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Sample records for human recombinant monoclonal

  1. 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…

  2. A recombinant, fully human monoclonal antibody with antitumor activity constructed from phage-displayed antibody fragments

    NARCIS (Netherlands)

    Huls, GA; Heijnen, IAFM; Cuomo, ME; Koningsberger, JC; Boel, E; de Vries, ARV; Loyson, SAJ; Helfrich, W; Henegouwen, GPV; van Meijer, M; de Kruif, J; Logtenberg, T

    A single-chain Fv antibody fragment specific for the tumor-associated Ep-CAM molecule was isolated from a semisynthetic phage display library and converted into an intact, fully human IgG1 monoclonal antibody (huMab), The purified huMab had an affinity of 5 nM and effectively mediated tumor cell

  3. Characterization of a Type-Common Human Recombinant Monoclonal Antibody to Herpes Simplex Virus with High Therapeutic Potential

    Science.gov (United States)

    De Logu, Alessandro; Williamson, R. Anthony; Rozenshteyn, Roman; Ramiro-Ibañez, Fernando; Simpson, Cindy D.; Burton, Dennis R.; Paolo Sanna, Pietro

    1998-01-01

    We report the characterization of a type-common human recombinant monoclonal antibody previously isolated by antigen selection from a phage-displayed combinatorial antibody library established from a herpes simplex virus (HSV)-seropositive individual. Competition with well-characterized murine monoclonal antibodies and immunodetection of gD truncations revealed that this antibody recognizes the group Ib antigenic site of glycoprotein D, a highly conserved and protective type-common determinant. To our knowledge, this is the first human group Ib monoclonal antibody ever described. The antibody also displayed first-order neutralization kinetics and a high neutralization rate constant, was capable of completely inhibiting syncytium formation by a fusogenic strain of HSV type 1, and efficiently neutralized low-passage clinical isolates of both HSV serotypes. Taken together with our earlier observations of the in vivo antiviral activities of this human recombinant antibody in animal models of HSV infection, the present results support the high therapeutic potential of this antibody. PMID:9774565

  4. Applications of monoclonal antibodies and recombinant cytokines for the treatment of human colorectal and other carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, J.W.; Smalley, R.V.; Borden, E.C.; Martin, E.W.; Guadagni, F.; Roselli, M.; Schlom, J. (Laboratory of Tumor Immunology and Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States))

    1991-01-01

    Monoclonal antibodies (MAbs) which recognize a human tumor antigen, termed tumor-associated glycoprotein-72 (TAG-72), have successfully been used to localize primary as well as metastatic colorectal tumor lesions in patients. The localization of the anti-TAG-72 MAbs has also been exploited intraoperatively using a hand-held gamma probe. That procedure, termed radioimmunoguided surgery (RIGS), has identified occult tumors which were not detected using standard external imaging techniques. In another clinical trial, interferon-gamma (IFN-gamma) was administered intraperitoneally to patients diagnosed with either gastrointestinal or ovarian carcinoma with secondary ascites. Analysis of the tumor cells isolated from the malignant ascites revealed a substantial increase in TAG-72 expression on the surface of tumor cells isolated from seven of eight patients. The results provide evidence that the combination of an anti-carcinoma MAb with the administration of a cytokine, such as IFN-gamma, may be an effective approach for the detection and subsequent treatment, of colorectal carcinoma. 15 references.

  5. Production and characterization of monoclonal antibodies raised against recombinant human granzymes A and B and showing cross reactions with the natural proteins

    NARCIS (Netherlands)

    Kummer, J. Alain; Kamp, Angela M.; van Katwijk, Marcel; Brakenhoff, Just P.J.; Radosevic, Katarina; Radosevic, K.; van Leeuwen, Anne Marie; Borst, Jannie; Verweij, Cornelis L.; Hack, C. Erik

    1993-01-01

    The human serine proteases granzymes A and B are expressed in cytotoplasmic granules of activated cytotoxic T lymphocytes and natural killer cells. Recombinant granzyme A and granzyme B proteins were produced in bacteria, purified and then used to raise specific mouse monoclonal antibodies. Seven

  6. Epitope Mapping of Human HER2 Specific Mouse Monoclonal Antibodies Using Recombinant Extracellular Subdomains

    Science.gov (United States)

    Hosseini Ghatar, Reza; Soltantoyeh, Tahereh; Bahadori, Tannaz; Golara, Maryam; Hassannia, Hadi; Khosravi Eghbal, Roya; Khoshnoodi, Jalal; Judaki, Mohammad Ali; Golsaz-Shirazi, Forough; Jeddi-Tehrani, Mahmood; Amiri, Mohammad Mehdi; Shokri, Fazel

    2017-11-26

    Background: Human epidermal growth factor receptor 2 (HER2) is overexpressed in several human malignancies and numerous studies have indicated that it plays important roles in the development and maintenance of the malignant phenotype. Targeting of HER2 molecules with monoclonal antibodies (mAbs) is a promising therapeutic approach. However, anti-HER2 mAbs affect cancer cells differently, depending on the distinct epitopes which are the targets. Methods: Reactivity of a panel of 8 mouse anti-HER2 mAbs was investigated by ELISA and Western blotting using different subdomains of the extracellular domain (ECD) of HER2. All subdomains, including I, II, III, IV, I+II, III+IV and full HER2-ECD were constructed and expressed in CHO cells. Cross-reactivity of the mAbs with other members of the human HER family and Cynomolgus HER2 was also studied by ELISA. The mAbs were also tested by immunohistochemistry (IHC) using HER2 positive breast cancer tissues. Results: Our results demonstrated that 3 out of 8 mAbs detected conformational epitopes (1T0, 2A8 and 1B5), while 5 mAbs identified linear epitopes (1F2, 1H9, 4C7, 1H6 and 2A9). Three of the mAbs recognized subdomain I, one reacted with subdomain I+II, 2 recognized either subdomain III or IV and 2 recognized subdomain III+IV. However, none of our mAbs recognized the subdomain II alone. The mAbs displayed either inhibitory or stimulatory effects on HER2-overexpressing tumor cells and did not react with other members of the human HER family. The pattern of IHC results implied better reactivity of the mAbs recognizing linear epitopes. Conclusions: Our findings suggest that paired subdomains of HER2 are essential for mapping of mAbs recognizing conformational epitopes. Moreover, there seems to be no association between subdomain specificity and antitumor activity of our anti-HER2 mAbs. 10.22034/APJCP.2017.18.11.3103

  7. Passive immunization against dental caries and periodontal disease: development of recombinant and human monoclonal antibodies.

    Science.gov (United States)

    Abiko, Y

    2000-01-01

    and periodontal diseases are summarized, and the biotechnological approaches for developing recombinant and human-type antibodies are introduced. Furthermore, our own attempts to construct single-chain variable fragments (ScFv) and human-type antibodies capable of neutralizing virulence factors are discussed.

  8. Development of a multi-product leached protein A assay for bioprocess samples containing recombinant human monoclonal antibodies.

    Science.gov (United States)

    Ren, Diya; Darlucio, Maria R; Chou, Judy H

    2011-03-07

    The detection of low level of protein A leached from monoclonal antibody downstream purification process is often interfered by the presence of excess amount of product antibody. In order to prevent this interference, we developed a new multi-product leached protein A assay that used acidification to completely dissociate the IgG-ProteinA complex, followed by neutralization under selected condition to prevent re-formation of the IgG-ProteinA complex. The amount of protein A was then determined by a sandwich immunoassay using Meso Scale Discovery technology. The assay takes approximately 3h to complete for one 96-well plate of samples, and this has been successfully applied to samples containing different monoclonal antibody products examined so far. The data demonstrates that this assay is robust and efficient in determining leached protein A contamination during purification of recombinant monoclonal antibodies. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Absolute quantitation of host cell proteins in recombinant human monoclonal antibodies with an automated CZE-ESI-MS/MS system.

    Science.gov (United States)

    Zhu, Guijie; Sun, Liangliang; Linkous, Travis; Kernaghan, Dawn; McGivney, James B; Dovichi, Norman J

    2014-05-01

    We report the first use of CZE for absolute characterization of host cell proteins (HCPs) in recombinant human monoclonal antibodies. An electrokinetically pumped nanoelectrospray interface was used to couple CZE with a tandem mass spectrometer. Three isotopic-labeled peptides (LSFDKDAMVAR, VDIVENQAMDTR, and LVSDEMVVELIEK) were synthesized by direct incorporation of an isotope-labeled lysine or arginine. The heavy-labeled peptides were spiked in the HCP digests at known concentrations. After CZE-ESI-MS/MS analysis, the peaks of native and isotopic-labeled peptides were extracted with mass tolerance ≤ 5 ppm from the electropherograms, and the ratios of peak area between native and isotopic-labeled peptides pairs were calculated. Calibration curves (the ratios of peak area versus spiked peptide amount) with R(2) values of 0.999, 0.997, and 0.999 were obtained for the three HCP peptides, and the absolute amounts of the three proteins present were determined to be at the picomole level in a 20 μg sample of digested HCPs. The target proteins were present at the 7-30 ppt level in the purified HCP samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Treatment with a human recombinant monoclonal IgG antibody against oxidized LDL in atherosclerosis-prone pigs reduces cathepsin S in coronary lesions

    DEFF Research Database (Denmark)

    Poulsen, Christian Bo; Al-Mashhadi, Ahmed Ludvigsen; Von Wachenfeldt, Karin

    2016-01-01

    Background Immunization with oxidized LDL (oxLDL) reduces atherosclerosis in rodents. We tested the hypothesis that treatment with a human recombinant monoclonal antibody against oxLDL will reduce the burden or composition of atherosclerotic lesions in hypercholesterolemic minipigs. Methods...... and results Thirty-eight hypercholesterolemic minipigs with defective LDL receptors were injected with an oxLDL antibody or placebo weekly for 12 weeks. An 18F-fluorodeoxyglucose positron emission tomography (FDG PET) scan (n = 9) was performed before inclusion and after 3 months of treatment. Blood samples.......03) with no difference in CD68 or CD163 positivity. Conclusions In hypercholesterolemic minipigs, treatment with a human recombinant monoclonal antibody against oxLDL reduced cathepsin S in coronary lesions without any effect on the burden of atherosclerosis or aortic FDG-PET signal....

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

    Science.gov (United States)

    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 steady state (Vdss) of 0.3 l/kg. Pretreatment with h2E2 produced a dramatic 8.8-fold increase in the area under the plasma cocaine concentration-time curve (AUC) and in brain a concomitant decrease of 68% of cocaine’s AUC following an i.v. injection of an equimolar cocaine dose. Sequestration of cocaine in plasma by h2E2, shown via reduction of cocaine’s Vdss, indicates potential clinical efficacy. Although the binding of cocaine to h2E2 in plasma should inhibit distribution and metabolism, the elimination of cocaine remained multicompartmental and was still rapidly eliminated from plasma despite the presence of h2E2. BE was the major cocaine metabolite, and brain BE concentrations were sixfold higher than in plasma, indicating that cocaine is normally metabolized in the brain. In the presence of h2E2, brain BE concentrations were decreased and plasma BE was increased, consistent with the observed h2E2-induced changes in cocaine disposition. The inhibition of cocaine distribution to the brain confirms the humanized mAb, h2E2, as a lead candidate for development as an immunotherapy for cocaine abuse. PMID:24733787

  12. A mathematical model of a recombinant humanized anti-cocaine monoclonal antibody's effects on cocaine pharmacokinetics in mice.

    Science.gov (United States)

    Wetzel, Hanna N; Zhang, Tongli; Norman, Andrew B

    2017-09-01

    A recombinant humanized anti-cocaine monoclonal antibody (mAb), h2E2, is at an advanced stage of pre-clinical development as an immunotherapy for cocaine abuse. It is hypothesized that h2E2 binds to and sequesters cocaine in the blood. A three-compartment model of the effects of h2E2 on cocaine's distribution was constructed. The model assumes that h2E2 binds to cocaine and that the h2E2-cocaine complex does not enter the brain but distributes between the central and peripheral compartments. Free cocaine is eliminated from both the central and peripheral compartments, and h2E2 and the h2E2-cocaine complex are eliminated from the central compartment only. This model was tested against a new dataset measuring cocaine concentrations in the brain and plasma over 1h in the presence and absence of h2E2. The mAb significantly increased plasma cocaine concentrations with a concomitant significant decrease in brain concentration. Plasma concentrations declined over the 1-hour sampling period in both groups. With a set of parameters within reasonable physiological ranges, the three-compartment model was able to qualitatively and quantitatively simulate the increased plasma concentration in the presence of the antibody and the decreased peak brain concentration in the presence of antibody. Importantly, the model explained the decline in plasma concentrations over time as distribution of the cocaine-h2E2 complex into a peripheral compartment. This model will facilitate the targeting of ideal mAb PK/PD properties thus accelerating the identification of lead candidate anti-drug mAbs. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  14. Therapeutic administration of a recombinant human monoclonal antibody reduces the severity of chikungunya virus disease in rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Rebecca Broeckel

    2017-06-01

    Full Text Available Chikungunya virus (CHIKV is a mosquito-borne virus that causes a febrile syndrome in humans associated with acute and chronic debilitating joint and muscle pain. Currently no licensed vaccines or therapeutics are available to prevent or treat CHIKV infections. We recently isolated a panel of potently neutralizing human monoclonal antibodies (mAbs, one (4N12 of which exhibited prophylactic and post-exposure therapeutic activity against CHIKV in immunocompromised mice. Here, we describe the development of an engineered CHIKV mAb, designated SVIR001, that has similar antigen binding and neutralization profiles to its parent, 4N12. Because therapeutic administration of SVIR001 in immunocompetent mice significantly reduced viral load in joint tissues, we evaluated its efficacy in a rhesus macaque model of CHIKV infection. Rhesus macaques that were treated after infection with SVIR001 showed rapid elimination of viremia and less severe joint infiltration and disease compared to animals treated with SVIR002, an isotype control mAb. SVIR001 reduced viral burden at the site of infection and at distant sites and also diminished the numbers of activated innate immune cells and levels of pro-inflammatory cytokines and chemokines. SVIR001 therapy; however, did not substantively reduce the induction of CHIKV-specific B or T cell responses. Collectively, these results show promising therapeutic activity of a human anti-CHIKV mAb in rhesus macaques and provide proof-of-principle for its possible use in humans to treat active CHIKV infections.

  15. Characterization of a recombinant humanized anti-cocaine monoclonal antibody produced from multiple clones for the selection of a master cell bank candidate.

    Science.gov (United States)

    Wetzel, Hanna N; Webster, Rose P; Saeed, Fatima O; Kirley, Terence L; Ball, William J; Norman, Andrew B

    2017-06-03

    We have generated a humanized anti-cocaine monoclonal antibody (mAb), which is at an advanced stage of pre-clinical development. We report here in vitro binding affinity studies, and in vivo pharmacokinetic and efficacy studies of the recombinant mAb. The overall aim was to characterize the recombinant antibody from each of the three highest producing transfected clones and to select one to establish a master cell bank. In mAb pharmacokinetic studies, after injection with h2E2 (120 mg/kg iv) blood was collected from the tail tip of mice over 28 days. Antibody concentrations were quantified using ELISA. The h2E2 concentration as a function of time was fit using a two-compartment pharmacokinetic model. To test in vivo efficacy, mice were injected with h2E2 (120 mg/kg iv), then one hour later injected with an equimolar dose of cocaine. Blood and brain were collected 5 min after cocaine administration. Cocaine concentrations were quantified using LC/MS. The affinity of the antibody for cocaine was determined using a [3H] cocaine binding assay. All three antibodies had long elimination half-lives, 2-5 nM Kd for cocaine, and prevented cocaine's entry into the brain by sequestering it in the plasma. Pharmacokinetic and radioligand binding assays supported designation of the highest producing clone 85 as the master cell bank candidate. Overall, the recombinant h2E2 showed favorable binding properties, pharmacokinetics, and in vivo efficacy. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Selection of Ceratitis capitata (Diptera: Tephritidae) Specific Recombinant Monoclonal Phage Display Antibodies for Prey Detection Analysis

    Science.gov (United States)

    Monzó, César; Urbaneja, Alberto; Ximénez-Embún, Miguel; García-Fernández, Julia; García, José Luis; Castañera, Pedro

    2012-01-01

    Several recombinant antibodies against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), one of the most important pests in agriculture worldwide, were selected for the first time from a commercial phage display library of human scFv antibodies. The specificity and sensitivity of the selected recombinant antibodies were compared with that of a rabbit polyclonal serum raised in parallel using a wide range of arthropod species as controls. The selected recombinant monoclonal antibodies had a similar or greater specificity when compared with classical monoclonal antibodies. The selected recombinant antibodies were successfully used to detect the target antigen in the gut of predators and the scFv antibodies were sequenced and compared. These results demonstrate the potential for recombinant scFv antibodies to be used as an alternative to the classical monoclonal antibodies or even molecular probes in the post-mortem analysis studies of generalist predators. PMID:23272105

  17. Impact of cell culture on recombinant monoclonal antibody product heterogeneity.

    Science.gov (United States)

    Liu, Hongcheng; Nowak, Christine; Shao, Mei; Ponniah, Gomathinayagam; Neill, Alyssa

    2016-09-01

    Recombinant monoclonal antibodies are commonly expressed in mammalian cell culture and purified by several steps of filtration and chromatography. The resulting high purity bulk drug substance still contains product variants differing in properties such as charge and size. Posttranslational modifications and degradations occurring during cell culture are the major sources of heterogeneity in bulk drug substance of recombinant monoclonal antibodies. The focus of the current review is the impact of cell culture conditions on the types and levels of various modifications and degradations of recombinant monoclonal antibodies. Understanding the relationship between cell culture and product variants can help to make consistently safe and efficacious products. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1103-1112, 2016. © 2016 American Institute of Chemical Engineers.

  18. Recombinant humanized monoclonal antibody against CD18 (rhuMAb CD18) in traumatic hemorrhagic shock: results of a phase II clinical trial. Traumatic Shock Group.

    Science.gov (United States)

    Rhee, P; Morris, J; Durham, R; Hauser, C; Cipolle, M; Wilson, R; Luchette, F; McSwain, N; Miller, R

    2000-10-01

    Activated neutrophils have been shown to play a pivotal role in resuscitation injury after traumatic hemorrhagic shock. Blocking the adhesion of neutrophils with a recombinant humanized monoclonal antibody against CD18 (rhuMAb CD18) may reduce resuscitation injury but increase the risk of infection. This was a dose-finding phase II study to determine safety, pharmacokinetics, pharmacodynamics, and clinical outcome parameters for additional studies. This was a prospective, placebo-controlled, randomized (3:1), double-blind phase II trial enrolling 116 blunt and penetrating trauma patients from 14 trauma centers over a 9-month period. Patients with hypotension (blood pressure history of cardiopulmonary resuscitation in the trauma center. An independent Drug Safety and Monitoring Review Board periodically reviewed unblinded data for safety issues and to give approval for dose escalation. Minor and major infection rates in rhuMAb CD18 groups were comparable to placebo. There was no evidence of antibody formation against rhuMAb CD18. Linear PK was observed within the dose range studied. Duration of neutrophil binding was dose-dependent, with 2 mg/kg resulting in greater than 90% neutrophil CD18 receptor saturation for approximately 48 hours. The mortality was 6.7% (2 of 30) in the placebo group, 4.8% (1 of 21) in the 0.5-mg/kg group, 8.5% (4 of 47) in the 1-mg/kg group, and 0% (0 of 18) in the 2-mg/kg group. The study was not powered for efficacy, and none of the efficacy variables demonstrated statistical significance. Favorable trends were seen in the 2-mg/kg group as compared with placebo in median intensive care unit length of stay (5 vs. 9 days) and median time on ventilator (34 vs. 72 hours). A single 2-mg/kg dose of rhuMAb CD18 maintains greater than 90% saturation of neutrophil CD18 receptors for approximately 48 hours in patients with traumatic hemorrhagic shock undergoing resuscitation. There was no trend toward increased infection. A larger trial is needed to

  19. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Purpose: To develop processes for effective isolation and purification of recombinant human plasminogen activator (rhPA) from transgenic rabbit milk. Methods: Immunoaffinity chromatography was selected and improved by a special polyol-responsive monoclonal antibody (PR-mAb). Alteplase was used as immunogen ...

  20. Generation of monoclonal antibodies to native active human glycosyltransferases

    DEFF Research Database (Denmark)

    Vester-Christensen, Malene Bech; Bennett, Eric Paul; Clausen, Henrik

    2013-01-01

    using monoclonal antibodies therefore provides an excellent strategy to analyze the glycosylation process in cells. A major drawback has been difficulties in generating antibodies to glycosyltransferases and validating their specificities. Here we describe a simple strategy for generating...... and characterizing monoclonal antibodies to human glycosyltransferases. This strategy includes a process for recombinant production and purification of enzymes for immunization, a simple selection strategy for isolation of antibodies with optimal properties for in situ detection of enzyme expression......, and a comprehensive strategy for characterizing the fine specificity of such antibodies....

  1. [Neutralizing Monoclonal and Chimeric Antibodies to Human IFN-γ].

    Science.gov (United States)

    Larina, M V; Aliev, T K; Solopova, O N; Pozdnyakova, L P; Korobova, S V; Yakimov, S A; Sveshnikov, P G; Dolgikh, D A; Kirpichnikov, M P

    2015-01-01

    Autoiminune disorders are chronic diseases characterized by abnormal immune response directed against self-antigens that leads to tissue damage and violation of its normal functioning. Such diseases often result in disability or even death of patients. Nowadays a number of monoclonal antibodies to pro-inflammatory cytokines and their receptors are successfully used for the targeted treatment of autoimmune diseases. One of the perspective targets in autoimmune disease therapy is interferon gamma, a key cytokine in Th1 cells differentiation, activation of macrophages, and inflammation. In the present work, 5 monoclonal antibodies to human IFN-γ were obtained. For the development of potential therapeutic agent, we have performed neutralizing activity and affinity analysis of the antibodies. Based on the data obtained, the monoclonal antibody F1 was selected. This antibody has a dissociation constant 1.7 x 10(-9) M and IC90 = 8.9 ± 2.0 nM measured upon antibody inhibition of the IFN-γ-induced HLA-DR expression on the surface of U937 cells. We have constructed a bicistronic vector for the production of recombinant chimeric Fab fragment F1 chim in E. coli cells. The recombinant chimeric Fab fragment Fl chim neutralizes IFN-γ activity in vitro and has a dissociation constant 1.8 x 10(-9) M.

  2. Purification process of recombinant monoclonal antibodies with mixed mode chromatography.

    Science.gov (United States)

    Maria, Sophie; Joucla, Gilles; Garbay, Bertrand; Dieryck, Wilfrid; Lomenech, Anne-Marie; Santarelli, Xavier; Cabanne, Charlotte

    2015-05-08

    An innovative process to purify mAb from CHO cell culture supernatant was developed. This three-step process involved two mixed mode resins and an anion exchange membrane. We used a human IgG mixture to determine the optimal conditions for each purification step. Thereafter, the whole process was evaluated and improved for the purification of a recombinant mAb produced in the supernatant of CHO cells. Once optimized, yield and purity of 88% and 99.9%, respectively were comparable to those obtained in a conventional process based on a capture step using protein A. In addition, aggregates, HCPs and DNA levels in the purified fraction were below regulatory specifications. Then we used mass spectrometry to identify contaminating proteins in the antibody fraction in order to highlight the behavior of HCPs. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Reshaped Human Monoclonal Antibodies for Therapy and Passive Immunization

    Science.gov (United States)

    1991-11-01

    Monoclonal Antibodies for Therapy and Passive Immunisation by Reshaping Rodent Monoclonal Antibodies". Two mouse monoclonal antibody producing cell...could be simply extended to make human monoclonals, but this has proved not to be the case. There are difficulties in finding appropriately immunised ...human donors and suitable fusion partners for the antibody producing cells. In vitro immunisation techniques have been tried, but only low affinity 1gM

  4. Aggregation of Human Recombinant Monoclonal Antibodies Influences the Capacity of Dendritic Cells to Stimulate Adaptive T-Cell Responses In Vitro

    Science.gov (United States)

    Sordé, Laetitia; Koepke, Stephan; Gottlieb, Sascha; Krieg, Jennifer; Djidja, Marie-Claude; Baban, Aida; Spindeldreher, Sebastian; Koulov, Atanas V.; Kiessling, Andrea

    2014-01-01

    Subvisible proteinaceous particles which are present in all therapeutic protein formulations are in the focus of intense discussions between health authorities, academics and biopharmaceutical companies in the context of concerns that such particles could promote unwanted immunogenicity via anti-drug antibody formation. In order to provide further understanding of the subject, this study closely examines the specific biological effects proteinaceous particles may exert on dendritic cells (DCs) as the most efficient antigen-presenting cell population crucial for the initiation of the adaptive immune response. Two different model IgG antibodies were subjected to three different types of exaggerated physical stress to generate subvisible particles in far greater concentrations than the ones typical for the currently marketed biotherapeutical antibodies. The aggregated samples were used in in vitro biological assays in order to interrogate the early DC-driven events that initiate CD4 T-cell dependent humoral adaptive immune responses – peptide presentation capacity and co-stimulatory activity of DCs. Most importantly, antigen presentation was addressed with a unique approach called MHC-associated Peptide Proteomics (MAPPs), which allows for identifying the sequences of HLA-DR associated peptides directly from human dendritic cells. The experiments demonstrated that highly aggregated solutions of two model mAbs generated under controlled conditions can induce activation of human monocyte-derived DCs as indicated by upregulation of typical maturation markers including co-stimulatory molecules necessary for CD4 T-cell activation. Additional data suggest that highly aggregated proteins could induce in vitro T-cell responses. Intriguingly, strong aggregation-mediated changes in the pattern and quantity of antigen-derived HLA-DR associated peptides presented on DCs were observed, indicating a change in protein processing and presentation. Increasing the amounts of

  5. 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...

  6. Expression of deleted, atoxic atypical recombinant beta2 toxin in a baculovirus system and production of polyclonal and monoclonal antibodies.

    Science.gov (United States)

    Serroni, Anna; Magistrali, Chiara Francesca; Pezzotti, Giovanni; Bano, Luca; Pellegrini, Martina; Severi, Giulio; Di Pancrazio, Chiara; Luciani, Mirella; Tittarelli, Manuela; Tofani, Silvia; De Giuseppe, Antonio

    2017-05-25

    Clostridium perfringens is an important animal and human pathogen that can produce more than 16 different major and minor toxins. The beta-2 minor toxin (CPB2), comprising atypical and consensus variants, appears to be involved in both human and animal enterotoxaemia syndrome. The exact role of CPB2 in pathogenesis is poorly investigated, and its mechanism of action at the molecular level is still unknown because of the lack of specific reagents such as monoclonal antibodies against the CPB2 protein and/or the availability of a highly purified antigen. Previous studies have reported that purified wild-type or recombinant CPB2 toxin, expressed in a heterologous system, presented cytotoxic effects on human intestinal cell lines. Undoubtedly, for this reason, to date, these purified proteins have not yet been used for the production of monoclonal antibodies (MAbs). Recently, monoclonal antibodies against CPB2 were generated using peptides designed on predicted antigenic epitopes of this toxin. In this paper we report, for the first time, the expression in a baculovirus system of a deleted recombinant C-terminal 6xHis-tagged atypical CPB2 toxin (rCPB2Δ1-25-His6) lacking the 25 amino acids (aa) of the N-terminal putative signal sequence. A high level of purified recombinant rCPB2Δ1-25-His6 was obtained after purification by Ni2+ affinity chromatography. The purified product showed no in vitro and in vivo toxicity. Polyclonal antibodies and twenty hybridoma-secreting Mabs were generated using purified rCPB2Δ1-25-His6. Finally, the reactivity and specificity of the new antibodies were tested against both recombinant and wild-type CPB2 toxins. The high-throughput of purified atoxic recombinant CPB2 produced in insect cells, allowed to obtain monoclonal and polyclonal antibodies. The availability of these molecules could contribute to develop immunoenzymatic methods and/or to perform studies about the biological activity of CPB2 toxin.

  7. A rapid and scalable method for selecting recombinant mouse monoclonal antibodies

    Directory of Open Access Journals (Sweden)

    Wright Gavin J

    2010-06-01

    Full Text Available Abstract Background Monoclonal antibodies with high affinity and selectivity that work on wholemount fixed tissues are valuable reagents to the cell and developmental biologist, and yet isolating them remains a long and unpredictable process. Here we report a rapid and scalable method to select and express recombinant mouse monoclonal antibodies that are essentially equivalent to those secreted by parental IgG-isotype hybridomas. Results Increased throughput was achieved by immunizing mice with pools of antigens and cloning - from small numbers of hybridoma cells - the functionally rearranged light and heavy chains into a single expression plasmid. By immunizing with the ectodomains of zebrafish cell surface receptor proteins expressed in mammalian cells and screening for formalin-resistant epitopes, we selected antibodies that gave expected staining patterns on wholemount fixed zebrafish embryos. Conclusions This method can be used to quickly select several high quality monoclonal antibodies from a single immunized mouse and facilitates their distribution using plasmids.

  8. Arginine Modifications by Methylglyoxal: Discovery in a Recombinant Monoclonal Antibody and Contribution to Acidic Species

    OpenAIRE

    Chumsae, Chris; Gifford, Kathreen; Lian, Wei; Liu, Hongcheng; Radziejewski, Czeslaw H.; Zhou, Zhaohui Sunny

    2013-01-01

    Heterogeneity is common among protein therapeutics. For example, the so-called acidic species (charge variants) are typically observed when recombinant monoclonal antibodies (mAbs) are analyzed by weak-cation exchange chromatography (WCX). Several protein post-translational modifications have been established as contributors, but still cannot completely account for all heterogeneity. As reported herein, an unexpected modification by methylglyoxal (MGO) was identified, for the first time, in a...

  9. Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants.

    OpenAIRE

    Hehle, VK; Paul, MJ; Roberts, VA; van Dolleweerd, CJ; Ma, JK

    2015-01-01

    This study examined the degradation pattern of a murine IgG1? monoclonal antibody expressed in and extracted from transformed Nicotiana tabacum. Gel electrophoresis of leaf extracts revealed a consistent pattern of recombinant immunoglobulin bands, including intact and full-length antibody, as well as smaller antibody fragments. N-terminal sequencing revealed these smaller fragments to be proteolytic cleavage products and identified a limited number of protease-sensitive sites in the antibody...

  10. Discovery of a Chemical Modification by Citric Acid in a Recombinant Monoclonal Antibody

    Science.gov (United States)

    2015-01-01

    Recombinant therapeutic monoclonal antibodies exhibit a high degree of heterogeneity that can arise from various post-translational modifications. The formulation for a protein product is to maintain a specific pH and to minimize further modifications. Generally Recognized as Safe (GRAS), citric acid is commonly used for formulation to maintain a pH at a range between 3 and 6 and is generally considered chemically inert. However, as we reported herein, citric acid covalently modified a recombinant monoclonal antibody (IgG1) in a phosphate/citrate-buffered formulation at pH 5.2 and led to the formation of so-called “acidic species” that showed mass increases of 174 and 156 Da, respectively. Peptide mapping revealed that the modification occurred at the N-terminus of the light chain. Three additional antibodies also showed the same modification but displayed different susceptibilities of the N-termini of the light chain, heavy chain, or both. Thus, ostensibly unreactive excipients under certain conditions may increase heterogeneity and acidic species in formulated recombinant monoclonal antibodies. By analogy, other molecules (e.g., succinic acid) with two or more carboxylic acid groups and capable of forming an anhydride may exhibit similar reactivities. Altogether, our findings again reminded us that it is prudent to consider formulations as a potential source for chemical modifications and product heterogeneity. PMID:25136741

  11. Crossreactivity of boar sperm monoclonal antibodies with human ...

    African Journals Online (AJOL)

    Monoclonal antibodies against the head (H mabs) and tail (Tmabs) of boar spermatozoa were produced. Spermatozoa from boar, stallion, bull, human, ram, goat and rabbit were independently incubated with the monoclonal antibodies and later stained by immunofluorescence method. There were positive reactions of the ...

  12. Arginine modifications by methylglyoxal: discovery in a recombinant monoclonal antibody and contribution to acidic species.

    Science.gov (United States)

    Chumsae, Chris; Gifford, Kathreen; Lian, Wei; Liu, Hongcheng; Radziejewski, Czeslaw H; Zhou, Zhaohui Sunny

    2013-12-03

    Heterogeneity is common among protein therapeutics. For example, the so-called acidic species (charge variants) are typically observed when recombinant monoclonal antibodies (mAbs) are analyzed by weak-cation exchange chromatography (WCX). Several protein post-translational modifications have been established as contributors but still cannot completely account for all heterogeneity. As reported herein, an unexpected modification by methylglyoxal (MGO) was identified, for the first time, in a recombinant monoclonal antibody expressed in Chinese hamster ovary (CHO) cells. Modifications of arginine residues by methylglyoxal lead to two adducts (dihydroxyimidazolidine and hydroimidazolone) with increases of molecular weights of 72 and 54 Da, respectively. In addition, the modification by methylglyoxal causes the antibody to elute earlier in the weak cation exchange chromatogram. Consequently, the extent to which an antibody was modified at multiple sites corresponds to the degree of shift in elution time. Furthermore, cell culture parameters also affected the extent of modifications by methylglyoxal, a highly reactive metabolite that can be generated from glucose or lipids or other metabolic pathways. Our findings again highlight the impact that cell culture conditions can have on the product quality of recombinant protein pharmaceuticals.

  13. Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants.

    Science.gov (United States)

    Hehle, Verena K; Paul, Matthew J; Roberts, Victoria A; van Dolleweerd, Craig J; Ma, Julian K-C

    2016-04-01

    This study examined the degradation pattern of a murine IgG1κ monoclonal antibody expressed in and extracted from transformedNicotiana tabacum Gel electrophoresis of leaf extracts revealed a consistent pattern of recombinant immunoglobulin bands, including intact and full-length antibody, as well as smaller antibody fragments. N-terminal sequencing revealed these smaller fragments to be proteolytic cleavage products and identified a limited number of protease-sensitive sites in the antibody light and heavy chain sequences. No strictly conserved target sequence was evident, although the peptide bonds that were susceptible to proteolysis were predominantly and consistently located within or near to the interdomain or solvent-exposed regions in the antibody structure. Amino acids surrounding identified cleavage sites were mutated in an attempt to increase resistance. Different Guy's 13 antibody heavy and light chain mutant combinations were expressed transiently inN. tabacumand demonstrated intensity shifts in the fragmentation pattern, resulting in alterations to the full-length antibody-to-fragment ratio. The work strengthens the understanding of proteolytic cleavage of antibodies expressed in plants and presents a novel approach to stabilize full-length antibody by site-directed mutagenesis.-Hehle, V. K., Paul, M. J., Roberts, V. A., van Dolleweerd, C. J., Ma, J. K.-C. Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants. © The Author(s).

  14. Production and characterization of a monoclonal antibody against recombinant cathepsin L1 of Fasciola gigantica.

    Science.gov (United States)

    Anuracpreeda, Panat; Srirakam, Thippawan; Pandonlan, Sudarat; Changklungmoa, Narin; Chotwiwatthanakun, Charoonroj; Tinikul, Yotsawan; Poljaroen, Jaruwan; Meemon, Krai; Sobhon, Prasert

    2014-08-01

    Monoclonal antibodies (MoAbs) against a recombinant cathepsin L1 of Fasciola gigantica (rFgCatL1) were produced in vitro by fusion of BALB/c mice spleen cells immunized with rFgCatL1 and mouse myeloma cells. Reactivity and specificity of these MoAbs were evaluated by indirect ELISA and immunoblotting techniques. Seven MoAb clones were selected from the stable hybridoma clones, namely 1E10, 1F5, 3D11, 4B10, 4D3, 4E3 and 5E7. Clones 1E10, 1F5 and 3D11 were IgM, whereas clones 4B10, 4D3, 4E3 and 5E7 were IgG1. All MoAbs had kappa light chain isotypes. All MoAbs reacted with rCatL1 at molecular weight (MW) 30kDa and with the native CatL1 at MW 27kDa in whole body (WB) extracts of metacercariae (Met), newly excysted juveniles (NEJ), 1, 3, 5-week-old juveniles (Ju), adult WB and adult excretory-secretory (ES) fractions, but not with adult tegumental antigens (TA). All of these MoAbs showed no cross-reactions with antigens of other parasites commonly found in ruminants and human, including Paramphistomum cervi, Eurytrema pancreaticum, Gigantocotyle explanatum, Schistosoma spindale, Schistosoma mansoni, Moniezia benedeni, Avitellina centripunctata, Trichuris sp., Haemonchus placei and Setaria labiato-papillosa. Localization of CatL1 in each developmental stages of F. gigantica by immunoperoxidase technique, using these MoAbs as probes, indicated that CatL1 was present at high concentration in the caecal epithelium and caecal lumen of metacercariae, NEJ, 1, 3, 5-week-old juveniles and adult fluke. This finding indicated that CatL1 is a copiously expressed parasite protein that is released into the ES, thus CatL1 and its MoAb could be a good candidate for immunodiagnosis of fasciolosis in ruminant and human. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. The Development of a Recombinant scFv Monoclonal Antibody Targeting Canine CD20 for Use in Comparative Medicine.

    Directory of Open Access Journals (Sweden)

    Saurabh Jain

    Full Text Available Monoclonal antibodies are leading agents for therapeutic treatment of human diseases, but are limited in use by the paucity of clinically relevant models for validation. Sporadic canine tumours mimic the features of some human equivalents. Developing canine immunotherapeutics can be an approach for modeling human disease responses. Rituximab is a pioneering agent used to treat human hematological malignancies. Biologic mimics that target canine CD20 are just being developed by the biotechnology industry. Towards a comparative canine-human model system, we have developed a novel anti-CD20 monoclonal antibody (NCD1.2 that binds both human and canine CD20. NCD1.2 has a sub-nanomolar Kd as defined by an octet red binding assay. Using FACS, NCD1.2 binds to clinically derived canine cells including B-cells in peripheral blood and in different histotypes of B-cell lymphoma. Immunohistochemical staining of canine tissues indicates that the NCD1.2 binds to membrane localized cells in Diffuse Large B-cell lymphoma, Marginal Zone Lymphoma, and other canine B-cell lymphomas. We cloned the heavy and light chains of NCD1.2 from hybridomas to determine whether active scaffolds can be acquired as future biologics tools. The VH and VL genes from the hybridomas were cloned using degenerate primers and packaged as single chains (scFv into a phage-display library. Surprisingly, we identified two scFv (scFv-3 and scFv-7 isolated from the hybridoma with bioactivity towards CD20. The two scFv had identical VH genes but different VL genes and identical CDR3s, indicating that at least two light chain mRNAs are encoded by NCD1.2 hybridoma cells. Both scFv-3 and scFv-7 were cloned into mammalian vectors for secretion in CHO cells and the antibodies were bioactive towards recombinant CD20 protein or peptide. The scFv-3 and scFv-7 were cloned into an ADEPT-CPG2 bioconjugate vector where bioactivity was retained when expressed in bacterial systems. These data identify a

  16. Analysis of human chorionic gonadotropin-monoclonal antibody ...

    Indian Academy of Sciences (India)

    However we observed that in a high affinity antigen-antibody system [human chorionic gonadotropin-monoclonal antibody (hCG-mAb)] dissociation is insignificant and the sensogram data cannot be used to measure the equilibrium and kinetic parameters. At low concentrations of mAb the complete sensogram could be ...

  17. Domain-Specific Monoclonal Antibodies Against Human Rev-erbβ.

    Science.gov (United States)

    Chen, Fang; Li, Yanqing; Zhao, Junli; Mao, Qinwen; Xia, Haibin

    2017-07-01

    The nuclear receptor Rev-erbβ is a potent transcriptional factor whose functional study has been limited by the lack of suitable antibodies against it. To better understand Rev-erbβ's biological roles, we generated five hybridoma cell lines secreting antibodies against human Rev-erbβ in mice immunized with the purified, prokaryotically expressed recombinant Rev-erbβ-6His fusion protein. Using Western blotting and immunofluorescence analyses, all the five monoclonal antibodies (MAbs) showed strong immunoreactivity to both prokaryotically and eukaryotically expressed recombinant Rev-erbβ. An immunoprecipitation study showed that all five monoclonal antibodies against Rev-erbβ were able to pull down the recombinant Rev-erbβ-Flag protein, but only one of the MAbs against Rev-erbβ, 37H8, could pull down the endogenous Rev-erbβ protein. Furthermore, domain specificity of these MAbs was characterized. Due to the high similarities between Rev-erbα and Rev-erbβ in the C and E domains, those C and E domain-specific anti-Rev-erbβ antibodies can react with human Rev-erbα as well. The MAbs produced in the study will provide a valuable tool for investigating the function of Rev-erbβ.

  18. Comparison of immunoglobulin E measurements on IMMULITE and ImmunoCAP in samples consisting of allergen-specific mouse-human chimeric monoclonal antibodies towards allergen extracts and four recombinant allergens

    DEFF Research Database (Denmark)

    Szecsi, Pal B; Stender, Steen

    2013-01-01

    Specific immunoglobulin E (IgE) antibody in vitro tests are performed on enzyme immunoassay systems. Poor agreement among systems has been reported and comparisons have been made exclusively with allergen extracts - not with recombinant allergens. Here we compare the ImmunoCAP and the IMMULITE...

  19. Production and characterization of a monoclonal antibody against recombinant saposin-like protein 2 of Fasciola gigantica.

    Science.gov (United States)

    Kueakhai, Pornanan; Changklungmoa, Narin; Chaithirayanon, Kulathida; Songkoomkrong, Sineenart; Riengrojpitak, Suda; Sobhon, Prasert

    2013-02-01

    A monoclonal antibody (MoAb) against recombinant Fasciola gigantica saposin-like protein 2 (rFgSAP-2) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with rFgSAP-2. This MoAb is an IgG1, κ light chain isotype. By immunoblotting and indirect ELISA, the MoAb reacted specifically with rFgSAP-2, the natural FgSAP-2 at 10kDa in whole body (WB) and excretory-secretory (ES) fractions of F. gigantica. It did not cross react with antigens in WB fractions from other parasites, including Opisthorchis viverrini, Schistosoma mansoni which are human parasites, Haemonchus placei, Setaria labiato-papillosa, Eurytrema pancreaticum, Cotylophoron cotylophorum, Fischoederius cobboldi, Gigantocotyle explanatum, Gastrothylax crumenifer, and Paramphistomum cervi which are ruminant parasites. By immunohistochemistry, the FgSAP-2 protein was localized only in the cytoplasm of caecal epithelial cells of 4-week-old juvenile and adult stages, but not in metacercariae, newly excysted juvenile (NEJ), 2- and 3-week-old juveniles. This finding indicated that FgSAP-2 is an abundantly expressed parasite protein that is released into the ES, hence SAP-2 and its MoAb may be used for immunodiagnosis of ruminant and human fasciolosis. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Adsorption and recovery issues of recombinant monoclonal antibodies in reversed-phase liquid chromatography.

    Science.gov (United States)

    Fekete, Szabolcs; Beck, Alain; Wagner, Elsa; Vuignier, Karine; Guillarme, Davy

    2015-01-01

    The poor recovery of large biomolecules is a well-known issue in reversed-phase liquid chromatography. Several papers have reported this problem, but the reasons behind this behavior are not yet fully understood. In the present study, state-of-the-art reversed-phase wide-pore stationary phases were used to evaluate the adsorption of therapeutic monoclonal antibodies. These biomolecules possess molar mass of approximately 150,000 g/mol and isoelectric points between 6.6 and 9.3. Two types of stationary phases were tested, the Phenomenex Aeris Widepore (silica based), with 3.6 μm superficially porous particles, and the Waters Acquity BEH300 (ethylene-bridged hybrid), with 1.7 μm fully porous particles. A systematic investigation was carried out using 11 immunoglobulin G1, G2, and G4 antibodies, namely, panitumumab, natalizumab, cetuximab, bevacizumab, trastuzumab, rituximab, palivizumab, belimumab, adalimumab, denosumab, and ofatumumab. All are approved by the Food and Drug Administration and the European Medicines Agency in various therapeutic indications and are considered as reference antibodies. Several test proteins, such as human serum albumin, transferrin, apoferritin, ovalbumin, and others, possessing a molar mass between 42,000 and 443,000 g/mol were also evaluated to draw reliable conclusions. The purpose of this study was to find a correlation between the adsorption of monoclonal antibodies and their physicochemical properties. Therefore, the impact of isoelectric point, molar mass, protein glycosylation, and hydrophobicity was investigated. The adsorption of intact antibodies on the stationary phase was significantly higher than that of proteins of similar size, isoelectric point, or hydrophobicity. The present study also demonstrates the unique behavior of monoclonal antibodies, contributing some unwanted and unpredictable strong secondary interactions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Development of Human Monoclonal Antibodies Against Respiratory Syncytial Virus Using a High Efficiency Human Hybridoma Technique.

    Science.gov (United States)

    Alvarado, Gabriela; Crowe, James E

    2016-01-01

    Human monoclonal antibodies against RSV have high potential for use as prophylaxis or therapeutic molecules, and they also can be used to define the structure of protective epitopes for rational vaccine design. In the past, however, isolation of human monoclonal antibodies was difficult and inefficient. Here, we describe contemporary methods for activation and proliferation of primary human memory B cells followed by cytofusion to non-secreting myeloma cells by dielectrophoresis to generate human hybridomas secreting RSV-specific monoclonal antibodies. We also provide experimental methods for screening human B cell lines to obtain RSV-specific lines, especially lines secreting neutralizing antibodies.

  2. 78 FR 7438 - Prospective Grant of Exclusive License: Development of Human Monoclonal Antibodies Against DR4

    Science.gov (United States)

    2013-02-01

    ... Human Monoclonal Antibodies Against DR4 AGENCY: National Institutes of Health, Public Health Service... Monoclonal Antibodies Against DR4'' (HHS Ref. No. E-158-2010/0) to Customized Biosciences, Inc., which is... relates to the development of two human monoclonal antibodies (mAbs) that bind to death receptor 4 (``DR4...

  3. Generation of monoclonal antibodies for the assessment of protein purification by recombinant ribosomal coupling

    DEFF Research Database (Denmark)

    Kristensen, Janni; Sperling-Petersen, Hans Uffe; Mortensen, Kim Kusk

    2005-01-01

    ) followed by expression in an rpL23 deficient strain of E. coli. This allowed for the isolation of ribsomes with covalently coupled target proteins which could be efficiently purified by centrifugation after in vitro proteolysis at a specific site incorporated between rpL23 and the target protein. rpL23-GFP......-His is among the fusion proteins used in our previous study for ribosomal coupling of C-terminally His-tagged green fluorescent protein. To assess the efficiency of separation of target protein from ribosomes, by site-specific proteolysis, we required monoclonal antibodies directed against rpL23 and GFP. We...... therefore purified rpL23-GFP-His, rpL23-His and GFP from E. coli recombinants using affinity, ion exchange and hydrophobic interaction chromatography. These proteins could be purified with yields of 150, 150 and 1500 microg per gram cellular wet weight, respectively. However, rpL23-GFP-His could only...

  4. Detection and Quantitation of Afucosylated N-Linked Oligosaccharides in Recombinant Monoclonal Antibodies Using Enzymatic Digestion and LC-MS

    Science.gov (United States)

    Du, Yi; May, Kimberly; Xu, Wei; Liu, Hongcheng

    2012-07-01

    The presence of N-linked oligosaccharides in the CH2 domain has a significant impact on the structure, stability, and biological functions of recombinant monoclonal antibodies. The impact is also highly dependent on the specific oligosaccharide structures. The absence of core-fucose has been demonstrated to result in increased binding affinity to Fcγ receptors and, thus, enhanced antibody-dependent cellular cytotoxicity (ADCC). Therefore, a method that can specifically determine the level of oligosaccharides without the core-fucose (afucosylation) is highly desired. In the current study, recombinant monoclonal antibodies and tryptic peptides from the antibodies were digested using endoglycosidases F2 and H, which cleaves the glycosidic bond between the two primary GlcNAc residues. As a result, various oligosaccharides of either complex type or high mannose type that are commonly observed for recombinant monoclonal antibodies are converted to either GlcNAc residue only or GlcNAc with the core-fucose. The level of GlcNAc represents the sum of all afucosylated oligosaccharides, whereas the level of GlcNAc with the core-fucose represents the sum of all fucosylated oligosaccharides. LC-MS analysis of the enzymatically digested antibodies after reduction provided a quick estimate of the levels of afucosylation. An accurate determination of the level of afucosylation was obtained by LC-MS analysis of glycopeptides after trypsin digestion.

  5. Impact of IgG Fc-Oligosaccharides on Recombinant Monoclonal Antibody Structure, Stability, Safety, and Efficacy.

    Science.gov (United States)

    Liu, Hongcheng; Nowak, Christine; Andrien, Bruce; Shao, Mei; Ponniah, Gomathinayagam; Neill, Alyssa

    2017-09-01

    Glycosylation of the conserved asparagine residue in the CH2 domain is the most common posttranslational modification of recombinant monoclonal antibodies. Ideally, a consistent oligosaccharide profile should be maintained from early clinical material to commercial material for the development of recombinant monoclonal therapeutics, though variation in the profile is a typical result of process changes. The risk of oligosaccharide variation posed to further development is required to be thoroughly evaluated based on its impact on antibody structure, stability, efficacy and safety. The variation should be controlled within a range so that there is no detrimental impact on safety and efficacy and thus allowing the use of early phase safety and efficacy data to support project advancement to later phase. This review article focuses on the current scientific understanding of the commonly observed oligosaccharides found in recombinant monoclonal antibodies and their impact on structure, stability and biological functions, which are the basis to evaluate safety and efficacy. It also provides a brief discussion on critical quality attribute (CQA) assessment with regard to oligosaccharides based on the mechanism of action (MOA). © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1173-1181, 2017. © 2017 American Institute of Chemical Engineers.

  6. Human monoclonal antibodies: the residual challenge of antibody immunogenicity.

    Science.gov (United States)

    Waldmann, Herman

    2014-01-01

    One of the major reasons for seeking human monoclonal antibodies has been to eliminate immunogenicity seen with rodent antibodies. Thus far, there has yet been no approach which absolutely abolishes that risk for cell-binding antibodies. In this short article, I draw attention to classical work which shows that monomeric immunoglobulins are intrinsically tolerogenic if they can be prevented from creating aggregates or immune complexes. Based on these classical studies two approaches for active tolerization to therapeutic antibodies are described.

  7. Monoclonal antibody against recombinant Fasciola gigantica cathepsin L1H could detect juvenile and adult cathepsin Ls of Fasciola gigantica.

    Science.gov (United States)

    Wongwairot, Sirima; Kueakhai, Pornanan; Changklungmoa, Narin; Jaikua, Wipaphorn; Sansri, Veerawat; Meemon, Krai; Songkoomkrong, Sineenart; Riengrojpitak, Suda; Sobhon, Prasert

    2015-01-01

    Cathepsin Ls (CatLs), the major cysteine protease secreted by Fasciola spp., are important for parasite digestion and tissue invasion. Fasciola gigantica cathepsin L1H (FgCatL1H) is the isotype expressed in the early stages for migration and invasion. In the present study, a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1H (rFgCatL1H) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with recombinant proFgCatL1H (rproFgCatL1H). This MoAb is an immunoglobulin (Ig)G1 with κ light chain isotype. The MoAb reacted specifically with rproFgCatL1H, the native FgCatL1H at a molecular weight (MW) 38 to 48 kDa in the extract of whole body (WB) of metacercariae and newly excysted juvenile (NEJ) and cross-reacted with rFgCatL1 and native FgCatLs at MW 25 to 28 kDa in WB of 2- and 4-week-old juveniles, adult, and adult excretory-secretory (ES) fractions by immunoblotting and indirect ELISA. It did not cross-react with antigens in WB fractions from other parasites, including Gigantocotyle explanatum, Paramphistomum cervi, Gastrothylax crumenifer, Eurytrema pancreaticum, Setaria labiato-papillosa, and Fischoederius cobboldi. By immunolocalization, MoAb against rFgCatL1H reacted with the native protein in the gut of metacercariae and NEJ and also cross-reacted with CatL1 in 2- and 4-week-old juveniles and adult F. gigantica. Therefore, FgCatL1H and its MoAb may be used for immunodiagnosis of both early and late fasciolosis in ruminants and humans.

  8. Expression and characterization of recombinant human serum ...

    African Journals Online (AJOL)

    It was specifically recognized by the anti-human HSA antibody and CP antibody in Western blotting assay. In vitro, the recombinant HSA-CP can stimulate HEK293 cell proliferation. In Zucker diabetic fatty (ZDF) rats, 12 weeks recombinant HSA-CP treatment could prevent the accumulation of glomerular extracellular matrix, ...

  9. Humanization and simultaneous optimization of monoclonal antibody.

    Science.gov (United States)

    Kuramochi, T; Igawa, T; Tsunoda, H; Hattori, K

    2014-01-01

    Antibody humanization is an essential technology for reducing the potential risk of immunogenicity associated with animal-derived antibodies and has been applied to a majority of the therapeutic antibodies on the market. For developing an antibody molecule as a pharmaceutical at the current biotechnology level, however, other properties also have to be considered in parallel with humanization in antibody generation and optimization. This section describes the critical properties of therapeutic antibodies that should be sufficiently qualified, including immunogenicity, binding affinity, physiochemical stability, expression in host cells and pharmacokinetics, and the basic methodologies of antibody engineering involved. By simultaneously optimizing the antibody molecule in the light of these properties, it should prove possible to shorten the research and development period necessary to identify a highly qualified clinical candidate and consequently accelerate the start of the clinical trial.

  10. Recombinant Human Papillomavirus (HPV) Nonavalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) nonavalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  11. Recombinant Human Papillomavirus (HPV) Quadrivalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) quadrivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  12. Recombinant Human Papillomavirus (HPV) Bivalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) bivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  13. Self-Assembly of the Recombinant Capsid Protein of a Swine Norovirus into Virus-Like Particles and Evaluation of Monoclonal Antibodies Cross-Reactive with a Human Strain from Genogroup II

    NARCIS (Netherlands)

    Almanza, H.; Cubillos, C.; Angulo, I.; Mateos, F.; Castön, J.R.; Poel, van der W.H.M.; Vinje, J.; Bárcena, J.; Mena, I.

    2008-01-01

    Noroviruses (NoVs) are responsible for the majority of gastroenteritis outbreaks in humans. Recently, NoV strains which are genetically closely related to human genogroup II (GII) NoVs have been detected in fecal specimens from swine. These findings have raised concern about the possible role of

  14. Development of novel mouse hybridomas producing monoclonal antibodies specific to human and mouse nucleolar protein SURF-6.

    Science.gov (United States)

    Polzikov, Mikhail A; Kordyukova, Maria Yu; Zavalishina, Larisa E; Magoulas, Charalambos; Zatsepina, Olga V

    2012-02-01

    SURF-6 is an evolutionarily conserved nucleolar protein that is important for cell viability; however, its function in mammals still remains uncertain. The aim of this study is to generate monoclonal antibodies to human SURF-6 protein suitable for fundamental and biomedical research. The full-size human SURF-6 was expressed as a recombinant GST-fusion protein and used as an antigen to generate monoclonal antibodies, S79 and S148, specific for SURF-6. The monoclonal antibody produced by hybridoma clone S79 specifically recognizes endogenous SURF-6 by Western and immunofluorescence analyses in various cultured human cells, and by immunohistochemistry in paraffin-embedded sections of human breast cancer samples. Moreover, S79 immunoprecipitates protein complexes containing SURF-6 from HeLa cells extracts. The antibody S79 recognizes SURF-6 only in human cells; however, the antibody produced by hybridoma clone S148 can detect SURF-6 of human and mouse origin. Monoclonal antibodies to the nucleolar protein SURF-6 described in this work can be a useful tool for studies of ribosome biogenesis in normal and cancer cells.

  15. Fasciola gigantica: production and characterization of a monoclonal antibody against recombinant cathepsin B3.

    Science.gov (United States)

    Anuracpreeda, Panat; Songkoomkrong, Sineenart; Sethadavit, Manussabhorn; Chotwiwatthanakun, Charoonroj; Tinikul, Yotsawan; Sobhon, Prasert

    2011-02-01

    A number of monoclonal antibodies (MoAbs) against a recombinant cathepsin B3 (rCatB3) of Fasciola gigantica were produced in BALB/c mice. Reactivity and specificity of these MoAbs were assessed by indirect ELISA and immunoblotting techniques. Six stable clones, namely 1C4, 1E9, 2E5, 2F9, 5B4, 5D7 were obtained. All MoAbs reacted with rCatB3 at molecular weight (MW) 37 kDa as well as the glycosylated peptide at 55-75 kDa and with the native CatB3 at MW 37 kDa in WB extracts of metacercariae (Met) and newly excysted juveniles (NEJ). It was found to be IgG(1) and λ light chain isotypes. Immunolocalization of CatB3 in metacercariae, NEJ, 4-week-old juvenile and adult F. gigantica performed by immunoperoxidase technique by using these MoAbs as probes indicated that CatB3 was present in high concentration in the caecal epithelium and caecal lumen of the Met and NEJ, but not in the 4-week-old juvenile and adult fluke. The MoAbs show no cross-reactions with antigens of other parasites including Gigantocotyl explanatum, Eurytrema pancreaticum, Paramphistomum cervi, Schistosoma spindale, S. mansoni, Haemonchus placei and Setaria labiato-papillosa. Thus, it is possible that these MoAbs could be a good candidate for immunodiagnosis of fasciolosis. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. 77 FR 9678 - Prospective Grant of Exclusive License: The Development of Human Anti-CD22 Monoclonal Antibodies...

    Science.gov (United States)

    2012-02-17

    ... Human Anti-CD22 Monoclonal Antibodies for the Treatment of Human Cancers and Autoimmune Disease AGENCY... Monoclonal Antibodies Against CD22'' , U.S. patent application 12/934,214 entitled ``Human Monoclonal... and m972 (SMB-002) monoclonal antibodies as therapies for the treatment of B cell cancers and...

  17. Generation of Recombinant Schmallenberg Virus Nucleocapsid Protein in Yeast and Development of Virus-Specific Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Justas Lazutka

    2014-01-01

    Full Text Available Schmallenberg virus (SBV, discovered in continental Europe in late 2011, causes mild clinical signs in adult ruminants, including diarrhoea and reduced milk yield. However, fetal infection can lead to severe malformation in newborn offspring. To develop improved reagents for SBV serology, a high-level yeast expression system was employed to produce recombinant SBV nucleocapsid (N protein. Recombinant SBV N protein was investigated as an antigen in SBV-specific IgG enzyme immunoassay and used for generation of monoclonal antibodies (MAbs. Yeast-expressed SBV N protein was reactive with anti-SBV IgG-positive cow serum specimens collected from different farms of Lithuania. After immunization of mice with recombinant SBV N protein, four MAbs were generated. The MAbs raised against recombinant SBV N protein reacted with native viral nucleocapsids in SBV-infected BHK cells by immunofluorescence assay. The reactivity of recombinant N protein with SBV-positive cow serum specimens and the ability of the MAbs to recognize virus-infected cells confirm the antigenic similarity between yeast-expressed SBV N protein and native viral nucleocapsids. Our study demonstrates that yeast expression system is suitable for high-level production of recombinant SBV N protein and provides the first evidence on the presence of SBV-specific antibodies in cow serum specimens collected in Lithuania.

  18. [Effect of monoclonal antibodies against LI-cadherin on the proliferation of human hepatocellular carcinoma cells].

    Science.gov (United States)

    Chen, Xiao-ting; DU, Hong-yan; Yuan, Shao-fei; Wang, Sen-ming; Li, Ming

    2009-05-01

    To obtain monoclonal antibodies (mAb) against LI-cadherin and investigate their effects on the proliferation of human hepatocellular carcinoma cells. Balb/c mice were immunized with recombinant LI-cadherin, and hybridoma cell lines secreting monoclonal antibodies against LI-cadherin were established with routine cell fusion and subcloning approach. The specificity of these mAbs was determined by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The effect of the mAbs obtained on the growth of HepG2 cells was assessed using inverted microscope and MTT assay. Two hybridoma cell lines (F001 and F002) stably secreting specific mAbs were obtained. Western blot analysis showed that the two antibodies specifically recognized LI-cadherin antigen derived from human eucaryotic cells or tissue. Treatment of the HepG2 cells with the mAbs resulted in reduced viable cell number and changes in the cell morphologies, and the two mAbs inhibited the proliferation of HepG2 cells in a concentration-dependent manner (Pcells in vitro, which facilitates further study of the relationship between LI-cadherin and tumors.

  19. Application of a human monoclonal antibody in a rapid competitive anti-HIV ELISA.

    Science.gov (United States)

    Döpel, S H; Porstmann, T; Grunow, R; Jungbauer, A; Von Baehr, R

    1989-01-17

    The ELISA is the established screening technique for the detection of antibodies directed against HIV. The first generation assays, mostly based on the sandwich principle, employed purified virus from cell culture and gave both false-positive and false-negative results. Sandwich-type assays preferentially detect IgG antibodies, require a high serum dilution and are two-step procedures. In order to detect an immune response as early as possible after infection anti-HIV antibodies of the IgM class should also be measured. To this end a competitive ELISA has been developed using a solid phase-adsorbed recombinant HIV envelope protein and an enzyme-labelled human monoclonal antibody. This detects both IgM and IgG antibodies, the results are available within 1 h and a serum predilution is not necessary.

  20. Hersintuzumab: A novel humanized anti-HER2 monoclonal antibody induces potent tumor growth inhibition.

    Science.gov (United States)

    Amiri, Mohammad Mehdi; Golsaz-Shirazi, Forough; Soltantoyeh, Tahereh; Hosseini-Ghatar, Reza; Bahadori, Tannaz; Khoshnoodi, Jalal; Navabi, Shadi Sadat; Farid, Samira; Karimi-Jafari, Mohammad Hossein; Jeddi-Tehrani, Mahmood; Shokri, Fazel

    2017-10-06

    Humanized monoclonal antibodies (mAbs) against HER2 including trastuzumab and pertuzumab are widely used to treat HER2 overexpressing metastatic breast cancers. These two mAbs recognize distinct epitopes on HER2 and their combination induces a more potent blockade of HER2 signaling than trastuzumab alone. Recently, we have reported characterization of a new chimeric mAb (c-1T0) which binds to an epitope different from that recognized by trastuzumab and significantly inhibits proliferation of HER2 overexpressing tumor cells. Here, we describe humanization of this mAb by grafting all six complementarity determining regions (CDRs) onto human variable germline genes. Humanized VH and VL sequences were synthesized and ligated to human γ1 and κ constant region genes using splice overlap extension (SOE) PCR. Subsequently, the humanized antibody designated hersintuzumab was expressed and characterized by ELISA, Western blot and flow cytometry. The purified humanized mAb binds to recombinant HER2 and HER2-overexpressing tumor cells with an affinity comparable with the chimeric and parental mouse mAbs. It recognizes an epitope distinct from those recognized by trastuzumab and pertuzumab. Binding of hersintuzumab to HER2 overexpressing tumor cells induces G1 cell cycle arrest, inhibition of ERK and AKT signaling pathways and growth inhibition. Moreover, hersintuzumab could induce antibody-dependent cell cytotoxicity (ADCC) on BT-474 cells. This new humanized mAb is a potentially valuable tool for single or combination breast cancer therapy.

  1. Recombinant human endostatin reduces hypertrophic scar ...

    African Journals Online (AJOL)

    Department of Otolaryngology, First Affiliated Hospital of Chongqing Medical University, Chongqing,. China; pearl1984@sina.com. 3. Department of Burn and Plastic Surgery, First Affiliated Hospital of Chongqing Medical University,. Chongqing, China; CQXuebin@126.com. Abstract. Background: Recombinant human ...

  2. The Role of Recombinant Genetics in Humanism.

    Science.gov (United States)

    Jacobs, Troy A.

    1983-01-01

    To eliminate the public's fear of recombinant genetics the important link between science and the humanities should be part of the educational system. Universal applied genetics guidelines are needed that encompass philosophical and technical issues. Biological advances can revitalize humankind in the future. (AM)

  3. Antigen-specific human monoclonal antibodies from transgenic mice.

    Science.gov (United States)

    Mompó, Susana Magadán; González-Fernández, Africa

    2014-01-01

    Due to the difficulties found when generating fully human monoclonal antibodies (mAbs) by the traditional method, several efforts have attempted to overcome these problems, with varying levels of success. One approach has been the development of transgenic mice carrying immunoglobulin (Ig) genes in germ line configuration. The engineered mouse genome can undergo productive rearrangement in the B cell population, with the generation of mouse B lymphocytes expressing human Ig (hIg) chains. To avoid the expression of mouse heavy or light chains, the endogenous mouse Ig (mIg) loci must be silenced by gene-targeting techniques. Subsequently, to obtain antigen-specific mAbs, conventional immunization protocols can be followed and the mAb technique used (fusion of activated B cells with mouse myeloma cells, screening, cloning, freezing, and testing) with these animals expressing human Ig genes. This chapter describes the type of transgenic knockout mice generated for various research groups, provides examples of human mAbs developed by research groups and companies, and includes protocols of immunization, generation, production, and purification of human mAbs from such mice. In addition, it also addresses the problems detected, and includes some of the methods that can be used to analyze functional activities with human mAbs.

  4. Two monoclonal anti-CD3 antibodies can induce different events in human T lymphocyte activation

    NARCIS (Netherlands)

    Roosnek, E. E.; van Lier, R. A.; Aarden, L. A.

    1987-01-01

    Two monoclonal antibodies, WT32 and CLB-T3/4.2a, directed against the CD3 complex were used to study the mechanism of activation of human peripheral T lymphocytes. WT32, a mouse monoclonal IgG2a antibody with a low avidity (much less than OKT3) for the CD3 complex, effectively induces mitogenesis of

  5. Molecular Insights into Fully Human and Humanized Monoclonal Antibodies: What are the Differences and Should Dermatologists Care?

    Science.gov (United States)

    Mallbris, Lotus; Davies, Julian; Glasebrook, Andrew; Tang, Ying; Glaesner, Wolfgang; Nickoloff, Brian J

    2016-07-01

    In recent years, a large number of therapeutic monoclonal antibodies have come to market to treat a variety of conditions including patients with immune-mediated chronic inflammation. Distinguishing the relative clinical efficacy and safety profiles of one monoclonal antibody relative to another can be difficult and complex due to different clinical designs and paucity of head-to-head comparator studies. One distinguishing feature in interpreting clinical trial data by dermatologists may begin by determining whether a monoclonal antibody is fully human or humanized, which can be discerned by the generic name of the drug. Herein, this commentary highlights the distinctions and similarities of fully human and humanized monoclonal antibodies in their nomenclature, engineering, and clinical profiles. While there are a number of differences between these types of monoclonal antibodies, current evidence indicates that this designation does not impart any measurable impact on overall clinical efficacy and safety profiles of a given drug. Based on molecular insights provided in this commentary, it is clear that each monoclonal antibody, irrespective of being fully human or humanized, should be individually assessed for its clinical impact regarding safety and efficacy. Going beyond the type of generic name ascribed to a monoclonal antibody will be an ever-increasing theme for dermatologists as more therapeutic monoclonal antibodies emerge to potentially treat a wider scope of diseases with cutaneous manifestations.

  6. [Construction expression and biologic activity of recombinant human sCR1 eucaryotic cell].

    Science.gov (United States)

    Wang, Guang-lan; Gong, Cui-cui; Wang, Wen-li; Zhang, Chang-yuan; Liu, Ya-li; He, Pei-xia; Zheng, Shu-na; Chen, Xiang-lin

    2008-05-01

    To express human soluble complement receptor type 1(sCR1)protein using ferment cell secreting type carrier and study the extraorgan biologic activity of recombinant human sCR1 fusion protein. Total human RNA was extracted from peripheral blood. The full length cDNA of human sCR1 gene was obtained by RT-PCR and them, cloned into Pichia pastoris eukaryotic expression vector pPIC9k to construct the recombinant plasmid pPIC9k-sCR1 containing human sCR1.After identified by DNA sequencing, the recombinant plasmid pPIC9k-sCR1 was transformed into Pichia pastoris SMD1168. The ferment cell line of the recombinant sCR1 which was chosen by G418 resistance was identified by PCR, After methanol induction, the expressed protein products were verified by SDS-PAGE and Western blot, purified by Ni(2+)-NTA agarose affinity chromatography, and its biologic activity was identified. The obtained Pichia pastoris secretion type yeast carrier pPIC9k-sCR1 was chosen by G418 and identified by PCR to get a highly copied and integral recombinant ferment cell line. The recombinant human sCR1 fusion protein was expressed by yeast cells containing pPIC9k-sCR1 induced by methanol. It was a protein band about M(r) 31 000 in gel, which could be identified by CD35 of anti-sCR1 protein monoclonal antibody with Western blotting technique. The highly purified sCR1 fusion protein and its biologic activity were detected obtained by Ni(2+)-NTA agarose affinity chromatography. The recombinant human sCR1 fusion protein can be highly expressed in the Pichia pastoris expression system, which resembles the human natural protein's antigenicity and biologic activity.

  7. Specific MR imaging of human-lymphocytes by monoclonal antibody-guided dextran-magnetite particles

    NARCIS (Netherlands)

    Bulte, J. W. M.; Hoekstra, Y; Kamman, R. L.; Magin, R. L.; Webb, A. G.; Briggs, R. W.; Go, K. G.; Hulstaert, C. E.; Miltenyi, S.; The, T. Hauw; de Leij, L

    Human lymphocytes were labeled with biotinylated anti-lymphocyte-directed monoclonal antibodies, to which streptavidin and subsequently biotinylated dextran-magnetite particles were coupled. This labeling resulted in a strong and selective negative contrast enhancement of lymphocyte suspensions at

  8. Human monoclonal antibody as prophylaxis for SARS coronavirus infection in ferrets

    NARCIS (Netherlands)

    ter Meulen, Jan; Bakker, Alexander B. H.; van den Brink, Edward N.; Weverling, Gerrit J.; Martina, Byron E. E.; Haagmans, Bart L.; Kuiken, Thijs; de Kruif, John; Preiser, Wolfgang; Spaan, Willy; Gelderblom, Hans R.; Goudsmit, Jaap; Osterhaus, Albert D. M. E.

    2004-01-01

    SARS coronavirus continues to cause sporadic cases of severe acute respiratory syndrome (SARS) in China. No active or passive immunoprophylaxis for disease induced by SARS coronavirus is available. We investigated prophylaxis of SARS coronavirus infection with a neutralising human monoclonal

  9. Generation of Recombinant Monoclonal Antibodies from Immunised Mice and Rabbits via Flow Cytometry and Sorting of Antigen-Specific IgG+ Memory B Cells.

    Science.gov (United States)

    Starkie, Dale O; Compson, Joanne E; Rapecki, Stephen; Lightwood, Daniel J

    2016-01-01

    Single B cell screening strategies, which avoid both hybridoma fusion and combinatorial display, have emerged as important technologies for efficiently sampling the natural antibody repertoire of immunized animals and humans. Having access to a range of methods to interrogate different B cell subsets provides an attractive option to ensure large and diverse panels of high quality antibody are produced. The generation of multiple antibodies and having the ability to find rare B cell clones producing IgG with unique and desirable characteristics facilitates the identification of fit-for-purpose molecules that can be developed into therapeutic agents or research reagents. Here, we describe a multi-parameter flow cytometry single-cell sorting technique for the generation of antigen-specific recombinant monoclonal antibodies from single IgG+ memory B cells. Both mouse splenocytes and rabbit PBMC from immunised animals were used as a source of B cells. Reagents staining both B cells and other unwanted cell types enabled efficient identification of class-switched IgG+ memory B cells. Concurrent staining with antigen labelled separately with two spectrally-distinct fluorophores enabled antigen-specific B cells to be identified, i.e. those which bind to both antigen conjugates (double-positive). These cells were then typically sorted at one cell per well using FACS directly into a 96-well plate containing reverse transcriptase reaction mix. Following production of cDNA, PCR was performed to amplify cognate heavy and light chain variable region genes and generate transcriptionally-active PCR (TAP) fragments. These linear expression cassettes were then used directly in a mammalian cell transfection to generate recombinant antibody for further testing. We were able to successfully generate antigen-specific recombinant antibodies from both the rabbit and mouse IgG+ memory B cell subset within one week. This included the generation of an anti-TNFR2 blocking antibody from mice

  10. Generation of Recombinant Monoclonal Antibodies from Immunised Mice and Rabbits via Flow Cytometry and Sorting of Antigen-Specific IgG+ Memory B Cells.

    Directory of Open Access Journals (Sweden)

    Dale O Starkie

    Full Text Available Single B cell screening strategies, which avoid both hybridoma fusion and combinatorial display, have emerged as important technologies for efficiently sampling the natural antibody repertoire of immunized animals and humans. Having access to a range of methods to interrogate different B cell subsets provides an attractive option to ensure large and diverse panels of high quality antibody are produced. The generation of multiple antibodies and having the ability to find rare B cell clones producing IgG with unique and desirable characteristics facilitates the identification of fit-for-purpose molecules that can be developed into therapeutic agents or research reagents. Here, we describe a multi-parameter flow cytometry single-cell sorting technique for the generation of antigen-specific recombinant monoclonal antibodies from single IgG+ memory B cells. Both mouse splenocytes and rabbit PBMC from immunised animals were used as a source of B cells. Reagents staining both B cells and other unwanted cell types enabled efficient identification of class-switched IgG+ memory B cells. Concurrent staining with antigen labelled separately with two spectrally-distinct fluorophores enabled antigen-specific B cells to be identified, i.e. those which bind to both antigen conjugates (double-positive. These cells were then typically sorted at one cell per well using FACS directly into a 96-well plate containing reverse transcriptase reaction mix. Following production of cDNA, PCR was performed to amplify cognate heavy and light chain variable region genes and generate transcriptionally-active PCR (TAP fragments. These linear expression cassettes were then used directly in a mammalian cell transfection to generate recombinant antibody for further testing. We were able to successfully generate antigen-specific recombinant antibodies from both the rabbit and mouse IgG+ memory B cell subset within one week. This included the generation of an anti-TNFR2 blocking

  11. Epitope tagging: a monoclonal antibody specific for recombinant fusion proteins in plants.

    Science.gov (United States)

    Lawrence, Susan D; Novak, Nicole G; Slack, Jeffrey M

    2003-09-01

    The easy identification of a recombinant protein in plant material becomes increasingly relevant as more transgenic plants are used for research and commercial applications. Tagging recombinant proteins with a small peptide (epitope) can perform such a task. However, available epitope antibodies will also cross-react with endogenous plant proteins at a level that may be unacceptable. Here we describe the new epitope antibody AcV5. Whether it is attached to the carbooxyl terminal end of enhanced green fluorescent protein (EGFP) or the Bacillus thuringiensis endotoxin Cry3A, these proteins remain functional. In addition, using less than 250 pg AcV5-tagged EGFP produces a strong signal on Western blots with no cross-reactivity of proteins from a broad range of plants of agronomic importance.

