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Sample records for evading antibody avidity

  1. Avidity of anti-P aeruginosa antibodies during chronic infection in patients with cystic fibrosis

    DEFF Research Database (Denmark)

    Ciofu, O; Petersen, T D; Jensen, P

    1999-01-01

    BACKGROUND: In order to study the impact on the lung function of patients with cystic fibrosis of the avidity of antipseudomonal antibodies, the avidity of antibodies against the chromosomal beta-lactamase of Pseudomonas aeruginosa (a beta ab) and against the 60-65 kDa heat shock protein of P aer...

  2. AVIDITY EVALUATION OF LOCAL IgA ANTIBODIES IN PERSONS IMMUNIZED WITH LIVE INFLUENZA VACCINE

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    S. A. Donina

    2008-01-01

    Full Text Available Abstract. At present, immunogenicity evaluation of influenza vaccines is performed by quantitative assessment of increased serum antibodies. It was, however, shown that the degree of human defense against influenza is mostly related to their qualitative characteristics, i.e., avidity (functional activity. Leading role of local immunity is demonstrated in protection against influenza. Such immunity is mediated by IgA antibodies from mucosal airways. Meanwhile, the avidity issues for local antibodies still remain open.In present study, an attempt was undertaken to evaluate post-vaccination local immunological memory for influenza A virus, according to IgA antibodies from upper respiratory secretions. Two techniques were used to evaluate antibody avidity, that were previously applied for studying this phenomenon with serum imunoglobulins, i.e., a dynamic test (measurement of antigen-antibody reaction rates, and a test with urea, a chaotropic agent (avidity is determined as a strength of antigen-antibody complex. A total of 202 persons (18 to 20 years old were enrolled into the study.With both tests, a broad range of individual avidity values was observed for the antibodies. A significant cohort (up to 30 per cent of persons immunized with live influenza vaccine, showed sharply increased avidity of secretory IgA antibodies by both methods, along with accumulation of these immunoglobulins after vaccination. A reverse relationship is revealed between avidity levels of these antibodies before vaccination, and increase of this parameter post-immunization. The data present convincing arguments for specific renewal of local humoral immunological memory, as induced by live influenza vaccine. The study substantiates a necessity for application of the both tests in parallel, when determining avidity of secretory IgA antibodies. (Med. Immunol., vol. 10, N 4-5, pp 423-430.

  3. Avidity of Antibodies against HSV-2 and Risk to Neonatal Transmission among Mexican Pregnant Women

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    Antonia Herrera-Ortiz

    2013-01-01

    Full Text Available Objective. To determine HSV-2 seroprevalence, risk factors, and antibody avidity among a sample of Mexican pregnant women. Material and Methods. The avidity test was standardized with different urea concentrations and incubation times; the cut-off point was calculated to determine the low avidity (early infection. IgG antibodies against HSV-2 were detected from pregnant and postpartum women from Morelos, Mexico, and the avidity test was performed to positive samples. Multivariate regression logistic analysis was employed to evaluate demographic and sexual behavior characteristics associated with HSV-2 infection. Results. HSV-2 seroprevalence among Mexican women analyzed was 14.5% (333/2300, demographic factors (location of General Hospital, age, education level, and civil status, and risky sexual behaviors (STI self-report and number of sexual partners during last year were associated with HSV-2 infection. Seventeen women were detected with low avidity antibodies (early infection with a cut-off point of 66.1%. Conclusions. HSV-2 infection was common among this group of women from Mexico; the avidity test detected women with recent infections, and these women were more likely to transmit HSV-2 to their neonates. Neonatal herpes has no epidemiological surveillance, the disease could be overlooked, and so more studies are needed to estimate the magnitude of neonatal infection.

  4. Description of a novel multiplex avidity assay for evaluating HPV antibodies.

    Science.gov (United States)

    Brady, Allison M; Unger, Elizabeth R; Panicker, Gitika

    2017-08-01

    Limited data exists regarding antibody avidity for human papillomavirus (HPV). We describe development of a multiplex electrochemiluminescent avidity ELISA for four HPV types (HPV 6, 11, 16, 18) by adding a dissociating step to our established multiplex HPV VLP ELISA. Initial experiments exploring ammonium thiocyanate, sodium thiocyanate and guanidine hydrochloride (GuHCl) as dissociating agents identified GuHCl as most promising. Dissociation conditions with GuHCl were varied (concentration, incubation time, temperature) to select conditions with minimal impact on VLP integrity as measured with monoclonal antibodies to conformational epitopes. Avidity index (AI) was calculated based on a standard curve as ratio of bound IgG in GuHCl treated versus untreated sample. To evaluate our assay we determined AI in sera with known HPV titers. We selected 32 residual anonymized sera from individuals with a wide range of titers for HPV6, 11, 16, and 18. AIs were similar across multiple dilutions of serum within the assay's dynamic range and were reproducible with two plate lots. This assay will aid in understanding HPV antibody avidity and maturation in response to natural infection and varying vaccine schedules. This is the first report of a VLP-based multiplexed avidity ELISA that evaluates assay parameters for all nine HPV vaccine types. Copyright © 2017. Published by Elsevier B.V.

  5. Lack of Utility of Specific Immunoglobulin G Antibody Avidity for Serodiagnosis of Reactivated Toxoplasmosis in Immunocompromised Patients

    OpenAIRE

    Mechain, Bénédicte; Garin, Yves Jean-François; Robert-Gangneux, Florence; Dupouy-Camet, Jean; Derouin, Francis

    2000-01-01

    The avidities of Toxoplasma-specific immunoglobulin G serum antibodies were measured in immunocompromised patients presenting with cerebral or extracerebral toxoplasmosis and/or serological reactivation. Since avidity remained high and stable in 39 of 40 patients with toxoplasmosis and 27 of 28 patients with serological reactivation, we conclude that this test cannot help diagnose toxoplasmosis in these patients.

  6. Characterization of Tumor-Avid Antibody Fragments Genetically Engineered for Mono-Specific Radionuclide Chelation

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, T.P.

    2003-12-31

    The successful clinical application of targeted-radiopharmaceuticals depends on the development of molecules that optimize tumor specific radionuclide deposition and minimize non-specific organ irradiation. To this end, this proposal outlines a research effort to identify and evaluate novel antibodies and antibody fragments that bind breast tumors. The tumor-avid antibodies will be investigated for as imaging and therapeutic agents and to gain a better understanding of the pharmacokinetics and metabolism of radiolabeled tumor-avid antibody fragments through the use of site-specifically labeled molecules. Antibodies or antibody fragments, that bind breast carcinoma carbohydrate antigens, will be obtained from hybridoma or bacteriophage library screening. More specifically, antibody fragments that bind the carcinoma-associated Thomsen-Friedenreich (T) antigen will be radiolabeled with {sup 99m}Tc and {sup 188}Re at a natural amino acid chelation site and will be investigated in vivo for their abilities to target human breast tumors. In addition, site-specific radiolabeled antibody fragments will be biosynthesized using misacylated suppressor tRNAs. Homogeneously radiolabeled populations of antibody fragments will be used to investigate the effects of radionuclide location and chelation chemistries on their biodistribution and metabolism. It is hypothesized that site-specifically radiolabeled antibody fragments will possess enhanced tumor imaging and therapeutic properties due to optimal label location and conjugation chemistries. New insights into the factors that govern antibody metabolism in vivo are also expected from this work. Results from these studies should enhance our ability to design and synthesize radiolabeled antibody fragments that have improved pharmacokinetic properties. The studies in this proposal involve basic research into the development of antibody-based radiopharmaceuticals, with the ultimate goal of application in humans. This type of basic

  7. IgG avidity antibodies against Toxoplasma gondii in high risk females of reproductive age group in India.

    Science.gov (United States)

    Siddiqui, Naushaba; Shujatullah, Fatima; Khan, Haris M; Rabbani, Tamkin; Khan, Parvez A

    2014-10-01

    Toxoplasma gondii is an obligate intracellular protozoan that is distributed worldwide. Recently, several tests for avidity of Toxoplasma IgG antibodies have been introduced to help discriminate between recently acquired and distant infections. The study was conducted in Jawaharlal Nehru Medical College and Hospital, India from February 2011 to September 2012. Serum specimens were subjected to Toxoplasma IgM ELISA and IgG avidity ELISA test. Out of 48 patients with abortions, 17 (35.4%) were positive for IgM ELISA, and 8 (16.6%) had low IgG avidity antibodies. Out of 48 patients with other obstetric problems, 23 (47.9%) were positive for IgM ELISA, and 17 (35.4%) had low IgG avidity antibodies. Combining both groups on avidity test, only 25 of 40 (62.5%) IgM-positive women had low-avidity IgG antibodies suggesting a recent T. gondii infection in these women. More importantly, 15 (37.5%) of the IgM-positive women had high-avidity antibodies suggesting that the infection was acquired before gestation The relation of IgM seropositivity with the following risk factors was not found to be statistically significant; contact with cats (0.13), non-vegetarian food habits (0.05), and low socio-economic status (0.49). While, for IgG avidity ELISA, only contact with cats (0.01) was significantly associated with seropositivity. All other risk factors have P-values of >0.05 (not significant). IgG avidity test when used in combination with IgM test was a valuable assay for diagnosis of ongoing or recently acquired T. gondii infection in India.

  8. High avidity antibodies to full-length VAR2CSA correlate with absence of placental malaria.

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    Yeung Lo Tutterrow

    Full Text Available VAR2CSA mediates sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, increasing the risk of poor pregnancy outcomes. Naturally acquired antibodies (Ab to placental parasites at delivery have been associated with improved pregnancy outcomes, but Ab levels and how early in pregnancy Ab must be present in order to eliminate placental parasites before delivery remains unknown. Antibodies to individual Duffy-binding like domains of VAR2CSA have been studied, but the domains lack many of the conformational epitopes present in full-length VAR2CSA (FV2. Thus, the purpose of this study was to describe the acquisition of Ab to FV2 in women residing in high and low transmission areas and determine how Ab levels during pregnancy correlate with clearance of placental parasites. Plasma samples collected monthly throughout pregnancy from pregnant women living in high and low transmission areas in Cameroon were evaluated for Ab to FV2 and the proportion of high avidity Ab (i.e., Ab that remain bound in the presence of 3M NH(4SCN was assessed. Ab levels and proportion of high avidity Ab were compared between women with placental malaria (PM(+ and those without (PM(- at delivery. Results showed that PM(- women had significantly higher Ab levels (p = 0.0047 and proportion of high avidity Ab (p = 0.0009 than PM(+ women throughout pregnancy. Specifically, women with moderate to high Ab levels (>5,000 MFI and those with ≥ 35% high avidity Ab at 5-6 months were found to have 2.3 (95% CI, 1.0-4.9 and 7.6-fold (p = 0.0013, 95% CI: 1.2-50.0 reduced risk of placental malaria, respectively. These data show that high levels of Ab to FV2, particularly those with high avidity for FV2, produced by mid-pregnancy are important in clearing parasites from the placenta. Both high Ab levels and proportion of high avidity Ab to FV2 may serve as correlates of protection for assessing immunity against placental malaria.

  9. Kinetic and HPV infection effects on cross-type neutralizing antibody and avidity responses induced by Cervarix®

    Science.gov (United States)

    Kemp, Troy J.; Safaeian, Mahboobeh; Hildesheim, Allan; Pan, Yuanji; Penrose, Kerri J.; Porras, Carolina; Schiller, John T.; Lowy, Douglas R.; Herrero, Rolando; Pinto, Ligia A.

    2012-01-01

    Background We previously demonstrated that Cervarix® elicits antibody responses against vaccine-related types for which clinical efficacy was demonstrated (HPV-31 and -45). Here, we evaluated the kinetics of neutralization titers and avidity of Cervarix®-induced antibodies up to 36 months of follow-up in unexposed and HPV infected women. Methods A subset of women who participated in the Cost Rica HPV-16/18 Vaccine Trial had pre- and post-vaccination sera tested for antibody responses to HPV-16, -18, -31, -45, and -58 using a pseudovirion-based neutralization assay, and HPV-16 antibody avidity using an HPV-16 L1 VLP (virus-like particle)-based ELISA developed in our laboratory. Results In uninfected women, neutralizing antibody titers did not reach significance until after the 3rd dose for HPV-31 (month 12, p=0.009) and HPV-45 (month 12, p=0.003), but then persisted up to month 36 (HPV-31, p=0.01; HPV-45, p=0.002). Individuals infected with HPV-16 or HPV-31 at enrollment developed a significantly higher median antibody response to the corresponding HPV type after one dose, but there was not a difference between median titers after three doses compared to the HPV negative group. Median HPV-16 antibody avidity and titer increased over time up to month 12; however, the HPV-16 avidity did not correlate well with HPV-16 neutralizing antibody titers at each time point examined, except for month 6. The median avidity levels were higher in HPV-16 infected women at month 1 (p=0.04) and lower in HPV-16 infected women at month 12 (p=0.006) compared to the HPV negative women. Conclusions The persistence of cross-neutralization titers at month 36 suggests cross-reactive antibody responses are likely to persist long-term and are not influenced by infection status at enrollment. However, the weak correlation between avidity and neutralization titers emphasizes the need for examining avidity in efficacy studies to determine if high avidity antibodies play a critical role in

  10. Kinetic and HPV infection effects on cross-type neutralizing antibody and avidity responses induced by Cervarix(®).

    Science.gov (United States)

    Kemp, Troy J; Safaeian, Mahboobeh; Hildesheim, Allan; Pan, Yuanji; Penrose, Kerri J; Porras, Carolina; Schiller, John T; Lowy, Douglas R; Herrero, Rolando; Pinto, Ligia A

    2012-12-17

    We previously demonstrated that Cervarix(®) elicits antibody responses against vaccine-related types for which clinical efficacy was demonstrated (HPV-31 and -45). Here, we evaluated the kinetics of neutralization titers and avidity of Cervarix(®)-induced antibodies up to 36 months of follow-up in unexposed and HPV infected women. A subset of women who participated in the Cost Rica HPV-16/18 Vaccine Trial had pre- and post-vaccination sera tested for antibody responses to HPV-16, -18, -31, -45, and -58 using a pseudovirion-based neutralization assay, and HPV-16 antibody avidity using an HPV-16 L1 VLP (virus-like particle)-based ELISA developed in our laboratory. In uninfected women, neutralizing antibody titers did not reach significance until after the 3rd dose for HPV-31 (month 12, p=0.009) and HPV-45 (month 12, p=0.003), but then persisted up to month 36 (HPV-31, p=0.01; HPV-45, p=0.002). Individuals infected with HPV-16 or HPV-31 at enrollment developed a significantly higher median antibody response to the corresponding HPV type after one dose, but there was not a difference between median titers after three doses compared to the HPV negative group. Median HPV-16 antibody avidity and titer increased over time up to month 12; however, the HPV-16 avidity did not correlate well with HPV-16 neutralizing antibody titers at each time point examined, except for month 6. The median avidity levels were higher in HPV-16 infected women at month 1 (p=0.04) and lower in HPV-16 infected women at month 12 (p=0.006) compared to the HPV negative women. The persistence of cross-neutralization titers at month 36 suggests cross-reactive antibody responses are likely to persist long-term and are not influenced by infection status at enrollment. However, the weak correlation between avidity and neutralization titers emphasizes the need for examining avidity in efficacy studies to determine if high avidity antibodies play a critical role in protection against infection. Copyright

  11. Pregnancy does not affect HIV incidence test results obtained using the BED capture enzyme immunoassay or an antibody avidity assay

    National Research Council Canada - National Science Library

    Laeyendecker, Oliver; Church, Jessica D; Oliver, Amy E; Mwatha, Anthony; Owen, S Michele; Donnell, Deborah; Brookmeyer, Ron; Musoke, Philippa; Jackson, J Brooks; Guay, Laura; Nakabiito, Clemesia; Quinn, Thomas C; Eshleman, Susan H

    2010-01-01

    .... We used the BED capture immunoassay (BED) and an antibody avidity assay to test longitudinal samples from 51 HIV-infected Ugandan women infected with subtype A, C, D and intersubtype recombinant HIV who were enrolled in the HIVNET 012 trial...

  12. Interference of daratumumab with pretransfusion testing, mimicking a high-titer, low avidity like antibody

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    Mei-Hwa Lin

    2017-01-01

    Full Text Available Daratumumab is a monoclonal immunoglobulin against CD38 and has been approved for treating patients with refractory multiple myeloma. The presence of daratumumab in the sera can interfere with pretransfusion testing due to the weakly expression of CD38 on red cells. The reactivity could be mistaken as autoantibody (if autocontrol is positive or alloantibody (if autocontrol is negative. We present a case that demonstrates daratumumab could mimic a high titer low avidity (HTLA alloantibody. A 34-year-old male patient of refractory myeloma was recruited in phase three clinical trial involving daratumumab. Samples were sent to the blood bank for pretransfusion testing. Without knowledge of patient having used daratumumab, we mistook the reactivity in the patient's sera as an HTLA antibody due to the results of negative autocontrol and high titers of antibody activity. Antibody screen showed a panreactive pattern and the reactivity against screening cells was up to a titer of 1: 1240. The reactivity was weaker against cord cells than adult cells, became weaker against ZZAP-treated cells and became negative against DDT-treated cells. A discussion with attending physician finally revealed the reactivity was due to the interference caused by daratumumab. The case demonstrates good communication is essential in performing pretransfusion testing for patients receiving daratumumab and other new biological regimens that can interfere with compatibility test.

  13. Interference of daratumumab with pretransfusion testing, mimicking a high-titer, low avidity like antibody.

    Science.gov (United States)

    Lin, Mei-Hwa; Liu, Fei-Yun; Wang, Hsiu-Mien; Cho, Hsin-Ching; Lo, Shyh-Chyi

    2017-01-01

    Daratumumab is a monoclonal immunoglobulin against CD38 and has been approved for treating patients with refractory multiple myeloma. The presence of daratumumab in the sera can interfere with pretransfusion testing due to the weakly expression of CD38 on red cells. The reactivity could be mistaken as autoantibody (if autocontrol is positive) or alloantibody (if autocontrol is negative). We present a case that demonstrates daratumumab could mimic a high titer low avidity (HTLA) alloantibody. A 34-year-old male patient of refractory myeloma was recruited in phase three clinical trial involving daratumumab. Samples were sent to the blood bank for pretransfusion testing. Without knowledge of patient having used daratumumab, we mistook the reactivity in the patient's sera as an HTLA antibody due to the results of negative autocontrol and high titers of antibody activity. Antibody screen showed a panreactive pattern and the reactivity against screening cells was up to a titer of 1: 1240. The reactivity was weaker against cord cells than adult cells, became weaker against ZZAP-treated cells and became negative against DDT-treated cells. A discussion with attending physician finally revealed the reactivity was due to the interference caused by daratumumab. The case demonstrates good communication is essential in performing pretransfusion testing for patients receiving daratumumab and other new biological regimens that can interfere with compatibility test.

  14. Pregnancy does not affect HIV incidence test results obtained using the BED capture enzyme immunoassay or an antibody avidity assay.

    Directory of Open Access Journals (Sweden)

    Oliver Laeyendecker

    2010-10-01

    Full Text Available Accurate incidence estimates are needed for surveillance of the HIV epidemic. HIV surveillance occurs at maternal-child health clinics, but it is not known if pregnancy affects HIV incidence testing.We used the BED capture immunoassay (BED and an antibody avidity assay to test longitudinal samples from 51 HIV-infected Ugandan women infected with subtype A, C, D and intersubtype recombinant HIV who were enrolled in the HIVNET 012 trial (37 baseline samples collected near the time of delivery and 135 follow-up samples collected 3, 4 or 5 years later. Nineteen of 51 women were also pregnant at the time of one or more of the follow-up visits. The BED assay was performed according to the manufacturer's instructions. The avidity assay was performed using a Genetic Systems HIV-1/HIV-2 + O EIA using 0.1M diethylamine as the chaotropic agent.During the HIVNET 012 follow-up study, there was no difference in normalized optical density values (OD-n obtained with the BED assay or in the avidity test results (% when women were pregnant (n = 20 results compared to those obtained when women were not pregnant (n = 115; for BED: p = 0.9, generalized estimating equations model; for avidity: p = 0.7, Wilcoxon rank sum. In addition, BED and avidity results were almost exactly the same in longitudinal samples from the 18 women who were pregnant at only one study visit during the follow-up study (p = 0.6, paired t-test.These results from 51 Ugandan women suggest that any changes in the antibody response to HIV infection that occur during pregnancy are not sufficient to alter results obtained with the BED and avidity assays. Confirmation with larger studies and with other HIV subtypes is needed.

  15. Pregnancy does not affect HIV incidence test results obtained using the BED capture enzyme immunoassay or an antibody avidity assay.

    Science.gov (United States)

    Laeyendecker, Oliver; Church, Jessica D; Oliver, Amy E; Mwatha, Anthony; Owen, S Michele; Donnell, Deborah; Brookmeyer, Ron; Musoke, Philippa; Jackson, J Brooks; Guay, Laura; Nakabiito, Clemesia; Quinn, Thomas C; Eshleman, Susan H

    2010-10-11

    Accurate incidence estimates are needed for surveillance of the HIV epidemic. HIV surveillance occurs at maternal-child health clinics, but it is not known if pregnancy affects HIV incidence testing. We used the BED capture immunoassay (BED) and an antibody avidity assay to test longitudinal samples from 51 HIV-infected Ugandan women infected with subtype A, C, D and intersubtype recombinant HIV who were enrolled in the HIVNET 012 trial (37 baseline samples collected near the time of delivery and 135 follow-up samples collected 3, 4 or 5 years later). Nineteen of 51 women were also pregnant at the time of one or more of the follow-up visits. The BED assay was performed according to the manufacturer's instructions. The avidity assay was performed using a Genetic Systems HIV-1/HIV-2 + O EIA using 0.1M diethylamine as the chaotropic agent. During the HIVNET 012 follow-up study, there was no difference in normalized optical density values (OD-n) obtained with the BED assay or in the avidity test results (%) when women were pregnant (n = 20 results) compared to those obtained when women were not pregnant (n = 115; for BED: p = 0.9, generalized estimating equations model; for avidity: p = 0.7, Wilcoxon rank sum). In addition, BED and avidity results were almost exactly the same in longitudinal samples from the 18 women who were pregnant at only one study visit during the follow-up study (p = 0.6, paired t-test). These results from 51 Ugandan women suggest that any changes in the antibody response to HIV infection that occur during pregnancy are not sufficient to alter results obtained with the BED and avidity assays. Confirmation with larger studies and with other HIV subtypes is needed.

  16. Dengue Virus Evades AAV-Mediated Neutralizing Antibody Prophylaxis in Rhesus Monkeys.

    Science.gov (United States)

    Magnani, Diogo M; Ricciardi, Michael J; Bailey, Varian K; Gutman, Martin J; Pedreño-Lopez, Núria; Silveira, Cassia G T; Maxwell, Helen S; Domingues, Aline; Gonzalez-Nieto, Lucas; Su, Qin; Newman, Ruchi M; Pack, Melissa; Martins, Mauricio A; Martinez-Navio, José M; Fuchs, Sebastian P; Rakasz, Eva G; Allen, Todd M; Whitehead, Stephen S; Burton, Dennis R; Gao, Guangping; Desrosiers, Ronald C; Kallas, Esper G; Watkins, David I

    2017-10-04

    Development of vaccines against mosquito-borne Flaviviruses is complicated by the occurrence of antibody-dependent enhancement (ADE), which can increase disease severity. Long-term delivery of neutralizing antibodies (nAbs) has the potential to effectively block infection and represents an alternative to vaccination. The risk of ADE may be avoided by using prophylactic nAbs harboring amino acid mutations L234A and L235A (LALA) in the immunoglobulin G (IgG) constant region. Here, we used recombinant adeno-associated viruses (rAAVs) to deliver the anti-dengue virus 3 (DENV3) nAb P3D05. While the administration of rAAV-P3D05-rhesus immunoglobulin G1 (rhIgG1)-LALA to rhesus macaques engendered DENV3-neutralizing activity in serum, it did not prevent infection. The emergence of viremia following DENV3 challenge was delayed by 3-6 days in the rAAV-treated group, and replicating virus contained the envelope mutation K64R. This neutralization-resistant variant was also confirmed by virus outgrowth experiments in vitro. By delivering P3D05 with unmutated Fc sequences, we further demonstrated that DENV3 also evaded wild-type nAb prophylaxis, and serum viral loads appeared to be higher in the presence of low levels of unmutated P3D05-rhIgG1. Our study shows that a vectored approach for long-term delivery of nAbs with the LALA mutations is promising, but prophylaxis using a single nAb is likely insufficient at preventing DENV infection and replication. Copyright © 2017 The American Society of Gene and Cell Therapy. All rights reserved.

  17. Optimized AAV rh.10 Vectors That Partially Evade Neutralizing Antibodies during Hepatic Gene Transfer

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    Ruchita Selot

    2017-07-01

    Full Text Available Of the 12 common serotypes used for gene delivery applications, Adeno-associated virus (AAVrh.10 serotype has shown sustained hepatic transduction and has the lowest seropositivity in humans. We have evaluated if further modifications to AAVrh.10 at its phosphodegron like regions or predicted immunogenic epitopes could improve its hepatic gene transfer and immune evasion potential. Mutant AAVrh.10 vectors were generated by site directed mutagenesis of the predicted targets. These mutant vectors were first tested for their transduction efficiency in HeLa and HEK293T cells. The optimal vector was further evaluated for their cellular uptake, entry, and intracellular trafficking by quantitative PCR and time-lapse confocal microscopy. To evaluate their potential during hepatic gene therapy, C57BL/6 mice were administered with wild-type or optimal mutant AAVrh.10 and the luciferase transgene expression was documented by serial bioluminescence imaging at 14, 30, 45, and 72 days post-gene transfer. Their hepatic transduction was further verified by a quantitative PCR analysis of AAV copy number in the liver tissue. The optimal AAVrh.10 vector was further evaluated for their immune escape potential, in animals pre-immunized with human intravenous immunoglobulin. Our results demonstrate that a modified AAVrh.10 S671A vector had enhanced cellular entry (3.6 fold, migrate rapidly to the perinuclear region (1 vs. >2 h for wild type vectors in vitro, which further translates to modest increase in hepatic gene transfer efficiency in vivo. More importantly, the mutant AAVrh.10 vector was able to partially evade neutralizing antibodies (~27–64 fold in pre-immunized animals. The development of an AAV vector system that can escape the circulating neutralizing antibodies in the host will substantially widen the scope of gene therapy applications in humans.

  18. Optimized AAV rh.10 Vectors That Partially Evade Neutralizing Antibodies during Hepatic Gene Transfer.

    Science.gov (United States)

    Selot, Ruchita; Arumugam, Sathyathithan; Mary, Bertin; Cheemadan, Sabna; Jayandharan, Giridhara R

    2017-01-01

    Of the 12 common serotypes used for gene delivery applications, Adeno-associated virus (AAV)rh.10 serotype has shown sustained hepatic transduction and has the lowest seropositivity in humans. We have evaluated if further modifications to AAVrh.10 at its phosphodegron like regions or predicted immunogenic epitopes could improve its hepatic gene transfer and immune evasion potential. Mutant AAVrh.10 vectors were generated by site directed mutagenesis of the predicted targets. These mutant vectors were first tested for their transduction efficiency in HeLa and HEK293T cells. The optimal vector was further evaluated for their cellular uptake, entry, and intracellular trafficking by quantitative PCR and time-lapse confocal microscopy. To evaluate their potential during hepatic gene therapy, C57BL/6 mice were administered with wild-type or optimal mutant AAVrh.10 and the luciferase transgene expression was documented by serial bioluminescence imaging at 14, 30, 45, and 72 days post-gene transfer. Their hepatic transduction was further verified by a quantitative PCR analysis of AAV copy number in the liver tissue. The optimal AAVrh.10 vector was further evaluated for their immune escape potential, in animals pre-immunized with human intravenous immunoglobulin. Our results demonstrate that a modified AAVrh.10 S671A vector had enhanced cellular entry (3.6 fold), migrate rapidly to the perinuclear region (1 vs. >2 h for wild type vectors) in vitro, which further translates to modest increase in hepatic gene transfer efficiency in vivo. More importantly, the mutant AAVrh.10 vector was able to partially evade neutralizing antibodies (~27-64 fold) in pre-immunized animals. The development of an AAV vector system that can escape the circulating neutralizing antibodies in the host will substantially widen the scope of gene therapy applications in humans.

  19. Increased Avidity of the Sambucus nigra Lectin-Reactive Antibodies to the Thomsen-Friedenreich Antigen as a Potential Biomarker for Gastric Cancer

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    Oleg Kurtenkov

    2015-01-01

    Full Text Available Aim. To determine whether the naturally occurring Thomsen-Friedenreich (TF antigen-specific antibodies differ in avidity between cancer patients and controls to find a novel biomarker for stomach cancer. Methods. Serum samples were taken from patients with cancer and controls. The level of TF-specific antibodies and their sialylation were determined using ELISA with synthetic TF-polyacrylamide conjugate as antigen and sialic acid-specific Sambucus nigra agglutinin (SNA. The avidity was determined using ammonium thiocyanate as a chaotrope. Results. A significantly higher SNA lectin binding to anti-TF antibodies was found in cancer patients irrespective of disease stage. The avidity of only IgM TF-specific antibodies was significantly higher in cancer patients compared to controls. The SNA-positive anti-TF antibodies of cancer patients showed a significantly higher avidity, P<0.001. The sensitivity and specificity of this increase for gastric cancer were 73.53% and 73.08%, respectively, with a 73.2% diagnostic accuracy. The higher avidity of SNA-reactive anti-TF antibodies was associated with a benefit in survival of stage 3 cancer patients. Conclusion. The SNA-reactive TF-specific antibodies display a significantly higher avidity in gastric cancer patients compared to controls, which can be used as a potential serologic biomarker for gastric cancer. It appears that IgM is the main target responsible for the above changes.

  20. Hidden IgG Antibodies to the Tumor-Associated Thomsen-Friedenreich Antigen in Gastric Cancer Patients: Lectin Reactivity, Avidity, and Clinical Relevance

    Science.gov (United States)

    Kurtenkov, Oleg

    2017-01-01

    Natural antibodies to the tumor-associated Thomsen-Friedenreich antigen (TF) are related to tumor immunosurveillance and cancer patients' survival. Hidden IgG antibodies (HAbs) to TF, their lectin reactivity, avidity, and clinical relevance were studied. HAbs were present in cancer patients and controls. A decreased level of IgG HAbs was detected in cancer. The HAbs level positively correlated with the sialospecific SNA lectin binding in purified total IgG (tIgG) in donors and cancer patients, indicating that HAbs are higher sialylated. The avidity of anti-TF IgG in tIgG samples was lower in cancer patients (P = 0.025) while no difference in the avidity of free anti-TF IgG was established. A negative correlation between the avidity of anti-TF IgG in tIgG and SNA binding in both groups was observed (P IgG avidity in tIgG only in donors (P = 0.003). Changes in the level of HAbs and Abs avidity showed a rather good stage- and gender-dependent diagnostic accuracy. Cancer patients with a lower anti-TF IgG avidity in tIgG showed a benefit in survival. Thus the TF-specific HAbs represent a particular subset of anti-TF IgG that differ from free serum anti-TF IgG in SNA reactivity, avidity, diagnostic potential, and relation to survival. PMID:28316982

  1. High-Avidity and Potently Neutralizing Cross-Reactive Human Monoclonal Antibodies Derived from Secondary Dengue Virus Infection

    Science.gov (United States)

    Tsai, Wen-Yang; Lai, Chih-Yun; Wu, Yi-Chieh; Lin, Hong-En; Edwards, Carolyn; Jumnainsong, Amonrat; Kliks, Srisakul; Halstead, Scott; Mongkolsapaya, Juthathip; Screaton, Gavin R.

    2013-01-01

    The envelope (E) protein of dengue virus (DENV) is the major target of neutralizing antibodies (Abs) and vaccine development. Previous studies of human dengue-immune sera reported that a significant proportion of anti-E Abs, known as group-reactive (GR) Abs, were cross-reactive to all four DENV serotypes and to one or more other flaviviruses. Based on studies of mouse anti-E monoclonal antibodies (MAbs), GR MAbs were nonneutralizing or weakly neutralizing compared with type-specific MAbs; a GR response was thus not regarded as important for vaccine strategy. We investigated the epitopes, binding avidities, and neutralization potencies of 32 human GR anti-E MAbs. In addition to fusion loop (FL) residues in E protein domain II, human GR MAbs recognized an epitope involving both FL and bc loop residues in domain II. The neutralization potencies and binding avidities of GR MAbs derived from secondary DENV infection were stronger than those derived from primary infection. GR MAbs derived from primary DENV infection primarily blocked attachment, whereas those derived from secondary infection blocked DENV postattachment. Analysis of the repertoire of anti-E MAbs derived from patients with primary DENV infection revealed that the majority were GR, low-avidity, and weakly neutralizing MAbs, whereas those from secondary infection were primarily GR, high-avidity, and potently neutralizing MAbs. Our findings suggest that the weakly neutralizing GR anti-E Abs generated from primary DENV infection become potently neutralizing MAbs against the four serotypes after secondary infection. The observation that the dengue immune status of the host affects the quality of the cross-reactive Abs generated has implications for new strategies for DENV vaccination. PMID:24027331

  2. Characteristics of HPV-specific antibody responses induced by infection and vaccination: cross-reactivity, neutralizing activity, avidity and IgG subclasses.

    Science.gov (United States)

    Scherpenisse, Mirte; Schepp, Rutger M; Mollers, Madelief; Meijer, Chris J L M; Berbers, Guy A M; van der Klis, Fiona R M

    2013-01-01

    In order to assess HPV-specific IgG characteristics, we evaluated multiple aspects of the humoral antibody response that will provide insight in the HPV humoral immune response induced by HPV infection and vaccination. Cross-reactivity of HPV-specific antibodies induced by infection or vaccination was assessed with VLP16 or 18 inhibition using a VLP-based multiplex immunoassay (MIA) for HPV16, 18, 31, 33, 45, 52 and 58. HPV16/18 specific IgG1-4 subclasses and avidity were determined with the VLP-MIA in sera after HPV infection and after vaccination. Neutralizing antibodies were determined in a small subset of single-seropositive and multi-seropositive naturally derived antibodies. Naturally derived antibodies from single-positive sera were highly genotype-specific as homologue VLP-inhibition percentages varied between 78-94%. In multi-positive sera, cross-reactive antibodies were observed both within and between α7 and α9 species. After vaccination, cross-reactive antibodies were mainly species-specific. Avidity of vaccine-derived HPV-specific antibodies was 3 times higher than that of antibodies induced by HPV infection (pHPV infection and vaccination. In the small subset tested, the number of single-positive sera with neutralizing capacity was higher than of multi-positive sera. Naturally derived HPV-specific antibodies from single-positive samples showed different characteristics in terms of cross-reactivity and neutralizing capacity compared with antibodies from multi-positive sera. Post-vaccination, HPV antibody avidity was approximately 3 times higher than antibody avidity induced by HPV infection. Therefore, antibody avidity might be a potential surrogate of protection.

  3. Characteristics of HPV-specific antibody responses induced by infection and vaccination: cross-reactivity, neutralizing activity, avidity and IgG subclasses.

    Directory of Open Access Journals (Sweden)

    Mirte Scherpenisse

    Full Text Available OBJECTIVES: In order to assess HPV-specific IgG characteristics, we evaluated multiple aspects of the humoral antibody response that will provide insight in the HPV humoral immune response induced by HPV infection and vaccination. METHODS: Cross-reactivity of HPV-specific antibodies induced by infection or vaccination was assessed with VLP16 or 18 inhibition using a VLP-based multiplex immunoassay (MIA for HPV16, 18, 31, 33, 45, 52 and 58. HPV16/18 specific IgG1-4 subclasses and avidity were determined with the VLP-MIA in sera after HPV infection and after vaccination. Neutralizing antibodies were determined in a small subset of single-seropositive and multi-seropositive naturally derived antibodies. RESULTS: Naturally derived antibodies from single-positive sera were highly genotype-specific as homologue VLP-inhibition percentages varied between 78-94%. In multi-positive sera, cross-reactive antibodies were observed both within and between α7 and α9 species. After vaccination, cross-reactive antibodies were mainly species-specific. Avidity of vaccine-derived HPV-specific antibodies was 3 times higher than that of antibodies induced by HPV infection (p<0.0001. IgG1 and IgG3 were found to be the predominant subclasses observed after HPV infection and vaccination. In the small subset tested, the number of single-positive sera with neutralizing capacity was higher than of multi-positive sera. CONCLUSION: Naturally derived HPV-specific antibodies from single-positive samples showed different characteristics in terms of cross-reactivity and neutralizing capacity compared with antibodies from multi-positive sera. Post-vaccination, HPV antibody avidity was approximately 3 times higher than antibody avidity induced by HPV infection. Therefore, antibody avidity might be a potential surrogate of protection.

  4. Performance Evaluation of the VIDAS® Measles IgG Assay and Its Diagnostic Value for Measuring IgG Antibody Avidity in Measles Virus Infection

    Directory of Open Access Journals (Sweden)

    Julia Dina

    2016-08-01

    Full Text Available The objective of this study is primarily to compare the performance of the VIDAS® Measles immunoglobulin (IgG assay to that of two other serological assays using an immunoassay technique, Enzygnost® Anti-measles Virus/IgG (Siemens and Measles IgG CAPTURE EIA® (Microimmune. The sensitivity and the agreement of the VIDAS® Measles IgG assay compared to the Enzygnost® Anti-measles Virus/IgG assay and the Measles IgG CAPTURE EIA® assay are 100%, 97.2% and 99.0%, 98.4%, respectively. The very low number of negative sera for IgG antibodies does not allow calculation of specificity. As a secondary objective, we have evaluated the ability of the VIDAS® Measles IgG assay to measure anti-measles virus IgG antibody avidity with the help of the VIDAS® CMV IgG Avidity reagent, using 76 sera from subjects with measles and 238 other sera. Different groups of populations were analyzed. In the primary infection measles group, the mean IgG avidity index was 0.16 (range of 0.07 to 0.93 compared to 0.79 (range of 0.25 to 1 in the serum group positive for IgG antibodies and negative for IgM. These data allow to define a weak anti-measles virus IgG antibody avidity as an avidity index (AI < 0.3 and a strong avidity as an AI > 0.6. The VIDAS® Measles IgG assay has a performance equivalent to that of other available products. Its use, individual and quick, is well adapted to testing for anti-measles immunity in exposed subjects.

  5. Pentamerization of single-domain antibodies from phage libraries: a novel strategy for the rapid generation of high-avidity antibody reagents.

    Science.gov (United States)

    Zhang, Jianbing; Tanha, Jamshid; Hirama, Tomoko; Khieu, Nam Huan; To, Rebecca; Tong-Sevinc, Hong; Stone, Emily; Brisson, Jean Robert; MacKenzie, C Roger

    2004-01-02

    We describe a novel type of molecule in which single-domain antibodies (sdAbs) isolated from a nai;ve llama single domain antibody library are linked to an oligomerization domain to generate high-avidity, antigen-binding reagents. An sdAb is fused to the B-subunit of Escherichia coli verotoxin, or shiga-like toxin, which self-assembles to form a homopentamer and results in simultaneous sdAb pentamerization and introduction of avidity. Molecular modeling indicated that this fusion protein (PDB: 1OJF), termed pentabody, has structural flexibility for binding to surface-presented antigen. In the instance of an sdAb specific for a peptide antigen, pentamerization resulted in a dramatic increase in functional affinity for immobilized antigen. The pentabody was expressed in high yield in E.coli in a non-aggregated state, and exhibited excellent thermostability and protease resistance. This technology provides a relatively rapid means of generating novel antigen-binding molecules that bind strongly to immobilized antigen. It is expected that pentavalent sdAbs will have general applicability in proteomics, immunochemical staining, cancer diagnosis and other applications in which antigens are presented multivalently.

  6. Generation of polyclonal antibody with high avidity to rosuvastatin and its use in development of highly sensitive ELISA for determination of rosuvastatin in plasma

    Directory of Open Access Journals (Sweden)

    Al-Malaq Hamoud A

    2011-07-01

    Full Text Available Abstract In this study, a polyclonal antibody with high avidity and specificity to the potent hypocholesterolaemic agent rosuvastatin (ROS has been prepared and used in the development of highly sensitive enzyme-linked immunosorbent assay (ELISA for determination of ROS in plasma. ROS was coupled to keyhole limpt hemocyanin (KLH and bovine serum albumin (BSA using carbodiimide reagent. ROS-KLH conjugate was used for immunization of female 8-weeks old New Zealand white rabbits. The immune response of the rabbits was monitored by direct ELISA using ROS-BSA immobilized onto microwell plates as a solid phase. The rabbit that showed the highest antibody titer and avidity to ROS was scarified and its sera were collected. The IgG fraction was isolated and purified by avidity chromatography on protein A column. The purified antibody showed high avidity to ROS; IC50 = 0.4 ng/ml. The specificity of the antibody for ROS was evaluated by indirect ELISA using various competitors from the ROS-structural analogues and the therapeutic agents used with ROS in a combination therapy. The proposed ELISA involved a competitive binding reaction between ROS, in plasma sample, and the immobilized ROS-BSA for the binding sites on a limited amount of the anti-ROS antibody. The bound anti-ROS antibody was quantified with horseradish peroxidase-labeled second anti-rabbit IgG antibody (HRP-IgG and 3,3',5,5'-tetramethylbenzidine (TMB as a substrate for the peroxidase enzyme. The concentration of ROS in the sample was quantified by its ability to inhibit the binding of the anti-ROS antibody to the immobilized ROS-BSA and subsequently the color intensity in the assay wells. The assay enabled the determination of ROS in plasma at concentrations as low as 40 pg/ml.

  7. Development of purification processes for fully human bispecific antibodies based upon modification of protein A binding avidity.

    Science.gov (United States)

    Tustian, Andrew D; Endicott, Christine; Adams, Benjamin; Mattila, John; Bak, Hanne

    2016-01-01

    There is strong interest in the design of bispecific monoclonal antibodies (bsAbs) that can simultaneously bind 2 distinct targets or epitopes to achieve novel mechanisms of action and efficacy. Multiple bispecific formats have been proposed and are currently under development. Regeneron's bispecific technology is based upon a standard fully human IgG antibody in order to minimize immunogenicity and improve the pharmacokinetic profile. A single common light chain and 2 distinct heavy chains combine to form the bispecific molecule. One of the heavy chains contains a chimeric Fc sequence form (called Fc*) that ablates binding to Protein A via the constant region. As a result of co-expression of the 2 heavy chains and the common light chain, 3 products are created, 2 of which are homodimeric for the heavy chains and one that is the desired heterodimeric bispecific product. The Fc* sequence allows selective purification of the FcFc* bispecific product on commercially available affinity columns, due to intermediate binding affinity for Protein A compared to the high avidity FcFc heavy chain homodimer, or the weakly binding Fc*Fc* homodimer. This platform requires the use of Protein A chromatography in both a capture and polishing modality. Several challenges, including variable region Protein A binding, resin selection, selective elution optimization, and impacts upon subsequent non-affinity downstream unit operations, were addressed to create a robust and selective manufacturing process.

  8. The relationship between human T-lymphocyte subsets defined by monoclonal antibodies and by avidity differences to sheep erythrocytes

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Heron, I

    1982-01-01

    differences to sheep erythrocytes. Through a correlation was demonstrated between the T4+ (inducer) cells and the high avidity ("active") T cells and between the T8+ (suppressor) cells and low avidity T cells, these subsets were far from identical, and it is concluded that the application of monoclonal...

  9. High avidity antibodies to full-length VAR2CSA correlate with absence of placental malaria

    DEFF Research Database (Denmark)

    Tutterrow, Yeung Lo; Salanti, Ali; Avril, Marion

    2012-01-01

    VAR2CSA mediates sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, increasing the risk of poor pregnancy outcomes. Naturally acquired antibodies (Ab) to placental parasites at delivery have been associated with improved pregnancy outcomes, but Ab levels and how early i...

  10. Nasal Immunization Confers High Avidity Neutralizing Antibody Response and Immunity to Primary and Recurrent Genital Herpes in Guinea Pigs.

    Science.gov (United States)

    Persson, Josefine; Zhang, Yuan; Olafsdottir, Thorunn A; Thörn, Karolina; Cairns, Tina M; Wegmann, Frank; Sattentau, Quentin J; Eisenberg, Roselyn J; Cohen, Gary H; Harandi, Ali M

    2016-01-01

    Genital herpes is one of the most prevalent sexually transmitted infections in both the developing and developed world. Following infection, individuals experience life-long latency associated with sporadic ulcerative outbreaks. Despite many efforts, no vaccine has yet been licensed for human use. Herein, we demonstrated that nasal immunization with an adjuvanted HSV-2 gD envelope protein mounts significant protection to primary infection as well as the establishment of latency and recurrent genital herpes in guinea pigs. Nasal immunization was shown to elicit specific T cell proliferative and IFN-γ responses as well as systemic and vaginal gD-specific IgG antibody (Ab) responses. Furthermore, systemic IgG Abs displayed potent HSV-2 neutralizing properties and high avidity. By employing a competitive surface plasmon resonance (SPR) analysis combined with a battery of known gD-specific neutralizing monoclonal Abs (MAbs), we showed that nasal immunization generated IgG Abs directed to two major discontinuous neutralizing epitopes of gD. These results highlight the potential of nasal immunization with an adjuvanted HSV-2 envelope protein for induction of protective immunity to primary and recurrent genital herpes.

  11. Optimization of Unnicked β2-Glycoprotein I and High Avidity Anti-β2-Glycoprotein I Antibodies Isolation

    Directory of Open Access Journals (Sweden)

    Andrej Artenjak

    2014-01-01

    Full Text Available Patient biological material for isolation of β2-glycoprotein I (β2GPI and high avidity IgG anti-β2-glycoprotein I antibodies (HAv anti-β2GPI dictates its full utilization. The aim of our study was to evaluate/improve procedures for isolation of unnicked β2GPI and HAv aβ2GPI to gain unmodified proteins in higher yields/purity. Isolation of β2GPI from plasma was a stepwise procedure combining nonspecific and specific methods. For isolation of polyclonal HAv aβ2GPI affinity chromatographies with immobilized protein G and human β2GPI were used. The unknown protein found during isolation was identified by liquid chromatography electrospray ionization mass spectrometry and the nonredundant National Center for Biotechnology Information database. The average mass of the isolated unnicked purified β2GPI increased from 6.56 mg to 9.94 mg. In the optimized isolation procedure the high molecular weight protein (proteoglycan 4 was successfully separated from β2GPI in the 1st peaks with size exclusion chromatography. The average efficiency of the isolation procedure for polyclonal HAv anti-β2GPI from different matrixes was 13.8%, as determined by our in-house anti-β2GPI ELISA. We modified the in-house isolation and purification procedures of unnicked β2GPI and HAv anti-β2GPI, improving the purity of antigen and antibodies as well as increasing the number of tests routinely performed with the in-house ELISA by ~50%.

  12. Persistence and avidity maturation of antibodies to A(H1N1)pdm09 in healthcare workers following repeated annual vaccinations.

    Science.gov (United States)

    Eidem, Synnøve; Tete, Sarah M; Jul-Larsen, Åsne; Hoschler, Katja; Montomoli, Emanuele; Brokstad, Karl A; Cox, Rebecca J

    2015-08-07

    Healthcare workers are at increased risk of influenza infection through direct patient care, particularly during the early stages of a pandemic. Although influenza vaccination is widely recommended in Healthcare workers, data on long-term immunogenicity of vaccination in healthcare workers are lacking. The present study was designed to assess the persistence of the humoral response after pandemic vaccination as well as the impact of repeated annual vaccination in healthcare workers (n=24). Pandemic influenza vaccination resulted in a significant increase in haemagglutination inhibition (HI) antibody titers with 93-100% of subjects achieving protective titers 21-days post each of the three annual vaccinations. Seroprotective antibodies measured by HI, microneutralization and single radial hemolysis assays were present in 77-94% of healthcare workers 6 months post-vaccination. Repeated vaccination resulted in an increased duration of seroprotective antibodies with seroprotective titers increasing from 35-62% 12 months after 2009 pandemic vaccination to 50-75% 12 months after 2010 vaccination. Furthermore, repeated annual vaccination augmented the avidity of influenza-specific IgG antibodies. In conclusion, we have shown that A(H1N1)pdm09 vaccination induces high seroprotective titers that persist for at least 6 months. We demonstrate that repeated vaccination is beneficial to healthcare workers and results in further avidity maturation of vaccine-induced antibodies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. [The benefit from mumps virus IgG antibody avidity testing in the population with high vaccine coverage in the context of other serological methods for laboratory diagnosis of mumps and the current epidemiological].

    Science.gov (United States)

    Limberková, R; Smíšková, D; Havlíčková, M; Herrmannová, K; Lexová, P; Marešová, V

    2016-01-01

    Regular vaccination against mumps resulted in a significant reduction in epidemic mumps in the Czech Republic. However, mumps cases have recently shown an upward trend, even in the vaccinated population where a considerable proportion of cases have occurred. The aim of this study was to find out, by mumps virus IgG antibody avidity testing, whether the high incidence of mumps in the vaccinated population is a result of primary or secondary vaccine failure and whether the vaccinated differ from the naturally immunised in anamnestic antibody avidity. Given the problematic laboratory diagnosis of mumps in the population with high vaccination coverage, the informative value of the detected IgM, IgA, and IgG antibodies was also considered as well as the potential of antibody avidity testing for improving laboratory diagnosis from a single sample of blood, the most commonly analysed clinical material, in patients with suspected mumps. Sixty-four patients laboratory confirmed with mumps, whose vaccination status was known, were included in the study (groups 1 and 2). Other study groups were 30 healthy naturally immunised subjects (group 3) and 22 vaccinated children 2-4-years of age with no etiological link to the mumps virus (group 4). The avidity index (AI) was determined using the Siemens Enzygnost Anti-Mumps/IgG kit and 6M urea, able to induce the dissociation of antigen-antibody bonds proportionally to the antibody avidity. IgM, IgG, and IgA antibodies were tested using the Siemens Enzygnost Anti-Mumps/IgM and /IgG, and Mast Diagnostica Mastazyme Mumps IgA kits. The EPIDAT system served as the data source. The results showed that the mumps virus induces antibodies with a low AI after both vaccination, even recent, and natural immunisation. Antibodies with a high AI were only detected in convalescent sera of the vaccinated patients or in re-infected, naturally immunised persons, as a result of recent contact with the mumps virus. The comparison of the results of acute

  14. Development of a novel affinity chromatography resin for platform purification of bispecific antibodies with modified protein a binding avidity.

    Science.gov (United States)

    Tustian, Andrew D; Laurin, Linus; Ihre, Henrik; Tran, Travis; Stairs, Robert; Bak, Hanne

    2018-02-21

    There is strong interest in the production of bispecific monoclonal antibodies that can simultaneously bind two distinct targets or epitopes to achieve novel mechanisms of action and efficacy. Regeneron's bispecific technology, based upon a standard IgG, consists of a heterodimer of two different heavy chains, and a common light chain. Co-expression of two heavy chains leads to the formation of two parental IgG impurities, the removal of which is facilitated by a dipeptide substitution in the Fc portion of one of the heavy chains that ablates Fc Protein A binding. Therefore the affinity capture (Protein A) step of the purification process must perform both bulk capture and high resolution of these mAb impurities, a task current commercially available resins are not designed for. Resolution can be further impaired by the ability of Protein A to bind some antibodies in the variable region of the heavy chain (V H ). This paper details development of a novel Protein A resin. This resin combines an alkali stable ligand with a base matrix exhibiting excellent mass transfer properties to allow high capacity single step capture and resolution of bispecific antibodies with high yields. The developed resin, named MabSelect SuRe™ pcc, is implemented in GMP production processes for several bispecific antibodies. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

  15. Hõimupäevad

    Index Scriptorium Estoniae

    2003-01-01

    Avatakse EKA Saamimaa uurimisreisi temaatikal põhinev näitus "Nelja tuule retk", ungari foto- ja etnograafi Laszlo Kunkovacsi fotonäitus "Ungari karjusekultuur". ERMis on avatud ülevaatenäitus "EKA soomeugri joonised ERMis". Hõimupäevade muusikaprojektidest, mis leiavad seekord aset koostöös "Jazzkaare" projektiga "Piirideta Põhjala"

  16. Human immunodeficiency virus type 1 Brazilian subtype B variant showed an increasing avidity of the anti-V3 antibodies over time compared to the subtype B US/European strain in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Casseb Jorge

    2004-01-01

    Full Text Available The Brazilian variant of human immunodeficiency virus type 1 (HIV-1 subtype B, (serotype B"-GWGR, has a tryptophan replacing the proline in position 328 the HIV-1 envelope. A longer median time period from infection to acquired immunodeficiency syndrome (AIDS for serotype B (B"-GWGR infected subjects compared to the B-GPGR US/European strain was reported. In a cohort study, in São Paulo city, 10 B"-GWGR patients had a statistically significant increased avidity of the anti-V3 antibodies, from 79% ± 33% to 85% ± 75%, versus from 48% ± 59% to 32% ± 17% for the 10 B-GPGR subjects (p = 0.02. The T CD4+ cells showed a mean increase of + 0.45 cells/month for the B-GPGR subjects and for B"-GWGR the slope was + 1.24 cells/month (p = 0.06, for 62 and 55 months of follow up, respectively. RNA plasma viral load decreased from 3.98 ± 1.75 to 2.16 ± 1.54 log10 in the B"-GWGR group while B-GPGR patients showed one log10 reduction in viral load from 4.09 ± 0.38 to 3.17 ± 1.47 log10 over time (p = 0.23, with a decreasing slope of 0.0042 ± log10,/month and 0.0080 ± log10/month, for B-GPGR and B"-GWGR patients, respectively (p = 0.53. Neither group presented any AIDS defining events during the study, according to Center for Diseases Control criteria. Although the sample size is small, these results may indicate that differences in the pathogenicity of the 2 HIV-1 B serotypes which co-circulate in Brazil may be correlated to the avidity of anti-V3 antibodies.

  17. Alum and squalene-oil-in-water emulsion enhance the titer and avidity of anti-Aβ antibodies induced by multimeric protein antigen (1-11)E2, preserving the Igg1-skewed isotype distribution.

    Science.gov (United States)

    Mantile, Francesca; Trovato, Maria; Santoni, Andrea; Barba, Pasquale; Ottonello, Simone; De Berardinis, Piergiuseppe; Prisco, Antonella

    2014-01-01

    The development of active immunotherapy for Alzheimer's disease (AD) requires the identification of immunogens that can ensure a high titer antibody response toward Aβ, while minimizing the risks of adverse reactions. Multimeric protein (1-11)E2 induces a robust and persistent antibody response to Aβ in mice, when formulated in Freund's adjuvant. The goal of this translational study was to evaluate the immunogenicity of (1-11)E2 formulated in alum (Alhydrogel 2%), or in a squalene oil-in-water emulsion (AddaVax), or without adjuvant. A IgG1-skewed isotype distribution was observed for the anti-Aβ antibodies generated in mice immunized with either the non-adjuvanted or the adjuvanted vaccine, indicating that (1-11)E2 induces a Th2-like response in all tested conditions. Both Alhydrogel 2% and AddaVax enhanced the titer and avidity of the anti-Aβ response elicited by (1-11)E2. We conclude that (1-11)E2 is a promising candidate for anti-Aβ immunization protocols that include alum or squalene-oil-in-water emulsion, or no adjuvant.

  18. Alum and squalene-oil-in-water emulsion enhance the titer and avidity of anti-Aβ antibodies induced by multimeric protein antigen (1-11E2, preserving the Igg1-skewed isotype distribution.

    Directory of Open Access Journals (Sweden)

    Francesca Mantile

    Full Text Available The development of active immunotherapy for Alzheimer's disease (AD requires the identification of immunogens that can ensure a high titer antibody response toward Aβ, while minimizing the risks of adverse reactions. Multimeric protein (1-11E2 induces a robust and persistent antibody response to Aβ in mice, when formulated in Freund's adjuvant. The goal of this translational study was to evaluate the immunogenicity of (1-11E2 formulated in alum (Alhydrogel 2%, or in a squalene oil-in-water emulsion (AddaVax, or without adjuvant. A IgG1-skewed isotype distribution was observed for the anti-Aβ antibodies generated in mice immunized with either the non-adjuvanted or the adjuvanted vaccine, indicating that (1-11E2 induces a Th2-like response in all tested conditions. Both Alhydrogel 2% and AddaVax enhanced the titer and avidity of the anti-Aβ response elicited by (1-11E2. We conclude that (1-11E2 is a promising candidate for anti-Aβ immunization protocols that include alum or squalene-oil-in-water emulsion, or no adjuvant.

  19. Immunoglobulin M indirect-fluorescent antibody test for the diagnosis of acute toxoplasmosis during pregnancy in the avidity era: A 14-year experience at the Tuscany Reference Center for Infectious Diseases in Pregnancy, Florence, Italy.

    Science.gov (United States)

    Trotta, Michele; Borchi, Beatrice; Zammarchi, Lorenzo; Sterrantino, Gaetana; Brogi, Michela; Kiros, Seble Tekle; Lorini, Chiara; Bonaccorsi, Guglielmo; Colao, Maria Grazia; Bartoloni, Alessandro

    2016-12-01

    The aim of this study was to evaluate immunoglobulin M indirect-fluorescent antibody test (IgM IFAT) for the diagnosis of acute or chronic Toxoplasma infection in pregnancy. Pregnant women with suspected acute toxoplasmosis referred to the Tuscany Reference Center for Infectious Diseases in Pregnancy during the period 1998-2012 were retrospectively enrolled. All women were tested with a panel of serological tests, including enzyme-linked immunosorbent assay for IgG avidity and IgM IFAT. On the basis of anamnestic, clinical, and serological criteria, pregnant women were classified into three groups: recently infected (RI), latently infected (LI), and doubtful latently infected (DLI). Patients classified as DLI were excluded from the analysis. The association between IgM IFAT (positive or negative) and the diagnosis of infection (acute or chronic) was assessed. Positive predictive value and negative predictive value of the IgM IFAT were calculated. A total of 810 pregnant women were enrolled in the study: 302 in the RI group and 508 in the LI group. Fifty-two women classified as DLI were excluded. IgM IFAT was positive in 172 out of 302 (56.9%) pregnant women in the RI group and in 29 out of 508 (5.7%) in the LI group. The positive predictive value and negative predictive value of IgM IFAT in predicting RI was 85.6% and 78.6%, respectively. IgM IFAT has reasonable sensitivity and specificity in diagnosing recent infection and, mostly in case of borderline avidity test, could be considered as a further aid for an accurate diagnosis of acute toxoplasmosis in pregnancy. © 2016 Japan Society of Obstetrics and Gynecology.

  20. Avidity Of Anti-Naja Haje Antivenin In Relation To In Vivo And In ...

    African Journals Online (AJOL)

    Avidity, which is a measure of the bonding strength between antigens and antibodies, becomes an important medical parameter in many aspects of therapeutic and diagnostic purposes. In the present investigation, we studied the relationship between the avidity and the in vivo and in vitro activity of 18 samples of anti-Naja ...

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

    Science.gov (United States)

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

    2007-08-01

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

  2. Neutralizing antibody responses against autologous and heterologous viruses in acute versus chronic human immunodeficiency virus (HIV) infection: evidence for a constraint on the ability of HIV to completely evade neutralizing antibody responses.

    Science.gov (United States)

    Deeks, Steven G; Schweighardt, Becky; Wrin, Terri; Galovich, Justin; Hoh, Rebecca; Sinclair, Elizabeth; Hunt, Peter; McCune, Joseph M; Martin, Jeffrey N; Petropoulos, Christos J; Hecht, Frederick M

    2006-06-01

    Acute human immunodeficiency virus (HIV) infection is associated with the rapid development of neutralization escape mutations. The degree to which viral evolution persists in chronic infection has not been well characterized, nor is it clear if all patients develop high-level neutralization antibody escape. We therefore measured neutralizing antibody responses against autologous and heterologous viruses in a cohort of acutely and chronically infected subjects (n = 65). Neutralizing antibody responses against both autologous virus and heterologous viruses were lower among individuals with acute infection than among those with chronic infection. Among chronically infected individuals, there was a negative correlation between the level of neutralizing antibodies against autologous virus and the level of viremia. In contrast, there was a positive correlation between the level of neutralizing antibodies against a panel of heterologous viruses and the level of viremia. Viral evolution, as defined by the presence of higher neutralizing titers directed against earlier viruses than against contemporaneous viruses, was evident for subjects with recent infection but absent for those with chronic infection. In summary, neutralizing antibody responses against contemporaneous autologous viruses are absent in early HIV infection but can be detected at low levels in chronic infection, particularly among those controlling HIV in the absence of therapy. HIV replication either directly or indirectly drives the production of increasing levels of antibodies that cross-neutralize heterologous primary isolates. Collectively, these observations indicate that although HIV continuously drives the production of neutralizing antibodies, there may be limits to the capacity of the virus to evolve continuously in response to these antibodies. These observations also suggest that the neutralizing antibody response may contribute to the long-term control of HIV in some patients while protecting

  3. Interdiction of a Markovian evader

    Energy Technology Data Exchange (ETDEWEB)

    Hagberg, Aric [Los Alamos National Laboratory; Izraelevitz, David [Los Alamos National Laboratory; Pan, Feng [Los Alamos National Laboratory; Gutfraind, Alexander [CORNELL UNIV

    2008-01-01

    Network interdiction is a combinatorial optimization problem on an activity network arising in a number of important security-related applications. It is classically formulated as a bilevel maximin problem representing an 'interdictor' and an 'evader'. The evader tries to move from a source node to the target node along the shortest or safest path while the interdictor attempts to frustrate this motion by cutting edges or nodes. The interdiction objective is to find the optimal set of edges to cut given that there is a finite interdiction budget and the interdictor must move first. We reformulate the interdiction problem for stochastic evaders by introducing a model in which the evader follows a Markovian random walk guided by the least-cost path to the target. This model can represent incomplete knowledge about the evader and the graph as well as partial interdiction. We formulate the optimization problem for this model and show how, by exploiting topological ordering of the nodes, one can achieve an order-of-magnitude speedup in computing the objective function. We also introduce an evader-motion-based heuristic that can significantly improve solution quality by providing a global view of the network to approximation methods.

  4. Inherited sodium avid states.

    Science.gov (United States)

    Achard, Jean-Michel; Hadchouel, Juliette; Faure, Sébastien; Jeunemaitre, Xavier

    2006-04-01

    Several familial forms of hypertension have been identified, in which the mendelian pattern of inheritance indicated that hypertension results from the alteration of a single gene. This short review focuses on those rare monogenic disorders characterized by a low-renin profile. This common feature reflects that the causative mutations responsible for these disorders all result in an excessive sodium reabsorption in the aldosterone-dependent nephron. Low-renin familial hypertensions with hypokalemia encompass familial hyperaldosteronisms, in which aldosterone levels are elevated, and familial pseudohyperaldosteronisms, mimicking aldosteronism despite appropriately suppressed aldosterone levels. In these disorders, the avidity of the kidney for sodium is because of dysregulated sodium reabsorption through the epithelial sodium channel ENaC and results in potassium wasting and metabolic alcalosis. Familial hypertension with hyperkalemia is a specific syndrome resulting from mutations in at least 3 different genes, among which 2 have been recently identified. These genes encode members of a new family of kinase, the WNK kinases, involved in the regulation of sodium and potassium excretion by the kidney.

  5. Avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii: immunological marker for acute recent toxoplasmosis Avidez de anticorpos IgG anti-antígeno de secreção e excreção de Toxoplasma gondii: marcador imunológico de toxoplasmose aguda recente

    Directory of Open Access Journals (Sweden)

    Patrícia Regina Barboza Araújo

    2008-04-01

    Full Text Available Detection of anti-toxoplasma IgM antibodies has frequently been used as a serological marker for diagnosing recently acquired toxoplasmosis. However, the persistence of these antibodies in some patients has complicated the interpretation of serological results when toxoplasmosis is suspected. The purpose of the present study was to evaluate the avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii by means of immunoblot, to establish a profile for acute recent infection in a single serum sample and confirm the presence of residual IgM antibodies obtained in automated assays. When we evaluated the avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii by means of immunoblot, we observed phase-specific reactivity, i.e. cases of acute recent toxoplasmosis presented low avidity and cases of non-acute recent toxoplasmosis presented high avidity towards the 30kDa protein fraction, which probably corresponds to the SAG-1 surface antigen. Our results suggest that the avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii is an important immunological marker for distinguishing between recent infections and for determining the presence of residual IgM antibodies obtained from automated assays.A detecção de anticorpos IgM antitoxoplasma tem sido freqüentemente utilizada como marcador sorológico para o diagnóstico de toxoplasmose de aquisição recente. Entretanto, a persistência destes anticorpos em alguns pacientes tem complicado a interpretação dos resultados sorológicos quando a toxoplasmose é suspeitada. A proposta deste trabalho foi avaliar a avidez de anticorpos IgG contra antígenos de secreção e excreção de Toxoplasma gondii por immunoblot, para estabelecer um perfil de infecção recente aguda em uma única amostra de soro e confirmar a presença de anticorpos IgM residuais obtidos nos testes automatizados. Quando a avidez de anticorpos IgG contra ant

  6. [Seroprevalence and detection of primary infection by cytomegalovirus with IgG avidity test during the first quarter of pregnancy].

    Science.gov (United States)

    González-García, Conne L; Reyes-Méndez, Miguel A; Ortega-Pierres, Luz E; Rodríguez-Sánchez, Adriana P; Sandoval-Guido, Verónica; Sereno-Coló, José A

    2014-01-01

    To determine the seroprevalence and detection of primary infection by cytomegalovirus (CMV) with immunoglobulin G (IgG) avidity test during the first quarter of pregnancy in the General Hospital in Morelia, Michoacan. A total of 177 patients were studied employing a modified Elisa test using a chemiluminescent microparticle immunoassay (CMIA) for the detection of CMV antibodies (IgG and immunoglobulin M [IgM]), and IgG avidity. 90.4% were positive for IgG, and of these, 2.3% were also reactive for IgM, and in this group the IgG avidity test reported low avidity for 1.1% and higher avidity in the same percentage. 9.6% were seronegative. Similarity was found with published studies in Mexico. Health professionals should know the clinical algorithms for diagnosis and proper management of CMV infection using the IgG avidity test.

  7. Evader Interdiction and Collateral Damage

    Energy Technology Data Exchange (ETDEWEB)

    Gutfraind, Alexander [Los Alamos National Laboratory

    2011-01-01

    In network interdiction problems, evaders (hostile agents or data packets) are moving through a network towards their targets and we wish to choose sensor placement locations in order to intercept them before they reach their destinations. Sensor locations should be chosen economically, balancing security gains with cost, including the inconvenience sensors inflict upon innocent travelers. We give optimal sensor allocation algorithms for several classes of special graphs and hardness and optimal approximation results for general graphs, including for deterministic or Markov chain-based and oblivious or reactive evaders. In a similar-sounding but much different problem setting posed by [10] where the innocent travelers can also be reactive, we again give optimal algorithms for special cases and hardness and (essentially) optimal approximation results on general graphs.

