WorldWideScience

Sample records for cell antibody anti-ca

  1. A new Purkinje cell antibody (anti-Ca associated with subacute cerebellar ataxia: immunological characterization

    Directory of Open Access Journals (Sweden)

    Horn Sigrun

    2010-03-01

    Full Text Available Abstract We report on a newly discovered serum and cerebrospinal fluid (CSF reactivity to Purkinje cells (PCs associated with subacute inflammatory cerebellar ataxia. The patient, a previously healthy 33-year-old lady, presented with severe limb and gait ataxia, dysarthria, and diplopia two weeks after she had recovered from a common cold. Immunohistochemical studies on mouse, rat, and monkey brain sections revealed binding of a high-titer (up to 1:10,000 IgG antibody to the cerebellar molecular layer, Purkinje cell (PC layer, and white matter. The antibody is highly specific for PCs and binds to the cytoplasm as well as to the inner side of the membrane of PC somata, dendrites and axons. It is produced by B cell clones within the CNS, belongs to the IgG1 subclass, and activates complement in vitro. Western blotting of primate cerebellum extract revealed binding of CSF and serum IgG to an 80-97 kDa protein. Extensive control studies were performed to rule out a broad panel of previously described paraneoplastic and non-paraneoplastic antibodies known to be associated with cerebellar ataxia. Screening of >9000 human full length proteins by means of a protein array and additional confirmatory experiments revealed Rho GTPase activating protein 26 (ARHGAP26, GRAF, oligophrenin-1-like protein as the target antigen. Preadsorption of the patient's serum with human ARHGAP26 but not preadsorption with other proteins resulted in complete loss of PC staining. Our findings suggest a role of autoimmunity against ARHGAP26 in the pathogenesis of subacute inflammatory cerebellar ataxia, and extend the panel of diagnostic markers for this devastating disease.

  2. Two new cases of anti-Ca (anti-ARHGAP26/GRAF autoantibody-associated cerebellar ataxia

    Directory of Open Access Journals (Sweden)

    Jarius Sven

    2013-01-01

    Full Text Available Abstract Recently, we discovered a novel serum and cerebrospinal fluid (CSF autoantibody (anti-Ca to Purkinje cells in a patient with autoimmune cerebellar ataxia (ACA and identified the RhoGTPase-activating protein 26 (ARHGAP26; alternative designations include GTPase regulator associated with focal adhesion kinase pp125, GRAF, and oligophrenin-1-like protein, OPHN1L as the target antigen. Here, we report on two new cases of ARHGAP26 autoantibody-positive ACA that were first diagnosed after publication of the index case study. While the index patient developed ACA following an episode of respiratory infection with still no evidence for malignancy 52 months after onset, neurological symptoms heralded ovarian cancer in one of the patients described here. Our finding of anti-Ca/anti-ARHGAP26 antibodies in two additional patients supports a role of autoimmunity against ARHGAP26 in the pathogenesis of ACA. Moreover, the finding of ovarian cancer in one of our patients suggests that anti-Ca/anti-ARHGAP26-positive ACA might be of paraneoplastic aetiology in some cases. In conclusion, testing for anti-Ca/anti-ARHGAP26 should be included in the diagnostic work-up of patients with ACA, and an underlying tumour should be considered in patients presenting with anti-Ca/ARHGAP26 antibody-positive ACA.

  3. Autologous antibodies that bind neuroblastoma cells.

    Science.gov (United States)

    Sun, Yujing; Sholler, Giselle S; Shukla, Girja S; Pero, Stephanie C; Carman, Chelsea L; Zhao, Ping; Krag, David N

    2015-11-01

    Antibody therapy of neuroblastoma is promising and our goal is to derive antibodies from patients with neuroblastoma for developing new therapeutic antibodies. The feasibility of using residual bone marrow obtained for clinical indications as a source of tumor cells and a source of antibodies was assessed. From marrow samples, neuroblastoma cells were recovered, grown in cell culture and also implanted into mice to create xenografts. Mononuclear cells from the marrow were used as a source to generate phage display antibody libraries and also hybridomas. Growth of neuroblastoma patient cells was possible both in vitro and as xenografts. Antibodies from the phage libraries and from the monoclonal hybridomas bound autologous neuroblastoma cells with some selectivity. It appears feasible to recover neuroblastoma cells from residual marrow specimens and to generate human antibodies that bind autologous neuroblastoma cells. Expansion of this approach is underway to collect more specimens, optimize methods to generate antibodies, and to evaluate the bioactivity of neuroblastoma-binding antibodies. PMID:26210205

  4. Red Blood Cell Antibody Identification

    Science.gov (United States)

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

  5. Patient-Derived Antibody Targets Tumor Cells

    Science.gov (United States)

    An NCI Cancer Currents blog on an antibody derived from patients that killed tumor cells in cell lines of several cancer types and slowed tumor growth in mouse models of brain and lung cancer without evidence of side effects.

  6. Synthetic Antibodies for Reversible Cell Recognition

    Science.gov (United States)

    Zhou, Jing Zhou

    2011-12-01

    Antibody-mediated cell recognition plays a critical role in various biological and biomedical applications. However, strong antibody-cell interactions can lead to the difficulty of separating antibodies from the bound cells in a simple and non-destructive manner, which is often necessary to numerous applications such as cell sorting or separation. Thus, this thesis research is aimed to create an antibody-like nanomaterial with the function of reversible cell recognition It was hypothesized that nucleic acid aptamer and dendrimer could be used as fundamental structural components to develop an antibody-like nanomaterial. The aptamer functions as the binding site of an antibody; the dendrimer is used as a robust, defined nano-scaffold to support the aptamer and to carry small molecules (e.g., fluorophores). To test this hypothesis, a novel method was first developed to discover the essential nucleotides of full-length aptamers to mimic the binding sites of antibodies. The essential nucleotides were further conjugated with a dendrimer to synthesize a monovalent aptamer-dendrimer nanomaterial. The results clearly showed that the essential nucleotides could maintain high affinity and specificity after tethered on dendrimer surface. To further test the hypothesis that antibody-like nanomaterials can be rationally designed to acquire the capability of reversible cell recognition, an aptamer that was selected at 0 °C was used as a model to synthesize a "Y-shaped" nanomaterial by conjugating two aptamers to the same dendrimer. The results showed that the nanomaterial-cell interaction could be affected by the distance between two binding aptamers. In addition, the "Y-shaped" antibody-like nanomaterial could bind target cells more strongly than its monovalent control. Importantly, the strong cell-nanomaterial interaction could be rapidly reversed when the temperature was shifted from 0 °C to 37 °C. In summary, we developed a synthetic antibody that can not only mimic the

  7. The antibody approach of labeling blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.

    1991-12-31

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are criticality assessed and evaluated.

  8. The antibody approach of labeling blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.

    1992-12-31

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are critically assessed and evaluated.

  9. The antibody approach of labeling blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.

    1991-01-01

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are criticality assessed and evaluated.

  10. The antibody approach of labeling blood cells

    International Nuclear Information System (INIS)

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are critically assessed and evaluated

  11. The antibody approach of labeling blood cells

    International Nuclear Information System (INIS)

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are criticality assessed and evaluated

  12. Antibody Discovery via Multiplexed Single Cell Characterization

    OpenAIRE

    Harriman, William D.; Collarini, Ellen J.; Sperinde, Gizette V.; Strandh, Magnus; Fatholahi, Marjan M.; Dutta, April; Lee, Yunji; Mettler, Shelley E.; Keyt, Bruce A.; Ellsworth, Stote L.; Kauvar, Lawrence M.

    2008-01-01

    The secreted immunoglobulin footprint of single hybridoma cells, containing ~10 fg of antibody purified in situ, has been probed for 9 properties concurrently by use of detection labels comprising 280 nm combinatorially colored fluorescent latex beads functionalized with proteins. Specificity of each individual hybridoma cell’s product has thereby been assessed in a primary screen. Varying the density of antigen on beads to modulate the avidity of the interaction between bead and secreted ant...

  13. Antibodies to human fetal erythroid cells from a nonimmune phage antibody library

    OpenAIRE

    Huie, Michael A.; Cheung, Mei-Chi; Muench, Marcus O.; Becerril, Baltazar; Kan, Yuet W.; Marks, James D.

    2001-01-01

    The ability to isolate fetal nucleated red blood cells (NRBCs) from the maternal circulation makes possible prenatal genetic analysis without the need for diagnostic procedures that are invasive for the fetus. Such isolation requires antibodies specific to fetal NRBCs. To generate a panel of antibodies to antigens present on fetal NRBCs, a new type of nonimmune phage antibody library was generated in which multiple copies of antibody fragments are displayed on each pha...

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

    Science.gov (United States)

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

    2009-01-01

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

  15. Cell adhesion molecules: detection with univalent second antibody

    OpenAIRE

    1980-01-01

    Identification of cell surface molecules that play a role in cell-cell adhesion (here called cell adhesion molecules) has been achieved by demonstrating the inhibitory effect of univalent antibodies that bind these molecules in an in vitro assay of cell-cell adhesion. A more convenient reagent, intact (divalent) antibody, has been avoided because it might agglutinate the cells rather than blocking cell-cell adhesion. In this report, we show that intact rabbit immunoglobulin directed against c...

  16. Design of a bifunctional fusion protein for ovarian cancer drug delivery: single-chain anti-CA125 core-streptavidin fusion protein.

    Science.gov (United States)

    Wang, Welson Wen-Shang; Das, Dipankar; McQuarrie, Stephen A; Suresh, Mavanur R

    2007-03-01

    We have developed a universal ovarian cancer cell targeting vehicle that can deliver biotinylated therapeutic drugs. A single-chain antibody variable domain (scFv) that recognizes the CA125 antigen of ovarian cancer cells was fused with a core-streptavidin domain (core-streptavidin-VL-VH and VL-VH-core-streptavidin orientations) using recombinant DNA technology and then expressed in Escherichia coli using the T7 expression system. The bifunctional fusion protein (bfFp) was expressed in a shaker flask culture, extracted from the periplasmic soluble protein, and affinity purified using an IMAC column. The two distinct activities (biotin binding and anti-CA125) of the bfFp were demonstrated using ELISA, Western blot and confocal laser-scanning microscopy (CLSM). The ELISA method utilized human NIH OVCAR-3 cells along with biotinylated bovine serum albumin (B-BSA) or biotinylated liposomes, whereas, the Western blot involved probing with B-BSA. The CLSM study has shown specificity in binding to the OVCAR-3 cell-line. ELISA and Western blot studies have confirmed the bifunctional activity and specificity. In the presence of bfFp, there was enhanced binding of biotinylated antigen and liposome to OVCAR-3 cells. In contrast, the control EMT6 cells, which do not express the CA125 antigen, showed minimal binding of the bfFp. Consequently, bfFp based targeting of biotinylated therapeutic drugs, proteins, liposomes, or nanoparticles could be an alternative, convenient method to deliver effective therapy to ovarian cancer patients. Peritoneal infusion of the bfFp-therapeutic complex could also be effective in locally targeting the most common site of metastatic spread. PMID:17257818

  17. Development of antibodies to human embryonic stem cell antigens

    OpenAIRE

    Stanley Marisa; Rao Mahendra S; Olson Judith M; Cai Jingli; Taylor Eva; Ni Hsiao-Tzu

    2005-01-01

    Abstract Background Using antibodies to specific protein antigens is the method of choice to assign and identify cell lineage through simultaneous analysis of surface molecules and intracellular markers. Embryonic stem cell research can be benefited from using antibodies specific to transcriptional factors/markers that contribute to the "stemness" phenotype or critical for cell lineage. Results In this report, we have developed and validated antibodies (either monoclonal or polyclonal) specif...

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

    OpenAIRE

    Marlitt Stech; Stefan Kubick

    2015-01-01

    Engineered antibodies are key players in therapy, diagnostics and research. In addition to full size immunoglobulin gamma (IgG) molecules, smaller formats of recombinant antibodies, such as single-chain variable fragments (scFv) and antigen binding fragments (Fab), have emerged as promising alternatives since they possess different advantageous properties. Cell-based production technologies of antibodies and antibody fragments are well-established, allowing researchers to design and manufactu...

  19. B cells contribute to MS pathogenesis through antibody-dependent and antibody-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Wilson HL

    2012-05-01

    Full Text Available Heather L Wilson1,21Vaccine and Infectious Disease Organization-International Vaccine Center, 2Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaAbstract: For many years, central dogma defined multiple sclerosis (MS as a T cell-driven autoimmune disorder; however, over the past decade there has been a burgeoning recognition that B cells contribute to the pathogenesis of certain MS disease subtypes. B cells may contribute to MS pathogenesis through production of autoantibodies (or antibodies directed at foreign bodies, which unfortunately cross-react with self-antigens, through promotion of T cell activation via antigen presentation, or through production of cytokines. This review highlights evidence for antibody-dependent and antibody-independent B cell involvement in MS pathogenesis.Keywords: autoantibodies, antibody targets, clinically isolated MS, primary progressive MS, secondary progressive MS, relapsing and remitting MS, T cells, T regulatory cells

  20. Langerhans' cells, veiled cells, and interdigitating cells in the mouse recognized by a monoclonal antibody

    OpenAIRE

    1986-01-01

    An mAb, NLDC-145, is described that specifically reacts with a group of nonlymphoid dendritic cells including Langerhans cells (LC), veiled cells (VC), and interdigitating cells (IDC). The antibody does not react with precursor cells in bone marrow and blood. Macrophages are not stained by the antibody, but a subpopulation of Ia+ peritoneal exudate cells is recognized. Possible relationships of the various nonlymphoid dendritic cell (NLDC) types are discussed.

  1. Transfusion management of patients with red blood cell antibodies

    Directory of Open Access Journals (Sweden)

    Bujandrić Nevenka B.

    2013-01-01

    Full Text Available Introduction. Red blood cell antibodies may cause a positive result of pre-transfusion blood compatibility testing (crossmatch test. It can be a problem to provide suitable blood units for patients with clinically significant antibodies to high-frequency antigens as well as for those with multiple alloantibody specificities. This study was aimed at identifying transfused patients in the population of South-Backa who had developed clinically significant red blood cell alloantibodies. Material and methods. We analyzed the records of crossmatch results and antibody screening performed at the Blood Transfusion Institute of Vojvodina during 2012. Results. Antibodies were found in 103 patients: A 63 patients with single antibodies: 1 16 with antibodies of unknown specificity (3 autoantibodies, 13 alloantibodies; 2 39 with clinically significant antibodies (23 from Rh system (2 anti-C, 2 anti-D, 12 anti-E, 7 anti-c, 4 anti-K, 3 anti-Fya, 7 anti-Jka, 2 anti-S; 3 8 with usually not significant antibodies (6 anti-M, 1 anti-A1, 1 anti- Cw; B 40 patients developed multiple antibodies: 1 all patients had at least one clinically significant antibody from various blood group system (44 Rh, 13 Kell, 7 Kidd, 7 MNSs (S, s; 2 3 patients had usually not significant antibodies (1 Lewis, 2 Lutheran; 3 3 patients occasionally had clinically significant antibody (3 anti- Yta; 4 3 patients had antibodies of unknown specificity (2 autoantibodies, 1alloantibody. Antibodies detected in the majority of patients (65-63.1% had a specificity of Rh and/or the Kell system. Conclusions. The main goal of pre-transfusion blood compatibility testing is to detect clinically significant antibodies. The provision of antigen negative blood units for those patients is a special challenge for blood establishments. Database with a sufficient number of typed blood donors can help to resolve this problem.

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

    Directory of Open Access Journals (Sweden)

    Marlitt Stech

    2015-01-01

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

  3. T-cell detection with monoclonal antibody T101 kits.

    OpenAIRE

    Pollack, S M; Cimino, E F; Robbins, D S; Hoffman, P M

    1986-01-01

    A solid-phase immunoadsorption procedure (Quantigen T&B cell kit; Bio-Rad Laboratories, Richmond, Calif.) employing monoclonal antibody T101 detected mean percentages of peripheral blood T cells comparable to those obtained by rosetting with sheep erythrocytes, while lower values were obtained with an indirect immunofluorescence procedure (Cytotag T&B cell kit; Hybritech, Inc., San Diego, Calif.) employing the same antibody. Therefore, T101 binding appears to be more easily detected by solid-...

  4. [Continuous perfusion culture hybridoma cells for production of monoclonal antibody].

    Science.gov (United States)

    Mi, Li; Li, Ling; Feng, Qiang; Yu, Xiao-Ling; Chen, Zhi-Nan

    2002-05-01

    Hybridoma cells were cultured by continuous perfusion in Fibra-Cel of 5L packed-bed bioreactor for 22 days in low serum or serum-free media. The corresponded amino acids were fed and serum concentration was decreased by analyzing glucose concentration, oxygen uptake rate, secretary antibody amount and amino acids concentration in culture supernatant. Comparing with continuous perfusion culture that amino acids were not fed, antibody amount of production was increased about 2-3 times. The inoculated cell density was 2.5 x 10(5) cells/mL, while the final cell density was 8.79 x 10(8) cells/mL. Antibody production was reached 295 mg/L/d at average level, and the highest level was reached 532 mg/L/d. These results provided a primary mode of enlarge culture for monoclonal antibody industralization. PMID:12192875

  5. Cell-targeting antibodies in immunity to Ebola.

    Science.gov (United States)

    Schmaljohn, Alan; Lewis, George K

    2016-06-01

    As the 2014-15 Ebola virus epidemic in West Africa evolved from emergency to lesson, developers of both vaccines and therapeutic antibodies were left with the puzzlement of what kinds of anti-Ebola antibodies are predictably desirable in treating the afflicted, and what antibodies might account for the specific and lasting protection elicited by the more effective vaccines. The facile answer in virology is that neutralizing antibody (NAb) is desired and required. However, with Ebola and other filoviruses (as with many prior viral examples), there are multiple discordances in which neutralizing antibodies fail to protect animals, and others in which antibody-mediated protection is observed in the absence of measured virus neutralization. Explanation presumably resides in the protective role of antibodies that bind and functionally 'target' virus-infected cells, here called 'cell-targeting antibody', or CTAb. To be clear, many NAbs are also CTAbs, and in the case of Ebola the great majority of NAbs are likely CTAbs. Isotype, glycosylation, and other features of CTAbs are likely crucial in their capacity to mediate protection. Overall, results and analysis invite an increasingly complex view of antibody-mediated immunity to enveloped viruses. PMID:27005312

  6. ANTIBODIES DEFINING RAT ENDOTHELIAL-CELLS - RECA-1, A PAN-ENDOTHELIAL CELL-SPECIFIC MONOCLONAL-ANTIBODY

    NARCIS (Netherlands)

    DUIJVESTIJN, AM; VANGOOR, H; KLATTER, F; MAJOOR, GD; VANBUSSEL, E; VRIESMAN, PJCV

    1992-01-01

    We have been searching for antibodies reactive with rat endothelial cells. Two monoclonal antibodies (mAb), named RECA-1 and RECA-2 were produced and tested in immunoperoxidase staining on frozen sections of various rat tissues. Staining patterns were compared to those obtained with the mAbs OX-2, O

  7. Adhesion between peptides/antibodies and breast cancer cells

    Science.gov (United States)

    Meng, J.; Paetzell, E.; Bogorad, A.; Soboyejo, W. O.

    2010-06-01

    Atomic force microscopy (AFM) techniques were used to measure the adhesion forces between the receptors on breast cancer cells specific to human luteinizing hormone-releasing hormone (LHRH) peptides and antibodies specific to the EphA2 receptor. The adhesion forces between LHRH-coated AFM tips and human MDA-MB-231 cells (breast cancer cells) were shown to be about five times greater than those between LHRH-coated AFM tips and normal Hs578Bst breast cells. Similarly, those between EphA2 antibody-coated AFM tips and breast cancer cells were over five times greater than those between EphA2 antibody-coated AFM tips and normal breast cells. The results suggest that AFM can be used for the detection of breast cancer cells in biopsies. The implications of the results are also discussed for the early detection and localized treatment of cancer.

  8. Anti-B cell antibody therapies for inflammatory rheumatic diseases

    DEFF Research Database (Denmark)

    Faurschou, Mikkel; Jayne, David R W

    2014-01-01

    Several monoclonal antibodies targeting B cells have been tested as therapeutics for inflammatory rheumatic diseases. We review important observations from randomized clinical trials regarding the efficacy and safety of anti-B cell antibody-based therapies for rheumatoid arthritis, systemic lupus...... erythematosus, antineutrophil cytoplasmic antibody-associated vasculitis, polymyositis/dermatomyositis, and primary Sjögren's syndrome. For some anti-B cell agents, clinical benefits have been convincingly demonstrated, while other B cell-targeted therapies failed to improve outcomes when added to standard......-of-care treatment or were associated with increased rates of adverse events. Although the risk-benefit balance seems to be acceptable for currently licensed anti-B cell agents, additional studies are required to fully assess the safety of treatment regimens involving prolonged interference with B cell counts and...

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    1981-01-01

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

  11. Antibody and B cell responses to Plasmodium sporozoites

    Directory of Open Access Journals (Sweden)

    Johanna N Dups

    2014-11-01

    Full Text Available Antibodies are capable of blocking infection of the liver by Plasmodium sporozoites. Accordingly the induction of anti-sporozoite antibodies is a major aim of various vaccine approaches to malaria. In recent years our knowledge of the specificity and quantities of antibodies required for protection has been greatly expanded by clinical trials of various whole sporozoite and subunit vaccines. Moreover, the development of humanized mouse models and transgenic parasites have also aided our ability to assess the specificity of antibodies and their ability to block infection. Nonetheless, considerable gaps remain in our knowledge - in particular in understanding what antigens are recognized by infection blocking antibodies and in knowing how we can induce robust, long-lived antibody responses. Maintaining high levels of circulating antibodies is likely to be of primary importance, as antibodies must block infection in the short time it takes for sporozoites to reach the liver from the skin. It is clear that a better understanding of the development of protective B cell-mediated immunity will aid the development and refinement of malaria vaccines.

  12. Antibody

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2015-11-01

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

  14. Transfusion management of patients with red blood cell antibodies

    OpenAIRE

    Bujandrić Nevenka B.; Grujić Jasmina N.; Krga-Milanović Mirjana M.

    2013-01-01

    Introduction. Red blood cell antibodies may cause a positive result of pre-transfusion blood compatibility testing (crossmatch test). It can be a problem to provide suitable blood units for patients with clinically significant antibodies to high-frequency antigens as well as for those with multiple alloantibody specificities. This study was aimed at identifying transfused patients in the population of South-Backa who had developed clinically significant red...

  15. Multifactorial aspects of antibody-mediated blood cell destruction

    NARCIS (Netherlands)

    R. Kapur

    2014-01-01

    The research described in this thesis focuses on diseases of antibody-mediated blood cell destruction via FcγRs on phagocytes, in particular regarding platelets in fetal or neonatal alloimmune thrombocytopenia (FNAIT) and red blood cells (RBC) in hemolytic disease of the fetus and newborn (HDFN). Di

  16. Immunoglobulins, antibody repertoire and B cell development.

    Science.gov (United States)

    Butler, J E; Zhao, Y; Sinkora, M; Wertz, N; Kacskovics, I

    2009-03-01

    Swine share with most placental mammals the same five antibody isotypes and same two light chain types. Loci encoding lambda, kappa and Ig heavy chains appear to be organized as they are in other mammals. Swine differ from rodents and primates, but are similar to rabbits in using a single VH family (VH3) to encode their variable heavy chain domain, but not the family used by cattle, another artiodactyl. Distinct from other hoofed mammals and rodents, Ckappa:Clambda usage resembles the 1:1 ratio seen in primates. Since IgG subclasses diversified after speciation, same name subclass homologs do not exist among swine and other mammals unless very closely related. Swine possess six putative IgG subclasses that appear to have diversified by gene duplication and exon shuffle while retaining motifs that can bind to FcgammaRs, FcRn, C1q, protein A and protein G. The epithelial chorial placenta of swine and the precosial nature of their offspring have made piglets excellent models for studies on fetal antibody repertoire development and on the postnatal role of gut colonization, maternal colostrum and neonatal infection on the development of adaptive immunity during the "critical window" of immunological development. This chapter traces the study of the humoral immune system of this species through its various eras of discovery and compiles the results in tables and figures that should be a useful reference for educators and investigators. PMID:18804488

  17. Isolation of human monoclonal antibodies from peripheral blood B cells.

    Science.gov (United States)

    Huang, Jinghe; Doria-Rose, Nicole A; Longo, Nancy S; Laub, Leo; Lin, Chien-Li; Turk, Ellen; Kang, Byong H; Migueles, Stephen A; Bailer, Robert T; Mascola, John R; Connors, Mark

    2013-10-01

    Isolation of monoclonal antibodies is an important technique for understanding the specificities and characteristics of antibodies that underlie the humoral immune response to a given antigen. Here we describe a technique for isolating monoclonal antibodies from human peripheral blood mononuclear cells. The protocol includes strategies for the isolation of switch-memory B cells from peripheral blood, the culture of B cells, the removal of the supernatant for screening and the lysis of B cells in preparation for immunoglobulin heavy-chain and light-chain amplification and cloning. We have observed that the addition of cytokines IL-2, IL-21 and irradiated 3T3-msCD40L feeder cells can successfully stimulate switch-memory B cells to produce high concentrations of IgG in the supernatant. The supernatant may then be screened by appropriate assays for binding or for other functions. This protocol can be completed in 2 weeks. It is adaptable to use in other species and enables the efficient isolation of antibodies with a desired functional characteristic without prior knowledge of specificity. PMID:24030440

  18. Semiquantitative determination of circulating islet cell surface antibodies in diabetes

    International Nuclear Information System (INIS)

    Circulating pancreatic islet cell antibodies have been demonstrated in patients with insulin-dependent diabetes (IDD). The islet cell surface antibodies (ICSA) were determined by an indirect immunofluorescence test using a suspension of viable islet cells, and similar cytoplasmic antibodies which require the use of group O human pancreas were also found in the serum of some patients. A strong association exists between the presence of islet cell antibodies and the onset of insulin-dependent diabetes. The quantitative determination of circulating ICSA using 125I-protein A, which binds to IgG attached to the islet cell surface, was essentially as described by Lernmark et al. In the present study, we determined the circulating ICSA in diabetes, especially in IDD. The ICSA were estimated in various sera from both indirect immunofluorescence and 125I-protein A. Controls bound 125I-protein A. Sera from 4 IDD patients with circulating ICSA demonstrated by immunofluorescence showed >3,000 cpm 125I-protein A binding activity, and that from 5 patients without ICSA bound <2,000 cpm. Sera from newly-diagnosed diabetics who had severe hyperglycemia showed <2,000 cpm, with or without ICSA. (author)

  19. The lipopeptide 6-2 produced by Bacillus amyloliquefaciens anti-CA has potent activity against the biofilm-forming organisms.

    Science.gov (United States)

    Song, Bo; Wang, Yu-Zhen; Wang, Guang-Yuan; Liu, Guang-Lei; Li, Wan-Zhong; Yan, Fang

    2016-07-15

    Both the whole cells and protoplasts of Pseudomonas aeruginosa PAO1 and Bacillus cereus, two biofilm-forming bacteria, were disrupted by the lipopeptide 6-2 produced by Bacillus amyloliquefaciens anti-CA. The lipopeptide 6-2 could also effectively inhibit the formation of biofilms and disperse pre-formed biofilms. Live/dead staining of the biofilms grown in the absence or presence of the lipopeptide 6-2 showed that more dead bacterial cells in the presence of the lipopeptide than those in the absence of the lipopeptide and biofilm formation was greatly reduced by the lipopeptide 6-2. Expression of the PslC gene related to exopolysaccharides in P. aeruginosa PAO1 was also inhibited. All these results demonstrated that the lipopeptide 6-2 produced by B. amyloliquefaciens anti-CA had a high activity against biofilm-forming bacteria. The lipopeptide 6-2 also killed the larvae of Balanus amphitrite and inhibit the germination of Laminaria japonica spore and growth of protozoa, all of which were the fouling organisms in marine environments. PMID:27184127

  20. Multifactorial aspects of antibody-mediated blood cell destruction

    OpenAIRE

    Schoot, van der, B.H.; Vidarsson, G.; Kapur, R.

    2014-01-01

    The research described in this thesis focuses on diseases of antibody-mediated blood cell destruction via FcγRs on phagocytes, in particular regarding platelets in fetal or neonatal alloimmune thrombocytopenia (FNAIT) and red blood cells (RBC) in hemolytic disease of the fetus and newborn (HDFN). Diagnostically, for HDFN laboratory tests are in place in order to predict risk for severe fetal RBC destruction and thereby initiate appropriate treatments. This test is sensitive, but has relativel...

  1. Antibody-dependent cell-mediated cytotoxicity (ADCC) toward human O+ red cells coated with anti-D antibody: comparison between lymphocyte and monocyte ADCC activity.

    OpenAIRE

    Sunada,Mitsutoshi; Suzuki, Shinya; Ota, Zensuke

    1985-01-01

    We investigated the antibody dependent cell-mediated cytotoxicity (ADCC) of lymphocytes and monocytes toward human O+ red cells coated with anti-D antibody using a 51Cr release assay. Lysis of sensitized red cells by lymphocytes occurred rapidly, but monocyte-mediated lysis occurred slowly. This difference might be due to postphagocytic 51Cr release by monocytes. ADCC of lymphocytes increased in proportion to the effector cell number, but large amounts of antibodies were required. In contrast...

  2. Integrin receptors on tumor cells facilitate NK cell-mediated antibody-dependent cytotoxicity.

    Science.gov (United States)

    Anikeeva, Nadia; Steblyanko, Maria; Fayngerts, Svetlana; Kopylova, Natalya; Marshall, Deborah J; Powers, Gordon D; Sato, Takami; Campbell, Kerry S; Sykulev, Yuri

    2014-08-01

    NK cells that mediate ADCC play an important role in tumor-specific immunity. We have examined factors limiting specific lysis of tumor cells by CD16.NK-92 cells induced by CNTO 95LF antibodies recognizing αV integrins that are overexpressed on many tumor cells. Although all tested tumor cells were killed by CD16.NK-92 effectors in the presence of the antibodies, the killing of target cells with a low level of ICAM-1 expression revealed a dramatic decrease in their specific lysis at high antibody concentration, revealing a dose limiting effect. A similar effect was also observed with primary human NK cells. The effect was erased after IFN-γ treatment of tumor cells resulting in upregulation of ICAM-1. Furthermore, killing of the same tumor cells induced by Herceptin antibody was significantly impaired in the presence of CNTO 95Ala-Ala antibody variant that blocks αV integrins but is incapable of binding to CD16. These data suggest that αV integrins on tumor cells could compensate for the loss of ICAM-1 molecules, thereby facilitating ADCC by NK cells. Thus, NK cells could exercise cytolytic activity against ICAM-1 deficient tumor cells in the absence of proinflammatory cytokines, emphasizing the importance of NK cells in tumor-specific immunity at early stages of cancer. PMID:24810893

  3. Target cell specific antibody-based photosensitizers for photodynamic therapy

    Science.gov (United States)

    Rosenblum, Lauren T.; Mitsunaga, Makoto; Kakareka, John W.; Morgan, Nicole Y.; Pohida, Thomas J.; Choyke, Peter L.; Kobayashi, Hisataka

    2011-03-01

    In photodynamic therapy (PDT), localized monochromatic light is used to activate targeted photosensitizers (PS) to induce cellular damage through the generation of cytotoxic species such as singlet oxygen. While first-generation PS passively targeted malignancies, a variety of targeting mechanisms have since been studied, including specifically activatable agents. Antibody internalization has previously been employed as a fluorescence activation system and could potentially enable similar activation of PS. TAMRA, Rhodamine-B and Rhodamine-6G were conjugated to trastuzumab (brand name Herceptin), a humanized monoclonal antibody with specificity for the human epidermal growth factor receptor 2 (HER2), to create quenched PS (Tra-TAM, Tra-RhoB, and Tra-Rho6G). Specific PDT with Tra-TAM and Tra-Rho6G, which formed covalently bound H-dimers, was demonstrated in HER2+ cells: Minimal cell death (SDS-PAGE).

  4. Natural antibodies sustain differentiation and maturation of human dendritic cells

    OpenAIRE

    Bayry, Jagadeesh; Lacroix-Desmazes, Sébastien; Donkova-Petrini, Vladimira; Carbonneil, Cédric; Misra, Namita; Lepelletier, Yves; Delignat, Sandrine; Varambally, Sooryanarayana; Oksenhendler, Eric; Lévy, Yves; Debré, Marianne; Kazatchkine, Michel D.; Hermine, Olivier; Kaveri, Srini V.

    2004-01-01

    The differentiation and maturation of dendritic cells (DCs) is governed by various signals in the microenvironment. Monocytes and DCs circulate in peripheral blood, which contains high levels of natural antibodies (NAbs). NAbs are germ-line-encoded and occur in the absence of deliberate immunization or microbial aggression. To assess the importance of NAbs in the milieu on DC development, we examined the status of DCs in patients with X-linked agammaglobulinemia, a disease characterized by pa...

  5. A novel antibody discovery platform identifies anti-influenza A broadly neutralizing antibodies from human memory B cells.

    Science.gov (United States)

    Xiao, Xiaodong; Chen, Yan; Varkey, Reena; Kallewaard, Nicole; Koksal, Adem C; Zhu, Qing; Wu, Herren; Chowdhury, Partha S; Dall'Acqua, William F

    2016-07-01

    Monoclonal antibody isolation directly from circulating human B cells is a powerful tool to delineate humoral responses to pathological conditions and discover antibody therapeutics. We have developed a platform aimed at improving the efficiencies of B cell selection and V gene recovery. Here, memory B cells are activated and amplified using Epstein-Barr virus infection, co-cultured with CHO-muCD40L cells, and then assessed by functional screenings. An in vitro transcription and translation (IVTT) approach was used to analyze variable (V) genes recovered from each B cell sample and identify the relevant heavy/light chain pair(s). We achieved efficient amplification and activation of memory B cells, and eliminated the need to: 1) seed B cells at clonal level (≤1 cell/well) or perform limited dilution cloning; 2) immortalize B cells; or 3) assemble V genes into an IgG expression vector to confirm the relevant heavy/light chain pairing. Cross-reactive antibodies targeting a conserved epitope on influenza A hemagglutinin were successfully isolated from a healthy donor. In-depth analysis of the isolated antibodies suggested their potential uses as anti-influenza A antibody therapeutics and uncovered a distinct affinity maturation pathway. Importantly, our results showed that cognate heavy/light chain pairings contributed to both the expression level and binding abilities of our newly isolated VH1-69 family, influenza A neutralizing antibodies, contrasting with previous observations that light chains do not significantly contribute to the function of this group of antibodies. Our results further suggest the potential use of the IVTT as a powerful antibody developability assessment tool. PMID:27049174

  6. Integrin Receptors on Tumor Cells Facilitate NK cell-mediated Antibody-dependent Cytotoxicity

    OpenAIRE

    Anikeeva, Nadia; Steblyanko, Maria; Fayngerts, Svetlana; Kopylova, Natalya; Marshall, Deborah J.; Powers, Gordon D.; Sato, Takami; Campbell, Kerry S.; Sykulev, Yuri

    2014-01-01

    NK cells that mediate ADCC play an important role in tumor-specific immunity. We have examined factors limiting specific lysis of tumor cells by CD16.NK-92 cells induced by CNTO 95LF antibodies recognizing αV integrins that are overexpressed on many tumor cells. Although all tested tumor cells were killed by CD16.NK-92 effectors in the presence of the antibodies, the killing of target cells with a low level of ICAM-1 expression revealed a dramatic decrease in their specific lysis at high anti...

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

    Directory of Open Access Journals (Sweden)

    Sung Sun Yim

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

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

    Science.gov (United States)

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

    2013-09-01

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

  9. Detection and specificity of antibodies secreted by spleen cells in mice immunized with Streptococcus mutans.

    OpenAIRE

    Russell, M. W.; Czerkinsky, C; Moldoveanu, Z

    1986-01-01

    Immune responses of mice to Streptococcus mutans serotype c were analyzed by means of the enzyme-linked immunospot assay to determine the predominant specificities of the antibodies developed. In general, the numbers of splenic antibody-secreting cells correlated with serum antibody levels. A low dose (10(8) CFU) of killed whole cells injected twice intraperitoneally induced antibodies mainly against surface protein antigen I/II. A higher dose (10(9) CFU) given two to six times also resulted ...

  10. Delivery of anticancer drugs and antibodies into cells using ultrasound

    Science.gov (United States)

    Wu, Junru; Pepe, Jason; Rincon, Mercedes

    2005-04-01

    It has been shown experimentally in cell suspensions that pulsed ultrasound (2.0 MHz) could be used to deliver an anti-cancer drug (Adriamycin hydrochloride) into Jurkat lymphocytes and antibodies (goat anti rabbit IgG and anti mouse IgD) into human peripheral blood mononuclear (PBMC) cells and Jurkat lymphocytes assisted by encapsulated microbubbles (Optison). When Adriamycin hydrochloride (ADR) was delivered, the delivery efficiency reached 4.80% and control baseline (no ultrasound and no ADR) was 0.17%. When anti-rabbit IgD was delivered, the efficiencies were 34.90% (control baseline was 1.33%) and 32.50% (control baseline was 1.66%) respectively for Jurkat cells and PBMC. When goat anti rabbit IgG was delivered, the efficiencies were 78.60% (control baseline was 1.60%) and 57.50% (control baseline was 11.30%) respectively for Jurkat cells and PBMC.

  11. MONOCLONAL-ANTIBODIES TO HUMAN EMBRYONAL CARCINOMA-CELLS - ANTIGENIC RELATIONSHIPS OF GERM-CELL TUMORS

    NARCIS (Netherlands)

    DEWIT, TFR; WILSON, L; VANDENELSEN, PJ; THIELEN, F; BREKHOFF, D; OOSTERHUIS, JW; PERA, MF; STERN, PL

    1991-01-01

    Fifteen monoclonal antibodies (mAb) that show specificity for human embryonal carcinoma cells are described. C57BL/6 mice were immunized with Tera-2 embryonal carcinoma cells, and hybridomas were isolated and tested versus a set of human developmental tumor cell lines. The antigens exhibit relativel

  12. How antibodies alter the cell entry pathway of dengue virus particles in macrophages

    Science.gov (United States)

    Ayala-Nunez, Nilda V.; Hoornweg, Tabitha E.; van de Pol, Denise P.I.; Sjollema, Klaas A.; Flipse, Jacky; van der Schaar, Hilde M.; Smit, Jolanda M.

    2016-01-01

    Antibody-dependent enhancement of dengue virus (DENV) infection plays an important role in the exacerbation of DENV-induced disease. To understand how antibodies influence the fate of DENV particles, we explored the cell entry pathway of DENV in the absence and presence of antibodies in macrophage-like P388D1 cells. Recent studies unraveled that both mature and immature DENV particles contribute to ADE, hence, both particles were studied. We observed that antibody-opsonized DENV enters P388D1 cells through a different pathway than non-opsonized DENV. Antibody-mediated DENV entry was dependent on FcγRs, pH, Eps15, dynamin, actin, PI3K, Rab5, and Rab7. In the absence of antibodies, DENV cell entry was FcγR, PI3K, and Rab5-independent. Live-cell imaging of fluorescently-labeled particles revealed that actin-mediated membrane protrusions facilitate virus uptake. In fact, actin protrusions were found to actively search and capture antibody-bound virus particles distantly located from the cell body, a phenomenon that is not observed in the absence of antibodies. Overall, similar results were seen for antibody-opsonized standard and antibody-bound immature DENV preparations, indicating that the maturation status of the virus does not control the entry pathway. Collectively, our findings suggest that antibodies alter the cell entry pathway of DENV and trigger a novel mechanism of initial virus-cell contact. PMID:27385443

  13. High level transient production of recombinant antibodies and antibody fusion proteins in HEK293 cells

    OpenAIRE

    Jäger, Volker; Büssow, Konrad; Wagner, Andreas; Weber, Susanne; Hust, Michael; Frenzel, André; Schirrmann, Thomas

    2013-01-01

    Background The demand of monospecific high affinity binding reagents, particularly monoclonal antibodies, has been steadily increasing over the last years. Enhanced throughput of antibody generation has been addressed by optimizing in vitro selection using phage display which moved the major bottleneck to the production and purification of recombinant antibodies in an end-user friendly format. Single chain (sc)Fv antibody fragments require additional tags for detection and are not as suitable...

  14. Isolation of additional monoclonal antibodies directed against cell surface antigens of Myxococcus xanthus cells undergoing submerged development.

    OpenAIRE

    Gill, J.S.; Dworkin, M

    1988-01-01

    Thirteen additional monoclonal antibodies directed against cell surface antigens of Myxococcus xanthus cells undergoing submerged development were isolated and partially characterized. As measured by quantitative enzyme-linked immunosorbent assay, 10 of these antibodies recognized antigens common to both vegetatively growing cells and cells undergoing submerged development; 3 antibodies recognized antigens specific to developing cells. Five antigens were revealed as single bands on Western bl...

  15. Staining of Langerhans cells with monoclonal antibodies to macrophages and lymphoid cells.

    OpenAIRE

    Haines, K A; Flotte, T. J.; Springer, T A; Gigli, I; Thorbecke, G. J.

    1983-01-01

    Langerhans cells are Ia-bearing antigen-presenting cells in the epidermis that share many functions with macrophages. We have used monoclonal antibodies to the macrophage antigens, Mac-2 and-3, Ia antigen, Fc fragment receptor and the common leukocyte antigen CLA to compare the cell surface antigens of these cells with those of interdigitating and follicular dendritic cells and of macrophages in lymphoid tissues. Immunoperoxidase staining was carried out with epidermal sheets from BALB/c mice...

  16. TIM-1 signaling in B cells regulates antibody production

    International Nuclear Information System (INIS)

    Highlights: → TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. → Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. → TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3+ anti-CD28-stimulated CD4+ T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.

  17. Immunosuppressive T-cell antibody induction for heart transplant recipients

    DEFF Research Database (Denmark)

    Penninga, Luit; Møller, Christian H; Gustafsson, Finn;

    2013-01-01

    Heart transplantation has become a valuable and well-accepted treatment option for end-stage heart failure. Rejection of the transplanted heart by the recipient's body is a risk to the success of the procedure, and life-long immunosuppression is necessary to avoid this. Clear evidence is required...... to identify the best, safest and most effective immunosuppressive treatment strategy for heart transplant recipients. To date, there is no consensus on the use of immunosuppressive antibodies against T-cells for induction after heart transplantation....

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

    Directory of Open Access Journals (Sweden)

    Urs B Hagemann

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

  19. Cell line profiling to improve monoclonal antibody production.

    Science.gov (United States)

    Kang, Sohye; Ren, Da; Xiao, Gang; Daris, Kristi; Buck, Lynette; Enyenihi, Atim A; Zubarev, Roman; Bondarenko, Pavel V; Deshpande, Rohini

    2014-04-01

    Mammalian cell culture performance is influenced by both intrinsic (genetic) and extrinsic (media and process) factors. In this study, intrinsic capacity of various monoclonal antibody-producing Chinese Hamster Ovary (CHO) cell lines was compared by exposing them to the same culture condition. Microarray-based transcriptomics and LC-MS/MS shotgun proteomics technologies were utilized to obtain expression landscape of different cell lines. Specific transcripts and proteins correlating with productivity, growth rate and cell size have been identified. The proteomics analysis results showed a strong correlation between the intracellular protein expression levels of the recombinant DHFR and productivity. In contrast, neither the light chain nor the heavy chain of the recombinant monoclonal antibody showed correlation to productivity. Other top ranked proteins which demonstrated positive correlation to productivity included the adaptor protein complex subunits AP3D1and AP2B2, DNA repair protein DDB1 and the ER translocation complex component, SRPR. The subunits of molecular chaperone T-complex protein 1 and the regulator of mitochondrial one-carbon metabolism MTHFD2 showed negative correlation to productivity. The transcriptomics analysis has identified the regulators of calcium signaling, Tmem20 and Rcan1, as the top ranked genes displaying positive and negative correlation to productivity, respectively. For the second part of the study, the principal component analysis (PCA) was generated to view the underlying global structure of the expression data. A clear division and expression polarity was observed between the two distinct clusters of cell lines, independent of link to productivity or any other traits examined. The primary component of the PCA generated from either transcriptomics or proteomics data displayed a strong correlation to cell size and doubling time, while none of the main principal components showed correlation to productivity. Our findings suggest

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

    OpenAIRE

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

    1991-01-01

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

  1. Production of Antibodies against Multipass Membrane Proteins Expressed in Human Tumor Cells Using Dendritic Cell Immunization

    OpenAIRE

    Takahiko Tamura; Joe Chiba

    2009-01-01

    Antibody mediated therapeutic strategies against human malignant tumors have been widely authorized and clinically applied to cancer patients. In order to develop methods to generate antibodies reactive to the extracellular domains of multipass plasma membrane proteins specifically expressed in malignant tumors, we examined the use of dendritic cells (DCs) for immunization. DCs were transduced with genes encoding the human six transmembrane epithelial antigen of prostate 1 (STEAP1), STEAP4, a...

  2. Effects of Supplementation of Various Medium Components on Chinese Hamster Ovary Cell Cultures Producing Recombinant Antibody

    OpenAIRE

    Kim, Do Yun; Lee, Joon Chul; Chang, Ho Nam; Oh, Duk Jae

    2005-01-01

    Thirteen vitamins, twenty amino acids, hormones, inorganic salts, and other chemical agents, which constitute typical serum-free media, were evaluated for the development of fortified medium to enhance cell growth and productivity of recombinant antibody in the cultures of the recombinant Chinese hamster ovary (rCHO) cells. Two different rCHO cell lines, rCHO-A producing recombinant antibodies against the human platelet and rCHO-B secreting recombinant antibodies against the S surface antigen...

  3. Method of rapid production of hybridomas expressing monoclonal antibodies on the cell surface

    Science.gov (United States)

    Meagher, Richard B.; Laterza, Vince

    2006-12-12

    The present invention relates to genetically altered hybridomas, myelomas and B cells. The invention also relates to utilizing genetically altered hybridomas, myelomas and B cells in methods of making monoclonal antibodies. The present invention also provides populations of hybridomas and B cells that can be utilized to make a monoclonal antibody of interest.

  4. Chimeric mouse-human IgG1 antibody that can mediate lysis of cancer cells

    International Nuclear Information System (INIS)

    A chimeric mouse-human antibody has been created that recognizes an antigen found on the surface of cells from many carcinomas. Immunoglobulin constant (C) domains of the mouse monoclonal antibody L6, C/sub γ2a/ and C/sub kappa/, were substituted by the human C/sub γ1/ and C/sub kappa/ by recombining cDNA modules encoding variable or C domains. The cDNA constructs were transfected into lymphoid cells for antibody production. The chimeric antibody and mouse L6 antibody bound to carcinoma cells with equal affinity and mediated complement-dependent cytolysis. In the presence of human effector cells, the chimeric antibody gave antibody-dependent cellular cytotoxicity at 100 times lower concentration than that needed for the mouse L6 antibody. The assay for lysis was carried out with 51Cr-labeled target calls. The chimeric antibody, but not the mouse L6 antibody, is effective against a melanoma line expressing small amounts of the L6 antigen. The findings point to the usefulness of the chimeric antibody approach for obtaining agents with strong antitumor activity for possible therapeutic use in man

  5. Lineage tracing of human B cells reveals the in vivo landscape of human antibody class switching.

    Science.gov (United States)

    Horns, Felix; Vollmers, Christopher; Croote, Derek; Mackey, Sally F; Swan, Gary E; Dekker, Cornelia L; Davis, Mark M; Quake, Stephen R

    2016-01-01

    Antibody class switching is a feature of the adaptive immune system which enables diversification of the effector properties of antibodies. Even though class switching is essential for mounting a protective response to pathogens, the in vivo patterns and lineage characteristics of antibody class switching have remained uncharacterized in living humans. Here we comprehensively measured the landscape of antibody class switching in human adult twins using antibody repertoire sequencing. The map identifies how antibodies of every class are created and delineates a two-tiered hierarchy of class switch pathways. Using somatic hypermutations as a molecular clock, we discovered that closely related B cells often switch to the same class, but lose coherence as somatic mutations accumulate. Such correlations between closely related cells exist when purified B cells class switch in vitro, suggesting that class switch recombination is directed toward specific isotypes by a cell-autonomous imprinted state. PMID:27481325

  6. Microselection - Affinity Selecting Antibodies against a Single Rare Cell in a Heterogeneous Population

    DEFF Research Database (Denmark)

    Sørensen, Morten Draeby; Agerholm, Inge Errebo; Christensen, Britta; Kølvraa, Steen; Kristensen, Peter

    2010-01-01

    antibodies. Here we have generated a microselection method allowing antibody selection, by phage display, targeting a single cell in a heterogeneous population. One K562 cell (female origin) was positioned on glass-slide among millions of lymphocytes from male donor, identifying the K562 cell by FISH (XX......). Several single cell selections were performed on such individual slides. The phage particles bound to the target cell is protected by a minute disc, while inactivating all remaining phage by UV-irradiation; leaving only the phage bound to the target cell viable. We hereby retrieved up to eight antibodies...

  7. Radionuclide imaging of primary renal-cell carcinoma by I-131-labeled antitumor antibody

    International Nuclear Information System (INIS)

    A goat antibody against human renal-cell carcinoma reacted on immunofluorescence with renal-cell carcinomas from 20 patients, but not with normal adult human tissues, including kidney. After i.v. administration the I-131-linked antibody showed preferential tumor localization in six of seven patients with primary renal carcinoma. Labeled antitumor antibodies may have the specificity for tumor imaging that current radiopharmaceuticals lack

  8. Antibody-protein A conjugated quantum dots for multiplexed imaging of surface receptors in living cells.

    Science.gov (United States)

    Jin, Takashi; Tiwari, Dhermendra K; Tanaka, Shin-Ichi; Inouye, Yasushi; Yoshizawa, Keiko; Watanabe, Tomonobu M

    2010-11-01

    To use quantum dots (QDs) as fluorescent probes for receptor imaging, QD surface should be modified with biomolecules such as antibodies, peptides, carbohydrates, and small-molecule ligands for receptors. Among these QDs, antibody conjugated QDs are the most promising fluorescent probes. There are many kinds of coupling reactions that can be used for preparing antibody conjugated QDs. Most of the antibody coupling reactions, however, are non-selective and time-consuming. In this paper, we report a facile method for preparing antibody conjugated QDs for surface receptor imaging. We used ProteinA as an adaptor protein for binding of antibody to QDs. By using ProteinA conjugated QDs, various types of antibodies are easily attached to the surface of the QDs via non-covalent binding between the F(c) (fragment crystallization) region of antibody and ProteinA. To show the utility of ProteinA conjugated QDs, HER2 (anti-human epidermal growth factor receptor 2) in KPL-4 human breast cancer cells were stained by using anti-HER2 antibody conjugated ProteinA-QDs. In addition, multiplexed imaging of HER2 and CXCR4 (chemokine receptor) in the KPL-4 cells was performed. The result showed that CXCR4 receptors coexist with HER2 receptors in the membrane surface of KPL-4 cells. ProteinA mediated antibody conjugation to QDs is very useful to prepare fluorescent probes for multiplexed imaging of surface receptors in living cells. PMID:20835432

  9. Method and cell lines for the production of monoclonal antibodies to human glycophorin A

    Science.gov (United States)

    Bigbee, W.L.; Fong, S.S.N.; Jensen, R.H.; Vanderlaan, M.

    Cloned mouse hybridoma cell lines have been established which continuously produce antibodies that differentiate between the M and N forms of human glycophorin A. These antibodies have potential application as human blood group reagents, as markers for terminally differentiated erythroid cells and as immunofluorescent labels of somatically variant human erythrocytes.

  10. Quantification of antibody production of individual hybridoma cells by Surface Plasmon Resonance imaging.

    NARCIS (Netherlands)

    Stojanovic, I.; Velden, van der T.J.G.; Mulder, H.W.; Schasfoort, R.B.M.; Terstappen, L.W.M.M.

    2015-01-01

    Surface plasmon resonance imaging (SPRi) is most frequently used for the label-free measurement of biomolecular interactions. Here we explore the potential of SPRi to measure antibody production of individual hybridoma cells. As a model system, cells from a hybridoma, producing monoclonal antibodies

  11. Targeting CD47-SIRPα interactions for potentiating therapeutic antibody-mediated tumor cell destruction by phagocytes

    OpenAIRE

    Zhao, X.W.

    2014-01-01

    The primary aim of the studies described in this thesis was to investigate the role of CD47-SIRPα interactions in therapeutic antibody-dependent tumor cell destruction by human phagocytes and also explore the killing mechanism(s) by which human phagocytes, and in particular human neutrophils, mediate therapeutic antibody-dependent cytotoxicity towards cancer cells.

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

    Science.gov (United States)

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

    1988-01-01

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

  13. Serological analysis of cell surface antigens of null cell acute lymphocytic leukemia by mouse monoclonal antibodies.

    OpenAIRE

    Ueda, R; Tanimoto, M; Takahashi, T.; Ogata, S; Nishida, K; Namikawa, R.; Nishizuka, Y; Ota, K.

    1982-01-01

    Nine antigens systems were defined. Two were related to HLA-A,B,C and to Ia-like antigens; the others could be grouped into three categories. (i) NL-22, NL-1: NL-22 antibody reacted with leukemia cells from 12 to 16 cases of null cell acute lymphocytic leukemia (null-ALL) but not with any other type of leukemia tested or with lymphoid cells of various origins. Among cultured cell lines tested, one (NALM-6) of three null-ALL cell lines was positive, the others were negative. Absorption analysi...

  14. Enhanced clearance of HIV-1-infected cells by broadly neutralizing antibodies against HIV-1 in vivo.

    Science.gov (United States)

    Lu, Ching-Lan; Murakowski, Dariusz K; Bournazos, Stylianos; Schoofs, Till; Sarkar, Debolina; Halper-Stromberg, Ariel; Horwitz, Joshua A; Nogueira, Lilian; Golijanin, Jovana; Gazumyan, Anna; Ravetch, Jeffrey V; Caskey, Marina; Chakraborty, Arup K; Nussenzweig, Michel C

    2016-05-20

    Antiretroviral drugs and antibodies limit HIV-1 infection by interfering with the viral life cycle. In addition, antibodies also have the potential to guide host immune effector cells to kill HIV-1-infected cells. Examination of the kinetics of HIV-1 suppression in infected individuals by passively administered 3BNC117, a broadly neutralizing antibody, suggested that the effects of the antibody are not limited to free viral clearance and blocking new infection but also include acceleration of infected cell clearance. Consistent with these observations, we find that broadly neutralizing antibodies can target CD4(+) T cells infected with patient viruses and can decrease their in vivo half-lives by a mechanism that requires Fcγ receptor engagement in a humanized mouse model. The results indicate that passive immunotherapy can accelerate elimination of HIV-1-infected cells. PMID:27199430

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

    Directory of Open Access Journals (Sweden)

    Ferenc A Scheeren

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

  16. Mimicking the germinal center reaction in hybridoma cells to isolate temperature-selective anti-PEG antibodies

    OpenAIRE

    Su, Yu-Cheng; Al-Qaisi, Talal S; Tung, Hsin-Yi; Cheng, Tian-Lu; Chuang, Kuo-Hsiang; Chen, Bing-Mae; Roffler, Steve R.

    2014-01-01

    Modification of antibody class and binding properties typically requires cloning of antibody genes, antibody library construction, phage or yeast display and recombinant antibody expression. Here, we describe an alternative “cloning-free” approach to generate antibodies with altered antigen-binding and heavy chain isotype by mimicking the germinal center reaction in antibody-secreting hybridoma cells. This was accomplished by lentiviral transduction and controllable expression of activation-i...

  17. Rapid antibody responses by low-dose, single-step, dendritic cell-targeted immunization

    OpenAIRE

    Wang, Hui; Griffiths, Michelle N.; Burton, Dennis R; Ghazal, Peter

    2000-01-01

    We have compared the kinetics of antibody responses in conventional and dendritic cell-targeted immunization by using a model antigen in mice. Targeting was achieved by linking the reporter antigen (polyclonal goat anti-hamster antibody) to N418, a hamster mAb that binds to the CD11c molecule on the surface of murine dendritic cells. Intradermal injection of submicrogram quantities of goat anti-hamster antibody complexed to mAb N418 elicited goat antibody-specific serum IgG in mice. Antigen-s...

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

    OpenAIRE

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

    2013-01-01

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

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

    OpenAIRE

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

    1986-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Caroline Grönwall

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

  1. Targeting HIV-1 Envelope Glycoprotein Trimers to B Cells by Using APRIL Improves Antibody Responses

    OpenAIRE

    Melchers M; Bontjer I; Tong T; Chung NP; Klasse PJ; Eggink D; Montefiori DC; Gentile M; Cerutti A; Olson WC; Berkhout B; Binley JM; Moore JP; Sanders RW

    2012-01-01

    An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality of the antibodies raised against the viral envelope glycoprotein complex (Env). We hypothesized that targeting Env vaccines directly to B cells, by fusing them to molecules that bind and activate these cells, would improve Env-specific antibody responses. Therefore, we fused trimeric Env gp140 to A PRoliferation-Inducing Ligand (APRIL), B-cell Activating Factor (BAFF), and CD40 Ligand (CD40L). The...

  2. Microassay using radioiodinated protein A from Staphylococcus aureus for antibodies bound to cell surface antigens of adherent tumor cells

    International Nuclear Information System (INIS)

    A new microassay which utilizes radioiodinated staphylococcal protein A (SpA) to detect antibodies bound to cell surface antigens (CSA) was developed for monolayers of viable cultured tumor cells. Optimal detection of bound antibodies occurred at 37degC with incubation periods of one hour each for antiserum and 131I-SpA. Labelling target cells with 125I-iododeoxyuridine facilitated expression of results relative to tumor cell number or protein concentration. Quantitation of antibody depended on CSA (tumor cells) and 131I-SpA being in excess of antibody; under these conditions, 0.25 ng of cell surface bound antibody could be detected readily. Initial studies utilized cultured human neuroblastoma and lung adenocarcinoma cells and human and rabbit antisera. Some antibodies in human serum which bound to CSA were removed by absorption with glutaraldehyde-insolubilized fetal calf serum (FSC) suggesting that FCS or FCS-like determinants can be CSA. Rabbit antisera, after extensive absorption, bound to cultured neuroblastoma and lung adenocarcinoma cells in a cell type specific pattern. These experiments demonstrated the value of this assay in quantitating anti-CSA antibodies and in serological analysis of tumor CSA

  3. Risk factors for the presence of non-rhesus D red blood cell antibodies in pregnancy

    NARCIS (Netherlands)

    J.M. Koelewijn; T.G.M. Vrijkotte; M. de Haas; C.E. van der Schoot; G.J. Bonsel

    2009-01-01

    To identify risk factors for the presence of non-rhesus D (RhD) red blood cell (RBC) antibodies in pregnancy. To generate evidence for subgroup RBC antibody screening and for primary prevention by extended matching of transfusions in women < 45 years. Case-control study. Nationwide evaluation of scr

  4. A rapid method for the detection of antibodies to cell surface antigens: a solid phase radioimmunoassay using cell membranes

    International Nuclear Information System (INIS)

    Cell membranes isolated from murine lymphocytes or ascites tumors bind tightly to the surface of flexible plastic microtiter plates in the absence of additional proteins. This allows the detection of membrane associated molecules by specific antibodies and thus forms the basis for a rapid and sensitive radioimmunoassay for antibodies to membrane-bound components. The assay compares favourably with a variety of methods currently used to detect antibodies to cell surface antigens. The assay detects a variety of well characterized murine cell surface antigens (H-2, I-A, T-200, Thy-1.2, Ig). The level of antibody binding to membranes on plates correlates well with antigen density on intact cells. A modification of the assay involving competition between cross-reacting antibodies allows detection and resolution of closely spaced antigenic determinants. (Auth.)

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

    International Nuclear Information System (INIS)

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

  6. C-C chemokine receptor-7 mediated endocytosis of antibody cargoes into intact cells

    Directory of Open Access Journals (Sweden)

    FrançoisMarceau

    2013-09-01

    Full Text Available The C-C chemokine receptor-7 (CCR7 is a G protein coupled receptor that has a role in leukocyte homing, but that is also expressed in aggressive tumor cells. Preclinical research supports that CCR7 is a valid target in oncology. In view of the increasing availability of therapeutic monoclonal antibodies that carry cytotoxic cargoes, we studied the feasibility of forcing intact cells to internalize known monoclonal antibodies by exploiting the cycle of endocytosis and recycling triggered by the CCR7 agonist CCL19. Firstly, an anti-CCR7 antibody (CD197; clone 150503 labeled surface recombinant CCR7 expressed in intact HEK 293a cells and the fluorescent antibody was internalized following CCL19 treatment. Secondly, a recombinant myc-tagged CCL19 construction was exploited along the anti-myc monoclonal antibody 4A6. The myc-tagged ligand was produced as a conditioned medium of transfected HEK 293a cells that contained the equivalent of 430 ng/ml of immunoreactive CCL19 (average value, ELISA determination. CCL19-myc, but not authentic CCL19, carried the fluorophore-labeled antibody 4A6 into other recipient cells that expressed recombinant CCR7 (microscopy, cytofluorometry. The immune complexes were apparent in endosomal structures, colocalized well with the small GTPase Rab5 and progressed toward Rab7-positive endosomes. A dominant negative form of Rab5 (GDP-locked inhibited this endocytosis. Further, endosomes in CCL19-myc- or CCL19-stimulated cells were positive for β-arrestin2, but rarely for β-arrestin1. Following treatment with CCL19-myc and the 4A6 antibody, the melanoma cell line A375 that expresses endogenous CCR7 was specifically stained using a secondary peroxidase-conjugated antibody. Agonist-stimulated CCR7 can transport antibody-based cargoes, with possible therapeutic applications in oncology.

  7. Access of protective antiviral antibody to neuronal tissues requires CD4 T-cell help.

    Science.gov (United States)

    Iijima, Norifumi; Iwasaki, Akiko

    2016-05-26

    Circulating antibodies can access most tissues to mediate surveillance and elimination of invading pathogens. Immunoprivileged tissues such as the brain and the peripheral nervous system are shielded from plasma proteins by the blood-brain barrier and blood-nerve barrier, respectively. Yet, circulating antibodies must somehow gain access to these tissues to mediate their antimicrobial functions. Here we examine the mechanism by which antibodies gain access to neuronal tissues to control infection. Using a mouse model of genital herpes infection, we demonstrate that both antibodies and CD4 T cells are required to protect the host after immunization at a distal site. We show that memory CD4 T cells migrate to the dorsal root ganglia and spinal cord in response to infection with herpes simplex virus type 2. Once inside these neuronal tissues, CD4 T cells secrete interferon-γ and mediate local increase in vascular permeability, enabling antibody access for viral control. A similar requirement for CD4 T cells for antibody access to the brain is observed after intranasal challenge with vesicular stomatitis virus. Our results reveal a previously unappreciated role of CD4 T cells in mobilizing antibodies to the peripheral sites of infection where they help to limit viral spread. PMID:27225131

  8. 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

    2015-09-01

    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. PMID:26333364

  9. Monoclonal antibodies to cell surface antigens of human melanoma

    International Nuclear Information System (INIS)

    The authors have worked with three human melanoma antigens which have been defined by monoclonal mouse antibodies: p97, a glycoprotein that is structurally related to transferrin, a proteoglycan, and a GD3 ganglioside that is slightly different from the GD3 of normal brain. All three antigens can be detected in frozen sections of melanoma, using immunohistological techniques. Antibodies and Fab fragments, specific for either p97 or the proteoglycan antigen, have been radiolabelled with 131I and successfully used for tumor imaging, and Phase I therapeutic trails are underway, using 131I-labelled Fab fragments, specific for p97 or the proteoglycan antigen, to localize a potentially therapeutic dose of radiation into tumors. It may be feasible to use the same monoclonal antibodies, or antibody fragments, as carriers of neutron capturers, such as boron, for possible use in tumor therapy. The initial experiments on this are best carried out by using nude mice (or rats) carrying human melanoma xenografts

  10. Docking of B-cell epitope antigen to specific hepatitis B antibody

    Indian Academy of Sciences (India)

    R Rajkannan; E J Padma Malar

    2007-09-01

    The interaction of pres1 region of hepatitis B virus B-cell epitope antigen with specific hepatitis B neutralizing monoclonal antibody was examined by docking study. We modelled the 3D complex structure of B-cell epitope antigen residues CTTPAQGNSMFPSCCCTKPTDGNCY by homology modelling and docked it with the crystal structure of monoclonal antibody specific for the pres1 region of the hepatitis B virus. At the optimized docked conformation, the interactions between the amino acids of antigen and antibody were examined. It is found that the docked complex is stabilized by 59.3 kcal/mol. The stability of the docked antigen-antibody complex is due to hydrogen bonding and van der Waals interactions. The amino acids of the antigen and antibody responsible for the interaction were identified.