  12. Monoclonal antibodies to human butyrylcholinesterase reactive with butyrylcholinesterase in animal plasma.

    Science.gov (United States)

    Peng, Hong; Brimijoin, Stephen; Hrabovska, Anna; Krejci, Eric; Blake, Thomas A; Johnson, Rudolph C; Masson, Patrick; Lockridge, Oksana

    2016-01-05

    Five mouse anti-human butyrylcholinesterase (BChE) monoclonal antibodies bind tightly to native human BChE with nanomolar dissociation constants. Pairing analysis in the Octet system identified the monoclonal antibodies that bind to overlapping and independent epitopes on human BChE. The nucleotide and amino acid sequences of 4 monoclonal antibodies are deposited in GenBank. Our goal was to determine which of the 5 monoclonal antibodies recognize BChE in the plasma of animals. Binding of monoclonal antibodies 11D8, B2 18-5, B2 12-1, mAb2 and 3E8 to BChE in animal plasma was measured using antibody immobilized on Pansorbin cells and on Dynabeads Protein G. A third method visualized binding by the shift of BChE activity bands on nondenaturing gels stained for BChE activity. Gels were counterstained for carboxylesterase activity. The three methods agreed that B2 18-5 and mAb2 have broad species specificity, but the other monoclonal antibodies interacted only with human BChE, the exception being 3E8, which also bound chicken BChE. B2 18-5 and mAb2 recognized BChE in human, rhesus monkey, horse, cat, and tiger plasma. A weak response was found with rabbit BChE. Monoclonal mAb2, but not B2 18-5, bound pig and bovine BChE. Gels stained for carboxylesterase activity confirmed that plasma from humans, monkey, pig, chicken, and cow does not contain carboxylesterase, but plasma from horse, cat, tiger, rabbit, guinea pig, mouse, and rat has carboxylesterase. Rabbit plasma carboxylesterase hydrolyzes butyrylthiocholine. In conclusion monoclonal antibodies B2 18-5 and mAb2 can be used to immuno extract BChE from the plasma of humans, monkey and other animals. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. A Robust High Throughput Platform to Generate Functional Recombinant Monoclonal Antibodies Using Rabbit B Cells from Peripheral Blood

    Science.gov (United States)

    Seeber, Stefan; Ros, Francesca; Thorey, Irmgard; Tiefenthaler, Georg; Kaluza, Klaus; Lifke, Valeria; Fischer, Jens André Alexander; Klostermann, Stefan; Endl, Josef; Kopetzki, Erhard; Pashine, Achal; Siewe, Basile; Kaluza, Brigitte; Platzer, Josef; Offner, Sonja

    2014-01-01

    We have developed a robust platform to generate and functionally characterize rabbit-derived antibodies using B cells from peripheral blood. The rapid high throughput procedure generates a diverse set of antibodies, yet requires only few animals to be immunized without the need to sacrifice them. The workflow includes (i) the identification and isolation of single B cells from rabbit blood expressing IgG antibodies, (ii) an elaborate short term B-cell cultivation to produce sufficient monoclonal antigen specific IgG for comprehensive phenotype screens, (iii) the isolation of VH and VL coding regions via PCR from B-cell clones producing antigen specific and functional antibodies followed by the sequence determination, and (iv) the recombinant expression and purification of IgG antibodies. The fully integrated and to a large degree automated platform (demonstrated in this paper using IL1RL1 immunized rabbits) yielded clonal and very diverse IL1RL1-specific and functional IL1RL1-inhibiting rabbit antibodies. These functional IgGs from individual animals were obtained at a short time range after immunization and could be identified already during primary screening, thus substantially lowering the workload for the subsequent B-cell PCR workflow. Early availability of sequence information permits one to select early-on function- and sequence-diverse antibodies for further characterization. In summary, this powerful technology platform has proven to be an efficient and robust method for the rapid generation of antigen specific and functional monoclonal rabbit antibodies without sacrificing the immunized animal. PMID:24503933

  14. A novel monoclonal antibody for detection of galectin-9 in tissue sections: application to human tissues infected by oncogenic viruses

    Directory of Open Access Journals (Sweden)

    Barjon Clément

    2012-07-01

    Full Text Available Abstract Background Galectin-9 is a mammalian lectin which possesses immunosuppressive properties. Excessive production of galectin-9 has been reported in two types of human virus-associated diseases chronic hepatitis C and nasopharyngeal carcinoma associated to the Epstein-Barr virus. The objective of this study was to produce new monoclonal antibodies targeting galectin-9 in order to improve its detection in clinical samples, especially on tissue sections analysed by immunohistochemistry. Methods Hybridomas were produced through immunization of mice with the recombinant c-terminus part of galectin-9 (residues 191 to 355 of the long isoform and semi-solid fusion of spleen cells with Sp2/0 cells. Monoclonal antibodies were characterized using ELISA, epitope mapping, western blot and immunohistochemistry. Results We selected seven hybridomas producing antibodies reacting with our recombinant c-terminus galectin-9 in ELISA. Five of them reacted with the epitope “TPAIPPMMYPHPA” (common to all isoforms, residues 210 to 222 of the long isoform and stained all three isoforms of galectin-9 analysed by western blot. One of them, 1G3,demonstrated very good sensitivity and specificity when used for immunohistochemistry. Using 1G3, we could confirm the intense and constant expression of galectin-9 by Epstein-Barr virus positive malignant cells from nasopharyngeal carcinomas. In most samples, specific staining was detected in both cytoplasm and nuclei. Galectin-9 was also detected in liver biopsies from patients infected by the human hepatitis C or B viruses with expression not only in inflammatory leucocytes and Kupffer cells, but also in hepatocytes. In contrast, galectin-9 was virtually absent in non-infected liver specimens. Conclusion The 1G3 monoclonal antibody will be a powerful tool to assess galectin-9 expression and distribution especially in diseases related to oncogenic viruses.

  15. Human monoclonal antibodies broadly neutralizing against influenza B virus.

    Directory of Open Access Journals (Sweden)

    Mayo Yasugi

    2013-02-01

    Full Text Available Influenza virus has the ability to evade host immune surveillance through rapid viral genetic drift and reassortment; therefore, it remains a continuous public health threat. The development of vaccines producing broadly reactive antibodies, as well as therapeutic strategies using human neutralizing monoclonal antibodies (HuMAbs with global reactivity, has been gathering great interest recently. Here, three hybridoma clones producing HuMAbs against influenza B virus, designated 5A7, 3A2 and 10C4, were prepared using peripheral lymphocytes from vaccinated volunteers, and were investigated for broad cross-reactive neutralizing activity. Of these HuMAbs, 3A2 and 10C4, which recognize the readily mutable 190-helix region near the receptor binding site in the hemagglutinin (HA protein, react only with the Yamagata lineage of influenza B virus. By contrast, HuMAb 5A7 broadly neutralizes influenza B strains that were isolated from 1985 to 2006, belonging to both Yamagata and Victoria lineages. Epitope mapping revealed that 5A7 recognizes 316G, 318C and 321W near the C terminal of HA1, a highly conserved region in influenza B virus. Indeed, no mutations in the amino acid residues of the epitope region were induced, even after the virus was passaged ten times in the presence of HuMAb 5A7. Moreover, 5A7 showed significant therapeutic efficacy in mice, even when it was administered 72 hours post-infection. These results indicate that 5A7 is a promising candidate for developing therapeutics, and provide insight for the development of a universal vaccine against influenza B virus.

  16. Treatment of Lassa virus infection in outbred guinea pigs with first-in-class human monoclonal antibodies.

    Science.gov (United States)

    Cross, Robert W; Mire, Chad E; Branco, Luis M; Geisbert, Joan B; Rowland, Megan M; Heinrich, Megan L; Goba, Augustine; Momoh, Mambu; Grant, Donald S; Fullah, Mohamed; Khan, Sheik Humarr; Robinson, James E; Geisbert, Thomas W; Garry, Robert F

    2016-09-01

    Lassa fever is a significant health threat to West African human populations with hundreds of thousands of annual cases. There are no approved medical countermeasures currently available. Compassionate use of the antiviral drug ribavirin or transfusion of convalescent serum has resulted in mixed success depending on when administered or the donor source, respectively. We previously identified several recombinant human monoclonal antibodies targeting the glycoprotein of Lassa virus with strong neutralization profiles in vitro. Here, we demonstrate remarkable therapeutic efficacy using first-in-class human antibodies in a guinea pig model of Lassa infection thereby presenting a promising treatment alternative. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Free light chain content in culture media reflects recombinant monoclonal antibody productivity and quality.

    Science.gov (United States)

    Bhoskar, Prachi; Belongia, Brett; Smith, Robert; Yoon, Seongkyu; Carter, Tyler; Xu, Jin

    2013-01-01

    Monoclonal antibodies (mAbs) are currently the dominant class of biopharmaceuticals. Due to the high dosage requirements of most mAb therapeutics, high productivity and low aggregation are prevailing criteria during cell line generation and process development. Given that light chains (LCs) play an important role in antibody folding and assembly, and that most mAb producing cell lines also manufacture free LCs, we sought to investigate whether there was a relationship between free LC levels in cell culture media and mAb productivity/quality. To this end, a series of analytical methods were developed in order to quantify free LC content in cell culture media and assess mAb productivity and aggregation levels. Afterwards, conditioned media samples from different cell lines at identical culturing conditions and a single clone under varying culturing conditions were analyzed. Higher LC expression was found to correlate with higher cell viability, higher mAb productivity, and lower aggregation. While LC expression cannot yet be definitively considered the root cause of these phenomena, these results are consistent with the role of LCs in mAb production, suggesting that free LC expression levels may potentially serve as a parameter for cell line generation and cell culture process optimization. © 2013 American Institute of Chemical Engineers.

  18. The epitope structure of Citrus tristeza virus coat protein mapped by recombinant proteins and monoclonal antibodies.

    Science.gov (United States)

    Wu, Guan-Wei; Tang, Min; Wang, Guo-Ping; Wang, Cai-Xia; Liu, Yong; Yang, Fan; Hong, Ni

    2014-01-05

    It has been known that there exists serological differentiation among Citrus tristeza virus (CTV) isolates. The present study reports three linear epitopes (aa 48-63, 97-104, and 114-125) identified by using bacterially expressed truncated coat proteins and ten monoclonal antibodies against the native virions of CTV-S4. Site-directed mutagenesis analysis demonstrated that the mutation D98G within the newly identified epitope (97)DDDSTGIT(104) abolished its reaction to MAbs 1, 4, and 10, and the presence of G98 in HB1-CP also resulted in its failure to recognize the three MAbs. Our results suggest that the conformational differences in the epitope I (48)LGTQQNAALNRDLFLT(63) between the CPs of isolates S4 and HB1 might contribute to the different reactions of two isolates to MAbs 5 and 6. This study provides new information for the antigenic structures of CTV, and will extend the understanding of the processes required for antibody binding and aid the development of epitope-based diagnostic tools. © 2013 Published by Elsevier Inc.

  19. The Use of Humanized Monoclonal Antibodies for the Prevention of Respiratory Syncytial Virus Infection

    Directory of Open Access Journals (Sweden)

    Marcello Lanari

    2013-01-01

    Full Text Available Monoclonal antibodies are widely used both in infants and in adults for several indications. Humanized monoclonal antibodies (palivizumab have been used for many years for the prevention of respiratory syncytial virus infection in pediatric populations (preterm infants, infants with chronic lung disease or congenital heart disease at high risk of severe and potentially lethal course of the infection. This drug was reported to be safe, well tolerated and effective to decrease the hospitalization rate and mortality in these groups of infants by several clinical trials. In the present paper we report the development and the current use of monoclonal antibodies for prophylaxis against respiratory syncytial virus.

  20. Development of Monoclonal Antibodies against CMP-N-Acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 (ST3Gal-I) Recombinant Protein Expressed in E. coli.

    Science.gov (United States)

    Gupta, Anuj Kumar; Kaur, Parvinder; Patil, Harshada; Kadam, Pallavi; Bhanushali, Paresh B; Chugh, Manoj

    2015-01-01

    Aberrant glycosylation is one of the major hallmarks of cancer with altered gene expression signatures of sialyltransferases. ST3Gal-I, a sialyltransferase, is known to play a crucial role in sialylation of T antigen in bladder cancer and it has reported elevated expression in breast carcinogenesis with increased tumor progression stages. The aim of the current study is to develop new monoclonal antibodies (mAbs) against human ST3Gal-I and evaluate their diagnostic potential. We developed a repertoire of stable hybridoma cell lines producing high-affinity IgG antibodies against recombinant human ST3Gal-I, expressed in E. coli BL21-DE3 strain. In order to demonstrate the diagnostic value of the mAbs, various clones were employed for the immunohistochemistry analysis of ST3Gal-I expression in cancerous tissues. Antibodies generated by 7E51C83A10 clone demonstrated a strong and specific fluorescence staining in breast cancer tissue sections and did not exhibit significant background in fibroadenoma sections. In conclusion, the mAbs raised against recombinant ST3Gal-I recognize cellular ST3Gal-I and represent a promising diagnostic tool for the immunodetection of ST3Gal-I expressing cells. Specific-reactivity of clone 7E51C83A10 mAbs towards ST3Gal-I was also confirmed by immunoblotting. Therefore, our observations warrant evaluation of ST3Gal-I as a potential marker for cancer diagnosis at larger scale.

  1. Critical epitopes in the nucleocapsid protein of SFTS virus recognized by a panel of SFTS patients derived human monoclonal antibodies.

    Directory of Open Access Journals (Sweden)

    Li Yu

    Full Text Available BACKGROUND: SFTS virus (SFTSV is a newly discovered pathogen to cause severe fever with thrombocytopenia syndrome (SFTS in human. Successful control of SFTSV epidemic requires better understanding of the antigen target in humoral immune responses to the new bunyavirus infection. METHODOLOGY/PRINCIPAL FINDINGS: We have generated a combinatorial Fab antibody phage library from two SFTS patients recovered from SFTSV infection. To date, 94 unique human antibodies have been generated and characterized from over 1200 Fab antibody clones obtained by screening the library with SFTS purified virions. All those monoclonal antibodies (MAbs recognized the nucleocapsid (N protein of SFTSV while none of them were reactive to the viral glycoproteins Gn or Gc. Furthermore, over screening 1000 mouse monoclonal antibody clones derived from SFTSV virions immunization, 462 clones reacted with N protein, while only 16 clones were reactive to glycoprotein. Furthermore, epitope mapping of SFTSV N protein was performed through molecular simulation, site mutation and competitive ELISA, and we found that at least 4 distinct antigenic epitopes within N protein were recognized by those human and mouse MAbs, in particular mutation of Glu10 to Ala10 abolished or significantly reduced the binding activity of nearly most SFTS patients derived MAbs. CONCLUSIONS/SIGNIFICANCE: The large number of human recombinant MAbs derived from SFTS patients recognized the viral N protein indicated the important role of the N protein in humoral responses to SFTSV infection, and the critical epitopes we defined in this study provided molecular basis for detection and diagnosis of SFTSV infection.

  2. Identification and verification of hybridoma-derived monoclonal antibody variable region sequences using recombinant DNA technology and mass spectrometry.

    Science.gov (United States)

    Babrak, Lmar; McGarvey, Jeffery A; Stanker, Larry H; Hnasko, Robert

    2017-10-01

    Antibody engineering requires the identification of antigen binding domains or variable regions (VR) unique to each antibody. It is the VR that define the unique antigen binding properties and proper sequence identification is essential for functional evaluation and performance of recombinant antibodies (rAb). This determination can be achieved by sequence analysis of immunoglobulin (Ig) transcripts obtained from a monoclonal antibody (MAb) producing hybridoma and subsequent expression of a rAb. However the polyploidy nature of a hybridoma cell often results in the added expression of aberrant immunoglobulin-like transcripts or even production of anomalous antibodies which can confound production of rAb. An incorrect VR sequence will result in a non-functional rAb and de novo assembly of Ig primary structure without a sequence map is challenging. To address these problems, we have developed a methodology which combines: 1) selective PCR amplification of VR from both the heavy and light chain IgG from hybridoma, 2) molecular cloning and DNA sequence analysis and 3) tandem mass spectrometry (MS/MS) on enzyme digests obtained from the purified IgG. Peptide analysis proceeds by evaluating coverage of the predicted primary protein sequence provided by the initial DNA maps for the VR. This methodology serves to both identify and verify the primary structure of the MAb VR for production as rAb. Published by Elsevier Ltd.

  3. Effect of the conserved oligosaccharides of recombinant monoclonal antibodies on the separation by protein A and protein G chromatography.

    Science.gov (United States)

    Gaza-Bulseco, Georgeen; Hickman, Keith; Sinicropi-Yao, Sara; Hurkmans, Karen; Chumsae, Chris; Liu, Hongcheng

    2009-03-20

    Glycosylation of the conserved asparagine residue in CH2 domains of IgG molecules is an important post-translational modification. The presence of oligosaccharides is critical for structure, stability and biological function of IgG antibodies. Effect of the glycosylation states of recombinant monoclonal antibodies on protein A and protein G chromatography was evaluated. Antibodies lacking oligosaccharides eluted later from protein A and earlier from protein G columns than antibodies with oligosaccharides using a gradient of decreasing pH. Interestingly, different types of oligosaccharides also affected the elution of the antibodies. Antibodies with high mannose type oligosaccharides were enriched in later eluting fractions from protein A and earlier eluting fractions from protein G. While antibodies with more mature oligosaccharides, such as core fucosylated biantennary complex oligosaccharides with zero (Gal 0), one (Gal 1) or two (Gal 2) terminal galactoses, were enriched in earlier eluting fractions from protein A and in the later eluting fractions from protein G. However, analysis by enzyme-linked immunosorbent assay (ELISA) revealed that antibody binding affinity to protein A and protein G was not affected by the absence or presence of oligosaccharides. It was thus concluded that the elution difference of antibodies with or without oligosaccharides and antibodies with different types of oligosaccharides were due to differential structural changes around the CH2-CH3 domain interface under the low pH conditions used for protein A and protein G chromatography.

  4. Production of a monoclonal antibody in plants with a humanized N-glycosylation pattern.

    Science.gov (United States)

    Schähs, Matthias; Strasser, Richard; Stadlmann, Johannes; Kunert, Renate; Rademacher, Thomas; Steinkellner, Herta

    2007-09-01

    In recent years, plants have become an attractive alternative for the production of recombinant proteins. However, their inability to perform authentic mammalian N-glycosylation may cause limitations for the production of therapeutics. A major concern is the presence of beta1,2-xylose and core alpha1,3-fucose residues on complex N-linked glycans, as these N-glycan epitopes are immunogenic in mammals. In our attempts towards the humanization of plant N-glycans, we have generated an Arabidopsis thaliana knockout line that synthesizes complex N-glycans lacking immunogenic xylose and fucose epitopes. Here, we report the expression of a monoclonal antibody in these glycan-engineered plants that carry a homogeneous mammalian-like complex N-glycan pattern without beta1,2-xylose and core alpha1,3-fucose. Plant and Chinese hamster ovary (CHO)-derived immunoglobulins (IgGs) exhibited no differences in electrophoretic mobility and enzyme-linked immunosorbent specificity assays. Our results demonstrate the feasibility of a knockout strategy for N-glycan engineering of plants towards mammalian-like structures, thus providing a significant improvement in the use of plants as an expression platform.

  5. Humanization and characterization of an anti-ricin neutralization monoclonal antibody.

    Directory of Open Access Journals (Sweden)

    Wei-Gang Hu

    Full Text Available Ricin is regarded as a high terrorist risk for the public due to its high toxicity and ease of production. Currently, there is no therapeutic or vaccine available against ricin. D9, a murine monoclonal antibody developed previously in our laboratory, can strongly neutralize ricin and is therefore a good candidate for humanization. Humanization of D9 variable regions was achieved by a complementarity-determining region grafting approach. The humanized D9 (hD9 variable regions were further grafted onto human heavy and light chain constant regions to assemble the complete antibody gene. A foot-and-mouth-disease virus-derived 2A self-processing sequence was introduced between heavy and light chain DNA sequences to cleave the recombinant protein into a functional full-length antibody molecule from a single open reading frame driven by a single promoter in an adenoviral vector. After expression in mammalian cells and purification, the hD9 was demonstrated to have equimolar expression of the full-length antibody heavy and light chains. More importantly, the hD9 exhibited high affinity to ricin with K(D of 1.63 nM, comparable to its parental murine D9 (2.55 nM. In a mouse model, intraperitoneal (i.p. administration of hD9, at a low dose of 5 µg per mouse, 4 hours after the i.p. challenge with 5×LD50 ricin was found to rescue 100% of the mice. In addition, administered 6 hours post-challenge, hD9 could still rescue 50% of the mice. The hD9 has the potential to be used for prophylactic or therapeutic purposes against ricin poisoning.

  6. Humanization and characterization of an anti-ricin neutralization monoclonal antibody.

    Science.gov (United States)

    Hu, Wei-Gang; Yin, Junfei; Chau, Damon; Negrych, Laurel M; Cherwonogrodzky, John W

    2012-01-01

    Ricin is regarded as a high terrorist risk for the public due to its high toxicity and ease of production. Currently, there is no therapeutic or vaccine available against ricin. D9, a murine monoclonal antibody developed previously in our laboratory, can strongly neutralize ricin and is therefore a good candidate for humanization. Humanization of D9 variable regions was achieved by a complementarity-determining region grafting approach. The humanized D9 (hD9) variable regions were further grafted onto human heavy and light chain constant regions to assemble the complete antibody gene. A foot-and-mouth-disease virus-derived 2A self-processing sequence was introduced between heavy and light chain DNA sequences to cleave the recombinant protein into a functional full-length antibody molecule from a single open reading frame driven by a single promoter in an adenoviral vector. After expression in mammalian cells and purification, the hD9 was demonstrated to have equimolar expression of the full-length antibody heavy and light chains. More importantly, the hD9 exhibited high affinity to ricin with K(D) of 1.63 nM, comparable to its parental murine D9 (2.55 nM). In a mouse model, intraperitoneal (i.p.) administration of hD9, at a low dose of 5 µg per mouse, 4 hours after the i.p. challenge with 5×LD50 ricin was found to rescue 100% of the mice. In addition, administered 6 hours post-challenge, hD9 could still rescue 50% of the mice. The hD9 has the potential to be used for prophylactic or therapeutic purposes against ricin poisoning.

  7. Biochemical characterization of AMG 102: a neutralizing, fully human monoclonal antibody to human and nonhuman primate hepatocyte growth factor.

    Science.gov (United States)

    Burgess, Teresa L; Sun, Jan; Meyer, Susanne; Tsuruda, Trace S; Sun, Jilin; Elliott, Gary; Chen, Qing; Haniu, Mitsuru; Barron, Will F; Juan, Todd; Zhang, Ke; Coxon, Angela; Kendall, Richard L

    2010-02-01

    AMG 102 is a fully human monoclonal antibody that selectively targets and neutralizes hepatocyte growth factor/scatter factor (HGF/SF). A detailed biochemical and functional characterization of AMG 102 was done to support its clinical development for the treatment of cancers dependent on signaling through the HGF/SF:c-Met pathway. In competitive equilibrium binding experiments, AMG 102 bound to human and cynomolgus monkey HGF with affinities of approximately 19 pmol/L and 41 pmol/L, respectively. However, AMG 102 did not detect mouse or rabbit HGF on immunoblots. Immunoprecipitation experiments showed that AMG 102 preferentially bound to the mature, active form of HGF, and incubation of AMG 102/HGF complexes with kallikrein protease indicated that AMG 102 had no apparent effect on proteolytic processing of the inactive HGF precursor. AMG 102 inhibited human and cynomolgus monkey HGF-induced c-Met autophosphorylation in PC3 cells with IC(50) values of 0.12 nmol/L and 0.24 nmol/L, respectively. AMG 102 also inhibited cynomolgus monkey HGF-induced migration of human MDA-MB-435 cells but not rat HGF-induced migration of mouse 4T1 cells. Epitope-mapping studies of recombinant HGF molecules comprising human/mouse chimeras and human-to-mouse amino acid substitutions showed that amino acid residues near the NH(2)-terminus of the beta-chain are critical for AMG 102 binding. Bound AMG 102 protected one trypsin protease cleavage site near the NH(2)-terminus of the beta-chain of human HGF, further substantiating the importance of this region for AMG 102 binding. Currently, AMG 102 is in phase II clinical trials in a variety of solid tumor indications. Mol Cancer Ther; 9(2); 400-9.

  8. DIFFERENTIAL BINDING OF HUMAN INTERLEUKIN-1 (IL-1) RECEPTOR ANTAGONIST TO NATURAL AND RECOMBINANT SOLUBLE AND CELLULAR IL-1 TYPE-I RECEPTORS

    DEFF Research Database (Denmark)

    Svenson, Morten; Nedergaard, Susanne; Heegaard, Peter M. H.

    1995-01-01

    electrophoresis in the presence of sodium dodecylsulfate, ligand binding interference analyses, N-glycosidase treatment, concanavalin A affinity chromatography, and with the use of monoclonal antibodies (mAb) to human recombinant IL-1ra. We also evaluated the binding of IL-1ra to cellular IL-1RI on MRC5...

  9. Quantitation of soluble aggregates in recombinant monoclonal antibody cell culture by pH-gradient protein A chromatography.

    Science.gov (United States)

    Pan, Hai; Chen, Ken; Pulisic, Matt; Apostol, Izydor; Huang, Gang

    2009-05-15

    Monoclonal antibodies (mAbs) produced from mammalian cell culture may contain significant amounts of dimers and higher order aggregates. Quantitation of soluble aggregates in the cell culture is time-consuming and labor-intensive, usually involving a purification step to remove the impurities that interfere with the subsequent size exclusion chromatography (SEC) analysis. We have developed a novel pH-gradient protein A chromatography for rapid, non-size based separation of the aggregates in mAb cell culture samples. Our results demonstrate that this method has excellent correlation with SEC and can be applied to both human immunoglobulin gamma 1 (IgG1) and IgG2 antibodies. This approach can be useful in the quantitation of soluble aggregates in crude cell culture samples.

  10. Identification of a human monoclonal antibody to replace equine diphtheria antitoxin for treatment of diphtheria intoxication.

    Science.gov (United States)

    Sevigny, Leila M; Booth, Brian J; Rowley, Kirk J; Leav, Brett A; Cheslock, Peter S; Garrity, Kerry A; Sloan, Susan E; Thomas, William; Babcock, Gregory J; Wang, Yang

    2013-11-01

    Diphtheria antitoxin (DAT) has been the cornerstone of the treatment of Corynebacterium diphtheriae infection for more than 100 years. Although the global incidence of diphtheria has declined steadily over the last quarter of the 20th century, the disease remains endemic in many parts of the world, and significant outbreaks still occur. DAT is an equine polyclonal antibody that is not commercially available in the United States and is in short supply globally. A safer, more readily available alternative to DAT would be desirable. In the current study, we obtained human monoclonal antibodies (hMAbs) directly from antibody-secreting cells in the circulation of immunized human volunteers. We isolated a panel of diverse hMAbs that recognized diphtheria toxoid, as well as a variety of recombinant protein fragments of diphtheria toxin. Forty-five unique hMAbs were tested for neutralization of diphtheria toxin in in vitro cytotoxicity assays with a 50% effective concentration of 0.65 ng/ml for the lead candidate hMAb, 315C4. In addition, 25 μg of 315C4 completely protected guinea pigs from intoxication in an in vivo lethality model, yielding an estimated relative potency of 64 IU/mg. In comparison, 1.6 IU of DAT was necessary for full protection from morbidity and mortality in this model. We further established that our lead candidate hMAb binds to the receptor-binding domain of diphtheria toxin and physically blocks the toxin from binding to the putative receptor, heparin-binding epidermal growth factor-like growth factor. The discovery of a specific and potent human neutralizing antibody against diphtheria toxin holds promise as a potential therapeutic.

  11. Characterization of a human monoclonal antibody against Shiga toxin 2 expressed in Chinese hamster ovary cells.

    Science.gov (United States)

    Akiyoshi, D E; Rich, C M; O'Sullivan-Murphy, S; Richard, L; Dilo, J; Donohue-Rolfe, A; Sheoran, A S; Chapman-Bonofiglio, S; Tzipori, S

    2005-07-01

    Shiga toxin-producing Escherichia coli infections can often lead to the development of hemolytic-uremic syndrome (HUS) in a small percentage of infected humans. Patients with HUS receive only supportive treatment as the benefit of antibiotic therapy remains uncertain. We have previously reported the generation and preclinical evaluation of neutralizing human monoclonal antibodies (HuMAbs) against the Shiga toxins (Stx). In this paper, we describe the expression in Chinese hamster ovary (CHO) cells of 5C12 HuMAb, which is directed against the A subunit of Stx2. The cDNAs of the light and heavy chain immunoglobulin (Ig) variable regions of 5C12 HuMAb were isolated and cloned into an expression vector containing human IgG1 constant regions. The vector was transfected into CHO cells, and transfectants secreting Stx2-specific antibody were screened by an Stx2-specific enzyme-linked immunosorbent assay. The CHO-produced recombinant 5C12 (r5C12) showed similar specificity and binding affinity to Stx2 as the parent hybridoma-produced 5C12. More significantly, the r5C12 displayed the same neutralizing activity as the parent 5C12 in vitro and in vivo. In the mouse toxicity model, both antibodies significantly and equally prolonged survival at a dose of 0.312 microg/mouse. The data showed that since r5C12, produced in CHO cells, was equally effective as the parent 5C12, it is our choice candidate as a potential prophylactic or therapeutic agent against hemolytic-uremic syndrome.

  12. High-yield production of a human monoclonal IgG by rhizosecretion in hydroponic tobacco cultures.

    Science.gov (United States)

    Madeira, Luisa M; Szeto, Tim H; Henquet, Maurice; Raven, Nicole; Runions, John; Huddleston, Jon; Garrard, Ian; Drake, Pascal M W; Ma, Julian K-C

    2016-02-01

    Rhizosecretion of recombinant pharmaceuticals from in vitro hydroponic transgenic plant cultures is a simple, low cost, reproducible and controllable production method. Here, we demonstrate the application and adaptation of this manufacturing platform to a human antivitronectin IgG1 monoclonal antibody (mAb) called M12. The rationale for specific growth medium additives was established by phenotypic analysis of root structure and by LC-ESI-MS/MS profiling of the total protein content profile of the hydroponic medium. Through a combination of optimization approaches, mAb yields in hydroponic medium reached 46 μg/mL in 1 week, the highest figure reported for a recombinant mAb in a plant secretion-based system to date. The rhizosecretome was determined to contain 104 proteins, with the mAb heavy and light chains the most abundant. This enabled evaluation of a simple, scalable extraction and purification protocol and demonstration that only minimal processing was necessary prior to protein A affinity chromatography. MALDI-TOF MS revealed that purified mAb contained predominantly complex-type plant N-glycans, in three major glycoforms. The binding of M12 purified from hydroponic medium to vitronectin was comparable to its Chinese hamster ovary (CHO)-derived counterpart. This study demonstrates that in vitro hydroponic cultivation coupled with recombinant protein rhizosecretion can be a practical, low-cost production platform for monoclonal antibodies. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  13. Antiproliferative activity of recombinant human interferon-λ2 ...

    African Journals Online (AJOL)

    Jane

    2011-07-20

    Jul 20, 2011 ... This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector.

  14. Biophysical characterisation of GlycoPEGylated recombinant human factor VIIa

    DEFF Research Database (Denmark)

    Plesner, Bitten; Westh, Peter; Nielsen, Anders D.

    2011-01-01

    The effects of GlycoPEGylation on the structural, kinetic and thermal stability of recombinant human FVIIa were investigated using rFVIIa and linear 10 kDa and branched 40 kDa GlycoPEGylated® recombinant human FVIIa derivatives. The secondary and tertiary structure of rFVIIa measured by circular...

  15. Antiproliferative activity of recombinant human interferon-λ2 ...

    African Journals Online (AJOL)

    This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector pIZT/V5-His harboring the ...

  16. Feasibility of a recombinant human apolipoprotein E reference material

    NARCIS (Netherlands)

    Schiele, F.; Barbier, A.; Visvikis, A.; Aggerbeck, L.; Rosseneu, M.; Havekes, L.; Huttinger, M.; Profilis, C.; Siest, G.

    1998-01-01

    The aim of this work was to prepare a recombinant apo E material and to determine its suitability as a reference material. We produced human apo E3 using recombinant DNA technology. The cDNA of human apo E3 was cloned in the pARHS bacterial expression vector and used to transfect E. Coli BL21 (DE3)

  17. Human monoclonal antibody combination against SARS coronavirus: synergy and coverage of escape mutants

    NARCIS (Netherlands)

    ter Meulen, Jan; van den Brink, Edward N.; Poon, Leo L. M.; Marissen, Wilfred E.; Leung, Cynthia S. W.; Cox, Freek; Cheung, Chung Y.; Bakker, Arjen Q.; Bogaards, Johannes A.; van Deventer, Els; Preiser, Wolfgang; Doerr, Hans Wilhelm; Chow, Vincent T.; de Kruif, John; Peiris, Joseph S. M.; Goudsmit, Jaap

    2006-01-01

    BACKGROUND: Experimental animal data show that protection against severe acute respiratory syndrome coronavirus (SARS-CoV) infection with human monoclonal antibodies (mAbs) is feasible. For an effective immune prophylaxis in humans, broad coverage of different strains of SARS-CoV and control of

  18. 77 FR 5036 - Prospective Grant of Exclusive License: The Development of Human Anti-Mesothelin Monoclonal...

    Science.gov (United States)

    2012-02-01

    ... the treatment of pancreatic cancer, ovarian cancer, lung cancer, mesothelioma, and stomach/gastric... the treatment of mesothelin-expressing cancers, including mesothelioma, lung cancer, stomach/gastric... Human Anti-Mesothelin Monoclonal Antibodies for the Treatment of Human Cancers AGENCY: National...

  19. Efficient enrichment of high-producing recombinant Chinese hamster ovary cells for monoclonal antibody by flow cytometry.

    Science.gov (United States)

    Okumura, Takeshi; Masuda, Kenji; Watanabe, Kazuhiko; Miyadai, Kenji; Nonaka, Koichi; Yabuta, Masayuki; Omasa, Takeshi

    2015-09-01

    To screen a high-producing recombinant Chinese hamster ovary (CHO) cell from transfected cells is generally laborious and time-consuming. We developed an efficient enrichment strategy for high-producing cell screening using flow cytometry (FCM). A stable pool that had possibly shown a huge variety of monoclonal antibody (mAb) expression levels was prepared by transfection of an expression vector for mAb production to a CHO cell. To enrich high-producing cells derived from a stable pool stained with a fluorescent-labeled antibody that binds to mAb presented on the cell surface, we set the cell size and intracellular density gates based on forward scatter (FSC) and side scatter (SSC), and collected the brightest 5% of fluorescein isothiocyanate (FITC)-positive cells from each group by FCM. The final product concentration in a fed-batch culture of cells sorted without FSC and SSC gates was 1.2-1.3-times higher than that of unsorted cells, whereas that of cells gated by FSC and SSC was 3.4-4.7-fold higher than unsorted cells. Surprisingly, the fraction with the highest final product concentration indicated the smallest value of FSC and SSC, and the middle value of fluorescence intensity among all fractionated cells. Our results showed that our new screening strategy by FCM based on FSC and SSC gates could achieve an efficient enrichment of high-producing cells with the smallest value of FSC and SSC. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Systemic lupus erythematosus: molecular cloning of several recombinant DNase monoclonal kappa light chains with different catalytic properties.

    Science.gov (United States)

    Botvinovskaya, Alina V; Kostrikina, Irina A; Buneva, Valentina N; Nevinsky, Georgy A

    2013-10-01

    An immunoglobulin light chain phagemid library derived from peripheral blood lymphocytes of three patients with systemic lupus erythematosus was used. Phage particles displaying DNA binding light chains were isolated by affinity chromatography on DNA-cellulose, and the fraction eluted by an acidic buffer (pH 2.6) was used for preparation of individual monoclonal light chains (MLChs, 28 kDa). Thirty three of 687 individual colonies obtained were randomly chosen for study of MLCh DNase activity. Nineteen of 33 clones contained MLChs with DNase activity. Four preparations of MLChs were expressed in Escherichia coli in soluble form, purified by metal chelating chromatography followed by gel filtration, and studied in detail. Detection of DNase activity after SDS-PAGE in a gel containing DNA demonstrated that the four MLChs are not contaminated by canonical DNases. The MLChs demonstrated one or two pH optima. They were inactive after the dialysis against ethylenediaminetetraacetic acid but could be activated by several externally added metal ions; the ratio of relative activity in the presence of Mg(2+) , Mn(2+) , Ni(2+) , Ca(2+) , Zn(2+) , and Co(2+) was individual for each MLCh preparation. K(+) and Na(+) inhibited the DNase activity of various MLChs at different concentrations. Hydrolysis of DNA by all four MLCh was saturable and consistent with Michaelis-Menten kinetics. These clones are the first examples of recombinant MLChs possessing high affinity for DNA (Km  = 3-9 nM) and demonstrating high kcat values (3.4-6.9 min(-1) ). These observations suggest that the systemic lupus erythematosus light chain repertoire can serve as a source of new types of DNases. Copyright © 2013 John Wiley & Sons, Ltd.

  1. Immunoreactivity of skate electrocytes towards monoclonal antibodies against human dystrophin and dystrophin-related (DMDL) protein.

    Science.gov (United States)

    Dowdall, M J; Ellis, J M; Nguyen thi Man; Morris, G E

    1992-04-13

    Monoclonal antibodies against human dystrophin have been used to demonstrate the existence of a dystrophin-like protein in the electrocytes of skate electric organ. This protein is also present in skate muscle and resembles that found in Torpedo electric organ. Monoclonal antibodies against a human autosomal homologue of dystrophin (DMDL protein) did not detect a similar protein in skate or Torpedo. Immunocytochemical staining of the innervated and non-innervated faces of the electrocyte membrane was obtained using the anti-dystrophin antibodies only.

  2. Characterization of pathogenic human monoclonal autoantibodies against GM-CSF.

    Science.gov (United States)

    Wang, Yanni; Thomson, Christy A; Allan, Lenka L; Jackson, Linda M; Olson, Melanie; Hercus, Timothy R; Nero, Tracy L; Turner, Amanda; Parker, Michael W; Lopez, Angel L; Waddell, Thomas K; Anderson, Gary P; Hamilton, John A; Schrader, John W

    2013-05-07

    The origin of pathogenic autoantibodies remains unknown. Idiopathic pulmonary alveolar proteinosis is caused by autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). We generated 19 monoclonal autoantibodies against GM-CSF from six patients with idiopathic pulmonary alveolar proteinosis. The autoantibodies used multiple V genes, excluding preferred V-gene use as an etiology, and targeted at least four nonoverlapping epitopes on GM-CSF, suggesting that GM-CSF is driving the autoantibodies and not a B-cell epitope on a pathogen cross-reacting with GM-CSF. The number of somatic mutations in the autoantibodies suggests that the memory B cells have been helped by T cells and re-entered germinal centers. All autoantibodies neutralized GM-CSF bioactivity, with general correlations to affinity and off-rate. The binding of certain autoantibodies was changed by point mutations in GM-CSF that reduced binding to the GM-CSF receptor. Those monoclonal autoantibodies that potently neutralize GM-CSF may be useful in treating inflammatory disease, such as rheumatoid arthritis and multiple sclerosis, cancer, and pain.

  3. Naturalizing activity and safety of human monoclonal antibodies against of hepatitis C virus.

    Science.gov (United States)

    Abelhafez, Tawfeek H; Tabll, Ashraf A; El-Awady, Mostafa K; Mashaly, Mohammad M; El Shenawy, Reem; El-Abd, Yasmine S; Shaker, Maysa H; Abdel Malak, Camelia A

    2017-09-29

    Assessment of neutralizing activity of the human monoclonal antibodies against HCV and also study its safety in experimental small animals (Swiss mice). Assessment of neutralizing activity of the human monoclonal antibodies against HCV envelope regions (E1, E2) by two methods (by HCV cc infectious system and by using positive HCV positive serum as source of HCV particles (neutralizing assay 2). Dot ELISA were used to study the activity of the generated antibodies. We tested the safety and toxicity of the generated human antibodies by assessment the changes in biochemistry of liver function tests and changes in kidney function test, Complete blood counts (CBC) and study the pathological changes with different concentration of purified human antibodies. Human Abs # 5 & 11 showed neutralizing activity by (neutralizing assay 2) but were not neutralizing by HCV cc assay. Human Abs # 12 & 15 showed neutralizing activity by two methods i.e our generated human antibodies Abs# 5 &11 & 12 & 15 were neutralizing for HCV genotype 4a and Abs # 12 & 15 were neutralizing for HCV genotypes 4a and 2a. Liver and kidney functions and CBC results indicated that doses of 10 μg, 100 μg were safe. The histopathological results indicated that the dose of 10 μg of purified human monoclonal antibodies per mouse body weight was safe. The generated human monoclonal antibodies can be used to develop a potent immunotherapy that can be administrated for the post-transplantation patients to prevent the recurrence of HCV infection. Also, the monoclonal antibodies can be used to develop a vaccine against HCV.

  4. SPAM-8, a mouse-human heteromyeloma fusion partner in the production of human monoclonal antibodies. Establishment of a human monoclonal antibody against cytomegalovirus.

    Science.gov (United States)

    Gustafsson, B; Jondal, M; Sundqvist, V A

    1991-01-01

    A heteromyeloma (mouse x human) cell line (SPAM-8) was produced by fusing mouse myeloma cells (SP2/0) with human peripheral blood lymphocytes. The cells were sensitive to aminopterin and resistant to ouabain. The cells showed a doubling time of about 19 hours and a cloning efficiency of 0.8 cells/well (to obtain growth in 50% of wells seeded) using mouse thymocytes as feeder cells. The number of chromosomes was about 86 and 1% of the total DNA was of human origin. Fusion of SPAM-8 cells with lymphocytes prepared from human spleens resulted in approximately one hybridoma per 10(5) seeded lymphocytes. A trioma (human x [mouse x human]) cell line was established by fusing cells of an Epstein-Barr virus-transformed B cell line with SPAM-8 cells. The trioma cells produced antibodies (IgG1, K) against cytomegalovirus, in a concentration of 7 micrograms/ml in spent medium, over a period of six months of continuous culture. The results obtained indicate that the heteromyeloma SPAM-8 may be used as a fusion partner in the production of human monoclonal antibodies.

  5. Development of a novel anti-human aspartyl-(asparaginyl) β-hydroxylase monoclonal antibody with diagnostic and therapeutic potential.

    Science.gov (United States)

    Huyan, Ting; Li, Qi; Dong, Dan-Dan; Yang, Hui; Xue, Xiao-Ping; Huang, Qing-Sheng

    2017-03-01

    Human aspartyl-(asparaginyl)-β-hydroxylase (HAAH) has recently been the subject of several studies, as it was previously observed to be overexpressed in numerous types of carcinoma cells and tissues in patient tumor samples. HAAH has been implicated in tumor invasion and metastasis, indicating that it may be an important target and biomarker for tumor diagnosis and treatment. However, the immunological tools currently available for the study of this protein, including monoclonal antibodies, are limited, as is the present knowledge regarding the role of HAAH in tumor therapy and diagnosis. In the present study, a recombinant C-terminal domain of HAAH was expressed in Pichia pastoris and a novel monoclonal antibody (mAb) targeting HAAH (HAAH-C) was constructed. Immunofluorescence and antibody-dependent cellular cytotoxicity (ADCC) assays were used to demonstrate the specificity and ADCC activity of this antibody. The results demonstrated that this anti-C-terminal HAAH mAB, in combination with an existing anti-N terminal HAAH mAb, exhibited a high response to native HAAH from carcinoma cell culture supernatant, as measured with a double antibody sandwich enzyme-linked immunosorbent assay. This validated novel mAB-HAAH-C may prompt further studies into the underlying mechanisms of HAAH, and the exploration of its potential in tumor diagnosis and therapy.

  6. N-terminal or signal peptide sequence engineering prevents truncation of human monoclonal antibody light chains.

    Science.gov (United States)

    Gibson, S J; Bond, N J; Milne, S; Lewis, A; Sheriff, A; Pettman, G; Pradhan, R; Higazi, D R; Hatton, D

    2017-09-01

    Monoclonal antibodies (mAbs) contain short N-terminal signal peptides on each individual polypeptide that comprises the mature antibody, targeting them for export from the cell in which they are produced. The signal peptide is cleaved from each heavy chain (Hc) and light chain (Lc) polypeptide after translocation to the ER and prior to secretion. This process is generally highly efficient, producing a high proportion of correctly cleaved Hc and Lc polypeptides. However, mis-cleavage of the signal peptide can occur, resulting in truncation or elongation at the N-terminus of the Hc or Lc. This is undesirable for antibody manufacturing as it can impact efficacy and can result in product heterogeneity. Here, we describe a truncated variant of the Lc that was detected during a routine developability assessment of the recombinant human IgG1 MEDI8490 in Chinese hamster ovary cells. We found that the truncation of the Lc was caused due to the use of the murine Hc signal peptide together with a lambda Lc containing an SYE amino acid motif at the N-terminus. This truncation was not caused by mis-processing of the mRNA encoding the Lc and was not dependent on expression platform (transient or stable), the scale of the fed-batch culture or clonal lineage. We further show that using alternative signal peptides or engineering the Lc SYE N-terminal motif prevented the truncation and that this strategy will improve Lc homogeneity of other SYE lambda Lc-containing mAbs. Biotechnol. Bioeng. 2017;114: 1970-1977. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Human Monoclonal Antibodies Targeting Glypican-2 in Neuroblastoma | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    Researchers at the National Cancer Institute’s Laboratory of Molecular Biology (NCI LMB) have developed and isolated several single domain monoclonal human antibodies against GPC2. NCI seeks parties interested in licensing or co-developing GPC2 antibodies and/or conjugates.

  8. A human monoclonal antibody cocktail as a novel component of rabies postexposure prophylaxis

    NARCIS (Netherlands)

    de Kruif, John; Bakker, Alexander B. H.; Marissen, Wilfred E.; Kramer, R. Arjen; Throsby, Mark; Rupprecht, Charles E.; Goudsmit, Jaap

    2007-01-01

    The currently recommended treatment for individuals exposed to rabies virus is the combined administration of rabies vaccine and rabies immune globulin (RIG). This review sets out the criteria used to guide development of a cocktail of human monoclonal antibodies as a replacement for RIG. Using this

  9. Production and characterisation of monoclonal antibodies against native and disassembled human catalase

    NARCIS (Netherlands)

    Wiemer, E. A.; Ofman, R.; Middelkoop, E.; de Boer, M.; Wanders, R. J.; Tager, J. M.

    1992-01-01

    Catalase isolated from human erythrocytes was used to immunise mice, in order to generate hybridomas producing specific monoclonal antibodies to the enzyme. Hybridomas secreting anti-(catalase) antibodies were identified by a modified enzyme-linked immunosorbent assay (ELISA) using either

  10. 76 FR 63317 - Prospective Grant of Exclusive License: The Development of Human Anti-Mesothelin Monoclonal...

    Science.gov (United States)

    2011-10-12

    ... therapy for the treatment of pancreatic cancer, ovarian cancer, lung cancer, mesothelioma, and stomach... Treatment of Human Cancers AGENCY: National Institutes of Health, Public Health Service, HHS. ACTION: Notice... concerns a monoclonal antibody and methods of using the antibody for the treatment of mesothelin-expressing...

  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

    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...

  12. Absence of the TAP2 human recombination hotspot in chimpanzees.

    Directory of Open Access Journals (Sweden)

    Susan E Ptak

    2004-06-01

    Full Text Available Recent experiments using sperm typing have demonstrated that, in several regions of the human genome, recombination does not occur uniformly but instead is concentrated in "hotspots" of 1-2 kb. Moreover, the crossover asymmetry observed in a subset of these has led to the suggestion that hotspots may be short-lived on an evolutionary time scale. To test this possibility, we focused on a region known to contain a recombination hotspot in humans, TAP2, and asked whether chimpanzees, the closest living evolutionary relatives of humans, harbor a hotspot in a similar location. Specifically, we used a new statistical approach to estimate recombination rate variation from patterns of linkage disequilibrium in a sample of 24 western chimpanzees (Pan troglodytes verus. This method has been shown to produce reliable results on simulated data and on human data from the TAP2 region. Strikingly, however, it finds very little support for recombination rate variation at TAP2 in the western chimpanzee data. Moreover, simulations suggest that there should be stronger support if there were a hotspot similar to the one characterized in humans. Thus, it appears that the human TAP2 recombination hotspot is not shared by western chimpanzees. These findings demonstrate that fine-scale recombination rates can change between very closely related species and raise the possibility that rates differ among human populations, with important implications for linkage-disequilibrium based association studies.

  13. Recombinant human erythropoietin in sports: a review

    Directory of Open Access Journals (Sweden)

    Rafael Maia de Almeida Bento

    2003-06-01

    Full Text Available Erythropoietin is an endogenous hormone of glicoproteic nature secreted by the kidneys and is the main regulator of the erythropoiesis. An alteration in its production generates a disturbance in the plasmatic concentration giving rise to several types of pathologies related to the hematopoietic system. The recombinant forms of erythropoietin have indiscriminately been used by athletes, mainly in endurance sports, by increasing the erythrocytes concentration, generating a better delivery of oxygen to the muscle tissue. The administration of recombinant erythropoietin was prohibited by the International Olympic Committee and its use considered as doping. This review has the intention to describe the physical, biological and pharmacokinetic properties of the endogenous erythropoietin, as well as its recombinant form, describing also its use in sports and the process of searching methodologies for its detection in doping control.

  14. Purification of human recombinant granulocyte colony stimulating ...

    African Journals Online (AJOL)

    In Escherichia coli, recombinant proteins were produced either as three dimensionally folded forms or as unfolded forms, inclusion body (IB). The formation of IB was a frequent consequence of high-level protein production and inadequacy of folding agents namely chaperones in the cytoplasm. The structure of the protein in ...

  15. Use of a monoclonal antibody to distinguish between precursor and mature forms of human lysosomal alpha-glucosidase

    NARCIS (Netherlands)

    Oude Elferink, R. P.; Strijland, A.; Surya, I.; Brouwer-Kelder, E. M.; Kroos, M.; Hilkens, J.; Hilgers, J.; Reuser, A. J.; Tager, J. M.

    1984-01-01

    The maturation of lysosomal alpha-glucosidase in cultured human skin fibroblasts was studied using a monoclonal antibody that distinguishes between the precursor and mature forms of the enzyme. Monoclonal antibodies against alpha-glucosidase isolated from placenta were produced by the hybridoma

  16. Monoclonal antibodies reacting with multiple epitopes on the human insulin receptor.

    OpenAIRE

    Soos, M A; Siddle, K; Baron, M D; Heward, J M; Luzio, J P; Bellatin, J; Lennox, E S

    1986-01-01

    Monoclonal antibodies for the human insulin receptor were produced following immunization of mice with IM-9 lymphocytes and/or purified placental receptor. Four separate fusions yielded 28 antibodies, all of which reacted with receptor from human placenta, liver and IM-9 cells. Some antibodies cross-reacted to varying degrees with receptor from rabbit, cow, pig and sheep, but none reacted with rat receptor. At least 10 distinct epitopes were recognized as indicated by species specificity and ...

  17. Humanization and Characterization of an Anti-Human TNF-α Murine Monoclonal Antibody

    Science.gov (United States)

    Chiu, Wei-Chun; Lai, Ya-Ping; Chou, Min-Yuan

    2011-01-01

    A murine monoclonal antibody, m357, showing the highly neutralizing activities for human tumor necrosis factor (TNF-α) was chosen to be humanized by a variable domain resurfacing approach. The non-conserved surface residues in the framework regions of both the heavy and light chain variable regions were identified via a molecular modeling of m357 built by computer-assisted homology modeling. By replacing these critical surface residues with the human counterparts, a humanized version, h357, was generated. The humanized h357 IgG1 was then stably expressed in a mammalian cell line and the purified antibody maintained the high antigen binding affinity as compared with the parental m357 based on a soluble TNF-α neutralization bioassay. Furthermore, h357 IgG1 possesses the ability to mediate antibody-dependent cell-mediated cytotoxicity and complement dependent cytotoxicity upon binding to cells bearing the transmembrane form of TNF-α. In a mouse model of collagen antibody-induced arthritis, h357 IgG significantly inhibited disease progression by intra-peritoneal injection of 50 µg/mouse once-daily for 9 consecutive days. These results provided a basis for the development of h357 IgG as therapeutic use. PMID:21305012

  18. Humanized versus murine anti-human epidermal growth factor receptor monoclonal antibodies for immunoscintigraphic studies

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Alejo A. Morales; Duconge, Jorge; Alvarez-Ruiz, Daniel; Becquer-Viart, Maria de Los Angeles; Nunez-Gandolff, Gilda; Fernandez, Eduardo; Caballero-Torres, Idania; Iznaga-Escobar, Normando

    2000-02-01

    The anti-human epidermal growth factor receptor (EGF-R) humanized antibody h-R3 (IgG{sub 1}), which binds to an extracellular domain of EGF-R, was used to evaluate the biodistribution on nude mice xenografted with A431 epidermoid carcinoma cell line. Results are compared with its murine version ior egf/r3 monoclonal antibody (mAb). Twenty-one athymic female 4NMRI nu/nu mice were injected intravenously with 10 {mu}g/100 {mu}Ci of {sup 99m}Tc-labeled mAbs. The mAb ior C5 that recognizes an antigen expressed preferentially on the surface of malignant and cytoplasm of normal colorectal cells was used as negative control. Immunoreactivity of {sup 99m}Tc-labeled mAbs was measured by enzyme linked immunosorbent assay on A431 cell line and the immunoreactive fractions determined by Lindmo method. Among all organs significant accumulation was found in tumor (6.14{+-}2.50 %ID/g, 5.06{+-}2.61 %ID/g for murine and humanized mAbs, respectively) 4 h after injection. The immunoreactive fractions were found to be 0.88 and 0.81 for murine and humanized mAb, respectively. Thus, we expect better results using the humanized mAb h-R3 for diagnostic immunoscintigraphy.

  19. Isolation, production and characterization of fully human monoclonal antibodies directed to Plasmodium falciparum MSP10.

    Science.gov (United States)

    Maskus, Dominika J; Bethke, Susanne; Seidel, Melanie; Kapelski, Stephanie; Addai-Mensah, Otchere; Boes, Alexander; Edgü, Güven; Spiegel, Holger; Reimann, Andreas; Fischer, Rainer; Barth, Stefan; Klockenbring, Torsten; Fendel, Rolf

    2015-07-16

    Semi-immunity against the malaria parasite is defined by a protection against clinical episodes of malaria and is partially mediated by a repertoire of inhibitory antibodies directed against the blood stage of Plasmodium falciparum, in particular against surface proteins of merozoites, the invasive form of the parasite. Such antibodies may be used for preventive or therapeutic treatment of P. falciparum malaria. Here, the isolation and characterization of novel human monoclonal antibodies (humAbs) for such applications is described. B lymphocytes had been selected by flow cytometry for specificity against merozoite surface proteins, including the merozoite surface protein 10 (MSP10). After Epstein-Barr virus (EBV) transformation and identification of promising resulting lymphoblastoid cell lines (LCLs), human immunoglobulin heavy and light chain variable regions (Vh or Vl regions) were secured, cloned into plant expression vectors and transiently produced in Nicotiana benthamiana in the context of human full-size IgG1:κ. The specificity and the affinity of the generated antibodies were assessed by ELISA, dotblot and surface plasmon resonance (SPR) spectroscopy. The growth inhibitory activity was evaluated based on growth inhibition assays (GIAs) using the parasite strain 3D7A. Supernatants from two LCLs, 5E8 and 5F6, showed reactivity against the second (5E8) or first (5F6) epidermal growth factor (EGF)-like domain of MSP10. The isolated V regions were recombinantly expressed in their natural pairing as well as in combination with each other. The resulting recombinant humAbs showed affinities of 9.27 × 10(-7) M [humAb10.1 (H5F6:κ5E8)], 5.46 × 10(-9) M [humAb10.2 (H5F6:κ5F6)] and 4.34 × 10(-9) M [humAb10.3 (H5E8:κ5E8)]. In GIAs, these antibodies exhibited EC50 values of 4.1 mg/ml [95% confidence interval (CI) 2.6-6.6 mg/ml], 6.9 mg/ml (CI 5.5-8.6 mg/ml) and 9.5 mg/ml (CI 5.5-16.4 mg/ml), respectively. This report describes a platform for the isolation of

  20. An Approach to Breast Cancer Immunotherapy: The Apoptotic Activity of Recombinant Anti-Interleukin-6 Monoclonal Antibodies in Intact Tumour Microenvironment of Breast Carcinoma.

    Science.gov (United States)

    Abou-Shousha, S; Moaaz, M; Sheta, M; Motawea, M A

    2016-06-01

    Current work is one of our comprehensive preclinical studies, a new approach to breast cancer (BC) immunotherapy through induction of tumour cell apoptosis. Tumour growth is not just a result of uncontrolled cell proliferation but also of reduced apoptosis. High levels of interleukin-6 (IL-6) are associated with metastatic BC and correlated with poor survival as it promotes growth of tumour-initiating cells during early tumorigenesis protecting these cells from apoptosis. Therefore, this study aims at investigating the potential of anti-IL-6 monoclonal antibodies to suppress IL-6 proliferative/anti-apoptotic activities in intact tumour microenvironment of BC. Fresh sterile tumour and normal breast tissue specimens were taken from 50 female Egyptian patients with BC undergoing radical mastectomy. A unique tissue culture system designed to provide cells of each intact tumour/normal tissue sample with its proper microenvironment either supplemented or not with anti-IL-6 monoclonal antibodies. To evaluate the apoptotic activity of anti-IL-6 as a novel candidate for BC treatment strategy, we compared its effects with those obtained using tumour necrosis-related apoptosis-inducing ligand TRAIL as an established apoptotic agent. Our results revealed that levels of either anti-IL-6- or TRAIL-induced apoptosis in the tumour or normal tissue cultures were significantly higher than those in their corresponding untreated ones (P < 0.001). No statistically significant differences have been found between apoptosis levels induced by anti-IL-6 monoclonal antibodies and those induced by TRAIL. Recombinant anti-IL-6 monoclonal antibodies could represent a novel effective element of immunotherapeutic treatment strategy for BC. The selectivity and anti-apoptotic potential of anti-IL-6 is highly hopeful in IL-6- abundant BC tumour microenvironment. © 2016 The Foundation for the Scandinavian Journal of Immunology.

  1. PRODUCTION OF A HUMAN RECOMBINANT ANTIBODY AGAINST SEROTYPE A CANDIDA ALBICANS

    Directory of Open Access Journals (Sweden)

    A A. Jafari

    2005-07-01

    Full Text Available After using 3 different generations of antibodies including human and non-human hyperimmune sera, monoclonal antibodies and chimeric antibodies, more recently a newer approach has been developed in which the antibody genes are cloned directly from a patient peripheral B-lymphocytes and expressed in a host like E. coli. In this study the Candida albicans serotype A (NCTC 3153 mannan was purified using a modified Fehling method and used for selection of human recombinant antibody from a C. albicans phage antibody library. After four rounds of affinity selecting (panning, 2 predominant clones were chosen by DNA fingerprinting and ELISA. A 248 amino acid DNA fragment coding for anti-C. albicans mannan scFv was sequenced and cloned in a pBAD-TOPO cloning vector to produce a soluble and phage free antibody. The analysis of antibody sequences by V base Index (DNAPLOT confirmed the human antibody origin with the VH4 family in V segment of heavy variable chain and VL3 (Lambda 3 in J segment of the light variable chain. This antibody fragment was purified using immobilized metal affinity chromatography and inmmunoblotted as a 31kDa recombinant protein.

  2. A monoclonal antibody defining human B cell differentiation antigen (HLB-1 antigen).

    Science.gov (United States)

    Kasai, K; Koshiba, H; Ishii, Y; Kikuchi, K

    1983-01-01

    A new monoclonal antibody specific for human B cell differentiation antigen (HLB-1) is produced by a hybridoma established by fusion of splenocytes of mice immunized with the Epstein-Barr virus (EBV)-transformed peripheral B cell line, RPMI-8057. This monoclonal, antibody designated anti-HLB-1 monoclonal antibody (anti-HLB-1), reacted with surface immunoglobulin (sIg)-positive B cells of normal peripheral blood and lymphoid tissues and sIg-positive leukemic cells. The cells of T cell leukemia, non-T non-B acute lymphoblastic leukemia (ALL) and nonlymphoid leukemia were HLB-1 negative. These data were further confirmed by studying a panel of cultured human hematopoietic cell lines. Anti-HLB-1 reacted with B cell lines derived from pre-B, Burkitt's lymphoma, B cell type ALL and EBV-transformed peripheral B cells. Anti-HLB-1 was reactive with only one of three human myeloma cell lines, and with none of the T cell, myeloid and non-T non-B ALL cell lines. This newly defined HLB-1 antigen is different from other conventional human B cell markers such as sIg, Ia antigens, and receptors for the Fc portion of Ig and complement C3.

  3. Evidence of recombination within human alpha-papillomavirus

    Directory of Open Access Journals (Sweden)

    Carvajal-Rodríguez Antonio

    2007-03-01

    Full Text Available Abstract Background Human papillomavirus (HPV has a causal role in cervical cancer with almost half a million new cases occurring each year. Presence of the carcinogenic HPV is necessary for the development of the invasive carcinoma of the genital tract. Therefore, persistent infection with carcinogenic HPV causes virtually all cervical cancers. Some aspects of the molecular evolution of this virus, as the putative importance of recombination in its evolutionary history, are an opened current question. In addition, recombination could also be a significant issue nowadays since the frequency of co-infection with more than one HPV type is not a rare event and, thus, new recombinant types could be currently being generated. Results We have used human alpha-PV sequences from the public database at Los Alamos National Laboratory to report evidence that recombination may exist in this virus. A model-based population genetic approach was used to infer the recombination signal from the HPV DNA sequences grouped attending to phylogenetic and epidemiological information, as well as to clinical manifestations. Our results agree with recently published ones that use a different methodology to detect recombination associated to the gene L2. In addition, we have detected significant recombination signal in the genes E6, E7, L2 and L1 at different groups, and importantly within the high-risk type HPV16. The method used has recently been shown to be one of the most powerful and reliable procedures to detect the recombination signal. Conclusion We provide new support to the recent evidence of recombination in HPV. Additionally, we performed the recombination estimation assuming the best-fit model of nucleotide substitution and rate variation among sites, of the HPV DNA sequence sets. We found that the gene with recombination in most of the groups is L2 but the highest values were detected in L1 and E6. Gene E7 was recombinant only within the HPV16 type. The

  4. Generation of human antigen-specific monoclonal IgM antibodies using vaccinated "human immune system" mice

    NARCIS (Netherlands)

    Becker, P.D.; Legrand, N.; van Geelen, C.M.M.; Noerder, M.; Huntington, N.D.; Lim, A.; Yasuda, E.; Diehl, S.A.; Scheeren, F.A.; Ott, M.; Weijer, K.; Wedemeyer, H.; Di Santo, J.P.; Beaumont, T.; Guzman, C.A.; Spits, H.

    2010-01-01

    Passive transfer of antibodies not only provides immediate short-term protection against disease, but also can be exploited as a therapeutic tool. However, the 'humanization' of murine monoclonal antibodies (mAbs) is a time-consuming and expensive process that has the inherent drawback of

  5. Recombinational DNA repair and human disease

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larry H.; Schild, David

    2002-11-30

    We review the genes and proteins related to the homologous recombinational repair (HRR) pathway that are implicated in cancer through either genetic disorders that predispose to cancer through chromosome instability or the occurrence of somatic mutations that contribute to carcinogenesis. Ataxia telangiectasia (AT), Nijmegen breakage syndrome (NBS), and an ataxia-like disorder (ATLD), are chromosome instability disorders that are defective in the ataxia telangiectasia mutated (ATM), NBS, and Mre11 genes, respectively. These genes are critical in maintaining cellular resistance to ionizing radiation (IR), which kills largely by the production of double-strand breaks (DSBs). Bloom syndrome involves a defect in the BLM helicase, which seems to play a role in restarting DNA replication forks that are blocked at lesions, thereby promoting chromosome stability. The Werner syndrome gene (WRN) helicase, another member of the RecQ family like BLM, has very recently been found to help mediate homologous recombination. Fanconi anemia (FA) is a genetically complex chromosomal instability disorder involving seven or more genes, one of which is BRCA2. FA may be at least partially caused by the aberrant production of reactive oxidative species. The breast cancer-associated BRCA1 and BRCA2 proteins are strongly implicated in HRR; BRCA2 associates with Rad51 and appears to regulate its activity. We discuss in detail the phenotypes of the various mutant cell lines and the signaling pathways mediated by the ATM kinase. ATM's phosphorylation targets can be grouped into oxidative stress-mediated transcriptional changes, cell cycle checkpoints, and recombinational repair. We present the DNA damage response pathways by using the DSB as the prototype lesion, whose incorrect repair can initiate and augment karyotypic abnormalities.

  6. Monoclonal antibodies to human hemoglobin S and cell lines for the production thereof

    Science.gov (United States)

    Jensen, Ronald H.; Vanderlaan, Martin; Bigbee, William L.; Stanker, Larry H.; Branscomb, Elbert W.; Grabske, Robert J.

    1988-01-01

    The present invention provides monoclonal antibodies specific to and distinguish between hemoglobin S and hemoglobin A and methods for their production and use. These antibodies are capable of distinguishing between two hemoglobin types which differ from each other by only a single amino acid residue. The antibodies produced according to the present method are useful as immunofluorescent markers to enumerate circulating red blood cells which have the property of altered expression of the hemoglobin gene due to somatic mutation in stem cells. Such a measurement is contemplated as an assay for in vivo cellular somatic mutations in humans. Since the monoclonal antibodies produced in accordance with the instant invention exhibit a high degree of specificity to and greater affinity for hemoglobin S, they are suitable for labeling human red blood cells for flow cytometric detection of hemoglobin genotype.

  7. The monoclonal antibody GRC1 produced against human cornea recognizes a common determinant of collagen.

    Science.gov (United States)

    Lopez Nevot, M A; Cardona, L; Doblaré, E; Muñoz, C; Ruiz-Cabello, F; Garrido, F

    1990-02-01

    The monoclonal antibody GRC1 was obtained by immunizing BALB/c mice with human cornea. Screening was performed by indirect immunofluorescence in cryostatic sections of several tissues: cornea, skin, placenta, hyaline cartilage, blood vessels, and nerves. GRC1 was seen to recognize fibrillar structures in all of these tissues. The pattern of reaction was interstitial and membranous. On cornea, GRC1 reacts definitely with Bowman's membrane and diffusely with the stroma, while on skin it shows strongly positive reactivity with the papillary dermis and with the basement membrane. It also reacts on hyaline cartilage at the periphery of the condrocytic lacunae. These immunohistologic results suggest that GRC1 recognized human collagen. In order to investigate further the subtype of collagen defined by GRC1, an ELISA was performed with purified collagens of several types: I, II, III, IV, and V. The monoclonal antibody GRC1 defines a common determinant in types III, IV, and V.

  8. Antigenic assessment of a recombinant human CD90 protein expressed in prokaryotic expression system.

    Science.gov (United States)

    Yousefi-Rad, Narges; Shokrgozar, Mohammad Ali; Behdani, Mahdi; Moradi-Kalbolandi, Shima; Motamedi-Rad, Mahdieh; Habibi-Anbouhi, Mahdi

    2015-12-01

    Cluster of Differentiation 90 (CD90, Thy-1) has been proposed as one of the most important biomarkers in several cancer cells including cancer stem cells (CSCs). CD90 is considered as a potential normal stem cell and CSCs biomarker and also has been identified in lung cancer stem cells, hepatocellular carcinoma cells and high-grade gliomas. Using eukaryotic host systems involves complex procedures and frequently results in low protein yields. The expression of recombinant proteins in Escherichia coli is comparatively easier than eukaryotic host cells. The potential of large scale production of recombinant protein has made this system an economic production platform. In this study we expressed the extra-membrane domain of human CD90 (exCD90) antigen (Gln15-Cys130) in E. coli expression host cells. The epitope integrity of purified recombinant antigen was confirmed by antibody-antigen interaction using 5E10 anti-CD90 monoclonal antibody and binding study through ELISA and florescent staining of CD90(+) cells in a flow cytometry experiment. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Human-monoclonal-antibody therapy protects nonhuman primates against advanced Lassa fever.

    Science.gov (United States)

    Mire, Chad E; Cross, Robert W; Geisbert, Joan B; Borisevich, Viktoriya; Agans, Krystle N; Deer, Daniel J; Heinrich, Megan L; Rowland, Megan M; Goba, Augustine; Momoh, Mambu; Boisen, Mathew L; Grant, Donald S; Fullah, Mohamed; Khan, Sheik Humarr; Fenton, Karla A; Robinson, James E; Branco, Luis M; Garry, Robert F; Geisbert, Thomas W

    2017-10-01

    There are no approved treatments for Lassa fever, which is endemic to the same regions of West Africa that were recently devastated by Ebola. Here we show that a combination of human monoclonal antibodies that cross-react with the glycoproteins of all four clades of Lassa virus is able to rescue 100% of cynomolgus macaques when treatment is initiated at advanced stages of disease, including up to 8 d after challenge.

  10. Analysis of human chorionic gonadotropin-monoclonal antibody ...

    Indian Academy of Sciences (India)

    Unknown

    used in high affinity systems to measure the association rate constant of the reaction and the functional capacity of the ligand (hCG) immobilized on the chip. We provide a rational explanation for the discrepancies generally observed in most of the BIAcore sensograms. [Ashish B and Murthy G S 2004 Analysis of human ...

  11. Characterization of Entamoeba histolytica intermediate subunit lectin-specific human monoclonal antibodies generated in transgenic mice expressing human immunoglobulin loci.

    Science.gov (United States)

    Tachibana, Hiroshi; Cheng, Xun-Jia; Tsukamoto, Hideo; Itoh, Johbu

    2009-01-01

    Four fully human monoclonal antibodies (MAbs) to Entamoeba histolytica intermediate subunit lectin (Igl) were prepared in XenoMouse mice, which are transgenic mice expressing human immunoglobulin loci. Examination of the reactivities of these MAbs to recombinant Igl1 and Igl2 of E. histolytica showed that XEhI-20 {immunoglobulin G2(kappa) [IgG2(kappa)]} and XEhI-28 [IgG2(kappa)] were specific to Igl1, XEhI-B5 [IgG2(kappa)] was specific to Igl2, and XEhI-H2 [IgM(kappa)] was reactive with both Igls. Gene analyses revealed that the V(H) and V(L) germ lines were VH3-48 and L2 for XEhI-20, VH3-21 and L2 for XEhI-28, VH3-33 and B3 for XEhI-B5, and VH4-4 and A19 for XEhI-H2, respectively. Flow cytometry analyses showed that the epitopes recognized by all of these MAbs were located on the surfaces of living trophozoites. Confocal microscopy demonstrated that most Igl1 and Igl2 proteins were colocalized on the surface and in the cytoplasm, but different localization patterns in intracellular vacuoles were also present. The preincubation of trophozoites with XEhI-20, XEhI-B5, and XEhI-H2 caused significant inhibition of the adherence of trophozoites to Chinese hamster ovary cells, whereas preincubation with XEhI-28 did not do so. XEhI-20, XEhI-B5, and XEhI-H2 were injected intraperitoneally into hamsters 24 h prior to intrahepatic challenge with E. histolytica trophozoites. One week later, the mean abscess size in groups injected with one of the three MAbs was significantly smaller than that in controls injected with polyclonal IgG or IgM isolated from healthy humans. These results demonstrate that human MAbs to Igls may be applicable for immunoprophylaxis of amebiasis.

  12. Human Neutralizing Monoclonal Antibody Inhibition of Middle East Respiratory Syndrome Coronavirus Replication in the Common Marmoset.

    Science.gov (United States)

    Chen, Zhe; Bao, Linlin; Chen, Cong; Zou, Tingting; Xue, Ying; Li, Fengdi; Lv, Qi; Gu, Songzhi; Gao, Xiaopan; Cui, Sheng; Wang, Jianmin; Qin, Chuan; Jin, Qi

    2017-06-15

    Middle East respiratory syndrome coronavirus (MERS-CoV) infection in humans is highly lethal, with a fatality rate of 35%. New prophylactic and therapeutic strategies to combat human infections are urgently needed. We isolated a fully human neutralizing antibody, MCA1, from a human survivor. The antibody recognizes the receptor-binding domain of MERS-CoV S glycoprotein and interferes with the interaction between viral S and the human cellular receptor human dipeptidyl peptidase 4 (DPP4). To our knowledge, this study is the first to report a human neutralizing monoclonal antibody that completely inhibits MERS-CoV replication in common marmosets. Monotherapy with MCA1 represents a potential alternative treatment for human infections with MERS-CoV worthy of evaluation in clinical settings. © Crown copyright 2017.

  13. Reactivity of eleven anti-human leucocyte monoclonal antibodies with lymphocytes from several domestic animals

    DEFF Research Database (Denmark)

    Aasted, Bent; Blixenkrone-Møller, Merete; Larsen, Else Bang

    1988-01-01

    Nine commercially available monoclonal antibodies and two monoclonal antibodies from The American Type Culture Collection, raised against various human leucocyte surface antigens, were tested on lymphocytes from cow, sheep, goat, swine, horse, cat, dog, mink, and rabbit as well as man. Four...... antibodies bound to lymphocytes from some of the animals. These were the antibodies against CD8 and CD4 antigen, the antibody to C3b-receptor, and the antibody to the HLA-DR antigen. The CD8 antigen-reactive antibody reacted with lymphocytes from mink, cat, dog, and sheep, while the CD4 antigen......-reactive antibody reacted with lymphocytes from mink. The anti-C3b-R antibody reacted with lymphocytes from horse, swine, dog, and cat, and the anti-HLA-DR reacted with lymphocytes from cow, goat, sheep, horse, dog, cat, and mink....