  8. Serological IgG avidity test for ocular toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Suresh S

    2012-01-01

    Full Text Available Subramaniam Suresh1, Saidin Nor-Masniwati1, Muhd Nor Nor-Idahriani1, Wan-Hitam Wan-Hazabbah1, Mohamed Zeehaida2, Embong Zunaina11Department of Ophthalmology, 2Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, MalaysiaBackground: The purpose of this study was to evaluate the immunoglobulin (Ig G avidity of serological toxoplasmosis testing in patients with ocular inflammation and to determine the clinical manifestations of ocular toxoplasmosis.Methods: A retrospective review of all patients presenting with ocular inflammation to the Hospital Universiti Sains Malaysia, Kelantan, Malaysia between 2005 and 2009 was undertaken. Visual acuity, clinical manifestations at presentation, toxoplasmosis antibody testing, and treatment records were analyzed.Results: A total of 130 patients with ocular inflammation were reviewed retrospectively. The patients had a mean age of 38.41 (standard deviation 19.24, range 6–83 years. Seventy-one patients (54.6% were found to be seropositive, of whom five (3.8% were both IgG and IgM positive (suggestive of recently acquired ocular toxoplasmosis while one (0.8% showed IgG avidity ≤40% (suggestive of recently acquired ocular toxoplasmosis and 65 patients (50.0% showed IgG avidity >40% (suggestive of reactivation of toxoplasmosis infection. Chorioretinal scarring as an ocular manifestation was significantly more common in patients with seropositive toxoplasmosis (P = 0.036. Eighteen patients (13.8% were diagnosed as having recent and/or active ocular toxoplasmosis based on clinical manifestations and serological testing.Conclusion: Ocular toxoplasmosis is a clinical diagnosis, but specific toxoplasmosis antibody testing helps to support the diagnosis and to differentiate between reactivation of infection and recently acquired ocular toxoplasmosis.Keywords: ocular toxoplasmosis, chorioretinal scar, toxoplasmosis antibody, IgG avidity test

  9. Evaluation of the Toxoplasma gondii IgG Avidity request and results in a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Serdar Güngör

    2014-06-01

    Full Text Available Objectives: Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii (T. gondii with various clinical outcomes. Serological tests determining IgG and IgM produced against T. gondii are widely used for laboratory diagnosis of the infection. IgG avidity test identifying the infection initiation in diagnosis is required when specific IgM antibodies are not able to be detected in early period of infection, IgM antibodies in patients with reactivation are not increased or especially in pregnant with IgM positivity. In this study, it was aimed to evaluate avidity test results and to determine the algorithmic place of this test in T. gondii infection. Methods: In this study, avidity test results requested from all of the clinics and services from serology laboratory in 1 January 2013-31 December 2013 were included. Totally, 84 anti-T. gondii IgG avidity was requested. The avidity value was researched by ELISA method using anti-T. gondii IgG avidity kit in patients included in this study. Anti-T. gondii IgG and IgM antibody tests were performed by ELISA method using commercial kit. Results: 61, 13 and 2 requests were evaluated as high avidity 72.6%, low avidity 15.5% and intermediate value 2.4%, respectively, while 8 requests were unnecessary. Conclusion: It was concluded that primarily anti-T. gondii IgG and IgM tests should be performed in suspicious cases in terms of toxoplasmosis and the IgG avidity tests should be requested from only suitable cases after the evaluation of the test results according to clinic table of the patients and/or the week of pregnancy. J Clin Exp Invest 2014; 5 (2: 246-249

  10. Contribution of IgG avidity and PCR for the early diagnosis of toxoplasmosis in pregnant women from the North-Eastern region of Algeria.

    Science.gov (United States)

    Berredjem, Hajira; Aouras, Hayette; Benlaifa, Meriem; Becheker, Imène; Djebar, Mohamed Reda

    2017-09-01

    Acute toxoplasmosis in pregnant women presents a high risk of Toxoplasma transmission to the fetus. Early diagnosis is difficult, especially when serological testing for IgG/IgM antibodies fail to differentiate between a recent and a past infection. In this case, we rely on IgG avidity or PCR assays. The aim of this study was to compare conventional ELISA and IgG avidity, with PCR using B1 and P30 primers for the early diagnosis of toxoplasmosis in pregnant women. Sera were collected from 143 pregnant women and measured by ELISA for anti-Toxoplasma IgG, IgM, IgA and IgG avidity. DNA was extracted from 57 peripheral blood and 14 amniotic fluid samples for PCR amplification. A total of 57 out 143 women were seropositive: 30 (52.6%) were IgG+/IgM- and 27 (43.8%) were IgG+/IgM+; IgA antibodies were positive in 7 (12.2%) cases. IgG avidity was low in 9 women suggesting an acute infection; 3 women presented an intermediate avidity. PCR detected Toxoplasma DNA in 9 women presenting low avidity and was negative for the intermediate avidity cases. PCR combined to avidity IgG performed better than ELISA IgG, IgM and/or IgA assays alone. PCR was useful in the case of intermediate avidity.

  11. Serodiagnosis of Toxoplasmosis: The effect of measurement of IgG avidity in pregnant women in Rabat in Morocco.

    Science.gov (United States)

    Laboudi, Majda; Sadak, Abderrahim

    2017-08-01

    The diagnosis of Toxoplasmosis in pregnant women during the early first trimester of pregnancy is very important for preventing congenital infection of the fetus; it will not only prevent the risk of transmitting the infection to the fetus but it will also enable to give these women a preventive treatment. In this study, the avidity test was performed on pregnant women during their first prenatal visit at the National Institute of Hygiene in Rabat, Morocco. One hundred and twenty-eight sera samples were collected from 128 pregnant women between August 2015 and June 2016; these women were chosen retrospectively and were in their first four months of pregnancy. The samples were screened using the specific anti-Toxoplasma IgG and IgM antibodies and were subjected to an IgG avidity test. After the serological screening, only 54 women (42.4%) were tested positive for IgG antibodies and five women (3.9%) were tested positive for both anti-Toxoplasma IgG and IgM antibodies. Four IgM-negative women had low-avidity antibodies. However, none of the IgG-avidity test had detected low-avidity antibodies in the five IgM-positive women; three women (60%) had high-avidity antibodies, indicating that the infection was acquired in the distant past. The avidity test is a helpful tool to exclude a recently acquired toxoplasmosis infection within IgM-positive serum samples in pregnant women during their first trimester of pregnancy. Thus, allowing to perform an appropriate therapeutic intervention. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Contribution of IgG avidity and PCR for the early diagnosis of ...

    African Journals Online (AJOL)

    Background: Acute toxoplasmosis in pregnant women presents a high risk of Toxoplasma transmission to the fetus. Early diagnosis is difficult, especially when serological testing for IgG/IgM antibodies fail to differentiate between a recent and a past infection. In this case, we rely on IgG avidity or PCR assays. Objectives: The ...

  13. Optimal interdiction of unreactive Markovian evaders

    Energy Technology Data Exchange (ETDEWEB)

    Hagberg, Aric [Los Alamos National Laboratory; Pan, Feng [Los Alamos National Laboratory; Gutfraind, Alex [CORNELL UNIV.

    2009-01-01

    The interdiction problem arises in a variety of areas including military logistics, infectious disease control, and counter-terrorism. In the typical formulation of network interdiction. the task of the interdictor is to find a set of edges in a weighted network such that the removal of those edges would increase the cost to an evader of traveling on a path through the network. Our work is motivated by cases in which the evader has incomplete information about the network or lacks planning time or computational power, e.g. when authorities set up roadblocks to catch bank robbers, the criminals do not know all the roadblock locations or the best path to use for their escape. We introduce a model of network interdiction in which the motion of one or more evaders is described by Markov processes on a network and the evaders are assumed not to react to interdiction decisions. The interdiction objective is to find a node or set. of size at most B, that maximizes the probability of capturing the evaders. We prove that similar to the classical formulation this interdiction problem is NP-hard. But unlike the classical problem our interdiction problem is submodular and the optimal solution can be approximated within 1-lie using a greedy algorithm. Additionally. we exploit submodularity to introduce a priority evaluation strategy that speeds up the greedy algorithm by orders of magnitude. Taken together the results bring closer the goal of finding realistic solutions to the interdiction problem on global-scale networks.

  14. Skulptuuripäevad Pärnus

    Index Scriptorium Estoniae

    2003-01-01

    4.-15. VIII Pärnus Vallikääru aasal 3. rahvusvahelised skulptuuripäevad "Pärnu positiivne märk". Osalevad Serge Samyn (Prantsusmaa), Kestutis Lanauskaټ (Leedu), Asa Hauksdottir (Island), Meeland Sepp, Toomas Kuusing, Toomas Altnurme, Rait Pärg (korraldaja). Lastele vanuses 7-15 avatud töötuba juhendab Eneken Maripuu

  15. Maakunsti päevad Rakveres

    Index Scriptorium Estoniae

    2000-01-01

    5.-10. VI Rakvere tammikus rahvusvahelised maakunsti päevad. Korraldaja Anne Kokkov. Rakvere muuseumis lõppes naivistliku kunstniku Berta Mändla näitus "Berta jutustab". Muuseumi teisi üritusi. Richard Sagritsa ateljees Karepal väljapanek kunstniku ja tema kaasaegsete loomingust.

  16. 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 ...

  17. Becoming a Reader: Significant Social Influences on Avid Book Readers

    Science.gov (United States)

    Merga, Margaret K.

    2017-01-01

    Understanding how social influences can foster avid book reader identification is a key research goal that warrants further investigation beyond a limited early-years lens. The author's 2015 International Study of Avid Book Readers (ISABR) explored, as one of its key research questions, the influence positive social agents can have on avid book…

  18. IgG avidity test for the diagnosis of acute Toxoplasma gondii infection in early pregnancy.

    Science.gov (United States)

    Pour Abolghasem, Shabnam; Bonyadi, Mohammad Reza; Babaloo, Zohre; Porhasan, Abolfazl; Nagili, Behroz; Gardashkhani, Omid Ali; Salehi, Parviz; Hashemi, Mohammad; Varshoghi, Mojtaba; Gaffari, Gafar Olade

    2011-12-01

    Toxoplasmosis is well known as an important infection in pregnant women. Although many serologic methods are available, diagnosis of early Toxoplasmosis may be extremely difficult. To detect the Toxoplasma IgG antibodies developed at the early stage of infection in pregnant women. 225 pregnant women, who were in the 2nd to 4th month of their pregnancy, enrolled in this study. Anti-toxoplasma IgG, IgM and IgG avidity were evaluated by ELISA method. The patients were categorized into three groups as follows: Group A, 124 cases; IgG+, IgM+, 55.1%; group B, 99 cases; IgG+, IgM-, 44%; and group C, 2 cases; IgG -, IgM +, 0.9%. Fifty five percent of the pregnant women had positive IgG and IgM among which 7.1% had low avidity which revealed an active infection in the pregnant women. In the current study, 44% of pregnant women had positive IgG and negative IgM, all of which had high avidity, which is an indication that in our population the level of toxoplasmosis infection is high and most women have had contacts with this parasite before pregnancy. In this study, the low avidity test was 7.1% showing that the occurrence of toxoplasmosis infection is still a serious issue. Observation of 45.8% high avidity among group A suggests that either IgM has a high half-life or there is a false positive IgM as a result of rheumatologic disorders. Therefore, avidity test is important in predicting maternal toxoplasmosis which is of value in disease treatment.

  19. Persistent Low Toxoplasma IgG Avidity Is Common in Pregnancy: Experience from Antenatal Testing in Norway.

    Science.gov (United States)

    Findal, Gry; Stray-Pedersen, Babill; Holter, Ellen K; Berge, Tone; Jenum, Pål A

    2015-01-01

    The parasite Toxoplasma gondii might harm the fetus if a woman is infected during pregnancy. IgG seroconversion and significant increase in IgG antibody amount in pregnancy indicates maternal infection. Presence of toxoplasma immunoglobulin M (IgM), immunoglobulin G (IgG) and low IgG avidity in a single serum sample indicates possible maternal infection, but positive toxoplasma IgM and low IgG avidity may persist for months and even years. We aimed to evaluate avidity development during pregnancy in a retrospective study. Serial blood samples from 176 pregnant women admitted to Oslo University Hospital 1993-2013 for amniocentesis because of suspected toxoplasma infection were included. Data were obtained from journals and laboratory records. The avidity method used was based on Platelia Toxo IgG assay. Mean maternal age at first serology was 29.9 years (SD 5.2, range 18-42). In 37 (21%) women only the avidity increased from low to high in toxoplasma serology should ideally be collected in early pregnancy and if stable values of toxoplasma IgM and low IgG-avidity are detected in a second sample after three to four weeks, the need for amniocentesis can be questioned.

  20. Single hemagglutinin mutations that alter both antigenicity and receptor binding avidity influence influenza virus antigenic clustering.

    Science.gov (United States)

    Li, Yang; Bostick, David L; Sullivan, Colleen B; Myers, Jaclyn L; Griesemer, Sara B; Stgeorge, Kirsten; Plotkin, Joshua B; Hensley, Scott E

    2013-09-01

    The hemagglutination inhibition (HAI) assay is the primary measurement used for identifying antigenically novel influenza virus strains. HAI assays measure the amount of reference sera required to prevent virus binding to red blood cells. Receptor binding avidities of viral strains are not usually taken into account when interpreting these assays. Here, we created antigenic maps of human H3N2 viruses that computationally account for variation in viral receptor binding avidities. These new antigenic maps differ qualitatively from conventional antigenic maps based on HAI measurements alone. We experimentally focused on an antigenic cluster associated with a single N145K hemagglutinin (HA) substitution that occurred between 1992 and 1995. Reverse-genetics experiments demonstrated that the N145K HA mutation increases viral receptor binding avidity. Enzyme-linked immunosorbent assays (ELISA) revealed that the N145K HA mutation does not prevent antibody binding; rather, viruses possessing this mutation escape antisera in HAI assays simply by attaching to cells more efficiently. Unexpectedly, we found an asymmetric antigenic effect of the N145K HA mutation. Once H3N2 viruses acquired K145, an epitope involving amino acid 145 became antigenically dominant. Antisera raised against an H3N2 strain possessing K145 had reduced reactivity to H3N2 strains possessing N145. Thus, individual mutations in HA can influence antigenic groupings of strains by altering receptor binding avidity and by changing the dominance of antibody responses. Our results indicate that it will be important to account for variation in viral receptor binding avidity when performing antigenic analyses in order to identify genuine antigenic differences among influenza virus variants.

  1. Characterization of binding mode of action of a blocking anti-platelet-derived growth factor (PDGF)-B monoclonal antibody, MOR8457, reveals conformational flexibility and avidity needed for PDGF-BB to bind PDGF receptor-β.

    Science.gov (United States)

    Kuai, Jun; Mosyak, Lidia; Brooks, Jon; Cain, Michael; Carven, Gregory J; Ogawa, Shinji; Ishino, Tetsuya; Tam, May; Lavallie, Edward R; Yang, Zhiyong; Ponsel, Dirk; Rauchenberger, Robert; Arch, Robert; Pullen, Nick

    2015-03-17

    Platelet derived growth factor-BB (PDGF-BB) is an important mitogen and cell survival factor during development. PDGF-BB binds PDGF receptor-β (PDGFRβ) to trigger receptor dimerization and tyrosine kinase activation. We present the pharmacological and biophysical characterization of a blocking PDGF-BB monoclonal antibody, MOR8457, and contrast this to PDGFRβ. MOR8457 binds to PDGF-BB with high affinity and selectivity, and prevents PDGF-BB induced cell proliferation competitively and with high potency. The structural characterization of the MOR8457-PDGF-BB complex indicates that MOR8457 binds with a 2:1 stoichiometry, but that binding of a single MOR8457 moiety is sufficient to prevent binding to PDGFRβ. Comparison of the MOR8457-PDGF-BB structure with that of the PDGFRβ-PDGF-BB complex suggested the potential reason for this was a substantial bending and twisting of PDGF-BB in the MOR8457 structure, relative to the structures of PDGF-BB alone, bound to a PDGF-BB aptamer or PDGFRβ, which makes it nonpermissive for PDGFRβ binding. These biochemical and structural data offer insights into the permissive structure of PDGF-BB needed for agonism as well as strategies for developing specific PDGF ligand antagonists.

  2. How eukaryotic filamentous pathogens evade plant recognition.

    Science.gov (United States)

    Oliveira-Garcia, Ely; Valent, Barbara

    2015-08-01

    Plant pathogenic fungi and oomycetes employ sophisticated mechanisms for evading host recognition. After host penetration, many fungi and oomycetes establish a biotrophic interaction. It is assumed that different strategies employed by these pathogens to avoid triggering host defence responses, including establishment of biotrophic interfacial layers between the pathogen and host, masking of invading hyphae and active suppression of host defence mechanisms, are essential for a biotrophic parasitic lifestyle. During the infection process, filamentous plant pathogens secrete various effectors, which are hypothesized to be involved in facilitating effective host infection. Live-cell imaging of fungi and oomycetes secreting fluorescently labeled effector proteins as well as functional characterization of the components of biotrophic interfaces have led to the recent progress in understanding how eukaryotic filamentous pathogens evade plant recognition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Improved testing of recent HIV-1 infections with the BioRad avidity assay compared to the limiting antigen avidity assay and BED Capture enzyme immunoassay: evaluation using reference sample panels from the German Seroconverter Cohort.

    Science.gov (United States)

    Hauser, Andrea; Santos-Hoevener, Claudia; Meixenberger, Karolin; Zimmermann, Ruth; Somogyi, Sybille; Fiedler, Stefan; Hofmann, Alexandra; Bartmeyer, Barbara; Jansen, Klaus; Hamouda, Osamah; Bannert, Norbert; Kuecherer, Claudia

    2014-01-01

    The variety and limitations of current laboratory methods for estimating HIV-incidence has driven attempts to improve and standardize the performance of serological 'Tests for Recent HIV-Infections' (TRI). Primary and follow-up HIV-1 positive plasma samples from individuals with well-defined dates of infection collected as part of the German Seroconverter Cohort provided specimens highly suitable for use in comparing the performance of three TRIs: the AWARE™ BED™ EIA HIV-1 Incidence test (BED-CEIA), Genetic systems HIV-1/HIV-2 Plus O EIA antibody avidity-based assay (BioRad Avidity) and Sedia™ HIV-1 LAg Avidity EIA (LAg Avidity). The evaluation panel included 180 specimens: 44 from antiretroviral (ARV)-naïve individuals with recently acquired HIV-infection (≤ 130 days; 25 B and 19 non-B subtypes) and 136 from long-term (>12 months) infected individuals [101 ARV-naïve subtype B, 16 non-B subtypes, 14 ARV-treated individuals, 5 slow progressors (SLP)]. For long-term infected, ARV-naïve individuals the false recent rates (FRR) of both the BioRad and LAg Avidity assays were 2% (2/101 for subtype B) and 6% (1/16 for subtype 'non-B'), while the FRR of the BED-CEIA was 7% (7/101 for subtype B) and 25% (4/16 for subtype 'non-B') (all p>0.05). Misclassification of ARV-treated individuals and SLP was rare by LAg (1/14, 0/5) and BioRad Avidity assays (2/14, 1/5) but more frequent by BED-CEIA (5/14, 3/5). Among recently-infected individuals (subtype B), 60% (15/25) were correctly classified by BED-CEIA, 88% (22/25) by BioRad Avidity and significantly fewer by LAg (48%, 12/25) compared to BioRad Avidity (p = 0.005) with a higher true-recency rate among non-B infections for all assays. This study using well-characterized specimens demonstrated lower FRRs for both avidity methods than with the BED-CEIA. For recently infected individuals the BioRad Avidity assay was shown to give the most accurate results.

  4. Improved testing of recent HIV-1 infections with the BioRad avidity assay compared to the limiting antigen avidity assay and BED Capture enzyme immunoassay: evaluation using reference sample panels from the German Seroconverter Cohort.

    Directory of Open Access Journals (Sweden)

    Andrea Hauser

    Full Text Available BACKGROUND: The variety and limitations of current laboratory methods for estimating HIV-incidence has driven attempts to improve and standardize the performance of serological 'Tests for Recent HIV-Infections' (TRI. Primary and follow-up HIV-1 positive plasma samples from individuals with well-defined dates of infection collected as part of the German Seroconverter Cohort provided specimens highly suitable for use in comparing the performance of three TRIs: the AWARE™ BED™ EIA HIV-1 Incidence test (BED-CEIA, Genetic systems HIV-1/HIV-2 Plus O EIA antibody avidity-based assay (BioRad Avidity and Sedia™ HIV-1 LAg Avidity EIA (LAg Avidity. METHODS: The evaluation panel included 180 specimens: 44 from antiretroviral (ARV-naïve individuals with recently acquired HIV-infection (≤ 130 days; 25 B and 19 non-B subtypes and 136 from long-term (>12 months infected individuals [101 ARV-naïve subtype B, 16 non-B subtypes, 14 ARV-treated individuals, 5 slow progressors (SLP]. RESULTS: For long-term infected, ARV-naïve individuals the false recent rates (FRR of both the BioRad and LAg Avidity assays were 2% (2/101 for subtype B and 6% (1/16 for subtype 'non-B', while the FRR of the BED-CEIA was 7% (7/101 for subtype B and 25% (4/16 for subtype 'non-B' (all p>0.05. Misclassification of ARV-treated individuals and SLP was rare by LAg (1/14, 0/5 and BioRad Avidity assays (2/14, 1/5 but more frequent by BED-CEIA (5/14, 3/5. Among recently-infected individuals (subtype B, 60% (15/25 were correctly classified by BED-CEIA, 88% (22/25 by BioRad Avidity and significantly fewer by LAg (48%, 12/25 compared to BioRad Avidity (p = 0.005 with a higher true-recency rate among non-B infections for all assays. CONCLUSIONS: This study using well-characterized specimens demonstrated lower FRRs for both avidity methods than with the BED-CEIA. For recently infected individuals the BioRad Avidity assay was shown to give the most accurate results.

  5. IgG avidity assay: a tool for excluding acute toxoplasmosis in prolonged IgM titer sera from pregnant women.

    Science.gov (United States)

    Emelia, O; Rahana, A R; Mohamad Firdaus, A; Cheng, H S; Nursyairah, M S; Fatinah, A S; Azmawati, M N; Siti, N A M; Aisah, M Y

    2014-12-01

    An accurate diagnosis for toxoplasmosis is crucial for pregnant women as this infection may lead to severe sequelae in the fetus. The value of IgG avidity assay as a tool to determine acute and chronic toxoplasmosis during pregnancy was evaluated in Universiti Kebangsaan Malaysia Medical Centre (UKMMC). In this study, 281 serum samples from 281 pregnant women in various trimesters were collected. These samples were assayed using specific anti-Toxoplasma IgM and IgG antibodies, followed by IgG avidity test. The overall seroprevalence of toxoplasmosis in pregnant women was 35.2% (33.5% for anti-Toxoplasma IgG and 1.8% for both anti-Toxoplasma IgG and IgM antibodies). Of 5 (1.8%) serum samples positive for IgM ELISA, 4 had high-avidity antibodies, suggesting past infection and one sample with borderline avidity index. Two samples with low avidity were from IgM negative serum samples. The IgG avidity assay exhibited an excellent specificity of 97.6% and a negative predictive value (NPV) of 95.6%. The study also demonstrated no significant correlation between avidity indexes of the sera with IgG (r=0.12, p=0.24) and IgM (r=-0.00, p=0.98), suggesting the complementary needs of the two tests for a better diagnosis outcome. These findings highlight the usefulness of IgG avidity assay in excluding a recently acquired toxoplasmosis infection in IgM-positive serum sample.

  6. Are Avid Readers Lurking in Your Language Arts Classroom? Myths of the Avid Adolescent Reader

    Science.gov (United States)

    Wilson, Nance S.; Kelley, Michelle J.

    2010-01-01

    This article describes a pilot study conducted with 10 identified avid adolescent readers who completed the Adolescent Motivation to Read Profile (AMRP) (Pitcher, Albright, DeLaney, Walker, Seunarienesingh, & Moggie, 2007) that includes both a survey to determine students' self-concept and value of reading and an interview that sheds light on what…

  7. Trafficking of high avidity HER-2/neu-specific T cells into HER-2/neu-expressing tumors after depletion of effector/memory-like regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Vivian L Weiss

    Full Text Available Cancer vaccines are designed to activate and enhance cancer-antigen-targeted T cells that are suppressed through multiple mechanisms of immune tolerance in cancer-bearing hosts. T regulatory cell (Treg suppression of tumor-specific T cells is one barrier to effective immunization. A second mechanism is the deletion of high avidity tumor-specific T cells, which leaves a less effective low avidity tumor specific T cell repertoire available for activation by vaccines. Treg depleting agents including low dose cyclophosphamide (Cy and antibodies that deplete CD25-expressing Tregs have been used with limited success to enhance the potency of tumor-specific vaccines. In addition, few studies have evaluated mechanisms that activate low avidity cancer antigen-specific T cells. Therefore, we developed high and low avidity HER-2/neu-specific TCR transgenic mouse colonies specific for the same HER-2/neu epitope to define the tolerance mechanisms that specifically affect high versus low avidity tumor-specific T cells.High and low avidity CD8(+ T cell receptor (TCR transgenic mice specific for the breast cancer antigen HER-2/neu (neu were developed to provide a purified source of naïve, tumor-specific T cells that can be used to study tolerance mechanisms. Adoptive transfer studies into tolerant FVB/N-derived HER-2/neu transgenic (neu-N mice demonstrated that high avidity, but not low avidity, neu-specific T cells are inhibited by Tregs as the dominant tolerizing mechanism. High avidity T cells persisted, produced IFNγ, trafficked into tumors, and lysed tumors after adoptive transfer into mice treated with a neu-specific vaccine and low dose Cy to deplete Tregs. Analysis of Treg subsets revealed a Cy-sensitive CD4(+Foxp3(+CD25(low tumor-seeking migratory phenotype, characteristic of effector/memory Tregs, and capable of high avidity T cell suppression.Depletion of CD25(low Tregs allows activation of tumor-clearing high avidity T cells. Thus, the development

  8. An Approach to Detect Malicious Behaviors by Evading Stalling Code

    OpenAIRE

    Chao Dai; Xiaonan Liu; Chao You; Yichi Zhang; Jianmin Pang

    2012-01-01

    Since malwares contain stalling codes, malicious behaviors can’t be detected in emulated analysis environment. This paper proposes an approach to detect malicious behaviors by evade stalling codes. First, we executed a malware in the emulated analysis environment, and saved every executed instruction in a trace file; Second, we began to detect stalling codes with the trace file, and constructed stalling code evasive points; At last, we executed the malware again and evade stalling codes with ...

  9. Comparison of Toxoplasma gondii IgG avidity Architect and Vidas assays with the estimated date of infection in pregnant women.

    Science.gov (United States)

    Smets, Aurélie; Fauchier, Thomas; Michel, Grégory; Marty, Pierre; Pomares, Christelle

    2016-01-01

    A maternal Toxoplasma gondii infection during pregnancy is a risk for congenital infection through maternal-fetal transplacental transmission. Estimation of the date of infection is of the utmost importance for management and treatment recommendations. In this setting, IgG avidity has been shown to be useful as high avidity rules out an infection dating less than 4 months. The estimated date of infection can also be obtained by the ratio of T. gondii IgG titers measured by the Vidas (bioMérieux) assay versus T. gondii IgG titers measured by the Architect (Abbott Laboratories) test, together with T. gondii IgM and IgA antibody responses. In this study, using 117 serum samples from pregnant women, we compared the IgG avidity values obtained by Architect and Vidas with the presumed date of T. gondii infection established by the T. gondii IgG ratio of IgG Vidas and IgG Architect plus the IgM and IgA results. To date, IgG avidity Vidas seems to exhibit better performance than Architect. For both assays, gray zone results were most likely obtained from patients infected more than 4 months before sampling. These data should be taken into account for a possible reconsideration of the interpretation of avidity results in the gray zone. © A. Smets et al., published by EDP Sciences, 2016.

  10. Comparison of Toxoplasma gondii IgG avidity Architect and Vidas assays with the estimated date of infection in pregnant women

    Directory of Open Access Journals (Sweden)

    Smets Aurélie

    2016-01-01

    Full Text Available A maternal Toxoplasma gondii infection during pregnancy is a risk for congenital infection through maternal-fetal transplacental transmission. Estimation of the date of infection is of the utmost importance for management and treatment recommendations. In this setting, IgG avidity has been shown to be useful as high avidity rules out an infection dating less than 4 months. The estimated date of infection can also be obtained by the ratio of T. gondii IgG titers measured by the Vidas (bioMérieux assay versus T. gondii IgG titers measured by the Architect (Abbott Laboratories test, together with T. gondii IgM and IgA antibody responses. In this study, using 117 serum samples from pregnant women, we compared the IgG avidity values obtained by Architect and Vidas with the presumed date of T. gondii infection established by the T. gondii IgG ratio of IgG Vidas and IgG Architect plus the IgM and IgA results. To date, IgG avidity Vidas seems to exhibit better performance than Architect. For both assays, gray zone results were most likely obtained from patients infected more than 4 months before sampling. These data should be taken into account for a possible reconsideration of the interpretation of avidity results in the gray zone.

  11. GM-CSF DNA: an adjuvant for higher avidity IgG, rectal IgA, and increased protection against the acute phase of a SHIV-89.6P challenge by a DNA/MVA immunodeficiency virus vaccine.

    Science.gov (United States)

    Lai, Lilin; Vödrös, Dalma; Kozlowski, Pamela A; Montefiori, David C; Wilson, Robert L; Akerstrom, Vicki L; Chennareddi, Lakshmi; Yu, Tianwei; Kannanganat, Sunil; Ofielu, Lazarus; Villinger, Francois; Wyatt, Linda S; Moss, Bernard; Amara, Rama Rao; Robinson, Harriet L

    2007-12-05

    Single intradermal or intramuscular inoculations of GM-CSF DNA with the DNA prime for a simian-human immunodeficiency virus (SHIV)-89.6 vaccine, which consists of DNA priming followed by modified vaccinia Ankara (MVA) boosting, increased protection of both the blood and intestines against the acute phase of an intrarectal SHIV-89.6P challenge. GM-CSF appeared to contribute to protection by enhancing two antibody responses: the avidity maturation of anti-Env IgG in blood (p=oranti-viral IgA in rectal secretions (p<0.01). The avidity of anti-Env IgG showed strong correlations with protection both pre and post challenge. Animals with the highest avidity anti-Env Ab had 1000-fold reductions in peak viremia over those with the lowest avidity anti-Env Ab. The enhanced IgA response was associated with the best protection, but did not achieve significance.

  12. Testing the ability of viral haemorrhagic septicaemia virus to evade the protective immune response induced in rainbow trout by DNA vaccination

    DEFF Research Database (Denmark)

    Sepulveda, Dagoberto; Lorenzen, Niels

    2013-01-01

    glycoprotein, the only surface protein of the VHSV, has been successful as an experimental prophylactic treatment against this disease, because it induces a strong innate (interferon) and adaptive (cellular and humoral) immune response. However, since RNA viruses are known to possess high variability......, this work aims to evaluate whether VHSV is able to evade the protective immune response induced by the DNA vaccination. Earlier studies have demonstrated that VHSV can evade the neutralizing effect of monoclonal antibodies by mutations in the glycoprotein gene. One approach of the present study is therefore...

  13. Development of Fully Automated Determination of Marker-Specific Immunoglobulin G (IgG) Avidity Based on the Avidity Competition Assay Format: Application for Abbott Architect Cytomegalovirus and Toxo IgG Avidity Assays▿ †

    Science.gov (United States)

    Curdt, Ingo; Praast, Gerald; Sickinger, Eva; Schultess, Jan; Herold, Iris; Braun, Hans Bertram; Bernhardt, Stephanie; Maine, Gregory T.; Smith, Darwin D.; Hsu, Stephen; Christ, Heike M.; Pucci, Dominick; Hausmann, Michael; Herzogenrath, Jörg

    2009-01-01

    Determination of the avidity of immunoglobulin G (IgG) directed against a specific marker has become an established diagnostic tool for identifying or excluding acute infections with pathogens. A novel assay format termed AVIcomp (avidity competition based on mass action) circumventing the conventional chaotropic format has been developed for determination of the avidity of marker-specific IgG in patient specimens. Its applications for cytomegalovirus (CMV) and Toxoplasma gondii are presented. Specific high-avidity IgG from the patient specimen is selectively blocked using a soluble antigen in a sample pretreatment reagent, and the amount of remaining specific low-avidity IgG is determined relative to that in an untreated control. The comparison of the conventional chaotropic format, represented by the Radim CMV IgG Avidity assay, and the newly developed AVIcomp method, as exemplified by the Architect CMV IgG Avidity assay, on blood drawn within 4 months after seroconversion revealed a sensitivity of 100% (97.3% by an alternative calculation) for the AVIcomp format versus 87.5% (75.7% by an alternative calculation) for the chaotropic avidity assay. The specificity on 312 CMV IgG reactive and CMV IgM nonreactive specimens from pregnant women was 100% for the AVIcomp assay and 99.7% for the conventional avidity assay. The Architect Toxo IgG Avidity assay showed an agreement of 97.2% with the bioMérieux Vidas Toxo IgG Avidity Assay employing chaotropic reagents. These performance data suggest that the AVIcomp format shows superior sensitivity and equivalent specificity for the determination of IgG avidity to assays based on the chaotropic method and that the AVIcomp format may also be applicable to other disease states. PMID:19129411

  14. Täna algavad Eesti Muusika Päevad

    Index Scriptorium Estoniae

    2004-01-01

    Eesti Muusika Päevade raames toimunud üritustest 21. aprillini: ERSO sümfooniakontserdist Estonia kontserdisaalis, Jüri Reinvere radiofoonilise ooperi "Vastaskallas" esiettekandest Tallinna Linnateatri Hobuveski saalis, kontserdist Kunstihoone Vabaduse väljakul (esitusel Urmas Sisaski uus "Tähistaeva tsükkel" - "Eesti rahvataevas"), lastekontserdist "Kodumaine viis" Estonia kontserdisaalis

  15. Effects of Potassium Iodide on Low Avid Immunological Reactions ...

    African Journals Online (AJOL)

    Results: i) KI like BA or CS showed hemagglutination. ii) C‑mediated hemolysis was inhibited in presence of KI. iii) C‑mediated lysis of S. typhi was partially enhanced by KI showing reduced number of colonies; iv) while lysis of candida was reduced. Conclusions: KI increases avidity of some immune reactions including ...

  16. Avidity Studies in Anisakis simplex-Associated Allergic Diseases

    Directory of Open Access Journals (Sweden)

    Carmen Cuéllar

    2013-01-01

    Full Text Available Gastroallergic anisakiasis (GAA and Anisakis-sensitization-associated chronic urticaria (CU+ differ with respect to specific IgE levels. We hypothesised different immunoglobulin avidities in both entities as well as their dependence on TI and fish consumption. 16 patients with GAA and 17 patients with CU+ were included, and immunoglobulin levels were analysed by CAP (Phadia. IgE and IgG avidity indexes (AvIgE and AvIgG, resp. were also determined. IgG avidity was higher in GAA than in CU+ (P=0.035, whereas there was a tendency to lower IgE avidity in GAA (P=0.095. When analysing all patients, AvIgG was positively correlated with specific IgE, IgG, and IgG4 as well as total IgE (Rho between 0.66 and 0.71; P<0.002, but AvIgE was negatively correlated with specific IgE (Rho −0.57; P<0.001, specific IgG4 (Rho −0.38; P<0.05, and total IgE (Rho 0.66; P<0.001. In GAA, weekly fish consumption was positively associated with AvIgE (Rho 0.51; P=0.05. A multivariate regression showed that time interval was the main explaining factor for AvIgE in GAA. We could show a differential behaviour of immunoglobulin isotype avidities in both entities and their dependence on fish-eating habits as well as on the time elapsed to the last parasitic episode.

  17. IL-4 and IL-13 mediated down-regulation of CD8 expression levels can dampen anti-viral CD8⁺ T cell avidity following HIV-1 recombinant pox viral vaccination.

    Science.gov (United States)

    Wijesundara, Danushka K; Jackson, Ronald J; Tscharke, David C; Ranasinghe, Charani

    2013-09-23

    We have shown that mucosal HIV-1 recombinant pox viral vaccination can induce high, avidity HIV-specific CD8(+) T cells with reduced interleukin (IL)-4 and IL-13 expression compared to, systemic vaccine delivery. In the current study how these cytokines act to regulate anti-viral CD8(+) T, cell avidity following HIV-1 recombinant pox viral prime-boost vaccination was investigated. Out of a panel of T cell avidity markers tested, only CD8 expression levels were found to be enhanced on, KdGag197-205 (HIV)-specific CD8(+) T cells obtained from IL-13(-/-), IL-4(-/-) and signal transducer and, activator of transcription of 6 (STAT6)(-/-) mice compared to wild-type (WT) controls following, vaccination. Elevated CD8 expression levels in this instance also correlated with polyfunctionality, (interferon (IFN)-γ, tumour necorsis factor (TNF)-α and IL-2 production) and the avidity of HIVspecific CD8(+) T cells. Furthermore, mucosal vaccination and vaccination with the novel adjuvanted IL-13 inhibitor (i.e. IL-13Rα2) vaccines significantly enhanced CD8 expression levels on HIV-specific CD8(+), T cells, which correlated with avidity. Using anti-CD8 antibodies that blocked CD8 availability on CD8(+), T cells, it was established that CD8 played an important role in increasing HIV-specific CD8(+) T cell avidity and polyfunctionality in IL-4(-/-), IL-13(-/-) and STAT6(-/-) mice compared to WT controls, following vaccination. Collectively, our data demonstrate that IL-4 and IL-13 dampen CD8 expression levels on anti-viral CD8(+) T cells, which can down-regulate anti-viral CD8(+) T cell avidity and, polyfunctionality following HIV-1 recombinant pox viral vaccination. These findings can be exploited to, design more efficacious vaccines not only against HIV-1, but many chronic infections where high, avidity CD8(+) T cells help protection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. AVID: An integrative framework for discovering functional relationships among proteins

    Directory of Open Access Journals (Sweden)

    Keating Amy E

    2005-06-01

    Full Text Available Abstract Background Determining the functions of uncharacterized proteins is one of the most pressing problems in the post-genomic era. Large scale protein-protein interaction assays, global mRNA expression analyses and systematic protein localization studies provide experimental information that can be used for this purpose. The data from such experiments contain many false positives and false negatives, but can be processed using computational methods to provide reliable information about protein-protein relationships and protein function. An outstanding and important goal is to predict detailed functional annotation for all uncharacterized proteins that is reliable enough to effectively guide experiments. Results We present AVID, a computational method that uses a multi-stage learning framework to integrate experimental results with sequence information, generating networks reflecting functional similarities among proteins. We illustrate use of the networks by making predictions of detailed Gene Ontology (GO annotations in three categories: molecular function, biological process, and cellular component. Applied to the yeast Saccharomyces cerevisiae, AVID provides 37,451 pair-wise functional linkages between 4,191 proteins. These relationships are ~65–78% accurate, as assessed by cross-validation testing. Assignments of highly detailed functional descriptors to proteins, based on the networks, are estimated to be ~67% accurate for GO categories describing molecular function and cellular component and ~52% accurate for terms describing biological process. The predictions cover 1,490 proteins with no previous annotation in GO and also assign more detailed functions to many proteins annotated only with less descriptive terms. Predictions made by AVID are largely distinct from those made by other methods. Out of 37,451 predicted pair-wise relationships, the greatest number shared in common with another method is 3,413. Conclusion AVID provides

  19. Impact of wall shear stress and ligand avidity on binding of anti-CD146-coated nanoparticles to murine tumor endothelium under flow

    Science.gov (United States)

    Ryschich, Eduard

    2015-01-01

    The endothelial phenotype of tumor blood vessels differs from the liver and forms an important base for endothelium-specific targeting by antibody-coated nanoparticles. Although differences of shear stress and ligand avidity can modulate the nanoparticle binding to endothelium, these mechanisms are still poorly studied. This study analyzed the binding of antibody-coated nanoparticles to tumor and liver endothelium under controlled flow conditions and verified this binding in tumor models in vivo. Binding of anti-CD146-coated nanoparticles, but not of antibody was significantly reduced under increased wall shear stress and the degree of nanoparticle binding correlated with the avidity of the coating. The intravascular wall shear stress favors nanoparticle binding at the site of higher avidity of endothelial epitope which additionally promotes the selectivity to tumor endothelium. After intravenous application in vivo, pegylated self-coated nanoparticles showed specific binding to tumor endothelium, whereas the nanoparticle binding to the liver endothelium was very low. This study provides a rationale that selective binding of mAb-coated nanoparticles to tumor endothelium is achieved by two factors: higher expression of endothelial epitope and higher nanoparticle shearing from liver endothelium. The combination of endothelial marker targeting and the use of shear stress-controlled nanoparticle capture can be used for selective intratumoral drug delivery. PMID:26503468

  20. Antithyroglobulin antibody

    Science.gov (United States)

    Thyroglobulin antibody; Thyroiditis - thyroglobulin antibody; Hypothyroidism - thyroglobulin antibody; Thyroiditis - thyroglobulin antibody; Graves disease - thyroglobulin antibody; Underactive thyroid - thyroglobulin antibody

  1. Mechanisms behind functional avidity maturation in T cells

    DEFF Research Database (Denmark)

    von Essen, Marina Rode; Kongsbak, Martin; Geisler, Carsten

    2012-01-01

    During an immune response antigen-primed B-cells increase their antigen responsiveness by affinity maturation mediated by somatic hypermutation of the genes encoding the antigen-specific B-cell receptor (BCR) and by selection of higher-affinity B cell clones. Unlike the BCR, the T-cell receptor...... (TCR) cannot undergo affinity maturation. Nevertheless, antigen-primed T cells significantly increase their antigen responsiveness compared to antigen-inexperienced (naïve) T cells in a process called functional avidity maturation. This paper covers studies that describe differences in T-cell antigen...... responsiveness during T-cell differentiation along with examples of the mechanisms behind functional avidity maturation in T cells....

  2. Pyoverdine, the Major Siderophore in Pseudomonas aeruginosa, Evades NGAL Recognition

    Directory of Open Access Journals (Sweden)

    Mary E. Peek

    2012-01-01

    Full Text Available Pseudomonas aeruginosa is the most common pathogen that persists in the cystic fibrosis lungs. Bacteria such as P. aeruginosa secrete siderophores (iron-chelating molecules and the host limits bacterial growth by producing neutrophil-gelatinase-associated lipocalin (NGAL that specifically scavenges bacterial siderophores, therefore preventing bacteria from establishing infection. P. aeruginosa produces a major siderophore known as pyoverdine, found to be important for bacterial virulence and biofilm development. We report that pyoverdine did not bind to NGAL, as measured by tryptophan fluorescence quenching, while enterobactin bound to NGAL effectively causing a strong response. The experimental data indicate that pyoverdine evades NGAL recognition. We then employed a molecular modeling approach to simulate the binding of pyoverdine to human NGAL using NGAL’s published crystal structures. The docking of pyoverdine to NGAL predicted nine different docking positions; however, neither apo- nor ferric forms of pyoverdine docked into the ligand-binding site in the calyx of NGAL where siderophores are known to bind. The molecular modeling results offer structural support that pyoverdine does not bind to NGAL, confirming the results obtained in the tryptophan quenching assay. The data suggest that pyoverdine is a stealth siderophore that evades NGAL recognition allowing P. aeruginosa to establish chronic infections in CF lungs.

  3. T cell avidity and tumor recognition: implications and therapeutic strategies

    Directory of Open Access Journals (Sweden)

    Roszkowski Jeffrey J

    2005-09-01

    Full Text Available Abstract In the last two decades, great advances have been made studying the immune response to human tumors. The identification of protein antigens from cancer cells and better techniques for eliciting antigen specific T cell responses in vitro and in vivo have led to improved understanding of tumor recognition by T cells. Yet, much remains to be learned about the intricate details of T cell – tumor cell interactions. Though the strength of interaction between T cell and target is thought to be a key factor influencing the T cell response, investigations of T cell avidity, T cell receptor (TCR affinity for peptide-MHC complex, and the recognition of peptide on antigen presenting targets or tumor cells reveal complex relationships. Coincident with these investigations, therapeutic strategies have been developed to enhance tumor recognition using antigens with altered peptide structures and T cells modified by the introduction of new antigen binding receptor molecules. The profound effects of these strategies on T cell – tumor interactions and the clinical implications of these effects are of interest to both scientists and clinicians. In recent years, the focus of much of our work has been the avidity and effector characteristics of tumor reactive T cells. Here we review concepts and current results in the field, and the implications of therapeutic strategies using altered antigens and altered effector T cells.

  4. Contribution of IgG avidity and PCR for the early diagnosis of ...

    African Journals Online (AJOL)

    2017-09-03

    Sep 3, 2017 ... an intermediate avidity. PCR detected Toxoplasma DNA in 9 women presenting low avidity and was negative for the intermediate .... DNA extracted from the tachyzoites of T. gondii-RH strain. (Institut Pasteur ..... Table 3: Rates of Toxoplasma acute infection among the study pregnant women. Diagnosis.

  5. Back-action Evading Measurements of a Nanomechanical Resonator

    Science.gov (United States)

    Ndukum, Tchefor; Rocheleau, Tristan; Schwab, Keith

    2010-03-01

    By driving a 5GHz superconducting, co-planar waveguide (CPW) resonator coupled to a radio-frequency nanomechanical resonator with both red and blue-detuned, phase coherent microwave signals, we have demonstrated amplifier noise back-action evading (BAE) detection of one quadrature of nanomechanical motion. With this quantum non-demolition (QND) scheme we have shown precise measurements of a single motional quadrature with additive measurement noise of 4 times the zero point amplitude, and a reduction in sensitivity to injected measurement noise of a factor of 43 in comparison to a single tone, non-BAE measurement. By increasing the CPW frequency to 7.5GHz, quadrupling the coupling strength and improving the (internal) quality factor of the CPW, we expect to be able to demonstrate sensitivity to one quadrature with additive measurement noise below the zero-point level, a necessary ingredient to produce and measure squeezed states of motion.

  6. Back action evading quantum limited measurements of a nanomechanical resonator

    Science.gov (United States)

    Ndukum, Tchefor; Rocheleau, Tristan; Hertzberg, Jared; Schwab, Keith

    2009-03-01

    By driving a 5GHz superconducting, co-planar waveguide (CPW) resonator coupled to a radio-frequency nanomechanical resonator with both red- and blue-detuned, phase coherent microwave signals, we demonstrate amplifier noise back action evading(BAE) detection of one quadrature of nanomechanical motion. With this method we show precise measurements of a single motional quadrature with additive measurement noise of 4 times the zero point amplitude, and a reduction in sensitivity to injected measurement noise of a factor of 43 in comparison to a single tone, non-BAE measurement. We have also found a parametric instability which limits the coupling strength possible in our device, which will be described elsewhere. With straightforward improvements to the microwave resonator, we expect to be able to demonstrate sensitivity to one quadrature with additive measurement noise below the zero-point level, a necessary ingredient to produce and measure squeezed states of motion.

  7. An analysis of features of respiratory therapy departments that are avid for change.

    Science.gov (United States)

    Stoller, James K; Kester, Lucy; Roberts, Vincent T; Orens, Douglas K; Babic, Mark D; Lemin, Martha E; Hoisington, Edward R; Dolgan, Colleen M; Cohen, Harlow B; Chatburn, Robert L

    2008-07-01

    Models of organizational change-readiness have been developed, but little attention has been given to features of change-avid health-care institutions, and, to our knowledge, no attention has been given to features of change-avid respiratory therapy (RT) departments. We conducted an exploratory study to compare RT departments we deemed change-avid or non-change-avid, to identify differentiating characteristics. Our assessments regarding change-readiness and avidity were based on structured, in-person interviews of the technical directors and/or medical directors of 8 RT departments. Based on a priori criteria, 4 of the 8 RT departments were deemed change-avid, based on the presence of > or = 2 of the following 3 criteria: (1) uses a management information system, (2) uses a comprehensive RT protocol program, (3) uses noninvasive ventilation in > 20% of patients with exacerbation of chronic obstructive pulmonary disease. Our ratings of the departments were based on 2 scales: one from Integrated Organizational Development Inc, and the 8-stage change model of Kotter. The ratings of the 4 change-avid departments differed significantly from those of the 4 non-change-avid departments, on both the Integrated Organizational Development Inc scale and the Kotter scale. We identified 11 highly desired features of a change-avid RT department: a close working relationship between the medical director and the RT staff; a strong and supportive hospital "champion" for change; using data to define problems and measure the effectiveness of solutions; using redundant types of communication; recognizing resistance and minimizing obstacles to change; being willing to tackle tough issues; maintaining a culture of ongoing education; consistently rewarding change-avid behavior; fostering ownership for change and involving stakeholders; attending to RT leadership succession planning; and having and communicating a vision for the department. In this first exploratory study we found that

  8. Antibody function in neutralization and protection against HIV-1

    NARCIS (Netherlands)

    Hessell, A.J.

    2009-01-01

    The ability to induce neutralizing antibodies is generally thought to be of great importance for vaccine efficacy. In HIV-1 research this quality has been elusive as the HIV-1 virus has evolved multiple mechanisms to evade neutralizing antibodies. This thesis traces studies with four broadly

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

    NARCIS (Netherlands)

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

    1987-01-01

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

  10. DC8 and DC13 var genes associated with severe malaria bind avidly to diverse endothelial cells.

    Directory of Open Access Journals (Sweden)

    Marion Avril

    Full Text Available During blood stage infection, Plasmodium falciparum infected erythrocytes (IE bind to host blood vessels. This virulence determinant enables parasites to evade spleen-dependent killing mechanisms, but paradoxically in some cases may reduce parasite fitness by killing the host. Adhesion of infected erythrocytes is mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1, a family of polymorphic adhesion proteins encoded by var genes. Whereas cerebral binding and severe malaria are associated with parasites expressing DC8 and DC13 var genes, relatively little is known about the non-brain endothelial selection on severe malaria adhesive types. In this study, we selected P. falciparum-IEs on diverse endothelial cell types and demonstrate that DC8 and DC13 var genes were consistently among the major var transcripts selected on non-brain endothelial cells (lung, heart, bone marrow. To investigate the molecular basis for this avid endothelial binding activity, recombinant proteins were expressed from the predominant upregulated DC8 transcript, IT4var19. In-depth binding comparisons revealed that multiple extracellular domains from this protein bound brain and non-brain endothelial cells, and individual domains largely did not discriminate between different endothelial cell types. Additionally, we found that recombinant DC8 and DC13 CIDR1 domains exhibited a widespread endothelial binding activity and could compete for DC8-IE binding to brain endothelial cells, suggesting they may bind the same host receptor. Our findings provide new insights into the interaction of severe malaria adhesive types and host blood vessels and support the hypothesis that parasites causing severe malaria express PfEMP1 variants with a superior ability to adhere to diverse endothelial cell types, and may therefore endow these parasites with a growth and transmission advantage.

  11. IgG Avidity Test in Congenital Toxoplasmosis Diagnoses in Newborns

    Directory of Open Access Journals (Sweden)

    Zulmirene Cardoso Fonseca

    2017-06-01

    Full Text Available The goal of this study was to investigate the importance of IgG avidity testing in newborns (NBs diagnosed with early congenital toxoplasmosis. We collected samples from 88 puerperae infected by Toxoplasma gondii (T. gondii and their NBs (48 acutely-infected puerperae (AIP and 40 chronically-infected puerperae (CIP, from two public maternity hospitals in Goiania city, Goias, Brazil, from 2010 to 2015. Specific anti-T. gondii IgM and IgG serum levels and IgG avidity tests were evaluated using chemiluminescence. Congenital toxoplasmosis was observed in 66.66% (n = 32 of NBs with AIP, 94.1% presenting low avidity (LA and 51.61% presenting high avidity (HA test results. The IgG and IgM levels of NBs with LA and their puerperae were higher in comparison with HA NBs and puerperae (p = 0.0001. The avidity tests showed 100% specificity and 50% sensitivity (p = 0.0001. NBs with LA had a 15-fold increased risk of developing congenital toxoplasmosis in comparison with HA NBs. The IgG avidity test could be used to assist in early congenital toxoplasmosis diagnoses in NBs and LA, identifying a greater probability of vertical transmission.

  12. IgG Avidity Test in Congenital Toxoplasmosis Diagnoses in Newborns.

    Science.gov (United States)

    Fonseca, Zulmirene Cardoso; Rodrigues, Isolina Maria Xavier; Melo, Natália Cruz E; Avelar, Juliana Boaventura; Castro, Ana Maria; Avelino, Mariza Martins

    2017-06-18

    The goal of this study was to investigate the importance of IgG avidity testing in newborns (NBs) diagnosed with early congenital toxoplasmosis. We collected samples from 88 puerperae infected by Toxoplasma gondii (T. gondii) and their NBs (48 acutely-infected puerperae (AIP) and 40 chronically-infected puerperae (CIP)), from two public maternity hospitals in Goiania city, Goias, Brazil, from 2010 to 2015. Specific anti-T. gondii IgM and IgG serum levels and IgG avidity tests were evaluated using chemiluminescence. Congenital toxoplasmosis was observed in 66.66% (n = 32) of NBs with AIP, 94.1% presenting low avidity (LA) and 51.61% presenting high avidity (HA) test results. The IgG and IgM levels of NBs with LA and their puerperae were higher in comparison with HA NBs and puerperae (p = 0.0001). The avidity tests showed 100% specificity and 50% sensitivity (p = 0.0001). NBs with LA had a 15-fold increased risk of developing congenital toxoplasmosis in comparison with HA NBs. The IgG avidity test could be used to assist in early congenital toxoplasmosis diagnoses in NBs and LA, identifying a greater probability of vertical transmission.

  13. Sissejuhatus Tubinasse : Marianne Kõrveri "Äraoldud päevade summa" / Tõnu Karjatse

    Index Scriptorium Estoniae

    Karjatse, Tõnu

    2005-01-01

    Muusikaline dokumentaalfilm "Äraoldud päevade summa" helilooja Eduard Tubinast : stsenarist ja tekstide autor Jüri Reinvere : režissöör Marianne Kõrver : Exitfilm - Eesti Televisioon - SVT (Rootsi)

  14. Tartu Kevadpäevad 2008 : Nädalajagu muusikat igale maitsele / Signe Tamberg

    Index Scriptorium Estoniae

    Tamberg, Signe

    2008-01-01

    Tartu Kevadpäevad 2008 muusikaprogrammis: 34. tudengilaulu võistlusest 29. apr. Tartu Sadamateatris, öölaulupeost 28. apr. Kassitoome orus, kontsertidest "Rokime!" 2. mail ja "Folgime" 3. mail Raekoja platsil

  15. Linear Pursuit Differential Game under Phase Constraint on the State of Evader

    Directory of Open Access Journals (Sweden)

    Askar Rakhmanov

    2016-01-01

    Full Text Available We consider a linear pursuit differential game of one pursuer and one evader. Controls of the pursuer and evader are subjected to integral and geometric constraints, respectively. In addition, phase constraint is imposed on the state of evader, whereas pursuer moves throughout the space. We say that pursuit is completed, if inclusion y(t1-x(t1∈M is satisfied at some t1>0, where x(t and y(t are states of pursuer and evader, respectively, and M is terminal set. Conditions of completion of pursuit in the game from all initial points of players are obtained. Strategy of the pursuer is constructed so that the phase vector of the pursuer first is brought to a given set, and then pursuit is completed.

  16. Uudised : Voices of Europe tuleb Pärdi teosega. Puhkpillipäevad Võrus / Ingrid Peek

    Index Scriptorium Estoniae

    Peek, Ingrid

    2000-01-01

    1. sept. Tallinnas Kaarli kirikus toimuvast kontserdist, kus tuleb ettekandele Pärdi teos "Which was the son of...". 15. aug. avatakse Võrus V noorte puhkpillimängijate suvekool ja Võru vaskpillipäevad

  17. Eesti Suusapäevad Jay Peak´is / Peeter Teedla ; fotod: Peeter Teedla

    Index Scriptorium Estoniae

    Teedla, Peeter

    2006-01-01

    märtsikuu esimesel nädalalõpul idaranniku eestlaste suusapäevad, osavõtjaid 156, paljud perekondade ja väikeste lastega, organiseerijaks Kristin Raamot. Peeti murdmaasuusatamise - ja slaalomivõistlused

  18. Assessment of the anti-Naja haje antibodies elicited in a low dose multi-site immunization protocol.

    Science.gov (United States)

    El-Kady, E M; Ibrahim, N M; Wahby, A F

    2009-09-15

    The horse antibodies to Naja haje (Nh) elicited in a low dose multi-site immunization protocol were investigated from binding perspective in the context of antivenom maturation. We found that, this protocol evoked the production of lethality neutralizing avid antibodies in the first round of immunization which increases over the successive immunization rounds. The changes and the relative changes in the antibody parameters of each horse were taken as a measure for the efficacy of its immune system to respond by gaining and magnifying the antivenom parameters. While the avidity increases over the successive immunization rounds towards a maturation ceiling, the avidity gain and relative gain decreases. While the ED(50) gain increases over the immunization rounds, the relative ED(50) gain of the strong responder horse-1 is steadier than for the weak responders horse-2 and horse-3. The profiles for the gain and the relative gain of ELISA titers by three horses are pronouncedly different, reflecting great variations in the immune response by the individual animals. A late antigen dependent avidity pulse was detected after the last dose of the second immunization period, demonstrating that antibody maturation continues during the rest periods. The avidity pulse appears as an increase in avidity which returns to a base level within four weeks. These results indicted that maturation of antibodies to lethality neutralization relevant venom epitopes rather than maturation of antivenoms is the most important potency determining factor. Eventually, a main advantage of the low dose multi-site immunization protocol is the production of highly avid antibodies at the primary immunizations which is mostly crucial for the production of highly potent antivenoms.

  19. [Case of law-evading herbs poisoning that induced shock and myocardial damage].

    Science.gov (United States)

    Nakamura, Yoshihiko; Nakano, Minoru; Nakamura, Mitsunobu; Miyazaki, Dai; Okamori, Satoshi; Akuzawa, Hisashi; Yuasa, Masahiro

    2014-12-01

    Law-evading herbs may induce poisoning symptoms, especially when they contain synthetic cannabinoids. However, their detailed pharmacological effects have not yet been clarified. Some reports have previously described symptoms of poisoning, but only a few reports have so far described shock and myocardial damage (MD). We experienced a case of shock and MD in a patient who had smoked law-evading herbs. A 61-year-old male presented at an emergency department 8 hours after smoking law-evading herbs (Rush Trip, High Men Monster) with chest pain. A vasopressor agent was administered to treat shock and antiarrhythmic drugs were administered due to ventricular arrhythmia. The contents of the law-evading herbs were unknown, so an in-hospital follow-up was conducted to treat the patient's symptoms. The follow-up blood test showed an increased level of cardiac enzymes, which thereafter demonstrated a spontaneous remission. The systemic conditions tended to improve and the patient was discharged from the hospital on the 5th hospital day. The contents of the law-evading herbs in question were thereafter,analyzed, and synthetic cannabinoids (JWH-210, JWH-081 and JWH-122) as well as caffeine were detected. The cause for the poisoning symptoms were suspected to be the presence of synthetic cannabinoids and caffeine. Such law-evading herbs may contain synthetic cannabinoids and caffeine which both may induce shock and MD.

  20. Necrosis Avidity: A Newly Discovered Feature of Hypericin and its Preclinical Applications in Necrosis Imaging

    Science.gov (United States)

    Jiang, Binghu; Wang, Jichen; Ni, Yicheng; Chen, Feng

    2013-01-01

    Hypericin has been widely studied as a potent photosensitizer for photodynamic therapy in both preclinical and clinical settings. Recently, hypericin has also been discovered to have a specific avidity for necrotic tissue. This affinity is also observed in a series of radiolabeled derivatives of hypericin, including [123I]iodohypericin, [124I]iodohypericin, and [131I]iodohypericin. Hypericin, along with other necrosis-avid contrast agents, has been investigated for use in noninvasively targeting necrotic tissues in numerous disorders. Potential clinical applications of hypericin include the identification of acute myocardial infarction, evaluation of tissue viability, assessment of therapeutic responses to treatments, and interventional procedures for solid tumors. The mechanisms of necrosis avidity in hypericin remain to be fully elucidated, although several hypotheses have been suggested. In particular, it has been proposed that the necrosis avidity of hypericin is compound specific; for instance, cholesterol, phosphatidylserine, or phosphatidylethanolamine components in the phospholipid bilayer of cellular membranes may be the major targets for its observed selectivity. Further investigations are needed to identify the specific binding moiety that is responsible for the necrosis avidity of hypericin. PMID:24052807

  1. The avidity of cross-reactive virus-specific T cells for their viral and allogeneic epitopes is variable and depends on epitope expression.

    Science.gov (United States)

    van den Heuvel, Heleen; Heutinck, Kirstin M; van der Meer-Prins, Ellen M W; Franke-van Dijk, Marry E I; van Miert, Paula P M C; Zhang, Xiaoqian; Ten Berge, Ineke J M; Claas, Frans H J

    2018-01-01

    Virus-specific T cells can recognize allogeneic HLA (allo-HLA) through cross-reactivity of their T-cell receptor (TCR). In a transplantation setting, such allo-HLA cross-reactivity may contribute to harmful immune responses towards the allograft, provided that the cross-reactive T cells get sufficiently activated upon recognition of the allo-HLA. An important determinant of T-cell activation is TCR avidity, which to date, has remained largely unexplored for allo-HLA-cross-reactive virus-specific T cells. For this purpose, cold target inhibition assays were performed using allo-HLA-cross-reactive virus-specific memory CD8+ T-cell clones as responders, and syngeneic cells loaded with viral peptide and allogeneic cells as hot (radioactively-labeled) and cold (non-radioactively-labeled) targets. CD8 dependency of the T-cell responses was assessed using interferon γ (IFNγ) enzyme-linked immunosorbent assay (ELISA) in the presence and absence of CD8-blocking antibodies. At high viral-peptide loading concentrations, T-cell clones consistently demonstrated lower avidity for allogeneic versus viral epitopes, but at suboptimal concentrations the opposite was observed. In line, anti-viral reactivity was CD8 independent at high, but not at suboptimal viral-peptide-loading concentrations. The avidity of allo-HLA-cross-reactive virus-specific memory CD8+ T cells is therefore highly dependent on epitope expression, and as a consequence, can be both higher and lower for allogeneic versus viral targets under different (patho)physiological conditions. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  2. Design and development of receptor-avid peptide conjugates for in-vivo targeting of cancer

    Science.gov (United States)

    Volkert, Wynn A.; Hoffman, Timothy J.

    1999-07-01

    Radiometallated peptides that exhibit high specificity for cognate receptors over expressed on cancer cells offer important potential as site-directed diagnostic and therapeutic radiopharmaceutical. The formation of effective radioactive drugs for specific in vivo targeting of cancerous tumors is being facilitated by the integration of novel chelation strategies and receptor-avid derivatives. Significant efforts are being made to design Technetium-99m labeled for diagnostic imaging of cancerous tumors for use in conjunction with Single Photon Emission Tomography instrumentation in nuclear medicine. Receptor avid radiopharmaceutical are also being developed that utilize other radionuclides for imaging and therapeutic applications. Despite the technological challenges that must be overcome, radiolabeled receptor avid peptide conjugates are providing promising site-directed targeting agents for the assessment and treatment of cancerous tumors in humans.

  3. Age affects quantity but not quality of antibody responses after vaccination with an inactivated flavivirus vaccine against tick-borne encephalitis.

    Directory of Open Access Journals (Sweden)

    Karin Stiasny

    Full Text Available The impairment of immune functions in the elderly (immunosenescence results in post-vaccination antibody titers that are significantly lower than in young individuals. It is, however, a controversial question whether also the quality of antibodies declines with age. In this study, we have therefore investigated the age-dependence of functional characteristics of antibody responses induced by vaccination with an inactivated flavivirus vaccine against tick-borne encephalitis (TBE. For this purpose, we quantified TBE virus-specific IgG and neutralizing antibody titers in post-vaccination sera from groups of young and elderly healthy adults and determined antibody avidities and NT/ELISA titer ratios (functional activity. In contrast to the quantitative impairment of antibody production in the elderly, we found no age-related differences in the avidity and functional activity of antibodies induced by vaccination, which also appeared to be independent of the age at primary immunization. There was no correlation between antibody avidity and NT/ELISA ratios suggesting that additional factors affect the quality of polyclonal responses, independent of age. Our work indicates that healthy elderly people are able to produce antibodies in response to vaccination with similar avidity and functional activity as young individuals, albeit at lower titers.

  4. The evaluation of rubella and sitomegalovirus IgG avidity tests in pregnants: four-year experience

    Directory of Open Access Journals (Sweden)

    Berrin Uzun

    2014-09-01

    Full Text Available Objective: In this study, we aim to evaluate the retrospective IgG avidity index (AI test results of the pregnant, who have applied to our hospital and had pregnancy screening test and have been asked for rubella and cytomegalovirus antibody tests and IgG AI test in 4 year period. Methods: Anti-rubella IgM, anti-rubella IgG, anti-CMV IgM and anti-CMV antibodies were performed by IMMULITE 2000XPi™ Immunoassay System (Siemens, Germany whereas IgG AI tests were performed by commercial kits of rubella and cytomegalovirus antibody tests (Dia.Pro® Diagnostic, Milano-Italy. Results: Between January 2010 and December 2013, 23 (7.32 % of 314 pregnant women tested rubella IgG AI had low AI, and 266 cases had high AI rate; 14 (17.28% of 81 pregnant women tested CMV IgG AI, had lower AI rate, 52 of them had high AI. 9 out of 23 pregnant women, who were detected low rubella were requested only AI without any IgM and IgG value; the IgG antibody of 13 pregnant was reactive, and IgM antibody was not requested; IgG and IgM antibody of 1 pregnant was detected positive. When 5 pregnant, who were detected low CMV AI were requested AI without IgG and IgM value; the IgG and IgM of 4 was reactive; 4 of them had IgG reactive but IgM negative; 1 had IgG and IgM negative. Conclusion: As a result, our low rubella AI rate has been detected lower than the rates in our country since our study population contains only the pregnant. Our low CMV AI rate varies due to the same reasons as literature data. During pregnancy scanning, performing of AI testing together with specific IgG and IgM will save both time and will be more meaningful in clinical evaluation for pregnant women. J Clin Exp Invest 2014; 5 (3: 420-423

  5. Association between {sup 18}F-FDG avidity and the BRAF mutation in papillary thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Suk Hyun; Han, Sang Won; Lee, Hyo Sang; Chae, Sun Young; Lee, Jong Jin; Song, Dong Eun; Ryu, Jin Sook [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2016-03-15

    The BRAF mutation, a potential prognostic factor in papillary thyroid carcinoma (PTC), is associated with a high expression of the glucose transporter gene. We investigated which clinicopathologic factors, including BRAF mutation status, influence {sup 18}F-fluoro-2-deoxyglucose ({sup 18}F-FDG) avidity. We retrospectively reviewed 55 patients who underwent BRAF analysis from biopsy-confirmed PTC and {sup 18}F-FDG positron emission tomography/computed tomography within 6 months before undergoing thyroid surgery from September 2008 to August 2014. Tumors were considered to be {sup 18}F-FDG avid if the uptake was greater than that of the liver. {sup 18}F-FDG uptake of PTCs was also analyzed semiquantitatively using SUV{sub max}. The association between {sup 18}F-FDG avidity and clinicopathologic variables (age, tumor size, perithyroidal extension, cervical lymph node status, and BRAF mutation status) was investigated. Twenty-nine (52.7 %) of 55 patients had {sup 18}F-FDG-avid PTCs. PTCs with the BRAF mutation showed higher {sup 18}F-FDG avidity (24/38, 63.2 %) than those without (5/17, 29.4 %). The BRAF mutation (p = 0.025) and tumor size (p = 0.003) were significantly associated with {sup 18}F-FDG avidity in univariate analysis, and the BRAF mutation status remained significant after adjusting for tumor size in multivariate analysis (p = 0.015). In the subgroup of tumor size ≥ 1 cm, the BRAF mutation was the only factor significantly associated with {sup 18}F-FDG avidity (p = 0.021). The mean SUV{sub max} of PTCs with the BRAF mutation was significantly higher than that of those without (4.89 ± 6.12 vs. 1.96 ± 1.10, p = 0.039). The BRAF mutation must be one of the most important factors influencing {sup 18}F-FDG avidity in PTCs, especially in those with a tumor size ≥ 1 cm.

  6. IgG Avidity Test in Congenital Toxoplasmosis Diagnoses in Newborns

    OpenAIRE

    Zulmirene Cardoso Fonseca; Isolina Maria Xavier Rodrigues; Natália Cruz e Melo; Juliana Boaventura Avelar; Ana Maria de Castro; Mariza Martins Avelino

    2017-01-01

    The goal of this study was to investigate the importance of IgG avidity testing in newborns (NBs) diagnosed with early congenital toxoplasmosis. We collected samples from 88 puerperae infected by Toxoplasma gondii (T. gondii) and their NBs (48 acutely-infected puerperae (AIP) and 40 chronically-infected puerperae (CIP)), from two public maternity hospitals in Goiania city, Goias, Brazil, from 2010 to 2015. Specific anti-T. gondii IgM and IgG serum levels and IgG avidity tests were evaluated u...

