarily from the mouse IgG repertoire, and typically either chimerized or humanized. More recently, human antibodies from transgenic mice producing human IgG, phage display libraries, and directly from human B lymphocytes have been used more broadly as sources of antibody variable domains for therapeutic antibodies. Of the total 36 antibodies approved by major maket regulatory agencies, the variable domain sequences of 26 originate from the mouse. Of these, four are marketed as murine antibodies (of which one is a mouse-rat hybrid IgG antibody), six are mouse-human chimeric antibodies, and 16 are humanized. Ten marketed antibodies have originated from human antibody genes, three isolated from phage libraries of human antibody genes and seven from transgenic mice producing human antibodies. Five antibodies currently in clinical trials have been sourced from camelids, as well as two from non-human primates, one from rat, and one from rabbit. Additional sources of antibody variable domains that may soon find their way into the clinic are potential antibodies from sharks and chickens. Finally, the various methods for retrieval of antibodies from humans, mouse and other sources, including various display technologies and amplification directly from B cells, are described. PMID:24168292

  10. Monoclonal Antibodies for Lipid Management.

    Science.gov (United States)

    Feinstein, Matthew J; Lloyd-Jones, Donald M

    2016-07-01

    In recent years, biochemical and genetic studies have identified proprotein convertase subtilisin/kexin type 9 (PCSK9) as a major mediator of low-density lipoprotein cholesterol (LDL-c) levels and thereby a potential novel target for reducing risk of coronary heart disease (CHD). These observations led to the development of PCSK9 inhibitors, which lower LDL-c levels more than any other non-invasive lipid-lowering therapy presently available. The PCSK9 inhibitors furthest along in clinical trials are subcutaneously injected monoclonal antibodies. These PCSK9 inhibitors have demonstrated LDL-c-lowering efficacy with acceptable safety in phase III clinical trials and may offer a useful therapy in addition to maximally tolerated HMG-CoA reductase inhibitors (statins) in certain patient groups. Longer-term data are required to ensure sustained efficacy and safety of this new class of medications. This review provides an overview of the biology, genetics, development, and clinical trials of monoclonal antibodies designed to inhibit PCSK9. PMID:27221501

  11. Development of monoclonal antibodies suitable for rabies virus antibody and antigen detection.

    Science.gov (United States)

    Chander, Vishal; Singh, R P; Verma, P C

    2012-12-01

    The control of an infectious viral disease as rabies is made easier by rapid and accurate diagnosis. Successful rabies prophylaxis is dependent upon the active immunization with vaccine along with passive administration of rabies virus neutralizing antibodies which together clear the virus before widespread infection of central nervous system occurs. The present study aimed at the development of monoclonal antibodies (MAbs) suitable for rabies virus antibody and antigen detection. For the production of rabies specific MAbs, immunization of Swiss albino mice with a commercially available vaccine was done and Polyethylene glycol mediated fusion of spleenocytes with myeloma cells was performed. The positive clones were selected on the basis of distinct reactivity by cell Enzyme linked immunosorbent assay and fluorescence in Indirect Fluorescent antibody test. The positive clones obtained were subjected to single cell cloning by limiting dilution method. The reactive clones were further titrated and employed for virus titration and virus neutralization. The neutralizing activity was evaluated using Fluorescence Activated Cell Sorter technique. Three MAb clones showed a distinct percent inhibition in the presence of positive serum. One of the MAb clone No. 5C3 was relatively more specific in detecting rabies antibodies and also found suitable for competitive ELISA to assess the antibody level in vaccinated subjects. PMID:24293819

  12. Detection of antitrophoblast antibodies in the sera of patients with anticardiolipin antibodies and fetal loss.

    Science.gov (United States)

    McCrae, K R; DeMichele, A M; Pandhi, P; Balsai, M J; Samuels, P; Graham, C; Lala, P K; Cines, D B

    1993-11-01

    Women with anticardiolipin antibodies (ACLA) are at increased risk for fetal loss. One potential explanation for this outcome is that sera from these individuals contain antibodies reactive with trophoblast cells, which are involved in the establishment of the uteroplacental vasculature and maintenance of placental blood fluidity. To examine this hypothesis, we compared the incidence of trophoblast-reactive antibodies in 27 patients with ACLA and a history of fetal loss with that in 29 normal pregnant women. Sera from 20 patients, but only one control, contained trophoblast-reactive antibodies (P trophoblast cells. In most cases, sera from which ACLA were adsorbed by cardiolipin-containing liposomes maintained reactivity against cells. In addition, patient Ig fractions immunoprecipitated an approximately 62-kD protein from the trophoblast cell surface, stimulated the release of arachidonic acid and thromboxane A2 by trophoblasts, and inhibited the binding of prourokinase to trophoblast urokinase receptors. These observations show that sera from women with ACLA and a history of fetal loss contain antitrophoblast antibodies. These antibodies may be serologically distinct from ACLA, and may contribute to the pathogenesis of fetal demise. PMID:7693045

  13. Radiolabelled antibodies in imaging

    International Nuclear Information System (INIS)

    Recent technological advances make it possible to produce pure (monoclonal) antibodies in unlimited quantities without the need for continuous immunization of animals and to label these antibodies with a variety of radionuclides which can be traced by single-photon computed tomography. An outline review of the state of the art is presented, with particular reference to the imaging of myocardial infarcts and to tumour imaging studies using labelled monoclonal antibodies (sup(99m)Tc and 125I). Lengthy bibliography. (U.K.)

  14. Isolation of Potent CGRP Neutralizing Antibodies Using Four Simple Assays.

    Science.gov (United States)

    Neal, Frances; Arnold, Joanne; Rossant, Christine J; Podichetty, Sadhana; Lowne, David; Dobson, Claire; Wilkinson, Trevor; Colley, Caroline; Howes, Rob; Vaughan, Tristan J

    2016-01-01

    Calcitonin gene-related peptide (CGRP) is a small neuropeptide and a potent vasodilator that is widely associated with chronic pain and migraine. An antibody that inhibits CGRP function would be a potential therapeutic for treatment of these disorders. Here we describe the isolation of highly potent antibodies to CGRP from phage and ribosome display libraries and characterization of their epitope, species cross-reactivity, kinetics, and functional activity. Homogenous time-resolved fluorescence (HTRF) binding assays identified antibodies with the desired species cross-reactivity from naïve libraries, and HTRF epitope competition assays were used to characterize and group scFv by epitope. The functional inhibition of CGRP and species cross-reactivity of purified scFv and antibodies were subsequently confirmed using cAMP assays. We show that epitope competition assays could be used as a surrogate for functional cell-based assays during affinity maturation, in combination with scFv off-rate ranking by biolayer interferometry (BLI). This is the first time it has been shown that off-rate ranking can be predictive of functional activity for anti-CGRP antibodies. Here we demonstrate how, by using just four simple assays, diverse panels of antibodies to CGRP can be identified. These assay formats have potential utility in the identification of antibodies to other therapeutic targets. PMID:26450103

  15. Neutralizing antibodies decrease the envelope fluidity of HIV-1

    International Nuclear Information System (INIS)

    For successful penetration of HIV-1, the formation of a fusion pore may be required in order to accumulate critical numbers of fusion-activated gp41 with the help of fluidization of the plasma membrane and viral envelope. An increase in temperature to 40 oC after viral adsorption at 25 oC enhanced the infectivity by 1.4-fold. The enhanced infectivity was inhibited by an anti-CXCR4 peptide, T140, and anti-V3 monoclonal antibodies (0.5β and 694/98-D) by post-attachment neutralization, but not by non-neutralizing antibodies (670-30D and 246-D) specific for the C5 of gp120 and cluster I of gp41, respectively. Anti-HLA-II and an anti-HTLV-I gp46 antibody, LAT27, neutralized the molecule-carrying HIV-1C-2(MT-2). The anti-V3 antibodies suppressed the fluidity of the HIV-1C-2 envelope, whereas the non-neutralizing antibodies did not. The anti-HLA-II antibody decreased the envelope fluidity of HIV-1C-2(MT-2), but not that of HIV-1C-2. Therefore, fluidity suppression by these antibodies represents an important neutralization mechanism, in addition to inhibition of viral attachment

  16. P-fimbriae in the presence of anti-PapA antibodies: new insight of antibodies action against pathogens

    Science.gov (United States)

    Mortezaei, Narges; Singh, Bhupender; Bullitt, Esther; Uhlin, Bernt Eric; Andersson, Magnus

    2013-12-01

    Uropathogenic strains of Escherichia coli establish urinary tract infections by attaching to host epithelial cells using adhesive organelles called fimbriae. Fimbriae are helix-like structures with a remarkable adaptability, offering safeguarding for bacteria exposed to changing fluid forces in the urinary tract. We challenged this property of P-fimbriae by cross-linking their subunits with shaft-specific antibodies and measuring the corresponding force response at a single organelle level. Our data show compromised extension and rewinding of P-fimbriae in the presence of antibodies and reduced fimbrial elasticity, which are important properties of fimbriae contributing to the ability of bacteria to cause urinary tract infections. The reduced elasticity found by cross-linking fimbrial subunits could thus be another assignment for antibodies; in addition to marking bacteria as foreign, antibodies physically compromise fimbrial function. We suggest that our assay and results will be a starting point for further investigations aimed at inhibiting sustained bacterial adhesion by antibodies.

  17. Anti-idiotypes against a monoclonal anti-haloperidol antibody bind to dopamine receptor

    International Nuclear Information System (INIS)

    Anti-idiotypic antibodies were raised in rabbits by immunization with a monoclonal anti-haloperidol antibody. Some of these anti-idiotypic antibodies bind in a concentration dependent manner to bovine striatal membranes. Following affinity purification, these antibodies inhibit haloperidol binding to striatal membranes and deplete [3H]-spiperone binding sites from a solubilized preparation of striatal membranes. It is thus concluded that these anti-idiotypic antibodies are an internal image of haloperidol and as such can interact with D2-dopamine receptors

  18. Anti-sulfotyrosine antibodies

    Science.gov (United States)

    Bertozzi, Carolyn R.; Kehoe, John; Bradbury, Andrew M.

    2009-09-15

    The invention provides anti-sulfotyrosine specific antibodies capable of detecting and isolating polypeptides that are tyrosine-sulfated. The sulfotyrosine antibodies and antibody fragments of the invention may be used to discriminate between the non-sulfated and sulfated forms of such proteins, using any number of immunological assays, such ELISAs, immunoblots, Western Blots, immunoprecipitations, and the like. Using a phage-display system, single chain antibodies (scFvs) were generated and screened against tyrosine-sulfated synthetic peptide antigens, resulting in the isolation of scFvs that specifically recognize sulfotyrosine-containing peptides and/or demonstrate sulfotyrosine-specific binding in tyrosine sulfated proteins. The VH and VL genes from one such sulfotyrosine-specific scFv were employed to generate a full length, sulfotyrosine-specific immunoglobulin.

  19. HIV Antibody Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? HIV Antibody and HIV Antigen (p24) Share this page: Was this page helpful? Also known as: HIV Screening Tests; AIDS Test; AIDS Screen; HIV Serology; ...

  20. Antinuclear antibody panel

    Science.gov (United States)

    ... blood may be due to: Chronic liver disease Collagen vascular disease Drug-induced lupus erythematosus Myositis (inflammatory muscle disease) ... Saunders; 2011:chap 51. Read More Antibody Arthritis Collagen vascular disease Drug-induced lupus erythematosus Liver disease Scleroderma Systemic ...

  1. PRODUCTION OF MONOCLONAL ANTIBODIES

    Directory of Open Access Journals (Sweden)

    TOLKOVA E.S.

    2015-01-01

    Full Text Available The article considers the use of monoclonal antibodies in immunotherapy and immunodiagnostics of oncological diseases and their production using hybridoma technolody with flow diagram and technological scheme of manufacturing process

  2. PRODUCTION OF MONOCLONAL ANTIBODIES

    OpenAIRE

    TOLKOVA E.S.

    2015-01-01

    The article considers the use of monoclonal antibodies in immunotherapy and immunodiagnostics of oncological diseases and their production using hybridoma technolody with flow diagram and technological scheme of manufacturing process

  3. DNA repair and DNA antibodies during experimental mycoplasma arthritis

    International Nuclear Information System (INIS)

    To clarify the pathogenesis of a mycoplasma induced arthritis in rats, investigations were carried out on the influence of mycoplasma infection on DNA repair and the occurrence of DNA antibodies. During acute and subacute stage of the experimentally induced arthritis an inhibition of DNA repair could be observed. Besides the results indicated a correlation between reduced or inhibited DNA repair and the appearance of DNA antibodies could be found. The DNA-repair behaviour after the mycoplasma infection was compared with the influence of γ-irradiation

  4. Expression of Recombinant Antibodies

    OpenAIRE

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

    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 transg...

  5. Changes in the Properties of the Thyrotropin Receptor Antibody in Patients with Graves’ Disease after Radioiodine Treatment

    OpenAIRE

    Cho, Bo Youn; Shong, Young Kee; Chung, June-Key; Lee, Myung Chul; Lee, Hong Kyu; Koh, Chang-Soon; Min, Hun Ki

    1990-01-01

    We investigated the effect of a single dose of 131I upon thyrotropin receptor antibodies (TRAb) in 21 patients with Graves’ disease. The thyrotropin receptor antibodies were assessed by parallel measurements of thyrotropin binding inhibitor immunoglobulin (TBII), thyroid stimulating antibody (TSAb) and thyroid stimulation blocking antibody (TSBAb) in serum by radoreceptor assay, stimulation of adenlate cyclase and inhibition of TSH-stimulated adenylate cyclase activation in FRTL-5 cells, resp...

  6. Fab-mediated binding of drug-dependent antibodies to platelets in quinidine- and quinine-induced thrombocytopenia.

    OpenAIRE

    Christie, D J; Mullen, P C; Aster, R H

    1985-01-01

    Platelets coated with quinine- or quinidine-induced antibodies form rosettes around protein A-Sepharose beads and normal platelets form rosettes about protein A-Sepharose beads coated with these antibodies. These reactions occurred only in the presence of sensitizing drug. Platelets also formed rosettes about protein A-Sepharose beads coated with an anti-PIA1 antibody, but drug was not required. Formation of rosettes between antibody-coated platelets and protein A-Sepharose was inhibited by F...

  7. Enhancing blockade of Plasmodium falciparum erythrocyte invasion: assessing combinations of antibodies against PfRH5 and other merozoite antigens.

    Directory of Open Access Journals (Sweden)

    Andrew R Williams

    Full Text Available No vaccine has yet proven effective against the blood-stages of Plasmodium falciparum, which cause the symptoms and severe manifestations of malaria. We recently found that PfRH5, a P. falciparum-specific protein expressed in merozoites, is efficiently targeted by broadly-neutralizing, vaccine-induced antibodies. Here we show that antibodies against PfRH5 efficiently inhibit the in vitro growth of short-term-adapted parasite isolates from Cambodia, and that the EC(50 values of antigen-specific antibodies against PfRH5 are lower than those against PfAMA1. Since antibody responses elicited by multiple antigens are speculated to improve the efficacy of blood-stage vaccines, we conducted detailed assessments of parasite growth inhibition by antibodies against PfRH5 in combination with antibodies against seven other merozoite antigens. We found that antibodies against PfRH5 act synergistically with antibodies against certain other merozoite antigens, most notably with antibodies against other erythrocyte-binding antigens such as PfRH4, to inhibit the growth of a homologous P. falciparum clone. A combination of antibodies against PfRH4 and basigin, the erythrocyte receptor for PfRH5, also potently inhibited parasite growth. This methodology provides the first quantitative evidence that polyclonal vaccine-induced antibodies can act synergistically against P. falciparum antigens and should help to guide the rational development of future multi-antigen vaccines.

  8. Enzyme-linked immunosorbent assay (ELISA for measles antibody: a comparison with haemagglutination inhibition, immunofluorescence and plaque neutralization tests Reação imunoenzimática (ELISA para detecção de anticorpos para o vírus do sarampo: comparação com reações de inibição da hema-glutinação, imunofluorescência indireta e neutralização de placas

    Directory of Open Access Journals (Sweden)

    Vanda Akico Ueda Fick de Souza

    1991-02-01

    Full Text Available An enzyme-linked immunosorbent assay (ELISA for measles antibodies was compared with Plaque Neutralization (PRN, Haemagglutination inhibition (HI and Fluorescent antibody (IFA tests in 181 sera from vaccinated children and umbilical cord. Of 179 positive samples by the sensitive PRN, only two, with titers of 8, were negative by ELISA (copositivity of 98.9%. IFA and HI presented, respectively, copo-sitivities of 93.3% and 82.7%. The ELISA presented a high sensitivity as well as a good reproducibility and represents an alternative for the time consuming PRN for detection of low measles antibodies.A reação imunoenzimática (ELISA para determinação de anticorpos para o vírus do sarampo foi comparada com a reação de neutralização de placas (RNP, inibição da hemaglutinação (RIH e imunofluorescência indireta (RIF. Das 179 amostras positivas pela RNP, somente 2, com títulos iguais a 8, se apresentaram negativas por ELISA (copositividade de 98.9%. A RIF e RIH apresentaram, respectivamente, copositividade de 93.3 e 82.7%. ELISA apresentou sensibilidade equivalente à complexa RNP, boa reprodutibilidade e representa uma alternativa para a detecção de baixos títulos de anticorpos contra o sarampo.

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

    OpenAIRE

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

    2005-01-01

    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 single-domain antibody fragments (VHHs) can be extended to very harsh conditions, such as the presence of shampoo containing nonionic and anionic surfactants. We selected several VHHs that bind to the cell wall ...

  10. Isolation of Llama Antibody Fragments for Prevention of Dandruff by Phage Display in Shampoo

    OpenAIRE

    2005-01-01

    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 single-domain antibody fragments (VHHs) can be extended to very harsh conditions, such as the presence of shampoo containing nonionic and anionic surfactants. We selected several VHHs that bind to the cell wall ...

  11. Differentiation between monoclonal antibody - defined antigens on a human osteogenic sarcoma cell line (791-T) and Tumor-localizing properties of the anti-791T/36 antibody

    International Nuclear Information System (INIS)

    Two monoclonal antibodies (anti-791T/36 and anti-791T/48) prepared against an osteogenic sarcoma cell line (791T) following xenogeneic immunization, reacted against the immunizing tumor, but not against normal cells from the tumor-donor, using an indirect 125I-protein A binding assay. Both antibodies cross-reacted with a small number of other osteogenic sarcomas and a few unrelated cell lines from an extensive panel, but the specificity of these cross-reactions was different. Both antibodies were labelled with 125I to detect direct binding to target cells, and the specificity of their reactivity was essentially identical to that observed in the indirect assay. Direct binding of each labelled antibody was inhibited by pretreating target cells with its unlabelled counterpart, but the two antibodies could not inhibit each other. The binding of anti-791T/36 was also not inhibited by pretreating the target cells with sera from the 791-T-tumor donor, which were shown to contain antibody reacting with the autochthonous tumor. It is concluded that 791T has two distinct tumor-associated antigens recognized by the monoclonal antibodies, and furthermore that at least one of these antigens is independent of those recognized by the patient from which the tumor cell line was derived. The efficacy of anti-791T/36 antibody labelled with radioactive iodine was demonstrated for localizing tumor deposits growing in immunodeprived mice. (author)

  12. Pulmonary biology of anti-interleukin 5 antibodies

    Directory of Open Access Journals (Sweden)

    RW Egan

    1997-12-01

    Full Text Available Interleukin 5 (IL-5 is a critical cytokine for the maturation of eosinophil precursors to eosinophils in the bone marrow and those eosinophils then accumulate in the lungs during asthma. We have studied anti IL-5 antibodies on allergic responses in mice, guinea pigs and monkeys and are extending this experiment into humans with a humanized antibody. In a monkey model of pulmonary inflammation and airway hyperreactivity, we found that the TRFK-5 antibody blocked both responses for three months following a single dose of 0.3 mg/kg, i.v. This antibody also blocked lung eosinophilia in mice by inhibiting release from the bone marrow. To facilitate multiple dosing and to reduce immunogenicity in humans, we prepared Sch 55700, a humanized antibody against IL-5. Sch 55700 was also active against lung eosinophilia in allergic monkeys and mice and against pulmonary eosinophilia and airway hyperresponsiveness in guinea pigs. Furthermore, as opposed to steroids, Sch 55700 did not cause immunosuppression in guinea pigs. Studies with this antibody in humans will be critical to establishing the therapeutic potential of IL-5 inhibition.

  13. Functional Analysis of Neutralizing Antibodies against Clostridium perfringens Epsilon-Toxin▿

    OpenAIRE

    McClain, Mark S.; Cover, Timothy L.

    2007-01-01

    The Clostridium perfringens epsilon-toxin causes a severe, often fatal illness (enterotoxemia) characterized by cardiac, pulmonary, kidney, and brain edema. In this study, we examined the activities of two neutralizing monoclonal antibodies against the C. perfringens epsilon-toxin. Both antibodies inhibited epsilon-toxin cytotoxicity towards cultured MDCK cells and inhibited the ability of the toxin to form pores in the plasma membranes of cells, as shown by staining cells with the membrane-i...

  14. Monoclonal antibodies against human placental glutathione transferase (class pi).

    Science.gov (United States)

    Massoud, R; Lo Bello, M; De Stefano, E; Molino, A; Zelaschi, D; Federici, G

    1991-02-01

    Five monoclonal antibodies (MAbs) were produced in a mouse hybridoma system against human placental glutathione transferase (GST pi). Four of these monoclonal antibodies, named 461 to 464, were of immunoglobulin G class, whereas the monoclonal antibody 465 was of IgA class. All these MAbs specifically recognized the glutathione transferase from human placenta (class pi) showing no cross reactivity against the basic and the neutral forms of GST from human liver. When each MAb was incubated with the GST pi, no inhibition of enzymatic activity towards 1-chloro-2,4-dinitrobenzene was observed except for MAb 465 which showed a slight inhibition to a serial dilution of 1:128. PMID:1709614

  15. Treatment of Antibody-Mediated Rejection in Kidney Transplantation

    Directory of Open Access Journals (Sweden)

    Magdalena Durlik

    2013-07-01

    Full Text Available Antibody-mediated rejection (AMR is a relatively rare but severe complication in kidney transplantation associated with increased risk of graft loss. Diagnosis of acute and chronic AMR is based on typical histological hallmarks, deposition of C4d in peritubular capillaries and presence of donor-specific antibodies (DSA. Many novel and attractive treatment options have become available in recent years: antibody removal and production inhibition (plasmapheresis, IVIg, B cell depletion (rituximab, plasma cell depletion and apoptosis (bortezomib, and complement activation inhibition (eculizumab. Standard therapy is based on PP and IVIg. Preliminary results with new agents are encouraging but require randomised clinical trials and long-term follow-up.

  16. Detection of B-lymphocytes secreting antibodies to Dermatophagoides antigens

    DEFF Research Database (Denmark)

    Sparholt, S H; Barington, T; Schou, C

    1991-01-01

    An enzyme-linked immunospot assay (ELI-spot assay) has been established to count individual cells secreting antibodies to Dermatophagoides spp. allergens. Initial optimization of the assay was performed using Der p I-specific murine hybridoma cell lines. Inhibition with soluble purified allergen ...

  17. Antibody to porcine parvovirus in warthog (Phacochoerus aethiopicus).

    Science.gov (United States)

    Thomson, G R; Peenze, I

    1980-03-01

    Haemagglutination inhibiting antibody to porcine parvovirus was shown to be widespread in all but one of the warthog populations sampled from South Africa and Zimbabwe Rhodesia. In some instances titres as high as greater than or equal to 1/20 000 were detected. PMID:7454234

  18. A game of numbers: the stoichiometry of antibody-mediated neutralization of flavivirus infection

    Science.gov (United States)

    Pierson, Theodore C.; Diamond, Michael S.

    2016-01-01

    The humoral response contributes to the protection against viral pathogens. Although antibodies have the potential to inhibit viral infections via several mechanisms, an ability to neutralize viruses directly may be particularly important. Neutralizing antibody titers are commonly used as predictors of protection from infection, especially in the context of vaccine responses and immunity. Despite the simplicity of the concept, how antibody binding results in virus inactivation is incompletely understood despite decades of research. Flaviviruses have been an attractive system in which to seek a structural and quantitative understanding of how antibody interactions with virions modulate infection because of the contribution of antibodies to both protection and pathogenesis. This review will present a stoichiometric model of antibody-mediated neutralization of flaviviruses and discuss how these concepts can inform the development of vaccines and antibody-based therapeutics. PMID:25595803

  19. Prediction of antibody persistency from antibody titres to natalizumab

    DEFF Research Database (Denmark)

    Jensen, Poul Erik H; Koch-Henriksen, Nils; Sellebjerg, Finn; Sørensen, Per S

    2012-01-01

    In a subgroup of patients with multiple sclerosis natalizumab therapy causes generation of anti-natalizumab antibodies that may be transient or persistent. It is recommended to discontinue natalizumab therapy in persistently antibody-positive patients.......In a subgroup of patients with multiple sclerosis natalizumab therapy causes generation of anti-natalizumab antibodies that may be transient or persistent. It is recommended to discontinue natalizumab therapy in persistently antibody-positive patients....

  20. Characterization and epitope mapping of a new panel of monoclonal antibodies to estradiol receptor.

    Science.gov (United States)

    Abbondanza, C; de Falco, A; Nigro, V; Medici, N; Armetta, I; Molinari, A M; Moncharmont, B; Puca, G A

    1993-01-01

    A new panel of monoclonal antibodies to the calf uterus estrogen receptor was prepared. Thirteen antibodies were characterized for their isotype and for the affinity for the antigen. These antibodies recognize the human receptor and can be used in Western blot analysis. The location of the epitopes was mapped on the antigen structure using synthetic fragments of estrogen receptor, and it was possible to group the antibodies in five groups. Many antibodies were useful for the purification of estrogen receptor from tissue extracts by immunoaffinity chromatography. The reciprocal inhibition of the antibodies for the antigen binding was measured with an immunoadsorption assay. This was maximal and symmetrical for antibody pairs within the same group, but was incomplete and, in some instances, asymmetrical between pairs of antibodies from different groups. One antibody was able to inhibit the estrogen receptor-DNA interaction, whereas two others were unable to recognize the receptor-DNA complexes. This new panel of antibodies is a useful addition to the existing tools for studying structure and function of the estrogen receptor. PMID:7679226

  1. Prediction of Antibody Epitopes

    DEFF Research Database (Denmark)

    Nielsen, Morten; Marcatili, Paolo

    2015-01-01

    self-proteins. Given the sequence or the structure of a protein of interest, several methods exploit such features to predict the residues that are more likely to be recognized by an immunoglobulin.Here, we present two methods (BepiPred and DiscoTope) to predict linear and discontinuous antibody...

  2. Monoclonal antibodies in myeloma

    DEFF Research Database (Denmark)

    Sondergeld, P.; van de Donk, N. W. C. J.; Richardson, P. G.;

    2015-01-01

    The development of monoclonal antibodies (mAbs) for the treatment of disease goes back to the vision of Paul Ehrlich in the late 19th century; however, the first successful treatment with a mAb was not until 1982, in a lymphoma patient. In multiple myeloma, mAbs are a very recent and exciting add...

  3. Red Blood Cell Antibody Identification

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? RBC Antibody Identification Share this page: Was this page helpful? Also known as: Alloantibody Identification; Antibody ID, RBC; RBC Ab ID Formal name: Red ...

  4. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test ... Normally, there are no antibodies against insulin in your blood. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or ...

  5. The Art of Making Antibodies.

    Science.gov (United States)

    Headon, Denis R.

    1986-01-01

    Provides background information for teachers on the nature and production of antibodies. Points out that the production of monoclonal antibodies blends the malignant with the beneficial to create a medical tool of exciting potential. (JN)

  6. Lupus anticoagulants and antiphospholipid antibodies

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000547.htm Lupus anticoagulants and antiphospholipid antibodies To use the sharing features on this page, please enable JavaScript. Lupus anticoagulants are antibodies against substances in the lining ...

  7. Recombinant antibodies and tumor targeting

    OpenAIRE

    Sheikholvaezin, Ali

    2006-01-01

    Different antibody derived constructs are rapidly advancing as putative tools for treatment of malignant diseases. Antibody engineering has added significant new technologies to modify size, affinities, solubility, stability and biodistribution properties for immunoconjugates. In the present thesis, the aim was to increase our knowledge on how new recombinant antibodies could be tailored to optimize localization to experimental tumors in mice. One hybridoma, producing the monoclonal antibody ...

  8. Antibody Engineering and Therapeutics Conference

    OpenAIRE

    Larrick, James W; Parren, Paul WHI; Huston, James S; Plückthun, Andreas; Bradbury, Andrew; Tomlinson, Ian M; Chester, Kerry A.; Burton, Dennis R.; Adams, Gregory P; Weiner, Louis M.; Scott, Jamie K; Alfenito, Mark R; Veldman, Trudi; Reichert, Janice M

    2013-01-01

    The Antibody Engineering and Therapeutics conference, which serves as the annual meeting of The Antibody Society, will be held in Huntington Beach, CA from Sunday December 8 through Thursday December 12, 2013. The scientific program will cover the full spectrum of challenges in antibody research and development, and provide updates on recent progress in areas from basic science through approval of antibody therapeutics. Keynote presentations will be given by Leroy Hood (Institute of System Bi...

  9. 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.

  10. A monoclonal antibody (8H3) that binds to rat T lineage cells and augments in vitro proliferative responses

    OpenAIRE

    1990-01-01

    A murine monoclonal antibody, designated 8H3, recognizes a cell surface antigen expressed exclusively on rat T lineage cells. 8H3 antibody immunoprecipitated 180-, 120-, and 90-kD components from rat thymocytes as well as splenic T cells under nonreducing conditions. 8H3 antibody specifically inhibited the binding of thymocytes to fibronectin. Furthermore, binding of rat thymocytes to immobilized synthetic peptide Gly-Arg-Gly-Asp-Ser-Pro-Cys-BSA was inhibited by 8H3 antibody as was Gly-Arg-Gl...

  11. Radiolabeled antibodies as imaging agents

    International Nuclear Information System (INIS)

    The author gives a survey of the progress made on radioimmunodetection. Antibodies may now be more readily used in scintigraphy as a result of the development of labeling methods that apply more suitable radionuclides without significant loss of the antigen-binding activity. Antibodies to tumor-specific or tumor-associated antigens can now be produced in large quantities by monoclonal antibody technology

  12. Antibody mimetics: promising complementary agents to animal-sourced antibodies.

    Science.gov (United States)

    Baloch, Abdul Rasheed; Baloch, Abdul Wahid; Sutton, Brian J; Zhang, Xiaoying

    2016-01-01

    Despite their wide use as therapeutic, diagnostic and detection agents, the limitations of polyclonal and monoclonal antibodies have inspired scientists to design the next generation biomedical agents, so-called antibody mimetics that offer many advantages over conventional antibodies. Antibody mimetics can be constructed by protein-directed evolution or fusion of complementarity-determining regions through intervening framework regions. Substantial progress in exploiting human, butterfly (Pieris brassicae) and bacterial systems to design and select mimetics using display technologies has been made in the past 10 years, and one of these mimetics [Kalbitor® (Dyax)] has made its way to market. Many challenges lie ahead to develop mimetics for various biomedical applications, especially those for which conventional antibodies are ineffective, and this review describes the current characteristics, construction and applications of antibody mimetics compared to animal-sourced antibodies. The possible limitations of mimetics and future perspectives are also discussed. PMID:25264572

  13. Fcγ receptor-mediated inflammation inhibits axon regeneration.

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    Full Text Available Anti-glycan/ganglioside antibodies are the most common immune effectors found in patients with Guillain-Barré Syndrome, which is a peripheral autoimmune neuropathy. We previously reported that disease-relevant anti-glycan autoantibodies inhibited axon regeneration, which echo the clinical association of these antibodies and poor recovery in Guillain-Barré Syndrome. However, the specific molecular and cellular elements involved in this antibody-mediated inhibition of axon regeneration are not previously defined. This study examined the role of Fcγ receptors and macrophages in the antibody-mediated inhibition of axon regeneration. A well characterized antibody passive transfer sciatic nerve crush and transplant models were used to study the anti-ganglioside antibody-mediated inhibition of axon regeneration in wild type and various mutant and transgenic mice with altered expression of specific Fcγ receptors and macrophage/microglia populations. Outcome measures included behavior, electrophysiology, morphometry, immunocytochemistry, quantitative real-time PCR, and western blotting. We demonstrate that the presence of autoantibodies, directed against neuronal/axonal cell surface gangliosides, in the injured mammalian peripheral nerves switch the proregenerative inflammatory environment to growth inhibitory milieu by engaging specific activating Fcγ receptors on recruited monocyte-derived macrophages to cause severe inhibition of axon regeneration. Our data demonstrate that the antibody orchestrated Fcγ receptor-mediated switch in inflammation is one mechanism underlying inhibition of axon regeneration. These findings have clinical implications for nerve repair and recovery in antibody-mediated immune neuropathies. Our results add to the complexity of axon regeneration in injured peripheral and central nervous systems as adverse effects of B cells and autoantibodies on neural injury and repair are increasingly recognized.