  14. Biochemical Characterization of Human Anti-Hepatitis B Monoclonal Antibody Produced in the Microalgae Phaeodactylum tricornutum.

    Directory of Open Access Journals (Sweden)

    Gaëtan Vanier

    Full Text Available Monoclonal antibodies (mAbs represent actually the major class of biopharmaceuticals. They are produced recombinantly using living cells as biofactories. Among the different expression systems currently available, microalgae represent an emerging alternative which displays several biotechnological advantages. Indeed, microalgae are classified as generally recognized as safe organisms and can be grown easily in bioreactors with high growth rates similarly to CHO cells. Moreover, microalgae exhibit a phototrophic lifestyle involving low production costs as protein expression is fueled by photosynthesis. However, questions remain to be solved before any industrial production of algae-made biopharmaceuticals. Among them, protein heterogeneity as well as protein post-translational modifications need to be evaluated. Especially, N-glycosylation acquired by the secreted recombinant proteins is of major concern since most of the biopharmaceuticals including mAbs are N-glycosylated and it is well recognized that glycosylation represent one of their critical quality attribute. In this paper, we assess the quality of the first recombinant algae-made mAbs produced in the diatom, Phaeodactylum tricornutum. We are focusing on the characterization of their C- and N-terminal extremities, their signal peptide cleavage and their post-translational modifications including N-glycosylation macro- and microheterogeneity. This study brings understanding on diatom cellular biology, especially secretion and intracellular trafficking of proteins. Overall, it reinforces the positioning of P. tricornutum as an emerging host for the production of biopharmaceuticals and prove that P. tricornutum is suitable for producing recombinant proteins bearing high mannose-type N-glycans.

  15. Characterization of a monoclonal antibody against the 3D polymerase of enterovirus 71 and its use for the detection of human enterovirus A infection.

    Science.gov (United States)

    Kiener, Tanja K; Lim, Xiao Fang; Jia, Qiang; Meng, Tao; Chow, Vincent Tak Kwong; Kwang, Jimmy

    2012-03-01

    Over the last decade, frequent epidemic outbreaks of hand, foot and mouth disease have been observed in the Asia-Pacific region. Hand, foot and mouth disease is caused by different viruses from the enterovirus family, mainly coxsackievirus A16 and enterovirus 71 (EV71) from the human enterovirus A family. Severe disease and neurological complications are associated more often with EV71 infection, and can lead occasionally to fatal brain stem encephalitis in young children. The rapid progression and high mortality of severe hand, foot and mouth disease makes the direct detection of antigens early in infection essential. The best method for virus detection is the use of specific monoclonal antibodies. The generation and characterization of a monoclonal antibody specific for the 3D polymerase of human enterovirus A and the development of a virus detection dot blot assay are described. A recombinant 3CD protein from EV71 C4 strain was used as an immunogen to generate monoclonal antibodies (MAbs). Screening of hybridoma cells led to the isolation of monoclonal antibody 4B12 of the immunoglobulin IgG1 isotype. MAb 4B12 recognizes the linear epitope DFEQALFS close to the active site of the 3D polymerase, corresponding to amino acid positions 53-60 of 3D and 1784-1791 of enterovirus 71 polyprotein. The presence of 3D polymerase and its precursor 3CD proteinase in purified virus particles was confirmed. MAb 4B12 was used successfully to detect all enterovirus 71 subgenotypes in a denaturing dot blot assay with a sensitivity of 10 pg of 3D protein and 10(4) tissue culture infective dose of virus particles. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. The Effects of Anti-Hcg Monoclonal Antibodies on Human Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Mirshahi M

    2011-12-01

    Full Text Available Background: Human cancer cell lines express human choriogonadotropin (hCG, its subunits and derivatives, regardless of their origin and type. It appears that hCG is a common phenotype in human cancer cell lines. In this research, the effects of hCG targeting monoclonal antibodies (7D9, T18H7 and T8B12 on human cancer cell lines were evaluated. Methods: Monoclonal antibody secreting hybridomas were proliferated and injected intraperitoneally to Balb/C mice after treatment with pristine. Two weeks later, ascites fluid was collected. Purification of aforementioned antibodies from ascites fluid was performed using G-protein affinity followed by ion exchange chromatography. SDS-PAGE and ELISA confirmed the structure and functional integrity of the purified antibodies, respectively. Two human cancer cell lines "Hela" and "MDA" were treated by the purified antibodies. Three days later, different wells were imaged and the cells counted. Results: SDS-PAGE gel (None-reducing indicated consistency of band migration patterns with control antibodies. ELISA test using hCG antigens indicated that the produced antibodies could detect hCG antigens. Cell lines were cultured and treated with different concentrations of each antibody. Counting and imaging different wells of treated plates, indicated that 7D9 antibody had a more significant (P<0.01 cytotoxic effect on cancer cell lines than the control cells. Conclusion: HCG targeting monoclonal antibodies can be used for targeted cancer therapy, as human cancer cells express hCG gene. 7D9 antibody that exhibits protease activity is a proper candidate for this purpose, as it possesses both antagonistic and enzymatic properties.

  17. Construction of retroviral recombinant containing human tissue ...

    African Journals Online (AJOL)

    Correct orientation was verified by restriction endonuclease digestion. Human full length TIMP-2 gene was ligated into a plasmid, which was then transfected into PA317 cell line. G418-resistant individual clones were selected to transfect human SGC-7901 cell line. Cell proliferation, cell electrophoresis, soft agar colony ...

  18. [Generation of recombinant human antibodies for EV71 virus].

    Science.gov (United States)

    Sun, Li-Na; Zhang, Li; Zhang, Fu-Shun; Li, Chuan; Zhang, Quan-Fu; Li, De-Xin; Liang, Mi-Fang

    2011-06-01

    To obtain recombinant human anti-EV71 antibodies from a EV71-associated hand-foot-and-mouth disease patient-derived antibody phage library. A combinatorial human scFv library to enterovirus 71 (EV71) virus was constructed using antibody genes harvested from the blood of EV71 virus patients. The library was panned and selected by using purified VP1 protein of EV71 virus with phage display. After that the specific antibody was converted to full human IgG antibody with recombinant baculovirus/insect cell system. One unique human scFv antibody specific for EV71 virus VP1 protein was obtained by ELISA, IFA and analysis of the antibody DNA sequence. The specific anti-VP1 human scFv antibody was converted to full human IgG antibody with recombinant baculovirus/insect cell system. The full human IgG antibody was tested in vitro for EV71 virus neutralization, resulting in no neutralizing activity with EV71 A type and EV71 C4 subtype. The obtained human anti-EV71 antibodies without neutralizing activity laid the foundation for diagnosis of human EV71-associated hand-foot-and-mouth disease.

  19. Fully-human Monoclonal Antibodies Against Human EphrinB2 and EphB4 | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute's Cancer and Inflammation Program is seeking statements of capability or interest from parties interested in licensing fully-human monoclonal antibodies against human EphrinB2 and EphB4.

  20. Recombination in the human Pseudoautosomal region PAR1.

    Directory of Open Access Journals (Sweden)

    Anjali G Hinch

    2014-07-01

    Full Text Available The pseudoautosomal region (PAR is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  1. Effect of recombinant human erythropoietin expressions of apoptosis ...

    African Journals Online (AJOL)

    Effect of recombinant human erythropoietin expressions of apoptosis genes in rats following traumatic brain injury. Xuesong Yuan1*, Xiaoxing Bian1, Wenfeng Wei1, Yin Tang2 and Qing Bao1. 1Department of Neurosurgery, 2Department of Pathology, The Affiliated Wujin Hospital of Jiangsu University, Changzhou. Jiangsu ...

  2. Effects of recombinant human nerve growth factor on cervical cancer ...

    African Journals Online (AJOL)

    Nerve growth factor (NGF) plays a crucial role in the life of the sympathetic and sensory nervous systems. However, the roles of NGF to cervical cancer remain deeply unknown. This study investigated the effect of recombinant human nerve growth factor (rhNGF) on cervical cancer. It was found that the proliferation of hela ...

  3. Improved Refolding Efficacy of Recombinant Human Interferon α-2b ...

    African Journals Online (AJOL)

    Purpose: To increase the refolding yield of Recombinant Human Interferon α-2b in order to achieve a highly potent product. Methods: Interferon α-2b inclusion body was dissolved in tris-HCl buffer containing 6 M guanidine-HCl and CuSO4. Different refolding buffers were employed for refolding the target protein.

  4. Production and Characterization of a Murine Monoclonal Antibody Against Human Ferritin

    Science.gov (United States)

    Bayat, Ali Ahmad; Yeganeh, Omid; Ghods, Roya; Zarnani, Amir Hassan; Ardekani, Reza Bahjati; Mahmoudi, Ahmad Reza; Mahmoudian, Jafar; Haghighat-Noutash, Farzaneh; Jeddi-Tehrani, Mahmood

    2013-01-01

    Background Ferritin is an iron storage protein, which plays a key role in iron metabolism. Measurement of ferritin level in serum is one of the most useful indicators of iron status and also a sensitive measurement of iron deficiency. Monoclonal antibodies may be useful as a tool in various aspects of ferritin investigations. In this paper, the production of a murine monoclonal antibody (mAb) against human ferritin was reported. Methods Balb/c mice were immunized with purified human ferritin and splenocytes of hyper immunized mice were fused with Sp2/0 myeloma cells. After four times of cloning by limiting dilution, a positive hybridoma (clone: 2F9-C9) was selected by ELISA using human ferritin. Anti-ferritin mAb was purified from culture supernatants by affinity chromatography. Results Determination of the antibody affinity for ferritin by ELISA revealed a relatively high affinity (2.34×109 M -1) and the isotype was determined to be IgG2a. The anti-ferritin mAb 2F9-C9 reacted with 79.4% of Hela cells in flow cytometry. The antibody detected a band of 20 kDa in K562 cells, murine and human liver lysates, purified ferritin in Western blot and also ferritin in human serum. Conclusion This mAb can specifically recognize ferritin and may serve as a component of ferritin diagnostic kit if other requirements of the kit are met. PMID:24285995

  5. Design and Characterization of a Human Monoclonal Antibody that Modulates Mutant Connexin 26 Hemichannels Implicated in Deafness and Skin Disorders

    Directory of Open Access Journals (Sweden)

    Liang Xu

    2017-09-01

    Full Text Available Background: Mutations leading to changes in properties, regulation, or expression of connexin-made channels have been implicated in 28 distinct human hereditary diseases. Eight of these result from variants of connexin 26 (Cx26, a protein critically involved in cell-cell signaling in the inner ear and skin. Lack of non-toxic drugs with defined mechanisms of action poses a serious obstacle to therapeutic interventions for diseases caused by mutant connexins. In particular, molecules that specifically modulate connexin hemichannel function without affecting gap junction channels are considered of primary importance for the study of connexin hemichannel role in physiological as well as pathological conditions. Monoclonal antibodies developed in the last three decades have become the most important class of therapeutic biologicals. Recombinant methods permit rapid selection and improvement of monoclonal antibodies from libraries with large diversity.Methods: By screening a combinatorial library of human single-chain fragment variable (scFv antibodies expressed in phage, we identified a candidate that binds an extracellular epitope of Cx26. We characterized antibody action using a variety of biochemical and biophysical assays in HeLa cells, organotypic cultures of mouse cochlea and human keratinocyte-derived cells.Results: We determined that the antibody is a remarkably efficient, non-toxic, and completely reversible inhibitor of hemichannels formed by connexin 26 and does not affect direct cell-cell communication via gap junction channels. Importantly, we also demonstrate that the antibody efficiently inhibits hyperative mutant Cx26 hemichannels implicated in autosomal dominant non-syndromic hearing impairment accompanied by keratitis and hystrix-like ichthyosis-deafness (KID/HID syndrome. We solved the crystal structure of the antibody, identified residues that are critical for binding and used molecular dynamics to uncover its mechanism of action

  6. Insights into the chicken IgY with emphasis on the generation and applications of chicken recombinant monoclonal antibodies.

    Science.gov (United States)

    Lee, Warren; Syed Atif, Ali; Tan, Soo Choon; Leow, Chiuan Herng

    2017-08-01

    The advantages of chicken (Gallus gallus domesticus) antibodies as immunodiagnostic and immunotherapeutic biomolecules has only been recently recognized. Even so, chicken antibodies remain less-well characterized than their mammalian counterparts. This review aims at providing a current overview of the structure, function, development and generation of chicken antibodies. Additionally, brief but comprehensive insights into current knowledge pertaining to the immunogenetic framework and diversity-generation of the chicken immunoglobulin repertoire which have contributed to the establishment of recombinant chicken mAb-generating methods are discussed. Focus is provided on the current methods used to generate antibodies from chickens with added emphasis on the generation of recombinant chicken mAbs and its derivative formats. The advantages and limitations of established protocols for the generation of chicken mAbs are highlighted. The various applications of recombinant chicken mAbs and its derivative formats in immunodiagnostics and immunotherapy are further detailed. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Expression and characterization of recombinant human serum ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... HSA polyclonal antibody was purchased from the Chengdu biological products, CP antibodies and CP standard were purchased from the Jingmei Co.(Nanjing,. China). Construction of fusion gene human serum albumin-CP (HSA-. CP). The CP gene was cloned from plasmid T-CP by polymerase chain.

  8. Ligation of human Fc receptor like-2 by monoclonal antibodies down-regulates B-cell receptor-mediated signalling

    Science.gov (United States)

    Shabani, Mahdi; Bayat, Ali Ahmad; Jeddi-Tehrani, Mahmood; Rabbani, Hodjatallah; Hojjat-Farsangi, Mohammad; Ulivieri, Cristina; Amirghofran, Zahra; Baldari, Cosima Tatiana; Shokri, Fazel

    2014-01-01

    B-cell antigen receptor (BCR) signalling and its regulation through negative and positive regulators are critical for balancing B-cell response and function. Human Fc receptor like-2 (FCRL2), a member of the newly identified FCRL family, could influence B-cell signalling due to possession of both immunoreceptor tyrosine-based activation and inhibitory motifs (ITAM and ITIM). Since the natural ligand of FCRL2 has not been identified, we generated FCRL2-specific monoclonal antibodies (mAbs) and employed them to investigate the influence of FCRL2 stimulation on BCR signalling in an FCRL2-expressing B-cell line. Two anti-FCRL2 mAb-producing hybridoma clones (5A7-E7 and 3D8-G8) were selected. None of the mAbs displayed any cross-reactivity with the other members of the FCRL family including recombinant FCRL1, -3, -4 and -5, as tested by FACS and ELISA techniques. Engagement of the FCRL2 by these mAbs resulted in significant inhibition of BCR signalling mediators such as calcium mobilization and phosphorylation of the mitogen-activated protein kinases Erk, p38 and Jnk. These findings indicate that the FCRL2 ITIM motifs are functional and the anti-FCRL2 mAbs may mimic the natural ligand of FCRL2 by induction of inhibitory signals in B cells. PMID:24797767

  9. Development of broad-spectrum human monoclonal antibodies for rabies post-exposure prophylaxis.

    Science.gov (United States)

    De Benedictis, Paola; Minola, Andrea; Rota Nodari, Elena; Aiello, Roberta; Zecchin, Barbara; Salomoni, Angela; Foglierini, Mathilde; Agatic, Gloria; Vanzetta, Fabrizia; Lavenir, Rachel; Lepelletier, Anthony; Bentley, Emma; Weiss, Robin; Cattoli, Giovanni; Capua, Ilaria; Sallusto, Federica; Wright, Edward; Lanzavecchia, Antonio; Bourhy, Hervé; Corti, Davide

    2016-04-01

    Currently available rabies post-exposure prophylaxis (PEP) for use in humans includes equine or human rabies immunoglobulins (RIG). The replacement of RIG with an equally or more potent and safer product is strongly encouraged due to the high costs and limited availability of existing RIG. In this study, we identified two broadly neutralizing human monoclonal antibodies that represent a valid and affordable alternative to RIG in rabies PEP. Memory B cells from four selected vaccinated donors were immortalized and monoclonal antibodies were tested for neutralizing activity and epitope specificity. Two antibodies, identified as RVC20 and RVC58 (binding to antigenic site I and III, respectively), were selected for their potency and broad-spectrum reactivity. In vitro, RVC20 and RVC58 were able to neutralize all 35 rabies virus (RABV) and 25 non-RABV lyssaviruses. They showed higher potency and breath compared to antibodies under clinical development (namely CR57, CR4098, and RAB1) and commercially available human RIG. In vivo, the RVC20-RVC58 cocktail protected Syrian hamsters from a lethal RABV challenge and did not affect the endogenous hamster post-vaccination antibody response. © 2016 Humabs BioMed SA Published under the terms of the CC BY 4.0 license.

  10. Bacterial expression of a human monoclonal antibody-alkaline phosphatase conjugate specific for Entamoeba histolytica.

    Science.gov (United States)

    Tachibana, Hiroshi; Takekoshi, Masataka; Cheng, Xun-Jia; Nakata, Yuta; Takeuchi, Tsutomu; Ihara, Seiji

    2004-01-01

    We previously produced human monoclonal antibody Fab fragments specific to Entamoeba histolytica in Escherichia coli. In order to use these Fab fragments for diagnostic purposes, an expression vector to produce a fusion protein of Fab and alkaline phosphatase (PhoA) in E. coli was designed and constructed. The E. coli PhoA gene was fused to the 3' terminus of the gene encoding the heavy-chain Fd region. The kappa and Fd genes from a previously prepared antibody clone, CP33, which is specific for the 260-kDa lectin of E. histolytica, were used as human antibody genes. When the fusion protein of CP33 and PhoA was incubated with paraformaldehyde-fixed trophozoites of E. histolytica and developed with a substrate, the trophozoites appeared to be stained. These results demonstrate the feasibility of bacterial expression of a human monoclonal antibody-PhoA conjugate specific for E. histolytica and that the antibody can be used to detect E. histolytica antigen without the use of chemically conjugated secondary antibodies.

  11. Prophylactic and therapeutic activity of fully human monoclonal antibodies directed against Influenza A M2 protein

    Directory of Open Access Journals (Sweden)

    Gwerder Myriam

    2009-12-01

    Full Text Available Abstract Influenza virus infection is a prevalent disease in humans. Antibodies against hemagglutinin have been shown to prevent infection and hence hemagglutinin is the major constituent of current vaccines. Antibodies directed against the highly conserved extracellular domain of M2 have also been shown to mediate protection against Influenza A infection in various animal models. Active vaccination is generally considered the best approach to combat viral diseases. However, passive immunization is an attractive alternative, particularly in acutely exposed or immune compromized individuals, young children and the elderly. We recently described a novel method for the rapid isolation of natural human antibodies by mammalian cell display. Here we used this approach to isolate human monoclonal antibodies directed against the highly conserved extracellular domain of the Influenza A M2 protein. The identified antibodies bound M2 peptide with high affinities, recognized native cell-surface expressed M2 and protected mice from a lethal influenza virus challenge. Moreover, therapeutic treatment up to 2 days after infection was effective, suggesting that M2-specific monoclonals have a great potential as immunotherapeutic agents against Influenza infection.

  12. 75 FR 18548 - In the Matter of Certain Products and Pharmaceutical Compositions Containing Recombinant Human...

    Science.gov (United States)

    2010-04-12

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION In the Matter of Certain Products and Pharmaceutical Compositions Containing Recombinant Human... pharmaceutical compositions containing recombinant human erythropoietin by reason of infringement of claims 1 and...

  13. Monoclonal antibodies recognizing the non-tandem repeat regions of the human mucin MUC4 in pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Maneesh Jain

    Full Text Available The MUC4 mucin is a high molecular weight, membrane-bound, and highly glycosylated protein. It is a multi-domain protein that is putatively cleaved into a large mucin-like subunit (MUC4α and a C-terminal growth-factor like subunit (MUC4β. MUC4 plays critical roles in physiological and pathological conditions and is aberrantly overexpressed in several cancers, including those of the pancreas, cervix, breast and lung. It is also a potential biomarker for the diagnosis, prognosis and progression of several malignancies. Further, MUC4 plays diverse functional roles in cancer initiation and progression as evident from its involvement in oncogenic transformation, proliferation, inhibition of apoptosis, motility and invasion, and resistance to chemotherapy in human cancer cells. We have previously generated a monoclonal antibody 8G7, which is directed against the TR region of MUC4, and has been extensively used to study the expression of MUC4 in several malignancies. Here, we describe the generation of anti-MUC4 antibodies directed against the non-TR regions of MUC4. Recombinant glutathione-S-transferase (GST-fused MUC4α fragments, both upstream (MUC4α-N-Ter and downstream (MUC4α-C-Ter of the TR domain, were used as immunogens to immunize BALB/c mice. Following cell fusion, hybridomas were screened using the aforementioned recombinant proteins ad lysates from human pancreatic cell lines. Three anti MUC4α-N-Ter and one anti-MUC4α-C-Ter antibodies were characterized by several inmmunoassays including enzyme-linked immunosorbent assay (ELISA, immunoblotting, immunofluorescene, flow cytometry and immunoprecipitation using MUC4 expressing human pancreatic cancer cell lines. The antibodies also reacted with the MUC4 in human pancreatic tumor sections in immunohistochemical analysis. The new domain-specific anti-MUC4 antibodies will serve as important reagents to study the structure-function relationship of MUC4 domains and for the development of MUC4

  14. Potent Human Monoclonal Antibodies against SARS CoV, Nipah and Hendra Viruses

    Science.gov (United States)

    Prabakaran, Ponraj; Zhongyu, Zhu; Xiao, Xiaodong; Biragyn, Arya; Dimitrov, Antony S.; Broder, Christopher C.; Dimitrov, Dimiter S.

    2009-01-01

    Polyclonal antibodies have a century-old history of being effective against some viruses; recently, monoclonal antibodies (mAbs) have also shown success. The humanized mAb Synagis (palivizumab) remains still the only mAb against respiratory syncytial virus (RSV) infections approved by the U.S. Food and Drug Administration (FDA). Recently, several potent human monoclonal antibodies (hmAbs) targeting the Severe Acute Respiratory Syndrome-Associated coronavirus (SARS CoV) S glycoproteins were developed quickly after the virus was identified in 2003. Among these antibodies, m396 and S230.15 exhibit exceptional potency and cross-reactivity as they neutralize isolates from the first and second outbreaks and from palm civets both in vitroand in mice. Similarly, the first fully hmAbs against two other paramyxoviruses, Hendra virus (HeV) and Nipah virus (NiV), which can cause up to 75% mortality, were recently developed; one of them, m102.4, shows exceptional cross-reactive potency against both NiV and HeV. Three-dimensional molecular structures of envelope glycoproteins from these viruses in complexes with antibodies and/or receptors were recently determined. Structural analyses along with other experiments have provided insights into the molecular mechanisms of receptor recognition and antibody neutralization, and suggested that these antibodies alone or in combination could successfully fight the viruses’ heterogeneity and mutability which is a major problem in the development of effective therapeutic agents against viruses, including therapeutic antibodies. PMID:19216624

  15. Elastolytic activity of human blood monocytes characterized by a new monoclonal antibody against human leucocyte elastase. Relationship to rheumatoid arthritis

    DEFF Research Database (Denmark)

    Jensen, H S; Christensen, L D

    1990-01-01

    The leucocyte elastase of human blood monocytes was investigated by applying a new monoclonal antibody which did not block the enzyme activity against elastin. In a fixed population of mononuclear cells (MNC) and using fluorescence activated cell sorting (FACS), the human leucocyte elastase (HLE......) antibody identified a subgroup of CD14+ cells which contained all the elastase activity and which could be blocked by a specific chloromethylketone elastase inhibitor. By anti-CD14 labelling the HLE positive cells were identified as monocytes and amounted to 88% of this cell type (median: range 72...

  16. Human oligoclonal recombinant antivenom against the black mamba (Dendroaspis polylepis)

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard; Karatt-­Vellatt, Aneesh; Slavny, Peter

    Snakebite envenoming is a major cause of death and morbidity in tropical parts of the world. Current therapies are based on animal-­derived antisera that are associated with a high degree of immunogenicity, high cost, and batch-to-batch variation. Here, we report the results of our ongoing efforts...... of developing the world’s first fully recombinant antivenom based on human IgGs targeting the key toxins from the notorious black mamba (Dendroaspis polylepis)....

  17. Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition

    DEFF Research Database (Denmark)

    Green, M R; Couchman, J R

    1985-01-01

    Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map...

  18. Novel rabies virus-neutralizing epitope recognized by human monoclonal antibody: Fine mapping and escape mutant analysis

    NARCIS (Netherlands)

    Marissen, W.E.; Kramer, R.A.; Rice, A.; Weldon, W.C.; Niezgoda, M.; Faber, M.; Slootstra, J.W.; Meloen, R.H.; Clijsters-van der Horst, M.; Visser, T.J.; Jongeneelen, M.; Thijsse, S.; Throsby, M.; Kruif, de J.; Rupprecht, C.E.; Dietzschold, B.; Goudsmit, J.; Bakker, A.B.H.

    2005-01-01

    Anti-rabies virus immunoglobulin combined with rabies vaccine protects humans from lethal rabies infections. For cost and safety reasons, replacement of the human or equine polyclonal immunoglobulin is advocated, and the use of rabies virus-specific monoclonal antibodies (MAbs) is recommended. We

  19. Novel rabies virus-neutralizing epitope recognized by human monoclonal antibody: fine mapping and escape mutant analysis

    NARCIS (Netherlands)

    Marissen, Wilfred E.; Kramer, R. Arjen; Rice, Amy; Weldon, William C.; Niezgoda, Michael; Faber, Milosz; Slootstra, Jerry W.; Meloen, Rob H.; Clijsters-van der Horst, Marieke; Visser, Therese J.; Jongeneelen, Mandy; Thijsse, Sandra; Throsby, Mark; de Kruif, John; Rupprecht, Charles E.; Dietzschold, Bernhard; Goudsmit, Jaap; Bakker, Alexander B. H.

    2005-01-01

    Anti-rabies virus immunoglobulin combined with rabies vaccine protects humans from lethal rabies infections. For cost and safety reasons, replacement of the human or equine polyclonal immunoglobulin is advocated, and the use of rabies virus-specific monoclonal antibodies (MAbs) is recommended. We

  20. The preparation, characterization, and application of environment-friendly monoclonal antibodies for human blood cell.

    Science.gov (United States)

    Zhou, Chenjie; Gao, Xuechao; He, Shixiang; Gao, Xiaoling; Zhuang, Jialin; Huang, Lirong; Guo, Hengchang

    2017-03-01

    Monoclonal anti-human blood group A (51A8) and B (63B6) antibody reagents were prepared using the serum-free technique. The aims of this research were to characterize the serum-free reagents and prove their reliabilities in routine use. Experiments including antigen-antibody agglutination testing, stability testing, SDS-PAGE, protein and IgM quantification, flow cytometry, and variable domain sequencing were performed to characterize the anti-A (51A8) and anti-B (63B6) reagents. Over 12 000 samples were tested using these reagents as routine blood grouping reagents. Serum-free anti-A (51A8) and anti-B (63B6) reagents were stable in longitudinal and accelerated testing, and their high purity was shown in SDS-PAGE and IgM quantification. These reagents have high specificity to red blood cells in serologic agglutination testing and flow cytometric analysis. A1 and A2 subgroup antigens can be distinguished clearly by patterns of flow cytometric histograms. No discrepancy was found in clinical trials of 12 000 samples. To reduce the risk of being affected by any animal additives, a serum-free culture system was applied to get mass-production of monoclonal anti-A/B antibodies. The high specificity and the high purity of the reagents were verified by the lab experiments. Lab research and clinical trial showed that serum-free monoclonal anti-A (51A8) and anti-B (63B6) reagents meet the requirements of routine blood grouping reagents. Moreover, these reagents featured ultra-high purity that is missing in other commercial counterparts, and therefore are recommended as more environment-friendly reagents.

  1. Frequency of lipodystrophy induced by recombinant human insulin.

    Science.gov (United States)

    Hajheydari, Z; Kashi, Z; Akha, O; Akbarzadeh, S

    2011-10-01

    Lipodystrophy is a potential clinical complication induced by insulin therapy, and it is believed that its frequency has been reduced by using recombinant human insulin. Aim of this study was to determine the frequency of recombinant human insulin induced lipodystrophy in diabetic patients. This cross sectional study was done on 220 diabetics referring to Imam Educational Hospital of Sari Township in 2007-2008 who had been under treatment with recombinant human insulin at least three months before. First, the anthropologic and clinical features of the patients were recorded in questionnaire, then all of the patients were examined clinically for lipodystrophy. In all patients, glycosylated hemoglobin (HbA1C) was measured for control of the blood glucose. The obtained data were analyzed by the descriptive statistical methods, t-test and 2 test. From the total 220 diabetics under study, 35 (15.9%) had insulin induced lipodystrophy, of them 32 (14.5%) had lipohypertrophy and 3 (1.4%) with lipoatrophy. Factors such as age, sex, level of education, body mass index (BMI), type of diabetes, period of using insulin and injection site had significant influence in development of insulin induced lipodystrophy (plipodystrophy particularly of lipohypertrophy still remained high level. Therefore, a regular examination of the diabetic patients for this complication is necessary, specially in the individuals who have a defective control on their blood glucose level.

  2. Monoclonal antibodies reacting with multiple epitopes on the human insulin receptor.

    Science.gov (United States)

    Soos, M A; Siddle, K; Baron, M D; Heward, J M; Luzio, J P; Bellatin, J; Lennox, E S

    1986-04-01

    Monoclonal antibodies for the human insulin receptor were produced following immunization of mice with IM-9 lymphocytes and/or purified placental receptor. Four separate fusions yielded 28 antibodies, all of which reacted with receptor from human placenta, liver and IM-9 cells. Some antibodies cross-reacted to varying degrees with receptor from rabbit, cow, pig and sheep, but none reacted with rat receptor. At least 10 distinct epitopes were recognized as indicated by species specificity and binding competition experiments. All of these epitopes appeared to be on extracellular domains of the receptor as shown by binding of antibodies to intact cells. In some cases the epitopes were further localized to alpha or beta subunits by immunoblotting. Several antibodies inhibited binding of 125I-insulin to the receptor, some had no effect on binding, and others enhanced the binding of 125I-insulin. It is concluded that these antibodies will be valuable probes of receptor structure and function.

  3. Stoichiometry of monoclonal antibody neutralization of T-cell line-adapted human immunodeficiency virus type 1

    DEFF Research Database (Denmark)

    Schønning, Kristian; Lund, O; Lund, O S

    1999-01-01

    In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes are coexpr......In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes...

  4. Human anti-plague monoclonal antibodies protect mice from Yersinia pestis in a bubonic plague model.

    Directory of Open Access Journals (Sweden)

    Xiaodong Xiao

    2010-10-01

    Full Text Available Yersinia pestis is the etiologic agent of plague that has killed more than 200 million people throughout the recorded history of mankind. Antibiotics may provide little immediate relief to patients who have a high bacteremia or to patients infected with an antibiotic resistant strain of plague. Two virulent factors of Y. pestis are the capsid F1 protein and the low-calcium response (Lcr V-protein or V-antigen that have been proven to be the targets for both active and passive immunization. There are mouse monoclonal antibodies (mAbs against the F1- and V-antigens that can passively protect mice in a murine model of plague; however, there are no anti-Yersinia pestis monoclonal antibodies available for prophylactic or therapeutic treatment in humans. We identified one anti-F1-specific human mAb (m252 and two anti-V-specific human mAb (m253, m254 by panning a naïve phage-displayed Fab library against the F1- and V-antigens. The Fabs were converted to IgG1s and their binding and protective activities were evaluated. M252 bound weakly to peptides located at the F1 N-terminus where a protective mouse anti-F1 mAb also binds. M253 bound strongly to a V-antigen peptide indicating a linear epitope; m254 did not bind to any peptide from a panel of 53 peptides suggesting that its epitope may be conformational. M252 showed better protection than m253 and m254 against a Y, pestis challenge in a plague mouse model. A synergistic effect was observed when the three antibodies were combined. Incomplete to complete protection was achieved when m252 was given at different times post-challenge. These antibodies can be further studied to determine their potential as therapeutics or prophylactics in Y. pestis infection in humans.

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

    Science.gov (United States)

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

    2017-07-01

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

  6. Systemic lupus erythematosus: molecular cloning of fourteen recombinant DNase monoclonal kappa light chains with different catalytic properties.

    Science.gov (United States)

    Kostrikina, Irina A; Buneva, Valentina N; Nevinsky, Georgy A

    2014-06-01

    DNase antibodies can play an important role in the pathogenesis of different autoimmune pathologies. An immunoglobulin light chain phagemid library derived from peripheral blood lymphocytes of patients with systemic lupus erythematosus (SLE) was used. The small pools of phage particles displaying DNA binding light chains with different for DNA were isolated by affinity chromatography on DNA-cellulose and the fraction eluted with 0.5M NaCl was used for preparation of individual monoclonal light chains (MLChs, 28kDa). Forty-five of 451 individual colonies were randomly chosen for a study of MLChs with DNase activity. The clones were expressed in Escherichia coli in a soluble form, and MLChs were purified by metal chelating chromatography followed by gel filtration, and studied in detail. Fifteen of 45 MLChs efficiently hydrolyzed DNA, and fourteen of them demonstrated various optimal concentrations of KCl or NaCl in a 1-100mM range and showed one or two pH optima in a 4.8-9.1 range. All MLChs were dependent on divalent metal cations: the ratio of relative DNase activity in the presence of Mn(2+), Ca(2+), Mg(2+), Ni(2+), Zn(2+), Cu(2+), and Co(2+) was individual for each MLCh preparation. Fourteen MLChs demonstrated a comparable affinity for DNA (260-320nM), but different kcat values (0.02-0.7min(-1)). These observations suggest an extreme diversity of DNase abzymes from SLE patients. SLE light chain repertoire can serve as a source of new types of DNases. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Recombinant monoclonal antibody yield in transgenic tobacco plants is affected by the wounding response via an ethylene dependent mechanism.

    Science.gov (United States)

    Hassan, Sally; Colgan, Richard; Paul, Mathew J; Atkinson, Christopher J; Sexton, Amy L; van Dolleweerd, Craig J; Keshavarz-Moore, Eli; Ma, Julian K-C

    2012-12-01

    Variability in recombinant IgG yield in transgenic tobacco plants has previously been observed in relation to leaf position, and is interpreted as a function of ageing and the senescence process, leading to increasing protein degradation. Here, similar findings are demonstrated in plants of different ages, expressing IgG but not IgG-HDEL, an antibody form that accumulates within the endoplasmic reticulum. Antibody yields declined following wounding in young transgenic plants expressing IgG but not in those expressing IgG-HDEL. However, in mature IgG plants, the opposite was demonstrated, with significant boosts in yield, while mature IgG-HDEL plants could not be boosted. The lack of response in IgG-HDEL plants suggests that the changes induced by wounding occur post-translationally, and the findings might be explained by wounding responses that differ in plants according to their developmental stages. Plant mechanisms involved in senescence and wounding overlap to a significant degree and compounds such as ethylene, jasmonic acid and salicylic acid are important for mediating downstream effects. Treatment of transgenic plants with ethylene also resulted in a decrease in recombinant IgG yield, which was consistent with the finding that wounded plants could induce lower IgG yields in neighbouring non-wounded plants. Treatment with 1-MCP, an ethylene antagonist, abrogated the IgG yield drop that resulted from wounding, but had no effect on the more gradual IgG yield loss associated with increasing plant age.

  8. Posttranslational modifications in human plasma MBL and human recombinant MBL

    DEFF Research Database (Denmark)

    Jensen, Pia Hønnerup; Laursen, Inga; Matthiesen, Finn

    2007-01-01

    Mannan-binding lectin (MBL) is a complex serum protein that plays an important role in innate immunity. In addition to assuming several different oligomeric forms, the polypeptide itself is highly heterogeneous. This heterogeneity is due to post-translational modifications, which help to stabilize......(202)) was modified in trace amounts to dehydroalanine, as detected by a 34 Da mass loss. This impairs the formation of a disulphide bond in the carbohydrate recognition domain. The dehydroalanine was identified in similar small amounts in both recombinant and plasma-derived MBL....

  9. Kinetic Characterization of a Panel of High-Affinity Monoclonal Antibodies Targeting Ricin and Recombinant Re-Formatting for Biosensor Applications

    Directory of Open Access Journals (Sweden)

    Michelle Cummins

    2014-05-01

    Full Text Available Ricin is a potent glycoprotein toxin that is structurally composed of two subunits joined via a disulfide bond: a ~30 kDa subunit A (RTA and a ~32 kDa subunit B (RTB. There are fears of ricin being used as a weapon for warfare and terrorism and, as such, there is an increasing need for the development of immunodiagnostic reagents targeted towards this toxin. This article describes the production and characterization of a panel of six ricin-specific monoclonal IgG antibodies (mAbs, previously selected based upon their ability to inhibit ricin-mediated killing of cultured cells. Subsequent epitope binding analysis using the surface plasmon resonance (SPR array biosensor (ProteOn XPR36 indicated three distinct, non-competitive binding epitopes (“bins”. The association (ka and dissociation (kd rate constants and binding affinities (KD of each of the mAbs to ricin were also determined by SPR using Biacore T100 instrument. Affinities (KD ranged from 0.1 nM to 9 nM. We present the coding sequences of the variable domains of the six mAbs, the expression, kinetic and cytotoxicity assays for two recombinant Fab (rFab fragments and demonstrate a rFab affinity improvement by chain-shuffling. Together, these antibodies and constituent rFabs represent a panel of reagents for high-affinity recognition of ricin with potential national security biosensor applications.

  10. Wheat germ cell-free system-based production of hemagglutinin-neuraminidase protein of human parainfluenza virus type 3: generation and characterization of monoclonal antibody

    Directory of Open Access Journals (Sweden)

    Satoko eMatsunaga

    2014-05-01

    Full Text Available Human parainfluenza virus 3 (HPIV3 commonly causes respiratory disorders in infants and young children. Monoclonal antibodies (MAbs have been produced to several components of HPIV3 and commercially available. However, the utility of these antibodies for several immunological and proteomic assays for understanding the nature of HPIV3 infection remain to be characterized. Herein, we report the development and characterization of monoclonal antibodies against hemagglutinin-neuraminidase (HN of HPIV3. A recombinant full-length HPIV3-HN was successfully synthesized using the wheat-germ cell-free protein production system. After immunization and cell fusion, 36 mouse hybridomas producing MAbs to HPIV3-HN were established. The MAbs obtained were fully characterized using ELISA, immunoblotting and immunofluorescent analyses. Of the MAbs tested, single clone was found to be applicable in both flow cytometry and immunoprecipitation procedures. By utilizing the antibody, we newly identified HPIV3-HN binding host proteins via immunoprecipitation-based mass spectrometry analysis. This study provides the availability of our newly-developed MAbs as a valuable tool for the study of HPIV3 infection as well as the several diagnostic tests of this virus.

  11. Anti-Human Endoglin (hCD105 Immunotoxin—Containing Recombinant Single Chain Ribosome-Inactivating Protein Musarmin 1

    Directory of Open Access Journals (Sweden)

    Begoña Barriuso

    2016-06-01

    Full Text Available Endoglin (CD105 is an accessory component of the TGF-β receptor complex, which is expressed in a number of tissues and over-expressed in the endothelial cells of tumor neovasculature. Targeting endoglin with immunotoxins containing type 2 ribosome-inactivating proteins has proved an effective tool to reduce blood supply to B16 mice tumor xenografts. We prepared anti-endoglin immunotoxin (IT—containing recombinant musarmin 1 (single chain ribosome-inactivating proteins linked to the mouse anti-human CD105 44G4 mouse monoclonal antibody via N-succinimidyl 3-(2-pyridyldithio propionate (SPDP. The immunotoxin specifically killed L929 fibroblast mouse cells transfected with the short form of human endoglin with IC50 values in the range of 5 × 10−10 to 10−9 M.

  12. Characterisation of new monoclonal antibodies reacting with prions from both human and animal brain tissues

    DEFF Research Database (Denmark)

    Hvass, Henriette Cordes; Bergström, Ann-Louise; Ohm, Jakob

    2008-01-01

    Post-mortem diagnosis of transmissible spongiform encephalopaties (prion diseases) is primarily based on the detection of a protease resistant, misfolded disease associated isoform (PrPSc) of the prion protein (PrPc) on neuronal cells. These methods depend on antibodies directed aganinst Pr......Pc and capable of reacting with PrpSc in situ (immunohistochemistry on nervous tissue sections) or with the unfolded form of the protein (western and paraffin embedded tissue (PET) blotting). Here, high-affinity monoclonal antibodies (mAbs 1.5D7, 1.6F4) were produced against synthetic PrP peptides in wild......-type mice and used for western blotting and immunohistochemistry to detect several types of human prion-disease associated PrPSc, including sporadic Creutzfeldt-Jakob Disease (CJD) (subtypes MM1 and V"), familial CJD and Gerstmann-Sträussler-Scheinker (GSS) disease PrPSc as well as PrPSc of bovine...

  13. Anion exchange chromatographic distribution of human monoclonal immunoglobulin G is determined by heavy chain subclass and level of sialic acid expression

    Directory of Open Access Journals (Sweden)

    Ilić Vesna

    2012-01-01

    Full Text Available Anion exchange chromatography is widely accepted method for purification of immunoglobulins. In this work, we used human monoclonal immunoglobulin G (IgG with structure and solubility of normal human IgG as a model for studying chromatographic behavior of particular molecular forms of IgG. Human sera with monoclonal IgG were fractionated on strong anion exchanger, Q Sepharose Fast Flow. With 20 mM Tris pH 7.5 as a start buffer, 42% of human monoclonal IgG passed through column, and 58% of them remained adsorbed. Bound monoclonal IgG were eluted from the exchanger by linear increasing of concentration of NaCl from 0 to 0.5 M. Chromatographic distribution of human monoclonal IgG correlated with their electrophoretic mobility in agarose gels, and it was dependent on γ heavy chain isotype. Light chain type, as well as serum concentration of monoclonal IgG did not influence their chromatographic behavior. The level of heavy chain sialic acid expression, but not of galactose and N-acetylglucosamine, significantly determined chromatographic distribution of serum monoclonal IgG. Additionally to the information on the chromatographic behavior of human monoclonal IgG, we believe that presented data could provide useful information about the possible use of Q Sepharose Fast Flow matrix for the isolation of specific molecular forms of human IgG.

  14. Inhibition of fibroblast growth factor receptor 3-dependent lung adenocarcinoma with a human monoclonal antibody

    Directory of Open Access Journals (Sweden)

    Yongjun Yin

    2016-05-01

    Full Text Available Activating mutations in fibroblast growth factor receptor 3 (FGFR3 have been identified in multiple types of human cancer and in congenital birth defects. In human lung cancer, fibroblast growth factor 9 (FGF9, a high-affinity ligand for FGFR3, is overexpressed in 10% of primary resected non-small cell lung cancer (NSCLC specimens. Furthermore, in a mouse model where FGF9 can be induced in lung epithelial cells, epithelial proliferation and ensuing tumorigenesis is dependent on FGFR3. To develop new customized therapies for cancers that are dependent on FGFR3 activation, we have used this mouse model to evaluate a human monoclonal antibody (D11 with specificity for the extracellular ligand-binding domain of FGFR3, that recognizes both human and mouse forms of the receptor. Here, we show that D11 effectively inhibits signaling through FGFR3 in vitro, inhibits the growth of FGFR3-dependent FGF9-induced lung adenocarcinoma in mice, and reduces tumor-associated morbidity. Given the potency of FGF9 in this mouse model and the absolute requirement for signaling through FGFR3, this study validates the D11 antibody as a potentially useful and effective reagent for treating human cancers or other pathologies that are dependent on activation of FGFR3.

  15. Quaternary structures of recombinant, cellular, and serum forms of Thymidine Kinase 1 from dogs and humans

    Directory of Open Access Journals (Sweden)

    Hanan Sharif

    2012-06-01

    Full Text Available Abstract Background Thymidine kinase 1 (TK1 is a salvage enzyme involved in DNA precursor synthesis, and its expression is proliferation dependent. A serum form of TK1 has been used as a biomarker in human medicine for many years and more recently to monitor canine lymphoma. Canine TK1 has not been cloned and studied. Therefore, dog and human TK1 cDNA were cloned and expressed, and the recombinant enzymes characterized. The serum and cellular forms of canine and human TK1 were studied by size-exclusion chromatography and the level of TK1 protein was determined using polyclonal and monoclonal anti-TK1 antibodies. Results Canine TK1 phosphorylated the thymidine (dThd analog 3'-azido-thymidine (AZT as efficiently as it did dThd, whereas AZT phosphorylation by human TK1 was less efficient than that of dThd. Dog TK1 was also more thermostable and pH tolerant than the human enzyme. Oligomeric forms were observed with both enzymes in addition to the tetrameric and dimeric forms. Cellular TK1 was predominantly seen in dimeric and tetrameric forms, in the case of both dog TK1 from MDCK cells and human TK1 from CEM cells. Active serum TK1 was found mainly in a high molecular weight form, and treatment with a reducing agent shifted the high molecular weight complex to lower molecular weight forms with reduced total activity. Western blot analysis demonstrated a polypeptide of 26 kDa (dog and 25 kDa (human for cellular and serum TK1. There was no direct correlation between serum TK1 activity and protein level. It appears that a substantial fraction of serum TK1 is not enzymatically active. Conclusions These results suggest that the serum TK1 protein differs from cellular or recombinant forms, is more active in high molecular weight complexes, and is sensitive to reducing agents. The results presented here provide important information for the future development and use of serum TK1 as a diagnostic biomarker in human and veterinary medicine.

  16. In vitro and in vivo properties of a fully human IgG1 monoclonal antibody that combats multidrug resistant Pseudomonas aeruginosa

    Science.gov (United States)

    ADAWI, AZMI; BISIGNANO, CARLO; GENOVESE, TIZIANA; FILOCAMO, ANGELA; KHOURI-ASSI, CAMELLIA; NEVILLE, ANAT; FEUERSTEIN, GIORA Z.; CUZZOCREA, SALVATORE; NEVILLE, LEWIS F.

    2012-01-01

    The development of an anti-bacterial drug in the form of a monoclonal antibody (mAb) targeting an exposed virulence factor, represents an innovative therapeutic strategy. Consequently, a fully human IgG1 mAb (LST-007) targeting Pseudomonas aeruginosa (PA) flagellin type b was recombinantly expressed and characterized in vitro and in an infection model driven by a multidrug resistant (MDR) PA strain. LST-007 demonstrated a highly specific binding towards whole PA bacteria harboring flagellin type b and its recombinant counterpart, with a KD of 7.4×10−10 M. In bioactivity assays, LST-007 or titers of Cmax sera derived from pharmacokinetic studies, markedly attenuated PA motility in an equipotent manner. In vivo, parenteral LST-007 (20 mg/kg) given as a single or double-dosing paradigm post-infection, afforded survival (up to 75% at Day 7) in a lethal model of pneumonia driven by the intratracheal (i.t.) instillation of an LD80 of the MDR PA isolate. This protective effect was markedly superior to that of imipenem (30% survival at Day 7) and totally devoid with an irrelevant, human isotype mAb. These data lay credence that LST-007 may be a valuable adjunct to the limited list of anti-bacterials that can tackle MDR PA strains, thereby warranting its continued development for eventual clinical evaluation. PMID:22735858

  17. Novel human monoclonal antibody combination effectively neutralizing natural rabies virus variants and individual in vitro escape mutants

    NARCIS (Netherlands)

    Bakker, Alexander B. H.; Marissen, Wilfred E.; Kramer, R. Arjen; Rice, Amy B.; Weldon, William C.; Niezgoda, Michael; Hanlon, Cathleen A.; Thijsse, Sandra; Backus, Harold H. J.; de Kruif, John; Dietzschold, Bernhard; Rupprecht, Charles E.; Goudsmit, Jaap

    2005-01-01

    The need to replace rabies immune globulin (RIG) as an essential component of rabies postexposure prophylaxis is widely acknowledged. We set out to discover a unique combination of human monoclonal antibodies (MAbs) able to replace RIG. Stringent criteria concerning neutralizing potency, affinity,

  18. Monoclonal antibodies for human and porcine histamine N-methyltransferase (HMT) facilitate protein expression and localization studies.

    Science.gov (United States)

    Schwelberger, Hubert G; Feurle, Johannes; Houen, Gunnar

    2017-01-01

    The lack of suitable antibodies for the histamine inactivating enzyme histamine N-methyltransferase (HMT) has so far prevented the direct analysis of HMT proteins in man and other mammals. A series of monoclonal antibodies was produced by immunizing mice with human and porcine HMT expressed in vitro. Antibodies were characterized by immunoblotting and immunohistochemical staining. Six different monoclonal antibodies specific for human HMT and four different monoclonal antibodies specific for porcine HMT were obtained that can detect HMT with up to tenfold greater sensitivity than the most sensitive enzymatic assays currently available. Using these antibodies allowed us to confirm the expression and cellular localization of HMT in various human and porcine tissues, where the presence of the enzyme had previously been deduced from activity measurement and HMT mRNA analysis. Immunohistochemical staining of human and porcine tissue sections clearly showed that HMT is a cytosolic protein, which is localized in specific cells of most mammalian tissues. The new monoclonal antibodies not only allow a comprehensive quantitative evaluation of the expression of HMT at the cellular level in man and other mammals but will also facilitate sensitive analyses of disease-associated alterations of this protein.

  19. First administration to humans of a monoclonal antibody cocktail against rabies virus: safety, tolerability, and neutralizing activity

    NARCIS (Netherlands)

    Bakker, A. B. H.; Python, C.; Kissling, C. J.; Pandya, P.; Marissen, W. E.; Brink, M. F.; Lagerwerf, F.; Worst, S.; van Corven, E.; Kostense, S.; Hartmann, K.; Weverling, G. J.; Uytdehaag, F.; Herzog, C.; Briggs, D. J.; Rupprecht, C. E.; Grimaldi, R.; Goudsmit, J.

    2008-01-01

    Immediate passive immune prophylaxis as part of rabies post-exposure prophylaxis (PEP) often cannot be provided due to limited availability of human or equine rabies immunoglobulin (HRIG and ERIG, respectively). We report first clinical data from two phase I studies evaluating a monoclonal antibody

  20. Paroxetine suppresses recombinant human P2X7 responses.

    Science.gov (United States)

    Dao-Ung, Phuong; Skarratt, Kristen K; Fuller, Stephen J; Stokes, Leanne

    2015-12-01

    P2X7 receptor (P2X7) activity may link inflammation to depressive disorders. Genetic variants of human P2X7 have been linked with major depression and bipolar disorders, and the P2X7 knockout mouse has been shown to exhibit anti-depressive-like behaviour. P2X7 is an ATP-gated ion channel and is a major regulator of the pro-inflammatory cytokine interleukin 1β (IL-1β) secretion from monocytes and microglia. We hypothesised that antidepressants may elicit their mood enhancing effects in part via modulating P2X7 activity and reducing inflammatory responses. In this study, we determined whether common psychoactive drugs could affect recombinant and native human P2X7 responses in vitro. Common antidepressants demonstrated opposing effects on human P2X7-mediated responses; paroxetine inhibited while fluoxetine and clomipramine mildly potentiated ATP-induced dye uptake in HEK-293 cells stably expressing recombinant human P2X7. Paroxetine inhibited dye uptake mediated by human P2X7 in a concentration-dependent manner with an IC(50) of 24 μM and significantly reduces ATP-induced inward currents. We confirmed that trifluoperazine hydrochloride suppressed human P2X7 responses (IC(50) of 6.4 μM). Both paroxetine and trifluoperazine did not inhibit rodent P2X7 responses, and mutation of a known residue (F 95L) did not alter the effect of either drug, suggesting neither drug binds at this site. Finally, we demonstrate that P2X7-induced IL-1β secretion from lipopolysaccharide (LPS)-primed human CD14(+) monocytes was suppressed with trifluoperazine and paroxetine.

  1. Monoclonal antibody GB3, a new probe for the study of human basement membranes and hemidesmosomes

    Energy Technology Data Exchange (ETDEWEB)

    Verrando, P.; Pisani, A.; Serieys, N.; Ortonne, J.P. (UER Medecine, Nice (France)); Hsi, Baeli; Yeh, Changjing (INSERM U210, Nice (France))

    1987-05-01

    A monoclonal antibody, GB3, has been raised against human amnion. Not only does GB3 bind to amniotic basement membrane, but it also recognizes an antigenic structure expressed by epidermal as well as by some other human basement membranes. This antigen is synthesized (and excreted) by cultured normal human epidermal keratinocytes. It is expressed to a lesser extent by the A431 epidermoid carcinoma cell line, but is not expressed by the SV40 virus-transformed SVK14 keratinocyte cell line. In ultrastructural studies, this antigen was located in the epidermal basement membrane, both in the lamina densa and in the lamina lucida, associated with hemidesmosomes. It was identified as a protein by in vitro proteolytic cleavage studies. The radio-immunoprecipitates from cultured human keratinocytes, analyzed by SDS-PAGE, showed that GB3 recognized five polypeptides of 93.5, 125, 130, 146 and 150 kD under reducing conditions. The tissue distribution of the antigen and the molecular weights (MWs) of its constitutive polypeptides suggest that it is different from other known components of basement membranes. It may provide a biochemical marker for hemidesmosomes. Furthermore, GB3 represents an interesting and original clinical probe, since the antigenic structure recognized by GB3 is lacking in Junctional Epidermolysis Bullosa, a lethal genodermatosis in which a dermo-epidermal splitting occurs at the level of lamina lucida.

  2. A novel human anti-interleukin-1β neutralizing monoclonal antibody showing in vivo efficacy.

    Science.gov (United States)

    Goh, Angeline X H; Bertin-Maghit, Sebastien; Ping Yeo, Siok; Ho, Adrian W S; Derks, Heidi; Mortellaro, Alessandra; Wang, Cheng-I

    2014-01-01

    The pro-inflammatory cytokine interleukin (IL)-1β is a clinical target in many conditions involving dysregulation of the immune system; therapeutics that block IL-1β have been approved to treat diseases such as rheumatoid arthritis (RA), neonatal onset multisystem inflammatory diseases, cryopyrin-associated periodic syndromes, active systemic juvenile idiopathic arthritis. Here, we report the generation and engineering of a new fully human antibody that binds tightly to IL-1β with a neutralization potency more than 10 times higher than that of the marketed antibody canakinumab. After affinity maturation, the derived antibody shows a>30-fold increased affinity to human IL-1β compared with its parent antibody. This anti-human IL-1β IgG also cross-reacts with mouse and monkey IL-1β, hence facilitating preclinical development. In a number of mouse models, this antibody efficiently reduced or abolished signs of disease associated with IL-1β pathology. Due to its high affinity for the cytokine and its potency both in vitro and in vivo, we propose that this novel fully human anti-IL-1β monoclonal antibody is a promising therapeutic candidate and a potential alternative to the current therapeutic arsenal.

  3. Isolation of HIV-1-neutralizing mucosal monoclonal antibodies from human colostrum.

    Directory of Open Access Journals (Sweden)

    James Friedman

    Full Text Available Generation of potent anti-HIV antibody responses in mucosal compartments is a potential requirement of a transmission-blocking HIV vaccine. HIV-specific, functional antibody responses are present in breast milk, and these mucosal antibody responses may play a role in protection of the majority of HIV-exposed, breastfeeding infants. Therefore, characterization of HIV-specific antibodies produced by B cells in milk could guide the development of vaccines that elicit protective mucosal antibody responses.We isolated B cells from colostrum of an HIV-infected lactating woman with a detectable neutralization response in milk and recombinantly produced and characterized the resulting HIV-1 Envelope (Env-specific monoclonal antibodies (mAbs.The identified HIV-1 Env-specific colostrum mAbs, CH07 and CH08, represent two of the first mucosally-derived anti-HIV antibodies yet to be reported. Colostrum mAb CH07 is a highly-autoreactive, weakly-neutralizing gp140-specific mAb that binds to linear epitopes in the gp120 C5 region and gp41 fusion domain. In contrast, colostrum mAb CH08 is a nonpolyreactive CD4-inducible (CD4i gp120-specific mAb with moderate breadth of neutralization.These novel HIV-neutralizing mAbs isolated from a mucosal compartment provide insight into the ability of mucosal B cell populations to produce functional anti-HIV antibodies that may contribute to protection against virus acquisition at mucosal surfaces.

  4. Epitope location for two monoclonal antibodies against human cystatin C, representing opposite aggregation inhibitory properties.

    Science.gov (United States)

    Behrendt, Izabela; Prądzińska, Martyna; Spodzieja, Marta; Kołodziejczyk, Aleksandra S; Rodziewicz-Motowidło, Sylwia; Szymańska, Aneta; Czaplewska, Paulina

    2016-07-01

    Human cystatin C (hCC), like many other amyloidogenic proteins, dimerizes and possibly makes aggregates by subdomain swapping. Inhibition of the process should suppress the fibrillogenesis leading to a specific amyloidosis (hereditary cystatin C amyloid angiopathy, HCCAA). It has been reported that exogenous agents like monoclonal antibodies against cystatin C are able to suppress formation of cystatin C dimers and presumably control the neurodegenerative disease. We have studied in detail two monoclonal antibodies (mAbs) representing very different aggregation inhibitory potency, Cyst10 and Cyst28, to find binding sites in hCC sequence responsible for the immunocomplex formation and pave the way for possible immunotherapy of HCCAA. We used the epitope extraction/excision mass spectrometry approach with the use of different enzymes complemented by affinity studies with synthetic hCC fragments as a basic technique for epitope identification. The results were analyzed in the context of hCC structure allowing us to discuss the binding sites for both antibodies. Epitopic sequences for clone Cyst28 which is a highly potent dimerization inhibitor were found in N-terminus, loop 1 and 2 (L1, L2) and fragments of β2 and β3 strands. The crucial difference between conformational epitope sequences found for both mAbs seems to be the lack of interactions with hCC via N-terminus and the loop 1 in the case of mAb Cyst10. Presumably the interactions of mAbs with hCC via L1 and β sheet fragments make the hCC structure rigid and unable to undergo the swapping process.

  5. Rapid characterization of binding specificity and cross-reactivity of antibodies using recombinant human protein arrays.

    Science.gov (United States)

    Kijanka, Gregor; Ipcho, Simon; Baars, Sabine; Chen, Hong; Hadley, Katie; Beveridge, Allan; Gould, Edith; Murphy, Derek

    2009-01-30

    Antibodies are routinely used as research tools, in diagnostic assays and increasingly as therapeutics. Ideally, these applications require antibodies with high sensitivity and specificity; however, many commercially available antibodies are limited in their use as they cross-react with non-related proteins. Here we describe a novel method to characterize antibody specificity. Six commercially available monoclonal and polyclonal antibodies were screened on high-density protein arrays comprising of ~10,000 recombinant human proteins (Imagenes). Two of the six antibodies examined; anti-pICln and anti-GAPDH, bound exclusively to their target antigen and showed no cross-reactivity with non-related proteins. However, four of the antibodies, anti-HSP90, anti-HSA, anti-bFGF and anti-Ro52, showed strong cross-reactivity with other proteins on the array. Antibody-antigen interactions were readily confirmed using Western immunoblotting. In addition, the redundant nature of the protein array used, enabled us to define the epitopic region within HSP90 of the anti-HSP90 antibody, and identify possible shared epitopes in cross-reacting proteins. In conclusion, high-density protein array technology is a fast and effective means for determining the specificity of antibodies and can be used to further improve the accuracy of antibody applications.

  6. New Monoclonal Antibodies to Defined Cell Surface Proteins on Human Pluripotent Stem Cells.

    Science.gov (United States)

    O'Brien, Carmel M; Chy, Hun S; Zhou, Qi; Blumenfeld, Shiri; Lambshead, Jack W; Liu, Xiaodong; Kie, Joshua; Capaldo, Bianca D; Chung, Tung-Liang; Adams, Timothy E; Phan, Tram; Bentley, John D; McKinstry, William J; Oliva, Karen; McMurrick, Paul J; Wang, Yu-Chieh; Rossello, Fernando J; Lindeman, Geoffrey J; Chen, Di; Jarde, Thierry; Clark, Amander T; Abud, Helen E; Visvader, Jane E; Nefzger, Christian M; Polo, Jose M; Loring, Jeanne F; Laslett, Andrew L

    2017-03-01

    The study and application of human pluripotent stem cells (hPSCs) will be enhanced by the availability of well-characterized monoclonal antibodies (mAbs) detecting cell-surface epitopes. Here, we report generation of seven new mAbs that detect cell surface proteins present on live and fixed human ES cells (hESCs) and human iPS cells (hiPSCs), confirming our previous prediction that these proteins were present on the cell surface of hPSCs. The mAbs all show a high correlation with POU5F1 (OCT4) expression and other hPSC surface markers (TRA-160 and SSEA-4) in hPSC cultures and detect rare OCT4 positive cells in differentiated cell cultures. These mAbs are immunoreactive to cell surface protein epitopes on both primed and naive state hPSCs, providing useful research tools to investigate the cellular mechanisms underlying human pluripotency and states of cellular reprogramming. In addition, we report that subsets of the seven new mAbs are also immunoreactive to human bone marrow-derived mesenchymal stem cells (MSCs), normal human breast subsets and both normal and tumorigenic colorectal cell populations. The mAbs reported here should accelerate the investigation of the nature of pluripotency, and enable development of robust cell separation and tracing technologies to enrich or deplete for hPSCs and other human stem and somatic cell types. Stem Cells 2017;35:626-640. © 2016 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  7. Broad neutralizing human monoclonal antibodies against influenza virus from vaccinated healthy donors

    Energy Technology Data Exchange (ETDEWEB)

    Kubota-Koketsu, Ritsuko; Mizuta, Hiroyuki [Department of Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871 (Japan); Oshita, Masatoshi; Ideno, Shoji [Osaka Research Laboratory, Benesis Corporation, Yodogawa-ku, Osaka 532-6505 (Japan); Yunoki, Mikihiro [Osaka Research Laboratory, Benesis Corporation, Yodogawa-ku, Osaka 532-6505 (Japan); Department of Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871 (Japan); Kuhara, Motoki [Ina Laboratory, Medical and Biological Laboratories Corporation, Ltd., Ina, Nagano 396-0002 (Japan); Yamamoto, Naomasa [Department of Biochemistry, School of Pharmaceutical Sciences, Ohu University, Koriyama, Fukushima 963-8611 (Japan); Okuno, Yoshinobu [Kanonji Institute, The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa 768-0061 (Japan); Ikuta, Kazuyoshi, E-mail: ikuta@biken.osaka-u.ac.jp [Department of Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871 (Japan)

    2009-09-11

    Human monoclonal antibodies (HuMAbs) prepared from patients with viral infections could provide information on human epitopes important for the development of vaccines as well as potential therapeutic applications. Through the fusion of peripheral blood mononuclear cells from a total of five influenza-vaccinated volunteers, with newly developed murine-human chimera fusion partner cells, named SPYMEG, we obtained 10 hybridoma clones stably producing anti-influenza virus antibodies: one for influenza A H1N1, four for influenza A H3N2 and five for influenza B. Surprisingly, most of the HuMAbs showed broad reactivity within subtype and four (two for H3N2 and two for B) showed broad neutralizing ability. Importantly, epitope mapping revealed that the two broad neutralizing antibodies to H3N2 derived from different donors recognized the same epitope located underneath the receptor-binding site of the hemagglutinin globular region that is highly conserved among H3N2 strains.

  8. Most neutralizing human monoclonal antibodies target novel epitopes requiring both Lassa virus glycoprotein subunits

    Science.gov (United States)

    Robinson, James E.; Hastie, Kathryn M.; Cross, Robert W.; Yenni, Rachael E.; Elliott, Deborah H.; Rouelle, Julie A.; Kannadka, Chandrika B.; Smira, Ashley A.; Garry, Courtney E.; Bradley, Benjamin T.; Yu, Haini; Shaffer, Jeffrey G.; Boisen, Matt L.; Hartnett, Jessica N.; Zandonatti, Michelle A.; Rowland, Megan M.; Heinrich, Megan L.; Martínez-Sobrido, Luis; Cheng, Benson; de la Torre, Juan C.; Andersen, Kristian G.; Goba, Augustine; Momoh, Mambu; Fullah, Mohamed; Gbakie, Michael; Kanneh, Lansana; Koroma, Veronica J.; Fonnie, Richard; Jalloh, Simbirie C.; Kargbo, Brima; Vandi, Mohamed A.; Gbetuwa, Momoh; Ikponmwosa, Odia; Asogun, Danny A.; Okokhere, Peter O.; Follarin, Onikepe A.; Schieffelin, John S.; Pitts, Kelly R.; Geisbert, Joan B.; Kulakoski, Peter C.; Wilson, Russell B.; Happi, Christian T.; Sabeti, Pardis C.; Gevao, Sahr M.; Khan, S. Humarr; Grant, Donald S.; Geisbert, Thomas W.; Saphire, Erica Ollmann; Branco, Luis M.; Garry, Robert F.

    2016-01-01

    Lassa fever is a severe multisystem disease that often has haemorrhagic manifestations. The epitopes of the Lassa virus (LASV) surface glycoproteins recognized by naturally infected human hosts have not been identified or characterized. Here we have cloned 113 human monoclonal antibodies (mAbs) specific for LASV glycoproteins from memory B cells of Lassa fever survivors from West Africa. One-half bind the GP2 fusion subunit, one-fourth recognize the GP1 receptor-binding subunit and the remaining fourth are specific for the assembled glycoprotein complex, requiring both GP1 and GP2 subunits for recognition. Notably, of the 16 mAbs that neutralize LASV, 13 require the assembled glycoprotein complex for binding, while the remaining 3 require GP1 only. Compared with non-neutralizing mAbs, neutralizing mAbs have higher binding affinities and greater divergence from germline progenitors. Some mAbs potently neutralize all four LASV lineages. These insights from LASV human mAb characterization will guide strategies for immunotherapeutic development and vaccine design. PMID:27161536

  9. Patterns of Human Immunodeficiency Virus type 1 recombination ex vivo provide evidence for coadaptation of distant sites, resulting in purifying selection for intersubtype recombinants during replication

    DEFF Research Database (Denmark)

    Galli, Andrea; Kearney, Mary; Nikolaitchik, Olga A

    2010-01-01

    in human populations. We hypothesize that sequence diversity affects the emergence of viable recombinants by decreasing recombination events and reducing the ability of the recombinants to replicate. To test our hypothesis, we compared recombination between two viruses containing subtype B pol genes (B....../F than in B/B viruses, and the overall distribution of crossover junctions in pol was similar for the two classes of recombinants. We then examined the emergence of recombinants in a multiple cycle assay, so that functional pol gene products were selected. We found that the emerging B/B recombinants had...

  10. Recombinant human milk proteins - an opportunity and a challenge.

    Science.gov (United States)

    Lönnerdal, B

    1996-04-01

    Several human milk proteins have physiologic functions in infants. These proteins are involved in defense against infectious agents and in the optimization of nutrient uptake from milk. Therefore, interest in producing recombinant human milk proteins to use in infant formula has been growing. Microorganisms and transgenic animals can now be used for the production of bioactive proteins. However, the benefits of each protein must be evaluated in cells, animal models, and infants before claims can be made that adding them to formula improves the health or nutrition of infants. Once benefits are shown, proper manufacturing conditions must be developed for introducing the protein or proteins into formula. Processing conditions must be evaluated to ensure that biologic activity is maintained. Dry blending, aseptic processing, sterile filtration, and other techniques will likely be necessary for introducing proteins that require specific tertiary structure for activity. The importance of posttranslational modifications must also be considered: some proteins may require proper glycosylation or phosphorylation for physiologic activity.

  11. Effects of recombinant humant erythropoietin in normal humans

    DEFF Research Database (Denmark)

    Lundby, Carsten; Olsen, Niels Vidiendal

    2011-01-01

    This review describes some of the physiological effects of recombinant human erythropoietin (EPO) in healthy humans. At the blood level EPO increases the arterial O2 content not only by increasing red blood cell volume, but also by an equally important decrease in plasma volume. Well before that...... result in suppression of endogenous EPO production through a decrease in intrarenal oxygen consumption. EPO elevates the arterial blood pressure even in healthy subjects. The receptor for EPO is present in many tissues. However, the functional effects of EPO in the skeletal muscle seem limited......, and although it has been speculated that non-erythropoietic effects of EPO (angiogenesis, shift in muscle fibre types, cognitive effects) may be responsible for the increase in exercise performance, this has not been confirmed. EPO induced haemodynamic effects call for careful monitoring during...

  12. Large Scale Generation and Characterization of Anti-Human CD34 Monoclonal Antibody in Ascetic Fluid of Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Koushan Sineh sepehr

    2013-02-01

    Full Text Available Purpose: Monoclonal antibodies or specific antibodies are now an essential tool of biomedical research and are of great commercial and medical value. The purpose of this study was to produce large scale of monoclonal antibody against CD34 in order to diagnostic application in leukemia and purification of human hematopoietic stem/progenitor cells. Methods: For large scale production of monoclonal antibody, hybridoma cells that produce monoclonal antibody against human CD34 were injected into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. 5 ml ascitic fluid was harvested from each mouse in two times. Evaluation of mAb titration was assessed by ELISA method. The ascitic fluid was examined for class and subclasses by ELISA mouse mAb isotyping Kit. mAb was purified from ascitic fluid by affinity chromatography on Protein A-Sepharose. Purity of monoclonal antibody was monitored by SDS -PAGE and the purified monoclonal antibody was conjugated with FITC. Results: Monoclonal antibodies with high specificity and sensitivity against human CD34 by hybridoma technology were prepared. The subclass of antibody was IgG1 and its light chain was kappa. Conclusion: The conjugated monoclonal antibody could be a useful tool for isolation, purification and characterization of human hematopoietic stem cells.

  13. Protection of rabbits and immunodeficient mice against lethal poxvirus infections by human monoclonal antibodies.

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    Lindsay Crickard

    Full Text Available Smallpox (variola virus is a bioweapon concern. Monkeypox is a growing zoonotic poxvirus threat. These problems have resulted in extensive efforts to develop potential therapeutics that can prevent or treat potentially lethal poxvirus infections in humans. Monoclonal antibodies (mAbs against smallpox are a conservative approach to this problem, as the licensed human smallpox vaccine (vaccinia virus, VACV primarily works on the basis of protective antibody responses against smallpox. Fully human mAbs (hmAbs against vaccinia H3 (H3L and B5 (B5R, targeting both the mature virion (MV and extracellular enveloped virion (EV forms, have been developed as potential therapeutics for use in humans. Post-exposure prophylaxis was assessed in both murine and rabbit animal models. Therapeutic efficacy of the mAbs was assessed in three good laboratory practices (GLP studies examining severe combined immunodeficiency mice (SCID given a lethal VACV infection. Pre-exposure combination hmAb therapy provided significantly better protection against disease and death than either single hmAb or vaccinia immune globulin (VIG. Post-exposure combination mAb therapy provided significant protection against disease and death, and appeared to fully cure the VACV infection in ≥50% of SCID mice. Therapeutic efficacy was then assessed in two rabbit studies examining post-exposure hmAb prophylaxis against rabbitpox (RPXV. In the first study, rabbits were infected with RPVX and then provided hmAbs at 48 hrs post-infection, or 1 hr and 72 hrs post-infection. Rabbits in both groups receiving hmAbs were 100% protected from death. In the second rabbitpox study, 100% of animal treated with combination hmAb therapy and 100% of animals treated with anti-B5 hmAb were protected. These findings suggest that combination hmAb treatment may be effective at controlling smallpox disease in immunocompetent or immunodeficient humans.

  14. Neutralization resistance of hepatitis C virus can be overcome by recombinant human monoclonal antibodies

    DEFF Research Database (Denmark)

    Pedersen, Jannie L; Carlsen, Thomas H R; Prentoe, Jannick

    2013-01-01

    Immunotherapy and vaccine development for hepatitis C virus (HCV) will depend on broadly reactive neutralizing antibodies (NAbs). However, studies in infectious strain JFH1-based culture systems expressing patient-derived Core-NS2 proteins have suggested neutralization resistance for specific HCV......-derived genotype 2a (strain T9), 2b (strains DH8 and DH10), and 2c (strain S83) consensus sequences, were viable in Huh7.5 hepatoma cells without requirement for adaptive mutations, reaching HCV infectivity titers of 3.9-4.5 log10 focus-forming units per milliliter. In in vitro neutralization assays, we...... demonstrated that the novel genotype 2 viruses as well as prototype strains J6/JFH1(2a) and J8/JFH1(2b), all with authentic envelope proteins, were resistant to neutralization by genotype 2a, 2b, 2c, 2j, 2i, and 2q patient sera. However, these patient sera had high titers of HCV-specific NAbs, because...

  15. Isolation and characterization of human monoclonal antibodies from individuals infected with West Nile Virus.

    Science.gov (United States)

    Throsby, Mark; Geuijen, Cecile; Goudsmit, Jaap; Bakker, Arjen Q; Korimbocus, Jehanara; Kramer, R Arjen; Clijsters-van der Horst, Marieke; de Jong, Maureen; Jongeneelen, Mandy; Thijsse, Sandra; Smit, Renate; Visser, Therese J; Bijl, Nora; Marissen, Wilfred E; Loeb, Mark; Kelvin, David J; Preiser, Wolfgang; ter Meulen, Jan; de Kruif, John

    2006-07-01

    Monoclonal antibodies (MAbs) neutralizing West Nile Virus (WNV) have been shown to protect against infection in animal models and have been identified as a correlate of protection in WNV vaccine studies. In the present study, antibody repertoires from three convalescent WNV-infected patients were cloned into an scFv phage library, and 138 human MAbs binding to WNV were identified. One hundred twenty-one MAbs specifically bound to the viral envelope (E) protein and four MAbs to the premembrane (prM) protein. Enzyme-linked immunosorbent assay-based competitive-binding assays with representative E protein-specific MAbs demonstrated that 24/51 (47%) bound to domain II while only 4/51 (8%) targeted domain III. In vitro neutralizing activity was demonstrated for 12 MAbs, and two of these, CR4374 and CR4353, protected mice from lethal WNV challenge at 50% protective doses of 12.9 and 357 mug/kg of body weight, respectively. Our data analyzing three infected individuals suggest that the human anti-WNV repertoire after natural infection is dominated by nonneutralizing or weakly neutralizing MAbs binding to domain II of the E protein, while domain III-binding MAbs able to potently neutralize WNV in vitro and in vivo are rare.