  11. Identifying bottlenecks in transient and stable production of recombinant monoclonal-antibody sequence variants in Chinese hamster ovary cells

    OpenAIRE

    Mason, Megan; Sweeney, Bernadette; Cain, Katharine; Stephens, Paul; Sharfstein, Susan T.

    2012-01-01

    The increasing demand for antibody-based therapeutics has emphasized the need for technologies to improve recombinant antibody titers from mammalian cell lines. Moreover, as antibody therapeutics address an increasing spectrum of indications, interest has increased in antibody engineering to improve affinity and biological activity. However, the cellular mechanisms that dictate expression and the relationships between antibody sequence and expression level remain poorly understood. Fundamenta...

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

    Science.gov (United States)

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

    1981-05-01

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

  13. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production

    Science.gov (United States)

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A.; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C.; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten; Westendorf, Astrid M.; Häussinger, Dieter; Lang, Florian; Dittmer, Ulf; Küppers, Ralf; Recher, Mike; Hardt, Cornelia; Scheffrahn, Inka; Beauchemin, Nicole; Göthert, Joachim R.; Singer, Bernhard B.; Lang, Philipp A.; Lang, Karl S.

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1−/− mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1−/− mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. PMID:25692415

  14. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production.

    Science.gov (United States)

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten; Westendorf, Astrid M; Häussinger, Dieter; Lang, Florian; Dittmer, Ulf; Küppers, Ralf; Recher, Mike; Hardt, Cornelia; Scheffrahn, Inka; Beauchemin, Nicole; Göthert, Joachim R; Singer, Bernhard B; Lang, Philipp A; Lang, Karl S

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1(-/-) mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1(-/-) mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. PMID:25692415

  15. Studies on multiple thyroid cell membrane-directed antibodies in Graves' disease.

    OpenAIRE

    Zakarija, M; Garcia, A.; McKenzie, J. M.

    1985-01-01

    Immunoglobulin G was obtained from the serum of a woman who had given birth to three children with a delayed onset of hyperthyroidism; the clinical events were due to the coexistence of thyroid-stimulating antibody (TSAb) and an inhibitor of TSAb in the maternal serum. The current studies explore the possible existence of additional thyroid membrane-directed antibodies. Human thyroid slices, cells in monolayer culture, and functioning rat thyroid cells (FRTL5), with measurement of cyclic AMP ...

  16. SERUM ANTIBODIES TO WHOLE-CELL AND RECOMBINANT ANTIGENS OF BORRELIA BURGDORFERI IN COTTONTAIL RABBITS

    OpenAIRE

    Magnarelli, Louis A.; Norris, Steven J; Fikrig, Erol

    2012-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985–86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37...

  17. Rare Association of Anti-Hu Antibody Positive Paraneoplastic Neurological Syndrome and Transitional Cell Bladder Carcinoma

    OpenAIRE

    S. Lukacs; Szabo, N; Woodhams, S

    2012-01-01

    Introduction. Paraneoplastic encephalomyelitis (PEM) and subacute sensory neuronopathy (SSN) are remote effects of cancer, usually associated with small-cell lung carcinoma and positive anti-Hu antibody. We describe the rare association of bladder transitional cell carcinoma (TCC) with anti-Hu antibody positivity resulting in this paraneoplastic neurological syndrome. Patient. A 76-year-old female presented with bilateral muscle weakness and paraesthesia of the upper and lower limbs in a leng...

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  19. Poly(N-isopropylacrylamide)-graft-polypropylene membranes containing adsorbed antibody for cell separation.

    Science.gov (United States)

    Okamura, Aiko; Itayagoshi, Midori; Hagiwara, Taeko; Yamaguchi, Manae; Kanamori, Toshiyuki; Shinbo, Toshio; Wang, Pi-Chao

    2005-04-01

    We developed a novel selective cell-separation method based on using a poly(N-isopropylacrylamide)-graft-polypropylene (PNIPAAm-g-PP) membrane containing adsorbed monoclonal antibody specific to the target cell. This membrane was prepared by plasma-induced polymerization and soaking in an antibody solution at 37 degrees C. Poly(N-isopropylacrylamide) has a thermoresponsive phase transition: at 32 degrees C water-insoluble (hydrophobic) and water-soluble (hydrophilic) states interconvert. Adsorption of antibody onto PNIPAAm-g-PP membrane at 37 degrees C and its desorption at 4 degrees C was verified by fluorescence-microscopy of the PNIPAAm-g-PP membrane after soaking it in fluorescein-conjugated goat anti-mouse IgG in phosphate-buffered saline. PNIPAAm-g-PP membranes containing adsorbed anti-mouse CD80 monoclonal antibody preferentially captured mouse-CD80 transfected cells at 37 degrees C compared with membranes lacking antibody or containing anti-mouse CD86 monoclonal antibody. Detachment of captured cells from PNIPAAm-g-PP membranes was facilitated by washing at 4 degrees C because of the thermoresponsive phase transition of PNIPAAm. With this method, mouse CD80- or mouse CD86-transfected cells were enriched from a 1:1 cell suspension to 72% or 66%, simply and with high yield. PMID:15475058

  20. Efficient method to optimize antibodies using avian leukosis virus display and eukaryotic cells.

    Science.gov (United States)

    Yu, Changming; Pike, Gennett M; Rinkoski, Tommy A; Correia, Cristina; Kaufmann, Scott H; Federspiel, Mark J

    2015-08-11

    Antibody-based therapeutics have now had success in the clinic. The affinity and specificity of the antibody for the target ligand determines the specificity of therapeutic delivery and off-target side effects. The discovery and optimization of high-affinity antibodies to important therapeutic targets could be significantly improved by the availability of a robust, eukaryotic display technology comparable to phage display that would overcome the protein translation limitations of microorganisms. The use of eukaryotic cells would improve the diversity of the displayed antibodies that can be screened and optimized as well as more seamlessly transition into a large-scale mammalian expression system for clinical production. In this study, we demonstrate that the replication and polypeptide display characteristics of a eukaryotic retrovirus, avian leukosis virus (ALV), offers a robust, eukaryotic version of bacteriophage display. The binding affinity of a model single-chain Fv antibody was optimized by using ALV display, improving affinity >2,000-fold, from micromolar to picomolar levels. We believe ALV display provides an extension to antibody display on microorganisms and offers virus and cell display platforms in a eukaryotic expression system. ALV display should enable an improvement in the diversity of properly processed and functional antibody variants that can be screened and affinity-optimized to improve promising antibody candidates. PMID:26216971

  1. Dendritic cells loaded with apoptotic antibody-coated tumor cells provide protective immunity against B-cell lymphoma in vivo.

    Science.gov (United States)

    Franki, Suzanne N; Steward, Kristopher K; Betting, David J; Kafi, Kamran; Yamada, Reiko E; Timmerman, John M

    2008-02-01

    The in vitro priming of tumor-specific T cells by dendritic cells (DCs) phagocytosing killed tumor cells can be augmented in the presence of antitumor monoclonal antibody (mAb). We investigated whether DCs phagocytosing killed lymphoma cells coated with tumor-specific antibody could elicit antitumor immunity in vivo. Irradiated murine 38C13 lymphoma cells were cocultured with bone marrow-derived DCs in the presence or absence of tumor-specific mAb. Mice vaccinated with DCs cocultured with mAb-coated tumor cells were protected from tumor challenge (60% long-term survival), whereas DCs loaded with tumor cells alone were much less effective. The opsonized whole tumor cell-DC vaccine elicited significantly better tumor protection than a traditional lymphoma idiotype (Id) protein vaccine, and in combination with chemotherapy could eradicate preexisting tumor. Moreover, the DC vaccine protected animals from both wild-type and Id-negative variant tumor cells, indicating that Id is not a major target of the induced tumor immunity. Protection was critically dependent upon CD8(+) T cells, with lesser contribution by CD4(+) T cells. Importantly, opsonized whole tumor cell-DC vaccination did not result in tissue-specific autoimmunity. Since opsonized whole tumor cell-DC and Id vaccines appear to target distinct tumor antigens, optimal antilymphoma immunity might be achieved by combining these approaches. PMID:17993615

  2. Anti-idiotypic antibodies that protect cells against the action of diphtheria toxin

    Energy Technology Data Exchange (ETDEWEB)

    Rolf, J.M.; Gaudin, H.M.; Tirrell, S.M.; MacDonald, A.B.; Eidels, L.

    1989-03-01

    An anti-idiotypic serum prepared against the combining site (idiotype) of specific anti-diphtheria toxoid antibodies was characterized with respect to its interaction with highly diphtheria toxin-sensitive Vero cells. Although the anti-idiotypic serum protected Vero cells against the cytotoxic action of diphtheria toxin, it did not prevent the binding of /sup 125/I-labeled diphtheria toxin to the cells but did inhibit the internalization and degradation of /sup 125/I-labeled toxin. This anti-idiotypic serum immunoprecipitated a cell-surface protein from radiolabeled Vero cells with an apparent Mr of approximately 15,000. These results are consistent with the hypothesis that the anti-idiotypic serum contains antibodies that carry an internal image of an internalization site on the toxin and that a cell-surface protein involved in toxin internalization possesses a complementary site recognized by both the toxin and the anti-idiotypic antibodies.

  3. Atypical and classical memory B cells produce Plasmodium falciparum neutralizing antibodies

    DEFF Research Database (Denmark)

    Muellenbeck, Matthias F; Ueberheide, Beatrix; Amulic, Borko;

    2013-01-01

    . We show at the single cell level that natural Pf infection induces the development of classical memory B cells (CM) and atypical memory B cells (AtM) that produce broadly neutralizing antibodies against blood stage Pf parasites. CM and AtM contribute to anti-Pf serum IgG production, but only AtM show...

  4. Modeling bispecific monoclonal antibody interaction with two cell membrane targets indicates the importance of surface diffusion.

    Science.gov (United States)

    Sengers, Bram G; McGinty, Sean; Nouri, Fatma Z; Argungu, Maryam; Hawkins, Emma; Hadji, Aymen; Weber, Andrew; Taylor, Adam; Sepp, Armin

    2016-07-01

    We have developed a mathematical framework for describing a bispecific monoclonal antibody interaction with two independent membrane-bound targets that are expressed on the same cell surface. The bispecific antibody in solution binds either of the two targets first, and then cross-links with the second one while on the cell surface, subject to rate-limiting lateral diffusion step within the lifetime of the monovalently engaged antibody-antigen complex. At experimental densities, only a small fraction of the free targets is expected to lie within the reach of the antibody binding sites at any time. Using ordinary differential equation and Monte Carlo simulation-based models, we validated this approach against an independently published anti-CD4/CD70 DuetMab experimental data set. As a result of dimensional reduction, the cell surface reaction is expected to be so rapid that, in agreement with the experimental data, no monovalently bound bispecific antibody binary complexes accumulate until cross-linking is complete. The dissociation of the bispecific antibody from the ternary cross-linked complex is expected to be significantly slower than that from either of the monovalently bound variants. We estimate that the effective affinity of the bivalently bound bispecific antibody is enhanced for about 4 orders of magnitude over that of the monovalently bound species. This avidity enhancement allows for the highly specific binding of anti-CD4/CD70 DuetMab to the cells that are positive for both target antigens over those that express only one or the other We suggest that the lateral diffusion of target antigens in the cell membrane also plays a key role in the avidity effect of natural antibodies and other bivalent ligands in their interactions with their respective cell surface receptors. PMID:27097222

  5. B7h-expressing dendritic cells and plasma B cells mediate distinct outcomes of ICOS costimulation in T cell-dependent antibody responses

    Directory of Open Access Journals (Sweden)

    Larimore Kevin

    2012-06-01

    Full Text Available Abstract Background The ICOS-B7h costimulatory receptor-ligand pair is required for germinal center formation, the production of isotype-switched antibodies, and antibody affinity maturation in response to T cell-dependent antigens. However, the potentially distinct roles of regulated B7h expression on B cells and dendritic cells in T cell-dependent antibody responses have not been defined. Results We generated transgenic mice with lineage-restricted B7h expression to assess the cell-type specific roles of B7h expression on B cells and dendritic cells in regulating T cell-dependent antibody responses. Our results show that endogenous B7h expression is reduced on B cells after activation in vitro and is also reduced in vivo on antibody-secreting plasma B cells in comparison to both naïve and germinal center B cells from which they are derived. Increasing the level of B7h expression on activated and plasma B cells in B-B7hTg mice led to an increase in the number of antibody-secreting plasma cells generated after immunization and a corresponding increase in the concentration of antigen-specific high affinity serum IgG antibodies of all isotypes, without affecting the number of responding germinal center B cells. In contrast, ICOS costimulation mediated by dendritic cells in DC-B7hTg mice contributed to germinal center formation and selectively increased IgG2a production without affecting the overall magnitude of antibody responses. Conclusions Using transgenic mice with lineage-restricted B7h expression, we have revealed distinct roles of ICOS costimulation mediated by dendritic cells and B cells in the regulation of T cell-dependent antibody responses.

  6. Intratumoral delivery of CpG-conjugated anti-MUC1 antibody enhances NK cell anti-tumor activity

    OpenAIRE

    Schettini, Jorge; Kidiyoor, Amritha; Besmer, Dahlia M; Tinder, Teresa L; Roy, Lopamudra Das; Lustgarten, Joseph; Gendler, Sandra J.; Mukherjee, Pinku

    2012-01-01

    Monoclonal antibodies (mAbs) against tumor-associated antigens are useful anticancer agents. Antibody-dependent cellular cytotoxicity (ADCC) is one of the major mechanisms responsible for initiating natural killer cell (NK)-mediated killing of tumors. However, the regulation of ADCC via NK cells is poorly understood. We have investigated the cytolytic activity of NK cells against pancreatic cancer cells that were coated with an antibody directed against the human tumor antigen, Mucin-1 design...

  7. Serological survey of normal humans for natural antibody to cell surface antigens of melanoma.

    Science.gov (United States)

    Houghton, A N; Taormina, M C; Ikeda, H; Watanabe, T; Oettgen, H F; Old, L J

    1980-01-01

    Sera of 106 normal adult men were tested for antibodies reacting with cell surface antigens of three established lines of cultured malignant melanoma. Positive reactions with a protein A assay for IgG antibodies were extremely rare (1-2%). The frequency of positive reactions with assays for IgM antibodies was higher: 5-15% in immune adherence assays and 55-82% in anti-C3 mixed hemadsorption assays. After low-titered sera and sera reacting with fetal calf serum components, conventional alloantigens, and widely distributed class 3 antigens were excluded, sera from seven individuals (one with IgG antibody and six with IgM antibodies) were selected for detailed analysis. The serum containing the IgG antibody came from a healthy 65-year-old Caucasian man; titers of antibody in his serum ranged from < 1/10 to 1/40,000 in tests with different melanoma cell lines. This IgG antibody identifies a differentiation antigen of melanocytes, provisionally designated Mel 1, that distinguishes two classes of melanomas: 22 melanoma cell lines typed Mel 1+ and 17 types Mel 1-. Mel 1 is expressed by fetal fibroblasts but not adult fibroblasts and can be found on a proportion of cultured epithelial cancer cell lines (5 out of 23) but not on glioma or B-cell lines. The melanoma antigens detected by the naturally occurring IgM antibodies are serologically unrelated to Mel 1 but, like Mel 1, appear to be differentiation antigens that distinguish subsets of melanoma. These IgM antibodies detect antigens that are identical or closely related to the AH antigen, a melanoma surface antigen that was initially defined by autologous antibody in a patient with melanoma. In view of the immunogenicity of both Mel 1 and the AH antigens in humans and their occurrence on more than 50% of melanomas, it remains to be seen whether antibody to these antigens can be elicited by specific vaccination of seronegative melanoma patients and whether this will have an influence on the clinical course of the disease

  8. Red Blood Cell Antibodies in Hematology/Oncology Patients: Interpretation of Immunohematologic Tests and Clinical Significance of Detected Antibodies.

    Science.gov (United States)

    Hendrickson, Jeanne E; Tormey, Christopher A

    2016-06-01

    Red blood cell (RBC) transfusion is a cornerstone of the management of patients with hematology/oncology disorders. However, a potentially deleterious consequence of transfusion is the development of alloantibodies against blood group antigens present on RBCs. Such alloantibodies can be an obstacle in providing compatible units for transfusion. Providers in this arena must fully understand the testing performed by blood banks, as well as the consequences of detected antibodies. This article reviews immunohematologic tests, describes how autoimmune hemolytic anemia is classified by autoantibodies; outlines RBC alloimmunization rates, and presents strategies to prevent/mitigate the impact of RBC alloimmunization. PMID:27113001

  9. Development of novel monoclonal antibodies that define differentiation stages of human stromal (mesenchymal) stem cells

    DEFF Research Database (Denmark)

    Andersen, Ditte Caroline; Kortesidis, Angela; Zannettino, Andrew C W;

    2011-01-01

    Human mesenchymal stem cells (hMSC) are currently being introduced for cell therapy, yet, antibodies specific for native and differentiated MSCs are required for their identification prior to clinical use. Herein, high quality antibodies against MSC surface proteins were developed by immunizing...... differentiation. Interestingly, undifferentiated cells revealed a sole cytoplasmic distribution pattern of Collagen VI, which however changed to an extracellular matrix appearance upon osteogenic- and adipogenic differentiation. In relation to this, we found that STRO-1(+/-)/Collagen VI(-) sorted hMSC contained...... fewer differentiated alkaline phosphatase(+) cells compared to STRO-1(+/-)/Collagen VI(+) hMSC, suggesting that Collagen VI on the cell membrane exclusively defines differentiated MSCs. In conclusion, we have generated a panel of high quality antibodies to be used for characterization of MSCs, and in...

  10. Lineage tracing of human B cells reveals the in vivo landscape of human antibody class switching

    Science.gov (United States)

    Horns, Felix; Vollmers, Christopher; Croote, Derek; Mackey, Sally F; Swan, Gary E; Dekker, Cornelia L; Davis, Mark M; Quake, Stephen R

    2016-01-01

    Antibody class switching is a feature of the adaptive immune system which enables diversification of the effector properties of antibodies. Even though class switching is essential for mounting a protective response to pathogens, the in vivo patterns and lineage characteristics of antibody class switching have remained uncharacterized in living humans. Here we comprehensively measured the landscape of antibody class switching in human adult twins using antibody repertoire sequencing. The map identifies how antibodies of every class are created and delineates a two-tiered hierarchy of class switch pathways. Using somatic hypermutations as a molecular clock, we discovered that closely related B cells often switch to the same class, but lose coherence as somatic mutations accumulate. Such correlations between closely related cells exist when purified B cells class switch in vitro, suggesting that class switch recombination is directed toward specific isotypes by a cell-autonomous imprinted state. DOI: http://dx.doi.org/10.7554/eLife.16578.001 PMID:27481325

  11. A Recombinant Bispecific CD20×CD95 Antibody With Superior Activity Against Normal and Malignant B-cells.

    Science.gov (United States)

    Nalivaiko, Kristina; Hofmann, Martin; Kober, Karina; Teichweyde, Nadine; Krammer, Peter H; Rammensee, Hans-Georg; Grosse-Hovest, Ludger; Jung, Gundram

    2016-02-01

    Monoclonal antibodies directed to the B-cell-specific CD20-antigen are successfully used for the treatment of lymphomas and autoimmune diseases. Here, we compare the anti-B-cell activity of three different antibodies directed to CD20: (i) a chimeric, monospecific antibody, (ii) an Fc-optimized variant thereof, and (iii) a bispecific CD20×CD95-antibody in a newly developed recombinant format, termed Fabsc. The bispecific antibody specifically triggers the CD95 death receptor on malignant, as well as activated, normal B-cells. We found that the capability of this antibody to suppress the growth of malignant B-cells in vitro and in vivo and to specifically deplete normal, activated B-cells from peripheral blood mononuclear cell (PBMC) cultures was superior to that of the Fc-optimized monospecific antibody. This antibody in turn was more effective than its nonoptimized variant. Moreover, the bispecific antibody was the only reagent capable of significantly suppressing antibody production in vitro. Our findings imply that the bispecific CD20×CD95-antibody might become a new, prototypical reagent for the treatment of B-cell-mediated autoimmune disease. PMID:26581163

  12. Neutralizing antibodies derived from the B cells of 1918 influenza pandemic survivors.

    Science.gov (United States)

    Yu, Xiaocong; Tsibane, Tshidi; McGraw, Patricia A; House, Frances S; Keefer, Christopher J; Hicar, Mark D; Tumpey, Terrence M; Pappas, Claudia; Perrone, Lucy A; Martinez, Osvaldo; Stevens, James; Wilson, Ian A; Aguilar, Patricia V; Altschuler, Eric L; Basler, Christopher F; Crowe, James E

    2008-09-25

    Investigation of the human antibody response to influenza virus infection has been largely limited to serology, with relatively little analysis at the molecular level. The 1918 H1N1 influenza virus pandemic was the most severe of the modern era. Recent work has recovered the gene sequences of this unusual strain, so that the 1918 pandemic virus could be reconstituted to display its unique virulence phenotypes. However, little is known about adaptive immunity to this virus. We took advantage of the 1918 virus sequencing and the resultant production of recombinant 1918 haemagglutinin (HA) protein antigen to characterize at the clonal level neutralizing antibodies induced by natural exposure of survivors to the 1918 pandemic virus. Here we show that of the 32 individuals tested that were born in or before 1915, each showed seroreactivity with the 1918 virus, nearly 90 years after the pandemic. Seven of the eight donor samples tested had circulating B cells that secreted antibodies that bound the 1918 HA. We isolated B cells from subjects and generated five monoclonal antibodies that showed potent neutralizing activity against 1918 virus from three separate donors. These antibodies also cross-reacted with the genetically similar HA of a 1930 swine H1N1 influenza strain, but did not cross-react with HAs of more contemporary human influenza viruses. The antibody genes had an unusually high degree of somatic mutation. The antibodies bound to the 1918 HA protein with high affinity, had exceptional virus-neutralizing potency and protected mice from lethal infection. Isolation of viruses that escaped inhibition suggested that the antibodies recognize classical antigenic sites on the HA surface. Thus, these studies demonstrate that survivors of the 1918 influenza pandemic possess highly functional, virus-neutralizing antibodies to this uniquely virulent virus, and that humans can sustain circulating B memory cells to viruses for many decades after exposure-well into the tenth

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-01

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

  14. Synergistic cytotoxic effects of antibodies directed against different cell surface determinants

    International Nuclear Information System (INIS)

    Three antibody populations were raised in rabbits against surface antigens on guinea-pig L2C leukaemic lymphocytes: against idiotypic determinants on the lambda chain of the surface immunoglobulin, against C region determinants on the lambda chain, and against the surface antigens recognised by conventional anti-lymphocyte sera. Complement and K-cell cytotoxicities effected by the antibodies on L2C cells were studied in vitro. In both cytotoxic systems mixtures of the antibodies revealed synergy, in that the titres of the mixtures exceeded predicted additive titres of their components. The synergy was greater when the mixed antibodies were directed to determinants on the same molecule rather than to determinants on different molecules. (author)

  15. 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......The small Ca-binding protein, S100A4, has a well-established metastasis-promoting activity. Moreover, its expression is tightly correlated with poor prognosis in patients with numerous types of cancer. Mechanistically, the extracellular S100A4 drives metastasis by affecting the tumor...... 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...

  16. Indirect 125I-labeled protein A assay for monoclonal antibodies to cell surface antigens

    International Nuclear Information System (INIS)

    An assay for detection of monoclonal hybridoma antibodies against cell surface antigens is described. Samples of spent medium from the hybridoma cultures are incubated in microtest wells with cells, either as adherent monolayers or in suspension. Antibodies bound to surface antigens are detected by successive incubations with rabbit anti-immunoglobulin serum and 125I-labeled protein A from Staphylococcus aureus, followed by autoradiography of the microtest plate or scintillation counting of the individual wells. Particular advantages of this assay for screening hybridomas are: (1) commercially available reagents are used, (2) antibodies of any species and of any immunoglobulin class or subclass can be detected, and (3) large numbers of samples can be screened rapidly and inexpensively. The assay has been used to select hybridomas producing monoclonal antibodies to surface antigens of human melanomas and mouse sarcomas. (Auth.)

  17. Glycoproteins of coated pits, cell junctions, and the entire cell surface revealed by monoclonal antibodies and immunoelectron microscopy

    OpenAIRE

    1983-01-01

    Topographical descriptions of three major plasma membrane glycoproteins of murine 3T3 cells were obtained by immunoelectron microscopy with monoclonal antibodies. A glycoprotein of Mr 80,000 was distributed throughout the total cell surface. A second of Mr 90,000 was concentrated in coated pits, and a third of Mr 100,000 was localized at cell junctions.

  18. A monoclonal antibody (OPT1 to T cells which is available for paraffin-embedded materials.

    Directory of Open Access Journals (Sweden)

    Mukuzono,Hiroshi

    1991-06-01

    Full Text Available A monoclonal antibody (MAb, OPT1, reactive with T cells in formalin-fixed, paraffin-embedded tissue sections, has been identified through immunization with activated T cells from peripheral blood lymphocytes (PBL. The antibody is an IgG1 antibody as demonstrated by the Ouchterlony technique. By cytofluorometric analysis, almost all CD3+ lymphocytes and only a few CD20+ lymphocytes of peripheral blood expressed the OPT1 antigen. Nonhematolymphoid cell lines were negative for OPT1 by the immunoperoxidase staining using acetone-fixed cell lines. On the contrary, peripheral T cells, cells of two T cell lines out of four and a part of the cells of one B cell line out of two were positive for OPT1. The immunoperoxidase staining of paraffin-embedded tissue sections revealed that most of lymphocytes in T cell areas of lymph nodes expressed OPT1 antigen. Some lymphocytes in both cortex and medulla of the thymus and erythroid precursors of the bone marrow were OPT1+. In the malignant lymphoma series, approximately 90% of T cell lymphomas and 6% of B cell lymphomas reacted with OPT1. None of the Reed-Sternberg cells nor Hodgkin cells in Hodgkin's disease were positive. Consequently, OPT1 may be useful for the diagnosis and study of malignant lymphomas and other related lesions.

  19. Effective Binding of a Phosphatidylserine-Targeting Antibody to Ebola Virus Infected Cells and Purified Virions

    OpenAIRE

    Dowall, S. D.; Graham, V A; Corbin-Lickfett, K; C. Empig; Schlunegger, K.; Bruce, C B; Easterbrook, L.; Hewson, R.

    2015-01-01

    Ebola virus is responsible for causing severe hemorrhagic fevers, with case fatality rates of up to 90%. Currently, no antiviral or vaccine is licensed against Ebola virus. A phosphatidylserine-targeting antibody (PGN401, bavituximab) has previously been shown to have broad-spectrum antiviral activity. Here, we demonstrate that PGN401 specifically binds to Ebola virus and recognizes infected cells. Our study provides the first evidence of phosphatidylserine-targeting antibody reactivity again...

  20. Differences in the composition of the human antibody repertoire by B cell subsets in the blood

    OpenAIRE

    Eva Szymanska eMroczek; Ippolito, Gregory C.; Tobias eRogosch; Kam Hon eHoi; Tracy A Hwangpo; Marsha G Brand; Yingxin eZhuang; Cun Ren eLiu; Schneider, David A; Michael eZemlin; Brown, Elizabeth E.; George eGeorgiou; Schroeder, Harry W.

    2014-01-01

    The vast initial diversity of the antibody repertoire is generated centrally by means of a complex series of V (D) J gene rearrangement events, variation in the site of gene segment joining, and TdT catalyzed N- region addition. Although the diversity is great, close inspection has revealed distinct and unique characteristics in the antibody repertoires expressed by different B cell developmental subsets. In order to illustrate our approach to repertoire analysis, we present an in-depth com...

  1. Differences in the Composition of the Human Antibody Repertoire by B Cell Subsets in the Blood

    OpenAIRE

    Mroczek, Eva Szymanska; Ippolito, Gregory C.; Rogosch, Tobias; Hoi, Kam Hon; Tracy A Hwangpo; Marsha G Brand; Zhuang, Yingxin; Liu, Cun Ren; Schneider, David A; Zemlin, Michael; Brown, Elizabeth E.; Georgiou, George; Schroeder, Harry W.

    2014-01-01

    The vast initial diversity of the antibody repertoire is generated centrally by means of a complex series of V(D)J gene rearrangement events, variation in the site of gene segment joining, and TdT catalyzed N-region addition. Although the diversity is great, close inspection has revealed distinct and unique characteristics in the antibody repertoires expressed by different B cell developmental subsets. In order to illustrate our approach to repertoire analysis, we present an in-depth comparis...

  2. Guidelines to cell engineering for monoclonal antibody production

    OpenAIRE

    Costa, A.; Rodrigues, E; Henriques, Mariana; Azeredo, Joana; Oliveira, Rosário

    2010-01-01

    Monoclonal antibodies (mAbs) are currently used for many diagnostic and therapeutic applications. The high demand for these biopharmaceuticals has led to the development of large-scale manufacturing processes, with productivity improvements being mainly achieved by optimization of bioreactor systems. However, more recently, the early steps of production, previous to bioreactor culture, have been presented as alternative areas where productivity enhancements can be achieved. Thus, ...

  3. Xenohybridization of Epstein-Barr virus-transformed cells for the production of human monoclonal antibodies.

    Science.gov (United States)

    Tiebout, R F; Stricker, E A; Oosterhof, F; van Heemstra, D J; Zeijlemaker, W P

    1985-12-01

    Transformation of human B lymphocytes, obtained from hyperimmune donors with Epstein-Barr virus, yields polyclonal cell populations in which a minority of cells produce IgG antibodies of predetermined specificity, whereas the majority of cells produce 'non-specific' immunoglobulin (mainly of the IgM class). Such lymphoblastoid cell lines can be easily propagated in high-density cultures. Because cloning at 1 cell per well is not possible, stabilization of lymphoblastoid cell lines by limiting dilution is not feasible and most newly established lines cease to produce specific antibody within a few weeks. Xenohybrids, resulting from fusion of Epstein-Barr virus-transformed cells with NS1 mouse plasmacytoma cells, can be cloned at 1 cell per well. Stable xenohybridoma subclones, producing antibody of the desired specificity, can be isolated after a series of limiting dilutions. In a model system, we have studied the efficiency of xenohybridization of human lymphoblastoid cells. Using this system, we have constructed IgG anti-tetanus-toxoid- and IgG anti-HBsAg-producing cell lines. Next, we investigated whether transformation with Epstein-Barr virus is essential in such a two-step procedure or whether a polyclonal stimulator, such as pokeweed mitogen, could also be used. It was found that antibody-producing xenohybrids can be obtained after stimulation with pokeweed mitogen. However, this latter system is subject to more variations and lacks the advantage of pre-selection of antibody-producing cells as compared to xenohybridization after transformation. PMID:3003887

  4. Antibody-Free Magnetic Cell Sorting of Genetically Modified Primary Human CD4+ T Cells by One-Step Streptavidin Affinity Purification

    OpenAIRE

    Matheson, Nicholas J.; Peden, Andrew A.; Lehner, Paul J.

    2014-01-01

    Existing methods for phenotypic selection of genetically modified mammalian cells suffer disadvantages of time, cost and scalability and, where antibodies are used to bind exogenous cell surface markers for magnetic selection, typically yield cells coated with antibody-antigen complexes and beads. To overcome these limitations we have developed a method termed Antibody-Free Magnetic Cell Sorting in which the 38 amino acid Streptavidin Binding Peptide (SBP) is displayed at the cell surface by ...

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

    Directory of Open Access Journals (Sweden)

    Fan Jie

    2012-12-01

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

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

    Science.gov (United States)

    Lu, Chia-Yen; Chen, Gregory J; Tai, Pei-Han; Yang, Yu-Chen; Hsu, Yu-Shen; Chang, Mingi; Hsu, Chuan-Lung

    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. PMID:27040766

  7. Affinity isolation of antigen-specific circulating B cells for generation of phage display-derived human monoclonal antibodies

    DEFF Research Database (Denmark)

    Ditzel, Henrik

    2009-01-01

    A method is described for affinity isolation of antigen-specific circulating B cells of interest for subsequent generation of immune antibody phage display libraries. This approach should overcome the problem of low yields of monoclonal antibodies of interest in the libraries generated from...... the frequency of antibody phage particles of interest in the library and allow for efficient isolation monoclonal antibodies with the predefined specificity....

  8. Complement-dependent cytotoxicity of antibodies reactive with HIV-induced cell surface antigens in HIV-carrying haemophiliacs

    International Nuclear Information System (INIS)

    Sera obtained from HIV positive and from uninfected hemophiliacs and from healthy subjects were investigated for the presence of lymphocytotoxic antibodies. Using the 51Cr-release test, HIV-positive hemophiliacs were found to produce serum antibodies exerting a complement-dependent cytotoxic effect on HIV-infected T4 cells. The antibodies were reactive mainly when HIV-infected target cells were stimulated with concanavalin A. The results of complement-dependent antibody cytotoxicity and indirect membrane immunofluorescence tests suggest that envelope antigen(s) of HIV may be the target(s) for cytotoxic antibodies. (author)

  9. Application of a human osteogenic sarcoma cell culture for detection of human cytomegalovirus antibody by immunofluorescence tests.

    OpenAIRE

    Furukawa, T; Herold, R; Zolnick, P; Plotkin, S A

    1981-01-01

    A human osteogenic sarcoma cell culture is useful in the immunofluorescence serological test for detecting human cytomegalovirus antibody. These sarcoma cells are chronically infected with human cytomegalovirus and provide a constant number of immunofluorescence-positive cells.

  10. Metabolic requirements for hormone-induced resistance to antibody-complement mediated killing of tumor cells

    International Nuclear Information System (INIS)

    Line-1 guinea pig hepatoma cells are susceptible to killing by anti-Forssman IgM antibody plus guinea pig complement (GPC). When these tumor cells are incubated with insulin, epinephrine, hydrocortisone, or prednisolone, the cells show a marked reduction in their susceptibility to antibody-C-mediated killing. If the ability of the cells to synthesize DNA, RNA, and protein is impaired by pretreatment with metabolic inhibitors, x-irradiation, or culture in nutrient-deficient media, the hormones are no longer effective in rendering the cells resistant to killing. If only DNA synthesis is impaired, but not RNA and protein synthesis, the hormones are effective. The inability of cells inhibited in their macromolecular synthesis to be rendered resistant to killing after hormone treatment is not due to an inability of the cells to bind hormone

  11. Quantitative determination of islet cell surface antibodies using 125I-protein A

    International Nuclear Information System (INIS)

    A quantitative method to measure islet cell surface antibodies in human patients has been developed using 125I-protein A. Isolated, dispersed, viable rat islet cells prepared by collagenase digestion were fixed in 4% paraformaldehyde to allow storage for up to 7 wk at 4 degrees C. Human sera, heat inactivated and adsorbed with rat liver and kidney powder (100 mg/ml), were incubated with the fixed cells (50 x 10(3)) for 60 min at 37 degrees C. Thereafter the cells were washed and exposed to 5 x 10(5) cpm 125I-protein A, which binds to IgG attached to the cell surface. Assay precision (14%) and reproducibility (16%) were established by repeated analysis of pooled sera from healthy individuals and IDDM patients using pooled batches of islet cells. Using this method, islet cell surface antibodies were detected in 35% of insulin-dependent diabetic patients

  12. Effects of Monoclonal Antibody Cetuximab on Proliferation of Non-small Cell Lung Cancer Cell lines

    Directory of Open Access Journals (Sweden)

    Zhen CHEN

    2010-08-01

    Full Text Available Background and objective The epidermal growth factor receptor (EGFR monoclonal antibody cetuximab has been used widely in non-small cell lung cancer patients. The aim of this study is to explore the effect of lung cancer cells (A549, H460, H1299, SPC-A-1 which were treated by cetuximab in vitro. Methods We studied the effects of increasing concentrations of cetuximab (1 nmol/L-625 nmol/L in four human lung cancer cell lines (A549, SPC-A-1, H460, H1229. CCK8 measured the inhibition of cell proliferation in each group. A549, SPC-A-1 were marked by PI and the statuses of apoptosis were observed. Western blot were used to detect the proliferation-related signaling protein and apoptosis-related protein in A549. Results The treatment with cetuximab resulted in the effect on cell proliferation and apoptosis in a time- and dosedependent manner. The expression of activated key enzymes (p-AKT, p-EGFR, p-MAPK in EGFR signaling transduction pathway were down-regulated more obviously. Conclusion Cetuximab is an effective targeted drug in the treatment of lung cancer cell lines, tissues, most likely to contribute to the inhibition of key enzymes in EGFR signaling transduction pathway.

  13. The use of radiolabeled monoclonal antibodies for cell labeling in vivo

    International Nuclear Information System (INIS)

    The authors have evaluated the potential of in vivo cell surface labeling using radiolabeled monoclonal antibodies (MoAbs) directed against their surface antigens. Two MoAbs, a specific antibody (anti-Thy-1 OX7) and a nonspecific control antibody (anti-CEA) were coupled with DTPA, labeled with /sup 111/In and evaluated against rat thymocytes, marrow cells, and lymphoma cells (all known to be Thy-1 positive) both in vitro and in vivo. Enumeration of the cells which bound the radiolabeled MoAb was done by detecting the antibody on the cell surface with a Fl-F(ab')/sub 2/ goat anti-mouse IgG and analyzing fluorescence (F1) in a flow cytometer (FACS). The thymocytes, which could be labeled in whole blood, showed a labeling efficiency of 80-100%. The labeling, which could be inhibited by cold antibody, was stable up to 72 hours and did not interfere with either cell viability or functional integrity. Following IV injection of the MoAbs in normal rats, there was very good visualization of the bone marrow not seen with the control. Analysis of the marrow cells on the FACS showed that at two hours over 60% of the marrow cells were specifically labeled as against 2% for the control. Within 15 minutes of injecting /sup 111/In-OX7 into rats with lymphoma, 70% of the activity in blood was bound to circulating lymphoma cells. The ability to stably label, rapidly target, and image specific cell populations in vivo has wide ranging diagnostic and therapeutic implications

  14. Specific antibodies modulate the interactions of adenovirus type 5 with dendritic cells

    International Nuclear Information System (INIS)

    Adenovirus type 5 (Ad5) is able to induce an efficient CD8+ T lymphocyte (CTL) response against a transgene product, a property thought to be linked to its ability to transduce dendritic cells (DCs). Little, however, is known about the capacity of Ad5 to interact with DCs in the presence of specific antibodies, although most people test positive for antibodies directed against Ad5. In the present study, we found that in the presence of Ad5 antibodies, a large fraction of Ad5 binds very efficiently to DCs, and that this binding is FcγRII/FcγRIII dependent. Nevertheless, in the presence of high levels of antibodies against the whole virion, Ad5 entry was inhibited. Increased binding led to increased entry in DCs in the presence of fiber-specific antibodies or in the presence of low amounts of a whole antiserum raised against whole virions, showing that the relative concentration of antibodies directed against fiber and penton base plays a major role in entry efficacy. Nevertheless, mice previously immunized with virions or purified fiber developed a lower transgene-specific CD8+ T cell response than naive mice, although their serum appeared to increase virus entry into DCs in vitro

  15. Structural analysis of B-cell epitopes in antibody:protein complexes

    DEFF Research Database (Denmark)

    Kringelum, Jens Vindahl; Nielsen, Morten; Padkjær, Søren Berg; Lund, Ole

    developed a novel framework for comparing and superimposing B-cell epitopes and applied it on a dataset of 107 non-similar antigen:antibody structures extracted from the PDB database. With the presented framework, we were able to describe the general B-cell epitope as a flat, oblong, oval shaped volume......The binding of antigens to antibodies is one of the key events in an immune response against foreign molecules and is a critical element of several biomedical applications including vaccines and immunotherapeutics. For development of such applications, the identification of antibody binding sites...... (B-cell epitopes) is essential. However experimental epitope mapping is highly cost-intensive and computer-aided methods do in general have moderate performance. One major reason for this moderate performance is an incomplete understanding of what characterizes an epitope. To fill this gap, we here...

  16. Radioimmunotherapy of Non-Hodgkin's Lymphoma. The interaction of radiation and antibody with lymphoma cells

    International Nuclear Information System (INIS)

    Whilst many patients with indolent Non-Hodgkin's Lymphoma (NHL) can achieve clinical remissions to first-line chemotherapy and/or radiotherapy, most will relapse. Current treatment options for relapsing patients are limited since most patients become resistant to repeated chemotherapy. Death usually occurs within 10 years of diagnosis. Overall, these disappointing results have not changed significantly in a quarter of a century and clearly advocate the urgent priority to research into potential new therapeutic approaches into this diverse and increasingly prevalent group of human tumours. Radioimmunotherapy (RIT) is currently under investigation as a new approach for the treatment of this disease. In this form of treatment, radionuclide-labeled monoclonal antibodies are able to deliver selective systemic irradiation by recognising tumour-associated antigens. The use of RIT with radiolabeled anti-CD20 antibodies in patients with recurrent B-cell lymphoma has resulted in extremely high rates of durable complete remissions. The optimal approach and mechanisms of action of successful RIT remain however largely unknown. The work described in this thesis has focused on clarifying some of the important determinants and mechanisms of effective RIT of syngeneic B-cell lymphoma, both in vivo and in vitro. A successful animal model of RIT in B cell lymphomas was established by initially generating a panel of antibodies against mouse B cell antigens. The in vitro characteristics of these antibodies have been compared with their subsequent performance, in biodistribution studies and RIT in vivo. For the first time in an in vivo model the relative contributions of antibody and irradiation are described. Some antibodies including anti-MHC Class II were shown to be effective delivery vehicles of low doses of Iodine-131. These antibodies, which appear to be inactive delivery vehicles can cure animals with low burdens of tumour. However antibodies such as anti-idiotype and anti-CD40

  17. Antibody-independent control of gamma-herpesvirus latency via B cell induction of anti-viral T cell responses.

    Directory of Open Access Journals (Sweden)

    Kelly B McClellan

    2006-06-01

    Full Text Available B cells can use antibody-dependent mechanisms to control latent viral infections. It is unknown whether this represents the sole function of B cells during chronic viral infection. We report here that hen egg lysozyme (HEL-specific B cells can contribute to the control of murine gamma-herpesvirus 68 (gammaHV68 latency without producing anti-viral antibody. HEL-specific B cells normalized defects in T cell numbers and proliferation observed in B cell-/- mice during the early phase of gammaHV68 latency. HEL-specific B cells also reversed defects in CD8 and CD4 T cell cytokine production observed in B cell-/- mice, generating CD8 and CD4 T cells necessary for control of latency. Furthermore, HEL-specific B cells were able to present virally encoded antigen to CD8 T cells. Therefore, B cells have antibody independent functions, including antigen presentation, that are important for control of gamma-herpesvirus latency. Exploitation of this property of B cells may allow enhanced vaccine responses to chronic virus infection.

  18. Memory B cell antibodies to HIV-1 gp140 cloned from individuals infected with clade A and B viruses.

    Directory of Open Access Journals (Sweden)

    Hugo Mouquet

    Full Text Available Understanding the antibody response to HIV-1 in humans that show broad neutralizing serologic activity is a crucial step in trying to reproduce such responses by vaccination. Investigating antibodies with cross clade reactivity is particularly important as these antibodies may target conserved epitopes on the HIV envelope gp160 protein. To this end we have used a clade B YU-2 gp140 trimeric antigen and single-cell antibody cloning methods to obtain 189 new anti-gp140 antibodies representing 51 independent B cell clones from the IgG memory B cells of 3 patients infected with HIV-1 clade A or B viruses and exhibiting broad neutralizing serologic activity. Our results support previous findings showing a diverse antibody response to HIV gp140 envelope protein, characterized by differentially expanded B-cell clones producing highly hypermutated antibodies with heterogenous gp140-specificity and neutralizing activity. In addition to their high-affinity binding to the HIV spike, the vast majority of the new anti-gp140 antibodies are also polyreactive. Although none of the new antibodies are as broad or potent as VRC01 or PG9, two clonally-related antibodies isolated from a clade A HIV-1 infected donor, directed against the gp120 variable loop 3, rank in the top 5% of the neutralizers identified in our large collection of 185 unique gp140-specific antibodies in terms of breadth and potency.

  19. Celiac anti-type 2 transglutaminase antibodies induce phosphoproteome modification in intestinal epithelial Caco-2 cells.

    Directory of Open Access Journals (Sweden)

    Gaetana Paolella

    Full Text Available BACKGROUND: Celiac disease is an inflammatory condition of the small intestine that affects genetically predisposed individuals after dietary wheat gliadin ingestion. Type 2-transglutaminase (TG2 activity seems to be responsible for a strong autoimmune response in celiac disease, TG2 being the main autoantigen. Several studies support the concept that celiac anti-TG2 antibodies may contribute to disease pathogenesis. Our recent findings on the ability of anti-TG2 antibodies to induce a rapid intracellular mobilization of calcium ions, as well as extracellular signal-regulated kinase phosphorylation, suggest that they potentially act as signaling molecules. In line with this concept, we have investigated whether anti-TG2 antibodies can induce phosphoproteome modification in an intestinal epithelial cell line. METHODS AND PRINCIPAL FINDINGS: We studied phosphoproteome modification in Caco-2 cells treated with recombinant celiac anti-TG2 antibodies. We performed a two-dimensional electrophoresis followed by specific staining of phosphoproteins and mass spectrometry analysis of differentially phosphorylated proteins. Of 14 identified proteins (excluding two uncharacterized proteins, three were hypophosphorylated and nine were hyperphosphorylated. Bioinformatics analyses confirmed the presence of phosphorylation sites in all the identified proteins and highlighted their involvement in several fundamental biological processes, such as cell cycle progression, cell stress response, cytoskeletal organization and apoptosis. CONCLUSIONS: Identification of differentially phosphorylated proteins downstream of TG2-antibody stimulation suggests that in Caco-2 cells these antibodies perturb cell homeostasis by behaving as signaling molecules. We hypothesize that anti-TG2 autoantibodies may destabilize the integrity of the intestinal mucosa in celiac individuals, thus contributing to celiac disease establishment and progression. Since several proteins here

  20. HIV-Specific Antibody-Dependent Cellular Cytotoxicity (ADCC) -Mediating Antibodies Decline while NK Cell Function Increases during Antiretroviral Therapy (ART)

    DEFF Research Database (Denmark)

    Skov Jensen, Sanne; Fomsgaard, Anders; Borggren, Marie; Tingstedt, Jeanette Linnea; Gerstoft, Jan; Kronborg, Gitte; Rasmussen, Line Dahlerup; Pedersen, Court; Karlsson, Ingrid

    2015-01-01

    Understanding alterations in HIV-specific immune responses during antiretroviral therapy (ART), such as antibody-dependent cellular cytotoxicity (ADCC), is important in the development of novel strategies to control HIV-1 infection. This study included 53 HIV-1 positive individuals. We evaluated...... the ability of effector cells and antibodies to mediate ADCC separately and in combination using the ADCC-PanToxiLux assay. The ability of the peripheral blood mononuclear cells (PBMCs) to mediate ADCC was significantly higher in individuals who had been treated with ART before seroconversion......, compared to the individuals initiating ART at a low CD4+ T cell count (<350 cells/μl blood) and the ART-naïve individuals. The frequency of CD16 expressing natural killer (NK) cells correlated with both the duration of ART and Granzyme B (GzB) activity. In contrast, the plasma titer of antibodies mediating...

  1. Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies

    International Nuclear Information System (INIS)

    Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs was demonstrated by SDS-PAGE and Western blot analysis. Recombinant baculovirus infection of insect cells yielded high levels of VLPs, which were shown to stimulate cytokine secretion from human dendritic cells similar to VLPs produced in mammalian cells. The immunogenicity of Ebola VLPs produced in insect cells was evaluated by immunization of mice. Analysis of antibody responses showed that most of the GP-specific antibodies were of the IgG2a subtype, while no significant level of IgG1 subtype antibodies specific for GP was induced, indicating the induction of a Th1-biased immune response. Furthermore, sera from Ebola VLP immunized mice were able to block infection by Ebola GP pseudotyped HIV virus in a single round infection assay, indicating that a neutralizing antibody against the Ebola GP protein was induced. These results show that production of Ebola VLPs in insect cells using recombinant baculoviruses represents a promising approach for vaccine development against Ebola virus infection

  2. Preparation of monoclonal antibody against apoptosis-associated antigens of hepatoma cells by subtractive immunization

    Institute of Scientific and Technical Information of China (English)

    Lian-Jun Yang; Wen-Liang Wang

    2002-01-01

    AIM: To elucidate the expression of the apoptosis-associatedmolecules in human primary hepatocellular carcinoma (HCC)cells, and prepare the monoclonal antibodies (mAb) againstthe apoptosis-associated antigens of HCC cells.METHODS: Human HCC cell line HCC-9204 cells wereinduced apoptosis with 60 mL.L-1 ethanol for 6 h and theirmorphological changes were observed by transmissionelectron microscope. The cell DNA fragmentations weredetected by Terminal Deoxynucleotidyl transferase-mediateddUTP nick end labeling (TUNEL) assay, and the cell DNAcontents by flow cytometry. Ten mice were immunized withethanol-induced apoptotic HCC-9204 cells with the methodof subtractive immunization, while the other 10 mice usedas the control were immunized by the routine procedures.The tail blood of all the mice were prepared after the lastimmunization, and the produced antibodies were determinedby the immunocytochemical ABC staining. The splenic cellsof the mice whose tail blood sera-HCC-9204 cells serumreactions were most different between the apoptotic andthe non-apoptotic were prepared and fused with the mousemyeloma cell line SP2/0 cells. The positive antibodies wereselected by ELISA assay. The fusion rates of hybridoma cellsand the producing rates of antibodies were calculated. Thefused cells that secreted candidate objective antibody werecloned continually with the of limited dilution method, andthen selected and analyzed further by theimmunocytochemical ABC staining. The chromosomes of thecloned hybridoma cells that secreted objective mAb and themAb immunoglobulin (Ig) subtype of the prepared mAb werealso determined. The molecular mass of the mAb associatedantigen was analyzed by Western blot assay.RESULTS: HCC-9204 cells treated with 60 mL.L-1 ethanolfor 6 h, manifested obvious apoptotic morphological changes,the majority of the cells were TUNEL-positive, and the sub-G1 apoptotic peak was evident. There were 2 mice in theexperimental group whose tail blood serum reacted

  3. Immunological characterization of proteins detected by phosphotyrosine antibodies in cells transformed by Rous sarcoma virus.

    OpenAIRE

    Linder, M E; Burr, J G

    1988-01-01

    Phosphotyrosine antibodies were used to identify tyrosine-phosphorylated proteins in Rous sarcoma virus (RSV)-transformed chicken embryo fibroblasts. A large number of tyrosine phosphoproteins were detected. A similar set of proteins was observed in RSV-transformed murine cells. An 85,000-dalton protein, however, was present in transformed avian cells but missing in transformed murine cells. Neither the 85,000-dalton protein nor any of the other tyrosine phosphoproteins appeared to be viral s...

  4. Serum antibodies to whole-cell and recombinant antigens of Borrelia burgdorferi in cottontail rabbits.

    Science.gov (United States)

    Magnarelli, Louis A; Norris, Steven J; Fikrig, Erol

    2012-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985-86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, or VlsE) during different seasons, but there was no reactivity to outer surface protein (Osp)A or OspB. Seventy-six of the 102 sera (75%) analyzed were reactive with one or more of the antigens; 61 of the positive samples (80%) reacted to whole-cell antigens, followed by results for the p35 (58%, 44/76), VlsE (43%, 33/76), and p37 (29%, 22/ 76) antigens. Fifty-eight sera (76%) contained antibodies to the VlsE or p35 antigens with or without reactivity to whole-cell antigens. High antibody titers (≥1:2,560) recorded for 52 sera indicate robust antibody production. In analyses for IgM antibodies in an ELISA containing whole-cell antigens, there were 30 positive sera; titers ranged from 1:160 to 1:640. There was minimal cross-reactivity when rabbit antisera to Treponema pallidum or four serovars of Leptospira interrogans were screened against B. burgdorferi antigens. Based on more-specific results, VlsE and p35 antigens appear to be useful markers for detecting possible B. burgdorferi infections. PMID:22247369

  5. Dendritic cell and macrophage staining by monoclonal antibodies in tissue sections and epidermal sheets.

    OpenAIRE

    Flotte, T. J.; Springer, T A; Thorbecke, G. J.

    1983-01-01

    Mouse tissue sections were stained by monoclonal antibodies to macrophage antigens (Mac-1 (M1/70), Mac-2 (M3/38), Mac-3 (M3/84) with the use of immunoperoxidase. Mac-1 was located diffusely in the cytoplasm of round cells in a high percentage of alveolar macrophages, resident peritoneal and bone marrow cells, in splenic red pulp, and in rare perivascular cells in the thymus. Mac-1 was absent in epithelial cells and Langerhans cells. Mac-2 was strongly positive in many dendritic cells in the t...

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

    OpenAIRE

    1990-01-01

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

  7. Polyanhydride Nanovaccines Induce Germinal Center B Cell Formation and Sustained Serum Antibody Responses.

    Science.gov (United States)

    Vela Ramirez, Julia E; Tygrett, Lorraine T; Hao, Jihua; Habte, Habtom H; Cho, Michael W; Greenspan, Neil S; Waldschmidt, Thomas J; Narasimhan, Balaji

    2016-06-01

    Biodegradable polymeric nanoparticle-based subunit vaccines have shown promising characteristics by enhancing antigen presentation and inducing protective immune responses when compared with soluble protein. Specifically, polyanhydride nanoparticle-based vaccines (i.e., nanovaccines) have been shown to successfully encapsulate and release antigens, activate B and T cells, and induce both antibody- and cell-mediated immunity towards a variety of immunogens. One of the characteristics of strong thymus-dependent antibody responses is the formation of germinal centers (GC) and the generation of GC B cells, which is part of the T helper cell driven cellular response. In order to further understand the role of nanovaccines in the induction of antigen-specific immune responses, their ability to induce germinal center B cell formation and isotype switching and the effects thereof on serum antibody responses were investigated in these studies. Polyanhydride nanovaccines based on 1,6-bis(p-carboxyphenoxy)hexane and 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane were used to subcutaneously administer a viral antigen. GC B cell formation and serum antibody responses induced by the nanovaccines were compared to that induced by alum-based vaccine formulations. It was demonstrated that a single dose of polyanhydride nanovaccines resulted in the formation of robust GCs and serum antibody in comparison to that induced by the alum-based formulation. This was attributed to the sustained release of antigen provided by the nanovaccines. When administered in a multiple dose regimen, the highest post-immunization titer and GC B cell number was enhanced, and the immune response induced by the nanovaccines was further sustained. These studies provide foundational information on the mechanism of action of polyanhydride nanovaccines. PMID:27319223

  8. Antibody against the insulin receptor causes disappearance of insulin receptors in 3T3-L1 cells: a possible explanation of antibody-induced insulin resistance.

    OpenAIRE

    Grunfeld, C.

    1984-01-01

    The effect of a rabbit antibody induced against the rat insulin receptor (RAR) was tested using cultured 3T3-L1 fat cells. As previously seen with antibodies against the insulin receptor from patients with the type B syndrome of insulin resistance and acanthosis nigricans, RAR acutely mimicked the action of insulin by stimulating deoxyglucose uptake. After prolonged exposure of 3T3-L1 cells to RAR, insulinomimetic activity was lost and the cells became resistant to the action of insulin. This...

  9. Characterization of host lymphoid cells in antibody-facilitated bone marrow chimeras

    International Nuclear Information System (INIS)

    The authors have produced stable murine antibody-facilitated (AF) chimeras by the simultaneous injection of P1 bone marrow cells and anti-P2 monoclonal antibody into normal (unirradiated) adult (P1 X P2)F1 recipients. These AF chimeras are healthy, long-lived, and exhibit no overt signs of graft-versus-host disease. They are immunocompetent and tolerant of host, P2-encoded alloantigens. Donor cell engraftment and takeover, monitored by glucosephosphate isomerase isozyme patterns, is usually complete (greater than 95%) in the peripheral blood, bone marrow, and hemopoietic stem cell compartments of long-term (greater than 3 months posttransplantation) AF chimeras. The authors report here, however, that splenic, lymph node, and thymic leukocytes of AF chimeras represent donor/host chimeric populations. Spleen cell populations of AF chimeras exhibit substantial chimera-to-chimera variation in the preponderant residual host cell type(s) present. Interpretations of the implications of these findings are discussed

  10. Seroprevalence of unexpected red blood cell antibodies among pregnant women in Uganda.

    Science.gov (United States)

    Eipl, K; Nakabiito, C; Bwogi, K; Motevalli, M; Roots, A; Blagg, L; Jackson, J B

    2012-01-01

    We conducted a population-based, cross-sectional study among pregnant women in Kampala, Uganda, to determine ABO and D blood types and to determine the percentage who have unexpected red blood cell (RBC) antibodies and their specificities. De-identified blood samples from routine testing of 1001 pregnant women at the Mulago Hospital antenatal clinics in Kampala were typed for ABO and D and screened for the presence of unexpected RBC antibodies with confirmation and subsequent antibody identification. Of the 1001 blood samples tested, 48.9 percent, 26.4 percent, 21.0 percent, and 3.8 percent tested positive for blood groups 0, A, B, and AB, respectively. Of these samples, 23 (2.3%)were negative forD, and 55 (5.5%) showed initial reactivity with at least one screening RBC. The RBC antibody screen was repeated on these 55 samples, and antibody identification was performed at the Johns Hopkins Hospital Blood Bank in Baltimore, Maryland. Twenty-one of the 55 samples were confirmed to have evidence of agglutination. Nine of the 21 samples demonstrated the presence of clinically significant RBC antibodies with anti-S being the most common, 8 samples demonstrated the presence of benign or naturally occurring antibodies, and 4 had only inconclusive reactivity. This study revealed a relatively high frequency of D and a low frequency of demonstrable clinically significant alloantibodies that may cause hemolytic disease of the newborn or hemolytic transfusion reactions among pregnant women in Kampala, with anti-S being the most frequent antibody specificity. PMID:23421539

  11. Automated harvesting and 2-step purification of unclarified mammalian cell-culture broths containing antibodies.

    Science.gov (United States)

    Holenstein, Fabian; Eriksson, Christer; Erlandsson, Ioana; Norrman, Nils; Simon, Jill; Danielsson, Åke; Milicov, Adriana; Schindler, Patrick; Schlaeppi, Jean-Marc

    2015-10-30

    Therapeutic monoclonal antibodies represent one of the fastest growing segments in the pharmaceutical market. The growth of the segment has necessitated development of new efficient and cost saving platforms for the preparation and analysis of early candidates for faster and better antibody selection and characterization. We report on a new integrated platform for automated harvesting of whole unclarified cell-culture broths, followed by in-line tandem affinity-capture, pH neutralization and size-exclusion chromatography of recombinant antibodies expressed transiently in mammalian human embryonic kidney 293T-cells at the 1-L scale. The system consists of two bench-top chromatography instruments connected to a central unit with eight disposable filtration devices used for loading and filtering the cell cultures. The staggered parallel multi-step configuration of the system allows unattended processing of eight samples in less than 24h. The system was validated with a random panel of 45 whole-cell culture broths containing recombinant antibodies in the early profiling phase. The results showed that the overall performances of the preparative automated system were higher compared to the conventional downstream process including manual harvesting and purification. The mean recovery of purified material from the culture-broth was 66.7%, representing a 20% increase compared to that of the manual process. Moreover, the automated process reduced by 3-fold the amount of residual aggregates in the purified antibody fractions, indicating that the automated system allows the cost-efficient and timely preparation of antibodies in the 20-200mg range, and covers the requirements for early in vitro and in vivo profiling and formulation of these drug candidates. PMID:26431859

  12. Proteomic differences in recombinant CHO cells producing two similar antibody fragments.

    Science.gov (United States)

    Sommeregger, Wolfgang; Mayrhofer, Patrick; Steinfellner, Willibald; Reinhart, David; Henry, Michael; Clynes, Martin; Meleady, Paula; Kunert, Renate

    2016-09-01

    Chinese hamster ovary (CHO) cells are the most commonly used mammalian hosts for the production of biopharmaceuticals. To overcome unfavorable features of CHO cells, a lot of effort is put into cell engineering to improve phenotype. "Omics" studies investigating elevated growth rate and specific productivities as well as extracellular stimulus have already revealed many interesting engineering targets. However, it remains largely unknown how physicochemical properties of the recombinant product itself influence the host cell. In this study, we used quantitative label-free LC-MS proteomic analyses to investigate product-specific proteome differences in CHO cells producing two similar antibody fragments. We established recombinant CHO cells producing the two antibodies, 3D6 and 2F5, both as single-chain Fv-Fc homodimeric antibody fragments (scFv-Fc). We applied three different vector strategies for transgene delivery (i.e., plasmid, bacterial artificial chromosome, recombinase-mediated cassette exchange), selected two best performing clones from transgene variants and transgene delivery methods and investigated three consecutively passaged cell samples by label-free proteomic analysis. LC-MS-MS profiles were compared in several sample combinations to gain insights into different aspects of proteomic changes caused by overexpression of two different heterologous proteins. This study suggests that not only the levels of specific product secretion but the product itself has a large impact on the proteome of the cell. Biotechnol. Bioeng. 2016;113: 1902-1912. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. PMID:26913574

  13. Mechanisms of antibody-dependent cellular cytotoxicity: the use of effector cells from chronic granulomatous disease patients as investigative probes.

    OpenAIRE

    Katz, P.; Simone, C B; Henkart, P A; Fauci, A S

    1980-01-01

    The present study characterized the antibody-dependent cellular cytoxicity (ADCC) of leukocyte effector cells (neutrophils, lymphocytes, and monocytes) from normal subjects and from chronic granulomatous disease (CGD) patients. CGD phagocytic cells (neutrophils and monocytes) had depressed ADCC activity against antibody-coated human erythrocyte (HRBC) targets in suspension cultures indicative of abnormal intracellular postphagocytic killing. However, when phagocytosis was prevented by using a...

  14. NK cell depletion and recovery in SCID mice treated with anti-NK1.1 antibody.

    OpenAIRE

    Jerzy Kawiak; Danuta Wasilewska; Grazyna Hoser; Joanna Kulesza

    2006-01-01

    The anti-NK1.1 antibody produced by PK136 hybridoma cell line administered subcutaneously to SCID mice effectively decreased the level of peripheral blood NK cells and weight of the spleen for 3-4 days. The antibody treatment did not harm the general state of the animal, and may be practically applied in xenograft experiments.

  15. NK cell depletion and recovery in SCID mice treated with anti-NK1.1 antibody.

    Directory of Open Access Journals (Sweden)

    Jerzy Kawiak

    2006-06-01

    Full Text Available The anti-NK1.1 antibody produced by PK136 hybridoma cell line administered subcutaneously to SCID mice effectively decreased the level of peripheral blood NK cells and weight of the spleen for 3-4 days. The antibody treatment did not harm the general state of the animal, and may be practically applied in xenograft experiments.