  14. Production and Characterization of Monoclonal Antibodies of Shrimp White Spot Syndrome Virus Envelope Protein VP28

    Institute of Scientific and Technical Information of China (English)

    Wan-gang GU; Jun-fa YUAN; Ge-lin XU; Li-juan LI; Ni LIU; Cong ZHANG; Jian-hong ZHANG; Zheng-li SHI

    2007-01-01

    BALB/c mice were immunized with purified White spot syndrome virus (WSSV).Six monoclonal antibody cell lines were selected by ELISA with VP28 protein expressed in E.coll in vitro neutralization experiments showed that 4 of them could inhibit the virus infection in crayfish.Westernblot suggested that all these monoclonal antibodies were against the conformational structure of VP28.The monoclonal antibody 7B4 was labeled with colloidal gold particles and used to locate the VP28 on virus envelope by immunogold labeling.These monoclonal antibodies could be used to develop immunological diagnosis methods for WSSV infection.

  15. Capture ELISA for IgM antibodies against Plasmodium falciparum glutamate rich protein

    DEFF Research Database (Denmark)

    Dziegiel, M; Borre, Mette; Petersen, E; Högh, B; Jepsen, S; Vuust, J; Axelsen, N

    1992-01-01

    -galactosidase fusion protein and used as antigen after purification and biotinylation. Specific IgM antibodies were found in 51% (39/77) of sera from adult Liberians immune to malaria. The binding of IgM antibodies was specific for the malaria portion of the fusion protein and no cross-reactivity was found in sera...... from patients with IgM antibodies due to other diseases. Inhibition studies with a fusion protein containing amino acid residues 816-1134 (GLURP816-1134) representing the carboxy-terminal repeat region suggested a different use of epitopes for IgM antibodies in different individuals....

  16. Protective Antibodies against Placental Malaria and Poor Outcomes during Pregnancy, Benin

    DEFF Research Database (Denmark)

    Ndam, Nicaise Tuikue; Denoeud-Ndam, Lise; Doritchamou, Justin;

    2015-01-01

    . Antibody-mediated immunity to placental malaria is acquired during successive pregnancies, but the target of VAR2CSA-specific protective antibodies is unclear. We assessed VAR2CSA-specific antibodies in pregnant women and analyzed their relationships with protection against placental infection, preterm...... birth, and low birthweight. Antibody responses to the N-terminal region of VAR2CSA during early pregnancy were associated with reduced risks for infections and low birthweight. Among women infected during pregnancy, an increase in CSA binding inhibition was associated with reduced risks for placental...

  17. Monoclonal antibodies to Pneumocystis carinii

    DEFF Research Database (Denmark)

    Kovacs, J A; Halpern, J L; Lundgren, B; Swan, J C; Parrillo, J E; Masur, H

    1989-01-01

    To increase understanding of the antigenic structure of Pneumocystis carinii, we developed monoclonal antibodies to rat and human P. carinii. The specificity of the antibodies was demonstrated by immunofluorescence and immunoblot studies. Only one of five monoclonal antibodies to rat P. carinii...... reacted with human P. carinii, and none of four monoclonal antibodies to human P. carinii reacted with rat P. carinii. Two antibodies to human P. carinii reacted by immunofluorescence with only one human P. carinii isolate. Immunoblot studies identified major antigens of rat P. carinii with molecular...

  18. [Antibody therapy for Alzheimer's disease].

    Science.gov (United States)

    Tabira, Takeshi; Matsumoto, Shin-Ei; Jin, Haifeng

    2011-11-01

    In order to avoid Abeta-induced autoimmune encephalitis, several monoclonal and polyclonal antibodies are in clinical trials. These are bapineuzumab, solanezumab, ponezumab, gantenerumab, BAN2401, gammaguard and octagam. Since each antibody has a different antigen epitope of Abeta, anti-amyloid activities are different. It is unknown which antibody is effective for Alzheimer disease, and we must wait for the result of clinical trials. Some patients who developed tissue amyloid plaque immuno-reactive (TAPIR) antibody showed slower decline after AN-1792 vaccination. We developed TAPIR-like monoclonal antibody, which was found to react with Abeta oligomers preferentially. PMID:22277519

  19. Tabhu: tools for antibody humanization

    DEFF Research Database (Denmark)

    Olimpieri, Pier Paolo; Marcatili, Paolo; Tramontano, Anna

    2015-01-01

    and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps......Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can...

  20. Monoclonal antibody as radiopharmaceutical

    International Nuclear Information System (INIS)

    The purification of anti-CEA monoclonal antibody 4C11 belonging to IgG sub(2a) subclass from mouse ascitis, donated by Ludwig Institute, Brazil was developed. The fragmentation of purified IgG sub(2a) by pepsin digestion and analytical studies by polyacrilamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) were done as preliminary assessment for their specific application in immunoscintigraphy. (author)

  1. Anticardiolipin antibodies in leptospirosis.

    OpenAIRE

    Rugman, F P; Pinn, G.; Palmer, M. F.; Waite, M.; Hay, C. R.

    1991-01-01

    The clinical course and serology of 16 cases of leptospirosis in an area with an unusually high endemic infection rate were studied to gain further insight into the pathology of the secondary immune phase that is typical of the disease. IgG anticardiolipin antibody concentrations were measured by immunoassay and found to be increased in eight serologically confirmed cases with severe complicated disease, compared with eight patients with relatively uncomplicated leptospirosis who had IgG anti...

  2. A monoclonal antibody against leptin.

    Science.gov (United States)

    Mahmoudian, Jafar; Jeddi-Tehrani, Mahmood; Bayat, Ali Ahmad; Mahmoudi, Ahmad Reza; Vojgani, Yasaman; Tavangar, Banafsheh; Hadavi, Reza; Zarei, Saeed

    2012-10-01

    Leptin is an important protein that regulates energy storage and homeostasis in humans and animals. Leptin deficiency results in various abnormalities such as diabetes, obesity, and infertility. Producing a high affinity monoclonal antibody against human leptin provides an important tool to monitor and trace leptin function in different biological fluids. In this study, recombinant human leptin was conjugated to KLH and injected into mice. After immunization, mouse myeloma SP2/0 cells were fused with murine splenocytes followed by selection of antibody-producing hybridoma cells. After screening of different hybridoma colonies by ELISA, a high affinity antibody was selected and purified by affinity chromatography. The affinity constant of the antibody was measured by ELISA. Western blot, immunocytochemistry, and flow cytometry experiments were used to characterize the antibody. The anti-leptin antibody had a high affinity (around 1.13 × 10(-9) M) for its antigen. The saturation of the antibody with leptin (20 moles leptin per 1 mole antibody) in Western blot analysis proved that the antibody had specific binding to its antigen. Immunocytochemistry and flow cytometry on JEG-3 (human placental choriocarcinoma cell) cells revealed that the anti-leptin antibody recognized intracellular leptin. In conclusion, we report here the production and characterization of a murine anti-leptin antibody with high affinity for human leptin. PMID:23098305

  3. Antiphospholipid Antibody and Antiphospholipid Syndrome

    Institute of Scientific and Technical Information of China (English)

    吴竞生

    2008-01-01

    @@ Antiphospholipid antibodies (APA) APA is a big category for all kinds of negative charge phospholipid or lecithin - a protein complex autoantibodies or the same antibody, through its recognition of antigen (target protein) different, and phospholipids or lecithin - protein complex combination of various rely on the interference Phospholipid clotting and anti-coagulation factor, and promote endothelial cells, platelets, complement activation and play a role. APA including lupus anticoagulant(LA) and anticardiolipin antibody (ACA), In addition, there are anti-β2 glycoprotein-I (β2-GPI) antibody, anti-prothrombin (a- PT) antibody, anti-lysophosphatidic acid antibody and anti-phosphatidylserine antibody, and so on. APA as the main target of phospholipid-binding protein, including β2-GPI, prothrombin, annexin, protein C (PC) and protein S (PS), plasminogen, and so on.

  4. Antibody therapy for Ebola

    Science.gov (United States)

    Qiu, Xiangguo; Kobinger, Gary P

    2014-01-01

    Ebola viruses can cause severe hemorrhagic fever in humans and nonhuman primates with fatality rates up to 90%, and are identified as biosafety level 4 pathogens and CDC Category A Agents of Bioterrorism. To date, there are no approved therapies and vaccines available to treat these infections. Antibody therapy was estimated to be an effective and powerful treatment strategy against infectious pathogens in the late 19th, early 20th centuries but has fallen short to meet expectations to widely combat infectious diseases. Passive immunization for Ebola virus was successful in 2012, after over 15 years of failed attempts leading to skepticism that the approach would ever be of potential benefit. Currently, monoclonal antibody (mAbs)-based therapies are the most efficient at reversing the progression of a lethal Ebola virus infection in nonhuman primates, which recapitulate the human disease with the highest similarity. Novel combinations of mAbs can even fully cure lethally infected animals after clinical symptoms and circulating virus have been detected, days into the infection. These new developments have reopened the door for using antibody-based therapies for filovirus infections. Furthermore, they are reigniting hope that these strategies will contribute to better control the spread of other infectious agents and provide new tools against infectious diseases. PMID:24503566

  5. Tracking hantavirus nucleocapsid protein using intracellular antibodies

    Directory of Open Access Journals (Sweden)

    Liang Mifang

    2010-11-01

    Full Text Available Abstract Background Hantavirus nucleocapsid (N protein is a multifunctional viral macromolecule involved in multiple stages of the viral replication cycle. The intracellular trafficking of N protein during virus assembly remains unclear. Methods We used N protein-specific intracellular expressed antibodies to track the localization and distribution of Hantaan virus and Seoul virus N protein. The N protein-specific antibody single-chain variable antibody fragments (scFvs, which bind an N-terminal linear epitope (L13F3 and C-terminal conformational domain (H34, were intracellularly expressed in the endoplasmic reticulum (ER by fusion of the SEKDEL retention signal peptide at the carboxyl terminus, and in the cytoplasm (Cyto by deletion of the ER membrane target signal peptide. Stable Vero-E6 cell lines expressing intracellular scFvs were either infected with hantavirus or transfected with an N protein expression plasmid; virus replication and N protein intracellular localization were determined. Result N protein co-localized with scFvs in the ER and cytoplasm with or without viral membrane glycoproteins. Hantavirus replication was inhibited in both the scFvs-ER- and scFvs-Cyto-expressing stable cell lines. Conclusion N protein may be expressed in the ER retention signal peptide of KDEL circulating region (ER/cis-Golgi without the assistance of G protein, and so expression of N protein in both the cytoplasm and within the ER/cis-Golgi plays an important role in virus replication.

  6. Production of antibodies against measles virions by use of the mouse hybridoma technique

    Energy Technology Data Exchange (ETDEWEB)

    Togashi, T.; Oervell, C.; Norrby, E. (Kungliga Karolinska Mediko-Kirurgiska Inst., Stockholm (Sweden)); Vartdal, F. (Rikshospitalet, Oslo (Norway))

    1981-01-01

    Mouse hybridoma cell lines were produced by fusion of P3 x 63 Ag8 mycloma cells with spleen cells from BALB/c mice immunized with purified measles virions. About 60 per cent of single cell colonies in wells were found to produce measles antibodies as determined by a radioimmune assay. Selected measles antibody producing hybridoma cell lines were passaged intraperitoncally in mice and ascites fluids were collected. This material contained 20 - 200 times higher antibody titers than unconcentrated medium from hybridoma cell lines propagated in tissue culture. The ascites fluid antibody products of 23 hybridoma cell lines were characterized by different measles serological tests. Seventeen lines produced high titers of hemagglutination inhibiting (HI) and hemolysis-inhibition (HLI) antibodies. One hybridoma cell line produced Ig with low HI but high HLI activity and the remaining 5 hybridoma cell line products only carried HLI activity. Unexepctedly it was found in radioimmune precipitation assays that all hybridomas studied, including those showing HLI but no HI antibody activity, gave a selective precipitation of the 79 K measles hemagglutinin polypeptide. Radioimmune precipitation assays with sera from immunized animals showed that they contained high titers of antibodies precipitating the 79 K polypeptide but in addition also somewhat lower titers of antibodies precipitating the 60 K nucleoprotein, 40 K fusion and 36 K matrix polypeptides. Homogeneous Ig products carrying measles antibody activity were demonstrated by imprint immunoelectrophoresis of ascites materials.

  7. Production of antibodies against measles virions by use of the mouse hybridoma technique

    International Nuclear Information System (INIS)

    Mouse hybridoma cell lines were produced by fusion of P3 x 63 Ag8 mycloma cells with spleen cells from BALB/c mice immunized with purified measles virions. About 60 per cent of single cell colonies in wells were found to produce measles antibodies as determined by a radioimmune assay. Selected measles antibody producing hybridoma cell lines were passaged intraperitoncally in mice and ascites fluids were collected. This material contained 20 - 200 times higher antibody titers than unconcentrated medium from hybridoma cell lines propagated in tissue culture. The ascites fluid antibody products of 23 hybridoma cell lines were characterized by different measles serological tests. Seventeen lines produced high titers of hemagglutination inhibiting (HI) and hemolysis-inhibition (HLI) antibodies. One hybridoma cell line produced Ig with low HI but high HLI activity and the remaining 5 hybridoma cell line products only carried HLI activity. Unexepctedly it was found in radioimmune precipitation assays that all hybridomas studied, including those showing HLI but no HI antibody activity, gave a selective precipitation of the 79 K measles hemagglutinin polypeptide. Radioimmune precipitation assays with sera from immunized animals showed that they contained high titers of antibodies precipitating the 79 K polypeptide but in addition also somewhat lower titers of antibodies precipitating the 60 K nucleoprotein, 40 K fusion and 36 K matrix polypeptides. Homogeneous Ig products carrying measles antibody activity were demonstrated by imprint immunoelectrophoresis of ascites materials. (Author)

  8. Monoclonal antibody to Streptococcus mutans type e cell wall polysaccharide antigen.

    OpenAIRE

    Kato, H; Ota, F; K. Fukui; Yagawa, K

    1986-01-01

    A monoclonal antibody against the polysaccharide antigen of Streptococcus mutans serotype e was prepared. It was found that beta-methyl-D-glucopyranoside and cellobiose markedly inhibited the precipitin reaction, whereas maltose showed no inhibition. The beta-glucosyl moiety of the type e polysaccharide seems to be the predominant antigenic determinant of the antigen.

  9. Regulation of viral transcription by the matrix protein of vesicular stomatitis virus probed by monoclonal antibodies and temperature-sensitive mutants.

    OpenAIRE

    Pal, R; Grinnell, B.W.; Snyder, R M; Wagner, R R

    1985-01-01

    The ability of the matrix (M) protein of wild-type vesicular stomatitis virus (VSV) to regulate viral transcription was studied with monoclonal antibodies and temperature-sensitive (ts) mutants in complementation group III, the M proteins of which are restricted in transcription inhibition. The marked inhibition of transcription by VSV ribonucleoprotein (RNP) cores complexed with M protein (RNP/M) was reversed by antibody to epitope 1. Antibodies to epitopes 2 and 3 not only failed to reverse...

  10. Production in vitro of antibodies directed against alloantigen-specific recognition sites on T cells and on lymphocytotoxic HLA antibodies.

    Science.gov (United States)

    Singal, D P; Blajchman, M A; Joseph, S; Roberge, B; Smith, E K; Ludwin, D

    1988-01-01

    We have examined the mechanism of immunological unresponsiveness in a recipient (P.S.) with a long-term functioning renal allograft. P.S., whose HLA type is A1, A30; B14, B18; DR1, w8; DRw52; DQw1 and in whose serum we had earlier demonstrated the presence of antiidiotypic antibodies, received a kidney from a cadaver donor of HLA type A1, A10, B8 in March, 1970. Peripheral blood B lymphocytes from the patient were transformed with Epstein-Barr virus (EBV), and by the cluster-picking technique a B cell line was propagated with continuous production of antibodies. Antiidiotypic antibodies with two distinct biological functions were demonstrable; one specifically inhibiting the lymphocytotoxic activity of anti-HLA-B8, B5, and DR3 reference typing sera, and the other specifically inhibiting proliferative responses in MLC of the recipient's lymphocytes and of third party cells sharing B14, DR1, DQw1 with the patient against stimulator cells carrying B8, DR3 antigens. Immunodepletion experiments demonstrated that the inhibitory activity was associated with the IgM fraction. Absorption experiments suggested that different antibodies may be responsible for the inhibition of lymphocytotoxic activity of anti-HLA sera and of the proliferative responses in MLC. Antiidiotypic antibodies have been postulated to be important in maintaining allograft tolerance in vivo, thereby enhancing renal allograft survival. The availability of such antibodies in large quantities, produced in vitro, could provide antisera for the immunochemical characterization of specific idiotypic receptors on immunoglobulins and T lymphocytes. PMID:2970351

  11. Strong antitumor activities of IgG3 antibodies to a human melanoma-associated ganglioside

    International Nuclear Information System (INIS)

    Three mouse monoclonal IgG3 antibodies, 2B2, IF4, and MG-21, recognize a G/sub D3/ ganglioside antigen that is expressed at the cell surface of most human melanomas. All three antibodies mediate antibody-dependent cellular cytotoxicity (ADCC) in vitro when tested with human lymphocytes or effector cells in a 2-hr or 4-hr 51Cr-release test, and one antibody, MG-21, also gives strong complement-dependent cytotoxicity with human serum. Antibody 2B2, which gives ADDC also in the presence of mouse lymphocytes, inhibited the outgrowth of a human melanoma in nude mice, but antibody IF4, which showed no ADCC with mouse lymphocyte effectors, did not

  12. Comparisons of the effect of naturally acquired maternal pertussis antibodies and antenatal vaccination induced maternal tetanus antibodies on infant's antibody secreting lymphocyte responses and circulating plasma antibody levels.

    Science.gov (United States)

    Ahmad, Shaikh Meshbahuddin; Alam, Jahangir; Afsar, Nure Alam; Huda, Nazmul; Kabir, Yearul; Qadri, Firdausi; Raqib, Rubhana; Stephensen, Charles B

    2016-04-01

    The goal of this study was to explore the effects of trans-placental tetanus toxoid (TT) and pertussis (PT) antibodies on an infant's response to vaccination in the context of antenatal immunization with tetanus but not with pertussis. 38 mothers received a single dose of TT vaccine during pregnancy. Infants received tetanus and pertussis vaccines at 6, 10 and 14 wk of age. TT and PT anti-IgG secretion by infant lymphocytes was measured at 15 wk. Plasma antibodies were measured at 6 wk (pre-vaccination), 15 wk and 1 y of age. Prior to vaccination, TT and PT antibody were detected in 94.6% and 15.2% of infants. At 15 wk anti-TT-IgG and anti-PT-IgG in plasma was increased by 7-9 fold over pre-vaccination levels, while at 1 y plasma anti-TT-IgG was decreased by approximately 5-fold from the peak and had returned to near the pre-vaccination level. At 1 y plasma anti-PT-IgG was decreased by 2-fold 1 yfrom the 15 wk level. However, 89.5% and 82.3% of infants at 1 y had protective levels of anti-TT and anti-PT IgG, respectively. Pre-vaccination plasma IgG levels were associated with lower vaccine-specific IgG secretion by infant lymphocytes at 15 wk (p < 0.10). This apparent inhibition was seen for anti-TT-IgG at both 15 wk (p < 0.05) and t 1 y (p < 0.10) of age. In summary, we report an apparent inhibitory effect of passively derived maternal antibody on an infants' own antibody response to the same vaccine. However, since the cut-off values for protective titers are low, infants had protective antibody levels throughout infancy. PMID:27176823

  13. Second antibody clearance of radiolabeled antibody in cancer radioimmunodetection.

    OpenAIRE

    Sharkey, R M; Primus, F J; Goldenberg, D. M.

    1984-01-01

    The imaging of tumors using radiolabeled antibodies previously has required the implementation of computer-assisted subtraction techniques to reduce background radioactivity. A decrease in radioactivity in the blood of hamsters bearing human colonic tumor xenografts has been achieved by administering a second antibody directed against a radiolabeled primary antibody to carcinoembryonic antigen (CEA). This method was found to reduce the level of blood radioactivity by a factor of 4 within 2 hr...

  14. Comparison of indirect immunofluorescence test for measles antibodies with haemagglutination inhibition and plaque neutralization tests Comparação da reação de imunofluorescência indireta para o vírus do sarampo com as reações de inibição da hemaglutinação e neutralização por redução de placas

    Directory of Open Access Journals (Sweden)

    Vanda Akico Ueda Fick de Souza

    1990-10-01

    Full Text Available Indirect Immunofluorescence (IFA, Plaque Reduction Neutralization (PRN and Haemagglutination Inhibition (HI tests for measles antibodies were carried out in 197 sera obtained from umbilical cord and vaccinated children. The IFA was also applied to blood samples collected with filter paper. IFA results demonstrated that the test is relatively simple to perform, with good reproducibility for different antigen lots. Good correlation was obtained between IFA, PRN and HI antibody titers. Better correlation was demonstrated with IFA and PRN than with HI and PRN tests. Sensitivity of IFA in detecting antibody was less effective than PRN, however more effective than HI using rhesus monkey red blood cells. PRN antibody titers over 100 were detected by IFA but not by HI (9.7% with negative results. IFA may be of considerable practical use and able to substitute HI in Seroepidemiological surveys and to evaluate vaccine efficacy. It also can be simplified by employing filter paper collected samples.As reações de imunofluorescência indireta (RIF, neutralização por redução de placas (RNP e inibição da hemaglutinação (RIH para detecção de anticorpos para o vírus do sarampo foram aplicadas a 197 soros provenientes de cordão umbilical e de crianças vacinadas contra o sarampo. Avaliou-se ainda a aplicação da RIF em amostras colhidas em papel de filtro. A RIF apresentou-se como uma prova de execução relativamente simples, de boa reprodutibilidade com diferentes partidas de antígeno. Observou-se boa correlação entre os títulos de anticorpos obtidos por RIF, RNP e RIH. Com a RNP, a RIF apresentou maior correlação que a RIH. A sensibilidade da RIF na detecção de anticorpos contra o sarampo foi menor que RNP, porém superior à da RIH com hemácias de macaco rhesus. Anticorpos com títulos superiores a 100 pela RNP foram sistematicamente detectados pela RIF, mas não por RIH (9,7% de resultados negativos. A RIF pode ser de grande utilidade

  15. Antibody Glossary —

    Science.gov (United States)

    The components of the immune system have diverse roles in the initial development of cancers, progression of early-stage malignancies to invasive tumors, establishment of metastatic lesions, tumor dormancy, and response or resistance to therapy. Characterizing the components of the immune system and their functional status in tissues and in tumors requires the use of highly specific reagents. Researchers employ antibodies in a variety of in vitro and in vivo applications to delineate, enrich, or deplete specific immune subsets in order to understand their role(s) in tumorigenesis. This is a glossary of validated reagents and protocols that are useful for functional phenotyping of the immune system in murine cancer models.

  16. The antibody Hijikata Tatsumi

    Directory of Open Access Journals (Sweden)

    Éden Peretta

    2012-11-01

    Full Text Available Considered one of the most influential modern dance representatives in Japan, Tatsumi Hijikata’s work was a milestone in the Japanese post-war experimental artistic scene. Heretic son of his time, he staged a fertile mix of artistic and cultural influences, overlapping subversive elements of European arts and philosophy with radical references from pre-modern Japanese culture. In this way he built the foundations of its unstable antibody, its political-artistic project of dissolution of a organism, both physical and social.

  17. Microwaving for double indirect immunofluorescence with primary antibodies from the same species and for staining of mouse tissues with mouse monoclonal antibodies

    DEFF Research Database (Denmark)

    Tornehave, D.; Hougaard, D.M.; Larsson, L.I.

    2000-01-01

    Many methods have been devised for double immunocytochemical staining. We now describe that moderate microwaving does not elute antibodies, but prevents their reactions with subsequently applied reagents. Thus, microwaving performed in between the first and second staining cycles permits double...... indirect immunofluorescence staining with antibodies raised in the same species. Moreover, microwaving also inhibits reactions with endogenous immunoglobulins present in extracellular compartments. This substantially reduces background in indirect immunostaining of mouse tissues with mouse monoclonal...

  18. Antibodies to watch in 2015

    OpenAIRE

    Reichert, Janice M

    2014-01-01

    The commercial pipeline of recombinant antibody therapeutics is robust and dynamic. As of early December 2014, a total of 6 such products (vedolizumab, siltuximab, ramucirumab, pembrolizumab, nivolumab, blinatumomab) were granted first marketing approvals in 2014. As discussed in this perspective on antibodies in late-stage development, the outlook for additional approvals, potentially still in 2014 and certainly in 2015, is excellent as marketing applications for 6 antibody therapeutics (sec...

  19. Monoclonal antibodies for treating cancer

    International Nuclear Information System (INIS)

    The purpose of this study is to assess the current status of in-vivo use of monoclonal antibodies for treating cancer. Publications appearing between 1980 and 1988 were identified by computer searches using MEDLINE and CANCERLIT, by reviewing the table of contents of recently published journals, and by searching bibliographies of identified books and articles. More than 700 articles, including peer-reviewed articles and book chapters, were identified and selected for analysis. The literature was reviewed and 235 articles were selected as relevant and representative of the current issues and future applications for in-vivo monoclonal antibodies for cancer therapy and of the toxicity and efficacy which has been associated with clinical trials. Approaches include using antibody alone (interacting with complement or effector cells or binding directly with certain cell receptors) and immunoconjugates (antibody coupled to radioisotopes, drugs, toxins, or other biologicals). Most experience has been with murine antibodies. Trials of antibody alone and radiolabeled antibodies have confirmed the feasibility of this approach and the in-vivo trafficking of antibodies to tumor cells. However, tumor cell heterogeneity, lack of cytotoxicity, and the development of human antimouse antibodies have limited clinical efficacy. Although the immunoconjugates are very promising, heterogeneity and the antimouse immune response have hampered this approach as has the additional challenge of chemically or genetically coupling antibody to cytotoxic agents. As a therapeutic modality, monoclonal antibodies are still promising but their general use will be delayed for several years. New approaches using human antibodies and reducing the human antiglobulin response should facilitate treatment. 235 references

  20. Metrics for antibody therapeutics development

    OpenAIRE

    Reichert, Janice M

    2010-01-01

    A wide variety of full-size monoclonal antibodies (mAbs) and therapeutics derived from alternative antibody formats can be produced through genetic and biological engineering techniques. These molecules are now filling the preclinical and clinical pipelines of every major pharmaceutical company and many biotechnology firms. Metrics for the development of antibody therapeutics, including averages for the number of candidates entering clinical study and development phase lengths for mAbs approv...

  1. Empowered Antibody Therapies - IBC conference.

    Science.gov (United States)

    Herold, Jens

    2010-10-01

    The Empowered Antibody Therapies conference, held in Burlingame, CA, USA, included topics covering new therapeutic developments in the field of multispecific antibodies. This conference report highlights selected presentations on DVD-Igs from Abbott Laboratories, ImmTACs from Immunocore, 'Dock-and-Lock' technology from Immunomedics, the bispecific BiTE antibody blinatumomab from Micromet, and Triomabs from TRION Pharma and Fresenius Biotech. PMID:20878591

  2. A Neutralizing Antibody Assay Based on a Reporter of Antibody-Dependent Cell-Mediated Cytotoxicity.

    Science.gov (United States)

    Wu, Yuling; Li, Jia J; Kim, Hyun Jun; Liu, Xu; Liu, Weiyi; Akhgar, Ahmad; Bowen, Michael A; Spitz, Susan; Jiang, Xu-Rong; Roskos, Lorin K; White, Wendy I

    2015-11-01

    Benralizumab is a humanized anti-IL5 receptor α (IL5Rα) monoclonal antibody (mAb) with enhanced (afucosylation) antibody-dependent cell-mediated cytotoxicity (ADCC) function. An ADCC reporter cell-based neutralizing antibody (NAb) assay was developed and characterized to detect NAb against benralizumab in human serum to support the clinical development of benralizumab. The optimal ratio of target cells to effector cells was 3:1. Neither parental benralizumab (fucosylated) nor benralizumab Fab resulted in ADCC activity, confirming the requirement for ADCC activity in the NAb assay. The serum tolerance of the cells was determined to be 2.5%. The cut point derived from normal and asthma serum samples was comparable. The effective range of benralizumab was determined, and 35 ng/mL [80% maximal effective concentration (EC80)] was chosen as the standard concentration to run in the assessment of NAb. An affinity purified goat anti-benralizumab polyclonal idiotype antibody preparation was shown to have NAb since it inhibited ADCC activity in a dose-dependent fashion. The low endogenous concentrations of IL5 and soluble IL5 receptor (sIL5R) did not demonstrate to interfere with the assay. The estimated assay sensitivities at the cut point were 1.02 and 1.10 μg/mL as determined by the surrogate neutralizing goat polyclonal and mouse monoclonal anti-drug antibody (ADA) controls, respectively. The assay can detect NAb (at 2.5 μg/mL) in the presence of 0.78 μg/mL benralizumab. The assay was not susceptible to non-specific matrix effects. This study provides an approach and feasibility of developing an ADCC cell-based NAb assay to support biopharmaceuticals with an ADCC function. PMID:26205082

  3. Monoclonal antibodies to the human insulin receptor that activate glucose transport but not insulin receptor kinase activity.

    OpenAIRE

    Forsayeth, J R; Caro, J F; Sinha, M K; Maddux, B A; Goldfine, I D

    1987-01-01

    Three mouse monoclonal antibodies were produced that reacted with the alpha subunit of the human insulin receptor. All three both immunoprecipitated 125I-labeled insulin receptors from IM-9 lymphocytes and competitively inhibited 125I-labeled insulin binding to its receptor. Unlike insulin, the antibodies failed to stimulate receptor autophosphorylation in both intact IM-9 lymphocytes and purified human placental insulin receptors. Moreover, unlike insulin, the antibodies failed to stimulate ...

  4. Inhibitory and neutral antibodies to Plasmodium falciparum MSP119 form ring structures with their antigen.

    Science.gov (United States)

    Dekker, Carien; Uthaipibull, Chairat; Calder, Lesley J; Lock, Matthew; Grainger, Munira; Morgan, William D; Dodson, Guy G; Holder, Anthony A

    2004-09-01

    Blood-stage malaria vaccine candidates include surface proteins of the merozoite. Antibodies to these proteins may either block essential steps during invasion or render the merozoite susceptible to phagocytosis or complement-mediated degradation. Structural information on merozoite surface proteins complexed to antibodies provides crucial information for knowledge-based vaccine design. The major merozoite surface protein MSP1 is an abundant surface molecule in Plasmodium falciparum. Only a subset of antibodies against MSP119 inhibits invasion (inhibitory antibodies), whereas other antibodies binding to MSP119 have no effect on invasion (neutral antibodies). Here we report on the complex of MSP119 with both inhibitory monoclonal antibody 12.10 and neutral monoclonal antibody 2F10. The complexes were established using both whole IgG's and Fab fragments, and analysed by dynamic light scattering, electron microscopy and analytical ultra centrifugation. Specific ring structures were formed in the ternary complex with the two antibodies, providing direct evidence of non-overlapping epitopes on MSP119. Mutational studies also indicated that the epitopes of the inhibitory and neutral antibodies are spatially remote. PMID:15279960

  5. Binding-site analysis of opioid receptors using monoclonal anti-idiotypic antibodies

    International Nuclear Information System (INIS)

    Structural relatedness between the variable region of anti-ligand antibodies and opioid binding sites allowed the generation of anti-idiotypic antibodies which recognized opioid receptors. The IgG3k antibodies which bound to opioid receptors were obtained when an anti-morphine antiserum was the idiotype. Both antibodies bound to opioid receptors, but only one of these blocked the binding of [3H]naloxone. The antibody which did not inhibit the binding of [3H]naloxone was itself displaced from the receptor by opioid ligands. The unique binding properties displayed by this antibody indicated that anti-idiotypic antibodies are not always a perfect image of the original ligand, and therefore may be more useful than typical ligands as probes for the receptor. An auto-anti-idiotypic technique was successfully used to obtain anti-opioid receptor antibodies. Another IgG3k antibody that blocked the binding of [3H]naloxone to rat brain opioid receptors was obtained when a mouse was immunized with naloxone conjugated to bovine serum albumin. These data confirmed that an idiotype-anti-idiotype network which can generate an anti-receptor antibody normally functions when an opioid ligand is introduced into an animal in an immunogenic form

  6. Binding-site analysis of opioid receptors using monoclonal anti-idiotypic antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, W.G.