  7. An Investigation Into Australian Personal Tax Evaders - Their Attitudes Towards Compliance And The Penalties For Non-Compliance

    National Research Council Canada - National Science Library

    Ken Devos

    2009-01-01

    .... This study investigates the relationship that exists between selected tax compliance variables and the attitudes and behaviour of Australian personal 'tax evaders' towards compliance and the penalties...

  8. Experimental Toxoplasma gondii infections in pigs: Humoral immune response, estimation of specific IgG avidity and the challenges of reproducing vertical transmission in sows.

    Science.gov (United States)

    Basso, Walter; Grimm, Felix; Ruetten, Maja; Djokic, Vitomir; Blaga, Radu; Sidler, Xaver; Deplazes, Peter

    2017-03-15

    Ten pregnant sows were experimentally inoculated per os with T. gondii in order to investigate vertical and galactogenic transmission of the parasite and the evolution and maturation of the specific IgG humoral response in the sows and piglets. Five seronegative sows received 10(4)T. gondii (CZ isolate clone H3) sporulated oocysts during late-pregnancy (Exp. 1), three sows received 10(4) oocysts during mid-pregnancy (Exp. 2) and three sows from Exp. 1 (and two seronegative sows) were re-inoculated with 10(5) oocysts during a further pregnancy (late-pregnancy) (Exp. 3). Besides, six 4.5 week-old piglets inoculated per os with 5×10(3) oocysts were also included in the serological investigations. All animals seroconverted (PrioCHECK Toxoplasma Ab porcine ELISA, Prionics, Switzerland) by 2-3 weeks post inoculation (wpi) and remained seropositive for at least 38 weeks or until euthanasia. Four chronically infected sows from Exp. 1 and 2 were serologically monitored during a further pregnancy and no reactivation, but a decrease of the antibody levels was observed at farrowing (Exp. 4). In all experiments, the specific IgG-avidity was initially low, increased during the course of infection and after re-inoculations. An avidity index (AI) ≥40% could be used to rule out recent infections (toxoplasmosis in pigs are still unknown. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The hypervariable region of Streptococcus pyogenes M protein escapes antibody attack by antigenic variation and weak immunogenicity

    DEFF Research Database (Denmark)

    Lannergård, Jonas; Gustafsson, Caj Ulrik Mattias; Waldemarsson, Johan

    2011-01-01

    Sequence variation of antigenic proteins allows pathogens to evade antibody attack. The variable protein commonly includes a hypervariable region (HVR), which represents a key target for antibodies and is therefore predicted to be immunodominant. To understand the mechanism(s) of antibody evasion...

  10. Determination of IgG avidity in BALB/c mice experimentally infected with Toxocara canis.

    Science.gov (United States)

    Schoenardie, Elizandra Roselaine; Scaini, Carlos James; Avila, Luciana Farias da Costa de; Sperotto, Rita Leal; Borsuk, Sibele; Felicetti, Cristine Dias Pires; Pepe, Michele; Berne, Maria Elisabeth Aires

    2014-01-01

    Toxocariasis is a zoonotic disease in that IgM titers can remain high for long periods making difficult to determine the stage of the disease. The aim of this study is to investigate the applicability of indirect ELISA, associated with urea, to discriminate between the acute and chronic toxocariasis. IgG avidity was evaluated in 25 BALB/c mice experimentally infected with 1000 Toxocara canis eggs. Blood samples were collected, and sera treated with 6 M urea and assayed by ELISA every two weeks. The percent IgG avidity was determined using the mean absorbance of sera treated with urea, divided by the mean absorbance of untreated sera. In the first 15 days post-inoculation, was observed a low percentage, between 7.25 and 27.5%, IgG avidity, characteristic of an acute infection. After 60 days of infection, all the mice showed between 31.4 and 58% IgG avidity, indicating a chronic infection.

  11. Searching for avidity by chemical ligation of combinatorially self-assembled DNA-encoded ligand libraries.

    Science.gov (United States)

    Matysiak, Stefan; Hellmuth, Klaus; El-Sagheer, Afaf H; Shivalingam, Arun; Ariyurek, Yavuz; de Jong, Marco; Hollestelle, Martine J; Out, Ruud; Brown, Tom

    2017-12-19

    DNA encoded ligands are self-assembled into bivalent complexes and chemically ligated to link their identities. To demonstrate their potential as a combinatorial screening platform for avidity interactions, the optimal bivalent aptamer design (examplar ligands) for human alpha-thrombin is determined in a single round of selection and the DNA scaffold replaced with minimal impact on the final design.

  12. Ta(l)king sides: ethical and methodological challenges in comparative fieldwork on avid football rivalries

    NARCIS (Netherlands)

    Spaaij, R.; Geilenkirchen, M.

    2011-01-01

    Previous research on football (soccer) fan cultures has documented the lived experiences of devoted football supporters. Few studies, however, have used participant observation and intensive interviewing to examine the deep-rooted inter-group oppositions that characterize avid football rivalries.

  13. Benign Bone Conditions That May Be FDG-avid and Mimic Malignancy

    NARCIS (Netherlands)

    Kwee, Thomas C.; de Klerk, John M. H.; Nix, Maarten; Heggelman, Ben G. F.; Dubois, Stefan V.; Adams, Hugo J. A.

    Positron emission tomography with the radiotracer F-18-fluoro-2-deoxy-D-glucose (FDG) plays an important role in the evaluation of bone pathology. However, FDG is not a cancer-specific agent, and knowledge of the differential diagnosis of benign FDG-avid bone alterations that may resemble malignancy

  14. A new human IgG avidity test, using mixtures of recombinant antigens (rROP1, rSAG2, rGRA6), for the diagnosis of difficult-to-identify phases of toxoplasmosis.

    Science.gov (United States)

    Drapała, Dorota; Holec-Gąsior, Lucyna; Kur, Józef; Ferra, Bartłomiej; Hiszczyńska-Sawicka, Elżbieta; Lautenbach, Dariusz

    2014-07-01

    The preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis was suspected was higher, at 100% and 95.4%, respectively, than for people with chronic infection, at 88.2% and 70.6%. In this study a different trend in avidity maturation of IgG antibodies for two mixtures of proteins in comparison with native antigen was observed. The results suggest that a new IgG avidity test using the mixtures of recombinant antigens may be useful for the diagnosis of difficult-to-identify phases of toxoplasmosis. For this reason, selected mixtures after the additional tests on groups of sera with well-defined dates of infection could be used as a better alternative to the native antigens of the parasite in the serodiagnosis of human T. gondii infection. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Eesti Muusika Päevad 2000 : ECPNMi juhatus Tallinnas / Consuelo Diez ; interv. Evelin Kõrvits

    Index Scriptorium Estoniae

    Diez, Consuelo

    2000-01-01

    28.-30. apr. pidas Tallinnas aastakoosolekut ning külastas Eesti Muusika Päevade kontserte ECPNMi (European Conference of Promoters of New Music) juhatus. ECPNMi juhatuse liikmed räägivad uue muusika üritustest oma riikides, muljeid eesti muusika päevadelt

  16. Märtsipäevade valupisaraid peab lastele näitama / Anu Bollverk

    Index Scriptorium Estoniae

    Bollverk, Anu

    2009-01-01

    1949. aasta märtsiküüditamisele pühendatud mälestuspäevast Koeru kultuurimajas ning sealse huviteatri poolt ette kantud Herbert Lasti näidendist "Valupisarais märtsipäevad" (lavastajad Herbert Last ja Uno Aav)

  17. Eesti muusika päevad - üks kord aastas, kõigile / Jelena Gandshu

    Index Scriptorium Estoniae

    Gandshu, Jelena

    2008-01-01

    Muusikateadlased Jelena Gandshu ja Gerhard Lock, heliloojad Age Hirv ja Liis Jürgens 3.-10. aprillini toimunud Eesti muusika päevade kontsertidest: kinos Sõprus "Sensatsioon!!!", Kultuuritehases Polymer "Cellissimo", Estonia kontserdisaalis ERSO "Sümfoonilised hääled", Tallinna raekojas Mihkel Poll ja Oliver Kuusik, Katariina kirikus PaukenfEst, Nigulistes Jüri Reinvere autorikontsert. Järgneb

  18. Matemaatikaõpetajate pidupäevad Tartus / Viia Keeru, Tiit Lepmann

    Index Scriptorium Estoniae

    Keeru, Viia

    2009-01-01

    36. matemaatikaõpetajate päevadest, mis pühendati professor Olaf Prinitsa 85. sünniaastapäevale. Päevade lõpus selgusid tänavused professor G. Rägo nimelise medali laureaadid, kelle seas olid ka TLÜ Haapsalu Kolledži lektor Sirje Piht ja TLÜ matemaatika didaktika dotsent Madis Lepik

  19. Nüüdismuusika päevad pakuvad põnevat kuulamist

    Index Scriptorium Estoniae

    2005-01-01

    Pärnu nüüdismuusika päevade "Muusika ja arhitektuur" raames 20. jaan. esinevad loengutega Endla teatri sammassaalis arhitektid Veronika Valk ja Leonhard Lapin ning muusikateadlased Gerhard Lock ja Jaan Ross. Toivo Tulevi autorikontserdist Agape keskuses

  20. Diagnosis of Toxoplasmosis in Pregnant Women by IgG Avidity Assay

    Directory of Open Access Journals (Sweden)

    M. Roozbehani

    2015-02-01

    Full Text Available Background: Toxoplasma gondii is an obligate intracellular parasite that has ability to infect most warm blooded vertebrates. primary infection during pregnancy can lead to transmission of the infection to the fetus, with associated symptoms. the aim of this study was to compare methods for serological measurement of anti-toxoplasma IgG and IgM in pregnant women and also tested seroconversion mothers by IgG avidity, and finally comparing the results of these experiments with each others. Methods: In this comparative analytical study, from 2120 pregnant women referred to karaj medical laboratories (in 1392 years serum specimens were obtained and tested with Chemiluminescence (CLIA & (Enzyme Linked Fluorescent Assay ELFA methods. Then for detection of chronic and acute infection, serum IgM+ specimens tested by IgG Avidity assay. Results: In this study, out of 1362 cases of 2120 pregnant women were IgG+ with ELFA & CLIA methods. In IgM ELFA method, 38 samples were positive and 2 samples were borderline. In IgM CLIA method, 37 samples were positive and1samples were borderline. In IgG Avidity, from 40 serum samples, 15 samples were low aviditiy, 20 samples were high avidity and 5 samples were borderlines. In IgG Avidity positive predictive value were 57%. Conclusion: Every pregnant women needs to do anti-toxoplasma IgG and IgM tests. after considering all valid serological and molecular methods for deciding to treatment or termination of gestation must be used the other sensitive and reliable parasitology methods such as inoculation of susceptible lab animal and PCR on amniotic fluid.

  1. Prenatal toxoplasmosis antibody and childhood autism.

    Science.gov (United States)

    Spann, Marisa N; Sourander, Andre; Surcel, Heljä-Marja; Hinkka-Yli-Salomäki, Susanna; Brown, Alan S

    2017-05-01

    There is evidence that some maternal infections during the prenatal period are associated with neurodevelopmental disorders, such as childhood autism. However, the association between autism and Toxoplasma gondii (T. gondii), an intracellular parasite, remains unclear. The authors examined whether serologically confirmed maternal antibodies to T. gondii are associated with odds of childhood autism in offspring. The study is based on a nested case-control design of a large national birth cohort (N = 1.2 million) and the national psychiatric registries in Finland. There were 874 cases of childhood autism and controls matched 1:1 on date of birth, sex, birthplace and residence in Finland. Maternal sera were prospectively assayed from a national biobank for T. gondii IgM and IgG antibodies; IgG avidity analyses were also performed. High maternal T. gondii IgM antibody was associated with a significantly decreased odds of childhood autism. Low maternal T. gondii IgG antibody was associated with increased offspring odds of autism. In women with high T. gondii IgM antibodies, the IgG avidity was high for both cases and controls, with the exception of three controls. The findings suggest that the relationship between maternal T. gondii antibodies and odds of childhood autism may be related to the immune response to this pathogen or the overall activation of the immune system. Autism Res 2017, 10: 769-777. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  2. Radiometallated receptor-avid peptide conjugates for specific in vivo targeting of cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, T.J.; Quinn, T.P.; Volkert, W.A. E-mail: VolkertW@health.missouri.edu

    2001-07-01

    New receptor-avid radiotracers are being developed for site-specific in vivo targeting of a myriad of receptors expressed on cancer cells. This review exemplifies strategies being used to design radiometallated peptide conjugates that maximize uptake in tumors and optimize their in vivo pharmacokinetic properties. Efforts to produce synthetic peptide analogues that target the following three receptor systems are highlighted: Gastrin releasing peptide (GRP), alpha-melanocyte stimulating hormone ({alpha}-MSH), and guanylate cyclase-C (GC-C) receptors.

  3. evad : [luuletused] / Philip Larkin ; inglise keelest tlk. Maarja Kangro

    Index Scriptorium Estoniae

    Larkin, Philip

    2007-01-01

    Sisu: Päevad ; Mitte midagi öelda ; See olgu värss ; Uurimus lugemisharjumustest ; Hommage valitsusele ; Vesi ; Vajakud ; Viige üks koju lastele ; Jutt voodis ; Kõrged aknad ; Sa jätkad elu ; Kui. Orig.: Days ; Nothing to be said ; This be the verse ; A study of reading habits ; Homage to a government ; Water ; Wants ; Take one home for the kiddies ; Talking in bed ; High windows ; Continuing to live ; If

  4. DO PENALTIES AND ENFORCEMENT MEASURES MAKE TAXPAYERS MORE COMPLIANT? THE VIEW OF AUSTRALIAN TAX EVADERS

    OpenAIRE

    Dr Ken Devos

    2013-01-01

    The tax compliance literature indicates that many factors, including, economic, social, psychological and demographic, impact upon the compliance behaviour of individual taxpayers. This study explores the relationship, if any, that exists between selected tax compliance and demographic variables and the compliance behaviour of Australian individual tax evaders. The study employed a mixed method research approach comprising both a survey and interviews. The findings revealed that tax law enfor...

  5. Muusika : Jeremija nutulaulud palmipuudepühal. Jätkub "Musica Grande". Lihavõttetervitus Barcelonast. Rannap "Selges eesti helikeeles". Juba XIII trompetipäevad. III klavessiinipäevad / Jaan-Eik Tulve

    Index Scriptorium Estoniae

    Tulve, Jaan-Eik, 1967-

    2002-01-01

    Vox Clamantise kontsertidest Tartus ja Tallinnas. Jätkub sari "Musica Grande" kontsertidega Tartus ja Tallinnas pealkirjaga "Kontsertlik". Eestisse sõidab esinema üks Hispaania tippkoore Coral Cantiga Barcelonast. Rein Rannapi tänavusest suurprojektist, klaveriõhtust "Selges eesti helikeeles". 1. - 7. aprillini toimuvad EMA rahvusvahelised trompetipäevad. 4. - 7. aprillini korraldab Eesti Klavessiinisõprade Tsunft III klavessiinipäevad

  6. Antimitochondrial antibody

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003529.htm Antimitochondrial antibody To use the sharing features on this page, please enable JavaScript. Antimitochondrial antibodies (AMA) are substances ( antibodies ) that form against mitochondria. ...

  7. Novel HIV IL-4R antagonist vaccine strategy can induce both high avidity CD8 T and B cell immunity with greater protective efficacy.

    Science.gov (United States)

    Jackson, Ronald J; Worley, Matthew; Trivedi, Shubhanshi; Ranasinghe, Charani

    2014-09-29

    We have established that the efficacy of a heterologous poxvirus vectored HIV vaccine, fowlpox virus (FPV)-HIV gag/pol prime followed by attenuated vaccinia virus (VV)-HIV gag/pol booster immunisation, is strongly influenced by the cytokine milieu at the priming vaccination site, with endogenous IL-13 detrimental to the quality of the HIV specific CD8+ T cell response induced. We have now developed a novel HIV vaccine that co-expresses a C-terminal deletion mutant of the mouse IL-4, deleted for the essential tyrosine (Y119) required for signalling. In our vaccine system, the mutant IL-4C118 can bind to IL-4 type I and II receptors with high affinity, and transiently prevent the signalling of both IL-4 and IL-13 at the vaccination site. When this IL-4C118 adjuvanted vaccine was used in an intranasal rFPV/intramuscular rVV prime-boost immunisation strategy, greatly enhanced mucosal/systemic HIV specific CD8+ T cells with higher functional avidity, expressing IFN-γ, TNF-α and IL-2 and greater protective efficacy were detected. Surprisingly, the IL-4C118 adjuvanted vaccines also induced robust long-lived HIV gag-specific serum antibody responses, specifically IgG1 and IgG2a. The p55-gag IgG2a responses induced were of a higher magnitude relative to the IL-13Rα2 adjuvant vaccine. More interestingly, our recently tested IL-13Rα2 adjuvanted vaccine which only inhibited IL-13 activity, even though induced excellent high avidity HIV-specific CD8+ T cells, had a detrimental impact on the induction of gag-specific IgG2a antibody immunity. Our observations suggest that (i) IL-4 cell-signalling in the absence of IL-13 retarded gag-specific antibody isotype class switching, or (ii) IL-13Rα2 signalling was involved in inducing good gag-specific B cell immunity. Thus, we believe our novel IL-4R antagonist adjuvant strategy offers great promise not only for HIV-1 vaccines, but also against a range of chronic infections where sustained high quality mucosal and systemic T and B

  8. A high seroprevalence of antibodies to pertussis toxin among Japanese adults: Qualitative and quantitative analyses.

    Directory of Open Access Journals (Sweden)

    Takumi Moriuchi

    Full Text Available In 2013, national serosurveillance detected a high seroprevalence of antibodies to pertussis toxin (PT from Bordetella pertussis among Japanese adults. Thus, we aimed to determine the cause(s of this high seroprevalence, and analyzed the titers of antibodies to PT and filamentous hemagglutinin (FHA among adults (35-44 years old, young children (4-7 years old, and older children (10-14 years old. Our quantitative analyses revealed that adults had higher seroprevalences of anti-PT IgG and PT-neutralizing antibodies, and similar titers of anti-FHA IgG, compared to the young and older children. Positive correlations were observed between the titers of PT-neutralizing antibodies and anti-PT IgG in all age groups (rs values of 0.326-0.522, although the correlation tended to decrease with age. The ratio of PT-neutralizing antibodies to anti-PT IgG was significantly different when we compared the serum and purified IgG fractions among adults (p = 0.016, although this result was not observed among young and older children. Thus, it appears that some adults had non-IgG immunoglobulins to PT. Our analyses also revealed that adults had high-avidity anti-PT IgG (avidity index: 63.5%, similar results were observed among the children; however, the adults had lower-avidity anti-FHA IgG (37.9%, p < 0.05. It is possible that low-avidity anti-FHA IgG is related to infection with other respiratory pathogens (e.g., Bordetella parapertussis, Haemophilus influenzae, or Mycoplasma pneumoniae, which produces antibodies to FHA-like proteins. Our observations suggest that these adults had been infected with B. pertussis and other pathogen(s during their adulthood.

  9. Clinical significance of pretreatment FDG PET/CT IN MOBG-avid pediatric neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seo Young; Kim, Yong Il; Cheon, Gi Jeong; Kang, Keon Wook; Chung, June Key; Lee, Dong Soo; Kang, Hyoung Jin; Shin, Hee Young [Seoul National University Hospital, Seoul (Korea, Republic of); Kim, E. Edmund [Seoul National University, Seoul (Korea, Republic of); Rahim, Muhammad Kashif [Nishtar Medical College and Hospital, Multan (Pakistan)

    2017-06-15

    {sup 18}F-fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging is well known to have clinical significance in the initial staging and response evaluation of the many kinds of neoplasms. However, its role in the pediatric neuroblastoma is not clearly defined. In the present study, the clinical significance of FDG-PET/computed tomography (CT) in 123I- or 131I-metaiodobenzylguanidine (MIBG)-avid pediatric neuroblastoma was investigated. Twenty patients with neuroblastoma who undertook pretreatment FDG PET/CT at our institute between 2008 and 2015 and showed MIBG avidity were retrospectively enrolled in the present study. Clinical information—including histopathology, and serum markers—and several PET parameters—including SUVmax of the primary lesion (Psuv), target-to-background ratio (TBR), metabolic tumor volume (MTV), and coefficient of variation (CV)—were analyzed. The prognostic effect of PET parameters was evaluated in terms of progression-free survival (PFS). Total 20 patients (4.5 ± 3.5 years) were divided as two groups by disease progression. Six patients (30.0 %) experienced disease progression and one patient (5.0 %) died during follow-up period. There were not statistically significant in age, stage, MYCN status, primary tumor size, serum lactate dehydrogenase (LDH), neuron-specific enolase (NSE), and ferritin level between two groups with progression or no progression. However, Psuv (p = 0.017), TBR (p = 0.09), MTV (p = 0.02), and CV (p = 0.036) showed significant differences between two groups. In univariate analysis, PFS was significantly associated with Psuv (p = 0.021) and TBR (p = 0.023). FDG-PET parameters were significantly related with progression of neuroblastoma. FDG-PET/CT may have the potential as a valuable modality for evaluating prognosis in the patients with MIBG-avid pediatric neuroblastoma.

  10. Excretion and toxicity evaluation of (131)I-Sennoside A as a necrosis-avid agent.

    Science.gov (United States)

    Yin, Zhiqi; Sun, Lidan; Jin, Qiaomei; Song, Shaoli; Feng, Yuanbo; Liao, Hong; Ni, Yicheng; Zhang, Jian; Liu, Wei

    2017-11-01

    1. Sennoside A (SA) is a newly identified necrosis-avid agent that shows capability for imaging diagnosis and tumor necrosis targeted radiotherapy. As a water-soluble compound, (131)I-Sennoside A ((131)I-SA) might be excreted predominately through the kidneys with the possibility of nephrotoxicity. 2. To further verify excretion pathway and examine nephrotoxicity of (131)I-SA, excretion and nephrotoxicity were appraised. The pharmacokinetics, hepatotoxicity and hematotoxicity of (131)I-SA were also evaluated to accelerate its possible clinical translation. All these studies were conducted in mice with ethanol-induced muscular necrosis following a single intravenous administration of 131I-SA at 18.5 MBq/kg or 370 MBq/kg. 3. Excretion data revealed that (131)I-SA was predominately (73.5% of the injected dose (% ID)) excreted via the kidneys with 69.5% ID detected in urine within 72 h post injection. Biodistribution study indicated that (131)I-SA exhibited initial high distribution in the kidneys but subsequently a fast renal clearance, which was further confirmed by the results of autoradiography and single-photon emission computed tomography-computed tomography (SPECT-CT) imaging. The maximum necrotic to normal muscle ratio reached to 7.9-fold at 48 h post injection, which further verified the necrosis avidity of (131)I-SA. Pharmacokinetic parameters showed that (131)I-SA had fast blood clearance with an elimination half-life of 6.7 h. Various functional indexes were no significant difference (p > 0.05) between before administration and 1 d, 8 d, 16 d after administration. Histopathology showed no signs of tissue damage. 4. These data suggest (131)I-SA is a safe and promising necrosis-avid agent applicable in imaging diagnosis and tumor necrosis targeted radiotherapy.

  11. Partial blood meal, carbohydrate availability, and bloodfeeding-postponement effects on human host avidity and deet repellency in Aedes albopictus.

    Science.gov (United States)

    Xue, Rui-De; Barnard, Donald R

    2009-12-01

    Host avidity and deet repellency were measured in partially bloodfed Aedes albopictus provided 10% sucrose, water, or nothing when access to a human host was postponed for 1 to 72 h after a partial blood meal. Carbohydrate availability and postfeeding time influenced host avidity, but partial blood meal effects were not significant. Mean host avidity declined significantly between hours 1 and 6 (range 50-18%) but increased significantly between hours 24 (54%) and 72 (68%) after a partial blood meal. Females provided sucrose solution and females denied sucrose or water showed the least (29%) and most (39%) host avidity, regardless of other treatment effects. The longest and shortest deet protection times were 8.5 h against females provided sucrose and 7.3 h against females denied sucrose or water, respectively. Denial of carbohydrate sustenance significantly increased host avidity and deet repellency in partially bloodfed female Ae. albopictus, whereas sucrose availability led to reduced host responding activity and decreased repellency of deet.

  12. Structural requirements of the major protective antibody to Haemophilus influenzae type b

    DEFF Research Database (Denmark)

    Hougs, L; Juul, L; Svejgaard, A

    1999-01-01

    Protective antibodies to the important childhood pathogen Haemophilus influenzae type b (Hib) are directed against the capsular polysaccharide (HibCP). Most of the antibody is encoded by a well-defined set of ("canonical") immunoglobulin genes, including the Vkappa A2 gene, and expresses an idiot......Protective antibodies to the important childhood pathogen Haemophilus influenzae type b (Hib) are directed against the capsular polysaccharide (HibCP). Most of the antibody is encoded by a well-defined set of ("canonical") immunoglobulin genes, including the Vkappa A2 gene, and expresses...... an idiotypic marker (HibId-1). In comparison to noncanonical antibodies, the canonical antibody is generally of higher avidity, shows higher levels of in vitro bactericidal activity, and is more protective in infant rats. Using site-directed mutagenesis, we here characterize canonical HibCP antibodies...

  13. Naturally enveloped AAV vectors for shielding neutralizing antibodies and robust gene delivery in vivo.

    Science.gov (United States)

    György, Bence; Fitzpatrick, Zachary; Crommentuijn, Matheus H W; Mu, Dakai; Maguire, Casey A

    2014-08-01

    Recently adeno-associated virus (AAV) became the first clinically approved gene therapy product in the western world. To develop AAV for future clinical application in a widespread patient base, particularly in therapies which require intravenous (i.v.) administration of vector, the virus must be able to evade pre-existing antibodies to the wild type virus. Here we demonstrate that in mice, AAV vectors associated with extracellular vesicles (EVs) can evade human anti-AAV neutralizing antibodies. We observed different antibody evasion and gene transfer abilities with populations of EVs isolated by different centrifugal forces. EV-associated AAV vector (ev-AAV) was up to 136-fold more resistant over a range of neutralizing antibody concentrations relative to standard AAV vector in vitro. Importantly in mice, at a concentration of passively transferred human antibodies which decreased i.v. administered standard AAV transduction of brain by 80%, transduction of ev-AAV transduction was not reduced and was 4000-fold higher. Finally, we show that expressing a brain targeting peptide on the EV surface allowed significant enhancement of transduction compared to untargeted ev-AAV. Using ev-AAV represents an effective, clinically relevant approach to evade human neutralizing anti-AAV antibodies after systemic administration of vector. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Clinical criteria for predicting benefit of ICD/PM in post myocardial infarction patients: an AVID and CAST analysis.

    Science.gov (United States)

    Hallstrom, Alfred P; Wyse, D George; McAnulty, John

    2008-12-01

    Three clinical factors from the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial-heart failure, left ventricular dysfunction and certain historical features defined a subgroup in which an implantable cardioverter defibrillator (ICD/PM) has a mortality advantage over amiodarone. These three factors were jointly evaluated in the AVID cohort with ischemic heart disease (IHD) and the results applied in placebo-treated post-infarction patients in the cardiac arrhythmia suppression trial (CAST). Similar predictive power was noted in AVID patients with IHD. In CAST the factors defined three groups; one group (5.8%), corresponding to AVID patients that had high risk and benefited from an ICD/PM and another group (17.2%) corresponding to patients in AVID where the risk was moderate and ICD/PM and amiodarone had equal efficacy, demonstrated a two-fold higher risk of sudden arrhythmic than non-arrhythmic death and hence would be expected to benefit from antiarrhythmia therapy. The third group, corresponding to AVID patients with low risk of arrhythmia, demonstrated similar and low risks of sudden arrhythmic and non-arrhythmic death. Thus this group (77%) is unlikely to benefit from indiscriminate antiarrhythmia therapy. Onset of risk of death in CAST patients was offset from randomization by 3 to 6 months. Readily available clinical criteria identify a small group likely to benefit from an ICD/PM after recent myocardial infarction (MI) and the remainder unlikely to benefit from nonselective ICD/PM therapy. Additional risk stratification should focus on the latter patients and be timed to allow ICD/PM implantation between 2 and 6 months after MI.

  15. Evaluation of the new architect cytomegalovirus immunoglobulin M (IgM), IgG, and IgG avidity assays.

    Science.gov (United States)

    Lagrou, K; Bodeus, M; Van Ranst, M; Goubau, P

    2009-06-01

    A panel of new cytomegalovirus (CMV) assays for use on the Architect instrument has been developed, including a CMV avidity assay based on a new technology. The purpose of this study was to compare the performance characteristics of the fully automated CMV immunoglobulin M (IgM), IgG, and IgG avidity tests on the Architect instrument with those of other available assays. A total of 503 consecutive fresh patient serum specimens (routine serum specimens) and 96 serum specimens from 33 pregnant women with a recent CMV primary infection (seroconversion serum specimens) were tested for CMV IgM and IgG by the Architect (Abbott), Vidas (BioMérieux), and Enzygnost (Siemens) assays. The seroconversion sera and 100 preselected serum specimens IgM negative and IgG positive by the AxSYM assay were also tested by the IgG avidity tests on the Architect and Vidas instruments. The relative agreements for CMV IgM determination with routine sera between the Architect assay and the Vidas, Enzygnost, and AxSYM assays were 97%, 94%, and 93%, respectively, for the CMV IgM tests and 99%, 98%, and 98%, respectively, for the CMV IgG tests. The specificities of the CMV IgG avidity test were 98% for the Architect assay and 76% for the Vidas assay. No high CMV IgG avidity test results were found within the first 3 months after seroconversion by either of those assays. The correlation between the results of the newly developed CMV IgM and IgG tests on the Architect instrument with the Vidas and Enzygnost assays was excellent (> or = 94%). The CMV IgG avidity test reliably excluded patients with recent infections and showed an excellent specificity (98%).

  16. Evaluation of the New Architect Cytomegalovirus Immunoglobulin M (IgM), IgG, and IgG Avidity Assays▿

    Science.gov (United States)

    Lagrou, K.; Bodeus, M.; Van Ranst, M.; Goubau, P.

    2009-01-01

    A panel of new cytomegalovirus (CMV) assays for use on the Architect instrument has been developed, including a CMV avidity assay based on a new technology. The purpose of this study was to compare the performance characteristics of the fully automated CMV immunoglobulin M (IgM), IgG, and IgG avidity tests on the Architect instrument with those of other available assays. A total of 503 consecutive fresh patient serum specimens (routine serum specimens) and 96 serum specimens from 33 pregnant women with a recent CMV primary infection (seroconversion serum specimens) were tested for CMV IgM and IgG by the Architect (Abbott), Vidas (BioMérieux), and Enzygnost (Siemens) assays. The seroconversion sera and 100 preselected serum specimens IgM negative and IgG positive by the AxSYM assay were also tested by the IgG avidity tests on the Architect and Vidas instruments. The relative agreements for CMV IgM determination with routine sera between the Architect assay and the Vidas, Enzygnost, and AxSYM assays were 97%, 94%, and 93%, respectively, for the CMV IgM tests and 99%, 98%, and 98%, respectively, for the CMV IgG tests. The specificities of the CMV IgG avidity test were 98% for the Architect assay and 76% for the Vidas assay. No high CMV IgG avidity test results were found within the first 3 months after seroconversion by either of those assays. The correlation between the results of the newly developed CMV IgM and IgG tests on the Architect instrument with the Vidas and Enzygnost assays was excellent (≥94%). The CMV IgG avidity test reliably excluded patients with recent infections and showed an excellent specificity (98%). PMID:19339470

  17. Relation between primary tumor FDG avidity and site of first distant metastasis in patients with breast cancer.

    Science.gov (United States)

    Lim, Chae Hong; Moon, Seung Hwan; Cho, Young Seok; Im, Young-Hyuck; Choe, Yearn Seong; Kim, Byung-Tae; Lee, Kyung-Han

    2016-08-01

    Identification of tumor imaging features associated with metastatic pattern may allow better understanding of cancer dissemination. Here, we investigated how primary tumor F-fluorodeoxyglucose (FDG) avidity influences the first site of breast cancer metastasis.Subjects were 264 patients with advanced breast cancer who underwent positron emission tomography/computed tomography at diagnosis and had metastasis at presentation (n = 193) or metastatic relapse after surgery (n = 71). Primary tumor FDG avidity (maximum SUV [SUVmax] ≥10.1) was compared with histology and first metastatic sites.The most common site of first metastasis was the bone, occurring in 62.7% of patients with metastasis at presentation and 38.0% of those with metastatic relapse. First metastasis to lung occurred in 30.1% and 35.2%, and to liver in 25.4% and 15.2% of respective groups. In patients with metastasis at presentation, primary tumors were FDG avid in 98/193 cases, and this was associated with more frequent first metastasis to lung (37.8% vs 22.1%; P = 0.018). In patients with metastasis relapse, primary tumors were FDG avid in 31/71 cases, and this was associated with more frequent first metastasis to lung (48.4% vs 25.0%; P = 0.041) and liver (29.0% vs 5.0%; P = 0.008). In patients with metastasis relapse, primary tumors that were FDG avid but hormone receptor negative had more first metastasis to lung (57.9% vs 26.9%; P = 0.016).FDG-avid primary breast tumors have favored first spread to the lung and liver, which suggests that tumor cells with heightened glycolytic activity better colonize these organs.

  18. Monoclonal Antibodies.

    Science.gov (United States)

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

    1984-01-01

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

  19. Thyroid Antibodies

    Science.gov (United States)

    ... Fungal Infections Gout Graves Disease Guillain-Barré Syndrome Hashimoto Thyroiditis Heart Attack and Acute Coronary Syndrome Heart ... hypothyroidism or hyperthyroidism , such as Graves disease or Hashimoto thyroiditis . Thyroid antibody tests include: Thyroid peroxidase antibody ( ...

  20. Avidity of IgG for rubella: an evaluation of the need for implementation at the Materno-Infantil Presidente Vargas Hospital in Porto Alegre, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    M.M. Reis

    Full Text Available Rubella serum assays performed in the laboratory of the Materno-Infantil Presidente Vargas Hospital (HMIPV from 1998 to 2002 were reviewed to determine if IgG avidity assays should be implemented. IgG was determined using the Enzyme Linked Fluorescent Assay, ELFA, VIDAS® system, bioMérieux or the Microparticle Enzyme Immunoassay, MEIA, Axsym® system, Abbott, and IgM was determined using the ELFA, VIDAS® system, bioMérieux, a capture format assay. Specific IgG was assayed in 2,863 samples, with positive results for 84% of the patients, for the most part with high levels of antibodies. IgM was assayed in 2,851 samples, being positive in 14 (0.49% and inconclusive in 25 (0.88%. Serology for toxoplasmosis was also positive or inconclusive in 5 patients. After a cost-effectiveness analysis, it was decided not to implement avidity assays, considering that the HMIPV is a public institution, with limited funding. Difficulties concerning the integration of the Clinical Pathology Service with the Clinical Staff of the institution were also considered.

  1. Avidity of IgG for rubella: an evaluation of the need for implementation at the Materno-Infantil Presidente Vargas Hospital in Porto Alegre, Rio Grande do Sul, Brazil.

    Science.gov (United States)

    Reis, M M; Tessaro, M M; Cruz e Silva, J; Giordano, S A; d'Azevedo, P A

    2004-06-01

    Rubella serum assays performed in the laboratory of the Materno-Infantil Presidente Vargas Hospital (HMIPV) from 1998 to 2002 were reviewed to determine if IgG avidity assays should be implemented. IgG was determined using the Enzyme Linked Fluorescent Assay, ELFA, VIDAS system, bioMerieux or the Microparticle Enzyme Immunoassay, MEIA, Axsym system, Abbott, and IgM was determined using the ELFA, VIDAS system, bioMerieux, a capture format assay. Specific IgG was assayed in 2,863 samples, with positive results for 84% of the patients, for the most part with high levels of antibodies. IgM was assayed in 2,851 samples, being positive in 14 (0.49%) and inconclusive in 25 (0.88%). Serology for toxoplasmosis was also positive or inconclusive in 5 patients. After a cost-effectiveness analysis, it was decided not to implement avidity assays, considering that the HMIPV is a public institution, with limited funding. Difficulties concerning the integration of the Clinical Pathology Service with the Clinical Staff of the institution were also considered.

  2. DNA vaccination with T-cell epitopes encoded within Ab molecules induces high-avidity anti-tumor CD8+ T cells.

    Science.gov (United States)

    Pudney, Victoria A; Metheringham, Rachael L; Gunn, Barbara; Spendlove, Ian; Ramage, Judith M; Durrant, Lindy G

    2010-03-01

    Stimulation of high-avidity CTL responses is essential for effective anti-tumor and anti-viral vaccines. In this study we have demonstrated that a DNA vaccine incorporating CTL epitopes within an Ab molecule results in high-avidity T-cell responses to both foreign and self epitopes. The avidity and frequency was superior to peptide, peptide-pulsed DC vaccines or a DNA vaccine incorporating the epitope within the native Ag. The DNA Ab vaccine was superior to an identical protein vaccine that can only cross-present, indicating a role for direct presentation by the DNA vaccine. However, the avidity of CTL responses was significantly reduced in Fc receptor gamma knockout mice or if the Fc region was removed suggesting that cross presentation of Ag via Fc receptor was also important in the induction of high-avidity CTL. These results suggest that generation of high-avidity CTL responses by the DNA vaccine is related to its ability to both directly present and cross-present the epitope. High-avidity responses were capable of efficient anti-tumor activity in vitro and in vivo. This study demonstrates a vaccine strategy to generate high-avidity CTL responses that can be used in anti-tumor and anti-viral vaccine settings.

  3. Partial blood meal, carbohydrate availability, and blood-feeding postponement effects on human host avidity and DEET repellency in Aedes albopictus (Diptera: Culicidae)

    Science.gov (United States)

    Host avidity and DEET repellency were measured in partially blood fed Aedes albopictus (Skuse) provided 10% sucrose in water, water, or neither when access to a human host was postponed for 1 to 72 h after a partial blood meal. Carbohydrate availability and post-feeding time influenced host avidity...

  4. Single immunization with a suboptimal antigen dose encapsulated into polyanhydride microparticles promotes high titer and avid antibody responses

    Science.gov (United States)

    Microparticle adjuvants based on biodegradable polyanhydrides were used to provide controlled delivery of a model antigen, ovalbumin (Ova), to mice. Ova was encapsulated into two different polyanhydride microparticle formulations to evaluate the influence of polymer chemistry on the nature and magn...

  5. A hot L1 retrotransposon evades somatic repression and initiates human colorectal cancer

    Science.gov (United States)

    Scott, Emma C.; Gardner, Eugene J.; Masood, Ashiq; Chuang, Nelson T.; Vertino, Paula M.; Devine, Scott E.

    2016-01-01

    Although human LINE-1 (L1) elements are actively mobilized in many cancers, a role for somatic L1 retrotransposition in tumor initiation has not been conclusively demonstrated. Here, we identify a novel somatic L1 insertion in the APC tumor suppressor gene that provided us with a unique opportunity to determine whether such insertions can actually initiate colorectal cancer (CRC), and if so, how this might occur. Our data support a model whereby a hot L1 source element on Chromosome 17 of the patient's genome evaded somatic repression in normal colon tissues and thereby initiated CRC by mutating the APC gene. This insertion worked together with a point mutation in the second APC allele to initiate tumorigenesis through the classic two-hit CRC pathway. We also show that L1 source profiles vary considerably depending on the ancestry of an individual, and that population-specific hot L1 elements represent a novel form of cancer risk. PMID:27197217

  6. Evading the pulsar constraints on the cosmic string tension in supergravity inflation

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Miyamoto, Yuhei [Tokyo Univ. (Japan). Dept. of Physics; Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Yokoyama, Jun' ichi [Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Tokyo Univ., Kashiwa, Chiba (JP). Inst. for the Physics and Mathematics of the Universe (IPMU)

    2012-04-15

    The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales where any artificial particle accelerators cannot reach. Although one of the most promising tools is the cosmic microwave background, the constraint from gravitational waves is becoming so stringent that one may not hope to detect its signatures in the cosmic microwave background. In this paper, we construct a scenario that contains cosmic strings observable in the cosmic microwave background while evading the constraint imposed by the recent pulsar timing data. We argue that cosmic strings with relatively large tension are allowed by delaying the onset of the scaling regime. We also show that this scenario is naturally realized in the context of chaotic inflation in supergravity, where the phase transition is governed by the Hubble induced mass.

  7. Antibody Responses in the Nonhuman Primate, Macaca Fascicularis, to Protein Toxins

    Science.gov (United States)

    1990-05-01

    avidity in rabbits after immunization with dinitrophenyl bovine gamma-globulin (DNP-BGG) using equilibrium dialysis and fluorescence quenching...MacDonald (1988) compared this modified EUSA to a very accurate contemporary but more cumbersome technique (equilibrium dialysis ) and demonstrated similar...antibody does not necessarily confer functional adequacy. The response must fulfill tr-e criteria in order to confront the antigenic challenge

  8. Characterizing Antibodies.

    Science.gov (United States)

    Weis-Garcia, Frances; Carnahan, Robert H

    2017-11-01

    Perhaps because they are such commonly used tools, many researchers view antibodies one-dimensionally: Antibody Y binds antigen X. Although few techniques require a comprehensive understanding of any particular antibody's characteristics, well-executed experiments do require a basic appreciation of what is known and, equally as important, what is not known about the antibody being used. Ignorance of the relevant antibody characteristics critical for a particular assay can easily lead to loss of precious resources (time, money, and limiting amounts of sample) and, in worst-case scenarios, erroneous conclusions. Here, we describe various antibody characteristics to provide a more well-rounded perspective of these critical reagents. With this information, it will be easier to make informed decisions on how best to choose and use the available antibodies, as well as knowing when it is essential and how to determine a particular as yet-undefined characteristic. © 2017 Cold Spring Harbor Laboratory Press.

  9. 18F-NaF Positive Bone Metastases of Non 18F-FDG Avid Mucinous Gastric Cancer

    OpenAIRE

    Çiğdem Soydal; Elgin Özkan; Özlem Nuriye Küçük

    2015-01-01

    Detection of gastric cancer bone metastasis is crucial since its presence is an independent prognostic factor. In this case report, we would like to present 18F-NaF positive bone metastases of non 18F-FDG avid gastric mucinous cancer.

  10. Evaluation of Norepinephrine Transporter Expression and Metaiodobenzylguanidine Avidity in Neuroblastoma: A Report from the Children's Oncology Group

    Directory of Open Access Journals (Sweden)

    Steven G. DuBois

    2012-01-01

    Full Text Available Purpose. 123I-metaiodobenzylguanidine (MIBG is used for the diagnostic evaluation of neuroblastoma. We evaluated the relationship between norepinephrine transporter (NET expression and clinical MIBG uptake. Methods. Quantitative reverse transcription PCR (N=82 and immunohistochemistry (IHC; N=61 were performed for neuroblastoma NET mRNA and protein expression and correlated with MIBG avidity on diagnostic scans. The correlation of NET expression with clinical features was also performed. Results. Median NET mRNA expression level for the 19 MIBG avid patients was 12.9% (range 1.6–73.7% versus 5.9% (range 0.6–110.0% for the 8 nonavid patients (P=0.31. Median percent NET protein expression was 50% (range 0–100% in MIBG avid patients compared to 10% (range 0–80% in nonavid patients (P=0.027. MYCN amplified tumors had lower NET protein expression compared to nonamplified tumors (10% versus 50%; P=0.0002. Conclusions. NET protein expression in neuroblastoma correlates with MIBG avidity. MYCN amplified tumors have lower NET protein expression.

  11. HIV avidity index performance using a modified fourth-generation immunoassay to detect recent HIV infections.

    Science.gov (United States)

    Suligoi, Barbara; Regine, Vincenza; Raimondo, Mariangela; Rodella, Anna; Terlenghi, Luigina; Caruso, Arnaldo; Bagnarelli, Patrizia; Capobianchi, Maria Rosaria; Zanchetta, Nadia; Ghisetti, Valeria; Galli, Claudio

    2017-10-26

    Detecting recent HIV infections is important to evaluate incidence and monitor epidemic trends. We aimed to evaluate the diagnostic performance and accuracy of the avidity index (AI) for discriminating for recent HIV infections. We collected serum samples from HIV-1 positive individuals: A) with known date of infection (midpoint in time between last HIV-negative and first HIV-positive test); B) infected for >1 year. Samples were divided into two aliquots: one diluted with phosphate buffered saline (PBS) and the other with 1 M guanidine. Both aliquots were assayed by the Architect HIV Ag/Ab Combo 4th generation assay (Abbott). We compared AI found in recent (RI=HIV subtype had no impact on AI misclassifications. All individuals in group A reached the AI threshold of 0.80 within 24 months after seroconversion. The AI is an accurate serological marker for discriminating recent from established HIV infections and meets WHO requirements for HIV incidence assays.

  12. Comparison of antibody responses to HIV infection in Ugandan women infected with HIV subtypes A and D.

    Science.gov (United States)

    Longosz, Andrew F; Morrison, Charles S; Chen, Pai-Lien; Brand, Hilmarie H; Arts, Eric; Nankya, Immaculate; Salata, Robert A; Quinn, Thomas C; Eshleman, Susan H; Laeyendecker, Oliver

    2015-04-01

    We compared the serologic response to HIV infection in Ugandan women with HIV subtype A (N=82) and D (N=32) infection using a limiting antigen avidity assay (LAg-Avidity assay); 2,614 samples were analyzed. Study participants were followed a median of 6.6 years after HIV seroconversion. Samples were classified as assay positive if they had a LAg-Avidity assay result infection were more likely to have delayed antibody maturation. During the first 2 years after seroconversion, the mean time that women had an assay-positive result (mean duration of recent infection, MDRI) was longer for women with subtype D infection than women with subtype A infection (267.9 days, 95% CI: 231.2-308.2 vs. 167.3 days, 95% CI: 151.8-185.9 days, pinfection after excluding low viral load samples and samples from women on antiretroviral therapy (ART). Women infected for >2 years were also more likely to be misclassified as recently infected in they had subtype D infection. Women with subtype D infection were also more likely to have antibody waning compared to women with subtype A infection. These findings may be related to the higher pathogenicity of subtype D HIV infection and are relevant to use of the LAg-Avidity assay for cross-sectional HIV incidence estimation in populations where subtype D infection is prevalent.

  13. Mercury-nutrient signatures in seafood and in the blood of avid seafood consumers.

    Science.gov (United States)

    Karimi, Roxanne; Fisher, Nicholas S; Meliker, Jaymie R

    2014-10-15

    Dietary recommendations for seafood are confusing due to the desire to balance both benefits from nutrients and risks from contaminants. The overall health value of different fish and shellfish items depends on concentrations of multiple nutrients (e.g., selenium (Se), omega-3 fatty acids) and contaminants (e.g., mercury (Hg)). However, few studies have examined the connections between human exposure to multiple nutrients and contaminants and the consumption of specific types of seafood. Our goals were to compare 1) Hg, Se and omega-3 fatty acid concentrations (Hg-nutrient signatures) among common fish and shellfish items and 2) Hg-nutrient signatures in the blood of avid seafood consumers, based on seafood consumption habits. We compiled nutrient and Hg concentration data for common fish and shellfish items from the literature. We also measured blood concentrations of Hg and seafood nutrients collected from adult, avid seafood consumers on Long Island, NY. Canonical discriminant analyses revealed distinct Hg-nutrient signatures among seafood items, and these signatures were reflected in the blood of consumers based on different consumption habits. For example, consumers with a salmon-dominated seafood diet had relatively high percentage of omega-3 fatty acids in blood, and consumers who tend to eat top predator seafood have higher Hg, but similar blood nutrient concentrations compared to consumers who tend to eat low trophic level seafood. These results provide direct evidence of links between the ecological characteristics of the type of seafood consumed and Hg-nutrient exposure. This approach helps assess the overall human health value of specific seafood types, leads to specific diet recommendations, and can be used to characterize risk:benefit status among seafood consumers. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Tallinna Merepäevade turismikonverents käsitles mere ja linna kohtumispaiga arenguid ja arendamist / Ain Hinsberg

    Index Scriptorium Estoniae

    Hinsberg, Ain

    2013-01-01

    Tallinna Sadama, linnavalitsuse, Viking Line ja EHTE poolt 12. juulil Admiraliteedi basseiniääres Merepäevade paviljonis korraldatud konverentsist "Mere ja linna kohtumispaik kui linnaruum ja sihtkoht", kus esinesid Allan Kiil, Tiit Kask, Duncan Frazer Inglismaalt, Satu Lehtonen Soomest, Anu Hallik-Jürgenstein, Peeter Pere, Heikki Mäki, Evelyn Sepp ja Ahto Ader

  15. Formulation of a Cooperative-Confinement-Escape problem of multiple cooperative defenders against an evader escaping from a circular region

    Science.gov (United States)

    Li, Wei

    2016-10-01

    In this paper, we propose and formulate the Cooperative-Confinement-Escape (CCE) problem of multiple cooperative defenders against an evader escaping from a circular region, in which the defenders are moving on the circle with attempt to prevent possible escape of a single evader who is initially located inside the circle. The main contributions are summarized as follows: (1) we first provide an effective formulation of the CCE problem, which is an emphasis of this paper, with design of two nonlinear control strategies for the cooperative defenders and the adversarial evader, respectively. Particularly, we consider to include a proper interaction between each pair of the nearest-neighbor defenders, and an adaptive trajectory prediction mechanism in the strategies of the defenders to increase the chance of successful confinement. (2) For the first attempt on analyzing the CCE dynamics which is unavoidably strongly nonlinear, we analyze the minimum energy of the evader for possible escape. (3) For understanding of the behaviors of the system under different parameters, (i) we illustrate the effectiveness of the confinement strategy using the adaptive trajectory prediction mechanism, and (ii) the physical roles of the system parameters with respect to the system dynamics, some of which may be unexpected or not straightforward. A separate paper will be presented for systematic analysis of the agents' behaviors with respect to the large intervals of the parameter settings.

  16. Lübecki filmipäevad 1999 ja Thomas Manni ekraniseering 1923 / Lauri Kärk

    Index Scriptorium Estoniae

    Kärk, Lauri, 1954-

    1999-01-01

    4.-7. novembrini Lübeckis toimunud Põhjamaade filmipäevade 41. Nordische Filmtage huvitavamatest filmidest, nagu Thomas Manni "Buddenbrookide" ekraniseering 1923. aastast (režissöör Gerhard Lamprecht) ja Rasmus Gerlachi dokumentaal "Operaator Kaufman" Dziga Vertovist ja tema kahest, samuti kino alal tegutsenud vennast

  17. Supersensitive gastrin assay using antibodies raised against a cholecystokinin homolog.

    Science.gov (United States)

    Rehfeld, Jens F; Ericsson, Peter

    2012-04-01

    Peptide hormones may occur in particularly low amounts in samples from small animals. Hence, in a rat microdialysis study conventional immunoassays were not sufficiently sensitive to measure gastrin in the dialysis samples. We therefore exploited the observation that antibodies raised against the homologous hormone cholecystokinin (CCK) occasionally bind gastrin peptides with significantly higher affinity than the proper ligand. The immunoassay thus established could detect 1.0 pmol/l in 15 μl microdialysate, which corresponds to 23 attomol gastrin. Such detection limit is five-fold lower than that obtained with the most avid conventional gastrin antibodies. The results may encourage similar approaches for other peptides using homologue-raised antibodies when supersensitivity is required.

  18. Supersensitive gastrin assay using antibodies raised against a cholecystokinin homolog

    DEFF Research Database (Denmark)

    Rehfeld, Jens F; Ericsson, Peter

    2012-01-01

    Peptide hormones may occur in particularly low amounts in samples from small animals. Hence, in a rat microdialysis study conventional immunoassays were not sufficiently sensitive to measure gastrin in the dialysis samples. We therefore exploited the observation that antibodies raised against...... the homologous hormone cholecystokinin (CCK) occasionally bind gastrin peptides with significantly higher affinity than the proper ligand. The immunoassay thus established could detect 1.0 pmol/l in 15 μl microdialysate, which corresponds to 23 attomol gastrin. Such detection limit is five-fold lower than...... that obtained with the most avid conventional gastrin antibodies. The results may encourage similar approaches for other peptides using homologue-raised antibodies when supersensitivity is required....

  19. [The current situation of aggravated intoxication with "kiken" drugs (law-evading drugs)].

    Science.gov (United States)

    Akashi, Akiko; Kashiura, Masahiro; Mikami, Manabu; Hamabe, Yuichi

    2016-03-01

    The intoxication caused by "kiken" drugs (law-evading drugs), such as synthetic cannabinoids, cathinones, and methoxetamine, has recently increased in Japan. We retrospectively examined the characteristics of patients poisoned with the "kiken" drugs. We included patients who presented at the emergency department at the Tokyo Metropolitan Bokutoh Hospital from January 2011 to December 2014. Eighteen patients admitted between January 2011 and December 2013 were included in the early period group and 10 patients admitted between January and December 2014 were categorized into the late period group. The number of the patients transported to our emergency department between 2011 and 2014 increased annually. Patients were mainly admitted between May and October 2014; no patients were admitted after November 2014. The patients' age, history of previous mental disease, habitual use, Triage DOA results, serum creatinine values on admission, and respiratory management differed significantly between the groups. However, the median serum creatinine values of both groups on admission were within the normal level. Patients poisoned with the "kiken" drugs showed more severe symptoms, higher rate of habitual use, and higher average age. The annual increase in the number of the patients observed thus far is expected to decrease in the future. Maintenance of the law and expansion of medical institutions that treat patients addicted to the "kiken" drugs are warranted.

  20. Henipaviruses Employ a Multifaceted Approach to Evade the Antiviral Interferon Response

    Directory of Open Access Journals (Sweden)

    Megan L. Shaw

    2009-12-01

    Full Text Available Hendra and Nipah virus, which constitute the genus Henipavirus, are zoonotic paramyxoviruses that have been associated with sporadic outbreaks of severe disease and mortality in humans since their emergence in the late 1990s. Similar to other paramyxoviruses, their ability to evade the host interferon (IFN response is conferred by the P gene. The henipavirus P gene encodes four proteins; the P, V, W and C proteins, which have all been described to inhibit the antiviral response. Further studies have revealed that these proteins have overlapping but unique properties which enable the virus to block multiple signaling pathways in the IFN response. The best characterized of these is the JAK-STAT signaling pathway which is targeted by the P, V and W proteins via an interaction with the transcription factor STAT1. In addition the V and W proteins can both limit virus-induced induction of IFN but they appear to do this via distinct mechanisms that rely on unique sequences in their C-terminal domains. The ability to generate recombinant Nipah viruses now gives us the opportunity to determine the precise role for each of these proteins and address their contribution to pathogenicity. Additionally, the question of whether these multiple anti-IFN strategies are all active in the different mammalian hosts for henipaviruses, particularly the fruit bat reservoir, warrants further exploration.

  1. Stealth nanotubes: strategies of shielding carbon nanotubes to evade opsonization and improve biodistribution

    Science.gov (United States)

    Kotagiri, Nalinikanth; Kim, Jin-Woo

    2014-01-01

    Carbon nanotubes (CNTs) have recently been in the limelight for their potential role in disease diagnostics and therapeutics, as well as in tissue engineering. Before these medical applications can be realized, there is a need to address issues like opsonization, phagocytosis by macrophages, and sequestration to the liver and spleen for eventual elimination from the body; along with equally important issues such as aqueous solubility, dispersion, biocompatibility, and biofunctionalization. CNTs have not been shown to be able to evade such biological obstacles, which include their nonspecific attachments to cells and other biological components in the bloodstream, before reaching target tissues and cells in vivo. This will eventually determine their longevity in circulation and clearance rate from the body. This review article discusses the current status, challenges, practical strategies, and implementations of coating CNTs with biocompatible and opsonin-resistant moieties, rendering CNTs transparent to opsonins and deceiving the innate immune response to make believe that the CNTs are not foreign. A holistic approach to the development of such “stealth” CNTs is presented, which encompasses not only several biophysicochemical factors that are not limited to surface treatment of CNTs, but also extraneous biological factors such as the protein corona formation that inevitably controls the in vivo fate of the particles. This review also discusses the present and potential applications, along with the future directions, of CNTs and their hybrid-based nanotheranostic agents for multiplex, multimodal molecular imaging and therapy, as well as in other applications, such as drug delivery and tissue engineering. PMID:24872705

  2. Quantum back-action-evading measurement of motion in a negative mass reference frame

    Science.gov (United States)

    Møller, Christoffer B.; Thomas, Rodrigo A.; Vasilakis, Georgios; Zeuthen, Emil; Tsaturyan, Yeghishe; Balabas, Mikhail; Jensen, Kasper; Schliesser, Albert; Hammerer, Klemens; Polzik, Eugene S.

    2017-07-01

    Quantum mechanics dictates that a continuous measurement of the position of an object imposes a random quantum back-action (QBA) perturbation on its momentum. This randomness translates with time into position uncertainty, thus leading to the well known uncertainty on the measurement of motion. As a consequence of this randomness, and in accordance with the Heisenberg uncertainty principle, the QBA puts a limitation—the so-called standard quantum limit—on the precision of sensing of position, velocity and acceleration. Here we show that QBA on a macroscopic mechanical oscillator can be evaded if the measurement of motion is conducted in the reference frame of an atomic spin oscillator. The collective quantum measurement on this hybrid system of two distant and disparate oscillators is performed with light. The mechanical oscillator is a vibrational ‘drum’ mode of a millimetre-sized dielectric membrane, and the spin oscillator is an atomic ensemble in a magnetic field. The spin oriented along the field corresponds to an energetically inverted spin population and realizes a negative-effective-mass oscillator, while the opposite orientation corresponds to an oscillator with positive effective mass. The QBA is suppressed by -1.8 decibels in the negative-mass setting and enhanced by 2.4 decibels in the positive-mass case. This hybrid quantum system paves the way to entanglement generation and distant quantum communication between mechanical and spin systems and to sensing of force, motion and gravity beyond the standard quantum limit.

  3. Close, but no cigar: certain cigars are pseudo-cigarettes designed to evade regulation.

    Science.gov (United States)

    Delnevo, Cristine D; Hrywna, Mary; Giovenco, Daniel P; Miller Lo, Erin J; O'Connor, Richard J

    2017-05-01

    An abundance of evidence suggests that the tobacco industry's response to increased regulation imposed on cigarettes has been the development of little cigars and filtered cigars which are tobacco products that are merely cigarettes in disguise. Emphasising these products' physical attributes, the tobacco industry has offered cigar products to its consumers as pseudo-cigarettes. For decades, tobacco manufacturers' response to increased cigarette regulation and taxation has been to exploit policy loopholes by offering these little cigars and filtered cigars pseudo-cigarettes that are exempted from this regulatory oversight. As a result, in spite of increased regulations and taxes on cigarettes, smokers can purchase cigars that are almost physically indistinguishable from their cigarettes at a lower cost. This commentary describes the recent evolution of the cigar market in response to federal regulation, and highlights historical cigar industry attempts to evade taxation, capitalise on product features that are off-limits to cigarettes, and capture the shrinking market of cigarette smokers. We present the case that little cigars and filtered cigars, differing very little physically from cigarettes, are products deserving the same regulatory scrutiny. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  4. Evading plant immunity: feedback control of the T3SS in Pseudomonas syringae

    Science.gov (United States)

    Waite, Christopher; Schumacher, Jörg; Jovanovic, Milija; Bennett, Mark; Buck, Martin

    2017-01-01

    Microbes are responsible for over 10% of the global yield losses in staple crops such as wheat, rice, and maize. Understanding the decision-making strategies that enable bacterial plant pathogens to evade the host immune system and cause disease is essential for managing their ever growing threat to food security. Many utilise the needle-like type III secretion system (T3SS) to suppress plant immunity, by injecting effector proteins that inhibit eukaryotic signalling pathways into the host cell cytoplasm. Plants can in turn evolve resistance to specific pathogens via recognition and blocking of the T3SS effectors, so leading to an ongoing co-evolutionary ‘arms race’ between pathogen and host pairs. The extracytoplasmic function sigma factor HrpL co-ordinates the expression of the T3SS regulon in the leaf-dwelling Pseudomonas syringae and similar pathogens. Recently, we showed that association of HrpL with a target promoter directly adjacent to the hrpL gene imposes negative autogenous control on its own expression level due to overlapping regulatory elements. Our results suggest that by down-regulating T3SS function, this fine-tuning mechanism enables P. syringae to minimise effector-mediated elicitation of plant immunity. PMID:28435841

  5. Evading Quantum Mechanics: Engineering a Classical Subsystem within a Quantum Environment

    Directory of Open Access Journals (Sweden)

    Mankei Tsang

    2012-09-01

    Full Text Available Quantum mechanics is potentially advantageous for certain information-processing tasks, but its probabilistic nature and requirement of measurement backaction often limit the precision of conventional classical information-processing devices, such as sensors and atomic clocks. Here we show that, by engineering the dynamics of coupled quantum systems, it is possible to construct a subsystem that evades the measurement backaction of quantum mechanics, at all times of interest, and obeys any classical dynamics, linear or nonlinear, that we choose. We call such a system a quantum-mechanics-free subsystem (QMFS. All of the observables of a QMFS are quantum-nondemolition (QND observables; moreover, they are dynamical QND observables, thus demolishing the widely held belief that QND observables are constants of motion. QMFSs point to a new strategy for designing classical information-processing devices in regimes where quantum noise is detrimental, unifying previous approaches that employ QND observables, backaction evasion, and quantum noise cancellation. Potential applications include gravitational-wave detection, optomechanical-force sensing, atomic magnetometry, and classical computing. Demonstrations of dynamical QMFSs include the generation of broadband squeezed light for use in interferometric gravitational-wave detection, experiments using entangled atomic-spin ensembles, and implementations of the quantum Toffoli gate.

  6. Anatomic Distribution of Fluorodeoxyglucose-Avid Para-aortic Lymph Nodes in Patients With Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Takiar, Vinita; Fontanilla, Hiral P.; Eifel, Patricia J.; Jhingran, Anuja; Kelly, Patrick [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Iyer, Revathy B. [Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Levenback, Charles F. [Department of Gynecologic Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang, Yongbin; Dong, Lei [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Klopp, Ann, E-mail: aklopp@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-03-15

    Purpose: Conformal treatment of para-aortic lymph nodes (PAN) in cervical cancer allows dose escalation and reduces normal tissue toxicity. Currently, data documenting the precise location of involved PAN are lacking. We define the spatial distribution of this high-risk nodal volume by analyzing fluorodeoxyglucose (FDG)-avid lymph nodes (LNs) on positron emission tomography/computed tomography (PET/CT) scans in patients with cervical cancer. Methods and Materials: We identified 72 PANs on pretreatment PET/CT of 30 patients with newly diagnosed stage IB-IVA cervical cancer treated with definitive chemoradiation. LNs were classified as left-lateral para-aortic (LPA), aortocaval (AC), or right paracaval (RPC). Distances from the LN center to the closest vessel and adjacent vertebral body were calculated. Using deformable image registration, nodes were mapped to a template computed tomogram to provide a visual impression of nodal frequencies and anatomic distribution. Results: We identified 72 PET-positive para-aortic lymph nodes (37 LPA, 32 AC, 3 RPC). All RPC lymph nodes were in the inferior third of the para-aortic region. The mean distance from aorta for all lymph nodes was 8.3 mm (range, 3-17 mm), and from the inferior vena cava was 5.6 mm (range, 2-10 mm). Of the 72 lymph nodes, 60% were in the inferior third, 36% were in the middle third, and 4% were in the upper third of the para-aortic region. In all, 29 of 30 patients also had FDG-avid pelvic lymph nodes. Conclusions: A total of 96% of PET positive nodes were adjacent to the aorta; PET positive nodes to the right of the IVC were rare and were all located distally, within 3 cm of the aortic bifurcation. Our findings suggest that circumferential margins around the vessels do not accurately define the nodal region at risk. Instead, the anatomical extent of the nodal basin should be contoured on each axial image to provide optimal coverage of the para-aortic nodal compartment.

  7. Performance characteristics of the new ARCHITECT Toxo IgG and Toxo IgG Avidity assays.

    Science.gov (United States)

    Sickinger, Eva; Gay-Andrieu, Françoise; Jonas, Gesa; Schultess, Jan; Stieler, Myriam; Smith, Darwin; Hausmann, Michael; Stricker, René; Stricker, Reto; Dhein, Jens; Braun, Hans-Bertram

    2008-11-01

    The ARCHITECT Toxo IgG and IgG Avidity assays have been developed as a fully automated panel for immune status determination and acute infection exclusion. Resolved relative specificity and sensitivity of the ARCHITECT Toxo IgG assay were 99.6% (1359/1365) and 99.7% (1096/1099) as determined on pregnant females, blood donor, and diagnostic specimens. Seroconversion sensitivity of the ARCHITECT assay was comparable with the AxSYM Toxo IgG assay. The ARCHITECT Toxo IgG Avidity assay detected 100.0% (124/124) of acute phase specimens (ARCHITECT Toxo IgG assay, using recombinant antigens, showed excellent specificity and sensitivity for acute phase as well as past infection specimens. The ARCHITECT Toxoplasmosis panel can be reliably used to rule out acute Toxoplasma gondii infection in pregnant women.

  8. Monoclonal Antibodies.

    Science.gov (United States)

    Geskin, Larisa J

    2015-10-01

    Use of monoclonal antibodies (mAbs) has revolutionized cancer therapy. Approaches targeting specific cellular targets on the malignant cells and in tumor microenvironment have been proved to be successful in hematologic malignancies, including cutaneous lymphomas. mAb-based therapy for cutaneous T-cell lymphoma has demonstrated high response rates and a favorable toxicity profile in clinical trials. Several antibodies and antibody-based conjugates are approved for use in clinical practice, and many more are in ongoing and planned clinical trials. In addition, these safe and effective drugs can be used as pillars for sequential therapies in a rational stepwise manner. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Enhancing the clinical potential of AAV vectors by capsid engineering to evade pre-existing immunity

    Directory of Open Access Journals (Sweden)

    Melissa eBartel

    2011-10-01

    Full Text Available Vectors based on adeno-associated viruses have shown considerable promise in both preclinical models and increasingly in clinical trials. However, one formidable challenge is pre-existing immunity due to widespread exposure to numerous AAV variants and serotypes within the human population, which affect efficacy of clinical trials due to the accompanying high levels of anti-capsid neutralizing antibodies. Transient immunosuppression has promise in mitigating cellular and humoral responses induced by vector application in naïve hosts, but cannot overcome the problem that pre-existing neutralizing antibodies pose towards the goal of safe and efficient gene delivery. Shielding of AAV from antibodies, however, may be possible by covalent attachment of polymers to the viral capsid or by encapsulation of vectors inside biomaterials. In addition, there has been considerable progress in using rational mutagenesis, combinatorial libraries, and directed evolution approaches to engineer capsid variants that are not recognized by anti-AAV antibodies generally present in the human population. While additional progress must be made, such strategies, alone or in combination with immunosuppression to avoid de novo induction of antibodies, have strong potential to significantly enhance the clinical efficacy of AAV vectors.

  10. VHS domains of ESCRT-0 cooperate in high-avidity binding to polyubiquitinated cargo

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Xuefeng; Hurley, James H. (NIH)

    2010-03-30

    VHS (Vps27, Hrs, and STAM) domains occur in ESCRT-0 subunits Hrs and STAM, GGA adapters, and other trafficking proteins. The structure of the STAM VHS domain-ubiquitin complex was solved at 2.6 {angstrom} resolution, revealing that determinants for ubiquitin recognition are conserved in nearly all VHS domains. VHS domains from all classes of VHS-domain containing proteins in yeast and humans, including both subunits of ESCRT-0, bound ubiquitin in vitro. ESCRTs have been implicated in the sorting of Lys63-linked polyubiquitinated cargo. Intact human ESCRT-0 binds Lys63-linked tetraubiquitin 50-fold more tightly than monoubiquitin, though only 2-fold more tightly than Lys48-linked tetraubiquitin. The gain in affinity is attributed to the cooperation of flexibly connected VHS and UIM motifs of ESCRT-0 in avid binding to the polyubiquitin chain. Mutational analysis of all the five ubiquitin-binding sites in yeast ESCRT-0 shows that cooperation between them is required for the sorting of the Lys63-linked polyubiquitinated cargo Cps1 to the vacuole.