  16. Rare Association of Anti-Hu Antibody Positive Paraneoplastic Neurological Syndrome and Transitional Cell Bladder Carcinoma

    Directory of Open Access Journals (Sweden)

    S. Lukacs

    2012-01-01

    Full Text Available Introduction. Paraneoplastic encephalomyelitis (PEM and subacute sensory neuronopathy (SSN are remote effects of cancer, usually associated with small-cell lung carcinoma and positive anti-Hu antibody. We describe the rare association of bladder transitional cell carcinoma (TCC with anti-Hu antibody positivity resulting in this paraneoplastic neurological syndrome. Patient. A 76-year-old female presented with bilateral muscle weakness and paraesthesia of the upper and lower limbs in a length-dependent “glove and stocking” distribution. Central nervous system symptoms included cognitive problems, personality change, and truncal ataxia. Case notes and the literature were reviewed. Result. Autoantibody screening was positive for anti-Hu antibody (recently renamed antineuronal nuclear antibody 1, ANNA-1. The diagnosis of PEM and SSN was supported by MRI and lumbar puncture results. A superficial bladder TCC was demonstrated on CT and subsequently confirmed on histology. No other primary neoplasm was found on full-body imaging. The neurological symptoms were considered to be an antibody-mediated paraneoplastic neurological syndrome and improved after resection of the tumour. Discussion. The association of anti-Hu positive paraneoplastic neurological syndrome and TCC has not been described in the literature previously. We emphasize the need for detailed clinical examination and the importance of a multidisciplinary thought process and encourage further awareness of this rare association.

  17. A bacterial signal peptidase enhances processing of a recombinant single chain antibody fragment in insect cells

    NARCIS (Netherlands)

    Ailor, E; Pathmanathan, J; Jongbloed, JDH; Betenbaugh, MJ

    1999-01-01

    The production of an antibody single chain fragment (scFv) in insect cells was accompanied by the formation of an insoluble intracellular precursor even with the inclusion of the bee melittin signal peptide. The presence of the precursor polypeptide suggests a limitation in the processing of the sig

  18. Erratum: Colorectal Cancer Cell Surface Protein Profiling Using an Antibody Microarray and Fluorescence Multiplexing.

    Science.gov (United States)

    2015-01-01

    The author's email has been corrected in the publication of Colorectal Cancer Cell Surface Protein Profiling Using an Antibody Microarray and Fluorescence Multiplexing. There was an error with the author, Jerry Zhou's, email. The author's email has been updated to: j.zhou@uws.edu.au from: jzho7551@mail.usyd.edu.au. PMID:26167960

  19. A single-domain antibody-linked Fab bispecific antibody Her2-S-Fab has potent cytotoxicity against Her2-expressing tumor cells.

    Science.gov (United States)

    Li, Aifen; Xing, Jieyu; Li, Li; Zhou, Changhua; Dong, Bin; He, Ping; Li, Qing; Wang, Zhong

    2016-12-01

    Her2, which is frequently overexpressed in breast cancer, is one of the most studied tumor-associated antigens for cancer therapy. Anti-HER2 monoclonal antibody, trastuzumab, has achieved significant clinical benefits in metastatic breast cancer. In this study, we describe a novel bispecific antibody Her2-S-Fab targeting Her2 by linking a single domain anti-CD16 VHH to the trastuzumab Fab. The Her2-S-Fab antibody can be efficiently expressed and purified from Escherichia coli, and drive potent cancer cell killing in HER2-overexpressing cancer cells. In xenograft model, the Her2-S-Fab suppresses tumor growth in the presence of human immune cells. Our results suggest that the bispecific Her2-S-Fab may provide a valid alternative to Her2 positive cancer therapy. PMID:27112931

  20. Monoclonal antibodies against goldfish (Carassius auratus) immunoglobulin: application to the quantification of immunoglobulin and antibody-secreting cells by ELISPOT and seric immunoglobulin and antibody levels by ELISA in carp (Cyprinus carpio).

    Science.gov (United States)

    Siwicki, A K; Vergnet, C; Charlemagne, J; Dunier, M

    1994-01-01

    Monoclonal antibodies (mAbs) raised against heavy and light chains of goldfish immunoglobulin (Ig) were characterized by a Western blot technique. A complete cross-reactivity was observed between carp and goldfish Ig. These mAbs were used for the quantification of carp Ig and anti-Yersinia ruckeri antibodies by ELISA. An ELISPOT assay was also developed in carp to quantify Ig-secreting cells (ISC) and antibody-secreting cells (ASC). The number of ASC was maximum on day 18 post-vaccination and decreased to the basal level on day 28. The antibody levels in sera were maximum on day 18 and slowly decreased until day 28. PMID:7951348

  1. Cumulative Doses of T-Cell Depleting Antibody and Cancer Risk after Kidney Transplantation

    Science.gov (United States)

    Chen, Jenny H. C.; Wong, Germaine; Chapman, Jeremy R.; Lim, Wai H.

    2015-01-01

    T-cell depleting antibody is associated with an increased risk of cancer after kidney transplantation, but a dose-dependent relationship has not been established. This study aimed to determine the association between cumulative doses of T-cell depleting antibody and the risk of cancer after kidney transplantation. Using data from the Australian and New Zealand Dialysis and Transplant Registry between 1997–2012, we assessed the risk of incident cancer and cumulative doses of T-cell depleting antibody using adjusted Cox regression models. Of the 503 kidney transplant recipients with 2835 person-years of follow-up, 276 (55%), 209 (41%) and 18 (4%) patients received T-cell depleting antibody for induction, rejection or induction and rejection respectively. The overall cancer incidence rate was 1,118 cancers per 100,000 patient-years, with 975, 1093 and 1377 cancers per 100,000 patient-years among those who had received 1–5 doses, 6–10 doses and >10 doses, respectively. There was no association between cumulative doses of T cell depleting antibody and risk of incident cancer (1–5: referent, 6–10: adjusted hazard ratio (HR) 1.19, 95%CI 0.48–2.95, >10: HR 1.42, 95%CI 0.50–4.02, p = 0.801). This lack of association is contradictory to our hypothesis and is likely attributed to the low event rates resulting in insufficient power to detect significant differences. PMID:26555791

  2. Gamma-aminobutyric-acid-B receptor antibodies in limbic encephalitis with small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Ke-Qin Liu

    2015-01-01

    Full Text Available Encephalitis associated with antibodies to gamma-aminobutyric-acid B (GABA-B is a subgroup of autoimmune synaptic encephalitis with typical features of limbic encephalitis and small cell lung cancer (SCLC. We report a case of anti-GABA-B receptor encephalitis in a 57-year-old man who presented with seizures, memory loss, and abnormal behavior. He developed partially neurological responses to immunotherapy, but refused comprehensive tumor screening. The symptoms were aggravated again 4 months later. Workup showed antibodies to GABA-B receptors and tumor screening revealed SCLC. It highlights the importance of early screening of underlying tumor and anti-tumor treatment in paraneoplastic cases.

  3. Endothelial cell activation by antiphospholipid antibodies is modulated by Krüppel-like transcription factors

    OpenAIRE

    Allen, Kristi L.; Hamik, Anne; Jain, Mukesh K.; McCrae, Keith R

    2011-01-01

    Antiphospholipid syndrome is characterized by thrombosis and/or recurrent pregnancy loss in the presence of antiphospholipid antibodies (APLAs). The majority of APLAs are directed against phospholipid-binding proteins, particularly β2-glycoprotein I (β2GPI). Anti-β2GPI antibodies activate endothelial cells in a β2GPI-dependent manner through a pathway that involves NF-κB. Krüppel-like factors (KLFs) play a critical role in regulating the endothelial response to inflammatory stimuli. We hypoth...

  4. Production and characterization of monoclonal antibodies to cell wall antigens of Aspergillus fumigatus.

    OpenAIRE

    Ste-Marie, L; Sénéchal, S; Boushira, M; Garzon, S.; Strykowski, H; Pedneault, L; de Repentigny, L

    1990-01-01

    Two murine monoclonal antibodies (MAbs) against Aspergillus fumigatus were produced and characterized. Splenocytes from cell wall-immunized BALB/c mice were fused with SP2/0 myeloma cells. The hybridomas were screened with a cold alkali (CA) extract of mycelium containing protein, mannose, and galactose, and two MAbs of the immunoglobulin M class were purified from ascites fluid. MAbs 1 and 40 were characterized by double immunodiffusion against CA antigen, indirect enzyme immunoassay with ma...

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

    OpenAIRE

    Sexton, M; Reen, D J

    1992-01-01

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

  7. Human colonic goblet cells. Demonstration of distinct subpopulations defined by mucin-specific monoclonal antibodies.

    OpenAIRE

    Podolsky, D K; Fournier, D A; Lynch, K E

    1986-01-01

    We studied glycoprotein content of human colonic goblet cells, using a library of monoclonal antibodies (MAbs) directed against purified human colonic mucin (HCM). Using indirect immunofluorescence (IIF), we found that 17 of 23 anti-HCM MAbs stained some or all goblet cells of normal human colonic mucosa. We observed a variety of cellular staining patterns, including (a) diffuse (homogeneous) staining of intracellular mucin, (b) speckled (inhomogeneous) staining of mucin droplets, (c) periphe...

  8. Sensitivity of immunofluorescence with monoclonal antibodies for detection of Chlamydia trachomatis inclusions in cell culture.

    OpenAIRE

    Stephens, R S; Kuo, C C; Tam, M R

    1982-01-01

    Monoclonal antibodies which recognize the species-specific major outer membrane protein antigen of Chlamydia trachomatis were used for immunofluorescence staining of chlamydial inclusions in cell culture. A total of 115 clinical specimens were inoculated onto replicate HeLa 229 cell monolayers and assayed for chlamydial inclusions by immunofluorescence staining and Giemsa staining. Of the isolates, 38 were detected by immunofluorescence staining on passage 1 and 1 was detected on passage 2; 2...

  9. Targeting of a plasma cell line with a conjugate containing xanthine oxidase and the monoclonal antibody 62B1.

    Science.gov (United States)

    Tazzari, P L; Battelli, M G; Abbondanza, A; Dinota, A; Rizzi, S; Gobbi, M; Stirpe, F

    1989-07-01

    We report on the preparation of an antibody-conjugated enzyme consisting of xanthine oxidase, a free-radical-producing enzyme, linked to the 62B1 monoclonal antibody, which recognizes the last steps of differentiation of B cell lineage (plasma cell and hairy cells). The conjugate specifically kills target cells, retaining both enzymic and immunological properties, without any damage to normal myeloid clonogenic efficiency. The model is suitable for ex vivo bone marrow purging in multiple myeloma patients. PMID:2787552

  10. Nippostrongylus brasiliensis: radioresistant IgE antibody-forming cells in infected rats

    International Nuclear Information System (INIS)

    In Nippostrongylus brasiliensis-infected rats, anti-N. brasiliensis IgE antibody production was observed at 20 weeks postinfection, long after the worms, as a source of antigen, had been expelled. The persistent IgE production was not abrogated after whole body irradiation (800 R) administered at 12 or 20 weeks, suggesting the participation of radioresistant IgE-forming cells. Help of T cells and recruitment of B memory cells in the irradiated rats seems to be ruled out by the findings that the irradiation completely inhibited the initiation of anti-N. brasiliensis IgE production in rats shortly after the infection with N. brasiliensis or after primary and secondary immunization with N. brasiliensis-antigen. Moreover, clearance of anti-N. brasiliensis IgE antibody from circulation did not seem to be crucially affected by the irradiation. The radioresistant cells forming anti-N. brasiliensis IgE were most productive in mesenteric lymph nodes as compared to other lymph nodes. The recognition of antigens fractionated by chromatography on Sephadex G-200 was the same for IgE-forming cells from rats 12 weeks after infection as for those from 3 weeks after infection. Based on these results, one of the mechanisms of persistent elevation of IgE antibody in the host infected with helminth parasites might be explained by the participation of radioresistant IgE-forming cells

  11. Nippostrongylus brasiliensis: radioresistant IgE antibody-forming cells in infected rats

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, N.; Kobayashi, A.

    1989-02-01

    In Nippostrongylus brasiliensis-infected rats, anti-N. brasiliensis IgE antibody production was observed at 20 weeks postinfection, long after the worms, as a source of antigen, had been expelled. The persistent IgE production was not abrogated after whole body irradiation (800 R) administered at 12 or 20 weeks, suggesting the participation of radioresistant IgE-forming cells. Help of T cells and recruitment of B memory cells in the irradiated rats seems to be ruled out by the findings that the irradiation completely inhibited the initiation of anti-N. brasiliensis IgE production in rats shortly after the infection with N. brasiliensis or after primary and secondary immunization with N. brasiliensis-antigen. Moreover, clearance of anti-N. brasiliensis IgE antibody from circulation did not seem to be crucially affected by the irradiation. The radioresistant cells forming anti-N. brasiliensis IgE were most productive in mesenteric lymph nodes as compared to other lymph nodes. The recognition of antigens fractionated by chromatography on Sephadex G-200 was the same for IgE-forming cells from rats 12 weeks after infection as for those from 3 weeks after infection. Based on these results, one of the mechanisms of persistent elevation of IgE antibody in the host infected with helminth parasites might be explained by the participation of radioresistant IgE-forming cells.

  12. Engineering cholesterol-based fibers for antibody immobilization and cell capture

    Science.gov (United States)

    Cohn, Celine

    In 2015, the United States is expected to have nearly 600,000 deaths attributed to cancer. Of these 600,000 deaths, 90% will be a direct result of cancer metastasis, the spread of cancer throughout the body. During cancer metastasis, circulating tumor cells (CTCs) are shed from primary tumors and migrate through bodily fluids, establishing secondary cancer sites. As cancer metastasis is incredibly lethal, there is a growing emphasis on developing "liquid biopsies" that can screen peripheral blood, search for and identify CTCs. One popular method for capturing CTCs is the use of a detection platform with antibodies specifically suited to recognize and capture cancer cells. These antibodies are immobilized onto the platform and can then bind and capture cells of interest. However, current means to immobilize antibodies often leave them with drastically reduced function. The antibodies are left poorly suited for cell capture, resulting in low cell capture efficiencies. This body of work investigates the use of lipid-based fibers to immobilize proteins in a way that retains protein function, ultimately leading to increased cell capture efficiencies. The resulting increased efficiencies are thought to arise from the retained three-dimensional structure of the protein as well as having a complete coating of the material surface with antibodies that are capable of interacting with their antigens. It is possible to electrospin cholesterol-based fibers that are similar in design to the natural cell membrane, providing proteins a more natural setting during immobilization. Such fibers have been produced from cholesterol-based cholesteryl succinyl silane (CSS). These fibers have previously illustrated a keen aptitude for retaining protein function and increasing cell capture. Herein the work focuses on three key concepts. First, a model is developed to understand the immobilization mechanism used by electrospun CSS fibers. The antibody immobilization and cell capturing

  13. Induction of ICOS+CXCR3+CXCR5+ TH Cells Correlates with Antibody Responses to Influenza Vaccination

    Science.gov (United States)

    Bentebibel, Salah-Eddine; Lopez, Santiago; Obermoser, Gerlinde; Schmitt, Nathalie; Mueller, Cynthia; Harrod, Carson; Flano, Emilio; Mejias, Asuncion; Albrecht, Randy A.; Blankenship, Derek; Xu, Hui; Pascual, Virginia; Banchereau, Jacques; Garcia-Sastre, Adolfo; Palucka, Anna Karolina; Ramilo, Octavio; Ueno, Hideki

    2013-01-01

    Seasonal influenza vaccine protects 60 to 90% of healthy young adults from influenza infection. The immunological events that lead to the induction of protective antibody responses remain poorly understood in humans. We identified the type of CD4+ T cells associated with protective antibody responses after seasonal influenza vaccinations. The administration of trivalent split-virus influenza vaccines induced a temporary increase of CD4+ T cells expressing ICOS, which peaked at day 7, as did plasmablasts. The induction of ICOS was largely restricted to CD4+ T cells co-expressing the chemokine receptors CXCR3 and CXCR5, a subpopulation of circulating memory T follicular helper cells. Up to 60% of these ICOS+CXCR3+CXCR5+CD4+ T cells were specific for influenza antigens and expressed interleukin-2 (IL-2), IL-10, IL-21, and interferon-γ upon antigen stimulation. The increase of ICOS+CXCR3+CXCR5+CD4+ T cells in blood correlated with the increase of preexisting antibody titers, but not with the induction of primary antibody responses. Consistently, purified ICOS+CXCR3+CXCR5+CD4+ T cells efficiently induced memory B cells, but not naïve B cells, to differentiate into plasma cells that produce influenza-specific antibodies ex vivo. Thus, the emergence of blood ICOS+CXCR3+CXCR5+CD4+ T cells correlates with the development of protective antibody responses generated by memory B cells upon seasonal influenza vaccination. PMID:23486778

  14. REAL-Select: full-length antibody display and library screening by surface capture on yeast cells.

    Directory of Open Access Journals (Sweden)

    Laura Rhiel

    Full Text Available We describe a novel approach named REAL-Select for the non-covalent display of IgG-molecules on the surface of yeast cells for the purpose of antibody engineering and selection. It relies on the capture of secreted native full-length antibodies on the cell surface via binding to an externally immobilized ZZ domain, which tightly binds antibody Fc. It is beneficial for high-throughput screening of yeast-displayed IgG-libraries during antibody discovery and development. In a model experiment, antibody-displaying yeast cells were isolated from a 1:1,000,000 mixture with control cells confirming the maintenance of genotype-phenotype linkage. Antibodies with improved binding characteristics were obtained by affinity maturation using REAL-Select, demonstrating the ability of this system to display antibodies in their native form and to detect subtle changes in affinity by flow cytometry. The biotinylation of the cell surface followed by functionalization with a streptavidin-ZZ fusion protein is an approach that is independent of the genetic background of the antibody-producing host and therefore can be expected to be compatible with other eukaryotic expression hosts such as P. pastoris or mammalian cells.

  15. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production

    OpenAIRE

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C.; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1 −/− mice limits...

  16. Enhancement of Antibody Titre and Development of Additional Red Cell Alloantibodies Following Intrauterine Transfusion.

    Science.gov (United States)

    Dubey, Anju; Sonker, Atul; Chaudhary, Rajendra

    2016-03-01

    Intrauterine blood transfusion is the mainstay of managing foetuses with severe anemia. It may however result in fetomaternal hemorrhage, which in cases of Rh isoimmunisation may increase the severity of the disease by enhancing the maternal immunological response to fetal antigens. This study was conducted to determine the frequency, specificity and origin of additional red cell antibodies which developed after IUT. The change in the titre of allo anti-D following IUT was also determined. Antibody detection and titration was done on the blood samples of all the patients before and after intrauterine blood transfusion to check for the development of additional antibody and change in the titre of existing anti-D. Severe anemia was found in 17 (58.6 %) fetuses who received a total of 42 ultrasound-guided IUTs. Development of antibodies additional to anti-D in maternal serum was seen in 5 (29.4 %) cases. The specificity of additional alloantibodies was anti-C in four cases whereas it was anti-E in one case. Four fold or greater increase in existing allo-anti D titre was seen in 6 (35.3 %) cases after IUT. Enhancement of maternal sensitisation leading to an increase in maternal antibody titre is particularly seen after the first IUT. Matching of the donor RBCs particularly for Rh antigens might prevent the induction of additional alloantibodies against these antigens. IUT as a treatment modality should be given judiciously and only when the need is inevitable. PMID:26855513

  17. Production of the recombinant single chain anti-B cell lymphoma antibody and evaluation of immunoreactivity

    International Nuclear Information System (INIS)

    Recombinant ScFv lym-1 was produced, using pET vector system for large scale production. ScFv lym-1 gene inserted pET-22b (+) vector, was expressed in E. coli BL-21 strain. ScFv lym-1 antibody extracted from periplasm, was purified with His-Taq column. To evaluated immunoreactivity with Raji cell, ScFv lym-1 was labeled with I-125 and I-125 ScFv lym-1 was purified with desalting column. Raji cell was injected into the C57BR/cdJ SCID mice. Gamma camera imaging were taken time point at 1, 8, 24 and 48 hr with 8 mm pinhole collimator. An active scFv lym-1 could be produced in E. coli with soluble from using pET vector system. Immunoreactivity and affinity constant of lgG lym-1 were 54% and 1.83 x 109 M-1, respectively, and those of scFv lym-1 were 53.7% and 1.46 x 109 M-1, respectively. Biodistribution of I-125 scFv lym-1 antibody showed faster clearance in blood, spleen, kidney and than I-125 lgG lym-1 antibody. Gamma camera image of I-125 scFv lym-1 antibody showed faster clearance and tumor targeting liver than I-125 lgG lym-1 antibody. In vitro properties of scFv lym-1 were similar to those of lgG lym-1. ScFv lym-1 showed faster blood clearance than lgG lym-1. These results suggest that scFv lym-1 antibody can be useful for tumor imaging agent

  18. Interaction of anti-phospholipid antibodies with late endosomes of human endothelial cells.

    Science.gov (United States)

    Galve-de Rochemonteix, B; Kobayashi, T; Rosnoblet, C; Lindsay, M; Parton, R G; Reber, G; de Maistre, E; Wahl, D; Kruithof, E K; Gruenberg, J; de Moerloose, P

    2000-02-01

    Anti-phospholipid antibodies (APLAs) are associated with thrombosis and/or recurrent pregnancy loss. APLAs bind to anionic phospholipids directly or indirectly via a cofactor such as beta(2)-glycoprotein 1 (beta(2)GPI). The lipid target of APLA is not yet established. Recently, we observed that APLAs in vitro can bind lysobisphosphatidic acid (LBPA). The internal membranes of late endosomes are enriched in this phospholipid. The current study was undertaken to determine to what extent binding of APLA to LBPA is correlated with binding to cardiolipin and to beta(2)GPI and to determine whether patient antibodies interact with late endosomes of human umbilical vein endothelial cells (HUVECs) and thus modify the intracellular trafficking of proteins. Binding of patient immunoglobulin G (n=37) to LBPA was correlated significantly with binding to cardiolipin. Although LBPA binding was correlated to a lesser extent with beta(2)GPI binding, we observed that beta(2)GPI binds with high affinity to LBPA. Immunofluorescence studies showed that late endosomes of HUVECs contain LBPA. Patient but not control antibodies recognized late endosomes, but not cardiolipin-rich mitochondria, even when we used antibodies that were immunopurified on cardiolipin. Incubation of HUVECs with patient plasma samples immunoreactive toward LBPA resulted in an accumulation of the antibodies in late endosomes and led to a redistribution of the insulinlike growth factor 2/mannose-6-phosphate receptor from the Golgi apparatus to late endosomes. Our results suggest that LBPA is an important lipid target of APLA in HUVECs. These antibodies are internalized by the cells and accumulate in late endosomes. By modifying the intracellular trafficking of proteins, APLA could contribute to several of the proposed pathogenic mechanisms leading to the antiphospholipid syndrome. PMID:10669657

  19. Red blood cell antibodies in pregnancy and their clinical consequences

    DEFF Research Database (Denmark)

    Nordvall, Maria; Dziegiel, Morten Hanefeld; Hegaard, Hanne Kristine;

    2009-01-01

    The objective was to determine clinical consequences of various specificities for the infant/fetus. The population was patients referred between 1998 and 2005 to the tertiary center because of detected red blood cell (RBC) alloimmunization. Altogether 455 infants were delivered by 390 alloimmunized...

  20. Identification of internalizing human single chain antibodies targeting brain tumor sphere cells

    Science.gov (United States)

    Zhu, Xiaodong; Bidlingmaier, Scott; Hashizume, Rintaro; James, C. David; Berger, Mitchel S.; Liu, Bin

    2010-01-01

    Glioblastoma multiforme (GBM) is the most common and aggressive form of primary brain tumor and there is no curative treatment to date. Resistance to conventional therapies and tumor recurrence pose major challenges to treatment and management of this disease, and therefore new therapeutic strategies need to be developed. Previous studies by other investigators have shown that a subpopulation of GBM cells can grow as neurosphere-like cells when cultured in restrictive media, and exhibit enhanced tumor initiating ability and resistance to therapy. We report here the identification of internalizing human single chain antibodies (scFvs) targeting GBM tumor sphere cells. We selected a large naive phage antibody display library on the glycosylation-dependent CD133 epitope-positive subpopulation of GBM cells grown as tumor spheres and identified internalizing scFvs that target tumor sphere cells broadly, as well as scFvs that target the CD133 positive subpopulation. These scFvs were found to be efficiently internalized by GBM tumor sphere cells. One scFv GC4 inhibited self-renewal of GBM tumor sphere cells in vitro. We have further developed a full-length human IgG1 based on this scFv and found that it potently inhibits proliferation of GBM tumor sphere cells and GBM cells grown in regular non-selective media. Taken together, these results show that internalizing human scFvs targeting brain tumor sphere cells can be readily identified from a phage antibody display library, which could be useful for further development of novel therapies that target subpopulations of GBM cells to combat recurrence and resistance to treatment. PMID:20587664

  1. Rabbit antibodies to the cell wall polysaccharide of Streptococcus pneumoniae fail to protect mice from lethal challenge with encapsulated pneumococci.

    OpenAIRE

    Szu, S C; Schneerson, R; Robbins, J B

    1986-01-01

    A conjugate, composed of the cell wall polysaccharide (C polysaccharide) of Streptococcus pneumoniae and bovine serum albumin (BSA), was prepared with the bifunctional agent N-succinimidyl-3-(2-pyridyldithio)-propionate. Analysis with monoclonal antibodies provided evidence that the phosphocholine (PC) moiety of the C polysaccharide was retained during the conjugation procedure. The C polysaccharide-BSA conjugate elicited antibodies to C polysaccharide in rabbits; no PC-specific antibodies we...

  2. Localization of the catalytic subunit of cyclic AMP-dependent. Protein kinase in cultured cells using a specific antibody

    OpenAIRE

    1982-01-01

    We developed a specific antibody to the catalytic subunit (C-subunit) of cyclic AMP-dependent protein kinase and used it to localize C- subunit in cultured cells. C-subunit antigen was purified from bovine cardiac muscle and cross-linked to hemocyanin with glutaraldehyde. Immunized goat serum showed a low titer of antibody after boosting; it was enriched 100-fold by affinity chromatography on catalytic subunit- Sepharose. The antibody immunoprecipitated C-subunit from type I and type II holoe...

  3. Role of group 3 innate lymphoid cells in antibody production

    OpenAIRE

    Magri, Giuliana; Cerutti, Andrea

    2015-01-01

    Innate lymphoid cells (ILCs) constitute a heterogeneous family of effector lymphocytes of the innate immune system that mediate lymphoid organogenesis, tissue repair, immunity and inflammation. The initial view that ILCs exert their protective functions solely during the innate phase of an immune response has been recently challenged by evidence indicating that ILCs shape adaptive immunity by establishing both contactdependent and contact-independent interactions with multiple ...

  4. A 125I-protein A-binding assay detecting antibodies to cell surface antigens

    International Nuclear Information System (INIS)

    A 125I-protein A-binding assay detecting antibodies to cell surface antigens on human blood cells was developed and evaluated using sera from multitransfused nonleukemic patients sensitized against HLA antigens. The binding assay was found to be reproducible and more sensitive than conventional HLA testing. Seven patients with acute myelogenous leukemia and two patients with acute lymphoblastic leukemia successfully treated by chemotherapy were than investigated. Sera from seven of the patients studied in partial or complete remission demonstrated significant binding to autochthonous leukemic cells obtained from bone marrow or peripheral blood. In two cases sera taken during the leukemic stage demonstrated the most pronounced binding to the patients' own leukemic cells. Sera from four patients with demonstrable significant binding to autochthonous leukemic cells failed to bind to autochthonous remission cells when both types of target cells were tested in parallel. Differences in serum concentrations of IgG, IgA, and IgM were not the cause of the demonstrated increased binding of leukemic sera to autochthonous target cells. We propose that the 125I-protein A-binding assay presented in this paper detects antibodies reacting selectively with acute leukemia cells. (orig.)

  5. Expression of Receptors for Tetanus Toxin and Monoclonal Antibody A2B5 by Pancreatic Islet Cells

    Science.gov (United States)

    Eisenbarth, G. S.; Shimizu, K.; Bowring, M. A.; Wells, S.

    1982-08-01

    Studies of the reaction of antibody A2B5 and tetanus toxin with pancreatic islet cells, islet cell tumors, and other human amine precursor uptake and decarboxylation (APUD) tumors are described. By indirect immunofluorescence, antibody A2B5 and tetanus toxin were shown to specifically bind to the plasma membrane of human, rat, chicken, and mouse islet cells. The binding of antibody A2B5 to the cell surface of living islet cells has allowed isolation of these cells from a suspension of pancreatic cells by using a fluorescence-activated cell sorter. In studies designed to determine whether tetanus toxin and antibody A2B5 bound to the same surface antigen, A2B5 and tetanus toxin did not compete for binding to normal islet cells, a human islet cell tumor, or a rat islet cell tumor. In addition to binding to islet cell tumors, antibody A2B5 reacts with frozen sections, isolated cells, and cell lines of neural, neural crest, and APUD origin.

  6. T cell-independent type I antibody response against B cell epitopes expressed repetitively on recombinant virus particles

    OpenAIRE

    Fehr, Thomas; Skrastina, Dace; Pumpens, Paul; Zinkernagel, Rolf M.

    1998-01-01

    Recombinant viral or virus-like particles offer new tools for vaccine development. This study investigated hepatitis B core antigen (HBcAg) capsids and RNA phage Qβ coats as carriers of a foreign epitope to induce antibody responses in mice. HBcAg capsids were shown to induce T cell-independent (TI) antibodies. We found that these particles behave as antigen-specific TI type 1 (TI-1) Ag comparable to other rigidly structured viruses. When a 5-aa long epitope of the pre-S1 domain of hepatitis ...

  7. Cellular cooperation during in vivo anti-hapten antibody responses. I. The effect of cell number on the response

    International Nuclear Information System (INIS)

    Cellular interactions in adoptive secondary anti-hapten antibody responses to the hapten 2,4-dinitrophenyl (DNP) have been studied. It was shown that DNP-specific B cells must interact with carrier specific helper T cells to give optimal responses. Independent titration of B cell and helper cell activity in adoptive anti-DNP antibody responses gave the following results: Doubling the number of transferred B cells approximately doubled the subsequent antibody response. Doubling the number of helper cells leads to nearly 4 times as much anti-DNP antibody, measured 7 days after boosting (''premium effect''). This marked effect of helper cell number on the antibody response is thought to be due primarily to the interaction of two populations of carrier-specific cells in the helper effect, or to the interaction of two activities of a single population of helper cells, namely clone activation and clone expansion. Only a very small proportion of the premium effect given by helper cells could be attributed to increases in antibody affinity. (U.S.)

  8. Study on the Radioiodination of Sheep Anti-myeloma Polyclonal Antibodies for the Determination of in-vitro Cytotoxic Effect on Myeloma Cells

    International Nuclear Information System (INIS)

    The present work aims to study the effect of radiolabeled anti-myeloma polyclonal antibodies on the growth and viability of myeloma cells in-vitro. Two Sheep were immunized by myeloma cells (SP2/OR) as antigen. Productions of Sheep anti-myeloma polyclonal antibodies followed by radioiodination using different oxidizing agents were carried out. Labeled and unlabeled antibodies were incubated with myeloma cells. Growth and viability of myeloma cells were investigated before and after addition of antibodies. The results show significant reduction in growth and viability of myeloma cells by using labeled antibodies. This technique of treatment can be used in radio-immunotherapy of myeloma cell

  9. Antibody-Conjugated Paramagnetic Nanobeads: Kinetics of Bead-Cell Binding

    Directory of Open Access Journals (Sweden)

    Shahid Waseem

    2014-05-01

    Full Text Available Specific labelling of target cell surfaces using antibody-conjugated paramagnetic nanobeads is essential for efficient magnetic cell separation. However, studies examining parameters determining the kinetics of bead-cell binding are scarce. The present study determines the binding rates for specific and unspecific binding of 150 nm paramagnetic nanobeads to highly purified target and non-target cells. Beads bound to cells were enumerated spectrophotometrically. Results show that the initial bead-cell binding rate and saturation levels depend on initial bead concentration and fit curves of the form A(1 − exp(−kt. Unspecific binding within conventional experimental time-spans (up to 60 min was not detectable photometrically. For CD3-positive cells, the probability of specific binding was found to be around 80 times larger than that of unspecific binding.

  10. Rational development of high-affinity T-cell receptor-like antibodies.

    Science.gov (United States)

    Stewart-Jones, Guillaume; Wadle, Andreas; Hombach, Anja; Shenderov, Eugene; Held, Gerhard; Fischer, Eliane; Kleber, Sascha; Nuber, Natko; Stenner-Liewen, Frank; Bauer, Stefan; McMichael, Andrew; Knuth, Alexander; Abken, Hinrich; Hombach, Andreas A; Cerundolo, Vincenzo; Jones, E Yvonne; Renner, Christoph

    2009-04-01

    T-cell interaction with a target cell is a key event in the adaptive immune response and primarily driven by T-cell receptor (TCR) recognition of peptide-MHC (pMHC) complexes. TCR avidity for a given pMHC is determined by number of MHC molecules, availability of coreceptors, and TCR affinity for MHC or peptide, respectively, with peptide recognition being the most important factor to confer target specificity. Here we present high-resolution crystal structures of 2 Fab antibodies in complex with the immunodominant NY-ESO-1(157-165) peptide analogue (SLLMWITQV) presented by HLA-A*0201 and compare them with a TCR recognizing the same pMHC. Binding to the central methionine-tryptophan peptide motif and orientation of binding were almost identical for Fabs and TCR. As the MW "peg" dominates the contacts between Fab and peptide, we estimated the contributions of individual amino acids between the Fab and peptide to provide the rational basis for a peptide-focused second-generation, high-affinity antibody library. The final Fab candidate achieved better peptide binding by 2 light-chain mutations, giving a 20-fold affinity improvement to 2-4 nM, exceeding the affinity of the TCR by 1,000-fold. The high-affinity Fab when grafted as recombinant TCR on T cells conferred specific killing of HLA-A*0201/NY-ESO-1(157-165) target cells. In summary, we prove that affinity maturation of antibodies mimicking a TCR is possible and provide a strategy for engineering high-affinity antibodies that can be used in targeting specific pMHC complexes for diagnostic and therapeutic purposes. PMID:19307587

  11. Monoclonal antibodies against ROR1 induce apoptosis of chronic lymphocytic leukemia (CLL) cells.

    Science.gov (United States)

    Daneshmanesh, A H; Hojjat-Farsangi, M; Khan, A S; Jeddi-Tehrani, M; Akhondi, M M; Bayat, A A; Ghods, R; Mahmoudi, A-R; Hadavi, R; Österborg, A; Shokri, F; Rabbani, H; Mellstedt, H

    2012-06-01

    ROR1 is a receptor tyrosine kinase (RTK) recently identified to be overexpressed at the gene and protein levels in chronic lymphocytic leukemia (CLL). Monoclonal antibodies (MAbs) against RTKs have been successfully applied for therapy of solid tumors. We generated five MAbs against the Ig (n = 1), cysteine-rich (CRD) (n = 2) and kringle (KNG) (n = 2) domains, respectively, of the extracellular part of ROR1. All CLL patients (n = 20) expressed ROR1 on the surface of the leukemic cells. A significantly higher frequency of ROR1 expression was found in patients with progressive versus non-progressive disease, and in those with unmutated versus mutated IgVH genes. All five MAbs alone induced apoptosis in the absence of complement or added effector cells (Annexin-V and MTT, as well as cleavage of poly-(ADP ribose)-polymerase, caspase-8 and caspase-9) of CLL cells but not of normal B cells. Most effective were MAbs against CRD and KNG, significantly superior to rituximab (P < 0.005). Cross-linking of anti-ROR1 MAbs using the F(ab')(2) fragments of anti-Fc antibodies significantly augmented apoptosis. Two of the MAbs induced complement-dependent cytotoxicity (CDC) similar to that of rituximab and one anti-ROR1 MAb (KNG) (IgG1) showed killing activity by antibody-dependent cellular cytotoxicity. The identified ROR1 epitopes may provide a basis for generating human ROR1 MAbs for therapy. PMID:22289919

  12. Enhancement of monoclonal antibody production in CHO cells by exposure to He–Ne laser radiation

    OpenAIRE

    Ghaleb, Rana; Naciri, Mariam; Al-Majmaie, Rasoul; Maki, Amel; Al-Rubeai, Mohamed

    2013-01-01

    This study tested the effectiveness of laser biostimulation in small-scale cultures in vitro. We investigated the response of recombinant CHO cells, which are used for the production of monoclonal antibody, to low level laser radiation. The cells were irradiated using a 632.8 nm He–Ne laser in a continuous wave mode at different energy doses. We incubated the irradiated cells in small batch cultures and assessed their proliferation and productivity at various time intervals. Compared to untre...

  13. Neural stem cells harvested from live brains by antibody-conjugated magnetic nanoparticles.

    Science.gov (United States)

    Lui, C N P; Tsui, Y P; Ho, A S L; Shum, D K Y; Chan, Y S; Wu, C T; Li, H W; Tsang, S C Edman; Yung, K K L

    2013-11-18

    It stems from the magnetism: The extraction of stem/progenitor cells from the brain of live animals is possible using antibodies conjugated to magnetic nanoparticles (Ab-MNPs). The Ab-MNPs are introduced to a rat's brain with a superfine micro-syringe. The stem cells attach to the Ab-MNPs and are magnetically isolated and removed. They can develop into neurospheres and differentiate into different types of cells outside the subject body. The rat remains alive and healthy. PMID:24108547

  14. Benchmarking of commercially available CHO cell culture media for antibody production.

    Science.gov (United States)

    Reinhart, David; Damjanovic, Lukas; Kaisermayer, Christian; Kunert, Renate

    2015-06-01

    In this study, eight commercially available, chemically defined Chinese hamster ovary (CHO) cell culture media from different vendors were evaluated in batch culture using an IgG-producing CHO DG44 cell line as a model. Medium adaptation revealed that the occurrence of even small aggregates might be a good indicator of cell growth performance in subsequent high cell density cultures. Batch experiments confirmed that the culture medium has a significant impact on bioprocess performance, but high amino acid concentrations alone were not sufficient to ensure superior cell growth and high antibody production. However, some key amino acids that were limiting in most media could be identified. Unbalanced glucose and amino acids led to high cell-specific lactate and ammonium production rates. In some media, persistently high glucose concentrations probably induced the suppression of respiration and oxidative phosphorylation, known as Crabtree effect, which resulted in high cell-specific glycolysis rates along with a continuous and high lactate production. In additional experiments, two of the eight basal media were supplemented with feeds from two different manufacturers in six combinations, in order to understand the combined impact of media and feeds on cell metabolism in a CHO fed-batch process. Cell growth, nutrient consumption and metabolite production rates, antibody production, and IgG quality were evaluated in detail. Concentrated feed supplements boosted cell concentrations almost threefold and antibody titers up to sevenfold. Depending on the fed-batch strategy, fourfold higher peak cell concentrations and eightfold increased IgG titers (up to 5.8 g/L) were achieved. The glycolytic flux was remarkably similar among the fed-batches; however, substantially different specific lactate production rates were observed in the different media and feed combinations. Further analysis revealed that in addition to the feed additives, the basal medium can make a considerable

  15. Enhanced neutralization potency of botulinum neurotoxin antibodies using a red blood cell-targeting fusion protein.

    Directory of Open Access Journals (Sweden)

    Sharad P Adekar

    Full Text Available Botulinum neurotoxin (BoNT potently inhibits cholinergic signaling at the neuromuscular junction. The ideal countermeasures for BoNT exposure are monoclonal antibodies or BoNT antisera, which form BoNT-containing immune complexes that are rapidly cleared from the general circulation. Clearance of opsonized toxins may involve complement receptor-mediated immunoadherence to red blood cells (RBC in primates or to platelets in rodents. Methods of enhancing immunoadherence of BoNT-specific antibodies may increase their potency in vivo. We designed a novel fusion protein (FP to link biotinylated molecules to glycophorin A (GPA on the RBC surface. The FP consists of an scFv specific for murine GPA fused to streptavidin. FP:mAb:BoNT complexes bound specifically to the RBC surface in vitro. In a mouse model of BoNT neutralization, the FP increased the potency of single and double antibody combinations in BoNT neutralization. A combination of two antibodies with the FP gave complete neutralization of 5,000 LD50 BoNT in mice. Neutralization in vivo was dependent on biotinylation of both antibodies and correlated with a reduction of plasma BoNT levels. In a post-exposure model of intoxication, FP:mAb complexes gave complete protection from a lethal BoNT/A1 dose when administered within 2 hours of toxin exposure. In a pre-exposure prophylaxis model, mice were fully protected for 72 hours following administration of the FP:mAb complex. These results demonstrate that RBC-targeted immunoadherence through the FP is a potent enhancer of BoNT neutralization by antibodies in vivo.

  16. Mammalian Cell Culture Clarification: A Case Study Using Chimeric Anti-CEA Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Abol Hassan

    2011-12-01

    Full Text Available The extracellular expression of monoclonal antibodies (mAbs in mammalian cell culture provides both opportunities and restrictions for the design of robust harvest and clarification operations. With advances in cell culture media and cell lines, it is now possible to achieve high titers of over 5 g/l for mAbs. However, Mammalian cells are sensitive to breakage due to shear stress that can result in release of proteases and other host cell proteins (HCPs which eventually affects product stability and purity. There is larger number of mAbs undergoing clinical development and it has placed significant importance on platform technologies of process development. Generally, Centrifugation and microfiltration are the primary harvest techniques used in the industry and depth filtration is also used as a step operation on clarification. This study compares the unit operations; centrifugation, microfiltration and depth filtration for maximum recovery of monoclonal antibodies. The results have shown that the depth filtration as more suitable operation for mammalian cell culture clarification since it gives 96% recovery of mAbs in comparison to centrifugation and microfiltration. ABSTRAK: Pengungkapan luar sel dari antibodi monoklon (monoclonal antibodies ((mAbs dalam kultur sel mamalia memberi ruang dan batasan terhadap reka bentuk penuaian yang cekap dan penerangan operasi. Dengan kemajuan dalam media sel kultur dan cell lines (produk yang berupa sel kekal yang digunakan untuk tujuan kajian biologi, kini adalah berkemungkinan untuk memperolehi titer tinggi melebihi 5g/l untuk mAbs [2]. Walaupun begitu, sel mamalia sensitif terhadap retakan disebabkan tegasan ricih yang menyebabkan pengeluaran protease dan hos sel protein yang lain, (host cell proteins (HCPs akhirnya mempengaruhi kestabilan dan keaslian produk. Terdapat mAbs dalam jumlah besar yang masih menjalani pembangunan klinikal dan sesungguhnya ini penting sebagai satu landasan teknologi dalam

  17. CpG-A and B oligodeoxynucleotides enhance the efficacy of antibody therapy by activating different effector cell populations

    NARCIS (Netherlands)

    H.H. van Ojik; L. Bevaart; C.E. Dahle; A. Bakker (Annie); M.J.H. Jansen (Marco); M.J. van Vugt; J.G. van de Winkel; G.J. Weiner

    2003-01-01

    textabstractImmunostimulatory CpG oligodeoxynucleotides (ODNs) can enhance the therapeutic effect of monoclonal antibodies (mAbs) by enhancing antibody-dependent cell-mediated cytotoxicity (ADCC). Distinct classes of CpG ODNs have been found recently to stimulate different effector

  18. Antibody-independent control of gamma-herpesvirus latency via B cell induction of anti-viral T cell responses.

    OpenAIRE

    Kelly B McClellan; Shivaprakash Gangappa; Speck, Samuel H.; Herbert W Virgin

    2006-01-01

    Synopsis B cells can control virus infection by making specific antibodies that bind to virus and infected cells. However, it is unknown whether B cells perform other anti-viral functions to protect the host during infection. The authors addressed this question by infecting mice with murine γ-herpesvirus 68 (γHV68), a relative of Epstein-Barr virus and Kaposi's sarcoma associated virus, which establishes lifelong latent infection in mice. Mice lacking B cells (B cell−/−) failed to control lat...

  19. A recombinant antibody with the antigen-specific, major histocompatibility complex-restricted specificity of T cells

    DEFF Research Database (Denmark)

    Andersen, P S; Stryhn, A; Hansen, B E; Fugger, L; Engberg, J; Buus, S

    1996-01-01

    lead to novel approaches in immunotherapy. However, it has proven difficult to generate antibodies with the specificity of T cells by conventional hybridoma techniques. Here we report that the phage display technology is a feasible alternative to generate antibodies recognizing specific, predetermined......Specific recognition of peptide/major histocompatibility complex (MHC) molecule complexes by the T-cell receptor is a key reaction in the specific immune response. Antibodies against peptide/MHC complexes would therefore be valuable tools in studying MHC function and T-cell recognition and might...

  20. Thymus cells in myasthenia gravis selectively enhance production of anti-acetylcholine-receptor antibody by autologous blood lymphocytes

    International Nuclear Information System (INIS)

    We investigated the role of the thymus in 16 patients with myasthenia gravis without thymoma by studying the production of anti-acetylcholine-receptor antibody by thymic and blood lymphocytes cultured alone or together. In 10 responders (with the highest receptor-antibody titers in their plasma), cultured thymic cells spontaneously produced measurable receptor antibody. Receptor-antibody production by autologous blood lymphocytes was enhanced by the addition of responder's thymic cells, irradiated to abrogate antibody production and suppression (P<0.01). This enhancement was greater and more consistent than that by pokeweed mitogen; it depended on viable thymic cells, appeared to be selective for receptor antibody, and correlated with the ratio of thymic helper (OKT4-positive or OKT4+) to suppressor (OKT8+) T cells (P<0.01). These results suggest that myasthenic thymus contains cell-bound acetylcholine-receptor-like material or specific T cells (or both) that can aid receptor-antibody production. This may be relevant to the benefits of thymectomy in myasthenia and to the breakdown in self-tolerance in this and other autoimmune diseases

  1. Thymus cells in myasthenia gravis selectively enhance production of anti-acetylcholine-receptor antibody by autologous blood lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Newsom-Davis, J.; Willcox, N.; Calder, L.

    1981-11-26

    We investigated the role of the thymus in 16 patients with myasthenia gravis without thymoma by studying the production of anti-acetylcholine-receptor antibody by thymic and blood lymphocytes cultured alone or together. In 10 responders (with the highest receptor-antibody titers in their plasma), cultured thymic cells spontaneously produced measurable receptor antibody. Receptor-antibody production by autologous blood lymphocytes was enhanced by the addition of responder's thymic cells, irradiated to abrogate antibody production and suppression (P<0.01). This enhancement was greater and more consistent than that by pokeweed mitogen; it depended on viable thymic cells, appeared to be selective for receptor antibody, and correlated with the ratio of thymic helper (OKT4-positive or OKT4+) to suppressor (OKT8+) T cells (P<0.01). These results suggest that myasthenic thymus contains cell-bound acetylcholine-receptor-like material or specific T cells (or both) that can aid receptor-antibody production. This may be relevant to the benefits of thymectomy in myasthenia and to the breakdown in self-tolerance in this and other autoimmune diseases.

  2. DNA-templated antibody conjugation for targeted drug delivery to cancer cells

    DEFF Research Database (Denmark)

    Liu, Tianqiang

    2016-01-01

    state to get a good pharmacological performance. Recombinant antibody engineering with non-natural amino acids, or enzyme-mediated conjugation approaches (transglutaminase, Sortase A or endoglycosidase) have been reported for producing homogeneous antibody conjugates. However, these methods require......-templated organic synthesis due to the wide existence of the 3-histidine cluster in most wild-type proteins. In this thesis, three projects that relate to targeted drug delivery to cancer cells based on the DTPC method is described. The first project was a delivery system which uses transferrin as the targeting...... ligand and saporin (ribosome inactivating protein) as the warhead to achieve enhanced cellular uptake and cytotoxicity of saporin to transferrin receptor overexpressed cancer cell line. The transferrin-saporin conjugate complex are formed by linking the site-selective DNA-transferrin conjugates with mono...

  3. Determination of Mother Centriole Maturation in CPAP-Depleted Cells Using the Ninein Antibody

    OpenAIRE

    Lee, Miseon; Rhee, Kunsoo

    2015-01-01

    Background Mutations in centrosomal protein genes have been identified in a number of genetic diseases in brain development, including microcephaly. Centrosomal P4.1-associated protein (CPAP) is one of the causal genes implicated in primary microcephaly. We previously proposed that CPAP is essential for mother centriole maturation during mitosis. Methods We immunostained CPAP-depleted cells using the ninein antibody, which selectively detects subdistal appendages in mature mother centrioles. ...

  4. Anti-Erythropoietin Antibody Associated Pure Red Cell Aplasia Resolved after Liver Transplantation

    OpenAIRE

    Hung, Annie K.; Jennifer Guy; Behler, Caroline M.; Lee, Eugene E.

    2015-01-01

    Patients undergoing antiviral therapy for chronic hepatitis C often develop anemia secondary to ribavirin and interferon. Recombinant erythropoietin has been used to improve anemia associated with antiviral therapy and to minimize dose reductions, which are associated with decreased rates of sustained virologic response. A rare potential side effect of recombinant erythropoietin is anti-erythropoietin antibody associated pure red cell aplasia. In chronic kidney disease patients with this enti...

  5. The mouse B cell repertoire : antibody specificities and immunoglobulin (sub) class distribution

    OpenAIRE

    Hooijkaas, Herbert

    1985-01-01

    textabstractThe total number of different immunoglobulin (I g) molecules that the immune system produces is often called the antibody specificity repertoire orB cell repertoire (Chapter 1). This repertoire can be subdivided into three categories: the potential, the available and the actual repertoires. The potential repertoire is determined by the number, structure and mechanisms of expression of the germl ine genes encoding lg molecules plus the possible somatic variants derived from them an...

  6. N-Acetyl-D-glucosamine-coated polyamidoamine dendrimer modulates antibody formation via natural killer cell activation

    Czech Academy of Sciences Publication Activity Database

    Huliková, Katarína; Benson, Veronika; Svoboda, Jan; Šíma, Petr; Fišerová, Anna

    2009-01-01

    Roč. 9, č. 6 (2009), s. 792-799. ISSN 1567-5769 R&D Projects: GA ČR GA310/06/0477; GA AV ČR IAA500200509; GA AV ČR IAA500200620 Institutional research plan: CEZ:AV0Z50200510 Keywords : GlcNAc(8) * antibody formation * NK cells Subject RIV: EC - Immunology Impact factor: 2.214, year: 2009

  7. Detection of Chlamydia trachomatis inclusions in Mccoy cell cultures with fluorescein-conjugated monoclonal antibodies.

    OpenAIRE

    Stamm, W. E.; Tam, M; Koester, M; Cles, L

    1983-01-01

    We compared two methods for identification of Chlamydia trachomatis inclusions in McCoy cell monolayers: conventional iodine staining and immunofluorescence staining with monoclonal antibodies against the species-specific major outer membrane protein antigen of C. trachomatis. Among 878 urethral and cervical specimens tested in parallel, the immunofluorescence method detected eightfold more inclusions per monolayer, identified a higher proportion of positive specimens on first passage (98 ver...

  8. Anti-CD25 monoclonal antibody Fc variants differentially impact regulatory T cells and immune homeostasis.

    Science.gov (United States)

    Huss, David J; Pellerin, Alex F; Collette, Brian P; Kannan, Arun K; Peng, Liaomin; Datta, Abhishek; Wipke, Brian T; Fontenot, Jason D

    2016-07-01

    Interleukin-2 (IL-2) is a critical regulator of immune homeostasis through its non-redundant role in regulatory T (Treg) cell biology. There is major interest in therapeutic modulation of the IL-2 pathway to promote immune activation in the context of tumour immunotherapy or to enhance immune suppression in the context of transplantation, autoimmunity and inflammatory diseases. Antibody-mediated targeting of the high-affinity IL-2 receptor α chain (IL-2Rα or CD25) offers a direct mechanism to target IL-2 biology and is being actively explored in the clinic. In mouse models, the rat anti-mouse CD25 clone PC61 has been used extensively to investigate the biology of IL-2 and Treg cells; however, there has been controversy and conflicting data on the exact in vivo mechanistic function of PC61. Engineering antibodies to alter Fc/Fc receptor interactions can significantly alter their in vivo function. In this study, we re-engineered the heavy chain constant region of an anti-CD25 monoclonal antibody to generate variants with highly divergent Fc effector function. Using these anti-CD25 Fc variants in multiple mouse models, we investigated the in vivo impact of CD25 blockade versus depletion of CD25(+) Treg cells on immune homeostasis. We report that immune homeostasis can be maintained during CD25 blockade but aberrant T-cell activation prevails when CD25(+) Treg cells are actively depleted. These results clarify the impact of PC61 on Treg cell biology and reveal an important distinction between CD25 blockade and depletion of CD25(+) Treg cells. These findings should inform therapeutic manipulation of the IL-2 pathway by targeting the high-affinity IL-2R. PMID:27012310

  9. Metabolic analysis of antibody producing Chinese hamster ovary cell culture under different stresses conditions.

    Science.gov (United States)

    Badsha, Md Bahadur; Kurata, Hiroyuki; Onitsuka, Masayoshi; Oga, Takushi; Omasa, Takeshi

    2016-07-01

    Chinese hamster ovary (CHO) cells are commonly used as the host cell lines concerning their ability to produce therapeutic proteins with complex post-translational modifications. In this study, we have investigated the time course extra- and intracellular metabolome data of the CHO-K1 cell line, under a control and stress conditions. The addition of NaCl and trehalose greatly suppressed cell growth, where the maximum viable cell density of NaCl and trehalose cultures were 2.2-fold and 2.8-fold less than that of a control culture. Contrariwise, the antibody production of both the NaCl and trehalose cultures was sustained for a longer time to surpass that of the control culture. The NaCl and trehalose cultures showed relatively similar dynamics of cell growth, antibody production, and substrate/product concentrations, while they indicated different dynamics from the control culture. The principal component analysis of extra- and intracellular metabolome dynamics indicated that their dynamic behaviors were consistent with biological functions. The qualitative pattern matching classification and hierarchical clustering analyses for the intracellular metabolome identified the metabolite clusters whose dynamic behaviors depend on NaCl and trehalose. The volcano plot revealed several reporter metabolites whose dynamics greatly change between in the NaCl and trehalose cultures. The elastic net identified some critical, intracellular metabolites that are distinct between the NaCl and trehalose. While a relatively small number of intracellular metabolites related to the cell growth, glucose, glutamine, lactate and ammonium ion concentrations, the mechanism of antibody production was suggested to be very complicated or not to be explained by elastic net regression analysis. PMID:26803706

  10. Donor-Specific Anti-HLA Antibodies in Allogeneic Hematopoietic Stem Cell Transplantation

    Science.gov (United States)

    Morin-Zorman, Sarah; Loiseau, Pascale; Taupin, Jean-Luc; Caillat-Zucman, Sophie

    2016-01-01

    Allogeneic hematopoietic stem cell transplantation (AHSCT) is a curative treatment for a wide variety of hematological diseases. In 30% of the cases, a geno-identical donor is available. Any other situation displays some level of human leukocyte antigen (HLA) incompatibility between donor and recipient. Deleterious effects of anti-HLA immunization have long been recognized in solid organ transplant recipients. More recently, anti-HLA immunization was shown to increase the risk of primary graft failure (PGF), a severe complication of AHSCT that occurs in 3–4% of matched unrelated donor transplantation and up to 15% in cord blood transplantation and T-cell depleted haplo-identical stem cell transplantation. Rates of PGF in patients with DSA were reported to be between 24 and 83% with the highest rates in haplo-identical and cord blood transplantation recipients. This led to the recommendation of anti-HLA antibody screening to detect donor-specific antibodies (DSA) in recipients prior to AHSCT. In this review, we highlight the role of anti-HLA antibodies in AHSCT and the mechanisms that may lead to PGF in patients with DSA, and discuss current issues in the field.

  11. 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. PMID:23243240

  12. Triiodothyronine improves the primary antibody response to sheep red blood cells in severely undernourished weanling mice

    International Nuclear Information System (INIS)

    Three experiments were conducted in which weanling mice were fed a nutritionally complete diet either ad libitum or in restricted quantities such that they lost about 30% of their initial weight over a 14-day period. In Experiments 1 and 2, half the animals from each group received dietary triiodothyronine (T3) supplements. In Experiment 3, food-intake-restricted mice were fed graded levels of potassium iodide. Malnutrition reduced the number of nucleated cells per spleen, the number of splenic IgG plaque-forming cells (PFC) per 106 cells, and the serum antibody titers against sheep red blood cells as determined by radioimmunoassay. T3 supplements increased antibody titers, the number of nucleated cells per spleen, and both IgM and IgG PFC per 106 spleen cells in malnourished mice, but had no effect on well-nourished mice. The beneficial effect of T3 was not a result of improved protein, energy, or iodine status in the malnourished mice

  13. SPECIFIC UPTAKE OF MONOCLONAL ANTIBODY-CONJUGATED METHOTREXATE BY HUMAN LYMPHOCYTIC LEUKEMIC B CELLS

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhenping; Yang Chunzheng; Tarunendu Ghose; Jaroslav Kralovec

    1998-01-01

    Objective: To analysis the uptake of free MTX and MTX conjugated to tumor specific monoclonal antibody by target and non-target cells. Methods: The folate antagonist methotrexate (MTX) was conjugated to two monoclonal antibodies (Mab) directed against human chronic lymphocytic leukemia (CLL), Dal B01 and Dal B02, by an active ester method. Both conjugates were more cytotoxic toward the target tumor cell line D10-1than to the non-target cell line MOLT-3, and Dal B02-MTX conjugate was more inhibitory to D10-1 cells than free MTX in a 6 h pulse exposure assay. Results: Drug uptake studies revealed that D10-1 cells took up much more Dal B01 and Dal B02-conjugated MTX than free MTX. The amounts of drug taken up by D10-1 cells incubated with Dal B01 and Dal B02-conjugated MTX were always 3 to 5-fold higher than that taken up by MOLT-3 cells, although the latter took up more drug when incubated with free MTX. Furthermore, tumor cells incubated with Dal B01 or Dal B02-conjugated MTX retained much larger amounts of drug for a prolonged period of time than those incubated with free MTX.Conclusion: The enhanced specific cytotoxicity of Dal B01 and Dal B02-MTX conjugates toward target tumor cells is therefore likely due to (Ⅰ) delivery of larger amounts of MTX to target cells when the drug is conjugated to Mab;(ii) longer retention of Mab-conjugated MTX by target cells; and (iii) slow, prolonged release of MTX from the surface-bound or endocytosed conjugates, rendering them into a sustained release dosage form.

  14. A high-yielding, generic fed-batch process for recombinant antibody production of GS-engineered cell lines

    DEFF Research Database (Denmark)

    Fan, Li; Zhao, Liang; Sun, Yating;

    2009-01-01

    An animal component-free and chemically defined fed-batch process for GS-engineered cell lines producing recombinant antibodies has been developed. The fed-batch process relied on supplying sufficient nutrients to match their consumption, simultaneously minimizing the accumulation of byproducts....... Compared to batch cultures, the fed-batch technology generated the magnitude of the increase in cell yields (5 fold) and final antibody concentrations (4-8 fold). The majority of the increase in final antibody concentration was functions of the increased cell density and the prolonged culture time. This...... generic and high-yielding fed-batch process would shorten development time, and ensure process stability, thereby facilitating the manufacture of therapeutic antibodies by GS-engineered cell lines....

  15. 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...

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

    Science.gov (United States)

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

    2015-08-01

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

  17. Tumor targeting of humanized fragment antibody secreted from transgenic rice cell suspension culture

    DEFF Research Database (Denmark)

    Hong, Shin-Young; Lee, Tae-Sup; Kim, Ju; Jung, Jae-Ho; Choi, Chang-Woon; Kim, Tae-Geum; Kwon, Tae-Ho; Jang, Yong-Suk; Yang, Moon-Sik

    The tumor-associated glycoprotein 72 (TAG 72) has been shown to be expressed in the majority of human adenocarcinomas. In an effort to develop a technique for the safe and inexpensive production of large quantities of anti-TAG 72 humanized antibody fragments (hzAb) as a future source of clinical......-grade proteins, we developed a transgenic rice cell suspension culture system. The in vivo assembly and secretion of hzAb were achieved in a transgenic rice cell culture under the control of the rice alpha amylase 3D (RAmy 3D) expression system, and the biological activities of plant-derived hzAb were determined...

  18. Persistence of Yellow Fever vaccine-induced antibodies after cord blood stem cell transplant.

    Science.gov (United States)

    Avelino-Silva, Vivian Iida; Freire, Marcos da Silva; Rocha, Vanderson; Rodrigues, Celso Arrais; Novis, Yana Sarkis; Sabino, Ester C; Kallas, Esper Georges

    2016-04-01

    We report the case of a cord blood haematopoietic stem cell transplant recipient who was vaccinated for Yellow Fever (YF) 7 days before initiating chemotherapy and had persistent YF antibodies more than 3 years after vaccination. Since the stem cell donor was never exposed to wild YF or to the YF vaccine, and our patient was not exposed to YF or revaccinated, this finding strongly suggests the persistence of recipient immunity. We briefly discuss potential consequences of incomplete elimination of recipient's leukocytes following existing haematopoietic cancer treatments. PMID:26618995

  19. Photocleavable DNA barcode-antibody conjugates allow sensitive and multiplexed protein analysis in single cell

    Science.gov (United States)

    Agasti, Sarit S.; Liong, Monty; Peterson, Vanessa M.; Lee, Hakho; Weissleder, Ralph

    2012-01-01

    DNA barcoding is an attractive technology as it allows sensitive and multiplexed target analysis. However, DNA barcoding of cellular proteins remains challenging, primarily because barcode amplification and readout techniques are often incompatible with the cellular microenvironment. Here, we describe the development and validation of a photocleavable DNA barcode-antibody conjugate method for rapid, quantitative and multiplexed detection of proteins in single live cells. Following target binding, this method allows DNA barcodes to be photoreleased in solution, enabling easy isolation, amplification and readout. As a proof of principle, we demonstrate sensitive and multiplexed detection of protein biomarkers in a variety of cancer cells. PMID:23092113

  20. Cleavage efficient 2A peptides for high level monoclonal antibody expression in CHO cells

    OpenAIRE

    Chng, Jake; Wang, Tianhua; Nian, Rui; Lau, Ally; Hoi, Kong Meng; Ho, Steven CL; Gagnon, Peter; Bi, Xuezhi; Yang, Yuansheng

    2015-01-01

    Linking the heavy chain (HC) and light chain (LC) genes required for monoclonal antibodies (mAb) production on a single cassette using 2A peptides allows control of LC and HC ratio and reduces non-expressing cells. Four 2A peptides derived from the foot-and-mouth disease virus (F2A), equine rhinitis A virus (E2A), porcine teschovirus-1 (P2A) and Thosea asigna virus (T2A), respectively, were compared for expression of 3 biosimilar IgG1 mAbs in Chinese hamster ovary (CHO) cell lines. HC and LC ...

  1. Production and Characterization of Monoclonal Antibodies against Vegetative Cells of Bacillus cereus

    OpenAIRE

    Charni, Nadine; Perissol, Claude; Le Petit, Jean; Rugani, Nathalie

    2000-01-01

    Two monoclonal antibodies (MAbs) against Bacillus cereus were produced. The MAbs (8D3 and 9B7) were selected by enzyme-linked immunosorbent assay for their reactivity with B. cereus vegetative cells. They reacted with B. cereus vegetative cells while failing to recognize B. cereus spores. Immunoblotting revealed that MAb 8D3 recognized a 22-kDa antigen, while MAb 9B7 recognized two antigens with molecular masses of approximately 58 and 62 kDa. The use of MAbs 8D3 and 9B7 in combination to dev...

  2. Antibody-Dependent NK Cell Activation Is Associated with Late Kidney Allograft Dysfunction and the Complement-Independent Alloreactive Potential of Donor-Specific Antibodies.