    1988-01-01

    Structural relatedness between the variable region of anti-ligand antibodies and opioid binding sites allowed the generation of anti-idiotypic antibodies which recognized opioid receptors. The IgG{sub 3}k antibodies which bound to opioid receptors were obtained when an anti-morphine antiserum was the idiotype. Both antibodies bound to opioid receptors, but only one of these blocked the binding of ({sup 3}H)naloxone. The antibody which did not inhibit the binding of ({sup 3}H)naloxone was itself displaced from the receptor by opioid ligands. The unique binding properties displayed by this antibody indicated that anti-idiotypic antibodies are not always a perfect image of the original ligand, and therefore may be more useful than typical ligands as probes for the receptor. An auto-anti-idiotypic technique was successfully used to obtain anti-opioid receptor antibodies. Another IgG{sub 3}k antibody that blocked the binding of ({sup 3}H)naloxone to rat brain opioid receptors was obtained when a mouse was immunized with naloxone conjugated to bovine serum albumin. These data confirmed that an idiotype-anti-idiotype network which can generate an anti-receptor antibody normally functions when an opioid ligand is introduced into an animal in an immunogenic form.

  7. Antibody informatics for drug discovery

    DEFF Research Database (Denmark)

    Shirai, Hiroki; Prades, Catherine; Vita, Randi;

    2014-01-01

    infrastructure for these large data sets has become necessary. In this article, we first identify and discuss the typical obstacles faced during the antibody drug discovery process. We then summarize the current status of three sub-fields of antibody informatics as follows: (i) recent progress in technologies...... (iii) antibody numbering and IMGT. Here, we review “antibody informatics,” which may integrate the above three fields so that bridging the gaps between industrial needs and academic solutions can be accelerated. This article is part of a Special Issue entitled: Recent advances in molecular engineering...

  8. Tumor imaging with monoclonal antibodies

    International Nuclear Information System (INIS)

    Many monoclonal antibodies directed against tumor-associated antigens have been identified, but so far none of these are tumor specific. Polyclonal and monoclonal antibodies have been used for imaging of a wide variety of tumors with success. Radiolabeling of antibody is usually done with iodine isotopes of which 123I is the best candidate for radioimmunodetection purposes. The labeling of antibodies through chelates makes it possible to use metal radioisotopes like 111In, which is the best radioisotope for imaging with monoclonal antibodies due to its favorable half-life of 2.5 days. Usually imaging cannot be performed within 24 h after injection, but clearance of antibody can be increased by using F(ab)2 of Fab. Another approach is to clear non-bound antibody by a second antibody, directed against the first. The detection limit of immunoimaging is about 2 cm, but will be improved by tomography or SPECT. There is still a high false positive and false negative rate, which makes it impossible to use radioimmunodetection as the only technique for diagnosis of tumors. In combination with other detection techniques, tumor imaging with monoclonal antibodies can improve diagnosis. 44 refs.; 3 tabs

  9. Novel anti-HER2 monoclonal antibodies: synergy and antagonism with tumor necrosis factor-α

    International Nuclear Information System (INIS)

    One-third of breast cancers display amplifications of the ERBB2 gene encoding the HER2 kinase receptor. Trastuzumab, a humanized antibody directed against an epitope on subdomain IV of the extracellular domain of HER2 is used for therapy of HER2-overexpressing mammary tumors. However, many tumors are either natively resistant or acquire resistance against Trastuzumab. Antibodies directed to different epitopes on the extracellular domain of HER2 are promising candidates for replacement or combinatorial therapy. For example, Pertuzumab that binds to subdomain II of HER2 extracellular domain and inhibits receptor dimerization is under clinical trial. Alternative antibodies directed to novel HER2 epitopes may serve as additional tools for breast cancer therapy. Our aim was to generate novel anti-HER2 monoclonal antibodies inhibiting the growth of breast cancer cells, either alone or in combination with tumor necrosis factor-α (TNF-α). Mice were immunized against SK-BR-3 cells and recombinant HER2 extracellular domain protein to produce monoclonal antibodies. Anti-HER2 antibodies were characterized with breast cancer cell lines using immunofluorescence, flow cytometry, immunoprecipitation, western blot techniques. Antibody epitopes were localized using plasmids encoding recombinant HER2 protein variants. Antibodies, either alone or in combination with TNF-α, were tested for their effects on breast cancer cell proliferation. We produced five new anti-HER2 monoclonal antibodies, all directed against conformational epitope or epitopes restricted to the native form of the extracellular domain. When tested alone, some antibodies inhibited modestly but significantly the growth of SK-BR-3, BT-474 and MDA-MB-361 cells displaying ERBB2 amplification. They had no detectable effect on MCF-7 and T47D cells lacking ERBB2 amplification. When tested in combination with TNF-α, antibodies acted synergistically on SK-BR-3 cells, but antagonistically on BT-474 cells. A representative

  10. Novel anti-HER2 monoclonal antibodies: synergy and antagonism with tumor necrosis factor-α

    Directory of Open Access Journals (Sweden)

    Ceran Ceyhan

    2012-10-01

    Full Text Available Abstract Background One-third of breast cancers display amplifications of the ERBB2 gene encoding the HER2 kinase receptor. Trastuzumab, a humanized antibody directed against an epitope on subdomain IV of the extracellular domain of HER2 is used for therapy of HER2-overexpressing mammary tumors. However, many tumors are either natively resistant or acquire resistance against Trastuzumab. Antibodies directed to different epitopes on the extracellular domain of HER2 are promising candidates for replacement or combinatorial therapy. For example, Pertuzumab that binds to subdomain II of HER2 extracellular domain and inhibits receptor dimerization is under clinical trial. Alternative antibodies directed to novel HER2 epitopes may serve as additional tools for breast cancer therapy. Our aim was to generate novel anti-HER2 monoclonal antibodies inhibiting the growth of breast cancer cells, either alone or in combination with tumor necrosis factor-α (TNF-α. Methods Mice were immunized against SK-BR-3 cells and recombinant HER2 extracellular domain protein to produce monoclonal antibodies. Anti-HER2 antibodies were characterized with breast cancer cell lines using immunofluorescence, flow cytometry, immunoprecipitation, western blot techniques. Antibody epitopes were localized using plasmids encoding recombinant HER2 protein variants. Antibodies, either alone or in combination with TNF-α, were tested for their effects on breast cancer cell proliferation. Results We produced five new anti-HER2 monoclonal antibodies, all directed against conformational epitope or epitopes restricted to the native form of the extracellular domain. When tested alone, some antibodies inhibited modestly but significantly the growth of SK-BR-3, BT-474 and MDA-MB-361 cells displaying ERBB2 amplification. They had no detectable effect on MCF-7 and T47D cells lacking ERBB2 amplification. When tested in combination with TNF-α, antibodies acted synergistically on SK-BR-3 cells

  11. Different binding of stimulatory-type and blocking-type TSH receptor antibody with guinea-pig testis membrane.

    Science.gov (United States)

    Inui, T; Ochi, Y; Hachiya, T; Chen, W; Nakajima, Y; Kajita, Y; Ogura, H

    1991-11-01

    A receptor assay using [125I]bTSH-binding to guinea-pig testis membrane was developed. Unlabelled hCG and FSH inhibited [125I]bTSH binding. In patients with Graves' disease and in untreated hyperthyroid patients, almost all long-acting thyroid stimulators and thyroid-stimulating antibodies, respectively did not inhibit [125I]bTSH binding, which on the other hand was inhibited by thyroid stimulation blocking antibodies in patients with primary hypothyroidism. When the inhibitory effect on the binding of [125I]hCG and 125I-synthetic alpha-subunit peptide (alpha 26-46) of hCG to testis membrane was examined, bTSH resulted in a significant inhibition. However, all three kinds of TSH receptor antibodies had no inhibitory effect. This study demonstrated 1. interaction of alpha-subunit of TSH and hCG with the testicular receptor; 2. binding of thyroid stimulation-blocking antibody and lack of binding of thyroid-stimulating antibody to the testicular TSH receptor in spite of binding of these TSH receptor antibodies to the thyroidal TSH receptor, and 3. lack of binding of thyroid-stimulating antibody and thyroid stimulation-blocking antibody to the testicular gonadotropin receptor. PMID:1684686

  12. Creating Ordered Antibody Arrays with Antibody-Polymer Conjugates

    Science.gov (United States)

    Dong, Xuehui; Obermeyer, Allie; Olsen, Bradley

    Antibodies are a category of functional proteins that play crucial roles in the immune system and have been widely applied in the area of cancer therapeutics, targeting delivery, signal detection, and sensors. Due to the extremely large size and lack of specific functional groups on the surface, it is challenging to functionalize antibodies and manipulate the ordered packing of antibodies in an array with high density and proper orientation, which is critical to achieve outstanding performance in materials. In this work, we demonstrate an efficient and facile approach for preparing antibody-polymer conjugates with two-step sequential ``click'' reaction to form antibody-polymer block copolymers. Highly ordered nanostructures are fabricated based on the principles of block copolymer self-assembly. The nanostructures are studied with both small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Lamellae with alternating antibody domain and polymer domain are observed with an overall domain size of ~50 nm. The nanostructure not only increases the packing density and promotes proper orientation of the antibody, but also provides possible channel to facilitate substrate transportation and improves the stability of the antibody.

  13. Detection of IgE insulin antibody with radioallergosorbent test

    International Nuclear Information System (INIS)

    An in vitro method for detecting IgE insulin antibody using the principle of the radioallergosorbent test (RAST) is described. In six patients with insulin allergy, the RAST values were higher than in normal persons or insulin-treated diabetics without insulin allergy. No differences were observed between normal persons and insulin-treated diabetics without insulin allergy. Moreover, it was observed that in one patient treated with highly purified insulin, there was a gradual decrease of RAST value parallel to the radioinsulin binding activity and clinical allergic symptoms. The RAST value of insulin is slightly inhibited by non-IgE antibodies and is, therefore, a semiquantitative value. However, the RAST is simple to perform and reproducible; it is therefore very useful in the detection of IgE insulin antibodies. (orig.)

  14. A monoclonal antibody to the platelet membrane IIb-IIIa glycoprotein complex

    International Nuclear Information System (INIS)

    A hybridoma that secretes monoclonal mouse anti-platelet antibody has been produced by fusing spleen cells from immunized Balb/c mice with NS-1 myeloma cells using polyethylene glycol. Bulk production of the antibody was accomplished in vivo by injecting the cloned hybridoma cells intraperitoneally into pristane-primed mice. The antibody was purified from the ascitic fluid and characterised as belonging to the IgG1 sub-class by straphylococcal protein A-sepharose affinity chromatography. Purity was ascertained by SDS PAGE and isoelectric focusing. The antibody inhibited clot retraction of normal human blood and platelet aggregation induced by ADP, thrombin or epinephrine. Equilibrium binding studies revealed that the number of antibody molecules bound per platelet varied between 21 000 and 67 000 with an average of 42 000. Immunoprecipitation experiments with radioactively labelled platelets showed that the antibody bound the IIb-IIa glycoprotein complex. Platelets of patients with Glanzmann's thrombasthenia (a hereditary defect in which these glycoproteins are deficient) failed to bind the antibody. Immunofluorescent techniques showed that the antigen was present on megakaryocytes and platelets but not on the other cells from defibrinated peripheral blood. The antibody was also able to inhibit specifically the binding of radiolabelled human fibrinogen to ADP-stimulated platelets

  15. Monoclonal antibodies that bind the renal Na+/glucose symport system. 1. Identification

    International Nuclear Information System (INIS)

    Phlorizin is a specific, high-affinity ligand that binds the active site of the Na+/glucose symporter by a Na+-dependent mechanism but is not itself transported across the membrane. The authors have isolated a panel of monoclonal antibodies that influence high-affinity, Na+-dependent phlorizin binding to pig renal brush border membranes. Antibodies were derived after immunization of mice either with highly purified renal brush border membranes or with apical membranes purified from LLC-PK1, a cell line of pig renal proximal tubule origin. Antibody 11A3D6, an IgG/sub 2b/, reproducibly stimulated Na+-dependent phlorizin binding whereas antibody 18H10B12, an IgM, strongly inhibited specific binding. These effects were maximal after 30-min incubation and exhibited saturation at increased antibody concentrations. Antibodies did not affect Na+-dependent sugar uptake in vesicles but significantly prevented transport inhibition by bound phlorizin. Antibodies recognized a 75-kDa antigen identified by Western blot analysis of brush border membranes, and a 75-kDa membrane protein could be immunoprecipitated by 18H10B12. These properties, provide compelling evidence that the 75-kDa antigen recognized by these antibodies is a component of the renal Na+/glucose symporter

  16. Development and Optimization of High-Throughput Methods To Measure Plasmodium falciparum-Specific Growth Inhibitory Antibodies

    OpenAIRE

    Persson, Kristina E. M.; Lee, Chee T.; Marsh, Kevin; Beeson, James G.

    2006-01-01

    Antibodies that inhibit replication of Plasmodium falciparum in erythrocytes are thought to be important both in acquired immunity to malaria and as mediators of immunity generated by candidate blood-stage vaccines. However, several constraints have limited the study of these functional antibodies in population studies and vaccine trials. We report the development and optimization of high-throughput growth inhibition assays with improved sensitivity that use minimal volumes of test serum. The...

  17. A Cell-Based Internalization and Degradation Assay with an Activatable Fluorescence-Quencher Probe as a Tool for Functional Antibody Screening.

    Science.gov (United States)

    Li, Yan; Liu, Peter Corbett; Shen, Yang; Snavely, Marshall D; Hiraga, Kaori

    2015-08-01

    For the development of therapeutically potent anti-cancer antibody drugs, it is often important to identify antibodies that internalize into cells efficiently, rather than just binding to antigens on the cell surface. Such antibodies can mediate receptor endocytosis, resulting in receptor downregulation on the cell surface and potentially inhibiting receptor function and tumor growth. Also, efficient antibody internalization is a prerequisite for the delivery of cytotoxic drugs into target cells and is critical for the development of antibody-drug conjugates. Here we describe a novel activatable fluorescence-quencher pair to quantify the extent of antibody internalization and degradation in the target cells. In this assay, candidate antibodies were labeled with a fluorescent dye and a quencher. Fluorescence is inhibited outside and on the surface of cells, but activated upon endocytosis and degradation of the antibody. This assay enabled the development of a process for rapid characterization of candidate antibodies potentially in a high-throughput format. By employing an activatable secondary antibody, primary antibodies in purified form or in culture supernatants can be screened for internalization and degradation. Because purification of candidate antibodies is not required, this method represents a direct functional screen to identify antibodies that internalize efficiently early in the discovery process. PMID:26024945

  18. Induction of Type I Interferon Secretion through Recombinant Newcastle Disease Virus Expressing Measles Virus Hemagglutinin Stimulates Antibody Secretion in the Presence of Maternal Antibodies▿

    OpenAIRE

    Kim, Dhohyung; Martinez-Sobrido, Luis; Choi, Changsun; Petroff, Natasha; García-Sastre, Adolfo; Niewiesk, Stefan; Carsillo, Thomas

    2010-01-01

    Measles virus (MV) vaccine effectively protects seronegative individuals against infection. However, inhibition of vaccine-induced seroconversion by maternal antibodies after vaccination remains a problem, as it leaves infants susceptible to MV infection. In cotton rats, passive transfer of MV-specific IgG mimics maternal antibodies and inhibits vaccine-induced seroconversion. Here, we report that immunization in the presence of passively transferred IgG inhibits the secretion of neutralizing...

  19. Antiphospholipid antibodies and infertility.

    Science.gov (United States)

    Chighizola, C B; de Jesus, G R

    2014-10-01

    Since the late 1980s some publications have proposed that antiphospholipid antibodies (aPL) may have some relationship with infertility, considering reported deleterious effects that aPL exert on trophoblast proliferation and growth. Although not included in current classification criteria for antiphospholipid syndrome, many physicians investigate for aPL in patients with a history of infertility, including antibodies not listed in classification criteria, and most of those patients will receive anticoagulant therapy if any of those antibodies have a result considered positive. A review of literature was conducted searching for studies that investigated the association of aPL and infertility and if aPL positivity alters in vitro fertilization (IVF) outcome. The definition of infertility, routine work-up to exclude other causes of infertility, definition of IVF failure as inclusion criteria and control populations were heterogeneous among studies. Most of them enrolled women over 40 years of age, and exclusion of other confounding factors was also inconsistent. Of 29 studies that assessed aPL positivity rates in infertile women, the majority had small sample sizes, implying a lack of power, and 13 (44.8%) reported higher frequency of aPL in infertile patients compared to controls, but most of them investigated a panel of non-criteria aPL tests, whose clinical significance is highly controversial. Only two studies investigated all three criteria tests, and medium-high titer of anticardiolipin cut-off conforming to international guidelines was used in one study. Considering IVF outcome, there was also disparity in this definition: few studies assessed the live birth rate, others the implantation rate. Of 14 publications that addressed the relationship between aPL and IVF outcome, only two described a detrimental effect of these autoantibodies. In conclusion, available data do not support an association between aPL and infertility, and aPL positivity does not seem to

  20. Targeting of Antibodies using Aptamers

    OpenAIRE

    Missailidis, Sotiris

    2003-01-01

    The chapter presents a methodology for the rapid selection of aptamers against antibody targets. It is a detailed account of the various methodological steps that describe the selection of aptamers, including PCR steps, buffers to be used, target immobilisation, partitioning and amplification of aptamers, clonning and sequencing, to results in high affinity and specificity ligands for the chosen target antibody.

  1. Refolding Technologies for Antibody Fragments

    OpenAIRE

    Tsutomu Arakawa; Daisuke Ejima

    2014-01-01

    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 suppresso...

  2. Effects of tau domain-specific antibodies and intravenous immunoglobulin on tau aggregation and aggregate degradation.

    Science.gov (United States)

    Esteves-Villanueva, Jose O; Trzeciakiewicz, Hanna; Loeffler, David A; Martić, Sanela

    2015-01-20

    Tau pathology, including neurofibrillary tangles, develops in Alzheimer's disease (AD). The aggregation and hyperphosphorylation of tau are potential therapeutic targets for AD. Administration of anti-tau antibodies reduces tau pathology in transgenic "tauopathy" mice; however, the optimal tau epitopes and conformations to target are unclear. Also unknown is whether intravenous immunoglobulin (IVIG) products, currently being evaluated in AD trials, exert effects on pathological tau. This study examined the effects of anti-tau antibodies targeting different tau epitopes and the IVIG Gammagard on tau aggregation and preformed tau aggregates. Tau aggregation was assessed by transmission electron microscopy and fluorescence spectroscopy, and the binding affinity of the anti-tau antibodies for tau was evaluated by enzyme-linked immunosorbent assays. Antibodies used were anti-tau 1-150 ("D-8"), anti-tau 259-266 ("Paired-262"), anti-tau 341-360 ("A-10"), and anti-tau 404-441 ("Tau-46"), which bind to tau's N-terminus, microtubule binding domain (MBD) repeat sequences R1 and R4, and the C-terminus, respectively. The antibodies Paired-262 and A-10, but not D-8 and Tau-46, reduced tau fibrillization and degraded preformed tau aggregates, whereas the IVIG reduced tau aggregation but did not alter preformed aggregates. The binding affinities of the antibodies for the epitope for which they were specific did not appear to be related to their effects on tau aggregation. These results confirm that antibody binding to tau's MBD repeat sequences may inhibit tau aggregation and indicate that such antibodies may also degrade preformed tau aggregates. In the presence of anti-tau antibodies, the resulting tau morphologies were antigen-dependent. The results also suggested the possibility of different pathways regulating antibody-mediated inhibition of tau aggregation and antibody-mediated degradation of preformed tau aggregates. PMID:25545358

  3. ANTISPERM ANTIBODIES IN VASOVASOSTOMY

    Directory of Open Access Journals (Sweden)

    Gholamreza Pourmand

    1993-06-01

    Full Text Available Two hundred and forty patients, who had undergone vasectomy from 1977 to 1985 and subsequent vasovasostomy ,were studied for the presence of sperm-specific antibodies by using the Kibrick's gelatin agglutination test. The number of successful pregnancies and the presence of agglutination were also considered in this survey. Sixty-nine pregnancies occurred in total and agglutination was present in 49% out of 51% positive specimens by the Kibrick Test."nThe average sperm motility was slightly higher in the negative Kibrick group than in the positive Kibrick group. The obtained data indicated that there seems to be a relationship between the increased titers and percentage of agglutination in semen samples.

  4. Metrics for antibody therapeutics development.

    Science.gov (United States)

    Reichert, Janice M

    2010-01-01

    A wide variety of full-size monoclonal antibodies (mAbs) and therapeutics derived from alternative antibody formats can be produced through genetic and biological engineering techniques. These molecules are now filling the preclinical and clinical pipelines of every major pharmaceutical company and many biotechnology firms. Metrics for the development of antibody therapeutics, including averages for the number of candidates entering clinical study and development phase lengths for mAbs approved in the United States, were derived from analysis of a dataset of over 600 therapeutic mAbs that entered clinical study sponsored, at least in part, by commercial firms. The results presented provide an overview of the field and context for the evaluation of on-going and prospective mAb development programs. The expansion of therapeutic antibody use through supplemental marketing approvals and the increase in the study of therapeutics derived from alternative antibody formats are discussed. PMID:20930555

  5. Preparation of Anti-Idiotypic Antibody against Avian Influenza Virus Subtype H9

    Institute of Scientific and Technical Information of China (English)

    BaoquanLi; JunPeng; ZhongxiangNiu; XunheYin; FaxiaoLiu

    2005-01-01

    To generate monoclonal anti-idiotypic antibodies (mAb2) against avian influenza virus subtype H9 (H9 AIV), BALB/c mice were immunized with purified chicken anti-H9-AIV IgG and the splenocytes of immunized mice were fused with myeloma cells NS-1. Hybridoma cells were screened by indirect enzyme-linked immunosorbent assays with both chicken and rabbit anti-H9-AIV IgG as coating antigens. One hybridoma cell clone secreting monoclonal antibody against idiotypes shared by both chicken and rabbit anti-H9-AIV IgG was established. Experiments demonstrated the mAb2 was able to inhibit the binding of hemagglutinin to anti-H9-AIV IgG and to induce chickens to generate hemagglutination inhibition antibodies, indicating this anti-species-sharing-idiotypic antibody bore the internal image of hemagglutinin on avian influenza virus. Cellular & Molecular Immunology. 2005;2(2):155-157.

  6. Preparation of Anti-Idiotypic Antibody against Avian Influenza Virus Subtype H9

    Institute of Scientific and Technical Information of China (English)

    Baoquan Li; Jun Peng; Zhongxiang Niu; Xunhe Yin; Faxiao Liu

    2005-01-01

    To generate monoclonal anti-idiotypic antibodies (mAb2) against avian influenza virus subtype H9 (H9 AIV),BALB/c mice were immunized with purified chicken anti-H9-AIV IgG and the splenocytes of immunized mice were fused with myeloma cells NS-1. Hybridoma cells were screened by indirect enzyme-linked immunosorbent assays with both chicken and rabbit anti-H9-AIV IgG as coating antigens. One hybridoma cell clone secreting monoclonal antibody against idiotypes shared by both chicken and rabbit anti-H9-AIV IgG was established. Experiments demonstrated the mAb2 was able to inhibit the binding of hemagglutinin to anti-H9-AIV IgG and to induce chickens to generate hemagglutination inhibition antibodies, indicating this anti-species-sharing-idiotypic antibody bore the internal image of hemagglutinin on avian influenza virus. Cellular & Molecular Immunology. 2005;2(2):155-157.

  7. Epstein-Barr virus antibody test

    Science.gov (United States)

    EBV antibody test; EBV serology ... a lab, where a lab specialist looks for antibodies to the Epstein-Barr virus. In the first stages of an illness, little antibody may be detected. For this reason, the test ...

  8. Measurement of antibodies to tubulin by radioimmunoassay

    International Nuclear Information System (INIS)

    A solid-phase double antibody radioimmunoassay capable of measuring antibody to tubulin, the principal component of microtubules, is described. This assay is simple, combining sensitivity with specificity and also allowing determination of antibody subclasses. (Auth.)

  9. Antibodies - Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    NCI announces the release of monoclonal antipeptide antibodies from rabbit for distribution on the antibody portal. There are 60 recently added monoclonal antibodies, with 56 generated from mouse and 4 generated from rabbit.

  10. Maternal Antibody Protected Chicks from Growth Retardation and Immunosuppression Induced by Early Reticuloendotheliosis Virus Infection

    Institute of Scientific and Technical Information of China (English)

    SUN Shu-hong; GUI Zhi-zhong; QU Li-xin

    2007-01-01

    To determine if the maternal antibody from breeders vaccinated with cell culture-adapted reticuloendotheliosis virus (REV) could protect chicks from early REV infection, one-day-old chicks with or without anti-REV maternal antibodies were inoculated with REV, and then their growth rates and antibody tilers to Newcastle disease virus (NDV) and avian influenza virus (AIV), after vaccination with inactivated vaccines, were compared. This study indicated that REV infection could cause growth retardation and severely inhibit immune reactions to inactivated vaccines against NDV and Avian influenza virus (AIV, H9 and H5) in one-day-old broilers without maternal antibodies specific to REV. Maternal antibody from breeders vaccinated with an attenuated REV vaccine effectively protected REV-challenged birds from growth retardation and immunosuppression on antibody reactions to NDV and AIV vaccines. Four weeks after vaccination, the HI liters to NDV, AIV-H9, and AIV-H5 in maternal antibody positive and negative groups were 3.36±2.04 versus 1.58±1.69 (P<0.01), 6.27±3.87 versus 0.71±1.60(P<0.01), and 6.72 versus 0.54±1.44(p<0.01). Maternal antibodies from breeders vaccinated with REV vaccine could successfully protect chicks from REV infection and effectively prevent REV-induced growth retardation and immunosuppression in antibody responses to NDV and AIV.

  11. Multiple mechanisms in serum factor-induced resistance of Haemophilus influenzae type b to antibody.

    OpenAIRE

    Kuratana, M; Hansen, E J; Anderson, P

    1990-01-01

    Incubation of Haemophilus influenzae type b at less than or equal to 10(7) CFU/ml with serum ultrafiltrate induces a phenotypic conversion in which complement-mediated bactericidal activity by somatic antibodies decreases while killing by capsular antibody is unchanged. Conversion had been shown to occur in a capsule-deficient (b-) mutant of strain Eag (thus appearing independent of capsulation), to include an increase in lipopolysaccharide content, and to be inhibited by chloramphenicol or p...

  12. PREVALENCE OF ANTIBODIES AGAINST INFLUENZA VIRUS IN NON-VACCINATED EQUINES FROM THE BRAZILIAN PANTANAL

    OpenAIRE

    2014-01-01

    The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% ...

  13. Screening for epitope specificity directly on culture supernatants in the early phase of monoclonal antibody production by an ELISA with biotin-labeled antigen

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Jensen, Charlotte H; Gregersen, Annemette; Brandt, Jette; Kliem, Anette; Skjødt, Karsten; Koch, Claus; Teisner, Børge

    2004-01-01

    This report describes an assay for comparison of epitope specificity in groups of monoclonal antibodies against a given antigen. The only prerequisite is the biotin-labeled antigen. One of the monoclonal antibodies is captured onto a plastic surface via a rabbit anti-mouse Ig, and the other...... preincubated with biotinylated antigen. When the two antibodies react with the same epitope subsequent binding of the biotin-labeled antigen is abolished (inhibition). In the cases where no inhibition was observed, the two antibodies were considered to react with distinct, independent epitopes. The obvious...

  14. Specific inhibition of Escherichia coli ferrienterochelin uptake by a normal human serum immunoglobulin.

    OpenAIRE

    Moore, D G; Earhart, C F

    1981-01-01

    Normal human serum contains an enterochelin-specific antibody which presumably acts with transferrin to hinder iron assimilation by enterochelin-producing pathogens. This antibody can be isolated from serum by sodium sulfate fractionation or affinity chromatography by employing an enterochelin-derived ligand (2,3-dihydroxy-N-benzoyl-L-serine) attached to aminohexyl Sepharose 4B. In assays of iron uptake by whole cells, the antibody inhibited enterochelin-directed uptake but not that mediated ...

  15. Role of Blocking TSH Receptor Antibodies on the Development of Hypothyroidism and Thyroid Atrophy in Primary Myxedema

    OpenAIRE

    Cho, Bo Youn; Shong, Young Kee; Lee, Hong Kyu; Koh, Chang-Soon; Min, Hun Ki; Sohn, In

    1989-01-01

    We studied blocking type TSH receptor antibodies in 28 patients with primary myxedema and 21 patients with goitrous Hashimoto’s thyroiditis by measuring the ability of their IgG to inhibit TSH binding to its receptor, and to inhibit TSH-stimulated cAMP increases and 3H-thymidine incorporation in a rat thyroid cell line, FRTL-5. The incidences of TSH binding inhibitor immunoglobulin (TBII), thyroid stimulation blocking antibody (TSBAb) and thyroid growth blocking antibody (TGBAb) in patients w...

  16. 题目:抗CD69单克隆抗体对哮喘小鼠的气道炎症抑制作用研究%Anti-CD69 monoclonal antibody treatment inhibits airway inflammation in a mouse model of asthma

    Institute of Scientific and Technical Information of China (English)

    Hui-ying WANG; Yu DAI; Jiao-li WANG; Xu-yan YANG; Xin-guo JIANG

    2015-01-01

    目的:气道慢性炎症和高反应性是哮喘最主要的病理生理表现,CD69是一种与免疫细胞活化、增殖及凋亡密切相关的共刺激分子,本研究旨在观察抗CD69单克隆抗体在哮喘小鼠模型中抑制气道炎症和高反应性的作用及机制探讨。创新点:(1)与大多数关于哮喘的药物研究多为造模前提前用药以阻断炎症的进展相比,本研究将抗CD69单抗作用于气道已经形成的炎症,与临床上哮喘的治疗更接近;(2)抗CD69单抗的独特作用在于它特异性地作用于气道活化的炎症细胞,与已有的哮喘药物以糖皮质激素相比,可能的全身反应少。方法:鸡卵白蛋白致敏激发制备哮喘模型(图1),Buxco系统测试哮喘小鼠的气道高反应性(图6)。结论:抗CD69单克隆抗体可抑制哮喘小鼠已经形成的气道炎症,其作用效果与地塞米松预处理相当。本研究为临床哮喘的急性发作治疗和管理提供了新的可能靶点。%Objective: Airway inflammation and airway hyper-responsiveness (AHR) are principle pathological mani-festations of asthma. Cluster of differentiation 69 (CD69) is a well-known co-stimulatory factor associated with the activation, proliferation as well as apoptosis of immune cels. This study aims to examine the effect of anti-CD69 monoclonal antibody (mAb) on the pathophysiology of a mouse model of asthma. Methods: A murine model of oval-bumin (OVA)-induced alergic airway inflammation was used in this study. Briefly, mice were injected with 20μg chicken OVA intraperitonealy on Days 0 and 14, folowed by aerosol provocation with 1% (0.01 g/ml) OVA on Days 24, 25, and 26. Anti-CD69 mAb or isotype IgG was injected intraperitoneally after OVA chalenge; dexamethasone (DXM) was administrated either before or after OVA chalenge. AHR, mucus production, and eosinophil infiltration in the peribronchial area were examined. The levels of granulocyte

  17. Immunolocation of antisperm monoclonal antibody 6B10 and corresponding antigen

    Institute of Scientific and Technical Information of China (English)

    高绍荣; 胡国俊; 段崇文; 刘辉; 韩之明; 宋祥芬; 陈大元

    1999-01-01

    An antisperm monoclonal antibody 6B10 was produced by hybridoma technique of the isotype IgG. The monoclonal antibody was purified by means of ammonium sulfate precipitation and protein A-Sepharose Cl-4B affinity chromatography. SDS polyacrylamide gel electrophoresis was used to evaluate the purity of the antibody. Evaluation of the sperm acrosomal status was determined by chlortetracycline (CTC) staining. It was found that monoclonal antibody 6B10 can inhibit the sperm acrosome reaction induced by progesterone. The corresponding antigen recognized by monoclonal antibody 6B10 was located on the plasma membrane of the sperm acrosome by indirect immunofluorescent microscopy and immunoelectronmicroscopy. Sperm protein was extracted by 1% Triton X-100. The molecular weight of the antigen is 50 ku, detected by Western blot. The antigen is a key protein in the sperm acrosome reaction and may be the receptor of progesterone on the sperm acrosome. It may either be developed as a candidate contraceptive vaccine

  18. Antigen-specific monoclonal antibodies isolated from B cells expressing constitutively active STAT5.

    Directory of Open Access Journals (Sweden)

    Ferenc A Scheeren

    Full Text Available BACKGROUND: Fully human monoclonal antibodies directed against specific pathogens have a high therapeutic potential, but are difficult to generate. METHODOLOGY/PRINCIPAL FINDINGS: Memory B cells were immortalized by expressing an inducible active mutant of the transcription factor Signal Transducer and Activator of Transcription 5 (STAT5. Active STAT5 inhibits the differentiation of B cells while increasing their replicative life span. We obtained cloned B cell lines, which produced antibodies in the presence of interleukin 21 after turning off STAT5. We used this method to obtain monoclonal antibodies against the model antigen tetanus toxin. CONCLUSIONS/SIGNIFICANCE: Here we describe a novel and relatively simple method of immortalizing antigen-specific human B cells for isolation of human monoclonal antibodies. These results show that STAT5 overexpression can be employed to isolate antigen specific antibodies from human memory B cells.

