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Sample records for humanized anti-cd20 antibody

  1. Characterization of a Novel Humanized Anti-CD20 Antibody with Potent Anti-Tumor Activity against Non-Hodgkin's Lymphoma

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    Haifeng Zhang

    2013-09-01

    Full Text Available Background: Rituximab, a mouse Fab and human Fc chimeric antibody, has been widely used to treat Non-Hodgkin's lymphoma (NHL. However, only 48% of patients respond to the treatment and complete response rate is below 10%. Also, immunogenicity was reported in 17-20% patients receiving the treatment, making it unsuitable for long term diseases such as autoimmune disorders. It has been a hot research field to “humanize” rituximab toward improved efficacy and reduced immunogenicity. Methods: In this study, an advanced antibody humanization technology was applied to the sequence of the anti-CD20 antibody 2B8, its sequence of which was based on the original murine monoclonal antibody of rituximab in Roche. The complementarity-determining regions (CDRs of the humanized antibodies were further optimized through computer-aided molecular dock. Results: Five novel humanized anti-CD20 antibodies 1-5(1635, 1534, 3637, 1634 and 1536 were generated and their immunogenicity was significantly decreased when compared to rituximab. The novel humanized anti-CD20 antibodies 1-5 retained the binding activity of their murine counterpart, as demonstrated by the fluorescence-activated cell-sorting analysis (FACS. When compared to rituximab, the humanized antibodies still have the similar properties on both complement-dependent cytotoxicity (CDC and antibody-dependent cell-mediated cytotoxicity (ADCC. Furthermore, its anti-tumor efficacy in xenograft model is comparable to that of rituximab. Conclusion: The humanized anti-CD20 antibodies 1-5 have lower immunogenicity than rituximab. And at the same time, they still retain the anti-tumor effect both in vitro and vivo.

  2. Tetravalent anti-CD20/CD3 bispecific antibody for the treatment of B cell lymphoma

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    Lu, Chia-Yen; Chen, Gregory J.; Tai, Pei-Han; Yang, Yu-Chen [Institute of Biologics, Development Center for Biotechnology, New Taipei City, Taiwan (China); Hsu, Yu-Shen, E-mail: yshsu@advagene.com.tw [Laboratory of Biopharmaceutical Research, Advagene Biopharma, Taipei, Taiwan (China); Chang, Mingi, E-mail: mingi.chang@advagene.com.tw [Laboratory of Biopharmaceutical Research, Advagene Biopharma, Taipei, Taiwan (China); Hsu, Chuan-Lung, E-mail: fabio@dcb.org.tw [Institute of Biologics, Development Center for Biotechnology, New Taipei City, Taiwan (China)

    2016-05-13

    Bispecific antibodies (bsAbs) are second generation antibodies for therapeutic application in immunotherapy. One of the major strategies of the bsAb platform is the recruitment of immune effector T cells by incorporating an anti-CD3 domain. A bispecific T-cell engager (BiTE), with one end having an affinity for CD3 and the other end with affinity for CD19, has been approved in the US and Europe for the treatment of acute lymphoblastic leukemia. However, due to their small size and lack of Fc region, these single-chain variable fragment (scFv) bsAbs have short half-lives in vivo. Additionally, poor solubility, structural instability, and low production yields have also become major challenges in the bulk production process. To overcome these challenges, we have engineered a tetravalent bsAb with bivalent binding specificity for the CD20 and CD3 antigen in an immunoglobulin G (IgG) format. The fusion of the anti-CD3 scFvs to the CD20 antibody via a linker-hinge domain (LHD) results in improved antibody stabilization and properties. Here we demonstrate this antibody's highly efficient cancer cell elimination in a dose-dependent manner in a CD20-expressing B lymphoblastoid cell line in vitro. Our data suggest the potential clinical application of this bsAb for the treatment of CD20-expressing B cell malignancies. - Highlights: • A bispecific antibody (bsAb) can increase immunotherapeutic efficacy. • A tetravalent bsAb with binding specificity for the CD20 and CD3 antigens is proposed. • A linker-hinge domain (LHD) within the bsAb results in improved antibody properties.

  3. Evaluation of dry blood spot technique for quantification of an Anti-CD20 monoclonal antibody drug in human blood samples.

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    Lin, Yong-Qing; Zhang, Yilu; Li, Connie; Li, Louis; Zhang, Kelley; Li, Shawn

    2012-01-01

    To evaluate the dried blood spot (DBS) technique in ELISA quantification of larger biomolecular drugs, an anti-CD20 monoclonal antibody drug was used as an example. A method for the quantification of the anti-CD20 drug in human DBS was developed and validated. The drug standard and quality control samples prepared in fresh human blood were spotted on DBS cards and then extracted. A luminescent ELISA was used for quantification of the drug from DBS samples. The assay range of the anti-CD20 drug standards in DBS was 100-2500ng/mL. The intra-assay precision (%CV) ranged from 0.4% to 10.1%, and the accuracy (%Recovery) ranged from 77.9% to 113.9%. The inter assay precision (%CV) ranged from 5.9% to 17.4%, and the accuracy ranged from 81.5% to 110.5%. The DBS samples diluted 500 and 50-fold yielded recovery of 88.7% and 90.7%, respectively. The preparation of DBS in higher and lower hematocrit (53% and 35%) conditions did not affect the recovery of the drug. Furthermore, the storage stability of the anti-CD20 drug on DBS cards was tested at various conditions. It was found that the anti-CD20 drug was stable for one week in DBS stored at room temperature. However, it was determined that the stability was compro]mised in DBS stored at high humidity, high temperature (55°C), and exposed to direct daylight for a week, as well as for samples stored at room temperature and high humidity conditions for a month. Stability did not change significantly in samples that underwent 3 freeze/thaw cycles. Our results demonstrated a successful use of DBS technique in ELISA quantification of an anti-CD20 monoclonal antibody drug in human blood. The stability data provides information regarding sample storage and shipping for future clinical studies. It is, therefore, concluded that the DBS technique is applicable in the quantification of other large biomolecule drugs or biomarkers. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Development of new versions of anti-human CD34 monoclonal antibodies with potentially reduced immunogenicity

    International Nuclear Information System (INIS)

    Qian Weizhu; Wang Ling; Li Bohua; Wang Hao; Hou Sheng; Hong Xueyu; Zhang Dapeng; Guo Yajun

    2008-01-01

    Despite the widespread clinical use of CD34 antibodies for the purification of human hematopoietic stem/progenitor cells, all the current anti-human CD34 monoclonal antibodies (mAbs) are murine, which have the potential to elicit human antimouse antibody (HAMA) immune response. In the present study, we developed three new mouse anti-human CD34 mAbs which, respectively, belonged to class I, class II and class III CD34 epitope antibodies. In an attempt to reduce the immunogenicity of these three murine mAbs, their chimeric antibodies, which consisted of mouse antibody variable regions fused genetically to human antibody constant regions, were constructed and characterized. The anti-CD34 chimeric antibodies were shown to possess affinity and specificity similar to that of their respective parental murine antibodies. Due to the potentially better safety profiles, these chimeric antibodies might become alternatives to mouse anti-CD34 antibodies routinely used for clinical application

  5. Labeling an anti-CD20 monoclonal antibody with 90Y

    International Nuclear Information System (INIS)

    Perera Pintado, Alejandro; Leyva Montaña, René; Prats Capote, Anaís; Góngora Bravo, Magdiel; Alberti Ramírez, Alejandro; León, Mariela; Hernández González, Ignacio; Dorvignit, Denise

    2016-01-01

    Lymphomas are among the 10 leading causes of death, both in Cuba and in the world, with an increasing incidence in recent years. Follicular lymphoma low-grade (indolent) is one of the most common in the Western world, representing 1/3 of all non-Hodgkin lymphomas (NHL). More than 90% of patients present with disseminated disease at diagnosis and generally have a slow evolution and good response to conventional treatment; but radically changed its forecast to relapse, resistance to therapeutic and histologic transformation can occur. The monoclonal antibody therapy has been a promising therapeutic. In this respect CD20 antigen it has been considered one of the most attractive targets in the therapy of follicular B cell lymphoma This is expressed in more than 90% of cases, while not present in stem cells and lines progenitors. Despite the success of immunotherapy, the relapse rate is still considerable. In order to increase the cytotoxic potential of immunotherapy, marked with beta emitting radionuclides alpha particles or monoclonal antibodies are used today. Despite encouraging results in patients with non-Hodgkin lymphomas refractory to other treatments, the extremely high costs of these commercial radiopharmaceuticals have greatly limited its application, even in the first world. A sustainable alternative is the marking of other anti-CD20 monoclonal antibodies, so researchers from several countries have concentrated their efforts on rituximaby other similar antibodies labeled with therapeutic radionuclides, as a possible cost-effectively to more problem. Today in Cuba it has an electrolytic generator 90 Sr- 90 Y Isotope Center, which ensures the availability of the radionuclide. In addition, the chimeric MAb rituximab is applied as part of the therapy of NHL in its health system and, recently, the Center for Molecular Immunology has obtained a chimeric monoclonal anti-CD20 antibody biosimilar rituximab, which is in phase clinical trial; which opens prospects for

  6. Subcutaneous injections of low-dose veltuzumab (humanized anti-CD20 antibody) are safe and active in patients with indolent non-Hodgkin's lymphoma.

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    Negrea, George O; Elstrom, Rebecca; Allen, Steven L; Rai, Kanti R; Abbasi, Rashid M; Farber, Charles M; Teoh, Nick; Horne, Heather; Wegener, William A; Goldenberg, David M

    2011-04-01

    Subcutaneous injections of anti-CD20 antibodies may offer benefits to both patients and the healthcare system for treatment of B-cell malignancies. A pilot study was undertaken to evaluate the potential for subcutaneous dosing with 2(nd) generation anti-CD20 antibody veltuzumab in patients with CD20(+) indolent non-Hodgkin's lymphoma. Patients with previously untreated or relapsed disease received 4 doses of 80, 160, or 320 mg veltuzumab injected subcutaneously every two weeks. Responses were assessed by computed tomography scans, with other evaluations including adverse events, safety laboratories, B-cell blood levels, serum veltuzumab levels, and human anti-veltuzumab antibody (HAHA) titers. Seventeen patients (14 follicular lymphoma; 13 stage III or IV disease; 5 treatment-naive) completed treatment with only occasional, mild-moderate, transient injection reactions and no other safety issues. Subcutaneous veltuzumab demonstrated a slow release pattern over several days, achieving a mean Cmax of 19, 25 and 63 μg/mL at 80, 160, and 320 mg doses for a total of 4 administrations, respectively. Depletion of circulating B cells occurred after the first injection. The objective response rate (partial responses plus complete responses plus complete responses unconfirmed) was 47% (8/17) with a complete response/complete response unconfirmed rate of 24% (4/17); 4 of 8 objective responses continued for 60 weeks or more. All serum samples evaluated for human anti-veltuzumab antibody were negative. Subcutaneous injections of low-dose veltuzumab are convenient, well tolerated, and capable of achieving sustained serum levels, B-cell depletion, and durable objective responses in indolent non-Hodgkin's lymphoma. (Clinicaltrials.gov identifier: NCT00546793).

  7. Ibrutinib interferes with the cell-mediated anti-tumor activities of therapeutic CD20 antibodies: implications for combination therapy

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    Roit, Fabio Da; Engelberts, Patrick J.; Taylor, Ronald P.; Breij, Esther C.W.; Gritti, Giuseppe; Rambaldi, Alessandro; Introna, Martino; Parren, Paul W.H.I.; Beurskens, Frank J.; Golay, Josée

    2015-01-01

    The novel Bruton tyrosine kinase inhibitor ibrutinib and phosphatidyl-4-5-biphosphate 3-kinase-δ inhibitor idelalisib are promising drugs for the treatment of chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma, either alone or in combination with anti-CD20 antibodies. We investigated the possible positive or negative impact of these drugs on all known mechanisms of action of both type I and type II anti-CD20 antibodies. Pretreatment with ibrutinib for 1 hour did not increase direct cell death of cell lines or chronic lymphocytic leukemia samples mediated by anti-CD20 antibodies. Pre-treatment with ibrutinib did not inhibit complement activation or complement-mediated lysis. In contrast, ibrutinib strongly inhibited all cell-mediated mechanisms induced by anti-CD20 antibodies rituximab, ofatumumab or obinutuzumab, either in purified systems or whole blood assays. Activation of natural killer cells, and antibody-dependent cellular cytotoxicity by these cells, as well as phagocytosis by macrophages or neutrophils were inhibited by ibrutinib with a half maximal effective concentration of 0.3–3 μM. Analysis of anti-CD20 mediated activation of natural killer cells isolated from patients on continued oral ibrutinib treatment suggested that repeated drug dosing inhibits these cells in vivo. Finally we show that the phosphatidyl-4-5-biphosphate 3-kinase-δ inhibitor idelalisib similarly inhibited the immune cell-mediated mechanisms induced by anti-CD20 antibodies, although the effects of this drug at 10 μM were weaker than those observed with ibrutinib at the same concentration. We conclude that the design of combined treatment schedules of anti-CD20 antibodies with these kinase inhibitors should consider the multiple negative interactions between these two classes of drugs. PMID:25344523

  8. Ibrutinib interferes with the cell-mediated anti-tumor activities of therapeutic CD20 antibodies: implications for combination therapy

    DEFF Research Database (Denmark)

    Da Roit, F.; Engelberts, P. J.; Taylor, R. P.

    2015-01-01

    The novel Bruton tyrosine kinase inhibitor ibrutinib and phosphatidyl-4-5-biphosphate 3-kinase-delta inhibitor idelalisib are promising drugs for the treatment of chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma, either alone or in combination with anti-CD20 antibodies. We investigated...... the possible positive or negative impact of these drugs on all known mechanisms of action of both type I and type II anti-CD20 antibodies. Pretreatment with ibrutinib for 1 hour did not increase direct cell death of cell lines or chronic lymphocytic leukemia samples mediated by anti-CD20 antibodies. Pre......-treatment with ibrutinib did not inhibit complement activation or complement-mediated lysis. In contrast, ibrutinib strongly inhibited all cell-mediated mechanisms induced by anti-CD20 antibodies rituximab, ofatumumab or obinutuzumab, either in purified systems or whole blood assays. Activation of natural killer cells...

  9. Subcutaneous injections of low-dose veltuzumab (humanized anti-CD20 antibody) are safe and active in patients with indolent non-Hodgkin’s lymphoma

    Science.gov (United States)

    Negrea, George O.; Elstrom, Rebecca; Allen, Steven L.; Rai, Kanti R.; Abbasi, Rashid M.; Farber, Charles M.; Teoh, Nick; Horne, Heather; Wegener, William A.; Goldenberg, David M.

    2011-01-01

    Background Subcutaneous injections of anti-CD20 antibodies may offer benefits to both patients and the healthcare system for treatment of B-cell malignancies. Design and Methods A pilot study was undertaken to evaluate the potential for subcutaneous dosing with 2nd generation anti-CD20 antibody veltuzumab in patients with CD20+ indolent non-Hodgkin’s lymphoma. Patients with previously untreated or relapsed disease received 4 doses of 80, 160, or 320 mg veltuzumab injected subcutaneously every two weeks. Responses were assessed by computed tomography scans, with other evaluations including adverse events, safety laboratories, B-cell blood levels, serum veltuzumab levels, and human anti-veltuzumab antibody (HAHA) titers. Results Seventeen patients (14 follicular lymphoma; 13 stage III or IV disease; 5 treatment-naive) completed treatment with only occasional, mild-moderate, transient injection reactions and no other safety issues. Subcutaneous veltuzumab demonstrated a slow release pattern over several days, achieving a mean Cmax of 19, 25 and 63 μg/mL at 80, 160, and 320 mg doses for a total of 4 administrations, respectively. Depletion of circulating B cells occurred after the first injection. The objective response rate (partial responses plus complete responses plus complete responses unconfirmed) was 47% (8/17) with a complete response/complete response unconfirmed rate of 24% (4/17); 4 of 8 objective responses continued for 60 weeks or more. All serum samples evaluated for human anti-veltuzumab antibody were negative. Conclusions Subcutaneous injections of low-dose veltuzumab are convenient, well tolerated, and capable of achieving sustained serum levels, B-cell depletion, and durable objective responses in indolent non-Hodgkin’s lymphoma. (Clinicaltrials.gov identifier: NCT00546793) PMID:21173095

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

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

    2017-01-01

    CD47, a broadly expressed cell surface protein, inhibits cell phagocytosis via interaction with phagocyte-expressed SIRPα. A variety of hematological malignancies demonstrate elevated CD47 expression, suggesting that CD47 may mediate immune escape. We discovered three unique CD47-SIRPα blocking anti-CD47 monoclonal antibodies (mAbs) with low nano-molar affinity to human and cynomolgus monkey CD47, and no hemagglutination and platelet aggregation activity. To characterize the anti-cancer activity elicited by blocking CD47, the mAbs were cloned into effector function silent and competent Fc backbones. Effector function competent mAbs demonstrated potent activity in vitro and in vivo, while effector function silent mAbs demonstrated minimal activity, indicating that blocking CD47 only leads to a therapeutic effect in the presence of Fc effector function. A non-human primate study revealed that the effector function competent mAb IgG1 C47B222-(CHO) decreased red blood cells (RBC), hematocrit and hemoglobin by >40% at 1 mg/kg, whereas the effector function silent mAb IgG2σ C47B222-(CHO) had minimal impact on RBC indices at 1 and 10 mg/kg. Taken together, our findings suggest that targeting CD47 is an attractive therapeutic anti-cancer approach. However, the anti-cancer activity observed with anti-CD47 mAbs is Fc effector dependent as are the side effects observed on RBC indices. PMID:28234345

  11. Safety and efficacy of ofatumumab, a fully human monoclonal anti-CD20 antibody, in patients with relapsed or refractory B-cell chronic lymphocytic leukemia

    DEFF Research Database (Denmark)

    Coiffier, Bertrand; Lepretre, Stéphane; Pedersen, Lars Møller

    2008-01-01

    Safety and efficacy of the fully human anti-CD20 monoclonal antibody, ofatumumab, was analyzed in a multicenter dose-escalating study including 33 patients with relapsed or refractory chronic lymphocytic leukemia. Three cohorts of 3 (A), 3 (B), and 27 (C) patients received 4, once weekly, infusio...

  12. Interactions between ibrutinib and anti-CD20 antibodies; competing effects on the outcome of combination therapy

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    Skarzynski, Martin; Niemann, Carsten U; Lee, Yuh Shan; Martyr, Sabrina; Maric, Irina; Salem, Dalia; Stetler-Stevenson, Maryalice; Marti, Gerald E; Calvo, Katherine R; Yuan, Constance; Valdez, Janet; Soto, Susan; Farooqui, Mohammed Z.H.; Herman, Sarah E.M.; Wiestner, Adrian

    2015-01-01

    Purpose Clinical trials of ibrutinib combined with anti-CD20 monoclonal antibodies (mAbs) for chronic lymphocytic leukemia (CLL) report encouraging results. Paradoxically, in pre-clinical studies in vitro ibrutinib was reported to decrease CD20 expression and inhibits cellular effector mechanisms. We therefore set out to investigate effects of in vivo ibrutinib treatment that could explain this paradox. Experimental Design Patients received single agent ibrutinib (420mg daily) on an investigator-initiated phase 2 trial. Serial blood samples were collected pre-treatment and during treatment for ex vivo functional assays to examine the effects on CLL cell susceptibility to anti-CD20 mAbs. Results We demonstrate that CD20 expression on ibrutinib was rapidly and persistently down-regulated (median reduction 74%, day 28, Pibrutinib were less susceptible to anti-CD20 mAb-mediated complement-dependent cytotoxicity than pre-treatment cells (median reduction 75%, Pibrutinib, providing a likely mechanism for the preserved C3d opsonization. Additionally, ibrutinib significantly inhibited trogocytosis, a major contributor to antigen loss and tumor escape during mAb therapy. Conclusions Our data indicate that ibrutinib promotes both positive and negative interactions with anti-CD20 mAbs, suggesting that successfully harnessing maximal anti-tumor effects of such combinations requires further investigation. PMID:26283682

  13. Regional and systemic distribution of anti-tumor x anti-CD3 heteroaggregate antibodies and cultured human peripheral blood lymphocytes in a human colon cancer xenograft

    International Nuclear Information System (INIS)

    Nelson, H.; Ramsey, P.S.; Kerr, L.A.; McKean, D.J.; Donohue, J.H.

    1990-01-01

    Anti-tumor antibody (317G5) covalently coupled to an anti-CD3 antibody (OKT3) produces a heteroaggregate (HA) antibody that can target PBL to lyse tumor cells expressing the appropriate tumor Ag. The i.v. and i.p. distribution of radiolabeled HA antibody 317G5 x OKT3 and of radiolabeled cultured human PBL were studied in athymic nude mice bearing solid intraperitoneal tumor established from the human colon tumor line, LS174T. Mice were injected with 125I-labeled HA antibody, 125I-labeled anti-tumor mAb, or 111In-labeled PBL, and at designated timepoints tissues were harvested and measured for radioactivity. 125I-317G5 x OKT3 localized specifically to tumor sites. Tumor radioactivity levels (percent injected dose/gram) were lower with 125I-317G5 x OKT3 HA antibody than with 125I-317G5 anti-tumor mAb, but were similar to levels reported for other anti-tumor mAb. The major difference in radioactivity levels observed between i.v. and i.p. administration of 125I-317G5 x OKT3 was an increase in hepatic radioactivity after i.v. HA antibody administration. HA antibodies produced from F(ab')2 fragments, which exhibit decreased m. w. and decreased Fc receptor-mediated binding, demonstrated improved tumor:tissue ratios as compared to intact antibody HA. 125I-317G5 F(ab')2 x OKT3 F(ab')2 antibody levels were equivalent to intact HA antibody levels in tumor, but were lower than intact HA antibody levels in the blood, bowel, and liver. Tumor:bowel ratios (20:1 at 48 h) were highest when 317G5 F(ab')2 x OKT3 F(ab')2 was injected i.p. Autoradiography confirmed that anti-tumor x anti-CD3 HA antibodies localized specifically to intraperitoneal tumor; that i.p. administered HA antibodies penetrated tumor directly; and that i.v. administered HA antibodies distributed along tumor vasculature

  14. Enhanced efficacy of gemcitabine in combination with anti-CD20 monoclonal antibody against CD20+ non-Hodgkin's lymphoma cell lines in vitro and in scid mice

    Directory of Open Access Journals (Sweden)

    Jin Fang

    2005-08-01

    Full Text Available Abstract Background Despite exciting new targeted therapeutics against non-Hodgkin's lymphoma (NHL, chemotherapy remains a cornerstone of therapy. While purine nucleoside analogs have significant activity in low grade NHL, the pyrimidine nucleoside analog gemcitabine has been less extensively studied, but has important activity. Use of the anti-CD20 monoclonal antibody rituximab in combination with chemotherapy for B-NHL is becoming prevalent in clinical practice, but has not been extensively studied in pre-clinical models. Methods We have tested the activity of gemcitabine ± rituximab in vitro and in scid/human NHL xenograft models. We used two t(14;18+, CD20+ follicular B cell NHL cell lines, DoHH2 a transformed NHL line and WSU-FSCCL isolated from pleural fluid of a patient with indolent NHL. Results Gemcitabine is cytotoxic to DoHH2 and WSU-FSCCL cells in vitro, and the IC50 is 2–3 fold lower in the presence of rituximab. Apoptosis is also enhanced in the presence of rituximab. Clearance of NHL cells from ascites in scid mice is prolonged by the combination, as compared with either agent alone. Most importantly, survival of scid mice bearing human NHL cells is significantly prolonged by the combination of gemcitabine + rituximab. Conclusion Based on our pre-clinical data showing prolonged survival of mice bearing human lymphoma cell line xenografts after treatment with gemcitabine + anti-CD20 antibody, this combination, expected to have non-overlapping toxicity profiles, should be explored in clinical trials.

  15. Interactions between Ibrutinib and Anti-CD20 Antibodies: Competing Effects on the Outcome of Combination Therapy.

    Science.gov (United States)

    Skarzynski, Martin; Niemann, Carsten U; Lee, Yuh Shan; Martyr, Sabrina; Maric, Irina; Salem, Dalia; Stetler-Stevenson, Maryalice; Marti, Gerald E; Calvo, Katherine R; Yuan, Constance; Valdez, Janet; Soto, Susan; Farooqui, Mohammed Z H; Herman, Sarah E M; Wiestner, Adrian

    2016-01-01

    Clinical trials of ibrutinib combined with anti-CD20 monoclonal antibodies (mAb) for chronic lymphocytic leukemia (CLL) report encouraging results. Paradoxically, in preclinical studies, in vitro ibrutinib was reported to decrease CD20 expression and inhibit cellular effector mechanisms. We therefore set out to investigate effects of in vivo ibrutinib treatment that could explain this paradox. Patients received single-agent ibrutinib (420 mg daily) on an investigator-initiated phase II trial. Serial blood samples were collected pretreatment and during treatment for ex vivo functional assays to examine the effects on CLL cell susceptibility to anti-CD20 mAbs. We demonstrate that CD20 expression on ibrutinib was rapidly and persistently downregulated (median reduction 74%, day 28, P ibrutinib were less susceptible to anti-CD20 mAb-mediated complement-dependent cytotoxicity than pretreatment cells (median reduction 75%, P ibrutinib, providing a likely mechanism for the preserved C3d opsonization. In addition, ibrutinib significantly inhibited trogocytosis, a major contributor to antigen loss and tumor escape during mAb therapy. Our data indicate that ibrutinib promotes both positive and negative interactions with anti-CD20 mAbs, suggesting that successfully harnessing maximal antitumor effects of such combinations requires further investigation. ©2015 American Association for Cancer Research.

  16. Rituximab chimeric anti-CD20 monoclonal antibody treatment for adult refractory idiopathic thrombocytopenic purpura

    DEFF Research Database (Denmark)

    Braendstrup, Peter; Bjerrum, Ole W; Nielsen, Ove J

    2005-01-01

    . Recent studies have shown that rituximab, a chimeric anti-CD20 monoclonal antibody, is useful in the treatment of these patients, with overall response rates of about 50%. Most published reports have included a small number patients including case reports. The present study reports the results...

  17. Antigenic modulation limits the effector cell mechanisms employed by type I anti-CD20 monoclonal antibodies.

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    Tipton, Thomas R W; Roghanian, Ali; Oldham, Robert J; Carter, Matthew J; Cox, Kerry L; Mockridge, C Ian; French, Ruth R; Dahal, Lekh N; Duriez, Patrick J; Hargreaves, Philip G; Cragg, Mark S; Beers, Stephen A

    2015-03-19

    Following the success of rituximab, 2 other anti-CD20 monoclonal antibodies (mAbs), ofatumumab and obinutuzumab, have entered clinical use. Ofatumumab has enhanced capacity for complement-dependent cytotoxicity, whereas obinutuzumab, a type II mAb, lacks the ability to redistribute into lipid rafts and is glycoengineered for augmented antibody-dependent cellular cytotoxicity (ADCC). We previously showed that type I mAbs such as rituximab have a propensity to undergo enhanced antigenic modulation compared with type II. Here we assessed the key effector mechanisms affected, comparing type I and II antibodies of various isotypes in ADCC and antibody-dependent cellular-phagocytosis (ADCP) assays. Rituximab and ofatumumab depleted both normal and leukemic human CD20-expressing B cells in the mouse less effectively than glycoengineered and wild-type forms of obinutuzumab, particularly when human immunoglobulin G1 (hIgG1) mAbs were compared. In contrast to mouse IgG2a, hIgG1 mAbs were ineffective in ADCC assays with murine natural killer cells as effectors, whereas ADCP was equivalent for mouse IgG2a and hIgG1. However, rituximab's ability to elicit both ADCC and ADCP was reduced by antigenic modulation, whereas type II antibodies remained unaffected. These data demonstrate that ADCP and ADCC are impaired by antigenic modulation and that ADCP is the main effector function employed in vivo. © 2015 by The American Society of Hematology.

  18. Standardization of methodology to derivatization and radiolabeling of the anti-CD20 monoclonal antibody from bifunctional chelator DOTA-NHS-Ester

    International Nuclear Information System (INIS)

    Massicano, Adriana V.F.; Akanji, Akinkunmi G.; Santos, Josefina S.; Pujatti, Priscilla B.; Couto, Renata M.; Massicano, Felipe; Araujo, Elaine Bortoleti de

    2009-01-01

    Lymphomas are cancers of the lymphatic system, being the most common the non-Hodgkin lymphoma (NHL). The Radioimmunotherapy (RIT), that increase the cytotoxic effect of monoclonal antibodies (mAb), therefore labeling these Mab with different radioisotopes. RIT combines the specificity of the antibody and the toxicity of the radionuclides. The mAb anti-CD20 is used for treatment of relapse or refractory NHL. The labeling of anti- CD20 with 177 Lu, requires a bifunctional chelating agent that is designed to make a 'connect bridge' between the mAb and the radionuclide. The incorporation of the chelating group in mAb structure is called derivatization. The aim of this work is to study the derivatization of anti-CD20 antibody with DOTA-NHS-ester chelating group and labeling parameters to produce 177 Lu-DOTA-Anti CD20. Five milligrams of anti-CD20 were purified by dialysis against phosphate buffer pH 8.0 and derivatized with DOTA-NHS-ester in 1:250, 1:500 and 1:1000 molar ratios. The reaction was conducted for 1 hour in gently mixing at room temperature and remained under refrigeration for 48 hours. The reaction mixture was purified in gel column Sephadex G-50 ; the aliquots that presented greater protein concentration, were mixed and concentrated. The purified antibody conjugated was added to 111-185MBq (3-5mCi) of 177 LuCl3 diluted in 0.4 M acetate buffer pH 5.5. Radiochemical purity was less than 95% in all the molar ratios, indicating necessity of the purification after the labeling. The mAb derivatized showed stable when stored for to 1 month to 4 deg C and 4 days at -20 deg C. (author)

  19. A Preclinical Population Pharmacokinetic Model for Anti-CD20/CD3 T-Cell-Dependent Bispecific Antibodies.

    Science.gov (United States)

    Ferl, Gregory Z; Reyes, Arthur; Sun, Liping L; Cheu, Melissa; Oldendorp, Amy; Ramanujan, Saroja; Stefanich, Eric G

    2018-05-01

    CD20 is a cell-surface receptor expressed by healthy and neoplastic B cells and is a well-established target for biologics used to treat B-cell malignancies. Pharmacokinetic (PK) and pharmacodynamic (PD) data for the anti-CD20/CD3 T-cell-dependent bispecific antibody BTCT4465A were collected in transgenic mouse and nonhuman primate (NHP) studies. Pronounced nonlinearity in drug elimination was observed in the murine studies, and time-varying, nonlinear PK was observed in NHPs, where three empirical drug elimination terms were identified using a mixed-effects modeling approach: i) a constant nonsaturable linear clearance term (7 mL/day/kg); ii) a rapidly decaying time-varying, linear clearance term (t ½  = 1.6 h); and iii) a slowly decaying time-varying, nonlinear clearance term (t ½  = 4.8 days). The two time-varying drug elimination terms approximately track with time scales of B-cell depletion and T-cell migration/expansion within the central blood compartment. The mixed-effects NHP model was scaled to human and prospective clinical simulations were generated. © 2018 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  20. Radiolabeling and Preclinical Evaluation of 131I-anti-CD20 for Non-Hodgkin's Lymphomas Therapy

    International Nuclear Information System (INIS)

    Kullaprawittaya, Usa; Khongpetch, Pranom; Ngamprayad, Tippanan; Nuanchuen, Suphatphong

    2007-08-01

    Full text: In this study, a monoclonal anti-CD20 was developed for radioimmunotherapy of non-Hodgkin's B-cell lymphoma by reacting anti-CD20 with iodine-131 using iodogen procedure. It was found that radiochemical yield was > 95 % independently of incubation time and the antibody could be conjugated with iodine-131 up to 10 mCi/mg. The radiolabeled antibody exhibited excellent retention of immunoreactivity with radio incorporations >95% for 6 hr at 4 o C. In vitro stability tests showed minimal loss of iodine-131 from the conjugate in the presence of cysteine and in human serum at 37 o C. Biodistribution study in normal ICR mice showed higher uptake by the liver, kidney and intestines but lower thyroid uptake compared to 131 I -MIBG. Biodistribution studies confirmed the in vitro stability of 131 I -anti-CD20. In particular, excellent in vivo retention of iodine-131 was demonstrated by lower thyroid accumulation over 48 hr. A favorable biological distribution of 131 I -anti-CD20 suggests this radiopharmaceutical may be effectively used in the therapy of non-Hodgkin's lymphoma

  1. Combination of two anti-CD5 monoclonal antibodies synergistically induces complement-dependent cytotoxicity of chronic lymphocytic leukaemia cells.

    Science.gov (United States)

    Klitgaard, Josephine L; Koefoed, Klaus; Geisler, Christian; Gadeberg, Ole V; Frank, David A; Petersen, Jørgen; Jurlander, Jesper; Pedersen, Mikkel W

    2013-10-01

    The treatment of chronic lymphocytic leukaemia (CLL) has been improved by introduction of monoclonal antibodies (mAbs) that exert their effect through secondary effector mechanisms. CLL cells are characterized by expression of CD5 and CD23 along with CD19 and CD20, hence anti-CD5 Abs that engage secondary effector functions represent an attractive opportunity for CLL treatment. Here, a repertoire of mAbs against human CD5 was generated and tested for ability to induce complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) both as single mAbs and combinations of two mAbs against non-overlapping epitopes on human CD5. The results demonstrated that combinations of two mAbs significantly increased the level of CDC compared to the single mAbs, while no enhancement of ADCC was seen with anti-CD5 mAb combinations. High levels of CDC and ADCC correlated with low levels of Ab-induced CD5 internalization and degradation. Importantly, an anti-CD5 mAb combination enhanced CDC of CLL cells when combined with the anti-CD20 mAbs rituximab and ofatumumab as well as with the anti-CD52 mAb alemtuzumab. These results suggest that an anti-CD5 mAb combination inducing CDC and ADCC may be effective alone, in combination with mAbs against other targets or combined with chemotherapy for CLL and other CD5-expressing haematological or lymphoid malignancies. © 2013 John Wiley & Sons Ltd.

  2. Mass-Production and Characterization of Anti-CD20 Monoclonal Antibody in Peritoneum of Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Leili Aghebati

    2013-02-01

    Full Text Available Purpose: Monoclonal antibodies are important tools are used in basic research as well as, in diagnosis, imaging and treatment of immunodeficiency diseases, infections and cancers. The purpose of this study was to produce large scale of monoclonal antibody against CD20 in order to diagnostic application in leukemia and lymphomas disorders. Methods: Hybridoma cells that produce monoclonal antibody against human CD20 were administered into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. After twelve days, approximately 7 ml ascetic fluid was harvested from the peritoneum of each mouse. Evaluation of mAb titration was assessed by ELISA method. In the present study, we describe a protocol for large scale production of MAbs. Results: We prepared monoclonal antibodies (mAbs with high specificity and sensitivity against human CD20 by hybridoma method and characterized them by ELISA. The subclass of antibody was IgG2a and its light chain was kappa. Ascetic fluid was purified by Protein-A Sepharose affinity chromatography and the purified monoclonal antibody was conjugated with FITC and Immunofluorescence was done for confirming the specific binding. Conclusion: The conjugated monoclonal antibody could have application in diagnosis B-cell lymphomas, hairy cell leukemia, B-cell chronic lymphocytic leukemia, and melanoma cancer stem cells.

  3. Mass-Production and Characterization of Anti-CD20 Monoclonal Antibody in Peritoneum of Balb/c Mice

    Science.gov (United States)

    Sineh sepehr, Koushan; Baradaran, Behzad; Majidi, Jafar; Abdolalizadeh, Jalal; Aghebati, leili; Zare Shahneh, Fatemeh

    2013-01-01

    Purpose: Monoclonal antibodies are important tools are used in basic research as well as, in diagnosis, imaging and treatment of immunodeficiency diseases, infections and cancers. The purpose of this study was to produce large scale of monoclonal antibody against CD20 in order to diagnostic application in leukemia and lymphomas disorders. Methods: Hybridoma cells that produce monoclonal antibody against human CD20 were administered into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. After twelve days, approximately 7 ml ascetic fluid was harvested from the peritoneum of each mouse. Evaluation of mAb titration was assessed by ELISA method. In the present study, we describe a protocol for large scale production of MAbs. Results: We prepared monoclonal antibodies (mAbs) with high specificity and sensitivity against human CD20 by hybridoma method and characterized them by ELISA. The subclass of antibody was IgG2a and its light chain was kappa. Ascetic fluid was purified by Protein-A Sepharose affinity chromatography and the purified monoclonal antibody was conjugated with FITC and Immunofluorescence was done for confirming the specific binding. Conclusion: The conjugated monoclonal antibody could have application in diagnosis B-cell lymphomas, hairy cell leukemia, B-cell chronic lymphocytic leukemia, and melanoma cancer stem cells. PMID:24312821

  4. [{sup 177}Lu]DOTA-anti-CD20: Labeling and pre-clinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Audicio, Paola F., E-mail: paudicio@cin.edu.u [Departamento de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la Republica, Mataojo 2055, 11400 Montevideo (Uruguay); Castellano, Gustavo, E-mail: gcas@famaf.unc.edu.a [FaMAF, Universidad Nacional de Cordoba, Ciudad Universitaria, 5016 Cordoba (Argentina); Tassano, Marcos R.; Rezzano, Maria E.; Fernandez, Marcelo [Departamento de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la Republica, Mataojo 2055, 11400 Montevideo (Uruguay); Riva, Eloisa [Clinica Hematologica ' Prof. Dra. L. Diaz' , Hospital de Clinicas. Av. Italia. sn, Montevideo (Uruguay); Robles, Ana; Cabral, Pablo; Balter, Henia; Oliver, Patricia [Departamento de Radiofarmacia, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la Republica, Mataojo 2055, 11400 Montevideo (Uruguay)

    2011-07-15

    Anti-CD20 (Rituximab), a specific chimeric monoclonal antibody used in CD20-positive Non-Hodgkin's Lymphoma, was conjugated to a bifunctional quelate (DOTA) and radiolabeled with {sup 177}Lu through a simple method. [{sup 177}Lu]-DOTA-anti-CD20 was obtained with a radiochemical purity higher than 97%, and showed good chemical and biological stability, maintaining its biospecificity to CD20 antigens. Monte Carlo simulation showed high doses deposited on a spheroid tumor mass model. This method seems to be an appropriate alternative for the production of [{sup 177}Lu]-DOTA-anti-CD20 as therapeutic radiopharmaceutical.

  5. B cell-targeted therapy with anti-CD20 monoclonal antibody in a mouse model of Graves' hyperthyroidism.

    Science.gov (United States)

    Ueki, I; Abiru, N; Kobayashi, M; Nakahara, M; Ichikawa, T; Eguchi, K; Nagayama, Y

    2011-03-01

    Graves' disease is a B cell-mediated and T cell-dependent autoimmune disease of the thyroid which is characterized by overproduction of thyroid hormones and thyroid enlargement by agonistic anti-thyrotrophin receptor (TSHR) autoantibody. In addition to antibody secretion, B cells have recently been recognized to function as antigen-presenting/immune-modulatory cells. The present study was designed to evaluate the efficacy of B cell depletion by anti-mouse (m) CD20 monoclonal antibody (mAb) on Graves' hyperthyroidism in a mouse model involving repeated injection of adenovirus expressing TSHR A-subunit (Ad-TSHR289). We observe that a single injection of 250 µg/mouse anti-mCD20 mAb eliminated B cells efficiently from the periphery and spleen and to a lesser extent from the peritoneum for more than 3 weeks. B cell depletion before immunization suppressed an increase in serum immunoglobulin (Ig)G levels, TSHR-specific splenocyte secretion of interferon (IFN)-γ, anti-TSHR antibody production and development of hyperthyroidism. B cell depletion 2 weeks after the first immunization, a time-point at which T cells were primed but antibody production was not observed, was still effective at inhibiting antibody production and disease development without inhibiting splenocyte secretion of IFN-γ. By contrast, B cell depletion in hyperthyroid mice was therapeutically ineffective. Together, these data demonstrate that B cells are critical not only as antibody-producing cells but also as antigen-presenting/immune-modulatory cells in the early phase of the induction of experimental Graves' hyperthyroidism and, although therapeutically less effective, B cell depletion is highly efficient for preventing disease development. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.

  6. B cell-targeted therapy with anti-CD20 monoclonal antibody in a mouse model of Graves' hyperthyroidism

    Science.gov (United States)

    Ueki, I; Abiru, N; Kobayashi, M; Nakahara, M; Ichikawa, T; Eguchi, K; Nagayama, Y

    2011-01-01

    Graves' disease is a B cell-mediated and T cell-dependent autoimmune disease of the thyroid which is characterized by overproduction of thyroid hormones and thyroid enlargement by agonistic anti-thyrotrophin receptor (TSHR) autoantibody. In addition to antibody secretion, B cells have recently been recognized to function as antigen-presenting/immune-modulatory cells. The present study was designed to evaluate the efficacy of B cell depletion by anti-mouse (m) CD20 monoclonal antibody (mAb) on Graves' hyperthyroidism in a mouse model involving repeated injection of adenovirus expressing TSHR A-subunit (Ad-TSHR289). We observe that a single injection of 250 µg/mouse anti-mCD20 mAb eliminated B cells efficiently from the periphery and spleen and to a lesser extent from the peritoneum for more than 3 weeks. B cell depletion before immunization suppressed an increase in serum immunoglobulin (Ig)G levels, TSHR-specific splenocyte secretion of interferon (IFN)-γ, anti-TSHR antibody production and development of hyperthyroidism. B cell depletion 2 weeks after the first immunization, a time-point at which T cells were primed but antibody production was not observed, was still effective at inhibiting antibody production and disease development without inhibiting splenocyte secretion of IFN-γ. By contrast, B cell depletion in hyperthyroid mice was therapeutically ineffective. Together, these data demonstrate that B cells are critical not only as antibody-producing cells but also as antigen-presenting/immune-modulatory cells in the early phase of the induction of experimental Graves' hyperthyroidism and, although therapeutically less effective, B cell depletion is highly efficient for preventing disease development. PMID:21235532

  7. Biodistribution of Yttrium-90-Labeled Anti-CD45 Antibody in a Nonhuman Primate Model

    International Nuclear Information System (INIS)

    Nemecek, Eneida; Hamlin, Donald K.; Fisher, Darrell R.; Krohn, Kenneth A.; Pagel, John M.; Applebaum, F. R.; Press, Oliver W.; Matthews, Dana C.

    2005-01-01

    Radioimmunotherapy may improve the outcome of hematopoietic cell transplantation for hematologic malignancies by delivering targeted radiation to hematopoietic organs while relatively sparing nontarget organs. We evaluated the organ localization of yttrium-90-labeled anti-CD45 (90Y-anti-CD45) antibody in macaques, a model that had previously predicted iodine-131-labeled anti-CD-45 (131I-anti-CD45) antibody biodistribution in humans. Experimental Design: Twelve Macaca nemestrina primates received anti-CD45 antibody labeled with 1 to 2 mCi of 90Y followed by serial blood sampling and marrow and lymph node biopsies, and necropsy. The content of 90Y per gram of tissue was determined by liquid scintillation spectrometry. Time-activity curves were constructed using average isotope concentrations in each tissue at measured time points to yield the fractional residence time and estimate radiation absorbed doses for each organ per unit of administered activity. The biodistribution of 90Y-anti-CD45 antibody was then compared with that previously obtained with 131I-anti-CD45 antibody in macaques. Results: The spleen received 2,120, marrow 1,060, and lymph nodes 315 cGy/mCi of 90Y injected. The liver and lungs were the nontarget organs receiving the highest radiation absorbed doses (440 and 285 cGy/mCi, respectively). Ytrrium-90-labeled anti-CD45 antibody delivered 2.5- and 3.7-fold more radiation to marrow than to liver and lungs, respectively. The ratios previously observed with 131I-antiCD45 antibody were 2.5-and 2.2-fold more radiation to marrow than to liver and lungs, respectively. Conclusions: This study shows that 90Y-anti-CD45 antibody can deliver relatively selective radiation to hematopoietic tissues, with similar ratios of radiation delivered to target versus nontarget organs, as compared with the 131I immunoconjugate in the same animal model

  8. In ovo injection of anti-chicken CD25 monoclonal antibodies depletes CD4+CD25+ T cells in chickens.

    Science.gov (United States)

    Shanmugasundaram, Revathi; Selvaraj, Ramesh K

    2013-01-01

    The CD4(+)CD25(+) cells have T regulatory cell properties in chickens. This study investigated the effect of in ovo injection of anti-chicken CD25 monoclonal antibodies (0.5 mg/egg) on CD4(+)CD25(+) cell depletion and on amounts of interleukin-2 mRNA and interferon-γ mRNA in CD4(+)CD25(-) cells posthatch. Anti-chicken CD25 or PBS (control) was injected into 16-d-old embryos. Chicks hatched from eggs injected with anti-chicken CD25 antibodies had a lower CD4(+)CD25(+) cell percentage in the blood until 25 d posthatch. The anti-chicken CD25 antibody injection nearly depleted CD4(+)CD25(+) cells in the blood until 16 d posthatch. At 30 d posthatch, the CD4(+)CD25(+) cell percentage in the anti-CD25-antibody-injected group was comparable with the percentage in the control group. At 16 d posthatch, the anti-chicken CD25 antibody injection decreased CD4(+)CD25(+) cell percentages in the thymus, spleen, and cecal tonsils. Chickens hatched from anti-CD25-antibody-injected eggs had approximately 25% of CD4(+)CD25(+) cells in the cecal tonsils and thymus compared with those in the cecal tonsils and thymus of the control group. The CD4(+)CD25(-) cells from the spleen and cecal tonsils of chicks hatched from anti-chicken-CD25-injected eggs had higher amounts of interferon-γ and interleukin-2 mRNA than CD4(+)CD25(-) cells from the control group. It could be concluded that injecting anti-chicken CD25 antibodies in ovo at 16 d of incubation nearly depleted the CD4(+)CD25(+) cells until 25 d posthatch.

  9. 77 FR 9678 - Prospective Grant of Exclusive License: The Development of Human Anti-CD22 Monoclonal Antibodies...

    Science.gov (United States)

    2012-02-17

    .../patent applications for the technology family, to Sanomab, Ltd. The patent rights in these inventions... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Prospective Grant of Exclusive License: The Development of Human Anti-CD22 Monoclonal Antibodies for the Treatment of Human...

  10. Change of CD20 Expression in Diffuse Large B-Cell Lymphoma Treated with Rituximab, an Anti-CD20 Monoclonal Antibody: A Study of the Osaka Lymphoma Study Group

    Directory of Open Access Journals (Sweden)

    Naoki Wada

    2009-10-01

    Full Text Available Change of CD20 expression was examined in cases of diffuse large B-cell lymphoma (DLBCL. CD20 expression after treatment with anti-CD20 antibody (rituximab, Rx for DLBCL was examined in 23 cases who received serial biopsy by immunohistochemistry (IHC and flow cytometry (FCM. CD20– by IHC and/or FCM was defined as CD20–. Four cases were CD20– at initial biopsy but became CD20+ after chemotherapy with Rx (CH-R (group A. Recurrent tumors in three group A cases became resistant to CH-R. Initial and recurrent tumors were CD20+ before and after CH-R in 17 cases (group B. Tumors before CH-R were CD20– in two cases (group C and continued to be CD20– in one and turned CD20+ in the other with survival time after the relapse of 8 and 23 months, respectively. Evaluation of CD20 expression with immunohistochemical and flow cytometric methods is used for the prediction of responsiveness of relapsed DLBCL for CH-R.

  11. The biological characteristics of anti-CD71 mouse/human chimeric antibody

    International Nuclear Information System (INIS)

    Wang Shuo; Jiang Lin; Lei Ping; Zhu Huifen; Shen Guanxin; Cui Wuren; Wang Yanggong

    2002-01-01

    Objective: To study the biological characteristics of an anti-CD71 mouse/human chimeric antibody (D2C). Methods: Analysis of the chimeric Ab production in culture supernatant was made by the standard concentration curve method with ELISA. The antibody was purified by DEAE-Sephredax-A50 ion-exchange chromatography and was confirmed by SDS-PAGE. The competition inhibition studies for binding to the same epitope on CD71 were performed between the chimeric Ab(D2C) in the culture supernatant was about 0.5-5 μg/ml in 5-day cultures when seeded at 1 x 10 5 cells/5ml compared with 12.5-25 μg/ml in the supernatant from their parental monoclonal Ab(7579). The purified chimeric Ab(D2C) from mouse ascetics was 1-2 mg/ml. The SDS-PAGE analysis of purified chimeric Ab(D2C) with discontinuous system confirmed two protein bands of 55 kDa and 25 kDa. It was clear that both chimeric Ab(D2C) and murine monoclonal Ab (7579) compete effectively to join the same epitope of CD71 each other. The chimeric antibody's affinity constant (Ka), quantitated by Scatchard analysis, is about 9.34-9.62 x 10 9 L/mol. Conclusion: The chimeric Ab(D2C) produced from the transfectomas is stable. The binding capacity of the chimeric Ab(D2C) to the antigen (CD71) was retained

  12. Macrophage and NK-mediated killing of precursor-B acute lymphoblastic leukemia cells targeted with a-fucosylated anti-CD19 humanized antibodies.

    Science.gov (United States)

    Matlawska-Wasowska, K; Ward, E; Stevens, S; Wang, Y; Herbst, R; Winter, S S; Wilson, B S

    2013-06-01

    This work reports the tumoricidal effects of a novel investigational humanized anti-CD19 monoclonal antibody (Medi-551). An a-fucosylated antibody with increased affinity for human FcγRIIIA, Medi-551 is shown to mediate both antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Medi-551/CD19 complexes internalize slowly (>5 h) and thus remain accessible to effector cells for prolonged periods. We evaluated in vitro ADCC and ADCP activities of primary human natural killer (NK) cells and macrophages against precursor-B (pre-B) acute lymphoblastic leukemia (ALL) cell lines and pediatric patient blasts. Fluorescent imaging studies document immunological synapses formed between anti-CD19-bound target leukemia cells and effector cells and capture the kinetics of both NK-mediated killing and macrophage phagocytosis. Genetic polymorphisms in FcγRIIIA-158F/V modulate in vitro activities of effector cells, with FcγRIIIA-158V homozygotes or heterozygotes showing the strongest activity. Medi-551 treatment of severe combined immunodeficiency (SCID) mice engrafted with human pre-B cells led to prolonged animal survival and markedly reduced disease burden in blood, liver and bone marrow. These data show that anti-CD19 antibodies effectively recruit immune cells to pre-B ALL cells and support a move forward to early phase trials in this disease.

  13. Ofatumumab, a human anti-CD20 monoclonal antibody, for treatment of rheumatoid arthritis with an inadequate response to one or more disease-modifying antirheumatic drugs: results of a randomized, double-blind, placebo-controlled, phase I/II study

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Baslund, Bo; Rigby, William

    2010-01-01

    To investigate the safety and efficacy of ofatumumab, a novel human anti-CD20 monoclonal antibody (mAb), in patients with active rheumatoid arthritis (RA) whose disease did not respond to > or = 1 disease-modifying antirheumatic drug....

  14. Preparation of the radiopharmaceutical {sup 131}I-Anti-CD20 for the treatment of lymphomas; Preparacion del radiofarmaco {sup 131}I-Anti-CD20 para el tratamiento de linfomas

    Energy Technology Data Exchange (ETDEWEB)

    Pantoja H, I E

    2004-07-01

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with {sup 131} I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The {sup 131} I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical {sup 131} I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving CD20

  15. Cloning and expression of canine CD25 for validation of an anti-human CD25 antibody to compare T regulatory lymphocytes in healthy dogs and dogs with osteosarcoma.

    Science.gov (United States)

    Rissetto, K C; Rindt, H; Selting, K A; Villamil, J A; Henry, C J; Reinero, C R

    2010-05-15

    T regulatory cells (Tregs) are a unique subset of T helper cells that serve to modify/inhibit effector cells of the immune system and thus are essential to prevent autoimmunity. Overzealous Treg activity may contribute to impaired immune responses to cancer. Tregs can be phenotypically identified by proteins expressed on the cell surface (CD4 and CD25) and inside the cell (forkhead box3 (FoxP3)), although in dogs, no anti-canine CD25 antibody exists. We hypothesized that a mouse anti-human CD25 antibody definitively recognizes the canine protein and can be used to identify Tregs in dogs. We describe cloning and transfection of the canine CD25 gene into human HeLa cells with subsequent expression of the canine protein on the cell surface detected using an anti-human CD25 antibody in a flow cytometric assay. Validation of this antibody was used to identify CD4+CD25+FoxP3+ Tregs in 39 healthy dogs and 16 dogs with osteosarcoma (OSA). Results were expressed in five different ways and showed significantly fewer %CD4+CD25+ T lymphocytes expressing FoxP3 in blood of older dogs (>/=7 years) compared with the other two age groups (<2 and 2-6 years) (p<0.001) and fewer %CD4+CD25+FoxP3+ Tregs in the tumor draining lymph nodes of OSA patients compared to the unrelated lymph node (p=0.049). However, there was no significant difference in % Tregs in the peripheral blood or lymph nodes between the control dogs and those with OSA. While the CD25 antibody can be successfully used in a flow cytometric assay to identify Tregs, this study does not support clinical utility of phenotypic recognition of Tregs in dogs with OSA. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Sensitive Detection of the Natural Killer Cell-Mediated Cytotoxicity of Anti-CD20 Antibodies and Its Impairment by B-Cell Receptor Pathway Inhibitors

    Directory of Open Access Journals (Sweden)

    Floyd Hassenrück

    2018-01-01

    Full Text Available The antibody-dependent cell-mediated cytotoxicity (ADCC of the anti-CD20 monoclonal antibodies (mAbs rituximab and obinutuzumab against the cell line Raji and isolated CLL cells and its potential impairment by kinase inhibitors (KI was determined via lactate dehydrogenase release or calcein retention, respectively, using genetically modified NK92 cells expressing CD16-176V as effector cells. Compared to peripheral blood mononuclear cells, recombinant effector cell lines showed substantial alloreactivity-related cytotoxicity without addition of mAbs but afforded determination of ADCC with reduced interassay variability. The cytotoxicity owing to alloreactivity was less susceptible to interference by KI than the ADCC of anti-CD20 mAbs, which was markedly diminished by ibrutinib, but not by idelalisib. Compared to rituximab, the ADCC of obinutuzumab against primary CLL cells showed approximately 30% higher efficacy and less interference with KI. Irreversible BTK inhibitors at a clinically relevant concentration of 1 μM only weakly impaired the ADCC of anti-CD20 mAbs, with less influence in combinations with obinutuzumab than with rituximab and by acalabrutinib than by ibrutinib or tirabrutinib. In summary, NK cell line-based assays permitted the sensitive detection of ADCC of therapeutic anti-CD20 mAbs against CLL cells and of the interference of KI with this important killing mechanism.

  17. The study of labeling with Iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Akanji, Akinkunmi Ganiyu

    2006-01-01

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal antibody anti-CD20 (Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, stability in vivo, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was observed when antibody mass was varied. After purification, the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid was combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the literature. Biological distribution in

  18. Radiolabeling of anti-CD20 with Re0-188: liquid kit

    International Nuclear Information System (INIS)

    Dias, Carla Roberta; Osso Junior, Joao Alberto

    2007-01-01

    Radioimmunotherapy uses the targeting features of monoclonal antibody to deliver radiation from an attached radionuclide. The radionuclide 188 Re is currently produced from the father nuclide 188 W through a transportable generator system. Because of its easy availability and suitable nuclear properties (E βMAX =2.1 MeV, t 1/2 =16.9 h, E γ =155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agents and could be conveniently utilized for imaging and dosimetric purposes. The objective of this work is the optimization of radiolabeling of anti-CD20 with 188 Re using a liquid formulation. Anti-CD20 was reduced by incubation with 2-ME and purified over a PD-10 column. The number of resulting free SH was assayed with Ellman's reagent. Optimization of radiolabeling was achieved by varying parameters: antibody mass, reducing agent, reaction time and 188 Re volume in the liquid kit. Radiochemical purity of 188 Re-anti-CD20 was evaluated. An average of 12 SH groups per mol in the reductions was found. The best labeling efficiency (> 93%) was achieved in the following conditions: 1 mg anti-CD20; 82.8 mg sodium tartrate; 1 mg SnCl 2 ; 0.25 mg gentisic acid, 1 mL 188 Re and reaction time of 1 hour at room temperature. (author)

  19. Induction of CD4 suppressor T cells with anti-Leu-8 antibody

    International Nuclear Information System (INIS)

    Kanof, M.E.; Strober, W.; James, S.P.

    1987-01-01

    To characterize the conditions under which CD4 T cells suppress polyclonal immunoglobulin synthesis, we investigated the capacity of CD4 T cells that coexpress the surface antigen recognized by the monoclonal antibody anti-Leu-8 to mediate suppression. In an in vitro system devoid of CD8 T cells, CD4, Leu-8+ T cells suppressed pokeweed mitogen-induced immunoglobulin synthesis. Similarly, suppressor function was induced in unfractionated CD4 T cell populations after incubation with anti-Leu-8 antibody under cross-linking conditions. This induction of suppressor function by anti-Leu-8 antibody was not due to expansion of the CD4, Leu-8+ T cell population because CD4 T cells did not proliferate in response to anti-Leu-8 antibody. However, CD4, Leu-8+ T cell-mediated suppression was radiosensitive. Finally, CD4, Leu-8+ T cells do not inhibit immunoglobulin synthesis when T cell lymphokines were used in place of helper CD4 T cells (CD4, Leu-8- T cells), suggesting that CD4 T cell-mediated suppression occurs at the T cell level. We conclude that CD4 T cells can be induced to suppress immunoglobulin synthesis by modulation of the membrane antigen recognized by anti-Leu-8 antibody

  20. The study of labeling with iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Akanji, Akinkunmi Ganiyu

    2006-01-01

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal anti-CD20 (ex., Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was varied. After purification the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the

  1. Effects of in vivo injection of anti-chicken CD25 monoclonal antibody on regulatory T cell depletion and CD4+CD25- T cell properties in chickens.

    Science.gov (United States)

    Shanmugasundaram, Revathi; Selvaraj, Ramesh K

    2012-03-01

    Regulatory T cells (Tregs) are defined as CD4(+)CD25(+) cells in chickens. This study examined the effects of an anti-chicken CD25 monoclonal antibody injection (0.5 mg/bird) on in vivo depletion of Tregs and the properties of CD4(+)CD25(-) cells in Treg-depleted birds. The CD4(+)CD25(+) cell percentage in the blood was lower at 8 d post injection than at 0 d. Anti-CD25-mediated CD4(+)CD25(+) cell depletion in blood was maximum at 12 d post injection. The anti-CD25 antibody injection depleted CD4(+)CD25(+) cells in the spleen and cecal tonsils, but not in the thymus, at 12 d post antibody injection. CD4(+)CD25(-) cells from the spleen and cecal tonsils of birds injected with the anti-chicken CD25 antibody had higher proliferation and higher IL-2 and IFNγ mRNA amounts than the controls at 12 d post injection. At 20 d post injection, CD4(+)CD25(+) cell percentages in the blood, spleen and thymus were comparable to that of the 0 d post injection. It could be concluded that anti-chicken CD25 injection temporarily depleted Treg population and increased and IL-2 and IFNγ mRNA amounts in CD4(+)CD25(-) cells at 12d post injection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Preparation of the radiopharmaceutical {sup 131}I-Anti-CD20 for the treatment of lymphomas; Preparacion del radiofarmaco {sup 131}I-Anti-CD20 para el tratamiento de linfomas

    Energy Technology Data Exchange (ETDEWEB)

    Pantoja H, I.E

    2004-07-01

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with {sup 131} I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The {sup 131} I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical {sup 131} I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving

  3. Radiolabeling of anti-CD20 with Re0-188: liquid kit

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Carla Roberta; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: carlarobertab@yahoo.com.br; jaosso@ipen.br

    2007-07-01

    Radioimmunotherapy uses the targeting features of monoclonal antibody to deliver radiation from an attached radionuclide. The radionuclide {sup 188}Re is currently produced from the father nuclide {sup 188}W through a transportable generator system. Because of its easy availability and suitable nuclear properties (E{sub {beta}}{sub MAX} =2.1 MeV, t{sub 1/2}=16.9 h, E{sub {gamma}}=155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agents and could be conveniently utilized for imaging and dosimetric purposes. The objective of this work is the optimization of radiolabeling of anti-CD20 with {sup 188}Re using a liquid formulation. Anti-CD20 was reduced by incubation with 2-ME and purified over a PD-10 column. The number of resulting free SH was assayed with Ellman's reagent. Optimization of radiolabeling was achieved by varying parameters: antibody mass, reducing agent, reaction time and {sup 188}Re volume in the liquid kit. Radiochemical purity of {sup 188}Re-anti-CD20 was evaluated. An average of 12 SH groups per mol in the reductions was found. The best labeling efficiency (> 93%) was achieved in the following conditions: 1 mg anti-CD20; 82.8 mg sodium tartrate; 1 mg SnCl{sub 2}; 0.25 mg gentisic acid, 1 mL {sup 188}Re and reaction time of 1 hour at room temperature. (author)

  4. Preparation of the radiopharmaceutical 131I-Anti-CD20 for the treatment of lymphomas

    International Nuclear Information System (INIS)

    Pantoja H, I.E.

    2004-01-01

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with 131 I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The 131 I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical 131 I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving CD20 highly expressed in

  5. First clinical use of ofatumumab, a novel fully human anti-CD20 monoclonal antibody in relapsed or refractory follicular lymphoma

    DEFF Research Database (Denmark)

    Hagenbeek, Anton; Gadeberg, Ole Vestergaard; Johnson, Peter

    2008-01-01

    Ofatumumab is a unique monoclonal antibody that targets a distinct small loop epitope on the CD20 molecule. Preclinical data show that ofatumumab is active against B-cell lymphoma/chronic lymphocytic leukemia cells with low CD20-antigen density and high expression of complement inhibitory molecules...

  6. In vitro characterization of 177Lu-radiolabelled chimeric anti-CD20 monoclonal antibody and a preliminary dosimetry study

    International Nuclear Information System (INIS)

    Forrer, Flavio; Mueller-Brand, Jan; Chen, Jianhua; Fani, Melpomeni; Powell, Pia; Maecke, Helmut R.; Lohri, Andreas; Moldenhauer, Gerhard

    2009-01-01

    131 I- and 90 Y-labelled anti-CD20 antibodies have been shown to be effective in the treatment of low-grade, B-cell non-Hodgkin's lymphoma (NHL). However, the most appropriate radionuclide in terms of high efficiency and low toxicity has not yet been established. In this study we evaluated an immunoconjugate formed by the anti-CD20 antibody rituximab and the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). DOTA-rituximab was prepared as a kit formulation and can be labelled in a short time ( 177 Lu or 90 Y. Immunoconjugates with different numbers of DOTA molecules per rituximab were prepared using p-SCN-Bz-DOTA. In vitro immunoreactivity and stability were tested and preliminary dosimetric results were acquired in two patients. The immunological binding properties of DOTA-rituximab to the CD20 antigen were found to be retained after conjugation with up to four chelators. The labelled product was stable against a 10 5 times excess of diethylenetriaminepentaacetic acid (DTPA, 37 C, 7 days). Two patients with relapsed NHL were treated with 740 MBq/m 2 body surface 177 Lu-DOTA-rituximab. Scintigraphic images showed specific uptake at tumour sites and acceptable dosimetric results. The mean whole-body dose was found to be 314 mGy. The administration of 177 Lu-DOTA-rituximab was tolerated well. Our results show that DOTA-rituximab (4:1) can be labelled with 177 Lu with sufficient stability while the immunoconjugate retains its immunoreactivity. 177 Lu-DOTA-rituximab is an interesting, well-tolerated radiolabelled antibody with clinical activity in a low dose range, and provides an approach to the efficient treatment with few side effects for patients with relapsed NHL. (orig.)

  7. The different clinical effects of anti-BLyS, anti-APRIL and anti-CD20 antibodies point at a critical pathogenic role of γ-herpesvirus infected B cells in the marmoset EAE model.

    Science.gov (United States)

    Anwar Jagessar, S; Fagrouch, Zahra; Heijmans, Nicole; Bauer, Jan; Laman, Jon D; Oh, Luke; Migone, Thi; Verschoor, Ernst J; 't Hart, Bert A

    2013-06-01

    The robust and rapid clinical effect of depleting anti-CD20 monoclonal antibodies (mAb) in multiple sclerosis (MS) demonstrates a critical pathogenic contribution of B cells. The clinical effect of anti-CD20 mAb has been replicated in a relevant preclinical MS model, experimental autoimmune encephalomyelitis (EAE) in marmoset monkeys (Callithrix jacchus). By contrast, treatment with mAbs against two essential cytokines in B cell activation growth and survival, i.e. BlyS/BAFF and APRIL, was only partially effective. All three mAbs induced depletion of CD20+ B cells from the circulation, albeit with different kinetics and based on distinct mechanisms of action. In the current study we analyzed whether the different clinical effect of anti-CD20 mAb or the anti-BLyS and anti-APRIL mAbs is due to different depletion of B cells infected with the EBV of marmosets, CalHV3. Employing a novel PCR-based assay, half of the colony of group-housed marmosets was tested positive for CalHV3 DNA in secondary lymphoid organs. The same prevalence was observed in placebo-treated monkeys. In marmosets treated with anti-CD20 mAb the load of CalHV3 DNA in lymphoid organs was substantially reduced, while this was not observed in the monkeys treated with anti-BLyS or anti-APRIL mAbs. To examine the pathogenic role of virus-transformed B cells, we infused EBV-transformed B lymphoblastic cell (BLC) lines presenting the immunodominant MOG34-56 peptide. We observed in the recipients of MOG34-56 pulsed BLC, but not in their fraternal siblings infused with non-pulsed BLC, activation of anti-MOG34-56 T cells and meningeal inflammation. Collectively, the data show that among CD20+ B cells, the herpesvirus-transformed subset has a particularly important pathogenic role in the marmoset EAE model.

  8. In vitro characterization of {sup 177}Lu-radiolabelled chimeric anti-CD20 monoclonal antibody and a preliminary dosimetry study

    Energy Technology Data Exchange (ETDEWEB)

    Forrer, Flavio; Mueller-Brand, Jan [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Chen, Jianhua; Fani, Melpomeni; Powell, Pia; Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Lohri, Andreas [Basel University Medical Clinic, Liestal (Switzerland); Moldenhauer, Gerhard [German Cancer Research Center, Division of Molecular Immunology, Heidelberg (Germany)

    2009-09-15

    {sup 131}I- and {sup 90}Y-labelled anti-CD20 antibodies have been shown to be effective in the treatment of low-grade, B-cell non-Hodgkin's lymphoma (NHL). However, the most appropriate radionuclide in terms of high efficiency and low toxicity has not yet been established. In this study we evaluated an immunoconjugate formed by the anti-CD20 antibody rituximab and the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). DOTA-rituximab was prepared as a kit formulation and can be labelled in a short time (<20 min) with either {sup 177}Lu or {sup 90}Y. Immunoconjugates with different numbers of DOTA molecules per rituximab were prepared using p-SCN-Bz-DOTA. In vitro immunoreactivity and stability were tested and preliminary dosimetric results were acquired in two patients. The immunological binding properties of DOTA-rituximab to the CD20 antigen were found to be retained after conjugation with up to four chelators. The labelled product was stable against a 10{sup 5} times excess of diethylenetriaminepentaacetic acid (DTPA, 37 C, 7 days). Two patients with relapsed NHL were treated with 740 MBq/m{sup 2} body surface {sup 177}Lu-DOTA-rituximab. Scintigraphic images showed specific uptake at tumour sites and acceptable dosimetric results. The mean whole-body dose was found to be 314 mGy. The administration of {sup 177}Lu-DOTA-rituximab was tolerated well. Our results show that DOTA-rituximab (4:1) can be labelled with {sup 177}Lu with sufficient stability while the immunoconjugate retains its immunoreactivity. {sup 177}Lu-DOTA-rituximab is an interesting, well-tolerated radiolabelled antibody with clinical activity in a low dose range, and provides an approach to the efficient treatment with few side effects for patients with relapsed NHL. (orig.)