  11. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection

    Science.gov (United States)

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-01-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection. PMID:22044420

  12. High-avidity IgA protects the intestine by enchaining growing bacteria.

    Science.gov (United States)

    Moor, Kathrin; Diard, Médéric; Sellin, Mikael E; Felmy, Boas; Wotzka, Sandra Y; Toska, Albulena; Bakkeren, Erik; Arnoldini, Markus; Bansept, Florence; Co, Alma Dal; Völler, Tom; Minola, Andrea; Fernandez-Rodriguez, Blanca; Agatic, Gloria; Barbieri, Sonia; Piccoli, Luca; Casiraghi, Costanza; Corti, Davide; Lanzavecchia, Antonio; Regoes, Roland R; Loverdo, Claude; Stocker, Roman; Brumley, Douglas R; Hardt, Wolf-Dietrich; Slack, Emma

    2017-04-27

    Vaccine-induced high-avidity IgA can protect against bacterial enteropathogens by directly neutralizing virulence factors or by poorly defined mechanisms that physically impede bacterial interactions with the gut tissues ('immune exclusion'). IgA-mediated cross-linking clumps bacteria in the gut lumen and is critical for protection against infection by non-typhoidal Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium). However, classical agglutination, which was thought to drive this process, is efficient only at high pathogen densities (≥108 non-motile bacteria per gram). In typical infections, much lower densities (100-107 colony-forming units per gram) of rapidly dividing bacteria are present in the gut lumen. Here we show that a different physical process drives formation of clumps in vivo: IgA-mediated cross-linking enchains daughter cells, preventing their separation after division, and clumping is therefore dependent on growth. Enchained growth is effective at all realistic pathogen densities, and accelerates pathogen clearance from the gut lumen. Furthermore, IgA enchains plasmid-donor and -recipient clones into separate clumps, impeding conjugative plasmid transfer in vivo. Enchained growth is therefore a mechanism by which IgA can disarm and clear potentially invasive species from the intestinal lumen without requiring high pathogen densities, inflammation or bacterial killing. Furthermore, our results reveal an untapped potential for oral vaccines in combating the spread of antimicrobial resistance.

  13. Thyroid Antibodies

    Science.gov (United States)

    ... Factor Antibody Iron Iron Tests JAK2 Mutation Kidney Stone Analysis Kidney Stone Risk Panel KRAS Mutation Lactate Lactate Dehydrogenase (LD) ... gain Fatigue Dry skin Hair loss Intolerance to cold Constipation A high level of thyroid hormone ( hyperthyroidism ) ...

  14. Emakeelepäevad Riias jätkuvad / Tõnu Karma ; fotod: M. Kulli ja Tõnu Karma

    Index Scriptorium Estoniae

    Karma, Tõnu

    2003-01-01

    12. märtsil 1989. aastal emakeelepäeva tähistamisest Riias, korraldajaks Läti Eesti Selts, ja sama aasta juunis rahvaluulepäevade pidamist, millega tähistati Jakob Hurda 150. sünniaastapäeva, Kristjan Jaak Petersoni 200. sünniaastapäeva tähistamisest ja mälestuskivi püstitamisest Jakobi kalmistule

  15. Enzyme-Mediated Modification of Single-Domain Antibodies for Imaging Modalities with Different Characteristics.

    Science.gov (United States)

    Rashidian, Mohammad; Wang, Lu; Edens, Jerre G; Jacobsen, Johanne T; Hossain, Intekhab; Wang, Qifan; Victora, Gabriel D; Vasdev, Neil; Ploegh, Hidde; Liang, Steven H

    2016-01-11

    Antibodies are currently the fastest-growing class of therapeutics. Although naked antibodies have proven valuable as pharmaceutical agents, they have some limitations, such as low tissue penetration and a long circulatory half-life. They have been conjugated to toxic payloads, PEGs, or radioisotopes to increase and optimize their therapeutic efficacy. Although nonspecific conjugation is suitable for most in vitro applications, it has become evident that site specifically modified antibodies may have advantages for in vivo applications. Herein we describe a novel approach in which the antibody fragment is tagged with two handles: one for the introduction of a fluorophore or (18)F isotope, and the second for further modification of the fragment with a PEG moiety or a second antibody fragment to tune its circulatory half-life or its avidity. Such constructs, which recognize Class II MHC products and CD11b, showed high avidity and specificity. They were used to image cancers and could detect small tumors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Using monoclonal antibodies as an international standard for the measurement of anti-adalimumab antibodies.

    Science.gov (United States)

    van Schouwenburg, Pauline A; Kruithof, Simone; Wolbink, Gertjan; Wouters, Diana; Rispens, Theo

    2016-02-20

    Comparing studies investigating anti-drug antibody (ADA) formation is hampered by the lack of comparability between study protocols, assay formats, and standardized reference materials. In this respect, the use of an international standard would mean a major step forward. Here we compared 11 fully human monoclonal antibodies against adalimumab in two assays commonly used for ADA measurement; the bridging ELISA and the antigen binding test (ABT). Our results show non-parallel titration of the monoclonal antibodies in both assays, which we also find for polyclonal ADA sources. Moreover, we observed that the output of the bridging ELISA depends to a large degree on the affinity of the monoclonal antibody. For the ABT, results reflect a combination of affinity and avidity. This suggests that rather than reporting ADA values in nanogram per milliliter, arbitrary units may be more appropriate. Together our data highlight the difficulty of ADA standardization by identifying several pitfalls that should be taken into account when selecting a standard for ADA testing. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Mathematical Modeling of Avidity Distribution and Estimating General Binding Properties of Transcription Factors from Genome-Wide Binding Profiles.

    Science.gov (United States)

    Kuznetsov, Vladimir A

    2017-01-01

    The shape of the experimental frequency distributions (EFD) of diverse molecular interaction events quantifying genome-wide binding is often skewed to the rare but abundant quantities. Such distributions are systematically deviated from standard power-law functions proposed by scale-free network models suggesting that more explanatory and predictive probabilistic model(s) are needed. Identification of the mechanism-based data-driven statistical distributions that provide an estimation and prediction of binding properties of transcription factors from genome-wide binding profiles is the goal of this analytical survey. Here, we review and develop an analytical framework for modeling, analysis, and prediction of transcription factor (TF) DNA binding properties detected at the genome scale. We introduce a mixture probabilistic model of binding avidity function that includes nonspecific and specific binding events. A method for decomposition of specific and nonspecific TF-DNA binding events is proposed. We show that the Kolmogorov-Waring (KW) probability function (PF), modeling the steady state TF binding-dissociation stochastic process, fits well with the EFD for diverse TF-DNA binding datasets. Furthermore, this distribution predicts total number of TF-DNA binding sites (BSs), estimating specificity and sensitivity as well as other basic statistical features of DNA-TF binding when the experimental datasets are noise-rich and essentially incomplete. The KW distribution fits equally well to TF-DNA binding activity for different TFs including ERE, CREB, STAT1, Nanog, and Oct4. Our analysis reveals that the KW distribution and its generalized form provides the family of power-law-like distributions given in terms of hypergeometric series functions, including standard and generalized Pareto and Waring distributions, providing flexible and common skewed forms of the transcription factor binding site (TFBS) avidity distribution function. We suggest that the skewed binding

  18. A comparative analysis of HIV-specific mucosal/systemic T cell immunity and avidity following rDNA/rFPV and poxvirus-poxvirus prime boost immunisations.

    Science.gov (United States)

    Ranasinghe, Charani; Eyers, Fiona; Stambas, John; Boyle, David B; Ramshaw, Ian A; Ramsay, Alistair J

    2011-04-05

    In this study we have firstly compared a range of recombinant DNA poxvirus prime-boost immunisation strategies and shown that combined intramuscular (i.m.) 2× DNA-HIV/intranasal (i.n.) 2× FPV-HIV prime-boost immunisation can generate high-level of HIV-specific systemic (spleen) and mucosal (genito-rectal nodes, vaginal tissues and lung tissues) T cell responses and HIV-1 p24 Gag-specific serum IgG1, IgG2a and mucosal IgG, SIgA responses in vaginal secretions in BALB/c mice. Data indicate that following rDNA priming, two rFPV booster immunisations were necessary to generate good antibody and mucosal T cell immunity. This data also revealed that mucosal uptake of recombinant fowl pox (rFPV) was far superior to plasmid DNA. To further evaluate CD8+ T cell immunity, i.m. 2× DNA-HIV/i.n. 1× FPV-HIV immunisation strategy was directly compared with single shot poxvirus/poxvirus, i.n. FPV-HIV/i.m. VV-HIV immunisation. Results indicate that the latter strategy was able to generate strong sustained HIV-specific CD8+ T cells with higher avidity, broader cytokine/chemokine profiles and better protection following influenza-K(d)Gag(197-205) challenge compared to rDNA poxvirus prime-boost strategy. Our findings further substantiate the importance of vector selection/combination, order and route of delivery when designing effective vaccines for HIV-1. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Impact of antibody subclass and disulfide isoform differences on the biological activity of CD200R and βklotho agonist antibodies.

    Science.gov (United States)

    Grujic, Ognjen; Stevens, Jennitte; Chou, Robert Y-T; Weiszmann, Jennifer V; Sekirov, Laura; Thomson, Christy; Badh, Anita; Grauer, Stephanie; Chan, Brian; Graham, Kevin; Manchulenko, Kathy; Dillon, Thomas M; Li, Yang; Foltz, Ian N

    2017-05-13

    Agonism of cell surface receptors by monoclonal antibodies is dependent not only on its ability to bind the target, but also to deliver a biological signal through receptors to the cell. Immunoglobulin G2 antibodies (IgG2s) are made up of a mixture of distinct isoforms (IgG2-A, -B and A/B), which differ by the disulfide connectivity at the hinge region. When evaluating panels of agonistic antibodies against CD200 receptor (CD200R) or βklotho receptor (βklotho), we noticed striking activity differences of IgG1 or IgG2 antibodies with the same variable domains. For the CD200R antibody, the IgG2 antibody demonstrated higher activity than the IgG1 or IgG4 antibody. More significantly, for βklotho, agonist antibodies with higher biological activity as either IgG2 or IgG1 were identified. In both cases, ion exchange chromatography was able to isolate the bioactivity to the IgG2-B isoform from the IgG2 parental mixture. The subclass-related increase in agonist activity was not correlated with antibody aggregation or binding affinity, but was driven by enhanced avidity for the CD200R antibody. These results add to the growing body of evidence that show that conformational differences in the antibody hinge region can have a dramatic impact on the antibody activity and must be considered when screening and engineering therapeutic antibody candidates. The results also demonstrate that the IgG1 (IgG2-A like) or the IgG2-B form may provide the most active form of agonist antibodies for different antibodies and targets. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Identification of BACE2 as an avid ß-amyloid-degrading protease

    Directory of Open Access Journals (Sweden)

    Abdul-Hay Samer O

    2012-09-01

    Full Text Available Abstract Background Proteases that degrade the amyloid ß-protein (Aß have emerged as key players in the etiology and potential treatment of Alzheimer’s disease (AD, but it is unlikely that all such proteases have been identified. To discover new Aß-degrading proteases (AßDPs, we conducted an unbiased, genome-scale, functional cDNA screen designed to identify proteases capable of lowering net Aß levels produced by cells, which were subsequently characterized for Aß-degrading activity using an array of downstream assays. Results The top hit emerging from the screen was ß-site amyloid precursor protein-cleaving enzyme 2 (BACE2, a rather unexpected finding given the well-established role of its close homolog, BACE1, in the production of Aß. BACE2 is known to be capable of lowering Aß levels via non-amyloidogenic processing of APP. However, in vitro, BACE2 was also found to be a particularly avid AßDP, with a catalytic efficiency exceeding all known AßDPs except insulin-degrading enzyme (IDE. BACE1 was also found to degrade Aß, albeit ~150-fold less efficiently than BACE2. Aß is cleaved by BACE2 at three peptide bonds—Phe19-Phe20, Phe20-Ala21, and Leu34-Met35—with the latter cleavage site being the initial and principal one. BACE2 overexpression in cultured cells was found to lower net Aß levels to a greater extent than multiple, well-established AßDPs, including neprilysin (NEP and endothelin-converting enzyme-1 (ECE1, while showing comparable effectiveness to IDE. Conclusions This study identifies a new functional role for BACE2 as a potent AßDP. Based on its high catalytic efficiency, its ability to degrade Aß intracellularly, and other characteristics, BACE2 represents a particulary strong therapeutic candidate for the treatment or prevention of AD.

  1. Anti-neosporal IgG and IgE antibodies in canine neosporosis.

    Science.gov (United States)

    Jesus, E E V; Almeida, M A O; Atta, A M

    2007-01-01

    Neospora caninum infection provokes neurological disorders, recurrent abortion and death in dogs and cattle. Dogs are both intermediate and definitive host of N. caninum. Thus, the development of sensitive and specific immunoassays to diagnose canine neosporosis is essential to control this disease. This work investigated serum anti-neosporal IgG and IgE antibodies in 140 dogs represented by 30 healthy animals (group I), 11 dogs showing acute N. caninum infection (group II), 50 urban dogs with serological evidence of canine neosporosis in indirect fluorescent antibody test (IFAT) (group III) and 49 urban dogs without clinical and laboratory evidences of neosporosis (group IV). Enzyme-linked immunosorbent assay (ELISA) and western immunoblotting, both using a soluble N. caninum tachyzoite antigen (SNA), investigated these two isotypes of antibodies, while a Urea-ELISA measured the avidity of the IgG antibodies. Anti-Toxoplasma gondii IgG antibodies were also investigated in the animals. Anti-neosporal IgG was found in all animals from groups II and III, whereas 32.7% (16/49) of dogs from group IV were reactive. IgG antibodies of low avidity were demonstrated in dogs from group II (median 35.3%), while animals from groups III and IV had IgG antibodies of high avidity (medians of 61.5% and 61.7% respectively). IgE antibodies were found in four (13.3%) and five (16.6%) dogs from groups III and IV respectively. Dogs presenting acute infection (group II) or chronic infection (group III) had IgG antibodies to several neosporal antigens, mainly of 29-30 and 35 kDa, while 13 of 16 dogs from group IV recognized antigens from 14 to 170 kDa. Antibodies to T. gondii were detected in 36 of 50 (72%) sera from group III and 25 of 49 (51%) sera from group IV. We concluded that IgG-ELISA and Urea-ELISA with SNA may substitute for IFAT in both laboratory routine and epidemiological studies of canine neosporosis.

  2. A consensus envelope protein domain III can induce neutralizing antibody responses against serotype 2 of dengue virus in non-human primates.

    Science.gov (United States)

    Chen, Hsin-Wei; Liu, Shih-Jen; Li, Yi-Shiuan; Liu, Hsueh-Hung; Tsai, Jy-Ping; Chiang, Chen-Yi; Chen, Mei-Yu; Hwang, Chyi-Sing; Huang, Chin-Cheng; Hu, Hui-Mei; Chung, Han-Hsuan; Wu, Sze-Hsien; Chong, Pele; Leng, Chih-Hsiang; Pan, Chien-Hsiung

    2013-07-01

    We have previously demonstrated that vaccination with a subunit dengue vaccine containing a consensus envelope domain III with aluminum phosphate elicits neutralizing antibodies against all four serotypes of dengue virus in mice. In this study, we evaluated the immunogenicity of the subunit dengue vaccine in non-human primates. After vaccination, monkeys that received the subunit vaccine with aluminum phosphate developed a significantly strong and long-lasting antibody response. A specific T cell response with cytokine production was also induced, and this correlated with the antibody response. Additionally, neutralizing antibodies against serotype 2 were detected in two of three monkeys. The increase in serotype-2-specific antibody titers and avidity observed in these two monkeys suggested that a serotype-2-biased antibody response occurs. These data provide evidence that a protective neutralizing antibody response was successfully elicited in non-human primates by the dengue subunit vaccine with aluminum phosphate adjuvant.

  3. Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus

    Science.gov (United States)

    Liao, Hua-Xin; Lynch, Rebecca; Zhou, Tongqing; Gao, Feng; Alam, S. Munir; Boyd, Scott D.; Fire, Andrew Z.; Roskin, Krishna M.; Schramm, Chaim A.; Zhang, Zhenhai; Zhu, Jiang; Shapiro, Lawrence; Mullikin, James C.; Gnanakaran, S.; Hraber, Peter; Wiehe, Kevin; Kelsoe, Garnett; Yang, Guang; Xia, Shi-Mao; Montefiori, David C.; Parks, Robert; Lloyd, Krissey E.; Scearce, Richard M.; Soderberg, Kelly A.; Cohen, Myron; Kaminga, Gift; Louder, Mark K.; Tran, Lillan M.; Chen, Yue; Cai, Fangping; Chen, Sheri; Moquin, Stephanie; Du, Xiulian; Joyce, Gordon M.; Srivatsan, Sanjay; Zhang, Baoshan; Zheng, Anqi; Shaw, George M.; Hahn, Beatrice H.; Kepler, Thomas B.; Korber, Bette T.M.; Kwong, Peter D.; Mascola, John R.; Haynes, Barton F.

    2013-01-01

    Current HIV-1 vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in ~20% of HIV-1-infected individuals, and details of their generation could provide a roadmap for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from time of infection. The mature antibody, CH103, neutralized ~55% of HIV-1 isolates, and its co-crystal structure with gp120 revealed a novel loop-based mechanism of CD4-binding site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the CH103-lineage unmutated common ancestor avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data elucidate the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies and provide insights into strategies to elicit similar antibodies via vaccination. PMID:23552890

  4. Chimeric antibodies.

    Science.gov (United States)

    Kurosawa, Kohei; Lin, Waka; Ohta, Kunihiro

    2014-01-01

    Here we describe a detailed protocol for the one-step preparation of antigen-specific human chimeric immunoglobulin G (IgG) monoclonal antibodies (mAbs) using an in vitro antibody design method referred to as the ADLib (Autonomously Diversifying Library) system. This method employs a chicken B cell line DT40-based library in which the variable regions of the Ig gene loci have been highly diversified by treatment with the histone deacetylase inhibitors. DT40 cells express both membrane-bound and secreted forms of chicken IgM. This property allows a rapid screening and selection of antibody-producing B cells from the library by using magnetic beads conjugated with any antigen of interest. To apply the ADLib system to the direct generation of human chimeric antibody, we have inserted a DNA segment coding for the constant region of human IgG into the chicken IgM heavy-chain locus of DT40 cells by homologous gene targeting. By a mechanism of alternative splicing, the resulting DT40 strain simultaneously expresses chimeric human IgG that contain the same Ig variable region sequences as the membrane-bound chicken IgM displayed at the cell surface. Application of the ADLib system to this human Ig-inserted DT40 strain enables the one-step isolation of human chimeric IgG that is specific for any antigen of interest and can be easily purified for immediate use.

  5. Antibody biotechnology

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... from somatic recombination between variable genes, was made. This topic has preoccupied immunologists includ- ing Ehrlich (side chain theory), Jerne .... natural naïve libraries, syn- thetic naïve and semi-synthetic libraries. Immune antibody libraries. These libraries are constructed with VH (VDJ) and VL.

  6. Catalytic Antibodies

    Indian Academy of Sciences (India)

    systemic lupus erythematosus, multiple sclerosis and rheumatoid arthritis. The importance of natural immunological mechanisms in pro- ducing artificial catalysts is exemplified by the reports describing increased synthesis of esterase antibodies in autoimmune mice compared to normal mice in response to transition-state ...

  7. Recalibration of the Limiting Antigen Avidity EIA to Determine Mean Duration of Recent Infection in Divergent HIV-1 Subtypes

    Science.gov (United States)

    Duong, Yen T.; Kassanjee, Reshma; Welte, Alex; Morgan, Meade; De, Anindya; Dobbs, Trudy; Rottinghaus, Erin; Nkengasong, John; Curlin, Marcel E.; Kittinunvorakoon, Chonticha; Raengsakulrach, Boonyos; Martin, Michael; Choopanya, Kachit; Vanichseni, Suphak; Jiang, Yan; Qiu, Maofeng; Yu, Haiying; Hao, Yan; Shah, Neha; Le, Linh-Vi; Kim, Andrea A.; Nguyen, Tuan Anh; Ampofo, William; Parekh, Bharat S.

    2015-01-01

    Background Mean duration of recent infection (MDRI) and misclassification of long-term HIV-1 infections, as proportion false recent (PFR), are critical parameters for laboratory-based assays for estimating HIV-1 incidence. Recent review of the data by us and others indicated that MDRI of LAg-Avidity EIA estimated previously required recalibration. We present here results of recalibration efforts using >250 seroconversion panels and multiple statistical methods to ensure accuracy and consensus. Methods A total of 2737 longitudinal specimens collected from 259 seroconverting individuals infected with diverse HIV-1 subtypes were tested with the LAg-Avidity EIA as previously described. Data were analyzed for determination of MDRI at ODn cutoffs of 1.0 to 2.0 using 7 statistical approaches and sub-analyzed by HIV-1 subtypes. In addition, 3740 specimens from individuals with infection >1 year, including 488 from patients with AIDS, were tested for PFR at varying cutoffs. Results Using different statistical methods, MDRI values ranged from 88–94 days at cutoff ODn = 1.0 to 177–183 days at ODn = 2.0. The MDRI values were similar by different methods suggesting coherence of different approaches. Testing for misclassification among long-term infections indicated that overall PFRs were 0.6% to 2.5% at increasing cutoffs of 1.0 to 2.0, respectively. Balancing the need for a longer MDRI and smaller PFR (HIV-1 incidence should facilitate application of the LAg-Avidity EIA for worldwide use. PMID:25710171

  8. Radiation Therapy to the Primary and Postinduction Chemotherapy MIBG-Avid Sites in High-Risk Neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Mazloom, Ali; Louis, Chrystal U.; Nuchtern, Jed; Kim, Eugene; Russell, Heidi; Allen-Rhoades, Wendy; Krance, Robert; Paulino, Arnold C., E-mail: apaulino@mdanderson.org

    2014-11-15

    Purpose: Although it is generally accepted that consolidation therapy for neuroblastoma includes irradiation of the primary site and any remaining metaiodobenzylguanidine (MIBG)-avid metastatic sites, limited information has been published regarding the efficacy of this approach. Methods and Materials: Thirty patients with high-risk neuroblastoma were treated at 1 radiation therapy (RT) department after receiving 5 cycles of induction chemotherapy and resection. All patients had at least a partial response after induction therapy, based upon international neuroblastoma response criteria. The primary sites were treated with 24 to 30 Gy whereas the MIBG-avid metastatic sites were treated with 24 Gy. RT was followed by high-dose chemotherapy with autologous stem cell rescue and 6 months of cis-retinoic acid. Results: The 5-year progression-free survival (PFS) and overall survival (OS) rates were 48% and 59%, respectively. The 5-year locoregional control at the primary site was 84%. There were no differences in locoregional control according to degree of primary surgical resection. The 5-year local control rate for metastatic sites was 74%. The 5-year PFS rates for patients with 0, 1, 2, and >3 postinduction MIBG sites were 66%, 57%, 20%, and 0% (P<.0001), respectively, whereas 5-year OS rates were 80%, 57%, 50%, and 0%, respectively (P<.0001). Conclusions: RT to the primary site and postinduction MIBG-positive metastatic sites was associated with 84% and 74% local control, respectively. The number of MIBG-avid sites present after induction chemotherapy and surgery was predictive of progression-free and overall survival.

  9. Loss of Cell Surface CD47 Clustering Formation and Binding Avidity to SIRPα Facilitate Apoptotic Cell Clearance by Macrophages.

    Science.gov (United States)

    Lv, Zhiyuan; Bian, Zhen; Shi, Lei; Niu, Shuo; Ha, Binh; Tremblay, Alexandra; Li, Liangwei; Zhang, Xiugen; Paluszynski, John; Liu, Ming; Zen, Ke; Liu, Yuan

    2015-07-15

    CD47, a self recognition marker expressed on tissue cells, interacts with immunoreceptor SIRPα expressed on the surface of macrophages to initiate inhibitory signaling that prevents macrophage phagocytosis of healthy host cells. Previous studies suggested that cells may lose surface CD47 during aging or apoptosis to enable phagocytic clearance. In the current study, we demonstrate that the level of cell surface CD47 is not decreased, but the distribution pattern of CD47 is altered, during apoptosis. On nonapoptotic cells, CD47 molecules are clustered in lipid rafts forming punctates on the surface, whereas on apoptotic cells, CD47 molecules are diffused on the cell surface following the disassembly of lipid rafts. We show that clustering of CD47 in lipid rafts provides a high binding avidity for cell surface CD47 to ligate macrophage SIRPα, which also presents as clusters, and elicits SIRPα-mediated inhibitory signaling that prevents phagocytosis. In contrast, dispersed CD47 on the apoptotic cell surface is associated with a significant reduction in the binding avidity to SIRPα and a failure to trigger SIRPα signal transduction. Disruption of plasma membrane lipid rafts with methyl-β-cyclodextrin diffuses CD47 clusters, leading to a decrease in the cell binding avidity to SIRPα and a concomitant increase in cells being engulfed by macrophages. Taken together, our study reveals that CD47 normally is clustered in lipid rafts on nonapoptotic cells but is diffused in the plasma membrane when apoptosis occurs; this transformation of CD47 greatly reduces the strength of CD47-SIRPα engagement, resulting in the phagocytosis of apoptotic cells. Copyright © 2015 by The American Association of Immunologists, Inc.

  10. Overcoming Instability of Antibody-Nanomaterial Conjugates: Next Generation Targeted Nanomedicines Using Bispecific Antibodies.

    Science.gov (United States)

    Howard, Christopher B; Fletcher, Nicholas; Houston, Zachary H; Fuchs, Adrian V; Boase, Nathan R B; Simpson, Joshua D; Raftery, Lyndon J; Ruder, Tim; Jones, Martina L; de Bakker, Christopher J; Mahler, Stephen M; Thurecht, Kristofer J

    2016-08-01

    Targeted nanomaterials promise improved therapeutic efficacy, however their application in nanomedicine is limited due to complexities associated with protein conjugations to synthetic nanocarriers. A facile method to generate actively targeted nanomaterials is developed and exemplified using polyethylene glycol (PEG)-functional nanostructures coupled to a bispecific antibody (BsAb) with dual specificity for methoxy PEG (mPEG) epitopes and cancer targets such as epidermal growth factor receptor (EGFR). The EGFR-mPEG BsAb binds with high affinity to recombinant EGFR (KD : 1 × 10(-9) m) and hyperbranched polymer (HBP) consisting of mPEG (KD : 10 × 10(-9) m) and demonstrates higher avidity for HBP compared to linear mPEG. The binding of BsAb-HBP bioconjugate to EGFR on MDA-MB-468 cancer cells is investigated in vitro using a fluorescently labeled polymer, and in in vivo xenograft models by small animal optical imaging. The antibody-targeted nanostructures show improved accumulation in tumor cells compared to non-targeted nanomaterials. This demonstrates a facile approach for tuning targeting ligand density on nanomaterials, by modulating surface functionality. Antibody fragments are tethered to the nanomaterial through simple mixing prior to administration to animals, overcoming the extensive procedures encountered for developing targeted nanomedicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. FDG-avid portal vein tumor thrombosis from hepatocellular carcinoma in contrast-enhanced FDG PET/CT

    Directory of Open Access Journals (Sweden)

    Canh Nguyen

    2015-01-01

    Full Text Available Objective(s: In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT, complicating hepatocellular carcinoma (HCC in contrast-enhanced FDG PET/CT scan. Methods: In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT, which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis. Results: Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%. PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001. FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001. PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6% had no extrahepatic metastasis, 3 cases (33.3% had metastasis of regional lymph nodes, and 1 case (11.1% presented with distant metastasis. The median estimated survival time of patients was 5 months. Conclusion: The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are

  12. Antiparietal cell antibody test

    Science.gov (United States)

    APCA; Anti-gastric parietal cell antibody; Atrophic gastritis - anti-gastric parietal cell antibody; Gastric ulcer - anti-gastric parietal cell antibody; Pernicious anemia - anti-gastric parietal cell antibody; ...

  13. The kinetics of antibody binding to Plasmodium falciparum VAR2CSA PfEMP1 antigen and modelling of PfEMP1 antigen packing on the membrane knobs

    Directory of Open Access Journals (Sweden)

    Arnot David E

    2010-04-01

    Full Text Available Abstract Background Infected humans make protective antibody responses to the PfEMP1 adhesion antigens exported by Plasmodium falciparum parasites to the erythrocyte membrane, but little is known about the kinetics of this antibody-receptor binding reaction or how the topology of PfEMP1 on the parasitized erythrocyte membrane influences antibody association with, and dissociation from, its antigenic target. Methods A Quartz Crystal Microbalance biosensor was used to measure the association and dissociation kinetics of VAR2CSA PfEMP1 binding to human monoclonal antibodies. Immuno-fluorescence microscopy was used to visualize antibody-mediated adhesion between the surfaces of live infected erythrocytes and atomic force microscopy was used to obtain higher resolution images of the membrane knobs on the infected erythrocyte to estimate knob surface areas and model VAR2CSA packing density on the knob. Results Kinetic analysis indicates that antibody dissociation from the VAR2CSA PfEMP1 antigen is extremely slow when there is a high avidity interaction. High avidity binding to PfEMP1 antigens on the surface of P. falciparum-infected erythrocytes in turn requires bivalent cross-linking of epitopes positioned within the distance that can be bridged by antibody. Calculations of the surface area of the knobs and the possible densities of PfEMP1 packing on the knobs indicate that high-avidity cross-linking antibody reactions are constrained by the architecture of the knobs and the large size of PfEMP1 molecules. Conclusions High avidity is required to achieve the strongest binding to VAR2CSA PfEMP1, but the structures that display PfEMP1 also tend to inhibit cross-linking between PfEMP1 antigens, by holding many binding epitopes at distances beyond the 15-18 nm sweep radius of an antibody. The large size of PfEMP1 will also constrain intra-knob cross-linking interactions. This analysis indicates that effective vaccines targeting the parasite's vulnerable

  14. Short Communication: False Recent Ratio of the Limiting-Antigen Avidity Assay and Viral Load Testing Algorithm Among Cameroonians with Long-Term HIV Infection.

    Science.gov (United States)

    Lynch, Briana A; Patel, Eshan U; Courtney, Colleen R; Nanfack, Aubin J; Bimela, Jude; Wang, Xiaohong; Eid, Issa; Quinn, Thomas C; Laeyendecker, Oliver; Nyambi, Phillipe N; Duerr, Ralf; Redd, Andrew D

    2017-11-01

    Current serological assays that are used for cross-sectional HIV incidence estimation have been shown to misclassify individuals with chronic infection. Limited information exists on the performance of cross-sectional incidence assays in Central Africa. HIV-positive individuals from Cameroon who were infected for at least 1 or 2 years were evaluated to determine the false recent ratio (FRR) of a two-assay algorithm, which includes the Limiting Antigen Avidity (LAg-Avidity) assay (normalized optical density units, ODn HIV viral load (>1000 copies/ml). The subject-level FRR was 5.3% (95% confidence interval [CI], 2.1-10.5) for individuals infected for ≥1 year and 3.9% (95% CI, 0.8-11.0) for individuals infected for ≥2 years. These data suggest that the LAg-Avidity plus viral load incidence algorithm may overestimate HIV incidence rates in Central Africa.

  15. Delivering HIV Gagp24 to DCIR Induces Strong Antibody Responses In Vivo.

    Directory of Open Access Journals (Sweden)

    Anne-Laure Flamar

    Full Text Available Targeting dendritic cell-specific endocytic receptors using monoclonal antibodies fused to desired antigens is an approach widely used in vaccine development to enhance the poor immunogenicity of protein-based vaccines and to induce immune responses. Here, we engineered an anti-human DCIR recombinant antibody, which cross-reacts with the homologous cynomolgous macaque receptor and was fused via the heavy chain C-terminus to HIV Gagp24 protein (αDCIR.Gagp24. In vitro, αDCIR.Gagp24 expanded multifunctional antigen-specific memory CD4+ T cells recognizing multiple Gagp24 peptides from HIV-infected patient peripheral blood mononuclear cells. In non human primates, priming with αDCIR.Gagp24 without adjuvant elicited a strong anti-Gagp24 antibody response after the second immunization, while in the non-targeted HIV Gagp24 protein control groups the titers were weak. The presence of the double-stranded RNA poly(I:C adjuvant significantly enhanced the anti-Gagp24 antibody response in all the groups and reduced the discrimination between the different vaccine groups. The avidity of the anti-Gagp24 antibody responses was similar with either αDCIR.Gagp24 or Gagp24 immunization, but increased from medium to high avidity in both groups when poly(I:C was co-administered. This data provides a comparative analysis of DC-targeted and non-targeted proteins for their capacity to induce antigen-specific antibody responses in vivo. This study supports the further development of DCIR-based DC-targeting vaccines for protective durable antibody induction, especially in the absence of adjuvant.

  16. Acute Kidney Injury Induced by Systemic Inflammatory Response Syndrome is an Avid and Persistent Sodium-Retaining State

    Directory of Open Access Journals (Sweden)

    Daniel Vitorio

    2014-01-01

    Full Text Available Acute kidney injury (AKI is a frequent complication of the systemic inflammatory response syndrome (SIRS, which is triggered by many conditions in the intensive care unit, including different types of circulatory shock. One under-recognized characteristic of the SIRS-induced AKI is its avidity for sodium retention, with progressive decreases in urinary sodium concentration (NaU and its fractional excretion (FENa. This phenomenon occurs in parallel with increases in serum creatinine, being only transitorily mitigated by diuretic use. In the present case, we report a situation of two consecutive shocks: the first shock is hemorrhagic in origin and then the second shock is a septic one in the same patient. The SIRS and AKI triggered by the first shock were not completely solved when the second shock occurred. This could be viewed as a persistent avid sodium-retaining state, which may be appreciated even during renal replacement therapy (in the absence of complete anuria and that usually solves only after complete AKI and SIRS resolution. We suggest that decreases in NaU and FENa are major characteristics of SIRS-induced AKI, irrespective of the primary cause, and may serve as additional monitoring tools in its development and resolution.

  17. First preclinical evaluation of mono-[{sup 123}I]iodohypericin as a necrosis-avid tracer agent

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Yicheng; Chen, Feng; Marchal, Guy [University Hospital Gasthuisberg, Department of Radiology, Leuven (Belgium); Huyghe, Dieter; Verbeke, Kristin; Verbruggen, Alfons M.; Bormans, Guy M. [University of Leuven, Laboratory of Radiopharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Leuven (Belgium); Witte, Peter A. de [University of Leuven, Laboratory of Pharmaceutical Biology and Phytopharmacology, Faculty of Pharmaceutical Sciences, Leuven (Belgium); Nuyts, Johan; Mortelmans, Luc [University Hospital Gasthuisberg, Department of Nuclear Medicine, Leuven (Belgium)

    2006-05-15

    We have labelled hypericin, a polyphenolic polycyclic quinone found in St. John's wort (Hypericum perforatum), with{sup 123}I and evaluated mono-[{sup 123}I]iodohypericin (MIH) as a potential necrosis-avid diagnostic tracer agent. MIH was prepared by an electrophilic radioiodination method. The new tracer agent was evaluated in animal models of liver infarction in the rat and heart infarction in the rabbit using single-photon emission computed tomography (SPECT), triphenyltetrazolium chloride (TTC) histochemical staining, serial sectional autoradiography and microscopy, and radioactivity counting techniques. Using in vivo SPECT imaging, hepatic and cardiac infarctions were persistently visualised as well-defined hot spots over 48 h. Preferential uptake of the tracer agent in necrotic tissue was confirmed by perfect match of images from post-mortem TTC staining, autoradiography (ARX) and histology. Radioactivity concentration in infarcted tissues was over 10 times (liver; 3.51% ID/g in necrotic tissue vs 0.38% ID/g in normal tissue at 60 h p.i.) and over 6 times (myocardium; 0.36% ID/g in necrotic tissue vs 0.054% ID/g in normal tissue; ratios up to 18 for selected parts on ARX images) higher than in normal tissues. The results suggest that hypericin derivatives may serve as powerful necrosis-avid diagnostic agents for assessment of tissue viability. (orig.)

  18. Salmonella Modulates B Cell Biology to Evade CD8+ T Cell-Mediated Immune Responses

    Science.gov (United States)

    Lopez-Medina, Marcela; Perez-Lopez, Araceli; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2014-01-01

    Although B cells and antibodies are the central effectors of humoral immunity, B cells can also produce and secrete cytokines and present antigen to helper T cells. The uptake of antigen is mainly mediated by endocytosis; thus, antigens are often presented by MHC-II molecules. However, it is unclear if B cells can present these same antigens via MHC-I molecules. Recently, Salmonella bacteria were found to infect B cells, allowing possible antigen cross-processing that could generate bacterial peptides for antigen presentation via MHC-I molecules. Here, we will discuss available knowledge regarding Salmonella antigen presentation by infected B cell MHC-I molecules and subsequent inhibitory effects on CD8+ T cells for bacterial evasion of cell-mediated immunity. PMID:25484884

  19. Antibody Engineering and Therapeutics

    Science.gov (United States)

    Almagro, Juan Carlos; Gilliland, Gary L; Breden, Felix; Scott, Jamie K; Sok, Devin; Pauthner, Matthias; Reichert, Janice M; Helguera, Gustavo; Andrabi, Raiees; Mabry, Robert; Bléry, Mathieu; Voss, James E; Laurén, Juha; Abuqayyas, Lubna; Barghorn, Stefan; Ben-Jacob, Eshel; Crowe, James E; Huston, James S; Johnston, Stephen Albert; Krauland, Eric; Lund-Johansen, Fridtjof; Marasco, Wayne A; Parren, Paul WHI; Xu, Kai Y

    2014-01-01

    The 24th Antibody Engineering & Therapeutics meeting brought together a broad range of participants who were updated on the latest advances in antibody research and development. Organized by IBC Life Sciences, the gathering is the annual meeting of The Antibody Society, which serves as the scientific sponsor. Preconference workshops on 3D modeling and delineation of clonal lineages were featured, and the conference included sessions on a wide variety of topics relevant to researchers, including systems biology; antibody deep sequencing and repertoires; the effects of antibody gene variation and usage on antibody response; directed evolution; knowledge-based design; antibodies in a complex environment; polyreactive antibodies and polyspecificity; the interface between antibody therapy and cellular immunity in cancer; antibodies in cardiometabolic medicine; antibody pharmacokinetics, distribution and off-target toxicity; optimizing antibody formats for immunotherapy; polyclonals, oligoclonals and bispecifics; antibody discovery platforms; and antibody-drug conjugates. PMID:24589717

  20. Influence of intermittent preventive treatment on antibodies to VAR2CSA in pregnant Cameroonian women

    DEFF Research Database (Denmark)

    Babakhanyan, Anna; Tutterrow, Yeung L; Bobbili, Naveen

    2016-01-01

    Intermittent preventive treatment (IPT) and insecticide-treated bed nets are the standard of care for preventing malaria in pregnant women. Since these preventive measures reduce exposure to malaria, their influence on the antibody (Ab) response to the parasite antigen VAR2CSA was evaluated...... in pregnant Cameroonian women exposed to holoendemic malaria. Ab levels to full-length VAR2CSA (FV2), variants of the six Duffy binding like (DBL) domains, and proportion of high avidity Ab to FV2 were measured longitudinally in 92 women before and 147 women after IPT. As predicted, reduced exposure...

  1. Human plasma contains cross-reactive Abeta conformer-specific IgG antibodies.

    Science.gov (United States)

    O'Nuallain, Brian; Acero, Luis; Williams, Angela D; Koeppen, Helen P McWilliams; Weber, Alfred; Schwarz, Hans P; Wall, Jonathan S; Weiss, Deborah T; Solomon, Alan

    2008-11-25

    Two conformers of aggregated Abeta, i.e., fibrils and oligomers, have been deemed important in the pathogenesis of Alzheimer's disease. We now report that intravenous immune globulin (IVIG) derived from pools of human plasma contains IgGs that recognize conformational epitopes present on fibrils and oligomers, but not their soluble monomeric precursor. We have used affinity chromatography to isolate these antibodies and have shown that they cross-reacted with comparable nanomolar avidity with both types of Abeta aggregates; notably, binding was not inhibited by soluble Abeta monomers. Our studies provide further support for investigating the therapeutic use of IVIG in Alzheimer's disease.

  2. An improved haemolytic plaque assay for the detection of cells secreting antibody to bacterial antigens

    DEFF Research Database (Denmark)

    Barington, T; Heilmann, C

    1992-01-01

    Recent advances in the development of conjugate polysaccharide vaccines for human use have stimulated interest in the use of assays detecting antibody-secreting cells (AbSC) with specificity for bacterial antigens. Here we present improved haemolytic plaque-forming cell (PFC) assays detecting Ab......SC with specificity for tetanus and diphtheria toxoid as well as for Haemophilus influenzae type b and pneumococcal capsular polysaccharides. These assays were found to be less time consuming, more economical and yielded 1.9-3.4-fold higher plaque numbers than traditional Jerne-type PFC assays. In the case of anti......-polysaccharide antibodies aggregation of secreted monomeric antibody (IgG) is critical for plaque formation and increases the avidity of binding to target cells....

  3. Plasmablast-derived polyclonal antibody response after influenza vaccination.

    Science.gov (United States)

    He, Xiao-Song; Sasaki, Sanae; Narvaez, Carlos F; Zhang, Caiqiu; Liu, Hui; Woo, Jennifer C; Kemble, George W; Dekker, Cornelia L; Davis, Mark M; Greenberg, Harry B

    2011-02-28

    avidity based on antigen specific binding and antibody quantity. Therefore this assay is particularly useful for studying vaccine/infection-induced antibodies against antigens that might have previously circulated, such as antibody responses to rotavirus, dengue or influenza viruses in which cross-reactive antibodies against different virus serotypes/subtypes play a critical role in immunity and/or pathogenesis. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. IgG recognizing 21-24 kDa and 30-33 kDa tachyzoite antigens show maximum avidity maturation during natural and accidental human toxoplasmosis

    Directory of Open Access Journals (Sweden)

    VILLAVEDRA Margarita

    1999-01-01

    Full Text Available We describe the avidity maturation of IgGs in human toxoplasmosis using sequential serum samples from accidental and natural infections. In accidental cases, avidity increased continuously throughout infection while naturally infected patients showed a different profile. Twenty-five percent of sera from chronic patients having specific IgM positive results could be appropriately classified using exclusively the avidity test data. To take advantage of the potentiality of this technique, antigens recognized by IgG showing steeper avidity maturation were identified using immunoblot with KSCN elution. Two clusters of antigens, in the ranges of 21-24 kDa and 30-33 kDa, were identified as the ones that fulfill the aforementioned avidity characteristics.

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

    Directory of Open Access Journals (Sweden)

    Felix Hart

    2017-05-01

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

  6. A Peptide Mimetic of 5-Acetylneuraminic Acid-Galactose Binds with High Avidity to Siglecs and NKG2D.

    Directory of Open Access Journals (Sweden)

    Laura L Eggink

    Full Text Available We previously identified several peptide sequences that mimicked the terminal sugars of complex glycans. Using plant lectins as analogs of lectin-type cell-surface receptors, a tetravalent form of a peptide with the sequence NPSHPLSG, designated svH1C, bound with high avidity to lectins specific for glycans with terminal 5-acetylneuraminic acid (Neu5Ac-galactose (Gal/N-acetylgalactosamine (GalNAc sequences. In this report, we show by circular dichroism and NMR spectra that svH1C lacks an ordered structure and thus interacts with binding sites from a flexible conformation. The peptide binds with high avidity to several recombinant human siglec receptors that bind preferentially to Neu5Ac(α2,3Gal, Neu5Ac(α2,6GalNAc or Neu5Ac(α2,8Neu5Ac ligands. In addition, the peptide bound the receptor NKG2D, which contains a lectin-like domain that binds Neu5Ac(α2,3Gal. The peptide bound to these receptors with a KD in the range of 0.6 to 1 μM. Binding to these receptors was inhibited by the glycoprotein fetuin, which contains multiple glycans that terminate in Neu5Ac(α2,3Gal or Neu5Ac(α2,6Gal, and by sialyllactose. Binding of svH1C was not detected with CLEC9a, CLEC10a or DC-SIGN, which are lectin-type receptors specific for other sugars. Incubation of neuraminidase-treated human peripheral blood mononuclear cells with svH1C resulted in binding of the peptide to a subset of the CD14+ monocyte population. Tyrosine phosphorylation of siglecs decreased dramatically when peripheral blood mononuclear cells were treated with 100 nM svH1C. Subcutaneous, alternate-day injections of svH1C into mice induced several-fold increases in populations of several types of immune cells in the peritoneal cavity. These results support the conclusion that svH1C mimics Neu5Ac-containing sequences and interacts with cell-surface receptors with avidities sufficient to induce biological responses at low concentrations. The attenuation of inhibitory receptors suggests that svH1C

  7. Envelope-specific antibodies and antibody-derived molecules for treating and curing HIV infection

    Science.gov (United States)

    Ferrari, Guido; Haynes, Barton F.; Koenig, Scott; Nordstrom, Jeffrey L.; Margolis, David M.; Tomaras, Georgia D.

    2017-01-01

    HIV-1 is a retrovirus that integrates into host chromatin and can remain transcriptionally quiescent in a pool of immune cells. This characteristic enables HIV-1 to evade both host immune responses and antiretroviral drugs, leading to persistent infection. Upon reactivation of proviral gene expression, HIV-1 envelope (HIV-1 Env) glycoproteins are expressed on the cell surface, transforming latently infected cells into targets for HIV-1 Env-specific monoclonal antibodies (mAbs), which can engage immune effector cells to kill productively infected CD4+ T cells and thus limit the spread of progeny virus. Recent innovations in antibody engineering have resulted in novel immunotherapeutics such as bispecific dual-affinity re-targeting (DART) molecules and other bi- and trispecific antibody designs that can recognize HIV-1 Env and recruit cytotoxic effector cells to kill CD4+ T cells latently infected with HIV‑1. Here, we review these immunotherapies, which are designed with the goal of curing HIV-1 infection. PMID:27725635

  8. Optomechanical effects of two-level systems in a back-action evading measurement of micro-mechanical motion

    Science.gov (United States)

    Suh, J.; Weinstein, A. J.; Schwab, K. C.

    2013-07-01

    We show that the two-level systems (TLS) in lithographic superconducting circuits act as a power-dependent dielectric leading to non-linear responses in a parametrically coupled electromechanical system. Driven TLS shift the microwave resonance frequency and modulate the mechanical resonance through the optical spring effect. By pumping with two tones in a back-action evading measurement, these effects produce a mechanical parametric instability which limits single quadrature imprecision to 1.4 xzp. The microwave resonator noise is also consistent to a TLS-noise model. These observations suggest design strategies for minimizing TLS effects to improve ground-state cooling and quantum non-demolition measurements of motion.

  9. Enhanced antibody-dependent cellular phagocytosis by chimeric monoclonal antibodies with tandemly repeated Fc domains.

    Science.gov (United States)

    Nagashima, Hiroaki; Ootsubo, Michiko; Fukazawa, Mizuki; Motoi, Sotaro; Konakahara, Shu; Masuho, Yasuhiko

    2011-04-01

    We previously reported that chimeric monoclonal antibodies (mAbs) with tandemly repeated Fc domains, which were developed by introducing tandem repeats of Fc domains downstream of 2 Fab domains, augmented binding avidities for all Fcγ receptors, resulting in enhanced antibody (Ab)-dependent cellular cytotoxicity. Here we investigated regarding Ab-dependent cellular phagocytosis (ADCP) mediated by these chimeric mAbs, which is considered one of the most important mechanisms that kills tumor cells, using two-color flow cytometric methods. ADCP mediated by T3-Ab, a chimeric mAb with 3 tandemly repeated Fc domains, was 5 times more potent than that by native anti-CD20 M-Ab (M-Ab hereafter). Furthermore, T3-Ab-mediated ADCP was resistant to competitive inhibition by intravenous Ig (IVIG), although M-Ab-mediated ADCP decreased in the presence of IVIG. An Fcγ receptor-blocking study demonstrated that T3-Ab mediated ADCP via both FcγRIA and FcγRIIA, whereas M-Ab mediated ADCP exclusively via FcγRIA. These results suggest that chimeric mAbs with tandemly repeated Fc domains enhance ADCP as well as ADCC, and that Fc multimerization may significantly enhance the efficacy of therapeutic Abs. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. Historically aggressive types of follicular cell-derived thyroid cancer often have radioactive avid distant metastases: a study of 314 patients with distant metastases at a single institution

    Energy Technology Data Exchange (ETDEWEB)

    Tala, H.P.; Rondeau, G.; Fagin, J.A.; Tuttle, R.M. [Endocrinology Division, Department of Medicine, Nuclear Medicine Division, Memorial Sloan Kettering Cancer Center, New-York (United States); Ghossein, R.A. [Pathology Department, Nuclear Medecine Division, Memorial Sloan Kettering Cancer Center, New-York (United States); Grewal, R.K.; Larson, S.M. [Radiology Department, Nuclear Medicine Division, Memorial Sloan Kettering Cancer Center, New-York (United States)

    2012-07-01

    Radioactive iodine (RAI) remains one of the primary treatment options for metastatic, follicular cell derived thyroid cancers. The aim of this study was to determine the likelihood that metastatic lesions arising from one of the aggressive thyroid cancer histologies [tall cell variant of papillary thyroid carcinoma (TCV-PTC), poorly differentiated thyroid carcinoma (PDTC) and Hurthle cell carcinoma (HCC)] would demonstrate sufficient RAI avidity for visualization on RAI scanning and therefore could potentially benefit from RAI therapy. The study shows that in patients selected for RAI scanning or therapy at our center, RAI avid lesions can be identified in more than two thirds of the patients with distant metastases arising in the setting of C-PTC, WD-FTC, FV-PTC, TCV-PTC, or PDTC primary tumors. While RAI avidity on a post-therapy scan does not always correlate with clinically significant tumor killing activity, it is likely that some of these patients with RAI avid metastatic disease did obtain a clinical benefit

  11. Usefulness of Toxoplasma gondii recombinant antigens (GRA1, GRA7 and SAG1) in an immunoglobulin G avidity test for the serodiagnosis of toxoplasmosis

    DEFF Research Database (Denmark)

    Pietkiewicz, H; Hiszczyńska-Sawicka, E; Kur, J

    2007-01-01

    The precise diagnosis of an acute and recent Toxoplasma infection in pregnant women and the newborn child is important before treatment. This study describes a new Toxoplasma gondii IgG avidity test based on a combination of recombinant GRA1, GRA7 and SAG1 antigens and shows that this test...

  12. Dual Testing Algorithm of BED-CEIA and AxSYM Avidity Index Assays Performs Best in Identifying Recent HIV Infection in a Sample of Rwandan Sex Workers

    NARCIS (Netherlands)

    Braunstein, S.L.; Nash, D.; Kim, A.A.; Ford, K.; Mwambarangwe, L.; Ingabire, C.M.; Vyankandondera, J.; van de Wijgert, J.H.H.M.

    2011-01-01

    To assess the performance of BED-CEIA (BED) and AxSYM Avidity Index (Ax-AI) assays in estimating HIV incidence among female sex workers (FSW) in Kigali, Rwanda. Eight hundred FSW of unknown HIV status were HIV tested; HIV-positive women had BED and Ax-AI testing at baseline and ≥12 months later to

  13. The necrosis-avid small molecule HQ4-DTPA as a multimodal imaging agent for monitoring radiation therapy-induced tumor cell death

    NARCIS (Netherlands)

    M.A. Stammes (Marieke A.); Maeda, A. (Azusa); Bu, J. (Jiachuan); Scolard, D.A. (Deborah A.); Kulbatski, I. (Iris); Medeiros, P.J. (Philip J.); Sinisi, R. (Riccardo); Dubikovskaya, E.A. (Elena A.); T.J.A. Snoeks (thomas); E.R. van Beek (Ermond); A. Chan (Albert); C.W.G.M. Löwik (Clemens); DaCosta, R.S. (Ralph S.)

    2016-01-01

    textabstractPurpose: Most effective antitumor therapies induce tumor cell death. Non-invasive, rapid and accurate quantitative imaging of cell death is essential for monitoring early response to antitumor therapies. To facilitate this, we previously developed a biocompatible necrosis-avid

  14. The kinetics of antibody binding to Plasmodium falciparum VAR2CSA PfEMP1 antigen and modelling of PfEMP1 antigen packing on the membrane knobs

    DEFF Research Database (Denmark)

    Joergensen, Lars M; Salanti, Ali; Dobrilovic, Tina

    2010-01-01

    on the parasitized erythrocyte membrane influences antibody association with, and dissociation from, its antigenic target. METHODS: A Quartz Crystal Microbalance biosensor was used to measure the association and dissociation kinetics of VAR2CSA PfEMP1 binding to human monoclonal antibodies. Immuno...... molecules. CONCLUSIONS: High avidity is required to achieve the strongest binding to VAR2CSA PfEMP1, but the structures that display PfEMP1 also tend to inhibit cross-linking between PfEMP1 antigens, by holding many binding epitopes at distances beyond the 15-18nm sweep radius of an antibody. The large size...

  15. [The end of food: dietary supplementation and diet among avid members of workout and fitness centers in Rio de Janeiro].

    Science.gov (United States)

    Sabino, César; Luz, Madel T; Carvalho, Maria Cláudia

    2010-06-01

    The article addresses the particular diet of a group of avid members of workout and fitness centers in Rio de Janeiro. It shows how diet is related to keeping in shape and to the prevailing type of sociability. Using direct and participatory ethnographic observation and open interviews, research was conducted at 12 fitness clubs on the North and South sides of Rio for three years. For the group under study, eating is about relying on a system of knowledge related to the science of nutrition for the benefit of managing one's physical shape and athletic performance. This movement produces the notion of food as a powerful chemical artifice that enhances the aesthetics of the body.

  16. HIV Incidence Estimates Using the Limiting Antigen Avidity EIA Assay at Testing Sites in Kiev City, Ukraine: 2013-2014.

    Science.gov (United States)

    Simmons, Ruth; Malyuta, Ruslan; Chentsova, Nelli; Karnets, Iryna; Murphy, Gary; Medoeva, Antonia; Kruglov, Yuri; Yurchenko, Alexander; Copas, Andrew; Porter, Kholoud

    2016-01-01

    To estimate HIV incidence and highlight the characteristics of persons at greatest risk of HIV in the Ukraine capital, Kiev. Residual samples from newly-diagnosed persons attending the Kiev City AIDS Centre were tested for evidence of recent HIV infection using an avidity assay. Questions on possible risk factors for HIV acquisition and testing history were introduced. All persons (≥16yrs) presenting for an HIV test April'13-March'14 were included. Rates per 100,000 population were calculated using region-specific denominators. During the study period 6370 individuals tested for HIV. Of the 467 individuals newly-diagnosed with HIV, 21 had insufficient samples for LAg testing. Of the remaining 446, 39 (8.7%) were classified as recent with an avidity index HIV infections. The only independent predictor for a recent infection was probable route of exposure, with MSM more likely to present with a recent infection compared with heterosexual contact [Odds Ratio 8.86; 95%CI 2.65-29.60]. We estimated HIV incidence at 21.5 per 100,000 population, corresponding to 466 new infections. Using population estimates for MSM and PWID, incidence was estimated to be between 2289.6 and 6868.7/100,000 MSM, and 350.4 for PWID. A high proportion of persons newly-infected remain undiagnosed, with MSM disproportionally affected with one in four newly-HIV-diagnosed and one in three recently-HIV-infected. Our findings should be used for targeted public health interventions and health promotion.

  17. HIV Incidence Estimates Using the Limiting Antigen Avidity EIA Assay at Testing Sites in Kiev City, Ukraine: 2013-2014.

    Directory of Open Access Journals (Sweden)

    Ruth Simmons

    Full Text Available To estimate HIV incidence and highlight the characteristics of persons at greatest risk of HIV in the Ukraine capital, Kiev.Residual samples from newly-diagnosed persons attending the Kiev City AIDS Centre were tested for evidence of recent HIV infection using an avidity assay. Questions on possible risk factors for HIV acquisition and testing history were introduced. All persons (≥16yrs presenting for an HIV test April'13-March'14 were included. Rates per 100,000 population were calculated using region-specific denominators.During the study period 6370 individuals tested for HIV. Of the 467 individuals newly-diagnosed with HIV, 21 had insufficient samples for LAg testing. Of the remaining 446, 39 (8.7% were classified as recent with an avidity index <1.5ODn, 10 were reclassified as long-standing as their viral load was <1000 copies/mL, resulting in 29 (6.5% recent HIV infections. The only independent predictor for a recent infection was probable route of exposure, with MSM more likely to present with a recent infection compared with heterosexual contact [Odds Ratio 8.86; 95%CI 2.65-29.60]. We estimated HIV incidence at 21.5 per 100,000 population, corresponding to 466 new infections. Using population estimates for MSM and PWID, incidence was estimated to be between 2289.6 and 6868.7/100,000 MSM, and 350.4 for PWID.A high proportion of persons newly-infected remain undiagnosed, with MSM disproportionally affected with one in four newly-HIV-diagnosed and one in three recently-HIV-infected. Our findings should be used for targeted public health interventions and health promotion.

  18. Chimeric PD-1:28 Receptor Upgrades Low-Avidity T cells and Restores Effector Function of Tumor-Infiltrating Lymphocytes for Adoptive Cell Therapy.

    Science.gov (United States)

    Schlenker, Ramona; Olguín-Contreras, Luis Felipe; Leisegang, Matthias; Schnappinger, Julia; Disovic, Anja; Rühland, Svenja; Nelson, Peter J; Leonhardt, Heinrich; Harz, Hartmann; Wilde, Susanne; Schendel, Dolores J; Uckert, Wolfgang; Willimsky, Gerald; Noessner, Elfriede

    2017-07-01

    Inherent intermediate- to low-affinity T-cell receptors (TCR) that develop during the natural course of immune responses may not allow sufficient activation for tumor elimination, making the majority of T cells suboptimal for adoptive T-cell therapy (ATT). TCR affinity enhancement has been implemented to provide stronger T-cell activity but carries the risk of creating undesired cross-reactivity leading to potential serious adverse effects in clinical application. We demonstrate here that engineering of low-avidity T cells recognizing a naturally processed and presented tumor-associated antigen with a chimeric PD-1:28 receptor increases effector function to levels seen with high-avidity T cells of identical specificity. Upgrading the function of low-avidity T cells without changing the TCR affinity will allow a large arsenal of low-avidity T cells previously thought to be therapeutically inefficient to be considered for ATT. PD-1:28 engineering reinstated Th1 function in tumor-infiltrating lymphocytes that had been functionally disabled in the human renal cell carcinoma environment without unleashing undesired Th2 cytokines or IL10. Involved mechanisms may be correlated to restoration of ERK and AKT signaling pathways. In mouse tumor models of ATT, PD-1:28 engineering enabled low-avidity T cells to proliferate stronger and prevented PD-L1 upregulation and Th2 polarization in the tumor milieu. Engineered T cells combined with checkpoint blockade secreted significantly more IFNγ compared with T cells without PD-1:28, suggesting a beneficial combination with checkpoint blockade therapy or other therapeutic strategies. Altogether, the supportive effects of PD-1:28 engineering on T-cell function make it an attractive tool for ATT. Cancer Res; 77(13); 3577-90. ©2017 AACR. ©2017 American Association for Cancer Research.

  19. RBC Antibody Screen

    Science.gov (United States)

    ... products and services. Advertising & Sponsorship: Policy | Opportunities RBC Antibody Screen Share this page: Was this page helpful? ... Indirect Coombs Test; Indirect Anti-human Globulin Test; Antibody Screen Formal name: Red Blood Cell Antibody Screen ...

  20. Antibody maturation and viral diversification in HIV-infected women.

    Directory of Open Access Journals (Sweden)

    Maria M James

    Full Text Available INTRODUCTION: The Post-exposure Prophylaxis in Infants (PEPI-Malawi trial evaluated infant antiretroviral regimens for prevention of post-natal HIV transmission. A multi-assay algorithm (MAA that includes the BED capture immunoassay, an avidity assay, CD4 cell count, and viral load was used to identify women who were vs. were not recently infected at the time of enrollment (MAA recent, N = 73; MAA non-recent, N = 2,488; a subset of the women in the MAA non-recent group known to have been HIV infected for at least 2 years before enrollment (known non-recent, N = 54. Antibody maturation and viral diversification were examined in these women. METHODS: Samples collected at enrollment (N = 2,561 and 12-24 months later (N = 1,306 were available for serologic analysis using the BED and avidity assays. A subset of those samples was used for analysis of viral diversity, which was performed using a high resolution melting (HRM diversity assay. Viral diversity analysis was performed using all available samples from women in the MAA recent group (61 enrollment samples, 38 follow-up samples and the known non-recent group (43 enrollment samples, 22 follow-up samples. Diversity data from PEPI-Malawi were also compared to similar data from 169 adults in the United States (US with known recent infection (N = 102 and known non-recent infection (N = 67. RESULTS: In PEPI-Malawi, results from the BED and avidity assays increased over time in the MAA recent group, but did not change significantly in the MAA non-recent group. At enrollment, HIV diversity was lower in the MAA recent group than in the known non-recent group. HRM diversity assay results from women in PEPI-Malawi were similar to those from adults in the US with known duration of HIV infection. CONCLUSIONS: Antibody maturation and HIV diversification patterns in African women provide additional support for use of the MAA to identify populations with recent HIV infection.

  1. Muusikamaailm : Festivalil Schwetzingenis. Ellingtoni sajandi tähistamine. Linz saab uue ooperimaja. Isaac Stern viiulita Saksamaal. Muusikapäevad Luksemburgis / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    1999-01-01

    30. apr.-7. juunini toimuvast muusikafestivalist Schwetzingenis. D. Ellingtoni 100. sünniaastapäeva tähistamisest maailmas. Valmis Linzi uue ooperimaja planeering. I. Stern juhatas kümnepäevast seminari Kölni Kõrgema Muusikakooli juures. Rahvusvahelise Nüüdismuusika Ühingu (ISCM) iga-aastased maailma muusikapäevad toimuvad 2000. aastal Luksemburgis

  2. Fc receptor inside-out signaling and possible impact on antibody therapy.

    Science.gov (United States)

    Brandsma, Arianne M; Jacobino, Shamir R; Meyer, Saskia; ten Broeke, Toine; Leusen, Jeanette H W

    2015-11-01

    Fc receptors (FcR) are expressed on immune cells and bind to the Fc tail of antibodies. This interaction is essential for FcR-mediated signaling and triggering of cellular effector functions. FcR activation is tightly regulated to prevent immune responses by non-antigen bound antibodies or in the absence of 'danger signals'. FcR activity may be modulated at the plasma membrane via cross-talk with integrins. In addition, cytokines at the site of infection/inflammation can increase FcR avidity, a process referred to as inside-out signaling. This regulatory mechanism has been described for FcγRI (CD64), FcγRIIa (CD32a), and FcαRI (CD89) and is also well-known for integrins. Key cellular events during inside-out signaling are (de)phosphorylation, clustering, cytoskeleton rearrangements, and conformational changes. The latter can be studied with antibodies that specifically recognize epitopes exposed by the active (high affinity) or inactive (low affinity) state of the FcR. These antibodies are important tools to investigate the role of FcR activation in disease settings. Research on FcR has gained momentum with the rise of monoclonal antibodies (mAb) entering the clinic for the treatment of cancer and other diseases. The clinical outcome of mAb therapy may be improved by increasing FcR avidity by cytokine stimulation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-07

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

  4. Small RNA-mediated Cry toxin silencing allows Bacillus thuringiensis to evade Caenorhabditis elegans avoidance behavioral defenses

    Science.gov (United States)

    Peng, Donghai; Luo, Xiaoxia; Zhang, Ni; Guo, Suxia; Zheng, Jinshui; Chen, Ling

    2018-01-01

    Abstract Pathogen avoidance behavior protects animal hosts against microbial pathogens. Pathogens have evolved specific strategies during coevolution in response to such host defenses. However, these strategies for combatting host avoidance behavioral defenses remain poorly understood. Here, we used Caenorhabditis elegans and its bacterial pathogen Bacillus thuringiensis as a model and determined that small RNA (sRNA)-mediated Cry toxin silencing allowed pathogens to evade host avoidance behavioral defenses. The B. thuringiensis strain YBT-1518, which encodes three nematicidal cry genes, is highly toxic to C. elegans. However, the expression of the most potent toxin, Cry5Ba, was silenced in this strain when YBT-1518 was outside the host. Cry5Ba silencing was due to the sRNA BtsR1, which bound to the RBS site of the cry5Ba transcript via direct base pairing and inhibited Cry5Ba expression. Upon ingestion by C. elegans, Cry5Ba was expressed in vivo by strain YBT-1518. Cry5Ba silencing may allow B. thuringiensis to avoid nematode behavioral defenses and then express toxins once ingested to kill the host and gain a survival advantage. Our work describes a novel model of sRNA-mediated regulation to aid pathogens in combating host avoidance behavioral defenses. PMID:29069426

  5. The West Nile virus assembly process evades the conserved antiviral mechanism of the interferon-induced MxA protein

    Energy Technology Data Exchange (ETDEWEB)

    Hoenen, Antje [School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane (Australia); Gillespie, Leah [Department of Microbiology, La Trobe University, Melbourne (Australia); Department of Microbiology and Immunology, University of Melbourne, Melbourne (Australia); Morgan, Garry; Heide, Peter van der [Institute for Molecular Bioscience, University of Queensland, Brisbane (Australia); Khromykh, Alexander [School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane (Australia); Australian Infectious Diseases Research Centre, University of Queensland, Brisbane (Australia); Mackenzie, Jason, E-mail: jason.mackenzie@unimelb.edu.au [Department of Microbiology, La Trobe University, Melbourne (Australia); Department of Microbiology and Immunology, University of Melbourne, Melbourne (Australia)

    2014-01-05

    Flaviviruses have evolved means to evade host innate immune responses. Recent evidence suggests this is due to prevention of interferon production and signaling in flavivirus-infected cells. Here we show that the interferon-induced MxA protein can sequester the West Nile virus strain Kunjin virus (WNV{sub KUN}) capsid protein in cytoplasmic tubular structures in an expression-replication system. This sequestering resulted in reduced titers of secreted WNV{sub KUN} particles. We show by electron microscopy, tomography and 3D modeling that these cytoplasmic tubular structures form organized bundles. Additionally we show that recombinant ER-targeted MxA can restrict production of infectious WNV{sub KUN} under conditions of virus infection. Our results indicate a co-ordinated and compartmentalized WNV{sub KUN} assembly process may prevent recognition of viral components by MxA, particularly the capsid protein. This recognition can be exploited if MxA is targeted to intracellular sites of WNV{sub KUN} assembly. This results in further understanding of the mechanisms of flavivirus evasion from the immune system. - Highlights: • We show that the ISG MxA can recognize the West Nile virus capsid protein. • Interaction between WNV C protein and MxA induces cytoplasmic fibrils. • MxA can be retargeted to the ER to restrict WNV particle release. • WNV assembly process is a strategy to avoid MxA recognition.

  6. Upregulated Op18/stathmin activity causes chromosomal instability through a mechanism that evades the spindle assembly checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Holmfeldt, Per; Sellin, Mikael E. [Department of Molecular Biology, Umea University, SE-901 87 Umea (Sweden); Gullberg, Martin, E-mail: Martin.Gullberg@molbiol.umu.se [Department of Molecular Biology, Umea University, SE-901 87 Umea (Sweden)

    2010-07-15

    Op18/stathmin (Op18) is a microtubule-destabilizing protein that is phosphorylation-inactivated during mitosis and its normal function is to govern tubulin subunit partitioning during interphase. Human tumors frequently overexpress Op18 and a tumor-associated Q18{yields}E mutation has been identified that confers hyperactivity, destabilizes spindle microtubules, and causes mitotic aberrancies, polyploidization, and chromosome loss in K562 leukemia cells. Here we determined whether wild-type and mutant Op18 have the potential to cause chromosomal instability by some means other than interference with spindle assembly, and thereby bypassing the spindle assembly checkpoint. Our approach was based on Op18 derivatives with distinct temporal order of activity during mitosis, conferred either by differential phosphorylation inactivation or by anaphase-specific degradation through fusion with the destruction box of cyclin B1. We present evidence that excessive Op18 activity generates chromosomal instability through interference occurring subsequent to the metaphase-to-anaphase transition, which reduces the fidelity of chromosome segregation to spindle poles during anaphase. Similar to uncorrected merotelic attachment, this mechanism evades detection by the spindle assembly checkpoint and thus provides an additional route to chromosomal instability.