  19. An update on antibody-based immunotherapies for Clostridium difficile infection

    Science.gov (United States)

    Hussack, Greg; Tanha, Jamshid

    2016-01-01

    Clostridium difficile continues to be one of the most prevalent hospital-acquired bacterial infections in the developed world, despite the recent introduction of a novel and effective antibiotic agent (fidaxomicin). Alternative approaches under investigation to combat the anaerobic Gram-positive bacteria include fecal transplantation therapy, vaccines, and antibody-based immunotherapies. In this review, we catalog the recent advances in antibody-based approaches under development and in the clinic for the treatment of C. difficile infection. By and large, inhibitory antibodies that recognize the primary C. difficile virulence factors, toxin A and toxin B, are the most popular passive immunotherapies under investigation. We provide a detailed summary of the toxin epitopes recognized by various antitoxin antibodies and discuss general trends on toxin inhibition efficacy. In addition, antibodies to other C. difficile targets, such as surface-layer proteins, binary toxin, motility factors, and adherence and colonization factors, are introduced in this review. PMID:27536153

  20. Anesthetic management of right atrial mass removal and pulmonary artery thrombectomy in a patient with primary antiphospholipid antibody syndrome

    Directory of Open Access Journals (Sweden)

    Rawat SKS

    2010-01-01

    Full Text Available Antiphospholipid antibody syndrome (APLAS characterises a clinical condition of arterial and venous thrombosis associated with phospholipids directed antibodies. APLAS occurs in 2% of the general population. However, one study demonstrated that 7.1% of hospitalised patients were tested positive for at least one of the three anticardiolipin antibody idiotype. Antiphospholipid antibodies often inhibit phospholipids dependent coagulation in vitro and interfere with laboratory testing of hemostasis. Therefore, the management of anticoagulation during cardiopulmonary bypass can be quite challenging in these patients. Here, we present a case of right atrial mass removal and pulmonary thrombectomy in a patient of APLAS.

  1. Effect of anti-carbohydrate antibodies on HIV infection in a monocytic cell line (U937)

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Clausen, H; Mathiesen, Lars Reinhardt; Nielsen, Jens Ole

    1991-01-01

    Monoclonal antibodies (mAbs) against carbohydrate epitopes of gp120 have recently been found to inhibit HIV infection of lymphocytes in vitro thereby opening new possibilities for vaccine considerations. Antibody-dependent enhancement of infection has however come increasingly into focus. This...... study therefore investigated the neutralization of HIV in a monocytic cell line (U937) using mAbs against these carbohydrate gp120-epitopes. While antibodies against one of the epitopes (AI) neutralized infection of U937 cells despite binding to the Fc-receptor, one mAb against the sialosyl-Tn epitope...

  2. Functional analysis of neutralizing antibodies against Clostridium perfringens epsilon-toxin.

    Science.gov (United States)

    McClain, Mark S; Cover, Timothy L

    2007-04-01

    The Clostridium perfringens epsilon-toxin causes a severe, often fatal illness (enterotoxemia) characterized by cardiac, pulmonary, kidney, and brain edema. In this study, we examined the activities of two neutralizing monoclonal antibodies against the C. perfringens epsilon-toxin. Both antibodies inhibited epsilon-toxin cytotoxicity towards cultured MDCK cells and inhibited the ability of the toxin to form pores in the plasma membranes of cells, as shown by staining cells with the membrane-impermeant dye 7-aminoactinomycin D. Using an antibody competition enzyme-linked immunosorbent assay (ELISA), a peptide array, and analysis of mutant toxins, we mapped the epitope recognized by one of the neutralizing monoclonal antibodies to amino acids 134 to 145. The antibody competition ELISA and analysis of mutant toxins suggest that the second neutralizing monoclonal antibody also recognizes an epitope in close proximity to this region. The region comprised of amino acids 134 to 145 overlaps an amphipathic loop corresponding to the putative membrane insertion domain of the toxin. Identifying the epitopes recognized by these neutralizing antibodies constitutes an important first step in the development of therapeutic agents that could be used to counter the effects of the epsilon-toxin. PMID:17261609

  3. Mechanistic insights into the neutralization of cytotoxic abrin by the monoclonal antibody D6F10.

    Directory of Open Access Journals (Sweden)

    Shradha Bagaria

    Full Text Available Abrin, an A/B toxin obtained from the Abrus precatorius plant is extremely toxic and a potential bio-warfare agent. Till date there is no antidote or vaccine available against this toxin. The only known neutralizing monoclonal antibody against abrin, namely D6F10, has been shown to rescue the toxicity of abrin in cells as well as in mice. The present study focuses on mapping the epitopic region to understand the mechanism of neutralization of abrin by the antibody D6F10. Truncation and mutational analysis of abrin A chain revealed that the amino acids 74-123 of abrin A chain contain the core epitope and the residues Thr112, Gly114 and Arg118 are crucial for binding of the antibody. In silico analysis of the position of the mapped epitope indicated that it is present close to the active site cleft of abrin A chain. Thus, binding of the antibody near the active site blocks the enzymatic activity of abrin A chain, thereby rescuing inhibition of protein synthesis by the toxin in vitro. At 1∶10 molar concentration of abrin:antibody, the antibody D6F10 rescued cells from abrin-mediated inhibition of protein synthesis but did not prevent cell attachment of abrin. Further, internalization of the antibody bound to abrin was observed in cells by confocal microscopy. This is a novel finding which suggests that the antibody might function intracellularly and possibly explains the rescue of abrin's toxicity by the antibody in whole cells and animals. To our knowledge, this study is the first report on a neutralizing epitope for abrin and provides mechanistic insights into the poorly understood mode of action of anti-A chain antibodies against several toxins including ricin.

  4. The development and specificity of antiidiotypic antibodies in renal transplant recipients receiving single-donor blood transfusions.

    Science.gov (United States)

    Phelan, D L; Rodey, G E; Anderson, C B

    1989-07-01

    Multiple pretransplant sera obtained from alloimmunized renal transplant recipients were tested for the presence of antiidiotypic-like antibodies (AB2) that inhibit donor-specific HLA antibodies in the microlymphocytotoxicity assay. Fourteen patients received repetitive single-donor blood transfusions (SDT). In this patient group, sera were collected prior to each blood transfusion and prior to transplantation. Three additional patients were studied in whom prior donor-specific HLA antibodies had been lost over a period of 6 months preceding transplantation. Donor-specific AB2-like antibodies were found in the sera of 13/14 SDT patients who did not develop HLA antibodies, and in the 3 patients who had lost donor-specific HLA antibodies. All patients had received prior random blood transfusions in the year preceding the study. Five (38%) of the SDT patients had detectable donor-specific AB2 prior to the initiation of single-donor blood transfusion, presumably related to previous blood transfusions. In the remaining six SDT patients in whom complete serum sets were available, AB2 always appeared after the first blood transfusion. The specificity of HLA antibodies inhibited by AB2 was studied, and antibodies against HLA-A, -B, -C, -DR, and DQw were all identified. Thus, there was no predilection for patients to develop AB2 against locus-specific HLA gene products. This study also confirms the apparent polymorphism of putative crossreactive idiotypes. Approximately 25% of donor-specific HLA antibodies were not inhibited by relevant AB2. This study confirms and extends previous observations that alloimmunization is associated in many patients with the development of antiidiotypic-like antibodies that are capable of inhibiting the binding and cytotoxicity of HLA alloantibodies. PMID:2473550

  5. Immunotherapy of hepatoma with a monoclonal antibody against murine endoglin

    Institute of Scientific and Technical Information of China (English)

    Guang-Hong Tan; Feng-Ying Huang; Hua Wang; Yong-Hao Huang; Ying-Ying Lin; Yue-Nan Li

    2007-01-01

    AIM: To explore the capability of a monoclonal antibody(mAb) against murine endoglin to inhibit tumor angiogenesis and suppression of hepatoma growth in murine models.METHODS: A monoclonal antibody against murine endoglin was purified by affinity chromatography and passively transfused through tail veins in two murine hepatoma models. Tumor volume and survival time were observed at three-day intervals for 48 d. Microvessels in tumor tissues were detected by immunohistochemistry against CD31, and angiogenesis in vivo was determined by alginate encapsulated assay. In addition, tumor cell apoptosis was detected by TUNEL assay.RESULTS: Passive immunotherapy with anti-endoglin mAb could effectively suppress tumor growth, and prolonged the survival time of hepatoma-bearing mice.Angiogenesis was apparently inhibited within the tumor tissues, and the vascularization of alginate beads was also reduced in the mice passively transfused with antiendoglin mAb. In addition, increased apoptotic cells were observed within the tumor tissues from the mice passively transfused with anti-endoglin mAb.CONCLUSION: Passive immunotherapy with antiendoglin mAb effectively inhibits tumor growth via inhibiting tumor angiogenesis and increasing tumor cell apoptosis, which may be highly correlated with the blockage of endoglin-related signal pathway induced by anti-endoglin mAb.

  6. Antibody fragments: Hope and hype

    OpenAIRE

    Nelson, Aaron L

    2010-01-01

    The antibody molecule is modular and separate domains can be extracted through biochemical or genetic means. It is clear from review of the literature that a wave of novel, antigen-specific molecular forms may soon enter clinical evaluation. This report examines the developmental histories of therapeutics derived from antigen-specific fragments of antibodies produced by recombinant processes. Three general types of fragments were observed, antigen-binding fragments (Fab), single chain variabl...

  7. The antineutrophil antibody in uveitis.

    OpenAIRE

    Young, D W

    1991-01-01

    Ninety eight patients with uveitis of various types were tested for the presence of the antineutrophil antibody or ANCA by an indirect immunofluorescence method. This antibody is found in patients with diseases associated with small vessel vasculitis, including Wegener's granulomatosis and microscopic polyarteritis. Eleven true positive cases were found. A positive test was not associated with the anatomical site of the uveitis but was related to the time course of the disease. In particular ...

  8. Interfacial metal and antibody recognition

    OpenAIRE

    Zhou, Tongqing; Hamer, Dean H.; Hendrickson, Wayne A.; Sattentau, Quentin J.; Kwong, Peter D.

    2005-01-01

    The unique ligation properties of metal ions are widely exploited by proteins, with approximately one-third of all proteins estimated to be metalloproteins. Although antibodies use various mechanisms for recognition, to our knowledge, none has ever been characterized that uses an interfacial metal. We previously described a family of CD4-reactive antibodies, the archetype being Q425. CD4:Q425 engagement does not interfere with CD4:HIV-1 gp120 envelope glycoprotein binding, but it blocks subse...

  9. Pyoderma gangrenosum and anticardiolipin antibody

    Directory of Open Access Journals (Sweden)

    de Godoy Jose Maria

    2006-01-01

    Full Text Available Pyoderma gangrenosum (PG is a rare ulceronecrotic inflammatory cutaneous disorder and is frequently associated with systemic diseases. The authors report a 22-year-old male patient with pyoderma gangrenosum, thrombosis of both popliteal arteries, ischemic stroke and seropositivity for anticardiolipin antibody. Despite intravenous treatment with antibiotics, corticosteroid and heparin, pyoderma gangrenosum caused necrosis of his right lower limb which resulted in amputation. It was concluded that the anticardiolipin antibody may have contributed to the gravity of this case.

  10. Th2 cytokines inhibit lymphangiogenesis.

    Directory of Open Access Journals (Sweden)

    Ira L Savetsky

    Full Text Available Lymphangiogenesis is the process by which new lymphatic vessels grow in response to pathologic stimuli such as wound healing, inflammation, and tumor metastasis. It is well-recognized that growth factors and cytokines regulate lymphangiogenesis by promoting or inhibiting lymphatic endothelial cell (LEC proliferation, migration and differentiation. Our group has shown that the expression of T-helper 2 (Th2 cytokines is markedly increased in lymphedema, and that these cytokines inhibit lymphatic function by increasing fibrosis and promoting changes in the extracellular matrix. However, while the evidence supporting a role for T cells and Th2 cytokines as negative regulators of lymphatic function is clear, the direct effects of Th2 cytokines on isolated LECs remains poorly understood. Using in vitro and in vivo studies, we show that physiologic doses of interleukin-4 (IL-4 and interleukin-13 (IL-13 have profound anti-lymphangiogenic effects and potently impair LEC survival, proliferation, migration, and tubule formation. Inhibition of these cytokines with targeted monoclonal antibodies in the cornea suture model specifically increases inflammatory lymphangiogenesis without concomitant changes in angiogenesis. These findings suggest that manipulation of anti-lymphangiogenic pathways may represent a novel and potent means of improving lymphangiogenesis.

  11. Antibodies to watch in 2014.

    Science.gov (United States)

    Reichert, Janice M

    2014-01-01

    Since 2010, mAbs has documented the biopharmaceutical industry's progress in transitioning antibody therapeutics to first Phase 3 clinical studies and regulatory review, and its success at gaining first marketing approvals for antibody-based products. This installment of the "Antibodies to watch" series outlines events anticipated to occur between December 2013 and the end of 2014, including first regulatory actions on marketing applications for vedolizumab, siltuximab, and ramucirumab, as well as the Fc fusion proteins Factor IX-Fc and Factor VIII-Fc; and the submission of first marketing applications for up to five therapeutics (secukinumab, ch14.18, onartuzumab, necitumumab, gevokizumab). Antibody therapeutics in Phase 3 studies are described, with an emphasis on those with study completion dates in 2014, including antibodies targeting interleukin-17a or the interleukin-17a receptor (secukinumab, ixekizumab, brodalumab), proprotein convertase subtilisin/kexin type 9 (alirocumab, evolocumab, bococizumab), and programmed death 1 receptor (lambrolizumab, nivolumab). Five antibodies with US Food and Drug Administration's Breakthrough Therapy designation (obinutuzumab, ofatumumab, lambrolizumab, bimagrumab, daratumumab) are also discussed. PMID:24284914

  12. Tabhu: tools for antibody humanization.

    KAUST Repository

    Olimpieri, Pier Paolo

    2014-10-09

    SUMMARY: Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can elicit unwanted and dangerous immunogenic responses. Antibody humanization methods are designed to produce molecules with a better safety profile still maintaining their ability to bind the antigen. This can be accomplished by grafting the non-human regions determining the antigen specificity into a suitable human template. Unfortunately, this procedure may results in a partial or complete loss of affinity of the grafted molecule that can be restored by back-mutating some of the residues of human origin to the corresponding murine ones. This trial-and-error procedure is hard and involves expensive and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps of the humanization experiment protocol. AVAILABILITY: http://www.biocomputing.it/tabhu CONTACT: anna.tramontano@uniroma1.it, pierpaolo.olimpieri@uniroma1.it SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

  13. Avian Diagnostic and Therapeutic Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, David Sherman [UND SMHS

    2012-12-31

    A number of infectious agents have the potential of causing significant clinical symptomology and even death, but dispite this, the number of incidence remain below the level that supports producing a vaccine. Therapeutic antibodies provide a viable treatment option for many of these diseases. We proposed that antibodies derived from West Nile Virus (WNV) immunized geese would be able to treat WNV infection in mammals and potential humans. We demonstrated that WNV specific goose antibodies are indeed successful in treating WNV infection both prophylactically and therapeutically in a golden hamster model. We demonstrated that the goose derived antibodies are non-reactogenic, i.e. do not cause an inflammatory response with multiple exposures in mammals. We also developed both a specific pathogen free facility to house the geese during the antibody production phase and a patent-pending purification process to purify the antibodies to greater than 99% purity. Therefore, the success of these study will allow a cost effective rapidly producible therapeutic toward clinical testing with the necessary infrastructure and processes developed and in place.

  14. Radiolabeled monoclonal antibodies: a review

    International Nuclear Information System (INIS)

    Since the description by Kohler and Milstein 1975 of their technique for producing monoclonal antibodies of predefined specificity, it has become a mainstay in most laboratories that utilize immunochemical techniques to study problems in basic, applied or clinical research. Paradoxically, the very success of monoclonal antibodies has generated a literature which is now so vast and scattered that it has become difficult to obtain a perspective. This brief review represents the distillation of many publications relating to the production and use of monoclonaal antibodies as radiopharmaceuticals. Significant advances were made possible in the last few years by combined developments in the fields of tumor-associated antigens and of monoclonal antibodies. In fact monoclonal antibodies against some well defined tumor-associated antigens, has led to significantly greater practical possibilities for producing highly specific radiolabeled antibodies as radiopharmaceuticals for diagnosis and therapy of human tumors. One of the main requirements of this methodology is the availability of stable radiopharmaceutical reagents which after labeling in vivo injection retain the capacity of specific interaction with the defined antigen and their molecular integrity. Since injection into human is the objetive of this kind of study all the specifications of radiopharmaceutical have to be fulfilled e.g. sterility, apirogenicity and absence of toxicity. (author)

  15. Radioimmunoguided surgery using monoclonal antibody

    International Nuclear Information System (INIS)

    The potential proficiency of radioimmunoguided surgery in the intraoperative detection of tumors was assessed using labeled monoclonal antibody B72.3 in 66 patients with tissue-proved tumor. Monoclonal antibody B72.3 was injected 5 to 42 days preoperatively, and the hand-held gamma-detecting probe was used intraoperatively to detect the presence of tumor. Intraoperative probe counts of less than 20 every 2 seconds, or tumor-to-adjacent normal tissue ratios less than 2:1 were considered negative (system failure). Positive probe counts were detected in 5 of 6 patients with primary colon cancer (83 percent), in 31 of 39 patients with recurrent colon cancer (79 percent), in 4 of 5 patients with gastric cancer (80 percent), in 3 of 8 patients with breast cancer (37.5 percent), and in 4 of 8 patients with ovarian cancer (50 percent) undergoing second-look procedures. Additional patients in each group were scored as borderline positive. Overall, radioimmunoguided surgery using B72.3 identified tumors in 47 patients (71.2 percent), bordered on positive in 6 patients (9.1 percent), and failed to identify tumor in 13 patients (19.7 percent). Improved selection of patients for antigen-positive tumors, the use of higher affinity second-generation antibodies, alternate routes of antibody administration, alternate radionuclides, and more sophisticatedly bioengineered antibodies and antibody combinations should all lead to improvements in radioimmunoguided surgery

  16. Monoclonal antibodies technology. Protocols

    International Nuclear Information System (INIS)

    Full text: Immunization. The first step in preparing useful monoclonal antibodies (MAbs) is to immunize an animal (Balb/c for example) with an appropriate antigen. Methods (only for soluble antigen): Solubilize selected antigen in Phosphate buffer solution (PBS) at pH 7.2-7.4, ideally at a final concentration per animal between 10 to 50 μg/ml. It is recommended that the antigen under consideration be incorporated into the emulsion adjuvants in 1:1 volumetric relation. We commonly use Frend's adjuvant (FA) to prepared immunized solution. The first immunization should be prepared with complete FA, and the another could be prepared with incomplete FA. It is recommended to inject mice with 0.2 ml intraperitoneal (ip) or subcutaneous (sc). Our experience suggests the sc route is the preferred route. A minimum protocol for immunizing mice to generate cells for preparing hybridomas is s follows: immunize sc on day 0, boost sc on day 21, take a trial bleeding on day 26; if antibody titters are satisfactory, boost ip on day 35 with antigen only, and remove the spleen to obtain cells for fusion on day 38. Fusion protocol. The myeloma cell line we are using is X63 Ag8.653. At the moment of fusion myeloma cells need a good viability (at least a 95%). 1. Remove the spleen cells from immunized mice using sterile conditions. An immune spleen should yield between 7 a 10x107 nucleated cells. 2. Place the spleen in 20 ml of serum-free RPMI 1640 in a Petri dish. Using a needle and syringe, inject the spleen with medium to distend and disrupt the spleen stroma and free the nucleated cells. 3. Flush the cell suspension with a Pasteur pipet to disperse clumps of cells. 4. Centrifuge the spleen cell suspension at 250g for 10 min. Resuspend the pellet in serum-free RPMI 1640. Determine cell concentration using Neuhabuer chamber. 5. Mix the myeloma cells and spleen cells in a conical 50-ml tube in serum-free RPMI 1640, 1 x107 spleen cells to 1x106 myeloma cells (ratio 10:1). Centrifuge

  17. Monoclonal antibodies for the detection of Puccinia striiformis urediniospores

    DEFF Research Database (Denmark)

    Skottrup, Peter; Frøkiær, Hanne; Hearty, Stephen; O'Kennedy, Richard; Hejgaard, Jørn; Nicolaisen, Mogens; Justesen, Annemarie Fejer

    2007-01-01

    The fungal pathogen Pst causes yellow rust disease in wheat plants leading to crop losses. The organism spreads by releasing wind-dispersed urediniospores from infected plants. In this study a library of novel monoclonal antibodies (mAbs) was developed against Pst urediniospores. Nine m......Ab-producing cell lines were cloned and their cross-reactivities characterised against a panel of airborne fungal spores representing genera commonly found in the same environment as Pst. Two specific mAbs were used to develop a competitive ELISA (Pst mAb4) and a subtractive inhibition ELISA (Pst mAb8). Standard...... curves for both assays had good intra- and interday reproducibility. The subtractive inhibition ELISA had greater sensitivity with a detection limit of 1.5 105 spores ml1. Cross-reactivity studies of Pst mAb8 in the subtractive inhibition ELISA, showed reaction with other Puccinia spores only, suggesting...

  18. Monoclonal antibodies to the human insulin receptor that activate glucose transport but not insulin receptor kinase activity

    Energy Technology Data Exchange (ETDEWEB)

    Forsayeth, J.R.; Caro, J.F.; Sinha, M.K.; Maddux, B.A.; Goldfine, I.D.

    1987-05-01

    Three mouse monoclonal antibodies were produced that reacted with the ..cap alpha.. subunit of the human insulin receptor. All three both immunoprecipitated /sup 125/I-labeled insulin receptors from IM-9 lymphocytes and competitively inhibited /sup 125/I-labeled insulin binding to its receptor. Unlike insulin, the antibodies failed to stimulate receptor autophosphorylation in both intact IM-9 lymphocytes and purified human placental insulin receptors. Moreover, unlike insulin, the antibodies failed to stimulate receptor-mediated phosphorylation of exogenous substrates. However, like insulin, two of the three antibodies stimulated glucose transport in isolated human adipocytes. One antibody, on a molar basis, was as potent as insulin. These studies indicate, therefore, that monoclonal antibodies to the insulin receptor can mimic a major function of insulin without activating receptor kinase activity. They also raise the possibility that certain actions of insulin such as stimulation of glucose transport may not require the activation of receptor kinase activity.

  19. Monoclonal antibodies to the human insulin receptor that activate glucose transport but not insulin receptor kinase activity

    International Nuclear Information System (INIS)

    Three mouse monoclonal antibodies were produced that reacted with the α subunit of the human insulin receptor. All three both immunoprecipitated 125I-labeled insulin receptors from IM-9 lymphocytes and competitively inhibited 125I-labeled insulin binding to its receptor. Unlike insulin, the antibodies failed to stimulate receptor autophosphorylation in both intact IM-9 lymphocytes and purified human placental insulin receptors. Moreover, unlike insulin, the antibodies failed to stimulate receptor-mediated phosphorylation of exogenous substrates. However, like insulin, two of the three antibodies stimulated glucose transport in isolated human adipocytes. One antibody, on a molar basis, was as potent as insulin. These studies indicate, therefore, that monoclonal antibodies to the insulin receptor can mimic a major function of insulin without activating receptor kinase activity. They also raise the possibility that certain actions of insulin such as stimulation of glucose transport may not require the activation of receptor kinase activity

  20. Efficacy of Wnt-1 monoclonal antibody in sarcoma cells

    International Nuclear Information System (INIS)

    Sarcomas are one of the most refractory diseases among malignant tumors. More effective therapies based on an increased understanding of the molecular biology of sarcomas are needed as current forms of therapy remain inadequate. Recently, it has been reported that Wnt-1/β-catenin signaling inhibits apoptosis in several cancers. In this study, we investigated the efficacy of a monoclonal anti-Wnt-1 antibody in sarcoma cells. We treated cell lines A-204, SJSA-1, and fresh primary cultures of lung metastasis of sarcoma with a monoclonal anti-Wnt-1 antibody. Wnt-1 siRNA treatment was carried out in A-204. We assessed cell death using Crystal Violet staining. Apoptosis induction was estimated by flow cytometry analysis (Annexin V and PI staining). Cell signaling changes were determined by western blotting analysis. We detected Wnt-1 expression in all tissue samples and cell lines. Significant apoptosis induction was found in monoclonal anti-Wnt-1 antibody treated cells compared to control monoclonal antibody treated cells (p < 0.02). Similarly, we observed increased apoptosis in Wnt-1 siRNA treated cells. Blockade of Wnt-1 signaling in both experiments was confirmed by analyzing intracellular levels of Dishevelled-3 and of cytosolic β-catenin. Furthermore, the monoclonal anti-Wnt-1 antibody also induced cell death in fresh primary cultures of metastatic sarcoma in which Wnt-1 signaling was active. Our results indicate that Wnt-1 blockade by either monoclonal antibody or siRNA induces cell death in sarcoma cells. These data suggest that Wnt-1 may be a novel therapeutic target for the treatment of a subset of sarcoma cells in which Wnt-1/β-catenin signaling is active

  1. Serrumab: a human monoclonal antibody that counters the biochemical and immunological effects of Tityus serrulatus venom.

    Science.gov (United States)

    Pucca, Manuela Berto; Zoccal, Karina Furlan; Roncolato, Eduardo Crosara; Bertolini, Thaís Barboza; Campos, Lucas Benício; Cologna, Camila Takeno; Faccioli, Lúcia Helena; Arantes, Eliane Candiani; Barbosa, José Elpidio

    2012-01-01

    In Brazil, the species Tityus serrulatus is responsible for the most severe cases of scorpion envenomation. There is currently a need for new scorpion anti-venoms that are more effective and less harmful. This study attempted to produce human monoclonal antibodies capable of inhibiting the activity of T. serrulatus venom (TsV), using the Griffin.1 library of human single-chain fragment-variable (scFv) phage antibodies. Four rounds of phage antibody selection were performed, and the round with the highest phage antibody titer was chosen for the production of monoclonal phage antibodies and for further analysis. The scFv 2A, designated serrumab, was selected for the production and purification of soluble antibody fragments. In a murine peritoneal macrophage cell line (J774.1), in vitro assays of the cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-10 were performed. In male BALB/c mice, in vivo assays of plasma urea, creatinine, aspartate transaminase, and glucose were performed, as well as of neutrophil recruitment and leukocyte counts. It was found that serrumab inhibited the TsV-induced increases in the production of IL-6, TNFα, and IL-10 in J774.1 cells. The in vivo inhibition assay showed that serrumab also prevented TsV-induced increases in the plasma levels of urea, creatinine, aspartate transaminase, and glucose, as well as preventing the TsV-induced increase in neutrophil recruitment. The results indicate that the human monoclonal antibody serrumab is a candidate for inclusion in a mixture of specific antibodies to the various toxins present in TsV. Therefore, serrumab shows promise for use in the production of new anti-venom. PMID:22424317

  2. Quantifying homologous and heterologous antibody titre rises after influenza virus infection.

    Science.gov (United States)

    Freeman, G; Perera, R A P M; Ngan, E; Fang, V J; Cauchemez, S; Ip, D K M; Peiris, J S M; Cowling, B J

    2016-08-01

    Most influenza virus infections are associated with mild disease. One approach to estimate the occurrence of influenza virus infections in individuals is via repeated measurement of humoral antibody titres. We used baseline and convalescent antibody titres measured by haemagglutination inhibition (HI) and viral neutralization (VN) assays against influenza A(H1N1), A(H3N2) and B viruses to investigate the characteristics of antibody rises following virologically confirmed influenza virus infections in participants in a community-based study. Multivariate models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following influenza A virus infections. In 122 participants with PCR-confirmed influenza A virus infection, homologous antibody titres rose by geometric means of 1·2- to 10·2-fold after infection with A(H1N1), A(H3N2) and A(H1N1)pdm09. Significant cross-reactions were observed between A(H1N1)pdm09 and seasonal A(H1N1). Antibody titre rises for some subtypes and assays varied by age, receipt of oseltamivir treatment, and recent receipt of influenza vaccination. In conclusion, we provided a quantitative description of the mean and variation in rises in influenza virus antibody titres following influenza virus infection. The multivariate patterns in boosting of antibody titres following influenza virus infection could be taken into account to improve estimates of cumulative incidence of infection in seroepidemiological studies. PMID:27018720

  3. Selection of apoptotic cell specific human antibodies from adult bone marrow.

    Directory of Open Access Journals (Sweden)

    Caroline Grönwall

    Full Text Available Autoreactive antibodies that recognize neo-determinants on apoptotic cells in mice have been proposed to have protective, homeostatic and immunoregulatory properties, although our knowledge about the equivalent antibodies in humans has been much more limited. In the current study, human monoclonal antibodies with binding specificity for apoptotic cells were isolated from the bone marrow of healthy adults using phage display technology. These antibodies were shown to recognize phosphorylcholine (PC-associated neo-determinants. Interestingly, three of the four identified apoptotic cell-specific antibody clones were encoded by VH3 region rearrangements with germline or nearly germline configuration without evidence of somatic hypermutation. Importantly, the different identified antibody clones had diverse heavy chain CDR3 and deduced binding surfaces as suggested by structure modeling. This may suggest a potentially great heterogeneity in human antibodies recognizing PC-related epitopes on apoptotic cells. To re-construct the postulated structural format of the parental anti-PC antibody, the dominant clone was also expressed as a recombinant human polymeric IgM, which revealed a substantially increased binding reactivity, with dose-dependent and antigen-inhibitable binding of apoptotic cells. Our findings may have implication for improved prognostic testing and therapeutic interventions in human inflammatory disease.

  4. Production of recombinant antibodies using bacteriophages

    OpenAIRE

    Shukra, A. M.; Sridevi, N. V.; Dev Chandran,; Kapil Maithal,

    2014-01-01

    Recombinant antibody fragments such as Fab, scFv, diabodies, triabodies, single domain antibodies and minibodies have recently emerged as potential alternatives to monoclonal antibodies, which can be engineered using phage display technology. These antibodies match the strengths of conventionally produced monoclonal antibodies and offer advantages for the development of immunodiagnostic kits and assays. These fragments not only retain the specificity of the whole monoclonal ...

  5. Antibody-Directed Phototherapy (ADP

    Directory of Open Access Journals (Sweden)

    M. Adil Butt

    2013-04-01

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

  6. Iminosugars Inhibit Dengue Virus Production via Inhibition of ER Alpha-Glucosidases-Not Glycolipid Processing Enzymes.