  9. Compartmental and dosimetric studies of anti-CD20 labelled with {sup 188}Re; Estudo compartimental e dosimetrico do Anti-CD20 marcado com {sup 188}Re

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, Graciela Barrio

    2016-10-01

    The radioimmunotherapy (RIT) uses MAbs conjugated to radionuclides α or β{sup -} emitters, both for therapy. Your treatment is based on the irradiation and tumor destruction, preserving the normal organs as the excess radiation. Radionuclides β{sup -} emitters as {sup 131}I, {sup 90}Y, {sup 188}Re {sup 177}Lu and are useful for the development of therapeutic radiopharmaceuticals and, when coupled with MAb and Anti-CD20 it is important mainly for the treatment of non-Hodgkin's lymphomas (NHL). {sup 188}Re (E{sub β} = 2.12 MeV; E{sub γ} = 155 keV; t1/2 = 16.9 h) is an attractive radionuclide for RIT. However, {sup 188}Re can be obtained from a radionuclide generator of {sup 188}W/{sup 188}Re, commercially available, making it convenient for use in research and for clinical routine. The CR of IPEN has a project aimed at the production of radiopharmaceutical {sup 188}Re-Anti-CD20, where the radionuclide can be obtained from a generator system {sup 188}W/{sup 188}Re. With this proposed a study to assess the efficiency of this labeling technique for treatment in accordance compartmental and dosimetry. The objective of this study was to compare the marking of anti-CD20 MAb with {sup 188}Re with the marking of the antibody with {sup 90}Y, {sup 131}I, {sup 177}Lu and {sup 99m}Tc (for their similar chemical characteristics) and {sup 211}At, {sup 213}Bi, {sup 223}Ra and {sup 225}Ac); through the study of labeling techniques reported in literature, the proposal of a compartmental model to evaluate its pharmacokinetic and dosimetric studies, high interest for therapy. The result of the study shows a favorable kinetics for {sup 188}Re, by their physical and chemical characteristics compared to the other evaluated radionuclides. The compartment proposed study describes the metabolism of {sup 188}Reanti- CD20 through a compartment mammillary model, which by their pharmacokinetic analysis, performed compared to products emitters β{sup -131}I-labeled anti CD20, {sup 177

  10. A phase I study of PRO131921, a novel anti-CD20 monoclonal antibody in patients with relapsed/refractory CD20+ indolent NHL: correlation between clinical responses and AUC pharmacokinetics.

    Science.gov (United States)

    Casulo, Carla; Vose, Julie M; Ho, William Y; Kahl, Brad; Brunvand, Mark; Goy, Andre; Kasamon, Yvette; Cheson, Bruce; Friedberg, Jonathan W

    2014-09-01

    PRO131921 is a third-generation, humanized anti-CD20 monoclonal antibody with increased antibody-dependent cytotoxicity and complement-dependent cytotoxicity compared to rituximab. In this phase I study, PRO131921 was administered as a single agent to patients with CD20+, relapsed or refractory, indolent non-Hodgkin lymphoma (NHL) who had been treated with a prior rituximab-containing regimen. The primary aim of this study was safety and tolerability of PRO131921. The secondary aim of the study, and focus of this report, was to determine the pharmacokinetics (PK) profile of PRO131921 and establish a correlation between drug exposure and clinical efficacy. Patients were treated with PRO131921 by intravenous infusion weekly for 4 weeks and the dose was escalated based on safety in a 3+3 design. Twenty-four patients were treated with PRO131921 at doses from 25mg/m(2) to 800 mg/m(2). Analysis of PK data demonstrated a correlation between higher normalized drug exposure (normalized AUC) and tumor shrinkage (p = .0035). Also, normalized AUC levels were higher among responders and subjects displaying tumor shrinkage versus subjects progressing or showing no regression (p = 0.030). In conclusion, PRO131921 demonstrated clinical activity in rituximab-relapsed and refractory indolent NHL patients. The observation that higher normalized AUC may be associated with improved clinical responses has potential implications in future trials of monoclonal antibody-based therapies, and emphasizes the importance of early PK studies to optimize antibody efficacy. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Compartmental and dosimetric studies of anti-CD20 labelled with 188Re

    International Nuclear Information System (INIS)

    Kuramoto, Graciela Barrio

    2016-01-01

    The radioimmunotherapy (RIT) uses MAbs conjugated to radionuclides α or β - emitters, both for therapy. Your treatment is based on the irradiation and tumor destruction, preserving the normal organs as the excess radiation. Radionuclides β - emitters as 131 I, 90 Y, 188 Re 177 Lu and are useful for the development of therapeutic radiopharmaceuticals and, when coupled with MAb and Anti-CD20 it is important mainly for the treatment of non-Hodgkin's lymphomas (NHL). 188 Re (E β = 2.12 MeV; E γ = 155 keV; t1/2 = 16.9 h) is an attractive radionuclide for RIT. However, 188 Re can be obtained from a radionuclide generator of 188 W/ 188 Re, commercially available, making it convenient for use in research and for clinical routine. The CR of IPEN has a project aimed at the production of radiopharmaceutical 188 Re-Anti-CD20, where the radionuclide can be obtained from a generator system 188 W/ 188 Re. With this proposed a study to assess the efficiency of this labeling technique for treatment in accordance compartmental and dosimetry. The objective of this study was to compare the marking of anti-CD20 MAb with 188 Re with the marking of the antibody with 90 Y, 131 I, 177 Lu and 99m Tc (for their similar chemical characteristics) and 211 At, 213 Bi, 223 Ra and 225 Ac); through the study of labeling techniques reported in literature, the proposal of a compartmental model to evaluate its pharmacokinetic and dosimetric studies, high interest for therapy. The result of the study shows a favorable kinetics for 188 Re, by their physical and chemical characteristics compared to the other evaluated radionuclides. The compartment proposed study describes the metabolism of 188 Reanti- CD20 through a compartment mammillary model, which by their pharmacokinetic analysis, performed compared to products emitters β -131 I-labeled anti CD20, 177 Luanti- CD20, the γ emitter 99m Tc-Anti-CD20 and α emitter 211 At-Anti-CD20 presented a elimination constant of approximately 0.05 hours

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

    DEFF Research Database (Denmark)

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

    1988-01-01

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

  13. Cloning and molecular characterization of the cDNAs encoding the variable regions of an anti-CD20 monoclonal antibody.

    Science.gov (United States)

    Shanehbandi, Dariush; Majidi, Jafar; Kazemi, Tohid; Baradaran, Behzad; Aghebati-Maleki, Leili

    2017-01-01

    CD20-based targeting of B-cells in hematologic malignancies and autoimmune disorders is associated with outstanding clinical outcomes. Isolation and characterization of VH and VL cDNAs encoding the variable regions of the heavy and light chains of monoclonal antibodies (MAb) is necessary to produce next generation MAbs and their derivatives such as bispecific antibodies (bsAb) and single-chain variable fragments (scFv). This study was aimed at cloning and characterization of the VH and VL cDNAs from a hybridoma cell line producing an anti-CD20 MAb. VH and VL fragments were amplified, cloned and characterized. Furthermore, amino acid sequences of VH, VL and corresponding complementarity-determining regions (CDR) were determined and compared with those of four approved MAbs including Rituximab (RTX), Ibritumomab tiuxetan, Ofatumumab and GA101. The cloned VH and VL cDNAs were found to be functional and follow a consensus pattern. Amino acid sequences corresponding to the VH and VL fragments also indicated noticeable homologies to those of RTX and Ibritumomab. Furthermore, amino acid sequences of the relating CDRs had remarkable similarities to their counterparts in RTX and Ibritumomab. Successful recovery of VH and VL fragments encourages the development of novel CD20 targeting bsAbs, scFvs, antibody conjugates and T-cells armed with chimeric antigen receptors.

  14. Targeted tumor imaging of anti-CD20-polymeric nanoparticles developed for the diagnosis of B-cell malignancies

    Directory of Open Access Journals (Sweden)

    Capolla S

    2015-06-01

    Full Text Available Sara Capolla,1 Chiara Garrovo,2 Sonia Zorzet,1 Andrea Lorenzon,3 Enrico Rampazzo,4 Ruben Spretz,5 Gabriele Pozzato,6 Luis Núñez,7 Claudio Tripodo,8 Paolo Macor,1,9 Stefania Biffi2 1Department of Life Sciences, University of Trieste, 2Institute for Maternal and Child Health – IRCCS “Burlo Garofolo”, Trieste, 3Animal Care Unit, Cluster in Biomedicine (CBM scrl, Trieste, Italy; 4Department of Chemistry “G. Ciamician”, University of Bologna, Bologna, Italy; 5LNK Chemsolutions LLC, Lincoln, NE, USA; 6Department of Medical, Surgery and Health Sciences, University of Trieste, Trieste, Italy; 7Bio-Target, Inc., University of Chicago, Chicago, IL, USA; 8Department of Human Pathology, University of Palermo, Palermo, Italy; 9Callerio Foundation Onlus, Institutes of Biological Researches, Trieste, Italy Abstract: The expectations of nanoparticle (NP-based targeted drug delivery systems in cancer, when compared with convectional therapeutic methods, are greater efficacy and reduced drug side effects due to specific cellular-level interactions. However, there are conflicting literature reports on enhanced tumor accumulation of targeted NPs, which is essential for translating their applications as improved drug-delivery systems and contrast agents in cancer imaging. In this study, we characterized biodegradable NPs conjugated with an anti-CD20 antibody for in vivo imaging and drug delivery onto tumor cells. NPs’ binding specificity mediated by anti-CD20 antibody was evaluated on MEC1 cells and chronic lymphocytic leukemia patients’ cells. The whole-body distribution of untargeted NPs and anti-CD20 NPs were compared by time-domain optical imaging in a localized human/mouse model of B-cell malignancy. These studies provided evidence that NPs’ functionalization by an anti-CD20 antibody improves tumor pharmacokinetic profiles in vivo after systemic administration and increases in vivo imaging of tumor mass compared to non-targeted NPs. Together

  15. Comparative studies of antibody anti-CD20 labeled with 188Re

    International Nuclear Information System (INIS)

    Dias, Carla Roberta de Barros Rodrigues

    2010-01-01

    Nuclear Medicine is an unique and important modality in oncology and the development of new tumor-targeted radiopharmaceuticals for both diagnosis and therapy is an area of interest for researchers. Rituximab (RTX) is a quimeric monoclonal antibody (mAb) (IgG 1) that specifically binds to CD20 antigen with high affinity and has been successfully used for the treatment of Non-Hodgkin Lymphoma (NHL) of cell B. The CD20 antigen is expressed over more than 90% of cell B NHL. Technetium-99m ( 99m Tc) and rhenium-188 ( 188 Re) are an attractive radionuclide pair for clinical use due to their favorable decay properties for diagnosis ( 99m Tc: T 1/2 = 6 h, γ radiation = 140 keV) and therapy ( 188 Re: T 1/2 = 17 h, maximum β energy = 2.12 MeV) and to their availability in the form of 99 Mo/ 99 mTc and 188 W/ 188 Re generators. The radionuclides can be conjugated to mAb using similar chemical procedures. The aim of this work was to study the labeling of anti-CD20 mAb (RTX) with 188 Re using two techniques: the direct labeling method [ 188 Re(V)] and the labeling method via the carbonyl nucleus [ 188 Re(I)]. Besides the quality control, the radiolabeled mAb was submitted to in vivo, in vitro and ex vivo biological studies. For the direct labeling, RTX was reducing by incubation with 2-mercaptoethanol for generating sulphydryl groups (-SH) and further labeled with 188 Re(V), in a study of several parameters in order to reach an optimized formulation. The labeling via the carbonyl nucleus both 99 mTc and 188 Re were employed through 2 different procedures: (1) labeling of intact RTX with 99 mTc(I) and (2) reduced RTX (RTX red ) labeled with 99 mTc(I)/ 188 Re(I). Also a parameter study was performed to obtain an optimized formulation. The quality control method for evaluating the radiochemical purity showed a good labeling yield (93%) for the direct method. The labeling method via carbonyl group, the results showed that the - SH groups of RTX red are a possible way of labeling

  16. Dosimetry and microdosimetry of 188 Re-anti-CD20 and 131 I-anti-CD20 for the treatment of No Hodgkin lymphomas

    International Nuclear Information System (INIS)

    Torres G, E.

    2007-01-01

    The purpose of this investigation was to prepare 131 I-anti-CD20 and 188 Re-anti-CD20 and to estimate the radiation absorbed dose at macro- and micro- level during a NHL treatment. The work was divided in 4 general objectives: 1) preparation of 131 I-anti-CD20 and 188 Re-anti-CD20, 2) application in patients to obtain biokinetic parameters and estimate the organ absorbed doses 3) estimation of the cellular dosimetry using the MIRD methodology and the MCNP4C2 code and 4) estimation of the cellular microdosimetry using the NOREC code. 188 Re-anti-CD20 was prepared by a direct labelling method using sodium tartrate as a weak ligand. To evaluate the biological recognition a comparative study of the in vitro binding of 188 Re-anti-CD20, 125 I-anti-CD20 (positive control) and 188 Re-anti-CEA (negative control) to normal B Iymphocytes was performed. Biodistribution studies in normal mice were accomplished to assess the in vivo Re-anti-CD20 complex stability. The binding of ' Re-anti-CD20 to cells was in the same range as '251-anti-CD20 (>80%) considered as the positive control. 188 Re-anti-CD20 and '3'1-anti-CD20 prepared were administered in patients diagnosed with B cell NHL at the Centro Medico Siglo XXI (IMSS). The protocol was approved by the hospital's Medical Ethics Committee. AJI patients signed a consent form after receiving detailed information on the aims of the study. N data were the input for the OLINDA/EXM software to calculate the radiation absorbed dose to organs and whole body. Dosimetric studies indicate that after administration of 6.4 GBq and 4.87 to 8.75 GBq of '3'1-anti-CD20 and 188 Re-anti-CD20 respectively, the absorbed dose to total body would be 0.75 Gy which corresponds to the recommended dose for NHL therapies. The calculated organ absorbed doses indicate that 188 Re-anti-CD20 may be used in radioimmunotherapy without the risk of toxicity to red marrow or healthy organs. The absorbed dose (D) into cellular nucleus was calculated by two

  17. Generation of anti-idiotype scFv for pharmacokinetic measurement in lymphoma patients treated with chimera anti-CD22 antibody SM03.

    Directory of Open Access Journals (Sweden)

    Qi Zhao

    Full Text Available Pre-clinical and clinical studies of therapeutic antibodies require highly specific reagents to examine their immune responses, bio-distributions, immunogenicity, and pharmacodynamics in patients. Selective antigen-mimicking anti-idiotype antibody facilitates the assessment of therapeutic antibody in the detection, quantitation and characterization of antibody immune responses. Using mouse specific degenerate primer pairs and splenocytic RNA, we generated an idiotype antibody-immunized phage-displayed scFv library in which an anti-idiotype antibody against the therapeutic chimera anti-CD22 antibody SM03 was isolated. The anti-idiotype scFv recognized the idiotype of anti-CD22 antibody and inhibited binding of SM03 to CD22 on Raji cell surface. The anti-idiotype scFv was subsequently classified as Ab2γ type. Moreover, our results also demonstrated firstly that the anti-idiotype scFv could be used for pharmacokinetic measurement of circulating residual antibody in lymphoma patients treated with chimera anti-CD22 monoclonal antibody SM03. Of important, the present approach could be easily adopted to generate anti-idiotype antibodies for therapeutic antibodies targeting membrane proteins, saving the cost and time for producing a soluble antigen.

  18. Dosimetry and microdosimetry of {sup 188} Re-anti-CD20 and {sup 131} I-anti-CD20 for the treatment of No Hodgkin lymphomas; Dosimetria y microdosimetria del {sup 188} Re-anti-CD20 y {sup 131} I-anti-CD20 para el tratamiento de linfomas No Hodgkin

    Energy Technology Data Exchange (ETDEWEB)

    Torres G, E

    2007-07-01

    The purpose of this investigation was to prepare {sup 131}I-anti-CD20 and {sup 188}Re-anti-CD20 and to estimate the radiation absorbed dose at macro- and micro- level during a NHL treatment. The work was divided in 4 general objectives: 1) preparation of {sup 131}I-anti-CD20 and {sup 188}Re-anti-CD20, 2) application in patients to obtain biokinetic parameters and estimate the organ absorbed doses 3) estimation of the cellular dosimetry using the MIRD methodology and the MCNP4C2 code and 4) estimation of the cellular microdosimetry using the NOREC code. {sup 188}Re-anti-CD20 was prepared by a direct labelling method using sodium tartrate as a weak ligand. To evaluate the biological recognition a comparative study of the in vitro binding of {sup 188}Re-anti-CD20, {sup 125}I-anti-CD20 (positive control) and {sup 188}Re-anti-CEA (negative control) to normal B Iymphocytes was performed. Biodistribution studies in normal mice were accomplished to assess the in vivo Re-anti-CD20 complex stability. The binding of ' Re-anti-CD20 to cells was in the same range as '251-anti-CD20 (>80%) considered as the positive control. {sup 188}Re-anti-CD20 and '3'1-anti-CD20 prepared were administered in patients diagnosed with B cell NHL at the Centro Medico Siglo XXI (IMSS). The protocol was approved by the hospital's Medical Ethics Committee. AJI patients signed a consent form after receiving detailed information on the aims of the study. N data were the input for the OLINDA/EXM software to calculate the radiation absorbed dose to organs and whole body. Dosimetric studies indicate that after administration of 6.4 GBq and 4.87 to 8.75 GBq of '3'1-anti-CD20 and {sup 188}Re-anti-CD20 respectively, the absorbed dose to total body would be 0.75 Gy which corresponds to the recommended dose for NHL therapies. The calculated organ absorbed doses indicate that {sup 188}Re-anti-CD20 may be used in radioimmunotherapy without the risk of toxicity to red marrow or

  19. Dosimetry and microdosimetry of {sup 188} Re-anti-CD20 and {sup 131} I-anti-CD20 for the treatment of No Hodgkin lymphomas; Dosimetria y microdosimetria del {sup 188} Re-anti-CD20 y {sup 131} I-anti-CD20 para el tratamiento de linfomas No Hodgkin

    Energy Technology Data Exchange (ETDEWEB)

    Torres G, E

    2007-07-01

    The purpose of this investigation was to prepare {sup 131}I-anti-CD20 and {sup 188}Re-anti-CD20 and to estimate the radiation absorbed dose at macro- and micro- level during a NHL treatment. The work was divided in 4 general objectives: 1) preparation of {sup 131}I-anti-CD20 and {sup 188}Re-anti-CD20, 2) application in patients to obtain biokinetic parameters and estimate the organ absorbed doses 3) estimation of the cellular dosimetry using the MIRD methodology and the MCNP4C2 code and 4) estimation of the cellular microdosimetry using the NOREC code. {sup 188}Re-anti-CD20 was prepared by a direct labelling method using sodium tartrate as a weak ligand. To evaluate the biological recognition a comparative study of the in vitro binding of {sup 188}Re-anti-CD20, {sup 125}I-anti-CD20 (positive control) and {sup 188}Re-anti-CEA (negative control) to normal B Iymphocytes was performed. Biodistribution studies in normal mice were accomplished to assess the in vivo Re-anti-CD20 complex stability. The binding of ' Re-anti-CD20 to cells was in the same range as '251-anti-CD20 (>80%) considered as the positive control. {sup 188}Re-anti-CD20 and '3'1-anti-CD20 prepared were administered in patients diagnosed with B cell NHL at the Centro Medico Siglo XXI (IMSS). The protocol was approved by the hospital's Medical Ethics Committee. AJI patients signed a consent form after receiving detailed information on the aims of the study. N data were the input for the OLINDA/EXM software to calculate the radiation absorbed dose to organs and whole body. Dosimetric studies indicate that after administration of 6.4 GBq and 4.87 to 8.75 GBq of '3'1-anti-CD20 and {sup 188}Re-anti-CD20 respectively, the absorbed dose to total body would be 0.75 Gy which corresponds to the recommended dose for NHL therapies. The calculated organ absorbed doses indicate that {sup 188}Re-anti-CD20 may be used in radioimmunotherapy without the risk of toxicity to red marrow or healthy organs. The absorbed dose

  20. Construction and characterization of an anti-CD20 mAb nanocomb with exceptionally excellent lymphoma-suppressing activity

    Directory of Open Access Journals (Sweden)

    Li H

    2015-07-01

    Full Text Available Hua-Fei Li,1–3,* Cong Wu,4,* Ting Chen,5,* Ge Zhang,1 He Zhao,1 Chang-Hong Ke,1 Zheng Xu21International Joint Cancer Institute, Translation Medicine Institute, 2Planning Division, Scientific Research Department, 3Tumor Immunology and Gene Therapy Center, Eastern Hepatobiliary Surgery Hospital, 4Department of Laboratory Diagnosis, Changhai Hospital, 5Department of Cardiology, Changhai Hospital, the Second Military Medical University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The CD20-directed monoclonal antibody rituximab (RTX established a new era in the treatment of non-Hodgkin lymphoma (NHL; however, suboptimal response and/or resistance to RTX still limit its clinical merits. Although four effector mechanisms are validated to participate in CD20-based immunotherapy, including complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, caspase-dependent apoptosis, and lysosome-mediated programmed cell death (PCD, they could hardly be synchronously activated by any anti-CD20 mAb or mAb derivative until now. Herein, a novel mAb nanocomb (polyethylenimine polymer–RTX–tositumomab [PPRT nanocomb] was firstly constructed through mass arming two different anti-CD20 mAbs (RTX and tositumomab to one polymer by nanotechnology. Comparing with free mAbs, PPRT nanocomb possesses a comparable binding ability and reduced “off-rate” to surface CD20 of NHL cells. When treated by PPRT nanocomb, the caspase-dependent apoptosis was remarkably enhanced except for concurrently eliciting complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and lysosome-mediated PCD. Besides, “cross-cell link”-assisted homotypic adhesion by PPRT nanocomb further enhanced the susceptibility to PCD of lymphoma cells. Pharmacokinetic assays revealed that PPRT nanocomb experienced a relatively reduced clearance from peripheral blood compared with free antibodies. With

  1. Critical assessment of the efficiency of CD34 and CD133 antibodies for enrichment of rabbit hematopoietic stem cells.

    Science.gov (United States)

    Vašíček, Jaromír; Shehata, Medhat; Schnabl, Susanne; Hilgarth, Martin; Hubmann, Rainer; Jäger, Ulrich; Bauer, Miroslav; Chrenek, Peter

    2018-06-08

    Rabbits have many hereditary diseases common to humans and are therefore a valuable model for regenerative disease and hematopoietic stem cell (HSC) therapies. Currently, there is no substantial data on the isolation and/or enrichment of rabbit HSCs. This study was initiated to evaluate the efficiency of the commercially available anti-CD34 and anti-CD133 antibodies for the detection and potential enrichment of rabbit HSCs from peripheral blood. PBMCs from rabbit and human blood were labelled with different clones of anti-human CD34 monoclonal antibodies (AC136, 581 and 8G12) and rabbit polyclonal CD34 antibody (pCD34) and anti-human CD133 monoclonal antibodies (AC133 and 293C3). Flow cytometry showed a higher percentage of rabbit CD34 + cells labelled by AC136 in comparison to the clone 581 and pCD34 (Penrichment of rabbit CD34 + cells using magnetic-activated cell sorting (MACS). The enrichment of the rabbit CD34 + cells after sorting was low in comparison to human samples (2.4% vs. 39.6%). PCR analyses confirmed the efficient enrichment of human CD34 + cells and the low expression of CD34 mRNA in rabbit positive fraction. In conclusion, the tested antibodies might be suitable for detection, but not for sorting the rabbit CD34 + HSCs and new specific anti-rabbit CD34 antibodies are needed for efficient enrichment of rabbit HSCs. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

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

    International Nuclear Information System (INIS)

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

    2004-01-01

    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 ( 9 0yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ( 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

  4. An anti-CD3/anti-CLL-1 bispecific antibody for the treatment of acute myeloid leukemia.

    Science.gov (United States)

    Leong, Steven R; Sukumaran, Siddharth; Hristopoulos, Maria; Totpal, Klara; Stainton, Shannon; Lu, Elizabeth; Wong, Alfred; Tam, Lucinda; Newman, Robert; Vuillemenot, Brian R; Ellerman, Diego; Gu, Chen; Mathieu, Mary; Dennis, Mark S; Nguyen, Allen; Zheng, Bing; Zhang, Crystal; Lee, Genee; Chu, Yu-Waye; Prell, Rodney A; Lin, Kedan; Laing, Steven T; Polson, Andrew G

    2017-02-02

    Acute myeloid leukemia (AML) is a major unmet medical need. Most patients have poor long-term survival, and treatment has not significantly changed in 40 years. Recently, bispecific antibodies that redirect the cytotoxic activity of effector T cells by binding to CD3, the signaling component of the T-cell receptor, and a tumor target have shown clinical activity. Notably, blinatumomab is approved to treat relapsed/refractory acute lymphoid leukemia. Here we describe the design, discovery, pharmacologic activity, pharmacokinetics, and safety of a CD3 T cell-dependent bispecific (TDB) full-length human IgG1 therapeutic antibody targeting CLL-1 that could potentially be used in humans to treat AML. CLL-1 is prevalent in AML and, unlike other targets such as CD33 and CD123, is not expressed on hematopoietic stem cells providing potential hematopoietic recovery. We selected a high-affinity monkey cross-reactive anti-CLL-1 arm and tested several anti-CD3 arms that varied in affinity, and determined that the high-affinity CD3 arms were up to 100-fold more potent in vitro. However, in mouse models, the efficacy differences were less pronounced, probably because of prolonged exposure to TDB found with lower-affinity CD3 TDBs. In monkeys, assessment of safety and target cell depletion by the high- and low-affinity TDBs revealed that only the low-affinity CD3/CLL1 TDB was well tolerated and able to deplete target cells. Our data suggest that an appropriately engineered CLL-1 TDB could be effective in the treatment of AML. © 2017 by The American Society of Hematology.

  5. Development of a lyophilized formulation for preparing the radiopharmaceutical {sup 177}Lu-DOTA-Anti-CD20; Desarrollo de una formulacion liofilizada para la preparacion del radiofarmaco {sup 177}-DOTA-Anti-CD20

    Energy Technology Data Exchange (ETDEWEB)

    Serrano E, L. A.

    2015-07-01

    The radiolabeled proteins are molecules of interest in nuclear medicine for their diagnostic and therapeutic application in cancer. Antibodies, such as chimeric monoclonal antibody Anti-CD20 rituximab, have established themselves as suitable vectors of radionuclides (e.g. {sup 177}Lu) , introducing high affinity by the surface antigens over- expressed and widely distributed in cells involved in certain diseases. The aim of this work was to design, optimize and document the production process of radiopharmaceutical {sup 177}Lu-DOTA-Anti-CD20 for sanitary registration request to the Comision Federal para la Proteccion contra Riesgos Sanitarios (COFEPRIS). First, a raw material analysis using the Ft-Mir technique and gamma spectrometry was performed. Then, was carried out the development of the lyophilized formulation for the preparation of {sup 177}Lu-DOTA-Anti-CD20, in which an ANOVA was performed where the dependent variable was the radiochemical purity. The optimal pharmaceutical formulation was: 5 mg DOTA-CD20 and 80 mg Mannitol to be reconstituted with 1 m L of acetate buffer 0.25 M, ph 7, with an incubation time of 15 min at 37 degrees Celsius in a dry bath. Once completed the development of the lyophilized formulation, we proceeded to the optimization of the production process, development and validation of the analytical method. Three batches were prepared under protocols of Good Manufacturing Practice, which met pre-established specifications as sterile and endotoxin-free of bacterial formulations, with greater that 95% of radiochemical purity. Currently, is conducting the study of shelf stability. Upon completion of the stability studies, the legal record of {sup 177}Lu-DOTA-Anti-CD20 will be integrated with documented evidence of the quality and stability of the formulation of this radiopharmaceutical. (Author)

  6. Radiolabeled Humanized Anti-CD3 Monoclonal Antibody Visilizumab for Imaging Human T-Lymphocytes

    NARCIS (Netherlands)

    Malviya, Gaurav; D'Alessandria, Calogero; Bonanno, Elena; Vexler, Vladimir; Massari, Roberto; Trotta, Carlo; Scopinaro, Francesco; Dierckx, Rudi; Signore, Alberto

    2009-01-01

    Visilizumab is an IgG(2) humanized monoclonal antibody (mAb) characterized by non-Fc gamma R binding and specific to the CD3 antigen, expressed on more than 95% of circulating resting T-lymphocytes and on activated T-lymphocytes homing in inflamed tissues. We hypothesized that the use of a

  7. N-glycan engineering of a plant-produced anti-CD20-hIL-2 immunocytokine significantly enhances its effector functions.

    Science.gov (United States)

    Marusic, Carla; Pioli, Claudio; Stelter, Szymon; Novelli, Flavia; Lonoce, Chiara; Morrocchi, Elena; Benvenuto, Eugenio; Salzano, Anna Maria; Scaloni, Andrea; Donini, Marcello

    2018-03-01

    Anti-CD20 recombinant antibodies are among the most promising therapeutics for the treatment of B-cell malignancies such as non-Hodgkin lymphomas. We recently demonstrated that an immunocytokine (2B8-Fc-hIL2), obtained by fusing an anti-CD20 scFv-Fc antibody derived from C2B8 mAb (rituximab) to the human interleukin 2 (hIL-2), can be efficiently produced in Nicotiana benthamiana plants. The purified immunocytokine (IC) bearing a typical plant protein N-glycosylation profile showed a CD20 binding activity comparable to that of rituximab and was efficient in eliciting antibody-dependent cell-mediated cytotoxicity (ADCC) of human PBMC against Daudi cells, indicating its fuctional integrity. In this work, the immunocytokine devoid of the typical xylose/fucose N-glycosylation plant signature (IC-ΔXF) and the corresponding scFv-Fc-ΔXF antibody not fused to the cytokine, were obtained in a glyco-engineered ΔXylT/FucT N. benthamiana line. Purification yields from agroinfiltrated plants amounted to 20-35 mg/kg of leaf fresh weight. When assayed for interaction with FcγRI and FcγRIIIa, IC-ΔXF exhibited significantly enhanced binding affinities if compared to the counterpart bearing the typical plant protein N-glycosylation profile (IC) and to rituximab. The glyco-engineered recombinant molecules also exhibited a strongly improved ADCC and complement-dependent cytotoxicity (CDC). Notably, our results demonstrate a reduced C1q binding of xylose/fucose carrying IC and scFv-Fc compared to versions that lack these sugar moieties. These results demonstrate that specific N-glycosylation alterations in recombinant products can dramatically affect the effector functions of the immunocytokine, resulting in an overall improvement of the biological functions and consequently of the therapeutic potential. © 2017 Wiley Periodicals, Inc.

  8. Radiolabeling of anti-CD20 with Re-188 for treatment of Non-Hodgkin's lymphoma: radiochemical control

    International Nuclear Information System (INIS)

    Dias, C.R.; Osso Junior, J.A.

    2008-01-01

    Radioimmunotherapy (RIT) uses target-specific monoclonal antibodies or fragments labeled with a radioactive isotope to combine humoral and radiolytic functions and has the advantage of targeting not only the cell to which the antibody is bound but also the surrounding tumor cells and microenvironment. The most successful clinical studies of RIT in patients with Non-Hodgkin's Lymphoma (NHL) have targeted CD20+ Bcell tumors. Antibody therapy directed against the CD20 antigen on the surface of B-cells is considered one of the first successful target-specific therapies in oncology. The radionuclide rhenium-188 ( 188 Re) is currently produced from the father nuclide 188 W through a transportable generator system. Because of its easy availability and suitable nuclear properties (E βMAX = 2.1 MeV, t1/2 = 16.9 h, E γ = 155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agent and could be conveniently utilized for imaging and dosimetric purposes. The objective of this work is the optimization of direct radiolabeling method of anti-CD20 with 188 Re using a liquid formulation. Anti-CD20 was reduced by incubation with 2-mercaptoethanol at room temperature. The number of resulting free sulphydryl groups was assayed with Ellman's reagent. Optimization of radiolabeling was achieved by varying parameters: antibody mass, reducing agent mass, tartrate mass, stability and reaction time, 188 Re volume and activity. Radiochemical purity of 188 Re-anti-CD20 was evaluated using instant thin layer chromatography-silica gel (ITLC-SG). Quality control methods for evaluation of radiochemical purity showed good labeling yield of the antibody but further studies will be carried out in order to improve the labeling yields and consequently the specific activity of the product. (author)

  9. 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.

  10. HPMA copolymer conjugates with reduced anti-CD20 antibody for cell-specific drug targeting. I. Synthesis and in vitro evaluation of binding efficacy and cytostatic activity

    Czech Academy of Sciences Publication Activity Database

    Etrych, Tomáš; Strohalm, Jiří; Kovář, Lubomír; Kabešová, Martina; Říhová, Blanka; Ulbrich, Karel

    2009-01-01

    Roč. 140, č. 1 (2009), s. 18-26 ISSN 0168-3659 R&D Projects: GA MŠk 1M0505; GA AV ČR IAAX00500803 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50200510 Keywords : HPMA copolymers * drug delivery systems * doxorubicin * monoclonal anti-CD20 antibody * drug targeting Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.949, year: 2009

  11. Anti-CD20 B-cell depletion enhances monocyte reactivity in neuroimmunological disorders

    Directory of Open Access Journals (Sweden)

    Hohlfeld Reinhard

    2011-10-01

    Full Text Available Abstract Background Clinical trials evaluating anti-CD20-mediated B-cell depletion in multiple sclerosis (MS and neuromyelitis optica (NMO generated encouraging results. Our recent studies in the MS model experimental autoimmune encephalomyelitis (EAE attributed clinical benefit to extinction of activated B-cells, but cautioned that depletion of naïve B-cells may be undesirable. We elucidated the regulatory role of un-activated B-cells in EAE and investigated whether anti-CD20 may collaterally diminish regulatory B-cell properties in treatment of neuroimmunological disorders. Methods Myelin oligodendrocyte glycoprotein (MOG peptide-immunized C57Bl/6 mice were depleted of B-cells. Functional consequences for regulatory T-cells (Treg and cytokine production of CD11b+ antigen presenting cells (APC were assessed. Peripheral blood mononuclear cells from 22 patients receiving anti-CD20 and 23 untreated neuroimmunological patients were evaluated for frequencies of B-cells, T-cells and monocytes; monocytic reactivity was determined by TNF-production and expression of signalling lymphocytic activation molecule (SLAM. Results We observed that EAE-exacerbation upon depletion of un-activated B-cells closely correlated with an enhanced production of pro-inflammatory TNF by CD11b+ APC. Paralleling this pre-clinical finding, anti-CD20 treatment of human neuroimmunological disorders increased the relative frequency of monocytes and accentuated pro-inflammatory monocyte function; when reactivated ex vivo, a higher frequency of monocytes from B-cell depleted patients produced TNF and expressed the activation marker SLAM. Conclusions These data suggest that in neuroimmunological disorders, pro-inflammatory APC activity is controlled by a subset of B-cells which is eliminated concomitantly upon anti-CD20 treatment. While this observation does not conflict with the general concept of B-cell depletion in human autoimmunity, it implies that its safety and

  12. The biological activity of human CD20 monoclonal antibodies is linked to unique epitopes on CD20

    NARCIS (Netherlands)

    Teeling, J.L.; Mackus, W.J.M.; Wiegman, L.; Brakel, van den J.H.N.; Beers, S.A.; French, R.R.; Meerten, van T.; Ebeling, S.; Vink, T.; Slootstra, J.W.; Parren, P.; Glennie, M.J.; Winkel, van de J.G.J.

    2006-01-01

    We have previously defined a panel of fully human CD20 mAb. Most of these were unexpectedly efficient in their ability to recruit C1q to the surface of CD20-positive cells and mediate tumor lysis via activation of the classical pathway of complement. This complement-dependent cytotoxicity (CDC)

  13. Development of a lyophilized formulation for preparing the radiopharmaceutical 177Lu-DOTA-Anti-CD20

    International Nuclear Information System (INIS)

    Serrano E, L. A.

    2015-01-01

    The radiolabeled proteins are molecules of interest in nuclear medicine for their diagnostic and therapeutic application in cancer. Antibodies, such as chimeric monoclonal antibody Anti-CD20 rituximab, have established themselves as suitable vectors of radionuclides (e.g. 177 Lu) , introducing high affinity by the surface antigens over- expressed and widely distributed in cells involved in certain diseases. The aim of this work was to design, optimize and document the production process of radiopharmaceutical 177 Lu-DOTA-Anti-CD20 for sanitary registration request to the Comision Federal para la Proteccion contra Riesgos Sanitarios (COFEPRIS). First, a raw material analysis using the Ft-Mir technique and gamma spectrometry was performed. Then, was carried out the development of the lyophilized formulation for the preparation of 177 Lu-DOTA-Anti-CD20, in which an ANOVA was performed where the dependent variable was the radiochemical purity. The optimal pharmaceutical formulation was: 5 mg DOTA-CD20 and 80 mg Mannitol to be reconstituted with 1 m L of acetate buffer 0.25 M, ph 7, with an incubation time of 15 min at 37 degrees Celsius in a dry bath. Once completed the development of the lyophilized formulation, we proceeded to the optimization of the production process, development and validation of the analytical method. Three batches were prepared under protocols of Good Manufacturing Practice, which met pre-established specifications as sterile and endotoxin-free of bacterial formulations, with greater that 95% of radiochemical purity. Currently, is conducting the study of shelf stability. Upon completion of the stability studies, the legal record of 177 Lu-DOTA-Anti-CD20 will be integrated with documented evidence of the quality and stability of the formulation of this radiopharmaceutical. (Author)

  14. Itolizumab – a humanized anti-CD6 monoclonal antibody with better side effects profile for the treatment of psoriasis [Corrigendum

    Directory of Open Access Journals (Sweden)

    Menon R

    2015-06-01

    Full Text Available Menon R, David BG. Clinical, Cosmetic and Investigational Dermatology. 2015;8:215–22.On page 215, please note correspondence should have been listed as:   Roshni Menon, D II/17,JIPMER Campus, Dhanvanthri Nagar,Pondicherry, India 605006Tel +91 944 320 8140Email roshnijagdish@gmail.com.On page 215, the first sentence of the Introduction was “Psoriasis is a chronic inflammatory disease of the skin characterized by exacerbations and remissions affecting 1%–3% of the world’s population, and approximately 20% of patients have moderate to severe disease.1,2” however should have been “Psoriasis is a chronic inflammatory disease of the skin characterized by exacerbations and remissions affecting 1%–3% of the world’s population. Approximately 20% of patients have moderate to severe disease.1,2”On page 217, 219, and 221 the running header was “Itolizumab – aCD6 monoclonal antibody for the treatment of psoriasis” however should have been “Itolizumab – a humanized anti CD6 monoclonal antibody for the treatment of psoriasis”.On page 218, Table 1, the second column heading was listed as “Anand et al25 n=40 (moderate–severe psoriasis” however should have been “Anand et al25 n=40/32 weeks (moderate–severe psoriasis”.Read the original article 

  15. Dosimetric studies of anti-CD20 labeled with therapeutic radionuclides at IPEN/CNEN-SP

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, G.; Dias, C.R.B.R.; Osso Junior, J.A., E-mail: gracielabarrio@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-07-01

    Radioimmunotherapy (RIT) makes use of monoclonal antibodies (MAb) labeled with alpha/beta radionuclides for therapeutical purposes, leading to tumor irradiation and destruction, preserving the normal organs on the radiation excess. The therapeutic activity to be injected in a specific patient is based on information obtained in dosimetric studies. Beta emitting radionuclides such as {sup 131}I, {sup 188}Re, {sup 90}Y, {sup 177}Lu and {sup 166}Ho are useful for the development of therapeutic radiopharmaceuticals. Anti-CD20 (Rituximab) is a chimeric MAb directed against antigen surface CD20 on B-lymphocytes, used in non-Hodgkin lymphoma treatment (NHL). The association with beta radionuclides have shown greater therapeutic efficacy. Currently, two radiopharmaceuticals with Anti-CD20 for radioimmunotherapy have FDA approval for NHL treatment: {sup 131}I-AntiCD20 (Bexar) and {sup 90}Y-AntiCD20 (Zevalin). Techniques for the radiolabeling of {sup 188}Re-antiCD20 have been recently developed by IPEN-CNEN/SP in order to evaluate the clinical use of this radionuclide in particular. The use of {sup 188}Re (T{sub 1/2} 17h) produced by the decay of {sup 188}W (T{sub 1/2} 69d), from an {sup 188}W/{sup 188}Re generator system, has represented an alternative to RIT. Beyond high energy beta emission for therapy, {sup 188}Re also emits gamma rays (155keV) suitable for image. The aim of this new project is to compare the labeling of anti-CD20 with {sup 188}Re with the same MAb labeled with {sup 131}I, {sup 177}Lu, {sup 90}Y and even {sup 99m}Tc. The first step in this project is the review of the published data available concerning the labeling of this MAb with different radionuclides, along with data obtained at IPEN, taking into account labeling procedures, labeling yields, reaction time, level and kind of impurities and biodistribution studies. The pharmacokinetic code will be developed in Visual Studio.NET platform through VB.NET and C{sup ++} for biodistribution and dosimetric

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

    OpenAIRE

    Aghebati Maleki, Leili; Majidi, Jafar; Baradaran, Behzad; Abdolalizadeh, Jalal; Kazemi, Tohid; Aghebati Maleki, Ali; Sineh sepehr, Koushan

    2013-01-01

    Purpose: Monoclonal antibodies or specific antibodies are now an essential tool of biomedical research and are of great commercial and medical value. The purpose of this study was to produce large scale of monoclonal antibody against CD34 in order to diagnostic application in leukemia and purification of human hematopoietic stem/progenitor cells. Methods: For large scale production of monoclonal antibody, hybridoma cells that produce monoclonal antibody against human CD34 were injected into t...

  17. Potent neutralizing anti-CD1d antibody reduces lung cytokine release in primate asthma model.

    Science.gov (United States)

    Nambiar, Jonathan; Clarke, Adam W; Shim, Doris; Mabon, David; Tian, Chen; Windloch, Karolina; Buhmann, Chris; Corazon, Beau; Lindgren, Matilda; Pollard, Matthew; Domagala, Teresa; Poulton, Lynn; Doyle, Anthony G

    2015-01-01

    CD1d is a receptor on antigen-presenting cells involved in triggering cell populations, particularly natural killer T (NKT) cells, to release high levels of cytokines. NKT cells are implicated in asthma pathology and blockade of the CD1d/NKT cell pathway may have therapeutic potential. We developed a potent anti-human CD1d antibody (NIB.2) that possesses high affinity for human and cynomolgus macaque CD1d (KD ∼100 pM) and strong neutralizing activity in human primary cell-based assays (IC50 typically <100 pM). By epitope mapping experiments, we showed that NIB.2 binds to CD1d in close proximity to the interface of CD1d and the Type 1 NKT cell receptor β-chain. Together with data showing that NIB.2 inhibited stimulation via CD1d loaded with different glycolipids, this supports a mechanism whereby NIB.2 inhibits NKT cell activation by inhibiting Type 1 NKT cell receptor β-chain interactions with CD1d, independent of the lipid antigen in the CD1d antigen-binding cleft. The strong in vitro potency of NIB.2 was reflected in vivo in an Ascaris suum cynomolgus macaque asthma model. Compared with vehicle control, NIB.2 treatment significantly reduced bronchoalveolar lavage (BAL) levels of Ascaris-induced cytokines IL-5, IL-8 and IL-1 receptor antagonist, and significantly reduced baseline levels of GM-CSF, IL-6, IL-15, IL-12/23p40, MIP-1α, MIP-1β, and VEGF. At a cellular population level NIB.2 also reduced numbers of BAL lymphocytes and macrophages, and blood eosinophils and basophils. We demonstrate that anti-CD1d antibody blockade of the CD1d/NKT pathway modulates inflammatory parameters in vivo in a primate inflammation model, with therapeutic potential for diseases where the local cytokine milieu is critical.

  18. Itolizumab – a humanized anti-CD6 monoclonal antibody with a better side effects profile for the treatment of psoriasis

    Directory of Open Access Journals (Sweden)

    Menon R

    2015-04-01

    Full Text Available Roshni Menon, Brinda G David Department of Dermatology, Venereology and Leprosy, Sri Venkateshwaraa Medical College Hospital and Research Centre, Ariyur, Pondicherry, India Abstract: Management of psoriasis is a challenge to the treating physician. The chronic inflammatory state of psoriasis with exacerbations and remissions necessitate “on-and-off” treatment schedules. The safety profiles of drugs and tolerability issues for patients are important factors to be considered during treatment. Various biological agents targeting T-cells and the inflammatory cytokines are available for systemic treatment of psoriasis. However, major causes of concern while using these drugs are risk of susceptibility to infection and development of anti-drug antibodies, which will affect the pharmacokinetic properties, efficacy, and safety profile of the drug. Itolizumab, a humanized anti-CD6 monoclonal antibody, is a new molecule that acts by immunomodulating the CD6 molecule. CD6 is a co-stimulatory molecule required for optimal T-cell stimulation by the antigen-presenting cells. This step is crucial in T-cell proliferation to form Th1 and Th17 cells, which play a major role in the pathogenesis of psoriasis. This article deals with the properties of Itolizumab and its role in the treatment of psoriasis. Based on the available published data, Itolizumab seems to have a better adverse effects profile and at the same time comparatively less efficacy when compared to other biological agents available for treating psoriasis. Larger studies with longer duration are required to clearly depict the long-term side effects profile. Keywords: Itolizumab, CD6, psoriasis, monoclonal antibody, biologicals 

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

    Directory of Open Access Journals (Sweden)

    Isabel Fofana

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

  20. Signaling signatures and functional properties of anti-human CD28 superagonistic antibodies.

    Directory of Open Access Journals (Sweden)

    Zoe Waibler

    Full Text Available Superagonistic CD28 antibodies (CD28SAs activate T lymphocytes without concomitant perturbation of the TCR/CD3-complex. In rodents these reagents induce the preferential expansion of regulatory T cells and can be used for the treatment of autoimmune diseases. Unexpectedly, the humanized CD28 superagonist TGN1412 caused severe and life threatening adverse effects during a recently conducted phase I clinical trail. The underlying molecular mechanisms are as yet unclear. We show that TGN1412 as well as the commercially available CD28 superagonist ANC28.1 induce a delayed but extremely sustained calcium response in human naïve and memory CD4+ T cells but not in cynomolgus T lymphocytes. The sustained Ca++-signal was associated with the activation of multiple intracellular signaling pathways and together these events culminated in the rapid de novo synthesis of high amounts of pro-inflammatory cytokines, most notably IFN-gamma and TNF-alpha. Importantly, sustained transmembranous calcium flux, activation of Src-kinases as well as activation of PI3K were found to be absolutely required for CD28SA-mediated production of IFN-gamma and IL-2. Collectively, our data suggest a molecular basis for the severe side effects caused by TGN1412 and impinge upon the relevance of non-human primates as preclinical models for reagents that are supposed to modify the function of human T cells.

  1. High soluble CD30 levels and associated anti-HLA antibodies in patients with failed renal allografts.

    Science.gov (United States)

    Karahan, Gonca E; Caliskan, Yasar; Ozdilli, Kursat; Kekik, Cigdem; Bakkaloglu, Huseyin; Caliskan, Bahar; Turkmen, Aydin; Sever, Mehmet S; Oguz, Fatma S

    2017-01-13

    Serum soluble CD30 (sCD30), a 120-kD glycoprotein that belongs to the tumor necrosis factor receptor family, has been suggested as a marker of rejection in kidney transplant patients. The aim of this study was to evaluate the relationship between sCD30 levels and anti-HLA antibodies, and to compare sCD30 levels in patients undergoing hemodialysis (HD) with and without failed renal allografts and transplant recipients with functioning grafts. 100 patients undergoing HD with failed grafts (group 1), 100 patients undergoing HD who had never undergone transplantation (group 2), and 100 kidney transplant recipients (group 3) were included in this study. Associations of serum sCD30 levels and anti-HLA antibody status were analyzed in these groups. The sCD30 levels of group 1 and group 2 (154 ± 71 U/mL and 103 ± 55 U/mL, respectively) were significantly higher than those of the transplant recipients (group 3) (39 ± 21 U/mL) (p<0.001 and p<0.001). The serum sCD30 levels in group 1 (154 ± 71 U/mL) were also significantly higher than group 2 (103 ± 55 U/mL) (p<0.001). Anti-HLA antibodies were detected in 81 (81%) and 5 (5%) of patients in groups 1 and 2, respectively (p<0.001). When multiple regression analysis was performed to predict sCD30 levels, the independent variables in group 1 were the presence of class I anti-HLA antibodies (β = 0.295; p = 0.003) and age (β = -0.272; p = 0.005), and serum creatinine (β = 0.218; p = 0.027) and presence of class II anti-HLA antibodies (standardized β = 0.194; p = 0.046) in group 3. Higher sCD30 levels and anti-HLA antibodies in patients undergoing HD with failed renal allografts may be related to higher inflammatory status in these patients.

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

    Directory of Open Access Journals (Sweden)

    Koushan Sineh sepehr

    2013-02-01

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

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

    Science.gov (United States)

    Aghebati Maleki, Leili; Majidi, Jafar; Baradaran, Behzad; Abdolalizadeh, Jalal; Kazemi, Tohid; Aghebati Maleki, Ali; Sineh sepehr, Koushan

    2013-01-01

    Purpose: Monoclonal antibodies or specific antibodies are now an essential tool of biomedical research and are of great commercial and medical value. The purpose of this study was to produce large scale of monoclonal antibody against CD34 in order to diagnostic application in leukemia and purification of human hematopoietic stem/progenitor cells. Methods: For large scale production of monoclonal antibody, hybridoma cells that produce monoclonal antibody against human CD34 were injected into the peritoneum of the Balb/c mice which have previously been primed with 0.5 ml Pristane. 5 ml ascitic fluid was harvested from each mouse in two times. Evaluation of mAb titration was assessed by ELISA method. The ascitic fluid was examined for class and subclasses by ELISA mouse mAb isotyping Kit. mAb was purified from ascitic fluid by affinity chromatography on Protein A-Sepharose. Purity of monoclonal antibody was monitored by SDS -PAGE and the purified monoclonal antibody was conjugated with FITC. Results: Monoclonal antibodies with high specificity and sensitivity against human CD34 by hybridoma technology were prepared. The subclass of antibody was IgG1 and its light chain was kappa. Conclusion: The conjugated monoclonal antibody could be a useful tool for isolation, purification and characterization of human hematopoietic stem cells. PMID:24312838

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

    Science.gov (United States)

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

    2016-01-20

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

  5. The in vivo mechanism of action of CD20 monoclonal antibodies depends on local tumor burden

    Science.gov (United States)

    Boross, Peter; Jansen, J.H. Marco; de Haij, Simone; Beurskens, Frank J.; van der Poel, Cees E.; Bevaart, Lisette; Nederend, Maaike; Golay, Josée; van de Winkel, Jan G.J.; Parren, Paul W.H.I.; Leusen, Jeanette H.W.

    2011-01-01

    Background CD20 monoclonal antibodies are widely used in clinical practice. Antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity and direct cell death have been suggested to be important effector functions for CD20 antibodies. However, their specific contributions to the in vivo mechanism of action of CD20 immunotherapy have not been well defined. Design and Methods Here we studied the in vivo mechanism of action of type I (rituximab and ofatumumab) and type II (HuMab-11B8) CD20 antibodies in a peritoneal, syngeneic, mouse model with EL4-CD20 cells using low and high tumor burden. Results Interestingly, we observed striking differences in the in vivo mechanism of action of CD20 antibodies dependent on tumor load. In conditions of low tumor burden, complement was sufficient for tumor killing both for type I and type II CD20 antibodies. In contrast, in conditions of high tumor burden, activating FcγR (specifically FcγRIII), active complement and complement receptor 3 were all essential for tumor killing. Our data suggest that complement-enhanced antibody-dependent cellular cytotoxicity may critically affect tumor killing by CD20 antibodies in vivo. The type II CD20 antibody 11B8, which is a poor inducer of complement activation, was ineffective against high tumor burden. Conclusions Tumor burden affects the in vivo mechanism of action of CD20 antibodies. Low tumor load can be eliminated by complement alone, whereas elimination of high tumor load requires multiple effector mechanisms. PMID:21880632

  6. [Study of anti-idiotype antibodies to human monoclonal antibody].

    Science.gov (United States)

    Harada, R; Takahashi, N; Owaki, I; Kannagi, R; Endo, N; Morita, N; Inoue, M

    1992-02-01

    A human monoclonal antibody, ll-50 (IgM, lambda), was generated, which reacted specifically with a major of glycolipid present in LS174T colon cancer cells. The glycolipid antigen which reacted with the ll-50 antibody was expected to four sugar residues from its TLC mobility, and it was ascertained that the glycolipid antigen which reacted with ll-50 antibody might be Lc4 antigen [Gal beta 1----3 GLcNAc beta 1----3 Gal beta 1----4 Glc beta 1----1 Cer] judging from TLC immunostaining and ELISA when the reactivity of ll-50 antibody was tested using various pure glycolipids in 3-5 sugar residues as an antigen. Sera in patients with malignant disorders and healthy individuals were analyzed by Sandwich assay of immobilized and biotinylated ll-50 antibody. The serum of the Lc4 antigen recognized by ll-50 antibody was significantly higher in patients with malignant disorders than that in healthy individuals (p less than 0.05). Three mouse monoclonal anti-idiotype antibodies, G3, B3 and C5 (all IgG1), were generated by the immunization of BALB/c mice with ll-50 antibody. These anti-idiotype antibodies specifically bound to to human monoclonal antibody, ll-50 and had a significant inhibitory activity towards the binding of ll-50 antibody to the Lc4 antigen. This indicated that these anti-idiotype antibodies, G3, B3, and C5, were paratope-related anti-idiotype antibodies. G3, B3, and C5 were expected to define the nearest idiotope because they could mutually inhibit ll-50 antibody. Sera in patients with malignant disorders and healthy individuals were analyzed by Sandwich assay of immobilized and biotinylated anti-idiotype antibodies, G3, B3, and C5. As to the ll-50 like antibodies defined by C5 (Id-C5+), the mean serum level in patients with malignant disorders was significantly higher than that in healthy individuals (p less than 0.05). As to the ll-50 like antibodies defined by B3 (Id-B3+), the mean serum level in patients with malignant disorders was significantly higher

  7. Bispecific antibodies targeting human CD73

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to a bispecific antibody targeting CD73. In particular, the present invention relates to a bispecific antibody targeting different epitopes on CD73 or a bispecific antibody targeting an epitope on CD73 and an epitope on a different antigen.......The present invention relates to a bispecific antibody targeting CD73. In particular, the present invention relates to a bispecific antibody targeting different epitopes on CD73 or a bispecific antibody targeting an epitope on CD73 and an epitope on a different antigen....

  8. Multivalent system for therapy of non-Hod king lymphomas based on Anti-CD20 conjugated to gold nanoparticles; Sistema multivalente para terapia de linfomas no-Hodking basado en Anti-CD20 conjugado a nanoparticulas de oro

    Energy Technology Data Exchange (ETDEWEB)

    Miranda O, R. M.

    2014-07-01

    In recent publications has been reported that gold nanoparticles have an effect in reducing the expression of the oncogene Bcl -2 and have a high biocompatibility , this is the importance for using gold nanoparticles for this work. The antibody CD20 is an antibody that specifically binds to that over expressed CD20 antigen on the cell membrane of B lymphoma cell non- Hodgkin (cell line Raji) behold the importance of combining this bio molecule to gold nanoparticles since they have a high specificity with CD20 positive cells , also to carry out the antigen- antibody immunological reactions triggered mediating cell lysis, possibly by cytotoxicity and apoptosis. Therefore, this system must have characteristics of both components to eliminate B cell non- Hodgkin lymphoma.In this work it was studied a multivalent system composed of gold nanoparticles and anti-CD20 antibody, the term multi valency refers to the number of biomolecules attached to the surface of the gold nanoparticle. The synthesis and characterization of the gold nanoparticles and the multivalent system was performed and the effect of the multivalent system on the expression of oncogene Bcl-2 (group of proteins associated with the apoptotic pathway) was evaluated. Characterization of raw materials and the multivalent system was performed using spectroscopic and microscopic techniques, this to verify structural changes in raw materials and thus confirm the formation of CD20 binding to the surface of the nanoparticle gold by the bond between gold and sulfur in the cysteines of CD20. Taking advantage that the metal nanoparticles have the optical property of surface plasmon resonance, the absorption of gold nanoparticles was measured on the UV-Vis as it is affected by the surface molecules bind to it, showing a bathochromic displacement effected. The hydrodynamic diameter of the gold nanoparticles was measured to verify that the antibody is bound to the surface; this evidence was complemented by micrographs

  9. Anti-microbial antibodies in celiac disease: Trick or treat?

    Science.gov (United States)

    Papp, Maria; Foldi, Ildiko; Altorjay, Istvan; Palyu, Eszter; Udvardy, Miklos; Tumpek, Judit; Sipka, Sandor; Korponay-Szabo, Ilma Rita; Nemes, Eva; Veres, Gabor; Dinya, Tamas; Tordai, Attila; Andrikovics, Hajnalka; Norman, Gary L; Lakatos, Peter Laszlo

    2009-01-01

    AIM: To determine the prevalence of a new set of anti-glycan and anti-outer membrane protein (anti-OMP) antibodies in a Hungarian cohort of adult Celiac disease (CD) patients. METHODS: 190 consecutive CD patients [M/F: 71/119, age:39.9 (SD:14.1) years], 100 healthy, and 48 gastrointestinal controls were tested for glycan anti-Saccharomyces cerevisiae (gASCA), anti-laminaribioside (ALCA), anti-chitobioside, anti-mannobioside, anti-OMP antibodies and major NOD2/CARD15 mutations. Thirty out of 82 CD patients enrolled at the time of diagnosis were re-evaluated for the same antibodies after longstanding gluten-free diet (GFD). RESULTS: 65.9% of the CD patients were positive for at least one of the tested antibodies at the time of the diagnosis. Except anti-OMP and ALCA, anti-microbial antibodies were exclusively seen in untreated CD; however, the overall sensitivity was low. Any glycan positivity (LR+: 3.13; 95% CI: 2.08-4.73) was associated with an increased likelihood ratio for diagnosing CD. Significant correlation was found between the levels of anti-glycan and anti-endomysial or anti-transglutaminase antibodies. Anti-glycan positivity was lost after longstanding GFD. Anti-glycan antibody titers were associated with symptoms at presentation, but not the presence of NOD2/CARD15 mutations. Patients with severe malabsorption more frequently had multiple antibodies at diagnosis (P = 0.019). CONCLUSION: The presence of anti-glycan antibodies in CD seems to be secondary to the impaired small bowel mucosa which can lead to increased antigen presentation. Furthermore, anti-glycan positivity may be considered an additional marker of CD and dietary adherence. PMID:19701969

  10. Clearance of 131I-labeled murine monoclonal antibody from patients' blood by intravenous human anti-murine immunoglobulin antibody

    International Nuclear Information System (INIS)

    Stewart, J.S.; Sivolapenko, G.B.; Hird, V.; Davies, K.A.; Walport, M.; Ritter, M.A.; Epenetos, A.A.

    1990-01-01

    Five patients treated with intraperitoneal 131I-labeled mouse monoclonal antibody for ovarian cancer also received i.v. exogenous polyclonal human anti-murine immunoglobulin antibody. The pharmacokinetics of 131I-labeled monoclonal antibody in these patients were compared with those of 28 other patients receiving i.p.-radiolabeled monoclonal antibody for the first time without exogenous human anti-murine immunoglobulin, and who had no preexisting endogenous human anti-murine immunoglobulin antibody. Patients receiving i.v. human anti-murine immunoglobulin antibody demonstrated a rapid clearance of 131I-labeled monoclonal antibody from their circulation. The (mean) maximum 131I blood content was 11.4% of the injected activity in patients receiving human anti-murine immunoglobulin antibody compared to 23.3% in patients not given human anti-murine immunoglobulin antibody. Intravenous human anti-murine immunoglobulin antibody decreased the radiation dose to bone marrow (from 131I-labeled monoclonal antibody in the vascular compartment) 4-fold. Following the injection of human anti-murine immunoglobulin antibody, 131I-monoclonal/human anti-murine immunoglobulin antibody immune complexes were rapidly transported to the liver. Antibody dehalogenation in the liver was rapid, with 87% of the injected 131I excreted in 5 days. Despite the efficient hepatic uptake of immune complexes, dehalogenation of monoclonal antibody was so rapid that the radiation dose to liver parenchyma from circulating 131I was decreased 4-fold rather than increased. All patients developed endogenous human anti-murine immunoglobulin antibody 2 to 3 weeks after treatment

  11. Anti-CD40-mediated cancer immunotherapy

    DEFF Research Database (Denmark)

    Hassan, Sufia Butt; Sørensen, Jesper Freddie; Olsen, Barbara Nicola

    2014-01-01

    activation and thus enhancement of immune responses. Treatment with anti-CD40 monoclonal antibodies has been exploited in several cancer immunotherapy studies in mice and led to the development of anti-CD40 antibodies for clinical use. Here, Dacetuzumab and Lucatumumab are in the most advanced stage...... with other cancer immunotherapies, in particular interleukin (IL)-2. An in-depth analysis of this immunotherapy is provided elsewhere. In the present review, we provide an update of the most recent clinical trials with anti-CD40 antibodies. We present and discuss recent and ongoing clinical trials...... in this field, including clinical studies which combine anti-CD40 treatment with other cancer-treatments, such as Rituximab and Tremelimumab....

  12. Anti-CD20 Immunoglobulin G Radiolabeling with a 99mTc-Tricarbonyl Core: In Vitro and In Vivo Evaluations.

    Directory of Open Access Journals (Sweden)

    Hélène Carpenet

    Full Text Available In recent years, the diagnostic and therapeutic uses of radioisotopes have shown significant progress. Immunoglobulin (Ig appears to be a promising tracer, particularly due to its ability to target selected antigens. The main objective of this study is to optimize and assess an Ig radiolabeling method with Technetium 99m (99mTc, an attractive radioelement used widely for diagnostic imaging. Monoclonal anti-CD20 IgG was retained to study in vitro and in vivo radiolabeling impact. After IgG derivatization with 2-iminothiolane, IgG-SH was radiolabeled by an indirect method, using a 99mTc-tricarbonyl core. Radiolabeling stability was evaluated over 24h by thin-layer chromatography. IgG integrity was checked by sodium dodecyl sulfate-polyacrylamide gel electrophoresis coupled with Western blot and autoradiography. The radiolabeled Ig's immunoaffinity was assessed in vitro by a radioimmunoassay method and binding experiments with cells (EL4-hCD20 and EL4-WT. Biodistribution studies were performed in normal BALB/c mice. Tumor uptake was assessed in mice bearing EL4-hCD20 and EL4-WT subcutaneous xenografts. With optimized method, high radiolabeling yields were obtained (95.9 ± 3.5%. 99mTc-IgG-SH was stable in phosphate-buffered saline (4°C and 25°C and in serum (37°C, even if important sensitivity to transchelation was observed. IgG was not degraded by derivatization and radiolabeling, as shown by Western blot and autoradiography results. 99mTc-anti-CD20 IgG-SH immunoaffinity was estimated with Kd = 35 nM by both methods. In vivo biodistribution studies for 48h showed significant accumulation of radioactivity in plasma, liver, spleen, lungs and kidneys. Planar scintigraphy of mice bearing tumors showed a significant uptake of 99mTc-anti-CD20 IgG-SH in CD20+ tumor versus CD20- tumor. Radiolabeling of derivatized IgG with 99mTc-tricarbonyl was effective, stable and required few antibody amounts. This attractive radiolabeling method is "antibody safe

  13. In vitro experimental (211)At-anti-CD33 antibody therapy of leukaemia cells overcomes cellular resistance seen in vivo against gemtuzumab ozogamicin.

    Science.gov (United States)

    Petrich, Thorsten; Korkmaz, Zekiye; Krull, Doris; Frömke, Cornelia; Meyer, Geerd J; Knapp, Wolfram H

    2010-05-01

    Monoclonal anti-CD33 antibodies conjugated with toxic calicheamicin derivative (gemtuzumab ozogamicin, GO) are a novel therapy option for acute myeloid leukaemia (AML). Key prognostic factors for patients with AML are high CD33 expression on the leukaemic cells and the ability to overcome mechanisms of resistance to cytotoxic chemotherapies, including drug efflux or other mechanisms decreasing apoptosis. Alpha particle-emitting radionuclides overwhelm such anti-apoptotic mechanisms by producing numerous DNA double-stranded breaks (DSBs) accompanied by decreased DNA repair. We labelled anti-CD33 antibodies with the alpha-emitter (211)At and compared survival of leukaemic HL-60 and K-562 cells treated with the (211)At-labelled antibodies, GO or unlabelled antibodies as controls. We also measured caspase-3/7 activity, DNA fragmentation and necrosis in HL-60 cells after treatment with the different antibodies or with free (211)At. The mean labelling ratio of (211)At-labelled antibodies was 1:1,090 +/- 364 (range: 1:738-1:1,722) in comparison to 2-3:1 for GO. Tumour cell binding of (211)At-anti-CD33 was high in the presence of abundant CD33 expression and could be specifically blocked by unlabelled anti-CD33. (211)At-anti-CD33 decreased survival significantly more than did GO at comparable dilution (1:1,000). No significant differences in induction of apoptosis or necrosis or DNA DSB or in decreased survival were observed after (211)At-anti-CD33 (1:1,090) versus GO (1:1) treatment. Our results suggest that (211)At is a promising, highly cytotoxic radioimmunotherapy in CD33-positive leukaemia and kills tumour cells more efficiently than does calicheamicin-conjugated antibody. Labelling techniques leading to higher chemical yield and specific activities must be developed to increase (211)At-anti-CD33 therapeutic effects.