  7. Cooperative option of pursuit game with two pursuers and one evader. A strong stability of division variety

    Directory of Open Access Journals (Sweden)

    Viktor D. Shiryayev

    2017-06-01

    Full Text Available Introduction: The article deals with a simple differential game on the plane of pursuit with two consistently active players and one evader E; the game is considered in the form of the characteristic function. Materials and Methods: The geometric constructions and methods are used for solving the problem. The security zone of the escapee is bounded by the Apollonius circle, the pursuit team uses a strategy of parallel approach. Results: A method of finding the optimal players strategies and the optimal players’ trajectory is proposed. The way of forming the characteristic function is provided. All the variety of division is considered as a solution. However, the use of the results of cooperative theory of differential games is impossible without solving the problems associated with the specifics of differential equations of motion. Foremost, it is the problem of dynamic stability of optimality principles. The article introduces an auxiliary function of making the redistribution of winnings in time, keeping his total winnings throughout the game. The dynamic stability of the cooperative solution is determined with the help of this function. Strong dynamic stability of the entire set of solutions is shown. Discussion and Conclusions: The obtained results are consistent with similar research of other authors. Further research in this field can be used in the development of methods for “regularization” of optimality principles, for which the condition of dynamic stability is always fulfilled.

  8. Pasteurella pneumotropica evades the human complement system by acquisition of the complement regulators factor H and C4BP.

    Directory of Open Access Journals (Sweden)

    Alfredo Sahagún-Ruiz

    Full Text Available Pasteurella pneumotropica is an opportunist Gram negative bacterium responsible for rodent pasteurellosis that affects upper respiratory, reproductive and digestive tracts of mammals. In animal care facilities the presence of P. pneumotropica causes severe to lethal infection in immunodeficient mice, being also a potential source for human contamination. Indeed, occupational exposure is one of the main causes of human infection by P. pneumotropica. The clinical presentation of the disease includes subcutaneous abscesses, respiratory tract colonization and systemic infections. Given the ability of P. pneumotropica to fully disseminate in the organism, it is quite relevant to study the role of the complement system to control the infection as well as the possible evasion mechanisms involved in bacterial survival. Here, we show for the first time that P. pneumotropica is able to survive the bactericidal activity of the human complement system. We observed that host regulatory complement C4BP and Factor H bind to the surface of P. pneumotropica, controlling the activation pathways regulating the formation and maintenance of C3-convertases. These results show that P. pneumotropica has evolved mechanisms to evade the human complement system that may increase the efficiency by which this pathogen is able to gain access to and colonize inner tissues where it may cause severe infections.

  9. High-Avidity Monoclonal Antibodies against the Human Scavenger Class B Type I Receptor Efficiently Block Hepatitis C Virus Infection in the Presence of High-Density Lipoprotein▿

    OpenAIRE

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

    2007-01-01

    The human scavenger class B type 1 receptor (SR-B1/Cla1) was identified as a putative receptor for hepatitis C virus (HCV) because it binds to soluble recombinant HCV envelope glycoprotein E2 (sE2). High-density lipoprotein (HDL), a natural SR-B1 ligand, was shown to increase the in vitro infectivity of retroviral pseudoparticles bearing HCV envelope glycoproteins and of cell culture-derived HCV (HCVcc), suggesting that SR-B1 promotes viral entry in an HDL-dependent manner. To determine wheth...

  10. Duration of (18)F-FDG avidity in lymph nodes after pandemic H1N1v and seasonal influenza vaccination

    DEFF Research Database (Denmark)

    Thomassen, Anders; Lerberg Nielsen, Anne; Gerke, Oke

    2011-01-01

    PURPOSE: The aim of our study was to investigate the occurrence of fluorodeoxyglucose (FDG) avidity in draining axillary lymph nodes after vaccination against influenza (H1N1v pandemic and seasonal) and to determine the period of increased FDG uptake. METHODS: During December 2009, patients...... axillary. If more vaccinations had been given, only the latest vaccination was evaluated in each deltoid region. RESULTS: Of all patients who underwent PET/CT scans during December 2009, 26% had been vaccinated with at least one influenza vaccination in the deltoid region. A total of 92 'draining' and 60...... lymph nodes. CONCLUSION: Influenza vaccination may lead to FDG-avid draining lymph nodes beyond 1 month....

  11. Anti-dog IgG secondary antibody successfully detects IgG in a variety of aquatic mammals

    Science.gov (United States)

    Roehl, Katherine; Jankowski, Mark D.; Hofmeister, Erik K.

    2016-01-01

    Serological tests play an important role in the detection of wildlife diseases. However, while there are many commercial assays and reagents available for domestic species, there is a need to develop efficient serological assays for wildlife. In recent years, marine mammals have represented a wildlife group with emerging infectious diseases, such as influenza, brucellosis, and leptospirosis. However, with the exception of disease-agent-specific assays or functional assays, few reports describe the use of antibody detection assays in marine mammals. In an indirect enzyme-linked immunoassay (EIA) or an immunofluorescence assay, antibody is detected using an antitarget species secondary conjugated antibody. The sensitivity of the assay depends on the avidity of the binding reaction between the bound antibody and the detection antibody. A commercial polyclonal antidog IgG conjugated antibody was tested in an EIA for its ability to sensitively detect the IgG of seven marine mammals including sea otter (Enhydra lutris), polar bear (Ursus maritimus), grey seal (Halichoerus grypus), harbor seal (Phoca vitulina), northern elephant seal (Mirounga angustirostris), California sea lion (Zalophus californianus), Pacific walrus (Odobenus rosmarus) and one freshwater mammal: Asian small-clawed otter (Aonyx cinerea). With the exception of Asian small-clawed sea otters, the detection of IgG in these marine mammals either exceeded or was nearly equal to detection of dog IgG. The use of the tested commercial antidog IgG antibody may be a valid approach to the detection of antibody response to disease in sea mammals.

  12. Antibodies and Selection of Monoclonal Antibodies.

    Science.gov (United States)

    Hanack, Katja; Messerschmidt, Katrin; Listek, Martin

    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.

  13. Lectin-functionalized poly(glycidyl methacrylate)-block-poly(vinyldimethyl azlactone) surface supports for high avidity microbial capture

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ryan R [ORNL; Hinestrosa Salazar, Juan P [ORNL; Shubert, Katherine R [ORNL; Morrell, Jennifer L. [University of Tennessee, Knoxville (UTK); Pelletier, Dale A [ORNL; Messman, Jamie M [ORNL; Kilbey, II, S Michael [ORNL; Lokitz, Bradley S [ORNL; Retterer, Scott T [ORNL

    2013-01-01

    Microbial exopolysaccharides (EPS) play a critical and dynamic role in shaping the interactions between microbial community members and their local environment. The capture of targeted microbes using surface immobilized lectins that recognize specific extracellular oligosaccharide moieties offers a non-destructive method for functional characterization based on EPS content. In this report, we evaluate the use of the block co-polymer, poly(glycidyl methacrylate)-block-4,4-dimethyl-2-vinylazlactone (PGMA-b-PVDMA), as a surface support for lectin-specific microbial capture. Arrays of circular polymer supports ten micron in diameter were generated on silicon substrates to provide discrete, covalent coupling sites for Triticum vulgare and Lens culinaris lectins. These supports promoted microbe adhesion and colony formation in a lectin-specific manner. Silicon posts with similar topography containing only physisorbed lectins showed significantly less activity. These results demonstrate that micropatterned PGMA-b-PVDMA supports provide a unique platform for microbial capture and screening based on EPS content by combining high avidity lectin surfaces with three-dimensional topography.

  14. Metastatic Follicular Thyroid Carcinoma Secreting Thyroid Hormone and Radioiodine Avid without Stimulation: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Syed A. Abid

    2014-01-01

    Full Text Available Introduction. This is an extremely rare case of a patient with metastatic follicular thyroid cancer who continued to produce thyroid hormone and was iodine scan positive without stimulation after thyroidectomy and radioiodine (I-131 therapy. Patient Findings. A 76-year-old Caucasian male was diagnosed with metastatic follicular thyroid carcinoma on lung nodule biopsy. Total thyroidectomy was performed and he was ablated with 160 mCi of I-131 after recombinant human thyrotropin (rhTSH stimulation. Whole body scan (WBS after treatment showed uptake in bilateral lungs, right sacrum, and pelvis. The thyroglobulin decreased from 2,063 to 965 four months after treatment but rapidly increased to 2,506 eleven months after I-131. Thyroid stimulating hormone (TSH remained suppressed and free T4 remained elevated after I-131 therapy without thyroid hormone supplementation. He was treated with an additional 209 mCi with WBS findings positive in lung and pelvis. Despite I-131, new metastatic lesions were noted in the left thyroid bed and large destructive lesion to the first cervical vertebrae four months after the second I-131 dose. Conclusions. This case is exceptional because of its rarity and also due to the dissociation between tumor differentiation and aggressiveness. The metastatic lesions continued to secrete thyroid hormone and remained radioiodine avid with rapid progression after I-131 therapy.

  15. HIV incidence in the Estonian population in 2013 determined using the HIV-1 limiting antigen avidity assay.

    Science.gov (United States)

    Soodla, P; Simmons, R; Huik, K; Pauskar, M; Jõgeda, E-L; Rajasaar, H; Kallaste, E; Maimets, M; Avi, R; Murphy, G; Porter, K; Lutsar, I

    2017-08-01

    Estonia has one the highest number of new HIV diagnoses in the European Union, mainly among injecting drug users and heterosexuals. Little is known of HIV incidence, which is crucial for limiting the epidemic. Using a recent HIV infection testing algorithm (RITA) assay, we aimed to estimate HIV incidence in 2013. All individuals aged ≥18 years newly-diagnosed with HIV in Estonia January- December 2013, except blood donors and those undergoing antenatal screening, were included. Demographic and clinical data were obtained from the Estonian Health Board and the Estonian HIV-positive patient database. Serum samples were tested for recent infection using the LAg-avidity EIA assay. HIV incidence was estimated based on previously published methods. Of 69,115 tested subjects, 286 (0.41%) were newly-diagnosed with HIV with median age of 33 years (IQR: 28-42) and 65% male. Self-reported routes of HIV transmission were mostly heterosexual contact (n = 157, 53%) and injecting drug use (n = 62, 21%); 64 (22%) were with unknown risk group. Eighty two (36%) were assigned recent, resulting in estimated HIV incidence of 0.06%, corresponding to 642 new infections in 2013 among the non-screened population. Incidence was highest (1.48%) among people who inject drugs. These high HIV incidence estimates in Estonia call for urgent action of renewed targeted public health promotion and HIV testing campaigns. © 2017 British HIV Association.

  16. Potential Pitfall in the Assessment of Lung Cancer with FDG-PET/CT: Talc Pleurodesis Causes Intrathoracic Nodal FDG Avidity

    Directory of Open Access Journals (Sweden)

    Yingbing Wang

    2013-01-01

    Full Text Available Objective. Talc pleurodesis is a common procedure performed to treat complications related to lung cancer. The purpose of our study was to characterize any thoracic nodal findings on FDG PET/CT associated with prior talc pleurodesis. Materials and Methods. The electronic medical record identified 44 patients who underwent PET/CT between January 2006 and December 2010 and had a history of talc pleurodesis. For each exam, we evaluated the distribution pattern, size, and attenuation of intrathoracic lymph nodes and the associated standardized uptake value. Results. High-attenuation intrathoracic lymph nodes were noted in 11 patients (25%, and all had corresponding increased FDG uptake (range 2–9 mm. Involved nodal groups were anterior peridiaphragmatic (100%, paracardiac (45%, internal mammary (25%, and peri-IVC (18% nodal stations. Seven of the 11 patients (63% had involvement of multiple lymph nodal groups. Mean longitudinal PET/CT and standalone CT followups of 15±11 months showed persistence of both high-attenuation and increased uptake at these sites, without increase in nodal size suggesting metastatic disease involvement. Conclusions. FDG avid, high-attenuation lymph nodes along the lymphatic drainage pathway for parietal pleura are a relatively common finding following talc pleurodesis and should not be mistaken for nodal metastases during the evaluation of patients with history of lung cancer.

  17. Use of IgG avidity ELISA to differentiate acute from persistent infection with Salmonella Dublin in cattle

    DEFF Research Database (Denmark)

    Hansen, K.R.; Nielsen, L.R.; Lind, Peter

    2006-01-01

    Aims: To investigate whether an immunoglobulin (Ig)G avidity ELISA can be used to differentiate between acute and persistent infection with Salmonella (S.) Dublin in cattle. To determine whether the IgG isotype, IgG(1) and IgG(2) responses in acute and persistent infections differ. Methods...... of persistent infection with S. Dublin in cattle, it can be concluded that the IgG-AI can aid in differentiating between acute and long-term infection on herd level. However, for the test to be useful as an alternative tool to repeated sampling over time for detection of persistently infected carriers during...... control strategies in cattle herds, the test needs to be optimized and studied further in a larger sample of well-characterized infections in cattle. The affinity of IgG(2) is higher than IgG(1) early in the S. Dublin infection. There appears to be no difference in the IgG(2)-AI between the acute...

  18. Necrosis avid near infrared fluorescent cyanines for imaging cell death and their use to monitor therapeutic efficacy in mouse tumor models.

    Science.gov (United States)

    Xie, Bangwen; Stammes, Marieke A; van Driel, Pieter B A A; Cruz, Luis J; Knol-Blankevoort, Vicky T; Löwik, Martijn A M; Mezzanotte, Laura; Que, Ivo; Chan, Alan; van den Wijngaard, Jeroen P H M; Siebes, Maria; Gottschalk, Sven; Razansky, Daniel; Ntziachristos, Vasilis; Keereweer, Stijn; Horobin, Richard W; Hoehn, Mathias; Kaijzel, Eric L; van Beek, Ermond R; Snoeks, Thomas J A; Löwik, Clemens W G M

    2015-11-17

    Quantification of tumor necrosis in cancer patients is of diagnostic value as the amount of necrosis is correlated with disease prognosis and it could also be used to predict early efficacy of anti-cancer treatments. In the present study, we identified two near infrared fluorescent (NIRF) carboxylated cyanines, HQ5 and IRDye 800CW (800CW), which possess strong necrosis avidity. In vitro studies showed that both dyes selectively bind to cytoplasmic proteins of dead cells that have lost membrane integrity. Affinity for cytoplasmic proteins was confirmed using quantitative structure activity relations modeling. In vivo results, using NIRF and optoacoustic imaging, confirmed the necrosis avid properties of HQ5 and 800CW in a mouse 4T1 breast cancer tumor model of spontaneous necrosis. Finally, in a mouse EL4 lymphoma tumor model, already 24 h post chemotherapy, a significant increase in 800CW fluorescence intensity was observed in treated compared to untreated tumors. In conclusion, we show, for the first time, that the NIRF carboxylated cyanines HQ5 and 800CW possess strong necrosis avid properties in vitro and in vivo. When translated to the clinic, these dyes may be used for diagnostic or prognostic purposes and for monitoring in vivo tumor response early after the start of treatment.

  19. Uudised : Üheteistkümnendad trompetipäevad. Eesti Muusikanõukogus. Tüüri "Motus I" Londonis / Kadri Ruudi

    Index Scriptorium Estoniae

    Ruudi, Kadri

    2000-01-01

    4.-15. apr. toimuvad EMA XI trompetipäevad. 14.-19. märtsil viibis Eestis IMC asepresident F. Müller-Heuser, 22. märtsil toimus EMN juhatuse koosolek. 19. märtsil andis Londoni South Bank Centre'is kontserdi P. Carneiro, kes tõi Inglismaal esiettekandele ka E.-S. Tüüri teose "Motus I"

  20. Neisseria gonorrhoeae Evades Calprotectin-Mediated Nutritional Immunity and Survives Neutrophil Extracellular Traps by Production of TdfH.

    Science.gov (United States)

    Jean, Sophonie; Juneau, Richard A; Criss, Alison K; Cornelissen, Cynthia N

    2016-10-01

    Neisseria gonorrhoeae successfully overcomes host strategies to limit essential nutrients, termed nutritional immunity, by production of TonB-dependent transporters (TdTs)-outer membrane proteins that facilitate nutrient transport in an energy-dependent manner. Four gonococcal TdTs facilitate utilization of iron or iron chelates from host-derived proteins, including transferrin (TbpA), lactoferrin (LbpA), and hemoglobin (HpuB), in addition to xenosiderophores from other bacteria (FetA). The roles of the remaining four uncharacterized TdTs (TdfF, TdfG, TdfH, and TdfJ) remain elusive. Regulatory data demonstrating that production of gonococcal TdfH and TdfJ are unresponsive to or upregulated under iron-replete conditions led us to evaluate the role of these TdTs in the acquisition of nutrients other than iron. In this study, we found that production of gonococcal TdfH is both Zn and Zur repressed. We also found that TdfH confers resistance to calprotectin, an immune effector protein highly produced in neutrophils that has antimicrobial activity due to its ability to sequester Zn and Mn. We found that TdfH directly binds calprotectin, which enables gonococcal Zn accumulation in a TdfH-dependent manner and enhances bacterial survival after exposure to neutrophil extracellular traps (NETs). These studies highlight Zn sequestration by calprotectin as a key functional arm of NET-mediated killing of gonococci. We demonstrate for the first time that N. gonorrhoeae exploits this host strategy in a novel defense mechanism, in which TdfH production hijacks and directly utilizes the host protein calprotectin as a zinc source and thereby evades nutritional immunity. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  1. Rice OsFLS2-Mediated Perception of Bacterial Flagellins Is Evaded by Xanthomonas oryzae pvs. oryzae and oryzicola.

    Science.gov (United States)

    Wang, Shanzhi; Sun, Zhe; Wang, Huiqin; Liu, Lijuan; Lu, Fen; Yang, Jun; Zhang, Min; Zhang, Shiyong; Guo, Zejian; Bent, Andrew F; Sun, Wenxian

    2015-07-01

    Bacterial flagellins are often recognized by the receptor kinase FLAGELLIN SENSITIVE2 (FLS2) and activate MAMP-triggered immunity in dicotyledonous plants. However, the capacity of monocotyledonous rice to recognize flagellins of key rice pathogens and its biological relevance remain poorly understood. We demonstrate that ectopically expressed OsFLS2 in Arabidopsis senses the eliciting flg22 peptide and in vitro purified Acidovorax avenae (Aa) flagellin in an expression level-dependent manner, but does not recognize purified flagellins or derivative flg22(Xo) peptides of Xanthomonas oryzae pvs. oryzae (Xoo) and oryzicola (Xoc). Consistently, the flg22 peptide and purified Aa flagellin, but not Xoo/Xoc flagellins, induce various immune responses such as defense gene induction and MAPK activation in rice. Perception of flagellin by rice does induce strong resistance to Xoo infection, as shown after pre-treatment of rice leaves with Aa flagellin. OsFLS2 was found to differ from AtFLS2 in its perception specificities or sensitivities to different flg22 sequences. In addition, post-translational modification of Xoc flagellin was altered by deletion of glycosyltransferase-encoding rbfC, but this had little effect on Xoc motility and rpfC mutation did not detectably reduce Xoc virulence on rice. Deletion of flagellin-encoding fliC from Xoo/Xoc blocked swimming motility but also did not significantly alter Xoo/Xoc virulence. These results suggest that Xoo/Xoc carry flg22-region amino acid changes that allow motility while evading the ancient flagellin detection system in rice, which retains recognition capacity for other bacterial pathogens. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  2. Acetylcholine receptor antibody

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003576.htm Acetylcholine receptor antibody To use the sharing features on this page, please enable JavaScript. Acetylcholine receptor antibody is a protein found in the blood ...

  3. Antinuclear antibody panel

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003535.htm Antinuclear antibody panel To use the sharing features on this page, please enable JavaScript. The antinuclear antibody panel is a blood test that looks at ...

  4. Platelet antibodies blood test

    Science.gov (United States)

    This blood test shows if you have antibodies against platelets in your blood. Platelets are a part of the blood ... Chernecky CC, Berger BJ. Platelet antibody - blood. In: Chernecky ... caused by platelet destruction, hypersplenism, or hemodilution. ...

  5. Establishment of replacement International Standard 13/132 for human antibodies to Toxoplasma gondii.

    Science.gov (United States)

    Rijpkema, Sjoerd; Hockley, Jason; Rigsby, Peter; Guy, Edward C

    2016-09-01

    Sixteen laboratories carried out a collaborative study to validate 13/132 as a replacement International Standard (IS) for TOXM (3rd IS for anti-Toxoplasma Serum, Human, 1000 IU). 13/132 is a freeze dried preparation of pooled human plasma from six donors who experienced a recent Toxoplasma gondii infection. The potency of 13/132 was compared to TOXM and 01/600 (1st IS for anti-Toxoplasma IgG, Human, 20 IU). Samples were tested for IgA, IgG, IgG avidity and IgM in agglutination assays; enzyme linked immunosorbent assays (ELISA), enzyme linked fluorescent assays, immunoblots, immunofluorescence assays and the Sabin-Feldman dye test for Ig. 13/132 was strongly positive for Ig, IgA, IgG and IgM and the reproducibility was very good. 13/132 contains high levels of anti-Toxoplasma Ig, IgG and IgM and its potency falls between TOXM and 01/600. The avidity of IgG was found to be low, similar to the avidity of IgG from TOXM. 13/132 was established by the Expert Committee on Biological Standardization as the 4th IS for Antibodies, Human, to T. gondii with an assigned unitage of 160 IU per ampoule for Ig by dye test and 263 U per ampoule for IgG by ELISA. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Evading the Boomerang Effect

    DEFF Research Database (Denmark)

    Laursen, Keld; Moreira, Solon; Reichstein, Toke

    2017-01-01

    Technology licensing agreements potentially can create future appropriability problems. Drawing on the appropriability literature, we argue that the inclusion of a grant-back clause in technology licensing agreements is an attempt to balance the gains from and protection of the focal firms’ techn...

  7. Heavy chain only antibodies

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  8. Antibodies Against Melanin

    African Journals Online (AJOL)

    1973-01-06

    Jan 6, 1973 ... This study reports on unsuccessful attempts to produce antibodies against melanoprotein in rabbits. Available evidence suggests antibodies against melanocytes in the aetiology of vitiligo, but there is no convincing evidence for antibodies against melanin per se. It is suggested that the demonstration of ...

  9. Antiparasitic effects induced by polyclonal IgY antibodies anti-phospholipase A2 from Bothrops pauloensis venom.

    Science.gov (United States)

    Borges, Isabela Pacheco; Silva, Mariana Ferreira; Santiago, Fernanda Maria; de Faria, Lucas Silva; Júnior, Álvaro Ferreira; da Silva, Rafaela José; Costa, Mônica Soares; de Freitas, Vitor; Yoneyama, Kelly Aparecida Geraldo; Ferro, Eloísa Amália Vieira; Lopes, Daiana Silva; Rodrigues, Renata Santos; de Melo Rodrigues, Veridiana

    2018-01-31

    Activities of phospholipases (PLAs) have been linked to pathogenesis in various microorganisms, and implicated in cell invasion and so the interest in these enzymes as potential targets that could contribute to the control of parasite survival and proliferation. Chicken eggs immunized with BnSP-7, a Lys49 phospholipase A2 (PLA2) homologue from Bothrops pauloensis snake venom, represent an excellent source of polyclonal antibodies with potential inhibitory activity on parasite PLAs. Herein, we report the production, characterization and anti-parasitic effect of IgY antibodies from egg yolks of hens immunized with BnSP-7. Produced antibodies presented increasing avidity and affinity for antigenic toxin epitopes throughout immunization, attaining a plateau after 4weeks. Pooled egg yolks-purified anti-BnSP-7 IgY antibodies were able to specifically recognize different PLA2s from Bothrops pauloensis and Bothrops jararacussu venom. Antibodies also neutralized BnSP-7 cytotoxic activity in C2C12 cells. Also, the antibodies recognized targets in Leishmania (Leishmania) amazonensis and Toxoplasma gondii extracts by ELISA and immunofluorescence assays. Anti-BnSP-7 IgY antibodies were cytotoxic to T. gondii tachyzoite and L. (L.) amazonensis promastigotes, and were able to decrease proliferation of both parasites treated before infection. These data suggest that the anti-BnSP-7 IgY is an important tool for discovering new parasite targets and blocking parasitic effects. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Pentavalent single-domain antibodies reduce Campylobacter jejuni motility and colonization in chickens.

    Science.gov (United States)

    Riazi, Ali; Strong, Philippa C R; Coleman, Russell; Chen, Wangxue; Hirama, Tomoko; van Faassen, Henk; Henry, Matthew; Logan, Susan M; Szymanski, Christine M; Mackenzie, Roger; Ghahroudi, Mehdi Arbabi

    2013-01-01

    Campylobacter jejuni is the leading cause of bacterial foodborne illness in the world, with symptoms ranging from acute diarrhea to severe neurological disorders. Contaminated poultry meat is a major source of C. jejuni infection, and therefore, strategies to reduce this organism in poultry, are expected to reduce the incidence of Campylobacter-associated diseases. We have investigated whether oral administration of C. jejuni-specific single-domain antibodies would reduce bacterial colonization levels in chickens. Llama single-domain antibodies specific for C. jejuni were isolated from a phage display library generated from the heavy chain IgG variable domain repertoire of a llama immunized with C. jejuni flagella. Two flagella-specific single-domain antibodies were pentamerized to yield high avidity antibodies capable of multivalent binding to the target antigen. When administered orally to C. jejuni-infected two-day old chicks, the pentabodies significantly reduced C. jejuni colonization in the ceca. In vitro, the motility of the bacteria was also reduced in the presence of the flagella-specific pentabodies, suggesting the mechanism of action is through either direct interference with flagellar motility or antibody-mediated aggregation. Fluorescent microscopy and Western blot analyses revealed specific binding of the anti-flagella pentabodies to the C. jejuni flagellin.

  11. Pentavalent single-domain antibodies reduce Campylobacter jejuni motility and colonization in chickens.

    Directory of Open Access Journals (Sweden)

    Ali Riazi

    Full Text Available Campylobacter jejuni is the leading cause of bacterial foodborne illness in the world, with symptoms ranging from acute diarrhea to severe neurological disorders. Contaminated poultry meat is a major source of C. jejuni infection, and therefore, strategies to reduce this organism in poultry, are expected to reduce the incidence of Campylobacter-associated diseases. We have investigated whether oral administration of C. jejuni-specific single-domain antibodies would reduce bacterial colonization levels in chickens. Llama single-domain antibodies specific for C. jejuni were isolated from a phage display library generated from the heavy chain IgG variable domain repertoire of a llama immunized with C. jejuni flagella. Two flagella-specific single-domain antibodies were pentamerized to yield high avidity antibodies capable of multivalent binding to the target antigen. When administered orally to C. jejuni-infected two-day old chicks, the pentabodies significantly reduced C. jejuni colonization in the ceca. In vitro, the motility of the bacteria was also reduced in the presence of the flagella-specific pentabodies, suggesting the mechanism of action is through either direct interference with flagellar motility or antibody-mediated aggregation. Fluorescent microscopy and Western blot analyses revealed specific binding of the anti-flagella pentabodies to the C. jejuni flagellin.

  12. High Affinity Antibodies against Influenza Characterize the Plasmablast Response in SLE Patients After Vaccination.

    Science.gov (United States)

    Kaur, Kaval; Zheng, Nai-Ying; Smith, Kenneth; Huang, Min; Li, Lie; Pauli, Noel T; Henry Dunand, Carole J; Lee, Jane-Hwei; Morrissey, Michael; Wu, Yixuan; Joachims, Michelle L; Munroe, Melissa E; Lau, Denise; Qu, Xinyan; Krammer, Florian; Wrammert, Jens; Palese, Peter; Ahmed, Rafi; James, Judith A; Wilson, Patrick C

    2015-01-01

    Breakdown of B cell tolerance is a cardinal feature of systemic lupus erythematosus (SLE). Increased numbers of autoreactive mature naïve B cells have been described in SLE patients and autoantibodies have been shown to arise from autoreactive and non-autoreactive precursors. How these defects, in the regulation of B cell tolerance and selection, influence germinal center (GC) reactions that are directed towards foreign antigens has yet to be investigated. Here, we examined the characteristics of post-GC foreign antigen-specific B cells from SLE patients and healthy controls by analyzing monoclonal antibodies generated from plasmablasts induced specifically by influenza vaccination. We report that many of the SLE patients had anti-influenza antibodies with higher binding affinity and neutralization capacity than those from controls. Although overall frequencies of autoreactivity in the influenza-specific plasmablasts were similar for SLE patients and controls, the variable gene repertoire of influenza-specific plasmablasts from SLE patients was altered, with increased usage of JH6 and long heavy chain CDR3 segments. We found that high affinity anti-influenza antibodies generally characterize the plasmablast responses of SLE patients with low levels of autoreactivity; however, certain exceptions were noted. The high-avidity antibody responses in SLE patients may also be correlated with cytokines that are abnormally expressed in lupus. These findings provide insights into the effects of dysregulated immunity on the quality of antibody responses following influenza vaccination and further our understanding of the underlying abnormalities of lupus.

  13. High Affinity Antibodies against Influenza Characterize the Plasmablast Response in SLE Patients After Vaccination.

    Directory of Open Access Journals (Sweden)

    Kaval Kaur

    Full Text Available Breakdown of B cell tolerance is a cardinal feature of systemic lupus erythematosus (SLE. Increased numbers of autoreactive mature naïve B cells have been described in SLE patients and autoantibodies have been shown to arise from autoreactive and non-autoreactive precursors. How these defects, in the regulation of B cell tolerance and selection, influence germinal center (GC reactions that are directed towards foreign antigens has yet to be investigated. Here, we examined the characteristics of post-GC foreign antigen-specific B cells from SLE patients and healthy controls by analyzing monoclonal antibodies generated from plasmablasts induced specifically by influenza vaccination. We report that many of the SLE patients had anti-influenza antibodies with higher binding affinity and neutralization capacity than those from controls. Although overall frequencies of autoreactivity in the influenza-specific plasmablasts were similar for SLE patients and controls, the variable gene repertoire of influenza-specific plasmablasts from SLE patients was altered, with increased usage of JH6 and long heavy chain CDR3 segments. We found that high affinity anti-influenza antibodies generally characterize the plasmablast responses of SLE patients with low levels of autoreactivity; however, certain exceptions were noted. The high-avidity antibody responses in SLE patients may also be correlated with cytokines that are abnormally expressed in lupus. These findings provide insights into the effects of dysregulated immunity on the quality of antibody responses following influenza vaccination and further our understanding of the underlying abnormalities of lupus.

  14. Interactions between HIV-1 Neutralizing Antibodies and Model Lipid Membranes imaged with AFM

    Science.gov (United States)

    Zauscher, Stefan; Hardy, Gregory; Alam, Munir; Shapter, Joseph

    2012-02-01

    Lipid membrane interactions with rare, broadly neutralizing antibodies (NAbs), 2F5 and 4E10, play a critical role in HIV-1 neutralization. Our research is motivated by recent immunization studies that have shown that induction of antibodies that avidly bind the gp41-MPER antigen is not sufficient for neutralization. Rather, it is required that antigen designs induce polyreactive antibodies that recognize MPER antigens as well as the viral lipid membrane. However, the mechanistic details of how membrane properties influence NAb-lipid and NAb-antigen interactions remain unknown. Furthermore, it is well established that the native viral membrane is heterogeneous, representing a mosaic of lipid rafts and protein clustering. However, the size, physical properties, and dynamics of these regions are poorly characterized and their potential roles in HIV-1 neutralization are also unknown. To understand how membrane properties contribute to 2F5/4E10 membrane interactions, we have engineered biomimetic supported lipid bilayers (SLBs) and use atomic force microscopy to visualize membrane domains, antigen clustering, and antibody-membrane interactions at sub-nanometer z-resolution. Our results show that localized binding of HIV-1 antigens and NAbs occur preferentially with the most fluid membrane domain. This supports the theory that NAbs may interact with regions of low lateral lipid forces that allow antibody insertion into the bilayer.

  15. Maternal immunoglobulin G avidity as a diagnostic tool to identify pregnant women at risk of congenital cytomegalovirus infection.

    Science.gov (United States)

    Kaneko, Masatoki; Ohhashi, Masanao; Minematsu, Toshio; Muraoka, Junsuke; Kusumoto, Kazumi; Sameshima, Hiroshi

    2017-03-01

    The immunoglobulin (Ig) G avidity index (AI) is useful to detect primary cytomegalovirus (CMV) infection. However, because IgG matures with time, this index is not useful to detect a primary infection, unless measured at an appropriate time. We aimed to clarify the difference between using IgG AI and IgM positivity according to the stage of pregnancy to identify congenital CMV infection risk. We collected the serum samples from 1115 pregnant women who underwent maternal screening for primary infection (n = 956) and were referred to our hospital because of CMV IgM positivity (n = 155) or had abnormal fetal ultrasonography findings (n = 4). The same sera samples were used to measure CMV IgM, IgG, and IgG AI. An IgG AI of <35% was defined as low. Neonatal urine collected within 5 days after birth was examined by polymerase chain reaction to confirm congenital infection. Fourteen mothers gave birth to infected neonates. The sensitivity, specificity, and negative predictive values of the low IgG AI group with IgM-positive samples to discriminate between women with congenital infection at ≤14 weeks of gestation were 83.3, 83.8, and 99.1, respectively, which were higher than those of other subjects. Uni- and multivariate analyses revealed that IgM positivity and low IgG AI were independent variables associated with congenital infection at any stage of pregnancy, except low IgG AI at ≥15 weeks of gestation. Low IgG AI with IgM positivity at ≤14 weeks of gestation was a good indicator of congenital infection, which should prove useful in obstetric practice. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  16. Normal physiologic and Benign foci with F-18 FDG avidity on PET/CT in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soon Ah; Lee, Kwang Man; Choi, Un Jong; Kim, Hun Soo; Kim, Hye Won; Song, Jeong Hoon [College of Medicine, Wonkwnag University, Iksan (Korea, Republic of)

    2010-12-15

    The aim of this study was to evaluate the physiologic and benign F-18 fluorodeoxyglucose (FDG) avid foci in patients with breast cancer. On 309 F-18 FDG PET/CT scans of 241 women with breast cancer, the hypermetabolic lesions compared with the surrounding normal region were evaluated retrospectively. Available reports of other relevant radiological imaging medical records, and follow-up PET/CT were reviewed for explanations of the abnormal uptake. Among the 70 physiologic foci, muscular uptake of the lower neck following the surgical and/or radiation therapy of ipsilateral breast (29%), hypermetabolic ovaries (16%) and uterine (10%) uptake during the ovulatory and menstrual phases during the normal menstrual cycle were identified, and also hypermetabolic brown fat in cold-induced thermogenesis (7%), non-specific bowel uptake (35%) were observed. Among the 147 benign lesions, sequelae of the chest wall and breasts following surgical and/or radiation therapy, were often observed (27%). Hypermetabolic thyroid glands were noted as adenomas and chronic thyroiditis (18%). Reactive hyperplasia of cervical or mediastinal lymph nodes (32%), degenerative osteoarthritis and healed fractures (15%), hypermetabolic benign lung lesions (6%) were observed. Altered physiologic and benign F-18 FDG uptake in the cervical muscle and chest wall following ipsilateral breast surgery or radiotherapy were common, and also normal physiologic uptake in ovary and uterus, brown fat, thyroid were considered as predominant findings in women patients with breast cancer. Knowledge of these findings might aid in the interpretation of FDG PET/CT in patients with breast cancer

  17. Thermodynamic Mechanism for the Evasion of Antibody Neutralization in Flaviviruses

    Science.gov (United States)

    2015-01-01

    Mutations in the epitopes of antigenic proteins can confer viral resistance to antibody-mediated neutralization. However, the fundamental properties that characterize epitope residues and how mutations affect antibody binding to alter virus susceptibility to neutralization remain largely unknown. To address these questions, we used an ensemble-based algorithm to characterize the effects of mutations on the thermodynamics of protein conformational fluctuations. We applied this method to the envelope protein domain III (ED3) of two medically important flaviviruses: West Nile and dengue 2. We determined an intimate relationship between the susceptibility of a residue to thermodynamic perturbations and epitope location. This relationship allows the successful identification of the primary epitopes in each ED3, despite their high sequence and structural similarity. Mutations that allow the ED3 to evade detection by the antibody either increase or decrease conformational fluctuations of the epitopes through local effects or long-range interactions. Spatially distant interactions originate in the redistribution of conformations of the ED3 ensembles, not through a mechanically connected array of contiguous amino acids. These results reconcile previous observations of evasion of neutralization by mutations at a distance from the epitopes. Finally, we established a quantitative correlation between subtle changes in the conformational fluctuations of the epitope and large defects in antibody binding affinity. This correlation suggests that mutations that allow viral growth, while reducing neutralization, do not generate significant structural changes and underscores the importance of protein fluctuations and long-range interactions in the mechanism of antibody-mediated neutralization resistance. PMID:24950171

  18. Immunotherapy of cancer: from monoclonal to oligoclonal cocktails of anti‐cancer antibodies: IUPHAR Review 18

    Science.gov (United States)

    Carvalho, Silvia; Levi‐Schaffer, Francesca; Sela, Michael

    2016-01-01

    Antibody‐based therapy of cancer employs monoclonal antibodies (mAbs) specific to soluble ligands, membrane antigens of T‐lymphocytes or proteins located at the surface of cancer cells. The latter mAbs are often combined with cytotoxic regimens, because they block survival of residual fractions of tumours that evade therapy‐induced cell death. Antibodies, along with kinase inhibitors, have become in the last decade the mainstay of oncological pharmacology. However, partial and transient responses, as well as emergence of tumour resistance, currently limit clinical application of mAbs. To overcome these hurdles, oligoclonal antibody mixtures are being tested in animal models and in clinical trials. The first homo‐combination of two mAbs, each engaging a distinct site of HER2, an oncogenic receptor tyrosine kinase (RTK), has been approved for treatment of breast cancer. Likewise, a hetero‐combination of antibodies to two distinct T‐cell antigens, PD1 and CTLA4, has been approved for treatment of melanoma. In a similar vein, additive or synergistic anti‐tumour effects observed in animal models have prompted clinical testing of hetero‐combinations of antibodies simultaneously engaging distinct RTKs. We discuss the promise of antibody cocktails reminiscent of currently used mixtures of chemotherapeutics and highlight mechanisms potentially underlying their enhanced clinical efficacy. PMID:26833433

  19. How Innate Immune Mechanisms Contribute to Antibody-Enhanced Viral Infections ▿

    Science.gov (United States)

    Ubol, Sukathida; Halstead, Scott B.

    2010-01-01

    Preexisting antibodies may enhance viral infections. In dengue, nonneutralizing antibodies raised by natural infection with one of four dengue viruses (DENVs) may enhance infection with a different virus by a process we term “intrinsic antibody-dependent enhancement” (iADE). In addition, nonprotective antibodies raised by formalin-inactivated respiratory syncytial virus (RSV) and measles virus vaccines have led to enhanced disease during breakthrough infections. Infections under iADE conditions not only facilitate the process of viral entry into monocytes and macrophages but also modify innate and adaptive intracellular antiviral mechanisms, suppressing type 1 interferon (IFN) production and resulting in enhanced DENV replication. The suppression observed in vitro has been documented in patients with severe (dengue hemorrhagic fever [DHF]) but not in patient with mild (dengue fever [DF]) secondary dengue virus infections. Important veterinary viral infections also may exhibit iADE. It is thought that use of formalin deconforms viral epitopes of RSV, resulting in poor Toll-like receptor (TLR) stimulation; suboptimal maturation of dendritic cells with reduced production of activation factors CD40, CD80, and CD86; decreased germinal center formation in lymph nodes; and the production of nonprotective antibodies. These antibodies fail to neutralize RSV, allowing replication with secondary stimulation of RSV-primed Th2 cells producing more low-avidity antibody, resulting in immune complexes deposited into affected tissue. However, when formalin-inactivated RSV was administered with a TLR agonist to mice, they were protected against wild-type virus challenge. Safe and effective vaccines against RSV/measles virus and dengue virus may benefit from a better understanding of how innate immune responses can promote production of protective antibodies. PMID:20876821

  20. Occurrence of anti-Toxoplasma gondii antibodies in meat and dairy goat herds in Rio Grande do Norte, Brazil

    Directory of Open Access Journals (Sweden)

    Andréa Dantas de Medeiros

    2014-12-01

    Full Text Available Toxoplasmosis is caused by Toxoplasma gondii, which is the main causative agent of abortion in small ruminants. Goats are among the animals that are most susceptible to this protozoon, and the disease that it causes leads to significant economic losses and has implications for public health, since presence of the parasite in products of goat origin is one of the main sources of human infection. Because of the significant economic impact, there is an urgent need to study the prevalence of T. gondii infection among goats in Sertão do Cabugi, which is the largest goat-producing region in Rio Grande do Norte. In the present study, the ELISA assay was used to test 244 serum samples from nine farms, located in four different municipalities in the Sertão do Cabugi region, which is an important goat-rearing region. The results showed that the prevalence of anti-T. gondii antibodies was 47.1% and that there was a significant association between positivity and the variables of age (≥ 34 months, location (Lajes, Angicos and Afonso Bezerra and farm (all the farms. The avidity test was applied to all the 115 ELISA-positive samples to distinguish between acute and chronic infection. One hundred and three samples (89.6% displayed high-avidity antibodies, thus indicating that most of the animals presented chronic infection, with a consequent great impact on the development of the goat production system and a risk to human health.

  1. Vesicular monoamine transporter protein expression correlates with clinical features, tumor biology, and MIBG avidity in neuroblastoma: a report from the Children's Oncology Group

    Energy Technology Data Exchange (ETDEWEB)

    Temple, William; Mendelsohn, Lori; Nekritz, Erin; Gustafson, W.C.; Matthay, Katherine K. [UCSF School of Medicine, Department of Pediatrics, San Francisco, CA (United States); UCSF Benioff Children' s Hospital, San Francisco, CA (United States); Kim, Grace E. [UCSF School of Medicine, Department of Pathology, San Francisco, CA (United States); Lin, Lawrence; Giacomini, Kathy [UCSF School of Pharmacy, Department of Bioengineering and Therapeutic Sciences, San Francisco, CA (United States); Naranjo, Arlene; Van Ryn, Collin [University of Florida, Children' s Oncology Group Statistics and Data Center, Gainesville, FL (United States); Yanik, Gregory A. [University of Michigan, CS Mott Children' s Hospital, Ann Arbor, MI (United States); Kreissman, Susan G. [Duke University Medical Center, Durham, NC (United States); Hogarty, Michael [University of Pennsylvania, Children' s Hospital of Philadelphia and Perelman School of Medicine, Philadelphia, PA (United States); DuBois, Steven G. [UCSF School of Medicine, Department of Pediatrics, San Francisco, CA (United States); UCSF Benioff Children' s Hospital, San Francisco, CA (United States); UCSF School of Medicine, San Francisco, CA (United States)

    2016-03-15

    Vesicular monoamine transporters 1 and 2 (VMAT1 and VMAT2) are thought to mediate MIBG uptake in adult neuroendocrine tumors. In neuroblastoma, the norepinephrine transporter (NET) has been investigated as the principal MIBG uptake protein, though some tumors without NET expression concentrate MIBG. We investigated VMAT expression in neuroblastoma and correlated expression with MIBG uptake and clinical features. We evaluated VMAT1 and VMAT2 expression by immunohistochemistry (IHC) in neuroblastoma tumors from 76 patients with high-risk metastatic disease treated in a uniform cooperative group trial (COG A3973). All patients had baseline MIBG diagnostic scans centrally reviewed. IHC results were scored as the product of intensity grading (0 - 3+) and percent of tumor cells expressing the protein of interest. The association between VMAT1 and VMAT2 scores and clinical and biological features was tested using Wilcoxon rank-sum tests. Patient characteristics were typical of high-risk neuroblastoma, though the cohort was intentionally enriched in patients with MIBG-nonavid tumors (n = 20). VMAT1 and VMAT2 were expressed in 62 % and 75 % of neuroblastoma tumors, respectively. VMAT1 and VMAT2 scores were both significantly lower in MYCN amplified tumors and in tumors with high mitotic karyorrhectic index. MIBG-avid tumors had significantly higher VMAT2 scores than MIBG-nonavid tumors (median 216 vs. 45; p = 0.04). VMAT1 expression did not correlate with MIBG avidity. VMAT1 and VMAT2 are expressed in the majority of neuroblastomas. Expression correlates with other biological features. The expression level of VMAT2 but not that of VMAT1 correlates with avidity for MIBG. (orig.)

  2. Escape is a more common mechanism than avidity reduction for evasion of CD8+ T cell responses in primary human immunodeficiency virus type 1 infection

    Directory of Open Access Journals (Sweden)

    Williams Ian

    2011-06-01

    Full Text Available Abstract Background CD8+ T cells play an important role in control of viral replication during acute and early human immunodeficiency virus type 1 (HIV-1 infection, contributing to containment of the acute viral burst and establishment of the prognostically-important persisting viral load. Understanding mechanisms that impair CD8+ T cell-mediated control of HIV replication in primary infection is thus of importance. This study addressed the relative extent to which HIV-specific T cell responses are impacted by viral mutational escape versus reduction in response avidity during the first year of infection. Results 18 patients presenting with symptomatic primary HIV-1 infection, most of whom subsequently established moderate-high persisting viral loads, were studied. HIV-specific T cell responses were mapped in each individual and responses to a subset of optimally-defined CD8+ T cell epitopes were followed from acute infection onwards to determine whether they were escaped or declined in avidity over time. During the first year of infection, sequence variation occurred in/around 26/33 epitopes studied (79%. In 82% of cases of intra-epitopic sequence variation, the mutation was confirmed to confer escape, although T cell responses were subsequently expanded to variant sequences in some cases. In contrast, Conclusions Escape appears to constitute a much more important means of viral evasion of CD8+ T cell responses in acute and early HIV infection than decline in functional avidity of epitope-specific T cells. These findings support the design of vaccines to elicit T cell responses that are difficult for the virus to escape.

  3. Loss of cell surface CD47 ‘clustering’ formation and binding avidity to SIRPα facilitate apoptotic cell clearance by macrophage

    Science.gov (United States)

    Lv, Zhiyuan; Bian, Zhen; Shi, Lei; Niu, Shuo; Ha, Bin; Tremblay, Alexandra; Li, Liangwei; Zhang, Xiugen; Paluszynski, John; Liu, Ming; Zen, Ke; Liu, Yuan

    2015-01-01

    CD47, a ‘self’ recognition marker expressed on tissue cells, interacts with immunoreceptor SIRPα expressed on the surface of macrophages to initiate inhibitory signaling that prevents macrophage phagocytosis of healthy host cells. Previous studies have suggested that cells may lose the surface CD47 during aging or apoptosis to enable phagocytic clearance. In the present study, we demonstrate that the level of cell surface CD47 is not decreased but the distribution pattern of CD47 is altered during apoptosis. On non-apoptotic cells, CD47 molecules are clustered in lipid rafts forming ‘punctates’ on the surface, whereas on apoptotic cells, CD47 molecules are diffused on the cell surface following the disassembly of lipid rafts. We show that clustering of CD47 in lipid rafts provides a high binding avidity for cell surface CD47 to ligate macrophage SIRPα, which also presents as clusters, and elicit SIRPα-mediated inhibitory signaling that prevents phagocytosis. In contrast, dispersed CD47 on the apoptotic cell surface is associated a significant reduction of the binding avidity to SIRPα and failure to trigger SIRPα signal transduction. Disruption of lipid rafts with methyl-β-cyclodextrin (MβCD) disrupted CD47 cluster formation on the cell surfaces, leading to decrease of the binding avidity to SIRPα and a concomitant increase of cells being engulfed by macrophages. Taken together, our study reveals that CD47 normally is clustered in lipid rafts on non-apoptotic cells but is diffused in the plasma membrane when apoptosis occurs, and this transformation of CD47 greatly reduces the strength of CD47-SIRPα engagement, resulting in the phagocytosis of apoptotic cells. PMID:26085683

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

    Science.gov (United States)

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

    2015-10-01

    Since the invention of phage display, in vitro antibody display technologies have revolutionized the field of antibody discovery. In combination with antibody libraries constructed with sequences of human origin, such technologies enable accelerated therapeutic antibody discovery while bypassing the laborious animal immunization and hybridoma generation processes. Many in vitro display technologies developed since aim to differentiate from phage display by displaying full-length IgG proteins, utilizing eukaryotic translation system and codons, increasing library size or real-time kinetic selection by fluorescent activated cell sorting. We report here the development of an mRNA display technology and an accompanying HCDR3 size spectratyping monitor for human antibody discovery. Importantly, the mRNA display technology maintains a monovalent linkage between the mRNA (genotype) and display binding protein (phenotype), which minimizes avidity effect common in other display systems and allows for a stringent affinity and off-rate selection. The mRNA display technology successfully identified 100 human antibodies in 15 different selections against various targets from naïve human antibody libraries. These antibodies in general have high affinity and diversity. By analyzing the germline usage and combination of antibodies selected by the mRNA display technology, we identified trends and determined the productivity of each germline subgroup in the libraries that could serve as the knowledge base for constructing fully synthetic, next generation antibody libraries. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. The quantum chemical causality of pMHC-TCR biological avidity: Peptide atomic coordination data and the electronic state of agonist N termini

    Directory of Open Access Journals (Sweden)

    Georgios S.E. Antipas

    2015-06-01

    Full Text Available The quantum state of functional avidity of the synapse formed between a peptide-Major Histocompatibility Complex (pMHC and a T cell receptor (TCR is a subject not previously touched upon. Here we present atomic pair correlation meta-data based on crystalized tertiary structures of the Tax (HTLV-1 peptide along with three artificially altered variants, all of which were presented by the (Class I HLA-A201 protein in complexation with the human (CD8+ A6TCR. The meta-data reveal the existence of a direct relationship between pMHC-TCR functional avidity (agonist/antagonist and peptide pair distribution function (PDF. In this context, antagonist peptides are consistently under-coordinated in respect to Tax. Moreover, Density Functional Theory (DFT datasets in the BLYP/TZ2P level of theory resulting from relaxation of the H species on peptide tertiary structures reveal that the coordination requirement of agonist peptides is also expressed as a physical observable of the protonation state of their N termini: agonistic peptides are always found to retain a stable ammonium (NH3+ terminal group while antagonist peptides are not.

  6. The quantum chemical causality of pMHC-TCR biological avidity: Peptide atomic coordination data and the electronic state of agonist N termini.

    Science.gov (United States)

    Antipas, Georgios S E; Germenis, Anastasios E

    2015-06-01

    The quantum state of functional avidity of the synapse formed between a peptide-Major Histocompatibility Complex (pMHC) and a T cell receptor (TCR) is a subject not previously touched upon. Here we present atomic pair correlation meta-data based on crystalized tertiary structures of the Tax (HTLV-1) peptide along with three artificially altered variants, all of which were presented by the (Class I) HLA-A201 protein in complexation with the human (CD8(+)) A6TCR. The meta-data reveal the existence of a direct relationship between pMHC-TCR functional avidity (agonist/antagonist) and peptide pair distribution function (PDF). In this context, antagonist peptides are consistently under-coordinated in respect to Tax. Moreover, Density Functional Theory (DFT) datasets in the BLYP/TZ2P level of theory resulting from relaxation of the H species on peptide tertiary structures reveal that the coordination requirement of agonist peptides is also expressed as a physical observable of the protonation state of their N termini: agonistic peptides are always found to retain a stable ammonium (NH3 (+)) terminal group while antagonist peptides are not.

  7. Antibody blocks acquisition of bacterial colonization through agglutination.

    Science.gov (United States)

    Roche, A M; Richard, A L; Rahkola, J T; Janoff, E N; Weiser, J N

    2015-01-01

    Invasive infection often begins with asymptomatic colonization of mucosal surfaces. A murine model of bacterial colonization with Streptococcus pneumoniae was used to study the mechanism for mucosal protection by immunoglobulin. In previously colonized immune mice, bacteria were rapidly sequestered within large aggregates in the nasal lumen. To further examine the role of bacterial agglutination in protection by specific antibodies, mice were passively immunized with immunoglobulin G (IgG) purified from antipneumococcal sera or pneumococcal type-specific monoclonal human IgA (hIgA1 or hIgA2). Systemically delivered IgG accessed the mucosal surface and blocked acquisition of colonization and transmission between littermates. Optimal protection by IgG was independent of Fc fragment and complement and, therefore, did not involve an opsonophagocytic mechanism. Enzymatic digestion or reduction of IgG before administration showed that protection required divalent binding that maintained its agglutinating effect. Divalent hIgA1 is cleaved by the pneumococcal member of a family of bacterial proteases that generate monovalent Fabα fragments. Thus, passive immunization with hIgA1 blocked colonization by an IgA1-protease-deficient mutant (agglutinated) but not the protease-producing wild-type parent (not agglutinated), whereas protease-resistant hIgA2 agglutinated and blocked colonization by both. Our findings highlight the importance of agglutinating antibodies in mucosal defense and reveal how successful pathogens evade this effect.

  8. 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…

  9. Expression of recombinant Antibodies

    Directory of Open Access Journals (Sweden)

    André eFrenzel

    2013-07-01

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

  10. Expression of Recombinant Antibodies

    Science.gov (United States)

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines, and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications. PMID:23908655

  11. Antigenic determinants of influenza virus hemagglutinin. XI. Conformational changes detected by monoclonal antibodies.

    Science.gov (United States)

    Jackson, D C; Nestorowicz, A

    1985-08-01

    At pH 5 influenza virus hemagglutinin undergoes an irreversible conformational change (J.J. Skehel, P. M. Bayley, E. B. Brown, S. R. Martin, M. D. Waterfield, J. M. White, I. A. Wilson, and D. C. Wiley (1982). Proc. Natl. Acad. Sci. USA 79, 968-972) which parallels the appearance of fusion activity of this molecule. This paper describes experiments which explore the conformational change using a panel of monoclonal antibodies which define four of the major antigenic sites of this protein. The results indicate that three of the major antigenic sites of hemagglutinin undergo changes when exposed to acid pH. These changes have little effect on the binding avidity of influenza virus to glycophorin, the major receptor present on the red blood cell surface. These findings have been used to postulate a mechanism where the molecule flexes around a central region resulting in rearrangement in space of its component domains on exposure to low pH.

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

    Directory of Open Access Journals (Sweden)

    Ponraj ePrabakaran

    2012-08-01

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

  13. Antibody engineering: methods and protocols

    National Research Council Canada - National Science Library

    Chames, Patrick

    2012-01-01

    "Antibody Engineering: Methods and Protocols, Second Edition was compiled to give complete and easy access to a variety of antibody engineering techniques, starting from the creation of antibody repertoires and efficient...

  14. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test; Insulin resistance - insulin antibodies; Diabetes - insulin antibodies ... You appear to have an allergic response to insulin Insulin no longer seems to control your diabetes

  15. Evaluation of the TGS TA system for the detection of anti-rubella antibodies

    Directory of Open Access Journals (Sweden)

    Olivia Arpino

    2017-07-01

    Full Text Available Background and aims: The aim of the present study was to evaluate the new Technogenetics TGS TA system for detecting antirubella IgG and IgM antibodies and IgG avidity. TGS TA system was compared with our routinely used system, LIAISON XL, for the detection of IgG and IgM antibodies. Only in positive IgM samples (retrospective study, TGS TA system was compared to an ELFA IgM test and with an ELISA test for the IgG avidity (if existent.Materials and methods: Two hundred and seventy six sera samples from women were examined with TGS TA system and divided in 3 groups according to IgG and IgM screening LIAISON XL tests: 112 were of childbearing age and non-immune women (Group 1, 106 were pregnant with past infection or vaccinated (Group 2 and 49 were pregnant with positive or equivocal IgM (Group 3. Results: The overall concordance of the IgG results between LIAISON XL and TGS TA was 93.3%: 86.6% in Group 1, 97.2% in Group 2 and 100% in Group 3. The overall concordance of the IgM results between LIAISON XL and TGS TA was 89.0%: 100% in Group 1, 100% in Group 2 and 35.6% in Group 3. In Group 3, the concordance between the results of the IgG avidity with the ELISA and TGS TA tests was 85.7%. Comparing the clinical diagnosis obtained with our protocol and that of the TGS TA system, the overall concordance was 97.4%: 86.6% in Group 1, 97.2% in Group 2 and 85.7% in Group 3. Conclusions: TGA TS system shows to be a valuable tool with overall good clinical correlation and able to clearly identify nonspecific subjects, those with a non-recent infection or those who are vaccinated. The TGS TA test also seems to be especially sensitive in indicating vaccinated subjects with low IgG levels as immune.

  16. Monoclonal antibody "gold rush".

    Science.gov (United States)

    Maggon, Krishan

    2007-01-01

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

  17. Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16

    Energy Technology Data Exchange (ETDEWEB)

    Pancera, Marie; Shahzad-ul-Hussan, Syed; Doria-Rose, Nicole A.; McLellan, Jason S.; Bailer, Robert T.; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K.; Staupe, Ryan P.; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E.; Blinn, Julie; Alam, S. Munir; Haynes, Barton F.; Amin, Mohammed N.; Wang, Lai-Xi; Burton, Dennis R.; Koff, Wayne C.; Nabel, Gary J.; Mascola, John R.; Bewley, Carole A; Kwong, Peter D. [NIH; (Scripps); (Duke); (Maryland-MED); (IAVI)

    2013-08-05

    HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1–V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1–V2, showing an epitope comprising both high mannose–type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1–glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

  18. Antithyroid microsomal antibody

    Science.gov (United States)

    ... to confirm the cause of thyroid problems, including Hashimoto thyroiditis . The test is also used to find ... positive test may be due to: Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also ...

  19. Serum herpes simplex antibodies

    Science.gov (United States)

    ... causes cold sores (oral herpes). HSV-2 causes genital herpes. How the Test is Performed A blood sample ... person has ever been infected with oral or genital herpes . It looks for antibodies to herpes simplex virus ...

  20. ANA (Antinuclear Antibody Test)

    Science.gov (United States)

    ... Testing Leptin Levetiracetam Lipase Lipid Profile Lipoprotein (a) Lithium Liver Panel Lp-PLA2 Lupus Anticoagulant Testing Luteinizing ... Scleroderma Elsewhere On The Web Lupus Foundation of America American College of Rheumatology: Antinuclear Antibodies (ANA) American ...

  1. Anti-sulfotyrosine antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Bertozzi, Carolyn R [Berkeley, CA; Kehoe, John [Saint Davids, PA; Bradbury, Andrew M [Santa Fe, NM

    2009-09-15

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

  2. Antibody Blood Tests

    Science.gov (United States)

    Antibody Blood Tests Researchers have discovered that people with celiac disease who eat gluten have higher than normal levels of ... do I do if I have a negative blood test (or panel) but I’m still having symptoms? ...

  3. Expression of Recombinant Antibodies

    OpenAIRE

    André eFrenzel; Michael eHust; Thomas eSchirrmann

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transg...

  4. HIV-1 evades virus-specific IgG2 and IgA responses by targeting systemic and intestinal B cells via long-range intercellular conduits.

    Science.gov (United States)

    Xu, Weifeng; Santini, Paul A; Sullivan, John S; He, Bing; Shan, Meimei; Ball, Susan C; Dyer, Wayne B; Ketas, Thomas J; Chadburn, Amy; Cohen-Gould, Leona; Knowles, Daniel M; Chiu, April; Sanders, Rogier W; Chen, Kang; Cerutti, Andrea

    2009-09-01

    Contact-dependent communication between immune cells generates protection but also facilitates viral spread. Here we found that macrophages formed long-range actin-propelled conduits in response to negative factor (Nef), a human immunodeficiency virus type 1 (HIV-1) protein with immunosuppressive functions. Conduits attenuated immunoglobulin G2 (IgG2) and IgA class switching in systemic and intestinal lymphoid follicles by shuttling Nef from infected macrophages to B cells through a guanine-exchange factor-dependent pathway involving the amino-terminal anchor, central core and carboxy-terminal flexible loop of Nef. By showing stronger virus-specific IgG2 and IgA responses in patients with Nef-deficient virions, our data suggest that HIV-1 exploits intercellular 'highways' as a 'Trojan horse' to deliver Nef to B cells and evade humoral immunity systemically and at mucosal sites of entry.

  5. A study of T cell tolerance to the tumor-associated antigen MDM2: cytokines can restore antigen responsiveness, but not high avidity T cell function.

    Directory of Open Access Journals (Sweden)

    Gavin M Bendle

    Full Text Available BACKGROUND: Most tumor-associated antigens (TAA currently used for immunotherapy of cancer are also expressed in normal tissues, which may induce tolerance and impair T cell-mediated immunity. However, there is limited information about how physiological expression in normal tissues alters the function of TAA-specific T cells. METHODOLOGY/PRINCIPAL FINDINGS: We used a T cell receptor transgenic model to study how MDM2 expression in normal tissues affects the function of T cells specific for this TAA that is found at high levels in many different types of tumors. We found that some MDM2-specific T cells escaped thymic deletion and persisted in the peripheral T cell pool. When stimulated with antigen, these T cells readily initiated cell division but failed to proliferate and expand, which was associated with a high rate of apoptosis. Both IL-2 and IL-15 efficiently rescued T cell survival and antigen-specific T cell proliferation, while IL-7 and IL-21 were ineffective. Antigen-stimulated T cells showed impaired expression of the effector molecules CD43, granzyme-B and IFN-gamma, a defect that was completely restored when T cells were stimulated in the presence of IL-2. In contrast, IL-15 and IL-21 only restored the expression of CD43 and granzyme-B, but not IFN-gamma production. Finally, peptide titration experiments with IL-2 rescued T cells indicated that they were of lower avidity than non-tolerant control T cells expressing the same TCR. CONCLUSIONS/SIGNIFICANCE: These data indicate that cytokines can rescue the antigen-specific proliferation and effector function of MDM2-specific T cells, although this does not lead to the recovery of high avidity T cell function. This study sheds light on possible limitations of immunotherapy approaches that target widely expressed TAA, such as MDM2.

  6. Duration of {sup 18}F-FDG avidity in lymph nodes after pandemic H1N1v and seasonal influenza vaccination

    Energy Technology Data Exchange (ETDEWEB)

    Thomassen, Anders; Lerberg Nielsen, Anne; Gerke, Oke; Johansen, Allan; Petersen, Henrik [OUH, Odense University Hospital, Department of Nuclear Medicine, Odense C (Denmark)

    2011-05-15

    The aim of our study was to investigate the occurrence of fluorodeoxyglucose (FDG) avidity in draining axillary lymph nodes after vaccination against influenza (H1N1v pandemic and seasonal) and to determine the period of increased FDG uptake. During December 2009, patients referred for {sup 18}F-FDG positron emission tomography (PET)/CT scans (n = 293) filled in a questionnaire concerning vaccination type (seasonal and/or H1N1v), time and anatomical localization of vaccination. Only injections in deltoid regions were evaluated, thus ensuring that draining lymph nodes were axillary. If more vaccinations had been given, only the latest vaccination was evaluated in each deltoid region. Of all patients who underwent PET/CT scans during December 2009, 26% had been vaccinated with at least one influenza vaccination in the deltoid region. A total of 92 'draining' and 60 'reference' (i.e. contralateral, non-vaccinated) axillary lymph nodes were evaluated in 61 patients (19 of 61 patients were scanned twice). The maximal intensity in FDG uptake (SUV{sub max}) in draining lymph nodes was 5 g/ml body weight (BW), whereas the maximal intensity in reference lymph nodes was 1.9 g/ml BW. The SUV{sub max} was normalized approximately 40 days after vaccination. No significant enlargement of metabolically active draining lymph nodes could be demonstrated on CT scan. Chemotherapy or immunosuppressive drugs given within 2 weeks from vaccination did not affect SUV{sub max} in the axillary lymph nodes. Influenza vaccination may lead to FDG-avid draining lymph nodes beyond 1 month. (orig.)

  7. Estimating False-Recent Classification for the Limiting-Antigen Avidity EIA and BED-Capture Enzyme Immunoassay in Vietnam: Implications for HIV-1 Incidence Estimates.

    Science.gov (United States)

    Shah, Neha S; Duong, Yen T; Le, Linh-Vi; Tuan, Nguyen Anh; Parekh, Bharat S; Ha, Hoang Thi Thanh; Pham, Quang Duy; Cuc, Cao Thi Thu; Dobbs, Trudy; Tram, Tran Hong; Lien, Truong Thi Xuan; Wagar, Nick; Yang, Chunfu; Martin, Amy; Wolfe, Mitchell; Hien, Nguyen Tran; Kim, Andrea A

    2017-06-01

    Laboratory tests that can distinguish recent from long-term HIV infection are used to estimate HIV incidence in a population, but can potentially misclassify a proportion of long-term HIV infections as recent. Correct application of an assay requires determination of the proportion false recents (PFRs) as part of the assay characterization and for calculating HIV incidence in a local population using a HIV incidence assay. From April 2009 to December 2010, blood specimens were collected from HIV-infected individuals attending nine outpatient clinics (OPCs) in Vietnam (four from northern and five from southern Vietnam). Participants were living with HIV for ≥1 year and reported no antiretroviral (ARV) drug treatment. Basic demographic data and clinical information were collected. Specimens were tested with the BED capture enzyme immunoassay (BED-CEIA) and the Limiting-antigen (LAg)-Avidity EIA. PFR was estimated by dividing the number of specimens classified as recent by the total number of specimens; 95% confidence intervals (CI) were calculated. Specimens that tested recent had viral load testing performed. Among 1,813 specimens (north, n = 942 and south, n = 871), the LAg-Avidity EIA PFR was 1.7% (CI: 1.2-2.4) and differed by region [north 2.7% (CI: 1.8-3.9) versus south 0.7% (CI: 0.3-1.5); p = .002]. The BED-CEIA PFR was 2.3% (CI: 1.7-3.0) and varied by region [north 3.4% (CI: 2.4-4.7) versus south 1.0% (CI: 0.5-1.2), p Vietnam.

  8. Modulation of human immune response by Echinococcus granulosus antigen B and its possible role in evading host defenses.

    Science.gov (United States)

    Riganò, R; Profumo, E; Bruschi, F; Carulli, G; Azzarà, A; Ioppolo, S; Buttari, B; Ortona, E; Margutti, P; Teggi, A; Siracusano, A

    2001-01-01

    By directly suppressing the function of certain immune cell subsets and by stimulating other cell populations related to immunopathology, parasite-derived substances play an important role in the chronic establishment of parasitic disease. Our objective was twofold: (i) to investigate further the role of Echinococcus granulosus antigen B (AgB) in the human early inflammatory response by determining its effect on polymorphonuclear cell (PMN) random migration, chemotaxis, and oxidative metabolism and (ii) to determine its action in acquired immunity by evaluating AgB and sheep hydatid fluid (SHF)-driven Th1 (gamma interferon [IFN-gamma] and interleukin 12 [IL-12]) and Th2 (IL-4 and IL-13) cytokine production by peripheral blood mononuclear cells (PBMC) from 40 patients who had cured or stable or progressive cystic echinococcosis. AgB significantly inhibited PMN recruitment but left their random migration and oxidative metabolism unchanged. Patients' PBMC stimulated with AgB produced IL-4 and IL-13 but did not produce IL-12. They also produced significantly lower IFN-gamma concentrations than did PBMC stimulated with SHF (P = 10(-5)). AgB skewed the Th1/Th2 cytokine ratios towards a preferentially immunopathology-associated Th2 polarization, predominantly in patients with progressive disease. AgB-stimulated patients' PBMC also proliferated less than SHF-stimulated PBMC (P = 9 x 10(-3)). In vitro Th2 cytokine production was reflected in vivo by elevated specific immunoglobulin E (IgE) and IgG4 antibodies binding to AgB. These findings confirm that AgB plays a role in the escape from early immunity by inhibiting PMN chemotaxis. They also add new information on the host-parasite relationship, suggesting that AgB exploits the activation of T helper cells by eliciting a nonprotective Th2 cell response.

  9. [Hog cholera virus: influence of colostral passive antibody on immune response of pig following vaccination with the rabbit adapted Chinese strain (author's transl)].