    Science.gov (United States)

    Legris, Tristan; Picard, Christophe; Todorova, Dilyana; Lyonnet, Luc; Laporte, Cathy; Dumoulin, Chloé; Nicolino-Brunet, Corinne; Daniel, Laurent; Loundou, Anderson; Morange, Sophie; Bataille, Stanislas; Vacher-Coponat, Henri; Moal, Valérie; Berland, Yvon; Dignat-George, Francoise; Burtey, Stéphane; Paul, Pascale

    2016-01-01

    Although kidney transplantation remains the best treatment for end-stage renal failure, it is limited by chronic humoral aggression of the graft vasculature by donor-specific antibodies (DSAs). The complement-independent mechanisms that lead to the antibody-mediated rejection (ABMR) of kidney allografts remain poorly understood. Increasing lines of evidence have revealed the relevance of natural killer (NK) cells as innate immune effectors of antibody-dependent cellular cytotoxicity (ADCC), but few studies have investigated their alloreactive potential in the context of solid organ transplantation. Our study aimed to investigate the potential contribution of the antibody-dependent alloreactive function of NK cells to kidney graft dysfunction. We first conducted an observational study to investigate whether the cytotoxic function of NK cells is associated with chronic allograft dysfunction. The NK-Cellular Humoral Activation Test (NK-CHAT) was designed to evaluate the recipient and antibody-dependent reactivity of NK cells against allogeneic target cells. The release of CD107a/Lamp1(+) cytotoxic granules, resulting from the recognition of rituximab-coated B cells by NK cells, was analyzed in 148 kidney transplant recipients (KTRs, mean graft duration: 6.2 years). Enhanced ADCC responsiveness was associated with reduced graft function and identified as an independent risk factor predicting a decline in the estimated glomerular filtration rate over a 1-year period (hazard ratio: 2.83). In a second approach, we used the NK-CHAT to reveal the cytotoxic potential of circulating alloantibodies in vitro. The level of CD16 engagement resulting from the in vitro recognition of serum-coated allogeneic B cells or splenic cells was further identified as a specific marker of DSA-induced ADCC. The NK-CHAT scoring of sera obtained from 40 patients at the time of transplant biopsy was associated with ABMR diagnosis. Our findings indicate that despite the administration of

  3. Fc receptor-mediated, antibody-dependent enhancement of bacteriophage lambda-mediated gene transfer in mammalian cells

    OpenAIRE

    Sapinoro, Ramil; Volcy, Ketna; Shanaka, W.W.; Rodrigo, I.; Schlesinger, Jacob J.; Dewhurst, Stephen

    2008-01-01

    Lambda phage vectors mediate gene transfer in cultured mammalian cells and in live mice, and in vivo phage-mediated gene expression is increased when mice are pre-immunized with bacteriophage lambda. We now show that, like eukaryotic viruses, bacteriophage vectors are subject to Fc receptor-mediated, antibody-dependent enhancement of infection in mammalian cells. Antibody-dependent enhancement of phage gene transfer required FcγRI, but not its associated γ chain, and was not supported by othe...

  4. Localization of betav tubulin in the cochlea and cultured cells with a novel monoclonal antibody.

    Science.gov (United States)

    Banerjee, Asok; Jensen-Smith, Heather; Lazzell, Anna; Prasad, Veena; Elguezabal, Gerardo; Hallworth, Richard; Ludueña, Richard F

    2008-06-01

    Tubulin, the dimeric structural protein of microtubules, is a heterodimer of alpha and beta subunits; both alpha and beta exist as numerous isotypes encoded by different genes. In vertebrates the sequence differences among the beta(I), beta(II), beta(III), beta(IV) and beta(V) isotypes are highly conserved in evolution, implying that the isotypes may have functional significance. Isotype-specific monoclonal antibodies have been useful in determining the cellular and sub-cellular distributions and possible functions of the beta(I), beta(II), beta(III), and beta(IV) isotypes; however, little is known about the beta(V) isotype. We here report the creation and purification of a monoclonal antibody (SHM.12G11) specific for beta(V). The antibody was designed to be specific for the C-terminal sequence EEEINE, which is unique to rodent and chicken beta(V). The antibody was found to bind specifically to the C-terminal peptide EEEINE, and does not cross-react with the carboxy-termini of either alpha-tubulin or the other beta-tubulin isotypes. However, the antibody also binds to the peptide EEEVNE, but not to the peptide EEEIDG, corresponding respectively to the C-terminal peptides of bovine and human beta(V). Immunofluorescence analysis indicates that beta(V) is found in microtubules of both the interphase network and the mitotic spindle. In gerbils, beta(V) also occurs in the cochlea where it is found largely in the specialized cells that are unique in containing bundled microtubules with 15 protofilaments. PMID:18412253

  5. Anti-ganglioside antibody-induced tumor cell death by loss of membrane integrity.

    Science.gov (United States)

    Roque-Navarro, Lourdes; Chakrabandhu, Krittalak; de León, Joel; Rodríguez, Sandra; Toledo, Carlos; Carr, Adriana; de Acosta, Cristina Mateo; Hueber, Anne-Odile; Pérez, Rolando

    2008-07-01

    Gangliosides have been involved in multiple cellular processes such as growth, differentiation and adhesion, and more recently as regulators of cell death signaling pathways. Some of these molecules can be considered as tumor-associated antigens, in particular, N-glycolyl sialic acid-containing gangliosides, which are promising candidates for cancer-targeted therapy because of their low expression in normal human tissues. In this study, we provided the molecular and cellular characterization of a novel cell death mechanism induced by the anti-NGcGM3 14F7 monoclonal antibody (mAb) in L1210 murine tumor cell line but not in mouse normal cells (B and CD4(+) T lymphocytes) that expressed the antigen. Impairment of ganglioside synthesis in tumor cells abrogated the 14F7 mAb cytotoxic effect; however, exogenous reincorporation of the ganglioside did not restore tumor cell sensitivity to 14F7 mAb-induced cytotoxicity. 14F7 F(ab')(2) but not Fab fragments retained the cytotoxic capacity of the whole mAb. By contrary, other mAb, which recognizes N-glycolylated gangliosides, did not show any cytotoxic effect. These mAbs showed quite different capacities to bind NGcGM3-positive cell lines measured by binding inhibition experiments. Interestingly, this complement-independent cell death mechanism did not resemble apoptosis, because no DNA fragmentation, caspase activation, or Fas mediation were observed. However, NGcGM3 ganglioside-mediated 14F7 mAb-induced cell death was accompanied by cellular swelling, membrane lesion formation, and cytoskeleton activation, suggesting an oncosis-like phenomenon. This novel mechanism of cell death lets us to support further therapeutic approaches using NGcGM3 as a molecular target for antibody-based cancer immunotherapy. PMID:18645013

  6. Enhancement of antibody-dependent cell mediated cytotoxicity: a new era in cancer treatment

    Directory of Open Access Journals (Sweden)

    Rajasekaran N

    2015-05-01

    Full Text Available Narendiran Rajasekaran,1,* Cariad Chester,1,* Atsushi Yonezawa,1,2 Xing Zhao,1,3 Holbrook E Kohrt1 1Division of Oncology, Stanford School of Medicine, Stanford University, Stanford, CA, USA; 2Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital, Kyoto, Japan; 3Tissue Engineering and Stem Cells Research Center, Department of Immunology, Guiyang Medical University, Guiyang, Guizhou Province, People's Republic of China *These authors contributed equally to this work Abstract: The therapeutic efficacy of some anti-tumor monoclonal antibodies (mAbs depends on the capacity of the mAb to recognize the tumor-associated antigen and induce cytotoxicity via a network of immune effector cells. This process of antibody-dependent cell-mediated cytotoxicity (ADCC against tumor cells is triggered by the interaction of the fragment crystallizable (Fc portion of the mAb with the Fc receptors on effector cells like natural killer cells, macrophages, γδ T cells, and dendritic cells. By augmenting ADCC, the antitumor activity of mAbs can be significantly increased. Currently, identifying and developing therapeutic agents that enhance ADCC is a growing area of research. Combining existing tumor-targeting mAbs and ADCC-promoting agents that stimulate effector cells will translate to greater clinical responses. In this review, we discuss strategies for enhancing ADCC and emphasize the potential of combination treatments that include US Food and Drug Administration-approved mAbs and immunostimulatory therapeutics. Keywords: ADCC, NK cell, reovirus, TLR, CD137

  7. Human monoclonal antibody directed against an envelope glycoprotein of human T-cell leukemia virus type I.

    OpenAIRE

    Matsushita, S; Robert-Guroff, M; Trepel, J. (Jane); Cossman, J; Mitsuya, H; Broder, S

    1986-01-01

    We report the production and characterization of a human monoclonal antibody reactive against the major envelope glycoprotein of human T-cell leukemia virus type I (HTLV-I), a virus linked to the etiology of adult T-cell leukemia. We exposed lymph-node cells derived from a patient with adult T-cell leukemia to the Epstein-Barr virus in vitro and obtained a B-cell clone (designated 0.5 alpha) by a limiting dilution technique. The secreted product of 0.5 alpha is a monoclonal antibody (also des...

  8. Regulation of IL-2 induced proliferation and cytotoxicity in human natural killer cells by monoclonal antibodies

    International Nuclear Information System (INIS)

    Natural killer (NK) activity is mediated by a subpopulation of cells termed large granular lymphocytes (LGL), which exhibit cytotoxic activity against a variety of tumor targets. LGL express OKT8, OKT9, OKT10, OKT11, 3G8 (FcγR), OKM1, NKH1. The addition of recombinant IL-2 (rIL-2), increases cytotoxicity, induces IFN-γ production and leads to LGL proliferation. Since monoclonal antibodies (MoAb) represent highly specific probes to analyze possible surface molecules, they have studied the role of various MoAbs in the regulation of cytotoxicity, proliferation, and secretory function of purified LGL. LGL were isolated from nonadherent human peripheral blood leukocytes on discontinuous Percoll density gradients, followed by 290C E-rosette depletion of contaminating T cells. These preparations were ≥ 85% LGL and contained ≥ 5% OKT3+ cells. Using a limiting dilution assay, purified LGL were incubated with rIL-2 and the MoAbs (10 μg/ml) for 7 days. These cells were tested for cytotoxicity against K562 in a 51Cr- release assay, and for proliferation as determined by 3H-thymidine incorporation. Results indicate that the OKT9 antibody inhibited both the cytotoxicity and proliferation. MoAb against LGl markers (OKT11, OKT8, OKM1, 3G8, and NKH1) had no effect on cytotoxicity or proliferation. Unlike the T cell receptor complex (with OKT3), the surface molecules examined do not regulate LGL lysis or proliferation

  9. scFv-based “grababody” as a general strategy to improve recruitment of immune effector cells to antibody-targeted tumors

    OpenAIRE

    Cai, Zheng; Fu, Ting; Nagai, Yasuhiro; Lam, Lian; Yee, Marla; Zhu, Zhiqiang; Zhang, Hongtao

    2013-01-01

    Recruitment of immune cells to tumor cells targeted by a therapeutic antibody can heighten the antitumor efficacy of the antibody. For example, p185her2/neu-targeting antibodies not only downregulate the p185her2/neu kinase (ERBB2) but also trigger complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) through the antibody Fc region. Here we describe a generalized strategy to improve immune cell recruitment to targeted cancer cells, using a modified scFv a...

  10. Malignant monoblasts can function as effector cells in natural killer cell and antibody-dependent cellular cytotoxicity assays

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Ellegaard, J

    1981-01-01

    This is the first report describing natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) of malignant monoblasts. Pure acute monoblastic leukemia was diagnosed in bone marrow aspirations from two patients by use of conventional cytochemical methods as well as multiple immunologic...... modulation was seen in ADCC. These findings are discussed in the light of our present knowledge of lymphoid NK cells. Udgivelsesdato: 1981-May...

  11. Synthetic B-Cell Epitopes Eliciting Cross-Neutralizing Antibodies: Strategies for Future Dengue Vaccine.

    Science.gov (United States)

    Ramanathan, Babu; Poh, Chit Laa; Kirk, Kristin; McBride, William John Hannan; Aaskov, John; Grollo, Lara

    2016-01-01

    Dengue virus (DENV) is a major public health threat worldwide. A key element in protection from dengue fever is the neutralising antibody response. Anti-dengue IgG purified from DENV-2 infected human sera showed reactivity against several peptides when evaluated by ELISA and epitope extraction techniques. A multi-step computational approach predicted six antigenic regions within the E protein of DENV-2 that concur with the 6 epitopes identified by the combined ELISA and epitope extraction approach. The selected peptides representing B-cell epitopes were attached to a known dengue T-helper epitope and evaluated for their vaccine potency. Immunization of mice revealed two novel synthetic vaccine constructs that elicited good humoral immune responses and produced cross-reactive neutralising antibodies against DENV-1, 2 and 3. The findings indicate new directions for epitope mapping and contribute towards the future development of multi-epitope based synthetic peptide vaccine. PMID:27223692

  12. Synthetic B-Cell Epitopes Eliciting Cross-Neutralizing Antibodies: Strategies for Future Dengue Vaccine.

    Directory of Open Access Journals (Sweden)

    Babu Ramanathan

    Full Text Available Dengue virus (DENV is a major public health threat worldwide. A key element in protection from dengue fever is the neutralising antibody response. Anti-dengue IgG purified from DENV-2 infected human sera showed reactivity against several peptides when evaluated by ELISA and epitope extraction techniques. A multi-step computational approach predicted six antigenic regions within the E protein of DENV-2 that concur with the 6 epitopes identified by the combined ELISA and epitope extraction approach. The selected peptides representing B-cell epitopes were attached to a known dengue T-helper epitope and evaluated for their vaccine potency. Immunization of mice revealed two novel synthetic vaccine constructs that elicited good humoral immune responses and produced cross-reactive neutralising antibodies against DENV-1, 2 and 3. The findings indicate new directions for epitope mapping and contribute towards the future development of multi-epitope based synthetic peptide vaccine.

  13. Cell Wall Growth and Modulation Dynamics in a Model Unicellular Green Alga—Penium margaritaceum: Live Cell Labeling with Monoclonal Antibodies

    OpenAIRE

    Domozych, David S; Hannah Brechka; Alicia Britton; Marc Toso

    2011-01-01

    Penium margaritaceum is a unicellular charophycean green alga that possesses cell wall polymers similar to those of land plants. Several wall macromolecules of this alga are recognized by monoclonal antibodies specific for wall polymer epitopes of land plants. Immunofluorescence protocols using these antibodies may be employed to label specific cell wall constituents of live cells. Fluorescent labeling persists for several days, and this attribute allows for tracing of wall epitopes in both l...

  14. A radioimmunoassay that sandwiches human interleukin-2 between radiolabeled monoclonal antibody and the receptor on a hematopoietic cell line

    International Nuclear Information System (INIS)

    Two monoclonal antibodies were raised against human interleukin-2 (IL-2) produced by E. coli harboring recombinant complemental DNA. Both antibodies did not neutralize its activity, nor did they inhibit the binding of IL-2 to the receptor on target cells. Taking advantage of the ability of monoclonal antibodies to detect IL-2 that had bound to the receptor, a radioimmunoassay was developed that sandwiched IL-2 between the radiolabeled monoclonal antibody and the receptor on a hematopoietic cell line infected with human T cell leukemia virus Type I. The assay has the advantage of detecting only IL-2 with the ability to bind to the receptor, and display a linear dose-response relationship over concentrations ranging from 5 to 100 ng/ml. (Auth.)

  15. Expression of HSV-1 ICP0 Antigen Peptide in Prokaryotic Cells and Preparation of Specific Antibody

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an immediate-early protein of herpes simplex virus, infected-cell polypeptide 0 (ICP0) exhibits complicated interactions with host cells, and its regulatory function on gene expression is of great importance. Since the ICP0 encoding sequence contains many rare codons which are absent in E.coli, and ICP0 is highly unstable in prokaryotic cells, expression of entire ICP0 in prokaryotic cells has never been reported. In order to further investigate the function of ICP0, a recombinant plasmid was constructed by subcloning a cDNA fragment encoding an amino-terminal of 105 residues of the ICP0 protein into pGEX-5x-1 vector. The resulting GST-105 fusion antigen peptide was expressed with high efficiency in E.coli. Antibodies prepared after the immunization of mice with purified fusion protein can recognize not only the denatured ICP0 protein, but also the native ICP0 protein with normal biological conformation.

  16. FDC-B1: a new monoclonal antibody directed against bovine follicular dendritic cells.

    Science.gov (United States)

    Mélot, F; Defaweux, V; Jolois, O; Collard, A; Robert, B; Heinen, E; Antoine, N

    2004-01-01

    Follicular dendritic cells (FDCs) are a unique population of accessory cells located in the light zone of the germinal centres of lymphoid follicles. Their involvement in the generation of humoral immune responses implies a potential role for these cells in many disorders. Indeed, in prion diseases, FDCs seem to be the major sites of extraneuronal cellular prion protein expression and the principal sites of the infectious agent accumulation in lymphoid organs. The identification of FDC is useful for the analysis of their distribution in reactive lymphoid tissue as well as in pathological conditions. The production and characterisation of a new mouse monoclonal antibody directed against bovine follicular dendritic cells (FDC-B1) is reported. The antigen detected by FDC-B1 is expressed exclusively on the surface of FDCs in ruminant lymphoid organs. The antigen has an approximate molecular weight of 28 kDa. PMID:14700533

  17. Tumor-specific cytotoxic t cells are crucial for efficacy of immunomodulatory antibodies in patients with lung cancer

    NARCIS (Netherlands)

    J.G.J.V. Aerts (Joachim); J.P.J.J. Hegmans (Joost)

    2013-01-01

    textabstractThere is growing evidence that activation of the immune system may be an effective treatment for patients with either small cell lung cancer or non-small cell lung cancer (NSCLC). Immunomodulatory antibodies directed against cytotoxic T cell-associated antigen 4 (CTLA-4/CD152) and progra

  18. A role for plasma cell targeting agents in immune tolerance induction in autoimmune disease and antibody responses to therapeutic proteins.

    Science.gov (United States)

    Rosenberg, A S; Pariser, A R; Diamond, B; Yao, L; Turka, L A; Lacana, E; Kishnani, P S

    2016-04-01

    Antibody responses to life saving therapeutic protein products, such as enzyme replacement therapies (ERT) in the setting of lysosomal storage diseases, have nullified product efficacy and caused clinical deterioration and death despite treatment with immune-suppressive therapies. Moreover, in some autoimmune diseases, pathology is mediated by a robust antibody response to endogenous proteins such as is the case in pulmonary alveolar proteinosis, mediated by antibodies to Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF). In this work, we make the case that in such settings, when the antibody response is high titered, sustained, and refractory to immune suppressive treatments, the antibody response is mediated by long-lived plasma cells which are relatively unperturbed by immune suppressants including rituximab. However, long-lived plasma cells can be targeted by proteasome inhibitors such as bortezomib. Recent reports of successful reversal of antibody responses with bortezomib in the settings of ERT and Thrombotic Thrombocytopenic Purpura (TTP) argue that the safety and efficacy of such plasma cell targeting agents should be evaluated in larger scale clinical trials to delineate the risks and benefits of such therapies in the settings of antibody-mediated adverse effects to therapeutic proteins and autoantibody mediated pathology. PMID:26928739

  19. Early postnatal B cell ontogeny and antibody repertoire maturation in the opossum, Monodelphis domestica.

    Directory of Open Access Journals (Sweden)

    Xinxin Wang

    Full Text Available Marsupials are a lineage of mammals noted for giving birth to highly altricial young, which complete much of their "fetal" development externally attached to a teat. Postnatal B cell ontogeny and diversity was investigated in a model marsupial species, the gray short-tailed opossum, Monodelphis domestica. The results support the initiation of B cell development late in gestation and progressing into the first two weeks of postnatal life. Transcription of CD79a and CD79b was detected in embryonic tissue prior to birth, while immunoglobulin heavy chain locus transcription was not detected until the first postnatal 24 hours. Transcription of the Ig light chains was not detected until postnatal day 7 at the earliest. The predicted timing of the earliest appearance of mature B cells and completion of gene rearrangements is consistent with previous analyses on the timing of endogenous antibody responses in newborn marsupials. The diversity of early B cell IgH chains is limited, as has been seen in fetal humans and mice, but lacks bias in the gene segments used to encode the variable domains. Newborn light chain diversity is, from the start, comparable to that of the adult, consistent with an earlier hypothesis that light chains contribute extensively to antibody diversity in this species.

  20. Targeting natural killer cell reactivity by employing antibody to NKp46: implications for type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Rami Yossef

    Full Text Available Natural killer (NK cells belong to the innate lymphoid cells. Their cytotoxic activity is regulated by the delicate balance between activating and inhibitory signals. NKp46 is a member of the primary activating receptors of NK cells. We previously reported that the NKp46 receptor is involved in the development of type 1 diabetes (T1D. Subsequently, we hypothesized that blocking this receptor could prevent or hinder disease development. To address this goal, we developed monoclonal antibodies for murine NKp46. One mAb, named NCR1.15, recognizes the mouse homologue protein of NKp46, named Ncr1, and was able to down-regulate the surface expression of NKp46 on primary murine NK cells following antibody injection in vivo. Additionally, NCR1.15 treatments were able to down-regulate cytotoxic activity mediated by NKp46, but not by other NK receptors. To test our primary assumption, we examined T1D development in two models, non-obese diabetic mice and low-dose streptozotocin. Our results show a significantly lower incidence of diabetic mice in the NCR1.15-treated group compared to control groups. This study directly demonstrates the involvement of NKp46 in T1D development and suggests a novel treatment strategy for early insulitis.

  1. Differences in the composition of the human antibody repertoire by B cell subsets in the blood

    Directory of Open Access Journals (Sweden)

    Eva Szymanska eMroczek

    2014-03-01

    Full Text Available The vast initial diversity of the antibody repertoire is generated centrally by means of a complex series of V (D J gene rearrangement events, variation in the site of gene segment joining, and TdT catalyzed N- region addition. Although the diversity is great, close inspection has revealed distinct and unique characteristics in the antibody repertoires expressed by different B cell developmental subsets. In order to illustrate our approach to repertoire analysis, we present an in-depth comparison of V (D J gene usage, hydrophobicity, length, DH reading frame, and amino acid usage between heavy chain repertoires expressed by immature, transitional, mature, memory IgD+, memory IgD-, and plasmacytes isolated from the blood of a single individual. Our results support the view that in both human and mouse the H chain repertoires expressed by individual, developmental B cell subsets appear to differ in sequence content. Sequencing of unsorted B cells from the blood is thus likely to yield an incomplete or compressed view of what is actually happening in the immune response of the individual. Our findings support the view that studies designed to correlate repertoire expression with diseases of immune function will likely require deep sequencing of B cells sorted by subset.

  2. Gluten-specific antibodies of celiac disease gut plasma cells recognize long proteolytic fragments that typically harbor T-cell epitopes.

    Science.gov (United States)

    Dørum, Siri; Steinsbø, Øyvind; Bergseng, Elin; Arntzen, Magnus Ø; de Souza, Gustavo A; Sollid, Ludvig M

    2016-01-01

    This study aimed to identify proteolytic fragments of gluten proteins recognized by recombinant IgG1 monoclonal antibodies generated from single IgA plasma cells of celiac disease lesions. Peptides bound by monoclonal antibodies in complex gut-enzyme digests of gluten treated with the deamidating enzyme transglutaminase 2, were identified by mass spectrometry after antibody pull-down with protein G beads. The antibody bound peptides were long deamidated peptide fragments that contained the substrate recognition sequence of transglutaminase 2. Characteristically, the fragments contained epitopes with the sequence QPEQPFP and variants thereof in multiple copies, and they typically also harbored many different gluten T-cell epitopes. In the pull-down setting where antibodies were immobilized on a solid phase, peptide fragments with multivalent display of epitopes were targeted. This scenario resembles the situation of the B-cell receptor on the surface of B cells. Conceivably, B cells of celiac disease patients select gluten epitopes that are repeated multiple times in long peptide fragments generated by gut digestive enzymes. As the fragments also contain many different T-cell epitopes, this will lead to generation of strong antibody responses by effective presentation of several distinct T-cell epitopes and establishment of T-cell help to B cells. PMID:27146306

  3. Gluten-specific antibodies of celiac disease gut plasma cells recognize long proteolytic fragments that typically harbor T-cell epitopes

    Science.gov (United States)

    Dørum, Siri; Steinsbø, Øyvind; Bergseng, Elin; Arntzen, Magnus Ø.; de Souza, Gustavo A.; Sollid, Ludvig M.

    2016-01-01

    This study aimed to identify proteolytic fragments of gluten proteins recognized by recombinant IgG1 monoclonal antibodies generated from single IgA plasma cells of celiac disease lesions. Peptides bound by monoclonal antibodies in complex gut-enzyme digests of gluten treated with the deamidating enzyme transglutaminase 2, were identified by mass spectrometry after antibody pull-down with protein G beads. The antibody bound peptides were long deamidated peptide fragments that contained the substrate recognition sequence of transglutaminase 2. Characteristically, the fragments contained epitopes with the sequence QPEQPFP and variants thereof in multiple copies, and they typically also harbored many different gluten T-cell epitopes. In the pull-down setting where antibodies were immobilized on a solid phase, peptide fragments with multivalent display of epitopes were targeted. This scenario resembles the situation of the B-cell receptor on the surface of B cells. Conceivably, B cells of celiac disease patients select gluten epitopes that are repeated multiple times in long peptide fragments generated by gut digestive enzymes. As the fragments also contain many different T-cell epitopes, this will lead to generation of strong antibody responses by effective presentation of several distinct T-cell epitopes and establishment of T-cell help to B cells. PMID:27146306

  4. γδ T Cell-Mediated Antibody-Dependent Cellular Cytotoxicity with CD19 Antibodies Assessed by an Impedance-Based Label-Free Real-Time Cytotoxicity Assay

    OpenAIRE

    Seidel, Ursula Jördis Eva; Vogt, Fabian; Grosse-Hovest, Ludger; Jung, Gundram; Handgretinger, Rupert; Lang, Peter

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T cells wi...

  5. Approaches to systems biology. Four methods to study single-cell gene expression, cell motility, antibody reactivity, and respiratory metabolism

    DEFF Research Database (Denmark)

    Hagedorn, Peter

    To understand how complex systems, such as cells, function, comprehensive Measurements of their constituent parts must be made. This can be achieved by combining methods that are each optimized to measure specific parts of the system. Four such methods,each covering a different area, are presented......: Transcript profiling of one cell type extracted from a complex tissue containing several cell types; observation and recording of cell motility; measurement of antibody reactivities using microarrays; and invivo measurement of free and bound NADH in mitochondria. Detailed statistical analysis of the data...... from such measurements allows models of the system to be developed and tested. For each of the methods, such analysis and modelling approaches have beenapplied and are presented: Differentially regulated genes are identified and classified according to function; cell-specfic motility models are...

  6. Natural Killer (NK- and T-Cell Engaging Antibody-Derived Therapeutics

    Directory of Open Access Journals (Sweden)

    Christoph Stein

    2012-06-01

    Full Text Available Unmodified antibodies (abs have been successful in the treatment of hematologic malignancies, but less so for the treatment of solid tumors. They trigger anti-tumor effects through their Fc-domains, and one way to improve their efficacy is to optimize their interaction with the effectors through Fc-engineering. Another way to empower abs is the design of bispecific abs and related fusion proteins allowing a narrower choice of effector cells. Here we review frequently chosen classes of effector cells, as well as common trigger molecules. Natural Killer (NK- and T-cells are the most investigated populations in therapeutical approaches with bispecific agents until now. Catumaxomab, the first bispecific ab to receive drug approval, targets the tumor antigen Epithelial Cell Adhesion Molecule (EpCAM and recruits T-cells via a binding site for the cell surface protein CD3. The next generation of recombinant ab-derivatives replaces the broadly reactive Fc-domain by a binding domain for a single selected trigger. Blinatumomab is the first clinically successful member of this class, targeting cancer cells via CD19 and engaging T-cells by CD3. Other investigators have developed related recombinant fusion proteins to recruit effectors, such as NK-cells and macrophages. The first such agents currently in preclinical and clinical development will be discussed.

  7. Anti-galactose antibodies do not bind to normal human red cells

    International Nuclear Information System (INIS)

    The authors investigated the possibility that senescent cell IgG might have an anti-galactose (anti-gal) specificity as suggested by others. Anti-gal was isolated from normal human serum with α melibiose-agarose. The assays used were hemagglutination, rosetting, phagocytosis, and 125I protein A binding assay, immunoblotting, and glycine/HCL, pH 2.3, versus sugar elutions. Results revealed binding of anti-gal to rabbit but not human RBC. Immunoblotting of anti-gal revealed labeling of approx.29 bands in rabbit red cell membranes and no labeling of autologous human red cell membranes. The authors attempted to inhibit binding of anti-gal with various sugars. Melibiose caused enhancement rather than inhibition of agglutination when used at concentrations reported by previous investigators to cause inhibition. Neither α melibiose or galactose caused inhibition of phagocytosis of senescent cells. Senescent cell IgG was not displaced from freshly isolated old red cells by incubation with melibiose or galactose as determined by an 125I protein A binding assay. The authors were also unable to elute IgG from stored red cells with galactose. The authors conclude that senescent cell IgG does not have an anti-galactose specificity. The authors were unable to demonstrate an anti-gal antibody to normal human red cells

  8. Simple Method To Prepare Oligonucleotide-Conjugated Antibodies and Its Application in Multiplex Protein Detection in Single Cells.

    Science.gov (United States)

    Gong, Haibiao; Holcomb, Ilona; Ooi, Aik; Wang, Xiaohui; Majonis, Daniel; Unger, Marc A; Ramakrishnan, Ramesh

    2016-01-20

    The diversity of nucleic acid sequences enables genomics studies in a highly multiplexed format. Since multiplex protein detection is still a challenge, it would be useful to use genomics tools for this purpose. This can be accomplished by conjugating specific oligonucleotides to antibodies. Upon binding of the oligonucleotide-conjugated antibodies to their targets, the protein levels can be converted to oligonucleotide levels. In this report we describe a simple method for preparing oligonucleotide-conjugated antibodies and discuss this method's application in oligonucleotide extension reaction (OER) for multiplex protein detection. Conjugation is based on strain-promoted alkyne-azide cycloaddition (the Cu-free click reaction), in which the antibody is activated with a dibenzocyclooctyne (DBCO) moiety and subsequently linked covalently with an azide-modified oligonucleotide. In the functional test, the reaction conditions and purification processes were optimized to achieve maximum yield and best performance. The OER assay employs a pair of antibody binders (two antibodies, each conjugated with its own oligonucleotide) developed for each protein target. The two oligonucleotides contain unique six-base complementary regions at their 3' prime ends to allow annealing and extension by DNA synthesis enzymes to form a DNA template. Following preamplification, the DNA template is detected by qPCR. Distinct oligonucleotide sequences are assigned to different antibody binders to enable multiplex protein detection. When tested using recombinant proteins, some antibody binders, such as those specific to CSTB, MET, EpCAM, and CASP3, had dynamic ranges of 5-6 logs. The antibody binders were also used in a multiplexed format in OER assays, and the binders successfully detected their protein targets in cell lysates, and in single cells in combination with the C1 system. This click reaction-based antibody conjugation procedure is cost-effective, needs minimal hands-on time, and

  9. Complement and Antibody-mediated Enhancement of Red Blood Cell Invasion and Growth of Malaria Parasites.

    Science.gov (United States)

    Biryukov, Sergei; Angov, Evelina; Landmesser, Mary E; Spring, Michele D; Ockenhouse, Christian F; Stoute, José A

    2016-07-01

    Plasmodium falciparum malaria is a deadly pathogen. The invasion of red blood cells (RBCs) by merozoites is a target for vaccine development. Although anti-merozoite antibodies can block invasion in vitro, there is no efficacy in vivo. To explain this discrepancy we hypothesized that complement activation could enhance RBC invasion by binding to the complement receptor 1 (CR1). Here we show that a monoclonal antibody directed against the merozoite and human polyclonal IgG from merozoite vaccine recipients enhanced RBC invasion in a complement-dependent manner and that soluble CR1 inhibited this enhancement. Sialic acid-independent strains, that presumably are able to bind to CR1 via a native ligand, showed less complement-dependent enhancement of RBC invasion than sialic acid-dependent strains that do not utilize native CR1 ligands. Confocal fluorescent microscopy revealed that complement-dependent invasion resulted in aggregation of CR1 at the RBC surface in contact with the merozoite. Finally, total anti-P. berghei IgG enhanced parasite growth and C3 deficiency decreased parasite growth in mice. These results demonstrate, contrary to current views, that complement activation in conjunction with antibodies can paradoxically aid parasites invade RBCs and should be considered in future design and testing of merozoite vaccines. PMID:27333049

  10. Amino acid consumption in naïve and recombinant CHO cell cultures: producers of a monoclonal antibody

    OpenAIRE

    Carrillo-Cocom, L. M.; Genel-Rey, T.; Araíz-Hernández, D.; López-Pacheco, F.; López-Meza, J.; Rocha-Pizaña, M. R.; Ramírez-Medrano, A.; Alvarez, M. M.

    2014-01-01

    Most commercial media for mammalian cell culture are designed to satisfy the amino acid requirements for cell growth, but not necessarily those for recombinant protein production. In this study, we analyze the amino acid consumption pattern in naïve and recombinant Chinese hamster ovary (CHO) cell cultures. The recombinant model we chose was a CHO-S cell line engineered to produce a monoclonal antibody. We report the cell concentration, product concentration, and amino acid concentration prof...

  11. A robust high throughput platform to generate functional recombinant monoclonal antibodies using rabbit B cells from peripheral blood.

    Directory of Open Access Journals (Sweden)

    Stefan Seeber

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

  12. Conditional expression of full-length humanized anti-prion protein antibodies in Chinese hamster ovary cells.

    Science.gov (United States)

    Mueller, Daniel A; Heinig, Lars; Ramljak, Sanja; Krueger, Astrid; Schulte, Reiner; Wrede, Arne; Stuke, Andreas W

    2010-12-01

    Because of their high antigen specificity and metabolic stability, genetically engineered human monoclonal antibodies are on the way to becoming one of the most promising medical diagnostics and therapeutics. In order to establish an in vitro system capable of producing such biosimilar antibodies, we used human constant chain sequences to design the novel human antibody expressing vector cassette pMAB-ABX. A bidirectional tetracycline (tet)-controllable promotor was used for harmonized expression of immunoglobulin type G (IgG) heavy and light chains. As an example we used anti-prion protein (anti-PrP) IgGs. Therefore, the variable heavy (V(H)) and light chain (V(L)) sequences of anti-PrP antibodies, previously generated in our laboratory by DNA immunization of prion protein knock-out mice, were isolated from murine hybridoma cell lines and inserted into pMAB-ABX vector. After transfection of Chinese hamster ovary (CHO) cells, a number of stable antibody producing cell clones were selected. One cell line (pMAB-ABX-13F10/3B5) stably expressing the recombinant humanized antibody (rechuAb) 13F10/3B5 was selected for detailed characterization by Western blot, immunofluorescence, and flow cytometric analyses. The full-length recombinant humanized IgG antibody showed a high level of expression in the cytoplasm. In conclusion, the new cell system described here is a suitable tool to produce functional intact full-length humanized IgG antibodies. PMID:21087094

  13. Mapping the stem cell state: eight novel human embryonic stem and embryonal carcinoma cell antibodies

    DEFF Research Database (Denmark)

    Wright, A; Andrews, N; Bardsley, K;

    2011-01-01

    ', yet it appears that this categorization may be an oversimplification, because a number of sub-states appear to exist within this state. To increase the resolution of the undifferentiated state, we have generated eight novel monoclonal antibodies, all capable of recognizing undifferentiated human ES...

  14. A solid-phase radioimmunoassay to detect antibodies produced by hybridomas to antigens derived from human melanoma cells

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay to detect antibodies that react with antigens derived from human melanoma cells is described. A soluble preparation derived from Nonidet P-40 lysates of tissue-cultured melanoma cells was dried on the surfaces of wells of polyvinyl chloride microtiter plates and fixed with 0.02% glutaraldehyde. Antibody preparations were added and incubated for 18 h at 40C. The wells were washed and bound antibodies were detected using radioactive Staphyloccoccal protein A (125I-SpA). Optimal conditions are described for all the steps employed. Concentrations of antigen selected, the amount of 125I-SpA employed and the duration of incubation of antibodies with antigen were found to be critical. The assay was sensitive and reproducible, and lent itself to the simultaneous evaluation of many individual antibody samples in a short period of time. The assay was particularly valuable for rapid screening of hybridoma supernatants for antibodies to antigens derived from melanoma cells and from a panel of other tumor and normal cells. (orig.)

  15. HLA Class II Antibody Activation of Endothelial Cells Promotes Th17 and Disrupts Regulatory T Lymphocyte Expansion.

    Science.gov (United States)

    Lion, J; Taflin, C; Cross, A R; Robledo-Sarmiento, M; Mariotto, E; Savenay, A; Carmagnat, M; Suberbielle, C; Charron, D; Haziot, A; Glotz, D; Mooney, N

    2016-05-01

    Kidney transplantation is the most successful treatment option for patients with end-stage renal disease, and chronic antibody-mediated rejection is the principal cause of allograft loss. Predictive factors for chronic rejection include high levels of HLA alloantibodies (particularly HLA class II) and activation of graft endothelial cells (ECs). The mechanistic basis for this association is unresolved. We used an experimental model of HLA-DR antibody stimulation of microvascular ECs to examine the mechanisms underlying the association between HLA class II antibodies, EC activation and allograft damage. Activation of ECs with the F(Ab')2 fragment of HLA-DR antibody led to phosphorylation of Akt, ERK and MEK and increased IL-6 production by ECs cocultured with allogeneic peripheral blood mononuclear cells (PBMCs) in an Akt-dependent manner. We previously showed that HLA-DR-expressing ECs induce polarization of Th17 and FoxP3(bright) regulatory T cell (Treg) subsets. Preactivation of ECs with anti-HLA-DR antibody redirected EC allogenicity toward a proinflammatory response by decreasing amplification of functional Treg and by further increasing IL-6-dependent Th17 expansion. Alloimmunized patient serum containing relevant HLA-DR alloantibodies selectively bound and increased EC secretion of IL-6 in cocultures with PBMCs. These data contribute to understanding of potential mechanisms of antibody-mediated endothelial damage independent of complement activation and FcR-expressing effector cells. PMID:26614587

  16. Women's attitude towards prenatal screening for red blood cell antibodies, other than RhD

    Directory of Open Access Journals (Sweden)

    van der Schoot CE

    2008-11-01

    Full Text Available Abstract Background Since July 1998 all Dutch women (± 200,000/y are screened for red cell antibodies, other than anti-RhesusD (RhD in the first trimester of pregnancy, to facilitate timely treatment of pregnancies at risk for hemolytic disease of the fetus and newborn (HDFN. Evidence for benefits, consequences and costs of screening for non-RhD antibodies is still under discussion. The screening program was evaluated in a nation-wide study. As a part of this evaluation study we investigated, according to the sixth criterium of Wilson and Jüngner, the acceptance by pregnant women of the screening program for non-RhD antibodies. Methods Controlled longitudinal survey, including a prenatal and a postnatal measurement by structured questionnaires. Main outcome measures: information satisfaction, anxiety during the screening process (a.o. STAI state inventory and specific questionnaire modules, overall attitude on the screening program. Univariate analysis was followed by standard multivariate analysis to identify significant predictors of the outcome measures. Participants: 233 pregnant women, distributed over five groups, according to the screening result. Results Satisfaction about the provided information was moderate in all groups. All screen- positive groups desired more supportive information. Anxiety increased in screen- positives during the screening process, but decreased to basic levels postnatally. All groups showed a strongly positive balance between perceived utility and burden of the screening program, independent on test results or background characteristics. Conclusion Women highly accept the non-RhD antibody screening program. However, satisfaction about provided information is moderate. Oral and written information should be provided by obstetric care workers themselves, especially to screen-positive women.

  17. Antibody-free magnetic cell sorting of genetically modified primary human CD4+ T cells by one-step streptavidin affinity purification.

    Directory of Open Access Journals (Sweden)

    Nicholas J Matheson

    Full Text Available Existing methods for phenotypic selection of genetically modified mammalian cells suffer disadvantages of time, cost and scalability and, where antibodies are used to bind exogenous cell surface markers for magnetic selection, typically yield cells coated with antibody-antigen complexes and beads. To overcome these limitations we have developed a method termed Antibody-Free Magnetic Cell Sorting in which the 38 amino acid Streptavidin Binding Peptide (SBP is displayed at the cell surface by the truncated Low Affinity Nerve Growth Receptor (LNGFRF and used as an affinity tag for one-step selection with streptavidin-conjugated magnetic beads. Cells are released through competition with the naturally occurring vitamin biotin, free of either beads or antibody-antigen complexes and ready for culture or use in downstream applications. Antibody-Free Magnetic Cell Sorting is a rapid, cost-effective, scalable method of magnetic selection applicable to either viral transduction or transient transfection of cell lines or primary cells. We have optimised the system for enrichment of primary human CD4+ T cells expressing shRNAs and exogenous genes of interest to purities of >99%, and used it to isolate cells following Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9 genome editing.

  18. Antibody-Free Magnetic Cell Sorting of Genetically Modified Primary Human CD4+ T Cells by One-Step Streptavidin Affinity Purification

    Science.gov (United States)

    Matheson, Nicholas J.; Peden, Andrew A.; Lehner, Paul J.

    2014-01-01

    Existing methods for phenotypic selection of genetically modified mammalian cells suffer disadvantages of time, cost and scalability and, where antibodies are used to bind exogenous cell surface markers for magnetic selection, typically yield cells coated with antibody-antigen complexes and beads. To overcome these limitations we have developed a method termed Antibody-Free Magnetic Cell Sorting in which the 38 amino acid Streptavidin Binding Peptide (SBP) is displayed at the cell surface by the truncated Low Affinity Nerve Growth Receptor (LNGFRF) and used as an affinity tag for one-step selection with streptavidin-conjugated magnetic beads. Cells are released through competition with the naturally occurring vitamin biotin, free of either beads or antibody-antigen complexes and ready for culture or use in downstream applications. Antibody-Free Magnetic Cell Sorting is a rapid, cost-effective, scalable method of magnetic selection applicable to either viral transduction or transient transfection of cell lines or primary cells. We have optimised the system for enrichment of primary human CD4+ T cells expressing shRNAs and exogenous genes of interest to purities of >99%, and used it to isolate cells following Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 genome editing. PMID:25360777

  19. Wildtype p53-specific Antibody and T-Cell Responses in Cancer Patients

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Stryhn, Anette; Justesen, Sune;

    2011-01-01

    Mutation in the p53 gene based on single amino acid substitutions is a frequent event in human cancer. Accumulated mutant p53 protein is released to antigen presenting cells of the immune system and anti-p53 immune responses even against wt p53 is induced and observed in a number of human cancer...... patients. Detection of antibodies against wt p53 protein has been used as a diagnostic and prognostic marker and discovery of new T-cell epitopes has enabled design of cancer vaccination protocols with promising results. Here, we identified wt p53-specific antibodies in various cancer patients and...... identified a broad range of responses against wt p53 protein and 15-mer peptides using a novel print array technology. Likewise, using bioinformatic tools in silico, we identified CD8 T-cell specificity or reactivity against HLA-A*02:01 binding peptides wt p53(65-73), wt p53(187-197), and wt p53(264-272) in...

  20. Detecting Proteins in Highly Autofluorescent Cells Using Quantum Dot Antibody Conjugates

    Directory of Open Access Journals (Sweden)

    Karen M. Orcutt

    2009-09-01

    Full Text Available We have applied quantum dot (Qdot antibody conjugates as a biomolecular probe for cellular proteins important in biogeochemical cycling in the sea. Conventional immunological methods have been hampered by the strong autofluorescence found in cyanobacteria cells. Qdot conjugates provide an ideal alternative for studies that require long-term imaging of cells such as detection of low abundance cellular antigens by fluorescence microscopy. The advantage of Qdot labeled probes over conventional immunological methods is the photostability of the probe. Phycoerythrin bleaches in cyanobacterial cells under prolonged UV or blue light excitation, which means that the semiconducting nanocrystal probe, the Qdot, can yield a strong fluorescent signal without interference from cellular pigments.

  1. Asymmetries in Chickens from Lines Selected and Relaxed for High or Low Antibody Titers to Sheep Red Blood Cells

    OpenAIRE

    Tu, Yunjie; Siegel, P B

    2015-01-01

    Wattle length, width, and area were measured to classify bilateral asymmetries in four lines of chickens. The lines were the S26 generation of White Leghorns selected for high (HAS) or low (LAS) response to sheep red blood cells and sublines in which selection had been relaxed for three generations (high antibody relaxed [HAR] and low antibody relaxed [LAR]). Antibody titers (AB) were greater for HAS than for HAR with both greater than for LAS and LAR which while different for males did not d...

  2. Changes in Leukocyte Subsets And Anti-dsDNA Antibody Levels After B Cell Depletion Therapy in Systemic Lupus Erythematosus

    OpenAIRE

    Lazarus, M. N.

    2015-01-01

    Clinical response to B cell depletion therapy (BCDT) is highly variable in patients with systemic lupus erythematosus (SLE). Reductions in anti-dsDNA antibody levels also vary. It has been shown that early relapse is more likely if anti-dsDNA antibody levels remain high after BCDT. The cellular factors that determine how anti-dsDNA antibodies are produced and whether they are likely to fall after BCDT have not been clarified. This thesis describes two different immunological processes that mi...

  3. Normal human serum contains a natural IgM antibody cytotoxic for human neuroblastoma cells.

    Science.gov (United States)

    Ollert, M W; David, K; Schmitt, C; Hauenschild, A; Bredehorst, R; Erttmann, R; Vogel, C W

    1996-04-30

    Neuroblastoma (NB) is characterized by the second highest spontaneous regression of any human malignant disorder, a phenomenon that remains to be elucidated. In this study, a survey of 94 normal human adult sera revealed a considerable natural humoral cytotoxicity against human NB cell lines in approximately one-third of the tested sera of both genders. Specific cell killing by these sera was in the range of 40% to 95%. Serum cytotoxicity was dependent on an intact classical pathway of complement. By several lines of evidence, IgM antibodies were identified as the cytotoxic factor in the sera. Further analyses revealed that a 260-kDa protein was recognized by natural IgM of cytotoxic sera in Western blots of NB cell extracts. The antigen was expressed on the surface of seven human NB cell lines but not on human melanoma or other control tumor cell lines derived from kidney, pancreas, colon, bone, skeletal muscle, lymphatic system, and bone marrow. Furthermore, no reactivity was observed with normal human fibroblasts, melanocytes, and epidermal keratinocytes. The antigen was expressed in vivo as detected by immunohistochemistry in both the tumor of a NB patient and NB tumors established in nude rats from human NB cell lines. Most interestingly, the IgM anti-NB antibody was absent from the sera of 11 human NB patients with active disease. The anti-NB IgM also could not be detected in tumor tissue obtained from a NB patient. Collectively, our data suggest the existence of a natural humoral immunological tumor defense mechanism, which could account for the in vivo phenomenon of spontaneous NB tumor regression. PMID:8633097

  4. The characterization and purification of DNA binding proteins present within herpes simplex virus infected cells using monoclonal antibodies

    International Nuclear Information System (INIS)

    Hybridomas secreting monoclonal antibodies against herpes simplex virus (HSV) DNA binding proteins (DBP) have been produced. Five HSV DBP have been characterized according to molecular weight, affinity for DNA, kinetic class and localization within the infected cell. By preparing an immunoadsorbent column from antibody TI8, its specific DBP was purified to apparent homogeneity. The purified DBP retained the ability to bind to DNA. (Author)

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

    OpenAIRE

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

    1998-01-01

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

  6. Target-selective homologous recombination cloning for high-throughput generation of monoclonal antibodies from single plasma cells

    OpenAIRE

    Isobe Masaharu; Yoshioka Megumi; Kurosawa Nobuyuki

    2011-01-01

    Abstract Background Molecular cloning of functional immunoglobulin genes from single plasma cells is one of the most promising technologies for the rapid development of monoclonal antibody drugs. However, the proper insertion of PCR-amplified immunoglobulin genes into expression vectors remains an obstacle to the high-throughput production of recombinant monoclonal antibodies. Results We developed a single-step cloning method, target-selective homologous recombination (TS-HR), in which PCR-am...

  7. Comparison of four enzyme immunoassays for detection of human T-cell lymphotropic virus type 2 antibodies.

    OpenAIRE

    Gallo, D; Yeh, E T; Moore, E S; Hanson, C V

    1996-01-01

    Four licensed enzyme immunoassay (EIA) kits for the measurement of antibody to human T-cell lymphotropic virus (HTLV) type 1, one from Organon Teknika Corp. (OTC), one from Cambridge Biotech Corp. (CBC), and two from Abbott Laboratories (the 1993 modification [Abb 93] and the 2.0 version licensed in 1995 [Abb 95]), were evaluated for sensitivity and specificity in the detection of HTLV type 2 antibody, and the results were compared with those previously obtained with earlier kit versions. The...

  8. Macrophage-specific RAM11 monoclonal antibody cross-reacts with basal cells of stratified squamous epithelia.

    OpenAIRE

    Tadeusz Cichocki; Joanna Zarzecka; Alicja Furgal-Borzych; Jan A. Litwin; Grzegorz J. Lis

    2007-01-01

    RAM11 is a mouse monoclonal anti-rabbit macrophage antibody recognizing connective tissue and vascular (atheromatous tissue) macrophages. This study demonstrates a cross-reaction of RAM11 with an unknown antigen in rabbit normal epithelial cells. Formalin-fixed, paraffin sections of the New Zealand White rabbit normal skin, oral mucosa, esophagus, small intestine and lung were immunostained with RAM11 antibody followed by goat anti-mouse Cy-3-conjugated antiglobulin. RAM11-positive immunofluo...

  9. Resolution of acute malarial infections by T cell-dependent non-antibody-mediated mechanisms of immunity.

    OpenAIRE

    Cavacini, L A; Parke, L A; Weidanz, W P

    1990-01-01

    While it is generally accepted that acute blood stage malarial infections are resolved through the actions of protective antibodies, we observed that resistance to acute infection with Plasmodium chabaudi adami was mediated by T cell-dependent cellular immune mechanisms independent of antibody. We now report that acute blood stage infections caused by three additional murine hemoprotozoan parasites, Plasmodium vinckei petteri, Plasmodium chabaudi chabaudi, and Babesia microti, appear to be co...

  10. Specific antibody-receptor interactions trigger InlAB-independent uptake of listeria monocytogenes into tumor cell lines

    Directory of Open Access Journals (Sweden)

    Hotz Christian

    2011-07-01

    Full Text Available Abstract Background Specific cell targeting is an important, yet unsolved problem in bacteria-based therapeutic applications, like tumor or gene therapy. Here, we describe the construction of a novel, internalin A and B (InlAB-deficient Listeria monocytogenes strain (Lm-spa+, which expresses protein A of Staphylococcus aureus (SPA and anchors SPA in the correct orientation on the bacterial cell surface. Results This listerial strain efficiently binds antibodies allowing specific interaction of the bacterium with the target recognized by the antibody. Binding of Trastuzumab (Herceptin® or Cetuximab (Erbitux® to Lm-spa+, two clinically approved monoclonal antibodies directed against HER2/neu and EGFR/HER1, respectively, triggers InlAB-independent internalization into non-phagocytic cancer cell lines overexpressing the respective receptors. Internalization, subsequent escape into the host cell cytosol and intracellular replication of these bacteria are as efficient as of the corresponding InlAB-positive, SPA-negative parental strain. This specific antibody/receptor-mediated internalization of Lm-spa+ is shown in the murine 4T1 tumor cell line, the isogenic 4T1-HER2 cell line as well as the human cancer cell lines SK-BR-3 and SK-OV-3. Importantly, this targeting approach is applicable in a xenograft mouse tumor model after crosslinking the antibody to SPA on the listerial cell surface. Conclusions Binding of receptor-specific antibodies to SPA-expressing L. monocytogenes may represent a promising approach to target L. monocytogenes to host cells expressing specific receptors triggering internalization.

  11. γδ T cell-mediated antibody-dependent cellular cytotoxicity with CD19 antibodies assessed by an impedance-based label-free real-time cytotoxicity assay

    OpenAIRE

    Ursula Jördis Eva Seidel; Fabian eVogt; Ludger eGrosse-Hovest; Gundram eJung; Rupert eHandgretinger; Peter eLang

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation (SCT) strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T ce...

  12. Quality and quantity of TFH cells are critical for broad antibody development in SHIVAD8 infection.

    Science.gov (United States)

    Yamamoto, Takuya; Lynch, Rebecca M; Gautam, Rajeev; Matus-Nicodemos, Rodrigo; Schmidt, Stephen D; Boswell, Kristin L; Darko, Sam; Wong, Patrick; Sheng, Zizhang; Petrovas, Constantinos; McDermott, Adrian B; Seder, Robert A; Keele, Brandon F; Shapiro, Lawrence; Douek, Daniel C; Nishimura, Yoshiaki; Mascola, John R; Martin, Malcolm A; Koup, Richard A

    2015-07-29

    Broadly neutralizing antibodies (bNAbs) protect against HIV-1 infection, yet how they are generated during chronic infection remains unclear. It is known that T follicular helper (TFH) cells are needed to promote affinity maturation of B cells during an immune response; however, the role of TFH during HIV-1 infection is undefined within lymph node germinal centers (GCs). We use nonhuman primates to investigate the relationship in the early stage of chronic SHIVAD8 (simian-human immunodeficiency virus AD8) infection between envelope (Env)-specific TFH cells, Env-specific B cells, virus, and the generation of bNAbs during later infection. We found that both the frequency and quality of Env-specific TFH cells were associated with an expansion of Env-specific immunoglobulin G-positive GC B cells and broader neutralization across HIV clades. We also found a correlation between breadth of neutralization and the degree of somatic hypermutation in Env-specific memory B cells. Finally, we observed high viral loads and greater diversity of Env sequences in rhesus macaques that developed cross-reactive neutralization as compared to those that did not. These studies highlight the importance of boosting high-quality TFH populations as part of a robust vaccine regimen aimed at eliciting bNabs. PMID:26223303

  13. [Effect of thalassemia panel reactive antibody on proliferation and apoptosis of cord blood CD34(+) cells].

    Science.gov (United States)

    Yang, Xing-Ge; Lu, Xue-Liang; Xu, Lü-Hong; Fang, Jian-Pei

    2012-02-01

    The study was purposed to explore the effect of panel reactive antibody (PRA) serum from patients with β-thalassemia on proliferation and apoptosis of the CD34(+)cells from cord blood and its mechanism. CD34(+) cells of umbilical cord blood were incubated with different sera and complement respectively. After incubation, the samples were centrifuged and the supernatants were collected for lactate dehydrogenase (LDH) detection, and the CD34(+) cells were harvested and measured for the apoptosis by flow cytometry with Annexin V/PI. The intracellular DNA synthesis were also quantified by [(3)H]TdR incorporation using liquid scintillation counter. The results showed that concentration of LDH in PRA positive groups was higher as compared with control group, and the DNA synthesis of CD34(+) cells in PRA positive groups were inhibited. There were no differences in the percentage of cell apoptosis and necrosis among different groups. It is concluded that thalassemic serum PRA impairs the cell membrane, inhibits the DNA synthesis, which can be increased by addition of the complement, but PRA had no significant effect on apoptosis of CD34(+) cells. PMID:22391181

  14. Microarray-based MALDI-TOF mass spectrometry enables monitoring of monoclonal antibody production in batch and perfusion cell cultures.

    Science.gov (United States)

    Steinhoff, Robert F; Karst, Daniel J; Steinebach, Fabian; Kopp, Marie R G; Schmidt, Gregor W; Stettler, Alexander; Krismer, Jasmin; Soos, Miroslav; Pabst, Martin; Hierlemann, Andreas; Morbidelli, Massimo; Zenobi, Renato

    2016-07-15

    Cell culture process monitoring in monoclonal antibody (mAb) production is essential for efficient process development and process optimization. Currently employed online, at line and offline methods for monitoring productivity as well as process reproducibility have their individual strengths and limitations. Here, we describe a matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)-based on a microarray for mass spectrometry (MAMS) technology to rapidly monitor a broad panel of analytes, including metabolites and proteins directly from the unpurified cell supernatant or from host cell culture lysates. The antibody titer is determined from the intact antibody mass spectra signal intensity relative to an internal protein standard spiked into the supernatant. The method allows a semi-quantitative determination of light and heavy chains. Intracellular mass profiles for metabolites and proteins can be used to track cellular growth and cell productivity. PMID:26707204

  15. Macrophage-specific RAM11 monoclonal antibody cross-reacts with basal cells of stratified squamous epithelia.

    Directory of Open Access Journals (Sweden)

    Tadeusz Cichocki

    2007-10-01

    Full Text Available RAM11 is a mouse monoclonal anti-rabbit macrophage antibody recognizing connective tissue and vascular (atheromatous tissue macrophages. This study demonstrates a cross-reaction of RAM11 with an unknown antigen in rabbit normal epithelial cells. Formalin-fixed, paraffin sections of the New Zealand White rabbit normal skin, oral mucosa, esophagus, small intestine and lung were immunostained with RAM11 antibody followed by goat anti-mouse Cy-3-conjugated antiglobulin. RAM11-positive immunofluorescence was observed in basal layer cells of stratified squamous epithelia (skin, oral mucosa, esophagus. No RAM11 immunostaining was found in any cells of simple (intestinal, bronchial epithelia. These findings show that basal cells of stratified squamous keratinized and non-keratinized epithelia of the rabbit express an antigenic epitope which is common with that of macrophage antigen recognized by RAM11 monoclonal antibody.

  16. Macrophage-specific RAM11 monoclonal antibody cross-reacts with basal cells of stratified squamous epithelia.

    Science.gov (United States)

    Lis, Grzegorz J; Litwin, Jan A; Furgal-Borzych, Alicja; Zarzecka, Joanna; Cichocki, Tadeusz

    2007-01-01

    RAM11 is a mouse monoclonal anti-rabbit macrophage antibody recognizing connective tissue and vascular (atheromatous tissue) macrophages. This study demonstrates a cross-reaction of RAM11 with an unknown antigen in rabbit normal epithelial cells. Formalin-fixed, paraffin sections of the New Zealand White rabbit normal skin, oral mucosa, esophagus, small intestine and lung were immunostained with RAM11 antibody followed by goat anti-mouse Cy-3-conjugated antiglobulin. RAM11-positive immunofluorescence was observed in basal layer cells of stratified squamous epithelia (skin, oral mucosa, esophagus). No RAM11 immunostaining was found in any cells of simple (intestinal, bronchial) epithelia. These findings show that basal cells of stratified squamous keratinized and non-keratinized epithelia of the rabbit express an antigenic epitope which is common with that of macrophage antigen recognized by RAM11 monoclonal antibody. PMID:17951172

  17. Haemolytic complement activity, C3 and FactorB consumption in serum from chickens divergently selected for antibody responses to sheep red blood cells

    NARCIS (Netherlands)

    Parmentier, H.K.; Baelmans, R.; Nieuwland, M.G.B.; Dorny, P.; Demey, F.

    2002-01-01

    Antibody responses, serum complement haemolytic activity, and complement component C3 and Factor B consumption were studied in chickens divergently selected for high and low antibody responses to sheep red blood cells, and in a randombred control line. Significantly higher total and IgG antibody res

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

    Directory of Open Access Journals (Sweden)

    Imperiale Valentina

    2007-07-01

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

  19. Analysis by Flow Cytometry of B-Cell Activation and Antibody Responses Induced by Toll-Like Receptors.

    Science.gov (United States)

    Pone, Egest J

    2016-01-01

    Toll-like receptors (TLRs) are expressed in B lymphocytes and contribute to B-cell activation, antibody responses, and their maturation. TLR stimulation of mouse B cells induces class switch DNA recombination (CSR) to isotypes specified by cytokines, and also induces formation of IgM(+) as well as class-switched plasma cells. B-cell receptor (BCR) signaling, while on its own inducing limited B-cell proliferation and no CSR, can enhance CSR driven by TLRs. Particular synergistic or antagonistic interactions among TLR pathways, BCR, and cytokine signaling can have important consequences for B-cell activation, CSR, and plasma cell formation. This chapter outlines protocols for the induction and analysis of B-cell activation and antibody production by TLRs with or without other stimuli. PMID:26803633

  20. Comparison of multiple assays for detecting human antibodies directed against antigens on normal and malignant tissue culture cells

    International Nuclear Information System (INIS)

    Four separate assays of human antibody reactivity to four separate normal and malignant human tissue culture cells lines from two patients have been evaluated using a single highly-reactive allogeneic serum. The visual end-point cytolysis assay and the chromium-51 release assay were equally sensitive in measuring complement mediated antibody cytotoxicity and both were far more sensitive than a trypan blue dye exclusion assay. The assay of antibody reactivity by hemadsorption technique was about 10 times more sensitive than any of the cytotoxicity assays. This latter assay measures only IgG antibody however. These assays showed that cell lines from different patients may differ greatly in 'reactivity' to an allogeneic serum and emphasized the importance of utilizing tumor and normal cells from the same patient when using tissue culture cells to search for tumor specific reactivity. These observations emphasize the importance of utilizing multiple assays against paired normal and malignant cells from the same patient to be certain of the specificity and magnitude of the measured antibody

  1. Cells of the J774 macrophage cell line are primed for antibody-dependent cell-mediated cytotoxicity following exposure to γ-irradiation

    International Nuclear Information System (INIS)

    Activation of macrophages (M phi) for host defense against tumor cells follows a sequence of priming events followed by an initiating stimulus that results in production and release of cytotoxic molecules that mediate target cell killing. The authors have developed a model to study specific macrophage cytotoxicity in vitro utilizing a cultured murine M phi cell line, J774. Specific cytotoxicity of cultured human gastrointestinal tumor cells is achieved in the presence of murine IgG2a monoclonal antibody (mAb) 17-1-A. The ability of these cells to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) is greatly enhanced following gamma-irradiation. ADCC can be demonstrated at mAb 17-1-A concentrations greater than or equal to 1 microgram/ml and effector/target cell ratios greater than or equal to 2. Exposure to doses greater than or equal to 10 Gy of gamma-irradiation increases ADCC threefold. Varying the duration from J774 M phi exposure to γ-irradiation until addition of antibody-coated target cells showed that the primed state for ADCC is stable for at least 8 days but approximately 24 hr is required for complete development of the primed state. mAb-dependent target cell death begins 8 hr after addition of mAb and labeled target cells to primed effector cells and is complete by 24 hr. Incubation of unirradiated J774 M phi effector cells with recombinant murine interferon-γ (rmIFN-γ) also results in enhanced ADCC, but the extent of target cell killing achieved is less than that following priming by γ-irradiation. Concomitant priming of γ-irradiated J774 M phi with rmIFN-γ increases the extent of ADCC. Further study of irradiated J774 cells may elucidate the molecular pathways utilized by M phi for achieving and maintaining the primed state for ADCC

  2. Cells of the J774 macrophage cell line are primed for antibody-dependent cell-mediated cytotoxicity following exposure to. gamma. -irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Duerst, R.; Werberig, K. (University of Rochester Medical Center, New York (USA))

    1991-09-01

    Activation of macrophages (M phi) for host defense against tumor cells follows a sequence of priming events followed by an initiating stimulus that results in production and release of cytotoxic molecules that mediate target cell killing. The authors have developed a model to study specific macrophage cytotoxicity in vitro utilizing a cultured murine M phi cell line, J774. Specific cytotoxicity of cultured human gastrointestinal tumor cells is achieved in the presence of murine IgG2a monoclonal antibody (mAb) 17-1-A. The ability of these cells to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) is greatly enhanced following gamma-irradiation. ADCC can be demonstrated at mAb 17-1-A concentrations greater than or equal to 1 microgram/ml and effector/target cell ratios greater than or equal to 2. Exposure to doses greater than or equal to 10 Gy of gamma-irradiation increases ADCC threefold. Varying the duration from J774 M phi exposure to {gamma}-irradiation until addition of antibody-coated target cells showed that the primed state for ADCC is stable for at least 8 days but approximately 24 hr is required for complete development of the primed state. mAb-dependent target cell death begins 8 hr after addition of mAb and labeled target cells to primed effector cells and is complete by 24 hr. Incubation of unirradiated J774 M phi effector cells with recombinant murine interferon-{gamma} (rmIFN-{gamma}) also results in enhanced ADCC, but the extent of target cell killing achieved is less than that following priming by {gamma}-irradiation. Concomitant priming of {gamma}-irradiated J774 M phi with rmIFN-{gamma} increases the extent of ADCC. Further study of irradiated J774 cells may elucidate the molecular pathways utilized by M phi for achieving and maintaining the primed state for ADCC.