    Science.gov (United States)

    Sayce, Andrew C; Alonzi, Dominic S; Killingbeck, Sarah S; Tyrrell, Beatrice E; Hill, Michelle L; Caputo, Alessandro T; Iwaki, Ren; Kinami, Kyoko; Ide, Daisuke; Kiappes, J L; Beatty, P Robert; Kato, Atsushi; Harris, Eva; Dwek, Raymond A; Miller, Joanna L; Zitzmann, Nicole

    2016-03-01

    It has long been thought that iminosugar antiviral activity is a function of inhibition of endoplasmic reticulum-resident α-glucosidases, and on this basis, many iminosugars have been investigated as therapeutic agents for treatment of infection by a diverse spectrum of viruses, including dengue virus (DENV). However, iminosugars are glycomimetics possessing a nitrogen atom in place of the endocyclic oxygen atom, and the ubiquity of glycans in host metabolism suggests that multiple pathways can be targeted via iminosugar treatment. Successful treatment of patients with glycolipid processing defects using iminosugars highlights the clinical exploitation of iminosugar inhibition of enzymes other than ER α-glucosidases. Evidence correlating antiviral activity with successful inhibition of ER glucosidases together with the exclusion of alternative mechanisms of action of iminosugars in the context of DENV infection is limited. Celgosivir, a bicyclic iminosugar evaluated in phase Ib clinical trials as a therapeutic for the treatment of DENV infection, was confirmed to be antiviral in a lethal mouse model of antibody-enhanced DENV infection. In this study we provide the first evidence of the antiviral activity of celgosivir in primary human macrophages in vitro, in which it inhibits DENV secretion with an EC50 of 5 μM. We further demonstrate that monocyclic glucose-mimicking iminosugars inhibit isolated glycoprotein and glycolipid processing enzymes and that this inhibition also occurs in primary cells treated with these drugs. By comparison to bicyclic glucose-mimicking iminosugars which inhibit glycoprotein processing but do not inhibit glycolipid processing and galactose-mimicking iminosugars which do not inhibit glycoprotein processing but do inhibit glycolipid processing, we demonstrate that inhibition of endoplasmic reticulum-resident α-glucosidases, not glycolipid processing, is responsible for iminosugar antiviral activity against DENV. Our data suggest that

  7. Engineering and characterization of a humanized antibody targeting TNF-α and RANKL.

    Science.gov (United States)

    Wang, Jun; Du, Yuxuan; Qian, Hongyan; Yu, Haitao; Li, Shentao; Zhang, Xulong; Li, Zhanguo; Yuan, Huihui; Zhao, Wenming

    2014-07-18

    To neutralize the pathological activities of tumor necrosis factor-α (TNF-α) and receptor activator of NF-κB ligand (RANKL), we engineered and characterized a humanized 8G12 (h8G12) antibody that targeted TNF-α and RANKL. Standard molecular biological and complementarity determining region (CDR)-grafting techniques were used to engineer the h8G12 antibody, and enzyme-linked immunosorbent assays (ELISAs) and Western blotting were employed to determine its binding activation and specificity. TNF-α-mediated cytotoxicity and RANKL-induced osteoclastogenesis assays were used to evaluate the neutralizing effects of the antibody. The cDNA sequences were established by grafting the murine monoclonal antibody (mAb) 8G12 CDRs into the heavy and light chain (HC and LC) variable regions (VH and VL) of the human mAbs 3DGG_B and 1I9R_L, respectively. The recombinant plasmids were transfected into Chinese hamster ovary (CHO) cells to produce the h8G12 antibody, which could simultaneously recognize TNF-α and RANKL. In addition, the h8G12 antibody reduced the TNF-α-mediated apoptosis of L929 cells by 25.84%. Furthermore, the h8G12 antibody significantly inhibited leukocyte infiltration in a murine allergic contact inflammation model. Concurrent with the inhibition of apoptosis, the h8G12 antibody significantly reduced the number of osteoclast-like cells in a dose-dependent manner. These results demonstrated that the h8G12 antibody neutralized the activities of TNF-α and RANKL and that it might be a potential candidate for the treatment of inflammatory bone diseases, such as rheumatoid arthritis (RA). PMID:24950406

  8. Generation and Characterization of Novel Human IRAS Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2009-01-01

    Full Text Available Imidazoline receptors were first proposed by Bousquet et al., when they studied antihypertensive effect of clonidine. A strong candidate for I1R, known as imidazoline receptor antisera-selected protein (IRAS, has been cloned from human hippocampus. We reported that IRAS mediated agmatine-induced inhibition of opioid dependence in morphine-dependent cells. To elucidate the functional and structure properties of I1R, we developed the newly monoclonal antibody against the N-terminal hIRAS region including the PX domain (10–120aa through immunization of BALB/c mice with the NusA-IRAS fusion protein containing an IRAS N-terminal (10–120aa. Stable hybridoma cell lines were established and monoclonal antibodies specifically recognized full-length IRAS proteins in their native state by immunoblotting and immunoprecipitation. Monoclonal antibodies stained in a predominantly punctate cytoplasmic pattern when applied to IRAS-transfected HEK293 cells by indirect immunofluorescence assays and demonstrated excellent reactivity in flow immunocytometry. These monoclonal antibodies will provide powerful reagents for the further investigation of hIRAS protein functions.

  9. PCSK9 Antibodies for the Treatment of Hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Ioanna Gouni-Berthold

    2014-12-01

    Full Text Available The serine protease proprotein convertase subtilisin/kexin type 9 (PCSK9 binds to the low-density lipoprotein (LDL receptor (LDLR and directs it to lysosomes for intracellular degradation. This results in decreased numbers of LDLR available on the hepatic cell surface to bind LDL particles and remove them from the circulation and therefore to a subsequent increase in circulating LDL-cholesterol (LDL-C plasma levels. Since 2003, when the role of PCSK9 in LDL-C metabolism was discovered, there have been major efforts to develop efficient and safe methods to inhibit it. Amongst those, monoclonal antibodies against PCSK9 are the furthest in development, with multiple phase 3 trials already published and with cardiovascular endpoint trials currently underway. Two fully human monoclonal antibodies, evolocumab (AMG 145 and alirocumab (REGN727/SAR236553, have been extensively studied in a wide range of subjects, such as those with statin intolerance, as an add-on to statin therapy, as a monotherapy and in patients with familial hypercholesterolemia. PCSK9 antibodies result in a consistent and robust decrease in LDL-C plasma levels ranging from 40% to 70%, either on top of statins or as a monotherapy. If the safety data from the on-going phase 3 trials remain as reassuring as the data available till now, PCSK9 antibodies will offer a novel, powerful therapeutic option to decrease LDL-C plasma levels and, hopefully, cardiovascular risk.

  10. Mechanisms of resistance to HER family targeting antibodies

    International Nuclear Information System (INIS)

    The epidermal growth factor (EGF) family of receptor tyrosine kinases consists of four members: EGFR (HER1/ErbB1), HER2/neu (ErbB2), HER3 (ErbB3) and HER4 (ErbB4). Receptor activation via ligand binding leads to downstream signaling that influence cell proliferation, angiogenesis, invasion and metastasis. Aberrant expression or activity of EGFR and HER2 have been strongly linked to the etiology of several human epithelial cancers including but not limited to head and neck squamous cell carcinoma (HNSCC), non-small cell lung cancer (NSCLC), colorectal cancer (CRC), and breast cancer. With this, intense efforts have been made to inhibit the activity of the EGFR and HER2 by designing antibodies against the ligand binding domains (cetuximab, panitumumab and trastuzumab) or small molecules against the tyrosine kinase domains (erlotinib, gefitinib, and lapatinib). Both approaches have shown considerable clinical promise. However, increasing evidence suggests that the majority of patients do not respond to these therapies, and those who show initial response ultimately become refractory to treatment. While mechanisms of resistance to tyrosine kinase inhibitors have been extensively studied, resistance to monoclonal antibodies is less well understood, both in the laboratory and in the clinical setting. In this review, we discuss resistance to antibody-based therapies against the EGFR and HER2, similarities between these resistance profiles, and strategies to overcome resistance to HER family targeting monoclonal antibody therapy.

  11. Mechanisms of resistance to HER family targeting antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Kruser, Tim J. [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI (United States); Wheeler, Deric L., E-mail: dlwheeler@wisc.edu [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI (United States)

    2010-04-15

    The epidermal growth factor (EGF) family of receptor tyrosine kinases consists of four members: EGFR (HER1/ErbB1), HER2/neu (ErbB2), HER3 (ErbB3) and HER4 (ErbB4). Receptor activation via ligand binding leads to downstream signaling that influence cell proliferation, angiogenesis, invasion and metastasis. Aberrant expression or activity of EGFR and HER2 have been strongly linked to the etiology of several human epithelial cancers including but not limited to head and neck squamous cell carcinoma (HNSCC), non-small cell lung cancer (NSCLC), colorectal cancer (CRC), and breast cancer. With this, intense efforts have been made to inhibit the activity of the EGFR and HER2 by designing antibodies against the ligand binding domains (cetuximab, panitumumab and trastuzumab) or small molecules against the tyrosine kinase domains (erlotinib, gefitinib, and lapatinib). Both approaches have shown considerable clinical promise. However, increasing evidence suggests that the majority of patients do not respond to these therapies, and those who show initial response ultimately become refractory to treatment. While mechanisms of resistance to tyrosine kinase inhibitors have been extensively studied, resistance to monoclonal antibodies is less well understood, both in the laboratory and in the clinical setting. In this review, we discuss resistance to antibody-based therapies against the EGFR and HER2, similarities between these resistance profiles, and strategies to overcome resistance to HER family targeting monoclonal antibody therapy.

  12. Antibodies to watch in 2016.

    Science.gov (United States)

    Reichert, Janice M

    2016-01-01

    The number of novel antibody therapeutics that received first marketing approvals in 2015 met expectations, with 6 (alirocumab (Praluent®), evolocumab (Repatha®), daratumumab (Darzalex®), dinutuximab (Unituxin®), idarucizumab (Praxbind®), mepolizumab (Nucala®)) granted first approvals as of mid-November*. Seven novel antibody therapeutics (begelomab, brodalumab, elotuzumab, ixekizumab, necitumumab, obiltoxaximab, reslizumab) are in regulatory review, and thus a similar number, if not more, are projected to gain first approvals in 2016. Commercial late-stage antibody therapeutics development exceeded expectations by increasing from 39 candidates in Phase 3 studies as of late 2014 to 53 as of late 2015. Of the 53 candidates, transitions to regulatory review by the end of 2016 are projected for 8 (atezolizumab, benralizumab, bimagrumab, durvalumab, inotuzumab ozogamicin, lebrikizumab, ocrelizumab, tremelimumab). Other "antibodies to watch" include 15 candidates (bavituximab, bococizumab, dupilumab, fasinumab, fulranumab, gevokizumab, guselkumab, ibalizumab, LY2951742, onartuzumab, REGN2222, roledumab, romosozumab, sirukumab, Xilonix) undergoing evaluation in Phase 3 studies that have estimated primary completion dates in 2016. As evidenced by the antibody therapeutics discussed in this perspective, the biopharmaceutical industry has a highly active late-stage clinical pipeline that may deliver numerous new products to the global market in the near future. *See Note added in proof for updates through December 31, 2015. PMID:26651519

  13. Characterization of Inhibitory Anti-insulin-like Growth Factor Receptor Antibodies with Different Epitope Specificity and Ligand-blocking Properties: IMPLICATIONS FOR MECHANISM OF ACTION IN VIVOS⃞

    OpenAIRE

    Doern, Adam; Cao, Xianjun; Sereno, Arlene; Reyes, Christopher L.; Altshuler, Angelina; Huang, Flora; Hession, Cathy; Flavier, Albert; Favis, Michael; Tran, Hon; Ailor, Eric; Levesque, Melissa; MURPHY, TRACEY; Berquist, Lisa; Tamraz, Susan

    2009-01-01

    Therapeutic antibodies directed against the type 1 insulin-like growth factor receptor (IGF-1R) have recently gained significant momentum in the clinic because of preliminary data generated in human patients with cancer. These antibodies inhibit ligand-mediated activation of IGF-1R and the resulting down-stream signaling cascade. Here we generated a panel of antibodies against IGF-1R and screened them for their ability to block the binding of both IGF-1 and IGF-2 at es...

  14. New-onset mediastinal and central nervous system sarcoidosis in a patient with metastatic melanoma undergoing CTLA4 monoclonal antibody treatment.

    LENUS (Irish Health Repository)

    Murphy, Kevin P

    2014-01-01

    Ipilimumab, a cytotoxic monoclonal antibody that inhibits cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), has been established as an effective therapy in the management of advanced melanoma. Immune-mediated adverse events are a common side effect.

  15. Osthole prevents anti-Fas antibody-induced hepatitis in mice by affecting the caspase-3-mediated apoptotic pathway.

    Science.gov (United States)

    Okamoto, Toshihiro; Kawasaki, Toru; Hino, Okio

    2003-02-15

    Fas (Apo-1/CD95) ligand, which is a type II membrane protein, is a major inducer of apoptosis. Osthole is a coumarin derivative present in medicinal plants. The effect of osthole on hepatitis induced by anti-Fas antibody in mice was studied. Pretreatment of mice with osthole (10, 50, and 100 mg/kg, i.p.) prevented the elevation of plasma alanine aminotransferase (ALT) caused by anti-Fas antibody (175 microg/kg, i.v.). Administration of osthole to mice even at a dose of 10 mg/kg significantly inhibited of anti-Fas antibody-induced elevation of plasma ALT. Capase-3 is a cysteine protease, and treatment of mice with anti-Fas antibody caused an elevation of caspase-3 activity at 3.5 and 6 hr. Pretreatment of mice with osthole (100 mg/kg, i.p.) inhibited the elevation of caspase-3 activity caused by anti-Fas antibody. However, the addition of osthole (up to 10(-4)M) to a liver cytosol fraction isolated from mice treated with anti-Fas antibody did not inhibit caspase-3 activity in vitro. Thus, treatment of mice with osthole inhibited caspase-3 activity by an effect upstream of caspase-3 activation. The livers of mice treated with anti-Fas antibody contained apoptotic and dead cells; osthole attenuated the development of this apoptosis and cell death. The present results show that osthole prevented anti-Fas antibody-induced hepatitis by inhibiting the Fas-mediated apoptotic pathway. PMID:12566097

  16. Preparation of an antibody that recognizes and neutralizes Dictyostelium differentiation-inducing factor-1.

    Science.gov (United States)

    Kubohara, Yuzuru; Kikuchi, Haruhisa; Nakamura, Koji; Matsuo, Yusuke; Oshima, Yoshiteru

    2010-05-28

    In the development of the cellular slime mold Dictyostelium discoideum, the differentiation-inducing factor-1 (DIF-1; 1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl)hexan-1-one) plays an important role in the regulation of cell differentiation and chemotaxis; however, the cellular signaling systems involving DIF-1 remain to be elucidated. To obtain a probe for DIF-1, we synthesized a DIF derivative (DIF-1-NH(2); 6-amino-1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl)hexan-1-one), and prepared an anti-DIF-1 antibody using a DIF-1-NH(2)-conjugated macromolecule as the immunogen. A 100-fold dilution of the antibody bound to DIF-1-NH(2)-conjugated resin, and this binding was inhibited by co-addition of 20 microM DIF-1 or DIF-1-NH(2). In a monolayer culture of HM44 cells, a DIF-deficient D. discoideum strain, 0.5 nM exogenous DIF-1 induced stalk cell formation in approximately 60% of the cells; this induction was dose-dependently inhibited by the antibody (diluted 12.5- or 25-fold). Furthermore, this inhibition by the antibody was recovered by co-addition of 2.5 or10 nM DIF-1. The results indicate that the anti-DIF-1 antibody recognizes DIF-1 and neutralizes its function. PMID:20416278

  17. Production of a macromomycin (MCR-monoclonal antibody conjugate and its biological activity.

    Directory of Open Access Journals (Sweden)

    Manabe,Yuichi

    1984-04-01

    Full Text Available Macromomycin (MCR, an unique membrane-reactive anticancer antibiotic, was incubated with murine monoclonal anti-HLA IgG1 antibody (H-1 in the presence of carbodiimide. The resulting mixture was fractionated with a Sephadex G-200 column. The first and second fractions were shown to contain MCR-(H-1 conjugate by the elution profile, as well as by the Sarcina lutea growth inhibition assay and Ouchterlony double-diffusion method. A membrane immunofluorescence test with anti-MCR and anti-mouse IgG antibodies demonstrated specific localization of MCR-(H-1 on the surface of HLA-bearing NALL -1 cells. MCR-(H-1 inhibited the growth of HLA-lacking NS-1 cells statistically less effectively than MCR alone (p less than 0.01. On the other hand, the conjugate and free MCR equally inhibited the growth and 3H-TdR incorporation of HLA-bearing NALL -1 cells. These results indicate that the antibody-bound MCR retained both MCR and antibody activities, and thus exerted antibody-targeting MCR cytotoxicity in vitro.

  18. Autologous antibodies that bind neuroblastoma cells.

    Science.gov (United States)

    Sun, Yujing; Sholler, Giselle S; Shukla, Girja S; Pero, Stephanie C; Carman, Chelsea L; Zhao, Ping; Krag, David N

    2015-11-01

    Antibody therapy of neuroblastoma is promising and our goal is to derive antibodies from patients with neuroblastoma for developing new therapeutic antibodies. The feasibility of using residual bone marrow obtained for clinical indications as a source of tumor cells and a source of antibodies was assessed. From marrow samples, neuroblastoma cells were recovered, grown in cell culture and also implanted into mice to create xenografts. Mononuclear cells from the marrow were used as a source to generate phage display antibody libraries and also hybridomas. Growth of neuroblastoma patient cells was possible both in vitro and as xenografts. Antibodies from the phage libraries and from the monoclonal hybridomas bound autologous neuroblastoma cells with some selectivity. It appears feasible to recover neuroblastoma cells from residual marrow specimens and to generate human antibodies that bind autologous neuroblastoma cells. Expansion of this approach is underway to collect more specimens, optimize methods to generate antibodies, and to evaluate the bioactivity of neuroblastoma-binding antibodies. PMID:26210205

  19. Antisperm antibodies and in vitro fertilization.

    Science.gov (United States)

    Janssen, H J; Bastiaans, B A; Goverde, H J; Hollanders, H M; Wetzels, A A; Schellekens, L A

    1992-08-01

    The purpose of this study was to investigate the influence of antisperm antibodies in the male, the female, or both partners on the outcome of in vitro fertilization treatment. The results in terms of ongoing pregnancies in the male and female antibody-positive group were the same as in the antibody-negative group. In the double antibody-positive group two of the three patients became pregnant. When high levels of antisperm antibodies were present on the spermatozoa, the fertilization rate was significantly reduced. In the female positive group no clear relationship between the antibody titer and the fertilization percentage could be detected. Abnormal semen quality was responsible for a much lower fertilization rate than the presence of antibodies. The conclusion of this study is that in vitro fertilization provides an equal change of conception in couples with antisperm antibodies in comparison with couples with no antibodies if the other semen parameters are normal. PMID:1472812

  20. Remembering antibodies coming of age.

    Science.gov (United States)

    Melchers, Fritz

    2016-01-01

    Fifty years ago, Norbert Hilschmann discovered that antibodies have variable immunoglobulin domains to bind antigens, and constant domains to carry out effector functions in the immune system. Just as this happened, the author of this perspective entered the field of immunology. Ten years later, the genetic basis of antibody variability was discovered by Susumu Tonegawa and his colleagues at the Basel Institute for Immunology, where the author had become a scientific member. At the same time, Georges Köhler, a former graduate student of the author's at the Basel Institute, invented with Cesar Milstein at the Laboratory of Molecular Biology in Cambridge, England, the method to produce monoclonal antibodies. The author describes here his memories connected to these three monumental, paradigm-changing discoveries, which he observed in close proximity. PMID:27144253

  1. Molecular-specific urokinase antibodies

    Science.gov (United States)

    Atassi, M. Zouhair (Inventor); Morrison, Dennis R. (Inventor)

    2009-01-01

    Antibodies have been developed against the different molecular forms of urokinase using synthetic peptides as immunogens. The peptides were synthesized specifically to represent those regions of the urokinase molecules which are exposed in the three-dimensional configuration of the molecule and are uniquely homologous to urokinase. Antibodies are directed against the lysine 158-isoleucine 159 peptide bond which is cleaved during activation from the single-chain (ScuPA) form to the bioactive double chain (54 KDa and 33 KDa) forms of urokinase and against the lysine 135 lysine 136 bond that is cleaved in the process of removing the alpha-chain from the 54 KDa form to produce the 33 KDa form of urokinase. These antibodies enable the direct measurement of the different molecular forms of urokinase from small samples of conditioned medium harvested from cell cultures.

  2. Control of IgE and IgGl antibody production in mice

    International Nuclear Information System (INIS)

    The production of IgE and IgCl was studied in untreated, thymectomized, splenectomized, anti-thymocyte serum-treated, or sublethally X-irradiated mice. Dinitrophenyl, Ascaris, and ovalbumin were used as antigens, and aluminum hydroxide was used as adjuvant. A suppression of IgE production was observed in adult thymectomized mice, although the kinetic pattern of the antibody response was the same as in control animals. IgGl antibody production was not affected by thymectomy. Splenectomy did not change either IgE or IgGl production. A single dose of rabbit antithymocyte serum (ATS) given 8 days after immunization inhibited IgE antibody production. The effect of ATS was dose dependent and also varied with the amount of antigen used, the immune response to high doses being more susceptible to the effect of ATS. No alteration in IgGl production was caused by ATS even when IgE antibody formation was completely inhibited. When preceding immunization, sublethal irradiation enhanced IgE antibody formation and partially suppressed IgGl production; applied after immunization, irradiation caused an enhancement of IgE production which was inversely proportional to the interval elapsed between the two procedures. On the other hand, the IgGl antibody production was fairly resistant to the same treatment. The results suggest a clearcut separation between the mechanisms regulating IgE and IgGl production in mice

  3. Antibody Response to Pneumocystis jirovecii

    OpenAIRE

    Daly, Kieran R.; Huang, Laurence; Morris, Alison; Koch, Judy; Crothers, Kristina; Levin, Linda; Eiser, Shary; Satwah, Supriya; Zucchi, Patrizia; Walzer, Peter D.

    2006-01-01

    We conducted a prospective pilot study of the serologic responses to overlapping recombinant fragments of the Pneumocystis jirovecii major surface glycoprotein (Msg) in HIV-infected patients with pneumonia due to P. jirovecii and other causes. Similar baseline geometric mean antibody levels to the fragments measured by an ELISA were found in both groups. Serum antibodies to MsgC in P. jirovecii patients rose to a peak level 3–4 weeks (p50 cells/μL and first episode of pneumocystosis were the ...

  4. Radioimmunotherapy with engineered antibody fragments

    International Nuclear Information System (INIS)

    Authors have developed and begun evaluating radiometal-chelated (213Bi) engineered antibody fragments as radioimmunotherapy agents that target the HER2/neu (c-erbB-2) antigen. The diabody format was found to have 40-fold greater affinity for HER2/neu and to be associated with significantly greater tumor localization than is achieved with scFv molecule. It is shown that short-lived isotopes like 213Bi would be most effective when used in conjunction with antibodies that targeted diffuse malignancies (leukemia or lymphoma) or when used for very rapid pretargeted radioimmunotherapy application in which the radioisotope is conjugated to a very small ligand

  5. Antibody sensed protein surface conformation

    Directory of Open Access Journals (Sweden)

    Scott R. Schricker

    2011-12-01

    Full Text Available An antibody-modified atomic force microscope (AFM tip was used to detect conformational changes of fibronectin deposited on a poly(methyl methacrylate/poly(acrylic acid block copolymer compared to PMMA and a random poly(methyl methacrylate/poly(acrylic acid copolymer with an identical chemical composition. Based on the antibody-protein adhesive force maps and phase imaging, it was found that the nanomorphology of the triblock copolymer induces the desired conformation of fibronectin. This finding demonstrates that block copolymer nanomorphology can be used to regulate protein conformation and potentially cellular response.

  6. Antibody response to hidden epitope of influenza a hemagglutinin elicited by anti-idiotypic antibodies

    International Nuclear Information System (INIS)

    Monoclonal antibody (MoAb) IIF4 defines an epitope on the HA2 part of influenza hemagglutinin (HA)It was also found this epitope becomes fully accessible after pH 5 treatment of the antigen and is shared by strains of H3 subtype. In this study we found binding of MoAb IIF4 also to some strains belonging to H2, H4, H7, and H10 subtypes. We prepared rabbit polyclonal anti-IIF4 anti-idiotype (anti-Id) antibody. In competitive assays, the inhibition potential of anti-Id was considerably higher than that of native HA. Anti-Id was used for the preparation of mouse Ab3 (anti-anti-IIF4) serum. Reactivity pattern of Ab3 with influenza virus strains differed from Ab1 in in (i) appearance of binding to some strains of H2 and H7 subtype and (ii) decreased dependency of Ab3 binding on the pH forms of antigen. The reactivity of Ab1 and Ab3 with two amantadine-resistant virus mutants indicates that IIF4 epitope (and its related region recognized by Ab3) becomes accessible in consequence of destabilization of trimeric arrangement of HA and it it also correlates with expulsion of N-terminus of HA2. (author)

  7. Osteogenic Inhibition in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Nasim Kalantari

    2013-01-01

    results also show that based on SOST expression in MM, there is a potential to inhibit sclerostin with antibody or alternative methods and prevent bone lesion in MM patients with the least side effect.

  8. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A; Thompson, Vicki S

    2013-02-26

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  9. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S.

    2013-02-26

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  10. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S

    2010-04-13

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  11. Antibody profiling sensitivity through increased reporter antibody layering

    International Nuclear Information System (INIS)

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  12. The interaction of thyroid-stimulating antibodies with solubilised human thyrotrophin receptors

    International Nuclear Information System (INIS)

    Thyroid receptors for thyrotrophin (TSH) and thyroid-stimulating antibodies (TSAb) are closely related as indicated by the ability of TSAb to inhibit the binding of labelled TSH to thyroid membranes and to isolated thyroid cells. The effect of TSAb on the TSH-TSH receptor interaction may be due to direct binding of the antibody to the TSH receptor. Alternatively, TSAb may bind to a site different from the TSH receptor in such a way as to induce changes in the thyroid membrane and cause inactivation of the TSH receptor. In order to investigate these two possibilities the interaction between TSAb and solubilised human TSH receptors was studied. The data found indicate that TSAb inhibits the binding of labelled TSH to soluble TSH receptors and provide evidence for the concept that TSAb is an antibody to the TSH receptor

  13. Propylthiouracil induced anti-neutrophil cytoplasmic antibody-associated vasculitis with bone marrow plasmacytosis andgranulocytopenia

    Institute of Scientific and Technical Information of China (English)

    Abdullah Ozkok

    2009-01-01

    @@ Antithyroid drugs are molecules known as thionamides that inhibit thyroid hormone synthesis by interfering with thyroid peroxidase mediated iodination of tyrosine residues in thyroglobulin. These extensively used drugs are associated with a variety of well-known side effects such as anti-neutrophil cytoplasmic antibody (ANCA)-positive vasctilitis, granulocytopenia and aplastic anemia.

  14. Monoclonal antibodies for rapid, strain-specific identification of influenza virus isolates.

    OpenAIRE

    Schmidt, N. J.; Ota, M; Gallo, D; Fox, V L

    1982-01-01

    Monoclonal antibodies conjugated with fluorescein permitted rapid, strain-specific identification of influenza A isolates and type-specific identification of influenza B isolates by direct immunofluorescence staining. Identification of H1 influenza A strains could be accomplished by direct immunofluorescence on cell culture fluids lacking sufficient hemagglutinin activity to permit identification by hemagglutination inhibition.

  15. Generation of anti-idiotype scFv for pharmacokinetic measurement in lymphoma patients treated with chimera anti-CD22 antibody SM03.

    Directory of Open Access Journals (Sweden)

    Qi Zhao

    Full Text Available Pre-clinical and clinical studies of therapeutic antibodies require highly specific reagents to examine their immune responses, bio-distributions, immunogenicity, and pharmacodynamics in patients. Selective antigen-mimicking anti-idiotype antibody facilitates the assessment of therapeutic antibody in the detection, quantitation and characterization of antibody immune responses. Using mouse specific degenerate primer pairs and splenocytic RNA, we generated an idiotype antibody-immunized phage-displayed scFv library in which an anti-idiotype antibody against the therapeutic chimera anti-CD22 antibody SM03 was isolated. The anti-idiotype scFv recognized the idiotype of anti-CD22 antibody and inhibited binding of SM03 to CD22 on Raji cell surface. The anti-idiotype scFv was subsequently classified as Ab2γ type. Moreover, our results also demonstrated firstly that the anti-idiotype scFv could be used for pharmacokinetic measurement of circulating residual antibody in lymphoma patients treated with chimera anti-CD22 monoclonal antibody SM03. Of important, the present approach could be easily adopted to generate anti-idiotype antibodies for therapeutic antibodies targeting membrane proteins, saving the cost and time for producing a soluble antigen.

  16. Highly sensitive solid-phase radioimmunoassay for the assay of Plasmodium falciparum antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Avraham, H.; Golenser, J.; Gazitt, Y.; Spira, D.T.; Sulitzeanu, D. (Hebrew Univ., Jerusalem (Israel). Hadassah Medical School)

    1982-08-27

    A highly sensitive radioimmunoassay for detection of P. falciparum antibodies and antigens is described. A partially purified P. falciparum antigen preparation is obtained from in vitro cultured parasites enriched after gelatin sedimentation by sonicating the infected red blood cells and precipitating the proteins with 50% saturated ammonium sulfate. The precipitate is dissolved in buffer, ultracentrifuged and used to coat wells of microtiter plates. Anti-P. falciparum antibodies are detected by incubating antiserum dilutions in the coated wells and detecting the bound IgG with radioiodinated staphylococcal protein A. P. falciparum antigens are detected by their ability to inhibit binding of antibodies to the coated wells. Sera of individuals with a history of P. falciparum infection contain antibodies detectable at a dilution of 1:75,000. P. falciparum RBC infected in vitro can be detected at levels of parasitemia of the order of 1 parasite or less per 10/sup 6/ RBC.

  17. Isotype profiles of anti-influenza antibodies in mice bearing the xid defect

    International Nuclear Information System (INIS)

    The humoral response to influenza A/PR8 virus was examined in the CAB/N and C3J.xid strains of mice, both of which bear an X-linked genetic defect (xid), and in strains lacking this defect. Hemagglutination-inhibiting antibody titers and measurement of virus-specific antibodies by solid-phase radioimmunoassay indicated that the xid defect does not impair the production of an adequate anti-influenza antibody response. However, investigation of the isotopes of PR8 virus-specific antibodies disclosed a relative decrease in the levels of IgG3 and IgG1 in the xid-bearing strains. This was observed after both intraperitoneal immunization and aerosol infection. The isotope differences were not reflected in the susceptibility of these strains to influenza virus infection

  18. Mycofix ameliorative effect on Newcastle disease antibody production in broiler chickens during aflatoxicosis

    Directory of Open Access Journals (Sweden)

    M. T. Gargees

    2008-01-01

    Full Text Available Three experiments were conducted to elucidate the alleviation effects of Mycofix plus 3.0 on Newcastle antibody formation during aflatoxicosis in broiler chickens. Three levels of Mycofix (0.05%, 0.15%, and 0.25% and aflatoxin (2.5ppm, 3.5ppm, and 5ppm were used. Chickens were vaccinated at 8 and 18 days of age. Enzyme-linked immunosorbent assay and Haemagglutination inhibition tests were employed for determination Newcastle antibody titers at 28 days. The results showed that, Mycofix , and only at its high level of addition (0.25% was effective in ameliorating the negative effect of aflatoxin at the rates 2.5ppm and 3.5 ppm levels of inclusion on antibody production but not at the high level of 5ppm on antibody production, comparing with titers in control groups.

  19. Induction of multi-epitope specific antibodies against HIV-1 by multi-epitope vaccines

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some neutralizing antibodies against HIV-1 envelope proteins were highly effective to inhibit the infection of different strains in vitro, and existed in the infected individuals with very low levels. We suggested multi-epitope-vaccine as a new strategy to increase levels of neutralizing antibodies and the abilities against HIV mutation in vivo. Two candidate multi-epitope-vaccines induced antibodies with predefined multi-epitope-specificity in rhesus macaque. These antibodies recognized corresponding neutralizing epitopes on epitope-peptides, gp41 peptides, V3 loop peptide, rsgp41 and rgp120. Besides, three candidate epitope-vaccines in combination (another kind of multi-epitopevaccines) showed similar potency to induce predefined multiple immune responses in rabbits. These results suggest that multi-epitope-vaccines may be a new strategy to induce multi-antiviral activities against HIV-1 infection and mutafions.