  14. Purification of a polyclonal antibody against CD147 for ELISA using antigen-immunoaffinity chromatography

    Science.gov (United States)

    Liu, Shuangshuang; Li, Shasha; Zhang, Yang; Wang, Ye; Zhu, Yumeng; Wang, Bin; Chen, Zhi-Nan

    2017-01-01

    The immunoglobulin superfamily member CD147 is a widely expressed glycoprotein that occurs in both a membrane-spanning and soluble form. Sandwich ELISA is a powerful tool for analyzing soluble antigens. The aim of the present study was to obtain a highly specific polyclonal antibody against human CD147 that can be used for sandwich ELISA analysis. Expression of recombinant CD147 by a eukaryotic expression system was used to immunize rabbits to obtain antiserum. A highly specific polyclonal antibody that was able to detect soluble CD147 in sandwich ELISA was obtained by antigen-immunoaffinity chromatography purification. The purity of rabbit anti-CD147 polyclonal antibodies was ~99%, and ELISA analysis was able to determine the titer of the rabbit anti-CD147 polyclonal antibodies at 1:512,000. The lowest concentration of the standard CD147 antigen that the sandwich ELISA was able to detect was 31.25 pg/ml. The sandwich ELISA system was composed of anti-hepatoma HAb18 monoclonal antibodies and purified rabbit anti-CD147 polyclonal antibodies. The present study demonstrated that antigen-immunoaffinity chromatography may be a good technique for the purification of polyclonal antibodies, which may be used to detect antigen in sandwich ELISAs. PMID:28487989

  15. Association of Anti-glycan Antibodies and Inflammatory Bowel Disease Course.

    Science.gov (United States)

    Paul, S; Boschetti, G; Rinaudo-Gaujous, M; Moreau, A; Del Tedesco, E; Bonneau, J; Presles, E; Mounsef, F; Clavel, L; Genin, C; Flourié, B; Phelip, J-M; Nancey, S; Roblin, X

    2015-06-01

    The usefulness of anti-glycan antibodies alone or combined with anti-Saccharomyces cerevisiae [ASCA] or perinuclear antineutrophil cytoplasmic [pANCA] antibodies for diagnosis of inflammatory bowel disease [IBD], differentiation between Crohn's disease [CD] and ulcerative colitis [UC], disease stratification including IBD phenotype, and also for determination of the course of the disease, remain unclear. A large panel of serological anti-glycan carbohydrate antibodies, including anti-mannobioside IgG antibodies [AMCA], anti-chitobioside IgA [ACCA], anti-laminaribioside IgG antibodies [ALCA], anti-laminarin [anti-L] and anti-chitine [anti-C] were measured in the serum from a cohort of 195 patients with IBD] [107 CD and 88 UC]. The respective accuracy of isolated or combined markers for diagnosis, disease differentiation, stratification disease phenotype, and severity of the disease course, defined by a wide panel of criteria obtained from the past medical history, was assessed. The positivity of at least one anti-glycan antibody was detected in a significant higher proportion of CD and UC compared with healthy controls [p ACCA [> 51U/ml] and anti-laminarin [> 31U/ml] were significantly linked with a higher association with steroid dependency (odds ratio [OR] =2.0 [1.0-4.0], p = 0.03 and OR = 2.4 [1.1-5.2], p = 0.02, respectively]. We further defined the respective performance of anti-glycan antibodies to discriminate between patients with severe or not severe CD and UC course and determined the associated optimal cut-off values: severe CD course was significantly more likely in case of AMCA > 77U/ml [OR = 4.3; p = 0.002], ASCA > 63U/ml [OR = 3.5; p ACCA > 50U/ml [OR = 2.8; p 52U/ml [OR = 3.4; p = 0.04] and ACCA > 25U/ml [OR = 3.0; p < 0.04]. Anti-glycan antibodies are valuable serological markers, especially AMCA antibodies that may help clinicians to promptly classify patients into high risk for severe disease. Copyright © 2015 European Crohn’s and Colitis

  16. 77 FR 41792 - Prospective Grant of Co-Exclusive License: The Development of Human Anti-CD22 Monoclonal...

    Science.gov (United States)

    2012-07-16

    ... applications for the technology family, to Customized Therapeutics. The patent rights in these inventions have... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Prospective Grant of Co-Exclusive License: The Development of Human Anti-CD22 Monoclonal Antibodies for the Treatment of Human...

  17. High affinity anti-TIM-3 and anti-KIR monoclonal antibodies cloned from healthy human individuals.

    Directory of Open Access Journals (Sweden)

    Stefan Ryser

    Full Text Available We report here the cloning of native high affinity anti-TIM-3 and anti-KIR IgG monoclonal antibodies (mAbs from peripheral blood mononuclear cells (PBMC of healthy human donors. The cells that express these mAbs are rare, present at a frequency of less than one per 105 memory B-cells. Using our proprietary multiplexed screening and cloning technology CellSpot™ we assessed the presence of memory B-cells reactive to foreign and endogenous disease-associated antigens within the same individual. When comparing the frequencies of antigen-specific memory B-cells analyzed in over 20 screening campaigns, we found a strong correlation of the presence of anti-TIM-3 memory B-cells with memory B-cells expressing mAbs against three disease-associated antigens: (i bacterial DNABII proteins that are a marker for Gram negative and Gram positive bacterial infections, (ii hemagglutinin (HA of influenza virus and (iii the extracellular domain of anaplastic lymphoma kinase (ALK. One of the native anti-KIR mAbs has similar characteristics as lirilumab, an anti-KIR mAb derived from immunization of humanized transgenic mice that is in ongoing clinical trials. It is interesting to speculate that these native anti-TIM-3 and anti-KIR antibodies may function as natural regulatory antibodies, analogous to the pharmacological use in cancer treatment of engineered antibodies against the same targets. Further characterization studies are needed to define the mechanisms through which these native antibodies may function in healthy and disease conditions.

  18. Characterization of a Broadly Reactive Anti-CD40 Agonistic Monoclonal Antibody for Potential Use as an Adjuvant.

    Directory of Open Access Journals (Sweden)

    Cameron Martin

    Full Text Available Lack of safe and effective adjuvants is a major hindrance to the development of efficacious vaccines. Signaling via CD40 pathway leads to enhanced antigen processing and presentation, nitric oxide expression, pro-inflammatory cytokine expression by antigen presenting cells, and stimulation of B-cells to undergo somatic hypermutation, immunoglobulin class switching, and proliferation. Agonistic anti-CD40 antibodies have shown promising adjuvant qualities in human and mouse vaccine studies. An anti-CD40 monoclonal antibody (mAb, designated 2E4E4, was identified and shown to have strong agonistic effects on primary cells from multiple livestock species. The mAb recognize swine, bovine, caprine, and ovine CD40, and evoked 25-fold or greater proliferation of peripheral blood mononuclear cells (PBMCs from these species relative to cells incubated with an isotype control (p<0.001. In addition, the mAb induced significant nitric oxide (p<0.0001 release by bovine macrophages. Furthermore, the mAb upregulated the expression of MHC-II by PBMCs, and stimulated significant (p<0.0001 IL-1α, IL6, IL-8, and TNF-α expression by PBMCs. These results suggest that the mAb 2E4E4 can target and stimulate cells from multiple livestock species and thus, it is a potential candidate for adjuvant development. This is the first study to report an anti-swine CD40 agonistic mAb that is also broadly reactive against multiple species.

  19. The human CD38 monoclonal antibody daratumumab shows anti-tumor activity and hampers leukemia-microenvironment interactions in chronic lymphocytic leukemia

    Science.gov (United States)

    Matas-Céspedes, Alba; Vidal-Crespo, Anna; Rodriguez, Vanina; Villamor, Neus; Delgado, Julio; Giné, Eva; Roca-Ho, Heleia; Menéndez, Pablo; Campo, Elías; López-Guillermo, Armando; Colomer, Dolors; Roué, Gaël; Wiestner, Adrian; Parren, Paul W.H.I.; Doshi, Parul; van Bueren, Jeroen Lammerts; Pérez-Galán, Patricia

    2016-01-01

    Purpose To establish a proof-of-concept for the efficacy of the anti-CD38 antibody daratumumab in the poor prognosis CD38+ CLL subtype. Experimental design The mechanism of action of daratumumab was assessed in CLL primary cells and cell lines using peripheral blood mononuclear cells to analyze antibody-dependent cell cytotoxicity (ADCC), murine and human macrophages to study antibody-dependent cell phagocytosis (ADCP) or human serum to analyze complement-dependent cytotoxicity (CDC). The effect of daratumumab on CLL cell migration and adhesion to extracellular matrix was characterized. Daratumumab activity was validated in two in vivo models. Results Daratumumab demonstrated efficient lysis of patient-derived CLL cells and cell lines by ADCC in vitro and ADCP both in vitro and in vivo, while exhibited negligible CDC in these cells. To demonstrate the therapeutic effect of daratumumab in CLL, we generated a disseminated CLL mouse model with the CD38+ MEC2 cell line and CLL patient derived xenografts (CLL-PDX). Daratumumab significantly prolonged overall survival of MEC2 mice, completely eliminated cells from the infiltrated organs and significantly reduced disease burden in the spleen of CLL-PDX. The effect of daratumumab on patient-derived CLL cell dissemination was demonstrated in vitro by its effect on CXCL12-induced migration and in vivo by interfering with CLL cell homing to spleen in NSG mice. Daratumumab also reduced adhesion of CLL cells to VCAM-1, accompanied by down-regulation of the matrix metalloproteinase MMP9. Conclusions These unique and substantial effects of daratumumab on CLL viability and dissemination support the investigation of its use in a clinical setting of CLL. PMID:27637890

  20. In vitro experimental {sup 211}At-anti-CD33 antibody therapy of leukaemia cells overcomes cellular resistance seen in vivo against gemtuzumab ozogamicin

    Energy Technology Data Exchange (ETDEWEB)

    Petrich, Thorsten; Korkmaz, Zekiye; Krull, Doris; Meyer, Geerd J.; Knapp, Wolfram H. [Hanover University School of Medicine, Department of Nuclear Medicine, Hanover (Germany); Froemke, Cornelia [Hanover University School of Medicine, Department of Biometry, Hanover (Germany)

    2010-05-15

    Monoclonal anti-CD33 antibodies conjugated with toxic calicheamicin derivative (gemtuzumab ozogamicin, GO) are a novel therapy option for acute myeloid leukaemia (AML). Key prognostic factors for patients with AML are high CD33 expression on the leukaemic cells and the ability to overcome mechanisms of resistance to cytotoxic chemotherapies, including drug efflux or other mechanisms decreasing apoptosis. Alpha particle-emitting radionuclides overwhelm such anti-apoptotic mechanisms by producing numerous DNA double-stranded breaks (DSBs) accompanied by decreased DNA repair. We labelled anti-CD33 antibodies with the alpha-emitter {sup 211}At and compared survival of leukaemic HL-60 and K-562 cells treated with the {sup 211}At-labelled antibodies, GO or unlabelled antibodies as controls. We also measured caspase-3/7 activity, DNA fragmentation and necrosis in HL-60 cells after treatment with the different antibodies or with free {sup 211}At. The mean labelling ratio of {sup 211}At-labelled antibodies was 1:1,090 {+-} 364 (range: 1:738-1:1,722) in comparison to 2-3:1 for GO. Tumour cell binding of {sup 211}At-anti-CD33 was high in the presence of abundant CD33 expression and could be specifically blocked by unlabelled anti-CD33. {sup 211}At-anti-CD33 decreased survival significantly more than did GO at comparable dilution (1:1,000). No significant differences in induction of apoptosis or necrosis or DNA DSB or in decreased survival were observed after {sup 211}At-anti-CD33 (1:1,090) versus GO (1:1) treatment. Our results suggest that {sup 211}At is a promising, highly cytotoxic radioimmunotherapy in CD33-positive leukaemia and kills tumour cells more efficiently than does calicheamicin-conjugated antibody. Labelling techniques leading to higher chemical yield and specific activities must be developed to increase {sup 211}At-anti-CD33 therapeutic effects. (orig.)

  1. CD47 limits antibody dependent phagocytosis against non-malignant B cells.

    Science.gov (United States)

    Gallagher, Sandra; Turman, Sean; Lekstrom, Kristen; Wilson, Susan; Herbst, Ronald; Wang, Yue

    2017-05-01

    Recent studies have demonstrated the importance of CD47 in protecting malignant B cells from antibody dependent cellular phagocytosis (ADCP). Combined treatment of anti-CD47 and -CD20 antibodies synergistically augment elimination of tumor B cells in xenograft mouse models. This has led to the development of novel reagents that can potentially enhance killing of malignant B cells in patients. B cell depleting therapy is also a promising treatment for autoimmune patients. In the current study, we aimed to investigate whether or not CD47 protects non-malignant B cells from ADCP. We show that CD47 is expressed on all B cells in mice, with the highest level on plasma cells in bone marrow and spleen. Although its expression is dispensable for B cell development in mice, CD47 on B cells limits antibody mediated phagocytosis. B cell depletion following in vivo anti-CD19 treatment is more efficient in CD47-/- mice than in wild type mice. In vitro, both naïve and activated B cells from CD47-/- mice are more sensitive to ADCP than wild type B cells. Lastly, we show in an ADCP assay that blocking CD47 can enhance anti-CD19 antibody mediated phagocytosis of wild type B cells. These results suggest that in addition to its already demonstrated benefit in cancer, targeting CD47 may be used as an adjunct in combination with B cell depletion antibodies for treatment of autoimmune diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Synthesis and Characterization of Anti-HER2 Antibody Conjugated CdSe/CdZnS Quantum Dots for Fluorescence Imaging of Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Takashi Jin

    2009-11-01

    Full Text Available The early detection of HER2 (human epidermal growth factor receptor 2 status in breast cancer patients is very important for the effective implementation of anti-HER2 antibody therapy. Recently, HER2 detections using antibody conjugated quantum dots (QDs have attracted much attention. QDs are a new class of fluorescent materials that have superior properties such as high brightness, high resistance to photo-bleaching, and multi-colored emission by a single-light source excitation. In this study, we synthesized three types of anti-HER2 antibody conjugated QDs (HER2Ab-QDs using different coupling agents (EDC/sulfo-NHS, iminothiolane/sulfo-SMCC, and sulfo-SMCC. As water-soluble QDs for the conjugation of antibody, we used glutathione coated CdSe/CdZnS QDs (GSH-QDs with fluorescence quantum yields of 0.23~0.39 in aqueous solution. Dispersibility, hydrodynamic size, and apparent molecular weights of the GSH-QDs and HER2Ab-QDs were characterized by using dynamic light scattering, fluorescence correlation spectroscopy, atomic force microscope, and size-exclusion HPLC. Fluorescence imaging of HER2 overexpressing cells (KPL-4 human breast cancer cell line was performed by using HER2Ab-QDs as fluorescent probes. We found that the HER2Ab-QD prepared by using SMCC coupling with partially reduced antibody is a most effective probe for the detection of HER2 expression in KPL-4 cells. We have also studied the size dependency of HER2Ab-QDs (with green, orange, and red emission on the fluorescence image of KPL-4 cells.

  3. Initial clinical trial of epratuzumab (humanized anti-CD22 antibody) for immunotherapy of systemic lupus erythematosus.

    Science.gov (United States)

    Dörner, Thomas; Kaufmann, Joerg; Wegener, William A; Teoh, Nick; Goldenberg, David M; Burmester, Gerd R

    2006-01-01

    B cells play an important role in the pathogenesis of systemic lupus erythematosus (SLE), so the safety and activity of anti-B cell immunotherapy with the humanized anti-CD22 antibody epratuzumab was evaluated in SLE patients. An open-label, single-center study of 14 patients with moderately active SLE (total British Isles Lupus Assessment Group (BILAG) score 6 to 12) was conducted. Patients received 360 mg/m2 epratuzumab intravenously every 2 weeks for 4 doses with analgesic/antihistamine premedication (but no steroids) prior to each dose. Evaluations at 6, 10, 18 and 32 weeks (6 months post-treatment) follow-up included safety, SLE activity (BILAG score), blood levels of epratuzumab, B and T cells, immunoglobulins, and human anti-epratuzumab antibody (HAHA) titers. Total BILAG scores decreased by > or = 50% in all 14 patients at some point during the study (including 77% with a > or = 50% decrease at 6 weeks), with 92% having decreases of various amounts continuing to at least 18 weeks (where 38% showed a >/= 50% decrease). Almost all patients (93%) experienced improvements in at least one BILAG B- or C-level disease activity at 6, 10 and 18 weeks. Additionally, 3 patients with multiple BILAG B involvement at baseline had completely resolved all B-level disease activities by 18 weeks. Epratuzumab was well tolerated, with a median infusion time of 32 minutes. Drug serum levels were measurable for at least 4 weeks post-treatment and detectable in most samples at 18 weeks. B cell levels decreased by an average of 35% at 18 weeks and remained depressed at 6 months post-treatment. Changes in routine safety laboratory tests were infrequent and without any consistent pattern, and there was no evidence of immunogenicity or significant changes in T cells, immunoglobulins, or autoantibody levels. In patients with mild to moderate active lupus, 360 mg/m2 epratuzumab was well tolerated, with evidence of clinical improvement after the first infusion and durable clinical

  4. Multivalent system for therapy of non-Hod king lymphomas based on Anti-CD20 conjugated to gold nanoparticles

    International Nuclear Information System (INIS)

    Miranda O, R. M.

    2014-01-01

    In recent publications has been reported that gold nanoparticles have an effect in reducing the expression of the oncogene Bcl -2 and have a high biocompatibility , this is the importance for using gold nanoparticles for this work. The antibody CD20 is an antibody that specifically binds to that over expressed CD20 antigen on the cell membrane of B lymphoma cell non- Hodgkin (cell line Raji) behold the importance of combining this bio molecule to gold nanoparticles since they have a high specificity with CD20 positive cells , also to carry out the antigen- antibody immunological reactions triggered mediating cell lysis, possibly by cytotoxicity and apoptosis. Therefore, this system must have characteristics of both components to eliminate B cell non- Hodgkin lymphoma.In this work it was studied a multivalent system composed of gold nanoparticles and anti-CD20 antibody, the term multi valency refers to the number of biomolecules attached to the surface of the gold nanoparticle. The synthesis and characterization of the gold nanoparticles and the multivalent system was performed and the effect of the multivalent system on the expression of oncogene Bcl-2 (group of proteins associated with the apoptotic pathway) was evaluated. Characterization of raw materials and the multivalent system was performed using spectroscopic and microscopic techniques, this to verify structural changes in raw materials and thus confirm the formation of CD20 binding to the surface of the nanoparticle gold by the bond between gold and sulfur in the cysteines of CD20. Taking advantage that the metal nanoparticles have the optical property of surface plasmon resonance, the absorption of gold nanoparticles was measured on the UV-Vis as it is affected by the surface molecules bind to it, showing a bathochromic displacement effected. The hydrodynamic diameter of the gold nanoparticles was measured to verify that the antibody is bound to the surface; this evidence was complemented by micrographs

  5. Bioactivity assays and application of 125I labeled human mouse chimeric anti-CD22 monoclonal antibody SM03

    International Nuclear Information System (INIS)

    Lu Pingping; Meng Zhiyun; Dou Guifang; Wu Yingliang; Wang Minwei

    2008-01-01

    To investigate the bioactivity and application of 125 I labeled human mouse chimeric monoclonal SM03, SM03 was labeled with 125 I using Indogen method. The labeled mixture was purified by Sephacryl S-300 HR separation chromospectry. The purity and concentration of separated fractions were determined by HPLC and Protein Assay Kit, respectively. Competitive binding method and ELISA method were used for bioactivity assays. 125 I-SM03 was applied to screen cell lines which express the most abundant CD22 antigen. The purity and recovery of 125 I-SM03 were >99% and >47%, respectively. The bioactivity of 125 I- SM03 and SM03 hasn't significant difference in statistics. Ramos cell line had the strongest special radioactivity when 125 I-SM03 bound with in Raji, Daudi and Ramos cell lines. Indogen method is a good way to label Human mouse chimeric anti-CD22 monoclonal antibody SM03 and the label will not affect the activity of SM03. The 125 I-SM03 not only can be used for detect agent, but also may be put into market for NHL therapy. (authors)

  6. T cell activation and differentiation is modulated by a CD6 domain 1 antibody Itolizumab.

    Directory of Open Access Journals (Sweden)

    Usha Bughani

    Full Text Available CD6 is associated with T-cell modulation and is implicated in several autoimmune diseases. We previously demonstrated that Itolizumab, a CD6 domain 1 (CD6D1 specific humanized monoclonal antibody, inhibited the proliferation and cytokine production by T lymphocytes stimulated with anti-CD3 antibody or when co-stimulated with ALCAM. Aberrant IL-17 producing CD4+ helper T-cells (Th17 have been identified as pivotal for the pathogenesis of certain inflammatory autoimmune disorders, including psoriasis. Itolizumab has demonstrated efficacy in human diseases known to have an IL-17 driven pathogenesis. Here, in in vitro experiments we show that by day 3 of human PBMC activation using anti-CD3 and anti-CD28 co-stimulation in a Th17 polarizing milieu, 15-35% of CD4+ T-cells overexpress CD6 and there is an establishment of differentiated Th17 cells. Addition of Itolizumab reduces the activation and differentiation of T cells to Th17 cells and decreases production of IL-17. These effects are associated with the reduction of key transcription factors pSTAT3 and RORγT. Further, transcription analysis studies in these conditions indicate that Itolizumab suppressed T cell activation by primarily reducing cell cycle, DNA transcription and translation associated genes. To understand the mechanism of this inhibition, we evaluated the effect of this anti-human CD6D1 mAb on ALCAM-CD6 as well as TCR-mediated T cell activation. We show that Itolizumab but not its F(ab'2 fragment directly inhibits CD6 receptor hyper-phosphorylation and leads to subsequent decrease in associated ZAP70 kinase and docking protein SLP76. Since Itolizumab binds to CD6 expressed only on human and chimpanzee, we developed an antibody binding specifically to mouse CD6D1. This antibody successfully ameliorated the incidence of experimental autoimmune encephalitis in the mice model. These results position CD6 as a key molecule in sustaining the activation and differentiation of T cells and an

  7. The experimental study on biodistribution and radioimmunoimaging of 131I labeled anti-lymphoma Fab antibody in nude mice bearing human B cell lymphoma

    International Nuclear Information System (INIS)

    Yang Xiaochun; Zhang Meihua; Shen Junkang; Shen Yongmei; Shi Yizhen; Liu Zengli

    2008-01-01

    Objective: Radioimmunoimaging is still an interesting study in the domain of nuclear medicine. The aim of this study was to evaluate the biodistribution and radioimmunoimaging of 131 I-Fab anti- body in nude mice beating human B cell lymphoma. Methods: The immunoreactivity of Fab antibody to Raji cells was analyzed by immunohistochemistry and flow cytometry. Fab antibody and CD20 monoclonal antibody (as control) were labeled with 131 I using Iodogen method. 131 I-Fab antibody or 131 I-CD20 was injected into nude mice bearing B cell lymphoma via tail veins. The biodistribution and radioimmunoimaging results were obtained at 2, 4, 8 and 24 h postinjection, respectively. Results: The results of immunohistochemistry and flow cytometry indicated that both Fab antibody and 131 I-Fab antibody could bind strongly with membrane antigens on Raji cells, and the binding rate reached above 87%. Clear tumor image was obtained at 8 h after injection with 131 I-Fab and elimination was observed at 24 h postinjection. The clear tumor image for 131 I-CD20 antibody was obtained at 24 h post injection. The biodistribution in vivo showed that the percentage activities of injection dose per gram of tumor (% ID/g) of 131 I-Fab group at 2, 4, 8 h postinjection were higher than that of 131 I-CD20 antibody [(1.37±0.28), (1.84±0.13), (2.21±0.15)% ID/g vs (0.33±0.06), (0.62±0.08), (1.46±0.24)% ID/g, respectively; F=52.22, 278.42 and 29.00, all P 131 I-Fad and 131 I-CD20 groups at 2, 4, 8 and 24 h were [(0.22±0.03)-(5.44± 0.31)] vs[(0.04±0.01)-(3.10±0.29)], [(0.43±0.11) - (21.01±3.97)] vs [(0.11±0.05) - (7.99±1.81)], [(1.09±0.07) -(20.28±2.77)] vs [(0.48±0.06) - (23.55±1.69)], [(1.12± 0.02) - (10.29±1.78)] vs [(2.32 ± 0.34) - (33.23±6.83)], respectively. Conclusion: 131 I-Fab anti- body has advantages of small molecular weight, excellent targeting characteristics, early imaging and fast elimination, which indicates the potential application value in diagnosing B cell

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

    International Nuclear Information System (INIS)

    Watanabe, Mamoru; Chen, Zheng W.; Tsubota, Hiroshi; Lord, C.I.; Levine, C.G.; Letvin, N.L.

    1991-01-01

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

  9. CD44v10, osteopontin and lymphoma growth retardation by a CD44v10-specific antibody.

    Science.gov (United States)

    Megaptche, Amelie Pajip; Erb, Ulrike; Büchler, Markus Wolfgang; Zöller, Margot

    2014-09-01

    Blockade of CD44 is considered a therapeutic option for the elimination of leukemia-initiating cells. However, the application of anti-panCD44 can be burdened by severe side effects. We determined whether these side effects could be avoided by replacing anti-panCD44 with CD44 variant isoform (CD44v)-specific antibodies in CD44v-positive hematological malignancies using the EL4 thymoma and CD44v10-transfected EL4 (EL4-v10) as models. Subcutaneous growth of EL4 and EL4-v10 was equally well inhibited by the anti-panCD44 and anti-CD44v10 antibodies, respectively. Ex vivo analysis indicated that natural killer cytotoxicity and antibody-dependent cellular cytotoxicity were the main effector mechanisms. Under local inflammation, the efficacy of anti-CD44v10 prolonged the survival time twofold compared with untreated, EL4-v10 tumor-bearing mice, and this was due to inflammation-induced expression of osteopontin (OPN). A high level of OPN in EL4-v10 tumors supported leukocyte recruitment and tumor-infiltrating T-cell activation. Taken together, in hematological malignancies expressing CD44v, anti-panCD44 can be replaced by CD44v-specific antibodies without a loss in efficacy. Furthermore, CD44v10-specific antibodies appear particularly advantageous in cutaneous leukemia therapy, as CD44v10 binding of OPN drives leukocyte recruitment and activation.

  10. Generation and Characterization of Anti-CD34 Monoclonal Antibodies that React with Hematopoietic Stem Cells

    Science.gov (United States)

    Aghebati Maleki, Leili; Majidi, Jafar; Baradaran, Behzad; Movassaghpour, Aliakbar; Abdolalizadeh, Jalal

    2014-01-01

    CD34 is a type I membrane protein with a molecular mass of approximately 110 kDa. This antigen is associated with human hematopoietic progenitor cells and is a differentiation stage-specific leukocyte antigen. In this study we have generated and characterized monoclonal antibodies (mAbs) directed against a CD34 marker. Mice were immunized with two keyhole lympet hemocyanin (KLH)-conjugated CD34 peptides. Fused cells were grown in hypoxanthine, aminopterine and thymidine (HAT) selective medium and cloned by the limiting dilution (L.D) method. Several monoclones were isolated by three rounds of limited dilutions. From these, we chose stable clones that presented sustained antibody production for subsequent characterization. Antibodies were tested for their reactivity and specificity to recognize the CD34 peptides and further screened by enzyme-linked immunosorbent assay (ELISA) and Western blotting analyses. One of the mAbs (3D5) was strongly reactive against the CD34 peptide and with native CD34 from human umbilical cord blood cells (UCB) in ELISA and Western blotting analyses. The results have shown that this antibody is highly specific and functional in biomedical applications such as ELISA and Western blot assays. This monoclonal antibodies (mAb) can be a useful tool for isolation and purification of human hematopoietic stem cells (HSCs). PMID:24611141

  11. Minimal contribution of cell-bound antibodies to the immunoscintigraphy of inflamed joints with 99mTc-anti-CD4 monoclonal antibodies

    International Nuclear Information System (INIS)

    Kinne, R.W.; Palombo-Kinne, E.; Wolski, A.; Wolf, F.; Emmrich, F.; Becker, W.

    2002-01-01

    Aim: The cellular joint infiltrate in rheumatoid arthritis patients is rich in CD4-positive T-helper lymphocytes and macrophages, rendering anti-CD4 monoclonal antibodies (mAbs) suitable for specific immunoscintigraphy of human/experimental arthritis. Following intravenous injection, however, mAbs are present both in the free form and bound to CD4-positive, circulating monocytes and T-cells. Thus, the present study aimed at analyzing the relative contribution of the free and the cell-bound component to the imaging of inflamed joints in experimental adjuvant arthritis (AA). Methods: AA rat pertioneal macrophages or lymph node T-cells were incubated in vitro with saturating amounts of 99mTc-anti-CD4 mAb (W3/25) and injected i.v. into rats with AA. Results: In vitro release of 99m Tc-anti-CD4 mAb from the cells was limited (on average 1.57%/h for macrophages and 0.84%/h for T-cells). Following i.v. injection, whole body/joints scans and tissue measurements showed only negligible accumulation of radioactivity in inflamed ankle joints (tissue: 0.22 and 0.34% of the injected activity, respectively), whereas the radioactivity was concentrated in liver (tissue: 79% and 71%, respectively), kidney, and urinary bladder. Unlike macrophages, however, anti-CD4 mAb-coated T-cells significantly accumulated in lymphoid organs, the inflamed synovial membrane of the ankle joints, as well as in elbow and knee joints. Conclusion: While the overall contribution of cell-bound mAbs to the imaging of arthritic joints with anti-CD4 mAbs is minimal, differential accumulation of macrophages and T-cells in lymphoid organs and the inflamed synovial membrane indicates preferential migration patterns of these 2 cell populations in arthritic rats. Although only validated for 99m Tc-anti-CD4 mAbs, extrapolation of the results to other anticellular mAbs with similar affinity for their antigen may be possible. (orig.) [de

  12. Early post-transplant immune monitoring can predict long-term kidney graft survival: soluble CD30 levels, anti-HLA antibodies and IgA-anti-Fab autoantibodies.

    Science.gov (United States)

    Amirzargar, Mohammad Ali; Amirzargar, Aliakbar; Basiri, Abbas; Hajilooi, Mehrdad; Roshanaei, Ghodratollah; Rajabi, Gholamreza; Mohammadiazar, Sina; Solgi, Ghasem

    2014-01-01

    This study aimed to investigate the predictive power of anti-HLA antibodies, sCD30 levels and IgA-anti-Fab autoantibody before and early after transplantation in relation to long-term kidney allograft survival. Pre- and post-transplant sera samples of 59 living-unrelated donor kidney recipients were tested for above risk factors by enzyme-linked immunoabsorbent assay. 15 out of 59 cases experienced rejection episodes (failure group). Pre- and post-transplant high sCD30 levels were significantly associated with graft failure (P=0.02 and P=0.004) and decreased 4 year graft survival (P = 0.009 and P = 0.001). Higher frequency of post-transplant HLA class-II antibody in the absence of class-I antibody was observed in failure group (P=0.007). Patients with post-transplant HLA class-I and class-II antibodies either alone or in combination showed significant lower 4 year graft survival. Recipients with high sCD30 levels in the presence of HLA class-I or class-II antibodies within 2 weeks post-transplant had poor graft survival (P = 0.004 and P = 0.002, respectively). High levels of post-transplant IgA-anti-Fab antibody was more frequent in functioning-graft patients (P = 0.00001), correlated with decreased serum creatinine levels (P = 0.01) and associated with improved graft survival (P = 0.008). Our findings indicate the deleterious effect of early post-transplant HLA antibodies and increased sCD30 levels dependently and protective effect of IgA-anti-Fab antibodies on long-term renal graft outcomes. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2014-04-01

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

  14. Prolonged skin graft survival by administration of anti-CD80 monoclonal antibody with cyclosporin A

    NARCIS (Netherlands)

    Ossevoort, MA; Lorre, K; Boon, L; van den Hout, Y; de Boer, M; De Waele, P; Jonker, M; VandeVoorde, A

    Costimulation via the B7/CD28 pathway is an important signal for the activation of T cells. Maximal inhibition of T-cell activation and the induction of alloantigen-specific nonresponsiveness in vitro was achieved using anti-CD80 monoclonal antibody (mAb) in combination with cyclosporin A (CsA).

  15. Increased levels of anti-glycan antibodies in patients with cystic fibrosis

    Directory of Open Access Journals (Sweden)

    Hirche TO

    2011-09-01

    Full Text Available Abstract Background The prevalence of Crohn's disease (CD is increased in patients with cystic fibrosis (CF. Anti-Saccharomyces cerevisiae antibodies (ASCA have been suggested as a screening tool to detect CD in CF. Recently, several new anti-glycan antibodies have been reported in CD. Materials and methods The sera of 119 CF patients of various age groups were prospectively screened for ASCA type IgG (gASCA, anti-laminaribioside carbohydrate IgG antibodies (ALCA, anti-chitobioside carbohydrate IgA antibodies (ACCA, and anti-mannobioside carbohydrate IgG antibodies (AMCA. The frequency of these anti-glycan antibodies was then compared in patients with CD, ulcerative colitis, rheumatoid arthritis and healthy volunteers. Results A significant number of CF patients were positive for gASCA (51.3% [41.6-60.6] and up to three other anti-glycan antibodies concurrently. Serum levels of anti-glycan antibodies in CF and CD were not related to parameters of inflammation. Despite the well-documented difference in clinical course between male and female CF patients no gender difference of anti-glycan antibodies was found. In contrast, there was a significant positive correlation between anti-glycan markers and age in CF patients. Conclusions Our findings demonstrate for the first time the increased frequency of a panel of anti-glycan antibodies in CF and provide a link between the presence of these serological biomarkers and patient's age. Anti-glycan antibody profiling may therefore become a valuable tool in the care of patients with CF.

  16. Advantages of Papio anubis for preclinical testing of immunotoxicity of candidate therapeutic antagonist antibodies targeting CD28

    Science.gov (United States)

    Poirier, Nicolas; Mary, Caroline; Le Bas-Bernardet, Stephanie; Daguin, Veronique; Belarif, Lyssia; Chevalier, Melanie; Hervouet, Jeremy; Minault, David; Ville, Simon; Charpy, Vianney; Blancho, Gilles; Vanhove, Bernard

    2014-01-01

    Antagonist anti-CD28 antibodies prevent T-cell costimulation and are functionally different from CTLA4Ig since they cannot block CTLA-4 and PDL-1 co-inhibitory signals. They demonstrated preclinical efficacy in suppressing effector T cells while enhancing immunoregulatory mechanisms. Because a severe cytokine release syndrome was observed during the Phase 1 study with the superagonist anti-CD28 TGN1412, development of other anti-CD28 antibodies requires careful preclinical evaluation to exclude any potential immunotoxicity side-effects. The failure to identify immunological toxicity of TGN1412 using macaques led us to investigate more relevant preclinical models. We report here that contrary to macaques, and like in man, all baboon CD4-positive T lymphocytes express CD28 in their effector memory cells compartment, a lymphocyte subtype that is the most prone to releasing cytokines after reactivation. Baboon lymphocytes are able to release pro-inflammatory cytokines in vitro in response to agonist or superagonist anti-CD28 antibodies. Furthermore, we compared the reactivity of human and baboon lymphocytes after transfer into non obese diabetic/severe combined immunodeficiency (NOD/SCID) interleukin-2rγ knockout mice and confirmed that both cell types could release inflammatory cytokines in situ after injection of agonistic anti-CD28 antibodies. In contrast, FR104, a monovalent antagonistic anti-CD28 antibody, did not elicit T cell activation in these assays, even in the presence of anti-drug antibodies. Infusion to baboons also resulted in an absence of cytokine release. In conclusion, the baboon represents a suitable species for preclinical immunotoxicity evaluation of anti-CD28 antibodies because their effector memory T cells do express CD28 and because cytokine release can be assessed in vitro and trans vivo. PMID:24598534

  17. Comparison of anti-CD3 and anti-CD28-coated beads with soluble anti-CD3 for expanding human T cells: Differing impact on CD8 T cell phenotype and responsiveness to restimulation

    Directory of Open Access Journals (Sweden)

    Kurlander Roger J

    2010-10-01

    Full Text Available Abstract Background The ability to expand virus- or tumor-specific T cells without damaging their functional capabilities is critical for success adoptive transfer immunotherapy of patients with opportunistic infection or tumor. Careful comparisons can help identify expansion methods better suited for particular clinical settings and identify recurrent deficiencies requiring new innovation. Methods We compared the efficacy of magnetic beads coated with anti-CD3 and anti-CD28 (anti-CD3/CD28 beads, and soluble anti-CD3 plus mixed mononuclear cells (designated a rapid expansion protocol or REP in expanding normal human T cells. Results Both anti-CD3/CD28 beads and soluble anti-CD3 promoted extensive expansion. Beads stimulated greater CD4 cell growth (geometric mean of 56- versus 27-fold (p Conclusions Anti-CD3/CD28 beads are highly effective for expanding CD4 cells, but soluble anti-CD3 has significant potential advantages for expanding CD8 T cells, particularly where preservation of phenotypically "young" CD8 cells would be desirable, or where the T cells of interest have been antigen-stimulated in vitro or in vivo in the recent past.

  18. Anti-VEGF antibody conjugated CdHgTe quantum dots as a fluorescent probe for imaging in living mouse

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Lili; Cui, Hongjing [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing (China); Liu, Yu [Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing (China); Zhong, Wenying, E-mail: wyzhong@cpu.edu.cn [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing (China); Key laboratory of Biomedical Functional Materials, China Pharmaceutical University, Nanjing (China)

    2016-05-15

    The dual-function anti-VEGF antibody conjugated CdHgTe quantum dots with good targeting property was successfully prepared. In this system, anti-VEGF antibody is not only a target agent but also a therapeutic drug. The anti-VEGF antibody conjugated near-infrared quantum dots can achieve the purposes of detection and treatment at the same time. As-prepared dual-function fluorescent probe in this work has been successfully applied for in vivo and in vitro imaging, which is promising in rapid tumor detection.

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

    Science.gov (United States)

    Barriuso, Begoña; Antolín, Pilar; Arias, F Javier; Girotti, Alessandra; Jiménez, Pilar; Cordoba-Diaz, Manuel; Cordoba-Diaz, Damián; Girbés, Tomás

    2016-06-10

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

  20. Anti-CD74 antibodies have no diagnostic value in early axial spondyloarthritis: data from the spondyloarthritis caught early (SPACE) cohort.

    Science.gov (United States)

    de Winter, Janneke J; van de Sande, Marleen G; Baerlecken, Niklas; Berg, Inger; Ramonda, Roberta; van der Heijde, Désirée; van Gaalen, Floris A; Witte, Torsten; Baeten, Dominique L

    2018-03-01

    Anti-CD74 IgG antibodies are reported to be elevated in patients with axial spondyloarthritis (axSpA). This study assessed the diagnostic value of anti-CD74 antibodies in patients with early axSpA. Anti-CD74 IgG and IgA antibodies were first measured in an exploratory cohort of patients with radiographic axSpA (138 patients with ankylosing spondyloarthritis (AS)) and 57 healthy controls and then were measured in patients with early axSpA (n = 274) and with non-SpA chronic back pain (CBP) (n = 319), participating in the spondyloarthritis caught early (SPACE) prospective cohort study of patients under 45 years old with early back pain (for ≥ 3 months, but ≤ 2 years). In the exploratory cohort, anti-CD74 IgG antibodies were present in 79.7% of patients with AS vs. 43.9% of healthy controls (p present in 28.5% of patients with AS vs. 5.3% of healthy controls (p present in 46.4% of the patients with axSpA vs. 47.9% of the patients with CBP (p = 0.71). Anti-CD74 IgA antibodies were present in 54.7% of the patients with axSpA and 37.0% of the patients with CBP (p value of 58.8% (compared to a prior probability of 46.2%) and a negative predictive value of 59.1% (compared to a prior probability of 53.8%). In a regression model, total serum IgA was associated with axSpA odds ratio (OR) 1.19, p value in patients under 45 years old presenting with early back pain.

  1. Generation of chimeric bispecific G250/anti-CD3 monoclonal antibody, a tool to combat renal cell carcinoma

    NARCIS (Netherlands)

    Luiten, R. M.; Coney, L. R.; Fleuren, G. J.; Warnaar, S. O.; Litvinov, S. V.

    1996-01-01

    The monoclonal antibody (MAb) G250 binds to a tumour-associated antigen, expressed in renal cell carcinoma (RCC), which has been demonstrated to be a suitable target for antibody-mediated immunotherapy. A bispecific antibody having both G250 and anti-CD3 specificity can cross-link G250

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

    Directory of Open Access Journals (Sweden)

    Begoña Barriuso

    2016-06-01

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

  3. Evaluation of the cell death mechanisms activated by the radiopharmaceutical 177Lu-DOTA-anti-CD20 in a dose range of 1 to 5 Gy

    International Nuclear Information System (INIS)

    Azorin V, E.P.; Rojas C, E. L.; Martinez V, B. E.; Ramos B, J. C.; Jimenez M, N. P.; Ferro F, G.

    2016-10-01

    The radio immunotherapy with anti-CD20 antibodies significantly increases the remission rate of patients with B-cell lymphomas over expressing the CD20. The radiolabeled antibodies directed to surface antigens allow delivering scaled doses of radiation to specific targets thus limiting the dose to healthy tissue. The anti-CD20 causes cell death by two major pathways; activating the immune system to destroy malignant cells and inducing the activation of cell death pathways. The 177 Lu is a beta particle emitter (max. 0.497 MeV) with a maximum reach on soft tissue of 0.7 mm and a half-life of 6.7 days. Several clinical studies have established a maximum tolerated dose (45 m Ci/m 2 ) for 177 Lu-DOTA-rituximab, which shows a favorable clinical response without hematological toxicity. However, the molecular mechanisms of action by synergistic effect of anti-CD20 and radionuclide have not been studied. In this work was evaluated; by flow cytometry, the activation kinetics of the cell death mechanisms induced by the treatment with 177 Lu-DOTA-Anti-CD20 in non-Hodgkin (Raji) lymphoma cells. The absorbed radiation dose delivered to the cell nucleus was calculated by Monte Carlo simulation, considering the contribution of the beta emissions of the radiopharmaceutical present in the cell membrane and surrounding environment, as well as crossfire. This work shows that the application of radiation doses of 1 to 5 Gy of the radiopharmaceutical 177 Lu-DOTA-anti-CD20, are sufficient to induce cell death by apoptosis and arrest of the cell cycle. The combination of these factors (continuous delivery of radiation, activation of repair mechanisms and increased radio sensitivity) causes the acute activation of the apoptotic program resulting in significant cell death after 96 h of treatment. The temporal analysis of cell death suggests the early activation of apoptosis that is counteracted by the activation of repair processes caused by sustained irradiation, which leads to cell

  4. Novel anti-Sialyl-Tn monoclonal antibodies and antibody-drug conjugates demonstrate tumor specificity and anti-tumor activity.

    Science.gov (United States)

    Prendergast, Jillian M; Galvao da Silva, Ana Paula; Eavarone, David A; Ghaderi, Darius; Zhang, Mai; Brady, Dane; Wicks, Joan; DeSander, Julie; Behrens, Jeff; Rueda, Bo R

    Targeted therapeutics that can differentiate between normal and malignant tumor cells represent the ideal standard for the development of a successful anti-cancer strategy. The Sialyl-Thomsen-nouveau antigen (STn or Sialyl-Tn, also known as CD175s) is rarely seen in normal adult tissues, but it is abundantly expressed in many types of human epithelial cancers. We have identified novel antibodies that specifically target with high affinity the STn glycan independent of its carrier protein, affording the potential to recognize a wider array of cancer-specific sialylated proteins. A panel of murine monoclonal anti-STn therapeutic antibodies were generated and their binding specificity and efficacy were characterized in vitro and in in vivo murine cancer models. A subset of these antibodies were conjugated to monomethyl auristatin E (MMAE) to generate antibody-drug conjugates (ADCs). These ADCs demonstrated in vitro efficacy in STn-expressing cell lines and significant tumor growth inhibition in STn-expressing tumor xenograft cancer models with no evidence of overt toxicity.

  5. Evaluation of cell death mechanisms activated by the administration of the theranostics radiopharmaceutical {sup 177}Lu-DOTA-anti-CD20 in a dose range of 1-5 Gy; Evaluacion de los mecanismos de muerte celular activados por la administracion del radiofarmaco teranostico {sup 177}Lu-DOTA-anti-CD20 en un rango de dosis de 1-5 Gy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez V, B. E.

    2016-07-01

    Radio-immunotherapy with anti-CD20 antibodies significantly increases the rate of remission in patients with CD20 over expressing B-cell lymphomas. Radio-labeled antibodies directed to surface antigens allow delivering scaled doses of radiation to specific targets thus limiting the dose to healthy tissue. Anti-CD20 causes cell death by two major pathways; activating the immune system to destroy malignant cells and inducing the activation of cell death pathways. The {sup 177}Lu is a beta particle emitter (max. 0.497 MeV) with a maximum soft tissue reach of 0.7 mm and a half-life of 6.7 days. Several clinical studies have established a maximum tolerated dose (45m Ci/m{sup 2}) for {sup 177}Lu-DOTA-rituximab, which shows a favorable clinical response without hematological toxicity. However, the molecular mechanisms of synergistic activation of anti-CD20 and radionuclide have not been studied. In this work we evaluated by flow cytometry, the activation kinetics of the cell death mechanisms induced by the treatment with {sup 177}Lu-DOTA-anti-CD20 from non-Hod king lymphoma cells (Raji). The absorbed radiation dose delivered to the cell nucleus was calculated by Monte Carlo simulation, considering the contribution of the beta emissions of the radiopharmaceutical present in the cell membrane and surrounding environment, as well as crossfire. This work shows that the application of radiation doses of 1 to 5 Gy of the radiopharmaceutical {sup 177}Lu-DOTA-anti-CD20 are sufficient to induce cell death by apoptosis and arrest of the cell cycle. The combination of these factors (continuous delivery of radiation activation of repair mechanisms and increased radio-sensitivity) causes acute activation of the apoptotic program resulting in significant cell death after 96 h of treatment. The temporal analysis of cell death suggests the early activation of apoptosis that is counteracted by the activation of repair processes caused by sustained irradiation, which leads to cell arrest

  6. Pharmacokinetics and pharmacokinetic/pharmacodynamic associations of ofatumumab, a human monoclonal CD20 antibody, in patients with relapsed or refractory chronic lymphocytic leukaemia: a phase 1-2 study

    DEFF Research Database (Denmark)

    Coiffier, Bertrand; Losic, Nedjad; Rønn, Birgitte Biilmann

    2010-01-01

    The purpose of this phase 1-2 study was to investigate the association between the pharmacokinetic properties of ofatumumab, a human monoclonal CD20 antibody, and outcomes in 33 patients with relapsed/refractory chronic lymphocytic leukaemia receiving 4 weekly infusions of ofatumumab. The ofatumu...

  7. Dosimetric evaluation of anti-CD20 labelled with 188Re

    International Nuclear Information System (INIS)

    Barrio, Graciela; Osso Junior, Joao A.

    2011-01-01

    Radioimmunotherapy has the potential to deliver lethal radiation energy directly to malignant cells via targeting of radioisotope-conjugated monoclonal antibodies (MAbs) to specific antigens. B-cell lymphoma is a particularly good candidate for radioimmunotherapy because the disease is inherently radiosensitive, malignant cells in the blood, bone marrow, spleen and lymphonodes are accessible, and MAbs have been developed to B-cell surface antigens that do not shed or modulate. Rituximab (RTX), the human IgG1-type chimeric form of the parent murine antibody ibritumomab, is specifically targeted against CD20, a surface antigen expressed by pre-B and mature human B lymphocytes. The use of rhenium-188 from a 188 W/ 188 Re generator system represents an attractive alternative radionuclide for therapy. 188 Re is produced from beta decay of the 188 W parent. In addition to the emission of high-energy electrons (Eβ= 2118 keV), 188 Re also decays with emission of a gamma photon with an energy of 155 keV in 15% abundance. Besides the therapeutic usefulness of 188 Re, the emission of gamma photon is an added advantage since the biodistribution of 188 Re-labeled antibodies can be evaluated in vivo with a gamma camera. Also, rhenium has chemical properties similar to technetium. Thus, both can be conjugated to antibodies using similar chemistry methods. The objective of this work is to prove the usefulness of this radiopharmaceutical based on dosimetric studies, that are also required by the Brazilian Regulatory Agency (ANVISA). (author)

  8. Development of an affinity-matured humanized anti-epidermal growth factor receptor antibody for cancer immunotherapy.

    Science.gov (United States)

    Nakanishi, Takeshi; Maru, Takamitsu; Tahara, Kazuhiro; Sanada, Hideaki; Umetsu, Mitsuo; Asano, Ryutaro; Kumagai, Izumi

    2013-02-01

    We showed previously that humanization of 528, a murine anti-epidermal growth factor receptor (EGFR) antibody, causes reduced affinity for its target. Here, to improve the affinity of the humanized antibody for use in cancer immunotherapy, we constructed phage display libraries focused on the complementarity-determining regions (CDRs) of the antibody and carried out affinity selection. Two-step selections using libraries constructed in a stepwise manner enabled a 32-fold affinity enhancement of humanized 528 (h528). Thermodynamic analysis of the interactions between the variable domain fragment of h528 (h528Fv) mutants and the soluble extracellular domain of EGFR indicated that the h528Fv mutants obtained from the first selection showed a large increase in negative enthalpy change due to binding, resulting in affinity enhancement. Furthermore, mutants from the second selection showed a decrease in entropy loss, which led to further affinity maturation. These results suggest that a single mutation in the heavy chain variable domain (i.e. Tyr(52) to Trp) enthalpically contributed for overcoming the energetic barrier to the antigen-antibody interaction, which was a major hurdle for the in vitro affinity maturation of h528. We reported previously that the humanized bispecific diabody hEx3 Db, which targets EGFR and CD3, shows strong anti-tumor activity. hEx3 Db mutants, in which the variable domains of h528 were replaced with those of the affinity-enhanced mutants, were prepared and characterized. In a growth inhibition assay of tumor cells, the hEx3 Db mutants showed stronger anti-tumor activity than that of hEx3 Db, suggesting that affinity enhancement of h528Fv enhances the anti-tumor activity of the bispecific diabody.

  9. CD83 Antibody Inhibits Human B Cell Responses to Antigen as well as Dendritic Cell-Mediated CD4 T Cell Responses.

    Science.gov (United States)

    Wong, Kuan Y; Baron, Rebecca; Seldon, Therese A; Jones, Martina L; Rice, Alison M; Munster, David J

    2018-05-15

    Anti-CD83 Ab capable of Ab-dependent cellular cytotoxicity can deplete activated CD83 + human dendritic cells, thereby inhibiting CD4 T cell-mediated acute graft-versus-host disease. As CD83 is also expressed on the surface of activated B lymphocytes, we hypothesized that anti-CD83 would also inhibit B cell responses to stimulation. We found that anti-CD83 inhibited total IgM and IgG production in vitro by allostimulated human PBMC. Also, Ag-specific Ab responses to immunization of SCID mice xenografted with human PBMC were inhibited by anti-CD83 treatment. This inhibition occurred without depletion of all human B cells because anti-CD83 lysed activated CD83 + B cells by Ab-dependent cellular cytotoxicity and spared resting (CD83 - ) B cells. In cultured human PBMC, anti-CD83 inhibited tetanus toxoid-stimulated B cell proliferation and concomitant dendritic cell-mediated CD4 T cell proliferation and expression of IFN-γ and IL-17A, with minimal losses of B cells (80% of B cells but had no effect on CD4 T cell proliferation and cytokine expression. By virtue of the ability of anti-CD83 to selectively deplete activated, but not resting, B cells and dendritic cells, with the latter reducing CD4 T cell responses, anti-CD83 may be clinically useful in autoimmunity and transplantation. Advantages might include inhibited expansion of autoantigen- or alloantigen-specific B cells and CD4 T cells, thus preventing further production of pathogenic Abs and inflammatory cytokines while preserving protective memory and regulatory cells. Copyright © 2018 by The American Association of Immunologists, Inc.

  10. Distinctive effects of CD34- and CD133-specific antibody-coated stents on re-endothelialization and in-stent restenosis at the early phase of vascular injury

    Science.gov (United States)

    Wu, Xue; Yin, Tieying; Tian, Jie; Tang, Chaojun; Huang, Junli; Zhao, Yinping; Zhang, Xiaojuan; Deng, Xiaoyan; Fan, Yubo; Yu, Donghong; Wang, Guixue

    2015-01-01

    It is not clear what effects of CD34- and CD133-specific antibody-coated stents have on re-endothelialization and in-stent restenosis (ISR) at the early phase of vascular injury. This study aims at determining the capabilities of different coatings on stents (e.g. gelatin, anti-CD133 and anti-CD34 antibodies) to promote adhesion and proliferation of endothelial progenitor cells (EPCs). The in vitro study revealed that the adhesion force enabled the EPCs coated on glass slides to withstand flow-induced shear stress, so that allowing for the growth of the cells on the slides for 48 h. The in vivo experiment using a rabbit model in which the coated stents with different substrates were implanted showed that anti-CD34 and anti-CD133 antibody-coated stents markedly reduced the intima area and restenosis than bare mental stents (BMS) and gelatin-coated stents. Compared with the anti-CD34 antibody-coated stents, the time of cells adhesion was longer and earlier present in the anti-CD133 antibody-coated stents and anti-CD133 antibody-coated stents have superiority in re-endothelialization and inhibition of ISR. In conclusion, this study demonstrated that anti-CD133 antibody as a stent coating for capturing EPCs is better than anti-CD34 antibody in promoting endothelialization and reducing ISR. PMID:26813006

  11. Systemic agonistic anti-CD40 treatment of tumor bearing mice modulates hepatic myeloid suppressive cells and causes immune-mediated liver damage

    Science.gov (United States)

    Medina-Echeverz, José; Ma, Chi; Duffy, Austin; Eggert, Tobias; Hawk, Nga; Kleiner, David E.; Korangy, Firouzeh; Greten, Tim F.

    2015-01-01

    Immune stimulatory monoclonal antibodies are currently evaluated as anti tumor agents. Although overall toxicity appears to be moderate, liver toxicities have been reported and are not completely understood. We studied the effect of systemic CD40 antibody treatment on myeloid cells in spleen and liver. Naïve and tumor-bearing mice were treated systemically with agonistic anti-CD40 antibody. Immune cell subsets in liver and spleen, serum transaminases and liver histologies were analyzed after antibody administration. Nox2−/−, Cd40−/− as well as bone marrow chimeric mice were used to study the mechanism by which agonistic anti-CD40 mediates its effects in vivo. Suppressor function of murine and human tumor-induced myeloid derived suppressive cells was studied upon CD40 ligation. Agonistic CD40 antibody caused liver damage within 24 hours after injection in two unrelated tumor models and mice strains. Using bone marrow chimeras we demonstrated that CD40 antibody-induced hepatitis in tumor-bearing mice was dependent on the presence of CD40-expressing hematopoietic cells. Agonistic CD40 ligation-dependent liver damage was induced by the generation of reactive oxygen species. Furthermore, agonistic CD40 antibody resulted in increased CD80 and CD40 positive liver CD11b+Gr-1+ immature myeloid cells. CD40 ligation on tumor-induced murine and human CD14+HLA-DRlow PBMC from cancer patients reduced their immune suppressor function. Collectively, agonistic CD40 antibody treatment activated tumor-induced, myeloid cells, caused myeloid dependent hepatotoxicity and ameliorated the suppressor function of murine and human MDSC. Collectively, our data suggests that CD40 may mature immunosuppressive myeloid cells and thereby cause liver damage in mice with an accumulation of tumor-induced hepatic MDSC. PMID:25637366

  12. Production of human anti-HLA monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M.C.; Mercier, F.; Roger, J.; Varin, M.

    1986-03-01

    Only 40% of the several hundred anti-HLA murine monoclonal antibodies (MAbs) that have been made detect HLA-A,B,C or DR specificities previously defined by human alloantisera, the range of recognized specificities is very narrow, and few of the MAbs have proven useful as tissue typing reagents. In hopes of obtaining HLA typing reagents, the authors are developing a protocol for the production of human anti-HLA MAbs from HLA-antigen (Ag) immunized peripheral blood B cells of volunteering renal patients, immunized to one or more HLA Ags through therapeutic blood transfusions. A simple enrichment of the donor B cells has not been sufficient for anti-HLA MAb production, the authors are currently delineating the conditions necessary for increasing the number of HLA-specific donor B cells by in vitro stimulation with cells expressing the HLA Ag to which the B cell donor is immunized. For the production of MAbs, the stimulated B cells are transformed with Epstein-Barr virus and subsequently fused with KR-4 lymphoblastoid cells. Hybridomas are selected by HAT and Ouabain. Supernatants are screened for anti-HLA activity against lymphocyte targets expressing the original immunizing HLA Ag by complement mediated /sup 51/Cr release assay. Antibody specificity is determined by the complement-dependent microcytotoxicity test used for HLA typing.

  13. Protection of xenografts by a combination of immunoisolation and a single dose of anti-CD4 antibody.

    Science.gov (United States)

    Mckenzie, A W; Georgiou, H M; Zhan, Y; Brady, J L; Lew, A M

    2001-01-01

    Immunoisolation is the separation of transplanted cells from cells of the immune system using a semipermeable membrane. Using one such immunoisolation capsule-the TheraCyte device-we have assessed the survival of encapsulated xenogeneic tissue in vivo as well as the contribution of CD4+ve T cells to encapsulated xenograft rejection. The foreign body reaction to the TheraCyte capsule in vivo was assessed by transplanting empty capsules into normal mice. These capsules elicit a foreign body response by the host animal. Encapsulated CHO, NIT-1, and PK-15 cells were placed in culture and in immunodeficient mice to investigate their growth characteristics in the TheraCyte device. These cell lines survive both in culture and in immunodeficient SCID mice. Xenogeneic PK cells were also transplanted into normal C57BL/6 mice. These cells do not survive in normal mice despite the absence of direct contact between infiltrating and encapsulated cells. In addition, the survival of encapsulated cells in mice treated with a single dose of anti-CD4 antibody was examined. This was assessed using two systems: 1) histological analysis of capsule sections; 2) a quantitative luciferase reporter system using PK cells transfected to express luciferase. In both cases, anti-CD4 antibody contributed to prolonged encapsulated xenogeneic cell survival. Encapsulated xenogeneic cells survive in immunodeficient mice but not normal mice. Treatment of normal mice with anti-CD4 antibody results in prolonged survival of xenogeneic cells that can be measured using a luciferase reporter system. These results highlight the contribution of CD4+ve T cells to encapsulated xenograft rejection.

  14. Evaluation of the cell death mechanisms activated by the radiopharmaceutical {sup 177}Lu-DOTA-anti-CD20 in a dose range of 1 to 5 Gy; Evaluacion de los mecanismos de muerte celular activados por el radiofarmaco {sup 177}Lu-DOTA-anti-CD20 en un intervalo de dosis de 1 a 5 Gy

    Energy Technology Data Exchange (ETDEWEB)

    Azorin V, E.P.; Rojas C, E. L.; Martinez V, B. E.; Ramos B, J. C.; Jimenez M, N. P.; Ferro F, G., E-mail: erica.azorin@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-10-15

    The radio immunotherapy with anti-CD20 antibodies significantly increases the remission rate of patients with B-cell lymphomas over expressing the CD20. The radiolabeled antibodies directed to surface antigens allow delivering scaled doses of radiation to specific targets thus limiting the dose to healthy tissue. The anti-CD20 causes cell death by two major pathways; activating the immune system to destroy malignant cells and inducing the activation of cell death pathways. The {sup 177}Lu is a beta particle emitter (max. 0.497 MeV) with a maximum reach on soft tissue of 0.7 mm and a half-life of 6.7 days. Several clinical studies have established a maximum tolerated dose (45 m Ci/m{sup 2}) for {sup 177}Lu-DOTA-rituximab, which shows a favorable clinical response without hematological toxicity. However, the molecular mechanisms of action by synergistic effect of anti-CD20 and radionuclide have not been studied. In this work was evaluated; by flow cytometry, the activation kinetics of the cell death mechanisms induced by the treatment with {sup 177}Lu-DOTA-Anti-CD20 in non-Hodgkin (Raji) lymphoma cells. The absorbed radiation dose delivered to the cell nucleus was calculated by Monte Carlo simulation, considering the contribution of the beta emissions of the radiopharmaceutical present in the cell membrane and surrounding environment, as well as crossfire. This work shows that the application of radiation doses of 1 to 5 Gy of the radiopharmaceutical {sup 177}Lu-DOTA-anti-CD20, are sufficient to induce cell death by apoptosis and arrest of the cell cycle. The combination of these factors (continuous delivery of radiation, activation of repair mechanisms and increased radio sensitivity) causes the acute activation of the apoptotic program resulting in significant cell death after 96 h of treatment. The temporal analysis of cell death suggests the early activation of apoptosis that is counteracted by the activation of repair processes caused by sustained irradiation

  15. Oxidized LDL-induced angiogenesis involves sphingosine 1-phosphate: prevention by anti-S1P antibody.

    Science.gov (United States)

    Camaré, Caroline; Trayssac, Magali; Garmy-Susini, Barbara; Mucher, Elodie; Sabbadini, Roger; Salvayre, Robert; Negre-Salvayre, Anne

    2015-01-01

    Neovascularization occurring in atherosclerotic lesions may promote plaque expansion, intraplaque haemorrhage and rupture. Oxidized LDL (oxLDL) are atherogenic, but their angiogenic effect is controversial; both angiogenic and anti-angiogenic effects have been reported. The angiogenic mechanism of oxLDL is partly understood, but the role of the angiogenic sphingolipid, sphingosine 1-phosphate (S1P), in this process is not known. Thus, we investigated whether S1P is involved in the oxLDL-induced angiogenesis and whether an anti-S1P monoclonal antibody can prevent this effect. Angiogenesis was assessed by capillary tube formation by human microvascular endothelial cells (HMEC-1) cultured on Matrigel and in vivo by the Matrigel plug assay in C57BL/6 mice. Human oxLDL exhibited a biphasic angiogenic effect on HMEC-1; low concentrations were angiogenic, higher concentrations were cytotoxic. The angiogenic response to oxLDL was blocked by the sphingosine kinase (SPHK) inhibitor, dimethylsphingosine, by SPHK1-siRNA and by an anti-S1P monoclonal antibody. Moreover, inhibition of oxLDL uptake and subsequent redox signalling by anti-CD36 and anti-LOX-1 receptor antibodies and by N-acetylcysteine, respectively, blocked SPHK1 activation and tube formation. In vivo, in the Matrigel plug assay, low concentrations of human oxLDL or murine oxVLDL also triggered angiogenesis, which was prevented by i.p. injection of the anti-S1P antibody. These data highlight the role of S1P in angiogenesis induced by oxLDL both in HMEC-1 cultured on Matrigel and in vivo in the Matrigel plug model in mice, and demonstrate that the anti-S1P antibody effectively blocks the angiogenic effect of oxLDL. © 2014 The British Pharmacological Society.

  16. Preparation and bioevaluation of {sup 177}Lu-labelled anti-CD44 for radioimmunotherapy of colon cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, So Young; Hong, Young Don; Jung, Sung Hee; Choi, Sun Ju [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    CD44 is a particular adhesion molecule and facilitates both cell-cell and cell-matrix interactions. In particular, splice variants of CD44 are particularly overexpressed in a large number of malignancies and carcinomas. In this study, the {sup 177}Lu-labelled CD44 targeting antibody was prepared and bioevaluated in vitro and in vivo. Anti-CD44 was immunoconjugated with the equivalent molar ratio of cysteine-based dtPA-ncS and radioimmunoconjugated with {sup 177}Lu at room temperature within 15 minutes. the stability was tested in human serum. An in vitro study was carried out in Ht-29 human colon cancer cell lines. For the biodistribution study {sup 177}Lu-labelled anti-CD44 was injected in xenograft mice. Anti-CD44 was immunoconjugated with cysteinebased dtPA-ncS and purified by a centricon filter system having a molecular cut-off of 50 kda. radioimmunoconjugation with {sup 177}Lu was reacted for 15 min at room temperature. the radiolabeling yield was >99%, and it was stable in human serum without any fragmentation or degradation. The radioimmunoconjugate showed a high binding affinity on HT-29 colon cancer cell surfaces. In a biodistribution study, the tumor-to-blood ratio of the radioimmunoconjugate was 43 : 1 at 1 day post injection (p.i) in human colon cancer bearing mice. the anti-CD44 monoclonal antibody for the targeting of colon cancer was effectively radioimmunoconjugated with {sup 177}Lu. the in vitro high immunoactivity of this radioimmunoconjugate was determined by a cell binding assay. In addition, the antibody's tumor targeting ability was demonstrated with very high uptake in tumors. this radioimmunoconjugate is applicable to therapy in human colon cancer with highly expressed CD44.

  17. Co-association of methotrexate and SPIONs into anti-CD64 antibody-conjugated PLGA nanoparticles for theranostic application.

    Science.gov (United States)

    Moura, Catarina Costa; Segundo, Marcela A; Neves, José das; Reis, Salette; Sarmento, Bruno

    2014-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease with severe consequences for the quality of life of sufferers. Regrettably, the inflammatory process involved remains unclear, and finding successful therapies as well as new means for its early diagnosis have proved to be daunting tasks. As macrophages are strongly associated with RA inflammation, effective diagnosis and therapy may encompass the ability to target these cells. In this work, a new approach for targeted therapy and imaging of RA was developed based on the use of multifunctional polymeric nanoparticles. Poly(lactic-co-glycolic acid) nanoparticles were prepared using a single emulsion-evaporation method and comprisaed the co-association of superparamagnetic iron oxide nanoparticles (SPIONs) and methotrexate. The nanoparticles were further functionalized with an antibody against the macrophage-specific receptor, CD64, which is overexpressed at sites of RA. The devised nanoparticles were characterized for mean particle size, polydispersity index, zeta potential, and morphology, as well as the association of SPIONs, methotrexate, and the anti-CD64 antibody. Lastly, the cytotoxicity of the developed nanoparticles was assessed in RAW 264.7 cells using standard MTT and LDH assays. The nanoparticles had a mean diameter in the range of 130-200 nm and zeta potential values ranging from -32 mV to -16 mV. Association with either methotrexate or SPIONs did not significantly affect the properties of the nanoparticles. Conjugation with the anti-CD64 antibody, in turn, caused a slight increase in size and surface charge. Transmission electron microscopy confirmed the association of SPIONs within the poly(lactic-co-glycolic acid) matrix. Both anti-CD64 and methotrexate association were confirmed by Fourier transform infrared spectroscopy, and quantified yielding values as high as 36% and 79%, respectively. In vitro toxicity studies confirmed the methotrexate-loaded nanosystem to be more effective than the free drug

  18. CD133 antibody conjugation to decellularized human heart valves intended for circulating cell capture.

    Science.gov (United States)

    Vossler, John D; Min Ju, Young; Williams, J Koudy; Goldstein, Steven; Hamlin, James; Lee, Sang Jin; Yoo, James J; Atala, Anthony

    2015-09-03

    The long term efficacy of tissue based heart valve grafts may be limited by progressive degeneration characterized by immune mediated inflammation and calcification. To avoid this degeneration, decellularized heart valves with functionalized surfaces capable of rapid in vivo endothelialization have been developed. The aim of this study is to examine the capacity of CD133 antibody-conjugated valve tissue to capture circulating endothelial progenitor cells (EPCs). Decellularized human pulmonary valve tissue was conjugated with CD133 antibody at varying concentrations and exposed to CD133 expressing NTERA-2 cl.D1 (NT2) cells in a microflow chamber. The amount of CD133 antibody conjugated on the valve tissue surface and the number of NT2 cells captured in the presence of shear stress was measured. Both the amount of CD133 antibody conjugated to the valve leaflet surface and the number of adherent NT2 cells increased as the concentration of CD133 antibody present in the surface immobilization procedure increased. The data presented in this study support the hypothesis that the rate of CD133(+) cell adhesion in the presence of shear stress to decellularized heart valve tissue functionalized by CD133 antibody conjugation increases as the quantity of CD133 antibody conjugated to the tissue surface increases.

  19. High-dose myeloablative versus conventional low-dose radioimmunotherapy (RIT) of mantle cell lymphoma (MCL) with the chimeric anti-CD20 antibody C2B8

    International Nuclear Information System (INIS)

    Behr, T.M.; Gotthardt, M.; Schipperm, M.L.; Gratz, S.; Behe, M.P.; Brittinger, G.; Woermann, B.; Becker, W.

    2002-01-01

    CD20 has been used as target molecule for low-dose as well as high-dose, myeloablative RIT of B-cell NHL. MCL is an especially aggressive, prognostically unfavorable form of B-cell NHL. The aim of this study was to investigate whether high-dose, myeloablative RIT with the 131 I-labeled chimeric anti-CD20 antibody C2B8 (rituxan, Mabthera, Roche) may be therapeutically more effective than conventional low-dose therapy in MCL. A total of twelve patients with chemorefractory or relapsed mantle cell lymphoma were studied so far (all of them having relapsed after high-dose chemotherapy, seven of them combined with 12 Gy TBI). A diagnostic-dosimetric study was performed with 10 mCi of 131 I-C2B8 at a protein dose of 2.5 mg/kg. In case of splenic pooling, the protein dose was increased until a more 'favorable' biodistribution was obtained. Therapy was performed with conventional (30-75 mCi; n=4) or myeloablative activities (261-515 mCi; n=8) of 131 I-C2B8 at the previously optimized protein dose, aiming at whole-body doses of ≤ 0.8 Gy (for low-dose RIT) or lung doses of ≤ 27 Gy (for high-dose RIT). Clinical follow-up was obtained for up to 42 months. Overall, in 11 patients the 2.5 mg/kg protein dose was used, whereas in one patient with marked splenomegaly, 10 mg/kg were necessary to overcome the splenic antigenic sink. In the high-dose patients, non-hematologic toxicity was restricted to mild to moderate nausea, fever, transient bilirubin or liver enzyme elevations. Despite thyroid blocking, 6/8 high-dose (in contrast to 0/4 low-dose) patients developed hypothyroidism, requiring thyroxine substitution at 6-18 months after RIT. The response rate in the low-dose arm was only 1(PR)/4, whereas 7/8 high-dose patients experienced complete and the remainder a partial remission. 6 high-dose patients are still in CR (one of them relapsed locally at 3 months, one systemically at 26 months after RIT), and 7 are still alive for up to 42+ months. In contrast to low-dose therapy

  20. An anti-CD34 antibody-functionalized clinical-grade POSS-PCU nanocomposite polymer for cardiovascular stent coating applications: a preliminary assessment of endothelial progenitor cell capture and hemocompatibility.