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

    Directory of Open Access Journals (Sweden)

    Isabel Fofana

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

  4. Reactions of peripheral blood mononuclear cells (PBMC) of camels with monoclonal antibodies against ruminant leukocytes.

    Science.gov (United States)

    Ungar-Waron, H; Yagil, R; Brenner, J; Paz, R; Partosh, N; Van Creveld, C; Lubashevsky, E; Trainin, Z

    2003-03-01

    The particular immune system of the camel has been but little investigated. In this work circulating camel peripheral blood mononuclear cells (PBMC) were studied by flow cytometry. Monoclonal antibodies (mAbs) raised against ruminant leukocytes were used for the detection of cell surface antigens. Monoclonals to T-cell markers, CD4 (CACT138A) and CD8 (CACT80C), exhibited no reactivity towards camel PBMC in contrast to their reactivity to PBMC of other ruminant species and those of cattle in particular. A relatively high percentage (29.1+/-8.9%) of camel PBMC reacted with a non-immunoglobulin cell surface marker, B-B2, comparable to the reactivity of bovine PBMC. The B-B7 cell marker revealed 22.4+/-10.0% of reactive camel PBMC while the CD45 leukocyte common antigen was identified only on 19.4+/-3.1% of camel PBMC as compared to 74.7+/-4.9% for bovine PBMC. IgM (PIg45A) was detected on 9.1+/-1.4% of camel PBMC and on 46.6+/-19.5% of the bovine PBMC. Double fluorescent labeling with two B-cell markers and an anti-ruminant lambda light-chain mAb revealed 7-9% of cells bearing both B and lambda L-chain markers. Light chain reactivity was also assessed using an anti-goat F(ab')(2) antiserum. The values obtained, 14.3+/-5.8% for the camel and 47.8+/-2.7% for the cattle, are close to the values observed for surface IgM. These data suggest that camels, like other ruminants, possess L-chain bearing cells of the B-cell lineage. However, in the camel, Igs are different in that in addition to regular four chain Igs, about 65% of them possess two heavy chain Igs devoid of light chains. Because different sets of V(H) gene segments are used by four and two chain Igs, it is possible that there might be two lineages of B-cells each secreting a different form of antibodies. PMID:12493494

  5. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian;

    2015-01-01

    Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream proces...

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

    Science.gov (United States)

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

    1985-04-01

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

  7. Cell Surface Glycoprotein of Reactive Stromal Fibroblasts as a Potential Antibody Target in Human Epithelial Cancers

    Science.gov (United States)

    Garin-Chesa, Pilar; Old, Lloyd J.; Rettig, Wolfgang J.

    1990-09-01

    The F19 antigen is a cell surface glycoprotein (M_r, 95,000) of human sarcomas and proliferating, cultured fibroblasts that is absent from resting fibroblasts in normal adult tissues. Normal and malignant epithelial cells are also F19^-. The present immunohistochemical study describes induction of F19 in the reactive mesenchyme of epithelial tumors. F19^+ fibroblasts were found in primary and metastatic carcinomas, including colorectal (18 of 18 cases studied), breast (14/14), ovarian (21/21), bladder (9/10), and lung carcinomas (13/13). In contrast, the stroma of benign colorectal adenomas, fibrocystic disease and fibroadenomas of breast, benign prostate hyperplasia, in situ bladder carcinomas, and benign ovarian tumors showed no or only moderate numbers of F19^+ fibroblasts. Analysis of dermal incision wounds revealed that F19 is strongly induced during scar formation. Comparison of F19 with the extracellular matrix protein tenascin, a putative marker of tumor mesenchyme, showed a cellular staining pattern for F19 vs. the extracellular matrix pattern for tenascin and widespread expression of tenascin in F19^- normal tissues and benign tumors. Our results suggest that the F19^+ phenotype correlates with specialized fibroblast functions in wound healing and malignant tumor growth. Because of its abundance in tumor mesenchyme, F19 may serve as a target for antibodies labeled with radioisotopes or toxic agents, or inflammatogenic antibodies, in carcinoma patients.

  8. Frequencies and Specificities of “Enzyme-Only” Detected Erythrocyte Alloantibodies in Patients Hospitalized in Austria: Is an Enzyme Test Required for Routine Red Blood Cell Antibody Screening?

    OpenAIRE

    Dietmar Enko; Claudia Habres; Franz Wallner; Barbara Mayr; Gabriele Halwachs-Baumann

    2014-01-01

    The aim of this study was to determine the frequencies and specificities of “enzyme-only” detected red blood cell (RBC) alloantibodies in the routine antibody screening and antibody identification in patients hospitalized in Austria. Routine blood samples of 2420 patients were investigated. The antibody screening was performed with a 3-cell panel in the low-ionic strength saline- (LISS-) indirect antiglobulin test (IAT) and with an enzyme-pretreated (papain) 3-cell panel fully automated on th...

  9. Human Monoclonal Islet Cell Antibodies From a Patient with Insulin- Dependent Diabetes Mellitus Reveal Glutamate Decarboxylase as the Target Antigen

    Science.gov (United States)

    Richter, Wiltrud; Endl, Josef; Eiermann, Thomas H.; Brandt, Michael; Kientsch-Engel, Rosemarie; Thivolet, Charles; Jungfer, Herbert; Scherbaum, Werner A.

    1992-09-01

    The autoimmune phenomena associated with destruction of the β cell in pancreatic islets and development of type 1 (insulin-dependent) diabetes mellitus (IDDM) include circulating islet cell antibodies. We have immortalized peripheral blood lymphocytes from prediabetic individuals and patients with newly diagnosed IDDM by Epstein-Barr virus transformation. IgG-positive cells were selected by anti-human IgG-coupled magnetic beads and expanded in cell culture. Supernatants were screened for cytoplasmic islet cell antibodies using the conventional indirect immunofluorescence test on cryostat sections of human pancreas. Six islet cell-specific B-cell lines, originating from a patient with newly diagnosed IDDM, could be stabilized on a monoclonal level. All six monoclonal islet cell antibodies (MICA 1-6) were of the IgG class. None of the MICA reacted with human thyroid, adrenal gland, anterior pituitary, liver, lung, stomach, and intestine tissues but all six reacted with pancreatic islets of different mammalian species and, in addition, with neurons of rat cerebellar cortex. MICA 1-6 were shown to recognize four distinct antigenic epitopes in islets. Islet cell antibody-positive diabetic sera but not normal human sera blocked the binding of the monoclonal antibodies to their target epitopes. Immunoprecipitation of 35S-labeled human islet cell extracts revealed that a protein of identical size to the enzyme glutamate decarboxylase (EC 4.1.1.15) was a target of all MICA. Furthermore, antigen immunotrapped by the MICA from brain homogenates showed glutamate decarboxylase enzyme activity. MICA 1-6 therefore reveal glutamate decarboxylase as the predominant target antigen of cytoplasmic islet cell autoantibodies in a patient with newly diagnosed IDDM.

  10. Antibody and T cell responses to Fusobacterium nucleatum and Treponema denticola in health and chronic periodontitis.

    Directory of Open Access Journals (Sweden)

    Jieun Shin

    Full Text Available The characteristics of the T cell response to the members of oral flora are poorly understood. We characterized the antibody and T cell responses to FadA and Td92, adhesins from Fusobacterium nucleatum, an oral commensal, and Treponema denticola, a periodontal pathogen, respectively. Peripheral blood and saliva were obtained from healthy individuals and patients with untreated chronic periodontitis (CP, n = 11 paris and after successful treatment of the disease (n = 9. The levels of antigen-specific antibody were measured by ELISA. In plasma, IgG1 was the most abundant isotype of Ab for both Ags, followed by IgA and then IgG4. The levels of FadA-specific salivary IgA (sIgA were higher than Td92-specific sIgA and the FadA-specific IgA levels observed in plasma. However, the periodontal health status of the individuals did not affect the levels of FadA- or Td92-specific antibody. Even healthy individuals contained FadA- and Td92-specific CD4(+ T cells, as determined by the detection of intracytoplasmic CD154 after short-term in vitro stimulation of peripheral blood mononuclear cells (PBMCs with the antigens. Patients with CP tended to possess increased numbers of FadA- and Td92-specific CD4(+ T cells but reduced numbers of Td92-specific Foxp3(+CD4(+ Tregs than the healthy subjects. Both FadA and Td92 induced the production of IFNγ and IL-10 but inhibited the secretion of IL-4 by PBMCs. In conclusion, F. nucleatum induced Th3 (sIgA- and Th1 (IFNγ and IgG1-dominant immune responses, whereas T. denticola induced a Th1 (IFNγ and IgG1-dominant response. This IFNγ-dominant cytokine response was impaired in CP patients, and the Td92-induced IFNγ levels were negatively associated with periodontal destruction in patients. These findings may provide new insights into the homeostatic interaction between the immune system and oral bacteria and the pathogenesis of periodontitis.

  11. Preparation of monoclonal antibody against celangulin V and immunolocalization of receptor in the oriental armyworm, Mythimna separata walker (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Qi, Zhijun; Xue, Xiaoping; Wu, Wenjun; Zhang, Jiwen; Yang, Runya

    2006-10-01

    The botanical insecticide celangulin V (CA-V) is an insect digestive poison acting on midgut tissue of the target insect larvae. With the aim of localizing the receptor enacted by CA-V, monoclonal antibodies (MAbs) specific to the compound were developed. A hapten was synthesized by introducing a succinoyl into the CA-V structure and conjugated with three carrier proteins. From mice immunized with one conjugate, three MAbs were obtained with a potential capacity of detecting protein-bound residue forms of CA-V in the biological tissues. The oriental armyworm larvae ingested CA-V were examined by the technique of immuno-electron-microscopy (IEM) using the anti-CA-V MAb as the primary antibody and goat anti-mouse/IgG labeled with colloidal gold as the secondary antibody. Electron micrographs of the armyworm midgut tissues showed that the CA-V was associated with the midgut epithelia of the insects. These results demonstrated the existence of a receptor enacted by CA-V on the midgut cells of the oriental armyworm larvae. PMID:17002428

  12. Bispecific antibodies.

    Science.gov (United States)

    Kontermann, Roland E; Brinkmann, Ulrich

    2015-07-01

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

  13. Detection of lymphocystis disease virus infection to flounder gill cells in vitro by monoclonal antibodies

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Flounder gill (FG) cells were used to isolate lymphocystis disease virus (LCDV) and two monoclonal antibodies (Mabs) (1A8 and 3G3) against LCDV were used to trace LCDV infection to FG cells. FG monolayer cells was inoculated with LCDV supernatant, obtained from lymphocystis cells of diseased flounder, Paralichthys olivaceus. LCDV infection was detected with Mabs employing immunocytochemical assay (ICA) and indirect immunofluorescence assay test (ⅡFAT) technique. Detected by ⅡFAT, they were specific for LCDV. The results of experimental infection illustrated that FG cells was sensitive to LCDV, and showed virus-infection positive detected by ICA. Cytopathic effect (CPE) occurred 1-2 days post inoculation (PI), and half tissue culture infection dosage (TCID50) of virus supernatant was 22.57 per 40μl. Tracing by ⅡFAT showed that LCDV positive signal first appeared at the cell membrane immediately PI, and then in cytoplasm at 24h PI, it reached the strongest positive at 48-72 h PI, and began to decrease at 96h PI.

  14. Radioimmunoimaging in human transitional cell carcinoma xenografted nude mice with monoclonal antibody L4B4

    International Nuclear Information System (INIS)

    The monoclonal antibody L4B4 against transitional cell carcinoma (TCC) was prepared and radioimmunoimaging (RII) was studied in nude mice bearing human TCC using L4B4. L4B4 was identified in vitro by immunohistochemistry. Radioimmunoimaging was performed in human transitional cell carcinoma xenografted nude mice. Immunohistochemistry study showed that L4B4 had high specificity for TCC (23/24), compared to that for other malignant tumors (2/24) and benign tumors (0/7). RII study showed that xenografted tumor was demonstrated clearly on the 3rd and 5th day after injection of 125I labeled L4B4. The T/NT was greater than 4 on the 5th day. The results indicated that L4B4 might be useful in the study of TCC and is worthy to do further investigation

  15. Anti-oxidative therapy with oral dapsone improved HCV antibody positive annular elastolytic giant cell granuloma.

    Science.gov (United States)

    Igawa, K; Maruyama, R; Katayama, I; Nishioka, K

    1997-05-01

    A 72-year-old fisherman who was positive for the HCV antibody developed an annular, erythematous, infiltrated lesions on sun-exposed areas. The lesions were diagnosed as annular elastolytic giant cell granuloma both clinically and histologically. Topical corticosteroid and cryotherapy with liquid nitrogen for several months failed to improve the lesions. We then started dapsone, a known anti-oxidant, at 50 mg/day. A month later, the margins of the erythematous lesions faded, and the infiltration gradually decreased. No recurrence has been observed for one year after the start of the therapy. Anti-oxidative therapy appears to be effective for annular elastolytic giant cell granuloma and could be an alternate therapy for refractory granulomatous disease. PMID:9198323

  16. AirLab: a cloud-based platform to manage and share antibody-based single-cell research.

    Science.gov (United States)

    Catena, Raúl; Özcan, Alaz; Jacobs, Andrea; Chevrier, Stephane; Bodenmiller, Bernd

    2016-01-01

    Single-cell analysis technologies are essential tools in research and clinical diagnostics. These methods include flow cytometry, mass cytometry, and other microfluidics-based technologies. Most laboratories that employ these methods maintain large repositories of antibodies. These ever-growing collections of antibodies, their multiple conjugates, and the large amounts of data generated in assays using specific antibodies and conditions makes a dedicated software solution necessary. We have developed AirLab, a cloud-based tool with web and mobile interfaces, for the organization of these data. AirLab streamlines the processes of antibody purchase, organization, and storage, antibody panel creation, results logging, and antibody validation data sharing and distribution. Furthermore, AirLab enables inventory of other laboratory stocks, such as primers or clinical samples, through user-controlled customization. Thus, AirLab is a mobile-powered and flexible tool that harnesses the capabilities of mobile tools and cloud-based technology to facilitate inventory and sharing of antibody and sample collections and associated validation data. PMID:27356760

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

    Directory of Open Access Journals (Sweden)

    Eva Zilian

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

  18. Antibody Reactivity of B Cells in Lupus Patients with Increased Disease Activity and ARID3a Expression

    Directory of Open Access Journals (Sweden)

    Julie M. Ward

    2015-11-01

    Full Text Available Earlier studies showed that the DNA-binding protein, Bright/ARID3a bound to a subset of human and mouse immunoglobulin heavy chain promoters where it enhanced expression. Indeed, mice with transgenic expression of ARID3a in all B lymphocytes have expanded MZ B cells and produce anti-nuclear antibodies (ANAs. Consistent with our findings in mice, we observed that human systemic lupus erythematosus (SLE patients had expanded numbers of peripheral blood ARID3a+ B cells that were associated with increased disease activity (p = 0.0038. We hypothesized that ARID3a+ naïve B cells would eventually produce autoantibodies, explaining associations between ARID3a expression and disease activity in lupus. Unlike healthy controls, ARID3a was expressed in the naïve B cell population in SLE patients, and we hypothesized that these might represent expansions of autoreactive cells. Therefore, monoclonal antibodies were generated from single-sorted naïve B cells derived from patients with normal (ARID3aN and high (ARID3aH numbers of ARID3a+ B cells. We found that ARID3a expression did not correlate with autoantibody expression. Furthermore, measures of antigen specificities of autoreactive antibodies did not reveal skewing toward particular proteins. These data suggest that the association of increased disease activity in SLE with numbers of ARID3a+ B lymphocytes may be mediated by an antibody-independent mechanism.

  19. Optimization of heavy chain and light chain signal peptides for high level expression of therapeutic antibodies in CHO cells.

    Directory of Open Access Journals (Sweden)

    Ryan Haryadi

    Full Text Available Translocation of a nascent protein from the cytosol into the ER mediated by its signal peptide is a critical step in protein secretion. The aim of this work was to develop a platform technology to optimize the signal peptides for high level production of therapeutic antibodies in CHO cells. A database of signal peptides from a large number of human immunoglobulin (Ig heavy chain (HC and kappa light chain (LC was generated. Most of the HC signal peptides contain 19 amino acids which can be divided into three domains and the LC signal peptides contain 22 amino acids. The signal peptides were then clustered according to sequence similarity. Based on the clustering, 8 HC and 2 LC signal peptides were analyzed for their impacts on the production of 5-top selling antibody therapeutics, namely, Herceptin, Avastin, Remicade, Rituxan, and Humira. The best HC and LC signal peptides for producing these 5 antibodies were identified. The optimized signal peptides for Rituxan is 2-fold better compared to its native signal peptides which are available in the public database. Substitution of a single amino acid in the optimized HC signal peptide for Avastin reduced its production significantly. Mass spectrometry analyses revealed that all optimized signal peptides are accurately removed in the mature antibodies. The results presented in this report are particularly important for the production of these 5 antibodies as biosimilar drugs. They also have the potential to be the best signal peptides for the production of new antibodies in CHO cells.

  20. Optimization of heavy chain and light chain signal peptides for high level expression of therapeutic antibodies in CHO cells.

    Science.gov (United States)

    Haryadi, Ryan; Ho, Steven; Kok, Yee Jiun; Pu, Helen X; Zheng, Lu; Pereira, Natasha A; Li, Bin; Bi, Xuezhi; Goh, Lin-Tang; Yang, Yuansheng; Song, Zhiwei

    2015-01-01

    Translocation of a nascent protein from the cytosol into the ER mediated by its signal peptide is a critical step in protein secretion. The aim of this work was to develop a platform technology to optimize the signal peptides for high level production of therapeutic antibodies in CHO cells. A database of signal peptides from a large number of human immunoglobulin (Ig) heavy chain (HC) and kappa light chain (LC) was generated. Most of the HC signal peptides contain 19 amino acids which can be divided into three domains and the LC signal peptides contain 22 amino acids. The signal peptides were then clustered according to sequence similarity. Based on the clustering, 8 HC and 2 LC signal peptides were analyzed for their impacts on the production of 5-top selling antibody therapeutics, namely, Herceptin, Avastin, Remicade, Rituxan, and Humira. The best HC and LC signal peptides for producing these 5 antibodies were identified. The optimized signal peptides for Rituxan is 2-fold better compared to its native signal peptides which are available in the public database. Substitution of a single amino acid in the optimized HC signal peptide for Avastin reduced its production significantly. Mass spectrometry analyses revealed that all optimized signal peptides are accurately removed in the mature antibodies. The results presented in this report are particularly important for the production of these 5 antibodies as biosimilar drugs. They also have the potential to be the best signal peptides for the production of new antibodies in CHO cells. PMID:25706993

  1. Radioimmunotherapy of Non-Hodgkin's Lymphoma. The interaction of radiation and antibody with lymphoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Illidge, T.M

    1999-06-01

    Whilst many patients with indolent Non-Hodgkin's Lymphoma (NHL) can achieve clinical remissions to first-line chemotherapy and/or radiotherapy, most will relapse. Current treatment options for relapsing patients are limited since most patients become resistant to repeated chemotherapy. Death usually occurs within 10 years of diagnosis. Overall, these disappointing results have not changed significantly in a quarter of a century and clearly advocate the urgent priority to research into potential new therapeutic approaches into this diverse and increasingly prevalent group of human tumours. Radioimmunotherapy (RIT) is currently under investigation as a new approach for the treatment of this disease. In this form of treatment, radionuclide-labeled monoclonal antibodies are able to deliver selective systemic irradiation by recognising tumour-associated antigens. The use of RIT with radiolabeled anti-CD20 antibodies in patients with recurrent B-cell lymphoma has resulted in extremely high rates of durable complete remissions. The optimal approach and mechanisms of action of successful RIT remain however largely unknown. The work described in this thesis has focused on clarifying some of the important determinants and mechanisms of effective RIT of syngeneic B-cell lymphoma, both in vivo and in vitro. A successful animal model of RIT in B cell lymphomas was established by initially generating a panel of antibodies against mouse B cell antigens. The in vitro characteristics of these antibodies have been compared with their subsequent performance, in biodistribution studies and RIT in vivo. For the first time in an in vivo model the relative contributions of antibody and irradiation are described. Some antibodies including anti-MHC Class II were shown to be effective delivery vehicles of low doses of Iodine-131. These antibodies, which appear to be inactive delivery vehicles can cure animals with low burdens of tumour. However antibodies such as anti-idiotype and anti

  2. [A pregnant woman with irregular erythrocyte antibodies for whom no compatible packed red blood cells were available].

    Science.gov (United States)

    Boonstra, J G; Overbeeke, M A M; de Rijke, Y B; Duvekot, J J

    2005-11-19

    A 45-year-old woman underwent a Caesarean section at a gestational age of over 32 weeks. Screening for irregular erythrocyte antibodies in the transfusion laboratory yielded a positive result. It appeared that the patient had for several years been known to have antibodies against At(a), a high-frequency antigen that may cause severe transfusion reactions when incompatible packed cells are administered. No autologous donated blood was available and the only compatible At(a)-negative unit of packed cells in the Blood Bank of the Council of Europe was damaged during the thawing process. A cell saver was therefore used during the Caesarean section, and family members were summoned for donation. This case report illustrates the necessity of a transfusion plan for pregnant women with (rare) irregular antibodies. PMID:16355577

  3. T cell regulation of the thymus-independent antibody response to trinitrophenylated-Brucella abortus (TNP-BA)

    Energy Technology Data Exchange (ETDEWEB)

    Tanay, A.; Strober, S.

    1985-06-01

    The authors have previously observed a reduction of the T cell-dependent primary antibody response to dinitrophenylated keyhole limpet hemocyanin, and an enhancement of the T cell-independent response to trinitrophenylated Brucella abortus (TNP-BA) in BALB/c mice after treatment with total lymphoid irradiation (TLI). To elucidate the relative contribution of T and B cells to the enhanced T cell-independent antibody responses after TLI, a syngeneic primary adoptive transfer system was utilized whereby irradiated hosts were reconstituted with unfractionated spleen cells or a combination of purified T and B cells from TLI-treated and untreated control mice. Antibody responses of purified splenic B cells from TLI-treated BALB/c mice (TLI/B) to TNP-BA were enhanced 10-fold as compared with those of unfractionated (UF) spleen cells or B cells from normal (NL) BALB/c mice (NL/UF and NL/B, respectively). Splenic T cells from normal animals (NL/T) suppressed the anti-TNP-BA response of TLI/B by more than 100-fold. NL/T neither suppressed nor enhanced the response of NL/B. On the other hand, T cells from TLI-treated mice (TLI/T) enhanced by 100-fold the anti-TNP-BA response of NL/B, but neither suppressed nor enhanced the response of TLI/B. Thus, T cells can regulate the T cell-independent antibody response to TNP-BA. However, experimental manipulation of the T and B cell populations is needed to demonstrate the regulatory functions.

  4. γ-Synuclein antibodies have neuroprotective potential on neuroretinal cells via proteins of the mitochondrial apoptosis pathway.

    Directory of Open Access Journals (Sweden)

    Corina Wilding

    Full Text Available The family of synuclein proteins (α, β and γ are related to neurodegenerative disease e.g. Parkinson disease and Morbus Alzheimer. Additionally, a connection between γ-synuclein and glaucoma, a neurodegenerative disease characterized by a progressive loss of retinal ganglion cells, which finally leads to blindness, exists. The reason for the development of glaucoma is still unknown. Recent studies evaluating the participation of immunological components, demonstrate complex changed antibody reactivities in glaucoma patients in comparison to healthy people, showing not only up-regulations (e.g. alpha-fodrin antibody but also down-regulations (e.g. γ-synuclein antibody of antibodies in glaucoma patients. Up-regulated antibodies could be auto-aggressive, but the role of down-regulated antibodies is still unclear. Previous studies show a significant influence of the serum and the antibodies of glaucoma patients on protein expression profiles of neuroretinal cells. The aim of this study was to investigate the effect of γ-synuclein antibody on the viability and reactive oxygen species levels of a neuroretinal cell line (RGC-5 as well as their interaction with cellular proteins. We found a protective effect of γ-synuclein antibody resulting in an increased viability (up to 15% and decreased reactive oxygen species levels (up to -12% of glutamate and oxidative stressed RGC-5. These can be traced back to anti-apoptotic altered protein expressions in the mitochondrial apoptosis pathway indicated by mass spectrometry and validated by microarray analysis such as active caspase 3, bcl-2 associated-x-protein, S100A4, voltage-dependent anion channel, extracellular-signal-regulated-kinase (down-regulated and baculoviral IAP repeat-containing protein 6, phosphorylated extracellular-signal-regulated-kinase (up-regulated. These changed protein expression are triggered by the γ-synuclein antibody internalization of RGC-5 we could see in immunohistochemical

  5. γ-Synuclein antibodies have neuroprotective potential on neuroretinal cells via proteins of the mitochondrial apoptosis pathway.

    Science.gov (United States)

    Wilding, Corina; Bell, Katharina; Beck, Sabine; Funke, Sebastian; Pfeiffer, Norbert; Grus, Franz H

    2014-01-01

    The family of synuclein proteins (α, β and γ) are related to neurodegenerative disease e.g. Parkinson disease and Morbus Alzheimer. Additionally, a connection between γ-synuclein and glaucoma, a neurodegenerative disease characterized by a progressive loss of retinal ganglion cells, which finally leads to blindness, exists. The reason for the development of glaucoma is still unknown. Recent studies evaluating the participation of immunological components, demonstrate complex changed antibody reactivities in glaucoma patients in comparison to healthy people, showing not only up-regulations (e.g. alpha-fodrin antibody) but also down-regulations (e.g. γ-synuclein antibody) of antibodies in glaucoma patients. Up-regulated antibodies could be auto-aggressive, but the role of down-regulated antibodies is still unclear. Previous studies show a significant influence of the serum and the antibodies of glaucoma patients on protein expression profiles of neuroretinal cells. The aim of this study was to investigate the effect of γ-synuclein antibody on the viability and reactive oxygen species levels of a neuroretinal cell line (RGC-5) as well as their interaction with cellular proteins. We found a protective effect of γ-synuclein antibody resulting in an increased viability (up to 15%) and decreased reactive oxygen species levels (up to -12%) of glutamate and oxidative stressed RGC-5. These can be traced back to anti-apoptotic altered protein expressions in the mitochondrial apoptosis pathway indicated by mass spectrometry and validated by microarray analysis such as active caspase 3, bcl-2 associated-x-protein, S100A4, voltage-dependent anion channel, extracellular-signal-regulated-kinase (down-regulated) and baculoviral IAP repeat-containing protein 6, phosphorylated extracellular-signal-regulated-kinase (up-regulated). These changed protein expression are triggered by the γ-synuclein antibody internalization of RGC-5 we could see in immunohistochemical stainings

  6. Monoclonal antibodies and coupling reagents to cell membrane proteins for leukocyte labeling

    International Nuclear Information System (INIS)

    Current gamma-emitting agents for tagging leukocytes, In-111 oxine or tropolone, label all cell types indiscriminantly, and nuclear localization in lymphocytes results in radiation damage. Coupling reagents and murine monoclonal antibodies (Mab) specific for cell surface antigens of human leukocytes were tried as cell labeling agents to avoid nuclear localization. 10/sup 8/ mixed human leukocytes in Hepes buffer were added to tubes coated with 5 mg of dry cyclic dianhydride of DTPA for 15 minutes at room temperature. After washing, 0.1 ml of In-111 Cl in ACD (pH 6.8) was added. After 30 minutes, a cell labeling yield of 23% was obtained. Washing the cells in an elutriation centrifuge showed that this label was irreversible. Mab for cell surface antigens of human granulocytes were labeled with 300 μCi of I-125 using the Iodobead technic and unbound activity was removed by gel column chromatography. 1-10 μg were added to 10/sup 8/ mixed leukocytes in 0.5 ml plasma or saline for 1 hr. With Mab anti-leu M4 (clone G7 E11), an IgM, the cell labeling yield was 21%, irreversible, and specific for granulocytes. With anti-human leukocyte Mab NEI-042 (clone 9.4), and IgG2a, and anti-granulocyte Mab MAS-065 (clone FMCl1) an IgG1, the cell labeling was relatively unstable. Labeling of leukocyte subpopulations with Mab is feasible, and the binding of multivalent IgM is stronger than that of other immunoglobulins. DTPA cyclic anhydride is firmly bound to cell membranes, but the labeling is non-specific

  7. Endothelial cells' activation and apoptosis induced by a subset of antibodies against human cytomegalovirus: relevance to the pathogenesis of atherosclerosis.

    Directory of Open Access Journals (Sweden)

    Claudio Lunardi

    Full Text Available BACKGROUND: Human cytomegalovirus (hCMV is involved in the pathogenesis of atherosclerosis. We have previously shown in patients with atherosclerosis that antibodies directed against the hCMV-derived proteins US28 and UL122 are able to induce endothelial cell damage and apoptosis of non-stressed endothelial cells through cross-rection with normally expressed surface molecules. Our aim was to dissect the molecular basis of such interaction and to investigate mechanisms linking innate immunity to atherosclerosis. METHODOLOGY/PRINCIPAL FINDINGS: We analysed the gene expression profiles in endothelial cells stimulated with antibodies affinity-purified against either the UL122 or the US28 peptides using the microarray technology. Microarray results were validated by quantitative PCR and by detection of proteins in the medium. Supernatant of endothelial cells incubated with antibodies was analysed also for the presence of Heat Shock Protein (HSP60 and was used to assess stimulation of Toll-Like Receptor-4 (TLR4. Antibodies against UL122 and US28 induced the expression of genes encoding for adhesion molecules, chemokines, growth factors and molecules involved in the apoptotis process together with other genes known to be involved in the initiation and progression of the atherosclerotic process. HSP60 was released in the medium of cells incubated with anti-US28 antibodies and was able to engage TLR4. CONCLUSIONS/SIGNIFICANCE: Antibodies directed against hCMV modulate the expression of genes coding for molecules involved in activation and apoptosis of endothelial cells, processes known to play a pivotal role in the pathogenesis of atherosclerosis. Moreover, endothelial cells exposed to such antibodies express HSP60 on the cell surface and release HSP60 in the medium able to activate TLR4. These data confirm that antibodies directed against hCMV-derived proteins US28 and UL122 purified from patients with coronary artery disease induce endothelial cell

  8. Nivolumab, an Anti-Programmed Cell Death-1 Antibody, Induces Fulminant Type 1 Diabetes.

    Science.gov (United States)

    Miyoshi, Yuka; Ogawa, Osamu; Oyama, Yu

    2016-01-01

    Programmed cell death-1 (PD-1), an immunoreceptor, is located on T cells and pro-B cells and interacts with its ligands to inhibit T cell activation and proliferation, thereby promoting immunological self-tolerance. Nivolumab, an anti-PD1 antibody, blocks PD-1 and can restore anticancer immune responses by abrogating PD-1 pathway-mediated T-cell inhibition. Autoimmune adverse events are expected with PD-1 therapy. Fulminant type 1 diabetes is the subtype of type 1 diabetes. The clinical feature is the extremely rapid progression of hyperglycemia and ketoacidosis. Here we describe a 66-year-old woman with advanced melanoma who was treated with nivolumab. After 4 months and six doses of the medicine, the patient was admitted to the hospital with complaints of nausea and vomiting. The laboratory data showed ketonuria, hyperglycemia (531 mg/dl), high anion gap metabolic acidosis, HbA1c (7.3%), and absence of insulin-secreting capacity. These data are compatible with the criteria of fulminant type 1 diabetes. The patient was diagnosed with diabetic ketoacidosis because of fulminant type 1 diabetes. The findings of this case indicated that nivolumab can cause fulminant type 1 diabetes. Diabetic ketoacidosis due to fulminant type 1 diabetes is potentially fatal condition. Thus, diabetic ketoacidosis due to fulminant type 1 diabetes should be considered in the differential diagnosis when patients treated with nivolumab complain of gastrointestinal symptoms. PMID:27297738

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

    Directory of Open Access Journals (Sweden)

    Gábor Szalóki

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

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Intratumoral delivery of CpG-conjugated anti-MUC1 antibody enhances NK cell anti-tumor activity.

    Science.gov (United States)

    Schettini, Jorge; Kidiyoor, Amritha; Besmer, Dahlia M; Tinder, Teresa L; Roy, Lopamudra Das; Lustgarten, Joseph; Gendler, Sandra J; Mukherjee, Pinku

    2012-11-01

    Monoclonal antibodies (mAbs) against tumor-associated antigens are useful anticancer agents. Antibody-dependent cellular cytotoxicity (ADCC) is one of the major mechanisms responsible for initiating natural killer cell (NK)-mediated killing of tumors. However, the regulation of ADCC via NK cells is poorly understood. We have investigated the cytolytic activity of NK cells against pancreatic cancer cells that were coated with an antibody directed against the human tumor antigen, Mucin-1 designated HMFG-2, either alone or conjugated to CpG oligodeoxynucleotide (CpG ODN). Conjugated antibodies were tested for their ability to elicit ADCC in vitro and in vivo against pancreatic cancer cells. NK cells cultured in the presence of immobilized CpG ODN, HMFG-2 Ab, or CpG ODN-conjugated HMFG-2 Ab were able to up-regulate perforin similarly. Interestingly, a significant higher ADCC was observed when CpG ODN-conjugated HMFG-2-coated tumor cells were co-cultured with NK cells compared to unconjugated HMFG-2 Ab or CpG ODN alone. Moreover, MyD88-deficient NK cells can perform ADCC in vitro. Furthermore, intratumoral injections of CpG ODN-conjugated HMFG-2 induced a significant reduction in tumor burden in vivo in an established model of pancreatic tumor in nude mice compared to CpG ODN or the HMFG-2 alone. Depletion of macrophages or NK cells before treatment confirmed that both cells were required for the anti-tumor response in vivo. Results also suggest that CpG ODN and HMFG-2 Ab could be sensed by NK cells on the mAb-coated tumor cells triggering enhanced ADCC in vitro and in vivo. PMID:22543528

  12. A new cell line for high throughput HIV-specific antibody-dependent cellular cytotoxicity (ADCC) and cell-to-cell virus transmission studies

    Science.gov (United States)

    Orlandi, Chiara; Flinko, Robin; Lewis, George K.

    2016-01-01

    Several lines of evidence indicate that antibody-dependent cellular cytotoxicity (Wren et al., 2013) is important in the pathogenesis of HIV-1 infection. Namely, ADCC is induced during natural HIV-1 infection or in HIV-1 vaccine studies, the latter demonstrated by the RV144 vaccine trial. To expedite the assessment of ADCC in studies of HIV, we have developed a high throughput assay. We have optimized the rapid fluorometric antibody-mediated cytotoxicity assay (RFADCC) by transfecting the EGFP-CEM-NKr cell line to constitutively express SNAP-tagged CCR5. This cell line can then serve as a source of HIV-specific targets when coated with monomeric gp120, spinoculated with inactivated intact virions, infected by cell-free viral diffusion or infected by cell-to-cell transmission of virus. The optimized strategy has two significant advantages over the original RFADCC method: First, the preparation of detectable target cells is less labor intensive and faster as it does not rely on multiple staining and washing steps for target cells. Second, because the target cell markers GFP and SNAP are constitutively expressed, the assay provides highly reproducible data. These strengths make the optimized RFADCC assay suitable not only for studies of HIV-1 specific cytotoxicity but also for studies of cell–cell transmission of virus. In conclusion, this assay provides a new generation T cell line that can expedite large clinical studies as well as research studies in humans or non-human primates. PMID:26969387

  13. Antibodies and Selection of Monoclonal Antibodies.

    Science.gov (United States)

    Hanack, Katja; Messerschmidt, Katrin; Listek, Martin

    2016-01-01

    Monoclonal antibodies are universal binding molecules with a high specificity for their target and are indispensable tools in research, diagnostics and therapy. The biotechnological generation of monoclonal antibodies was enabled by the hybridoma technology published in 1975 by Köhler and Milstein. Today monoclonal antibodies are used in a variety of applications as flow cytometry, magnetic cell sorting, immunoassays or therapeutic approaches. First step of the generation process is the immunization of the organism with appropriate antigen. After a positive immune response the spleen cells are isolated and fused with myeloma cells in order to generate stable, long-living antibody-producing cell lines - hybridoma cells. In the subsequent identification step the culture supernatants of all hybridoma cells are screened weekly for the production of the antibody of interest. Hybridoma cells producing the antibody of interest are cloned by limited dilution till a monoclonal hybridoma is found. This is a very time-consuming and laborious process and therefore different selection strategies were developed since 1975 in order to facilitate the generation of monoclonal antibodies. Apart from common automation of pipetting processes and ELISA testing there are some promising approaches to select the right monoclonal antibody very early in the process to reduce time and effort of the generation. In this chapter different selection strategies for antibody-producing hybridoma cells are presented and analysed regarding to their benefits compared to conventional limited dilution technology. PMID:27236550

  14. Understanding Transcriptional Enhancement in Monoclonal Antibody-Producing Chinese Hamster Ovary Cells

    Science.gov (United States)

    Nicoletti, Sarah E.

    With the demand for monoclonal antibody (mAB) therapeutics continually increasing, the need to better understand what makes a high productivity clone has gained substantial interest. Monoclonal antibody producing Chinese hamster ovary (CHO) cells with different productivities were provided by a biopharmaceutical company for investigation. Gene copy numbers, mRNA levels, and mAb productivities were previously determined for two low producing clones and their amplified progeny. These results showed an increase in mRNA copy number in amplified clones, which correlated to the observed increases in specific productivity of these clones. The presence of multiple copies of mRNA per one copy of DNA in the higher productivity clones has been coined as transcriptional enhancement. The methylation status of the CMV promoter as well as transcription factor/promoter interactions were evaluated to determine the cause of transcriptional enhancement. Methylation analysis via bisulfite sequencing revealed no significant difference in overall methylation status of the CMV promoter. These data did, however, reveal the possibility of differential interactions of transcription factors between the high and low productivity cell clones. This finding was further supported by chromatin immunoprecipitations previously performed in the lab, as well as literature studies. Transcription activator-like effector (TALE) binding proteins were constructed and utilized to selectively immunoprecipitate the CMV promoter along with its associated transcription factors in the different CHO cell clones. Cells were transfected with the TALE proteins, harvested and subjected to a ChIP-like procedure. Results obtained from the TALE ChIP demonstrated the lack of binding of the protein to the promoter and the need to redesign the TALE. Overall, results obtained from this study were unable to give a clear indication as to the causes of transcriptional enhancement in the amplified CHO cell clones. Further

  15. Structural evidence for evolution of shark Ig new antigen receptor variable domain antibodies from a cell-surface receptor

    OpenAIRE

    Streltsov, V. A.; Varghese, J N; Carmichael, J A; Irving, R A; Hudson, P.J.; Nuttall, S D

    2004-01-01

    The Ig new antigen receptors (IgNARs) are single-domain antibodies found in the serum of sharks. Here, we report 2.2- and 2.8-Å structures of the type 2 IgNAR variable domains 12Y-1 and 12Y-2. Structural features include, first, an Ig superfamily topology transitional between cell adhesion molecules, antibodies, and T cell receptors; and, second, a vestigial complementarity-determining region 2 at the “bottom” of the molecule, apparently discontinuous from the antigen-binding paratope and sim...

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

    OpenAIRE

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

    1983-01-01

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

  17. Clinical value of imaging using antibody to alpha fetoprotein in germ cell tumours

    International Nuclear Information System (INIS)

    Germ cell tumours (GCT) producing alpha fetoprotein (aFP) can be imaged by external scintigraphy after intraveneous administration of radiolabelled antibody directed against aFP. Antibody imaging (AI) by this method was used in an attempt to guide surgical resection of deposits of drug-resistant or recurrent GCT. 30 patients with GCT and raised aFP in whom site of tumour was not known were investigated by AI and conventional imaging methods. All but one were heavily pretreated. Where tumour appeared localised, resection was attempted. Tumour was found in all sites positive by both AI and conventional imaging. AI produced false-positive results in one of 30 patients and false-negative results in 9 patients. Computerised tomography was false-positive in one case and false-negative in three. In these patients, AI gave true-negative and true-positive results, respectively. Of 11 patients with positive AI in whom resection was attempted, 6 achieved sustained complete response with up to 5 years follow-up. We conclude AI and conventional imaging methods to be complementary in selection for surgery of patients with drug-resistant or recurrent GCT. (orig.)

  18. Host cell protein impurities in chromatographic polishing steps for monoclonal antibody purification.

    Science.gov (United States)

    Levy, Nicholas E; Valente, Kristin N; Lee, Kelvin H; Lenhoff, Abraham M

    2016-06-01

    Downstream purification of monoclonal antibodies (mAbs) is normally performed using a platform process that is empirically tuned to optimize impurity removal for each new product. A more fundamental understanding of impurities and the product itself would provide insights into the rational design of efficient downstream processes. This work examines the chromatographic properties of Chinese hamster ovary host cell protein (HCP) impurities in non-affinity chromatographic resins commonly used in polishing steps for monoclonal antibody purification: ion-exchange, hydrophobic interaction, and multimodal. Using proteomic analysis, the specific HCP impurities that elute close to mAb products are identified for these resins at typical downstream processing conditions. Additionally, the interactions of HCP impurities with mAb products are profiled to determine the total extent of product association and the specific HCP species that form associative complexes under conditions encountered in polishing columns. Product association and co-elution were both identified as viable mechanisms of HCP retention for the non-affinity resins tested here. A relatively large sub-population of HCP impurities was found to co-elute or associate with mAbs in each polishing column, but only a small population of HCPs-including lipoprotein lipase, chrondroitin sulfate proteoglycan 4, nidogen-1, and SPARC-were identified as difficult to remove across an entire downstream mAb process. Biotechnol. Bioeng. 2016;113: 1260-1272. © 2015 Wiley Periodicals, Inc. PMID:26550778

  19. Toll-like receptor activation enhances cell-mediated immunity induced by an antibody vaccine targeting human dendritic cells

    Directory of Open Access Journals (Sweden)

    Berger Marc A

    2007-01-01

    Full Text Available Abstract Previously, we have successfully targeted the mannose receptor (MR expressed on monocyte-derived dendritic cells (DCs using a fully human MR-specific antibody, B11, as a vehicle to deliver whole protein tumor antigens such as the human chorionic gonadotropin hormone (hCGβ. Since MRs play a role in bridging innate immunity with adaptive immunity we have explored several toll-like receptor (TLR-specific ligands that may synergize with MR targeting and be applicable as adjuvants in the clinic. We demonstrate that antigen-specific helper and cytolytic T cells from both healthy donors and cancer patients were effectively primed with B11-hCGβ-treated autologous DCs when a combination of one or several TLR ligands is used. Specifically, concomitant signaling of DCs via TLR3 with dsRNA (poly I:C and DC TLR 7/8 with Resiquimod (R-848, respectively, elicited efficient antigen presentation-mediated by MR-targeting. We demonstrate that MR and TLRs contribute towards maturation and activation of DCs by a mechanism that may be driven by a combination of adjuvant and antibody vaccines that specifically deliver antigenic targets to DCs.

  20. Virus-Specific Antibody, in the Absence of T Cells, Mediates Demyelination in Mice Infected with a Neurotropic Coronavirus

    OpenAIRE

    Kim, Taeg S.; Perlman, Stanley

    2005-01-01

    Mice infected with mouse hepatitis virus strain JHM develop an inflammatory demyelinating disease in the central nervous system with many similarities to human multiple sclerosis. The mouse disease is primarily immune-mediated because demyelination is not detected in JHM-infected mice lacking T or B cells but does occur after transfer of JHM-specific T cells. Although less is known about the ability of antibodies to mediate demyelination, the presence of oligoclonally expanded B cells and hig...

  1. Factors associated with persistence of red blood cell antibodies in woman after pregnancies complicated by fetal alloimmune haemolytic disease treated with intrauterine transfusions.

    Science.gov (United States)

    Verduin, Esther P; Brand, Anneke; van de Watering, Leo M G; Claas, Frans H J; Oepkes, Dick; Lopriore, Enrico; Doxiadis, Ilias I N; Schonewille, Henk

    2015-02-01

    Red blood cell (RBC) antibodies can persist for decades or decrease quickly to undetectable levels. Antibody persistence has not been systematically studied. Women whose children are treated with intrauterine transfusions (IUT) for haemolytic disease of the fetus (HDFN) often produce additional antibodies, which can be evoked by the intrauterine transfusion or by fetomaternal haemorrhage during the procedure. Factors associated with persistence of both the antibodies responsible for HDFN and additional antibodies were studied in 260 women whose children were treated with IUT between 1988 and 2008. They possessed 499 (205 anti-D and 294 non-D) antibodies after the last IUT. After a median follow-up of 8·7 years, all 260 antibodies primarily responsible for HDFN had persisted. Additional antibodies directed against antigens of the children persisted in 70·6%, and in 32·3% if they were not child-specific (P < 0·001). Antibodies induced by irradiated IUT persisted in only 7·1%. Multivariate analyses showed that non-HDFN antibody persistence was dependent on the antibody titre and specificity. In conclusion, persistence of antibodies mainly depends on antibody strength and specificity. Difference between fetal or non-fetal immunogens suggests maintenance of antigenic stimulation possibly by long-term fetomaternal chimerism. PMID:25244566

  2. Antibody-free isolation of rare cancer cells from blood based on 3D lateral dielectrophoresis.

    Science.gov (United States)

    Cheng, I-Fang; Huang, Wei-Lun; Chen, Tzu-Ying; Liu, Chien-Wei; Lin, Yu-De; Su, Wu-Chou

    2015-07-21

    We present an antibody-free approach for the high-purity and high-throughput dielectrophoretic (DEP) isolation of circulating tumour cells (CTCs) from blood in a microfluidic chip. A hydrodynamic sheath flow is designed upstream in the chip to direct the suspension samples to the channel side walls, thus providing a queue to allow DEP-induced lateral displacements. High-throughput continuous cancer cell sorting (maximum flow rate: ~2.4 mL h(-1), linear velocity: ~4 mm s(-1)) is achieved with a sustained 3D lateral DEP (LDEP) particle force normal to the continuous through-flow. This design allows the continuous fractionation of micro/nanosized particles into different downstream subchannels based on the differences in their different critical negative DEP strengths/mobilities. The main advantage of this separation strategy is that increasing the channel length can effectively increase the throughput proportionally. The effective separation of rare cancer cells (<0.001%) from diluted human blood in a handheld chip is demonstrated. An enrichment factor of 10(5) and a recovery rate of ~85% from a 0.001% cancer cell sample are achieved at an optimal flow rate of 20 μL min(-1) passing through a 6 cm long LDEP channel with an appropriate voltage at a frequency of 10 kHz. A higher throughput of 2.4 mL h(-1) is also achieved with a 13 cm long metal-based microchannel. PMID:26085231

  3. Kinetics of antibody-induced modulation of respiratory syncytial virus antigens in a human epithelial cell line

    Directory of Open Access Journals (Sweden)

    Gómez-Garcia Beatriz

    2007-07-01

    Full Text Available Abstract Background The binding of viral-specific antibodies to cell-surface antigens usually results in down modulation of the antigen through redistribution of antigens into patches that subsequently may be internalized by endocytosis or may form caps that can be expelled to the extracellular space. Here, by use of confocal-laser-scanning microscopy we investigated the kinetics of the modulation of respiratory syncytial virus (RSV antigen by RSV-specific IgG. RSV-infected human epithelial cells (HEp-2 were incubated with anti-RSV polyclonal IgG and, at various incubation times, the RSV-cell-surface-antigen-antibody complexes (RSV Ag-Abs and intracellular viral proteins were detected by indirect immunoflourescence. Results Interaction of anti-RSV polyclonal IgG with RSV HEp-2 infected cells induced relocalization and aggregation of viral glycoproteins in the plasma membrane formed patches that subsequently produced caps or were internalized through clathrin-mediated endocytosis participation. Moreover, the concentration of cell surface RSV Ag-Abs and intracellular viral proteins showed a time dependent cyclic variation and that anti-RSV IgG protected HEp-2 cells from viral-induced death. Conclusion The results from this study indicate that interaction between RSV cell surface proteins and specific viral antibodies alter the expression of viral antigens expressed on the cells surface and intracellular viral proteins; furthermore, interfere with viral induced destruction of the cell.

  4. Tumor cell-selective apoptosis induction through targeting of KV10.1 via bifunctional TRAIL antibody

    Directory of Open Access Journals (Sweden)

    Pardo Luis A

    2011-09-01

    Full Text Available Abstract Background The search for strategies to target ion channels for therapeutic applications has become of increasing interest. Especially, the potassium channel KV10.1 (Ether-á-go-go is attractive as target since this surface protein is virtually not detected in normal tissue outside the central nervous system, but is expressed in approximately 70% of tumors from different origins. Methods We designed a single-chain antibody against an extracellular region of KV10.1 (scFv62 and fused it to the human soluble TRAIL. The KV10.1-specific scFv62 antibody -TRAIL fusion protein was expressed in CHO-K1 cells, purified by chromatography and tested for biological activity. Results Prostate cancer cells, either positive or negative for KV10.1 were treated with the purified construct. After sensitization with cytotoxic drugs, scFv62-TRAIL induced apoptosis only in KV10.1-positive cancer cells, but not in non-tumor cells, nor in tumor cells lacking KV10.1 expression. In co-cultures with KV10.1-positive cancer cells the fusion protein also induced apoptosis in bystander KV10.1-negative cancer cells, while normal prostate epithelial cells were not affected when present as bystander. Conclusions KV10.1 represents a novel therapeutic target for cancer. We could design a strategy that selectively kills tumor cells based on a KV10.1-specific antibody.

  5. 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. PMID:26905635

  6. Induction of antigen-specific antibody response in human pheripheral blood lymphocytes in vitro by a dog kidney cell vaccine against rabies virus (DKCV).

    OpenAIRE

    Uytdehaag, Fons; Osterhaus, Ab; Loggen, H.G.; Bakker, Roland; Van Asten, Jack; Kreeftenberg, J.G.; Marel, P.; Steenis, Bert

    1983-01-01

    textabstractIn the present report an in vitro method for obtaining a secondary human antibody response to a dog kidney cell vaccine against rabies virus (DKCV) is described. Cultures of peripheral blood mononuclear cells from normal rabies-immune and nonimmune donors were stimulated in vitro by DKCV. The production of virus-specific antibody in supernatant fluids was monitored by ELISA. Antibody was produced by lymphocytes from rabies-immune individuals, whereas those of nonimmune subjects co...

  7. Anti-NeuGcGM3 reactivity: a possible role of natural antibodies and B-1 cells in tumor immunosurveillance.

    Science.gov (United States)

    Rodriguez-Zhurbenko, Nely; Rabade-Chediak, Maura; Martinez, Darel; Griñan, Tania; Hernandez, Ana Maria

    2015-12-01

    While not naturally expressed in normal human tissues, N-glycolylated (NeuGc) gangliosides are overexpressed in several tumors and have immunosuppressive capacity, which contributes to cancer progression. Naturally occurring antibodies against NeuGcGM3 exist in healthy donors that specifically recognize and kill tumor cells expressing the antigen by complement-dependent and -independent mechanisms, the latter resembling an oncotic necrosis-type of cell death. Both the levels of anti-NeuGcGM3 antibodies in the sera of healthy donors and the percentage of donors with these natural antibodies decrease with age. Our work has shown that anti-NeuGcGM3 antibodies are not detected in the sera of non-small cell lung cancer (NSCLC) patients, compared to age- and sex-matched healthy donors, which have anti-NeuGcGM3. Interestingly, the level of serum total IgM, but not IgG, was significantly lower in cancer patients than in healthy donors. Screening of immortalized mouse splenic and peritoneal-derived hybridomas showed that peritoneal B-1 cells secrete anti-NeuGcGM3 with tumor cytotoxic capacity. Defects in the natural surveillance against tumor antigens could increase the risk of elderly donors developing cancer and affect the capacity of cancer patients to effectively fight against tumor cells. PMID:26214505

  8. EB66 cell line, a duck embryonic stem cell-derived substrate for the industrial production of therapeutic monoclonal antibodies with enhanced ADCC activity

    OpenAIRE

    Olivier, Stéphane; Jacoby, Marine; Brillon, Cédric; Bouletreau, Sylvana; Mollet, Thomas; Nerriere, Olivier; Angel, Audrey; Danet, Sévérine; Souttou, Boussad; Guehenneux, Fabienne; Gauthier, Laurent; Berthomé, Mathilde; Vié, Henri; Beltraminelli, Nicola; Mehtali, Majid

    2010-01-01

    Monoclonal antibodies (mAbs) represent the fastest growing class of therapeutic proteins. The increasing demand for mAb manufacturing and the associated high production costs call for the pharmaceutical industry to improve its current production processes or develop more efficient alternative production platforms. The experimental control of IgG fucosylation to enhance antibody dependent cell cytotoxicity (ADCC) activity constitutes one of the promising strategies to improve the efficacy of m...

  9. Approach to a case of multiple irregular red cell antibodies in a liver transplant recipient: Need for developing competence

    Directory of Open Access Journals (Sweden)

    Ravi C Dara

    2015-01-01

    Full Text Available Liver transplant procedure acts as a challenge for transfusion services in terms of specialized blood components, serologic problems, and immunologic effects of transfusion. Red cell alloimmunization in patients awaiting a liver transplant complicate the process by undue delay or unavailability of compatible red blood cell units. Compatible blood units can be provided by well-equipped immunohematology laboratory, which has expertise in resolving these serological problems. This report illustrates resolution of a case with multiple alloantibodies using standard techniques, particularly rare antisera. Our case re-emphasizes the need for universal antibody screening in all patients as part of pretransfusion testing, which helps to identify atypical antibodies and plan for appropriate transfusion support well in time. We recommend that the centers, especially the ones that perform complex procedures like solid organ transplants and hematological transplants should have the necessary immunohematological reagents including rare antisera to resolve complex cases of multiple antibodies as illustrated in this case.

  10. Intracellular distribution of TM4SF1 and internalization of TM4SF1-antibody complex in vascular endothelial cells

    International Nuclear Information System (INIS)

    Transmembrane-4 L-six family member-1 (TM4SF1) is a small plasma membrane-associated glycoprotein that is highly and selectively expressed on the plasma membranes of tumor cells, cultured endothelial cells, and, in vivo, on tumor-associated endothelium. Immunofluorescence microscopy also demonstrated TM4SF1 in cytoplasm and, tentatively, within nuclei. With monoclonal antibody 8G4, and the finer resolution afforded by immuno-nanogold transmission electron microscopy, we now demonstrate TM4SF1 in uncoated cytoplasmic vesicles, nuclear pores and nucleoplasm. Because of its prominent surface location on tumor cells and tumor-associated endothelium, TM4SF1 has potential as a dual therapeutic target using an antibody drug conjugate (ADC) approach. For ADC to be successful, antibodies reacting with cell surface antigens must be internalized for delivery of associated toxins to intracellular targets. We now report that 8G4 is efficiently taken up into cultured endothelial cells by uncoated vesicles in a dynamin-dependent, clathrin-independent manner. It is then transported along microtubules through the cytoplasm and passes through nuclear pores into the nucleus. These findings validate TM4SF1 as an attractive candidate for cancer therapy with antibody-bound toxins that have the capacity to react with either cytoplasmic or nuclear targets in tumor cells or tumor-associated vascular endothelium. - Highlights: • Anti-TM4SF1 antibody 8G4 was efficiently taken up by cultured endothelial cells. • TM4SF1–8G4 internalization is dynamin-dependent but clathrin-independent. • TM4SF1–8G4 complexes internalize along microtubules to reach the perinuclear region. • Internalized TM4SF1–8G4 complexes pass through nuclear pores into the nucleus. • TM4SF1 is an attractive candidate for ADC cancer therapy

  11. Intracellular distribution of TM4SF1 and internalization of TM4SF1-antibody complex in vascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Sciuto, Tracey E.; Merley, Anne; Lin, Chi-Iou [Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School (United States); Richardson, Douglas [Department of Molecular and Cellular Biology, Harvard University (United States); Liu, Yu [Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Shanxi Province, Taiyuan 030001 (China); Li, Dan; Dvorak, Ann M. [Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School (United States); Dvorak, Harold F., E-mail: hdvorak@bidmc.harvard.edu [Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School (United States); Jaminet, Shou-Ching S., E-mail: sjaminet@bidmc.harvard.edu [Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School (United States)

    2015-09-25

    Transmembrane-4 L-six family member-1 (TM4SF1) is a small plasma membrane-associated glycoprotein that is highly and selectively expressed on the plasma membranes of tumor cells, cultured endothelial cells, and, in vivo, on tumor-associated endothelium. Immunofluorescence microscopy also demonstrated TM4SF1 in cytoplasm and, tentatively, within nuclei. With monoclonal antibody 8G4, and the finer resolution afforded by immuno-nanogold transmission electron microscopy, we now demonstrate TM4SF1 in uncoated cytoplasmic vesicles, nuclear pores and nucleoplasm. Because of its prominent surface location on tumor cells and tumor-associated endothelium, TM4SF1 has potential as a dual therapeutic target using an antibody drug conjugate (ADC) approach. For ADC to be successful, antibodies reacting with cell surface antigens must be internalized for delivery of associated toxins to intracellular targets. We now report that 8G4 is efficiently taken up into cultured endothelial cells by uncoated vesicles in a dynamin-dependent, clathrin-independent manner. It is then transported along microtubules through the cytoplasm and passes through nuclear pores into the nucleus. These findings validate TM4SF1 as an attractive candidate for cancer therapy with antibody-bound toxins that have the capacity to react with either cytoplasmic or nuclear targets in tumor cells or tumor-associated vascular endothelium. - Highlights: • Anti-TM4SF1 antibody 8G4 was efficiently taken up by cultured endothelial cells. • TM4SF1–8G4 internalization is dynamin-dependent but clathrin-independent. • TM4SF1–8G4 complexes internalize along microtubules to reach the perinuclear region. • Internalized TM4SF1–8G4 complexes pass through nuclear pores into the nucleus. • TM4SF1 is an attractive candidate for ADC cancer therapy.

  12. Synthesis and pre-clinical evaluation of an (18)F-labeled single-chain antibody fragment for PET imaging of epithelial ovarian cancer.

    Science.gov (United States)

    Sharma, Sai Kiran; Wuest, Melinda; Way, Jenilee D; Bouvet, Vincent R; Wang, Monica; Wuest, Frank R

    2016-01-01

    Anti-CA125 antibodies have been used in immunoassays to quantify levels of shed antigen in the serum of patients who are under surveillance for epithelial ovarian cancer (EOC). However, there is currently no molecular imaging probe in the clinic for the assessment of CA125 expression in vivo. The present study describes the development of an (18)F-labeled single-chain variable fragment (scFv) for PET imaging of CA125 in preclinical EOC models. Anti-CA125 scFv was derived from MAb-B43.13 by recombinant expression of the fragment in E.coli. Fragment scFv-B43.13 was purified via immobilized metal affinity chromatography and characterized for antigen binding via immuno-staining and flow cytometry. Prosthetic group N-succinimidyl 4-[(18)F]fluorobenzoate ([(18)F]SFB) was used for radiolabeling of scFv-B43.13. Preclinical ovarian cancer models were developed based on ovarian cancer cell lines OVCAR3 (CA125-positive) and SKOV3 (CA125-negative) in NIH-III mice. The radiopharmacological profile of (18)F-labeled scFv-B43.13 ([(18)F]FBz-scFv-B43.13) was studied with PET. [(18)F]FBz-scFv-B43.13 was prepared in radiochemical yields of 3.7 ± 1.8% (n = 5) at an effective specific activity of 3.88 ± 0.76 GBq/µmol (n = 5). The radiotracer demonstrated selective uptake in CA125-positive OVCAR3 cells and virtually no uptake in CA125-negative SKOV3 cells. Standardized uptake values (SUV) of radioactivity uptake in OVCAR3 tumors was 0.5 (n = 3) and 0.3 (n = 2) in SKOV3 tumors after 60 min post injection (p.i.). PMID:27508105

  13. Synthesis and pre-clinical evaluation of an 18F-labeled single-chain antibody fragment for PET imaging of epithelial ovarian cancer

    Science.gov (United States)

    Sharma, Sai Kiran; Wuest, Melinda; Way, Jenilee D; Bouvet, Vincent R; Wang, Monica; Wuest, Frank R

    2016-01-01

    Anti-CA125 antibodies have been used in immunoassays to quantify levels of shed antigen in the serum of patients who are under surveillance for epithelial ovarian cancer (EOC). However, there is currently no molecular imaging probe in the clinic for the assessment of CA125 expression in vivo. The present study describes the development of an 18F-labeled single-chain variable fragment (scFv) for PET imaging of CA125 in preclinical EOC models. Anti-CA125 scFv was derived from MAb-B43.13 by recombinant expression of the fragment in E.coli. Fragment scFv-B43.13 was purified via immobilized metal affinity chromatography and characterized for antigen binding via immuno-staining and flow cytometry. Prosthetic group N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) was used for radiolabeling of scFv-B43.13. Preclinical ovarian cancer models were developed based on ovarian cancer cell lines OVCAR3 (CA125-positive) and SKOV3 (CA125-negative) in NIH-III mice. The radiopharmacological profile of 18F-labeled scFv-B43.13 ([18F]FBz-scFv-B43.13) was studied with PET. [18F]FBz-scFv-B43.13 was prepared in radiochemical yields of 3.7 ± 1.8% (n = 5) at an effective specific activity of 3.88 ± 0.76 GBq/µmol (n = 5). The radiotracer demonstrated selective uptake in CA125-positive OVCAR3 cells and virtually no uptake in CA125-negative SKOV3 cells. Standardized uptake values (SUV) of radioactivity uptake in OVCAR3 tumors was 0.5 (n = 3) and 0.3 (n = 2) in SKOV3 tumors after 60 min post injection (p.i.). PMID:27508105

  14. Cell proliferation-associated nuclear antigen defined by antibody Ki-67: a new kind of cell cycle-maintaining proteins

    International Nuclear Information System (INIS)

    A decade of studies on the human nuclear antigen defined by monoclonal antibody Ki-67 (the 'Ki-67 proteins') has made it abundantly clear that this structure is strictly associated with human cell proliferation and the expression of this protein can be used to access the growth fraction of a given cell population. Until recently the Ki-67 protein was described as a nonhistone protein that is highly susceptible to protease treatment. We have isolated and sequenced cDNAs encoding for this antigen and found two isoforms of the full length cDNA of 11.5 and 12.5 kb, respectively, sequence and structure of which are thus far unique. The gene encoding the Ki-67 protein is organized in 15 exons and is localized on chromosome 10. The center of this gene is formed by an extraordinary 6845 bp exon containing 16 successively repeated homologous segments of 366 bp ('Ki-67 repeats'), each containing a highly conserved new motif of 66 bp ('Ki-67 motif'). The deduced peptide sequence of this central exon possesses 10 ProGluSerThr (PEST) motifs which are associated with high turnover proteins such as other cell cycle-related proteins, oncogenes and transcription factors, etc. Like the latter proteins the Ki-67 antigen plays a pivotal role in maintaining cell proliferation because Ki-67 protein antisense oligonucleotides significantly inhibit 3H-thymidine incorporation in permanent human tumor cell lines in a dose-dependent manner. (author). 30 refs, 2 figs

  15. Prospective isolation of mesenchymal stem cells from human bone marrow using novel antibodies directed against Sushi domain containing 2.