  16. Strategies to Obtain Diverse and Specific Human Monoclonal Antibodies From Transgenic Animals.

    Science.gov (United States)

    Brüggemann, Marianne; Osborn, Michael J; Ma, Biao; Buelow, Roland

    2017-08-01

    Techniques to obtain large quantities of antigen-specific monoclonal antibodies (mAbs) were first established in the 1970s when Georges Köhler and César Milstein immortalized antibody-producing mouse B-lymphocytes by fusion with myeloma cells (http://www.whatisbiotechnology.org/exhibitions/milstein). Combined with the expression of human antibodies in transgenic animals, this technique allowed upon immunization the generation of highly specific fully human mAbs for therapeutic applications. Apart from being extremely beneficial, mAbs are a huge success commercially. However, despite cell fusion generating many useful mAbs questions have been asked about which types of cells are prone to fuse and whether other methods may identify a wider range of binders. The discovery that expression libraries, using Escherichia coli or yeast, produced different specificities was intriguing and more recently Next-Generation Sequencing has identified wide-ranging usage with highly diverse and unique repertoires. Another strategy is the combination of flow cytometry sorting of antigen-binding B lymphocytes and single-cell reverse transcription polymerase chain reaction followed by reexpression, which has identified many high-affinity mAbs.

  17. Monoclonal Antibodies to the Human Insulin Receptor that Activate Glucose Transport but not Insulin Receptor Kinase Activity

    Science.gov (United States)

    Forsayeth, John R.; Caro, Jose F.; Sinha, Madhur K.; Maddux, Betty A.; Goldfine, Ira D.

    1987-05-01

    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.

  18. Monoclonal Antibodies.

    Science.gov (United States)

    Killington, R. A.; Powell, K. L.

    1984-01-01

    Monoclonal antibodies have provided an exciting addition to the "armory" of the molecular biologist and immunologist. This article discusses briefly the concept of, techniques available for, production of, and possible uses of monoclonal antibodies. (Author)

  19. Biosynthesis of the precursor of a soluble human insulin receptor ectodomain in insect Sf9 cells infected with a recombinant baculovirus.

    Science.gov (United States)

    Sissom, J F; Ellis, L

    1991-06-14

    In contrast to transfected mammalian cells, insect Sf9 cells infected with a recombinant Baculovirus inefficiently process and secrete a soluble derivative of the extracellular domain of the human insulin receptor. The high-mannose form of the receptor precursor that accumulates intracellularly is not grossly aberrant or malfolded, as its interaction with a diverse panel of monoclonal antibodies are comparable to secreted precursor and proteolytically processed receptor, both of which bear partially trimmed oligosaccharide chains. Thus the inefficient step in the biosynthesis of this protein in Sf9 cells is either at, or just preceding, the trimming of its high-mannose oligosaccharide chains.

  20. Generation and characterization of cross neutralizing human monoclonal antibody against 4 serotypes of dengue virus without enhancing activity

    Directory of Open Access Journals (Sweden)

    Subenya Injampa

    2017-11-01

    Full Text Available Background Dengue disease is a leading cause of illness and death in the tropics and subtropics. Most severe cases occur among patients secondarily infected with a different dengue virus (DENV serotype compared with that from the first infection, resulting in antibody-dependent enhancement activity (ADE. Our previous study generated the neutralizing human monoclonal antibody, D23-1B3B9 (B3B9, targeting the first domain II of E protein, which showed strong neutralizing activity (NT against all four DENV serotypes. However, at sub-neutralizing concentrations, it showed ADE activity in vitro. Methods In this study, we constructed a new expression plasmid using the existing IgG heavy chain plasmid as a template for Fc modification at position N297Q by site-directed mutagenesis. The resulting plasmid was then co-transfected with a light chain plasmid to produce full recombinant IgG (rIgG in mammalian cells (N297Q-B3B9. This rIgG was characterized for neutralizing and enhancing activity by using different FcγR bearing cells. To produce sufficient quantities of B3B9 rIgG for further characterization, CHO-K1 cells stably secreting N297Q-B3B9 rIgG were then established. Results The generated N297Q-B3B9 rIgG which targets the conserved N-terminal fusion loop of DENV envelope protein showed the same cross-neutralizing activity to all four DENV serotypes as those of wild type rIgG. In both FcγRI- and RII-bearing THP-1 cells and FcγRII-bearing K562 cells, N297Q-B3B9 rIgG lacked ADE activity against all DENV serotypes at sub-neutralizing concentrations. Fortunately, the N297Q-B3B9 rIgG secreted from stable cells showed the same patterns of NT and ADE activities as those of the N297Q-B3B9 rIgG obtained from transient expression against DENV2. Thus, the CHO-K1 stably expressing N297Q-B3B9 HuMAb can be developed as high producer stable cells and used to produce sufficient amounts of antibody for further characterization as a promising dengue therapeutic

  1. Genetic recombination between human and animal parasites creates novel strains of human pathogen.

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    Wendy Gibson

    2015-03-01

    Full Text Available Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr responsible for sleeping sickness (Human African Trypanosomiasis, HAT in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

  2. Screening of anti-human leukocyte monoclonal antibodies for reactivity with equine leukocytes.

    Science.gov (United States)

    Ibrahim, Sherif; Saunders, Kelly; Kydd, Julia H; Lunn, D Paul; Steinbach, Falko

    2007-09-15

    Three hundred and seventy-nine monoclonal antibodies (mAbs) against various human CD molecules supplied to the HLDA8 animal homologues section (including four isotype controls) were analysed for cross-reactivity with equine leukocytes. First, flow cytometric identification of positively reacting mAbs was performed in one laboratory. Thereafter, a second round of flow cytometric evaluation was performed, involving three laboratories participating in the study. The first test-round indicated 17 mAbs as potentially positive. After the second round of flow cytometric analysis, 14 mAbs remained (directed against CD2, CD11a, CD18, CD44, CD45, CD49d, CD91, CD163 and CD172) where cross-reactivity was anticipated based on similarities between the human and equine staining pattern. Additionally, there was 1 mAb with weak likely positive reactivity, 12 mAbs with positive staining, which likely do not reflect valuable data, 5 mAbs with clear alternate expression pattern from that expected from humans, 5 mAbs with a questionable staining pattern itself, i.e. that was variable between the three labs, 32 mAbs with weak-positive expression and alternate staining pattern, and 279 negative mAbs (including the four isotype controls) were detected. In 31 cases, more appropriate target cells, such as thymocytes or stem cells, were not available for the screening. The results underline the value of this "cross-reactivity" approach for equine immunology. However, as only a few mAbs against leukocyte surface antigens reacted positively (approximately 4% of the mAbs submitted), the analysis of further anti-human mAbs and directed efforts to develop species-specific anti-CD mAb are still required.

  3. A neutralizing human monoclonal antibody protects African Green monkeys from Hendra virus challenge

    Science.gov (United States)

    Bossart, Katharine N.; Geisbert, Thomas W.; Feldmann, Heinz; Zhu, Zhongyu; Feldmann, Friederike; Geisbert, Joan B.; Yan, Lianying; Feng, Yan-Ru; Brining, Doug; Scott, Dana; Wang, Yanping; Dimitrov, Antony S.; Callison, Julie; Chan, Yee-Peng; Hickey, Andrew C.; Dimitrov, Dimiter S.; Broder, Christopher C.; Rockx, Barry

    2012-01-01

    Hendra virus (HeV) is a recently emerged zoonotic paramyxovirus that can cause a severe and often fatal disease in horses and humans. HeV is categorized as a biosafety level 4 agent, which has made the development of animal models and testing of potential therapeutics and vaccines challenging. Infection of African Green monkeys (AGMs) with HeV was recently demonstrated and disease mirrored fatal HeV infection in humans, manifesting as a multisystemic vasculitis with widespread virus replication in vascular tissues and severe pathologic manifestations in the lung, spleen and brain. Here, we demonstrate that m102.4, a potent HeV neutralizing human monoclonal antibody (hmAb), can protect AGMs from disease post infection (p.i.) with HeV. Fourteen AGMs were challenged intratracheally with a lethal dose of HeV and twelve subjects were infused twice with a 100 mg dose of m102.4 beginning at either 10 hr, 24 hr or 72 hr p.i. and again approximately 48 hrs later. The presence of viral RNA, infectious virus and HeV-specific immune responses demonstrated that all subjects were infected following challenge. All twelve AGMs that received m102.4 survived infection; whereas the untreated control subjects succumbed to disease on day 8 p.i.. Animals in the 72 hr treatment group exhibited neurological signs of disease but all animals started to recover by day 16 p.i.. These results represent successful post-exposure in vivo efficacy by an investigational drug against HeV and highlight the potential impact a hmAb can have on human disease. PMID:22013123

  4. Comparison of 5 monoclonal antibodies for immunopurification of human butyrylcholinesterase on Dynabeads: KD values, binding pairs, and amino acid sequences.

    Science.gov (United States)

    Peng, Hong; Brimijoin, Stephen; Hrabovska, Anna; Targosova, Katarina; Krejci, Eric; Blake, Thomas A; Johnson, Rudolph C; Masson, Patrick; Lockridge, Oksana

    2015-10-05

    Human butyrylcholinesterase (HuBChE) is a stoichiometric bioscavenger of nerve agents and organophosphorus pesticides. Mass spectrometry methods detect stable nerve agent adducts on the active site serine of HuBChE. The first step in sample preparation is immunopurification of HuBChE from plasma. Our goal was to identify monoclonal antibodies that could be used to immunopurify HuBChE on Dynabeads Protein G. Mouse anti-HuBChE monoclonal antibodies were obtained in the form of ascites fluid, dead hybridoma cells stored frozen at -80 °C for 30 years, or recently frozen hybridoma cells. RNA from 4 hybridoma cell lines was amplified by PCR for determination of their nucleotide and amino acid sequences. Full-length light and heavy chains were expressed, and the antibodies purified from culture medium. A fifth monoclonal was purchased. The 5 monoclonal antibodies were compared for ability to capture HuBChE from human plasma on Dynabeads Protein G. In addition, they were evaluated for binding affinity by Biacore and ELISA. Epitope mapping by pairing analysis was performed on the Octet Red96 instrument. The 5 monoclonal antibodies, B2 12-1, B2 18-5, 3E8, mAb2, and 11D8, had similar KD values of 10(-9) M for HuBChE. Monoclonal B2 18-5 outperformed the others in the Dynabeads Protein G assay where it captured 97% of the HuBChE in 0.5 ml plasma. Pairing analysis showed that 3E8 and B2 12-1 share the same epitope, 11D8 and B2 18-5 share the same epitope, but mAb2 and B2 12-1 or mAb2 and 3E8 bind to different epitopes on HuBChE. B2 18-5 was selected for establishment of a stable CHO cell line for production of mouse anti-HuBChE monoclonal. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Biological evaluation of recombinant human erythropoietin in pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Ramos A.S.

    2003-01-01

    Full Text Available The potencies of mammalian cell-derived recombinant human erythropoietin pharmaceutical preparations, from a total of five manufacturers, were assessed by in vivo bioassay using standardized protocols. Eight-week-old normocythemic mice received a single subcutaneous injection followed by blood sampling 96 h later or multiple daily injections with blood sampling 24 h after the last injection. Reticulocyte counting by microscopic examination was employed as the end-point using the brilliant cresyl blue or selective hemolysis methods, together with automated flow cytometry. Different injection schedules were investigated and dose-response curves for the European Pharmacopoeia Biological Reference Preparation of erythropoietin were compared. Manual and automated methods of reticulocyte counting were correlated with respect to assay validity and precision. Using 8 mice per treatment group, intra-assay precision determined for all of the assays in the study showed coefficients of variation of 12.1-28.4% for the brilliant cresyl blue method, 14.1-30.8% for the selective hemolysis method and 8.5-19.7% for the flow cytometry method. Applying the single injection protocol, a combination of at least two independent assays was required to achieve the precision potency and confidence limits indicated by the manufacturers, while the multiple daily injection protocol yielded the same acceptable results within a single assay. Although the latter protocol using flow cytometry for reticulocyte counting gave more precise and reproducible results (intra-assay coefficients of variation: 5.9-14.2%, the well-characterized manual methods provide equally valid alternatives for the quality control of recombinant human erythropoietin therapeutic products.

  6. Identification and characterization of a broadly cross-reactive HIV-1 human monoclonal antibody that binds to both gp120 and gp41.

    Directory of Open Access Journals (Sweden)

    Mei-Yun Zhang

    Full Text Available Identification of broadly cross-reactive HIV-1-neutralizing antibodies (bnAbs may assist vaccine immunogen design. Here we report a novel human monoclonal antibody (mAb, designated m43, which co-targets the gp120 and gp41 subunits of the HIV-1 envelope glycoprotein (Env. M43 bound to recombinant gp140 s from various primary isolates, to membrane-associated Envs on transfected cells and HIV-1 infected cells, as well as to recombinant gp120 s and gp41 fusion intermediate structures containing N-trimer structure, but did not bind to denatured recombinant gp140 s and the CD4 binding site (CD4bs mutant, gp120 D368R, suggesting that the m43 epitope is conformational and overlaps the CD4bs on gp120 and the N-trimer structure on gp41. M43 neutralized 34% of the HIV-1 primary isolates from different clades and all the SHIVs tested in assays based on infection of peripheral blood mononuclear cells (PBMCs by replication-competent virus, but was less potent in cell line-based pseudovirus assays. In contrast to CD4, m43 did not induce Env conformational changes upon binding leading to exposure of the coreceptor binding site, enhanced binding of mAbs 2F5 and 4E10 specific for the membrane proximal external region (MPER of gp41 Envs, or increased gp120 shedding. The overall modest neutralization activity of m43 is likely due to the limited binding of m43 to functional Envs which could be increased by antibody engineering if needed. M43 may represent a new class of bnAbs targeting conformational epitopes overlapping structures on both gp120 and gp41. Its novel epitope and possibly new mechanism(s of neutralization could helpdesign improved vaccine immunogens and candidate therapeutics.

  7. Novel Monoclonal Antibodies Recognizing Human Prostate-Specific Membrane Antigen (PSMA) as Research and Theranostic Tools.

    Science.gov (United States)

    Nováková, Zora; Foss, Catherine A; Copeland, Benjamin T; Morath, Volker; Baranová, Petra; Havlínová, Barbora; Skerra, Arne; Pomper, Martin G; Barinka, Cyril

    2017-05-01

    Prostate-specific membrane antigen (PSMA) is a validated target for the imaging and therapy of prostate cancer. Here, we report the detailed characterization of four novel murine monoclonal antibodies (mAbs) recognizing human PSMA as well as PSMA orthologs from different species. Performance of purified mAbs was assayed using a comprehensive panel of in vitro experimental setups including Western blotting, immunofluorescence, immunohistochemistry, ELISA, flow cytometry, and surface-plasmon resonance. Furthermore, a mouse xenograft model of prostate cancer was used to compare the suitability of the mAbs for in vivo applications. All mAbs demonstrate high specificity for PSMA as documented by the lack of cross-reactivity to unrelated human proteins. The 3F11 and 1A11 mAbs bind linear epitopes spanning residues 226-243 and 271-288 of human PSMA, respectively. 3F11 is also suitable for the detection of PSMA orthologs from mouse, pig, dog, and rat in experimental setups where the denatured form of PSMA is used. 5D3 and 5B1 mAbs recognize distinct surface-exposed conformational epitopes and are useful for targeting PSMA in its native conformation. Most importantly, using a mouse xenograft model of prostate cancer we show that both the intact 5D3 and its Fab fragment are suitable for in vivo imaging. With apparent affinities of 0.14 and 1.2 nM as determined by ELISA and flow cytometry, respectively, 5D3 has approximately 10-fold higher affinity for PSMA than the clinically validated mAb J591 and, therefore, is a prime candidate for the development of next-generation theranostics to target PSMA. Prostate 77:749-764, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Human Cell Line-Derived Monoclonal IgA Antibodies for Cancer Immunotherapy

    Directory of Open Access Journals (Sweden)

    Felix Hart

    2017-05-01

    Full Text Available IgA antibodies have great potential to improve the functional diversity of current IgG antibody-based cancer immunotherapy options. However, IgA production and purification is not well established, which can at least in part be attributed to the more complex glycosylation as compared to IgG antibodies. IgA antibodies possess up to five N-glycosylation sites within their constant region of the heavy chain as compared to one site for IgG antibodies. The human GlycoExpress expression system was developed to produce biotherapeutics with optimized glycosylation and used here to generate a panel of IgA isotype antibodies directed against targets for solid (TA-mucin 1, Her2, EGFR, Thomsen–Friedenreich and hematological (CD20 cancer indications. The feasibility of good manufacturing practice was shown by the production of 11 g IgA within 35 days in a one liter perfusion bioreactor, and IgA antibodies in high purity were obtained after purification. The monoclonal IgA antibodies possessed a high sialylation degree, and no non-human glycan structures were detected. Kinetic analysis revealed increased avidity antigen binding for IgA dimers as compared to monomeric antibodies. The IgA antibodies exhibited potent Fab- and Fc-mediated functionalities against cancer cell lines, whereby especially granulocytes are recruited. Therefore, for patients who do not sufficiently benefit from therapeutic IgG antibodies, IgA antibodies may complement current regiment options and represent a promising strategy for cancer immunotherapy. In conclusion, a panel of novel biofunctional IgA antibodies with human glycosylation was successfully generated.

  9. Radioimmunoassay of bovine, ovine and porcine luteinizing hormone with a monoclonal antibody and a human tracer

    Energy Technology Data Exchange (ETDEWEB)

    Fosberg, M.; Tagle, R.; Madej, A.; Molina, J.R.; Carlsson, M.-A.

    1993-01-01

    A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human [sup 125]ILH tracer from a commercial kit and a monoclonal antibody (518B7) specific for LH but with low species specificity. Standard curves demonstrated similar binding kinetics when bLH, oLH and pLH were incubated with tracer and antibody for 2 h at room temperature. A 30-min delay in the addition of the tracer gave sufficient sensitivity when analysing pLH. Separation of antibody-bound LH from free hormone was achieved by using second antibody-coated micro Sepharose beads. The assay was validated and the performance compared with that of an RIA currently in use for determination of bLH (coefficient of correlation: 0.99 and 0.98). Regardless of the standards used, intra-assay coefficients of variation were <10% for LH concentrations exceeding 1 [mu]g/L. The inter-assay coefficients of variation were <15%. The assay was used for clinical evaluation demonstrating the pre-ovulatory LH surge in two cyclic cows, LH pulsatility in an oophorectomized ewe and LH response to GnRH injection in a boar. (au) (7 refs.).

  10. Preparative purification of human monoclonal antibody isoforms in a multi-compartment electrolyser with immobiline membranes.

    Science.gov (United States)

    Righetti, P G; Wenisch, E; Jungbauer, A; Katinger, H; Faupel, M

    1990-02-02

    The performance of a multi-compartment electrolyser with isoelectric Immobiline membranes for large-scale protein purification is evaluated. Owing to the presence of isoelectric membranes possessing a high buffering capacity and ionic strength, isoelectric protein precipitation inside the membranes, one of the major drawbacks of present membrane uses, is fully avoided. In addition, owing to this novel membrane technology, pH gradient decay, typical of isoelectric focusing in carrier ampholytes, is fully eliminated and pH and conductivity constancy is guaranteed in all flow chambers for running periods of more than 11 days (160,000 V h). The membranes described possess a unique selectivity, in that they act by modulating the surface charge (i.e., the mobility) of macroions crossing or tangential to them. The concept of isoelectric Immobiline membranes acting like a pH-stat unit is introduced. Protein homogeneity in each chamber of the electrolyser can be achieved even when purifying human monoclonal antibodies against HIV-1, which possess high pI values (9.0-9.6), are large molecules (Mr 150,000) and are fractionated in the presence of large micelles of neutral detergents.

  11. Pharmacology and placental transfer of a human alphav integrin monoclonal antibody in rabbits.

    Science.gov (United States)

    Martin, Pauline L; Zhou, Zhao; Van den Bulck, Kathleen; Kwok, Deborah; Powers, Gordon; Jiao, Qun; Schantz, Allen; Treacy, George

    2010-04-01

    Intetumumab is a human IgG1 anti-alphav-integrin monoclonal antibody that inhibits angiogenesis. Integrin binding and angiogenesis are important in reproduction including fertilization, implantation, and embryofetal development. These studies were designed to determine the pharmacological relevance of the rabbit for the evaluation of potential effects on embryofetal development and to evaluate the placental transfer of intetumumab in rabbits. In vitro pharmacology studies evaluated the binding of intetumumab to rabbit cells and the inhibition of vessel sprouting from rabbit aorta. For the evaluation of placental transfer, pregnant rabbits (8/group) were injected intravenously with intetumumab 50 or 100 mg/kg every 2 days from Gestation Day (GD)7 to GD19. Maternal sera, fetal homogenates/sera, and amniotic fluid were collected at necropsy on GD19 or GD28 for evaluation of intetumumab concentrations. Clinical condition of the dams was monitored and fetuses were screened for abnormalities. Intetumumab (5-40 microg/mL) inhibited aortic cell adhesion to vitronectin and vessel sprouting from rabbit aortic rings. Immunohistochemical staining of rabbit tissues demonstrated binding of intetumumab to placenta. Administration of intetumumab to pregnant rabbits was well tolerated by the dams and the fetuses did not show major abnormalities. Fetal exposure to intetumumab relative to maternal exposure was rabbit is a pharmacologically relevant species for evaluation of potential developmental effects of intetumumab. Intetumumab crosses the rabbit placenta during the fetal period (GD 19-28). 2010 Wiley-Liss, Inc.

  12. Utilisation of tracer monoclonal antibodies for the immunoscintigraphic detection of human colorectal cancers

    Energy Technology Data Exchange (ETDEWEB)

    Chatal, J.F.; Douillard, J.Y.; Kremer, M.; Curtet, C.; Le Mevel, B. (INSERM, Faculte de Medecine, Nantes (France)); Fumoleau, P. (Centre Rene Gauducheau, Nantes (France)); Bourdoiseau, M. (Office des Rayonnements Ionisants, CEA Saclay, Gif-sur-Yvette (France))

    1983-01-01

    Two monoclonal antibodies, 17-1A and 19-9, with recognized human gastrointestinal cancers in cell cultures, were labeled with iodine 131 for immunoscintigraphic application. With the intact /sup 131/I-17-1A antibody, 21 out of 35 (60%) primary or secondary colorectal cancer sites were visualized, whereas all 21 nonepitheliomatous colic cancer sites or noncolic cancer sites were negative. With F(ab')/sub 2/ fragments of the 19-9 antibody, 18 out of 27 (67%) colorectal cancer sites were positive. With both radioantibodies, the bestly contrasted tumor images were late, 4 to 5 days after injection. A study with paired-label technique, associating a specific iodine-131-labeled antibody with a non-specific iodine-125-labeled immunoglobulin, demonstrated, that tumor uptake was indeed specific for the 17-1A or 19-9 antibody in tumor and normal colon fragments obtained during operations on 4 patients. A preliminary prospective study showed that only immunoscintigraphy was able to confirm and localize a recurrence of rectal cancer in one patient. A larger series will be necessary to validate the clinical benefit of the technique, as compared with the results of other diagnostic techniques, before immunoscintigraphy can be proposed for routine clinical use.

  13. Comparison of Recombinant Human Haptocorrin Expressed in Human Embryonic Kidney Cells and Native Haptocorrin

    DEFF Research Database (Denmark)

    Furger, Evelyne; Fedosov, Sergey N; Lildballe, Dorte Launholt

    2012-01-01

    HC, that compared to native HC contains four excessive amino acids (…LVPR) at the C-terminus, showed subtle changes in the binding kinetics of Cbl, cobinamide and the fluorescent Cbl conjugate CBC. The recombinant protein has properties very similar to native HC and although showing slightly different ligand......Haptocorrin (HC) is a circulating corrinoid binding protein with unclear function. In contrast to transcobalamin, the other transport protein in blood, HC is heavily glycosylated and binds a variety of cobalamin (Cbl) analogues. HC is present not only in blood but also in various secretions like...... milk, tears and saliva. No recombinant form of HC has been described so far. We report the expression of recombinant human HC (rhHC) in human embryonic kidney cells. We purified the protein with a yield of 6 mg (90 nmol) per litre of cell culture supernatant. The isolated rhHC behaved as native HC...

  14. Monoclonal antibody binding to the macrophage-specific receptor sialoadhesin alters the phagocytic properties of human and mouse macrophages.

    Science.gov (United States)

    De Schryver, Marjorie; Cappoen, Davie; Elewaut, Dirk; Nauwynck, Hans J; Maes, Louis; Caljon, Guy; Cos, Paul; Delputte, Peter L

    2017-02-01

    Sialoadhesin (Sn) is a surface receptor expressed on macrophages in steady state conditions, but during inflammation, Sn can be upregulated both on macrophages and on circulating monocytes. It was shown for different species that Sn becomes internalized after binding with monoclonal antibodies. These features suggest that Sn is a potential target for immunotherapies. In this study, human and mouse macrophages were treated with anti-Sn monoclonal antibodies or F(ab')2 fragments and the effect of their binding to Sn on phagocytosis was analyzed. Binding of antibodies to Sn resulted in delayed and reduced phagocytosis of fluorescent beads. No effect was observed on Fc-mediated phagocytosis or phagocytosis of bacteria by human macrophages. In contrast, an enhanced phagocytosis of bacteria by mouse macrophages was detected. These results showed that stimulation of Sn could have different effects on macrophage phagocytosis, depending both on the type of phagocytosis and cellular background. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Characterization of a Novel Anti-Human HB-EGF Monoclonal Antibody Applicable for Paraffin-Embedded Tissues and Diagnosis of HB-EGF-Related Cancers.

    Science.gov (United States)

    Iwamoto, Ryo; Takagi, Mika; Akatsuka, Jun-Ichi; Ono, Ken-Ichiro; Kishi, Yoshiro; Mekada, Eisuke

    2016-04-01

    Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family of growth factors that bind to and activate the EGF receptor (EGFR/ErbB1) and ErbB4. HB-EGF plays pivotal roles in pathophysiological processes, including cancer. Thus, monoclonal antibodies (mAbs) for HB-EGF detection could be an important tool in the therapeutic diagnosis of HB-EGF-related cancers and other diseases. However, few mAbs, especially those applicable for immunohistochemistry (IHC), have been established to date. In this study, we generated a clone of hybridoma-derived mAb 2-108 by immunizing mice with recombinant human HB-EGF protein expressed by human cells. The mAb 2-108 specifically bound to human HB-EGF but not to mouse HB-EGF and was successful in immunoblotting, even under reducing conditions, immunoprecipitation, and immunofluorescence for unfixed as well as paraformaldehyde-fixed cells. Notably, this mAb was effective in IHC of paraffin-embedded tumor specimens. Epitope mapping analysis showed that mAb 2-108 recognized the N-terminal prodomain in HB-EGF. These results indicate that this new anti-HB-EGF mAb 2-108 would be useful in the diagnosis of HB-EGF-related cancers and would be a strong tool in both basic and clinical research on HB-EGF.

  16. Characterisation of new monoclonal antibodies reacting with prions from both human and animal brain tissues.

    Science.gov (United States)

    Cordes, Henriette; Bergström, Ann-Louise; Ohm, Jakob; Laursen, Henning; Heegaard, Peter M H

    2008-09-15

    Post-mortem diagnosis of transmissible spongiform encephalopathies (prion diseases) is primarily based on the detection of a protease resistant, misfolded disease associated isoform (PrP(Sc)) of the prion protein (PrP(C)) on neuronal cells. These methods depend on antibodies directed against PrP(C) and capable of reacting with PrP(Sc)in situ (immunohistochemistry on nervous tissue sections) or with the unfolded form of the protein (western and paraffin embedded tissue (PET) blotting). Here, high-affinity monoclonal antibodies (mAbs 1.5D7, 1.6F4) were produced against synthetic PrP peptides in wild-type mice and used for western blotting and immunohistochemistry to detect several types of human prion-disease associated PrP(Sc), including sporadic Creutzfeldt-Jakob Disease (CJD) (subtypes MM1 and VV2), familial CJD and Gerstmann-Sträussler-Scheinker (GSS) disease PrP(Sc) as well as PrP(Sc) of bovine spongiform encephalopathy (bovine brain), scrapie (ovine brain) and experimental scrapie in hamster and in mice. The antibodies were also used for PET-blotting in which PrP(Sc) blotted from brain tissue sections onto a nitrocellulose membrane is visualized with antibodies after protease and denaturant treatment allowing the detection of protease resistant PrP forms (PrP(RES)) in situ. Monoclonal antibodies 1.5D7 and 1.6F4 were raised against the reported epitope (PrP153-165) of the commercial antibody 6H4. While 1.5D7 and 1.6F4 were completely inhibitable by PrP153-165, 6H4 was not, indicating that the specificity of 6H4 is not defined completely by PrP153-165. The two antibodies performed similarly to 6H4 in western blotting with human samples, but showed less reactivity and enhanced background staining with animal samples in this method. In immunohistochemistry 1.5D7 and 1.6F4 performed better than 6H4 suggesting that the binding affinity of 1.5D7 and 1.6F4 with native (aggregated) PrP(Sc)in situ was higher than that of 6H4. On the other hand in PET-blotting, 6H4

  17. Neutralization of Zika virus by germline-like human monoclonal antibodies targeting cryptic epitopes on envelope domain III

    OpenAIRE

    Wu, Yanling; Li, Shun; Du, Lanying; Wang, Chunyu; Zou, Peng; Hong, Binbin; Yuan, Mengjiao; Ren, Xiaonan; Tai, Wanbo; Kong, Yu; Zhou, Chen; Lu, Lu; Zhou, Xiaohui; Jiang, Shibo; Ying, Tianlei

    2017-01-01

    The Zika virus (ZIKV), a flavivirus transmitted by Aedes mosquitoes, has emerged as a global public health concern. Pre-existing cross-reactive antibodies against other flaviviruses could modulate immune responses to ZIKV infection by antibody-dependent enhancement, highlighting the importance of understanding the immunogenicity of the ZIKV envelope protein. In this study, we identified a panel of human monoclonal antibodies (mAbs) that target domain III (DIII) of the ZIKV envelope protein fr...

  18. Myostatin blockade with a fully human monoclonal antibody induces muscle hypertrophy and reverses muscle atrophy in young and aged mice

    OpenAIRE

    Latres, Esther; Pangilinan, Jeffrey; Miloscio, Lawrence; Bauerlein, Roy; Na, Erqian; Potocky, Terra B.; Huang, Ying; Eckersdorff, Mark; Rafique, Ashique; Mastaitis, Jason; Lin, Calvin; Murphy, Andrew J.; Yancopoulos, George D.; Gromada, Jesper; Stitt, Trevor

    2015-01-01

    Background Loss of skeletal muscle mass and function in humans is associated with significant morbidity and mortality. The role of myostatin as a key negative regulator of skeletal muscle mass and function has supported the concept that inactivation of myostatin could be a useful approach for treating muscle wasting diseases. Methods We generated a myostatin monoclonal blocking antibody (REGN1033) and characterized its effects in vitro using surface plasmon resonance biacore and cell-based Sm...

  19. Short-term effects of recombinant human growth hormone and feeding on gluconeogenesis in humans

    Science.gov (United States)

    After a short-term fast, lactating women have increased rates of glucose production but not gluconeogenesis (GNG) despite relative hypoinsulinemia. We explored the effects of non-insulin-dependent increase in glucose utilization and recombinant human growth hormone (rhGH) on glucose production, glyc...

  20. Expression and characterization of recombinant soluble porcine CD3 ectodomain molecules: Mapping the epitope of an anti-porcine CD3 monoclonal antibody 898H2-6-15

    OpenAIRE

    Peraino, Jaclyn Stromp; Hermanrud, Christina E.; Springett, Lauren; Zhang, Huiping; Li, Guoying; Srinivasan, Srimathi; Gusha, Ashley; Sachs, David H.; Huang, Christene A.; Wang, Zhirui

    2012-01-01

    The porcine CD3 specific monoclonal antibody 898H2-6-15 has been used in allo- and xeno-transplantation studies as a porcine CD3 marker and as an effective T cell depletion reagent when conjugated to the diphtheria toxin mutant, CRM9. A recombinant anti-porcine CD3 immuntoxin was recently developed using single-chain variable fragments (scFv) derived from 898H2-6-15. In this study, using published sequence data, we have expressed the porcine CD3 ectodomain molecules in E. coli through inclusi...

  1. Anti-leukemic activity and tolerability of anti-human CD47 monoclonal antibodies.

    Science.gov (United States)

    Pietsch, E C; Dong, J; Cardoso, R; Zhang, X; Chin, D; Hawkins, R; Dinh, T; Zhou, M; Strake, B; Feng, P-H; Rocca, M; Santos, C Dos; Shan, X; Danet-Desnoyers, G; Shi, F; Kaiser, E; Millar, H J; Fenton, S; Swanson, R; Nemeth, J A; Attar, R M

    2017-02-24

    CD47, a broadly expressed cell surface protein, inhibits cell phagocytosis via interaction with phagocyte-expressed SIRPα. A variety of hematological malignancies demonstrate elevated CD47 expression, suggesting that CD47 may mediate immune escape. We discovered three unique CD47-SIRPα blocking anti-CD47 monoclonal antibodies (mAbs) with low nano-molar affinity to human and cynomolgus monkey CD47, and no hemagglutination and platelet aggregation activity. To characterize the anti-cancer activity elicited by blocking CD47, the mAbs were cloned into effector function silent and competent Fc backbones. Effector function competent mAbs demonstrated potent activity in vitro and in vivo, while effector function silent mAbs demonstrated minimal activity, indicating that blocking CD47 only leads to a therapeutic effect in the presence of Fc effector function. A non-human primate study revealed that the effector function competent mAb IgG1 C47B222-(CHO) decreased red blood cells (RBC), hematocrit and hemoglobin by >40% at 1 mg/kg, whereas the effector function silent mAb IgG2σ C47B222-(CHO) had minimal impact on RBC indices at 1 and 10 mg/kg. Taken together, our findings suggest that targeting CD47 is an attractive therapeutic anti-cancer approach. However, the anti-cancer activity observed with anti-CD47 mAbs is Fc effector dependent as are the side effects observed on RBC indices.

  2. Increasing the Stability of Recombinant Human Green Cone Pigment.

    Science.gov (United States)

    Owen, Timothy S; Salom, David; Sun, Wenyu; Palczewski, Krzysztof

    2018-01-10

    Three types of cone cells exist in the human retina, each containing a different pigment responsible for the initial step of photo-transduction. These pigments are distinguished by their specific absorbance maxima, 425 nm (blue), 530 nm (green) and 560 nm (red). Each pigment contains a common chromophore, 11-cis-retinal covalently bound to an opsin protein via a Schiff base. The 11-cis-retinal protonated Schiff base has an absorbance maxima at 440 nm in methanol. Unfortunately, the chemistry allowing the same chromophore interacting with different opsin proteins to tune the absorbance of the resulting pigments to distinct λmax values is poorly understood. Rhodopsin is the only pigment with a native structure determined at high resolution. Homology models for cone pigments have been generated, but experimentally determined structures are needed for a precise understanding of spectral tuning. The principal obstacle to solving the structures of cone pigments has been their innate instability in recombinant constructs. By inserting five different thermo-stabilizing proteins, BRIL, T4L, PGS, RUB and FLAV, into the recombinant green opsin sequence, constructs were created that were up to 9-fold more stable than WT. Using cellular retinaldehyde-binding protein (CRALBP), we developed a quick means of assessing the stability of the green pigment. CRALBP testing also confirmed a further 48-fold increase in pigment stability when varying the detergent used. These results suggest an efficient protocol for routine purification and stabilization of cone pigments that could be used for high-resolution determination of their structures as well as for other studies.

  3. Recombinant production of human interleukin 6 in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Henrik Nausch

    Full Text Available In this study, we compared basic expression approaches for the efficient expression of bioactive recombinant human interleukin-6 (IL6, as an example for a difficult-to-express protein. We tested these approaches in a laboratory scale in order to pioneer the commercial production of this protein in Escherichia coli (E. coli. Among the various strategies, which were tested under Research and Development (R&D conditions, aggregation-prone IL6 was solubilized most effectively by co-expressing cytoplasmic chaperones. Expression of a Glutathion-S-Transferase (GST fusion protein was not efficient to increase IL6 solubility. Alteration of the cultivation temperature significantly increased the solubility in both cases, whereas reduced concentrations of IPTG to induce expression of the T7lac-promotor only had a positive effect on chaperone-assisted expression. The biological activity was comparable to that of commercial IL6. Targeting the expressed protein to an oxidizing environment was not effective in the generation of soluble IL6. Taken together, the presence of chaperones and a lowered cultivation temperature seem effective to isolate large quantities of soluble IL6. This approach led to in vivo soluble, functional protein fractions and reduces purification and refolding requirements caused by downstream purification procedures. The final yield of soluble recombinant protein averaged approximately 2.6 mg IL6/liter of cell culture. These findings might be beneficial for the development of the large-scale production of IL6 under the conditions of current good manufacturing practice (cGMP.

  4. Human Monoclonal antibodies - A dual advantaged weapon to tackle cancer and viruses

    Directory of Open Access Journals (Sweden)

    Kurosawa G

    2014-11-01

    Full Text Available Human monoclonal antibodies (mAbs are powerful tools as pharmaceutical agents to tackle cancer and infectious diseases. Antibodies (Abs are present in blood at the concentration of 10 mg/ml and play a vital role in humoral immunity. Many therapeutic Abs have been reported since early 1980s. Human mAb technology was not available at that time and only the hybridoma technology for making mouse mAbs had been well established. In order to avoid various potential problems associated with use of mouse proteins, two different technologies to make human/mouse chimeric Ab as well as humanized Ab were developed crossing the various hurdles for almost twenty years and mAb based drugs such as rituximab, anti-CD20 Ab, and trastuzumab, anti-HER2 Ab, have been approved by the US Food and Drug Administration (FDA for treatment of non-Hodgkin's lymphoma and breast cancer in 1997 and 1998, respectively. These drugs are well recognized and accepted by clinicians for treatment of patients. The clinical outcome of the treatment with mAb has strongly encouraged the researchers to develop much more refined mAbs. In addition to chimeric Ab and humanized Ab, now human mAbs can be produced by two technologies. The first is transgenic mice that produce human Abs and the second is human Ab libraries using phage-display system. Until now, several hundreds of mAbs against several tens of antigens (Ags have been developed and subjected to clinical examinations. While many Abs have been approved as therapeutic agents against hematological malignancies, the successful mAbs against solid tumors are still limited. However, many researchers have suggested that developing potential mAbs agents should be possible and incurable cancers may become curable within another decade. Though it is hard to say explicitly that this prediction is correct, a passion for this development should be worth supporting to lead to a successful outcome which will lead to patient benefits. Our institute

  5. Biological function analysis of monoclonal antibodies against human granulins in vitro using U251 cells as a model.

    Science.gov (United States)

    Li, Yanqing; Li, Ya; Ye, Mingfu; Wang, Dongyang; Zhao, Junli; Sun, Xiaohong; Mao, Qinwen; Xia, Haibin

    2017-02-01

    Progranulin (PGRN), a highly glycosylated, secreted 593 amino acid precursor protein, is a multifunctional molecule that is critical for early embryogenesis, wound repair, inflammatory and tumorigenesis. PGRN can be proteolytically cleaved into seven cysteine-rich granulin (Grn) peptides: G, F, B, A, C, D and E. Both PGRN and its constituent Grn peptides have been implicated in a wide variety of biological activities. However, their functions are far from clear, and the lack of granulin domain-specific antibodies has hindered the progress of the functional study of PGRN and Grns. Monoclonal antibodies against GrnB, GrnA, GrnC and GrnF have been previously developed by our laboratory. In this study, we generated monoclonal antibodies (MAbs) against GrnD, GrnG and GrnE by using recombinant proteins HSA-GrnG, HSA-GrnD and HSA-GrnE as immunogens, and characterized them by indirect ELISA, Western blot and immunocytochemistry. Furthermore, the neutralizing activities of the MAbs against seven Grns were tested in vitro using the U251 cell line. This full antibody panel of MAbs against seven Grns will be a valuable tool for elucidating the biological roles of PGRN and Grns in different physiopathological processes, which will further promote the development of PGRN-based clinical diagnosis and therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Detection of Signal Regulatory Protein α in Saimiri sciureus (Squirrel Monkey) by Anti-Human Monoclonal Antibody

    Science.gov (United States)

    de Souza, Hugo Amorim dos Santos; Costa-Correa, Edmar Henrique; Bianco-Junior, Cesare; Andrade, Márcia Cristina Ribeiro; Lima-Junior, Josué da Costa; Pratt-Riccio, Lilian Rose; Daniel-Ribeiro, Cláudio Tadeu; Totino, Paulo Renato Rivas

    2017-01-01

    Non-human primates (NHP) are suitable models for studying different aspects of the human system, including pathogenesis and protective immunity to many diseases. However, the lack of specific immunological reagents for neo-tropical monkeys, such as Saimiri sciureus, is still a major factor limiting studies in these models. An alternative strategy to circumvent this obstacle has been the selection of immunological reagents directed to humans, which present cross-reactivity with NHP molecules. In this context and considering the key role of inhibitory immunoreceptors—such as the signal regulatory protein α (SIRPα)—in the regulation of immune responses, in the present study, we attempted to evaluate the ability of anti-human SIRPα monoclonal antibodies to recognize SIRPα in antigen-presenting S. sciureus peripheral blood mononuclear cells (PBMC). As shown by flow cytometry analysis, the profile of anti-SIRPα staining as well as the levels of SIRPα-positive cells in PBMC from S. sciureus were similar to those observed in human PBMC. Furthermore, using anti-SIRPα monoclonal antibody, it was possible to detect a decrease of the SIRPα levels on surface of S. sciureus cells after in vitro stimulation with lipopolysaccharides. Finally, using computed-based analysis, we observed a high degree of conservation of SIRPα across six species of primates and the presence of shared epitopes in the extracellular domain between humans and Saimiri genus that could be targeted by antibodies. In conclusion, we have identified a commercially available anti-human monoclonal antibody that is able to detect SIRPα of S. sciureus monkeys and that, therefore, can facilitate the study of the immunomodulatory role of SIRPα when S. sciureus is used as a model. PMID:29312325

  7. Detection of Signal Regulatory Protein α in Saimiri sciureus (Squirrel Monkey by Anti-Human Monoclonal Antibody

    Directory of Open Access Journals (Sweden)

    Hugo Amorim dos Santos de Souza

    2017-12-01

    Full Text Available Non-human primates (NHP are suitable models for studying different aspects of the human system, including pathogenesis and protective immunity to many diseases. However, the lack of specific immunological reagents for neo-tropical monkeys, such as Saimiri sciureus, is still a major factor limiting studies in these models. An alternative strategy to circumvent this obstacle has been the selection of immunological reagents directed to humans, which present cross-reactivity with NHP molecules. In this context and considering the key role of inhibitory immunoreceptors—such as the signal regulatory protein α (SIRPα—in the regulation of immune responses, in the present study, we attempted to evaluate the ability of anti-human SIRPα monoclonal antibodies to recognize SIRPα in antigen-presenting S. sciureus peripheral blood mononuclear cells (PBMC. As shown by flow cytometry analysis, the profile of anti-SIRPα staining as well as the levels of SIRPα-positive cells in PBMC from S. sciureus were similar to those observed in human PBMC. Furthermore, using anti-SIRPα monoclonal antibody, it was possible to detect a decrease of the SIRPα levels on surface of S. sciureus cells after in vitro stimulation with lipopolysaccharides. Finally, using computed-based analysis, we observed a high degree of conservation of SIRPα across six species of primates and the presence of shared epitopes in the extracellular domain between humans and Saimiri genus that could be targeted by antibodies. In conclusion, we have identified a commercially available anti-human monoclonal antibody that is able to detect SIRPα of S. sciureus monkeys and that, therefore, can facilitate the study of the immunomodulatory role of SIRPα when S. sciureus is used as a model.

  8. Monoclonal antibodies to the reactive centre loop (RCL) of human corticosteroid-binding globulin (CBG) can protect against proteolytic cleavage.

    Science.gov (United States)

    Lewis, John G; Elder, Peter A

    2017-07-01

    Corticosteroid-binding globulin (CBG) binds most of the cortisol in circulation and is a non-functional member of the family of serine protease inhibitors (serpins) with an exposed elastase sensitive reactive centre loop (RCL). The RCL can be cleaved by human neutrophil elastase, released from activated neutrophils, and can also be cleaved at nearby site(s) by elastase released by Pseudomonas aeruginosa, and at two further sites, also within the RCL, by bovine chymotrypsin. Cleavage of the RCL results in a conformational change accompanied by a marked decrease in affinity for cortisol and hence its release at the site of proteolysis. These cleavages are irreversible and the similar half-lives of cleaved and intact CBG could mean that there may be some advantage in slowing the rate of CBG cleavage in acute inflammation thereby increasing the proportion of intact CBG in circulation. Here we show, for the first time, that pre-incubation of tethered human CBG with two monoclonal antibodies to the RCL of CBG protects against cleavage by all three enzymes. Furthermore, in plasma, pre-incubation with both RCL monoclonal antibodies delays neutrophil elastase cleavage of the RCL and one of these RCL monoclonal antibodies also delays bovine chymotrypsin cleavage of the RCL. These findings may provide a basis and rationale for the concept of the use of RCL antibodies as therapeutic agents to effectively increase the proportion of intact CBG in circulation which may be of benefit in acute inflammation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Generation and characterization of ixekizumab, a humanized monoclonal antibody that neutralizes interleukin-17A

    Directory of Open Access Journals (Sweden)

    Liu L

    2016-04-01

    Full Text Available Ling Liu,1 Jirong Lu,1 Barrett W Allan,2 Ying Tang,2 Jonathan Tetreault,1 Chi-kin Chow,1 Barbra Barmettler,2 James Nelson,2 Holly Bina,1 Lihua Huang,3 Victor J Wroblewski,4 Kristine Kikly1 1Biotechnology Discovery Research, Indianapolis, IN, 2Applied Molecular Evolution, Lilly Biotechnology Center, San Diego, CA, 3Bioproduct Research and Development, 4Drug Disposition, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA Abstract: Interleukin (IL-17A exists as a homodimer (A/A or as a heterodimer (A/F with IL-17F. IL-17A is expressed by a subset of T-cells, called Th17 cells, at inflammatory sites. Most cell types can respond to the local production of IL-17A because of the near ubiquitous expression of IL-17A receptors, IL-17RA and IL-17RC. IL-17A stimulates the release of cytokines and chemokines designed to recruit and activate both neutrophils and memory T-cells to the site of injury or inflammation and maintain a proinflammatory state. IL-17A-producing pathogenic T-cells contribute to the pathogenesis of autoimmune diseases, including psoriasis, psoriatic arthritis, rheumatoid arthritis, and ankylosing spondylitis. This study describes the generation and characterization of ixekizumab, a humanized IgG4 variant IL-17A-neutralizing antibody. Ixekizumab binds human and cynomolgus monkey IL-17A with high affinity and binds rabbit IL-17A weakly but does not bind to rodent IL-17A or other IL-17 family members. Ixekizumab effectively inhibits the interaction between IL-17A and its receptor in binding assays and potently blocks IL-17A-induced GRO or KC secretion in cell-based assays. In an in vivo mouse pharmcodynamic model, ixekizumab blocks human IL-17A-induced mouse KC secretion. These data provide a comprehensive preclinical characterization of ixekizumab, for which the efficacy and safety have been demonstrated in human clinical trials in psoriasis and psoriatic arthritis.Keywords: ixekizumab, IL-17A monoclonal antibody

  10. Characterization of Entamoeba histolytica Intermediate Subunit Lectin-Specific Human Monoclonal Antibodies Generated in Transgenic Mice Expressing Human Immunoglobulin Loci ▿

    Science.gov (United States)

    Tachibana, Hiroshi; Cheng, Xun-Jia; Tsukamoto, Hideo; Itoh, Johbu

    2009-01-01

    Four fully human monoclonal antibodies (MAbs) to Entamoeba histolytica intermediate subunit lectin (Igl) were prepared in XenoMouse mice, which are transgenic mice expressing human immunoglobulin loci. Examination of the reactivities of these MAbs to recombinant Igl1 and Igl2 of E. histolytica showed that XEhI-20 {immunoglobulin G2(κ) [IgG2(κ)]} and XEhI-28 [IgG2(κ)] were specific to Igl1, XEhI-B5 [IgG2(κ)] was specific to Igl2, and XEhI-H2 [IgM(κ)] was reactive with both Igls. Gene analyses revealed that the VH and VL germ lines were VH3-48 and L2 for XEhI-20, VH3-21 and L2 for XEhI-28, VH3-33 and B3 for XEhI-B5, and VH4-4 and A19 for XEhI-H2, respectively. Flow cytometry analyses showed that the epitopes recognized by all of these MAbs were located on the surfaces of living trophozoites. Confocal microscopy demonstrated that most Igl1 and Igl2 proteins were colocalized on the surface and in the cytoplasm, but different localization patterns in intracellular vacuoles were also present. The preincubation of trophozoites with XEhI-20, XEhI-B5, and XEhI-H2 caused significant inhibition of the adherence of trophozoites to Chinese hamster ovary cells, whereas preincubation with XEhI-28 did not do so. XEhI-20, XEhI-B5, and XEhI-H2 were injected intraperitoneally into hamsters 24 h prior to intrahepatic challenge with E. histolytica trophozoites. One week later, the mean abscess size in groups injected with one of the three MAbs was significantly smaller than that in controls injected with polyclonal IgG or IgM isolated from healthy humans. These results demonstrate that human MAbs to Igls may be applicable for immunoprophylaxis of amebiasis. PMID:19001071

  11. Affinity maturation to improve human monoclonal antibody neutralization potency and breadth against hepatitis C virus.

    Science.gov (United States)

    Wang, Yong; Keck, Zhen-yong; Saha, Anasuya; Xia, Jinming; Conrad, Fraser; Lou, Jianlong; Eckart, Michael; Marks, James D; Foung, Steven K H

    2011-12-23

    A potent neutralizing antibody to a conserved hepatitis C virus (HCV) epitope might overcome its extreme variability, allowing immunotherapy. The human monoclonal antibody HC-1 recognizes a conformational epitope on the HCV E2 glycoprotein. Previous studies showed that HC-1 neutralizes most HCV genotypes but has modest potency. To improve neutralization, we affinity-matured HC-1 by constructing a library of yeast-displayed HC-1 single chain Fv (scFv) mutants, using for selection an E2 antigen from one of the poorly neutralized HCVpp. We developed an approach by parallel mutagenesis of the heavy chain variable (VH) and κ-chain variable (Vk) genes separately, then combining the optimized VH and Vk mutants. This resulted in the generation of HC-1-related scFv variants exhibiting improved affinities. The best scFv variant had a 92-fold improved affinity. After conversion to IgG1, some of the antibodies exhibited a 30-fold improvement in neutralization activity. Both surface plasmon resonance and solution kinetic exclusion analysis showed that the increase in affinity was largely due to a lowering of the dissociation rate constant, Koff. Neutralization against a panel of HCV pseudoparticles and infectious 2a HCV virus improved with the affinity-matured IgG1 antibodies. Interestingly, some of these antibodies neutralized a viral isolate that was not neutralized by wild-type HC-1. Moreover, propagating 2a HCVcc under the selective pressure of WT HC-1 or affinity-matured HC-1 antibodies yielded no viral escape mutants and, with the affinity-matured IgG1, needed 100-fold less antibody to achieve complete virus elimination. Taken together, these findings suggest that affinity-matured HC-1 antibodies are excellent candidates for therapeutic development.

  12. Microcalorimetric study of adsorption of human monoclonal antibodies on cation exchange chromatographic materials.

    Science.gov (United States)

    Dieterle, Michael; Blaschke, Tim; Hasse, Hans

    2008-09-26

    Adsorption of two human monoclonal antibodies on two different strong cation exchange resins is studied by isothermal titration microcalorimetry and independent adsorption isotherm measurements. The pH value is varied between 4.5 and 7.0, using different buffer systems, the temperature is always 25 degrees C. The adsorption isotherm data is fitted using two different Langmuir type models. Combining the calorimetric and the adsorption data, the specific enthalpy of adsorption of the protein Deltah(p)(ads) is determined. At pH values near 7.0, where the antibodies are only weakly charged, the adsorption is exothermal. At small loadings the absolute number of Deltah(p)(ads) is then large and almost constant but it significantly decreases at higher loadings. This shows that the arrangement of antibody molecules on the absorber material depends on the loading and is less favourable at higher loadings. Despite the high positive charge of the antibody at pH values of about 5 the value of Deltah(p)(ads) is almost zero along the entire isotherm. Furthermore, at pH 4.5 even endothermal effects are observed, although high binding capacities are found. At these conditions the adsorption process seems to be strongly influenced by the ions bound to the antibody. Their release upon absorption explains the endothermal caloric effect. The adsorption equilibrium constant K(eq) is calculated from the isotherms. From Deltag(p)(ads) and the calorimetric results for Deltah(p)(ads), Deltas(p)(ads), the entropy change upon adsorption of the protein is found for the different studied conditions.

  13. Production of recombinant scFv against p24 of human immunodeficiency virus type 1 by phage display technology.

    Science.gov (United States)

    Mohammadzadeh, Sara; Rajabibazl, Masoumeh; Fourozandeh, Mehdi; Rasaee, Mohammad Javad; Rahbarizadeh, Fatemeh; Mohammadi, Mohammad

    2014-02-01

    Phage display has a fundamental role in protein isolation and engineering. Isolated proteins produced with this method can be modified for specific binding and affinity. P24 is the most produced protein during human immune deficiency virus (HIV) replication; especially in the early steps of HIV-1 infection, its evaluation may have diagnostic values. To test the HIV-1 infection, p24 antigen assay appears to be a very promising alternative to RNA assays. In this study, we have generated a recombinant mouse single chain antibody fragment against p24 of the HIV-1 with the use of phage display technology. After isolation of antibody variable-region (V) gene of B cells extracted from the spleen of an immunized mouse, a library of single chain Fv fragments (scFv) was constructed. The library was used in a series of bio-panning processes against recombinant p24 protein expressed from Escherichia coli. The isolated scFv antibody specifically recognizes the HIV-1 capsid protein p24. The affinity constant of the isolated scFv antibody (MF85) was found to be 2×10(-9) M. Our studies showed that the MF85 scFV antibody has similar properties as that of monoclonal antibodies produced by the hybridoma technology.

  14. 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

    Full Text Available Background: Human plasminogen is a plasma glycoprotein synthesized mainly in the liver. Conversion of plasminogen to plasmin by plasminogen activators is a key event in the fibrinolytic system. In this study, we investigated the effects of two anti-human plasminogen monoclonal antibodies, A1D12 and MC2B8 on Glu-plasminogen activation in presence of u-PA, t-PA and streptokinase. Methods: Producing of Hybridoma antibodies was performed by fusion of spleen cells from BALB/C mice immunized with Glu-plasminogen and NS1 myeloma cells. Antibody binding to Human Glu-plasminogen was assessed using an ELISA assay. Activation of plasminogen was determined by measuring plasmin generation using the chromogenic substrate S-2251 and the effect of monoclonal antibodies, A1D12 and MC2B8 on plasminogen activation in solution was then evaluated. Initial rates and kinetic parameters of plasminogen activation in the presence of monoclonal antibodies were calculated. The effect of the monoclonal antibody MC2B8 on the rate of plasmin hydrolysis was measured. The effect of F(ab'2 fragment of A1D12 on u-PA catalyzed-plasminogen activation also compared with the effect of the whole antibody in this reaction. Results: ELISA assay showed that the antibodies reacted well with antigens. A1D12 increased the maximum velocity (Vmax of plasminogen activation by each of the three plasminogen activators and MC2B8 decreased it. In all activation reactions, the KM value of plasminogen activation did not significantly change in the presence of antibody A1D12 whereas antibody MC2B8 increased the KM value of plasminogen activation by u-PA, fibrin monomer dependent t-PA and streptokinase. Monoclonal antibody MC2B8 had no significant effect on plasmin hydrolysis rate of synthetic substrate S-2251. Activation rate of plasminogen by u-PA in the lower concentration of F (ab2 fragment of A1D12 was identical to activation in the presence of the whole antibody. Conclusion: The binding of

  15. Similarity in recombination rate estimates highly correlates with genetic differentiation in humans.

    Directory of Open Access Journals (Sweden)

    Hafid Laayouni

    Full Text Available Recombination varies greatly among species, as illustrated by the poor conservation of the recombination landscape between humans and chimpanzees. Thus, shorter evolutionary time frames are needed to understand the evolution of recombination. Here, we analyze its recent evolution in humans. We calculated the recombination rates between adjacent pairs of 636,933 common single-nucleotide polymorphism loci in 28 worldwide human populations and analyzed them in relation to genetic distances between populations. We found a strong and highly significant correlation between similarity in the recombination rates corrected for effective population size and genetic differentiation between populations. This correlation is observed at the genome-wide level, but also for each chromosome and when genetic distances and recombination similarities are calculated independently from different parts of the genome. Moreover, and more relevant, this relationship is robustly maintained when considering presence/absence of recombination hotspots. Simulations show that this correlation cannot be explained by biases in the inference of recombination rates caused by haplotype sharing among similar populations. This result indicates a rapid pace of evolution of recombination, within the time span of differentiation of modern humans.

  16. Epitope Mapping of Neutralizing Monoclonal Antibodies to Human Interferon-γ Using Human-Bovine Interferon-γ Chimeras

    Science.gov (United States)

    Zuber, Bartek; Rudström, Karin; Ehrnfelt, Cecilia

    2016-01-01

    Our aim was to identify conformational epitopes, recognized by monoclonal antibodies (mAbs) made against human (h) interferon (IFN)-γ. Based on the mAbs' (n = 12) ability to simultaneously bind hIFN-γ in ELISA, 2 epitope clusters with 5 mAbs in each were defined; 2 mAbs recognized unique epitopes. Utilizing the mAbs' lack of reactivity with bovine (b) IFN-γ, epitopes were identified using 7 h/bIFN-γ chimeras where the helical regions (A-F) or the C terminus were substituted with bIFN-γ residues. Chimeras had a N-terminal peptide tag enabling the analysis of mAb recognition of chimeras in ELISA. The 2 mAb clusters mapped to region A and E, respectively; the epitopes of several mAbs also involved additional regions. MAbs in cluster A neutralized, to various degrees, IFN-γ-mediated activation of human cells, in line with the involvement of region A in the IFN-γ receptor interaction. MAbs mapping to region E displayed a stronger neutralizing capacity although this region has not been directly implicated in the receptor interaction. The results corroborate earlier studies and provide a detailed picture of the link between the epitope specificity and neutralizing capacity of mAbs. They further demonstrate the general use of peptide-tagged chimeric proteins as a powerful and straightforward method for efficient mapping of conformational epitopes. PMID:27336613

  17. Monoclonal antibodies reveal multiple forms of expression of human microsomal epoxide hydrolase

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Hongying; Takagi, Akira [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Kayano, Hidekazu [Department of Pathology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Koyama, Isamu [Department of Digestive and General Surgery, Saitama International Medical Center, Faculty of Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan); Morisseau, Christophe; Hammock, Bruce D. [Department of Entomology and Cancer Center, University of California, Davis, One Shields Avenue, Davis, CA 95616-8584 (United States); Akatsuka, Toshitaka, E-mail: akatsuka@saitama-med.ac.jp [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan)

    2012-04-01

    In a previous study, we developed five kinds of monoclonal antibodies against different portions of human mEH: three, anti-N-terminal; one, anti-C-terminal; one, anti-conformational epitope. Using them, we stained the intact and the permeabilized human cells of various kinds and performed flow cytometric analysis. Primary hepatocytes and peripheral blood mononuclear cells (PBMC) showed remarkable differences. On the surface, hepatocytes exhibited 4 out of 5 epitopes whereas PBMC did not show any of the epitopes. mEH was detected inside both cell types, but the most prominent expression was observed for the conformational epitope in the hepatocytes and the two N-terminal epitopes in PBMC. These differences were also observed between hepatocyte-derived cell lines and mononuclear cell-derived cell lines. In addition, among each group, there were several differences which may be related to the cultivation, the degree of differentiation, or the original cell subsets. We also noted that two glioblastoma cell lines reveal marked expression of the conformational epitope on the surface which seemed to correlate with the brain tumor-associated antigen reported elsewhere. Several cell lines also underwent selective permeabilization before flow cytometric analysis, and we noticed that the topological orientation of mEH on the ER membrane in those cells was in accordance with the previous report. However, the orientation on the cell surface was inconsistent with the report and had a great variation between the cells. These findings show the multiple mode of expression of mEH which may be possibly related to the multiple roles that mEH plays in different cells. -- Highlights: ► We examine expression of five mEH epitopes in human cells. ► Remarkable differences exist between hepatocytes and PBMC. ► mEH expression in cell lines differs depending on several factors. ► Some glioblastoma cell lines reveal marked surface expression of mEH. ► Topology of mEH on the cell

  18. Monoclonal antibody "gold rush".

    Science.gov (United States)

    Maggon, Krishan

    2007-01-01

    The market, sales and regulatory approval of new human medicines, during the past few years, indicates increasing number and share of new biologics and emergence of new multibillion dollar molecules. The global sale of monoclonal antibodies in 2006 were $20.6 billion. Remicade had annual sales gain of $1 billion during the past 3 years and five brands had similar increase in 2006. Rituxan with 2006 sales of $4.7 billion was the best selling monoclonal antibody and biological product and the 6th among the top selling medicinal brand. It may be the first biologic and monoclonal antibody to reach $10 billion annual sales in the near future. The strong demand from cancer and arthritis patients has surpassed almost all commercial market research reports and sales forecast. Seven monoclonal antibody brands in 2006 had sales exceeding $1 billion. Humanized or fully human monoclonal antibodies with low immunogenicity, enhanced antigen binding and reduced cellular toxicity provide better clinical efficacy. The higher technical and clinical success rate, overcoming of technical hurdles in large scale manufacturing, low cost of market entry and IND filing, use of fully human and humanized monoclonal antibodies has attracted funds and resources towards R&D. Review of industry research pipeline and sales data during the past 3 years indicate a real paradigm shift in industrial R&D from pharmaceutical to biologics and monoclonal antibodies. The antibody bandwagon has been joined by 200 companies with hundreds of new projects and targets and has attracted billions of dollars in R&D investment, acquisitions and licensing deals leading to the current Monoclonal Antibody Gold Rush.

  19. Monoclonal antibodies against a synthetic peptide from human immunodeficiency virus type 1 Nef protein

    DEFF Research Database (Denmark)

    Steinaa, L; Wulff, A M; Saermark, T

    1994-01-01

    Monoclonal antibodies against a synthetic peptide (aa 138-152) from HIV-1 Nef protein were produced and characterized. Three hybridoma lines producing monoclonal antibodies (MAbs) against the synthetic peptide were generated by fusion between P3-X63 Ag8.653 myeloma cells and BALB/c splenocytes from...... mice immunized with the synthetic peptide coupled to keyhole limpet hemocyanin (KLH). The hybridomas were screened and selected by ELISA with the peptide coupled to bovine serum albumin (BSA) immobilized to the polystyrene surface and specificity for the peptide was confirmed by competitive ELISA...

  20. Molecular profile of a human monoclonal antibody Fab fragment specific for Epstein-Barr virus gp350/220 antigen.

    Science.gov (United States)

    Bugli, F; Bastidas, R; Burton, D R; Williamson, R A; Clementi, M; Burioni, R

    2001-04-01

    Experimental evidence indicates Epstein Barr virus (EBV) envelope glycoprotein gp350/220 elicits a potent virus neutralizing response in the infected human host that may play an important role in restricting viral pathogenesis. In this study, we report the molecular cloning in combinatorial phage display vectors, of the IgG1 repertoire of an individual naturally infected with EBV, and describe the recovery and characterization of a monoclonal antibody recognizing gp350/220. A detailed understanding of the human antibody response in EBV infection will identify antibodies of potential use in anti-viral prophylaxis and will advance the production of more effective vaccine candidates.

  1. Accelerators of Osteogenesis by Recombinant Human Bone Morphogenetic Protein-2

    Directory of Open Access Journals (Sweden)

    Yasunori Okubo

    2007-01-01

    Full Text Available Bone morphogenetic protein (BMP appears to be one of the most promising cytokine and for clinical use in reconstructive surgery for bony defects and augmentation. To evaluate the effect of basic fibroblast growth factor (bFGF, FK506, elcatonin, and hyperbaric oxygenation (HBO on osteoinduction by recombinant human bone morphogenetic protein-2 (rhBMP-2, 2 or 5 μg of rhBMP-2 was implanted into intramuscular sites of rats. At 21 days after implantation, the osteoinductive activity in the treatment group and control group was compared radiographically, biochemically, and histologically. The amount of new bone in the treatment group was significantly greater than that in the control group. The alkaline phosphatase activity and calcium content in the treatment group were significantly higher than those in the control group. These results suggest that bFGF, FK506, elcatonin, and HBO accelerated the activity and rate of osteoinduction by rhBMP2. These results may be useful when BMP is applied clinically in near future.

  2. Accelerators of Osteogenesis by Recombinant Human Bone Morphogenetic Protein-2

    Directory of Open Access Journals (Sweden)

    Yasunori Okubo

    2007-01-01

    Full Text Available Bone morphogenetic protein (BMP appears to be one of the most promising cytokine and for clinical use in reconstructive surgery for bony defects and augmentation. To evaluate the effect of basic fibroblast growth factor (bFGF, FK506, elcatonin, and hyperbaric oxygenation (HBO on osteoinduction by recombinant human bone morphogenetic protein-2 (rhBMP-2, 2 or 5 μg of rhBMP-2 was implanted into intramuscular sites of rats. At 21 days after implantation, the osteoinductive activity in the treatment group and control group was compared radiographically, biochemically, and histologically. The amount of new bone in the treatment group was signifi cantly greater than that in the control group. The alkaline phosphatase activity and calcium content in the treatment group were signifi cantly higher than those in the control group. These results suggest that bFGF, FK506, elcatonin, and HBO accelerated the activity and rate of osteoinduction by rhBMP2. These results may be useful when BMP is applied clinically in near future.

  3. Effects of Recombinant Human Prolactin on Breast Milk Composition

    Science.gov (United States)

    Powe, Camille E.; Puopolo, Karen M.; Newburg, David S.; Lönnerdal, Bo; Chen, Ceng; Allen, Maureen; Merewood, Anne; Worden, Susan

    2011-01-01

    OBJECTIVE: The objective of this study was to determine the impact of recombinant human prolactin (r-hPRL) on the nutritional and immunologic composition of breast milk. METHODS: We conducted 2 trials of r-hPRL treatment. In the first study, mothers with documented prolactin deficiency were given r-hPRL every 12 hours in a 28-day, open-label trial. In the second study, mothers with lactation insufficiency that developed while they were pumping breast milk for their preterm infants were given r-hPRL daily in a 7-day, double-blind, placebo-controlled trial. Breast milk characteristics were compared before and during 7 days of treatment. RESULTS: Among subjects treated with r-hPRL (N = 11), milk volumes (73 ± 36 to 146 ± 54 mL/day; P lactogenesis. r-hPRL also increased antimicrobially active oligosaccharide concentrations. These effects were achieved for women with both prolactin deficiency and lactation insufficiency. PMID:21262884

  4. Genetic heterogeneity and recombination in type-3 human astroviruses.

    Science.gov (United States)

    Medici, Maria Cristina; Tummolo, Fabio; Martella, Vito; Banyai, Krisztián; Bonerba, Elisabetta; Chezzi, Carlo; Arcangeletti, Maria Cristina; De Conto, Flora; Calderaro, Adriana

    2015-06-01

    Human astroviruses (HAstVs) are important enteric pathogens and can be classified genetically and antigenically into eight types. During molecular surveillance for HAstVs in Italy, sequence analysis of the diagnostic region C (about 400 nucleotide in length), located on the capsid (ORF2) gene, identified a novel type-3 strain. Upon sequencing of the full-length ORF2, the type-3 HAstV strain was characterized as a novel ORF2 genetic lineage, designated as 3c. By converse, in the ORF1b the virus was more similar to type-1 HAstVs, rather than to type-3 strains, suggesting a recombination nature, with the crossover site being mapped to the ORF1b/ORF2 junction region. Region C sequences of similar type-3 HAstV identified from European and extra-European countries were retrieved in the databases, suggesting the global distribution of this novel type-3 lineage. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Purification and characterization of human recombinant interleukin-1 beta.

    Science.gov (United States)

    Meyers, C A; Johanson, K O; Miles, L M; McDevitt, P J; Simon, P L; Webb, R L; Chen, M J; Holskin, B P; Lillquist, J S; Young, P R

    1987-08-15

    A human interleukin-1 (IL-1) beta cDNA was cloned, and the region coding for the mature protein was expressed in Escherichia coli. The 17-kDa biologically active product was purified in 40% yield to apparent homogeneity, without chaotropes, from the soluble fraction of sonicated cell lysates. The recombinant IL-1 beta was characterized by amino acid analysis, NH2- and COOH-terminal sequence analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, spectroscopy, and biological assay. Specific biological activity was 4.6 X 10(8) units/mg in a co-mitogenic IL-2 induction assay using cultured EL-4 T-lymphocytes. The molar extinction coefficient was determined to be 10,300 cm-1 M-1 at 280 nm. NH2-terminal sequence analysis revealed that 70% of the product begins with the Ala corresponding to the NH2 terminus of the natural protein, while 30% begins with the following Pro. No initiator Met was observed. Both of the sulfhydryl groups are reactive to Ellman's reagent and to iodoacetamide under nonreducing conditions, indicating that the Cys residues do not form disulfide bonds. S-Carboxamidomethyl-Cys-rIL-1 beta retained biological activity in the IL-2 induction assay. Circular dichroism suggested an extensive beta sheet structure for rIL-1 beta.

  6. Recombinant Human Factor IX Produced from Transgenic Porcine Milk

    Directory of Open Access Journals (Sweden)

    Meng-Hwan Lee

    2014-01-01

    Full Text Available Production of biopharmaceuticals from transgenic animal milk is a cost-effective method for highly complex proteins that cannot be efficiently produced using conventional systems such as microorganisms or animal cells. Yields of recombinant human factor IX (rhFIX produced from transgenic porcine milk under the control of the bovine α-lactalbumin promoter reached 0.25 mg/mL. The rhFIX protein was purified from transgenic porcine milk using a three-column purification scheme after a precipitation step to remove casein. The purified protein had high specific activity and a low ratio of the active form (FIXa. The purified rhFIX had 11.9 γ-carboxyglutamic acid (Gla residues/mol protein, which approached full occupancy of the 12 potential sites in the Gla domain. The rhFIX was shown to have a higher isoelectric point and lower sialic acid content than plasma-derived FIX (pdFIX. The rhFIX had the same N-glycosylation sites and phosphorylation sites as pdFIX, but had a higher specific activity. These results suggest that rhFIX produced from porcine milk is physiologically active and they support the use of transgenic animals as bioreactors for industrial scale production in milk.

  7. A systematic analysis of recombination activity and genotype-phenotype correlation in human recombination-activating gene 1 deficiency.

    Science.gov (United States)

    Lee, Yu Nee; Frugoni, Francesco; Dobbs, Kerry; Walter, Jolan E; Giliani, Silvia; Gennery, Andrew R; Al-Herz, Waleed; Haddad, Elie; LeDeist, Francoise; Bleesing, Jack H; Henderson, Lauren A; Pai, Sung-Yun; Nelson, Robert P; El-Ghoneimy, Dalia H; El-Feky, Reem A; Reda, Shereen M; Hossny, Elham; Soler-Palacin, Pere; Fuleihan, Ramsay L; Patel, Niraj C; Massaad, Michel J; Geha, Raif S; Puck, Jennifer M; Palma, Paolo; Cancrini, Caterina; Chen, Karin; Vihinen, Mauno; Alt, Frederick W; Notarangelo, Luigi D

    2014-04-01

    The recombination-activating gene (RAG) 1/2 proteins play a critical role in the development of T and B cells by initiating the VDJ recombination process that leads to generation of a broad T-cell receptor (TCR) and B-cell receptor repertoire. Pathogenic mutations in the RAG1/2 genes result in various forms of primary immunodeficiency, ranging from T(-)B(-) severe combined immune deficiency to delayed-onset disease with granuloma formation, autoimmunity, or both. It is not clear what contributes to such heterogeneity of phenotypes. We sought to investigate the molecular basis for phenotypic diversity presented in patients with various RAG1 mutations. We have developed a flow cytometry-based assay that allows analysis of RAG recombination activity based on green fluorescent protein expression and have assessed the induction of the Ighc locus rearrangements in mouse Rag1(-/-) pro-B cells reconstituted with wild-type or mutant human RAG1 (hRAG1) using deep sequencing technology. Here we demonstrate correlation between defective recombination activity of hRAG1 mutant proteins and severity of the clinical and immunologic phenotype and provide insights on the molecular mechanisms accounting for such phenotypic diversity. Using a sensitive assay to measure the RAG1 activity level of 79 mutations in a physiologic setting, we demonstrate correlation between recombination activity of RAG1 mutants and the severity of clinical presentation and show that RAG1 mutants can induce specific abnormalities of the VDJ recombination process. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  8. Preclinical characterization of an anti-methamphetamine monoclonal antibody for human use.

    Science.gov (United States)

    Stevens, Misty W; Tawney, Rachel L; West, C Michael; Kight, Alicia D; Henry, Ralph L; Owens, S Michael; Gentry, W Brooks

    2014-01-01

    Ch-mAb7F9, a human-mouse chimeric monoclonal antibody (mAb) designed to bind (+)-methamphetamine (METH) with high affinity and specificity, was produced as a treatment medication for METH abuse. In these studies, we present the preclinical characterization that provided predictive evidence that ch-mAb7F9 may be safe and effective in humans. In vitro ligand binding studies showed that ch-mAb7F9 is specific for and only binds its target ligands (METH, (+)-amphetamine, and 3,4-methylenedioxy-N-methylamphetamine) with high affinity. It did not bind endogenous neurotransmitters or other medications and was not bound by protein C1q, thus it is unlikely to stimulate in vivo complement-dependent cytotoxicity. Isothermal titration calorimetry potency studies showed that METH binding by ch-mAb7F9 is efficient. Pharmacokinetic studies of METH given after ch-mAb7F9 doses in rats demonstrated the in vivo application of these in vitro METH-binding characteristics. While METH had little effect on ch-mAb7F9 disposition, ch-mAb7F9 substantially altered METH disposition, dramatically reducing the volume of distribution and clearance of METH. The elimination half-life of METH was increased by ch-mAb7F9, but it was still very fast compared with the elimination of ch-mAb7F9. Importantly, the rapid elimination of unbound METH combined with previous knowledge of mAb:target ligand binding dynamics suggested that ch-mAb7F9 binding capacity regenerates over time. This finding has substantial therapeutic implications regarding the METH doses against which ch-mAb7F9 will be effective, on the duration of ch-mAb7F9 effects, and on the safety of ch-mAb7F9 in METH users who use METH while taking ch-mAb7F9. These results helped to support initiation of a Phase 1a study of ch-mAb7F9.