    Science.gov (United States)

    Mierzejewska, M; Tereszczuk, S; Corthier, G; Aynaud, J M

    1977-01-01

    Using the rabbit adapted chinese strain of Hog cholera, active immunization of piglets having passive colostral antibodies was studied. 65 piglets born from 11 sows were used. Concerning sows, vaccination was performed 5-6 months and 1 month before service (3 sows), 30 days (2 sows) and 60 days (3 sows) after service. Divided in 5 lots, piglets were vaccinated at 4 different periods after birth (15, 30, 60 and 90 days). Hog cholera immunity was determined for each animal by means of kinetic of serum neutralizing antibodies and resistance to virulent challenge performed 5 months after birth. High levels of neutralizing antibodies were observed in serum of each vaccinated sow at the time of farrowing. In piglets having ingested low quantities of colostrum, vaccination induces a good antigenic stimulation characterized by a normal humoral immune response and challenge resistance. But in piglets having ingested a normal quantities of colostrum, colostral passive antibodies have a partial or complete suppressive effect on primary immune response which is characterized by a delay in serum antibodies formation and by a low level at the time of challenge. According the conditions of sows vaccination, differences were observed in the properties of colostral passive antibodies (intensity of suppressive effect on active immune response, in vitro "avidity" for Hog cholera virus, mean value of half-life) present in piglets serum. On practical aspect, vaccination with the chinese strain becomes fully effective in piglets having passive immunity when they are 30-60 days old.

  10. Natural and Man-made Antibody Repertories for Antibody Discovery

    Directory of Open Access Journals (Sweden)

    Juan C eAlmagro

    2012-11-01

    Full Text Available Antibodies are the fastest-growing segment of the biologics market. The success of antibody-based drugs resides in their exquisite specificity, high potency, stability, solubility, safety and relatively inexpensive manufacturing process in comparison with other biologics. We outline here the structural studies and fundamental principles that define how antibodies interact with diverse targets. We also describe the antibody repertoires and affinity maturation mechanisms of human, mice and chickens, plus the use of novel single-domain antibodies in camelids and sharks. These species all utilize diverse evolutionary solutions to generate specific and high affinity antibodies and illustrate the plasticity of natural antibody repertoires. In addition, we discuss the multiple variations of man-made antibody repertoires designed and validated in the last two decades, which have served as tools to explore how the size, diversity and composition of a repertoire impact the antibody discovery process.

  11. Monoclonal Antibodies production technology

    Directory of Open Access Journals (Sweden)

    Flávia Rocha

    2011-02-01

    Full Text Available Since the first cells were capable of maintain a continuous antibody supply, developed by Köhler and Milstein in 1975, its use in medicine and industry showed a great potential. New researches were developed to enhance the use of such cells, including immunizations, mieloma cells, fusion methodology, screening techniques, cloning, culture media, among several details which enable and optimizes its use. Nowadays, monoclonal antibodies are a well-established tool for proteomics research and it have countless applications on several knowledge areas, mainly human and/or animal disease diagnostic, identification and tracking of allergenic compounds in food and residues in the environment. This review can be used by professionals, researches and students searching for a compiled papers contributing to the improvement of the monoclonal antibodies technology, used at different knowledge areas such as human diseases and diseases and disorders in agriculture and livestock chain.

  12. Antibody affinity maturation

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise

    fragments by in vivo homologous recombination large combinatorial antibody libraries can easily be generated. We have optimized ordered assembly of three CDR fragments into a gapped vector and observed increased transformation efficiency in a yeast strain carrying a deletion of the SGS1 helicase...... surface expression of various antibody formats in the generated knockout strain. Functional scFv and scFab fragments were efficiently displayed on yeast whereas impaired chain assembly and heavy chain degradation was observed for display of full-length IgG molecules. To identify the optimal polypeptide...... linker for yeast surface display of scFv and scFab fragments, we compared a series of different Gly-Ser-based linkers in display and antigen binding proficiency. We show that these formats of the model antibody can accommodate linkers of different lengths and that introduction of alanine or glutamate...

  13. Identification of autoantigens recognized by the 2F5 and 4E10 broadly neutralizing HIV-1 antibodies

    Science.gov (United States)

    Yang, Guang; Holl, T. Matt; Liu, Yang; Li, Yi; Lu, Xiaozhi; Nicely, Nathan I.; Kepler, Thomas B.; Alam, S. Munir; Liao, Hua-Xin; Cain, Derek W.; Spicer, Leonard; VandeBerg, John L.; Haynes, Barton F.

    2013-01-01

    Many human monoclonal antibodies that neutralize multiple clades of HIV-1 are polyreactive and bind avidly to mammalian autoantigens. Indeed, the generation of neutralizing antibodies to the 2F5 and 4E10 epitopes of HIV-1 gp41 in man may be proscribed by immune tolerance because mice expressing the VH and VL regions of 2F5 have a block in B cell development that is characteristic of central tolerance. This developmental blockade implies the presence of tolerizing autoantigens that are mimicked by the membrane-proximal external region of HIV-1 gp41. We identify human kynureninase (KYNU) and splicing factor 3b subunit 3 (SF3B3) as the primary conserved, vertebrate self-antigens recognized by the 2F5 and 4E10 antibodies, respectively. 2F5 binds the H4 domain of KYNU which contains the complete 2F5 linear epitope (ELDKWA). 4E10 recognizes an epitope of SF3B3 that is strongly dependent on hydrophobic interactions. Opossums carry a rare KYNU H4 domain that abolishes 2F5 binding, but they retain the SF3B3 4E10 epitope. Immunization of opossums with HIV-1 gp140 induced extraordinary titers of serum antibody to the 2F5 ELDKWA epitope but little or nothing to the 4E10 determinant. Identification of structural motifs shared by vertebrates and HIV-1 provides direct evidence that immunological tolerance can impair humoral responses to HIV-1. PMID:23359068

  14. Development of IgY antibodies against anti-snake toxins endowed with highly lethal neutralizing activity.

    Science.gov (United States)

    da Rocha, David Gitirana; Fernandez, Jorge Hernandez; de Almeida, Cláudia Maria Costa; da Silva, Cláudia Letícia; Magnoli, Fábio Carlos; da Silva, Osmair Élder; da Silva, Wilmar Dias

    2017-08-30

    Snakebite envenoming is a major neglected disease related to poverty in developing countries. Treatment involves the administration of a specific antivenom serum and auxiliary therapies, if necessary. The improvement of antibodies is of great importance for the technological advancement of antivenom therapy and to reduce the morbidity and mortality associated with this medical burden. In the present study, adult hens were immunized nine times with 20μg of B. arietans or C. d. terrificus venoms at three-week intervals between immunizations. Developing antibodies presented increasing avidity and affinity to antigenic toxin epitopes along immunization, attaining a plateau after the seventh immunization. Pooled egg yolk-purified IgY antivenom antibodies, subjected to in vitro-in vivo lethality assay using Swiss adult mice, exhibited potent venom lethal neutralizing activity. Taken together, chickens under the described immunization schedule were considered alternative candidates for antivenom production. Lower maintenance costs, a simple antibody manufacturing process and immunization suffering restrictions are additional advantages. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Antibody informatics for drug discovery

    DEFF Research Database (Denmark)

    Shirai, Hiroki; Prades, Catherine; Vita, Randi

    2014-01-01

    to the antibody science in every project in antibody drug discovery. Recent experimental technologies allow for the rapid generation of large-scale data on antibody sequences, affinity, potency, structures, and biological functions; this should accelerate drug discovery research. Therefore, a robust bioinformatic...... infrastructure for these large data sets has become necessary. In this article, we first identify and discuss the typical obstacles faced during the antibody drug discovery process. We then summarize the current status of three sub-fields of antibody informatics as follows: (i) recent progress in technologies...... for antibody rational design using computational approaches to affinity and stability improvement, as well as ab-initio and homology-based antibody modeling; (ii) resources for antibody sequences, structures, and immune epitopes and open drug discovery resources for development of antibody drugs; and (iii...

  16. Prediction of Antibody Epitopes

    DEFF Research Database (Denmark)

    Nielsen, Morten; Marcatili, Paolo

    2015-01-01

    Antibodies recognize their cognate antigens in a precise and effective way. In order to do so, they target regions of the antigenic molecules that have specific features such as large exposed areas, presence of charged or polar atoms, specific secondary structure elements, and lack of similarity...... to self-proteins. Given the sequence or the structure of a protein of interest, several methods exploit such features to predict the residues that are more likely to be recognized by an immunoglobulin.Here, we present two methods (BepiPred and DiscoTope) to predict linear and discontinuous antibody...

  17. Immunochemical analyses of serum antibodies from pig herds in a Salmonella non-endemic region.

    Science.gov (United States)

    Wiuff, Camilla; Thorberg, Britt-Marie; Engvall, Anders; Lind, Peter

    2002-02-26

    In a large comparative survey of Danish and Swedish slaughter pig herds performed prior to this work, it was unexpectedly found that some Swedish herds harbored seropositive pigs. Serum samples from the Swedish herds had moderate responses in the Salmonella mix-ELISA (detecting serogroup B and C1 infections) compared to the Danish herds classifying some of them as seropositive using a cut-off value at 40 OD%. In Sweden, extensive Salmonella control is carried out by bacteriological screening of feces and lymph nodes, and the overall prevalence has been proven to be below 0.1%. The serological positive results were therefore unexpected; hence the reactivities of the Swedish sera were studied by a number of immunochemical analyses (Western blot, indirect ELISA, inhibition ELISA, avidity ELISA) and compared to sera from Danish pig herds with verified Salmonella infections ("the reference sera"). In Western blot, the Swedish sera had high binding reactivities against Salmonella Typhimurium LPS of different molecular weights, and gave binding patterns similar to that of the reference sera. Pre-incubation with free S. Typhimurium LPS or PS (the polysaccharide part of LPS) was able to inhibit the reactivity of the Swedish sera in the mix-ELISA. Reactivities against other related bacterial LPS such as Citrobacter freundii LPS and Yersinia enterocolitica O:3 LPS were observed in the Swedish sera, but these LPS antigens were unable to inhibit the reactivities in the mix-ELISA as efficiently as S. Typhimurium LPS. Furthermore, the Swedish sera did not bind Salmonella LPS of another serogroup (S. Meleagridis LPS, serogroup E1) or rough Salmonella LPS, both lacking the specific O-antigenic parts of S. Typhimurium LPS. The avidity of the Swedish sera was much lower than the avidity of the reference sera, which could indicate the presence of transient low-dose infections or stimulation by inactivated bacteria in feed. The results obtained in this investigation strongly indicate

  18. Generation and characterization of anti-Adeno-associated virus serotype 8 (AAV8) and anti-AAV9 monoclonal antibodies.

    Science.gov (United States)

    Tseng, Yu-Shan; Vliet, Kim Van; Rao, Lavanya; McKenna, Robert; Byrne, Barry J; Asokan, Aravind; Agbandje-McKenna, Mavis

    2016-10-01

    Adeno-associated viruses (AAVs) are promising viral vectors for therapeutic gene delivery, and the approval of an AAV1 vector for the treatment of lipoprotein lipase deficiency has heralded a new and exciting era for this system. However, preclinical and clinical studies show that neutralization from pre-existing antibodies is detrimental for medical application and this hurdle must be overcome before full clinical realization can be achieved. Thus the binding sites for capsid antibodies must be identified and eliminated through capsid engineering. Towards this goal and to recapitulate patient polyclonal responses, a panel of six new mouse monoclonal antibodies (MAbs) has been generated against AAV8 and AAV9 capsids, two vectors being developed for therapeutic application. Native (capsid) dot blot assays confirmed the specificity of these antibodies for their parental serotypes, with the exception of one MAb, HL2372, selected to cross-react against both capsids. Furthermore, in vitro assays showed that these MAbs are capable of neutralizing virus infection. These MAbs will be utilized for structural mapping of antigenic footprints on their respective capsids to inform development of the next generation of rAAV vectors capable of evading antibody neutralization while retaining parental tropism. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Compositions, antibodies, asthma diagnosis methods, and methods for preparing antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hongjun; Zangar, Richard C.

    2017-01-17

    Methods for preparing an antibody are provided with the method including incorporating 3-bromo-4-hydroxy-benzoic acid into a protein to form an antigen, immunizing a mammalian host with the antigen, and recovering an antibody having an affinity for the antigen from the host. Antibodies having a binding affinity for a monohalotyrosine are provided as well as composition comprising an antibody bound with monohalotyrosine. Compositions comprising a protein having a 3-bromo-4-hydroxy-benzoic acid moiety are also provided. Methods for evaluating the severity of asthma are provide with the methods including analyzing sputum of a patient using an antibody having a binding affinity for monohalotyrosine, and measuring the amount of antibody bound to protein. Methods for determining eosinophil activity in bodily fluid are also provided with the methods including exposing bodily fluid to an antibody having a binding affinity for monohalotyrosine, and measuring the amount of bound antibody to determine the eosinophil activity.

  20. Human germline antibody gene segments encode polyspecific antibodies.

    Science.gov (United States)

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

    2013-04-01

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

  1. Prediction of antibody persistency from antibody titres to natalizumab

    DEFF Research Database (Denmark)

    Jensen, Poul Erik H; Koch-Henriksen, Nils; Sellebjerg, Finn Thorup

    2012-01-01

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

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

    Science.gov (United States)

    Waldmann, Herman

    2014-01-01

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

  3. Monoclonal antibodies in haematopathology

    Energy Technology Data Exchange (ETDEWEB)

    Grignani, F.; Martelli, M.F.; Mason, D.Y.

    1985-01-01

    This book contains over 40 selections. Some of the titles are: Oncogene (c-myc, c-myb) amplification in acute myelogenous leukaemia; Ultrastructural characterization of leukaemic cells with monoloclonal antibodies; Origin of B-cell malignancies; Immunohistology of gut lymphomas; and Spurious evidence of lineage infidelity in monocytic leukaemia.

  4. Monoclonal antibodies in myeloma

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  5. Antibodies Targeting EMT

    Science.gov (United States)

    2015-10-01

    biomarkers. We have developed a new technique allowing for discovery of new antibodies that disrupt a key process in cancer progression termed...14 post Twist induction to trigger EMT. 7 within CDRH3s, the RGD motif could be indicative of ligand mimetic integrin binding properties of these

  6. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery...

  7. Sputum direct fluorescent antibody (DFA)

    Science.gov (United States)

    ... ency/article/003553.htm Sputum direct fluorescent antibody (DFA) test To use the sharing features on this page, please enable JavaScript. Sputum direct fluorescent antibody (DFA) is a lab test that looks for micro- ...

  8. PET/CT-guided percutaneous biopsy of FDG-avid metastatic bone lesions in patients with advanced lung cancer: a safe and effective technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wei; Hao, Bing; Chen, Hao-jun; Zhao, Long; Luo, Zuo-ming; Wu, Hua; Sun, Long [The First Affiliated Hospital of Xiamen University, Department of Nuclear Medicine and Minnan PET Center, Xiamen Cancer Hospital, Xiamen (China)

    2017-01-15

    {sup 18}F-FDG PET/CT should be performed before a diagnostic biopsy site is chosen in patients with a high clinical suspicion of aggressive, advanced tumour. The aim of this study was to evaluate the safety and efficacy of {sup 18}F-FDG PET/CT in guiding biopsy of bone metastases in patients with advanced lung cancer. PET/CT-guided percutaneous core biopsies were performed in 51 consecutive patients with suspected lung cancer and {sup 18}F-FDG-avid bone lesions after whole-body {sup 18}F-FDG PET/CT scans. Generally, one tissue sample was obtained from each patient. The final diagnoses were established on the basis of the histology results. The histopathological and molecular testing results were systematically evaluated. A total of 53 samples were obtained for histological examination or molecular testing as a second biopsy was required in two patients in whom the pathological diagnosis was unclear following the first biopsy. The pathological diagnosis and lung cancer classification were confirmed in 48 patients. The epidermal growth factor receptor mutation status was determined in 23 biopsies, and the mutation rate was 30.4 % (7/23). The anaplastic lymphoma kinase mutation status was determined in 19 biopsies, and the mutation rate was 31.6 % (6/19). Two of the 51 biopsies were positive for non-Hodgkin's lymphoma and one was positive for metastatic renal cell carcinoma. The first-time diagnostic success rate of biopsy was 96.1 % (49/51) and the overall diagnostic success rate and sensitivity were 100 %. All 51 patients were eventually confirmed as having stage IV disease. No serious complications were encountered and the average biopsy time was 30 min. PET/CT-guided percutaneous biopsy of {sup 18}F-FDG-avid bone metastases is an effective and safe method that yields a high diagnostic success rate in the evaluation of hypermetabolic bone lesions in patients with suspected advanced lung cancer. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Mayo Yasugi

    2013-02-01

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

  10. Antineurofilament antibodies in postpolio syndrome.

    Science.gov (United States)

    Drory, V E; Shapira, A; Korczyn, A D; Shavit, S; Kushnir, M; Michaelson, D M; Chapman, J

    1998-10-01

    We determined the levels of antineurofilament antibodies in 29 patients with postpolio syndrome (PPS), 26 stable postpolio (PP) patients, 22 patients with ALS, and 20 normal controls (NCs). Patients with PPS had higher antibody levels to cholinergic neurofilaments than did all other groups. PP patients and those with ALS had antibody levels similar to those of NCs. The antibody binding level showed no relation to the age of the patients, duration of disease, or motor score.

  11. Production of antibodies and antibody fragments in plants.

    Science.gov (United States)

    Peeters, K; De Wilde, C; De Jaeger, G; Angenon, G; Depicker, A

    2001-03-21

    Our current knowledge allows the generation of transgenic plants that efficiently produce heterologous proteins from plant, bacterial, fungal or animal origin. Among all types of recombinant proteins, antibodies are particularly attractive because of their ability to specifically recognize and bind virtually any type of antigen. Plants show several advantages as a large-scale antibody production system: they can be grown easily and inexpensively in large quantities that can be harvested, stored and processed by using existing infrastructures. Isolation and purification of plant-made antibodies, if necessary, allow fundamental, industrial, and therapeutical applications. In the past, we and others have successfully generated antibody-producing plants. The maximal accumulation levels of antibodies and antibody fragments that we observed are 1-5% of the extracted proteins. Currently, several biotechnological companies grow field crops to produce antibodies for ex planta applications on an industrial scale.

  12. Diversity of the murine antibody response targeting influenza A(H1N1pdm09) hemagglutinin.

    Science.gov (United States)

    Wilson, Jason R; Tzeng, Wen-Pin; Spesock, April; Music, Nedzad; Guo, Zhu; Barrington, Robert; Stevens, James; Donis, Ruben O; Katz, Jacqueline M; York, Ian A

    2014-06-01

    We infected mice with the 2009 influenza A pandemic virus (H1N1pdm09), boosted with an inactivated vaccine, and cloned immunoglobulins (Igs) from HA-specific B cells. Based on the redundancy in germline gene utilization, we inferred that between 72-130 unique IgH VDJ and 35 different IgL VJ combinations comprised the anti-HA recall response. The IgH VH1 and IgL VK14 variable gene families were employed most frequently. A representative panel of antibodies were cloned and expressed to confirm reactivity with H1N1pdm09 HA. The majority of the recombinant antibodies were of high avidity and capable of inhibiting H1N1pdm09 hemagglutination. Three of these antibodies were subtype-specific cross-reactive, binding to the HA of A/South Carolina/1/1918(H1N1), and one further reacted with A/swine/Iowa/15/1930(H1N1). These results help to define the genetic diversity of the influenza anti-HA antibody repertoire profile induced following infection and vaccination, which may facilitate the development of influenza vaccines that are more protective and broadly neutralizing. Protection against influenza viruses is mediated mainly by antibodies, and in most cases this antibody response is narrow, only providing protection against closely related viruses. In spite of this limited range of protection, recent findings indicate that individuals immune to one influenza virus may contain antibodies (generally a minority of the overall response) that are more broadly reactive. These findings have raised the possibility that influenza vaccines could induce a more broadly protective response, reducing the need for frequent vaccine strain changes. However, interpretation of these observations is hampered by the lack of quantitative characterization of the antibody repertoire. In this study, we used single-cell cloning of influenza HA-specific B cells to assess the diversity and nature of the antibody response to influenza hemagglutinin in mice. Our findings help to put bounds on the

  13. A conserved multi-gene family induces cross-reactive antibodies effective in defense against Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Subhash Singh

    Full Text Available BACKGROUND: Two related merozoite surface proteins, MSP3 and MSP6, have previously been identified as targets of antibody-dependent cellular inhibition (ADCI, a protective mechanism against Plasmodium falciparum malaria. Both MSP3 and MSP6 share a common characteristic small N-terminal signature amino-acid stretch (NLRNA/G, a feature similar to MSP3-like orthologs identified in other human and primate malaria parasites. METHODS/RESULTS: This signature amino-acid sequence led to the identification of eight ORFs contiguously located on P. falciparum chromosome 10. Our subsequent investigations on their expression, localization, sequence conservation, epitope sharing, immunogenicity and the functional role of antibodies in defense are reported here. Six members of P. falciparum MSP3-multigene family share similar sequence organization within their C-terminal regions, are simultaneously expressed as merozoite surface proteins and are highly conserved among parasite isolates. Each of these proteins is a target of naturally occurring antibodies effective at parasite killing in ADCI assays. Moreover, both naturally occurring antibodies and those generated by immunization display cross-reactivity with other members of the family and exhibit varied binding avidities. CONCLUSIONS/SIGNIFICANCE: The unusual characteristics of the MSP3 multi-gene family lead us to hypothesize that the simultaneous expression of targets eliciting cross-reactive antibody responses capable of controlling parasite densities could represent an immune process selected through evolution to maintain homeostasis between P. falciparum and human hosts; a process that allows the continuous transmission of the parasite without killing the host. Our observations also have practical consequences for vaccine development by suggesting MSP3 vaccine efficacy might be improved when combined with the various C-terminus regions of the MSP3 family members to generate a wider range of antibodies

  14. Plant antibodies for immunotherapy.

    Science.gov (United States)

    Ma, J K; Hein, M B

    1995-01-01

    The original report of Hiatt (1989) initiated a wave of excitement at the realization that a complex mammalian protein such as immunoglobulin could be assembled within a plant cell. The general reaction was one of amazement, but interest in exploiting the possibilities arising from the discovery, for example to make antibodies of therapeutic value, has taken a considerable time to develop. In the meantime, other recombinant expression systems and traditional cell culture techniques have advanced and overcome some of their problems, particularly those associated with yields. Plants, however, still offer unique advantages, especially in their ability to match the protein assembly capabilities of mammalian cells (as demonstrated by the assembly of SIgA molecules), as well as to provide antibodies in bulk at low cost. In addition, the area of "immunization" of plants holds great promise and will surely be a field of enormous growth for the future. PMID:7480334

  15. Recent H3N2 Viruses Have Evolved Specificity for Extended, Branched Human-type Receptors, Conferring Potential for Increased Avidity.

    Science.gov (United States)

    Peng, Wenjie; de Vries, Robert P; Grant, Oliver C; Thompson, Andrew J; McBride, Ryan; Tsogtbaatar, Buyankhishig; Lee, Peter S; Razi, Nahid; Wilson, Ian A; Woods, Robert J; Paulson, James C

    2017-01-11

    Human and avian influenza viruses recognize different sialic acid-containing receptors, referred to as human-type (NeuAcα2-6Gal) and avian-type (NeuAcα2-3Gal), respectively. This presents a species barrier for aerosol droplet transmission of avian viruses in humans and ferrets. Recent reports have suggested that current human H3N2 viruses no longer have strict specificity toward human-type receptors. Using an influenza receptor glycan microarray with extended airway glycans, we find that H3N2 viruses have in fact maintained human-type specificity, but they have evolved preference for a subset of receptors comprising branched glycans with extended poly-N-acetyl-lactosamine (poly-LacNAc) chains, a specificity shared with the 2009 pandemic H1N1 (Cal/04) hemagglutinin. Lipid-linked versions of extended sialoside receptors can restore susceptibility of sialidase-treated MDCK cells to infection by both recent (A/Victoria/361/11) and historical (A/Hong Kong/8/1968) H3N2 viruses. Remarkably, these human-type receptors with elongated branches have the potential to increase avidity by simultaneously binding to two subunits of a single hemagglutinin trimer. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Use of an in vivo FTA assay to assess the magnitude, functional avidity and epitope variant cross-reactivity of T cell responses following HIV-1 recombinant poxvirus vaccination.

    Directory of Open Access Journals (Sweden)

    Danushka K Wijesundara

    Full Text Available Qualitative characteristics of cytotoxic CD8+ T cells (CTLs are important in measuring the effectiveness of CTLs in controlling HIV-1 infections. Indeed, in recent studies patients who are naturally resistant to HIV-1 infections have been shown to possess CTLs that are of high functional avidity and have a high capacity to recognize HIV epitope variants, when compared to HIV-1 infection progressors. When developing efficacious vaccines, assays that can effectively measure CTL quality specifically in vivo are becoming increasingly important. Here we report the use of a recently developed high-throughput multi-parameter technique, known as the fluorescent target array (FTA assay, to simultaneously measure CTL killing magnitude, functional avidity and epitope variant cross-reactivity in real time in vivo. In the current study we have applied the FTA assay as a screening tool to assess a large cohort of over 20 different HIV-1 poxvirus vaccination strategies in mice. This screen revealed that heterologous poxvirus prime-boost vaccination regimes (i.e., recombinant fowlpox (FPV-HIV prime followed by a recombinant vaccinia virus (VV-HIV booster were the most effective in generating high quality CTL responses in vivo. In conclusion, we have demonstrated how the FTA assay can be utilized as a cost effective screening tool (by reducing the required number of animals by >100 fold, to evaluate a large range of HIV-1 vaccination strategies in terms of CTL avidity and variant cross-reactivity in an in vivo setting.

  17. Conformational Masking and Receptor-Dependent Unmasking of Highly Conserved Env Epitopes Recognized by Non-Neutralizing Antibodies That Mediate Potent ADCC against HIV-1

    Directory of Open Access Journals (Sweden)

    George K. Lewis

    2015-09-01

    Full Text Available The mechanism of antibody-mediated protection is a major focus of HIV-1 vaccine development and a significant issue in the control of viremia. Virus neutralization, Fc-mediated effector function, or both, are major mechanisms of antibody-mediated protection against HIV-1, although other mechanisms, such as virus aggregation, are known. The interplay between virus neutralization and Fc-mediated effector function in protection against HIV-1 is complex and only partially understood. Passive immunization studies using potent broadly neutralizing antibodies (bnAbs show that both neutralization and Fc-mediated effector function provides the widest dynamic range of protection; however, a vaccine to elicit these responses remains elusive. By contrast, active immunization studies in both humans and non-human primates using HIV-1 vaccine candidates suggest that weakly neutralizing or non-neutralizing antibodies can protect by Fc-mediated effector function, albeit with a much lower dynamic range seen for passive immunization with bnAbs. HIV-1 has evolved mechanisms to evade each type of antibody-mediated protection that must be countered by a successful AIDS vaccine. Overcoming the hurdles required to elicit bnAbs has become a major focus of HIV-1 vaccine development. Here, we discuss a less studied problem, the structural basis of protection (and its evasion by antibodies that protect only by potent Fc-mediated effector function.

  18. Receptor mimicry by antibody F045–092 facilitates universal binding to the H3 subtype of influenza virus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Peter S.; Ohshima, Nobuko; Stanfield, Robyn L.; Yu, Wenli; Iba, Yoshitaka; Okuno, Yoshinobu; Kurosawa, Yoshikazu; Wilson, Ian A.

    2014-04-10

    Influenza viruses present a significant health challenge each year, as in the H3N2 epidemic of 2012–2013. Here we describe an antibody, F045–092, that possesses broadly neutralizing activity against the entire H3 subtype and accommodates the natural variation and additional glycosylation in all strains tested from 1963 to 2011. Crystal structures of F045–092 in complex with HAs from 1975 and 2011 H3N2 viruses reveal the structural basis for its neutralization breadth through insertion of its 23-residue HCDR3 into the receptor-binding site that involves striking receptor mimicry. F045–092 extends its recognition to divergent subtypes, including H1, H2 and H13, using the enhanced avidity of its IgG to overcome lower-affinity Fab binding, as observed with other antibodies that target the receptor-binding site. This unprecedented level of antibody cross-reactivity against the H3 subtype can potentially inform on development of a pan-H3 vaccine or small-molecule therapeutics.

  19. Bivalent Llama Single-Domain Antibody Fragments against Tumor Necrosis Factor Have Picomolar Potencies due to Intramolecular Interactions

    Directory of Open Access Journals (Sweden)

    Els Beirnaert

    2017-07-01

    Full Text Available The activity of tumor necrosis factor (TNF, a cytokine involved in inflammatory pathologies, can be inhibited by antibodies or trap molecules. Herein, llama-derived variable heavy-chain domains of heavy-chain antibody (VHH, also called Nanobodies™ were generated for the engineering of bivalent constructs, which antagonize the binding of TNF to its receptors with picomolar potencies. Three monomeric VHHs (VHH#1, VHH#2, and VHH#3 were characterized in detail and found to bind TNF with sub-nanomolar affinities. The crystal structures of the TNF–VHH complexes demonstrate that VHH#1 and VHH#2 share the same epitope, at the center of the interaction area of TNF with its TNFRs, while VHH#3 binds to a different, but partially overlapping epitope. These structures rationalize our results obtained with bivalent constructs in which two VHHs were coupled via linkers of different lengths. Contrary to conventional antibodies, these bivalent Nanobody™ constructs can bind to a single trimeric TNF, thus binding with avidity and blocking two of the three receptor binding sites in the cytokine. The different mode of binding to antigen and the engineering into bivalent constructs supports the design of highly potent VHH-based therapeutic entities.

  20. Structure and stability of the non-covalent swapped dimer of bovine seminal ribonuclease: an enzyme tailored to evade ribonuclease protein inhibitor.

    Science.gov (United States)

    Sica, Filomena; Di Fiore, Anna; Merlino, Antonello; Mazzarella, Lelio

    2004-08-27

    A growing number of pancreatic-type ribonucleases (RNases) present cytotoxic activity against malignant cells. The cytoxicity of these enzymes is related to their resistance to the ribonuclease protein inhibitor (RI). In particular, bovine seminal ribonuclease (BS-RNase) is toxic to tumor cells both in vitro and in vivo. BS-RNase is a covalent dimer with two intersubunit disulfide bridges between Cys(31) of one chain and Cys(32) of the second and vice versa. The native enzyme is an equilibrium mixture of two isomers, MxM and M=M. In the former the two subunits swap their N-terminal helices. The cytotoxic action is a peculiar property of MxM. In the reducing environment of cytosol, M=M dissociates into monomers, which are strongly inhibited by RI, whereas MxM remains as a non-covalent dimer (NCD), which evades RI. We have solved the crystal structure of NCD, carboxyamidomethylated at residues Cys(31) and Cys(32) (NCD-CAM), in a complex with 2'-deoxycitidylyl(3'-5')-2'-deoxyadenosine. The molecule reveals a quaternary structural organization much closer to MxM than to other N-terminal-swapped non-covalent dimeric forms of RNases. Model building of the complexes between these non-covalent dimers and RI reveals that NCD-CAM is the only dimer equipped with a quaternary organization capable of interfering seriously with the binding of the inhibitor. Moreover, a detailed comparative structural analysis of the dimers has highlighted the residues, which are mostly important in driving the quaternary structure toward that found in NCD-CAM.

  1. Hepatitis C virus (HCV evades NKG2D-dependent NK cell responses through NS5A-mediated imbalance of inflammatory cytokines.

    Directory of Open Access Journals (Sweden)

    Damien Sène

    Full Text Available Understanding how hepatitis C virus (HCV induces and circumvents the host's natural killer (NK cell-mediated immunity is of critical importance in efforts to design effective therapeutics. We report here the decreased expression of the NKG2D activating receptor as a novel strategy adopted by HCV to evade NK-cell mediated responses. We show that chronic HCV infection is associated with expression of ligands for NKG2D, the MHC class I-related Chain (MIC molecules, on hepatocytes. However, NKG2D expression is downmodulated on circulating NK cells, and consequently NK cell-mediated cytotoxic capacity and interferon-γ production are impaired. Using an endotoxin-free recombinant NS5A protein, we show that NS5A stimulation of monocytes through Toll-like Receptor 4 (TLR4 promotes p38- and PI3 kinase-dependent IL-10 production, while inhibiting IL-12 production. In turn, IL-10 triggers secretion of TGFβ which downmodulates NKG2D expression on NK cells, leading to their impaired effector functions. Moreover, culture supernatants of HCV JFH1 replicating Huh-7.5.1 cells reproduce the effect of recombinant NS5A on NKG2D downmodulation. Exogenous IL-15 can antagonize the TGFβ effect and restore normal NKG2D expression on NK cells. We conclude that NKG2D-dependent NK cell functions are modulated during chronic HCV infection, and demonstrate that this alteration can be prevented by exogenous IL-15, which could represent a meaningful adjuvant for therapeutic intervention.

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

    OpenAIRE

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

    1984-01-01

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

  3. Human antibody technology and the development of antibodies against cytomegalovirus.

    Science.gov (United States)

    Ohlin, Mats; Söderberg-Nauclér, Cecilia

    2015-10-01

    Cytomegalovirus (CMV) is a virus that causes chronic infections in a large set of the population. It may cause severe disease in immunocompromised individuals, is linked to immunosenescence and implied to play an important role in the pathogenesis of cardiovascular diseases and cancer. Modulation of the immune system's abilities to manage the virus represent a highly viable therapeutic option and passive immunotherapy with polyclonal antibody preparations is already in clinical use. Defined monoclonal antibodies offer many advantages over polyclonal antibodies purified from serum. Human CMV-specific monoclonal antibodies have consequently been thoroughly investigated with respect to their potential in the treatment of diseases caused by CMV. Recent advances in human antibody technology have substantially expanded the breadth of antibodies for such applications. This review summarizes the fundamental basis for treating CMV disease by use of antibodies, the basic technologies to be used to develop such antibodies, and relevant human antibody specificities available to target this virus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. How antibodies use complement to regulate antibody responses.

    Science.gov (United States)

    Sörman, Anna; Zhang, Lu; Ding, Zhoujie; Heyman, Birgitta

    2014-10-01

    Antibodies, forming immune complexes with their specific antigen, can cause complete suppression or several 100-fold enhancement of the antibody response. Immune complexes containing IgG and IgM may activate complement and in such situations also complement components will be part of the immune complex. Here, we review experimental data on how antibodies via the complement system upregulate specific antibody responses. Current data suggest that murine IgG1, IgG2a, and IgG2b upregulate antibody responses primarily via Fc-receptors and not via complement. In contrast, IgM and IgG3 act via complement and require the presence of complement receptors 1 and 2 (CR1/2) expressed on both B cells and follicular dendritic cells. Complement plays a crucial role for antibody responses not only to antigen complexed to antibodies, but also to antigen administered alone. Lack of C1q, but not of Factor B or MBL, severely impairs antibody responses suggesting involvement of the classical pathway. In spite of this, normal antibody responses are found in mice lacking several activators of the classical pathway (complement activating natural IgM, serum amyloid P component (SAP), specific intracellular adhesion molecule-grabbing non-integrin R1 (SIGN-R1) or C-reactive protein. Possible explanations to these observations will be discussed. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Genetically engineered multivalent single chain antibody constructs for cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Surinder Batra, Ph D

    2006-02-27

    its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more

  6. Evading the joint decision trap

    DEFF Research Database (Denmark)

    Stenbæk, Jørgen; Jensen, Mads Christian Dagnis

    2016-01-01

    is applied, including the concept of the joint-decision trap. The paper finds that the outcome was made possible by compensating the member states that were worst affected by the policy changes. A coalition of net contributors, centered on Germany and the United Kingdom, was influential regarding the overall...

  7. Hõimupäevad 2004

    Index Scriptorium Estoniae

    2004-01-01

    Näitusi: Tallinna Pedagoogikaülikooli Akadeemilises Raamatukogus Eesti Kunstiakadeemia ekspeditsiooninäitus "Seto' täämbä" 12. X-13. XI. Obinitsas kontor-galeriis "Hal'as kunn" Vladimir Nagovitsõni näitus "Põhja-Udmurdi jumalad" 12. X-1. XI. E. Vilde ja A. H. Tammsaare memoriaalmuuseumis Valt Ernshtreidi ja Zane Graudina fotonäitus "Inter/rational" 13. X-1. XI. Eesti Rahva Muuseumi Näitustemajas näitus "Pruudi-vara" (kuraator Svetlana Karm, kujundaja Jane Liiv)15. X-31. XII

  8. Tetranychus evansi evades plant defence

    OpenAIRE

    Ataíde, Lívia Maria Silva

    2013-01-01

    Spider mites are known to induce or suppress plant defences. For instance, most strains of Tetranychus urticae induce plant defences regulated by jasmonic acid (JA) and salicylic acid (SA) pathways and this response has been correlated with a reduction in their reproductive performance on tomato plants. In contrast, the red spider mite Tetranychus evansi suppresses the JA and SA defences and both spider mite species were found to perform much better on tomato leaves that were previously attac...

  9. Monoclonal antibodies to Pneumocystis carinii

    DEFF Research Database (Denmark)

    Kovacs, J A; Halpern, J L; Lundgren, B

    1989-01-01

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

  10. Stromal cells from human long-term marrow cultures, but not cultured marrow fibroblasts, phagocytose horse serum constituents: studies with a monoclonal antibody that reacts with a species-specific epitope common to multiple horse serum proteins.

    Science.gov (United States)

    Charbord, P; Tippens, D; Wight, T S; Gown, A M; Singer, J W

    1987-01-01

    This report describes an IgG1 mouse monoclonal antibody derived after immunization of mice with washed stromal cells from human, long-term bone marrow cultures. The antigen recognized by the antibody (BMS-1) is a carbohydrate-containing prosthetic group that is common to and specific for multiple horse serum proteins. These proteins are avidly ingested by stromal cells and concentrated in endocytic vesicles. Cultured smooth muscle cells took up the horse proteins in a similar manner to marrow stromal cells while cultured marrow fibroblasts, endothelial cells, and hepatoma cells did not. These data indicate that marrow stromal cells specifically accumulate horse serum proteins which might partially explain the horse serum requirement for long-term marrow culture maintenance. The data also suggest further similarities between marrow stromal and smooth muscle cells and additional differences between marrow fibroblasts and marrow stromal cells.

  11. Gu-4 suppresses affinity and avidity modulation of CD11b and improves the outcome of mice with endotoxemia and sepsis.

    Directory of Open Access Journals (Sweden)

    TingTing Yan

    Full Text Available BACKGROUND: Systemic leukocyte activation and disseminated leukocyte adhesion will impair the microcirculation and cause severe decrements in tissue perfusion and organ function in the process of severe sepsis. Gu-4, a lactosyl derivative, could selectively target CD11b to exert therapeutic effect in a rat model of severe burn shock. Here, we addressed whether Gu-4 could render protective effects on septic animals. METHODOLOGY/PRINCIPAL FINDINGS: On a murine model of endotoxemia induced by lipopolysaccharide (LPS, we found that the median effective dose (ED50 of Gu-4 was 0.929 mg/kg. In vivo treatment of Gu-4 after LPS challenge prominently attenuated LPS-induced lung injury and decreased lactic acid level in lung tissue. Using the ED50 of Gu-4, we also demonstrated that Gu-4 treatment significantly improved the survival rate of animals underwent sepsis induced by cecal ligation and puncture. By adhesion and transwell migration assays, we found that Gu-4 treatment inhibited the adhesion and transendothelial migration of LPS-stimulated THP-1 cells. By flow cytometry and microscopy, we demonstrated that Gu-4 treatment inhibited the exposure of active I-domain and the cluster formation of CD11b on the LPS-stimulated polymorphonuclear leukocytes. Western blot analyses further revealed that Gu-4 treatment markedly inhibited the activation of spleen tyrosine kinase in LPS-stimulated THP-1 cells. CONCLUSIONS/SIGNIFICANCE: Gu-4 improves the survival of mice underwent endotoxemia and sepsis, our in vitro investigations indicate that the possible underlying mechanism might involve the modulations of the affinity and avidity of CD11b on the leukocyte. Our findings shed light on the potential use of Gu-4, an interacting compound to CD11b, in the treatment of sepsis and septic shock.

  12. Antiviral Functions of Human Immunodeficiency Virus Type 1 (HIV-1)-Specific IgG Antibodies: Effects of Antiretroviral Therapy and Implications for Therapeutic HIV-1 Vaccine Design.

    Science.gov (United States)

    French, Martyn A; Tjiam, M Christian; Abudulai, Laila N; Fernandez, Sonia

    2017-01-01

    Contemporary antiretroviral therapy (ART) is effective and tolerable for long periods of time but cannot eradicate human immunodeficiency virus type 1 (HIV-1) infection by either elimination of viral reservoirs or enhancement of HIV-1-specific immune responses. Boosting "protective" HIV-1-specific immune responses by active or passive immunization will therefore be necessary to control or eradicate HIV-1 infection and is currently the topic of intense investigation. Recently reported studies conducted in HIV patients and non-human primate (NHP) models of HIV-1 infection suggest that HIV-1-specific IgG antibody responses may contribute to the control of HIV-1 infection. However, production of IgG antibodies with virus neutralizing activity by vaccination remains problematic and while vaccine-induced natural killer cell-activating IgG antibodies have been shown to prevent the acquisition of HIV-1 infection, they may not be sufficient to control or eradicate established HIV-1 infection. It is, therefore, important to consider other functional characteristics of IgG antibody responses. IgG antibodies to viruses also mediate opsonophagocytic antibody responses against virions and capsids that enhance the function of phagocytic cells playing critical roles in antiviral immune responses, particularly conventional dendritic cells and plasmacytoid dendritic cells. Emerging evidence suggests that these antibody functions might contribute to the control of HIV-1 infection. In addition, IgG antibodies contribute to the intracellular degradation of viruses via binding to the cytosolic fragment crystallizable (Fc) receptor tripartite motif containing-21 (TRIM21). The functional activity of an IgG antibody response is influenced by the IgG subclass content, which affects binding to antigens and to Fcγ receptors on phagocytic cells and to TRIM21. The IgG subclass content and avidity of IgG antibodies is determined by germinal center (GC) reactions in follicles of lymphoid tissue

  13. The future of monoclonal antibody technology

    OpenAIRE

    Zider, Alexander; Drakeman, Donald L

    2010-01-01

    With the rapid growth of monoclonal antibody-based products, new technologies have emerged for creating modified forms of antibodies, including fragments, conjugates and multi-specific antibodies. We created a database of 450 therapeutic antibodies in development to determine which technologies and indications will constitute the “next generation” of antibody products. We conclude that the antibodies of the future will closely resemble the antibodies that have already been approved for commer...

  14. An indirect enzyme-linked immunosorbent assay for the identification of antibodies to Senecavirus A in swine.

    Science.gov (United States)

    Dvorak, Cheryl M T; Akkutay-Yoldar, Zeynep; Stone, Suzanne R; Tousignant, Steven J P; Vannucci, Fabio A; Murtaugh, Michael P

    2017-02-15

    Senecavirus A (SVA), a member of the family Picornaviridae, genus Senecavirus, is a recently identified single-stranded RNA virus closely related to members of the Cardiovirus genus. SVA was originally identified as a cell culture contaminant and was not associated with disease until 2007 when it was first observed in pigs with Idiopathic Vesicular Disease (IVD). Vesicular disease is sporadically observed in swine, is not debilitating, but is significant due to its resemblance to foreign animal diseases, such as foot-and-mouth disease (FMD), whose presence would be economically devastating to the United States. IVD disrupts swine production until foreign animal diseases can be ruled out. Identification and characterization of SVA as a cause of IVD will help to quickly rule out infection by foreign animal diseases. We have developed and characterized an indirect ELISA assay to specifically identify serum antibodies to SVA. Viral protein 1, 2 and 3 (VP1, VP2, VP3) were expressed, isolated, and purified from E. coli and used to coat plates for an indirect ELISA. Sera from pigs with and without IVD symptoms as well as a time course following animals from an infected farm, were analyzed to determine the antibody responses to VP1, VP2, and VP3. Antibody responses to VP2 were higher than VP1 and VP3 and showed high affinity binding on an avidity ELISA. ROC analysis of the SVA VP2 ELISA showed a sensitivity of 94.2% and a specificity of 89.7%. Compared to IFA, the quantitative ELISA showed an 89% agreement in negative samples and positive samples from 4-60 days after appearance of clinical signs. Immune sera positive for FMDV, encephalomyocarditis virus, and porcine epidemic diarrhea virus antibodies did not cross-react. A simple ELISA based on detection of antibodies to SVA VP2 will help to differentially diagnose IVD due to SVA and rule out the presence of economically devastating foreign animal diseases.

  15. Discovery of Fully Human Anti-MET Monoclonal Antibodies with Antitumor Activity against Colon Cancer Tumor Models In Vivo

    Directory of Open Access Journals (Sweden)

    Edward Htun van der Horst

    2009-04-01

    Full Text Available The receptor tyrosine kinase MET is a major component controlling the invasive growth program in embryonic development and in invasive malignancies. The discovery of therapeutic antibodies against MET has been difficult, and antibodies that compete with hepatocyte growth factor (HGF act as agonists. By applying phage technology and cell-based panning strategies, we discovered two fully human antibodies against MET (R13 and R28, which synergistically inhibit HGF binding to MET and elicit antibody-dependent cellular cytotoxicity. Cell-based phosphorylation assays demonstrate that R13 and R28 abrogate HGF-induced activation of MET, AKT1, ERK1/2, and HGF-induced migration and proliferation. FACS experiments suggest that the inhibitory effect is mediated by “locking” MET receptor in a state with R13, which then increases avidity of R28 for the extracellular domain of MET, thus blocking HGF binding without activating the receptor. In vivo studies demonstrate that the combination of R13/28 significantly inhibited tumor growth in various colon tumor xenograft models. Inhibition of tumor growth was associated with induction of hypoxia. Global gene expression analysis shows that inhibition of HGF/MET pathway significantly upregulated the tumor suppressors KLF6, CEACAM1, and BMP2, the negative regulator of phosphatidylinositol-3-OH-kinase PIK3IP1, and significantly suppressed SCF and SERPINE2, both enhancers of proliferation and invasiveness. Moreover, in an experimental metastasis model, R13/28 increased survival by preventing the recurrence of otherwise lethal lung metastases. Taken together, these results underscore the utility of a dual-antibody approach for targeting MET and possibly other receptor tyrosine kinases. Our approach could be expanded to drug discovery efforts against other cell surface proteins.

  16. [Local antibody immune responses in influenza patients and persons vaccinated with seasonal, pre-pandemic, and pandemic live attenuated influenza vaccines].

    Science.gov (United States)

    Donina, S A; Petukhova, G D; Koren'kov, D A; Grigor'eva, E P; Kuznetsova, S A; Losev, I V; Rudenko, L G; Naĭkhin, A N

    2013-01-01

    Mucosal immunity is one of the most important factors of human anti-influenza defense. The data about local immune responses in influenza A (H3N2) patients and in persons vaccinated within 2000-2009 with different seasonal LAIVs, A (H1N1)pdm2009 LAIV, and A (H5N2) LAIV are discussed. The influenza infection resulted in the larger quantities of local IgA and IgG conversions than seasonal LAIV vaccination. 56% of young (18-21 y.o.) persons had high titers (> or = 1:64) of IgA to A (H1N1)pdm2009 virus before its circulation. 19% of persons had anti A (H5N2) IgA before vaccination. Two-fold vaccination with A (H1N1) pdm2009 and A (H5N2) LAIVs resulted in local antibody conversions in 54% and 27% of volunteers, respectively. Both these vaccines increased local IgA avidity. The number of antibody conversions after vaccination with seasonal LAIVs was in inverse dependence on their titers before vaccination. These results make it possible to conclude that the intensity of local antibody immune response to any LAIV depends on the state of local immunological memory, particularly on the presence of the crossreactive antibody-secreting B cells.

  17. Antibodies against antibodies: immunogenicity of adalimumab as a model

    NARCIS (Netherlands)

    van Schouwenburg, P.A.

    2012-01-01

    Upon repeated adalimumab exposure part of the patients start to produce ADA. The antibody response is polyclonal and consists mainly of antibodies of IgG1 and IgG4 isotype. In the majority of ADA positive patients ADA are already produced within the first 28 weeks of treatment and in part of the

  18. Theranostics Using Antibodies and Antibody-Related Therapeutics

    NARCIS (Netherlands)

    Moek, Kirsten L; Giesen, Danique; Kok, Iris C; de Groot, Derk Jan A; Jalving, Mathilde; Fehrmann, Rudolf S N; Lub-de Hooge, Marjolijn N; Brouwers, Adrienne H; de Vries, Elisabeth G E

    In theranostics, radiolabeled compounds are used to determine a treatment strategy by combining therapeutics and diagnostics in the same agent. Monoclonal antibodies (mAbs) and antibody-related therapeutics represent a rapidly expanding group of cancer medicines. Theranostic approaches using these

  19. Estimating the probability of polyreactive antibodies 4E10 and 2F5 disabling a gp41 trimer after T cell-HIV adhesion.

    Directory of Open Access Journals (Sweden)

    Bin Hu

    2014-01-01

    Full Text Available A few broadly neutralizing antibodies, isolated from HIV-1 infected individuals, recognize epitopes in the membrane proximal external region (MPER of gp41 that are transiently exposed during viral entry. The best characterized, 4E10 and 2F5, are polyreactive, binding to the viral membrane and their epitopes in the MPER. We present a model to calculate, for any antibody concentration, the probability that during the pre-hairpin intermediate, the transient period when the epitopes are first exposed, a bound antibody will disable a trivalent gp41 before fusion is complete. When 4E10 or 2F5 bind to the MPER, a conformational change is induced that results in a stably bound complex. The model predicts that for these antibodies to be effective at neutralization, the time to disable an epitope must be shorter than the time the antibody remains bound in this conformation, about five minutes or less for 4E10 and 2F5. We investigate the role of avidity in neutralization and show that 2F5 IgG, but not 4E10, is much more effective at neutralization than its Fab fragment. We attribute this to 2F5 interacting more stably than 4E10 with the viral membrane. We use the model to elucidate the parameters that determine the ability of these antibodies to disable epitopes and propose an extension of the model to analyze neutralization data. The extended model predicts the dependencies of IC50 for neutralization on the rate constants that characterize antibody binding, the rate of fusion of gp41, and the number of gp41 bridging the virus and target cell at the start of the pre-hairpin intermediate. Analysis of neutralization experiments indicate that only a small number of gp41 bridges must be disabled to prevent fusion. However, the model cannot determine the exact number from neutralization experiments alone.

  20. High Resolution Mapping of Bactericidal Monoclonal Antibody Binding Epitopes on Staphylococcus aureus Antigen MntC.

    Directory of Open Access Journals (Sweden)

    Alexey V Gribenko

    2016-09-01

    Full Text Available The Staphylococcus aureus manganese transporter protein MntC is under investigation as a component of a prophylactic S.aureus vaccine. Passive immunization with monoclonal antibodies mAB 305-78-7 and mAB 305-101-8 produced using MntC was shown to significantly reduce S. aureus burden in an infant rat model of infection. Earlier interference mapping suggested that a total of 23 monoclonal antibodies generated against MntC could be subdivided into three interference groups, representing three independent immunogenic regions. In the current work binding epitopes for selected representatives of each of these interference groups (mAB 305-72-5 - group 1, mAB 305-78-7 - group 2, and mAB 305-101-8 - group 3 were mapped using Hydrogen-Deuterium Exchange Mass Spectrometry (DXMS. All of the identified epitopes are discontinuous, with binding surface formed by structural elements that are separated within the primary sequence of the protein but adjacent in the context of the three-dimensional structure. The approach was validated by co-crystallizing the Fab fragment of one of the antibodies (mAB 305-78-7 with MntC and solving the three-dimensional structure of the complex. X-ray results themselves and localization of the mAB 305-78-7 epitope were further validated using antibody binding experiments with MntC variants containing substitutions of key amino acid residues. These results provided insight into the antigenic properties of MntC and how these properties may play a role in protecting the hostagainst S. aureus infection by preventing the capture and transport of Mn2+, a key element that the pathogen uses to evade host immunity.

  1. Trypanosoma cruzi Evades the Complement System as an Efficient Strategy to Survive in the Mammalian Host: The Specific Roles of Host/Parasite Molecules and Trypanosoma cruzi Calreticulin

    Science.gov (United States)

    Ramírez-Toloza, Galia; Ferreira, Arturo

    2017-01-01

    American Trypanosomiasis is an important neglected reemerging tropical parasitism, infecting about 8 million people worldwide. Its agent, Trypanosoma cruzi, exhibits multiple mechanisms to evade the host immune response and infect host cells. An important immune evasion strategy of T. cruzi infective stages is its capacity to inhibit the complement system activation on the parasite surface, avoiding opsonizing, immune stimulating and lytic effects. Epimastigotes, the non-infective form of the parasite, present in triatomine arthropod vectors, are highly susceptible to complement-mediated lysis while trypomastigotes, the infective form, present in host bloodstream, are resistant. Thus T. cruzi susceptibility to complement varies depending on the parasite stage (amastigote, trypomastigotes or epimastigote) and on the T. cruzi strain. To avoid complement-mediated lysis, T. cruzi trypomastigotes express on the parasite surface a variety of complement regulatory proteins, such as glycoprotein 58/68 (gp58/68), T. cruzi complement regulatory protein (TcCRP), trypomastigote decay-accelerating factor (T-DAF), C2 receptor inhibitor trispanning (CRIT) and T. cruzi calreticulin (TcCRT). Alternatively, or concomitantly, the parasite captures components with complement regulatory activity from the host bloodstream, such as factor H (FH) and plasma membrane-derived vesicles (PMVs). All these proteins inhibit different steps of the classical (CP), alternative (AP) or lectin pathways (LP). Thus, TcCRP inhibits the CP C3 convertase assembling, gp58/68 inhibits the AP C3 convertase, T-DAF interferes with the CP and AP convertases assembling, TcCRT inhibits the CP and LP, CRIT confers ability to resist the CP and LP, FH is used by trypomastigotes to inhibit the AP convertases and PMVs inhibit the CP and LP C3 convertases. Many of these proteins have similar molecular inhibitory mechanisms. Our laboratory has contributed to elucidate the role of TcCRT in the host-parasite interplay

  2. Trypanosoma cruzi Evades the Complement System as an Efficient Strategy to Survive in the Mammalian Host: The Specific Roles of Host/Parasite Molecules and Trypanosoma cruzi Calreticulin

    Directory of Open Access Journals (Sweden)

    Galia Ramírez-Toloza

    2017-09-01

    Full Text Available American Trypanosomiasis is an important neglected reemerging tropical parasitism, infecting about 8 million people worldwide. Its agent, Trypanosoma cruzi, exhibits multiple mechanisms to evade the host immune response and infect host cells. An important immune evasion strategy of T. cruzi infective stages is its capacity to inhibit the complement system activation on the parasite surface, avoiding opsonizing, immune stimulating and lytic effects. Epimastigotes, the non-infective form of the parasite, present in triatomine arthropod vectors, are highly susceptible to complement-mediated lysis while trypomastigotes, the infective form, present in host bloodstream, are resistant. Thus T. cruzi susceptibility to complement varies depending on the parasite stage (amastigote, trypomastigotes or epimastigote and on the T. cruzi strain. To avoid complement-mediated lysis, T. cruzi trypomastigotes express on the parasite surface a variety of complement regulatory proteins, such as glycoprotein 58/68 (gp58/68, T. cruzi complement regulatory protein (TcCRP, trypomastigote decay-accelerating factor (T-DAF, C2 receptor inhibitor trispanning (CRIT and T. cruzi calreticulin (TcCRT. Alternatively, or concomitantly, the parasite captures components with complement regulatory activity from the host bloodstream, such as factor H (FH and plasma membrane-derived vesicles (PMVs. All these proteins inhibit different steps of the classical (CP, alternative (AP or lectin pathways (LP. Thus, TcCRP inhibits the CP C3 convertase assembling, gp58/68 inhibits the AP C3 convertase, T-DAF interferes with the CP and AP convertases assembling, TcCRT inhibits the CP and LP, CRIT confers ability to resist the CP and LP, FH is used by trypomastigotes to inhibit the AP convertases and PMVs inhibit the CP and LP C3 convertases. Many of these proteins have similar molecular inhibitory mechanisms. Our laboratory has contributed to elucidate the role of TcCRT in the host

  3. Burkholderia pseudomallei Evades Nramp1 (Slc11a1- and NADPH Oxidase-Mediated Killing in Macrophages and Exhibits Nramp1-Dependent Virulence Gene Expression

    Directory of Open Access Journals (Sweden)

    Veerachat Muangsombut

    2017-08-01

    Full Text Available Bacterial survival in macrophages can be affected by the natural resistance-associated macrophage protein 1 (Nramp1; also known as solute carrier family 11 member a1 or Slc11a1 which localizes to phagosome membranes and transports divalent cations, including iron. Little is known about the role of Nramp1 in Burkholderia infection, in particular whether this differs for pathogenic species like Burkholderia pseudomallei causing melioidosis or non-pathogenic species like Burkholderia thailandensis. Here we show that transfected macrophages stably expressing wild-type Nramp1 (Nramp1+ control the net replication of B. thailandensis, but not B. pseudomallei. Control of B. thailandensis was associated with increased cytokine responses, and could be abrogated by blocking NADPH oxidase-mediated production of reactive oxygen species but not by blocking generation of reactive nitrogen species. The inability of Nramp1+ macrophages to control B. pseudomallei was associated with rapid escape of bacteria from phagosomes, as indicated by decreased co-localization with LAMP1 compared to B. thailandensis. A B. pseudomallei bipB mutant impaired in escape from phagosomes was controlled to a greater extent than the parent strain in Nramp1+ macrophages, but was also attenuated in Nramp1− cells. Consistent with reduced escape from phagosomes, B. thailandensis formed fewer multinucleated giant cells in Nramp1+ macrophages at later time points compared to B. pseudomallei. B. pseudomallei exhibited elevated transcription of virulence-associated genes of Type VI Secretion System cluster 1 (T6SS-1, the Bsa Type III Secretion System (T3SS-3 and the bimA gene required for actin-based motility in Nramp1+ macrophages. Nramp1+ macrophages were found to contain decreased iron levels that may impact on expression of such genes. Our data show that B. pseudomallei is able to evade Nramp1- and NADPH oxidase-mediated killing in macrophages and that expression of virulence

  4. Educational paper: Primary antibody deficiencies

    NARCIS (Netherlands)

    G.J.A. Driessen (Gertjan); M. van der Burg (Mirjam)

    2011-01-01

    textabstractPrimary antibody deficiencies (PADs) are the most common primary immunodeficiencies and are characterized by a defect in the production of normal amounts of antigen-specific antibodies. PADs represent a heterogeneous spectrum of conditions, ranging from often asymptomatic selective IgA

  5. Antibodies and Plasmodium falciparum merozoites

    NARCIS (Netherlands)

    Ramasamy, R; Ramasamy, M; Yasawardena, S

    There is considerable interest in using merozoite proteins in a vaccine against falciparum malaria. Observations that antibodies to merozoite surface proteins block invasion are a basis for optimism. This article draws attention to important and varied aspects of how antibodies to Plasmodium

  6. Red Blood Cell Antibody Identification

    Science.gov (United States)

    ... antibodies may or may not be associated with adverse reactions, and identification of the specific type of RBC ... the only things that can cause a transfusion reaction. The recipient's immune ... or to drugs that the donor may have taken. Rarely, antibodies in the plasma ...

  7. Mercury, eicosapentanoic acid and docosahexaenoic acid demonstrate limited effect on plasma paraoxonase-1 activity and blood pressure among avid seafood consumers in the Long Island Study of Seafood Consumption, NY, USA.

    Science.gov (United States)

    Miller, Charles; Karimi, Roxanne; Zhang, Qiao; Yang, Jie; Meliker, Jaymie

    2017-04-01

    Moderate fish consumption is recommended for prevention of coronary heart disease (CHD) as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have known beneficial effects on risk factors such as reducing blood pressure (BP) and increasing paraoxonase-1 (PON-1) activity. However concomitant methylmercury (MeHg) exposure from fish consumption may mitigate these benefits and the net effect on BP and PON-1 activity has not been extensively studied in western populations consuming diverse seafood types. We studied the correlation between EPA, DHA and Hg levels with BP and PON-1 activity in a population of avid seafood consumers. Two hundred and eighty-eight avid seafood consumers from Long Island, NY had blood samples drawn for total blood mercury (THg), plasma EPA and DHA levels, and plasma PON-1 activity. Average systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were measured. Subjects' mean EPA+DHA was 4.9% total fatty acids, mean THg was 7.6mcg/L. Mean SBP was 122.5mmHg, mean DBP 70.3mmHg, mean PP 52.2mmHg and mean PON-1 activity 421.2U/L. THg was not associated with any of the BP measures in adjusted linear regression models; EPA+DHA was significantly inversely associated with PP (p=0.02). THg was associated with a significant increase in PON-1 activity (p=0.04), while EPA+DHA was associated with a significant decrease in PON-1 activity (p=0.007); although the size of the effects was small. Our findings suggest blood THg and serum DHA+EPA levels have limited relationship to BP and PON-1 activity, and may not be important modulators of these known CHD risk factors in this population of avid seafood consumers. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Serum antibody response to Human papillomavirus (HPV infections detected by a novel ELISA technique based on denatured recombinant HPV16 L1, L2, E4, E6 and E7 proteins

    Directory of Open Access Journals (Sweden)

    Mariani Luciano

    2006-11-01

    Full Text Available Abstract Background Human papillomaviruses (HPVs are the primary etiological agents of cervical cancer and are also involved in the development of other tumours (skin, head and neck. Serological survey of the HPV infections is important to better elucidate their natural history and to disclose antigen determinants useful for vaccine development. At present, the analysis of the HPV-specific antibodies has not diagnostic value for the viral infections, and new approaches are needed to correlate the antibody response to the disease outcome. The aim of this study is to develop a novel ELISA, based on five denatured recombinant HPV16 proteins, to be used for detection HPV-specific antibodies. Methods The HPV16 L1, L2, E4, E6 and E7 genes were cloned in a prokaryotic expression vector and expressed as histidine-tagged proteins. These proteins, in a denatured form, were used in ELISA as coating antigens. Human sera were collected from women with abnormal PAP smear enrolled during an ongoing multicenter HPV-PathogenISS study in Italy, assessing the HPV-related pathogenetic mechanisms of progression of cervical cancer precursor lesions. Negative human sera were collected from patients affected by other infectious agents. All the HPV-positive sera were also subjected to an avidity test to assess the binding strength in the antigen-antibody complexes. Results Most of the sera showed a positive reactivity to the denatured HPV16 proteins: 82% of the sera from HPV16 infected women and 89% of the sera from women infected by other HPV genotypes recognised at least one of the HPV16 proteins. The percentages of samples showing reactivity to L1, L2 and E7 were similar, but only a few serum samples reacted to E6 and E4. Most sera bound the antigens with medium and high avidity index, suggesting specific antigen-antibody reactions. Conclusion This novel ELISA, based on multiple denatured HPV16 antigens, is able to detect antibodies in women infected by HPV16 and it

  9. The necrosis-avid small molecule HQ4-DTPA as a multimodal imaging agent for monitoring radiation therapy-induced tumor cell death.

    Directory of Open Access Journals (Sweden)

    Marieke A. Stammes

    2016-10-01

    Full Text Available Purpose: Most effective antitumor therapies induce tumor cell death. Non-invasive, rapid and accurate quantitative imaging of cell death is essential for monitoring early response to antitumor therapies. To facilitate this, we previously developed a biocompatible necrosis-avid near-infrared fluorescence (NIRF imaging probe, HQ4, which was radiolabelled with 111Indium-chloride (111In-Cl3 via the chelate diethylene triamine pentaacetic acid (DTPA, to enable clinical translation. The aim of the present study was to evaluate the application of HQ4-DTPA for monitoring tumor cell death induced by radiation therapy. Apart from its NIRF and radioactive properties, HQ4-DTPA was also tested as a photoacoustic imaging probe to evaluate its performance as a multimodal contrast agent for superficial and deep tissue imaging.Material/Methods: Radiation-induced tumor cell death was examined in a xenograft mouse model of human breast cancer (MCF7. Tumors were irradiated with three fractions of 9 Gy each. HQ4-DTPA was injected intravenously after the last irradiation, NIRF and photoacoustic imaging of the tumors were performed at 12, 20 and 40 h after injection. Changes in probe accumulation in the tumors were measured in vivo, and ex vivo histological analysis of excised tumors was performed at experimental endpoints. In addition, biodistribution of radiolabeled [111In]DTPA-HQ4 was assessed using hybrid single-photon emission computed tomography-computed tomography (SPECT-CT at the same time points.Results: In vivo NIRF imaging demonstrated a significant difference in probe accumulation between control and irradiated tumors at all time points after injection. A similar trend was observed using in vivo photoacoustic imaging, which was validated by ex vivo tissue fluorescence and photoacoustic imaging. Serial quantitative radioactivity measurements of probe biodistribution further demonstrated increased probe accumulation in irradiated tumors. Conclusion: HQ4-DTPA

  10. Dual testing algorithm of BED-CEIA and AxSYM Avidity Index assays performs best in identifying recent HIV infection in a sample of Rwandan sex workers.

    Directory of Open Access Journals (Sweden)

    Sarah L Braunstein

    Full Text Available BACKGROUND: To assess the performance of BED-CEIA (BED and AxSYM Avidity Index (Ax-AI assays in estimating HIV incidence among female sex workers (FSW in Kigali, Rwanda. METHODOLOGY AND FINDINGS: Eight hundred FSW of unknown HIV status were HIV tested; HIV-positive women had BED and Ax-AI testing at baseline and ≥12 months later to estimate assay false-recent rates (FRR. STARHS-based HIV incidence was estimated using the McWalter/Welte formula, and adjusted with locally derived FRR and CD4 results. HIV incidence and local assay window periods were estimated from a prospective cohort of FSW. At baseline, 190 HIV-positive women were BED and Ax-AI tested; 23 were classified as recent infection (RI. Assay FRR with 95% confidence intervals were: 3.6% (1.2-8.1 (BED; 10.6% (6.1-17.0 (Ax-AI; and 2.1% (0.4-6.1 (BED/Ax-AI combined. After FRR-adjustment, incidence estimates by BED, Ax-AI, and BED/Ax-AI were: 5.5/100 person-years (95% CI 2.2-8.7; 7.7 (3.2-12.3; and 4.4 (1.4-7.3. After CD4-adjustment, BED, Ax-AI, and BED/Ax-AI incidence estimates were: 5.6 (2.6-8.6; 9.7 (5.0-14.4; and 4.7 (2.0-7.5. HIV incidence rates in the first and second 6 months of the cohort were 4.6 (1.6-7.7 and 2.2 (0.1-4.4. CONCLUSIONS: Adjusted incidence estimates by BED/Ax-AI combined were similar to incidence in the first 6 months of the cohort. Furthermore, false-recent rate on the combined BED/Ax-AI algorithm was low and substantially lower than for either assay alone. Improved assay specificity with time since seroconversion suggests that specificity would be higher in population-based testing where more individuals have long-term infection.

  11. The Necrosis-Avid Small Molecule HQ4-DTPA as a Multimodal Imaging Agent for Monitoring Radiation Therapy-Induced Tumor Cell Death.