    Science.gov (United States)

    Sivasubramaniyan, Kavitha; Harichandan, Abhishek; Schumann, Susanne; Sobiesiak, Malgorzata; Lengerke, Claudia; Maurer, Andreas; Kalbacher, Hubert; Bühring, Hans-Jörg

    2013-07-01

    Several strategies have been developed to facilitate the prospective isolation of bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs) based on the selective expression or absence of surface markers. Recently, we described the monoclonal antibodies W3D5 and W5C5, which selectively react with BM-MSCs, but not with hematopoietic cells. Both antibodies showed an identical reactivity pattern, indicating that they may recognize the same molecule. To identify the cognate antigen, cultured MSCs were sorted for cells expressing either very high levels of W5C5/W3D5 antigen or for cells which were negative for this antigen. Further processing of these cells for microarray analysis revealed a 20-fold enrichment of the type 1 integral membrane protein Sushi domain containing 2 (SUSD2) in the in W5C5(+) subset. To confirm the identity of the W5C5/W3D5 antigen to SUSD2, HEK293 cells were transfected with the full-length coding sequence of human SUSD2 followed by reactivity analysis of W5C5 and W3D5 antibodies with the transfected line. Flow cytometric analysis showed that both antibodies selectively recognized HEK293/huSUSD2 cells, but not the parental cell line. In line with this, SUSD2 siRNA treatment of SUSD2(+) WERI-RB-1 retinoblastoma cells reduced the expression levels of W3D5 and W5C5 antigens to ~39% and 37%, respectively. Finally, FACSorting and colony assays revealed that only SUSD2(+), but not SUSD2(-) BM cells give rise to colony-forming units-fibroblasts and are able to differentiate into osteoblasts, adipocytes, and chondrocytes. In conclusion, we identified SUSD2 as a novel and specific marker for the prospective isolation of BM-MSCs. PMID:23406305

  16. Inositol trisphosphate is generated by a rat natural killer cell tumor in response to target cells or to crosslinked monoclonal antibody OX-34: possible signaling role for the OX-34 determinant during activation by target cells.

    OpenAIRE

    Seaman, W E; Eriksson, E; Dobrow, R; Imboden, J B

    1987-01-01

    RNK-16 cells, rat leukemia cells with features of natural killer (NK) cells, were adapted for growth in vitro and used to examine the mechanism of NK-cell activation. Contact of RNK-16 cells with tumor cells (YAC-1) that are lysed by NK cells, but not with resistant tumor cells (EL-4, K562), led to an increase in inositol trisphosphate (InsP3), a Ca2+-mobilizing messenger. A similar increase in InsP3 could be elicited in RNK-16 cells by monoclonal antibody OX-34, when the antibody was crossli...

  17. Control of Toll-like receptor-mediated T cell-independent type 1 antibody responses by the inducible nuclear protein IκB-ζ.

    Science.gov (United States)

    Hanihara-Tatsuzawa, Fumito; Miura, Hanae; Kobayashi, Shuhei; Isagawa, Takayuki; Okuma, Atsushi; Manabe, Ichiro; MaruYama, Takashi

    2014-11-01

    Antibody responses have been classified as being either T cell-dependent or T cell-independent (TI). TI antibody responses are further classified as being either type 1 (TI-1) or type 2 (TI-2), depending on their requirement for B cell-mediated antigen receptor signaling. Although the mechanistic basis of antibody responses has been studied extensively, it remains unclear whether different antibody responses share similarities in their transcriptional regulation. Here, we show that mice deficient in IκB-ζ, specifically in their B cells, have impaired TI-1 antibody responses but normal T cell-dependent and TI-2 antibody responses. The absence of IκB-ζ in B cells also impaired proliferation triggered by Toll-like receptor (TLR) activation, plasma cell differentiation, and class switch recombination (CSR). Mechanistically, IκB-ζ-deficient B cells could not induce TLR-mediated induction of activation-induced cytidine deaminase (AID), a class-switch DNA recombinase. Retroviral transduction of AID in IκB-ζ-deficient B cells restored CSR activity. Furthermore, acetylation of histone H3 in the vicinity of the transcription start site of the gene that encodes AID was reduced in IκB-ζ-deficient B cells relative to IκB-ζ-expressing B cells. These results indicate that IκB-ζ regulates TLR-mediated CSR by inducing AID. Moreover, IκB-ζ defines differences in the transcriptional regulation of different antibody responses. PMID:25124037

  18. Rapid assessment of antibody-induced ricin neutralization by employing a novel functional cell-based assay.

    Science.gov (United States)

    Gal, Yoav; Alcalay, Ron; Sabo, Tamar; Noy-Porat, Tal; Epstein, Eyal; Kronman, Chanoch; Mazor, Ohad

    2015-09-01

    Ricin is one of the most potent and lethal toxins known against which there is no available antidote. Currently, the most promising countermeasures against the toxin are based on neutralizing antibodies elicited by active vaccination or administered passively. A cell-based assay is widely applied for the primary screening and evaluation of anti-ricin antibodies, yet such assays are usually time-consuming (18-72 h). Here, we report of a novel assay to monitor ricin activity, based on HeLa cells that stably express the rapidly-degraded ubiquitin-luciferase (Ub-FL, half-life of 2 min). Ricin-induced arrest of protein synthesis could be quantified within 3 to 6h post intoxication (IC90 of 300 and 100 ng/ml, respectively). Furthermore, by stabilizing the intracellular levels of Ub-FL in the last hour of the assay, a 3-fold increase in the assay sensitivity was attained. We applied this assay to monitor the efficacy of a ricin holotoxin-based vaccine by measuring the formation of neutralizing antibodies throughout the immunization course. The potency of anti-ricin monoclonal antibodies (directed to either subunit of the toxin) could also be easily and accurately measured in this assay format. Owing to its simplicity, this assay may be implemented for high-throughput screening of ricin-neutralizing antibodies and for identification of small-molecule inhibitors of the toxin, as well as other ribosome-inactivating toxins. PMID:26003675

  19. Antibody-Dependent Cell-Mediated Cytotoxicity to Hemagglutinin of Influenza A Viruses After Influenza Vaccination in Humans

    Science.gov (United States)

    Zhong, Weimin; Liu, Feng; Wilson, Jason R.; Holiday, Crystal; Li, Zhu-Nan; Bai, Yaohui; Tzeng, Wen-Pin; Stevens, James; York, Ian A.; Levine, Min Z.

    2016-01-01

    Background. Detection of neutralizing antibodies (nAbs) to influenza A virus hemagglutinin (HA) antigens by conventional serological assays is currently the main immune correlate of protection for influenza vaccines However, current prepandemic avian influenza vaccines are poorly immunogenic in inducing nAbs despite considerable protection conferred. Recent studies show that Ab-dependent cell-mediated cytotoxicity (ADCC) to HA antigens are readily detectable in the sera of healthy individuals and patients with influenza infection. Methods. Virus neutralization and ADCC activities of serum samples from individuals who received either seasonal or a stock-piled H5N1 avian influenza vaccine were evaluated by hemagglutination inhibition assay, microneutralization assay, and an improved ADCC natural killer (NK) cell activation assay. Results. Immunization with inactivated seasonal influenza vaccine led to strong expansion of both nAbs and ADCC-mediating antibodies (adccAbs) to H3 antigen of the vaccine virus in 24 postvaccination human sera. In sharp contrast, 18 individuals vaccinated with the adjuvanted H5N1 avian influenza vaccine mounted H5-specific antibodies with strong ADCC activities despite moderate virus neutralization capacity. Strength of HA-specific ADCC activities is largely associated with the titers of HA-binding antibodies and not with the fine antigenic specificity of anti-HA nAbs. Conclusions. Detection of both nAbs and adccAbs may better reflect protective capacity of HA-specific antibodies induced by avian influenza vaccines.

  20. The future of CD20 monoclonal antibody therapy in B-cell malignancies.

    Science.gov (United States)

    Czuczman, Myron S; Gregory, Stephanie A

    2010-06-01

    Limitations of therapeutic options for chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL) have necessitated the development of novel treatments/strategies. Rituximab (chimeric anti-CD20 monoclonal antibody [mAb]) considerably improved therapeutic outcomes for patients with B-cell malignancies, particularly when combined with chemotherapy; outcomes, however, are limited by rituximab resistance or reduced response upon re-treatment. Novel anti-CD20 mAbs are in development that may enhance mAb therapy. Ofatumumab (human anti-CD20 mAb) induces highly potent cell lysis, including in cells with low CD20 expression, and is the most clinically advanced new anti-CD20 mAb. Positive phase III interim data for ofatumumab in fludarabine-refractory CLL that is also refractory to alemtuzumab or less suitable for alemtuzumab due to bulky (>5 cm) lymphadenopathy has led to FDA approval of this agent in this population. Preclinical and early clinical assessment of other novel anti-CD20 mAbs include: ocrelizumab, veltuzumab, GA101, AME-133v, and PRO131921; data suggest potential for improved efficacy over rituximab that will require substantiation in large-scale clinical trials. New treatment strategies and novel anti-CD20 mAbs have the potential to enhance long-term outcomes for CLL and NHL. PMID:20367564

  1. Mammalian Cell Culture Process for Monoclonal Antibody Production: Nonlinear Modelling and Parameter Estimation

    Directory of Open Access Journals (Sweden)

    Dan Selişteanu

    2015-01-01

    Full Text Available Monoclonal antibodies (mAbs are at present one of the fastest growing products of pharmaceutical industry, with widespread applications in biochemistry, biology, and medicine. The operation of mAbs production processes is predominantly based on empirical knowledge, the improvements being achieved by using trial-and-error experiments and precedent practices. The nonlinearity of these processes and the absence of suitable instrumentation require an enhanced modelling effort and modern kinetic parameter estimation strategies. The present work is dedicated to nonlinear dynamic modelling and parameter estimation for a mammalian cell culture process used for mAb production. By using a dynamical model of such kind of processes, an optimization-based technique for estimation of kinetic parameters in the model of mammalian cell culture process is developed. The estimation is achieved as a result of minimizing an error function by a particle swarm optimization (PSO algorithm. The proposed estimation approach is analyzed in this work by using a particular model of mammalian cell culture, as a case study, but is generic for this class of bioprocesses. The presented case study shows that the proposed parameter estimation technique provides a more accurate simulation of the experimentally observed process behaviour than reported in previous studies.

  2. Mammalian cell culture process for monoclonal antibody production: nonlinear modelling and parameter estimation.

    Science.gov (United States)

    Selişteanu, Dan; Șendrescu, Dorin; Georgeanu, Vlad; Roman, Monica

    2015-01-01

    Monoclonal antibodies (mAbs) are at present one of the fastest growing products of pharmaceutical industry, with widespread applications in biochemistry, biology, and medicine. The operation of mAbs production processes is predominantly based on empirical knowledge, the improvements being achieved by using trial-and-error experiments and precedent practices. The nonlinearity of these processes and the absence of suitable instrumentation require an enhanced modelling effort and modern kinetic parameter estimation strategies. The present work is dedicated to nonlinear dynamic modelling and parameter estimation for a mammalian cell culture process used for mAb production. By using a dynamical model of such kind of processes, an optimization-based technique for estimation of kinetic parameters in the model of mammalian cell culture process is developed. The estimation is achieved as a result of minimizing an error function by a particle swarm optimization (PSO) algorithm. The proposed estimation approach is analyzed in this work by using a particular model of mammalian cell culture, as a case study, but is generic for this class of bioprocesses. The presented case study shows that the proposed parameter estimation technique provides a more accurate simulation of the experimentally observed process behaviour than reported in previous studies. PMID:25685797

  3. Detection of Staphylococci aureus cells with single domain antibody functionalized Raman nanoparobes

    Science.gov (United States)

    Tay, Li-Lin; Tanha, Jamshid; Ryan, Shannon; Veres, Teodor

    2007-06-01

    Raman spectroscopy has demonstrated to be an effective tool in the detection and classification of pathogenic microorganisms. The technique is, however, limited by the inherently low cross-section of the Raman scattering process. Among the many enhanced Raman processes, surface enhanced Raman scattering (SERS) technique provides the highest sensitivity and can be easily adapted in the bio-sensing applications such as DNA hybridization and protein binding events. In this study, we report the targeted detection of the pathogenic bacteria, Staphylococcus aureus, with novel single domain antibody (sdAb) conjugated SERS nanoprobes. A sdAb specific to protein A of S. aureus cells was conjugated to silver nanoparticles (Ag-NP). Bacteria recognition was achieved through specific binding of the sdAb (conjugated to SERS nanoprobe) to protein A. Binding rendered the nanoparticle-labeled S. aureus cells SERS active. As a result, S. aureus cells could be detected rapidly and with excellent sensitivity by monitoring the SERS vibrational signatures. This work demonstrates that the SERS imaging technique offers excellent sensitivity with a detection limit of a single bacterium.

  4. Study of the diagnosis and treatment of renal cell carcinoma using monoclonal antibodies

    International Nuclear Information System (INIS)

    Among the potential applications of monoclonal antibodies (Mabs) in the diagnosis and treatment of human cancer is the use in the specific detection of cancer sites and the selective destruction of cancer cells. Fetal kidney was used as an immunogen to develop Mab A6H, which is highly reactive to 16/16 renal cell carcinoma (RCC) cell lines and to 16/19 human RCC specimens. RCC xenografts as small as 40 mg have been imaged clearly in radioimmunoscintigraphy studies using A6H labeled with iodine-131. In Mab-targeted radiotherapy studies, 2 doses of 100-150 uCi 131I-labeled A6H or an 131 I-labeled A6H-C5H cocktail caused tumor regression or tumor growth arrest in >80% of treated mice, while no such effect was observed in mice treated with 131I-labeled control Mab or unlabeled A6H. Internal radiation dosimetry, which was calculated by computer analysis of sequential radioimmunoscintigraphy, showed that A6H delivered approximately 35 rad/uCi of the injected dose to RCC xenografts. When the radiation dose to the tumor was 3000 rad resulted in tumor regression or growth arrest in >85% of mice. A clinical trial using 131I-labeled A6H in the diagnosis and treatment of RCC is now underway at our institution

  5. Peptidoglycan-linked protein A promotes T cell-dependent antibody expansion during Staphylococcus aureus infection.

    Science.gov (United States)

    Kim, Hwan Keun; Falugi, Fabiana; Missiakas, Dominique M; Schneewind, Olaf

    2016-05-17

    A hallmark of Staphylococcus aureus disease in humans is persistent infections without development of protective immune responses. Infected patients generate VH3 plasmablast expansions and increased VH3 idiotype Ig; however, the mechanisms for staphylococcal modification of immune responses are not known. We report here that S. aureus-infected mice generate VH3 antibody expansions via a mechanism requiring MHC-restricted antigen presentation to CD4(+) T cells and staphylococcal protein A (SpA), a cell wall-anchored surface molecule that binds Fcγ and VH3 variant heavy chains of Ig. VH3 expansion occurred with peptidoglycan-linked SpA from the bacterial envelope but not with recombinant SpA, and optimally required five tandem repeats of its Ig-binding domains. Signaling via receptor-interacting serine/threonine protein kinase 2 (RIPK2) was essential for implementing peptidoglycan-linked SpA superantigen activity. VH3 clan IgG from S. aureus-infected or SpA-treated animals was not pathogen-specific, suggesting that SpA cross-linking of VH3 idiotype B-cell receptors and activation via attached peptidoglycan are the determinants of staphylococcal escape from adaptive immune responses. PMID:27140614

  6. Long-term Continuous Production of Monoclonal Antibody by Hybridoma Cells Immobilized in a Fibrous-Bed Bioreactor

    OpenAIRE

    Zhu, Hui; Yang, Shang-Tian

    2004-01-01

    The kinetics and long-term stability of continuous production of monoclonal antibody IgG2b by hybridoma HD-24 cells immobilized in a fibrous-bed bioreactor (FBB) were studied for a period of ∼8 months. The cells were immobilized in the fibrous bed by surface attachment of cells and entrapment of large cell clumps in the void space of the fibrous matrix. A high viable cell density of 1.01 × 108/ml was attained in the bioreactor, which was about 63 times higher than those in conventional T-flas...

  7. Effects of anti-vascular endothelial growth factor monoclonal antibody (bevacizumab on lens epithelial cells

    Directory of Open Access Journals (Sweden)

    Jun JH

    2016-06-01

    Full Text Available Jong Hwa Jun,1 Wern-Joo Sohn,2 Youngkyun Lee,2 Jae-Young Kim21Department of Ophthalmology, School of Medicine, Dongsan Medical Center, Keimyung University, 2Department of Oral Biochemistry, School of Dentistry, IHBR, Kyungpook National University, Daegu, South KoreaAbstract: The molecular and cellular effects of anti-vascular endothelial growth factor monoclonal antibody (bevacizumab on lens epithelial cells (LECs were examined using both an immortalized human lens epithelial cell line and a porcine capsular bag model. After treatment with various concentrations of bevacizumab, cell viability and proliferation patterns were evaluated using the water-soluble tetrazolium salt assay and 5-bromo-2'-deoxyuridine enzyme-linked immunosorbent assay, respectively. The scratch assay and Western blot analysis were employed to validate the cell migration pattern and altered expression levels of signaling molecules related to the epithelial–mesenchymal transition (EMT. Application of bevacizumab induced a range of altered cellular events in a concentration-dependent manner. A 0.1–2 mg/mL concentration demonstrated dose-dependent increase in proliferation and viability of LECs. However, 4 mg/mL decreased cell proliferation and viability. Cell migrations displayed dose-dependent retardation from 0.1 mg/mL bevacizumab treatment. Transforming growth factor-β2 expression was markedly increased in a dose-dependent manner, and α-smooth muscle actin, matrix metalloproteinase-9, and vimentin expression levels showed dose-dependent changes in a B3 cell line. Microscopic observation of porcine capsular bag revealed changes in cellular morphology and a decline in cell density compared to the control after 2 mg/mL treatment. The central aspect of posterior capsule showed delayed confluence, and the factors related to EMT revealed similar expression patterns to those identified in the cell line. Based on these results, bevacizumab modulates the proliferation

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

    DEFF Research Database (Denmark)

    Klitgaard, Josephine L; Koefoed, Klaus; Geisler, Christian;

    2013-01-01

    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 ...

  9. A cell sorter with modified bamboo charcoal for the efficient selection of specific antibody-producing hybridomas.

    Science.gov (United States)

    Lin, Chien-Chen; Ni, Mei-Hui; Chang, Yu-Chung; Yeh, Hsiu-Lun; Lin, Feng-Huei

    2010-11-01

    Monoclonal antibodies (mAbs) have been proven useful in research and clinical applications. However, the generation of mAbs by conventional hybridoma technology is time-, cost- and labor-consuming. Here we developed a simplified procedure for efficient generation and selection of antibody-producing hybridomas within 1 h, using a particular cell sorter design, a cytoflow reactor-based cell sorter (CBCS) which consists mainly of the "cytoflow reactor" that comprises two components, a reaction chamber and a glass tubing for air and medium exchange by gravity, and the "sorting material", human EGFR-conjugated bamboo charcoal, for specific B-cell enrichment. The high surface area and porous structure of bamboo charcoal greatly increased cell density and protein production. Moreover, from Raman, FT-IR spectroscopy and IFA analysis, the carboxylation and immobilization of bamboo charcoal can be introduced easily by nitric acid treatment and conjugated handily with human EGFR using EDC/NHS. Other evidences, such as IFA, showed that the specific hybridomas generated in this study could secrete specific anti-human EGFR antibodies. Our design allows the production of mAbs while avoiding time-consuming steps, such as large numbers of limiting dilutions and screening assays, and demonstrates that the CBCS could be a powerful tool for monoclonal antibody production. PMID:20708791

  10. A partner monoclonal antibody to Moab 730 kills 100% of DU145 and PC3 androgen-independent cancer cells

    Indian Academy of Sciences (India)

    Hemant Kumar Vyas; Rahul Pal; Nirmal K Lohiya; G P Talwar

    2009-12-01

    A number of therapeutic options are available for patients with prostate carcinoma till the time that the tumour is hormone dependent. However, no fully effective therapy is available for the treatment of androgen-independent prostate carcinomas. Antibodies directed at epitopes unique to or overexpressed on the cancer cells could be of therapeutic utility. A monoclonal antibody (Moab) 2C4 has been generated, which binds with cells of two androgenindependent prostate cancers, DU145 and PC3, and does not bind to peripheral blood leukocytes (PBLs) of healthy donors. This antibody, along with the previously developed Moab 730, kills 100% of both DU145 and PC3 cells in the presence of complement and does not have a deleterious effect on PBLs of healthy males. The anti-tumour action of the two antibodies prevents the establishment of DU145 cell tumour in nude mice in vivo. Moab 2C4 in combination with 730 has potential for use as therapy for androgen-independent cancers.

  11. PHASE-I STUDY OF INTRAVENOUSLY APPLIED BISPECIFIC ANTIBODY IN RENAL-CELL CANCER-PATIENTS RECEIVING SUBCUTANEOUS INTERLEUKIN-2

    NARCIS (Netherlands)

    KROESEN, BJ; SLEIJFER, DT; JANSSEN, RAJ; VANDERGRAAF, WTA; THE, TH; DELEIJ, L; MULDER, NH

    1994-01-01

    In a phase I trial the toxicity and immunomodulatory effects of combined treatment with intravenous (i.v.) bispecific monoclonal antibody BIS-1 and subcutaneous (s.c.) interleukin 2 (IL-2) was studied in renal cell cancer patients. BIS-1 combines a specificity against CD3 on T lymphocytes with a spe

  12. Harnessing T cells to fight cancer with BiTE(®) antibody constructs - past developments and future directions.

    Science.gov (United States)

    Klinger, Matthias; Benjamin, Jonathan; Kischel, Roman; Stienen, Sabine; Zugmaier, Gerhard

    2016-03-01

    Bispecific T-cell engager (BiTE(®) ) antibody constructs represent a novel immunotherapy that bridges cytotoxic T cells to tumor cells, thereby inducing target cell-dependent polyclonal T-cell activation and proliferation, and leading to apoptosis of bound tumor cells. Anti-CD19 BiTE(®) blinatumomab has demonstrated clinical activity in Philadelphia chromosome (Ph)-negative relapsed or refractory (r/r) acute lymphoblastic leukemia (ALL) eventually resulting in conditional approval by the U.S. Food and Drug Administration in 2014. This drug is currently further developed in pediatric and Ph(+) r/r, as well as in minimal residual disease-positive ALL, and might also offer clinical benefit for patients with non-Hodgkin's lymphoma, especially for those with aggressive forms like diffuse large B-cell lymphoma. Another BiTE(®) antibody construct in hemato-oncology designated AMG 330 targets CD33 on acute myeloid leukemia blast cells. After showing promising ex vivo activity, this drug candidate has recently entered phase 1 clinical development, and has further indicated potential for combination with checkpoint inhibitors. In solid tumor indications, three BiTE(®) antibody constructs have been tested in phase 1 studies so far: anti-EpCAM BiTE(®) AMG 110, anti-CEA BiTE(®) MEDI-565/AMG 211, and anti-PSMA BiTE(®) BAY2010112/AMG 212. Pertinent questions comprise how to maximize BiTE(®) penetration and T-cell infiltration of the tumor while simultaneously minimizing any adverse events, which is currently explored by a continuous intravenous infusion approach. Thus, BiTE(®) antibody constructs will hopefully provide new treatment options for patients in several indications with high unmet medical need. PMID:26864113

  13. 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.

  14. Suppression of unprimed T and B cells in antibody responses by irradiation-resistant and plastic-adherent suppressor cells in Toxoplasma gondii-infected mice

    International Nuclear Information System (INIS)

    In the acute phase of Toxoplasma infection, the function of both helper T and B cells was suppressed in primary antibody responses to dinitrophenol (DNP)-conjugated protein antigens. During the course of infection, the suppressive effect on T cells seems to continue longer than that on B cells, since suppression in responses to sheep erythrocytes, a T-dependent antigen, persisted longer than those to DNP-Ficoll, a T-independent antigen. Plastic-adherent cells from the spleens of Toxoplasma-infected and X-irradiated (400 rads) mice had strong suppressor activity in primary anti-sheep erythrocyte antibody responses of normal mouse spleen cells in vitro. These data suggest that the activation of irradiation-resistant and plastic-adherent suppressor cells causes the suppression of both T and B cells in Toxoplasma-infected mice

  15. Intestinal commensal bacteria promote T cell hyporesponsiveness and down-regulate the serum antibody responses induced by dietary antigen.

    Science.gov (United States)

    Tsuda, Masato; Hosono, Akira; Yanagibashi, Tsutomu; Kihara-Fujioka, Miran; Hachimura, Satoshi; Itoh, Kikuji; Hirayama, Kazuhiro; Takahashi, Kyoko; Kaminogawa, Shuichi

    2010-08-16

    Colonization of the gut by commensal bacteria modulates the induction of oral tolerance and allergy. However, how these intestinal bacteria modulate antigen-specific T cell responses induced by oral antigens remains unclear. In order to investigate this, we used germ-free (GF) ovalbumin (OVA)-specific T cell receptor transgenic (OVA23-3) mice. Conventional (CV) or GF mice were administered an OVA-containing diet. Cytokine production by CD4(+) cells from spleen (SP), mesenteric lymph nodes (MLN) and Peyer's patches (PP) was evaluated by ELISA, as was the peripheral antibody titer. T cell phenotype was assessed by flow cytometry. CD4(+) cells from the SP and MLN of CV and GF mice fed an OVA diet for 3 weeks produced significantly less IL-2 than the corresponding cells from mice receiving a control diet, suggesting that oral tolerance could be induced at the T cell level in the systemic and intestinal immune systems of both bacterial condition of mice. However, we also observed that the T cell hyporesponsiveness induced by dietary antigen was delayed in the systemic immune tissues and was weaker in the intestinal immune tissues of the GF mice. Intestinal MLN and PP CD4(+) T cells from these animals also produced lower levels of IL-10, had less activated/memory type CD45RB(low) cells, and expressed lower levels of CTLA-4 but not Foxp3 compared to their CV counterparts. Furthermore, GF mice produced higher serum levels of OVA-specific antibodies than CV animals. CD40L expression by SP CD4(+) cells from GF mice fed OVA was higher than that of CV mice. These results suggest that intestinal commensal bacteria promote T cell hyporesponsiveness and down-regulate serum antibody responses induced by dietary antigens through modulation of the intestinal and systemic T cell phenotype. PMID:20621647

  16. Antibody and T-cell responses associated with experimental human malaria infection or vaccination show limited relationships.

    Science.gov (United States)

    Walker, Karen M; Okitsu, Shinji; Porter, David W; Duncan, Christopher; Amacker, Mario; Pluschke, Gerd; Cavanagh, David R; Hill, Adrian V S; Todryk, Stephen M

    2015-05-01

    This study examined specific antibody and T-cell responses associated with experimental malaria infection or malaria vaccination, in malaria-naive human volunteers within phase I/IIa vaccine trials, with a view to investigating inter-relationships between these types of response. Malaria infection was via five bites of Plasmodium falciparum-infected mosquitoes, with individuals reaching patent infection by 11-12 days, having harboured four or five blood-stage cycles before drug clearance. Infection elicited a robust antibody response against merozoite surface protein-119 , correlating with parasite load. Classical class switching was seen from an early IgM to an IgG1-dominant response of increasing affinity. Malaria-specific T-cell responses were detected in the form of interferon-γ and interleukin-4 (IL-4) ELIspot, but their magnitude did not correlate with the magnitude of antibody or its avidity, or with parasite load. Different individuals who were immunized with a virosome vaccine comprising influenza antigens combined with P. falciparum antigens, demonstrated pre-existing interferon-γ, IL-2 and IL-5 ELIspot responses against the influenza antigens, and showed boosting of anti-influenza T-cell responses only for IL-5. The large IgG1-dominated anti-parasite responses showed limited correlation with T-cell responses for magnitude or avidity, both parameters being only negatively correlated for IL-5 secretion versus anti-apical membrane antigen-1 antibody titres. Overall, these findings suggest that cognate T-cell responses across a range of magnitudes contribute towards driving potentially effective antibody responses in infection-induced and vaccine-induced immunity against malaria, and their existence during immunization is beneficial, but magnitudes are mostly not inter-related. PMID:25471322

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

    DEFF Research Database (Denmark)

    Schønning, Kristian; Lund, O; Lund, O S; Hansen, J E

    1999-01-01

    In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes are...... coexpressed. By the coexpression of Env glycoproteins that either can or cannot bind a neutralizing MAb in an env transcomplementation assay, virions were generated in which the proportion of MAb binding sites could be regulated. As the proportion of MAb binding sites in Env chimeric virus increased, MAb...

  18. Effect of using heat-inactivated serum with the Abbott human T-cell lymphotropic virus type III antibody test.

    OpenAIRE

    Jungkind, D. L.; DiRenzo, S A; Young, S J

    1986-01-01

    The Abbott enzyme immunoassay (Abbott Laboratories, North Chicago, Ill.) for human T-cell lymphotropic virus type III (HTLV-III) antibody was evaluated to determine the effect of using heat-inactivated (56 degrees C for 30 min) serum as the sample. Each of 58 nonreactive serum samples gave a higher A492 value when tested after heat inactivation. Ten of the samples became reactive after heating. Heat-inactivated serum should not be used in the current Abbott HTLV-III antibody test, because thi...

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

    OpenAIRE

    Roit, Fabio Da; Patrick J Engelberts; 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 ...

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

    DEFF Research Database (Denmark)

    Schønning, Kristian; Lund, O; Lund, O S; Hansen, J E

    1999-01-01

    In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes are...... data could not exclude the existence of a threshold for neutralization. However, results from MAb neutralization of chimeric virus containing wild-type Env and Env defective in CD4 binding was readily explained by a model of incremental MAb neutralization. In summary, the data indicate that MAb...

  1. Intracellular location of Bartonella henselae cocultivated with Vero cells and used for an indirect fluorescent-antibody test.

    OpenAIRE

    Zbinden, R.; Höchli, M; Nadal, D

    1995-01-01

    Bartonella henselae, the major causative agent of cat scratch disease, was cocultivated with Vero cells on chamber slides and visualized by indirect immunofluorescence by using a patient serum containing specific antibodies. Confocal microscopy localized the granular B. henselae-specific fluorescence mainly around the nuclei of Vero cells. By transmission electron microscopy, these granules were identified as clusters of multiple intracellular organisms. Fixed slides with the monolayers of Ve...

  2. Long-Lived Antibody and B Cell Memory Responses to the Human Malaria Parasites, Plasmodium falciparum and Plasmodium vivax

    OpenAIRE

    Wipasa, J; Suphavilai, C; Okell, LC; Cook, J; Corran, PH; Thaikla, K; Liewsaree, W; Riley, EM; Hafalla, JC

    2010-01-01

    Author Summary It is widely perceived that immunity to malaria is short-lived, rendering people susceptible to repeated malaria infections. However, there have been very few studies on “memory” responses, how the human immune system recognizes previously encountered malaria parasites. In particular, very little is known about the durability of malaria-specific B cells and antibodies. The aim of this study was to investigate the induction and maintenance of B cell memory responses to malaria p...

  3. Specifically modified Env immunogens activate B-cell precursors of broadly neutralizing HIV-1 antibodies in transgenic mice.

    Science.gov (United States)

    McGuire, Andrew T; Gray, Matthew D; Dosenovic, Pia; Gitlin, Alexander D; Freund, Natalia T; Petersen, John; Correnti, Colin; Johnsen, William; Kegel, Robert; Stuart, Andrew B; Glenn, Jolene; Seaman, Michael S; Schief, William R; Strong, Roland K; Nussenzweig, Michel C; Stamatatos, Leonidas

    2016-01-01

    VRC01-class broadly neutralizing HIV-1 antibodies protect animals from experimental infection and could contribute to an effective vaccine response. Their predicted germline forms (gl) bind Env inefficiently, which may explain why they are not elicited by HIV-1 Env-immunization. Here we show that an optimized Env immunogen can engage multiple glVRC01-class antibodies. Furthermore, this immunogen activates naive B cells expressing the human germline heavy chain of 3BNC60, paired with endogenous mouse light chains in vivo. To address whether it activates B cells expressing the fully humanized gl3BNC60 B-cell receptor (BCR), we immunized mice carrying both the heavy and light chains of gl3BNC60. B cells expressing this BCR display an autoreactive phenotype and fail to respond efficiently to soluble forms of the optimized immunogen, unless it is highly multimerized. Thus, specifically designed Env immunogens can activate naive B cells expressing human BCRs corresponding to precursors of broadly neutralizing HIV-1 antibodies even when the B cells display an autoreactive phenotype. PMID:26907590

  4. γδ T cell-mediated antibody-dependent cellular cytotoxicity with CD19 antibodies assessed by an impedance-based label-free real-time cytotoxicity assay

    Directory of Open Access Journals (Sweden)

    Ursula Jördis Eva Seidel

    2014-12-01

    Full Text Available γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation (SCT strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC with monoclonal antibodies (mAbs. These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL. To evaluate combination of human γδ T cells with CD19 antibodies for immunotherapy of B-lineage ALL, γδ T cells were expanded after a GMP-compliant protocol and ADCC of both primary and expanded γδ T cells with an Fc optimized CD19 antibody (4G7SDIE and a bispecific antibody with the specificities CD19 and CD16 (N19-C16 was evaluated in CD107a degranulation assays and intracellular cytokine staining (ICS. CD107a, TNF-α and IFN-γ expression of primary γδ T cells were significantly increased and correlated with CD16-expression of γδ T cells. γδ T cells highly expressed CD107a after expansion and no further increased expression by 4G7SDIE and N19-C16 was measured. Cytotoxicity of purified expanded γδ T cells targeting CD19-expressing cells was assessed in both europium-TDA release and in an impedance-based label-free method (using the xCELLigence system measuring γδ T cell lysis in real-time. Albeit in the 2 h end-point europium-TDA release assay no increased lysis was observed, in real-time xCELLigence assays both significant antibody-independent cytotoxicity and ADCC of γδ T cells were observed. The xCELLigence system outperformed the end-point europium-TDA release assay in sensitivity and allows drawing of conclusions to lysis kinetics of γδ T cells over prolonged periods of time periods. Combination of CD19 antibodies with primary as well as expanded γδ T cells exhibits an promising approach, which may enhance clinical outcome of patients with pediatric B-lineage ALL and

  5. γδ T Cell-Mediated Antibody-Dependent Cellular Cytotoxicity with CD19 Antibodies Assessed by an Impedance-Based Label-Free Real-Time Cytotoxicity Assay.

    Science.gov (United States)

    Seidel, Ursula Jördis Eva; Vogt, Fabian; Grosse-Hovest, Ludger; Jung, Gundram; Handgretinger, Rupert; Lang, Peter

    2014-01-01

    γδ T cells are not MHC restricted, elicit cytotoxicity against various malignancies, are present in early post-transplant phases in novel stem cell transplantation strategies and have been shown to mediate antibody-dependent cellular cytotoxicity (ADCC) with monoclonal antibodies (mAbs). These features make γδ T cells promising effector cells for antibody-based immunotherapy in pediatric patients with B-lineage acute lymphoblastic leukemia (ALL). To evaluate combination of human γδ T cells with CD19 antibodies for immunotherapy of B-lineage ALL, γδ T cells were expanded after a GMP-compliant protocol and ADCC of both primary and expanded γδ T cells with an Fc-optimized CD19 antibody (4G7SDIE) and a bi-specific antibody with the specificities CD19 and CD16 (N19-C16) was evaluated in CD107a-degranulation assays and intracellular cytokine staining. CD107a, TNFα, and IFNγ expression of primary γδ T cells were significantly increased and correlated with CD16-expression of γδ T cells. γδ T cells highly expressed CD107a after expansion and no further increased expression by 4G7SDIE and N19-C16 was measured. Cytotoxicity of purified expanded γδ T cells targeting CD19-expressing cells was assessed in both europium-TDA release and in an impedance-based label-free method (using the xCELLigence system) measuring γδ T cell lysis in real-time. Albeit in the 2 h end-point europium-TDA release assay no increased lysis was observed, in real-time xCELLigence assays both significant antibody-independent cytotoxicity and ADCC of γδ T cells were observed. The xCELLigence system outperformed the end-point europium-TDA release assay in sensitivity and allows drawing of conclusions to lysis kinetics of γδ T cells over prolonged periods of time periods. Combination of CD19 antibodies with primary as well as expanded γδ T cells exhibits a promising approach, which may enhance clinical outcome of patients with pediatric B-lineage ALL and requires clinical

  6. ICOS+PD-1+CXCR3+ T follicular helper cells contribute to the generation of high-avidity antibodies following influenza vaccination

    Science.gov (United States)

    Bentebibel, Salah-Eddine; Khurana, Surender; Schmitt, Nathalie; Kurup, Parvathi; Mueller, Cynthia; Obermoser, Gerlinde; Palucka, A. Karolina; Albrecht, Randy A.; Garcia-Sastre, Adolfo; Golding, Hana; Ueno, Hideki

    2016-01-01

    The immune mechanism leading to the generation of protective antibody responses following influenza trivalent inactivated vaccine (TIV) vaccinations remains largely uncharacterized. We recently reported that TIV vaccination induced a transient increase of circulating ICOS+PD-1+CXCR3+ T follicular helper (cTfh) cells in blood, which positively correlated with the induction of protective antibody responses measured at day 28. However, whether and how these T cells directly contribute to antibody response remains unclear. In this study, we analyzed the changes after TIV vaccination in the amount and the avidity of the polyclonal antibodies specific for the HA1 subunit of the pandemic H1N1 virus, and analyzed the correlation with the increase of ICOS+PD-1+CXCR3+ cTfh cells. We found that both the amount and the avidity of specific antibodies rapidly increased during the first 7 days after TIV. Importantly, the increase of ICOS+PD-1+CXCR3+ cTfh cells strongly correlated with the increase in the avidity of antibodies, particularly in subjects who did not have high affinity antibodies at baseline. We propose that ICOS+PD-1+CXCR3+ Tfh cells directly contribute to the generation of high-avidity antibodies after TIV vaccinations by selectively interacting with high affinity B cells at extrafollicular sites. PMID:27231124

  7. Analysis of T-cell-dependent and -independent antigens of Rickettsia conorii with monoclonal antibodies.

    OpenAIRE

    Feng, H M; Walker, D H; Wang, J. G.

    1987-01-01

    Four monoclonal antibodies from euthymic mice and two monoclonal antibodies from athymic mice were directed against antigens of Rickettsia conorii, as shown by both indirect immunofluorescence and an enzyme immunoassay. There was extensive cross-reactivity with other spotted fever group rickettsiae. Euthymic monoclonal antibodies 3-2 and 9-2 (immunoglobulin G2a [IgG2a]) and 27-10 (IgG1) distinctly outlined the acetone-fixed rickettsial surface, as determined by indirect immunofluorescence; on...

  8. Blinatumomab: a bispecific T cell engager (BiTE) antibody against CD19/CD3 for refractory acute lymphoid leukemia

    OpenAIRE

    Wu, JingJing; Fu, Jiaping; Zhang, Mingzhi; Liu, Delong

    2015-01-01

    Targeted therapy has been the forefront of cancer treatment. Cancer immunotherapy is the most recent focus. In addition, novel immunotherapeutics targeting B cell receptor signaling (e.g., ibrutinib), T cell receptor ( e.g., CART19), and NK cells (e.g., AFM13) are being developed. This review summarized the new development in blinatumomab (MT103/MEDI-538), a first-in-class bispecific T engager (BiTE) antibody against CD19/CD3 in patients with relapsed/refractory precursor B cell acute lymphoi...

  9. Comparison of human immune responses to purified Vero cell and human diploid cell rabies vaccines by using two different antibody titration methods.

    OpenAIRE

    Kitala, P M; Lindqvist, K J; Koimett, E; Johnson, B. K; Chunge, C N; Perrin, P.; Olsvik, O

    1990-01-01

    Antibody responses to a conventional rabies preexposure regimen of a new purified Vero cell rabies vaccine (PVRV) and a human diploid cell vaccine (HDCV) were compared in 80 healthy Kenyan veterinary students. Forty-three of the students received the PVRV and 37 received the HDCV on days 0, 7, and 28. Antibody responses were monitored by using the rapid fluorescent-focus inhibition test (RFFIT) and an inhibition enzyme immunoassay (INH EIA) on days 0, 7, 28, and 49. Both vaccines elicited a r...

  10. Radiolocalization of human small cell lung cancer and antigen-positive normal tissues using monoclonal antibody LS2D617

    International Nuclear Information System (INIS)

    The murine monoclonal antibody LS2D617, which reacts with an antigen associated with human small cell lung carcinoma (SCLC), was tested in preclinical models to assess its potential for specific targeting of tumors in human SCLC cancer patients. LS2D617 detects a cell antigen on the surface of cultured SCLC and neuroblastoma cell lines. Scatchard analysis of the binding of LS2D617 to NCIH69 SCLC cells indicates an affinity constant of about 1 x 10(8) M-1 and an epitope expression level of approximately 2 x 10(6) antigenic sites/cell. Molecular weight analysis of the target antigen and antibody competition experiments showed that LS2D617 should be classified as a SCLC Cluster 1 antibody. LS2D617 was labeled with 111In and tested for biodistribution (4, 24, 48, 72, and 96 h postinjection) in nude mice bearing the human SCLC NCIH69 tumor. Tumor values peaked at about 35% injected dose/g (Day 3) compared with about 8% injected dose/g for an irrelevant IgG1 antibody while normal tissue accumulation for both antibodies was about 2-8% injected dose/g. Immunohistochemical studies demonstrated that LS2D617 reacts with the central nervous system, peripheral nerves, endocrine tissues, and heart tissue of rabbits as it does in human tissues. The ability of LS2D617 to accumulate in vivo in normal tissues that express the specific target antigen was tested in rabbits. Rabbits given i.v. injections of 111In-LS2D617 or control labeled antibody were sacrificed at 48 h and tissues were examined by gamma well counting, autoradiography, and immunohistochemical staining for murine immunoglobulin. Specific uptake was seen in all sites defined as antigen positive by immunohistology (i.e., heart, liver bile duct, peripheral nerves, pituitary, adrenal), except the central nervous system (brain and spinal cord) which was inaccessible to antibody because of the blood brain barrier

  11. Characterization of a Novel Anti-DR5 Monoclonal Antibody WD1 with the Potential to Induce Tumor Cell Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Jing Wang; Beifen Shen; Yuanfang Ma; Yan Li; Zhou Lin; Chunxia Qiao; Ming Lv; Ming Yu; He Xiao; Qingyang Wang; Liyan Wang; Jiannan Feng

    2008-01-01

    TNF-related apoptosis. inducing ligand (TRAIL) is a TNF family member capable of inducing apoptosis. Death receptor 5(DR 51 is a key receptor of TRAIL and plays an important role in TRAIL-induced apoptosis. To prepare monoclonal antibodies (mAbs) against DR5, cDNA encoding soluble DR5(sDR5)was firstly amplified by revere transcriptase. polymerase chain reaction (RT-PCR) with specific primers, and then inserted into a prokaryotic expression vector pET-30a. The recombinant plasmid Was expressed in Escherichia coil strain BL21(DE3), and sDR5 was purified by nickel affinity chromatography. As an antigen. sDR5 Was used to immunize mice. Hybridomas secreting antibodies against sDR5 were identified. One positive clone Was selected to produce antibody, WD1. ELISA and immunofluorescence demonstrated that WD1 could bind recombinant sDR5 and membrane bound DR5 (mDR5)on Jurkat and Molt-4 cells. ATPLite assays showed that Jurkat and Molt-4 cells were sensitive to the antibody in a dose dependent manner. The Annexin V/PI assays and Giemsa's staining both showed that WD1 could induce Jurkat cell apoptosis efficiently. Transient transfection of 293T cells and indirect immunofluorescence assay demonstrated that mAb(WD1)couldn't cross. react with DR4.Our findings indicated that the novel antibody, WD1 could act as a direct agonist, bind DR5 characteristically, and initiate efficient apoptotic signaling and tumor regression. Thus, WD1 would be a leading candidate for potential cancer therapeutics. Cellular & Molecular Immunology. 2008;5(1):55-60.

  12. Potential for Natural Killer Cell-Mediated Antibody-Dependent Cellular Cytotoxicity for Control of Human Cytomegalovirus

    Directory of Open Access Journals (Sweden)

    Rebecca J. Aicheler

    2013-12-01

    Full Text Available Human cytomegalovirus (HCMV is an important pathogen that infects the majority of the population worldwide, yet, currently, there is no licensed vaccine. Despite HCMV encoding at least seven Natural Killer (NK cell evasion genes, NK cells remain critical for the control of infection in vivo. Classically Antibody-Dependent Cellular Cytotoxicity (ADCC is mediated by CD16, which is found on the surface of the NK cell in a complex with FcεRI-γ chains and/or CD3ζ chains. Ninety percent of NK cells express the Fc receptor CD16; thus, they have the potential to initiate ADCC. HCMV has a profound effect on the NK cell repertoire, such that up to 10-fold expansions of NKG2C+ cells can be seen in HCMV seropositive individuals. These NKG2C+ cells are reported to be FcεRI-γ deficient and possess variable levels of CD16+, yet have striking ADCC functions. A subset of HCMV cell surface proteins will induce robust antibody responses that could render cells susceptible to ADCC. We will consider how the strong anti-HCMV function of NKG2C+ FcεRI-γ-deficient NK cells could potentially be harnessed in the clinic to treat patients suffering from HCMV disease and in the development of an efficacious HCMV vaccine.

  13. Neuronal uptake of anti-Hu antibody, but not anti-Ri antibody, leads to cell death in brain slice cultures

    OpenAIRE

    Greenlee, John E.; Clawson, Susan A.; Kenneth E Hill; Wood, Blair; Clardy, Stacey L.; Tsunoda, Ikuo; Jaskowski, Troy D; Carlson, Noel G.

    2014-01-01

    Background Anti-Hu and anti-Ri antibodies are paraneoplastic immunoglobulin (Ig)G autoantibodies which recognize cytoplasmic and nuclear antigens present in all neurons. Although both antibodies produce similar immunohistological labeling, they recognize different neuronal proteins. Both antibodies are associated with syndromes of central nervous system dysfunction. However, the neurological deficits associated with anti-Hu antibody are associated with neuronal death and are usually irreversi...

  14. Lymphotoxin-Dependent B Cell-FRC Crosstalk Promotes De Novo Follicle Formation and Antibody Production following Intestinal Helminth Infection.

    Science.gov (United States)

    Dubey, Lalit Kumar; Lebon, Luc; Mosconi, Ilaria; Yang, Chen-Ying; Scandella, Elke; Ludewig, Burkhard; Luther, Sanjiv A; Harris, Nicola L

    2016-05-17

    Secondary lymphoid tissues provide specialized niches for the initiation of adaptive immune responses and undergo a remarkable expansion in response to inflammatory stimuli. Although the formation of B cell follicles was previously thought to be restricted to the postnatal period, we observed that the draining mesenteric lymph nodes (mLN) of helminth-infected mice form an extensive number of new, centrally located, B cell follicles in response to IL-4Rα-dependent inflammation. IL-4Rα signaling promoted LTα1β2 (lymphotoxin) expression by B cells, which then interacted with CCL19 positive stromal cells to promote lymphoid enlargement and the formation of germinal center containing B cell follicles. Importantly, de novo follicle formation functioned to promote both total and parasite-specific antibody production. These data reveal a role for type 2 inflammation in promoting stromal cell remodeling and de novo follicle formation by promoting B cell-stromal cell crosstalk. PMID:27160906

  15. Targeting and killing of glioblastoma with activated T cells armed with bispecific antibodies

    International Nuclear Information System (INIS)

    Since most glioblastomas express both wild-type EGFR and EGFRvIII as well as HER2/neu, they are excellent targets for activated T cells (ATC) armed with bispecific antibodies (BiAbs) that target EGFR and HER2. ATC were generated from PBMC activated for 14 days with anti-CD3 monoclonal antibody in the presence of interleukin-2 and armed with chemically heteroconjugated anti-CD3×anti-HER2/neu (HER2Bi) and/or anti-CD3×anti-EGFR (EGFRBi). HER2Bi- and/or EGFRBi-armed ATC were examined for in vitro cytotoxicity using MTT and 51Cr-release assays against malignant glioma lines (U87MG, U118MG, and U251MG) and primary glioblastoma lines. EGFRBi-armed ATC killed up to 85% of U87, U118, and U251 targets at effector:target ratios (E:T) ranging from 1:1 to 25:1. Engagement of tumor by EGFRBi-armed ATC induced Th1 and Th2 cytokine secretion by armed ATC. HER2Bi-armed ATC exhibited comparable cytotoxicity against U118 and U251, but did not kill HER2-negative U87 cells. HER2Bi- or EGFRBi-armed ATC exhibited 50—80% cytotoxicity against four primary glioblastoma lines as well as a temozolomide (TMZ)-resistant variant of U251. Both CD133– and CD133+ subpopulations were killed by armed ATC. Targeting both HER2Bi and EGFRBi simultaneously showed enhanced efficacy than arming with a single BiAb. Armed ATC maintained effectiveness after irradiation and in the presence of TMZ at a therapeutic concentration and were capable of killing multiple targets. High-grade gliomas are suitable for specific targeting by armed ATC. These data, together with additional animal studies, may provide the preclinical support for the use of armed ATC as a valuable addition to current treatment regimens

  16. Overexpression of CHOP alone and in combination with chaperones is effective in improving antibody production in mammalian cells.

    Science.gov (United States)

    Nishimiya, Daisuke; Mano, Takashi; Miyadai, Kenji; Yoshida, Hiroko; Takahashi, Tohru

    2013-03-01

    Secretory capacities including folding and assembly are believed to be limiting factors in the establishment of mammalian cell lines producing high levels of recombinant therapeutic proteins. To achieve industrial success, it is also important to improve protein folding, assembly, and secretory processes in combination with increasing transcription and translation. Here, we identified the expression of CHOP/Gadd153 and GRP78, which are unfolded protein response (UPR)-related genes, correlated with recombinant antibody production in stable CHO cells. Subsequently, CHOP overexpression resulted in increasing recombinant antibody production in some mammalian cell lines, and in addition a threefold further enhancement was obtained by combining expression with UPR-related genes or ER chaperones in transient assays. Overexpression of CHOP had no effect on the biochemical characteristics of the product. These results suggest overexpression of CHOP and its combinations may be an effective method to efficiently select a single cell line with a high level of antibody production in the development of cell lines for manufacturing. PMID:22926643

  17. Structural evidence for evolution of shark Ig new antigen receptor variable domain antibodies from a cell-surface receptor.

    Science.gov (United States)

    Streltsov, V A; Varghese, J N; Carmichael, J A; Irving, R A; Hudson, P J; Nuttall, S D

    2004-08-24

    The Ig new antigen receptors (IgNARs) are single-domain antibodies found in the serum of sharks. Here, we report 2.2- and 2.8-A structures of the type 2 IgNAR variable domains 12Y-1 and 12Y-2. Structural features include, first, an Ig superfamily topology transitional between cell adhesion molecules, antibodies, and T cell receptors; and, second, a vestigial complementarity-determining region 2 at the "bottom" of the molecule, apparently discontinuous from the antigen-binding paratope and similar to that observed in cell adhesion molecules. Thus, we suggest that IgNARs originated as cell-surface adhesion molecules coopted to the immune repertoire and represent an evolutionary lineage independent of variable heavy chain/variable light chain type antibodies. Additionally, both 12Y-1 and 12Y-2 form unique crystallographic dimers, predominantly mediated by main-chain framework interactions, which represent a possible model for primordial cell-based interactions. Unusually, the 12Y-2 complementarity-determining region 3 also adopts an extended beta-hairpin structure, suggesting a distinct selective advantage in accessing cryptic antigenic epitopes. PMID:15304650

  18. Polyclonal B-cell activation by Neisseria meningitidis capsular polysaccharides elicit antibodies protective against Trypanosoma cruzi infection in vitro.

    Science.gov (United States)

    Oliveira, T G; Milani, S R; Travassos, L R

    1996-01-01

    A hyperimmune rabbit antiserum against group C Neisseria meningitidis agglutinated and lysed Trypanosoma cruzi metacyclic trypomastigotes in a complement-mediated reaction. Immunization of rabbits with the purified polysaccharide C from N. meningitidis and of human volunteers with the AC-polysaccharide vaccine against meningitis also resulted in antibody production cross-reactive with T. cruzi infective forms. The rabbit antibodies bound to parasites, lysed metacyclic forms, and recognized several components from lysates of cell-derived trypomastigotes. The sera from six human volunteers reacted with cell-cultured trypomastigotes in vitro, lysed these forms, and recognized glycoconjugates migrating diffusely on the top of immunoblots. One serum also reacted with the isolated mucin-like glycoconjugate carrying the Ssp-3 epitope from cell-derived trypomastigotes, but treatment with sialidase did not abolish this reactivity. The anti-AC human antiserum also protected against HeLa cell infection and markedly decreased the number of parasites liberated after cell burst. The polyclonal response that resulted from human immunization with N. meningitidis polysaccharides A and C comprised trypanolytic antibodies that recognized nonsialylated epitopes expressed on infective forms of the parasite. It is suggested that human AC vaccination could be potentially helpful as an adjuvant to a specific immunotherapy of Chagas disease, developed with native or recombinant antigens of the parasite. PMID:8811466

  19. Thyroid Antibodies

    Science.gov (United States)

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

  20. Immunohistochemical analysis of Langerhans cells in chronic gingivitis using anti-CD1a antibody

    Directory of Open Access Journals (Sweden)

    Shweta Jaitley

    2014-01-01

    Full Text Available Background: The Langerhans cells (LCs are dendritic cells (DCs which belong to the group of antigen presenting cells (APCs. Their function is to recognize the antigen, capture it, and present it to the T lymphocytes; thus initiating an early immune response. The antigen presenting functional LCs may play an important part in initiation and development of gingivitis. The aim of this study was to analyze the density, intraepithelial distribution, and morphology of LCs in gingival epithelium among different age groups with chronic gingivitis and to compare it with that of normal gingiva. Materials and Methods: Immunohistochemistry (IHC was performed to study LCs in normal gingival epithelium (n = 10 and gingival epithelium in chronic gingivitis (n = 30 using anti-CD1a antibody. Mann Whitney U test was performed to compare the density of LCs in normal gingiva with chronic gingivitis. The distribution of LCs in various layers of the epithelium within the three age groups was analyzed using Kruskal-Wallis test. P value less than 0.05 was considered as significant. Results: The density of LCs in chronic gingivitis was significantly higher then that of normal gingiva. Comparing different age groups, the younger individuals had more number of LCs which were located in the superficial layers of gingival epithelium. In chronic gingivitis, higher number of LCs were located in deeper layers when compared with that of normal gingiva. Three morphological types of CD1a positive LCs were observed in normal gingiva, out of which the density of LCs with branched dendritic processes was highest in normal gingiva. Conclusion: The LCs showed variable number, location, and morphology which indicated their adaptation for function in chronic gingivitis.

  1. Cleavage efficient 2A peptides for high level monoclonal antibody expression in CHO cells.

    Science.gov (United States)

    Chng, Jake; Wang, Tianhua; Nian, Rui; Lau, Ally; Hoi, Kong Meng; Ho, Steven C L; Gagnon, Peter; Bi, Xuezhi; Yang, Yuansheng

    2015-01-01

    Linking the heavy chain (HC) and light chain (LC) genes required for monoclonal antibodies (mAb) production on a single cassette using 2A peptides allows control of LC and HC ratio and reduces non-expressing cells. Four 2A peptides derived from the foot-and-mouth disease virus (F2A), equine rhinitis A virus (E2A), porcine teschovirus-1 (P2A) and Thosea asigna virus (T2A), respectively, were compared for expression of 3 biosimilar IgG1 mAbs in Chinese hamster ovary (CHO) cell lines. HC and LC were linked by different 2A peptides both in the absence and presence of GSG linkers. Insertion of a furin recognition site upstream of 2A allowed removal of 2A residues that would otherwise be attached to the HC. Different 2A peptides exhibited different cleavage efficiencies that correlated to the mAb expression level. The relative cleavage efficiency of each 2A peptide remains similar for expression of different IgG1 mAbs in different CHO cells. While complete cleavage was not observed for any of the 2A peptides, GSG linkers did enhance the cleavage efficiency and thus the mAb expression level. T2A with the GSG linker (GT2A) exhibited the highest cleavage efficiency and mAb expression level. Stably amplified CHO DG44 pools generated using GT2A had titers 357, 416 and 600 mg/L for the 3 mAbs in shake flask batch cultures. Incomplete cleavage likely resulted in incorrectly processed mAb species and aggregates, which were removed with a chromatin-directed clarification method and protein A purification. The vector and methods presented provide an easy process beneficial for both mAb development and manufacturing. PMID:25621616

  2. Interaction of human IgG chimeric antibodies with the human FcRI and FcRII receptors: requirements for antibody-mediated host cell-target cell interaction.

    Science.gov (United States)

    Walker, M R; Woof, J M; Brüggemann, M; Jefferis, R; Burton, D R

    1989-04-01

    Chimeric monoclonal antibodies (McAb), specific for the hapten 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP), expressing human IgG1, IgG2, IgG3 and IgG4 subclass constant domains, have been examined for their ability to interact with the human FcRII receptor. Human red blood cells (RBC) sensitized by each of these McAbs have been assayed for their ability to form rosettes with the human histiocytic lymphoma U937 cell line, human B cell line Daudi and erythroblastoid K562 cell line. IgG1 and IgG3 sensitized RBC formed significant rosettes with the FcR- and FcRII+ Daudi and K562 cell lines, the percentage of cells forming rosettes being directly proportional to the degree of sensitization of the RBC. Bromelin treating Daudi cells did not alter this pattern of reactivity, whereas bromelin treated FcRI+ and FcRII+ U937 cells formed significant resettes with IgG1, IgG3 and IgG4 sensitized RBC, demonstrating a difference in the IgG subclass specificity between human FcRI and FcRII. Murine IgG2b anti-NIP sensitized RBC did not form rosettes with any cell line tested; however, RBC sensitized by some members of a panel of murine IgG1 McAb, specific for the glycophorin A molecule, were able to form rosettes with Daudi, U937 and K562 cells. This interaction was enhanced by bromelin treating the Daudi or U937 cells and can be correlated to the disposition of the epitopes recognized, relative to the target cell membrane, those McAbs recognizing epitopes furthest from the RBC surface being most effective in interacting with FcRII. The data are interpreted in terms of a simple model for antibody-mediated cell--cell interaction. PMID:2716734

  3. Regulation of B Cell Differentiation by Intracellular Membrane-Associated Proteins and microRNAs: Role in the Antibody Response.

    Science.gov (United States)

    Lou, Zheng; Casali, Paolo; Xu, Zhenming

    2015-01-01

    B cells are central to adaptive immunity and their functions in antibody responses are exquisitely regulated. As suggested by recent findings, B cell differentiation is mediated by intracellular membrane structures (including endosomes, lysosomes, and autophagosomes) and protein factors specifically associated with these membranes, including Rab7, Atg5, and Atg7. These factors participate in vesicle formation/trafficking, signal transduction and induction of gene expression to promote antigen presentation, class switch DNA recombination (CSR)/somatic hypermutation (SHM), and generation/maintenance of plasma cells and memory B cells. Their expression is induced in B cells activated to differentiate and further fine-tuned by immune-modulating microRNAs, which coordinates CSR/SHM, plasma cell differentiation, and memory B cell differentiation. These short non-coding RNAs would individually target multiple factors associated with the same intracellular membrane compartments and collaboratively target a single factor in addition to regulating AID and Blimp-1. These, together with regulation of microRNA biogenesis and activities by endosomes and autophagosomes, show that intracellular membranes and microRNAs, two broadly relevant cell constituents, play important roles in balancing gene expression to specify B cell differentiation processes for optimal antibody responses. PMID:26579118

  4. Regulation of B cell differentiation by intracellular membrane associated proteins and microRNAs: role in the antibody response

    Directory of Open Access Journals (Sweden)

    Zheng eLou

    2015-10-01

    Full Text Available B cells are central to adaptive immunity and their functions in antibody responses are exquisitely regulated. As suggested by recent findings, B cell differentiation is mediated by intracellular membrane structures (including endosomes, lysosomes and autophagosomes and protein factors specifically associated with these membranes, including Rab7, Atg5 and Atg7. These factors participate in vesicle formation/trafficking, signal transduction and induction of gene expression to promote antigen presentation, CSR/SHM, and generation/maintenance of plasma cells and memory B cells. Their expression is induced in B cells activated to differentiate and further fine-tuned by immune-modulating microRNAs, which coordinates CSR/SHM, plasma cell differentiation and memory B cell differentiation. These short non-coding RNAs would individually target multiple factors associated with the same intracellular membrane compartments and collaboratively target a single factor in addition to regulate AID and Blimp-1. These, together with regulation of microRNA biogenesis and activities by endosomes and autophagosomes, show that intracellular membranes and microRNAs, two broadly relevant cell constituents, play important roles in balancing gene expression to specify B cell differentiation processes for optimal antibody responses.

  5. Indirect immunofluorescence (IIF) of normal washed peripheral blood cells to demonstrate antineutrophil cytoplasmic antibodies (ANCA)

    OpenAIRE

    Paspaliaris, B; Pamio, M; Savige, J.

    2000-01-01

    Background—The "International consensus document on testing and reporting of antineutrophil cytoplasmic antibodies (ANCA)" requires all sera to be examined by indirect immunofluorescence (IIF). However, commercial neutrophil slides are expensive, fluorescence patterns can be difficult to interpret, and coincidental antinuclear antibodies (ANA) cannot be demonstrated; in addition, in house cytospin neutrophil preparations are time consuming to prepare and deteriorate with time.

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

    NARCIS (Netherlands)

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

    1992-01-01

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

  7. T10B9 monoclonal antibody: A short-acting nonstimulating monoclonal antibody that spares γδ T-cells and treats and prevents cellular rejection

    Directory of Open Access Journals (Sweden)

    Thomas H Waid

    2009-06-01

    Full Text Available Thomas H Waid1, John S Thompson1, Maria Siemionow2, Stephen A Brown1 1Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, USA; 2Cleveland Clinic, Cleveland, Ohio, USAAbstract: T10B9.1A-31/MEDI-500 is a nonmitogenic immunoglobulin M kappa murine monoclonal antibody (mAb directed against the alpha-beta (αβ heterodimer of the T-lymphocyte receptor complex. The hybridoma was first produced by fusing spleen cells from BALB/C mice immunized with human peripheral blood T-lymphocytes with SP2/O-Ag14 mutant myeloma cells. The mAb is produced and purified using multistep ion exchange and molecular sieve chromatography protocols. T10B9 has been used successfully to treat acute cellular rejection in renal transplantation and as an immunosuppression induction agent in heart and simultaneous kidney-pancreas transplantation. Because T10B9 is nonmitogenic and causes minimal cytokine release, both treatment of rejection and induction of immunosuppression were accomplished with significantly fewer and milder untoward effects (cytokine release syndrome than its comparator OKT3. Since T10B9 is directed against the αβ heterodimer of the CD3 epitope, it spares the gamma delta (γδ region. These gamma delta (γδ T cells have a unique role in the immune response controlling many serious human diseases and perhaps facilitating the development of immunologic tolerance. T10B9 has a relatively short duration of action, depleting T cells for only 10 to 14 days, unlike the protracted depletion seen with thymoglobulin and Campath-1H. There is no B-lymphocyte depletion with T10B9 as there is with both of the aforementioned reagents. The lack of prolonged lymphocyte depletion may account for less infection observed with T10B9 treatment.Keywords: T10B9.1A-31, γδ T-cell, monoclonal antibody, Campath-1H, thymoglobulin, OKT3

  8. Selective loss of Purkinje cells in a patient with anti-gliadin-antibody-positive autoimmune cerebellar ataxia

    Directory of Open Access Journals (Sweden)

    Hasegawa Akira

    2011-02-01

    Full Text Available Abstract The patient was an 84-year-old woman who had the onset of truncal ataxia at age 77 and a history of Basedow's disease. Her ataxic gait gradually deteriorated. She could not walk without support at age 81 and she was admitted to our hospital at age 83. Gaze-evoked nystagmus and dysarthria were observed. Mild ataxia was observed in all limbs. Her deep tendon reflex and sense of position were normal. IgA anti-gliadin antibody, IgG anti-gliadin antibody, anti-SS-A/Ro antibody, anti-SS-B/La antibody and anti-TPO antibody were positive. A conventional brain MRI did not show obvious cerebellar atrophy. However, MRI voxel based morphometry (VBM and SPECT-eZIS revealed cortical cerebellar atrophy and reduced cerebellar blood flow. IVIg treatment was performed and was moderately effective. After her death at age 85, the patient was autopsied. Neuropathological findings were as follows: selective loss of Purkinje cells; no apparent degenerative change in the efferent pathways, such as the dentate nuclei or vestibular nuclei; no prominent inflammatory reaction. From these findings, we diagnosed this case as autoimmune cerebellar atrophy associated with gluten ataxia. All 3 autopsies previously reported on gluten ataxia have noted infiltration of inflammatory cells in the cerebellum. In this case, we postulated that the infiltration of inflammatory cells was not found because the patient's condition was based on humoral immunity. The clinical conditions of gluten ataxia have not yet been properly elucidated, but are expected to be revealed as the number of autopsied cases increases.