  20. Antibody-coated protein A-bearing Staphylococcus aureus: a versatile and stable immune reagent

    International Nuclear Information System (INIS)

    The human β2-microglobulin antigen-antibody system was used as a model to illustrate the versatility of a microradioimmunoassay technique using protein A-bearing Staphylococcus aureus Cowan I strain (SACI) bacteria as a non-specific immunoadsorbent in place of a second antibody. Experimental conditions are described for a sensitive microassay which makes it possible to process large numbers of samples more rapidly and with minimum handling. Furthermore, SACI coated with specific antibodies by mixing with unfractionated antisera are a versatile reagent not only for radioimmunoassays but also for use as molecular probes to characterize cell surface antigens. Antibody-coated SACI could be lyophilized and proved extremely stable in storage thus providing a unique advantage for use in binding inhibition assays and as versatile reagent for clinical and investigative immunology. (Auth.)

  1. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    better understand the underlying mechanisms of antibody-antigen interaction here we present a pipeline developed by us to structurally classify immunoglobulin antigen binding sites and to infer key sequence residues and other variables that have a prominent role in each structural class....

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lin-Xu [Nebraska Center for Virology, Lincoln, NE (United States); School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, NE 68583 (United States); Mellon, Michael [Nebraska Center for Virology, Lincoln, NE (United States); School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE (United States); Bowder, Dane [Nebraska Center for Virology, Lincoln, NE (United States); School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, NE 68583 (United States); Quinn, Meghan [Nebraska Center for Virology, Lincoln, NE (United States); School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE (United States); Shea, Danielle; Wood, Charles [Nebraska Center for Virology, Lincoln, NE (United States); School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, NE 68583 (United States); Xiang, Shi-Hua, E-mail: sxiang2@unl.edu [Nebraska Center for Virology, Lincoln, NE (United States); School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE (United States)

    2015-01-15

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

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

    International Nuclear Information System (INIS)

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

  4. Prevalence of antibodies to canine parvovirus and reaction to vaccination in client-owned, healthy dogs.

    Science.gov (United States)

    Riedl, M; Truyen, U; Reese, S; Hartmann, K

    2015-12-12

    The purpose of this population-based cohort study was to assess current prevalence of antibodies to canine parvovirus (CPV) in adult, healthy dogs, including risk factors associated with lack of antibodies, and reaction to revaccination with a modified live vaccine (MLV). One hundred dogs routinely presented for vaccination were included in the study and vaccinated with a single dose of a combined MLV. Information was collected on signalment, origin, environment, vaccination history and side effects. Prevaccination and postvaccination antibodies were detected by haemagglutination inhibition. Univariate analysis, followed by multivariate logistic regression, was used to investigate association between different variables and presence of antibodies as well as titre increase. Protective CPV antibodies were present in 86.0 per cent of dogs. Intervals of more than four years since the last vaccination and rare contacts with other dogs were determined as main risk factors for the absence of antibodies. An increase in titres only occurred in 17.0 per cent of dogs. Dogs without protective titres before vaccination or with bodyweight <10 kg were more likely to have an adequate titre increase. Based on these findings, antibody status should be determined instead of periodic vaccinations to ensure reliable protection without unnecessary vaccinations in adult dogs. PMID:26514756

  5. Ibrutinib interferes with the cell-mediated anti-tumor activities of therapeutic CD20 antibodies: implications for combination therapy

    DEFF Research Database (Denmark)

    Da Roit, F.; Engelberts, P. J.; Taylor, R. P.;

    2015-01-01

    The novel Bruton tyrosine kinase inhibitor ibrutinib and phosphatidyl-4-5-biphosphate 3-kinase-delta inhibitor idelalisib are promising drugs for the treatment of chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma, either alone or in combination with anti-CD20 antibodies. We investigated...... the possible positive or negative impact of these drugs on all known mechanisms of action of both type I and type II anti-CD20 antibodies. Pretreatment with ibrutinib for 1 hour did not increase direct cell death of cell lines or chronic lymphocytic leukemia samples mediated by anti-CD20 antibodies....... Pre-treatment with ibrutinib did not inhibit complement activation or complement-mediated lysis. In contrast, ibrutinib strongly inhibited all cell-mediated mechanisms induced by anti-CD20 antibodies rituximab, ofatumumab or obinutuzumab, either in purified systems or whole blood assays. Activation of...

  6. Radioimmunoassay of human serum antibody specific for adenovirus type 5-purified fiber

    International Nuclear Information System (INIS)

    A radioimmunoassay (RIA), utilizing a second antibody to separate immune complexes, was developed to provide a sensitive and specific measure of serum antibody to adenovirus type 5 (Ad 5) fiber. Purity of fiber antigen was ascertained by sodium dodecyl sulfate urea-polyacrylamide gel electrophoresis and isoelectric focusing in ampholyte pH gradients. After labeling with 125I to high specific activity, the iodinated fiber did not exhibit loss of antigenic reactivity and remained stable for 3 weeks when stored at --200C with supplemental protein. Rabbit anti-Ad 5 serum with a neutralization titer of 1:320 precipitated 50 percent of the labeled fiber at a serum dilution of 1:50,000 when tested by the RIA. In competition assays as little as 0.5 ng of unlabeled fiber per milliliter was sufficient to inhibit the 125I fiber-antibody reaction. Serum specimens from 20 volunteers, obtained before and after vaccination with purified Ad 5 fiber or hexon subunit vaccine, were tested by RIA, hemagglutination-inhibition (HI), and neutralization tests. A comparison of mean antibody titers of post-inoculation sera showed that the RIA was 300 and 1000 times more sensitive than the HI and neutralization tests, respectively. Moreover, 19 of the men who were negative by the standard serologic tests before vaccination were shown to have anti-fiber antibody, with a mean RIA titer of 1:1028. Specificity of the RIA was demonstrated by the lack of an increase in antibody to Ad 5 fiber among those individuals vaccinated with the hexon subunit. Thus, the development of a highly sensitive and reproducible RIA allows for the detection of antibody specific for the Ad 5 fiber in serum which contains antibodies to the different virion antigenic determinants associated with Ad 5. (U.S.)

  7. Alternative affinity tools: more attractive than antibodies?

    NARCIS (Netherlands)

    Ruigrok, V.J.B.; Levisson, M.; Eppink, M.H.M.; Smidt, H.; Oost, van der J.

    2011-01-01

    Antibodies are the most successful affinity tools used today, in both fundamental and applied research (diagnostics, purification and therapeutics). Nonetheless, antibodies do have their limitations, including high production costs and low stability. Alternative affinity tools based on nucleic acids

  8. Detection of Campylobacter species using monoclonal antibodies

    Science.gov (United States)

    Young, Colin R.; Lee, Alice; Stanker, Larry H.

    1999-01-01

    A panel of species specific monoclonal antibodies were raised to Campylobacter coli, Campylobacter jejuni and Campylobacter lari. The isotypes, and cross-reactivity profiles of each monoclonal antibody against an extensive panel of micro- organisms, were determined.

  9. Progranulin antibodies in autoimmune diseases.

    Science.gov (United States)

    Thurner, Lorenz; Preuss, Klaus-Dieter; Fadle, Natalie; Regitz, Evi; Klemm, Philipp; Zaks, Marina; Kemele, Maria; Hasenfus, Andrea; Csernok, Elena; Gross, Wolfgang L; Pasquali, Jean-Louis; Martin, Thierry; Bohle, Rainer Maria; Pfreundschuh, Michael

    2013-05-01

    Systemic vasculitides constitute a heterogeneous group of diseases. Autoimmunity mediated by B lymphocytes and their humoral effector mechanisms play a major role in ANCA-associated vasculitis (AAV) as well as in non-ANCA associated primary systemic vasculitides and in the different types of autoimmune connective tissue disorders and rheumatoid arthritis. In order to detect autoantibodies in systemic vasculitides, we screened protein macroarrays of human cDNA expression libraries with sera from patients with ANCA-associated and ANCA-negative primary systemic vasculitides. This approach led to the identification of antibodies against progranulin, a 88 kDA secreted glycoprotein with strong anti-inflammatory activity in the course of disease of giant-cell arteritis/polymyalgia rheumatica (14/65), Takayasu's arteritis (4/13), classical panarteritis nodosa (4/10), Behcet's disease (2/6) and in the course of disease in granulomatosis with polyangiitis (31/75), Churg-Strauss syndrome (7/23) and in microscopic polyangiitis (7/19). In extended screenings the progranulin antibodies were also detected in other autoimmune diseases such as systemic lupus erythematosus (39/91) and rheumatoid arthritis (16/44). Progranulin antibodies were detected only in 1 of 97 healthy controls. Anti-progranulin positive patients with systemic vasculitides, systemic lupus erythematosus or rheumatoid arthritis had significant lower progranulin plasma levels, indicating a neutralizing effect. In light of the anti-inflammatory effects of progranulin, progranulin antibodies might exert pro-inflammatory effects thus contributing to the pathogenesis of the respective autoimmune diseases and might serve as a marker for disease activity. This hypothesis is supported by the fact that a positive progranulin antibody status was associated with active disease in granulomatosis with polyangiitis. PMID:23149338

  10. Monoclonal antibodies for the detection of Puccinia striiformis urediniospores

    DEFF Research Database (Denmark)

    Skottrup, Peter Durand; Frøkiær, Hanne; Hearty, Stephen;

    2007-01-01

    The fungal pathogen Pst causes yellow rust disease in wheat plants leading to crop losses. The organism spreads by releasing wind-dispersed urediniospores from infected plants. In this study a library of novel monoclonal antibodies (mAbs) was developed against Pst urediniospores. Nine m......Ab-producing cell lines were cloned and their cross-reactivities characterised against a panel of airborne fungal spores representing genera commonly found in the same environment as Pst. Two specific mAbs were used to develop a competitive ELISA (Pst mAb4) and a subtractive inhibition ELISA (Pst mAb8). Standard...

  11. Virus Strain Discrimination Using Recombinant Antibodies

    OpenAIRE

    Boonham, N.; Barker, I.

    2002-01-01

    Most routine testing for plant viruses is currently carried out using monoclonal and polyclonal antibodies. Traditional methods of antibody production however can be time consuming and require the use of expensive cell culture facilities. Recombinant antibody technology however is starting to make an impact in this area, enabling the selection of antibody fragments in a few weeks compared with the many months associated with traditional methods and requires only basic microbiological faciliti...

  12. Development of a polyclonal competitive enzyme-linked immunosorbent assay for detection of antibodies to Ehrlichia ruminantium

    OpenAIRE

    Sumption, Keith J.; Paxton, Edith; Bell-Sakyi, Lesley

    2003-01-01

    A polyclonal competitive enzyme-linked immunosorbent assay (PC-ELISA) is described for detection of antibodies to Ehrlichia (Cowdria) ruminantium by using a soluble extract of endothelial cell culture-derived E. ruminantium as the antigen and biotin-labeled polyclonal goat immunoglobulins as the competitor. For goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of 80% inhibition (80 PI), with detection of antibodies for 550 days postinfection. For cattle, diagnosti...

  13. Immunoglobulin G4: an odd antibody

    NARCIS (Netherlands)

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

    2009-01-01

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

  14. Induction of adhesion-inhibitory antibodies against placental Plasmodium falciparum parasites by using single domains of VAR2CSA

    DEFF Research Database (Denmark)

    Nielsen, Morten A; Pinto, Vera V; Resende, Mafalda;

    2009-01-01

    the molecule which induce antibodies that inhibit CSA binding of different parasite strains. In this study, we produced a large panel of VAR2CSA proteins and raised antibodies against these antigens. We show that antibodies against the DBL4 domain effectively inhibit parasite binding. As the...... between a parasite protein expressed on erythrocytes named variant surface antigen 2-chondroitin sulfate A (VAR2CSA) and CSA on syncytiotrophoblasts. VAR2CSA is a large polymorphic protein consisting of six Duffy binding-like (DBL), domains and with current constraints on recombinant protein production it...

  15. Effects of Anti-Caries Antibodies on Lactobacillus GG in Its Fermentation and Storage Periods

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To investigate how antibodies influence the fermentation of Lactobacillus GG and how Lactobacillus GG influences the biological properties of antibodies during the fermentation and storage periods. Methods Anti-caries immune colostrum powder (IP) and control colostrum powder (CP), skimmed milk powder (SP) at concentrations of 1%, 2.5%, 5% and 10% (w/v) were added to MRS and 50mM Hepes buffer system was used in the milk, the growth curves of Lactobacillus GG including viable cells, lactic acid concentatrion and pH, and also the titer of specific antibodies were determined during the fermentation and storage periods. Results In MRS, SP could improve the growth of Lactobacillus GG in all periods of fermentation, especially at the concentrations of 5% and 10%. CP at the concentrations of 1% and 2.5% had a good initial velocity at the beginning and CP (1%, 2.5%, 5%, 10%) in all the groups could reach a high viable cell concentration at the end of fermentation, which suggested that there were some growth factors for Lactobacillus GG in CP overcoming the inhibition of unspecific antibodies. IP at 1%, 2.5%, 5% and 10% could inhibit the growth of Lactobacillus GG in all the fermentation periods, the critical concentration point was between 2.5%-5%, and there was a competition between growth factors and the inhibition of specific antibodies. In pasteurized milk, the influence of Hepes could help the fermentation start quickly and reach the log phase earlier than in the control group; however, when combined with 5% IP, the growth of Lactobacillus GG was strongly inhibited during all the fermentation periods. The fermentation of Lactobacillus GG had no significant effect on the titer change of anti-caries antibodies during the fermentation and storage periods. Conclusion SP and CP is beneficial to the growth of Lactobacillus GG in MRS, whereas there is a competition between growth factors and the inhibition of specific antibodies to the growth of Lactobacillus GG

  16. Experimental radioimmunotherapy of a xenografted human glioma using 131I-labeled monoclonal antibody to epidermal growth factor receptor

    International Nuclear Information System (INIS)

    131I-labeled F (ab')2 fragments of murine monoclonal antibodies (MAb) 425 specific to the epidermal growth factor receptor expressed on human gliomas were used in experimental human malignant glioma immunotherapy. Two injections of 150 μCi 131I-labeled 425 F(ab')2 achieved growth inhibition of U-87MG human malignant glioma xenografts in nude mice. This radiolabeled specific MAb F(ab')2 was significantly superior to radiolabeled fragments of an anti-hepatitis virus control MAb A5C3 in influencing tumor growth. However, similar treatment of established human malignant glioma xenografts did not inhibit progressive tumor growth significantly. No clear tumor inhibition was produced by unlabeled MAb 425F(ab')2. These studies suggest that 131I-labeled MAbs have a significant antitumor effect where unmodified antibody is ineffective. Multiple doses of antibody may achieve an increase in labeled MAb concentration in tumors. (author)

  17. Preparation and Characterization of Olaquindox Polyclonal Antibody

    Institute of Scientific and Technical Information of China (English)

    CHE,Huilian; SHI Baoxia; CHEN,Jinlan; ZHU,Xuejia; HE,Jiguo

    2009-01-01

    2-[N-(2-Hydroxyethyl)-carbamoyl]-3-methyl-oxoquinoxaline-l,4-oxides (OLA) was first mono-esterificated by succinic acid anhydride, and was then turned into a derivative with carboxyl. The synthetic product was purified by recrystallization with a yield of 52.47%. Its chemical structure was determined by NMR, IR and MS spectra. The determined structure was used to synthese OLA hapten, which had the molecular structural characteristics of OLA. The OLA hapten and bovine serum albumin (BSA) were conjugated using the activated ester method, while the hapten and ovalbumin (OVA) were coupled by the mixed anhydride method. The UV scanning and infrared spectrum results showed that the hapten and the carrier protein were successfully coupled to BSA and OVA, with the combined ratios of 3.8 : 1 and 5 : 1, respectively. OLA-BSA was used as the immunogen to immunize four New Zealand white rabbits, and the high titer anti-serum produced relatively. The titers were 1 " 6400, 1 : 1600, 1 : 12800 and 1 : 6400, respectively, determined by indirect ELISA OLA-OVA as the coating antigen. The intermediate inhibition concentration (IC50) of OLA in the indirect ELISA test was 743.3 ng/mL. The lowest detection limit (IC20) was 5.71 ng/mL. High-purity OLA polyclonal antibody has been obtained by saturated ammonium sulfate and ion-exchange chromatography.

  18. Monoclonal Antibodies for Systemic Lupus Erythematosus (SLE

    Directory of Open Access Journals (Sweden)

    Gabriella Moroni

    2010-01-01

    Full Text Available A number of monoclonal antibodies (mAb are now under investigation in clinical trials to assess their potential role in Systemic Lupus Erythematosus (SLE. The most frequently used mAb is rituximab, which is directed against CD20, a membrane protein expressed on B lymphocytes. Uncontrolled trials reported an improvement of SLE activity in non-renal patients and other studies even reported an improvement of severe lupus nephritis unresponsive to conventional treatments. However two randomized trials failed to show the superiority of rituximab over conventional treatment in non renal SLE and in lupus nephritis. Preliminary trials reported promising results with epratuzumab, a humanized mAb directed against CD22, and with belimumab, a human mAb that specifically recognizes and inhibits the biological activity of BLyS a cytokine of the tumornecrosis-factor (TNF ligand superfamily. Other clinical trials with mAb directed against TNF-alpha, interleukin-10 (Il-10, Il-6, CD154, CD40 ligand, IL-18 or complement component C5 are under way. At present, however, in spite of good results reported by some studies, no firm conclusion on the risk-benefit profile of these mAbs in patients with SLE can be drawn from the available studies.

  19. Generation of Potent Anti-Vascular Endothelial Growth Factor Neutralizing Antibodies from Mouse Phage Display Library for Cancer Therapy

    Science.gov (United States)

    Lai, Yan-Da; Wu, Yen-Yu; Tsai, Yi-Jiue; Tsai, Yi-San; Lin, Yu-Ying; Lai, Szu-Liang; Huang, Chao-Yang; Lok, Ying-Yung; Hu, Chih-Yung; Lai, Jiann-Shiun

    2016-01-01

    Vascular endothelial growth factor (VEGF) is an important stimulator for angiogenesis in solid tumors. Blocking VEGF activity is an effective therapeutic strategy to inhibit tumor growth and metastasis. Avastin, a humanized monoclonal antibody recognizes VEGF, has been approved by the US Food and Drug Administration. To generate potential VEGF-recognizing antibodies with better tumor regression ability than that of Avastin, we have designed a systematic antibody selection plan. From mice immunized with recombinant human VEGF, we generated three phage display libraries, scFv-M13KO7, Fab-M13KO7, and scFv-Hyperphage, in single-chain Fv (scFv) or Fab format, displayed using either M13KO7 helper phage or Hyperphage. Solid-phase and solution-phase selection strategies were then applied to each library, generating six panning combinations. A total of sixty-four antibodies recognizing VEGF were obtained. Based on the results of epitope mapping, binding affinity, and biological functions in tumor inhibition, eight antibodies were chosen to examine their abilities in tumor regression in a mouse xenograft model using human COLO 205 cancer cells. Three of them showed improvement in the inhibition of tumor growth (328%–347% tumor growth ratio (% of Day 0 tumor volume) on Day 21 vs. 435% with Avastin). This finding suggests a potential use of these three antibodies for VEGF-targeted therapy. PMID:26861297

  20. Generation of Potent Anti-Vascular Endothelial Growth Factor Neutralizing Antibodies from Mouse Phage Display Library for Cancer Therapy.

    Science.gov (United States)

    Lai, Yan-Da; Wu, Yen-Yu; Tsai, Yi-Jiue; Tsai, Yi-San; Lin, Yu-Ying; Lai, Szu-Liang; Huang, Chao-Yang; Lok, Ying-Yung; Hu, Chih-Yung; Lai, Jiann-Shiun

    2016-01-01

    Vascular endothelial growth factor (VEGF) is an important stimulator for angiogenesis in solid tumors. Blocking VEGF activity is an effective therapeutic strategy to inhibit tumor growth and metastasis. Avastin, a humanized monoclonal antibody recognizes VEGF, has been approved by the US Food and Drug Administration. To generate potential VEGF-recognizing antibodies with better tumor regression ability than that of Avastin, we have designed a systematic antibody selection plan. From mice immunized with recombinant human VEGF, we generated three phage display libraries, scFv-M13KO7, Fab-M13KO7, and scFv-Hyperphage, in single-chain Fv (scFv) or Fab format, displayed using either M13KO7 helper phage or Hyperphage. Solid-phase and solution-phase selection strategies were then applied to each library, generating six panning combinations. A total of sixty-four antibodies recognizing VEGF were obtained. Based on the results of epitope mapping, binding affinity, and biological functions in tumor inhibition, eight antibodies were chosen to examine their abilities in tumor regression in a mouse xenograft model using human COLO 205 cancer cells. Three of them showed improvement in the inhibition of tumor growth (328%-347% tumor growth ratio (% of Day 0 tumor volume) on Day 21 vs. 435% with Avastin). This finding suggests a potential use of these three antibodies for VEGF-targeted therapy. PMID:26861297

  1. Generation of Potent Anti-Vascular Endothelial Growth Factor Neutralizing Antibodies from Mouse Phage Display Library for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Yan-Da Lai

    2016-02-01

    Full Text Available Vascular endothelial growth factor (VEGF is an important stimulator for angiogenesis in solid tumors. Blocking VEGF activity is an effective therapeutic strategy to inhibit tumor growth and metastasis. Avastin, a humanized monoclonal antibody recognizes VEGF, has been approved by the US Food and Drug Administration. To generate potential VEGF-recognizing antibodies with better tumor regression ability than that of Avastin, we have designed a systematic antibody selection plan. From mice immunized with recombinant human VEGF, we generated three phage display libraries, scFv-M13KO7, Fab-M13KO7, and scFv-Hyperphage, in single-chain Fv (scFv or Fab format, displayed using either M13KO7 helper phage or Hyperphage. Solid-phase and solution-phase selection strategies were then applied to each library, generating six panning combinations. A total of sixty-four antibodies recognizing VEGF were obtained. Based on the results of epitope mapping, binding affinity, and biological functions in tumor inhibition, eight antibodies were chosen to examine their abilities in tumor regression in a mouse xenograft model using human COLO 205 cancer cells. Three of them showed improvement in the inhibition of tumor growth (328%–347% tumor growth ratio (% of Day 0 tumor volume on Day 21 vs. 435% with Avastin. This finding suggests a potential use of these three antibodies for VEGF-targeted therapy.

  2. Corrosion inhibiting organic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  3. Production, isolation, and characterization of rabbit anti-idiotypic antibodies directed against human antithyrotrophin receptor antibodies.

    OpenAIRE

    Baker, J. R.; Lukes, Y G; Burman, K. D.

    1984-01-01

    Previous studies have shown that anti-idiotypic antibodies can be developed in vivo through animal immunization with idiotype, and that these antibodies can be isolated from other anti-immunoglobulin antibodies by affinity purification. These techniques have relied on large amounts of idiotype, which were produced either by hyperimmunization or by monoclonal antibodies, to serve as the affinity adsorbent. In the present study, we produced anti-idiotypic antibodies to human anti-thyroid-stimul...

  4. Avian influenza in ovo vaccination with replication defective recombinant adenovirus in chickens: vaccine potency, antibody persistence, and maternal antibody transfer.

    Science.gov (United States)

    Mesonero, Alexander; Suarez, David L; van Santen, Edzard; Tang, De-Chu C; Toro, Haroldo

    2011-06-01

    Protective immunity against avian influenza (AI) can be elicited in chickens in a single-dose regimen by in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad)-vector encoding the AI virus (AIV) hemagglutinin (HA). We evaluated vaccine potency, antibody persistence, transfer of maternal antibodies (MtAb), and interference between MtAb and active in ovo or mucosal immunization with RCA-free recombinant Ad expressing a codon-optimized AIV H5 HA gene from A/turkey/WI/68 (AdTW68.H5(ck)). Vaccine coverage and intrapotency test repeatability were based on anti-H5 hemagglutination inhibition (HI) antibody levels detected in in ovo vaccinated chickens. Even though egg inoculation of each replicate was performed by individuals with varying expertise and with different vaccine batches, the average vaccine coverage of three replicates was 85%. The intrapotency test repeatability, which considers both positive as well as negative values, varied between 0.69 and 0.71, indicating effective vaccination. Highly pathogenic (HP) AIV challenge of chicken groups vaccinated with increasing vaccine doses showed 90% protection in chickens receiving > or = 10(8) ifu (infectious units)/bird. The protective dose 50% (PD50) was determined to be 10(6.5) ifu. Even vaccinated chickens that did not develop detectable antibody levels were effectively protected against HP AIV challenge. This result is consistent with previous findings ofAd-vector eliciting T lymphocyte responses. Higher vaccine doses significantly reduced viral shedding as determined by AIV RNA concentration in oropharyngeal swabs. Assessment of antibody persistence showed that antibody levels of in ovo immunized chickens continued to increase until 12 wk and started to decline after 18 wk of age. Intramuscular (IM) booster vaccination with the same vaccine at 16 wk of age significantly increased the antibody responses in breeder hens, and these responses were maintained at high

  5. Generation of a haptoglobin-hemoglobin complex-specific Fab antibody blocking the binding of the complex to CD163

    DEFF Research Database (Denmark)

    Horn, Ivo R; Nielsen, Marianne Jensby; Madsen, Mette; Jacobsen, Christian; Graversen, Jonas Heilskov; Moestrup, Søren K

    2003-01-01

    During intravascular hemolysis hemoglobin (Hb) binds to haptoglobin (Hp) leading to endocytosis of the complex by the macrophage receptor, CD163. In the present study, we used a phage-display Fab antibody strategy to explore if the complex formation between Hp and Hb leads to exposure of antigenic...... measured for non-complexed Hp or Hb. The Fab antibody completely inhibited the binding of 125I-labeled Hp-Hb complexes to CD163 and blocked their uptake in CD163-transfected cells. In conclusion, we have raised a receptor-blocking antibody specifically recognizing the Hp-Hb complex. In addition to provide...

  6. The effect of anti-human plasminogen monoclonal antibodies on Glu-plasminogen activation by plasminogen activators

    Directory of Open Access Journals (Sweden)

    M. Akrami

    2006-07-01

    the A1D12 F(ab region to Glu-plasminogen increases the catalytic efficiency of plasminogen activation by plasminogen activators. Therefore, it may be useful to apply clinically A1D12 for the therapy of thromboembolic events such as myocardial infarction by humanizing the F(ab fragment of the A1D12 antibody. Inhibition pattern of antibody MC2B8 obey the mixed type of enzyme inhibition by binding the antibody probably at, or near, the cleavage site of Glu-plasminogen.

  7. Solid phase double-antibody radioimmunoassay procedure

    International Nuclear Information System (INIS)

    The present invention is concerned with the radioimmunoassay (RIA) procedure for assaying body fluid content of an antigenic substance which may either be an antigen itself or a hapten capable of being converted, such as by means of reaction with a protein, to an antigenic material. The present invention is concerned with a novel and improved modification of a double-antibody RIA technique in which there is a first antibody that is specific to the antigenic substance suspected to be present in a body fluid from which the assay is intended. The second antibody, however, is not specific to the antigenic substance or analyte, but is an antibody against the first antibody

  8. The role of antibodies in myasthenia gravis.

    Science.gov (United States)

    De Baets, M; Stassen, M H W

    2002-10-15

    Myasthenia gravis is an autoimmune disease associated with antibodies directed to the postsynaptic acetylcholine receptor. These antibodies reduce the number of receptors. Autoantibodies against AChR and other muscle antigens can be used for the diagnosis of myasthenia gravis and related disorders. The origin and the role of these antibodies in the disease are discussed. Experimental autoimmune myasthenia gravis, an experimental model closely mimicking the disease, has provided answers to many questions about the role of antibodies, complement macrophages and AChR anchor proteins. Genetically modified anti-AChR antibodies may also be used in the future to treat myasthenia. PMID:12220686

  9. Production of Monoclonal Antibody against Human Nestin.

    Science.gov (United States)

    Hadavi, Reza; Zarnani, Amir Hassan; Ahmadvand, Negah; Mahmoudi, Ahmad Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Sadeghi, Mohammad-Reza; Soltanghoraee, Haleh; Akhondi, Mohammad Mehdi; Tarahomi, Majid; Jeddi-Tehrani, Mahmood; Rabbani, Hodjattallah

    2010-04-01

    We have employed a peptide-based antibody generation protocol for producing antibody against human nestin. Using a 12-mer synthetic peptide from repetitive region of human nestin protein devoid of any N- or O-glyco-sylation sequences, we generated a mouse monoclonal antibody capable of recognizing human, mouse, bovine, and rat nestin. A wide variety of nestin proteins ranging from 140-250 kDa was detected by this antibody. This antibody is highly specific and functional in applications such as ELISA, flow cytometry, immunocytochemistry, and Western blot assays. PMID:23407796

  10. Production of Monoclonal Antibody against Human Nestin

    OpenAIRE

    Hadavi, Reza; Zarnani, Amir Hassan; Ahmadvand, Negah; Mahmoudi, Ahmad Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Sadeghi, Mohammad-Reza; Soltanghoraee, Haleh; Akhondi, Mohammad mehdi; Tarahomi, Majid; Jeddi-Tehrani, Mahmood; Rabbani, Hodjattallah

    2010-01-01

    We have employed a peptide-based antibody generation protocol for producing antibody against human nestin. Using a 12-mer synthetic peptide from repetitive region of human nestin protein devoid of any N- or O-glyco-sylation sequences, we generated a mouse monoclonal antibody capable of recognizing human, mouse, bovine, and rat nestin. A wide variety of nestin proteins ranging from 140–250 kDa was detected by this antibody. This antibody is highly specific and functional in applications such a...

  11. Redesigning a Monospecific Anti-FGFR3 Antibody to Add Selectivity for FGFR2 and Expand Antitumor Activity.

    Science.gov (United States)

    Yin, Yiyuan; Djakovic, Stevan; Marsters, Scot; Tien, Janet; Peng, Jing; Tremayne, Jarrod; Lee, Genee; Neve, Richard M; Wu, Yan; Merchant, Mark; Ashkenazi, Avi; Carter, Paul J

    2015-10-01

    FGF receptors (FGFR) are attractive candidate targets for cancer therapy because they are dysregulated in several human malignancies. FGFR2 and FGFR3 can be inhibited potentially without disrupting adult tissue homeostasis. In contrast, blocking the closely related FGFR1 and FGFR4, which regulate specific metabolic functions, carries a greater safety risk. An anti-FGFR3 antibody was redesigned here to create function-blocking antibodies that bind with dual specificity to FGFR3 and FGFR2 but spare FGFR1 and FGFR4. R3Mab, a previously developed monospecific anti-FGFR3 antibody, was modified via structure-guided phage display and acquired additional binding to FGFR2. The initial variant was trispecific, binding tightly to FGFR3 and FGFR2 and moderately to FGFR4, while sparing FGFR1. The X-ray crystallographic structure indicated that the antibody variant was bound to a similar epitope on FGFR2 as R3Mab on FGFR3. The antibody was further engineered to decrease FGFR4-binding affinity while retaining affinity for FGFR3 and FGFR2. The resulting dual-specific antibodies blocked FGF binding to FGFR3 and FGFR2 and inhibited downstream signaling. Moreover, they displayed efficacy in mice against human tumor xenografts overexpressing FGFR3 or FGFR2. Thus, a monospecific antibody can be exquisitely tailored to confer or remove binding to closely related targets to expand and refine therapeutic potential. PMID:26269606

  12. Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

    International Nuclear Information System (INIS)

    Research highlights: → The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. → Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. → The universal antibodies cross-neutralize different influenza A subtypes. → The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

  13. Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Anwar M. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Microbiology, Faculty of Medicine, King Abdulaziz University, Jeddah (Saudi Arabia); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada); Van Domselaar, Gary [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Li, Changgui; Wang, Junzhi [National Institute for the Control of Pharmaceutical and Biological Products, Beijing (China); She, Yi-Min; Cyr, Terry D. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Sui, Jianhua [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); He, Runtao [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Marasco, Wayne A. [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); Li, Xuguang, E-mail: Sean.Li@hc-sc.gc.ca [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada)

    2010-12-10

    Research highlights: {yields} The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. {yields} Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. {yields} The universal antibodies cross-neutralize different influenza A subtypes. {yields} The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

  14. 125I-labeled protein A as a general tracer in immunoassay: suitability of goat and sheep antibodies

    International Nuclear Information System (INIS)

    The immunoassay method in which 125I-labeled staphylococcal Protein A ([125I]PA) serves as a general tracer has been extended to include goat and sheep IgG antibodies. Goat and sheep IgG normally do not react significantly with PA. However, once IgG antibody is bound to immobilized antigen or hapten, binding of [125I]PA is enhanced markedly. Binding efficiencies of [125I]PA to immune complexed goat anti-human IgM, human IgE, methotrexate and sheep anti-IgE were determined and compared quantitatively to rabbit IgG with the corresponding specificity. Immunoassays were developed based on the inhibition of [125I]PA binding as a measure of antibody inhibition by fluid-phase homologous ligand. Goat antibody to the monovalent hapten methotrexate behaved anomalously: for each concentration of IgG tested, there was an optimal amount of methotrexate beads that gave maximum binding of [125I]PA. In the other immune systems, for each antibody concentration maximum binding of tracer was a function only of the amount of immobilized anitgen added. In contrast to the results obtained with solid-phase antigen, solutions containing antibody and amounts of antigen ranging from large antigen excess to antibody excess failed to react significantly with PA or [125I]PA. (Auth.)

