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Sample records for human antibody production

  1. Production of Monoclonal Antibody against Human Nestin.

    Science.gov (United States)

    Hadavi, Reza; Zarnani, Amir Hassan; Ahmadvand, Negah; Mahmoudi, Ahmad Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Sadeghi, Mohammad-Reza; Soltanghoraee, Haleh; Akhondi, Mohammad Mehdi; Tarahomi, Majid; Jeddi-Tehrani, Mahmood; Rabbani, Hodjattallah

    2010-04-01

    We have employed a peptide-based antibody generation protocol for producing antibody against human nestin. Using a 12-mer synthetic peptide from repetitive region of human nestin protein devoid of any N- or O-glyco-sylation sequences, we generated a mouse monoclonal antibody capable of recognizing human, mouse, bovine, and rat nestin. A wide variety of nestin proteins ranging from 140-250 kDa was detected by this antibody. This antibody is highly specific and functional in applications such as ELISA, flow cytometry, immunocytochemistry, and Western blot assays.

  2. Monoclonal Antibody Production against Human Spermatozoal Surface Antigens

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    M Jedi-Tehrani

    2005-10-01

    Full Text Available Introduction: As monoclonal antibodies are potential tools for characterization of soluble or cellular surface antigens, use of these proteins has always been considered in infertility and reproduction research. Therefore, in this study, monoclonal antibodies against human sperm surface antigens were produced. Material and Methods: To produce specific clones against human sperm surface antigens, proteins were extracted using solubilization methods. Balb/c mice were immunized intraperitoneally with the proteins using complete Freund’s adjuvant in the first injection and incomplete Adjuvant in the following booster injections. Hybridoma cells producing ASA were cloned by limiting dilution. Results: Five stable ASA producing hybridoma clones were achieved and their antibody isotypes were determined by ELISA. All the isotypes were of IgG class. Their cross reactivity with rat and mice spermatozoa was examined but they did not have any cross reactivity. Conclusion: The produced antibodies can be used in further studies to characterize and evaluate each of the antigens present on human sperm surface and determining their role in fertilization.

  3. Production of Potent Fully Human Polyclonal Antibodies Against Zaire Ebola Virus in Transchromosomal Cattle

    Science.gov (United States)

    2016-07-01

    1 Production of potent fully human polyclonal antibodies against Zaire Ebola virus in transchromosomal cattle John M. Dye1, Hua Wu2, Jay...mail: jjiao@sabbiotherapeutics.com Keywords: Ebola virus, virus neutralization assay, human polyclonal antibodies, transchromosomal bovine...recombinant glycoprotein (GP) vaccine consisting of the 2014 Ebola virus (EBOV)-Makona isolate. Serum collected from these hyperimmunized Tc

  4. Production of monoclonal antibodies to human glomerular basement membrane.

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    Mino,Yasuaki

    1984-10-01

    Full Text Available Using the technique of somatic cell fusion, we produced monoclonal antibodies to collagenase-digested human glomerular basement membrane (GBM. Fourteen monoclonal antibodies which reacted with normal human kidney in indirect immunofluorescence (IIF studies were produced. An analysis of the binding patterns indicated that the antigens recognized could be divided into six broad groups. Monoclonal antibody B3-H10 (Group 1 reacted with only GBM in a fine granular pattern. A5-B12 and B5-C2 (Group 2 reacted with GBM and peritubular capillary in a linear pattern. B2-A12 (Group 3 reacted with only epithelial cells. Al-C9 and A4-E2 (Group 4 showed a mesangial pattern in glomerulus and a lineal pattern in tubular basement membrane (TBM, Bowman's capsule and peritubular capillary. A1-E1, A1-E11, A2-E6, A3-B6, A4-F8 and B5-H2 (Group 5 recognized determinants common to GBM, TBM, Bowman's capsule and/or peritubular capillary. A3-F1 and B5-E10 (Group 6 reacted with TBM and Bowman's capsule. The staining pattern of B3-H10 (Group 1 was characteristic because it was not linear, but finely granular along the GBM. The staining pattern of B2-A12 (Group 3 was also characteristic because only epithelial cells were stained, and processes of epithelial cells were observed as fine fibrils. To the best of our knowledge, these two types of monoclonal antibodies have not been reported previously.

  5. Production and Characterization of Monoclonal Antibody Against Recombinant Human Erythropoietin

    Institute of Scientific and Technical Information of China (English)

    JIE-BO MI; JIN YAN; XIAO-JIE DING; ZHEN-QUAN GUO; MEI-PING ZHAO; WEN-BAO CHANG

    2007-01-01

    Objective To produce specific monoclonal antibody(mAb)against recombinant human erythropoietin(rHuEPO)for development of higmy efficient methods for erythropoietin detection in biological fluids.Methods rHuEPO was covalently coupled with bovine serum albumin(BSA)and the conjugate was used to immunize mice to produce specific mAb against rHuEPO based on hybridoma technology.The obtained F3-mAb was characterized by enzyme-linked immunosorbent assay (ELISA),SDS-PAGE and Western blot.Results The isotype of F3-mAb Was found to be IgM with an affinity constant of 2.1x108 L/mol.The competitive ELISA using the obtained IgM showed a broader linear range and lower detection limit compared with previous work.Conclusions The modification of rHuEPO was proved to be successful in generating required specific mAb with high avidity to rHuEPO.

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

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    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

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  8. Production of the Polyclonal Anti-human Metallothionein 2A Antibody with Recombinant Protein Technology

    Institute of Scientific and Technical Information of China (English)

    Faiz M.M.T.MARIKAR; Qi-Ming SUN; Zi-Chun HUA

    2006-01-01

    Metallothionein 2A (MT2A) is a small stress response protein that can be induced by exposure to toxic metals. It is highly expressed in breast cancer cells. In this study, the eDNA encoding the human MT2A protein was expressed as glutathione S-transferase (GST) fusion protein in Escherichia coli.Recombinant MT2A proteins were loaded onto 12% sodium dodecylsulfate-polyacrylamide gel and separated by electrophoresis, the recombinant protein was visualized by Coomassie blue staining and the 33 kDa recombinant GST-MT2A fusion protein band was cut out from the gel. The gel slice was minced and used to generate polyclonal antisera. Immunization of rabbit against MT2A protein allowed the production of high titer polyclonal antiserum. This new polyclonal antibody recognized recombinant MT2A protein in Western blot analysis. This low-cost antibody will be useful for detection in various immuno-assays.

  9. Production and characterization of antibodies against irradiated human erythrocytes membrane proteins

    Energy Technology Data Exchange (ETDEWEB)

    Amancio, Francisco F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]|[Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia; Andrade Junior, Heitor F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Inst. de Medicina Tropical

    1997-12-01

    Gamma irradiation affects people in several situations, with few if any sensitive biological assay of its action. Nucleic acids and proteins are affected by radiation, but only the former was used in most dosimetric techniques. The irradiation of proteins promotes structural modifications attributed to free radicals from water radiolysis. Theoretically, antibodies induced by irradiated proteins could recognize these radical-related new epitopes, allowing their use as a probe. Human erythrocyte membrane proteins (HEMP), few and well defined molecules, are certainly exposed to radiation, being the ideal target. With this rationale, we study the production of antibodies in mice immunized with {sup 60} Co irradiated HEMPs. Menbranes from hypotonic lysis with differential centrifugation of A+ erythrocytes, were irradiated in a Gammacell 220 with 400, 800 and 1600 Gy, and used as immunogen for Balb/c mice, after SDS-PAGE. Irradiated HEMP induced antibodies recognize only irradiated human erthrocytes in an intact cell indirect immunofluorescence assay (ICIIFA). When used in Wester-blot against non-irradiated HEMPs, those sera recognize most proteins, suggesting a pool of abs directed both to native, as detected by Western Blot, or irradiated, as detected by ICIFA, HEMPs. Those data confirmed our assumptions, allowing the use of those abs in the search for a method of biological dosimetry. (author). 18 refs., 3 figs.

  10. Human anti-mouse antibodies.

    Science.gov (United States)

    Klee, G G

    2000-06-01

    Human anti-mouse antibodies (HAMA) are human immunoglobulins with specificity for mouse immunoglobulins. This topic currently is of interest because of the increased use of monoclonal mouse antibodies as diagnostic reagents both for in vitro laboratory measurements and for in vivo imaging studies. Monoclonal mouse antibodies also are being used therapeutically. This short article reviews the production of HAMA in patients receiving monoclonal antibodies and illustrates the potential ways that HAMA can interfere with immunoassay measurements. Methods for measuring and neutralizing HAMA also are discussed.

  11. Radioimmunoassay for zearalenone and zearalanol in human serum: production, properties, and use of porcine antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Thouvenot, D.; Morfin, R.F.

    1983-01-01

    To produce antigens susceptible to raise antibodies for resorcylic acid lactones, the 6'-carboxymethyloxime derivatives of zearalenone and zearalanone were bound to bovine serum albumin. Pigs could be immunized by using these antigens, the best titer in antibodies being obtained with the zearalenone antigen. The procine antibodies were specific for the resorcylic acid lactones of structural resemblance with zearalenone. This specificity made the antibodies usable for a radioimmunoassay of zearalenone and zearalanol, which may be found in human and animal sera. The range of the assay was between 0.25 and 10 ng. The limit of detection was 5 ppb (5 ng/ml) in human serum.

  12. Species-Specific Chromosome Engineering Greatly Improves Fully Human Polyclonal Antibody Production Profile in Cattle.

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    Hiroaki Matsushita

    Full Text Available Large-scale production of fully human IgG (hIgG or human polyclonal antibodies (hpAbs by transgenic animals could be useful for human therapy. However, production level of hpAbs in transgenic animals is generally very low, probably due to the fact that evolutionarily unique interspecies-incompatible genomic sequences between human and non-human host species may impede high production of fully hIgG in the non-human environment. To address this issue, we performed species-specific human artificial chromosome (HAC engineering and tested these engineered HAC in cattle. Our previous study has demonstrated that site-specific genomic chimerization of pre-B cell receptor/B cell receptor (pre-BCR/BCR components on HAC vectors significantly improves human IgG expression in cattle where the endogenous bovine immunoglobulin genes were knocked out. In this report, hIgG1 class switch regulatory elements were subjected to site-specific genomic chimerization on HAC vectors to further enhance hIgG expression and improve hIgG subclass distribution in cattle. These species-specific modifications in a chromosome scale resulted in much higher production levels of fully hIgG of up to 15 g/L in sera or plasma, the highest ever reported for a transgenic animal system. Transchromosomic (Tc cattle containing engineered HAC vectors generated hpAbs with high titers against human-origin antigens following immunization. This study clearly demonstrates that species-specific sequence differences in pre-BCR/BCR components and IgG1 class switch regulatory elements between human and bovine are indeed functionally distinct across the two species, and therefore, are responsible for low production of fully hIgG in our early versions of Tc cattle. The high production levels of fully hIgG with hIgG1 subclass dominancy in a large farm animal species achieved here is an important milestone towards broad therapeutic applications of hpAbs.

  13. Polyclonal antibody production and expression of CREG protein in human vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Yaling HAN; Haiwei LIU; Jian KANG; Xiaozeng WANG; Ye HU; Lianyou ZHAO; Shaohua LI

    2005-01-01

    Objectives The cellular repressor of E1A-activated genes (CREG), a novel gene, was recently found to play a role in inhibiting cell growth and promoting cell differentiation. The purpose of this study was to obtain antibody against CREG protein and to study the expression of CREG protein in human internal thoracic artery cells (HITASY) which express different patterns of differentiation markers after serum withdrawal. Methods The open reading frame of CREG gene sequence was amplified by PCR and cloned into the pGEX-4T-1 vector. Glutathione-S-transferase (GST)-CREG fusion protein was expressed in E. Coli BL21 and purified from inclusion bodies by Sephacryl S-200 chromatography. Rabbits were immunized with the purified GST-CREG protein. Western blot examined with immunohistochemistry staining and the protein expression level was analyzed by Western blot in HITASY cells after serum removal. Results It was confirmed by using endonuclease digesting and DNA sequencing that the PCR product of CREG was correctly inserted into the vector. The GST-CREG protein was purified with gel filtration chromatography. Polyclonal antibody against GST-CREG was obtained from rabbits. CREG protein immunohistochemistry staining displayed a perinuclear distribution in the cytoplasm of HITASY cells. Results from Western blot suggested that comparing with the untreated cells upregulation of CREG polyclonal antibody against CREG was comfirmed. Using this antibody, the changes of CREG protein expression was observed in the process of phenotypic modulation of HITASY cells. These results provide basic understanding on the relationship of CREG gene with the cell phenotypic conversion.

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  15. Production of neutralizing monoclonal antibody against human vascular endothelial growth factor receptor Ⅱ

    Institute of Scientific and Technical Information of China (English)

    Rong LI; Dong-sheng XIONG; Xiao-feng SHAO; Jia LIU; Yuan-fu XU; Yuan-sheng XU; Han-zhi LIU; Zhen-ping ZHU; Chun-zheng YANG

    2004-01-01

    AIM: To prepare neutralizing monoclonal antibody (mAb) against extracellular immunoglobulin (Ig)-like domainⅢ of vascular endothelial growth factor receptor KDR and study its biological activity. METHODS: Soluble KDR Ig domain Ⅲ (KDR-Ⅲ) fusion protein was expressed in E Coli and purified from the bacterial periplasmic extracts via an affinity chromatography. Monoclonal antibodies against KDR-Ⅲ were prepared by hybridoma technique. ELISA and FACS analysis were used to identify its specificity. Immunoprecipitation and [3H]-thymidine incorporation assay were also used to detect the activity of anti-KDR mAb blocking the phosphorylation of KDR tyrosine kinase receptor and the influence on vascular endothelial growth factor-induced mitogenesis of human endothelial ceils.RESULTS: A monoclonal antibody, Ycom1D3 (IgG1), was generated from a mouse immunized with the recombinant KDR-Ⅲ protein. Ycom1D3 bound specifically to both the soluble KDR-Ⅲ and the cell-surface expressed KDR. Ycom1D3 effectively blocked VEGF/KDR interaction and inhibited VEGF-stimulated KDR activation in human endothelial cells. Furthermore, the antibody efficiently neutralized VEGF-induced mitogenesis of human endothelial cells. CONCLUSION: Our results suggest that the anti-KDR mAb, Ycom1D3, has potential applications in the treatment of cancer and other diseases where pathological angiogenesis is involved.

  16. Production and characterisation of a monoclonal antibody to human papillomavirus type 16 using recombinant vaccinia virus.

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    McLean, C S; Churcher, M J; Meinke, J; Smith, G L; Higgins, G; Stanley, M; Minson, A C

    1990-06-01

    A monoclonal antibody was raised against the major capsid protein L1 of human papillomavirus type 16, using a recombinant vaccinia virus that expresses the L1 protein, as a target for screening. This antibody, designated CAMVIR-1, reacted with a 56 kilodalton protein in cells infected with L1-vaccinia virus, and the protein was present in a predominantly nuclear location. The antibody also detects the HPV-16 L1 antigen in formalin fixed, paraffin wax embedded biopsy specimens and on routine cervical smears. The antibody reacts strongly and consistently with biopsy specimens containing HPV-16 or HPV-33, but very weak reactions were occasionally observed with biopsy specimens or smears containing HPV-6 or HPV-11. The potential advantages of using a vaccinia recombinant are (i) the target protein is synthesised in a eukoryotic cell so that its "processing" and location are normal; (ii) cells infected with vaccinia recombinants can be subjected to various fixing procedures similar to those used for routine clinical material. This greatly increases the probability that an identified antibody will be useful in a clinical setting.

  17. Production and characterisation of monoclonal antibodies against RAI3 and its expression in human breast cancer

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    Kiefer Hans

    2009-06-01

    Full Text Available Abstract Background RAI3 is an orphan G-protein coupled receptor (GPCR that has been associated with malignancy and may play a role in the proliferation of breast cancer cells. Although its exact function in normal and malignant cells remains unclear and evidence supporting its role in oncogenesis is controversial, its abundant expression on the surface of cancer cells would make it an interesting target for the development of antibody-based therapeutics. To investigate the link with cancer and provide more evidence for its role, we carried out a systematic analysis of RAI3 expression in a large set of human breast cancer specimens. Methods We expressed recombinant human RAI3 in bacteria and reconstituted the purified protein in liposomes to raise monoclonal antibodies using classical hybridoma techniques. The specific binding activity of the antibodies was confirmed by enzyme-linked immunosorbent assay (ELISA, western blot and immunocytochemistry. We carried out a systematic immunohistochemical analysis of RAI3 expression in human invasive breast carcinomas (n = 147 and normal breast tissues (n = 44 using a tissue microarray. In addition, a cDNA dot blot hybridisation assay was used to investigate a set of matched normal and cancerous breast tissue specimens (n = 50 as well as lymph node metastases (n = 3 for RAI3 mRNA expression. Results The anti-RAI3 monoclonal antibodies bound to recombinant human RAI3 protein with high specificity and affinity, as shown by ELISA, western blot and ICC. The cDNA dot blot and immunohistochemical experiments showed that both RAI3 mRNA and RAI3 protein were abundantly expressed in human breast carcinoma. However, there was no association between RAI3 protein expression and prognosis based on overall and recurrence-free survival. Conclusion We have generated a novel, highly-specific monoclonal antibody that detects RAI3 in formaldehyde-fixed paraffin-embedded tissue. This is the first study to report a systematic

  18. Production of a human single-chain variable fragment antibody against esophageal carcinoma

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    Ming-Yan Xu; Xiao-Hu Xu; Geng-Zhen Chen; Xiao-Ling Deng; Jonathan Li; Xiao-Jun Yu; Mei-Zhen Chen

    2004-01-01

    AIM: To construct a phage display library of human singlechain variable fragment (scFv) antibodies associated with esophageal cancer and to preliminarily screen a scFv antibody against esophageal cancer.METHODS: Total RNA extracted from metastatic lymph nodes of esophageal cancer patients was used to construct a scFv gene library. Rescued by M13K07 helper phage, the scFv phage display library was constructed. esophageal cancer cell line Eca 109 and normal human esophageal epithelial cell line (NHEEC) were used for panning and subtractive panning of the scFv phage display library to obtain positive phage clones. Soluble scFv was expressed in E.coli HB2151 which was transfected with the positive phage clone, then purified by affinity chromatography.Relative molecular mass of soluble scFv was estimated by Western blotting, its bioactivity was detected by cell ELISA assay. Sequence of scFv was determined using the method of dideoxynucleotide sequencing.RESULTS: The size of scFv gene library was approximately 9×106 clones. After four rounds of panning with Eca109 and three rounds of subtractive panning with NHEEC cells, 25 positive phage clones were obtained. Soluble scFv was found to have a molecular mass of 31 ku and was able to bind to Eca109 cells, but not to HeLa and NHEEC cells. Variable heavy (VH) gene from one of the positive clones was shown to be derived from the γ chain subgroup Ⅳ of immunoglobulin, and variable light (VL) gene from the κchain subgroup I of immunoglobulin.CONCLUSION: A human scFv phage display library can be constructed from the metastatic lymph nodes of esophageal cancer patients. A whole human scFv against esophageal cancer shows some bioactivity.

  19. Plant production of anti-β-glucan antibodies for immunotherapy of fungal infections in humans.

    Science.gov (United States)

    Capodicasa, Cristina; Chiani, Paola; Bromuro, Carla; De Bernardis, Flavia; Catellani, Marcello; Palma, Angelina S; Liu, Yan; Feizi, Ten; Cassone, Antonio; Benvenuto, Eugenio; Torosantucci, Antonella

    2011-09-01

    There is an increasing interest in the development of therapeutic antibodies (Ab) to improve the control of fungal pathogens, but none of these reagents is available for clinical use. We previously described a murine monoclonal antibody (mAb 2G8) targeting β-glucan, a cell wall polysaccharide common to most pathogenic fungi, which conferred significant protection against Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans in animal models. Transfer of this wide-spectrum, antifungal mAb into the clinical setting would allow the control of most frequent fungal infections in many different categories of patients. To this aim, two chimeric mouse-human Ab derivatives from mAb 2G8, in the format of complete IgG or scFv-Fc, were generated, transiently expressed in Nicotiana benthamiana plants and purified from leaves with high yields (approximately 50 mg Ab/kg of plant tissues). Both recombinant Abs fully retained the β-glucan-binding specificity and the antifungal activities of the cognate murine mAb against C. albicans. In fact, they recognized preferentially β1,3-linked glucan molecules present at the fungal cell surface and directly inhibited the growth of C. albicans and its adhesion to human epithelial cells in vitro. In addition, both the IgG and the scFv-Fc promoted C. albicans killing by isolated, human polymorphonuclear neutrophils in ex vivo assays and conferred significant antifungal protection in animal models of systemic or vulvovaginal C. albicans infection. These recombinant Abs represent valuable molecules for developing novel, plant-derived immunotherapeutics against candidiasis and, possibly, other fungal diseases.

  20. Efficient production of human bivalent and trivalent anti-MUC1 Fab-scFv antibodies in Pichia pastoris

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    Haustraete Jurgen

    2009-08-01

    Full Text Available Abstract Background Tumour associated antigens on the surface of tumour cells, such as MUC1, are being used as specific antibody targets for immunotherapy of human malignancies. In order to address the poor penetration of full sized monoclonal antibodies in tumours, intermediate sized antibodies are being developed. The cost-effective and efficient production of these molecules is however crucial for their further success as anti-cancer therapeutics. The methylotropic P. pastoris yeast grows in cheap mineral media and is known for its short process times and the efficient production of recombinant antibody fragments like scFvs, bivalent scFvs and Fabs. Results Based on the anti-MUC1 PH1 Fab, we have developed bivalent PH1 bibodies and trivalent PH1 tribodies of intermediate molecular mass by adding PH1 scFvs to the C-terminus of the Fab chains using flexible peptide linkers. These recombinant antibody derivatives were efficiently expressed in both mammalian and P. pastoris cells. Stable production in NS0 cells produced 130.5 mg pure bibody and 27 mg pure tribody per litre. This high yield is achieved as a result of the high overall purification efficiency of 77%. Expression and purification of PH1 bibodies and tribodies from Pichia supernatant yielded predominantly correctly heterodimerised products, free of light chain homodimers. The yeast-produced bi- and tribodies retained the same specific activity as their mammalian-produced counterparts. Additionally, the yields of 36.8 mg pure bibody and 12 mg pure tribody per litre supernatant make the production of these molecules in Pichia more efficient than most other previously described trispecific or trivalent molecules produced in E. coli. Conclusion Bi- and tribody molecules are efficiently produced in P. pastoris. Furthermore, the yeast produced molecules retain the same specific affinity for their antigen. These results establish the value of P. pastoris as an efficient alternative expression

  1. Production and Characterization of Monoclonal Antibodies against Human Nuclear Protein FAM76B.

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    Xiaojing Zheng

    Full Text Available Human FAM76B (hFAM76B is a 39 kDa protein that contains homopolymeric histidine tracts, a targeting signal for nuclear speckles. FAM76B is highly conserved among different species, suggesting that it may play an important physiological role in normal cellular functions. However, a lack of appropriate tools has hampered study of this potentially important protein. To facilitate research into the biological function(s of FAM76B, murine monoclonal antibodies (MAbs against hFAM76B were generated by using purified, prokaryotically expressed hFAM76B protein. Six strains of MAbs specific for hFAM76B were obtained and characterized. The specificity of MAbs was validated by using FAM76B-/- HEK 293 cell line. Double immunofluorescence followed by laser confocal microscopy confirmed the nuclear speckle localization of hFAM76B, and the specific domains recognized by different MAbs were further elucidated by Western blot. Due to the high conservation of protein sequences between mouse and human FAM76B, MAbs against hFAM76B were shown to react with mouse FAM76B (mFAM76B specifically. Lastly, FAM76B was found to be expressed in the normal tissues of most human organs, though to different extents. The MAbs produced in this study should provide a useful tool for investigating the biological function(s of FAM76B.

  2. Production of a tumour-targeting antibody with a human-compatible glycosylation profile in N. benthamiana hairy root cultures.

    Science.gov (United States)

    Lonoce, Chiara; Salem, Reda; Marusic, Carla; Jutras, Philippe V; Scaloni, Andrea; Salzano, Anna Maria; Lucretti, Sergio; Steinkellner, Herta; Benvenuto, Eugenio; Donini, Marcello

    2016-09-01

    Hairy root (HR) cultures derived from Agrobacterium rhizogenes transformation of plant tissues are an advantageous biotechnological manufacturing platform due to the accumulation of recombinant proteins in an otherwise largely protein free culture medium. In this context, HRs descending from transgenic Nicotiana tabacum plants were successfully used for the production of several functional mAbs with plant-type glycans. Here, we expressed the tumor-targeting monoclonal antibody mAb H10 in HRs obtained either by infecting a transgenic N. tabacum line expressing H10 with A. rhizogenes or a glyco-engineered N. benthamiana line (ΔXTFT) with recombinant A. rhizogenes carrying mAb H10 heavy and light chain cDNAs. Selected HR clones derived from both plants accumulated mAb H10 in the culture medium with similar yields (2-3 mg/L). N-glycosylation profiles of antibodies purified from HR supernatant revealed the presence of plant-typical complex structures for N. tabacum-derived mAb H10 and of GnGn structures lacking xylose and fucose for the ΔXTFT-derived counterpart. Both antibody glyco-formats exhibited comparable antigen binding activities. Collectively, these data demonstrate that the co-infection of ΔXTFT Nicotiana benthamiana with recombinant A. rhizogenes is an efficient procedure for the generation of stable HR cultures expressing the tumor-targeting mAb H10 with a human-compatible glycosylation profile, thus representing an important step towards the exploitation of root cultures for the production of 'next generation' human therapeutic antibodies.

  3. Tabhu: tools for antibody humanization

    DEFF Research Database (Denmark)

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

    2015-01-01

    Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can...... into a suitable human template. Unfortunately, this procedure may results in a partial or complete loss of affinity of the grafted molecule that can be restored by back-mutating some of the residues of human origin to the corresponding murine ones. This trial-and-error procedure is hard and involves expensive...... and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps...

  4. Production and characterization of human anti-V3 monoclonal antibodies from the cells of HIV-1 infected Indian donors

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    Andrabi Raiees

    2012-09-01

    Full Text Available Abstract Background Analysis of human monoclonal antibodies (mAbs developed from HIV-1 infected donors have enormously contributed to the identification of neutralization sensitive epitopes on the HIV-1 envelope glycoprotein. The third variable region (V3 is a crucial target on gp120, primarily due to its involvement in co-receptor (CXCR4 or CCR5 binding and presence of epitopes recognized by broadly neutralizing antibodies. Methods Thirty-three HIV-1 seropositive drug naive patients (18 males and 15 females within the age range of 20–57 years (median = 33 years were recruited in this study for mAb production. The mAbs were selected from EBV transformed cultures with conformationally constrained Cholera-toxin-B containing V3C (V3C-CTB fusion protein. We tested the mAbs for their binding with HIV-1 derived proteins and peptides by ELISA and for neutralization against HIV-1 viruses by TZM-bl assays. Results We isolated three anti-V3 mAbs, 277, 903 and 904 from the cells of different individuals. The ELISA binding revealed a subtype-C and subtype-A specific binding of antibody 277 and 903 while mAb 904 exhibited cross reactivity also with subtype-B V3. Epitope mapping of mAbs with overlapping V3 peptides showed exclusive binding to V3 crown. The antibodies displayed high and low neutralizing activity against 2/5 tier 1 and 1/6 tier 2 viruses respectively. Overall, we observed a resistance of the tier 2 viruses to neutralization by the anti-V3 mAbs, despite the exposure of the epitopes recognized by these antibodies on two representative native viruses (Du156.12 and JRFL, suggesting that the affinity of mAb might equally be crucial for neutralization, as the epitope recognition. Conclusions Our study suggests that the anti-V3 antibodies derived from subtype-C infected Indian patients display neutralization potential against tier 1 viruses while such activity may be limited against more resistant tier 2 viruses. Defining the fine epitope

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

    African Journals Online (AJOL)

    SERVER

    2007-06-18

    Jun 18, 2007 ... that ion-exchange chromatography could be an appropriate method for purification of IgG ... researches, polyclonal antibodies are routinely used as .... production and characterization of anti- human IgG monoclonal antibody ...

  6. Tabhu: tools for antibody humanization.

    KAUST Repository

    Olimpieri, Pier Paolo

    2014-10-09

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

  7. Expression, production, and renaturation of a functional single-chain variable antibody fragment (scFv against human ICAM-1

    Directory of Open Access Journals (Sweden)

    H. Sun

    2014-07-01

    Full Text Available Intercellular adhesion molecule-1 (ICAM-1 is an important factor in the progression of inflammatory responses in vivo. To develop a new anti-inflammatory drug to block the biological activity of ICAM-1, we produced a monoclonal antibody (Ka=4.19×10−8 M against human ICAM-1. The anti-ICAM-1 single-chain variable antibody fragment (scFv was expressed at a high level as inclusion bodies in Escherichia coli. We refolded the scFv (Ka=2.35×10−7 M by ion-exchange chromatography, dialysis, and dilution. The results showed that column chromatography refolding by high-performance Q Sepharose had remarkable advantages over conventional dilution and dialysis methods. Furthermore, the anti-ICAM-1 scFv yield of about 60 mg/L was higher with this method. The purity of the final product was greater than 90%, as shown by denaturing gel electrophoresis. Enzyme-linked immunosorbent assay, cell culture, and animal experiments were used to assess the immunological properties and biological activities of the renatured scFv.

  8. Triple immunoglobulin gene knockout transchromosomic cattle: bovine lambda cluster deletion and its effect on fully human polyclonal antibody production.

    Directory of Open Access Journals (Sweden)

    Hiroaki Matsushita

    Full Text Available Towards the goal of producing fully human polyclonal antibodies (hpAbs or hIgGs in transchromosomic (Tc cattle, we previously reported that Tc cattle carrying a human artificial chromosome (HAC comprising the entire unrearranged human immunoglobulin (Ig heavy-chain (hIGH, kappa-chain (hIGK, and lambda-chain (hIGL germline loci produced physiological levels of hIgGs when both of the bovine immunoglobulin mu heavy-chains, bIGHM and bIGHML1, were homozygously inactivated (bIGHM-/-, bIGHML1-/-; double knockouts or DKO. However, because endogenous bovine immunoglobulin light chain loci are still intact, the light chains are produced both from the hIGK and hIGL genomic loci on the HAC and from the endogenous bovine kappa-chain (bIGK and lambda-chain (bIGL genomic loci, resulting in the production of fully hIgGs (both Ig heavy-chains and light-chains are of human origin: hIgG/hIgκ or hIgG/hIgλ and chimeric hIgGs (Ig heavy-chains are of human origin while the Ig light-chains are of bovine origin: hIgG/bIgκ or hIgG/bIgλ. To improve fully hIgG production in Tc cattle, we here report the deletion of the entire bIGL joining (J and constant (C gene cluster (bIGLJ1-IGLC1 to bIGLJ5-IGLC5 by employing Cre/loxP mediated site-specific chromosome recombination and the production of triple knockout (bIGHM-/-, bIGHML1-/- and bIGL-/-; TKO Tc cattle. We further demonstrate that bIGL cluster deletion greatly improves fully hIgGs production in the sera of TKO Tc cattle, with 51.3% fully hIgGs (hIgG/hIgκ plus hIgG/hIgλ.

  9. Large Scale Production and Characterization of Anti-Human IgG Monoclonal Antibody in Peritoneum of Balb/c MICE

    Directory of Open Access Journals (Sweden)

    B. Baradaran

    2005-01-01

    Full Text Available Monoclonal antibodies are key reagents that are used in biomedical researches, diagnosis of immunodeficiency diseases such as IgG subclasses deficiency and treatment of diseases like infections and cancers .For large scale production of monoclonal antibody, hybridoma cells that produce monoclonal antibody against human IgG were injected into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. After ten days, approximately 3 ml ascitic fluid was harvested from the peritoneum of each mouse. Ascitic fluid was assayed for the titer of monoclonal antibody in reaction with human IgG and its cross reactivity in reaction with IgM & IgA. The titer of mAb was 100,000 and didn't show cross reactivity with IgM & IgA. Immunobloting was done for confirming the ELISA method. In immunobloting, only one sharp band in the heavy chain position of IgG was developed. The subclass of antibody was IgG1 and its light chain was kappa. Ascitic fluid was purified by ion exchange chromatography and the purified monoclonal antibody was conjugated with HRP. The conjugated monoclonal antibody could have application in diagnosis of infectious diseases like Toxoplasmosis, Rubella and IgG class of all other infectious diseases.

  10. Lipoxin A4 decreases human memory B cell antibody production via an ALX/FPR2-dependent mechanism: A link between resolution signals and adaptive immunity

    Science.gov (United States)

    Ramon, Sesquile; Bancos, Simona; Serhan, Charles N.; Phipps, Richard P.

    2013-01-01

    Summary Specialized proresolving mediators (SPMs) are endogenous bioactive lipid molecules that play a fundamental role in the regulation of inflammation and its resolution. SPMs are classified into lipoxins, resolvins, protectins and maresins. Lipoxins and other SPMs have been identified in important immunological tissues including bone marrow, spleen and blood. Lipoxins regulate functions of the innate immune system including the promotion of monocyte recruitment and increase macrophage phagocytosis of apoptotic neutrophils. A major knowledge gap is whether lipoxins influence adaptive immune cells. Here, we analyzed the actions of lipoxin A4 (LXA4) and its receptor ALX/FPR2 on human B cells. LXA4 decreased IgM and IgG production on activated B cells through ALX/FPR2-dependent signaling, which downregulated NF-κB p65 nuclear translocation. LXA4 also inhibited human memory B cell antibody production and proliferation, but not naïve B cell function. Lastly, LXA4 decreased antigen-specific antibody production in vivo. To our knowledge, this is the first description of the actions of lipoxins on human B cells, which shows a link between resolution signals and adaptive immunity. Regulating antibody production is crucial to prevent unwanted inflammation. Harnessing the ability of lipoxins to decrease memory B cell antibody production can be beneficial to threat inflammatory and autoimmune disorders. PMID:24166736

  11. Production and characterization of murine monoclonal anti-human DNase II antibodies, and their use for immunoaffinity purification of DNase II from human liver and urine.

    Science.gov (United States)

    Nakajima, Tamiko; Yasuda, Toshihiro; Takeshita, Haruo; Mori, Shinjiro; Mogi, Kouichi; Kaneko, Yasushi; Nakazato, Emiko; Kishi, Koichiro

    2002-04-15

    Four murine monoclonal anti-human deoxyribonuclease II (DNase II) antibodies were obtained from BALB/c mice immunized with human DNase II purified from human liver. Both single radial enzyme diffusion (SRED) and DNA-cast polyacrylamide gel electrophoresis (DNA-cast PAGE) were very useful for obtaining the DNase II-specific antibodies. All of the antibodies showed specific inhibition of human DNase II enzyme activity and specific immunostaining of the 32-kDa enzyme band, which is one of the three non-identical subunits of human DNase II molecule separated by sodium dodecyl sulfate (SDS)-PAGE followed by blotting on a transfer membrane. A formyl-cellulofine resin conjugated with each antibody specifically adsorbed and efficiently desorbed the active DNase II enzyme. Insertion of the immunoaffinity step in our purification procedure made the purification of human DNase II easier, faster and more effective than the conventional procedure.

  12. Triple Immunoglobulin Gene Knockout Transchromosomic Cattle: Bovine Lambda Cluster Deletion and Its Effect on Fully Human Polyclonal Antibody Production

    OpenAIRE

    Hiroaki Matsushita; Akiko Sano; Hua Wu; Jin-An Jiao; Poothappillai Kasinathan; Eddie J. Sullivan; Zhongde Wang; Yoshimi Kuroiwa

    2014-01-01

    Towards the goal of producing fully human polyclonal antibodies (hpAbs or hIgGs) in transchromosomic (Tc) cattle, we previously reported that Tc cattle carrying a human artificial chromosome (HAC) comprising the entire unrearranged human immunoglobulin (Ig) heavy-chain (hIGH), kappa-chain (hIGK), and lambda-chain (hIGL) germline loci produced physiological levels of hIgGs when both of the bovine immunoglobulin mu heavy-chains, bIGHM and bIGHML1, were homozygously inactivated (bIGHM−/− , bIGHM...

  13. Triple Immunoglobulin Gene Knockout Transchromosomic (Tc) Cattle: Bovine Lambda Cluster Deletion and its Effect on Fully Human Polyclonal Antibody Production

    OpenAIRE

    Matsushita, H.; Sano, A.; Wu, H.; J. Jiao; Kasinathan, P.; Sullivan, E. J.; Wang, Zhongde; Kuroiwa, K

    2014-01-01

    Towards the goal of producing fully human polyclonal antibodies (hpAbs or hIgGs) in transchromosomic (Tc) cattle, we previously reported that Tc cattle carrying a human artificial chromosome (HAC) comprising the entire unrearranged human immunoglobulin (Ig) heavy-chain (hIGH), kappa-chain (hIGK), and lambda-chain (hIGL) germline loci produced physiological levels of hIgGs when both of the bovine immunoglobulin mu heavy-chains, bIGHM and bIGHML1, were homozygously inactivated (bIGHM-/-, bIGHML...

  14. Ibuprofen and other widely used non-steroidal anti-inflammatory drugs inhibit antibody production in human cells.

    Science.gov (United States)

    Bancos, Simona; Bernard, Matthew P; Topham, David J; Phipps, Richard P

    2009-01-01

    The widely used non-steroidal anti-inflammatory drugs (NSAIDs) function mainly through inhibition of cyclooxygenases 1 and 2 (Cox-1 and Cox-2). Unlike Cox-1, Cox-2 is considered an inducible and pro-inflammatory enzyme. We previously reported that Cox-2 is upregulated in activated human B lymphocytes and using Cox-2 selective inhibitors that Cox-2 is required for optimal antibody synthesis. It is not known whether commonly used non-prescription and non-Cox-2 selective drugs also influence antibody synthesis. Herein, we tested a variety of Cox-1/Cox-2 non-selective NSAIDs, namely ibuprofen, tylenol, aspirin and naproxen and report that they blunt IgM and IgG synthesis in stimulated human peripheral blood mononuclear cells (PBMC). Ibuprofen had its most profound effects in inhibiting human PBMCs and purified B lymphocyte IgM and IgG synthesis when administered in the first few days after activation. As shown by viability assays, ibuprofen did not kill B cells. The implications of this research are that the use of widely available NSAIDs after infection or vaccination may lower host defense. This may be especially true for the elderly who respond poorly to vaccines and heavily use NSAIDs.

  15. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    Zegers, N.D.

    1995-01-01

    Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the uni

  16. Production and Screening of Monoclonal Peptide Antibodies.

    Science.gov (United States)

    Trier, Nicole Hartwig; Mortensen, Anne; Schiolborg, Annette; Friis, Tina

    2015-01-01

    Hybridoma technology is a remarkable and indispensable tool for generating high-quality monoclonal antibodies. Hybridoma-derived monoclonal antibodies not only serve as powerful research and diagnostic reagents, but have also emerged as the most rapidly expanding class of therapeutic biologicals. In this chapter, an overview of hybridoma technology and the laboratory procedures used routinely for hybridoma production and antibody screening are presented, including characterization of peptide antibodies.

  17. 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.

  18. RNA sensors enable human mast cell anti-viral chemokine production and IFN-mediated protection in response to antibody-enhanced dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Michael G Brown

    Full Text Available Dengue hemorrhagic fever and/or dengue shock syndrome represent the most serious pathophysiological manifestations of human dengue virus infection. Despite intensive research, the mechanisms and important cellular players that contribute to dengue disease are unclear. Mast cells are tissue-resident innate immune cells that play a sentinel cell role in host protection against infectious agents via pathogen-recognition receptors by producing potent mediators that modulate inflammation, cell recruitment and normal vascular homeostasis. Most importantly, mast cells are susceptible to antibody-enhanced dengue virus infection and respond with selective cytokine and chemokine responses. In order to obtain a global view of dengue virus-induced gene regulation in mast cells, primary human cord blood-derived mast cells (CBMCs and the KU812 and HMC-1 mast cell lines were infected with dengue virus in the presence of dengue-immune sera and their responses were evaluated at the mRNA and protein levels. Mast cells responded to antibody-enhanced dengue virus infection or polyinosiniċpolycytidylic acid treatment with the production of type I interferons and the rapid and potent production of chemokines including CCL4, CCL5 and CXCL10. Multiple interferon-stimulated genes were also upregulated as well as mRNA and protein for the RNA sensors PKR, RIG-I and MDA5. Dengue virus-induced chemokine production by KU812 cells was significantly modulated by siRNA knockdown of RIG-I and PKR, in a negative and positive manner, respectively. Pretreatment of fresh KU812 cells with supernatants from dengue virus-infected mast cells provided protection from subsequent infection with dengue virus in a type I interferon-dependent manner. These findings support a role for tissue-resident mast cells in the early detection of antibody-enhanced dengue virus infection via RNA sensors, the protection of neighbouring cells through interferon production and the potential recruitment of

  19. A role for uric acid and the Nalp3 inflammasome in antiphospholipid antibody-induced IL-1β production by human first trimester trophoblast.

    Directory of Open Access Journals (Sweden)

    Melissa J Mulla

    Full Text Available Women with antiphospholipid syndrome (APS are at risk of recurrent pregnancy loss and obstetrical disorders, such as preeclampsia and intrauterine growth restriction (IUGR. Antiphospholipid antibodies (aPL directly target the placenta by binding beta2-glycoprotein I (β2GPI expressed on the trophoblast. We recently demonstrated in human first trimester trophoblast cells that anti-β2GPI antibodies (Abs induce the secretion of IL-1β in a Toll-like receptor 4 (TLR4-dependent manner. IL-1β secretion requires processing of pro-IL-1β and this is mediated by the inflammasome, a complex of Nalp3, apoptosis-associated speck-like protein containing a CARD (ASC and caspase-1. The objective of this study was to determine if aPL induce IL-1β production in trophoblast via the inflammasome. Using a human first trimester trophoblast cell line, we demonstrated that a mouse anti-β2GPI mAb and human polyclonal aPL-IgG induce IL-1β processing and secretion, which was partially blocked upon caspase-1 inhibition. Nalp3 and ASC knockdown also attenuated anti-β2GPI Ab-induced IL-1β secretion. Furthermore, aPL stimulated the production of uric acid in a TLR4-dependent manner; and inhibition of uric acid prevented aPL-induced IL-1β production by the trophoblast. These findings demonstrate that aPL, via TLR4 activation, induce a uric acid response in human trophoblast, which in turn activates the Nalp3/ASC inflammasome leading to IL-1β processing and secretion. This novel mechanism may account for the inflammation at the maternal-fetal interface, which causes placental dysfunction and increases the risk of adverse pregnancy outcome in patients with APS.

  20. Prokaryotic expression, purification, and production of polyclonal antibody against novel human serum inhibited related protein I (SI1).

    Science.gov (United States)

    Ma, Mingxing; Ma, Jie; Shi, Yinghui; Wu, Hong; Zhao, Wenxiu; Huang, Weiwei; Jiao, Yang; Tan, Deyong

    2010-02-01

    A novel serum inhibited related gene (SI1) has been cloned in our lab by using mRNA differential display analysis of U251 cells in the presence or absence of serum, the expression of SI1 was dramatically inhibited by the addition of serum to serum starved cells. Previous reports suggested the potential significance of SI1 in regulating the cell cycle. In this study, the plasmid construction, protein expression and purification, as well as the generation of anti-SI1 polyclonal antibody are described. A full-length cDNA of Si1 was inserted in a prokaryotic expression plasmid pET28-b(+) and efficiently expressed in E. coli Rosetta (DE3) strain after induction by isopropyl-b-D: -thiogalactoside. The expressed 6His-tagged SI1 fusion protein was purified by Ni(+) affinity column and then used to immunize Balb/C mice, and the anti-SI1 polyclonal antibody was purified by protein A column. To determine the sensitivity and specificity of the antibody against SI1, a cell lysate of pEGFP-N2-SI1 plasmid transiently transfected Hela cell was identified by anti-GFP monoclonal antibody and anti-SI1 polyclonal antibody. Both the GFP-SI1 fusion protein and endogenous SI1 protein in Hela cell can be recognized by the anti-SI1 polyclonal antibody. The anti-SI1 polyclonal antibody will provide a useful tool for further characterization of SI1.

  1. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  2. Enhanced Phagocytosis and Antibody Production by Tinospora ...

    African Journals Online (AJOL)

    SERVER

    2008-01-18

    Jan 18, 2008 ... antibody production through in vitro and in vivo studies. MATERIALS AND METHODS. Collection of plant .... and were fed orally to each animal for 14 days. After 14 days of .... Rubiadin: A new antioxidant from Rubia cardifolia.

  3. Rescue and expression of human immunoglobulin genes to generate functional human monoclonal antibodies.

    Science.gov (United States)

    Lewis, A P; Parry, N; Peakman, T C; Crowe, J S

    1992-07-01

    Human monoclonal antibody production has been hampered for many years by the instability of cell lines and low levels of expression of the antibodies. We describe here the rescue of human immunoglobulin genes utilizing micro-mRNA preparation from a small number of human hybridoma cells and conventional cDNA cloning. This allows cloning and immediate high-level expression from full-length human heavy and light chain cDNA molecules and provides a mechanism to rescue whole human monoclonal antibodies of proven efficacy.

  4. Antisperm antibodies and human reproduction.

    Science.gov (United States)

    Check, J H

    2010-01-01

    To present strategies in diagnosing and treating infertility related to antisperm antibodies. Antisperm antibodies (ASA) were detected on sperm using the direct immunobead (IBD) test. Treatments included intrauterine insemination (IUI) with pretreatment with chymotrypsin/galactose vs. in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). Intrauterine insemination with protein digestive enzyme treatment was much more effective than IUI without enzymatic therapy. However IVF with ICSI provided three times the pregnancy rate for males with sperm coated with ASA than IUI with chymotrypsin treated sperm. It is advisable to include measurement for ASA on the initial semen analysis. However, another option is to perform it initially only with an abnormal post-coital test. The decision for IUI with chymotrypsin pretreatment of the sperm vs. IVF with ICSI may depend on insurance and financial issues.

  5. Enhancement of antibody production to hepatitis B surface antigen by anti-idiotypic antibody.

    OpenAIRE

    Kakumu, S; Murase, K.; A Tsubouchi; Yoshioka, K.; Sakamoto, N.

    1986-01-01

    Studies were undertaken to determine whether anti-idiotypic antibody (anti-Id) against antibody to hepatitis B surface antigen (anti-HBs) could modulate in vitro anti-HBs production by human peripheral blood mononuclear cells stimulated with pokeweed mitogen. Peripheral blood mononuclear cells from patients positive for serum anti-HBs produced significantly increased amounts of anti-HBs by the addition of IgG fraction of anti-anti-HBs as well as purified HBsAg in a soluble form when compared ...

  6. New monoclonal antibodies directed against human renin. Powerful tools for the investigation of the renin system.

    OpenAIRE

    Galen, F X; Devaux, C.; Atlas, S; Guyenne, T; Menard, J; Corvol, P; Simon, D.; Cazaubon, C; Richer, P; Badouaille, G

    1984-01-01

    Monoclonal antibodies directed against human renin were obtained by the fusing of myeloma cells with spleen cells from Balb/c or high-responder Biozzi mice injected with pure tumoral or highly purified renal renin. These procedures resulted in the production of seven stable monoclonal antibodies to human renin. Antibodies in the hybridoma culture medium were screened by binding to pure iodinated renin or insolubilized renin in a solid phase assay. The concentration of purified antibodies that...

  7. Tetanus Neurotoxin Neutralizing Antibodies Screened from a Human Immune scFv Antibody Phage Display Library.

    Science.gov (United States)

    Wang, Han; Yu, Rui; Fang, Ting; Yu, Ting; Chi, Xiangyang; Zhang, Xiaopeng; Liu, Shuling; Fu, Ling; Yu, Changming; Chen, Wei

    2016-09-11

    Tetanus neurotoxin (TeNT) produced by Clostridium tetani is one of the most poisonous protein substances. Neutralizing antibodies against TeNT can effectively prevent and cure toxicosis. Using purified Hc fragments of TeNT (TeNT-Hc) as an antigen, three specific neutralizing antibody clones recognizing different epitopes were selected from a human immune scFv antibody phage display library. The three antibodies (2-7G, 2-2D, and S-4-7H) can effectively inhibit the binding between TeNT-Hc and differentiated PC-12 cells in vitro. Moreover, 2-7G inhibited TeNT-Hc binding to the receptor via carbohydrate-binding sites of the W pocket while 2-2D and S-4-7H inhibited binding of the R pocket. Although no single mAb completely protected mice from the toxin, they could both prolong survival when challenged with 20 LD50s (50% of the lethal dose) of TeNT. When used together, the mAbs completely neutralized 1000 LD50s/mg Ab, indicating their high neutralizing potency in vivo. Antibodies recognizing different carbohydrate-binding pockets could have higher synergistic toxin neutralization activities than those that recognize the same pockets. These results could lead to further production of neutralizing antibody drugs against TeNT and indicate that using TeNT-Hc as an antigen for screening human antibodies for TeNT intoxication therapy from human immune antibody library was convenient and effective.

  8. Tetanus Neurotoxin Neutralizing Antibodies Screened from a Human Immune scFv Antibody Phage Display Library

    Science.gov (United States)

    Wang, Han; Yu, Rui; Fang, Ting; Yu, Ting; Chi, Xiangyang; Zhang, Xiaopeng; Liu, Shuling; Fu, Ling; Yu, Changming; Chen, Wei

    2016-01-01

    Tetanus neurotoxin (TeNT) produced by Clostridium tetani is one of the most poisonous protein substances. Neutralizing antibodies against TeNT can effectively prevent and cure toxicosis. Using purified Hc fragments of TeNT (TeNT-Hc) as an antigen, three specific neutralizing antibody clones recognizing different epitopes were selected from a human immune scFv antibody phage display library. The three antibodies (2-7G, 2-2D, and S-4-7H) can effectively inhibit the binding between TeNT-Hc and differentiated PC-12 cells in vitro. Moreover, 2-7G inhibited TeNT-Hc binding to the receptor via carbohydrate-binding sites of the W pocket while 2-2D and S-4-7H inhibited binding of the R pocket. Although no single mAb completely protected mice from the toxin, they could both prolong survival when challenged with 20 LD50s (50% of the lethal dose) of TeNT. When used together, the mAbs completely neutralized 1000 LD50s/mg Ab, indicating their high neutralizing potency in vivo. Antibodies recognizing different carbohydrate-binding pockets could have higher synergistic toxin neutralization activities than those that recognize the same pockets. These results could lead to further production of neutralizing antibody drugs against TeNT and indicate that using TeNT-Hc as an antigen for screening human antibodies for TeNT intoxication therapy from human immune antibody library was convenient and effective. PMID:27626445

  9. Tetanus Neurotoxin Neutralizing Antibodies Screened from a Human Immune scFv Antibody Phage Display Library

    Directory of Open Access Journals (Sweden)

    Han Wang

    2016-09-01

    Full Text Available Tetanus neurotoxin (TeNT produced by Clostridium tetani is one of the most poisonous protein substances. Neutralizing antibodies against TeNT can effectively prevent and cure toxicosis. Using purified Hc fragments of TeNT (TeNT-Hc as an antigen, three specific neutralizing antibody clones recognizing different epitopes were selected from a human immune scFv antibody phage display library. The three antibodies (2-7G, 2-2D, and S-4-7H can effectively inhibit the binding between TeNT-Hc and differentiated PC-12 cells in vitro. Moreover, 2-7G inhibited TeNT-Hc binding to the receptor via carbohydrate-binding sites of the W pocket while 2-2D and S-4-7H inhibited binding of the R pocket. Although no single mAb completely protected mice from the toxin, they could both prolong survival when challenged with 20 LD50s (50% of the lethal dose of TeNT. When used together, the mAbs completely neutralized 1000 LD50s/mg Ab, indicating their high neutralizing potency in vivo. Antibodies recognizing different carbohydrate-binding pockets could have higher synergistic toxin neutralization activities than those that recognize the same pockets. These results could lead to further production of neutralizing antibody drugs against TeNT and indicate that using TeNT-Hc as an antigen for screening human antibodies for TeNT intoxication therapy from human immune antibody library was convenient and effective.

  10. Recombinant anti-human melanoma antibodies are versatile molecules.

    Science.gov (United States)

    Neri, D; Natali, P G; Petrul, H; Soldani, P; Nicotra, M R; Vola, R; Rivella, A; Creighton, A M; Neri, P; Mariani, M

    1996-08-01

    The low cost, high versatility, and reliable production of bacterially produced recombinant antibody fragments speeds up the development of tumor-targeting agents. High-quality recombinant anti-melanoma antibodies are much sought after in the scientific community. We cloned the murine antibody 225.28S, currently used in radioimmunoimaging of human melanoma lesions, in single-chain Fv configuration (scFv) for soluble expression in bacteria. The recombinant antibody fragment conserved the binding specificity of the parental antibody. In order to arm the scFv(225.28S) with biologically useful effector functions, we developed vectors for soluble expression of scFv(225.28S) in bacteria that allow both covalent and noncovalent chemical antibody modification at positions that do not interfere with antigen binding. An expression vector was developed that appends a cysteine residue at the C-terminal extremity of the recombinant antibody, thus allowing reaction with thiol-specific reagents, including 99mTc labeling, at a position that does not interfere with antigen binding. The scFv(225.28S) was also successfully expressed with a casein kinase II substrate tag that enables efficient and stable 32P labeling. For noncovalent antibody modification, we developed an expression vector that appends the human calmodulin gene at the C-terminal extremity of scFv(225.28S). The calmodulin domain is poorly immunogenic and can be targeted with chemically modified high-affinity calmodulin ligands. The recombinant anti-human melanoma antibodies described in this article should prove useful "building blocks" for the development of anti-melanoma diagnostic and therapeutic strategies.

  11. Production and assay of forskolin antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ho, L.T.; Ho, R.J.

    1986-05-01

    Forskolin (Fo), a cardiovascular active diterpene of plant origin, has been widely used as a research tool in regulation of the catalytic activity of adenylate cyclase (AC). A linear relationship of Fo binding to plasma membrane with activation of AC has been reported. The present abstract describes the production and assay of Fo antibodies (AB). 7-0-Hemisuccinyl-7-deacetyl Fo, coupled to either human serum albumin or goat IgG, was injected into goats to elicit AB to Fo haptan. AB to Fo in antiserum or an isolated IgG fraction was tested by two assay methods, a radioimmunoassay using /sup 3/H-Fo as a tracer and a colorimetric enzyme-linked immunosorbent assay (ELISA) using horse radish peroxidase-rabbit anti goat IgG as indicator. The titers for Fo antiserum were 4000-10,000. In the defined assay condition, approximately 20-25% of the added /sup 3/H-Fo was found to bind to AB. The bound radioactivity was displaced by Fo-HSA or Fo-goat IgG or free unlabelled Fo ranging from 0.5-50 pmol/tube, or 5-500 nM. The IC/sub 50/ was approximately 8-10 pmol/tube or 80-100 nM. The binding of HRP-rabbit anti goat IgG in the ELISA was inhibited by proper Fo conjugate. The development of methods for production and assay for Fo AB may be useful in the study of mechanism of activation of AC by Fo and Fo-like compound.

  12. A human-mouse hybridoma producing monoclonal antibody against human sperm coating antigen.

    Science.gov (United States)

    Kyurkchiev, S D; Shigeta, M; Koyama, K; Isojima, S

    1986-01-01

    Since anti-sperm antibodies were first discovered in the sera of women, the relationship of these antibodies to sterility has been studied by many investigators. In order to determine the antigens of spermatozoa responsible for raising antibodies to spermatozoa in humans, many studies have been carried out by purifying human spermatozoa cell membrane and seminal plasma components. Since it was found that the purification was difficult by physiochemical procedures, the immunoaffinity chromatography bound monoclonal antibody (Mab) to spermatozoa antigens was attempted for this purpose. The establishment of hybridomas producing Mabs to human seminal plasma and human spermatozoa was reported by Shigeta et al. (1980), Isojima, Koyoma & Fujiwara (1982), Lee et al. (1982) and Isahakia & Alexander (1984). The ordinary approaches to obtain the Mabs consisted of xenogenic immunization with human semen and cell fusion of immunized spleen cells with mouse myeloma cells. However, the antigenic epitopes of human spermatozoa, which induced antibody production, are xenogenic for the mouse, and therefore there is a possibility that there is a difference in recognized antigenic epitopes in humans as isotypic and in mice as xenogenic. In order to study these antigenic epitopes, which correspond to antibodies against spermatozoa in women, the establishment of human-mouse hybridomas, which produced anti-semen antibodies as produced in sterile women, became essential. In these studies, we used recently developed cell fusion techniques to fuse immunized human peripheral lymphocytes with mouse myeloma cells. PMID:3456978

  13. Human antibody and antigen response to IncA antibody of Chlamydia trachomatis.

    Science.gov (United States)

    Tsai, P Y; Hsu, M C; Huang, C T; Li, S Y

    2007-01-01

    The high prevalence of C. trachomatis worldwide has underscored the importance of identifying specific immunogenic antigens in facilitating diagnosis as well as vaccine development. The aim of this study is to evaluate IncA antibody and antigen production in natural human infections. Our temporal expression study showed that IncA transcription and protein expression could be detected as early as 4 hours after the start of infection. Antibody responses could be detected in urine and genital swab samples from C. trachomatis-positive patients. It is especially interesting to note that the IncA antigen could be detected in urine. In conclusion, we have identified IncA as an important antigen in human. The potential applicability of the IncA antibody or antigen in the diagnosis as well as to vaccine development for C. trachomatis is also discussed.

  14. Production and radioimmunoimaging of novel fully human phage display recombinant antibodies and growth inhibition of lung adenocarcinoma cell line overexpressing Prx I.

    Science.gov (United States)

    Luo, Yi; Pang, Hua; Li, Shujie; Cao, Hui; Peng, Zhiping; Fan, Chunbo; Li, Shaolin

    2009-07-01

    The Peroxiredoxin I (Prx I) is a member of the Peroxiredoxin family, which is overexpressed in many diverse tumor types and is an anti-apoptosis protein for tumor cell proliferation and survival. Therapeutic strategies targeting the Prx I may therefore be effective broad-spectrum anticancer agents. We constructed a phage display single-chain variable fragment (scFv) antibody library and sieve out the fully human, lung adenocarcinoma-sepcific monoclonal antibodies. The selection on Prx I was performed using above-mentioned lung adenocarcinoma-sepcific monoclonal antibodies with high affinity to Prx I overexpressing lung adenocarcinoma cells. The candidate scFv sequences, based on enzyme-linked immunosorbent assay (ELISA) screening data, were chosen for soluble expression, and a 30 kDa band was observed on polyacrylamide gel electrophoresis as predicted. The purified antibodies were characterized by immunoblotting and showed high specificity to Prx I-overexpressing lung adenocarcinoma cells A549. Radioimmunoimaging was taken to evaluate specificity and distribution of antibodies in vivo. The radiolocalization index (RI) of tumor/serum and tumor/muscle gradually increased, reaching its peak (4.06 +/- 0.13 and 5.17 +/- 0.97, respectively) at 48 h postadministration. Single photon emission computed tomography (SPECT) imaging showed the radioactivity was aggregated in tumor locations and tumor imaging was clearly observed. The internalized scFv resulted in antibody-mediated cell apoptosis and downregulation of Prx I expression. These results demonstrate that the scFv possesses strong antitumor activity on lung adenocarcinoma and may therefore be an effective therapeutic candidate for the treatment of cancers that are dependent on Prx I for growth and survival.

  15. Influence of Exogenous Reproductive Hormones on Specific Antibody Production in Genital Secretions after Vaginal Vaccination with Recombinant Cholera Toxin B Subunit in Humans

    OpenAIRE

    Wassen, Lotta; Jertborn, Marianne

    2006-01-01

    The objective of this study was to investigate the influence of exogenous reproductive hormones on the local and systemic production of specific immunoglobulin A (IgA) and IgG antibodies after vaginal vaccination with recombinant cholera toxin subunit B (CTB). Three groups of women using either progesterone-containing intrauterine devices (n = 9), oral contraceptives (n = 8), or no hormonal contraceptive methods (n = 9) were vaginally immunized twice, 2 weeks apart. Cervical secretions, vagin...

  16. The production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi

    NARCIS (Netherlands)

    Joosten, V.; Lokman, C.; Hondel, C.A.M.J.J. van den; Punt, P.J.

    2003-01-01

    In this review we will focus on the current status and views concerning the production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi. We will focus on single-chain antibody fragment production (scFv and VHH) by these lower eukaryotes and the possible applications

  17. The production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi

    NARCIS (Netherlands)

    Joosten, V.; Lokman, C.; Hondel, C.A.M.J.J. van den; Punt, P.J.

    2003-01-01

    In this review we will focus on the current status and views concerning the production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi. We will focus on single-chain antibody fragment production (scFv and VHH) by these lower eukaryotes and the possible applications

  18. Human germline antibody gene segments encode polyspecific antibodies.

    Science.gov (United States)

    Willis, Jordan R; Briney, Bryan S; DeLuca, Samuel L; Crowe, James E; Meiler, Jens

    2013-04-01

    Structural flexibility in germline gene-encoded antibodies allows promiscuous binding to diverse antigens. The binding affinity and specificity for a particular epitope typically increase as antibody genes acquire somatic mutations in antigen-stimulated B cells. In this work, we investigated whether germline gene-encoded antibodies are optimal for polyspecificity by determining the basis for recognition of diverse antigens by antibodies encoded by three VH gene segments. Panels of somatically mutated antibodies encoded by a common VH gene, but each binding to a different antigen, were computationally redesigned to predict antibodies that could engage multiple antigens at once. The Rosetta multi-state design process predicted antibody sequences for the entire heavy chain variable region, including framework, CDR1, and CDR2 mutations. The predicted sequences matched the germline gene sequences to a remarkable degree, revealing by computational design the residues that are predicted to enable polyspecificity, i.e., binding of many unrelated antigens with a common sequence. The process thereby reverses antibody maturation in silico. In contrast, when designing antibodies to bind a single antigen, a sequence similar to that of the mature antibody sequence was returned, mimicking natural antibody maturation in silico. We demonstrated that the Rosetta computational design algorithm captures important aspects of antibody/antigen recognition. While the hypervariable region CDR3 often mediates much of the specificity of mature antibodies, we identified key positions in the VH gene encoding CDR1, CDR2, and the immunoglobulin framework that are critical contributors for polyspecificity in germline antibodies. Computational design of antibodies capable of binding multiple antigens may allow the rational design of antibodies that retain polyspecificity for diverse epitope binding.

  19. Current status of cancer immunodetection with radiolabeled human monoclonal antibodies.

    Science.gov (United States)

    De Jager, R; Abdel-Nabi, H; Serafini, A; Pecking, A; Klein, J L; Hanna, M G

    1993-04-01

    The use of radiolabeled murine monoclonal antibodies (MoAbs) for cancer immunodetection has been limited by the development of human antimouse antibodies (HAMA). Human monoclonal antibodies do not elicit a significant human antihuman (HAHA) response. The generation and production of human monoclonal antibodies met with technical difficulties that resulted in delaying their clinical testing. Human monoclonal antibodies of all isotypes have been obtained. Most were immunoglobulin (Ig) M directed against intracellular antigens. Two antibodies, 16.88 (IgM) and 88BV59 (IgG3k), recognize different epitopes on a tumor-associated antigen, CTA 16.88, homologous to cytokeratins 8, 18, and 19. CTA 16.88 is expressed by most epithelial-derived tumors including carcinomas of the colon, pancreas, breast, ovary, and lung. The in vivo targeting by these antibodies is related to their localization in nonnecrotic areas of tumors. Repeated administration of 16.88 over 5 weeks to a cumulative dose of 1,000 mg did not elicit a HAHA response. Two of 53 patients developed a low titer of HAHA 1 to 3 months after a single administration of 88BV59. Planar imaging of colorectal cancer with Iodine-131 (131I)-16.88 was positive in two studies in 9 of 12 and 16 of 20 patients preselected by immunohistochemistry. Tumors less than 2 cm in diameter are usually not detected. The lack of immunogenicity and long tumor residence time (average = 17 days) makes 16.88 a good candidate for therapy. Radioimmunlymphoscintigraphy with indium-111 (111In)-LiLo-16.88 administered by an intramammary route was used in the presurgical staging of primary breast cancer. The negative predictive value of lymph node metastases for tumors less than 3 cm was 90.5%. Planar and single photon emission computed tomography imaging of colorectal carcinoma with technetium-99m (99mTc) 88BV59 was compared with computed tomography (CT) scan in 36 surgical patients. The antibody scan was more sensitive than the CT scan in detecting

  20. Immunogenicity assessment of monoclonal antibody products: A simulated case study correlating antibody induction with clinical outcomes.