  9. 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.

  10. Transplantation tolerance mediated by suppressor T cells and suppressive antibody in a recipient of a renal transplant.

    Science.gov (United States)

    Suzuki, S; Mizuochi, I; Sada, M; Amemiya, H

    1985-10-01

    This is a report of a patient who underwent cadaveric renal transplantation in spite of the presence of three HLA-A, B and two DR antigen mismatches between the recipient and donor. The recipient received more than 20 units of blood before transplantation. The crossmatch between the recipient's serum and the T and B cells of the donor was negative. The patient exhibited hepatic dysfunction from the early posttransplant period, which eventually led to discontinuation of azathioprine or Bredinin at one year posttransplantation. Thereafter, only betamethasone was administered once every 3 days. The patients has maintained good renal function for more than one year following withdrawal of the immunosuppressants. It appeared that transplantation tolerance was established in this patient. Therefore, we examined the mechanisms sustaining the tolerance. Both nylon-wool-adherent, alloantigen-specific suppressor T cells and nonadherent, nonspecific suppressor T cells were observed in the lymphocytes of the patient after transplantation. It was also shown that suppressive antibody was present in the serum directed toward the clone of autologous lymphocytes that reacted with the mixed lymphocyte reaction (MLR) antigen of the donor. In the inhibition test against various types of MLR antigens using this suppressive antibody, it was found that the reaction against the donor cells was suppressed when the responding cells shared the same class I antigen with the recipient. When the stimulating cells had the class II antigen of the donor, the reaction of the specific responding cells was also inhibited. These inhibiting effects were only seen when the responding cells were pretreated with the antibody, but not when stimulating cells were pretreated. PMID:2413592

  11. Characterization of a monoclonal antibody cell culture production process using a quality by design approach.

    Science.gov (United States)

    Horvath, Brian; Mun, Melissa; Laird, Michael W

    2010-07-01

    The goal of quality by design (QbD) in cell culture manufacturing is to develop manufacturing processes which deliver products with consistent critical quality attributes (CQAs). QbD approaches can lead to better process understanding through the use of process parameter risk ranking and statistical design of experiments (DOE). The QbD process starts with an analysis of process parameter risk with respect to CQAs and key performance indicators (KPIs). Initial DOE study designs and their factor test ranges are based on the outcomes of the process parameter risk ranking exercises. Initial DOE studies screen factors for significant influences on CQAs as well as characterize responses for process KPIs. In the case study provided here, multifactor process characterization studies using a scale-down model resulted in significant variation in charge heterogeneity of a monoclonal antibody (MAb) as measured by ion-exchange chromatography (IEC). Iterative DOE studies, using both screening and response surface designs, were used to narrow the operating parameter ranges so that charge heterogeneity could be controlled to an acceptable level. The data from the DOE studies were used to predict worst-case conditions, which were then verified by testing at those conditions. Using the approach described here, multivariate process parameter ranges were identified that yield acceptable CQA levels and that still provide operational flexibility for manufacturing. PMID:20300882

  12. White blood cell scintigraphy with monoclonal antibodies in the study of the infected endoprosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Sciuk, J.; Puskas, C.; Schober, O. (Muenster Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin); Greitemann, B. (Muenster Univ. (Germany). Klinik und Poliklinik fuer Allgemeine Orthopaedie)

    1992-07-01

    Forty-three patients with suspected infection of a hip or a knee prosthesis were studied with white blood cell scintigraphy (WBC), using technetium-99m (n=37) or iodine-123 (n=6) labelled monoclonal mouse antibody (MOA). Previously, all patients had undergone skeletal scintigraphy, which was performed as a three-phase study in 33 cases. The final diagnosis was established by open surgery, histology and culture in 37 cases, by puncture and cultere in 3 cases, and by clinical follow-up of at least 6 months in 3 cases. Eighteen prostheses were infected, 25 uninfected. The delayed phase of skeletal scintigraphy had a sensitivity of 92%, a specificity of 24% and an accuracy of 48% in the detection of infection. The perfusion and blood pool activity of the three-phase bone scan had a sensitivity of 67%, a specificity of 71% and an accuracy of 70%. The diagnostic value of WBC was sensitivty 89%, specificity 84% and accuracy 86%. WBC with {sup 99m}-Tc-MOA is easy to perform and always available. Its diagnostic accuracy is similar to conventional WBC scintigraphy with either indium-111 or {sup 99m}-Tc. (orig.).

  13. Rugged single domain antibody detection elements for Bacillus anthracis spores and vegetative cells.

    Directory of Open Access Journals (Sweden)

    Scott A Walper

    Full Text Available Significant efforts to develop both laboratory and field-based detection assays for an array of potential biological threats started well before the anthrax attacks of 2001 and have continued with renewed urgency following. While numerous assays and methods have been explored that are suitable for laboratory utilization, detection in the field is often complicated by requirements for functionality in austere environments, where limited cold-chain facilities exist. In an effort to overcome these assay limitations for Bacillus anthracis, one of the most recognizable threats, a series of single domain antibodies (sdAbs were isolated from a phage display library prepared from immunized llamas. Characterization of target specificity, affinity, and thermal stability was conducted for six sdAb families isolated from rounds of selection against the bacterial spore. The protein target for all six sdAb families was determined to be the S-layer protein EA1, which is present in both vegetative cells and bacterial spores. All of the sdAbs examined exhibited a high degree of specificity for the target bacterium and its spore, with affinities in the nanomolar range, and the ability to refold into functional antigen-binding molecules following several rounds of thermal denaturation and refolding. This research demonstrates the capabilities of these sdAbs and their potential for integration into current and developing assays and biosensors.

  14. Recombinant Outer Capsid Glycoprotein (VP7 of Rotavirus Expressed in Insect Cells Induces Neutralizing Antibodies in Rabbits

    Directory of Open Access Journals (Sweden)

    H Keyvani

    2012-04-01

    Full Text Available Background:Rotaviruses cause diarrhea in infants and young children worldwide. Rotavirus outer capsid protein, VP7 is major neutralizing antigen that is important component of subunit vaccine to prevent rotavirus infection.Many efforts have been done to produce recombinant VP7 that maintain native characteristics.We used baculovirus expression system to produce rotavirus VP7 protein and to study its immunogenicity. Methods: Simian rotavirus SA11 full-length VP7 ORF was cloned into a cloning plasmid and then the cloned gene was inserted into the linear DNA of baculovirus Autographa californica Nuclear Polyhedrosis Virus (AcNPV downstream of the polyhedrin promoter by in vitro recombination reactions. The expressed VP7 in the insect cells was recognized by rabbit hyperimmune serum raised against SA11 rotavirus by Immunofluorescence and western blotting assays. Rabbits were immunized subcutaneously by cell extracts expressing VP7 protein. Results: Reactivity with anti-rotavirus antibody suggested that expressed VP7 protein had native antigenic determinants.Injection of recombinant VP7 in rabbits elicited the production of serum antibodies,which were able to recognize VP7 protein from SA11 rotavirus by Western blotting test and neutralized SA11 rotavirus in cell culture.Conclusion: Recombinant outer capsid glycoprotein (VP7 of rotavirus expressed in insect cells induces neutralizing antibodies in rabbits and may be a candidate of rotavirus vaccine.

  15. The use of fibronectin-coated polyvinyl chloride microtest plates to detect monoclonal antibody-binding to adherent tumor cells

    International Nuclear Information System (INIS)

    This report describes the use of fibronectin-coated polyvinyl chloride (PVC) plates as a time-saving modification in an assay measuring antibody-binding to live adherent tumor cells. Three cell lines (A-431, Colo 16 and UCLA-SO-P3) derived from human squamous cell carcinomas (SCC) and forming monolayers in cultures were plated onto flexible PVC microtest plates rather than the commonly-used rigid polystyrene plates. In PVC plates, two of the three cell lines (A-431 and Colo 16) grew as foci of clumped cells instead of monolayers. Coating of the plates with plasma fibronectin restored the monolayer morphology. [125I]Staphylococcal protein A radioimmunoassays measuring the binding of a monoclonal anti-β2 microglobulin antibody to the cells were slightly, but consistently, more sensitive in coated PVC plates than in polystyrene plates. In contrast, the sensitivity of the radioimmunoassay was remarkably constant when the assay was performed on the third cell line (UCLA-SO-P3), which formed monolayers in any of the conditions tested. Preliminary experiments suggested that the inability to form monolayers on uncoated PVC plates correlates with the amount of fibronectin associated with the cell surface. (Auth.)

  16. Rapid alternative to the clonogenic assay for measuring antibody and complement-mediated killing of tumor cells

    International Nuclear Information System (INIS)

    A study of the methods used to quantitate killing of tumor cells by antibody and complement has highlighted a number of problems. Using leukemia as a model, the authors have found that the release of 51Cr from labeled tumor cells treated with antibody and complement can be an equivocal measure of cell viability. Combined with its restricted sensitivity (less than a 2 log range of cell killing) this makes this widely used assay of questionable value for detecting small numbers of viable cells, or for identifying subpopulations of complement-resistant cells. As an alternative a [125I]iododeoxyuridine uptake assay has been developed, that combines the simplicity and rapidity of the 51Cr release technique with the sensitivity of a clonogenic assay. This method eliminates the problem of spontaneous isotope release, inherent in prelabeling assays, and variability from experiment to experiment can be avoided by including a viable cell standard curve within each assay. The sensitivity of the 125IUdR uptake method, which can be completed within a day, is similar to that of a 10 day methylcellulose cloning assay and was capable of detecting the presence of a minor subpopulation of complement-resistant tumor cells

  17. LGR5 expressing cells of hair follicle as potential targets for antibody mediated anti-cancer laser therapy

    Science.gov (United States)

    Popov, Boris V.

    2013-02-01

    Near infrared laser immunotherapy becomes now a new promising research field to cure the patients with cancers. One of the critical limitation in medical application of this treatment is availability of the specific markers for delivery of laser-sensitive nanoparticles. When coupled to antibodies to the cancer stem cells markers these nanoparticles may be delivered to the cancer tissue and mediate the laser induced thermolysis of the cancer stem cells that initiate and drive growth of cancer. This paper addresses the Lgr5 cell surface marker mediating the Wnt/β-catenin signal transduction as a potential target for anti-cancer laser immunotherapy of skin cancers.

  18. Amplification of rabies virus-induced stimulation of human T-cell lines and clones by antigen-specific antibodies.

    OpenAIRE

    Celis, E; Wiktor, T J; Dietzschold, B.; Koprowski, H

    1985-01-01

    The effect of antigen-specific antibodies on the response of human T-cell lines and clones to rabies virus was studied. Plasmas from rabies-immune vaccine recipients, but not those from nonimmune individuals, enhanced the proliferative response of rabies-reactive T cells to whole inactivated virus or to the purified glycoprotein and nucleocapsid from the rabies virion. Rabies-immune plasma also increased the antigen-induced production of gamma interferon by the rabies-specific T-cell lines. E...

  19. Characterization of Plasminogen Binding to NB4 Promyelocytic Cells Using Monoclonal Antibodies against Receptor-Induced Binding Sites in Cell-Bound Plasminogen

    Directory of Open Access Journals (Sweden)

    Mercè Jardí

    2012-01-01

    Full Text Available The NB4 promyelocytic cell line exhibits many of the characteristics of acute promyelocytic leukemia blast cells, including the translocation (15 : 17 that fuses the PML gene on chromosome 15 to the RARα gene on chromosome 17. These cells have a very high fibrinolytic capacity. In addition to a high secretion of urokinase, NB4 cells exhibit a 10-fold higher plasminogen binding capacity compared with other leukemic cell lines. When tissue-type plasminogen activator was added to acid-treated cells, plasmin generation was 20–26-fold higher than that generated by U937 cells or peripheral blood neutrophils, respectively. We found that plasminogen bound to these cells can be detected by fluorescence-activated cell sorting using an antiplasminogen monoclonal antibody that specifically reacts with this antigen when it is bound to cell surfaces. All-trans retinoid acid treatment of NB4 cells markedly decreased the binding of this monoclonal antibody. This cell line constitutes a unique model to explore plasminogen binding and activation on cell surfaces that can be modulated by all-trans retinoid acid treatment.

  20. INFLUENCE OF AGING ON ANTIBODY-FORMATION INVIVO AFTER IMMUNIZATION WITH THE PRIMARY T-CELL DEPENDENT ANTIGEN HELIX-POMATIA HEMOCYANIN

    NARCIS (Netherlands)

    DEGREEF, GE; KALLENBERG, CGM; VANSTAALDUINEN, GJ; REMARQUE, EJ; TJANDRA, YI; HIJMANS, W

    1992-01-01

    The in vivo antibody response to the primary T-cell dependent antigen Helix pomatia Haemocyanin (HPH) was studied, in order to detect the possible presence of a humoral immune deficiency in ageing. The IgG subclass distribution of the specific antibodies was also determined. In order to define a dos

  1. Anti-β2GPI antibodies stimulate endothelial cell microparticle release via a nonmuscle myosin II motor protein-dependent pathway

    OpenAIRE

    Betapudi, Venkaiah; Lominadze, George; Hsi, Linda; Willard, Belinda; Wu, Meifang; McCrae, Keith R

    2013-01-01

    Activation of endothelial cells by anti-β2GPI antibodies causes myosin RLC phosphorylation, leading to actin-myosin association.In response to anti-β2GPI antibodies, release of endothelial microparticles, but not E-selectin expression, requires actomyosin assembly.

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

    Science.gov (United States)

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

    2006-01-01

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

  3. Suppression of in vivo polyclonal IgE responses by monoclonal antibody to the lymphokine B-cell stimulatory factor 1.

    OpenAIRE

    Finkelman, F D; Katona, I M; Urban, J F; Snapper, C M; Ohara, J; Paul, W E

    1986-01-01

    The lymphokine B-cell stimulatory factor 1 (BSF-1) has been shown to greatly enhance the differentiation of lipopolysaccharide-activated B cells into IgG1- and IgE-secreting cells in vitro. To determine whether in vivo IgG1 and IgE antibody responses are BSF-1 dependent, the ability of a monoclonal rat IgG1 anti-BSF-1 antibody, 11B11, to affect polyclonal IgG1 and IgE production in mice infected with the nematode parasite Nippostrongylus brasiliensis or injected with a purified goat antibody ...

  4. [High molecular weight protein detected in higher plant cells by antibodies against dynein is associated with vesicular organelles including Golgi apparatus].

    Science.gov (United States)

    Shanina, N A; Lazareva, E M; Chentsov, Iu S; Smirnova, E A

    2008-01-01

    The cytoplasmic dynein is a multisubunit complex driving organelles along microtubules to their minus-end. We used antibodies against two functional domains (motor and microtubule-binding) of one of principal components of the complex--dynein heavy chain of slime mould Dictyostelium discoideum--to test root meristem cells of wheat Triticum aestivum. The antibodies reacted with a high molecular weight protein (> 500 kDa) in the total cell extract and the band recognized by the antibodies in plant extracts had a lower electrophoretic mobility than the high molecular weight band of mammalian dynein. Antibodies coupled to protein A-Sepharose precipitated the high molecular weight protein from the purified cell extracts. Immunocytochemical analysis demonstrated that the antigen recognized by antibodies against dynein heavy chains is associated with the vesicles whose localization depends on the cell cycle stage. The antigen-positive vesicles were localized to the perinuclear region in interphase and early prophase, to the spindle periphery and to spindle pole region during mitosis, and to the interzonal region in the period of fragmoplast and cell plate formation. Some antigen-positive vesicles also reacted with antibodies against Golgi protein markers. The obtained data indicate that higher plant cells contain a high molecular weight protein interacting with antibodies against the motor and microtubules-binding domains of Dictyostelium dynein heavy chain. The revealed antigen was associated with the vesicular structures in the cytoplasm including the Golgi apparatus. PMID:18409378

  5. IgE antipolymyxin B antibody formation in a T cell-depleted bone marrow transplant patient

    International Nuclear Information System (INIS)

    The production of IgE-class antibody specific for polymyxin B is documented in an 18-year-old white female acute myelocytic leukemic patient in relapse. The patient was rendered T cell--deficient by total-body x irradiation and antihuman thymocyte globulin for the purpose of bone marrow transplantation. Thereafter, symptoms of nasal congestion, rhinorrhea, and perinasal urtication produced by topical application of a polymyxin solution were noted. Reaginic activity mediated by an IgE antibody against polymyxin is documented by Prausnitz-Kuestner--type passive transfer reactions and by an indirect hemagglutination technique developed for these studies. The occurrence of type I hypersensitivity to this topical antibiotic is rare. It is speculated that pharmaceuticals normally having a low sensitizing potential might demonstrate increased reaginic immunogenicity in a spontaneously or iatrogenically T cell-depleted patient

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

    Directory of Open Access Journals (Sweden)

    Dale O Starkie

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

  7. Human invariant NKT cell subsets differentially promote differentiation, antibody production, and T cell stimulation by B cells in vitro.

    OpenAIRE

    O'Reilly, Vincent

    2013-01-01

    PUBLISHED Invariant NK T (iNKT) cells can provide help for B cell activation and Ab production. Because B cells are also capable of cytokine production, Ag presentation, and T cell activation, we hypothesized that iNKT cells will also influence these activities. Furthermore, subsets of iNKT cells based on CD4 and CD8 expression that have distinct functional activities may differentially affect B cell functions. We investigated the effects of coculturing expanded human CD4(+), CD8α(+), and ...

  8. Mosquito Saliva Increases Endothelial Permeability in the Skin, Immune Cell Migration, and Dengue Pathogenesis during Antibody-Dependent Enhancement.

    Science.gov (United States)

    Schmid, Michael A; Glasner, Dustin R; Shah, Sanjana; Michlmayr, Daniela; Kramer, Laura D; Harris, Eva

    2016-06-01

    Dengue remains the most prevalent arthropod-borne viral disease in humans. While probing for blood vessels, Aedes aegypti and Ae. albopictus mosquitoes transmit the four serotypes of dengue virus (DENV1-4) by injecting virus-containing saliva into the skin. Even though arthropod saliva is known to facilitate transmission and modulate host responses to other pathogens, the full impact of mosquito saliva on dengue pathogenesis is still not well understood. Inoculating mice lacking the interferon-α/β receptor intradermally with DENV revealed that mosquito salivary gland extract (SGE) exacerbates dengue pathogenesis specifically in the presence of enhancing serotype-cross-reactive antibodies-when individuals already carry an increased risk for severe disease. We further establish that SGE increases viral titers in the skin, boosts antibody-enhanced DENV infection of dendritic cells and macrophages in the dermis, and amplifies dendritic cell migration to skin-draining lymph nodes. We demonstrate that SGE directly disrupts endothelial barrier function in vitro and induces endothelial permeability in vivo in the skin. Finally, we show that surgically removing the site of DENV transmission in the skin after 4 hours rescued mice from disease in the absence of SGE, but no longer prevented lethal antibody-enhanced disease when SGE was present. These results indicate that SGE accelerates the dynamics of dengue pathogenesis after virus transmission in the skin and induces severe antibody-enhanced disease systemically. Our study reveals novel aspects of dengue pathogenesis and suggests that animal models of dengue and pre-clinical testing of dengue vaccines should consider mosquito-derived factors as well as enhancing antibodies. PMID:27310141

  9. Polymorphisms of the T cell receptor CD3delta and CD3varepsilon chains affect anti-CD3 antibody binding and T cell activation

    DEFF Research Database (Denmark)

    Boding, Lasse; Nielsen, Martin Weiss; Bonefeld, Charlotte Menné;

    2010-01-01

    suitable embryonic stem (ES) cell lines. Traditionally, ES cell lines from the 129 mouse strains have been used followed by backcrossing to the C57BL/6 strain. In the present study, we demonstrate the existence of polymorphisms in the CD3 genes from mice of the 129 and C57BL/6 strains. These polymorphisms...... CD3delta and varepsilon ectodomains exist in mice, and that some of these polymorphisms lead to amino acid substitutions which cause structural changes and affect anti-CD3 antibody binding. Thus, functional T cell studies should be interpreted with caution when anti-CD3 antibodies are used for......T cell receptor (TCR) structure and function have been thoroughly studied for decades. Production and analyses of knock-out and knock-in mice with mutations in the CD3 chains have contributed significantly to these studies. The generation of such gene-modified mice relies on the availability of...

  10. Proteomic Profiling of Recombinant Escherichia coli in High-Cell- Density Fermentations for Improved Production of an Antibody Fragment Biopharmaceutical

    OpenAIRE

    Aldor, Ilana S.; Krawitz, Denise C.; Forrest, William; Chen, Christina; Nishihara, Julie C.; Joly, John C.; Champion, Kathleen M.

    2005-01-01

    By using two-dimensional polyacrylamide gel electrophoresis, a proteomic analysis over time was conducted with high-cell-density, industrial, phosphate-limited Escherichia coli fermentations at the 10-liter scale. During production, a recombinant, humanized antibody fragment was secreted and assembled in a soluble form in the periplasm. E. coli protein changes associated with culture conditions were distinguished from protein changes associated with heterologous protein expression. Protein sp...

  11. Accumulation and toxicity of antibody-targeted doxorubicin-loaded PEG-PE micelles in ovarian cancer cell spheroid model

    OpenAIRE

    Perche, Federico; Torchilin, Vladimir P.

    2012-01-01

    We describe the evaluation of doxorubicin-loaded PEG-PE micelles targeting using an ovarian cancer cell spheroid model. Most ovarian cancer patients present at an advanced clinical stage and develop resistance to standard of care platinum/taxane therapy. Doxorubicin is also approved for ovarian cancer but had limited benefits in refractory patients. In this study, we used drug-resistant spheroid cultures of ovarian carcinoma to evaluate the uptake and cytotoxicity of an antibody-targeted doxo...

  12. Monoclonal immunoglobulin M antibody to Japanese encephalitis virus that can react with a nuclear antigen in mammalian cells.

    OpenAIRE

    Gould, E A; Chanas, A C; Buckley, A.; Clegg, C S

    1983-01-01

    An immunoglobulin M (IgM) class monoclonal antibody raised against Japanese encephalitis virus reacted with an epitope on the nonstructural virus protein P74 (NV4 in the old nomenclature) of several flaviviruses and also with an antigen present in the nuclei of a variety of mammalian cell types. This antigen had a characteristic granular distribution by immunofluorescence and may correspond to a polypeptide of molecular weight 56,000 seen in nitrocellulose transfers of sodium dodecyl sulfate-...

  13. Characterization and expression of the human T cell receptor-T3 complex by monoclonal antibody F101.01

    DEFF Research Database (Denmark)

    Geisler, C; Plesner, T; Pallesen, G; Skjødt, K; Ødum, Niels; Larsen, J K

    1988-01-01

    myeloid cells (CD13 and CD33) were excluded. The target antigen of F101.01 co-modulated with the CD3-defined antigen (T3) and the TCR recognized by the MoAb WT-31. CD3 antibody and WT-31 both blocked binding of F101.01. F101.01 precipitated the TCR-T3 complex from lysates of 125I-labelled peripheral blood...

  14. X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Evans, M K; Sauer, S J; Nath, S; Robinson, T J; Morse, M A; Devi, G R

    2016-01-01

    Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy. PMID:26821068

  15. Functional expression of a single-chain antibody to ErbB-2 in plants and cell-free systems

    OpenAIRE

    Benevolo Maria; Natali Pier; Martayan Aline; Fraioli Rocco; Tornambé Andrea; Sperandei Maria; Di Donato Monica; Novelli Flavia; Pietraforte Immacolata; Lombardi Alessio; Galeffi Patrizia; Mottolese Marcella; Ylera Francisco; Cantale Cristina; Giacomini Patrizio

    2006-01-01

    Abstract Background Aberrant signaling by ErbB-2 (HER 2, Neu), a member of the human Epidermal Growth Factor (EGF) receptor family, is associated with an aggressive clinical behaviour of carcinomas, particularly breast tumors. Antibodies targeting the ErbB-2 pathway are a preferred therapeutic option for patients with advanced breast cancer, but a worldwide deficit in the manufacturing capacities of mammalian cell bioreactors is foreseen. Methods Herein, we describe a multi-platform approach ...

  16. γ-Synuclein Antibodies Have Neuroprotective Potential on Neuroretinal Cells via Proteins of the Mitochondrial Apoptosis Pathway

    OpenAIRE

    Corina Wilding; Katharina Bell; Sabine Beck; Sebastian Funke; Norbert Pfeiffer; Grus, Franz H.

    2014-01-01

    The family of synuclein proteins (α, β and γ) are related to neurodegenerative disease e.g. Parkinson disease and Morbus Alzheimer. Additionally, a connection between γ-synuclein and glaucoma, a neurodegenerative disease characterized by a progressive loss of retinal ganglion cells, which finally leads to blindness, exists. The reason for the development of glaucoma is still unknown. Recent studies evaluating the participation of immunological components, demonstrate complex changed antibody ...

  17. CD45/CD8 myeloid histioid antigen and plasma cell antibody immune response in a case of malignant melanoma

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu-Velez

    2012-01-01

    Full Text Available The immune response in metastatic melanoma is not well established and therefore is of particular interest to test for recruitment of immune cells to the tumor. A 46-year-old Caucasian female was evaluated for an asymptomatic right forearm mass. The lesion had been present for at least 4 years and had become painful 4 months ago. Biopsies for hematoxylin and eosin (H and E staining, as well as immunohistochemical analysis were performed on the primary tumor and on sentinel lymph nodes. The H and E staining was consistent with metastatic melanoma. Positive staining was noted on the tumor cells with S-100, Mart-1/Melan A/CD63, PNL2, HMB45, and tyrosinase. Peritumoral and intratumoral inflammatory cells stained positive for CD8, CD45, PCNA, myeloid histoid antigen, antihuman plasma cell antibody, and focal BRCA1. The staining patterns of CD8/CD45, myeloid histoid antigen and plasma cell antibody on inflammatory cells around the melanoma cells suggest an unusual type of immune response.

  18. Natural killer cell cytotoxicity of breast cancer targets is enhanced by two distinct mechanisms of antibody-dependent cellular cytotoxicity against LFA-3 and HER2/neu.

    Science.gov (United States)

    Cooley, S; Burns, L J; Repka, T; Miller, J S

    1999-10-01

    Treatment of advanced breast cancer with autologous stem cell transplantation is limited by a high probability of disease relapse. In clinical trials, interleukin 2 (IL-2) alone can expand natural killer (NK) cells in vivo and increase their cytotoxic activity against breast cancer cell lines, but this increase is modest. Understanding the mechanisms that mediate NK cell lysis of breast cancer targets may lead to improvements of current immunotherapy strategies. NK cells from normal donors or patients receiving subcutaneous IL-2 were tested in cytotoxicity assays against five breast cancer cell lines. The role of adhesion molecules and antibodies that interact through Fc receptors on NK cells was explored. NK cell lysis of breast cancer targets is variable and is partially dependent on recognition through ICAM-1 and CD18. While blocking CD2 slightly decreased cytotoxicity, contrary to expectations, an antibody against CD58 (the ligand for CD2), failed to block killing and instead mediated an increased cytotoxicity that correlated with target density of CD58. The CD58 antibody-enhanced killing was dependent not only on FcRgammaIII but also on CD2 and ICAM-1/CD18. To further elucidate the mechanism of this CD58 antibody-dependent cellular cytotoxicity (ADCC), another antibody was tested. Trastuzumab (Herceptin), a humanized antibody against HER2/neu, mediated potent ADCC against all the HER2/neu positive breast cancer targets. Unlike CD58 antibody-mediated ADCC, Herceptin ADCC was minimally affected by blocking antibodies to CD2 or ICAM-1/CD18, which suggests a different mechanism of action. This study shows that multiple mechanisms are involved in NK cell lysis of breast cancer targets, that none of the targets are inherently resistant to killing, and that two distinct mechanisms of ADCC can target immunotherapy to breast cancer cells. PMID:10517495

  19. Cytotoxic activity against human neuroblastoma and melanoma cells mediated by IgM antibodies derived from peripheral blood of healthy donors.

    Science.gov (United States)

    Devarapu, Satish Kumar; Mamidi, Srinivas; Plöger, Frank; Dill, Othmar; Blixt, Ola; Kirschfink, Michael; Schwartz-Albiez, Reinhard

    2016-06-15

    A small percentage of healthy donors identified in the Western population carry antibodies in their peripheral blood which convey cytotoxic activity against certain human melanoma and neuroblastoma cell lines. We measured the cytotoxic activity of sera and plasmas from healthy donors on the human neuroblastoma cell line Kelly and various melanoma cell lines. Antibodies of IgM isotype, presumably belonging to the class of naturally occurring antibodies, exerted cytotoxic activity in a complement-dependent fashion. Apart from complement-dependent tumor cell lysis, we observed C3 opsonization in all tumor cell lines upon treatment with cytotoxic plasmas. Cell lines tested primarily expressed membrane complement regulatory proteins (mCRP) CD46, CD55 and CD59 to various extents. Blocking of mCRPs by monoclonal antibodies enhanced cell lysis and opsonization, though some melanoma cells remained resistant to complement attack. Epitopes recognized by cytotoxic antibodies were represented by gangliosides such as GD2 and GD3, as evidenced by cellular sialidase pretreatment and enhanced expression of distinct gangliosides. It remains to be clarified why only a small fraction of healthy persons carry these antitumor cytotoxic antibodies. PMID:26830059

  20. Altered immune response of immature dendritic cells following dengue virus infection in the presence of specific antibodies.

    Science.gov (United States)

    Torres, Silvia; Flipse, Jacky; Upasani, Vinit C; van der Ende-Metselaar, Heidi; Urcuqui-Inchima, Silvio; Smit, Jolanda M; Rodenhuis-Zybert, Izabela A

    2016-07-01

    Dengue virus (DENV) replication is known to prevent maturation of infected dendritic cells (DCs) thereby impeding the development of adequate immunity. During secondary DENV infection, dengue-specific antibodies can suppress DENV replication in immature DCs (immDCs), however how dengue-antibody complexes (DENV-IC) influence the phenotype of DCs remains elusive. Here, we evaluated the maturation state and cytokine profile of immDCs exposed to DENV-ICs. Indeed, DENV infection of immDCs in the absence of antibodies was hallmarked by blunted upregulation of CD83, CD86 and the major histocompatibility complex molecule HLA-DR. In contrast, DENV infection in the presence of neutralizing antibodies triggered full DC maturation and induced a balanced inflammatory cytokine response. Moreover, DENV infection under non-neutralizing conditions prompted upregulation of CD83 and CD86 but not HLA-DR, and triggered production of pro-inflammatory cytokines. The effect of DENV-IC was found to be dependent on the engagement of FcγRIIa. Altogether, our data show that the presence of DENV-IC alters the phenotype and cytokine profile of DCs. PMID:27121645

  1. Construction of cell surface-engineered yeasts displaying antigen to detect antibodies by immunofluorescence and yeast-ELISA.

    Science.gov (United States)

    Tang, Yu Qian; Han, Shuang Yan; Zheng, Hong; Wu, Lin; Ueda, Mitsuyoshi; Wang, Xiao Ning; Lin, Ying

    2008-07-01

    In order to detect monoclonal antibodies (MAbs) from insufficient and unavailable human proteins, yeast cells were engineered to display human antigens on their surface and consequently endowed with the ability to specifically bind antibodies. Thus, a fusion gene for the expression of the human proteasome subunit alpha 6 (hPSA6) and human profilin I (hProI) were assembled, respectively, with a His.tag marker at the C-terminal and displayed on yeast surface. With anti-His.tag MAb as the primary antibody and the fluorescein isothiocyanate-conjugated goat anti-mouse Immunoglobulin G as the second antibody, the surface display of hPSA6 and hProI were verified by immunofluorescence labeling. The antigen-displayed yeast particles were used for MAbs detection from ascites through both immunofluorescence and yeast-enzyme-linked immunosorbent assay (ELISA) methods. The results were verified by Western blotting and indirect ELISA. By improving the sensitivity, the novel MAbs detection can be applied in the generation and screening of positive hybridoma. It is suggested that by combining the DNA immunization, the present study can evolve into a quick and protein-free way of MAbs production for insufficient and unavailable antigen. PMID:18542951

  2. Production Of Human Antibodies

    Science.gov (United States)

    Sammons, David W.; Neil, Garry A.

    1993-01-01

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

  3. Immunogenic peptides comprising a T-helper epitope and a B-cell neutralizing antibody epitope

    Science.gov (United States)

    Haynes, Barton F.; Korber, Bette T.; De Lorimier, Robert M.

    2006-12-26

    The present invention relates, generally, to a polyvalent immunogen and, more particularly, to a method of inducing neutralizing antibodies against HIV and to a polyvalent immunogen suitable for use in such a method.

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  5. A suspected case of plasma cell-rich acute renal transplant rejection associated with de novo donor-specific antibody.

    Science.gov (United States)

    Yoshikawa, Mikiko; Kitamura, Ken; Ishimura, Takeshi; Hara, Shigeo; Fujisawa, Masato; Nishi, Shinichi

    2015-07-01

    A kidney transplant case with de novo donor-specific antibody showed monoclonal plasma cell infiltration into the graft with ABO incompatibility. Three years after transplantation, the patient's graft function suddenly deteriorated. Interstitial edema and the predominant infiltration of inflammatory plasma cells with kappa chain monoclonality were observed in biopsy specimens. The in situ hybridization of Epstein-Barr virus was negative and post-transplant lymphoproliferative disorder was not evident from radiological examinations. On laboratory examination, the patient had de novo donor-specific antibody for HLA-DQ. We suspected plasma cell-rich acute rejection for which methylprednisolone pulse therapy, plasma exchange, rituximab, and 15-deoxyspergualin were given. In the ensuing biopsy, the degree of plasma cell infiltration was similar to the first biopsy; however, kappa chain monoclonality relatively weakened. Owing to resistance to these treatments, intravenous immunoglobulin (IVIG) (0.5 g/kg/day) was added. The serum creatinine level gradually declined to 3.1 mg/dL; however, it increased up to 3.6 mg/dL again. In the final biopsy, the infiltrated plasma cells disappeared but severe interstitial fibrosis developed. This case showed difficulty in the diagnosis and treatment of plasma cell-rich acute rejection. A detailed consideration of this case may be helpful in understanding the clinical features and pathogenesis of this condition. PMID:26031590

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

    Science.gov (United States)

    Zhao, Xing-Chun; Wang, Le; Sun, Jing; Jiang, Bo-Wei; Zhang, Er-Li; Ye, Jian

    2016-01-01

    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. PMID:27442128

  7. A PAUF-neutralizing antibody targets both carcinoma and endothelial cells to impede pancreatic tumor progression and metastasis

    International Nuclear Information System (INIS)

    Highlights: • PMAb83, a human monoclonal antibody against PAUF, impaired tumor progression in vivo. • PMAb83 attenuated aggressiveness of tumor cells and suppressed angiogenesis. • PMAb83 in combination with gemcitabine conferred improved survival of mouse model. - Abstract: Pancreatic adenocarcinoma up-regulated factor (PAUF) is expressed in pancreatic ductal adenocarcinoma (PDAC) and plays an important role in tumor progression and metastasis. Here we evaluate the anti-tumor efficacy of a human monoclonal antibody against PAUF, PMAb83, to provide a therapeutic intervention to treat the disease. PMAb83 reduced tumor growth and distant metastasis in orthotopically xenografted mice of human PDAC cells. PMAb83 treatment retarded proliferation along with weakened aggressiveness traits of the carcinoma cells. AKT/β-catenin signaling played a role in the carcinoma cell proliferation and the treated xenograft tumors exhibited reduced levels of β-catenin and cyclin D1. Moreover PMAb83 abrogated the PAUF-induced angiogenic responses of endothelial cells, reducing the density of CD31+ vessels in the treated tumors. In combination with gemcitabine, PMAb83 conferred enhanced survival of xenografted mice by about twofold compared to gemcitabine alone. Taken together, our findings show that PMAb83 treatment decreases the aggressiveness of carcinoma cells and suppresses tumor vascularization, which culminates in mitigated tumor growth and metastasis with improved survival in PDAC mouse models

  8. A PAUF-neutralizing antibody targets both carcinoma and endothelial cells to impede pancreatic tumor progression and metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jin [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); New Drug Development Center, Osong Medical Innovation Foundation, Cheongwon, Chungbuk (Korea, Republic of); Chang, Suhwan [Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Lee, Yangsoon; Kim, Na Young; Hwang, Yeonsil; Min, Hye Jin; Yoo, Kyung-Sook; Park, Eun Hye; Kim, Seokho [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Chung, Young-Hwa [BK21-plus, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan (Korea, Republic of); Park, Young Woo [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Koh, Sang Seok, E-mail: sskoh@dau.ac.kr [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Department of Biological Sciences, Dong-A University, Busan (Korea, Republic of)

    2014-11-07

    Highlights: • PMAb83, a human monoclonal antibody against PAUF, impaired tumor progression in vivo. • PMAb83 attenuated aggressiveness of tumor cells and suppressed angiogenesis. • PMAb83 in combination with gemcitabine conferred improved survival of mouse model. - Abstract: Pancreatic adenocarcinoma up-regulated factor (PAUF) is expressed in pancreatic ductal adenocarcinoma (PDAC) and plays an important role in tumor progression and metastasis. Here we evaluate the anti-tumor efficacy of a human monoclonal antibody against PAUF, PMAb83, to provide a therapeutic intervention to treat the disease. PMAb83 reduced tumor growth and distant metastasis in orthotopically xenografted mice of human PDAC cells. PMAb83 treatment retarded proliferation along with weakened aggressiveness traits of the carcinoma cells. AKT/β-catenin signaling played a role in the carcinoma cell proliferation and the treated xenograft tumors exhibited reduced levels of β-catenin and cyclin D1. Moreover PMAb83 abrogated the PAUF-induced angiogenic responses of endothelial cells, reducing the density of CD31{sup +} vessels in the treated tumors. In combination with gemcitabine, PMAb83 conferred enhanced survival of xenografted mice by about twofold compared to gemcitabine alone. Taken together, our findings show that PMAb83 treatment decreases the aggressiveness of carcinoma cells and suppresses tumor vascularization, which culminates in mitigated tumor growth and metastasis with improved survival in PDAC mouse models.

  9. Analysis of memory B cell responses and isolation of novel monoclonal antibodies with neutralizing breadth from HIV-1-infected individuals.

    Directory of Open Access Journals (Sweden)

    Davide Corti

    Full Text Available BACKGROUND: The isolation of human monoclonal antibodies (mAbs that neutralize a broad spectrum of primary HIV-1 isolates and the characterization of the human neutralizing antibody B cell response to HIV-1 infection are important goals that are central to the design of an effective antibody-based vaccine. METHODS AND FINDINGS: We immortalized IgG(+ memory B cells from individuals infected with diverse clades of HIV-1 and selected on the basis of plasma neutralization profiles that were cross-clade and relatively potent. Culture supernatants were screened using various recombinant forms of the envelope glycoproteins (Env in multiple parallel assays. We isolated 58 mAbs that were mapped to different Env surfaces, most of which showed neutralizing activity. One mAb in particular (HJ16 specific for a novel epitope proximal to the CD4 binding site on gp120 selectively neutralized a multi-clade panel of Tier-2 HIV-1 pseudoviruses, and demonstrated reactivity that was comparable in breadth, but distinct in neutralization specificity, to that of the other CD4 binding site-specific neutralizing mAb b12. A second mAb (HGN194 bound a conserved epitope in the V3 crown and neutralized all Tier-1 and a proportion of Tier-2 pseudoviruses tested, irrespective of clade. A third mAb (HK20 with broad neutralizing activity, particularly as a Fab fragment, recognized a highly conserved epitope in the HR-1 region of gp41, but showed striking assay-dependent selectivity in its activity. CONCLUSIONS: This study reveals that by using appropriate screening methods, a large proportion of memory B cells can be isolated that produce mAbs with HIV-1 neutralizing activity. Three of these mAbs show unusual breadth of neutralization and therefore add to the current panel of HIV-1 neutralizing antibodies with potential for passive protection and template-based vaccine design.

  10. Consistent, multi-instrument single tube quantification of CD20 in antibody bound per cell based on CD4 reference.

    Science.gov (United States)

    Degheidy, Heba; Abbasi, Fatima; Mostowski, Howard; Gaigalas, Adolfas K; Marti, Gerald; Bauer, Steven; Wang, Lili

    2016-03-01

    Detecting changes in the expression levels of cell antigens could provide critical information for the diagnosis of many diseases, for example, leukemia, lymphoma, and immunodeficiency diseases, detecting minimal residual disease, monitoring immunotherapies and discovery of meaningful clinical disease markers. One of the most significant challenges in flow cytometry is how to best ensure measurement quality and generate consistent and reproducible inter-laboratory and intra-laboratory results across multiple cytometer platforms and locations longitudinally over time. In a previous study, we developed a procedure for instrument standardization across four different flow cytometer platforms from the same manufacturer. CD19 quantification was performed on three of the standardized instruments relative to CD4 expression on T lymphocytes with a known amount of antibody bound per cell (ABC) as a quantification standard. Consistent and reliable measures of CD19 expression were obtained independent of fluorochrome used demonstrating the utility of this approach. In the present investigation, quantification of CD20 relative to CD4 reference marker was implemented within a single tube containing both antibodies. Relative quantification of CD20 was performed using anti-CD20 antibody (clone L27) in three different fluorochromes relative to anti-CD4 antibody (clone SK3). Our results demonstrated that cell surface marker quantification can be performed robustly using the single tube assay format with novel gating strategies. The ABC values obtained for CD20 expression levels using PE, APC, or PerCP Cy5.5 are consistent over the five different instrument platforms for any given apparently healthy donor independent of the fluorochrome used. © 2015 International Clinical Cytometry Society. PMID:26013593

  11. Cytokine induction of VCAM-1 but not IL13Rα2 on glioma cells: a tale of two antibodies.

    Directory of Open Access Journals (Sweden)

    Vaidehi Mahadev

    Full Text Available The interleukin-13 receptor alpha2 (IL13Rα2 is a cell surface receptor that is over-expressed by a subset of high-grade gliomas, but not expressed at significant levels by normal brain tissue. For both malignant and non-malignant cells, IL13Rα2 surface expression is reported to be induced by various cytokines such as IL-4 or IL-13 and tumor necrosis factor (TNF. Our group has developed a therapeutic platform to target IL13Rα2-positive brain tumors by engineering human cytotoxic T lymphocytes (CTLs to express the IL13-zetakine chimeric antigen receptor. We therefore sought to investigate the potential of cytokine stimulation to induce IL13Rα2 cell surface expression, and thereby increase susceptibility to IL13Rα2-specific T cell killing. In the course of these experiments, we unexpectedly found that the commercially available putative IL13Rα2-specific monoclonal antibody B-D13 recognizes cytokine-induced VCAM-1 on glioblastoma. We provide evidence that the induced receptor is not IL13Rα2, because its expression does not consistently correlate with IL13Rα2 mRNA levels, it does not bind IL-13, and it is not recognized by IL13-zetakine CTL. Instead we demonstrate by immunoprecipitation experiments and mass spectrometry that the antigen recognized by the B-D13 antibody following cytokine stimulation is VCAM-1, and that VCAM-1, but not IL13Rα2, is induced on glioma cells by TNF alone or in combination with IL-13 or IL-4. Further evaluation of several commercial B-D13 antibodies revealed that B-D13 is bi-specific, recognizing both IL13Rα2 and VCAM-1. This binding is non-overlapping based on soluble receptor competition experiments, and mass spectrometry identifies two distinct heavy and light chain species, providing evidence that the B-D13 reagent is di-clonal. PE-conjugation of the B-D13 antibody appears to disrupt IL13Rα2 recognition, while maintaining VCAM-1 specificity. While this work calls into question previous studies that have used

  12. Mortalin antibody-conjugated quantum dot transfer from human mesenchymal stromal cells to breast cancer cells requires cell–cell interaction

    International Nuclear Information System (INIS)

    The role of tumor stroma in regulation of breast cancer growth has been widely studied. However, the details on the type of heterocellular cross-talk between stromal and breast cancer cells (BCCs) are still poorly known. In the present study, in order to investigate the intercellular communication between human mesenchymal stromal cells (hMSCs) and breast cancer cells (BCCs, MDA-MB-231), we recruited cell-internalizing quantum dots (i-QD) generated by conjugation of cell-internalizing anti-mortalin antibody and quantum dots (QD). Co-culture of illuminated and color-coded hMSCs (QD655) and BCCs (QD585) revealed the intercellular transfer of QD655 signal from hMSCs to BCCs. The amount of QD double positive BCCs increased gradually within 48 h of co-culture. We found prominent intercellular transfer of QD655 in hanging drop co-culture system and it was non-existent when hMSCs and BBCs cells were co-cultured in trans-well system lacking imminent cell–cell contact. Fluorescent and electron microscope analyses also supported that the direct cell-to-cell interactions may be required for the intercellular transfer of QD655 from hMSCs to BCCs. To the best of our knowledge, the study provides a first demonstration of transcellular crosstalk between stromal cells and BCCs that involve direct contact and may also include a transfer of mortalin, an anti-apoptotic and growth-promoting factor enriched in cancer cells

  13. Mortalin antibody-conjugated quantum dot transfer from human mesenchymal stromal cells to breast cancer cells requires cell–cell interaction

    Energy Technology Data Exchange (ETDEWEB)

    Pietilä, Mika [National Institute of Advanced industrial Sciences and Technology, Tsukuba, Ibaraki 305 8562 (Japan); Lehenkari, Petri [Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, Aapistie 7, P.O. Box 5000, FIN-90014 (Finland); Institute of Clinical Medicine, Division of Surgery, University of Oulu and Clinical Research Centre, Department of Surgery and Intensive Care, Oulu University Hospital, Aapistie 5a, P.O. Box 5000, FIN-90014 (Finland); Kuvaja, Paula [Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, Aapistie 7, P.O. Box 5000, FIN-90014 (Finland); Department of Pathology, Oulu University Hospital, P.O. Box 50, FIN-90029 OYS, Oulu (Finland); Kaakinen, Mika [Biocenter Oulu, University of Oulu, P.O. Box 5000, FI-90014 (Finland); Kaul, Sunil C.; Wadhwa, Renu [National Institute of Advanced industrial Sciences and Technology, Tsukuba, Ibaraki 305 8562 (Japan); Uemura, Toshimasa, E-mail: t.uemura@aist.go.jp [National Institute of Advanced industrial Sciences and Technology, Tsukuba, Ibaraki 305 8562 (Japan)

    2013-11-01

    The role of tumor stroma in regulation of breast cancer growth has been widely studied. However, the details on the type of heterocellular cross-talk between stromal and breast cancer cells (BCCs) are still poorly known. In the present study, in order to investigate the intercellular communication between human mesenchymal stromal cells (hMSCs) and breast cancer cells (BCCs, MDA-MB-231), we recruited cell-internalizing quantum dots (i-QD) generated by conjugation of cell-internalizing anti-mortalin antibody and quantum dots (QD). Co-culture of illuminated and color-coded hMSCs (QD655) and BCCs (QD585) revealed the intercellular transfer of QD655 signal from hMSCs to BCCs. The amount of QD double positive BCCs increased gradually within 48 h of co-culture. We found prominent intercellular transfer of QD655 in hanging drop co-culture system and it was non-existent when hMSCs and BBCs cells were co-cultured in trans-well system lacking imminent cell–cell contact. Fluorescent and electron microscope analyses also supported that the direct cell-to-cell interactions may be required for the intercellular transfer of QD655 from hMSCs to BCCs. To the best of our knowledge, the study provides a first demonstration of transcellular crosstalk between stromal cells and BCCs that involve direct contact and may also include a transfer of mortalin, an anti-apoptotic and growth-promoting factor enriched in cancer cells.

  14. Antibody responses to vaccination and immune function in patients with haematological malignancies - studies in patients with chronic lymphocytic leukaemia autologous stem cell recipients

    OpenAIRE

    Velden, A.M.T. van der

    2007-01-01

    This thesis concerns the antibody responses to vaccination and immune function of patients with several forms of haematological diseases. Antibody responses in patients with chronic lymphocytic leukaemia (CLL) and in autologous stem cell transplant recipients were studied. In the autologous stem cell transplantation (aSCT) group, immune reconstitution after aSCT was analysed in detail during 15 months following transplantation. The first part of the thesis concerns patients with chronic lymph...

  15. Localization at high resolution of antibody-induced mobilization of vaccinia virus hemagglutinin and the major histocompatibility antigens on the plasma membrane of infected cells

    OpenAIRE

    1982-01-01

    We examined the consequence of simultaneous or independent binding of monospecific antibody to the hemagglutinin (HA) of vaccinia virus and the A-, B- and -determinants of HLA on HeLa or Raji cells or KkDk determinants of H-2 on L929 cells. The bound antibodies were marked by goat-anti-mouse (GAM) or goat-anti-rabbit (GAR) fluorochrome conjugates suitable for light microscopy and GAM or GAR gold conjugates, used in electron microscopy. Specificity and amount of antibody adsorbed was ascertain...

  16. A combination of an anti-SLAMF6 antibody and ibrutinib efficiently abrogates expansion of chronic lymphocytic leukemia cells.

    Science.gov (United States)

    Yigit, Burcu; Halibozek, Peter J; Chen, Shih-Shih; O'Keeffe, Michael S; Arnason, Jon; Avigan, David; Gattei, Valter; Bhan, Atul; Cen, Osman; Longnecker, Richard; Chiorazzi, Nicholas; Wang, Ninghai; Engel, Pablo; Terhorst, Cox

    2016-05-01

    The signaling lymphocyte activation molecule family [SLAMF] of cell surface receptors partakes in both the development of several immunocyte lineages and innate and adaptive immune responses in humans and mice. For instance, the homophilic molecule SLAMF6 (CD352) is in part involved in natural killer T cell development, but also modulates T follicular helper cell and germinal B cell interactions. Here we report that upon transplantation of a well-defined aggressive murine B220+CD5+ Chronic Lymphocytic Leukemia (CLL) cell clone, TCL1-192, into SCID mice one injection of a monoclonal antibody directed against SLAMF6 (αSlamf6) abrogates tumor progression in the spleen, bone marrow and blood. Similarly, progression of a murine B cell lymphoma, LMP2A/λMyc, was also eliminated by αSlamf6. But, surprisingly, αSLAMF6 neither eliminated TCL1-192 nor LMP2A/λMyc cells, which resided in the peritoneal cavity or omentum. This appeared to be dependent upon the tumor environment, which affected the frequency of sub-populations of the TCL1-192 clone or the inability of peritoneal macrophages to induce Antibody Dependent Cellular Cytotoxicity (ADCC). However, co-administering αSlamf6 with the Bruton tyrosine kinase (Btk) inhibitor, ibrutinib, synergized to efficiently eliminate the tumor cells in the spleen, bone marrow, liver and the peritoneal cavity. Because an anti-human SLAMF6 mAb efficiently killed human CLL cells in vitro and in vivo, we propose that a combination of αSlamf6 with ibrutinib should be considered as a novel therapeutic approach for CLL and other B cell tumors. PMID:27029059

  17. 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)

    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 111In-labeled cMORF to direct targeting by 111In-labeled HPi1. Results: HPi1 binding to betalox5 human cells in the transplant was shown by immunofluorescence. Normal organ 111In 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.

  18. Impaired Epstein-Barr Virus-Specific Neutralizing Antibody Response during Acute Infectious Mononucleosis Is Coincident with Global B-Cell Dysfunction.

    Science.gov (United States)

    Panikkar, Archana; Smith, Corey; Hislop, Andrew; Tellam, Nick; Dasari, Vijayendra; Hogquist, Kristin A; Wykes, Michelle; Moss, Denis J; Rickinson, Alan; Balfour, Henry H; Khanna, Rajiv

    2015-09-01

    Here we present evidence for previously unappreciated B-cell immune dysregulation during acute Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM). Longitudinal analyses revealed that patients with acute IM have undetectable EBV-specific neutralizing antibodies and gp350-specific B-cell responses, which were associated with a significant reduction in memory B cells and no evidence of circulating antibody-secreting cells. These observations correlate with dysregulation of tumor necrosis factor family members BAFF and APRIL and increased expression of FAS on circulating B cells. PMID:26109734

  19. Depletion of T cell epitopes in lysostaphin mitigates anti-drug antibody response and enhances antibacterial efficacy in vivo

    Science.gov (United States)

    Zhao, Hongliang; Verma, Deeptak; Li, Wen; Choi, Yoonjoo; Ndong, Christian; Fiering, Steven N.; Bailey-Kellogg, Chris; Griswold, Karl E.

    2015-01-01

    SUMMARY The enzyme lysostaphin possesses potent anti-staphylococcal activity and represents a promising antibacterial drug candidate; however, its immunogenicity poses a barrier to clinical translation. Here, structure-based biomolecular design enabled widespread depletion of lysostaphin’s DRB1*0401 restricted T cell epitopes, and resulting deimmunized variants exhibited striking reductions in anti-drug antibody responses upon administration to humanized HLA-transgenic mice. This reduced immunogenicity translated into improved efficacy in the form of protection against repeated challenges with methicillin-resistant Staphylococcus aureus, or MRSA. In contrast, while wild type lysostaphin was efficacious against the initial MRSA infection, it failed to clear subsequent bacterial challenges that were coincident with escalating anti-drug antibody titers. These results extend the existing deimmunization literature, in which reduced immunogenicity and retained efficacy are assessed independently of each other. By correlating in vivo efficacy with longitudinal measures of anti-drug antibody development, we provide the first direct evidence that T cell epitope depletion manifests enhanced biotherapeutic efficacy. PMID:26000749

  20. Assessment of 188Re marked anti MHC class Ⅱ antibody by peripheral blood mononuclear cells stimulated by donor alloantigen

    Institute of Scientific and Technical Information of China (English)

    DING Guo-ping; CAO Li-ping; LIU Jie; LIU Da-ren; QUE Ri-sheng; ZHU Lin-hua; ZHOU Yi-ming; MAO Ke-jie; HU Jun-an

    2011-01-01

    Background Previous studies showed that anti MHC-Ⅱ monoclone antibody (MAb) only had partial inhibiting effect of alloreactive mixed lymphocyte reaction (MLR) in vitro and it was unsteady and non-persistent. The aim of this research was to determine whether radioactive isotope 188Re marked MHC-Ⅱ antibody could benefit the allograft acceptance in transplantation as compared to normal MHC-Ⅱ antibody.Methods 188Re was incorporated to 2E9/13F(ab')2 which is against swine MHC class Ⅱ antigen (MAb-188Re). Porcine peripheral blood mononuclear (PBMC) cells were examined for proliferation and cytokine mRNA expression after stimulation with MHC-Ⅱ MAb or MAb-188Re.Results The proliferative response of recipient PBMCs in mixed lymphocyte reaction (MLR) to donor alloantigen showed that the stimulation index of MAb-188Re group was significantly lower than the MHC-Ⅱ MAb group and control (P<0.05). mRNA expression of interleukin 2, interferon Y and tumor necrosis factor α (type 1 cytokines) was lower in MAb-188Re group than the MHC-Ⅱ MAb group, while interleukin 10 (type 2 cytokines) was higher in MAb-188Re group in the first 24 hours.Conclusion MAb-188Re could help the graft acceptance by inhibiting T cell proliferation, lowering the expression of type 1 cytokines and elevating the type 2 cytokines produced by PBMC.

  1. Target-selective homologous recombination cloning for high-throughput generation of monoclonal antibodies from single plasma cells

    Directory of Open Access Journals (Sweden)

    Isobe Masaharu

    2011-04-01

    Full Text Available Abstract Background Molecular cloning of functional immunoglobulin genes from single plasma cells is one of the most promising technologies for the rapid development of monoclonal antibody drugs. However, the proper insertion of PCR-amplified immunoglobulin genes into expression vectors remains an obstacle to the high-throughput production of recombinant monoclonal antibodies. Results We developed a single-step cloning method, target-selective homologous recombination (TS-HR, in which PCR-amplified immunoglobulin variable genes were selectively inserted into vectors, even in the presence of nonspecifically amplified DNA. TS-HR utilizes Red/ET-mediated homologous recombination with a target-selective vector (TS-vector with unique homology arms on its termini. Using TS-HR, immunoglobulin variable genes were cloned directly into expression vectors by co-transforming unpurified PCR products and the TS-vector into E. coli. Furthermore, the high cloning specificity of TS-HR allowed plasmids to be extracted from pools of transformed bacteria without screening single colonies for correct clones. We present a one-week protocol for the production of recombinant mouse monoclonal antibodies from large numbers of single plasma cells. Conclusion The time requirements and limitations of traditional cloning procedures for the production of recombinant immunoglobulins have been significantly reduced with the development of the TS-HR cloning technique.

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

    Science.gov (United States)

    Strohl, William R

    2014-03-01

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

  3. Anti-β2GPI antibodies stimulate endothelial cell microparticle release via a nonmuscle myosin II motor protein-dependent pathway.

    Science.gov (United States)

    Betapudi, Venkaiah; Lominadze, George; Hsi, Linda; Willard, Belinda; Wu, Meifang; McCrae, Keith R

    2013-11-28

    The antiphospholipid syndrome is characterized by thrombosis and recurrent fetal loss in patients with antiphospholipid antibodies (APLAs). Most pathogenic APLAs are directed against β2-glycoprotein I (β2GPI), a plasma phospholipid binding protein. One mechanism by which circulating antiphospholipid/anti-β2GPI antibodies may promote thrombosis is by inducing the release of procoagulant microparticles from endothelial cells. However, there is no information available concerning the mechanisms by which anti-β2GPI antibodies induce microparticle release. In seeking to identify proteins phosphorylated during anti-β2GPI antibody-induced endothelial activation, we observed phosphorylation of nonmuscle myosin II regulatory light chain (RLC), which regulates cytoskeletal assembly. In parallel, we observed a dramatic increase in the formation of filamentous actin, a two- to fivefold increase in the release of endothelial cell microparticles, and a 10- to 15-fold increase in the expression of E-selectin, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and tissue factor messenger RNA. Microparticle release, but not endothelial cell surface E-selectin expression, was blocked by inhibiting RLC phosphorylation or nonmuscle myosin II motor activity. These results suggest that distinct pathways, some of which mediate cytoskeletal assembly, regulate the endothelial cell response to anti-β2GPI antibodies. Inhibition of nonmuscle myosin II activation may provide a novel approach for inhibiting microparticle release by endothelial cells in response to anti-β2GPI antibodies. PMID:23954892

  4. A cytotoxic humanized anti-ganglioside antibody produced in a murine cell line defective of N-glycolylated-glycoconjugates.

    Science.gov (United States)

    Fernández-Marrero, Yuniel; Roque-Navarro, Lourdes; Hernández, Tays; Dorvignit, Denise; Molina-Pérez, Marively; González, Addys; Sosa, Katya; López-Requena, Alejandro; Pérez, Rolando; de Acosta, Cristina Mateo

    2011-12-01

    Gangliosides containing the N-glycolyl (NGc) form of sialic acid are tumor-associated antigens and promising candidates for cancer therapy. We previously generated the murine 14F7 monoclonal antibody (mAb), specific for the N-glycolyl-GM3 ganglioside (NGcGM3), which induced an oncosis-like type of cell death on malignant cell lines expressing this antigen and recognized breast carcinoma by immunoscintigraphy in cancer patients. As humanization is expected to enhance its use for human cancer therapy, herein we describe the design and generation of two humanized versions of the 14F7 mAb by disrupting potential human T cell epitopes on its variable region. No differences in antigen reactivity or cytotoxic properties were detected among the variants tested and with respect to the chimeric counterpart. Humanized 14F7 genes were transfected into the NGcGM3-expressing NS0 cell line. Therefore, in the industrial scaling-up of the transfectoma in serum-free medium, cell viability was lost due to the cytotoxic effect of the secreted antibody. This shortcoming was solved by knocking down the CMP-N-acetylneuraminic acid hydroxylase enzyme, thus impairing the synthesis of NGc-glycoconjugates. Humanized 14F7 mAb is of potential value for the therapy of NGcGM3-expressing tumors. PMID:21802167

  5. Protective antibody and CD8+ T-cell responses to the Plasmodium falciparum circumsporozoite protein induced by a nanoparticle vaccine.

    Directory of Open Access Journals (Sweden)

    Stephen A Kaba

    Full Text Available BACKGROUND: The worldwide burden of malaria remains a major public health problem due, in part, to the lack of an effective vaccine against the Plasmodium falciparum parasite. An effective vaccine will most likely require the induction of antigen specific CD8(+ and CD4(+ T-cells as well as long-lasting antibody responses all working in concert to eliminate the infection. We report here the effective modification of a self-assembling protein nanoparticle (SAPN vaccine previously proven effective in control of a P. berghei infection in a rodent model to now present B- and T-cell epitopes of the human malaria parasite P. falciparum in a platform capable of being used in human subjects. METHODOLOGY/PRINCIPAL FINDINGS: To establish the basis for a SAPN-based vaccine, B- and CD8(+ T-cell epitopes from the P. falciparum circumsporozoite protein (PfCSP and the universal CD4 T-helper epitope PADRE were engineered into a versatile small protein (∼125 amino acids that self-assembles into a spherical nanoparticle repetitively displaying the selected epitopes. P. falciparum epitope specific immune responses were evaluated in mice using a transgenic P. berghei malaria parasite of mice expressing the human malaria full-length P. falciparum circumsporozoite protein (Tg-Pb/PfCSP. We show that SAPN constructs, delivered in saline, can induce high-titer, long-lasting (1 year protective antibody and poly-functional (IFNγ(+, IL-2(+ long-lived central memory CD8(+ T-cells. Furthermore, we demonstrated that these Ab or CD8(+ T-cells can independently provide sterile protection against a lethal challenge of the transgenic parasites. CONCLUSION: The SAPN construct induces long-lasting antibody and cellular immune responses to epitope specific sequences of the P. falciparum circumsporozoite protein (PfCSP and prevents infection in mice by a transgenic P. berghei parasite displaying the full length PfCSP.

  6. A function-blocking CD47 antibody suppresses stem cell and EGF signaling in triple-negative breast cancer

    Science.gov (United States)

    Kaur, Sukhbir; Elkahloun, Abdel G.; Singh, Satya P.; Chen, Qing-Rong; Meerzaman, Daoud M.; Song, Timothy; Manu, Nidhi; Wu, Weiwei; Mannan, Poonam; Garfield, Susan H.; Roberts, David D.