  15. Neutralizing antibodies derived from the B cells of 1918 influenza pandemic survivors.

    Science.gov (United States)

    Yu, Xiaocong; Tsibane, Tshidi; McGraw, Patricia A; House, Frances S; Keefer, Christopher J; Hicar, Mark D; Tumpey, Terrence M; Pappas, Claudia; Perrone, Lucy A; Martinez, Osvaldo; Stevens, James; Wilson, Ian A; Aguilar, Patricia V; Altschuler, Eric L; Basler, Christopher F; Crowe, James E

    2008-09-25

    Investigation of the human antibody response to influenza virus infection has been largely limited to serology, with relatively little analysis at the molecular level. The 1918 H1N1 influenza virus pandemic was the most severe of the modern era. Recent work has recovered the gene sequences of this unusual strain, so that the 1918 pandemic virus could be reconstituted to display its unique virulence phenotypes. However, little is known about adaptive immunity to this virus. We took advantage of the 1918 virus sequencing and the resultant production of recombinant 1918 haemagglutinin (HA) protein antigen to characterize at the clonal level neutralizing antibodies induced by natural exposure of survivors to the 1918 pandemic virus. Here we show that of the 32 individuals tested that were born in or before 1915, each showed seroreactivity with the 1918 virus, nearly 90 years after the pandemic. Seven of the eight donor samples tested had circulating B cells that secreted antibodies that bound the 1918 HA. We isolated B cells from subjects and generated five monoclonal antibodies that showed potent neutralizing activity against 1918 virus from three separate donors. These antibodies also cross-reacted with the genetically similar HA of a 1930 swine H1N1 influenza strain, but did not cross-react with HAs of more contemporary human influenza viruses. The antibody genes had an unusually high degree of somatic mutation. The antibodies bound to the 1918 HA protein with high affinity, had exceptional virus-neutralizing potency and protected mice from lethal infection. Isolation of viruses that escaped inhibition suggested that the antibodies recognize classical antigenic sites on the HA surface. Thus, these studies demonstrate that survivors of the 1918 influenza pandemic possess highly functional, virus-neutralizing antibodies to this uniquely virulent virus, and that humans can sustain circulating B memory cells to viruses for many decades after exposure-well into the tenth

  16. C-C chemokine receptor-7 mediated endocytosis of antibody cargoes into intact cells

    Directory of Open Access Journals (Sweden)

    FrançoisMarceau

    2013-09-01

    Full Text Available The C-C chemokine receptor-7 (CCR7 is a G protein coupled receptor that has a role in leukocyte homing, but that is also expressed in aggressive tumor cells. Preclinical research supports that CCR7 is a valid target in oncology. In view of the increasing availability of therapeutic monoclonal antibodies that carry cytotoxic cargoes, we studied the feasibility of forcing intact cells to internalize known monoclonal antibodies by exploiting the cycle of endocytosis and recycling triggered by the CCR7 agonist CCL19. Firstly, an anti-CCR7 antibody (CD197; clone 150503 labeled surface recombinant CCR7 expressed in intact HEK 293a cells and the fluorescent antibody was internalized following CCL19 treatment. Secondly, a recombinant myc-tagged CCL19 construction was exploited along the anti-myc monoclonal antibody 4A6. The myc-tagged ligand was produced as a conditioned medium of transfected HEK 293a cells that contained the equivalent of 430 ng/ml of immunoreactive CCL19 (average value, ELISA determination. CCL19-myc, but not authentic CCL19, carried the fluorophore-labeled antibody 4A6 into other recipient cells that expressed recombinant CCR7 (microscopy, cytofluorometry. The immune complexes were apparent in endosomal structures, colocalized well with the small GTPase Rab5 and progressed toward Rab7-positive endosomes. A dominant negative form of Rab5 (GDP-locked inhibited this endocytosis. Further, endosomes in CCL19-myc- or CCL19-stimulated cells were positive for β-arrestin2, but rarely for β-arrestin1. Following treatment with CCL19-myc and the 4A6 antibody, the melanoma cell line A375 that expresses endogenous CCR7 was specifically stained using a secondary peroxidase-conjugated antibody. Agonist-stimulated CCR7 can transport antibody-based cargoes, with possible therapeutic applications in oncology.

  17. 9 CFR 113.452 - Erysipelothrix Rhusiopathiae Antibody.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Erysipelothrix Rhusiopathiae Antibody... REQUIREMENTS Antibody Products § 113.452 Erysipelothrix Rhusiopathiae Antibody. Erysipelothrix Rhusiopathiae Antibody is a specific antibody product containing antibodies directed against one or more somatic...

  18. Monoclonal Antibody Therapies against Anthrax

    OpenAIRE

    Zhaochun Chen; Mahtab Moayeri; Robert Purcell

    2011-01-01

    Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. It not only causes natural infection in humans but also poses a great threat as an emerging bioterror agent. The lethality of anthrax is primarily attributed to the two major virulence factors: toxins and capsule. An extensive effort has been made to generate therapeutically useful monoclonal antibodies to each of the virulence components: protective antigen (PA), lethal factor (LF) and ede...

  19. Antibody Peptide Based Antifungal Immunotherapy

    OpenAIRE

    Magliani, Walter; Conti, Stefania; Giovati, Laura; Zanello, Pier Paolo; Sperindè, Martina; Ciociola, Tecla; Polonelli, Luciano

    2012-01-01

    Fungal infections still represent relevant human illnesses worldwide and some are accompanied by unacceptably high mortality rates. The limited current availability of effective and safe antifungal agents makes the development of new drugs and approaches of antifungal vaccination/immunotherapy every day more needed. Among them, small antibody(Ab)-derived peptides are arousing great expectations as new potential antifungal agents. In this topic, the search path from the study of the yeast kill...

  20. Epigenetics of the antibody response

    OpenAIRE

    Li, Guideng; Zan, Hong; Xu, Zhenming; Casali, Paolo

    2013-01-01

    Epigenetic marks, such as DNA methylation, histone posttranslational modifications and microRNAs, are induced in B cells by the same stimuli that drive the antibody response. They play major roles in regulating somatic hypermutation (SHM), class switch DNA recombination (CSR) and differentiation to plasma cells or long-lived memory B cells. Histone modifications target the CSR and, possibly, SHM machinery to the immunoglobulin locus; they together with DNA methylation and microRNAs modulate t...

  1. Lupus anticoagulants and antiphospholipid antibodies

    Science.gov (United States)

    ... tests may include: Activated Partial thromboplastin time (aPTT) Russell viper venom time Thromboplastin inhibition test Tests for ... Textbook of Rheumatology . 9th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 82. Holbrook A, Schulman S, Witt DM, ...

  2. Pharmacological selection of antibodies for immunoscintigraphy

    International Nuclear Information System (INIS)

    The recent development of hybridoma technology has resulted in the production of monoclonal antibodies that recognize a variety of tumor antigens. Many antibodies have been developed and some of them are used with different success in clinical practice. A list of criteria is proposed for the selection of antibodies suitable for imaging studies illustrated with the example of two monoclonal antibodies anti-CEA and 19.9 used in colorectal carcinoma imaging. Monoclonal antibodies obtained today are not truly tumor-specific, they are tumor-associated; this suggests that some cross-reactions with normal tissues exist. For immunoscintigraphical use it is important to select antibodies which procedure high tumor cell staining with limited reactivity against normal tissues. Antibodies can be separated into F(ab')2 and Fab fragments which diffuse more easily into the tumor with a rapid clearance from the circulation giving higher tumor to normal tissues ratio at an early time. Antibodies with both high affinity and avidity towards tumor cell receptors produce better imaging results. Antibodies can be labelled directly with iodine or technetium and with indium using chelating agents. In vivo kinetics of radiolabelled antibodies are very different considering the nuclide and the labelling method used. Pharmacokinetics on nude mice grated with human tumors are very useful for selecting the most appropriate nuclide antibody fragment and the most efficient labelling technique for a given application. (author)

  3. Isolation of active site and antibody-binding fragments of human erythrocyte transglutaminase

    International Nuclear Information System (INIS)

    Catalytically active human erythrocyte transglutaminase (TGase) was purified using an immunoaffinity column prepared from a monoclonal antibody to guinea pig liver TGase. The enzyme activity was completely inhibited by incorporation of iodo[14C]acetamide to the level of 1 mole per 1 mole of TGase. The 14C-labeled TGase was digested with cyanogen bromide, subjected to HPLC, and four pure peptides were isolated with molecular weights ranging from 3-22 KDa. Only one of the peptides was radiolabeled and characterized as an active site peptide of 10 KDa. Another peptide of 18 KDa was identified as a monoclonal antibody-binding domain of TGase. Although the active site and the antibody-binding domain were present on different cyanogen bromide fragments, the mouse anti-TGase inhibited 100% of TGase activity. The results suggest that the antibody-binding site is not located on the enzyme active site sequence, but that the three dimensional space configuration of the antigen-antibody complex hinders substrate binding to the active site. The radiolabeled active site cysteine residue was not found in the N-terminal 21 amino acids of the 10 KDa peptide. Additional fragments of the active site peptide are currently being analyzed

  4. Immunoradiometric assay for quantification of serum antibodies to dental plaque antigen in immunized dogs

    International Nuclear Information System (INIS)

    An immunoradiometric assay (IRMA) was used for quantifying dog serum antibodies to antigens from dental plaque collected from full-grown dogs. The antigens were adsorbed onto the inner surface of plastic tubes and then incubated with dog-anti-plaque serum, 125I-labelled anti-dog plasma-immunoglobulin was used for quantification of the specific antibodies. Four 10 months old Beagle dogs in excellent gingival health were immunized for 10 weeks with ultrasonicated dog dental plaque. The antibody levels in antisera sampled 6, 8, 10 and 11 weeks after the first antigen injection were 2 to 5 times as high as those recorded before the immunizing period. The variability of the assay as judged from the difference between duplicate samples was found to be 18 percent+-4 (p<0.01) of the mean value and the variability between the same serum ran on different test occasions 13 percent+-7 (p<0.01). The specificity of the antigen-antibody reaction in the immuno assay was tested by inhibition experiments. Preincubation of the antisera with dental plaque antigen significantly inhibited the antigen-antibody reaction in the IRMA, while bovine serum albumin did not. (author)

  5. Polyclonal antibody against conserved sequences of mce1A protein blocks MTB infection in macrophages.

    Science.gov (United States)

    Sivagnanam, Sasikala; Namasivayam, Nalini; Chellam, Rajamanickam

    2012-03-01

    The pathogenesis of Mycobacterium tuberculosis is largely due to its ability to enter and survive within human macrophages. It is suggested that a specific protein namely mammalian cell entry protein is involved in the pathogenesis and the specific gene for this protein mce1A has been identified in several pathogenic organisms such as Rickettsia, Shigella, Escherichia coli, Helicobacter, Streptomyces, Klebsiella, Vibrio, Neisseria, Rhodococcus, Nocardioides, Saccharopolyspora erthyrae, and Pseudomonas. Analysis of mce1 operons in the above mentioned organisms through bioinformatics tools has revealed the presence of unique sequences (conserved regions) suggesting that these sequences may be involved in the process of infection. Presently, the mce1A full-length (1,365 bp) region from Mycobacterium bovis and its conserved regions (303 bp) were cloned in to an expression vector and the purified expressed proteins of molecular weight ~47 and ~11 kDa, respectively, were injected to rabbits to raise the polyclonal antibodies. The purified polyclonal antibodies were checked for their ability to inhibit the Mycobacterium infection in cultured human macrophages. In macrophage invasion assay, when antibody added at high concentration, decrease in viable counts was observed in all cell cultures within the first 5 days after infection, where the intracellular bacterial CFU obtained from the infected MTB increased by the 3rd day at low concentration of antibody. The macrophage invasion assay has indicated that the purified antibodies of mce1A conserved region can inhibit the infection of Mycobacterium. PMID:22159737

  6. Application of Monoclonal Antibodies in Veterinary Parasitology

    Directory of Open Access Journals (Sweden)

    Gupta A.

    2011-08-01

    Full Text Available The discovery of hybridoma technology by Kohler and Milstein in 1975, heralded a new era in antibody research. Mouse hybridomas were the first reliable source of monoclonal antibodies. The generation of monoclonal antibodies from species other than rats and mice, has developed slowly over the last 30 years. The advent of antibody engineering and realization of the advantages of non murine antibodies has increased their relevance recently. However, in the area of veterinary parasitology, monoclonal antibodies are just beginning to fulfill the promises inherent in their great specificity for recognizing and selectively binding to antigens. This review describes the recent advances in the application of monoclonal antibodies for immunodiagnosis / prophylaxis and immunotherapy of parasitic diseases. [Vet. World 2011; 4(4.000: 183-188

  7. Development of antibody against sulfamethazine

    International Nuclear Information System (INIS)

    Sulfamethazine (SMT) is widely used to treat bacterial and protozoan infections in food animals. So its residue has been detected in various food products, and in Europe, the tolerance level for sulfonamides in meat and milk is 100 ng/g. To ensure that residues in animal food products do not exceed this limit, a simple, sensitive, and rapid method to determinate their residues in animal tissues is needed. In this paper the development of polyclonal or monoclonal antibodies against sulfamethazine (SMT) and a simplified method to identify residual sulfamethazine by radio immunoassay (RIA) is presented. Polyclonal antibodies (PcAbs) against sulfamethazine (SMT) were obtained by immunizing rabbits with SMT-conjugated bovine serum albumin (BSA). The association constants (Ka) of the PcAbs were higher than 108 and the cross-reactivities with Sulfadiazine(SD), Sulfaquinoxaline(SQX) which were structurally related compounds were lower than 0.05%(RIA). Simultaneous, six strains of hybridoma cell were prepared which can secrete monoclonal antibodies (McAbs) against SMT . The Ka of the McAbs against SMT were higher than 107 and the cross-reactivities with SD, SQX were lower than 0.1%(RIA). (authors)

  8. ANTITUMOR EFFECTS OF MONOCLONAL ANTIBODY FAB′ FRAGMENT CONTAINING IMMUNOCONJUGATES

    Institute of Scientific and Technical Information of China (English)

    刘小云; 甄永苏

    2002-01-01

    Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol (DTT),while Fab′ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β mercaptoethanol.The conjugation between Fab′ fragment and pingyangmycin (PYM),an antitumor antibiotic,was mediated by dextran T 40.Immunoreactivity of Fab′ PYM conjugates with cancer cells was determined by ELISA,and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay.Antitumor effects of the Fab′ PYM conjugates were evaluated by subcutaneously transplanted tumors in mice. Results.The molecular weight of Fab′ fragment was approximately 53 kD,while the average molecular weight of Fab′ PYM conjugate was 170 kD.The Fab′ PYM conjugates showed immunoreactivity with antigen relevant cancer cells and selective cytotoxicity against target cells.Administered intravenously,Fab′ PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb. Conclusion.Fab′ PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth,suggesting its therapeutic potential in cancer treatment.

  9. Clinical application of antibody monoclonal humanized anti-EGFrnimotuzumab labeled

    International Nuclear Information System (INIS)

    Most malignant tumors are of epithelial origin. These are characterized by overexpression of the receptor of epidermal growth factor (EGFR), which the neoplastic cells escape the regulatory mechanisms are allowed, so its high concentration of membrane is generally associated with a poor prognosis . By binding an antibody specifically to this receptor, preventing binding of EGF latter and activation mechanism tyrosine kinase inhibiting cell mitosis and apoptosis causing tumor cell. For this reason, the EGFr has been considered as an attractive target for anti-tumor therapy. The humanized monoclonal antibody anti-EGFr nimotuzumab was developed by the Center of Molecular Immunology (Havana, Cuba). Numerous clinical trials have been developed in the Department of Clinical Research Center Isotopes (Cuba), in which it has been applied this antibody, both labeled with 99mTc for immuno gammagraphic detection of tumors, as labeled with 188Re for radioimmunotherapy of gliomas high degree of malignancy. The aim of this paper is to show the experience of the Department of Clinical Research of CENTIS in various clinical trials with marking for both immuno gammagraphics detection of tumors, such as for radioimmunotherapy nimotuzumab. (author)

  10. Advances in monoclonal antibody application in myocarditis

    Institute of Scientific and Technical Information of China (English)

    Li-na HAN; Shuang HE; Yu-tang WANG; Li-ming YANG; Si-yu LIU; Ting ZHANG

    2013-01-01

    Monoclonal antibodies have become a part of daily preparation technologies in many laboratories.Attempts have been made to apply monoclonal antibodies to open a new train of thought for clinical treatments of autoimmune diseases,inflammatory diseases,cancer,and other immune-associated diseases.This paper is a prospective review to anticipate that monoclonal antibody application in the treatment of myocarditis,an inflammatory disease of the heart,could be a novel approach in the future.In order to better understand the current state of the art in monoclonal antibody techniques and advance applications in myocarditis,we,through a significant amount of literature research both domestic and abroad,developed a systematic elaboration of monoclonal antibodies,pathogenesis of myocarditis,and application of monoclonal antibodies in myocarditis.This paper presents review of the literature of some therapeutic aspects of monoclonal antibodies in myocarditis and dilated cardiomyopathy to demonstrate the advance of monoclonal antibody application in myocarditis and a strong anticipation that monoclonal antibody application may supply an effective therapeutic approach to relieve the severity of myocarditis in the future.Under conventional therapy,myocarditis is typically associated with congestive heart failure as a progressive outcome,indicating the need for alternative therapeutic strategies to improve long-term results.Reviewing some therapeutic aspects of monoclonal antibodies in myocarditis,we recently found that monoclonal antibodies with high purity and strong specificity can accurately act on target and achieve definite progress in the treatment of viral myocarditis in rat model and may meet the need above.However,several issues remain.The technology on howto make a higher homologous and weak immunogenic humanized or human source antibody and the treatment mechanism of monoclonal antibodies may provide solutions for these open issues.If we are to further stimulate

  11. Antibody responses after vaccination against equine influenza in the Republic of Korea in 2013

    OpenAIRE

    Kim, Eun-Ju; KIM, Bo-Hye; YANG, Sunjoo; Choi, Eun-jin; SHIN, Ye-Jin; SONG, Jae-Young; Shin, Yeun-Kyung

    2015-01-01

    In this study, antibody responses after equine influenza vaccination were investigated among 1,098 horses in Korea using the hemagglutination inhibition (HI) assay. The equine influenza viruses, A/equine/South Africa/4/03 (H3N8) and A/equine/Wildeshausen/1/08 (H3N8), were used as antigens in the HI assay. The mean seropositive rates were 91.7% (geometric mean antibody levels (GMT), 56.8) and 93.6% (GMT, 105.2) for A/equine/South Africa/4/03 and A/equine/Wildeshausen/1/08, respectively. Yearli...

  12. Application of the Farr assay to the analysis of antibodies specific for UV irradiated DNA

    International Nuclear Information System (INIS)

    In order to determine the optimum conditions for reactivity in the ammonium sulphate precipitation (Farr) assay the authors have studied the DNA binding properties of two antibodies raised against ultraviolet single stranded DNA (UVssDNA) complexed with methylated bovine serum albumin. In general the buffer composition, pH, temperature, and ionic strength conditions described for binding to undamaged DNA were found to be appropriate for binding to UV-irradiated DNA. However, some differences in detail were noted which indicate the necessity for checking the physical conditions of binding of individual antibodies. Mouse monoclonal antibody and rabbit polyclonal antisera bound to UVssDNA very rapidly, even when DNA and ammonium sulphate were added simultaneously, whereas this procedure prevented binding of rabbit antisera to UV-irradiated double stranded DNA. Incubation at 450 C for 30 min inhibited binding by mouse antibody, and incubation at 370 C for 60 min caused reversible dissociation of the DNA-antibody complex. The optimised Farr assay was used to define the antigen specificities of the antibodies. (Auth.)

  13. Iron as the Key Modulator of Hepcidin Expression in Erythroid Antibody-Mediated Hypoplasia

    Directory of Open Access Journals (Sweden)

    J. C. Fernandes

    2014-01-01

    Full Text Available Erythroid hypoplasia (EH is a rare complication associated with recombinant human erythropoietin (rHuEPO therapies, due to development of anti-rHuEPO antibodies; however, the underlying mechanisms remain poorly clarified. Our aim was to manage a rat model of antibody-mediated EH induced by rHuEPO and study the impact on iron metabolism and erythropoiesis. Wistar rats treated during 9 weeks with a high rHuEPO dose (200 IU developed EH, as shown by anemia, reduced erythroblasts, reticulocytopenia, and plasmatic anti-rHuEPO antibodies. Serum iron was increased and associated with mRNA overexpression of hepatic hepcidin and other iron regulatory mediators and downregulation of matriptase-2; overexpression of divalent metal transporter 1 and ferroportin was observed in duodenum and liver. Decreased EPO expression was observed in kidney and liver, while EPO receptor was overexpressed in liver. Endogenous EPO levels were normal, suggesting that anti-rHuEPO antibodies blunted EPO function. Our results suggest that anti-rHuEPO antibodies inhibit erythropoiesis causing anemia. This leads to a serum iron increase, which seems to stimulate hepcidin expression despite no evidence of inflammation, thus suggesting iron as the key modulator of hepcidin synthesis. These findings might contribute to improving new therapeutic strategies against rHuEPO resistance and/or development of antibody-mediated EH in patients under rHuEPO therapy.

  14. PREVALENCE OF ANTIBODIES AGAINST INFLUENZA VIRUS IN NON-VACCINATED EQUINES FROM THE BRAZILIAN PANTANAL

    Directory of Open Access Journals (Sweden)

    Lucas Gaíva E Silva

    2014-12-01

    Full Text Available The prevalence of antibodies against Equine Influenza Virus (EIV was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1% with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5% and negativity in equine infectious anemia virus (EIAV (61.7% were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.

  15. Specific antibodies modulate the interactions of adenovirus type 5 with dendritic cells

    International Nuclear Information System (INIS)

    Adenovirus type 5 (Ad5) is able to induce an efficient CD8+ T lymphocyte (CTL) response against a transgene product, a property thought to be linked to its ability to transduce dendritic cells (DCs). Little, however, is known about the capacity of Ad5 to interact with DCs in the presence of specific antibodies, although most people test positive for antibodies directed against Ad5. In the present study, we found that in the presence of Ad5 antibodies, a large fraction of Ad5 binds very efficiently to DCs, and that this binding is FcγRII/FcγRIII dependent. Nevertheless, in the presence of high levels of antibodies against the whole virion, Ad5 entry was inhibited. Increased binding led to increased entry in DCs in the presence of fiber-specific antibodies or in the presence of low amounts of a whole antiserum raised against whole virions, showing that the relative concentration of antibodies directed against fiber and penton base plays a major role in entry efficacy. Nevertheless, mice previously immunized with virions or purified fiber developed a lower transgene-specific CD8+ T cell response than naive mice, although their serum appeared to increase virus entry into DCs in vitro

  16. Radioimmunoassay of IgM and IgG antitetanus toxoid antibody

    International Nuclear Information System (INIS)

    A radioimmunoassay was developed to quantitate antitetanus toxoid antibody in whole plasma which can detect 0.75 ng IgG antibody (0.75 μg/ml plasma) and 1.60 ng IgM antibody (0.40 μg/ml plasma). The IgG antibody was measured by direct binding to a tetanus toxoid-Sepharose immunoadsorbent. The IgM antibody was measured by inhibition of binding by soluble tetanus toxoid because of the relatively high and erratic non-specific reaction between IgM and the immunoadsorbent. The immunoglobulin standards were [131I]IgG or [131I]IgM coupled to Sepharose, respectively, and the amount of antibody activity in the 125I-labeled antiglobulin reagents could be calculated from the amount bound to the immunoadsorbent and the specific activity of the appropriate immunoglobulin standard. The assay is sensitive, reproducible and suitable for use with large numbers of samples: it should find wide applicability in both clinical and experimental settings. (Auth.)

  17. Prevalence of antibodies against influenza virus in non-vaccinated equines from the Brazilian Pantanal.

    Science.gov (United States)

    Gaíva e Silva, Lucas; Borges, Alice Mamede Costa Marques; Villalobos, Eliana Monteforte Cassaro; Lara, Maria do Carmo Custodio Souza Hunold; Cunha, Elenice Maria Siquetin; de Oliveira, Anderson Castro Soares; Braga, Isis Assis; Aguiar, Daniel Moura

    2014-01-01

    The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region. PMID:25351542

  18. Preserved antiviral adaptive immunity following polyclonal antibody immunotherapy for severe murine influenza infection

    Science.gov (United States)

    Stevens, Natalie E.; Hatjopolous, Antoinette; Fraser, Cara K.; Alsharifi, Mohammed; Diener, Kerrilyn R.; Hayball, John D.

    2016-01-01

    Passive immunotherapy may have particular benefits for the treatment of severe influenza infection in at-risk populations, however little is known of the impact of passive immunotherapy on the formation of memory responses to the virus. Ideally, passive immunotherapy should attenuate the severity of infection while still allowing the formation of adaptive responses to confer protection from future exposure. In this study, we sought to determine if administration of influenza-specific ovine polyclonal antibodies could inhibit adaptive immune responses in a murine model of lethal influenza infection. Ovine polyclonal antibodies generated against recombinant PR8 (H1N1) hemagglutinin exhibited potent prophylactic capacity and reduced lethality in an established influenza infection, particularly when administered intranasally. Surviving mice were also protected against reinfection and generated normal antibody and cytotoxic T lymphocyte responses to the virus. The longevity of ovine polyclonal antibodies was explored with a half-life of over two weeks following a single antibody administration. These findings support the development of an ovine passive polyclonal antibody therapy for treatment of severe influenza infection which does not affect the formation of subsequent acquired immunity to the virus. PMID:27380890

  19. Preserved antiviral adaptive immunity following polyclonal antibody immunotherapy for severe murine influenza infection.

    Science.gov (United States)

    Stevens, Natalie E; Hatjopolous, Antoinette; Fraser, Cara K; Alsharifi, Mohammed; Diener, Kerrilyn R; Hayball, John D

    2016-01-01

    Passive immunotherapy may have particular benefits for the treatment of severe influenza infection in at-risk populations, however little is known of the impact of passive immunotherapy on the formation of memory responses to the virus. Ideally, passive immunotherapy should attenuate the severity of infection while still allowing the formation of adaptive responses to confer protection from future exposure. In this study, we sought to determine if administration of influenza-specific ovine polyclonal antibodies could inhibit adaptive immune responses in a murine model of lethal influenza infection. Ovine polyclonal antibodies generated against recombinant PR8 (H1N1) hemagglutinin exhibited potent prophylactic capacity and reduced lethality in an established influenza infection, particularly when administered intranasally. Surviving mice were also protected against reinfection and generated normal antibody and cytotoxic T lymphocyte responses to the virus. The longevity of ovine polyclonal antibodies was explored with a half-life of over two weeks following a single antibody administration. These findings support the development of an ovine passive polyclonal antibody therapy for treatment of severe influenza infection which does not affect the formation of subsequent acquired immunity to the virus. PMID:27380890

  20. A nylon ball solid-phase radioimmunoassay for specific antibodies in human sera. Application to measurement of IgG antibodies to pollen allergens

    International Nuclear Information System (INIS)

    The principle of the radioallergosorbent test (RAST) has been used to measure IgG antibodies to timothy grass pollen allergens in sera from desensitized allergic subjects. 125I-labeled goat anti-human IgG was used as detector protein. Non-specific binding was eliminated by use of a non-porous nylon ball an antigen carrier and by use of a special buffer with high ionic strength and pH, containing 1% bovine gamma globulin and 5% normal rabbit serum as 'balance proteins'. At dilution 1:80 non-specific binding was only 0.28% and the binding ratio for a high-titer serum was about 10. By inhibition experiments the assay was demonstrated to be specific for IgG antibodies to timothy grass pollen. The results obtained with this assay correlated statistically significantly with those found with a double-antibody method. Serum dilution curves were parallel, indicating that the assay is in allergen excess. The within-assay coefficient of variation ranged from 3.9 to 7.6%; the between-assay coefficient of variation from 8.4 to 19.5%. The assay is very simple to perform, requiring no centrifugation. The allergen-coated balls are stable for at least 3 months. The assay should be applicable to measurement of IgG antibodies and IgG subclass antibodies to any protein antigen of interest. (Auth.)

  1. The inhibition of anti-DNA binding to DNA by nucleic acid binding polymers.

    Directory of Open Access Journals (Sweden)

    Nancy A Stearns

    Full Text Available Antibodies to DNA (anti-DNA are the serological hallmark of systemic lupus erythematosus (SLE and can mediate disease pathogenesis by the formation of immune complexes. Since blocking immune complex formation can attenuate disease manifestations, the effects of nucleic acid binding polymers (NABPs on anti-DNA binding in vitro were investigated. The compounds tested included polyamidoamine dendrimer, 1,4-diaminobutane core, generation 3.0 (PAMAM-G3, hexadimethrine bromide, and a β-cylodextrin-containing polycation. As shown with plasma from patients with SLE, NABPs can inhibit anti-DNA antibody binding in ELISA assays. The inhibition was specific since the NABPs did not affect binding to tetanus toxoid or the Sm protein, another lupus autoantigen. Furthermore, the polymers could displace antibody from preformed complexes. Together, these results indicate that NABPs can inhibit the formation of immune complexes and may represent a new approach to treatment.

  2. Phage displayed peptides and anti-idiotype antibodies recognised by a monoclonal antibody directed against a diagnostic antigen of Mycoplasma capricolum subsp. capripneumoniae.

    Science.gov (United States)

    Bengurić, D R; Dungu, B; Thiaucourt, F; du Plessis, D H

    2001-07-26

    A monoclonal antibody (Mab 4.52) raised against Mycoplasma capricolum subsp. capripneumoniae (Mccp) cell lysate was used as a template to obtain substitute antigens recognised by its paratope. Two approaches were investigated: a 17-mer random peptide library displayed on the surface of a filamentous phage was screened by panning on the immobilised Mab 4.52 and anti-idiotype antibodies were generated by immunising a chicken with the F(ab')(2) fragments of the antibody. Analysis of the peptide sequences displayed by the isolated phages identified two peptides. Both contained two cysteine residues and had identical or similar amino acids in positions 5 (P), 8 (I/L) and 13 (L). The fusion phages were also recognised by Mab 4.52 in enzyme-linked immunosorbent assay (ELISA) and binding was shown by surface plasmon resonance. One of the peptides was a markedly better inhibitor (67%) of the binding of Mab 4.52 to its original antigen than the other (20%) at 1mg/ml. After absorption, to remove isotypic and allotypic reactivities, the anti-idiotype IgY was specifically recognised by Mab 4.52 in ELISA and was able to inhibit its binding to the original antigen, whereas anti-idiotype antibodies raised against a bluetongue virus-specific antibody had no effect. In spite of unequivocal binding of the anti-idiotype antibodies and the fusion phages to the paratope of Mab 4.52, goat antisera appeared not to react with either of the surrogate antigens. In contrast, the test sera bound to the original antigen suggesting that Mab 4.52 does not recognise exactly the same antigenic site as antibodies in the goat antisera. PMID:11376960

  3. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

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

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies are...... powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors such as......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  4. 高表达HER2的自发转移性乳腺癌小鼠模型的建立与应用%Establishment and application of a spontaneously metastasizing breast cancer model with HER2 overexpression in mice

    Institute of Scientific and Technical Information of China (English)

    刘卉卉; 胡思怡; 沈国栋; 张志辉; 费保珍; 刘兢; 胡世莲

    2014-01-01

    Aim To establish a mouse breast cancer model stab-ly expressing HER2. Methods 4T1-Luc mouse breast cancer cell line was transfected with the full-length human HER2 gene and selected with G418. The HER2 expression in 4T1-Luc stable cells was detected by fluorescence-activated cell sorting ( FACS) and Western blot. 4T1-Luc/HER2 cells were implanted into the mammary fat pads of BALB/c or nude mice. After tumor stabili-zation, mice were randomly assigned into 4 groups for treatment with PBS control, chA21, Trastuzumab, or chA21 plus Trastu-zumab. Tumor volumes were measured and tumor growth inhibi-tion ratios were calculated twice a week. At the end of experi-ment, tumor metastasis in mice was detected by bioluminescence imaging technology. Results Several 4T1-Luc/HER2 stable cell clones were obtained after G418 selection. FACS and West-ern blot analysis showed that all clones expressed HER2 protein at high levels. These 4T1-Luc/HER2 clones showed good tumor-igenicity in mice with steady tumor growth after one week of cell implantation. After 2-3 weeks, metastatic tumor cells were seen in the lung, cheek and groin areas. In BALB/c mice, the tumor growth inhibition ratio was 43. 3% in chA21 plus Trastuzumab group (P<0. 05 vs PBS control), which was higher than chA21 group (11. 1%) or Trastuzumab group (23%). In addition, the luminescence number and density of tumor metastases in lungs were significantly reduced in the antibody combination group. Conclusions The mouse model of spontaneously metastasizing breast cancer with HER2 overexpression is successfully estab-lished. The preliminary study suggests that anti-HER2 antibody combination of chA21 and Trastuzumab has excellent inhibitory effects on tumor growth and metastasis.%目的:建立高表达HER2的自发转移性乳腺癌小鼠移植瘤模型,用于抗HER2抗体等靶向药物的药效学活性和作用机制研究。方法将重组HER2全长基因转染含有荧光素酶基因的小鼠乳腺癌细胞系4T1-Luc

  5. Immunogenicity of an engineered internal image antibody.

    OpenAIRE

    Billetta, R; Hollingdale, M. R.; Zanetti, M

    1991-01-01

    We engineered an antibody expressing in the third complementarity-determining region of its heavy chain variable region a "foreign" epitope, the repetitive tetrapeptide Asn-Ala-Asn-Pro (NANP) of the circumsporozoite protein of Plasmodium falciparum parasite, one of the etiologic agents of malaria in humans. A monoclonal antibody to P. falciparum specific for the (NANP)n amino acid sequence bound to the engineered antibody, and a synthetic (NANP)3 peptide blocked this interaction. Immunization...