    Science.gov (United States)

    Knezevic, Ivana; Kang, Hye-Na; Thorpe, Robin

    2015-09-01

    Monoclonal antibodies are large molecules with complex structure and functions. They have a wide application for treatment of a broad range of chronic diseases and represent the largest class of biotherapeutic products. Given that biotherapeutic products may induce unwanted humoral and/or cellular immune responses in recipients, it is essential to investigate the immunogenicity of a product prior to licensure. The immune response is influenced by many factors and data generated in the pre-licensure studies are usually somewhat difficult for regulatory review. The knowledge and expertise required for this requires a thorough understanding of animal and human immunology as well as specific product characteristics, including mechanism of action, antibody assays and assessment of results in a given clinical context. The appropriate interpretation of immunogenicity data is of critical importance for defining the safety profile of a monoclonal antibody. Two case studies described in this paper were prepared to mimic a real situation in which regulators need to evaluate immunogenicity studies conducted by manufacturers of monoclonal antibody products. The specific objective of the case studies was to illustrate assessment of unwanted immunogenicity and the important factors that need to be considered in this context. Regulators and manufacturers who attended the World Health Organization (WHO) implementation workshop on Evaluation of Biotherapeutic Products, held in Seoul, Republic of Korea, in May 2014, participated in the case studies and provided valuable input. This article outlines the main aspects of immunogenicity discussed in these case studies and a summary of the lessons learned at this occasion. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  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. Secondary Mechanisms of Affinity Maturation in the Human Antibody Repertoire

    Directory of Open Access Journals (Sweden)

    Bryan S. Briney

    2013-03-01

    Full Text Available V(DJ recombination and somatic hypermutation (SHM are the primary mechanisms for diversification of the human antibody repertoire. These mechanisms allow for rapid humoral immune responses to a wide range of pathogenic challenges. V(DJ recombination efficiently generate a virtually limitless diversity through random recombination of variable (V, diversity (D and joining (J genes with diverse nontemplated junctions between the selected gene segments. Following antigen stimulation, affinity maturation by SHM produces antibodies with refined specificity mediated by mutations typically focused in complementarity determining regions (CDRs, which form the bulk of the antigen recognition site. While V(DJ recombination and SHM are responsible for much of the diversity of the antibody repertoire, there are several secondary mechanisms that, while less frequent, make substantial contributions to antibody diversity including V(DDJ recombination (or D-D fusion, somatic-hypermutation-associated insertions and deletions, and affinity maturation and antigen contact by non-CDR regions of the antibody. In addition to enhanced diversity, these mechanisms allow the production of antibodies that are critical to response to a variety of viral and bacterial pathogens but that would be difficult to generate using only the primary mechanisms of diversification.

  3. DARPA Antibody Technology Program Standardized Test Bed for Antibody Characterization: Characterization of an MS2 Human IgG Antibody Produced by AnaptysBio, Inc.

    Science.gov (United States)

    2016-02-01

    ECBC-TR-1339 DARPA ANTIBODY TECHNOLOGY PROGRAM STANDARDIZED TEST BED FOR ANTIBODY...CHARACTERIZATION: CHARACTERIZATION OF AN MS2 HUMAN IGG ANTIBODY PRODUCED BY ANAPTYSBIO, INC. DARPA ATP Standardized Test Bed for Antibody...Characterization: Characterization of an MS2 human IgG antibody produced by AnaptysBio DARPA ATP Standardized Test Bed for Antibody

  4. Belimumab: anti-BLyS human monoclonal antibody, anti-BLyS monoclonal antibody, BmAb, human monoclonal antibody to B-lymphocyte stimulator.

    Science.gov (United States)

    2008-01-01

    Belimumab is a fully human monoclonal antibody that specifically recognizes and inhibits the biological activity of B-lymphocyte stimulator, or BLyS. Belimumab is in phase III trials for the treatment of systemic lupus erythematosus (SLE) and has completed a phase II trial in rheumatoid arthritis (RA); the product may also have potential in the treatment of other autoimmune disorders. In May 2001, Cambridge Antibody Technology (now MedImmune) completed its discovery programme and Human Genome Sciences identified belimumab as a candidate for clinical development. More than 1000 distinct human antibodies specific to BLyS were characterized by the collaboration.B-lymphocyte stimulator is a naturally occurring protein discovered by Human Genome Sciences that stimulates B-lymphocytes to develop into mature B cells. Laboratory studies have indicated that higher than normal levels of B-lymphocyte stimulator may contribute to the pathogenesis of autoimmune diseases, such as SLE and RA. Human Genome Sciences (HGS) and Cambridge Antibody Technology signed a collaborative agreement in August 1999 to study the B-lymphocyte stimulator as a human protein target. HGS is also developing other BLyS products. In March 2000, HGS and Cambridge Antibody Technology expanded their agreement into a 10-year collaboration and product development alliance, providing Human Genome Sciences with the right to use the antibody technology of Cambridge Antibody Technology to fully develop human antibodies for therapeutic and diagnostic purposes. Cambridge Antibody Technology will receive royalty payments on product sales from HGS, as well as the development and milestone payments it has already received. Belimumab will be manufactured in Human Genome Sciences' manufacturing facility, located in Rockville, MD, USA. HGS holds commercial rights to the drug. In July 2005, GlaxoSmithKline (GSK) exercised its co-development and co-promotion option to belimumab. In an agreement made in June 1996, HGS had

  5. Production and Purification of Polyclonal Antibodies.

    Science.gov (United States)

    Nakazawa, Masami; Mukumoto, Mari; Miyatake, Kazutaka

    2016-01-01

    Polyclonal antibodies consist of a mixture of antibodies produced by multiple B-cell clones that have differentiated into antibody-producing plasma cells in response to an immunogen. Polyclonal antibodies raised against an antigen recognize multiple epitopes on a target molecule, which results in a signal amplification in indirect immunoassays including immune-electron microscopy. In this chapter, we present a basic procedure to generate polyclonal antibodies in rabbits.

  6. Efficient generation of human IgA monoclonal antibodies.

    Science.gov (United States)

    Lorin, Valérie; Mouquet, Hugo

    2015-07-01

    Immunoglobulin A (IgA) is the most abundant antibody isotype produced in humans. IgA antibodies primarily ensure immune protection of mucosal surfaces against invading pathogens, but also circulate and are present in large quantities in blood. IgAs are heterogeneous at a molecular level, with two IgA subtypes and the capacity to form multimers by interacting with the joining (J) chain. Here, we have developed an efficient strategy to rapidly generate human IgA1 and IgA2 monoclonal antibodies in their monomeric and dimeric forms. Recombinant monomeric and dimeric IgA1/IgA2 counterparts of a prototypical IgG1 monoclonal antibody, 10-1074, targeting the HIV-1 envelope protein, were produced in large amounts after expression cloning and transient transfection of 293-F cells. 10-1074 IgAs were FPLC-purified using a novel affinity-based resin engrafted with anti-IgA chimeric Fabs, followed by a monomers/multimers separation using size exclusion-based FPLC. ELISA binding experiments confirmed that the artificial IgA class switching of 10-1074 did not alter its antigen recognition. In summary, our technical approach allows the very efficient production of various forms of purified recombinant human IgA molecules, which are precious tools in dissecting IgA B-cell responses in physiological and pathophysiological conditions, and studying the biology, function and therapeutic potential of IgAs.

  7. Monoclonal antibodies to intermediate filament proteins of human cells: unique and cross-reacting antibodies.

    Science.gov (United States)

    Gown, A M; Vogel, A M

    1982-11-01

    Monoclonal antibodies were generated against the intermediate filament proteins of different human cells. The reactivity of these antibodies with the different classes of intermediate filament proteins was determined by indirect immunofluorescence on cultured cells, immunologic indentification on SDS polyacrylamide gels ("wester blot" experiments), and immunoperoxidase assays on intact tissues. The following four antibodies are described: (a) an antivimentin antibody generated against human fibroblast cytoskeleton; (b), (c) two antibodies that recognize a 54-kdalton protein in human hepatocellular carcinoma cells; and (d) an antikeratin antibody made to stratum corneum that recognizes proteins of molecular weight 66 kdaltons and 57 kdaltons. The antivimentin antibody reacts with vimentin (58 kdaltons), glial fibrillary acidic protein (GFAP), and keratins from stratum corneum, but does not recognize hepatoma intermediate filaments. In immunofluorescence assays, the antibody reacts with mesenchymal cells and cultured epithelial cells that express vimentin. This antibody decorates the media of blood vessels in tissue sections. One antihepatoma filament antibody reacts only with the 54 kdalton protein of these cells and, in immunofluorescence and immunoperoxidase assays, only recognizes epithelial cells. It reacts with almost all nonsquamous epithelium. The other antihepatoma filament antibody is much less selective, reacting with vimentin, GFAP, and keratin from stratum corneum. This antibody decorates intermediate filaments of both mesenchymal and epithelial cells. The antikeratin antibody recognizes 66-kdalton and 57-kdalton proteins in extracts of stratum corneum and also identifies proteins of similar molecular weights in all cells tested. However, by immunofluorescence, this antibody decorates only the intermediate filaments of epidermoid carcinoma cells. When assayed on tissue sections, the antibody reacts with squamous epithelium and some, but not all

  8. Recommendations on risk-based strategies for detection and characterization of antibodies against biotechnology products.

    Science.gov (United States)

    Koren, Eugen; Smith, Holly W; Shores, Elizabeth; Shankar, Gopi; Finco-Kent, Deborah; Rup, Bonita; Barrett, Yu-Chen; Devanarayan, Viswanath; Gorovits, Boris; Gupta, Shalini; Parish, Thomas; Quarmby, Valerie; Moxness, Michael; Swanson, Steven J; Taniguchi, Gary; Zuckerman, Linda A; Stebbins, Christopher C; Mire-Sluis, Anthony

    2008-04-20

    The appropriate evaluation of the immunogenicity of biopharmaceuticals is of major importance for their successful development and licensure. Antibodies elicited by these products in many cases cause no detectable clinical effects in humans. However, antibodies to some therapeutic proteins have been shown to cause a variety of clinical consequences ranging from relatively mild to serious adverse events. In addition, antibodies can affect drug efficacy. In non-clinical studies, anti-drug antibodies (ADA) can complicate interpretation of the toxicity, pharmacokinetic (PK) and pharmacodynamic (PD) data. Therefore, it is important to develop testing strategies that provide valid assessments of antibody responses in both non-clinical and clinical studies. This document provides recommendations for antibody testing strategies stemming from the experience of contributing authors. The recommendations are intended to foster a more unified approach to antibody testing across the biopharmaceutical industry. The strategies proposed are also expected to contribute to better understanding of antibody responses and to further advance immunogenicity evaluation.

  9. Human Monoclonal Antibodies as a Countermeasure Against Botulinum Toxins

    Science.gov (United States)

    2012-11-30

    REPORT Human monoclonal antibodies as a countermeasure against Botulinum toxins 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: In this report, we...Prescribed by ANSI Std. Z39.18 - 31-Aug-2012 Human monoclonal antibodies as a countermeasure against Botulinum toxins Report Title ABSTRACT In this report...DTRA Final Report: Human monoclonal antibodies as a countermeasure against Botulinum toxins   Page 1 of 22 DTRA Final Report: Human monoclonal

  10. Production and characterization of antibody probes directed at constant regions of the alpha and beta subunit of the human T cell receptor.

    Science.gov (United States)

    Fabbi, M; Acuto, O; Bensussan, A; Poole, C B; Reinherz, E L

    1985-08-01

    To generate antibodies directed at constant regions of the human T cell receptor, purified alpha and beta subunits of a human T cell antigen/major histocompatibility complex receptor from the REX tumor (Ti-REX) were isolated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and utilized to immunize rabbits. H36 (anti-alpha subunit) and H38 (anti-beta subunit) antisera were strongly reactive with the denatured subunits and also immunoprecipitated the Ti heterodimer from 125I surface-labeled lysates of REX, inducer, suppressor and cytotoxic T cell clones, peripheral T lymphocytes and thymocytes. Moreover, immunodepletion experiments showed that such antisera recognized antigenic determinant(s) shared by all Ti molecules expressed in the thymus. Several observations were made with these anticonstant region antibodies. First, peptide map analysis showed that the T cell receptor molecules recognized by the anti-clonotype and the anti-constant region heteroantisera on a given T cell clone are identical, thus supporting the view that the T cell receptor undergoes allelic exclusion. Second, since the individual antisera were weakly cross-reactive with the other denatured subunit, such subunits probably share conserved sequences. Third, the absence of antisera reactivity with intact cells implies that most of these constant region epitopes must be obscured by associated molecules, perhaps including one or more of the 20-25-kDa T3 subunits. Fourth, the extensive difference in two-dimensional peptide maps of Ti alpha subunits from clones of differing specificities makes it likely that the subunit contributes in a major way to antigen/major histocompatibility complex binding.

  11. Antibody Production in Plants and Green Algae.

    Science.gov (United States)

    Yusibov, Vidadi; Kushnir, Natasha; Streatfield, Stephen J

    2016-04-29

    Monoclonal antibodies (mAbs) have a wide range of modern applications, including research, diagnostic, therapeutic, and industrial uses. Market demand for mAbs is high and continues to grow. Although mammalian systems, which currently dominate the biomanufacturing industry, produce effective and safe recombinant mAbs, they have a limited manufacturing capacity and high costs. Bacteria, yeast, and insect cell systems are highly scalable and cost effective but vary in their ability to produce appropriate posttranslationally modified mAbs. Plants and green algae are emerging as promising production platforms because of their time and cost efficiencies, scalability, lack of mammalian pathogens, and eukaryotic posttranslational protein modification machinery. So far, plant- and algae-derived mAbs have been produced predominantly as candidate therapeutics for infectious diseases and cancer. These candidates have been extensively evaluated in animal models, and some have shown efficacy in clinical trials. Here, we review ongoing efforts to advance the production of mAbs in plants and algae.

  12. Human productivity program definition

    Science.gov (United States)

    Cramer, D. B.

    1985-01-01

    The optimization of human productivity on the space station within the existing resources and operational constraints is the aim of the Human Productivity Program. The conceptual objectives of the program are as follows: (1) to identify long lead technology; (2) to identify responsibility for work elements; (3) to coordinate the development of crew facilities and activities; and (4) to lay the foundation for a cost effective approach to improving human productivity. Human productivity work elements are also described and examples are presented.

  13. [Human single chain antibodies directed to tumor necrosis factor].

    Science.gov (United States)

    Vikhrova, M A; Batanova, T A; Lebedev, L R; Shingarova, L N; Frank, L A; Kirpichnikov, M P; Tikunova, N V

    2011-01-01

    Six unique phage antibodies to human TNF have been selected from a combinatorial library of human single chain fragment variable. ELISA and Western-blotting was used to study selected phage antibodies binding with TNF. The specificity of selected antibodies was determined by binding with interferon alpha and gamma, bovine serum albumin, ovalbumin and ubiquitin. Two antibodies, sA1 and sB3, were converted into a soluble single-chain antibody form and their affinity was 2.5 and 13.7 nM respectively.

  14. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression

    OpenAIRE

    Haredy, AM; Nishizawa, A.; Honda, K.; T. Ohya; Ohtake, H; Omasa, T

    2013-01-01

    To improve antibody production in Chinese hamster ovary (CHO) cells, the humanized antibody-producing CHO DP-12-SF cell line was transfected with the gene encoding activating transcription factor 4 (ATF4), a central factor in the unfolded protein response. Overexpression of ATF4 significantly enhanced the production of antibody in the CHO DP-12-SF cell line. The specific IgG production rate of in the ATF4-overexpressing CHO-ATF4-16 cells was approximately 2.4 times that of the parental host c...

  15. Human immunodeficiency virus antibodies and the vaccine problem.

    Science.gov (United States)

    Chiodi, F; Weiss, R A

    2014-05-01

    Despite the great advances made in controlling human immunodeficiency virus type 1 (HIV-1) infection with antiretroviral drug treatment, a safe and efficacious HIV vaccine has yet to be developed. Here, we discuss why clinical trials and vaccine development for HIV have so far been disappointing, with an emphasis on the lack of protective antibodies. We review approaches for developing appropriate HIV immunogens and the stimulation of long-lasting B-cell responses with antibody maturation. We conclude that candidate reagents in the pipeline for HIV vaccine development are unlikely to be particularly effective. Although the major funders of HIV vaccine research and development are placing increasing emphasis on clinical product development, a genuine breakthrough in preventing HIV infection through vaccines is more likely to come from novel immunogen research.

  16. Construction of human antibody gene libraries and selection of antibodies by phage display.

    Science.gov (United States)

    Frenzel, André; Kügler, Jonas; Wilke, Sonja; Schirrmann, Thomas; Hust, Michael

    2014-01-01

    Antibody phage display is the most commonly used in vitro selection technology and has yielded thousands of useful antibodies for research, diagnostics, and therapy.The prerequisite for successful generation and development of human recombinant antibodies using phage display is the construction of a high-quality antibody gene library. Here, we describe the methods for the construction of human immune and naive scFv gene libraries.The success also depends on the panning strategy for the selection of binders from these libraries. In this article, we describe a panning strategy that is high-throughput compatible and allows parallel selection in microtiter plates.

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

    Science.gov (United States)

    Hart, Felix; Danielczyk, Antje; Goletz, Steffen

    2017-01-01

    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.

  18. 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.

  19. A monoclonal antibody against human MUDENG protein.

    Science.gov (United States)

    Wagley, Yadav; Choi, Jun-Ha; Wickramanayake, Dimuthu Dhammika; Choi, Geun-Yeol; Kim, Chang-Kyu; Kim, Tae-Hyoung; Oh, Jae-Wook

    2013-08-01

    MUDENG (mu-2-related death-inducing gene, MuD) encodes a predicted ∼54-kDa protein in humans, considered to be involved in trafficking proteins from endosomes toward other membranous compartments as well as in inducing cell death. Here we report on the generation of a mouse monoclonal antibody (MAb) against the middle domain of human (h) MuD. This IgG sub 1 MAb, named M3H9, recognizes residues 244-326 in the middle domain of the MuD protein. Thus, the MuD proteins expressed in an astroglioma cell line and primary astrocytes can be detected by the M3H9 MAb. We showed that M3H9 MAb can be useful in enzyme-linked immunosorbent assay (ELISA) and immunoblot experiments. In addition, M3H9 MAb can detect the expression of the MuD protein in formalin-fixed, paraffin-embedded mouse ovary and uterus tissues. These results indicate that the MuD MAb M3H9 could be useful as a new biomarker of hereditary spastic paraplegia and other related diseases.

  20. Characteristics of human cell line, F2N78, for the production of recombinant antibody in fed-batch and perfusion cultures.

    Science.gov (United States)

    Seo, Joon Serk; Min, Byung Sub; Kwon, Young-Bum; Lee, Soo-Young; Cho, Jong-Moon; Park, Keun-Hee; Yang, Yae Ji; Maeng, Ki Eun; Chang, Shin-Jae; Kim, Dong-Il

    2016-03-01

    A human hybrid cell line, F2N78, was developed by somatic fusion of HEK293 and Namalwa cells for the production recombinant biopharmaceutical proteins. In this study, we performed perfusion culture to verify its potential in culture process used for human cell expression platform. Cell viability could be maintained over 90% and high viable cell density was obtained at higher than 1.0 × 10(7) cells/mL by bleeding process in perfusion culture. The cells were adapted well in both culture modes, but there were apparent differences in protein quality. Compared to fed-batch culture, degalactosylated forms such as G0F and G0 as well as Man5 showed no significant increases in perfusion culture. In terms of charge variants, acidic peaks increased, whereas main peaks constantly decreased according to the length of culture period in both methods.

  1. Engineering human cells for in vivo secretion of antibody and non-antibody therapeutic proteins.

    Science.gov (United States)

    Sánchez-Martín, David; Sanz, Laura; Álvarez-Vallina, Luis

    2011-12-01

    Purified proteins such as antibodies are widely used as therapeutic agents in clinical medicine. However, clinical-grade proteins for therapeutic use require sophisticated technologies and are extremely expensive to produce. In vivo secretion of therapeutic proteins by genetically engineered human cells may advantageously replace injection of highly purified proteins. The use of gene transfer methods circumvents problems related to large-scale production and purification and offers additional benefits by achieving sustained concentrations of therapeutic protein with a syngenic glycosylation pattern that make the protein potentially less immunogenic. The feasibility of the in vivo production of therapeutic proteins by diverse cells/tissues has now been demonstrated using different techniques, such as ex vivo genetically modified cells and in vivo gene transfer mediated by viral vectors.

  2. Development and characterization of a monoclonal antibody specific for human basophils and the identification of a unique secretory product of basophil activation.

    Science.gov (United States)

    McEuen, A R; Buckley, M G; Compton, S J; Walls, A F

    1999-01-01

    Despite increasing evidence that basophils can infiltrate into inflamed tissues during allergic reactions, determination of the extent of infiltration and elucidation of their role in allergic disease has been frustrated by the lack of reliable means for detecting this cell type in tissues. In the present study, we report on a new monoclonal antibody specific for basophils and on the initial characterization of the antigen it recognizes. Basophils were isolated from peripheral blood by Percoll density gradient centrifugation and a positive-selection immunomagnetic procedure and injected into mice to produce monoclonal antibodies. A hybridoma clone, designated BB1, secreted antibody of the IgG2a isotype; this antibody bound selectively to basophils on immunocytochemistry but did not react with any other cell type or tissue structure, although it did stain a proportion of cells from the basophilic cell line KU812F. In sections of mixed populations of peripheral blood cells, similar numbers of cells stained with Alcian blue dye and BB1 over a wide range of basophil purity. BB1 antibody was effective in identifying basophils in sections of mixed cells or in tissues after fixation with ethanol, Carnoy's solution, or formalin. Staining of basophils with BB1 gave a granular appearance, although flow cytometry indicated that some antigen was also present on the surface of the cell. Activation of these cells with anti-IgE antibody or with the calcium ionophore A23187 provoked release of the antigen in parallel with that of histamine. BB1 antibody did not, by itself, stimulate histamine release. The molecular mass of the antigen was determined on Hedrick-Smith gels to be 124+/-11 kd. This new monoclonal antibody will be a valuable experimental tool in future studies, allowing the reliable detection of basophils in tissues of patients with allergic and chronic inflammatory disease; in addition, the antigen it identifies has potential as a unique marker of basophil activation.

  3. 9 CFR 113.450 - General requirements for antibody products.

    Science.gov (United States)

    2010-01-01

    ... “monoclonal” shall be used. Example: “Duck Virus Hepatitis Antibody, Duck Origin.” (2) Bacterium-specific... “monoclonal” shall be used. Example: “Escherichia Coli Monoclonal Antibody, Murine Origin.” (3) Failure of... products. Retests shall be conducted as deemed necessary by the Administrator. (i) Before first use, horses...

  4. 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

    1999-01-01

    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 kil

  5. Polyclonal Antibody Production for Membrane Proteins via Genetic Immunization.

    Science.gov (United States)

    Hansen, Debra T; Robida, Mark D; Craciunescu, Felicia M; Loskutov, Andrey V; Dörner, Katerina; Rodenberry, John-Charles; Wang, Xiao; Olson, Tien L; Patel, Hetal; Fromme, Petra; Sykes, Kathryn F

    2016-02-24

    Antibodies are essential for structural determinations and functional studies of membrane proteins, but antibody generation is limited by the availability of properly-folded and purified antigen. We describe the first application of genetic immunization to a structurally diverse set of membrane proteins to show that immunization of mice with DNA alone produced antibodies against 71% (n = 17) of the bacterial and viral targets. Antibody production correlated with prior reports of target immunogenicity in host organisms, underscoring the efficiency of this DNA-gold micronanoplex approach. To generate each antigen for antibody characterization, we also developed a simple in vitro membrane protein expression and capture method. Antibody specificity was demonstrated upon identifying, for the first time, membrane-directed heterologous expression of the native sequences of the FopA and FTT1525 virulence determinants from the select agent Francisella tularensis SCHU S4. These approaches will accelerate future structural and functional investigations of therapeutically-relevant membrane proteins.

  6. CONSTRUCTION AND EXPRESSION OF A HUMAN-MOUSE CHIMERIC ANTIBODY AGAINST HUMAN BLADDER CANCER

    Institute of Scientific and Technical Information of China (English)

    白银; 王琰; 周丽君; 俞莉章

    2001-01-01

    To construct and express a human-mouse chimeric antibody against human bladder cancer. Method: The variable region genes of anti-human bladder cancer monoclonal antibody BDI-1 were cloned by RT-PCR. A human-mouse chimeric antibody expression vector was constructed and transfected into CHO cells. The chimeric antibody against bladder cancer was expressed and characterized. Result: Eukaryotic expression vector of the chimeric antibody against human bladder carcinoma was successfully constructed, and was expressed in eukaryotic cells; the expressed chimeric antibody ch-BDI showed same specificity as its parent McAb against human bladder cancer cells. Conclusion: The constructed chimeric antibody was expressed successfully in eukaryotic cells, and the chimeric antibody had desired affinity against human bladder cancer cells.

  7. Cell-Free Synthesis Meets Antibody Production: A Review

    Directory of Open Access Journals (Sweden)

    Marlitt Stech

    2015-01-01

    Full Text Available Engineered antibodies are key players in therapy, diagnostics and research. In addition to full size immunoglobulin gamma (IgG molecules, smaller formats of recombinant antibodies, such as single-chain variable fragments (scFv and antigen binding fragments (Fab, have emerged as promising alternatives since they possess different advantageous properties. Cell-based production technologies of antibodies and antibody fragments are well-established, allowing researchers to design and manufacture highly specific molecular recognition tools. However, as these technologies are accompanied by the drawbacks of being rather time-consuming and cost-intensive, efficient and powerful cell-free protein synthesis systems have been developed over the last decade as alternatives. So far, prokaryotic cell-free systems have been the focus of interest. Recently, eukaryotic in vitro translation systems have enriched the antibody production pipeline, as these systems are able to mimic the natural pathway of antibody synthesis in eukaryotic cells. This review aims to overview and summarize the advances made in the production of antibodies and antibody fragments in cell-free systems.

  8. Mechanism of human antibody-mediated neutralization of Marburg virus.

    Science.gov (United States)

    Flyak, Andrew I; Ilinykh, Philipp A; Murin, Charles D; Garron, Tania; Shen, Xiaoli; Fusco, Marnie L; Hashiguchi, Takao; Bornholdt, Zachary A; Slaughter, James C; Sapparapu, Gopal; Klages, Curtis; Ksiazek, Thomas G; Ward, Andrew B; Saphire, Erica Ollmann; Bukreyev, Alexander; Crowe, James E

    2015-02-26

    The mechanisms by which neutralizing antibodies inhibit Marburg virus (MARV) are not known. We isolated a panel of neutralizing antibodies from a human MARV survivor that bind to MARV glycoprotein (GP) and compete for binding to a single major antigenic site. Remarkably, several of the antibodies also bind to Ebola virus (EBOV) GP. Single-particle EM structures of antibody-GP complexes reveal that all of the neutralizing antibodies bind to MARV GP at or near the predicted region of the receptor-binding site. The presence of the glycan cap or mucin-like domain blocks binding of neutralizing antibodies to EBOV GP, but not to MARV GP. The data suggest that MARV-neutralizing antibodies inhibit virus by binding to infectious virions at the exposed MARV receptor-binding site, revealing a mechanism of filovirus inhibition.

  9. Discovery of diverse and functional antibodies from large human repertoire antibody libraries.

    Science.gov (United States)

    Schwimmer, Lauren J; Huang, Betty; Giang, Hoa; Cotter, Robyn L; Chemla-Vogel, David S; Dy, Francis V; Tam, Eric M; Zhang, Fangjiu; Toy, Pamela; Bohmann, David J; Watson, Susan R; Beaber, John W; Reddy, Nithin; Kuan, Hua-Feng; Bedinger, Daniel H; Rondon, Isaac J

    2013-05-31

    Phage display antibody libraries have a proven track record for the discovery of therapeutic human antibodies, increasing the demand for large and diverse phage antibody libraries for the discovery of new therapeutics. We have constructed naïve antibody phage display libraries in both Fab and scFv formats, with each library having more than 250 billion clones that encompass the human antibody repertoire. These libraries show high fidelity in open reading frame and expression percentages, and their V-gene family distribution, VH-CDR3 length and amino acid usage mirror the natural diversity of human antibodies. Both the Fab and scFv libraries show robust sequence diversity in target-specific binders and differential V-gene usage for each target tested, supporting the use of libraries that utilize multiple display formats and V-gene utilization to maximize antibody-binding diversity. For each of the targets, clones with picomolar affinities were identified from at least one of the libraries and for the two targets assessed for activity, functional antibodies were identified from both libraries.

  10. Automated pipeline for rapid production and screening of HIV-specific monoclonal antibodies using pichia pastoris.

    Science.gov (United States)

    Shah, Kartik A; Clark, John J; Goods, Brittany A; Politano, Timothy J; Mozdzierz, Nicholas J; Zimnisky, Ross M; Leeson, Rachel L; Love, J Christopher; Love, Kerry R

    2015-12-01

    Monoclonal antibodies (mAbs) that bind and neutralize human pathogens have great therapeutic potential. Advances in automated screening and liquid handling have resulted in the ability to discover antigen-specific antibodies either directly from human blood or from various combinatorial libraries (phage, bacteria, or yeast). There remain, however, bottlenecks in the cloning, expression and evaluation of such lead antibodies identified in primary screens that hinder high-throughput screening. As such, "hit-to-lead identification" remains both expensive and time-consuming. By combining the advantages of overlap extension PCR (OE-PCR) and a genetically stable yet easily manipulatable microbial expression host Pichia pastoris, we have developed an automated pipeline for the rapid production and screening of full-length antigen-specific mAbs. Here, we demonstrate the speed, feasibility and cost-effectiveness of our approach by generating several broadly neutralizing antibodies against human immunodeficiency virus (HIV).

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

    Science.gov (United States)

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

    2012-12-01

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

  12. Recombinant mouse interferon-gamma regulation of antibody production.

    OpenAIRE

    1983-01-01

    Interferon-gamma produced in monkey cells by transfection with mouse interferon-gamma cDNA suppressed the mouse in vitro antibody response in a manner similar to that of natural mouse interferon-gamma. Significant suppression was obtained with as little as 1 U of interferon. Recombinant human interferon-gamma produced by cloning in a similar fashion was not suppressive. Both the suppressive and the antiviral activities of recombinant interferon-gamma were neutralized by antibodies to mouse na...

  13. High throughput production of mouse monoclonal antibodies using antigen microarrays

    DEFF Research Database (Denmark)

    De Masi, Federico; Chiarella, P.; Wilhelm, H.;

    2005-01-01

    Recent advances in proteomics research underscore the increasing need for high-affinity monoclonal antibodies, which are still generated with lengthy, low-throughput antibody production techniques. Here we present a semi-automated, high-throughput method of hybridoma generation and identification....... Monoclonal antibodies were raised to different targets in single batch runs of 6-10 wk using multiplexed immunisations, automated fusion and cell-culture, and a novel antigen-coated microarray-screening assay. In a large-scale experiment, where eight mice were immunized with ten antigens each, we generated...

  14. Sperm-immobilizing monoclonal antibody to human seminal plasma antigens.

    Science.gov (United States)

    Shigeta, M; Watanabe, T; Maruyama, S; Koyama, K; Isojima, S

    1980-01-01

    Rat spleen cells immunized to human azoospermic semen (a mixture of seminal plasma components) and mouse myeloma cells (P3/X63 Ag8U1; P3U1) (Marguilies et al., 1976) were successfully fused with polyethylene glycol (PEG 1500) and 19 of 89 fused cell cultures were found to produce sperm-immobilizing antibody. The cells that produced antibody indicating the highest sperm-immobilizing activity were distributed into wells for further recloning and 10 clones producing sperm-immobilizing antibody were established. The clone (1C4) producing the highest antibody titre was found to produce a large amount of IgG in culture supernatants and to contain a mixture of rat and mouse chromosomes. It was proved by immunodiffusion test that the monoclonal antibody was produced to the human seminal plasma antigen No. 7 which is common to human milk protein. Using this hybridoma which produced a large amount of monoclonal sperm-immobilizing antibody, a new method could be developed for purifying human seminal plasma antigen by immunoaffinity chromatography with bound antibody from the hybridoma. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6783353

  15. Probiotics stimulate production of natural antibodies in chickens.

    Science.gov (United States)

    Haghighi, Hamid R; Gong, Jianhua; Gyles, Carlton L; Hayes, M Anthony; Zhou, Huaijun; Sanei, Babak; Chambers, James R; Sharif, Shayan

    2006-09-01

    Commensal bacteria in the intestine play an important role in the development of immune response. These bacteria interact with cells of the gut-associated lymphoid tissues (GALT). Among cells of the GALT, B-1 cells are of note. These cells are involved in the production of natural antibodies. In the present study, we determined whether manipulation of the intestinal microbiota by administration of probiotics, which we had previously shown to enhance specific systemic antibody response, could affect the development of natural antibodies in the intestines and sera of chickens. Our findings demonstrate that when 1-day-old chicks were treated with probiotics, serum and intestinal antibodies reactive to tetanus toxoid (TT) and Clostridium perfringens alpha-toxin in addition to intestinal immunoglobulin A (IgA) reactive to bovine serum albumin (BSA) were increased in unimmunized chickens. Moreover, IgG antibodies reactive to TT were increased in the intestines of probiotic-treated chickens compared to those of untreated controls. In serum, IgG and IgM reactive to TT and alpha-toxin were increased in probiotic-treated, unimmunized chickens compared to levels in untreated controls. However, no significant difference in serum levels of IgM or IgG response to BSA was observed. These results are suggestive of the induction of natural antibodies in probiotic-treated, unimmunized chickens. Elucidating the role of these antibodies in maintenance of the chicken immune system homeostasis and immune response to pathogens requires further investigation.

  16. Competency development in antibody production in cancer cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Park, M.S.

    1998-12-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The main objective of this project was to develop a rapid recombinant antibody production technology. To achieve the objective, the authors employed (1) production of recombinant antigens that are important for cell cycle regulation and DNA repair, (2) immunization and specific selection of antibody-producing lymphocytes using the flow cytometry and magnetic bead capturing procedure, (3) construction of single chain antibody library, (4) development of recombinant vectors that target, express, and regulate the expression of intracellular antibodies, and (5) specific inhibition of tumor cell growth in tissue culture. The authors have accomplished (1) optimization of a selection procedure to isolate antigen-specific lymphocytes, (2) optimization of the construction of a single-chain antibody library, and (3) development of a new antibody expression vector for intracellular immunization. The future direction of this research is to continue to test the potential use of the intracellular immunization procedure as a tool to study functions of biological molecules and as an immuno-cancer therapy procedure to inhibit the growth of cancer cells.

  17. Antigen recognition by IgG4 antibodies in human trichinellosis

    Directory of Open Access Journals (Sweden)

    Pinelli E.

    2001-06-01

    Full Text Available The antibody isotype response to Trichinella spiralis excretory/secretory (ES products of muscle larva was examined using sera from patients with confirmed trichinellosis. Using Western blots we identify components of the ES antigen that are recognized by IgM and IgG antibodies. A 45 kDa component was strongly recognized by different antibody classes and subclasses. We observed a 45 kDa-specific lgG4 response that was detected exclusively using sera of patients with trichinellosis and not of patients with echinococcosis, filariasis, cysticercosis, ascariasis, strongyloidiasis or toxocariasis. These results are relevant for the diagnosis of human trichinellosis.

  18. Activated human nasal epithelial cells modulate specific antibody response against bacterial or viral antigens.

    Directory of Open Access Journals (Sweden)

    Chiou-Yueh Yeh

    Full Text Available Nasal mucosa is an immune responsive organ evidenced by eliciting both specific local secretory IgA and systemic IgG antibody responses with intra-nasal administration of antigens. Nevertheless, the role of nasal epithelial cells in modulating such responses is unclear. Human nasal epithelial cells (hNECs obtained from sinus mucosa of patients with chronic rhinosinusitis were cultured in vitro and firstly were stimulated by Lactococcus lactis bacterium-like particles (BLPs in order to examine their role on antibody production. Secondly, both antigens of immunodominant protein IDG60 from oral Streptococcus mutans and hemagglutinin (HA from influenza virus were tested to evaluate the specific antibody response. Stimulated hNECs by BLPs exhibited a significant increase in the production of interleukin-6 (IL-6, and thymic stromal lymphopoietin (TSLP. Conditioned medium of stimulated hNECs has effects on enhancing the proliferation of CD4+ T cells together with interferon-γ and IL-5 production, increasing the costimulatory molecules on dendritic cells and augmenting the production of IDG60 specific IgA, HA specific IgG, IgA by human peripheral blood lymphocytes. Such production of antigen specific IgG and IgA is significantly counteracted in the presence of IL-6 and TSLP neutralizing antibodies. In conclusion, properly stimulated hNECs may impart immuno-modulatory effects on the antigen-specific antibody response at least through the production of IL-6 and TSLP.

  19. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression.

    Science.gov (United States)

    Haredy, Ahmad M; Nishizawa, Akitoshi; Honda, Kohsuke; Ohya, Tomoshi; Ohtake, Hisao; Omasa, Takeshi

    2013-12-01

    To improve antibody production in Chinese hamster ovary (CHO) cells, the humanized antibody-producing CHO DP-12-SF cell line was transfected with the gene encoding activating transcription factor 4 (ATF4), a central factor in the unfolded protein response. Overexpression of ATF4 significantly enhanced the production of antibody in the CHO DP-12-SF cell line. The specific IgG production rate of in the ATF4-overexpressing CHO-ATF4-16 cells was approximately 2.4 times that of the parental host cell line. Clone CHO-ATF4-16 did not show any change in growth rate compared with the parental cells or mock-transfected CHO-DP12-SF cells. The expression levels of mRNAs encoding both the antibody heavy and light chains in the CHO-ATF4-16 clone were analyzed. This analysis showed that ATF4 overexpression improved the total production and specific production rate of antibody without affecting the mRNA transcription level. These results indicate that ATF4 overexpression is a promising method for improving recombinant IgG production in CHO cells.

  20. Cell culture processes for monoclonal antibody production.

    Science.gov (United States)

    Li, Feng; Vijayasankaran, Natarajan; Shen, Amy Yijuan; Kiss, Robert; Amanullah, Ashraf

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including 1) cell lines capable of synthesizing the required molecules at high productivities that ensure low operating cost; 2) culture media and bioreactor culture conditions that achieve both the requisite productivity and meet product quality specifications; 3) appropriate on-line and off-line sensors capable of providing information that enhances process knowledge; and 4) good understanding of culture performance at different scales to ensure smooth scale-up. Successful implementation also requires appropriate strategies for process development, scale-up and process characterization and validation that enable robust operation that is compliant with current regulations. This review provides an overview of the state-of-the art technology in key aspects of cell culture, e.g., engineering of highly productive cell lines and optimization of cell culture process conditions. We also summarize the current thinking on appropriate process development strategies and process advances that might affect process development.

  1. Cell culture processes for monoclonal antibody production

    Science.gov (United States)

    Li, Feng; Vijayasankaran, Natarajan; Shen, Amy (Yijuan); Kiss, Robert

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including (1) cell lines capable of synthesizing the required molecules at high productivities that ensure low operating cost; (2) culture media and bioreactor culture conditions that achieve both the requisite productivity and meet product quality specifications; (3) appropriate on-line and off-line sensors capable of providing information that enhances process control; and (4) good understanding of culture performance at different scales to ensure smooth scale-up. Successful implementation also requires appropriate strategies for process development, scale-up and process characterization and validation that enable robust operation and ensure compliance with current regulations. This review provides an overview of the state-of-the art technology in key aspects of cell culture, e.g., generation of highly productive cell lines and optimization of cell culture process conditions. We also summarize the current thinking on appropriate process development strategies and process advances that might affect process development. PMID:20622510

  2. Development of mass spectrometry based techniques for the identification and determination of compositional variability in recombinant polyclonal antibody products.

    Science.gov (United States)

    Persson, Pia; Engström, Anders; Rasmussen, Lone K; Holmberg, Erland; Frandsen, Torben P

    2010-09-01

    Recombinant polyclonal antibodies are a new class of protein biologics, combining a defined number of target-specific antibodies, developed for therapeutic use across various indications. Development, manufacture, and release of recombinant polyclonal antibodies as well characterized biological products have required development of new chemistry, manufacturing, and control (CMC) technologies. Sym001 is a recombinant polyclonal antibody product containing 25 unique antibodies specific for the Rhesus D antigen. Sym001 drug substance is manufactured using a single batch technology, Sympress. Here, we describe the development of two novel mass spectrometry based methods that allows identification of individual antibodies in the Sym001 drug substance, through the determination of unique marker peptides or antibody light chains. The two methods provide an unambiguous identification of the 25 unique antibodies comprised in the Sym001 drug substance. Furthermore, the light chain liquid chromatography-mass spectrometry (LC-MS) method has been developed to allow the determination of the relative distribution of the 25 antibodies. The light chain LC-MS method has demonstrated linearity, specificity, precision, and accuracy, thus qualifying it for use in the quality control of recombinant polyclonal antibodies for human use. The development of such quantitative methods is central for the development and quality control of additional therapeutic recombinant polyclonal antibody products.

  3. The effects of propolis on antibody production by laying hens.

    Science.gov (United States)

    Freitas, J A; Vanat, N; Pinheiro, J W; Balarin, M R S; Sforcin, J M; Venancio, E J

    2011-06-01

    Propolis is a honeybee product showing several biological properties that enhance the immune response, depending on the concentration and intake period. Because propolis possesses an immunomodulatory action on mammals, the objective of our study was to investigate the effects of propolis on the humoral immune response of laying hens by evaluating antibody production. Laying hens (ISA Brown) were divided into 5 groups with 7 birds each. Group 1 was a nonimmunized control, whereas birds in group 2 were immunized intravenously with SRBC, and those in groups 3, 4, and 5 were treated intraperitoneally with propolis (2, 10, and 50 mg/kg, respectively) on 3 consecutive days and then inoculated intravenously with SRBC. Hematological and serological analyses were carried out on d 0, 3, and 38. Natural and specific antibody levels were determined by hemagglutination with rabbit red blood cells and SRBC, respectively. Propolis-treated birds (50 mg/kg) showed a significant decline in heterophils and in the heterophil:lymphocyte ratio. After SRBC immunization, significant increases in levels of IgG were observed in groups 4 and 5. Furthermore, higher levels of natural antibodies were observed in propolis-treated laying hens. The administration of propolis to laying hens increased the production of IgG specific to SRBC and natural antibodies, and could be used to increase antigen-specific antibody responses to vaccines.

  4. Antibody production in early life supported by maternal lymphocyte factors.

    Science.gov (United States)

    Shimamura, Michio; Huang, Yi-Ying; Goji, Hiroshi

    2003-01-20

    To examine the influence of maternal lymphocyte factors on the immune responses in offspring in early life, antibody production in neonates born to either normal or lymphocyte-deficient mothers was analyzed. Recombination activating gene (Rag)-2(+/-) mouse neonates born to Rag-2(+/+), Rag-2(+/-)or Rag-2(-/-)mothers were injected with goat anti-mouse IgD antiserum, and IgE and IgG(1) production was evaluated. The levels of IgE and IgG(1) were higher in the pups born to Rag-2(+/+)and Rag-2(+/-) dams than to lymphocyte-deficient Rag-2(-/-) dams. The enhanced antibody production in the former compared with the latter neonates was also found following immunization with ovalbumin or TNP-Ficoll. Thus, the presence of maternal lymphocyte factors was suggested in neonates that augmented antigen-specific antibody production in both T cell-dependent and -independent pathways. A reduction in antibody production was observed in normal neonates when they were foster-nursed by Rag-2(-/-) mothers. Thus, the maternal lymphocyte factors enhancing the immune responses in newborns were shown to be present in breast-milk.

  5. Anti-epitope antibody,a novel site-directed antibody against human acetylcholinesterase

    Institute of Scientific and Technical Information of China (English)

    Xing-mei ZHANG; Gang LIU; Man-ji SUN

    2004-01-01

    AIM: To construct synthetic antigens using the epitope of human brain acetylcholinesterase (hbAChE) for induction and detection of the specific antibody against the epitope, and to analyse the immunogenicity of the antibody.METHODS: The epitope (RTVLVSMNYR, amino acids 143-152) of hbAChE was chemically synthesized, coupled with the carrier protein keyhole limpet hemocyanin (KLH) to construct an artificial immunogen (KLH-epitope), and injected into rabbits to raise antibody. The epitope conjugated with bovine serum albumin (BSA) was used as the detection antigen. The specificity of the antibody was tested by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The immunoreaction between the anti-recombinant human butyrylcholinesterase (rhBChE)polyclonal antibody and the biotinylated-epitope was examined by indirect ELISA. RESULTS: The erythrocyte AChE, the hbAChE, rhBChE and the BSA-epitope all immunoreacted with the anti-epitope antibody against the epitope (143-152) of hbAChE, whereas the torpedo AChE did not. CONCLUSION: The hbAChE, the human erythrocyte AChE and hBChE share the conservative antigenic epitope RTVLVSMNYR, hence they can all immunoreact with the anti-epitope antibody. Since the epitope of hbAChE is less similar with the aligned amino acid sequences of AChE of Torpedo californica or Torpedo marmorata, there is not any immunoreactivity between them. The R, M, and N residues in the epitope seem to be necessary radicals for the conservation of antigenicity.

  6. Monoclonal antibody disulfide reduction during manufacturing: Untangling process effects from product effects.

    Science.gov (United States)

    Hutterer, Katariina M; Hong, Robert W; Lull, Jonathon; Zhao, Xiaoyang; Wang, Tian; Pei, Rex; Le, M Eleanor; Borisov, Oleg; Piper, Rob; Liu, Yaoqing Diana; Petty, Krista; Apostol, Izydor; Flynn, Gregory C

    2013-01-01

    Manufacturing-induced disulfide reduction has recently been reported for monoclonal human immunoglobulin gamma (IgG) antibodies, a widely used modality in the biopharmaceutical industry. This effect has been tied to components of the intracellular thioredoxin reduction system that are released upon cell breakage. Here, we describe the effect of process parameters and intrinsic molecule properties on the extent of reduction. Material taken from cell cultures at the end of production displayed large variations in the extent of antibody reduction between different products, including no reduction, when subjected to the same reduction-promoting harvest conditions. Additionally, in a reconstituted model in which process variables could be isolated from product properties, we found that antibody reduction was dependent on the cell line (clone) and cell culture process. A bench-scale model using a thioredoxin/thioredoxin reductase regeneration system revealed that reduction susceptibility depended on not only antibody class but also light chain type; the model further demonstrates that the trend in reducibility was identical to DTT reduction sensitivity following the order IgG1λ > IgG1κ > IgG2λ > IgG2κ. Thus, both product attributes and process parameters contribute to the extent of antibody reduction during production.

  7. Cell culture processes for monoclonal antibody production

    OpenAIRE

    LI Feng; Vijayasankaran, Natarajan; Shen, Amy (Yijuan); Kiss, Robert; Amanullah, Ashraf

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including (1) cell lines capable of synthesizin...

  8. Antidotes, antibody-mediated immunity and the future of pharmaceutical product development.

    Science.gov (United States)

    Caoili, Salvador Eugenio C

    2013-02-01

    If new scientific knowledge is to be more efficiently generated and applied toward the advancement of health, human safety must be more effectively addressed in the conduct of research. Given the present difficulties of accurately predicting biological outcomes of novel interventions in vivo, the imperative of human safety suggests the development of novel pharmaceutical products in tandem with their prospective antidotes in anticipation of possible adverse events, to render the risks of initial clinical trials more acceptable from a regulatory standpoint. Antibody-mediated immunity provides a generally applicable mechanistic basis for developing antidotes to both biologicals and small-molecule drugs (such that antibodies may serve as antidotes to pharmaceutical agents as a class including other antibodies) and also for the control and prevention of both infectious and noninfectious diseases via passive or active immunization. Accordingly, the development of prophylactic or therapeutic passive-immunization strategies using antipeptide antibodies is a plausible prelude to the development of corresponding active-immunization strategies using peptide-based vaccines. In line with this scheme, global proliferation of antibody- and vaccine-production technologies, especially those that obviate dependence on the cold chain for storage and transport of finished products, could provide geographically distributed breakout capability against emerging and future health challenges.

  9. Probing cocaine-antibody interactions in buffer and human serum.

    Directory of Open Access Journals (Sweden)

    Muthu Ramakrishnan

    Full Text Available BACKGROUND: Despite progress in cocaine immunotherapy, the kinetic and thermodynamic properties of antibodies which bind to cocaine and its metabolites are not well understood. It is also not clear how the interactions between them differ in a complex matrix such as the serum present in the human body. In the present study, we have used microscale thermophoresis (MST, isothermal titration calorimetry (ITC, and surface plasmon resonance (SPR we have evaluated the affinity properties of a representative mouse monoclonal (mAb08 as well as those of polyclonal antibodies purified from vaccinated mouse and human patient serum. RESULTS: MST analysis of fluorescently tagged mAb08 binding to cocaine reveals an approximately 15 fold decrease in its equilibrium dissociation constant in 20-50% human serum compared with that in saline buffer. A similar trend was also found using enriched polyclonal antibodies purified from vaccinated mice and patient serum, for which we have used fluorescently tagged bovine serum albumin conjugated to succinyl norcocaine (BSA-SNC. This conjugate closely mimics both cocaine and the hapten used to raise these antibodies. The ITC data also revealed that cocaine has a moderate affinity of about 2 µM to 20% human serum and very little interaction with human serum albumin or nonspecific human IgG at that concentration range. In a SPR inhibition experiment, the binding of mAb08 to immobilized BSA-SNC was inhibited by cocaine and benzoylecgonine in a highly competitive manner, whereas the purified polyclonal antibodies from vaccinated humans and mice, revealed preferential selectivity to pharmacologically active cocaine but not to the inactive metabolite benzoylecgonine. We have also developed a simple binding model to simulate the challenges associated with cocaine immunotherapy using the variable quantitative and kinetic properties of the antibodies. CONCLUSIONS: High sensitivity calorimetric determination of antibody binding to

  10. Design and construction of immune phage antibody library against Tetanus neurotoxin: Production of single chain antibody fragments.

    Science.gov (United States)

    Sadreddini, Sanam; Seifi-Najmi, Mehrnosh; Ghasemi, Babollah; Kafil, Hossein Samadi; Alinejad, Vahideh; Sadreddini, Sevil; Younesi, Vahid; Jadidi-Niaragh, Farhad; Yousefi, Mehdi

    2015-12-23

    Tetanus neurotoxin (TeNT) is composed of a light (LC) and heavy chain (HC) polypeptides, released by anaerobic bacterium Clostridium tetani and can cause fatal life-threatening infectious disease. Toxin HC and LC modules represents receptor binding and zinc metalloprotease activity, respectively. The passive administration of animal-derived antibodies against tetanus toxin has been considered as the mainstay therapy for years. However, this treatment is associated with several adverse effects due to the presence of anti-isotype antibodies. In the present study, we have produced the fully human single chain antibody fragments (HuScFv) from two human antibody phage display libraries. Twenty-four different HuscFvs were isolated from two anti TeNT immune libraries. Our produced human ScFv (HuScFv) were converted to IgG platform and analyzed regarding their specific reactivity to TeNT. All of the selected scFvs have the same VL but different VH. Three HuscFvs from the first library (TTX15, 51, 75) and two HuscFvs from the second library (TTX16, 20) were chosen to convert to IgG1 using pOptiVEC and pcDNA3.3 systems. Production of IgG1 from transfected DG44 and binding capacity of them to tetanus toxin and toxoid were measured by ELISA. ELISA results showed no detectable production of TTX16 and TTX20 IgG1. Although, TTX51 and TTX75 were converted and produced as IgG1, no reactivity to tetanus toxin and toxoid was observed. However, TTX15 was successfully produced as whole IgG1 platform with reactivity to both tetanus toxin and toxoid. The latter would be an appropriate replacement for conventional polyclonal antibodies if would meet the further characterization including specificity determination, affinity measurement and toxin neutralizing assays. Our results demonstrated production of functional IgG1 derived from TTX15 scFv and might be an appropriate replacement for polyclonal Tetabulin but it needs further characterization.

  11. LUZ-Y, a Novel Platform for the Mammalian Cell Production of Full-length IgG-bispecific Antibodies*

    Science.gov (United States)

    Wranik, Bernd J.; Christensen, Erin L.; Schaefer, Gabriele; Jackman, Janet K.; Vendel, Andrew C.; Eaton, Dan

    2012-01-01

    The ability of bispecific antibodies to simultaneously bind two unique antigens has great clinical potential. However, most approaches utilized to generate bispecific antibodies yield antibody-like structures that diverge significantly from the structure of archetype human IgG, and those that do approach structural similarity to native antibodies are often challenging to engineer and manufacture. Here, we present a novel platform for the mammalian cell production of bispecific antibodies that differ from their parental mAbs by only a single point mutation per heavy chain. Central to this platform is the addition of a leucine zipper to the C terminus of the CH3 domain of the antibody that is sufficient to drive the heterodimeric assembly of antibody heavy chains and can be readily removed post-purification. Using this approach, we developed various antibody constructs including one-armed Abs, bispecific antibodies that utilize a common light chain, and bispecific antibodies that pair light chains to their cognate heavy chains via peptide tethers. We have applied this technology to various antibody pairings and will demonstrate the engineering, purification, and biological activity of these antibodies herein. PMID:23118228

  12. Immunisation - Choice of host, adjuvants and boosting schedules with emphasis on polyclonal antibody production.

    Science.gov (United States)

    Delahaut, Philippe

    2017-03-01

    Polyclonal antibodies are frequently used as immunodiagnostic tools in fundamental research. They are also used for routine diagnostic purposes in human and veterinary medicine and for quality control procedures in the food-processing industry. The antibody is a major component of the detection system. It binds with the molecule to be identified. This conjugate is subsequently revealed by means of binding the antibody with a radio-isotope, a fluorescent substance, an enzyme inducing a color change, or a biosensor based analytical system. Polyclonal antibodies are also used for treatment purposes in various pathologies. They might have immunomodulating or anti-inflammatory properties. Snake venom, rabies and tetanus antisera are examples of a therapeutic application; immunosuppressive antithymocyte serum used in order to avoid rejection in organ transplantation is another example from human medicine. These therapeutic aids need hyperimmunisation of animals. Since these are subject to a certain number of interventions such as injections and blood samplings, animal welfare prescriptions have to be taken into account. The optimisation of the immunisation protocol allows for reducing the numbers of animals used as well as reducing stress and pain while obtaining high quality antibodies. This article describes the critical steps in polyclonal antibody production with a particular focus on the choice of the animal species, the age of the subjects, the injection protocol and the sampling times.

  13. A MONOCLONAL-ANTIBODY AGAINST HUMAN BETA-GLUCURONIDASE FOR APPLICATION IN ANTIBODY-DIRECTED ENZYME PRODRUG THERAPY

    NARCIS (Netherlands)

    Haisma, Hidde; VANMUIJEN, M; SCHEFFER, G; SCHEPER, RJ; PINEDO, HM; BOVEN, E

    1995-01-01

    The selectivity of anticancer agents may be improved by antibody-directed enzyme prodrug therapy (ADEPT), The immunogenicity of antibody-enzyme conjugates and the low tumor to normal tissue ratio calls for the use of a human enzyme and the development of a monoclonal antibody (MAb) against that enzy

  14. Preferential germline usage and VH/VL pairing observed in human antibodies selected by mRNA display.

    Science.gov (United States)

    Chen, Lei; Kutskova, Yuliya A; Hong, Feng; Memmott, John E; Zhong, Suju; Jenkinson, Megan D; Hsieh, Chung-Ming

    2015-10-01

    Since the invention of phage display, in vitro antibody display technologies have revolutionized the field of antibody discovery. In combination with antibody libraries constructed with sequences of human origin, such technologies enable accelerated therapeutic antibody discovery while bypassing the laborious animal immunization and hybridoma generation processes. Many in vitro display technologies developed since aim to differentiate from phage display by displaying full-length IgG proteins, utilizing eukaryotic translation system and codons, increasing library size or real-time kinetic selection by fluorescent activated cell sorting. We report here the development of an mRNA display technology and an accompanying HCDR3 size spectratyping monitor for human antibody discovery. Importantly, the mRNA display technology maintains a monovalent linkage between the mRNA (genotype) and display binding protein (phenotype), which minimizes avidity effect common in other display systems and allows for a stringent affinity and off-rate selection. The mRNA display technology successfully identified 100 human antibodies in 15 different selections against various targets from naïve human antibody libraries. These antibodies in general have high affinity and diversity. By analyzing the germline usage and combination of antibodies selected by the mRNA display technology, we identified trends and determined the productivity of each germline subgroup in the libraries that could serve as the knowledge base for constructing fully synthetic, next generation antibody libraries.

  15. Broad epitope coverage of a human in vitro antibody library

    Science.gov (United States)

    Sivasubramanian, Arvind; Lynaugh, Heather; Yu, Yao; Miles, Adam; Eckman, Josh; Schutz, Kevin; Piffath, Crystal; Boland, Nadthakarn; Durand, Stéphanie; Boland, Todd; Vásquez, Maximiliano; Xu, Yingda; Abdiche, Yasmina

    2017-01-01

    ABSTRACT Successful discovery of therapeutic antibodies hinges on the identification of appropriate affinity binders targeting a diversity of molecular epitopes presented by the antigen. Antibody campaigns that yield such broad “epitope coverage” increase the likelihood of identifying candidates with the desired biological functions. Accordingly, epitope binning assays are employed in the early discovery stages to partition antibodies into epitope families or “bins” and prioritize leads for further characterization and optimization. The collaborative program described here, which used hen egg white lysozyme (HEL) as a model antigen, combined 3 key capabilities: 1) access to a diverse panel of antibodies selected from a human in vitro antibody library; 2) application of state-of-the-art high-throughput epitope binning; and 3) analysis and interpretation of the epitope binning data with reference to an exhaustive set of published antibody:HEL co-crystal structures. Binning experiments on a large merged panel of antibodies containing clones from the library and the literature revealed that the inferred epitopes for the library clones overlapped with, and extended beyond, the known structural epitopes. Our analysis revealed that nearly the entire solvent-exposed surface of HEL is antigenic, as has been proposed for protein antigens in general. The data further demonstrated that synthetic antibody repertoires provide as wide epitope coverage as those obtained from animal immunizations. The work highlights molecular insights contributed by increasingly higher-throughput binning methods and their broad utility to guide the discovery of therapeutic antibodies representing a diverse set of functional epitopes. PMID:27748644

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

    Science.gov (United States)

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

    2016-04-22

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

  17. Production and characterization of antibodies to advanced glycation products on proteins.

    Science.gov (United States)

    Nakayama, H; Taneda, S; Kuwajima, S; Aoki, S; Kuroda, Y; Misawa, K; Nakagawa, S

    1989-07-31

    Antibodies directed against advanced glycation products formed during Maillard reaction have been generated and characterized. These antibodies reacted specifically with advanced glycation products in common among proteins incubated with glucose, but not early-stage compounds such as a Schiff base adduct and Amadori rearrangement products. Incubation of bovine serum albumin with glucose caused a time-related increase in immunoreactivity and a concomitant increase in fluorescence intensity. These antibodies may serve as a useful tool to elucidate pathophysiological roles of advanced Maillard reaction in diabetic complications and aging processes.

  18. Expression of secreted human single-chain fragment variable antibody against human amyloid beta peptide in Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    Jiong Cai; Fang Li; Shizhen Wang

    2008-01-01

    BACKGROUND: Studies have shown that monoclonal or polyclonal antibody injections ofamyloid β peptide arc effective in removing amyloid β peptide overload in the brain.OBJECTIVE: Based on successful screening of a human single-chain fragment variable antibody specific to amyloid β peptide, this paper aimed to express recombinant human single-chain variable antibody against amyloid β peptide.DESIGN, TIME AND SETTING: A single sample experiment was performed at the Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Hospital (Beijing, China) from January to July 2006.MATERIALS: Human single-chain fragment variable antibody gene against amyloid β peptide was screened from a human phage-display antibody library.METHODS: Human single-chain fragment variable antibody gene was mutated to eliminate a BamHI restriction site and cloned into a Teasy plasmid for pT-seFvAβ construction, which was identified by PCR amplification and endonuclease digestion. Plasmid pT-scFvA β was cut by EcoRl and Notl endonucleases, and the antibody gene was cloned into pPIC9K plasmid to construct pPIC9K-scFvA β expression vector, which was confirmed by gene sequencing. Linearized pPICgK-scFvA β was used to transform a Pichia pastoris GS115 cell line, and the recombinant was induced by 0.5 % methanol to express human single-chain fragment variable antibody specific to amyloid β peptide.MAIN OUTCOME MEASURES: Protein electrophoresis was used to identify PCR products, gene sequencing was uscd to verify the pPIC9K-scFvA sequence, and SDS-PAGE was used to detect recombinant expression of human single-chain fragment variable antibody specific to amyloid β peptide in Pichia pastoris.RESULTS: Gene sequencing confirmed pPICgK-scFvA β orientation. Rccomhinants were obtained by lineadzed pPIC9K-scFvA β transformation. After induction with 0.5% methanol, the recombinant yeast cells secreted proteins of 33-ku size

  19. Human cysticercosis: antigens, antibodies and non-responders.

    Science.gov (United States)

    Flisser, A; Woodhouse, E; Larralde, C

    1980-01-01

    Immunoelectrophoresis of sera from patients with brain cysticercosis against a crude antigenic extract from Cysticercus cellulosae indicates that nearly 50% of the patients do not make sufficient antibodies to ostensively precipitate. The other 50% of the patients who do make precipitating antibodies show a very heterogeneous response in the number of antigens they recognize as well as in the type of antigen--as classified by their electrophoretic mobilities. The most favoured, called antigen B, is recognized by 84% of positive sera and corresponds to one or a limited number of antigens isoelectric at pH 8.6. Indirect immunofluorescence with monospecific anti-human immunoglobulins, performed upon the immunoelectrophoretic preparations, reveal that all cysticercus antigens induced the synthesis of antibodies in the immunoglobulin classes in the order G greater than M greater than E greater than A greater than D. Finally, antigen H (an anodic component) seems to favour IgE relative to its ability to induce IgG. Thus, although in natural infection a good proportion of cysticercotic patients do not seem to mount an energetic antibody response against the parasite, giving rise to some speculations about immunosuppression, the fact that 50% do synthesize antibodies allows for some optimistic expectations from vaccination of humans--in view of the good results of vaccination in experimental animals mediated by IgG antibodies. A likely prospect for a human vaccine would be antigen B because it is the most frequently detected by humans, although its immunizing and toxic properties remain to be properly studied. Images FIG. 1 FIG. 3 FIG. 6 PMID:7389197

  20. Production and characterisation of a neutralising chimeric antibody against botulinum neurotoxin A.

    Directory of Open Access Journals (Sweden)

    Julie Prigent

    Full Text Available Botulinum neurotoxins, produced by Clostridium botulinum bacteria, are the causative agent of botulism. This disease only affects a few hundred people each year, thus ranking it among the orphan diseases. However, botulinum toxin type A (BoNT/A is the most potent toxin known to man. Due to their potency and ease of production, these toxins were classified by the Centers for Disease Control and Prevention (CDC as Category A biothreat agents. For several biothreat agents, like BoNT/A, passive immunotherapy remains the only possible effective treatment allowing in vivo neutralization, despite possible major side effects. Recently, several mouse monoclonal antibodies directed against a recombinant fragment of BoNT/A were produced in our laboratory and most efficiently neutralised the neurotoxin. In the present work, the most powerful one, TA12, was selected for chimerisation. The variable regions of this antibody were thus cloned and fused with the constant counterparts of human IgG1 (kappa light and gamma 1 heavy chains. Chimeric antibody production was evaluated in mammalian myeloma cells (SP2/0-Ag14 and insect cells (Sf9. After purifying the recombinant antibody by affinity chromatography, the biochemical properties of chimeric and mouse antibody were compared. Both have the same very low affinity constant (close to 10 pM and the chimeric antibody exhibited a similar capacity to its parent counterpart in neutralising the toxin in vivo. Its strong affinity and high neutralising potency make this chimeric antibody interesting for immunotherapy treatment in humans in cases of poisoning, particularly as there is a probable limitation of the immunological side effects observed with classical polyclonal antisera from heterologous species.

  1. Engineering humanized antibody framework sequences for optimal site-specific conjugation of cytotoxins.

    Science.gov (United States)

    Spidel, Jared L; Albone, Earl F; Cheng, Xin; Vaessen, Benjamin; Jacob, Sara; Milinichik, Andrew Z; Verdi, Arielle; Kline, J Bradford; Grasso, Luigi

    The prevailing techniques used to generate antibody-drug conjugates (ADCs) involve random conjugation of the linker-drug to multiple lysines or cysteines in the antibody. Engineering natural and non-natural amino acids into an antibody has been demonstrated to be an effective strategy to produce homogeneous ADC products with defined drug-to-antibody ratios. We recently reported an efficient residue-specific conjugation technology (RESPECT) where thiol-reactive payloads can be efficiently conjugated to a native unpaired cysteine in position 80 (C80) of rabbit light chains. Deimmunizing the rabbit variable domains through humanization is necessary to reduce the risk of anti-drug antibody responses in patients. However, we found that first-generation humanized RESPECT ADCs showed high levels of aggregation and low conjugation efficiency. We correlated these negative properties to the phenylalanine at position 83 present in most human variable kappa frameworks. When position 83 was substituted with selected amino acids, conjugation was restored and aggregation was reduced to levels similar to the chimeric ADC. This engineering strategy allows for development of second-generation humanized RESPECT ADCs with desirable biopharmaceutical properties.

  2. Production of antibodies with peptide-CpG-DNA-liposome complex without carriers

    Directory of Open Access Journals (Sweden)

    Kim Doo-Sik

    2011-05-01

    Full Text Available Abstract Background The screening of peptide-based epitopes has been studied extensively for the purpose of developing therapeutic antibodies and prophylactic vaccines that can be potentially useful for treating cancer and infectious diseases such as influenza virus, malaria, hepatitis B, and HIV. To improve the efficacy of antibody production by epitope-based immunization, researchers evaluated liposomes as a means of delivering vaccines; they also formulated adjuvants such as flagella and CpG-DNA to enhance the magnitude of immune responses. Here, we provide a potent method for peptide-based epitope screening and antibody production without conventional carriers. Results We present that a particular form of natural phosphodiester bond CpG-DNA encapsulated in a specific liposome complex (Lipoplex(O induces potent immunomodulatory activity in humans as well as in mice. Additionally, Lipoplex(O enhances the production of IgG2a specific to antigenic protein in mice. Most importantly, immunization of mice with several peptides co-encapsulated with Lipoplex(O without carriers significantly induces each peptide-specific IgG2a production in a TLR9-dependent manner. A peptide-specific monoclonal antibody produced against hepatocellular carcinoma-associated antigen has functional effects on the cancer cells. Conclusions Our overall results show that Lipoplex(O is a potent adjuvant and that complexes of peptide and Lipoplex(O are extremely useful for B cell epitope screening and antibody production without carriers. Therefore, our strategy may be promptly used for the development of therapeutic antibodies by rapid screening of potent B cell epitopes.