    Directory of Open Access Journals (Sweden)

    Aaron Tan

    Full Text Available In situ endothelialization of cardiovascular implants has emerged in recent years as an attractive means of targeting the persistent problems of thrombosis and intimal hyperplasia. This study aimed to investigate the efficacy of immobilizing anti-CD34 antibodies onto a POSS-PCU nanocomposite polymer surface to sequester endothelial progenitor cells (EPCs from human blood, and to characterize the surface properties and hemocompatibility of this surface. Amine-functionalized fumed silica was used to covalently conjugate anti-CD34 to the polymer surface. Water contact angle, fluorescence microscopy, and scanning electron microscopy were used for surface characterization. Peripheral blood mononuclear cells (PBMCs were seeded on modified and pristine POSS-PCU polymer films. After 7 days, adhered cells were immunostained for the expression of EPC and endothelial cell markers, and assessed for the formation of EPC colonies. Hemocompatibility was assessed by thromboelastography, and platelet activation and adhesion assays. The number of EPC colonies formed on anti-CD34-coated POSS-PCU surfaces was not significantly higher than that of POSS-PCU (5.0±1.0 vs. 1.7±0.6, p>0.05. However, antibody conjugation significantly improved hemocompatibility, as seen from the prolonged reaction and clotting times, decreased angle and maximum amplitude (p<0.05, as well as decreased platelet adhesion (76.8±7.8 vs. 8.4±0.7, p<0.05 and activation. Here, we demonstrate that POSS-PCU surface immobilized anti-CD34 antibodies selectively captured CD34+ cells from peripheral blood, although only a minority of these were EPCs. Nevertheless, antibody conjugation significantly improves the hemocompatibility of POSS-PCU, and should therefore continue to be explored in combination with other strategies to improve the specificity of EPC capture to promote in situ endothelialization.

  1. Electronic effects in emission of core/shell CdSe/ZnS quantum dots conjugated to anti-Interleukin 10 antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Quintos Vazquez, A.L. [ESIME—Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Torchynska, T.V., E-mail: ttorch@esfm.ipn.mx [ESFM–Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Casas Espinola, J.L. [ESFM–Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Jaramillo Gómez, J.A.; Douda, J. [UPIITA–Instituto Politécnico Nacional, México D. F. 07320, México (Mexico)

    2013-11-15

    The paper presents a comparative study of the photoluminescence (PL) and Raman scattering spectra of the core–shell CdSe/ZnS quantum dots (QDs) in nonconjugated states and after the conjugation to anti-Interleukin 10 antibodies (anti-IL10). All optical measurements are performed on the dried droplets of the original solution of nonconjugated and bioconjugated QDs located on the Si substrate. CdSe/ZnS QDs with emission at 605 and 655 nm have been used. PL spectra of nonconjugated QDs are characterized by one Gaussian shape PL band related to the exciton emission in the CdSe core. PL spectra of bioconjugated QDs have changed essentially: the core PL band shifts into the high energy spectral range (“blue” sift) and becomes asymmetric. Additionally two new PL bands appear. A set of physical reasons has been proposed for the “blue” shift explanation for the core PL band in bioconjugated QDs. Then Raman scattering spectra have been studied with the aim to analyze the impact of elastic strains or the oxidation process at the QD bioconjugation. The variation of PL spectra versus excitation light intensities has been studied to analyze the exciton emission via excited states in QDs. Finally the PL spectrum transformation for the core emission in bioconjugated QDs has been attributed to the electronic quantum confined effects stimulated by the electric charges of bioconjugated antibodies. -- Highlights: • The conjugation of CdSe/ZnS QDs to anti-Interleukin 10 antibodies has been studied. • PL shift to high energy is detected in bioconjugated CdSe/ZnS QDs. • The PL energy shift in bioconjugated QDs is stimulated by antibody electric charges. • The reasons of PL energy shift in bioconjugated QDs have been discussed.

  2. Development of a complete human anti-human transferrin receptor C antibody as a novel marker of oral dysplasia and oral cancer

    International Nuclear Information System (INIS)

    Nagai, Kentaro; Nakahata, Shingo; Shimosaki, Shunsuke; Tamura, Tomohiro; Kondo, Yuudai; Baba, Takashi; Taki, Tomohiko; Taniwaki, Masafumi; Kurosawa, Gene; Sudo, Yukio; Okada, Seiji; Sakoda, Sumio; Morishita, Kazuhiro

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide. Up to 20% of oral dysplasia cases have been suggested to undergo malignant transformation to OSCC; however, there are no methods to predict OSCC development. In this study, to identify the genes associated with oral dysplasia progression, we performed genomic copy number analyses of genomic DNA samples isolated from primary oral dysplasia and OSCC via the microdissection method and found elevated expression of transferrin receptor C (TfR1/TFRC) with genomic amplification in oral dysplasia and OSCC. The expression rate of TFRC in OSCC was significantly higher than that in dysplasia, suggesting that OSCC disease progression might be related to TFRC expression. Additionally, we investigated the in vitro and in vivo impacts of a newly established anti-human TFRC monoclonal antibody, which was isolated from a human cDNA library using the phage-display method, on cell proliferation and survival. The anti-TFRC antibody blocked the interaction between transferrin and TFRC and consequently inhibited iron uptake, leading to the iron deprivation-mediated suppression of cell growth and induction of apoptosis. Moreover, we demonstrated that the anti-TFRC antibody efficiently inhibited tumor growth in a murine xenograft OSCC model. Therefore, we suggest our developed complete human anti-human TFRC antibody as a useful, novel treatment for oral dysplasia and OSCC

  3. Characterization of changes in serum anti-glycan antibodies in Crohn's disease--a longitudinal analysis.

    Directory of Open Access Journals (Sweden)

    Florian Rieder

    Full Text Available INTRODUCTION: Anti-glycan antibodies are a promising tool for differential diagnosis and disease stratification of patients with Crohn's disease (CD. We longitudinally assessed level and status changes of anti-glycan antibodies over time in individual CD patients as well as determinants of this phenomenon. METHODS: 859 serum samples derived from a cohort of 253 inflammatory bowel disease (IBD patients (207 CD, 46 ulcerative colitis (UC were tested for the presence of anti-laminarin (Anti-L, anti-chitin (Anti-C, anti-chitobioside (ACCA, anti-laminaribioside (ALCA, anti-mannobioside (AMCA and anti-Saccharomyces cerevisiae (gASCA antibodies by ELISA. All patients had at least two and up to eleven serum samples taken during the disease course. RESULTS: Median follow-up time for CD was 17.4 months (Interquartile range (IQR 8.0, 31.6 months and for UC 10.9 months (IQR 4.9, 21.0 months. In a subgroup of CD subjects marked changes in the overall immune response (quartile sum score and levels of individual markers were observed over time. The marker status (positive versus negative remained widely stable. Neither clinical phenotype nor NOD2 genotype was associated with the observed fluctuations. In a longitudinal analysis neither changes in disease activity nor CD behavior led to alterations in the levels of the glycan markers. The ability of the panel to discriminate CD from UC or its association with CD phenotypes remained stable during follow-up. In the serum of UC patients neither significant level nor status changes were observed. CONCLUSIONS: While the levels of anti-glycan antibodies fluctuate in a subgroup of CD patients the antibody status is widely stable over time.

  4. A novel antibody-drug conjugate anti-CD19(Fab)-LDM in the treatment of B-cell non-Hodgkin lymphoma xenografts with enhanced anticancer activity.

    Science.gov (United States)

    Jiang, Linlin; Yang, Ming; Zhang, Xiaoyun; Bao, Shiqi; Ma, Li; Fan, Dongmei; Zhou, Yuan; Xiong, Dongsheng; Zhen, Yongsu

    2016-01-01

    Rituximab is widely used in clinical setting for the treatment of B malignant lymphoma and has achieved remarkable success. However, in most patients, the disease ultimately relapses and become resistant to rituximab. To overcome the limitation, there is still a need to find novel strategy for improving therapeutic efficacy. To construct genetically engineered antibody anti-CD19(Fab)-LDM, and verify the anticancer activity targeted toward B-lymphoma. The anticancer activity of anti-CD19(Fab)-LDM in vitro and in vivo was examined. In vitro, the binding activity and internalization of anti-CD19(Fab)-LDP were measured. Using comet assay and apoptosis, the cytotoxicity of energized fusion proteins was observed. From in vivo experiments, targeting of therapeutic effect and anticancer efficacy bythe fusion protein was verified. Data showed that anti-CD19(Fab)-LDM does not only binding the cell surface but is also internalized into the cell. The energized fusion proteins anti-CD19(Fab)-LDM can induce DNA damage. Furthermore, significant in vivo therapeutic efficacy was observed. The present study demonstrated that the genetically engineered antibody anti-CD19(Fab)-LDM exhibited enhanced cytotoxicity compared to LDM alone. One of the most powerful advantages of anti-CD19(Fab)-LDM, however, is that it can be internalized within the cells and carry out cytotoxic effects. Therefore, anti-CD19(Fab)-LDM may be as a useful targeted therapy for B-cell lymphoma.

  5. Therapeutic effects of anti-CD115 monoclonal antibody in mouse cancer models through dual inhibition of tumor-associated macrophages and osteoclasts.

    Directory of Open Access Journals (Sweden)

    Laetitia Fend

    Full Text Available Tumor progression is promoted by Tumor-Associated Macrophages (TAMs and metastasis-induced bone destruction by osteoclasts. Both myeloid cell types depend on the CD115-CSF-1 pathway for their differentiation and function. We used 3 different mouse cancer models to study the effects of targeting cancer host myeloid cells with a monoclonal antibody (mAb capable of blocking CSF-1 binding to murine CD115. In mice bearing sub-cutaneous EL4 tumors, which are CD115-negative, the anti-CD115 mAb depleted F4/80(+ CD163(+ M2-type TAMs and reduced tumor growth, resulting in prolonged survival. In the MMTV-PyMT mouse model, the spontaneous appearance of palpable mammary tumors was delayed when the anti-CD115 mAb was administered before malignant transition and tumors became palpable only after termination of the immunotherapy. When administered to mice already bearing established PyMT tumors, anti-CD115 treatment prolonged their survival and potentiated the effect of chemotherapy with Paclitaxel. As shown by immunohistochemistry, this therapeutic effect correlated with the depletion of F4/80(+CD163(+ M2-polarized TAMs. In a breast cancer model of bone metastasis, the anti-CD115 mAb potently blocked the differentiation of osteoclasts and their bone destruction activity. This resulted in the inhibition of cancer-induced weight loss. CD115 thus represents a promising target for cancer immunotherapy, since a specific blocking antibody may not only inhibit the growth of a primary tumor through TAM depletion, but also metastasis-induced bone destruction through osteoclast inhibition.

  6. Establishment of CMab-43, a Sensitive and Specific Anti-CD133 Monoclonal Antibody, for Immunohistochemistry.

    Science.gov (United States)

    Itai, Shunsuke; Fujii, Yuki; Nakamura, Takuro; Chang, Yao-Wen; Yanaka, Miyuki; Saidoh, Noriko; Handa, Saori; Suzuki, Hiroyoshi; Harada, Hiroyuki; Yamada, Shinji; Kaneko, Mika K; Kato, Yukinari

    2017-10-01

    CD133, also known as prominin-1, was first described as a cell surface marker on early progenitor and hematopoietic stem cells. It is a five-domain transmembrane protein composed of an N-terminal extracellular tail, two small cytoplasmic loops, two large extracellular loops containing seven potential glycosylation sites, and a short C-terminal intracellular tail. CD133 has been used as a marker to identify cancer stem cells derived from primary solid tumors and as a prognostic marker of gliomas. Herein, we developed novel anti-CD133 monoclonal antibodies (mAbs) and characterized their efficacy in flow cytometry, Western blot, and immunohistochemical analyses. We expressed the full length of CD133 in LN229 glioblastoma cells, immunized mice with LN229/CD133 cells, and performed the first screening using flow cytometry. After limiting dilution, we established 100 anti-CD133 mAbs, reacting with LN229/CD133 cells but not with LN229 cells. Subsequently, we performed the second and third screening with Western blot and immunohistochemical analyses, respectively. Among 100 mAbs, 11 strongly reacted with CD133 in Western blot analysis. One of 11 clones, CMab-43 (IgG 2a , kappa), showed a sensitive and specific reaction against colon cancer cells, warranting the use of CMab-43 in detecting CD133 in pathological analyses of CD133-expressing cancers.

  7. Dosimetric evaluation of anti-CD20 labelled with {sup 188}Re

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, Graciela; Osso Junior, Joao A., E-mail: gracielabarrio@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Radioimmunotherapy has the potential to deliver lethal radiation energy directly to malignant cells via targeting of radioisotope-conjugated monoclonal antibodies (MAbs) to specific antigens. B-cell lymphoma is a particularly good candidate for radioimmunotherapy because the disease is inherently radiosensitive, malignant cells in the blood, bone marrow, spleen and lymphonodes are accessible, and MAbs have been developed to B-cell surface antigens that do not shed or modulate. Rituximab (RTX), the human IgG1-type chimeric form of the parent murine antibody ibritumomab, is specifically targeted against CD20, a surface antigen expressed by pre-B and mature human B lymphocytes. The use of rhenium-188 from a {sup 188}W/{sup 188}Re generator system represents an attractive alternative radionuclide for therapy. {sup 188}Re is produced from beta decay of the {sup 188}W parent. In addition to the emission of high-energy electrons (E{beta}= 2118 keV), {sup 188}Re also decays with emission of a gamma photon with an energy of 155 keV in 15% abundance. Besides the therapeutic usefulness of {sup 188}Re, the emission of gamma photon is an added advantage since the biodistribution of {sup 188}Re-labeled antibodies can be evaluated in vivo with a gamma camera. Also, rhenium has chemical properties similar to technetium. Thus, both can be conjugated to antibodies using similar chemistry methods. The objective of this work is to prove the usefulness of this radiopharmaceutical based on dosimetric studies, that are also required by the Brazilian Regulatory Agency (ANVISA). (author)

  8. CD20-based Immunotherapy of B-cell Derived Hematologic Malignancies.

    Science.gov (United States)

    Shanehbandi, Dariush; Majidi, Jafar; Kazemi, Tohid; Baradaran, Behzad; Aghebati-Maleki, Leili

    2017-01-01

    CD20 is a surface antigen, which is expressed at certain stages of B-cell differentiation. Targeting the CD20-positive B-cells with therapeutic monoclonal antibodies (MAbs) has been an effectual strategy in the treatment of hematologic malignancies such as non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Initial success with Rituximab (RTX) has encouraged the creation and development of more effective CD20 based therapeutics. However, treatment with conventional MAbs has not been adequate to overcome the problems such as refractory/ relapsed disease. In this regard, new generations of MAbs with enhanced affinity or improved anti-tumor properties have been developed. CD20 directed therapeutics have heterogeneous features and mechanisms of action. Hence, having sufficient knowledge on the immunological and molecular aspects of CD20 based cancer therapy is necessary for predicting the clinical outcomes and taking the necessary measures. An extensive search was performed in PubMed and similar databases for peer-reviewed articles concerning the biology, function and characteristics of CD20 molecule as well as the mechanisms of action and evolutionary process of CD20 targeting agents. This review provides information about the current situation of CD20 targeting immunotherapeutics including MAbs, bispecific antibodies (which exert multiple functions or involve Tcells in tumor elimination) and CAR T-cells (engineered T-cells armed with chimeric antigen receptors). Moreover, limitations, challenges and available solutions regarding the application of CD20 targeting treatments are addressed. Utilization of CD20-targeted therapeutics, due to their diverse properties, requires special considerations. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. CD44 antibodies and immune thrombocytopenia in the amelioration of murine inflammatory arthritis.

    Directory of Open Access Journals (Sweden)

    Patrick J Mott

    Full Text Available Antibodies to CD44 have been used to successfully ameliorate murine models of autoimmune disease. The most often studied disease model has been murine inflammatory arthritis, where a clear mechanism for the efficacy of CD44 antibodies has not been established. We have recently shown in a murine passive-model of the autoimmune disease immune thrombocytopenia (ITP that some CD44 antibodies themselves can induce thrombocytopenia in mice, and the CD44 antibody causing the most severe thrombocytopenia (IM7, also is known to be highly effective in ameliorating murine models of arthritis. Recent work in the K/BxN serum-induced model of arthritis demonstrated that antibody-induced thrombocytopenia reduced arthritis, causing us to question whether CD44 antibodies might primarily ameliorate arthritis through their thrombocytopenic effect. We evaluated IM7, IRAWB14.4, 5035-41.1D, KM201, KM114, and KM81, and found that while all could induce thrombocytopenia, the degree of protection against serum-induced arthritis was not closely related to the length or severity of the thrombocytopenia. CD44 antibody treatment was also able to reverse established inflammation, while thrombocytopenia induced by an anti-platelet antibody targeting the GPIIbIIIa platelet antigen, could not mediate this effect. While CD44 antibody-induced thrombocytopenia may contribute to some of its therapeutic effect against the initiation of arthritis, for established disease there are likely other mechanisms contributing to its efficacy. Humans are not known to express CD44 on platelets, and are therefore unlikely to develop thrombocytopenia after CD44 antibody treatment. An understanding of the relationship between arthritis, thrombocytopenia, and CD44 antibody treatment remains critical for continued development of CD44 antibody therapeutics.

  10. A role for CD4+ but not CD8+ T cells in immunity to Schistosoma mansoni induced by 20 krad-irradiated and Ro 11-3128-terminated infections

    International Nuclear Information System (INIS)

    Vignali, D.A.A.; Bickle, Q.D.; Taylor, M.G.; Crocker, P.; Cobbold, S.; Waldmann, H

    1989-01-01

    The role of CD4 + (L3/T4 + ) and CD8 + (Lyt-2 + ) T cells in immunity to Schistosoma mansoni induced by 20 krad-irradiated and Ro 11-terminated infections in mice was investigated directly by in vivo depletion of these subsets with cytotoxic rat monoclonal antibodies (mAb). Effective physical depletion was demonstrated by flow cytometric analysis and immunohistochemical staining. Functional depletion of helper activity following anti-CD4 treatment was indicated by an abrogation of concanavalin A(Con A)-induced colony-stimulating factor (CSF) release, while anti-CD8 treatment had no effect in these assays. Pre-existing S. mansoni-specific antibody levels were unaffected by anti-CD4 and anti-CD8 treatment. In vivo depletion of CD4 + T cells resulted in a dramatic reduction in immunity induced by one (up to 100%) and two (up to 70%) vaccinations with 20 krad-irradiated cercariae and also of resistance induced by Ro 11-attenuated infections (up to 100%). Depletion of CD8 + T cells had no effect on resistance induced by any of the vaccination protocols investigated. A correlation was observed between resistance and T cell-induced, macrophage-mediated killing of schistosomula in vitro, both of which were abrogated following anti-CD4 treatment but were unaffected by CD8 + T-cell depletion. The possible role of CD4 + T cells in vivo and the implications for vaccine development are discussed. (author)

  11. Imatinib treatment induces CD5+ B lymphocytes and IgM natural antibodies with anti-leukemic reactivity in patients with chronic myelogenous leukemia.

    Directory of Open Access Journals (Sweden)

    Silvia Catellani

    Full Text Available Imatinib mesylate is a first line treatment of Chronic Myelogenous Leukemia and of a rare form of gastrointestinal stromal cancer, where the response to the drug is also linked to the immune system activation with production of antineoplastic cytokines. In this study, forty patients in the chronic phase of disease, treated with imatinib mesylate, were analyzed. Bone marrow aspirates were drawn at diagnosis, after 3, 6, 12, 18 months for haematological, cytofluorimetric, cytogenetic, biomolecular evaluation and cytokine measurement. Responder and non responder patients were defined according to the European LeukemiaNet recommendations. In responder patients (n = 32, the percentage of bone marrow CD20(+CD5(+sIgM(+ lymphocytes, and the plasma levels of IgM, were significantly higher, at 3 months and up to 9 months, than in non responders. These IgM reacted with O-linked sugars expressed by leukemic cells and could induce tumor cell apoptosis. In responder patients the stromal-derived factor-1 and the B-lymphocyte-activating factor of the tumor necrosis factor family significantly raised in the bone marrow after imatinib administration, together with the bone morphogenetic proteins-2 and -7. All patients with high number of CD20(+CD5(+sIgM(+ cells and high stromal-derived factor-1 and B lymphocyte activating factor levels, underwent complete cytogenetic and/or molecular remission by 12 months. We propose that CD20(+CD5(+sIgM(+ lymphocytes producing anti-carbohydrate antibodies with anti-tumor activity, might contribute to the response to imatinib treatment. As in multivariate analysis bone marrow CD20(+CD5(+sIgM(+ cells and stromal-derived factor-1 and B-lymphocyte-activating factor levels were significantly related to cytogenetical and molecular changes, they might contribute to the definition of the pharmacological response.

  12. 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....

  13. Radiolabeling of anti-CD20 with Re-188 for treatment of non-Hodgkin's lymphoma: radiochemical control

    International Nuclear Information System (INIS)

    Dias, Carla R.; Osso Junior, Joao A.

    2009-01-01

    The development of tumor-selective radiopharmaceuticals is clinically desirable as a means of detecting or confirming the presence and location of primary and metastatic lesions and monitoring tumor response to (chemo)therapy. In addition, the application of targeted radiotherapeutics provides a unique and effective modality for direct tumor treatment. In this manner the radioimmunotherapy (RIT) uses the targeting features of monoclonal antibody to deliver radiation from an attached radionuclide. Antibody therapy directed against the CD20 antigen on the surface of B-cells is considered one of the first successful target-specific therapies in oncology. The radionuclide rhenium-188 ( 188 Re) is currently produced from the father nuclide tungsten-188 ( 188 W) through a transportable generator system. Because of its easy availability and suitable nuclear properties (EβMAX = 2.1 MeV, t 1/2 = 16.9 h, Eγ = 155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agent and could be conveniently utilized for imaging and dosimetric purposes. The purpose of this work is to show the radiochemical control of the optimized formulation (solution) and lyophilized formulation (kit) of labeled rituximab (anti-CD20) with 188 Re. Rituximab was reduced by incubation with 2-mercaptoethanol at room temperature. The number of resulting free sulfhydryl groups was assayed with Ellman's reagent. Radiochemical purity of 188 Re-rituximab was evaluated using instant thin layer chromatography-silica gel (ITLC-SG). Quality control methods for evaluation of radiochemical purity showed good labeling yield of the antibody. (author)

  14. Function-blocking antibodies to human vascular adhesion protein-1: a potential anti-inflammatory therapy.

    Science.gov (United States)

    Kirton, Christopher M; Laukkanen, Marja-Leena; Nieminen, Antti; Merinen, Marika; Stolen, Craig M; Armour, Kathryn; Smith, David J; Salmi, Marko; Jalkanen, Sirpa; Clark, Michael R

    2005-11-01

    Human vascular adhesion protein-1 (VAP-1) is a homodimeric 170-kDa sialoglycoprotein that is expressed on the surface of endothelial cells and functions as a semicarbazide-sensitive amine oxidase and as an adhesion molecule. Blockade of VAP-1 has been shown to reduce leukocyte adhesion and transmigration in in vivo and in vitro models, suggesting that VAP-1 is a potential target for anti-inflammatory therapy. In this study we have constructed mouse-human chimeric antibodies by genetic engineering in order to circumvent the potential problems involved in using murine antibodies in man. Our chimeric anti-VAP-1 antibodies, which were designed to lack Fc-dependent effector functions, bound specifically to cell surface-expressed recombinant human VAP-1 and recognized VAP-1 in different cell types in tonsil. Furthermore, the chimeric antibodies prevented leukocyte adhesion and transmigration in vitro and in vivo. Hence, these chimeric antibodies have the potential to be used as a new anti-inflammatory therapy.

  15. Comparison of an anti-rabies human monoclonal antibody combination with human polyclonal anti-rabies immune globulin

    NARCIS (Netherlands)

    Goudsmit, Jaap; Marissen, Wilfred E.; Weldon, William C.; Niezgoda, Michael; Hanlon, Cathleen A.; Rice, Amy B.; Kruif, John de; Dietzschold, Bernhard; Bakker, Alexander B. H.; Rupprecht, Charles E.

    2006-01-01

    The World Health Organization estimates human mortality from endemic canine rabies to be 55,000 deaths/year. Limited supply hampers the accessibility of appropriate lifesaving treatment, particularly in areas where rabies is endemic. Anti-rabies antibodies are key to protection against lethal

  16. Follow-up of relapsed B-cell lymphoma patients treated with iodine-131-labeled anti-CD20 antibody and autologous stem-cell rescue

    International Nuclear Information System (INIS)

    Liu, S Y.; Eary, Janet F.; Petersdorf, S H.; Martin, P J.; Maloney, D G.; Applebaum, F. R.; Matthews, D. C.; Bush, S A.; Durack, L. D.; Fisher, Darrell R.; Gooley, T A.; Bernstein, I. D.; Press, O. W.

    1997-01-01

    Radioimmunotherapy (RIT) is a promising treatment approach for B-cell lymphomas. This is our first opportunity to report long-term follow-up data and late toxicities in 29 patients treated with myeloablative doses of iodine-131-anti-CD20 antibody (anti-B1) and autologous stem-cell rescue. PATIENTS AND METHODS: Trace-labeled biodistribution studies first determined the ability to deliver higher absorbed radiation doses to tumor sites than to lung, liver, or kidney at varying amounts of anti-B1 protein (0.35, 1.7, or 7 mg/kg). Twenty- nine patients received therapeutic infusions of single-agent (131)I- anti-B1, given at the protein dose found optimal in the biodistribution study, labeled with amounts of (131)I (280 to 785 mCi[10.4 to 29.0 GBq]) calculated to deliver specific absorbed radiation doses to the normal organs, followed by autologous stem-cell support. RESULTS: Major responses occurred in 25 patients (86%), with 23 complete responses (CRs; 79%). The nonhematopoietic do se-limiting toxicity was reversible cardiopulmonary insufficiency, which occurred in two patients at RIT doses that delivered > or = 27 Gy to the lungs. With a median follow-up time of 42 months, the estimated overall and progression-free survival rates are 68% and 42%, respectively. Currently, 14 of 29 patients remain in unmaintained remissions that range from 27+ to 87+ months after RIT. Late toxicities have been uncommon except for elevated thyroid-stimulating hormone (TSH) levels found in approximately 60% of the subjects. Two patients developed second malignancies, but none have developed myelodysplasia (MDS). CONCLUSION: Myeloablative (131)I-anti- B1 RIT is relatively well tolerated when given with autologous stem- cell support and often results in prolonged remission durations with few late toxicities

  17. Modulation of Cytokine Production by Drugs with Antiepileptic or Mood Stabilizer Properties in Anti-CD3- and Anti-CD40-Stimulated Blood In Vitro

    Directory of Open Access Journals (Sweden)

    Hubertus Himmerich

    2014-01-01

    Full Text Available Increased cytokine production possibly due to oxidative stress has repeatedly been shown to play a pivotal role in the pathophysiology of epilepsy and bipolar disorder. Recent in vitro and animal studies of valproic acid (VPA report antioxidative and anti-inflammatory properties, and suppression of interleukin (IL-6 and tumor necrosis factor (TNF-α. We tested the effect of drugs with antiepileptic or mood stabilizer properties, namely, primidone (PRM, carbamazepine (CBZ, levetiracetam (LEV, lamotrigine (LTG, VPA, oxcarbazepine (OXC, topiramate (TPM, phenobarbital (PB, and lithium on the production of the following cytokines in vitro: interleukin (IL-1β, IL-2, IL-4, IL-6, IL-17, IL-22, and TNF-α. We performed a whole blood assay with stimulated blood of 14 healthy female subjects. Anti-human CD3 monoclonal antibody OKT3, combined with 5C3 antibody against CD40, was used as stimulant. We found a significant reduction of IL-1 and IL-2 levels with all tested drugs other than lithium in the CD3/5C3-stimulated blood; VPA led to a decrease in IL-1β, IL-2, IL-4, IL-6, IL-17, and TNF-α production, which substantiates and adds knowledge to current hypotheses on VPA’s anti-inflammatory properties.

  18. The challenge of treating hepatitis C virus-associated cryoglobulinemic vasculitis in the era of anti-CD20 monoclonal antibodies and direct antiviral agents.

    Science.gov (United States)

    Roccatello, Dario; Sciascia, Savino; Rossi, Daniela; Solfietti, Laura; Fenoglio, Roberta; Menegatti, Elisa; Baldovino, Simone

    2017-06-20

    Mixed cryoglobulinemia syndrome (MC) is a systemic vasculitis involving kidneys, joints, skin, and peripheral nerves. While many autoimmune, lymphoproliferative, and neoplastic disorders have been associated with this disorder, hepatitis C virus (HCV) is known to be the etiologic agent in the majority of patients. Therefore, clinical research has focused on anti-viral drugs and, more recently, on the new, highly potent Direct-acting Antiviral Agents (DAAs). These drugs assure sustained virologic response (SVR) rates >90%. Nevertheless, data on their efficacy in patients with HCV-associated cryoglobulinemic vasculitis are disappointing, possibly due to the inability of the drugs to suppress the immune-mediated process once it has been triggered.Despite the potential risk of exacerbation of the infection, immunosuppression has traditionally been regarded as the first-line intervention in cryoglobulinemic vasculitis, especially if renal involvement is severe. Biologic agents have raised hopes for more manageable therapeutic approaches, and Rituximab (RTX), an anti CD20 monoclonal antibody, is the most widely used biologic drug. It has proved to be safer than conventional immunosuppressants, thus substantially changing the natural history of HCV-associated cryoglobulinemic vasculitis by providing long-term remission, especially with intensive regimens.The present review focuses on the new therapeutic opportunities offered by the combination of biological drugs, mainly Rituximab, with DAAs.

  19. Evaluation of cell death mechanisms activated by the administration of the theranostics radiopharmaceutical "1"7"7Lu-DOTA-anti-CD20 in a dose range of 1-5 Gy

    International Nuclear Information System (INIS)

    Martinez V, B. E.

    2016-01-01

    Radio-immunotherapy with anti-CD20 antibodies significantly increases the rate of remission in patients with CD20 over expressing B-cell lymphomas. Radio-labeled antibodies directed to surface antigens allow delivering scaled doses of radiation to specific targets thus limiting the dose to healthy tissue. Anti-CD20 causes cell death by two major pathways; activating the immune system to destroy malignant cells and inducing the activation of cell death pathways. The "1"7"7Lu is a beta particle emitter (max. 0.497 MeV) with a maximum soft tissue reach of 0.7 mm and a half-life of 6.7 days. Several clinical studies have established a maximum tolerated dose (45m Ci/m"2) for "1"7"7Lu-DOTA-rituximab, which shows a favorable clinical response without hematological toxicity. However, the molecular mechanisms of synergistic activation of anti-CD20 and radionuclide have not been studied. In this work we evaluated by flow cytometry, the activation kinetics of the cell death mechanisms induced by the treatment with "1"7"7Lu-DOTA-anti-CD20 from non-Hod king lymphoma cells (Raji). The absorbed radiation dose delivered to the cell nucleus was calculated by Monte Carlo simulation, considering the contribution of the beta emissions of the radiopharmaceutical present in the cell membrane and surrounding environment, as well as crossfire. This work shows that the application of radiation doses of 1 to 5 Gy of the radiopharmaceutical "1"7"7Lu-DOTA-anti-CD20 are sufficient to induce cell death by apoptosis and arrest of the cell cycle. The combination of these factors (continuous delivery of radiation activation of repair mechanisms and increased radio-sensitivity) causes acute activation of the apoptotic program resulting in significant cell death after 96 h of treatment. The temporal analysis of cell death suggests the early activation of apoptosis that is counteracted by the activation of repair processes caused by sustained irradiation, which leads to cell arrest and increases

  20. Flow Cytometry Assessment of In Vitro Generated CD138+ Human Plasma Cells

    Directory of Open Access Journals (Sweden)

    Rayelle Itoua Maïga

    2014-01-01

    Full Text Available The in vitro CD40-CD154 interaction promotes human B lymphocytes differentiation into plasma cells. Currently, CD138 is the hallmark marker enabling the detection of human plasma cells, both in vitro and in vivo; its presence can be monitored by flow cytometry using a specific antibody. We have developed a culture system allowing for the differentiation of memory B lymphocytes. In order to detect the newly formed plasma cells, we have compared their staining using five anti-CD138 monoclonal antibodies (mAbs. As a reference, we also tested human cell lines, peripheral blood mononuclear cells, and bone marrow samples. The five anti-CD138 mAbs stained RPMI-8226 cells (>98% with variable stain index (SI. The highest SI was obtained with B-A38 mAb while the lowest SI was obtained with DL-101 and 1D4 mAbs. However, the anti-CD138 mAbs were not showing equivalent CD138+ cells frequencies within the generated plasma cells. B-A38, B-B4, and MI-15 were similar (15–25% while DL-101 mAb stained a higher proportion of CD138-positive cells (38–42%. DL-101 and B-A38 mAbs stained similar populations in bone marrow samples but differed in their capacity to bind to CD138high and CD138lo cell lines. In conclusion, such cellular fluctuations suggest heterogeneity in human plasma cell populations and/or in CD138 molecules.

  1. ADCC employing an NK cell line (haNK) expressing the high affinity CD16 allele with avelumab, an anti-PD-L1 antibody.

    Science.gov (United States)

    Jochems, Caroline; Hodge, James W; Fantini, Massimo; Tsang, Kwong Y; Vandeveer, Amanda J; Gulley, James L; Schlom, Jeffrey

    2017-08-01

    NK-92 cells, and their derivative, designated aNK, were obtained from a patient with non-Hodgkin lymphoma. Prior clinical studies employing adoptively transferred irradiated aNK cells have provided evidence of clinical benefit and an acceptable safety profile. aNK cells have now been engineered to express IL-2 and the high affinity (ha) CD16 allele (designated haNK). Avelumab is a human IgG1 anti-PD-L1 monoclonal antibody, which has shown evidence of clinical activity in a range of human tumors. Prior in vitro studies have shown that avelumab has the ability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) of human tumor cells when combined with NK cells. In the studies reported here, the ability of avelumab to enhance the lysis of a range of human carcinoma cells by irradiated haNK cells via the ADCC mechanism is demonstrated; this ADCC is shown to be inhibited by anti-CD16 blocking antibody and by concanamycin A, indicating the use of the granzyme/perforin pathway in tumor cell lysis. Studies also show that while NK cells have the ability to lyse aNK or haNK cells, the addition of NK cells to irradiated haNK cells does not inhibit haNK-mediated lysis of human tumor cells, with or without the addition of avelumab. Avelumab-mediated lysis of tumor cells by irradiated haNK cells is also shown to be similar to that of NK cells bearing the V/V Fc receptor high affinity allele. These studies thus provide the rationale for the clinical evaluation of the combined use of avelumab with that of irradiated adoptively transferred haNK cells. © 2017 UICC.

  2. Targeting Tumor Cells with Anti-CD44 Antibody Triggers Macrophage-Mediated Immune Modulatory Effects in a Cancer Xenograft Model.

    Science.gov (United States)

    Maisel, Daniela; Birzele, Fabian; Voss, Edgar; Nopora, Adam; Bader, Sabine; Friess, Thomas; Goller, Bernhard; Laifenfeld, Daphna; Weigand, Stefan; Runza, Valeria

    2016-01-01

    CD44, a transmembrane receptor reported to be involved in various cellular functions, is overexpressed in several cancer types and supposed to be involved in the initiation, progression and prognosis of these cancers. Since the sequence of events following the blockage of the CD44-HA interaction has not yet been studied in detail, we profiled xenograft tumors by RNA Sequencing to elucidate the mode of action of the anti-CD44 antibody RG7356. Analysis of tumor and host gene-expression profiles led us to the hypothesis that treatment with RG7356 antibody leads to an activation of the immune system. Using cytokine measurements we further show that this activation involves the secretion of chemo-attractants necessary for the recruitment of immune cells (i.e. macrophages) to the tumor site. We finally provide evidence for antibody-dependent cellular phagocytosis (ADCP) of the malignant cells by macrophages.

  3. Targeting Tumor Cells with Anti-CD44 Antibody Triggers Macrophage-Mediated Immune Modulatory Effects in a Cancer Xenograft Model.

    Directory of Open Access Journals (Sweden)

    Daniela Maisel

    Full Text Available CD44, a transmembrane receptor reported to be involved in various cellular functions, is overexpressed in several cancer types and supposed to be involved in the initiation, progression and prognosis of these cancers. Since the sequence of events following the blockage of the CD44-HA interaction has not yet been studied in detail, we profiled xenograft tumors by RNA Sequencing to elucidate the mode of action of the anti-CD44 antibody RG7356. Analysis of tumor and host gene-expression profiles led us to the hypothesis that treatment with RG7356 antibody leads to an activation of the immune system. Using cytokine measurements we further show that this activation involves the secretion of chemo-attractants necessary for the recruitment of immune cells (i.e. macrophages to the tumor site. We finally provide evidence for antibody-dependent cellular phagocytosis (ADCP of the malignant cells by macrophages.

  4. Biodistribution and pharmacokinetics of monoclonal antibody T1h and variant anti-CD6 murine 10D12 in healthy animals and in experimental arthritis model

    International Nuclear Information System (INIS)

    León, M; Hernández, I; Aldana, L; Ayra, F; Castro, Y; Leyva, R; García, L; Pérez, S.; Casaco, A.

    2016-01-01

    Biodistribution and pharmacokinetic of two radio labeled monoclonal antibodies was performed with the help of imaging techniques. Isotopic labeling was carried out by means of standardized methods. Pharmacokinetic evaluation was performed using the population approach and sparse data design. Introduction: Targeted therapy with monoclonal antibodies (MAb) is an efficient option for the treatment of rheumatoid arthritis. Th1 is a MAb anti human CD6 developed for the treatment of autoimmune disease and 10D12 is its counterpart anti murine CD6 developed as a pharmacological tool to get deep into the response mechanisms in animals models of rheumatoid arthritis.To investigate the behavior of both antibodies in the assay system, molecules were labeled with 125I to evaluate pharmacokinetic in healthy animals and with 99mTc to evaluate the antibody uptake in inflamed area of induced arthritis. Materials and methods: Antibodies were supplied by the Center of Molecular immunology. Iodination was performed by the iodogen method and technetium labeling was carried out directly by Schwarz method. Female C57BL6 from CENPALAB were used for experiments. Biodistribution and pharmacokinetic was performed by a sparse data design using the population approach. Uptake in region of inflammation was quantified by gammagraphy at the same time points of blood sampling. A compartmental model was build to quantify uptake kinetic. Pharmacokinetic profiles were analyzed using MONOLIX software version 4.2. Results: Minor pharmacokinetic differences were found between monoclonal antibodies labeled with 125I and 99mTc. As a humanized antibody, T1h shows a faster clearance than 10D12 and a biodistribution pattern reflecting preference for excretion mechanisms. The arthritis accumulation was not consistent with a targeted mediated uptake. On the other hand, radio labeled 10D12 shows an accumulation profile in arthritis with two peaks of maximum concentration representing an initial transit to

  5. A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis.

    Science.gov (United States)

    Agrawal, Smriti M; Silva, Claudia; Wang, Janet; Tong, Jade Pui-Wai; Yong, V Wee

    2012-04-05

    Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin) is an inducer of the expression of several matrix metalloproteinases (MMPs). We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). To improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies. Of these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9) production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control. We have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS.

  6. A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Agrawal Smriti M

    2012-04-01

    Full Text Available Abstract Background Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin is an inducer of the expression of several matrix metalloproteinases (MMPs. We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS, experimental autoimmune encephalomyelitis (EAE. Methods To improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies. Results Of these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9 production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control. Conclusions We have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS.

  7. Analyses of the peripheral immunome following multiple administrations of avelumab, a human IgG1 anti-PD-L1 monoclonal antibody.

    Science.gov (United States)

    Donahue, Renee N; Lepone, Lauren M; Grenga, Italia; Jochems, Caroline; Fantini, Massimo; Madan, Ravi A; Heery, Christopher R; Gulley, James L; Schlom, Jeffrey

    2017-01-01

    Multiple anti-PD-L1/PD-1 checkpoint monoclonal antibodies (MAb) have shown clear evidence of clinical benefit. All except one have been designed or engineered to omit the possibility to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) as a second potential mode of anti-tumor activity; the reason for this is the concern of lysis of PD-L1 positive immune cells. Avelumab is a fully human IgG1 MAb which has been shown in prior in vitro studies to mediate ADCC versus a range of human tumor cells, and clinical studies have demonstrated anti-tumor activity versus a range of human cancers. This study was designed to investigate the effect on immune cell subsets in the peripheral blood of cancer patients prior to and following multiple administrations of avelumab. One hundred twenty-three distinct immune cell subsets in the peripheral blood of cancer patients ( n  = 28) in a phase I trial were analyzed by flow cytometry prior to and following one, three, and nine cycles of avelumab. Changes in soluble (s) CD27 and sCD40L in plasma were also evaluated. In vitro studies were also performed to determine if avelumab would mediate ADCC of PBMC. No statistically significant changes in any of the 123 immune cell subsets analyzed were observed at any dose level, or number of doses, of avelumab. Increases in the ratio of sCD27:sCD40L were observed, suggesting potential immune activation. Controlled in vitro studies also showed lysis of tumor cells by avelumab versus no lysis of PBMC from five donors. These studies demonstrate the lack of any significant effect on multiple immune cell subsets, even those expressing PD-L1, following multiple cycles of avelumab. These results complement prior studies showing anti-tumor effects of avelumab and comparable levels of adverse events with avelumab versus other anti-PD-1/PD-L1 MAbs. These studies provide the rationale to further exploit the potential ADCC mechanism of action of avelumab as well as other human IgG1 checkpoint

  8. The CARD8 p.C10X mutation associates with a low anti-glycans antibody response in patients with Crohn's disease.

    Science.gov (United States)

    Vasseur, Francis; Sendid, Boualem; Broly, Franck; Gower-Rousseau, Corinne; Sarazin, Aurore; Standaert-Vitse, Annie; Colombel, Jean-Frederic; Poulain, Daniel; Jouault, Thierry

    2013-03-18

    Crohn's disease (CD) is associated with elevated anti-glycans antibody response in 60% of CD patients, and 25% of healthy first-degree relatives (HFDRs), suggesting a genetic influence for this humoral response. In mice, anti-glucan antibody response depends on the NLRP3 inflammasome. Here, we explored the effect of mutated CARD8, a component of the inflammasome, on anti-glycans antibody response in human. The association between p.C10X mutation (rs2043211) of the CARD8 gene and the levels of anti-glycans antibody response was examined in 39 CD families. The family-based QTDT association test was used to test for the genetic association between CARD8 p.C10X mutation and anti-glycan antibodies in the pedigrees. The difference in antibody responses determined by ELISA was tested in a subgroup of CD probands (one per family) and in a subgroup of HFDRs using the Wilcoxon Kruskal Wallis non-parametric test. The QTDT familial transmission tests showed that the p.C10X mutation of CARD8 was significantly associated with lower levels of antibody to mannans and glucans but not chitin (p=0.024, p=0.0028 and p=0.577, for ASCA, ALCA and ACCA, respectively). These associations were independent of NOD2 and NOD1 genetic backgrounds. The p.C10X mutation significantly associated or displayed a trend toward lower ASCA and ALCA levels (p=0.038 and p=0.08, respectively) only in the subgroup of CD probands. Such associations were not significant for ACCA levels in both subgroups of CD probands and of HFDRs. Our results show that ASCA and ALCA but not ACCA levels are under the influence of CARD8 genotype. Alteration of CARD8, a component of inflammasome, is associated with lower levels of antibodies directed to mannans and glucans at least in CD patients.

  9. [Standardization of the quantitative flow cytometric test with anti-D antibodies for fetomaternal hemorrhage in RhD negative women].

    Science.gov (United States)

    Spychalska, Justyna; Uhrynowska, Małgorzata; Pyl, Hanna; Klimczak-Jajor, Edyta; Kopeć, Izabella; Peciakowska, Małgorzata; Gutowska, Renata; Gawlak, Maciej; Słomska, Sylwia; Dąbkowska, Syiwia; Szczecina, Roman; Dębska, Marzena; Brojer, Ewa

    2015-07-01

    In order to determine the appropriate dose of anti-D immunoglobulin to be administered as a preventive measure against hemolytic disease of the fetus/newborn in the subsequent pregnancy it is necessary to assess the number of fetal red blood cells that infiltrate/penetrate into the maternal circulation as a result of fetomaternal hemorrhage (FMH). One of the quantitative methods of FMH analysis is based on flow cytometry (FACS) which makes use of monoclonal antibodies to RhD antigen (anti-D test). The aim of the study was to further develop the method, evaluate its sensitivity and reproducibility and to compare it with the test based on the detection of fetal hemoglobin (HbF). The FACS study involved 20 RhD negative pregnant women and 80 RhD negative women after delivery. The following monoclonal antibodies were used: BRAD 3 FITC (anti-RhD antigen), CD45 PerCP (anti leukocyte antigen CD45), and anti-HbF PE. The fluorescence intensity of cells incubated with BRAD 3 FITC was demonstrated to depend on the RhD antigen expression, though the anti-D test also detects the weak D variant. The CD45 PerCP antibodies increased the sensitivity of anti-D test since they eliminated the leukocytes which non-specifically bind anti-D from the analysis. The presence of anti-D antibodies in maternal plasma does not affect the quantitative assessment of the fetal RhD positive fetal cells with BRAD 3 FITC. In case of FMH, the results of the anti-D test were similar to those with anti-HbF antibodies. The flow cytometric test with anti-D and anti-CD45 is useful in the assessment of the fetomaternal hemorrhage in RhD negative women. The sensitivity of the test is estimated at 0.05%.

  10. Monoclonal antibody 1.6.1 against human MPL receptor allows HSC enrichment of CB and BM CD34(+)CD38(-) populations.

    Science.gov (United States)

    Petit Cocault, Laurence; Fleury, Maud; Clay, Denis; Larghero, Jérôme; Vanneaux, Valérie; Souyri, Michèle

    2016-04-01

    Thrombopoietin (TPO) and its receptor Mpl (CD110) play a crucial role in the regulation of hematopoietic stem cells (HSCs). Functional study of Mpl-expressing HSCs has, however, been hampered by the lack of efficient monoclonal antibodies, explaining the very few data available on Mpl(+) HSCs during human embryonic development and after birth. Investigating the main monoclonal antibodies used so far to sort CD110(+) cells from cord blood (CB) and adult bone marrow (BM), we found that only the recent monoclonal antibody 1.6.1 engineered by Immunex Corporation was specific. Using in vitro functional assays, we found that this antibody can be used to sort a CD34(+)CD38(-)CD110(+) population enriched in hematopoietic progenitor stem cells, both in CB and in adult BM. In vivo injection into NSG mice further indicated that the CB CD34(+)CD38(-)CD110(+) population is highly enriched in HSCs compared with both CD34(+)CD38(-)CD110(-) and CD34(+)CD38(-) populations. Together our results validate MAb1.6.1 as an important tool, which has so far been lacking, in the HSC field. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  11. Immunotherapy of Alzheimer's disease (AD): from murine models to anti-amyloid beta (Abeta) human monoclonal antibodies.

    Science.gov (United States)

    Geylis, Valeria; Steinitz, Michael

    2006-01-01

    The deposition of amyloid beta (Abeta) protein is a key pathological feature in Alzheimer's disease (AD). In murine models of AD, both active and passive immunization against Abeta induce a marked reduction in amyloid brain burden and an improvement in cognitive functions. Preliminary results of a prematurely terminated clinical trial where AD patients were actively vaccinated with aggregated Abeta bear resemblance to those documented in murine models. Passive immunization of AD patients with anti-Abeta antibodies, in particular human antibodies, is a strategy that provides a more cautious management and control of any undesired side effects. Sera of all healthy adults contain anti-Abeta IgG autoimmune antibodies. Hence antigen-committed human B-cells are easily immortalized by Epstein-Barr virus (EBV) into anti-Abeta secreting cell lines. Two anti-Abeta human monoclonal antibodies which we recently prepared bind to the N-terminus of Abeta peptide and were shown to stain amyloid plaques in non-fixed brain sections from an AD patient. It is anticipated that specifically selected anti-Abeta human monoclonal antibodies could reduce and inhibit deposits of amyloid in brain while avoiding the cognitive decline that characterizes AD. In the future, this type of antibody may prove to be a promising immune therapy for the disease.

  12. Antitumor effect of novel anti-podoplanin antibody NZ-12 against malignant pleural mesothelioma in an orthotopic xenograft model.

    Science.gov (United States)

    Abe, Shinji; Kaneko, Mika Kato; Tsuchihashi, Yuki; Izumi, Toshihiro; Ogasawara, Satoshi; Okada, Naoto; Sato, Chiemi; Tobiume, Makoto; Otsuka, Kenji; Miyamoto, Licht; Tsuchiya, Koichiro; Kawazoe, Kazuyoshi; Kato, Yukinari; Nishioka, Yasuhiko

    2016-09-01

    Podoplanin (aggrus) is highly expressed in several types of cancers, including malignant pleural mesothelioma (MPM). Previously, we developed a rat anti-human podoplanin mAb, NZ-1, and a rat-human chimeric anti-human podoplanin antibody, NZ-8, derived from NZ-1, which induced antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity against podoplanin-positive MPM cell lines. In this study, we showed the antitumor effect of NZ-1, NZ-8, and NZ-12, a novel rat-human chimeric anti-human podoplanin antibody derived from NZ-1, in an MPM orthotopic xenograft SCID mouse model. Treatment with NZ-1 and rat NK (CD161a(+) ) cells inhibited the growth of tumors and the production of pleural effusion in NCI-H290/PDPN or NCI-H226 orthotopic xenograft mouse models. NZ-8 and human natural killer (NK) (CD56(+) ) cells also inhibited tumor growth and pleural effusion in MPM orthotopic xenograft mice. Furthermore, NZ-12 induced potent ADCC mediated by human MNC, compared with either NZ-1 or NZ-8. Antitumor effects were observed following treatment with NZ-12 and human NK (CD56(+) ) cells in MPM orthotopic xenograft mice. In addition, combined immunotherapy using the ADCC activity of NZ-12 mediated by human NK (CD56(+) ) cells with pemetrexed, led to enhanced antitumor effects in MPM orthotopic xenograft mice. These results strongly suggest that combination therapy with podoplanin-targeting immunotherapy using both NZ-12 and pemetrexed might provide an efficacious therapeutic strategy for the treatment of MPM. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  13. Chimeric antigen receptor (CAR-specific monoclonal antibody to detect CD19-specific T cells in clinical trials.

    Directory of Open Access Journals (Sweden)

    Bipulendu Jena

    Full Text Available Clinical trials targeting CD19 on B-cell malignancies are underway with encouraging anti-tumor responses. Most infuse T cells genetically modified to express a chimeric antigen receptor (CAR with specificity derived from the scFv region of a CD19-specific mouse monoclonal antibody (mAb, clone FMC63. We describe a novel anti-idiotype monoclonal antibody (mAb to detect CD19-specific CAR(+ T cells before and after their adoptive transfer. This mouse mAb was generated by immunizing with a cellular vaccine expressing the antigen-recognition domain of FMC63. The specificity of the mAb (clone no. 136.20.1 was confined to the scFv region of the CAR as validated by inhibiting CAR-dependent lysis of CD19(+ tumor targets. This clone can be used to detect CD19-specific CAR(+ T cells in peripheral blood mononuclear cells at a sensitivity of 1∶1,000. In clinical settings the mAb is used to inform on the immunophenotype and persistence of administered CD19-specific T cells. Thus, our CD19-specific CAR mAb (clone no. 136.20.1 will be useful to investigators implementing CD19-specific CAR(+ T cells to treat B-lineage malignancies. The methodology described to develop a CAR-specific anti-idiotypic mAb could be extended to other gene therapy trials targeting different tumor associated antigens in the context of CAR-based adoptive T-cell therapy.

  14. Clinical relevance of pre and post-transplant immune markers in kidney allograft recipients: anti-HLA and MICA antibodies and serum levels of sCD30 and sMICA.

    Science.gov (United States)

    Solgi, Ghasem; Furst, Daniel; Mytilineos, Joannis; Pourmand, Gholamreza; Amirzargar, Ali Akbar

    2012-03-01

    This retrospective study aims to determine the prognostic values of HLA and MICA antibodies, serum levels of sCD30 and soluble form of MHC class I related chain A (sMICA) in kidney allograft recipients. Sera samples of 40 living unrelated donor kidney recipients were tested by ELISA and Flow beads techniques for the presence of anti HLA and MICA antibodies and the contents of sCD30 and sMICA. HLA and MICA antibody specification was performed by LABScreen single antigen beads to determine whether the antibodies were directed against donor mismatches. Within first year post operatively 9 of 40 patients (22.5%) showed acute rejection episodes (ARE) that four of them lost their grafts compared to 31 functioning transplants (P=0.001). The presence of HLA antibodies before and after transplantation was significantly associated with ARE (P=0.01 and P=0.02 respectively). Sensitization to HLA class II antigens pre-transplant was strongly associated with higher incidence of ARE (P=0.004). A significant correlation was found between ARE and appearance of non-donor specific antibodies (P=0.02). HLA antibody positive patients either before or after transplantation showed lower graft survival rates than those without antibodies during three years follow-up (P=0.04 and P=0.02). Anti-MICA antibodies were observed in 8/40(20%) and 5/40(12.5%) of patients pre and post-transplant respectively. Coexistence of HLA and MICA antibodies was shown in 2 of 4 cases with graft loss. A significant increased level of sCD30 at day 14 (P=0.001) and insignificant decreased levels of sMICA pre and post operatively were detected in rejecting transplants compared to functioning graft group. Our findings support the view that monitoring of HLA and MICA antibodies as well as sCD30 levels early after transplant has predictive value for early and late allograft dysfunctions and the presence of these factors are detrimental to graft function and survival. Copyright © 2012 Elsevier B.V. All rights

  15. Immunoassay of serum polypeptide hormones by using 125I-labelled anti(-immunoglobulin G) antibodies.

    Science.gov (United States)

    Beck, P; Nicholas, H

    1975-03-01

    1. A technique for indirectly labelling antibodies to polypeptide hormones, by combining them with radioactively labelled anti-(immunoglobulin G) is described. (a) 125I-labelled anti-(rabbit immunoglobulin G) and anti-(guinea-pig immunoglobulin G) antibodies with high specific radioactivity were prepared after purification of the antibodies on immunoadsorbents containing the respective antigens. (b) Rabbit immunoglobulin G antibodies to human growth hormone, porcine glucagon and guinea-pig immunoglobulin G antibodies to bovine insulin and bovine parathyroid hormone were combined with immunoadsorbents containing the respective polypeptide hormone antigen. (c) The immunoglobulin G antibodies to the polypeptide hormones were reacted with 125-I-labelled anti-(immunoglobulin G) antibodies directed against the appropriate species of immunoglobulin G,and the anti-hormone antibodies were combined with the hormone-containing immunoadsorbent. (d) 125I-labelled anti-(immunoglobulin G) antibodies and anti-hormone antibodies were simultaneously eluted from the hormone-containing immunoadsorbent by dilute HCl, pH 2.0. After elution the anti-(immunoglobulin G) antibodies and antihormone antibodies were allowed to recombine at pH 8.0 and 4 degrees C. 2. The resultant immunoglobulin G-anti-immunoglobulin G complex was used in immunoradiometric (labelled antibody) and two-site assays of the respective polypeptide hormone. 3. By using these immunoassays, concentrations down to 90pg of human growth hormone/ml, 100 pg of bovine insulin/ml, 80 pg of bovine parathyroid hormone/ml and 150 pg of glucagon/ml were readily detected. Assays of human plasma for growth hormone and insulin by these methods showed good agreement with results obtained by using a directly 125I-labelled anti-hormone antibody in an immunoradiometric assay of human growth hormone or by radioimmunoassay of human insulin. 4. The method described allows immunoradiometric or two-site assays to be performed starting with as

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

    International Nuclear Information System (INIS)

    Ishiura, Yoshihito; Kotani, Norihiro; Yamashita, Ryusuke; Yamamoto, Harumi; Kozutsumi, Yasunori; Honke, Koichi

    2010-01-01

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

  17. Preparation of anti-CD4 monoclonal antibody-conjugated magnetic poly(glycidyl methacrylate) particles and their application on CD4+ lymphocyte separation.

    Science.gov (United States)

    Pimpha, Nuttaporn; Chaleawlert-umpon, Saowaluk; Chruewkamlow, Nuttapol; Kasinrerk, Watchara

    2011-03-15

    Novel immunomagnetic particles have been prepared for separation of CD4(+) lymphocytes. The magnetic nanoparticles with a diameter of approximately 5-6 nm were first synthesized by co-precipitation from ferrous and ferric iron solutions and subsequently encapsulated with poly(glycidyl methacrylate) (PGMA) by precipitation polymerization. Monoclonal antibody specific to CD4 molecules expressed on CD4(+) lymphocytes was conjugated to the surface of magnetic PGMA particles through covalent bonding between epoxide functional groups on the particle surface and primary amine groups of the antibodies. The generated immunomagnetic particles have successfully separated CD4(+) lymphocytes from whole blood with over 95% purity. The results indicated that these particles can be employed for cell separation and provide a strong potential to be applied in various biomedical applications including diagnosis, and monitoring of human diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Anti-CD20 Cell Therapies in Multiple Sclerosis—A Fixed Dosing Schedule for Ocrelizumab is Overkill

    Directory of Open Access Journals (Sweden)

    Jagannadha Avasarala

    2017-10-01

    Full Text Available Anti-CD 20 therapies have found significant uses in multiple sclerosis (MS. Based singularly on the accumulated evidence with the use of rituximab (RTX; Rituxan, Genentech, and Biogen in neuroimmunological diseases, ocrelizumab (OCR; Ocrevus, Genentech was developed as a treatment option for MS and selectively targets CD20 B cells, a cell surface antigen found on pre-B cells, mature, and memory B cells, but not on lymphoid stem cells and plasma cells. On the basis of indirect evidence, elimination of the antigen-presenting capabilities and antigen nonspecific immune functions of B cells appear to be central to the therapeutic efficacy of anti-CD20 B-cell therapies. An important question is this—Why does the drug need to be dosed at fixed intervals and not based on a measurable endpoint, such as tracking peripheral CD20 cell counts? There is minimal scientific validity in infusing the drug every 6 months particularly if CD20 cell counts are negligible in the peripheral blood. In this analysis, a case is made for following CD19 cell populations as a surrogate for CD20 cells on a monthly basis to guide OCR redosing parameters and does not follow a scheduled dosing parameter.

  19. Evaluation of (89Zr-labeled human anti-CD147 monoclonal antibody as a positron emission tomography probe in a mouse model of pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Aya Sugyo

    Full Text Available INTRODUCTION: Pancreatic cancer is an aggressive cancer and its prognosis remains poor. Therefore, additional effective therapy is required to augment and/or complement current therapy. CD147, high expression in pancreatic cancer, is involved in the metastatic process and is considered a good candidate for targeted therapy. CD147-specfic imaging could be useful for selection of appropriate patients. Therefore, we evaluated the potential of a fully human anti-CD147 monoclonal antibody 059-053 as a new positron emission tomography (PET probe for pancreatic cancer. METHODS: CD147 expression was evaluated in four pancreatic cancer cell lines (MIA Paca-2, PANC-1, BxPC-3, and AsPC-1 and a mouse cell line A4 as a negative control. Cell binding, competitive inhibition and internalization assays were conducted with (125I-, (67Ga-, or (89Zr-labeled 059-053. In vivo biodistribution of (125I- or (89Zr-labeled 059-053 was conducted in mice bearing MIA Paca-2 and A4 tumors. PET imaging with [(89Zr]059-053 was conducted in subcutaneous and orthotopic tumor mouse models. RESULTS: Among four pancreatic cancer cell lines, MIA Paca-2 cells showed the highest expression of CD147, while A4 cells had no expression. Immunohistochemical staining showed that MIA Paca-2 xenografts also highly expressed CD147 in vivo. Radiolabeled 059-053 specifically bound to MIA Paca-2 cells with high affinity, but not to A4. [(89Zr]059-053 uptake in MIA Paca-2 tumors increased with time from 11.0±1.3% injected dose per gram (ID/g at day 1 to 16.9±3.2% ID/g at day 6, while [(125I]059-053 uptake was relatively low and decreased with time, suggesting that 059-053 was internalized into tumor cells in vivo and (125I was released from the cells. PET with [(89Zr]059-053 clearly visualized subcutaneous and orthotopic tumors. CONCLUSION: [(89Zr]059-053 is a promising PET probe for imaging CD147 expression in pancreatic cancer and has the potential to select appropriate patients with CD147

  20. Serum anti-glycan antibodies in paediatric-onset Crohn's disease: association with disease phenotype and diagnostic accuracy.

    Science.gov (United States)

    Sładek, Małgorzata; Wasilewska, Agata; Swiat, Agnieszka; Cmiel, Adam

    2014-01-01

    Antibodies reacting with various microbial epitopes have been described in inflammatory bowel disease (IBD) and are associated with a specific diagnosis and clinical presentation. To evaluate the profile of new anti-glycan antibodies, their potential association with disease phenotype and diagnostic accuracy in paediatric Crohn's disease (CD). Blood samples from 134 paediatric IBD patients (109 CD, 25 ulcerative colitis (UC)) and 67 controls were blindly analysed for anti-Saccharomyces cerevisiae (ASCA), anti-chitobioside carbohydrate (ACCA), anti-laminaribioside carbohydrate (ALCA), and anti-mannobioside carbohydrate (AMCA) antibodies using commercially available assays. The serological response to glycans was correlated with clinical disease characteristics. At least one of the tested anti-glycan antibodies was present in 75% of CD patients. Despite the high frequency of reactivity to glycan epitopes, a limited overlap of serological markers was observed. In total, 49% of ASCA-negative patients presented with one of the following: ACCA, ALCA, or AMCA. The occurrence of one antibody from the anti-glycan panel was independently associated with complicated disease phenotype and ileocolonic disease location. A higher level of immune response as assessed by the quartile sum scores for ACCA, ALCA, and AMCA was linked with older age at diagnosis (10-17 years) and ileocolonic disease location. The ASCA had the greatest accuracy for diagnosis and differentiation of CD. Qualitative and quantitative serologicalal response to glycan epitopes was associated with distinct clinical presentation in paediatric CD patients. This raises the possibility for the use of these markers to differentiate subgroups of CD patients with more sever clinical presentation. The ASCA was the most accurate serological marker for CD; however, testing for the new anti-glycan antibodies may constitute an adjunctive tool in a specific group of patients to aid in the differentiation of CD with absent

  1. Immuno-biosensor for Detection of CD20-Positive Cells Using Surface Plasmon Resonance

    Science.gov (United States)

    Shanehbandi, Dariush; Majidi, Jafar; Kazemi, Tohid; Baradaran, Behzad; Aghebati-Maleki, Leili; Fathi, Farzaneh; Ezzati Nazhad Dolatabadi, Jafar

    2017-01-01

    Purpose: Surface plasmon resonance (SPR) sensing confers a real-time assessment of molecular interactions between biomolecules and their ligands. This approach is highly sensitive and reproducible and could be employed to confirm the successful binding of drugs to cell surface targets. The specific affinity of monoclonal antibodies (MAb) for their target antigens is being utilized for development of immuno-sensors and therapeutic agents. CD20 is a surface protein of B lymphocytes which has been widely employed for immuno-targeting of B-cell related disorders. In the present study, binding ability of an anti-CD20 MAb to surface antigens of intact target cells was investigated by SPR technique. Methods: Two distinct strategies were used for immobilization of the anti-CD20 MAb onto gold (Au) chips. MUA (11-mercaptoundecanoic acid) and Staphylococcus aureus protein A (SpA) were the two systems used for this purpose. A suspension of CD20-positive Raji cells was injected in the analyte phase and the resulting interactions were analyzed and compared to those of MOLT-4 cell line as CD20-negative control. Results: Efficient binding of anti-CD20 MAb to the surface antigens of Raji cell line was confirmed by both immobilizing methods, whereas this MAb had not a noticeable affinity to the MOLT-4 cells. Conclusion: According to the outcomes, the investigated MAb had acceptable affinity and specificity to the target antigens on the cell surface and could be utilized for immuno-detection of CD20-positive intact cells by SPR method. PMID:28761820

  2. Isolation and partial characterization of peripheral blood CD4+ T cell clones expressing γδT cell receptors

    International Nuclear Information System (INIS)

    Kyoizumi, Seishi; Akiyama, Mitoshi; Hirai, Yuko; Kusunoki, Yoichiro.