  6. A general approach to antibody thermostabilization

    OpenAIRE

    McConnell, Audrey D; Xue ZHANG; Macomber, John L.; Chau, Betty; Sheffer, Joseph C; Rahmanian, Sorena; Hare, Eric; Spasojevic, Vladimir; Horlick, Robert A.; King, David J; Bowers, Peter M.

    2014-01-01

    Antibody engineering to enhance thermostability may enable further application and ease of use of antibodies across a number of different areas. A modified human IgG framework has been developed through a combination of engineering approaches, which can be used to stabilize antibodies of diverse specificity. This is achieved through a combination of complementarity-determining region (CDR)-grafting onto the stable framework, mammalian cell display and in vitro somatic hypermutation (SHM). Thi...

  7. Antibody-Mediated Lung Transplant Rejection

    OpenAIRE

    Hachem, Ramsey

    2012-01-01

    Antibody-mediated rejection after lung transplantation remains enigmatic. However, emerging evidence over the past several years suggests that humoral immunity plays an important role in allograft rejection. Indeed, the development of donor-specific antibodies after transplantation has been identified as an independent risk factor for acute cellular rejection and bronchiolitis obliterans syndrome. Furthermore, cases of acute antibody-mediated rejection resulting in severe allograft dysfunctio...

  8. Imaging tumors with radiolabelled monoclonal antibodies

    International Nuclear Information System (INIS)

    Using a metallic radionuclide, either directly bound to a monoclonal antibody, or to a chelating agent (such as di-ethylenetriamine-pentaacetic acid (DTPA)) conjugated to the antibody, a tumor can be traced rapidly and with high specificity. The labelled antibody is injected into the host. In some cases, a localization of distant metastases is possible, giving an indication of tumor spreading. Detection occurs by photoscanning. (Auth.)

  9. Haptens, conjugates and antibodies for pyrimethanil fungicide

    OpenAIRE

    Mercader Badia, Josep Vicent; Abad Fuentes, Antonio; Abad Somovilla, Antonio; Agulló, Consuelo

    2012-01-01

    [EN] The invention relates to haptens, conjugates and antibodies for pyrimethanil fungicide. In addition, the invention relates to the use of pyrimethanil conjugates as assay antigens or immunogens in order to obtain antibodies of the aforementioned fungicide, and to the use of the labelled derivatives of pyrimethanil as assay antigens. The invention also relates to a pyrimethanil analysis method using the antibodies obtained, at times together with assay antigens which are conjugates or labe...

  10. Inhibition in multiclass classification

    OpenAIRE

    Huerta, Ramón; Vembu, Shankar; Amigó, José M.; Nowotny, Thomas; Elkan, Charles

    2012-01-01

    The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and ...

  11. Inhibition effects of parathyroid hormone on human medullary thyroid carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Yaqiong Ni; Qinjiang Liu; Shihong Ma; Ruihui Chen

    2014-01-01

    Objective:The purpose of the study was to investigate the ef ects of parathyroid hormone and parathyroid hor-mone receptor monoclonal antibody on in vitro growth and proliferation of human medul ary thyroid carcinoma celllines. Methods:The medul ary thyroid carcinoma cellline was cultured in vitro, with parathyroid hormone and parathyroid hormone receptor monoclonal antibody treatment intervention, the growth of the cells was observed under an inverted contrast micro-scope, the MTT assay was used to detect the cellgrowth inhibition rate. Results:Under the inverted contrast microscope, the cells changed significantly, the parathyroid hormone and parathyroid hormone receptor monoclonal antibodies can ef ectively inhibit the proliferation of medul ary thyroid cancer cells in a time and dose dependent. When parathyroid hormone concentra-tion reached a concentration of 2.0μmol/L, the parathyroid hormone receptor monoclonal antibody reached a concentration of 1.0μmol/L, the cellgrowth was most significantly inhibited (P<0.05). Conclusion:Parathyroid hormone and parathyroid hormone receptor monoclonal antibody were able to inhibit the proliferation of medul ary thyroid carcinoma cells and signifi-cantly reduce the proliferation index.

  12. Single-domain antibodies for biomedical applications.

    Science.gov (United States)

    Krah, Simon; Schröter, Christian; Zielonka, Stefan; Empting, Martin; Valldorf, Bernhard; Kolmar, Harald

    2016-02-01

    Single-domain antibodies are the smallest antigen-binding units of antibodies, consisting either only of one variable domain or one engineered constant domain that solely facilitates target binding. This class of antibody derivatives comprises naturally occurring variable domains derived from camelids and sharks as well as engineered human variable or constant antibody domains of the heavy or light chain. Because of their high affinity and specificity as well as stability, small size and benefit of multiple re-formatting opportunities, those molecules emerged as promising candidates for biomedical applications and some of these entities have already proven to be successful in clinical development. PMID:26551147

  13. Mouse monoclonal antibodies against estrogen receptor.

    Science.gov (United States)

    De Rosa, Caterina; Rossi, Valentina; Abbondanza, Ciro

    2014-01-01

    The production of monoclonal antibodies, by cloning hybridoma derived from the fusion of myeloma cells and spleen lymphocytes, has allowed to obtain great advances in many fields of biological knowledge. The use of specific antibodies to the estrogen receptor, in fact, has been an invaluable method to bring out its mechanisms of action and its effects, both genomic and extra-genomic. Here we describe, step by step, the production of monoclonal antibodies, starting from protocol for antigen preparation to the selection of antibody-secreting hybridoma. PMID:25182770

  14. Heparin-Induced Thrombocytopenia Antibody Test

    Science.gov (United States)

    ... Thrombocytopenia Platelet Factor 4 Antibody Related tests: Complete Blood Count , Platelet Count , Serotonin Release Assay, Heparin-induced Platelet Aggregation All content on Lab Tests Online has been ...

  15. Antiphospholipid Antibodies and Systemic Scleroderma

    Directory of Open Access Journals (Sweden)

    Awa Oumar Touré

    2013-03-01

    Full Text Available Objective: Antiphospholipid antibodies (APLs could be associated with an increased risk of vascular pathologies in systemic scleroderma. The aim of our study was to search for APLs in patients affected by systemic scleroderma and to evaluate their involvement in the clinical manifestations of this disease. Materials and Methods: We conducted a cross-sectional descriptive study, from January 2009 until August 2010, with patients received at the Department of Dermatology (Dakar, Senegal. Blood samples were taken at the hematology laboratory and were analyzed for the presence of APLs. Results: Forty patients were recruited. Various types of either isolated or associated APLs were found in 23 patients, i.e. 57.5% of the study population. The most frequently encountered antibody was IgG anti-β2 GPI (37.5% of the patients, followed by anticardiolipins (17.5% and lupus anticoagulants (5%. No statistically significant association of positive antiphospholipid-related tests to any of the scleroderma complications could be demonstrated. Conclusion: A high proportion of patients showing association of systemic scleroderma and APLs suggests the presence of a morbid correlation between these 2 pathologies. It would be useful to follow a cohort of patients affected by systemic scleroderma in order to monitor vascular complications following confirmation of the presence of antiphospholipid syndrome.

  16. Preliminary study on guiding therapy of subcutaneous human hetero graft in nude mice by 211-At labelled monoclonal antibody against gastric cancer

    International Nuclear Information System (INIS)

    In short time, 211At labelled monoclonal antibody 3H11 inhibited the growth of human gastric cancer grafted in nude mice effectively. The most evident inhibition was observed at the 9th day after treatment, and the tumor inhibition rates were 80%, 93%, 48% in the groups of intravenous injection, internal tumor injection (both 211At-3H11 5 μCi per animal), Na211 At (5 μCi per animal) treatment respectively. On the 20th day, when animals were killed, the tumor inhibition rates were 66%, 81%, 6%, respectively. Inhibition treated with Na211At showed obviously lower than those at the 9th day

  17. Production and assay of forskolin antibodies

    International Nuclear Information System (INIS)

    Forskolin (Fo), a cardiovascular active diterpene of plant origin, has been widely used as a research tool in regulation of the catalytic activity of adenylate cyclase (AC). A linear relationship of Fo binding to plasma membrane with activation of AC has been reported. The present abstract describes the production and assay of Fo antibodies (AB). 7-0-Hemisuccinyl-7-deacetyl Fo, coupled to either human serum albumin or goat IgG, was injected into goats to elicit AB to Fo haptan. AB to Fo in antiserum or an isolated IgG fraction was tested by two assay methods, a radioimmunoassay using 3H-Fo as a tracer and a colorimetric enzyme-linked immunosorbent assay (ELISA) using horse radish peroxidase-rabbit anti goat IgG as indicator. The titers for Fo antiserum were 4000-10,000. In the defined assay condition, approximately 20-25% of the added 3H-Fo was found to bind to AB. The bound radioactivity was displaced by Fo-HSA or Fo-goat IgG or free unlabelled Fo ranging from 0.5-50 pmol/tube, or 5-500 nM. The IC50 was approximately 8-10 pmol/tube or 80-100 nM. The binding of HRP-rabbit anti goat IgG in the ELISA was inhibited by proper Fo conjugate. The development of methods for production and assay for Fo AB may be useful in the study of mechanism of activation of AC by Fo and Fo-like compound

  18. 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 not...... 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....

  19. Stratification of Antibody-Positive Subjects by Antibody Level Reveals an Impact of Immunogenicity on Pharmacokinetics

    OpenAIRE

    Zhou, Lei; Hoofring, Sarah A.; Wu, Yu; Vu, Thuy; Ma, Peiming; Swanson, Steven J.; Chirmule, Narendra; Starcevic, Marta

    2012-01-01

    The availability of highly sensitive immunoassays enables the detection of antidrug antibody (ADA) responses of various concentrations and affinities. The analysis of the impact of antibody status on drug pharmacokinetics (PK) is confounded by the presence of low-affinity or low-concentration antibody responses within the dataset. In a phase 2 clinical trial, a large proportion of subjects (45%) developed ADA following weekly dosing with AMG 317, a fully human monoclonal antibody therapeutic....

  20. High level transient production of recombinant antibodies and antibody fusion proteins in HEK293 cells

    OpenAIRE

    Jäger, Volker; Büssow, Konrad; Wagner, Andreas; Weber, Susanne; Hust, Michael; Frenzel, André; Schirrmann, Thomas

    2013-01-01

    Background The demand of monospecific high affinity binding reagents, particularly monoclonal antibodies, has been steadily increasing over the last years. Enhanced throughput of antibody generation has been addressed by optimizing in vitro selection using phage display which moved the major bottleneck to the production and purification of recombinant antibodies in an end-user friendly format. Single chain (sc)Fv antibody fragments require additional tags for detection and are not as suitable...

  1. Antibodies to human fetal erythroid cells from a nonimmune phage antibody library

    OpenAIRE

    Huie, Michael A.; Cheung, Mei-Chi; Muench, Marcus O.; Becerril, Baltazar; Kan, Yuet W.; Marks, James D.

    2001-01-01

    The ability to isolate fetal nucleated red blood cells (NRBCs) from the maternal circulation makes possible prenatal genetic analysis without the need for diagnostic procedures that are invasive for the fetus. Such isolation requires antibodies specific to fetal NRBCs. To generate a panel of antibodies to antigens present on fetal NRBCs, a new type of nonimmune phage antibody library was generated in which multiple copies of antibody fragments are displayed on each pha...

  2. ANTIBODI MONOKLONAL STREPTOKOKUS MUTANS 1(c 67 kDa DALAM PASTA GIGI BAHAN DASAR UNTUK MENGHAMBAT PERTUMBUHAN STREPTOKOKUS MUTANS

    Directory of Open Access Journals (Sweden)

    Rini Devijanti R.

    2015-08-01

    Full Text Available Prevention of dental caries is still continuing, because the prevalency caries is high. There was many methods to prevent dental caries etc. dental education, oral hygiene, special method on tooth brushing, water fluoridation, fissure sealant and later on the passive immunization with monoclonal antibodies. The purpose of this study was to investigate about monoclonal antibodies IgA, IgG1 and IgG3 against Streptococcus mutans 1(c in basic paste for inhibiting the growth Streptococcus mutans. The monoclonal antibodies were IgA Ab, IgG1 Ab and IgG3 Ab. Formula basic paste from PT “X” contained Aqua, Sorbitol, Nipagin, Dicalcium Phosphat, Titanium Dioxid, Sodium Carboxyl Methyl Sel. Sodium Lauryl Sulfate and Sacarin. Basic paste was mixed with monoclonal antibodies IgA, IgG1 and IgG3 in room temperature (27oC then to investigate zone of inhibition from these tooth paste with Wistreich and Lechman methods. The data obtained in this study was analyzed with one way Anova and LSD. The result showed that there was a significant differences between basic paste with or without monoclonal antibodies. From the data analyzed in this study it can be concluded that monoclonal antibodies against S. mutans 1( c could be formulation with basic paste.

  3. Comparison of nephelometric and hemolytic techniques for determination of antistreptolysin O antibodies.

    Science.gov (United States)

    Pacifico, L; Mancuso, G; Properzi, E; Ravagnan, G; Pasquino, A M; Chiesa, C

    1995-04-01

    The sensitivity of a newly devised nephelometric method for determining antistreptolysin O antibodies was compared with the hemolytic inhibition assay. Three hundred-thirty single serum samples from children with and without evidence of group A streptococcal infection were analyzed by the two techniques. The nephelometric method results correlated well with those of the reference test (concordance: r = 0.88). Furthermore, 134 pairs of acute and convalescent phase sera from patients with culture-proven GAS infection and 50 pairs from children who served as control subjects were examined. The nephelometric assay was more sensitive in detecting significant ASO antibody rises than the hemolytic assay. The automated nephelometric method appears to be a much simpler and sensitive procedure for testing ASO antibodies. PMID:7726133

  4. Human Monoclonal Antibodies to Pf 155, a Major Antigen of Malaria Parasite Plasmodium falciparum

    Science.gov (United States)

    Udomsangpetch, Rachanee; Lundgren, Katarina; Berzins, Klavs; Wahlin, Birgitta; Perlmann, Hedvig; Troye-Blomberg, Marita; Carlsson, Jan; Wahlgren, Mats; Perlmann, Peter; Bjorkman, Anders

    1986-01-01

    Pf 155, a protein of the human malaria parasite Plasmodium falciparum, is strongly immunogenic in humans and is believed to be a prime candidate for the preparation of a vaccine. Human monoclonal antibodies to Pf 155 were obtained by cloning B cells that had been prepared from an immune donor and transformed with Epstein-Barr virus. When examined by indirect immunofluorescence, these antibodies stained the surface of infected erythrocytes, free merozoites, segmented schizonts, and gametocytes. They bound to a major polypeptide with a relative molecular weight of 155K and to two minor ones (135K and 120K), all having high affinity for human glycophorin. The antibodies strongly inhibited merozoite reinvasion in vitro, suggesting that they might be appropriate reagents for therapeutic administration in vivo.

  5. Antibody-Mediated Neutralization of the Exotoxin Mycolactone, the Main Virulence Factor Produced by Mycobacterium ulcerans.

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Dangy

    2016-06-01

    Full Text Available Mycolactone, the macrolide exotoxin produced by Mycobacterium ulcerans, causes extensive tissue destruction by inducing apoptosis of host cells. In this study, we aimed at the production of antibodies that could neutralize the cytotoxic activities of mycolactone.Using the B cell hybridoma technology, we generated a series of monoclonal antibodies with specificity for mycolactone from spleen cells of mice immunized with the protein conjugate of a truncated synthetic mycolactone derivative. L929 fibroblasts were used as a model system to investigate whether these antibodies can inhibit the biological effects of mycolactone. By measuring the metabolic activity of the fibroblasts, we found that anti-mycolactone mAbs can completely neutralize the cytotoxic activity of mycolactone.The toxin neutralizing capacity of anti-mycolactone mAbs supports the concept of evaluating the macrolide toxin as vaccine target.

  6. Anti-idiotypic antibodies that protect cells against the action of diphtheria toxin

    Energy Technology Data Exchange (ETDEWEB)

    Rolf, J.M.; Gaudin, H.M.; Tirrell, S.M.; MacDonald, A.B.; Eidels, L.

    1989-03-01

    An anti-idiotypic serum prepared against the combining site (idiotype) of specific anti-diphtheria toxoid antibodies was characterized with respect to its interaction with highly diphtheria toxin-sensitive Vero cells. Although the anti-idiotypic serum protected Vero cells against the cytotoxic action of diphtheria toxin, it did not prevent the binding of /sup 125/I-labeled diphtheria toxin to the cells but did inhibit the internalization and degradation of /sup 125/I-labeled toxin. This anti-idiotypic serum immunoprecipitated a cell-surface protein from radiolabeled Vero cells with an apparent Mr of approximately 15,000. These results are consistent with the hypothesis that the anti-idiotypic serum contains antibodies that carry an internal image of an internalization site on the toxin and that a cell-surface protein involved in toxin internalization possesses a complementary site recognized by both the toxin and the anti-idiotypic antibodies.

  7. Passive antibody transfer in chickens to model maternal antibody after avian influenza vaccination

    Science.gov (United States)

    Birds transfer maternal antibodies (MAb) to their offspring through the egg yolk where the antibody is absorbed and enters the circulatory system. These maternal antibodies, depending on the pathogen, can provide early protection from some diseases, but it may also interfere with the vaccination re...

  8. Immunization of Macaca fascicularis (Macaca irus) monkeys with Streptococcus mutans: specificity of antibody responses in saliva.

    Science.gov (United States)

    Emmings, F G; Evans, R T; Genco, R J

    1976-04-01

    M fascicularis monkeys were immunized subcutaneously in the vicinity of the major salivary glands and by retrograde infusion into the parotid duct, with a vaccine containing Formalin-killed S mutans strain 6715 cells and culture-fluid antigens. Indirect immunofluorescent staining was used to titrate and classify antibodies. Subcutaneous immunization induced only a serum response, whereas intraductal infusion stimulated both an IgA antibody response in the parotid fluid and a serum response. Immunized and nonimmunized control groups were orally infected with S mutans strain 6715. The establishment in dental plaque was quantitated by recovery of the infecting organism on selective media and by immunofluorescent staining of plaque smears taken from individual tooth surfaces. The establishment of S mutans strain 6715 was noticeably inhibited in immune monkeys. Immunofluorescent assays for antibody also showed that serum and parotid fluid containing serum IgA antibodies cross reacted with other d serotype and a serotype strains but not representative b and c strains. Immune and control groups were then orally infected with S mutans strain GS-5, a c serotype strain, and no inhibition in establishment was detected of the non-cross-reacting type c organism in the immune group. A latter series of booster immunizations via the intraductal route resulted in a significant decrease in parotid fluid flow. Histological investigations showed inflammatory cell infiltration and replacement of epithelium by connective tissue in the glands from immunized monkeys. A separate group of monkeys, younger than the first, was immunized with the same vaccine via the duct only. In this group, immunizations were given at shorter intervals, but the immunization response was similar to that observed in the first group. The investigations reviewed here and new experiments reported show that immunization of monkeys with S mutan strain 6715 via the parotid duct elicited a reproducible IgA antibody

  9. 21 CFR 866.3290 - Gonococcal antibody test (GAT).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gonococcal antibody test (GAT). 866.3290 Section... antibody test (GAT). (a) Identification. A gonococcal antibody test (GAT) is an in vitro device that..., indirect fluorescent antibody, or radioimmunoassay, antibodies to Neisseria gonorrhoeae in sera...

  10. High-affinity antibodies to the 1,4-dihydropyridine Ca2+-channel blockers

    International Nuclear Information System (INIS)

    Antibodies with high affinity and specificity for the 1,4-dihydropyridine Ca2+-channel blockers have been produced in rabbits by immunization with dihydropyridine-protein conjugates. Anti-dihydropyridine antibodies were found to specifically bind [3H]nitrendipine, [3H]-nimodipine, [3H]nisoldipine, and [3H]PN 200-110 (all 1,4-dihydropyridine Ca2+-channel blockers) with high affinity, while [3H]verapamil, [3H]diltiazem, and [3H]trifluoperazine were not recognized. The average dissociation constant of the [3H]nitrendipine-antibody complex was 0.06 (+/- 0.02) X 10(-9) M for an antiserum studied in detail and ranged from 0.01 to 0.24 X 10(-9) M for all antisera. Inhibition of [3H]nitrendipine binding was specific for the 1,4-dihydropyridine Ca2+-channel modifiers and the concentrations required for half-maximal inhibition ranged between 0.25 and 0.90 nM. Structurally unrelated Ca2+-channel blockers, calmodulin antagonists, inactive metabolites of nitrendipine, and UV-inactivated nisoldipine did not modify [3H]nitrendipine binding to the anti-dihydropyridine antibodies. Dihydropyridines without a bulky substituent in the 4-position of the heterocycle were able to displace [3H]nitrendipine binding, but the concentrations required for half-maximal inhibition were greater than 800 nM. In summary, anti-dihydropyridine antibodies have been shown to have high affinity and specificity for the 1,4-dihydropyridine Ca2+-channel blockers and to exhibit dihydropyridine binding properties similar to the membrane receptor for the 1,4-dihydropyridine Ca2+-channel blockers

  11. 抗神经生长因子抗体对大鼠慢性坐骨神经压迫损伤模型的脊髓胶质细胞激活的抑制作用%Anti-nerve Growth Factor Antibody Inhibits the Spinal Cord Glial Cell Activation in Rats Model of Chronic Constriction Injury

    Institute of Scientific and Technical Information of China (English)

    李棋; 麻伟青; 王慧明; 董发团; 杨云丽; 李文锋

    2012-01-01

    Objective To investigate the effects of anti-nerve growth factor antibody (anti-NGF) on the pain behavior and the spinal astrocyte activation in rats model of chronic constriction sciatic nerve injury (CCI) . Methods Chronic sciatic nerve compression injury (chronic constriction injury, CCD model was prepared by surgery in rats. The experimental rats were randomly divided into four groups: the CCI + anti- NGF group (n = 8) . rats were given daily single intraperitoneal injection of anti-NGF (10 mg/kg) at 7th day after surgery; the CCI model + saline group (n = 8) : rats were given daily single intraperitoneal injection of saline at 7th day after surgery; sham operation anti-NGF group (n =8) and sham operation saline group (n =8) . Mechanical and thermal pain behavior were observed in every another day after surgery within 15 days. 15 days after surgery, rats in each group was perfused by 4% paraformaldehyde, the expression of astrocyte cell marker GFAP in rats'L4- 5- segment spinal cord was observed by immunohistochemical staining. Results Within 3 days after surgery, the CCI model + saline group's mechanical and thermal pain threshold decreased significantly and reached its peak after 7 days. At 7th day after surgery, a single dose of anti- NGF antibody intraperitoneal injection shortly alleviated the mechanical and thermal pain threshold decrease in CCI rats, continuously injection of anti-NGF 7 days significantly improved the mechanical and thermal pain threshold of CCI rats, which was higher than rats in CCI + saline group. The spinal GFAP expression in CCI + anti-NGF group was significantly lower than the CCI + saline group at 15th day after surgery. Conclusions Inrraperitoneal injection of anti-NGF antibody can effectively reverse the pain behavior of the CCI rat model. Continuous injection of anti-NGF can significantly improve the pain behavior in the CCI rat models. In the spinal cord of rats in CCI + anti- NGF group, GFAP expression is significantly lower

  12. Rapid solid-phase radioimmunoassay for detection of equine infectious anemia viral antigen and antibodies: parameters involved in standardization

    International Nuclear Information System (INIS)

    Solid-phase radioimmunoassays (SPRIA) are described for the detection of equine infectious anemia (EIA) viral antigen and antibodies. Protein-antigen P29 currently used in the agar-gel immunodiffusion (AGID) test was used as antigen in the SPRIA. The specificity of the reaction was assessed by inhibition with the antigen. The reaction of immune serum against EIA-virus antigen adsorbed to the wells, was completely inhibited by the antigen in solution. This property was applied in an indirect competitive SPRIA for the detection of viral protein P29. The detection threshold of the SPRIA for EIA virus protein was about 5 ng and about 1 ng of antibody can be detected. The assay is rapid, specific and sensitive and allows the testing of multiple serum samples with the advantage of employing a single secondary labelled antibody. (orig.)

  13. Animal experiments in positive tumor scintigraphy based on the demonstration of clostridium rods using 131I-labelled antibodies

    International Nuclear Information System (INIS)

    Clostridial spores, applied i.v. to mice, grew out selectively to rods in transplanted tumors and could be demonstrated by 131I-labelled antibodies. An increased radioactivity was to be seen after additional application of Ig G. The decreased tumor activity compared to that of the blood depends probably on the inhibited blood flow of the tumor

  14. Allosteric Inactivation of a Trypsin-Like Serine Protease by An Antibody Binding to the 37- and 70-Loops

    DEFF Research Database (Denmark)

    Kromann-Hansen, Tobias; Lund, Ida K; Liu, Zhuo;

    2013-01-01

    for elucidating fundamental allosteric mechanisms. The monoclonal antibody mU1 has previously been shown to be able to inhibit the function of murine urokinase-type plasminogen activator in vivo. We have now mapped the epitope of mU1 to the catalytic domain's 37- and 70-loops, situated about 20 Å from...

  15. GH and IGF-I induction by passive immunization of rainbow trout Oncorhynchus mykiss Walbaum using a somatostatin 14 antibody

    Science.gov (United States)

    Inhibition of the growth axis by somatostatin was studied in juvenile rainbow trout using passive immunization with a previously isolated somatostatin antibody (antiSS-14). Upon subcutaneously injection of laying hens (Gallus domesticus) with conjugated somatostatin-14 (SS-14), the antiSS-14 was iso...

  16. Binding of a neutralizing antibody to dengue virus alters the arrangement of surface glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Lok, Shee-Mei; Kostyuchenko, Victor; Nybakken, Grant E.; Holdaway, Heather A.; Battisti, Anthony J.; Sukupolvi-Petty, Soila; Sedlak, Dagmar; Fremont, Daved H.; Chipman, Paul R.; Roehrig, John T.; Diamond, Michael S.; Kuhn, Richard J.; Rossmann, Michael G. (Purdue); (WU-MED); (CDC)

    2008-04-02

    The monoclonal antibody 1A1D-2 has been shown to strongly neutralize dengue virus serotypes 1, 2 and 3, primarily by inhibiting attachment to host cells. A crystal structure of its antigen binding fragment (Fab) complexed with domain III of the viral envelope glycoprotein, E, showed that the epitope would be partially occluded in the known structure of the mature dengue virus. Nevertheless, antibody could bind to the virus at 37 degrees C, suggesting that the virus is in dynamic motion making hidden epitopes briefly available. A cryo-electron microscope image reconstruction of the virus:Fab complex showed large changes in the organization of the E protein that exposed the epitopes on two of the three E molecules in each of the 60 icosahedral asymmetric units of the virus. The changes in the structure of the viral surface are presumably responsible for inhibiting attachment to cells.

  17. Biological activities of binding site specific monoclonal antibodies to prolactin receptors of rabbit mammary gland

    International Nuclear Information System (INIS)

    The biological activity of three monoclonal antibodies (mAbs) against the rabbit mammary prolactin (PRL) receptor (M110, A82, and A917) were investigated using explants of rabbit mammary gland. The three mAbs which were all able to inhibit the binding of 125I-ovine prolactin to its receptor had different biological activities. Two mAbs (M110 and A82) were able to prevent the stimulating effect of PRL on casein synthesis when the molar ratio between the mAb and PRL was 100. One mAb (A917) was able to mimic the action of PRL on both casein and DNA ([3H]thymidine incorporation) synthesis, whereas the other two mAbs were without any stimulatory effect. For this stimulatory effect to be observed, bivalency of the antibody was essential, since monovalent fragments, which were able to inhibit PRL binding, had no agonistic activity. The ability of the mAbs to induce a down-regulation of receptors was also studied. These studies suggest that the binding domain of the receptor might be relatively complex, since only a part of this domain recognized by the antibody with PRL-like activity was able to induce hormonal action. Alternatively, only those antibodies able to microaggregate the receptors may possess PRL-like activity

  18. Production and characterization of monoclonal antibodies against rat platelet GPIIb/IIIa

    International Nuclear Information System (INIS)

    Four murine monoclonal antibodies against rat platelets were produced by fusion of spleen cells from mice intravenously immunized with whole rat platelets. All four antibodies immunoprecipitated two major platelet membrane proteins with apparent molecular weights of 130,000 and 82,000 (nonreduced) and of 120,000 and 98,000 (reduced), which were structurally analogous to human glycoprotein (GP) IIb/IIIa, i.e. rat GPIIb/IIIa. Two of four antibodies, named P9 and P55, strongly inhibited adenosine diphosphate (ADP)-induced aggregation of washed rat platelets and caused approximately 50% inhibition of human fibrinogen binding to ADP-stimulated rat platelets, suggesting that rat GPIIb/IIIa serves as a fibrinogen receptor in ADP-induced aggregation. In contrast, two other antibodies, named P14 and P34, themselves caused aggregation of rat platelets in platelet-rich plasma (PRP) and the secretion of 14C-serotonin from 14C-serotonin-labeled PRP. These results indicate that rat GPIIb/IIIa plays an important role in platelet aggregation

  19. Serological prevalence of anti-latex IgE antibodies in unselected blood donors in Argentina.

    Science.gov (United States)

    Docena, G H; Fossati, C A

    2005-01-01

    The prevalence of specific IgE to natural rubber latex proteins in the general population remains uncertain. The purpose of this study was to determine the prevalence of sera containing specific IgE antibodies to latex proteins using immunoenzymatic methods. A population of 500 unselected adult voluntary blood donors was the source of the sera used in this study. Two different immunoenzymatic methods (EAST and CARLA) were used to analyze the presence of specific IgE antibodies. Confirmation assay was carried out by inhibition ELISA and immunoblotting. Sera from healthy nonatopic individuals were also used as control. Two hundred and twenty five sera showed higher than normal total IgE levels. Of those, three presented latex specific IgE antibodies, which could be inhibited in a dose-response manner with the natural rubber latex and glove extracts. Several latex allergens were recognized by the IgE antibodies from these positive sera. This low seroprevalence (0.66%) indicates that latex hypersensitivity is not an important problem in the general population. We believe that prevention of latex exposure is only necessary in high risk groups of patients. PMID:15864882

  20. Photonic crystal fiber based antibody detection

    DEFF Research Database (Denmark)

    Duval, A; Lhoutellier, M; Jensen, J B; Hoiby, P E; Missier, V; Pedersen, L H; Hansen, Theis Peter; Bjarklev, Anders Overgaard; Bang, Ole

    An original approach for detecting labeled antibodies based on strong penetration photonic crystal fibers is introduced. The target antibody is immobilized inside the air-holes of a photonic crystal fiber and the detection is realized by the means of evanescent-wave fluorescence spectroscopy and...