  3. Analysis of Antibodies Directed against Merozoite Surface Protein 1 of the Human Malaria Parasite Plasmodium falciparum

    Science.gov (United States)

    Woehlbier, Ute; Epp, Christian; Kauth, Christian W.; Lutz, Rolf; Long, Carole A.; Coulibaly, Boubacar; Kouyaté, Bocar; Arevalo-Herrera, Myriam; Herrera, Sócrates; Bujard, Hermann

    2006-01-01

    The 190-kDa merozoite surface protein 1 (MSP-1) of Plasmodium falciparum, an essential component in the parasite's life cycle, is a primary candidate for a malaria vaccine. Rabbit antibodies elicited by the heterologously produced MSP-1 processing products p83, p30, p38, and p42, derived from strain 3D7, were analyzed for the potential to inhibit in vitro erythrocyte invasion by the parasite and parasite growth. Our data show that (i) epitopes recognized by antibodies, which inhibit parasite replication, are distributed throughout the entire MSP-1 molecule; (ii) when combined, antibodies specific for different regions of MSP-1 inhibit in a strictly additive manner; (iii) anti-MSP-1 antibodies interfere with erythrocyte invasion as well as with the intraerythrocytic growth of the parasite; and (iv) antibodies raised against MSP-1 of strain 3D7 strongly cross-inhibit replication of the heterologous strain FCB-1. Accordingly, anti-MSP-1 antibodies appear to be capable of interfering with parasite multiplication at more than one level. Since the overall immunogenicity profile of MSP-1 in rabbits closely resembles that found in sera of Aotus monkeys immunized with parasite-derived MSP-1 and of humans semi-immune to malaria from whom highly inhibiting antigen-specific antibodies were recovered, we consider the findings reported here to be relevant for the development of MSP-1-based vaccines against malaria. PMID:16428781

  4. Therapeutic monoclonal antibodies in human breast milk: a case study.

    Science.gov (United States)

    Ross, Elle; Robinson, Steven E; Amato, Carol; McMillan, Colette; Westcott, Jay; Wolf, Tiffany; Robinson, William A

    2014-04-01

    Recently, therapeutic monoclonal antibodies have been introduced for the treatment of advanced melanoma and other diseases. It remains unclear whether these drugs can be safely administered to women who are breast feeding because of the potential hazardous side effects for nursing infants. One such therapy for metastatic melanoma is ipilimumab, a human monoclonal antibody that blocks cytotoxic T-lymphocyte-antigen-4, and is the preferred treatment for patients with metastatic melanoma when other molecular therapies are not viable. This study measured ipilimumab levels in the breast milk of a patient undergoing treatment that were enough to raise concerns for a nursing infant exposed to ipilimumab.

  5. [Production and characteristics of monoclonal antibodies to the diphtheria toxin].

    Science.gov (United States)

    Valiakina, T I; Lakhtina, O E; Komaleva, R L; Simonova, M A; Samokhvalova, L V; Shoshina, N S; Kalinina, N A; Rubina, A Iu; Filippova, M A; Vertiev, Iu V; Grishin, E V

    2009-01-01

    Monoclonal antibodies to the diphtheria toxin were produced without cross reactivity with the thermolabile toxin (LT) from Escherichia coli; ricin; choleraic toxin; the SeA, SeB, SeE, SeI, and SeG toxins of staphylococcus; the lethal factor of the anthrax toxin; and the protective antigen of the anthrax toxin. A pair of antibodies for the quantitative determination of the diphtheria toxin in the sandwich variation of enzyme-linked immunosorbent assay (ELISA) was chosen. The determination limit of the toxin was 0.7 ng/ml in plate and 1.6 ng/ml in microchip ELISA. The presence of a secretion from the nasopharynx lavage did not decrease the sensitivity of the toxin determination by sandwich ELISA. The immunization of mice with the diphtheria toxin and with a conjugate of the diphtheria toxin with polystyrene microspheres demonstrated that the conjugate immunization resulted in the formation of hybridoma clones which produced antibodies only to the epitopes of the A fragment of the diphtheria toxin. The immunization with the native toxin caused the production of hybridoma clones which predominantly produced antibodies to the epitopes of the B fragment.

  6. Production and purification of polyclonal antibody against melatonin hormone

    Directory of Open Access Journals (Sweden)

    Fooladsaz K

    1999-09-01

    Full Text Available Nowadays immunochemical techniques have played a very important and valuable role in quantitative and qualitative assays of liquid compounds of the body. Producing antibody against immunogenes is the first step to make immunochemical kits. In this study production and purification of polyclonal antibody against melatonin has been considered. This hormone which has several important functions in physiological conditions such as migraine, cirrhosis, mammary gland cancer and other diseases, is the most important pineal gland secretion. This gland is a circumventricular organ of brain and according to histological and anatomical studies, it is a high secretory organ, that secretes active biological substances like melatonin, oxytocin, serotonin and ect. In this study, melatonin has been considered as hapten and has become an immunogen by being linked to the bovine serum Albumin. Then, by the immunization of three white New Zeland rabbits that had the booster injections in regular intervals, the antibody titer was detected to be 1/2000, by using checkboard curves, and with the use of melatonin linked to penicillinase as a labeled antigen, the titer was detected 1/200. Finally an antibody with high purification rate has been obtained, which can be used in immunochemical assays like RIA, ELISA, and EIA.

  7. Generation and Characterization of Specific Antibodies to the Murine and Human Ectonucleotidase NTPDase8.

    Science.gov (United States)

    Pelletier, Julie; Salem, Mabrouka; Lecka, Joanna; Fausther, Michel; Bigonnesse, François; Sévigny, Jean

    2017-01-01

    The ectonucleotidase nucleoside triphosphate diphosphohydrolase-8 (NTPDase8) is the last member of the Ecto-NTPDase family to be discovered and characterized. It is a transmembrane protein which regulates the concentration of the agonists of P1 and P2 receptors at the cell surface. The functions of the enzyme are still not known partly due to the lack of specific tools such as antibodies. In this work, guinea pig polyclonal antibodies against mouse NTPDase8 and mouse monoclonal antibodies against human NTPDase8 have been generated and characterized. For the production of antibodies against mouse NTPDase8 several techniques have been tried. Several peptide antigens in several hosts (rabbit, rat, hamster, and guinea pig) failed to give a positive reaction suggesting that NTPDase8 is poorly immunogenic. In this study, we describe the successful process that led to anti-mouse NTPDase8, namely the cDNA immunization technique. Monoclonal antibodies to human NTPDase8 were also obtained by cDNA immunization followed by a final injection with transfected human embryonic kidney (HEK 293T) cells expressing human NTPDase8. The specificity of these antibodies was evaluated by Western blot, immunocytochemistry, immunohistochemistry and flow cytometry. In contrast, all commercial antibodies to NTPDase8 peptides that we have tested failed to give a specific positive signal against the expressed NTPDase8 protein when used to probe Western blots. In addition, immunohistochemistry experiments confirmed the presence of NTPDase8 in mouse liver canaliculi. The tools generated in this work will help characterize NTPDase8 localization and function in future studies and its contribution to the modulation of P1 and P2 receptor activation.

  8. Generation and applications of monoclonal antibodies for livestock production.

    Science.gov (United States)

    Van Der Lende, T

    1994-01-01

    Monoclonal antibodies (MCAs) have found widespread applications in livestock production. Although the generation of murine MCAs is at present a routine, the production of homologous MCAs, especially important for in vivo applications, is still hampered by the lack of efficient homologous fusion partners for immortalization of antibody producing lymphocytes of livestock species. At present, MCAs are used in immunodiagnostic tests e.g. to monitor livestock reproduction and quality of livestock products. In the future MCAs will also be used in immunosensors for real-time and on-site applications in the same areas. The commercial application of MCAs for the immunomodulation of (pharmacologically induced) physiological processes underlying important (re)production traits is at present limited to the use of anti-PMSG MCAs in PMSG-induced superovulation. However, many potentially interesting applications are under investigation (e.g. immunopotentiation of growth hormone to enhance growth; immunocytolysis of adipocytes to increase lean meat production; immunoneutralization of GnRH for immunocastration; immunoimitation of hormone activity with anti-idiotype antibodies). Attempts to use specific MCAs for the sexing of embryos have been disappointing, mainly because of the relatively low accuracy. In the future, MCAs against membrane proteins which are specific for X- or Y-chromosome bearing spermatozoa might be used for bulk separation of livestock sperm. In general, it is expected that engineered (homologous) recombinant MCAs will largely contribute to the development of a new generation of rapid immunodiagnostic tests and effective immunomodulation applications. They will further increase the use of MCAs in livestock production.

  9. Characterization of golimumab, a human monoclonal antibody specific for human tumor necrosis factor α.

    Science.gov (United States)

    Shealy, David J; Cai, Ann; Staquet, Kim; Baker, Audrey; Lacy, Eilyn R; Johns, Laura; Vafa, Omid; Gunn, George; Tam, Susan; Sague, Sarah; Wang, Dana; Brigham-Burke, Mike; Dalmonte, Paul; Emmell, Eva; Pikounis, Bill; Bugelski, Peter J; Zhou, Honghui; Scallon, Bernard J; Giles-Komar, Jill

    2010-01-01

    We prepared and characterized golimumab (CNTO148), a human IgG1 tumor necrosis factor alpha (TNFα) antagonist monoclonal antibody chosen for clinical development based on its molecular properties. Golimumab was compared with infliximab, adalimumab and etanercept for affinity and in vitro TNFα neutralization. The affinity of golimumab for soluble human TNFα, as determined by surface plasmon resonance, was similar to that of etanercept (18 pM versus 11 pM), greater than that of infliximab (44 pM) and significantly greater than that of adalimumab (127 pM, p=0.018).  The concentration of golimumab necessary to neutralize TNFα-induced E-selectin expression on human endothelial cells by 50% was significantly less than those for infliximab (3.2 fold; p=0.017) and adalimumab (3.3-fold; p=0.008) and comparable to that for etanercept. The conformational stability of golimumab was greater than that of infliximab (primary melting temperature [Tm] 74.8 °C vs. 69.5 °C) as assessed by differential scanning calorimetry.  In addition, golimumab showed minimal aggregation over the intended shelf life when formulated as a high concentration liquid product (100 mg/mL) for subcutaneous administration.  In vivo, golimumab at doses of 1 and 10 mg/kg significantly delayed disease progression in a mouse model of human TNFα-induced arthritis when compared with untreated mice, while infliximab was effective only at 10 mg/kg. Golimumab also significantly reduced histological scores for arthritis severity and cartilage damage, as well as serum levels of pro-inflammatory cytokines and chemokines associated with arthritis. Thus, we have demonstrated that golimumab is a highly stable human monoclonal antibody with high affinity and capacity to neutralize human TNFα in vitro and in vivo.

  10. An Insertion Mutation That Distorts Antibody Binding Site Architecture Enhances Function of a Human Antibody

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Jens C.; Ekiert, Damian C.; Tumpey, Terrence M.; Smith, Patricia B.; Wilson, Ian A.; Crowe, Jr., James E. (Vanderbilt); (Scripps); (CDC)

    2011-09-02

    The structural and functional significance of somatic insertions and deletions in antibody chains is unclear. Here, we demonstrate that a naturally occurring three-amino-acid insertion within the influenza virus-specific human monoclonal antibody 2D1 heavy-chain variable region reconfigures the antibody-combining site and contributes to its high potency against the 1918 and 2009 pandemic H1N1 influenza viruses. The insertion arose through a series of events, including a somatic point mutation in a predicted hot-spot motif, introduction of a new hot-spot motif, a molecular duplication due to polymerase slippage, a deletion due to misalignment, and additional somatic point mutations. Atomic resolution structures of the wild-type antibody and a variant in which the insertion was removed revealed that the three-amino-acid insertion near the base of heavy-chain complementarity-determining region (CDR) H2 resulted in a bulge in that loop. This enlarged CDR H2 loop impinges on adjacent regions, causing distortion of the CDR H1 architecture and its displacement away from the antigen-combining site. Removal of the insertion restores the canonical structure of CDR H1 and CDR H2, but binding, neutralization activity, and in vivo activity were reduced markedly because of steric conflict of CDR H1 with the hemagglutinin antigen.

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

    Science.gov (United States)

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

    2014-01-01

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

  12. A Cassette Vector System for the Rapid Cloning and Production of Bispecific Tetravalent Antibodies

    Directory of Open Access Journals (Sweden)

    Stefanie Claudia Pohl

    2012-04-01

    Full Text Available Bivalent single chain (scFv-Fc antibodies have been used for years as recombinant alternatives of natural immunoglobulins. We have extended this approach to the scFv-Fc-scFv antibody format to obtain tetravalent antigen binding and the possibility to generate bispecific antibodies. We developed a mammalian expression vector system to construct tetravalent scFv-Fc-scFv antibodies with two NcoI+NotI compatible cloning sites flanking the Fc gene fragment. We demonstrated direct cloning from single chain antibody gene libraries and tested various scFv combinations. Transient production of scFv-Fc-scFv antibodies in human embryonic kidney (HEK 293T cells achieved volumetric yields of up to 10 mg/L. However, expression levels were strongly dependent on the carboxyterminal scFv and the scFv combination. All scFv-Fc-scFv antibodies exclusively formed disulfide-linked homodimers. Antigen binding studies revealed dual specificity for all scFv-Fc-scFv employing different scFv fragments. Comparison of C-reactive protein (CRP specific monovalent scFv LA13-IIE3, bivalent scFv-Fc and Fc-scFv LA13-IIE3, and tetravalent scFv-Fc-scFv (scFv LA13-IIE3 in combination with scFvs LA13-IIE3, TOB4-B11, or TOB5-D4 revealed an up to 500-fold increased antigen binding. This novel scFv-Fc-scFv antibody expression system allows simple and fast testing of various scFv combinations.

  13. The human antibody response to the surface of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Casey C Perley

    Full Text Available Vaccine-induced human antibodies to surface components of Haemophilus influenzae and Streptococcus pneumonia are correlated with protection. Monoclonal antibodies to surface components of Mycobacterium tuberculosis are also protective in animal models. We have characterized human antibodies that bind to the surface of live M. tuberculosis.Plasma from humans with latent tuberculosis (TB infection (n = 23, active TB disease (n = 40, and uninfected controls (n = 9 were assayed by ELISA for reactivity to the live M. tuberculosis surface and to inactivated M. tuberculosis fractions (whole cell lysate, lipoarabinomannan, cell wall, and secreted proteins.When compared to uninfected controls, patients with active TB disease had higher antibody titers to the surface of live M. tuberculosis (Δ = 0.72 log10, whole cell lysate (Δ = 0.82 log10, and secreted proteins (Δ = 0.62 log10, though there was substantial overlap between the two groups. Individuals with active disease had higher relative IgG avidity (Δ = 1.4 to 2.6 to all inactivated fractions. Surprisingly, the relative IgG avidity to the live M. tuberculosis surface was lower in the active disease group than in uninfected controls (Δ =  -1.53, p = 0.004. Patients with active disease had higher IgG than IgM titers for all inactivated fractions (ratios, 2.8 to 10.1, but equal IgG and IgM titers to the live M. tuberculosis surface (ratio, 1.1. Higher antibody titers to the M. tuberculosis surface were observed in active disease patients who were BCG-vaccinated (Δ = 0.55 log10, p = 0.008, foreign-born (Δ = 0.61 log10, p = 0.004, or HIV-seronegative (Δ = 0.60 log10, p = 0.04. Higher relative IgG avidity scores to the M. tuberculosis surface were also observed in active disease patients who were BCG-vaccinated (Δ = 1.12, p < 0.001 and foreign-born (Δ = 0.87, p = 0.01.Humans with active TB disease produce antibodies to the surface of M. tuberculosis with low avidity and with a low IgG/IgM ratio

  14. The Human Antibody Response to the Surface of Mycobacterium tuberculosis

    Science.gov (United States)

    Perley, Casey C.; Frahm, Marc; Click, Eva M.; Dobos, Karen M.; Ferrari, Guido; Stout, Jason E.; Frothingham, Richard

    2014-01-01

    Background Vaccine-induced human antibodies to surface components of Haemophilus influenzae and Streptococcus pneumonia are correlated with protection. Monoclonal antibodies to surface components of Mycobacterium tuberculosis are also protective in animal models. We have characterized human antibodies that bind to the surface of live M. tuberculosis. Methods Plasma from humans with latent tuberculosis (TB) infection (n = 23), active TB disease (n = 40), and uninfected controls (n = 9) were assayed by ELISA for reactivity to the live M. tuberculosis surface and to inactivated M. tuberculosis fractions (whole cell lysate, lipoarabinomannan, cell wall, and secreted proteins). Results When compared to uninfected controls, patients with active TB disease had higher antibody titers to the surface of live M. tuberculosis (Δ = 0.72 log10), whole cell lysate (Δ = 0.82 log10), and secreted proteins (Δ = 0.62 log10), though there was substantial overlap between the two groups. Individuals with active disease had higher relative IgG avidity (Δ = 1.4 to 2.6) to all inactivated fractions. Surprisingly, the relative IgG avidity to the live M. tuberculosis surface was lower in the active disease group than in uninfected controls (Δ = –1.53, p = 0.004). Patients with active disease had higher IgG than IgM titers for all inactivated fractions (ratios, 2.8 to 10.1), but equal IgG and IgM titers to the live M. tuberculosis surface (ratio, 1.1). Higher antibody titers to the M. tuberculosis surface were observed in active disease patients who were BCG-vaccinated (Δ = 0.55 log10, p = 0.008), foreign-born (Δ = 0.61 log10, p = 0.004), or HIV-seronegative (Δ = 0.60 log10, p = 0.04). Higher relative IgG avidity scores to the M. tuberculosis surface were also observed in active disease patients who were BCG-vaccinated (Δ = 1.12, p<0.001) and foreign-born (Δ = 0.87, p = 0.01). Conclusions/Significance Humans

  15. Phase I study of anticolon cancer humanized antibody A33.

    Science.gov (United States)

    Welt, Sydney; Ritter, Gerd; Williams, Clarence; Cohen, Leonard S; John, Mary; Jungbluth, Achim; Richards, Elizabeth A; Old, Lloyd J; Kemeny, Nancy E

    2003-04-01

    Humanized A33 (huA33; IgG1) monoclonal antibody detects a determinant expressed by 95% of colorectal cancers and can activate immune cytolytic mechanisms. The present study was designed to (a) define the toxicities and maximum tolerated dose of huA33 and (b) determine huA33 immunogenicity. Patients (n = 11) with advanced chemotherapy-resistant colorectal cancer received 4-week cycles of huA33 at 10, 25, or 50 mg/m(2)/week. Serum samples were analyzed using biosensor technology for evidence of human antihuman antibody (HAHA) response. Eight of 11 patients developed a HAHA response. Significant toxicity was limited to four patients who developed high HAHA titers. In two of these cases, infusion-related reactions such as fevers, rigors, facial flushing, and changes in blood pressure were observed, whereas in the other two cases, toxicity consisted of skin rash, fever, or myalgia. Of three patients who remained HAHA negative, one achieved a radiographic partial response, with reduction of serum carcinoembryonic antigen from 80 to 3 ng/ml. Four patients had radiographic evidence of stable disease (2, 4, 6, and 12 months), with significant reductions (>25%) in serum carcinoembryonic antigen levels in two cases. The complementarity-determining region-grafted huA33 antibody is immunogenic in the majority of colon cancer patients (73%). HAHA activity can be measured reproducibly and quantitatively by BIACORE analysis. Whereas the huA33 construct tested here may be too immunogenic for further clinical development, the antitumor effects observed in the absence of antibody-mediated toxicity and in this heavily pretreated patient population warrant clinical testing of other IgG1 humanized versions of A33 antibody.

  16. Recognition determinants of broadly neutralizing human antibodies against dengue viruses.

    Science.gov (United States)

    Rouvinski, Alexander; Guardado-Calvo, Pablo; Barba-Spaeth, Giovanna; Duquerroy, Stéphane; Vaney, Marie-Christine; Kikuti, Carlos M; Navarro Sanchez, M Erika; Dejnirattisai, Wanwisa; Wongwiwat, Wiyada; Haouz, Ahmed; Girard-Blanc, Christine; Petres, Stéphane; Shepard, William E; Desprès, Philippe; Arenzana-Seisdedos, Fernando; Dussart, Philippe; Mongkolsapaya, Juthathip; Screaton, Gavin R; Rey, Félix A

    2015-04-02

    Dengue disease is caused by four different flavivirus serotypes, which infect 390 million people yearly with 25% symptomatic cases and for which no licensed vaccine is available. Recent phase III vaccine trials showed partial protection, and in particular no protection for dengue virus serotype 2 (refs 3, 4). Structural studies so far have characterized only epitopes recognized by serotype-specific human antibodies. We recently isolated human antibodies potently neutralizing all four dengue virus serotypes. Here we describe the X-ray structures of four of these broadly neutralizing antibodies in complex with the envelope glycoprotein E from dengue virus serotype 2, revealing that the recognition determinants are at a serotype-invariant site at the E-dimer interface, including the exposed main chain of the E fusion loop and the two conserved glycan chains. This 'E-dimer-dependent epitope' is also the binding site for the viral glycoprotein prM during virus maturation in the secretory pathway of the infected cell, explaining its conservation across serotypes and highlighting an Achilles' heel of the virus with respect to antibody neutralization. These findings will be instrumental for devising novel immunogens to protect simultaneously against all four serotypes of dengue virus.

  17. Antibody

    Science.gov (United States)

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

  18. Studies of neutralising antibodies to SV40 in human sera.

    Science.gov (United States)

    Minor, P; Pipkin, P; Jarzebek, Z; Knowles, W

    2003-07-01

    It has been suggested that the low levels of antibody to the simian polyoma virus SV40 found in human sera may be linked to the use of polio vaccines. Panels of sera from areas of the world with different vaccination histories were examined to see if consistent differences could be identified. In a total of 2,054 sera from the United Kingdom, 692 from Africa and 923 from Poland taken between 1985 and 1997, the seroprevalence was generally between 3 and 5%, although exceptionally one collection from Morocco had a prevalence of 100%, and one from Poland of 0.4%. The seroprevalence showed no obvious age-dependent increase and titres were low compared to post infection animal sera. The results are consistent with previous studies and reveal no general geographically based differences related to possible differences in vaccination history, but the origin of the SV40 antibody in human sera remains to be established.

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

    Science.gov (United States)

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

    2013-01-01

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

  20. Discovery Of Human Antibodies Against Spitting Cobra Toxins

    DEFF Research Database (Denmark)

    Bojsen-Møller, Laura; Lohse, Brian; Harrison, Robert

    spitting cobras are among the most medically important snakes in sub-Saharan regions due to the severity of the clinical outcomes caused by their cytotoxic venom, which is derived from cytotoxins of the 3FTx toxin family and PLA2. Here we report the results of our progress in identifying human antibodies...... targeting relevant toxins from the venom of the black necked spitting cobra (Naja nigricolis)....

  1. Human C-C chemokine receptor 3 monoclonal antibody inhibits pulmonary inflammation in allergic mice

    Institute of Scientific and Technical Information of China (English)

    Kai WANG; Hua-hao SHEN; Wen LI; Hua-qiong HUANG

    2007-01-01

    Aim:To evaluate the effect of C-C chemokine receptor 3 (CCR3) blockade on pulmonary inflammation and mucus production in allergic mice. Methods:We used the synthetic peptide of the CCR3 NH2-terminal as the immunizing antigen and generated murine monoclonal antibody against the human CCR3. In addition,the generated antibody was administered to mice sensitized and challenged with ovalbumin. The inflammatory cells in bronchoalveolar lavage,cytokine levels,pulmonary histopathology,and mucus secretion were examined. Results:The Western blotting analysis indicated that the generated antibody bound to CCR3 specifically. The allergic mice treated with the antihuman CCR3 antibody exhibited a significant reduction of pulmonary inflammation accompanied with the alteration of cytokine. Conclusion:The antibody we generated was specific to CCR3. The inhibition of airway inflammation and mucus overproduction by the antibody suggested that the blockade of CCR3 is an appealing therapeutical target for asthma. The present research may provide an experimental basis for the further study of this agent.

  2. The Use of Monoclonal Antibodies in Human Prion Disease

    Science.gov (United States)

    Bodemer, Walter

    Detection of PrP and its pathological isoform(s) is the key to understanding the etiology and pathogenesis of transmissible spongiform encephalopathy. There is ample evidence that PrP isoforms constitute a major component of an unknown and perhaps unconventional infectious agent. An etiological relationship between human and zoonotic transmissible spongiform encephalopathies may be revealed with monoclonal antibodies. Knowledge of the conformational transition rendering a nonpathogenic, almost ubiquitous cellular protein into a pathogenic one is crucial to defining pathomechanisms. The stepwise or even continuous formation of pathogenic molecules can be monitored. Any improvement in the early diagnosis could help to conceive new therapeutic measures which are not currently available. Determination of PrP isoforms in tissue, cells, or body fluids may be of prognostic value. Many experimental approaches in molecular medicine and molecular biology of the prion protein already rely on monoclonal antibodies. Recombinant antibodies such as the single-chain Fv may soon replace traditional hybridoma techniques. Binding affinity can easily be manipulated by a number of techniques, including in vitro mutagenesis - a step which could never be carried out using the traditional hybridoma technology. Monoclonal antibodies are and will remain an essential support for ongoing research on the prion protein in general and on the unconventional infectious prions.

  3. Generation and Characterization of Novel Human IRAS Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2009-01-01

    Full Text Available Imidazoline receptors were first proposed by Bousquet et al., when they studied antihypertensive effect of clonidine. A strong candidate for I1R, known as imidazoline receptor antisera-selected protein (IRAS, has been cloned from human hippocampus. We reported that IRAS mediated agmatine-induced inhibition of opioid dependence in morphine-dependent cells. To elucidate the functional and structure properties of I1R, we developed the newly monoclonal antibody against the N-terminal hIRAS region including the PX domain (10–120aa through immunization of BALB/c mice with the NusA-IRAS fusion protein containing an IRAS N-terminal (10–120aa. Stable hybridoma cell lines were established and monoclonal antibodies specifically recognized full-length IRAS proteins in their native state by immunoblotting and immunoprecipitation. Monoclonal antibodies stained in a predominantly punctate cytoplasmic pattern when applied to IRAS-transfected HEK293 cells by indirect immunofluorescence assays and demonstrated excellent reactivity in flow immunocytometry. These monoclonal antibodies will provide powerful reagents for the further investigation of hIRAS protein functions.

  4. Inhibiting angiogenesis with human single-chain variable fragment antibody targeting VEGF.

    Science.gov (United States)

    Hosseini, Hossien; Rajabibazl, Masoumeh; Ebrahimizadeh, Walead; Dehbidi, Gholamreza Rafiei

    2015-01-01

    Vascular endothelial growth factor (VEGF) is a highly specific angiogenesis factor which has crucial roles in the angiogenesis of tumors. Anti-angiogenesis agents can inhibit growth and metastasis of tumor cells. Single-chain variable fragments (scFv) have the same affinity as whole antibodies and smaller size, thus result in more tissue permeability and higher production yield. In this research we aim to isolate a human scFv antibody against VEGF that inhibits angiogenesis. For that, we have used human scFv phage library to isolate a specific scFv antibody against binding site of VEGF. The human scFv phage library was amplified according to the manufacture protocol and panned against recombinant VEGF. ScFv antibody was isolated after five rounds of panning. Phage ELISA was used for detection of the highest affinity binder (HR6). Soluble HR6 scFv was expressed in non-suppressor strain of Escherichia coli HB2151 and purified using Ni-NTA chromatography. In vivo and in vitro function of the HR6 scFv was analyzed by chorioallantoic membrane assay and endothelial cell proliferation assay on VEGF stimulated HUVECs. Result of the cross reactivity showed that HR6 scFv specifically bounds to VEGF. The affinity was calculated to be 1.8×10(-7)M. HR6 could stop HUVEC proliferation in a dose dependent manner and anti-angiogenesis activity was observed using 10μg of HR6 in chorioallantoic membrane assay. In this work, we demonstrate that a HR6 scFv selected from human library phage display specifically blocks VEGF signaling, furthermore, this scFv has an anti-angiogenesis effect and because of its small size has more tissue diffusion. The HR6 antibody was isolated form a human library thus, it is not immunogenic for humans and could serve as a potential therapeutic agent in cancer.

  5. -Human Chorionic Gonadotropin Production

    Directory of Open Access Journals (Sweden)

    Michael J. Russell

    2008-01-01

    Full Text Available Dedifferentiated liposarcomas may display a variety of “heterologous” lines of differentiation, including osseous, vascular, skeletal, and/or smooth muscular. There have been six previously reported examples of leiomyosarcomas associated with high levels of serum human chorionic gonadotropin (hCG production, comprised of cases originating from the retroperitoneum, spermatic cord, small intestine, and uterus. This report describes the first example of a dedifferentiated liposarcoma that combined both of the aforementioned features: extensive heterologous (leiomyosarcomatous differentiation and -hCG production (maximum serum levels 1046 mIU/ml, reference <5 mIU/ml. The tumor, which originated in the retroperitoneum in the region of the right kidney, was rapidly progressive and ultimately fatal within three months of its diagnosis. In addition to characteristic morphologic features, lipogenic and smooth muscle differentiation were confirmed with immunohistochemical stains for MDM2 and smooth muscle actin, respectively. The tumor also displayed diffuse immunoreactivity for -hCG in both primary and metastatic sites. This case further expands the clinicopathologic spectrum of lipogenic tumors.

  6. NCI Requests Targets for Monoclonal Antibody Production and Characterization - Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    In an effort to provide well-characterized monoclonal antibodies to the scientific community, NCI's Antibody Characterization Program requests cancer-related protein targets for affinity production and distribution.

  7. Use of Taguchi's methods as a basis to optimize hybridoma cell line growth and antibody production in a spinner flask

    OpenAIRE

    Kallel, Héla; Zaïri, Hind; Rourou, Samia; Essafi, Makram; Barbouche, Ridha; Dellagi, Koussay; Fathallah, Dahmani M.

    2002-01-01

    Taguchi’s methods were used for the design of an experimental strategy aimed at optimizing cell density and monoclonal antibody (mAb) production from a spinner flask hybridoma culture. 23G11 is an antibody to the human leukocyte adhesion molecule, CR3 or β 2 integrin (CD11b/CD18). It recognizes specifically the A-domain of the α subunit CD11b. Anti β 2 integrin monoclonal antibodies hold a great potential for preventing inflammation mediated tissue injuries. An L8 orthogonal experimental desi...

  8. Primary structure and functional scFv antibody expression of an antibody against the human protooncogen c-myc.

    Science.gov (United States)

    Fuchs, P; Breitling, F; Little, M; Dübel, S

    1997-06-01

    The immunoglobulin heavy- and light-chain variable region (Vh and Vl) genes were isolated from Myc1-9E10 hybridoma cells, which secreted monoclonal antibody against human oncogen c-myc. The expression vector pOPE52-c-myc was constructed for the recombinant production in E. coli. A 30 kDa single chain fragment (scFv) expression product was found in the periplasmic space by SDS-PAGE and immunoblotting. A significant fraction was processed correctly as demonstrated with an antiserum recognizing the processed aminoterminus only. The specific binding of the scFv fragment to the peptide epitope of the maternal monoclonal antibody was demonstrated and the primary sequence of the variable regions was determined. Sequence comparison with previously published partial Vh and Vl sequences from this hybridoma cell line revealed a genetic heterogeneity for the light chain variable region. The potential use of this scFv as a new tool for detection and purification of tagged proteins, for adding costimulatory signals to the surface of cancer cells as well as for analyzing c-myc function in the living cell by cytoplasmic expression is discussed.

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

    Directory of Open Access Journals (Sweden)

    Hiroyuki Tanaka

    2012-01-01

    Full Text Available We succeeded in developing the fingerprint of natural product by eastern blotting using monoclonal antibodies. After developing and separating them on a TLC plate, solasodine glycosides are oxidized by NaIO4 and reacted with a protein to give conjugates which are recognized with anti-solamargine monoclonal antibody (MAb. Anti-solamargine MAb having wide cross-reactivity can stain and detect all solasodine glycosides by fingerprint. Different sensitivity between solamargine and solasonine was observed. The detection limit was 1.6 ng of solasonine. The hydrolysed products of solamargine were determined by fingerprint of eastern blotting compared to their Rf values depending on the sugar number. Fingerprint by eastern blotting using anti-ginsenoside Rb1 MAb distinguished the formula containing ginseng prescribed in traditional Chinese medicine. By double-staining of ginsenosides it is possible to suggest that the staining color shows the pharmacological activity, such as the purple bands indicate ginsenosides having stimulation activity, and the blue color indicated compound like ginsenosides possessed the depression affect for the central nervous system (CNS, respectively.

  10. Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

    Science.gov (United States)

    Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

    2015-06-01

    In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population.

  11. Antibodies specific for a segment of human membrane IgE deplete IgE-producing B cells in humanized mice.

    Science.gov (United States)

    Brightbill, Hans D; Jeet, Surinder; Lin, Zhonghua; Yan, Donghong; Zhou, Meijuan; Tan, Martha; Nguyen, Allen; Yeh, Sherry; Delarosa, Donnie; Leong, Steven R; Wong, Terence; Chen, Yvonne; Ultsch, Mark; Luis, Elizabeth; Ramani, Sree Ranjani; Jackman, Janet; Gonzalez, Lino; Dennis, Mark S; Chuntharapai, Anan; DeForge, Laura; Meng, Y Gloria; Xu, Min; Eigenbrot, Charles; Lee, Wyne P; Refino, Canio J; Balazs, Mercedesz; Wu, Lawren C

    2010-06-01

    IgE-mediated hypersensitivity is central to the pathogenesis of asthma and other allergic diseases. Although neutralization of serum IgE with IgE-specific antibodies is in general an efficacious treatment for allergic asthma, one limitation of this approach is its lack of effect on IgE production. Here, we have developed a strategy to disrupt IgE production by generating monoclonal antibodies that target a segment of membrane IgE on human IgE-switched B cells that is not present in serum IgE. This segment is known as the M1' domain, and using genetically modified mice that contain the human M1' domain inserted into the mouse IgE locus, we demonstrated that M1'-specific antibodies reduced serum IgE and IgE-producing plasma cells in vivo, without affecting other immunoglobulin isotypes. M1'-specific antibodies were effective when delivered prophylactically and therapeutically in mouse models of immunization, allergic asthma, and Nippostrongylus brasiliensis infection, likely by inducing apoptosis of IgE-producing B cells. In addition, we generated a humanized M1'-specific antibody that was active on primary human cells in vivo, as determined by its reduction of serum IgE levels and IgE plasma cell numbers in a human PBMC-SCID mouse model. Thus, targeting of human IgE-producing B cells with apoptosis-inducing M1'-specific antibodies may be a novel treatment for asthma and allergy.

  12. Reduced binding of human antibodies to cells from GGTA1/CMAH KO pigs.

    Science.gov (United States)

    Burlak, C; Paris, L L; Lutz, A J; Sidner, R A; Estrada, J; Li, P; Tector, M; Tector, A J

    2014-08-01

    Xenotransplantation using genetically modified pig organs could solve the donor organ shortage problem. Two inactivated genes that make humans unique from pigs are GGTA1 and CMAH, the products of which produce the carbohydrate epitopes, aGal and Neu5Gc that attract preformed human antibody. When the GGTA1 and CMAH genes were deleted in pigs, human antibody binding was reduced in preliminary analysis. We analyzed the binding of human IgM and IgG from 121 healthy human serum samples for binding to GGTA1 KO and GGTA1/CMAH KO peripheral blood mononuclear cells (PBMCs). We analyzed a sub population for reactivity toward genetically modified pig PBMCs as compared to chimpanzee and human PBMCs. Deletion of the GGTA1 and CMAH genes in pigs improved the crossmatch results beyond those observed with chimpanzees. Sorting the 121 human samples tested against the GGTA1/CMAH KO pig PBMCs did not reveal a distinguishing feature such as blood group, age or gender. Modification of genes to make pig carbohydrates more similar to humans has improved the crossmatch with human serum significantly.

  13. Expression of Human Immunodeficiency Virus Type 1 Neutralizing Antibody Fragments Using Human Vaginal Lactobacillus

    Science.gov (United States)

    Marcobal, Angela; Liu, Xiaowen; Zhang, Wenlei; Dimitrov, Antony S.; Jia, Letong; Lee, Peter P.; Fouts, Timothy R.; Parks, Thomas P.

    2016-01-01

    Abstract Eradication of human immunodeficiency virus type 1 (HIV-1) by vaccination with epitopes that produce broadly neutralizing antibodies is the ultimate goal for HIV prevention. However, generating appropriate immune responses has proven difficult. Expression of broadly neutralizing antibodies by vaginal colonizing lactobacilli provides an approach to passively target these antibodies to the mucosa. We tested the feasibility of expressing single-chain and single-domain antibodies (dAbs) in Lactobacillus to be used as a topical microbicide/live biotherapeutic. Lactobacilli provide an excellent platform to express anti-HIV proteins. Broadly neutralizing antibodies have been identified against epitopes on the HIV-1 envelope and have been made into active antibody fragments. We tested single-chain variable fragment m9 and dAb-m36 and its derivative m36.4 as prototype antibodies. We cloned and expressed the antibody fragments m9, m36, and m36.4 in Lactobacillus jensenii-1153 and tested the expression levels and functionality. We made a recombinant L. jensenii 1153-1128 that expresses dAb-m36.4. All antibody fragments m9, m36, and m36.4 were expressed by lactobacilli. However, we noted the smaller m36/m36.4 were expressed to higher levels, ≥3 μg/ml. All L. jensenii-expressed antibody fragments bound to gp120/CD4 complex; Lactobacillus-produced m36.4 inhibited HIV-1BaL in a neutralization assay. Using a TZM-bl assay, we characterized the breadth of neutralization of the m36.4. Delivery of dAbs by Lactobacillus could provide passive transfer of these antibodies to the mucosa and longevity at the site of HIV-1 transmission. PMID:26950606

  14. 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...

  15. Phage display-derived human antibodies in clinical development and therapy.

    Science.gov (United States)

    Frenzel, André; Schirrmann, Thomas; Hust, Michael

    2016-10-01

    Over the last 3 decades, monoclonal antibodies have become the most important class of therapeutic biologicals on the market. Development of therapeutic antibodies was accelerated by recombinant DNA technologies, which allowed the humanization of murine monoclonal antibodies to make them more similar to those of the human body and suitable for a broad range of chronic diseases like cancer and autoimmune diseases. In the early 1990s in vitro antibody selection technologies were developed that enabled the discovery of "fully" human antibodies with potentially superior clinical efficacy and lowest immunogenicity. Antibody phage display is the first and most widely used of the in vitro selection technologies. It has proven to be a robust, versatile platform technology for the discovery of human antibodies and a powerful engineering tool to improve antibody properties. As of the beginning of 2016, 6 human antibodies discovered or further developed by phage display were approved for therapy. In 2002, adalimumab (Humira®) became the first phage display-derived antibody granted a marketing approval. Humira® was also the first approved human antibody, and it is currently the best-selling antibody drug on the market. Numerous phage display-derived antibodies are currently under advanced clinical investigation, and, despite the availability of other technologies such as human antibody-producing transgenic mice, phage display has not lost its importance for the discovery and engineering of therapeutic antibodies. Here, we provide a comprehensive overview about phage display-derived antibodies that are approved for therapy or in clinical development. A selection of these antibodies is described in more detail to demonstrate different aspects of the phage display technology and its development over the last 25 years.

  16. Generation and tumor recognition properties of two human monoclonal antibodies specific to cell surface anionic phospholipids.

    Science.gov (United States)

    Bujak, Emil; Pretto, Francesca; Neri, Dario

    2015-08-01

    Phosphatidylserine (PS) and other anionic phospholipids, which become exposed on the surface of proliferating endothelial cells, tumor cells and certain leukocytes, have been used as targets for the development of clinical-stage biopharmaceuticals. One of these products (bavituximab) is currently being investigated in Phase 3 clinical trials. There are conflicting reports on the ability of bavituximab and other antibodies to recognize PS directly or through beta-2 glycoprotein 1, a serum protein that is not highly conserved across species. Here, we report on the generation and characterization of two fully human antibodies directed against phosphatidylserine. One of these antibodies (PS72) bound specifically to phosphatidylserine and to phosphatidic acid, but did not recognize other closely related phospholipids, while the other antibody (PS41) also bound to cardiolipin. Both PS72 and PS41 stained 8/9 experimental tumor models in vitro, but both antibodies failed to exhibit a preferential tumor accumulation in vivo, as revealed by quantitative biodistribution analysis. Our findings indicate that anionic phospholipids are exposed and accessible in most tumor types, but cast doubts about the possibility of efficiently targeting tumors in vivo with PS-specific reagents.

  17. Activation of human complement by immunoglobulin G antigranulocyte antibody.

    Science.gov (United States)

    Rustagi, P K; Currie, M S; Logue, G L

    1982-01-01

    The ability of antigranulocyte antibody to fix the third component of complement (C3) to the granulocyte surface was investigated by an assay that quantitates the binding of monoclonal anti-C3 antibody to paraformaldehyde-fixed cells preincubated with Felty's syndrome serum in the presence of human complement. The sera from 7 of 13 patients with Felty's syndrome bound two to three times as much C3 to granulocytes as sera from patients with uncomplicated rheumatoid arthritis. The complement-activating ability of Felty's syndrome serum seemed to reside in the monomeric IgG-containing serum fraction. For those sera capable of activating complement, the amount of C3 fixed to granulocytes was proportional to the amount of granulocyte-binding IgG present in the serum. Thus, complement fixation appeared to be a consequence of the binding of antigranulocyte antibody to the cell surface. These studies suggest a role for complement-mediated injury in the pathophysiology of immune granulocytopenia, as has been demonstrated for immune hemolytic anemia and immune thrombocytopenia. PMID:7174786

  18. RA8, A human anti-CD25 antibody against human treg cells

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Robyn; Flanagan, Meg; Miller, Keith D.; Nien, Yu-Chih; Hu, Peisheng; Gray, Dixon; Khawli, Leslie A.; Epstein, Alan L.

    2007-06-01

    Although anti-CD25 antibodies exist for clinical use in patients, there is a need for the development of a human Treg antibody that will abrogate the immunosuppressive function of this small but critical T cell subtype. Based upon mounting evidence that the level of Treg cells in the tumor microenvironment correlates with clinical prognosis and stage in man, it appears that Treg cells play an important role in the tumor's ability to overcome host immune responses. In mice, the rat anti-mouse CD25 antibody PC61 causes depletion of CD25-bearing Treg cells both peripherally in lymphatic tissues and in the tumor microenvironment, without inducing symptoms of autoimmunity. A similar antibody, though with the ability to delete Treg cells specifically, would be an important new tool for reversing tumor escape associated with Treg immunosuppression in man. To begin to generate such a reagent, we now describe the development of a human anti-CD25 antibody using a novel yeast display library. The target antigen CD25-Fc was constructed and used for five rounds of selection using a non-immune yeast display library that contained as many as 109 single chain variable fragments (scFv). Two unique clones with low KD values (RA4 and RA8) were then selected to construct fully human anti-CD25 antibodies (IgG1/kappa) for stable expression. One antibody, RA8, showed excellent binding to human CD25+ cell lines and to human Treg cells and appears to be an excellent candidate for the generation of a human reagent that may be used in man for the immunotherapy of cancer.

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

    National Research Council Canada - National Science Library

    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

    2015-01-01

    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...

  20. Production and characterization of monoclonal antibodies against mink leukocytes

    DEFF Research Database (Denmark)

    Chen, W.S.; Pedersen, Mikael; Gram-Nielsen, S.

    1997-01-01

    Three monoclonal antibodies (mAbs) were generated against mink leukocytes. One antibody reacted with all T lymphocytes, one with all monocytes and one had platelet reactivity. Under reducing conditions, the T lymphocyte reactive antibody immunoprecipitated 18 kDa, 23 kDa, 25 kDa and 32-40 kDa pol...

  1. The antibody preparation and expression of human Pescadillo

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao; NING Kang; ZHU JianHua; LI JieZhi; HUANG CuiFen; LIU AiJun; YE QiNong; LI JiePing; WANG XiaoHui; SUN Yan; YUAN Bin; YANG ZhiHong; JIANG YanChao; ZENG Min; DING LiHua

    2007-01-01

    To explore the biological roles of human Pescadillo and investigate its potential effect on tumorigene sis, the eDNA of Pescadillo was fused with that of GST. After purification and elution, the purified GST-Pescadillo fusion protein was obtained, and the antibody against the fusion protein was generated.Endogenous Pescadillo protein was observed to be remarkably induced by estrogen. It was mainly distributed in the tissues such as breast, ovary and intestine, all of which contain proliferating cells,and was also detected in many cell lines of human cancer: renal carcinoma, hepatoma, ovarian cancer,colon carcinoma, and breast cancer. The expression level of Pescadillo was increased significantly in breast cancer tissues compared with their paired margin tissues. Taken together, these data suggest that Pescadillo may play important roles in the initiation and development of cancer and may be a potential target in cancer diagnosis and therapy.

  2. The antibody preparation and expression of human Pescadillo

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To explore the biological roles of human Pescadillo and investigate its potential effect on tumorigene- sis, the cDNA of Pescadillo was fused with that of GST. After purification and elution, the purified GST-Pescadillo fusion protein was obtained, and the antibody against the fusion protein was generated. Endogenous Pescadillo protein was observed to be remarkably induced by estrogen. It was mainly distributed in the tissues such as breast, ovary and intestine, all of which contain proliferating cells, and was also detected in many cell lines of human cancer: renal carcinoma, hepatoma, ovarian cancer, colon carcinoma, and breast cancer. The expression level of Pescadillo was increased significantly in breast cancer tissues compared with their paired margin tissues. Taken together, these data suggest that Pescadillo may play important roles in the initiation and development of cancer and may be a po- tential target in cancer diagnosis and therapy.

  3. Dengue viruses are enhanced by distinct populations of serotype cross-reactive antibodies in human immune sera.

    Directory of Open Access Journals (Sweden)

    Ruklanthi de Alwis

    2014-10-01

    Full Text Available Dengue viruses (DENV are mosquito-borne flaviviruses of global importance. DENV exist as four serotypes, DENV1-DENV4. Following a primary infection, individuals produce DENV-specific antibodies that bind only to the serotype of infection and other antibodies that cross-react with two or more serotypes. People exposed to a secondary DENV infection with another serotype are at greater risk of developing more severe forms of dengue disease. The increased risk of severe dengue in people experiencing repeat DENV infections appear to be due, at least in part, to the ability of pre-existing serotype cross-reactive antibodies to form virus-antibody complexes that can productively infect Fcγ receptor-bearing target cells. While the theory of antibody-dependent enhancement (ADE is supported by several human and small animal model studies, the specific viral antigens and epitopes recognized by enhancing human antibodies after natural infections have not been fully defined. We used antibody-depletion techniques to remove DENV-specific antibody sub-populations from primary DENV-immune human sera. The effects of removing specific antibody populations on ADE were tested both in vitro using K562 cells and in vivo using the AG129 mouse model. Removal of serotype cross-reactive antibodies ablated enhancement of heterotypic virus infection in vitro and antibody-enhanced mortality in vivo. Further depletion studies using recombinant viral antigens showed that although the removal of DENV E-specific antibodies using recombinant E (rE protein resulted in a partial reduction in DENV enhancement, there was a significant residual enhancement remaining. Competition ADE studies using prM-specific Fab fragments in human immune sera showed that both rE-specific and prM-specific antibodies in primary DENV-immune sera significantly contribute to enhancement of heterotypic DENV infection in vitro. Identification of the targets of DENV-enhancing antibodies should contribute to

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

    Directory of Open Access Journals (Sweden)

    Oliinyk O. S.

    2014-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Barth Stefan

    2005-01-01

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

  6. Thyroid Antibodies

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Thyroid Antibodies Share this page: Was this page helpful? Also known as: Thyroid Autoantibodies; Antithyroid Antibodies; Antimicrosomal Antibody; Thyroid Microsomal Antibody; ...

  7. Structure of a human rhinovirus-bivalently bound antibody complex: implications for viral neutralization and antibody flexibility.

    OpenAIRE

    1993-01-01

    The structure of a neutralizing immunoglobulin (monoclonal antibody mAb17-IA), bound to human rhinovirus 14 (HRV14), has been determined by cryo-electron microscopy and image reconstruction. The antibody bound bivalently across icosahedral twofold axes of the virus, and there were no detectable conformational changes in the capsid. Thus, bivalently bound IgGs do not appear to cause gross deformations in the capsid. Differences between the electron density of the constant domains of the bound ...

  8. An ELISA for detection of antibodies against influenza A nucleoprotein in humans and various animal species.

    NARCIS (Netherlands)

    G.F. de Boer; W. Back; A.D.M.E. Osterhaus (Albert)

    1990-01-01

    textabstractA double antibody sandwich blocking ELISA, using a monoclonal antibody (MAb) against influenza A nucleoprotein (NP) was developed to detect antibodies against influenza. Collections of serum samples were obtained from human and various animal species. All influenza A subtypes induced ant

  9. An anti-human ICAM-1 antibody inhibits rhinovirus-induced exacerbations of lung inflammation.

    Directory of Open Access Journals (Sweden)

    Stephanie Traub

    Full Text Available Human rhinoviruses (HRV cause the majority of common colds and acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD. Effective therapies are urgently needed, but no licensed treatments or vaccines currently exist. Of the 100 identified serotypes, ∼90% bind domain 1 of human intercellular adhesion molecule-1 (ICAM-1 as their cellular receptor, making this an attractive target for development of therapies; however, ICAM-1 domain 1 is also required for host defence and regulation of cell trafficking, principally via its major ligand LFA-1. Using a mouse anti-human ICAM-1 antibody (14C11 that specifically binds domain 1 of human ICAM-1, we show that 14C11 administered topically or systemically prevented entry of two major groups of rhinoviruses, HRV16 and HRV14, and reduced cellular inflammation, pro-inflammatory cytokine induction and virus load in vivo. 14C11 also reduced cellular inflammation and Th2 cytokine/chemokine production in a model of major group HRV-induced asthma exacerbation. Interestingly, 14C11 did not prevent cell adhesion via human ICAM-1/LFA-1 interactions in vitro, suggesting the epitope targeted by 14C11 was specific for viral entry. Thus a human ICAM-1 domain-1-specific antibody can prevent major group HRV entry and induction of airway inflammation in vivo.

  10. Efficient antibody production in the methylotrophic yeast Ogataea minuta by overexpression of chaperones.

    Science.gov (United States)

    Suzuki, Takeshi; Baba, Satoshi; Ono, Minako; Nonaka, Koichi; Ichikawa, Kimihisa; Yabuta, Masayuki; Ito, Rie; Chiba, Yasunori

    2017-08-01

    A production system for a therapeutic monoclonal antibody was developed using the methylotrophic yeast Ogataea minuta IFO10746. The genetically engineered O. minuta secreted a detectable amount of anti-TRAIL receptor antibody into the culture supernatant, and the secreted antibody was purified by multiple column chromatography steps. In the purification process, both fully and partially assembled antibodies were detected and isolated. The fully assembled antibody from O. minuta showed almost the same biological activity as that derived from mammalian cells despite the distinct glycosylation profile, whereas the partially assembled antibody showed no cytotoxic activity. To increase the production of active antibody in O. minuta, we overexpressed selected chaperone proteins (included protein disulfide isomerase (OmPDI1), thiol oxidase (OmERO1), and immunoglobulin heavy chain binding protein (OmKAR2)) known to assist in the proper folding (in the endoplasmic reticulum) of proteins destined for secretion. Each of these chaperones enhanced antibody secretion, and together these three factors yielded 16-fold higher antibody accumulation while increasing the ratio of the fully assembled antibody compared to that from the parental strain. Supplementation of a rhodanine-3-acetic acid derivative (R3AD_1c), an inhibitor of O-mannosylation, further increased the secretion of the correctly assembled antibody. These results indicated that the co-overexpression of chaperones is an effective way to produce the correctly assembled antibody in O. minuta. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Recommendations for the validation of immunoassays used for detection of host antibodies against biotechnology products.

    Science.gov (United States)

    Shankar, Gopi; Devanarayan, Viswanath; Amaravadi, Lakshmi; Barrett, Yu Chen; Bowsher, Ronald; Finco-Kent, Deborah; Fiscella, Michele; Gorovits, Boris; Kirschner, Susan; Moxness, Michael; Parish, Thomas; Quarmby, Valerie; Smith, Holly; Smith, Wendell; Zuckerman, Linda A; Koren, Eugen

    2008-12-15

    Most biological drug products elicit some level of anti-drug antibody (ADA) response. This antibody response can, in some cases, lead to potentially serious side effects and/or loss of efficacy. In humans, ADA often causes no detectable clinical effects, but in the instances of some therapeutic proteins these antibodies have been shown to cause a variety of clinical consequences ranging from relatively mild to serious adverse events. In nonclinical (preclinical) studies, ADA can affect drug exposure, complicating the interpretation of the toxicity, pharmacokinetic (PK) and pharmacodynamic (PD) data. Therefore, the immunogenicity of therapeutic proteins is a concern for clinicians, manufacturers and regulatory agencies. In order to assess the immunogenic potential of biological drug molecules, and be able to correlate laboratory results with clinical events, it is important to develop reliable laboratory test methods that provide valid assessments of antibody responses in both nonclinical and clinical studies. For this, method validation is considered important, and is a necessary bioanalytical component of drug marketing authorization applications. Existing regulatory guidance documents dealing with the validation of methods address immunoassays in a limited manner, and in particular lack information on the validation of immunogenicity methods. Hence this article provides scientific recommendations for the validation of ADA immunoassays. Unique validation performance characteristics are addressed in addition to those provided in existing regulatory documents pertaining to bioanalyses. The authors recommend experimental and statistical approaches for the validation of immunoassay performance characteristics; these recommendations should be considered as examples of best practice and are intended to foster a more unified approach to antibody testing across the biopharmaceutical industry.

  12. 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.

  13. Humans Have Antibodies against a Plant Virus: Evidence from Tobacco Mosaic Virus

    Science.gov (United States)

    Liu, Ruolan; Vaishnav, Radhika A.; Roberts, Andrew M.; Friedland, Robert P.

    2013-01-01

    Tobacco mosaic virus (TMV), a widespread plant pathogen, is found in tobacco (including cigarettes and smokeless tobacco) as well as in many other plants. Plant viruses do not replicate or cause infection in humans or other mammals. This study was done to determine whether exposure to tobacco products induces an immune response to TMV in humans. Using a sandwich ELISA assay, we detected serum anti-TMV antibodies (IgG, IgG1, IgG3, IgG4, IgA, and IgM) in all subjects enrolled in the study (20 healthy smokers, 20 smokeless-tobacco users, and 20 non-smokers). Smokers had a higher level of serum anti-TMV IgG antibodies than non-smokers, while the serum level of anti-TMV IgA from smokeless tobacco users was lower than smokers and non-smokers. Using bioinformatics, we also found that the human protein TOMM40L (an outer mitochondrial membrane 40 homolog – like translocase) contains a strong homology of six contiguous amino acids to the TMV coat protein, and TOMM40L peptide exhibited cross-reactivity with anti-TMV antibodies. People who smoke cigarettes or other tobacco products experience a lower risk of developing Parkinson’s disease, but the mechanism by which this occurs is unclear. Our results showing molecular mimicry between TMV and human TOMM40L raise the question as to whether TMV has a potential role in smokers against Parkinson’s disease development. The potential mechanisms of molecular mimicry between plant viruses and human disease should be further explored. PMID:23573274

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

    Directory of Open Access Journals (Sweden)

    Ajda Biček

    2004-01-01

    Full Text Available Chicken antibodies are not only a part of immune defense but are more and more popular commercial products in form of chicken polyclonal, monoclonal or recombinant antibodies. We produced and characterized mouse monoclonal antibodies (mAbs that recognize epitopes located on heavy or light chain of chicken immunoglobulin Y (chIgY shared also by some other Phasianidae birds. The use of mAbs 1F5 and 2F10 that recognize heavy chain on chIgY common epitopes was demonstrated on immunoglobulins of turkey, pheasant and peafowl. Chicken IgY light chain specific mAb 3E10 revealed the presence of common epitopes on immunoglobulins of turkey, pheasant and sparrow. Monoclonal antibody clone 1F5/3G2 was used to prepare horseradish peroxidase (HRP conjugate and immunoadsorbent column. Conjugated mAbs were demonstrated to be excellent secondary antibodies for diagnostics of certain infections in different avian species. Since they do not react with mammalian immunoglobulins using our mAbs as secondary antibodies in human serodiagnostics would minimize background staining that appears when using mouse detection system. In dot immunobinding assay (DIBA and immunoblot assay they recognized specific IgY antibodies against Mycoplasma synoviae, Mycoplasma gallisepticum and Newcastle disease virus in sera of infected or vaccinated birds. Immunoadsorption as a method for removal of IgY from samples in which Mycoplasma synoviae specific IgY was predominant immunoglobulin class enabled more exact demonstration of specific IgA and IgM antibodies. Herein we are presenting effective mAbs useful in diagnostics of avian and mammalian infections as well as in final steps of detection and purification of chicken antibodies and their subunits produced in vivo or in vitro as polyclonal, monoclonal or recombinant antibodies.

  15. Purification of human monoclonal antibodies and their fragments.

    Science.gov (United States)

    Müller-Späth, Thomas; Morbidelli, Massimo

    2014-01-01

    This chapter summarizes the most common chromatographic mAb and mAb fragment purification methods, starting by elucidating the relevant properties of the compounds and introducing the various chromatography modes that are available and useful for this application. A focus is put on the capture step affinity and ion exchange chromatography. Aspects of scalability play an important role in judging the suitability of the methods. The chapter introduces also analytical chromatographic methods that can be utilized for quantification and purity control of the product. In the case of mAbs, for most purposes the purity obtained using an affinity capture step is sufficient. Polishing steps are required if material of particularly high purity needs to be generated. For mAb fragments, affinity chromatography is not yet fully established, and the capture step potentially may not provide material of high purity. Therefore, the available polishing techniques are touched upon briefly. In the case of mAb isoform and bispecific antibody purification, countercurrent chromatography techniques have been proven to be very useful and a part of this chapter has been dedicated to them, paying tribute to the rising interest in these antibody formats in research and industry.

  16. Detection of auto-anti-idiotypic antibodies to Lol p I (rye I) IgE antibodies in human sera by the use of murine idiotypes: levels in atopic and non-atopic subjects and effects of immunotherapy.

    Science.gov (United States)

    Hébert, J; Bernier, D; Mourad, W

    1990-06-01

    Anti-idiotypic antibodies (anti-Id Abs) are involved in the regulation of a number of immune responses including the IgE antibody production. In atopic patients, the increased synthesis of IgE antibodies could be related to a defective production of regulatory anti-Id Abs. In the present study, we first developed a sensitive assay for measuring the levels of anti-Id Abs directed against antibodies specific for Lol p I, the major allergenic determinant of Lolium perenne (rye grass). In this assay, we used previously described murine monoclonal anti-Lol p I antibodies that were shown to share epitopic specificities with human anti-Lol p I IgE and IgG antibodies, thus short-cutting the need for purification of F(ab')2 fragments of human IgG Abs and insuring optimal specificity and sensitivity. Levels of anti-Id Abs against two anti-Lol p I monoclonal antibodies (290A-167, 348A-6) were higher in normal volunteers than in untreated atopic patients. Specific immunotherapy increased the levels of anti-Id Abs to those of normal volunteers. These observations suggest a role for the Id-anti-Id network in the regulation of IgE antibody production.

  17. Neutralization of Botulinum Neurotoxin Type E by a Humanized Antibody

    Science.gov (United States)

    Derman, Yağmur; Selby, Katja; Miethe, Sebastian; Frenzel, André; Liu, Yvonne; Rasetti-Escargueil, Christine; Avril, Arnaud; Pelat, Thibaut; Urbain, Remi; Fontayne, Alexandre; Thullier, Philippe; Sesardic, Dorothea; Lindström, Miia; Hust, Michael; Korkeala, Hannu

    2016-01-01

    Botulinum neurotoxins (BoNTs) cause botulism and are the deadliest naturally-occurring substances known to humans. BoNTs have been classified as one of the category A agents by the Centers for Disease Control and Prevention, indicating their potential use as bioweapons. To counter bio-threat and naturally-occurring botulism cases, well-tolerated antibodies by humans that neutralize BoNTs are relevant. In our previous work, we showed the neutralizing potential of macaque (Macaca fascicularis)-derived scFv-Fc (scFv-Fc ELC18) by in vitro endopeptidase immunoassay and ex vivo mouse phrenic nerve-hemidiaphragm assay by targeting the light chain of the botulinum neurotoxin type E (BoNT/E). In the present study, we germline-humanized scFv-Fc ELC18 into a full IgG hu8ELC18 to increase its immunotolerance by humans. We demonstrated the protection and prophylaxis capacity of hu8ELC18 against BoNT/E in a mouse model. A concentration of 2.5 ng/mouse of hu8ELC18 protected against 5 mouse lethal dose (MLD) in a mouse protection assay and complete neutralization of 1 LD50 of pure BoNT/E toxin was achieved with 8 ng of hu8ELC18 in mouse paralysis assay. Furthermore, hu8ELC18 protected mice from 5 MLD if injected up to 14 days prior to intraperitoneal BoNT/E administration. This newly-developed humanized IgG is expected to have high tolerance in humans. PMID:27626446

  18. Neutralization of Botulinum Neurotoxin Type E by a Humanized Antibody

    Directory of Open Access Journals (Sweden)

    Yağmur Derman

    2016-09-01

    Full Text Available Botulinum neurotoxins (BoNTs cause botulism and are the deadliest naturally-occurring substances known to humans. BoNTs have been classified as one of the category A agents by the Centers for Disease Control and Prevention, indicating their potential use as bioweapons. To counter bio-threat and naturally-occurring botulism cases, well-tolerated antibodies by humans that neutralize BoNTs are relevant. In our previous work, we showed the neutralizing potential of macaque (Macaca fascicularis-derived scFv-Fc (scFv-Fc ELC18 by in vitro endopeptidase immunoassay and ex vivo mouse phrenic nerve-hemidiaphragm assay by targeting the light chain of the botulinum neurotoxin type E (BoNT/E. In the present study, we germline-humanized scFv-Fc ELC18 into a full IgG hu8ELC18 to increase its immunotolerance by humans. We demonstrated the protection and prophylaxis capacity of hu8ELC18 against BoNT/E in a mouse model. A concentration of 2.5 ng/mouse of hu8ELC18 protected against 5 mouse lethal dose (MLD in a mouse protection assay and complete neutralization of 1 LD50 of pure BoNT/E toxin was achieved with 8 ng of hu8ELC18 in mouse paralysis assay. Furthermore, hu8ELC18 protected mice from 5 MLD if injected up to 14 days prior to intraperitoneal BoNT/E administration. This newly-developed humanized IgG is expected to have high tolerance in humans.

  19. Use of Taguchi's methods as a basis to optimize hybridoma cell line growth and antibody production in a spinner flask.

    Science.gov (United States)

    Kallel, Héla; Zaïri, Hind; Rourou, Samia; Essafi, Makram; Barbouche, Ridha; Dellagi, Koussay; Fathallah, Dahmani M

    2002-05-01

    Taguchi's methods were used for the design of an experimental strategy aimed at optimizing cell density and monoclonal antibody (mAb) production from a spinner flask hybridoma culture. 23G11 is an antibody to the human leukocyte adhesion molecule, CR3 or beta 2 integrin (CD11b/CD18). It recognizes specifically the A-domain of the alpha subunit CD11b. Anti beta 2 integrin monoclonal antibodies hold a great potential for preventing inflammation mediated tissue injuries. An L8 orthogonal experimental design was used to investigate four different culture components: stirring speed, nature of serum, concentration of serum and nature of media (RPMI 1640 or RPMI 1640 supplemented with glucose and glutamine). The experiments were conducted using two levels for each factor studied and a direct ELISA test was used to estimate the level of antibody production. Statistical analysis of the collected data pointed to the stirring speed and serum concentration, and the interaction between these parameters, as the components that affected cell growth. Antibody production was affected by these factors and by the nature of medium but also by the following two interactions: stirring speed/nature of serum and stirring speed/concentration of serum. This study emphasizes the value of using Taguchi's methods as a basis for optimization of mAb production from a hybridoma culture, in cost effective and significantly less labor intensive ways.

  20. Human immunodeficiency virus antibody test and seroprevalence in psychiatric patients.

    Science.gov (United States)

    Naber, D; Pajonk, F G; Perro, C; Löhmer, B

    1994-05-01

    Psychiatric inpatients are at risk for human immunodeficiency virus (HIV) infection. Investigations in the United States revealed seroprevalence rates of 5.5-8.9%. Therefore, inclusion of HIV antibody testing in routine laboratory screening is sometimes suggested. To investigate this issue for inpatients in the Department of Psychiatry, University of Munich, the incidence, reason for HIV testing and results were analyzed. Of 12,603 patients, hospitalized from 1985 to 1993, 4.9% (623 patients, 265 in risk groups) underwent the HIV test after informed consent. Thirty patients (4.8% of those tested) were found to be positive, but only in 5 cases (all of risk groups) was infection newly detected. Data indicate that, in psychiatry, HIV testing is reasonable only in patients in risk groups or if clinical variables suggest HIV infection.

  1. 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...

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

    OpenAIRE

    Oliinyk O. S.; Kaberniuk A. A.; Kolibo D. V.; Komisarenko S. V.

    2014-01-01

    Diphtheria toxin is an exoantigen of Corynebacterium diphtheriae that inhibits protein synthesis and kills sensitive cells. The aim of this study was to obtain human recombinant single-chain variable fragment (scFv) antibodies against receptor-binding B subunit of diphtheria toxin. 12 specific clones were selected after three rounds of a phage display naїve (unimmunized) human antibody library against recombinant B-subunit. scFv DNA inserts from these 12 clones were digested with MvaI, an...

  3. Advances in alloimmune thrombocytopenia: perspectives on current concepts of human platelet antigens, antibody detection strategies, and genotyping.