    1990-06-01

    Rare T cell clones bearing both CD4 and T cell receptors (TCRγ and TCRδ) were obtained from human peripheral blood by cell sorting using anti-CD4 and anti-TCRδ1 antibodies. All the clones established were reactive with anti-TCRγδ1 antibody, whereas only about 20 % of the clones showed reactivity with anti-δTCS1 antibody. Unlike CD4 + T cells bearing TCRαβ, all the clones tested were lectin-dependent and showed CD3 antibody-redirected cytolytic activity. About 60 % exhibited natural killer cell-like activity. Immunoprecipitation analysis of TCRγδ showed that each clone expressed either a disulfide-linked or nondisulfide-linked heterodimer consisting of 37-44 kilodalton TCRγ and TCRδ chains. Southern blot analyses of TCRγ and TCRδ genes revealed some identical rearrangement patterns, suggesting the limited heterogeneity of CD4 + TCRγδ + T cells in peripheral blood. (author)

  3. Oriented immobilized anti-LDL antibody carrying poly(hydroxyethyl methacrylate) cryogel for cholesterol removal from human plasma

    International Nuclear Information System (INIS)

    Bereli, Nilay; Sener, Guelsu; Yavuz, Handan; Denizli, Adil

    2011-01-01

    Low density lipoprotein (LDL) cholesterol is a major ingredient of the plaque that collects in the coronary arteries and causes coronary heart diseases. Among the methods used for the extracorporeal elimination of LDL from intravasal volume, immunoaffinity technique using anti-LDL antibody as a ligand offers superior selectivity and specificity. Proper orientation of the immobilized antibody is the main issue in immunoaffinity techniques. In this study, anti-human β-lipoprotein antibody (anti-LDL antibody) molecules were immobilized and oriented through protein A onto poly(2-hydroxyethyl methacrylate) (PHEMA) cryogel in order to remove LDL from hypercholesterolemic human plasma. PHEMA cryogel was prepared by free radical polymerization initiated with N,N,N',N'-tetramethylene diamine (TEMED). PHEMA cryogel with a swelling degree of 8.89 g H 2 O/g and 67% macro-porosity was characterized by swelling studies, scanning electron microscope (SEM) and blood compatibility tests. All the clotting times were increased when compared with control plasma. The maximum immobilized anti-LDL antibody amount was 63.2 mg/g in the case of random antibody immobilization and 19.6 mg/g in the case of oriented antibody immobilization (protein A loading was 57.0 mg/g). Random and oriented anti-LDL antibody immobilized PHEMA cryogels adsorbed 111 and 129 mg LDL/g cryogel from hypercholesterolemic human plasma, respectively. Up to 80% of the adsorbed LDL was desorbed. The adsorption-desorption cycle was repeated 6 times using the same cryogel. There was no significant loss of LDL adsorption capacity. - Research highlights: → LDL cholesterol is a risk factor in the development of coronary heart diseases. → Antibodies against LDL are used for the selective extracorporeal removal of LDL. → Protein A is used for the oriented immobilization of anti LDL onto PHEMA cryogel. → PHEMA cryogels are biocompatible, exhibit a low pressure drop, lack diffusion resistance and viscous samples can be

  4. Oriented immobilized anti-LDL antibody carrying poly(hydroxyethyl methacrylate) cryogel for cholesterol removal from human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bereli, Nilay [Department of Chemistry, Hacettepe University, Beytepe, Ankara (Turkey); Sener, Guelsu [Nanotechnology and Nanomedicine Division, Hacettepe University, Ankara (Turkey); Yavuz, Handan, E-mail: handany@hacettepe.edu.tr [Department of Chemistry, Hacettepe University, Beytepe, Ankara (Turkey); Denizli, Adil [Department of Chemistry, Hacettepe University, Beytepe, Ankara (Turkey)

    2011-07-20

    Low density lipoprotein (LDL) cholesterol is a major ingredient of the plaque that collects in the coronary arteries and causes coronary heart diseases. Among the methods used for the extracorporeal elimination of LDL from intravasal volume, immunoaffinity technique using anti-LDL antibody as a ligand offers superior selectivity and specificity. Proper orientation of the immobilized antibody is the main issue in immunoaffinity techniques. In this study, anti-human {beta}-lipoprotein antibody (anti-LDL antibody) molecules were immobilized and oriented through protein A onto poly(2-hydroxyethyl methacrylate) (PHEMA) cryogel in order to remove LDL from hypercholesterolemic human plasma. PHEMA cryogel was prepared by free radical polymerization initiated with N,N,N',N'-tetramethylene diamine (TEMED). PHEMA cryogel with a swelling degree of 8.89 g H{sub 2}O/g and 67% macro-porosity was characterized by swelling studies, scanning electron microscope (SEM) and blood compatibility tests. All the clotting times were increased when compared with control plasma. The maximum immobilized anti-LDL antibody amount was 63.2 mg/g in the case of random antibody immobilization and 19.6 mg/g in the case of oriented antibody immobilization (protein A loading was 57.0 mg/g). Random and oriented anti-LDL antibody immobilized PHEMA cryogels adsorbed 111 and 129 mg LDL/g cryogel from hypercholesterolemic human plasma, respectively. Up to 80% of the adsorbed LDL was desorbed. The adsorption-desorption cycle was repeated 6 times using the same cryogel. There was no significant loss of LDL adsorption capacity. - Research highlights: {yields} LDL cholesterol is a risk factor in the development of coronary heart diseases. {yields} Antibodies against LDL are used for the selective extracorporeal removal of LDL. {yields} Protein A is used for the oriented immobilization of anti LDL onto PHEMA cryogel. {yields} PHEMA cryogels are biocompatible, exhibit a low pressure drop, lack diffusion

  5. Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

    Science.gov (United States)

    Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

    1989-03-15

    Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

  6. Anti-CD3 Antibody Ameliorates Transfusion-Associated Graft-Versus-Host Disease in a Chemotherapy-Based Mouse Model With Busulfan and Fludarabine

    Directory of Open Access Journals (Sweden)

    Xiaofan Li

    2017-05-01

    Full Text Available ABSTRACT To establish a transfusion-associated graft-versus-host disease (TA-GVHD mouse model with busulfan and fludarabine for effective treatment evaluation. BALB/c (H-2d mice were injected with busulfan (15 mg/kg and fludarabine (30 mg/kg twice a day for 4 days. The mice were transfused with 106 T cell-depleted bone marrow (TCD-BM and cells in different groups 3 days after chemotherapy: syngeneic BALB/c, MHC minor mismatch DBA/2 (H-2d, or MHC major mismatch C57BL/6(H2-b. Recipient BALB/c mice were injected with either blood only or blood+splenocyte. TA-GVHD was monitored in terms of body weight loss, clinical scores, and survival. Dexamethasone (50 mg/kg, cyclophosphamide (50 mg/kg, cyclosporine A (30 mg/kg, and anti-CD3 (1 mg/kg were injected to each group to examine the treatments. Blood transfusion alone is insufficient to induce TA-GVHD in a chemotherapy-based mouse model. A MHC-mismatched TA-GVHD model can be induced by splenocyte and blood transfusion. This MHC-mismatched TA-GVHD model was resistant to dexamethasone treatment. Treatment based on anti-CD3 monoclonal antibody slightly ameliorated TA-GVHD. Treatment effectiveness was associated with T-cell depletion following activation by anti-CD3. Busulfan and fludarabine chemotherapy regimen can be used to establish a TA-GVHD mouse model. Anti-CD3 monoclonal antibody is a potential alternative to treat TA-GVHD.

  7. Characterisation of CD4 T cells in healthy and diseased koalas (Phascolarctos cinereus) using cell-type-specific monoclonal antibodies.

    Science.gov (United States)

    Mangar, Chandan; Armitage, Charles W; Timms, Peter; Corcoran, Lynn M; Beagley, Kenneth W

    2016-07-01

    The koala (Phascolarctos cinereus) is an arboreal herbivorous marsupial that is an Australian icon. Koalas in many parts of Australia are under multiple threats including habitat destruction, dog attacks, vehicular accidents, and infectious diseases such as Chlamydia spp. and the koala retrovirus (KoRV), which may contribute to the incidence of lymphoma and leukaemia in this species. Due to a lack of koala-specific immune reagents and assays there is currently no way to adequately analyse the immune response in healthy, diseased or vaccinated animals. This paper reports the production and characterisation of the first anti-koala CD4 monoclonal antibody (mAb). The koala CD4 gene was identified and used to develop recombinant proteins for mAb production. Fluorochrome-conjugated anti-CD4 mAb was used to measure the levels of CD4(+) lymphocytes collected from koala spleens (41.1%, range 20-45.1%) lymph nodes (36.3%, range 19-55.9%) and peripheral blood (23.8%, range 17.3-35%) by flow cytometry. Biotin-conjugated anti-CD4 mAb was used for western blot to determine an approximate size of 52 kDa for the koala CD4 molecule and used in immunohistochemistry to identify CD4(+) cells in the paracortical region and germinal centres of spleen and lymph nodes. Using the anti-CD4 mab we showed that CD4 cells from vaccinated, but not control, koalas proliferated following in vitro stimulation with UV-inactivated Chlamydia pecorum and recombinant chlamydial antigens. Since CD4(+) T cells have been shown to play a pivotal role in clearing chlamydial infection in both human and mouse infections, using this novel antibody will help determine the role CD4(+) T cells play in protection against chlamydial infection in koalas and also enhance our knowledge of how KoRV affects the koala immune system. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    -linking of CD73, because both whole IgG anti-CD73 AD2 mAb and Fab' fragments thereof exhibited this effect. Ex vivo treatment of different breast cancer cell lines with anti-CD73 AD2 mAb before i.v. injection into mice inhibited extravasation/colonization of circulating tumor cells and significantly reduced...

  9. The feasibility research of galactosyl-anti-mouse CD3 monoclonal antibody being used as carrier of immunotherapy after surgical operation of liver cancer

    International Nuclear Information System (INIS)

    Li Yunchun; Guan Changtian; Yang Xiaochuan; He Sheng; Jiang Ping; Yuan Lin

    2000-01-01

    Objective: To probe into the feasibility of galactosyl-anti-mouse CD 3 monoclonal antibody (Gal-Ant-CD 3 McAb) being used as carrier of immunotherapy after surgical operation of liver cancer. Methods: Gal-Ant-CD 3 McAb was prepared by the covalent coupling of anti-mouse CD 3 monoclonal antibody (Ant-CD 3 McAb) with a bifunctional reagent, 2-imino-2-methoxyethyl-1-thio-galactose. After Gal-Ant-CD 3 McAb and Ant-CD 3 McAb were labelled with 131 I or 125 I, the data of biodistribution in mice, and of imaging in rabbit were obtained. After tumour infiltrating lymphocytes (TIL) and Gal-Ant-CD 3 McAb were coupled into Gal-Ant-CD 3 McAb-TIL, its liver taxis and cytotoxic activity against autologous cancer cells were measured in vitro. Results: Gal-Ant-CD 3 McAb had remarkable livertaxis and its uptake in per gram liver was (59.0 +- 2.1)% that was more than two-fold higher than that of Ant-CD 3 McAb. Gal-Ant-CD 3 McAb-TIL had an obvious liver taxis and cytotoxic activity against autologous cancer cells in vitro. Conclusion: Gal-Ant-CD 3 McAb can be used as the carrier of immunotherapy after surgical operation of liver cancer

  10. The human CD38 monoclonal antibody daratumumab shows antitumor activity and hampers leukemia-microenvironment interactions in chronic lymphocytic leukemia

    DEFF Research Database (Denmark)

    Matas-Céspedes, Alba; Vidal-Crespo, Anna; Rodriguez, Vanina

    2017-01-01

    Purpose: To establish a proof-of-concept for the efficacy of the anti-CD38 antibody daratumumab in the poor prognosis CD38+ chronic lymphocytic leukemia (CLL) subtype. Experimental Design: The mechanism of action of daratumumab was assessed in CLL primary cells and cell lines using peripheral blo...

  11. Contribution of herpesvirus specific CD8 T cells to anti-viral T cell response in humans.

    Directory of Open Access Journals (Sweden)

    Elena Sandalova

    Full Text Available Herpesviruses infect most humans. Their infections can be associated with pathological conditions and significant changes in T cell repertoire but evidences of symbiotic effects of herpesvirus latency have never been demonstrated. We tested the hypothesis that HCMV and EBV-specific CD8 T cells contribute to the heterologous anti-viral immune response. Volume of activated/proliferating virus-specific and total CD8 T cells was evaluated in 50 patients with acute viral infections: 20 with HBV, 12 with Dengue, 12 with Influenza, 3 with Adenovirus infection and 3 with fevers of unknown etiology. Virus-specific (EBV, HCMV, Influenza pentamer+ and total CD8 T cells were analyzed for activation (CD38/HLA-DR, proliferation (Ki-67/Bcl-2(low and cytokine production. We observed that all acute viral infections trigger an expansion of activated/proliferating CD8 T cells, which differs in size depending on the infection but is invariably inflated by CD8 T cells specific for persistent herpesviruses (HCMV/EBV. CD8 T cells specific for other non-related non persistent viral infection (i.e. Influenza were not activated. IL-15, which is produced during acute viral infections, is the likely contributing mechanism driving the selective activation of herpesvirus specific CD8 T cells. In addition we were able to show that herpesvirus specific CD8 T cells displayed an increased ability to produce the anti-viral cytokine interferon-gamma during the acute phase of heterologous viral infection. Taken together, these data demonstrated that activated herpesvirus specific CD8 T cells inflate the activated/proliferating CD8 T cells population present during acute viral infections in human and can contribute to the heterologous anti-viral T cell response.

  12. Preclinical activity of the type II CD20 antibody GA101 (obinutuzumab) compared with rituximab and ofatumumab in vitro and in xenograft models.

    Science.gov (United States)

    Herter, Sylvia; Herting, Frank; Mundigl, Olaf; Waldhauer, Inja; Weinzierl, Tina; Fauti, Tanja; Muth, Gunter; Ziegler-Landesberger, Doris; Van Puijenbroek, Erwin; Lang, Sabine; Duong, Minh Ngoc; Reslan, Lina; Gerdes, Christian A; Friess, Thomas; Baer, Ute; Burtscher, Helmut; Weidner, Michael; Dumontet, Charles; Umana, Pablo; Niederfellner, Gerhard; Bacac, Marina; Klein, Christian

    2013-10-01

    We report the first preclinical in vitro and in vivo comparison of GA101 (obinutuzumab), a novel glycoengineered type II CD20 monoclonal antibody, with rituximab and ofatumumab, the two currently approved type I CD20 antibodies. The three antibodies were compared in assays measuring direct cell death (AnnexinV/PI staining and time-lapse microscopy), complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cell-mediated phagocytosis (ADCP), and internalization. The models used for the comparison of their activity in vivo were SU-DHL4 and RL xenografts. GA101 was found to be superior to rituximab and ofatumumab in the induction of direct cell death (independent of mechanical manipulation required for cell aggregate disruption formed by antibody treatment), whereas it was 10 to 1,000 times less potent in mediating CDC. GA101 showed superior activity to rituximab and ofatumumab in ADCC and whole-blood B-cell depletion assays, and was comparable with these two in ADCP. GA101 also showed slower internalization rate upon binding to CD20 than rituximab and ofatumumab. In vivo, GA101 induced a strong antitumor effect, including complete tumor remission in the SU-DHL4 model and overall superior efficacy compared with both rituximab and ofatumumab. When rituximab-pretreated animals were used, second-line treatment with GA101 was still able to control tumor progression, whereas tumors escaped rituximab treatment. Taken together, the preclinical data show that the glyoengineered type II CD20 antibody GA101 is differentiated from the two approved type I CD20 antibodies rituximab and ofatumumab by its overall preclinical activity, further supporting its clinical investigation. ©2013 AACR.

  13. Soluble CD30 and ELISA-detected human leukocyte antigen antibodies for the prediction of acute rejection in pediatric renal transplant recipients.

    Science.gov (United States)

    Billing, Heiko; Sander, Anja; Süsal, Caner; Ovens, Jörg; Feneberg, Reinhard; Höcker, Britta; Vondrak, Karel; Grenda, Ryszard; Friman, Stybjorn; Milford, David V; Lucan, Mihai; Opelz, Gerhard; Tönshoff, Burkhard

    2013-03-01

    Biomarker-based post-transplant immune monitoring for the prediction of impending graft rejection requires validation in specific patient populations. Serum of 28 pediatric renal transplant recipients within the framework of a well-controlled prospective randomized trial was analyzed pre- and post-transplant for soluble CD30 (sCD30), a biomarker reflecting mainly T-cell reactivity, and anti-human leukocyte antigen (anti-HLA) antibody reactivity, a biomarker for B-cell activation. A sCD30 concentration ≥40.3 U/ml on day 14 was able to discriminate between patients with or without biopsy-proven acute rejection (BPAR) with a sensitivity of 100% and a specificity of 76%. Six of seven patients (86%) with BPAR showed a sCD30 above this cut-off, whereas only 3/21 patients (14%) without BPAR had a sCD30 above this cut-off (P = 0.004). For pre- and post-transplant anti-HLA class II reactivities by enzyme-linked immunosorbent assay, a cut-off value of 140 optical density was able to discriminate rejecters from nonrejecters with a sensitivity of 86% or 71% and a specificity of 81% or 90%, respectively. Withdrawal of steroids was associated with a approximately twofold higher serum sCD30 compared to controls, but did not affect anti-HLA reactivities. An increased post-transplant sCD30 serum concentration and positive pre- and post-transplant anti-HLA class II reactivities are informative biomarkers for impending BPAR in pediatric renal transplant recipients. (TWIST, Clinical Trial No: FG-506-02-43). © 2012 The Authors Transplant International © 2012 European Society for Organ Transplantation. Published by Blackwell Publishing Ltd.

  14. Monoclonal antibodies targeting CD38 in hematological malignancies and beyond

    DEFF Research Database (Denmark)

    van de Donk, Niels W C J; Janmaat, Maarten L.; Mutis, Tuna

    2016-01-01

    CD38 is a multifunctional cell surface protein that has receptor as well as enzyme functions. The protein is generally expressed at low levels on various hematological and solid tissues, while plasma cells express particularly high levels of CD38. The protein is also expressed in a subset of hema...... strong anti-tumor activity in preclinical models. The antibody engages diverse mechanisms of action, including complement-dependent cytotoxicity, antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, programmed cell death, modulation of enzymatic activity...... combination therapies with existing as well as emerging therapies, which are currently evaluated in the clinic. Finally, CD38 antibodies may have a role in the treatment of diseases beyond hematological malignancies, including solid tumors and antibody-mediated autoimmune diseases. © 2016 John Wiley & Sons A....../S. Published by John Wiley & Sons Ltd....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-05-28

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

  16. Preparation and Evaluation of 99mTc-labeled anti-CD11b Antibody Targeting Inflammatory Microenvironment for Colon Cancer Imaging.

    Science.gov (United States)

    Cheng, Dengfeng; Zou, Weihong; Li, Xiao; Xiu, Yan; Tan, Hui; Shi, Hongcheng; Yang, Xiangdong

    2015-06-01

    CD11b, an active constituent of innate immune response highly expressed in myeloid-derived suppressor cells (MDSCs), can be used as a marker of inflammatory microenvironment, particularly in tumor tissues. In this research, we aimed to fabricate a (99m)Tc-labeled anti-CD11b antibody as a probe for CD11b(+) myeloid cells in colon cancer imaging with single-photon emission computed tomography (SPECT). In situ murine colon tumor model was established in histidine decarboxylase knockout (Hdc(-/-)) mice by chemicals induction. (99m)Tc-labeled anti-CD11b was obtained with labeling yields of over 30% and radiochemical purity of over 95%. Micro-SPECT/CT scans were performed at 6 h post injection to investigate biodistributions and targeting of the probe. In situ colonic neoplasma as small as 3 mm diameters was clearly identified by imaging; after dissection of the animal, anti-CD11b immunofluorescence staining was performed to identify infiltration of CD11b+ MDSCs in microenvironment of colonic neoplasms. In addition, the images displayed intense signal from bone marrow and spleen, which indicated the origin and migration of CD11b(+) MDSCs in vivo, and these results were further proved by flow cytometry analysis. Therefore, (99m)Tc-labeled anti-CD11b SPECT displayed the potential to facilitate the diagnosis of colon tumor in very early stage via detection of inflammatory microenvironment. © 2014 John Wiley & Sons A/S.

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

    Science.gov (United States)

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

    2012-06-01

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

  18. Clinical significance of serum anti-human papillomavirus 16 and 18 antibodies in cervical neoplasia.

    Science.gov (United States)

    Chay, Doo Byung; Cho, Hanbyoul; Kim, Bo Wook; Kang, Eun Suk; Song, Eunseop; Kim, Jae-Hoon

    2013-02-01

    To estimate the clinical significance of serum anti-human papillomavirus (HPV) antibodies and high-risk cervical HPV DNA in cervical neoplasia. The study population comprised patients who were histopathologically diagnosed with cervical intraepithelial neoplasia (CIN) 1 (n=64), CIN 2 and 3 (n=241), cervical cancer (n=170), and normal control participants (n=975). Cervical HPV DNA tests were performed through nucleic acid hybridization assay tests, and serum anti-HPV 16 and 18 antibodies were measured by competitive immunoassay. The associations of HPV DNA and anti-HPV antibodies were evaluated with demographic characteristics and compared according to the levels of disease severity. Anti-HPV antibodies were also investigated with clinicopathologic parameters, including survival data. Among various demographic characteristics, factors involving sexual behavior had a higher tendency of HPV DNA positivity and HPV seropositivity. Human papillomavirus DNA mean titer and positivity were both increased in patients with cervical neoplasia compared with those with normal control participants, but there was no statistical difference among types of cervical neoplasia. Serum anti-HPV 16 antibodies were also able to differentiate cervical neoplasia from a normal control participant and furthermore distinguished CIN 1 from CIN 2 and 3 (odd ratio 2.87 [1.43-5.78], P=.002). In cervical cancer, HPV 16 seropositivity was associated with prolonged disease-free survival according to the univariable analysis (hazard ratio=0.12 [0.01-0.94], P=.044). Serum anti-HPV 16 antibodies can distinguish cervical neoplasia from a normal control and has the advantage of identifying high-grade CIN. Moreover, in cervical cancer, HPV 16 seropositivity may be associated with a more favorable prognosis. II.

  19. The Role of Anti-Drug Antibodies in the Pharmacokinetics, Disposition, Target Engagement, and Efficacy of a GITR Agonist Monoclonal Antibody in Mice.

    Science.gov (United States)

    Brunn, Nicholas D; Mauze, Smita; Gu, Danling; Wiswell, Derek; Ueda, Roanna; Hodges, Douglas; Beebe, Amy M; Zhang, Shuli; Escandón, Enrique

    2016-03-01

    Administration of biologics to enhance T-cell function is part of a rapidly growing field of cancer immunotherapy demonstrated by the unprecedented clinical success of several immunoregulatory receptor targeting antibodies. While these biologic agents confer significant anti-tumor activity through targeted immune response modulation, they can also elicit broad immune responses potentially including the production of anti-drug antibodies (ADAs). DTA-1, an agonist monoclonal antibody against GITR, is a highly effective anti-tumor treatment in preclinical models. We demonstrate that repeated dosing with murinized DTA-1 (mDTA-1) generates ADAs with corresponding reductions in drug exposure and engagement of GITR on circulating CD3(+) CD4(+) T cells, due to rapid hepatic drug uptake and catabolism. Mice implanted with tumors after induction of preexisting mDTA-1 ADA show no anti-tumor efficacy when given 3 mg/kg mDTA-1, an efficacious dose in naive mice. Nonetheless, increasing mDTA-1 treatment to 30 mg/kg in ADA-positive mice restores mDTA-1 exposure and GITR engagement on circulating CD3(+) CD4(+) T cells, thereby partially restoring anti-tumor efficacy. Formation of anti-mDTA-1 antibodies and changes in drug exposure and disposition does not occur in GITR(-/-) mice, consistent with a role for GITR agonism in humoral immunity. Finally, the administration of muDX400, a murinized monoclonal antibody against the checkpoint inhibitor PD-1, dosed alone or combined with mDTA-1 did not result in reduced muDX400 exposure, nor did it change the nature of the anti-mDTA-1 response. This indicates that anti-GITR immunogenicity may not necessarily impact the pharmacology of coadministered monoclonal antibodies, supporting combination immunomodulatory strategies. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  20. Epitope mapping and characterization of a novel CD4-induced human monoclonal antibody capable of neutralizing primary HIV-1 strains

    International Nuclear Information System (INIS)

    Xiang Shihua; Wang Liping; Abreu, Mariam; Huang, C.-C.; Kwong, Peter D.; Rosenberg, Eric; Robinson, James E.; Sodroski, Joseph

    2003-01-01

    Human immunodeficiency virus (HIV-1) enters target cells by binding its gp120 exterior envelope glycoprotein to CD4 and one of the chemokine receptors, CCR5 or CXCR4. CD4-induced (CD4i) antibodies bind gp120 more efficiently after CD4 binding and block the interaction with the chemokine receptor. Examples of CD4i antibodies are limited, and the prototypes of the CD4i antibodies exhibit only weak neutralizing activity against primary, clinical HIV-1 isolates. Here we report the identification of a novel antibody, E51, that exhibits CD4-induced binding to gp120 and neutralizes primary HIV-1 more efficiently than the prototypic CD4i antibodies. The E51 antibody blocks the interaction of gp120-CD4 complexes with CCR5 and binds to a highly conserved, basic gp120 element composed of the β19-strand and surrounding structures. Thus, on primary HIV-1 isolates, this gp120 region, which has been previously implicated in chemokine receptor binding, is accessible to a subset of CD4i antibodies

  1. G-CSF/anti-G-CSF antibody complexes drive the potent recovery and expansion of CD11b+Gr-1+ myeloid cells without compromising CD8+ T cell immune responses

    Science.gov (United States)

    2013-01-01

    Background Administration of recombinant G-CSF following cytoreductive therapy enhances the recovery of myeloid cells, minimizing the risk of opportunistic infection. Free G-CSF, however, is expensive, exhibits a short half-life, and has poor biological activity in vivo. Methods We evaluated whether the biological activity of G-CSF could be improved by pre-association with anti-G-CSF mAb prior to injection into mice. Results We find that the efficacy of G-CSF therapy can be enhanced more than 100-fold by pre-association of G-CSF with an anti-G-CSF monoclonal antibody (mAb). Compared with G-CSF alone, administration of G-CSF/anti-G-CSF mAb complexes induced the potent expansion of CD11b+Gr-1+ myeloid cells in mice with or without concomitant cytoreductive treatment including radiation or chemotherapy. Despite driving the dramatic expansion of myeloid cells, in vivo antigen-specific CD8+ T cell immune responses were not compromised. Furthermore, injection of G-CSF/anti-G-CSF mAb complexes heightened protective immunity to bacterial infection. As a measure of clinical value, we also found that antibody complexes improved G-CSF biological activity much more significantly than pegylation. Conclusions Our findings provide the first evidence that antibody cytokine complexes can effectively expand myeloid cells, and furthermore, that G-CSF/anti-G-CSF mAb complexes may provide an improved method for the administration of recombinant G-CSF. PMID:24279871

  2. Compartmental and dosimetric studies of anti-CD20 labeled with 188Re

    International Nuclear Information System (INIS)

    Barrio Kuramoto Graciela; Mie Nakamura Matsuda Margareth; Osso Joao Jr, Alberto

    2016-01-01

    Radioimmunotherapy has the potential to deliver lethal radiation energy directly to malignant cells via targeting of radioisotope-conjugated monoclonal antibodies (MAbs) to specific antigens. Rituximab (RTX) is specifically targeted against CD20, a surface antigen expressed by B-lymphocytes. The use of 188 Re from a 188 W/ 188 Re generator system represents an alternative radionuclide for therapy. Rhenium has chemical properties similar to technetium and both can be conjugated to antibodies using similar chemistry methods. The objective of this work is to prove the usefulness of this radiopharmaceutical based on dosimetric and pharmacokinetic studies that are also required by the Brazilian Regulatory Agency. (author)

  3. Co-association of methotrexate and SPIONs into anti-CD64 antibody-conjugated PLGA nanoparticles for theranostic application

    Directory of Open Access Journals (Sweden)

    Moura CC

    2014-10-01

    Full Text Available Catarina Costa Moura,1,2 Marcela A Segundo,1 José das Neves,3,4 Salette Reis,1 Bruno Sarmento3,4 1REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal; 2Faculty of Engineering, University of Porto, Porto, Portugal; 3CESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Instituto de Ciências da Saúde-Norte, Gandra PRD, Portugal; 4INEB – Instituto de Engenharia Biomédica, University of Porto, Porto, Portugal Background: Rheumatoid arthritis (RA is an autoimmune disease with severe consequences for the quality of life of sufferers. Regrettably, the inflammatory process involved remains unclear, and finding successful therapies as well as new means for its early diagnosis have proved to be daunting tasks. As macrophages are strongly associated with RA inflammation, effective diagnosis and therapy may encompass the ability to target these cells. In this work, a new approach for targeted therapy and imaging of RA was developed based on the use of multifunctional polymeric nanoparticles. Methods: Poly(lactic-co-glycolic acid nanoparticles were prepared using a single emulsion-evaporation method and comprised the co-association of superparamagnetic iron oxide nanoparticles (SPIONs and methotrexate. The nanoparticles were further functionalized with an antibody against the macrophage-specific receptor, CD64, which is overexpressed at sites of RA. The devised nanoparticles were characterized for mean particle size, polydispersity index, zeta potential, and morphology, as well as the association of SPIONs, methotrexate, and the anti-CD64 antibody. Lastly, the cytotoxicity of the developed nanoparticles was assessed in RAW 264.7 cells using standard MTT and LDH assays.Results: The nanoparticles had a mean diameter in the range of 130–200 nm and zeta potential values ranging from -32 mV to -16 mV. Association with either methotrexate or SPIONs did not

  4. Monoclonal Antibodies 13A4 and AC133 Do Not Recognize the Canine Ortholog of Mouse and Human Stem Cell Antigen Prominin-1 (CD133.

    Directory of Open Access Journals (Sweden)

    Kristina Thamm

    Full Text Available The pentaspan membrane glycoprotein prominin-1 (CD133 is widely used in medicine as a cell surface marker of stem and cancer stem cells. It has opened new avenues in stem cell-based regenerative therapy and oncology. This molecule is largely used with human samples or the mouse model, and consequently most biological tools including antibodies are directed against human and murine prominin-1. Although the general structure of prominin-1 including its membrane topology is conserved throughout the animal kingdom, its primary sequence is poorly conserved. Thus, it is unclear if anti-human and -mouse prominin-1 antibodies cross-react with their orthologs in other species, especially dog. Answering this issue is imperative in light of the growing number of studies using canine prominin-1 as an antigenic marker. Here, we address this issue by cloning the canine prominin-1 and use its overexpression as a green fluorescent protein fusion protein in Madin-Darby canine kidney cells to determine its immunoreactivity with antibodies against human or mouse prominin-1. We used immunocytochemistry, flow cytometry and immunoblotting techniques and surprisingly found no cross-species immunoreactivity. These results raise some caution in data interpretation when anti-prominin-1 antibodies are used in interspecies studies.

  5. Anti-influenza M2e antibody

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM

    2011-12-20

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

  6. Effectiveness of slow-release systems in CD40 agonistic antibody immunotherapy of cancer

    NARCIS (Netherlands)

    Fransen, Marieke F.; Cordfunke, Robert A.; Sluijter, Marjolein; Van Steenbergen, Mies J.; Drijfhout, Jan W.; Ossendorp, Ferry; Hennink, Wim E.; Melief, Cornelis J M

    2014-01-01

    Slow-release delivery has great potential for specifically targeting immune-modulating agents into the tumor-draining area. In prior work we showed that local treatment of slowly delivered anti-CD40 antibody induced robust anti-tumor CD8+ T cell responses without systemic toxicity. We now report on

  7. Clinical application of antibody monoclonal humanized anti-EGFrnimotuzumab labeled

    International Nuclear Information System (INIS)

    Perera Pintado, Alejandro; Peña Quián, Yamilé; Batista Cuéllar, Juan F.; Prats Capote, Anaís; Torres Aroche, Leonel A.; Casacó Santana, Caridad; Sánchez Mendosa, Elvia L.; Sánchez González, Yolaine; Romero Collado, Susana; Quesada Pozo, Rodobaldo; Valladares Oviedo, Lourdes; Masquida García, Elsa M.; Leyva Montaña, René; Casacó, Angel; Ramos Suzarte, Mayra; Crombet, Tania

    2016-01-01

    Most malignant tumors are of epithelial origin. These are characterized by overexpression of the receptor of epidermal growth factor (EGFR), which the neoplastic cells escape the regulatory mechanisms are allowed, so its high concentration of membrane is generally associated with a poor prognosis . By binding an antibody specifically to this receptor, preventing binding of EGF latter and activation mechanism tyrosine kinase inhibiting cell mitosis and apoptosis causing tumor cell. For this reason, the EGFr has been considered as an attractive target for anti-tumor therapy. The humanized monoclonal antibody anti-EGFr nimotuzumab was developed by the Center of Molecular Immunology (Havana, Cuba). Numerous clinical trials have been developed in the Department of Clinical Research Center Isotopes (Cuba), in which it has been applied this antibody, both labeled with 99mTc for immuno gammagraphic detection of tumors, as labeled with 188 Re for radioimmunotherapy of gliomas high degree of malignancy. The aim of this paper is to show the experience of the Department of Clinical Research of CENTIS in various clinical trials with marking for both immuno gammagraphics detection of tumors, such as for radioimmunotherapy nimotuzumab. (author)

  8. Antibody-mediated phagocytosis contributes to the anti-tumor activity of the therapeutic antibody daratumumab in lymphoma and multiple myeloma

    DEFF Research Database (Denmark)

    Overdijk, M. B.; Verploegen, S.; Bogels, M.

    2015-01-01

    Daratumumab (DARA) is a human CD38-specific IgG1 antibody that is in clinical development for the treatment of multiple myeloma (MM). The potential for IgG1 antibodies to induce macrophage-mediated phagocytosis, in combination with the known presence of macrophages in the tumor microenvironment...... in MM and other hematological tumors, led us to investigate the contribution of antibody-dependent, macrophage-mediated phagocytosis to DARA's mechanism of action. Live cell imaging revealed that DARA efficiently induced macrophage-mediated phagocytosis, in which individual macrophages rapidly...... and sequentially engulfed multiple tumor cells. DARA-dependent phagocytosis by mouse and human macrophages was also observed in an in vitro flow cytometry assay, using a range of MM and Burkitt's lymphoma cell lines. Phagocytosis contributed to DARA's anti-tumor activity in vivo, in both a subcutaneous...

  9. A murine monoclonal anti-idiotypic antibody detects a common idiotope on human, mouse and rabbit antibodies to allergen Lol p IV.

    Science.gov (United States)

    Zhou, E M; Dzuba-Fischer, J M; Rector, E S; Sehon, A H; Kisil, F T

    1991-09-01

    A syngeneic mouse monoclonal anti-idiotypic antibody (anti-Id), designated as B1/1, was generated against a monoclonal antibody (MoAb 91) specific for Ryegrass pollen allergen Lol p IV. This anti-Id recognized an idiotope (Id) that was also present on other monoclonal antibodies with the same specificity as MoAb 91. Observations that (i) the anti-Id inhibited the binding of MoAb 91 to Lol p IV and (ii) the Id-anti-Id interaction could be inhibited by Lol p IV indicated that the Id was located within or near the antigen combining site. These properties served to characterize B1/1 as an internal image anti-Id. Evidence that an immune response in different species to Lol p IV elicits the formation of antibodies which express a common Id was provided by the observations that (i) the Id-anti-Id interactions could be inhibited by mouse, human and rabbit antisera to Lol p IV and (ii) the binding of these antisera to Lol p IV could be inhibited by the anti-Id. Interestingly, the internal image anti-Id B1/1 also recognized an Id on a monoclonal antibody which was directed to an epitope of Lol p IV, different from that recognized by MoAb 91.

  10. The identification of irreversible rituximab-resistant lymphoma caused by CD20 gene mutations

    Energy Technology Data Exchange (ETDEWEB)

    Mishima, Y [Department of Clinical Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan); Olympas Bio-Imaging Lab, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan); Terui, Y [Department of Clinical Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan); Takeuchi, K [Division of Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo (Japan); Matsumoto-Mishima, Y; Matsusaka, S [Department of Clinical Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan); Utsubo-Kuniyoshi, R [Department of Clinical Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan); Olympas Bio-Imaging Lab, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan); Hatake, K [Department of Clinical Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo (Japan)

    2011-04-01

    C-terminal mutations of CD20 constitute part of the mechanisms that resist rituximab therapy. Most CD20 having a C-terminal mutation was not recognized by L26 antibody. As the exact epitope of L26 has not been determined, expression and localization of mutated CD20 have not been completely elucidated. In this study, we revealed that the binding site of L26 monoclonal antibody is located in the C-terminal cytoplasmic region of CD20 molecule, which was often lost in mutated CD20 molecules. This indicates that it is difficult to distinguish the mutation of CD20 from under expression of the CD20 protein. To detect comprehensive CD20 molecules including the resistant mutants, we developed a novel monoclonal antibody that recognizes the N-terminal cytoplasm region of CD20 molecule. We screened L26-negative cases with our antibody and found several mutations. A rituximab-binding analysis using the cryopreserved specimen that mutation was identified in CD20 molecules indicated that the C-terminal region of CD20 undertakes a critical role in presentation of the large loop in which the rituximab-binding site locates. Thus, combination of antibodies of two kinds of epitope permits the identification of C-terminal CD20 mutations associated with irreversible resistance to rituximab and may help the decision of the treatment strategy.

  11. A human cytochrome P-450 is recognized by anti-liver/kidney microsome antibodies in autoimmune chronic hepatitis.

    Science.gov (United States)

    Kiffel, L; Loeper, J; Homberg, J C; Leroux, J P

    1989-02-28

    1- Anti-liver/kidney microsome autoantibodies type 1 (anti-LKM1), observed in some children with chronic active hepatitis, were used to isolate their antigen in human liver microsomes. A protein, called P-LKM1 was thus purified. This protein was recognized by a rabbit antiserum directed against the related human cytochromes P-450 bufI and P-450 bufII. 2- A human liver microsomal protein immunoprecipitated with anti-LKM1 sera was also recognized by anti cytochromes P-450 bufI/II antibodies. 3- Anti-LKM1 antibodies potently inhibited microsomal bufuralol 1'-hydroxylation. These results displayed the possible identity between cytochrome P-450 bufI/II and LKM1 antigen.

  12. Unique biological properties of catalytic domain directed human anti-CAIX antibodies discovered through phage-display technology.

    Directory of Open Access Journals (Sweden)

    Chen Xu

    2010-03-01

    Full Text Available Carbonic anhydrase IX (CAIX, gene G250/MN-encoded transmembrane protein is highly expressed in various human epithelial tumors such as renal clear cell carcinoma (RCC, but absent from the corresponding normal tissues. Besides the CA signal transduction activity, CAIX may serve as a biomarker in early stages of oncogenesis and also as a reliable marker of hypoxia, which is associated with tumor resistance to chemotherapy and radiotherapy. Although results from preclinical and clinical studies have shown CAIX as a promising target for detection and therapy for RCC, only a limited number of murine monoclonal antibodies (mAbs and one humanized mAb are available for clinical testing and development. In this study, paramagnetic proteoliposomes of CAIX (CAIX-PMPLs were constructed and used for anti-CAIX antibody selection from our 27 billion human single-chain antibody (scFv phage display libraries. A panel of thirteen human scFvs that specifically recognize CAIX expressed on cell surface was identified, epitope mapped primarily to the CA domain, and affinity-binding constants (KD determined. These human anti-CAIX mAbs are diverse in their functions including induction of surface CAIX internalization into endosomes and inhibition of the carbonic anhydrase activity, the latter being a unique feature that has not been previously reported for anti-CAIX antibodies. These human anti-CAIX antibodies are important reagents for development of new immunotherapies and diagnostic tools for RCC treatment as well as extending our knowledge on the basic structure-function relationships of the CAIX molecule.

  13. Immunocapture of CD133-positive cells from human cancer cell lines by using monodisperse magnetic poly(glycidyl methacrylate) microspheres containing amino groups

    Energy Technology Data Exchange (ETDEWEB)

    Kuan, Wei-Chih [Department of Chemical Engineering, Systems Biology and Tissue Engineering Research Center, National Chung Cheng University, Minhisung 621, Taiwan (China); Horák, Daniel, E-mail: horak@imc.cas.cz [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6 (Czech Republic); Plichta, Zdeněk [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6 (Czech Republic); Lee, Wen-Chien [Department of Chemical Engineering, Systems Biology and Tissue Engineering Research Center, National Chung Cheng University, Minhisung 621, Taiwan (China)

    2014-01-01

    Magnetic poly(glycidyl methacrylate)-based macroporous microspheres with an average particle size of 4.2 μm were prepared using a modified multi-step swelling polymerization method and by introducing amino functionality on their surfaces. Antibody molecules were oxidized on their carbohydrate moieties and bound to the amino-containing magnetic microspheres via a site-directed procedure. CD133-positive cells could be effectively captured from human cancer cell lines (HepG2, HCT116, MCF7, and IMR-32) by using magnetic microspheres conjugated to an anti-human CD133 antibody. After further culture, the immunocaptured CD133-expressing cells from IMR-32 proliferated and gradually detached from the magnetic microspheres. Flow-cytometric analysis confirmed the enrichment of CD133-expressing cells by using the antibody-bound magnetic microspheres. Such microspheres suitable for immunocapture are very promising for cancer diagnosis because the CD133-expressing cells in cancer cell lines have been suggested to be cancer stem cells. - Highlights: • Multi-step swelling polymerization produced poly(glycidyl methacrylate) microspheres. • Anti-human CD133 antibodies were bound to the amino-containing magnetic microspheres. • CD133-positive cells were effectively captured from human cancer cell lines. • Immunocaptured CD133-expressing cells proliferated and were detached from microspheres. • Enrichment of CD133-expressing cells was confirmed by flow-cytometric analysis.

  14. CD14(hi)CD16+ monocytes phagocytose antibody-opsonised Plasmodium falciparum infected erythrocytes more efficiently than other monocyte subsets, and require CD16 and complement to do so.

    Science.gov (United States)

    Zhou, Jingling; Feng, Gaoqian; Beeson, James; Hogarth, P Mark; Rogerson, Stephen J; Yan, Yan; Jaworowski, Anthony

    2015-07-07

    With more than 600,000 deaths from malaria, mainly of children under five years old and caused by infection with Plasmodium falciparum, comes an urgent need for an effective anti-malaria vaccine. Limited details on the mechanisms of protective immunity are a barrier to vaccine development. Antibodies play an important role in immunity to malaria and monocytes are key effectors in antibody-mediated protection by phagocytosing antibody-opsonised infected erythrocytes (IE). Eliciting antibodies that enhance phagocytosis of IE is therefore an important potential component of an effective vaccine, requiring robust assays to determine the ability of elicited antibodies to stimulate this in vivo. The mechanisms by which monocytes ingest IE and the nature of the monocytes which do so are unknown. Purified trophozoite-stage P. falciparum IE were stained with ethidium bromide, opsonised with anti-erythrocyte antibodies and incubated with fresh whole blood. Phagocytosis of IE and TNF production by individual monocyte subsets was measured by flow cytometry. Ingestion of IE was confirmed by imaging flow cytometry. CD14(hi)CD16+ monocytes phagocytosed antibody-opsonised IE and produced TNF more efficiently than CD14(hi)CD16- and CD14(lo)CD16+ monocytes. Blocking experiments showed that Fcγ receptor IIIa (CD16) but not Fcγ receptor IIa (CD32a) or Fcγ receptor I (CD64) was necessary for phagocytosis. CD14(hi)CD16+ monocytes ingested antibody-opsonised IE when peripheral blood mononuclear cells were reconstituted with autologous serum but not heat-inactivated autologous serum. Antibody-opsonised IE were rapidly opsonised with complement component C3 in serum (t1/2 = 2-3 minutes) and phagocytosis of antibody-opsonised IE was inhibited in a dose-dependent manner by an inhibitor of C3 activation, compstatin. Compared to other monocyte subsets, CD14(hi)CD16+ monocytes expressed the highest levels of complement receptor 4 (CD11c) and activated complement receptor 3 (CD11b) subunits

  15. Anti-human tissue factor antibody ameliorated intestinal ischemia reperfusion-induced acute lung injury in human tissue factor knock-in mice.

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    Xiaolin He

    Full Text Available BACKGROUND: Interaction between the coagulation and inflammation systems plays an important role in the development of acute respiratory distress syndrome (ARDS. Anti-coagulation is an attractive option for ARDS treatment, and this has promoted development of new antibodies. However, preclinical trials for these antibodies are often limited by the high cost and availability of non-human primates. In the present study, we developed a novel alternative method to test the role of a humanized anti-tissue factor mAb in acute lung injury with transgenic mice. METHODOLOGY/PRINCIPAL FINDINGS: Human tissue factor knock-in (hTF-KI transgenic mice and a novel humanized anti-human tissue factor mAb (anti-hTF mAb, CNTO859 were developed. The hTF-KI mice showed a normal and functional expression of hTF. The anti-hTF mAb specifically blocked the pro-coagulation activity of brain extracts from the hTF-KI mice and human, but not from wild type mice. An extrapulmonary ARDS model was used by intestinal ischemia-reperfusion. Significant lung tissue damage in hTF-KI mice was observed after 2 h reperfusion. Administration of CNTO859 (5 mg/kg, i.v. attenuated the severity of lung tissue injury, decreased the total cell counts and protein concentration in bronchoalveolar lavage fluid, and reduced Evans blue leakage. In addition, the treatment significantly reduced alveolar fibrin deposition, and decreased tissue factor and plasminogen activator inhibitor-1 activity in the serum. This treatment also down-regulated cytokine expression and reduced cell death in the lung. CONCLUSIONS: This novel anti-hTF antibody showed beneficial effects on intestinal ischemia-reperfusion induced acute lung injury, which merits further investigation for clinical usage. In addition, the use of knock-in transgenic mice to test the efficacy of antibodies against human-specific proteins is a novel strategy for preclinical studies.

  16. Beyond CDR-grafting: Structure-guided humanization of framework and CDR regions of an anti-myostatin antibody.

    Science.gov (United States)

    Apgar, James R; Mader, Michelle; Agostinelli, Rita; Benard, Susan; Bialek, Peter; Johnson, Mark; Gao, Yijie; Krebs, Mark; Owens, Jane; Parris, Kevin; St Andre, Michael; Svenson, Kris; Morris, Carl; Tchistiakova, Lioudmila

    2016-10-01

    Antibodies are an important class of biotherapeutics that offer specificity to their antigen, long half-life, effector function interaction and good manufacturability. The immunogenicity of non-human-derived antibodies, which can be a major limitation to development, has been partially overcome by humanization through complementarity-determining region (CDR) grafting onto human acceptor frameworks. The retention of foreign content in the CDR regions, however, is still a potential immunogenic liability. Here, we describe the humanization of an anti-myostatin antibody utilizing a 2-step process of traditional CDR-grafting onto a human acceptor framework, followed by a structure-guided approach to further reduce the murine content of CDR-grafted antibodies. To accomplish this, we solved the co-crystal structures of myostatin with the chimeric (Protein Databank (PDB) id 5F3B) and CDR-grafted anti-myostatin antibody (PDB id 5F3H), allowing us to computationally predict the structurally important CDR residues as well as those making significant contacts with the antigen. Structure-based rational design enabled further germlining of the CDR-grafted antibody, reducing the murine content of the antibody without affecting antigen binding. The overall "humanness" was increased for both the light and heavy chain variable regions.

  17. Simple and efficient generation of virus-specific T cells for adoptive therapy using anti-4-1BB antibody.

    Science.gov (United States)

    Imahashi, Nobuhiko; Nishida, Tetsuya; Goto, Tatsunori; Terakura, Seitaro; Watanabe, Keisuke; Hanajiri, Ryo; Sakemura, Reona; Imai, Misa; Kiyoi, Hitoshi; Naoe, Tomoki; Murata, Makoto

    2015-01-01

    Although recent studies of virus-specific T-cell (VST) therapy for viral infections after allogeneic hematopoietic stem cell transplantation have shown promising results, simple and less time-intensive and labor-intensive methods are required to generate VSTs for the wider application of VST therapy. We investigated the efficacy of anti-CD28 and anti-4-1BB antibodies, which can provide T cells with costimulatory signals similar in strength to those of antigen-presenting cells, in generating VSTs. When peripheral blood mononuclear cells were stimulated with viral peptides together with isotype control, anti-CD28, or anti-4-1BB antibodies, anti-4-1BB antibodies yielded the highest numbers of VSTs, which were on an average 7.9 times higher than those generated with isotype control antibody. The combination of anti-CD28 and anti-4-1BB antibodies did not result in increased numbers of VSTs compared with anti-4-1BB antibody alone. Importantly, the positive effect of anti-4-1BB antibody was observed regardless of the epitopes of the VSTs. In contrast, the capacity of dendritic cells (DCs) to generate VSTs differed considerably depending on the epitopes of the VSTs. Furthermore, the numbers of VSTs generated with DCs were at most similar to those generated with the anti-4-1BB antibody. Generation of VSTs with anti-4-1BB antibody did not result in excessive differentiation or deteriorated function of the generated VSTs compared with those generated with control antibody or DCs. In conclusion, VSTs can be generated rapidly and efficiently by simply stimulating peripheral blood mononuclear cells with viral peptide and anti-4-1BB antibody without using antigen-presenting cells. We propose using anti-4-1BB antibody as a novel strategy to generate VSTs for adoptive therapy.

  18. A simple method for assessment of human anti-Neu5Gc antibodies applied to Kawasaki disease.

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    Vered Padler-Karavani

    Full Text Available N-glycolylneuraminic acid (Neu5Gc is an immunogenic sugar of dietary origin that metabolically incorporates into diverse native glycoconjugates in humans. Anti-Neu5Gc antibodies are detected in all human sera, though with variable levels and epitope-recognition profiles. These antibodies likely play a role in several inflammation-mediated pathologies including cardiovascular diseases and cancer. In cancer, they have dualistic and opposing roles, either stimulating or repressing disease, as a function of their dose, and some of these antibodies serve as carcinoma biomarkers. Thus, anti-Neu5Gc antibodies may signify risk of inflammation-mediated diseases, and changes in their levels could potentially be used to monitor disease progression and/or response to therapy. Currently, it is difficult to determine levels of anti-Neu5Gc antibodies in individual human samples because these antibodies recognize multiple Neu5Gc-epitopes. Here we describe a simple and specific method for detection and overall estimation of human anti-Neu5Gc antibodies. We exploit the difference between two mouse models that differ only by Neu5Gc-presence (wild-type or Neu5Gc-absence (Cmah(-/- knockout. We characterize mouse serum from both strains by HPLC, lectin and mass-spectrometry analysis and show the target Neu5Gc-epitopes. We then use Cmah(-/- knockout sera to inhibit all non-Neu5Gc-reactivity followed by binding to wild-type sera to detect overall anti-Neu5Gc response in a single assay. We applied this methodology to characterize and quantify anti-Neu5Gc IgG and IgA in sera of patients with Kawasaki disease (KD at various stages compared to controls. KD is an acute childhood febrile disease characterized by inflammation of coronary arteries that untreated may lead to coronary artery aneurysms with risk of thrombosis and myocardial infarction. This estimated response is comparable to the average of detailed anti-Neu5Gc IgG profile analyzed by a sialoglycan microarray

  19. Transient human anti-mouse antibodies (HAMA) interference in CA 125 measurements during monitoring of ovarian cancer patients treated with murine monoclonal antibody.

    NARCIS (Netherlands)

    Oei, A.L.M.; Sweep, F.C.; Massuger, L.F.A.G.; Olthaar, A.J.; Thomas, C.M.G.

    2008-01-01

    OBJECTIVE: To investigate the influence of human anti-mouse antibodies (HAMA) on serial CA 125 measurements in serum of patients with epithelial ovarian cancer following single intraperitoneal (IP) therapy with Yttrium-90-labeled human milk fat globule 1 murine monoclonal antibody ((90)Y-muHMFG1) as

  20. Analysis of anti-HLA antibodies in sensitized kidney transplant candidates subjected to desensitization with intravenous immunoglobulin and rituximab.

    Science.gov (United States)

    Lobashevsky, Andrew L; Higgins, Nancy G; Rosner, Kevin M; Mujtaba, Muhammad A; Goggins, William C; Taber, Tim E

    2013-07-27

    Preexisting donor-specific antibodies against human leukocyte antigens are major risk factors for acute antibody-mediated and chronic rejection of kidney transplant grafts. Immunomodulation (desensitization) protocols may reduce antibody concentration and improve the success of transplant. We investigated the effect of desensitization with intravenous immunoglobulin and rituximab on the antibody profile in highly sensitized kidney transplant candidates. In 31 transplant candidates (calculated panel-reactive antibody [cPRA], 34%-99%), desensitization included intravenous immunoglobulin on days 0 and 30 and a single dose of rituximab on day 15. Anti-human leukocyte antigen antibodies were analyzed before and after desensitization. Reduction of cPRA from 25% to 50% was noted for anti-class I (5 patients, within 20-60 days) and anti-class II (3 patients, within 10-20 days) antibodies. After initial reduction of cPRA, the cPRA increased within 120 days. In 24 patients, decrease in mean fluorescence intensity of antibodies by more than 50% was noted at follow-up, but there was no reduction of cPRA. Rebound occurred in 65% patients for anti-class I antibodies at 350 days and anti-class II antibodies at 101 to 200 days. Probability of rebound effect was higher in patients with mean fluorescence intensity of more than 10,700 before desensitization, anti-class II antibodies, and history of previous transplant. The desensitization protocol had limited efficacy in highly sensitized kidney transplant candidate because of the short period with antibody reduction and high frequency of rebound effect.

  1. [Regulatory B cells activated by CpG-ODN combined with anti-CD40 monoclonal antibody inhibit CD4(+)T cell proliferation].

    Science.gov (United States)

    Wang, Keng; Tao, Lei; Su, Jianbing; Zhang, Yueyang; Zou, Binhua; Wang, Yiyuan; Li, Xiaojuan

    2016-09-01

    Objective To observe the immunosuppressive function of regulatory B cells (Bregs) in vitro after activated by CpG oligodeoxynucleotide (CpG-ODN) and anti-CD40 mAb. Methods Mice splenic CD5(+)CD1d(high)B cells and CD5(-)CD1d(low)B cells were sorted by flow cytometry. These B cells were first stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours, and then co-cultured with purified CD4(+)T cells. The interleukin 10 (IL-10) expression in the activated Bregs and other B cell subset, as well as the proliferation and interferon γ (IFN-γ) expression in the CD4(+) T cells activated by anti-CD3 mAb plus anti-CD28 mAb were determined by flow cytometry. Results CD5(+)CD1d(high) B cells activated by CpG-ODN plus anti-CD40 mAb blocked the up-regulated CD4(+)T proliferation and significantly reduced the IFN-γ level. At the same time, activated CD5(-)CD1d(low)B cells showed no inhibitory effect on CD4(+)T cells. Further study revealed that IL-10 expression in the CD5(+)CD1d(high) B cells were much higher than that in the CD5(-)CD1d(low)B cells after stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours. Conclusion CD5(+)CD1d(high) B cells activated by CpG-ODN combined with anti-CD40 mAb have immune inhibitory effects on CD4(+)T cell activation in vitro , which possibly due to IL-10 secretion.

  2. Membranous Nephropathy and Anti-Podocytes Antibodies: Implications for the Diagnostic Workup and Disease Management.

    Science.gov (United States)

    Pozdzik, Agnieszka; Brochériou, Isabelle; David, Cristina; Touzani, Fahd; Goujon, Jean Michel; Wissing, Karl Martin

    2018-01-01

    The discovery of circulating antibodies specific for native podocyte antigens has transformed the diagnostic workup and greatly improved management of idiopathic membranous nephropathy (iMN). In addition, their identification has clearly characterized iMN as a largely autoimmune disorder. Anti-PLA2R1 antibodies are detected in approximately 70% to 80% and anti-THSD7A antibodies in only 2% of adult patients with iMN. The presence of anti-THSD7A antibodies is associated with increased risk of malignancy. The assessment of PLA2R1 and THSD7A antigen expression in glomerular immune deposits has a better sensitivity than measurement of the corresponding autoantibodies. Therefore, in the presence of circulating anti-podocytes autoantibodies and/or enhanced expression of PLA2R1 and THSD7A antigens MN should be considered as primary MN (pMN). Anti-PLA2R1 or anti-THSD7A autoantibodies have been proposed as biomarkers of autoimmune disease activity and their blood levels should be regularly monitored in pMN to evaluate disease activity and predict outcomes. We propose a revised clinical workup flow for patients with MN that recommends assessment of kidney biopsy for PLA2R1 and THSD7A antigen expression, screening for circulating anti-podocytes antibodies, and assessment for secondary causes, especially cancer, in patients with THSD7A antibodies. Persistence of anti-podocyte antibodies for 6 months or their increase in association with nephrotic proteinuria should lead to the introduction of immunosuppressive therapies. Recent data have reported the efficacy and safety of new specific therapies targeting B cells (anti-CD20 antibodies, inhibitors of proteasome) in pMN which should lead to an update of currently outdated treatment guidelines.

  3. Memory B cells and CD8⁺ lymphocytes do not control seasonal influenza A virus replication after homologous re-challenge of rhesus macaques.

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    Timothy D Carroll

    Full Text Available This study sought to define the role of memory lymphocytes in the protection from homologous influenza A virus re-challenge in rhesus macaques. Depleting monoclonal antibodies (mAb were administered to the animals prior to their second experimental inoculation with a human seasonal influenza A virus strain. Treatment with either anti-CD8α or anti-CD20 mAbs prior to re-challenge had minimal effect on influenza A virus replication. Thus, in non-human primates with pre-existing anti-influenza A antibodies, memory B cells and CD8α⁺ T cells do not contribute to the control of virus replication after re-challenge with a homologous strain of influenza A virus.

  4. Increased T cell proliferative responses to islet antigens identify clinical responders to anti-CD20 monoclonal antibody (rituximab) therapy in type 1 diabetes.

    Science.gov (United States)

    Herold, Kevan C; Pescovitz, Mark D; McGee, Paula; Krause-Steinrauf, Heidi; Spain, Lisa M; Bourcier, Kasia; Asare, Adam; Liu, Zhugong; Lachin, John M; Dosch, H Michael

    2011-08-15

    Type 1 diabetes mellitus is believed to be due to the autoimmune destruction of β-cells by T lymphocytes, but a single course of rituximab, a monoclonal anti-CD20 B lymphocyte Ab, can attenuate C-peptide loss over the first year of disease. The effects of B cell depletion on disease-associated T cell responses have not been studied. We compare changes in lymphocyte subsets, T cell proliferative responses to disease-associated target Ags, and C-peptide levels of participants who did (responders) or did not (nonresponders) show signs of β-cell preservation 1 y after rituximab therapy in a placebo-controlled TrialNet trial. Rituximab decreased B lymphocyte levels after four weekly doses of mAb. T cell proliferative responses to diabetes-associated Ags were present at baseline in 75% of anti-CD20- and 82% of placebo-treated subjects and were not different over time. However, in rituximab-treated subjects with significant C-peptide preservation at 6 mo (58%), the proliferative responses to diabetes-associated total (p = 0.032), islet-specific (p = 0.048), and neuronal autoantigens (p = 0.005) increased over the 12-mo observation period. This relationship was not seen in placebo-treated patients. We conclude that in patients with type 1 diabetes mellitus, anti-B cell mAb causes increased proliferative responses to diabetes Ags and attenuated β-cell loss. The way in which these responses affect the disease course remains unknown.

  5. Study of chronic hemolytic anaemia patients in Rio de Janeiro: prevalence of anti-human parvovirus B19 IgG antibodies and the developement aplastic crises

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    SANT'ANNA Anadayr L.M.

    2002-01-01

    Full Text Available The prevalence of anti-human parvovirus B19 IgG antibodies was determined in sera from 165 chronic hemolytic anemia patients, receiving medical care at Instituto Estadual de Hematologia (IEHE, Rio de Janeiro, during the year of 1994. This sample represents around 10% of the chronic hemolytic anemia patients attending at IEHE. Most of these patients (140 have sickle cell disease. Anti-B19 IgG antibodies were detected in 32.1% of patients. No statistically significant difference (p > 0.05 was seen between IgG antibody prevalence in male (27.8% and female (35.5% patients. Anti-B19 IgG antibodies were more frequent in older (37.6% than younger (28.2% than 20 years old patients, although this difference had no statistical significance (p > 0.05. Anti-B19 IgG antibody prevalence showed that 67.9% of patients enrolled in the study were susceptible to B19 acute infection. With the aim to detect acute B19 infection, patients follow up continued until February 1996. During this period four patients presented transient aplastic crisis due to human parvovirus B19 as confirmed by the detection of specific IgM antibodies. All four patients were younger than 20 years old, and 3 were younger than 10 years old. Three of them were sickle cell disease patients. Three of the four acute B19 infection occurred during 1994 springtime.

  6. Fusion as a mediator of cytolysis in mixtures of uninfected CD4+ lymphocytes and cells infected by human immunodeficiency virus

    International Nuclear Information System (INIS)

    Yoffe, B.; Lewis, D.E.; Petrie, B.L.; Noonan, C.A.; Melnick, J.L.; Hollinger, F.B.

    1987-01-01

    The authors describe an unusual type of cytopathology in which uninfected CD4 + (helper/inducer) cells (cells expressing the human leukocyte antigen CD4) interact with cells persistently infected with the human immunodeficiency virus (HIV). Prior antigenic stimulation was not required, since CD4 + cells taken either from healthy persons without anti-HIV antibodies or from individuals with anti-HIV antibodies were capable in inducing cytolysis. Neither CD8 + (suppressor/cytotoxic) nor CD16 + (natural killer) cells mediated the reaction. Light microscopic and autoradiographic studies revealed that, prior to cytolysis, multinucleated giant cells were formed from fusions between HIV-infected cells and large numbers of uninfected CD4 + lymphocytes. These data may explain the paradox that exists in vivo in which a dramatic depletion of CD4 + lymphocytes occurs in the presence of a small number of HIV-infected CD4 + cells. These new insights into the pathogenesis of acquired immunodeficiency syndrome (AIDS) may lead to future therapeutic strategies

  7. Isolating Sperm from Cell Mixtures Using Magnetic Beads Coupled with an Anti-PH-20 Antibody for Forensic DNA Analysis.

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    Xing-Chun Zhao

    Full Text Available Vaginal swabs taken in rape cases usually contain epithelial cells from the victim and sperm from the assailant and forensic DNA analysis requires separation of sperm from these cell mixtures. PH-20, which is a glycosylphosphatidylinositol-anchored hyaluronidase located on the head of sperm, has important functions in fertilization. Here we describe a newly developed method for sperm isolation using anti-PH-20 antibody-coupled immunomagnetic beads (anti-PH-20 IMBs. Optical microscopy and scanning electron microscopy showed the IMBs recognized the head of sperm specifically and exhibited a great capacity to capture sperm cells. However, we found it necessary to incubate the IMB-sperm complex with DNase I before sperm lysis in order to remove any female DNA completely. We compared the sensitivity of anti-PH-20 IMBs in sperm and epithelial cell discrimination to those coated with a different anti-sperm antibody (anti-SP-10, anti-ADAM2 or anti-JLP. Only the anti-PH-20 IMBs succeeded in isolating sperm from cell mixtures at a sperm/epithelial cell ratio of 103:105. Further, our method exhibited greater power and better stability for sperm isolation compared to the traditional differential lysis strategy. Taken together, the anti-PH-20 IMB method described here could be effective for the isolation of sperm needed to obtain a single-sourced DNA profile as an aid to identifying the perpetrator in sexual assault cases.

  8. [Preparation and preliminary application of rabbit anti-human PON2 antibodies(paraoxonase-2)].

    Science.gov (United States)

    Chen, Miao; Yang, Jin-Ju; Li, Shu-Zhen; Liu, Xiao-Lan; Liu, Ying; Zhang, Lin-Jie; Gao, Jian-En; Sun, Qi-Hong

    2008-07-01

    To preparation and characterize the rabbit polyclonal antibodies against human PON2 (paraoxonase-2). A fragment of human PON2 gene which was of low homology with rabbits but of higher hydrophilicity and immunogenicity was selected for recombinant expression in prokaryotic expression system. The rabbits were immunized with the purified GST fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 polyclonal antibodies were detected by Western blot and indirect immunofluorescence. The GST-PON2 fusion protein was highly expressed in Ecoli with a molecular weight of 46 kDa. Western blot analysis proved the rabbit polyclonal antibodies could specifically recognize 39 kDa native PON2 protein expressed in several cells and tissues, such as HeLa cells, U937 cells, and human liver tissue. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of SY5Y cells. The rabbit polyclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells and tissues, Which can be used for further study and clinical detection of human PON2.

  9. Presence of anti-Toxoplasma antibodies in humans and their cats in the urban zone of Guadalajara

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    Galván Ramírez María de la Luz

    1999-01-01

    Full Text Available Cats are the definitive hosts of Toxoplasma gondii. Infected cats excrete oocysts in their feces, infecting humans and other animals. The objective of the present study was to determine the presence of anti-Toxoplasma antibodies in cat owners and their pets, and determine if there was a relationship between Toxoplasma infection and humans who live with infected cats. IgG anti-Toxoplasma antibodies in sera of 59 cat owners were determined by enzyme-linked immunosorbent assay (ELISA, in 24 sera from their cats, IgG, IgM, and IgA antibodies were found using Burney's ELISA. Thirty-eight (64% of 59 cat owners were positive to IgG anti-Toxoplasma. Seropositivity for cats was 70.8% IgG, 8.3% IgM, and 62.5% IgA. Cohabitation with cats infected by T. gondii, feeding with leftovers or raw viscera, and lack of control over how their feces were handled are risk factors conducive for humans to become infected by T. gondii.

  10. DNA vaccines expressing soluble CD4-envelope proteins fused to C3d elicit cross-reactive neutralizing antibodies to HIV-1

    International Nuclear Information System (INIS)

    Bower, Joseph F.; Green, Thomas D.; Ross, Ted M.

    2004-01-01

    DNA vaccines expressing the envelope (Env) of the human immunodeficiency virus type 1 (HIV-1) have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies in a variety of animal models. In this study, DNA vaccines were constructed to express a fusion protein of the soluble human CD4 (sCD4) and the gp120 subunit of the HIV-1 envelope. To enhance the immunogenicity of the expressed fusion protein, three copies of the murine C3d (mC3d 3 ) were added to the carboxyl terminus of the complex. Monoclonal antibodies that recognize CD4-induced epitopes on gp120 efficiently bound to sCD4-gp120 or sCD4-gp120-mC3d 3 . In addition, both sCD4-gp120 and sCD4-gp120-mC3d 3 bound to cells expressing appropriate coreceptors in the absence of cell surface hCD4. Mice (BALB/c) vaccinated with DNA vaccines expressing either gp120-mC3d 3 or sCD4-gp120-mC3d 3 elicited antibodies that neutralized homologous virus infection. However, the use of sCD4-gp120-mC3d 3 -DNA elicited the highest titers of neutralizing antibodies that persisted after depletion of anti-hCD4 antibodies. Interestingly, only mice vaccinated with DNA expressing sCD4-gp120-mC3d 3 had antibodies that elicited cross-protective neutralizing antibodies. The fusion of sCD4 to the HIV-1 envelope exposes neutralizing epitopes that elicit broad protective immunity when the fusion complex is coupled with the molecular adjuvant, C3d

  11. Specificity of anti-phospholipid antibodies in infectious mononucleosis: a role for anti-cofactor protein antibodies

    Science.gov (United States)

    Sorice, M; Pittoni, V; Griggi, T; Losardo, A; Leri, O; Magno, M S; Misasi, R; Valesini, G

    2000-01-01

    The antigen specificity of anti-phospholipid antibodies in infectious mononucleosis (IM) was studied using ELISA for the detection of anti-β2-glycoprotein I (β2-GPI), anti-annexin V, anti-protein S and anti-prothrombin antibodies and TLC immunostaining for the detection of anti-phospholipid antibodies. This technique enabled us to look at antibodies reacting to ‘pure’ phospholipid antigens in the absence of protein contamination. Sera from 46 patients with IM, 18 with systemic lupus erythematosus (SLE), 21 with primary anti-phospholipid antibody syndrome (PAPS), 50 with Helicobacter pylori infection and 30 healthy blood donors were tested. This study highlights anti-phospholipid antibodies in patients with IM as specific ‘pure’ anti-cardiolipin antibodies, while in PAPS and SLE patients anti-phosphatidylserine and anti-phosphatidylethanolamine antibodies were also found. This investigation also shows that the anti-cardiolipin antibodies found in IM can be present with anti-cofactor protein antibodies. The higher prevalence of anti-cofactor antibodies found in IM sera than in Helicobacter pylori sera may be due to the immunostimulatory effect and/or the polyclonal activation often observed in course of Epstein–Barr virus infection. However, anti-β2-GPI and, to a lesser extent, anti-prothrombin antibodies occur with a significantly lower prevalence in IM than in PAPS patients. This finding suggests that these antibodies should be regarded as the expression of the broad autoimmune syndrome involving the phospholipid-binding plasma proteins. PMID:10792380

  12. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hugo Amorim dos Santos de Souza

    2017-12-01

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

  15. Detection of anti-tetanus toxoid antibody on modified polyacrylonitrile fibers.

    Science.gov (United States)

    Jain, Swati; Chattopadhyay, Sruti; Jackeray, Richa; Zainul Abid, C K V; Kumar, Manoj; Singh, Harpal

    2010-10-15

    Accurate determination of concentration of immunoglobulin (IgG) to tetanus toxoid is important in order to evaluate the immunogenicity of tetanus toxoid vaccines, immune competence in individual patients and to measure the prevalence of immunity in populations. Surface modified polyacrylonitrile (PAN) fibers were evaluated as a matrix to develop highly sensitive method for the detection of anti-tetanus antibody in a sandwich ELISA format. In the proposed method tetanus toxoid immobilized on modified PAN fibers was used to detect anti-tetanus antibody (raised in horse hence represented as horse anti-tetanus toxoid or HAT-Ab) with horse raddish peroxidase enzyme conjugated with Rabbit anti-Horse IgG (RAH-HRP) as the label within 2.5h. A sigmoidal pattern for the detection of different concentration of antibody ranging from 1.0 to 0.0001 IU mL(-1) was validated. The immunoassay recorded a very high sensitivity as concentration as low as 0.0005 IU mL(-1) of HAT-Ab was detected. The intra- and inter-assay precision for 3 parallel measurements of 0.01 and for 0.001 IU mL(-1) of antibody varied from 5.4% to 11% and 5.7% to 20% respectively. PAN fibers were also used to qualitatively access the presence of different level of anti-tetanus antibody spiked in human blood. Seroepidemiological studies to measure the immunity against tetanus were conducted with twenty-five human beings belonging to various age groups using modified PAN-ELISA. The sensitivity, specificity and the reproducibility of the developed immunoassay indicate the potential application of modified PAN fibers in the field of immunodiagnostics. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. First clinical evaluation of radioimmunoimaging using anti-human lung cancer monoclonal antibodies

    International Nuclear Information System (INIS)

    Zhou Qian

    1991-01-01

    Anti-human large cell lung cancer monoclonal antibodies (McAb) 2E3 and 6D1 were produced in the laboratory. Immunohistochemical studies and radiobinding assay showed these antibodies possessed high specificity against lung cancer cells. 28 patients with lung masses were investigated with 131 I-labeled McAb 6D1 and/or 2E3 scintigraphy. 19 of them were histologically proven and 13 were diagnosed primary lung carcinoma. Radioimmunoimaging visualized 10/13 of the primary lung cancers with a detection rate of 77%. Only 1 case of the non-cancer patients and a false localization, giving a true negative rate of 83%. Pathologically the squamous cell lung carcinoma had the highest localization and the small cell lung carcinoma next, but the detection rate was 100% for both. The adenocarcinoma of lung was less sensitive to these McAbs, with a detection rate of only 33% (1 of 3 cases). We conclude that radioimmunoimaging with anti-human large cell lung cancer McAbs is more specific and effective in detecting primary lung cancers and differentiating lung masses than with antibodies against other tumor associated antigens

  17. Development and Characterization of a Humanized Anti-HER2 Antibody HuA21 with Potent Anti-Tumor Properties in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ruilin Li

    2016-04-01

    Full Text Available Human epidermal growth factor receptor 2 (HER2 is one of the most studied tumor-associated antigens for cancer immunotherapy. An engineered anti-HER-2 chimeric A21 antibody (chA21 is a chimeric antibody targeted to subdomain I of the HER2 extracellular domain. Here, we report the anti-tumor activity of the novel engineered monoclonal antibody humanized chA21 (HuA21 that targets HER2 on the basis of chA21, and we describe the underlying mechanisms. Our results reveal that HuA21 markedly inhibits the proliferation and migration of HER2-overexpressing breast cancer cells and causes enhanced antibody-dependent cell-mediated cytotoxicity potency against HER2-overexpressing tumor cells. In particular, HuA21, but not trastuzumab (Tra, markedly suppresses growth and enhances the internalization of the antibody in Tra-resistant BT-474 breast cancer cells. These characteristics are highly associated with the intrinsic ability of HuA21 to down-regulate HER2 activation and inhibit the extracellular signal-regulated kinase 1/2 (ERK1/2 and protein kinase B (Akt signaling pathways. Furthermore, the combination of HuA21 with Tra synergistically enhances the anti-tumor effects in vitro and in vivo and inhibits HER2 activation and the ERK1/2 and Akt signaling pathways. Altogether, our results suggest that HuA21 may represent a unique anti-HER2 antibody with potential as a therapeutic candidate alone or in combination with other anti-HER2 reagents in cancer therapy.