    2016-01-01

    CD47 is a signaling receptor for thrombospondin-1 and the counter-receptor for signal-regulatory protein-α (SIRPα). By inducing inhibitory SIRPα signaling, elevated CD47 expression by some cancers prevents macrophage phagocytosis. The anti-human CD47 antibody B6H12 inhibits tumor growth in several xenograft models, presumably by preventing SIRPα engagement. However, CD47 signaling in nontransformed and some malignant cells regulates self-renewal, suggesting that CD47 antibodies may therapeutically target cancer stem cells (CSCs). Treatment of MDA-MB-231 breast CSCs with B6H12 decreased proliferation and asymmetric cell division. Similar effects were observed in T47D CSCs but not in MCF7 breast carcinoma or MCF10A breast epithelial cells. Gene expression analysis in breast CSCs treated with B6H12 showed decreased expression of epidermal growth factor receptor (EGFR) and the stem cell transcription factor KLF4. EGFR and KLF4 mRNAs are known targets of microRNA-7, and B6H12 treatment correspondingly enhanced microRNA-7 expression in breast CSCs. B6H12 treatment also acutely inhibited EGF-induced EGFR tyrosine phosphorylation. Expression of B6H12-responsive genes correlated with CD47 mRNA expression in human breast cancers, suggesting that the CD47 signaling pathways identified in breast CSCs are functional in vivo. These data reveal a novel SIRPα-independent mechanism by which therapeutic CD47 antibodies could control tumor growth by autonomously forcing differentiation of CSC. PMID:26840086

  7. Targeting Prostate Cancer Cells In Vivo Using a Rapidly Internalizing Novel Human Single-Chain Antibody Fragment

    Science.gov (United States)

    He, Jiang; Wang, Yong; Feng, Jinjin; Zhu, Xiaodong; Lan, Xiaoli; Iyer, Arun K.; Zhang, Niu; Seo, Youngho; VanBrocklin, Henry F.; Liu, Bin

    2010-01-01

    Human antibodies targeting prostate cancer cell surface epitopes may be useful for imaging and therapy. The objective of this study was to evaluate the tumor targeting of an internalizing human antibody fragment, a small-size platform, to provide high contrast in a mouse model of human prostate carcinoma. Methods A prostate tumor-targeting single-chain antibody fragment (scFv), UA20, along with a nonbinding control scFv, N3M2, were labeled with 99mTc and evaluated for binding and rapid internalization into human prostate tumor cells in vitro and tumor homing in vivo using xenograft models. For the in vitro studies, the labeled UA20 scFv was incubated at 37°C for 1 h with metastatic prostate cancer cells (DU145) to assess the total cellular uptake versus intracellular uptake. For the animal studies, labeled UA20 and N3M2 scFvs were administered to athymic mice implanted subcutaneously with DU145 cells. Mice were imaged with small-animal SPECT/CT with concomitant biodistribution at 1 and 3 h after injection. Results The UA20 scFv was labeled in 55%–65% yield and remained stable in phosphate buffer within 24 h. The labeled UA20 scFv was taken up specifically by prostate tumor cells. Internalization was rapid, because incubation at 37°C for less than 1 h resulted in 93% internalization of total cell-associated scFvs. In animal studies, SPECT/CT showed significant tumor uptake as early as 1 h after injection. At 3 h after injection, tumor uptake was 4.4 percentage injected dose per gram (%ID/g), significantly greater than all organs or tissues studied (liver, 2.7 %ID/g; other organs or tissues, <1 %ID/g), except the kidneys (81.4 %ID/g), giving tumor-to-blood and tumor-to-muscle ratios of 12:1 and 70:1, respectively. In contrast, the control antibody exhibited a tumor uptake of only 0.26 %ID/g, similar to that of muscle and fat. Tumor-specific targeting was evidenced by reduced tumor uptake of nearly 70% on administration of a 10-fold excess of unlabeled UA20 sc

  8. Progression to type 1 diabetes in islet cell antibody-positive relatives in the European Nicotinamide Diabetes Intervention Trial

    DEFF Research Database (Denmark)

    Bingley, P J; Gale, E A M; Reimers, Jesper Irving

    2006-01-01

    AIMS/HYPOTHESIS: To examine the role of additional immune, genetic and metabolic risk markers in determining risk of diabetes in islet cell antibody (ICA)-positive individuals with a family history of type 1 diabetes recruited into the European Nicotinamide Diabetes Intervention Trial. METHODS......: Five hundred and forty-nine first-degree relatives with confirmed ICA levels > or =20 Juvenile Diabetes Foundation units (mean age 15.9 years; interquartile range 10.4-33.7 years) were recruited from 20 countries. OGTTs and IVGTTs were performed at baseline, antibodies to glutamate decarboxylase (GADA......), protein tyrosine phosphatase (IA-2A) and insulin (IAA) were determined by RIA, and HLA class II genotyping was performed by PCR of sequence-specific oligonucleotides. RESULTS: One hundred and fifty-nine participants developed diabetes within 5 years. Univariate analysis showed that the cumulative risk of...

  9. ACE inhibitors can induce circulating antibodies directed to antigens of the superficial epidermal cells.

    Science.gov (United States)

    Cozzani, Emanuele; Rosa, Gian Marco; Drosera, Massimo; Intra, Chiara; Barsotti, Antonio; Parodi, Aurora

    2011-07-01

    Drug-induced pemphigus has been reported in patients receiving angiotensin-converting enzyme inhibitors. The aim of this work was to study a group of hypertensive patients without skin diseases treated with angiotensin-converting enzyme (ACE) Inhibitors (I), to verify the presence of serum circulating anti-antibodies. The indirect immunofluorescence showed that 33 sera (52.38%) presented autoantibodies directed to an antigen of the cytoplasm of the superficial epidermal keratinocytes. Two of the 33 positive sera had antibodies to Dsg1 and/or 3 in ELISA. Immunoblot analyses were negative. All the 48 control sera were found to have no circulating antibodies using the three assays. Our results would confirm that ACEI drugs may trigger the production of circulating autoantibodies also in patients without clinical manifestations of pemphigus. PMID:20563876

  10. Antibody-based screening of cell wall matrix glycans in ferns reveals taxon, tissue and cell-type specific distribution patterns

    DEFF Research Database (Denmark)

    Leroux, Olivier; Sørensen, Iben; Marcus, Susan E.;

    2015-01-01

    Background: While it is kno3wn that complex tissues with specialized functions emerged during land plant evolution, it is not clear how cell wall polymers and their structural variants are associated with specific tissues or cell types. Moreover, due to the economic importance of many flowering...... plants, ferns have been largely neglected in cell wall comparative studies. Results: To explore fern cell wall diversity sets of monoclonal antibodies directed to matrix glycans of angiosperm cell walls have been used in glycan microarray and in situ analyses with 76 fern species and four species of...... across the ferns and specifically associated with phloem cell walls and similarly the LM11 xylan epitope was associated with xylem cell walls. The LM5 galactan and LM6 arabinan epitopes, linked to pectic supramolecules in angiosperms, were associated with vascular structures with only limited detection...

  11. Large-scale analysis of B-cell epitopes on influenza virus hemagglutinin - implications for cross-reactivity of neutralizing antibodies

    Directory of Open Access Journals (Sweden)

    Jing eSun

    2014-02-01

    Full Text Available Influenza viruses continue to cause substantial morbidity and mortality worldwide. Fast gene mutation on surface proteins of influenza virus result in increasing resistance to current vaccines and available antiviral drugs. Broadly neutralizing antibodies represent targets for prophylactic and therapeutic treatments of influenza. We performed a systematic bioinformatics study of cross-reactivity of neutralizing antibodies against influenza virus surface glycoprotein hemagglutinin (HA. This study utilized the available crystal structures of HA complexed with the antibodies for the analysis of tens of thousands of HA sequences. The detailed description of B-cell epitopes, measurement of epitope area similarity among different strains, and estimation of antibody neutralizing coverage provide insights into cross-reactivity status of existing neutralizing antibodies against influenza virus. We have developed a method to assess the likely cross-reactivity potential of broadly neutralizing antibodies for influenza strains, either newly emerged or existing. Our method catalogs influenza strains by a new concept named discontinuous peptide, and then provide assessment of cross-reactivity. Potentially cross-reactive strains are those that share 100% identity with experimentally verified neutralized strains. By cataloging influenza strains and their B-cell epitopes for known broadly neutralizing antibodies, our method provides guidance for selection of representative strains for further experimental design. The knowledge of sequences, their B-cell epitopes, and differences between historical influenza strains, we enhance our preparedness and the ability to respond to the emerging pandemic threats.

  12. Anti-S100A4 Antibody Suppresses Metastasis Formation by Blocking Stroma Cell Invasion

    OpenAIRE

    Jörg Klingelhöfer; Birgitte Grum-Schwensen; Beck, Mette K.; Rikke Stagaard Petersen Knudsen; Mariam Grigorian; Eugene Lukanidin; Noona Ambartsumian

    2012-01-01

    The small Ca-binding protein, S100A4, has a well-established metastasis-promoting activity. Moreover, its expression is tightly correlated with poor prognosis in patients with numerous types of cancer. Mechanistically, the extracellular S100A4 drives metastasis by affecting the tumor 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 si...

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

    OpenAIRE

    Hanan Fallouh; Wahib Mahana

    2012-01-01

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

  14. 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.

  15. Detection of DNA damage in cells exposed to ionizing radiation by use of antisingle-stranded-DNA monoclonal antibody

    International Nuclear Information System (INIS)

    An immunochemical method has been developed for quantitative detection of DNA damage in mammalian cells. The method is based on the binding of a monoclonal antibody to single-stranded DNA. The clone producing this antibody, D1B, was obtained as a by-product from fusion of mouse myeloma cells with spleen cells isolated from a mouse immunized with chemically modified DNA. The technique is based upon the determination of the percentage single-strandedness resulting from the partial umwinding of cellular DNA under alkaline conditions, a time-dependent process. Single-strand and double-strand DNA breaks, or lesions converted into such breaks in alkaline medium, form initiation points for the unwinding. The extent of unwinding under controlled conditions is a measure, therefore, of the amount of such sites. The method is rapid, does not require radioactive labelling of DNA or physical separation of single- from double-stranded molecules, is sufficiently sensitive to detect damage induced by 1 Gu of ionizing radiation and needs only small amounts of cells. The usefulness of the technique was demonstrated in a study on the induction of damage and its repair in unlabelled cultured Chinese hamster cells and in DNA-containing cells of human blood, both after exposure to 60Co-γ-rays, and in white blood cells and bone marrow cells of X-irradiated mice. A dose-related degree of unwinding was observed and repair could be observed up to 60 min after irradiation. (author). 19 refs.; 3 figs.; 1 tab

  16. Site-Directed Conjugation of Antibodies to Apoferritin Nanocarrier for Targeted Drug Delivery to Prostate Cancer Cells.

    Science.gov (United States)

    Dostalova, Simona; Cerna, Tereza; Hynek, David; Koudelkova, Zuzana; Vaculovic, Tomas; Kopel, Pavel; Hrabeta, Jan; Heger, Zbynek; Vaculovicova, Marketa; Eckschlager, Tomas; Stiborova, Marie; Adam, Vojtech

    2016-06-15

    Herein, we describe a novel approach for targeting of ubiquitous protein apoferritin (APO)-encapsulating doxorubicin (DOX) to prostate cancer using antibodies against prostate-specific membrane antigen (PSMA). The conjugation of anti-PSMA antibodies and APO was carried out using HWRGWVC heptapeptide, providing their site-directed orientation. The prostate-cancer-targeted and nontargeted nanocarriers were tested using LNCaP and HUVEC cell lines. A total of 90% of LNCaP cells died after treatment with DOX (0.25 μM) or DOX in nontargeted and prostate-cancer-targeted APO, proving that the encapsulated DOX toxicity for LNCaP cells remained the same. Free DOX showed higher toxicity for nonmalignant cells, whereas the toxicity was lower after treatment with the same dosage of APO-encapsulated DOX (APODOX) and even more in prostate-cancer-targeted APODOX. Hemolytic assay revealed exceptional hemocompatibility of the entire nanocarrier. The APO encapsulation mechanism ensures applicability using a wide variety of chemotherapeutic drugs, and the presented surface modification enables targeting to various tumors. PMID:27219717

  17. Serum ferritin in patients with cancer: determination with antibodies to HeLa cell and spleen ferritin

    International Nuclear Information System (INIS)

    Some malignant tissues and cell lines contain acidic isoferritins and it has been suggested that the assay of such isoferritins in serum may be of value in the diagnosis of malignancy. This paper describes a radioimmunoassay for acidic ferritin purified from HeLa cells. Examination of purified heart, kidney, liver and spleen ferritin showed that the assay was highly specific for acidic isoferritins. Ferritin concentrations have been measured with antibodies to HeLa cell and spleen ferritin in extracts of normal and tumour tissue. Although the tumours contained more HeLa type ferritin than the corresponding normal tissue the HeLa/spleen type ferritin ratio was low. HeLa-type ferritin concentrations have been compared with values obtained with anti-spleen ferritin in over 1000 sera from normal subjects and patients with cancer and leukaemia. HeLa-type ferritin was not detected (<2 μg/l) in most normal sera. Concentrations of up to 53 μg/l were found in sera from patients with malignant disease but the HeLa/spleen type ferritin ratio was always very low. There appears to be little application for antibodies to HeLa cell or heart ferritin in the diagnosis or monitoring of cancer. (Auth.)

  18. Separation of effector cells mediating antibody-dependent cellular cytotoxicity (ADC) to erythrocyte targets from those mediating ADC to tumor targets.

    Science.gov (United States)

    Pollack, S B; Nelson, K; Grausz, J D

    1976-04-01

    Murine spleen cells mediate antibody-dependent cellular cytotoxicity (ADC) both to erythrocyte targets in a 51Cr release assay and to syngeneic tumor targets in a microcytotoxicity assay. The effector cells active in the two ADC assays can be separated by passage of the spleen cells through columns of Sephadex G-10 at 37 degrees C. Cells mediating ADC to sarcoma cells did not adhere to the G-10 and were recovered in the column effluent. These nonadherent cells were not cytotoxic to antibody-coated chicken red blood cells. Spleen cells which mediated ADC in a 51Cr release assay to the red cell targets adhered to G-10. Adherent effector cells could subsequently be recovered from the columns by elution with 5 X 10(-4) M EDTA. PMID:815438

  19. High-throughput screening of monoclonal antibodies against plant cell wall glycans by hierarchical clustering of their carbohydrate microarray binding profiles

    DEFF Research Database (Denmark)

    Moller, Isabel; Marcus, Susan E.; Haeger, Ash;

    2007-01-01

    Antibody-producing hybridoma cell lines were created following immunisation with a crude extract of cell wall polymers from the plant Arabidopsis thaliana. In order to rapidly screen the specificities of individual monoclonal antibodies (mAbs), their binding to microarrays containing 50 cell wall...... investigated using subsequent immunochemical and biochemical analyses and two novel mAbs are described in detail. mAb LM13 binds to an arabinanase-sensitive pectic epitope and mAb LM14, binds to an epitope occurring on arabinogalactan-proteins. Both mAbs display novel patterns of recognition of cell walls in...... plant materials....

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

    Directory of Open Access Journals (Sweden)

    Andrabi Raiees

    2012-09-01

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

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

    DEFF Research Database (Denmark)

    Tsimikas, Sotirios; Miyanohara, Atsushi; Hartvigsen, Karsten; Merki, Esther; Shaw, Peter X; Chou, Meng-Yun; Pattison, Jennifer; Torzewski, Michael; Sollors, Janina; Friedmann, Theodore; Lai, N Chin; Hammond, H Kirk; Getz, Godfrey S; Reardon, Catherine A; Li, Andrew C; Banka, Carole L; Witztum, Joseph L

    2011-01-01

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

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

    OpenAIRE

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

    1986-01-01

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

  3. Label-free capture of breast cancer cells spiked in buffy coats using carbon nanotube antibody micro-arrays

    Science.gov (United States)

    Khosravi, Farhad; Trainor, Patrick; Rai, Shesh N.; Kloecker, Goetz; Wickstrom, Eric; Panchapakesan, Balaji

    2016-04-01

    We demonstrate the rapid and label-free capture of breast cancer cells spiked in buffy coats using nanotube-antibody micro-arrays. Single wall carbon nanotube arrays were manufactured using photo-lithography, metal deposition, and etching techniques. Anti-epithelial cell adhesion molecule (EpCAM) antibodies were functionalized to the surface of the nanotube devices using 1-pyrene-butanoic acid succinimidyl ester functionalization method. Following functionalization, plain buffy coat and MCF7 cell spiked buffy coats were adsorbed on to the nanotube device and electrical signatures were recorded for differences in interaction between samples. A statistical classifier for the ‘liquid biopsy’ was developed to create a predictive model based on dynamic time warping to classify device electrical signals that corresponded to plain (control) or spiked buffy coats (case). In training test, the device electrical signals originating from buffy versus spiked buffy samples were classified with ˜100% sensitivity, ˜91% specificity and ˜96% accuracy. In the blinded test, the signals were classified with ˜91% sensitivity, ˜82% specificity and ˜86% accuracy. A heatmap was generated to visually capture the relationship between electrical signatures and the sample condition. Confocal microscopic analysis of devices that were classified as spiked buffy coats based on their electrical signatures confirmed the presence of cancer cells, their attachment to the device and overexpression of EpCAM receptors. The cell numbers were counted to be ˜1-17 cells per 5 μl per device suggesting single cell sensitivity in spiked buffy coats that is scalable to higher volumes using the micro-arrays.

  4. A Cytotoxic Antibody Recognizing Lacto-N-fucopentaose I (LNFP I) on Human Induced Pluripotent Stem (hiPS) Cells.

    Science.gov (United States)

    Matsumoto, Shogo; Nakao, Hiromi; Kawabe, Keiko; Nonaka, Motohiro; Toyoda, Hidenao; Takishima, Yuto; Kawabata, Kenji; Yamaguchi, Tomoko; Furue, Miho K; Taki, Takao; Okumura, Takeshi; Yamazaki, Yuzo; Nakaya, Shuuichi; Kawasaki, Nobuko; Kawasaki, Toshisuke

    2015-08-14

    We have generated a mouse monoclonal antibody (R-17F, IgG1 subtype) specific to human induced pluripotent stem (hiPS)/embryonic stem (ES) cells by using a hiPS cell line as an antigen. Triple-color confocal immunostaining images of hiPS cells with R-17F indicated that the R-17F epitope was expressed exclusively and intensively on the cell membranes of hiPS cells and co-localized partially with those of SSEA-4 and SSEA-3. Lines of evidence suggested that the predominant part of the R-17F epitope was a glycolipid. Upon TLC blot of total lipid extracts from hiPS cells with R-17F, one major R-17F-positive band was observed at a slow migration position close to that of anti-blood group H1(O) antigen. MALDI-TOF-MS and MS(n) analyses of the purified antigen indicated that the presumptive structure of the R-17F antigen was Fuc-Hex-HexNAc-Hex-Hex-Cer. Glycan microarray analysis involving 13 different synthetic oligosaccharides indicated that R-17F bound selectively to LNFP I (Fucα1-2Galβ1-3GlcNAcβ1-3Galβ1-4Glc). A critical role of the terminal Fucα1-2 residue was confirmed by the selective disappearance of R-17F binding to the purified antigen upon α1-2 fucosidase digestion. Most interestingly, R-17F, when added to hiPS/ES cell suspensions, exhibited potent dose-dependent cytotoxicity. The cytotoxic effect was augmented markedly upon the addition of the secondary antibody (goat anti-mouse IgG1 antibody). R-17F may be beneficial for safer regenerative medicine by eliminating residual undifferentiated hiPS cells in hiPS-derived regenerative tissues, which are considered to be a strong risk factor for carcinogenesis. PMID:26100630

  5. Primary Immunization with a Triple Diphtheria-Tetanus-Whole Cell Pertussis Vaccine in Iranian Infants: An Analysis of Antibody Response

    Directory of Open Access Journals (Sweden)

    Zarei Saeed

    2009-06-01

    Full Text Available Universal vaccination of neonates and children against diphtheria, tetanus and pertussis has had a tremendous impact on the control of these infectious diseases worldwide. Immunization by the triple diphtheria, tetanus and whole cell pertussis vaccine (DTwP has been applied in Iran for almost 50 years. Periodic assessment of immunogenicity of this vaccine is an important aspect of successful mass vaccination programs. The present study was performed to assess the antibody response against tetanus, diphtheria and pertussis in a group of Iranian infants vaccinated with a local DTwP vaccine. In this prospective study, 330 infants received primary vaccination at 2, 4 and 6 months of age with DTwP vaccine manufactured by Razi Institute of Iran. Blood samples were taken 2-4 weeks after the third dose to assess seroprotection and geometric mean titers (GMT of specific antibodies. Among the 283 infants who completed the vaccination course, 98.2% and 100% developed antibodies against diphtheria and tetanus, respectively. The GMT of antibodies to tetanus, diphtheria and pertussis, were 2.09 IU/ml, 2.08 IU/ml and 8.73 EU/ml, respectively. Comparison of the results obtained from this study with those from previous studies performed in other countries revealed a similar GMT and protection rates for diphtheria and tetanus components. In the absence of well-established serological criteria, judgment about protection rate against pertussis has not been possible. A prospective vaccination study using the local DTwP vaccine in parallel to a WHO approved standard vaccine, could enable assessment of immunogenicity of the pertussis component.

  6. B Cell, Th17, and Neutrophil Related Cerebrospinal Fluid Cytokine/Chemokines Are Elevated in MOG Antibody Associated Demyelination

    Science.gov (United States)

    Kothur, Kavitha; Wienholt, Louise; Tantsis, Esther M; Earl, John; Bandodkar, Sushil; Prelog, Kristina; Tea, Fiona; Ramanathan, Sudarshini; Brilot, Fabienne; Dale, Russell C.

    2016-01-01

    Background Myelin oligodendrocyte glycoprotein antibody (MOG Ab) associated demyelination represents a subgroup of autoimmune demyelination that is separate from multiple sclerosis and aquaporin 4 IgG-positive NMO, and can have a relapsing course. Unlike NMO and MS, there is a paucity of literature on immunopathology and CSF cytokine/chemokines in MOG Ab associated demyelination. Aim To study the differences in immunopathogenesis based on cytokine/chemokine profile in MOG Ab-positive (POS) and -negative (NEG) groups. Methods We measured 34 cytokines/chemokines using multiplex immunoassay in CSF collected from paediatric patients with serum MOG Ab POS [acute disseminated encephalomyelitis (ADEM = 8), transverse myelitis (TM = 2) n = 10] and serum MOG Ab NEG (ADEM = 5, TM = 4, n = 9) demyelination. We generated normative data using CSF from 20 non-inflammatory neurological controls. Results The CSF cytokine and chemokine levels were higher in both MOG Ab POS and MOG Ab NEG demyelination groups compared to controls. The CSF in MOG Ab POS patients showed predominant elevation of B cell related cytokines/chemokines (CXCL13, APRIL, BAFF and CCL19) as well as some of Th17 related cytokines (IL-6 AND G-CSF) compared to MOG Ab NEG group (all p<0.01). In addition, patients with elevated CSF MOG antibodies had higher CSF CXCL13, CXCL12, CCL19, IL-17A and G-CSF than patients without CSF MOG antibodies. Conclusion Our findings suggest that MOG Ab POS patients have a more pronounced CNS inflammatory response with elevation of predominant humoral associated cytokines/chemokines, as well as some Th 17 and neutrophil related cytokines/chemokines suggesting a differential inflammatory pathogenesis associated with MOG antibody seropositivity. This cytokine/chemokine profiling provides new insight into disease pathogenesis, and improves our ability to monitor inflammation and response to treatment. In addition, some of these molecules may represent potential immunomodulatory targets

  7. B Cell, Th17, and Neutrophil Related Cerebrospinal Fluid Cytokine/Chemokines Are Elevated in MOG Antibody Associated Demyelination.

    Directory of Open Access Journals (Sweden)

    Kavitha Kothur

    Full Text Available Myelin oligodendrocyte glycoprotein antibody (MOG Ab associated demyelination represents a subgroup of autoimmune demyelination that is separate from multiple sclerosis and aquaporin 4 IgG-positive NMO, and can have a relapsing course. Unlike NMO and MS, there is a paucity of literature on immunopathology and CSF cytokine/chemokines in MOG Ab associated demyelination.To study the differences in immunopathogenesis based on cytokine/chemokine profile in MOG Ab-positive (POS and -negative (NEG groups.We measured 34 cytokines/chemokines using multiplex immunoassay in CSF collected from paediatric patients with serum MOG Ab POS [acute disseminated encephalomyelitis (ADEM = 8, transverse myelitis (TM = 2 n = 10] and serum MOG Ab NEG (ADEM = 5, TM = 4, n = 9 demyelination. We generated normative data using CSF from 20 non-inflammatory neurological controls.The CSF cytokine and chemokine levels were higher in both MOG Ab POS and MOG Ab NEG demyelination groups compared to controls. The CSF in MOG Ab POS patients showed predominant elevation of B cell related cytokines/chemokines (CXCL13, APRIL, BAFF and CCL19 as well as some of Th17 related cytokines (IL-6 AND G-CSF compared to MOG Ab NEG group (all p<0.01. In addition, patients with elevated CSF MOG antibodies had higher CSF CXCL13, CXCL12, CCL19, IL-17A and G-CSF than patients without CSF MOG antibodies.Our findings suggest that MOG Ab POS patients have a more pronounced CNS inflammatory response with elevation of predominant humoral associated cytokines/chemokines, as well as some Th 17 and neutrophil related cytokines/chemokines suggesting a differential inflammatory pathogenesis associated with MOG antibody seropositivity. This cytokine/chemokine profiling provides new insight into disease pathogenesis, and improves our ability to monitor inflammation and response to treatment. In addition, some of these molecules may represent potential immunomodulatory targets.

  8. Toward antibody-directed "abzyme" prodrug therapy, ADAPT: carbamate prodrug activation by a catalytic antibody and its in vitro application to human tumor cell killing.

    OpenAIRE

    Wentworth, P; Datta, A.; Blakey, D; Boyle, T; Partridge, L. J.; Blackburn, G M

    1996-01-01

    Antibody-directed enzyme prodrug therapy, ADEPT, is a recent approach to targeted cancer chemotherapy intended to diminish the nonspecific toxicity associated with many commonly used chemotherapeutic agents. Most ADEPT systems incorporate a bacterial enzyme, and thus their potential is reduced because of the immunogenicity of that component of the conjugate. This limitation can be circumvented by the use of a catalytic antibody, which can be "humanized," in place of the bacterial enzyme catal...

  9. Evaluation of an in vitro method for the measurement of specific IgE antibody responses: the rat basophilic leukemia (RBL) cell assay

    International Nuclear Information System (INIS)

    The evaluation of allergenic potential is a key parameter in the safety assessment of novel proteins, including those expressed in genetically modified crops and foodstuffs. The majority of allergic reactions to food proteins are immediate type hypersensitivity reactions in which the principal biological effector is IgE antibody; the accurate measurement of specific IgE antibody is therefore a critical factor in experimental systems designed to characterize protein allergenic potential. Due to the presence of much higher concentrations of other immunoglobulin isotypes, the assessment of specific serum IgE antibody poses substantial technical challenges. We have examined the utility of the rat basophilic leukemia (RBL) cell line for the measurement of murine IgE responses. RBL cells were sensitized with mouse monoclonal anti-dinitrophenyl (DNP) IgE antibody and challenged with DNP-albumin conjugates with various hapten substitution ratios (SR). Polyclonal anti-OVA IgE antisera were also assessed for activity in the RBL assay. Results were compared with titers measured in homologous passive cutaneous anaphylaxis (PCA) assay. Marked degranulation of RBL cells was induced by conjugates with SRs of between 16 and 32, whereas conjugates with lower SRs (of 10 or 3) failed to elicit significant serotonin release. All conjugates were able to induce mast cell degranulation in vivo in a PCA assay. Anti-OVA antisera with PCA titers of 1/32 to 1/64 failed to stimulate RBL cell degranulation, whereas high titer antibody (1/2048 to 1/4096 by PCA) induced a positive RBL cell response. Successful stimulation of RBL cell degranulation requires not only appropriate epitope densities but also high affinity antibody. These data indicate that this assay is inappropriate for the routine analysis of specific polyclonal IgE antibody responses such as those that are induced by exposure to complex protein allergens

  10. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

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

  11. Anti-HMGB1 Neutralizing Antibody Ameliorates Neutrophilic Airway Inflammation by Suppressing Dendritic Cell-Mediated Th17 Polarization

    Directory of Open Access Journals (Sweden)

    Fang Zhang

    2014-01-01

    Full Text Available We demonstrate that high mobility group box 1 protein (HMGB1 directs Th17 skewing by regulating dendritic cell (DC function. First, our in vitro studies reveal that recombinant HMGB1 (rHMGB1 activates myeloid DCs to produce IL-23 in vitro, and rHMGB1-activated DCs prime naïve lymphocytes to produce the Th17 cytokine IL-17A. Second, we demonstrate that anti-HMGB1 neutralizing antibody attenuates HMGB1 expression, neutrophilic inflammation, airway hyperresponsiveness, and Th17-related cytokine secretion in vivo by using a murine model of neutrophilic asthma induced by ovalbumin (OVA plus lipopolysaccharide (LPS. Furthermore, anti-HMGB1 neutralizing antibody decreases the number of Th17 cells in lung cells and suppresses the production of IL-23 by lung CD11C+ APCs. Finally, we show that intranasal adoptive transfer of rHMGB1-activated DCs was sufficient to restore lung neutrophilic inflammation and the Th17 response in a DC-driven model of asthma, whereas the transfer of rHMGB1 plus anti-HMGB1-treated mDCs significantly reduced these inflammation phenotypes. These data suggest, for the first time, that HMGB1 drives the DC-polarized Th17-type response in allergic lung inflammation and that blocking HMGB1 may benefit the attenuation of neutrophilic airway inflammation in asthma.

  12. FcγRIIB on liver sinusoidal endothelial cells is essential for antibody-induced GPVI ectodomain shedding in mice.

    Science.gov (United States)

    Stegner, David; Popp, Michael; Lorenz, Viola; Wax, Jacqueline K; Gessner, J Engelbert; Nieswandt, Bernhard

    2016-08-11

    The activating platelet collagen receptor glycoprotein VI (GPVI) is a promising antithrombotic target because of its central role in arterial thrombosis and its minor relevance for normal hemostasis. The receptor can be specifically targeted by antibodies and irreversibly downregulated in circulating platelets in vivo, resulting in long-term antithrombotic protection in mice. This GPVI immunodepletion predominantly occurs through ectodomain shedding, which is accompanied by a transient drop in peripheral platelet counts. Mechanistic studies on this targeted GPVI loss have been hampered because it cannot be reproduced in isolated platelets in vitro. Here we show that both the transient thrombocytopenia and GPVI ectodomain shedding depend on the Fc portion of the anti-GPVI antibody and its interaction with the inhibitory Fcγ receptor (FcγR)IIB. In wild-type, but not Fcgr2b(-/-) mice, anti-GPVI-opsonized platelets became transiently trapped in the liver followed by the appearance of the soluble GPVI ectodomain in the plasma. Depletion of Kupffer cells neither affected anti-GPVI-induced platelet accumulation nor GPVI shedding, demonstrating that the other major FcγRIIB-expressing cell type, liver sinusoidal endothelial cells, is required for both processes to occur. These results reveal a novel and unexpected function of hepatic FcγRIIB in the targeted downregulation of GPVI in vivo. PMID:27297794

  13. The phosphoproteome of human Jurkat T cell clones upon costimulation with anti-CD3/anti-CD28 antibodies.

    Science.gov (United States)

    Nguyen, Tien Dung; Carrascal, Montserrat; Vidal-Cortes, Oriol; Gallardo, Oscar; Casas, Vanessa; Gay, Marina; Phan, Van Chi; Abian, Joaquin

    2016-01-10

    Phosphorylation is a reversible post-translational modification, playing a vital role in protein function. In T cells, protein phosphorylation is the key mechanism regulating T cell receptor-driven signaling pathways. In order to gain insights into the phosphoproteome evolution of T cell activation, we performed a large-scale quantitative phosphoproteomics study of Jurkat E6.1 (wild type) and Jurkat gamma1 (Phospholipase gamma1 null) cell clones upon costimulation with anti-CD3 and anti-CD28 antibodies at times ranging from 15min to as long as 120min. In total, we identified 5585 phosphopeptides belonging to 2008 phosphoproteins from both cell clones. We detected 130 and 114 novel phosphopeptides in Jurkat E6.1 and Jurkat gamma1 clones, respectively. A significantly lower number of proteins containing regulated phosphorylation sites were identified in Jurkat gamma1 in comparison to Jurkat E6.1, reflecting the vital role of Phospholipase gamma1 in T cell signaling. Several new phosphorylation sites from lymphocyte-specific protein tyrosine kinase (Lck) were identified. Of these, serine-121 showed significant changes in JE6.1 while only small changes in the Jgamma1 clone. Our data may contribute to the current human T cell phosphoproteome and provide a better understanding on T cell receptor signaling. Data are available via ProteomeXchange with identifier PXD002871. PMID:26546556

  14. Characterization of a novel single-chain bispecific antibody for retargeting of T cells to tumor cells via the TCR co-receptor CD8.

    Directory of Open Access Journals (Sweden)

    Irene Michalk

    Full Text Available There is currently growing interest in retargeting of effector T cells to tumor cells via bispecific antibodies (bsAbs. Usually, bsAbs are directed on the one hand to the CD3 complex of T cells and on the other hand to a molecule expressed on the surface of the target cell. A bsAb-mediated cross-linkage via CD3 leads to an activation of CD8+ T cells and consequently to killing of the target cells. In parallel, CD4+ T cells including TH1, TH2, TH17 cells and even regulatory T cells (Tregs will be activated as well. Cytokines produced by CD4+ T cells can contribute to severe side effects e. g. life-threatening cytokine storms and, thinking of the immunosupressive function of Tregs, can even be counterproductive. Therefore, we asked whether or not it is feasible to limit retargeting to CD8+ T cells e. g. via targeting of the co-receptor CD8 instead of CD3. In order to test for proof of concept, a novel bsAb with specificity for CD8 and a tumor-associated surface antigen was constructed. Interestingly, we found that pre-activated (but not freshly isolated CD8+ T cells can be retargeted via CD8-engaging bsAbs leading to an efficient lysis of target cells.

  15. Differential regulation of interleukin 4 and interleukin 5 gene expression: a comparison of T-cell gene induction by anti-CD3 antibody or by exogenous lymphokines.

    OpenAIRE

    Bohjanen, P R; Okajima, M; Hodes, R J

    1990-01-01

    Murine T helper type 2 clones were stimulated with immobilized anti-CD3 antibody or with recombinant lymphokines to compare the expression of T-cell activation genes induced by these stimuli. Immobilized anti-CD3 antibody, recombinant interleukin 2 (IL-2), and recombinant interleukin 4 (IL-4) all induced proliferation of the T helper type 2 clones 10-5-17 and D10. Proliferation of these clones induced by anti-CD3 antibody was completely inhibited by cyclosporine A, whereas cyclosporine A had ...

  16. The strength of the antibody response to the nematode Ascaris lumbricoides inversely correlates with levels of B-Cell Activating Factor (BAFF)

    OpenAIRE

    Bornacelly, Adriana; Mercado, Dilia; Acevedo, Nathalie; Caraballo, Luis

    2014-01-01

    Background B-Cell Activating Factor (BAFF) is a cytokine regulating antibody production. Polymorphisms in the gene encoding BAFF were associated with the antibody response to Ascaris but not to mite allergens. In the present study we evaluated the relationship between BAFF and specific antibodies against Ascaris and mites in 448 controls and 448 asthmatics. Soluble BAFF was measured by ELISA and BAFF mRNA by qPCR. Surface expression of BAFF and its receptor (BAFF-R) was analyzed by flow cytom...

  17. A New Triglycyl Peptide Linker for Antibody-Drug Conjugates (ADCs) with Improved Targeted Killing of Cancer Cells.

    Science.gov (United States)

    Singh, Rajeeva; Setiady, Yulius Y; Ponte, Jose; Kovtun, Yelena V; Lai, Katharine C; Hong, E Erica; Fishkin, Nathan; Dong, Ling; Jones, Gregory E; Coccia, Jennifer A; Lanieri, Leanne; Veale, Karen; Costoplus, Juliet A; Skaletskaya, Anna; Gabriel, Rabih; Salomon, Paulin; Wu, Rui; Qiu, Qifeng; Erickson, Hans K; Lambert, John M; Chari, Ravi V J; Widdison, Wayne C

    2016-06-01

    A triglycyl peptide linker (CX) was designed for use in antibody -: drug conjugates (ADC), aiming to provide efficient release and lysosomal efflux of cytotoxic catabolites within targeted cancer cells. ADCs comprising anti-epithelial cell adhesion molecule (anti-EpCAM) and anti-EGFR antibodies with maytansinoid payloads were prepared using CX or a noncleavable SMCC linker (CX and SMCC ADCs). The in vitro cytotoxic activities of CX and SMCC ADCs were similar for several cancer cell lines; however, the CX ADC was more active (5-100-fold lower IC50) than the SMCC ADC in other cell lines, including a multidrug-resistant line. Both CX and SMCC ADCs showed comparable MTDs and pharmacokinetics in CD-1 mice. In Calu-3 tumor xenografts, antitumor efficacy was observed with the anti-EpCAM CX ADC at a 5-fold lower dose than the corresponding SMCC ADC in vivo Similarly, the anti-EGFR CX ADC showed improved antitumor activity over the respective SMCC conjugate in HSC-2 and H1975 tumor models; however, both exhibited similar activity against FaDu xenografts. Mechanistically, in contrast with the charged lysine-linked catabolite of SMCC ADC, a significant fraction of the carboxylic acid catabolite of CX ADC could be uncharged in the acidic lysosomes, and thus diffuse out readily into the cytosol. Upon release from tumor cells, CX catabolites are charged at extracellular pH and do not penetrate and kill neighboring cells, similar to the SMCC catabolite. Overall, these data suggest that CX represents a promising linker option for the development of ADCs with improved therapeutic properties. Mol Cancer Ther; 15(6); 1311-20. ©2016 AACR. PMID:27197308

  18. A Rapid Method to Characterize Mouse IgG Antibodies and Isolate Native Antigen Binding IgG B Cell Hybridomas.

    Directory of Open Access Journals (Sweden)

    Haolin Liu

    Full Text Available B cell hybridomas are an important source of monoclonal antibodies. In this paper, we developed a high-throughput method to characterize mouse IgG antibodies using surface plasmon resonance technology. This assay rapidly determines their sub-isotypes, whether they bind native antigen and their approximate affinities for the antigen using only 50 μl of hybridoma cell culture supernatant. Moreover, we found that mouse hybridomas secreting IgG antibodies also have membrane form IgG expression without Igα. Based on this surface IgG, we used flow cytometry to isolate rare γ2a isotype switched variants from a γ2b antibody secreting hybridoma cell line. Also, we used fluorescent antigen to single cell sort antigen binding hybridoma cells from bulk mixture of fused hybridoma cells instead of the traditional multi-microwell plate screening and limiting dilution sub-cloning thus saving time and labor. The IgG monoclonal antibodies specific for the native antigen identified with these methods are suitable for in vivo therapeutic uses, but also for sandwich ELISA assays, histology, flow cytometry, immune precipitation and x-ray crystallography.

  19. Experimental and in silico modelling analyses of the gene expression pathway for recombinant antibody and by-product production in NS0 cell lines.

    Directory of Open Access Journals (Sweden)

    Emma J Mead

    Full Text Available Monoclonal antibodies are commercially important, high value biotherapeutic drugs used in the treatment of a variety of diseases. These complex molecules consist of two heavy chain and two light chain polypeptides covalently linked by disulphide bonds. They are usually expressed as recombinant proteins from cultured mammalian cells, which are capable of correctly modifying, folding and assembling the polypeptide chains into the native quaternary structure. Such recombinant cell lines often vary in the amounts of product produced and in the heterogeneity of the secreted products. The biological mechanisms of this variation are not fully defined. Here we have utilised experimental and modelling strategies to characterise and define the biology underpinning product heterogeneity in cell lines exhibiting varying antibody expression levels, and then experimentally validated these models. In undertaking these studies we applied and validated biochemical (rate-constant based and engineering (nonlinear models of antibody expression to experimental data from four NS0 cell lines with different IgG4 secretion rates. The models predict that export of the full antibody and its fragments are intrinsically linked, and cannot therefore be manipulated individually at the level of the secretory machinery. Instead, the models highlight strategies for the manipulation at the precursor species level to increase recombinant protein yields in both high and low producing cell lines. The models also highlight cell line specific limitations in the antibody expression pathway.

  20. Experimental and in silico modelling analyses of the gene expression pathway for recombinant antibody and by-product production in NS0 cell lines.

    Science.gov (United States)

    Mead, Emma J; Chiverton, Lesley M; Spurgeon, Sarah K; Martin, Elaine B; Montague, Gary A; Smales, C Mark; von der Haar, Tobias

    2012-01-01

    Monoclonal antibodies are commercially important, high value biotherapeutic drugs used in the treatment of a variety of diseases. These complex molecules consist of two heavy chain and two light chain polypeptides covalently linked by disulphide bonds. They are usually expressed as recombinant proteins from cultured mammalian cells, which are capable of correctly modifying, folding and assembling the polypeptide chains into the native quaternary structure. Such recombinant cell lines often vary in the amounts of product produced and in the heterogeneity of the secreted products. The biological mechanisms of this variation are not fully defined. Here we have utilised experimental and modelling strategies to characterise and define the biology underpinning product heterogeneity in cell lines exhibiting varying antibody expression levels, and then experimentally validated these models. In undertaking these studies we applied and validated biochemical (rate-constant based) and engineering (nonlinear) models of antibody expression to experimental data from four NS0 cell lines with different IgG4 secretion rates. The models predict that export of the full antibody and its fragments are intrinsically linked, and cannot therefore be manipulated individually at the level of the secretory machinery. Instead, the models highlight strategies for the manipulation at the precursor species level to increase recombinant protein yields in both high and low producing cell lines. The models also highlight cell line specific limitations in the antibody expression pathway. PMID:23071804

  1. Demonstration of dnp groups on the draining lymph node cells of guinea pigs following skin painting with DNCB by peroxidase labelled antibody method.

    Directory of Open Access Journals (Sweden)

    Tada,Hiroshi

    1981-06-01

    Full Text Available The distribution of 2,4-dinitrophenyl (DNP groups in the draining lymph nodes of guinea pigs 12 h after painting the skin with 2,4-dinitrochlorobenzene (DNCB was examined by a peroxidase labelled antibody method using antibody against DNP groups. DNP groups were detected on cells that were found mainly in the subcapsular sinus of the lymph nodes. Electron microscopic examination showed DNP groups distributed on the surface of lymphocytes. The significance of these findings is discussed.

  2. Interplay of foot-and-mouth disease virus, antibodies and plasmacytoid dendritic cells: virus opsonization under non-neutralizing conditions results in enhanced interferon-alpha responses

    OpenAIRE

    Lannes Nils; Python Sylvie; Summerfield Artur

    2012-01-01

    Abstract Foot-and-mouth disease virus (FMDV) is a highly infectious member of the Picornaviridae inducing an acute disease of cloven-hoofed species. Vaccine-induced immune protection correlates with the presence of high levels of neutralizing antibodies but also opsonising antibodies have been proposed as an important mechanism of the immune response contributing to virus clearance by macrophages and leading to the production of type-I interferon (IFN) by plasmacytoid dendritic cells (pDC). T...

  3. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity.

    Directory of Open Access Journals (Sweden)

    Martin Kreutz

    Full Text Available Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA and CpG oligodeoxynucleotides (ODN. We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses.

  4. Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mu [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Ruan Yuxia [Department of Ophthalmology, The First Affiliated Hospital, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Xing Xiaobo; Chen Qian; Peng, Yuan [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Cai Jiye, E-mail: tjycai@jnu.edu.cn [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China)

    2011-07-04

    Graphical abstract: Highlights: > In this study, we investigate the changes of CD44 expression and distribution on HepG2 cells after curcumin treatment. > We find curcumin is able to change the morphology and ultrastructure of HepG2 cells. > Curcumin can reduce the expression of CD44 molecules and induce the nanoscale molecular redistribution on cell surface. > The binding force between CD44-modified AFM tip and the HepG2 cell surface decreases after curcumin-treatment. - Abstract: The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 {+-} 4.62 nm to 129.70 {+-} 43.72 nm) and the expression of CD44 decreased (99.79 {+-} 0.16% to 75.14 {+-} 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 {mu}M curcumin-treated) and 50-120 pN (20 {mu}M curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

  5. T-cell ligands modulate the cytolytic activity of the CD33/CD3 BiTE antibody construct, AMG 330

    International Nuclear Information System (INIS)

    Preclinical and emerging clinical studies demonstrate that bispecific T-cell engaging (BiTE) antibody constructs can potently lyse targeted tumor cells, but the determinants for their activity remain incompletely understood. Using human acute myeloid leukemia (AML) cell lines engineered to overexpress individual T-cell ligands, we found that expression of the inhibitory ligands, PD-L1 and PD-L2, reduced the cytolytic activity of the BiTE antibody construct targeting CD33, AMG 330; conversely, expression of the activating ligands, CD80 and CD86, augmented the cytotoxic activity of AMG 330. Consistent with these findings, treatment with an activating antibody directed at the co-stimulatory T-cell receptor, CD28, significantly increased AMG 330-induced cytotoxicity in human AML cell lines. Using specimens from 12 patients with newly diagnosed or relapsed/refractory AML, we found that activation of CD28 also increased the activity of AMG 330 in primary human AML cells (P=0.023). Together, our findings indicate that T-cell ligands and co-receptors modulate the anti-tumor activity of the CD33/CD3 BiTE antibody construct, AMG 330. These findings suggest that such ligands/co-receptors could serve as biomarkers of response and that co-treatment strategies with pharmacological modulators of T-cell receptor signaling could be utilized to further enhance the activity of this targeted therapeutic

  6. Effects of antibodies induced by a conjugate vaccine on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone absorptive transport, metabolism, and proliferation of human lung cells.

    Science.gov (United States)

    De Buck, Stefan S; Schellenberger, Mario T; Ensch, Corinne; Muller, Claude P

    2010-08-01

    One of the most abundant and potent lung carcinogen is the nicotine-derived tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The monoclonal antibody P9D5 induced with a NNK-conjugate vaccine was used to investigate the ability of NNK-specific antibodies to modulate NNK-induced adverse effects as well as its absorptive transport and metabolism in two lung cancer cell lines (Calu-3 and NCI-H82). Transport experiments in Calu-3 cells with a 50-fold molar excess of apical P9D5 increased the recovery of coadministered apical NNK, with a concomitant decrease in NNK transepithelial transport of more than 50% compared to controls. In contrast, basolateral P9D5 did neither influence transepithelial transport of NNK nor its disappearance from the apical compartment. Calu-3 cells were also found to reduce NNK to NNAL and a 65-fold molar excess of NNK-specific antibody inhibited this metabolic conversion by 46 and 54% compared to irrelevant control antibody after 48 and 72 hr, respectively. The biological relevance of NNK redistribution by antibody was demonstrated by reversion of NNK-induced cell proliferation in NCI-H82 cells. Repartitioning of tobacco carcinogens by antibody may reduce their early effective peak concentrations in susceptible target organs and thus relieve overloaded local DNA repair mechanisms and diminish carcinogen-induced cell proliferation. These in vitro data therefore suggest that a prophylactic antibody response may be associated with a reduced risk of cancer. PMID:19960439

  7. The importance of cellular internalization of antibody-targeted carbon nanotubes in the photothermal ablation of breast cancer cells

    International Nuclear Information System (INIS)

    Single-walled carbon nanotubes (CNTs) convert absorbed near infrared (NIR) light into heat. The use of CNTs in the NIR-mediated photothermal ablation of tumor cells is attractive because the penetration of NIR light through normal tissues is optimal and the side effects are minimal. Targeted thermal ablation with minimal collateral damage can be achieved by using CNTs attached to tumor-specific monoclonal antibodies (MAbs). However, the role that the cellular internalization of CNTs plays in the subsequent sensitivity of the target cells to NIR-mediated photothermal ablation remains undefined. To address this issue, we used CNTs covalently coupled to an anti-Her2 or a control MAb and tested their ability to bind, internalize, and photothermally ablate Her2+ but not Her2- breast cancer cell lines. Using flow cytometry, immunofluorescence, and confocal Raman microscopy, we observed the gradual time-dependent receptor-mediated endocytosis of anti-Her2-CNTs whereas a control MAb-CNT conjugate did not bind to the cells. Most importantly, the Her2+ cells that internalized the MAb-CNTs were more sensitive to NIR-mediated photothermal damage than cells that could bind to, but not internalize the MAb-CNTs. These results suggest that both the targeting and internalization of MAb-CNTs might result in the most effective thermal ablation of tumor cells following their exposure to NIR light.

  8. Mediation of cytotoxic functions by classes and subclasses of sheep antibody reactive with cell surface immunoglobulin idiotypic and constant region determinants

    International Nuclear Information System (INIS)

    Sheep antibodies, reactive with either the idiotypic or constant region antigenic determinants of the immunoglobulin light chain in guinea-pig L2C leukaemic cells, were separated into IgM and into the two subclasses of IgG, IgG1 and IgG2. Antibody of both IgG subclasses inhibited the migration of L2C cells along plastic surfaces; IgM was only weakly inhibitory. Antibody of class IgM and of subclass IgG1 mediated complement cytotoxicity against the L2C cells whereas only that of subclass IgG2 mediated K-cell cytotoxicity; the effector arms were rabbit complement and sheep peripheral leucocytes, respectively. (author)

  9. Retinoblastoma-independent antiproliferative activity of novel intracellular antibodies against the E7 oncoprotein in HPV 16-positive cells

    International Nuclear Information System (INIS)

    'High risk' Human Papillomavirus strains are the causative agents of the vast majority of carcinomas of the uterine cervix. In these tumors, the physical integration of the HPV genome is a frequent, though not invariable occurrence, but the constitutive expression of the E6 and E7 viral genes is always observed, suggesting key roles for the E6 and E7 oncoproteins in the process of malignant transformation. The 'intracellular antibody' technology using recombinant antibodies in single-chain format offers the possibility of targeting a protein in its intracellular environment even at the level of definite domains thus representing a valuable strategy to 'knock out' the function of specific proteins. In this study, we investigate the in vitro activity of two single-chain antibody fragments directed against the 'high-risk' HPV 16 E7 oncoprotein, scFv 43M2 and scFv 51. These scFvs were expressed by retroviral system in different cell compartments of the HPV16-positive SiHa cells, and cell proliferation was analyzed by Colony Formation Assay and EZ4U assay. The binding of these scFvs to E7, and their possible interference with the interaction between E7 and its main target, the tumor suppressor pRb protein, were then investigated by immunoassays, PepSet™technology and Surface Plasmon Resonance. The expression of the two scFvs in the nucleus and the endoplasmic reticulum of SiHa cells resulted in the selective growth inhibition of these cells. Analysis of binding showed that both scFvs bind E7 via distinct but overlapping epitopes not corresponding to the pRb binding site. Nevertheless, the binding of scFv 43M2 to E7 was inhibited by pRb in a non-competitive manner. Based on the overall results, the observed inhibition of HPV-positive SiHa cells proliferation could be ascribed to an interaction between scFv and E7, involving non-pRb targets. The study paves the way for the employment of specific scFvs in immunotherapeutic

  10. Virus-specific antibodies allow viral replication in the marginal zone, thereby promoting CD8+ T-cell priming and viral control

    Science.gov (United States)

    Duhan, Vikas; Khairnar, Vishal; Friedrich, Sarah-Kim; Zhou, Fan; Gassa, Asmae; Honke, Nadine; Shaabani, Namir; Gailus, Nicole; Botezatu, Lacramioara; Khandanpour, Cyrus; Dittmer, Ulf; Häussinger, Dieter; Recher, Mike; Hardt, Cornelia; Lang, Philipp A.; Lang, Karl S.

    2016-01-01

    Clinically used human vaccination aims to induce specific antibodies that can guarantee long-term protection against a pathogen. The reasons that other immune components often fail to induce protective immunity are still debated. Recently we found that enforced viral replication in secondary lymphoid organs is essential for immune activation. In this study we used the lymphocytic choriomeningitis virus (LCMV) to determine whether enforced virus replication occurs in the presence of virus-specific antibodies or virus-specific CD8+ T cells. We found that after systemic recall infection with LCMV-WE the presence of virus-specific antibodies allowed intracellular replication of virus in the marginal zone of spleen. In contrast, specific antibodies limited viral replication in liver, lung, and kidney. Upon recall infection with the persistent virus strain LCMV-Docile, viral replication in spleen was essential for the priming of CD8+ T cells and for viral control. In contrast to specific antibodies, memory CD8+ T cells inhibited viral replication in marginal zone but failed to protect mice from persistent viral infection. We conclude that virus-specific antibodies limit viral infection in peripheral organs but still allow replication of LCMV in the marginal zone, a mechanism that allows immune boosting during recall infection and thereby guarantees control of persistent virus. PMID:26805453

  11. Virus-specific antibodies allow viral replication in the marginal zone, thereby promoting CD8(+) T-cell priming and viral control.

    Science.gov (United States)

    Duhan, Vikas; Khairnar, Vishal; Friedrich, Sarah-Kim; Zhou, Fan; Gassa, Asmae; Honke, Nadine; Shaabani, Namir; Gailus, Nicole; Botezatu, Lacramioara; Khandanpour, Cyrus; Dittmer, Ulf; Häussinger, Dieter; Recher, Mike; Hardt, Cornelia; Lang, Philipp A; Lang, Karl S

    2016-01-01

    Clinically used human vaccination aims to induce specific antibodies that can guarantee long-term protection against a pathogen. The reasons that other immune components often fail to induce protective immunity are still debated. Recently we found that enforced viral replication in secondary lymphoid organs is essential for immune activation. In this study we used the lymphocytic choriomeningitis virus (LCMV) to determine whether enforced virus replication occurs in the presence of virus-specific antibodies or virus-specific CD8(+) T cells. We found that after systemic recall infection with LCMV-WE the presence of virus-specific antibodies allowed intracellular replication of virus in the marginal zone of spleen. In contrast, specific antibodies limited viral replication in liver, lung, and kidney. Upon recall infection with the persistent virus strain LCMV-Docile, viral replication in spleen was essential for the priming of CD8(+) T cells and for viral control. In contrast to specific antibodies, memory CD8(+) T cells inhibited viral replication in marginal zone but failed to protect mice from persistent viral infection. We conclude that virus-specific antibodies limit viral infection in peripheral organs but still allow replication of LCMV in the marginal zone, a mechanism that allows immune boosting during recall infection and thereby guarantees control of persistent virus. PMID:26805453

  12. De novo identification of VRC01 class HIV-1–neutralizing antibodies by next-generation sequencing of B-cell transcripts

    Science.gov (United States)

    Zhu, Jiang; Wu, Xueling; Zhang, Baoshan; McKee, Krisha; O’Dell, Sijy; Soto, Cinque; Zhou, Tongqing; Casazza, Joseph P.; Mullikin, James C.; Kwong, Peter D.; Mascola, John R.; Shapiro, Lawrence

    2013-01-01

    Next-generation sequencing of antibody transcripts provides a wealth of data, but the ability to identify function-specific antibodies solely on the basis of sequence has remained elusive. We previously characterized the VRC01 class of antibodies, which target the CD4-binding site on gp120, appear in multiple donors, and broadly neutralize HIV-1. Antibodies of this class have developmental commonalities, but typically share only ∼50% amino acid sequence identity among different donors. Here we apply next-generation sequencing to identify VRC01 class antibodies in a new donor, C38, directly from B cell transcript sequences. We first tested a lineage rank approach, but this was unsuccessful, likely because VRC01 class antibody sequences were not highly prevalent in this donor. We next identified VRC01 class heavy chains through a phylogenetic analysis that included thousands of sequences from C38 and a few known VRC01 class sequences from other donors. This “cross-donor analysis” yielded heavy chains with little sequence homology to previously identified VRC01 class heavy chains. Nonetheless, when reconstituted with the light chain from VRC01, half of the heavy chain chimeric antibodies showed substantial neutralization potency and breadth. We then identified VRC01 class light chains through a five-amino-acid sequence motif necessary for VRC01 light chain recognition. From over a million light chain sequences, we identified 13 candidate VRC01 class members. Pairing of these light chains with the phylogenetically identified C38 heavy chains yielded functional antibodies that effectively neutralized HIV-1. Bioinformatics analysis can thus directly identify functional HIV-1–neutralizing antibodies of the VRC01 class from a sequenced antibody repertoire. PMID:24106303

  13. Detection of antibodies to bacterial cell wall peptidoglycan in human sera. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Heymer, B.; Schleifer, K.H.; Read, S.; Zabriskie, J.B.; Krause, R.M.

    1976-07-01

    A radioimmunoassay has been developed for the measurement of antibodies to peptidoglycan in human sera including patients with rheumatic feaver and juvenile rheumatoid arthritis. The assay is based on the percentage of binding of the hapten /sup 125/I-L-Ala-..gamma..-D-Glu-L-Lys-D-Ala-D-Ala, the major peptide determinant of peptidoglycan. Because of differences in the avidity of the antibodies in different sera, the amount of antibody was expressed as pentapeptide hapten-binding capacity (pentapeptide-HBC in ng/ml of serum). Fourteen out of 105 normal blood donors had a pentapeptide-HBC value greater than or equal to 75 ng/ml serum. Values in healthy children 5 to 18 years of age were less than or equal to 50 ng/ml. Sixty-eight percent of the individuals with rheumatic fever had values greater than or equal to 75 ng/ml, an indication that streptococcal infections can stimulate an immune response to peptidoglycan. Thirty-five percent of the patients with juvenile rheumatoid arthritis had values greater than or equal to 75 ng/ml. Such a finding points to a possible association between bacterial infections and juvenile rheumatoid arthritis.

  14. Detection of antibodies to bacterial cell wall peptidoglycan in human sera

    International Nuclear Information System (INIS)

    A radioimmunoassay has been developed for the measurement of antibodies to peptidoglycan in human sera including patients with rheumatic feaver and juvenile rheumatoid arthritis. The assay is based on the percentage of binding of the hapten 125I-L-Ala-γ-D-Glu-L-Lys-D-Ala-D-Ala, the major peptide determinant of peptidoglycan. Because of differences in the avidity of the antibodies in different sera, the amount of antibody was expressed as pentapeptide hapten-binding capacity (pentapeptide-HBC in ng/ml of serum). Fourteen out of 105 normal blood donors had a pentapeptide-HBC value greater than or equal to 75 ng/ml serum. Values in healthy children 5 to 18 years of age were less than or equal to 50 ng/ml. Sixty-eight percent of the individuals with rheumatic fever had values greater than or equal to 75 ng/ml, an indication that streptococcal infections can stimulate an immune response to peptidoglycan. Thirty-five percent of the patients with juvenile rheumatoid arthritis had values greater than or equal to 75 ng/ml. Such a finding points to a possible association between bacterial infections and juvenile rheumatoid arthritis

  15. Monoclonal antibodies recognizing epitopes of calretinins: dependence on Ca2+-binding status and differences in antigen accessibility in colon cancer cells.

    Science.gov (United States)

    Zimmermann, L; Schwaller, B

    2002-01-01

    Monoclonal antibodies are very helpful tools to investigate the localization and sometimes even the function of specific proteins in cells and tissues. By generating monoclonal antibodies against calretinin-22k (CR-22k), a C-terminally truncated isoform of calretinin (CR) as a result of alternative splicing of the CR mRNA, we envisaged that screening multiple monoclonal antibodies would allow the identification of CR-22k as well as CR. Both proteins share the first 178 amino acids, but have different C-termini. All three antibodies 10C10, 6B3 and 2H4 recognize recombinant CR-22k and the specificity to also recognize CR was demonstrated in brain extracts of different species and human tumour cells, which express CR. All monoclonal antibodies did not crossreact with the closely related protein calbindin D-28k. Antibody binding was depending on the Ca2+-binding status of both forms of calretinin. Generally, the Ca2+-bound form was better recognized than the Ca2+-free form. Carboxy- and amino-terminally truncated CR proteins were expressed in E. coli in order to characterize the epitopes recognized by the three antibodies. Additionally, tryptic and cyanogen bromide fragments were produced to further narrow down the sequences recognized by the three antibodies. 10C10 recognizes an epitope consisting of the linker region between EF-hand domains I and II and the N-terminal part of EF-hand II, while the others (6B3, 2H4) bind to a region including the linker between EF-hand domains III and IV. These antibodies are valuable tools to further investigate the distribution and eventually the specific function of these two proteins in the nervous tissue and under pathological conditions, e.g. in colon tumours and mesotheliomas. PMID:11990296

  16. Modeling the dynamics and migratory pathways of virus-specific antibody-secreting cell populations in primary influenza infection.

    Directory of Open Access Journals (Sweden)

    Hongyu Miao

    Full Text Available The B cell response to influenza infection of the respiratory tract contributes to viral clearance and establishes profound resistance to reinfection by related viruses. Numerous studies have measured virus-specific antibody-secreting cell (ASC frequencies in different anatomical compartments after influenza infection and provided a general picture of the kinetics of ASC formation and dispersion. However, the dynamics of ASC populations are difficult to determine experimentally and have received little attention. Here, we applied mathematical modeling to investigate the dynamics of ASC growth, death, and migration over the 2-week period following primary influenza infection in mice. Experimental data for model fitting came from high frequency measurements of virus-specific IgM, IgG, and IgA ASCs in the mediastinal lymph node (MLN, spleen, and lung. Model construction was based on a set of assumptions about ASC gain and loss from the sampled sites, and also on the directionality of ASC trafficking pathways. Most notably, modeling results suggest that differences in ASC fate and trafficking patterns reflect the site of formation and the expressed antibody class. Essentially all early IgA ASCs in the MLN migrated to spleen or lung, whereas cell death was likely the major reason for IgM and IgG ASC loss from the MLN. In contrast, the spleen contributed most of the IgM and IgG ASCs that migrated to the lung, but essentially none of the IgA ASCs. This finding points to a critical role for regional lymph nodes such as the MLN in the rapid generation of IgA ASCs that seed the lung. Results for the MLN also suggest that ASC death is a significant early feature of the B cell response. Overall, our analysis is consistent with accepted concepts in many regards, but it also indicates novel features of the B cell response to influenza that warrant further investigation.

  17. Natural killer T (NKT)–B-cell interactions promote prolonged antibody responses and long-term memory to pneumococcal capsular polysaccharides

    OpenAIRE

    Bai, Li; Deng, Shenglou; Reboulet, Rachel; Mathew, Rebecca; Teyton, Luc; Savage, Paul B.; Bendelac, Albert

    2013-01-01

    Antibodies directed against microbial polysaccharides are a critical component of protective immune responses and vaccines. We used nanoparticles coexpressing pneumococcal capsular polysaccharides and a cell wall lipid antigen analog to model NKT–B-cell interactions. Our study demonstrated CD1d-restricted cognate interactions, isotype switch, affinity maturation, and long-term memory, despite the apparent failure of NKT cells to differentiate into follicular helper cells. The findings demonst...

  18. A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

    DEFF Research Database (Denmark)

    Barington, T; Sparholt, S; Juul, L;

    1992-01-01

    A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...

  19. Induction of antigen-specific antibody response in human pheripheral blood lymphocytes in vitro by a dog kidney cell vaccine against rabies virus (DKCV).

    NARCIS (Netherlands)

    F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Ab); H.G. Loggen; R.H.J. Bakker (Roland); J.A.A.M. van Asten (Jack); J.G. Kreeftenberg; P. van der Marel; G. van Steenis (Bert)

    1983-01-01

    textabstractIn the present report an in vitro method for obtaining a secondary human antibody response to a dog kidney cell vaccine against rabies virus (DKCV) is described. Cultures of peripheral blood mononuclear cells from normal rabies-immune and nonimmune donors were stimulated in vitro by DKCV

  20. Improved Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) of Affinity Maturated and Fc-Engineered Antibodies Directed Against the AML Stem Cell Antigen CD96

    OpenAIRE

    Mohseni Nodehi, Sahar

    2011-01-01

    Regardless of progress in the therapy of AML, there is no long-term cure for about 70% of AML patients. Leukemic stem cells seem to be an important key for the perpetuation of AML.Most currently used chemotherapeutic agents are not able to eliminate AML-LSCs. The combination of conventional therapies with AML-LSCs-directed therapies may eventually lead to a cure for AML patients.Recently expression of CD96 was reported on AML-LSCs, while only very low expression levels were found on normal HS...