    Science.gov (United States)

    Hayashi, Tomoya; Hirayama, Fumiya

    2015-07-01

    Alloimmunisation to platelets leads to the production of antibodies against platelet antigens and consequently to thrombocytopenia. Numerous molecules located on the platelet surface are antigenic and induce immune-mediated platelet destruction with symptoms that can be serious. Human platelet antigens (HPA) cause thrombocytopenias, such as neonatal alloimmune thrombocytopenia, post-transfusion purpura, and platelet transfusion refractoriness. Thirty-four HPA are classified into 28 systems. Assays to identify HPA and anti-HPA antibodies are critically important for preventing and treating thrombocytopenia caused by anti-HPA antibodies. Significant progress in furthering our understanding of HPA has been made in the last decade: new HPA have been discovered, antibody-detection methods have improved, and new genotyping methods have been developed. We review these advances and discuss issues that remain to be resolved as well as future prospects for preventing and treating immune thrombocytopenia.

  4. Algae as protein factories: expression of a human antibody and the respective antigen in the diatom Phaeodactylum tricornutum.

    Directory of Open Access Journals (Sweden)

    Franziska Hempel

    Full Text Available Microalgae are thought to offer great potential as expression system for various industrial, therapeutic and diagnostic recombinant proteins as they combine high growth rates with all benefits of eukaryotic expression systems. Moreover, microalgae exhibit a phototrophic lifestyle like land plants, hence protein expression is fuelled by photosynthesis, which is CO(2-neutral and involves only low production costs. So far, however, research on algal bioreactors for recombinant protein expression is very rare calling for further investigations in this highly promising field. In this study, we present data on the expression of a monoclonal human IgG antibody against the Hepatitis B surface protein and the respective antigen in the diatom Phaeodactylum tricornutum. Antibodies are fully-assembled and functional and accumulate to 8.7% of total soluble protein, which complies with 21 mg antibody per gram algal dry weight. The Hepatitis B surface protein is functional as well and is recognized by algae-produced and commercial antibodies.

  5. A variety of human monoclonal antibodies against epidermal growth factor receptor isolated from a phage antibody library.

    Science.gov (United States)

    Kurosawa, Gene; Kondo, Mariko; Kurosawa, Yoshikazu

    2016-11-04

    When the technology for constructing human antibody (Ab) libraries using a phage-display system was developed, many researchers in Ab-related fields anticipated that it would be widely applied to the development of pharmaceutical drugs against various diseases, including cancers. However, successful examples of such applications are very limited. Moreover, researchers who utilize phage-display technology now show divergent ways of thinking about phage Ab libraries. For example, there is debate about what should be the source of VH and VL genes for the construction of libraries to cover the whole repertoire of Abs present in the human body. In the immune system, the introduction of mutations into V genes followed by selection based on binding activity, termed Ab maturation, is required for the production of Abs exhibiting high affinity to the antigen (Ag). Therefore, introduction of mutations and selection are required for isolation of Abs with high affinity after isolation of clones from phage Ab libraries. We constructed a large human Ab library termed AIMS, developed a screening method termed ICOS, and succeeded in isolating many human monoclonal Abs (mAbs) that specifically and strongly bind to various tumor-associated Ags. Eight anti-EGFR mAbs were included, which we characterized. These mAbs showed various different activities against EGFR-expressing cancer cells. In this paper, we describe these data and discuss the possibility and necessity that the mAbs isolated from the AIMS library might be developed as therapeutic drugs against cancers without introduction of mutations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Addressing the Immunogenicity of the Cargo and of the Targeting Antibodies with a Focus on Demmunized Bacterial Toxins and on Antibody-Targeted Human Effector Proteins.

    Science.gov (United States)

    Grinberg, Yehudit; Benhar, Itai

    2017-06-02

    Third-generation immunotoxins are composed of a human, or humanized, targeting moiety, usually a monoclonal antibody or an antibody fragment, and a non-human effector molecule. Due to the non-human origin of the cytotoxic domain, these molecules stimulate potent anti-drug immune responses, which limit treatment options. Efforts are made to deimmunize such immunotoxins or to combine treatment with immunosuppression. An alternative approach is using the so-called "human cytotoxic fusion proteins", in which antibodies are used to target human effector proteins. Here, we present three relevant approaches for reducing the immunogenicity of antibody-targeted protein therapeutics: (1) reducing the immunogenicity of the bacterial toxin, (2) fusing human cytokines to antibodies to generate immunocytokines and (3) addressing the immunogenicity of the targeting antibodies.

  7. Overcoming the susceptibility gap between maternal antibody disappearance and auto-antibody production.

    Science.gov (United States)

    Yosipovich, Roni; Aizenshtein, Elina; Shadmon, Roy; Krispel, Simcha; Shuster, Efrat; Pitcovski, Jacob

    2015-01-09

    In the first 10-14 days of a chick's life, protection is conferred by maternal antibodies. Further broiler protection is achieved by active vaccination. However, the high level of maternal antibodies interferes with the induction of an effective immune response by vaccination at a young age. As a result, there is a gap between the reduction in protective maternal antibodies and elevation of self-produced antibodies following active vaccination. The major aim of this study was to test an approach consisting of passive and active vaccination to overcome this gap and to provide continuous resistance to infectious viral diseases during the broiler's growth period. Newcastle disease virus (NDV), which is one of the world's most prevalent infectious diseases of poultry, was tested as a model. Following subcutaneous injection of 18 hemagglutination-inhibiting (HI) units of anti-NDV immunoglobulin Y per 1-day-old chick, protective log2 antibody titers above 4 could be detected to at least 17 days of age. The combination of passive immunization on day 1 of age with attenuated live vaccination on day 10 led to high protective titers throughout the entire growth period, up to 41 days of age. Moreover, the HI titers in the group of birds immunized with the combined vaccination were significantly more homogeneous than those in the group vaccinated only with live virus. Thus, full protection against NDV of all broilers in flock during their entire growth period was achieved by a vaccination regime that combines passive immunization and live vaccination.

  8. Large Scale Generation and Characterization of Anti-Human IgA Monoclonal Antibody in Ascitic Fluid of Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Fatemeh Ezzatifar

    2015-03-01

    Full Text Available Purpose: Monoclonal antibodies are potentially powerful tools used in biomedical research, diagnosis, and treatment of infectious diseases and cancers. The monoclonal antibody against Human IgA can be used as a diagnostic application to detect infectious diseases. The aim of this study was to improve an appropriate protocol for large-scale production of mAbs against IgA. Methods: For large-scale production of the monoclonal antibody, hybridoma cells that produce monoclonal antibodies against Human IgA were injected intraperitoneally into Balb/c mice that were previously primed with 0.5 ml Pristane. After ten days, ascitic fluid was harvested from the peritoneum of each mouse. The ELISA method was carried out for evaluation of the titration of produced mAbs. The ascitic fluid was investigated in terms of class and subclass by a mouse mAb isotyping kit. MAb was purified from the ascitic fluid by ion exchange chromatography. The purity of the monoclonal antibody was confirmed by SDS-PAGE, and the purified monoclonal antibody was conjugated with HRP. Results: Monoclonal antibodies with high specificity and sensitivity against Human IgA were prepared by hybridoma technology. The subclass of antibody was IgG1 and its light chain was the kappa type. Conclusion: This conjugated monoclonal antibody could have applications in designing ELISA kits in order to diagnose different infectious diseases such as toxoplasmosis and H. Pylori.

  9. Selection and characterization of a human neutralizing antibody to human fibroblast growth factor-2

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Jun [Department of Immunology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Xiang, Jun-Jian, E-mail: txjj@jnu.edu.cn [Laboratory of Antibody Engineering, College of Life Sciences and Technologies, Jinan University, Guangzhou 510632 (China); Department of Immunology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Li, Dan [Department of Immunology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Deng, Ning; Wang, Hong; Gong, Yi-Ping [Laboratory of Antibody Engineering, College of Life Sciences and Technologies, Jinan University, Guangzhou 510632 (China)

    2010-04-09

    Compelling evidences suggest that fibroblast growth factor-2 (FGF-2) plays important roles in tumor growth, angiogenesis and metastasis. Molecules blocking the FGF-2 signaling have been proposed as anticancer agents. Through screening of a human scFv phage display library, we have isolated several human single-chain Fv fragments (scFvs) that bind to human FGF-2. After expression and purification in bacteria, one scFv, named 1A2, binds to FGF-2 with a high affinity and specificity, and completes with FGF-2 binding to its receptor. This 1A2 scFv was then cloned into the pIgG1 vector and expressed in 293T cells. The purified hIgG1-1A2 antibody showed a high binding affinity of 8 x 10{sup -9} M to rhFGF-2. In a set of vitro assays, it inhibited various biological activities of FGF-2 such as the proliferation, migration and tube formation of human umbilical vein endothelial cells. More importantly, hIgG1-1A2 antibody also efficiently blocked the growth while inducing apoptosis of glioma cells. For the first time, we generated a human anti-FGF-2 antibody with proven in vitro anti-tumor activity. It may therefore present a new therapeutic candidate for the treatment of cancers that are dependent on FGF-2 signaling for growth and survival.

  10. Anti-Lipid IgG Antibodies Are Produced via Germinal Centers in a Murine Model Resembling Human Lupus

    Science.gov (United States)

    Wong-Baeza, Carlos; Reséndiz-Mora, Albany; Donis-Maturano, Luis; Wong-Baeza, Isabel; Zárate-Neira, Luz; Yam-Puc, Juan Carlos; Calderón-Amador, Juana; Medina, Yolanda; Wong, Carlos; Baeza, Isabel; Flores-Romo, Leopoldo

    2016-01-01

    Anti-lipid IgG antibodies are produced in some mycobacterial infections and in certain autoimmune diseases [such as anti-phospholipid syndrome, systemic lupus erythematosus (SLE)]. However, few studies have addressed the B cell responses underlying the production of these immunoglobulins. Anti-lipid IgG antibodies are consistently found in a murine model resembling human lupus induced by chlorpromazine-stabilized non-bilayer phospholipid arrangements (NPA). NPA are transitory lipid associations found in the membranes of most cells; when NPA are stabilized they can become immunogenic and induce specific IgG antibodies, which appear to be involved in the development of the mouse model of lupus. Of note, anti-NPA antibodies are also detected in patients with SLE and leprosy. We used this model of lupus to investigate in vivo the cellular mechanisms that lead to the production of anti-lipid, class-switched IgG antibodies. In this murine lupus model, we found plasma cells (Gr1−, CD19−, CD138+) producing NPA-specific IgGs in the draining lymph nodes, the spleen, and the bone marrow. We also found a significant number of germinal center B cells (IgD−, CD19+, PNA+) specific for NPA in the draining lymph nodes and the spleen, and we identified in situ the presence of NPA in these germinal centers. By contrast, very few NPA-specific, extrafollicular reaction B cells (B220+, Blimp1+) were found. Moreover, when assessing the anti-NPA IgG antibodies produced during the experimental protocol, we found that the affinity of these antibodies progressively increased over time. Altogether, our data indicate that, in this murine model resembling human lupus, B cells produce anti-NPA IgG antibodies mainly via germinal centers. PMID:27746783

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

    Directory of Open Access Journals (Sweden)

    Sharad P Adekar

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

  12. Human Monoclonal Antibodies Broadly Neutralizing against Influenza B Virus

    Science.gov (United States)

    Yasugi, Mayo; Kubota-Koketsu, Ritsuko; Yamashita, Akifumi; Kawashita, Norihito; Du, Anariwa; Sasaki, Tadahiro; Nishimura, Mitsuhiro; Misaki, Ryo; Kuhara, Motoki; Boonsathorn, Naphatsawan; Fujiyama, Kazuhito; Okuno, Yoshinobu; Nakaya, Takaaki; Ikuta, Kazuyoshi

    2013-01-01

    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. PMID:23408886

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

    Directory of Open Access Journals (Sweden)

    Urs B Hagemann

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

  14. Rapid isolation of antibody from a synthetic human antibody library by repeated fluorescence-activated cell sorting (FACS.

    Directory of Open Access Journals (Sweden)

    Sung Sun Yim

    Full Text Available Antibodies and their derivatives are the most important agents in therapeutics and diagnostics. Even after the significant progress in the technology for antibody screening from huge libraries, it takes a long time to isolate an antibody, which prevents a prompt action against the spread of a disease. Here, we report a new strategy for isolating desired antibodies from a combinatorial library in one day by repeated fluorescence-activated cell sorting (FACS. First, we constructed a library of synthetic human antibody in which single-chain variable fragment (scFv was expressed in the periplasm of Escherichia coli. After labeling the cells with fluorescent antigen probes, the highly fluorescent cells were sorted by using a high-speed cell sorter, and these cells were reused without regeneration in the next round of sorting. After repeating this sorting, the positive clones were completely enriched in several hours. Thus, we screened the library against three viral antigens, including the H1N1 influenza virus, Hepatitis B virus, and Foot-and-mouth disease virus. Finally, the potential antibody candidates, which show K(D values between 10 and 100 nM against the target antigens, could be successfully isolated even though the library was relatively small (∼ 10(6. These results show that repeated FACS screening without regeneration of the sorted cells can be a powerful method when a rapid response to a spreading disease is required.

  15. Production process reproducibility and product quality consistency of transient gene expression in HEK293 cells with anti-PD1 antibody as the model protein.

    Science.gov (United States)

    Ding, Kai; Han, Lei; Zong, Huifang; Chen, Junsheng; Zhang, Baohong; Zhu, Jianwei

    2017-03-01

    Demonstration of reproducibility and consistency of process and product quality is one of the most crucial issues in using transient gene expression (TGE) technology for biopharmaceutical development. In this study, we challenged the production consistency of TGE by expressing nine batches of recombinant IgG antibody in human embryonic kidney 293 cells to evaluate reproducibility including viable cell density, viability, apoptotic status, and antibody yield in cell culture supernatant. Product quality including isoelectric point, binding affinity, secondary structure, and thermal stability was assessed as well. In addition, major glycan forms of antibody from different batches of production were compared to demonstrate glycosylation consistency. Glycan compositions of the antibody harvested at different time periods were also measured to illustrate N-glycan distribution over the culture time. From the results, it has been demonstrated that different TGE batches are reproducible from lot to lot in overall cell growth, product yield, and product qualities including isoelectric point, binding affinity, secondary structure, and thermal stability. Furthermore, major N-glycan compositions are consistent among different TGE batches and conserved during cell culture time.

  16. A novel antibody humanization method based on epitopes scanning and molecular dynamics simulation.

    Directory of Open Access Journals (Sweden)

    Ding Zhang

    Full Text Available 1-17-2 is a rat anti-human DEC-205 monoclonal antibody that induces internalization and delivers antigen to dendritic cells (DCs. The potentially clinical application of this antibody is limited by its murine origin. Traditional humanization method such as complementarity determining regions (CDRs graft often leads to a decreased or even lost affinity. Here we have developed a novel antibody humanization method based on computer modeling and bioinformatics analysis. First, we used homology modeling technology to build the precise model of Fab. A novel epitope scanning algorithm was designed to identify antigenic residues in the framework regions (FRs that need to be mutated to human counterpart in the humanization process. Then virtual mutation and molecular dynamics (MD simulation were used to assess the conformational impact imposed by all the mutations. By comparing the root-mean-square deviations (RMSDs of CDRs, we found five key residues whose mutations would destroy the original conformation of CDRs. These residues need to be back-mutated to rescue the antibody binding affinity. Finally we constructed the antibodies in vitro and compared their binding affinity by flow cytometry and surface plasmon resonance (SPR assay. The binding affinity of the refined humanized antibody was similar to that of the original rat antibody. Our results have established a novel method based on epitopes scanning and MD simulation for antibody humanization.

  17. Structure guided homology model based design and engineering of mouse antibodies for humanization.

    Science.gov (United States)

    Kurella, Vinodh B; Gali, Reddy

    2014-01-01

    No universal strategy exists for humanizing mouse antibodies, and most approaches are based on primary sequence alignment and grafting. Although this strategy theoretically decreases the immunogenicity of mouse antibodies, it neither addresses conformational changes nor steric clashes that arise due to grafting of human germline frameworks to accommodate mouse CDR regions. To address these issues, we created and tested a structure-based biologic design approach using a de novo homology model to aid in the humanization of 17 unique mouse antibodies. Our approach included building a structure-based de novo homology model from the primary mouse antibody sequence, mutation of the mouse framework residues to the closest human germline sequence and energy minimization by simulated annealing on the humanized homology model. Certain residues displayed force field errors and revealed steric clashes upon closer examination. Therefore, further mutations were introduced to rationally correct these errors. In conclusion, use of de novo antibody homology modeling together with simulated annealing improved the ability to predict conformational and steric clashes that may arise due to conversion of a mouse antibody into the humanized form and would prevent its neutralization when administered in vivo. This design provides a robust path towards the development of a universal strategy for humanization of mouse antibodies using computationally derived antibody homologous structures.

  18. Characterization of Two Human Monoclonal Antibodies Neutralizing Influenza A H7N9 Viruses

    Science.gov (United States)

    Wang, Jianmin; Chen, Zhe; Bao, Linlin; Zhang, Weijia; Xue, Ying; Pang, XingHuo; Zhang, Xi

    2015-01-01

    H7N9 was a cause of significant global health concern due to its severe infection and approximately 35% mortality in humans. By screening a Fab antibody phage library derived from patients who recovered from H7N9 infections, we characterized two human monoclonal antibodies (HuMAbs), HNIgGD5 and HNIgGH8. The epitope of these two antibodies was dependent on two residues in the receptor binding site at positions V186 and L226 of the hemagglutinin glycoprotein. Both antibodies possessed high neutralizing activity. PMID:26063436

  19. Humanization of high-affinity antibodies targeting glypican-3 in hepatocellular carcinoma

    Science.gov (United States)

    Zhang, Yi-Fan; Ho, Mitchell

    2016-01-01

    Glypican-3 (GPC3) is a cell-surface heparan sulfate proteoglycan highly expressed in hepatocellular carcinoma (HCC). We have generated a group of high-affinity mouse monoclonal antibodies targeting GPC3. Here, we report the humanization and testing of these antibodies for clinical development. We compared the affinity and cytotoxicity of recombinant immunotoxins containing mouse single-chain variable regions fused with a Pseudomonas toxin. To humanize the mouse Fvs, we grafted the combined KABAT/IMGT complementarity determining regions (CDR) into a human IgG germline framework. Interestingly, we found that the proline at position 41, a non-CDR residue in heavy chain variable regions (VH), is important for humanization of mouse antibodies. We also showed that two humanized anti-GPC3 antibodies (hYP7 and hYP9.1b) in the IgG format induced antibody-dependent cell-mediated cytotoxicity and complement-dependent-cytotoxicity in GPC3-positive cancer cells. The hYP7 antibody was tested and showed inhibition of HCC xenograft tumor growth in nude mice. This study successfully humanizes and validates high affinity anti-GPC3 antibodies and sets a foundation for future development of these antibodies in various clinical formats in the treatment of liver cancer. PMID:27667400

  20. THE STUDY OF PRODUCTION AND MECHANISM OF ANTIPHOSPHOLIPID ANTIBODIES IN PATIENTS WITH CORONARY HEART DISEASE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To assess whether there was strong association between antiphospholipid antibodies(APA) and coronary heart disease(CHD), to study the environmental factors of APA production and APA pathogenic mechanism in patients with CHD.Methods Blood samples from 76 patients with CHD and 30 controls were tested for anticardiolipin antibodies IgG(ACA-IgG),human cytomegalovirus IgG,IgM(HCMV-IgG,IgM) by enzyme-link immunosorbant assay(ELISA) and 6-keto-PGF1a,endothelin(ET) by radioimmunoassay(RIA).Results A total of 27 patients(35.53%) were ACA positive in 76, as compared to 2 of 30(6.67%) healthy individuals, P<0.05. There was no difference in ACA among acute myocardial infarction(AMI,39.13%), old myocardial infarction(OMI,26.53%), unstable angina pectoris(UA,38.40%), P>0.05. The number of ACA positive subjects was higher in HCMV infection patients with CHD than no HCMV infectious patients with CHD. There was no PGI2 and ET level difference between ACA-IgG positive and negative CHD.Conclusion There are strong association between APA and CHD. The HCMV infection may be an environmental factor of APA production in CHD patients with raised ACA. The alteration of PGI2 and ET are not the pathogenic mechanism of ACA in patients with CHD.

  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. A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words.

    Science.gov (United States)

    Mirick, G R; Bradt, B M; Denardo, S J; Denardo, G L

    2004-12-01

    The United States Food and Drug Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ((90)yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ((131)I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) anti-CD20 MAbs for use in radioimmunotherapy (RIT) of non-Hodgkin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, assays were developed to determine HAGA (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to ''humanize'' MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades.

  3. Human lymphocyte markers defined by antibodies derived from somatic cell hybrids. II. A hybridoma secreting antibody against an antigen expressed by human B and null lymphocytes.

    Science.gov (United States)

    Beckman, I G; Bradley, J; Brooks, D A; Kupa, A; McNamara, P J; Thomas, M E; Zola, H

    1980-06-01

    A hybridoma (FMC4) has been derived which secretes antibody showing selective reaction with human B lymphocytes, monocytes and some null lymphocytes. Few, if any, T lymphocytes in normal blood are stained, although stimulation of lymphocytes with PHA leads to an increase in the proportion of cells reacting with the hybridoma antibody. The antibody reacts with B and null lymphoblastoid cell lines but not with T cell lines. B chronic lymphocytic leukaemia (CLL) cells but not T-CLLs are stained and null-type acute lymphoblastic leukaemia (ALL) cells but not T-type ALL also react. Normal blood myeloid cells do not react with FMC4 supernatant whilst some myeloid leukaemias do. The expression of the antigen reacting with FMC4 supernatant suggests that FMC4 may secrete an antibody against the human equivalent of the Ia antigen.

  4. Antibodies against Hepatitis A and Hepatitis B Virus in Intravenous Immunoglobulin Products.

    Science.gov (United States)

    Lee, Soyoung; Kim, Han Wool; Kim, Kyung Hyo

    2016-12-01

    The worldwide seroprevalence of hepatitis A virus (HAV) and hepatitis B virus (HBV) has changed over the last two decades, indicating a declining incidence of HAV and HBV infections. Therefore, vaccinations against HAV and HBV are recommended for unimmunized people before traveling to an endemic area. Unfortunately, primary antibody deficiency (PAD) patients can only obtain humoral immunity through intravenous immunoglobulin G (IVIG) replacement and not from vaccination because of a defect in antibody production. However, few studies have analyzed the titers of antibodies against HAV or HBV in IVIG products. In this study, the titers of anti-HAV and anti-HBs antibodies were measured in nineteen lots of IVIG products from five manufacturers from three countries (A, B from Korea; C, D from Japan; and E from the USA), and trough titers in plasma were estimated. Concentrations of anti-HAV antibody ranged from 1,888-8,927 mIU/mL and estimated trough titers exceeded the minimal protective value in all evaluated IVIG products. Concentrations of anti-HBs antibody ranged from 438-965 mIU/mL in products A and B and were 157, 123, and 1,945 mIU/mL in products C, D, and E, respectively. Estimated trough titers in products A, B, and E exceeded the minimal protective value but those in products C and D did not reach this threshold. These data demonstrated that available IVIG products generally provide sufficient antibodies against HAV and HBV to protect patients with PAD, although the trough concentrations of anti-HBs antibody in two IVIG products did not reach the minimum protective value.

  5. 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.

  6. A human monoclonal antibody to high-frequency red cell antigen Jra.

    Science.gov (United States)

    Miyazaki, T; Kwon, K W; Yamamoto, K; Tone, Y; Ihara, H; Kato, T; Ikeda, H; Sekiguchi, S

    1994-01-01

    A human-mouse heterohybridoma (HMR0921) secreting human monoclonal IgG3, lambda antibody was produced from peripheral blood lymphocytes of a healthy blood donor with serum antibody to Jra, by EBV transformation and hybridization with mouse myeloma cell line P3X63Ag8.653. The reactivity of HMR0921 antibody was assessed by antiglobulin test with a panel of red cells including 14 different rare blood types. Only Jr(a-) red cells were negative. The strict specificity of this antibody to Jra antigen was further confirmed by absorption test with fluorescence flow cytometry. On screening of 28,744 blood donor samples by HMR0921 antibody, we detected 19 agglutination-negative samples, which were confirmed as Jr(a-) by conventional anti-Jra antisera. Therefore, our HMR0921 antibody is extremely useful for detecting rare Jr(a-) blood.

  7. Changes in antibody profile after treatment of human onchocerciasis.

    Science.gov (United States)

    Lee, S J; Francis, H L; Awadzi, K; Ottesen, E A; Nutman, T B

    1990-08-01

    To define the changes in antibody response to Onchocerca volvulus antigens after treatment of patients with onchocerciasis, IgG and IgE antibodies were examined quantitatively and qualitatively in 21 patients and 3 control individuals before and sequentially for 14 days after treatment with diethylcarbamazine. The quantitative levels of IgE and IgG responses (both polyclonal and O. volvulus-specific) remained essentially unchanged for all patients, but 9 of the 21 patients showed intensified responses to one or more parasite-specific antigens, and 8 of 21 developed antibodies to previously undetected antigens. There was a significant correlation between the intensities of infection and the development of newly recognized anti-O. volvulus antibodies. These studies demonstrate that O. volvulus-specific IgE and IgG antibody responses are, at least transiently, enhanced by treatment with diethylcarbamazine and that after treatment, parasites possibly release antigens previously hidden from the host's immune response.

  8. Selection of apoptotic cell specific human antibodies from adult bone marrow.

    Directory of Open Access Journals (Sweden)

    Caroline Grönwall

    Full Text Available Autoreactive antibodies that recognize neo-determinants on apoptotic cells in mice have been proposed to have protective, homeostatic and immunoregulatory properties, although our knowledge about the equivalent antibodies in humans has been much more limited. In the current study, human monoclonal antibodies with binding specificity for apoptotic cells were isolated from the bone marrow of healthy adults using phage display technology. These antibodies were shown to recognize phosphorylcholine (PC-associated neo-determinants. Interestingly, three of the four identified apoptotic cell-specific antibody clones were encoded by VH3 region rearrangements with germline or nearly germline configuration without evidence of somatic hypermutation. Importantly, the different identified antibody clones had diverse heavy chain CDR3 and deduced binding surfaces as suggested by structure modeling. This may suggest a potentially great heterogeneity in human antibodies recognizing PC-related epitopes on apoptotic cells. To re-construct the postulated structural format of the parental anti-PC antibody, the dominant clone was also expressed as a recombinant human polymeric IgM, which revealed a substantially increased binding reactivity, with dose-dependent and antigen-inhibitable binding of apoptotic cells. Our findings may have implication for improved prognostic testing and therapeutic interventions in human inflammatory disease.

  9. Discovery and Characterization of Phage Display-Derived Human Monoclonal Antibodies against RSV F Glycoprotein.

    Directory of Open Access Journals (Sweden)

    Zhifeng Chen

    Full Text Available Respiratory syncytial virus (RSV is a leading cause of lower respiratory tract infection in infants, the elderly and in immunosuppressed populations. The vast majority of neutralizing antibodies isolated from human subjects target the RSV fusion (F glycoprotein, making it an attractive target for the development of vaccines and therapeutic antibodies. Currently, Synagis® (palivizumab is the only FDA approved antibody drug for the prevention of RSV infection, and there is a great need for more effective vaccines and therapeutics. Phage display is a powerful tool in antibody discovery with the advantage that it does not require samples from immunized subjects. In this study, Morphosys HuCAL GOLD® phage libraries were used for panning against RSV prefusion and postfusion F proteins. Panels of human monoclonal antibodies (mAbs against RSV F protein were discovered following phage library panning and characterized. Antibodies binding specifically to prefusion or postfusion F proteins and those binding both conformations were identified. 3B1 is a prototypic postfusion F specific antibody while 2E1 is a prototypic prefusion F specific antibody. 2E1 is a potent broadly neutralizing antibody against both RSV A and B strains. Epitope mapping experiments identified a conformational epitope spanning across three discontinuous sections of the RSV F protein, as well as critical residues for antibody interaction.

  10. Optimizing selection of large animals for antibody production by screening immune response to standard vaccines.

    Science.gov (United States)

    Thompson, Mary K; Fridy, Peter C; Keegan, Sarah; Chait, Brian T; Fenyö, David; Rout, Michael P

    2016-03-01

    Antibodies made in large animals are integral to many biomedical research endeavors. Domesticated herd animals like goats, sheep, donkeys, horses and camelids all offer distinct advantages in antibody production. However, their cost of use is often prohibitive, especially where poor antigen response is commonplace; choosing a non-responsive animal can set a research program back or even prevent experiments from moving forward entirely. Over the course of production of antibodies from llamas, we found that some animals consistently produced a higher humoral antibody response than others, even to highly divergent antigens, as well as to their standard vaccines. Based on our initial data, we propose that these "high level responders" could be pre-selected by checking antibody titers against common vaccines given to domestic farm animals. Thus, time and money can be saved by reducing the chances of getting poor responding animals and minimizing the use of superfluous animals.

  11. Serological analysis of human anti-human antibody responses in colon cancer patients treated with repeated doses of humanized monoclonal antibody A33.

    Science.gov (United States)

    Ritter, G; Cohen, L S; Williams, C; Richards, E C; Old, L J; Welt, S

    2001-09-15

    Mouse monoclonal antibody A33 (mAb A33) recognizes a M(r) 43,000 cell surface glycoprotein (designated A33) expressed in human colonic epithelium and colon cancer but absent from most other normal tissues. In patients, mAb A33 localizes with high specificity to colon cancer and is retained for up to 6 weeks in the cancer but cleared rapidly from normal colon (5-6 days). As a carrier of (125)I or (131)I, mAb A33 has shown antitumor activity. Induction of strong human anti-mouse antibody (immunoglobulin; HAMA) responses in patients, however, limits the use of the murine mAb A33 to very few injections. A humanized version of this antibody (huAb A33) has been prepared for Phase I and II clinical studies in patients with colon cancer. In those studies, immunogenicity of huAb A33 has been monitored using a novel, highly sensitive BIACORE method, which allows measurement of human anti-human antibodies (HAHAs) without the use of secondary reagents. We found that 63% (26 of 41) of the patients treated with repeated doses of huAb A33 developed HAHAs against a conformational antigenic determinant located in the V(L) and V(H) regions of huAb A33. Detailed serological analysis showed two distinct types of HAHAs. HAHA of type I (49% of patients) was characterized by an early onset with peak HAHA levels after 2 weeks of treatment, which declined with ongoing huAb A33 treatment. HAHA of type II (17% of patients) was characterized by a typically later onset of HAHA than in type I and by progressively increasing HAHA levels with each subsequent huAb A33 administration. Colon cancer patients with type I HAHAs did not develop infusion-related adverse events. In contrast, HAHA of type II was indicative of infusion-related adverse events. By using this new method, we were able to distinguish these two types of HAHAs in patients while on antibody treatment, allowing patients to be removed from study prior to the onset of severe infusion-related adverse events.

  12. Prebiotic and antimicrobials on performance, carcass characteristics, and antibody production in broilers

    National Research Council Canada - National Science Library

    Fomentini, Maíra; Haese, Douglas; Kill, João Luís; Sobreiro, Rodrigo Pereira; Puppo, Débora Del; Haddade, Ismail Ramalho; Lima, Anderson Lazarini; Saraiva, Alysson

    2016-01-01

    To evaluate the effect of supplementation with mannan oligosaccharides, avilamycin and halquinol, alone or in combination, on the performance, carcass characteristics and antibody production in broilers (1-49 days old...

  13. Production and potential use of monoclonal antibodies against polio viruses.

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert); A.L. van Wezel; G. van Steenis (Bert); A.G. Hazendonk

    1982-01-01

    textabstractLymphocyte hybridomas secreting monoclonal antibodies against different strains of polio virus type 1, 2, or 3 have been produced. For this purpose Balb/C mice were immunized with purified and inactivated virus suspensions and their splenocytes were fused with P3X63Ag8 mouse myeloma cell

  14. Fed-batch CHO cell culture for lab-scale antibody production

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Ley, Daniel; Andersen, Mikael Rørdam

    2016-01-01

    Fed-batch culture is the most commonly used upstream process in industry today for recombinant monoclonal antibody production using Chinese hamster ovary cells. Developing and optimizing this process in the lab is crucial for establishing process knowledge, which enable rapid and predictable tech......-transfer to manufacturing scale. In this chapter, we will describe stepwise how to carry out fed-batch CHO cell culture for lab-scale antibody production....

  15. 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.

  16. Urine antibody against human cancer antigen NY-ESO-1

    OpenAIRE

    Jäger, Dirk; Stockert, Elisabeth; Karbach, Julia; Herrlinger, Kristina; Atmaca, Akin; Arand, Michael; Chen, Yao-Tseng; Gnjatic, Sacha; Old, Lloyd J.; Knuth, Alexander; Jäger, Elke

    2002-01-01

    NY-ESO-1 is one of the most immunogenic tumor antigens known to date. Spontaneous humoral and cellular immune responses against NY-ESO-1 are detected in a substantial proportion of patients with NY-ESO-1 positive cancers. NY-ESO-1 serum antibody is dependent on the presence of NY-ESO-1+ cancer cells, and antibody titers correlate with the clinical development of the disease. NY-ESO-1 serum antibody is associated with detectable NY-ESO-1-specific CD8+ T cell reactivity. High titers of NY-ESO-1...

  17. An engineered diatom acting like a plasma cell secreting human IgG antibodies with high efficiency

    Directory of Open Access Journals (Sweden)

    Hempel Franziska

    2012-09-01

    Full Text Available Abstract Background Although there are many different expression systems for recombinant production of pharmaceutical proteins, many of these suffer from drawbacks such as yield, cost, complexity of purification, and possible contamination with human pathogens. Microalgae have enormous potential for diverse biotechnological applications and currently attract much attention in the biofuel sector. Still underestimated, though, is the idea of using microalgae as solar-fueled expression system for the production of recombinant proteins. Results In this study, we show for the first time that completely assembled and functional human IgG antibodies can not only be expressed to high levels in algal systems, but also secreted very efficiently into the culture medium. We engineered the diatom Phaeodactylum tricornutum to synthesize and secrete a human IgG antibody against the Hepatitis B Virus surface protein. As the diatom P. tricornutum is not known to naturally secrete many endogenous proteins, the secreted antibodies are already very pure making extensive purification steps redundant and production extremely cost efficient. Conclusions Microalgae combine rapid growth rates with all the advantages of eukaryotic expression systems, and offer great potential for solar-powered, low cost production of pharmaceutical proteins.

  18. Isolation of Human Antibodies Against Hepatitis E From Phage Display Library by Metal Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To isolate human antibodies against hepatitis E virus from phage display library by a new method of panning phage antibody library based on immobilized metal affinity chromatography (IMAC). Methods Phage antibody library was allowed to mix with hex-His tagged expressed HEV specific antigen, NE2, in solution for adequate binding before affinity resin for hex-His was added. The non-specific phage antibodies were removed by extensive washing and the specific bound phage antibodies could then be eluted to infect TG1 or repeat the binding process for subsequent rounds of purification. The specificity of the selected human antibodies were tested by antigen competitive ELISA, human sera blocking ELISA, scFv expression, and sequence analysis. Results His-NE2 specific recombinant phages were successfully enriched after panning procedure. Two individual phage clones, 126 and 138, showed 50% inhibition in NE2 antigen competition ELISA and obvious blocking effect by HEV positive serum in blocking ELISA. Soluble scFv of 126, 138 bound to NE2 specifically. Conclusion Two specific human phage antibodies against hepatitis E virus (HEV) from phage display library were isolated by immobilized metal affinity chromatography. The immobilized metal affinity chromatography applied to phage antibody selection was a helpful supplement to the selection in solution.

  19. Human monoclonal HLA antibodies reveal interspecies crossreactive swine MHC class I epitopes relevant for xenotransplantation.

    NARCIS (Netherlands)

    Mulder, A.; Kardol, M.J.; Arn, J.S.; Eijsink, C.; Franke, M.E.; Schreuder, G.M.; Haasnoot, G.W.; Doxiadis, I.I.; Sachs, D.H.; Smith, D.M.; Claas, F.H.

    2010-01-01

    Crossreactivity of anti-HLA antibodies with SLA alleles may limit the use of pig xenografts in some highly sensitized patients. An understanding of the molecular basis for this crossreactivity may allow better selection of xenograft donors. We have tested 68 human monoclonal HLA class I antibodies (

  20. Specificity of antibodies to nitric oxide synthase isoforms in human, guinea pig, rat, and mouse tissues

    NARCIS (Netherlands)

    Coers, W; Timens, W; Kempinga, C; Klok, PA; Moshage, H

    1998-01-01

    Ten commercially available rabbit polyclonal anti-NOS antibodies were tested for their immunohistological applicability in normal human, guinea pig, rat, and mouse organs. Most antibodies reacted as expected and described in the literature with various tissues of the investigated species. Several an

  1. Human single chain antibodies against heparin: selection, characterization, and effect on coagulation.

    NARCIS (Netherlands)

    Westerlo, E.M.A. van de; Smetsers, T.F.; Dennissen, M.A.B.A.; Linhardt, R.J.; Veerkamp, J.H.; Muijen, G.N.P. van; Kuppevelt, A.H.M.S.M. van

    2002-01-01

    Heparin, located in mast cells and basophilic granulocytes, is widely used as an anticoagulant. It belongs to a class of linear polysaccharides called glycosaminoglycans (GAGs). Using phage display technology, we have selected 19 unique human antiheparin antibodies. Some antibodies react almost excl

  2. Process performance and product quality in an integrated continuous antibody production process.

    Science.gov (United States)

    Karst, Daniel J; Steinebach, Fabian; Soos, Miroslav; Morbidelli, Massimo

    2017-02-01

    Continuous manufacturing is currently being seriously considered in the biopharmaceutical industry as the possible new paradigm for producing therapeutic proteins, due to production cost and product quality related benefits. In this study, a monoclonal antibody producing CHO cell line was cultured in perfusion mode and connected to a continuous affinity capture step. The reliable and stable integration of the two systems was enabled by suitable control loops, regulating the continuous volumetric flow and adapting the operating conditions of the capture process. For the latter, an at-line HPLC measurement of the harvest concentration subsequent to the bioreactor was combined with a mechanistic model of the capture chromatographic unit. Thereby, optimal buffer consumption and productivity throughout the process was realized while always maintaining a yield above the target value of 99%. Stable operation was achieved at three consecutive viable cell density set points (20, 60, and 40 × 10(6) cells/mL), together with consistent product quality in terms of aggregates, fragments, charge isoforms, and N-linked glycosylation. In addition, different values for these product quality attributes such as N-linked glycosylation, charge variants, and aggregate content were measured at the different steady states. As expected, the amount of released DNA and HCP was significantly reduced by the capture step for all considered upstream operating conditions. This study is exemplary for the potential of enhancing product quality control and modulation by integrated continuous manufacturing. Biotechnol. Bioeng. 2017;114: 298-307. © 2016 Wiley Periodicals, Inc.

  3. Structure of a human monoclonal antibody Fab fragment against gp41 of human immunodeficiency virus type

    Science.gov (United States)

    He, X. M.; Ruker, F.; Casale, E.; Carter, D. C.

    1992-01-01

    The three-dimensional structure of a human monoclonal antibody (Fab), which binds specifically to a major epitope of the transmembrane protein gp41 of the human immunodeficiency virus type 1, has been determined by crystallographic methods to a resolution of 2.7 A. It has been previously determined that this antibody recognizes the epitope SGKLICTTAVPWNAS, belongs to the subclass IgG1 (kappa), and exhibits antibody-dependent cellular cytotoxicity. The quaternary structure of the Fab is in an extended conformation with an elbow bend angle between the constant and variable domains of 175 degrees. Structurally, four of the hypervariable loops can be classified according to previously recognized canonical structures. The third hypervariable loops of the heavy (H3) and light chain (L3) are structurally distinct. Hypervariable loop H3, residues 102H-109H, is unusually extended from the surface. The complementarity-determining region forms a hydrophobic binding pocket that is created primarily from hypervariable loops L3, H3, and H2.

  4. Screening of Human Antibody Fab Fragment against HBsAg and the Construction of its dsFv Form

    Directory of Open Access Journals (Sweden)

    Leili Jia, Jiyun Yu, Hongbin Song, Xuelin Liu, Weina Ma, Yuanyong Xu, Chuanfu Zhang, Shicun Dong, Qiao Li

    2008-01-01

    Full Text Available The objective of this study was to pursue the techniques involving the screening of the human antibody Fab fragment against hepatitis B virus surface antigen (HBsAg and the construction of its disulfide-stabilized Fv fragment (dsFv. The phage antibody Fab fragments against HBsAg were screened from the human combinatorial immunoglobulin library. Sequence analysis revealed that its heavy chain gene was complete, but the light chain gene was lost. To improve the affinity of the antibody by chain shuffling, a human antibody light chain gene repertoire was generated by reverse transcriptase-polymerase chain reaction (RT-PCR from the human peripheral blood lymphocytes. A phage antibody sub-library was then constructed by inserting the light chain gene repertoire into the phagmid that contained the Fd gene. Five clones with appreciably higher absorbance than that of the original clone were obtained, which indicated that the affinity of the light chain-shuffled phage antibodies was improved. Then, the mutated genes of dsFv against HBsAg were constructed by using PCR-based point mutagenesis method. Purified VH and VL proteins were folded into a 25-kDa protein, designated as anti-HBsAg dsFv. ELISA and competition ELISA revealed that the dsFv maintained the specificity of the Fab by binding to HBsAg, even through with a lower binding activity. These results have facilitated the undertaking of further functional analyses of the constructed dsFv, and may therefore provide an improved technique for the production and application of dsFvs against HBsAg.

  5. 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

    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...

  6. Non-covalent carriage of anticancer agents by humanized antibody trastuzumab.

    Science.gov (United States)

    Yadav, Arpita; Sharma, Sweta; Yadav, Veejendra Kumar

    2016-05-01

    This article explores the internalization and non-covalent carriage of small molecule anticancer agents like vinca alkaloids by humanized monoclonal antibody trastuzumab. Such carriage is marked by significant reduction in side effects and increased therapeutic value of these anticancer agents. This study is coherent with few clinical observations of enhanced efficiency of these anticancer agents when co-administered with therapeutic antibodies. This study will also serve as the foundation for screening a database of anticancer agents for possible compounds that may be co-delivered alongwith the antibody. Based on this study vincristine conformation inside antibody and its charge environment may be used as descriptors for screening purposes.

  7. Rapid transient production in plants by replicating and non-replicating vectors yields high quality functional anti-HIV antibody

    National Research Council Canada - National Science Library

    Sainsbury, Frank; Sack, Markus; Stadlmann, Johannes; Quendler, Heribert; Fischer, Rainer; Lomonossoff, George P

    2010-01-01

    .... To assess the quality of antibodies transiently expressed to high levels in plants, we have expressed and characterised the human anti-HIV monoclonal antibody, 2G12, using both replicating and non...

  8. A Spectrum of Monoclonal Antibodies Reactive with Human Mammary Tumor Cells

    Science.gov (United States)

    Colcher, D.; Horan Hand, P.; Nuti, M.; Schlom, J.

    1981-05-01

    Splenic lymphocytes of mice, immunized with membrane-enriched fractions of metastatic human mammary carcinoma tissues, were fused with the NS-1 non-immunoglobulin-secreting murine myeloma cell line. This resulted in the generation of hybridoma cultures secreting immunoglobulins reactive in solid-phase radioimmunoassays with extracts of metastatic mammary carcinoma cells from involved livers, but not with extracts of apparently normal human liver. As a result of further screening of immunoglobulin reactivities and double cloning of cultures, 11 monoclonal antibodies were chosen that demonstrated reactivities with human mammary tumor cells and not with apparently normal human tissues. These monoclonal antibodies could be placed into at least five major groups on the basis of their differential binding to the surface of various live human mammary tumor cells in culture, to extracts of mammary tumor tissues, or to tissue sections of mammary tumor cells studied by the immunoperoxidase technique. Whereas a spectrum of reactivities to mammary tumors was observed with the 11 monoclonal antibodies, no reactivity was observed to apparently normal cells of the following human tissues: breast, lymph node, lung, skin, testis, kidney, thymus, bone marrow, spleen, uterus, thyroid, intestine, liver, bladder, tonsils, stomach, prostate, and salivary gland. Several of the antibodies also demonstrated a ``pancarcinoma'' reactivity, showing binding to selected non-breast carcinomas. None of the monoclonal antibodies showed binding to purified ferritin or carcinoembryonic antigen. Monoclonal antibodies of all five major groups, however, demonstrated binding to human metastatic mammary carcinoma cells both in axillary lymph nodes and at distal sites.

  9. Antibody responses to bacteriophage phi X-174 in human subjects exposed to the antarctic winter-over model of spaceflight

    Science.gov (United States)

    Shearer, W. T.; Lugg, D. J.; Rosenblatt, H. M.; Nickolls, P. M.; Sharp, R. M.; Reuben, J. M.; Ochs, H. D.

    2001-01-01

    BACKGROUND: It has been proposed that exposure to long-term spaceflight conditions (stress, isolation, sleep disruption, containment, microbial contamination, and solar radiation) or to ground-based models of spaceflight will alter human immune responses, but specific antibody responses have not been fully evaluated. OBJECTIVE: We sought to determine whether exposure to the 8-month Antarctic winter-over model of spaceflight would alter human antibody responses. METHODS: During the 1999 Australian National Antarctic Research Expeditions, 11 adult study subjects at Casey, Antarctica, and 7 control subjects at Macquarie Island, sub-Antarctica, received primary and secondary immunizations with the T cell-dependent neoantigen bacteriophage phi X-174. Periodic plasma samples were analyzed for specific antibody function. RESULTS: All of the subjects from Casey, Antarctica, cleared bacteriophage phi X-174 normally by 1 week after primary immunization, and all had normal primary and secondary antibody responses, including immunologic memory amplification and switch from IgM to IgG antibody production. One subject showed a high normal pattern, and one subject had a low normal pattern. The control subjects from Macquarie Island also had normal immune responses to bacteriophage phi X-174. CONCLUSIONS: These data do not support the hypothesis that de novo specific antibody responses of subjects become defective during the conditions of the Antarctic winter-over. Because the Antarctic winter-over model of spaceflight lacks the important factors of microgravity and solar radiation, caution must be used in interpreting these data to anticipate normal antibody responses in long-term spaceflight.

  10. Generation of human scFvs antibodies recognizing a prion protein epitope expressed on the surface of human lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Imperiale Valentina

    2007-07-01

    Full Text Available Abstract Background A hallmark of prion disease is the transformation of normal cellular prion protein (PrPc into an infectious disease-associated isoform, (PrPsc. Anti-prion protein monoclonal antibodies are invaluable for structure-function studies of PrP molecules. Furthermore recent in vitro and in vivo studies indicate that anti-PrP monoclonal antibodies can prevent the incorporation of PrPc into propagating prions. In the present article, we show two new human phage antibodies, isolated on recombinant hamster prion protein (rHaPrP. Results We adopted an antibody phage display strategy to isolate specific human antibodies directed towards rHaPrP which has been used as a bait for panning the synthetic ETH-2 antibody phage library. Two phage antibodies clones named MA3.B4 and MA3.G3 were isolated and characterized under genetic biochemical and immunocytochemical aspects. The clones were found to recognize the prion protein in ELISA studies. In flow-cytometry studies, these human single chain Fragment variable (scFv phage-antibodies show a well defined pattern of reactivity on human lymphoblastoid and myeloid cells. Conclusion Sequence analysis of the gene encoding for the antibody fragments and antigen recognition patterns determined by flow-cytometry analysis indicate that the isolated scFvs recognize novel epitopes in the PrPc molecule. These new anti PrPc human antibodies are unique reagents for prion protein detection and may represent a biologic platform to develop new reagents to treat PrPsc associated disease.

  11. HIV therapy by a combination of broadly neutralizing antibodies in humanized mice

    Science.gov (United States)

    Klein, Florian; Gruell, Henning; Scheid, Johannes F.; Bournazos, Stylianos; Mouquet, Hugo; Spatz, Linda A.; Diskin, Ron; Abadir, Alexander; Zang, Trinity; Dorner, Marcus; Billerbeck, Eva; Labitt, Rachael N.; Gaebler, Christian; Marcovecchio, Paola; Incesu, Reha-Baris; Eisenreich, Thomas R.; Bieniasz, Paul D.; Seaman, Michael S.; Bjorkman, Pamela J.; Ravetch, Jeffrey V.; Ploss, Alexander; Nussenzweig, Michel C.

    2013-01-01

    Summary Human antibodies to HIV-1 can neutralize a broad range of viral isolates in vitro and protect non-human primates against infection1,2. Previous work showed that antibodies exert selective pressure on the virus but escape variants emerge within a short period of time3,4. However, these experiments were performed before the recent discovery of more potent anti-HIV-1 antibodies and their improvement by structure-based design5-9. Here we re-examine passive antibody transfer as a therapeutic modality in HIV-1-infected humanized mice (hu-mice). Although HIV-1 can escape from antibody monotherapy, combinations of broadly neutralizing antibodies (bNAbs) can effectively control HIV-1 infection and suppress viral load to levels below detection. Moreover, in contrast to antiretroviral therapy (ART)10-12, the longer half-life of antibodies led to viremic control for an average of 60 days after cessation of therapy. Thus, combinations of potent monoclonal antibodies can effectively control HIV-1 replication in hu-mice, and should be re-examined as a therapeutic modality in HIV-1-infected individuals. PMID:23103874

  12. A survey for arboviral antibodies in sera of humans and animals in Lombok, Republic of Indonesia.

    Science.gov (United States)

    Olson, J G; Ksiazek, T G; Gubler, D J; Lubis, S I; Simanjuntak, G; Lee, V H; Nalim, S; Juslis, K; See, R

    1983-04-01

    Sera were collected from humans, cattle, horses, goats, ducks, chickens, wild birds, bats and rats in Lombok, Indonesia, and were tested by haemagglutination inhibition (HI) for antibodies to JE, ZIKA, CHIK and RR. Selected sera were tested by microneutralization tests for antibodies to the following viruses: JE, ZIKA, MVE, TMU, LGT, KUN, SEP, DEN-2, CHIK, RR, GET, SIN, BUN, BAT and BAK. Human sera had JE HI antibody in 135 (30%) of 446 tested. Neutralization tests indicated that DEN-2, ZIKA, TMU, KUN and SEP may have caused flavivirus infections. Antibodies to other arboviruses tested for were not found. HI and neutralization tests on animal sera indicated possible flavivirus infections with JE, MVE, KUN and SEP, and also that infections with BAT and BUN had occurred among domestic animals. No neutralizing antibodies were found for alphaviruses or other viruses used in the tests.

  13. Mice with megabase humanization of their immunoglobulin genes generate antibodies as efficiently as normal mice.

    Science.gov (United States)

    Murphy, Andrew J; Macdonald, Lynn E; Stevens, Sean; Karow, Margaret; Dore, Anthony T; Pobursky, Kevin; Huang, Tammy T; Poueymirou, William T; Esau, Lakeisha; Meola, Melissa; Mikulka, Warren; Krueger, Pamela; Fairhurst, Jeanette; Valenzuela, David M; Papadopoulos, Nicholas; Yancopoulos, George D

    2014-04-01

    Mice genetically engineered to be humanized for their Ig genes allow for human antibody responses within a mouse background (HumAb mice), providing a valuable platform for the generation of fully human therapeutic antibodies. Unfortunately, existing HumAb mice do not have fully functional immune systems, perhaps because of the manner in which their genetic humanization was carried out. Heretofore, HumAb mice have been generated by disrupting the endogenous mouse Ig genes and simultaneously introducing human Ig transgenes at a different and random location; KO-plus-transgenic humanization. As we describe in the companion paper, we attempted to make mice that more efficiently use human variable region segments in their humoral responses by precisely replacing 6 Mb of mouse Ig heavy and kappa light variable region germ-line gene segments with their human counterparts while leaving the mouse constant regions intact, using a unique in situ humanization approach. We reasoned the introduced human variable region gene segments would function indistinguishably in their new genetic location, whereas the retained mouse constant regions would allow for optimal interactions and selection of the resulting antibodies within the mouse environment. We show that these mice, termed VelocImmune mice because they were generated using VelociGene technology, efficiently produce human:mouse hybrid antibodies (that are rapidly convertible to fully human antibodies) and have fully functional humoral immune systems indistinguishable from those of WT mice. The efficiency of the VelocImmune approach is confirmed by the rapid progression of 10 different fully human antibodies into human clinical trials.

  14. NOVEL AMYLOID-BETA SPECIFIC scFv and VH ANTIBODY FRAGMENTS FROM HUMAN AND MOUSE PHAGE DISPLAY ANTIBODY LIBRARIES

    Science.gov (United States)

    Medecigo, M.; Manoutcharian, K.; Vasilevko, V.; Govezensky, T.; Munguia, M. E.; Becerril, B.; Luz-Madrigal, A.; Vaca, L.; Cribbs, D. H.; Gevorkian, G.

    2010-01-01

    Anti-amyloid immunotherapy has been proposed as an appropriate therapeutic approach for Alzheimer’s disease (AD). Significant efforts have been made towards the generation and assessment of antibody-based reagents capable of preventing and clearing amyloid aggregates as well as preventing their synaptotoxic effects. In this study, we selected a novel set of human anti-amyloid-beta peptide 1-42 (Aβ1-42) recombinant monoclonal antibodies in a single chain fragment variable (scFv) and a single domain (VH) formats. We demonstrated that these antibody fragments recognize in a specific manner amyloid beta deposits in APP/Tg mouse brains, inhibit toxicity of oligomeric Aβ1-42 in neuroblastoma cell cultures in a concentration-dependently manner and reduced amyloid deposits in APP/Tg2576 mice after intracranial administration. These antibody fragments recognize epitopes in the middle/C-terminus region of Aβ, which makes them strong therapeutic candidates due to the fact that most of the Aβ species found in the brains of AD patients display extensive N-terminus truncations/modifications. PMID:20451261

  15. Economics of recombinant antibody production processes at various scales: Industry-standard compared to continuous precipitation.

    Science.gov (United States)

    Hammerschmidt, Nikolaus; Tscheliessnig, Anne; Sommer, Ralf; Helk, Bernhard; Jungbauer, Alois

    2014-06-01

    Standard industry processes for recombinant antibody production employ protein A affinity chromatography in combination with other chromatography steps and ultra-/diafiltration. This study compares a generic antibody production process with a recently developed purification process based on a series of selective precipitation steps. The new process makes two of the usual three chromatographic steps obsolete and can be performed in a continuous fashion. Cost of Goods (CoGs) analyses were done for: (i) a generic chromatography-based antibody standard purification; (ii) the continuous precipitation-based purification process coupled to a continuous perfusion production system; and (iii) a hybrid process, coupling the continuous purification process to an upstream batch process. The results of this economic analysis show that the precipitation-based process offers cost reductions at all stages of the life cycle of a therapeutic antibody, (i.e. clinical phase I, II and III, as well as full commercial production). The savings in clinical phase production are largely attributed to the fact that expensive chromatographic resins are omitted. These economic analyses will help to determine the strategies that are best suited for small-scale production in parallel fashion, which is of importance for antibody production in non-privileged countries and for personalized medicine.

  16. General in vitro method to analyze the interactions of synthetic polymers with human antibody repertoires.

    Science.gov (United States)

    Soshee, Anandakumar; Zürcher, Stefan; Spencer, Nicholas D; Halperin, Avraham; Nizak, Clément

    2014-01-13

    Recent reports on the hitherto underestimated antigenicity of poly(ethylene glycol) (PEG), which is widely used for pharmaceutical applications, highlight the need for efficient testing of polymer antigenicity and for a better understanding of its molecular origins. With this goal in mind, we have used the phage-display technique to screen large, recombinant antibody repertoires of human origin in vitro for antibodies that bind poly(vinylpyrrolidone) (PVP). PVP is a neutral synthetic polymer of industrial and clinical interest that is also a well-known model antigen in animal studies, thus allowing the comparison of in vitro and in vivo responses. We have identified 44 distinct antibodies that bind specifically to PVP. Competitive binding assays show that the PVP-antibody binding constant is proportional to the polymerization degree of PVP and that specific binding is detected down to the vinylpyrrolidone (VP) monomer level. Statistical analysis of anti-PVP antibody sequences identifies an amino-acid motif that is shared by many phage-display-selected anti-PVP antibodies that are similar to a previously described natural anti-PVP antibody. This suggests a role for this motif in specific antibody/PVP interactions. Interestingly, sequence analysis also suggests that only a single antibody chain containing this shared motif is responsible for antibody binding to PVP, as confirmed upon systematic deletion of either antibody chain for 90% of selected anti-PVP antibodies. Overall, a large number of antibodies in the human repertoires we have screened bind specifically to PVP through a small number of shared amino acid motifs, and preliminary comparison points to significant correlations between the sequences of phage-display-selected anti-PVP antibodies and their natural counterparts isolated from immunized mice in previous studies. This study pioneers the use of antibody phage-display to explore the antigenicity of biotechnologically relevant polymers. It also paves the

  17. VH-VL orientation prediction for antibody humanization candidate selection: A case study.

    Science.gov (United States)

    Bujotzek, Alexander; Lipsmeier, Florian; Harris, Seth F; Benz, Jörg; Kuglstatter, Andreas; Georges, Guy

    2016-01-01

    Antibody humanization describes the procedure of grafting a non-human antibody's complementarity-determining regions, i.e., the variable loop regions that mediate specific interactions with the antigen, onto a β-sheet framework that is representative of the human variable region germline repertoire, thus reducing the number of potentially antigenic epitopes that might trigger an anti-antibody response. The selection criterion for the so-called acceptor frameworks (one for the heavy and one for the light chain variable region) is traditionally based on sequence similarity. Here, we propose a novel approach that selects acceptor frameworks such that the relative orientation of the 2 variable domains in 3D space, and thereby the geometry of the antigen-binding site, is conserved throughout the process of humanization. The methodology relies on a machine learning-based predictor of antibody variable domain orientation that has recently been shown to improve the quality of antibody homology models. Using data from 3 humanization campaigns, we demonstrate that preselecting humanization variants based on the predicted difference in variable domain orientation with regard to the original antibody leads to subsets of variants with a significant improvement in binding affinity.

  18. Human immune system mice: current potential and limitations for translational research on human antibody responses.

    Science.gov (United States)

    Vuyyuru, Raja; Patton, John; Manser, Tim

    2011-12-01

    It has recently become possible to generate chimeric mice durably engrafted with many components of the human immune system (HIS mice). We have characterized the maturation and function of the B cell compartment of HIS mice. The antibody response of HIS mice to T cell-dependent B cell antigens is limited, and contributing factors may be the general immaturity of the B cell compartment, infrequent helper T cells selected on human MHC class II antigens, and incomplete reconstitution of secondary lymphoid organs and their microenvironments. In contrast, HIS mice generate protective antibody responses to the bacterium Borrelia hermsii, which acts as a T cell-independent antigen in mice, but do not respond to purified polysaccharide antigens (PPS). We speculate that the anti-B. hermsii response of HIS mice is derived from an abundant B cell subset that may be analogous to B1 B cells in mice. We suggest that failure of HIS mice to respond to PPS is due to the lack of a B cell subset that may originate from adult bone marrow and is highly dependent on human interleukin-7 for development.

  19. Large-scale production of monoclonal antibodies in suspension culture.

    Science.gov (United States)

    Backer, M P; Metzger, L S; Slaber, P L; Nevitt, K L; Boder, G B

    1988-10-01

    Monoclonal antibodies are being manufactured for clinical trials in suspension culture at the 1300-L scale. Suspension culture offers some advantages relative to high-density mammalian cell culture methods; in particular, the ability to closely monitor the behavior of cells in a homogeneous environment. Computer control and on-line mass spectrography of exit gases provide instantaneous information about the culture metabolic activity. Air sparging and agitation by marine impeller provide aeration sufficient to maintain a constant dissolved oxygen tension at cell concentrations up to 5.0 x 10(6) cells/mL without causing apparent cell damage.

  20. Time course of antibodies against IgG and type II collagen in adjuvant arthritis. Role of mycobacteria administration in antibody production.

    Science.gov (United States)

    Franch, A; Cassany, S; Castellote, C; Castell, M

    1994-02-01

    The aim of this study was to elucidate, during the time course of adjuvant arthritis, the existence of antibodies directed to IgG (rheumatoid factor-like) and antibodies against type II collagen. In a second study, we also studied the relation between antibody production, arthritic process and mycobacteria administration. We have demonstrated the presence of antibodies to IgG and type II collagen by means of ELISA techniques. This reactivity appeared on day 7 post-induction, decreased later, and increased progressively from day 21 until last day studied (day 56 post-induction). We have also quantified antibodies against a soluble fraction of Mycobacterium butyricum, the inductor of the disease. Anti-mycobacteria antibodies appeared during the first seven days after induction, but from day 14, when systemic inflammation began, their levels suddenly increased. There is a positive correlation between anti-mycobacteria antibody levels and articular swelling. Anti-IgG and anti-collagen antibody production was not directly linked to arthritic process since these antibodies were synthesized when M. butyricum was administered intraperitoneally, which does not induce arthritis. Anti-mycobacteria antibody concentration was higher when arthritis induction by mycobacterial was successful than when it was unsuccessful.

  1. Antibody response to Salmonella typhi lw human Schistosomiasis mansoni

    Directory of Open Access Journals (Sweden)

    Maria Imaculada Muniz-Junqueira

    1996-10-01

    Full Text Available Antibody response to Salmonella typhi O and H antigens was evaluated in 24 individuals with either hepatointestinal or hepatosplenic schistosomiasis mansoni before and after typhoid vaccination, and compared with that of non-infected controls. Before vaccination, Schistosoma-infected patients showed a higher frequency of positive antibody to O antigen and the same frequency to H antigen when compared with that of healthy individuals. However, those with hepatosplenic schistosomiasis showed higher titres of antibody to H antigen than those with hepatointestinal disease or healthy individuals. Infected subjects, particularly those with hepatointestinal disease, showed a decreased response after typhoid vaccine. Tins diminished ability to mount an immune response towards typhoid antigens dining schistosomiasis may interfere ivith the clearance of the bacteria from blood stream and, therefore, play a role in the prolonged survival of salmonella as obsewed in some patients with chronic salmonellosis associated with schistosomiasis.

  2. ASSOCIATION OF TRYPANOSOME INFECTION WITH SPERM ANTIBODIES PRODUCTION IN RED SOKOTO (MARADI GOATS

    Directory of Open Access Journals (Sweden)

    O. FAYEMI

    2006-01-01

    Full Text Available A total of 1021 randomly selected serum samples of adult male goats that had been screened for trypanosome infection were assayed for sperm antibodies using the immunoperoxidase staining technique. The result of the trypanosome screening revealed that 586(57.39% goats were positive for trypanosome infection, while 435(42.61% were negative. The assay for sperm antibodies showed that 482(47.21% animals were positive, while 539(52.79% were negative. In the group that was positive for trypanosome infection, 364(62.12% animals were positive, whereas 222(37.88% were negative for sperm antibodies (P<0.001. The group that was negative for trypanosome infection, had a significantly lower number and proportion 118(27.13% of positive compared to 317(72.87% negative for sperm antibodies. Out of a total 482 goats that were positive for sperm antibodies, a significantly higher number, 364(75.52%, were positive than 118(24.48% that were negative for trypanosome infection (P<0.001. In the group that was found negative for sperm antibodies, a significantly lower proportion, 222(41.19%, was positive compared to 317(58.81% that were negative for trypanosome infection (P<0.001. Seropositivity to sperm antibodies was positively correlated to trypanosome infection (P<0.001. Further work on the pathogenesis of sperm antibody production in trypanosome infection is advocated.

  3. Antibody protection reveals extended epitopes on the human TSH receptor.

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    Rauf Latif

    Full Text Available Stimulating, and some blocking, antibodies to the TSH receptor (TSHR have conformation-dependent epitopes reported to involve primarily the leucine rich repeat region of the ectodomain (LRD. However, successful crystallization of TSHR residues 22-260 has omitted important extracellular non-LRD residues including the hinge region which connects the TSHR ectodomain to the transmembrane domain and which is involved in ligand induced signal transduction. The aim of the present study, therefore, was to determine if TSHR antibodies (TSHR-Abs have non-LRD binding sites outside the LRD. To obtain this information we employed the method of epitope protection in which we first protected TSHR residues 1-412 with intact TSHR antibodies and then enzymatically digested the unprotected residues. Those peptides remaining were subsequently delineated by mass spectrometry. Fourteen out of 23 of the reported stimulating monoclonal TSHR-Ab crystal contact residues were protected by this technique which may reflect the higher binding energies of certain residues detected in this approach. Comparing the protected epitopes of two stimulating TSHR-Abs we found both similarities and differences but both antibodies also contacted the hinge region and the amino terminus of the TSHR following the signal peptide and encompassing cysteine box 1 which has previously been shown to be important for TSH binding and activation. A monoclonal blocking TSHR antibody revealed a similar pattern of binding regions but the residues that it contacted on the LRD were again distinct. These data demonstrated that conformationally dependent TSHR-Abs had epitopes not confined to the LRDs but also incorporated epitopes not revealed in the available crystal structure. Furthermore, the data also indicated that in addition to overlapping contact regions within the LRD, there are unique epitope patterns for each of the antibodies which may contribute to their functional heterogeneity.

  4. The Interplay of Dengue Virus Morphological Diversity and Human Antibodies.

    Science.gov (United States)

    Lok, Shee-Mei

    2016-04-01

    Dengue virus (DENV) infects ∼400 million people annually, and there is no available vaccine or therapeutics. It is not clear why candidate vaccines provide only modest protection. In addition to the presence of four different dengue serotypes, there is also structural heterogeneity in DENV infectious particles, even within a strain. This severely complicates the development of vaccines and therapeutics. The currently known different morphologies of DENV are: immature, partially mature, compact mature, and expanded mature forms of the virus. In this review I describe these forms of the virus, their infectivity, and how antibodies could recognize these morphologies. I also discuss possible vaccine and antibody therapeutic formulations to protect against all morphologies.

  5. REGULATION OF ANTI-SRBC ANTIBODY PRODUCTION BY OPIOIDS AND THEIR MECHANISMS

    Institute of Scientific and Technical Information of China (English)

    王慧琴; 林嘉友; 刘景生

    1995-01-01

    This study focused on the influences of opioids on the generation of antibody againse sheep erythrocyte in vitro.It was found that morphine,a-CAO,DADLE,MENK were able to inhibit the capacity of murine spleen cells to generate antibody and leukotriene C4 and conversely,dynorphin was able to stimulate the capacity of murine spleen cells to generate antibody and leukotriene C4. Morphine,a-CAO,MENK,DA-DLE,dynorphin decreased intracellular cAMP level,increased [Ca2+]i and calmodulin activity.The effects were completely blocked by naloxone,the specific opioid antagonist.Our results showed that opioids regulate the production of antibody in murine spleen cells,and alter intracellular cAMP,[Ca2+]i calmodulin activity,and leukotriene C4 production by way of binding to different receptor types.

  6. Increased levels of IgG antibodies against human HSP60 in patients with spondyloarthritis.

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    Astrid Hjelholt

    Full Text Available Spondyloarthritis (SpA comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA-B27. A triggering bacterial infection has been considered as the cause of SpA, and bacterial heat shock protein (HSP seems to be a strong T cell antigen. Since bacterial and human HSP60, also named HSPD1, are highly homologous, cross-reactivity has been suggested in disease initiation. In this study, levels of antibodies against bacterial and human HSP60 were analysed in SpA patients and healthy controls, and the association between such antibodies and disease severity in relation to HLA-B27 was evaluated.Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA for immunoglobulin (IgG1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella enteritidis and Campylobacter jejuni. Disease severity was assessed by the clinical scorings Bath Ankylosing Spondylitis Disease Activity Index (BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI and Bath Ankylosing Spondylitis Metrology Index (BASMI. Levels of IgG1 and IgG3 antibodies against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27⁺ patients. Only weak correlation between antibodies against bacterial and human HSP60 was seen, and there was no indication of cross-reaction. These results suggest that antibodies against human HSP60 is associated with SpA, however, the theory that antibodies against human HSP60 is a specific part of the aetiology, through cross-reaction to bacterial HSP60, cannot be supported by results from this study. We suggest that the association between elevated levels of antibodies against human HSP60 and disease may reflect a general activation of the immune system and an increased

  7. Antigen nature and complexity influence human antibody light chain usage and specificity.

    Science.gov (United States)

    Smith, Kenneth; Shah, Hemangi; Muther, Jennifer J; Duke, Angie L; Haley, Kathleen; James, Judith A

    2016-05-27

    Human antibodies consist of a heavy chain and one of two possible light chains, kappa (κ) or lambda (λ). Here we tested how these two possible light chains influence the overall antibody response to polysaccharide and protein antigens by measuring light chain usage in human monoclonal antibodies from antibody secreting cells obtained following vaccination with Pneumovax23. Remarkably, we found that individuals displayed restricted light chain usage to certain serotypes and that lambda antibodies have different specificities and modes of cross-reactivity than kappa antibodies. Thus, at both the monoclonal (7 kappa, no lambda) and serum levels (145μg/mL kappa, 2.82μg/mL lambda), antibodies to cell wall polysaccharide were nearly always kappa. The pneumococcal reference serum 007sp was analyzed for light chain usage to 12 pneumococcal serotypes for which it is well characterized. Similar to results at the monoclonal level, certain serotypes tended to favor one of the light chains (14 and 19A, lambda; 6A and 23F, kappa). We also explored differences in light chain usage at the serum level to a variety of antigens. We examined serum antibodies to diphtheria toxin mutant CRM197 and Epstein-Barr virus protein EBNA-1. These responses tended to be kappa dominant (average kappa-to-lambda ratios of 4.52 and 9.72 respectively). Responses to the influenza vaccine were more balanced with kappa-to-lambda ratio averages having slight strain variations: seasonal H1N1, 1.1; H3N2, 0.96; B, 0.91. We conclude that antigens with limited epitopes tend to produce antibodies with restricted light chain usage and that in most individuals, antibodies with lambda light chains have specificities different and complementary to kappa-containing antibodies.

  8. Role of anti-human lymphocyte culture cytotoxic antibodies in recurrent spontaneous pregnancy loss women

    Directory of Open Access Journals (Sweden)

    Shankarkumar Umapathy

    2011-01-01

    Full Text Available Background : Recurrent spontaneous pregnancy (RSA is defined as a sequence of three or more consecutive spontaneous abortions. One of the major causes of RSA is immunological where alloimmune antibodies develop towards human leucocyte antigen (HLA antigens. Earlier research had suggested that anti-HLA antibodies are produced in normal women; studies have been reported that normal pregnant women develop anti-HLA antibodies, mostly after 20-28 weeks of gestation. Aim : To evaluate the role of anti-HLA antibodies in RSA patients Materials and Methods : A total of 80 randomly selected couples with unexplained three or more RSA and control group of 50 normal pregnant women were screened for anti-HLA A and B antibodies. The anti-HLA antibodies were analyzed following the standard two-stage NIH microlymphocytotoxicity assay. Results : In our study group a high frequency of anti-HLA antibodies among women with RSA (26.25% was detected compared to normal pregnant women (8.0%. Most of the sera showed HLA-A and HLA-B antibodies which had high titer, up to a dilution of 1: 4096. Conclusion : This incidence of high anti-HLA antibodies in RSA women during early weeks of gestation may explain the recurrent pregnancy loss.

  9. Monoclonal antibodies against human BAP31 for immunocytochemistry.

    Science.gov (United States)

    Song, Chaojun; Wang, Fuli; Xu, Zhuwei; Hu, Jintao; Tao, Haiqiang; Yang, Angang; Yang, Kun; Jin, Boquan

    2009-06-01

    Human BAP31 is a 28 kDa polytopic integral protein of the ER and part of a large BAP hetero-oligomeric complex that includes the related BAP29 protein and connections to actomyosin. BAP31 interacts with mIgD, cellubrevin, major histocompatibility complex class I, and BCL-2/BCL-X(L), and plays an important role in regulating the egress of these proteins and in apoptosis. Northern blot analyses have revealed BAP31 RNA transcripts in many tissues, including thymus, spleen, brain, kidney, testis, liver, and lung. However, prominent BAP31 protein expression analyzed by immunohistochemistry is restricted to a minority of cells in normal human tissue. Further studies should be made to verify the expression profiles of BAP31 in the protein level. Production of high affinity MAbs suitable for immunohistochemical staining has lagged. Here we generate a set of MAbs that could be used in Western blot, immunoprecipitation, and immunocytochemistry, providing a new powerful tool for investigation of expression profile of BAP31 protein and furthers the study of BAP31 functions.

  10. Structure of a Human Astrovirus Capsid-Antibody Complex and Mechanistic Insights into Virus Neutralization

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanoff, Walter A.; Campos, Jocelyn; Perez, Edmundo I.; Yin, Lu; Alexander, David L.; DuBois, Rebecca M. (UCSC)

    2016-11-02

    ABSTRACT

    Human astroviruses (HAstVs) are a leading cause of viral diarrhea in young children, the immunocompromised, and the elderly. There are no vaccines or antiviral therapies against HAstV disease. Several lines of evidence point to the presence of protective antibodies in healthy adults as a mechanism governing protection against reinfection by HAstV. However, development of anti-HAstV therapies is hampered by the gap in knowledge of protective antibody epitopes on the HAstV capsid surface. Here, we report the structure of the HAstV capsid spike domain bound to the neutralizing monoclonal antibody PL-2. The antibody uses all six complementarity-determining regions to bind to a quaternary epitope on each side of the dimeric capsid spike. We provide evidence that the HAstV capsid spike is a receptor-binding domain and that the antibody neutralizes HAstV by blocking virus attachment to cells. We identify patches of conserved amino acids that overlap the antibody epitope and may comprise a receptor-binding site. Our studies provide a foundation for the development of therapies to prevent and treat HAstV diarrheal disease.

    IMPORTANCEHuman astroviruses (HAstVs) infect nearly every person in the world during childhood and cause diarrhea, vomiting, and fever. Despite the prevalence of this virus, little is known about how antibodies in healthy adults protect them against reinfection. Here, we determined the crystal structure of a complex of the HAstV capsid protein and a virus-neutralizing antibody. We show that the antibody binds to the outermost spike domain of the capsid, and we provide evidence that the antibody blocks virus attachment to human cells. Importantly, our findings suggest that a subunit-based vaccine focusing the immune system on the HAstV capsid spike domain could be effective in protecting children against HAstV disease.

  11. The Fc and not CD4 Receptor Mediates Antibody Enhancement of HIV Infection in Human Cells

    Science.gov (United States)

    Homsy, Jacques; Meyer, Mia; Tateno, Masatoshi; Clarkson, Sarah; Levy, Jay A.

    1989-06-01

    Antibodies that enhance human immunodeficiency virus (HIV) infectivity have been found in the blood of infected individuals and in infected or immunized animals. These findings raise serious concern for the development of a safe vaccine against acquired immunodeficiency syndrome. To address the in vivo relevance and mechanism of this phenomenon, antibody-dependent enhancement of HIV infectivity in peripheral blood macrophages, lymphocytes, and human fibroblastoid cells was studied. Neither Leu3a, a monoclonal antibody directed against the CD4 receptor, nor soluble recombinant CD4 even at high concentrations prevented this enhancement. The addition of monoclonal antibody to the Fc receptor III (anti-FcRIII), but not of antibodies that react with FcRI or FcRII, inhibited HIV type 1 and HIV type 2 enhancement in peripheral blood macrophages. Although enhancement of HIV infection in CD4+ lymphocytes could not be blocked by anti-FcRIII, it was inhibited by the addition of human immunoglobulin G aggregates. The results indicate that the FcRIII receptor on human macrophages and possibly another Fc receptor on human CD4+ lymphocytes mediate antibody-dependent enhancement of HIV infectivity and that this phenomenon proceeds through a mechanism independent of the CD4 protein.

  12. Human combinatorial Fab library yielding specific and functional antibodies against the human fibroblast growth factor receptor 3.

    Science.gov (United States)

    Rauchenberger, Robert; Borges, Eric; Thomassen-Wolf, Elisabeth; Rom, Eran; Adar, Rivka; Yaniv, Yael; Malka, Michael; Chumakov, Irina; Kotzer, Sarit; Resnitzky, Dalia; Knappik, Achim; Reiffert, Silke; Prassler, Josef; Jury, Karin; Waldherr, Dirk; Bauer, Susanne; Kretzschmar, Titus; Yayon, Avner; Rothe, Christine

    2003-10-03

    The human combinatorial antibody library Fab 1 (HuCAL-Fab 1) was generated by transferring the heavy and light chain variable regions from the previously constructed single-chain Fv library (Knappik, A., Ge, L., Honegger, A., Pack, P., Fischer, M., Wellnhofer, G., Hoess, A., Wölle, J., Plückthun, A., and Virnekäs, B. (2000) J. Mol. Biol. 296, 57-86), diversified in both complementarity-determining regions 3 into a novel Fab display vector, yielding 2.1 x 10(10) different antibody fragments. The modularity has been retained in the Fab display and screening plasmids, ensuring rapid conversion into various antibody formats as well as antibody optimization using prebuilt maturation cassettes. HuCAL-Fab 1 was challenged against the human fibroblast growth factor receptor 3, a potential therapeutic antibody target, against which, to the best of our knowledge, no functional antibodies could be generated so far. A unique screening mode was designed utilizing recombinant functional proteins and cell lines differentially expressing fibroblast growth factor receptor isoforms diversified in expression and receptor dependence. Specific Fab fragments with subnanomolar affinities were isolated by selection without any maturation steps as determined by fluorescence flow cytometry. Some of the selected Fab fragments completely inhibit target-mediated cell proliferation, rendering them the first monoclonal antibodies against fibroblast growth factor receptors having significant function blocking activity. This study validates HuCAL-Fab 1 as a valuable source for the generation of target-specific antibodies for therapeutic applications.

  13. Monoclonal antibodies against human granulocytes and myeloid differentiation antigens.

    Science.gov (United States)

    Mannoni, P; Janowska-Wieczorek, A; Turner, A R; McGann, L; Turc, J M

    1982-12-01

    Monoclonal antibodies (MCA) were obtained by immunizing BALB/c mice with 99% pure granulocytes from normal donors or with a whole leukocyte suspension obtained from a chronic myelogenous leukemia (CML) patient, and then fusing the mouse spleen cells with a 315-43 myeloma cell clone. Four MCA were selected and studied using ELISA, immunofluorescence, cytotoxicity assays, and FACS analysis. Antibodies 80H.1, 80H.3, and 80H.5 (from normals) and 81H.1 (from CML) detected antigens expressed on neutrophils. Antibodies 80H.1 and 80H.3 (IgG) also reacted with monocytes but not with other blood cell subsets. Antibodies 80H.5 and 81H.1 (IgM) were cytotoxic and reacted strongly with most of the cells of the neutrophil maturation sequence, i.e., myeloblasts, promyelocytes, myelocytes, and mature granulocytes. Antibodies 80H.5 and 81H.1 also inhibited CFU-GM growth stimulated by leukocyte feeder layers or placental conditioned media, but did not inhibit BFU-E and CFU-E. Antigens recognized by 80H.3, 80H.5, and 81H.1 were expressed both on a proportion of cells from HL.60, KG.1, ML.1, and K562 myeloid cell lines, and on a proportion of blast cells isolated from patients with acute myelogenous leukemia. They were not found on lymphoid cell lines or lymphoid leukemia cells. These MCA recognize either late differentiation antigens expressed on mature neutrophils and monocytes (80H.1 and 80H.3) or early differentiation antigens (80H.5 and 81H.1) specific to the granulocytic lineage. They may be useful for a better definition of those antigens specific to hematopoietic stem cells and their relationship with normal or neoplastic hematopoiesis.

  14. Recombinant human antibody fragment against tetanus toxoid produced by phage display

    Science.gov (United States)

    Neelakantam, B.; Sridevi, N. V.; Shukra, A. M.; Sugumar, P.; Samuel, S.

    2014-01-01

    Phage display technology is a powerful in vitro method for the identification of specific monoclonal antibodies (antibody fragments) to an antigenic target and allows the rapid generation and selection of high affinity, fully human antibodies directed toward any disease target appropriate for antibody therapy. In the present study, we exploited the phage display technology for the selection of an antigen binding fragment (Fabs) toward tetanus toxoid using human naïve phage antibody library constructed from peripheral blood lymphocytes of naïve human donors. The phages displaying Fab were subjected to three rounds of bio-panning with tetanus toxoid as antigen on a solid phase. The high affinity antibody fragments were expressed in HB2151 strain of Escherichia coli and purified by immobilized metal affinity chromatography. The binding activity and specificity of the antibody fragment was established by its reactivity toward tetanus toxoid and non-reactivity toward other related toxins as determined by enzyme-linked immunosorbent assay and immunoblot analysis. The selected Fab fragment forming the antigen-binding complexes with the toxoid in flocculation assay indicates that the Fab may have a potential neutralizing ability toward antigen. PMID:24678405

  15. Administration of nucleoside-modified mRNA encoding broadly neutralizing antibody protects humanized mice from HIV-1 challenge

    Science.gov (United States)

    Pardi, Norbert; Secreto, Anthony J.; Shan, Xiaochuan; Debonera, Fotini; Glover, Joshua; Yi, Yanjie; Muramatsu, Hiromi; Ni, Houping; Mui, Barbara L.; Tam, Ying K.; Shaheen, Farida; Collman, Ronald G.; Karikó, Katalin; Danet-Desnoyers, Gwenn A.; Madden, Thomas D.; Hope, Michael J.; Weissman, Drew

    2017-01-01

    Monoclonal antibodies are one of the fastest growing classes of pharmaceutical products, however, their potential is limited by the high cost of development and manufacturing. Here we present a safe and cost-effective platform for in vivo expression of therapeutic antibodies using nucleoside-modified mRNA. To demonstrate feasibility and protective efficacy, nucleoside-modified mRNAs encoding the light and heavy chains of the broadly neutralizing anti-HIV-1 antibody VRC01 are generated and encapsulated into lipid nanoparticles. Systemic administration of 1.4 mg kg−1 of mRNA into mice results in ∼170 μg ml−1 VRC01 antibody concentrations in the plasma 24 h post injection. Weekly injections of 1 mg kg−1 of mRNA into immunodeficient mice maintain trough VRC01 levels above 40 μg ml−1. Most importantly, the translated antibody from a single injection of VRC01 mRNA protects humanized mice from intravenous HIV-1 challenge, demonstrating that nucleoside-modified mRNA represents a viable delivery platform for passive immunotherapy against HIV-1 with expansion to a variety of diseases. PMID:28251988

  16. Immune antibodies and helminth products drive CXCR2-dependent macrophage-myofibroblast crosstalk to promote intestinal repair.

    Directory of Open Access Journals (Sweden)

    Julia Esser-von Bieren

    2015-03-01

    Full Text Available Helminth parasites can cause considerable damage when migrating through host tissues, thus making rapid tissue repair imperative to prevent bleeding and bacterial dissemination particularly during enteric infection. However, how protective type 2 responses targeted against these tissue-disruptive multicellular parasites might contribute to homeostatic wound healing in the intestine has remained unclear. Here, we observed that mice lacking antibodies (Aid-/- or activating Fc receptors (Fcrg-/- displayed impaired intestinal repair following infection with the murine helminth Heligmosomoides polygyrus bakeri (Hpb, whilst transfer of immune serum could partially restore chemokine production and rescue wound healing in Aid-/- mice. Impaired healing was associated with a reduced expression of CXCR2 ligands (CXCL2/3 by macrophages (MΦ and myofibroblasts (MF within intestinal lesions. Whilst antibodies and helminths together triggered CXCL2 production by MΦ in vitro via surface FcR engagement, chemokine secretion by intestinal MF was elicited by helminths directly via Fcrg-chain/dectin2 signaling. Blockade of CXCR2 during Hpb challenge infection reproduced the delayed wound repair observed in helminth infected Aid-/- and Fcrg-/- mice. Finally, conditioned media from human MΦ stimulated with infective larvae of the helminth Ascaris suum together with immune serum, promoted CXCR2-dependent scratch wound closure by human MF in vitro. Collectively our findings suggest that helminths and antibodies instruct a chemokine driven MΦ-MF crosstalk to promote intestinal repair, a capacity that may be harnessed in clinical settings of impaired wound healing.

  17. Immune antibodies and helminth products drive CXCR2-dependent macrophage-myofibroblast crosstalk to promote intestinal repair.

    Science.gov (United States)

    Esser-von Bieren, Julia; Volpe, Beatrice; Sutherland, Duncan B; Bürgi, Jérôme; Verbeek, J Sjef; Marsland, Benjamin J; Urban, Joseph F; Harris, Nicola L

    2015-03-01

    Helminth parasites can cause considerable damage when migrating through host tissues, thus making rapid tissue repair imperative to prevent bleeding and bacterial dissemination particularly during enteric infection. However, how protective type 2 responses targeted against these tissue-disruptive multicellular parasites might contribute to homeostatic wound healing in the intestine has remained unclear. Here, we observed that mice lacking antibodies (Aid-/-) or activating Fc receptors (Fcrg-/-) displayed impaired intestinal repair following infection with the murine helminth Heligmosomoides polygyrus bakeri (Hpb), whilst transfer of immune serum could partially restore chemokine production and rescue wound healing in Aid-/- mice. Impaired healing was associated with a reduced expression of CXCR2 ligands (CXCL2/3) by macrophages (MΦ) and myofibroblasts (MF) within intestinal lesions. Whilst antibodies and helminths together triggered CXCL2 production by MΦ in vitro via surface FcR engagement, chemokine secretion by intestinal MF was elicited by helminths directly via Fcrg-chain/dectin2 signaling. Blockade of CXCR2 during Hpb challenge infection reproduced the delayed wound repair observed in helminth infected Aid-/- and Fcrg-/- mice. Finally, conditioned media from human MΦ stimulated with infective larvae of the helminth Ascaris suum together with immune serum, promoted CXCR2-dependent scratch wound closure by human MF in vitro. Collectively our findings suggest that helminths and antibodies instruct a chemokine driven MΦ-MF crosstalk to promote intestinal repair, a capacity that may be harnessed in clinical settings of impaired wound healing.

  18. Synthesis and Characterization of Hapten-Protein Conjugates for Antibody Production against Cyanogenic Glycosides.

    Science.gov (United States)

    Bolarinwa, Islamiyat Folashade

    2015-07-01

    Consumption of cyanogenic plants can cause serious health problems for humans. The ability to detect and quantify cyanogenic glycosides, capable of generating cyanide, could contribute to prevention of cyanide poisoning from the consumption of improperly processed cyanogenic plants. Hapten-protein conjugates were synthesized with amygdalin and linamarin by using a novel approach. Polyclonal antibodies were generated by immunizing four New Zealand White rabbits with synthesized amygdalin-bovine serum albumin and linamarin-bovine serum albumin immunogen. This is the first time an antibody was produced against linamarin. Antibody titer curves were obtained from all the four rabbits by using a noncompetitive enzyme-linked immunosorbent assay. High antibody titer was obtained at dilutions greater than 1:50,000 from both immunogens. This new method is an important step forward in preventing ingestion of toxic cyanogenic glycosides.

  19. Chimeric antibody with human constant regions and mouse variable regions directed against carcinoma-associated antigen 17-1A

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L.K.; Curtis, P.; Rakowicz-Szulczynska, E.; Ghrayeb, J.; Chang, N.; Morrison, S.L.; Koprowski, H.

    1987-01-01

    The authors have cloned the genomic DNA fragments encoding the heavy and light chain variable regions of monoclonal antibody 17-1A, and they have inserted them into mammalian expression vectors containing genomic DNA segments encoding human ..gamma..3 and kappa constant regions. The transfer of these expression vectors containing mouse-human chimeric immunoglobulin genes into Sp2/0 mouse myeloma cells resulted in the production of functional IgG that retained the specific binding to the surface antigen 17-1A expressed on colorectal carcinoma cells.

  20. Human single chain antibody to vascular endothelial growth factor:gene cloning, high-level expression, affinity maturation and bioactivity

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using antibody phage display technique,a human single chain antibody to vascular endothelial growth factor (VEGF) has been cloned.The antibody expression reached 45% of the total bacterial proteins.The purification and refolding of the antibody were completed in one step by using gel filtration chromatograph.ELISA analysis showed that the antibody not only specifically bound to human VEGF,but also competitively inhibited VEGF reacting with its receptors.In order to raise the affinity of the single chain antibody,its heavy chain variable region was randomly mutated using error-prone PCR and an antibody mutant library was constructed,from which a mutant with higher affinity was screened out.The three-dimensional structure and binding affinity of wild type and mutant antibody were compared.Our study provided a potential reagent for tumor angiogenic therapy and a significant model for antibody high-level expression and affinity maturation.

  1. Human single chain antibody to vascular endothelial growth factor: gene cloning, high-level expression, affinity maturation and bioactivity

    Institute of Scientific and Technical Information of China (English)

    阎锡蕴[1; 汤健[2; 吴小平[3; 王凤采[4; 李建生[5; 杨东玲[6

    2000-01-01

    Using antibody phage display technique, a human single chain antibody to vascular endothelial growth factor (VEGF) has been cloned. The antibody expression reached 45% of the total bacterial proteins. The purification and refolding of the antibody were completed in one step by using gel filtration chromatograph. ELISA analysis showed that the antibody not only specifically bound to human VEGF, but also competitively inhibited VEGF reacting with its receptors. In order to raise the affinity of the single chain antibody, its heavy chain variable region was randomly mutated using error-prone PCR and an antibody mutant library was constructed, from which a mutant with higher affinity was screened out. The three-dimensional structure and binding affinity of wild type and mutant antibody were compared. Our study provided a potential reagent for tumor angiogenic therapy and a significant model for antibody high-level expression and affinity maturation.

  2. Uptake of antigen-antibody complexes by human dendritic cells.

    Science.gov (United States)

    Fanger, N A; Guyre, P M; Graziano, R F

    2001-01-01

    Fc receptors specific for IgG (FcγR) potentiate the immune response by facilitating the interaction between myeloid cells and antibody-coated targets (1-3). Monocyte and neutrophil FcyR engagement can lead to the induction of lytic-type mechanisms associated with innate responses. FcyR triggering can also play a key role in adaptive immune responses. For example, FcyR-directed capture and uptake of antigens (Ag) by dendritic cells (DC) results in processing and presentation to naive Ag-specific T cells, leading to their expansion and maturation into effector T-cell populations. This chapter describes methodology currently in use to explore and manipulate antigen-antibody (Ag-Ab) uptake by FcyR expressed on DC.

  3. High-level production of a monoclonal antibody in murine myeloma cells by perfusion culture using a gravity settler.

    Science.gov (United States)

    Choo, Chiou-Yu; Tian, Yuan; Kim, Wan-Seop; Blatter, Erich; Conary, Jon; Brady, Ciaran P

    2007-01-01

    A perfusion system is described for the production of a human monoclonal antibody in non-secreting murine myeloma (NS0) cells that was previously shown to be difficult to produce at high levels using fed-batch culture. The perfusion system was based on the use of a commercially available cell settler as the separation device to separate the cells from the culture. Separation efficiency of the cell settler was above 98%. Based on the growth and glucose consumption rates, fresh media was added to the culture and the turnover rate for the bioreactor was set at a maximum of 1.5 times the bioreactor volume per day. The perfusion process resulted in twice the maximum viable cell densities and up to three times the total protein production in a 53-day run period when compared to the fed-batch process. In addition, charge heterogeneity of the antibody as measured by ion exchange chromatography was lower for material purified from the perfusion runs compared to fed-batch. Perfusion mode of culture using a commercially available gravity settler is therefore a viable alternative to fed-batch mode for high-level production of this monoclonal antibody in NS0 cells.

  4. Rapid production of antigen-specific monoclonal antibodies from a variety of animals

    Directory of Open Access Journals (Sweden)

    Kurosawa Nobuyuki

    2012-09-01

    Full Text Available Abstract Background Although a variety of animals have been used to produce polyclonal antibodies against antigens, the production of antigen-specific monoclonal antibodies from animals remains challenging. Results We propose a simple and rapid strategy to produce monoclonal antibodies from a variety of animals. By staining lymph node cells with an antibody against immunoglobulin and a fluorescent dye specific for the endoplasmic reticulum, plasma/plasmablast cells were identified without using a series of antibodies against lineage markers. By using a fluorescently labeled antigen as a tag for a complementary cell surface immunoglobulin, antigen-specific plasma/plasmablast cells were sorted from the rest of the cell population by fluorescence-activated cell sorting. Amplification of cognate pairs of immunoglobulin heavy and light chain genes followed by DNA transfection into 293FT cells resulted in the highly efficient production of antigen-specific monoclonal antibodies from a variety of immunized animals. Conclusions Our technology eliminates the need for both cell propagation and screening processes, offering a significant advantage over hybridoma and display strategies.

  5. Novel method for the high-throughput production of phosphorylation site-specific monoclonal antibodies

    Science.gov (United States)

    Kurosawa, Nobuyuki; Wakata, Yuka; Inobe, Tomonao; Kitamura, Haruki; Yoshioka, Megumi; Matsuzawa, Shun; Kishi, Yoshihiro; Isobe, Masaharu

    2016-01-01

    Threonine phosphorylation accounts for 10% of all phosphorylation sites compared with 0.05% for tyrosine and 90% for serine. Although monoclonal antibody generation for phospho-serine and -tyrosine proteins is progressing, there has been limited success regarding the production of monoclonal antibodies against phospho-threonine proteins. We developed a novel strategy for generating phosphorylation site-specific monoclonal antibodies by cloning immunoglobulin genes from single plasma cells that were fixed, intracellularly stained with fluorescently labeled peptides and sorted without causing RNA degradation. Our high-throughput fluorescence activated cell sorting-based strategy, which targets abundant intracellular immunoglobulin as a tag for fluorescently labeled antigens, greatly increases the sensitivity and specificity of antigen-specific plasma cell isolation, enabling the high-efficiency production of monoclonal antibodies with desired antigen specificity. This approach yielded yet-undescribed guinea pig monoclonal antibodies against threonine 18-phosphorylated p53 and threonine 68-phosphorylated CHK2 with high affinity and specificity. Our method has the potential to allow the generation of monoclonal antibodies against a variety of phosphorylated proteins. PMID:27125496

  6. Agonistic antibodies reveal the function of GPR56 in human glioma U87-MG cells.

    Science.gov (United States)

    Ohta, Shigeyuki; Sakaguchi, Sayaka; Kobayashi, Yuki; Mizuno, Norikazu; Tago, Kenji; Itoh, Hiroshi

    2015-01-01

    GPR56 is a member of the adhesion G protein-coupled receptor (GPCR) and is highly expressed in parts of tumor cells. The involvement of GPR56 in tumorigenesis has been reported. We generated agonistic monoclonal antibodies against human GPR56 and analyzed the action and signaling pathway of GPR56. The antibodies inhibited cell migration through the Gq and Rho pathway in human glioma U87-MG cells. Co-immunoprecipitation analysis indicated that the interaction between the GPR56 extracellular domain and transmembrane domain was potentiated by agonistic antibodies. These results demonstrated that functional antibodies are invaluable tools for GPCR research and should open a new avenue for therapeutic treatment of tumors.

  7. Production of monoclonal antibody for the detection of meat and bone meal in animal feed.

    Science.gov (United States)

    Kim, Shin-Hee; Huang, Tung-Shi; Seymour, Thomas A; Wei, Cheng-i; Kempf, Stephen C; Bridgman, C Roger; Clemens, Roger A; An, Haejung

    2004-12-15

    For the detection of prohibited meat and bone meal (MBM) in animal feed, monoclonal antibodies (MAbs) were raised against heat-stable h-caldesmon purified from bovine intestinal smooth muscle. The obtained hybridoma cells were screened against extracts of the bovine MBM and heat-treated smooth muscle, and MAb 5E12 was identified as having the best performance. Antibody 5E12 did not react with animal feed, milk product, plant proteins, and other ingredients used for commercial animal feed except for the gelatin. This antibody diluted to 100-fold was able to detect MBM mixed in animal feed at 0.05% in an ELISA, and it showed strong affinity toward bovine smooth muscle autoclaved at 130 degrees C. Therefore, this antibody can be used in the ELISA system for field testing of the presence of MBM in animal feed.

  8. Exquisite specificity and peptide epitope recognition promiscuity, properties shared by antibodies from sharks to humans.

    Science.gov (United States)

    Marchalonis, J J; Adelman, M K; Robey, I F; Schluter, S F; Edmundson, A B

    2001-01-01

    This review considers definitions of the specificity of antibodies including the development of recent concepts of recognition polyspecificity and epitope promiscuity. Using sets of homologous and unrelated peptides derived from the sequences of immunoglobulin and T cell receptor chains we offer operational definitions of cross-reactivity by investigating correlations of either identities in amino acid sequence, or in hydrophobicity/hydrophilicity profiles with degree of binding in enzyme-linked immunosorbent assays. Polyreactivity, or polyspecificity, are terms used to denote binding of a monoclonal antibody or purified antibody preparation to large complex molecules that are structurally unrelated, such as thyroglobulin and DNA. As a first approximation, there is a linear correlation between degree of sequence identity or hydrophobicity/hydrophilicity and antigenic cross-binding. However, catastrophic interchanges of amino acids can occur where changing of one amino acid out of 16 in a synthetic peptide essentially eliminates binding to certain antibodies. An operational definition of epitope promiscuity for peptides is the case where two peptides show little or no identity in amino acid sequence but bind strongly to the same antibody as shown by either direct binding or competitive inhibition. Analysis of antibodies of humans and sharks, the two most divergent species in evolution to express antibodies and the combinatorial immune response, indicates that the capacity for both exquisite specificity and epitope recognition promiscuity are essential conserved features of individual vertebrate antibodies.

  9. Efficient Methods To Isolate Human Monoclonal Antibodies from Memory B Cells and Plasma Cells.

    Science.gov (United States)

    Corti, Davide; Lanzavecchia, Antonio

    2014-10-01

    In this article, we highlight the advantages of isolating human monoclonal antibodies from the human memory B cells and plasma cell repertoires by using high-throughput cellular screens. Memory B cells are immortalized with high efficiency using Epstein-Barr virus (EBV) in the presence of a toll-like receptor (TLR) agonist, while plasma cells are maintained in single-cell cultures by using interleukin 6 (IL-6) or stromal cells. In both cases, multiple parallel assays, including functional assays, can be used to identify rare cells that produce antibodies with unique properties. Using these methods, we have isolated potent and broadly neutralizing antibodies against a variety of viruses, in particular, a pan-influenza-A-neutralizing antibody and an antibody that neutralizes four different paramyxoviruses. Given the high throughput and the possibility of directly screening for function (rather than just binding), these methods are instrumental to implement a target-agnostic approach to identify the most effective antibodies and, consequently, the most promising targets for vaccine design. This approach is exemplified by the identification of unusually potent cytomegalovirus-neutralizing antibodies that led to the identification of the target, a pentameric complex that we are developing as a candidate vaccine.

  10. Production and Characterization of Anti-Her2 Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    A.S. Tabatabaei-Panah

    2008-01-01

    Full Text Available Objective: Breast cancer is the most common cancer among women in the world.Early diagnosis of this cancer is a key element for its treatment. One of the approachesfor diagnosis of breast cancer is detection of its tumour-associated markers. Hence,Her2 has been the main focus of the researches in the field.Materials and Methods: For diagnosis of Her2 overexpression, monoclonalantibodies (mAb reacting against Her2 were produced in this study. For thispurpose, two peptides from extracellular domain of Her2 were selected and themAbs reacting against them were produced by hybrodoma technology. Reactivityof these antibodies were then evaluated in different immunological assays includingELISA, Immunoflurescence (IF, western blot (WB and immunoprecipitation (IP.Results: Total of 5 clones were produced from two separate fusions, and antibodyisotyping revealed that all clones were IgM. These mAbs showed appropriatereactivities in the following assays: ELISA, immunofluresence by staining of breastcancer cell line (SKBR3, WB and IP by detecting the 185 KD band of Her2.Conclusion: In conclusion, it seems that the mAbs are useful diagnostic tools fordetection of Her2 expression in patients with breast cancer.

  11. Human oxidation-specific antibodies reduce foam cell formation and atherosclerosis progression

    DEFF Research Database (Denmark)

    Tsimikas, Sotirios; Miyanohara, Atsushi; Hartvigsen, Karsten

    2011-01-01

    We sought to assess the in vivo importance of scavenger receptor (SR)-mediated uptake of oxidized low-density lipoprotein (OxLDL) in atherogenesis and to test the efficacy of human antibody IK17-Fab or IK17 single-chain Fv fragment (IK17-scFv), which lacks immunologic properties of intact antibod...... antibodies other than the ability to inhibit uptake of OxLDL by macrophages, to inhibit atherosclerosis....

  12. Improved radioimmunoscintigraphy of human mammary carcinoma xenografts after injection of an anti-antibody

    Energy Technology Data Exchange (ETDEWEB)

    Senekowitsch, R.; Bode, W.; Glaessner, H.; Moellenstaedt, S.; Kriegel, H.; Reidel, G.; Pabst, H.W.

    1987-02-01

    The low tumor-to-background ratio obtained after administration of radiolabeled whole monoclonal antibodies (MAbs) is one of the major problems in immunoscintigraphy and -therapy. To reduce the blood pool label caused by the circulation of radiolabeled MAb we have investigated the advantage of injecting an anti-antibody after administration of tumor-specific MAb in nude mice bearing human mammary carcinoma xenografts. The MAb MA 10-11 of rat origin, used in these studies, had shown a high affinity to human mammary carcinoma tissue on frozen sections and low cross-reactivity with various normal human tissues. 24 h after injection of 1.5 MBq /sup 131/I-labeled MAb containing 10 ..mu..g IgG/sub 2a/ one group of mice received an additional injection of 100 ..mu..g anti-rat antibody. Blood taken 2 min after the second antibody injection showed nearly the whole activity bound to antibody aggregates, that cleared very rapidly from the circulation and accumulated in liver and spleen. The transitory high liver activity decreased within several hours because of rapid deiodination of the antibody-complex in this organ. The release of radioactivity from the spleen, however, was found to be much slower. The rapid excretion of the radioactivity from the blood pool combined with a nearly constant tumor activity allowed early tumor detection with tumor-to-blood ratios of 250:1 at 48 h after anti-antibody injection compared to 1.1:1 obtained for the control animals. In addition the results may explain the reported reduction of imaging quality and high uptake of radioactivity in the spleen of patients having repeated injections of mouse MAbs due to complex formation after development of human anti-mouse antibodies

  13. Monoclonal antibody to human endothelial cell surface internalization and liposome delivery in cell culture.

    Science.gov (United States)

    Trubetskaya, O V; Trubetskoy, V S; Domogatsky, S P; Rudin, A V; Popov, N V; Danilov, S M; Nikolayeva, M N; Klibanov, A L; Torchilin, V P

    1988-02-01

    A monoclonal antibody (mAb), E25, is described that binds to the surface of cultured human endothelial cells. Upon binding E25 is rapidly internalized and digested intracellularly. Selective liposome targeting to the surface of the cells is performed using a biotinylated E25 antibody and an avidin-biotin system. Up to 30% of the cell-adherent liposomal lipid is internalized.

  14. Exploring the antigenic response to multiplexed immunizations in a chicken model of antibody production

    DEFF Research Database (Denmark)

    Kousted, Tina Mostrup; Kalliokoski, Otto; Christensen, Sofie Kjellerup

    2017-01-01

    . With an upper limit of 1 mg protein material recommended for chicken immunizations, we found that the maximum number of immunogens that can be reliably used is most likely in the low double digits. The limiting factor for a response to an immunogen could not be related to the number of splenic plasma cells...... plasma cell involvement of less than 5%. Two breeds of egg-layers were compared with respect to antibody production in an initial experiment, but differences in antibody productivity were negligible. Although our findings support the use of multiplexed immunizations in the hen, we find that the number...

  15. A two-in-one antibody engineered from a humanized interleukin 4 antibody through mutation in heavy chain complementarity-determining regions.

    Science.gov (United States)

    Lee, Chingwei V; Koenig, Patrick; Fuh, Germaine

    2014-01-01

    A mono-specific antibody may recruit a second antigen binding specificity, thus converting to a dual-specific Two-in-One antibody through mutation at the light chain complementarity-determining regions (CDRs). It is, however, unknown whether mutation at the heavy chain CDRs may evolve such dual specificity. Herein, we examined the CDRs of a humanized interleukin 4 (IL4) antibody using alanine scanning and structural modeling, designed libraries of mutants in regions that tolerate mutation, and isolated dual specific antibodies harboring mutation at the heavy chain CDRs only. We then affinity improved an IL4/IL5 dual specific antibody to variants with dissociation constants in the low nanomolar range for both antigens. The results demonstrate the full capacity of antibodies to evolve dual binding specificity.

  16. Human antibody recognition of Anisakidae and Trichinella spp. in Greenland

    DEFF Research Database (Denmark)

    Møller, L N; Krause, T Grove; Koch, A

    2007-01-01

    High levels of total IgE are observed among children in Greenland. To evaluate the extent to which Anisakidae and Trichinella spp. contribute to the high total IgE level, an ELISA and a western blot were developed for the detection of IgG antibodies to Anisakidae, based on excretory....../secretory antigens from Anisakidae larvae. Western blots with Anisakidae and Trichinella antigens discriminated between Anisakidae and Trichinella infections, enabling cross-reactivity between the two parasite infections to be eliminated. Serum samples from 1012 children in Greenland were analysed for specific...

  17. Biochemical and pharmacological characterization of human c-Met neutralizing monoclonal antibody CE-355621

    Science.gov (United States)

    Michaud, Neil R.; Jani, Jitesh P.; Hillerman, Stephen; Tsaparikos, Konstantinos E.; Barbacci-Tobin, Elsa G.; Knauth, Elisabeth; Putz Jr., Henry; Campbell, Mary; Karam, George A.; Chrunyk, Boris; Gebhard, David F.; Green, Larry L.; Xu, Jinghai J.; Dunn, Margaret C.; Coskran, Tim M.; Lapointe, Jean-Martin; Cohen, Bruce D.; Coleman, Kevin G.; Bedian, Vahe; Vincent, Patrick; Kajiji, Shama; Steyn, Stefan J.; Borzillo, Gary V.; Los, Gerrit

    2012-01-01

    The c-Met proto-oncogene is a multifunctional receptor tyrosine kinase that is stimulated by its ligand, hepatocyte growth factor (HGF), to induce cell growth, motility and morphogenesis. Dysregulation of c-Met function, through mutational activation or overexpression, has been observed in many types of cancer and is thought to contribute to tumor growth and metastasis by affecting mitogenesis, invasion, and angiogenesis. We identified human monoclonal antibodies that bind to the extracellular domain of c-Met and inhibit tumor growth by interfering with ligand-dependent c-Met activation. We identified antibodies representing four independent epitope classes that inhibited both ligand binding and ligand-dependent activation of c-Met in A549 cells. In cells, the antibodies antagonized c-Met function by blocking receptor activation and by subsequently inducing downregulation of the receptor, translating to phenotypic effects in soft agar growth and tubular morphogenesis assays. Further characterization of the antibodies in vivo revealed significant inhibition of c-Met activity (≥ 80% lasting for 72–96 h) in excised tumors corresponded to tumor growth inhibition in multiple xenograft tumor models. Several of the antibodies identified inhibited the growth of tumors engineered to overexpress human HGF and human c-Met (S114 NIH 3T3) when grown subcutaneously in athymic mice. Furthermore, lead candidate antibody CE-355621 inhibited the growth of U87MG human glioblastoma and GTL-16 gastric xenografts by up to 98%. The findings support published pre-clinical and clinical data indicating that targeting c-Met with human monoclonal antibodies is a promising therapeutic approach for the treatment of cancer. PMID:23007574

  18. Prokaryotic expression and renaturation of engineering chimeric Fab antibody against human hepatoma

    Institute of Scientific and Technical Information of China (English)

    Jin-Liang Xing; Xiang-Min Yang; Xi-Ying Yao; Fei Song; Zhi-Nan Chen

    2004-01-01

    AIM: To express chimeric Fd (cFd) and chimeric light chain (cL) in E.coli respectively and refold them into chimeric Fab (cFab) antibody.METHODS: cFd and cL genes were respectively inserted into the prokaryotic expression vector pET32a to construct recombinant vectors pET32a/cFd and pET32a/cL. Then,the competent E. colicells were transformed by the recombinant vectors and induced by IPTG. Moreover, a large quantity of cFd and cL expression products were prepared and mixed with equal molar to refold into cFab by gradient dialysis. The refolded products were identified and analyzed by sodium SDS-PAGE, Western blotting,ELISA and HPLC.RESULTS: High efficient prokaryotic expressions of both cFd and cL in the form of non-fusion protein were obtained with the expression levels of 28.3% and 32.3% of total bacteria proteins, respectively. Their relative molecular masses were all 24 ku or so, and both of them mainly existed in the form of inclusion bodies. In addition, cFd and cL were successfully refolded into cFab by gradient dialysis, with about 59.45% of recovery when the starting total protein concentration was 100 μg/mL. The renatured cFab could specifically bind to related antigen with high affinity.CONCLUSION: The cFab antibody against human hepatoma was highly and efficiently expressed and refolded, which laid a solid foundation for studying its application in the treatment of hepatoma.

  19. 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 ...... of human anti-mouse IgG antibodies (HAMA), described to create false positive results, may be due to a crossreacting fraction of the polyclonal circulating antibodies against bovine IgG.......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...

  20. RNA recognition by a human antibody against brain cytoplasmic 200 RNA.

    Science.gov (United States)

    Jung, Euihan; Lee, Jungmin; Hong, Hyo Jeong; Park, Insoo; Lee, Younghoon

    2014-06-01

    Diverse functional RNAs participate in a wide range of cellular processes. The RNA structure is critical for function, either on its own or as a complex form with proteins and other ligands. Therefore, analysis of the RNA conformation in cells is essential for understanding their functional mechanisms. However, no appropriate methods have been established as yet. Here, we developed an efficient strategy for panning and affinity maturation of anti-RNA human monoclonal antibodies from a naïve antigen binding fragment (Fab) combinatorial phage library. Brain cytoplasmic 200 (BC200) RNA, which is also highly expressed in some tumors, was used as an RNA antigen. We identified MabBC200-A3 as the optimal binding antibody. Mutagenesis and SELEX experiments showed that the antibody recognized a domain of BC200 in a structure- and sequence-dependent manner. Various breast cancer cell lines were further examined for BC200 RNA expression using conventional hybridization and immunoanalysis with MabBC200-A3 to see whether the antibody specifically recognizes BC200 RNA among the total purified RNAs. The amounts of antibody-recognizable BC200 RNA were consistent with hybridization signals among the cell lines. Furthermore, the antibody was able to discriminate BC200 RNA from other RNAs, supporting the utility of this antibody as a specific RNA structure-recognizing probe. Intriguingly, however, when permeabilized cells were subjected to immunoanalysis instead of purified total RNA, the amount of antibody-recognizable RNA was not correlated with the cellular level of BC200 RNA, indicating that BC200 RNA exists as two distinct forms (antibody-recognizable and nonrecognizable) in breast cancer cells and that their distribution depends on the cell type. Our results clearly demonstrate that anti-RNA antibodies provide an effective novel tool for detecting and analyzing RNA conformation.

  1. Phenotyping and auto-antibody production by liver-infiltrating B cells in primary sclerosing cholangitis and primary biliary cholangitis.

    Science.gov (United States)

    Chung, Brian K; Guevel, Bardia T; Reynolds, Gary M; Gupta Udatha, D B R K; Henriksen, Eva Kristine Klemsdal; Stamataki, Zania; Hirschfield, Gideon M; Karlsen, Tom Hemming; Liaskou, Evaggelia

    2017-02-01

    Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are immune-mediated biliary diseases that demonstrate prominent and restricted genetic association with human leukocyte antigen (HLA) alleles. In PBC, anti-mitochondrial antibodies (AMA) are specific and used as diagnostic biomarkers. PSC-relevant auto-antibodies remain controversial despite a distinct HLA association that mirrors archetypical auto-antigen driven disorders. Herein, we compared antibody-secreting B cells (ASCs) in PSC and PBC liver explants to determine if liver-infiltrating ASCs represent an opportune and novel source of disease-relevant auto-antibodies. Using enzymatic digestion and mechanical disruption, liver mononuclear cells (LIMCs) were isolated from fresh PSC and PBC explants and plasmablast (CD19+CD27+CD38(hi)CD138-) and plasma cell (CD19+CD27+CD38(hi)CD138+) ASCs were enumerated by flow cytometry. We observed 45-fold fewer plasma cells in PSC explants (n = 9) compared to PBC samples (n = 5, p < 0.01) and 10-fold fewer IgA-, IgG- and IgM-positive ASCs (p < 0.05). Liver-infiltrating ASCs from PSC and PBC explants were functional and produced similar concentrations of IgA, IgG and IgM following 2 weeks of culture. Antibody production by PBC ASCs (n = 3) was disease-specific as AMA to pyruvate dehydrogenase complex E2 subunit (PDC-E2) was detected by immunostaining, immunoblotting and ELISA. Antibody profiling of PSC supernatants (n = 9) using full-length recombinant human protein arrays (Cambridge Protein Arrays) revealed reactivities to nucleolar protein 3 (5/9) and hematopoietic cell-specific Lyn substrate 1 (3/9). Array analysis of PBC supernatants (n = 3) detected reactivities to PDC-E2 and hexokinase 1 (3/3). In conclusion, we detected unique frequencies of liver-infiltrating ASCs in PSC and PBC and in so doing, highlight a feasible approach for understanding disease-relevant antibodies in PSC. Copyright © 2016. Published by Elsevier Ltd.

  2. Preparation of Monoclonal Antibodies and a Simple Myeloperoxidase-Immunosorbent Assay for Detecting Human Myeloperoxidase.

    Science.gov (United States)

    Bian, Zhi-Ping; Li, Xiong-Zhi; Wu, Heng-Fang; Xu, Jin-Dan; Gu, Chun-Rong; Chen, Xiang-Jian; Yang, Di

    2016-04-01

    Myeloperoxidase (MPO), a leukocyte hemoprotein released from neutrophils, is thought to be a potential participant in plaque formation and plaque rupture. Therefore, MPO is regarded as an early marker predicting the risk for atherosclerosis, especially for coronary artery disease and acute coronary syndrome. We generated hybridoma clones 1E3 and 3E8 secreting monoclonal antibodies (mAbs) specific to human MPO. BALB/c mice were immunized with MPO protein purified from human neutrophils. Splenocytes from these mice were fused with the mouse myeloma cell line SP2/0. Based on isotyping of the mAbs, both clones 1E3 and 3E8 were referred to the IgG1 subclass. The specificities of 1E3 and 3E8 were assessed by enzyme-linked immunosorbent assay (ELISA), and only 3E8 was confirmed by western blot. We developed a simple MPO-immunosorbent assay (MPO-ISA) on microplate based on both the immune activity and peroxidase activity of MPO. The mAb secreted by clone 3E8 was chosen as coating antibody to capture the plasma MPO without interfering with the peroxidase activity of MPO. Then, tetramethylbenzidine substrate was added to the microwell directly, catalyzed by captured MPO, and a colored product was formed. The simple MPO-ISA test has a sensitivity of 3.68 ng/mL. The linear concentration of MPO-ISA for commercial MPO standard ranged to 250 ng/mL. The average recovery rate is 101.02%. The imprecision within-day was ISA can detect the plasma MPO from human and cavy, but not from mouse and rat. Compared with the commercial human MPO ELISA assay, the MPO-ISA can be used to detect the natural human MPO protein, but not recombinant MPO polypeptides. The generated mAbs and MPO-ISA test may be useful tools to assess risk for inflammation and cardiac events.

  3. Rapid transient production in plants by replicating and non-replicating vectors yields high quality functional anti-HIV antibody.

    Directory of Open Access Journals (Sweden)

    Frank Sainsbury

    Full Text Available The capacity of plants and plant cells to produce large amounts of recombinant protein has been well established. Due to advantages in terms of speed and yield, attention has recently turned towards the use of transient expression systems, including viral vectors, to produce proteins of pharmaceutical interest in plants. However, the effects of such high level expression from viral vectors and concomitant effects on host cells may affect the quality of the recombinant product.To assess the quality of antibodies transiently expressed to high levels in plants, we have expressed and characterised the human anti-HIV monoclonal antibody, 2G12, using both replicating and non-replicating systems based on deleted versions of Cowpea mosaic virus (CPMV RNA-2. The highest yield (approximately 100 mg/kg wet weight leaf tissue of affinity purified 2G12 was obtained when the non-replicating CPMV-HT system was used and the antibody was retained in the endoplasmic reticulum (ER. Glycan analysis by mass-spectrometry showed that the glycosylation pattern was determined exclusively by whether the antibody was retained in the ER and did not depend on whether a replicating or non-replicating system was used. Characterisation of the binding and neutralisation properties of all the purified 2G12 variants from plants showed that these were generally similar to those of the Chinese hamster ovary (CHO cell-produced 2G12.Overall, the results demonstrate that replicating and non-replicating CPMV-based vectors are able to direct the production of a recombinant IgG similar in activity to the CHO-produced control. Thus, a complex recombinant protein was produced with no apparent effect on its biochemical properties using either high-level expression or viral replication. The speed with which a recombinant pharmaceutical with excellent biochemical characteristics can be produced transiently in plants makes CPMV-based expression vectors an attractive option for

  4. Rapid Transient Production of a Monoclonal Antibody Neutralizing the Porcine Epidemic Diarrhea Virus (PEDV) in Nicotiana benthamiana and Lactuca sativa.

    Science.gov (United States)

    Rattanapisit, Kaewta; Srijangwad, Anchalee; Chuanasa, Taksina; Sukrong, Suchada; Tantituvanont, Angkana; Mason, Hugh S; Nilubol, Dachrit; Phoolcharoen, Waranyoo

    2017-06-02

    Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea, vomiting, dehydration, weight loss, and high mortality rate in neonatal piglets. Porcine epidemic diarrhea (PED) has been reported in Europe, America, and Asia including Thailand. The disease causes substantial losses to the swine industry in many countries. Presently, there is no effective PEDV vaccine available. In this study, we developed a plant-produced monoclonal antibody (mAb) 2C10 as a prophylactic candidate to prevent the PEDV infection. Recently, plant expression systems have gained interest as an alternative for the production of antibodies because of many advantages, such as low production cost, lack of human and animal pathogen, large scalability, etc. The 2C10 mAb was transiently expressed in Nicotiana benthamiana and lettuce using geminiviral vector. After purification by protein A affinity chromatography, the antibody was tested for the binding and neutralizing activity against PEDV. Our result showed that the plant produced 2C10 mAb can bind to the virus and also inhibit PEDV infection in vitro. These results show excellent potential for a plant-expressed 2C10 as a PEDV prophylaxis and a diagnostic for PEDV infection. Georg Thieme Verlag KG Stuttgart · New York.

  5. Proteoliposome-based selection of a recombinant antibody fragment against the human M2 muscarinic acetylcholine receptor.

    Science.gov (United States)

    Suharni; Nomura, Yayoi; Arakawa, Takatoshi; Hino, Tomoya; Abe, Hitomi; Nakada-Nakura, Yoshiko; Sato, Yumi; Iwanari, Hiroko; Shiroishi, Mitsunori; Asada, Hidetsugu; Shimamura, Tatsuro; Murata, Takeshi; Kobayashi, Takuya; Hamakubo, Takao; Iwata, So; Nomura, Norimichi

    2014-12-01

    The development of antibodies against human G-protein-coupled receptors (GPCRs) has achieved limited success, which has mainly been attributed to their low stability in a detergent-solubilized state. We herein describe a method that can generally be applied to the selection of phage display libraries with human GPCRs reconstituted in liposomes. A key feature of this approach is the production of biotinylated proteoliposomes that can be immobilized on the surface of streptavidin-coupled microplates or paramagnetic beads and used as a binding target for antibodies. As an example, we isolated a single chain Fv fragment from an immune phage library that specifically binds to the human M2 muscarinic acetylcholine receptor with nanomolar affinity. The selected antibody fragment recognized the GPCR in both detergent-solubilized and membrane-embedded forms, which suggests that it may be a potentially valuable tool for structural and functional studies of the GPCR. The use of proteoliposomes as immunogens and screening bait will facilitate the application of phage display to this difficult class of membrane proteins.

  6. Generation and characterization of human B lymphocyte stimulator blocking monoclonal antibody.

    Science.gov (United States)

    Zhuang, Weiliang; Zhang, Jianjun; Pei, Lili; Fang, Shuping; Liu, Honghao; Wang, Ruixue; Su, Yunpeng

    2016-09-01

    The cytokine, B lymphocyte stimulator (Blys) is essential for activation and proliferation of B cells and is involved in the pathogenesis of B-cell mediated autoimmune diseases. Based on its essential activity, Blys may be a potential therapeutic target for human autoimmune diseases. In this article, we have described the development of a novel humanized anti-Blys antibody, NMB04, that binds with high affinity and specificity to both soluble and membrane bound Blys. This monoclonal antibody has the potential to block Blys binding to all its three receptors, TACI, BCMA and BR-3. Further in vivo studies revealed that NMB04 possessed more potent inhibitory activity against human Blys as compared to an existing antibody, Belimumab. Therefore, NMB04 may have potential as a therapeutic candidate targeting autoimmune diseases.

  7. Rheumatoid factor interference in immunogenicity assays for human monoclonal antibody therapeutics.

    Science.gov (United States)

    Tatarewicz, Suzanna; Miller, Jill M; Swanson, Steven J; Moxness, Michael S

    2010-05-31

    Rheumatoid factors (RFs) are endogenous human antibodies that bind to human gamma globulins. RFs demonstrate preferential binding to aggregated gamma globulins and are involved in the clearing mechanism of immune complexes. Immunoassays designed to measure human anti-human antibodies (HAHA) after administration of monoclonal antibody therapeutics are thus vulnerable to interference from RFs. When using a sensitive electrochemiluminescent (ECL) bridging immunoassay, samples from subjects with rheumatoid arthritis demonstrated much higher baseline reactivity than healthy subjects. Interference was found to be dependent on the aggregation state of the therapeutic antibody that had been conjugated with the detection reagent (ruthenium). Size exclusion high performance liquid chromatography (SE-HPLC) demonstrated that of the total integrated peaks, as little as 0.55% high molecular weight aggregates (>600kDa) were sufficient to cause increased reactivity. Stability studies of the ruthenium and biotin conjugated therapeutic antibody indicated that storage time, temperature and buffer formulation were critical in maintaining the integrity of the reagents. Through careful SE-HPLC monitoring we were able to choose appropriate storage and buffer conditions which led to a reduction in the false reactivity rate in therapeutic-naïve serum from a rheumatoid arthritis population.

  8. Isolation of human anti-serum albumin Fab antibodies with an extended serum-half life.

    Science.gov (United States)

    Kang, Hyeon-Ju; Kim, Hye-Jin; Cha, Sang-Hoon

    2016-01-01

    The serum albumin (SA) has been exploited to generate long-acting biotherapeutics by taking advantage of the FcRn-mediated recycling mechanism in a direct or an indirect way. Since Fab fragments have been proven to be clinically safe for human usage, we assumed that human anti-SA Fab antibodies could have a great potential as a carrier molecule to extend the serum half-life of therapeutic proteins. We, herein, had attempted to isolate anti-SA Fab antibodies from HuDVFab-8L antibody library via a phage display technology, and identified eight discrete human Fab antibodies. One of the Fab antibodies, SL335, showed the strongest binding reactivity to human SA with nM range of affinity at both pH 6 and pH 7.4, and cross-reacted to SAs from various species including rat, mouse, canine and monkey. The in vivo pharmacokinetic assay using a rat model indicated that SL335 has approximately 10 fold longer serum half-life and 26 to 44-fold increase in AUC0 → ∞ compared to the negative control Fab molecule in both intravenous and subcutaneous administrations. Knowing that Fabs have proven to be safe in clinics for a long time, SL335 seems to have a great potential in generating long-acting protein drugs by tagging effector molecules with either chemical conjugation or genetic fusion.

  9. Potential use of humanized antibodies in the treatment of breast cancer.

    Science.gov (United States)

    Schaefer, Niklaus G; Pestalozzi, Bernhard C; Knuth, Alexander; Renner, Christoph

    2006-07-01

    With the growing knowledge of key cellular pathways in tumor induction and evolution, targeted therapies make up an increasing proportion of new drugs entering clinical testing. In the treatment of breast cancer, humanized antibodies have become a major option. The humanized monoclonal antibody trastuzumab (Herceptin); Genentech, Inc., CA, USA) for HER2-overexpressing, metastatic breast cancer, represents a successful agent associated with impressive survival benefits when combined with chemotherapy. Based on impressive results, trastuzumab will become a standard in the adjuvant treatment of HER2-overexpressing breast cancer. The role of trastuzumab in the neoadjuvant setting is promising, but must be further evaluated in large prospective, randomized trials. However, there is still a large proportion of patients overexpressing HER2 that do not respond to trastuzumab. Regarding this patient cohort, the optimal combination of trastuzumab with other agents needs further evaluation. In breast cancer lacking HER2 amplification, the role of the new antibody pertuzumab remains to be defined. The role of antibodies interfering with angiogenesis, tumor stroma or glycoproteins is of a preliminary nature and warrants further investigation. Here, an overview of humanized antibodies in human breast cancer is provided, with emphasis on the recent advances and future prospects in treating malignant breast cancer.

  10. Isolation of Anti-Ricin Protective Antibodies Exhibiting High Affinity from Immunized Non-Human Primates

    Directory of Open Access Journals (Sweden)

    Tal Noy-Porat

    2016-03-01

    Full Text Available Ricin, derived from the castor bean plant Ricinus communis, is one of the most potent and lethal toxins known, against which there is no available antidote. To date, the use of neutralizing antibodies is the most promising post-exposure treatment for ricin intoxication. The aim of this study was to isolate high affinity anti-ricin antibodies that possess potent toxin-neutralization capabilities. Two non-human primates were immunized with either a ricin-holotoxin- or subunit-based vaccine, to ensure the elicitation of diverse high affinity antibodies. By using a comprehensive set of primers, immune scFv phage-displayed libraries were constructed and panned. A panel of 10 antibodies (five directed against the A subunit of ricin and five against the B subunit was isolated and reformatted into a full-length chimeric IgG. All of these antibodies were found to neutralize ricin in vitro, and several conferred full protection to ricin-intoxicated mice when given six hours after exposure. Six antibodies were found to possess exceptionally high affinity toward the toxin, with KD values below pM (koff < 1 × 10−7 s−1 that were well correlated with their ability to neutralize ricin. These antibodies, alone or in combination, could be used for the development of a highly-effective therapeutic preparation for post-exposure treatment of ricin intoxication.

  11. Evaluation of human antibody responses to diphtheria toxin subunits A and B in various age groups.

    Science.gov (United States)

    Karakus, R; Caglar, K; Aybay, C

    2007-11-01

    This study aimed to evaluate human antibody responses to diphtheria toxin subunits in various age groups. Antibodies against the intact diphtheria toxin and the diphtheria toxin subunits A and B were evaluated in 1319 individuals using a double-antigen ELISA. Although high levels of protection (83.6%, 95% CI 79.2-87.4) were found in children and adolescents, the middle-aged adult population was less protected (28.8%, 95% CI 24.3-33.6). An increase in age was associated with a decrease in the frequency of protected individuals in the 0-39-year age group (p antibodies against the intact toxin. In children aged antibodies were observed were found to correlate with the ages at which booster doses are administered. Overall, males appeared to be more protected than females (OR 1.67, 95% CI 1.34-2.08, p antibody levels of > or =0.1 IU/mL against the intact toxin, but did not have protective antibody against subunit B. Determination of anti-subunit B antibody levels should help in evaluating the effectiveness of diphtheria boosters and other aspects of diphtheria immunity.

  12. Antibody response to Salmonella typhi lw human Schistosomiasis mansoni

    Directory of Open Access Journals (Sweden)

    Maria Imaculada Muniz-Junqueira

    1996-10-01

    Full Text Available Antibody response to Salmonella typhi O and H antigens was evaluated in 24 individuals with either hepatointestinal or hepatosplenic schistosomiasis mansoni before and after typhoid vaccination, and compared with that of non-infected controls. Before vaccination, Schistosoma-infected patients showed a higher frequency of positive antibody to O antigen and the same frequency to H antigen when compared with that of healthy individuals. However, those with hepatosplenic schistosomiasis showed higher titres of antibody to H antigen than those with hepatointestinal disease or healthy individuals. Infected subjects, particularly those with hepatointestinal disease, showed a decreased response after typhoid vaccine. Tins diminished ability to mount an immune response towards typhoid antigens dining schistosomiasis may interfere ivith the clearance of the bacteria from blood stream and, therefore, play a role in the prolonged survival of salmonella as obsewed in some patients with chronic salmonellosis associated with schistosomiasis.A resposta de anticorpos para os antígenos O e H da Salmonella typhi foi avaliada em 24 indivíduos com esquistossomose hepatointestinal ou hepatoesplênica antes e apôs vacinação antitifoídica, e comparada com a resposta de indivíduos controles normais. Antes da vacinação, pacientes esquistossomóticos mostraram uma maior frequência de anticoipos positivos para o antígeno O e a mesma frequência de anticoipos positivos para o antígeno H quando comparada com aquela de indivíduos controles normais. Porém, aqueles com esquistossomose hepatoesplênica mostraram títulos maiores de anticoipos para o antígeno H do que aqueles com a forma hepatointestinal da doença ou os indivíduos controles normais. Pacientes esquistossomóticos, particularmente aqueles com a forma hepatointestinal, mostraram uma menor resposta após a vacinação antitifoídica. Esta menor capacidade para apresentar uma resposta imune para ant

  13. Characterization of human 1,25-dihydroxyvitamin D3 receptor anti-peptide antibodies.

    Science.gov (United States)

    Tuohimaa, P; Bläuer, M; Jääskeläinen, T; Itkonen, A; Lindfors, M; Mahonen, A; Palvimo, J; Vilja, P; Mäenpää, P H

    1992-12-01

    Rabbit and chicken antibodies were raised against two peptides synthesized according to the structure of human 1,25-dihydroxyvitamin D3 receptor (hVDR): rabbit alpha hVDR-103 against the N-terminal amino acids 5-18 and alpha hVDR-104 against the amino acids 172-186 in the hinge region and chicken alpha hVDR-cab11 against the amino acids 172-186, respectively. The specificity of the antibodies was tested by peptide saturation, SDS-PAGE immunoblotting, gel shift assay and sucrose gradient centrifugation. Immunoblotting of a soluble extract (cytosol) from osteosarcoma cell line MG-63 showed a single band with an M(r) of about 48,000 and human intestine cytosol a broad band (50-63,000) for both antibodies. The antibodies recognized activated (3.2S) hVDR by shifting the centrifugation sedimentation profile to 5-6S. The antibodies showed nuclear immunostaining of unoccupied VDR in human osteosarcoma cells MG-63, U2-Os and SaOs-2. The immunoreaction could be saturated with the corresponding synthetic peptide. In immunoblot alpha hVDR-103 reacted with human and rat VDR, whereas alpha hVDR-104 recognized human VDR only. Similarly in immunohistochemistry, alpha hVDR-103 showed staining with hVDR and rVDR, whereas alpha hVDR-104 reacted only with hVDR. All antibodies recognized the native hVDR as verified with sucrose gradient centrifugation or immunoprecipitation but only alpha hVDR-103 and alpha hVDR-cab11 in gel shift assay of hVDR associated with the vitamin D-responsive element of human osteocalcin gene promoter.

  14. Effects of glutamine and asparagine on recombinant antibody production using CHO-GS cell lines.

    Science.gov (United States)

    Xu, Ping; Dai, Xiao-Ping; Graf, Erica; Martel, Richard; Russell, Reb

    2014-01-01

    A unique and nontraditional approach using glutamine and asparagine supplements for CHO-glutamine synthetase (GS) cell lines was studied. In our experiments, we found that a decrease in pH and an increase in cell death occurred in production phase of a GS cell line, leading to reduced antibody expression and lower antibody yields. The experimental results and the statistical analysis (ANOVA) indicated that additions of glutamine and asparagine in the basal and feed media were effective to buffer the cell culture pH, reduce lactate generation, maintain a higher cell viability profile, and improve antibody productivity. In bench-top bioreactors, glutamine and asparagine supplementation helped to prevent cell death, improve antibody yield, and reduce base usage. Glutamine is normally excluded from culture media for GS cell lines to prevent the bypass of selection pressure. In this study, however, the addition of glutamine did not affect cell population homogeneity, protein quality, or decrease antibody yield of two GS cell lines.

  15. The characteristics of human antibody targeting the Epidermal Growth Factor Receptor in vivo for radioimmunotherapy in a small animal model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Jung; Choi, Tae Hyun; Kim, Byoung Soo; Cheon, Gi Jeong [Korea Institue of Radiological and Medical Sciences, Seoul (Korea, Republic of); Hong, Kwang Won; Chang, Ki Hwan; Shin, Yong Won; Ryoo, Kyung Hwan; Shin, Yong Nam; Kim, Se Ho [Green Cross Corp., Yongin (Korea, Republic of)

    2010-05-15

    The identification of epidermal growth factor receptor (EGFR) as an oncogene has led to the development of anticancer therapeutics directed against EGFR, including Erbitux for colon cancer. Many therapeutic approaches are aimed at the EGFR. Erbitux is example of monoclonal antibody inhibitors. The monoclonal antibodies block the extracellular ligand binding domain. EGFR4-2, IgG human monoclonal antibody, has been developed on the basis of human antibody gene library in Green Cross Corp. Small animal imaging is useful for preclinical evaluation of radiolabeled antibody to see biodistribution and targeting ability at serial time points in same animals

  16. Lineage Structure of the Human Antibody Repertoire in Response to Influenza Vaccination

    Science.gov (United States)

    Jiang, Ning; He, Jiankui; Weinstein, Joshua A.; Penland, Lolita; Sasaki, Sanae; He, Xiao-Song; Dekker, Cornelia L.; Zheng, Nai-ying; Huang, Min; Sullivan, Meghan; Wilson, Patrick C.; Greenberg, Harry B.; Davis, Mark M.; Fisher, Daniel S.; Quake, Stephen R.

    2013-01-01

    The human antibody repertoire is one of the most important defenses against infectious disease, and the development of vaccines has enabled the conferral of targeted protection to specific pathogens. However, there are many challenges to measuring and analyzing the immunoglobulin sequence repertoire, such as the fact that each B cell contains a distinct antibody sequence encoded in its genome, that the antibody repertoire is not constant but changes over time, and the high similarity between antibody sequences. We have addressed this challenge by using high-throughput long read sequencing to perform immunogenomic characterization of expressed human antibody repertoires in the context of influenza vaccination. Informatic analysis of 5 million antibody heavy chain sequences from healthy individuals allowed us to perform global characterizations of isotype distributions, determine the lineage structure of the repertoire and measure age and antigen related mutational activity. Our analysis of the clonal structure and mutational distribution of individuals’ repertoires shows that elderly subjects have a decreased number of lineages but an increased pre-vaccination mutation load in their repertoire and that some of these subjects have an oligoclonal character to their repertoire in which the diversity of the lineages is greatly reduced relative to younger subjects. We have thus shown that global analysis of the immune system’s clonal structure provides direct insight into the effects of vaccination and provides a detailed molecular portrait of age-related effects. PMID:23390249

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

    NARCIS (Netherlands)

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

    2005-01-01

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

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

    NARCIS (Netherlands)

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

    2000-01-01

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

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

    NARCIS (Netherlands)

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

    2005-01-01

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

  20. Generation of mouse anti-human urate anion exchanger antibody by genetic immunization and its identification

    Institute of Scientific and Technical Information of China (English)

    XU Guo-shuang; WU Di; CHEN Xiang-mei; SHI Suo-zhu; HONG Quan; ZHANG Ping; LU Yang

    2005-01-01

    Background Human urate anion exchanger (hURAT1) as a major urate transporter expressed on renal tubular epithelial cells regulates blood urate level by reabsorbing uric acid. Antibody is an important tool to study hURAT1. This study aimed, by genetic immunization, to produce mouse anti-hURAT1 polyclonal antibody with high throughput and high specificity and to detect the location of hURAT1 in human kidney.Methods Human renal total RNA was isolated and the entire cDNA of hURAT1 was amplified by RT-PCR. The sequence of intracellular high antigenicity fragment (A280 to R349) was chosen by prediction software of protein antigenicity, and its cDNA was amplified from cDNA of hURAT1, and then cloned into pBQAP-TT vector to construct recombinant plasmid pBQAP-TT-hURAT1-210 for genetic immunization. Mice were inoculated with this recombinant plasmid and two other adjuvant plasmids, pCMVi-GMCSF and pCMVi-Flt3L, which helped to enhance the antibody’s generation. After four weeks, the mice were sacrificed to obtain the anti-hURAT1 antibody from serum. The antibody was identified by western blot analysis and immunohistochemistry. At the same time, rabbit anti-hURAT1 antibody was produced by protein immunization. The specificity and efficiency between the rabbit and mouse anti-hURAT1 antibody were compared by western blot analysis and immunohistochemistry.Results The entire cDNA of hURAT1 and cDNA of its intracellular high immunogenic fragment were amplified successfully. Recombinant plasmid pBQAP-TT-hURAT1-210 for genetic immunization was confirmed by restriction digestion and sequencing. Both the mouse anti-hURAT1 antibody and rabbit anti-hURAT1 antibody recognized 58kD hURAT1 and 64kD glycosylated hURAT1 protein bands in western blot. Immunohistochemically, hURAT1 was located at the brush border membrane of renal proximal tubular cells. In addition, the throughput and specificity of the mouse anti-hURAT1 antibody were higher than those of the rabbit anti-hURAT1 antibody

  1. Tumor microenvironment contributes to Epstein-Barr virus anti-nuclear antigen-1 antibody production in nasopharyngeal carcinoma.

    Science.gov (United States)

    Ai, Ping; Li, Zhiping; Jiang, Yong; Song, Changping; Zhang, Lin; Hu, Huaizhong; Wang, Tao

    2017-08-01

    Nuclear antigen-1 (NA1) protein of Epstein-Barr virus (EBV) is expressed in EBV-infected cells in the microenvironment of cancer. Since immune cells infiltrate abundantly in nasopharyngeal carcinoma (NPC) tumor tissues, we hypothesized that the local tumor microenvironment may perform an important role in the production of antibodies directed at NA1. Furthermore, we hypothesized that anti-NA1 antibody originating in the local microenvironment could be secreted into the saliva of patients with NPC. In the present study, 20 healthy controls and 39 patients with NPC treated with intensity-modulated radiation therapy were recruited for the study. Saliva and serum samples were collected from the NPC patients, and nasopharyngeal tissue samples from the patients with NPC. The titers of anti-NA1 antibody [immunoglobulin A (IgA)] were determined by ELISA. Expression of NA1, human leukocyte antigen-antigen D related (HLA-DR), cluster of differentiation (CD)80, CD86, CD3, CD4, CD19 and IgA was detected by immunohistochemical staining on paraffin-embedded nasopharyngeal tissue sections. Anti-NA1 antibodies were detected in the serum and saliva samples of the patients with NPC. In infiltrating cells, expression of HLA-DR, CD80, CD86, CD3, CD4, CD19 and IgA was detected, indicating that dendritic cells, T lymphocytes and B lymphocytes were all present in the local tumor tissues. Furthermore, expression of EBNA1 protein was detected on the membrane of the NPC tumor cells. Therefore, the NPC tumor microenvironment has the potential to initiate a humoral response to EBNA1 by producing IgA antibodies.

  2. De Novo Sequencing and Resurrection of a Human Astrovirus-Neutralizing Antibody.

    Science.gov (United States)

    Bogdanoff, Walter A; Morgenstern, David; Bern, Marshall; Ueberheide, Beatrix M; Sanchez-Fauquier, Alicia; DuBois, Rebecca M

    2016-05-13

    Monoclonal antibody (mAb) therapeutics targeting cancer, autoimmune diseases, inflammatory diseases, and infectious diseases are growing exponentially. Although numerous panels of mAbs targeting infectious disease agents have been developed, their progression into clinically useful mAbs is often hindered by the lack of sequence information and/or loss of hybridoma cells that produce them. Here we combine the power of crystallography and mass spectrometry to determine the amino acid sequence and glycosylation modification of the Fab fragment of a potent human astrovirus-neutralizing mAb. We used this information to engineer a recombinant antibody single-chain variable fragment that has the same specificity as the parent monoclonal antibody to bind to the astrovirus capsid protein. This antibody can now potentially be developed as a therapeutic and diagnostic agent.

  3. Bispecific Antibodies that Mediate Killing of Cells Infected with Human Immunodeficiency Virus of Any Strain

    Science.gov (United States)

    Berg, Jorg; Lotscher, Erika; Steimer, Kathelyn S.; Capon, Daniel J.; Baenziger, Jurg; Jack, Hans-Martin; Wabl, Matthias

    1991-06-01

    Although AIDS patients lose human immunodeficiency virus (HIV)-specific cytotoxic T cells, their remaining CD8-positive T lymphocytes maintain cytotoxic function. To exploit this fact we have constructed bispecific antibodies that direct cytotoxic T lymphocytes of any specificity to cells that express gp120 of HIV. These bispecific antibodies comprise one heavy/light chain pair from an antibody to CD3, linked to a heavy chain whose variable region has been replaced with sequences from CD4 plus a second light chain. CD3 is part of the antigen receptor on T cells and is responsible for signal transduction. In the presence of these bispecific antibodies, T cells of irrelevant specificity effectively lyse HIV-infected cells in vitro.

  4. Increased Levels of IgG Antibodies against Human HSP60 in Patients with Spondyloarthritis

    DEFF Research Database (Denmark)

    Nielsen, Astrid Hjelholt; Carlsen, Thomas; Deleuran, Bent

    2013-01-01

    severity in relation to HLA-B27 was evaluated.Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella enteritidis...... and Campylobacter jejuni. Disease severity was assessed by the clinical scorings Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI). Levels of IgG1 and IgG3 antibodies against human HSP60...

  5. Discovery of human antibodies against black cobra toxins

    DEFF Research Database (Denmark)

    Øhlenschlæger, Mia; Andersen, Mikael Rørdam; Lohse, Brian

    Snakebite envenoming represents a major health threat intropical parts of the developing world1. Animal-derivedantisera currently constitute the only effective treatment option,but are associated with severe side effects due toincompatibility with the human immune system. We aim atdiscovering human...

  6. IgA antibodies to Toxoplasma gondii in human tears

    NARCIS (Netherlands)

    Meek, B.; Klaren, V.N.A.; Haeringen, van N.J.; Kijlstra, A.; Peek, R.

    2000-01-01

    PURPOSE. To investigate whether mucosal immune responses directed against the ubiquitous parasite Toxoplasma gondii can be detected in tears of healthy humans. METHODS. Nonstimulated tears and blood were obtained from 62 healthy humans (mean age, 35 ± 10 [SD] years). Serum anti-T. gondii immunoglobu

  7. Acute sleep deprivation has no lasting effects on the human antibody titer response following a novel influenza A H1N1 virus vaccination

    Directory of Open Access Journals (Sweden)

    Benedict Christian

    2012-01-01

    Full Text Available Abstract Background Experimental studies in humans have yielded evidence that adaptive immune function, including the production of antigen-specific antibodies, is distinctly impaired when sleep is deprived at the time of first antigen exposure. Here we examined the effects of a regular 24- hour sleep-wake cycle (including 8 hours of nocturnal sleep and a 24-hour period of continuous wakefulness on the 7-week antibody production in 11 males and 13 females in response to the H1N1 (swine flu virus vaccination. The specific antibody titer in serum was assayed by the hemagglutination inhibition test on the days 5, 10, 17, and 52 following vaccination. Results In comparison to the sleep group, sleep-deprived males but not females had reduced serum concentration of H1N1-specific antibodies five days after vaccination, whereas antibody titers at later time points did not differ between the conditions. Conclusions These findings concur with the notion that sleep is a supportive influence in the very early stage of an adaptive immune response to a viral antigen. However, our results do not support the view that acute sleep deprivation has lasting effects on the human antibody titer response to influenza vaccination.

  8. Origin, diversity and maturation of human antiviral antibodies analyzed by high-throughput sequencing

    Directory of Open Access Journals (Sweden)

    Ponraj ePrabakaran

    2012-08-01

    Full Text Available Our understanding of how antibodies are generated and function could help develop effective vaccines and antibody-based therapeutics against viruses such as HIV-1, SARS Coronavirus (CoV, and Hendra and Nipah viruses (henipaviruses. Although broadly neutralizing antibodies (bnAbs against the HIV-1 were observed in patients, elicitation of such bnAbs remains a major challenge when compared to other viral targets. We previously hypothesized that HIV-1 could have evolved a strategy to evade the immune system due to absent or very weak binding of germline antibodies to the conserved epitopes that may not be sufficient to initiate and/or maintain an effective immune response. To further explore our hypothesis, we used the 454 sequence analysis of a large naïve library of human IgM antibodies which had been used for selecting antibodies against SARS Coronavirus (CoV receptor-binding domain (RBD, and soluble G proteins (sG of Hendra and Nipah viruses (henipaviruses. We found that the human IgM repertoires from the 454 sequencing have diverse germline usages, recombination patterns, junction diversity and a lower extent of somatic mutation. In this study, we identified germline intermediates of antibodies specific to HIV-1 and other viruses as observed in normal individuals, and compared their genetic diversity and somatic mutation level along with available structural and functional data. Further computational analysis will provide framework for understanding the underlying genetic and molecular determinants related to maturation pathways of antiviral bnAbs that could be useful for applying novel approaches to the design of effective vaccine immunogens and antibody-based therapeutics.

  9. Commercially available antibodies against human and murine histamine H₄-receptor lack specificity.

    Science.gov (United States)

    Beermann, Silke; Seifert, Roland; Neumann, Detlef

    2012-02-01

    Antibodies are important tools to detect expression and localization of proteins within the living cell. However, for a series of commercially available antibodies which are supposed to recognize G-protein-coupled receptors (GPCR), lack of specificity has been described. In recent publications, antisera against the histamine H₄-receptor (H₄R), which is a member of the GPCR family, have been used to demonstrate receptor expression. However, a comprehensive characterization of these antisera has not been performed yet. Therefore, the purpose of our study was to evaluate the specificity of three commercially available H₄R antibodies. Sf9 insect cells and HEK293 cells expressing recombinant murine and human H₄R, spleen cells obtained from H₄⁻/⁻ and from wild-type mice, and human CD20⁺ and CD20⁻ peripheral blood cells were analyzed by flow cytometry and Western blot using three commercially available H₄R antibodies. Our results show that all tested H₄R antibodies bind to virtually all cells, independently of the expression of H₄R, thus in an unspecific fashion. Also in Western blot, the H₄R antibodies do not bind to the specified protein. Our data underscore the importance of stringent evaluation of antibodies using valid controls, such as cells of H₄R⁻/⁻ mice, to show true receptor expression and antigen specificity. Improved validation of commercially available antibodies prior to release to the market would avoid time-consuming and expensive validation assays by the user.

  10. Molluskan Hemocyanins Activate the Classical Pathway of the Human Complement System through Natural Antibodies

    Science.gov (United States)

    Pizarro-Bauerle, Javier; Maldonado, Ismael; Sosoniuk-Roche, Eduardo; Vallejos, Gerardo; López, Mercedes N.; Salazar-Onfray, Flavio; Aguilar-Guzmán, Lorena; Valck, Carolina; Ferreira, Arturo; Becker, María Inés

    2017-01-01

    Molluskan hemocyanins are enormous oxygen-carrier glycoproteins that show remarkable immunostimulatory properties when inoculated in mammals, such as the generation of high levels of antibodies, a strong cellular reaction, and generation of non-specific antitumor immune responses in some types of cancer, particularly for superficial bladder cancer. These proteins have the ability to bias the immune response toward a Th1 phenotype. However, despite all their current uses with beneficial clinical outcomes, a clear mechanism explaining these properties is not available. Taking into account reports of natural antibodies against the hemocyanin of the gastropod Megathura crenulata [keyhole limpet hemocyanin (KLH)] in humans as well as other vertebrate species, we report here for the first time, the presence, in sera from unimmunized healthy donors, of antibodies recognizing, in addition to KLH, two other hemocyanins from gastropods with documented immunomodulatory capacities: Fisurella latimarginata hemocyanin (FLH) and Concholepas concholepas hemocyanin (CCH). Through an ELISA screening, we found IgM and IgG antibodies reactive with these hemocyanins. When the capacity of these antibodies to bind deglycosylated hemocyanins was studied, no decreased interaction was detected. Moreover, in the case of FLH, deglycosylation increased antibody binding. We evaluated through an in vitro complement deposition assay whether these antibodies activated the classical pathway of the human complement system. The results showed that all three hemocyanins and their deglycosylated counterparts elicited this activation, mediated by C1 binding to immunoglobulins. Thus, this work contributes to the understanding on how the complement system could participate in the immunostimulatory properties of hemocyanins, through natural, complement-activating antibodies reacting with these proteins. Although a role for carbohydrates cannot be completely ruled out, in our experimental setting

  11. Development and characterization of human monoclonal antibodies that neutralize multiple TGFβ isoforms.

    Science.gov (United States)

    Bedinger, Daniel; Lao, Llewelyn; Khan, Shireen; Lee, Steve; Takeuchi, Toshihiko; Mirza, Amer M

    2016-01-01

    Transforming growth factor (TGF)β levels are elevated in, and drive the progression of, numerous disease states such as advanced metastatic cancer and systemic and ocular fibrosis. There are 3 main isoforms, TGFβ1, 2, and 3. As multiple TGFβ isoforms are involved in disease processes, maximal therapeutic efficacy may require neutralization of 2 or more of the TGFβ isoforms. Fully human antibody phage display libraries were used to discover a number of antibodies that bind and neutralize various combinations of TGFβ1, 2 or 3. The primary panning did not yield any uniformly potent pan-isoform neutralizing antibodies; therefore, an antibody that displayed potent TGFβ 1, 2 inhibition, but more modest affinity versus TGFβ3, was affinity matured by shuffling with a light chain sub-library and further screening. This process yielded a high affinity pan-isoform neutralizing clone. Antibodies were analyzed and compared by binding affinity, as well as receptor and epitope competition by surface plasmon resonance methods. The antibodies were also shown to neutralize TGFβ effects in vitro in 3 assays: 1) interleukin (IL)-4 induced HT-2 cell proliferation; 2) TGFβ-mediated IL-11 release by A549 cells; and 3) decreasing SMAD2 phosphorylation in Detroit 562 cells. The antibodies' potency in these in vitro assays correlated well with their isoform-specific affinities. Furthermore, the ability of the affinity-matured clone to decrease tumor burden in a Detroit 562 xenograft study was superior to that of the parent clone. This affinity-matured antibody acts as a very potent inhibitor of all 3 main isoforms of TGFβ and may have utility for therapeutic intervention in human disease.

  12. PREPARATION AND CHARACTERIZATION OF MONOCLONAL ANTIBODY AGAINST HUMAN TELOMERASE REVERSE TRANSCRIPTASE

    Institute of Scientific and Technical Information of China (English)

    王俊梅; 张波; 杨邵敏; 韩继生; 李冰思; 侯琳

    2003-01-01

    Objective. To develop monoclonal antibodies against the catalytic subunit of human telomerase reverse transcriptase (hTERT) for its expression detection of human tumors. Methods. A dominant epitope in hTERT (peptide hTERT7)was automatically synthesized based on Fmoc method, and was used to immunize Balb/c mice. Hybridomas were generated and screened by ELISA for specific monoclonal antibodies, and the characterization was performed by Western blotting and immunohistochemical staining. The heavy chain variable region of antibody was cloned by RT-PCR and sequenced. Results. Antigenic peptide hTERT7 was synthesized and confirmed by MALDI-TOF-MS and HPLC analysis. One hybridoma cell line secreting anti-hTERT7 antibodies designated as M2 was established after primary screening and consequent 3 rounds of limited dilution. M2 was IgG1 in isotyping. The competi tive assay showed that the M2 antibody was hTERT7 -specific, and the affinity constant was about 1×106 mol-1. The antibody reacted with cell extracts from HeLa cancer cells but not with those from normal 2BS cells in ELISA assay. For in situ staining of immunohistochemistry, the positive staining presented in the nuclear compartment of HeLa, while 2BS was negative. The heavy chain variable region from M2 re vealed that the monoclonal antibody was mouse origin. Conclusions. The developed mouse monoclonal antibody is hTERT-specific and able to recognize native cellular hTERT in ELISA and immunohistochemistry, which makes the immuno-detection of telom erase hTERT expression in cancer cells or tissues possible.

  13. Discrepancy between direct and antibody-dependent cytotoxic activities of human LAK cells.

    Science.gov (United States)

    Potapnev, M P; Garbuzenco, T S; Goncharova, N V; Zobnin, V D; Shadrin, O V; Bykovskaya, S N

    1994-06-01

    Human lymphokine-activated killer (LAK) cells display cytotoxic activity against natural killer (NK)-resistant tumor cells in an antibody-independent and -dependent manner. We compared LAK cell-mediated antibody-independent cytotoxicity (LAK activity) and antibody-dependent cellular cytotoxicity (ADCC) against untreated and antibody-coated Raji cells, respectively. Human lymphocytes showed drastically increased LAK activity after stimulation with interleukin-2 (IL-2) for 3 or 7 days when compared to non-activated cells. The level of ADCC was reduced for 3-day-generated LAK cells and augmented for 7-day-generated LAK cells as compared to non-activated cultured lymphocytes. Phenotypical analysis revealed IL-2-induced up-regulation of the proportion of CD11b+ (but not CD16+) lymphocyte subpopulation in 7-day-generated LAK cells. The data imply that human LAK cells exhibit antibody-dependent and -independent cytotoxic activities via distinct effector pathways at different stages of generation. These stages may be associated with changes in adhesion molecule (CD11b/CD18) expression on the surface of IL-2-activated lymphocytes.

  14. Viraemia suppressed in HIV-1-infected humans by broadly neutralizing antibody 3BNC117.

    Science.gov (United States)

    Caskey, Marina; Klein, Florian; Lorenzi, Julio C C; Seaman, Michael S; West, Anthony P; Buckley, Noreen; Kremer, Gisela; Nogueira, Lilian; Braunschweig, Malte; Scheid, Johannes F; Horwitz, Joshua A; Shimeliovich, Irina; Ben-Avraham, Sivan; Witmer-Pack, Maggi; Platten, Martin; Lehmann, Clara; Burke, Leah A; Hawthorne, Thomas; Gorelick, Robert J; Walker, Bruce D; Keler, Tibor; Gulick, Roy M; Fätkenheuer, Gerd; Schlesinger, Sarah J; Nussenzweig, Michel C

    2015-06-25

    HIV-1 immunotherapy with a combination of first generation monoclonal antibodies was largely ineffective in pre-clinical and clinical settings and was therefore abandoned. However, recently developed single-cell-based antibody cloning methods have uncovered a new generation of far more potent broadly neutralizing antibodies to HIV-1 (refs 4, 5). These antibodies can prevent infection and suppress viraemia in humanized mice and nonhuman primates, but their potential for human HIV-1 immunotherapy has not been evaluated. Here we report the results of a first-in-man dose escalation phase 1 clinical trial of 3BNC117, a potent human CD4 binding site antibody, in uninfected and HIV-1-infected individuals. 3BNC117 infusion was well tolerated and demonstrated favourable pharmacokinetics. A single 30 mg kg(-1) infusion of 3BNC117 reduced the viral load in HIV-1-infected individuals by 0.8-2.5 log10 and viraemia remained significantly reduced for 28 days. Emergence of resistant viral strains was variable, with some individuals remaining sensitive to 3BNC117 for a period of 28 days. We conclude that, as a single agent, 3BNC117 is safe and effective in reducing HIV-1 viraemia, and that immunotherapy should be explored as a new modality for HIV-1 prevention, therapy and cure.

  15. Identification of human nonpancreatic-type ribonuclease by antibodies obtained against a synthetic peptide.

    Science.gov (United States)

    Bravo, M I; Cuchillo, C M; Nogués, M V

    1995-09-01

    An antibody that recognizes human nonpancreatic-type ribonuclease was obtained by immunizing a rabbit with a 14-residue synthetic peptide corresponding to the N-terminal sequence of eosinophil-derived neurotoxin which is identical to human liver ribonuclease. This amino acid sequence is unique to this protein. The anti N-peptide antibody was purified by protein A-Sepharose and by using ELISA and SDS-PAGE immunoblot techniques, the antibody reactivity against EDN and partially purified nonpancreatic-type ribonucleases from human plasma and urine was observed. Cross-reactivity with bovine pancreatic ribonuclease A and other proteins was not detected. In addition, the activity of the nonpancreatic-type ribonuclease was not affected by the antibody. The immune response was elicited without the need for a carrier protein showing that the N-terminal sequence of nonpancreatic ribonuclease contains a specific epitope. This antibody can be used for the immunological identification of both the native and denatured forms of this type of enzyme.

  16. 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.

  17. A monoclonal antibody against leptin.

    Science.gov (United States)

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

    2012-10-01

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

  18. Human serum antibodies to a major defined epitope of human herpesvirus 8 small viral capsid antigen.

    Science.gov (United States)

    Tedeschi, R; De Paoli, P; Schulz, T F; Dillner, J

    1999-04-01

    The major antibody-reactive epitope of the small viral capsid antigen (sVCA) of human herpesvirus 8 (HHV-8) was defined by use of overlapping peptides. Strong IgG reactivity was found among approximately 50% of 44 human immunodeficiency virus-positive or -negative patients with Kaposi's sarcoma and 13 subjects who were seropositive by immunofluorescence assay (IFA) for the latent HHV-8 nuclear antigen. Only 1 of 106 subjects seronegative for both lytic and latent HHV-8 antigens and 10 of 81 subjects IFA-seropositive only for the lytic HHV-8 antigen had strong IgG reactivity to this epitope. Among 534 healthy Swedish women, only 1.3% were strongly seropositive. Comparison of the peptide-based and purified sVCA protein-based ELISAs found 55% sensitivity and 98% specificity. However, only 1 of 452 serum samples from healthy women was positive in both tests. In conclusion, the defined sVCA epitope was a specific, but not very sensitive, serologic marker of active HHV-8 infection. Such infection appears to be rare among Swedish women, even with sexual risk-taking behavior.

  19. Intravenous immunoglobulin prevents murine antibody-mediated acute lung injury at the level of neutrophil reactive oxygen species (ROS production.

    Directory of Open Access Journals (Sweden)

    John W Semple

    Full Text Available Transfusion-related acute lung injury (TRALI is a leading cause of transfusion-associated mortality that can occur with any type of transfusion and is thought to be primarily due to donor antibodies activating pulmonary neutrophils in recipients. Recently, a large prospective case controlled clinical study of cardiac surgery patients demonstrated that despite implementation of male donors, a high incidence of TRALI still occurred and suggested a need for additional interventions in susceptible patient populations. To examine if intravenous immunoglobulin (IVIg may be effective, a murine model of antibody-mediated acute lung injury that approximates human TRALI was examined. When BALB/c mice were injected with the anti-major histocompatibility complex class I antibody 34-1-2s, mild shock (reduced rectal temperature and respiratory distress (dyspnea were observed and pre-treatment of the mice with 2 g/kg IVIg completely prevented these symptoms. To determine IVIg's usefulness to affect severe lung damage, SCID mice, previously shown to be hypersensitive to 34-1-2s were used. SCID mice treated with 34-1-2s underwent severe shock, lung damage (increased wet/dry ratios and 40% mortality within 2 hours. Treatment with 2 g/kg IVIg 18 hours before 34-1-2s administration completely protected the mice from all adverse events. Treatment with IVIg after symptoms began also reduced lung damage and mortality. While the prophylactic IVIg administration did not affect 34-1-2s-induced pulmonary neutrophil accumulation, bone marrow-derived neutrophils from the IVIg-treated mice displayed no spontaneous ROS production nor could they be stimulated in vitro with fMLP or 34-1-2s. These results suggest that IVIg prevents murine antibody-mediated acute lung injury at the level of neutrophil ROS production and thus, alleviating tissue damage.

  20. Expression of recombinant antibodies.

    Science.gov (United States)

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

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

  1. Human anti-rhesus D IgG1 antibody produced in transgenic plants

    DEFF Research Database (Denmark)

    Bouquin, Thomas; Thomsen, Mads; Nielsen, Leif Kofoed

    2002-01-01

    antigen, which is responsible for alloimmunization of RhD- mothers carrying an RhD+ fetus. Anti-RhD extracted from plants specifically reacted with RhD+ cells in antiglobulin technique, and elicited a respiratory burst in human peripheral blood mononuclear cells. Plant-derived antibody had equivalent......Transgenic plants represent an alternative to cell culture systems for producing cheap and safe antibodies for diagnostic and therapeutic use. To evaluate the functional properties of a 'plantibody', we generated transgenic Arabidopsis plants expressing full-length human IgG1 against the Rhesus D...... properties to CHO cell-produced anti-RhD antibody, indicating its potential usefulness in diagnostic and therapeutic programs....

  2. The Complexity of a Dengue Vaccine: A Review of the Human Antibody Response.

    Directory of Open Access Journals (Sweden)

    Jacky Flipse

    Full Text Available Dengue is the most prevalent mosquito-borne viral disease worldwide. Yet, there are no vaccines or specific antivirals available to prevent or treat the disease. Several dengue vaccines are currently in clinical or preclinical stages. The most advanced vaccine is the chimeric tetravalent CYD-TDV vaccine of Sanofi Pasteur. This vaccine has recently cleared Phase III, and efficacy results have been published. Excellent tetravalent seroconversion was seen, yet the protective efficacy against infection was surprisingly low. Here, we will describe the complicating factors involved in the generation of a safe and efficacious dengue vaccine. Furthermore, we will discuss the human antibody responses during infection, including the epitopes targeted in humans. Also, we will discuss the current understanding of the assays used to evaluate antibody response. We hope this review will aid future dengue vaccine development as well as fundamental research related to the phenomenon of antibody-dependent enhancement of dengue virus infection.

  3. Distinct human antibody response to the biological warfare agent Burkholderia mallei.

    Science.gov (United States)

    Varga, John J; Vigil, Adam; DeShazer, David; Waag, David M; Felgner, Philip; Goldberg, Joanna B

    2012-10-01

    The genetic similarity between Burkholderia mallei (glanders) and Burkholderia pseudomallei (melioidosis) had led to the general assumption that pathogenesis of each bacterium would be similar. In 2000, the first human case of glanders in North America since 1945 was reported in a microbiology laboratory worker. Leveraging the availability of pre-exposure sera for this individual and employing the same well-characterized protein array platform that has been previously used to study a large cohort of melioidosis patients in southeast Asia, we describe the antibody response in a human with glanders. Analysis of 156 peptides present on the array revealed antibodies against 17 peptides with a > 2-fold increase in this infection. Unexpectedly, when the glanders data were compared with a previous data set from B. pseudomallei infections, there were only two highly increased antibodies shared between these two infections. These findings have implications in the diagnosis and treatment of B. mallei and B. pseudomallei infections.

  4. The Complexity of a Dengue Vaccine: A Review of the Human Antibody Response.

    Science.gov (United States)

    Flipse, Jacky; Smit, Jolanda M

    2015-01-01

    Dengue is the most prevalent mosquito-borne viral disease worldwide. Yet, there are no vaccines or specific antivirals available to prevent or treat the disease. Several dengue vaccines are currently in clinical or preclinical stages. The most advanced vaccine is the chimeric tetravalent CYD-TDV vaccine of Sanofi Pasteur. This vaccine has recently cleared Phase III, and efficacy results have been published. Excellent tetravalent seroconversion was seen, yet the protective efficacy against infection was surprisingly low. Here, we will describe the complicating factors involved in the generation of a safe and efficacious dengue vaccine. Furthermore, we will discuss the human antibody responses during infection, including the epitopes targeted in humans. Also, we will discuss the current understanding of the assays used to evaluate antibody response. We hope this review will aid future dengue vaccine development as well as fundamental research related to the phenomenon of antibody-dependent enhancement of dengue virus infection.

  5. Spleen vagal denervation inhibits the production of antibodies to circulating antigens.

    Directory of Open Access Journals (Sweden)

    Ruud M Buijs

    Full Text Available BACKGROUND: Recently the vagal output of the central nervous system has been shown to suppress the innate immune defense to pathogens. Here we investigated by anatomical and physiological techniques the communication of the brain with the spleen and provided evidence that the brain has the capacity to stimulate the production of antigen specific antibodies by its parasympathetic autonomic output. METHODOLOGY/PRINCIPAL FINDINGS: This conclusion was reached by successively demonstrating that: 1. The spleen receives not only sympathetic input but also parasympathetic input. 2. Intravenous trinitrophenyl-ovalbumin (TNP-OVA does not activate the brain and does not induce an immune response. 3. Intravenous TNP-OVA with an inducer of inflammation; lipopolysaccharide (LPS, activates the brain and induces TNP-specific IgM. 4. LPS activated neurons are in the same areas of the brain as those that provide parasympathetic autonomic information to the spleen, suggesting a feed back circuit between brain and immune system. Consequently we investigated the interaction of the brain with the spleen and observed that specific parasympathetic denervation but not sympathetic denervation of the spleen eliminates the LPS-induced antibody response to TNP-OVA. CONCLUSIONS/SIGNIFICANCE: These findings not only show that the brain can stimulate antibody production by its autonomic output, it also suggests that the power of LPS as adjuvant to stimulate antibody production may also depend on its capacity to activate the brain. The role of the autonomic nervous system in the stimulation of the adaptive immune response may explain why mood and sleep have an influence on antibody production.

  6. High prevalence of high risk human papillomavirus-capsid antibodies in human immunodeficiency virus-seropositive men: a serological study

    Directory of Open Access Journals (Sweden)

    Sarcletti Mario

    2003-04-01

    Full Text Available Abstract Background Serological study of human papillomavirus (HPV-antibodies in order to estimate the HPV-prevalence as risk factor for the development of HPV-associated malignancies in human immunodeficiency virus (HIV-positive men. Methods Sera from 168 HIV-positive men and 330 HIV-negative individuals (including 198 controls were tested using a direct HPV-ELISA specific to HPV-6, -11, -16, -18, -31 and bovine PV-1 L1-virus-like particles. Serological results were correlated with the presence of HPV-associated lesions, the history of other sexually transmitted diseases (STD and HIV classification groups. Results In HIV-negative men low risk HPV-antibodies were prevailing and associated with condylomatous warts (25.4%. Strikingly, HIV-positive men were more likely to have antibodies to the high-risk HPV types -16, -18, -31, and low risk antibodies were not increased in a comparable range. Even those HIV-positive heterosexual individuals without any HPV-associated lesions exhibited preferentially antibody responses to the oncogenic HPV-types (cumulative 31.1%. The highest antibody detection rate (88,8% was observed within the subgroup of nine HIV-positive homosexual men with anogenital warts. Three HIV-positive patients had HPV-associated carcinomas, in all of them HPV-16 antibodies were detected. Drug use and mean CD4-cell counts on the day of serologic testing had no influence on HPV-IgG antibody prevalence, as had prior antiretroviral therapy or clinical category of HIV-disease. Conclusion High risk HPV-antibodies in HIV-infected and homosexual men suggest a continuous exposure to HPV-proteins throughout the course of their HIV infection, reflecting the known increased risk for anogenital malignancies in these populations. The extensive increase of high risk antibodies (compared to low risk antibodies in HIV-positive patients cannot be explained by differences in exposure history alone, but suggests defects of the immunological control of

  7. In vitro anti-HIV-1 antibody production in subjects in different stages of HIV-1 infection.

    Science.gov (United States)

    Rusconi, S; Riva, A; Meroni, L; Zehender, G; Cocchi, F; Scapellato, L; Galli, M

    1995-01-01

    We evaluated the in vitro antibody production from peripheral blood mononuclear cells (PBMC) against HIV-1 proteins in infected adults. Fifty-four HIV-1 infected patients (four recent seroconverters, 15 asymptomatics with a CD4 count higher than 500/microliters, 27 asymptomatics with a CD4 count between 200 and 500/microliters and eight symptomatic patients) were tested. PBMC were incubated in the presence or absence of 1% pokeweed mitogen (PWM) at 37 degrees C for 8 days. Western blot assay, p24 antigen ELISA and anti-p24 antibody ELISA were performed on serum and culture supernatants. Spontaneous production of anti-env antibody in culture supernatants was evidenced in all subjects. All the positive supernatants for anti-core antibodies (18/54) were derived from asymptomatic patients. PBMC from recent seroconverters and from symptomatic patients did not produce any anti-core antibody. Antibody production decreased after stimulation with PWM. The concentration of p24 antigen did not significantly increase in p24 positive supernatants following acidification (P = 0.1), suggesting that the inability to detect p24 antibody was not due to the anti-p24 antibody complexed to p24 antigen in culture supernatants. In vitro production of anti-p24 antibodies was significantly more frequent in asymptomatic subjects with high CD4+ cell counts (P = 0.02) and was absent in recent seroconverters. This last finding suggests that during the initial phases of the infection, anti-p24 antibody production may be restricted to cells residing in lymphoid organs. In addition, the lower percentage of anti-core antibody in people with low CD4+ cell counts is not merely a consequence of the binding of the antibody to an increased amount of antigen, but probably reflects an impaired production or a sequestration of producing cells in lymphoid tissue during the late stages of the infection. PMID:7554395

  8. Cereal crops as viable production and storage systems for pharmaceutical scFv antibodies.

    Science.gov (United States)

    Stöger, E; Vaquero, C; Torres, E; Sack, M; Nicholson, L; Drossard, J; Williams, S; Keen, D; Perrin, Y; Christou, P; Fischer, R

    2000-03-01

    This report describes the stable expression of a medically important antibody in the staple cereal crops rice and wheat. We successfully expressed a single-chain Fv antibody (ScFvT84.66) against carcinoembryonic antigen (CEA), a well characterized tumor-associated marker antigen. scFv constructs were engineered for recombinant antibody targeting to the plant cell apoplast and ER. Up to 30 microg/g of functional recombinant antibody was detected in the leaves and seeds of wheat and rice. We confirmed that transgenic dry seeds could be stored for at least five months at room temperature, without significant loss of the amount or activity of scFvT84.66. Our results represent the first transition from model plant expression systems, such as tobacco and Arabidopsis, to widely cultivated cereal crops, such as rice and wheat, for expression of an antibody molecule that has already shown efficacy in clinical applications. Thus, we have established that molecular pharming in cereals can be a viable production system for such high-value pharmaceutical macromolecules. Our findings provide a strong foundation for exploiting alternative uses of cereal crops both in industrialized and developing countries.

  9. A genecentric Human Protein Atlas for expression profiles based on antibodies.

    Science.gov (United States)

    Berglund, Lisa; Björling, Erik; Oksvold, Per; Fagerberg, Linn; Asplund, Anna; Szigyarto, Cristina Al-Khalili; Persson, Anja; Ottosson, Jenny; Wernérus, Henrik; Nilsson, Peter; Lundberg, Emma; Sivertsson, Asa; Navani, Sanjay; Wester, Kenneth; Kampf, Caroline; Hober, Sophia; Pontén, Fredrik; Uhlén, Mathias

    2008-10-01

    An attractive path forward in proteomics is to experimentally annotate the human protein complement of the genome in a genecentric manner. Using antibodies, it might be possible to design protein-specific probes for a representative protein from every protein-coding gene and to subsequently use the antibodies for systematical analysis of cellular distribution and subcellular localization of proteins in normal and disease tissues. A new version (4.0) of the Human Protein Atlas has been developed in a genecentric manner with the inclusion of all human genes and splice variants predicted from genome efforts together with a visualization of each protein with characteristics such as predicted membrane regions, signal peptide, and protein domains and new plots showing the uniqueness (sequence similarity) of every fraction of each protein toward all other human proteins. The new version is based on tissue profiles generated from 6120 antibodies with more than five million immunohistochemistry-based images covering 5067 human genes, corresponding to approximately 25% of the human genome. Version 4.0 includes a putative list of members in various protein classes, both functional classes, such as kinases, transcription factors, G-protein-coupled receptors, etc., and project-related classes, such as candidate genes for cancer or cardiovascular diseases. The exact antigen sequence for the internally generated antibodies has also been released together with a visualization of the application-specific validation performed for each antibody, including a protein array assay, Western blot analysis, immunohistochemistry, and, for a large fraction, immunofluorescence-based confocal microscopy. New search functionalities have been added to allow complex queries regarding protein expression profiles, protein classes, and chromosome location. The new version of the protein atlas thus is a resource for many areas of biomedical research, including protein science and biomarker discovery.

  10. Production and characterization of monoclonal antibodies against rat platelet GPIIb/IIIa

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, H.; Tamura, S.; Sudo, T.; Suzuki, T. (Kirin Brewery Co., Ltd., Gunma (Japan))

    1990-09-15

    Four murine monoclonal antibodies against rat platelets were produced by fusion of spleen cells from mice intravenously immunized with whole rat platelets. All four antibodies immunoprecipitated two major platelet membrane proteins with apparent molecular weights of 130,000 and 82,000 (nonreduced) and of 120,000 and 98,000 (reduced), which were structurally analogous to human glycoprotein (GP) IIb/IIIa, i.e. rat GPIIb/IIIa. Two of four antibodies, named P9 and P55, strongly inhibited adenosine diphosphate (ADP)-induced aggregation of washed rat platelets and caused approximately 50% inhibition of human fibrinogen binding to ADP-stimulated rat platelets, suggesting that rat GPIIb/IIIa serves as a fibrinogen receptor in ADP-induced aggregation. In contrast, two other antibodies, named P14 and P34, themselves caused aggregation of rat platelets in platelet-rich plasma (PRP) and the secretion of 14C-serotonin from 14C-serotonin-labeled PRP. These results indicate that rat GPIIb/IIIa plays an important role in platelet aggregation.

  11. Fully Human VH Single Domains That Rival the Stability and Cleft Recognition of Camelid Antibodies.

    Science.gov (United States)

    Rouet, Romain; Dudgeon, Kip; Christie, Mary; Langley, David; Christ, Daniel

    2015-05-01

    Human VH single domains represent a promising class of antibody fragments with applications as therapeutic modalities. Unfortunately, isolated human VH domains also generally display poor biophysical properties and a propensity to aggregate. This has encouraged the development of non-human antibody domains as alternative means of antigen recognition and, in particular, camelid (VHH) domains. Naturally devoid of light chain partners, these domains are characterized by favorable biophysical properties and propensity for cleft binding, a highly desirable characteristic, allowing the targeting of cryptic epitopes. In contrast, previously reported structures of human VH single domains had failed to recapitulate this property. Here we report the engineering and characterization of phage display libraries of stable human VH domains and the selection of binders against a diverse set of antigens. Unlike "camelized" human domains, the domains do not rely on potentially immunogenic framework mutations and maintain the structure of the VH/VL interface. Structure determination in complex with hen egg white lysozyme revealed an extended VH binding interface, with complementarity-determining region 3 deeply penetrating into the active site cleft, highly reminiscent of what has been observed for camelid domains. Taken together, our results demonstrate that fully human VH domains can be constructed that are not only stable and well expressed but also rival the cleft binding properties of camelid antibodies.

  12. Detection of sulfur mustard adducts in human callus by phage antibodies

    NARCIS (Netherlands)

    Bikker, F.J.; Mars-Groenendijk, R.H.; Noort, D.; Fidder, A.; Schans, G.P. van der

    2007-01-01

    As part of a research program to develop novel methods for diagnosis of sulfur mustard exposure in the human skin the suitability of phage display was explored. Phage display is a relative new method that enables researchers to quickly evaluate a huge range of potentially useful antibodies, thereby

  13. Harnessing the immune system's arsenal: producing human monoclonal antibodies for therapeutics and investigating immune responses

    Science.gov (United States)

    Sullivan, Meghan; Kaur, Kaval; Pauli, Noel

    2011-01-01

    Monoclonal antibody technology has undergone rapid and innovative reinvention over the last 30 years. Application of these technologies to human samples revealed valuable therapeutic and experimental insights. These technologies, each with their own benefits and flaws, have proven indispensable for immunological research and in our fight to provide new treatments and improved vaccines for infectious disease. PMID:21876728

  14. B-1 cells and naturally occuring antibodies: influencing the immunogenicity of recombinant human therapeutic proteins

    NARCIS (Netherlands)

    Sauerborn, M.S.; Schellekens, H.

    2009-01-01

    Recombinant human therapeutic proteins are increasingly being used to treat serious and life-threatening diseases like multiple sclerosis, diabetes mellitus, and cancer. An important side effect of these proteins is the development of antidrug antibodies, which can be neutralizing and thus interfere

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

    DEFF Research Database (Denmark)

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

    1996-01-01

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

  16. Demonstration of immunoglobulin G in normal human epidermis by peroxidase-labeled antibody.

    Directory of Open Access Journals (Sweden)

    Yamada,Mariko

    1980-04-01

    Full Text Available Cytoplasmic immunoglobulin G (IgG in normal human epidermis was defined by a peroxidase-labeled antibody method. A correlation between cytoplasmic staining and the serum level of IgG was found. Epidermal cells containing IgG were not present when the serum level of IgG was less than 1000 microgram/ml.

  17. A novel polymorphism of human complement component C3 detected by means of a monoclonal antibody

    DEFF Research Database (Denmark)

    Koch, C; Behrendt, N

    1986-01-01

    A mouse monoclonal antibody, HAV 4-1, obtained after immunization of a BALB/c mouse with purified C3F, detected a novel genetic polymorphism of human complement component C3 in a simple immunoblotting system. The frequency of HAV 4-1-positive genes was 20.1%. Reactivity of HAV 4-1 was closely rel...

  18. The phase behavior study of human antibody solution using multi-scale modeling

    Science.gov (United States)

    Sun, Gang; Wang, Ying; Lomakin, Aleksey; Benedek, George B.; Stanley, H. Eugene; Xu, Limei; Buldyrev, Sergey V.

    2016-11-01

    Phase transformation in antibody solutions is of growing interest in both academia and the pharmaceutical industry. Recent experimental studies have shown that, as in near-spherical proteins, antibodies can undergo a liquid-liquid phase separation under conditions metastable with respect to crystallization. However, the phase diagram of the Y-shaped antibodies exhibits unique features that differ substantially from those of spherical proteins. Specifically, antibody solutions have an exceptionally low critical volume fraction (CVF) and a broader and more asymmetric liquid-liquid coexistence curve than those of spherical proteins. Using molecular dynamics simulation on a series of trimetric Y-shaped coarse-grained models, we investigate the phase behavior of antibody solutions and compare the results with the experimental phase diagram of human immunoglobulin G (IgG), one of the most common Y-shape typical of antibody molecules. With the fitted size of spheres, our simulation reproduces both the low CVF and the asymmetric shape of the experimental coexistence curve of IgG antibodies. The broadness of the coexistence curve can be attributed to the anisotropic nature of the inter-protein interaction. In addition, the repulsion between the inner parts of the spherical domains of IgG dramatically expands the coexistence region in the scaled phase diagram, while the hinge length has only a minor effect on the CVF and the overall shape of the coexistence curve. We thus propose a seven-site model with empirical parameters characterizing the exclusion volume and the hinge length of the IgG molecules, which provides a base for simulation studies of the phase behavior of IgG antibodies.

  19. A malaria vaccine that elicits in humans antibodies able to kill Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available BACKGROUND: Plasmodium falciparum merozoite surface protein 3 is a malaria vaccine candidate that was identified, characterised, and developed based on a unique immuno-clinical approach. The vaccine construct was derived from regions fully conserved among various strains and containing B cell epitopes targeted by human antibodies (from malaria-immune adults that are able to mediate a monocyte-dependent parasite killing effect. The corresponding long synthetic peptide was administered to 36 volunteers, with either alum or Montanide ISA720 as adjuvant. METHODS AND FINDINGS: Both formulations induced cellular and humoral immune responses. With alum, the responses lasted up to 12 mo. The vaccine-induced antibodies were predominantly of cytophilic classes, i.e., able to cooperate with effector cells. In vitro, the antibodies induced an inhibition of the P. falciparum erythrocytic growth in a monocyte-dependent manner, which was in most instances as high as or greater than that induced by natural antibodies from immune African adults. In vivo transfer of the volunteers' sera into P. falciparum-infected humanized SCID mice profoundly reduced or abrogated parasitaemia. These inhibitory effects were related to the antibody reactivity with the parasite native protein, which was seen in 60% of the volunteers, and remained in samples taken 12 mo postimmunisation. CONCLUSION: This is the first malaria vaccine clinical trial to clearly demonstrate antiparasitic activity by vaccine-induced antibodies by both in vitro and in vivo methods. The results, showing the induction of long-lasting antibodies directed to a fully conserved polypeptide, also challenge current concepts about malaria vaccines, such as unavoidable polymorphism, low antigenicity, and poor induction of immune memory.

  20. A malaria vaccine that elicits in humans antibodies able to kill Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Pierre Druilhe

    2005-11-01

    Full Text Available Plasmodium falciparum merozoite surface protein 3 is a malaria vaccine candidate that was identified, characterised, and developed based on a unique immuno-clinical approach. The vaccine construct was derived from regions fully conserved among various strains and containing B cell epitopes targeted by human antibodies (from malaria-immune adults that are able to mediate a monocyte-dependent parasite killing effect. The corresponding long synthetic peptide was administered to 36 volunteers, with either alum or Montanide ISA720 as adjuvant.Both formulations induced cellular and humoral immune responses. With alum, the responses lasted up to 12 mo. The vaccine-induced antibodies were predominantly of cytophilic classes, i.e., able to cooperate with effector cells. In vitro, the antibodies induced an inhibition of the P. falciparum erythrocytic growth in a monocyte-dependent manner, which was in most instances as high as or greater than that induced by natural antibodies from immune African adults. In vivo transfer of the volunteers' sera into P. falciparum-infected humanized SCID mice profoundly reduced or abrogated parasitaemia. These inhibitory effects were related to the antibody reactivity with the parasite native protein, which was seen in 60% of the volunteers, and remained in samples taken 12 mo postimmunisation.This is the first malaria vaccine clinical trial to clearly demonstrate antiparasitic activity by vaccine-induced antibodies by both in vitro and in vivo methods. The results, showing the induction of long-lasting antibodies directed to a fully conserved polypeptide, also challenge current concepts about malaria vaccines, such as unavoidable polymorphism, low antigenicity, and poor induction of immune memory.

  1. Serum anti-BPAG1 auto-antibody is a novel marker for human melanoma.

    Directory of Open Access Journals (Sweden)

    Takashi Shimbo

    Full Text Available Malignant melanoma is one of the most aggressive types of tumor. Because malignant melanoma is difficult to treat once it has metastasized, early detection and treatment are essential. The search for reliable biomarkers of early-stage melanoma, therefore, has received much attention. By using a novel method of screening tumor antigens and their auto-antibodies, we identified bullous pemphigoid antigen 1 (BPAG1 as a melanoma antigen recognized by its auto-antibody. BPAG1 is an auto-antigen in the skin disease bullous pemphigoid (BP and anti-BPAG1 auto-antibodies are detectable in sera from BP patients and are used for BP diagnosis. However, BPAG1 has been viewed as predominantly a keratinocyte-associated protein and a relationship between BPAG1 expression and melanoma has not been previously reported. In the present study, we show that bpag1 is expressed in the mouse F10 melanoma cell line in vitro and F10 melanoma tumors in vivo and that BPAG1 is expressed in human melanoma cell lines (A375 and G361 and normal human melanocytes. Moreover, the levels of anti-BPAG1 auto-antibodies in the sera of melanoma patients were significantly higher than in the sera of healthy volunteers (p<0.01. Furthermore, anti-BPAG1 auto-antibodies were detected in melanoma patients at both early and advanced stages of disease. Here, we report anti-BPAG1 auto-antibodies as a promising marker for the diagnosis of melanoma, and we discuss the significance of the detection of such auto-antibodies in cancer biology and patients.

  2. Antibodies against Human Cytomegalovirus in the Pathogenesis of Systemic Sclerosis: A Gene Array Approach.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available BACKGROUND: Systemic sclerosis is an autoimmune disease characterized by immunological abnormalities, vascular damage, and fibroblast proliferation. We have previously shown that a molecular mimicry mechanism links antibodies against the human-cytomegalovirus-derived protein UL94 to the pathogenesis of systemic sclerosis. The UL94 epitope shows homology with NAG-2, a surface molecule highly expressed on endothelial cells. Anti-UL94 peptide antibodies purified from patients' sera induce apoptosis of endothelial cells upon engagement of the NAG-2-integrin complex. METHODS AND FINDINGS: We show here that NAG-2 is expressed on dermal fibroblasts and that anti-UL94 antibodies bind to fibroblasts. We have used the gene array strategy (Affimetrix oligonucleotide microarrays to analyze the transcriptional profile in response to a 4-h and an 8-h treatment with antibodies against the UL94 peptide in endothelial cells and dermal fibroblasts. Exposure of endothelial cells to anti-UL94 antibodies had a profound impact on gene expression, resulting in the upregulation of 1,645 transcripts. Several gene clusters were upregulated including genes encoding adhesion molecules, chemokines, colony-stimulating factors (CSFs, growth factors, and molecules involved in apoptosis. Following antibody stimulation, dermal fibroblasts showed an upregulation of 989 transcripts and acquired a "scleroderma-like" phenotype. Indeed, genes involved in extracellular matrix deposition, growth factors, chemokines, and cytokines were upregulated. We confirmed the microarray results by real-time quantitative polymerase chain reaction and by measuring some of the corresponding proteins with ELISA and Western blotting. CONCLUSION: Our results show that anti-human-cytomegalovirus antibodies may be linked to the pathogenesis of systemic sclerosis not only by inducing endothelial cell activation and apoptosis but also by causing activation of fibroblasts, one of the hallmarks of the disease.

  3. Antibodies against human cytomegalovirus in the pathogenesis of systemic sclerosis: a gene array approach.

    Directory of Open Access Journals (Sweden)

    Claudio Lunardi

    2006-01-01

    Full Text Available BACKGROUND: Systemic sclerosis is an autoimmune disease characterized by immunological abnormalities, vascular damage, and fibroblast proliferation. We have previously shown that a molecular mimicry mechanism links antibodies against the human-cytomegalovirus-derived protein UL94 to the pathogenesis of systemic sclerosis. The UL94 epitope shows homology with NAG-2, a surface molecule highly expressed on endothelial cells. Anti-UL94 peptide antibodies purified from patients' sera induce apoptosis of endothelial cells upon engagement of the NAG-2-integrin complex. METHODS AND FINDINGS: We show here that NAG-2 is expressed on dermal fibroblasts and that anti-UL94 antibodies bind to fibroblasts. We have used the gene array strategy (Affimetrix oligonucleotide microarrays to analyze the transcriptional profile in response to a 4-h and an 8-h treatment with antibodies against the UL94 peptide in endothelial cells and dermal fibroblasts. Exposure of endothelial cells to anti-UL94 antibodies had a profound impact on gene expression, resulting in the upregulation of 1,645 transcripts. Several gene clusters were upregulated including genes encoding adhesion molecules, chemokines, colony-stimulating factors (CSFs, growth factors, and molecules involved in apoptosis. Following antibody stimulation, dermal fibroblasts showed an upregulation of 989 transcripts and acquired a "scleroderma-like" phenotype. Indeed, genes involved in extracellular matrix deposition, growth factors, chemokines, and cytokines were upregulated. We confirmed the microarray results by real-time quantitative polymerase chain reaction and by measuring some of the corresponding proteins with ELISA and Western blotting. CONCLUSION: Our results show that anti-human-cytomegalovirus antibodies may be linked to the pathogenesis of systemic sclerosis not only by inducing endothelial cell activation and apoptosis but also by causing activation of fibroblasts, one of the hallmarks of the disease.

  4. Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Britton, W.J.; Hellqvist, L.; Basten, A.; Raison, R.L.

    1985-12-01

    Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bands of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae.

  5. Pathogen-specific deep sequence-coupled biopanning: A method for surveying human antibody responses

    Science.gov (United States)

    Pascale, Juan M.; Moreno, Brechla; Chackerian, Bryce; Peabody, David S.

    2017-01-01

    Identifying the targets of antibody responses during infection is important for designing vaccines, developing diagnostic and prognostic tools, and understanding pathogenesis. We developed a novel deep sequence-coupled biopanning approach capable of identifying the protein epitopes of antibodies present in human polyclonal serum. Here, we report the adaptation of this approach for the identification of pathogen-specific epitopes recognized by antibodies elicited during acute infection. As a proof-of-principle, we applied this approach to assessing antibodies to Dengue virus (DENV). Using a panel of sera from patients with acute secondary DENV infection, we panned a DENV antigen fragment library displayed on the surface of bacteriophage MS2 virus-like particles and characterized the population of affinity-selected peptide epitopes by deep sequence analysis. Although there was considerable variation in the responses of individuals, we found several epitopes within the Envelope glycoprotein and Non-Structural Protein 1 that were commonly enriched. This report establishes a novel approach for characterizing pathogen-specific antibody responses in human sera, and has future utility in identifying novel diagnostic and vaccine targets. PMID:28152075

  6. A human PrM antibody that recognizes a novel cryptic epitope on dengue E glycoprotein.

    Science.gov (United States)

    Chan, Annie Hoi Yi; Tan, Hwee Cheng; Chow, Angelia Yee; Lim, Angeline Pei Chiew; Lok, Shee Mei; Moreland, Nicole J; Vasudevan, Subhash G; MacAry, Paul A; Ooi, Eng Eong; Hanson, Brendon J

    2012-01-01

    Dengue virus (DENV) is a major mosquito-borne pathogen infecting up to 100 million people each year; so far no effective treatment or vaccines are available. Recently, highly cross-reactive and infection-enhancing pre-membrane (prM)-specific antibodies were found to dominate the anti-DENV immune response in humans, raising concern over vaccine candidates that contain native dengue prM sequences. In this study, we have isolated a broadly cross-reactive prM-specific antibody, D29, during a screen with a non-immunized human Fab-phage library against the four serotypes of DENV. The antibody is capable of restoring the infectivity of virtually non-infectious immature DENV (imDENV) in FcγR-bearing K562 cells. Remarkably, D29 also cross-reacted with a cryptic epitope on the envelope (E) protein located to the DI/DII junction as evidenced by site-directed mutagenesis. This cryptic epitope, while inaccessible to antibody binding in a native virus particle, may become exposed if E is not properly folded. These findings suggest that generation of anti-prM antibodies that enhance DENV infection may not be completely avoided even with immunization strategies employing E protein alone or subunits of E proteins.

  7. Hypogammaglobulinemia in BLT humanized mice--an animal model of primary antibody deficiency.

    Directory of Open Access Journals (Sweden)

    Francisco Martinez-Torres

    Full Text Available Primary antibody deficiencies present clinically as reduced or absent plasma antibodies without another identified disorder that could explain the low immunoglobulin levels. Bone marrow-liver-thymus (BLT humanized mice also exhibit primary antibody deficiency or hypogammaglobulinemia. Comprehensive characterization of B cell development and differentiation in BLT mice revealed other key parallels with primary immunodeficiency patients. We found that B cell ontogeny was normal in the bone marrow of BLT mice but observed an absence of switched memory B cells in the periphery. PC-KLH immunizations led to the presence of switched memory B cells in immunized BLT mice although plasma cells producing PC- or KLH- specific IgG were not detected in tissues. Overall, we have identified the following parallels between the humoral immune systems of primary antibody deficiency patients and those in BLT mice that make this in vivo model a robust and translational experimental platform for gaining a greater understanding of this heterogeneous array of humoral immunodeficiency disorders in humans: (i hypogammaglobulinemia; (ii normal B cell ontogeny in bone marrow; and (iii poor antigen-specific IgG response to immunization. Furthermore, the development of strategies to overcome these humoral immune aberrations in BLT mice may in turn provide insights into the pathogenesis of some primary antibody deficiency patients which could lead to novel clinical interventions for improved humoral immune function.

  8. Class specific antibody responses to newborn larva antigens during Trichinella spiralis human infection

    Directory of Open Access Journals (Sweden)

    Mendez-Loredo B.

    2001-06-01

    Full Text Available A follow-up study of the class antibody responses to newborn larva (NBL antigens in individuals involved in an outbreak of human trichinellosis was carried out by ELISA assays. The data showed that similar kinetics of antibody responses of different magnitude developed in trichinellosis patients; it was low by week 3, a peak raised by week 5 and decreased from week 7 up to the end of the study. The IgA-ELISA assay was the most sensitive and specific while the IgM was the least sensitive and specific. IgA antibodies to NBL antigens were detected in 80 % of patients while IgE, IgG and IgM responses were observed in 44, 31 and 19 % of the patients by week 3, respectively. From weeks 5 to 7, IgA antibodies were found in 89 to 100 % of the patients while lower percentages (0-82 % were found for the other isotypes. Reactivity of IgA, IgE, IgG and IgM to NBL antigens decreased from week 37 to 57 after infection (0-38 %. These results suggest that detection of IgA antibodies may be useful for early diagnosis and epidemiological studies in human trichinellosis.

  9. Characterization of a novel inhibitory human monoclonal antibody directed against Plasmodium falciparum Apical Membrane Antigen 1.

    Science.gov (United States)

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

    2016-12-21

    Malaria remains a major challenge to global health causing extensive morbidity and mortality. Yet, there is no efficient vaccine and the immune response remains incompletely understood. Apical Membrane Antigen 1 (AMA1), a leading vaccine candidate, plays a key role during merozoite invasion into erythrocytes by interacting with Rhoptry Neck Protein 2 (RON2). We generated a human anti-AMA1-antibody (humAbAMA1) by EBV-transformation of sorted B-lymphocytes from a Ghanaian donor and subsequent rescue of antibody variable regions. The antibody was expressed in Nicotiana benthamiana and in HEK239-6E, characterized for binding specificity and epitope, and analyzed for its inhibitory effect on Plasmodium falciparum. The generated humAbAMA1 shows an affinity of 106-135 pM. It inhibits the parasite strain 3D7A growth in vitro with an expression system-independent IC50-value of 35 μg/ml (95% confidence interval: 33 μg/ml-37 μg/ml), which is three to eight times lower than the IC50-values of inhibitory antibodies 4G2 and 1F9. The epitope was mapped to the close proximity of the RON2-peptide binding groove. Competition for binding between the RON2-peptide and humAbAMA1 was confirmed by surface plasmon resonance spectroscopy measurements. The particularly advantageous inhibitory activity of this fully human antibody might provide a basis for future therapeutic applications.

  10. Generation and characterization of the human neutralizing antibody fragment Fab091 against rabies virus

    Institute of Scientific and Technical Information of China (English)

    Chen LI; Feng ZHANG; Hong LIN; Zhong-can WANG; Xin-jian LIU; Zhen-qing FENG; Jin ZHU; Xiao-hong GUAN

    2011-01-01

    Aim: To transform the human anti-rabies virus glycoprotein (anti-RABVG) single-chain variable fragment (scFv) into a Fab fragment and to analyze its immunological activity.Methods: The Fab gene was amplified using overlap PCR and inserted into the vector pComb3XSS. The recombinant vector was then transformed into E coli Top10F' for expression and purification. The purified Fab was characterized using SDS-PAGE, Western blotting,indirect ELISA, competitive ELISA, and the fluorescent antibody virus neutralization test (FAVN), respectively, and examined in a Kunming mouse challenge model in vivo.Results: A recombinant vector was constructed. The Fab was expressed in soluble form In E coll Top10F'. Specific binding of the Fab to rabies virus was confirmed by indirect ELISA and immunoprecipitation (IP). The neutralizing antibody titer of Fab was 10.26 IU/mL.The mouse group treated with both vaccine and human rabies immunoglobulin (HRIG)/Fab091 (32 IU/kg) showed protection against rabies, compared with the control group (P<0.05, Logrank test).Conclusion: The antibody fragment Fab was shown to be a neutralizing antibody against RABVG. It can be used together with other monoclonal antibodies for post-exposure prophylaxis of rabies virus in future studies.

  11. Age-related reduction of antibody response against the human endogenous retrovirus K envelope in women.

    Science.gov (United States)

    Kim, Hyoung Jin; Moon, Byung-In; Lee, Jun Woo; Kim, Seung Cheol; Kim, Hong-Jin

    2016-04-05

    In the present study, the correlation between the antibody response against human endogenous retrovirus K (HERV-K) envelope and human age was investigated. Antibody levels were compared in groups in their 20s (n = 25), 30s (n = 39), 40s (n = 68), 50s (n = 32), and 60s and over (n = 25), which included healthy individuals and breast cancer and/or cervical cancer patients. It appeared that both IgM and IgG responses against the HERV-K envelope fell with increasing age. There were no differences in anti-HERV-K envelope antibody levels between healthy individuals and cancer patients. Therefore, our results indicated that the anti-HERV-K antibody levels cannot be considered as cancer-specific marker. Also, IgG1 appeared to be the predominant subtype in the reduction of the IgG response by age. Receiver operating characteristic curves of anti-HERV-K envelope IgM levels indicated that the groups of people in their 20s or 30s could be distinguished from those in their 40s, 50s or 60s and over with satisfactory sensitivity and specificity. These findings indicate that the serum antibody level of HERV-K envelope is a critical parameter reflecting person's age.

  12. Generation and characterization of recombinant human antibodies specific for native laminin epitopes. Potential application in cancer therapy. Cancer Immunol. Immunother

    DEFF Research Database (Denmark)

    Sanz, Laura; Kristensen, Peter; Russell, Stephen J.

    2001-01-01

    of human-derived antibody fragments able to modulate laminin-regulated biological functions would allow the development of new strategies to improve treatment of cancer patients. In this report, we explore the use of phage display technology to isolate human anti-laminin antibody fragments. A library...

  13. Construction of a human recombinant polyclonal Fab fragment antibody library using peripheral blood lymphocytes of snake bitten victims

    Directory of Open Access Journals (Sweden)

    Motedayen, M.H.

    2015-12-01

    Full Text Available Human snake bitten poisoning is a serious threat in many tropical and subtropical countries such as Iran. The best acceptable treatment of envenomated humans is antivenoms; however they have a series of economic and medical problems and need more improvements. In this study a combinatorial human immunoglobulin gene library against some of Iranian snakes venoms was constructed. Total RNA prepared from peripheral blood lymphocytes of two recovered snake victims. RT-PCR was used for cDNA synthesis and amplification of the heavy (Fd segment and kappa light chains of IgG antibody. After digestion of the heavy chain with SpeI and XhoI and light chain with XbaI and SacI enzymes, inserted successively into the cloning vector pComb3x, and then recombinant vector transformed to TG1 bacteria to construct the Fab library. For determination insertion rate of Fab segment into cloning vector, plasmids of 12 clones of library were extracted and digested with SfiI. Length of amplified Fd and κ chains, were 650 - 750 bp. Primary library size was determined to contain 4.9×105 members out of which half of them contained the same size of Fab fragment. This result is comparable to some researchers and shows that this method could be appropriate tool for the production of human polyclonal Fab fragment antibodies for management of poisonous snake bitted victims.

  14. Prevalence of hepatitis C Antibody in Human Immunodeficiency ...

    African Journals Online (AJOL)

    2015-10-25

    Oct 25, 2015 ... impacts on the course and man- agement ... cause of the increased incidence and accelerated natural history in co-infected persons.4HCV infection may also impact the ... Hepatitis C virus (HCV) and Human Immunodeficiency .... 8 (88.9). 1 (33.3). 2.67. 0.83 – 33.18. Anti-HCV positive. N u m b er p ositive.

  15. Diagnosis of human African trypanosomiasis and visceral leishmaniasis based on the detection of anti-parasite-enzyme antibodies.

    Science.gov (United States)

    Borowy, N K; Schell, D; Schäfer, C; Overath, P

    1991-08-01

    A sensitive diagnostic assay for parasitic infections based on the detection of anti-enzyme antibodies is presented. All serum antibodies produced in response to parasite antigens are immobilized via their Fc domain on matrix-bound protein G. Incubation of the immobilized antibodies with saturating amounts of parasite extract results in the binding of all recognized antigens, including those directed against a specific and readily measurable enzyme. The amount of bound enzyme is proportional to the anti-enzyme antibody concentration in the serum. The application of this principle is demonstrated for the diagnosis of both human African trypanosomiasis and visceral leishmaniasis by the detection of antibodies against parasite acid phosphatases.

  16. Antibody response to recombinant human coagulation factor VIII in a new rat model of severe hemophilia A

    DEFF Research Database (Denmark)

    Löfgren, Karin Maria; Sondergaard, H.; Skov, Søren

    2016-01-01

    studies,antibodies developed after 4–6 administrations ofrhFVIII, and neutralizing antibodies reached levels simi-lar to human patients (range 1–111 BU, median 6.0 BU)at the end of the study. There was no significant differ-ence between the two studies or between genotypes intime to response or levels...... reached for binding and neu-tralizing antibodies. Interestingly, early spontaneousbleeds were associated with a faster antibody response. Conclusions: Following intravenous administration ofhuman FVIII, according to a clinical prophylaxis regi-men, a robust and reproducible antibody response is seenin...

  17. Source and Purity of Dengue-Viral Preparations Impact Requirement for Enhancing Antibody to Induce Elevated IL-1β Secretion: A Primary Human Monocyte Model.

    Directory of Open Access Journals (Sweden)

    Justin B Callaway

    Full Text Available Dengue virus is a major global health threat and can lead to life-threatening hemorrhagic complications due to immune activation and cytokine production. Cross-reactive antibodies to an earlier dengue virus infection are a recognized risk factor for severe disease. These antibodies bind heterologous dengue serotypes and enhance infection into Fc-receptor-bearing cells, a process known as antibody-dependent enhancement of infection. One crucial cytokine seen elevated in severe dengue patients is IL-1β, a potent inflammatory cytokine matured by the inflammasome. We used a highly-physiologic system by studying antibody-dependent enhancement of IL-1β in primary human monocytes with anti-dengue human monoclonal antibodies isolated from patients. Antibody-enhancement increased viral replication in primary human monocytes inoculated with supernatant harvested from Vero cells infected with dengue virus serotype 2 (DENV-2 16681. Surprisingly, IL-1β secretion induced by infectious supernatant harvested from two independent Vero cell lines was not enhanced by antibody. Secretion of multiple other inflammatory cytokines was also independent of antibody signaling. However, IL-1β secretion did require NLRP3 and caspase-1 activity. Immunodepletion of dengue virions from the infectious supernatant confirmed that virus was not the main IL-1β-inducing agent, suggesting that a supernatant component(s not associated with the virion induced IL-1β production. We excluded RNA, DNA, contaminating LPS, viral NS1 protein, complement, and cytokines. In contrast, purified Vero-derived DENV-2 16681 exhibited antibody-enhancement of both infection and IL-1β induction. Furthermore, C6/36 mosquito cells did not produce such an inflammatory component, as crude supernatant harvested from insect cells infected with DENV-2 16681 induced antibody-dependent IL-1β secretion. This study indicates that Vero cells infected with DENV-2 16681 may produce inflammatory components

  18. Source and Purity of Dengue-Viral Preparations Impact Requirement for Enhancing Antibody to Induce Elevated IL-1β Secretion: A Primary Human Monocyte Model.

    Science.gov (United States)

    Callaway, Justin B; Smith, Scott A; Widman, Douglas G; McKinnon, Karen P; Scholle, Frank; Sempowski, Gregory D; Dittmer, Dirk P; Crowe, James E; de Silva, Aravinda M; Ting, Jenny P-Y

    2015-01-01

    Dengue virus is a major global health threat and can lead to life-threatening hemorrhagic complications due to immune activation and cytokine production. Cross-reactive antibodies to an earlier dengue virus infection are a recognized risk factor for severe disease. These antibodies bind heterologous dengue serotypes and enhance infection into Fc-receptor-bearing cells, a process known as antibody-dependent enhancement of infection. One crucial cytokine seen elevated in severe dengue patients is IL-1β, a potent inflammatory cytokine matured by the inflammasome. We used a highly-physiologic system by studying antibody-dependent enhancement of IL-1β in primary human monocytes with anti-dengue human monoclonal antibodies isolated from patients. Antibody-enhancement increased viral replication in primary human monocytes inoculated with supernatant harvested from Vero cells infected with dengue virus serotype 2 (DENV-2) 16681. Surprisingly, IL-1β secretion induced by infectious supernatant harvested from two independent Vero cell lines was not enhanced by antibody. Secretion of multiple other inflammatory cytokines was also independent of antibody signaling. However, IL-1β secretion did require NLRP3 and caspase-1 activity. Immunodepletion of dengue virions from the infectious supernatant confirmed that virus was not the main IL-1β-inducing agent, suggesting that a supernatant component(s) not associated with the virion induced IL-1β production. We excluded RNA, DNA, contaminating LPS, viral NS1 protein, complement, and cytokines. In contrast, purified Vero-derived DENV-2 16681 exhibited antibody-enhancement of both infection and IL-1β induction. Furthermore, C6/36 mosquito cells did not produce such an inflammatory component, as crude supernatant harvested from insect cells infected with DENV-2 16681 induced antibody-dependent IL-1β secretion. This study indicates that Vero cells infected with DENV-2 16681 may produce inflammatory components during dengue virus

  19. Tocilizumab, a humanized anti-interleukin-6 receptor antibody, for treatment of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Masahiko Mihara

    2011-02-01

    Full Text Available Masahiko Mihara1, Yoshiyuki Ohsugi2, Tadamitsu Kishimoto31Product Research Department, Chugai Pharmaceutical Co Ltd, Fuji-Gotemba Research Laboratories, Shizuoka, Japan; 2Chugai Pharmaceutical Co Ltd, Tokyo, Japan; 3Laboratory of Immunoregulation, Graduate School of Frontier Biosciences, Osaka University, Osaka, JapanAbstract: Interleukin (IL-6 has a variety of biological functions. For example, it stimulates the production of acute-phase reactants (C-reactive protein and serum amyloid A and hepcidin which interferes with iron recycling and absorption, causing iron-deficient anemia, and augments expression of vascular endothelial growth factor and receptor activator of nuclear factor-κB ligand in synovial cells, leading to neovascularization and osteoclast formation. IL-6 also acts on lymphocytes, not only on B cells to stimulate autoantibody production, but also on naïve T helper cells to promote Th17 cell differentiation. Thus, an imbalance between T cell subsets possibly contributes to development of rheumatoid arthritis. Several clinical studies have demonstrated that a humanized anti-IL-6 receptor antibody, tocilizumab, improves clinical symptoms in rheumatoid arthritis. Tocilizumab prevented radiographic progression of joint destruction by inhibiting cartilage/bone resorption. Tocilizumab also improved hematological abnormalities, including hypergammaglobulinemia, high levels of autoantibodies, and elevation of erythrocyte sedimentation rate and acute-phase proteins. Importantly, tocilizumab improved quality of life by reducing systemic symptoms, including fatigue, anemia, anorexia, and fever. These findings have confirmed that hyperproduction of IL-6 is responsible for the above clinical symptoms, including joint destruction. Many patients treated with tocilizumab achieved clinical remission associated with decreased serum IL-6, suggesting that IL-6 enhances autoimmunity. Tocilizumab is a new therapeutic option for rheumatoid arthritis

  20. Development of novel monoclonal antibodies against starch and ulvan - Implications for antibody production against polysaccharides with limited immunogenicity

    DEFF Research Database (Denmark)

    Rydahl, Maja Gro; Kračun, Stjepan K.; Fangel, Jonatan U.

    2017-01-01

    Monoclonal antibodies (mAbs) are widely used and powerful research tools, but the generation of mAbs against glycan epitopes is generally more problematic than against proteins. This is especially significant for research on polysaccharide-rich land plants and algae (Viridiplantae). Most antibody...

  1. 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...... 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...

  2. 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...... 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...

  3. A radiomicroassay for cytotoxic antibody to human spermatozoa. Quantification by tritiated actinomycin d.

    Science.gov (United States)

    Sung, J S; Shizuya, H; Black, D D; Mumford, D M

    1977-03-01

    A radiomicroassay for titration of spermocytotoxic antibody is described. The assay used [3H]AACTINOMYCIN D ([3H]Act D) to label damaged spermatozoa in a fashion analogous to penetration by vital dye. Optimal conditions for and some kinetics of the assay are presented. The assay is sensitive, reliable, simple to perform and uses only small amounts of serum and spermatozoa. Applied to sperm antibody positive human postvasectomy sera, the assay compared favourably in sensitivity eith vital dye microscopic observations and with parallel titration by the Isojima's immobilization tests.

  4. Detection of diphtheria toxin antibodies in human sera in New Zealand by ELISA.

    OpenAIRE

    Lau, R. C.

    1986-01-01

    An enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG antibodies to diphtheria toxin in human serum. Serum samples obtained from 557 normal persons aged 1-65 years from different areas in New Zealand showed maximum antibody levels in the 1-9 years age group (95.1%) and the least in the 60-65 years age group (38.1%). The indirect ELISA is suitable for seroepidemiological survey study as it is simple to perform, economical and precise.

  5. Co-Incubation of Human Spermatozoa with Anti-VDAC Antibody Reduced Sperm Motility

    Directory of Open Access Journals (Sweden)

    Bianjiang Liu

    2014-01-01

    Full Text Available Background: Voltage-dependent anion channel (VDAC, a channel protein, exists in the outer mitochondrial membrane of somatic cells and is involved in multiple physiological and pathophysiological processes. Up until now, little has been known about VDAC in male germ cells. In the present study, the relationship between VDAC and human sperm motility was explored. Methods: Highly motile human spermatozoa were incubated in vitro with anti-VDAC antibody. Total sperm motility, straight line velocity (VSL, curvilinear velocity (VCL, and average path velocity (VAP were recorded. Intracellular free calcium concentration ([Ca2+]i, pH value (pHi, and ATP content were determined. Results: Co-incubation with anti-VDAC antibody reduced VSL, VCL, and VAP of spermatozoa. Co-incubation further reduced [Ca2+]i. Anti-VDAC antibody did not significantly alter total sperm motility, pHi and intracellular ATP content. Conclusion: The data suggest that co-incubation with anti-VDAC antibody reduces sperm motility through inhibition of Ca2+ transmembrane flow. In this way, VDAC participates in the modulation of human sperm motility through mediating Ca2+ transmembrane transport and exchange.

  6. Development of a human IgG4 bispecific antibody for dual targeting of interleukin-4 (IL-4) and interleukin-13 (IL-13) cytokines.

    Science.gov (United States)

    Spiess, Christoph; Bevers, Jack; Jackman, Janet; Chiang, Nancy; Nakamura, Gerald; Dillon, Michael; Liu, Hongbin; Molina, Patricia; Elliott, J Michael; Shatz, Whitney; Scheer, Justin M; Giese, Glen; Persson, Josefine; Zhang, Yin; Dennis, Mark S; Giulianotti, James; Gupta, Prateek; Reilly, Dorothea; Palma, Enzo; Wang, Jianyong; Stefanich, Eric; Scheerens, Heleen; Fuh, Germaine; Wu, Lawren C

    2013-09-13

    Human bispecific antibodies have great potential for the treatment of human diseases. Although human IgG1 bispecific antibodies have been generated, few attempts have been reported in the scientific literature that extend bispecific antibodies to other human antibody isotypes. In this paper, we report our work expanding the knobs-into-holes bispecific antibody technology to the human IgG4 isotype. We apply this approach to generate a bispecific antibody that targets IL-4 and IL-13, two cytokines that play roles in type 2 inflammation. We show that IgG4 bispecific antibodies can be generated in large quantities with equivalent efficiency and quality and have comparable pharmacokinetic properties and lung partitioning, compared with the IgG1 isotype. This work broadens the range of published therapeutic bispecific antibodies with natural surface architecture and provides additional options for the generation of bispecific antibodies with differing effector functions through the use of different antibody isotypes.

  7. Recombinant Protein Truncation Strategy for Inducing Bactericidal Antibodies to the Macrophage Infectivity Potentiator Protein of Neisseria meningitidis and Circumventing Potential Cross-Reactivity with Human FK506-Binding Proteins

    OpenAIRE

    Bielecka, Magdalena K.; Devos, Nathalie; Gilbert, Mélanie; Hung, Miao-Chiu; Weynants, Vincent; Heckels, John E.; Christodoulides, Myron

    2014-01-01

    A recombinant macrophage infectivity potentiator (rMIP) protein of Neisseria meningitidis induces significant serum bactericidal antibody production in mice and is a candidate meningococcal vaccine antigen. However, bioinformatics analysis of MIP showed some amino acid sequence similarity to human FK506-binding proteins (FKBPs) in residues 166 to 252 located in the globular domain of the protein. To circumvent the potential concern over generating antibodies that could recognize human protein...

  8. A novel human-derived antibody against NY-ESO-1 improves the efficacy of chemotherapy.

    Science.gov (United States)

    Gupta, Anurag; Nuber, Natko; Esslinger, Christoph; Wittenbrink, Mareike; Treder, Martin; Landshammer, Alexandro; Noguchi, Takuro; Kelly, Marcus; Gnjatic, Sacha; Ritter, Erika; von Boehmer, Lotta; Nishikawa, Hiroyoshi; Shiku, Hiroshi; Old, Lloyd; Ritter, Gerd; Knuth, Alexander; van den Broek, Maries

    2013-01-01

    We investigated whether antibodies against intracellular tumor-associated antigens support tumor-specific immunity when administered together with a treatment that destroys the tumor. We propose that released antigens form immune complexes with the antibodies, which are then efficiently taken up by dendritic cells. We cloned the first human monoclonal antibodies against the Cancer/Testis (CT) antigen, NY-ESO-1. We tested whether the monoclonal anti-NY-ESO-1 antibody (12D7) facilitates cross-presentation of a NY-ESO-1-derived epitope by dendritic cells to human CD8+ T cells, and whether this results in the maturation of dendritic cells in vitro. We investigated the efficacy of 12D7 in combination with chemotherapy using BALB/c mice bearing syngeneic CT26 tumors that express intracellular NY-ESO-1. Human dendritic cells that were incubated with NY-ESO-1:12D7 immune complexes efficiently stimulated NY-ESO-1(157-165)/HLA-A2-specific human CD8+ T cells to produce interferon-γ, whereas NY-ESO-1 alone did not. Furthermore, the incubation of dendritic cells with NY-ESO-1:12D7 immune complexes resulted in the maturation of dendritic cells. Treatment of BALB/c mice that bear CT26/NY-ESO-1 tumors with 5-fluorouracil (5-FU) plus 12D7 was significantly more effective than chemotherapy alone. We propose systemic injection of monoclonal antibodies (mAbs) against tumor-associated antigens plus a treatment that promotes the local release of those antigens resulting in immune complex formation as a novel therapeutic modality for cancer.

  9. Dialysis cultures with immobilized hybridoma cells for effective production of monoclonal antibodies

    OpenAIRE

    Pörtner, Ralf; Lüdemann, Ines; Märkl, Herbert

    1997-01-01

    An industrial scale reactor concept for continuous cultivation of immobilized animal cells (e.g. hybridoma cells) in a radial-flow fixed bed is presented, where low molecular weight metabolites are removed via dialysis membrane and high molecular products (e.g. monoclonal antibodies) are enriched. In a new “nutrient-split” feeding strategy concentrated medium is fed directly to the fixed bed unit, whereas a buffer solution is used as dialysis fluid. This feeding strategy was investigated in a...

  10. 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...

  11. 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...

  12. Direct detection of antibody concentration and affinity in human serum using microscale thermophoresis.

    Science.gov (United States)

    Lippok, Svenja; Seidel, Susanne A I; Duhr, Stefan; Uhland, Kerstin; Holthoff, Hans-Peter; Jenne, Dieter; Braun, Dieter

    2012-04-17

    The direct quantification of both the binding affinity and absolute concentration of disease-related biomarkers in biological fluids is particularly beneficial for differential diagnosis and therapy monitoring. Here, we extend microscale thermophoresis to target immunological questions. Optically generated thermal gradients were used to deplete fluorescently marked antigens in 2- and 10-fold-diluted human serum. We devised and validated an autocompetitive strategy to independently fit the concentration and dissociation constant of autoimmune antibodies against the cardiac β1-adrenergic receptor related to dilated cardiomyopathy. As an artificial antigen, the peptide COR1 was designed to mimic the second extracellular receptor loop. Thermophoresis resolved antibody concentrations from 2 to 200 nM and measured the dissociation constant as 75 nM. The approach quantifies antibody binding in its native serum environment within microliter volumes and without any surface attachments. The simplicity of the mix and probe protocol minimizes systematic errors, making thermophoresis a promising detection method for personalized medicine.

  13. GENERATION OF MONOCLONAL ANTIBODY AGAINST HUMAN ANDROGEN RECEPTOR WITH SYNTHETIC PEPTIDE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: Preparation of anti-human androgen receptor(hAR) monoclonal antibody (McAb). Methods: Four cells lines of hybridoma secreting specific monoclonal antibodies against AR were first established by fusion SP2/0 cell with spleen cell from BALB/c mice immunized with the coupling complex of hAR-KLH. Results: Paraffin-embedded sections of 45 prostate cancers were detected. There was an overall concordance of 91% using Immunohistochemistry between AR polyclonal antibody from Zymed and hAR-N McAb selfmade. Conclusion: The results show that the McAb obtained in this study would be a useful tool to detect the AR status in prostate cancer.

  14. MOUSE ANTIBODY RESPONSE FOLLOWING REPETITIVE INJECTIONS OF GAMMA-IRRADIATED HUMAN PLACENTA COLLAGENA

    Institute of Scientific and Technical Information of China (English)

    刘秉慈; MelvinSpira; 许增禄

    1994-01-01

    Injectable bovine collagen has been used clinically for years.But both the necessity of repeated injections to maintain corrections and the question of adverse allergic reactions developing from the use of a xenogenic collagen have been an area of serious concern.To overoome these adyerse effects,we have developed injectable collagen preparations from human placenta.Gamma irradiation was used for sterilization and crosslinking of the collagen.We observed the mouse immune respose to gamma-irradiated human placenta soluble and insoluble collagen follow-ing multiple injections.After six injections of these materials,no total IgG level increase was found,nor was anti-body specifically directed against human collagen found.Mouse antibody levels were also observed following Zyderm Ⅱ and Zyplast repetitive injections and follow-ing repetitive implantations of coated vicryl and chromic gut.No humoral immune response was found in this het-erologous type system.

  15. Development and characterization of a human antibody reference panel against erythropoietin suitable for the standardization of ESA immunogenicity testing.

    Science.gov (United States)

    Mytych, Daniel T; Barger, Troy E; King, Chadwick; Grauer, Stephanie; Haldankar, Raj; Hsu, Eric; Wu, Michelle Min; Shiwalkar, Mukta; Sanchez, Sergio; Kuck, Andrew; Civoli, Francesca; Sun, Jilin; Swanson, Steven J

    2012-08-31

    Recombinant human erythropoietin (EPO) has been used therapeutically for more than two decades in the treatment of anemia. Although EPO is generally well tolerated, in rare cases, patients have developed anti-EPO antibodies that can negatively impact safety and efficacy. Therefore, the detection of antibodies against EPO is a regulatory requirement during clinical development and post-approval. Although it is a rare phenomenon, antibody-mediated pure red cell aplasia (PRCA) is a serious complication than can result from antibodies that develop and neutralize EPO as well as endogenous erythropoietin. Currently, there are no universally accepted analytical methods to detect the full repertoire of binding and neutralizing anti-EPO antibodies. A number of different methods that differ in terms of antibodies detected and assay sensitivities are used by different manufacturers. There is also a lack of antibody reference reagents, and therefore no consistent basis for detecting and measuring anti-EPO antibodies. Reference reagents, with established ranges, are essential to monitor the safety and efficacy of all erythropoiesis-stimulating agents (ESAs) structurally related to human erythropoietin. This is the first report of the development and characterization of a panel of fully human antibodies against EPO suitable as reference reagents. The characteristics of antibodies within the panel were selected based on the prevalence of non-neutralizing IgG and IgM antibodies in non-PRCA patients and neutralizing IgG antibodies, including IgG1 and IgG4, in antibody-mediated PRCA subjects. The reference panel includes antibodies of high- and low-affinity with binding specificity to neutralizing and non-neutralizing erythropoietin epitopes. The subclass of human antibodies in this reference panel includes an IgG1, IgG2, and IgG4, as well as an IgM isotype. This antibody panel could help select appropriate immunogenicity assays, guide validation, and monitor assay performance

  16. Antibodies against high-risk human papillomavirus proteins as markers for invasive cervical cancer.

    Science.gov (United States)

    Combes, Jean-Damien; Pawlita, Michael; Waterboer, Tim; Hammouda, Doudja; Rajkumar, Thangarajan; Vanhems, Philippe; Snijders, Peter; Herrero, Rolando; Franceschi, Silvia; Clifford, Gary

    2014-11-15

    Different human papillomavirus (HPV) genes are expressed during the various phases of the HPV life cycle and may elicit immune responses in the process towards malignancy. To evaluate their association with cervical cancer, antibodies against proteins from HPV16 (L1, E1, E2, E4, E6 and E7) and HPV18/31/33/35/45/52/58 (L1, E6 and E7) were measured in serum of 307 invasive cervical cancer cases and 327 controls from Algeria and India. Antibody response was evaluated using a glutathione S-transferase-based multiplex serology assay and HPV DNA detected from exfoliated cervical cells using a GP5+/6+-mediated PCR assay. Among HPV16 DNA-positive cases, seroprevalence of HPV16 antibodies ranged from 16% for HPV16 E1 to 50% for HPV16 E6 and all were significantly higher than controls. Seroprevalence of E6, E7 and L1 antibodies for HPV18 and for at least one of HPV31/33/35/45/52/58 were also higher in cases positive for DNA of the corresponding type (50% and 30% for E6 of HPV18 and HPV31/33/35/45/52/58 combined, respectively). E6 and E7 antibodies were rarely found in controls, but cross-reactivity was evident among cancer cases positive for DNA of closely phylogenetically-related HPV types. E6 or E7 antibodies against any of the eight HPV types were detected in 66.1% of all cervical cancer cases, as compared to 10.1% of controls. E6, and to a lesser extent E7, antibodies appear to be specific markers of HPV-related malignancy. However, even among cases positive for the same type of HPV DNA, approximately one-third of cervical cancer cases show no detectable immune response to either E6 or E7.

  17. Production of High Affinity Human Single-chain Antibody Against PreS1 of Hepatitis B Virus:Comparison of Large Na(i)ve and In vitro Immune Phage Displayed Antibody Library%高亲和力抗乙型肝炎病毒PreS1的人源单链抗体的获得:天然及免疫抗体库的对比研究

    Institute of Scientific and Technical Information of China (English)

    张志超; 胡学军; 包永明; 杨青; 张红梅; 安利佳

    2002-01-01

    A large nave phage displayed human single-chain variable fragments antibody (scFv) library and an in vitro immune library were constructed in parallel conditions, based on the PBLs from healthy and sero-negative blood donors, part of which were in vitro immunized by peptide PreS1 conjugated to BSA. After 3 rounds of panning against PreS1, measurement of antibody-antigen reaction revealed: a scFv specific to PreS1 from the immune library was obtained, which affinity (k=10-7~10-8 M) was higher than that from the nave one (k=10-6~10-7 M). Sequencing of the two scFv showed they were human antibodies, which may be of interest in therapy of Hepatitis B. This investigation also illustrated that the method of in vitro immunization results in antibody library more satisfied even than the large nave one.%以健康人的外周血淋巴细胞为来源,以偶联BSA的乙型肝炎病毒PreS1肽体外免疫.分别从免疫和未经免疫的淋巴细胞提取RNA,扩增抗体基因,构建大容量天然单链抗体(scFv)噬菌体展示文库和体外免疫scFv抗体库.以PreS1肽进行3轮淘选后,抗原抗体反应结果显示,从免疫库中获得了亲和力10-7~10-8 M的抗乙型肝炎病毒PreS1的单链抗体,高于天然库的结果(10-6~10-7 M).测序结果表明两株抗体均为人抗体.为基因工程抗体用于临床治疗乙型肝炎奠定基础.同时证明淋巴细胞体外免疫方法构建的免疫抗体库优于大容量天然抗体库.

  18. Dissection of the Antibody Response against Herpes Simplex Virus Glycoproteins in Naturally Infected Humans

    Science.gov (United States)

    Huang, Zhen-Yu; Whitbeck, J. Charles; Ponce de Leon, Manuel; Lou, Huan; Wald, Anna; Krummenacher, Claude; Eisenberg, Roselyn J.; Cohen, Gary H.

    2014-01-01

    ABSTRACT Relatively little is known about the extent of the polyclonal antibody (PAb) repertoire elicited by herpes simplex virus (HSV) glycoproteins during natural infection and how these antibodies affect virus neutralization. Here, we examined IgGs from 10 HSV-seropositive individuals originally classified as high or low virus shedders. All PAbs neutralized virus to various extents. We determined which HSV entry glycoproteins these PAbs were directed against: glycoproteins gB, gD, and gC were recognized by all sera, but fewer sera reacted against gH/gL. We previously characterized multiple mouse monoclonal antibodies (MAbs) and mapped those with high neutralizing activity to the crystal structures of gD, gB, and gH/gL. We used a biosensor competition assay to determine whether there were corresponding human antibodies to those epitopes. All 10 samples had neutralizing IgGs to gD epitopes, but there were variations in which epitopes were seen in individual samples. Surprisingly, only three samples contained neutralizing IgGs to gB epitopes. To further dissect the nature of these IgGs, we developed a method to select out gD- and gB-specific IgGs from four representative sera via affinity chromatography, allowing us to determine the contribution of antibodies against each glycoprotein to the overall neutralization capacity of the serum. In two cases, gD and gB accounted for all of the neutralizing activity against HSV-2, with a modest amount of HSV-1 neutralization directed against gC. In the other two samples, the dominant response was to gD. IMPORTANCE Antibodies targeting functional epitopes on HSV entry glycoproteins mediate HSV neutralization. Virus-neutralizing epitopes have been defined and characterized using murine monoclonal antibodies. However, it is largely unknown whether these same epitopes are targeted by the humoral response to HSV infection in humans. We have shown that during natural infection, virus-neutralizing antibodies are principally

  19. Single cycle structure-based humanization of an anti-nerve growth factor therapeutic antibody.

    Directory of Open Access Journals (Sweden)

    Sonia Covaceuszach

    Full Text Available Most forms of chronic pain are inadequately treated by present therapeutic options. Compelling evidence has accumulated, demonstrating that Nerve Growth Factor (NGF is a key modulator of inflammatory and nociceptive responses, and is a promising target for the treatment of human pathologies linked to chronic and inflammatory pain. There is therefore a growing interest in the development of therapeutic molecules antagonising the NGF pathway and its nociceptor sensitization actions, among which function-blocking anti-NGF antibodies are particularly relevant candidates.In this respect, the rat anti-NGF αD11 monoclonal antibody (mAb is a potent antagonist, able to effectively antagonize rodent and human NGF in a variety of in vitro and in vivo systems. Here we show that mAb αD11 displays a significant analgesic effect in two different models of persistent pain in mice, with a remarkable long-lasting activity. In order to advance αD11 mAb towards its clinical application in man, anti-NGF αD11 mAb was humanized by applying a novel single cycle strategy based on the a priori experimental determination of the crystal and molecular structure of the parental Fragment antigen-binding (Fab. The humanized antibody (hum-αD11 was tested in vitro and in vivo, showing that the binding mode and the NGF neutralizing biological activities of the parental antibody are fully preserved, with even a significant affinity improvement. The results firmly establish hum-αD11 as a lead candidate for clinical applications in a therapeutic area with a severe unmet medical need. More generally, the single-cycle structure-based humanization method represents a considerable improvement over the standard humanization methods, which are intrinsically empirical and require several refinement cycles.

  20. Single Cycle Structure-Based Humanization of an Anti-Nerve Growth Factor Therapeutic Antibody

    Science.gov (United States)

    Covaceuszach, Sonia; Marinelli, Sara; Krastanova, Ivet; Ugolini, Gabriele; Pavone, Flaminia; Lamba, Doriano; Cattaneo, Antonino

    2012-01-01

    Most forms of chronic pain are inadequately treated by present therapeutic options. Compelling evidence has accumulated, demonstrating that Nerve Growth Factor (NGF) is a key modulator of inflammatory and nociceptive responses, and is a promising target for the treatment of human pathologies linked to chronic and inflammatory pain. There is therefore a growing interest in the development of therapeutic molecules antagonising the NGF pathway and its nociceptor sensitization actions, among which function-blocking anti-NGF antibodies are particularly relevant candidates. In this respect, the rat anti-NGF αD11 monoclonal antibody (mAb) is a potent antagonist, able to effectively antagonize rodent and human NGF in a variety of in vitro and in vivo systems. Here we show that mAb αD11 displays a significant analgesic effect in two different models of persistent pain in mice, with a remarkable long-lasting activity. In order to advance αD11 mAb towards its clinical application in man, anti-NGF αD11 mAb was humanized by applying a novel single cycle strategy based on the a priori experimental determination of the crystal and molecular structure of the parental Fragment antigen-binding (Fab). The humanized antibody (hum-αD11) was tested in vitro and in vivo, showing that the binding mode and the NGF neutralizing biological activities of the parental antibody are fully preserved, with even a significant affinity improvement. The results firmly establish hum-αD11 as a lead candidate for clinical applications in a therapeutic area with a severe unmet medical need. More generally, the single-cycle structure-based humanization method represents a considerable improvement over the standard humanization methods, which are intrinsically empirical and require several refinement cycles. PMID:22403636

  1. Production in yeast of pseudotype virus-like particles harboring functionally active antibody fragments neutralizing the cytolytic activity of vaginolysin

    Directory of Open Access Journals (Sweden)

    Pleckaityte Milda

    2011-12-01

    Full Text Available Abstract Background Recombinant antibodies can be produced in different formats and different expression systems. Single chain variable fragments (scFvs represent an attractive alternative to full-length antibodies and they can be easily produced in bacteria or yeast. However, the scFvs exhibit monovalent antigen-binding properties and short serum half-lives. The stability and avidity of the scFvs can be improved by their multimerization or fusion with IgG Fc domain. The aim of the current study was to investigate the possibilities to produce in yeast high-affinity scFv-Fc proteins neutralizing the cytolytic activity of vaginolysin (VLY, the main virulence factor of Gardnerella vaginalis. Results The scFv protein derived from hybridoma cell line producing high-affinity neutralizing antibodies against VLY was fused with human IgG1 Fc domain. Four different variants of anti-VLY scFv-Fc fusion proteins were constructed and produced in yeast Saccharomyces cerevisiae. The non-tagged scFv-Fc and hexahistidine-tagged scFv-Fc proteins were found predominantly as insoluble aggregates and therefore were not suitable for further purification and activity testing. The addition of yeast α-factor signal sequence did not support secretion of anti-VLY scFv-Fc but increased the amount of its intracellular soluble form. However, the purified protein showed a weak VLY-neutralizing capability. In contrast, the fusion of anti-VLY scFv-Fc molecules with hamster polyomavirus-derived VP2 protein and its co-expression with VP1 protein resulted in an effective production of pseudotype virus-like particles (VLPs that exhibited strong VLY-binding activity. Recombinant scFv-Fc molecules displayed on the surface of VLPs neutralized VLY-mediated lysis of human erythrocytes and HeLa cells with high potency comparable to that of full-length antibody. Conclusions Recombinant scFv-Fc proteins were expressed in yeast with low efficiency. New approach to display the sc

  2. Production in yeast of pseudotype virus-like particles harboring functionally active antibody fragments neutralizing the cytolytic activity of vaginolysin.

    Science.gov (United States)

    Pleckaityte, Milda; Zvirbliene, Aurelija; Sezaite, Indre; Gedvilaite, Alma

    2011-12-15

    Recombinant antibodies can be produced in different formats and different expression systems. Single chain variable fragments (scFvs) represent an attractive alternative to full-length antibodies and they can be easily produced in bacteria or yeast. However, the scFvs exhibit monovalent antigen-binding properties and short serum half-lives. The stability and avidity of the scFvs can be improved by their multimerization or fusion with IgG Fc domain. The aim of the current study was to investigate the possibilities to produce in yeast high-affinity scFv-Fc proteins neutralizing the cytolytic activity of vaginolysin (VLY), the main virulence factor of Gardnerella vaginalis. The scFv protein derived from hybridoma cell line producing high-affinity neutralizing antibodies against VLY was fused with human IgG1 Fc domain. Four different variants of anti-VLY scFv-Fc fusion proteins were constructed and produced in yeast Saccharomyces cerevisiae. The non-tagged scFv-Fc and hexahistidine-tagged scFv-Fc proteins were found predominantly as insoluble aggregates and therefore were not suitable for further purification and activity testing. The addition of yeast α-factor signal sequence did not support secretion of anti-VLY scFv-Fc but increased the amount of its intracellular soluble form. However, the purified protein showed a weak VLY-neutralizing capability. In contrast, the fusion of anti-VLY scFv-Fc molecules with hamster polyomavirus-derived VP2 protein and its co-expression with VP1 protein resulted in an effective production of pseudotype virus-like particles (VLPs) that exhibited strong VLY-binding activity. Recombinant scFv-Fc molecules displayed on the surface of VLPs neutralized VLY-mediated lysis of human erythrocytes and HeLa cells with high potency comparable to that of full-length antibody. Recombinant scFv-Fc proteins were expressed in yeast with low efficiency. New approach to display the scFv-Fc molecules on the surface of pseudotype VLPs was successful and

  3. Crystallization of the Fab from a human monoclonal antibody against gp 41 of human immunodeficiency virus type I

    Science.gov (United States)

    Casale, Elena; He, Xiao-Min; Snyder, Robert S.; Carter, Daniel C.; Wenisch, Elisabeth; Jungbauer, Alois; Tauer, Christa; Ruker, Florian; Righetti, Pier Giorgio

    1990-01-01

    A monoclonal IgG antibody directed against gp 41 from the human immunodeficiency virus (HIV-1) has been crystallized in both intact and Fab forms. Crystals of the intact antibody grow as tetragonal-like prisms too small for conventional X-ray analysis. However, the Fab portion of the antibody produces suitable platelike crystals which belong to the space group P2(1)2(1)2(1) with unit cell constants of a = 66.5 A, b = 74.3 A, and c = 105.3 A. There is one molecule of Fab in the asymmetric unit. The Fab crystals show diffraction to d-spacings less than 3.0 A.

  4. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Holers, V.M.; Kotzin, B.L.

    1985-09-01

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases.

  5. Antiidiotypic antibody related to the 84 kD human sperm membrane protein

    Institute of Scientific and Technical Information of China (English)

    YUJUN; WANGLINFANG; 等

    1990-01-01

    Wistar rats were inoculated with purified YWK-I antibody.The anti-idiotypic antibodies were isolated from rat sera by successive passage over affinity chromatography columns of YWK-I mAb and normal mouse Igs.Specificity of anti-Id antibody was established by ELISA.The 84kD protein inhibited the binding of anti-Id to YWK-I mAb,but failed to repress antibody against normal mouse Ig binding to YWK-I mAb.In competitive inhibition assay,84kD protein had shown the ability to compete with anti-Id binding to YWK-I mAb in a dose-dependent manner.Crude sperm extract showed a lower competitive ability.No effect was found with the irrelevant 36kD sperm protein.The antisera from the Balb/C micr immunized with AId contained Ab3 that reacted with 84kD sperm protein.The binding of anti-Id to YWK-I mAb was inhibited by Ab3 in a dose-dependent fashion and Ab3 was shown to be able to induce human sperm agglutination.These results indicate that anti-Id which may mimic an epitope of the 84kD protein could be exploited as an antigen to raise antibodies against sperm protein.

  6. Structural basis for Marburg virus neutralization by a cross-reactive human antibody.

    Science.gov (United States)

    Hashiguchi, Takao; Fusco, Marnie L; Bornholdt, Zachary A; Lee, Jeffrey E; Flyak, Andrew I; Matsuoka, Rei; Kohda, Daisuke; Yanagi, Yusuke; Hammel, Michal; Crowe, James E; Saphire, Erica Ollmann

    2015-02-26

    The filoviruses, including Marburg and Ebola, express a single glycoprotein on their surface, termed GP, which is responsible for attachment and entry of target cells. Filovirus GPs differ by up to 70% in protein sequence, and no antibodies are yet described that cross-react among them. Here, we present the 3.6 Å crystal structure of Marburg virus GP in complex with a cross-reactive antibody from a human survivor, and a lower resolution structure of the antibody bound to Ebola virus GP. The antibody, MR78, recognizes a GP1 epitope conserved across the filovirus family, which likely represents the binding site of their NPC1 receptor. Indeed, MR78 blocks binding of the essential NPC1 domain C. These structures and additional small-angle X-ray scattering of mucin-containing MARV and EBOV GPs suggest why such antibodies were not previously elicited in studies of Ebola virus, and provide critical templates for development of immunotherapeutics and inhibitors of entry.

  7. Structural and functional characterization of a human IgG monoclonal antiphospholipid antibody.

    Science.gov (United States)

    Prinz, Nadine; Häuser, Friederike; Lorenz, Mareike; Lackner, Karl J; von Landenberg, Philipp

    2011-01-01

    Antiphospholipid antibodies (aPL) are likely involved in the pathogenesis of the antiphospholipid syndrome (APS). This study analyzes the structural and functional characteristics of a human monoclonal aPL (HL7G) from the IgG2 subtype with λ light chains generated from a patient with primary APS and recurrent cerebral microemboli. DNA encoding the variable region of heavy and light chains of the antibody was sequenced, analyzed, and compared to HL5B a previously described monoclonal aPL from the same patient. Both antibodies are derived from the same germline genes. HL7G had similar but more extensive somatic mutations in the CDR1 and 2 regions than HL5B, indicating that both antibodies are closely related and derived by a T cell-dependent antigen driven process. In ELISA assays HL7G bound to cardiolipin and several other phospholipid antigens in the absence of protein cofactors. Different from HL5B this aPL bound to β2-glycoprotein I (β2GPII). This suggests that reactivity of aPL against β2GPI is determined by only few specific amino acid exchanges. HL7G was able to induce tissue factor (TF) as one of the procoagulant effects of aPL. Our data suggest that the binding specificity of aPL is only of limited value to predict the biological effect and the pathophysiological impact of the antibodies. Copyright © 2010 Elsevier GmbH. All rights reserved.

  8. Expression and purification of human ARP1 protein and rapid preparation of polyclonal antibody.

    Science.gov (United States)

    Sun, Mingjuan; Zou, Rongjiang; Dong, Xiaoyi; Zong, Ying; Gao, Yun; Wang, Lianghua; Jiao, Binghua

    2013-01-01

    Angiopoietin-related protein 1 (ARP1) is one of the antiangiogenic factors and plays an important role in endothelial cell proliferation, migration, and blood vessel network formation. Here a rapid method to prepare ARP1 polyclonal antibody in 1 month was developed. The gene of fibrinogen homology domain (FD) for ARP1 was cloned and the protein was expressed in a soluble form of MBP-FD fused protein. The MBP-FD protein was purified using amylose affinity chromatography of maltose-binding protein. Polyclonal antibodies against MBP-FD were obtained through immunization in BALB/c mice. The titer was determined by indirect enzyme-linked immunosorbent assay (ELISA), and the antibody specificity was assessed by Western blot. The full-length ARP1 protein in stable form expressed in transfected human large lung cancer cell lines NCI-H460 was detected by immunocytochemistry (ICC) analysis using ARP1 polyclonal antibodies. The result shows that the antibody possesses good specificity and sensitivity. This work provides a substantial base for the further studies of ARP1 function and associated mechanisms. Supplemental materials are available for this article. Go to the publisher's online edition of Preparative Biochemistry and Biotechnology to view the supplemental file.

  9. [Salmonella typhi vaccination response study reveals defective antibody production selective IgA deficiency patient].

    Science.gov (United States)

    Pleguezuelo, Daniel E; Gianelli, Carla

    2015-01-01

    Selective IgA deficiency (SIgAD) is the most prevalent immunodeficiency worldwide, progressing to common variable immunodeficiency only in few reported cases. We report the case of a Spanish female aged 22 and diagnosed of selective IgA deficiency, a long history of bronchitis, several episodes of pneumonia, bilateral bronchiectasis, normal IgG, IgM, IgG subclasses, and detectable pre-vaccination IgG antibodies against tetanus toxoid and Streptococcus pneumoniae. She was evaluated in our clinic in order to rule out common variable immunodeficiency. We observed good antibody response to tetanus toxoid, absence of circulating switched memory B cells, decreased response to pneumococcal polysaccharide antigens and a lack of response to Salmonella typhi vaccine. Most SIgAD patients presents with upper respiratory tract infections or mild diarrhea. Those with lower tract infections, pneumonia or untreatable diarrhea should follow B-cell subpopulations' study and antibody response to vaccines. Absence of response to Salmonella typhi vaccine allowed us to expose the defective antibody production.

  10. [Production and characteristics of monoclonal antibodies against individual prekeratins in simple types of rat epithelium].

    Science.gov (United States)

    Troianovskiĭ, S M; Krutovskikh, V A; Bannikov, G A

    1986-06-01

    BALB/c mice were immunized with intermediate filaments (IF) from the rat colon mucosa, and their splenocytes were fused with myeloma cells to obtain hybridomas. Specific antibody production was assessed by indirect immunofluorescence on cultured rat hepatoma 27 containing prekeratins. The clones that stained IF in hepatoma and not in fibroblasts were judged positive. Clones E3 and E6 were shown to produce monoclonal antibodies against prekeratin with molecular mass of 40 kD (PK40), while clones E2 and E7 produced antibodies against prekeratin with molecular mass of 55 kD (PK55). This was established by immunoblotting with 125I-protein A in cell lysates from the colon, bladder, and hepatoma 27. Only PK55 was revealed in liver and salivary gland lysates. The above proteins were not detected in esophagus, fibroblast and skeletal muscle cell lysates. The monoclonal antibodies make it possible to study individual prekeratin expression in embryogenesis, differentiation and neoplastic transformation of simple epithelium.

  11. Production and characterization of monoclonal antibodies against Campylobacter fetus subsp. venerealis

    Directory of Open Access Journals (Sweden)

    Telma M. Alves

    2012-07-01

    Full Text Available Myeloma cells Sp2/0-Ag14 and spleen cells from BALB/c mouse immunized with sonicated Campylobacter fetus subsp. venerealis NCTC 10354 were fused with polyethylene glycol (PEG for the selection of clones producing antibodies. Clones were obtained by limiting dilution and screened for the production of specific antibodies to C. fetus subsp. venerealis NCTC 10354 by indirect ELISA and western blot against a panel of bacteria: C. fetus subsp. venerealis NCTC 10354, C. fetus subsp fetus ADRI 1812, C. sputorum biovar sputorum LMG 6647, C. lari NCTC 11352, and Arcobacter skirrowii LMG 6621 for the ELISA and C. fetus subsp. venerealis NCTC 10354 and C. sputorum biovar sputorum LMG 6647 for the western blotting. Fifteen clones producing monoclonal antibodies (MAbs anti-C. fetus subsp. venerealis of the IgM (1 and IgG (14 classes were further screened for species-specificity. Four clones of the 15 obtained were producers of species-specific monoclonal antibodies (MAbs: two were specific for C. fetus subsp. venerealis and two were specific for C. fetus subsp. fetus. None of the clones were reactive against C. sputorum biovar sputorum LMG 6647. All clones recognized a protein with molecular mass of approximately 148 kDa from lysed C. fetus subsp. venerealis NCTC 10354.

  12. Antibody Engineering for Pursuing a Healthier Future

    Science.gov (United States)

    Saeed, Abdullah F. U. H.; Wang, Rongzhi; Ling, Sumei; Wang, Shihua

    2017-01-01

    Since the development of antibody-production techniques, a number of immunoglobulins have been developed on a large scale using conventional methods. Hybridoma technology opened a new horizon in the production of antibodies against target antigens of infectious pathogens, malignant diseases including autoimmune disorders, and numerous potent toxins. However, these clinical humanized or chimeric murine antibodies have several limitations and complexities. Therefore, to overcome these difficulties, recent advances in genetic engineering techniques and phage display technique have allowed the production of highly specific recombinant antibodies. These engineered antibodies have been constructed in the hunt for novel therapeutic drugs equipped with enhanced immunoprotective abilities, such as engaging immune effector functions, effective development of fusion proteins, efficient tumor and tissue penetration, and high-affinity antibodies directed against conserved targets. Advanced antibody engineering techniques have extensive applications in the fields of immunology, biotechnology, diagnostics, and therapeutic medicines. However, there is limited knowledge regarding dynamic antibody development approaches. Therefore, this review extends beyond our understanding of conventional polyclonal and monoclonal antibodies. Furthermore, recent advances in antibody engineering techniques together with antibody fragments, display technologies, immunomodulation, and broad applications of antibodies are discussed to enhance innovative antibody production in pursuit of a healthier future for humans.

  13. Antithyroglobulin antibody

    Science.gov (United States)

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

  14. Design and operation of a continuous integrated monoclonal antibody production process.

    Science.gov (United States)

    Steinebach, Fabian; Ulmer, Nicole; Wolf, Moritz; Decker, Lara; Schneider, Veronika; Wälchli, Ruben; Karst, Daniel; Souquet, Jonathan; Morbidelli, Massimo

    2017-07-10

    The realization of an end-to-end integrated continuous lab-scale process for monoclonal antibody manufacturing is described. For this, a continuous cultivation with filter-based cell-retention, a continuous two column capture process, a virus inactivation step, a semi-continuous polishing step (twin-column MCSGP), and a batch-wise flow-through polishing step were integrated and operated together. In each unit, the implementation of internal recycle loops allows to improve the performance: (a) in the bioreactor, to simultaneously increase the cell density and volumetric productivity, (b) in the capture process, to achieve improved capacity utilization at high productivity and yield, and (c) in the MCSGP process, to overcome the purity-yield trade-off of classical batch-wise bind-elute polishing steps. Furthermore, the design principles, which allow the direct connection of these steps, some at steady state and some at cyclic steady state, as well as straight-through processing, are discussed. The setup was operated for the continuous production of a commercial monoclonal antibody, resulting in stable operation and uniform product quality over the 17 cycles of the end-to-end integration. The steady-state operation was fully characterized by analyzing at the outlet of each unit at steady state the product titer as well as the process (HCP, DNA, leached Protein A) and product (aggregates, fragments) related impurities. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 2017. © 2017 American Institute of Chemical Engineers.

  15. Production and purification of avian antibodies (IgYs from inclusion bodies of a recombinant protein central in NAD+ metabolism

    Directory of Open Access Journals (Sweden)

    Paula A. Moreno-González

    2013-08-01

    Full Text Available The use of hens for the production of polyclonal antibodies reduces animal intervention and moreover yields a higher quantity of antibodies than other animal models.  The phylogenetic distance between bird and mammal antigens, often leads to more specific avian antibodies than their mammalian counterparts.Since a large amount of antigen is required for avian antibody production, the use of recombinant proteins for this procedure has been growing faster over the last years. Nevertheless, recombinant protein production through heterologous systems frequently prompts the protein to precipitate, forming insoluble aggregates of limited utility (inclusion bodies. A methodology for the production of avian polyclonal antibodies, using recombinant protein from inclusion bodies is presented in this article.In order to produce the antigen, a recombinant Nicotinamide mononucleotide adenylyltransferase from Giardia intestinalis (His-GiNMNAT was expressed in Escherichia coli.  The protein was purified through solubilization from inclusion bodies prior to its renaturalization.  Antibodies were purified from egg yolk of immunized hens by water dilution, followed by ammonium sulfate precipitation and thiophilic affinity chromatography.The purified antibodies were tested against His-GiNMNAT protein in Western blot essays. From one egg yolk, 14.4 mg of highly pure IgY were obtained; this antibody was able to detect 15ng of His-GiNMNAT.  IgY specificity was improved by means of antigen affinity purification, allowing its use for parasite protein recognition.

  16. [Immunohistochemical study of human breast tumors using monoclonal antibodies to intermediate filament proteins (nonproliferating epithelial structures in breast dysplasia)].

    Science.gov (United States)

    Gel'shteĭn, V I; Chipysheva, T A; Litvinova, L V; Ermilova, V D; Bannikov, G A

    1985-01-01

    An immunohistochemical analysis of nonproliferating epithelial structures was carried out in 10 samples of human breast dysplasia and in 4 samples of tissue surrounding mammary gland carcinoma. Monoclonal mouse antibodies against individual prekeratins of rat monolayer epithelial antibodies of clone C12 against rat prekeratin with the molecular mass 49 kilodalton and antibodies of clone E3 against rat prekeratin with the molecular mass 40 kilodalton-monoclonal antibodies against vimentin (clone 30), as well as polyclonal antibodies against smooth muscle myosin and against the basement membrane glycoprotein laminin were used. The lining epithelium of all glandular structures reacted only with C12 antibodies. Two variants of myoepithelial cells containing myosin were detected. Variant I contains myosin and vimentin and is localized in intralobular ducts. Variant 2 contains myosin and prekeratin, recognized by E3 antibodies and is found in extralobular ducts.

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

    Science.gov (United States)

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

    2004-09-01

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

  18. Blockade of invariant TCR-CD1d interaction specifically inhibits antibody production against blood group A carbohydrates

    Science.gov (United States)

    Tazawa, Hirofumi; Irei, Toshimitsu; Tanaka, Yuka; Igarashi, Yuka; Tashiro, Hirotaka

    2013-01-01

    Previously, we detected B cells expressing receptors for blood group A carbohydrates in the CD11b+CD5+ B-1a subpopulation in mice, similar to that in blood group O or B in humans. In the present study, we demonstrate that CD1d-restricted natural killer T (NKT) cells are required to produce anti-A antibodies (Abs), probably through collaboration with B-1a cells. After immunization of wild-type (WT) mice with human blood group A red blood cells (A-RBCs), interleukin (IL)-5 exclusively and transiently increased and the anti-A Abs were elevated in sera. However, these reactions were not observed in CD1d−/− mice, which lack NKT cells. Administration of anti-mouse CD1d blocking monoclonal Abs (mAb) prior to immunization abolished IL-5 production by NKT cells and anti-A Ab production in WT mice. Administration of anti-IL-5 neutralizing mAb also diminished anti-A Ab production in WT mice, suggesting that IL-5 secreted from NKT cells critically regulates anti-A Ab production by B-1a cells. In nonobese diabetic/severe combined immunodeficient (NOD/SCID/γcnull) mice, into which peripheral blood mononuclear cells from type O human volunteers were engrafted, administration of anti-human CD1d mAb prior to A-RBC immunization completely inhibited anti-A Ab production. Thus, anti-CD1d treatment might constitute a novel approach that could help in evading Ab-mediated rejection in ABO-incompatible transplant recipients. PMID:23943651

  19. The Role of TLR4 on B Cell Activation and Anti-β2GPI Antibody Production in the Antiphospholipid Syndrome

    Science.gov (United States)

    2016-01-01

    High titer of anti-β2-glycoprotein I antibodies (anti-β2GPI Ab) plays a pathogenic role in antiphospholipid syndrome (APS). Numerous studies have focused on the pathological mechanism in APS; however, little attention is paid to the immune mechanism of production of anti-β2GPI antibodies in APS. Our previous study demonstrated that Toll-like receptor 4 (TLR4) plays a vital role in the maturation of bone marrow-derived dendritic cells (BMDCs) from the mice immunized with human β2-glycoprotein I (β2GPI). TLR4 is required for the activation of B cells and the production of autoantibody in mice treated with β2GPI. However, TLR4 provides a third signal for B cell activation and then promotes B cells better receiving signals from both B cell antigen receptor (BCR) and CD40, thus promoting B cell activation, surface molecules expression, anti-β2GPI Ab production, and cytokines secretion and making B cell functioning like an antigen presenting cell (APC). At the same time, TLR4 also promotes B cells producing antibodies by upregulating the expression of B-cell activating factor (BAFF). In this paper, we aim to review the functions of TLR4 in B cell immune response and antibody production in autoimmune disease APS and try to find a new way for the prevention and treatment of APS. PMID:27868072

  20. Human Ig knockin mice to study the development and regulation of HIV-1 broadly neutralizing antibodies.

    Science.gov (United States)

    Verkoczy, Laurent; Alt, Frederick W; Tian, Ming

    2017-01-01

    A major challenge for HIV-1 vaccine research is developing a successful immunization approach for inducing broadly neutralizing antibodies (bnAbs). A key shortcoming in meeting this challenge has been the lack of animal models capable of identifying impediments limiting bnAb induction and ranking vaccine strategies for their ability to promote bnAb development. Since 2010, immunoglobulin knockin (KI) technology, involving inserting functional rearranged human variable exons into the mouse IgH and IgL loci has been used to express bnAbs in mice. This approach has allowed immune tolerance mechanisms limiting bnAb production to be elucidated and strategies to overcome such limitations to be evaluated. From these studies, along with the wealth of knowledge afforded by analyses of recombinant Ig-based bnAb structures, it became apparent that key functional features of bnAbs often are problematic for their elicitation in mice by classic vaccine paradigms, necessitating more iterative testing of new vaccine concepts. In this regard, bnAb KI models expressing deduced precursor V(D)J rearrangements of mature bnAbs or unrearranged germline V, D, J segments (that can be assembled into variable region exons that encode bnAb precursors), have been engineered to evaluate novel immunogens/regimens for effectiveness in driving bnAb responses. One promising approach emerging from such studies is the ability of sequentially administered, modified immunogens (designed to bind progressively more mature bnAb precursors) to initiate affinity maturation. Here, we review insights gained from bnAb KI studies regarding the regulation and induction of bnAbs, and discuss new Ig KI methodologies to manipulate the production and/or expression of bnAbs in vivo, to further facilitate vaccine-guided bnAb induction studies.

  1. Construction of human Fab library and screening of a single-domain antibody of amyloid-beta 42 oligomers

    Institute of Scientific and Technical Information of China (English)

    Zuanning Yuan; Minge Du; Yiwen Chen; Fei Dou

    2013-01-01

    Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli-gomers and constructed a naïve human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe-cifical y recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked immunosorbent assay demonstrated this antibody bound specifical y to human amyloid-beta 42 te-tramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc-cessful y constructed a human phage display library and screened a single-domain antibody that specifical y recognized amyloid-beta 42 oligomers.

  2. Cytotoxic murine monoclonal antibody LAM8 with specificity for human small cell carcinoma of the lung.

    Science.gov (United States)

    Stahel, R A; O'Hara, C J; Mabry, M; Waibel, R; Sabbath, K; Speak, J A; Bernal, S D

    1986-04-01

    The reactivity of the murine immunoglobulin monoclonal antibody LAM8 directed against a membrane antigen of human small cell carcinoma (SCC) of the lung was investigated on human cell lines and tissues. Indirect immunofluorescence staining, radioimmunoassays, and cytotoxicity assays showed LAM8 antibody to selectively react with SCC but not with non-SCC lung cancer cell lines and extrapulmonary tumor cell lines. Unlike other SCC antibodies, including those we have previously described, highly preferential reactivity with SCC tissues was also demonstrated by immunoperoxidase staining of deparaffinized formalin-fixed tissue sections. Membrane and cytoplasmic staining was seen in of 9 of 12 SCC tissues. No significant staining was seen in non-SCC lung cancer and a wide range of other tumors, including mesothelioma and bronchial carcinoids. Significant LAM8 reactivity was also absent in normal tissues of all major organs. Few tumors and epithelial tissues, including bronchial epithelium had rare LAM8 positive cells which were always less than 2% of the entire cell population. In vitro treatment with antibody and human complement was highly cytotoxic to SCC cells, but had not effect on bone marrow progenitor cells. Immunoblotting of membrane extracts separated on sodium dodecyl sulfate-polyacrylamide gels showed the LAM8 antigen to have a band of an approximate molecular weight of 135,000 and a cluster of bands with approximate molecular weights of 90,000. This reactivity was lost after incubation of the extracts with periodate. LAM8 antibody shows a highly preferential reactivity with SCC cell lines and formalin-fixed paraffin-embedded SCC tissues and is selectively cytotoxic to cells expressing LAM8 antigen.

  3. [Research of Human-mouse Chimeric Antibodies Against Ebola Virus Nucleoprotein].

    Science.gov (United States)

    Zhou, Rongping; Sun, Lina; Liu, Yang; Wu, Wei; Li, Chuan; Liang, Mifang; Qiu, Peihong

    2016-01-01

    The Ebola virus is highly infectious and can result in death in ≤ 90% of infected subjects. Detection of the Ebola virus and diagnosis of infection are extremely important for epidemic control. Presently, Chinese laboratories detect the nucleic acids of the Ebola virus by real-time reverse transcription-polymerase chain reaction (RT-PCR). However, such detection takes a relatively long time and necessitates skilled personnel and expensive equipment. Enzyme-linked immunosorbent assay (ELISA) of serum is simple, easy to operate, and can be used to ascertain if a patient is infected with the Ebola virus as well as the degree of infection. Hence, ELISA can be used in epidemiological investigations and is a strong complement to detection of nucleic acids. Cases of Ebola hemorrhagic fever have not been documented in China, so quality-control material for positive serology is needed. Construction and expression of human-mouse chimeric antibodies against the nucleoprotein of the Ebola virus was carried out. Genes encoding variable heavy (VH) and variable light (VL) chains were extracted and amplified from murine hybridoma cells. Genes encoding the VH and VL chains of monoclonal antibodies were amplified by RT-PCR. According to sequence analyses, a primer was designed to amplify functional sequences relative to VH and VL chain. The eukaryotic expression vector HL51-14 carrying some human antibody heavy chain- and light chain-constant regions was used. IgG antibodies were obtained by transient transfection of 293T cells. Subsequently, immunological detection and immunological identification were identified by ELISA, immunofluorescence assay, and western blotting. These results showed that we constructed and purified two human- mouse chimeric antibodies.

  4. Serrumab: a novel human single chain-fragment antibody with multiple scorpion toxin-neutralizing capacities.

    Science.gov (United States)

    Pucca, Manuela Berto; Cerni, Felipe Augusto; Peigneur, Steve; Arantes, Eliane Candiani; Tytgat, Jan; Barbosa, José Elpidio

    2014-01-01

    In Brazil, scorpion envenomation is an important public health problem. The yellow scorpion, Tityus serrulatus (Ts), is considered the most dangerous species in the country, being responsible for the most severe clinical cases of envenomation. Currently, the administration of serum produced in horses is recognized and used as a treatment for accidents with scorpions. However, horse herds' maintenance is costly and the antibodies are heterologous, which can cause anaphylaxis and Serum Sickness. In the present work, a human monoclonal fragment antibody, Serrumab, has been analysed. Toxin neutralizing effects of Serrumab were evaluated using a two-electrode voltage-clamp technique. The results show that Serrumab presented a high neutralizing effect against Ts β-toxins (Ts1, 43.2% and Ts2, 68.8%) and none or low neutralizing effect against α-toxins (Ts3, 0% and Ts5, 10%). Additional experiments demonstrated that Serrumab was also able to neutralize the action of toxins from other scorpion genus (Css II, 45.96% and Lqh III, 100%/β- and α-toxins, respectively). This work indicated that Serrumab is able to neutralize many toxins in Ts venom, and could being considered as a neutralizing antibody for formulating a human anti-scorpion serum in Brazil. Additionally, this work demonstrated that Serrumab could neutralize different toxins from distinct scorpion genus. All these results reinforce the idea that Serrumab is a scFv antibody with multiple neutralizing capacities and a promising candidate for inclusion in scorpion anti-venoms against different genera.

  5. Preexisting human antibodies neutralize recently emerged H7N9 influenza strains

    Science.gov (United States)

    Henry Dunand, Carole J.; Leon, Paul E.; Kaur, Kaval; Tan, Gene S.; Zheng, Nai-Ying; Andrews, Sarah; Huang, Min; Qu, Xinyan; Huang, Yunping; Salgado-Ferrer, Marlene; Ho, Irvin Y.; Taylor, William; Hai, Rong; Wrammert, Jens; Ahmed, Rafi; García-Sastre, Adolfo; Palese, Peter; Krammer, Florian; Wilson, Patrick C.

    2015-01-01

    The emergence and seasonal persistence of pathogenic H7N9 influenza viruses in China have raised concerns about the pandemic potential of this strain, which, if realized, would have a substantial effect on global health and economies. H7N9 viruses are able to bind to human sialic acid receptors and are also able to develop resistance to neuraminidase inhibitors without a loss in fitness. It is not clear whether prior exposure to circulating human influenza viruses or influenza vaccination confers immunity to H7N9 strains. Here, we demonstrate that 3 of 83 H3 HA-reactive monoclonal antibodies generated by individuals that had previously undergone influenza A virus vaccination were able to neutralize H7N9 viruses and protect mice against homologous challenge. The H7N9-neutralizing antibodies bound to the HA stalk domain but exhibited a difference in their breadth of reactivity to different H7 influenza subtypes. Mapping viral escape mutations suggested that these antibodies bind at least two different epitopes on the stalk region. Together, these results indicate that these broadly neutralizing antibodies may contribute to the development of therapies against H7N9 strains and may also be effective against pathogenic H7 strains that emerge in the future. PMID:25689254

  6. Human bocavirus infections are common in Beijing population indicated by sero-antibody prevalence analysis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lin-qing; QIAN Yuan; ZHU Ru-nan; DENG Jie; WANG Fang; DONG Hui-jin; SUN Yu; LI Yan

    2009-01-01

    Background Human bocavirus (HBoV) is a newly identified human parvovirus that was originally detected in the respiratory secretions of children with respiratory infections. This study aimed to learn about the importance of HBoV infections by revealing the prevalence of serum antibodies against HBoV in Beijing population.Methods Two batches of serum specimens collected in different periods were tested by Western blotting for specific IgG against HBoV using recombinant VP2 as antigen.Results Out of 677 serum specimens collected during April 1996 to March 1997, 400 (59.1%) were positive and antibody positive rate for another batch of 141 serum specimens collected in August, 2005 from adults aged from 20 years to over 60 years was 78.7% (111/141). Comparison of the sero-prevalence profiles for serum specimens collected during 1996-1997 to those collected in 2005 indicated that the antibody positive rate for specimens collected in 2005 was higher than that of the corresponding age groups collected during 1996-1997.Conclusions The data suggest that HBoV has been circulating in Beijing population for at least over 10 years, and most of children had been exposed to HBoV by age of 7 years. Higher HBoV antibody positive rate shown in the serum specimens collected in 2005 suggested that infections by HBoV have been increased in Beijing population in recent years.