  18. Identification of relevant drugable targets in diffuse large B-cell lymphoma using a genome-wide unbiased CD20 guilt-by association approach

    NARCIS (Netherlands)

    de Jong, Mathilde R. W.; Visser, Lydia; Huls, Gerwin; Diepstra, Arjan; van Vugt, Marcel; Ammatuna, Emanuele; van Rijn, Rozemarijn S.; Vellenga, Edo; van den Berg, Anke; Fehrmann, Rudolf S. N.; van Meerten, Tom

    2018-01-01

    Forty percent of patients with diffuse large B-cell lymphoma (DLBCL) show resistant disease to standard chemotherapy (CHOP) in combination with the anti-CD20 monoclonal antibody rituximab (R). Although many new anti-cancer drugs were developed in the last years, it is unclear which of these drugs

  19. SGN-CD33A: a novel CD33-targeting antibody-drug conjugate using a pyrrolobenzodiazepine dimer is active in models of drug-resistant AML.

    Science.gov (United States)

    Kung Sutherland, May S; Walter, Roland B; Jeffrey, Scott C; Burke, Patrick J; Yu, Changpu; Kostner, Heather; Stone, Ivan; Ryan, Maureen C; Sussman, Django; Lyon, Robert P; Zeng, Weiping; Harrington, Kimberly H; Klussman, Kerry; Westendorf, Lori; Meyer, David; Bernstein, Irwin D; Senter, Peter D; Benjamin, Dennis R; Drachman, Jonathan G; McEarchern, Julie A

    2013-08-22

    Outcomes in acute myeloid leukemia (AML) remain unsatisfactory, and novel treatments are urgently needed. One strategy explores antibodies and their drug conjugates, particularly those targeting CD33. Emerging data with gemtuzumab ozogamicin (GO) demonstrate target validity and activity in some patients with AML, but efficacy is limited by heterogeneous drug conjugation, linker instability, and a high incidence of multidrug resistance. We describe here the development of SGN-CD33A, a humanized anti-CD33 antibody with engineered cysteines conjugated to a highly potent, synthetic DNA cross-linking pyrrolobenzodiazepine dimer via a protease-cleavable linker. The use of engineered cysteine residues at the sites of drug linker attachment results in a drug loading of approximately 2 pyrrolobenzodiazepine dimers per antibody. In preclinical testing, SGN-CD33A is more potent than GO against a panel of AML cell lines and primary AML cells in vitro and in xenotransplantation studies in mice. Unlike GO, antileukemic activity is observed with SGN-CD33A in AML models with the multidrug-resistant phenotype. Mechanistic studies indicate that the cytotoxic effects of SGN-CD33A involve DNA damage with ensuing cell cycle arrest and apoptotic cell death. Together, these data suggest that SGN-CD33A has CD33-directed antitumor activity and support clinical testing of this novel therapeutic in patients with AML.

  20. Anti-human SIRPα antibody is a new tool for cancer immunotherapy.

    Science.gov (United States)

    Murata, Yoji; Tanaka, Daisuke; Hazama, Daisuke; Yanagita, Tadahiko; Saito, Yasuyuki; Kotani, Takenori; Oldenborg, Per-Arne; Matozaki, Takashi

    2018-02-23

    Interaction of signal regulatory protein α (SIRPα) expressed on the surface of macrophages with its ligand CD47 expressed on target cells negatively regulates phagocytosis of the latter cells by the former. We recently showed that blocking Abs to mouse SIRPα enhanced both the Ab-dependent cellular phagocytosis (ADCP) activity of mouse macrophages for Burkitt's lymphoma Raji cells opsonized with an Ab to CD20 (rituximab) in vitro as well as the inhibitory effect of rituximab on the growth of tumors formed by Raji cells in nonobese diabetic (NOD)/SCID mice. However, the effects of blocking Abs to human SIRPα in preclinical cancer models have remained unclear given that such Abs have failed to interact with endogenous SIRPα expressed on macrophages of immunodeficient mice. With the use of Rag2 -/- γ c -/- mice harboring a transgene for human SIRPα under the control of human regulatory elements (hSIRPα-DKO mice), we here show that a blocking Ab to human SIRPα significantly enhanced the ADCP activity of macrophages derived from these mice for human cancer cells. The anti-human SIRPα Ab also markedly enhanced the inhibitory effect of rituximab on the growth of tumors formed by Raji cells in hSIRPα-DKO mice. Our results thus suggest that the combination of Abs to human SIRPα with therapeutic Abs specific for tumor antigens warrants further investigation for potential application to cancer immunotherapy. In addition, humanized mice, such as hSIRPα-DKO mice, should prove useful for validation of the antitumor effects of checkpoint inhibitors before testing in clinical trials. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  1. Anti-S100A4 antibody suppresses metastasis formation by blocking stroma cell invasion

    DEFF Research Database (Denmark)

    Klingelhöfer, Jörg; Grum-Schwensen, Birgitte; Beck, Mette K

    2012-01-01

    microenvironment, making it an attractive target for anti-cancer therapy. In this study, we produced a function-blocking anti-S100A4 monoclonal antibody with metastasis-suppressing activity. Antibody treatment significantly reduced metastatic burden in the lungs of experimental animals by blocking the recruitment...... of T cells to the site of the primary tumor. In vitro studies demonstrated that this antibody efficiently reduced the invasion of T cells in a fibroblast monolayer. Moreover, it was capable of suppressing the invasive growth of human and mouse fibroblasts. We presume therefore that the antibody exerts...... its activity by suppressing stroma cell recruitment to the site of the growing tumor. Our epitope mapping studies suggested that the antibody recognition site overlaps with the target binding interface of human S100A4. We conclude here that this antibody could serve as a solid basis for development...

  2. The importance of Foxp3 antibody and fixation/permeabilization buffer combinations in identifying CD4+CD25+Foxp3+ regulatory T cells.

    Science.gov (United States)

    Law, Jacqueline P; Hirschkorn, Dale F; Owen, Rachel E; Biswas, Hope H; Norris, Philip J; Lanteri, Marion C

    2009-12-01

    Foxp3 is a key marker for CD4(+) regulatory T cells (T(regs)) and was used in developing a multiparameter flow cytometric panel to identify T(regs). Achieving reproducible staining and analysis first required optimization of Foxp3 staining. We present a comparative study of PCH101, 236A/E7, 3G3, 206D, 150D, and 259D/C7 clones of anti-human-Foxp3 antibodies used in combination with five different fixation/permeabilization buffers. Staining for CD25, CD152, and CD127 was also compared between fixation/permeabilization treatments. Promising antibody/buffer combinations were tested in a panel of peripheral blood mononuclear cells from 10 individuals, and then on fresh versus frozen cells from four individuals. Finally, different fluorochromes coupled to two representative antibodies were compared to optimize separation of Foxp3(+) from Foxp3(-) events. Foxp3 gates were set using two gating strategies based on CD127(+)CD25(-) "non-T(regs)" or based on isotype controls. For Foxp3 staining, the best conditions for fixation/permeabilization were obtained using the eBioscience Foxp3, Imgenex, BioLegend, and BD Foxp3 buffers. Comparing results from 10 subjects, 259D/C7, PCH101, 236A/E7, and 206D antibodies yielded statistically higher levels of Foxp3 cells than those by 150D and 3G3 antibodies (mean = 6.9, 5.1, 4.7, and 3.7% compared with 1.7, and 0.3% of CD25(+)Foxp3(+) events within CD4(+) cells, respectively). Importantly, the "nonspecificity" of some antibodies observed with a Foxp3 gate based on isotype controls could be eliminated by setting the Foxp3 gate on "non-T(regs)". Better separation of Foxp3(+) and Foxp3(-) populations was observed using the PCH101 clone coupled to Alexa647 compared with FITC or the 259D/C7 clone coupled to PE compared with Alexa488 fluorochrome. Foxp3 staining can be highly variable and depends on the choice of antibody/buffer pair and the fluorochrome used. Selecting the correct population for setting the Foxp3 gate is critical to avoid

  3. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Donor-Specific Anti-HLA Antibodies in Huntington's Disease Recipients of Human Fetal Striatal Grafts.

    Science.gov (United States)

    Porfirio, Berardino; Paganini, Marco; Mazzanti, Benedetta; Bagnoli, Silvia; Bucciantini, Sandra; Ghelli, Elena; Nacmias, Benedetta; Putignano, Anna Laura; Rombolà, Giovanni; Saccardi, Riccardo; Lombardini, Letizia; Di Lorenzo, Nicola; Vannelli, Gabriella B; Gallina, Pasquale

    2015-01-01

    Fetal grafting in a human diseased brain was thought to be less immunogenic than other solid organ transplants, hence the minor impact on the efficacy of the transplant. How much prophylactic immune protection is required for neural allotransplantation is also debated. High-sensitive anti-HLA antibody screening in this field has never been reported. Sixteen patients with Huntington's disease underwent human fetal striatal transplantation in the frame of an open-label observational trial, which is being carried out at Florence University. All patients had both brain hemispheres grafted in two separate robotic-stereotactic procedures. The trial started in February 2006 with the first graft to the first patient (R1). R16 was given his second graft on March 2011. All patients received triple immunosuppressive treatment. Pre- and posttransplant sera were analyzed for the presence of anti-HLA antibodies using the multiplexed microsphere-based suspension array Luminex xMAP technology. Median follow-up was 38.5 months (range 13-85). Six patients developed anti-HLA antibodies, which turned out to be donor specific. Alloimmunization occurred in a time window of 0-49 months after the first neurosurgical procedure. The immunogenic determinants were non-self-epitopes from mismatched HLA antigens. These determinants were both public epitopes shared by two or more HLA molecules and private epitopes unique to individual HLA molecules. One patient had non-donor-specific anti-HLA antibodies in her pretransplant serum sample, possibly due to previous sensitization events. Although the clinical significance of donor-specific antibodies is far from being established, particularly in the setting of neuronal transplantation, these findings underline the need of careful pre- and posttransplant immunogenetic evaluation of patients with intracerebral grafts.

  5. Antibody response is required for protection from Theiler's virus-induced encephalitis in C57BL/6 mice in the absence of CD8+ T cells

    International Nuclear Information System (INIS)

    Kang, B.-S.; Palma, Joann P.; Lyman, Michael A.; Dal Canto, Mauro; Kim, Byung S.

    2005-01-01

    Intracerebral infection of susceptible mice with Theiler's murine encephalomyelitis virus (TMEV) induces immune-mediated demyelinating disease and this system serves as a relevant infectious model for human multiple sclerosis. It was previously shown that β 2 M-deficient C57BL/6 mice lacking functional CD8 + T cells display increased viral persistence and enhanced susceptibility to TMEV-induced demyelination, and yet the majority of mice are free of clinical signs. To understand the mechanisms involved in this general resistance of C57BL/6 mice in the absence of CTL responses, mice (μMT) deficient in the B-cell compartment lacking membrane IgM molecules were treated with anti-CD8 antibody and then infected with TMEV. Although little difference in the proliferative responses of peripheral T cells to UV-inactivated TMEV and the resistance to demyelinating disease was observed between virus-infected μMT and control B6 mice, the levels of CD4 + T cells were higher in the CNS of μMT mice. However, after treatment with anti-CD8 antibody, 100% of the mice displayed clinical gray matter disease and prolonged viral persistence in μMT mice, while only 10% of B6 mice showed clinical symptoms and very low viral persistence. Transfusion of sera from TMEV-infected B6 mice into anti-CD8 antibody-treated μMT mice partially restored resistance to virus-induced encephalitis. These results indicate that the early anti-viral antibody response is also important in the protection from TMEV-induced encephalitis particularly in the absence of CD8 + T cells

  6. 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

    were purified by protein G affinity chromatography from culture supernatant containing 10% (v/v) fetal calf serum (FCS). Human anti-animal IgG (bovine, mouse, horse, and swine) antibodies and human anti-bovine serum albumin antibodies were measured using an ELISA design, with direct bridging...... of the solid phase and biotinylated antigens. The false positive reactions were abolished by addition of 1% (v/v) bovine serum to the dilution buffer (DB). Human anti-bovine IgG antibodies (HABIA) were detected in 99 out of 104 sera from blood donors (50 females; 54 males). HABIA levels in male sera (n = 54......) were positively correlated to the false positive signals in the PP14 ELISA (r = 0.923; p detected in the donor sera, but levels and frequencies were lower compared to that of HABIA. Furthermore, HABIA were...

  7. Long-term anti-HBs antibody persistence following infant vaccination against hepatitis B and evaluation of anamnestic response: a 20-year follow-up study in Thailand.

    Science.gov (United States)

    Poovorawan, Yong; Chongsrisawat, Voranush; Theamboonlers, Apiradee; Crasta, Priya Diana; Messier, Marc; Hardt, Karin

    2013-08-01

    Hepatitis B vaccine has been available worldwide since the mid-1980s. This vaccine was evaluated in a clinical trial in Thailand, conducted on subjects born to hepatitis B surface antigen positive and hepatitis B e-antigen positive mothers and vaccinated according to a 4-dose schedule at 0, 1, 2 and 12 mo of age and a single dose of hepatitis B immunoglobulin concomitantly at birth. All enrolled subjects seroconverted and were followed for 20 y to assess the persistence of antibody to the hepatitis B surface antigen (anti-HBs) (NCT00240539). At year 20, 64% of subjects had anti-HBs antibody concentrations≥10 milli-international units per milli liter (mIU/ml) and 92% of subjects had detectable levels (≥3.3 mIU/ml) of anti-HBs antibodies. At year 20, subjects with anti-HBs antibody titermemory (NCT00657657). Anamnestic response to the challenge dose was observed in 96.6% of subjects with an 82-fold (13.2 to 1082.4 mIU/ml) increase in anti-HBs antibody geometric mean concentrations. This study confirms the long-term immunogenicity of the 4-dose regimen of the HBV vaccine eliciting long-term persistence of antibodies and immune memory against hepatitis B for up to at least 20 y after vaccination.

  8. Quantitation of anti-tetanus and anti-diphtheria antibodies by enzymoimmunoassay: methodology and applications.

    Science.gov (United States)

    Virella, G; Hyman, B

    1991-01-01

    We have developed enzymoimmunoassays (EIA) for the quantitation of antibodies (Ab) to tetanus and diphtheria toxoids (TT, DT) using Immulon I plates coated with the appropriate toxoid. A preparation of human tetanus immunoglobulin with a known concentration of anti-TT Ab was used as calibrator of the anti-TT antibody assay. The assay of anti-DT Ab is calibrated with a pool of human sera whose anti-DT Ab concentration was determined by quantitative immunoelectrophoresis, using a horse anti-DT with known Ab concentration as calibrator. A peroxidase-conjugated anti-human IgG was used in both assays. ABTS was used as substrate, and the reaction was stopped after 1 min incubation with citric acid and the OD measured at 414 nm on a Vmax reader. The assays have been applied to a variety of clinical situations. In patients suspected of having tetanus, the quantitation of antibodies has been helpful in establishing a diagnosis. In patients with a history of hypersensitivity to tetanus toxoid, verification of the levels of anti-TT antibody may prevent unnecessary and potentially harmful immunizations. The assays have also been used for the diagnostic evaluation of the humoral immune response to TT and DT, both in pediatric patients and in immunosuppressed patients. Several non-responders have been detected, and we have recently used the assay to monitor the effects of fish oil administration on the humoral immune response.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Panel reactive HLA antibodies, soluble CD30 levels, and acute rejection six months following renal transplant.

    Science.gov (United States)

    Domingues, Elizabeth M F L; Matuck, Teresa; Graciano, Miguel L; Souza, Edison; Rioja, Suzimar; Falci, Mônica C; Monteiro de Carvalho, Deise B; Porto, Luís Cristóvão

    2010-01-01

    Specific anti-human leukocyte antigen antibodies (HLA) in the post-transplant period may be present with acute rejection episodes (ARE), and high soluble CD30 (sCD30) serum levels may be a risk factor for ARE and graft loss. HLA cross-matching, panel reactive antibodies (PRA), and sCD30 levels were determined prior to transplantation in 72 patients. Soluble CD30 levels and PRA were re-assessed at day 7, 14, 21, and 28, and monthly up to the sixth.   Twenty-four subjects had a positive PRA and 17 experienced ARE. Nine of 17 ARE subjects demonstrated positive PRA and 16 had HLA mismatches. Positive PRA was more frequent in ARE subjects (p = 0.03). Eight subjects with ARE had donor-specific antibodies (DSA) in serum samples pre-transplantation, two subjects developed DSA. Three subjects without ARE had positive PRA only in post-transplantation samples. Soluble CD30 levels were higher in pre-transplant samples and ARE subjects than non-ARE subjects (p = 0.03). Post-transplant sCD30 levels were elevated in subjects who experienced rejection and were significantly higher at seven d (p = 0.0004) and six months (p = 0.03). Higher sCD30 levels following transplant were associated with ARE. Elevated sCD30 levels may represent a risk factor for acute rejection. © 2009 John Wiley & Sons A/S.

  10. Correlation of pharmacodynamic activity, pharmacokinetics, and anti-product antibody responses to anti-IL-21R antibody therapeutics following IV administration to cynomolgus monkeys

    Directory of Open Access Journals (Sweden)

    Spaulding Vikki

    2010-04-01

    Full Text Available Abstract Background Anti-IL-21R antibodies are potential therapeutics for the treatment of autoimmune diseases. This study evaluated correlations between the pharmacodynamic (PD activity, pharmacokinetics, and anti-product antibody responses of human anti-IL-21R antibodies Ab-01 and Ab-02 following IV administration to cynomolgus monkeys. Methods The PD assay was based on the ability of recombinant human IL-21 (rhuIL-21 to induce expression of the IL-2RA gene in cynomolgus monkey whole blood samples ex vivo. Monkeys screened for responsiveness to rhuIL-21 stimulation using the PD assay, were given a single 10 mg/kg IV dosage of Ab-01, Ab-02, or a control antibody (3/group, and blood samples were evaluated for PD activity (inhibition of IL-2RA expression for up to 148 days. Anti-IL-21R antibody concentrations and anti-product antibody responses were measured in serum using immunoassays and flow cytometry. Results Following IV administration of Ab-01 and Ab-02 to cynomolgus monkeys, PD activity was observed as early as 5 minutes (first time point sampled. This PD activity had good correlation with the serum concentrations and anti-product antibody responses throughout the study. The mean terminal half-life (t1/2 was ~10.6 and 2.3 days for Ab-01 and Ab-02, respectively. PD activity was lost at ~5-13 weeks for Ab-01 and at ~2 weeks for Ab-02, when serum concentrations were relatively low. The estimated minimum concentrations needed to maintain PD activity were ~4-6 nM for Ab-01 and ~2.5 nM for Ab-02, and were consistent with the respective KD values for binding to human IL-21R. For Ab-01, there was noticeable inter-animal variability in t1/2 values (~6-14 days and the resulting PD profiles, which correlated with the onset of anti-product antibody formation. While all three Ab-01-dosed animals were positive for anti-Ab-01 antibodies, only one monkey (with the shortest t1/2 and the earliest loss of PD activity had evidence of neutralizing anti-Ab-01

  11. Generation and testing anti-influenza human monoclonal antibodies in a new humanized mouse model (DRAGA: HLA-A2. HLA-DR4. Rag1 KO. IL-2Rγc KO. NOD).

    Science.gov (United States)

    Mendoza, Mirian; Ballesteros, Angela; Qiu, Qi; Pow Sang, Luis; Shashikumar, Soumya; Casares, Sofia; Brumeanu, Teodor-D

    2018-02-01

    Pandemic outbreaks of influenza type A viruses have resulted in numerous fatalities around the globe. Since the conventional influenza vaccines (CIV) provide less than 20% protection for individuals with weak immune system, it has been considered that broadly cross-neutralizing antibodies may provide a better protection. Herein, we showed that a recently generated humanized mouse (DRAGA mouse; HLA-A2. HLA-DR4. Rag1KO. IL-2Rgc KO. NOD) that lacks the murine immune system and expresses a functional human immune system can be used to generate cross-reactive, human anti-influenza monoclonal antibodies (hu-mAb). DRAGA mouse was also found to be suitable for influenza virus infection, as it can clear a sub-lethal infection and sustain a lethal infection with PR8/A/34 influenza virus. The hu-mAbs were designed for targeting a human B-cell epitope ( 180 WGIHHPPNSKEQ QNLY 195 ) of hemagglutinin (HA) envelope protein of PR8/A/34 (H1N1) virus with high homology among seven influenza type A viruses. A single administration of HA 180-195 specific hu-mAb in PR8-infected DRAGA mice significantly delayed the lethality by reducing the lung damage. The results demonstrated that DRAGA mouse is a suitable tool to (i) generate heterotype cross-reactive, anti-influenza human monoclonal antibodies, (ii) serve as a humanized mouse model for influenza infection, and (iii) assess the efficacy of anti-influenza antibody-based therapeutics for human use.

  12. Antibody Therapy Targeting CD47 and CD271 Effectively Suppresses Melanoma Metastasis in Patient-Derived Xenografts

    Directory of Open Access Journals (Sweden)

    Michael Ngo

    2016-08-01

    Full Text Available The high rate of metastasis and recurrence among melanoma patients indicates the existence of cells within melanoma that have the ability to both initiate metastatic programs and bypass immune recognition. Here, we identify CD47 as a regulator of melanoma tumor metastasis and immune evasion. Protein and gene expression analysis of clinical melanoma samples reveals that CD47, an anti-phagocytic signal, correlates with melanoma metastasis. Antibody-mediated blockade of CD47 coupled with targeting of CD271+ melanoma cells strongly inhibits tumor metastasis in patient-derived xenografts. This therapeutic effect is mediated by drastic changes in the tumor and metastatic site immune microenvironments, both of whichwhich exhibit greatly increased density of differentiated macrophages and significantly fewer inflammatory monocytes, pro-metastatic macrophages (CCR2+/VEGFR1+, and neutrophils, all of which are associated with disease progression. Thus, antibody therapy that activates the innate immune response in combination with selective targeting of CD271+ melanoma cells represents a powerful therapeutic approach against metastatic melanoma.

  13. Synthesis and characterization of C@CdS dots in aqueous solution and their application in labeling human gastric carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Wei, E-mail: dongwei5873@126.com [Shenyang Medical College, Department of Chemistry (China); Zhou, Siqi [Fengtian Hospital Affiliated to Shenyang Medical College, ICU (China); Dong, Yan [Shenyang Pharmaceutical University, Experiment Center of Traditional Chinese Medicine Department (China); Wang, Jingwen; Liu, Shuang; Zhu, Pengxia [Shenyang Medical College, Department of Chemistry (China)

    2015-03-15

    Colloidal carbon spheres coated with cadmium sulfide nanoparticle quantum dots (C@CdS dots) with the particle size smaller than 50 nm were synthesized by an aqueous approach. The effects of different reaction times, temperatures, and pH values were carefully investigated to optimize the synthesis conditions. The as-prepared C@CdS dots were linked with mouse anti-human carcinoembryonic antigen antibody and goat anti-mouse immunoglobulin (IgG) to directly and indirectly label fixed human gastric carcinoma cells, respectively. The cytotoxicity of the C@CdS dots was also tested using the human gastric carcinoma cells. No apparent cytotoxicity was observed, which suggested the potential application of the as-prepared C@CdS dots in bioimaging.

  14. Identification of anti-HPA-1a allo-antibodies using IgG platelet antibody detection and crossmatch system assay with Galileo Echo.

    Science.gov (United States)

    Di Cristofaro, Julie; Frassati, Coralie; Montagnie, Rolande; Basire, Agnes; Merieux, Yves; Picard, Christophe

    2015-01-01

    Fetal/neonatal allo-immune thrombocytopenia is the most frequent and the most dangerous clinical condition involving anti-human platelet antigens (HPA)-1a allo-antibodies. Anti-HPA-1a allo-immunization requires rapid and accurate diagnosis to determine appropriate treatment. The Capture-P Ready-Screen assay (C-PRS) is a new qualitative immunoassay to detect IgG anti-human leukocyte antigen (HLA) and anti-HPA allo-antibodies. The aim of this study is to assess the identification of anti-HPA-1a allo-antibodies using the C-PRS assay, associated with HLA class I stripping reagents, on the automated benchtop analyzer Galileo Echo. Forty-nine sera were analyzed: without anti-HLA class I or anti-HPA allo-antibodies, with anti-HLA class I allo-antibodies, with anti-HPA-1a allo-antibodies, among which with anti-HLA class I allo-antibodies. None of the samples without allo-antibodies were reactive. Only anti-HLA antibodies, detected by cytotoxicity-dependent complement and not by Luminex, remained positive before and after stripping reagents. Of the 13 samples, anti-HPA-1a allo-antibodies that were correctly identified before and after incubation with HLA assassin reagent were 70% and 85%, respectively. Anti-glycoprotein auto-antibodies and anti-HLA allo-antibodies do not interfere with the detection of anti-HPA-1a antibodies. This preliminary study indicates that further improvement of the test will be helpful in developing a clinically useful assay in the future.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  16. Anti-idiotypic antibodies to poliovirus antibodies in commercial immunoglubulin preparations, human serum and milk.

    NARCIS (Netherlands)

    M. Hahn-Zoric; B. Carlsson; S. Jeansson; H.P. Ekre; A.D.M.E. Osterhaus (Albert); D. Roberton; L.A. Hanson

    1993-01-01

    textabstractOur previous studies have suggested that fetal antibody production can be induced by maternal antiidiotypic antibodies transferred to the fetus via the placenta. We tested commercial Ig, sera, and milk for the presence of anti-idiotypic antibodies to poliovirus type 1, using affinity

  17. Antibody-dependent cellular cytotoxicity (ADCC) activity of a novel anti-PD-L1 antibody avelumab (MSB0010718C) on human tumor cells

    OpenAIRE

    Boyerinas, Benjamin; Jochems, Caroline; Fantini, Massimo; Heery, Christopher R.; Gulley, James L.; Tsang, Kwong Yok; Schlom, Jeffrey

    2015-01-01

    Several anti-PD1/PD-L1 monoclonal antibodies (MAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these MAbs is to inhibit PD1 on immune cells interacting with PD-L1 on tumor cells. These MAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective MAb-mediated cancer therapies. A fully human anti-PD-L...

  18. Serological analysis of human IgG and IgE anti-insulin antibodies by solid-phase radioimmunoassays

    International Nuclear Information System (INIS)

    Hamilton, R.G.; Rendell, M.; Adkinson, N.F. Jr.

    1980-01-01

    A single solid-phase assay system which is useful for quantitative measurement of both IgG and IgE anti-insulin antibodies in human serum has been developed. Insulin-specific immunoglobulins are absorbed from human serum by excess quantities of insulin-agarose. After washes to remove unbound immunoglobulins, radioiodinated Staph A or rabbit anti-human IgE is added to detect bound IgG or IgE anbitodies, respectively

  19. Enhancement of retroviral infection in vitro by anti-Le(y) IgG: reversal by humanization of monoclonal mouse antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Sørensen, A M; Arendrup, M

    1993-01-01

    Monoclonal mouse IgG3 antibody (ABL 364) against the carbohydrate Le(y) antigen enhanced infection in vitro with HTLV-1 and with HIV-1 when propagated in both transformed and normal lymphocytes. Enhancement was independent of complement, occurred with both lymphocytes and monocytes as target cells...... with no indication of any alternative pathway of infection, as evidenced by abrogation of enhancement by anti-CD4 MAb or soluble recombinant CD4, and also the inability of anti-Le(y) MAb to mediate HIV infection of HSB-2 cells in which HTLV-1/HIV pseudovirus infection was enhanced. While F(ab)2 fragments of ABL 364...

  20. Immunization of chickens with an agonistic monoclonal anti-chicken CD40 antibody-hapten complex: rapid and robust IgG response induced by a single subcutaneous injection.

    Science.gov (United States)

    Chen, Chang-Hsin; Abi-Ghanem, Daad; Waghela, Suryakant D; Chou, Wen-Ko; Farnell, Morgan B; Mwangi, Waithaka; Berghman, Luc R

    2012-04-30

    Producing diagnostic antibodies in chicken egg yolk represents an alternate animal system that offers many advantages including high productivity at low cost. Despite being an excellent counterpart to mammalian antibodies, chicken IgG from yolk still represents an underused resource. The potential of agonistic monoclonal anti-CD40 antibodies (mAb) as a powerful immunological adjuvant has been demonstrated in mammals, but not in chickens. We recently reported an agonistic anti-chicken CD40 mAb (designated mAb 2C5) and showed that it may have potential as an immunological adjuvant. In this study, we examined the efficacy of targeting a short peptide to chicken CD40 [expressed by the antigen-presenting cells (APCs)] in enhancing an effective IgG response in chickens. For this purpose, an immune complex consisting of one streptavidin molecule, two directionally biotinylated mAb 2C5 molecules, and two biotinylated peptide molecules was produced. Chickens were immunized subcutaneously with doses of this complex ranging from 10 to 90 μg per injection once, and relative quantification of the peptide-specific IgG response showed that the mAb 2C5-based complex was able to elicit a strong IgG response as early as four days post-immunization. This demonstrates that CD40-targeting antigen to chicken APCs can significantly enhance antibody responses and induce immunoglobulin isotype-switching. This immunization strategy holds promise for rapid production of hapten-specific IgG in chickens. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Human anti-CAIX antibodies mediate immune cell inhibition of renal cell carcinoma in vitro and in a humanized mouse model in vivo.

    Science.gov (United States)

    Chang, De-Kuan; Moniz, Raymond J; Xu, Zhongyao; Sun, Jiusong; Signoretti, Sabina; Zhu, Quan; Marasco, Wayne A

    2015-06-11

    Carbonic anhydrase (CA) IX is a surface-expressed protein that is upregulated by the hypoxia inducible factor (HIF) and represents a prototypic tumor-associated antigen that is overexpressed on renal cell carcinoma (RCC). Therapeutic approaches targeting CAIX have focused on the development of CAIX inhibitors and specific immunotherapies including monoclonal antibodies (mAbs). However, current in vivo mouse models used to characterize the anti-tumor properties of fully human anti-CAIX mAbs have significant limitations since the role of human effector cells in tumor cell killing in vivo is not directly evaluated. The role of human anti-CAIX mAbs on CAIX(+) RCC tumor cell killing by immunocytes or complement was tested in vitro by antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC) and antibody-dependent cellular phagocytosis (ADCP) as well as on CAIX(+) RCC cellular motility, wound healing, migration and proliferation. The in vivo therapeutic activity mediated by anti-CAIX mAbs was determined by using a novel orthotopic RCC xenograft humanized animal model and analyzed by histology and FACS staining. Our studies demonstrate the capacity of human anti-CAIX mAbs that inhibit CA enzymatic activity to result in immune-mediated killing of RCC, including nature killer (NK) cell-mediated ADCC, CDC, and macrophage-mediated ADCP. The killing activity correlated positively with the level of CAIX expression on RCC tumor cell lines. In addition, Fc engineering of anti-CAIX mAbs was shown to enhance the ADCC activity against RCC. We also demonstrate that these anti-CAIX mAbs inhibit migration of RCC cells in vitro. Finally, through the implementation of a novel orthotopic RCC model utilizing allogeneic human peripheral blood mononuclear cells in NOD/SCID/IL2Rγ(-/-) mice, we show that anti-CAIX mAbs are capable of mediating human immune response in vivo including tumor infiltration of NK cells and activation of T cells, resulting in

  2. Characterization of CD4 T Cell Epitopes of Infliximab and Rituximab Identified from Healthy Donors

    Directory of Open Access Journals (Sweden)

    Moustafa Hamze

    2017-05-01

    Full Text Available The chimeric antibodies anti-CD20 rituximab (Rtx and anti-TNFα infliximab (Ifx induce antidrug antibodies (ADAs in many patients with inflammatory diseases. Because of the key role of CD4 T lymphocytes in the initiation of antibody responses, we localized the CD4 T cell epitopes of Rtx and Ifx. With the perspective to anticipate immunogenicity of therapeutic antibodies, identification of the CD4 T cell epitopes was performed using cells collected in healthy donors. Nine T cell epitopes were identified in the variable chains of both antibodies by deriving CD4 T cell lines raised against either Rtx or Ifx. The T cell epitopes often exhibited a good affinity for human leukocyte antigen (HLA-DR molecules and were part of the peptides identified by MHC-associated peptide proteomics assay from HLA-DR molecules of dendritic cells (DCs loaded with the antibodies. Two-third of the T cell epitopes identified from the healthy donors stimulated peripheral blood mononuclear cells from patients having developed ADAs against Rtx or Ifx and promoted the secretion of a diversity of cytokines. These data emphasize the predictive value of evaluating the T cell repertoire of healthy donors and the composition of peptides bound to HLA-DR of DCs to anticipate and prevent immunogenicity of therapeutic antibodies.

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

    Directory of Open Access Journals (Sweden)

    Xiaocong Yu

    2016-01-01

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

  4. Characterization of SGN-CD123A, A Potent CD123-Directed Antibody-Drug Conjugate for Acute Myeloid Leukemia.

    Science.gov (United States)

    Li, Fu; Sutherland, May Kung; Yu, Changpu; Walter, Roland B; Westendorf, Lori; Valliere-Douglass, John; Pan, Lucy; Cronkite, Ashley; Sussman, Django; Klussman, Kerry; Ulrich, Michelle; Anderson, Martha E; Stone, Ivan J; Zeng, Weiping; Jonas, Mechthild; Lewis, Timothy S; Goswami, Maitrayee; Wang, Sa A; Senter, Peter D; Law, Che-Leung; Feldman, Eric J; Benjamin, Dennis R

    2018-02-01

    Treatment choices for acute myelogenous leukemia (AML) patients resistant to conventional chemotherapies are limited and novel therapeutic agents are needed. IL3 receptor alpha (IL3Rα, or CD123) is expressed on the majority of AML blasts, and there is evidence that its expression is increased on leukemic relative to normal hematopoietic stem cells, which makes it an attractive target for antibody-based therapy. Here, we report the generation and preclinical characterization of SGN-CD123A, an antibody-drug conjugate using the pyrrolobenzodiazepine dimer (PBD) linker and a humanized CD123 antibody with engineered cysteines for site-specific conjugation. Mechanistically, SGN-CD123A induces activation of DNA damage response pathways, cell-cycle changes, and apoptosis in AML cells. In vitro , SGN-CD123A-mediated potent cytotoxicity of 11/12 CD123 + AML cell lines and 20/23 primary samples from AML patients, including those with unfavorable cytogenetic profiles or FLT3 mutations. In vivo , SGN-CD123A treatment led to AML eradication in a disseminated disease model, remission in a subcutaneous xenograft model, and significant growth delay in a multidrug resistance xenograft model. Moreover, SGN-CD123A also resulted in durable complete remission of a patient-derived xenograft AML model. When combined with a FLT3 inhibitor quizartinib, SGN-CD123A enhanced the activity of quizartinib against two FLT3-mutated xenograft models. Overall, these data demonstrate that SGN-CD123A is a potent antileukemic agent, supporting an ongoing trial to evaluate its safety and efficacy in AML patients (NCT02848248). Mol Cancer Ther; 17(2); 554-64. ©2017 AACR . ©2017 American Association for Cancer Research.

  5. An indirect antibody assay using haptenated antigen and 125I-labelled anti-hapten antibody

    International Nuclear Information System (INIS)

    Aalberse, R.C.; Amsterdam Univ.

    1978-01-01

    Hapten (trinitrophenyl) was coupled to antigen (ovalbumin). The haptenated antigen was bound by anti-ovalbumin antibody and binding was quantitated with 125 I-labelled anti-hapten antibodies. Thus, with a single radioactive reagent, antibodies against a variety of antigens can be detected while the problems inherent in a labelled antiglobulin binding test are avoided. In the ovalbumin system, the haptenated antigen binding test proved to be approximately 20 times as sensitive as the iodinated ovalbumin binding test

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

    Science.gov (United States)

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

    2011-01-01

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

  7. Anti-carbamylated Protein Antibody Levels Correlate with Anti-Sa (Citrullinated Vimentin) Antibody Levels in Rheumatoid Arthritis.

    Science.gov (United States)

    Challener, Gregory J; Jones, Jonathan D; Pelzek, Adam J; Hamilton, B JoNell; Boire, Gilles; de Brum-Fernandes, Artur José; Masetto, Ariel; Carrier, Nathalie; Ménard, Henri A; Silverman, Gregg J; Rigby, William F C

    2016-02-01

    The presence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) indicates a breach in immune tolerance. Recent studies indicate that this breach extends to homocitrullination of lysines with the formation of anti-carbamylated protein (anti-CarP) antibodies. We analyzed the clinical and serologic relationships of anti-CarP in 2 RA cohorts. Circulating levels of immunoglobulin G anti-CarP antibodies were determined by ELISA in established (Dartmouth-Hitchcock Medical Center) and early (Sherbrooke University Hospital Center) cohorts and evaluated for anticyclic citrullinated peptide antibodies (anti-CCP), specific ACPA, and rheumatoid factor (RF) levels using the Student t test and correlation analysis. We identified elevated anti-CarP antibodies titers in 47.0% of seropositive patients (Dartmouth, n = 164), with relationships to anti-CCP (p < 0.0001) and IgM-RF (p = 0.001). Similarly, 38.2% of seropositive patients from the Sherbrooke cohort (n = 171) had elevated anti-CarP antibodies; titers correlated to anti-CCP (p = 0.01) but not IgM-RF (p = 0.09). A strong correlation with anti-Sa was observed: 47.9% anti-Sa+ patients were anti-CarP antibodies+ versus only 25.4% anti-Sa- in the Sherbrooke cohort (p = 0.0002), and 62.6% anti-Sa+ patients versus 26.9% anti-Sa- were anti-CarP antibodies+ in Dartmouth (p < 0.0001). We found a more variable response for reactivity to citrullinated fibrinogen or to citrullinated peptides from fibrinogen and α enolase. In 2 North American RA cohorts, we observed a high prevalence of anti-CarP antibody positivity. We also describe a surprising and unexpected association of anti-CarP with anti-Sa antibodies that could not be explained by cross-reactivity. Further, considerable heterogeneity exists between anti-CarP reactivity and other citrullinated peptide reactivity, raising the question of how the pathogenesis of antibody responses for carbamylated proteins and citrullinated proteins may be linked in vivo.

  8. Anti sperm antibodies detection in infertile patients by radioimmunometry

    International Nuclear Information System (INIS)

    ELnabarawy, F.; Megahed, Y.M.; Tadrous, G.A.; Hamada, T.; Elbadry, A.

    1992-01-01

    Three different methods of testing for anti sperm antibodies were compared: complement cytotoxicity, sperm agglutination, and radiolabelled anti globulin antibody technique, for detection of anti sperm antibodies in serum and secretions (seminal plasma and cervical mucus). Sample from 120 patients with infertility were investigated by the previous three methods. The results of unexplained infertile patients revealed wide variations in figures, concerning the positivity of anti sperm antibody whether in their serum or secretions, by using the cytotoxicity or sperm agglutination tests. Using a specific radiolabelled anti globulin test, a subset of patients (44.9% in the serum of men and 50% in seminal plasma) with IgG anti sperm antibody was identified, and this antibody was present in 65.4% and 78,6% of infertile wives sera and cervical mucus, respectively. Therefore, this test has been used to identify and quantitate antibodies directed toward other human cell surfaces. It was concluded that this radiolabelled method is a clinically useful and a potentially versatile procedure that can be successfully applied to the diagnosis and management of patients with suspected immunologic infertility. 1 fig., 5 tab

  9. Type I CD20 Antibodies Recruit the B Cell Receptor for Complement-Dependent Lysis of Malignant B Cells

    NARCIS (Netherlands)

    Engelberts, Patrick J.; Voorhorst, Marleen; Schuurman, Janine; van Meerten, Tom; Bakker, Joost M.; Vink, Tom; Mackus, Wendy J. M.; Breij, Esther C. W.; Derer, Stefanie; Valerius, Thomas; van de Winkel, Jan G. J.; Parren, Paul W. H. I.; Beurskens, Frank J.

    2016-01-01

    Human IgG1 type I CD20 Abs, such as rituximab and ofatumumab (OFA), efficiently induce complement-dependent cytotoxicity (CDC) of CD20(+) B cells by binding of C1 to hexamerized Fc domains. Unexpectedly, we found that type I CD20 Ab F(ab ')2 fragments, as well as C1q-binding-deficient IgG mutants,

  10. T CD3+CD8+ Lymphocytes Are More Susceptible for Apoptosis in the First Trimester of Normal Human Pregnancy

    Directory of Open Access Journals (Sweden)

    Dorota Darmochwal-Kolarz

    2014-01-01

    Full Text Available Aims. Normal human pregnancy is a complex process of many immunoregulatory mechanisms which protect fetus from the activation of the maternal immune system. The aim of the study was to investigate the apoptosis of lymphocytes in peripheral blood of normal pregnant patients and healthy nonpregnant women. Methods. Sixty pregnant women and 17 nonpregnant women were included in the study. Lymphocytes were isolated and labeled with anti-CD3, anti-CD4, and anti-CD8 monoclonal antibodies. Apoptosis was detected by CMXRos staining and analyzed using the flow cytometric method. Results. We found significantly higher apoptosis of total lymphocytes in peripheral blood of pregnant patients when compared to healthy nonpregnant women. The percentage of apoptotic T CD3+CD8+ cells in the first trimester was significantly higher when compared to the third trimester of normal pregnancy. The ratio of T CD3+CD4+ : T CD3+CD8+ apoptotic lymphocytes was significantly lower in the first trimester when compared to other trimesters of pregnancy and to both of the phases of the menstrual cycle. Conclusions. The higher apoptosis of T CD3+CD8+ lymphocytes and the lower ratio of T CD3+CD4+ : T CD3+CD8+ apoptotic cells in the first trimester of normal pregnancy may suggest a higher susceptibility of T CD3+CD8+ cells for apoptosis as a protective mechanism at the early stage of pregnancy.

  11. Immunoscintigraphy of human tumors transplanted in nude mice with radiolabeled anti-ras p21 monoclonal antibodies

    International Nuclear Information System (INIS)

    Katoh, Y.; Nakata, K.; Kohno, K.; Shima, M.; Satoh, A.; Kusumoto, Y.; Ishii, N.; Kohji, T.; Shiku, H.; Nagataki, S.

    1990-01-01

    Anti-ras p21 monoclonal antibody (RASK-3) was used for immunoscintigraphy of human cancer cell lines in nude mice. Iodine-125-labeled RASK-3 was injected into nude mice with either human colon cancers (FCC-1 or BM-314) or lung cancer (KNS-62). Clear images were obtained in all three cancers 7 days after the injection of antibody. No localization of 125 I-labeled control monoclonal antibody was observed. The ratio of tissue/blood radioactivity and % ID/g in the tumor were significantly higher than other organs by Day 8. The specific localization index examined by 131 I-RASK-3 and 125 I-control monoclonal antibody was also higher in the tumor than in other tissues. In the in vitro study, binding of RASK-3 to tumor cells increased significantly by treatment of cells with either lysolecithin or periodate-lysine-paraformaldehyde, which confirmed the intracellular localization of ras p21. The mechanism by which anti-ras p21 antibodies accumulate in tumor sites could be the necrotic changes in tumor cells or changes in membrane permeability of non-necrotic cells. These results provide a strong rationale for the utilization of ras p21 as a target antigen in the imaging of a variety of human cancers

  12. A novel strategy inducing autophagic cell death in Burkitt's lymphoma cells with anti-CD19-targeted liposomal rapamycin

    International Nuclear Information System (INIS)

    Ono, K; Sato, T; Iyama, S; Tatekoshi, A; Hashimoto, A; Kamihara, Y; Horiguchi, H; Kikuchi, S; Kawano, Y; Takada, K; Hayashi, T; Miyanishi, K; Sato, Y; Takimoto, R; Kobune, M; Kato, J

    2014-01-01

    Relapsed or refractory Burkitt's lymphoma often has a poor prognosis in spite of intensive chemotherapy that induces apoptotic and/or necrotic death of lymphoma cells. Rapamycin (Rap) brings about autophagy, and could be another treatment. Further, anti-CD19-targeted liposomal delivery may enable Rap to kill lymphoma cells specifically. Rap was encapsulated by anionic liposome and conjugated with anti-CD19 antibody (CD19-GL-Rap) or anti-CD2 antibody (CD2-GL-Rap) as a control. A fluorescent probe Cy5.5 was also liposomized in the same way (CD19 or CD2-GL-Cy5.5) to examine the efficacy of anti-CD19-targeted liposomal delivery into CD19-positive Burkitt's lymphoma cell line, SKW6.4. CD19-GL-Cy5.5 was more effectively uptaken into SKW6.4 cells than CD2-GL-Cy5.5 in vitro. When the cells were inoculated subcutaneously into nonobese diabetic/severe combined immunodeficiency mice, intravenously administered CD19-GL-Cy5.5 made the subcutaneous tumor fluorescent, while CD2-GL-Cy5.5 did not. Further, CD19-GL-Rap had a greater cytocidal effect on not only SKW6.4 cells but also Burkitt's lymphoma cells derived from patients than CD2-GL-Rap in vitro. The specific toxicity of CD19-GL-Rap was cancelled by neutralizing anti-CD19 antibody. The survival period of mice treated with intravenous CD19-GL-Rap was significantly longer than that of mice treated with CD2-GL-Rap after intraperitoneal inoculation of SKW6.4 cells. Anti-CD19-targeted liposomal Rap could be a promising lymphoma cell-specific treatment inducing autophagic cell death

  13. C4d-negative antibody-mediated rejection with high anti-angiotensin II type I receptor antibodies in absence of donor-specific antibodies.

    Science.gov (United States)

    Fuss, Alexander; Hope, Christopher M; Deayton, Susan; Bennett, Greg Donald; Holdsworth, Rhonda; Carroll, Robert P; Coates, P Toby H

    2015-07-01

    Acute antibody-mediated rejection can occur in absence of circulating donor-specific antibodies. Agonistic antibodies targeting the anti-angiotensin II type 1 receptor (anti-AT1 R) are emerging as important non-human leucocyte antigen (HLA) antibodies. Elevated levels of anti-angiotensin II receptor antibodies were first observed in kidney transplant recipients with malignant hypertension and allograft rejection. They have now been studied in three separate kidney transplant populations and associate to frequency of rejection, severity of rejection and graft failure. We report 11 cases of biopsy-proven, Complement 4 fragment d (C4d)-negative, acute rejection occurring without circulating donor-specific anti-HLA antibodies. In eight cases, anti-angiotensin receptor antibodies were retrospectively examined. The remaining three subjects were identified from our centre's newly instituted routine anti-angiotensin receptor antibody screening. All subjects fulfilled Banff 2013 criteria for antibody-mediated rejection and all responded to anti-rejection therapy, which included plasma exchange and angiotensin receptor blocker therapy. These cases support the routine assessment of anti-AT1 R antibodies in kidney transplant recipients to identify subjects at risk. Further studies will need to determine optimal assessment protocol and the effectiveness of pre-emptive treatment with angiotensin receptor blockers. © 2015 Asian Pacific Society of Nephrology.

  14. Regression of established renal cell carcinoma in nude mice using lentivirus-transduced human T cells expressing a human anti-CAIX chimeric antigen receptor

    Directory of Open Access Journals (Sweden)

    Agnes Shuk-Yee Lo

    2014-01-01

    Full Text Available Carbonic anhydrase IX (CAIX is a tumor-associated antigen and marker of hypoxia that is overexpressed on > 90% of clear-cell type renal cell carcinoma (RCC but not on neighboring normal kidney tissue. Here, we report on the construction of two chimeric antigen receptors (CARs that utilize a carbonic anhydrase (CA domain mapped, human single chain antibody (scFv G36 as a targeting moiety but differ in their capacity to provide costimulatory signaling for optimal T cell proliferation and tumor cell killing. The resulting anti-CAIX CARs were expressed on human primary T cells via lentivirus transduction. CAR-transduced T cells (CART cells expressing second-generation G36-CD28-TCRζ exhibited more potent in vitro antitumor effects on CAIX+ RCC cells than first-generation G36-CD8-TCRζ including cytotoxicity, cytokine secretion, proliferation, and clonal expansion. Adoptive G36-CD28-TCRζ CART cell therapy combined with high-dose interleukin (IL-2 injection also lead to superior regression of established RCC in nude mice with evidence of tumor cell apoptosis and tissue necrosis. These results suggest that the fully human G36-CD28-TCRζ CARs should provide substantial improvements over first-generation mouse anti-CAIX CARs in clinical use through reduced human anti-mouse antibody responses against the targeting scFv and administration of lower doses of T cells during CART cell therapy of CAIX+ RCC.

  15. Identification and Functional Characterization of Human Cd4+Cd25+ T Cells with Regulatory Properties Isolated from Peripheral Blood

    Science.gov (United States)

    Jonuleit, Helmut; Schmitt, Edgar; Stassen, Michael; Tuettenberg, Andrea; Knop, Jurgen; Enk, Alexander H.

    2001-01-01

    A subpopulation of peripheral human CD4+CD25+ T cells that expresses CD45RO, histocompatibility leukocyte antigen DR, and intracellular cytotoxic T lymphocyte–associated antigen (CTLA) 4 does not expand after stimulation and markedly suppresses the expansion of conventional T cells in a contact-dependent manner. After activation, CD4+CD25+ T cells express CTLA-4 on the surface detectable for several weeks. These cells show a G1/G0 cell cycle arrest and no production of interleukin (IL)-2, IL-4, or interferon (IFN)-γ on either protein or mRNA levels. The anergic state of CD4+CD25+ T cells is not reversible by the addition of anti-CD28, anti–CTLA-4, anti–transforming growth factor β, or anti–IL-10 antibody. However, the refractory state of CD4+CD25+ T cells was partially reversible by the addition of IL-2 or IL-4. These data demonstrate that human blood contains a resident T cell population with potent regulatory properties. PMID:11390435

  16. Frequency of anti thyroid peroxidase antibody in patients of vitiligo

    International Nuclear Information System (INIS)

    Zhokhar, A.; Shaikh, Z.I.

    2013-01-01

    Objective: The objective of this study was to compare the frequency of anti thyroid peroxidase antibody in patients suffering from vitiligo with healthy control group. Type of Study: Case control study. Settings: Dermatology Department, Military Hospital, Rawalpindi, from 20th March 2010 to 20th July 2011. Material and Methods: Fifty clinically diagnosed patients of vitiligo, age = 18 yrs and both genders with no history of thyroid disease, past or current use of drugs for thyroid disorder or thyroid surgery were included as cases (Group A). Fifty healthy individuals with no evidence of vitiligo or thyroid disorder on history and physical examination and with no family history of vitiligo, matched for age and gender with cases, were included as control (Group B). Serum anti thyroid peroxidase (anti TPO) antibodies were measured using enzyme linked immunosorbent assay (ELISA) in both cases and control. Results: Eight (16%) patients in Group A were anti-thyroid peroxidase antibody positive and forty two (84%) patients were negative while one (2%) patient was anti-thyroid peroxidase antibody positive in Group B and forty nine (98%) patients were negative (p = 0.001). Conclusion: Anti TPO antibody is significantly more common in patients of vitiligo as compared to general population. (author)

  17. 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.

  18. Induction of anti-tumor immunity by trifunctional antibodies in patients with peritoneal carcinomatosis

    Directory of Open Access Journals (Sweden)

    Lindhofer Horst

    2009-02-01

    Full Text Available Abstract Peritoneal carcinomatosis (PC from epithelial tumors is a fatal diagnosis without efficient treatment. Trifunctional antibodies (trAb are novel therapeutic approaches leading to a concerted anti-tumor activity resulting in tumor cell destruction. In addition, preclinical data in mouse tumor models demonstrated the induction of long lasting tumor immunity after treatment with trAb. We describe the induction of anti-tumor specific T-lymphocytes after intraperitoneal administration of trAb in patients with PC. 9 patients with progressive PC from gastric (n = 6 and ovarian cancer (n = 2, and cancer of unknown primary (n = 1 received 3 escalating doses of trAb after surgery and/or ineffective chemotherapy. The trAb EpCAM × CD3 (10, 20, 40 μg or HER2/neu × CD3 (10, 40, 80 μg were applicated by intraperitoneal infusion. Four weeks after the last trAb application, all patients were restimulated by subdermal injection of trAb + autologous PBMC + irradiated autologous tumor cells. Immunological reactivity was tested by analyzing PBMC for specific tumor reactive CD4+/CD8+ T lymphocytes using an IFN-γ secretion assay. In 5 of 9 patients, tumor reactive CD4+/CD8+ T-lymphocytes increased significantly, indicating specific anti-tumor immunity. A clinical response (stable disease, partial regression has been observed in 5 of 9 patients, with a mean time to progression of 3.6 months. Follow-up showed a mean survival of 11.8 months (median 8.0 months after trAb therapy. TrAb are able to induce anti-tumor immunity after intraperitoneal application and restimulation. The induction of long-lasting anti-tumor immunity may provide an additional benefit of the intraperitoneal therapy with trAb and should be further elevated in larger clinical trials.

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

    Directory of Open Access Journals (Sweden)

    Xiaodong Xiao

    2010-10-01

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

  20. Properties of human blood monocytes. I. CD91 expression and log orthogonal light scatter provide a robust method to identify monocytes that is more accurate than CD14 expression.

    Science.gov (United States)

    Hudig, Dorothy; Hunter, Kenneth W; Diamond, W John; Redelman, Doug

    2014-03-01

    This study was designed to improve identification of human blood monocytes by using antibodies to molecules that occur consistently on all stages of monocyte development and differentiation. We examined blood samples from 200 healthy adults without clinically diagnosed immunological abnormalities by flow cytometry (FCM) with multiple combinations of antibodies and with a hematology analyzer (Beckman LH750). CD91 (α2 -macroglobulin receptor) was expressed only by monocytes and to a consistent level among subjects [mean median fluorescence intensity (MFI) = 16.2 ± 3.2]. Notably, only 85.7 ± 5.82% of the CD91(+) monocytes expressed high levels of the classical monocyte marker CD14, with some CD91(+) CD16(+) cells having negligible CD14, indicating that substantial FCM under-counts will occur when monocytes are identified by high CD14. CD33 (receptor for sialyl conjugates) was co-expressed with CD91 on monocytes but CD33 expression varied by nearly ten-fold among subjects (mean MFI = 17.4 ± 7.7). In comparison to FCM analyses, the hematology analyzer systematically over-counted monocytes and eosinophils while lymphocyte and neutrophil differential values generally agreed with FCM methods. CD91 is a better marker to identify monocytes than CD14 or CD33. Furthermore, FCM (with anti-CD91) identifies monocytes better than a currently used clinical CBC instrument. Use of anti-CD91 together with anti-CD14 and anti-CD16 supports the identification of the diagnostically significant monocyte populations with variable expression of CD14 and CD16. Copyright © 2013 Clinical Cytometry Society.

  1. 77 FR 62520 - Prospective Grant of Exclusive License: The Development of Anti-CD22 Chimeric Antigen Receptors...

    Science.gov (United States)

    2012-10-15

    ... Exclusive License: The Development of Anti- CD22 Chimeric Antigen Receptors (CARs) for the Treatment of B... ``Anti-CD22 Chimeric Antigen Receptors'' [HHS Ref. E-265-2011/0-US-01], and (b) U.S. Patent Application... CD22 on their cell surface using chimeric antigen receptors which contain the HA22 or BL22 antibody...

  2. Heterogeneity of Human Neutrophil CD177 Expression Results from CD177P1 Pseudogene Conversion.

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    Zuopeng Wu

    2016-05-01

    Full Text Available Most humans harbor both CD177neg and CD177pos neutrophils but 1-10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1, which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation.

  3. Construction and Characterization of a Humanized Anti-Epstein-Barr Virus gp350 Antibody with Neutralizing Activity in Cell Culture

    Directory of Open Access Journals (Sweden)

    Jerome E. Tanner

    2018-04-01

    Full Text Available Acute Epstein-Barr virus (EBV infection in immunosuppressed transplant patients can give rise to a malignant B-cell proliferation known as post-transplant lymphoproliferative disease (PTLD. The EBV major virion surface glycoprotein (gp350 is a principal target of naturally occurring neutralizing antibodies and is viewed as the best target to prevent acute infection and PTLD in at-risk transplant recipients. We have constructed a humanized (hu version of the murine anti-gp350 neutralizing monoclonal antibody 72a1. The hu72a1 IgG1 antibody displayed no significant anti-mouse activity, recognized both gp350 and its splice variant gp220 as well as a gp350 peptide that was shown to constitute the principal EBV gp350 neutralizing epitope when tested in immunoassays. Hu72a1 antibody blocked in vitro EBV infection of B cells at a level which equaled that of a mouse-human chimeric 72a1 antibody construct. This work provides a further structural and immunological understanding of the 72a1 antibody interaction with EBV gp350, and constitutes a launch point for future anti-EBV therapeutic antibodies designed to block EBV infection and prevent PTLD while eliminating the deleterious antigenic murine features of the original 72a1 antibody.

  4. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weizao, E-mail: chenw3@mail.nih.gov [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Feng, Yang [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Wang, Yanping [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); The Basic Research Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Zhu, Zhongyu; Dimitrov, Dimiter S. [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  5. Biodistribution of 125I-labeled anti-endoglin antibody using SPECT/CT imaging: Impact of in vivo deiodination on tumor accumulation in mice

    International Nuclear Information System (INIS)

    Karmani, Linda; Levêque, Philippe; Bouzin, Caroline; Bol, Anne; Dieu, Marc; Walrand, Stephan; Vander Borght, Thierry; Feron, Olivier; Grégoire, Vincent; Bonifazi, Davide

    2016-01-01

    Introduction: Radiolabeled antibodies directed against endoglin (CD105) are promising tools for imaging and antiangiogenic cancer therapy. To validate iodinated antibodies as reliable tracers, we investigated the influence of the radiolabeling method (direct or indirect) on their in vivo stability. Methods: Anti-CD105 mAbs were radioiodinated directly using chloramine-T ( 125 I-anti-CD105-mAbs) or indirectly using D-KRYRR peptide as a linker ( 125 I-KRYRR-anti-CD105-mAbs). The biodistribution was studied in B16 tumor-bearing mice via SPECT/CT imaging. Results: Radioiodinated mAbs were stable in vitro. In vivo, thyroid showed the most important increase of uptake after 24 h for 125 I-anti-CD105-mAbs (91.9 ± 4.0%ID/ml) versus 125 I-KRYRR-anti-CD105-mAbs (4.4 ± 0.6%ID/ml). Tumor uptake of 125 I-anti-CD105-mAbs (0.9 ± 0.3%ID/ml) was significantly lower than that of 125 I-KRYRR-anti-CD105-mAbs (4.7 ± 0.2%ID/ml). Conclusions: An accurate characterization of the in vivo stability of radioiodinated mAbs and the choice of an appropriate method for the radioiodination are required, especially for novel targets. The indirect radioiodination of internalizing anti-CD105 mAbs leads to more stable tracer by decreasing in vivo deiodination and improves the tumor retention of radioiodinated mAbs. Advances in knowledge and implications for patient care: To date, the only antiangiogenic antibody approved for clinical indications is bevacizumab. There is a need to develop more antibodies that have targets highly expressed on tumor endothelium. CD105 represents a promising marker of angiogenesis, but its therapeutic relevance in cancer needs to be further investigated. In this context, this study suggests the potential use of indirectly iodinated anti-CD105 mAbs for tumor imaging and for therapeutic purposes.

  6. Contribution of enhanced engagement of antigen presentation machinery to the clinical immunogenicity of a human interleukin (IL)-21 receptor-blocking therapeutic antibody.

    Science.gov (United States)

    Xue, L; Hickling, T; Song, R; Nowak, J; Rup, B

    2016-01-01

    Reliable risk assessment for biotherapeutics requires accurate evaluation of risk factors associated with immunogenicity. Immunogenicity risk assessment tools were developed and applied to investigate the immunogenicity of a fully human therapeutic monoclonal antibody, ATR-107 [anti-interleukin (IL)-21 receptor] that elicited anti-drug antibodies (ADA) in 76% of healthy subjects in a Phase 1 study. Because the ATR-107 target is expressed on dendritic cells (DCs), the immunogenicity risk related to engagement with DC and antigen presentation pathways was studied. Despite the presence of IL-21R on DCs, ATR-107 did not bind to the DCs more extensively than the control therapeutic antibody (PF-1) that had elicited low clinical ADA incidence. However, ATR-107, but not the control therapeutic antibody, was translocated to the DC late endosomes, co-localized with intracellular antigen-D related (HLA-DR) molecules and presented a dominant T cell epitope overlapping the complementarity determining region 2 (CDR2) of the light chain. ATR-107 induced increased DC activation exemplified by up-regulation of DC surface expression of CD86, CD274 (PD-L1) and CD40, increased expansion of activated DC populations expressing CD86(hi), CD40(hi), CD83(hi), programmed death ligand 1 (PD-L1)(hi), HLA-DR(hi) or CCR7(hi), as well as elevated secretion of tumour necrosis factor (TNF)-α by DCs. DCs exposed to ATR-107 stimulated an autologous T cell proliferative response in human donor cells, in concert with the detection of immunoglobulin (Ig)G-type anti-ATR-107 antibody response in clinical samples. Collectively, the enhanced engagement of antigen presentation machinery by ATR-107 was suggested. The approaches and findings described in this study may be relevant to identifying lower immunogenicity risk targets and therapeutic molecules. © 2015 British Society for Immunology.

  7. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

    International Nuclear Information System (INIS)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo; Komiya, Eriko; Dang, Nam H.; Iwao, Noriaki; Ohnuma, Kei; Morimoto, Chikao

    2016-01-01

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

  8. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Komiya, Eriko [Department of Therapy Development and Innovation for Immune Disorders and Cancers, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Dang, Nam H. [Division of Hematology/Oncology, University of Florida, 1600 SW Archer Road- Box 100278, Room MSB M410A, Gainesville, FL, 32610 (United States); Iwao, Noriaki [Department of Hematology, School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Ohnuma, Kei, E-mail: kohnuma@juntendo.ac.jp [Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Morimoto, Chikao [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan)

    2016-05-20

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

  9. Elevated expression of CD147 in patients with endometriosis and its role in regulating apoptosis and migration of human endometrial cells.

    Science.gov (United States)

    Jin, Aihong; Chen, Hao; Wang, Chaoqun; Tsang, Lai Ling; Jiang, Xiaohua; Cai, Zhiming; Chan, Hsiao Chang; Zhou, Xiaping

    2014-06-01

    To examine the expression of CD147 in 60 human endometriosis lesions and how CD147 regulates migration and apoptosis in human uterine epithelial (HESs) cells. Experimental clinical study and laboratory-based investigation. Hospital and academic research center. Sixty women with chocolate cysts and 16 control women without endometriosis. Human uterine epithelial cells were treated with anti-CD147 antibody. Real-time polymerase chain reaction for detecting CD147 expression in 60 human endometriosis lesions; migration assay and CellTiter 96 AQueous One Solution Cell Proliferation Assay (MTS) assay for cell functional investigation; Western blot for detecting protein levels; gelatin zymography for evaluating the activity of matrix metalloproteinase-2 (MMP-2) in cultured cells. Expression of CD147 was significantly higher in ectopic endometrial tissues from patients with endometriosis than in normal endometrial tissues. Interference with CD147 function led to decreased migration and cell viability in HESs cells. Surprisingly, MMP-2 expression and activity were not changed after treating HESs cells with anti-CD147 antibody. Further examination revealed that immunodepletion of CD147 induced apoptosis in HESs cells, leading to the activation of caspase 3 and poly(ADP-ribose) polymerase. The results of the present study suggest that abnormally high expression of CD147 in ovarian endometriosis lesions with enhanced cell survival (reduced apoptosis) and migration, in an MMP-2-independent manner, may underlie the progression of endometriosis in humans. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  10. A simple physiologically based pharmacokinetic model evaluating the effect of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans

    Energy Technology Data Exchange (ETDEWEB)

    Saylor, Kyle, E-mail: saylor@vt.edu; Zhang, Chenming, E-mail: chzhang2@vt.edu

    2016-09-15

    Physiologically based pharmacokinetic (PBPK) modeling was applied to investigate the effects of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans. Successful construction of both rat and human models was achieved by fitting model outputs to published nicotine concentration time course data in the blood and in the brain. Key parameters presumed to have the most effect on the ability of these antibodies to prevent nicotine from entering the brain were selected for investigation using the human model. These parameters, which included antibody affinity for nicotine, antibody cross-reactivity with cotinine, and antibody concentration, were broken down into different, clinically-derived in silico treatment levels and fed into the human PBPK model. Model predictions suggested that all three parameters, in addition to smoking status, have a sizable impact on anti-nicotine antibodies' ability to prevent nicotine from entering the brain and that the antibodies elicited by current human vaccines do not have sufficient binding characteristics to reduce brain nicotine concentrations. If the antibody binding characteristics achieved in animal studies can similarly be achieved in human studies, however, nicotine vaccine efficacy in terms of brain nicotine concentration reduction is predicted to meet threshold values for alleviating nicotine dependence. - Highlights: • Modelling of nicotine disposition in the presence of anti-nicotine antibodies • Key vaccine efficacy factors are evaluated in silico in rats and in humans. • Model predicts insufficient antibody binding in past human nicotine vaccines. • Improving immunogenicity and antibody specificity may lead to vaccine success.