    Science.gov (United States)

    Stammes, Marieke A; Maeda, Azusa; Bu, Jiachuan; Scollard, Deborah A; Kulbatski, Iris; Medeiros, Philip J; Sinisi, Riccardo; Dubikovskaya, Elena A; Snoeks, Thomas J A; van Beek, Ermond R; Chan, Alan B; Löwik, Clemens W G M; DaCosta, Ralph S

    2016-01-01

    Most effective antitumor therapies induce tumor cell death. Non-invasive, rapid and accurate quantitative imaging of cell death is essential for monitoring early response to antitumor therapies. To facilitate this, we previously developed a biocompatible necrosis-avid near-infrared fluorescence (NIRF) imaging probe, HQ4, which was radiolabeled with 111Indium-chloride (111In-Cl3) via the chelate diethylene triamine pentaacetic acid (DTPA), to enable clinical translation. The aim of the present study was to evaluate the application of HQ4-DTPA for monitoring tumor cell death induced by radiation therapy. Apart from its NIRF and radioactive properties, HQ4-DTPA was also tested as a photoacoustic imaging probe to evaluate its performance as a multimodal contrast agent for superficial and deep tissue imaging. Radiation-induced tumor cell death was examined in a xenograft mouse model of human breast cancer (MCF-7). Tumors were irradiated with three fractions of 9 Gy each. HQ4-DTPA was injected intravenously after the last irradiation, NIRF and photoacoustic imaging of the tumors were performed at 12, 20, and 40 h after injection. Changes in probe accumulation in the tumors were measured in vivo, and ex vivo histological analysis of excised tumors was performed at experimental endpoints. In addition, biodistribution of radiolabeled [111In]DTPA-HQ4 was assessed using hybrid single-photon emission computed tomography-computed tomography (SPECT-CT) at the same time points. In vivo NIRF imaging demonstrated a significant difference in probe accumulation between control and irradiated tumors at all time points after injection. A similar trend was observed using in vivo photoacoustic imaging, which was validated by ex vivo tissue fluorescence and photoacoustic imaging. Serial quantitative radioactivity measurements of probe biodistribution further demonstrated increased probe accumulation in irradiated tumors. HQ4-DTPA has high specificity for dead cells in vivo

  12. Repeated Vaccination of Cows with HIV Env gp140 during Subsequent Pregnancies Elicits and Sustains an Enduring Strong Env-Binding and Neutralising Antibody Response.

    Directory of Open Access Journals (Sweden)

    Behnaz Heydarchi

    Full Text Available An important feature of a potential vaccine against HIV is the production of broadly neutralising antibodies (BrNAbs capable of potentially blocking infectivity of a diverse array of HIV strains. BrNAbs naturally arise in some HIV infected individuals after several years of infection and their serum IgG can neutralise various HIV strains across different subtypes. We previously showed that vaccination of cows with HIV gp140 AD8 trimers resulted in a high titre of serum IgG against HIV envelope (Env that had strong BrNAb activity. These polyclonal BrNAbs concentrated into the colostrum during the late stage of pregnancy and can be harvested in vast quantities immediately after calving. In this study, we investigated the effect of prolonged HIV gp140 vaccination on bovine colostrum IgG HIV Env-binding and BrNAb activity over subsequent pregnancies. Repeated immunisation led to a maintained high titre of HIV Env specific IgG in the colostrum batches, but this did not increase through repeated cycles. Colostrum IgG from all batches also strongly competed with sCD4 binding to gp140 Env trimer and with human-derived monoclonal VRC01 and b12 BrNAbs that bind the CD4 binding site (CD4bs. Furthermore, competition neutralisation assays using RSC3 Env gp120 protein core and a derivative CD4bs mutant, RSC3 Δ371I/P363N, showed that CD4bs neutralising antibodies contribute to the neutralising activity of all batches of purified bovine colostrum IgG. This result indicates that the high IgG titre/avidity of anti-CD4bs antibodies with BrNAb activity was achieved during the first year of vaccination and was sustained throughout the years of repeated vaccinations in the cow tested. Although IgG of subsequent colostrum batches may have a higher avidity towards the CD4bs, the overall breadth in neutralisation was not enhanced. This implies that the boosting vaccinations over 4 years elicited a polyclonal antibody response that maintained the proportion of both

  13. AVID: Automatic Visualization Interface Designer

    National Research Council Canada - National Science Library

    Chuah, Mei

    2000-01-01

    .... Automatic generation offers great flexibility in performing data and information analysis tasks, because new designs are generated on a case by case basis to suit current and changing future needs...

  14. Production systems for recombinant antibodies.

    Science.gov (United States)

    Schirrmann, Thomas; Al-Halabi, Laila; Dübel, Stefan; Hust, Michael

    2008-05-01

    Recombinant antibodies are the fastest growing class of therapeutic proteins. Furthermore, antibodies are key detection reagents in research and diagnostics. The increasing demand for antibodies with regards to amount and quality resulted in the development of a variety of recombinant production systems employing gram-negative and gram-positive bacteria, yeast and filamentous fungi, insect cell lines as well as mammalian cell lines. More recently, antibodies were also successfully produced in transgenic plants and animals. Currently, the production of recombinant antibodies for therapy is performed in mammalian cell lines to reduce the risk of immunogenicity caused by non-human post-translational modifications, in particular glycosylation. However, novel strategies already allow human-like glycosylation patterns in yeast, insect cell lines and transgenic plants. Furthermore, therapeutic strategies not requiring glycosylation of the Fc portion have been conceived, most prominently using bispecific antibodies or scFv fusion proteins, which can be produced in bacteria. Here, we review all current antibody production systems considering their advantages and limitations with respect to intended applications.

  15. Gestational toxoplasmosis in Paraná State, Brazil: prevalence of IgG antibodies and associated risk factors

    Directory of Open Access Journals (Sweden)

    Fabiana Maria Ruiz Lopes-Mori

    Full Text Available The aim of the present study was to verify the association between seropositivity for IgG anti-Toxoplasma gondii antibodies and social, economic and environmental variables of pregnant women attending the public health centers of Paraná, Brazil. From January 2007 to July 2010, 2226 pregnant women were interviewed and detection of anti-T. gondii specific IgG and IgM antibodies was performed by chemiluminescence test. Seropositivity for anti-T. gondii IgG was observed in 1151 (51.7% pregnant women, 29 of which (1.3% presented IgM reagent with IgG of high avidity. The variables associated with the presence of IgG were residency in the rural area, more than one pregnancy, less than or equal to eight years schooling, low per capita income, age group, raw or poorly cooked meat ingestion, and contact with the soil. There was neither association with raw fruit and vegetable ingestion nor with the presence of cats in the residencies.

  16. Precipitating antibodies in mycoplasma infection.

    Science.gov (United States)

    Menonna, J; Chmel, H; Menegus, M; Dowling, P; Cook, S

    1977-01-01

    The effectiveness of counterimmunoelectrophoresis (CIEP) for detecting human precipitating antibodies to mcyoplasma antigen was compared with the conventional complement fixation (CF) method in a double-blind experiment. Fifty-one sera from patients suspected of having acute mycoplasma infection were tested by both techniques. Dense precipitin lines to mycoplasma antigen developed in 28 sera with CIEP. Twenty-six of 28 had elevated CF titers to this antigen. No precipitin bands were observed in sera with low antibody titers to mycoplasma. These findings indicate that the CIEP test is a specific method for reliably detecting elevated serum CF antibody levels in patients with acute or recent mycoplasma infection. PMID:328527

  17. Applying antibody-sensitive hypervariable region 1-deleted hepatitis C virus to the study of escape pathways of neutralizing human monoclonal antibody AR5A

    Science.gov (United States)

    Velázquez-Moctezuma, Rodrigo; Bukh, Jens

    2017-01-01

    Hepatitis C virus (HCV) is a major cause of end-stage liver diseases. With 3–4 million new HCV infections yearly, a vaccine is urgently needed. A better understanding of virus escape from neutralizing antibodies and their corresponding epitopes are important for this effort. However, for viral isolates with high antibody resistance, or antibodies with moderate potency, it remains challenging to induce escape mutations in vitro. Here, as proof-of-concept, we used antibody-sensitive HVR1-deleted (ΔHVR1) viruses to generate escape mutants for a human monoclonal antibody, AR5A, targeting a rare cross-genotype conserved epitope. By analyzing the genotype 1a envelope proteins (E1/E2) of recovered Core-NS2 recombinant H77/JFH1ΔHVR1 and performing reverse genetic studies we found that resistance to AR5A was caused by substitution L665W, also conferring resistance to the parental H77/JFH1. The mutation did not induce viral fitness loss, but abrogated AR5A binding to HCV particles and intracellular E1/E2 complexes. Culturing J6/JFH1ΔHVR1 (genotype 2a), for which fitness was decreased by L665W, with AR5A generated AR5A-resistant viruses with the substitutions I345V, L665S, and S680T, which we introduced into J6/JFH1 and J6/JFH1ΔHVR1. I345V increased fitness but had no effect on AR5A resistance. L665S impaired fitness and decreased AR5A sensitivity, while S680T combined with L665S compensated for fitness loss and decreased AR5A sensitivity even further. Interestingly, S680T alone had no fitness effect but sensitized the virus to AR5A. Of note, H77/JFH1L665S was non-viable. The resistance mutations did not affect cell-to-cell spread or E1/E2 interactions. Finally, introducing L665W, identified in genotype 1, into genotypes 2–6 parental and HVR1-deleted variants (not available for genotype 4a) we observed diverse effects on viral fitness and a universally pronounced reduction in AR5A sensitivity. Thus, we were able to take advantage of the neutralization-sensitive HVR1

  18. What Is Antiphospholipid Antibody Syndrome?

    Science.gov (United States)

    ... specialize in treating these types of disorders. Medical History Some people have APS antibodies but no signs ... warfarin starts to work, the heparin is stopped. Aspirin also thins the blood and helps prevent blood ...

  19. Antisperm antibodies and fertility association.

    Science.gov (United States)

    Restrepo, B; Cardona-Maya, W

    2013-10-01

    To evaluate the relation between antisperm antibodies (ASA) and human fertility by reviewing the scientific literature of the last 45 years. We carried out a review of scientific literature about antisperm antibodies and infertility published in spanish or english in databases as Pubmed, Medline, Scielo, some books and another gray literature include information related to this review and that is published in the last 45 years. Infertile couples suffer infertility by immunological mechanisms mainly by the presence of antisperm antibodies ASA in blood, semen or cervicovaginal secretions; the formation of ASA in men and women may be associated with disturbance in immunomodulatory mechanisms that result in functional impairment of sperm and thus its inability to fertilize the oocyte. Immunological infertility caused by ASA is the result of interference of these antibodies in various stages of fertilization process, inhibiting the ability of interaction between sperm and oocyte. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.

  20. Fragmentation of monoclonal antibodies

    Science.gov (United States)

    Vlasak, Josef

    2011-01-01

    Fragmentation is a degradation pathway ubiquitously observed in proteins despite the remarkable stability of peptide bond; proteins differ only by how much and where cleavage occurs. The goal of this review is to summarize reports regarding the non-enzymatic fragmentation of the peptide backbone of monoclonal antibodies (mAbs). The sites in the polypeptide chain susceptible to fragmentation are determined by a multitude of factors. Insights are provided on the intimate chemical mechanisms that can make some bonds prone to cleavage due to the presence of specific side-chains. In addition to primary structure, the secondary, tertiary and quaternary structures have a significant impact in modulating the distribution of cleavage sites by altering local flexibility, accessibility to solvent or bringing in close proximity side chains that are remote in sequence. This review focuses on cleavage sites observed in the constant regions of mAbs, with special emphasis on hinge fragmentation. The mechanisms responsible for backbone cleavage are strongly dependent on pH and can be catalyzed by metals or radicals. The distribution of cleavage sites are different under acidic compared to basic conditions, with fragmentation rates exhibiting a minimum in the pH range 5–6; therefore, the overall fragmentation pattern observed for a mAb is a complex result of structural and solvent conditions. A critical review of the techniques used to monitor fragmentation is also presented; usually a compromise has to be made between a highly sensitive method with good fragment separation and the capability to identify the cleavage site. The effect of fragmentation on the function of a mAb must be evaluated on a case-by-case basis depending on whether cleavage sites are observed in the variable or constant regions, and on the mechanism of action of the molecule. PMID:21487244

  1. Tabhu: tools for antibody humanization.

    KAUST Repository

    Olimpieri, Pier Paolo

    2014-10-09

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

  2. Tabhu: tools for antibody humanization.

    Science.gov (United States)

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

    2015-02-01

    Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can elicit unwanted and dangerous immunogenic responses. Antibody humanization methods are designed to produce molecules with a better safety profile still maintaining their ability to bind the antigen. This can be accomplished by grafting the non-human regions determining the antigen specificity into a suitable human template. Unfortunately, this procedure may results in a partial or complete loss of affinity of the grafted molecule that can be restored by back-mutating some of the residues of human origin to the corresponding murine ones. This trial-and-error procedure is hard and involves expensive and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps of the humanization experiment protocol. http://www.biocomputing.it/tabhu anna.tramontano@uniroma1.it, pierpaolo.olimpieri@uniroma1.it Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press.

  3. Avian Diagnostic and Therapeutic Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, David Sherman [UND SMHS

    2012-12-31

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

  4. Neutralising Antibodies against Ricin Toxin

    Science.gov (United States)

    Prigent, Julie; Panigai, Laetitia; Lamourette, Patricia; Sauvaire, Didier; Devilliers, Karine; Plaisance, Marc; Volland, Hervé; Créminon, Christophe; Simon, Stéphanie

    2011-01-01

    The Centers for Disease Control and Prevention have listed the potential bioweapon ricin as a Category B Agent. Ricin is a so-called A/B toxin produced by plants and is one of the deadliest molecules known. It is easy to prepare and no curative treatment is available. An immunotherapeutic approach could be of interest to attenuate or neutralise the effects of the toxin. We sought to characterise neutralising monoclonal antibodies against ricin and to develop an effective therapy. For this purpose, mouse monoclonal antibodies (mAbs) were produced against the two chains of ricin toxin (RTA and RTB). Seven mAbs were selected for their capacity to neutralise the cytotoxic effects of ricin in vitro. Three of these, two anti-RTB (RB34 and RB37) and one anti-RTA (RA36), when used in combination improved neutralising capacity in vitro with an IC50 of 31 ng/ml. Passive administration of association of these three mixed mAbs (4.7 µg) protected mice from intranasal challenges with ricin (5 LD50). Among those three antibodies, anti-RTB antibodies protected mice more efficiently than the anti-RTA antibody. The combination of the three antibodies protected mice up to 7.5 hours after ricin challenge. The strong in vivo neutralising capacity of this three mAbs combination makes it potentially useful for immunotherapeutic purposes in the case of ricin poisoning or possibly for prevention. PMID:21633505

  5. Neutralising antibodies against ricin toxin.

    Directory of Open Access Journals (Sweden)

    Julie Prigent

    Full Text Available The Centers for Disease Control and Prevention have listed the potential bioweapon ricin as a Category B Agent. Ricin is a so-called A/B toxin produced by plants and is one of the deadliest molecules known. It is easy to prepare and no curative treatment is available. An immunotherapeutic approach could be of interest to attenuate or neutralise the effects of the toxin. We sought to characterise neutralising monoclonal antibodies against ricin and to develop an effective therapy. For this purpose, mouse monoclonal antibodies (mAbs were produced against the two chains of ricin toxin (RTA and RTB. Seven mAbs were selected for their capacity to neutralise the cytotoxic effects of ricin in vitro. Three of these, two anti-RTB (RB34 and RB37 and one anti-RTA (RA36, when used in combination improved neutralising capacity in vitro with an IC(50 of 31 ng/ml. Passive administration of association of these three mixed mAbs (4.7 µg protected mice from intranasal challenges with ricin (5 LD(50. Among those three antibodies, anti-RTB antibodies protected mice more efficiently than the anti-RTA antibody. The combination of the three antibodies protected mice up to 7.5 hours after ricin challenge. The strong in vivo neutralising capacity of this three mAbs combination makes it potentially useful for immunotherapeutic purposes in the case of ricin poisoning or possibly for prevention.

  6. Detection of serum anti-B/B’ UsnRNP antibodies in patients with connective tissue diseases by immunoblotting

    Directory of Open Access Journals (Sweden)

    L. Iaccarino

    2011-09-01

    Full Text Available Objective: To investigate the reliability of the immunoblot method in the detection of serum immunoreactivity towards the B/B’ polypeptides of U small nuclear ribonucleoproteins (UsnRNP and to assess the significance of these antibodies in connective tissue disease (CTD patients. Methods: We tested the sera of 348 patients with CTD (101 SLE, 51 systemic sclerosis, 53 primary Sjogren’s syndrome, 27 poly/dermatomyositis, 15 rheumatoid arthritis and 101 overlap CTD, of 31 matched healthy subjects and 13 patients with primary Epstein-Barr virus (EBV infection with high titre IgG anti-EBV antibodies. IgG anti-UsnRNP antibodies were determined by immunoblotting on nuclear extract from Raji cells (an EBV-immortalised human B lymphoid cell line and Jurkat cells (a human T lymphoid cell line. Anti-dsDNA antibodies were detected by indirect immunofluorescence on Crithidia luciliae and anti-ENA by counterimmunoelectrophoresis. Anti-dsDNA activity and avidity were measured in SLE sera by ELISA with Scatchard analysis. Results were statistically analysed by chi-square and Mann-Whitney tests. Results: A high frequency of anti-B/B’ antibodies was found in the sera of CTD patients, confined to SLE (54.4% and overlap CTD with SLE features (55,2%. Anti-B/B’ immune reactivity was closely associated with other anti-UsnRNP specificities, gel precipitating anti-nRNP and anti-P antibodies. Nine out of 15 (60% anti-B/B’ positive/anti-ENA negative lupus sera on Raji blots were confirmed to be positive also on Jurkat blots. The sera from patients with EBV infection provided, on Raji blots, completely different band patterns from those obtained with auto-immune sera. Conclusions. The Sm B/B’ proteins are the predominant or, at least, the most frequently targeted antigens of the UsnRNP auto-immune response in SLE and “lupus-like” overlap CTD. Moreover, anti-B/B’ is diagnostically specific for CTD with SLE features. Immunoblotting on human B lymphoid cells

  7. Replacing reprogramming factors with antibodies selected from combinatorial antibody libraries.

    Science.gov (United States)

    Blanchard, Joel W; Xie, Jia; El-Mecharrafie, Nadja; Gross, Simon; Lee, Sohyon; Lerner, Richard A; Baldwin, Kristin K

    2017-10-01

    The reprogramming of differentiated cells into induced pluripotent stem cells (iPSCs) is usually achieved by exogenous induction of transcription by factors acting in the nucleus. In contrast, during development, signaling pathways initiated at the membrane induce differentiation. The central idea of this study is to identify antibodies that can catalyze cellular de-differentiation and nuclear reprogramming by acting at the cell surface. We screen a lentiviral library encoding ∼100 million secreted and membrane-bound single-chain antibodies and identify antibodies that can replace either Sox2 and Myc (c-Myc) or Oct4 during reprogramming of mouse embryonic fibroblasts into iPSCs. We show that one Sox2-replacing antibody antagonizes the membrane-associated protein Basp1, thereby de-repressing nuclear factors WT1, Esrrb and Lin28a (Lin28) independent of Sox2. By manipulating this pathway, we identify three methods to generate iPSCs. Our results establish unbiased selection from autocrine combinatorial antibody libraries as a robust method to discover new biologics and uncover membrane-to-nucleus signaling pathways that regulate pluripotency and cell fate.

  8. Antibody-Directed Phototherapy (ADP

    Directory of Open Access Journals (Sweden)

    M. Adil Butt

    2013-04-01

    Full Text Available Photodynamic therapy (PDT is a clinically-approved but rather under-exploited treatment modality for cancer and pre-cancerous superficial lesions. It utilises a cold laser or LED to activate a photochemical reaction between a light activated drug (photosensitiser-drug and oxygen to generate cytotoxic oxygen species. These free radical species damage cellular components leading to cell death. Despite its benefits, the complexity, limited potency and side effects of PDT have led to poor general usage. However, the research area is very active with an increasing understanding of PDT-related cell biology, photophysics and significant progress in molecular targeting of disease. Monoclonal antibody therapy is maturing and the next wave of antibody therapies includes antibody-drug conjugates (ADCs, which promise to be more potent and curable. These developments could lift antibody-directed phototherapy (ADP to success. ADP promises to increase specificity and potency and improve drug pharmacokinetics, thus delivering better PDT drugs whilst retaining its other benefits. Whole antibody conjugates with first generation ADP-drugs displayed problems with aggregation, poor pharmacokinetics and loss of immuno-reactivity. However, these early ADP-drugs still showed improved selectivity and potency. Improved PS-drug chemistry and a variety of conjugation strategies have led to improved ADP-drugs with retained antibody and PS-drug function. More recently, recombinant antibody fragments have been used to deliver ADP-drugs with superior drug loading, more favourable pharmacokinetics, enhanced potency and target cell selectivity. These improvements offer a promise of better quality PDT drugs.

  9. Antibodies from plants for bionanomaterials.

    Science.gov (United States)

    Edgue, Gueven; Twyman, Richard M; Beiss, Veronique; Fischer, Rainer; Sack, Markus

    2017-11-01

    Antibodies are produced as part of the vertebrate adaptive immune response and are not naturally made by plants. However, antibody DNA sequences can be introduced into plants, and together with laboratory technologies that allow the design of antibodies recognizing any conceivable molecular structure, plants can be used as 'green factories' to produce any antibody at all. The advent of plant-based transient expression systems in particular allows the rapid, convenient, and safe production of antibodies, ranging from laboratory-scale expression to industrial-scale manufacturing. The key features of plant-based production include safety, speed, low cost, and convenience, allowing newcomers to rapidly master the technology and use it to its full advantage. Manufacturing in plants has recently achieved significant milestones and offers more than just an alternative to established microbial and mammalian cell platforms. The use of plants for product development in particular offers the power and flexibility to easily coexpress many different genes, allowing the plug-and-play construction of novel bionanomaterials, perfectly complementing existing approaches based on plant virus-like particles. As well as producing single antibodies for applications in medicine, agriculture, and industry, plants can be used to produce antibody-based supramolecular structures and scaffolds as a new generation of green bionanomaterials that promise a bright future based on clean and renewable nanotechnology applications. WIREs Nanomed Nanobiotechnol 2017, 9:e1462. doi: 10.1002/wnan.1462 For further resources related to this article, please visit the WIREs website. © 2017 The Authors. WIREs Nanomedicine and Nanobiotechnology published by Wiley Periodicals, Inc.

  10. Influence of Acyclovir on Antibody Production of Antibody to Chickenpox

    OpenAIRE

    Atsutoshi, Tsuji; Takayoshi, Tsuchiya; Yuuko, Nagaoka; Toshiro, Nagai; Department of Pediatrics, Saitama Municipal Hospital; College of Health Professions, Toho University; Department of Pediatrics, Dokkyo University, Koshigaya Hospital

    2003-01-01

    Titers of immunoglobulin (Ig) G and 1gM antibody to varicella zoster virus (VZV) were measured in 20 pediatric patients with chickenpox during treatment with acyclovir, an antiviral agent. Acyclovir doses, each 80 mg/kg/day, were administered for 5 days, beginning within 4 days after the onset of the rash. All patients displayed positive IgG and/or 1gM anti-VZV antibodies. No significant difference was noted in the IgG (p = 0.417) or IgM titer (p = 0.846) between patients treated within 24 ho...

  11. Programmatic evaluation of a combined antigen and antibody test for rapid HIV diagnosis in a community and sexual health clinic screening programme.

    Science.gov (United States)

    Taegtmeyer, Miriam; MacPherson, Peter; Jones, Kathy; Hopkins, Mark; Moorcroft, Jay; Lalloo, David G; Chawla, Anu

    2011-01-01

    A substantial proportion of HIV-infected individuals in the UK are unaware of their status and late presentations continue, especially in low prevalence areas. Fourth generation antigen/antibody rapid test kits could facilitate earlier diagnosis of HIV in non-clinical settings but lack data on performance under programmatic conditions. We evaluated the performance of Determine HIV-1/2 Ag/Ab Combo Test (Determine Combo), a rapid test with indicators for both HIV antibodies and p24 antigen, in participants recruited from community outreach and hospital-based sexual health clinics. HIV infection was confirmed using laboratory enzyme-linked immunosorbent assay (EIA), Line Immuno Assay (LIA) and quantitative polymerase chain reaction (PCR). In total, 953 people underwent HIV testing. HIV antibody (Ab) prevalence was 1.8% (17/953). Four false positive rapid tests were identified: two antibody and two p24 antigen (Ag) reactions. Of participants diagnosed as HIV Ab positive, 2/17 (12%) were recent seroconverters based on clinical history and HIV antibody avidity test results. However, none of these were detected by the p24 antigen component of the rapid test kit. There were no other true positive p24 Ag tests. These data lend support to an increasing body of evidence suggesting that 4th generation rapid HIV tests have little additional benefit over 3rd generation HIV kits for routine screening in low prevalence settings and have high rates of false positives. In order to optimally combine community-based case-finding among hard-to-reach groups with reliable and early diagnosis 3rd generation kits should be primarily used with laboratory testing of individuals thought to be at risk of acute HIV infection. A more reliable point of care diagnostic is required for the accurate detection of acute HIV infection under programmatic conditions.

  12. Programmatic evaluation of a combined antigen and antibody test for rapid HIV diagnosis in a community and sexual health clinic screening programme.

    Directory of Open Access Journals (Sweden)

    Miriam Taegtmeyer

    Full Text Available BACKGROUND: A substantial proportion of HIV-infected individuals in the UK are unaware of their status and late presentations continue, especially in low prevalence areas. Fourth generation antigen/antibody rapid test kits could facilitate earlier diagnosis of HIV in non-clinical settings but lack data on performance under programmatic conditions. METHODS AND FINDINGS: We evaluated the performance of Determine HIV-1/2 Ag/Ab Combo Test (Determine Combo, a rapid test with indicators for both HIV antibodies and p24 antigen, in participants recruited from community outreach and hospital-based sexual health clinics. HIV infection was confirmed using laboratory enzyme-linked immunosorbent assay (EIA, Line Immuno Assay (LIA and quantitative polymerase chain reaction (PCR. In total, 953 people underwent HIV testing. HIV antibody (Ab prevalence was 1.8% (17/953. Four false positive rapid tests were identified: two antibody and two p24 antigen (Ag reactions. Of participants diagnosed as HIV Ab positive, 2/17 (12% were recent seroconverters based on clinical history and HIV antibody avidity test results. However, none of these were detected by the p24 antigen component of the rapid test kit. There were no other true positive p24 Ag tests. CONCLUSION: These data lend support to an increasing body of evidence suggesting that 4th generation rapid HIV tests have little additional benefit over 3rd generation HIV kits for routine screening in low prevalence settings and have high rates of false positives. In order to optimally combine community-based case-finding among hard-to-reach groups with reliable and early diagnosis 3rd generation kits should be primarily used with laboratory testing of individuals thought to be at risk of acute HIV infection. A more reliable point of care diagnostic is required for the accurate detection of acute HIV infection under programmatic conditions.

  13. Tabhu: tools for antibody humanization

    DEFF Research Database (Denmark)

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

    2015-01-01

    Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can...... elicit unwanted and dangerous immunogenic responses. Antibody humanization methods are designed to produce molecules with a better safety profile still maintaining their ability to bind the antigen. This can be accomplished by grafting the non-human regions determining the antigen specificity...... into a suitable human template. Unfortunately, this procedure may results in a partial or complete loss of affinity of the grafted molecule that can be restored by back-mutating some of the residues of human origin to the corresponding murine ones. This trial-and-error procedure is hard and involves expensive...

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

    DEFF Research Database (Denmark)

    Owens, T; Fazekas de St Groth, B

    1987-01-01

    The recognition of many class II major histocompatibility complex (MHC)-associated antigens by T cells requires the participation of the L3T4 molecule. It has been proposed that this molecule acts to stabilize low affinity binding to antigen in association with MHC and thereby increases the avidity...... of T cell/antigen interactions. By using antibodies against the T cell antigen receptor (TCR) to activate T cells, thereby circumventing the requirement for antigen presenting cells and MHC-associated antigen, we have been able to study the function of L3T4 in the absence of class II MHC. We have used...... two monoclonal antibodies, KJ16-133.18 and F23.1, that recognize a determinant encoded by the T cell receptor V beta 8 gene family. These antibodies were used to select two clones of T cells with surface phenotype Thy-1.2+, L3T4+, Lyt-2-, KJ16-133.18+, F23.1+, IA-, IE-. One of these clones (E9.D4...

  15. Antiphospholipid antibody in localised scleroderma.

    Science.gov (United States)

    Sato, S; Fujimoto, M; Hasegawa, M; Takehara, K

    2003-08-01

    To investigate the prevalence and clinical correlation of antiphospholipid antibodies in localised scleroderma. Antibodies against cardiolipin (aCL) or beta(2)-glycoprotein I were examined by enzyme linked immunosorbent assay (ELISA) in 48 patients with localised scleroderma (18 patients with generalised morphoea, 20 with linear scleroderma, and 10 with morphoea). Twenty one of these patients were investigated for lupus anticoagulant (LAC) by screening and confirmatory coagulation tests. Patients with generalised morphoea, the severest form of localised scleroderma, had significantly raised levels of IgM or IgG aCL relative to normal controls (n=21) and patients with systemic sclerosis (n=20). The IgM isotype was predominant, with the frequency of IgM aCL (61%) higher than that of IgG aCL (28%). Levels of aCL were similar for patients with linear scleroderma or morphoea and normal controls. IgM aCL were associated with a greater number of lesions, especially plaque lesions, wider distribution of lesions, and the presence of immunological abnormalities including antinuclear antibodies, rheumatoid factor, IgM antihistone antibodies, IgG anti-single stranded DNA antibodies, and raised serum interleukin 6 levels in patients with localised scleroderma. LAC was detected in 5/7 (71%) patients with generalised morphoea. However, pulmonary embolism was seen in only one patient with generalised morphoea. None of patients with localised scleroderma exhibited anti-beta(2)-glycoprotein I antibodies. These results suggest that aCL and LAC are the major autoantibodies in patients with generalised morphoea.

  16. Uses of monoclonal antibody 8H9

    Science.gov (United States)

    Cheung, Nai-Kong V.

    2013-04-09

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

  17. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S

    2010-04-13

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  18. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S.

    2017-03-28

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  19. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A; Thompson, Vicki S

    2013-02-26

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  20. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S.

    2013-02-26

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  1. Generation of recombinant single-chain antibodies neutralizing the cytolytic activity of vaginolysin, the main virulence factor of Gardnerella vaginalis.

    Science.gov (United States)

    Pleckaityte, Milda; Mistiniene, Edita; Lasickiene, Rita; Zvirblis, Gintautas; Zvirbliene, Aurelija

    2011-11-03

    Gardnerella vaginalis is identified as the predominant colonist of the vaginal tract in women with bacterial vaginosis. Vaginolysin (VLY) is a protein toxin released by G. vaginalis. VLY possesses cytolytic activity and is considered as a main virulence factor of G. vaginalis. Inhibition of VLY-mediated cell lysis by antibodies may have important physiological relevance. Single-chain variable fragments of immunoglobulins (scFvs) were cloned from two hybridoma cell lines producing neutralizing antibodies against VLY and expressed as active proteins in E. coli. For each hybridoma, two variants of anti-VLY scFv consisting of either VL-VH or VH-VL linked with a 20 aa-long linker sequence (G₄S)₄ were constructed. Recovery of scFvs from inclusion bodies with subsequent purification by metal-chelate chromatography resulted in VLY-binding proteins that were predominantly monomeric. The antigen-binding activity of purified scFvs was verified by an indirect ELISA. The neutralizing activity was investigated by in vitro hemolytic assay and cytolytic assay using HeLa cell line. Calculated apparent Kd values and neutralizing potency of scFvs were in agreement with those of parental full-length antibodies. VH-VL and VL-VH variants of scFvs showed similar affinity and neutralizing potency. The anti-VLY scFvs derived from hybridoma clone 9B4 exhibited high VLY-neutralizing activity both on human erythrocytes and cervical epithelial HeLa cells. Hybridoma-derived scFvs with VLY-binding activity were expressed in E. coli. Recombinant anti-VLY scFvs inhibited VLY-mediated cell lysis. The monovalent scFvs showed reduced affinity and neutralizing potency as compared to the respective full-length antibodies. The loss of avidity could be restored by generating scFv constructs with multivalent binding properties. Generated scFvs is the first example of recombinant single-chain antibodies with VLY-neutralizing activity produced in prokaryote expression system. G. vaginalis caused

  2. Generation of recombinant single-chain antibodies neutralizing the cytolytic activity of vaginolysin, the main virulence factor of Gardnerella vaginalis

    Directory of Open Access Journals (Sweden)

    Pleckaityte Milda

    2011-11-01

    Full Text Available Abstract Background Gardnerella vaginalis is identified as the predominant colonist of the vaginal tract in women with bacterial vaginosis. Vaginolysin (VLY is a protein toxin released by G. vaginalis. VLY possesses cytolytic activity and is considered as a main virulence factor of G. vaginalis. Inhibition of VLY-mediated cell lysis by antibodies may have important physiological relevance. Results Single-chain variable fragments of immunoglobulins (scFvs were cloned from two hybridoma cell lines producing neutralizing antibodies against VLY and expressed as active proteins in E. coli. For each hybridoma, two variants of anti-VLY scFv consisting of either VL-VH or VH-VL linked with a 20 aa-long linker sequence (G4S4 were constructed. Recovery of scFvs from inclusion bodies with subsequent purification by metal-chelate chromatography resulted in VLY-binding proteins that were predominantly monomeric. The antigen-binding activity of purified scFvs was verified by an indirect ELISA. The neutralizing activity was investigated by in vitro hemolytic assay and cytolytic assay using HeLa cell line. Calculated apparent Kd values and neutralizing potency of scFvs were in agreement with those of parental full-length antibodies. VH-VL and VL-VH variants of scFvs showed similar affinity and neutralizing potency. The anti-VLY scFvs derived from hybridoma clone 9B4 exhibited high VLY-neutralizing activity both on human erythrocytes and cervical epithelial HeLa cells. Conclusions Hybridoma-derived scFvs with VLY-binding activity were expressed in E. coli. Recombinant anti-VLY scFvs inhibited VLY-mediated cell lysis. The monovalent scFvs showed reduced affinity and neutralizing potency as compared to the respective full-length antibodies. The loss of avidity could be restored by generating scFv constructs with multivalent binding properties. Generated scFvs is the first example of recombinant single-chain antibodies with VLY-neutralizing activity produced in

  3. Relevance of the Diversity among Members of the Trypanosoma Cruzi Trans-Sialidase Family Analyzed with Camelids Single-Domain Antibodies

    Science.gov (United States)

    Paris, Gastón; Zarebski, Laura; Frasch, Alberto C.; Goldbaum, Fernando A.

    2008-01-01

    The sialic acid present in the protective surface mucin coat of Trypanosoma cruzi is added by a membrane anchored trans-sialidase (TcTS), a modified sialidase that is expressed from a large gene family. In this work, we analyzed single domain camelid antibodies produced against trans-sialidase. Llamas were immunized with a recombinant trans-sialidase and inhibitory single-domain antibody fragments were obtained by phage display selection, taking advantage of a screening strategy using an inhibition test instead of the classic binding assay. Four single domain antibodies displaying strong trans-sialidase inhibition activity against the recombinant enzyme were identified. They share the same complementarity-determining region 3 length (17 residues) and have very similar sequences. This result indicates that they likely derived from a unique clone. Probably there is only one structural solution for tight binding inhibitory antibodies against the TcTS used for immunization. To our surprise, this single domain antibody that inhibits the recombinant TcTS, failed to inhibit the enzymatic activity present in parasite extracts. Analysis of individual recombinant trans-sialidases showed that enzymes expressed from different genes were inhibited to different extents (from 8 to 98%) by the llama antibodies. Amino acid changes at key positions are likely to be responsible for the differences in inhibition found among the recombinant enzymes. These results suggest that the presence of a large and diverse trans-sialidase family might be required to prevent the inhibitory response against this essential enzyme and might thus constitute a novel strategy of T. cruzi to evade the host immune system. PMID:18949046

  4. Relevance of the diversity among members of the Trypanosoma cruzi trans-sialidase family analyzed with camelids single-domain antibodies.

    Directory of Open Access Journals (Sweden)

    Laura Ratier

    Full Text Available The sialic acid present in the protective surface mucin coat of Trypanosoma cruzi is added by a membrane anchored trans-sialidase (TcTS, a modified sialidase that is expressed from a large gene family. In this work, we analyzed single domain camelid antibodies produced against trans-sialidase. Llamas were immunized with a recombinant trans-sialidase and inhibitory single-domain antibody fragments were obtained by phage display selection, taking advantage of a screening strategy using an inhibition test instead of the classic binding assay. Four single domain antibodies displaying strong trans-sialidase inhibition activity against the recombinant enzyme were identified. They share the same complementarity-determining region 3 length (17 residues and have very similar sequences. This result indicates that they likely derived from a unique clone. Probably there is only one structural solution for tight binding inhibitory antibodies against the TcTS used for immunization. To our surprise, this single domain antibody that inhibits the recombinant TcTS, failed to inhibit the enzymatic activity present in parasite extracts. Analysis of individual recombinant trans-sialidases showed that enzymes expressed from different genes were inhibited to different extents (from 8 to 98% by the llama antibodies. Amino acid changes at key positions are likely to be responsible for the differences in inhibition found among the recombinant enzymes. These results suggest that the presence of a large and diverse trans-sialidase family might be required to prevent the inhibitory response against this essential enzyme and might thus constitute a novel strategy of T. cruzi to evade the host immune system.

  5. Nivolumab and pembrolizumab: Monoclonal antibodies against programmed cell death-1 (PD-1) that are interchangeable.

    Science.gov (United States)

    Prasad, Vinay; Kaestner, Victoria

    2017-04-01

    Nivolumab (Opdivo, Bristol Meyer Squibb, New York, NY) and pembrolizumab (Keytruda, Merck, Kenilworth, NJ) are the first two US Food and Drug Administration (FDA)-approved monoclonal antibodies targeting programmed death-1 (PD-1). Nivolumab and pembrolizumab work by interfering with the interaction between PD-1 and programmed death ligand-1 (PD-L1), whose unimpeded interaction downregulates T cells allowing cancer cells to evade immune surveillance. These drugs have earned a series of FDA approvals for melanoma, non-small cell lung cancer (NSCLC), head and neck squamous cell cancer (HNSCC), urothelial cancer, classical Hodgkin lymphoma, and renal cell cancer. In this review we will summarize the data for efficacy and toxicity for these two agents. We conclude that they represent two valuable but interchangeable alternatives to target their approved indications. We will discuss how this can help global payers seeking to contain the cost of cancer therapeutics that continues to spiral out of control. Copyright © 2017. Published by Elsevier Inc.

  6. General solutions to decompose heterogeneous compositions using antibody afucosylation as a model system.

    Science.gov (United States)

    Chung, John D; Zhan, Peter L

    2017-03-01

    Methods involving the use of mathematical models of competitive ligand-receptor binding to characterize mixtures of ligands in terms of compositions and properties of the component ligands have been developed. The associated mathematical equations explicitly relate component ligand physical-chemical properties and mole fractions to measurable properties of the mixture including steady state binding activity, 1/Kd,apparent or equivalently 1/EC50, and kinetic rate constants kon,apparent and koff,apparent allowing: (1) component ligand physical property determination and (2) mixture property predictions. Additionally, mathematical equations accounting for combinatorial considerations associated with ligand assembly are used to compute ligand mole fractions. The utility of the methods developed is demonstrated using published experimental ligand-receptor binding data obtained from mixtures of afucosylated antibodies that bind FcγRIIIa (CD16a) to: (1) extract component ligand physical property information that has hitherto evaded researchers, (2) predict experimental observations, and (3) provide explanations for unresolved experimental observations. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:500-510, 2017. © 2017 American Institute of Chemical Engineers.

  7. Development of Patient-specific AAV Vectors After Neutralizing Antibody Selection for Enhanced Muscle Gene Transfer.

    Science.gov (United States)

    Li, Chengwen; Wu, Shuqing; Albright, Blake; Hirsch, Matthew; Li, Wuping; Tseng, Yu-Shan; Agbandje-McKenna, Mavis; McPhee, Scott; Asokan, Aravind; Samulski, R Jude

    2016-02-01

    A major hindrance in gene therapy trials with adeno-associated virus (AAV) vectors is the presence of neutralizing antibodies (NAbs) that inhibit AAV transduction. In this study, we used directed evolution techniques in vitro and in mouse muscle to select novel NAb escape AAV chimeric capsid mutants in the presence of individual patient serum. AAV mutants isolated in vitro escaped broad patient-specific NAb activity but had poor transduction ability in vivo. AAV mutants isolated in vivo had enhanced NAb evasion from cognate serum and had high muscle transduction ability. More importantly, structural modeling identified a 100 amino acid motif from AAV6 in variable region (VR) III that confers this enhanced muscle tropism. In addition, a predominantly AAV8 capsid beta barrel template with a specific preference for AAV1/AAV9 in VR VII located at threefold symmetry axis facilitates NAb escape. Our data strongly support that chimeric AAV capsids composed of modular and nonoverlapping domains from various serotypes are capable of evading patient-specific NAbs and have enhanced muscle transduction.

  8. Antiphospholipid antibody in localised scleroderma

    OpenAIRE

    Sato, S.; Fujimoto, M; Hasegawa, M.; Takehara, K.

    2003-01-01

    Methods: Antibodies against cardiolipin (aCL) or ß2-glycoprotein I were examined by enzyme linked immunosorbent assay (ELISA) in 48 patients with localised scleroderma (18 patients with generalised morphoea, 20 with linear scleroderma, and 10 with morphoea). Twenty one of these patients were investigated for lupus anticoagulant (LAC) by screening and confirmatory coagulation tests.

  9. Monoclonal antibodies to Treponema Pallidum.

    NARCIS (Netherlands)

    H.J.M. van de Donk; J.D.A. van Embden; M.F. van Olderen; A.D.M.E. Osterhaus (Albert); J.C. de Jong (Jan)

    1984-01-01

    textabstractThree successive fusions of mouse myeloma cells and spleen lymphocytes of a mouse immunized with Treponema Pallidum resulted in one hybridoma producing anti T. pallidum antibodies for each fusion. The mice were immunized with live pallidum cells respectively 1, 3 and 5 months before

  10. antibodies against Herpes simplex virus

    African Journals Online (AJOL)

    Herpes simplex virus (HSV) types -1 and -2 in pregnant women in. Port Harcourt, Nigeria. ... Cite as: Okonko IO, Cookey TI. Seropositivity and determinants of immunoglobulin-G (IgG) antibodies against Herpes simplex virus (HSV) ..... zadeh, Z. and Akbari, S. Seroepidemiology of Herpes. Simplex Virus Type 1 and 2 in ...

  11. Polymyalgia rheumatica and antimitochondrial antibodies.

    Science.gov (United States)

    Sattar, M A; Cawley, M I; Hamblin, T J; Robertson, J C

    1984-01-01

    Antimitochondrial antibodies (AMA) were detected in the sera of 11 of 36 patients with a clinical diagnosis of polymyalgia rheumatica (PMR) in whom comprehensive autoantibody screening had been performed. AMA did not correlate with biochemical changes of hepatic dysfunction, which are common in PMR, nor with parameters of musculoskeletal inflammation. Possible explanations are discussed. PMID:6712299

  12. Polymyalgia rheumatica and antimitochondrial antibodies.

    OpenAIRE

    Sattar, M A; Cawley, M I; Hamblin, T J; Robertson, J C

    1984-01-01

    Antimitochondrial antibodies (AMA) were detected in the sera of 11 of 36 patients with a clinical diagnosis of polymyalgia rheumatica (PMR) in whom comprehensive autoantibody screening had been performed. AMA did not correlate with biochemical changes of hepatic dysfunction, which are common in PMR, nor with parameters of musculoskeletal inflammation. Possible explanations are discussed.

  13. Monoclonal antibodies: application in radiopharmacy.

    Science.gov (United States)

    Ligiero, Thais Braga; de Souza Albernaz, Marta; de Carvalho, Samira Marques; de Oliveira, Silvia Maria Velasques; Santos-Oliveira, Ralph

    2013-12-01

    In this study was carried on a systematic review of the data was carried out in the topic of monoclonal antibodies in the last 40 years. All the data collected and summarized revealed that this new class of medicine may bring great advance in the field of radiopharmacy, oncology and imaging.

  14. Bispecific antibodies: design, therapy, perspectives

    Directory of Open Access Journals (Sweden)

    Sedykh SE

    2018-01-01

    Full Text Available Sergey E Sedykh, Victor V Prinz, Valentina N Buneva, Georgy A Nevinsky Laboratory of Repair Enzymes, Siberian Branch of Russian Academy of Sciences Institute of Chemical Biology and Fundamental Medicine, Novosibirsk State University, Novosibirsk, Russia Abstract: Antibodies (Abs containing two different antigen-binding sites in one molecule are called bispecific. Bispecific Abs (BsAbs were first described in the 1960s, the first monoclonal BsAbs were generated in the 1980s by hybridoma technology, and the first article describing the therapeutic use of BsAbs was published in 1992, but the number of papers devoted to BsAbs has increased significantly in the last 10 years. Particular interest in BsAbs is due to their therapeutic use. In the last decade, two BsAbs – catumaxomab in 2009 and blinatumomab in 2014, were approved for therapeutic use. Papers published in recent years have been devoted to various methods of BsAb generation by genetic engineering and chemical conjugation, and describe preclinical and clinical trials of these drugs in a variety of diseases. This review considers diverse BsAb-production methods, describes features of therapeutic BsAbs approved for medical use, and summarizes the prospects of practical application of promising new BsAbs. Keywords: bispecific antibodies, therapeutic antibodies, monoclonal antibodies

  15. Antibody Repertoire Development in Swine

    Czech Academy of Sciences Publication Activity Database

    Butler, J. E.; Wertz, N.; Šinkora, Marek

    2017-01-01

    Roč. 5, FEB 17 (2017), s. 255-279 ISSN 2165-8102 R&D Projects: GA ČR GA15-02274S; GA ČR(CZ) GA16-09296S Institutional support: RVO:61388971 Keywords : swine * pre-immune antibody repertoire * ileal Peyer's patches Subject RIV: EE - Microbiology, Virology Impact factor: 4.708, year: 2016

  16. Polyclonal and monoclonal antibodies in clinic.

    Science.gov (United States)

    Wootla, Bharath; Denic, Aleksandar; Rodriguez, Moses

    2014-01-01

    Immunoglobulins (Ig) or antibodies are heavy plasma proteins, with sugar chains added to amino-acid residues by N-linked glycosylation and occasionally by O-linked glycosylation. The versatility of antibodies is demonstrated by the various functions that they mediate such as neutralization, agglutination, fixation with activation of complement and activation of effector cells. Naturally occurring antibodies protect the organism against harmful pathogens, viruses and infections. In addition, almost any organic chemical induces antibody production of antibodies that would bind specifically to the chemical. These antibodies are often produced from multiple B cell clones and referred to as polyclonal antibodies. In recent years, scientists have exploited the highly evolved machinery of the immune system to produce structurally and functionally complex molecules such as antibodies from a single B clone, heralding the era of monoclonal antibodies. Most of the antibodies currently in the clinic, target components of the immune system, are not curative and seek to alleviate symptoms rather than cure disease. Our group used a novel strategy to identify reparative human monoclonal antibodies distinct from conventional antibodies. In this chapter, we discuss the therapeutic relevance of both polyclonal and monoclonal antibodies in clinic.

  17. Therapeutic Antibodies to Ganglioside GD2 Evolved from Highly Selective Germline Antibodies

    Directory of Open Access Journals (Sweden)

    Eric Sterner

    2017-08-01

    Full Text Available Antibodies play a crucial role in host defense and are indispensable research tools, diagnostics, and therapeutics. Antibody generation involves binding of genomically encoded germline antibodies followed by somatic hypermutation and in vivo selection to obtain antibodies with high affinity and selectivity. Understanding this process is critical for developing monoclonal antibodies, designing effective vaccines, and understanding autoantibody formation. Prior studies have found that antibodies to haptens, peptides, and proteins evolve from polyspecific germline antibodies. The immunological evolution of antibodies to mammalian glycans has not been studied. Using glycan microarrays, protein microarrays, cell binding studies, and molecular modeling, we demonstrate that therapeutic antibodies to the tumor-associated ganglioside GD2 evolved from highly specific germline precursors. The results have important implications for developing vaccines and monoclonal antibodies that target carbohydrate antigens. In addition, they demonstrate an alternative pathway for antibody evolution within the immune system that is distinct from the polyspecific germline pathway.

  18. Detection of Campylobacter species using monoclonal antibodies

    Science.gov (United States)

    Young, Colin R.; Lee, Alice; Stanker, Larry H.

    1999-01-01

    A panel of species specific monoclonal antibodies were raised to Campylobacter coli, Campylobacter jejuni and Campylobacter lari. The isotypes, and cross-reactivity profiles of each monoclonal antibody against an extensive panel of micro- organisms, were determined.

  19. Humanization and simultaneous optimization of monoclonal antibody.

    Science.gov (United States)

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

    2014-01-01

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

  20. Antibody therapeutics - the evolving patent landscape.

    Science.gov (United States)

    Petering, Jenny; McManamny, Patrick; Honeyman, Jane

    2011-09-01

    The antibody patent landscape has evolved dramatically over the past 30 years, particularly in areas of technology relating to antibody modification to reduce immunogenicity in humans or improve antibody function. In some cases antibody techniques that were developed in the 1980s are still the subject of patent protection in the United States or Canada. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Isolation of a high affinity neutralizing monoclonal antibody against 2009 pandemic H1N1 virus that binds at the 'Sa' antigenic site.

    Directory of Open Access Journals (Sweden)

    Nachiket Shembekar

    Full Text Available Influenza virus evades host immunity through antigenic drift and shift, and continues to circulate in the human population causing periodic outbreaks including the recent 2009 pandemic. A large segment of the population was potentially susceptible to this novel strain of virus. Historically, monoclonal antibodies (MAbs have been fundamental tools for diagnosis and epitope mapping of influenza viruses and their importance as an alternate treatment option is also being realized. The current study describes isolation of a high affinity (K(D = 2.1±0.4 pM murine MAb, MA2077 that binds specifically to the hemagglutinin (HA surface glycoprotein of the pandemic virus. The antibody neutralized the 2009 pandemic H1N1 virus in an in vitro microneutralization assay (IC(50 = 0.08 µg/ml. MA2077 also showed hemagglutination inhibition activity (HI titre of 0.50 µg/ml against the pandemic virus. In a competition ELISA, MA2077 competed with the binding site of the human MAb, 2D1 (isolated from a survivor of the 1918 Spanish flu pandemic on pandemic H1N1 HA. Epitope mapping studies using yeast cell-surface display of a stable HA1 fragment, wherein 'Sa' and 'Sb' sites were independently mutated, localized the binding site of MA2077 within the 'Sa' antigenic site. These studies will facilitate our understanding of antigen antibody interaction in the context of neutralization of the pandemic influenza virus.

  2. ANCA / MPO / PR3 Antibodies Test

    Science.gov (United States)

    ... High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV ... palpath.com . Accessed June 2010. (© 1995–2010) Unit Code 83012: Antineutrophil Cytoplasmic Antibodies Vasculitis Panel, Serum. Mayo ...

  3. Heparin-Induced Thrombocytopenia Antibody Test

    Science.gov (United States)

    ... High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV ... Sources Used in Previous Reviews (© 1995-2011). Unit Code 81904: Heparin-PF4 Antibody (HIT), Serum. Mayo Clinic ...

  4. Antibodies Against Melanin | Wassermann | South African Medical ...

    African Journals Online (AJOL)

    This study reports on unsuccessful attempts to produce antibodies against melanoprotein in rabbits. Available evidence suggests antibodies against melanocytes in the aetiology of vitiligo, but there is no convincing evidence for antibodies against melanin per se. It is suggested that the demonstration of antibodif's against ...

  5. Use of a polyanionic carbomer, Carbopol971P, in combination with MF59, improves antibody responses to HIV-1 envelope glycoprotein

    Science.gov (United States)

    Dey, Antu K.; Burke, Brian; Sun, Yide; Hartog, Karin; Heeney, Jonathan L.; Montefiori, David; Srivastava, Indresh K.; Barnett, Susan W.

    2012-01-01

    Identification of optimal antigen(s) and adjuvant combination(s) to elicit potent, protective, and long-lasting immunity has been a major challenge for the development of effective vaccines against chronic viral pathogens, such as HIV-1, for which there are not yet any licensed vaccines. Here we describe the use of a novel adjuvant approach employing Carbopol 971P® NF (hereafter referred to as Carbopol971P), a cross-linked polyanionic carbomer, in combination with the Novartis proprietary oil-in-water adjuvant, MF59, as a potentially safe and effective adjuvant to augment humoral immune responses to the HIV-1 envelope glycoprotein (Env). Intramuscular immunization of small animals with recombinant Env glycoprotein (gp140) formulated in Carbopol971P plus MF59 gave significantly higher titers of binding and virus neutralizing antibodies as compared to immunization using gp140 with either MF59 or Carbopol971P alone. In addition, the antibodies generated were of higher avidity. Importantly, the use of Carbopol971P plus MF59 did not cause any serious adverse reactions or any obvious health problems in animals upon intramuscular administration. Hence, the Carbopol971P plus MF59 adjuvant formulation may provide a benefit for future vaccine applications. PMID:22366638

  6. A Novel Single-Domain Antibody Against von Willebrand Factor A1 Domain Resolves Leukocyte Recruitment and Vascular Leakage During Inflammation-Brief Report.

    Science.gov (United States)

    Aymé, Gabriel; Adam, Frédéric; Legendre, Paulette; Bazaa, Amine; Proulle, Valérie; Denis, Cécile V; Christophe, Olivier D; Lenting, Peter J

    2017-09-01

    von Willebrand factor (VWF) is crucial to hemostasis, but also plays a role in inflammatory processes. Unfortunately, no proper monoclonal antibodies to study VWF function in mice are currently available. We therefore aimed to generate single-domain antibodies (sdAbs) recognizing murine VWF and blocking its function in vivo. Llama-derived sdAbs recognizing both human and murine VWF were isolated via phage display technology. One of them (designated KB-VWF-006) recognized the VWF A1 domain with picomolar affinity. This sdAb avidity was strongly enhanced via dimerization using a triple Ala linker (KB-VWF-006bi). When administered in vivo to wild-type mice, KB-VWF-006bi dose dependently induced bleeding in a tail clip model. In 2 distinct models of inflammation, KB-VWF-006bi efficiently interfered with leukocyte recruitment and vascular leakage. KB-VWF-006bi is an sdAb recognizing the A1 domain of human VWF and murine VWF that interferes with VWF-platelet interactions in vivo. By using this sdAb, we now also show that the A1 domain is pertinent to the participation of VWF in the inflammatory response. © 2017 American Heart Association, Inc.

  7. Production in yeast of pseudotype virus-like particles harboring functionally active antibody fragments neutralizing the cytolytic activity of vaginolysin

    Directory of Open Access Journals (Sweden)

    Pleckaityte Milda

    2011-12-01

    Full Text Available Abstract Background Recombinant antibodies can be produced in different formats and different expression systems. Single chain variable fragments (scFvs represent an attractive alternative to full-length antibodies and they can be easily produced in bacteria or yeast. However, the scFvs exhibit monovalent antigen-binding properties and short serum half-lives. The stability and avidity of the scFvs can be improved by their multimerization or fusion with IgG Fc domain. The aim of the current study was to investigate the possibilities to produce in yeast high-affinity scFv-Fc proteins neutralizing the cytolytic activity of vaginolysin (VLY, the main virulence factor of Gardnerella vaginalis. Results The scFv protein derived from hybridoma cell line producing high-affinity neutralizing antibodies against VLY was fused with human IgG1 Fc domain. Four different variants of anti-VLY scFv-Fc fusion proteins were constructed and produced in yeast Saccharomyces cerevisiae. The non-tagged scFv-Fc and hexahistidine-tagged scFv-Fc proteins were found predominantly as insoluble aggregates and therefore were not suitable for further purification and activity testing. The addition of yeast α-factor signal sequence did not support secretion of anti-VLY scFv-Fc but increased the amount of its intracellular soluble form. However, the purified protein showed a weak VLY-neutralizing capability. In contrast, the fusion of anti-VLY scFv-Fc molecules with hamster polyomavirus-derived VP2 protein and its co-expression with VP1 protein resulted in an effective production of pseudotype virus-like particles (VLPs that exhibited strong VLY-binding activity. Recombinant scFv-Fc molecules displayed on the surface of VLPs neutralized VLY-mediated lysis of human erythrocytes and HeLa cells with high potency comparable to that of full-length antibody. Conclusions Recombinant scFv-Fc proteins were expressed in yeast with low efficiency. New approach to display the sc

  8. Performance Characteristics of Different Anti-Double-Stranded DNA Antibody Assays in the Monitoring of Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Michael Mahler

    2017-01-01

    Full Text Available Objective. We sought to evaluate different anti-double-stranded DNA assays for their performance characteristics in monitoring disease activity fluctuations in systemic lupus erythematosus (SLE. Methods. 36 active SLE patients were followed monthly. At each study visit (total n=371, blood was collected and disease activity was scored using the SELENA-SLEDAI (excluding anti-dsDNA or complement components and by a physician’s global assessment (PGA. Four anti-dsDNA tests were compared. Linear mixed-effects models with random intercept and fixed slopes were used to evaluate the relationship between the longitudinal fluctuations of disease activity and anti-dsDNA titers. Results. At enrollment, positivity for QUANTA Lite and high-avidity anti-dsDNA assay was both 64% and significantly lower than anti-dsDNA positivity by QUANTA Flash (83% and CLIFT (96%. Linear mixed-effects modeling indicated that the change in clinical SELENA-SLEDAI scores was associated with the titers of all anti-dsDNA with QUANTA Flash yielding the highest marginal R2 (0.15; p<0.01. QUANTA Flash was the only anti-dsDNA assay significantly associated with the change in PGA (marginal R2=0.05; p<0.01. Conclusion. These data indicate that anti-dsDNA antibodies determined by QUANTA Flash have a value in monitoring SLE disease activity.

  9. Influenza virus H1N1pdm09 infections in the young and old: evidence of greater antibody diversity and affinity for the hemagglutinin globular head domain (HA1 Domain) in the elderly than in young adults and children.

    Science.gov (United States)

    Verma, Nitin; Dimitrova, Milena; Carter, Donald M; Crevar, Corey J; Ross, Ted M; Golding, Hana; Khurana, Surender

    2012-05-01

    The H1N1 2009 influenza virus (H1N1pdm09) pandemic had several unexpected features, including low morbidity and mortality in older populations. We performed in-depth evaluation of antibody responses generated following H1N1pdm09 infection of naïve ferrets and of 130 humans ranging from the very young (0 to 9 years old) to the very old (70 to 89 years old). In addition to hemagglutination inhibition (HI) titers, we used H1N1pdm09 whole-genome-fragment phage display libraries (GFPDL) to evaluate the antibody repertoires against internal genes, hemagglutinin (HA), and neuraminidase (NA) and also measured antibody affinity for antigenic domains within HA. GFPDL analyses of H1N1pdm09-infected ferrets demonstrated gradual development of antibody repertoires with a focus on M1 and HA1 by day 21 postinfection. In humans, H1N1pdm09 infection in the elderly (>70 years old) induced antibodies with broader epitope recognition in both the internal genes and the HA1 receptor binding domain (RBD) than for the younger age groups (0 to 69 years). Importantly, post-H1N1 infection serum antibodies from the elderly demonstrated substantially higher avidity for recombinant HA1 (rHA1) (but not HA2) than those from younger subjects (50% versus elderly following H1N1pdm09 infection, indicative of recall of long-term memory B cells or long-lived plasma cells. These findings may help explain the age-related morbidity and mortality pattern observed during the H1N1pdm09 pandemic.

  10. Production of Monoclonal Antibody against Human Nestin

    OpenAIRE

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

    2010-01-01

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

  11. Improved monoclonal antibodies to halodeoxyuridine

    Science.gov (United States)

    Vanderlaan, M.; Dolbeare, F.A.; Gray, J.W.; Thomas, C.B.

    1983-10-18

    The development, method of production, characterization and methods of use of two hybridomas, CIdU-1 (ATCC Accession No. HB-8321) and CIdU-2 (ATCC Accession No. HB-8320), are described. These secrete IgG/sub 1/(K) immunoglobulins that react with halodeoxyuridine (HdU or halodU) such as bromo, chloro, fluoro and iodo deoxyuridine (BrdU, CldU, FdU and IdU), whether these are free in solution or incorporated into single stranded DNA in whole cells. The antibodies do not react with naturally occurring free nucleic acids or with deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) polymers. These antibodies are suitable for use in enzyme immunoassays for free CldU, FdU, IdU and BrdU and for detecting cells with these nucleotides incorporated into them. The monoclonal antibodies are useful in the detection of the sensitivity of tumor cells to specific chemotherapeutic agents, in the measurement of the rate of cellular DNA synthesis, in the measurement of the rate of proliferation of normal and malignant cells and in the detection of HPRT deficiency in cells. 1 tab.

  12. Six amino acid residues in a 1200 A2 interface mediate binding of factor VIII to an IgG4κ inhibitory antibody.

    Directory of Open Access Journals (Sweden)

    Jasper C Lin

    Full Text Available The development of neutralizing anti-factor VIII (FVIII antibodies complicates the treatment of many hemophilia A patients. The C-terminal C2 domain is a particularly antigenic FVIII region. A crystal structure of recombinant FVIII-C2 bound to an Fab fragment of the patient-derived monoclonal antibody BO2C11, which recognizes an immunodominant inhibitor epitope on FVIII and blocks its ability to bind von Willebrand factor (VWF and phospholipids, revealed that 15 amino acids in FVIII contact this antibody. Forty-three recombinant FVIII-C2 proteins, each with a surface-exposed side chain mutated to alanine or another residue, were generated, and surface plasmon resonance studies were carried out to evaluate effects of these substitutions on BO2C11/FVIII-C2 binding affinity. Thermodynamic analysis of experiments carried out at three temperatures indicated that one beta hairpin turn at the antigen-antibody interface (FVIII-F2196, N2198, M2199 and F2200 plus two non-contiguous arginines (FVIII-R2215 and R2220, contributed appreciably to the affinity. B-domain-deleted (BDD FVIII-F2196A, FVIII-F2196K and FVIII-M2199A were generated and characterized. Their pro-coagulant activities and binding to VWF were similar to those of WT-BDD-FVIII, and FVIII-F2196K avoided neutralization by BO2C11 and murine inhibitory mAb 1B5. This study suggests specific sites for amino acid substitutions to rationally design FVIII variants capable of evading immunodominant neutralizing anti-FVIII antibodies.

  13. Theranostic applications of antibodies in oncology.

    Science.gov (United States)

    Fleuren, Emmy D G; Versleijen-Jonkers, Yvonne M H; Heskamp, Sandra; van Herpen, Carla M L; Oyen, Wim J G; van der Graaf, Winette T A; Boerman, Otto C

    2014-06-01

    Targeted therapies, including antibodies, are becoming increasingly important in cancer therapy. Important limitations, however, are that not every patient benefits from a specific antibody therapy and that responses could be short-lived due to acquired resistance. In addition, targeted therapies are quite expensive and are not completely devoid of side-effects. This urges the need for accurate patient selection and response monitoring. An important step towards personalizing antibody treatment could be the implementation of theranostics. Antibody theranostics combine the diagnostic and therapeutic potential of an antibody, thereby selecting those patients who are most likely to benefit from antibody treatment. This review focuses on the clinical application of theranostic antibodies in oncology. It provides detailed information concerning the suitability of antibodies for theranostics, the different types of theranostic tests available and summarizes the efficacy of theranostic antibodies used in current clinical practice. Advanced theranostic applications, including radiolabeled antibodies for non-invasive functional imagining, are also addressed. Finally, we discuss the importance of theranostics in the emerging field of personalized medicine and critically evaluate recent data to determine the best way to apply antibody theranostics in the future. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  14. Application of Monoclonal Antibodies in Veterinary Parasitology

    Directory of Open Access Journals (Sweden)

    Gupta A.

    2011-08-01

    Full Text Available The discovery of hybridoma technology by Kohler and Milstein in 1975, heralded a new era in antibody research. Mouse hybridomas were the first reliable source of monoclonal antibodies. The generation of monoclonal antibodies from species other than rats and mice, has developed slowly over the last 30 years. The advent of antibody engineering and realization of the advantages of non murine antibodies has increased their relevance recently. However, in the area of veterinary parasitology, monoclonal antibodies are just beginning to fulfill the promises inherent in their great specificity for recognizing and selectively binding to antigens. This review describes the recent advances in the application of monoclonal antibodies for immunodiagnosis / prophylaxis and immunotherapy of parasitic diseases. [Vet. World 2011; 4(4.000: 183-188

  15. Acquired antibody responses against Plasmodium vivax infection vary with host genotype for duffy antigen receptor for chemokines (DARC.

    Directory of Open Access Journals (Sweden)

    Amanda Maestre

    2010-07-01

    Full Text Available Polymorphism of the Duffy Antigen Receptor for Chemokines (DARC is associated with susceptibility to and the severity of Plasmodium vivax malaria in humans. P. vivax uses DARC to invade erythrocytes. Individuals lacking DARC are 'resistant' to P. vivax erythrocytic infection. However, susceptibility to P. vivax in DARC+ individuals is reported to vary between specific DARC genotypes. We hypothesized that the natural acquisition of antibodies to P. vivax blood stages may vary with the host genotype and the level of DARC expression. Furthermore, high parasitemia has been reported to effect the acquisition of immunity against pre-erythrocytic parasites. We investigated the correlation between host DARC genotypes and the frequency and magnitude of antibodies against P. vivax erythrocytic stage antigens.We assessed the frequencies and magnitudes of antibody responses against P. vivax and P. falciparum sporozoite and erythrocytic antigens in Colombian donors from malaria-endemic regions. The frequency and level of naturally-acquired antibodies against the P. vivax erythrocytic antigens merozoite surface protein 1 (PvMSP1 and Duffy binding protein (PvDBP varied with the host DARC genotypes. Donors with one negative allele (FY*B/FY*Bnull and FY*A/FY*Bnull were more likely to have anti-PvMSP1 and anti-PvDBP antibodies than those with two positive alleles (FY*B/FY*B and FY*A/FY*B. The lower IgG3 and IgG1 components of the total IgG response may account for the decreased responses to P. vivax erythrocytic antigens with FY*A/FY*B and FY*B/FY*B genotypes. No such association was detected with P. falciparum erythrocytic antigens, which does not use DARC for erythrocyte invasion.Individuals with higher DARC expression, which is associated with higher susceptibility to P. vivax infection, exhibited low frequencies and magnitudes of P. vivax blood-stage specific antibody responses. This may indicate that one of the primary mechanisms by which P. vivax evades

  16. Clinical correlation of antimitochondrial antibodies.

    Science.gov (United States)

    Zuber, M A; Recktenwald, C

    2003-02-21

    Antimitochondrial antibodies (AMA) are a hallmark of primary biliary cirrhosis (PBC). They are believed to be absolutely disease specific. It does occur that patients with positive AMA are diagnosed with PBC in the absence of liver specific signs and symptoms. The aim of the present study was to examine the disease spectrum of unselected AMA positive patients of an university hospital. All of the AMA tests performed in the immunological laboratory of the hospital between 1992 and 1998 were examined for positivity. 100 patients with a positive result were analyzed retrospectively for diagnosis, clinical and laboratory features. 61 patients suffered from liver diseases and 39 from non-liver diseases. The patients with liver diseases were 36 patients with PBC, 2 patients with PBC/PSC-overlap syndrome, 4 patients with autoimmune hepatitis and 19 patients with different liver diseases of other than autoimmune origin. The 39 patients with non-liver diseases included 9 patients with systemic autoimmune diseases, 3 patients with organ-specific autoimmune diseases, 8 patients with carcinoma and 19 patients with different diseases. 97 patients had an ELISA test for antibodies to the mitochondrial antigen M2 performed in addition to the immunofluorescence test for AMA. 73 patients had positive values for anti-M2 antibodies and 24 patients had negative results. Anti-M2 antibody values were divided in negative, low (5-100 U/ml), medium (101-1000 U/ml), high (1001-10000 U/ml) and very high (>10000 U/ml). Very high and high anti-M2 values were present mainly in patients with PBC and some patients with other liver diseases, medium high and low values in patients with different disease groups. In this unselected patient population only one third of AMA positive patients had an established diagnosis of PBC, about 10% a diagnosis of a systemic autoimmune disease and 3 % had other organ-specific autoimmune diseases. It can be concluded that, although high titers of antibodies against

  17. Imaging of cutaneous T cell lymphoma (CTCL) with In-111-T101 monoclonal antibody

    Energy Technology Data Exchange (ETDEWEB)

    Carrasquillo, J.A.; Bunn, P.A.; Keenan, A.M.; Reynolds, J.C.; Schroff, R.W.; Foon, K.A.; Ming-Hsu, S.; Gazdar, A.F.; Mulshine, J.M.; Perentesis, P.

    1985-05-01

    T101 is a murine monoclonal antibody (MoAb), IgC2a, directed against a cell surface pan T-cell antigen present in high concentration in CTCL cells. In-111 labelling was performed with a modification of the Krejcarek method (Hybritech, Inc.). I mg of DTPA conjugated T101 was labeled with 5 mCi, with a mean incorporation of 95%. Immunoreactivity was preserved, mean 88%. In vivo, less than 3.6% of the injected dose was on circulating transferrin. 11 patients (pts) received 2-6h intravenous infusion of 1 mg (5 pts), 10 mg (3 pts), 50 mg (3 pts) of In-111 T101. By 24h all pts showed avid uptake in pathologically or clinically involved nodes and erythroderma including several previously unsuspected nodal regions. Skin plaques were not visualized. In addition, there was localization in liver, spleen and bone marrow. Concentration of In-111 in biopsied nodes was 0.01, 0.02 and 0.03% of the injected dose per gram. Control studies with In-111Cl/sub 3/ or a nonspecific MoAb, 9.2.27, did not concentrate in nodes or skin disease. No dose dependent differences in tumor localization was seen although blood clearance was prolonged for doses less than or equal to 10 mgs of T101. All pts receiving less than or equal to 10 mgs developed transient itching, urticaria and chills. 1 of 8 pts tested had an antimouse immune response. Modulation of the antigen from circulating T-cells, skin and nodes was seen. This study shows the feasibility of imaging CTCL pts with In-111 T101 and suggest a potential for radioimmunotherapy.

  18. Anti-rubella, Mumps and Measles IgG Antibodies in Medical Students of Tehran University.

    Science.gov (United States)

    Keshavarz, Maryam; Nicknam, Mohammad Hossein; Tebyanian, Majid; Shahkarami, Mohammad Kazem; Izad, Maryam

    2016-06-01

    Measles, mumps and rubella are viral infectious diseases that may result in serious complications. Since the production of vaccines, the number of cases of these diseases has been dropped. Nevertheless, these infectious diseases are still one of the major health problems in developing countries. In this study, in order to evaluate the protective responses against measles, mumps and rubella, the level and avidity of virus-specific IgG antibodies were measured in 53 medical students of Tehran University, aged between 20-30 years. Except for mumps vaccine, all the students had been vaccinated against measles and rubella according to Iran's nationwide mass vaccination protocol for all persons aged 5-25 in 2003. Our results showed that 96.2% of the volunteers had a protective level (>15 IU/ml) of IgG against rubella, 79.2% had a protective level (>11 IU/ml) of IgG against measles and 64.16% had a protective level (>11 IU/ml) of IgG against mumps. Over ten years after nationwide measles-rubella vaccination campaign, most young adults aged 20-30 had protective levels of humoral immunity against measles and rubella. However, Iranian young population is still unvaccinated against mumps, and therefore relatively large number of young adults had no protective level of IgG against it. This finding may be due to reduction in circulating of wild strain. We recommend screening of medical students for immunity against infectious agents such as measles, mumps, rubella, because they are at a high risk of these infectious agents.

  19. An MHC-restricted antibody-based chimeric antigen receptor requires TCR-like affinity to maintain antigen specificity

    Directory of Open Access Journals (Sweden)

    Marcela V Maus

    2016-01-01

    Full Text Available Chimeric antigen receptors (CARs are synthetic receptors that usually redirect T cells to surface antigens independent of human leukocyte antigen (HLA. Here, we investigated a T cell receptor-like CAR based on an antibody that recognizes HLA-A*0201 presenting a peptide epitope derived from the cancer-testis antigen NY-ESO-1. We hypothesized that this CAR would efficiently redirect transduced T cells in an HLA-restricted, antigen-specific manner. However, we found that despite the specificity of the soluble Fab, the same antibody in the form of a CAR caused moderate lysis of HLA-A2 expressing targets independent of antigen owing to T cell avidity. We hypothesized that lowering the affinity of the CAR for HLA-A2 would improve its specificity. We undertook a rational approach of mutating residues that, in the crystal structure, were predicted to stabilize binding to HLA-A2. We found that one mutation (DN lowered the affinity of the Fab to T cell receptor-range and restored the epitope specificity of the CAR. DN CAR T cells lysed native tumor targets in vitro, and, in a xenogeneic mouse model implanted with two human melanoma lines (A2+/NYESO+ and A2+/NYESO−, DN CAR T cells specifically migrated to, and delayed progression of, only the HLA-A2+/NY-ESO-1+ melanoma. Thus, although maintaining MHC-restricted antigen specificity required T cell receptor-like affinity that decreased potency, there is exciting potential for CARs to expand their repertoire to include a broad range of intracellular antigens.

  20. Therapeutic mechanism and efficacy of the antibody-drug conjugate BAY 79-4620 targeting human carbonic anhydrase 9.

    Science.gov (United States)

    Petrul, Heike M; Schatz, Christoph A; Kopitz, Charlotte C; Adnane, Lila; McCabe, Timothy J; Trail, Pamela; Ha, Sha; Chang, Yong S; Voznesensky, Andrei; Ranges, Gerald; Tamburini, Paul P

    2012-02-01

    Carbonic anhydrase IX (CAIX) is a cell surface glycoprotein that is expressed in many different tumors and yet restricted in normal tissues to the gastrointestinal tract. It is upregulated by hypoxia and correlates with tumor grade and poor survival in several tumor indications. Monoclonal antibodies (mAb) with single digit nanomolar binding affinity for CAIX were derived by panning with the recombinant ectodomain of CAIX against the MorphoSys HUCAL Gold library of human Fabs. Highest affinity Fabs were converted to full-length IgGs and subjected to further characterization based upon their avidity and selectivity for CAIX, their capacity to undergo internalization in CAIX-expressing cell lines, and their selective localization to CAIX-positive human xenografted tumors when administered to mice as fluorescent conjugates. Through this selection process, the 3ee9 mAb was identified, which upon conjugation to monomethyl auristatin E through a self-immolative enzyme-cleavable linker yielded the potent and selective CAIX antibody-drug conjugate CAIX-ADC (BAY 79-4620). In preclinical human xenograft models in mice representing several tumor indications, BAY 79-4620 showed potent antitumor efficacy and in some models showed partial and complete tumor shrinkage even following a single dose. The mechanism of action was shown by histology to involve the sequelae of events typical of antitubulin agents. Efficacy in murine preclinical models correlated semiquantitatively, with CAIX expression levels as determined by immunohistochemistry and ELISA. These preclinical data collectively support the development of BAY 79-4620 for the treatment of cancer patients with CAIX overexpressing tumors.

  1. Neutralising Antibodies against Ricin Toxin

    OpenAIRE

    Julie Prigent; Laetitia Panigai; Patricia Lamourette; Didier Sauvaire; Karine Devilliers; Marc Plaisance; Hervé Volland; Christophe Créminon; Stéphanie Simon

    2011-01-01

    The Centers for Disease Control and Prevention have listed the potential bioweapon ricin as a Category B Agent. Ricin is a so-called A/B toxin produced by plants and is one of the deadliest molecules known. It is easy to prepare and no curative treatment is available. An immunotherapeutic approach could be of interest to attenuate or neutralise the effects of the toxin. We sought to characterise neutralising monoclonal antibodies against ricin and to develop an effective therapy. For this pur...

  2. History of the antibody workshops.

    Science.gov (United States)

    Cohn, Melvin

    2017-11-02

    At a critical period in the history of contemporary immunology, a handful of biochemists and fringe immunologists formed a group known as the Antibody Workshop. They had a major impact on the field by attracting molecular biologists who worked to reduce the study of cellular and organ level immunology to the molecular level. This had a dramatic effect on the field both conceptually and practically by providing the targets for clinical manipulation. The story of the origin and development of this group over time is recounted here.

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

    Science.gov (United States)

    Kubczak, Małgorzata; Rogalińska, Małgorzata

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

  4. Conference scene: progress with promising human antibodies.

    Science.gov (United States)

    Larrick, James W

    2012-03-01

    Antibodies and antibody-based therapeutics have become big business, with annual sales over US$50 billion, accounting for >6% of worldwide pharmaceutical revenues. Ten molecules have blockbuster status (>US$1 billion), with six generating more than US$6 billion in sales. In excess of 300 products based on this rapidly maturing technology are in clinical trials. The generation and manufacture of human antibodies is now routine, although the cost of goods remains an issue. Optimizing combinations of antibodies with other therapeutics (e.g., chemotherapy) is a major short-term goal, while target validation and product differentiation remain significant hurdles if growth is to continue. Some of the notable highlights of the recent 16th International Conference on Human Antibodies and Hybridomas meeting in Cannes, France are described below. The conference was sponsored by the international journal Human Antibodies, in association with the Integrative Medical Sciences Association (IMSA). The Program Chairman was Professor Mark Glassy, IMSA, San Diego, CA, USA.

  5. Phase Separation in Solutions of Monoclonal Antibodies

    Science.gov (United States)

    Benedek, George; Wang, Ying; Lomakin, Aleksey; Latypov, Ramil

    2012-02-01

    We report the observation of liquid-liquid phase separation (LLPS) in a solution of humanized monoclonal antibodies, IgG2, and the effects of human serum albumin, a major blood protein, on this phase separation. We find a significant reduction of phase separation temperature in the presence of albumin, and a preferential partitioning of the albumin into the antibody-rich phase. We provide a general thermodynamic analysis of the antibody-albumin mixture phase diagram and relate its features to the magnitude of the effective inter-protein interactions. Our analysis suggests that additives (HSA in this report), which have moderate attraction with antibody molecules, may be used to forestall undesirable protein condensation in antibody solutions. Our findings are relevant to understanding the stability of pharmaceutical solutions of antibodies and the mechanisms of cryoglobulinemia.

  6. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, P. R.; Houen, G.

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  7. Targeting Malignant Brain Tumors with Antibodies

    OpenAIRE

    Rok Razpotnik; Neža Novak; Vladka Čurin Šerbec; Uros Rajcevic

    2017-01-01

    Antibodies have been shown to be a potent therapeutic tool. However, their use for targeting brain diseases, including neurodegenerative diseases and brain cancers, has been limited, particularly because the blood–brain barrier (BBB) makes brain tissue hard to access by conventional antibody-targeting strategies. In this review, we summarize new antibody therapeutic approaches to target brain tumors, especially malignant gliomas, as well as their potential drawbacks. Many different brain deli...

  8. Theranostic applications of antibodies in oncology

    OpenAIRE

    Fleuren, E.D.G.; Versleijen-Jonkers, Y.M.H.; Heskamp, S.; van Herpen, C M L; Oyen, W J G; van der Graaf, W T A; Boerman, O C

    2014-01-01

    Targeted therapies, including antibodies, are becoming increasingly important in cancer therapy. Important limitations, however, are that not every patient benefits from a specific antibody therapy and that responses could be short-lived due to acquired resistance. In addition, targeted therapies are quite expensive and are not completely devoid of side-effects. This urges the need for accurate patient selection and response monitoring. An important step towards personalizing antibody treatme...

  9. Monoclonal antibodies to immunodeterminants of lipoteichoic acids.

    Science.gov (United States)

    Jackson, D E; Wong, W; Largen, M T; Shockman, G D

    1984-03-01

    Murine hybrid cell lines producing monoclonal antibodies directed against determinants present on lipoteichoic acids were generated. Hapten inhibition studies showed that one group of monoclonal antibodies was inhibited by deacylated cardiolipin, and the second group was inhibited by kojibiose. Thus, antibodies directed against the polyglycerophosphate chain, which is common to the lipoteichoic acids of many gram-positive species, and against the streptococcal group D antigen were obtained.

  10. Monoclonal antibodies to immunodeterminants of lipoteichoic acids.

    OpenAIRE

    Jackson, D E; Wong, W; Largen, M T; Shockman, G. D.

    1984-01-01

    Murine hybrid cell lines producing monoclonal antibodies directed against determinants present on lipoteichoic acids were generated. Hapten inhibition studies showed that one group of monoclonal antibodies was inhibited by deacylated cardiolipin, and the second group was inhibited by kojibiose. Thus, antibodies directed against the polyglycerophosphate chain, which is common to the lipoteichoic acids of many gram-positive species, and against the streptococcal group D antigen were obtained.

  11. Warm antibody autoimmune hemolytic anemia.

    Science.gov (United States)

    Kalfa, Theodosia A

    2016-12-02

    Autoimmune hemolytic anemia (AIHA) is a rare and heterogeneous disease that affects 1 to 3/100 000 patients per year. AIHA caused by warm autoantibodies (w-AIHA), ie, antibodies that react with their antigens on the red blood cell optimally at 37°C, is the most common type, comprising ∼70% to 80% of all adult cases and ∼50% of pediatric cases. About half of the w-AIHA cases are called primary because no specific etiology can be found, whereas the rest are secondary to other recognizable underlying disorders. This review will focus on the postulated immunopathogenetic mechanisms in idiopathic and secondary w-AIHA and report on the rare cases of direct antiglobulin test-negative AIHA, which are even more likely to be fatal because of inherent characteristics of the causative antibodies, as well as because of delays in diagnosis and initiation of appropriate treatment. Then, the characteristics of w-AIHA associated with genetically defined immune dysregulation disorders and special considerations on its management will be discussed. Finally, the standard treatment options and newer therapeutic approaches for this chronic autoimmune blood disorder will be reviewed. © 2016 by The American Society of Hematology. All rights reserved.

  12. Snake venom antibodies in Ecuadorian Indians.

    Science.gov (United States)

    Theakston, R D; Reid, H A; Larrick, J W; Kaplan, J; Yost, J A

    1981-10-01

    Serum samples from 223 Waorani Indians, a tribe in eastern Ecuador, were investigated by enzyme-linked immunosorbent assay for antibodies to snake venom. Seventy-eight per cent were positive, confirming the highest incidence and mortality from snake bite poisoning yet recorded in the world. Most samples were positive for more than one venom antibody. Antibodies were found to venoms of Bothrops viper in 60% of positive cases, of Micrurus coral snake in 21%, and of the bushmaster, Lachesis muta, in 18%. Further studies are needed to determine whether high venom-antibody levels afford protection against further snake envenoming.

  13. Antiphospholipid antibody: laboratory, pathogenesis and clinical manifestations

    OpenAIRE

    T. Ziglioli; S. Cartella; Casu, C.; Tincani, A; Cattaneo, R

    2011-01-01

    Antiphospholipid antibodies (aPL) represent a heterogeneous group of antibodies that recognize various antigenic targets including beta2 glycoprotein I (β2GPI), prothrombin (PT), activated protein C, tissue plasminogen activator, plasmin and annexin A2. The most commonly used tests to detect aPL are: lupus anticoagulant (LAC), a functional coagulation assay, anticardiolipin antibody (aCL) and anti-β2GPI antibody (anti-β2GPI), which are enzyme-linked immunoassay (ELISA). Clinically aPL are ass...

  14. Onconeural Antibodies in Acute Psychiatric Inpatient Care

    DEFF Research Database (Denmark)

    Sæther, Sverre Georg; Schou, Morten; Stoecker, Winfried

    2017-01-01

    Paraneoplastic neurological disorders associated with onconeural antibodies often appear with neuropsychiatric symptoms. To study the prevalence of onconeural antibodies in patients admitted to acute psychiatric inpatient care, the serum of 585 such patients was tested for antibodies targeting MOG......, GLRA1B, DPPX, GRM1, GRM5, DNER, Yo, ZIC4, GAD67, amphiphysin, CV2, Hu, Ri, Ma2, and recoverin. Only one sample was positive (antirecoverin IgG). The present findings suggest that serum onconeural antibody positivity is rare among patients acutely admitted for inpatient psychiatric care. The clinical...

  15. Exceptional Antibodies Produced by Successive Immunizations.

    Directory of Open Access Journals (Sweden)

    Patricia J Gearhart

    2015-12-01

    Full Text Available Antibodies stand between us and pathogens. Viruses mutate quickly to avoid detection, and antibodies mutate at similar rates to hunt them down. This death spiral is fueled by specialized proteins and error-prone polymerases that change DNA sequences. Here, we explore how B lymphocytes stay in the race by expressing activation-induced deaminase, which unleashes a tsunami of mutations in the immunoglobulin loci. This produces random DNA substitutions, followed by selection for the highest affinity antibodies. We may be able to manipulate the process to produce better antibodies by expanding the repertoire of specific B cells through successive vaccinations.

  16. Exceptional Antibodies Produced by Successive Immunizations.

    Science.gov (United States)

    Gearhart, Patricia J; Castiblanco, Diana P; Russell Knode, Lisa M

    2015-12-01

    Antibodies stand between us and pathogens. Viruses mutate quickly to avoid detection, and antibodies mutate at similar rates to hunt them down. This death spiral is fueled by specialized proteins and error-prone polymerases that change DNA sequences. Here, we explore how B lymphocytes stay in the race by expressing activation-induced deaminase, which unleashes a tsunami of mutations in the immunoglobulin loci. This produces random DNA substitutions, followed by selection for the highest affinity antibodies. We may be able to manipulate the process to produce better antibodies by expanding the repertoire of specific B cells through successive vaccinations.

  17. Antiphospholipid antibodies among women experiencing fetal loss

    National Research Council Canada - National Science Library

    Ching, Y M; Arip, M; Jegasothy, R; Baskaran, T P; Yusof, A Y; Bakhtiar, F; Mustafa, N

    2013-01-01

    The presence of antiphospholipid antibodies (aPLs) is closely associated with thrombotic events and pregnancy complications such as recurrent pregnancy loss, preeclampsia and placental insufficiency...

  18. Mean Recency Period for Estimation of HIV-1 Incidence with the BED-Capture EIA and Bio-Rad Avidity in Persons Diagnosed in the United States with Subtype B.

    Science.gov (United States)

    Hanson, Debra L; Song, Ruiguang; Masciotra, Silvina; Hernandez, Angela; Dobbs, Trudy L; Parekh, Bharat S; Owen, S Michele; Green, Timothy A

    2016-01-01

    HIV incidence estimates are used to monitor HIV-1 infection in the United States. Use of laboratory biomarkers that distinguish recent from longstanding infection to quantify HIV incidence rely on having accurate knowledge of the average time that individuals spend in a transient state of recent infection between seroconversion and reaching a specified biomarker cutoff value. This paper describes five estimation procedures from two general statistical approaches, a survival time approach and an approach that fits binomial models of the probability of being classified as recently infected, as a function of time since seroconversion. We compare these procedures for estimating the mean duration of recent infection (MDRI) for two biomarkers used by the U.S. National HIV Surveillance System for determination of HIV incidence, the Aware BED EIA HIV-1 incidence test (BED) and the avidity-based, modified Bio-Rad HIV-1/HIV-2 plus O ELISA (BRAI) assay. Collectively, 953 specimens from 220 HIV-1 subtype B seroconverters, taken from 5 cohorts, were tested with a biomarker assay. Estimates of MDRI using the non-parametric survival approach were 198.4 days (SD 13.0) for BED and 239.6 days (SD 13.9) for BRAI using cutoff values of 0.8 normalized optical density and 30%, respectively. The probability of remaining in the recent state as a function of time since seroconversion, based upon this revised statistical approach, can be applied in the calculation of annual incidence in the United States.

  19. Mean Recency Period for Estimation of HIV-1 Incidence with the BED-Capture EIA and Bio-Rad Avidity in Persons Diagnosed in the United States with Subtype B.

    Directory of Open Access Journals (Sweden)

    Debra L Hanson

    Full Text Available HIV incidence estimates are used to monitor HIV-1 infection in the United States. Use of laboratory biomarkers that distinguish recent from longstanding infection to quantify HIV incidence rely on having accurate knowledge of the average time that individuals spend in a transient state of recent infection between seroconversion and reaching a specified biomarker cutoff value. This paper describes five estimation procedures from two general statistical approaches, a survival time approach and an approach that fits binomial models of the probability of being classified as recently infected, as a function of time since seroconversion. We compare these procedures for estimating the mean duration of recent infection (MDRI for two biomarkers used by the U.S. National HIV Surveillance System for determination of HIV incidence, the Aware BED EIA HIV-1 incidence test (BED and the avidity-based, modified Bio-Rad HIV-1/HIV-2 plus O ELISA (BRAI assay. Collectively, 953 specimens from 220 HIV-1 subtype B seroconverters, taken from 5 cohorts, were tested with a biomarker assay. Estimates of MDRI using the non-parametric survival approach were 198.4 days (SD 13.0 for BED and 239.6 days (SD 13.9 for BRAI using cutoff values of 0.8 normalized optical density and 30%, respectively. The probability of remaining in the recent state as a function of time since seroconversion, based upon this revised statistical approach, can be applied in the calculation of annual incidence in the United States.

  20. High throughput discovery of influenza virus neutralizing antibodies from phage-displayed synthetic antibody libraries.

    Science.gov (United States)

    Chen, Ing-Chien; Chiu, Yi-Kai; Yu, Chung-Ming; Lee, Cheng-Chung; Tung, Chao-Ping; Tsou, Yueh-Liang; Huang, Yi-Jen; Lin, Chia-Lung; Chen, Hong-Sen; Wang, Andrew H-J; Yang, An-Suei

    2017-10-31

    Pandemic and epidemic outbreaks of influenza A virus (IAV) infection pose severe challenges to human society. Passive immunotherapy with recombinant neutralizing antibodies can potentially mitigate the threats of IAV infection. With a high throughput neutralizing antibody discovery platform, we produced artificial anti-hemagglutinin (HA) IAV-neutralizing IgGs from phage-displayed synthetic scFv libraries without necessitating prior memory of antibody-antigen interactions or relying on affinity maturation essential for in vivo immune systems to generate highly specific neutralizing antibodies. At least two thirds of the epitope groups of the artificial anti-HA antibodies resemble those of natural protective anti-HA antibodies, providing alternatives to neutralizing antibodies from natural antibody repertoires. With continuing advancement in designing and constructing synthetic scFv libraries, this technological platform is useful in mitigating not only the threats of IAV pandemics but also those from other newly emerging viral infections.

  1. An efficient method for isolating antibody fragments against small peptides by antibody phage display

    DEFF Research Database (Denmark)

    Duan, Zhi; Siegumfeldt, Henrik

    2010-01-01

    We generated monoclonal scFv (single chain variable fragment) antibodies from an antibody phage display library towards three small synthetic peptides derived from the sequence of s1-casein. Key difficulties for selection of scFv-phages against small peptides were addressed. Small peptides do....... The scFvs were sequenced and characterized, and specificity was characterized by ELISA. The methods developed in this study are universally applicable for antibody phage display to efficiently produce antibody fragments against small peptides....

  2. Human anti-Dectin-1 antibody, hybridoma producing said antibody and applications thereof

    OpenAIRE

    Kremer, Leonor; Llorente Gómez, María de las Mercedes; Casasnovas, José María; Fernández Ruíz, Elena; Galán Díez, Marta

    2008-01-01

    [EN] The invention relates to hybridoma MGD3 and the monoclonal antibody produced thereby (also called MGD3), which specifically recognises the human Dectin-1 membrane receptor. Antibody MGD3 is capable of inhibiting the binding of Dectin-1 to the natural ligand thereof, the ss-glucans that are components of the fungal wall. In addition, the aforementioned antibody specifically blocks binding to Candida albicans and the secretion of cytokines induced thereby. The MGD3 antibody obtained enable...

  3. Similar Idiotypes in Antibody-Forming Cells and in Cells Synthesizing Immunoglobulins Without Detectable Antibody Function

    Science.gov (United States)

    Cazenave, P. -A.; Ternynck, T.; Avrameas, S.

    1974-01-01

    The occurrence of immunoglobulins with and without antibody specificity and with and without idiotypic specificity was studied, by use of enzyme-labeled antigen and antibodies, in lymph node cells of rabbits immunized with horse-radish peroxidase and hen ovalbumin. Some cells, containing immunoglobulins without detectable antibody function, were shown to contain idiotypes similar to those found in antibody-producing cells. PMID:4140504

  4. Blocking Synthesis of the Variant Surface Glycoprotein Coat in Trypanosoma brucei Leads to an Increase in Macrophage Phagocytosis Due to Reduced Clearance of Surface Coat Antibodies.

    Directory of Open Access Journals (Sweden)

    Jackie L Y Cheung

    2016-11-01

    Full Text Available The extracellular bloodstream form parasite Trypanosoma brucei is supremely adapted to escape the host innate and adaptive immune system. Evasion is mediated through an antigenically variable Variant Surface Glycoprotein (VSG coat, which is recycled at extraordinarily high rates. Blocking VSG synthesis triggers a precytokinesis arrest where stalled cells persist for days in vitro with superficially intact VSG coats, but are rapidly cleared within hours in mice. We therefore investigated the role of VSG synthesis in trypanosome phagocytosis by activated mouse macrophages. T. brucei normally effectively evades macrophages, and induction of VSG RNAi resulted in little change in phagocytosis of the arrested cells. Halting VSG synthesis resulted in stalled cells which swam directionally rather than tumbling, with a significant increase in swim velocity. This is possibly a consequence of increased rigidity of the cells due to a restricted surface coat in the absence of VSG synthesis. However if VSG RNAi was induced in the presence of anti-VSG221 antibodies, phagocytosis increased significantly. Blocking VSG synthesis resulted in reduced clearance of anti-VSG antibodies from the trypanosome surface, possibly as a consequence of the changed motility. This was particularly marked in cells in the G2/ M cell cycle stage, where the half-life of anti-VSG antibody increased from 39.3 ± 4.2 seconds to 99.2 ± 15.9 seconds after induction of VSG RNAi. The rates of internalisation of bulk surface VSG, or endocytic markers like transferrin, tomato lectin or dextran were not significantly affected by the VSG synthesis block. Efficient elimination of anti-VSG-antibody complexes from the trypanosome cell surface is therefore essential for trypanosome evasion of macrophages. These experiments highlight the essentiality of high rates of VSG recycling for the rapid removal of host opsonins from the parasite surface, and identify this process as a key parasite

  5. Antibody formation and mannose-6-phosphate receptor expression impact the efficacy of muscle-specific transgene expression in murine Pompe disease

    Science.gov (United States)

    Sun, Baodong; Li, Songtao; Bird, Andrew; Yi, Haiqing; Kemper, Alex; Koeberl, Dwight D.

    2013-01-01

    BACKGROUND Lysosomal storage disorders such as Pompe disease can be more effectively treated, if immune tolerance to enzyme or gene replacement therapy can be achieved. Alternatively, immune responses against acid α-glucosidase (GAA) might be evaded in Pompe disease through muscle-specific expression of GAA with adeno-associated virus (AAV) vectors. METHODS An AAV vector containing the MHCK7 regulatory cassette to drive muscle-specific GAA expression was administered to GAA knockout (KO) mice, immune tolerant GAA-KO mice, and mannose-6-phosphate deficient GAA-KO mice. GAA activity and glycogen content were analyzed in striated muscle to determine biochemical efficacy. RESULTS The biochemical efficacy from GAA expression was slightly reduced in GAA-KO mice, as demonstrated by higher residual glycogen content in skeletal muscles. Next immune tolerance to GAA was induced in GAA-KO mice by co-administration of a second AAV vector encoding liver-specific GAA along with the AAV vector encoding muscle-specific GAA. Antibody formation was prevented by liver-specific GAA, and the biochemical efficacy of GAA expression was improved in absence of antibodies as evidenced by significantly reduced glycogen content in the diaphragm. Efficacy was reduced in old GAA-KO mice despite the absence of antibodies. The greatest impact upon gene therapy was observed in GAA-KO mice lacking the mannose-6-phosphate receptor in muscle. The clearance of stored glycogen was markedly impaired despite high GAA expression in receptor-deficient Pompe disease mice. CONCLUSIONS Overall, antibody formation had a subtle effect upon efficacy, while the absence of mannose-6-phosphate receptors markedly impaired muscle-targeted gene therapy in murine Pompe disease. PMID:20967919

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  7. 21 CFR 866.3290 - Gonococcal antibody test (GAT).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gonococcal antibody test (GAT). 866.3290 Section... antibody test (GAT). (a) Identification. A gonococcal antibody test (GAT) is an in vitro device that..., indirect fluorescent antibody, or radioimmunoassay, antibodies to Neisseria gonorrhoeae in sera of...

  8. Antibody Characterization Process | Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    The goal of the NCI's Antibody Characterization Program (ACP) is to have three monoclonal antibodies produced for each successfully expressed/purified recombinant antigen and one antibody per peptide (1 to 3 peptides per protein). To date, over 4000 clones have been screened before selecting the current 393 antibodies. They are winnowed down based on the projected end use of the antibody.

  9. Antibody humanization methods for development of therapeutic applications.

    Science.gov (United States)

    Ahmadzadeh, Vahideh; Farajnia, Safar; Feizi, Mohammad Ali Hosseinpour; Nejad, Ramezan Ali Khavari

    2014-04-01

    Recombinant antibody technologies are rapidly becoming available and showing considerable clinical success. However, the immunogenicity of murine-derived monoclonal antibodies is restrictive in cancer immunotherapy. Humanized antibodies can overcome these problems and are considered to be a promising alternative therapeutic agent. There are several approaches for antibody humanization. In this article we review various methods used in the antibody humanization process.

  10. Monoclonal antibodies in pediatric allergy

    Directory of Open Access Journals (Sweden)

    Amelia Licari

    2015-10-01

    Full Text Available Production of monoclonal antibodies (mAbs involving human-mouse hybrid cells was first described in 1970s, but these biologics are now used for a variety of diseases including cancers, autoimmune disorders and allergic diseases. The aim of this article is to review current and future applications of mAbs, in particular focusing on anti-IgE therapy, in the field of pediatric allergy. Proceedings of the 11th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy · October 26th-31st, 2015 · From the womb to the adultGuest Editors: Vassilios Fanos (Cagliari, Italy, Michele Mussap (Genoa, Italy, Antonio Del Vecchio (Bari, Italy, Bo Sun (Shanghai, China, Dorret I. Boomsma (Amsterdam, the Netherlands, Gavino Faa (Cagliari, Italy, Antonio Giordano (Philadelphia, USA

  11. Detection Of Haemagglutination–Inhibition Antibodies Against ...

    African Journals Online (AJOL)

    A survey of haemagglutination inhibition (HI) antibodies against influenza A virus was carried out on pigs sera collected at Bodija abattoir, Ibadan between December, 2001 and August 2002. Out of the 107 sera tested, 101 (94.39%) had HI antibodies to influenza A (H1N1) human strain while the remaining 6 (5.61%) were ...

  12. Quantitative Changes In Antibodies Against Onchocercal Native ...

    African Journals Online (AJOL)

    Serum antibodies to Onchocerca volvulus native sodium duodecylsulphate slat extracted antigens and epitopes recognized by three monoclonal antibodies designated Cam8, Cam22, and Cam28 were measured using indirect (sandwich) and competitive enzyme-linked immunosorbent assay (ELISA). Paired serum ...

  13. The Relationship between Antisperm Antibodies Prevalence and ...

    African Journals Online (AJOL)

    Erah

    17. Bohring C and Krause W (2003b): Characterization of spermatozoa surface antigens by antisperm antibodies and its influence on acrosomal exocytosis. AJRI.; 50: 411–419. 18. Bohring C and Krause W (2005): The role of antisperm antibodies during fertilization and for immunological infertility Chem Immunol Allergy.;.

  14. Monoclonal Antibody Therapy for Advanced Neuroblastoma

    Science.gov (United States)

    NCI is sponsoring two clinical trials of a monoclonal antibody called ch14.18, in combination with other drugs, to see if the antibody may be helpful for children or young adults (up to age 21) with relapsed or refractory neuroblastoma.

  15. Antibody-drug conjugates: Intellectual property considerations.

    Science.gov (United States)

    Storz, Ulrich

    2015-01-01

    Antibody-drug conjugates are highly complex entities that combine an antibody, a linker and a toxin. This complexity makes them demanding both technically and from a regulatory point of view, and difficult to deal with in their patent aspects. This article discusses different issues of patent protection and freedom to operate with regard to this promising new class of drugs.

  16. Anti-influenza M2e antibody

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM

    2011-12-20

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

  17. Anti-influenza M2e antibody

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M.

    2013-04-16

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

  18. Receptor antibodies as novel therapeutics for diabetes

    DEFF Research Database (Denmark)

    Ussar, Siegfried; Vienberg, Sara Gry; Kahn, C Ronald

    2011-01-01

    Antibodies to receptors can block or mimic hormone action. Taking advantage of receptor isoforms, co-receptors, and other receptor modulating proteins, antibodies and other designer ligands can enhance tissue specificity and provide new approaches to the therapy of diabetes and other diseases....

  19. Monoclonal antibodies reactive with hairy cell leukemia

    NARCIS (Netherlands)

    Visser, L; Shaw, A; Slupsky, J; Vos, H; Poppema, S

    Monoclonal antibodies reactive with hairy cell leukemia were developed to aid in the diagnosis of this subtype of B cell chronic lymphocytic leukemia and to gain better insight into the origin of hairy cells. Three antibodies were found to be of value in the diagnosis of hairy cell leukemia.

  20. Antibody-drug conjugates in cancer

    NARCIS (Netherlands)

    Goeij, Bart Egbertus Cornelis Gijsbertus de

    2016-01-01

    Antibody drug conjugates (ADCs) are emerging as powerful anti-cancer treatments. They are designed to combine the tumor specificity, pharmacokinetics and biodistribution properties of antibodies with the potent cell-killing activity of small molecules. The approval of brentuximab vedotin (Adcetris)

  1. Antibody biotechnology | Benjouad | African Journal of Biotechnology

    African Journals Online (AJOL)

    (mAbs) have continuously stimulated the development of antibody engineering especially after the discovery hybridoma by Köhler and Milstein (1975). This review summarize the main antibody biotechnology approaches that have lead to the development of murine mAbs, chimeric mAbs, humanized mAbs , combinatorial ...

  2. Antibody humanization methods - a review and update.

    Science.gov (United States)

    Safdari, Yaghoub; Farajnia, Safar; Asgharzadeh, Mohammad; Khalili, Masoumeh

    2013-01-01

    This article reviews recent advances achieved during recent years on various aspects of antibody humanization theories and techniques. Common methods for producing humanized antibodies including framework-homology-based humanization, germline humanization, complementary determining regions (CDR)-homology-based humanization and specificity determining residues (SDR) grafting, as well as advantages and disadvantages of each of these methods and their applications are discussed.

  3. Theranostic applications of antibodies in oncology

    NARCIS (Netherlands)

    Fleuren, E.D.G.; Versleijen-Jonkers, Y.M.H.; Heskamp, S.; Herpen, C.M.L. van; Oyen, W.J.G.; Graaf, W.T.A. van der; Boerman, O.C.

    2014-01-01

    Targeted therapies, including antibodies, are becoming increasingly important in cancer therapy. Important limitations, however, are that not every patient benefits from a specific antibody therapy and that responses could be short-lived due to acquired resistance. In addition, targeted therapies

  4. Photonic crystal fiber based antibody detection

    DEFF Research Database (Denmark)

    Duval, A; Lhoutellier, M; Jensen, J B

    2004-01-01

    An original approach for detecting labeled antibodies based on strong penetration photonic crystal fibers is introduced. The target antibody is immobilized inside the air-holes of a photonic crystal fiber and the detection is realized by the means of evanescent-wave fluorescence spectroscopy...

  5. Epstein-Barr Virus Antibodies Test

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Epstein-Barr Virus (EBV) Antibody Tests Send Us Your Feedback ... Antigen D, EA-D IgG Ab Formal Name Epstein-Barr Virus Antibodies This article was last reviewed on ...

  6. Preparation and identification of monoclonal antibodies against ...

    African Journals Online (AJOL)

    Yomi

    The hybridoma cell lines were screened for HN-specific antibodies by indirect enzyme-linked immunosorbent assay (ELISA), and anti-HN mAb-producing hybridoma clones were obtained using a limiting dilution assay. The specificity and affinity of the antibodies were characterized by western blot assays and indirect ELISA ...

  7. ANTI-SULFATIDE ANTIBODIES IN PERIPHERAL NEUROPATHY

    NARCIS (Netherlands)

    VANDENBERG, LH; LANKAMP, CLAM; DEJAGER, AEJ; NOTERMANS, NC; SODAAR, P; MARRINK, J; DEJONG, HJ; BAR, PR; WOKKE, JHJ

    1993-01-01

    A study was carried out on 135 patients with chronic idiopathic neuropathy (63), neuropathy associated with monoclonal gammopathy (51, including eight with anti-MAG antibody activity) and the Guillain-Barre syndrome (GBS) (21). Serum IgM, IgG and IgA anti-sulphatide antibody titres were compared

  8. Antiphospholipid antibody: laboratory, pathogenesis and clinical manifestations

    Directory of Open Access Journals (Sweden)

    T. Ziglioli

    2011-06-01

    Full Text Available Antiphospholipid antibodies (aPL represent a heterogeneous group of antibodies that recognize various antigenic targets including beta2 glycoprotein I (β2GPI, prothrombin (PT, activated protein C, tissue plasminogen activator, plasmin and annexin A2. The most commonly used tests to detect aPL are: lupus anticoagulant (LAC, a functional coagulation assay, anticardiolipin antibody (aCL and anti-β2GPI antibody (anti-β2GPI, which are enzyme-linked immunoassay (ELISA. Clinically aPL are associated with thrombosis and/or with pregnancy morbidity. Apparently aPL alone are unable to induce thrombotic manifestations, but they increase the risk of vascular events that can occur in the presence of another thrombophilic condition; on the other hand obstetrical manifestations were shown to be associated not only to thrombosis but mainly to a direct antibody effect on the trophoblast.

  9. Antibodies against chromosomal beta-lactamase

    DEFF Research Database (Denmark)

    Giwercman, B; Rasmussen, J W; Ciofu, Oana

    1994-01-01

    A murine monoclonal anti-chromosomal beta-lactamase antibody was developed and an immunoblotting technique was used to study the presence of serum and sputum antibodies against Pseudomonas aeruginosa chromosomal group 1 beta-lactamase in patients with cystic fibrosis (CF). The serum antibody...... response was studied with serum samples collected in 1992 from 56 CF patients in a cross-sectional study and with serum samples from 18 CF patients in a longitudinal study. Anti-beta-lactamase immunoglobulin G antibodies were present in all of the serum samples from the patients with chronic...... bronchopulmonary P. aeruginosa infection (CF + P) but in none of the CF patients with no or intermittent P. aeruginosa infection. Anti-beta-lactamase antibodies were present in serum from CF + P patients after six antipseudomonal courses (median) and correlated with infection with a beta-lactam-resistant strain...

  10. Monoclonal antibodies in chronic lymphocytic leukemia.

    Science.gov (United States)

    Ferrajoli, Alessandra; Faderl, Stefan; Keating, Michael J

    2006-09-01

    Multiple options are now available for the treatment of chronic lymphocytic leukemia. Over the last 10 years, monoclonal antibodies have become an integral part of the management of this disease. Alemtuzumab has received approval for use in patients with fludarabine-refractory chronic lymphocytic leukemia. Rituximab has been investigated extensively in chronic lymphocytic leukemia both as a single agent and in combination with chemotherapy and other monoclonal antibodies. Epratuzumab and lumiliximab are newer monoclonal antibodies in the early phase of clinical development. This article will review the monoclonal antibodies more commonly used to treat chronic lymphocytic leukemia, the results obtained with monoclonal antibodies as single agents and in combination with chemotherapy, and other biological agents and newer compounds undergoing clinical trials.

  11. Isolation of Balamuthia mandrillaris-specific antibody fragments from a bacteriophage antibody display library.

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Kulsoom, Huma; Lalani, Salima; Khan, Naveed Ahmed

    2016-07-01

    Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a mortality rate of more than 95%. Early diagnosis followed by aggressive treatment is a pre-requisite for successful prognosis. Current methods for identifying this organism rely on culture and microscopy, antibody-based methods using animals, or involve the use of molecular tools that are expensive. Here, we describe the isolation of antibody fragments that can be used for the unequivocal identification of B. mandrillaris. B. mandrillaris-specific antibody fragments were isolated from a bacteriophage antibody display library. Individual clones were studied by enzyme-linked immunosorbent assay, and immunofluorescence. Four antibody clones showed specific binding to B. mandrillaris. The usefulness of phage antibody display technology as a diagnostic tool for isolating antibody fragments against B. mandrillaris antigens and studying their biological role(s) is discussed further. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2013-06-26

    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 as immunoglobulins (Ig)G in many immunoassays. In contrast, the bivalent scFv-Fc antibody format shares many properties with IgG and has a very high application compatibility. In this study transient expression of scFv-Fc antibodies in human embryonic kidney (HEK) 293 cells was optimized. Production levels of 10-20 mg/L scFv-Fc antibody were achieved in adherent HEK293T cells. Employment of HEK293-6E suspension cells expressing a truncated variant of the Epstein Barr virus (EBV) nuclear antigen (EBNA) 1 in combination with production under serum free conditions increased the volumetric yield up to 10-fold to more than 140 mg/L scFv-Fc antibody. After vector optimization and process optimization the yield of an scFv-Fc antibody and a cytotoxic antibody-RNase fusion protein further increased 3-4-fold to more than 450 mg/L. Finally, an entirely new mammalian expression vector was constructed for single step in frame cloning of scFv genes from antibody phage display libraries. Transient expression of more than 20 different scFv-Fc antibodies resulted in volumetric yields of up to 600 mg/L and 400 mg/L in average. Transient production of recombinant scFv-Fc antibodies in HEK293-6E in combination with optimized vectors and fed batch shake flasks cultivation is efficient and robust, and integrates well into a high-throughput recombinant antibody generation pipeline.

  13. DARPA ANTIBODY TECHNOLOGY PROGRAM STANDARDIZED TEST BED FOR ANTIBODY CHARACTERIZATION: CHARACTERIZATION OF TWO MS2 SCFV ANTIBODIES PRODUCED BY THE UNIVERSITY OF TEXAS

    Science.gov (United States)

    2017-05-01

    ECBC-TR-1434 DARPA ANTIBODY TECHNOLOGY PROGRAM STANDARDIZED TEST BED FOR...COVERED (From - To) Oct 2010 – Sep 2012 4. TITLE AND SUBTITLE DARPA Antibody Technology Program Standardized Test Bed for Antibody Characterization...Characterization of Two MS2 scFv Antibodies Produced by the University of Texas 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  14. Contribution to antimitochondrial antibody production: cleavage of pyruvate dehydrogenase complex-E2 by apoptosis-related proteases.

    Science.gov (United States)

    Matsumura, Shuji; Van De Water, Judy; Kita, Hiroto; Coppel, Ross L; Tsuji, Takao; Yamamoto, Kazuhide; Ansari, Aftab A; Gershwin, M Eric

    2002-01-01

    Patients with PBC produce a directed, specific response to a single immunodominant autoepitope of PDC-E2 within the inner lipoyl domain. In contrast, immunized animals react to multiple epitopes and rarely recognize the inner lipoyl domain. In other autoimmune diseases, apoptosis plays a critical role in antigen presentation; the caspases and granzyme B are the key proteases in the generation of autoepitopes. To determine the specific cleavage pattern of full-length recombinant PDC-E2, we performed in vitro digestion with caspases-3, -6, -8 and granzyme B. The resulting fragments were immunoblotted and probed with an extensive panel of monoclonal anti-PDC-E2 antibodies and sera from patients with PBC. Interestingly, on granzyme B digestion, PDC-E2 lost reactivity, suggesting the destruction of the immunodominant epitope. Because this site contains the major epitope for both B cells and T cells, it suggests that granzyme B is unlikely to be involved in generation of autoepitopes in primary biliary cirrhosis (PBC). In contrast, following treatment with the caspase enzymes, immunoreactive fragments were generated. Indeed, by confocal microscopy, activated caspase-3 is found in the marginal hepatocytes and bile ducts. Moreover, caspase-3 staining was strongest in the small intrahepatic bile ducts, the major site of tissue destruction in PBC. In conclusion, these data suggest that following apoptosis, the caspase family of proteolytic enzymes have the potential to generate immunogenic fragments that contribute to the autoantigen reservoir and the production of antimitochondrial antibodies. These findings are also consistent with the generation of an autoimmune response against an intracellular antigen that evades catabolism during apoptosis.

  15. Neutralizing antibody escape during HIV-1 mother-to-child transmission involves conformational masking of distal epitopes in envelope.

    Science.gov (United States)

    Goo, Leslie; Milligan, Caitlin; Simonich, Cassandra A; Nduati, Ruth; Overbaugh, Julie

    2012-09-01

    HIV-1 variants transmitted to infants are often resistant to maternal neutralizing antibodies (NAbs), suggesting that they have escaped maternal NAb pressure. To define the molecular basis of NAb escape that contributes to selection of transmitted variants, we analyzed 5 viruses from 2 mother-to-child transmission pairs, in which the infant virus, but not the maternal virus, was resistant to neutralization by maternal plasma near transmission. We generated chimeric viruses between maternal and infant envelope clones obtained near transmission and examined neutralization by maternal plasma. The molecular determinants of NAb escape were distinct, even when comparing two maternal variants to the transmitted infant virus within one pair, in which insertions in V4 of gp120 and substitutions in HR2 of gp41 conferred neutralization resistance. In another pair, deletions and substitutions in V1 to V3 conferred resistance, but neither V1/V2 nor V3 alone was sufficient. Although the sequence determinants of escape were distinct, all of them involved modifications of potential N-linked glycosylation sites. None of the regions that mediated escape were major linear targets of maternal NAbs because corresponding peptides failed to compete for neutralization. Instead, these regions disrupted multiple distal epitopes targeted by HIV-1-specific monoclonal antibodies, suggesting that escape from maternal NAbs occurred through conformational masking of distal epitopes. This strategy likely allows HIV-1 to utilize relatively limited changes in the envelope to preserve the ability to infect a new host while simultaneously evading multiple NAb specificities present in maternal plasma.

  16. Escape from autologous neutralizing antibodies in acute/early subtype C HIV-1 infection requires multiple pathways.

    Science.gov (United States)

    Rong, Rong; Li, Bing; Lynch, Rebecca M; Haaland, Richard E; Murphy, Megan K; Mulenga, Joseph; Allen, Susan A; Pinter, Abraham; Shaw, George M; Hunter, Eric; Robinson, James E; Gnanakaran, S; Derdeyn, Cynthia A

    2009-09-01

    One aim for an HIV vaccine is to elicit neutralizing antibodies (Nab) that can limit replication of genetically diverse viruses and prevent establishment of a new infection. Thus, identifying the strengths and weaknesses of Nab during the early stages of natural infection could prove useful in achieving this goal. Here we demonstrate that viral escape readily occurred despite the development of high titer autologous Nab in two subjects with acute/early subtype C infection. To provide a detailed portrayal of the escape pathways, Nab resistant variants identified at multiple time points were used to create a series of envelope (Env) glycoprotein chimeras and mutants within the background of a corresponding newly transmitted Env. In one subject, Nab escape was driven predominantly by changes in the region of gp120 that extends from the beginning of the V3 domain to the end of the V5 domain (V3V5). However, Nab escape pathways in this subject oscillated and at times required cooperation between V1V2 and the gp41 ectodomain. In the second subject, escape was driven by changes in V1V2. This V1V2-dependent escape pathway was retained over time, and its utility was reflected in the virus's ability to escape from two distinct monoclonal antibodies (Mabs) derived from this same patient via introduction of a single potential N-linked glycosylation site in V2. Spatial representation of the sequence changes in gp120 suggested that selective pressure acted upon the same regions of Env in these two subjects, even though the Env domains that drove escape were different. Together the findings argue that a single mutational pathway is not sufficient to confer escape in early subtype C HIV-1 infection, and support a model in which multiple strategies, including potential glycan shifts, direct alteration of an epitope sequence, and cooperative Env domain conformational masking, are used to evade neutralization.

  17. Antiphospholipid Antibodies in Lupus Nephritis.

    Directory of Open Access Journals (Sweden)

    Ioannis Parodis

    Full Text Available Lupus nephritis (LN is a major manifestation of systemic lupus erythematosus (SLE. It remains unclear whether antiphospholipid antibodies (aPL alter the course of LN. We thus investigated the impact of aPL on short-term and long-term renal outcomes in patients with LN. We assessed levels of aPL cross-sectionally in SLE patients diagnosed with (n = 204 or without (n = 294 LN, and prospectively in 64 patients with active biopsy-proven LN (52 proliferative, 12 membranous, before and after induction treatment (short-term outcomes. Long-term renal outcome in the prospective LN cohort was determined by the estimated glomerular filtration rate (eGFR and the Chronic Kidney Disease (CKD stage, after a median follow-up of 11.3 years (range: 3.3-18.8. Cross-sectional analysis revealed no association between LN and IgG/IgM anticardiolipin or anti-β2-glycoprotein I antibodies, or lupus anticoagulant. Both aPL positivity and levels were similar in patients with active LN and non-renal SLE. Following induction treatment for LN, serum IgG/IgM aPL levels decreased in responders (p<0.005 for all, but not in non-responders. Both at active LN and post-treatment, patients with IgG, but not IgM, aPL had higher creatinine levels compared with patients without IgG aPL. Neither aPL positivity nor levels were associated with changes in eGFR from either baseline or post-treatment through long-term follow-up. Moreover, aPL positivity and levels both at baseline and post-treatment were similar in patients with a CKD stage ≥3 versus 1-2 at the last follow-up. In conclusion, neither aPL positivity nor levels were found to be associated with the occurrence of LN in SLE patients. However, IgG aPL positivity in LN patients was associated with a short-term impairment of the renal function while no effect on long-term renal outcome was observed. Furthermore, IgG and IgM aPL levels decreased following induction treatment only in responders, indicating that aPL levels are

  18. Antibody repertoire development in swine.

    Science.gov (United States)

    Butler, John E; Sun, Jishan; Wertz, Nancy; Sinkora, Marek

    2006-01-01

    Swine belong to the Order Artiodactyla and like mice and humans, express IgM, IgD, IgG, IgE and IgA antibodies but a larger number of IgG subclasses. Like rabbits and chickens, expressed V(H) genes belong to the ancestral V(H)3 family and only 5 comprise >80% of the pre-immune repertoire. Since they use primarily two D(H) segments and have a single J(H) like chickens, junctional diversity plays a relatively greater role in repertoire formation than in humans and mice. Proportional light chain usage surprisingly resembles that in humans and is therefore distinctly different from the predominant kappa chain usage (>90%) of lab rodents and predominant lambda chain usage in other ungulates (>90%). The pre-immune V(kappa) repertoire also appears restricted since >95% of V(kappa)J(kappa) rearrangements use only a few members of the IGKV2 family and only J(kappa)2. Two V(lambda) families (IGLV3 and IGLV8) are used in forming the pre-immune repertoire. Antibodies that do not utilize light chains as in camelids, or the lengthy CDR3 regions seen in cattle that use V(H)4 family genes, have not been reported in swine. B cell lymphogenesis first occurs in the yolk sac but early VDJ rearrangements differ from mice and humans in that nearly 100% are in-frame and N-region additions are already present. Swine possess ileal Peyers patches like sheep which may be important for antigen-independent B cell repertoire diversification. The presence of pro B-like cells in interlobular areas of thymus and mature B cells in the thymic medulla that have switched to especially IgA in early gestation, is so far unique among mammals. The offspring of swine are believed to receive no passive immunity in utero and are precosial. Thus, they are a useful model for studies on fetal-neonatal immunological development. The model has already shown that: (a) colonization of the gut is required for responsiveness to TD and TI-2 antigens, (b) responsiveness due to colonization depends on bacterial PAMPs

  19. Delineation of pulmonary airway fluid protein fractions with HRPO binding-avidity by far-Western ligand blot and mass spectrometry analyses: a model methodology for detecting mannose-binding protein expression profiles.

    Science.gov (United States)

    Coyne, Cody P; Rashmir-Raven, Ann; Jones, Toni; Mochal, Cathleen; Linford, Robert L; Brashier, Michael; Eddy, Alison

    2009-01-01

    Limited research to date has characterized the potential for HRPO to function as a primary molecular probe. Pulmonary airway fluid was developed by non-reducing far-Western (ligand) blot analyses utilizing conjugated HRPO-strepavidin or non-conjugated HRPO without the presence of primary immunoglobulin. Endogenous esterase-like biochemical activity of fractions within pulmonary airway fluid was inactivated to determine if they were capable of biochemically converting HRPO chemiluminescent substrate. Complementary analyses modified pulmonary fluid and HRPO with beta-galactosidase and alpha-mannosidase respectively, in addition to determining the influence of mannose and maltose competitive binding on HRPO far-Western (ligand) blot analyses. Identification of pulmonary fluid fractions detected by HRPO far-Western blot analyses was determined by mass spectrometry. Modification of pulmonary fluid with beta-galactosidase, and HRPO with alpha-mannosidase in concert with maltose and mannose competitive binding analyses altered the intensity and spectrum of pulmonary fluid fractions detected by HRPO far-Western blot analysis. Identity of pulmonary airway fluid fractions detected by HRPO far-Western (ligand) blot analysis were transferrin, dynein, albumin precursor, and two 156 kDa equine peptide fragments. HRPO can function as a partially-selective primary molecular probe when applied in either a conjugated or non-conjugated form. Some protein fractions can form complexes with HRPO through molecular mechanisms that involve physical interactions at the terminal alpha-mannose-rich regions of HRPO glycan side-chains. Based on its known molecular composition and structure, HRPO provides an opportunity for the development of diagnostics methodologies relevant to disease biomarkers that possess mannose-binding avidity.

  20. HIV antibodies for treatment of HIV infection

    Science.gov (United States)

    Margolis, David M.; Koup, Richard A.; Ferrari, Guido

    2016-01-01

    Summary The bar is high to improve on current combination antiretroviral therapy (ART), now highly effective, safe, and simple. However antibodies that bind the HIV envelope are able to uniquely target the virus as it seeks to enter new target cells, or as it is expressed from previously infected cells. Further, the use of antibodies against HIV as a therapeutic may offer advantages. Antibodies can have long half-lives, and are being considered as partners for long-acting antiretrovirals for use in therapy or prevention of HIV infection. Early studies in animal models and in clinical trials suggest that such antibodies can have antiviral activity but, as with small molecule antiretrovirals, the issues of viral escape and resistance will have to be addressed. Most promising, however, are the unique properties of anti-HIV antibodies: the potential ability to opsonize viral particles, to direct antibody-dependent cellular cytotoxicity (ADCC) against actively infected cells, and ultimately the ability to direct the clearance of HIV-infected cells by effector cells of the immune system. These distinctive activities suggest that HIV antibodies and their derivatives may play an important role in the next frontier of HIV therapeutics, the effort to develop treatments that could lead to an HIV cure. PMID:28133794

  1. Structure Based Antibody-Like Peptidomimetics

    Directory of Open Access Journals (Sweden)

    Mark I. Greene

    2012-02-01

    Full Text Available Biologics such as monoclonal antibodies (mAb and soluble receptors represent new classes of therapeutic agents for treatment of several diseases. High affinity and high specificity biologics can be utilized for variety of clinical purposes. Monoclonal antibodies have been used as diagnostic agents when coupled with radionuclide, immune modulatory agents or in the treatment of cancers. Among other limitations of using large molecules for therapy the actual cost of biologics has become an issue. There is an effort among chemists and biologists to reduce the size of biologics which includes monoclonal antibodies and receptors without a reduction of biological efficacy. Single chain antibody, camel antibodies, Fv fragments are examples of this type of deconstructive process. Small high-affinity peptides have been identified using phage screening. Our laboratory used a structure-based approach to develop small-size peptidomimetics from the three-dimensional structure of proteins with immunoglobulin folds as exemplified by CD4 and antibodies. Peptides derived either from the receptor or their cognate ligand mimics the functions of the parental macromolecule. These constrained peptides not only provide a platform for developing small molecule drugs, but also provide insight into the atomic features of protein-protein interactions. A general overview of the reduction of monoclonal antibodies to small exocyclic peptide and its prospects as a useful diagnostic and as a drug in the treatment of cancer are discussed.

  2. Antibodies to Trichomonas vaginalis surface glycolipid

    Science.gov (United States)

    Bastida-Corcuera, F D; Singh, B N; Gray, G C; Stamper, P D; Davuluri, M; Schlangen, K; Corbeil, R R; Corbeil, L B

    2015-01-01

    Background Human trichomoniasis is the most common non-viral sexually transmitted disease, yet immune responses are not well studied. Methods Since the Trichomonas vaginalis lipophosphoglycan (TvLPG) is an important virulence factor, a bank of eight monoclonal antibodies was generated to define the antigen in clinical isolates. The TvLPG-specific antibody response of women who were culture positive (n=33) or negative (n=33) for T vaginalis infection was determined by isotype-specific ELISA. Results The bank of monoclonal antibodies reacted with conserved surface TvLPG epitopes in 27 isolates from pregnant women at their first prenatal visit. Conserved TvLPG epitopes were shown to be surface exposed by immunofluorescence. Sera collected from the same patients at the same time were assayed for specific antibodies. Serum and vaginal secretions from 33 T vaginalis-positive women had statistically higher IgG anti-TvLPG levels than age-matched and race-matched negative controls in the same clinical study (ptrichomoniasis were almost significantly higher than controls (p=0.055). Infected women with normal pregnancies had significantly higher vaginal IgG anti-TvLPG values than infected women with adverse outcomes of pregnancy. Conclusions These antibody responses show that infected women can respond to the conserved TvLPG antigen. Since antibodies to trichomonad surface LPG protect in a bovine model of trichomoniasis, the role of these antibodies in the human disease should be investigated. PMID:23785040

  3. Glycosylation of plant produced human antibodies.

    Science.gov (United States)

    Kallolimath, Somanath; Steinkellner, Herta

    2015-12-23

    Human immunoglobulins circulate as highly heterogeneously glycosylated mixture of otherwise homogeneous protein backbones. A series of studies, mainly on IgG, have unequivocally proven that antibodies modulate their effector function through sugars present in the Fc domain. However, our limited technology in producing complex proteins such as antibodies, with defined glycan structures hamper in depths studies. This review introduces a plant based expression platform enabling engineering of antibody glycans. The procedure is based on the simultaneous delivery of appropriate constructs, carrying cDNAs of target proteins (e.g. heavy and light chain of antibodies) in combination with human glycosylation enzymes into plant leaves. Harvesting of recombinant proteins one week post construct delivery allows high speed and flexibility. Major achievements include the production of functional active slialylated pentameric IgMs in tobacco leaves. The system provides a viable approach to the generation of antibodies with defined glycoforms on demand, contributing to studies on antibody glycans and the development of novel antibody based drugs.

  4. Evading Household Indebtedness Through Participation in group ...

    African Journals Online (AJOL)

    This paper focuses on identifying and analyzing group solidarity coping strategies in the context of the HIV/AIDS epidemic and structural social inequalities in Botswana. Ethnographic methods were used to gather data for this paper in Gaborone, the capital city of Botswana and Ramotswa, a village in the Southeast District.

  5. XIX trompetipäevad / Ia Remmel

    Index Scriptorium Estoniae

    Remmel, Ia, 1965-

    2008-01-01

    EMTAs toimunud XIX rahvusvahelistest trompetipäevadest ja selle raames peetud konkursist "Trompetitalendid 2008". Muljeid jagavad külalisprofessor Bert Langeler ja korraldaja Avo Ots. Konkursi tulemused

  6. Campylobacter jejuni strategies to evade hostile environments

    NARCIS (Netherlands)

    Vaezirad, M.M.|info:eu-repo/dai/nl/311482384

    2017-01-01

    Campylobacter jejuni is the most common cause of human bacterial foodborne disease in the western world. Each year hundreds of millions of cases of Campylobacter infection occur worldwide. After a few weeks, the infection may be followed by serious auto-immune diseases like the Guillain-Barre

  7. Maipäevad Dessaus / Maimu Berg

    Index Scriptorium Estoniae

    Berg, Maimu, 1945-

    1989-01-01

    Moekunstnike loomingulisest seminarist, mida juhendas professor ja vabakutseline kunstnik Bodo Müller, Dessaus Bauhausi hoones (Tallinnast osalesid Maimu Berg ja kunstnik Kristel Leedjärv); Bauhausi ajaloost

  8. Evading the cosmological domain wall problem

    OpenAIRE

    Larsson, Sebastian E.; Sarkar, Subir; White, Peter L.

    1996-01-01

    Discrete symmetries are commonplace in field theoretical models but pose a severe problem for cosmology since they lead to the formation of domain walls during spontaneous symmetry breaking in the early universe. However if one of the vacuua is favoured over the others, either energetically, or because of initial conditions, it will eventually come to dominate the universe. Using numerical methods, we study the evolution of the domain wall network for a variety of field configurations in two ...

  9. Tallinna Merepäevade turismikonverents

    Index Scriptorium Estoniae

    2012-01-01

    13. juulil Lennusadama angaarides toimunud turismikonverentsist "Lennukad ideed Lennusadamas", kus esinesid Tallinna abilinnapea Taavi Aas, Tallinna Sadama ärisuunajuht Ahto Ader, müügijuht Aare Maurer, EHTE arenduse ja uuringute osakonna juhataja Ain Hinsberg, kes rääkis projektist "Cultural Tourism 2011", Tallinna Lennujaama juhatuse esimees Rein Loik, Lennusadama tegevjuht Ott Sarapuu

  10. Hullud päevad von Krahlis

    Index Scriptorium Estoniae

    2006-01-01

    Von Krahli Teatris mängitakse neil päevi neli korda Peeter Jalaka lavastuses Tõnu Kõrvitsa kammeroopereid "Tuliaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libreto autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  11. Distinct Therapeutic Mechanisms of Tau Antibodies

    Science.gov (United States)

    Funk, Kristen E.; Mirbaha, Hilda; Jiang, Hong; Holtzman, David M.; Diamond, Marc I.

    2015-01-01

    Tauopathies are neurodegenerative diseases characterized by accumulation of Tau amyloids, and include Alzheimer disease and certain frontotemporal dementias. Trans-neuronal propagation of amyloid mediated by extracellular Tau may underlie disease progression. Consistent with this, active and passive vaccination studies in mouse models reduce pathology, although by unknown mechanisms. We previously reported that intracerebroventricular administration of three anti-Tau monoclonal antibodies (HJ8.5, HJ9.3, and HJ9.4) reduces pathology in a model overexpressing full-length mutant (P301S) human Tau. We now study effects of these three antibodies and a negative control antibody (HJ3.4) on Tau aggregate uptake into BV2 microglial-like cells and primary neurons. Antibody-independent Tau uptake into BV2 cells was blocked by heparin, consistent with a previously described role for heparan sulfate proteoglycans. Two therapeutic antibodies (HJ8.5 and HJ9.4) promoted uptake of full-length Tau fibrils into microglia via Fc receptors. Surprisingly, HJ9.3 promoted uptake of fibrils composed of the Tau repeat domain or Alzheimer disease-derived Tau aggregates, but failed to influence full-length recombinant Tau fibrils. Size fractionation of aggregates showed that antibodies preferentially promote uptake of larger oligomers (n ≥∼20-mer) versus smaller oligomers (n ∼10-mer) or monomer. No antibody inhibited uptake of full-length recombinant fibrils into primary neurons, but HJ9.3 blocked neuronal uptake of Tau repeat domain fibrils and Alzheimer disease-derived Tau. Antibodies thus have multiple potential mechanisms, including clearance via microglia and blockade of neuronal uptake. However these effects are epitope- and aggregate size-dependent. Establishing specific mechanisms of antibody activity in vitro may help in design and optimization of agents that are more effective in vivo. PMID:26126828

  12. Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

    Directory of Open Access Journals (Sweden)

    Gomes Maria A

    2010-03-01

    inoculated with E. dispar. Conclusion Morphological and immunohistochemical results suggest that antibodies and complement are able to bind and destroy some trophozoites in the liver of experimentally infected hamsters, perhaps selecting the more resistant parasites which are responsible by progression of amoebic abscesses. The findings indicate that E. histolytica possesses an enhanced ability in vivo to evade the immune responses compared to E. dispar, although it also causes experimental hepatic lesions.

  13. Molecular stabilization effects of interactions between anti-metatype antibodies and liganded antibody.

    Science.gov (United States)

    Weidner, K M; Denzin, L K; Voss, E W

    1992-05-25

    Anti-metatype antibodies have been described as antibodies which recognize ligand-induced conformational changes in the antibody variable region. Additionally, anti-metatype antibodies, produced by multiple immunizations with liganded high affinity monoclonal anti-fluorescein antibody 4-4-20, enhanced the lifetime of monoclonal antibody 4-4-20-fluorescein complex. To better understand the mechanism of the delayed dissociation rate, deuterium oxide was used to probe the liganded active site. The rate and extent of deuterium oxide-mediated fluorescence enhancement of bound ligand served to monitor the conformational dynamics of the active site in the presence and absence of anti-metatype antibodies. Results showed that anti-metatype antibodies reduced the rate and extent of deuterium oxide-mediated fluorescence enhancement of 4-4-20, a single-chain derivative of 4-4-20 (consisting of the variable domains and a polylinker), and idiotypically related monoclonal anti-fluorescein antibodies suggesting that anti-metatype stabilized the liganded active site. Size exclusion liquid chromatography was utilized to isolate the liganded antibody-anti-metatype complex. Liganded single chain antibody 4-4-20 was mixed with 10-fold molar excess anti-metatype Fab fragments, and a major complex eluted with an apparent M(r) 249,000. The apparent molecular weight of this complex inferred that one liganded single chain antibody was bound by five antimetatype Fab fragments. Spectral analysis confirmed these results and the characteristic delayed rate of ligand dissociation was also observed for the isolated complex. The results suggest that anti-metatype antibodies stabilize the liganded conformation by forming a large, stable, macromolecular complex.

  14. 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.

  15. 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.

  16. Intellectual property protection: strategies for antibody inventions.

    Science.gov (United States)

    Storz, Ulrich

    2011-01-01

    In the last decade, therapeutic antibodies have become one of the commercially most successful classes of biopharmaceutical drugs. Major drug manufacturers who have successfully managed to occupy this new market, as well as biotechnology firms, some of which have experienced a quick growth and are now on par with the former, owe part of their success to suitable intellectual property strategies. This article provides an overview of the current thinking on antibody-related patents, and discusses strategies for protecting the antibody products of the future.

  17. Uses of monoclonial antibody 8H9

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Nai-Kong V.

    2015-06-23

    This invention provides an antibody that binds the same antigen as that of monoclonal antibody 8H9, wherein the heavy chain CDR (Complementary Determining Region)1 comprises NYDIN, heavy chain CDR2 comprises WIFPGDGSTQY, heavy chain CDR3 comprises QTTATWFAY, and the light chain CDR1 comprises RASQSISDYLH, light chain CDR2 comprises YASQSIS, and light chain CDR3 comprises QNGHSFPLT. In another embodiment, there is provided a polypeptide that binds the same antigen as that of monoclonal antibody 8H9, wherein the polypeptide comprises NYDIN, WIFPGDGSTQY, QTTATWFAY, RASQSISDYLH, YASQSIS, and QNGHSFPLT.

  18. Engineering bispecific antibodies with defined chain pairing.

    Science.gov (United States)

    Krah, Simon; Sellmann, Carolin; Rhiel, Laura; Schröter, Christian; Dickgiesser, Stephan; Beck, Jan; Zielonka, Stefan; Toleikis, Lars; Hock, Björn; Kolmar, Harald; Becker, Stefan

    2017-10-25

    Bispecific IgG-like antibodies can simultaneously interact with two epitopes on the same or on different antigens. Therefore, these molecules facilitate novel modes of action, which cannot be addressed by conventional monospecific IgGs. However, the generation of such antibodies still appears to be demanding due to their specific architecture comprising four different polypeptide chains that need to assemble correctly. This review focusses on different strategies to circumvent this issue or to enforce a correct chain association with a focus on common-chain bispecific antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Anti-idiotype antibodies in cancer treatment

    OpenAIRE

    Alonso, Daniel Fernando; Vázquez, Ana María; Alonso, Daniel Fernando; Macías, Amparo

    2015-01-01

    Anti-idiotype antibodies (anti-Id Abs) are antibodies to idiotopes that are located in the variable region, including the antigen binding site, of another antibody. When the last is the case, these anti-Id Abs can act as surrogates of the original antigen. The capability of anti-Id Abs to modulate the immune response has been the basis for the development of anti-Id vaccines against different antigens, including tumor-associated antigens. Over the years, its use in cancer has been demonst...

  20. 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.