  7. CD16 is indispensable for antibody-dependent cellular cytotoxicity by human monocytes

    Science.gov (United States)

    Yeap, Wei Hseun; Wong, Kok Loon; Shimasaki, Noriko; Teo, Esmeralda Chi Yuan; Quek, Jeffrey Kim Siang; Yong, Hao Xiang; Diong, Colin Phipps; Bertoletti, Antonio; Linn, Yeh Ching; Wong, Siew Cheng

    2016-01-01

    Antibody-dependent cellular cytotoxicity (ADCC) is exerted by immune cells expressing surface Fcγ receptors (FcγRs) against cells coated with antibody, such as virus-infected or transformed cells. CD16, the FcγRIIIA, is essential for ADCC by NK cells, and is also expressed by a subset of human blood monocytes. We found that human CD16− expressing monocytes have a broad spectrum of ADCC capacities and can kill cancer cell lines, primary leukemic cells and hepatitis B virus-infected cells in the presence of specific antibodies. Engagement of CD16 on monocytes by antibody bound to target cells activated β2-integrins and induced TNFα secretion. In turn, this induced TNFR expression on the target cells, making them susceptible to TNFα-mediated cell death. Treatment with TLR agonists, DAMPs or cytokines, such as IFNγ, further enhanced ADCC. Monocytes lacking CD16 did not exert ADCC but acquired this property after CD16 expression was induced by either cytokine stimulation or transient transfection. Notably, CD16+ monocytes from patients with leukemia also exerted potent ADCC. Hence, CD16+ monocytes are important effectors of ADCC, suggesting further developments of this property in the context of cellular therapies for cancer and infectious diseases. PMID:27670158

  8. In Vitro Characterization of Human Cytomegalovirus-Targeting Therapeutic Monoclonal Antibodies LJP538 and LJP539

    Science.gov (United States)

    Patel, Hetalkumar D.; Nikitin, Pavel; Gesner, Thomas; Lin, James J.; Barkan, David T.; Ciferri, Claudio; Carfi, Andrea; Akbarnejad Yazdi, Tahmineh; Skewes-Cox, Peter; Wiedmann, Brigitte; Jarousse, Nadine; Zhong, Weidong; Feire, Adam

    2016-01-01

    Human cytomegalovirus (HCMV) infection is usually benign in healthy individuals but can cause life-threatening disease in those with compromised immune systems. Approved drugs available to treat HCMV disease, including ganciclovir, cidofovir, and foscarnet, have significant toxicities that limit their use in certain patient populations. LJP538 and LJP539 are human monoclonal antibodies that are being evaluated as immunoglobulin therapeutics. The antibodies target glycoproteins gB and the gH/gL/UL128/UL130/UL131a pentameric complex, respectively. Here we present an in vitro characterization of these antibodies. We show that LJP538 and LJP539 are more potent than a marketed immunoglobulin at inhibiting HCMV infection of various cell lines relevant to pathogenesis. We find that LJP538 and LJP539 are active against a panel of clinical isolates in vitro and demonstrate minor-to-moderate synergy in combination. Passage of HCMV in the presence of LJP538 or LJP539 alone resulted in resistance-associated mutations that mapped to the target genes. However, no loss of susceptibility to the combination of antibodies was observed for >400 days in culture. Finally, the binding regions of LJP538 and LJP539 are conserved among clinical isolates. Taken together, these data support the use of LJP538 and LJP539 in combination for clinical trials in HCMV patients. PMID:27270290

  9. Purification of human seminal plasma no. 7 antigen by immunoaffinity chromatography on bound monoclonal antibody.

    Science.gov (United States)

    Isojima, S; Koyama, K; Fujiwara, N

    1982-01-01

    Human seminal plasma (HSP) No. 7 antigen was purified by immunoaffinity chromatography on bound 1C4 monoclonal antibody (Moab) (Shigeta et al., 1980b). The pooled HSP protein was applied to a CNBr-activated Sepharose 4B column of bound 1C4 Moab gamma globulin and the antibody bound fraction (fr) eluted was further purified by rechromatography in the same way. The purified antigen in the antibody bound fr obtained by rechromatography gave a single band on SDS-PAGE in a position corresponding to a molecular weight of 15,000 daltons. This preparation was 196.2 times more effective than the original HSP protein in neutralizing the sperm immobilizing activity of 1C4 Moab. The purified HSP No. 7 antigen contained iron, but was different from lactoferrin and transferrin. It did not show any enzymatic activities, such as those of acid phosphatase, LDH or trypsin inhibitor, and shared antigenicity with human milk protein. It was present in seminal plasma as a molecule with a higher molecular weight but seemed to be cleaved to a monomer of 15,000 daltons during purification procedures. This antigen is present on spermatozoa as sperm-coating antigen and the corresponding antibody can immobilize spermatozoa with complement. Images Fig. 3 PMID:7127911

  10. Germline V-genes sculpt the binding site of a family of antibodies neutralizing human cytomegalovirus

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, Christy A.; Bryson, Steve; McLean, Gary R.; Creagh, A. Louise; Pai, Emil F.; Schrader, John W. (Toronto); (UBC)

    2008-10-17

    Immunoglobulin genes are generated somatically through specialized mechanisms resulting in a vast repertoire of antigen-binding sites. Despite the stochastic nature of these processes, the V-genes that encode most of the antigen-combining site are under positive evolutionary selection, raising the possibility that V-genes have been selected to encode key structural features of binding sites of protective antibodies against certain pathogens. Human, neutralizing antibodies to human cytomegalovirus that bind the AD-2S1 epitope on its gB envelope protein repeatedly use a pair of well-conserved, germline V-genes IGHV3-30 and IGKV3-11. Here, we present crystallographic, kinetic and thermodynamic analyses of the binding site of such an antibody and that of its primary immunoglobulin ancestor. These show that these germline V-genes encode key side chain contacts with the viral antigen and thereby dictate key structural features of the hypermutated, high-affinity neutralizing antibody. V-genes may thus encode an innate, protective immunological memory that targets vulnerable, invariant sites on multiple pathogens.

  11. Cross-reactivity of human and bovine antibodies in striped dolphin paraffin wax-embedded tissues.

    Science.gov (United States)

    Jaber, J R; Fernández, A; Herráez, P; Espinosa de los Monteros, A; Ramírez, G A; García, P M; Fernández, T; Arbelo, M; Pérez, J

    2003-11-15

    This study evaluates the cross-reactivity of seven anti-human and one anti-bovine antibodies in formalin-fixed, paraffin-embedded tissue samples of liver and mesenteric lymph nodes of 13 striped dolphins (Stenella coeruleoalba). Four antibodies (CD3, IgG, lysozyme and S100 protein) reacted with striped dolphin lymph nodes in a similar pattern to that observed in the species of origin. The anti-human MHC class II mAb reacted strongly with macrophages and dendritic-like cells of striped dolphins, whereas a small number of lymphocytes were labelled with this antibody. These antibodies were used to study the immunophenotype of the inflammatory infiltrated in non-specific chronic reactive hepatitis (eight cases) and chronic parasite cholangitis (two cases) and normal liver (three cases) of striped dolphins. Non-specific chronic reactive hepatitis was composed of inflammatory infiltration of CD3+ T lymphocytes and IgG+ plasma cells in portal spaces and hepatic sinusoids. Lymphonodular aggregates observed in chronic parasitic cholangitis showed a cellular distribution similar to that found in lymph node cortex, including the presence of S100+ and MHC class II+ dendritic-like cells in lymphoid follicles and interfollicular areas. This result suggests that those inflammatory infiltrates are highly organised to enhance antigen presentation to B and T cells.

  12. Generation and characterization of a polyclonal antibody against human high mobility group box 4.

    Science.gov (United States)

    Yang, Fen; Li, Runsheng; Hong, Aizhen; Duan, Fei; Li, Yuhua

    2013-11-01

    A human high mobility group box 4 (hHMGB4) expression construct (pET‑28a/hHMGB4) was generated by cloning the hHMGB4 full‑length cDNA in the expression vector pET‑28a(+). The hHMGB4 fusion protein with His6‑Tag was prepared using E.coli BL21 (DE3) transformed with pET‑28a/hHMGB4 and purified via preparative SDS‑PAGE plus electroelution. Immunization of rabbits with the purified hHMGB4 generated polyclonal antibodies. The titer of the antiserum was determined to be 1:102,400 by ELISA analysis. Western blotting analysis showed that the antibody specifically recognized the recombinant hHMGB4 protein and also the endogenous hHMGB4 protein in prostate cancer cells. In addition, immunohistochemical staining analysis using the prepared antibody revealed marked hHMGB4 staining in the nuclei of the human prostate tissue. These data demonstrate that the anti‑hHMGB4 polyclonal antibody may be a useful reagent for the functional study of hHMGB4.

  13. The natural antibody repertoire of sharks and humans recognizes the potential universe of antigens.

    Science.gov (United States)

    Adelman, Miranda K; Schluter, Samuel F; Marchalonis, John J

    2004-02-01

    In ancestral sharks, a rapid emergence in the evolution of the immune system occurred, giving jawed-vertebrates the necessary components for the combinatorial immune response (CIR). To compare the natural antibody (NAb) repertoires of the most divergent vertebrates with the capacity to produce antibodies, we isolated NAbs to the same set of antigens by affinity chromatography from two species of Carcharhine sharks and from human polyclonal IgG and IgM antibody preparations. The activities of the affinity-purified anti-T-cell receptor (anti-TCR) NAbs were compared with those of monoclonal anti-TCR NAbs that were generated from a systemic lupus erythematosus patient. We report that sharks and humans, representing the evolutionary extremes of vertebrate species sharing the CIR, have NAbs to human TCRs, Igs, the human senescent cell antigen, and to numerous retroviral antigens, indicating that essential features of the combinatorial repertoire and the capacity to recognize the potential universe of antigens is shared among all jawed-vertebrates.

  14. The human liver-specific proteome defined by transcriptomics and antibody-based profiling.

    Science.gov (United States)

    Kampf, Caroline; Mardinoglu, Adil; Fagerberg, Linn; Hallström, Björn M; Edlund, Karolina; Lundberg, Emma; Pontén, Fredrik; Nielsen, Jens; Uhlen, Mathias

    2014-07-01

    Human liver physiology and the genetic etiology of the liver diseases can potentially be elucidated through the identification of proteins with enriched expression in the liver. Here, we combined data from RNA sequencing (RNA-Seq) and antibody-based immunohistochemistry across all major human tissues to explore the human liver proteome with enriched expression, as well as the cell type-enriched expression in hepatocyte and bile duct cells. We identified in total 477 protein-coding genes with elevated expression in the liver: 179 genes have higher expression as compared to all the other analyzed tissues; 164 genes have elevated transcript levels in the liver shared with at least one other tissue type; and an additional 134 genes have a mild level of increased expression in the liver. We identified the precise localization of these proteins through antibody-based protein profiling and the subcellular localization of these proteins through immunofluorescent-based profiling. We also identified the biological processes and metabolic functions associated with these proteins, investigated their contribution in the occurrence of liver diseases, and identified potential targets for their treatment. Our study demonstrates the use of RNA-Seq and antibody-based immunohistochemistry for characterizing the human liver proteome, as well as the use of tissue-specific proteins in identification of novel drug targets and discovery of biomarkers.-Kampf, C., Mardinoglu, A., Fagerberg, L., Hallström, B. M., Edlund, K., Lundberg, E., Pontén, F., Nielsen, J., Uhlen, M. The human liver-specific proteome defined by transcriptomics and antibody-based profiling. © FASEB.

  15. Antibody-Dependent Cell-Mediated Cytotoxicity Effector-Enhanced EphA2 Agonist Monoclonal Antibody Demonstrates Potent Activity against Human Tumors

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Bruckheimer

    2009-06-01

    Full Text Available EphA2 is a receptor tyrosine kinase that has been shown to be overexpressed in a variety of human tumor types. Previous studies demonstrated that agonist monoclonal antibodies targeting EphA2 induced the internalization and degradation of the receptor, thereby abolishing its oncogenic effects. In this study, the in vitro and in vivo antibody-dependent cell-mediated cytotoxicity (ADCC activity of EphA2 effector-enhanced agonist monoclonal antibodies was evaluated. With tumor cell lines and healthy human peripheral blood monocytes, the EphA2 antibodies demonstrated ∼80% tumor cell killing. In a dose-dependent manner, natural killer (NK cells were required for the in vitro ADCC activity and became activated as demonstrated by the induction of cell surface expression of CD107a. To assess the role of NK cells on antitumor efficacy in vivo, the EphA2 antibodies were evaluated in xenograft models in severe compromised immunodeficient (SCID mice (which have functional NK cells and monocytes and SCID nonobese diabetic (NOD mice (which largely lack functional NK cells and monocytes. Dosing of EphA2 antibody in the SCID murine tumor model resulted in a 6.2-fold reduction in tumor volume, whereas the SCID/nonobese diabetic model showed a 1.6-fold reduction over the isotype controls. Together, these results demonstrate that the anti-EphA2 monoclonal antibodies may function through at least two mechanisms of action: EphA2 receptor activation and ADCC-mediated activity. These novel EphA2 monoclonal antibodies provide additional means by which host effector mechanisms can be activated for selective destruction of EphA2-expressing tumor cells.

  16. Cross-reactive antibodies in convalescent SARS patients' sera against the emerging novel human coronavirus EMC (2012) by both immunofluorescent and neutralizing antibody tests.

    Science.gov (United States)

    Chan, Kwok-Hung; Chan, Jasper Fuk-Woo; Tse, Herman; Chen, Honglin; Lau, Candy Choi-Yi; Cai, Jian-Piao; Tsang, Alan Ka-Lun; Xiao, Xincai; To, Kelvin Kai-Wang; Lau, Susanna Kar-Pui; Woo, Patrick Chiu-Yat; Zheng, Bo-Jiang; Wang, Ming; Yuen, Kwok-Yung

    2013-08-01

    A severe acute respiratory syndrome (SARS)-like disease due to a novel betacoronavirus, human coronavirus EMC (HCoV-EMC), has emerged recently. HCoV-EMC is phylogenetically closely related to Tylonycteris-bat-coronavirus-HKU4 and Pipistrellus-bat-coronavirus-HKU5 in Hong Kong. We conducted a seroprevalence study on archived sera from 94 game-food animal handlers at a wild life market, 28 SARS patients, and 152 healthy blood donors in Southern China to assess the zoonotic potential and evidence for intrusion of HCoV-EMC and related viruses into humans. Anti-HCoV-EMC and anti-SARS-CoV antibodies were detected using screening indirect immunofluorescence (IF) and confirmatory neutralizing antibody tests. Two (2.1%) animal handlers had IF antibody titer of ≥ 1:20 against both HCoV-EMC and SARS-CoV with neutralizing antibody titer of SARS patients had significant IF antibody titers with 7/28 (25%) having anti-HCoV-EMC neutralizing antibodies at low titers which significantly correlated with that of HCoV-OC43. Bioinformatics analysis demonstrated a significant B-cell epitope overlapping the heptad repeat-2 region of Spike protein. Virulence of SARS-CoV over other betacoronaviruses may boost cross-reactive neutralizing antibodies against other betacoronaviruses. Convalescent SARS sera may contain cross-reactive antibodies against other betacoronaviruses and confound seroprevalence study for HCoV-EMC. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  17. Recognition of influenza H3N2 variant virus by human neutralizing antibodies

    Science.gov (United States)

    Bangaru, Sandhya; Nieusma, Travis; Kose, Nurgun; Thornburg, Natalie J.; Kaplan, Bryan S.; King, Hannah G.; Singh, Vidisha; Lampley, Rebecca M.; Cisneros, Alberto; Edwards, Kathryn M.; Edupuganti, Srilatha; Lai, Lilin; Richt, Juergen A.; Webby, Richard J.; Ward, Andrew B.; Crowe, James E.

    2016-01-01

    Since 2011, over 300 human cases of infection, especially in exposed children, with the influenza A H3N2 variant (H3N2v) virus that circulates in swine in the US have been reported. The structural and genetic basis for the lack of protection against H3N2v induced by vaccines containing seasonal H3N2 antigens is poorly understood. We isolated 17 human monoclonal antibodies (mAbs) that neutralized H3N2v virus from subjects experimentally immunized with an H3N2v candidate vaccine. Six mAbs exhibited very potent neutralizing activity (IC50 < 200 ng/ml) against the H3N2v virus but not against current human H3N2 circulating strains. Fine epitope mapping and structural characterization of antigen-antibody complexes revealed that H3N2v specificity was attributable to amino acid polymorphisms in the 150-loop and the 190-helix antigenic sites on the hemagglutinin protein. H3N2v-specific antibodies also neutralized human H3N2 influenza strains naturally circulating between 1995 and 2005. These results reveal a high level of antigenic relatedness between the swine H3N2v virus and previously circulating human strains, consistent with the fact that early human H3 seasonal strains entered the porcine population in the 1990s and reentered the human population, where they had not been circulating, as H3N2v about a decade later. The data also explain the increased susceptibility to H3N2v viruses in young children, who lack prior exposure to human seasonal strains from the 1990s. PMID:27482543

  18. An alternative chemical redox method for the production of bispecific antibodies: implication in rapid detection of food borne pathogens.

    Directory of Open Access Journals (Sweden)

    Mohammad Owais

    Full Text Available Bi-functional antibodies with the ability to bind two unrelated epitopes have remarkable potential in diagnostic and bio-sensing applications. In the present study, bispecific antibodies that recognize human red blood cell (RBC and the food borne pathogen Listeria monocytogenes (L. monocytogenes were engineered. The procedure involves initial reduction of a mixture of anti-RBC and anti-Listeria antibodies followed by gradual re-oxidation of the reduced disulphides. This facilitates association of the separated antibody chains and formation of hybrid immunoglobulins with affinity for the L. monocytogenes and human RBC. The bispecific antibodies caused the agglutination of the RBCs only in the presence of L. monocytogenes cells. The agglutination process necessitated the specific presence of L. monocytogenes and the red colored clumps formed were readily visible with naked eyes. The RBC agglutination assay described here provides a remarkably simple approach for the rapid and highly specific screening of various pathogens in their biological niches.

  19. Differences in the interaction of acetylcholine receptor antibodies with receptor from normal, denervated and myasthenic human muscle.

    OpenAIRE

    Lefvert, A. K.

    1982-01-01

    The interaction of acetylcholine receptor antibodies with different kinds of human skeletal muscle receptor was investigated. The reaction of most receptor antibodies was strongest with receptor from a patient with myasthenia gravis and with receptor from denervated muscle. Results obtained with these receptors were well correlated. The binding of most receptor antibodies to receptor from functionally normal muscle was much weaker and also qualitatively different. In a few patients with moder...

  20. Anti-enrofloxacin Antibody Production by Using Enrofloxacin-screened HSA as an Immunogen

    Institute of Scientific and Technical Information of China (English)

    LIU Chune; LIN Hong; CAO Limin; JIANG Jie

    2005-01-01

    A two-step zero-length cross-linking procedure using active esters was successfully adopted for conjugating enrofloxacin (EF) to human serum albumin (HSA). The derived conjugate was characterized by UV spectrum and then used for immunization of BALB/C mice. In enzyme-linked immunosorbent assay (ELISA) and competitive inhibition ELISA experiments, the derived antiserum exhibited high antibody titer (greater than 1: 250 000) as well as varied cross-reactivity (from 97.8% to 161.7%) to three analogs of EF belonging to fluoroquinolones family. But over the concentration range studied, no significant cross-reactivity was observed to other group of antibiotics (chloramphenicol, oxytetracycline, sulphamethoxazole and nysfungin). It was confirmed that the synthesized immunogen was highly antigenic and elicited specific antibody responses in BALB/C mice against EF.

  1. Production and Characterisation of Anti-Cardiac Troponin-I Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Kh. H. Haider

    1994-01-01

    Full Text Available Cardiac troponin-I (cTn-I was isolated from bovine left ventricular tissue and used as immunogen. Sixteen murine hybridoma lines were produced with two of them. I D 12 and 5F4, showing a high specificity for cTn-I; both of these monoclonal antibodies (McAbs were isotyped as IgG I with kappa - light chains. The specificity of the McAbs for cTn-1 was confirmed by ELISA, western blotting and by the ability of the antibodies to block actomyosin ATPase inhibition by cTn-I. The McAbs may be useful for human ill vivo imaging of myocardial infarcts and other pathological conditions related to cardiac myocyte damage.

  2. Assay interference caused by antibodies reacting with rat kappa light-chain in human sera.

    Science.gov (United States)

    Degn, Søren E; Andersen, Stig Henrik; Jensen, Lisbeth; Thiel, Steffen; Jensenius, Jens C

    2011-09-30

    The enzyme-linked immunosorbent assay (ELISA) and its derivatives are powerful tools used in research, in the clinic, and in many other analytical and quality control settings. In general, ELISAs are robust, reproducible and reliable. However, a number of pitfalls of ELISAs have been described over the years. The issue of rheumatoid factor (RF), autoantibodies against the Fc portion of IgG, is well recognized (yet often forgotten), as are problems arising from heterophilic antibodies induced by external antigens that cross-react with self-antigens. A few years ago focus was on human anti-mouse antibodies (HAMA) concomitant with the increased use of mouse monoclonal antibody therapy, a problem that is now diminishing due to development of humanized antibodies. Issues pertaining to food antigens or environmentally encountered antigens are less recognized. We report a recently encountered example of the latter resulting in interference in a solid-phase sandwich assay. Due to the set-up employing a monoclonal rat IgG for capture and a monoclonal rat IgM for development the interference had to be human antibodies reacting with rat light-chain. Out of 102 Danish Caucasian blood donors we found a prevalence of anti-rat kappa light chain antibodies of close to 40% (39/102, defined as at least 2-fold elevated measurements), with around 6% (6/102) having very high levels (defined as at least 4-fold elevated measurements), yielding significantly higher measurements in the assay designed to measure the complement component MAp19 in serum samples. The interference could be blocked by the addition of rat immunoglobulin to the sample buffer. An individual, who had been followed over time, demonstrated a periodic increase of interfering antibodies, highlighting that it is an independently varying parameter and thereby a variable interference in assays. Our results highlight a major pitfall of potential relevance to many sandwich-type assays, as well as an approach to rectify such

  3. SARS Patients-derived Human Recombinant Antibodies to S and M Proteins Efficiently Neutralize SARS-Coronavirus Infectivity

    Institute of Scientific and Technical Information of China (English)

    MI-FANG LIANG; KONG-XING WU; ZHAO-HUI XIONG; QI JIN; DE-XIN LI; RUN-LEI DU; JING-ZHI LIU; CHUAN LI; QUAN-FU ZHANG; LU-LU HAN; JIAN-SHI YU; SHU-MIN DUAN; XIAO-FANG WANG

    2005-01-01

    Objective To develop a specific SARS virus-targeted antibody preparation for emergent prophylaxis and treatment of SARS virus infection. Methods By using phage display technology, we constructed a naive antibody library from convalescent SARS patient lymphocytes. To obtain the neutralizing antibody to SARS virus surface proteins, the library panning procedure was performed on purified SARS virions and the specific Fab antibody clones were enriched by four rounds of repeated panning procedure and screened by highthroughput selection. The selected Fab antibodies expressed in the periplasma of E. Coli were soluble and further purified and tested for their binding properties and antiviral function to SARS virus. The functional Fab antibodies were converted to full human IgG antibodies with recombinant baculovirus/insect cell systems and their neutralizing activities were further determined. Results After four rounds of the panning, a number of SARS-CoV virus-targeted human recombinant Fab antibodies were isolated from the SARS patient antibody library. Most of these were identified to recognize both natural and recombinant SARS spike (S) proteins, two Fab antibodies were specific for the virus membrane (M) protein, only one bound to SARS-CoV nucleocapsid protein. The SARS-CoV S and M protein-targeted Fab or IgG antibodies showed significant neutralizing activities in cytopathic effect (CPE) inhibition neutralization test, these antibodies were able to completely neutralize the SARS virus and protect the Vero cells from CPE after virus infection. However, the N protein-targeted Fab or IgG antibodies failed to neutralize the virus. In addition, the SARS N protein-targeted human Fab antibody reacted with the denatured N proteins, whereas none of the S and M protein specific neutralizing antibodies did. These results suggested that the S and M protein-specific neutralizing antibodies could recognize conformational epitopes which might be involved in the binding of virions

  4. Natural and Immune Human Antibodies Reactive with Antigens of Virulent Neisseria gonorrhoeae: Immunoglobulins G, M, and A

    Science.gov (United States)

    Cohen, Irun R.

    1967-01-01

    Natural and immune human antibodies reactive with heat-labile and heat-stable antigens of virulent Neisseria gonorrhoeae were studied by use of an indirect fluorescent-antibody (IFA) procedure. The immunoglobulin class of the reactive antibodies was identified by using fluorescein-conjugated antisera specific for human IgG, IgA, or IgM in the IFA procedure. The effects of heat and mercaptoethanol on IFA reactivities were also studied. It appeared that antibodies of the IgG, IgM, and IgA classes present in the sera of both infected persons (immune antibodies) and normal persons with no history of gonococcal infection (natural antibodies) react with heat-stable somatic antigens. Immune IgG antibodies, however, were distinguishable from natural IgG antibodies by their ability to recognize heat-labile surface antigens. The distinction between natural and immune IgM antibodies was less obvious. IgM antibodies from both infected and normal persons appeared to react with heat-labile antigens. Some, but not all, infected persons had immune IgA antibodies to heat-labile as well as to heat-stable antigens. Treatment of sera with mercaptoethanol had no effect on IgG antibodies. The IFA activity of IgM antibodies was decreased, but not abolished. The effects of mercaptoethanol on IgA antibodies were variable. Some sera showed a decrease in IgA titer, and others showed an increase in IgA activity to certain antigens. Immune IgG antibodies were more resistant to heating than were natural IgG antibodies. Natural and immune IgM antibodies appeared equally sensitive to heating. IgA activity, on the other hand, was increased by heating sera at 60 C, but was decreased at higher temperatures. Thus, it appears that natural and immune human IgG antibodies to N. gonorrhoeae may be distinguished by their interactions with heat-labile antigens and by their resistance to heating. Images PMID:4961630

  5. Human Monoclonal Antibodies as Candidate Therapeutics Against Emerging Viruses and HIV-1

    Institute of Scientific and Technical Information of China (English)

    Zhongyu Zhu; Ponraj Prabakaran; Weizao Chen; Christopher C.Broder; Rui Gong; Dimiter S.Dimitrov

    2013-01-01

    More than 40 monoclonal antibodies (mAbs) have been approved for a number of disease indications with only one of these (Synagis)-for a viral disease,and not for therapy but for prevention.However,in the last decade novel potent mAbs have been discovered and characterized with potential as therapeutics against viruses of major importance for public health and biosecurity including Hendra virus (HeV),Nipah virus (NiV),severe acute respiratory syndrome coronavirus (SARS-CoV),Ebola virus (EBOV),West Nile virus (WNV),influenza virus (IFV) and human immunodeficiency virus type 1 (HIV-1).Here,we review such mAbs with an emphasis on antibodies of human origin,and highlight recent results as well as technologies and mechanisms related to their potential as therapeutics.

  6. Human monoclonal antibodies as candidate therapeutics against emerging viruses and HIV-1.

    Science.gov (United States)

    Zhu, Zhongyu; Prabakaran, Ponraj; Chen, Weizao; Broder, Christopher C; Gong, Rui; Dimitrov, Dimiter S

    2013-04-01

    More than 40 monoclonal antibodies (mAbs) have been approved for a number of disease indications with only one of these (Synagis) - for a viral disease, and not for therapy but for prevention. However, in the last decade novel potent mAbs have been discovered and characterized with potential as therapeutics against viruses of major importance for public health and biosecurity including Hendra virus (HeV), Nipah virus (NiV), severe acute respiratory syndrome coronavirus (SARS-CoV), Ebola virus (EBOV), West Nile virus (WNV), influenza virus (IFV) and human immunodeficiency virus type 1 (HIV-1). Here, we review such mAbs with an emphasis on antibodies of human origin, and highlight recent results as well as technologies and mechanisms related to their potential as therapeutics.

  7. Defective TFH Cell Function and Increased TFR Cells Contribute to Defective Antibody Production in Aging.

    Science.gov (United States)

    Sage, Peter T; Tan, Catherine L; Freeman, Gordon J; Haigis, Marcia; Sharpe, Arlene H

    2015-07-14

    Defective antibody production in aging is broadly attributed to immunosenescence. However, the precise immunological mechanisms remain unclear. Here, we demonstrate an increase in the ratio of inhibitory T follicular regulatory (TFR) cells to stimulatory T follicular helper (TFH) cells in aged mice. Aged TFH and TFR cells are phenotypically distinct from those in young mice, exhibiting increased programmed cell death protein-1 expression but decreased ICOS expression. Aged TFH cells exhibit defective antigen-specific responses, and programmed cell death protein-ligand 1 blockade can partially rescue TFH cell function. In contrast, young and aged TFR cells have similar suppressive capacity on a per-cell basis in vitro and in vivo. Together, these studies reveal mechanisms contributing to defective humoral immunity in aging: an increase in suppressive TFR cells combined with impaired function of aged TFH cells results in reduced T-cell-dependent antibody responses in aged mice.

  8. Defective TFH Cell Function and Increased TFR Cells Contribute to Defective Antibody Production in Aging

    Directory of Open Access Journals (Sweden)

    Peter T. Sage

    2015-07-01

    Full Text Available Defective antibody production in aging is broadly attributed to immunosenescence. However, the precise immunological mechanisms remain unclear. Here, we demonstrate an increase in the ratio of inhibitory T follicular regulatory (TFR cells to stimulatory T follicular helper (TFH cells in aged mice. Aged TFH and TFR cells are phenotypically distinct from those in young mice, exhibiting increased programmed cell death protein-1 expression but decreased ICOS expression. Aged TFH cells exhibit defective antigen-specific responses, and programmed cell death protein-ligand 1 blockade can partially rescue TFH cell function. In contrast, young and aged TFR cells have similar suppressive capacity on a per-cell basis in vitro and in vivo. Together, these studies reveal mechanisms contributing to defective humoral immunity in aging: an increase in suppressive TFR cells combined with impaired function of aged TFH cells results in reduced T-cell-dependent antibody responses in aged mice.

  9. A sulfanyl-PEG derivative of relaxin-like peptide utilizable for the conjugation with KLH and the antibody production.

    Science.gov (United States)

    Katayama, Hidekazu; Mita, Masatoshi

    2016-08-15

    A small peptide-keyhole limpet hemocyanin (KLH) conjugate is generally used as an antigen for producing specific antibodies. However, preparation of a disulfide-rich heterodimeric peptide-KLH conjugates is difficult. In this study, we developed a novel method for preparation of the conjugate, and applied it to the production of specific antibodies against the relaxin-like gonad-stimulating peptide (RGP) from the starfish. In this method, a sulfanyl group necessary for the conjugation with KLH was site-specifically introduced to the peptide after regioselective disulfide bond formation reactions. Using the conjugate, we could obtain specific antibodies with a high antibody titer. This method might also be useful for the production of antibodies against other heterodimeric peptides with disulfide cross-linkages, such as vertebrate relaxins.

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

    Directory of Open Access Journals (Sweden)

    Pablo D Becker

    Full Text Available BACKGROUND: 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 potentially altering antigenic specificity and/or affinity. The immortalization of human B cells represents an alternative for obtaining human mAbs, but relies on the availability of biological samples from vaccinated individuals or convalescent patients. In this work we describe a novel approach to generate fully human mAbs by combining a humanized mouse model with a new B cell immortalization technique. METHODOLOGY/PRINCIPAL FINDINGS: After transplantation with CD34+CD38⁻ human hematopoietic progenitor cells, BALB/c Rag2⁻/⁻IL-2Rγc⁻/⁻ mice acquire a human immune system and harbor B cells with a diverse IgM repertoire. "Human Immune System" mice were then immunized with two commercial vaccine antigens, tetanus toxoid and hepatitis B surface antigen. Sorted human CD19+CD27+ B cells were retrovirally transduced with the human B cell lymphoma (BCL-6 and BCL-XL genes, and subsequently cultured in the presence of CD40-ligand and IL-21. This procedure allows generating stable B cell receptor-positive B cells that secrete immunoglobulins. We recovered stable B cell clones that produced IgM specific for tetanus toxoid and the hepatitis B surface antigen, respectively. CONCLUSION/SIGNIFICANCE: This work provides the proof-of-concept for the usefulness of this novel method based on the immunization of humanized mice for the rapid generation of human mAbs against a wide range of antigens.

  11. Construction of Large Human Single-chain Antibody Phage Display Library

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A large human naive single chain antibody (scFv) library is constructed from 60 healthy donors via phage display technique. During the period, some methods are employed to optimize the diversity, such as multi donors, different annealing temperature, half-nest PCR, and assembly by two-way fusion PCR. In this stud y, 78 electroporations resulted in 1010 library, diversity of which is assayed by enzyme fingerprint. The efficiency and diversity are all better than other rese arches.

  12. Direct evidence that the VEGF-specific antibody bevacizumab has antivascular effects in human rectal cancer

    OpenAIRE

    2004-01-01

    The effects of vascular endothelial growth factor (VEGF) blockade on the vascular biology of human tumors are not known. Here we show here that a single infusion of the VEGF-specific antibody bevacizumab decreases tumor perfusion, vascular volume, microvascular density, interstitial fluid pressure and the number of viable, circulating endothelial and progenitor cells, and increases the fraction of vessels with pericyte coverage in rectal carcinoma patients. These data indicate that VEGF block...

  13. Differential expression of anti-glycan antibodies in schistosome-infected humans, rhesus monkeys and mice

    Science.gov (United States)

    Luyai, Anthony E; Heimburg-Molinaro, Jamie; Prasanphanich, Nina Salinger; Mickum, Megan L; Lasanajak, Yi; Song, Xuezheng; Nyame, A Kwame; Wilkins, Patricia; Rivera-Marrero, Carlos A; Smith, David F; Van Die, Irma; Secor, W Evan; Cummings, Richard D

    2014-01-01

    Schistosomiasis is a debilitating parasitic disease of humans, endemic in tropical areas, for which no vaccine is available. Evidence points to glycan antigens as being important in immune responses to infection. Here we describe our studies on the comparative humoral immune responses to defined schistosome-type glycan epitopes in Schistosoma mansoni-infected humans, rhesus monkeys and mice. Rhesus anti-glycan responses over the course of infection were screened on a defined glycan microarray comprising semi-synthetic glycopeptides terminating with schistosome-associated or control mammalian-type glycan epitopes, as well as a defined glycan microarray of mammalian-type glycans representing over 400 glycan structures. Infected rhesus monkeys generated a high immunoglobulin G (IgG) antibody response to the core xylose/core α3 fucose epitope of N-glycans, which peaked at 8–11 weeks post infection, coinciding with maximal ability to kill schistosomula in vitro. By contrast, infected humans generated low antibody levels to this epitope. At 18 months following praziquantel therapy to eliminate the parasite, antibody levels were negligible. Mice chronically infected with S. mansoni generated high levels of anti-fucosylated LacdiNAc (GalNAcβ1, 4(Fucα1, 3)GlcNAc) IgM antibodies, but lacked a robust response to the core xylose/core α3 fucose N-glycan antigens compared with other species studied, and their sera demonstrated an intermediate level of schistosomula killing in vitro. These differential responses to parasite glycan antigens may be related to the ability of rhesus monkeys to self-cure in contrast to the chronic infection seen in humans and mice. Our results validate defined glycan microarrays as a useful technology to evaluate diagnostic and vaccine antigens for schistosomiasis and perhaps other infections. PMID:24727442

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

    Directory of Open Access Journals (Sweden)

    Xiaodong Xiao

    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.

  15. Development of next generation antivenoms based on mixtures of human antibodies

    DEFF Research Database (Denmark)

    Knudsen, Cecilie; Andersen, Mikael Rørdam; Harrison, Robert

    With an annual 150,000 deaths and countless amputations and disfigurements,snakebite envenoming is an ever-present threat in many parts of the rural tropicalworld. In sub-Saharan Africa, only 1-2% of victims are treated with antivenom,which is currently based on animal-derived antibodies. Due to ...... to their heterologousorigin, antivenoms often provoke serious side effects in human recipients, such asserum sickness and anaphylaxis, which in some cases leads to death....

  16. Antibodies against human BLyS and APRIL attenuate EAE development in marmoset monkeys.

    Science.gov (United States)

    Jagessar, S Anwar; Heijmans, Nicole; Oh, Luke; Bauer, Jan; Blezer, Erwin L A; Laman, Jon D; Migone, Thi-Sau; Devalaraja, Matt N; 't Hart, Bert A

    2012-09-01

    B lymphocyte stimulator (BLyS, also indicated as BAFF (B-cell activating factor) and CD257), and A Proliferation Inducing Ligand (APRIL, CD256) are two members of the TNF superfamily with a central role in B cell survival. Antibodies against these factors have potential therapeutic relevance in autoimmune inflammatory disorders with a proven pathogenic contribution of B cells, such as multiple sclerosis (MS). In the current study we performed a multi-parameter efficacy comparison of monoclonal antibodies against human anti-BLyS and anti-APRIL in a common marmoset (Callithrix jacchus) model of experimental autoimmune encephalomyelitis (EAE). A MS-like disease was induced by immunization with recombinant human myelin/oligodendrocyte glycoprotein (rhMOG) in complete Freund's adjuvant. The results show that the anti-BLyS and anti-APRIL antibody cause significant depletion of circulating CD20+ B cells, but a small subset of CD20 + CD40(high) B cells was not depleted. Induction of CD20+ B cell depletion from lymph nodes was only observed in the anti-BLyS treated monkeys. Both antibodies had a significant inhibitory effect on disease development, but all monkeys developed clinically evident EAE. Anti-BLyS treated monkeys were sacrificed with the same clinical signs as saline-treated monkeys, but nevertheless displayed significantly reduced spinal cord demyelination. This effect was not observed in the anti-APRIL treated monkeys. The two antibodies had a different effect on T cell subset activation and the profiles of ex vivo released cytokines. In conclusion, treatment with anti-BLyS and anti-APRIL delays the development of neurological disease in a relevant preclinical model of MS. The two mAbs achieve this effect via different mechanisms.

  17. 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.

  18. Interactions between Lipids and Human Anti-HIV Antibody 4E10 Can Be Reduced without Ablating Neutralizing Activity

    NARCIS (Netherlands)

    Xu, Hengyu; Song, Likai; Kim, Mikyung; Holmes, Margaret A.; Kraft, Zane; Sellhorn, George; Reinherz, Ellis L.; Stamatatos, Leonidas; Strong, Roland K.

    2010-01-01

    Human 4E10 is one of the broadest-specificity, HIV-1-neutralizing monoclonal antibodies known, recognizing a membrane-proximal linear epitope on gp41. The lipid cross-reactivity of 4E10 has been alternately suggested either to contribute to the apparent rarity of 4E10-like antibody responses in HIV

  19. Molecular characterization of the variable heavy and light chain regions of five HIV-1 specific human monoclonal antibodies.

    NARCIS (Netherlands)

    E.M.M. van der Donk; M. Schutten (Martin); A.D.M.E. Osterhaus (Albert); R.W.J. van der Heijden (Roger)

    1994-01-01

    textabstractWe have reported the generation and characterization of four HIV-1 neutralizing human monoclonal antibodies. Three antibodies recognize a conformational epitope within the CD4-binding site of HIV-1 gp120 and one recognizes a linear epitope located within the hypervariable V3 domain of gp

  20. Therapeutic use of avidin is not hampered by antiavidin antibodies in humans.

    Science.gov (United States)

    Petronzelli, Fiorella; Pelliccia, Angela; Anastasi, Anna Maria; Lindstedt, Ragnar; Manganello, Stefania; Ferrari, Liliana Elisa; Albertoni, Claudio; Leoni, Barbara; Rosi, Antonio; D'Alessio, Valeria; Deiana, Katia; Paganelli, Giovanni; De Santis, Rita

    2010-10-01

    Hen egg white avidin is increasingly used in the clinic as part of multifactor treatments such as pretargeted radionuclide therapy of cancer or as an antidote of biotinylated drugs. Taking into account that naturally occurring human antiavidin antibodies (HAVA) are common in humans, the present work investigates avidin immunogenicity as part of risk/benefit evaluations. Sera from 139 oncology patients naive to avidin were confirmed to exhibit HAVA with lognormally distributed titers. HAVA were boosted after avidin treatment, with no correlation with the avidin dose or with the basal titer. No antibody-related clinical symptoms were observed in 21 HAVA-positive patients treated with avidin. In mouse models, high mouse antiavidin antibody titers, induced to simulate the worst human condition, neither reduced the biotin uptake of intratissue-injected avidin nor affected the capacity of intravenously injected avidin to clear a biotinylated drug from circulation. In both models the avidin treatment was well tolerated. Results indicate that avidin immunogenicity does not affect its safety and efficacy, thus encouraging its further use in clinical applications.

  1. Cloning and Sequence Analysis of Light Variable Region Gene of Anti-human Retinoblastoma Monoclonal Antibody

    Institute of Scientific and Technical Information of China (English)

    Xiufeng Zhong; Yongping Li; Shuqi Huang; Bo Ning; Chunyan Zhang; Jianliang Zheng; Guanguang Feng

    2002-01-01

    Purpose: To clone the variable region gene of light chain of monoclonal antibody against human retinoblastoma and to analyze the characterization of its nucleotide sequence as well as amino acid sequence.Methods: Total RNA was extracted from 3C6 hybridoma cells secreting specific monoclonal antibody(McAb)against human retinoblastoma(RB), then transcripted reversely into cDNA with olig-dT primers.The variable region of the light chain (VL) gene fragments was amplified using polymeerase chain reaction(PCR) and further cloned into pGEM(R) -T Easy vector. Then, 3C6 VL cDNA was sequenced by Sanger's method.Homologous analysis was done by NCBI BLAST.Results: The complete nucleotide sequence of 3C6 VL cDNA consisted of 321 bp encoding 107 amino acid residues, containing four workframe regions(FRs)and three complementarity-determining regions (CDRs) as well as the typical structure of two cys residues. The sequence is most homological to a member of the Vk9 gene family, and its chain utilizes the Jkl gene segment.Conclusion: The light chain variable region gene of the McAb against human RB was amplified successfully , which belongs to the Vk9 gene family and utilizes Vk-Jk1 gene rearrangement. This study lays a good basis for constructing a recombinant antibody and for making a new targeted therapeutic agents against retinoblastoma.

  2. 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.

  3. Thymus cells in myasthenia gravis selectively enhance production of anti-acetylcholine-receptor antibody by autologous blood lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Newsom-Davis, J.; Willcox, N.; Calder, L.

    1981-11-26

    We investigated the role of the thymus in 16 patients with myasthenia gravis without thymoma by studying the production of anti-acetylcholine-receptor antibody by thymic and blood lymphocytes cultured alone or together. In 10 responders (with the highest receptor-antibody titers in their plasma), cultured thymic cells spontaneously produced measurable receptor antibody. Receptor-antibody production by autologous blood lymphocytes was enhanced by the addition of responder's thymic cells, irradiated to abrogate antibody production and suppression (P<0.01). This enhancement was greater and more consistent than that by pokeweed mitogen; it depended on viable thymic cells, appeared to be selective for receptor antibody, and correlated with the ratio of thymic helper (OKT4-positive or OKT4+) to suppressor (OKT8+) T cells (P<0.01). These results suggest that myasthenic thymus contains cell-bound acetylcholine-receptor-like material or specific T cells (or both) that can aid receptor-antibody production. This may be relevant to the benefits of thymectomy in myasthenia and to the breakdown in self-tolerance in this and other autoimmune diseases.

  4. [Immune response genes products in human physiology].

    Science.gov (United States)

    Khaitov, R M; Alekseev, L P

    2012-09-01

    Current data on physiological role of human immune response genes' proteomic products (antigens) are discussed. The antigens are specified by a very high level of diversity that mediates a wide specter ofphysiological functions. They actually provide integrity and biological stability of human as species. These data reveal new ideas on many pathological processes as well as drafts new approaches for prophylaxis and treatment.

  5. Novel receptor-derived cyclopeptides to treat heart failure caused by anti-β1-adrenoceptor antibodies in a human-analogous rat model.

    Directory of Open Access Journals (Sweden)

    Valérie Boivin

    Full Text Available Despite recent therapeutic advances the prognosis of heart failure remains poor. Recent research suggests that heart failure is a heterogeneous syndrome and that many patients have stimulating auto-antibodies directed against the second extracellular loop of the β1 adrenergic receptor (β1EC2. In a human-analogous rat model such antibodies cause myocyte damage and heart failure. Here we used this model to test a novel antibody-directed strategy aiming to prevent and/or treat antibody-induced cardiomyopathy. To generate heart failure, we immunised n = 76/114 rats with a fusion protein containing the human β1EC2 (amino-acids 195-225 every 4 weeks; n = 38/114 rats were control-injected with 0.9% NaCl. Intravenous application of a novel cyclic peptide mimicking β1EC2 (β1EC2-CP, 1.0 mg/kg every 4 weeks or administration of the β1-blocker bisoprolol (15 mg/kg/day orally was initiated either 6 weeks (cardiac function still normal, prevention-study, n = 24 (16 treated vs. 8 untreated or 8.5 months after the 1st immunisation (onset of cardiomyopathy, therapy-study, n = 52 (40 treated vs. 12 untreated; n = 8/52 rats from the therapy-study received β1EC2-CP/bisoprolol co-treatment. We found that β1EC2-CP prevented and (alone or as add-on drug treated antibody-induced cardiac damage in the rat, and that its efficacy was superior to mono-treatment with bisoprolol, a standard drug in heart failure. While bisoprolol mono-therapy was able to stop disease-progression, β1EC2-CP mono-therapy -or as an add-on to bisoprolol- almost fully reversed antibody-induced cardiac damage. The cyclo¬peptide acted both by scavenging free anti-β1EC2-antibodies and by targeting β1EC2-specific memory B-cells involved in antibody-production. Our model provides the basis for the clinical translation of a novel double-acting therapeutic strategy that scavenges harmful anti-β1EC2-antibodies and also selectively depletes memory B-cells involved in the production of such

  6. 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.

  7. Detection of anti-liver cell membrane antibody using a human hepatocellular carcinoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Lobo-Yeo, A.; McSorley, C.; McFarlane, B.M.; Mieli-Vergani, G.; Mowat, A.P.; Vergani, D.

    1989-02-01

    A radioimmunometric technique for the detection of autoantibodies to liver membrane antigens has been developed using Alexander cells, a human hepatocellular carcinoma cell line. After incubation of Alexander cells with serum, antimembrane antibodies were detected by addition of /sup 125/I-labeled Protein A. Binding ratios in 15 children with uncontrolled autoimmune chronic active hepatitis and in seven children with primary sclerosing cholangitis were significantly higher than in 18 age-matched normal controls. Nine patients with inactive autoimmune chronic active hepatitis, 13 with alpha 1-antitrypsin deficiency and five with fulminant hepatic failure had ratios similar to controls. In nine patients with Wilson's disease, there was a modest but significant increase in binding ratio. In four children with autoimmune chronic active hepatitis, binding ratios fell during effective immunosuppressive therapy. Sera from patients with systemic lupus erythematosus or rheumatoid arthritis gave normal results, excluding that binding derives from Fc-mediated immune complex capture. A positive correlation was found between Alexander cell binding values and anti-liver-specific protein antibody titers, suggesting that the two assays detect antibodies against shared antigenic determinants. The Alexander cell assay is a simple, rapid and sensitive technique to detect antibody to liver cell membrane antigens.

  8. 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.).

  9. Secretion of respiratory syncytial virus inhibitors and antibody in human milk throughout lactation.

    Science.gov (United States)

    Toms, G L; Gardner, P S; Pullan, C R; Scott, M; Taylor, C

    1980-01-01

    Neutralising inhibitors to respiratory syncytial (RS) virus have been demonstrated in the whey of most samples of human milk tested. Although high titres were secreted in colostra of some mothers (1/10-1/2,560; median 1/40) inhibitor levels in milk collected after the first week of lactation were uniformly low (median 1/10). High neutralising titres correlated with high colostral levels of specific antiviral IgA but, unlike neutralising activity, IgA antiviral antibody persisted in the milk of only four of 18 mothers. Similarly, antiviral IgG and IgM antibodies were not generally detected after the first post-partum week. Differences in antibody secretion among mothers did not correlate with differences in total protein or total immunoglobulin secretion, and appeared to reflect maternal immune status. In one mother a marked rise in specific antiviral IgA and IgG secretions during the second and third months of lactation suggested a response to virus infection. The relevance of maternal immunity and colostral and milk antiviral antibody to protection of breast-fed babies from RS-virus bronchiolitis is discussed.

  10. Identification and characterization of human eosinophil cationic protein by an epitope-specific antibody.

    Science.gov (United States)

    Boix, E; Carreras, E; Nikolovski, Z; Cuchillo, C M; Nogués, M V

    2001-06-01

    The eosinophil cationic protein (ECP) is a basic secretion protein involved in the immune response system. ECP levels in biological fluids are an indicator of eosinophil-specific activation and degranulation and are currently used for the clinical monitoring and diagnosis of inflammatory disorders. A polyclonal epitope-specific antibody has been obtained by immunizing rabbits with a conjugated synthetic peptide. A sequence corresponding to a large exposed loop in the human ECP three-dimensional structure (D115-Y122) was selected as a putative antigenic epitope. The antibody was purified on an affinity column using recombinant ECP (rECP) as antigen. The antibody (D112-P123 Ab) specifically recognizes rECP and its native glycosylated and nonglycosylated forms in plasma, granulocytes, and sputum. The antibody detects as little as 1 ng of rECP, can be used both in reducing and nonreducing conditions, and does not cross-react with the highly homologous eosinophil-derived neurotoxin or other proteins of the pancreatic ribonuclease superfamily.

  11. Human Factors in the Management of Production

    DEFF Research Database (Denmark)

    Jensen, Per Langå; Alting, Leo

    2006-01-01

    challenges. Qualitative interviews with Danish stakeholders in the education of engineers (BA & MA) confirm the picture given in international literature. Therefore, the didactics concerning the ‘human factor’ in the curriculum on production management has to reflect these changes. This paper concludes...... with a proposal on essential issues to be addressed in the curriculum qualifying university candidates to production management....

  12. Investigating human infant anthropomorphism in products

    NARCIS (Netherlands)

    Hellen, K.; Saaksjarvi, M.C.

    2012-01-01

    In this paper we set out to investigate the nature and effects of infant anthropomorphism in products, i.e. products that share features of human infants. Across four studies, evidence suggests that infant anthropomorphism comprise four dimensions: sweetness, simplicity, sympathy, and smallness. We

  13. Construction of a Semisynthetic Human VH Single-Domain Antibody Library and Selection of Domain Antibodies against α-Crystalline of Mycobacterium tuberculosis.

    Science.gov (United States)

    Hairul Bahara, Nur Hidayah; Chin, Siang Tean; Choong, Yee Siew; Lim, Theam Soon

    2016-01-01

    The use of human variable heavy (VH) domain antibodies has been on the rise due to their small scaffold size and simple folding mechanism. A highly diverse library is largely dependent on the diversity introduced within the complementarity-determining region (CDR) cassettes. Here we introduced diversity with the use of a single framework diversifying all three CDRs using tailored codons consisting of degenerate trinucleotides (NNK). The length of the degeneracy in the CDRs was also taken into consideration based on the most frequently occurring length of CDRs and the canonical confirmation for each antibody subfamily. The semisynthetic human VH domain genes were assembled in a single pot using a temperature cascading process. The affinity selection process with Mycobacterium tuberculosis (MTb) α-crystalline was done using a semiautomated process. Enrichment of target-specific clones was observed with successful identification of monoclonal VH domain antibodies for MTb α-crystalline. In short, the semisynthetic library generated was able to select monoclonal VH domain antibodies against full MTb α-crystalline protein with complete semisynthetic CDRs displayed on a single scaffold. The library has the potential to be applied for the isolation of antibodies against other pathogenic proteins.

  14. Contribution of V(H replacement products in mouse antibody repertoire.

    Directory of Open Access Journals (Sweden)

    Lin Huang

    Full Text Available VH replacement occurs through RAG-mediated recombination between the cryptic recombination signal sequence (cRSS near the 3' end of a rearranged VH gene and the 23-bp RSS from an upstream unrearranged VH gene. Due to the location of the cRSS, VH replacement leaves a short stretch of nucleotides from the previously rearranged VH gene at the newly formed V-D junction, which can be used as a marker to identify VH replacement products. To determine the contribution of VH replacement products to mouse antibody repertoire, we developed a Java-based VH Replacement Footprint Analyzer (VHRFA program and analyzed 17,179 mouse IgH gene sequences from the NCBI database to identify VH replacement products. The overall frequency of VH replacement products in these IgH genes is 5.29% based on the identification of pentameric VH replacement footprints at their V-D junctions. The identified VH replacement products are distributed similarly in IgH genes using most families of VH genes, although different families of VH genes are used differentially. The frequencies of VH replacement products are significantly elevated in IgH genes derived from several strains of autoimmune prone mice and in IgH genes encoding autoantibodies. Moreover, the identified VH replacement footprints in IgH genes from autoimmune prone mice or IgH genes encoding autoantibodies preferentially encode positively charged amino acids. These results revealed a significant contribution of VH replacement products to the diversification of antibody repertoire and potentially, to the generation of autoantibodies in mice.

  15. Direct evidence that the VEGF-specific antibody bevacizumab has antivascular effects in human rectal cancer

    Science.gov (United States)

    Willett, Christopher G; Boucher, Yves; di Tomaso, Emmanuelle; Duda, Dan G; Munn, Lance L; Tong, Ricky T; Chung, Daniel C; Sahani, Dushyant V; Kalva, Sanjeeva P; Kozin, Sergey V; Mino, Mari; Cohen, Kenneth S; Scadden, David T; Hartford, Alan C; Fischman, Alan J; Clark, Jeffrey W; Ryan, David P; Zhu, Andrew X; Blaszkowsky, Lawrence S; Chen, Helen X; Shellito, Paul C; Lauwers, Gregory Y; Jain, Rakesh K

    2009-01-01

    The effects of vascular endothelial growth factor (VEGF) blockade on the vascular biology of human tumors are not known. Here we show here that a single infusion of the VEGF-specific antibody bevacizumab decreases tumor perfusion, vascular volume, microvascular density, interstitial fluid pressure and the number of viable, circulating endothelial and progenitor cells, and increases the fraction of vessels with pericyte coverage in rectal carcinoma patients. These data indicate that VEGF blockade has a direct and rapid antivascular effect in human tumors. PMID:14745444

  16. Development of a mouse monoclonal antibody cocktail for post-exposure rabies prophylaxis in humans.

    Directory of Open Access Journals (Sweden)

    Thomas Müller

    Full Text Available As the demand for rabies post-exposure prophylaxis (PEP treatments has increased exponentially in recent years, the limited supply of human and equine rabies immunoglobulin (HRIG and ERIG has failed to provide the required passive immune component in PEP in countries where canine rabies is endemic. Replacement of HRIG and ERIG with a potentially cheaper and efficacious alternative biological for treatment of rabies in humans, therefore, remains a high priority. In this study, we set out to assess a mouse monoclonal antibody (MoMAb cocktail with the ultimate goal to develop a product at the lowest possible cost that can be used in developing countries as a replacement for RIG in PEP. Five MoMAbs, E559.9.14, 1112-1, 62-71-3, M727-5-1, and M777-16-3, were selected from available panels based on stringent criteria, such as biological activity, neutralizing potency, binding specificity, spectrum of neutralization of lyssaviruses, and history of each hybridoma. Four of these MoMAbs recognize epitopes in antigenic site II and one recognizes an epitope in antigenic site III on the rabies virus (RABV glycoprotein, as determined by nucleotide sequence analysis of the glycoprotein gene of unique MoMAb neutralization-escape mutants. The MoMAbs were produced under Good Laboratory Practice (GLP conditions. Unique combinations (cocktails were prepared, using different concentrations of the MoMAbs that were capable of targeting non-overlapping epitopes of antigenic sites II and III. Blind in vitro efficacy studies showed the MoMab cocktails neutralized a broad spectrum of lyssaviruses except for lyssaviruses belonging to phylogroups II and III. In vivo, MoMAb cocktails resulted in protection as a component of PEP that was comparable to HRIG. In conclusion, all three novel combinations of MoMAbs were shown to have equal efficacy to HRIG and therefore could be considered a potentially less expensive alternative biological agent for use in PEP and prevention of

  17. 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.

  18. Production of Polyclonal Antibody against Grapevine fanleaf virus Movement Protein Expressed in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Davoud Koolivand

    2016-10-01

    Full Text Available The genomic region of Grapevine fanleaf virus (GFLV encoding the movement protein (MP was cloned into pET21a and transformed into Escherichia coli strain BL21 (DE3 to express the protein. Induction was made with a wide range of isopropyl-β-D-thiogalactopyranoside (IPTG concentrations (1, 1.5, and 2 mM each for duration of 4, 6, or 16 h. However, the highest expression level was achieved with 1 mM IPTG for 4 h. Identity of the expressed protein was confirmed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE followed by Western blotting. The expressed 41 kDa protein was purified under denaturing condition by affinity chromatography, reconfirmed by Western blotting and plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA before being used as a recombinant antigen to raise polyclonal antibodies in rabbits. Purified anti-GFLV MP immunoglobulines (IgGs and conjugated IgGs detected the expressed MP and GFLV virions in infected grapevines when used in PTA-ELISA, double antibody sandwich-ELISA, and Western blotting. This is the first report on the production of anti-GFLV MP polyclonal antibodies and application for the virus detection.

  19. 15th International Conference on Human Antibodies and Hybridomas. 14-16 April 2010, Tiara Park Atlantico Hotel, Porto, Portugal.

    Science.gov (United States)

    Kotlan, Beatrix

    2010-11-01

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

  20. Development of a sensitive and specific epitope-blocking ELISA for universal detection of antibodies to human enterovirus 71 strains.

    Directory of Open Access Journals (Sweden)

    Fang He

    Full Text Available BACKGROUND: Human Enterovirus 71 (EV71 is a common cause of hand, foot and mouth disease (HFMD in young children. It is often associated with severe neurological diseases and mortalities in recent outbreaks across the Asia Pacific region. Currently, there is no efficient universal antibody test available to detect EV71 infections. METHODOLOGY/PRINCIPAL FINDING: In the present study, an epitope-blocking ELISA was developed to detect specific antibodies to human EV71 viruses in human or animal sera. The assay relies on a novel monoclonal antibody (Mab 1C6 that specifically binds to capsid proteins in whole EV71 viruses without any cross reaction to any EV71 capsid protein expressed alone. The sensitivity and specificity of the epitope-blocking ELISA for EV71 was evaluated and compared to microneutralization using immunized animal sera to multiple virus genotypes of EV71 and coxsackieviruses. Further, 200 serum sample from human individuals who were potentially infected with EV71 viruses were tested in both the blocking ELISA and microneutralization. Results indicated that antibodies to EV71 were readily detected in immunized animals or human sera by the epitope blocking ELISA whereas specimens with antibodies to other enteroviruses yielded negative results. This assay is not only simpler to perform but also shows higher sensitivity and specificity as compared to microneutralization. CONCLUSION: The epitope-blocking ELISA based on a unique Mab 1C6 provided highly sensitive and 100% specific detection of antibodies to human EV71 viruses in human sera.

  1. Development of a PBPK model for monoclonal antibodies and simulation of human and mice PBPK of a radiolabelled monoclonal antibody.

    Science.gov (United States)

    Heiskanen, Tomi; Heiskanen, Tomas; Kairemo, Kalevi

    2009-01-01

    Physiology based pharmacokinetic (PBPK) modeling and simulation is a useful method for prediction of biodistribution of both macromolecules and small molecules. It can enhance our understanding of the underlying mechanisms of biodistribution and hence may help in rational design of macromolecules used as diagnostic and therapeutic agents. In this review we discuss PBPK modeling and simulation of a radiolabelled Monoclonal Antibody ((111)In-DOTA-hAFP31 IgG) ("MAB") in mice without tumor and in a human with tumor. This study is part of Xemet Co.'s effort to develop a more accurate and reliable PBPK model and simulation platform, which is applicable both for small molecules and macromolecules. The simulated results were fitted to experimental time series data by varying parameters which were not fixed a priori. It was demonstrated that the PBPK model describes the main features of the pharmacokinetics of the studied systems. It was also shown that simulation can be used for evaluating the parameters of the system and scaling up the pharmacokinetics of MAB from mice to man. We identified several areas of improvement and further development needed to improve the accuracy of PBPK simulation for MAB and other macromolecules. It was concluded that the transvascular permeabilities are the most important parameters and more research is needed to enable prediction of permeabilities from molecular characteristics of macromolecules. It would also be necessary to understand better and describe with a more detailed model the microstructure of the tumor and to measure or predict the antigen concentration in tumor. Non-specific, non-saturable binding in other organs/tissues should be understood better and the kinetic constants of the binding should be measured experimentally. Although the metabolism and clearance were neglected in this study they need to be included in more detailed studies. Also the intracellular trafficking of macromolecules, which was not included in this study

  2. {sup 90}Nb - a potential PET nuclide. Production and labeling of monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Radchenko, V.; Roesch, F. [Mainz Univ. (Germany). Inst. of Nuclear Chemistry; Hauser, H.; Eisenhut, M. [German Cancer Research Center, Heidelberg (Germany). Radiopharmaceutical Chemistry; Vugts, D.J.; Dongen, G.A.M.S. van [VU University Medical Center, Amsterdam (Netherlands). Dept. of Nuclear Medicine and PET Research; VU University Medical Center, Amsterdam (Netherlands). Dept. of Otolaryngology/Head and Neck Surgery

    2012-07-01

    Fast progressing immuno-PET gives reasons to develop new potential medium-long and long-lived radioisotopes. One of the promising candidates is {sup 90}Nb. It has a half-life of 14.6 h, which allows visualizing and quantifying processes with medium and slow kinetics, such as tumor accumulation of antibodies and antibodies fragments or polymers and other nanoparticles. {sup 90}Nb exhibits a high positron branching of 53% and an optimal energy of {beta}{sup +} emission of E{sub mean} = 0.35 MeV only. Consequently, efficient radionuclide production routes and Nb{sup V} labeling techniques are required. {sup 90}Nb was produced by the {sup 90}Zr(p,n){sup 90}Nb nuclear reaction on natural zirconium targets. No-carrier-added (n.c.a.) {sup 90}Nb was separated from the zirconium target via a multi-step separation procedure including extraction steps and ion-exchange chromatography. Protein labeling was exemplified using the bifunctional chelator desferrioxamine attached to the monoclonal antibody rituximab. Desferrioxamine was coupled to rituximab via two different routes, by the use of N-succinyl-desferrioxamine (N-suc-Df) and by means of the bifunctional derivative p-isothiocyanatobenzyl-desferrioxamine B (Df-Bz-NCS), respectively. Following antibody modification, labeling with {sup 90}Nb was performed in HEPES buffer at pH 7 at room temperature. In vitro stability of the radiolabeled conjugates was tested in saline buffer at room temperature and in fetal calf serum (FCS) at 37 C. The selected production route led to a high yield of 145 {+-} 10 MBq/{mu}A h of {sup 90}Nb with high radioisotopic purity of > 97%. This yield may allow for large scale production of about 10 GBq {sup 90}Nb. The separation procedure resulted in 76-81% yield. The Zr/{sup 90}Nb decontamination factor reaches 10{sup 7}. Subsequent radiolabeling of the two different conjugates with {sup 90}Nb gave high yields; after one hour incubation at room temperature, more than 90% of {sup 90}Nb-Df-mAb was

  3. Human N-methyl D-aspartate receptor antibodies alter memory and behaviour in mice.

    Science.gov (United States)

    Planagumà, Jesús; Leypoldt, Frank; Mannara, Francesco; Gutiérrez-Cuesta, Javier; Martín-García, Elena; Aguilar, Esther; Titulaer, Maarten J; Petit-Pedrol, Mar; Jain, Ankit; Balice-Gordon, Rita; Lakadamyali, Melike; Graus, Francesc; Maldonado, Rafael; Dalmau, Josep

    2015-01-01

    Anti-N-methyl D-aspartate receptor (NMDAR) encephalitis is a severe neuropsychiatric disorder that associates with prominent memory and behavioural deficits. Patients' antibodies react with the N-terminal domain of the GluN1 (previously known as NR1) subunit of NMDAR causing in cultured neurons a selective and reversible internalization of cell-surface receptors. These effects and the frequent response to immunotherapy have suggested an antibody-mediated pathogenesis, but to date there is no animal model showing that patients' antibodies cause memory and behavioural deficits. To develop such a model, C57BL6/J mice underwent placement of ventricular catheters connected to osmotic pumps that delivered a continuous infusion of patients' or control cerebrospinal fluid (flow rate 0.25 µl/h, 14 days). During and after the infusion period standardized tests were applied, including tasks to assess memory (novel object recognition in open field and V-maze paradigms), anhedonic behaviours (sucrose preference test), depressive-like behaviours (tail suspension, forced swimming tests), anxiety (black and white, elevated plus maze tests), aggressiveness (resident-intruder test), and locomotor activity (horizontal and vertical). Animals sacrificed at Days 5, 13, 18, 26 and 46 were examined for brain-bound antibodies and the antibody effects on total and synaptic NMDAR clusters and protein concentration using confocal microscopy and immunoblot analysis. These experiments showed that animals infused with patients' cerebrospinal fluid, but not control cerebrospinal fluid, developed progressive memory deficits, and anhedonic and depressive-like behaviours, without affecting other behavioural or locomotor tasks. Memory deficits gradually worsened until Day 18 (4 days after the infusion stopped) and all symptoms resolved over the next week. Accompanying brain tissue studies showed progressive increase of brain-bound human antibodies, predominantly in the hippocampus (maximal on Days

  4. Isolation and characterization of cytotoxic effector cells and antibody producing cells from human intestine.

    Science.gov (United States)

    MacDermott, R P

    1985-01-01

    We have examined the ability of intestinal and peripheral blood mononuclear cells isolated from patients with inflammatory bowel disease to mediate killing against cell line targets in spontaneous, antibody-dependent, lectin-induced, and interferon-induced cell-mediated cytotoxicity assays, as well as responsiveness in the allogeneic mixed leukocyte reaction, and effector capabilities in cell-mediated lympholysis. IMC were poor mediators of spontaneous or antibody-dependent cellular cytotoxicity with cell line cells as targets (in comparison to normal PBMC, but were capable of killing antibody coated chicken red blood cells. Although IMC were capable of responding to allogeneic cell surface antigens in the mixed leukocyte reaction, they did not exhibit effector function in cell-mediated lympholysis. Mitogenic lectins induced cell-mediated cytotoxicity by isolated intestinal mononuclear cells from controls and patients. HFIF induces cytotoxicity by control but not inflammatory bowel disease intestinal cells. Pokeweed mitogen was the lectin which induced the greatest amount of killing against human cell line targets. We therefore speculate that exogenous agents, or endogenous factors released during viral infection, could play a role in inducing cell mediated cytotoxic damage to the intestine in inflammatory bowel disease patients. In addition, the functional differences between IMC and PBMC indicate that intestinal MNC may have unique cell capabilities which must be better understood prior to the delineation of immunopathologic events in solid organ tissues. We have also examined the secretion of IgA, IgM, and IgG by isolated human IMC, human bone marrow MNC from rib specimens, and PBMC from patients with CD, UC, SLE, or Henoch-Schoenlein purpura (HSP). Control IMC exhibited high spontaneous secretion of IgA, while intestinal MNC from UC and CD patients exhibited only modest increases in IgA secretion. PBMC from patients with CD, UC, SLE, or HSP exhibited markedly

  5. Produksi dan Karakterisasi Antibodi Monoklonal Anti-Cysticercus cellulosae (PRODUCTION AND CHRACTERIZATION OF MONOCLONAL