  11. A simple physiologically based pharmacokinetic model evaluating the effect of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans

    International Nuclear Information System (INIS)

    Saylor, Kyle; Zhang, Chenming

    2016-01-01

    Physiologically based pharmacokinetic (PBPK) modeling was applied to investigate the effects of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans. Successful construction of both rat and human models was achieved by fitting model outputs to published nicotine concentration time course data in the blood and in the brain. Key parameters presumed to have the most effect on the ability of these antibodies to prevent nicotine from entering the brain were selected for investigation using the human model. These parameters, which included antibody affinity for nicotine, antibody cross-reactivity with cotinine, and antibody concentration, were broken down into different, clinically-derived in silico treatment levels and fed into the human PBPK model. Model predictions suggested that all three parameters, in addition to smoking status, have a sizable impact on anti-nicotine antibodies' ability to prevent nicotine from entering the brain and that the antibodies elicited by current human vaccines do not have sufficient binding characteristics to reduce brain nicotine concentrations. If the antibody binding characteristics achieved in animal studies can similarly be achieved in human studies, however, nicotine vaccine efficacy in terms of brain nicotine concentration reduction is predicted to meet threshold values for alleviating nicotine dependence. - Highlights: • Modelling of nicotine disposition in the presence of anti-nicotine antibodies • Key vaccine efficacy factors are evaluated in silico in rats and in humans. • Model predicts insufficient antibody binding in past human nicotine vaccines. • Improving immunogenicity and antibody specificity may lead to vaccine success.

  12. Anti-lymphoma efficacy comparison of anti-Cd20 monoclonal antibody-targeted and non-targeted star-shaped polymer-prodrug conjugates

    Czech Academy of Sciences Publication Activity Database

    Lidický, Ondřej; Janoušková, Olga; Strohalm, Jiří; Alam, M.; Klener, P.; Etrych, Tomáš

    2015-01-01

    Roč. 20, č. 11 (2015), s. 19849-19864 ISSN 1420-3049 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109; GA ČR(CZ) GA15-02986S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : HPMA copolymers * drug delivery systems * doxorubicin Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.465, year: 2015

  13. Ocaratuzumab, an Fc-engineered antibody demonstrates enhanced antibody-dependent cell-mediated cytotoxicity in chronic lymphocytic leukemia.

    Science.gov (United States)

    Cheney, Carolyn M; Stephens, Deborah M; Mo, Xiaokui; Rafiq, Sarwish; Butchar, Jonathan; Flynn, Joseph M; Jones, Jeffrey A; Maddocks, Kami; O'Reilly, Adrienne; Ramachandran, Abhijit; Tridandapani, Susheela; Muthusamy, Natarajan; Byrd, John C

    2014-01-01

    Chronic lymphocytic leukemia (CLL) is common in both developed and developing nations where the need for inexpensive and convenient administration of therapy is apparent. Ocaratuzumab is a novel Fc-engineered humanized IgG1 anti-CD20 monoclonal antibody (mAb) designed for effective antibody-dependent cell-mediated cytotoxicity (ADCC) at very low concentrations that may facilitate sub-cutaneous (vs. intravenous) dosing. Here, we report ocaratuzumab's potency against CLL cells. In vitro assessment of ocaratuzumab's direct cytotoxicity (DC), complement-dependent cytotoxicity (CDC), antibody-dependent cellular phagocytosis (ADCP), and ADCC was performed on CLL cells. Ocaratuzumab induced DC, CDC, and ADCP similarly to rituximab or ofatumumab (anti-CD20 mAbs). However, ocaratuzumab showed an advantage in NK cell-mediated ADCC over these antibodies. In allogeneic ADCC, [E:T (effector:target) ratios = 25:1, 12:1, 6:1], ocaratuzumab (10 µg/mL) improved ADCC by ~3-fold compared with rituximab or ofatumumab (P<0.001 all tested E:T ratios). Notably, the superiority of ocaratuzumab-induced ADCC was observed at low concentrations (0.1-10 ug/ml; P<0.03; allogeneic assays). In extended allogeneic ADCC E:T titration, ocaratuzumab (0.1 µg/mL) demonstrated 19.4% more cytotoxicity than rituximab (E:T = 0.38:1; P = 0.0066) and 21.5% more cytotoxicity than ofatumumab (E:T = 1.5:1; P = 0.0015). In autologous ADCC, ocaratuzumab (10 µg/mL) demonstrated ~1.5-fold increase in cytotoxicity compared with rituximab or ofatumumab at all E:T ratios tested (E:Ts = 25:1,12:1,6:1; all P<0.001). Obinutuzumab, a glyco-engineered anti-CD20 mAb, showed no improvement in ADCC activity compared with ocaratuzumab. The enhanced ADCC of ocaratuzumab suggests that it may be effective at low concentrations. If supported by clinical investigation, this feature could potentially allow for subcutaneous dosing at low doses that could expand the potential of administering chemoimmunotherapy in developing

  14. Anti-smooth muscle antibody

    Science.gov (United States)

    ... gov/ency/article/003531.htm Anti-smooth muscle antibody To use the sharing features on this page, please enable JavaScript. Anti-smooth muscle antibody is a blood test that detects the presence ...

  15. Clinical impact of B-cell depletion with the anti-CD20 antibody rituximab in chronic fatigue syndrome: a preliminary case series

    Directory of Open Access Journals (Sweden)

    Mella Olav

    2009-07-01

    Full Text Available Abstract Background Chronic fatigue syndrome (CFS is a disease of unknown aetiology. A patient with CFS had unexpected, marked recovery of CFS symptoms lasting for five months during and after cytotoxic chemotherapy for Hodgkin's disease. We reasoned that the transient CFS recovery was related to methotrexate treatment, which induces immunomodulation in part through B-cell depletion. Methods In a case series, this patient and two additional CFS patients were B-cell depleted by infusion of the monoclonal anti-CD20 antibody rituximab. Results All three had improvement of all CFS symptoms. Patients 1 and 2 had major amelioration from 6 weeks after intervention, patient 3 slight improvement from the same time, but then improved markedly from 26 weeks after intervention. The symptomatic effect lasted until weeks 16, 18 and 44, respectively. At relapse, all were retreated with a single (patient 1 or double rituximab infusion (patients 2 and 3. Again, all three had marked symptom improvement, mimicking their first response. After new symptom recurrence, patients 1 and 2 were given weekly oral methotrexate, patient 1 having effect also from this agent. Patients 1 and 2 were again treated for a third rituximab infusion after new relapse, again with a marked clinical benefit. No unexpected toxicity was seen. Conclusion These observations suggest that B-lymphocytes are involved in CFS pathogenesis for a subset of patients. Benefit for all CFS symptoms, the delayed symptom relief following B-cell depletion, the kinetics of relapses, and the effect also from methotrexate treatment, provide suggestive evidence that B-cells play a significant role in the ongoing clinical features, and that CFS may be amenable to therapeutic interventions aimed at modifying B-cell number and function. More systematic investigations of this therapeutic strategy, and of its biological basis, are now needed.

  16. Anti-Transglutaminase 6 Antibodies in Children and Young Adults with Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Reidun Stenberg

    2014-01-01

    Full Text Available Objectives. We have previously reported a high prevalence of gluten-related serological markers (GRSM in children and young adults with cerebral palsy (CP. The majority had no enteropathy to suggest coeliac disease (CD. Antibodies against transglutaminase 6 (anti-TG6 represent a new marker associated with gluten-related neurological dysfunction. The aim of this study was to investigate the prevalence of anti-TG6 antibodies in this group of individuals with an early neurological injury resulting in CP. Materials and Methods. Sera from 96 patients with CP and 36 controls were analysed for IgA/IgG class anti-TG6 by ELISA. Results. Anti-TG6 antibodies were found in 12/96 (13% of patients with CP compared to 2/36 (6% in controls. The tetraplegic subgroup of CP had a significantly higher prevalence of anti-TG6 antibodies 6/17 (35% compared to the other subgroups and controls. There was no correlation of anti-TG6 autoantibodies with seropositivity to food proteins including gliadin. Conclusions. An early brain insult and associated inflammation may predispose to future development of TG6 autoimmunity.

  17. Macrophage-specific nanotechnology-driven CD163 overexpression in human macrophages results in an M2 phenotype under inflammatory conditions.

    Science.gov (United States)

    Alvarado-Vazquez, Perla Abigail; Bernal, Laura; Paige, Candler A; Grosick, Rachel L; Moracho Vilrriales, Carolina; Ferreira, David Wilson; Ulecia-Morón, Cristina; Romero-Sandoval, E Alfonso

    2017-08-01

    M1 macrophages release proinflammatory factors during inflammation. They transit to an M2 phenotype and release anti-inflammatory factors to resolve inflammation. An imbalance in the transition from M1 to M2 phenotype in macrophages contributes to the development of persistent inflammation. CD163, a member of the scavenger receptor cysteine-rich family, is an M2 macrophage marker. The functional role of CD163 during the resolution of inflammation is not completely known. We postulate that CD163 contributes to the transition from M1 to M2 phenotype in macrophages. We induced CD163 gene in THP-1 and primary human macrophages using polyethylenimine nanoparticles grafted with a mannose ligand (Man-PEI). This nanoparticle specifically targets cells of monocytic origin via mannose receptors. Cells were challenged with a single or a double stimulation of lipopolysaccharide (LPS). A CD163 or empty plasmid was complexed with Man-PEI nanoparticles for cell transfections. Quantitative RT-PCR, immunocytochemistry, and ELISAs were used for molecular assessments. CD163-overexpressing macrophages displayed reduced levels of tumor necrosis factor-alpha (TNF)-α and monocytes chemoattractant protein (MCP)-1 after a single stimulation with LPS. Following a double stimulation paradigm, CD163-overexpressing macrophages showed an increase of interleukin (IL)-10 and IL-1ra and a reduction of MCP-1. This anti-inflammatory phenotype was partially blocked by an anti-CD163 antibody (effects on IL-10 and IL-1ra). A decrease in the release of TNF-α, IL-1β, and IL-6 was observed in CD163-overexpressing human primary macrophages. The release of IL-6 was blocked by an anti-CD163 antibody in the CD163-overexpressing group. Our data show that the induction of the CD163 gene in human macrophages under inflammatory conditions produces changes in cytokine secretion in favor of an anti-inflammatory phenotype. Targeting macrophages to induce CD163 using cell-directed nanotechnology is an attractive

  18. Effects of anti-CD40 mAb on inducing malignant B cells proliferation arrest and apoptosis and its mechanism

    International Nuclear Information System (INIS)

    Tang Lin; Zhuang Yumei; Zhou Zhaohua; Yu Gehua; Pan Jianzhong; Zhang Xueguang

    2002-01-01

    Objective: To study the expression of CD 40 molecule and the biological effects mediated by CD 40 molecules on malignant B cells. Methods: Agonistic anti-human CD 40 monoclonal antibody (clone 5C11) was added to cell culture system. Cell counting, PI staining, Annexin-V staining and flow cytometric analysis were used to study the behavior of malignant B cell lines after treatment with mAb clone 5C11. Results: 5C11 induced homotypic aggregation and proliferation arrest and mediated apoptosis in multiple myeloma cell line XG2 that expressed CD 40 strongly; 5C11 induced B lymphoma cell line Daudi homotypic aggregation and proliferation arrest and apoptosis, the apoptosis of XG2 and Daudi by CD40 activation was not mediated by TNF. Conclusion: Agonistic anti-CD 40 mAb 5C11 can inhibit the proliferation of malignant B cells by inducing them to die apoplectically

  19. 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.

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

    International Nuclear Information System (INIS)

    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

    2000-01-01

    The anti-human epidermal growth factor receptor (EGF-R) humanized antibody h-R3 (IgG 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 μg/100 μCi of 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 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

  1. Disseminated Infections with Talaromyces marneffei in Non-AIDS Patients Given Monoclonal Antibodies against CD20 and Kinase Inhibitors

    OpenAIRE

    Chan, Jasper F.W.; Chan, Thomas S.Y.; Gill, Harinder; Lam, Frank Y.F.; Trendell-Smith, Nigel J.; Sridhar, Siddharth; Tse, Herman; Lau, Susanna K.P.; Hung, Ivan F.N.; Yuen, Kwok-Yung; Woo, Patrick C.Y.

    2015-01-01

    Infections with the fungus Talaromyces (formerly Penicillium) marneffei are rare in patients who do not have AIDS. We report disseminated T. marneffei infection in 4 hematology patients without AIDS who received targeted therapy with monoclonal antibodies against CD20 or kinase inhibitors during the past 2 years. Clinicians should be aware of this emerging complication, especially in patients from disease-endemic regions.

  2. Pulmonary biology of anti-interleukin 5 antibodies

    Directory of Open Access Journals (Sweden)

    RW Egan

    1997-12-01

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

  3. Pretargeting vs. direct targeting of human betalox5 islet cells subcutaneously implanted in mice using an anti-human islet cell antibody

    International Nuclear Information System (INIS)

    Liu Guozheng; Dou Shuping; Akalin, Ali; Rusckowski, Mary; Streeter, Philip R.; Shultz, Leonard D.; Greiner, Dale L.

    2012-01-01

    Introduction: We previously demonstrated MORF/cMORF pretargeting of human islets and betalox 5 cells (a human beta cell line) transplanted subcutaneously in mice with the anti-human islet antibody, HPi1. We now compare pretargeting with direct targeting in the beta cell transplant model to evaluate the degree to which target/non-target (T/NT) ratios may be improved by pretargeting. Methods: Specific binding of an anti-human islet antibody HPi1 to the beta cells transplanted subcutaneously in mice was examined against a negative control antibody. We then compared pretargeting by MORF-HPi1 plus 111 In-labeled cMORF to direct targeting by 111 In-labeled HPi1. Results: HPi1 binding to betalox5 human cells in the transplant was shown by immunofluorescence. Normal organ 111 In backgrounds by pretargeting were always lower, although target accumulations were similar. More importantly, the transplant to pancreas and liver ratios was, respectively, 26 and 10 by pretargeting as compared to 9 and 0.6 by direct targeting. Conclusions: Pretargeting greatly improves the T/NT ratios, and based on the estimated endocrine to exocrine ratio within a pancreas, pretargeting may be approaching the sensitivity required for successful imaging of human islets within this organ.

  4. Detection of anti-lactoferrin antibodies and anti-myeloperoxidase antibodies in autoimmune hepatitis: a retrospective study.

    Science.gov (United States)

    Tan, Liming; Zhang, Yuhong; Peng, Weihua; Chen, Juanjuan; Li, Hua; Ming, Feng

    2014-01-01

    Anti-lactoferrin antibodies (ALA) and anti-myeloperoxidase antibodies (AMPA) are specific serological markers for autoimmune hepatitis (AIH). The project aimed to detect ALA and AMPA and explore their clinical significances in AIH patients. 59 AIH patients, 217 non AIH patients, and 50 healthy controls were enrolled in this study. ALA and AMPA were detected by ELISA. Antineutropil cytoplasmic antibodies (ANCA) and anti-smooth muscle antibodies (ASMA) were examined by indirect immunofluorescence. Antimitochondrial antibody M2 subtype (AMA-M2), anti-liver kidney microsomal antibody Type 1 (LKM1), anti-liver cytosol antibody Type 1 (LC1), and anti-soluble liver antigen/liver-pancreas antibodies (SLA/LP) were tested by immunoblot. The positivity for ALA was 18.6% in AIH group, only one patient in non-AIH group was positive for ALA; the positivity for AMPA was 59.3% in AIH group, with significant differences (P < 0.01) compared with other groups. The specificities for ALA and AMPA were 99.63% and 97.75%; the sensitivities were 18.64% and 59.32%; and the accuracy rates were 84.97% and 90.80%, respectively. A certain correlation was observed between ALA and SLA/LP, AMPA and ANCA, ASMA in AIH group. ALA and AMPA were associated with AIH, and had high clinical diagnostic value. Co-detection with other relative autoantibodies could play an important role in differential diagnosis of AIH.

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

    Science.gov (United States)

    Kirley, Terence L; Norman, Andrew B

    2015-01-01

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

  6. Radioimmunodetection of human leukemia with anti-interleukin-2 receptor antibody in severe combined immunodeficiency mice

    International Nuclear Information System (INIS)

    Hosono, Makoto; Takaori-Kondo, Akifumi; Zheng-Sheng, Yao; Kobayashi, Hisataka; Hosono, Masako N.; Sakahara, Harumi; Imada, Kazunori; Okuma, Minoru; Uchiyama, Takashi; Konishi, Junji

    1995-01-01

    Anti-Tac monoclonal antibody recognizes human interleukin-2 receptor, which is overexpressed in leukemic cells of most adult T-cell leukemia (ATL) patients. To examine the potency of anti-Tac for targeting of ATL, biodistributions of intravenously administered 125 I- and 111 In-labeled anti-Tac were examined in severe combined immunodeficiency (SCID) mice inoculated with ATL cells. Significant amounts of radiolabeled anti-Tac were found in the spleen and thymus. The trafficking of ATL cells in SCID mice was detected using 111 In-oxine-labeled ATL cells. These results were coincident with the histologically confirmed infiltration of ATL cells. The radiolabeled anti-Tac seemed potent for targeting of ATL

  7. TLR5 signaling enhances the proliferation of human allogeneic CD40-activated B cell induced CD4hiCD25+ regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Ping-Lung Chan

    Full Text Available Although diverse functions of different toll-like receptors (TLR on human natural regulatory T cells have been demonstrated recently, the role of TLR-related signals on human induced regulatory T cells remain elusive. Previously our group developed an ex vivo high-efficient system in generating human alloantigen-specific CD4(hiCD25(+ regulatory T cells from naïve CD4(+CD25(- T cells using allogeneic CD40-activated B cells as stimulators. In this study, we investigated the role of TLR5-related signals on the generation and function of these novel CD4(hiCD25(+ regulatory T cells. It was found that induced CD4(hiCD25(+ regulatory T cells expressed an up-regulated level of TLR5 compared to their precursors. The blockade of TLR5 using anti-TLR5 antibodies during the co-culture decreased CD4(hiCD25(+ regulatory T cells proliferation by induction of S phase arrest. The S phase arrest was associated with reduced ERK1/2 phosphorylation. However, TLR5 blockade did not decrease the CTLA-4, GITR and FOXP3 expressions, and the suppressive function of CD4(hiCD25(+ regulatory T cells. In conclusion, we discovered a novel function of TLR5-related signaling in enhancing the proliferation of CD4(hiCD25(+ regulatory T cells by promoting S phase progress but not involved in the suppressive function of human CD40-activated B cell-induced CD4(hiCD25(+ regulatory T cells, suggesting a novel role of TLR5-related signals in the generation of induced regulatory T cells.

  8. [Construction of the lentiviral expression vector for anti-p185(erbB2) mouse/human chimeric antibody].

    Science.gov (United States)

    Liu, Fang; Li, Li; Zhang, Wei; Wang, Qi

    2013-04-01

    This research was to construct the lentiviral expression vector for anti- p185(erbB2) mouse/human chimeric antibody and to determine the expression of the chimeric antibody gene in 293T cells transfected with this vector. The genes (vL and vH) coding light and heavy chain of variable regions of anti-p185(erbB2) mAb and the constant regions of human IgG1 (kappa and gamma1) were cloned with PCR method. The target genes were assembled by three-primers PCR method to obtain the chimeric light chain (L) and the chimeric heavy chain (H). Both chains inserted into the down stream and upper stream of IRES gene of the plasmid pVAX1/IRES respectively. We digested the plasmid pVAX1/ H-IRES-L with endoenzyme and subcloned H-IRES-L into the lentiviral vector pWPI. The enzyme digestion and sequence analysis showed that the lentiviral expression vector pWPI/H-IRES-L was constructed correctly. Then, it was transfected into 293T cells and after 48h, GFP protein expression in 293T cells were detected by fluorescent microscope and the chimeric antibody expression was detected by RT-PCR and direct ELISA. The results showed that after 293T cells were transfected with recombination plasmid, both light and heavy chains of the chimeric antibody genes could express together. The chimeric antibody expressed could bind to p185(erbB2) specifically. This research may lay a sound foundation for further study of anti-p185(erbB2) engineered antibody.

  9. Evaluation of cell cycle changes activated by the administration of {sup 177}Lu-DOTA-antiCD20; Evaluacion de cambios en el ciclo celular activados por la administracion de {sup 177}Lu-DOTA-antiCD20

    Energy Technology Data Exchange (ETDEWEB)

    Ramos B, J. C.

    2016-07-01

    In the present project, cytometric evaluation of cell cycle changes induced by the {sup 177}Lu-DOTA-antiCD20 thermostatic radiopharmaceutical was performed, in which a cell culture of Raji cells from Burkitts lymphoma were used, which are CD20+; for flow cytometry different parameters were measured in which the cells were synchronized in G0/G1 and G2/M, to calculate the dose to nucleus that were given to the cells the Monte Carlo method was used at a dose interval from 1 to 5 Gy. The purpose of this work is to be able to observe by flow cytometry the arrest in the cell cycle with a lower dose interval than the one applied in other papers. (Author)

  10. Clearance of Human IgG1-Sensitised Red Blood Cells In Vivo in Humans Relates to the In Vitro Properties of Antibodies from Alternative Cell Lines

    Science.gov (United States)

    Armour, Kathryn L.; Smith, Cheryl S.; Ip, Natasha C. Y.; Ellison, Cara J.; Kirton, Christopher M.; Wilkes, Anthony M.; Williamson, Lorna M.; Clark, Michael R.

    2014-01-01

    We previously produced a recombinant version of the human anti-RhD antibody Fog-1 in the rat myeloma cell line, YB2/0. When human, autologous RhD-positive red blood cells (RBC) were sensitised with this IgG1 antibody and re-injected, they were cleared much more rapidly from the circulation than had been seen earlier with the original human-mouse heterohybridoma-produced Fog-1. Since the IgG have the same amino acid sequence, this disparity is likely to be due to alternative glycosylation that results from the rat and mouse cell lines. By comparing the in vitro properties of YB2/0-produced Fog-1 IgG1 and the same antibody produced in the mouse myeloma cell line NS0, we now have a unique opportunity to pinpoint the cause of the difference in ability to clear RBC in vivo. Using transfected cell lines that express single human FcγR, we showed that IgG1 made in YB2/0 and NS0 cell lines bound equally well to receptors of the FcγRI and FcγRII classes but that the YB2/0 antibody was superior in FcγRIII binding. When measuring complexed IgG binding, the difference was 45-fold for FcγRIIIa 158F, 20-fold for FcγRIIIa 158V and approximately 40-fold for FcγRIIIb. The dissimilarity was greater at 100-fold in monomeric IgG binding assays with FcγRIIIa. When used to sensitise RBC, the YB2/0 IgG1 generated 100-fold greater human NK cell antibody-dependent cell-mediated cytotoxicity and had a 103-fold advantage over the NS0 antibody in activating NK cells, as detected by CD54 levels. In assays of monocyte activation and macrophage adherence/phagocytosis, where FcγRI plays major roles, RBC sensitised with the two antibodies produced much more similar results. Thus, the alternative glycosylation profiles of the Fog-1 antibodies affect only FcγRIII binding and FcγRIII-mediated functions. Relating this to the in vivo studies confirms the importance of FcγRIII in RBC clearance. PMID:25302805

  11. Clearance of human IgG1-sensitised red blood cells in vivo in humans relates to the in vitro properties of antibodies from alternative cell lines.

    Directory of Open Access Journals (Sweden)

    Kathryn L Armour

    Full Text Available We previously produced a recombinant version of the human anti-RhD antibody Fog-1 in the rat myeloma cell line, YB2/0. When human, autologous RhD-positive red blood cells (RBC were sensitised with this IgG1 antibody and re-injected, they were cleared much more rapidly from the circulation than had been seen earlier with the original human-mouse heterohybridoma-produced Fog-1. Since the IgG have the same amino acid sequence, this disparity is likely to be due to alternative glycosylation that results from the rat and mouse cell lines. By comparing the in vitro properties of YB2/0-produced Fog-1 IgG1 and the same antibody produced in the mouse myeloma cell line NS0, we now have a unique opportunity to pinpoint the cause of the difference in ability to clear RBC in vivo. Using transfected cell lines that express single human FcγR, we showed that IgG1 made in YB2/0 and NS0 cell lines bound equally well to receptors of the FcγRI and FcγRII classes but that the YB2/0 antibody was superior in FcγRIII binding. When measuring complexed IgG binding, the difference was 45-fold for FcγRIIIa 158F, 20-fold for FcγRIIIa 158V and approximately 40-fold for FcγRIIIb. The dissimilarity was greater at 100-fold in monomeric IgG binding assays with FcγRIIIa. When used to sensitise RBC, the YB2/0 IgG1 generated 100-fold greater human NK cell antibody-dependent cell-mediated cytotoxicity and had a 103-fold advantage over the NS0 antibody in activating NK cells, as detected by CD54 levels. In assays of monocyte activation and macrophage adherence/phagocytosis, where FcγRI plays major roles, RBC sensitised with the two antibodies produced much more similar results. Thus, the alternative glycosylation profiles of the Fog-1 antibodies affect only FcγRIII binding and FcγRIII-mediated functions. Relating this to the in vivo studies confirms the importance of FcγRIII in RBC clearance.

  12. Kidney graft recipients with pretransplantation HLA CLASS I antibodies and high soluble CD30 are at high risk for graft loss.

    Science.gov (United States)

    Rodríguez, Libia M; París, Sara C; Arbeláez, Mario; Cotes, José M; Süsal, Caner; Torres, Yolanda; García, Luís F

    2007-08-01

    In the present study, we investigated whether pretransplantation HLA class I and class II antibodies and pretransplantation levels of soluble CD30 (sCD30) and IgA anti-Fab autoantibodies are predictive of kidney allograft survival. Pretransplantation sera of 504 deceased-donor kidney recipients were tested for IgG HLA class I and class II antibodies, sCD30, and IgA anti-Fab levels using the CTS 4 ELISA kit. Kidney graft survival was estimated by Kaplan-Meier method and multivariate Cox regression. Regardless of the presence of HLA class II antibodies, recipients with high HLA class I reactivity had lower 1-year graft survival than recipients with low reactivity (p sCD30 had lower 5-year graft survival rate than those with low sCD30 (p sCD30 effect was observed in presensitized and nonsensitized recipients, demonstrated a synergistic effect with HLA class I antibodies (p kidney graft survival. Our results indicate that high pretransplantation sCD30 levels and HLA class I positivity increase the risk of kidney graft loss regardless of other factors. Consequently, such determinations should be routinely performed to estimate recipients' risks of graft rejection before transplantation.

  13. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Science.gov (United States)

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

    2011-01-01

    To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ) was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  14. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Directory of Open Access Journals (Sweden)

    Samuele E Burastero

    Full Text Available To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  15. Effectiveness and side effects of anti-CD20 therapy for autoantibody-mediated blistering skin diseases: A comprehensive survey of 71 consecutive patients from the Initial use to 2007

    Directory of Open Access Journals (Sweden)

    Jennifer D Peterson

    2008-11-01

    Full Text Available Jennifer D Peterson1, Lawrence S Chan2,3,41Department of Dermatology, Texas Tech University Health Sciences Center at Lubbock, Lubbock, TX, USA; 2Department of Dermatology; 3Department of Microbiology/Immunology, University of Illinois at Chicago, Chicago, IL, USA; 4Medicine Service, Jesse Brown VA Medical Center, Chicago, IL, USAAbstract: In order to examine the efficacy and side effects of the monoclonal antibody anti-CD20 (rituximab on autoimmune blistering skin diseases, we performed a comprehensive survey of 71 consecutive patients from initial use up to 2007, using the PubMed database. A heterogeneous group of patients, including 51 patients with pemphigus vulgaris, one with pemphigus vegetans, nine with pemphigus foliaceus, five with paraneoplastic pemphigus, four with epidermolysis bullosa acquisita, and one with both bullous pemphigoid and graft vs host disease was included in this survey. Overall the monoclonal antibody seems to be effective in that 69% of patients showed complete response, 25% of patients showed partial response, whereas 6% of patients showed progressive disease. Six deaths occurred in association with the treatment, with four of these deaths in patients with paraneoplastic pemphigus, a disease characteristically resistant to conventional medication and with a high mortality rate. Of note, 11 patients who received combined rituximab and intravenous immune globulin treatments had the best outcome: complete response without any serious side effects. Therefore further investigation on rituximab with controlled clinical trial is a worthy pursuit.Keywords: blistering diseases, skin, anti-CD20, pemphigus, epidermolysis bullosa acquisita

  16. Epidermal growth factor receptor inhibition by anti-CD147 therapy in cutaneous squamous cell carcinoma.

    Science.gov (United States)

    Frederick, John W; Sweeny, Larissa; Hartman, Yolanda; Zhou, Tong; Rosenthal, Eben L

    2016-02-01

    Advanced cutaneous squamous cell carcinoma (SCC) is an uncommon and aggressive malignancy. As a result, there is limited understanding of its biology and pathogenesis. CD147 and epidermal growth factor receptor (EGFR) have been identified as oncologically important targets, but their relationship remains undefined in cutaneous SCC. Multiple cutaneous SCC cell lines (Colo-16, SRB-1, and SRB-12), were treated in vitro with a range of chimeric anti-CD147 monoclonal antibody (mAb) (0, 50, 100, and 200 µg/mL) or transfected with a small interfering RNA against CD147 (SiCD147). Cell proliferation, migration (scratch wound healing assay), and protein expression was then assessed. In vivo, Colo-16 flank xenografts were treated anti-CD147 mAb (150 µg i.p. triweekly). After treatment with anti-CD147 (200 µg/mL), there was a significant decrease in proliferation for all cell lines relative to controls (p CD147 (200 µg/mL) resulted in decreased cell migration for all cell lines, with an average of 43% reduction in closure compared to controls (p CD147 antibody therapy and siRNA mediated reduction in CD147 expression were both found to decrease protein expression of EGFR, which correlated with a reduction in downstream total and phosphorylated protein kinase B (pAKT). Tumor growth in vivo was reduced for both the anti-CD147 treatment group and the SiCD147 group relative to controls. Inhibition and downregulation of CD147 in cutaneous SCC resulted in suppression of the malignant phenotype in vitro and in vivo, which may be mediated in part by an alteration in EGFR expression. As a result, CD147 may serve as a potential therapeutic target for advanced cutaneous SCC. © 2014 Wiley Periodicals, Inc.

  17. Human endothelial precursor cells express tumor endothelial marker 1/endosialin/CD248.

    Science.gov (United States)

    Bagley, Rebecca G; Rouleau, Cecile; St Martin, Thia; Boutin, Paula; Weber, William; Ruzek, Melanie; Honma, Nakayuki; Nacht, Mariana; Shankara, Srinivas; Kataoka, Shiro; Ishida, Isao; Roberts, Bruce L; Teicher, Beverly A

    2008-08-01

    Angiogenesis occurs during normal physiologic processes as well as under pathologic conditions such as tumor growth. Serial analysis of gene expression profiling revealed genes [tumor endothelial markers (TEM)] that are overexpressed in tumor endothelial cells compared with normal adult endothelial cells. Because blood vessel development of malignant tumors under certain conditions may include endothelial precursor cells (EPC) recruited from bone marrow, we investigated TEM expression in EPC. The expression of TEM1 or endosialin (CD248) and other TEM has been discovered in a population of vascular endothelial growth factor receptor 2+/CD31+/CD45-/VE-cadherin+ EPC derived from human CD133+/CD34+ cells. EPC share some properties with fully differentiated endothelial cells from normal tissue, yet reverse transcription-PCR and flow cytometry reveal that EPC express higher levels of endosialin at the molecular and protein levels. The elevated expression of endosialin in EPC versus mature endothelial cells suggests that endosialin is involved in the earlier stages of tumor angiogenesis. Anti-endosialin antibodies inhibited EPC migration and tube formation in vitro. In vivo, immunohistochemistry indicated that human EPC continued to express endosialin protein in a Matrigel plug angiogenesis assay established in nude mice. Anti-endosialin antibodies delivered systemically at 25 mg/kg were also able to inhibit circulating murine EPC in nude mice bearing s.c. SKNAS tumors. EPC and bone marrow-derived cells have been shown previously to incorporate into malignant blood vessels in some instances, yet they remain controversial in the field. The data presented here on endothelial genes that are up-regulated in tumor vasculature and in EPC support the hypothesis that the angiogenesis process in cancer can involve EPC.

  18. Preparation and characterization of chimeric CD19 monoclonal antibody

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  19. Induction of human immunodeficiency virus neutralizing antibodies using fusion complexes.

    Science.gov (United States)

    Zipeto, Donato; Matucci, Andrea; Ripamonti, Chiara; Scarlatti, Gabriella; Rossolillo, Paola; Turci, Marco; Sartoris, Silvia; Tridente, Giuseppe; Bertazzoni, Umberto

    2006-05-01

    Human immunodeficiency virus-1 (HIV-1) infects cells by membrane fusion that is mediated by the envelope proteins gp120/gp41 and the cellular receptors CD4 and CCR5. During this process, some conserved viral epitopes are temporarily exposed and may induce a neutralizing antibody response when fixed in the fusogenic conformation. These transient structures are conserved and may be effective antigens for use in an anti-HIV-1 vaccine. In this study we tested different conditions of preparation of fusion complexes inducing neutralizing antibodies against both R5 and X4 tropic HIV-1 strains. Cell lines expressing HIV-1 gp120/gp41 and CD4-CCR5 were prepared and conditions for producing fusion complexes were tested. Complexes produced at different temperature and fixative combinations were used to immunize mice. Results indicated that (a) fusion complexes prepared at either 21 degrees C, 30 degrees C or 37 degrees C were immunogenic and induced neutralizing antibodies against both R5 and X4 HIV-1 heterologous isolates; (b) after extensive purification of antibodies there was no cytotoxic effect; (c) complexes prepared at 37 degrees C were more immunogenic and induced higher titers of neutralizing antibodies than complexes prepared at either 21 degrees C or 30 degrees C; (d) the fixative used did not affect the titer of neutralizing antibodies except for glutaraldehyde which was ineffective; (e) the neutralizing activity was retained after CD4-CCR5 antibody removal. The production of higher titers of neutralizing antibody with fusion complexes prepared at 37 degrees C, as compared to lower temperatures, may be related to the induction of antibodies against many different conformation intermediates that subsequently act synergistically at different steps in the fusion process.

  20. Synergistic reversal of type 1 diabetes in NOD mice with anti-CD3 and interleukin-1 blockade

    DEFF Research Database (Denmark)

    Ablamunits, Vitaly; Henegariu, Octavian; Hansen, Jakob Bondo

    2012-01-01

    (ab')(2) fragments of anti-CD3 mAb with or without IL-1 receptor antagonist (IL-1RA), or anti-IL-1ß mAb. We studied the reversal of diabetes and effects of treatment on the immune system. Mice that received a combination of anti-CD3 mAb with IL-1RA showed a more rapid rate of remission of diabetes than......Inflammatory cytokines are involved in autoimmune diabetes: among the most prominent is interleukin (IL)-1ß. We postulated that blockade of IL-1ß would modulate the effects of anti-CD3 monoclonal antibody (mAb) in treating diabetes in NOD mice. To test this, we treated hyperglycemic NOD mice with F...... arginase expression in macrophages and dendritic cells, and had delayed adoptive transfer of diabetes. After 1 month, there were increased concentrations of IgG1 isotype antibodies and reduced intrapancreatic expression of IFN-¿, IL-6, and IL-17 despite normal splenocyte cytokine secretion. These studies...

  1. Anti-HIV Antibody Responses and the HIV Reservoir Size during Antiretroviral Therapy.

    Directory of Open Access Journals (Sweden)

    Sulggi A Lee

    Full Text Available A major challenge to HIV eradication strategies is the lack of an accurate measurement of the total burden of replication-competent HIV (the "reservoir". We assessed the association of anti-HIV antibody responses and the estimated size of the reservoir during antiretroviral therapy (ART.We evaluated anti-HIV antibody profiles using luciferase immunoprecipitation systems (LIPS assay in relation to several blood-based HIV reservoir measures: total and 2-LTR DNA (rtPCR or droplet digital PCR; integrated DNA (Alu PCR; unspliced RNA (rtPCR, multiply-spliced RNA (TILDA, residual plasma HIV RNA (single copy PCR, and replication-competent virus (outgrowth assay. We also assessed total HIV DNA and RNA in gut-associated lymphoid tissue (rtPCR. Spearman correlations and linear regressions were performed using log-transformed blood- or tissue-based reservoir measurements as predictors and log-transformed antibody levels as outcome variables.Among 51 chronically HIV-infected ART-suppressed participants (median age = 57, nadir CD4+ count = 196 cells/mm3, ART duration = 9 years, the most statistically significant associations were between antibody responses to integrase and HIV RNA in gut-associated lymphoid tissue (1.17 fold-increase per two-fold RNA increase, P = 0.004 and between antibody responses to matrix and integrated HIV DNA in resting CD4+ T cells (0.35 fold-decrease per two-fold DNA increase, P = 0.003. However, these associations were not statistically significant after a stringent Bonferroni-adjustment of P<0.00045. Multivariate models including age and duration of ART did not markedly alter results.Our findings suggest that anti-HIV antibody responses may reflect the size of the HIV reservoir during chronic treated HIV disease, possibly via antigen recognition in reservoir sites. Larger, prospective studies are needed to validate the utility of antibody levels as a measure of the total body burden of HIV during treatment.

  2. Naturally occurring anti-glycan antibodies binding to Globo H-expressing cells identify ovarian cancer patients.

    Science.gov (United States)

    Pochechueva, Tatiana; Alam, Shahidul; Schötzau, Andreas; Chinarev, Alexander; Bovin, Nicolai V; Hacker, Neville F; Jacob, Francis; Heinzelmann-Schwarz, Viola

    2017-02-10

    Glycosphingolipids are important compounds of the plasma membrane of mammalian cells and a number of them have been associated with malignant transformation and progression, reinforcing tumour aggressiveness and metastasis. Here we investigated the levels of naturally occurring anti-glycan antibodies to Globo H in blood plasma obtained from high-grade serous ovarian cancer patients (SOC) and women without gynaecological malignancies (control) using suspension glycan array technology employing chemically synthesized glycans as antibody targets. We found that anti-human Globo H IgG antibodies were able to significantly discriminate SOC from controls (P anti-Globo H antibodies highly correlated (r = 0.992). The incubation of plasma-derived anti-glycan antibodies with chemically synthesized (presented on fluorescence microspheres) and native Globo H (expressed on Globo H-positive cell lines) revealed strong reactivity of naturally occurring human anti-Globo H antibodies towards its antigen expressed on ovarian cancer cells. Our data demonstrate that human plasma-derived antibodies to Globo H as well as the presence of the antigen might be considered as therapeutic option in ovarian cancer.

  3. Dengue-Immune Humans Have Higher Levels of Complement-Independent Enhancing Antibody than Complement-Dependent Neutralizing Antibody.

    Science.gov (United States)

    Yamanaka, Atsushi; Konishi, Eiji

    2017-09-25

    Dengue is the most important arboviral disease worldwide. We previously reported that most inhabitants of dengue-endemic countries who are naturally immune to the disease have infection-enhancing antibodies whose in vitro activity does not decrease in the presence of complement (complement-independent enhancing antibodies, or CiEAb). Here, we compared levels of CiEAb and complement-dependent neutralizing antibodies (CdNAb) in dengue-immune humans. A typical antibody dose-response pattern obtained in our assay system to measure the balance between neutralizing and enhancing antibodies showed both neutralizing and enhancing activities depending on serum dilution factor. The addition of complement to the assay system increased the activity of neutralizing antibodies at lower dilutions, indicating the presence of CdNAb. In contrast, similar dose-response curves were obtained with and without complement at higher dilutions, indicating higher levels of CiEAb than CdNAb. For experimental support for the higher CiEAb levels, a cocktail of mouse monoclonal antibodies against dengue virus type 1 was prepared. The antibody dose-response curves obtained in this assay, with or without complement, were similar to those obtained with human serum samples when a high proportion of D1-V-3H12 (an antibody exhibiting only enhancing activity and thus a model for CiEAb) was used in the cocktail. This study revealed higher-level induction of CiEAb than CdNAb in humans naturally infected with dengue viruses.

  4. In vivo neutralization of hepatitis B virus infection by an anti-preS1 humanized antibody in chimpanzees

    International Nuclear Information System (INIS)

    Hong, Hyo Jeong; Ryu, Chun Jeih; Hur, Hyangsuk; Kim, Seho; Oh, Han Kyu; Oh, Mee Sook; Park, Song Yong

    2004-01-01

    Previously, we generated a murine monoclonal antibody (mAb), KR127, that recognizes amino acids (aa) 37-45 of the preS1 of hepatitis B virus (HBV). In this study, we have constructed a humanized version of KR127 and evaluated its HBV-neutralizing activity in chimpanzees. A study chimpanzee was given a single intravenous dose of the humanized antibody, followed by intravenous challenge with adr subtype of wild type HBV, while a control chimpanzee was only challenged with the virus. The result showed that the study chimpanzee did not develop HBV infection during 1 year, while the control chimpanzee was infected, indicating that the humanized antibody exhibited in vivo virus-neutralizing activity and thus protected the chimpanzee from HBV infection. In addition, the humanized antibody bound to the preS1 of all subtypes of HBV. We first demonstrate that an anti-preS1 mAb can neutralize HBV infection in vivo. This humanized antibody will be useful for the immunoprophylaxis of HBV infection

  5. Structure of Simian Immunodeficiency Virus Envelope Spikes Bound with CD4 and Monoclonal Antibody 36D5.

    Science.gov (United States)

    Hu, Guiqing; Liu, Jun; Roux, Kenneth H; Taylor, Kenneth A

    2017-08-15

    The human immunodeficiency virus type 1 (HIV-1)/simian immunodeficiency virus (SIV) envelope spike (Env) mediates viral entry into host cells. The V3 loop of the gp120 component of the Env trimer contributes to the coreceptor binding site and is a target for neutralizing antibodies. We used cryo-electron tomography to visualize the binding of CD4 and the V3 loop monoclonal antibody (MAb) 36D5 to gp120 of the SIV Env trimer. Our results show that 36D5 binds gp120 at the base of the V3 loop and suggest that the antibody exerts its neutralization effect by blocking the coreceptor binding site. The antibody does this without altering the dynamics of the spike motion between closed and open states when CD4 is bound. The interaction between 36D5 and SIV gp120 is similar to the interaction between some broadly neutralizing anti-V3 loop antibodies and HIV-1 gp120. Two conformations of gp120 bound with CD4 are revealed, suggesting an intrinsic dynamic nature of the liganded Env trimer. CD4 binding substantially increases the binding of 36D5 to gp120 in the intact Env trimer, consistent with CD4-induced changes in the conformation of gp120 and the antibody binding site. Binding by MAb 36D5 does not substantially alter the proportions of the two CD4-bound conformations. The position of MAb 36D5 at the V3 base changes little between conformations, indicating that the V3 base serves as a pivot point during the transition between these two states. IMPORTANCE Glycoprotein spikes on the surfaces of SIV and HIV are the sole targets available to the immune system for antibody neutralization. Spikes evade the immune system by a combination of a thick layer of polysaccharide on the surface (the glycan shield) and movement between spike domains that masks the epitope conformation. Using SIV virions whose spikes were "decorated" with the primary cellular receptor (CD4) and an antibody (36D5) at part of the coreceptor binding site, we visualized multiple conformations trapped by the

  6. Radioimmunotherapy of indolent non-Hodgkin's lymphoma with Yttrium-90 labeled anti-CD20 monoclonal antibody therapy does not preclude subsequent chemotherapy or autologous hematologic stem cell transplantation therapy in most patients

    International Nuclear Information System (INIS)

    Wiseman, G.A.; Witzig, T.E.; Ansell, S.M.; Ristow, K.M.

    2002-01-01

    Introduction: Yttrium-90 (Y-90) labeled anti-CD20 monoclonal antibody (ibritumomab tiuxetan or Zevalin TM ) is a novel therapy for patients with relapsed CD20+ B-cell non-Hodgkin's lymphoma (NHL). Patients treated with Zevalin radioimmunotherapy (RIT) are limited from higher doses due to transient and reversible platelet and neutrophil suppression. Patients with indolent NHL who relapse or are refractory to chemotherapy have a 70-80% overall response rate and a 20-30% complete response rate when treated with Zevalin RIT. Therefore additional treatment is required in a minority of patients shortly after Zevalin therapy and in many others at relapse. Relapsed patients are generally treated with chemotherapy alone or high dose chemotherapy followed by autologous transplantation. We wanted to evaluate the ability of patients to tolerate subsequent therapy given at relapse following Zevalin RIT. Methods: We had 58 patients who relapsed after receiving Zevalin RIT and later received additional therapy. The clinical records and lab results were reviewed and compared with a matched control group of patients treated prior to Zevalin availability who received chemotherapy without prior Zevalin RIT. Results: The toxicity in 58 patients treated with Zevalin RIT and subsequent therapy was not significantly different from the control group who did not receive Zevalin RIT. Patients had a median of two subsequent therapies (range, 1-7) after Zevalin. Twenty eight percent required blood cell growth factor support with subsequent chemotherapy and 2 patients required reductions from the standard chemotherapy doses due to prolonged myelosuppression. Eight patients subsequently had successful autologous hematologic stem cell transplant with cells collected after Zevalin. Thirteen of the 58 patients (28%) treated with standard dose chemotherapy were hospitalized for neutropenic fever or thrombocytopenia. Conclusions: Chemotherapy or high dose chemotherapy with autologous transplantation

  7. Mouse monoclonal antibodies against human c-Mpl and characterization for flow cytometry applications.

    Science.gov (United States)

    Abbott, Christina; Huang, Guo; Ellison, Aaron R; Chen, Ching; Arora, Taruna; Szilvassy, Stephen J; Wei, Ping

    2010-04-01

    Mouse monoclonal antibodies (MAbs) against human c-Mpl, the cognate receptor for thrombopoietin (TPO), were generated using hybridoma technology and characterized by various assays to demonstrate their specificity and affinity. Two such MAbs, 1.6 and 1.75, were determined to be superior for flow cytometry studies and exhibited double-digit picomolar (pM) affinities to soluble human c-Mpl protein. Both MAbs specifically bound to cells engineered to overexpress human c-Mpl protein, immortalized human hematopoietic cell lines that express endogenous c-Mpl, primary human bone marrow and peripheral blood-derived CD34(+) cells, and purified human platelets. No binding was detected on cell lines that did not express c-Mpl. Receptor competition and siRNA knock-down studies further confirmed the specificity of antibodies 1.6 and 1.75 for human c-Mpl. In contrast to these newly generated MAbs, none of eight commercially available anti-c-Mpl antibodies tested were found to bind specifically to human c-Mpl and were thus shown to be unsuitable for flow cytometry studies. Monoclonal antibodies 1.6 and 1.75 will therefore be useful flow cytometry reagents to detect cell surface c-Mpl expression.

  8. Efficacy and tolerability of gemtuzumab ozogamicin (anti-CD33 monoclonal antibody, CMA-676, Mylotarg® in children with relapsed/refractory myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Bertrand Yves

    2006-06-01

    Full Text Available Abstract Background Gemtuzumab ozogamicin (GO is a cytotoxic anti-CD33 monoclonal antibody that has given promising preliminary results in adult myeloid CD33+ AML. We conducted a retrospective multicenter study of 12 children treated with GO on a compassionate basis (median age 5.5 y. Three patients (2 MDS/AML, 1 JMML were refractory to first-line treatment, 8 patients with de novo AML were in refractory first relapse, and one patient with de novo AML was in 2nd relapse after stem cell transplantation (SCT. CD33 expression exceeded 20% in all cases. Methods GO was administered alone, at a unit dose of 3–9 mg/m2, once (3 patients, twice (3 patients, three (5 patients or five times (1 patient. Mean follow-up was 128 days (8–585 d. Results There were three complete responses (25% leading to further curative treatment (SCT. Treatment failed in the other nine patients, and only one patient was alive at the end of follow-up. NCI-CTC grade III/IV adverse events comprised hematological toxicity (n = 12, hypertransaminasemia (n = 2, allergy and hyperbilirubinemia (1 case each. There was only one major adverse event (grade IV allergy. No case of sinusoidal obstruction syndrome occurred. Conclusion These results warrant a prospective trial of GO in a larger population of children with AML.

  9. Autoimmune encephalitis with anti-leucine-rich glioma-inactivated 1 or anti-contactin-associated protein-like 2 antibodies (formerly called voltage-gated potassium channel-complex antibodies).

    Science.gov (United States)

    Bastiaansen, Anna E M; van Sonderen, Agnes; Titulaer, Maarten J

    2017-06-01

    Twenty years since the discovery of voltage-gated potassium channel (VGKC)-related autoimmunity; it is currently known that the antibodies are not directed at the VGKC itself but to two closely associated proteins, anti-leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (Caspr2). Antibodies to LGI1 and Caspr2 give well-described clinical phenotypes. Anti-LGI1 encephalitis patients mostly have limbic symptoms, and anti-Caspr2 patients have variable syndromes with both central and peripheral symptoms. A large group of patients with heterogeneous symptoms are VGKC positive but do not have antibodies against LGI1 or Caspr2. The clinical relevance of VGKC positivity in these 'double-negative' patients is questionable. This review focusses on these three essentially different subgroups. The clinical phenotypes of anti-LGI1 encephalitis and anti-Caspr2 encephalitis have been described in more detail including data on treatment and long-term follow-up. A specific human leukocyte antigen (HLA) association was found in nontumor anti-LGI1 encephalitis, but not clearly in those with tumors. There has been increasing interest in the VGKC patients without LGI1/Caspr2 antibodies questioning its relevance in clinical practice. Anti-LGI1 encephalitis and anti-Caspr2 encephalitis are separate clinical entities. Early recognition and treatment is necessary and rewarding. The term VGKC-complex antibodies, lumping patients with anti-LGI1, anti-Caspr2 antibodies or lacking both, should be considered obsolete.

  10. Development of a new high-affinity human antibody with antitumor activity against solid and blood malignancies.

    Science.gov (United States)

    Sioud, Mouldy; Westby, Phuong; Vasovic, Vlada; Fløisand, Yngvar; Peng, Qian

    2018-04-16

    mAbs have emerged as a promising strategy for the treatment of cancer. However, in several malignancies, no effective antitumor mAbs are yet available. Identifying therapeutic mAbs that recognize common tumor antigens could render the treatment widely applicable. Here, a human single-chain variable fragment (scFv) antibody library was sequentially affinity selected against a panel of human cancer cell lines and an antibody fragment (named MS5) that bound to solid and blood cancer cells was identified. The MS5 scFv was fused to the human IgG1 Fc domain to generate an antibody (MS5-Fc fusion) that induced antibody-dependent cellular cytotoxicity and phagocytosis of cancer cells by macrophages. In addition, the MS5-Fc antibody bound to primary leukemia cells and induced antibody-dependent cellular cytotoxicity. In the majority of analyzed cancer cells, the MS5-Fc antibody induced cell surface redistribution of the receptor complexes, but not internalization, thus maximizing the accessibility of the IgG1 Fc domain to immune effector cells. In vitro stability studies showed that the MS5-Fc antibody was stable after 6 d of incubation in human serum, retaining ∼60% of its initial intact form. After intravenous injections, the antibody localized into tumor tissues and inhibited the growth of 3 different human tumor xenografts (breast, lymphoma, and leukemia). These antitumor effects were associated with tumor infiltration by macrophages and NK cells. In the Ramos B-cell lymphoma xenograft model, the MS5-Fc antibody exhibited a comparable antitumor effect as rituximab, a chimeric anti-CD20 IgG1 mAb. These results indicate that human antibodies with pan-cancer abilities can be generated from phage display libraries, and that the engineered MS5-Fc antibody could be an attractive agent for further clinical investigation.-Sioud, M., Westby, P., Vasovic, V., Fløisand, Y., Peng, Q. Development of a new high-affinity human antibody with antitumor activity against solid and

  11. Pathogenic and Epiphenomenal Anti-DNA Antibodies in SLE

    Directory of Open Access Journals (Sweden)

    Mirjana Pavlovic

    2010-01-01

    Full Text Available The discoveries of natural and the development of manufactured highly efficient catalytic antibodies (abzymes opens the door to many practical applications. One of the most fascinating is the use of such antibodies in human therapy and prevention (vaccination, of cancer, AIDS, autoimmune diseases. A special entity of naturally occurring DNA hydrolytic anti-DNA antibodies is emerging within past decades linked to autoimmune and lymphoproliferative disorders, such as systemic lupus erythematosus (SLE, multiple sclerosis (MS, Sjogren Syndrome (SS, B - Chronic lymphocytic leucosis (B-CLL, and Multiple Myeloma (MM. The origin of the antibodies is unknown. The underlying mechanisms of these activities are suggested to be penetration into the living cells and translocation in the nucleus, with recognition of the specific binding sites at particular (ss or ds DNA. There are controversies in the literature whether hydrolysis is a sequence-specific event. The interplay between anti-DNA antibodies and DNA is not yet elucidated. This molecular “twist” also suggests that anti-DNA antibodies with DNA hydrolytic capacity could be the organism's immune response to a microbial attack, with microbial DNA, or specific genes within microbial DNA sequence, as a target for neutralization. The catalytic antibody-based approach can become a key tool in selective chemotherapeutic strategies.

  12. Human monoclonal antibodies reactive with human myelomonocytic leukemia cells.

    Science.gov (United States)

    Posner, M R; Santos, D J; Elboim, H S; Tumber, M B; Frackelton, A R

    1989-04-01

    Peripheral blood mononuclear cells from a patient with chronic myelogenous leukemia (CML), in remission, were depleted of CD8-positive T-cells and cultured with Epstein-Barr virus. Four of 20 cultures (20%) secreted human IgG antibodies selectively reactive with the cell surfaces of certain human leukemia cell lines. Three polyclonal, Epstein-Barr virus-transformed, B-cell lines were expanded and fused with the human-mouse myeloma analogue HMMA2.11TG/O. Antibody from secreting clones HL 1.2 (IgG1), HL 2.1 (IgG3), and HL 3.1 (IgG1) have been characterized. All three react with HL-60 (promyelocytic), RWLeu4 (CML promyelocytic), and U937 (monocytic), but not with KG-1 (myeloblastic) or K562 (CML erythroid). There is no reactivity with T-cell lines, Burkitt's cell lines, pre-B-leukemia cell lines, or an undifferentiated CML cell line, BV173. Leukemic cells from two of seven patients with acute myelogenous leukemia and one of five with acute lymphocytic leukemia react with all three antibodies. Normal lymphocytes, monocytes, polymorphonuclear cells, red blood cells, bone marrow cells, and platelets do not react. Samples from patients with other diverse hematopoietic malignancies showed no reactivity. Immunoprecipitations suggest that the reactive antigen(s) is a lactoperoxidase iodinatable series of cell surface proteins with molecular weights of 42,000-54,000 and a noniodinatable protein with a molecular weight of 82,000. Based on these data these human monoclonal antibodies appear to react with myelomonocytic leukemic cells and may detect a leukemia-specific antigen or a highly restricted differentiation antigen.

  13. Comparison of printed glycan array, suspension array and ELISA in the detection of human anti-glycan antibodies.

    Science.gov (United States)

    Pochechueva, Tatiana; Jacob, Francis; Goldstein, Darlene R; Huflejt, Margaret E; Chinarev, Alexander; Caduff, Rosemarie; Fink, Daniel; Hacker, Neville; Bovin, Nicolai V; Heinzelmann-Schwarz, Viola

    2011-12-01

    Anti-glycan antibodies represent a vast and yet insufficiently investigated subpopulation of naturally occurring and adaptive antibodies in humans. Recently, a variety of glycan-based microarrays emerged, allowing high-throughput profiling of a large repertoire of antibodies. As there are no direct approaches for comparison and evaluation of multi-glycan assays we compared three glycan-based immunoassays, namely printed glycan array (PGA), fluorescent microsphere-based suspension array (SA) and ELISA for their efficacy and selectivity in profiling anti-glycan antibodies in a cohort of 48 patients with and without ovarian cancer. The ABO blood group glycan antigens were selected as well recognized ligands for sensitivity and specificity assessments. As another ligand we selected P(1), a member of the P blood group system recently identified by PGA as a potential ovarian cancer biomarker. All three glyco-immunoassays reflected the known ABO blood groups with high performance. In contrast, anti-P(1) antibody binding profiles displayed much lower concordance. Whilst anti-P(1) antibody levels between benign controls and ovarian cancer patients were significantly discriminated using PGA (p=0.004), we got only similar results using SA (p=0.03) but not for ELISA. Our findings demonstrate that whilst assays were largely positively correlated, each presents unique characteristic features and should be validated by an independent patient cohort rather than another array technique. The variety between methods presumably reflects the differences in glycan presentation and the antigen/antibody ratio, assay conditions and detection technique. This indicates that the glycan-antibody interaction of interest has to guide the assay selection. © The Author(s) 2011. This article is published with open access at Springerlink.com

  14. Enavatuzumab, a Humanized Anti-TWEAK Receptor Monoclonal Antibody, Exerts Antitumor Activity through Attracting and Activating Innate Immune Effector Cells

    Directory of Open Access Journals (Sweden)

    Shiming Ye

    2017-01-01

    Full Text Available Enavatuzumab is a humanized IgG1 anti-TWEAK receptor monoclonal antibody that was evaluated in a phase I clinical study for the treatment of solid malignancies. The current study was to determine whether and how myeloid effector cells were involved in postulated mechanisms for its potent antitumor activity in xenograft models. The initial evidence for a role of effector cells was obtained in a subset of tumor xenograft mouse models whose response to enavatuzumab relied on the binding of Fc of the antibody to Fcγ receptor. The involvement of effector cells was further confirmed by immunohistochemistry, which revealed strong infiltration of CD45+ effector cells into tumor xenografts in responding models, but minimal infiltration in nonresponders. Consistent with the xenograft studies, human effector cells preferentially migrated toward in vivo-responsive tumor cells treated by enavatuzumab in vitro, with the majority of migratory cells being monocytes. Conditioned media from enavatuzumab-treated tumor cells contained elevated levels of chemokines, which might be responsible for enavatuzumab-triggered effector cell migration. These preclinical studies demonstrate that enavatuzumab can exert its potent antitumor activity by actively recruiting and activating myeloid effectors to kill tumor cells. Enavatuzumab-induced chemokines warrant further evaluation in clinical studies as potential biomarkers for such activity.

  15. Molecular imaging of rheumatoid arthritis by radiolabelled monoclonal antibodies: new imaging strategies to guide molecular therapies

    Energy Technology Data Exchange (ETDEWEB)

    Malviya, G.; Dierckx, R.A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen (Netherlands); Conti, F. [Rheumatology Unit, I Faculty of Medicine and Surgery, Sapienza University of Rome (Italy); Chianelli, M. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen (Netherlands); Unit of Nuclear Medicine, Regina apostolorum Hospital, Albano, Rome (Italy); Scopinaro, F. [Nuclear Medicine Department, Sapienza University of Rome, St. Andrea Hospital, Rome (Italy); Signore, A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen (Netherlands); Nuclear Medicine Department, Sapienza University of Rome, St. Andrea Hospital, Rome (Italy)

    2010-02-15

    The closing of the last century opened a wide variety of approaches for inflammation imaging and treatment of patients with rheumatoid arthritis (RA). The introduction of biological therapies for the management of RA started a revolution in the therapeutic armamentarium with the development of several novel monoclonal antibodies (mAbs), which can be murine, chimeric, humanised and fully human antibodies. Monoclonal antibodies specifically bind to their target, which could be adhesion molecules, activation markers, antigens or receptors, to interfere with specific inflammation pathways at the molecular level, leading to immune-modulation of the underlying pathogenic process. These new generation of mAbs can also be radiolabelled by using direct or indirect method, with a variety of nuclides, depending upon the specific diagnostic application. For studying rheumatoid arthritis patients, several monoclonal antibodies and their fragments, including anti-TNF-{alpha}, anti-CD20, anti-CD3, anti-CD4 and anti-E-selectin antibody, have been radiolabelled mainly with {sup 99m}Tc or {sup 111}In. Scintigraphy with these radiolabelled antibodies may offer an exciting possibility for the study of RA patients and holds two types of information: (1) it allows better staging of the disease and diagnosis of the state of activity by early detection of inflamed joints that might be difficult to assess; (2) it might provide a possibility to perform 'evidence-based biological therapy' of arthritis with a view to assessing whether an antibody will localise in an inflamed joint before using the same unlabelled antibody therapeutically. This might prove particularly important for the selection of patients to be treated since biological therapies can be associated with severe side-effects and are considerably expensive. This article reviews the use of radiolabelled mAbs in the study of RA with particular emphasis on the use of different radiolabelled monoclonal antibodies for

  16. Molecular imaging of rheumatoid arthritis by radiolabelled monoclonal antibodies: new imaging strategies to guide molecular therapies

    International Nuclear Information System (INIS)

    Malviya, G.; Dierckx, R.A.; Conti, F.; Chianelli, M.; Scopinaro, F.; Signore, A.

    2010-01-01

    The closing of the last century opened a wide variety of approaches for inflammation imaging and treatment of patients with rheumatoid arthritis (RA). The introduction of biological therapies for the management of RA started a revolution in the therapeutic armamentarium with the development of several novel monoclonal antibodies (mAbs), which can be murine, chimeric, humanised and fully human antibodies. Monoclonal antibodies specifically bind to their target, which could be adhesion molecules, activation markers, antigens or receptors, to interfere with specific inflammation pathways at the molecular level, leading to immune-modulation of the underlying pathogenic process. These new generation of mAbs can also be radiolabelled by using direct or indirect method, with a variety of nuclides, depending upon the specific diagnostic application. For studying rheumatoid arthritis patients, several monoclonal antibodies and their fragments, including anti-TNF-α, anti-CD20, anti-CD3, anti-CD4 and anti-E-selectin antibody, have been radiolabelled mainly with 99m Tc or 111 In. Scintigraphy with these radiolabelled antibodies may offer an exciting possibility for the study of RA patients and holds two types of information: (1) it allows better staging of the disease and diagnosis of the state of activity by early detection of inflamed joints that might be difficult to assess; (2) it might provide a possibility to perform 'evidence-based biological therapy' of arthritis with a view to assessing whether an antibody will localise in an inflamed joint before using the same unlabelled antibody therapeutically. This might prove particularly important for the selection of patients to be treated since biological therapies can be associated with severe side-effects and are considerably expensive. This article reviews the use of radiolabelled mAbs in the study of RA with particular emphasis on the use of different radiolabelled monoclonal antibodies for therapy decision-making and

  17. Detection of serum anti-sperm antibody in infertile couples with dot-immunogold filtration assay (DIGFA)

    International Nuclear Information System (INIS)

    Xie Xiaoxian

    2005-01-01

    Objective: To develop a new method for rapid detection of serum anti-sperm antibody in infertile couples. Methods: Human sperm antigen was prepared from pooled semen specimens of fertile males. Nitro-cellulose membrane was used as solid-phase carrier of the antigen. Colloidal gold pellet combined goat anti-human IgG was taken as labelled antibody. A dot-immunogold filtration assay system was established for test of serum anti-human sperm antibody. Serum specimens from 137 infertile couples were tested and the result compared with flat from ELISA. Results: The human sperm antigen would react with the anti-sperm antibody in the tested serum over the cellulose membrane through filtration and the result could be read with naked eye within 6 minutes. In this study of 137 infertile coupled, the anti-sperm antibody was positive in 21.9% of the female serum specimens and 13.19% of the males. Compared with the result from ELISA, the consistency rate was 96.1%. The sensitivity of the assay was 90.2% and specificity was 95.4%. The p reparation was stable after 6 months refrigerator storage. Conclusion: This newly developed DIGFA is very adequate for rap id detection of anti-sperm antibody and deserves popularization. (authors)

  18. Ovarian carcinoma glyco-antigen targeted by human IgM antibody.

    Directory of Open Access Journals (Sweden)

    Yi Chen

    Full Text Available Epithelial Ovarian Cancer (EOC cells expression of a novel carbohydrate antigen was defined using a human VH4-34 encoded IgM monoclonal antibody (mAb216. MAb216 binds to a poly N-acetyllactosamine epitope expressed on B cells and kills normal and malignant B cells in vitro and in vivo. EOC patient ascites and EOC cell lines were used to study the anti tumor effect of mAb216. Various assays were used to characterize the epitope and demonstrate antibody-mediated binding and cytotoxicity in EOC. Drug and antibody combination effects were determined by calculating the combination index values using the Chou and Talalay method. MAb216 displays direct antibody mediated cytotoxicity on a population of human EOC tumor and ascites samples and EOC cell lines, which express high amounts of poly N-acetyllactosamine epitope, carried by CD147/CD98. Eighty four percent of patient samples, including platin resistant, had a tumor population that bound the monoclonal antibody. The binding pattern of mAb216 and mechanism of cytotoxicity was similar to that seen on normal and malignant B cells with unique general membrane disruption and "pore" formation. In vitro incubation with mAb216 and cisplatin enhanced killing of OVCAR3 cell line. In EOC cell lines percent cytotoxicity correlated with percent expression of epitope. Although in vitro data shows specific EOC cytotoxicity, for possible treatment of EOC MAb216 would need to be evaluated in a clinical trial with or without chemotherapy.

  19. Monoclonal anti-melanoma antibodies and their possible clinical use

    International Nuclear Information System (INIS)

    Hellstroem, K.E.; Hellstroem, Ingegerd; Washington Univ., Seattle; Washington Univ., Seattle

    1985-01-01

    Cell surface antigens of human melanoma, as defined by monoclonal antibodies, are discussed and in particular the three antigens p97, a GD3 ganglioside and a proteoglycan. The potential diagnostic uses of antibodies to melanoma antigens are reviewed including in vitro diagnosis by immuno-histology, in vitro diagnosis by serum assays and in vivo diagnosis by tumour imaging using radioactively labelled antibodies. The potential therapeutic uses of monoclonal antibodies to melanoma antigens are also reviewed including targets for antibody therapy, the use of antibodies alone, radiolabelled antibodies, antibody-toxin conjugates, antibody-drug conjugates, anti-idiotypic antibodies and vaccines. (UK)

  20. Fluorescently labeled chimeric anti-CEA antibody improves detection and resection of human colon cancer in a patient-derived orthotopic xenograft (PDOX) nude mouse model.

    Science.gov (United States)

    Metildi, Cristina A; Kaushal, Sharmeela; Luiken, George A; Talamini, Mark A; Hoffman, Robert M; Bouvet, Michael

    2014-04-01

    The aim of this study was to evaluate a new fluorescently labeled chimeric anti-CEA antibody for improved detection and resection of colon cancer. Frozen tumor and normal human tissue samples were stained with chimeric and mouse antibody-fluorophore conjugates for comparison. Mice with patient-derived orthotopic xenografts (PDOX) of colon cancer underwent fluorescence-guided surgery (FGS) or bright-light surgery (BLS) 24 hr after tail vein injection of fluorophore-conjugated chimeric anti-CEA antibody. Resection completeness was assessed using postoperative images. Mice were followed for 6 months for recurrence. The fluorophore conjugation efficiency (dye/mole ratio) improved from 3-4 to >5.5 with the chimeric CEA antibody compared to mouse anti-CEA antibody. CEA-expressing tumors labeled with chimeric CEA antibody provided a brighter fluorescence signal on frozen human tumor tissues (P = 0.046) and demonstrated consistently lower fluorescence signals in normal human tissues compared to mouse antibody. Chimeric CEA antibody accurately labeled PDOX colon cancer in nude mice, enabling improved detection of tumor margins for more effective FGS. The R0 resection rate increased from 86% to 96% with FGS compared to BLS. Improved conjugating efficiency and labeling with chimeric fluorophore-conjugated antibody resulted in better detection and resection of human colon cancer in an orthotopic mouse model. © 2013 Wiley Periodicals, Inc.