  9. Seroepidemiology of Human Papillomavirus 16 (HPV16) L2 and Generation of L2-Specific Human Chimeric Monoclonal Antibodies.

    Science.gov (United States)

    Wang, Joshua W; Jagu, Subhashini; Wu, Wai-Hong; Viscidi, Raphael P; Macgregor-Das, Anne; Fogel, Jessica M; Kwak, Kihyuck; Daayana, Sai; Kitchener, Henry; Stern, Peter L; Gravitt, Patti E; Trimble, Cornelia L; Roden, Richard B S

    2015-07-01

    Presently, the seroprevalence of human papillomavirus (HPV) minor capsid antigen L2-reactive antibody is not well understood, and no serologic standard exists for L2-specific neutralizing antibodies. Therefore, we screened a total of 1,078 serum samples for HPV16 L2 reactivity, and these were obtained from four prior clinical studies: a population-based (n = 880) surveillance study with a high-risk HPV DNA prevalence of 10.8%, a cohort study of women (n = 160) with high-grade cervical intraepithelial neoplasia (CIN), and two phase II trials in women with high-grade vulvar intraepithelial neoplasia (VIN) receiving imiquimod therapy combined with either photodynamic therapy (PDT) (n = 19) or vaccination with a fusion protein comprising HPV16 L2, E7, and E6 (TA-CIN) (n = 19). Sera were screened sequentially by HPV16 L2 enzyme-linked immunosorbent assay (ELISA) and then Western blot. Seven of the 1,078 serum samples tested had L2-specific antibodies, but none were detectably neutralizing for HPV16. To develop a standard, we substituted human IgG1 sequences into conserved regions of two rodent monoclonal antibodies (MAbs) specific for neutralizing epitopes at HPV16 L2 residues 17 to 36 and 58 to 64, creating JWW-1 and JWW-2, respectively. These chimeric MAbs retained neutralizing activity and together reacted with 33/34 clinically relevant HPV types tested. In conclusion, our inability to identify an HPV16 L2-specific neutralizing antibody response even in the sera of patients with active genital HPV disease suggests the subdominance of L2 protective epitopes and the value of the chimeric MAbs JWW-1 and JWW-2 as standards for immunoassays to measure L2-specific human antibodies. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Rational methods for predicting human monoclonal antibodies retention in protein A affinity chromatography and cation exchange chromatography. Structure-based chromatography design for monoclonal antibodies.

    Science.gov (United States)

    Ishihara, Takashi; Kadoya, Toshihiko; Yoshida, Hideaki; Tamada, Taro; Yamamoto, Shuichi

    2005-11-04

    Rational methods for predicting the chromatographic behavior of human monoclonal antibodies (hMabs) in protein A affinity chromatography and cation exchange chromatography from the amino acid sequences information were proposed. We investigated the relation between the structures of 28 hMabs and their chromatographic behavior in protein A affinity chromatography and cation exchange chromatography using linear gradient elution experiments. In protein A affinity chromatography, the elution pH of the hMabs was correlated with not only the structure of the Fc region (subclass), but also that of the variable region. The elution pH of hMabs that have LYLQMNSL sequences in between the CDR2 and CDR3 regions of the heavy chain became lower among the same subclass of hMabs. In cation exchange chromatography, the peak salt concentrations IR of hMabs that have the same sequences of variable regions (or that have a structural difference in their Fc region, which puts them into a subclass) were similar. The IR values of hMabs were well correlated with the equilibrium association constant Ke, and also with the surface positive charge distribution of the variable region of the heavy chain (corrected surface net positive charge (cN) of the VH region). Based on these findings, we developed rational methods for predicting the retention behavior, which were also tested with eight additional hMabs. By considering the information on the number of binding sites associated with protein adsorption as determined experimentally, and the surface positive charge distribution from the three-dimensional structure of Mab A, we hypothesized that hMabs is separated by cation exchange chromatography as the surface positive charge distribution of the VH region is recognized.

  11. Recombinant avian adeno-associated virus-mediated oviduct-specific expression of recombinant human tissue kallikrein.

    Science.gov (United States)

    Wang, A P; Sun, H C; Wang, J Y; Wang, Y J; Yuan, W F

    2008-04-01

    Human tissue kallikrein (hK1) plays an important role in regulation of blood pressure, electrolyte and glucose transport, and renal function. To evaluate the feasibility of viral vector-mediated expression of recombinant human tissue kallikrein (rhK1) in the egg white of laying hens, human tissue kallikrein gene (hKLK1) cDNA-expression cassette was subcloned into avian adeno-associated virus (AAAV) transfer vector pAITR and transfected into AAV-293 cells with AAAV helper vector pcDNA-ARC and adenovirus helper vector pHelper. The recombinant viral particles with a typical AAAV morphology and relatively high titer were generated and identified by PCR and electron microscopy. After 1 intravenous injection of each laying hen with 2 x 10(10) viral particles, oviduct-specific expression of hKLK1 cDNA was demonstrated by reverse transcription-PCR. Secretion of rhK1 into the egg white was detected by enzymatic assay from d 2, reaching the highest level of 107 U/mL in wk 3, and lasted for more than 6 wk after injection. Western blotting showed that the oviduct-expressed rhK1 had the same molecular mass with the natural enzyme. These data suggest that rAAAV can mediate high level and long-lasting transgene expression in oviduct cells, and the established expression system is useful for production of other recombinant proteins.

  12. Analysis of Monoclonal Antibodies in Human Serum as a Model for Clinical Monoclonal Gammopathy by Use of 21 Tesla FT-ICR Top-Down and Middle-Down MS/MS

    Science.gov (United States)

    He, Lidong; Anderson, Lissa C.; Barnidge, David R.; Murray, David L.; Hendrickson, Christopher L.; Marshall, Alan G.

    2017-05-01

    With the rapid growth of therapeutic monoclonal antibodies (mAbs), stringent quality control is needed to ensure clinical safety and efficacy. Monoclonal antibody primary sequence and post-translational modifications (PTM) are conventionally analyzed with labor-intensive, bottom-up tandem mass spectrometry (MS/MS), which is limited by incomplete peptide sequence coverage and introduction of artifacts during the lengthy analysis procedure. Here, we describe top-down and middle-down approaches with the advantages of fast sample preparation with minimal artifacts, ultrahigh mass accuracy, and extensive residue cleavages by use of 21 tesla FT-ICR MS/MS. The ultrahigh mass accuracy yields an RMS error of 0.2-0.4 ppm for antibody light chain, heavy chain, heavy chain Fc/2, and Fd subunits. The corresponding sequence coverages are 81%, 38%, 72%, and 65% with MS/MS RMS error 4 ppm. Extension to a monoclonal antibody in human serum as a monoclonal gammopathy model yielded 53% sequence coverage from two nano-LC MS/MS runs. A blind analysis of five therapeutic monoclonal antibodies at clinically relevant concentrations in human serum resulted in correct identification of all five antibodies. Nano-LC 21 T FT-ICR MS/MS provides nonpareil mass resolution, mass accuracy, and sequence coverage for mAbs, and sets a benchmark for MS/MS analysis of multiple mAbs in serum. This is the first time that extensive cleavages for both variable and constant regions have been achieved for mAbs in a human serum background.

  13. Integrin alphaIIbbeta3-specific synthetic human monoclonal antibodies and HCDR3 peptides that potently inhibit platelet aggregation.

    Science.gov (United States)

    Chung, Junho; Rader, Christoph; Popkov, Mikhail; Hur, Young-Mi; Kim, Hyun-Kyung; Lee, Young-Joon; Barbas, Carlos F

    2004-02-01

    The interaction of fibrinogen with integrin alphaIIbbeta3 (GPIIb/IIIa), in part mediated by an RGD tripeptide motif, is an essential step in platelet aggregation. Based on their inhibition of platelet aggregation, three integrin alphaIIbbeta3 inhibitors are clinically approved. The clinically most widely used integrin alphaIIbbeta3 inhibitor abciximab is a chimeric mouse/human antibody that induces thrombocytopenia, often severe, in 1-2% of patients due to a human anti-mouse antibody (HAMA) response. In addition, unlike other ligands mimicking small molecular drugs, abciximab cross-reacts with integrin alphavbeta3 and alphaMbeta2. Here we used phage display to select monoclonal antibodies specific to integrin alphaIIbbeta3 from a synthetic human antibody library based on the randomized HCDR3 sequence VGXXXRADXXXYAMDV. The selected antibodies revealed a strong consensus in HCDR3 (V(V/W)CRAD(K/R)RC) and high specificity toward integrin alphaIIbbeta3 but not to other RGD binding integrins such as alphavbeta3, alphavbeta5, and alpha5beta1. The selected antibodies as well as three synthetic peptides (VWCRADRRC, VWCRADKRC, and VVCRADRRC) whose sequences were derived from the HCDR3 sequences of the selected antibodies strongly inhibited the interaction between integrin alphaIIbbeta3 and fibrinogen and platelet aggregation ex vivo. To our knowledge, these are the first fully human monoclonal antibodies that are specific to integrin alphaIIbbeta3 and can potently inhibit platelet aggregation.

  14. Epratuzumab, a humanized monoclonal antibody targeting CD22: characterization of in vitro properties.

    Science.gov (United States)

    Carnahan, Josette; Wang, Paul; Kendall, Richard; Chen, Ching; Hu, Sylvia; Boone, Tom; Juan, Todd; Talvenheimo, Jane; Montestruque, Silvia; Sun, Jilin; Elliott, Gary; Thomas, John; Ferbas, John; Kern, Brent; Briddell, Robert; Leonard, John P; Cesano, Alessandra

    2003-09-01

    Epratuzumab is a novel humanized antihuman CD22 IgG1 antibody that has recently shown promising clinical activity, both as a single agent and in combination with rituximab, in patients with non-Hodgkin's lymphomas (NHL). In an attempt to better understand the mode of action of epratuzumab, the antibody was tested in vitro in a variety of cell-based assays similar to those used to evaluate the biological activity of other therapeutic monoclonal antibodies, including rituximab. In this report, we present epratuzumab activities as they relate to binding, signaling, and internalization of the receptor CD22. Chinese hamster ovary-expressed CD22 extracellular domain was used to measure epratuzumab affinity on Biacore. CD22 receptor density and internalization rate were measured indirectly using a monovalently labeled, noncompeting (with epratuzumab) anti-CD22 antibody on Burkitt lymphoma cell lines, primary B cells derived from fresh tonsils, and B cells separated from peripheral blood samples obtained from patients with chronic lymphocytic leukemia or healthy volunteers. Epratuzumab-induced CD22 phosphorylation was measured by immunoprecipitation/Western blot and compared with that induced by anti-IgM stimulation. Epratuzumab binds to CD22-extracellular domain, with an affinity of K(D) = 0.7 nM. Binding of epratuzumab to B cell lines, or primary B cells from healthy individuals and patients with NHL, results in rapid internalization of the CD22/antibody complex. Internalization appears to be faster at early time points in cell lines than in primary B cells and NHL patient-derived B cells, but the maximum internalization reached is comparable for all B cell populations after several hours of treatment and appears to reach saturation at antibody concentrations of 1-5 micro g/ml. Finally, epratuzumab binding results in modest but significant CD22 phosphorylation. Epratuzumab represents an excellent anti-CD22 ligating agent, highly efficacious in inducing CD22

  15. Adsorption behavior of a human monoclonal antibody at hydrophilic and hydrophobic surfaces.

    Science.gov (United States)

    Couston, Ruairidh G; Skoda, Maximilian W; Uddin, Shahid; van der Walle, Christopher F

    2013-01-01

    One aspiration for the formulation of human monoclonal antibodies (mAb) is to reach high solution concentrations without compromising stability. Protein surface activity leading to instability is well known, but our understanding of mAb adsorption to the solid-liquid interface in relevant pH and surfactant conditions is incomplete. To investigate these conditions, we used total internal reflection fluorescence (TIRF) and neutron reflectometry (NR). The mAb tested ("mAb-1") showed highest surface loading to silica at pH 7.4 (~12 mg/m(2)), with lower surface loading at pH 5.5 (~5.5 mg/m(2), further from its pI of 8.99) and to hydrophobized silica (~2 mg/m(2)). The extent of desorption of mAb-1 from silica or hydrophobized silica was related to the relative affinity of polysorbate 20 or 80 for the same surface. mAb-1 adsorbed to silica on co-injection with polysorbate (above its critical micelle concentration) and also to silica pre-coated with polysorbate. A bilayer model was developed from NR data for mAb-1 at concentrations of 50-5000 mg/L, pH 5.5, and 50-2000 mg/L, pH 7.4. The inner mAb-1 layer was adsorbed to the SiO₂ surface at near saturation with an end-on" orientation, while the outer mAb-1 layer was sparse and molecules had a "side-on" orientation. A non-uniform triple layer was observed at 5000 mg/L, pH 7.4, suggesting mAb-1 adsorbed to the SiO₂ surface as oligomers at this concentration and pH. mAb-1 adsorbed as a sparse monolayer to hydrophobized silica, with a layer thickness increasing with bulk concentration - suggesting a near end-on orientation without observable relaxation-unfolding.

  16. Adsorption behavior of a human monoclonal antibody at hydrophilic and hydrophobic surfaces

    Science.gov (United States)

    Couston, Ruairidh G.; Skoda, Maximilian W.; Uddin, Shahid; van der Walle, Christopher F.

    2013-01-01

    One aspiration for the formulation of human monoclonal antibodies (mAb) is to reach high solution concentrations without compromising stability. Protein surface activity leading to instability is well known, but our understanding of mAb adsorption to the solid-liquid interface in relevant pH and surfactant conditions is incomplete. To investigate these conditions, we used total internal reflection fluorescence (TIRF) and neutron reflectometry (NR). The mAb tested (“mAb-1”) showed highest surface loading to silica at pH 7.4 (~12 mg/m2), with lower surface loading at pH 5.5 (~5.5 mg/m2, further from its pI of 8.99) and to hydrophobized silica (~2 mg/m2). The extent of desorption of mAb-1 from silica or hydrophobized silica was related to the relative affinity of polysorbate 20 or 80 for the same surface. mAb-1 adsorbed to silica on co-injection with polysorbate (above its critical micelle concentration) and also to silica pre-coated with polysorbate. A bilayer model was developed from NR data for mAb-1 at concentrations of 50–5000 mg/L, pH 5.5, and 50–2000 mg/L, pH 7.4. The inner mAb-1 layer was adsorbed to the SiO2 surface at near saturation with an end-on” orientation, while the outer mAb-1 layer was sparse and molecules had a “side-on” orientation. A non-uniform triple layer was observed at 5000 mg/L, pH 7.4, suggesting mAb-1 adsorbed to the SiO2 surface as oligomers at this concentration and pH. mAb-1 adsorbed as a sparse monolayer to hydrophobized silica, with a layer thickness increasing with bulk concentration - suggesting a near end-on orientation without observable relaxation-unfolding. PMID:23196810

  17. Pharmacokinetics and leukocyte responses of recombinant human interleukin-10.

    Science.gov (United States)

    Radwanski, E; Chakraborty, A; Van Wart, S; Huhn, R D; Cutler, D L; Affrime, M B; Jusko, W J

    1998-12-01

    To study the pharmacokinetics and ex vivo leukocyte responses of recombinant human IL-10 (rHuIL-10) following single s.c. and i.v. dosing. A randomized two-way cross-over study was undertaken in 17 healthy volunteers in which rHuIL-10 was administered as 25 microg/kg s.c. and i.v. doses. Blood samples were collected for 48 hr after dosing to determine serum IL-10 concentrations. Inhibitory activity of IL-10 on ex vivo production of inflammatory cytokines (TNF-alpha and IL-1beta) by LPS-treated peripheral blood cells were measured over 96 hr. A physiologically-relevant modeling approach was developed to determine the pharmacokinetics for two routes of administration (s.c. and i.v.). The i.v. dose showed polyexponential disposition with CL of 65 mL/kg/hr, Vss of 70 mL/kg, and t1/2 of 1.94 hr. Absolute bioavailability averaged 42% for s.c. dosing which produced lower but sustained concentrations. Substantial and prolonged suppression of TNF-alpha and IL-1beta production was achieved during IL-10 treatment. The Hill Function was used to account for the joint concentration-dependent immunosuppressive action of rHuIL-10 after both i.v. and s.c. doses. The IC50 values were about 0.03 ng/ml and Imax values were about 0.85 for both TNF-alpha and IL-1beta suppression. The degree of change as well as the duration of leukocyte response was greater after s.c. administration than after i.v. administration. rHuIL-10 shows favorable PKPD characteristics especially by the s.c. route of administration which produced prolonged suppression of cytokine production (ex vivo) which may be applicable in various immune-related disorders.

  18. Skeletal ligament healing using the recombinant human amelogenin protein.

    Science.gov (United States)

    Hanhan, Salem; Ejzenberg, Ayala; Goren, Koby; Saba, Faris; Suki, Yarden; Sharon, Shay; Shilo, Dekel; Waxman, Jacob; Spitzer, Elad; Shahar, Ron; Atkins, Ayelet; Liebergall, Meir; Blumenfeld, Anat; Deutsch, Dan; Haze, Amir

    2016-05-01

    Injuries to ligaments are common, painful and debilitating, causing joint instability and impaired protective proprioception sensation around the joint. Healing of torn ligaments usually fails to take place, and surgical replacement or reconstruction is required. Previously, we showed that in vivo application of the recombinant human amelogenin protein (rHAM(+)) resulted in enhanced healing of the tooth-supporting tissues. The aim of this study was to evaluate whether amelogenin might also enhance repair of skeletal ligaments. The rat knee medial collateral ligament (MCL) was chosen to prove the concept. Full thickness tear was created and various concentrations of rHAM(+), dissolved in propylene glycol alginate (PGA) carrier, were applied to the transected MCL. 12 weeks after transection, the mechanical properties, structure and composition of transected ligaments treated with 0.5 μg/μl rHAM(+) were similar to the normal un-transected ligaments, and were much stronger, stiffer and organized than control ligaments, treated with PGA only. Furthermore, the proprioceptive free nerve endings, in the 0.5 μg/μl rHAM(+) treated group, were parallel to the collagen fibres similar to their arrangement in normal ligament, while in the control ligaments the free nerve endings were entrapped in the scar tissue at different directions, not parallel to the axis of the force. Four days after transection, treatment with 0.5 μg/μl rHAM(+) increased the amount of cells expressing mesenchymal stem cell markers at the injured site. In conclusion application of rHAM(+) dose dependently induced mechanical, structural and sensory healing of torn skeletal ligament. Initially the process involved recruitment and proliferation of cells expressing mesenchymal stem cell markers. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  19. A high-affinity human monoclonal IgM antibody reacting with multiple strains of Mycoplasma hominis

    DEFF Research Database (Denmark)

    Moller, SA; Birkelund, Svend; Borrebaeck, CA

    1990-01-01

    Human monoclonal antibodies were produced against Mycoplasma hominis by in vitro immunization of peripheral blood lymphocytes from a healthy seropositive donor using low amounts of antigen (5 ng/ml). The immune B lymphocytes were subsequently immortalized by Epstein-Barr virus transformation...... (24 hr x 10(6) cells)-1. The specificity of one antibody, 129.1, was further characterized by enzyme-linked immunosorbent assay against several different species of Mycoplasma and by Western blot analysis. The antibody specifically bound to a protein of Mr 100,000 present in 10 of 12 different strains...

  20. Stoichiometry of monoclonal antibody neutralization of T-cell line-adapted human immunodeficiency virus type 1

    DEFF Research Database (Denmark)

    Schønning, Kristian; Lund, O; Lund, O S

    1999-01-01

    In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes...... neutralization gradually increased. Virus neutralization by virion aggregation was minimal, as MAb binding to HIV-1 Env did not interfere with an AMLV Env-mediated infection by HIV-1(AMLV/HIV-1) pseudotypes of CD4(-) HEK293 cells. MAb neutralization of chimeric virions could be described as a third...

  1. De novo protein sequencing, humanization and in vitro effects of an antihuman CD34 mouse monoclonal antibody.

    Science.gov (United States)

    Fan, Chia-Yu; Huang, Sheng-Yu; Chou, Min-Yuan; Lyu, Ping-Chiang

    2017-03-01

    QBEND/10 is a mouse immunoglobulin lambda-chain monoclonal antibody with strict specificity against human hematopoietic progenitor cell antigen CD34. Our in vitro study showed that QBEND/10 impairs the tube formation of human umbilical vein endothelial cells (HUVECs), suggesting that the antibody may be of potential benefit in blocking tumor angiogenesis. We provided a de novo protein sequencing method through tandem mass spectrometry to identify the amino acid sequences in the variable heavy and light chains of QBEND/10. To reduce immunogenicity for clinical applications, QBEND/10 was further humanized using the resurfacing approach. We demonstrate that the de novo sequenced and humanized QBEND/10 retains the biological functions of the parental mouse counterpart, including the binding kinetics to CD34 and blockage of the tube formation of the HUVECs.

  2. Iron Oxidation and Core Formation in Recombinant Heteropolymeric Human Ferritins.

    Science.gov (United States)

    Mehlenbacher, Matthew; Poli, Maura; Arosio, Paolo; Santambrogio, Paolo; Levi, Sonia; Chasteen, N Dennis; Bou-Abdallah, Fadi

    2017-08-01

    In animals, the iron storage and detoxification protein, ferritin, is composed of two functionally and genetically distinct subunit types, H (heavy) and L (light), which co-assemble in various ratios with tissue specific distributions to form shell-like protein structures of 24 subunits within which a mineralized iron core is stored. The H-subunit possesses a ferroxidase center (FC) that catalyzes Fe(II) oxidation, whereas the L-subunit does not. To assess the role of the L-subunit in iron oxidation and core formation, two human recombinant heteropolymeric ferritins, designated H-rich and L-rich with ratios of ∼20H:4L and ∼22L:2H, respectively, were employed and compared to the human homopolymeric H-subunit ferritin (HuHF). These heteropolymeric ferritins have a composition similar to the composition of those found in hearts and brains (i.e., H-rich) and in livers and spleens (i.e., L-rich). As for HuHF, iron oxidation in H-rich ferritin was found to proceed with a 2:1 Fe(II):O2 stoichiometry at an iron level of 2 Fe(II) atoms/H-subunit with the generation of H2O2. The H2O2 reacted with additional Fe(II) in a 2:1 Fe(II):H2O2 ratio, thus avoiding the production of hydroxyl radical. A μ-1,2-peroxo-diFe(III) intermediate was observed at the FC of H-rich ferritin as for HuHF. Importantly, the H-rich protein regenerated full ferroxidase activity more rapidly than HuHF did and additionally formed larger iron cores, indicating dual roles for the L-subunit in facilitating iron turnover at the FC and in mineralization of the core. The L-rich ferritin, while also facilitating iron oxidation at the FC, additionally promoted oxidation at the mineral surface once the iron binding capacity of the FC was exceeded.

  3. High-yield production of a human monoclonal IgG by rhizosecretion in hydroponic tobacco cultures

    NARCIS (Netherlands)

    Madeira, L.M.; Szeto, T.H.; Henquet, Maurice; Raven, Nicole; Runions, John; Huddleston, Jon; Garrard, Ian; Drake, P.M.W.; Ma, Julian K.C.

    2016-01-01

    Rhizosecretion of recombinant pharmaceuticals from in vitro hydroponic transgenic plant cultures is a simple, low cost, reproducible and controllable production method. Here, we demonstrate the application and adaptation of this manufacturing platform to a human antivitronectin IgG1

  4. B-cell display-based one-step method to generate chimeric human IgG monoclonal antibodies.

    Science.gov (United States)

    Lin, Waka; Kurosawa, Kohei; Murayama, Akiho; Kagaya, Eri; Ohta, Kunihiro

    2011-02-01

    The recent development of screening strategies based on the generation and display of large libraries of antibody fragments has allowed considerable advances for the in vitro isolation of monoclonal antibodies (mAbs). We previously developed a technology referred to as the 'ADLib (Autonomously Diversifying Library) system', which allows the rapid screening and isolation in vitro of antigen-specific monoclonal antibodies (mAbs) from libraries of immunoglobulin M (IgM) displayed by the chicken B-cell line DT40. Here, we report a novel application of the ADLib system to the production of chimeric human mAbs. We have designed gene knock-in constructs to generate DT40 strains that coexpress chimeric human IgG and chicken IgM via B-cell-specific RNA alternative splicing. We demonstrate that the application of the ADLib system to these strains allows the one-step selection of antigen-specific human chimeric IgG. In addition, the production of chimeric IgG can be selectively increased when we modulate RNA processing by overexpressing the polyadenylation factor CstF-64. This method provides a new way to efficiently design mAbs suitable for a wide range of purposes including antibody therapy.

  5. The human leucocyte-common (LC) molecule: dissection of leukaemias using monoclonal antibodies directed against framework and restricted antigenic determinants.

    Science.gov (United States)

    Ritter, M A; Sauvage, C A; Pegram, S M; Myers, C D; Dalchau, R; Fabre, J W

    1985-01-01

    Monoclonal antibodies have previously been raised against two separate antigenic determinants on the human LC molecule. One, F10.89.4, recognizes a 'framework' epitope on all LC molecules; these are found on the majority of leucocytes. The other, F8.11.13, recognizes only a 'restricted' epitope present on a subset of these molecules; this subset is found on B lymphocytes and a subpopulation of T lymphocytes. LC molecules on myeloid cells do not carry the 'restricted' antigenic determinant. We have investigated the differential expression of these LC epitopes on human leukaemias, using immunofluorescence on fresh leukaemic blasts and established cell lines. Our study shows that, as on normal haemopoietic cells, LC molecules on B leukaemias bear both 'framework' and 'restricted' epitopes, while the majority of T leukaemias bear only the 'framework' determinant. The small proportion of T cells that are F8.11.13+ ('restricted' epitope) are relatively mature, being of either OKT4+ or OKT8+ phenotype, and may be in an activated state (HLA-DR+). However, in contrast to normal haemopoietic cells, some myeloid leukaemias carry both 'framework' and 'restricted' epitopes (30% AML and AMML samples are F10.89.4+, F8.11.13+), and it is within this group that all TdT+ AML and AMML cases lie. Thus, these monoclonal antibodies should be useful for studying haemopoiesis in man and for analyzing human haemopoietic malignancies.

  6. From Monoclonal Antibodies to Chimeric Antigen Receptors for the Treatment of Human Malignancies

    OpenAIRE

    Caruana, Ignazio; Diaconu, Iulia; Dotti, Gianpietro

    2014-01-01

    Monoclonal antibodies (mAbs) and their directly derived cell-based application known as chimeric antigen receptors (CARs) ensue from the need to develop novel therapeutic strategies that retain high anti-tumor activity, but carry reduced toxicity compared to conventional chemo- and radio-therapies. In this concise review article we will summarize the application of antibodies designed to target antigens expressed by tumor cells, and the transition from these antibodies to the generation of CARs.

  7. 76 FR 65210 - Certain Products and Pharmaceutical Compositions Containing Recombinant Human Erythropoetin...

    Science.gov (United States)

    2011-10-20

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Products and Pharmaceutical Compositions Containing Recombinant Human Erythropoetin... sale within the United States after importation of certain products and pharmaceutical compositions...

  8. Pharmacoeconomic review of recombinant human DNase in the management of cystic fibrosis

    NARCIS (Netherlands)

    Zijlstra, Gerrit; Boersma, Cornelis; Frijlink, Henderik W.; Postma, Maarten J.

    For the treatment of patients with cystic fibrosis, recombinant human deoxyribonuclease I is widely used. Deoxyribonuclease I has a positive effect on lung function and the number of hospitalizations. Deoxyribonuclease I is currently administered by nebulization, which is an inefficient

  9. Comparison of the Genetic Recombination Rates of Human Immunodeficiency Virus Type 1 in Macrophages and T Cells†

    OpenAIRE

    Chen, Jianbo; Rhodes, Terence D.; Hu, Wei-Shau

    2005-01-01

    Human immunodeficiency virus type 1 (HIV-1) exhibits a high level of genetic variation generated by frequent mutation and genetic recombination during reverse transcription. We have measured HIV-1 recombination rates in T cells in one round of virus replication. It was recently proposed that HIV-1 recombines far more frequently in macrophages than in T cells. In an attempt to delineate the mechanisms that elevate recombination, we measured HIV-1 recombination rates in macrophages at three dif...

  10. Generation of glyco-engineered Nicotiana benthamiana for the production of monoclonal antibodies with a homogeneous human-like N-glycan structure.

    Science.gov (United States)

    Strasser, Richard; Stadlmann, Johannes; Schähs, Matthias; Stiegler, Gabriela; Quendler, Heribert; Mach, Lukas; Glössl, Josef; Weterings, Koen; Pabst, Martin; Steinkellner, Herta

    2008-05-01

    A common argument against using plants as a production system for therapeutic proteins is their inability to perform authentic human N-glycosylation (i.e. the presence of beta1,2-xylosylation and core alpha1,3-fucosylation). In this study, RNA interference (RNAi) technology was used to obtain a targeted down-regulation of the endogenous beta1,2-xylosyltransferase (XylT) and alpha1,3-fucosyltransferase (FucT) genes in Nicotiana benthamiana, a tobacco-related plant species widely used for recombinant protein expression. Three glyco-engineered lines with significantly reduced xylosylated and/or core alpha1,3-fucosylated glycan structures were generated. The human anti HIV monoclonal antibody 2G12 was transiently expressed in these glycosylation mutants as well as in wild-type plants. Four glycoforms of 2G12 differing in the presence/absence of xylose and core alpha1,3-fucose residues in their N-glycans were produced. Notably, 2G12 produced in XylT/FucT-RNAi plants was found to contain an almost homogeneous N-glycan species without detectable xylose and alpha1,3-fucose residues. Plant-derived glycoforms were indistinguishable from Chinese hamster ovary (CHO)-derived 2G12 with respect to electrophoretic properties, and exhibited functional properties (i.e. antigen binding and HIV neutralization activity) at least equivalent to those of the CHO counterpart. The generated RNAi lines were stable, viable and did not show any obvious phenotype, thus providing a robust tool for the production of therapeutically relevant glycoproteins in plants with a humanized N-glycan structure.

  11. Reactivity of commercially available monoclonal antibodies to human CD antigens with peripheral blood leucocytes of dromedary camels (Camelus dromedarius

    Directory of Open Access Journals (Sweden)

    Jamal Hussen

    2017-05-01

    Full Text Available Monoclonal antibodies (mAbs to cell surface molecules have been proven as a key tool for phenotypic and functional characterization of the cellular immune response. One of the major difficulties in studying camel cellular immunity consists in the lack of mAbs that dtect their leukocyte differentiation antigens. In the present study two-parameter flow cytometry was used to screen existing commercially available mAbs to human leukocyte antigens and major histocompatibility molecules (MHC for their reactivity with camel leukocytes. The comparison of patterns of reactivity obtained after labelling human and camel leukocytes have shown that mAbs specific to human cluster of differentiation (CD 18, CD11a, CD11b and CD14 are predicted to be cross-reactive with homologous camel antigens.

  12. A high affinity recombinant antibody to the human EphA3 receptor with enhanced ADCC activity.

    Science.gov (United States)

    Tomasevic, Nenad; Luehrsen, Kenneth; Baer, Mark; Palath, Varghese; Martinez, David; Williams, Jason; Yi, Christina; Sujatha-Bhaskar, Swathi; Lanke, Rohini; Leung, John; Ching, Wendy; Lee, Andreia; Bai, Lu; Yarranton, Geoffrey; Bebbington, Christopher

    2014-12-01

    EphA3 is expressed in solid tumors and leukemias and is an attractive target for the therapy. We have generated a panel of Humaneered® antibodies to the ligand-binding domain using a Fab epitope-focused library that has the same specificity as monoclonal antibody mIIIA4. A high-affinity antibody was selected that competes with the mIIIA4 antibody for binding to EphA3 and has an improved affinity of ∼1 nM. In order to generate an antibody with potent cell-killing activity the variable regions were assembled with human IgG1k constant regions and expressed in a Chinese hamster ovary (CHO) cell line deficient in fucosyl transferase. Non-fucosylated antibodies have been reported to have enhanced binding affinity for the IgG receptor CD16a (FcγRIIIa). The affinity of the antibody for recombinant CD16a was enhanced approximately 10-fold. This resulted in enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) activity against EphA3-expressing leukemic cells, providing a potent antibody for the evaluation as a therapeutic agent.

  13. Is the use of recombinant human erythropoietin in anaemia of ...

    African Journals Online (AJOL)

    In a double-blind placebo-eontrolled study we showed a 3-fold decrease in blood transfusions (BTFs) given to preterm infants with anaemia of prematurity who received recombinant erythropoietin. However, only 50% of placebo recipients required a BTF. Data from the placebo group indicated that either mean daily weight ...

  14. Laboratory scale production of the human recombinant iduronate 2 ...

    African Journals Online (AJOL)

    sulfate sulfatase-Like (hIDSLike) was employed for low-scale production of the recombinant enzyme in a saline culture media without phosphate. The biological activity found was between 7.3 and 29.5 nmol h-1 mg-1 of total protein. It is about 1.73 ...

  15. Recombinant expression and purification of L2 domain of human ...

    African Journals Online (AJOL)

    USER

    2010-08-16

    Aug 16, 2010 ... 5Pharmaceutical Nanotechnology Research Center, Tabriz University of Medical sciences, Tabriz, Iran. Accepted 7 May ... extracted and used for amplification of the sequence coding for L2 domain of EGFR by reverse ... This recombinant protein can be used for the production of specific mAb, screening for.

  16. Artificial restriction DNA cutters to promote homologous recombination in human cells.

    Science.gov (United States)

    Katada, Hitoshi; Komiyama, Makoto

    2011-02-01

    Homologous recombination is almost the only way to modify the genome in a predetermined fashion, despite its quite low frequency in mammalian cells. It has been already reported that the frequency of this biological process can be notably increased by inducing a double strand break (DSB) at target site. This article presents completely chemistry-based artificial restriction DNA cutter (ARCUT) for the promotion of homologous recombination in human cells. This cutter is composed of Ce(IV)/EDTA complex (molecular scissors) and two strands of peptide nucleic acid (PNA), and contains no proteins. Its scission site in the genome is determined simply by Watson-Crick rule so that ARCUT for desired homologous recombination is easily and straightforwardly designed and synthesized. The site-specificity of the scission is high enough to cut human genome at one target site. The DSB induced by this cutter is satisfactorily recognized by the repair system in human cells and promotes the targeted homologous recombination.

  17. High-level secretion of native recombinant human calreticulin in yeast

    DEFF Research Database (Denmark)

    Čiplys, Evaldas; Žitkus, Eimantas; Gold, Leslie I.

    2015-01-01

    processes with presence both inside and outside of the ER, including the cell surface and extracellular space. These recent findings suggest the possible use of this ER chaperone in development of new therapeutic pharmaceuticals. Our study was focused on human CRT production in two yeast species...... quality of the yeast-derived CRTs, we compared yeast-secreted human recombinant CRT with native CRT isolated from human placenta. In ESI-MS (electrospray ionization mass spectrometry), both native and recombinant full-length CRT showed an identical molecular weight (mass) of 46,466 Da and were monomeric...... by non-denaturing PAGE. Moreover, limited trypsin digestion yielded identical fragment patterns of calcium-binding recombinant and native CRT suggesting that the yeast-derived CRT was correctly folded. Furthermore, both native and recombinant CRT induced cellular proliferation (MTS assay) and migration...

  18. Germline humanization of a murine Aβ antibody and crystal structure of the humanized recombinant Fab fragment

    Science.gov (United States)

    Robert, Remy; Streltsov, Victor A; Newman, Janet; Pearce, Lesley A; Wark, Kim L; Dolezal, Olan

    2010-01-01

    Alzheimer's disease is the most common form of dementia, affecting 26 million people worldwide. The Aβ peptide (39–43 amino acids) derived from the proteolytic cleavage of the amyloid precursor protein is one of the main constituents of amyloid plaques associated with disease pathogenesis and therefore a validated target for therapy. Recently, we characterized antibody fragments (Fab and scFvs) derived from the murine monoclonal antibody WO-2, which bind the immunodominant epitope (3EFRH6) in the Aβ peptide at the N-terminus. In vitro, these fragments are able to inhibit fibril formation, disaggregate preformed amyloid fibrils, and protect neuroblastoma cells against oligomer-mediated toxicity. In this study, we describe the humanization of WO-2 using complementary determining region loop grafting onto the human germline gene and the determination of the three-dimensional structure by X-ray crystallography. This humanized version retains a high affinity for the Aβ peptide and therefore is a potential candidate for passive immunotherapy of Alzheimer's disease. PMID:20014445

  19. Monoclonal antibodies that define canine homologues of human CD antigens: summary of the First International Canine Leukocyte Antigen Workshop (CLAW).

    Science.gov (United States)

    Cobbold, S; Metcalfe, S

    1994-03-01

    A panel of 127 monoclonal antibodies against canine leukocyte antigens, including controls, was distributed to 29 laboratories that performed a variety of experiments to identify groups of antibodies against the canine equivalents of some of the human CD antigens. Cluster analysis was performed centrally, using the submitted antibody binding data from immunofluorescence, ELISA and immuno-histology experiments. Immunoprecipitation for molecular weight determination was also performed centrally with T-cell blasts and a B-cell line as the sources of antigen. Clusters of three or more antibodies were found that defined the canine equivalents of the CD5, CD4, CD8 and Thy-1 antigens, and these could be used to label T-cell subsets from the peripheral blood. Other groups of monoclonal antibodies recognized the canine homologues of the CD11/18 group of antigens, CD44 and the CD45/CD45R antigen family: these should be useful in isolating functional subsets of CD4+ helper T cells. There was a cluster of four antibodies that bound strongly to platelets (probably CD41 antigen), three antibodies that were specific to B cells (including CD21) and two antibodies against a granulocyte antigen (possibly CD15). A number of reagents were found against canine MHC-II and immunoglobulin, with some of the latter able to distinguish between Ig subclasses. Properties of each of the canine antigens defined by these monoclonal antibodies are discussed and compared with other species. The availability of such a panel of reagents should allow rapid improvements in the immunological diagnosis of canine disease, and there might now be a potential for testing novel therapeutic strategies in a clinical veterinary setting.

  20. From monoclonal antibodies to chimeric antigen receptors for the treatment of human malignancies.

    Science.gov (United States)

    Caruana, Ignazio; Diaconu, Iulia; Dotti, Gianpietro

    2014-10-01

    Monoclonal antibodies (mAbs) and their directly derived cell-based application known as chimeric antigen receptors (CARs) ensue from the need to develop novel therapeutic strategies that retain high anti-tumor activity, but carry reduced toxicity compared to conventional chemo- and radiotherapies. In this concise review article, we will summarize the application of antibodies designed to target antigens expressed by tumor cells, and the transition from these antibodies to the generation of CARs. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. High-avidity monoclonal antibodies against the human scavenger class B type I receptor efficiently block hepatitis C virus infection in the presence of high-density lipoprotein.

    Science.gov (United States)

    Catanese, Maria Teresa; Graziani, Rita; von Hahn, Thomas; Moreau, Martine; Huby, Thierry; Paonessa, Giacomo; Santini, Claudia; Luzzago, Alessandra; Rice, Charles M; Cortese, Riccardo; Vitelli, Alessandra; Nicosia, Alfredo

    2007-08-01

    The human scavenger class B type 1 receptor (SR-B1/Cla1) was identified as a putative receptor for hepatitis C virus (HCV) because it binds to soluble recombinant HCV envelope glycoprotein E2 (sE2). High-density lipoprotein (HDL), a natural SR-B1 ligand, was shown to increase the in vitro infectivity of retroviral pseudoparticles bearing HCV envelope glycoproteins and of cell culture-derived HCV (HCVcc), suggesting that SR-B1 promotes viral entry in an HDL-dependent manner. To determine whether SR-B1 participates directly in HCV infection or facilitates HCV entry through lipoprotein uptake, we generated a panel of monoclonal antibodies (MAbs) against native human SR-B1. Two of them, 3D5 and C167, bound to conformation-dependent SR-B1 determinants and inhibited the interaction of sE2 with SR-B1. These antibodies efficiently blocked HCVcc infection of Huh-7.5 hepatoma cells in a dose-dependent manner. To examine the role of HDL in SR-B1-mediated HCVcc infection, we set up conditions for HCVcc production and infection in serum-free medium. HCVcc efficiently infected Huh-7.5 cells in the absence of serum lipoproteins, and addition of HDL led to a twofold increase in infectivity. However, the HDL-induced enhancement of infection had no impact on the neutralization potency of MAb C167, despite its ability to inhibit both HDL binding to cells and SR-B1-mediated lipid transfer. Of note, MAb C167 also potently blocked Huh-7.5 infection by an HCV strain recovered from HCVcc-infected chimpanzees. These results demonstrate that SR-B1 is essential for infection with HCV produced in vitro and in vivo and suggest the possible use of anti-SR-B1 antibodies as therapeutic agents.

  2. Cross-protection of newly emerging HPAI H5 viruses by neutralizing human monoclonal antibodies: A viable alternative to oseltamivir.

    Science.gov (United States)

    Ren, Huanhuan; Wang, Guiqin; Wang, Shuangshuang; Chen, Honglin; Chen, Zhiwei; Hu, Hongxing; Cheng, Genhong; Zhou, Paul

    2016-01-01

    Newly emerging highly pathogenic avian influenza (HPAI) H5N2, H5N3, H5N5, H5N6, H5N8 and H5N9 viruses have been spreading in poultry and wild birds. The H5N6 viruses have also caused 10 human infections with 4 fatal cases in China. Here, we assessed the cross-neutralization and cross-protection of human and mouse monoclonal antibodies against 2 viruses: a HPAI H5N8 virus, A/chicken/Netherlands/14015526/2014 (NE14) and a HPAI H5N6 virus, A/Sichuan/26221/2014 (SC14). The former was isolated from an infected chicken in Netherlands in 2014 and the latter was isolated from an infected human patient in Sichuan, China. We show that antibodies FLA5.10, FLD21.140, 100F4 and 65C6, but not AVFluIgG01, AVFluIgG03, S139/1 and the VRC01 control, potently cross-neutralize the H5N8 NE14 and H5N6 SC14 viruses. Furthermore, we show that a single injection of >1 mg/kg of antibody 100F4 at 4 hours before, or 20 mg/kg antibody 100F4 at 72 hours after, a lethal dose of H5N8 NE14 enables mice to withstand the infection. Finally, we show that a single injection of 0.5 or 1 mg/kg antibody 100F4 prophylactically or 10 mg/kg 100F4 therapeutically outperforms a 5-day course of 10 mg/kg/day oseltamivir treatment against lethal H5N8 NE14 or H5N6 SC14 infection in mice. Our results suggest that further preclinical evaluation of human monoclonal antibodies against newly emerging H5 viruses is warranted.

  3. Immunologic analysis of human breast cancer progesterone receptors. 1. Immunonaffinity purification of transformed receptors and production of monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Estes, P.A.; Suba, E.J.; Lawler-Heavner, J.; Elashry-Stowers, D.; Wei, L.L.; Toft, D.O.; Sullivan, W.P.; Horwitz, K.B.; Edwards, D.P.

    1987-09-22

    A monoclonal antibody (MAb), designated PR-6, produced against chick oviduct progesterone receptors cross-reacts with the M/sub r/ 120,000 human B receptors. An immunomatrix prepared with PR-6 was used to purify progesterone receptors (PR) from T47D human breast cancer cells. Single-step immunoaffinity chromatography results in enrichment of B receptors (identified by immunoblot with PR-6 and by photoaffinity labeling with (/sup 3/H)promegestone) to a specific activity of 1915 pmol/mg of protein (or 23% purity) and with 27% yield. Purity and yields as judged by gel electrophoresis and densitometric scanning of the B protein were approximately 1.7-fold higher due to partial loss in hormone binding activity at the elution step. B receptors purified under these conditions are transformed and biologically active. They were maintained as undergraded 120-kDa doublets and retained both hormone and DNA binding activities. These purified B receptors were used as immunogen for production of four monoclonal antibodies against human PR. Three of the MAbs, designated as B-30 (IgG/sub 1/), B-64 (IgG/sub 1/), and B-11 (IgM), are specific for B receptors. The fourth MAb, A/B-52 (IgG/sub 1/), reacts with both A and B receptors. The IgG MAbs are monospecific for human PR since they recognize and absorb native receptor-hormone complexes, displace the sedimentation of 4S receptors on salt containing sucrose gradients, and, by immunoblot assay of crude T47D cytosol, react only with receptor polypeptides. Although mice were injected with B receptors only, production of A/B-52 which recognized both A and B receptors provides evidence that these two proteins share regions of structural homology.

  4. Evidence for substantial fine-scale variation in recombination rates across the human genome.

    Science.gov (United States)

    Crawford, Dana C; Bhangale, Tushar; Li, Na; Hellenthal, Garrett; Rieder, Mark J; Nickerson, Deborah A; Stephens, Matthew

    2004-07-01

    Characterizing fine-scale variation in human recombination rates is important, both to deepen understanding of the recombination process and to aid the design of disease association studies. Current genetic maps show that rates vary on a megabase scale, but studying finer-scale variation using pedigrees is difficult. Sperm-typing experiments have characterized regions where crossovers cluster into 1-2-kb hot spots, but technical difficulties limit the number of studies. An alternative is to use population variation to infer fine-scale characteristics of the recombination process. Several surveys reported 'block-like' patterns of diversity, which may reflect fine-scale recombination rate variation, but limitations of available methods made this impossible to assess. Here, we applied a new statistical method, which overcomes these limitations, to infer patterns of fine-scale recombination rate variation in 74 genes. We found extensive rate variation both within and among genes. In particular, recombination hot spots are a common feature of the human genome: 47% (35 of 74) of genes showed substantive evidence for a hot spot, and many more showed evidence for some rate variation. No primary sequence characteristics are consistently associated with precise hot-spot location, although G+C content and nucleotide diversity are correlated with local recombination rate.

  5. Cloning and Characterization of a Hybridoma Secreting a 4-(Methylnitrosamino-1-(3-pyridyl-1-butanone (NNK-Specific Monoclonal Antibody and Recombinant F(ab

    Directory of Open Access Journals (Sweden)

    Lawrence K. Silbart

    2013-03-01

    Full Text Available Smokeless tobacco products have been associated with increased risks of oro-pharyngeal cancers, due in part to the presence of tobacco-specific nitrosamines (TSNAs such as 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK. These potent carcinogens are formed during tobacco curing and as a result of direct nitrosation reactions that occur in the oral cavity. In the current work we describe the isolation and characterization of a hybridoma secreting a high-affinity, NNK-specific monoclonal antibody. A structurally-related benzoyl derivative was synthesized to facilitate coupling to NNK-carrier proteins, which were characterized for the presence of the N-nitroso group using the Griess reaction, and used to immunize BALB/c mice. Splenocytes from mice bearing NNK-specific antibodies were used to create hybridomas. Out of four, one was selected for subcloning and characterization. Approximately 99% of the monoclonal antibodies from this clone were competitively displaced from plate-bound NNKB conjugates in the presence of free NNK. The affinity of the monoclonal antibody to the NNKB conjugates was Kd = 2.93 nM as determined by surface plasmon resonance. Free nicotine was a poor competitor for the NNKB binding site. The heavy and light chain antibody F(ab fragments were cloned, sequenced and inserted in tandem into an expression vector, with an FMDV Furin 2A cleavage site between them. Expression in HEK 293 cells revealed a functional F(ab with similar binding features to that of the parent hybridoma. This study lays the groundwork for synthesizing transgenic tobacco that expresses carcinogen-sequestration properties, thereby rendering it less harmful to consumers.

  6. In silico design, construction and cloning of Trastuzumab humanized monoclonal antibody: A possible biosimilar for Herceptin

    Directory of Open Access Journals (Sweden)

    Soudabeh Akbarzadeh-Sharbaf

    2012-01-01

    Conclusions: This study was based on a recently developed technology for mAb expression in mammalian cells. The obtained constructs could be successfully used for biosimilar recombinant mAb production in CHO DG44 dihydrofolate reductase (DHFR gene deficient cell line in the suspension culture medium.

  7. An ultra-sensitive monoclonal antibody-based enzyme-linked immunosobent assay for dibutyl phthalate in human urinary

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lifang [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Science, Zhejiang University, Hangzhou 310058 (China); Lei, Yajing [Hangzhou EPIE Bio-detection Technology Limited, Hangzhou 310051 (China); Zhang, Dai; Ahmed, Shabbir [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Science, Zhejiang University, Hangzhou 310058 (China); Chen, Shuqing, E-mail: chenshuqing@zju.edu.cn [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Science, Zhejiang University, Hangzhou 310058 (China)

    2016-01-15

    Dibutyl phthalate (DBP) has been extensively used as a plasticizer in many daily products, which is highly toxic to human, notably affecting the reproductive and developmental function. As the previous method is expensive, time-consuming, low sensitivity and just focused on the environment. Present study was aimed to establish an ultra-sensitive and simple method based on good quality monoclonal antibody, applying to evaluate excretion level of DBP in urine samples of Chinese population directly. A monoclonal antibody was generated and characterized after fusion of myeloma cells with spleen cells isolated from BALB/c mouse. The mouse was previously immunized using a specially designed amino derivative of DBP conjugated with bovine serum albumin (BSA) as immunogen. Cross-reactivity values of the monoclonal antibody against DBP, di-isobutyl phthalate (DIBP) were observed 100% and 1.25%, while for dimethyl phthalate (DMP), butyl benzyl phthalate (BBP) and didecyl phthalate (DDP) the values were < 0.06%. The standard curve was constructed at 0–50 ng mL{sup −1} and good linearity (R{sup 2} = 0.994) was achieved. The observed IC{sub 50} (7.34 ng mL{sup −1}) and LOD (0.06 ng mL{sup −1}) values was improved 1000-fold to polyclonal antibody and 5-fold to other monoclonal antibodies. A total 1246 urine samples were analyzed and the detection frequency of DBP was observed 72.87% by ic-ELISA. The 95th percentile and mean concentration of DBP were 12.07 and 3.00 ng mL{sup −1}. Acceptable recovery rates of DBP were 97.8–114.3% and coefficients variation 5.93–11.09%. The concentrations of DBP in females were found significantly higher (p < 0.05) than males. Similarly, the DBP in middle aged and low educated individuals was found higher (p < 0.001) than the others. Considering the adverse health effects, DBP internal exposure in the Chinese population should be reduced. The ic-ELISA method has been proved as a cost effective, specific, and highly sensitive screening

  8. Isolation and characterization of a monoclonal anti CK-2 alpha subunit antibody of the IgG1 subclass

    DEFF Research Database (Denmark)

    Schmidt-Spaniol, I; Boldyreff, B; Issinger, O G

    1992-01-01

    A monoclonal antibody was produced against the recombinant human alpha subunit of CK-2. The antibody was of the IgG1 subclass and it was isolated from serum-free cell culture media and purified by affinity chromatography on Protein G Sepharose. The antibody can be used to detect specifically the ...

  9. Treatment of Crohn's disease with recombinant human interleukin 10 induces the proinflammatory cytokine interferon gamma

    NARCIS (Netherlands)

    Tilg, H.; van Montfrans, C.; van den Ende, A.; Kaser, A.; van Deventer, S. J. H.; Schreiber, S.; Gregor, M.; Ludwiczek, O.; Rutgeerts, P.; Gasche, C.; Koningsberger, J. C.; Abreu, L.; Kuhn, I.; Cohard, M.; LeBeaut, A.; Grint, P.; Weiss, G.

    2002-01-01

    Interleukin 10 (IL-10) exerts anti-inflammatory actions by counteracting many biological effects of interferon gamma (IFN-gamma). To investigate this in humans, we studied the effects of human recombinant IL-10 administration on IFN-gamma production by patient leucocytes. Furthermore, we assessed

  10. [Cloning, ligation and expression of the variable region genes of the monoclonal antibody against human HnRNPA2/B1].

    Science.gov (United States)

    Wang, Xia; Peng, Xiao-dong; Li, Guang; Hu, Li-juan; Bi, Jian-hong

    2004-12-01

    To clone the variable region genes of the monoclonal antibody (McAb) against human heterogeneous nuclear ribonucleoprotein A2/B1 (HnRNPA2/B1), ligate them to assemble single chain Fv (ScFv) gene and express in Escherichia coli. The specificity of the anti-HnRNPA2/B1 McAb 3E8 to synthetic HnRNPA2/B1 peptide, HnRNPA2/B1 protein in lung cancer cells were examined by dot-immunobinding assay, Western blot and immunohistochemistry. The variable region genes of heavy chain (VH) and light chain (VL) were amplified from hybridoma cell by reverse transcription-polymerase chain reaction(RT-PCR), and then were linked by a linker peptide using SOE-PCR (splicing by overlap extension-PCR) to construct recombination ScFv gene. The latter was cloned into the expression vector pET28 (a+) and expressed in E coli BL21. The expressed product was identified by SDS-PAGE and competitive ELISA inhibition test. It was shown that the McAb combined specifically with synthetic HnRNPA2/B1 peptide and HnRNPA2/B1 protein in three lung cancer cells. The cloned VH gene and VL gene were 345 bp and 309 bp respectively and were linked successfully to obtain ScFv gene. The ScFv protein was expressed in the form of inclusion body, with molecular weight of 28,000 and immunoreactivity to HnRNPA2/B1. VH gene, VL gene and ScFv gene of anti-HnRNPA2/B1 antibody were cloned, constructed and functionally expressed in E coli. These results provide the experimental basis for elucidating the role of HnRNPA2/B1 in lung cancer.

  11. Human anti-V3 HIV-1 monoclonal antibodies encoded by the VH5-51/VL lambda genes define a conserved antigenic structure.

    Science.gov (United States)

    Gorny, Miroslaw K; Sampson, Jared; Li, Huiguang; Jiang, Xunqing; Totrov, Maxim; Wang, Xiao-Hong; Williams, Constance; O'Neal, Timothy; Volsky, Barbara; Li, Liuzhe; Cardozo, Timothy; Nyambi, Phillipe; Zolla-Pazner, Susan; Kong, Xiang-Peng

    2011-01-01

    Preferential usage of immunoglobulin (Ig) genes that encode antibodies (Abs) against various pathogens is rarely observed and the nature of their dominance is unclear in the context of stochastic recombination of Ig genes. The hypothesis that restricted usage of Ig genes predetermines the antibody specificity was tested in this study of 18 human anti-V3 monoclonal Abs (mAbs) generated from unrelated individuals infected with various subtypes of HIV-1, all of which preferentially used pairing of the VH5-51 and VL lambda genes. Crystallographic analysis of five VH5-51/VL lambda-encoded Fabs complexed with various V3 peptides revealed a common three dimensional (3D) shape of the antigen-binding sites primarily determined by the four complementarity determining regions (CDR) for the heavy (H) and light (L) chains: specifically, the H1, H2, L1 and L2 domains. The CDR H3 domain did not contribute to the shape of the binding pocket, as it had different lengths, sequences and conformations for each mAb. The same shape of the binding site was further confirmed by the identical backbone conformation exhibited by V3 peptides in complex with Fabs which fully adapted to the binding pocket and the same key contact residues, mainly germline-encoded in the heavy and light chains of five Fabs. Finally, the VH5-51 anti-V3 mAbs recognized an epitope with an identical 3D structure which is mimicked by a single mimotope recognized by the majority of VH5-51-derived mAbs but not by other V3 mAbs. These data suggest that the identification of preferentially used Ig genes by neutralizing mAbs may define conserved epitopes in the diverse virus envelopes. This will be useful information for designing vaccine immunogen inducing cross-neutralizing Abs.

  12. Idiotype vaccines against human T cell acute lymphoblastic leukemia. I. Generation and characterization of biologically active monoclonal anti-idiotopes.

    Science.gov (United States)

    Bhattacharya-Chatterjee, M; Pride, M W; Seon, B K; Kohler, H

    1987-08-15

    A murine monoclonal anti-tumor antibody termed SN2 (Ab1), isotype IgG1-kappa, that defines a unique human T cell leukemia-associated cell-surface glycoprotein, gp37 (m.w. 37,000), was used to generate monoclonal anti-idiotype antibodies (Ab2) in syngeneic BALB/c mice. The Ab2 were screened on the basis of their binding to the F(ab')2 fragments of SN2 and not to the F(ab')2 of pooled normal BALB/c mice sera IgG1 or to an unrelated BALB/c monoclonal antibody of the same isotype. Fifteen Ab2, obtained from two fusions, were specific for the SN2 idiotope and not against isotype or allotype determinants. To find out whether these Ab2 are directed against the paratope of SN2, the binding of radiolabeled SN2 to leukemic MOLT-4 and JM cells which contain gp37 as a surface constituent was studied in the presence of these anti-idiotopes. Clone 4EA2 inhibited the binding 100% at a concentration of 50 ng and 4DC6 inhibited 90% at a concentration of 250 ng. A third clone 4DD6 gave about 50% inhibition. Similar was the inhibition of SN2 binding to insolubilized MOLT-4 antigen or cell membrane preparation. The binding of SN2 (Ab1) to 4EA2 and 4DC6 was also inhibited by semipurified preparation of gp37 antigen. These results demonstrate that at least two of the anti-idiotope antibodies are binding either at or near the binding site idiotope of SN2. Next, the purified Ab2 was used to immunize syngeneic mice to induce antibody binding to MOLT-4 cells or gp37. Sera from mice immunized with 4EA2 and 4DC6 coupled to keyhole limpet hemocyanin contained antibodies which bind to semipurified gp37 antigen and MOLT-4 cells. Immune sera inhibited the binding of iodinated Ab2 and Ab1 indicating that an anti-anti-idiotopic antibody (Ab3) in mice shares idiotopes with Ab1 (SN2). Also, the binding of iodinated Ab2 to Ab1 was inhibited by rabbit antisera specific for gp37. Collectively, these data suggest that anti-idiotype antibodies 4EA2 and 4DC6 may be useful in the generation of idiotype

  13. Humanization of rabbit monoclonal antibodies via grafting combined Kabat/IMGT/Paratome complementarity-determining regions: Rationale and examples.

    Science.gov (United States)

    Zhang, Yi-Fan; Ho, Mitchell

    2017-04-01

    Rabbit monoclonal antibodies (RabMAbs) can recognize diverse epitopes, including those poorly immunogenic in mice and humans. However, there have been only a few reports on RabMAb humanization, an important antibody engineering step usually done before clinical applications are investigated. To pursue a general method for humanization of RabMAbs, we analyzed the complex structures of 5 RabMAbs with their antigens currently available in the Protein Data Bank, and identified antigen-contacting residues on the rabbit Fv within the 6 Angstrom distance to its antigen. We also analyzed the supporting residues for antigen-contacting residues on the same heavy or light chain. We identified "HV4" and "LV4" in rabbit Fvs, non-complementarity-determining region (CDR) loops that are structurally close to the antigen and located in framework 3 of the heavy chain and light chain, respectively. Based on our structural and sequence analysis, we designed a humanization strategy by grafting the combined Kabat/IMGT/Paratome CDRs, which cover most antigen-contacting residues, into a human germline framework sequence. Using this strategy, we humanized 4 RabMAbs that recognize poorly immunogenic epitopes in the cancer target mesothelin. Three of the 4 humanized rabbit Fvs have similar or improved functional binding affinity for mesothelin-expressing cells. Interestingly, 4 immunotoxins composed of the humanized scFvs fused to a clinically used fragment of Pseudomonas exotoxin (PE38) showed stronger cytotoxicity against tumor cells than the immunotoxins derived from their original rabbit scFvs. Our data suggest that grafting the combined Kabat/IMGT/Paratome CDRs to a stable human germline framework can be a general approach to humanize RabMAbs.

  14. Tratamiento con eritropoyetina humana recombinante Human recombinant erythropoietin therapy

    Directory of Open Access Journals (Sweden)

    Hugo Donato

    2006-02-01

    Full Text Available La eritropoyetina recombinante (rHuEPO se ha transformado en la citoquina más utilizada terapéuticamente en el mundo. Luego del éxito obtenido en pacientes con insuficiencia renal terminal, se pudo establecer la utilidad de la terapia con rHuEPO para mejorar otras anemias, incluso en pacientes pediátricos y neonatos. El tratamiento o la prevención de la anemia del prematuro mediante el uso de rHuEPO llevó a una significativa reducción en cantidad de transfusiones y en exposición a dadores. Aún debe establecerse una clara definición sobre cuáles niños prematuros deben recibir tratamiento rutinariamente. Otras indicaciones en período neonatal incluyen anemias hiporregenerativas y hemolíticas. La eficacia de la rHuEPO en niños mayores, con excepción de la insuficiencia renal crónica, no ha sido tan exhaustivamente evaluada como en adultos. Mientras que durante los últimos años se han realizado gran cantidad de estudios en adultos con anemia asociada al cáncer o a infección por HIV, permitiendo establecer conclusiones claras sobre su eficacia, sólo escasa cantidad de estudios con pequeño número de pacientes han sido realizados en niños. Hasta la fecha, los resultados sugieren que la terapia con rHuEPO en niños es tan útil como en adultos, pero la realización de estudios aleatorizados prospectivos incluyendo gran número de pacientes es esencial para alcanzar conclusiones definitivas. Los resultados de estudios dirigidos a evaluar la eficacia de la rHuEpo para mantener una dosis adecuada de ribavirina en pacientes en tratamiento por hepatitis C son alentadores. La utilización potencial de los efectos no hemopoyéticos de la rHuEPO en neonatos es un terreno novedoso y apasionante. El rol de la Epo como citoprotector para sistema nervioso central y mucosa intestinal está bajo investigación exhaustiva.Recombinant human erythropoietin (rHuEpo has become the most widely used cytokine in the world. Following the success of

  15. Generation of human monoclonal antibodies against ganglioside antigens and their applications in the diagnosis and therapy of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso, M. [Dept. of Tumor Cell Biology, Div. of Cancer Biology, Danish Cancer Society, Copenhagen (Denmark)]|[Dept. of Research and Development, Center of Molecular Immunology, Havana (Cuba); Zeuthen, J. [Dept. of Tumor Cell Biology, Div. of Cancer Biology, Danish Cancer Society, Copenhagen (Denmark)

    1996-10-01

    Different approaches to generating human monoclonal antibodies (MAbs) against tumor-associated ganglioside antigens have been carried out in several laboratories. A specific goal addressed by our laboratory is to produce human MAbs to several ganglioside antigens of relevance as therapeutic targets, such as the GM2, GD2, GD3 and GM3 gangliosides in melanoma. In vitro immunization of human B lymphocytes from normal donors was performed using liposomes containing gangliosides as the immunizing antigen combined with either complete tetanus toxoid or a synthetic peptide corresponding to a T helper epitope to stimulate in vitro immunization. Specific human anti-ganglioside antibodies were obtained, indicating that the antibdoy response found in vitro was antigen-driven. To overcome the widely reported problems concerning stability of immunoglobulin production by the antibody-secreting cell lines, a method of positive selection using GM3-coated magnetic beads has been developed in order to rescue unstable clones. Development of new methods to reproducibly generate ganglioside-specific human MAbs will amplify the possibilities for diagnostic and therapeutic applications. (orig.).

  16. [Evolution of monoclonal antibodies in cancer treatment].

    Science.gov (United States)

    Kubczak, Małgorzata; Rogalińska, Małgorzata

    Since late 90s of last century the new age of directed therapy began using mainly biological constructs produced in rodents called monoclonal antibodies. The side effects of monoclonal antibodies were a challenge for pharmaceutical companies to improve the biological properties of these biological drugs. The humanization of monoclonal constructs was an idea to improve monoclonal antibodies next generation activity cancer cell reduction in humans. Moreover for some other patients sensitive for monoclonal antibodies therapy could also potentially induce immunological differences that might imply on human health. The new idea related to monoclonal antibodies was to design a small molecule constructs of nanoantibodies with ability to enter into cells. Such small molecules could find their targets inside human cells, even in nuclei leading to differences in cancer cells expression. The existing knowledge on monoclonal antibodies as well as directed activity of nanoantibodies could improve anticancer treatment efficancy of diseases.

  17. 3-hydroxykynurenine-mediated modification of human lens proteins: structure determination of a major modification using a monoclonal antibody.

    Science.gov (United States)

    Staniszewska, Magdalena M; Nagaraj, Ram H

    2005-06-10

    Tryptophan can be oxidized in the eye lens by both enzymatic and non-enzymatic mechanisms. Oxidation products, such as kynurenines, react with proteins to form yellow-brown pigments and cause covalent cross-linking. We generated a monoclonal antibody against 3-hydroxykynurenine (3OHKYN)-modified keyhole limpet hemocyanin and characterized it using 3OHKYN-modified amino acids and proteins. This monoclonal antibody reacted with 3OHKYN-modified N(alpha)-acetyl lysine, N(alpha)-acetyl histidine, N(alpha)-acetyl arginine, and N(alpha)-acetyl cysteine. Among the several tryptophan oxidation products tested, 3OHKYN produced the highest concentration of antigen when reacted with human lens proteins. A major antigen from the reaction of 3OHKYN and N(alpha)-acetyl lysine was purified by reversed phase high pressure liquid chromatography, which was characterized by spectroscopy and identified as 2-amino-3-hydroxyl-alpha-((5S)-5-acetamino-5-carboxypentyl amino)-gamma-oxo-benzene butanoic acid. Enzyme-digested cataractous lens proteins displayed 3OHKYN-derived modifications. Immunohistochemistry revealed 3OHKYN modifications in proteins associated with the lens fiber cell plasma membrane. The low molecular products (<10,000 Da) isolated from normal lenses after reaction with glucosidase followed by incubation with proteins generated 3OHKYN-derived products. Human lens epithelial cells incubated with 3OHKYN showed intense immunoreactivity. We also investigated the effect of glycation on tryptophan oxidation and kynurenine-mediated modification of lens proteins. The results showed that glycation products failed to oxidize tryptophan or generate kynurenine modifications in proteins. Our studies indicate that 3OHKYN modifies lens proteins independent of glycation to form products that may contribute to protein aggregation and browning during cataract formation.

  18. Recombinant human endostatin normalizes tumor vasculature and enhances radiation response in xenografted human nasopharyngeal carcinoma models.

    Directory of Open Access Journals (Sweden)

    Fang Peng

    Full Text Available BACKGROUND: Hypoxic tumor cells can reduce the efficacy of radiation. Antiangiogenic therapy may transiently "normalize" the tumor vasculature to make it more efficient for oxygen delivery. The aim of this study is to investigate whether the recombinant human endostatin (endostar can create a "vascular normalization window" to alleviate hypoxia and enhance the inhibitory effects of radiation therapy in human nasopharyngeal carcinoma (NPC in mice. METHODOLOGY/PRINCIPAL FINDINGS: Transient changes in morphology of tumor vasculature and hypoxic tumor cell fraction in response to endostar were detected in mice bearing CNE-2 and 5-8F human NPC xenografts. Various treatment schedules were tested to assess the influence of endostar on the effect of radiation therapy. Several important factors relevant to the angiogenesis were identified through immunohistochemical staining. During endostar treatment, tumor vascularity decreased, while the basement membrane and pericyte coverage associated with endothelial cells increased, which supported the idea of vessel normalization. Hypoxic tumor cell fraction also decreased after the treatment. The transient modulation of tumor physiology caused by endostar improved the effect of radiation treatment compared with other treatment schedules. The expressions of vascular endothelial growth factor (VEGF, matrix metalloproteinase-2 (MMP-2, MMP-9, and MMP-14 decreased, while the level of pigment epithelium-derived factor (PEDF increased. CONCLUSIONS: Endostar normalized tumor vasculature, which alleviated hypoxia and significantly sensitized the function of radiation in anti-tumor in human NPC. The results provide an important experimental basis for combining endostar with radiation therapy in human NPC.

  19. Binding Affinity, Specificity and Comparative Biodistribution of the Parental Murine Monoclonal Antibody MX35 (Anti-NaPi2b) and Its Humanized Version Rebmab200

    DEFF Research Database (Denmark)

    Lindegren, Sture; Andrade, Luciana N S; Bäck, Tom

    2015-01-01

    The aim of this preclinical study was to evaluate the characteristics of the monoclonal antibody Rebmab200, which is a humanized version of the ovarian-specific murine antibody MX35. This investigation contributes to the foundation for future clinical α-radioimmunotherapy of minimal residual ovar...

  20. Intracerebral and subcutaneous xenografts of human sclc in the nude rat - comparison of monoclonal-antibody localization and tumor-infiltrating lymphocytes

    NARCIS (Netherlands)

    Bulte, J. W. M.; Go, K. Gwan; Zuiderveen, F.; The, T. Hauw; de Leij, Lou

    In the WAG/Rij nude rat, subcutaneous (s.c.) and intracerebral (i.c.) xenografts of the human SCLC cell line GLC-28 were evaluated for their growth behavior, in vivo monoclonal antibody binding and presence of tumor infiltrating lymphocytes. For the i.c. xenografts, two models of cerebral tumor

  1. In vivo activity of a mixture of two human monoclonal antibodies (anti-HBs) in a chronic hepatitis B virus carrier chimpanzee

    NARCIS (Netherlands)

    R. Heijtink; W. Paulij; P.A.C. van Bergen (Patrick); M.H. van Roosmalen (Mark); D. Rohm; B. Eichentopf; E. Muchmore; A.D.M.E. Osterhaus (Albert); R.A. de Man (Robert)

    1999-01-01

    textabstractA 35-year-old female hepatitis B virus carrier chimpanzee was infused with one dose of a mixture of human monoclonal antibodies 9H9 and 4-7B (antibodies against hepatitis B virus surface antigen; HBsAg). Blood samples were taken before and up to 3 weeks

  2. A panel of monoclonal antibodies against the prion protein proves that there is no prion protein in human pancreatic ductal epithelial cells.

    Science.gov (United States)

    Yang, Liheng; Zhang, Yan; Hu, Lipeng; Zhu, Ying; Sy, Man-Sun; Li, Chaoyang

    2014-08-01

    Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are monoclonal antibodies. Here, we characterize a panel of monoclonal antibodies specific for cellular prion protein by enzyme-linked immunosorbent assay (ELISA), immunofluorescent staining, flow cytometry, and western blotting. We identify several antibodies that can be used for specific applications and we demonstrate that there is no prion protein expression in human pancreatic ductal epithelial cells (HPDC).

  3. Short-term effect of recombinant human growth hormone in patients with alcoholic cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Becker, U; Grønbaek, M

    1994-01-01

    , and liver function. Twenty consecutive patients with cirrhosis were randomized to recombinant human growth hormone (Norditropin, 4 I.U. twice daily) subcutaneously for 6 weeks (n = 10) or conventional medical treatment (n = 10). The serum concentrations of insulin-like growth factor-I in the recombinant...... human growth hormone group increased after 3 (p group. The change in insulin-like growth factor-I during the treatment period was expressed as area under the curve (AUC). The AUCIGF-I was significantly larger...... in the recombinant human growth hormone group (median AUCIGF-I: 12.1, range: 0.0-54.7 weeks.nmol/l) than in the control group (median AUCIGF-I: 0.2, range: -10.6-9.9 weeks.nmol/l) (p

  4. Similarity of recombinant human perlecan domain 1 by alternative expression systems bioactive heterogenous recombinant human perlecan D1

    DEFF Research Database (Denmark)

    Ellis, April L; Pan, Wensheng; Yang, Guang

    2010-01-01

    structure analysis suggested helices and sheets in both recombinant species. rhPln.D1 demonstrated binding to rhFGF-2 with an apparent kD of 2 ± 0.2 nM with almost complete susceptibility to digestion by heparinase III in ligand blot analysis but not to chondroitinase digestion. Additionally, we demonstrate...... HS-mediated binding of both rhPln.D1 species to several other GFs. Finally, we corroborate the augmentation of FGF-mediated cell activation by rhPln.D1 and demonstrate mitogenic signalling through the FGFR1c receptor. CONCLUSIONS: With importance especially to the emerging field of DNA...

  5. Use of Recombinant Human Erythropoietin in Renal Anemia in Children

    Directory of Open Access Journals (Sweden)

    Habibur Rahman

    2009-11-01

    Full Text Available Erythropoietin is a hormone highly effective as like as natural erythropoietin to maintain target hemoglobin and hematocrit level in renal anemia. Its advantage over blood transfusion has been proved by improving the quality of life and decreasing morbidity and mortality in ESRD patients. Effectiveness of r-erythropoietin depends on absences of infection, inflammation and vitamin deficiency and iron status. Iron supplementation is needed before r-erythropoietin administration and sub-cutaneous rout is better in renal anemia because of slow and sustained releases of r-erythropoietin from the site of administration. Target hemoglobin level is 11-12.5 gm/dl and hematocrit is 33% which can be achieved by this hormone therapy. Key words- Recombinant erythropoietin, renal anemia, end stage renal disease.DOI: 10.3329/bsmmuj.v2i1.3713 BSMMU J 2009; 2(1: 50-53  

  6. Therapeutic Activity of Agonistic, Human Anti-CD40 Monoclonal Antibodies Requires Selective FcγR Engagement.

    Science.gov (United States)

    Dahan, Rony; Barnhart, Bryan C; Li, Fubin; Yamniuk, Aaron P; Korman, Alan J; Ravetch, Jeffrey V

    2016-06-13

    While engagement of the inhibitory Fcγ-receptor (FcγR) IIB is an absolute requirement for in vivo antitumor activity of agonistic mouse anti-CD40 monoclonal antibodies (mAbs), a similar requirement for human mAbs has been disputed. By using a mouse model humanized for its FcγRs and CD40, we revealed that FcγRIIB engagement is essential for the activity of human CD40 mAbs, while engagement of the activating FcγRIIA inhibits this activity. By engineering Fc variants with selective enhanced binding to FcγRIIB, but not to FcγRIIA, significantly improved antitumor immunity was observed. These findings highlight the necessity of optimizing the Fc domain for this class of therapeutic antibodies by using appropriate preclinical models that accurately reflect the unique affinities and cellular expression of human FcγR. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The transcriptional profiling of human in vivo-generated plasma cells identifies selective imbalances in monoclonal gammopathies.

    Directory of Open Access Journals (Sweden)

    Luis M Valor

    Full Text Available Plasma cells (PC represent the heterogeneous final stage of the B cells (BC differentiation process. To characterize the transition of BC into PC, transcriptomes from human naïve BC were compared to those of three functionally-different subsets of human in vivo-generated PC: i tonsil PC, mainly consisting of early PC; ii PC released to the blood after a potent booster-immunization (mostly cycling plasmablasts; and, iii bone marrow CD138+ PC that represent highly mature PC and include the long-lived PC compartment. This transcriptional transition involves subsets of genes related to key processes for PC maturation: the already known protein processing, apoptosis and homeostasis, and of new discovery including histones, macromolecule assembly, zinc-finger transcription factors and neuromodulation. This human PC signature is partially reproduced in vitro and is conserved in mouse. Moreover, the present study identifies genes that define PC subtypes (e.g., proliferation-associated genes for circulating PC and transcriptional-related genes for tonsil and bone marrow PC and proposes some putative transcriptional regulators of the human PC signatures (e.g., OCT/POU, XBP1/CREB, E2F, among others. Finally, we also identified a restricted imbalance of the present PC transcriptional program in monoclonal gammopathies that correlated with PC malignancy.

  8. Crystal structure of the Hendra virus attachment G glycoprotein bound to a potent cross-reactive neutralizing human monoclonal antibody.

    Directory of Open Access Journals (Sweden)

    Kai Xu

    Full Text Available The henipaviruses, represented by Hendra (HeV and Nipah (NiV viruses are highly pathogenic zoonotic paramyxoviruses with uniquely broad host tropisms responsible for repeated outbreaks in Australia, Southeast Asia, India and Bangladesh. The high morbidity and mortality rates associated with infection and lack of licensed antiviral therapies make the henipaviruses a potential biological threat to humans and livestock. Henipavirus entry is initiated by the attachment of the G envelope glycoprotein to host cell membrane receptors. Previously, henipavirus-neutralizing human monoclonal antibodies (hmAb have been isolated using the HeV-G glycoprotein and a human naïve antibody library. One cross-reactive and receptor-blocking hmAb (m102.4 was recently demonstrated to be an effective post-exposure therapy in two animal models of NiV and HeV infection, has been used in several people on a compassionate use basis, and is currently in development for use in humans. Here, we report the crystal structure of the complex of HeV-G with m102.3, an m102.4 derivative, and describe NiV and HeV escape mutants. This structure provides detailed insight into the mechanism of HeV and NiV neutralization by m102.4, and serves as a blueprint for further optimization of m102.4 as a therapeutic agent and for the development of entry inhibitors and vaccines.

  9. Crystal structure of the Hendra virus attachment G glycoprotein bound to a potent cross-reactive neutralizing human monoclonal antibody.

    Science.gov (United States)

    Xu, Kai; Rockx, Barry; Xie, Yihu; DeBuysscher, Blair L; Fusco, Deborah L; Zhu, Zhongyu; Chan, Yee-Peng; Xu, Yan; Luu, Truong; Cer, Regina Z; Feldmann, Heinz; Mokashi, Vishwesh; Dimitrov, Dimiter S; Bishop-Lilly, Kimberly A; Broder, Christopher C; Nikolov, Dimitar B

    2013-01-01

    The henipaviruses, represented by Hendra (HeV) and Nipah (NiV) viruses are highly pathogenic zoonotic paramyxoviruses with uniquely broad host tropisms responsible for repeated outbreaks in Australia, Southeast Asia, India and Bangladesh. The high morbidity and mortality rates associated with infection and lack of licensed antiviral therapies make the henipaviruses a potential biological threat to humans and livestock. Henipavirus entry is initiated by the attachment of the G envelope glycoprotein to host cell membrane receptors. Previously, henipavirus-neutralizing human monoclonal antibodies (hmAb) have been isolated using the HeV-G glycoprotein and a human naïve antibody library. One cross-reactive and receptor-blocking hmAb (m102.4) was recently demonstrated to be an effective post-exposure therapy in two animal models of NiV and HeV infection, has been used in several people on a compassionate use basis, and is currently in development for use in humans. Here, we report the crystal structure of the complex of HeV-G with m102.3, an m102.4 derivative, and describe NiV and HeV escape mutants. This structure provides detailed insight into the mechanism of HeV and NiV neutralization by m102.4, and serves as a blueprint for further optimization of m102.4 as a therapeutic agent and for the development of entry inhibitors and vaccines.

  10. Prophylactic and therapeutic testing of Nicotiana-derived RSV-neutralizing human monoclonal antibodies in the cotton rat model.

    Science.gov (United States)

    Zeitlin, Larry; Bohorov, Ognian; Bohorova, Natasha; Hiatt, Andrew; Kim, Do H; Pauly, Michael H; Velasco, Jesus; Whaley, Kevin J; Barnard, Dale L; Bates, John T; Crowe, James E; Piedra, Pedro A; Gilbert, Brian E

    2013-01-01

    Severe lower respiratory tract infection in infants and small children is commonly caused by respiratory syncytial virus (RSV). Palivizumab (Synagis(®)), a humanized IgG1 monoclonal antibody (mAb) approved for RSV immunoprophylaxis in at-risk neonates, is highly effective, but pharmacoeconomic analyses suggest its use may not be cost-effective. Previously described potent RSV neutralizers (human Fab R19 and F2-5; human IgG RF-1 and RF-2) were produced in IgG format in a rapid and inexpensive Nicotiana-based manufacturing system for comparison with palivizumab. Both plant-derived (palivizumab-N) and commercial palivizumab, which is produced in a mouse myeloma cell line, showed protection in prophylactic (p plant-derived human mAbs directed against alternative epitopes displayed neutralizing activity, but conferred less protection in vivo than palivizumab-N or palivizumab. Palivizumab remains one of the most efficacious RSV mAbs described to date. Production in plants may reduce manufacturing costs and improve the pharmacoeconomics of RSV immunoprophylaxis and therapy.

  11. Splenic embolization in a Jehovah's Witness: role of recombinant human factor VIIa.

    Science.gov (United States)

    Mindikoglu, Ayse L; Anantharaju, Abhinandana; George, Magdalene; Leone, Nancy; Bejna, Judy; Van Thiel, David H

    2003-01-01

    A case of a 50-year-old Jehovah's Witness with cryptogenic cirrhosis, severe portal hypertension and a coagulopathy, who underwent splenic embolization to improve the platelet count after receiving recombinant human Factor VIIa, is reported. Following the infusion of recombinant human Factor VIIa, the coagulopathy was rapidly corrected and it became possible to safely embolize her spleen. The changes in prothrombin time, international normalized ratio and activated partial thromboplastin time as well as thrombomodulin, tissue factor and plasminogen activator inhibitor after the infusion are presented. As a result of the splenic embolization, her platelet count normalized and she has been listed for liver transplantation.

  12. Conjugation of gold nanoparticles and recombinant human endostatin modulates vascular normalization via interruption of anterior gradient 2-mediated angiogenesis.

    Science.gov (United States)

    Pan, Fan; Yang, Wende; Li, Wei; Yang, Xiao-Yan; Liu, Shuhao; Li, Xin; Zhao, Xiaoxu; Ding, Hui; Qin, Li; Pan, Yunlong

    2017-07-01

    Several studies have revealed the potential of normalizing tumor vessels in anti-angiogenic treatment. Recombinant human endostatin is an anti-angiogenic agent which has been applied in clinical tumor treatment. Our previous research indicated that gold nanoparticles could be a nanoparticle carrier for recombinant human endostatin delivery. The recombinant human endostatin-gold nanoparticle conjugates normalized vessels, which improved chemotherapy. However, the mechanism of recombinant human endostatin-gold nanoparticle-induced vascular normalization has not been explored. Anterior gradient 2 has been reported to be over-expressed in many malignant tumors and involved in tumor angiogenesis. To date, the precise efficacy of recombinant human endostatin-gold nanoparticles on anterior gradient 2-mediated angiogenesis or anterior gradient 2-related signaling cohort remained unknown. In this study, we aimed to explore whether recombinant human endostatin-gold nanoparticles could normalize vessels in metastatic colorectal cancer xenografts, and we further elucidated whether recombinant human endostatin-gold nanoparticles could interrupt anterior gradient 2-induced angiogenesis. In vivo, it was indicated that recombinant human endostatin-gold nanoparticles increased pericyte expression while inhibit vascular endothelial growth factor receptor 2 and anterior gradient 2 expression in metastatic colorectal cancer xenografts. In vitro, we uncovered that recombinant human endostatin-gold nanoparticles reduced cell migration and tube formation induced by anterior gradient 2 in human umbilical vein endothelial cells. Treatment with recombinant human endostatin-gold nanoparticles attenuated anterior gradient 2-mediated activation of MMP2, cMyc, VE-cadherin, phosphorylation of p38, and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in human umbilical vein endothelial cells. Our findings demonstrated recombinant human endostatin-gold nanoparticles might normalize

  13. Characterization of Bioactive Recombinant Human Lysozyme Expressed in Milk of Cloned Transgenic Cattle

    Science.gov (United States)

    Yang, Bin; Wang, Jianwu; Tang, Bo; Liu, Yufang; Guo, Chengdong; Yang, Penghua; Yu, Tian; Li, Rong; Zhao, Jianmin; Zhang, Lei; Dai, Yunping; Li, Ning

    2011-01-01

    Background There is great potential for using transgenic technology to improve the quality of cow milk and to produce biopharmaceuticals within the mammary gland. Lysozyme, a bactericidal protein that protects human infants from microbial infections, is highly expressed in human milk but is found in only trace amounts in cow milk. Methodology/Principal Findings We have produced 17 healthy cloned cattle expressing recombinant human lysozyme using somatic cell nuclear transfer. In this study, we just focus on four transgenic cattle which were natural lactation. The expression level of the recombinant lysozyme was up to 25.96 mg/L, as measured by radioimmunoassay. Purified recombinant human lysozyme showed the same physicochemical properties, such as molecular mass and bacterial lysis, as its natural counterpart. Moreover, both recombinant and natural lysozyme had similar conditions for reactivity as well as for pH and temperature stability during in vitro simulations. The gross composition of transgenic and non-transgenic milk, including levels of lactose, total protein, total fat, and total solids were not found significant differences. Conclusions/Significance Thus, our study not only describes transgenic cattle whose milk offers the similar nutritional benefits as human milk but also reports techniques that could be further refined for production of active human lysozyme on a large scale. PMID:21436886

  14. Characterization of bioactive recombinant human lysozyme expressed in milk of cloned transgenic cattle.

    Directory of Open Access Journals (Sweden)

    Bin Yang

    Full Text Available BACKGROUND: There is great potential for using transgenic technology to improve the quality of cow milk and to produce biopharmaceuticals within the mammary gland. Lysozyme, a bactericidal protein that protects human infants from microbial infections, is highly expressed in human milk but is found in only trace amounts in cow milk. METHODOLOGY/PRINCIPAL FINDINGS: We have produced 17 healthy cloned cattle expressing recombinant human lysozyme using somatic cell nuclear transfer. In this study, we just focus on four transgenic cattle which were natural lactation. The expression level of the recombinant lysozyme was up to 25.96 mg/L, as measured by radioimmunoassay. Purified recombinant human lysozyme showed the same physicochemical properties, such as molecular mass and bacterial lysis, as its natural counterpart. Moreover, both recombinant and natural lysozyme had similar conditions for reactivity as well as for pH and temperature stability during in vitro simulations. The gross composition of transgenic and non-transgenic milk, including levels of lactose, total protein, total fat, and total solids were not found significant differences. CONCLUSIONS/SIGNIFICANCE: Thus, our study not only describes transgenic cattle whose milk offers the similar nutritional benefits as human milk but also reports techniques that could be further refined for production of active human lysozyme on a large scale.

  15. Monoclonal antibody to human cartilage cells and its reactivities to chondrocytic tumors.

    Science.gov (United States)

    Eisenbrey, A B; Chen, J C; Dyer, C A; Bernstein, J; Poulik, M D

    1991-01-01

    A murine monoclonal antibody (E10) was made against cultured cartilage cells. The E10 antibody binding is localized to the surface of cultured cartilage cells in suspension and is present in the cytoplasm in paraffin embedded sections. There is no reactivity with cartilage matrix, or with the matrix of cartilaginous tumors. Reactivity is removed by treatment with trypsin and hyaluronidase, but not by treatment with heparinase, neuraminidase, and chondroitinase. Regeneration of E10 antigen after trypsinization takes 48 hours in chondrocytes in tissue culture. SDS-polyacrylamide gel electrophoresis of an E10 immune precipitate of cultured chondrocytes results in two peaks: one at a very high molecular weight and a small fragment at approximately 250 kd. Specificity has been demonstrated by cytofluorometry, immunofluorescence, and immunohistochemistry, in both frozen and paraffin-embedded tissues. Positive reactivity was seen in cultured cartilage cells, chondrocytes in fetal and adult cartilage, chondrosarcomas, and chordomas. Minimal reactivity was found in a chondromyxoid liposarcoma. Acinar cells of salivary and sweat glands and mast cells in various tissues and tumors were also positive. There was no reactivity with other tissues and tumors, including myxoid and mucinous tumors and epithelial tissues.

  16. Broadly neutralizing human monoclonal JC polyomavirus VP1–specific antibodies as candidate therapeutics for progressive multifocal leukoencephalopathy

    Science.gov (United States)

    Jelcic, Ivan; Combaluzier, Benoit; Jelcic, Ilijas; Faigle, Wolfgang; Senn, Luzia; Reinhart, Brenda J.; Ströh, Luisa; Nitsch, Roger M.; Stehle, Thilo; Sospedra, Mireia; Grimm, Jan; Martin, Roland

    2016-01-01

    In immunocompromised individuals, JC polyomavirus (JCPyV) may mutate and gain access to the central nervous system resulting in progressive multifocal leukoencephalopathy (PML), an often fatal opportunistic infection for which no treatments are currently available. Despite recent progress, the contribution of JCPyV-specific humoral immunity to controlling asymptomatic infection throughout life and to eliminating JCPyV from the brain is poorly understood. We examined antibody responses against JCPyV major capsid protein VP1 (viral protein 1) variants in the serum and cerebrospinal fluid (CSF) of healthy donors (HDs), JCPyV-positive multiple sclerosis patients treated with the anti-VLA-4 monoclonal antibody natalizumab (NAT), and patients with NAT-associated PML. Before and during PML, CSF antibody responses against JCPyV VP1 variants show “recognition holes”; however, upon immune reconstitution, CSF antibody titers rise, then recognize PML-associated JCPyV VP1 variants, and may be involved in elimination of the virus. We therefore reasoned that the memory B cell repertoire of individuals who recovered from PML could be a source for the molecular cloning of broadly neutralizing antibodies for passive immunization. We generated a series of memory B cell-derived JCPyV VP1-specific human monoclonal antibodies from HDs and a patient with NAT-associated PML-immune reconstitution inflammatory syndrome (IRIS). These antibodies exhibited diverse binding affinity, cross-reactivity with the closely related BK polyomavirus, recognition of PML-causing VP1 variants, and JCPyV neutralization. Almost all antibodies with exquisite specificity for JCPyV, neutralizing activity, recognition of all tested JCPyV PML variants, and high affinity were derived from one patient who had recovered from PML. These antibodies are promising drug candidates for the development of a treatment of PML. PMID:26400911

  17. Establishing in vitro in vivo correlations to screen monoclonal antibodies for physicochemical properties related to favorable human pharmacokinetics.

    Science.gov (United States)

    Avery, Lindsay B; Wade, Jason; Wang, Mengmeng; Tam, Amy; King, Amy; Piche-Nicholas, Nicole; Kavosi, Mania S; Penn, Steve; Cirelli, David; Kurz, Jeffrey C; Zhang, Minlei; Cunningham, Orla; Jones, Rhys; Fennell, Brian J; McDonnell, Barry; Sakorafas, Paul; Apgar, James; Finlay, William J; Lin, Laura; Bloom, Laird; O'Hara, Denise M

    2017-12-22

    Implementation of in vitro assays that correlate with in vivo human pharmacokinetics (PK) would provide desirable preclinical tools for the early selection of therapeutic monoclonal antibody (mAb) candidates with minimal non-target-related PK risk. Use of these tools minimizes the likelihood that mAbs with unfavorable PK would be advanced into costly preclinical and clinical development. In total, 42 mAbs varying in isotype and soluble versus membrane targets were tested in in vitro and in vivo studies. MAb physicochemical properties were assessed by measuring non-specific interactions (DNA- and insulin-binding ELISA), self-association (affinity-capture self-interaction nanoparticle spectroscopy) and binding to matrix-immobilized human FcRn (surface plasmon resonance and column chromatography). The range of scores obtained from each in vitro assay trended well with in vivo clearance (CL) using both human FcRn transgenic (Tg32) mouse allometrically projected human CL and observed human CL, where mAbs with high in vitro scores resulted in rapid CL in vivo. Establishing a threshold value for mAb CL in human of 0.32 mL/hr/kg enabled refinement of thresholds for each in vitro assay parameter, and using a combinatorial triage approach enabled the successful differentiation of mAbs at high risk for rapid CL (unfavorable PK) from those with low risk (favorable PK), which allowed mAbs requiring further characterization to be identified. Correlating in vitro parameters with in vivo human CL resulted in a set of in vitro tools for use in early testing that would enable selection of mAbs with the greatest likelihood of success in the clinic, allowing costly late-stage failures related to an inadequate exposure profile, toxicity or lack of efficacy to be avoided.

  18. Humanizing recombinant glycoproteins from Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Hansen, Anders Holmgaard; Amann, Thomas; Kol, Stefan

    hamster ovary (CHO) cells are making a very heterogeneous mixture of NGlycans. We speculate that the CHO pattern of N-Glycans would affect half-life and/or efficacy of the glycoprotein in the bloodstream making it unsuitable for human intravenous use, whereas our humanized version would be identical...

  19. Purification of recombinant C-terminus polyhistidine tagged human ...

    African Journals Online (AJOL)

    Human calcitonin (hCT) is a 32 amino acid peptide that participates in the regulation of calcium and phosphorus metabolism in human. It is used in clinics for the treatment of diseases related to bone decalcification, such as Paget disease, osteoporosis imperfecta and parathyroid gland carcinoma. In this research ...

  20. The 8p23 inversion polymorphism determines local recombination heterogeneity across human populations.

    Science.gov (United States)

    Alves, Joao M; Chikhi, Lounès; Amorim, António; Lopes, Alexandra M

    2014-04-01

    For decades, chromosomal inversions have been regarded as fascinating evolutionary elements as they are expected to suppress recombination between chromosomes with opposite orientations, leading to the accumulation of genetic differences between the two configurations over time. Here, making use of publicly available population genotype data for the largest polymorphic inversion in the human genome (8p23-inv), we assessed whether this inhibitory effect of inversion rearrangements led to significant differences in the recombination landscape of two homologous DNA segments, with opposite orientation. Our analysis revealed that the accumulation of genetic differentiation is positively correlated with the variation in recombination profiles. The observed recombination dissimilarity between inversion types is consistent across all populations analyzed and surpasses the effects of geographic structure, suggesting that both structures (orientations) have been evolving independently over an extended period of time, despite being subjected to the very same demographic history. Aside this mainly independent evolution, we also identified a short segment (350 kb, inversion) in the central region of the inversion where the genetic divergence between the two structural haplotypes is diminished. Although it is difficult to demonstrate it, this could be due to gene flow (possibly via double-crossing over events), which is consistent with the higher recombination rates surrounding this segment. This study demonstrates for the first time that chromosomal inversions influence the recombination landscape at a fine-scale and highlights the role of these rearrangements as drivers of genome evolution.

  1. A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words

    Energy Technology Data Exchange (ETDEWEB)

    Mirick, G. R.; Bradt, B. M.; Denardo, S. J.; Denardo, G. L. [Calfornia Univ., Sacramento (United States). Davis Medical Center

    2004-12-01

    The United States Food and Drugs Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ({sup 9}0yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ({sup 1}31I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) antiCD20 MAns for use in radioimmunotherapy (RIT) of non-Hodgikin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, essays were developed to determine HAGE (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to humanize MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades.

  2. Detection of HLA-G on human extravillous cytotrophoblast and skeletal muscle with a new monoclonal antibody MEM-G/1.

    Science.gov (United States)

    Lodererová, A; Honsová, E; Viklický, O

    2003-01-01

    Using immunohistochemistry with the newly available monoclonal antibody MEM-G/1 the reaction patterns on frozen and formaldehyde-fixed paraffin-embedded sections on human placentas, lymph nodes, skeletal muscles, and kidney and liver allografts were compared. HLA-G (a nonclassical major histocompatibility complex class I molecule that is assumed to influence the immune response during pregnancy and some pathological conditions) was found within human extravillous cytotrophoblast but not within villous cytotrophoblast and placental mesenchymal tissue. No HLA-G expression on human lymph nodes, tonsils, and kidney and liver allografts was demonstrated. However, HLA-G expression was observed in all samples of skeletal muscle. The binding capacity of monoclonal antibody MEM-G/1 provides new possibilities to study physiological and pathophysiological roles of HLA-G in humans.

  3. Recombinant human lactoferrin modulates human PBMC derived macrophage responses to BCG and LPS.

    Science.gov (United States)

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2016-12-01

    Lactoferrin, an iron-binding glycoprotein found in mammalian mucosal secretions and granules of neutrophils, possesses several immune modulatory properties. Published reports indicate that lactoferrin enhances the efficacy of the tuberculosis vaccine, BCG (Bacillus Calmette Guerin), both by increasing macrophage and dendritic cell ability to stimulate receptive T cells and by modulating the inflammatory response. This report is the first to demonstrate the effects of a recombinant human lactoferrin (10 μg/mL) on human PBMC derived CD14+ and CD16+ macrophages stimulated with a strong (LPS, 10 ng/mL) or weaker (BCG, MOI 1:1) stimulator of inflammation. After 3 days culture, LPS and human lactoferrin treated CD14+ cells significantly increased production of IL-10, IL-6, and MCP-1 compared to the LPS only group. In contrast, similarly treated CD16+ macrophages increased production of IL-12p40 and IL-10 and decreased TNF-α. Limited changes were observed in BCG stimulated CD14+ and CD16+ macrophages with and without lactoferrin. Analysis of surface expression of antigen presentation and co-stimulatory molecules demonstrated that CD14+ macrophages, when stimulated with BCG or LPS and cultured with lactoferrin, increased expression of CD86. CD16+ macrophages treated with lactoferrin showed a similar trend of increase in CD86 expression, but only when stimulated with BCG. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Genome-scale metabolic model of Pichia pastoris with native and humanized glycosylation of recombinant proteins

    DEFF Research Database (Denmark)

    Irani, Zahra Azimzadeh; Kerkhoven, Eduard J.; Shojaosadati, Seyed Abbas

    2016-01-01

    native nor humanized N-glycosylation, and we therefore developed ihGlycopastoris, an extension to the iLC915 model with both native and humanized N-glycosylation for recombinant protein production, but also an estimation of N-glycosylation of P. pastoris native proteins. This new model gives a better......Pichia pastoris is used for commercial production of human therapeutic proteins, and genome-scale models of P. pastoris metabolism have been generated in the past to study the metabolism and associated protein production by this yeast. A major challenge with clinical usage of recombinant proteins...... produced by P. pastoris is the difference in N-glycosylation of proteins produced by humans and this yeast. However, through metabolic engineering, a P. pastoris strain capable of producing humanized N-glycosylated proteins was constructed. The current genome-scale models of P. pastoris do not address...

  5. Structural Basis for Recognition of Human Enterovirus 71 by a Bivalent Broadly Neutralizing Monoclonal Antibody.

    Directory of Open Access Journals (Sweden)

    Xiaohua Ye

    2016-03-01

    Full Text Available Enterovirus 71 (EV71 is the main pathogen responsible for hand, foot and mouth disease with severe neurological complications and even death in young children. We have recently identified a highly potent anti-EV71 neutralizing monoclonal antibody, termed D5. Here we investigated the structural basis for recognition of EV71 by the antibody D5. Four three-dimensional structures of EV71 particles in complex with IgG or Fab of D5 were reconstructed by cryo-electron microscopy (cryo-EM single particle analysis all at subnanometer resolutions. The most critical EV71 mature virion-Fab structure was resolved to a resolution of 4.8 Å, which is rare in cryo-EM studies of virus-antibody complex so far. The structures reveal a bivalent binding pattern of D5 antibody across the icosahedral 2-fold axis on mature virion, suggesting that D5 binding may rigidify virions to prevent their conformational changes required for subsequent RNA release. Moreover, we also identified that the complementary determining region 3 (CDR3 of D5 heavy chain directly interacts with the extremely conserved VP1 GH-loop of EV71, which was validated by biochemical and virological assays. We further showed that D5 is indeed able to neutralize a variety of EV71 genotypes and strains. Moreover, D5 could potently confer protection in a mouse model of EV71 infection. Since the conserved VP1 GH-loop is involved in EV71 binding with its uncoating receptor, the scavenger receptor class B, member 2 (SCARB2, the broadly neutralizing ability of D5 might attribute to its inhibition of EV71 from binding SCARB2. Altogether, our results elucidate the structural basis for the binding and neutralization of EV71 by the broadly neutralizing antibody D5, thereby enhancing our understanding of antibody-based protection against EV71 infection.

  6. MINOR HUMAN-ANTIBODY RESPONSE TO A MOUSE AND CHIMERIC MONOCLONAL-ANTIBODY AFTER A SINGLE IV INFUSION IN OVARIAN-CARCINOMA PATIENTS - A COMPARISON OF 5 ASSAYS

    NARCIS (Netherlands)

    BUIST, MR; KENEMANS, P; VANKAMP, GJ; Haisma, Hidde

    The human anti-(mouse Ig) antibody (HAMA) response was measured in serum of 52 patients suspected of having ovarian carcinoma who had received an i.v. injection of either the murine monoclonal antibody (mAb) OV-TL 3 F(ab')(2) (n = 28, 1 mg) or the chimeric mouse/human mAb MOv18 (cMOv18; n = 24, 3

  7. Robotics for recombinant DNA and human genetics research

    Energy Technology Data Exchange (ETDEWEB)

    Beugelsdijk, T.J.

    1990-01-01

    In October of 1989, molecular biologists throughout the world formally embarked on ultimately determining the set of genetic instructions for a human being. Called by some the Manhattan Project'' a molecular biology, pursuit of this goal is projected to require approximately 3000 man years of effort over a 15-year period. The Humane Genome Initiative is a worldwide research effort that has the goal of analyzing the structure of human deoxyribonucleic acid (DNA) and determining the location of all human genes. The Department of Energy (DOE) has designated three of its national laboratories as centers for the Human Genome Project. These are Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), and Lawrence Berkeley Laboratory (LBL). These laboratories are currently working on different, but complementary technology development areas in support of the Human Genome Project. The robotics group at LANL is currently working at developing the technologies that address the problems associated with physical mapping. This article describes some of these problems and discusses some of the robotics approaches and engineering tolls applicable to their solution. 7 refs., 8 figs., 1 tab.

  8. Method and cell lines for the production of monoclonal antibodies to human glycophorin A

    Science.gov (United States)

    Bigbee, W.L.; Fong, S.S.N.; Jensen, R.H.; Vanderlaan, M.

    Cloned mouse hybridoma cell lines have been established which continuously produce antibodies that differentiate between the M and N forms of human glycophorin A. These antibodies have potential application as human blood group reagents, as markers for terminally differentiated erythroid cells and as immunofluorescent labels of somatically variant human erythrocytes.

  9. Application of Recombinant Proteins for Serodiagnosis of Visceral Leishmaniasis in Humans and Dogs.

    Science.gov (United States)

    Farahmand, Mahin; Nahrevanian, Hossein

    2016-07-01

    Visceral leishmaniasis (VL) is a zoonotic disease caused by leishmania species. Dogs are considered to be the main reservoir of VL. A number of methods and antigen-based assays are used for the diagnosis of leishmaniasis. However, currently available methods are mainly based on direct examination of tissues for the presence of parasites, which is highly invasive. A variety of serological tests are commonly applied for VL diagnosis, including indirect fluorescence antibody test, enzyme-linked immunosorbent assay (ELISA), dot-ELISA, direct agglutination test, Western-blotting, and immunochromatographic test. However, when soluble antigens are used, serological tests are less specific due to cross-reactivity with other parasitic diseases. Several studies have attempted to replace soluble antigens with recombinant proteins to improve the sensitivity and the specificity of the immunodiagnostic tests. Major technological advances in recombinant antigens as reagents for the serological diagnosis of VL have led to high sensitivity and specificity of these serological tests. A great number of recombinant proteins have been shown to be effective for the diagnosis of leishmania infection in dogs, the major reservoir of L. infantum. Although few recombinant proteins with high efficacy provide reasonable results for the diagnosis of human and canine VL, more optimization is still needed for the appropriate antigens to provide high-throughput performance. This review aims to explore the application of different recombinant proteins for the serodiagnosis of VL in humans and dogs.

  10. Further phenotypic characterization and isolation of human hematopoietic progenitor cells using a monoclonal antibody to the c-kit receptor.

    Science.gov (United States)

    Briddell, R A; Broudy, V C; Bruno, E; Brandt, J E; Srour, E F; Hoffman, R

    1992-06-15

    A mouse antihuman monoclonal IgG2a antibody, termed stem cell receptor-1 (SR-1), specific for a determinant of the c-kit ligand receptor (KR), was used as an immunologic probe to analyze KR expression by human bone marrow hematopoietic progenitor cells. Monoclonal antibodies to CD34 and HLA-DR were used in a multicolor staining protocol in conjunction with SR-1 to further define the phenotypes of various classes of hematopoietic progenitor cells. Expression of KR (SR-1+) on hematopoietic progenitor cells identified subpopulations of cells expressing CD34 (CD34+). While one-half of the CD34- and HLA-DR-expressing cells (CD34+ HLA-DR+) expressed the KR (SR-1+), one-third of the CD34+ cells that lacked HLA-DR expression (CD34+ HLA-DR-) were SR-1+. The CD34+ HLA-DR+ SR-1+ cell population contained the vast majority of the more differentiated progenitor cells, including the colony-forming unit (CFU) granulocyte-macrophage; burst-forming unit-erythrocyte; CFU-granulocyte, erythrocyte, macrophage, megakaryocyte; and the CFU-megakaryocyte. The overall progenitor cell cloning efficiency of this subpopulation was greater than 31%. By contrast, the CD34+ HLA-DR- SR-1+ cell population contained fewer of these more differentiated progenitor cells but exclusively contained the more primitive progenitor cells, the BFU-megakaryocyte, high proliferative potential-colony-forming cell, and long-term bone marrow culture-initiating cell. The overall progenitor cell cloning efficiency of this subpopulation was greater than 7%. Both the CD34+ HLA-DR- and CD34+ HLA-DR+ cell subpopulations lacking KR expression contained few assayable hematopoietic progenitor cells. Long-term bone marrow cultures initiated with CD34+ HLA-DR- SR-1+ but not CD34+ HLA-DR- SR-1- cells, which were repeatedly supplemented with c-kit ligand (KL) and interleukin-3, generated assayable progenitor cells of at least 2 lineages for 10 weeks. These experiments demonstrate the expression of the KR throughout the

  11. Structural Evolution of Human Recombinant alfaB-Crystallin under UV Irradiation

    DEFF Research Database (Denmark)

    Sugiyama, Masaaki; Fujii, Noriko; Morimoto, Yukio

    2008-01-01

    External stresses cause certain proteins to lose their regular structure and aggregate. In order to clarify this abnormal aggregation process, a structural evolution of human recombinant aB-crystallin under UV irradiation was observed with in situ small-angle neutron scattering. The abnormal...

  12. How bio-questionable are the different recombinant human erythropoietin copy products in Thailand?

    NARCIS (Netherlands)

    Halim, Liem Andhyk|info:eu-repo/dai/nl/412608294; Brinks, Vera|info:eu-repo/dai/nl/31395979X; Jiskoot, Wim; Romeijn, Stefan; Praditpornsilpa, Kearkiat; Assawamakin, Anunchai; Schellekens, Huub|info:eu-repo/dai/nl/068406762

    2014-01-01

    PURPOSE: The high prevalence of pure red cell aplasia in Thailand has been associated with the sharp increase in number of recombinant human erythropoietin (rhEPO) copy products, based on a classical generic regulatory pathway, which have entered the market. This study aims to assess the quality of

  13. New insights for identification of doping with recombinant human erythropoietin micro-doses after high hydration

    DEFF Research Database (Denmark)

    Martin, L.; Ashenden, M; Bejder, Jacob

    2016-01-01

    To minimize the chances of being caught after doping with recombinant human erythropoietins (rhEPO), athletes have turned to new practices using micro-doses and excess fluid ingestion to accelerate elimination and decrease the probability of detection. Our objective was to test the sensitivity of...

  14. Modification of human beta-globin locus PAC clones by homologous recombination in Escherichia coli

    NARCIS (Netherlands)

    G.P. Patrinos (George); M. de Krom (Mariken); S. Bottardi; R.J. Janssens; E. Katsantoni (Eleni); A.W. Wai; D.J. Sherratt; F.G. Grosveld (Frank); A.M.A. Imam (Ali)

    2000-01-01

    textabstractWe report here modifications of human beta-globin PAC clones by homologous recombination in Escherichia coli DH10B, utilising a plasmid temperature sensitive for replication, the recA gene and a wild-type copy of the rpsL gene which allows for an efficient selection for

  15. Bioconversion of Mono- and Sesquiterpenoids by Recombinant Human Cytochrome P450 Monooxygenases

    NARCIS (Netherlands)

    Julsing, Mattijs K.; Fichera, Mario A.; Malz, Frank; Ebbelaar, Monique; Bos, Rein; Woerdenbag, Herman J.; Quax, Wim J.; Kayser, Oliver

    2008-01-01

    Cytochrome P450 monooxygenases play an important role in the biosynthesis and metabolism of terpenoids. We explored the potential of recombinant human liver cytochrome P450 monooxygenases CYP1A2, CYP2C9, and CYP3A4, heterologously expressed in Escherichia coli, to convert mono- and sesquiterpenoids

  16. Biodistribution and translational pharmacokinetic modeling of a human recombinant alkaline phosphatase

    NARCIS (Netherlands)

    Peters, Esther; Stevens, Jasper; Arend, Jacques; Guan, Zheng; Raaben, Willem; Laverman, Peter; Elsas, Andrea van; Masereeuw, R.; Pickkers, Peter

    2015-01-01

    Clinical trials showed renal protective effects of bovine intestinal alkaline phosphatase (AP) in patients with sepsis-associated Acute Kidney Injury (AKI). Subsequently, a human recombinant chimeric AP (recAP) was developed as a pharmaceutically acceptable alternative. Here, we investigated the

  17. Prevention of murine experimental autoimmune orchitis by recombinant human interleukin-6

    DEFF Research Database (Denmark)

    Li, Lu; Itoh, Masahiro; Ablake, Maila

    2002-01-01

    We studied the effect of exogenously administered recombinant human interleukin (IL)-6 on the development of experimental autoimmune orchitis (EAO) in C3H/Hej mice. IL-6 significantly reduced histological signs of EAO and appearance of delayed type hypersensitivity against the immunizing testicul...

  18. Recombinant human DNase nebulisation in children with cystic fibrosis: Before bedtime or after waking up?

    NARCIS (Netherlands)

    L.J. van der Giessen (Lianne); R.A.A.M. Gosselink (Rik); W.C.J. Hop (Wim); H.A.W.M. Tiddens (Harm)

    2007-01-01

    textabstractThe present study focused on patients with cystic fibrosis (CF), who were on maintenance therapy with recombinant human deoxyribonuclease (rhDNase), with the aim of comparing efficacy and possible side effects of nebulisation of rhDNase when taken before bedtime with efficacy and side

  19. Human recombinant protein C for severe sepsis and septic shock in adult and paediatric patients

    DEFF Research Database (Denmark)

    Martí-Carvajal, Arturo J; Solà, Ivan; Gluud, Christian

    2012-01-01

    Sepsis is a common and frequently fatal condition. Human recombinant activated protein C (APC) has been introduced to reduce the high risk of death associated with severe sepsis or septic shock. This systematic review is an update of a Cochrane review originally published in 2007....

  20. Prevention of murine experimental autoimmune orchitis by recombinant human interleukin-6

    DEFF Research Database (Denmark)

    Li, Lu; Itoh, Masahiro; Ablake, Maila

    2002-01-01

    We studied the effect of exogenously administered recombinant human interleukin (IL)-6 on the development of experimental autoimmune orchitis (EAO) in C3H/Hej mice. IL-6 significantly reduced histological signs of EAO and appearance of delayed type hypersensitivity against the immunizing testicular...

  1. Formulation and process development of (recombinant human) deoxyribonuclease I as a powder for inhalation

    NARCIS (Netherlands)

    Zijlstra, Gerrit S; Ponsioen, Bart J; Hummel, Sylvia A; Sanders, Niek; Hinrichs, Wouter L J; de Boer, Anne H; Frijlink, Henderik W

    2009-01-01

    A formulation and process development study was performed to formulate recombinant human deoxyribonuclease I as a powder for inhalation. First, excipient compatibility (with bovine DNase as a model substance) was examined with a stability study at stressed conditions (60 and 85 degrees C) while

  2. Recombinant human erythropoietin and hemoglobin concentration at operation and during the postoperative period

    DEFF Research Database (Denmark)

    Qvist, N; Boesby, S; Wolff, B

    1999-01-01

    In a double-blind placebo-controlled study we investigated the effect of recombinant human erythropoietin (r-HuEPO), on the perioperative hemoglobin concentration and the use of blood transfusions in patients undergoing elective colorectal surgery with a preoperative hemoglobin level

  3. Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology.

    Science.gov (United States)

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2017-02-01

    Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.

  4. High prevalence of human anti-bovine IgG antibodies as the major cause of false positive reactions in two-site immunoassays based on monoclonal antibodies

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Koch, Claus; Jensen, Charlotte H

    2004-01-01

    A sandwich ELISA for quantification of the endometrial protein PP14 revealed false positive reactions in 81% of male sera (n = 54). The PP14 ELISA was based on two monoclonal antibodies (Mabs) with different epitope specificities--a catcher and a biotinylated indicator. The monoclonal antibodies...... were purified by protein G affinity chromatography from culture supernatant containing 10% (v/v) fetal calf serum (FCS). Human anti-animal IgG (bovine, mouse, horse, and swine) antibodies and human anti-bovine serum albumin antibodies were measured using an ELISA design, with direct bridging...... of the solid phase and biotinylated antigens. The false positive reactions were abolished by addition of 1% (v/v) bovine serum to the dilution buffer (DB). Human anti-bovine IgG antibodies (HABIA) were detected in 99 out of 104 sera from blood donors (50 females; 54 males). HABIA levels in male sera (n = 54...

  5. Laboratory scale production of the human recombinant iduronate 2 ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-04

    May 4, 2009 ... with glycine 1.7 mM). The fluorescence was determined in a fluorometer Turner 450, with wave lengths of excitation and emission of 360 and 415 nm, respectively. The control was leukocytes or human plasma (Voznyi et al., 2001). Enzyme activity was expressed as nmol of substrate converted h-1 mg-1 of ...

  6. Recombinant production of the human complement factor 5a in ...

    African Journals Online (AJOL)

    Up to now, the human complement factor 5a (C5a) has only been produced in small quantities in Escherichia coli in a soluble, bioactive conformation, which is not suitable for commercial production systems. This stems from the extremely high instability of C5a, as well as its aggregation-prone nature. Therefore, we ...

  7. Production and characterisation of recombinant forms of human pulmonary surfactant protein C (SP-C)

    DEFF Research Database (Denmark)

    Lukovic, Dunja; Plasencia, Inés; Taberner, Francisco J

    2006-01-01

    -C-derived peptides or recombinant humanized SP-C for inclusion in new preparations for therapeutic use. We describe herein the recombinant production in bacterial cultures of SP-C variants containing phenylalanines instead of the palmitoylated cysteines of the native protein, as fusions to the hydrophilic nuclease...... A (SN) from Staphylococcus aureus. The resulting chimerae were partially purified by affinity chromatography and subsequently subjected to protease digestion. The SP-C forms were recovered from the digestion mixtures by organic extraction and further purified by size exclusion chromatography. The two...

  8. High-level secretion of native recombinant human calreticulin in yeast

    DEFF Research Database (Denmark)

    Čiplys, Evaldas; Žitkus, Eimantas; Gold, Leslie I.

    2015-01-01

    , Saccharomyces cerevisiae and Pichia pastoris. RESULTS: Expression of a full-length human CRT precursor including its native signal sequence resulted in high-level secretion of mature recombinant protein into the culture medium by both S. cerevisiae and P. pastoris. To ensure the structural and functional...... recombinant CRT protein with yields reaching 75 % of total secreted protein and with production levels of 60 and 200 mg/l from S. cerevisiae and P. pastoris, respectively. Finally, cultivation of P. pastoris in a bioreactor yielded CRT secretion titer to exceed 1.5 g/l of culture medium. CONCLUSIONS: Yeasts...

  9. Long-term intravenous treatment of Pompe disease with recombinant human alpha-glucosidase from milk

    OpenAIRE

    Hout, Johanna; Sibbles, Barbara; Brakenhoff, Just; Cromme-Dijkhuis, Adri; Weisglas-Kuperus, Nynke; Reuser, Arnold; Boer, Marijke; Smeitink, Jan; Diggelen, Otto; Voort, Edwin; Corven, Emiel; Hirtum, Hans; Kamphoven, Joep; Ploeg, Ans; Hove, Johan

    2004-01-01

    OBJECTIVE: Recent reports warn that the worldwide cell culture capacity is insufficient to fulfill the increasing demand for human protein drugs. Production in milk of transgenic animals is an attractive alternative. Kilogram quantities of product per year can be obtained at relatively low costs, even in small animals such as rabbits. We tested the long-term safety and efficacy of recombinant human -glucosidase (rhAGLU) from rabbit milk for the treatment of the lysosomal storage disorder Pomp...

  10. Recombinant human butyrylcholinesterase from milk of transgenic animals to protect against organophosphate poisoning

    OpenAIRE

    Huang, Yue-Jin; Huang, Yue; Baldassarre, Hernan; Wang, Bin; Lazaris, Anthoula; Leduc, Martin; Bilodeau, Annie S; Bellemare, Annie; Côté, Mélanie; Herskovits, Peter; Touati, Madjid; Turcotte, Carl; Valeanu, Loredana; Lemée, Nicolas; Wilgus, Harvey

    2007-01-01

    Dangerous organophosphorus (OP) compounds have been used as insecticides in agriculture and in chemical warfare. Because exposure to OP could create a danger for humans in the future, butyrylcholinesterase (BChE) has been developed for prophylaxis to these chemicals. Because it is impractical to obtain sufficient quantities of plasma BChE to treat humans exposed to OP agents, the production of recombinant BChE (rBChE) in milk of transgenic animals was investigated. Transgenic mice and goats w...

  11. Frequency and genetic characterization of V(DD)J recombinants in the human peripheral blood antibody repertoire.

    Science.gov (United States)

    Briney, Bryan S; Willis, Jordan R; Hicar, Mark D; Thomas, James W; Crowe, James E

    2012-09-01

    Antibody heavy-chain recombination that results in the incorporation of multiple diversity (D) genes, although uncommon, contributes substantially to the diversity of the human antibody repertoire. Such recombination allows the generation of heavy chain complementarity determining region 3 (HCDR3) regions of extreme length and enables junctional regions that, because of the nucleotide bias of N-addition regions, are difficult to produce through normal V(D)J recombination. Although this non-classical recombination process has been observed infrequently, comprehensive analysis of the frequency and genetic characteristics of such events in the human peripheral blood antibody repertoire has not been possible because of the rarity of such recombinants and the limitations of traditional sequencing technologies. Here, through the use of high-throughput sequencing of the normal human peripheral blood antibody repertoire, we analysed the frequency and genetic characteristics of V(DD)J recombinants. We found that these recombinations were present in approximately 1 in 800 circulating B cells, and that the frequency was severely reduced in memory cell subsets. We also found that V(DD)J recombination can occur across the spectrum of diversity genes, indicating that virtually all recombination signal sequences that flank diversity genes are amenable to V(DD)J recombination. Finally, we observed a repertoire bias in the diversity gene repertoire at the upstream (5') position, and discovered that this bias was primarily attributable to the order of diversity genes in the genomic locus. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

  12. Expression of Recombinant Streptokinase from Streptococcus Pyogenes and Its Reaction with Infected Human and Murine Sera

    Directory of Open Access Journals (Sweden)

    Neda Molaee

    2013-09-01

    Full Text Available   Objective(s: Streptokinase (SKa is an antigenic protein which is secreted by Streptococcus pyogenes. Streptokinase induces inflammation by complement activation, which may play a role in post infectious diseases. In the present study, recombinant streptokinase from S. pyogenes was produced and showed that recombinant SKa protein was recognized by infected human sera using Western blot analysis.   Materials and Methods: In this study, the ska gene from S. pyogenes was amplified and cloned into pET32a which is a prokaryotic expression vector. pET32a-ska was transformed to Escherichia coli BL21 (DE3 pLysS and gene expression was induced by IPTG. Protein production was improved by modification of composition of the bacterial culture media and altering the induction time by IPTG. The expressed protein was purified by affinity chromatography using the Ni-NTA resin. The integrity of the product was confirmed by Westernblot analysis using infected mice. Serum reactivity of five infected individuals was further analyzed against the recombinant SKa protein. Results: Data indicated that recombinant SKa protein from S. pyogenes can be recognized by patient and mice sera. The concentration of the purified recombinant protein was 3.2 mg/L of initial culture. The highest amount of the expressed protein after addition of IPTG was obtained in a bacterial culture without glucose with the culture optical density of 0.8 (OD600 = 0.8. Conclusion : Present data shows, recombinant SKa protein has same epitopes with natural form of this antigen. Recombinant SKa also seemed to be a promising antigen for the serologic diagnosis of S. pyogenes infections.

  13. Properties of recombinant human plasma procarboxypeptidase U produced in mammalian and insect cells.

    Science.gov (United States)

    Strömqvist, Mats; Hansson, Lennart; Andersson, Jan-Olof; Johansson, Thord; Edlund, Michael; Enoksson, Maria; Goossens, Filip; Scharpé, Simon; Hendriks, Dirk

    2004-09-01

    Carboxypeptidase U (EC 3.4.17.20, TAFIa) is a new member of the metallocarboxypeptidase family circulating in human plasma as a zymogen. It is activated during coagulation and is considered as an important player in the regulation of fibrinolysis. Heterologous expression of human plasma procarboxypeptidase U (proCPU, TAFI) was obtained in mammalian cells (C127 and DON) and in insect cells (Sf21 and H5 cells). Conditioned media were purified by cation-exchange chromatography and plasminogen affinity chromatography to yield an essentially pure protein. All systems gave high expression levels (6-20 mg/l). Due to differences in glycosylation of the activation peptide, the recombinant variants of proCPU migrated differently on SDS-PAGE (52-65 kDa). However, after activation, all active recombinant enzymes migrated at 35 kDa, similar to native CPU and no evidence for post-translational modification of the catalytic domains could be detected. For the mammalian cell produced variants, activation was more efficient after desialylation. After activation, CPU showed low solubility (0.2 mg/ml) but was inhibited similarly as native CPU. Mammalian cell systems were the most efficient for the production of human plasma recombinant proCPU. The obtained zymogen differs with respect to the extent and the heterogeneity of glycosylation but, after activation, the experiments did not reveal any alteration between the recombinant and native protein.

  14. Recombinant production of human Aquaporin-1 to an exceptional high membrane density in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Julie Bomholt

    Full Text Available In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tagged with yeast enhanced GFP for quantification of functional expression, determination of sub-cellular localization, estimation of in vivo folding efficiency and establishment of a purification protocol. Aquaporin-1 was found to constitute 8.5 percent of total membrane protein content after expression at 15°C in a yeast host over-producing the Gal4p transcriptional activator and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30°C was due to in vivo mal-folding. Reduction of the expression temperature to 15°C almost completely prevented Aquaporin-1 mal-folding. Bioimaging of live yeast cells revealed that recombinant Aquaporin-1 accumulated in the yeast plasma membrane. A detergent screen for solubilization revealed that CYMAL-5 was superior in solubilizing recombinant Aquaporin-1 and generated a monodisperse protein preparation. A single Ni-affinity chromatography step was used to obtain almost pure Aquaporin-1. Recombinant Aquaporin-1 produced in S. cerevisiae was not N-glycosylated in contrast to the protein found in human erythrocytes.

  15. A murine monoclonal anti-idiotypic antibody detects a common idiotope on human, mouse and rabbit antibodies to allergen Lol p IV.

    Science.gov (United States)

    Zhou, E M; Dzuba-Fischer, J M; Rector, E S; Sehon, A H; Kisil, F T

    1991-09-01

    A syngeneic mouse monoclonal anti-idiotypic antibody (anti-Id), designated as B1/1, was generated against a monoclonal antibody (MoAb 91) specific for Ryegrass pollen allergen Lol p IV. This anti-Id recognized an idiotope (Id) that was also present on other monoclonal antibodies with the same specificity as MoAb 91. Observations that (i) the anti-Id inhibited the binding of MoAb 91 to Lol p IV and (ii) the Id-anti-Id interaction could be inhibited by Lol p IV indicated that the Id was located within or near the antigen combining site. These properties served to characterize B1/1 as an internal image anti-Id. Evidence that an immune response in different species to Lol p IV elicits the formation of antibodies which express a common Id was provided by the observations that (i) the Id-anti-Id interactions could be inhibited by mouse, human and rabbit antisera to Lol p IV and (ii) the binding of these antisera to Lol p IV could be inhibited by the anti-Id. Interestingly, the internal image anti-Id B1/1 also recognized an Id on a monoclonal antibody which was directed to an epitope of Lol p IV, different from that recognized by MoAb 91.

  16. Recombination in circulating Human enterovirus B: independent evolution of structural and non-structural genome regions.

    Science.gov (United States)

    Lukashev, Alexander N; Lashkevich, Vasilii A; Ivanova, Olga E; Koroleva, Galina A; Hinkkanen, Ari E; Ilonen, Jorma

    2005-12-01

    The complete nucleotide sequences of eight Human enterovirus B (HEV-B) strains were determined, representing five serotypes, E6, E7, E11, CVB3 and CVB5, which were isolated in the former Soviet Union between 1998 and 2002. All strains were mosaic recombinants and only the VP2-VP3-VP1 genome region was similar to that of the corresponding prototype HEV-B strains. In seven of the eight strains studied, the 2C-3D genome region was most similar to the prototype E30, EV74 and EV75 strains, whilst the remaining strain was most similar to the prototype E1 and E9 strains in the non-structural protein genome region. Most viruses also bore marks of additional recombination events in this part of the genome. In the 5' non-translated region, all strains were more similar to the prototype E9 than to other enteroviruses. In most cases, recombination mapped to the VP4 and 2ABC genome regions. This, together with the star-like topology of the phylogenetic trees for these genome regions, identified these genome parts as recombination hot spots. These findings further support the concept of independent evolution of enterovirus genome fragments and indicate a requirement for more advanced typing approaches. A range of available phylogenetic methods was also compared for efficient detection of recombination in enteroviruses.

  17. Monoclonal Antibodies production technology

    Directory of Open Access Journals (Sweden)

    Flávia Rocha

    2011-02-01

    Full Text Available Since the first cells were capable of maintain a continuous antibody supply, developed by Köhler and Milstein in 1975, its use in medicine and industry showed a great potential. New researches were developed to enhance the use of such cells, including immunizations, mieloma cells, fusion methodology, screening techniques, cloning, culture media, among several details which enable and optimizes its use. Nowadays, monoclonal antibodies are a well-established tool for proteomics research and it have countless applications on several knowledge areas, mainly human and/or animal disease diagnostic, identification and tracking of allergenic compounds in food and residues in the environment. This review can be used by professionals, researches and students searching for a compiled papers contributing to the improvement of the monoclonal antibodies technology, used at different knowledge areas such as human diseases and diseases and disorders in agriculture and livestock chain.

  18. Monoclonal Antibodies.

    Science.gov (United States)

    Geskin, Larisa J

    2015-10-01

    Use of monoclonal antibodies (mAbs) has revolutionized cancer therapy. Approaches targeting specific cellular targets on the malignant cells and in tumor microenvironment have been proved to be successful in hematologic malignancies, including cutaneous lymphomas. mAb-based therapy for cutaneous T-cell lymphoma has demonstrated high response rates and a favorable toxicity profile in clinical trials. Several antibodies and antibody-based conjugates are approved for use in clinical practice, and many more are in ongoing and planned clinical trials. In addition, these safe and effective drugs can be used as pillars for sequential therapies in a rational stepwise manner. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. [How safe is the recombinant human growth hormone?

    Science.gov (United States)

    Calzada-León, Raúl

    2017-01-01

    In this paper, several aspects related to the safety of the use of biosynthetic human growth hormone are reviewed. For example, its classification as a biosynthetic drug, the phases that need to be performed in Mexico to verify its safety (obtaining, purification, preclinical studies, clinical trials, and finally observational clinical studies), as well as the evidence that exists in relation to the association of intracranial hypertension, muscular events, scoliosis, slipped capital femoral epiphysis, obstructive sleep apnea, pancreatitis, alterations in cortisol, thyroid hormones alterations, cardiovascular disease, metabolic risk, mortality and cancer, adverse events not related to its use, and finally dosing and safety.

  20. Monoclonal antibodies to human glycophorin A and cell lines for the production thereof

    Science.gov (United States)

    Vanderlaan, Martin; Bigbee, William L.; Jensen, Ronald H.; Fong, Stella S. N.; Langlois, Richard G.

    1988-01-01

    Cloned mouse hybridoma cell lines have been established which continuously produce antibodies that are highly specific to and exhibit high affinity for glycophorin A.sup.N and differentiate between the M and N forms of human glycophorin A.

  1. First-in-Human Phase I Study of Lumretuzumab, a Glycoengineered Humanized Anti-HER3 Monoclonal Antibody, in Patients with Metastatic or Advanced HER3-Positive Solid Tumors

    DEFF Research Database (Denmark)

    Meulendijks, Didier; Jacob, Wolfgang; Martinez-Garcia, Maria

    2016-01-01

    PURPOSE: A first-in-human phase I study was conducted to characterize safety, efficacy, and pharmacokinetic (PK) and pharmacodynamic (PD) properties of lumretuzumab, a humanized and glycoengineered anti-HER3 monoclonal antibody, in patients with advanced cancer. EXPERIMENTAL DESIGN: Twenty-five p...

  2. First-in-Human Phase I Study of Lumretuzumab, a Glycoengineered Humanized Anti-HER3 Monoclonal Antibody, in Patients with Metastatic or Advanced HER3-Positive Solid Tumors

    NARCIS (Netherlands)

    Meulendijks, Didier; Jacob, Wolfgang; Martinez-Garcia, Maria; Taus, Alvaro; Lolkema, Martijn P; Voest, Emile E; Langenberg, Marlies H G; Fleitas Kanonnikoff, Tania; Cervantes, Andres; De Jonge, Maja J; Sleijfer, Stefan; Soerensen, Morten Mau; Thomas, Marlene; Ceppi, Maurizio; Meneses-Lorente, Georgina; James, Ian; Adessi, Celine; Michielin, Francesca; Abiraj, Keelara; Bossenmaier, Birgit; Schellens, Jan H M; Weisser, Martin; Lassen, Ulrik N

    2016-01-01

    PURPOSE: A first-in-human phase I study was conducted to characterize safety, efficacy, and pharmacokinetic (PK) and pharmacodynamic (PD) properties of lumretuzumab, a humanized and glycoengineered anti-HER3 monoclonal antibody, in patients with advanced cancer. EXPERIMENTAL DESIGN: Twenty-five

  3. RI-1: a chemical inhibitor of RAD51 that disrupts homologous recombination in human cells.

    Science.gov (United States)

    Budke, Brian; Logan, Hillary L; Kalin, Jay H; Zelivianskaia, Anna S; Cameron McGuire, William; Miller, Luke L; Stark, Jeremy M; Kozikowski, Alan P; Bishop, Douglas K; Connell, Philip P

    2012-08-01

    Homologous recombination serves multiple roles in DNA repair that are essential for maintaining genomic stability. We here describe RI-1, a small molecule that inhibits the central recombination protein RAD51. RI-1 specifically reduces gene conversion in human cells while stimulating single strand annealing. RI-1 binds covalently to the surface of RAD51 protein at cysteine 319 that likely destabilizes an interface used by RAD51 monomers to oligomerize into filaments on DNA. Correspondingly, the molecule inhibits the formation of subnuclear RAD51 foci in cells following DNA damage, while leaving replication protein A focus formation unaffected. Finally, it potentiates the lethal effects of a DNA cross-linking drug in human cells. Given that this inhibitory activity is seen in multiple human tumor cell lines, RI-1 holds promise as an oncologic drug. Furthermore, RI-1 represents a unique tool to dissect the network of reaction pathways that contribute to DNA repair in cells.

  4. Recombinant Production of Human Aquaporin-1 to an Exceptional High Membrane Density in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Bomholt, Julie; Helix Nielsen, Claus; Scharff-Poulsen, Peter

    2013-01-01

    In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C...... at 15°C in a yeast host over-producing the Gal4p transcriptional activator and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30°C was due to in vivo mal-folding. Reduction...... and generated a monodisperse protein preparation. A single Ni-affinity chromatography step was used to obtain almost pure Aquaporin-1. Recombinant Aquaporin-1 produced in S. cerevisiae was not N-glycosylated in contrast to the protein found in human erythrocytes....

  5. Dextrose-mediated aggregation of therapeutic monoclonal antibodies in human plasma: Implication of isoelectric precipitation of complement proteins

    Science.gov (United States)

    Luo, Shen; Zhang, Baolin

    2015-01-01

    Many therapeutic monoclonal antibodies (mAbs) are clinically administered through intravenous infusion after mixing with a diluent, e.g., saline, 5% dextrose. Such a clinical setting increases the likelihood of interactions among mAb molecules, diluent, and plasma components, which may adversely affect product safety and efficacy. Avastin® (bevacizumab) and Herceptin® (trastuzumab), but not Remicade® (infliximab), were shown to undergo rapid aggregation upon dilution into 5% dextrose when mixed with human plasma in vitro; however, the biochemical pathways leading to the aggregation were not clearly defined. Here, we show that dextrose-mediated aggregation of Avastin or Herceptin in plasma involves isoelectric precipitation of complement proteins. Using mass spectrometry, we found that dextrose-induced insoluble aggregates were composed of mAb itself and multiple abundant plasma proteins, namely complement proteins C3, C4, factor H, fibronectin, and apolipoprotein. These plasma proteins, which are characterized by an isoelectronic point of 5.5–6.7, lost solubility at the resulting pH in the mixture with formulated Avastin (pH 6.2) and Herceptin (pH 6.0). Notably, switching formulation buffers for Avastin (pH 6.2) and Remicade (pH 7.2) reversed their aggregation profiles. Avastin formed little, if any, insoluble aggregates in dextrose-plasma upon raising the buffer pH to 7.2 or above. Furthermore, dextrose induced pH-dependent precipitation of plasma proteins, with massive insoluble aggregates being detected at pH 6.5–6.8. These data show that isoelectric precipitation of complement proteins is a prerequisite of dextrose-induced aggregation of mAb in human plasma. This finding highlights the importance of assessing the compatibility of a therapeutic mAb with diluent and human plasma during product development. PMID:26338058

  6. Dextrose-mediated aggregation of therapeutic monoclonal antibodies in human plasma: Implication of isoelectric precipitation of complement proteins.

    Science.gov (United States)

    Luo, Shen; Zhang, Baolin

    2015-01-01

    Many therapeutic monoclonal antibodies (mAbs) are clinically administered through intravenous infusion after mixing with a diluent, e.g., saline, 5% dextrose. Such a clinical setting increases the likelihood of interactions among mAb molecules, diluent, and plasma components, which may adversely affect product safety and efficacy. Avastin® (bevacizumab) and Herceptin® (trastuzumab), but not Remicade® (infliximab), were shown to undergo rapid aggregation upon dilution into 5% dextrose when mixed with human plasma in vitro; however, the biochemical pathways leading to the aggregation were not clearly defined. Here, we show that dextrose-mediated aggregation of Avastin or Herceptin in plasma involves isoelectric precipitation of complement proteins. Using mass spectrometry, we found that dextrose-induced insoluble aggregates were composed of mAb itself and multiple abundant plasma proteins, namely complement proteins C3, C4, factor H, fibronectin, and apolipoprotein. These plasma proteins, which are characterized by an isoelectronic point of 5.5-6.7, lost solubility at the resulting pH in the mixture with formulated Avastin (pH 6.2) and Herceptin (pH 6.0). Notably, switching formulation buffers for Avastin (pH 6.2) and Remicade (pH 7.2) reversed their aggregation profiles. Avastin formed little, if any, insoluble aggregates in dextrose-plasma upon raising the buffer pH to 7.2 or above. Furthermore, dextrose induced pH-dependent precipitation of plasma proteins, with massive insoluble aggregates being detected at pH 6.5-6.8. These data show that isoelectric precipitation of complement proteins is a prerequisite of dextrose-induced aggregation of mAb in human plasma. This finding highlights the importance of assessing the compatibility of a therapeutic mAb with diluent and human plasma during product development.

  7. High-Avidity and Potently Neutralizing Cross-Reactive Human Monoclonal Antibodies Derived from Secondary Dengue Virus Infection

    Science.gov (United States)

    Tsai, Wen-Yang; Lai, Chih-Yun; Wu, Yi-Chieh; Lin, Hong-En; Edwards, Carolyn; Jumnainsong, Amonrat; Kliks, Srisakul; Halstead, Scott; Mongkolsapaya, Juthathip; Screaton, Gavin R.

    2013-01-01

    The envelope (E) protein of dengue virus (DENV) is the major target of neutralizing antibodies (Abs) and vaccine development. Previous studies of human dengue-immune sera reported that a significant proportion of anti-E Abs, known as group-reactive (GR) Abs, were cross-reactive to all four DENV serotypes and to one or more other flaviviruses. Based on studies of mouse anti-E monoclonal antibodies (MAbs), GR MAbs were nonneutralizing or weakly neutralizing compared with type-specific MAbs; a GR response was thus not regarded as important for vaccine strategy. We investigated the epitopes, binding avidities, and neutralization potencies of 32 human GR anti-E MAbs. In addition to fusion loop (FL) residues in E protein domain II, human GR MAbs recognized an epitope involving both FL and bc loop residues in domain II. The neutralization potencies and binding avidities of GR MAbs derived from secondary DENV infection were stronger than those derived from primary infection. GR MAbs derived from primary DENV infection primarily blocked attachment, whereas those derived from secondary infection blocked DENV postattachment. Analysis of the repertoire of anti-E MAbs derived from patients with primary DENV infection revealed that the majority were GR, low-avidity, and weakly neutralizing MAbs, whereas those from secondary infection were primarily GR, high-avidity, and potently neutralizing MAbs. Our findings suggest that the weakly neutralizing GR anti-E Abs generated from primary DENV infection become potently neutralizing MAbs against the four serotypes after secondary infection. The observation that the dengue immune status of the host affects the quality of the cross-reactive Abs generated has implications for new strategies for DENV vaccination. PMID:24027331

  8. Monoclonal antibody to a subset of human monocytes found only in the peripheral blood and inflammatory tissues

    Energy Technology Data Exchange (ETDEWEB)

    Zwadlo, G.; Schlegel, R.; Sorg, C.

    1986-07-15

    A monoclonal antibody is described that was generated by immunizing mice with cultured human blood monocytes. The antibody (27E10) belongs to the IgG1 subclass and detects a surface antigen at M/sub r/ 17,000 that is found on 20% of peripheral blood monocytes. The antigen is increasingly expressed upon culture of monocytes, reaching a maximum between days 2 and 3. Stimulation of monocytes with interferon-..gamma.. (IFN-..gamma..), 12-O-tetradecanoyl-phorbol-13-acetate (TPA), and lipopolysaccharide (LPS) Ylalanine (fMLP) increased the 27E10 antigen density. The amount of 27E10-positive cells is not or is only weakly affected. The antigen is absent from platelets, lymphotyces, and all tested human cell lines, yet it cross-reacts with 15% of freshly isolated granulocytes. By using the indirect immunoperoxidase technique, the antibody is found to be negative on cryostat sections of normal human tissue (skin, lung, and colon) and positive on only a few monocyte-like cells in liver and on part of the cells of the splenic red pulp. In inflammatory tissue, however, the antibody is positive on monocytes/macrophages and sometimes on endothelial cells and epidermal cells, depending on the stage and type of inflammation, e.g., BCG ranulomas are negative, whereas psoriasis vulgaris, atopic dermatitis, erythrodermia, pressure urticaria, and periodontitis contain positively staining cells. In contact eczemas at different times after elicitation (6 hr, 24 hr, and 72 hr), the 27E10 antigen is seen first after 24 hr on a few infiltrating monocytes/macrophages, which increase in numbers after 72 hr.

  9. Homotypic aggregation of human cell lines by HLA class II-, class Ia- and HLA-G-specific monoclonal antibodies

    DEFF Research Database (Denmark)

    Odum, Niels; Ledbetter, J A; Martin, P

    1991-01-01

    adhesion between T and B cells by activating the CD18/CD11a (LFA-1) adhesion pathway. Here we report that monoclonal antibodies (mAb) against HLA-DR (L243, p4.1, HB10a, VI15) and certain broad class II reacting mAb (TU35, TU39), but not anti-DQ (TU22, Leu-10) mAb, induced homotypic aggregation of human......, but not the class I-negative parental line, 221, showed homotypic aggregation in response to an HLA-G specific mAb (87G) and a broad reacting class I-specific mAb (IOT2). Both cell lines responded with aggregation to anti-class II mAb (TU35). The anti-class I mAb, W6/32, had no effect on all cell lines tested......Major histocompatibility complex (MHC) class II molecules have been implicated in cell adhesion in two ways. In addition to the well-established role of class II antigens in low-affinity adhesion provided by interactions between class II and CD4, recent data indicated that class II may also induce...

  10. An epitope tag derived from human transcription factor IIB that reacts with a polyol-responsive monoclonal antibody.

    Science.gov (United States)

    Duellman, Sarah J; Thompson, Nancy E; Burgess, Richard R

    2004-05-01

    Polyol-responsive monoclonal antibodies (PR-mAbs) provide a strategy to purify active, nondenatured proteins by a single-step immunoaffinity chromatography procedure. The high affinity interaction between these antibodies and the antigen can be dissociated in the presence of a nonchaotropic salt and a low molecular weight polyhydroxylated compound (polyol). The epitope for PR-mAb IIB8 is located near the N-terminus of the human transcription factor IIB (TFIIB). The epitope is an eight amino acid sequence, TKDPSRVG, that can be fused to a desired protein for use as a purification tag. This epitope tag (termed hIIB) was fused to the C-terminus of green fluorescent protein (GFP). An additional GFP fusion protein utilized another version of hIIB containing a point mutation at position two. These fusion proteins, expressed in Escherichia coli, allowed successful separation of the desired protein in a single chromatographic step. This strategy extends PR-mAb gentle-release purification to numerous expressed proteins.

  11. Neutralization of Zika virus by germline-like human monoclonal antibodies targeting cryptic epitopes on envelope domain III.

    Science.gov (United States)

    Wu, Yanling; Li, Shun; Du, Lanying; Wang, Chunyu; Zou, Peng; Hong, Binbin; Yuan, Mengjiao; Ren, Xiaonan; Tai, Wanbo; Kong, Yu; Zhou, Chen; Lu, Lu; Zhou, Xiaohui; Jiang, Shibo; Ying, Tianlei

    2017-10-11

    The Zika virus (ZIKV), a flavivirus transmitted by Aedes mosquitoes, has emerged as a global public health concern. Pre-existing cross-reactive antibodies against other flaviviruses could modulate immune responses to ZIKV infection by antibody-dependent enhancement, highlighting the importance of understanding the immunogenicity of the ZIKV envelope protein. In this study, we identified a panel of human monoclonal antibodies (mAbs) that target domain III (DIII) of the ZIKV envelope protein from a very large phage-display naive antibody library. These germline-like antibodies, sharing 98%-100% hoLogy with their corresponding germline IGHV genes, bound ZIKV DIII specifically with high affinities. One mAb, m301, broadly neutralized the currently circulating ZIKV strains and showed a synergistic effect with another mAb, m302, in neutralizing ZIKV in vitro and in a mouse model of ZIKV infection. Interestingly, epitope mapping and competitive binding studies suggest that m301 and m302 bind adjacent regions of the DIII C-C' loop, which represents a recently identified cryptic epitope that is intermittently exposed in an uncharacterized virus conformation. This study extended our understanding of antigenic epitopes of ZIKV antibodies and has direct implications for the design of ZIKV vaccines.

  12. Generation and characterization of new monoclonal antibodies targeting the PHF1 and AT8 epitopes on human tau.

    Science.gov (United States)

    Strang, Kevin H; Goodwin, Marshall S; Riffe, Cara; Moore, Brenda D; Chakrabarty, Paramita; Levites, Yona; Golde, Todd E; Giasson, Benoit I

    2017-07-31

    Tauopathies are a group of neurodegenerative disorders, including Alzheimer's disease, defined by the presence of brain pathological inclusions comprised of abnormally aggregated and highly phosphorylated tau protein. The abundance of brain tau aggregates correlates with disease severity and select phospho-tau epitopes increase at early stages of disease. We generated and characterized a series of novel monoclonal antibodies directed to tau phosphorylated at several of these phospho-epitopes, including Ser396/Ser404, Ser404 and Thr205. We also generated phosphorylation independent antibodies against amino acid residues 193-211. We show that most of these antibodies are highly specific for tau and strongly recognize pathological inclusions in human brains and in a transgenic mouse model of tauopathy. They also reveal epitope-specific differences in the biochemical properties of Alzheimer's disease sarkosyl-insoluble tau. These new reagents will be useful for investigating the progression of tau pathology and further as tools to target the cellular transmission of tau pathology.

  13. Development of monoclonal antibodies to human microsomal epoxide hydrolase and analysis of “preneoplastic antigen”-like molecules

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Hongying [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Yoshimura, Kazunori [Department of Physiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Kobayashi, Nobuharu; Sugiyama, Kazuo [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Sawada, Jun-ichi; Saito, Yoshiro [Division of Biochemistry and Immunochemistry, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo 158-8501 (Japan); Morisseau, Christophe; Hammock, Bruce D. [Department of Entomology and Cancer Center, University of California, Davis, One Shields Avenue, Davis, CA 95616-8584 (United States); Akatsuka, Toshitaka, E-mail: akatsuka@saitama-med.ac.jp [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan)

    2012-04-01

    Microsomal epoxide hydrolase (mEH) is a drug metabolizing enzyme which resides on the endoplasmic reticulum (ER) membrane and catalyzes the hydration of reactive epoxide intermediates that are formed by cytochrome P450s. mEH is also thought to have a role in bile acid transport on the plasma membrane of hepatocytes. It is speculated that efficient execution of such multiple functions is secured by its orientation and association with cytochrome P450 enzymes on the ER membrane and formation of a multiple transport system on the plasma membrane. In certain disease status, mEH loses its association with the membrane and can be detected as distinct antigens in the cytosol of preneoplastic foci of liver (preneoplastic antigen), in the serum in association with hepatitis C virus infection (AN antigen), or in some brain tumors. To analyze the antigenic structures of mEH in physiological and pathological conditions, we developed monoclonal antibodies against different portions of mEH. Five different kinds of antibodies were obtained: three, anti-N-terminal portions; one anti-C-terminal; and one, anti-conformational epitope. By combining these antibodies, we developed antigen detection methods which are specific to either the membrane-bound form or the linearized form of mEH. These methods detected mEH in the culture medium released from a hepatocellular carcinoma cell line and a glioblastoma cell line, which was found to be a multimolecular complex with a unique antigenic structure different from that of the membrane-bound form of mEH. These antibodies and antigen detection methods may be useful to study pathological changes of mEH in various human diseases. -- Highlights: ► Monoclonal antibodies against different portions of mEH were developed. ► They discriminate between the membrane-bound and the linearized forms of mEH. ► We analyze the antigenic structure of the altered form of mEH in tumor cells. ► Preneoplastic antigen is a multimolecular complex of mEH with

  14. Affinity isolation of antigen-specific circulating B cells for generation of phage display-derived human monoclonal antibodies

    DEFF Research Database (Denmark)

    Ditzel, Henrik

    2009-01-01

    A method is described for affinity isolation of antigen-specific circulating B cells of interest for subsequent generation of immune antibody phage display libraries. This approach should overcome the problem of low yields of monoclonal antibodies of interest in the libraries generated from...... the frequency of antibody phage particles of interest in the library and allow for efficient isolation monoclonal antibodies with the predefined specificity....

  15. B-cell display-based one-step method to generate chimeric human IgG monoclonal antibodies

    OpenAIRE

    Lin, Waka; Kurosawa, Kohei; Murayama, Akiho; Kagaya, Eri; Ohta, Kunihiro

    2010-01-01

    The recent development of screening strategies based on the generation and display of large libraries of antibody fragments has allowed considerable advances for the in vitro isolation of monoclonal antibodies (mAbs). We previously developed a technology referred to as the ‘ADLib (Autonomously Diversifying Library) system’, which allows the rapid screening and isolation in vitro of antigen-specific monoclonal antibodies (mAbs) from libraries of immunoglobulin M (IgM) displayed by the chicken ...

  16. Transgenic mouse strains as platforms for the successful discovery and development of human therapeutic monoclonal antibodies.

    Science.gov (United States)

    Green, Larry L

    2014-03-01

    Transgenic mice have yielded seven of the ten currently-approved human antibody drugs, making them the most successful platform for the discovery of fully human antibody therapeutics. The use of the in vivo immune system helps drive this success by taking advantage of the natural selection process that produces antibodies with desirable characteristics. Appropriately genetically-engineered mice act as robust engines for the generation of diverse repertoires of affinity- matured fully human variable regions with intrinsic properties necessary for successful antibody drug development including high potency, specificity, manufacturability, solubility and low risk of immunogenicity. A broad range of mAb drug targets are addressable in these mice, comprising both secreted and transmembrane targets, including membrane multi-spanning targets, as well as human target antigens that share high sequence identity with their mouse orthologue. Transgenic mice can routinely yield antibodies with sub-nanomolar binding affinity for their antigen, with lead candidate mAbs frequently possessing affinities for binding to their target of less than 100 picomolar, without requiring any ex vivo affinity optimization. While the originator transgenic mice platforms are no longer broadly available, a new generation of transgenic platforms is in development for discovery of the next wave of human therapeutic antibodies.

  17. A novel multi-epitope recombined protein for diagnosis of human brucellosis.

    Science.gov (United States)

    Yin, Dehui; Li, Li; Song, Xiuling; Li, Han; Wang, Juan; Ju, Wen; Qu, Xiaofeng; Song, Dandan; Liu, Yushen; Meng, Xiangjun; Cao, Hongqian; Song, Weiyi; Meng, Rizeng; Liu, Jinhua; Li, Juan; Xu, Kun

    2016-05-21

    In epidemic regions of the world, brucellosis is a reemerging zoonosis with minimal mortality but is a serious public hygiene problem. Currently, there are various methods for brucellosis diagnosis, however few of them are available to be used to diagnose, especially for serious cross-reaction with other bacteria. To overcome this disadvantage, we explored a novel multi-epitope recombinant protein as human brucellosis diagnostic antigen. We established an indirect enzyme-linked immunosorbent assay (ELISA) based on this recombinant protein. 248 sera obtained from three different groups including patients with brucellosis (146 samples), non-brucellosis patients (82 samples), and healthy individuals (20 samples) were tested by indirect ELISA. To evaluate the assay, a receiver-operating characteristic (ROC) analysis and immunoblotting were carried out using these characterized serum samples. For this test, the area under the ROC curve was 0.9409 (95 % confidence interval, 0.9108 to 0.9709), and a sensitivity of 88.89 % and a specificity of 85.54 % was given with a cutoff value of 0.3865 from this ROC analysis. The Western blot results indicate that it is feasible to differentiate human brucellosis and non-brucellosis with the newly established method based on this recombinant protein. Our results obtained high diagnostic accuracy of the ELISA assay which encourage the use of this novel recombinant protein as diagnostic antigen to implement serological diagnosis of brucellosis.

  18. Maintenance of Hepatic Functions in Primary Human Hepatocytes Cultured on Xeno-Free and Chemical Defined Human Recombinant Laminins.

    Science.gov (United States)

    Watanabe, Masaaki; Zemack, Helen; Johansson, Helene; Hagbard, Louise; Jorns, Carl; Li, Meng; Ellis, Ewa

    2016-01-01

    Refined methods for maintaining specific functions of isolated hepatocytes under xeno-free and chemical defined conditions is of great importance for the development of hepatocyte research and regenerative therapy. Laminins, a large family of heterotrimeric basement membrane adhesion proteins, are highly cell and tissue type specific components of the extracellular matrix and strongly influence the behavior and function of associated cells and/or tissues. However, detailed biological functions of many laminin isoforms are still to be evaluated. In this study, we determined the distribution of laminin isoforms in human liver tissue and isolated primary human hepatocytes by western blot analysis, and investigated the efficacy of different human recombinant laminin isoforms on hepatic functions during culture. Protein expressions of laminin-chain α2, α3, α4, β1, β3, γ1, and γ2 were detected in both isolated human hepatocytes and liver tissue. No α1 and α5 expression could be detected in liver tissue or hepatocytes. Hepatocytes were isolated from five different individual livers, and cultured on human recombinant laminin isoforms -111, -211, -221, -332, -411, -421, -511, and -521 (Biolamina AB), matrigel (extracted from Engelbreth-Holm-Swarm sarcoma), or collagen type IV (Collagen). Hepatocytes cultured on laminin showed characteristic hexagonal shape in a flat cell monolayer. Viability, double stranded DNA concentration, and Ki67 expression for hepatocytes cultured for six days on laminin were comparable to those cultured on EHS and Collagen. Hepatocytes cultured on laminin also displayed production of human albumin, alpha-1-antitrypsin, bile acids, and gene expression of liver-enriched factors, such as hepatocyte nuclear factor 4 alpha, glucose-6-phosphate, cytochrome P450 3A4, and multidrug resistance-associated protein 2. We conclude that all forms of human recombinant laminin tested maintain cell viability and liver-specific functions of primary human

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

    Science.gov (United States)

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

    2014-01-01

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

  20. Recombinant expression of homodimeric 660 kDa human thyroglobulin in soybean seeds: an alternative source of human thyroglobulin.

    Science.gov (United States)

    Powell, Rebecca; Hudson, Laura C; Lambirth, Kevin C; Luth, Diane; Wang, Kan; Bost, Kenneth L; Piller, Kenneth J

    2011-07-01

    Soybean seeds possess many qualities that make them ideal targets for the production of recombinant proteins. However, one quality often overlooked is their ability to stockpile large amounts of complex storage proteins. Because of this characteristic, we hypothesized that soybean seeds would support recombinant expression of large and complex proteins that are currently difficult or impossible to express using traditional plant and non-plant-based host systems. To test this hypothesis, we transformed soybeans with a synthetic gene encoding human thyroglobulin (hTG)-a 660 kDa homodimeric protein that is widely used in the diagnostic industry for screening and detection of thyroid disease. In the absence of a recombinant system that can produce recombinant hTG, research and diagnostic grade hTG continues to be purified from cadaver and surgically removed thyroid tissue. These less-than-ideal tissue sources lack uniform glycosylation and iodination and therefore introduce variability when purified hTG is used in sensitive ELISA screens. In this study, we report the successful expression of recombinant hTG in soybean seeds. Authenticity of the soy-derived protein was demonstrated using commercial ELISA kits developed specifically for the detection of hTG in patient sera. Western analyses and gel filtration chromatography demonstrated that recombinant hTG and thyroid-purified hTG are biologically similar with respect to size, mass, charge and subunit interaction. The recombinant protein was stable over three generations and accumulated to ~1.5% of total soluble seed protein. These results support our hypothesis that soybeans represent a practical alternative to traditional host systems for the expression of large and complex proteins.

  1. Prophylactic and postexposure efficacy of a potent human monoclonal antibody against MERS coronavirus

    Science.gov (United States)

    Corti, Davide; Zhao, Jincun; Pedotti, Mattia; Simonelli, Luca; Agnihothram, Sudhakar; Fett, Craig; Fernandez-Rodriguez, Blanca; Foglierini, Mathilde; Agatic, Gloria; Vanzetta, Fabrizia; Gopal, Robin; Langrish, Christopher J.; Barrett, Nicholas A; Sallusto, Federica; Baric, Ralph S.; Varani, Luca; Zambon, Maria; Perlman, Stanley; Lanzavecchia, Antonio

    2015-01-01

    Middle East Respiratory Syndrome (MERS) is a highly lethal pulmonary infection caused by a previously unidentified coronavirus (CoV), likely transmitted to humans by infected camels. There is no licensed vaccine or antiviral for MERS, therefore new prophylactic and therapeutic strategies to combat human infections are needed. In this study, we describe, for the first time, to our knowledge, the isolation of a potent MERS-CoV–neutralizing antibody from memory B cells of an infected individual. The antibody, named LCA60, binds to a novel site on the spike protein and potently neutralizes infection of multiple MERS-CoV isolates by interfering with the binding to the cellular receptor CD26. Importantly, using mice transduced with adenovirus expressing human CD26 and infected with MERS-CoV, we show that LCA60 can effectively protect in both prophylactic and postexposure settings. This antibody can be used for prophylaxis, for postexposure prophylaxis of individuals at risk, or for the treatment of human cases of MERS-CoV infection. The fact that it took only 4 mo from the initial screening of B cells derived from a convalescent patient for the development of a stable chinese hamster ovary (CHO) cell line producing neutralizing antibodies at more than 5 g/L provides an example of a rapid pathway toward the generation of effective antiviral therapies against emerging viruses. PMID:26216974

  2. The value of non-human primates in the development of therapeutic monoclonal antibodies

    NARCIS (Netherlands)

    Van Meer, P.J.K.|info:eu-repo/dai/nl/34153790X; Kooijman, M.|info:eu-repo/dai/nl/322905788; Van Der Laan, J.W.|info:eu-repo/dai/nl/374879966; Moors, E.H.M.|info:eu-repo/dai/nl/20241664X; Schellekens, H.|info:eu-repo/dai/nl/068406762

    2011-01-01

    The pharmaceutical industry is increasingly focusing on the development of biological therapeutics. These molecules generally cause no off-target toxicity and are highly species specific. Therefore, non-human primates (NHPs) are often the only relevant species in which to conduct regulatory safety

  3. Recombinant human albumin supports single cell cloning of CHO cells in chemically defined media.

    Science.gov (United States)

    Zhu, Jiang; Wooh, Jong Wei; Hou, Jeff Jia Cheng; Hughes, Benjamin S; Gray, Peter P; Munro, Trent P

    2012-01-01

    Biologic drugs, such as monoclonal antibodies, are commonly made using mammalian cells in culture. The cell lines used for manufacturing should ideally be clonal, meaning derived from a single cell, which represents a technically challenging process. Fetal bovine serum is often used to support low cell density cultures, however, from a regulatory perspective, it is preferable to avoid animal-derived components to increase process consistency and reduce the risk of contamination from adventitious agents. Chinese hamster ovary (CHO) cells are the most widely used cell line in industry and a large number of serum-free, protein-free, and fully chemically defined growth media are commercially available, although these media alone do not readily support efficient single cell cloning. In this work, we have developed a simple, fully defined, single-cell cloning media, specifically for CHO cells, using commercially available reagents. Our results show that a 1:1 mixture of CD-CHO™ and DMEM/F12 supplemented with 1.5 g/L of recombinant albumin (Albucult®) supports single cell cloning. This formulation can support recovery of single cells in 43% of cultures compared to 62% in the presence of serum. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  4. Applying antibody-sensitive hypervariable region 1-deleted hepatitis C virus to the study of escape pathways of neutralizing human monoclonal antibody AR5A

    Science.gov (United States)

    Velázquez-Moctezuma, Rodrigo; Bukh, Jens

    2017-01-01

    Hepatitis C virus (HCV) is a major cause of end-stage liver diseases. With 3–4 million new HCV infections yearly, a vaccine is urgently needed. A better understanding of virus escape from neutralizing antibodies and their corresponding epitopes are important for this effort. However, for viral isolates with high antibody resistance, or antibodies with moderate potency, it remains challenging to induce escape mutations in vitro. Here, as proof-of-concept, we used antibody-sensitive HVR1-deleted (ΔHVR1) viruses to generate escape mutants for a human monoclonal antibody, AR5A, targeting a rare cross-genotype conserved epitope. By analyzing the genotype 1a envelope proteins (E1/E2) of recovered Core-NS2 recombinant H77/JFH1ΔHVR1 and performing reverse genetic studies we found that resistance to AR5A was caused by substitution L665W, also conferring resistance to the parental H77/JFH1. The mutation did not induce viral fitness loss, but abrogated AR5A binding to HCV particles and intracellular E1/E2 complexes. Culturing J6/JFH1ΔHVR1 (genotype 2a), for which fitness was decreased by L665W, with AR5A generated AR5A-resistant viruses with the substitutions I345V, L665S, and S680T, which we introduced into J6/JFH1 and J6/JFH1ΔHVR1. I345V increased fitness but had no effect on AR5A resistance. L665S impaired fitness and decreased AR5A sensitivity, while S680T combined with L665S compensated for fitness loss and decreased AR5A sensitivity even further. Interestingly, S680T alone had no fitness effect but sensitized the virus to AR5A. Of note, H77/JFH1L665S was non-viable. The resistance mutations did not affect cell-to-cell spread or E1/E2 interactions. Finally, introducing L665W, identified in genotype 1, into genotypes 2–6 parental and HVR1-deleted variants (not available for genotype 4a) we observed diverse effects on viral fitness and a universally pronounced reduction in AR5A sensitivity. Thus, we were able to take advantage of the neutralization-sensitive HVR1

  5. Monoclonal antibodies to Pneumocystis carinii

    DEFF Research Database (Denmark)

    Kovacs, J A; Halpern, J L; Lundgren, B

    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...... antigenically different. Further studies with these antibodies should increase understanding of the antigenic nature of P. carinii and of the interaction of P. carinii with its host....

  6. Effect of recombinant and purified hematopoietic growth factors on human megakaryocyte colony formation.

    Science.gov (United States)

    Bruno, E; Briddell, R; Hoffman, R

    1988-06-01

    The effect of a number of purified or recombinant hematopoietic growth factors, including recombinant erythropoietin (rEpo), thrombocytopoiesis stimulating factor (TSF), recombinant interleukin 1 alpha (rIL-1 alpha), recombinant granulocyte colony-stimulating factor (rG-CSF), macrophage colony-stimulating factor (CSF-1), recombinant interleukin 3 (rIL-3), and recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF), on megakaryocyte (MK) colony formation by normal human marrow cells in a serum-depleted assay system was determined. Neither rEpo, TSF, CSF-1, rIL-1 alpha, nor rG-CSF alone augmented MK colony formation. Both rGM-CSF and rIL-3 at optimal doses increased MK colony formation eightfold and tenfold, respectively, above baseline values. Addition of increasing amounts of either rGM-CSF or rIL-3 led to progressively greater numbers of MK colonies formed until plateau levels were reached. Both rGM-CSF and rIL-3 also led to a dose-related increase in the number of cells per MK colony formed in culture. These molecules were equivalent stimulators of MK colony formation when their effects at optimal concentrations were compared. The effects of rGM-CSF and rIL-3 were additive at suboptimal concentrations of rIL-3 in that colony formation by a combination of the two growth factors approximated the sum of colony formation by each growth factor alone. These data suggest that rGM-CSF and rIL-3 alone and in combination are important regulators of in vitro megakaryocytopoiesis at the progenitor cell level.

  7. [Safety of human papillomavirus 6, 11, 16 and 18 (recombinant): systematic review and meta-analysis].

    Science.gov (United States)

    Coelho, Pedro Luiz Spinelli; da Silva Calestini, Gustavo Lacerda; Alvo, Fernando Salgueiro; de Moura Freitas, Jefferson Michel; Castro, Paula Marcela Vilela; Konstantyner, Tulio

    2015-12-01

    To identify and quantify the adverse effects associated with the recombinant human papillomavirus (types 6, 11, 16 and 18) vaccine in adolescents. Systematic review of randomized clinical trials from PubMed, SciELO and Lilacs databases. Articles investigating the safety of the vaccine in subjects under 18 years and comparing the recombinant human papillomavirus types 6, 11, 16 and 18 vaccine with a control group were included. Meta-analyses were performed for the outcomes of pain, erythema, swelling and fever, using clinical trials with maximum Jadad score. Fourteen studies were included. The most commons adverse effects related to the human papillomavirus vaccine were effects with no severity (pain, erythema, edema, and fever). Five studies were used for the meta-analyses: Pain-Risk Difference (RD)=11% (p<0.001); edema-RD=8% (p<0.001); erythema-RD=5% (p<0.001); fever-RD=2% (p<0.003). The recombinant human papillomavirus types 6, 11, 16 and 18 vaccine was safe and well tolerated. The main adverse effects related to vaccination were pain, erythema, edema and fever. The low frequency of severe adverse effects encourages the administration of the vaccine in the population at risk. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  8. Efficacy and safety of treatment with an anti-m2e monoclonal antibody in experimental human influenza.

    Science.gov (United States)

    Ramos, Eleanor L; Mitcham, Jennifer L; Koller, Teri D; Bonavia, Aurelio; Usner, Dale W; Balaratnam, Ganesh; Fredlund, Paul; Swiderek, Kristine M

    2015-04-01

    The efficacy of TCN-032, a human monoclonal antibody targeting a conserved epitope on M2e, was explored in experimental human influenza. Healthy volunteers were inoculated with influenza A/Wisconsin/67/2005 (H3N2) and received a single dose of the study drug, TCN-032, or placebo 24 hours later. Subjects were monitored for symptoms, viral shedding, and safety, including cytokine measurements. Oseltamivir was administered 7 days after inoculation. Although the primary objective of reducing the proportion of subjects developing any grade ≥2 influenza symptom or pyrexia, was not achieved, TCN-032-treated subjects showed 35% reduction (P = .047) in median total symptom area under the curve (days 1-7) and 2.2 log reduction in median viral load area under the curve (days 2-7) by quantitative polymerase chain reaction (P = .09) compared with placebo-treated subjects. TCN-032 was safe and well tolerated with no additional safety signals after administration of oseltamivir. Serum cytokine levels (interferon γ, tumor necrosis factor α, and interleukin 8 and 10) were similar in both groups. Genotypic and phenotypic analyses showed no difference between virus derived from subjects after TCN-032 treatment and parental strain. These data indicate that TCN-032 may provide immediate immunity and therapeutic benefit in influenza A infection, with no apparent emergence of resistant virus. TCN-032 was safe with no evidence of immune exacerbation based on serum cytokine expression. Clinicaltrials.gov registry number. NCT01719874. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. High affinity anti-TIM-3 and anti-KIR monoclonal antibodies cloned from healthy human individuals.

    Directory of Open Access Journals (Sweden)

    Stefan Ryser

    Full Text Available We report here the cloning of native high affinity anti-TIM-3 and anti-KIR IgG monoclonal antibodies (mAbs from peripheral blood mononuclear cells (PBMC of healthy human donors. The cells that express these mAbs are rare, present at a frequency of less than one per 105 memory B-cells. Using our proprietary multiplexed screening and cloning technology CellSpot™ we assessed the presence of memory B-cells reactive to foreign and endogenous disease-associated antigens within the same individual. When comparing the frequencies of antigen-specific memory B-cells analyzed in over 20 screening campaigns, we found a strong correlation of the presence of anti-TIM-3 memory B-cells with memory B-cells expressing mAbs against three disease-associated antigens: (i bacterial DNABII proteins that are a marker for Gram negative and Gram positive bacterial infections, (ii hemagglutinin (HA of influenza virus and (iii the extracellular domain of anaplastic lymphoma kinase (ALK. One of the native anti-KIR mAbs has similar characteristics as lirilumab, an anti-KIR mAb derived from immunization of humanized transgenic mice that is in ongoing clinical trials. It is interesting to speculate that these native anti-TIM-3 and anti-KIR antibodies may function as natural regulatory antibodies, analogous to the pharmacological use in cancer treatment of engineered antibodies against the same targets. Further characterization studies are needed to define the mechanisms through which these native antibodies may function in healthy and disease conditions.

  10. Developmental Toxicity and Fertility Assessment in Rabbits with Tabalumab: A Human IgG4 Monoclonal Antibody.

    Science.gov (United States)

    Breslin, William J; Hilbish, Kim G; Martin, Jennifer A; Halstead, Carolyn A; Edwards, Tammy L

    2015-06-01

    Tabalumab is a human immunoglobulin G subclass 4 monoclonal antibody that has been under development for autoimmune disorders. Tabalumab has full neutralizing activity against both soluble and membrane B-cell activating factor, a B-cell survival factor. The objectives of these studies were to assess the effects of tabalumab on embryo-fetal development and on male (M) and female (F) fertility in rabbits, a pharmacologically relevant species. Doses were administered at 0 (vehicle control), 0.3 (embryo-fetal study only), 1.0, and 30 mg/kg. In the embryo-fetal study, pregnant rabbits does were given a single dose by intravenous injection on gestation day (GD) 7. In the fertility studies, tabalumab was administered by intravenous injection every 7 days starting 2 (F) or 4 (M) weeks before mating, during cohabitation, and until necropsy (M) or through GD 18 (F). Treated animals were mated with untreated partners. Parental clinical signs, body weight, food consumption, blood lymphocyte phenotyping, organ weights, morphologic pathology, ovarian and uterine observations, sperm parameters, and fertility indices were evaluated along with conceptus viability, weight, and morphology. Exposure assessments were made in all main study animals and satellite animals. No adverse parental, reproductive, or developmental effects were observed in any study at any dose. A pharmacodynamic response consisting of dose-dependent decreases in the percent and number of total B lymphocytes and increases in the percent and/or number of total T lymphocytes was observed in parental rabbits at 1.0 and 30 mg/kg. In conclusion, no adverse reproductive or developmental effects were observed in rabbits following exposure to tabalumab at doses as high as 30 mg/kg and exposures at least 14-fold greater than human exposure levels. © 2015 Wiley Periodicals, Inc.

  11. Clearance Kinetics and External Dosimetry of Iodine-131-labeled Murine and Humanized Monoclonal Antibody A33 in Patients with Colon Cancer: Radiation Safety Implications

    OpenAIRE

    Dauer, Lawrence T.; Boylan, Daniel C; Williamson, Matthew J.; Germain, Jean St.; Steven M. Larson

    2009-01-01

    The monoclonal antibody (mAb) A33 detects a membrane antigen that is expressed on greater than 95% of metastatic human colorectal cancers. Previous studies have shown excellent tumor-targeting of iodine-131 labeled murine and humanized forms of the mAb. A retrospective analysis of whole body clearance in the murine form was performed for comparison to the humanized form. Serial whole-body dose rate measurements were obtained for 55 treatments on 30 patients participating in phase I/II dose es...

  12. Generation and characterization of ixekizumab, a humanized monoclonal antibody that neutralizes interleukin-17A.

    Science.gov (United States)

    Liu, Ling; Lu, Jirong; Allan, Barrett W; Tang, Ying; Tetreault, Jonathan; Chow, Chi-Kin; Barmettler, Barbra; Nelson, James; Bina, Holly; Huang, Lihua; Wroblewski, Victor J; Kikly, Kristine

    2016-01-01

    Interleukin (IL)-17A exists as a homodimer (A/A) or as a heterodimer (A/F) with IL-17F. IL-17A is expressed by a subset of T-cells, called Th17 cells, at inflammatory sites. Most cell types can respond to the local production of IL-17A because of the near ubiquitous expression of IL-17A receptors, IL-17RA and IL-17RC. IL-17A stimulates the release of cytokines and chemokines designed to recruit and activate both neutrophils and memory T-cells to the site of injury or inflammation and maintain a proinflammatory state. IL-17A-producing pathogenic T-cells contribute to the pathogenesis of autoimmune diseases, including psoriasis, psoriatic arthritis, rheumatoid arthritis, and ankylosing spondylitis. This study describes the generation and characterization of ixekizumab, a humanized IgG4 variant IL-17A-neutralizing antibody. Ixekizumab binds human and cynomolgus monkey IL-17A with high affinity and binds rabbit IL-17A weakly but does not bind to rodent IL-17A or other IL-17 family members. Ixekizumab effectively inhibits the interaction between IL-17A and its receptor in binding assays and potently blocks IL-17A-induced GRO or KC secretion in cell-based assays. In an in vivo mouse pharmcodynamic model, ixekizumab blocks human IL-17A-induced mouse KC secretion. These data provide a comprehensive preclinical characterization of ixekizumab, for which the efficacy and safety have been demonstrated in human clinical trials in psoriasis and psoriatic arthritis.

  13. Protection of non-human primates against rabies with an adenovirus recombinant vaccine.

    Science.gov (United States)

    Xiang, Z Q; Greenberg, L; Ertl, H C; Rupprecht, C E

    2014-02-01

    Rabies remains a major neglected global zoonosis. New vaccine strategies are needed for human rabies prophylaxis. A single intramuscular immunization with a moderate dose of an experimental chimpanzee adenovirus (Ad) vector serotype SAd-V24, also termed AdC68, expressing the rabies virus glycoprotein, resulted in sustained titers of rabies virus neutralizing antibodies and protection against a lethal rabies virus challenge infection in a non-human primate model. Taken together, these data demonstrate the safety, immunogenicity, and efficacy of the recombinant Ad-rabies vector for further consideration in human clinical trials. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Protection of Non-Human Primates against Rabies with an Adenovirus Recombinant Vaccine

    Science.gov (United States)

    Xiang, Z.Q.; Greenberg, L.; Ertl, H. C.; Rupprecht, C.E.

    2014-01-01

    Rabies remains a major neglected global zoonosis. New vaccine strategies are needed for human rabies prophylaxis. A single intramuscular immunization with a moderate dose of an experimental chimpanzee adenovirus (Ad) vector serotype SAd-V24, also termed AdC68, expressing the rabies virus glycoprotein, resulted in sustained titers of rabies virus neutralizing antibodies and protection against a lethal rabies virus challenge infection in a non-human primate model. Taken together, these data demonstrate the safety, immunogenicity, and efficacy of the recombinant Ad-rabies vector for further consideration in human clinical trials. PMID:24503087

  15. 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. © 2016 by The American Society of Hematology.

  16. The Fab Fragment of a Humanized Anti-Toll Like Receptor 4 (TLR4 Monoclonal Antibody Reduces the Lipopolysaccharide Response via TLR4 in Mouse Macrophage

    Directory of Open Access Journals (Sweden)

    Binggang Cai

    2015-10-01

    Full Text Available Lipopolysaccharides (LPS can induce acute inflammation, sepsis, or chronic inflammatory disorders through the Toll receptor 4 (TLR4 signaling pathway. The TLR4/MD2 (myeloid differentiation protein 2 complex plays a major role in the immune response to LPS. However, there is not a good method to suppress the immune response induced by LPS via this complex in macrophages. In this article, we aimed to evaluate the effects of humanized anti-TLR4 monoclonal antibodies on LPS-induced responses in mouse macrophages. The peritoneal macrophages of mice were incubated with anti-TLR4 monoclonal antibodies and stimulated with LPS. The expression levels of cytokines were analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assays. Additionally, activation of various signaling pathways was evaluated by Western blotting. The results showed that the humanized anti-TLR4 monoclonal antibody blocked the inflammatory cytokines expression at both the mRNA and protein level. We also found that the Fab fragment significantly inhibited the nuclear factor kappaB signaling pathway by reducing the phosphorylation of the inhibitor of kappaBalpha and decreasing the translocation of p65, resulting in the suppression of p38, extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase 1/2, and IFN-β regulatory factor 3 phosphorylation. Therefore, our study showed that this humanized anti-TLR4 monoclonal antibody could effectively protect against LPS-induced responses by blocking the TLR4 signaling pathway in mouse peritoneal macrophages.

  17. Recombination analysis and structure prediction show correlation between breakpoint clusters and RNA hairpins in the pol gene of human immunodeficiency virus type 1 unique recombinant forms

    DEFF Research Database (Denmark)

    Galli, Andrea; Lai, Alessia; Corvasce, Stefano

    2008-01-01

    Recombination is recognized as a primary force in human immunodeficiency virus type 1 (HIV-1) evolution, increasing viral diversity through reshuffling of genomic portions. The strand-switching activity of reverse transcriptase is required to complete HIV-1 replication and can occur randomly thro...

  18. Direct isolation of human BRCA2 gene by transformation-associated recombination in yeast

    Science.gov (United States)

    Larionov, Vladimir; Kouprina, Natalya; Solomon, Gregory; Barrett, J. Carl; Resnick, Michael A.

    1997-01-01

    Mutant forms of the BRCA2 gene contribute significantly to hereditary breast cancer. Isolation of the normal and mutant forms of the BRCA2 gene with its natural promoter would greatly facilitate analysis of the gene and its contribution to breast cancer. We have accomplished the direct isolation of the 90-kb gene from total human DNA by transformation-associated recombination in yeast using a small amount of 5′ and 3′ BRCA2 sequence information. Because the entire isolation procedure of a single chromosomal gene could be accomplished in approximately 2 weeks, the transformation-associated recombination cloning approach is readily applicable to studies of chromosome alterations and human genetic diseases. PMID:9207100

  19. Cross-reactive dengue human monoclonal antibody prevents severe pathologies and death from Zika virus infections

    OpenAIRE

    Kam, Yiu-Wing; Lee, Cheryl Yi-Pin; Teo, Teck-Hui; Howland, Shanshan W.; Amrun, Siti Naqiah; Lum, Fok-Moon; See, Peter; Kng, Nicholas Qing-Rong; Roland G. Huber; Xu, Mei-Hui; Tan, Heng-Liang; Choo, Andre; Maurer-Stroh, Sebastian; Ginhoux, Florent; Fink, Katja

    2017-01-01

    Zika virus (ZIKV) infections have been linked with neurological complications and congenital Zika syndrome. Given the high level of homology between ZIKV and the related flavivirus dengue virus (DENV), we investigated the level of cross-reactivity with ZIKV using a panel of DENV human mAbs. A majority of the mAbs showed binding to ZIKV virions, with several exhibiting neutralizing capacities against ZIKV in vitro. Three of the best ZIKV-neutralizing mAbs were found to recognize diverse epitop...

  20. Neurovirulence properties of recombinant vesicular stomatitis virus vectors in non-human primates

    OpenAIRE

    Johnson, J. Erik; Nasar, Farooq; Coleman, John W.; Price, Roger E; Javadian, Ali; Draper, Kenneth; Lee, Margaret; Reilly, Patricia A.; Clarke, David K.; Hendry, R. Michael; Udem, Stephen A.

    2007-01-01

    Although vesicular stomatitis virus (VSV) neurovirulence and pathogenicity in rodents have been well studied, little is known about VSV pathogenicity in non-human primates. To address this question, we measured VSV viremia, shedding, and neurovirulence in macaques. Following intranasal inoculation, macaques shed minimal recombinant VSV (rVSV) in nasal washes for one day post-inoculation; viremia was not detected. Following intranasal inoculation of macaques, wild type (wt) VSV, rVSV, and two ...

  1. Recombinant Glycoprotein Vaccines for Human Immunodeficiency Virus-Infected Children and Their Effects on Viral Quasispecies

    OpenAIRE

    Essajee, Shaffiq M; Yogev, Ram; Pollack, Henry; Greenhouse, Bryan; Krasinski, Keith; Borkowsky, William

    2002-01-01

    In individuals infected with human immunodeficiency virus type 1 (HIV-1), specific immunity is associated with a more diverse viral repertoire and slower disease progression. Attempts to enhance antiviral immunity with therapeutic vaccination have shown that recombinant glycoprotein (RGP) vaccines are safe, well tolerated, and immunogenic, but the effect of RGP vaccines on the viral repertoire is unknown. We evaluated diversification of the viral envelope in 12 HIV-infected children who recei...

  2. Value of recombinant human epidermal growth factor in corneal wound repair after corneal foreign body elimination

    OpenAIRE

    Hong-Jie Han

    2013-01-01

    AIM: To investigate the repair efficacy of recombinant human epidermal growth factor on corneal epithelium after corneal foreign body eliminating operation. METHODS: There were 102 patients with corneal foreign body(188 affected eyes)chosen for the study. All patients were divided into treatment group and control group according to the random number table. Both groups received corneal foreign body elimination by slit lamp. Postoperatively, the treatment group was given eye drops containing ep...

  3. Application effect of recombinant human epidermal growth factor derivative Eye drops in treatment of dry eye

    OpenAIRE

    Paerzhati·Tuerdi; Yan-Chun Wang

    2015-01-01

    AIM: To investigate the application effect of recombinant human epidermal growth factor derivative eye drops(Jinyinshu)in treatment of dry eye.METHODS:Sixty cases(87 eyes)of dry eye patients were randomly divided into control group and observation group, 42 eyes and 45 eyes respectively. The control group received Chondroitin sulfate eye drops treatment, and the observation group were used for treatment of Jinyinshu. The changes of clinical efficacy, correlation index(symptom score, BUT, S I ...

  4. Expression of human β-defensin-1 in recombinant Escherichia coli ...

    African Journals Online (AJOL)

    Escherichia coli BL21(DE3) was transformed with a pHCD1 plasmid harboring the human β-defensin-1 (hBD1) gene fused in frame behind a disulfide bond isomerase (DsbC), a His-tag, and an enterokinase cleavage site. After induction, the DsbC-hBD1 was expressed as a ~36 kDa soluble fusion protein in recombinant E.

  5. Engineering the oxygen sensing regulation results in an enhanced recombinant human hemoglobin production by Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Martinez Ruiz, José Luis; Liu, Lifang; Petranovic, Dina

    2015-01-01

    the generation of a set of plasmids to produce functional human hemoglobin in Saccharomyces cerevisiae, with final titers of active hemoglobin exceeding 4% of the total cell protein. In this study, we propose a strategy for further engineering S. cerevisiae by altering the oxygen sensing pathway by deleting...... the transcription factor HAP1, which resulted in an increase of the final recombinant active hemoglobin titer exceeding 7% of the total cellular protein....

  6. Refined genetic maps reveal sexual dimorphism in human meiotic recombination at multiple scales

    Science.gov (United States)

    Bhérer, Claude; Campbell, Christopher L.; Auton, Adam

    2017-04-01

    In humans, males have lower recombination rates than females over the majority of the genome, but the opposite is usually true near the telomeres. These broad-scale differences have been known for decades, yet little is known about differences at the fine scale. By combining data sets, we have collected recombination events from over 100,000 meioses and have constructed sex-specific genetic maps at a previously unachievable resolution. Here we show that, although a substantial fraction of the genome shows some degree of sexually dimorphic recombination, the vast majority of hotspots are shared between the sexes, with only a small number of putative sex-specific hotspots. Wavelet analysis indicates that most of the differences can be attributed to the fine scale, and that variation in rate between the sexes can mostly be explained by differences in hotspot magnitude, rather than location. Nonetheless, known recombination-associated genomic features, such as THE1B repeat elements, show systematic differences between the sexes.

  7. A performance evaluation of a novel human recombinant tissue factor prothrombin time reagent (Revohem™ PT).

    Science.gov (United States)

    Gardiner, C; Kohama, K; Patel, I; Lane, P; Dwyer, S; Machin, S J; Mackie, I J

    2017-10-01

    A new prothrombin time reagent (Revohem™ PT) based on recombinant human tissue factor produced by the silkworm-baculovirus expression system was tested. The aim of this study was to compare the performance of the new PT reagent with two widely used routine PT reagents. All testing was performed on a Sysmex CS-5100 coagulometer. Revohem™ PT was tested for imprecision and stability using normal and abnormal lyophilized commercial control plasmas. Comparability was assessed with two widely used reagents: one containing recombinant human tissue factor (Reagent A) and the other a human placental thromboplastin (Reagent B) using a wide range of normal and abnormal plasmas and analyser-specific ISI values. Excellent between-day imprecision was obtained for Revohem™ PT (CV <1.0%) and acceptable open-vial on-board stability over 7 days. There was good agreement between methods in samples from patients with liver disease and patients receiving warfarin and no significant differences between methods with increasing INR values. Both recombinant reagents suffered less interference from lupus anticoagulant than the placental thromboplastin. Revohem™ PT had similar sensitivity to reagents A and B for FII, V, VII and X deficiency and demonstrated dose responsiveness to dabigatran, apixaban and rivaroxaban with steeper response curves than the comparison reagents. Revohem™ PT showed comparable or improved performance relative to two widely used reagents and is suitable for use in warfarin control, detection of inherited factor II, V, VII and X deficiency and assessment of liver disease coagulopathy. © 2017 John Wiley & Sons Ltd.

  8. Amphipathic variable region heavy chain peptides derived from monoclonal human Wegener's anti-PR3 antibodies stimulate lymphocytes from patients with Wegener's granulomatosis and microscopic polyangiitis

    Science.gov (United States)

    Peen, E; Malone, C; Myers, C; Williams, R C; Peck, A B; Csernok, E; Gross, W L; Staud, R

    2001-01-01

    Amphipathic variable-region heavy chain 11-mer peptides from monoclonal human IgM antiproteinase-3 antibodies were studied for peripheral blood lymphocyte stimulation in 21 patients with Wegener's granulomatosis (WG) or microscopic polyangiitis (MPA), connective tissue disease controls and normal control subjects. Positive T-cell activation was observed in most experiments with WG patients' lymphocytes using amphipathic VH-region peptides from four different human monoclonal anti-PR3 antibodies. Control peptides of the same length but without amphipathic characteristics along with other amphipathic peptides not derived from monoclonal anti-PR3 sequence were employed as controls. No significant lymphocyte stimulation was observed with normal controls, but positive stimulation with amphipathic VH peptides was also recorded in other connective tissue disease controls mainly patients with rheumatoid arthritis. Amphipathic peptides not derived from anti-PR3 sequence did not stimulate WG lymphocytes. Our findings indicate that lymphocyte reactivity as an element of cell-mediated immunity may be activated by amphipathic VH-region amino acid sequences of autoantibodies which are themselves associated with diseases such as WG. PMID:11529926

  9. Characterisation of new monoclonal antibodies reacting with prions from both human and animal brain tissues

    DEFF Research Database (Denmark)

    Cordes, H.; Bergstrom, A.L.; Ohm, J.

    2008-01-01

    Post-mortem diagnosis of transmissible spongiform encephalopathies (prion diseases) is primarily based on the detection of a protease resistant, misfolded disease associated isoform (PrP(Sc)) of the prion protein (PrP(C)) on neuronal cells. These methods depend on antibodies directed against Pr......-type mice and used for western blotting and immunohistochemistry to detect several types of human prion-disease associated PrP(Sc), including sporadic Creutzfeldt-Jakob Disease (CJD) (subtypes MM1 and VV2), familial CJD and Gerstmann-Straussler-Scheinker (GSS) disease PrP(Sc) as well as PrP(Sc) of bovine...... spongiform encephalopathy (bovine brain), scrapie (ovine brain) and experimental scrapie in hamster and in mice. The antibodies were also used for PET-blotting in which PrP(Sc) blotted from brain tissue sections onto a nitrocellulose membrane is visualized with antibodies after protease and denaturant...

  10. Cross-reactivity of human monoclonal antibodies generated with peripheral blood lymphocytes from dengue patients with Japanese encephalitis virus

    Directory of Open Access Journals (Sweden)

    Pipattanaboon C

    2013-08-01

    Full Text Available Chonlatip Pipattanaboon,1,3,8,* Tadahiro Sasaki,2,8,* Mitsuhiro Nishimura,2,8 Chayanee Setthapramote,1,8 Pannamthip Pitaksajjakul,1,4,8 Pornsawan Leaungwutiwong,1,3,8 Kriengsak Limkittikul,5,8 Orapim Puiprom,6 Mikiko Sasayama,6 Panjaporn Chaichana,6 Tamaki Okabayashi,6 Takeshi Kurosu,2,8 Ken-ichiro Ono,7,8 Pongrama Ramasoota,1,4,8 Kazuyoshi Ikuta2,8 1Center of Excellence for Antibody Research, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; 2Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan; 3Department of Microbiology and Immunology, 4Department of Social and Environmental Medicine, 5Department of Tropical Pediatrics, Faculty of Tropical Medicine, Mahidol University, 6Mahidol-Osaka Center for Infectious Diseases, Bangkok, Thailand; 7Medical and Biological Laboratories Corporation Ltd, Nagano, Japan; 8JST/JICA, Science and Technology Research Partnership for Sustainable Development, Tokyo, Japan *These authors made an equal contribution to this study Background: Hybridomas that produce human monoclonal antibodies (HuMAbs against Dengue virus (DV had been prepared previously using peripheral blood lymphocytes from patients with DV during the acute and convalescent phases of a secondary infection. Anti-DV envelope glycoprotein (E 99 clones, anti-DV premembrane protein (prM 8 clones, and anti-DV nonstructural protein 1 (NS1 4 clones were derived from four acute-phase patients, and anti-DV E 2 clones, anti-DV prM 2 clones, and anti-DV NS1 8 clones were derived from five convalescent-phase patients. Methods and results: In the present study, we examined whether these clones cross-reacted with Japanese encephalitis virus (JEV, which belongs to the same virus family. Forty-six of the above-described 99 (46/99 anti-E, 0/8 anti-prM, and 2/4 anti-NS1 HuMAbs from acute-phase, and 0/2 anti-E, 0/2 anti-prM, and 5/8 anti-NS1 HuMAbs from convalescent-phase showed neutralizing activity against

  11. Regulatory approval and a first-in-human phase I clinical trial of a monoclonal antibody produced in transgenic tobacco plants.

    Science.gov (United States)

    Ma, Julian K-C; Drossard, Jürgen; Lewis, David; Altmann, Friedrich; Boyle, Julia; Christou, Paul; Cole, Tom; Dale, Philip; van Dolleweerd, Craig J; Isitt, Valerie; Katinger, Dietmar; Lobedan, Martin; Mertens, Hubert; Paul, Mathew J; Rademacher, Thomas; Sack, Markus; Hundleby, Penelope A C; Stiegler, Gabriela; Stoger, Eva; Twyman, Richard M; Vcelar, Brigitta; Fischer, Rainer

    2015-10-01

    Although plant biotechnology has been widely investigated for the production of clinical-grade monoclonal antibodies, no antibody products derived from transgenic plants have yet been approved by pharmaceutical regulators for clinical testing. In the Pharma-Planta project, the HIV-neutralizing human monoclonal antibody 2G12 was expressed in transgenic tobacco (Nicotiana tabacum). The scientific, technical and regulatory demands of good manufacturing practice (GMP) were addressed by comprehensive molecular characterization of the transgene locus, confirmation of genetic and phenotypic stability over several generations of transgenic plants, and by establishing standard operating procedures for the creation of a master seed bank, plant cultivation, harvest, initial processing, downstream processing and purification. The project developed specifications for the plant-derived antibody (P2G12) as an active pharmaceutical ingredient (API) based on (i) the guidelines for the manufacture of monoclonal antibodies in cell culture systems; (ii) the draft European Medicines Agency Points to Consider document on quality requirements for APIs produced in transgenic plants; and (iii) de novo guidelines developed with European national regulators. From the resulting process, a GMP manufacturing authorization was issued by the competent authority in Germany for transgenic plant-derived monoclonal antibodies for use in a phase I clinical evaluation. Following preclinical evaluation and ethical approval, a clinical trial application was accepted by the UK national pharmaceutical regulator. A first-in-human, double-blind, placebo-controlled, randomized, dose-escalation phase I safety study of a single vaginal administration of P2G12 was carried out in healthy female subjects. The successful completion of the clinical trial marks a significant milestone in the commercial development of plant-derived pharmaceutical proteins. © 2015 Society for Experimental Biology, Association of

  12. A broadly neutralizing human monoclonal antibody is effective against H7N9.

    Science.gov (United States)

    Tharakaraman, Kannan; Subramanian, Vidya; Viswanathan, Karthik; Sloan, Susan; Yen, Hui-Ling; Barnard, Dale L; Leung, Y H Connie; Szretter, Kristy J; Koch, Tyree J; Delaney, James C; Babcock, Gregory J; Wogan, Gerald N; Sasisekharan, Ram; Shriver, Zachary

    2015-09-01

    Emerging strains of influenza represent a significant public health threat with potential pandemic consequences. Of particular concern are the recently emerged H7N9 strains which cause pneumonia with acute respiratory distress syndrome. Estimates are that nearly 80% of hospitalized patients with H7N9 have received intensive care unit support. VIS410, a human antibody, targets a unique conserved epitope on influenza A. We evaluated the efficacy of VIS410 for neutralization of group 2 influenza strains, including H3N2 and H7N9 strains in vitro and in vivo. VIS410, administered at 50 mg/kg, protected DBA mice infected with A/Anhui/2013 (H7N9), resulting in significant survival benefit upon single-dose (-24 h) or double-dose (-12 h, +48 h) administration (P cytokine responses for nine of the 11 cytokines measured. Based on these results, we find that VIS410 may be effective either as monotherapy or combined with antivirals in treating H7N9 disease, as well as disease from other influenza strains.

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

    Directory of Open Access Journals (Sweden)

    Sharad P Adekar

    2008-08-01

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

  14. Monoclonal Antibodies Specific for Hippurate Hydrolase of Campylobacter jejuni

    OpenAIRE

    Steele, Marina; Gyles, Carlton; Chan, Voon Loong; Odumeru, Joseph

    2002-01-01

    Eleven monoclonal antibodies raised against recombinant Campylobacter jejuni hippurate hydrolase were tested for binding to lysates from 19 C. jejuni strains, 12 other Campylobacter strains, and 21 non-Campylobacter strains. Several monoclonal antibodies bound to C. jejuni but not to other Campylobacter species and may be useful in a species-specific immunoassay.

  15. Cloning and expression of recombinant human platelet-derived growth factor-BB in Pichia Pink.

    Science.gov (United States)

    Babavalian, H; Latifi, A M; Shokrgozar, M A; Bonakdar, S; Tebyanian, H; Shakeri, F

    2016-07-31

    The PDGF-BB plays a key role in several pathogenesis diseases and it is believed to be an important mediator for wound healing. The recombinant human PDGF-BB is safe and effective to stimulate the healing of chronic, full thickness and lower extremity diabetic neurotrophic ulcers. In the present study, we attempted to produce a PDGF-BB growth factor and also, evaluate its functionality in cell proliferation in yeast host Pichia pink. Pichia pink yeast was used as a host for evaluation of the rhPDGF-BB expression. The coding sequence of PDGF-BB protein was synthesized after optimization and packed into the pGEM. Recombinant proteins were produced and purified. The construct of pPinkα-HC-pdgf was confirmed by sequence, the PDGF-BB protein was expressed and purified with using a nickel affinity chromatography column and then characterized by SDS-PAGE electrophoresis. The biological activity of PDGF-BB was estimated with using human fibroblast cell line. The measurement of protein concentration was determined by Bradford and human PDGF-BB ELISA kit. Purified rhPDGF-BB showed similar biological activity (as the standard PDGF-BB) and suggested that the recombinant protein has a successful protein expression (as well as considerable biological activity in P. pink host). The exact amount of recombinant PDGF-BB concentrations were measured by specific ELISA test which it was about 30 μg/ml. Our study suggested that efficiency of biological activity of PDGF-BB protein may be related to its conformational similarity with standard type and also, it practically may be important in wound healing and tissue regeneration.

  16. Recombination rates and genomic shuffling in human and chimpanzee--a new twist in the chromosomal speciation theory.

    Science.gov (United States)

    Farré, Marta; Micheletti, Diego; Ruiz-Herrera, Aurora

    2013-04-01

    A long-standing question in evolutionary biology concerns the effect of recombination in shaping the genomic architecture of organisms and, in particular, how this impacts the speciation process. Despite efforts employed in the last decade, the role of chromosomal reorganizations in the human-chimpanzee speciation process remains unresolved. Through whole-genome comparisons, we have analyzed the genome-wide impact of genomic shuffling in the distribution of human recombination rates during the human-chimpanzee speciation process. We have constructed a highly refined map of the reorganizations and evolutionary breakpoint regions in the human and chimpanzee genomes based on orthologous genes and genome sequence alignments. The analysis of the most recent human and chimpanzee recombination maps inferred from genome-wide single-nucleotide polymorphism data revealed that the standardized recombination rate was significantly lower in rearranged than in collinear chromosomes. In fact, rearranged chromosomes presented significantly lower recombination rates than chromosomes that have been maintained since the ancestor of great apes, and this was related with the lineage in which they become fixed. Importantly, inverted regions had lower recombination rates than collinear and noninverted regions, independently of the effect of centromeres. Our observations have implications for the chromosomal speciation theory, providing new evidences for the contribution of inversions in suppressing recombination in mammals.

  17. In Vivo Efficacy of a Cocktail of Human Monoclonal Antibodies (CL184 Against Diverse North American Bat Rabies Virus Variants

    Directory of Open Access Journals (Sweden)

    Richard Franka

    2017-09-01

    Full Text Available Following rabies virus (RABV exposure, a combination of thorough wound washing, multiple-dose vaccine administration and the local infiltration of rabies immune globulin (RIG are essential components of modern post-exposure prophylaxis (PEP. Although modern cell-culture-based rabies vaccines are increasingly used in many countries, RIG is much less available. The prohibitive cost of polyclonal serum RIG products has prompted a search for alternatives and design of anti-RABV monoclonal antibodies (MAbs that can be manufactured on a large scale with a consistent potency and lower production costs. Robust in vitro neutralization activity has been demonstrated for the CL184 MAb cocktail, a 1:1 protein mixture of two human anti-RABV MAbs (CR57/CR4098, against a large panel of RABV isolates. In this study, we used a hamster model to evaluate the efficacy of experimental PEP against a lethal challenge. Various doses of CL184 and commercial rabies vaccine were assessed for the ability to protect against lethal infection with representatives of four distinct bat RABV lineages of public health relevance: silver-haired bat (Ln RABV; western canyon bat (Ph RABV; big brown bat (Ef-w1 RABV and Mexican free-tailed bat RABV (Tb RABV. 42–100% of animals survived bat RABV infection when CL184 (in combination with the vaccine was administered. A dose-response relationship was observed with decreasing doses of CL184 resulting in increasing mortality. Importantly, CL184 was highly effective in neutralizing and clearing Ph RABV in vivo, even though CR4098 does not neutralize this virus in vitro. By comparison, 19–95% survivorship was observed if human RIG (20 IU/kg and vaccine were used following challenge with different bat viruses. Based on our results, CL184 represents an efficacious alternative for RIG. Both large-scale and lower cost production could ensure better availability and affordability of this critical life-saving biologic in rabies enzootic

  18. Characterization of ABT-806, a Humanized Tumor-Specific Anti-EGFR Monoclonal Antibody.

    Science.gov (United States)

    Reilly, Edward B; Phillips, Andrew C; Buchanan, Fritz G; Kingsbury, Gillian; Zhang, Yumin; Meulbroek, Jonathan A; Cole, Todd B; DeVries, Peter J; Falls, Hugh D; Beam, Christine; Gu, Jinming; Digiammarino, Enrico L; Palma, Joann P; Donawho, Cherrie K; Goodwin, Neal C; Scott, Andrew M

    2015-05-01

    Despite clinical efficacy, current approved agents targeting EGFR are associated with on-target toxicities as a consequence of disrupting normal EGFR function. MAb 806 is a novel EGFR antibody that selectively targets a tumor-selective epitope suggesting that a mAb 806-based therapeutic would retain antitumor activity without the on-target toxicities associated with EGFR inhibition. To enable clinical development, a humanized variant of mAb 806 designated ABT-806 was generated and is currently in phase 1 trials. We describe the characterization of binding and functional properties of ABT-806 compared with the clinically validated anti-EGFR antibody cetuximab. ABT-806 binds the mutant EGFRvIII with high affinity and, relative to cetuximab, exhibits increased potency against glioblastoma multiforme cell line and patient-derived xenografts expressing this form of the receptor. ABT-806 also inhibits the growth of squamous cell carcinoma xenograft models expressing high levels of wild-type EGFR, associated with inhibition of EGFR signaling, although higher doses of ABT-806 than cetuximab are required for similar activity. ABT-806 enhances in vivo potency of standard-of-care therapies used to treat glioblastoma multiforme and head and neck squamous cell carcinoma. An indium-labeled version of ABT-806, [(111)In]-ABT-806, used to investigate the relationship between dose and receptor occupancy, revealed greater receptor occupancy at lowers doses in an EGFRvIII-expressing model and significant uptake in an orthotopic model. Collectively, these results suggest that ABT-806 may have antitumor activity superior to cetuximab in EGFRvIII-expressing tumors, and similar activity to cetuximab in tumors highly overexpressing wild-type EGFR with reduced toxicity. ©2015 American Association for Cancer Research.

  19. Cross-reactive dengue human monoclonal antibody prevents severe pathologies and death from Zika virus infections

    Science.gov (United States)

    Kam, Yiu-Wing; Lee, Cheryl Yi-Pin; Teo, Teck-Hui; Howland, Shanshan W.; Amrun, Siti Naqiah; See, Peter; Kng, Nicholas Qing-Rong; Huber, Roland G.; Xu, Mei-Hui; Tan, Heng-Liang; Choo, Andre; Ginhoux, Florent; Fink, Katja; Wang, Cheng-I; Ng, Lisa F.P.

    2017-01-01

    Zika virus (ZIKV) infections have been linked with neurological complications and congenital Zika syndrome. Given the high level of homology between ZIKV and the related flavivirus dengue virus (DENV), we investigated the level of cross-reactivity with ZIKV using a panel of DENV human mAbs. A majority of the mAbs showed binding to ZIKV virions, with several exhibiting neutralizing capacities against ZIKV in vitro. Three of the best ZIKV-neutralizing mAbs were found to recognize diverse epitopes on the envelope (E) glycoprotein: the highly conserved fusion-loop peptide, a conformation-specific epitope on the E monomer, and a quaternary epitope on the virion surface. The most potent ZIKV-neutralizing mAb (SIgN-3C) was assessed in 2 type I interferon receptor–deficient (IFNAR–/–) mouse models of ZIKV infection. Treatment of adult nonpregnant mice with SIgN-3C rescued mice from virus-induced weight loss and mortality. The SIgN-3C variant with Leu-to-Ala mutations in the Fc region (SIgN-3C-LALA) did not induce antibody-dependent enhancement (ADE) in vitro but provided similar levels of protection in vivo. In pregnant ZIKV-infected IFNAR–/– mice, treatment with SIgN-3C or SIgN-3C-LALA significantly reduced viral load in the fetal organs and placenta and abrogated virus-induced fetal growth retardation. Therefore, SIgN-3C-LALA holds promise as a ZIKV prophylactic and therapeutic agent. PMID:28422757

  20. Cross-reactive dengue human monoclonal antibody prevents severe pathologies and death from Zika virus infections.

    Science.gov (United States)

    Kam, Yiu-Wing; Lee, Cheryl Yi-Pin; Teo, Teck-Hui; Howland, Shanshan W; Amrun, Siti Naqiah; Lum, Fok-Moon; See, Peter; Kng, Nicholas Qing-Rong; Huber, Roland G; Xu, Mei-Hui; Tan, Heng-Liang; Choo, Andre; Maurer-Stroh, Sebastian; Ginhoux, Florent; Fink, Katja; Wang, Cheng-I; Ng, Lisa F P; Rénia, Laurent

    2017-04-20

    Zika virus (ZIKV) infections have been linked with neurological complications and congenital Zika syndrome. Given the high level of homology between ZIKV and the related flavivirus dengue virus (DENV), we investigated the level of cross-reactivity with ZIKV using a panel of DENV human mAbs. A majority of the mAbs showed binding to ZIKV virions, with several exhibiting neutralizing capacities against ZIKV in vitro. Three of the best ZIKV-neutralizing mAbs were found to recognize diverse epitopes on the envelope (E) glycoprotein: the highly conserved fusion-loop peptide, a conformation-specific epitope on the E monomer, and a quaternary epitope on the virion surface. The most potent ZIKV-neutralizing mAb (SIgN-3C) was assessed in 2 type I interferon receptor-deficient (IFNAR-/-) mouse models of ZIKV infection. Treatment of adult nonpregnant mice with SIgN-3C rescued mice from virus-induced weight loss and mortality. The SIgN-3C variant with Leu-to-Ala mutations in the Fc region (SIgN-3C-LALA) did not induce antibody-dependent enhancement (ADE) in vitro but provided similar levels of protection in vivo. In pregnant ZIKV-infected IFNAR-/- mice, treatment with SIgN-3C or SIgN-3C-LALA significantly reduced viral load in the fetal organs and placenta and abrogated virus-induced fetal growth retardation. Therefore, SIgN-3C-LALA holds promise as a ZIKV prophylactic and therapeutic agent.

  1. Biotechnology and genetic engineering in the new drug development. Part II. Monoclonal antibodies, modern vaccines and gene therapy.

    Science.gov (United States)

    Stryjewska, Agnieszka; Kiepura, Katarzyna; Librowski, Tadeusz; Lochyński, Stanisław

    2013-01-01

    Monoclonal antibodies, modern vaccines and gene therapy have become a major field in modern biotechnology, especially in the area of human health and fascinating developments achieved in the past decades are impressive examples of an interdisciplinary interplay between medicine, biology and engineering. Among the classical products from cells one can find viral vaccines, monoclonal antibodies, and interferons, as well as recombinant therapeutic proteins. Gene therapy opens up challenging new areas. In this review, a definitions of these processes are given and fields of application and products, as well as the future prospects, are discussed.

  2. Accumulation of functional recombinant human coagulation factor IX in transgenic soybean seeds.

    Science.gov (United States)

    Cunha, Nicolau B; Murad, André M; Ramos, Gustavo L; Maranhão, Andréia Q; Brígido, Marcelo M; Araújo, Ana Cláudia G; Lacorte, Cristiano; Aragão, Francisco J L; Covas, Dimas T; Fontes, Aparecida M; Souza, Gustavo H M F; Vianna, Giovanni R; Rech, Elíbio L

    2011-08-01

    The seed-based production of recombinant proteins is an efficient strategy to achieve the accumulation, correct folding, and increased stability of these recombinant proteins. Among potential plant molecular farming systems, soybean [Glycine max (L.) Merrill] is a viable option for the production of recombinant proteins due to its high protein content, known regulatory sequences, efficient gene transfer protocols, and a scalable production system under greenhouse conditions. We report here the expression and stable accumulation of human coagulation factor IX (hFIX) in transgenic soybean seeds. A biolistic process was utilised to co-introduce a plasmid carrying the hFIX gene under the transcriptional control of the α' subunit of a β-conglycinin seed-specific promoter and an α-Coixin signal peptide in soybean embryonic axes from mature seeds. The 56-kDa hFIX protein was expressed in the transgenic seeds at levels of up to 0.23% (0.8 g kg(-1) seed) of the total soluble seed protein as determined by an enzyme-linked immunosorbent assay (ELISA) and western blot. Ultrastructural immunocytochemistry assays indicated that the recombinant hFIX in seed cotyledonary cells was efficiently directed to protein storage vacuoles. Mass spectrometry characterisation confirmed the presence of the hFIX recombinant protein sequence. Protein extracts from transgenic seeds showed a blood-clotting activity of up to 1.4% of normal plasma. Our results demonstrate the correct processing and stable accumulation of functional hFIX in soybean seeds stored for 6 years under room temperature conditions (22 ± 2°C).

  3. Virulence evolution of the human pathogen Neisseria meningitidis by recombination in the core and accessory genome.

    Directory of Open Access Journals (Sweden)

    Biju Joseph

    Full Text Available BACKGROUND: Neisseria meningitidis is a naturally transformable, facultative pathogen colonizing the human nasopharynx. Here, we analyze on a genome-wide level the impact of recombination on gene-complement diversity and virulence evolution in N. meningitidis. We combined comparative genome hybridization using microarrays (mCGH and multilocus sequence typing (MLST of 29 meningococcal isolates with computational comparison of a subset of seven meningococcal genome sequences. PRINCIPAL FINDINGS: We found that lateral gene transfer of minimal mobile elements as well as prophages are major forces shaping meningococcal population structure. Extensive gene content comparison revealed novel associations of virulence with genetic elements besides the recently discovered meningococcal disease associated (MDA island. In particular, we identified an association of virulence with a recently described canonical genomic island termed IHT-E and a differential distribution of genes encoding RTX toxin- and two-partner secretion systems among hyperinvasive and non-hyperinvasive lineages. By computationally screening also the core genome for signs of recombination, we provided evidence that about 40% of the meningococcal core genes are affected by recombination primarily within metabolic genes as well as genes involved in DNA replication and repair. By comparison with the results of previous mCGH studies, our data indicated that genetic structuring as revealed by mCGH is stable over time and highly similar for isolates from different geographic origins. CONCLUSIONS: Recombination comprising lateral transfer of entire genes as well as homologous intragenic recombination has a profound impact on meningococcal population structure and genome composition. Our data support the hypothesis that meningococcal virulence is polygenic in nature and that differences in metabolism might contribute to virulence.

  4. INACTIVITY OF RECOMBINANT ELA2B PROVIDES A NEW EXAMPLE OF EVOLUTIONARY ELASTASE SILENCING IN HUMANS

    OpenAIRE

    Szepessy, Edit; Sahin-Tóth, Miklós

    2005-01-01

    BACKGROUND. The archetypal mammalian elastase (ELA1) is not expressed in the human pancreas, because evolutionary mutations suppressed transcription of the ELA1 gene. AIMS. In this study we tested the theory that the unique duplication of the ELA2 gene in humans might compensate for the loss of ELA1. METHODS. Recombinant ELA2A and ELA2B were expressed in Escherichia coli, and their activity was tested on Glt-Ala-Ala-Pro-Leu-p-nitroanilide, DQ elastin and bovine milk protein. RESULTS. Surprisi...

  5. Innervation of Tissue-Engineered Recombinant Human Collagen-Based Corneal Substitutes: A Comparative In Vivo Confocal Microscopy Study

    National Research Council Canada - National Science Library

    Lagali, Neil; Griffith, May; Fagerholm, Per; Merrett, Kimberley; Huynh, Melissa; Munger, Rejean

    2008-01-01

    ...; and the 3 Department of Ophthalmology, Linköping University Hospital, Linköping, Sweden. METHODS . Pigs received a corneal allograft or a substitute made of either recombinant human type-I or -III collagen...

  6. Recombinant human activated protein C in the treatment of acute respiratory distress syndrome : A randomized clinical trial

    NARCIS (Netherlands)

    A.D. Cornet (Alexander); A.B.J. Groeneveld (Johan); J.J. Hofstra (Jorrit Jan); A.P.J. Vlaar (Alexander); S. Tuinman (Sietske); A. van Lingen (Arthur); M. Levi (Michael); A.R.J. Girbes (Armand); M.J. Schultz (Marcus); A. Beishuizen (Auke)

    2014-01-01

    textabstractRationale: Pulmonary coagulopathy may play a pathogenetic role in acute respiratory distress syndrome (ARDS), by contributing to alveolocapillary inflammation and increased permeability. Recombinant human activated protein C (rh-APC) may inhibit this process and thereby improve patient

  7. Engineering the oxygen sensing regulation results in an enhanced recombinant human hemoglobin production by Saccharomyces cerevisiae.

    Science.gov (United States)

    Martínez, José L; Liu, Lifang; Petranovic, Dina; Nielsen, Jens

    2015-01-01

    Efficient production of appropriate oxygen carriers for transfusions (blood substitutes or artificial blood) has been pursued for many decades, and to date several strategies have been used, from synthetic polymers to cell-free hemoglobin carriers. The recent advances in the field of metabolic engineering also allowed the generation of different genetically modified organisms for the production of recombinant human hemoglobin. Several studies have showed very promising results using the bacterium Escherichia coli as a production platform, reporting hemoglobin titers above 5% of the total cell protein content. However, there are still certain limitations regarding the protein stability and functionality of the recombinant hemoglobin produced in bacterial systems. In order to overcome these limitations, yeast systems have been proposed as the eukaryal alternative. We recently reported the generation of a set of plasmids to produce functional human hemoglobin in Saccharomyces cerevisiae, with final titers of active hemoglobin exceeding 4% of the total cell protein. In this study, we propose a strategy for further engineering S. cerevisiae by altering the oxygen sensing pathway by deleting the transcription factor HAP1, which resulted in an increase of the final recombinant active hemoglobin titer exceeding 7% of the total cellular protein. © 2014 Wiley Periodicals, Inc.

  8. Isolation and characterization of a monoclonal anti-protein kinase CK2 beta-subunit antibody of the IgG class for the direct detection of CK2 beta-subunit in tissue cultures of various mammalian species and human tumors

    DEFF Research Database (Denmark)

    Nastainczyk, W; Schmidt-Spaniol, I; Boldyreff, B

    1995-01-01

    A murine monoclonal anti-protein kinase CK2 beta antibody was isolated and characterized. The antibody detects 1 pmol of purified recombinant CK2 beta-subunit after analysis on SDS-PAGE. Alternatively undenatured CK2 beta-subunit was detected by an ELISA assay either as recombinant CK2 beta-subun...

  9. Cd(II) and As(III) bioaccumulation by recombinant Escherichia coli expressing oligomeric human metallothioneins.

    Science.gov (United States)

    Ma, Yao; Lin, Jianqun; Zhang, Chengjia; Ren, Yilin; Lin, Jianqiang

    2011-01-30

    Metallothioneins (MTs) are a family of metal binding proteins. Recombinant Escherichia coli expressing the human MT (hMT-1A) gene was constructed for bioaccumulation of heavy metals. In order to increase protein stability, the glutathione S-transferase (GST) gene was fused with the hMT-1A gene and coexpressed. In order to increase MT expression efficiency and metal binding capacity, two, three or four hMT-1A genes were integrated in series and overexpressed in E. coli. The recombinant E. coli expressing the GST fused trimeric hMT-1A protein exhibited the highest Cd(II) and As(III) bioaccumulation ability, 6.36 mg Cd/g dry cells and 7.59 mg As/g dry cells, respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Recombinant expression in E. coli of human FGFR2 with its transmembrane and extracellular domains

    Directory of Open Access Journals (Sweden)

    Adam Bajinting

    2017-06-01

    Full Text Available Fibroblast growth factor receptors (FGFRs are a family of receptor tyrosine kinases containing three domains: an extracellular receptor domain, a single transmembrane helix, and an intracellular tyrosine kinase domain. FGFRs are activated by fibroblast growth factors (FGFs as part of complex signal transduction cascades regulating angiogenesis, skeletal formation, cell differentiation, proliferation, cell survival, and cancer. We have developed the first recombinant expression system in E. coli to produce a construct of human FGFR2 containing its transmembrane and extracellular receptor domains. We demonstrate that the expressed construct is functional in binding heparin and dimerizing. Size exclusion chromatography demonstrates that the purified FGFR2 does not form a complex with FGF1 or adopts an inactive dimer conformation. Progress towards the successful recombinant production of intact FGFRs will facilitate further biochemical experiments and structure determination that will provide insight into how extracellular FGF binding activates intracellular kinase activity.

  11. Innervation of tissue-engineered recombinant human collagen-based corneal substitutes : A comparative in vivo confocal microscopy study

    OpenAIRE

    Lagali, Neil; Griffith, May; Fagerholm, Per; Merrett, Kimberley; Huynh, Melissa; Munger, Rejean

    2008-01-01

    PURPOSE. To compare reinnervation in recombinant human collagen-based corneal substitutes with allografts during a 1-year postimplantation follow-up period in pigs. A retrospective comparison to innervation in porcine collagen-based biosynthetic grafts was also performed. METHODS. Pigs received a corneal allograft or a substitute made of either recombinant human type-I or -III collagen. In vivo confocal microscopic examination of the central cornea of surgical and untouched control eyes befor...

  12. The Effect of Recombinant Human MG53 Protein on Tourniquet-induced Ischemia Reperfusion Injury in Rat Muscle

    Science.gov (United States)

    2014-06-01

    The effect of recombinant human MG53 protein on tourniquet- induced ischemia reperfusion injury in rat muscle Benjamin T. Corona , Ph.D.1, Koyal Garg...family protein , has been shown to be essential for regulating membrane repair and has been shown to be protective against cardiac I-R and various forms...effect of recombinant human MG53 protein on tourniquet-induced ischemia reperfusion injury in rat muscle. 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  13. Inhibition of Apoptosis Stages of Human Blood Lymphocytes after Exposure to Carbon Monoxide in the Presence of Recombinant Interleukin-2.

    Science.gov (United States)

    Artyukhov, V G; Tyunina, O I

    2017-01-01

    We studied the effect of carbon monoxide (60-, 75-, and 90-min exposure) on the expression of antiapoptotic proteins (survivin and Bcl-2) in human blood lymphocytes in the presence of recombinant IL-2 in an apoptosis-inducing dose (0.1 ng/ml). Incubation of cells in atmosphere with carbon monoxide in the presence of recombinant IL-2 was accompanied by accumulation of Bcl-2 protein with simultaneous decrease of survivin content. It was concluded that carbon monoxide plays a role in the dysregulation of apoptosis of human blood lymphocytes Bcl-2 (i.e. CO inhibits the proapoptotic effect of recombinant IL-2).

  14. Antitumour effects of single or combined monoclonal antibodies directed against membrane antigens expressed by human B cells leukaemia

    Directory of Open Access Journals (Sweden)

    Kosinski Marek

    2011-04-01

    Full Text Available Abstract Background The increasing availability of different monoclonal antibodies (mAbs opens the way to more specific biologic therapy of cancer patients. However, despite the significant success of therapy in breast and ovarian carcinomas with anti-HER2 mAbs as well as in non-Hodkin B cell lymphomas with anti-CD20 mAbs, certain B cell malignancies such as B chronic lymphocytic leukaemia (B-CLL respond poorly to anti-CD20 mAb, due to the low surface expression of this molecule. Thus, new mAbs adapted to each types of tumour will help to develop personalised mAb treatment. To this aim, we analyse the biological and therapeutic properties of three mAbs directed against the CD5, CD71 or HLA-DR molecules highly expressed on B-CLL cells. Results The three mAbs, after purification and radiolabelling demonstrated high and specific binding capacity to various human leukaemia target cells. Further in vitro analysis showed that mAb anti-CD5 induced neither growth inhibition nor apoptosis, mAb anti-CD71 induced proliferation inhibition with no early sign of cell death and mAb anti-HLA-DR induced specific cell aggregation, but without evidence of apoptosis. All three mAbs induced various degrees of ADCC by NK cells, as well as phagocytosis by macrophages. Only the anti-HLA-DR mAb induced complement mediated lysis. Coincubation of different pairs of mAbs did not significantly modify the in vitro results. In contrast with these discrete and heterogeneous in vitro effects, in vivo the three mAbs demonstrated marked anti-tumour efficacy and prolongation of mice survival in two models of SCID mice, grafted either intraperitoneally or intravenously with the CD5 transfected JOK1-5.3 cells. This cell line was derived from a human hairy cell leukaemia, a type of malignancy known to have very similar biological properties as the B-CLL, whose cells constitutively express CD5. Interestingly, the combined injection of anti-CD5 with anti-HLA-DR or with anti-CD71 led to

  15. Binding of recombinant human proacrosin/acrosin to zona pellucida (ZP) glycoproteins. I. Studies with recombinant human ZPA, ZPB, and ZPC.

    Science.gov (United States)

    Furlong, Laura I; Harris, Jeffrey D; Vazquez-Levin, Mónica H

    2005-06-01

    To characterize proacrosin/acrosin interaction with isolated zona pellucida (ZP) components. Prospective study. Basic research laboratory. Recombinant proteins derived from human proacrosin (Rec-40, Rec-30, Rec-20, Rec-10, and Rec-6) and from human ZP glycoproteins (rec-hZPA, ZPB, and ZPC). In vitro binding assay developed to assess proacrosin/acrosin-ZP interaction. Zona pellucida glycoprotein binding to proacrosin/acrosin; estimation of binding affinity. Of all ZP proteins, rec-hZPA demonstrated the highest binding activity toward acrosin (Rec-30) (rec-hZPB: 42% of rec-hZPA; rec-hZPC: 39% of rec-hZPA; PZP components was observed (Kd: 34 nM for rec-hZPA, 38 nM for rec-hZPB, 63 nM for rec-hZPC). The rec-hZPA is the major ZP ligand for human proacrosin/acrosin. The interaction involves mannosyl, fucosyl, and sulfated glycans. Binding sites for rec-hZP would be located both at the N- and C-terminus of proacrosin, revealing a key role of the proenzyme in the interaction.

  16. Characterization and expression of the human T cell receptor-T3 complex by monoclonal antibody F101.01

    DEFF Research Database (Denmark)

    Geisler, C; Plesner, T; Pallesen, G

    1988-01-01

    A murine monoclonal antibody (MoAb) F101.01 reacting with the T cell receptor (TCR)-T3 complex is presented. Immunohistological studies showed that F101.01 specifically stains T-zone lymphocytes in lymph nodes, tonsils, and splenic tissue. Two-colour immunofluorescence and flow cytometry demonstr...

  17. The relationship between human T-lymphocyte subsets defined by monoclonal antibodies and by avidity differences to sheep erythrocytes

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Heron, I

    1982-01-01

    differences to sheep erythrocytes. Through a correlation was demonstrated between the T4+ (inducer) cells and the high avidity ("active") T cells and between the T8+ (suppressor) cells and low avidity T cells, these subsets were far from identical, and it is concluded that the application of monoclonal...

  18. Biological Validation of Plant-derived Anti-human Colorectal Cancer Monoclonal Antibody CO17-1A

    NARCIS (Netherlands)

    Jamal, Arshad; Ahn, Mi-Hyun; Song, Mira; Oh, Eun-Yi; Hong, Juyeon; Choo, Young-Kug; Ko, Kinarm; Han, Yeon Soo; Oh, Seung Han; Van Der Linden, Joke; Leusen, Jeanette H. W.; Ko, Kisung

    We validated expression and biological activities of plant-derived monoclonal antibody (MAb(P)) CO17-1A for its efficacy in cancer immunotherapy. PCR and immunoblot analyses demonstrated insertion and expression of heavy and light chains of MAb CO17-1A in transgenic plants, respectively. Confocal

  19. Safety of recombinant human platelet-derived growth factor-BB in Augment® Bone Graft

    Directory of Open Access Journals (Sweden)

    Luis A Solchaga

    2012-12-01

    Full Text Available This article discusses nonclinical and clinical data regarding the safety of recombinant human platelet-derived growth factor-BB as a component of the Augment® Bone Graft (Augment. Augment is a bone graft substitute intended to be used as an alternative to autologous bone graft in the fusion of hindfoot and ankle joints. Nonclinical studies included assessment of the pharmacokinetic profile of intravenously administered recombinant human platelet-derived growth factor-BB in rat and dog, effects of intravenous administration of recombinant human platelet-derived growth factor-BB in a reproductive and development toxicity study in rats, and chronic toxicity and carcinogenicity of Augment in a 12-month implantation model. These studies showed that systemic exposure was brief and clearance was rapid. No signs of toxicity, carcinogenicity, or tumor promotion were observed even with doses far exceeding the maximum clinical dose. Results of clinical trials (605 participants and commercial use of recombinant human platelet-derived growth factor-BB containing products indicate that these products are not associated with increased incidence of adverse events or cancer. The safety data presented provide evidence that recombinant human platelet-derived growth factor-BB is a safe therapeutic when used in combination products as a single administration during surgical procedures for bone repair and fusion. There is no evidence associating use of recombinant human platelet-derived growth factor-BB in Augment with chronic toxicity, carcinogenicity, or tumor promotion.

  20. Protection of non-human primates against rabies with an adenovirus recombinant vaccine

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Z.Q. [The Wistar Institute of Anatomy and Biology, Philadelphia, PA (United States); Greenberg, L. [Centers for Disease Control and Prevention, Atlanta, GA (United States); Ertl, H.C., E-mail: ertl@wistar.upenn.edu [The Wistar Institute of Anatomy and Biology, Philadelphia, PA (United States); Rupprecht, C.E. [The Global Alliance for Rabies Control, Manhattan, KS (United States); Ross University School of Veterinary Medicine, Basseterre (Saint Kitts and Nevis)

    2014-02-15

    Rabies remains a major neglected global zoonosis. New vaccine strategies are needed for human rabies prophylaxis. A single intramuscular immunization with a moderate dose of an experimental chimpanzee adenovirus (Ad) vector serotype SAd-V24, also termed AdC68, expressing the rabies virus glycoprotein, resulted in sustained titers of rabies virus neutralizing antibodies and protection against a lethal rabies virus challenge infection in a non-human primate model. Taken together, these data demonstrate the safety, immunogenicity, and efficacy of the recombinant Ad-rabies vector for further consideration in human clinical trials. - Highlights: • Pre-exposure vaccination with vaccine based on a chimpanzee derived adenovirus protects against rabies. • Protection is sustained. • Protection is achieved with single low-dose of vaccine given intramuscularly. • Protection is not affected by pre-existing antibodies to common human serotypes of adenovirus.

  1. Recombinant Production of Human Aquaporin-1 to an Exceptional High Membrane Density in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Bomholt, Julie; Hélix-Nielsen, Claus; Scharff-Poulsen, Peter

    2013-01-01

    In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tag......In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C...... at 15°C in a yeast host over-producing the Gal4p transcriptional activator and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30°C was due to in vivo mal-folding. Reduction...

  2. Pharmacokinetics, biodistribution and dosimetry of {sup 99m}Tc-labeled anti-human epidermal growth factor receptor humanized monoclonal antibody R3 in rats

    Energy Technology Data Exchange (ETDEWEB)

    Escobar, Normando Iznaga; Morales, Alejo Morales; Duconge, Jorge; Torres, Idania Caballero; Fernandez, Eduardo; Gomez, Jose A

    1998-01-01

    The pharmacokinetics, biodistribution and dosimetry of {sup 99m}Tc-labeled anti-human epidermal growth factor receptor (anti-hEGF-r) humanized monoclonal antibody (MAb) R3 was investigated following intravenous injection in normal Wistar rats. Serum disappearance curves were best fit by a two-compartment model having a mean distribution half-life (t{sub (1(2{alpha}}{sub ))}) of 0.250 h and a mean elimination (t{sub (1(2{beta}}{sub ))}) of 13.89 h. Among the various organs, a little accumulation of the radiolabeled antibody was found only in kidneys. Biodistribution and dosimetry studies in humans were performed by extrapolation of the animal data to humans. Absorbed dose to normal organs and the remainder of the whole body were estimated using the medical internal radiation dose formula, and dose contributions from radioactivity in transit through the gastrointestinal tract were estimated using a compartment model. Extrapolated values of radiation absorbed dose to normal organs in rads per millicurie administered were whole body, 0.0085; lower large intestine wall, 0.0898; small intestine, 0.0530; upper large intestine wall, 0.0731; and kidneys, 0.0455. The effective dose equivalent predicted was 0.0162 rem/mCi and the effective dose was found to be 0.015 rem/mCi. On the basis of the pharmacokinetics, biodistribution and internal radiation dosimetry information obtained in this study, a diagnostic phase I clinical trial with {sup 99m}Tc-labeled humanized MAb R3 conjugate in patients should be supported.

  3. Experimental studies of a vaccine formulation of recombinant human VEGF antigen with aluminum phosphate.

    Science.gov (United States)

    Pérez Sánchez, Lincidio; Morera Díaz, Yanelys; Bequet-Romero, Mónica; Ramses Hernández, Gerardo; Rodríguez, Yadira; Castro Velazco, Jorge; Puente Pérez, Pedro; Ayala Avila, Marta; Gavilondo, Jorge V

    2015-01-01

    CIGB-247 is a cancer vaccine that is a formulation of a recombinant protein antigen representative of the human vascular endothelial growth factor (VEGF) with a bacterially-derived adjuvant (VSSP). The vaccine has shown an excellent safety profile in mice, rats, rabbits, not-human primates and in recent clinical trials in cancer patients. Response to the vaccine is characterized by specific antibody titers that neutralize VEGF/VEGFR2 binding and a cytotoxic tumor-specific response. To expand our present anti-VEGF active immunotherapy strategies, we have now studied in mice and non-human primates the effects of vaccination with a formulation of our recombinant VEGF antigen and aluminum phosphate adjuvant (hereafter denominated CIGB-247-A). Administered bi-weekly, CIGB-247-A produces high titers of anti-VEGF IgG blocking antibodies in 2 mice strains. Particularly in BALB/c, the treatment impaired subcutaneous F3II mammary tumor growth and reduced the number of spontaneous lung macro metastases, increasing animals' survival. Spleen cells from specifically immunized mice directly killed F3II tumor cells in vitro. CIGB-247-A also showed to be immunogenic in non-human primates, which developed anti-VEGF blocking antibodies and the ability for specific direct cell cytotoxic responses, all without impairing the healing of deep skin wounds or other side effect. Our results support consideration of aluminum phosphate as a suitable adjuvant for the development of new vaccine formulations using VEGF as antigen.

  4. The Development of Novel Recombinant Human Gelatins as Replacements for Animal-Derived Gelatin in Pharmaceutical Applications

    Science.gov (United States)

    Olsen, David; Chang, Robert; Williams, Kim E.; Polarek, James W.

    We have developed a recombinant expression system to produce a series of novel recombinant human gelatins that can substitute for animal sourced gelatin preparations currently used in pharmaceutical and nutraceutical applications. This system allows the production of human sequence gelatins, or, if desired, gelatins from any other species depending on the availability of the cloned gene. The gelatins produced with this recombinant system are of defined molecular weight, unlike the animal-sourced gelatins, which consist of numerous polypeptides of varying size. The fermentation and purification process used to prepare these recombinant gelatins does not use any human- or animal-derived components and thus this recombinant material should be free from viruses and agents that cause transmissible spongiform encephalopathies. The recombinant gelatins exhibit lot-to-lot reproducibility and we have performed extensive analytical testing on them. We have demonstrated the utility of these novel gelatins as biological stabilizers and plasma expanders, and we have shown they possess qualities that are important in applications where gel formation is critical. Finally, we provide examples of how our system allows the engineering of these recombinant gelatins to optimize the production process.

  5. A comparative study of recombinant and native frutalin binding to human prostate tissues.

    Science.gov (United States)

    Oliveira, Carla; Teixeira, José A; Schmitt, Fernando; Domingues, Lucília

    2009-09-09

    Numerous studies indicate that cancer cells present an aberrant glycosylation pattern that can be detected by lectin histochemistry. Lectins have shown the ability to recognise these modifications in several carcinomas, namely in the prostate carcinoma, one of the most lethal diseases in man. Thus, the aim of this work was to investigate if the alpha-D-galactose-binding plant lectin frutalin is able to detect such changes in the referred carcinoma. Frutalin was obtained from different sources namely, its natural source (plant origin) and a recombinant source (Pichia expression system). Finally, the results obtained with the two lectins were compared and their potential use as prostate tumour biomarkers was discussed. The binding of recombinant and native frutalin to specific glycoconjugates expressed in human prostate tissues was assessed by using an immuhistochemical technique. A total of 20 cases of prostate carcinoma and 25 cases of benign prostate hyperplasia were studied. Lectins bound directly to the tissues and anti-frutalin polyclonal antibody was used as the bridge to react with the complex biotinilated anti-rabbit IgG plus streptavidin-conjugated peroxidase. DAB was used as visual indicator to specifically localise the binding of the lectins to the tissues. Both lectins bound to the cells cytoplasm of the prostate carcinoma glands. The binding intensity of native frutalin was stronger in the neoplasic cells than in hyperplasic cells; however no significant statistical correlation could be found (P = 0.051). On the other hand, recombinant frutalin bound exclusively to the neoplasic cells and a significant positive statistical correlation was obtained (P Native and recombinant frutalin yielded different binding responses in the prostate tissues due to their differences in carbohydrate-binding affinities. Also, this study shows that both lectins may be used as histochemical biomarkers for the prostate cancer. Moreover, the successful use of a recombinant

  6. A comparative study of recombinant and native frutalin binding to human prostate tissues

    Directory of Open Access Journals (Sweden)

    Domingues Lucília

    2009-09-01

    Full Text Available Abstract Background Numerous studies indicate that cancer cells present an aberrant glycosylation pattern that can be detected by lectin histochemistry. Lectins have shown the ability to recognise these modifications in several carcinomas, namely in the prostate carcinoma, one of the most lethal diseases in man. Thus, the aim of this work was to investigate if the α-D-galactose-binding plant lectin frutalin is able to detect such changes in the referred carcinoma. Frutalin was obtained from different sources namely, its natural source (plant origin and a recombinant source (Pichia expression system. Finally, the results obtained with the two lectins were compared and their potential use as prostate tumour biomarkers was discussed. Results The binding of recombinant and native frutalin to specific glycoconjugates expressed in human prostate tissues was assessed by using an immuhistochemical technique. A total of 20 cases of prostate carcinoma and 25 cases of benign prostate hyperplasia were studied. Lectins bound directly to the tissues and anti-frutalin polyclonal antibody was used as the bridge to react with the complex biotinilated anti-rabbit IgG plus streptavidin-conjugated peroxidase. DAB was used as visual indicator to specifically localise the binding of the lectins to the tissues. Both lectins bound to the cells cytoplasm of the prostate carcinoma glands. The binding intensity of native frutalin was stronger in the neoplasic cells than in hyperplasic cells; however no significant statistical correlation could be found (P = 0.051. On the other hand, recombinant frutalin bound exclusively to the neoplasic cells and a significant positive statistical correlation was obtained (P Conclusion Native and recombinant frutalin yielded different binding responses in the prostate tissues due to their differences in carbohydrate-binding affinities. Also, this study shows that both lectins may be used as histochemical biomarkers for the prostate

  7. Recombinant human interferon alpha 2b prevents and reverses experimental pulmonary hypertension.

    Directory of Open Access Journals (Sweden)

    Eileen M Bauer

    Full Text Available Pulmonary hypertension (PH is a progressive and fatal disease with no cure. Vascular remodeling in PH involves intraluminal growth of endothelial and smooth muscle cells, leading to obliterative vascular lesions. Cell growth in these lesions is quasi-neoplastic, with evidence of monoclonality, apoptosis resistance and cancer-like metabolic derangements. Herein we tested the effect of human interferon alpha 2b (IFNα, a pleiotropic cytokine and anti-cancer therapeutic, on the development and progression of PH in the rat SU5416/hypoxia (SUH model and mouse hypoxia model of the disease. In both models IFNα attenuated the development of PH and reversed established PH as assessed by measuring right ventricular systolic pressure and right ventricular hypertrophy. The effect of IFNα was dependent on the type I interferon receptor (IFNAR since mice lacking a subunit of the IFNAR were not protected by IFNα. Morphometric analysis of pulmonary aterioles from hypoxic mice or SUH rats showed that IFNα inhibited pulmonary vascular remodeling in both models and that IFNα reversed remodeling in SUH rats with established disease. Immunohistochemical staining revealed that IFNα decreased the number of PCNA and Tunel positive cells in the wall of pulmonary arterioles. In vitro, IFNα inhibited proliferation of human pulmonary artery smooth muscle cells and as well as human pulmonary artery endothelial cell proliferation and apoptosis. Together these findings demonstrate that IFNα reverses established experimental PH and provide a rationale for further exploration of the use of IFNα and other immunotherpies in PH.

  8. Comprehensive FISH probe design tool applied to imaging human immunoglobulin class switch recombination.

    Science.gov (United States)

    Nedbal, Jakub; Hobson, Philip S; Fear, David J; Heintzmann, Rainer; Gould, Hannah J

    2012-01-01

    We present a web engine boosted fluorescence in-situ hybridization (webFISH) algorithm using a genome-wide sequence similarity search to design target-specific single-copy and repetitive DNA FISH probes. The webFISH algorithm featuring a user-friendly interface (http://www.webfish2.org/) maximizes the coverage of the examined sequences with FISH probes by considering locally repetitive sequences absent from the remainder of the genome. The highly repetitive human immunoglobulin heavy chain sequence was analyzed using webFISH to design three sets of FISH probes. These allowed direct simultaneous detection of class switch recombination in both immunoglobulin-heavy chain alleles in single cells from a population of cultured primary B cells. It directly demonstrated asynchrony of the class switch recombination in the two alleles in structurally preserved nuclei while permitting parallel readout of protein expression by immunofluorescence staining. This novel technique offers the possibility of gaining unprecedented insight into the molecular mechanisms involved in class switch recombination.

  9. Towards a more precise serological diagnosis of human tegumentary leishmaniasis using Leishmania recombinant proteins.

    Directory of Open Access Journals (Sweden)

    Ana Paula Souza

    Full Text Available BACKGROUND: Exposure to Leishmania induces a humoral immune response that can be used as a marker of parasite exposure. METHODOLOGY/PRINCIPAL FINDINGS: Herein, ELISA was used to screen sera from patients with Tegumentary Leishmaniasis (TL against different L. infantum-chagasi-derived recombinant proteins (rHSP70, rH2A, rH2B, rH3, rH4 and rKMP11. Among the recombinant proteins, rHSP70 and rH2A showed the best reactivity against human sera obtained from endemic areas of TL. Receiver-Operator Characteristics (ROC curve analysis was used to identify the effectiveness of these proteins for serodiagnosis of TL. ROC curves confirmed the superior performance of rHSP70 and rH2A, in comparison to the other tested recombinant proteins. Additionally, we evaluated the specificity of the response to rHSP70 and rH2A by testing sera obtained from patients with Chagas' disease, Tuberculosis, Leprosy or Systemic Lupus Erythematosus. In this case, rHSP70 displayed an increased ability to discriminate diseases, in comparison to SLA. CONCLUSION: Our results raise possibility of using rHSP70 for the serodiagnosis of TL.

  10. Expression of functional recombinant human growth hormone in transgenic soybean seeds.

    Science.gov (United States)

    Cunha, Nicolau B; Murad, André M; Cipriano, Thaís M; Araújo, Ana Cláudia G; Aragão, Francisco J L; Leite, Adilson; Vianna, Giovanni R; McPhee, Timothy R; Souza, Gustavo H M F; Waters, Michael J; Rech, Elíbio L

    2011-08-01

    We produced human growth hormone (hGH), a protein that stimulates growth and cell reproduction, in genetically engineered soybean [Glycine max (L.) Merrill] seeds. Utilising the alpha prime (α') subunit of β-conglycinin tissue-specific promoter from soybean and the α-Coixin signal peptide from Coix lacryma-jobi, we obtained transgenic soybean lines that expressed the mature form of hGH in their seeds. Expression levels of bioactive hGH up to 2.9% of the total soluble seed protein content (corresponding to approximately 9 g kg(-1)) were measured in mature dry soybean seeds. The results of ultrastructural immunocytochemistry assays indicated that the recombinant hGH in seed cotyledonary cells was efficiently directed to protein storage vacuoles. Specific bioassays demonstrated that the hGH expressed in the soybean seeds was fully active. The recombinant hGH protein sequence was confirmed by mass spectrometry characterisation. These results demonstrate that the utilisation of tissue-specific regulatory sequences is an attractive and viable option for achieving high-yield production of recombinant proteins in stable transgenic soybean seeds.

  11. Towards a more precise serological diagnosis of human tegumentary leishmaniasis using Leishmania recombinant proteins.

    Science.gov (United States)

    Souza, Ana Paula; Soto, Manuel; Costa, Jackson M L; Boaventura, Viviane S; de Oliveira, Camila I; Cristal, Juqueline R; Barral-Netto, Manoel; Barral, Aldina

    2013-01-01

    Exposure to Leishmania induces a humoral immune response that can be used as a marker of parasite exposure. Herein, ELISA was used to screen sera from patients with Tegumentary Leishmaniasis (TL) against different L. infantum-chagasi-derived recombinant proteins (rHSP70, rH2A, rH2B, rH3, rH4 and rKMP11). Among the recombinant proteins, rHSP70 and rH2A showed the best reactivity against human sera obtained from endemic areas of TL. Receiver-Operator Characteristics (ROC) curve analysis was used to identify the effectiveness of these proteins for serodiagnosis of TL. ROC curves confirmed the superior performance of rHSP70 and rH2A, in comparison to the other tested recombinant proteins. Additionally, we evaluated the specificity of the response to rHSP70 and rH2A by testing sera obtained from patients with Chagas' disease, Tuberculosis, Leprosy or Systemic Lupus Erythematosus. In this case, rHSP70 displayed an increased ability to discriminate diseases, in comparison to SLA. Our results raise possibility of using rHSP70 for the serodiagnosis of TL.

  12. Towards a More Precise Serological Diagnosis of Human Tegumentary Leishmaniasis Using Leishmania Recombinant Proteins

    Science.gov (United States)

    Souza, Ana Paula; Soto, Manuel; Costa, Jackson M. L.; Boaventura, Viviane S.; de Oliveira, Camila I.; Cristal, Juqueline R.; Barral-Netto, Manoel; Barral, Aldina

    2013-01-01

    Background Exposure to Leishmania induces a humoral immune response that can be used as a marker of parasite exposure. Methodology/Principal Findings Herein, ELISA was used to screen sera from patients with Tegumentary Leishmaniasis (TL) against different L. infantum-chagasi-derived recombinant proteins (rHSP70, rH2A, rH2B, rH3, rH4 and rKMP11). Among the recombinant proteins, rHSP70 and rH2A showed the best reactivity against human sera obtained from endemic areas of TL. Receiver-Operator Characteristics (ROC) curve analysis was used to identify the effectiveness of these proteins for serodiagnosis of TL. ROC curves confirmed the superior performance of rHSP70 and rH2A, in comparison to the other tested recombinant proteins. Additionally, we evaluated the specificity of the response to rHSP70 and rH2A by testing sera obtained from patients with Chagas' disease, Tuberculosis, Leprosy or Systemic Lupus Erythematosus. In this case, rHSP70 displayed an increased ability to discriminate diseases, in comparison to SLA. Conclusion Our results raise possibility of using rHSP70 for the serodiagnosis of TL PMID:23776617

  13. Hydroxylation of recombinant human collagen type I alpha 1 in transgenic maize co-expressed with a recombinant human prolyl 4-hydroxylase

    Directory of Open Access Journals (Sweden)

    Pappu Kameshwari M

    2011-06-01

    Full Text Available Abstract Background Collagens require the hydroxylation of proline (Pro residues in their triple-helical domain repeating sequence Xaa-Pro-Gly to function properly as a main structural component of the extracellular matrix in animals at physiologically relevant conditions. The regioselective proline hydroxylation is catalyzed by a specific prolyl 4-hydroxylase (P4H as a posttranslational processing step. Results A recombinant human collagen type I α-1 (rCIα1 with high percentage of hydroxylated prolines (Hyp was produced in transgenic maize seeds when co-expressed with both the α- and β- subunits of a recombinant human P4H (rP4H. Germ-specific expression of rCIα1 using maize globulin-1 gene promoter resulted in an average yield of 12 mg/kg seed for the full-length rCIα1 in seeds without co-expression of rP4H and 4 mg/kg seed for the rCIα1 (rCIα1-OH in seeds with co-expression of rP4H. High-resolution mass spectrometry (HRMS analysis revealed that nearly half of the collagenous repeating triplets in rCIα1 isolated from rP4H co-expressing maize line had the Pro residues changed to Hyp residues. The HRMS analysis determined the Hyp content of maize-derived rCIα1-OH as 18.11%, which is comparable to the Hyp level of yeast-derived rCIα1-OH (17.47% and the native human CIa1 (14.59%, respectively. The increased Hyp percentage was correlated with a markedly enhanced thermal stability of maize-derived rCIα1-OH when compared to the non-hydroxylated rCIα1. Conclusions This work shows that maize has potential to produce adequately modified exogenous proteins with mammalian-like post-translational modifications that may be require for their use as pharmaceutical and industrial products.

  14. Use of Recombination-Mediated Genetic Engineering for Construction of Rescue Human Cytomegalovirus Bacterial Artificial Chromosome Clones

    Directory of Open Access Journals (Sweden)

    Kalpana Dulal

    2012-01-01

    Full Text Available Bacterial artificial chromosome (BAC technology has contributed immensely to manipulation of larger genomes in many organisms including large DNA viruses like human cytomegalovirus (HCMV. The HCMV BAC clone propagated and maintained inside E. coli allows for accurate recombinant virus generation. Using this system, we have generated a panel of HCMV deletion mutants and their rescue clones. In this paper, we describe the construction of HCMV BAC mutants using a homologous recombination system. A gene capture method, or gap repair cloning, to seize large fragments of DNA from the virus BAC in order to generate rescue viruses, is described in detail. Construction of rescue clones using gap repair cloning is highly efficient and provides a novel use of the homologous recombination-based method in E. coli for molecular cloning, known colloquially as recombineering, when rescuing large BAC deletions. This method of excising large fragments of DNA provides important prospects for in vitro homologous recombination for genetic cloning.

  15. Recombination gives a new insight in the effective population size and the history of the old world human populations.

    Science.gov (United States)

    Melé, Marta; Javed, Asif; Pybus, Marc; Zalloua, Pierre; Haber, Marc; Comas, David; Netea, Mihai G; Balanovsky, Oleg; Balanovska, Elena; Jin, Li; Yang, Yajun; Pitchappan, R M; Arunkumar, G; Parida, Laxmi; Calafell, Francesc; Bertranpetit, Jaume

    2012-01-01

    The information left by recombination in our genomes can be used to make inferences on our recent evolutionary history. Specifically, the number of past recombination events in a population sample is a function of its effective population size (Ne). We have applied a method, Identifying Recombination in Sequences (IRiS), to detect specific past recombination events in 30 Old World populations to infer their Ne. We have found that sub-Saharan African populations have an Ne that is approximately four times greater than those of non-African populations and that outside of Africa, South Asian populations had the largest Ne. We also observe that the patterns of recombinational diversity of these populations correlate with distance out of Africa if that distance is measured along a path crossing South Arabia. No such correlation is found through a Sinai route, suggesting that anatomically modern humans first left Africa through the Bab-el-Mandeb strait rather than through present Egypt.

  16. Nonclinical safety of mavrilimumab, an anti-GMCSF receptor alpha monoclonal antibody, in cynomolgus monkeys: Relevance for human safety

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Patricia C., E-mail: ryanp@medimmune.com [MedImmune, LLC, Gaithersburg, MD (United States); Sleeman, Matthew A. [MedImmune, LLC, Cambridge (United Kingdom); Rebelatto, Marlon [MedImmune, LLC, Gaithersburg, MD (United States); Wang, Bing; Lu, Hong [MedImmune, LLC, Moutain View, CA (United States); Chen, Xiaomin [Novartis, East Hanover, NJ (United States); Wu, Chi-Yuan [MedImmune, LLC, Moutain View, CA (United States); Hinrichs, Mary Jane; Roskos, Lorin [MedImmune, LLC, Gaithersburg, MD (United States); Towers, Heidi [MedImmune, LLC, Cambridge (United Kingdom); McKeever, Kathleen; Dixit, Rakesh [MedImmune, LLC, Gaithersburg, MD (United States)

    2014-09-01

    Mavrilimumab (CAM-3001) is an investigational human IgG4 monoclonal antibody (MAb) targeting GM-CSF receptor alpha which is currently being developed for the treatment of RA. GM-CSF plays a central role in the pathogenesis of rheumatoid arthritis (RA) through the activation, differentiation, and survival of macrophages and neutrophils. To support clinical development, the nonclinical safety of mavrilimumab was evaluated in several studies with cynomolgus monkeys as the pharmacologically relevant species. Comprehensive toxicity parameters were assessed in each study, and treatment duration ranged from 4 to 26 weeks. Mavrilimumab has an acceptable safety profile in monkeys with no changes in any parameters other than microscopic findings in lung. In several studies, minimal accumulation of foamy alveolar macrophages was observed. This finding was only seen in studies of at least 11 weeks duration, was reversible following a dose-free recovery period and was considered non-adverse. At higher dose levels (≥ 30 mg/kg/week), in a 26-week repeat-IV dose study, the presence of lung foreign material, cholesterol clefts, and granulomatous inflammation was also observed in a few animals and was considered adverse. The dose- and time-related accumulation of foamy macrophages in lung following exposure to mavrilimumab observed in several NHP studies was expected based upon the known role of GM-CSFRα signaling in the function of alveolar macrophages. Overall, a clean no-observed-adverse-effect-level (NOAEL) without any effects in lung was established and provided adequate clinical safety margins. In clinical studies in RA patients, mavrilimumab has demonstrated good clinical activity with adequate safety to support further clinical development. A Phase 2b study of mavrilimumab in subjects with RA is in progress. - Highlights: • Mavrilimumab is a MAB targeting GM-CSFRα being developed for RA therapy. • Mavrilimumab has an acceptable safety profile in cynomolgus monkeys.

  17. Quantitative PET imaging of Met-expressing human cancer xenografts with {sup 89}Zr-labelled monoclonal antibody DN30

    Energy Technology Data Exchange (ETDEWEB)

    Perk, Lars R.; Stigter-van Walsum, Marijke; Vosjan, Maria J.W.D.; Leemans, C.R. [VU University Medical Centre, Department of Otolaryngology-Head and Neck Surgery, De Boelelaan 1117, P.O. Box 7057, Amsterdam (Netherlands); Visser, Gerard W.M.; Kloet, Reina W. [VU University Medical Centre, Nuclear Medicine and PET Research, Amsterdam (Netherlands); Giaccone, Giuseppe [National Cancer Institute, Medical Oncology Branch CCR, Bethesda, MD (United States); Albano, Raffaella; Comoglio, Paolo M. [University of Turin Medical School, Division of Molecular Oncology, Institute for Cancer Research and Treatment (IRCC), Turin (Italy); Dongen, Guus A.M.S. van [VU University Medical Centre, Department of Otolaryngology-Head and Neck Surgery, De Boelelaan 1117, P.O. Box 7057, Amsterdam (Netherlands); VU University Medical Centre, Nuclear Medicine and PET Research, Amsterdam (Netherlands)

    2008-10-15

    Targeting the c-Met receptor with monoclonal antibodies (MAbs) is an appealing approach for cancer diagnosis and treatment because this receptor plays a prominent role in tumour invasion and metastasis. Positron emission tomography (PET) might be a powerful tool for guidance of therapy with anti-Met MAbs like the recently described MAb DN30 because it allows accurate quantitative imaging of tumour targeting (immuno-PET). We considered the potential of PET with either {sup 89}Zr-labelled (residualising radionuclide) or {sup 124}I-labelled (non-residualising radionuclide) DN30 for imaging of Met-expressing tumours. The biodistribution of co-injected {sup 89}Zr-DN30 and iodine-labelled DN30 was compared in nude mice bearing either the human gastric cancer line GLT-16 (high Met expression) or the head-and-neck cancer line FaDu (low Met expression). PET images were acquired in both xenograft models up to 4 days post-injection (p.i.) and used for quantification of tumour uptake. Biodistribution studies in GTL-16-tumour-bearing mice revealed that {sup 89}Zr-DN30 achieved much higher tumour uptake levels than iodine-labelled DN30 (e.g. 19.6%ID/g vs 5.3%ID/g, 5 days p.i.), while blood levels were similar, indicating internalisation of DN30. Therefore, {sup 89}Zr-DN30 was selected for PET imaging of GLT-16-bearing mice. Tumours as small as 11 mg were readily visualised with immuno-PET. A distinctive lower {sup 89}Zr uptake was observed in FaDu compared to GTL-16 xenografts (e.g. 7.8%ID/g vs 18.1%ID/g, 3 days p.i.). Nevertheless, FaDu xenografts were also clearly visualised with {sup 89}Zr-DN30 immuno-PET. An excellent correlation was found between PET-image-derived {sup 89}Zr tumour uptake and ex-vivo-assessed {sup 89}Zr tumour uptake (R {sup 2} = 0.98). The long-lived positron emitter {sup 89}Zr seems attractive for PET-guided development of therapeutic anti-c-Met MAbs. (orig.)

  18. Comparison of an anti-rabies human monoclonal antibody combination with human polyclonal anti-rabies immune globulin

    NARCIS (Netherlands)

    Goudsmit, Jaap; Marissen, Wilfred E.; Weldon, William C.; Niezgoda, Michael; Hanlon, Cathleen A.; Rice, Amy B.; Kruif, John de; Dietzschold, Bernhard; Bakker, Alexander B. H.; Rupprecht, Charles E.

    2006-01-01

    The World Health Organization estimates human mortality from endemic canine rabies to be 55,000 deaths/year. Limited supply hampers the accessibility of appropriate lifesaving treatment, particularly in areas where rabies is endemic. Anti-rabies antibodies are key to protection against lethal

  19. Recombinant tandem multi-linear neutralizing epitopes of human enterovirus 71 elicited protective immunity in mice.

    Science.gov (United States)

    Li, Yue-Xiang; Zhao, Hui; Cao, Rui-Yuan; Deng, Yong-Qiang; Han, Jian-Feng; Zhu, Shun-Ya; Ma, Jie; Liu, Long; Qin, E-De; Qin, Cheng-Feng

    2014-05-06

    Human Enterovirus 71 (EV71) has emerged as the leading cause of viral encephalitis in children, especially in the Asia-Pacific regions. EV71 vaccine development is of high priority at present, and neutralization antibodies have been documented to play critical roles during in vitro and in vivo protection against EV71 infection. In this study, a novel strategy to produce EV71 vaccine candidate based on recombinant multiple tandem linear neutralizing epitopes (mTLNE) was proposed. The three well identified EV71 linear neutralizing epitopes in capsid proteins, VP1-SP55, VP1-SP70 and VP2-SP28, were sequentially linked by a Gly-Ser linker ((G4S)3), and expressed in E.coli in fusion with the Trx and His tag at either terminal. The recombinant protein mTLNE was soluble and could be purified by standard affinity chromatography. Following three dosage of immunization in adult mice, EV71-specific IgG and neutralization antibodies were readily induced by recombinant mTLNE. IgG subtyping demonstrated that lgG1 antibodies dominated the mTLNE-induced humoral immune response. Especially, cytokine profiling in spleen cells from the mTLNE-immunized mice revealed high production of IL-4 and IL-6. Finally, in vivo challenge experiments showed that passive transfer with anti-mTLNE sera conferred full protection against lethal EV71 challenge in neonatal mice. Our results demonstrated that this rational designed recombinant mTLNE might have the potential to be further developed as an EV71 vaccine in the future.

  20. An IgE epitope of Bet v 1 and fagales PR10 proteins as defined by a human monoclonal IgE

    DEFF Research Database (Denmark)

    Hecker, J.; Diethers, A.; Schulz, D.

    2012-01-01

    BACKGROUND: Analyses of the molecular basis underlying allergenicity and allergen cross-reactivity, as well as improvement of allergy diagnostics and therapeutics, are hampered by the lack of human monoclonal IgE antibodies and knowledge about their epitopes. Here, we addressed the consecutive...... formats including IgE. Using variants of Bet v 1, the epitope of the antibody was mapped and extrapolated to other PR10 proteins. RESULTS: The obtained antibodies exhibited pronounced reactivity with Bet v 1, but were not reactive with the homologous PR10 protein Mal d 1. The epitope as defined by the Ig...

  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

    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...

  2. Radioiodine therapy of benign non-toxic goitre. Potential role of recombinant human TSH

    DEFF Research Database (Denmark)

    Fast, S; Bonnema, S J; Hegedüs, L

    2011-01-01

    This review provides an update on recombinant human TSH (rh-TSH) augmented radioiodine (¹³¹I) therapy and outlines its potential role in the treatment of symptomatic benign multinodular non-toxic goitre. In some countries, ¹³¹I has been used for three decades to reduce the size of nodular goitres......-reduction (equality) strategy is attractive in terms of minimizing post-therapeutic restrictions and in reducing the potential risk of radiation-induced malignancy. Adverse effects like temporary thyroid swelling and thyroid hormone excess are to a large extent dose-dependent and generally 0.1mg rh-TSH or less...

  3. Recombinant DNA human interferon alpha 2 in advanced breast cancer: a phase 2 trial.

    OpenAIRE

    Padmanabhan, N.; Balkwill, F. R.; Bodmer, J. G.; Rubens, R. D.

    1985-01-01

    Effectiveness of recombinant DNA (rDNA) human interferon alpha 2 (IFN alpha 2) in advanced breast cancer was evaluated in 14 patients who had received prior endocrine and/or cytotoxic therapy. After randomization, 7 patients received IFN alpha 2 two million IU m-2 day-1, s.c., 3 times a week (schedule 1) and 7 patients received 50 million IU m-2 day-1, i.v., for 5 consecutive days, every 3 weeks (schedule 2). Treatment duration was 4-21 weeks in schedule 1 and 6-24 weeks (2-8 courses) in sche...

  4. Recombinant erythropoietin in humans has a prolonged effect on circulating erythropoietin isoform distribution

    DEFF Research Database (Denmark)

    Aachmann-Andersen, Niels Jacob; Just Christensen, Søren; Lisbjerg, Kristian

    2014-01-01

    The membrane-assisted isoform immunoassay (MAIIA) quantitates erythropoietin (EPO) isoforms as percentages of migrated isoforms (PMI). We evaluated the effect of recombinant human EPO (rhEPO) on the distribution of EPO isoforms in plasma in a randomized, placebo-controlled, double-blinded, cross...... beta: 73.1 (17.8)% (p=0.039)). In conclusion, Epoetin beta leaves a footprint in the plasma-EPO isoform pattern. MAIIA can detect changes in EPO isoform distribution up til at least three weeks after administration of Epoetin beta even though the total EPO concentration has returned to normal....

  5. Safety of human papillomavirus 6, 11, 16 and 18 (recombinant): systematic review and meta-analysis

    Science.gov (United States)

    Coelho, Pedro Luiz Spinelli; Calestini, Gustavo Lacerda da Silva; Alvo, Fernando Salgueiro; Freitas, Jefferson Michel de Moura; Castro, Paula Marcela Vilela; Konstantyner, Tulio

    2015-01-01

    Objective: To identify and quantify the adverse effects associated with the recombinant human papillomavirus (types 6, 11, 16 and 18) vaccine in adolescents. Data source: Systematic review of randomized clinical trials from PubMed, SciELO and Lilacs databases. Articles investigating the safety of the vaccine in subjects under 18 years and comparing the recombinant human papillomavirus types 6, 11, 16 and 18 vaccine with a control group were included. Meta-analyses were performed for the outcomes of pain, erythema, swelling and fever, using clinical trials with maximum Jadad score. Data synthesis: Fourteen studies were included. The most common adverse effects related to the human papillomavirus vaccine were effects with no severity (pain, erythema, edema, and fever). Five studies were used for the meta-analyses: pain-risk difference (RD)=11% (phuman papillomavirus types 6, 11, 16 and 18 vaccine was safe and well tolerated. The main adverse effects related to vaccination were pain, erythema, edema and fever. The low frequency of severe adverse effects encourages the administration of the vaccine in the population at risk. PMID:26376359

  6. Generation of biologically active multi-sialylated recombinant human EPOFc in plants.

    Directory of Open Access Journals (Sweden)

    Alexandra Castilho

    Full Text Available Hyperglycosylated proteins are more stable, show increased serum half-life and less sensitivity to proteolysis compared to non-sialylated forms. This applies particularly to recombinant human erythropoietin (rhEPO. Recent progress in N-glycoengineering of non-mammalian expression hosts resulted in in vivo protein sialylation at great homogeneity. However the synthesis of multi-sialylated N-glycans is so far restricted to mammalian cells. Here we used a plant based expression system to accomplish multi-antennary protein sialylation. A human erythropoietin fusion protein (EPOFc was transiently expressed in Nicotiana benthamiana ΔXTFT, a glycosylation mutant that lacks plant specific N-glycan residues. cDNA of the hormone was co-delivered into plants with the necessary genes for (i branching (ii β1,4-galactosylation as well as for the (iii synthesis, transport and transfer of sialic acid. This resulted in the production of recombinant EPOFc carrying bi- tri- and tetra-sialylated complex N-glycans. The formation of this highly complex oligosaccharide structure required the coordinated expression of 11 human proteins acting in different subcellular compartments at different stages of the glycosylation pathway. In vitro receptor binding assays demonstrate the generation of biologically active molecules. We demonstrate the in planta synthesis of one of the most complex mammalian glycoforms pointing to an outstanding high degree of tolerance to changes in the glycosylation pathway in plants.

  7. Phage display derived human monoclonal antibodies isolated by binding to the surface of live primary breast cancer cells recognize GRP78

    DEFF Research Database (Denmark)

    Jakobsen, Charlotte G; Rasmussen, Nicolaj; Laenkholm, Anne-Vibeke

    2007-01-01

    of novel targets and human antibodies against them. We have isolated single-chain human mAbs from a large naïve antibody phage display library by panning on a single-cell suspension of freshly isolated live cancer cells from a human breast cancer specimen, and these antibodies were shown to specifically......Clinical trials using monoclonal antibodies (mAb) against cell-surface markers have yielded encouraging therapeutic results in several cancer types. Generally, however, anticancer antibodies are only efficient against a subpopulation of cancers, and there is a strong need for identification...... bound strongly to several cancers, including 45% breast carcinomas, 35% lung cancers, and 86% melanomas, but showed no or weak binding to normal tissues. A yeast two-hybrid screen of a large human testis cDNA library identified the glucose-regulated protein of 78 kDa (GRP78) as the antigen recognized...

  8. High-throughput isolation of immunoglobulin genes from single human B cells and expression as monoclonal antibodies

    Science.gov (United States)

    Liao, Hua-Xin; Levesque, Marc C.; Nagel, Ashleigh; Dixon, Ashlyn; Zhang, Ruijun; Walter, Emmanuel; Parks, Robert; Whitesides, John; Marshall, Dawn J.; Hwang, Kwan-Ki; Yang, Yi; Chen, Xi; Gao, Feng; Munshaw, Supriya; Kepler, Thomas B.; Denny, Thomas; Moody, M. Anthony; Haynes, Barton F.

    2009-01-01

    Defining human B cell repertoires to viral pathogens is critical for design of vaccines that induce broadly protective antibodies to infections such as HIV-1 and influenza. Single B cell sorting and cloning of immunoglobulin (Ig) heavy- and light-chain variable regions (VH and VL) is a powerful technology for defining anti-viral B cell repertoires. However, the Ig-cloning step is time-consuming and prevents high-throughput analysis of the B cell repertoire. Novel linear Ig heavy- and light-chain gene expression cassettes were designed to express Ig VH and VL genes isolated from sorted single B cells as IgG1 antibody without a cloning step. The cassettes contain all essential elements for transcriptional and translational regulation, including CMV promoter, Ig leader sequences, constant region of IgG1 heavy- or Ig light-chain, poly(A) tail and substitutable VH or VL genes. The utility of these Ig gene expression cassettes was established using synthetic VH or VL genes from an anti-HIV-1 gp41 mAb 2F5 as a model system, and validated further using VH and VL genes isolated from cloned EBV-transformed antibody-producing cell lines. Finally, this strategy was successfully used for rapid production of recombinant influenza mAbs from sorted single human plasmablasts after influenza vaccination. These Ig gene expression cassettes constitute a highly efficient strategy for rapid expression of Ig genes for high-throughput screening and analysis without cloning. PMID:19428587

  9. Activation of human natural killer cells by the novel innate immune modulator recombinant Eimeria antigen.

    Science.gov (United States)

    Aylsworth, Charles F; Aldhamen, Yasser A; Seregin, Sergey S; Godbehere, Sarah; Amalfitano, Andrea

    2013-08-01

    The safe and effective activation of the innate and adaptive immune systems are crucial in the implementation of immunotherapeutic modalities for the prevention and treatment of human diseases. Eimeria antigen (EA) and its recombinantly expressed analog (rEA) are extremely effective activators of innate immunity in mice. The effects of rEA in the mouse are primarily mediated through the TLR11/12 MyD88 signaling system. Human cells lack functional TLR11 and TLR12, suggesting that rEA would not be effective in providing beneficial immune activation in humans. In the current report we provide definitive evidence that the treatment of human peripheral blood mononuclear cell (PBMC) cultures with rEA significantly up regulates CD69, CD107, NKG2D levels on NK cells. Furthermore, rEA stimulates human NK cell effector functions including increasing intracellular levels of IFNγ and Granzyme B. These responses are positively correlated with an improved capacity of rEA stimulated human PBMCs to kill NK cell-sensitive human K562 tumor cells. Importantly, rEA-triggered innate immune responses was not associated with increased pro-inflammatory cytokines and chemokines production. These data confirm a previously unidentified role for rEA in human immune cell activation, and suggests the utilization of rEA in immunotherapies against a variety of infectious diseases and cancers. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  10. Epitope mapping of a monoclonal antibody against human thrombin by H/D-exchange mass spectrometry reveals selection of a diverse sequence in a highly conserved protein.

    Science.gov (United States)

    Baerga-Ortiz, Abel; Hughes, Carrie A; Mandell, Jeffrey G; Komives, Elizabeth A

    2002-06-01

    The epitope of a monoclonal antibody raised against human thrombin has been determined by hydrogen/deuterium exchange coupled to MALDI mass spectrometry. The antibody epitope was identified as the surface of thrombin that retained deuterium in the presence of the monoclonal antibody compared to control experiments in its absence. Covalent attachment of the antibody to protein G beads and efficient elution of the antigen after deuterium exchange afforded the analysis of all possible epitopes in a single MALDI mass spectrum. The epitope, which was discontinuous, consisting of two peptides close to anion-binding exosite I, was readily identified. The epitope overlapped with, but was not identical to, the thrombomodulin binding site, consistent with inhibition studies. The antibody bound specifically to human thrombin and not to murine or bovine thrombin, although these proteins share 86% identity with the human protein. Interestingly, the epitope turned out to be the more structured of two surface regions in which higher sequence variation between the three species is seen.

  11. Glycosylation profiling of a therapeutic recombinant monoclonal antibody with two N-linked glycosylation sites using liquid chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer.

    Science.gov (United States)

    Lim, Amareth; Reed-Bogan, Angelia; Harmon, Bryan J

    2008-04-15

    Monoclonal antibodies have been used increasingly as therapeutic agents to target various diseases. Although most monoclonal antibodies have only one N-linked glycosylation site in the Fc region, N-linked glycosylation sites in the Fab region have also been observed. Because glycosylation of a monoclonal antibody can have a significant impact on its effector function, efficacy, clearance, and immunogenicity, it is essential to assess the glycosylation profile during cell line and clone selection studies and to assess the impact of cell culture conditions on the glycoform distribution during process optimization studies to ensure that the antibody is being produced with appropriate and consistent glycosylation. This article describes a liquid chromatography-mass spectrometry-based approach, in combination with papain digestion and partial reduction, to obtain site-specific glycosylation profile information for a therapeutic monoclonal antibody with two N-linked glycosylation sites in the heavy chain.

  12. Monoclonal antibody Po66 uptake by human lung tumours implanted in nude mice: effect of co-administration with doxorubicin.

    OpenAIRE

    Desrues, B.; L?na, H.; Brichory, F.; Ram?e, M. P.; Toujas, L; Delaval, P.; Dazord, L

    1995-01-01

    The efficacy of radioimmunotherapy of tumours with radiolabelled monoclonal antibodies (MAbs) depends on the amount of antibody taken up by the tumour and on its intratumoral distribution. In the case of MAbs directed against intracellular antigens, increasing the permeability of the cytoplasmic membrane may augment the bioavailability of the antigen for the antibody. This raises the question whether the induction of tumour necrosis by chemotherapy can enhance the tumour uptake of radiolabell...

  13. Partial correlation analysis indicates causal relationships between GC-content, exon density and recombination rate in the human genome.

    Science.gov (United States)

    Freudenberg, Jan; Wang, Mingyi; Yang, Yaning; Li, Wentian

    2009-01-30

    Several features are known to correlate with the GC-content in the human genome, including recombination rate, gene density and distance to telomere. However, by testing for pairwise correlation only, it is impossible to distinguish direct associations from indirect ones and to distinguish between causes and effects. We use partial correlations to construct partially directed graphs for the following four variables: GC-content, recombination rate, exon density and distance-to-telomere. Recombination rate and exon density are unconditionally uncorrelated, but become inversely correlated by conditioning on GC-content. This pattern indicates a model where recombination rate and exon density are two independent causes of GC-content variation. Causal inference and graphical models are useful methods to understand genome evolution and the mechanisms of isochore evolution in the human genome.

  14. Production of a Monoclonal Antibody Specific for the Major Outer Membrane Protein of Campylobacter jejuni and Characterization of the Epitope▿

    OpenAIRE

    Qian, Hongliang; Pang, Ervinna; Du, Qingyun; Chang, Jason; Dong, Jin; Toh, Say Ling; Ng, Fook Kheong; Tan, Ai Ling; Kwang, Jimmy

    2007-01-01

    Campylobacter species are important enteric pathogens causing disease in humans and animals. There is a lack of a good immunological test that can be used routinely to separate Campylobacter jejuni from other Campylobacter species. We produced monoclonal antibodies (MAbs) directed against the major outer membrane protein (MOMP) of C. jejuni using recombinant MOMP as the antigen. One MAb, designated MAb5C4 and of the immunoglobulin G1 isotype, was found to be potentially specific for C. jejuni...

  15. Partial correlation analysis indicates causal relationships between GC-content, exon density and recombination rate in the human genome

    OpenAIRE

    Li Wentian; Yang Yaning; Wang Mingyi; Freudenberg Jan

    2009-01-01

    Abstract Background Several features are known to correlate with the GC-content in the human genome, including recombination rate, gene density and distance to telomere. However, by testing for pairwise correlation only, it is impossible to distinguish direct associations from indirect ones and to distinguish between causes and effects. Results We use partial correlations to construct partially directed graphs for the following four variables: GC-content, recombination rate, exon density and ...

  16. N-glycans of recombinant human acid α-glucosidase expressed in the milk of transgenic rabbits

    OpenAIRE

    Jongen, Susanne; Gerwig, Gerrit; Leeflang, Bas; Koles, Kate; Mannesse, Maurice; Berkel, Patrick; Pieper, Frank; Kroos, Marian; Reuser, Arnold; Zhou, Qun; Jin, Xiaoying; Zhang, Kate; Edmunds, Tim; Kamerling, Johannis

    2007-01-01

    textabstractPompe disease is a lysosomal glycogen storage disorder characterized by acid α-glucosidase (GAA) deficiency. More than 110 different pathogenic mutations in the gene encoding GAA have been observed. Patients with this disease are being treated by intravenous injection of recombinant forms of the enzyme. Focusing on recombinant approaches to produce the enzyme means that specific attention has to be paid to the generated glycosylation patterns. Here, human GAA was expressed in the ...

  17. Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens.

    Directory of Open Access Journals (Sweden)

    Hanyu Wu

    Full Text Available Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies.

  18. Value of recombinant human epidermal growth factor in corneal wound repair after corneal foreign body elimination

    Directory of Open Access Journals (Sweden)

    Hong-Jie Han

    2013-11-01

    Full Text Available AIM: To investigate the repair efficacy of recombinant human epidermal growth factor on corneal epithelium after corneal foreign body eliminating operation. METHODS: There were 102 patients with corneal foreign body(188 affected eyeschosen for the study. All patients were divided into treatment group and control group according to the random number table. Both groups received corneal foreign body elimination by slit lamp. Postoperatively, the treatment group was given eye drops containing epidermal growth factor(JinYinShucombined with tobramycin while the control group was only administrated with tobramycin. Treatment effects were compared 3d after treatment. RESULTS: Three days after treatment, the cure rate in the treatment group(93.7%, was significantly higher than that in the control group(76.6%(PPCONCLUSION: The recombinant human epidermal growth factor is capable of integrating with corneal epithelial cells and endothelial cell receptor, shortening healing time of corneal epithelial wound, thus making it an effective treatment of traumatic corneal epithelial defect.

  19. Inhibitory effects of pomegranate extracts on recombinant human maltase-glucoamylase.

    Science.gov (United States)

    Kawakami, Kayoko; Li, Peng; Uraji, Misugi; Hatanaka, Tadashi; Ito, Hideyuki

    2014-09-01

    α-Glucosidase inhibitors are currently used in the treatment of type 2 diabetes. In this study, we investigated the inhibitory activities of aril and pericarp extracts from pomegranates obtained various regions against recombinant human maltase-glucoamylase (MGAM). The inhibitory activities of the aril extracts tended to be stronger than those of the pericarp extracts. The Iranian aril extract was the most effective inhibitor. We investigated the polyphenol content of the pomegranate extracts using the Folin-Ciocalteu method. Among the aril extracts, the Iranian aril extract showed the highest polyphenol content. We further evaluated inhibitory activity against α-glucosidase from the rat small intestine. Pomegranate extract used in this study showed slightly different inhibitory activities according to α-glucosidase origin. Iranian aril extract was the most effective inhibitor of α-glucosidases, especially recombinant human MGAM. Bioassay-guided fractionation of the pomegranate arils led to identification of punicalagin and oenothein B as potent inhibitors of α-glucosidase. Oenothein B showed inhibitory activity with a half-maximal inhibitory concentration (IC(50)) value of 174 μM. Its potency was comparable to that of the α-glucosidase inhibitor acarbose with an IC(50) value of 170 μM. Dixon plot kinetic analysis of oenothein B showed a noncompetitive inhibition with a K(i) value of 102 μM. These results suggest that pomegranate arils would be useful for suppressing postprandial hyperglycemia. © 2014 Institute of Food Technologists®

  20. A Butter Aroma Recombinate Activates Human Class-I Odorant Receptors.

    Science.gov (United States)

    Geithe, Christiane; Andersen, Gaby; Malki, Agne; Krautwurst, Dietmar

    2015-11-04

    With ∼400 olfactory G protein-coupled receptors (GPCR), humans sensitively perceive ∼230 key aroma compounds as best natural agonists of ∼10000 food volatiles. An understanding of odorant coding, thus, critically depends on the knowledge about interactions of key food aroma chemicals and their mixtures with their cognate receptors. Genetically designed test cell systems enable the screening, deorphaning, and characterization of single odorant receptors (OR). This study shows for the food aroma-specific and quantitative butter aroma recombinate, and its single components, specific in vitro class-I OR activity patterns, as well as the activation of selected OR in a concentration-dependent manner. Recently, chemosensory receptors, especially class-I OR, were demonstrated to be expressed on blood leukocytes, which may encounter foodborne aroma compounds postprandially. This study shows that butter aroma recombinate induced chemotaxis of isolated human neutrophils in a defined gradient, and in a concentration-dependent and pertussis toxin-sensitive manner, suggesting at least a GPCR-mediated activation of blood leukocytes by key food odorants.

  1. Physical Characterization of human centromeric regions using transformation-associated recombination cloning technology

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir Larionov, Ph D

    2007-06-05

    A special interest in the organization of human centromeric DNA was stimulated a few years ago when two independent groups succeeded in reconstituting a functional human centromere, using constructs carrying centromere-specific alphoid DNA arrays. This work demonstrated the importance of DNA components in mammalian centromeres and opened a way for studying the structural requirements for de novo kinetochore formation and for construction of human artificial chromosomes (HACs) with therapeutic potential. To elucidate the structural requirements for formation of HACs with a functional kinetochore, we developed a new method for cloning of large DNA fragments for human centromeric regions that can be used as a substrate for HAC formation. This method exploits in vivo recombination in yeast (TAR cloning). In addition, a new strategy for the construction of alphoid DNA arrays was developed in our lab. The strategy involves the construction of uniform or hybrid synthetic alphoid DNA arrays by the RCA-TAR technique. This technique comprises two steps: rolling circle amplification of an alphoid DNA dimer and subsequent assembling of the amplified fragments by in vivo homologous recombination in yeast (Figure 1). Using this system, we constructed a set of different synthetic alphoid DNA arrays with a predetermined sequence varying in size from 30 to 140 kb and demonstrated that some of the arrays are competent in HAC formation. Because any nucleotide can be changed in a dimer before its amplification, this new technique is optimal for identifying the structural requirements for de novo kinetochore formation in HACs. Moreover, the technique makes possible to introduce into alphoid DNA arrays recognition sites for DNA-binding proteins. We have made the following progress on the studying of human centromeric regions using transformation-associated recombination cloning technology: i) minimal size of alphoid DNA array required for de novo kinetochore formation was estimated; ii

  2. A single dose of neuron-binding human monoclonal antibody improves spontaneous activity in a murine model of demyelination.

    Directory of Open Access Journals (Sweden)

    Aleksandar Denic

    Full Text Available Our laboratory demonstrated that a natural human serum antibody, sHIgM12, binds to neurons in vitro and promotes neurite outgrowth. We generated a recombinant form, rHIgM12, with identical properties. Intracerebral infection with Theiler's Murine Encephalomyelitis Virus (TMEV of susceptible mouse strains results in chronic demyelinating disease with progressive axonal loss and neurologic dysfunction similar to progressive forms of multiple sclerosis. To study the effects of rHIgM12 on the motor function of TMEV-infected mice, we monitored spontaneous nocturnal activity over many weeks. Nocturnal behavior is a sensitive measure of rodent neurologic function because maximal activity changes are expected to occur during the normally active night time monitoring period. Mice were placed in activity boxes eight days prior to treatment to collect baseline spontaneous activity. After treatment, activity in each group was continuously recorded over 8 weeks. We chose a long 8-week monitoring period for two reasons: (1 we previously demonstrated that IgM induced remyelination is present by 5 weeks post treatment, and (2 TMEV-induced demyelinating disease in this strain progresses very slowly. Due to the long observation periods and large data sets, differences among treatment groups may be difficult to appreciate studying the original unfiltered recordings. To clearly delineate changes in the highly fluctuating original data we applied three different methods: (1 binning, (2 application of Gaussian low-pass filters (GF and (3 polynomial fitting. Using each of the three methods we showed that compared to control IgM and saline, early treatment with rHIgM12 induced improvement in both horizontal and vertical motor function, whereas later treatment improved only horizontal activity. rHIgM12 did not alter activity of normal, uninfected mice. This study supports the hypothesis that treatment with a neuron-binding IgM not only protects neurons in vitro, but

  3. Improvement of lymphocyte proliferation in human immunodeficiency virus infection after recombinant interleukin-2 treatment

    DEFF Research Database (Denmark)

    Afzelius, P; Nielsen, S D; Nielsen, Jens Ole

    1999-01-01

    In this study, the effect of recombinant interleukin-2 (rIL-2) on the function of peripheral blood mononuclear cells (PBMC) from human immunodeficiency virus (HIV)-infected patients was examined. Using polymerase chain reaction (PCR), an impaired ability of PBMC from 8 patients to respond upon...... mitogen stimulation with expression of IL-2 and IL-2 receptor (IL-2R) messenger ribonucleic acid (mRNA) was found compared with healthy donors (p = 0.02 and p = 0.05, respectively). Flow cytometry was used to determine the expression of p55 interleukin-2 alpha-receptor (CD25) after phytohaemagglutinin......, the induced gene expressions for IL-2 and IL-2R were positively correlated (p IL-2 and IL-2R genes in humans may share a common activation pathway, as has been found in monkeys infected by simian immunodeficiency virus (SIV). These results indicate...

  4. The basic N-terminal domain of TRF2 limits recombination endonuclease action at human telomeres.

    Science.gov (United States)

    Saint-Léger, Adélaïde; Koelblen, Melanie; Civitelli, Livia; Bah, Amadou; Djerbi, Nadir; Giraud-Panis, Marie-Josèphe; Londoño-Vallejo, Arturo; Ascenzioni, Fiorentina; Gilson, Eric

    2014-01-01

    The stability of mammalian telomeres depends upon TRF2, which prevents inappropriate repair and checkpoint activation. By using a plasmid integration assay in yeasts carrying humanized telomeres, we demonstrated that TRF2 possesses the intrinsic property to both stimulate initial homologous recombination events and to prevent their resolution via its basic N-terminal domain. In human cells, we further showed that this TRF2 domain prevents telomere shortening mediated by the resolvase-associated protein SLX4 as well as GEN1 and MUS81, 2 different types of endonucleases with resolvase activities. We propose that various types of resolvase activities are kept in check by the basic N-terminal domain of TRF2 in order to favor an accurate repair of the stalled forks that occur during telomere replication.

  5. Recombinant Production of Human Aquaporin-1 to an Exceptional High Membrane Density in Saccharomyces Cerevisiae

    DEFF Research Database (Denmark)

    Bomholt, Julie; Helix Nielsen, Claus; Scharff-Poulsen, Peter

    2014-01-01

    of solutes. Aquaporins constitute a family of physiologically very important integral membrane proteins that are found in all three kingdoms, eubacteria, archaea and eukaryotes. As protein channels, they facilitate passive transport of water across cell membranes. In the present study the yeast Saccharomyces...... cerevisiae was exploited as a host for heterologous expression of human aquaporins. Aquaporin cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human aquaporin was C-terminally tagged with yeast-enhanced GFP to quantify functional expression...... transcription factor and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30oC was due to in vivo mal-folding. Reduction of the expression temperature to 15oC almost completely...

  6. Preparation and validation of radio iodinated recombinant human IL-10 for the measurement of natural human antibodies against IL-10

    DEFF Research Database (Denmark)

    de Lemos Rieper, Carina; Galle, Pia; Svenson, Morten

    2009-01-01

    Radio iodinated recombinant human IL-10 was prepared and validated for the measurement of natural human anti-IL-10 antibodies. Iodination of IL-10 was accomplished by means of the chloramine-T method. The crude tracer was purified by size chromatography as homo-dimeric IL-10 with a specific...... activity of 75 cpm/pg. Validation of the tracer confirmed preserved antibody epitopes and receptor binding ability. A robust Radio Immuno Assay (RIA) was developed and validated to detect natural human anti-IL-10 antibodies based on the formation of (125)I-labeled IL-10-IgG complexes in solution...... and separation of the complexes by chromatography on mini-columns. The RIA was applied to 3360 plasma samples derived from normal Danish blood donors. Generally, IL-10 did not bind to plasma factors other than natural anti-IL-10 IgG antibodies. The prevalence of donors high positive for antibodies against IL-10...

  7. Expression and characterization of bioactive recombinant human alpha-lactalbumin in the milk of transgenic cloned cows.

    Science.gov (United States)

    Wang, J; Yang, P; Tang, B; Sun, X; Zhang, R; Guo, C; Gong, G; Liu, Y; Li, R; Zhang, L; Dai, Y; Li, N

    2008-12-01

    Improvement of the nutritional value of cow milk with transgenic expression of recombinant human alpha-lactalbumin (alpha-LA) has been previously attempted. However, the detailed characterization of the recombinant protein and analysis of the transgenic milk components are not explored yet. Here, we first report production of healthy transgenic cows by somatic cell nuclear transfer, in which expression of up to 1.55 g/L of recombinant human alpha-LA was achieved. The recombinant human alpha-LA was purified from transgenic milk and displayed physicochemical properties similar to its natural counterpart with respect to molecular weight, structure, and regulatory activity for beta-1,4-galactosyltransferase. Additionally, no N-glycosylation was found in the recombinant human alpha-LA, whereas the endogenous bovine alpha-LA was glycosylated at the unusual site (71)Asn-Ile-(73)Cys. Compared with milk from nontransgenic cows, expression of the transgene did not materially alter milk composition, such as fat and protein content. Our research thus provides scientific evidence supporting the feasibility of humanizing cow milk.

  8. Development and characterization of a pre-treatment procedure to eliminate human monoclonal antibody therapeutic drug and matrix interference in cell-based functional neutralizing antibody assays.

    Science.gov (United States)

    Xu, Weifeng; Jiang, Hao; Titsch, Craig; Haulenbeek, Jonathan R; Pillutla, Renuka C; Aubry, Anne-Françoise; DeSilva, Binodh S; Arnold, Mark E; Zeng, Jianing; Dodge, Robert W

    2015-01-01

    Biological therapeutics can induce an undesirable immune response resulting in the formation of anti-drug antibodies (ADA), including neutralizing antibodies (NAbs). Functional (usually cell-based) NAb assays are preferred to determine NAb presence in patient serum, but are often subject to interferences from numerous serum factors, such as growth factors and disease-related cytokines. Many functional cell-based NAb assays are essentially drug concentration assays that imply the presence of NAbs by the detection of small changes in functional drug concentration. Any drug contained in the test sample will increase the total amount of drug in the assay, thus reducing the sensitivity of NAb detection. Biotin-drug Extraction with Acid Dissociation (BEAD) has been successfully applied to extract ADA, thereby removing drug and other interfering factors from human serum samples. However, to date there has been no report to estimate the residual drug level after BEAD treatment when the drug itself is a human monoclonal antibody; mainly due to the limitation of traditional ligand-binding assays. Here we describe a universal BEAD optimization procedure for human monoclonal antibody (mAb) drugs by using a LC-MS/MS method to simultaneously measure drug (a mutant human IgG4), NAb positive control (a mouse IgG), and endogenous human IgGs as an indicator of nonspecific carry-over in the BEAD eluate. This is the first report demonstrating that residual human mAb drug level in clinical sample can be measured after BEAD pre-treatment, which is critical for further BEAD procedure optimization and downstream immunogenicity testing. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Clearance kinetics and external dosimetry of 131I-labeled murine and humanized monoclonal antibody A33 in patients with colon cancer: radiation safety implications.

    Science.gov (United States)

    Dauer, Lawrence T; Boylan, Daniel C; Williamson, Matthew J; St Germain, Jean; Larson, Steven M

    2009-05-01

    The monoclonal antibody (mAb) A33 detects a membrane antigen that is expressed on greater than 95% of metastatic human colorectal cancers. Previous studies have shown excellent tumor-targeting of (131)I-labeled murine and humanized forms of the mAb. A retrospective analysis of whole-body clearance in the murine form was performed for comparison to the humanized form. Serial whole-body dose rate measurements were obtained for 55 treatments on 30 patients participating in phase I/II dose escalation studies of therapeutic (131)I-murine A33 mAb. Whole-body retention fractions over time were derived. Each treatment was fit with exponential curves to determine the effective half-lives and corresponding clearance fractions. There was a large variability in the calculated mono-exponential clearance effective half-life time, with a mean value of 36.5 h +/- 8.5 h. A bi-exponential fit of all combined data shows that 60% of the administered dose rapidly clears with a biological half-time of 23.9 h and 40% clears with a slower biological half-time of 101.2 h. The whole-body clearance proved to be more rapid in the murine form when compared with recent studies on the humanized form of radiolabeled A33 mAb. The variability in whole-body clearance reinforces the need for patient-specific tracer dosimetry for clinical care and radiation safety precautions. In addition, the slower clearance of the humanized form of the A33 mAb requires longer term radiation safety precautions than the earlier murine form. As other monoclonal antibodies progress from murine to humanized forms, radiopharmacokinetics should be evaluated for clinical and radiation safety implications.

  10. IMC-A12, a human IgG1 monoclonal antibody to the insulin-like growth factor I receptor.

    Science.gov (United States)

    Rowinsky, Eric K; Youssoufian, Hagop; Tonra, James R; Solomon, Phillip; Burtrum, Douglas; Ludwig, Dale L

    2007-09-15

    Targeted monoclonal antibody therapy is an important strategy in cancer therapeutics. Among the most promising characteristics of therapeutic targets are those that modulate the growth and survival of malignant neoplasms and their sensitivity to anticancer therapies. The insulin-like growth factor-I receptor (IGF-IR) is overexpressed in many types of solid and hematopoietic malignancies, and has been implicated as a principal cause of heightened proliferative and survival signaling. IGF-IR has also been shown to confer resistance to cytotoxic, hormonal, and targeted therapies, suggesting that therapeutics targeting IGF-IR may be effective against a broad range of malignancies. IMC-A12 (ImClone Systems Incorporated), a fully human monoclonal IgG1 antibody that binds with high affinity to the IGF-IR, inhibits ligand-dependent receptor activation and downstream signaling. IMC-A12 also mediates robust internalization and degradation of the IGF-IR. In human tumor xenograft models, IGF-IR blockade by IMC-A12 results in rapid and profound growth inhibition of cancers of the breast, lung, colon, and pancreas, and many other neoplasms. Although promising single-agent activity has been observed, the most impressive effects of targeting the IGF-IR with IMC-A12 have been noted when this agent was combined with cytotoxic agents or other targeted therapeutics. The results with IMC-A12 to date suggest that it may be an effective therapeutic in a diverse array of oncologic indications.

  11. Recombinant Human Myelin-Associated Glycoprotein Promoter Drives Selective AAV-Mediated Transgene Expression in Oligodendrocytes.

    Science.gov (United States)

    von Jonquieres, Georg; Fröhlich, Dominik; Klugmann, Claudia B; Wen, Xin; Harasta, Anne E; Ramkumar, Roshini; Spencer, Ziggy H T; Housley, Gary D; Klugmann, Matthias

    2016-01-01

    Leukodystrophies are hereditary central white matter disorders caused by oligodendrocyte dysfunction. Recent clinical trials for some of these devastating neurological conditions have employed an ex vivo gene therapy approach that showed improved endpoints because cross-correction of affected myelin-forming cells occurred following secretion of therapeutic proteins by transduced autologous grafts. However, direct gene transfer to oligodendrocytes is required for the majority of leukodystrophies with underlying mutations in genes encoding non-secreted oligodendroglial proteins. Recombinant adeno-associated viral (AAV) vectors are versatile tools for gene transfer to the central nervous system (CNS) and proof-of-concept studies in rodents have shown that the use of cellular promoters is sufficient to target AAV-mediated transgene expression to glia. The potential of this strategy has not been exploited. The major caveat of the AAV system is its limited packaging capacity of ~5 kb, providing the rationale for identifying small yet selective recombinant promoters. Here, we characterize the human myelin associated glycoprotein (MAG) promoter for reliable targeting of AAV-mediated transgene expression to oligodendrocytes in vivo. A homology screen revealed highly conserved genomic regions among mammalian species upstream of the transcription start site. Recombinant AAV expression cassettes carrying the cDNA encoding enhanced green fluorescent protein (GFP) driven by truncated versions of the recombinant MAG promoter (2.2, 1.5 and 0.3 kb in size) were packaged as cy5 vectors and delivered into the dorsal striatum of mice. At 3 weeks post-injection, oligodendrocytes, neurons and astrocytes expressing the reporter were quantified by immunohistochemical staining. Our results revealed that both 2.2 and 1.5 kb MAG promoters targeted more than 95% of transgene expression to oligodendrocytes. Even the short 0.3 kb fragment conveyed high oligodendroglial specific transgene

  12. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

    Science.gov (United States)

    Dolinska, Monika B; Kovaleva, Elena; Backlund, Peter; Wingfield, Paul T; Brooks, Brian P; Sergeev, Yuri V

    2014-01-01

    Tyrosinase (TYR) catalyzes the rate-limiting, first step in melanin production and its gene (TYR) is mutated in many cases of oculocutaneous albinism (OCA1), an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes. The intra-melanosomal domain of human tyrosinase (residues 19-469) and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure. The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

  13. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

    Directory of Open Access Journals (Sweden)

    Monika B Dolinska

    Full Text Available Tyrosinase (TYR catalyzes the rate-limiting, first step in melanin production and its gene (TYR is mutated in many cases of oculocutaneous albinism (OCA1, an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes.The intra-melanosomal domain of human tyrosinase (residues 19-469 and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure.The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

  14. Population Pharmacokinetic Modelling of FE 999049, a Recombinant Human Follicle-Stimulating Hormone, in Healthy Women After Single Ascending Doses

    DEFF Research Database (Denmark)

    Rose, Trine Høyer; Röshammar, Daniel; Erichsen, Lars

    2016-01-01

    Objective: The purpose of this analysis was to develop a population pharmacokinetic model for a novel recombinant human follicle-stimulating hormone (FSH) (FE 999049) expressed from a human cell line of foetal retinal origin (PER.C6) developed for controlled ovarian stimulation prior to assisted...

  15. In vivo synergy between recombinant human stem cell factor and recombinant human granulocyte colony-stimulating factor in baboons enhanced circulation of progenitor cells.

    Science.gov (United States)

    Andrews, R G; Briddell, R A; Knitter, G H; Opie, T; Bronsden, M; Myerson, D; Appelbaum, F R; McNiece, I K

    1994-08-01

    Recombinant human stem cell factor (rhSCF) and recombinant human granulocyte colony-stimulating factor (rhG-CSF) are synergistic in vitro in stimulating the proliferation of hematopoietic progenitor cells and their precursors. We examined the in vivo synergy of rhSCF with rhG-CSF for stimulating hematopoiesis in vivo in baboons. Administration of low-dose (LD) rhSCF (25 micrograms/kg) alone did not stimulate changes in circulating WBCs. In comparison, administration of LD rhSCF in combination with rhG-CSF at 10 micrograms/kg or 100 micrograms/kg stimulated increases in circulating WBCs of multiple types up to twofold higher than was stimulated by administration of the same dose of rhG-CSF alone. When the dose of rhG-CSF is increased to 250 micrograms/kg, the administration of LD rhSCF does not further increase the circulating WBC counts. Administration of LD rhSCF in combination with rhG-CSF also stimulated increased circulation of hematopoietic progenitors. LD rhSCF alone stimulated less of an increase in circulating progenitors, per milliliter of blood, than did administration of rhG-CSF alone at 100 micrograms/kg. Baboons administered LD rhSCF together with rhG-CSF at 10, 100, or 250 micrograms/kg had 3.5- to 16-fold higher numbers per milliliter of blood of progenitors cells of multiple types, including colony-forming units granulocyte/macrophage (CFU-GM), burst-forming unit-erythroid (BFU-E), and colony-forming and burst-forming units-megakaryocyte (CFU-MK and BFU-MK) compared with animals given the same dose of rhG-CSF without rhSCF, regardless of the rhG-CSF dose. The increased circulation of progenitor cells stimulated by the combination of rhSCF plus rhG-CSF was not necessarily directly related to the increase in WBCs, as this effect on peripheral blood progenitors was observed even at an rhG-CSF dose of 250 micrograms/kg, where coadministration of LD rhSCF did not further increase WBC counts. Administration of very-low-dose rhSCF (2.5 micrograms/kg) with

  16. Evidence for Within-Host Genetic Recombination among the Human Pegiviral Strains in HIV Infected Subjects.

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    Haoming Wu

    Full Text Available The non-pathogenic Human Pegivirus (HPgV, formerly GBV-C/HGV, the most prevalent RNA virus worldwide, is known to be associated with reduced morbidity and mortality in HIV-infected individuals. Although previous studies documented its ubiquity and important role in HIV-infected individuals, little is known about the underlying genetic mechanisms that maintain high genetic diversity of HPgV within the HIV-infected individuals. To assess the within-host genetic diversity of HPgV and forces that maintain such diversity within the co-infected hosts, we performed phylogenetic analyses taking into account 229 HPgV partial E1-E2 clonal sequences representing 15 male and 8 female co-infected HIV patients from Hubei province of central China. Our results revealed the presence of eleven strongly supported clades. While nine clades belonged to genotype 3, two clades belonged to genotype 2. Additionally, four clades that belonged to genotype 3 exhibited inter-clade recombination events. The presence of clonal sequences representing multiple clades within the HIV-infected individual provided the evidence of co-circulation of HPgV strains across the region. Of the 23 patients, six patients (i.e., five males and one female were detected to have HPgV recombinant sequences. Our results also revealed that while male patients shared the viral strains with other patients, viral strains from the female patients had restricted dispersal. Taken together, the present study revealed that multiple infections with divergent HPgV viral strains may have caused within-host genetic recombination, predominantly in male patients, and therefore, could be the major driver in shaping genetic diversity of HPgV.

  17. Recombinant human proinsulin from transgenic corn endosperm: solvent screening and extraction studies

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    C. S. Farinas

    2007-09-01

    Full Text Available Recombinant pharmaceutical proteins are being produced in different systems such as bacteria and mammalian cell cultures. The use of transgenic plants as bioreactors has recently arisen as an alternative system offering many practical and economic advantages. However, finding an optimum strategy for the downstream processing (DSP of recombinant proteins from plants still remains a challenge. In this work, we studied the extraction of recombinant human proinsulin (rhProinsulin produced in the endosperm of transgenic corn seeds. An efficient extraction solvent was selected and the effects of temperature, solvent-to-solid ratio, time, and impeller rotational speed on the extraction were evaluated using an experimental design. After an extraction kinetics study, temperature was further evaluated to maximize rhProinsulin concentration in the extracts and to minimize the native corn components carbohydrates, phenolic compounds, and proteins. A high efficiency condition for extracting rhProinsulin with the selected solvent - 50 mM sodium bicarbonate buffer pH 10.0 and 5 mM DTT - was an extraction time of 2 h at a solvent-to-solid ratio of 10:1 and 25º C. The maximum rhProinsulin concentration in the extracts at that condition was 18.87 mg l-1 or 0.42% of the total soluble protein. These values are within the range in which the production of pharmaceutical proteins in plants can be competitive with other expression systems. The results presented provide information for the development of an additional production platform for the hormone insulin.

  18. Phage Display Approaches for the Isolation of Monoclonal Antibodies Against Dengue Virus Envelope Domain III from Human and Mouse Derived Libraries

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    Subhash G. Vasudevan

    2012-02-01

    Full Text Available Domain III of the dengue virus envelope protein (EDIII, aa295-395 has an immunoglobulin fold and is the proposed receptor-binding domain of the virus. Previous studies have shown that monoclonal antibodies against EDIII can be neutralizing and have therapeutic potential. Here, cloned Fab-phage libraries of human and mouse origin were screened for DENV specific antibodies. Firstly, bacterially expressed EDIII or whole virus particles were used as bait in biopanning against a large naïve human Fab-phage library ( > 10 billion independent clones. Multiple panning strategies were employed, and in excess of 1000 clones were screened, but all of the antibodies identified bound the envelope in regions outside EDIII suggesting EDIII antibodies are virtually absent from the naïve human repertoire. Next, a chimeric Fab-phage library was constructed from a panel of EDIII specific mouse hybridomas by pooling the VH and VL chain sequences from the hybridomas and cloning these into the pComb3X phagemid vector with human CH and CL encoding sequences. Biopanning against EDIII identified a unique antibody (C9 that cross-reacts with EDIII from DENV1-3 and, in the IgG format, binds and neutralizes DENV2 in cell-based assays. Sequence analysis and saturation mutagenesis of complementary determining regions (CDR in the C9 light chain suggest an antigen recognition model in which the LCDR3 is a key determinant of EDIII specificity, while modifications in LCDR1 and LCDR2 affect DENV serotype cross-reactivity. Overall, this study supports the current prevailing opinion that neutralizing anti-EDIII monoclonal antibodies can be readily generated in murine systems, but in humans the anti-DENV immune response is directed away from domain III.

  19. Antibody humanization methods for development of therapeutic applications.

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    Ahmadzadeh, Vahideh; Farajnia, Safar; Feizi, Mohammad Ali Hosseinpour; Nejad, Ramezan Ali Khavari

    2014-04-01

    Recombinant antibody technologies are rapidly becoming available and showing considerable clinical success. However, the immunogenicity of murine-derived monoclonal antibodies is restrictive in cancer immunotherapy. Humanized antibodies can overcome these problems and are considered to be a promising alternative therapeutic agent. There are several approaches for antibody humanization. In this article we review various methods used in the antibody humanization process.

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

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    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.