  1. Anti-tau antibody administration increases plasma tau in transgenic mice and patients with tauopathy

    Science.gov (United States)

    Yanamandra, Kiran; Patel, Tirth K.; Jiang, Hong; Schindler, Suzanne; Ulrich, Jason D.; Boxer, Adam L.; Miller, Bruce L.; Kerwin, Diana R.; Gallardo, Gilbert; Stewart, Floy; Finn, Mary Beth; Cairns, Nigel J.; Verghese, Philip B.; Fogelman, Ilana; West, Tim; Braunstein, Joel; Robinson, Grace; Keyser, Jennifer; Roh, Joseph; Knapik, Stephanie S.; Hu, Yan; Holtzman, David M.

    2017-01-01

    Tauopathies are a group of disorders in which the cytosolic protein tau aggregates and accumulates in cells within the brain, resulting in neurodegeneration. A promising treatment being explored for tauopathies is passive immunization with anti-tau antibodies. We previously found that administration of an anti-tau antibody to human tau transgenic mice increased the concentration of plasma tau. We further explored the effects of administering an anti-tau antibody on plasma tau. After peripheral administration of an anti-tau antibody to human patients with tauopathy and to mice expressing human tau in the central nervous system, there was a dose-dependent increase in plasma tau. In mouse plasma, we found that tau had a short half-life of 8 min that increased to more than 3 hours after administration of anti-tau antibody. As tau transgenic mice accumulated insoluble tau in the brain, brain soluble and interstitial fluid tau decreased. Administration of anti-tau antibody to tau transgenic mice that had decreased brain soluble tau and interstitial fluid tau resulted in an increase in plasma tau, but this increase was less than that observed in tau transgenic mice without these brain changes. Tau transgenic mice subjected to acute neuronal injury using 3-nitropropionic acid showed increased interstitial fluid tau and plasma tau. These data suggest that peripheral administration of an anti-tau antibody results in increased plasma tau, which correlates with the concentration of extracellular and soluble tau in the brain. PMID:28424326

  2. 131I-Anti-CD45 Antibody Plus Busulfan and Cyclophosphamide before Allogeneic Hematophoietic Cell Transplantation for Treatment of Acute Myeloid Leukemia in First Remission

    International Nuclear Information System (INIS)

    Pagel, John M.; Appelbaum, Frederick R.; Eary, Janet F.; Rajendran, Joseph G.; Fisher, Darrell R.; Gooley, Ted; Ruffner, Katherine; Nemecek, Eneida; Sickle, Eileen; Durack, Larry; Carreras, Jeanette; Horowitz, Mary; Press, Oliver W.; Gopal, Ajay K.; Martin, Paul J.; Bernstein, Irwin D.; Matthews, Dana C.

    2006-01-01

    In an attempt to improve outcomes for patients with acute myeloid leukemia (AML) after allogeneic hematopoietic cell transplantation (HCT), we conducted a Phase I/II study in which targeted irradiation delivered by 131I-anti-CD45 antibody was combined with targeted busulfan (BU; area-under-curve, 600-900 ng/ml) and cyclophosphamide (CY; 120 mg/kg). Fifty-two of 59 patients (88%) receiving a trace 131I-labeled dose of 0.5 mg/kg anti-CD45 murine antibody had higher estimated absorbed radiation in bone marrow and spleen than in any other organ. Forty-six patients were treated with 102-298 mCi 131I delivering an estimated 5.3-19 (mean 11.3) Gy to marrow, 17-72 (mean 29.7) Gy to spleen, and 3.5 Gy (n=4) to 5.25 Gy (n=42) to the liver. The estimated 3-year non-relapse mortality and disease-free survival (DFS) were 21% and 61%, respectively. These results were compared to those from 509 similar International Bone Marrow Transplant Registry patients transplanted using BU/CY alone. After adjusting for differences in age and cytogenetics-risk, the hazard of mortality among all antibody-treated patients was 0.65 times that of the Registry patients (95% CI 0.39-1.08; p=.09). The addition of targeted hematopoietic irradiation to conventional BU/CY is feasible and well tolerated, and Phase II results are sufficiently encouraging to warrant further study

  3. A Single Domain–Based Anti-Her2 Antibody Has Potent Antitumor Activities

    Directory of Open Access Journals (Sweden)

    Xiaoqiong Wu

    2018-04-01

    Full Text Available Human epidermal growth factor receptor 2 (HER2 is overexpressed in approximately 20% to 30% of breast cancers and various other types of cancers, which plays a vital role in the cancer progression. Monoclonal antibodies targeting Her2 are now used in the clinic to treat Her2 overexpression cancer patients. However, relapse or resistance is frequent with the current therapies. To generate a new treatment avenue against Her2, we immunized and selected a specific anti-Her2 single domain antibody C3 for further studies. The C3-Fc antibody drove antibody-dependent cell-mediated cytotoxicity against Her2-positive tumor cells in vitro and resulted in potent antitumor growth in vivo. These data suggest that the C3-Fc antibody may provide an alternative avenue for Her2-positive cancer therapy.

  4. Broad, Intense Anti-Human Immunodeficiency Virus (HIV) Ex Vivo CD8+ Responses in HIV Type 1-Infected Patients: Comparison with Anti-Epstein-Barr Virus Responses and Changes during Antiretroviral Therapy

    Science.gov (United States)

    Dalod, Marc; Dupuis, Marion; Deschemin, Jean-Christophe; Sicard, Didier; Salmon, Dominique; Delfraissy, Jean-Francois; Venet, Alain; Sinet, Martine; Guillet, Jean-Gerard

    1999-01-01

    The ex vivo antiviral CD8+ repertoires of 34 human immunodeficiency virus (HIV)-seropositive patients with various CD4+ T-cell counts and virus loads were analyzed by gamma interferon enzyme-linked immunospot assay, using peptides derived from HIV type 1 and Epstein-Barr virus (EBV). Most patients recognized many HIV peptides, with markedly high frequencies, in association with all the HLA class I molecules tested. We found no correlation between the intensity of anti-HIV CD8+ responses and the CD4+ counts or virus load. In contrast, the polyclonality of anti-HIV CD8+ responses was positively correlated with the CD4+ counts. The anti-EBV responses were significantly less intense than the anti-HIV responses and were positively correlated with the CD4+ counts. Longitudinal follow-up of several patients revealed the remarkable stability of the anti-HIV and anti-EBV CD8+ responses in two patients with stable CD4+ counts, while both antiviral responses decreased in two patients with obvious progression toward disease. Last, highly active antiretroviral therapy induced marked decreases in the number of anti-HIV CD8+ T cells, while the anti-EBV responses increased. These findings emphasize the magnitude of the ex vivo HIV-specific CD8+ responses at all stages of HIV infection and suggest that the CD8+ hyperlymphocytosis commonly observed in HIV infection is driven mainly by virus replication, through intense, continuous activation of HIV-specific CD8+ T cells until ultimate progression toward disease. Nevertheless, highly polyclonal anti-HIV CD8+ responses may be associated with a better clinical status. Our data also suggest that a decrease of anti-EBV CD8+ responses may occur with depletion of CD4+ T cells, but this could be restored by highly active antiretroviral treatment. PMID:10438796

  5. MHC class II ligation induces CD58 (LFA-3)-mediated adhesion in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Gerwien, J; Geisler, C

    1998-01-01

    ligation induces homotypic adhesion in both beta2-integrin-positive and negative, CD4-positive T cell lines. Anti-CD18 monoclonal antibody (mAb) weakly inhibited the adhesion response in beta2-integrin-positive T cells and had no effect on beta2-integrin-negative T cells. In contrast, an anti-CD58 (LFA-3...

  6. Novel Clostridium difficile Anti-Toxin (TcdA and TcdB Humanized Monoclonal Antibodies Demonstrate In Vitro Neutralization across a Broad Spectrum of Clinical Strains and In Vivo Potency in a Hamster Spore Challenge Model.

    Directory of Open Access Journals (Sweden)

    Hongyu Qiu

    Full Text Available Clostridium difficile (C. difficile infection (CDI is the main cause of nosocomial antibiotic-associated colitis and increased incidence of community-associated diarrhea in industrialized countries. At present, the primary treatment of CDI is antibiotic administration, which is effective but often associated with recurrence, especially in the elderly. Pathogenic strains produce enterotoxin, toxin A (TcdA, and cytotoxin, toxin B (TcdB, which are necessary for C. difficile induced diarrhea and gut pathological changes. Administration of anti-toxin antibodies provides an alternative approach to treat CDI, and has shown promising results in preclinical and clinical studies. In the current study, several humanized anti-TcdA and anti-TcdB monoclonal antibodies were generated and their protective potency was characterized in a hamster infection model. The humanized anti-TcdA (CANmAbA4 and anti-TcdB (CANmAbB4 and CANmAbB1 antibodies showed broad spectrum in vitro neutralization of toxins from clinical strains and neutralization in a mouse toxin challenge model. Moreover, co-administration of humanized antibodies (CANmAbA4 and CANmAbB4 cocktail provided a high level of protection in a dose dependent manner (85% versus 57% survival at day 22 for 50 mg/kg and 20 mg/kg doses, respectively in a hamster gastrointestinal infection (GI model. This study describes the protective effects conferred by novel neutralizing anti-toxin monoclonal antibodies against C. difficile toxins and their potential as therapeutic agents in treating CDI.

  7. Chimeric antigen receptor T cells secreting anti-PD-L1 antibodies more effectively regress renal cell carcinoma in a humanized mouse model.

    Science.gov (United States)

    Suarez, Eloah Rabello; Chang, De Kuan; Sun, Jiusong; Sui, Jianhua; Freeman, Gordon J; Signoretti, Sabina; Zhu, Quan; Marasco, Wayne A

    2016-06-07

    Advances in the treatment of metastatic clear cell renal cell carcinoma (ccRCC) have led to improved progression-free survival of many patients; however the therapies are toxic, rarely achieve durable long-term complete responses and are not curative. Herein we used a single bicistronic lentiviral vector to develop a new combination immunotherapy that consists of human anti-carbonic anhydrase IX (CAIX)-targeted chimeric antigen receptor (CAR) T cells engineered to secrete human anti-programmed death ligand 1 (PD-L1) antibodies at the tumor site. The local antibody delivery led to marked immune checkpoint blockade. Tumor growth diminished 5 times and tumor weight reduced 50-80% when compared with the anti-CAIX CAR T cells alone in a humanized mice model of ccRCC. The expression of PD-L1 and Ki67 in the tumors decreased and an increase in granzyme B levels was found in CAR T cells. The anti-PD-L1 IgG1 isotype, which is capable of mediating ADCC, was also able to recruit human NK cells to the tumor site in vivo. These armed second-generation CAR T cells empowered to secrete human anti-PD-L1 antibodies in the ccRCC milieu to combat T cell exhaustion is an innovation in this field that should provide renewed potential for CAR T cell immunotherapy of solid tumors where limited efficacy is currently seen.

  8. Interleukin-9 receptor α chain mRNA formation in CD8+ T cells producing anti-human immunodeficiency virus type 1 substance(s)

    International Nuclear Information System (INIS)

    Hossain, M.M.; Tsuchie, H.; Detorio, M.A.; Shirono, H.; Hara, C.; Nishimoto, A.; Saji, A.; Koga, J.; Takata, N.; Maniar, J.K.; Saple, D.G.; Taniguchi, K.; Kageyama, S.; Ichimura, H.; Kurimura, T.

    1998-01-01

    A search for gene(s) associated with anti-human immunodeficiency virus type 1 (HIV-l) activity of CD8 + T cells was attempted using molecular cloning and the relation between the anti-HIV activity of CD8 + T cells and the interleukin-9 receptor a chain (IL-9R-α) mRNA expression from the cDNA clones obtained was examined. The anti-HIV-l activity of CD8 + T cell culture supernatants was assessed by measuring the level of HIV-l replication in a CD4 + T cell line transfected with an infectious HIV-l DNA clone. IL-9R-a mRNA was assayed by reverse transcriptase-polymerase chain reaction (RT-PCR). Of 5 cases showing high level of anti-HIV-l activity (more than 80% suppression of HIV-l replication), the mRNA was detected in 4 cases. Of 10 cases showing low level of anti-HIV-l activity (less than 80% suppression of HIV-l replication), the mRNA was detected in one case. Soluble recombinant human IL-9 receptor (rhIL-9sR) did not suppress HIV-l replication at a concentration of 1 μg/ml. These data suggest that the IL-9R-a mRNA formation in CD8 + T cells may correlate with and play some role in the anti-HIV-l activity of CD8+ T cells from HIV-l-infected individuals. Key words: CD8+ T cells; anti-HIV-l activity; cytokines; interleukin-9 receptor (authors)

  9. [Cloning of VH and VL Gene of Human anti-IL1RAP McAb and Construction of Recombinant Chimeric Receptor].

    Science.gov (United States)

    Yin, Ling-Ling; Ruan, Su-Hong; Tian, Yu; Zhao, Kai; Xu, Kai Lin

    2015-10-01

    To clone the variable region genes of human anti-IL1RAP (IL-1 receptor accessory protein) monoclonal antibodies (McAb) and to construct IL1RAP chimeric antigen receptors (CARs). The VH and VL DNA of IL1RAP single chain antibodies were amplified by RACE and overlap extension PCR from total RNA extracted from 3H6E10 and 10D8A7 hybridoma and ligated into specific IL1RAP single-chain variable fragments (scFv). CD8α transmembrane domain, CD137 intracellular domain, TCR ζ chain, human CD8α signal peptide and scFv-anti-IL1RAP were cloned into plasmid LV-lac. Recombinant lentiviruses were generated by co-transfection of recombinant plasmid LV-lac, pMD2. G, and psPAX2 helper vectors into 293FT packing cells. The VH and VL genes of 2 human anti-IL1RAP McAb were acquired. The 3H6E10 VH and VL genes consisted of 402 bp and 393 bp encoding 134 and 131 aminoacid residues, respectively; 10D8A7 VH and VL genes consisted of 423 bp and 381 bp encoding 141 and 127 amine acid residues, respectively. Recombinant expression vertors LV-3H6E10 scFv-ICD and LV-10D8A7 scFv-ICD (ICD: CD8α transmembrane domain-CD137 intracellular domain-TCR ζ chain) were constructed. The target fragments were demonstrated by sequencing analysis. Recombinant plasmids were transfected into 293FT cells and lentiviral particles were acquired. Human anti-IL1RAP recombinant receptors are constructed successfully and lay a good foundation for the construction of IL1RAP-CAR killer T cell vaccine.

  10. Characterization of monoclonal antibodies against human thyrotropin and use in an immunoradiometric assay and immunohistochemistry

    International Nuclear Information System (INIS)

    Benkirane, M.; Bon, D.; Bellot, F.; Prince, P.; Delori, P.; Hassoun, J.; Carayon, P.

    1987-01-01

    Monoclonal antibodies were prepared against human thyrotropin. 13 different antibodies were characterized. Ten antibodies were of the IgG1 subclass. The affinities of the antibodies were in the range 10 9 -10 11 mol -1 .l. Four of them were specific for hTSH and did not react with hLH, hFSH, hCG or αhCG. Four reacted with these hormones and recognized the α subunit of hCG. One cross-reacted only with HFSH. The remaining four antibodies recognized the holo-hTSH only, and thus were designated as anti-conformational determinants. Monoclonal antibodies reacting with different antigenic determinants on the hTSH molecule defined seven clusters. Two of them were used to develop a simplified two-site sandwich radioimmunoassay in which one monoclonal antibody was immobilized on tubes (anti-βTSH) and another (anti-α) labelled with 125 I. This assay was highly specific and demonstrated a sensitivity level of 0.1 μIU/ml. Two monoclonal antibodies were used in immunohistochemistry and their quality and specificity was assessed in the detection of hTSH immunoreactivity in human pituitary biological sections. 20 refs.; 6 figs.; 2 tabs

  11. Risk of classical Kaposi sarcoma by plasma levels of Epstein-Barr virus antibodies, sCD26, sCD23 and sCD30

    Directory of Open Access Journals (Sweden)

    Viviano Enza

    2010-10-01

    Full Text Available Abstract Background To clarify the immunological alterations leading to classical Kaposi sarcoma (cKS among people infected with KS-associated herpesvirus (KSHV. Methods In a population-based study of 119 cKS cases, 105 KSHV-seropositive controls, and 155 KSHV-seronegative controls, we quantified plasma soluble cluster of differentiation (sCD levels and antibodies against Epstein-Barr virus nuclear antigen-1 (anti-EBNA-1 and viral capsid antigen (anti-VCA. Differences between groups in prevalence of low-tertile anti-EBNA-1 and high-tertile anti-VCA were compared by logistic regression. Continuous levels between groups and by presence of cKS co-factors among controls were compared by linear regression and Mann-Whitney-Wilcoxon methods. Results Comparisons of cKS cases to seropositive controls and of seropositive to seronegative controls revealed no significant differences. However, controls with known cKS cofactors (male sex, nonsmoking, diabetes and cortisone use had significantly lower levels of anti-EBNA (P = 0.0001 - 0.07 and anti-VCA (P = 0.0001 - 0.03. Levels of sCD26 were significantly lower for male and non-smoking controls (Padj ≤ 0.03, and they were marginally lower with older age and cortisone use (Padj ≤ 0.09. Conclusions Anti-EBV and sCD26 levels were associated with cofactors for cKS, but they did not differ between cKS cases and matched controls. Novel approaches and broader panels of assays are needed to investigate immunological contributions to cKS.

  12. Anti-human neutrophil antigen-1a, -1b, and -2 antibodies in neonates and children with immune neutropenias analyzed by extracted granulocyte antigen immunofluorescence assay.

    Science.gov (United States)

    Onodera, Rie; Kurita, Emi; Taniguchi, Kikuyo; Karakawa, Shuhei; Okada, Satoshi; Kihara, Hirotaka; Fujii, Teruhisa; Kobayashi, Masao

    2017-11-01

    Anti-human neutrophil antigen (HNA) antibodies have been implicated in the development of neonatal alloimmune neutropenia (NAN) and autoimmune neutropenia (AIN). There are many conventional assay methods that detect anti-HNA antibodies. However, a method to measure multiple samples and detect several anti-HNA antibodies simultaneously is needed. We developed a new method, the extracted granulocyte antigen immunofluorescence assay (EGIFA), to analyze anti-HNA-1a, -1b, and -2 antibodies in sera. The results obtained by EGIFA were evaluated in comparison with those from several standard assay methods. Anti-HNA antibodies in serum samples from nine familial cases with suspected NAN (n = 19) and children with suspected AIN (n = 88) were also measured by EGIFA. The evaluation of nine serum samples with anti-HNA antibodies suggested that EGIFA demonstrated equivalent specificity and superior sensitivity to monoclonal antibody-specific immobilization of granulocyte antigens and had comparable sensitivity to the granulocyte indirect immunofluorescence test. EGIFA successfully detected anti-HNA-1a or -1b antibodies in seven of nine familial cases with suspected NAN. EGIFA detected anti-HNA antibodies in 40.9% of children with suspected AIN. Among them, isolated anti-HNA-1a or -1b antibody was detected in 4.5 or 12.5% of children, respectively, and anti-HNA-2 antibody was identified in 3.4% of children. The 30.8% (16 of 52) of children negative for anti-HNA antibody by EGIFA were positive for anti-HLA antibody. EGIFA facilitated the measurement of anti-HNA-1a, -1b, and/or -2 antibodies in sera. The prompt measurement of anti-HNA antibodies will improve the diagnosis and clinical management of patients with suspected NAN or AIN. © 2017 AABB.

  13. Ex vivo generation of human alloantigen-specific regulatory T cells from CD4(posCD25(high T cells for immunotherapy.

    Directory of Open Access Journals (Sweden)

    Jorieke H Peters

    Full Text Available BACKGROUND: Regulatory T cell (Treg based immunotherapy is a potential treatment for several immune disorders. By now, this approach proved successful in preclinical animal transplantation and auto-immunity models. In these models the success of Treg based immunotherapy crucially depends on the antigen-specificity of the infused Treg population. For the human setting, information is lacking on how to generate Treg with direct antigen-specificity ex vivo to be used for immunotherapy. METHODOLOGY/PRINCIPAL FINDINGS: Here, we demonstrate that in as little as two stimulation cycles with HLA mismatched allogeneic stimulator cells and T cell growth factors a very high degree of alloantigen-specificity was reached in magnetic bead isolated human CD4(posCD25(high Treg. Efficient increases in cell numbers were obtained. Primary allogeneic stimulation appeared a prerequisite in the generation of alloantigen-specific Treg, while secondary allogeneic or polyclonal stimulation with anti-CD3 plus anti-CD28 monoclonal antibodies enriched alloantigen-specificity and cell yield to a similar extent. CONCLUSIONS/SIGNIFICANCE: The ex vivo expansion protocol that we describe will very likely increase the success of clinical Treg-based immunotherapy, and will help to induce tolerance to selected antigens, while minimizing general immune suppression. This approach is of particular interest for recipients of HLA mismatched transplants.

  14. Unexplained infertility: identification of anti sperm antibodies using radiometric immunoassay

    International Nuclear Information System (INIS)

    Megahed, Y.M.; Elnabarawy, F.; Hamada, T.; Ayiad, S.K.

    1992-01-01

    Several methods have been employed to measure anti sperm antibodies with variable sensitivity and specificity in serum and secretion of infertile patients. All of them are not precise means for identification of the presence of anti sperm antibodies for patients with unexplained infertility (Haas et al, 1980). Therefore, the modified radiolabelled anti globulin test, that has been used successfully to identify and quantitate the antibodies directed towards other human cell surfaces, was applied. A total number of 128 subjects in different groups were studied to quantitate the circulating anti sperm antibodies using the modified procedure. The present data revealed that the highest and the most significant incidence were found in the patients secretions (semen and cervical mucus) with unexplained infertility, as well as in the group of males with varicocele. Therefore it is greatly advisable to use the modified radiolabelled technique as a quantitative assay, which will be helpful in management of infertility in patients with unexplained and mediated infertility.3 tab., 4 fig

  15. Monoclonal anti-human factor VII antibodies. Detection in plasma of a second protein antigenically and genetically related to factor VII.

    OpenAIRE

    Broze, G J; Hickman, S; Miletich, J P

    1985-01-01

    Several murine monoclonal anti-human Factor VII antibodies were produced using hybridoma technology. Two noncompetitive monoclonal antibodies were used to examine by Western blotting the Factor VII cross-reactive material (CRM) in normal human plasma and three commercially available congenitally Factor VII-deficient plasmas, and to construct a facile "sandwich" immunoassay for plasma Factor VII. A second, previously undescribed, form of Factor VII CRM was detected in human plasma, which on We...

  16. Targeted treatment for chronic lymphocytic leukemia: clinical potential of obinutuzumab

    Directory of Open Access Journals (Sweden)

    Smolej L

    2014-12-01

    Full Text Available Lukáš Smolej 4th Department of Internal Medicine – Hematology, University Hospital Hradec Králové and Charles University in Prague, Faculty of Medicine in Hradec Králové, Hradec Králové, Czech Republic Abstract: Introduction of targeted agents revolutionized the treatment of chronic lymphocytic leukemia (CLL in the past decade. Addition of chimeric monoclonal anti-CD20 antibody rituximab to chemotherapy significantly improved efficacy including overall survival (OS in untreated fit patients; humanized anti-CD52 antibody alemtuzumab and fully human anti-CD20 antibody ofatumumab lead to improvement in refractory disease. Novel small molecule inhibitors such as ibrutinib and idelalisib demonstrated excellent activity and were very recently licensed in relapsed/refractory CLL. Obinutuzumab (GA101 is the newest monoclonal antibody approved for the treatment of CLL. This novel, glycoengineered, type II humanized anti-CD20 antibody is characterized by enhanced antibody-dependent cellular cytotoxicity and direct induction of cell death compared to type I antibodies. Combination of obinutuzumab and chlorambucil yielded significantly better OS in comparison to chlorambucil monotherapy in untreated comorbid patients. These results led to approval of obinuzutumab for the treatment of CLL. Numerous clinical trials combining obinutuzumab with other cytotoxic drugs and novel small molecules are currently under way. This review focuses on the role of obinutuzumab in the treatment of CLL. Keywords: chronic lymphocytic leukemia, anti-CD20 antibodies, chlorambucil, rituximab, ofatumumab, obinutuzumab, overall survival

  17. Antibody reaction of human anti-Toxoplasma gondii positive and negative sera with Neospora caninum antigens

    OpenAIRE

    Nam, Ho-Woo; Kang, Seung-Won; Choi, Won-Young

    1998-01-01

    Anti-Neospora caninum antibody was detected in anti-Toxoplasma gondii positive and negative human sera by ELISA, western blot and immunofluorescence assay (IFA). Twelve cases out of 172 (6.7%) Toxoplasma-positive sera cross-reacted with both T. gondii and N. caninum antigens, and one out of 110 Toxoplasma-negative sera reacted with N. caninum antigen by ELISA. By western blot, all 12 sera reacted with T. gondii antigens with various banding patterns but specifically at 30 kDa (SAG1) and 22 kD...

  18. Synergy of anti-CD40, CpG and MPL in activation of mouse macrophages.

    Science.gov (United States)

    Shi, Yongyu; Felder, Mildred A R; Sondel, Paul M; Rakhmilevich, Alexander L

    2015-08-01

    Activation of macrophages is a prerequisite for their antitumor effects. Several reagents, including agonistic anti-CD40 monoclonal antibody (anti-CD40), CpG oligodeoxynucleotides (CpG) and monophosphoryl lipid A (MPL), can stimulate activation of macrophages. Our previous studies showed synergy between anti-CD40 and CpG and between anti-CD40 and MPL in macrophage activation and antitumor efficacy in mice. In the present study, we asked whether there was synergy among these three reagents. The activation of adherent peritoneal exudate cells (PEC) obtained from mice injected with anti-CD40 and then treated with CpG and/or MPL in vitro was determined by their ability to suppress proliferation of tumor cells and to produce various cytokines and chemokines in vitro. Cell sorting and histology followed by functional testing showed that macrophages were the main cell population in PEC activated by CD40 ligation in vivo. A combination of anti-CD40, CpG or MPL activated PEC to suppress proliferation of B16 cells and produce nitric oxide far greater than the single reagents or any of the double combinations of these reagents. In addition, the combination of all three reagents activated PEC to secrete IL-12, IFN-γ and MCP-1 to a greater degree than any single reagent or any two combined reagents. These results demonstrate that macrophages can be synergistically activated by anti-CD40, CpG and MPL, suggesting that this novel combined approach might be further investigated as potential cancer therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Synergy of anti-CD40, CpG and MPL in activation of mouse macrophages

    Science.gov (United States)

    Shi, Yongyu; Felder, Mildred A.R.; Sondel, Paul M.; Rakhmilevich, Alexander L.

    2015-01-01

    Activation of macrophages is a prerequisite for their antitumor effects. Several reagents, including agonistic anti-CD40 monoclonal antibody (anti-CD40), CpG oligodeoxynucleotides (CpG) and monophosphoryl lipid A (MPL), can stimulate activation of macrophages. Our previous studies showed synergy between anti-CD40 and CpG and between anti-CD40 and MPL in macrophage activation and antitumor efficacy in mice. In the present study, we asked whether there was synergy among these three reagents. The activation of adherent peritoneal exudate cells (PEC) obtained from mice injected with anti-CD40 and then treated with CpG and/or MPL in vitro was determined by their ability to suppress proliferation of tumor cells and to produce various cytokines and chemokines in vitro. Cell sorting and histology followed by functional testing showed that macrophages were the main cell population in PEC activated by CD40 ligation in vivo. A combination of anti-CD40, CpG or MPL activated PEC to suppress proliferation of B16 cells and produce nitric oxide far greater than the single reagents or any of the double combinations of these reagents. In addition, the combination of all three reagents activated PEC to secrete IL-12, IFN-γ and MCP-1 to a greater degree than any single reagent or any two combined reagents. These results demonstrate that macrophages can be synergistically activated by anti-CD40, CpG and MPL, suggesting that this novel combined approach might be further investigated as potential cancer therapy. PMID:25829245

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

    International Nuclear Information System (INIS)

    Elazar, Z.; Kanety, H.; Schreiber, M.; Fuchs, S.

    1988-01-01

    Anti-idiotypic antibodies were raised in rabbits by immunization with a monoclonal anti-haloperidol antibody. Some of these anti-idiotypic antibodies bind in a concentration dependent manner to bovine striatal membranes. Following affinity purification, these antibodies inhibit haloperidol binding to striatal membranes and deplete [ 3 H]-spiperone binding sites from a solubilized preparation of striatal membranes. It is thus concluded that these anti-idiotypic antibodies are an internal image of haloperidol and as such can interact with D 2 -dopamine receptors

  1. The significance of anti-DFS70 antibodies in the diagnosis of autoimmune disorders

    Directory of Open Access Journals (Sweden)

    Barbara Nieradko-Iwanicka

    2017-06-01

    Full Text Available Background . Anti-DFS70 antibodies are a subgroup of antinuclear antibodies (ANA. They are connected with the dense fine speckled autoantigen of 70 kD, known as the lens epithelium-derived growth factor p75. Objectives. The objective of the review is to present the role of anti-DFS70 antibodies in the diagnosis of autoimmune diseases on the basis of recent publications. Material and methods . The authors searched for articles in the Pubmed database using the key words: anti-DFS70 antibodies, systemic autoimmune rheumatic diseases and autoimmune disorders. Results . Anti-DFS70 antibodies can be detected in eye diseases, atopic diseases, alopecia areata, fibromyalgia, asthma, chronic fatigue syndrome, tumors, Hashimoto’s disease, Graves’ disease, Behcet’s disease, inflammatory bowel diseases, neoplasms and in infectious diseases. These antibodies are sometimes detected in patients with ANA-associated rheumatic diseases (AARD . Up to 20% of serum samples from healthy individuals (HI are ANA-positive. This is probably due to the presence of monospecific anti-DFS70 antibodies. Monospecific anti-DFS70 antibodies are not associated with AARD , but mixed anti-DFS70 can be found in AARD . Conclusions . Family physicians usually do not order ANA, extractable nuclear antigens (ENA or anti-DFS70 antibodies, but they should be aware that anti-DFS70 antibodies are biomarkers that can discriminate AARD from non-AARD , save patients from unnecessary, potentially toxic treatment and save finances typically spent on retesting and visits to specialists.

  2. Cetuximab in combination with anti-human IgG antibodies efficiently down-regulates the EGF receptor by macropinocytosis

    International Nuclear Information System (INIS)

    Berger, Christian; Madshus, Inger Helene; Stang, Espen

    2012-01-01

    The monoclonal antibody C225 (Cetuximab) blocks binding of ligand to the epidermal growth factor receptor (EGFR). In addition, it is known that incubation with C225 induces endocytosis of the EGFR. This endocytosis has previously been shown to be increased when C225 is combined with an additional monoclonal anti-EGFR antibody. However, the effects of antibody combinations on EGFR activation, endocytosis, trafficking and degradation have been unclear. By binding a secondary antibody to the C225-EGFR complex, we here demonstrate that a combination of antibodies can efficiently internalize and degrade the EGFR. Although the combination of antibodies activated the EGFR kinase and induced ubiquitination of the EGFR, the kinase activity was not required for internalization of the EGFR. In contrast to EGF-induced EGFR down-regulation, the antibody combination efficiently degraded the EGFR without initiating downstream proliferative signaling. The antibody-induced internalization of EGFR was found not to depend on clathrin and/or dynamin, but depended on actin polymerization, suggesting induction of macropinocytosis. Macropinocytosis may cause internalization of large membrane areas, and this could explain the highly efficient internalization of the EGFR induced by combination of antibodies. -- Highlight: ► Cetuximab induced endocytosis of EGFR increases upon combination with anti-human IgG. ► Antibody combination causes internalization of EGFR by macropinocytosis. ► Antibody-induced internalization of EGFR is independent of EGFR kinase activity. ► Antibody combination may have a zipper effect and cross-link EGFRs on neighboring cells.

  3. Purification of immunoreactive radiolabeled moniclonal antibodies with anti-iodiotypic moniclonal antibodies

    International Nuclear Information System (INIS)

    Temponi, M.; Pupa, S.; Ferrone, S.

    1990-01-01

    A method is described to purify immunoreactive moniclonal antibodies from radiolabeled monoclonal antibody preparations. The method is based on incubation of radiolabeled monoclonal antibodies with insolubilized anti-idiotypic monoclonal antibodies to idiotopes within the antigen-combining site of monoclonal antibodies to be purified an elution of bound monoclonal antibodies with a low pH buffer. The immunoreactive fraction of the purified monoclonal antibodies was at least 82%; the yeald was at least 73%. The purification procedure did not cause any detectable change in the affinity constant of the eluted monoclonal antibodies. The method is simple and rapid; the requirement for anti-idiotypic monoclonal antibodies to idiotopes within the antigen-combining site of the antibodies to be purified is not likely to represent a major limitation in the broad application of the present method, since the hybridoma technology has greatly facilitated the development of anti-idiotypic monoclonal antibodies. (author). 12 refs.; 4 figs.; 1 tab

  4. Effect of producer cell line on functional activity of anti-D monoclonal antibodies destined for prevention of rhesus sensitization.

    Science.gov (United States)

    Olovnikova, N I; Ershler, M A; Belkina, E V; Nikolaeva, T L; Miterev, G Yu

    2009-04-01

    The ability of anti-D antibodies to cause antigen-specific immunosuppression depends on their interaction with low-affinity Fcgamma-receptors. Human monoclonal antibodies to D antigen of the rhesus system were investigated by antibody-dependent cytotoxicity assay in order to estimate their ability to induce hemolysis mediated by low-affinity Fcgamma receptors. We demonstrate that affinity of monoclonal antibodies to receptors of this type does not depend on primary structure of Fc-fragment, but depends on the producer cell line which expresses the antibodies. Monoclonal IgG1 antibodies interacting with FcgammaRIIa and FcgammaRIII lost this property, if they were secreted by human-mouse heterohybridoma, but not by human B-cell line. On the opposite, monoclonal antibodies that could not activate low-affinity Fcgamma receptors were highly active after human cells fusion with rat myeloma YB2/0. Hemolytic activity of IgG3 remained unchanged after fusion of human cells with rodent cells.

  5. Humanized CD7 nanobody-based immunotoxins exhibit promising anti-T-cell acute lymphoblastic leukemia potential.

    Science.gov (United States)

    Yu, Yuan; Li, Jialu; Zhu, Xuejun; Tang, Xiaowen; Bao, Yangyi; Sun, Xiang; Huang, Yuhui; Tian, Fang; Liu, Xiaomei; Yang, Lin

    2017-01-01

    Nanobodies, named as VHHs (variable domain of heavy chain of HCAb [heavy-chain antibodies]), are derived from heavy-chain-only antibodies that circulate in sera of camelids. Their exceptional physicochemical properties, possibility of humanization, and unique antigen recognition properties make them excellent candidates for targeted delivery of biologically active components, including immunotoxins. In our previous efforts, we have successfully generated the monovalent and bivalent CD7 nanobody-based immunotoxins, which can effectively trigger the apoptosis of CD7-positive malignant cells. To pursue the possibility of translating those immunotoxins into clinics, we humanized the nanobody sequences (designated as dhuVHH6) as well as further truncated the Pseudomonas exotoxin A (PE)-derived PE38 toxin to produce a more protease-resistant form, which is named as PE-LR, by deleting majority of PE domain II. Three new types of immunotoxins, dhuVHH6-PE38, dVHH6-PE-LR, and dhuVHH6-PE-LR, were successfully constructed. These recombinant immunotoxins were expressed in Escherichia coli and showed that nanobody immunotoxins have the benefits of easy soluble expression in a prokaryotic expression system. Flow cytometry results revealed that all immunotoxins still maintained the ability to bind specifically to CD7-positive T lymphocyte strains without binding to CD7-negative control cells. Laser scanning confocal microscopy revealed that these proteins can be endocytosed into the cytoplasm after binding with CD7-positive cells and that this phenomenon was not observed in CD7-negative cells. WST-8 experiments showed that all immunotoxins retained the highly effective and specific growth inhibition activity in CD7-positive cell lines and primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Further in vivo animal model experiments showed that humanized dhuVHH6-PE38 immunotoxin can tolerate higher doses and extend the survival of NOD-Prkdc em26 Il2rg em26 Nju (NCG) mice

  6. The association of the vitamin D status with the persistence of anti-HBs antibody at 20years after primary vaccination with recombinant hepatitis B vaccine in infancy.

    Science.gov (United States)

    Jafarzadeh, A; Keshavarz, J; Bagheri-Jamebozorgi, M; Nemati, M; Frootan, R; Shokri, F

    2017-02-01

    Vitamin D has potent immunoregulatory effects due to the expression of its receptor on the majority of immune cells. The aim was to evaluate the association of the vitamin D status with the persistence of anti-HBs antibody and immune response to booster immunization at 20years after primary vaccination with hepatitis B (HB) vaccine. Blood samples were collected from 300 adults 20years after completion of the primary HB vaccination in infancy. The serum levels of vitamin D and anti-HBs antibody were measured by ELISA. A single booster dose of a recombinant HB vaccine was administered to a total of 138 subjects, whose anti-HBs titer wasanti-HBs antibody, 4weeks after booster vaccination. At 20years after primary vaccination, the mean vitamin D concentrations were significantly higher in seroprotective subjects as compared to non-seroprotective individuals (Panti-HBs were significantly increased with advanced concentrations of vitamin D (PD were significantly higher in subjects with an anamnestic response to booster vaccination as compared with subjects without this response (PD status may influence the persistence of anti-HBs antibody and durability of protection after primary vaccination with a recombinant HB vaccine in infancy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. Evaluation of PLGA containing anti-CTLA4 inhibited endometriosis progression by regulating CD4+CD25+Treg cells in peritoneal fluid of mouse endometriosis model.

    Science.gov (United States)

    Liu, Qi; Ma, Pingchuan; Liu, Lanxia; Ma, Guilei; Ma, Jingjing; Liu, Xiaoxuan; Liu, Yijin; Lin, Wanjun; Zhu, Yingjun

    2017-01-01

    Our study investigated poly(lactic-co-glycolic acid) (PLGA) as protein delivery vehicles encapsulate CTLA-4-antibody (anti-CTLA-4) which is essential for CD4+CD25+Treg cells suppressive function exposing superior potential for inhibiting endometriosis progress in mouse model than single anti-CTLA-4. Anti-CTLA-4 loaded PLGA combined to ligands CTLA-4 in surface of CD4+CD25+Treg cells which distributed in peritoneal fluid of mouse endometriosis model. The particle size, zeta potential of the anti-CTLA-4 loaded nanoparticles was detected by dynamic light scattering. Morphology of nanoparticles was evaluated by transmission electron microscopy (TEM). Confocal laser scanning microscopy (CLSM) indicated distribution of anti-CTLA-4 with PLGA or without in peritoneal fluid. Cumulative anti-CTLA-4 release from nanoparticles was evaluated by Micro BCA assay. The percentage of CD4+CD25+Treg cells in peritoneal fluid was demonstrated by flow cytometer. In vitro experiment we co-culture ectopic endometrial cells (EEC) with isolated CD4+CD25+Treg cells in peritoneal fluid (PF), proliferation and invasion of ectopic endometrial cells (EEC) was measured by BrdU ELISA assay and Matrigel invasion assay. In comparison with anti-CTLA-4 without nanoparticles, the bioconjugates PLGA/anti-CTLA-4 were tolerated in peritoneal fluid with a controlled release of anti-CTLA-4 in 3, 7, 14days. Moreover, PLGA/anti-CTLA-4 had superior protective regulation ability to reduce level of CD4+CD25+Treg cells in peritoneal fluid. Most strikingly, in vitro experiment, PLGA/anti-CTLA-4 exhibited better ability in inhibiting proliferation and invasion of ectopic endometrial cells in co-culture system compared with anti-CTLA-4. Progressively, PLGA/anti-CTLA-4 had better suppressive activity to inhibited IL-10 and TGF-beta secreted by CD4+CD25+Treg cells which indicating that PLGA/anti-CTLA-4 suppressed cells proliferation and invasion through reduced IL-10 and TGF-beta production. Thus, PLGA/anti-CTLA-4 may

  8. Safety, Pharmacokinetics, Immunogenicity, and Biodistribution of (186)Re-Labeled Humanized Monoclonal Antibody BIWA 4 (Bivatuzumab( in Patients with Early-Stage Breast Cancer.

    NARCIS (Netherlands)

    Koppe, M.; Schaijk, F. van; Roos, J.C.; Leeuwen, P.; Heider, K.H.; Kuthan, H.; Bleichrodt, R.P.

    2004-01-01

    The aim of this prospective study was to evaluate the safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized anti-CD44v6 monoclonal antibody (MAb( BIWA 4 (Bivatuzumab( in 9 patients with early-stage breast cancer. Radioimmunoscintigraphy (RIS( was performed within

  9. Human anti-luteinizing hormone-releasing hormone antibodies in patients treated with synthetic luteinizing hormone-releasing hormone

    International Nuclear Information System (INIS)

    Meakin, J.L.; Keogh, E.J.; Martin, C.E.

    1985-01-01

    One hundred sixty-three patients who were given synthetic LH-RH therapeutically underwent monitoring of serum IgG anti-LH-RH antibodies. Five of the patients showed specific binding to antibodies. Development of anti-LH-RH antibodies was not limited to those patients with a congenital deficiency of LH-RH. Urticarial responses occurred in four patients, only one of whom had IgG antibodies. Patients who had IgG antibodies or an urticarial response underwent monitoring of their serum IgE anti-LH-RH antibodies, but none had a positive binding response. The refractory state which has been reported in patients in whom similar antibodies to LH-RH develop was not invariably observed among these patients

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

    Science.gov (United States)

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

    2018-04-10

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

  11. The study of conjugation of anti-CD20 monoclonal antibody for labeling with metallic or lanthanides radionuclides

    International Nuclear Information System (INIS)

    Akanji, Akinkunmi Ganiyu

    2012-01-01

    Lymphomas are malignancies or cancers that start from the malign transformation of a lymphocyte in the lymphatic system. Generally, lymphomas start from the lymph nodes or from the agglomeration of the lymphatic tissues, organs like stomach, intestines, in some cases it can involve the bone marrow and the blood, it can also disseminate to other organs. Lymphomas are divided in two major categories: Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Patient with NHL are generally treated with radiotherapy alone or combined with immunotherapy using monoclonal antibody rituximab (MabThera®). Currently, monoclonal antibodies (Acm) conjugated with bifunctional chelate agents and radiolabeled with metallic or lanthanides radionuclides are a treatment reality for patients with NHL by the principle of radioimmunotherapy (RIT). This study focused on the conditions of conjugation of Acm rituximab (MabThera®) with bifunctional chelating agents DOTA and DTPA. Various parameters were studied: method of Acm purification, conditions of Acm conjugation, the method for determination of number of chelate agent coupled to the Acm, method for purification of the conjugated antibody Acm, conditions of labeling of the conjugated antibody with lutetium-177, method of purification of the radiolabeled immuno conjugate, method of radiochemical purity (RP), specific binding in vitro Raji cells (Human Burkitt) and biological distribution performed in normal Balb-c mouse. The three methodologies employed in pre-purification of Acm (dialysis, size exclusion chromatograph and dial filtration) demonstrated to be efficient; they provided sample recovery exceeding 90%. However, the methodology of dial filtration presents minimal sample loss, and gave the final recovery of the sample in micro liters; thereby facilitating sample use in subsequent experiments. Numbers of chelators attached to the Acm molecule was proportional to the molar ratio studied. When we evaluated the influence of different

  12. [Adult T-cell leukemia/lymphoma associated with unusual positivity of anti-ATLA (adult T-cell leukemia-cell-associated antigen) antibodies].

    Science.gov (United States)

    Eto, T; Okamura, H; Okamura, T; Gondo, H; Kudo, J; Shibuya, T; Harada, M; Niho, Y

    1990-03-01

    A 56-year-old female was admitted because of generalized lymphadenopathy. Based upon histological findings of biopsied lymph node, malignant lymphoma, diffuse large cell type was diagnosed. The surface marker analysis showed that malignant cells were positive for CD4 and CD2 but negative for CD8. Although anti-ATLA (adult T-cell leukemia associated antigen) antibody was negative with the use of a gelatin particle agglutination method (P.A.), other methods such as an indirect immunofluorescence assay (I.F.), an enzyme-linked immunosorbent assay (E.I.A.) and a Western blotting assay revealed the positivity for anti-ATLA antibody. Adult T-cell leukemia/lymphoma (ATL/L) was confirmed by the presence of monoclonal integration of HTLV-I proviral DNA in biopsied specimen. This case, showing a pattern of P.A. (-) and I.F. (+), is extremely unusual, because I.F. and P.A. show highly close correlation. Thus, it is important to employ different methods for screening of anti-ATLA antibodies in the diagnosis of ATL/L.

  13. Amelioration of murine passive immune thrombocytopenia by IVIg and a therapeutic monoclonal CD44 antibody does not require the Myd88 signaling pathway.

    Directory of Open Access Journals (Sweden)

    Andrew R Crow

    Full Text Available Immune thrombocytopenia (ITP is an autoimmune bleeding disorder characterized by a low platelet count and the production of anti-platelet antibodies. The majority of ITP patients have antibodies to platelet integrin α(IIbβ₃ (GPIIbIIIa which can direct platelet phagocytosis by macrophages. One effective treatment for patients with ITP is intravenous immunoglobulin (IVIg which rapidly reverses thrombocytopenia. The exact mechanism of IVIg action in human patients is unclear, although in mouse models of passive ITP, IVIg can rapidly increase platelet counts in the absence of adaptive immunity. Another antibody therapeutic that can similarly increase platelet counts independent of adaptive immunity are CD44 antibodies. Toll-like receptors (TLRs are pattern recognition receptors which play a central role in helping direct the innate immune system. Dendritic cells, which are notable for their expression of TLRs, have been directly implicated in IVIg function as an initiator cell, while CD44 can associate with TLR2 and TLR4. We therefore questioned whether IVIg, or the therapeutic CD44 antibody KM114, mediate their ameliorative effects in a manner dependent upon normal TLR function. Here, we demonstrate that the TLR4 agonist LPS does not inhibit IVIg or KM114 amelioration of antibody-induced thrombocytopenia, and that these therapeutics do not ameliorate LPS-induced thrombocytopenia. IVIg was able to significantly ameliorate murine ITP in C3H/HeJ mice which have defective TLR4. All known murine TLRs except TLR3 utilize the Myd88 adapter protein to drive TLR signaling. Employing Myd88 deficient mice, we found that both IVIg and KM114 ameliorate murine ITP in Myd88 deficient mice to the same extent as normal mice. Thus both IVIg and anti-CD44 antibody can mediate their ameliorative effects in murine passive ITP independent of the Myd88 signaling pathway. These data help shed light on the mechanism of action of IVIg and KM114 in the amelioration of

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

    Science.gov (United States)

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

    2015-06-01

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

  15. Enhanced opsonisation of Rhesus D-positive human red blood cells by recombinant polymeric immunoglobulin G anti-G antibodies.

    Science.gov (United States)

    Díaz-Solano, Dylana; Fuenmayor, Jaheli; Montaño, Ramon F

    2018-02-01

    Anti-RhD antibodies (anti-D) are important in the prophylaxis of haemolytic disease of the foetus and newborn (HDFN) due to RhD incompatibility. Current preparations of anti-D are sourced from hyperimmune human plasma, so its production carries a risk of disease and is dependent on donor availability. Despite the efforts to develop a monoclonal preparation with similar prophylactic properties to the plasma-derived anti-D, no such antibody is yet available. Here we studied the agglutinating, opsonic and haemolytic activities of two recombinant polymeric immunoglobulins (Ig) against the G antigen of the Rh complex. Recombinant polymeric anti-G IgG1 (IgG1μtp) and IgG3 (IgG3μtp) were produced in vitro, purified by protein G-affinity chromatography, and analysed by gel electrophoresis. Their agglutinating, opsonic and haemolytic activities were evaluated using haemagglutination, erythrophagocytosis, and complement activation assays. The recombinant IgG1μtp and IgG3μtp anti-G antibodies ranged from 150,000 to 1,000,000 Da in molecular weight, indicating the formation of polymeric IgG. No complement activation or haemolytic activity was detected upon incubation of RhD-positive red-blood cells with the polymeric anti-G IgG. Both polymers were better opsonins than a prophylactic preparation of plasma-derived anti-D. The enhanced opsonic properties of the polymeric anti-G IgG1μtp and IgG3μtp could allow them to mediate the clearance of RhD-positive red blood cells from circulation more efficiently than natural or other synthetic prophylactic anti-D options. Their inability to induce complement-mediated haemolysis would be prophylactically convenient and is comparable in vitro to that of the available plasma-derived polyclonal anti-D preparations. The described properties suggest that polymeric antibodies like these (but with anti-D specificity) may be testable candidates for prophylaxis of HDFN caused by anti-D.

  16. Monoclonal antibodies against human angiotensinogen, their characterization and use in an angiotensinogen enzyme linked immunosorbent assay.

    Science.gov (United States)

    Rubin, I; Lykkegaard, S; Olsen, A A; Selmer, J; Ballegaard, M

    1988-01-01

    Monoclonal antibodies were produced against human angiotensinogen. An enzyme linked immunosorbent assay (ELISA) was developed using a high affinity monoclonal antibody as catching antibody and a polyclonal rabbit anti human angiotensinogen antibody as detecting antibody in a "sandwich" ELISA. Linear range of the ELISA was 15-450 pmol/l of human angiotensinogen. Intra- and inter- assay variation coefficients were in the range of 2% to 8%. A correlation coefficient, r = 0.97, (n = 20), with values obtained by radioimmunoassay. This correlation coefficient, obtained by using both normal and pregnant sera, confirmed that the ELISA fulfill the requirements for clinical useful assay. Characterization of the antibodies were performed with respect to affinity constant and epitopes.

  17. The study of conjugation of anti-CD20 monoclonal antibody for labeling with metallic or lanthanides radionuclides; Estudo de conjugacao do anticorpo anti-CD20 para marcacao com radionuclideos metalicos ou lantanideos

    Energy Technology Data Exchange (ETDEWEB)

    Akanji, Akinkunmi Ganiyu

    2012-07-01

    Lymphomas are malignancies or cancers that start from the malign transformation of a lymphocyte in the lymphatic system. Generally, lymphomas start from the lymph nodes or from the agglomeration of the lymphatic tissues, organs like stomach, intestines, in some cases it can involve the bone marrow and the blood, it can also disseminate to other organs. Lymphomas are divided in two major categories: Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Patient with NHL are generally treated with radiotherapy alone or combined with immunotherapy using monoclonal antibody rituximab (MabThera Registered-Sign ). Currently, monoclonal antibodies (Acm) conjugated with bifunctional chelate agents and radiolabeled with metallic or lanthanides radionuclides are a treatment reality for patients with NHL by the principle of radioimmunotherapy (RIT). This study focused on the conditions of conjugation of Acm rituximab (MabThera Registered-Sign ) with bifunctional chelating agents DOTA and DTPA. Various parameters were studied: method of Acm purification, conditions of Acm conjugation, the method for determination of number of chelate agent coupled to the Acm, method for purification of the conjugated antibody Acm, conditions of labeling of the conjugated antibody with lutetium-177, method of purification of the radiolabeled immuno conjugate, method of radiochemical purity (RP), specific binding in vitro Raji cells (Human Burkitt) and biological distribution performed in normal Balb-c mouse. The three methodologies employed in pre-purification of Acm (dialysis, size exclusion chromatograph and dial filtration) demonstrated to be efficient; they provided sample recovery exceeding 90%. However, the methodology of dial filtration presents minimal sample loss, and gave the final recovery of the sample in micro liters; thereby facilitating sample use in subsequent experiments. Numbers of chelators attached to the Acm molecule was proportional to the molar ratio studied. When we evaluated

  18. The antibody response against human and chimeric anti-TNF therapeutic antibodies primarily targets the TNF binding region

    NARCIS (Netherlands)

    van Schie, K. A.; Hart, M. H.; de Groot, E. R.; Kruithof, S.; Aarden, L. A.; Wolbink, G. J.; Rispens, T.

    2015-01-01

    In a subset of patients, anti tumour necrosis factor (TNF) therapeutic antibodies are immunogenic, resulting in the formation of antidrug antibodies (ADAs). Neutralising ADAs compete with TNF for its binding site and reduces the effective serum concentration, causing clinical non-response. It is

  19. Infection of human and non-human cells by a highly fusogenic primary CD4-independent HIV-1 isolate with a truncated envelope cytoplasmic tail

    International Nuclear Information System (INIS)

    Saha, Kunal; Yan Hui; Nelson, Julie A.E.; Zerhouni-Layachi, Bouchra

    2005-01-01

    Truncation of the envelope cytoplasmic tail has enabled FIV, SIV, and some laboratory HIV-1 strains to acquire broader cellular tropism and enhanced fusogenicity. Here we have characterized a primary CD4-independent HIV-1 isolate (92UG046-T8) with a truncated cytoplasmic tail that was able to infect and induce syncytia in primary lymphocytes from human, chimpanzee, and monkey, as well as CD4-negative cell lines from human and monkey. Increased syncytia were also noticeable with 293 cells expressing the cloned envelope from the 92UG046-T8 isolate suggesting envelope-mediated cellular fusion. Except pooled serum from HIV-1-infected individuals, monoclonal anti-envelope antibodies or antibodies/antagonists against CD4, CXCR4, and CCR5 were not able to prevent infection by the 92UG046-T8 isolate. This is the first report showing a primary HIV-1 variant with truncated cytoplasmic tail which is highly fusogenic and can infect a broad range of cells from human and non-human origins. In vivo evolution of similar HIV-1 mutants may have important implications in AIDS pathogenesis

  20. Synergistic anti-tumor therapy by a comb-like multifunctional antibody nanoarray with exceptionally potent activity

    Science.gov (United States)

    Li, Huafei; Sun, Yun; Chen, Di; Zhao, He; Zhao, Mengxin; Zhu, Xiandi; Ke, Changhong; Zhang, Ge; Jiang, Cheng; Zhang, Li; Zhang, Fulei; Wei, Huafeng; Li, Wei

    2015-10-01

    Simultaneously blocking multiple mediators offers new hope for the treatment of complex diseases. However, the curative potential of current combination therapy by chronological administration of separate monoclonal antibodies (mAbs) or multi-specific mAbs is still moderate due to inconvenient manipulation, low cooperative effectors, poor pharmacokinetics and insufficient tumor accumulation. Here, we describe a facile strategy that arms distinct mAbs with cooperative effectors onto a long chain to form a multicomponent comb-like nano mAb. Unlike dissociative parental mAbs, the multifunctional mAb nanoarray (PL-RB) constructed from type I/II anti-CD20 mAbs shows good pharmacokinetics. This PL-RB simultaneously targets distinct epitopes on a single antigen (Ag) and neighboring Ags on different lymphocytes. This unique intra- and intercellular Ag cross-linking endows the multifunctional mAb nanoarray with potent apoptosis activity. The exceptional apoptosis, complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) that are synchronously evoked by the nano PL-RB are further synergistically promoted via enhanced permeability and retention (EPR), which resulted in high intratumor accumulation and excellent anti-lymphoma efficiency.

  1. Soluble CD30 and Cd27 levels in patients undergoing HLA antibody-incompatible renal transplantation.

    Science.gov (United States)

    Hamer, Rizwan; Roche, Laura; Smillie, David; Harmer, Andrea; Mitchell, Daniel; Molostvov, Guerman; Lam, For T; Kashi, Habib; Tan, Lam Chin; Imray, Chris; Fletcher, Simon; Briggs, David; Lowe, David; Zehnder, Daniel; Higgins, Rob

    2010-08-01

    HLA antibody-incompatible transplantation has a higher risk of rejection when compared to standard renal transplantation. Soluble CD30 (sCD30) has been shown in many, but not all, studies to be a biomarker for risk of rejection in standard renal transplant recipients. We sought to define the value of sCD30 and soluble CD27 (sCD27) in patients receiving HLA antibody-incompatible transplants. Serum taken at different time points from 32 HLA antibody-incompatible transplant recipients was retrospectively assessed for sCD30 and sCD27 levels by enzyme-linked immunosorbent assay (ELISA). This was compared to episodes of acute rejection, post-transplant donor-specific antibody (DSA) levels and 12 month serum creatinine levels. No association was found between sCD27 and sCD30 levels and risk of acute rejection or DSA levels. Higher sCD30 levels at 4-6 weeks post-transplantation were associated with a higher serum creatinine at 12 months. Conclusion patients undergoing HLA antibody-incompatible transplantation are at a high risk of rejection but neither sCD30 (unlike in standard transplantation) nor sCD27 was found to be a risk factor. High sCD30 levels measured at 4-6 weeks post-transplantation was associated with poorer graft function at one year. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Highly efficient elimination of colorectal tumor-initiating cells by an EpCAM/CD3-bispecific antibody engaging human T cells.

    Directory of Open Access Journals (Sweden)

    Ines Herrmann

    2010-10-01

    Full Text Available With their resistance to genotoxic and anti-proliferative drugs and potential to grow tumors and metastases from very few cells, cancer stem or tumor-initiating cells (TICs are a severe limitation for the treatment of cancer by conventional therapies. Here, we explored whether human T cells that are redirected via an EpCAM/CD3-bispecific antibody called MT110 can lyse colorectal TICs and prevent tumor growth from TICs. MT110 recognizes EpCAM, a cell adhesion molecule expressed on TICs from diverse human carcinoma, which was recently shown to promote tumor growth through engagement of elements of the wnt pathway. MT110 was highly potent in mediating complete redirected lysis of KRAS-, PI3 kinase- and BRAF-mutated colorectal TICs, as demonstrated in a soft agar assay. In immunodeficient mice, MT110 prevented growth of tumors from a 5,000-fold excess of a minimally tumorigenic TIC dose. T cells engaged by MT110 may provide a potent therapeutic means to eradicate TICs and bulk tumor cells derived thereof.

  3. Anti-glucagon antibodies in diabetes mellitus

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    Gergely, A; Koranyi, L; Halmos, T; Zsombok, M; Peterfy, F; Csizer, Z; Salamon, F; Tako, J

    1973-01-01

    Anti-insulin antibodies appear in the sera of patients treated with insulin lastingly. A high anti-insulin antibody level results in the development of insulin resistance. Most of the insulin preparations available on the market contain also glucagon as an impurity. It was therefore to be expected that in part of the patients, who had been treated with insulin lastingly, antibodies would be produced also against glucagon, and the presence of these was actually demonstrated. It is to be assumed that the anti-glucagon antibodies play a role in the pathomechanism of diabetes mellitus, mainly in its labile form. The possible presence of anti-glucagon antibodies must be taken into account when the glucagon concentration in the sera of diabetics is to be determined by means of radioimmunoassay (RIA). The specific antibodies in the serum give false results in the quantitative determination of glucagon. We have tested the sera of 10 diabetics who had been treated with insulin for at least 6 years. All patients were given protamine zinc and crystalline insulin preparations.

  4. Cetuximab in combination with anti-human IgG antibodies efficiently down-regulates the EGF receptor by macropinocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Christian [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Madshus, Inger Helene [Institute of Pathology, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Stang, Espen, E-mail: espsta@rr-research.no [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway)

    2012-12-10

    The monoclonal antibody C225 (Cetuximab) blocks binding of ligand to the epidermal growth factor receptor (EGFR). In addition, it is known that incubation with C225 induces endocytosis of the EGFR. This endocytosis has previously been shown to be increased when C225 is combined with an additional monoclonal anti-EGFR antibody. However, the effects of antibody combinations on EGFR activation, endocytosis, trafficking and degradation have been unclear. By binding a secondary antibody to the C225-EGFR complex, we here demonstrate that a combination of antibodies can efficiently internalize and degrade the EGFR. Although the combination of antibodies activated the EGFR kinase and induced ubiquitination of the EGFR, the kinase activity was not required for internalization of the EGFR. In contrast to EGF-induced EGFR down-regulation, the antibody combination efficiently degraded the EGFR without initiating downstream proliferative signaling. The antibody-induced internalization of EGFR was found not to depend on clathrin and/or dynamin, but depended on actin polymerization, suggesting induction of macropinocytosis. Macropinocytosis may cause internalization of large membrane areas, and this could explain the highly efficient internalization of the EGFR induced by combination of antibodies. -- Highlight: Black-Right-Pointing-Pointer Cetuximab induced endocytosis of EGFR increases upon combination with anti-human IgG. Black-Right-Pointing-Pointer Antibody combination causes internalization of EGFR by macropinocytosis. Black-Right-Pointing-Pointer Antibody-induced internalization of EGFR is independent of EGFR kinase activity. Black-Right-Pointing-Pointer Antibody combination may have a zipper effect and cross-link EGFRs on neighboring cells.

  5. Carbamylated albumin is one of the target antigens of anti-carbamylated protein antibodies.

    Science.gov (United States)

    Nakabo, Shuichiro; Hashimoto, Motomu; Ito, Shinji; Furu, Moritoshi; Ito, Hiromu; Fujii, Takao; Yoshifuji, Hajime; Imura, Yoshitaka; Nakashima, Ran; Murakami, Kosaku; Kuramoto, Nobuo; Tanaka, Masao; Satoh, Junko; Ishigami, Akihito; Morita, Satoshi; Mimori, Tsuneyo; Ohmura, Koichiro

    2017-07-01

    Anti-carbamylated protein (anti-CarP) antibodies are detected in RA patients. Fetal calf serum is used as an antigen source in anti-CarP ELISA, and the precise target antigens have not been found. We aimed to identify the target antigens of anti-CarP antibodies. Western blotting of anti-CarP antibodies was conducted. Anti-carbamylated human albumin (CarALB) antibody was detected by in-house ELISA for 493 RA patients and 144 healthy controls (HCs). An inhibition ELISA of anti-CarP antibodies by CarALB and citrullinated albumin (citALB) was performed using eight RA patients' sera. Serum CarALB was detected by liquid chromatography-tandem mass spectroscopy (LC/MS/MS), and the serum MPO concentration was measured by ELISA. We focused on carbamylated albumin because it corresponded to the size of the thickest band detected by western blotting of anti-CarP antibodies. Anti-CarALB antibody was detected in 31.4% of RA patients, and the correlation of the titres between anti-CarALB and anti-CarP was much closer than that between anti-citALB and anti-CCP antibodies (ρ = 0.59 and ρ = 0.16, respectively). The inhibition ELISA showed that anti-CarP antibodies were inhibited by CarALB, but not by citALB. CarALB was detected in sera from RA patients by LC/MS/MS. The serum MPO concentration was correlated with disease activity and was higher in RA patients with anti-CarALB antibody than in those without. We found that carbamylated albumin is a novel target antigen of anti-CarP antibodies, and it is the first reported target antigen that has not been reported as the target of ACPA. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  6. Antibody-Dependent Cellular Cytotoxicity Activity of a Novel Anti-PD-L1 Antibody Avelumab (MSB0010718C) on Human Tumor Cells.

    Science.gov (United States)

    Boyerinas, Benjamin; Jochems, Caroline; Fantini, Massimo; Heery, Christopher R; Gulley, James L; Tsang, Kwong Yok; Schlom, Jeffrey

    2015-10-01

    Several anti-PD-1/PD-L1 monoclonal antibodies (mAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these mAbs is to inhibit PD-1 on immune cells interacting with PD-L1 on tumor cells. These mAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective mAb-mediated cancer therapies. A fully human anti-PD-L1 mAb would potentially be able to block PD-1/PD-L1 interactions and also mediate the ADCC lysis of tumor cells. MSB0010718C (designated avelumab) is a fully human IgG1 anti-PD-L1 mAb. The studies reported here demonstrate (i) the ability of avelumab to lyse a range of human tumor cells in the presence of PBMC or NK effectors; (ii) IFNγ can enhance tumor cell PD-L1 expression and, in some cases, enhance ADCC tumor cell lysis; (iii) purified NK cells are potent effectors for avelumab; (iv) similar levels of avelumab-mediated ADCC lysis of tumor cells are seen using purified NK as effectors from either healthy donors or cancer patients; (v) very low levels of avelumab-mediated lysis are seen using whole PBMCs as targets; this finding complements results seen in analyses of PBMC subsets of patients receiving avelumab; and (vi) the addition of IL12 to NK cells greatly enhances avelumab-mediated ADCC. These studies thus provide an additional mode of action for an anti-PD-L1 mAb and support the rationale for further studies to enhance avelumab-mediated ADCC activity. ©2015 American Association for Cancer Research.

  7. Agonist anti-GITR antibody significantly enhances the therapeutic efficacy of Listeria monocytogenes-based immunotherapy.

    Science.gov (United States)

    Shrimali, Rajeev; Ahmad, Shamim; Berrong, Zuzana; Okoev, Grigori; Matevosyan, Adelaida; Razavi, Ghazaleh Shoja E; Petit, Robert; Gupta, Seema; Mkrtichyan, Mikayel; Khleif, Samir N

    2017-08-15

    We previously demonstrated that in addition to generating an antigen-specific immune response, Listeria monocytogenes (Lm)-based immunotherapy significantly reduces the ratio of regulatory T cells (Tregs)/CD4 + and myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment. Since Lm-based immunotherapy is able to inhibit the immune suppressive environment, we hypothesized that combining this treatment with agonist antibody to a co-stimulatory receptor that would further boost the effector arm of immunity will result in significant improvement of anti-tumor efficacy of treatment. Here we tested the immune and therapeutic efficacy of Listeria-based immunotherapy combination with agonist antibody to glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) in TC-1 mouse tumor model. We evaluated the potency of combination on tumor growth and survival of treated animals and profiled tumor microenvironment for effector and suppressor cell populations. We demonstrate that combination of Listeria-based immunotherapy with agonist antibody to GITR synergizes to improve immune and therapeutic efficacy of treatment in a mouse tumor model. We show that this combinational treatment leads to significant inhibition of tumor-growth, prolongs survival and leads to complete regression of established tumors in 60% of treated animals. We determined that this therapeutic benefit of combinational treatment is due to a significant increase in tumor infiltrating effector CD4 + and CD8 + T cells along with a decrease of inhibitory cells. To our knowledge, this is the first study that exploits Lm-based immunotherapy combined with agonist anti-GITR antibody as a potent treatment strategy that simultaneously targets both the effector and suppressor arms of the immune system, leading to significantly improved anti-tumor efficacy. We believe that our findings depicted in this manuscript provide a promising and translatable strategy that can enhance the overall

  8. Intravitreally Injected Anti-VEGF Antibody Reduces Brown Fat in Neonatal Mice.

    Science.gov (United States)

    Jo, Dong Hyun; Park, Sung Wook; Cho, Chang Sik; Powner, Michael B; Kim, Jin Hyoung; Fruttiger, Marcus; Kim, Jeong Hun

    2015-01-01

    Anti-vascular endothelial growth factor (VEGF) agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal disorder in premature infants. However, the risks of systemic complications after intravitreal injection of anti-VEGF antibody in infants are not well understood. In this study, we show that intravitreally injected anti-VEGF antibody is transported into the systemic circulation into the periphery where it reduces brown fat in neonatal C57BL/6 mice. A considerable amount of anti-VEGF antibody was detected in serum after intravitreal injection. Furthermore, in interscapular brown adipose tissue, we found lipid droplet accumulation, decreased VEGF levels, loss of vascular network, and decreased expression of mitochondria-related genes, Ppargc1a and Ucp1, all of which are characteristics of "whitening" of brown fat. With increasing age and body weight, brown fat restored its morphology and vascularity. Our results show that there is a transient, but significant impact of intravitreally administered anti-VEGF antibody on brown adipose tissue in neonatal mice. We suggest that more attention should be focused on the metabolic and developmental significance of brown adipose tissue in bevacizumab treated retinopathy of prematurity infants.

  9. Intravitreally Injected Anti-VEGF Antibody Reduces Brown Fat in Neonatal Mice.

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    Dong Hyun Jo

    Full Text Available Anti-vascular endothelial growth factor (VEGF agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal