WorldWideScience

Sample records for intact antibodies iggs

  1. In-depth analysis of subclass-specific conformational preferences of IgG antibodies

    Directory of Open Access Journals (Sweden)

    Xinsheng Tian

    2015-01-01

    Full Text Available IgG subclass-specific differences in biological function and in vitro stability are often referred to variations in the conformational flexibility, while this flexibility has rarely been characterized. Here, small-angle X-ray scattering data from IgG1, IgG2 and IgG4 antibodies, which were designed with identical variable regions, were thoroughly analysed by the ensemble optimization method. The extended analysis of the optimized ensembles through shape clustering reveals distinct subclass-specific conformational preferences, which provide new insights for understanding the variations in physical/chemical stability and biological function of therapeutic antibodies. Importantly, the way that specific differences in the linker region correlate with the solution structure of intact antibodies is revealed, thereby visualizing future potential for the rational design of antibodies with designated physicochemical properties and tailored effector functions. In addition, this advanced computational approach is applicable to other flexible multi-domain systems and extends the potential for investigating flexibility in solutions of macromolecules by small-angle X-ray scattering.

  2. Immunochemical characteristics of IgG4 antibodies

    NARCIS (Netherlands)

    van der Zee, J. S.; Aalberse, R. C.

    1988-01-01

    Although a small part of the IgG4 subclass probably can bind to basophils (and mast cells), IgG4 antibodies usually do not behave as anaphylactic antibodies. Therefore, detection of IgG4 antibodies in serum is not a suitable in vitro assay for IgG-S-TS activity. Furthermore, differences between IgG4

  3. Serologic aspects of IgG4 antibodies. II. IgG4 antibodies form small, nonprecipitating immune complexes due to functional monovalency

    NARCIS (Netherlands)

    van der Zee, J. S.; van Swieten, P.; Aalberse, R. C.

    1986-01-01

    Human IgG4 antibodies directed against phospholipase A, the P1 antigen from Dermatophagoïdes pteronyssinus extracts, and cat albumin were found unable to cross-link antigen. Previously, it was demonstrated that IgG4 antibodies, in contrast to IgG1 antibodies, did not cross-link Sepharose-bound

  4. Naturally acquired antibodies target the glutamate-rich protein on intact merozoites and predict protection against febrile malaria

    DEFF Research Database (Denmark)

    Kana, Ikhlaq Hussain; Adu, Bright; Tiendrebeogo, Régis Wendpayangde

    2017-01-01

    febrile malaria. Similarly, GLURP-specific antibodies previously shown to be protective against febrile malaria in this same cohort were significantly associated with OP activity in this study. GLURP-specific antibodies recognized merozoites and also mediated OP activity. Conclusions.: These findings......Background.: Plasmodium species antigens accessible at the time of merozoite release are likely targets of biologically functional antibodies. Methods.: Immunoglobulin G (IgG) antibodies against intact merozoites were quantified in the plasma of Ghanaian children from a longitudinal cohort using...... a novel flow cytometry-based immunofluorescence assay. Functionality of these antibodies, as well as glutamate-rich protein (GLURP)-specific affinity-purified IgG from malaria hyperimmune Liberian adults, was assessed by the opsonic phagocytosis (OP) assay. Results.: Opsonic phagocytosis activity...

  5. Human placenta: relative content of antibodies of different classes and subclasses (IgG1-IgG4) containing lambda- and kappa-light chains and chimeric lambda-kappa-immunoglobulins.

    Science.gov (United States)

    Lekchnov, Evgenii A; Sedykh, Sergey E; Dmitrenok, Pavel S; Buneva, Valentina N; Nevinsky, Georgy A

    2015-06-01

    The specific organ placenta is much more than a filter: it is an organ that protects, feeds and regulates the growth of the embryo. Affinity chromatography, ELISA, SDS-PAGE and matrix-assisted laser desorption ionization mass spectrometry were used. Using 10 intact human placentas deprived of blood, a quantitative analysis of average relative content [% of total immunoglobulins (Igs)] was carried out for the first time: (92.7), IgA (2.4), IgM (2.5), kappa-antibodies (51.4), lambda-antibodies (48.6), IgG1 (47.0), IgG2 (39.5), IgG3 (8.8) and IgG4 (4.3). It was shown for the first time that placenta contains sIgA (2.5%). In the classic paradigm, Igs represent products of clonal B-cell populations, each producing antibodies recognizing a single antigen. There is a common belief that IgGs in mammalian biological fluids are monovalent molecules having stable structures and two identical antigen-binding sites. However, similarly to human milk Igs, placenta antibodies undergo extensive half-molecule exchange and the IgG pool consists of 43.5 ± 15.0% kappa-kappa-IgGs and 41.6 ± 17.0% lambda-lambda-IgGs, while 15.0 ± 4.0% of the IgGs contained both kappa- and lambda-light chains. Kappa-kappa-IgGs and lambda-lambda-IgGs contained, respectively (%): IgG1 (47.7 and 34.4), IgG2 (36.3 and 44.5), IgG3 (7.4 and 11.8) and IgG4 (7.5 and 9.1), while chimeric kappa-lambda-IgGs consisted of (%): 43.5 IgG1, 41.0 IgG2, 5.6 IgG3 and 7.9 IgG4. Our data are indicative of the possibility of half-molecule exchange between placenta IgGs of various subclasses, raised against different antigens, which explains a very well-known polyspecificity and cross-reactivity of different human IgGs. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Timothy-specific IgG antibody levels vary with the pollen seasons.

    Science.gov (United States)

    Nordvall, S L; Larsson, P H; Johansson, S G

    1986-11-01

    Serum samples were collected from eight grass pollen hypersensitive children during a 4-year period. The sera were assayed for contents of timothy-specific IgE antibodies by RAST. Timothy-specific IgG and IgA antibodies were quantified by a refined ELISA in which covalent binding of the antigen to the polystyrene solid phase had been performed. IgG antibodies were also assayed by a Sepharose-protein-A technique with radiolabelled timothy allergens as the antigen. It was possible to register clearcut seasonal variations with postseasonally boosted antibody levels not only of timothy-specific IgE but also of IgG antibody. Both IgG1 and IgG4 antibodies specific for timothy showed seasonal variations of a similar degree. It was not possible to register seasonal variations of the same magnitude of timothy-specific IgA antibodies.

  7. 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.

  8. Application of Food-specific IgG Antibody Detection in Allergy Dermatosis

    Directory of Open Access Journals (Sweden)

    Yine Hu

    2015-01-01

    Full Text Available The application of food-specific IgG antibody detection in allergy dermatoses was explored. 181 patients with allergy dermatoses were diagnosed from January to September 2014 and 20 healthy subjects were selected. Fourteen kinds of food-specific IgG antibodies were detected by ELISA method among all the subjects. The positive rates of IgG antibody of the patient group and the healthy group were respectively 65.2% and 5.0%. The positive rates of IgG antibody of egg, milk, shrimp and crab took a large proportion in three groups of patients with three kinds of allergy dermatoses of urticaria, eczema and allergic dermatitis, the proportion of which was respectively 70.2%, 77.8% and 71.7%. Among urticaria and allergic dermatitis patients with positive antibody, the positive rate of children was significantly higher than that of adults (p0.05. Allergy dermatoses are closely related to food-specific IgG antibodies, and the allergy dermatoses patients have a high incidence rate of food intolerance; detecting IgG antibody in the serum of patients is of great significance for the diagnosis and treatment of allergy dermatoses.

  9. Maternofetal transplacental transport of recombinant IgG antibodies lacking effector functions

    DEFF Research Database (Denmark)

    Mathiesen, Line; Nielsen, Leif K; Andersen, Jan Terje

    2013-01-01

    alloimmunity, which may be lethal. A novel strategy to control pathogenic antibodies would be administration of a non-destructive IgG antibody blocking antigen binding while retaining binding to FcRn. We report on two human IgG3 antibodies with a hinge deletion and a C131S point mutation (IgG3ΔHinge...

  10. A novel antibody engineering strategy for making monovalent bispecific heterodimeric IgG antibodies by electrostatic steering mechanism.

    Science.gov (United States)

    Liu, Zhi; Leng, Esther C; Gunasekaran, Kannan; Pentony, Martin; Shen, Min; Howard, Monique; Stoops, Janelle; Manchulenko, Kathy; Razinkov, Vladimir; Liu, Hua; Fanslow, William; Hu, Zhonghua; Sun, Nancy; Hasegawa, Haruki; Clark, Rutilio; Foltz, Ian N; Yan, Wei

    2015-03-20

    Producing pure and well behaved bispecific antibodies (bsAbs) on a large scale for preclinical and clinical testing is a challenging task. Here, we describe a new strategy for making monovalent bispecific heterodimeric IgG antibodies in mammalian cells. We applied an electrostatic steering mechanism to engineer antibody light chain-heavy chain (LC-HC) interface residues in such a way that each LC strongly favors its cognate HC when two different HCs and two different LCs are co-expressed in the same cell to assemble a functional bispecific antibody. We produced heterodimeric IgGs from transiently and stably transfected mammalian cells. The engineered heterodimeric IgG molecules maintain the overall IgG structure with correct LC-HC pairings, bind to two different antigens with comparable affinity when compared with their parental antibodies, and retain the functionality of parental antibodies in biological assays. In addition, the bispecific heterodimeric IgG derived from anti-HER2 and anti-EGF receptor (EGFR) antibody was shown to induce a higher level of receptor internalization than the combination of two parental antibodies. Mouse xenograft BxPC-3, Panc-1, and Calu-3 human tumor models showed that the heterodimeric IgGs strongly inhibited tumor growth. The described approach can be used to generate tools from two pre-existent antibodies and explore the potential of bispecific antibodies. The asymmetrically engineered Fc variants for antibody-dependent cellular cytotoxicity enhancement could be embedded in monovalent bispecific heterodimeric IgG to make best-in-class therapeutic antibodies. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Anti-pituitary antibodies against corticotrophs in IgG4-related hypophysitis.

    Science.gov (United States)

    Iwata, Naoko; Iwama, Shintaro; Sugimura, Yoshihisa; Yasuda, Yoshinori; Nakashima, Kohtaro; Takeuchi, Seiji; Hagiwara, Daisuke; Ito, Yoshihiro; Suga, Hidetaka; Goto, Motomitsu; Banno, Ryoichi; Caturegli, Patrizio; Koike, Teruhiko; Oshida, Yoshiharu; Arima, Hiroshi

    2017-06-01

    IgG4-related disease is a systemic inflammatory disease characterized by infiltration of IgG4-positive plasma cells into multiple organs, including the pituitary gland. Autoimmunity is thought to be involved in the pathogenesis of IgG4-related disease. The diagnosis of IgG4-related hypophysitis (IgG4-RH) is difficult because its clinical features, such as pituitary swelling and hypopituitarism, are similar to those of other pituitary diseases, including lymphocytic hypophysitis and sellar/suprasellar tumors. The presence and significance of anti-pituitary antibodies (APA) in IgG4-RH is unclear. In this case-control study, we used single indirect immunofluorescence on human pituitary substrates to assess the prevalence of serum APA in 17 patients with IgG4-RH, 8 control patients with other pituitary diseases (lymphocytic infundibulo-neurohypophysitis, 3; craniopharyngioma, 2; germinoma, 3), and 9 healthy subjects. We further analyzed the endocrine cells targeted by the antibodies using double indirect immunofluorescence. APA were found in 5 of 17 patients with IgG4-RH (29%), and in none of the pituitary controls or healthy subjects. The endocrine cells targeted by the antibodies in the 5 IgG4-RH cases were exclusively corticotrophs. Antibodies were of the IgG1 subclass, rather than IgG4, in all 5 cases, suggesting that IgG4 is not directly involved in the pathogenesis. Finally, antibodies recognized pro-opiomelanocortin in 2 of the cases. Our study suggests that autoimmunity is involved in the pathogenesis of IgG4-RH and that corticotrophs are the main antigenic target, highlighting a possible new diagnostic marker for this condition.

  12. A three-layer immunoradiometric assay for determination of IgG subclass antibodies in Human Sera (''IgG subclass RAST'')

    International Nuclear Information System (INIS)

    Djurup, R.; Soendergaard, I.; Weeke, B.; University of Copenhagen, Denmark); Magnusson, C.G.M.

    1984-01-01

    We report the development of a three-layer immunoradiometric assay (TIRA) for measurement of IgG antibodies of all four subclasses in human sera. The first layer consists of diluted human serum, the second layer is monoclonal mouse antibodies to human IgG subclasses, and the third layer is 125 I-labelled rabbit anti-mouse IgG. Monoclonal anti-IgGI, anti-IgG3 and anti-IgG4 reacted only with their complementary IgG subclass, whereas the anti-IgG2 showed slight cross-reactivity to immunoglobins of other subclasses and classes and to light chain proteins. The observed cross-reactivity was found to be without importance, when the TIRA was applied to measurement of IgG subclass antibodies. Equipotency was established by use of appropriate dilutions of the monoclonal antibodies, and the assay was calibrated by use of human reference serum. The TIRA therefore permits reliable inter-individual and intra-individual comparisons of the IgG antibody response in all four subclasses. Non-specific binding obtained with pooled normal human serum was below 0.33%. Inter-assay coefficient of variation was between 18 and 27%. The TIRA was applied to measurement of IgG subclass antibodies to timothy grass pollen in sera from grass pollen allergies undergoing immunotherapy. (author)

  13. Immunoradiometric assay for cytomegalovirus-specific IgG antibodies

    International Nuclear Information System (INIS)

    Klapper, P.E.; Cleator, G.M.; Prinja-Wolks, D.; Morris, D.J.

    1990-01-01

    An immunoradiometric assay (radio-immunosorbent test; RIST) for the detection of IgG antibodies to human herpesvirus 4 [human cytomegalovirus (CMV)] has been developed. The technique utilizes CMV antigen passively adsorbed to a polyvinyl microtitration plate and a radiolabelled murine monoclonal anti-human IgG antibody to detect binding of human antibody to the 'solid phase' reagent. The assay was optimized, and its specifity confirmed by testing paired acute and convalescent sera from patients with acute CMV or other human herpesvirus infections. To determine the assay's sensitivity 1433 blood donor sera were examined. The RIST was more sensitive than a standard complement fixation (CFT). Use of a monoclonal anti-human IgG antibody in the RIST reduced non-specific binding to the control uninfected cell antigen such that blood donor sera could be tested in the assay using only a CMV antigen without generating an unacceptable false positive rate. (author). 23 refs.; 1 tab

  14. Therapeutic IgG4 antibodies engage in Fab-arm exchange with endogenous human IgG4 in vivo

    NARCIS (Netherlands)

    Labrijn, Aran F.; Buijsse, Antonio Ortiz; van den Bremer, Ewald T. J.; Verwilligen, Annemiek Y. W.; Bleeker, Wim K.; Thorpe, Susan J.; Killestein, Joep; Polman, Chris H.; Aalberse, Rob C.; Schuurman, Janine; van de Winkel, Jan G. J.; Parren, Paul W. H. I.

    Two humanized IgG4 antibodies, natalizumab and gemtuzumab, are approved for human use, and several others, like TGN1412, are or have been in clinical development. Although IgG4 antibodies can dynamically exchange half-molecules(1), Fab-arm exchange with therapeutic antibodies has not been

  15. Therapeutic IgG4 antibodies engage in Fab-arm exchange with endogenous human IgG4 in vivo

    NARCIS (Netherlands)

    Labrijn, Aran F.; Buijsse, Antonio Ortiz; van den Bremer, Ewald T. J.; Verwilligen, Annemiek Y. W.; Bleeker, Wim K.; Thorpe, Susan J.; Killestein, Joep; Polman, Chris H.; Aalberse, Rob C.; Schuurman, Janine; van de Winkel, Jan G. J.; Parren, Paul W. H. I.

    2009-01-01

    Two humanized IgG4 antibodies, natalizumab and gemtuzumab, are approved for human use, and several others, like TGN1412, are or have been in clinical development. Although IgG4 antibodies can dynamically exchange half-molecules, Fab-arm exchange with therapeutic antibodies has not been demonstrated

  16. Does the Maternal Serum IgG Level during Pregnancy in Primary Antibody Deficiency Influence the IgG Level in the Newborn?

    Directory of Open Access Journals (Sweden)

    Vasantha Nagendran

    2015-01-01

    Full Text Available Purpose. To find out if the serum IgG level in the newborn baby was affected by low maternal serum IgG during pregnancy in two newly diagnosed primary antibody deficient patients. Method. Infant cord blood IgG level was compared with maternal IgG level in 2 mothers with newly diagnosed primary antibody deficiency, who declined replacement IgG treatment during pregnancy. Results. Both mothers delivered healthy babies with normal IgG levels at birth. Conclusions. The normal IgG levels and sound health in these 2 babies in spite of low maternal IgG throughout pregnancy raise interesting discussion points about maternofoetal immunoglobulin transport mechanisms in primary antibody deficiency.

  17. Human IgG4: a structural perspective.

    Science.gov (United States)

    Davies, Anna M; Sutton, Brian J

    2015-11-01

    IgG4, the least represented human IgG subclass in serum, is an intriguing antibody with unique biological properties, such as the ability to undergo Fab-arm exchange and limit immune complex formation. The lack of effector functions, such as antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity, is desirable for therapeutic purposes. IgG4 plays a protective role in allergy by acting as a blocking antibody, and inhibiting mast cell degranulation, but a deleterious role in malignant melanoma, by impeding IgG1-mediated anti-tumor immunity. These findings highlight the importance of understanding the interaction between IgG4 and Fcγ receptors. Despite a wealth of structural information for the IgG1 subclass, including complexes with Fcγ receptors, and structures for intact antibodies, high-resolution crystal structures were not reported for IgG4-Fc until recently. Here, we highlight some of the biological properties of human IgG4, and review the recent crystal structures of IgG4-Fc. We discuss the unexpected conformations adopted by functionally important Cγ2 domain loops, and speculate about potential implications for the interaction between IgG4 and FcγRs. © 2015 The Authors. Immunological Reviews Published by John Wiley & Sons Ltd.

  18. Hybrid IgG4/IgG4 Fc antibodies form upon 'Fab-arm' exchange as demonstrated by SDS-PAGE or size-exclusion chromatography

    NARCIS (Netherlands)

    Rispens, Theo; den Bleker, Tamara H.; Aalberse, Rob C.

    2010-01-01

    Human IgG4 antibodies are dynamic molecules that in vivo exchange half-molecules to become bispecific antibodies. Here we show that IgG4 antibodies and IgG4 Fc fragments similarly exchange resulting in hybrid antibodies (a single Fab + Fc) with a molecular weight of ca. 100 kDa. These antibodies can

  19. IgG and IgG subclasses antibody responses to rK39 in Leishmania donovani infections

    International Nuclear Information System (INIS)

    Daifalla, N.S.; El Hassan, A.M.

    1998-01-01

    Leishmania donovani infection cause a wide spectrum of human diseases ranging from self-healing subclinical infections to severe visceral leishmaniasis, post kal-azar dermal leishmaiasis, and mucosal leishmaiasis. The infection associated with high levels of anti-leishmania antibodies which offer a potential parameter for the serological diagnosis of L. donovani infection replacing the invasive parasitological methods. rK39, a cloned antigen of L. chagasis was reported to have high levels of anti-leishmania antibodies in Sudanese and American visceral leishmaniasis patients. In an assessment of rK39-ELISA in detecting L. donovani infection we found that the antigen detected visceral leishmaniasis, post kala-azar dermal leishmaniasis, and mucosal leismaniasis with the sensitives of 96.6%, 95.91% and 90.91% respectively. The test has the specificity of 96.7%. Further investigation of 25 visceral leishmaniasis patients showed elevated anti-rK39 antibody responses of IgG subclasses with IgG1 and IgG3 significantly higher than IgG4. igG3 showed the highest sensitivity (84.00%) whereas IgG1 showed the highest sensitivity (100%). The dynamics of the serological reactivity to rK39 in l.donovani infections will be discussed in relation to exposure, infection, cure and relapse.(Author)

  20. IgG isotypic antibodies to crude Plasmodium falciparum blood-stage ...

    African Journals Online (AJOL)

    Methods: Levels of IgG (IgG1-IgG4) and IgM to crude P. falciparum blood stage antigen ... dosage influenced P. falciparum-specific isotypic antibody responses to blood stage .... exposed Swedish donors. ..... with adverse pregnancy outcomes.

  1. Inhibition of complement activation by IgG4 antibodies

    NARCIS (Netherlands)

    van der Zee, J. S.; van Swieten, P.; Aalberse, R. C.

    1986-01-01

    Prolonged exposure to antigens may result in high IgG4 antibody titres as was shown in a previous paper (Aalberse et al., 1983b). In novice bee keepers, a shift in the IgG1/IgG4 ratio of the response against phospholipase-A (PLA; a major component of bee venom) occurred. This resulted in an

  2. IgG and IgE antibodies to Chironomidae in asthmatic patients.

    Science.gov (United States)

    Yamashita, N; Ito, K; Nakagawa, T; Haida, M; Okudaira, H; Nakada, S; Miyamoto, T; Shibuya, T; Kamei, K; Sasa, M

    1987-01-01

    IgG antibodies to Chironomidae and its correlations to radioallergosorbent and skin reactions were examined with the aim of clarifying the relationship between asthma and Chironomidae. The level of specific IgG antibody in asthmatic patients (0.698 +/- 0.034, n = 104) was significantly greater than that in normal subjects (0.367 +/- 0.032, n = 52) (P less than 0.01). The specific IgG level was not correlated to skin reaction, nor to IgE RAST scores. Specific IgG1 and IgG4 levels in asthmatic patients were significantly greater than in control subjects (n = 14) (P less than 0.01). Images Fig. 5 PMID:3652516

  3. Antibody isotypes, including IgG subclasses, in Ecuadorian patients with pulmonary Paragonimiasis

    Directory of Open Access Journals (Sweden)

    Angel Guevara E.

    1995-08-01

    Full Text Available An ELISA test was developed to detect Paragonimus-specific antibodies, including IgG subclasses, using P. mexicanus crude water-soluble antigens. The test was standardized to detect antibodies in sera of Ecuadorian patients with pulmonary paragonimiasis and negative controls from the endemic area. The detected mean levels of IgG (0.753, SEM: 0.074 and IgM (0.303, SEM: 0.033 were significantly elevated (P<0.05. Within the IgG subclasses, IgG4 showed the highest detected mean level (0.365, SEM: 0.116 and the other three subclasses showed considerably lower mean levels (IgG1, 0.186 SEM: 0.06; IgG2, 0.046 SEM: 0.01; IgG3, 0.123 SEM: 0.047. The number of P. mexicanus eggs found in sputum of infected individuals showed a positive correlation with the level of antibodies detected for IgM, IgG and its subclasses (P<0.001. The relevance of these findings in Ecuadorian patients suffering from pulmonary paragonimiasis is discussed.

  4. EPSTEIN-BARR VIRUS INFECTIONS – AVIDITY TEST FOR IgG ANTIBODIES

    Directory of Open Access Journals (Sweden)

    Katja Strašek

    2001-06-01

    Full Text Available Background. We wish to introduce specific IgG avidity test as a supplementary assay in serological screening for Epstein-Barr virus infection if the status of patient cannot be resolved from a single serum sample with routine testing.Methods. Avidity of IgG antibodies was determined in sera of 57 patients with different stage of Epstein-Barr virus infection. Enzyme-immuno assay was used with a short incubation of 6-molar urea included in the procedure. Urea should remove low avidity antibodies. Avidity was expressed as the avidity index. Avidity testing with commercial kit was done as well.Results. Low avidity index was found for IgG antibodies of acute phase sera and high for those of past infection, recent infection and reactivation of endogenic virus.Conclusions. Avidity test for IgG antibodies might be supplementary assay to prove acute infection but also to resolve some other clinical states related to Epstein-Barr virus.

  5. A methodological approach for production and purification of polyclonal antibody against dog IgG.

    Science.gov (United States)

    Sadeghi, Somayeh; Aghebati-Maleki, Leili; Nozari, Samira; Majidi, Jafar

    2018-01-01

    Antibodies are a class of biomolecules that has an important role in the immune system and lots of applications in biotechnological methods and in pharmaceutics. Production and purification of antibodies in laboratory animals is one of the first ways to manufacture of these prominent tools. The obtained antibodies from these process could be used in various types of bioassay techniques such as enzyme linked immunosorbent assay (ELISA), radioimmunoassay, etc. Also, antibodies employed in diagnostics applications in humans and other animals in order to detect specific antigens. In this study, we aimed to produce and purify anti-dog IgG via immunizing rabbits with dog IgG in combination with Freund's adjuvant. Polyclonal IgG were purified by ion exchange chromatography and then the purified antibody was labeled with horse radish peroxidase (HPR). Direct ELISA was used to determine the optimum titer and cross-reactivity of HRP conjugated IgG. The purity of various IgG preparations and the optimum dilution of prepared HRP conjugated IgG, respectively, was about 95.00% and 1:8000. This study showed that efficiency ion-exchange chromatography could be an appropriate method for purification of IgG antibodies. This antibody could be a useful tool for future dog immune diagnosis tests. This product characterization shown here sets the foundations for future work on dog IgGs.

  6. IgG4 subclass antibodies impair antitumor immunity in melanoma

    Science.gov (United States)

    Karagiannis, Panagiotis; Gilbert, Amy E.; Josephs, Debra H.; Ali, Niwa; Dodev, Tihomir; Saul, Louise; Correa, Isabel; Roberts, Luke; Beddowes, Emma; Koers, Alexander; Hobbs, Carl; Ferreira, Silvia; Geh, Jenny L.C.; Healy, Ciaran; Harries, Mark; Acland, Katharine M.; Blower, Philip J.; Mitchell, Tracey; Fear, David J.; Spicer, James F.; Lacy, Katie E.; Nestle, Frank O.; Karagiannis, Sophia N.

    2013-01-01

    Host-induced antibodies and their contributions to cancer inflammation are largely unexplored. IgG4 subclass antibodies are present in IL-10–driven Th2 immune responses in some inflammatory conditions. Since Th2-biased inflammation is a hallmark of tumor microenvironments, we investigated the presence and functional implications of IgG4 in malignant melanoma. Consistent with Th2 inflammation, CD22+ B cells and IgG4+-infiltrating cells accumulated in tumors, and IL-10, IL-4, and tumor-reactive IgG4 were expressed in situ. When compared with B cells from patient lymph nodes and blood, tumor-associated B cells were polarized to produce IgG4. Secreted B cells increased VEGF and IgG4, and tumor cells enhanced IL-10 secretion in cocultures. Unlike IgG1, an engineered tumor antigen-specific IgG4 was ineffective in triggering effector cell–mediated tumor killing in vitro. Antigen-specific and nonspecific IgG4 inhibited IgG1-mediated tumoricidal functions. IgG4 blockade was mediated through reduction of FcγRI activation. Additionally, IgG4 significantly impaired the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model. Furthermore, serum IgG4 was inversely correlated with patient survival. These findings suggest that IgG4 promoted by tumor-induced Th2-biased inflammation may restrict effector cell functions against tumors, providing a previously unexplored aspect of tumor-induced immune escape and a basis for biomarker development and patient-specific therapeutic approaches. PMID:23454746

  7. Kinetics and tissue distribution of the radiolabeled chimeric monoclonal antibody MOv18 IgG and F(ab')2 fragments in ovarian carcinoma patients

    NARCIS (Netherlands)

    Buist, M. R.; Kenemans, P.; den Hollander, W.; Vermorken, J. B.; Molthoff, C. J.; Burger, C. W.; Helmerhorst, T. J.; Baak, J. P.; Roos, J. C.

    1993-01-01

    Twenty-four patients suspected of having ovarian carcinoma received i.v. injection with a combination of radiolabeled intact IgG (1 mg) and F(ab')2 fragments (1 mg) of the chimeric monoclonal antibody MOv18, each form labeled with 1.85 MBq 131I or 125I. Laparotomy was performed either 2 or 6 days

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

    Science.gov (United States)

    Dina, Julia; Creveuil, Christian; Gouarin, Stephanie; Viron, Florent; Hebert, Amelie; Freymuth, Francois; Vabret, Astrid

    2016-01-01

    The objective of this study is primarily to compare the performance of the VIDAS® Measles immunoglobulin (Ig)G 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) 0.6. 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. PMID:27556477

  9. Radioimmunoassay of IgM, IgG, and IgA brucella antibodies

    International Nuclear Information System (INIS)

    Parrett, D.; Nielson, K.H.; White, R.G.; Payne, D.J.H.

    1977-01-01

    A radioimmunoassay (R.I.A.) has been devised to measure the serum antibody against Brucella abortus in each of the immunoglobulin classes IgM, IgG, and IgA. This test was applied to 46 sera from individuals with various clinical types of brucellosis, and the results were compared with the results of conventional direct and indirect agglutination and complement-fixation tests. The R.I.A. provided a highly sensitive primary-type assay which avoided the difficulties with blocking or non-agglutinating antibody, and thus has many advantages in the diagnosis of acute and chronic stages of brucella infection in man. The R.I.A. was successful in detection of antibody in many instances in which conventional serological tests were negative, and such antibody could (if IgM) be associated with acute or (if IgG or IgA) with chronic cases of brucellosis. One case in which B.abortus was isolated by blood culture but which failed to yield antibody by conventional tests, nevertheless showed substantial levels of IgM and IgG antibody by R.I.A. In other cases the R.I.A. test helped to eliminate the diagnosis of brucellosis by revealing absent or low antibody levels. (author)

  10. Evaluation of cysticercus-specific IgG (total and subclasses and IgE antibody responses in cerebrospinal fluid samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies

    Directory of Open Access Journals (Sweden)

    Lisandra Akemi Suzuki

    Full Text Available In the present study, an enzyme-linked immunosorbent assay (ELISA standardized with vesicular fluid of Taenia solium cysticerci was used to screen for IgG (total and subclasses and IgE antibodies in cerebrospinal fluid (CSF samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies and patients with other neurological disorders. The following results were obtained: IgG-ELISA: 100% sensitivity (median of the ELISA absorbances (MEA=1.17 and 100% specificity; IgG1-ELISA: 72.7% sensitivity (MEA=0.49 and 100% specificity; IgG2-ELISA: 81.8% sensitivity (MEA=0.46 and 100% specificity; IgG3-ELISA: 63.6% sensitivity (MEA=0.12 and 100% specificity; IgG4-ELISA: 90.9% sensitivity (MEA=0.85 and 100% specificity; IgE-ELISA 93.8% sensitivity (MEA=0.60 and 100% specificity. There were no significant differences between the sensitivities and specificities in the detection of IgG-ELISA and IgE-ELISA, although in CSF samples from patients with neurocysticercosis the MEA of the IgG-ELISA was significantly higher than that of the IgE-ELISA. The sensitivity and MEA values of the IgG4-ELISA were higher than the corresponding values for the other IgG subclasses. Future studies should address the contribution of IgG4 and IgE antibodies to the physiopathology of neurocysticercosis.

  11. Human kinetic distribution of I-123 F(Ab')/sub 2/ and FAb compared to the parent I-123 intact antibody

    International Nuclear Information System (INIS)

    De Nardo, S.J.; De Nardo, G.L.; O'Grady, L.F.; Peng, J.S.; Macey, D.J.; Mills, S.L.; Caridiff, R.D.; Epstein, A.L.

    1985-01-01

    Studies of radiolabeled monoclonal antibodies are being performed by many investigators using a variety of molecular forms of the antibody. This study evaluates two I-123-labeled antibodies (Lym-1 IgG2a and B6.01 IgG1) and their I-123-labeled FAb and F(Ab')/sub 2/ for relative whole body distribution and kinetics, selected organ kinetics, and site of degradation. Evidence of immunocomplex formation, circulating antigen, and HAMA, were monitored by HPLC-TSK analysis and appropriate radioassays of the plasma. Each antibody and each I-123-labeled fragment has been evaluated in 5 patients. One patient had serial comparisons of the radiolabeled parent molecule, F(Ab')/sub 2/ (100μg and 5 mg) and FAb (100μg) of Lym-1. Blood clearance, urine excretion rate, and plasma and urine HPLC fractionation of the radioactive species were determined. Whole body clearance by total body scans and organ clearance were obtained by geometric mean of anterior and posterior areas of interest. The FAb and F(Ab')/sub 2/ fragments had similar blood pool recovery 5 minutes after the 5-minute injection. These were the same as blood levels when 5mg of intact I-123-labeled antibody was given. The second phase of the blood curves for F(Ab')/sub 2/ had a T1/2 of 35-40 hours and for FAb was 15-20 hours. Urine excretion varied, but agreed with total body loss from body scan information. The patient with serial studies had a 24-hour residual dose of 82% for FAb, 62% for 10μg for F(Ab')/sub 2/ and 61% for 5mg of F(Ab')/sub 2/. Renal uptake for all patients was higher and more persistent with both fragments than intact antibody, but hepatic uptake was less

  12. Enzymatic Inactivation of Endogenous IgG by IdeS Enhances Therapeutic Antibody Efficacy.

    Science.gov (United States)

    Järnum, Sofia; Runström, Anna; Bockermann, Robert; Winstedt, Lena; Crispin, Max; Kjellman, Christian

    2017-09-01

    Endogenous plasma IgG sets an immunologic threshold that dictates the activity of tumor-directed therapeutic antibodies. Saturation of cellular antibody receptors by endogenous antibody limits antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Here, we show how enzymatic cleavage of IgG using the bacterial enzyme IdeS can be utilized to empty both high and low affinity Fcγ-receptors and clear the entire endogenous antibody pool. Using in vitro models, tumor animal models as well as ex vivo analysis of sera collected during a previous clinical trial with IdeS, we show how clearing of competing plasma antibody levels with IdeS unblocks cellular antibody receptors. We show that therapeutic antibodies against breast cancer (trastuzumab), colon cancer (cetuximab), and lymphomas (rituximab and alemtuzumab) can be potentiated when endogenous IgG is removed. Overall, IdeS is shown to be a potent tool to reboot the human antibody repertoire and to generate a window to preferentially load therapeutic antibodies onto effector cells and thereby create an armada of dedicated tumor-seeking immune cells. Mol Cancer Ther; 16(9); 1887-97. ©2017 AACR . ©2017 American Association for Cancer Research.

  13. Measurement of IgG antibodies to house dust mite and grass pollen by a solid-phase radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Delespesse, G; Debisschop, M J; Flament, J [Hopital Saint Pierre, Louvain (Belgium). Lab. de Recherches de la Clinique Medicale

    1979-09-01

    A solid-phase radioimmunoassay was used to measure specific IgG antibodies to either Dermatophagoides pteronyssinus (DPT) or grass pollens. Radiolabelled protein A from Staphylococcus aureus (SpA) was used to determine the IgG antibodies attached to the microtubes. The binding of IgG from either normal or allergic sera to DPT-coated tubes was antigen specific and mediated by the Fab fragment of the immunoglobulin. IgG antibodies from non-allergic serum competed with IgE antibodies to DPT. IgE antibodies did not significantly interfere with the assay. Indeed heating a reaginic serum resulted in a striking reduction of the (/sup 125/I) anti- IgE binding to allergen-coated tubes without modifying the (/sup 125/I)-SpA binding. Furthermore, filtration of a reaginic serum through Sephacryl S-200 separated a peak of IgE antibodies. The solid phase method was more sensitive than a double-antibody technique employing the same DPT extract as labelled antigen. Non-allergic subjects had less IgG antibodies to DPT or grass pollens than allergic patients. In untreated patients, there was a good correlation between levels of IgG and IgE antibodies to grass pollens but not to DPT. Patients hyposensitized to house dust mite had on the average three times more specific IgG antibodies than untreated cases. (author).

  14. Measurement of IgG antibodies to house dust mite and grass pollen by a solid-phase radioimmunoassay

    International Nuclear Information System (INIS)

    Delespesse, G.; Debisschop, M.J.; Flament, J.

    1979-01-01

    A solid-phase radioimmunoassay was used to measure specific IgG antibodies to either Dermatophagoides pteronyssinus (DPT) or grass pollens. Radiolabelled protein A from Staphylococcus aureus (SpA) was used to determine the IgG antibodies attached to the microtubes. The binding of IgG from either normal or allergic sera to DPT-coated tubes was antigen specific and mediated by the Fab fragment of the immunoglobulin. IgG antibodies from non-allergic serum competed with IgE antibodies to DPT. IgE antibodies did not significantly interfere with the assay. Indeed heating a reaginic serum resulted in a striking reduction of the ( 125 I) anti- IgE binding to allergen-coated tubes without modifying the ( 125 I)-SpA binding. Furthermore, filtration of a reaginic serum through Sephacryl S-200 separated a peak of IgE antibodies. The solid phase method was more sensitive than a double-antibody technique employing the same DPT extract as labelled antigen. Non-allergic subjects had less IgG antibodies to DPT or grass pollens than allergic patients. In untreated patients, there was a good correlation between levels of IgG and IgE antibodies to grass pollens but not to DPT. Patients hyposensitized to house dust mite had on the average three times more specific IgG antibodies than untreated cases. (author)

  15. Aggregation and pH-temperature phase behavior for aggregates of an IgG2 antibody.

    Science.gov (United States)

    Sahin, Erinc; Weiss, William F; Kroetsch, Andrew M; King, Kevin R; Kessler, R Kendall; Das, Tapan K; Roberts, Christopher J

    2012-05-01

    Monomer unfolding and thermally accelerated aggregation kinetics to produce soluble oligomers or insoluble macroscopic aggregates were characterized as a function of pH for an IgG2 antibody using differential scanning calorimetry (DSC) and size-exclusion chromatography (SEC). Aggregate size was quantified via laser light scattering, and aggregate solubility via turbidity and visual inspection. Interestingly, nonnative oligomers were soluble at pH 5.5 above approximately 15°C, but converted reversibly to visible/insoluble particles at lower temperatures. Lower pH values yielded only soluble aggregates, whereas higher pH resulted in insoluble aggregates, regardless of the solution temperature. Unlike the growing body of literature that supports the three-endotherm model of IgG1 unfolding in DSC, the results here also illustrate limitations of that model for other monoclonal antibodies. Comparison of DSC with monomer loss (via SEC) from samples during thermal scanning indicates that the least conformationally stable domain is not the most aggregation prone, and that a number of the domains remain intact within the constituent monomers of the resulting aggregates. This highlights continued challenges with predicting a priori which domain(s) or thermal transition(s) is(are) most relevant for product stability with respect to aggregation. Copyright © 2012 Wiley Periodicals, Inc.

  16. The Induction of IgM and IgG Antibodies against HLA or MICA after Lung Transplantation

    Directory of Open Access Journals (Sweden)

    Annelieke W. M. Paantjens

    2011-01-01

    Full Text Available The production of IgG HLA antibodies after lung transplantation (LTx is considered to be a major risk factor for the development of chronic rejection, represented by the bronchiolitis obliterans syndrome (BOS. It has recently been observed that elevated levels of IgM HLA antibodies also correlates with the development of chronic rejection in heart and kidney transplantation. This study investigates the relationship between IgM and IgG antibodies against HLA and MICA after lung transplantation. Serum was collected from 49 patients once prior to transplantation and monthly for up to 1 year after lung transplantation was analyzed by Luminex to detect IgM and IgG antibodies against HLA and MICA. The presence of either IgM or IgG HLA and/or MICA antibodies prior to or after transplantation was not related to survival, gender, primary disease, or the development of BOS. Additionally, the production of IgG alloantibodies was not preceded by an increase in levels of IgM, and IgM levels were not followed by an increase in IgG. Under current immune suppressive regimen, although the presence of IgM antibodies does not correlate with BOS after LTx, IgM high IgG low HLA class I antibody titers were observed more in patients with BOS compared to patients without BOS.

  17. Relation between IgG antibodies to foods and IgE antibodies to milk, egg, cat, dog and/or mite in a cross-sectional study

    NARCIS (Netherlands)

    Eysink, P. E.; de Jong, M. H.; Bindels, P. J.; Scharp-van der Linden, V. T.; de Groot, C. J.; Stapel, S. O.; Aalberse, R. C.

    1999-01-01

    Because IgG antibodies to foods can be detected before IgE antibodies to inhalants, increased levels of IgG antibodies to foods might be used as a predictor of IgE-mediated allergy in initially nonatopic children. To examine the cross-sectional relation between IgG to foods (i.e. mixture of wheat

  18. Detection of FMD virus type specific IgG1, IgG2 and IgA antibodies in milk and serum of buffaloes vaccinated with oil adjuvanted polyvalent FMD vaccine

    Directory of Open Access Journals (Sweden)

    R. Sharma

    2010-02-01

    Full Text Available The present investigation was carried out on 15 randomly selected milch buffaloes divided into three groups on the basis of lactation at an organized farm, to study the foot and mouth disease virus type specific antibodies in milk and serum following FMD vaccination. Milk and serum samples collected before vaccination i.e. 0 day and on 7, 14, 28, 42 and 56 days post vaccination, were analyzed for the detection of FMD virus specific IgG1, IgG2 and IgA antibody response by indirect double antibody sandwich ELISA. Significant FMD virus type specific antibody titres (IgG1, IgG2 and IgA were detected in milk and serum of buffaloes on different days post vaccination, though the levels of antibodies were lower in milk as compared to serum. FMD virus type specific IgG1 was found to be the predominant subclass as compared to IgG2 and IgA both in milk and serum of vaccinated buffaloes. Milk and serum IgG1, IgG2 and IgA antibody titres were positively correlated with values of regression coefficient (R as 0.506, 0.434 and 0.396, respectively.

  19. Human IgG subclass antibodies to the 19 kilodalton carboxy ...

    African Journals Online (AJOL)

    IgG2 or IgG4 antibodies were virtually nonexistent. The cross-reactivity between the 4 sequence variants (E-KNG, E-TSR, Q-KNG and. Q-TSR) of MSP119 was confirmed; however, a minority of sera preferentially recognised the KNG but not the TSR variants. All 33 P. falciparum isolates from different parts ofm Uganda

  20. Anti-inflammatory activity of human IgG4 antibodies by dynamic Fab arm exchange

    NARCIS (Netherlands)

    van der Neut Kolfschoten, Marijn; Schuurman, Janine; Losen, Mario; Bleeker, Wim K.; Martínez-Martínez, Pilar; Vermeulen, Ellen; den Bleker, Tamara H.; Wiegman, Luus; Vink, Tom; Aarden, Lucien A.; de Baets, Marc H.; van de Winkel, Jan G. J.; Aalberse, Rob C.; Parren, Paul W. H. I.

    2007-01-01

    Antibodies play a central role in immunity by forming an interface with the innate immune system and, typically, mediate proinflammatory activity. We describe a novel posttranslational modification that leads to anti-inflammatory activity of antibodies of immunoglobulin G, isotype 4 (IgG4). IgG4

  1. Determination of Antibodies (IgG, IgM against Toxoplasma gondii in Patients with Cancer

    Directory of Open Access Journals (Sweden)

    M Pedram

    2007-08-01

    Full Text Available Background: The aim of this study was determination of antibodies (IgG, IgM against Toxoplasma in malignant patients in order to refer the patients on time to the physician for treatment.Methods: This study was carried out on 252 malignant patients and 252 healthy normal subjects (as control obtained from Shafa Hospital and Medical Diagnostic Laboratory (Iran-Zamin, in Ahwaz city. Patient's information was recorded in a questionnaire before sampling. Serum samples of patients were examined for IgG and IgM antibodies by ELISA technique using Trinity kits. Results: The results of this study revealed the presence of Toxoplasma antibodies in 114 (45.2% cases of patients who were positive for Toxoplasma IgG antibodies, and 26 (10.3% cases were confirmed to be positive for Toxoplasma IgM antibodies and also 17 (6.7% of cases had both IgG and IgM antibodies against Toxoplasma gondii. In control group 92 (36.5% cases and 15 (6% cases revealed seropositive for IgG and IgM antibodies, respectively. There were no significant differences between sex, close contact with cat, living region, chemotherapy, and seropositivity rate of toxoplasmosis in patients. Comparing the age groups, the highest seropositive rate showed in the age of 51 years or higher, and their rates had tendency to increase with age in both groups. No seropositivity significant relationship was found between patients and control group.Conclusion: According to the prevalence of positive cases in these patients, it is necessary to examine the patients for toxoplasmosis before, during and after chemotherapy.

  2. A radiolabeled antiglobulin assay to identify human cervical mucus immunoglobulin (Ig) A and IgG antisperm antibodies

    International Nuclear Information System (INIS)

    Haas, G.G. Jr.; D'Cruz, O.J.

    1989-01-01

    Antisperm immunoglobulin (Ig) A and IgG antibodies in human cervical mucus (CM) were identified by a radiolabeled antiglobulin assay. Cervical mucus samples from fertile and infertile women were exposed to a 1:3,200 dilution of 2-mercaptoethanol (2-ME), and 5 micrograms of the solubilized CM protein were assayed for the presence of IgA and IgG antisperm and anti-Candida activity by the radiolabeled antiglobulin assay. Purified human secretory IgA and IgG exposed to 2-ME retained the molecular integrity and functional activity of the untreated antibody molecules. CM aliquots collected after high-performance liquid chromatography (HPLC) fractionation were assessed for antisperm antibody activity; antisperm antibody activity was retained in the appropriate IgA or IgG CM fractions. The incidence of CM antisperm antibodies was minimally affected when the radiolabeled antiglobulin assay was performed with a motile sperm population. Approximately 70% of the CM IgA antisperm antibodies were of the IgA1 subclass; CM IgG was primarily of the IgG4 subclass. When Candida antigen was substituted for sperm in the radiolabeled antiglobulin assay, the CM antisperm antibodies were found to be exclusively sperm-specific. These data indicate that the radiolabeled antiglobulin assay using 2-ME to extract CM antibodies is a specific method for the assay of antisperm antibodies in CM

  3. Lack of immunoglobulin M suppression by immunoglobulin G antibody in thymectomized, irradiated, and bone marrow-reconstituted mice infected with Toxoplasma gondii.

    OpenAIRE

    Aryanpour, J; Hafizi, A; Modabber, F

    1980-01-01

    Thymectomized, irradiated, bone marrow-reconstituted (T-deprived) mie infected with an avirulent strain of Toxoplasma gondii produced antibody titers comparable to those produced in intact syngeneic mice. Both immunoglobulin M (IgM) and IgG antibodies were produced in T-deprived animals; however, the IgM antibody remained constant in the presence of increasing amounts of IgG. In the intact animals, IgM became undetectable by day 50 postinfection as expected. Feedback inhibition of IgM by IgG ...

  4. High seropositivity of IgG and IgM antibodies against ...

    African Journals Online (AJOL)

    Objective: This study reports on the high seropositivity of immunoglobulin (Ig) G and M antibodies against CMV and the risk factors for CMV ... sex, highly active antiretroviral therapy (HAART) were not statistically associated with CMV seropositivity in this study. ... are infected with HIV have detectable IgG antibodies to CMV ...

  5. Fc receptors for mouse IgG1 on human monocytes: polymorphism and role in antibody-induced T cell proliferation.

    Science.gov (United States)

    Tax, W J; Hermes, F F; Willems, R W; Capel, P J; Koene, R A

    1984-09-01

    In previous studies, it was shown that there is polymorphism in the mitogenic effect of mouse IgG1 monoclonal antibodies against the T3 antigen of human T cells. This polymorphism implies that IgG1 anti-T3 antibodies are not mitogenic for T cells from 30% of healthy individuals. The present results demonstrate that this polymorphism is caused by polymorphism of an Fc receptor for mouse IgG1, present on human monocytes. The Fc receptor for murine IgG1 could be detected by a newly developed rosetting assay on monocytes from all individuals responsive to the mitogenic effect of IgG1 anti-T3 antibodies. This Fc receptor was not detectable on monocytes from those individuals exhibiting no mitogenic responses to IgG1 anti-T3 monoclonal antibodies. Cross-linking of T3 antigens appears to be essential for antibody-induced mitosis of T cells, because mononuclear cells that did not proliferate in response to WT 31 (an IgG1 antibody against T3 antigen) showed a proliferative response to Sepharose beads coated with WT 31. The Fc receptor--if functionally present--may be involved in the cross-linking of T3 antigens through anti-T3 antibodies. Further evidence for the involvement of this Fc receptor in antibody-induced T cell proliferation was provided by inhibition studies. Immune complexes containing IgG1 antibodies were able to inhibit the proliferative response to IgG1 anti-T3 antibodies. This inhibition by immune complexes appears to be mediated through the monocyte Fc receptor for mouse IgG1. These findings are important for the interpretation of previously described inhibitory effects of anti-T cell monoclonal antibodies on T cell proliferation, and show that such inhibitory effects may be monocyte-mediated (via immune complexes) rather than caused by a direct involvement of the respective T cell antigens in T cell mitosis. The Fc receptor for mouse IgG1 plays a role in antibody-induced T cell proliferation. Its polymorphism may have important implications for the

  6. Natural Mosquito-Pathogen Hybrid IgG4 Antibodies in Vector Borne Diseases: A Hypothesis

    Directory of Open Access Journals (Sweden)

    Berlin L. Londono-Renteria

    2016-09-01

    Full Text Available Chronic exposure to antigens may favor the production of IgG4 antibodies over other antibody types. Recent studies have shown that up to a 30% of normal human IgG4 is bi-specific and is able to recognize two antigens of different nature. A requirement for this specificity is the presence of both eliciting antigens in the same time and at the same place where the immune response is induced. During transmission of most vector-borne diseases, the pathogen is delivered to the vertebrate host along with the arthropod saliva during blood feeding and previous studies have shown the existence of IgG4 antibodies against mosquito salivary allergens. However, there is very little ongoing research or information available regarding IgG4 bi-specificity with regards to infectious disease, particularly during immune responses to vector-borne diseases such as malaria, filariasis or dengue virus infection. Here, we provide background information and present our hypothesis that IgG4 may not only be a useful tool to measure exposure to infected mosquito bites, but that these bi-specific antibodies may also play an important role in modulation of the immune response against malaria and other vector-borne diseases in endemic settings.

  7. Seroprevalence of IgG Antibodies against Mumps in Bulgarian Children under 18 Years of Age

    Directory of Open Access Journals (Sweden)

    Milena Karcheva

    2013-03-01

    Full Text Available Objective: The objective of this study was to determine the prevalence of IgG antibodies against mumps in a representative stratified sample of children under 18 years of age in Pleven district, Bulgaria. Study Design: Cross sectional study. Materials and Methods: A cross-sectional, sero-epidemiologic survey of 132 children aged under 18 years was conducted in Pleven district. They were distributed into two age groups: from 0 to 11 years old (n=80 and from 12 to 18 years old (n=52. An enzyme immunoassay (EIA was performed for indirect evidence of specific IgG antibodies in the serum. Results: The results showed that 41% of the investigated children were negative in terms of mumps IgG antibodies, 11% had borderline values and the remaining, approximately 48%, were positive. In the group of children aged 0 to 11 years who had received one dose of the mumps vaccine, 50% were negative for mumps IgG antibodies. In the second group of children aged 12 to 18 years who had received two vaccine doses, the percentage of participants negative for mumps IgG antibodies decreased significantly. Conclusion: Our observations emphasise the need to conduct expanded sero-epidemiological investigations of the populations most affected by mumps and to immunise susceptible individuals.

  8. Enhancement of antibody-dependent cell-mediated cytotoxicity by endowing IgG with FcαRI (CD89) binding.

    Science.gov (United States)

    Borrok, M Jack; Luheshi, Nadia M; Beyaz, Nurten; Davies, Gareth C; Legg, James W; Wu, Herren; Dall'Acqua, William F; Tsui, Ping

    2015-01-01

    Fc effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cell-mediated phagocytosis (ADCP) are crucial to the efficacy of many antibody therapeutics. In addition to IgG, antibodies of the IgA isotype can also promote cell killing through engagement of myeloid lineage cells via interactions between the IgA-Fc and FcαRI (CD89). Herein, we describe a unique, tandem IgG1/IgA2 antibody format in the context of a trastuzumab variable domain that exhibits enhanced ADCC and ADCP capabilities. The IgG1/IgA2 tandem Fc format retains IgG1 FcγR binding as well as FcRn-mediated serum persistence, yet is augmented with myeloid cell-mediated effector functions via FcαRI/IgA Fc interactions. In this work, we demonstrate anti-human epidermal growth factor receptor-2 antibodies with the unique tandem IgG1/IgA2 Fc can better recruit and engage cytotoxic polymorphonuclear (PMN) cells than either the parental IgG1 or IgA2. Pharmacokinetics of IgG1/IgA2 in BALB/c mice are similar to the parental IgG, and far surpass the poor serum persistence of IgA2. The IgG1/IgA2 format is expressed at similar levels and with similar thermal stability to IgG1, and can be purified via standard protein A chromatography. The tandem IgG1/IgA2 format could potentially augment IgG-based immunotherapeutics with enhanced PMN-mediated cytotoxicity while avoiding many of the problems associated with developing IgAs.

  9. Lack of immunoglobulin M suppression by immunoglobulin G antibody in thymectomized, irradiated, and bone marrow-reconstituted mice infected with Toxoplasma gondii.

    Science.gov (United States)

    Aryanpour, J; Hafizi, A; Modabber, F

    1980-03-01

    Thymectomized, irradiated, bone marrow-reconstituted (T-deprived) mie infected with an avirulent strain of Toxoplasma gondii produced antibody titers comparable to those produced in intact syngeneic mice. Both immunoglobulin M (IgM) and IgG antibodies were produced in T-deprived animals; however, the IgM antibody remained constant in the presence of increasing amounts of IgG. In the intact animals, IgM became undetectable by day 50 postinfection as expected. Feedback inhibition of IgM by IgG seems to be dependent upon T-cells in Toxoplasma-infected mice.

  10. In-depth analysis of subclass-specific conformational preferences of IgG antibodies

    DEFF Research Database (Denmark)

    Tian, Xinsheng; Vestergaard, Bente; Thorolfsson, Matthias

    2015-01-01

    IgG subclass-specific differences in biological function and in vitro stability are often referred to variations in the conformational flexibility, while this flexibility has rarely been characterized. Here, small-angle X-ray scattering data from IgG1, IgG2 and IgG4 antibodies, which were designe...... properties and tailored effector functions. In addition, this advanced computational approach is applicable to other flexible multi-domain systems and extends the potential for investigating flexibility in solutions of macromolecules by small-angle X-ray scattering....

  11. Radioimmunoassay for antibodies to rubella virus and its ribonucleoprotein component

    International Nuclear Information System (INIS)

    Ho-Terry, L.; Cohen, A.

    1979-01-01

    Using a radioimmune precipitation technique, the antibody response to intact rubella virus and its ribonucleoprotein component was measured. The method was very sensitive and reproducible, and did not require preliminary serum fractionation for the identification of antibodies of different immunoglobulin classes. The results showed that the IgA and IgG antibodies against the intact virus persisted in the sera of patients long after the initial infection. In contrast, IgA and IgG antibodies against the ribonucleoprotein component of rubella virus were detected only in sera of patients after recent rubella infection. This observation suggested that a test for antibodies to the ribonucleoprotein component may provide additional evidence in the diagnosis of recent rubella infection. This could be potentially a useful test particularly in the management of pregnant patients. (U.K.)

  12. Concurrent IgG4-related tubulointerstitial nephritis and IgG4 myeloperoxidase-anti-neutrophil cytoplasmic antibody positive crescentic glomerulonephritis: A case report.

    Science.gov (United States)

    Su, Tao; Yang, Li; Cui, Zhao; Wang, Su-Xia; Zhao, Ming-Hui

    2017-05-01

    IgG4-related disease (IgG4-RD) is a newly recognized systemic disease. The typical pathological finding in the kidney is abundant IgG4-positive plasma cell infiltration with characteristic storiform fibrosis in the interstitium. Antibodies of the IgG4 subclass have been linked to certain autoimmune diseases including antiproteinase 3 (PR3) anti-neutrophil cytoplasmic antibody (ANCA) of the IgG4 subclass. Here, we report a rare case of kidney injury with concurrent typical IgG4-related tubulointerstitial nephritis and IgG4 subclass of myeloperoxidase (MPO) ANCA-positive necrotizing crescentic glomerulonephritis. A 42-year-old Chinese man presented with repeated epigastric pain, sausage-shaped pancreas observed morphologically in computed tomography, effectiveness of prednisone therapy and was diagnosed with autoimmune pancreatitis. He subsequently developed acute kidney injury. The patient had an elevated serum IgG4, eosinophilia, and positive MPO-ANCA of IgG4-dominant subclass. Renal biopsy revealed necrotizing crescentic nephritis and typical IgG4-related tubulointerstitial nephritis. The patient was treated with a combination of corticosteroids and cyclophosphamide, and a course of rituximab was later added to deplete peripheral B cells. The patient responded well and his renal function improved. This is the first case report of an IgG4-RD with concurrent IgG4-related tubulointerstitial nephritis and IgG4 MPO-ANCA-associated necrotizing crescentic glomerulonephritis. It raises the difficulty in differentiation diagnosis of the two separate diseases that is worthy of further study.

  13. Production and characterization of anti-human IgG F(ab')2 antibody fragment.

    Science.gov (United States)

    Valedkarimi, Zahra; Nasiri, Hadi; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Esparvarinha, Mojghan; Majidi, Jafar

    2018-04-10

    In present study an optimized protocol for the separation of antibodies into antigen-binding fragments F(ab')2 using pepsin digestion was investigated. The production of these fragments is a consequential step in the development of medical research, treatment and diagnosis. For production of polyclonal antibody rabbit received antigen in four steps. The rabbit serum at 1/128000 dilution showed high absorbance in reaction with human IgG at the designed ELISA method. Rabbit IgG was purified by Ion-Exchange Chromatography (IEC) method. Purity was assessed by SDS-PAGE method. In non-reduced condition only one band was seen in about 150 kDa MW position and in reduced form, two bands were seen in 50 and 25 kDa MW positions. Rabbit IgG was digested by pepsin enzyme. The antibody fragments solution was applied to Gel filtration column to isolate the F(ab')2. Non-reduced SDS-PAGE for determining the purity of F(ab')2 fragment resulted in one band in 100 kDa corresponds to F(ab')2 fragment and a band in 150 kDa MW position corresponds to undigested IgG antibodies. The activities of FITC conjugated F(ab')2 fragment and commercial ones were compared using flowcytometry method. The activity results implied that the FITC conjugated- anti human F(ab')2 fragment worked as efficiently as the commercial one.

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

    NARCIS (Netherlands)

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

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

  15. Seroprevalence of dengue IgG antibodies in symptomatic and asymptomatic individuals three years after an outbreak in Zhejiang Province, China.

    Science.gov (United States)

    Luo, Shuying; Cui, Weihong; Li, Chan; Ling, Feng; Fu, Tao; Liu, Qiyong; Ren, Jiangping; Sun, Jimin

    2018-02-23

    Cross-reacting antibodies enhanced dengue infection in humans and antibody dependent enhancement (ADE) have been proposed as early mechanisms underlying DHF/DSS. However, the duration of dengue IgG antibodies in the body as well as factors associated with said duration remain unclear. Blood samples from 59 dengue symptomatic persons and 48 asymptomatic individuals were collected. Study participant demographic information (including age in 2009, gender, and place of residence) were also collected. Serum samples were tested for dengue specific IgG by Panbio dengue IgG indirect enzyme-linked immunosorbent assay (ELISA). Chi-square tests and logistic regression analysis of dengue IgG antibodies seroprevalence divided by gender, age groups, and symptomatic or asymptomatic infection were conducted using the Statistical Package for the Social Sciences. Overall, 70 (65.42%) blood samples were seropositive for dengue IgG antibodies with similar seroprevalences found when dividing by gender and different age groups. However, seroprevalence of dengue IgG antibodies in samples from dengue symptomatic persons was significantly higher than that in samples from asymptomatic individuals (96.61% vs 27.08%) according to multivariable logistic regression analysis, the odds ratio (OR) of the factor was 76.731. Dengue IgG antibodies were detectable in samples from most individuals three years after infection. Dengue symptomatic persons had a higher dengue IgG prevalence compared to asymptomatic individuals.

  16. Indigenous Greenlanders have a higher sero-prevalence of IgG antibodies to Helicobacter pylori than Danes

    DEFF Research Database (Denmark)

    Milman, Nils; Byg, Keld-Erik; Andersen, Leif P

    2003-01-01

    To assess the sero-prevalence of IgG antibodies to Helicobacter pylori (H. pylori) in Greenlanders and compare with the sero-prevalence in Caucasian Danes.......To assess the sero-prevalence of IgG antibodies to Helicobacter pylori (H. pylori) in Greenlanders and compare with the sero-prevalence in Caucasian Danes....

  17. Presence of specific IgG antibody to grain dust does not go with respiratory symptoms.

    Science.gov (United States)

    Park, H S; Suh, C H; Nahm, D H; Kim, H Y

    1999-02-01

    A high prevalence of work-related symptoms in relation to grain dust exposure has been reported in grain dust workers, but the role of the specific IgG antibody is unknown. To study the possible role of specific IgG (sIgG) and specific IgG4 (sIgG4) in the development of work-related symptoms, sIgG and sIgG4 subclass antibodies against grain dust antigens were determined by ELISA in sera from 43 workers and 27 non-exposed controls. They were compared with results of specific IgE antibodies, exposure intensity and the presence of respiratory symptoms. SIgG and sIgG4 antibodies were detectable in almost all sera of exposed workers, and the prevalence were significantly higher than those of controls (pgrain dust exposure and may unlikely play a role in the etiology of respiratory symptoms.

  18. Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection.

    Science.gov (United States)

    French, Martyn A; Abudulai, Laila N; Fernandez, Sonia

    2013-08-09

    The development of vaccines to treat and prevent human immunodeficiency virus (HIV) infection has been hampered by an incomplete understanding of "protective" immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8⁺ T-cell responses restricted by "protective" HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-a-dependant natural killer (NK) cell responses and plasmacytoid dendritic cell (pDC) responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection.

  19. Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection

    Directory of Open Access Journals (Sweden)

    Sonia Fernandez

    2013-08-01

    Full Text Available The development of vaccines to treat and prevent human immunodeficiency virus (HIV infection has been hampered by an incomplete understanding of “protective” immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8+ T-cell responses restricted by “protective” HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-a-dependant natural killer (NK cell responses and plasmacytoid dendritic cell (pDC responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection.

  20. Seroprevalence of diphtheria toxoid IgG antibodies in children, adolescents and adults in Poland.

    Science.gov (United States)

    Zasada, Aleksandra A; Rastawicki, Waldemar; Rokosz, Natalia; Jagielski, Marek

    2013-11-19

    Recommendations for diphtheria immunization are to apply an effective primary immunization in infancy and to maintain immunity throughout life. Immunity against diphtheria depends primarily on antibody to the diphtheria toxin. This study evaluated the seroprevalence of IgG diphtheria antitoxin in sera of healthy children, adolescents and adults in Poland. A total of 1387 serum samples collected between 2010 and 2012 from individuals with ages ranging from 1 month to 85 years were investigated. Antibody concentrations were measured with an enzyme-linked immunosorbent assay (Anti-Diphtheria Toxoid ELISA IgG, Euroimmun, Germany). The results showed that among 1387 individuals examined, 547 (39.4%) had anti-diphtheria toxoid IgG antibody levels below 0.1 IU/ml (36.9% ≤ 18 years and 40.5% >18 years old, respectively). The 212 (50.8%) children and 542 (55.9%) adults showed only basic protection (0.1-1.0 IU/ml) and need immediate booster. High levels of anti-diphtheria toxoid IgG antibodies (>1.0 IU/ml) were found more often in children and adolescent (12.2%) than in adults (3.6%) and this was statistically significant (P 60 years old. Characteristically, in individuals > 40 years old high levels of anti-diphtheria toxoid IgG antibodies (>1.0 IU/ml) were not seen. There were no statistically significant differences in results in relation to gender. The present study showed inadequate immunity levels to diphtheria amongst the Polish population, especially in adults > 40 years old and children ≤ 2 years old. To prevent reemergence of diphtheria an information campaign reminding people about recommendations concerning diphtheria booster vaccination in adults should be conducted. Moreover, the immunogenicity of the DTP vaccine used in Poland should be verified.

  1. The Induction of IgM and IgG Antibodies against HLA or MICA after Lung Transplantation

    OpenAIRE

    Paantjens, Annelieke W. M.; van de Graaf, Ed A.; Kwakkel-van Erp, Johanna M.; Hoefnagel, Tineke; van Ginkel, Walter G. J.; Fakhry, Farzia; van Kessel, Diana A.; van den Bosch, Jules M. M.; Otten, Henny G.

    2011-01-01

    The production of IgG HLA antibodies after lung transplantation (LTx) is considered to be a major risk factor for the development of chronic rejection, represented by the bronchiolitis obliterans syndrome (BOS). It has recently been observed that elevated levels of IgM HLA antibodies also correlates with the development of chronic rejection in heart and kidney transplantation. This study investigates the relationship between IgM and IgG antibodies against HLA and MICA after lung transplantati...

  2. Antigen recognition by IgG4 antibodies in human trichinellosis

    Directory of Open Access Journals (Sweden)

    Pinelli E.

    2001-06-01

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

  3. Antigen-binding radioimmunoassays for human IgG antibodies to bovine ν-lactoglobulin

    International Nuclear Information System (INIS)

    Turner, M.W.; Paganelli, R.; Levinsky, R.J.; Williams, A.

    1983-01-01

    A double antibody antigen-binding assay for the detection of human IgG antibodies to the bovine milk allergen ν-lactoglobulin is described. The levels of such antibodies in patients with established cows' milk protein intolerance were significantly higher than the levels observed in a healthy control group (P<0.01). The assay showed excellent correlation with a solid phase antigen binding assay (rsub(s) = 0.8, P<0.001). (Auth.)

  4. Prevalence of Cytomegalovirus IgG Antibodies among Pregnant Women Visiting Antenatal Clinic, LAUTECH Teaching Hospital in Osogbo, Osun State, Nigeria.

    Science.gov (United States)

    Akende, Oluwatosin; Akanbi, Olusola Anuoluwapo; Oluremi, Adeolu Sunday; Okonko, Iheanyi Omezuruike; Opaleye, Oluyinka Oladele

    2016-01-01

    Cytomegalovirus (CMV) is one of the predominant viral infections that lead to congenital diseases and teratogenic risks during the perinatal stage. There is paucity of seroepidemiological data on anti-CMV IgG antibody in pregnant women in Osogbo, Osun State, Nigeria. This study was aimed at determining the seroprevalence of Cytomegalovirus IgG antibody among pregnant women visiting antenatal clinic, LAUTECH Teaching Hospital, Osogbo, Nigeria. One hundred and seventy-four sera from the pregnant women were screened by Enzyme linked Immunosorbent Assay (ELISA) for cytomegalovirus (CMV) IgG antibody. Data analysis was done using SPSS software. In this study, 105 of the 174 pregnant women were seropositive for CMV IgG antibodies giving an antibody prevalence of 60%. There was no association found between CMV IgG seropositivity and the subjects' demographic characteristics, however, the 60.0% prevalence of CMV-IgG antibody observed amongst pregnant women in this study demands for vaccines and regular testing for the presence of CMV and its related risk factors in antenatal clinic.

  5. Toxoplasma gondii IgG antibodies in HIV/AIDS patients attending ...

    African Journals Online (AJOL)

    Background: Toxoplasmosis is caused by Toxoplasma gondii, a parasite that gradually evolved to be the most opportunistic parasite that complicates the course of HIV/AIDS in developing countries. Aim: This study was undertaken to investigate the presence of Toxoplasma gondii IgG antibodies in HIVinfected patients ...

  6. Immunoradiometric assay for cytomegalovirus-specific IgG antibodies; Assay development and evaluation in blood transfusion practice

    Energy Technology Data Exchange (ETDEWEB)

    Klapper, P.E.; Cleator, G.M.; Prinja-Wolks, D.; Morris, D.J. (Medical School, Manchester (United Kingdom). Department of Medical microbiology, Virology Unit); Morell, G. (Regional Blood Transfusion Centre, manchester (United Kingdom))

    1990-03-01

    An immunoradiometric assay (radio-immunosorbent test; RIST) for the detection of IgG antibodies to human herpesvirus 4 (human cytomegalovirus (CMV)) has been developed. The technique utilizes CMV antigen passively adsorbed to a polyvinyl microtitration plate and a radiolabelled murine monoclonal anti-human IgG antibody to detect binding of human antibody to the 'solid phase' reagent. The assay was optimized, and its specifity confirmed by testing paired acute and convalescent sera from patients with acute CMV or other human herpesvirus infections. To determine the assay's sensitivity 1433 blood donor sera were examined. The RIST was more sensitive than a standard complement fixation (CFT). Use of a monoclonal anti-human IgG antibody in the RIST reduced non-specific binding to the control uninfected cell antigen such that blood donor sera could be tested in the assay using only a CMV antigen without generating an unacceptable false positive rate. (author). 23 refs.; 1 tab.

  7. Determination of specific IgG antibody by crossed radioimmunoelectrophoresis

    International Nuclear Information System (INIS)

    Nordvall, S.L.; Uhlin, T.; Einarsson, R.

    1983-01-01

    A crossed radioimmunoelectrophoretic method was developed for detection of honey bee venom specific IgG antibodies in patient sera. At the serum concentration 1/200 the contrast between specific binding and backgroud was the most favourable. The detection limit was fairly low, approximately 30 kU/l(IgG RAST units). A reference system based on the reference kits in Phadebas IgG-RAST was elaborated. (author)

  8. Determination of specific IgG antibody by crossed radioimmunoelectrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Nordvall, S.L. (Dept. of Paediatrics, University Hospital, Uppsala, Sweden); Uhlin, T.; Einarsson, R. (Allergy Research, Pharmacia Diagnostics AB, Uppsala, Sweden)

    1983-01-01

    A crossed radioimmunoelectrophoretic method was developed for detection of honey bee venom specific IgG antibodies in patient sera. At the serum concentration 1/200 the contrast between specific binding and backgroud was the most favourable. The detection limit was fairly low, approximately 30 kU/l(IgG RAST units). A reference system based on the reference kits in Phadebas IgG-RAST was elaborated.

  9. Toxoplasmosis serology: an efficient hemagglutination procedure to detect IgG and IgM antibodies

    Directory of Open Access Journals (Sweden)

    M.E. Camargo

    1989-08-01

    Full Text Available In search of an efficient but simple, low cost procedure for the serodiagnosis of Toxoplasmosis, especially suited for routine laboratories facing technical and budget limitations as in less developed countries, the diagnostic capability of Hematoxo® , an hemagglutination test for toxoplasmosis, was evaluated in relation to a battery of tests including IgG- and IgM-immunofluorescence tests, hemagglutination and an IgM-capture enzymatic assay. Detecting a little as 5 I.U. of IgG antitoxoplasma antibodies, Hematoxo® showed a straight agreement as to reactivity and non-reactivity for the 443 non-reactive and the 387 reactive serum samples, included in this study. In 23 cases presenting a serological pattern of acute toxoplasmosis and showing IgM antibodies, Hematoxo® could detect IgM antibodies in 18, indicated by negativation or a significant decrease in titers as a result of treating samples with 2-mercapto-ethanol. However, a neat increase in sensitivity for IgM specific antibodies could be achieved by previously removing IgG from the sample, as demonstrated in a series of acute toxoplasmosis sera. A simple procedure was developed for this purpose, by reconstituting a lyophilized suspension of Protein A - rich Staphylococcus with the lowest serum dilution to be tested. Of low cost and easy to perform, Hematoxo® affords not only a practical qualitative procedure for screening reactors and non-reactors, as in prenatal services, but also quantitative assays that permit to titrate antibodies as well as to identify IgM antibodies.

  10. Predictive value of Borrelia burgdorferi IgG antibody levels in patients referred to a tertiary Lyme centre.

    Science.gov (United States)

    Zwerink, M; Zomer, T P; van Kooten, B; Blaauw, G; van Bemmel, T; van Hees, B C; Vermeeren, Y M; Landman, G W

    2018-03-01

    A two-step testing strategy is recommended in serological testing for Lyme borreliosis; positive and indeterminate enzyme-linked immunosorbent assay (ELISA) results are confirmed with immunoblots. Several ELISAs quantify the concentration of antibodies tested, however, no recommendation exists for an upper cut-off value at which an IgG ELISA is sufficient and the immunoblot can be omitted. The study objective was to determine at which IgG antibody level an immunoblot does not have any additional predictive value compared to ELISA results. Data of adult patients who visited a tertiary Lyme centre between 2008 and 2014 were analysed. Both an ELISA (Enzygnost Lyme link VlsE IgG) and immunoblot (recomLine blot Borrelia) were performed. Clinical data were extracted from the patient's digital medical record. Positive predictive values (PPVs) for either previous or active infection with Borrelia burgdorferi s.l. were calculated for different cut-off ELISA IgG antibody levels where the immunoblot was regarded as reference test. In total, 1454 patients were included. According to the two-step test strategy, 486 (33%), 69 (5%) and 899 (62%) patients had positive, indeterminate and negative Borrelia IgG serology, respectively. At IgG levels of 500 IU/ml and higher, all immunoblots were positive, resulting in a 100% PPV (95% CI: 97.0-100). At IgG levels of 200 IU/ml and higher, the PPV was 99.3% (95% CI: 97.4-99.8). In conclusion, at IgG levels of 200 IU/ml and higher, an ELISA was sufficient to detect antibodies to Borrelia burgdorferi s.l. At those IgG levels, a confirmatory immunoblot may be omitted in patients referred to a tertiary Lyme centre. Before these results can be implemented in routine diagnosis of Lyme borreliosis, confirmation of the results is necessary in other patient populations and using other quantitative ELISAs and immunoblots. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Production of double antibody for radioimmunoassay (sheep anti-rabbit IgG antiserum)

    International Nuclear Information System (INIS)

    Silva, S.R. da.

    1993-01-01

    A second antibody (sheep anti-rabbit IgG antiserum) to be used in RIAs in which the first antibody is raised in rabbits was produced. For this production, initially the IgG was isolated from rabbit serum and purified by sodium sulphate precipitation followed by ion exchange chromatography on DEAE-cellulose. Four sheep were immunized with 500 u g of purified rabbit IgG, emulsified in Freund Complete Adjuvant and administered by multisite subcutaneous injections. These injections were repeated at 20-days intervals and blood samples (40 ml) were taken from the jugular vein 10 days after the boosts for the evaluation of the antisera title. After each four boosts a great bleeding was done by the same route. Approximately 500 ml of serum were obtained in each bleeding per animal. The antisera were evaluated by the human thyrotropin RIA developed at IPEN laboratories employing reagents provided by NIDDKD, USA. These evaluations referred to the determination of the antisera title and of the ideal concentration of carrier IgG, to the study of the kinetic of precipitation and to the confirmation of the inexistent cross-reactivity with human IgG, in comparison with a reference antiserum of know precipitation characteristics supplied by the Radioassay System Laboratories. Approximately 3,6 l of antiserum (sheep anti-rabbit IgG serum) were produced from the four sheep, which presented title and precipitation characteristics very similar to those exhibited by the imported commercial product, even presenting higher titles. The results obtained in this work indicated that it was created enough experience for the production of this biological reagent for RIA, that could be done integrally in the country in greater scale, and at a very reduced cost. (author). 81 refs, 36 figs, 33 tabs

  12. Development of a polyclonal anti-dugong immunoglobulin G (IgG) antibody with evaluation of total plasma IgG in a living dugong (Dugong dugon) population.

    Science.gov (United States)

    Wong, Arthur; Lanyon, Janet M; McKee, Sara J; Linedale, Richard; Woolford, Lucy; Long, Trevor; Leggatt, Graham R

    2018-06-01

    Species-specific antibodies (Ab) for the measurement of immunoglobulins (Ig) are valuable tools for determining the humoral immune status of threatened and endangered wildlife species such as dugongs. However, no studies have reported antibody reagents against dugong immunoglobulin. The object of this study was to develop an Ab with specificity for dugong IgG and apply this tool to survey total IgG levels in plasma samples from a live wild population of dugongs in southern Queensland, Australia. Dugong IgG was isolated from plasma by protein A/G column chromatography and a polyclonal antiserum was successfully raised against the dugong IgG through immunization of mice. The anti-dugong antiserum was reactive with dugong serum but not immunoglobulin from other species such as rats and humans. When tested against a panel of dugong plasma samples, relative IgG levels from dugongs (n = 116) showed biologically relevant relationships with pregnancy status and a principal component of Body Mass Index (BMI)/globulin/fecal glucocorticosteroid (chronic stress) levels combined, which together accounted for 9.2% of the variation in total Ig levels. Together these data suggest that dugongs show variation in total IgG and that this correlates with some physiological parameters of dugong health. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. [Serum immunoglobulin IgG subclass distribution of antibody responses to pertussis toxin and filamentous hemagglutinin of Bordetella pertussis in patients with whooping cough].

    Science.gov (United States)

    Rastawicki, Waldemar; Smietańska, Karolina; Rokosz-Chudziak, Natalia; Jagielski, Marek

    2013-01-01

    The present study was aimed at determining the IgG subclass distribution against pertussis toxin (PT) and filamentous hemagglutinin (FHA) of Bordetella pertussis in patients with whooping cough. The total number of 222 serum samples obtained from patients suspected in clinical investigation for pertussis were tested separately by in-house ELISA for the presence of IgG antibodies to pertussis toxin and filamentous hemagglutinin. The percentage distribution of specific anti-PT and anti-FHA IgG subclass response was calculated only on the basis of group of sera confirmed in the present study as positive for total IgG antibodies (183 sera to PT antigen and 129 to FHA antigen). Paired serum specimens were obtained from 36 patients. Based on the results of determining the level of antibodies in the sera of 40 blood donors, the cut-off limit of serum antibodies for each subclass was set at arithmetic mean plus two standard deviations. Antibodies of IgG1 to pertussis toxin and filamentous hemagglutinin were diagnosed in 151 (82.5%) and 99 (76.7%), IgG2 in 72 (39.0%) and 50 (38.8%), IgG3 in 17 (9.3%) and 43 (33.3%), IgG4 in 55 (30.1%) and 53 (41.1%) serum samples, respectively. There were no significant differences in percentage of sera with IgG1, IgG2 and IgG3 in relation to age of the patients. However, the frequency of occurrence of IgG4 antibodies was highest in the group of the youngest children to the age of 6 years old (61.8% for PT and 68.0% for FHA), and decrease with age, reaching the minimum in the group of patients above 40 years old (13.2% and 4.2% for PT and FHA, respectively). We also found significantly higher frequency of IgG4 to PT and FHA antigens in men than in women. Statistically significant, essential changes in the pattern of IgG subclass during the course of infection were not found. In conclusion, this study showed that all four subclasses of IgG antibodies to pertussis toxin and filamentous hemagglutinin are produced during whooping cough.

  14. Specific IgG and its subclass antibodies after immunotherapy with gynandropsis gynandra

    Directory of Open Access Journals (Sweden)

    Latha G

    2005-01-01

    Full Text Available Background : About 10 to 15 % of the Indian population is known to suffer from major allergic disorders such as Asthma, Rhinitis, Atopic Dermatitis and Urticaria. Aeroallergens play a major role in the pathogenesis of respiratory allergic diseases. Among the aeroallergens, pollens are major causative agents. The predominance of pollen allergens necessitate the need to assess the specific immunotherapy (SIT in allergic patients. Objective : To evaluate the effect of immunotherapy based on the presence of IgG and its subclass antibodies towards whole pollen antigen of Gynandropsis gynandra (G.gynandra and its fractions. Material and Methods : A study was conducted in 30 bronchial asthma patients on immunotherapy, by assessing the levels of IgG and its subclasses specific to G. gynandra pollen. Results : There was a significant increase in IgG and its subclass antibodies to whole pollen antigen and its fractions i.e.> 90kD, 46-37kD and 36-32kD after the course of IT. Conclusion : The use of peptide fractions may be more appropriate instead of the whole pollen antigen to test the effect of immunotherapy.

  15. Detection of IgG antibodies against Bordetella pertussis with 125I-protein A

    International Nuclear Information System (INIS)

    Wirsing von Koenig, C.H.; Finger, H.

    1981-01-01

    A method for the detection of IgG antibodies against Bordetella pertussis is described, based on the principle of 'sandwich' radioimmunoassay. 125 I protein A is used as radioactive tracer. The influence of amounts of antigen, antibody, radioactive tracer, incubation time and temperature were tested and the optimal conditions for the assay are described. The procedure offers a simple, quick, and sensitive method for detecting antibodies against B. pertussis. Application and limitation of the test are discussed. (orig.)

  16. Serum levels of IgG and IgG4 in Hashimoto thyroiditis.

    Science.gov (United States)

    Kawashima, Sachiko-Tsukamoto; Tagami, Tetsuya; Nakao, Kanako; Nanba, Kazutaka; Tamanaha, Tamiko; Usui, Takeshi; Naruse, Mitsuhide; Minamiguchi, Sachiko; Mori, Yusuke; Tsuji, Jun; Tanaka, Issei; Shimatsu, Akira

    2014-03-01

    Although IgG4-related disease is characterized by extensive infiltration of IgG4-positive plasma cells and lymphocytes of various organs, the details of this systemic disease are still unclear. We screened serum total IgG levels in the patients with Hashimoto thyroiditis (HT) to illustrate the prevalence of IgG4-related thyroiditis in HT. Twenty-four of 94 patients with HT (25.5%) had elevated serum IgG levels and their serum IgG4 was measured. Five of the 24 cases had more than 135 mg/dL of IgG4, which is the serum criterion of IgG4-related disease. One was a female patient who was initially treated as Graves' disease and rapidly developed a firm goiter and hypothyroidism. The biopsy of her thyroid gland revealed that follicular cells were atrophic with squamous metaplasia, replaced with fibrosis, which was compatible with the fibrous variant of HT. Immunohistochemical examination revealed diffuse infiltration of IgG4-positive plasma cells, and the serum IgG4 level was 179 mg/dL. The levels of IgG and IgG4 were positively correlated with the titers of anti-thyroglobulin antibody or anti-thyroid peroxidase antibody. In conclusion, at least a small portion of patients with HT with high titers of anti-thyroid antibodies may overlap the IgG4-related thyroiditis.

  17. Pharmacokinetics and tumor targeting of 131I-labeled F(ab')2 fragments of the chimeric monoclonal antibody G250: preclinical and clinical pilot studies.

    NARCIS (Netherlands)

    Brouwers, A.H.; Mulders, P.F.A.; Oosterwijk, E.; Buijs, W.C.A.M.; Corstens, F.H.M.; Boerman, O.C.; Oyen, W.J.G.

    2004-01-01

    INTRODUCTION: Clinical and animal studies of chimeric monoclonal antibody G250 (moAb cG250) for the targeting of clear-cell renal cell carcinoma (RCC), to date, have been with the intact IgG form. To determine whether F(ab')2 fragments are more suited for radioimmunotherapy (RIT) than intact IgG,

  18. High Maternal HIV-1 Viral Load During Pregnancy Is Associated With Reduced Placental Transfer of Measles IgG Antibody

    Science.gov (United States)

    Farquhar, Carey; Nduati, Ruth; Haigwood, Nancy; Sutton, William; Mbori-Ngacha, Dorothy; Richardson, Barbra; John-Stewart, Grace

    2012-01-01

    Background Studies among HIV-1–infected women have demonstrated reduced placental transfer of IgG antibodies against measles and other pathogens. As a result, infants born to women with HIV-1 infection may not acquire adequate passive immunity in utero and this could contribute to high infant morbidity and mortality in this vulnerable population. Methods To determine factors associated with decreased placental transfer of measles IgG, 55 HIV-1–infected pregnant women who were enrolled in a Nairobi perinatal HIV-1 transmission study were followed. Maternal CD4 count, HIV-1 viral load, and HIV-1–specific gp41 antibody concentrations were measured antenatally and at delivery. Measles IgG concentrations were assayed in maternal blood and infant cord blood obtained during delivery to calculate placental antibody transfer. Results Among 40 women (73%) with positive measles titers, 30 (75%) were found to have abnormally low levels of maternofetal IgG transfer (<95%). High maternal HIV-1 viral load at 32 weeks’ gestation and at delivery was associated with reductions in placental transfer (P < 0.0001 and P = 0.0056, respectively) and infant measles IgG concentrations in cord blood (P < 0.0001 and P = 0.0073, respectively). High maternal HIV-1–specific gp41 antibody titer was also highly correlated with both decreased placental transfer (P = 0.0080) and decreased infant IgG (P < 0.0001). Conclusions This is the first study to evaluate the relationship between maternal HIV-1 viremia, maternal HIV-1 antibody concentrations, and passive immunity among HIV-1–exposed infants. These data support the hypothesis that high HIV-1 viral load during the last trimester may impair maternofetal transfer of IgG and increases risk of measles and other serious infections among HIV-1–exposed infants. PMID:16280707

  19. Prodduction of clone secretor of antibodies (IgG againt of infection bursal disease virus

    Directory of Open Access Journals (Sweden)

    Sandra Yuliet Marín

    2015-06-01

    Full Text Available ABSTRACT. Marín S.Y., dos Santos B.M., Patarroyo J.H. & Vargas M.I. [Prodduction of clone secretor of antibodies (IgG againt of infection bursal disease virus.] Produção de clones secretores de anticorpos (IgG contra o vírus da doença infecciosa bursal. Revista Brasileira de Medicina Veterinária, 37(2:238-144, 2015. Programa de Pós-Graduação em Medicina Veterinária, Universidade Federal de Viçosa, Avenida PH Rolfs, s/n, Viçosa, MG 36570- 000, Brasil. E-mail: bmsantos@ufv.br Three clones secreting of antibodies (Abs IgG against infection bursal disease virus IBDV was development. The IBDV was strain S706 (the intermediate vaccine was replicated in VERO cell and purified by sucrose gradient, for ELISA and mice inoculation. For the immunization of the mice BALB/c using as a saponin adjuvant, that allowed an inflammation reaction which enhanced the antibody response, detectable by ELISA. The fusion of splenic cells of the immunized mice and the mieloma SP2/0 resulted in 2 hybridoma families (2H11 and 5C7. After cloning by limiting dilution, 3 clones secretors of Abs from IgG class were obtained. The 3 obtained Abs were capable to reveal the proteins turn VPX and VP2 by “western blotting”, respectively of 47 kDa and 41 kDa. The definition of the isotypes recognized by obtained Abs must be object of characterization to allow the use of the antibodies in immunodiagnostic tests such as immunofluorescence, immunocitochemistry or capture ELISA, for epidemiologic of the disease researches or to differentiate vaccine’s virus of the field virus.

  20. Radioiodination of monoclonal antibody intact anti-CEA

    International Nuclear Information System (INIS)

    Okada, H.; Souza, I.T.T.; Silva, C.P.G.

    1990-11-01

    The purpose of this study is to examine a convenient system that can be used to iodinate monoclonal antibodies which is rapid, simple, efficient and reproducible, and which can be accomplished in radiopharmaceutical laboratories. It is important to remember that antibodies are sensitive biochemicals, subject to losses of the activity that is essential to their mode of action, namely the ability to bind specific antigen. The advent of solid phase iodination agents has greatly expanded the range of gentle iodination techniques available for iodinating sensitive biological materials. The agent most widely used is the Iodogen (1,3,4,6 tetrachloro-3a-6a diphenylglycoluril) method. Anti-CEA 4C sub(11) IgG sub(2a,k) (prepared in the Ludwig Institute-Sao Paulo-Brazil ) is used as model to evaluate the Iodogen methodology. The miniature chromatographic system, also rapid, accurate, simple, efficient was elaborated to determine the labelling efficiency incorporation of iodine into immunoglobulin, and the radiochemical purity of sup(131)I-anti-CEA. (author)

  1. Time resolved native ion-mobility mass spectrometry to monitor dynamics of IgG4 Fab arm exchange and "bispecific" monoclonal antibody formation.

    Science.gov (United States)

    Debaene, François; Wagner-Rousset, Elsa; Colas, Olivier; Ayoub, Daniel; Corvaïa, Nathalie; Van Dorsselaer, Alain; Beck, Alain; Cianférani, Sarah

    2013-10-15

    Monoclonal antibodies (mAbs) and derivatives such as antibody-drug conjugates (ADC) and bispecific antibodies (bsAb), are the fastest growing class of human therapeutics. Most of the therapeutic antibodies currently on the market and in clinical trials are chimeric, humanized, and human immunoglobulin G1 (IgG1). An increasing number of IgG2s and IgG4s that have distinct structural and functional properties are also investigated to develop products that lack or have diminished antibody effector functions compared to IgG1. Importantly, wild type IgG4 has been shown to form half molecules (one heavy chain and one light chain) that lack interheavy chain disulfide bonds and form intrachain disulfide bonds. Moreover, IgG4 undergoes a process of Fab-arm exchange (FAE) in which the heavy chains of antibodies of different specificities can dissociate and recombine in bispecific antibodies both in vitro and in vivo. Here, native mass spectrometry (MS) and time-resolved traveling wave ion mobility MS (TWIM-MS) were used for the first time for online monitoring of FAE and bsAb formation using Hz6F4-2v3 and natalizumab, two humanized IgG4s which bind to human Junctional Adhesion Molecule-A (JAM-A) and alpha4 integrin, respectively. In addition, native MS analysis of bsAb/JAM-A immune complexes revealed that bsAb can bind up to two antigen molecules, confirming that the Hz6F4 family preferentially binds dimeric JAM-A. Our results illustrate how IM-MS can rapidly assess bsAb structural heterogeneity and be easily implemented into MS workflows for bsAb production follow up and bsAb/antigen complex characterization. Altogether, these results provide new MS-based methodologies for in-depth FAE and bsAb formation monitoring. Native MS and IM-MS will play an increasing role in next generation biopharmaceutical product characterization like bsAbs, antibody mixtures, and antibody-drug conjugates (ADC) as well as for biosimilar and biobetter antibodies.

  2. Regulation of Polysaccharide- and Protein- Specific Antibody Responses to Intact Extracellular Bacteria

    Science.gov (United States)

    2016-03-11

    OVA peptide (amino acids 323-339), presented by MHC-II I-Ad, were purchased from Taconic Farms (Hudson, NY). They were thereafter bred in our...overnight at 4°C and plates were then washed 3x with PBS + 0.1% Tween 20. Alkaline phosphatase-conjugated polyclonal goat anti-mouse IgG Abs 41 | P a g e...phosphatase-conjugated polyclonal goat anti-mouse IgG antibodies (200 ng/ml) in PBS + 1.0% BSA were then added, and plates were incubated at 37°C for

  3. Human IgG1 antibodies suppress angiogenesis in a target-independent manner

    NARCIS (Netherlands)

    Bogdanovich, Sasha; Kim, Younghee; Mizutani, Takeshi; Yasuma, Reo; Tudisco, Laura; Cicatiello, Valeria; Bastos-Carvalho, Ana; Kerur, Nagaraj; Hirano, Yoshio; Baffi, Judit Z; Tarallo, Valeria; Li, Shengjian; Yasuma, Tetsuhiro; Arpitha, Parthasarathy; Fowler, Benjamin J; Wright, Charles B; Apicella, Ivana; Greco, Adelaide; Brunetti, Arturo; Ruvo, Menotti; Sandomenico, Annamaria; Nozaki, Miho; Ijima, Ryo; Kaneko, Hiroki; Ogura, Yuichiro; Terasaki, Hiroko; Ambati, Balamurali K; Leusen, Jeanette HW; Langdon, Wallace Y; Clark, Michael R; Armour, Kathryn L; Bruhns, Pierre; Verbeek, J Sjef; Gelfand, Bradley D; De Falco, Sandro; Ambati, Jayakrishna

    2016-01-01

    Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world's population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in

  4. Comprehensive Analysis of the Therapeutic IgG4 Antibody Pembrolizumab: Hinge Modification Blocks Half Molecule Exchange In Vitro and In Vivo.

    Science.gov (United States)

    Yang, Xiaoyu; Wang, Fengqiang; Zhang, Ying; Wang, Larry; Antonenko, Svetlana; Zhang, Shuli; Zhang, Yi Wei; Tabrizifard, Mohammad; Ermakov, Grigori; Wiswell, Derek; Beaumont, Maribel; Liu, Liming; Richardson, Daisy; Shameem, Mohammed; Ambrogelly, Alexandre

    2015-12-01

    IgG4 antibodies are evolving as an important class of cancer immunotherapies. However, human IgG4 can undergo Fab arm (half molecule) exchange with other IgG4 molecules in vivo. The hinge modification by a point mutation (S228P) prevents half molecule exchange of IgG4. However, the experimental confirmation is still expected by regulatory agencies. Here, we report for the first time the extensive analysis of half molecule exchange for a hinge-modified therapeutic IgG4 molecule, pembrolizumab (Keytruda) targeting programmed death 1 (PD1) receptor that was approved for advanced melanoma. Studies were performed in buffer or human serum using multiple exchange partners including natalizumab (Tysabri) and human IgG4 pool. Formation of bispecific antibodies was monitored by fluorescence resonance energy transfer, exchange with Fc fragments, mixed mode chromatography, immunoassays, and liquid chromatography-mass spectrometry. The half molecule exchange was also examined in vivo in SCID (severe combined immunodeficiency) mice. Both in vitro and in vivo results indicate that the hinge modification in pembrolizumab prevented half molecule exchange, whereas the unmodified counterpart anti-PD1 wt showed active exchange activity with other IgG4 antibodies or self-exchange activity with its own molecules. Our work, as an example expected for meeting regulatory requirements, contributes to establish without ambiguity that hinge-modified IgG4 antibodies are suitable for biotherapeutic applications. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  5. Anti-CagA IgG Antibody is Independent from Helicobacter pylori vacA and cagA Genotypes

    Directory of Open Access Journals (Sweden)

    Hashem Fakhre Yaseri

    2015-12-01

    Full Text Available Background: Helicobacter pylori strains have two classical virulence genes, the cytotoxinassociated A (cagA gene and the vacuolating cytotoxin A (vacA gene, which are located in thecag pathogenicity island (cagPAI. Serum immunoglobulin G (IgG antibodies to H. pylori,especially, the CagA antigen may be a reliable marker for selection of dyspeptic patients for upperendoscopy.Methods: Serum sample of 129 dyspeptic patients with positive H. pylori, were tested for serumIgG Anti-CagA antibody by ELISA. The presence of the cagA and vacA genotypes weredetermined using polymerase chain reaction (PCR on biopsy samples taken via endoscopy.Results: Positive serum IgG anti-CagA antibodies in patients with cagA+/vacA+ and cagA+/vacA- genotypes were 22/23 (95.6% and 18/19 (94.7%, respectively. In addition, serum IgG anti-CagAantibodies in patients with cagA-/vacA+ and cagA-/vacA- genotypes were 22/47 (46.8% and 33/40(82.5%, respectively.Conclusions: It can be concluded that the serum IgG anti-CagA antibody alone could selectpatients with dyspepsia following upper endoscopy. The assessment of vacuolating cytotoxinactivity of H. Pylori is, therefore, not required, even when vacA gene is positive. This hypothesisneeds to be studied in a large number of patients with dyspepsia.

  6. Structure of an isolated unglycosylated antibody CH2 domain

    International Nuclear Information System (INIS)

    Prabakaran, Ponraj; Vu, Bang K.; Gan, Jianhua; Feng, Yang; Dimitrov, Dimiter S.; Ji, Xinhua

    2008-01-01

    The crystal structure of an isolated unglycosylated antibody C H 2 domain has been determined at 1.7 Å resolution. The C H 2 (C H 3 for IgM and IgE) domain of an antibody plays an important role in mediating effector functions and preserving antibody stability. It is the only domain in human immunoglobulins (Igs) which is involved in weak interchain protein–protein interactions with another C H 2 domain solely through sugar moieties. The N-linked glycosylation at Asn297 is conserved in mammalian IgGs as well as in homologous regions of other antibody isotypes. To examine the structural details of the C H 2 domain in the absence of glycosylation and other antibody domains, the crystal structure of an isolated unglycosylated antibody γ1 C H 2 domain was determined at 1.7 Å resolution and compared with corresponding C H 2 structures from intact Fc, IgG and Fc receptor complexes. Furthermore, the oligomeric state of the protein in solution was studied using size-exclusion chromatography. The results suggested that the unglycosylated human antibody C H 2 domain is a monomer and that its structure is similar to that found in the intact Fc, IgG and Fc receptor complex structures. However, certain structural variations were observed in the Fc receptor-binding sites. Owing to its small size, stability and non-immunogenic Ig template, the C H 2-domain structure could be useful for the development by protein design of antibody domains exerting effector functions and/or antigen specificity and as a robust scaffold in protein-engineering applications

  7. Hormesis of specific IgG antibody to rabies virus in serum of mice irradiated with low dose γ-rays

    International Nuclear Information System (INIS)

    Liu Qingjie; Chen Deqing

    1998-01-01

    Objective: To explore the effect of low dose ionizing radiation on specific antibody in mouse serum. Methods: Kunming strain male mice, weighing 18-22 g, aged 6-8 weeks, were immunized intraperitoneally with rabies vaccine after exposure to cobalt-60 γ-rays. The specific IgG antibody against rabies virus in mouse serum was measured. Results: (1) The serum levels of specific IgG in mice irradiated with 5-30 cGy γ-rays were significantly elevated in comparison with those in control mice (P<0.01), the optimum stimulating dose being 10 cGy. (2) Exposure to 10 cGy caused significant enhancement and earlier emergence of the peak level of specific IgG in serum. (3) The hormesis of specific IgG to rabies virus induced by 10 cGy γ-rays could last one week at least. Conclusion: Low dose ionizing radiation can enhance the level of specific antibody in mouse serum, and this effect can last for one week at least

  8. Depigmented allergoids reveal new epitopes with capacity to induce IgG blocking antibodies.

    Science.gov (United States)

    López-Matas, M Angeles; Gallego, Mayte; Iraola, Víctor; Robinson, Douglas; Carnés, Jerónimo

    2013-01-01

    The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT) has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol) allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies. Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtained. Recognition of linear IgG-epitopes of Bet v 1 and Bet v 2 and the capacity of these IgG-antibodies to block binding of human-IgE was determined. Serum from rabbits immunized with native extracts recognised 11 linear epitopes from Bet v 1, while that from Dpg-Pol-immunized animals recognised 8. For Bet v 2, 8 epitopes were recognized by IgG from native immunized animals, and 9 from Dpg-Pol immunized one. Dpg-Pol and native immunized serum did not always recognise the same epitopes, but specific-IgG from both could block human-IgE binding sites for native extract. Depigmented-polymerized birch extract stimulates the synthesis of specific IgG-antibodies which recognize common but also novel epitopes compared with native extracts. IgG-antibodies induced by Dpg-Pol effectively inhibit human-IgE binding to allergens which may be part of the mechanism of action of SIT.

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  10. Strong antitumor activities of IgG3 antibodies to a human melanoma-associated ganglioside

    International Nuclear Information System (INIS)

    Hellstroem, I.; Brankovan, V.; Hellstroem, K.E.

    1985-01-01

    Three mouse monoclonal IgG3 antibodies, 2B2, IF4, and MG-21, recognize a G/sub D3/ ganglioside antigen that is expressed at the cell surface of most human melanomas. All three antibodies mediate antibody-dependent cellular cytotoxicity (ADCC) in vitro when tested with human lymphocytes or effector cells in a 2-hr or 4-hr 51 Cr-release test, and one antibody, MG-21, also gives strong complement-dependent cytotoxicity with human serum. Antibody 2B2, which gives ADDC also in the presence of mouse lymphocytes, inhibited the outgrowth of a human melanoma in nude mice, but antibody IF4, which showed no ADCC with mouse lymphocyte effectors, did not

  11. Pneumococcal polysaccharide vaccination elicits IgG anti-AB blood group antibodies in healthy individuals and patients with Type I diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Wendelin Wolfram

    2016-11-01

    Full Text Available Hypothesis: Blood group antibodies are natural antibodies that develop early in life in response to cross-reactive environmental antigens in the absence of antigen encounter. Even later in life structural similarities in saccharide composition between environmental antigens such as bacterial polysaccharides and blood group A/B antigens could lead to changes in serum levels, IgM/IgG isotype and affinity maturation of blood group anti-A/B antibodies. We adressed the question whether immunization with pneumococcal polysaccharide (PnP vaccine (PPV Pneumovax®23 could have such an effect in patients with with type I diabetes mellitus (DM I, an autoimmune disease where an aberrant immune response to microbial antigens likely plays a role.Methods: Anti-PnP IgM and IgG responses were determined by ELISA and the Diamed-ID Micro Typing System was used to screen anti-A/B antibody titer before and after Pneumovax®23 immunization in 28 healthy individuals and 16 patients with DM I. In addition, surface plasmon resonance (SPR technology using the Biacore® device and a synthetic blood group A/B trisaccharide as the antigen was applied to investigate IgM and IgG anti-A/B antibodies and to measure antibody binding dynamics. Results: All healthy individuals and DM I patients responded with anti-PnP IgM and IgG antibody production four to six weeks after Pneumovax®23 (Pn23 immunization, while no increase in blood group anti-A/B antibody titer was observed when measured by the Diamed-ID Micro Typing System. Interestingly, isotype-specific testing by SPR-technology revealed an increase in blood group anti-A/B IgG, but not IgM, following Pn23 immunization in both patients and controls. No change in binding characteristics of blood group anti-A/B antibodies could be detected following Pn23 vaccination, supporting the assumption of an increase in IgG antibody titer with no or very little affinity maturation.Conclusion: The study provides evidence for epitope sharing

  12. Depigmented Allergoids Reveal New Epitopes with Capacity to Induce IgG Blocking Antibodies

    Directory of Open Access Journals (Sweden)

    M. Angeles López-Matas

    2013-01-01

    Full Text Available Background. The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies. Methods. Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtained. Recognition of linear IgG-epitopes of Bet v 1 and Bet v 2 and the capacity of these IgG-antibodies to block binding of human-IgE was determined. Results. Serum from rabbits immunized with native extracts recognised 11 linear epitopes from Bet v 1, while that from Dpg-Pol-immunized animals recognised 8. For Bet v 2, 8 epitopes were recognized by IgG from native immunized animals, and 9 from Dpg-Pol immunized one. Dpg-Pol and native immunized serum did not always recognise the same epitopes, but specific-IgG from both could block human-IgE binding sites for native extract. Conclusions. Depigmented-polymerized birch extract stimulates the synthesis of specific IgG-antibodies which recognize common but also novel epitopes compared with native extracts. IgG-antibodies induced by Dpg-Pol effectively inhibit human-IgE binding to allergens which may be part of the mechanism of action of SIT.

  13. A meta-analysis of the prevalence of toxoplasma gondii igg antibodies in patients with mental disorders

    Directory of Open Access Journals (Sweden)

    Angela Dragomir1,

    2016-12-01

    Full Text Available OBJECTIVES AND BACKGROUND Toxoplasma gondii infection has been recently associated with schizophrenia and other psychiatric disorders. The aim of the present study was to evaluate the prevalence of T. gondii infection in psychiatric patients by using meta-analytical methods. MATERIALS AND METHODS By systematic research of PUBMED Database, we identified several articles on this issue. We included casecontrol studies focused on the seroprevalence of T. gondii (IgG antibodies in patients with psychiatric disorders and healthy controls, published over the past 10 years R3.2.2. free software for statistical computing and graphics was used to perform the meta-analysis. Data were pooled using a random effects model and Mantel-Haenszel method. RESULTS The PUBMED Database showed references to only seven scientific papers that investigated the prevalence of T. gondii IgG antibodies in psychiatric patients. Six hundred seventy three patients and seven hundred seventy four controls coped with the inclusion criteria and were used in our analysis. We found a significant increase of T. gondii IgG antibodies in patients with schizophrenia and other psychiatric disorders compared with controls (41.6% vs 24.54%, OR = 2.16, 95% CI = [1.45-3.21], P = .001. CONCLUSIONS An increased seroprevalence of T. gondii IgG antibodies has been reported in psychiatric patients. Our study suggests that T. gondii infection may be relevant in order to determine and understand the complex etiology of schizophrenia and other psychiatric disorders. Graphical abstract: Meta-analysis of the prevalence of T. gondii IgG antibodies in patients with mental disorders REFERENCES 1. Hamidinejat H, Ghorbanpoor M, Hosseini H, Alavi SM, Nabavi L, Jalali MH, Borojeni MP, Jafari H, Mohammadaligol S. Toxoplasma gondii infection in first-episode and inpatient individuals with schizophrenia. Int J Infect Dis. 2010;14:e978-81. doi: 10.1016/j.ijid.2010.05.018. 2. Alvarado-Esquivel C, Carrillo-Oropeza D

  14. Type-specific IgG and IgA antibodies in old lymphogranuloma venerum determined by solid-phase radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Meurman, O.; Terho, P.; Sonck, C.E.

    1981-01-01

    A solid-phase radioimmunoassay (RIA) using egg-grown purified Chlamydia trachomatis lymphogranuloma venereum (LGV) serotypes L1, L2, and L3 as antigen was used to measure type-specific IgG and IgA antibodies in sera of 36 patients who had contracted LGV infection about 40 years ago. The RIA test gave compatible results with the standard microimmunofluorescence test, and by RIA it was possible to identify the infecting serotype in 30 out of 36 patients studied. In 28 cases this was L2 and in two cases L1. Each patient had IgG antibodies and most of them (80%) IgA antibodies to at least one of the LGV serotypes. The antibody titers were still high 40 years after the acute infection, being higher than in male patients with a recent chlamydial urethritis. Highest antibody titers were detected in LGV patients who had a severe disease with intestinal involvement.

  15. Type-specific IgG and IgA antibodies in old lymphogranuloma venerum determined by solid-phase radioimmunoassay

    International Nuclear Information System (INIS)

    Meurman, O.; Terho, P.; Sonck, C.E.

    1981-01-01

    A solid-phase radioimmunoassay (RIA) using egg-grown purified Chlamydia trachomatis lymphogranuloma venereum (LGV) serotypes L1, L2, and L3 as antigen was used to measure type-specific IgG and IgA antibodies in sera of 36 patients who had contracted LGV infection about 40 years ago. The RIA test gave compatible results with the standard microimmunofluorescence test, and by RIA it was possible to identify the infecting serotype in 30 out of 36 patients studied. In 28 cases this was L2 and in two cases L1. Each patient had IgG antibodies and most of them (80%) IgA antibodies to at least one of the LGV serotypes. The antibody titers were still high 40 years after the acute infection, being higher than in male patients with a recent chlamydial urethritis. Highest antibody titers were detected in LGV patients who had a severe disease with intestinal involvement. (orig.)

  16. Depigmented Allergoids Reveal New Epitopes with Capacity to Induce IgG Blocking Antibodies

    OpenAIRE

    L?pez-Matas, M. Angeles; Gallego, Mayte; Iraola, V?ctor; Robinson, Douglas; Carn?s, Jer?nimo

    2013-01-01

    Background. The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT) has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol) allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies. Methods. Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtain...

  17. Seroprevalence of parvovirus B19 IgG and IgM antibodies among pregnant women in Oyo State, Nigeria.

    Science.gov (United States)

    Abiodun, Iyanda; Opaleye, Oluyinka Oladele; Ojurongbe, Olusola; Fagbami, Ademola Hezekiah

    2013-12-15

    Human parvovirus B19 causes a wide range of complications in pregnant women including abortion, severe fetal anemia, non-immune hydrops fetalis, and even intrauterine fetal death. However, there is a dearth of information on the prevalence of the virus among pregnant women in southwestern Nigeria. Blood samples were collected from 231 pregnant women and screened for antibodies to human parvovirus B19 IgM and IgG using an enzyme immunosorbent assay kits. Of the 231 women, 31 were in their first trimester, 146 were in their second trimester, and 54 were in their third trimester. Forty-five (20%) were positive for parvovirus B19 IgG antibodies, 10 (4%) were positive for parvovirus B19 IgM antibodies, and 176 (76%) had no detectable parvovirus B19 antibodies. Twenty-eight (19%) of the 146 pregnant women in their second trimester were positive for parvovirus B19 IgG antibody while three (2%) of the 146 were positive for parvovirus B19 IgM antibody. It is evident that there is a high prevalence of human parvovirus B19 among pregnant women in south-western Nigeria. This suggests that there is an active transmission of the virus in the community; it is therefore necessary to conduct more studies on the virus in pregnant women in Nigeria to ascertain its effect on the fetus.

  18. Amylolytic activity of IgM and IgG antibodies from patients with multiple sclerosis.

    Science.gov (United States)

    Saveliev, Andrew N; Ivanen, Dina R; Kulminskaya, Anna A; Ershova, Nadezhda A; Kanyshkova, Tat'yana G; Buneva, Valentina N; Mogelnitskii, Alexander S; Doronin, Boris M; Favorova, Olga O; Nevinsky, Georgy A; Neustroev, Kirill N

    2003-05-01

    IgG and IgM antibodies from the sera of patients with multiple sclerosis (MS) were found to possess amylolytic activity hydrolyzing alpha-(1-->4)-glucosyl linkages of maltooligosaccharides, glycogen, and several artificial substrates. Individual IgM fractions isolated from 54 analyzed patients with the clinically definite diagnoses of MS had approximately three orders of magnitude higher specific amylolytic activity than that for healthy donors, whereas IgG from only a few patients had high amylolytic activity. Strict criteria were used to prove that the amylolytic activity of IgMs and IgGs is their intrinsic property and is not due to any enzyme contamination. Fab fragments produced from IgM and IgG fractions of the MS patients displayed the same amylolytic activity. IgMs from various patients demonstrated different modes of action in hydrolyzing maltooligosaccharides.

  19. Preferential decrease in IgG4 anti-citrullinated protein antibodies during treatment with tumour necrosis factor blocking agents in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Bos, W. H.; Bartelds, G. M.; Vis, M.; van der Horst, A. R.; Wolbink, G. J.; van de Stadt, R. J.; van Schaardenburg, D.; Dijkmans, B. A. C.; Lems, W. F.; Nurmohamed, M. T.; Aarden, L.; Hamann, D.

    2009-01-01

    To investigate the dynamics of IgG1 and IgG4 anti-citrullinated protein antibody (ACPA) subclasses during anti-tumour necrosis factor (TNF) treatment in patients with rheumatoid arthritis (RA). IgG, IgG1 and IgG4 ACPA levels were determined by ELISA on anti-citrullinated fibrinogen (ACF) and IgG1 :

  20. Correlation between the Amount of Anti-D Antibodies and IgG Subclasses with Severity of Haemolytic Disease of Foetus and Newborn

    Directory of Open Access Journals (Sweden)

    Emilija Velkova

    2015-05-01

    CONCLUSIONS: The titers of the pregnant women serum those are lower than 32 and those higher than 1000 can well predict HDFN. The titers of anti-D antibodies between 64 and 512 have no exact predictive value. IgG1 and IgG3 subclasses of anti-D have no predictive value by themselves, and cannot foresee the outcome of HDFN. The research study results suggest that IgG1 and IgG3 should be included in a multi – parameter protocol for evaluation of the HDFN intensity. They can give a real assessment of the expected HDFN intensity in combination with the titer hight and the significance of the antibodies.

  1. Preferential decrease in IgG4 anti-citrullinated protein antibodies during treatment with tumour necrosis factor blocking agents in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Bos, W.H.; Bartelds, G.M.; Vis, M.; van der Horst, A.R.; Wolbink, G.J.; van de Stadt, R.J.; van Schaardenburg, D.; Dijkmans, B.A.C.; Lems, W.F.; Nurmohamed, M.T.; Aarden, L.; Hamann, D.

    2009-01-01

    Objective: To investigate the dynamics of IgG1 and IgG4 anti-citrullinated protein antibody ( ACPA) subclasses during anti-tumour necrosis factor (TNF) treatment in patients with rheumatoid arthritis ( RA). Methods: IgG, IgG1 and IgG4 ACPA levels were determined by ELISA on anti-citrullinated

  2. Preferential decrease in IgG4 anti-citrullinated protein antibodies during treatment with tumour necrosis factor blocking agents in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Bos, W.H.; Bartelds, G.M.; Vis, M.; Horst, A.; Wolbink, G.; van de Stadt, R.J.; van Schaardenburg, D.; Dijkmans, B.A.C.; Lems, W.F.; Nurmohamed, M.T.; Aarden, L.; Hamann, D.

    2009-01-01

    Objective: To investigate the dynamics of IgG1 and IgG4 anti-citrullinated protein antibody (ACPA) subclasses during anti-tumour necrosis factor (TNF) treatment in patients with rheumatoid arthritis (RA). Methods: IgG, IgG1 and IgG4 ACPA levels were determined by ELISA on anti-citrullinated

  3. Multicompartmental analysis of the kinetics of monoclonal antibody in cancer patients

    International Nuclear Information System (INIS)

    Koizumi, K.; De Nardo, G.L.; De Nardo, S.J.; Peng, J.S.; Macey, D.J.; Hisada, K.; Tonami, N.

    1985-01-01

    Multicompartmental models were applied for analysis of kinetics of iodide labeled monoclonal antibody in cancer patients. About 14 compartments such as intravascular antibody pool, interstitial antibody pool, antibody processors, tumor antigen site, intravascular immune complex pool, intravascular iodide pool, and urine iodide pool were assumed. This model accounts for three molecular species, the antibody, and antibody complex, and free iodide or iodinated peptides. Patients were injected with I-123-Lym-1 IgG2a (anti B cell lymphoma antibody). After injection, blood and urine samples were sequentially collected. Plasma and urine were separated by HPLC into fractions of intact antibody, immune complex, and free iodide. This information was used for input data in the theoretical model. SAAM computer program was used to solve these compartmental models. Published linear rate constants for human serum albumin and human non-immune IgG were initially used. However, data calculated from the model differed from observed curves in several respects. The kinetics of mouse monoclonal antibody, a foreign protein in a patient, were significantly different from those reported for human IgG. When a nonlinear, saturable hepatic processor was incorporated in the model, calculated data fit the observed data better. This kinetic model provides a basis for calculating radiation doses for radioiodinated antibodies

  4. IgG4 breaking the rules

    NARCIS (Netherlands)

    Aalberse, Rob C.; Schuurman, Janine

    2002-01-01

    Immunoglobulin G4 (IgG4) antibodies have been known for some time to be functionally monovalent. Recently, the structural basis for this monovalency has been elucidated: the in vivo exchange of IgG half-molecules (one H-plus one L-chain) among IgG4. This process results in bispecific antibodies that

  5. Genus and species-specific IgG and IgM antibodies pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Butt, T.; Abbassi, S.A.; Ahmad, R.N.; Mahmood, A.; Karamat, K.A; Malik, H.S.; Anwar, M.

    2004-01-01

    Objective: To evaluate three different enzyme immunoassays for serological diagnosis of pulmonary tuberculosis and to compare their diagnostic accuracy in different combinations. Subjects and Methods: Sera from patients suffering from pulmonary tuberculosis (n=94) with sputum positive for acid fast bacilli (AFB) and sera from control group of healthy individuals (n=90) with sputum negative for AFB were tested by Pathozyme-Myco G EIA, Pathozyme-TB Complex Plus EIA and Pathozyme Myco M EIA kits for the genus-specific IgG and IgM, and the species-specific IgG antibodies against antigens of Mycobacterium tuberculosis. Results: The detection of IgG against genus-specific antigens by Pathozyme-Myco G had a sensitivity of 46% and a specificity of 93%, of IgG against species-specific antigens by Pathozyme- TB Complex Plus had a sensitivity of 64% and specificity of 97% and of IgM against genus-specific antigens by Pathozyme Myco M had a sensitivity of 67% and specificity of 98%. When the results of these immunoassays were evaluated in combination, their sensitivity improved. Combination of genus-specific IgM and species-specific IgG yielded best results with a sensitivity of 87% and specificity of 93%. Conclusion: The sensitivity of serological diagnosis of tuberculosis is low, but it can be increased by utilizing a combination of several antigens. (author)

  6. Detection of IgM and IgG antibodies to Chlamydophila pneumoniae in pediatric community-acquired lower respiratory tract infections

    Directory of Open Access Journals (Sweden)

    Surinder Kumar

    2011-01-01

    Full Text Available Context: Chlamydophila pneumoniae (C. pneumoniae is an emerging infectious agent with a spectrum of clinical manifestations including lower and upper respiratory tract infections. Aims: To investigate the role of C. pneumoniae in community-acquired lower respiratory tract infections (LRTIs in children using serological tests. Settings and Design: Two hundred children, age 2 months to 12 years, hospitalized for community-acquired LRTIs were investigated for C. pneumoniae etiology. Materials and Methods: We investigated 200 children hospitalized for community-acquired LRTIs, using ELISA for detecting anti-C. pneumoniae IgM and IgG antibodies. The demographic, clinical and radiological findings for C. pneumoniae antibody positive and C. pneumoniae antibody negative cases were compared. Statistical Analysis Used: Data analysis was performed by Chi-square test and Fisher′s exact tests using Epi Info (2002. Results: Clinical and radiological findings in both the groups were comparable. Serological evidence of C. pneumoniae infection was observed in 12 (6% patients; specific IgM antibodies were detected in 11 (91.67%; specific IgG antibodies in 1 (8.33% patients, while 4-fold rise in C. pneumoniae IgG antibody titers were noted in none of the patients. Conclusions: C. pneumoniae has a role in community-acquired LRTIs, even in children aged < 5 years. Serological detection using ELISA would enable pediatricians in better management of C. pneumoniae infections.

  7. Isolation and purification of rabbit imunoglobulin (IgG) for the production of a second antibody for radioimunoassay

    International Nuclear Information System (INIS)

    Silva, S.R. da; Borghi, V.C.

    1990-03-01

    Immunoglobulin (IgG) from rabbit serum was isolated and purified by sodium sulphate precipitation followed by ion exchange chromatography on DEAE-cellulose. The efficiency of the procedure was followed by total protein determination during all purification steps. The purity of the final product was verified through immunoelectroforesis of IgG with sheep serum anti-rabbit whole serum. Were obtained 850 mg of pure IgG, enough for the immunization of several sheeps to be used in the production of a second antibody for radioimmunoassay. (author) [pt

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  9. A Novel Platform for the Potentiation of Therapeutic Antibodies Based on Antigen-Dependent Formation of IgG Hexamers at the Cell Surface

    DEFF Research Database (Denmark)

    de Jong, R. N.; Beurskens, F. J.; Verploegen, S.

    2016-01-01

    IgG antibodies can organize into ordered hexamers on cell surfaces after binding their antigen. These hexamers bind the first component of complement C1 inducing complement-dependent target cell killing. Here, we translated this natural concept into a novel technology platform (HexaBody technology......) for therapeutic antibody potentiation. We identified mutations that enhanced hexamer formation and complement activation by IgG1 antibodies against a range of targets on cells from hematological and solid tumor indications. IgG1 backbones with preferred mutations E345K or E430G conveyed a strong ability to induce...... conditional complement-dependent cytotoxicity (CDC) of cell lines and chronic lymphocytic leukemia (CLL) patient tumor cells, while retaining regular pharmacokinetics and biopharmaceutical developability. Both mutations potently enhanced CDC- and antibody-dependent cellular cytotoxicity (ADCC) of a type II CD...

  10. Comparative imaging and biodistribution studies with an anti-CEA monoclonal antibody and its F(ab)2 and Fab fragments in mice with colon carcinoma xenografts

    International Nuclear Information System (INIS)

    Andrew, S.M.; Pimm, M.V.; Baldwin, R.W.; Perkins, A.C.

    1986-01-01

    An IgG1 mouse monoclonal antibody directed against CEA has been digested with papain to yield F(ab) 2 and Fab fragments. Following radioiodination, intact antibody and fragments showed specific binding to cells of a CEA-producing tumour, although the immune reactivities of the fragments were lower than that of intact antibody. Gamma scintigraphy of nude mice bearing CEA producing human tumour xenografts and injected with 131 I-labelled fragments showed earlier and superior imaging of tumours than did 131 I-intact antibody, and this was most marked with the Fab fragment. Sequential dissection analyses showed that this was due to earlier and higher tumour-to-blood ratios with fragments than with intact antibody, but in absolute terms the degree of localization of both fragment types was significantly lower than that of intact antibody. (orig.)

  11. [Effect comparison between two ELISA kits in IgG antibody detection of Echinococcus granulosus].

    Science.gov (United States)

    Chu, Yan-Hong; Cai, Yu-Chun; Ai, Lin; Lu, Yan; Zhang, Jia; Chen, Jia-Xu

    2013-06-01

    To compare the effects of two ELISA kits on IgG antibody detection of human Echinococcus granulosus. A Total of 134 sera of patients with echinococcosis, paragonimiasis westermani, clonorchiasis sinensis, schistosomiasis japonica, and cysticercosis cellulosae, and normal persons were detected by two IgG ELISA kits produced by different companies. Furthermore, the specificity, sensitivity and cross reactivity were counted and analyzed statistically. The sensitivity and specificity were extremely high of the two kits as 100.00%. The cross-reactivity rates were 25.00% (paragonimiasis westermani), 26.09% (clonorchiasis sinensis), 10.00% (schistosomiasis japonica), and 87.5% (cysticercosis), respectively, by using the kit produced by the Combined Company in Shenzhen; the cross-reactivity rates were 5.00% (paragonimiasis westermani), 13.04% (clonorchiasis sinensis), 20.00% (schistosomiasis japonica), and 93.75% (cysticercosis) respectively, by using the kit produced by Haitai Company in Zhuhai. In addition, there was a significant difference of Paragonimus westermani detection (P 0.05) between the two kits. Both ELISA kits on IgG antibody detection of human Echinococcus granulosus have the advantages of a high sensitivity, specificity, convenience and high-speed. However, it is also in urgent need to further solve the cross-reactivity of Echinococcus granulosus with other parasites, in order to improve the accuracy of early diagnosis.

  12. [The comparison of two newborn cytomegalovirus IgG antibody screening ELISA kits].

    Science.gov (United States)

    Zhang, Shun-Xian; He, Xiao-Zhou; Wang, Shi-Wen; Wang, Xiao-Fang

    2013-10-01

    This study compared two newborn Cytomegalovirus (CMV) IgG antibody screening ELISA kits and evaluated the detection effectiveness of Abnova kit. CMV IgG antibodies were detected by both SeraQuest and Abnova kits from dried blood spot (DBS) samples of 488 newborn heel sticks. The detection abilities of these two kits were compared in different sample dilution concentrations. Relative detection effectiveness of the Abnova kit was defined by statistical method using the SeraQuest kit as a point of comparison. Compared to the SeraQuest screening test kit, the Abnova kit revealed a sensitivity of 98.9%, specificity of 78.6%, positive predictive value of 99.3%, negative predictive value of 68.8%, and the coincidence rate for these two screening test kits at 98.3%. The consistency check of both kits based on interpretation of the kappa statistic was relatively good. For the Abnova kit, the "area under the ROC curve" was 0.887, which indicates moderate accuracy. Abnova kit can be applied to newborn screening for congenital CMV infections. However, repeating the test for ambiguous results is suggested to increase the specificity and negative predictive value.

  13. Removal of a C-terminal serine residue proximal to the inter-chain disulfide bond of a human IgG1 lambda light chain mediates enhanced antibody stability and antibody dependent cell-mediated cytotoxicity

    Science.gov (United States)

    Shen, Yang; Zeng, Lin; Zhu, Aiping; Blanc, Tim; Patel, Dipa; Pennello, Anthony; Bari, Amtul; Ng, Stanley; Persaud, Kris; Kang, Yun (Kenneth); Balderes, Paul; Surguladze, David; Hindi, Sagit; Zhou, Qinwei; Ludwig, Dale L.; Snavely, Marshall

    2013-01-01

    Optimization of biophysical properties is a critical success factor for the developability of monoclonal antibodies with potential therapeutic applications. The inter-domain disulfide bond between light chain (Lc) and heavy chain (Hc) in human IgG1 lends structural support for antibody scaffold stability, optimal antigen binding, and normal Fc function. Recently, human IgG1λ has been suggested to exhibit significantly greater susceptibility to reduction of the inter Lc-Hc disulfide bond relative to the same disulfide bond in human IgG1κ. To understand the molecular basis for this observed difference in stability, the sequence and structure of human IgG1λ and human IgG1κ were compared. Based on this Lc comparison, three single mutations were made in the λ Lc proximal to the cysteine residue, which forms a disulfide bond with the Hc. We determined that deletion of S214 (dS) improved resistance of the association between Lc and Hc to thermal stress. In addition, deletion of this terminal serine from the Lc of IgG1λ provided further benefit, including an increase in stability at elevated pH, increased yield from transient transfection, and improved in vitro antibody dependent cell-mediated cytotoxicity (ADCC). These observations support the conclusion that the presence of the terminal serine of the λ Lc creates a weaker inter-chain disulfide bond between the Lc and Hc, leading to slightly reduced stability and a potential compromise in IgG1λ function. Our data from a human IgG1λ provide a basis for further investigation of the effects of deleting terminal serine from λLc on the stability and function of other human IgGantibodies. PMID:23567210

  14. Identifying anti-Toxocara IgG antibodies in horses of Mexico

    Directory of Open Access Journals (Sweden)

    R. Heredia

    Full Text Available ABSTRACT Both the presence of owned dogs and stray dogs allows the spread of Toxocara, a parasite whose eggs can be found in soil, water and food. Animals, including horses, serve as definitive and paratenic hosts. In México, where consumption of horse meat is common, Toxocara is a zoonotic parasite. The aim of this study was to identify the presence of anti-Toxocara antibodies in work horses and horses intended for human consumption by ELISA. ELISA was chosen for analysis as paratenic hosts do not shed Toxocara eggs in their feces. Blood samples were collected from a total of 188 horses, 94 of which were work horses and 94 horses from the slaughter house. Samples were analyzed by ELISA, and the general equine seroprevalence was found to be 44.6% (n = 188. Adult horses for slaughter had a 61.7% greater presence of anti-Toxocara antibodies (p = 0.006. Toxocara IgG antibodies were found in horses, confirming that horses are paratenic hosts and possible sources of infection for other animals and people.

  15. High prevalence of human anti-bovine IgG antibodies as the major cause of false positive reactions in two-site immunoassays based on monoclonal antibodies

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Koch, Claus; Jensen, Charlotte H

    2004-01-01

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

  16. High Concentrations of Measles Neutralizing Antibodies and High-Avidity Measles IgG Accurately Identify Measles Reinfection Cases

    Science.gov (United States)

    Rota, Jennifer S.; Hickman, Carole J.; Mercader, Sara; Redd, Susan; McNall, Rebecca J.; Williams, Nobia; McGrew, Marcia; Walls, M. Laura; Rota, Paul A.; Bellini, William J.

    2016-01-01

    In the United States, approximately 9% of the measles cases reported from 2012 to 2014 occurred in vaccinated individuals. Laboratory confirmation of measles in vaccinated individuals is challenging since IgM assays can give inconclusive results. Although a positive reverse transcription (RT)-PCR assay result from an appropriately timed specimen can provide confirmation, negative results may not rule out a highly suspicious case. Detection of high-avidity measles IgG in serum samples provides laboratory evidence of a past immunologic response to measles from natural infection or immunization. High concentrations of measles neutralizing antibody have been observed by plaque reduction neutralization (PRN) assays among confirmed measles cases with high-avidity IgG, referred to here as reinfection cases (RICs). In this study, we evaluated the utility of measuring levels of measles neutralizing antibody to distinguish RICs from noncases by receiver operating characteristic curve analysis. Single and paired serum samples with high-avidity measles IgG from suspected measles cases submitted to the CDC for routine surveillance were used for the analysis. The RICs were confirmed by a 4-fold rise in PRN titer or by RT-quantitative PCR (RT-qPCR) assay, while the noncases were negative by both assays. Discrimination accuracy was high with serum samples collected ≥3 days after rash onset (area under the curve, 0.953; 95% confidence interval [CI], 0.854 to 0.993). Measles neutralizing antibody concentrations of ≥40,000 mIU/ml identified RICs with 90% sensitivity (95% CI, 74 to 98%) and 100% specificity (95% CI, 82 to 100%). Therefore, when serological or RT-qPCR results are unavailable or inconclusive, suspected measles cases with high-avidity measles IgG can be confirmed as RICs by measles neutralizing antibody concentrations of ≥40,000 mIU/ml. PMID:27335386

  17. Development and characterization of highly informative ELISA for the detection of IgG and IgA antibodies to Сhlamydia trachomatis

    Directory of Open Access Journals (Sweden)

    O. Yu. Galkin

    2018-04-01

    Full Text Available The goal of this work was developing of highly informative an enzyme-linked immunosorbent assay (ELISA for the detection of IgG and IgA antibodies against to Chlamydia trachomatis, as well as comparative characterization of developed assay using standardized control materials. The study was conducted using: monoclonal antibodies (McAbs to human IgA and IgG; recombinant Ch. trachomatis proteins – Pgp3, major outer membrane protein (MOMP; two panels of characterized sera and four reference ELISA kits. The study of immunochemical activity of peroxidase conjugates of McAbs was performed in comparison with conjugates of commercial analogues: anti-IgG McAb 2A11 and anti-IgA McAb AD3. About half of the conjugates from the received McAbs panel were more active compared to the reference antibody conjugates. It was quite justified to use the conjugates of antibodies that interact with different antigenic determinants. When IgG antibodies were detected to MOMP, it was justified 1.14-1.56 times more; when IgA antibodies were detected to MOMP, it was justified 1.16-1.37 times more. ELISA for detecting IgG/IgA antibodies to MOMP and Pgp3 of Ch. trachomatis were evaluated using appropriately described serum panels OCO-42-28-313-00 and OCO-42-28-314-00. Comparative studies of the developed ELISA for the detection of IgG and IgA antibodies to the MOMP and Pgp3 of Ch. trachomatis showed their prominent advantage over the commercial analogues, which more clearly demonstrates the difference in the ratio of average values of optical density of positive and negative samples of the described panel of sera: this indicator for commercial kits was 1.36-3.59 times less.

  18. Detection of anti-HIV-1 IgG antibodies in whole saliva by GACELISA and Western blot assays.

    Science.gov (United States)

    Matee, M I; Lyamuya, E F; Simon, E; Mbena, E C; Kagoma, C; Samaranayake, L P; Scheutz, F

    1996-05-01

    The present study, based on 158 HIV seropositives and 167 HIV seronegatives, demonstrates that saliva collected with the Omni-SAL device and tested with GACELISA (an IgG antibody capture ELISA) is an effective non-invasive alternative to serum for anti-HIV IgG antibody screening. The study also shows that a conventional serum Western blot kit can be used, with slight modifications, for confirmatory testing of saliva specimens. Collecting saliva with the Omni-SAL device had a very good acceptance rate among Tanzanian subjects, and although this diagnostic method is not yet known by the general public, 65% of the study participants preferred to give saliva instead of blood for HIV testing.

  19. IgG2 antibodies against a clinical grade Plasmodium falciparum CSP vaccine antigen associate with protection against transgenic sporozoite challenge in mice.

    Directory of Open Access Journals (Sweden)

    Robert Schwenk

    Full Text Available The availability of a highly purified and well characterized circumsporozoite protein (CSP is essential to improve upon the partial success of recombinant CSP-based malaria vaccine candidates. Soluble, near full-length, Plasmodium falciparum CSP vaccine antigen (CS/D was produced in E. coli under bio-production conditions that comply with current Good Manufacturing Practices (cGMP. A mouse immunogenicity study was conducted using a stable oil-in-water emulsion (SE of CS/D in combination with the Toll-Like Receptor 4 (TLR4 agonist Glucopyranosyl Lipid A (GLA/SE, or one of two TLR7/8 agonists: R848 (un-conjugated or 3M-051 (covalently conjugated. Compared to Alum and SE, GLA/SE induced higher CS/D specific antibody response in Balb/c mice. Subclass analysis showed higher IgG2:IgG1 ratio of GLA/SE induced antibodies as compared to Alum and SE. TLR synergy was not observed when soluble R848 was mixed with GLA/SE. Antibody response of 3M051 formulations in Balb/c was similar to GLA/SE, except for the higher IgG2:IgG1 ratio and a trend towards higher T cell responses in 3M051 containing groups. However, no synergistic enhancement of antibody and T cell response was evident when 3M051 conjugate was mixed with GLA/SE. In C57Bl/6 mice, CS/D adjuvanted with 3M051/SE or GLA/SE induced higher CSP repeat specific titers compared to SE. While, 3M051 induced antibodies had high IgG2c:IgG1 ratio, GLA/SE promoted high levels of both IgG1 and IgG2c. GLA/SE also induced more potent T-cell responses compared to SE in two independent C57/BL6 vaccination studies, suggesting a balanced and productive T(H1/T(H2 response. GLA and 3M-051 similarly enhanced the protective efficacy of CS/D against challenge with a transgenic P. berghei parasite and most importantly, high levels of cytophilic IgG2 antibodies were associated with protection in this model. Our data indicated that the cGMP-grade, soluble CS/D antigen combined with the TLR4-containing adjuvant GLA/SE warrants

  20. The Rac Activator DOCK2 Mediates Plasma Cell Differentiation and IgG Antibody Production.

    Science.gov (United States)

    Ushijima, Miho; Uruno, Takehito; Nishikimi, Akihiko; Sanematsu, Fumiyuki; Kamikaseda, Yasuhisa; Kunimura, Kazufumi; Sakata, Daiji; Okada, Takaharu; Fukui, Yoshinori

    2018-01-01

    A hallmark of humoral immune responses is the production of antibodies. This process involves a complex cascade of molecular and cellular interactions, including recognition of specific antigen by the B cell receptor (BCR), which triggers activation of B cells and differentiation into plasma cells (PCs). Although activation of the small GTPase Rac has been implicated in BCR-mediated antigen recognition, its precise role in humoral immunity and the upstream regulator remain elusive. DOCK2 is a Rac-specific guanine nucleotide exchange factor predominantly expressed in hematopoietic cells. We found that BCR-mediated Rac activation was almost completely lost in DOCK2-deficient B cells, resulting in defects in B cell spreading over the target cell-membrane and sustained growth of BCR microclusters at the interface. When wild-type B cells were stimulated in vitro with anti-IgM F(ab') 2 antibody in the presence of IL-4 and IL-5, they differentiated efficiently into PCs. However, BCR-mediated PC differentiation was severely impaired in the case of DOCK2-deficient B cells. Similar results were obtained in vivo when DOCK2-deficient B cells expressing a defined BCR specificity were adoptively transferred into mice and challenged with the cognate antigen. In addition, by generating the conditional knockout mice, we found that DOCK2 expression in B-cell lineage is required to mount antigen-specific IgG antibody. These results highlight important role of the DOCK2-Rac axis in PC differentiation and IgG antibody responses.

  1. Serological blind spots for variants of human IgG3 and IgG4 by a commonly used anti-immunoglobulin reagent.

    Science.gov (United States)

    Howie, Heather L; Delaney, Meghan; Wang, Xiaohong; Er, Lay See; Vidarsson, Gestur; Stegmann, Tamara C; Kapp, Linda; Lebedev, Jenna N; Wu, Yanyun; AuBuchon, James P; Zimring, James C

    2016-12-01

    Human immunoglobulin G (IgG) includes four different subtypes (IgG1, IgG2, IgG3, and IgG4), and it is also now appreciated that there are genetic variations within IgG subtypes (called isoallotypes). Twenty-nine different isoallotypes have been described, with 7, 4, 15, and 3 isoallotypes described for IgG1, IgG2, IgG3, and IgG4, respectively. The reactivity of anti-IgG with different isoallotypes has not been characterized. A novel monoclonal anti-K antibody (PugetSound Monoclonal Antibody 1 [PUMA1]) was isolated and sequenced, and a panel of PUMA1 variants was expressed, consisting of the 29 known IgG isoallotypes. The resulting panel of antibodies was preincubated with K-positive red blood cells (RBCs) and then subjected to testing with currently approved anti-IgG by flow cytometry, solid phase systems, gel cards, and tube testing. A US Food and Drug Administration (FDA)-approved monoclonal anti-IgG (gamma-clone) failed to recognize 2 of 15 IgG3 isoallotypes (IgG3-03 and IgG3-13) and 3 of 3 IgG4 isoallotypes (IgG4-01, IgG4-02, and IgG4-03). In contrast, an FDA-approved rabbit polyclonal anti-IgG recognized each of the known human IgG isoallotypes. These findings demonstrate "blind spots" in isoalloantibody detection by a monoclonal anti-IgG. If a patient has anti-RBC antibodies predominantly of an IgG3 subtype (the IgG3-03 and/or IgG3-13 variety), then it is possible that a clinically significant alloantibody would be missed. IgG-03 and IgG-13 have an estimated frequency of 1% to 3% in Caucasian populations and 20% to 30% in certain African populations. Nonreactivity with IgG4 is a known characteristic of this monoclonal anti-IgG, but IgG4 isoallotypes have not been previously reported. © 2016 AABB.

  2. Studies of nontarget-mediated distribution of human full-length IgG1 antibody and its FAb fragment in cardiovascular and metabolic-related tissues.

    Science.gov (United States)

    Davidsson, Pia; Söderling, Ann-Sofi; Svensson, Lena; Ahnmark, Andrea; Flodin, Christine; Wanag, Ewa; Screpanti-Sundqvist, Valentina; Gennemark, Peter

    2015-05-01

    Tissue distribution and pharmacokinetics (PK) of full-length nontargeted antibody and its antigen-binding fragment (FAb) were evaluated for a range of tissues primarily of interest for cardiovascular and metabolic diseases. Mice were intravenously injected with a dose of 10 mg/kg of either human IgG1or its FAb fragment; perfused tissues were collected at a range of time points over 3 weeks for the human IgG1 antibody and 1 week for the human FAb antibody. Tissues were homogenized and antibody concentrations were measured by specific immunoassays on the Gyros system. Exposure in terms of maximum concentration (Cmax ) and area under the curve was assessed for all nine tissues. Tissue exposure of full-length antibody relative to plasma exposure was found to be between 1% and 10%, except for brain (0.2%). Relative concentrations of FAb antibody were the same, except for kidney tissue, where the antibody concentration was found to be ten times higher than in plasma. However, the absolute tissue uptake of full-length IgG was significantly higher than the absolute tissue uptake of the FAb antibody. This study provides a reference PK state for full-length whole and FAb antibodies in tissues related to cardiovascular and metabolic diseases that do not include antigen or antibody binding. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  3. Sensitive assays enable detection of serum IgG antibodies against Clostridium difficile toxin A and toxin B in healthy subjects and patients with Clostridium difficile infection.

    Science.gov (United States)

    Zhao, Xuemei; Bender, Florent; Shukla, Rajiv; Kang, John J; Caro-Aguilar, Ivette; Laterza, Omar F

    2016-04-01

    Pathogenic Clostridium difficile produces two proinflammatory exotoxins, toxin A and toxin B. Low level of serum antitoxin IgG antibodies is a risk factor for the development of primary and recurrent C. difficile infection (CDI). We developed and validated two sensitive, titer-based electrochemiluminescence assays for the detection of serum antibody levels against C. difficile toxins A and B. These assays demonstrated excellent precision. The sensitivity of the assays allowed the detection of antitoxin A and antitoxin B IgG antibodies in all tested serum samples during assay validation. The validated titer-based assays enable assessment of antitoxin A and antitoxin B IgG antibodies as potential biomarkers to identify patients with CDI at increased risk for CDI recurrence.

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

    Directory of Open Access Journals (Sweden)

    SANT'ANNA Anadayr L.M.

    2002-01-01

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

  5. Liver-X-receptor activator prevents homocysteine-induced production of IgG antibodies from murine B lymphocytes via the ROS-NF-κB pathway

    International Nuclear Information System (INIS)

    Chang Lina; Zhang, Zhenmin; Li Wenjing; Dai Jing; Guan Youfei; Wang Xian

    2007-01-01

    Our previous study showed that homosysteine (Hcy) promotes proliferation of mouse splenic B lymphocytes. In this study, we investigated whether Hcy could stimulate the production of IgG antibodies. Hcy significantly increased the production of IgG antibodies from resting B lymphocytes. B lymphocytes from ApoE-knockout mice with hyperhomocysteinemia showed elevated IgG secretion at either the basal Hcy level or in response to lipopolysaccharide. Hcy promoted reactive oxygen species (ROS) formation, and free radical scavengers, MnTMPyP decreased Hcy-induced IgG secretion. The inhibitor of NF-κB (MG132) also significantly reduced Hcy-induced IgG secretion. Furthermore, Hcy-induced formation of ROS, activation of NF-κB, and secretion of IgG could be inhibited by the liver-X-receptor (LXR) agonist TO 901317. Thus, our data provide strong evidence that HHcy induces IgG production from murine splenic B lymphocytes both in vitro and in vivo. The mechanism might be through the ROS-NF-κB pathway and can be attenuated by the activation of LXR

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

    DEFF Research Database (Denmark)

    Hjelholt, Astrid; Carlsen, Thomas Gelsing; Deleuran, Bent Winding

    2013-01-01

    Introduction: Spondyloarthritis (SpA) comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA)-B27. SpA is suggested triggered by bacterial infection, and bacterial heat shock protein (HSP) seems to be a strong T cell antigen. Since...... against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27+ patients. Only weak correlation between antibodies against bacterial and human HSP60...... was seen, and there was no indication of cross-reaction. Conclusion: These results suggest that antibodies against human HSP60 is associated with SpA, however, the theory that antibodies against human HSP60 is a specific part of the aetiology, through cross-reaction to bacterial HSP60, cannot be supported...

  7. IgM but not IgG monoclonal anti-Nocardia brasiliensis antibodies confer protection against experimental actinomycetoma in BALB/c mice.

    Science.gov (United States)

    Gonzalez-Suarez, Maria L; Salinas-Carmona, Mario C; Pérez-Rivera, Isabel

    2009-10-01

    Nocardia brasiliensis is a facultative intracellular microorganism that produces a human chronic infection known as actinomycetoma. Human and mouse anti-N. brasiliensis antibody response identify P24, P26 and P61 immunodominant antigens. In this work, we generated immunoglobulin M (IgM) and IgG monoclonal antibodies (mAbs) specific to immunodominant P61 antigen. The monoclonal IgM (NbM1) and IgG2a (NbG1) antibodies were assessed for their in vitro bactericidal activity, in vivo protective effect and ability to block catalase activity. These mAbs specifically recognized P61, but they did not inhibit its enzyme activity. The in vitro bactericidal effect of NbG1 was higher than the killing ability of the IgM mAb. In vivo experiments with a murine model of experimental infection with N. brasiliensis injected into rear footpads was used to test the effect of NbM1 and NbG1. The negative untreated group developed a chronic actinomycetoma within 4 weeks. IgM mAbs conferred protection to BALB/c mice infected with N. brasiliensis. IgG mAb lacked this protective effect. IgM mAb showed a dose-response correlation between antibody concentration and lesion size. These results demonstrate that humoral immune response mediated by antigen-specific IgM antibody protects against an intracellular bacterial infection.

  8. Assessment of pathogenesis of infective endocarditis by plasma IgG antibody titer test against periodontal bacteria.

    Science.gov (United States)

    Isoshima, Daichi; Yamashiro, Keisuke; Matsunaga, Kazuyuki; Shinobe, Michitaka; Nakanishi, Nagako; Nakanishi, Izumi; Omori, Kazuhiro; Yamamoto, Tadashi; Takashiba, Shogo

    2017-10-01

    Oral bacteria cause infective endocarditis (IE), so severe periodontitis is thought to be high risk for IE. We suggest the identification of high-risk patients by an IgG antibody titer test against periodontal bacteria might become common screening test.

  9. Comparison of IgG and IgA Antibodies Titrations against Helicobacter Pylori in Urban and Rural Populations in Mazandaran Province

    Directory of Open Access Journals (Sweden)

    Mina Owrang

    2014-06-01

    Full Text Available Background & objective: The infection caused by Helicobacter pylori (H. pylori is one of the most common bacterial gastrointestinal diseases throughout the world. Based on the role of H. pylori in a variety of diseases such as gastrointestinal and lymphoma, present study is aimed to consider the concentration of IgA and IgG against H. pylori in both rural and urban populations and then its relationship with some demographic characteristics. Materials & Methods: In this descriptive study, 400 sera samples were collected from both genders at the Sari treatment- health center. After blood collection, the concentration of IgG and IgA against H. pylori was measured by ELISA kit. Results: There was no significant difference in antibodies titration between men and women. Approximately 18.5% of males and 16.5% of females were positive regarding to IgA and 70.2% of men and 66.7% of women were positive regarding to IgG. The mean of antibodies in rural populations (0.87±0.35 was significantly (p<0.001 higher than those in urban populations (0.78±0.41. The mean of antibodies in patients who had a history of gastrointestinal infection was significantly higher than others (p<0.05. Conclusion: Due to the high level of IgA and IgG antibodies in studied populations, especially in rural people, and lack of symptoms in patients, the screen of positive serologic populations can be helpful for the management and control of infections caused by H. pylori.

  10. A Secondary Antibody-Detecting Molecular Weight Marker with Mouse and Rabbit IgG Fc Linear Epitopes for Western Blot Analysis.

    Science.gov (United States)

    Lin, Wen-Wei; Chen, I-Ju; Cheng, Ta-Chun; Tung, Yi-Ching; Chu, Pei-Yu; Chuang, Chih-Hung; Hsieh, Yuan-Chin; Huang, Chien-Chiao; Wang, Yeng-Tseng; Kao, Chien-Han; Roffler, Steve R; Cheng, Tian-Lu

    2016-01-01

    Molecular weight markers that can tolerate denaturing conditions and be auto-detected by secondary antibodies offer great efficacy and convenience for Western Blotting. Here, we describe M&R LE protein markers which contain linear epitopes derived from the heavy chain constant regions of mouse and rabbit immunoglobulin G (IgG Fc LE). These markers can be directly recognized and stained by a wide range of anti-mouse and anti-rabbit secondary antibodies. We selected three mouse (M1, M2 and M3) linear IgG1 and three rabbit (R1, R2 and R3) linear IgG heavy chain epitope candidates based on their respective crystal structures. Western blot analysis indicated that M2 and R2 linear epitopes are effectively recognized by anti-mouse and anti-rabbit secondary antibodies, respectively. We fused the M2 and R2 epitopes (M&R LE) and incorporated the polypeptide in a range of 15-120 kDa auto-detecting markers (M&R LE protein marker). The M&R LE protein marker can be auto-detected by anti-mouse and anti-rabbit IgG secondary antibodies in standard immunoblots. Linear regression analysis of the M&R LE protein marker plotted as gel mobility versus the log of the marker molecular weights revealed good linearity with a correlation coefficient R2 value of 0.9965, indicating that the M&R LE protein marker displays high accuracy for determining protein molecular weights. This accurate, regular and auto-detected M&R LE protein marker may provide a simple, efficient and economical tool for protein analysis.

  11. IgG subclass reactivity to Trypanosoma cruzi in chronic chagasic patients.

    Science.gov (United States)

    Hernández-Becerril, N; Nava, A; Reyes, P A; Monteón, V M

    2001-01-01

    The anti-Trypanosoma cruzi antibodies isotype profile in Chagas' disease has been studied in relation to different clinical manifestations. A high titer of IgG anti-T. cruzi antibodies is found in patients with cardiac involvement, while a high titer of IgA anti-T. cruzi antibodies is associated with digestive forms. The aim of this work was to analyze the IgG subclass reactivity of anti-T. cruzi antibodies in patients with chronic Chagasic cardiomyopathy. Twelve consecutive chagasic patients were analyzed for IgG subclass reactivity to a T. cruzi antigenic extract. They had a complete clinical evaluation, peripheral EKG, echocardiography, left ventriculogram, and coronariography. All patients came from rural areas of Mexico and had lived in endemic zones for over seven years. They presented left ventricular endsystolic dimension above 42 mm in 58% (7/12) and ejection fraction below 50% in 58% (7/12). We found that IgG1 and IgG2 anti-T. cruzi antibodies showed higher titer than IgG3 antibodies, with consistently low titer of IgG4 antibodies. Expression of the four IgG subclasses of anti-T. cruzi antibodies suggest a mixed Th1/Th2-like immune response under a probably continuous chronic antigenic stimulation. On the other hand, high levels of IgG2 anti-T. cruzi antibodies showed a tendency to be associated with severe cardiomegaly. Our results suggest that a mixed Th1/Th2-like immune response may take place in chronic chagasic patients under a chronic antigenic stimulation.

  12. The Rac Activator DOCK2 Mediates Plasma Cell Differentiation and IgG Antibody Production

    Directory of Open Access Journals (Sweden)

    Miho Ushijima

    2018-02-01

    Full Text Available A hallmark of humoral immune responses is the production of antibodies. This process involves a complex cascade of molecular and cellular interactions, including recognition of specific antigen by the B cell receptor (BCR, which triggers activation of B cells and differentiation into plasma cells (PCs. Although activation of the small GTPase Rac has been implicated in BCR-mediated antigen recognition, its precise role in humoral immunity and the upstream regulator remain elusive. DOCK2 is a Rac-specific guanine nucleotide exchange factor predominantly expressed in hematopoietic cells. We found that BCR-mediated Rac activation was almost completely lost in DOCK2-deficient B cells, resulting in defects in B cell spreading over the target cell-membrane and sustained growth of BCR microclusters at the interface. When wild-type B cells were stimulated in vitro with anti-IgM F(ab′2 antibody in the presence of IL-4 and IL-5, they differentiated efficiently into PCs. However, BCR-mediated PC differentiation was severely impaired in the case of DOCK2-deficient B cells. Similar results were obtained in vivo when DOCK2-deficient B cells expressing a defined BCR specificity were adoptively transferred into mice and challenged with the cognate antigen. In addition, by generating the conditional knockout mice, we found that DOCK2 expression in B-cell lineage is required to mount antigen-specific IgG antibody. These results highlight important role of the DOCK2–Rac axis in PC differentiation and IgG antibody responses.

  13. The usefulness of casein-specific IgE and IgG4 antibodies in cow's milk allergic children

    Directory of Open Access Journals (Sweden)

    Ito Komei

    2012-01-01

    Full Text Available Abstract Background Cow's milk allergy is one of the most common food allergies among younger children. We investigated IgE antibodies to milk, and IgE and IgG4 antibodies to casein, α-lactalbumin and β-lactoglobulin in cow's milk allergic (CMA and non-allergic (non-CMA children in order to study their clinical usefulness. Methods Eighty-three children with suspected milk allergy (median age: 3.5 years, range: 0.8-15.8 years were diagnosed as CMA (n = 61 or non-CMA (n = 22 based on an open milk challenge or convincing clinical history. Their serum concentrations of allergen-specific (s IgE and IgG4 antibodies were measured using ImmunoCAP®. For the sIgG4 analysis, 28 atopic and 31 non-atopic control children were additionally included (all non-milk sensitized. Results The CMA group had significantly higher levels of milk-, casein- and β-lactoglobulin-sIgE antibodies as compared to the non-CMA group. The casein test showed the best discriminating performance with a clinical decision point of 6.6 kUA/L corresponding to 100% specificity. All but one of the CMA children aged > 5 years had casein-sIgE levels > 6.6 kUA/L. The non-CMA group had significantly higher sIgG4 levels against all three milk allergens compared to the CMA group. This was most pronounced for casein-sIgG4 in non-CMA children without history of previous milk allergy. These children had significantly higher casein-sIgG4 levels compared to any other group, including the non-milk sensitized control children. Conclusions High levels of casein-sIgE antibodies are strongly associated with milk allergy in children and might be associated with prolonged allergy. Elevated casein-sIgG4 levels in milk-sensitized individuals on normal diet indicate a modified Th2 response. However, the protective role of IgG4 antibodies in milk allergy is unclear.

  14. On the role of IgG4 in inflammatory conditions: lessons for IgG4-related disease

    NARCIS (Netherlands)

    Trampert, David C.; Hubers, Lowiek M.; van de Graaf, Stan F. J.; Beuers, Ulrich

    2017-01-01

    The pathophysiology of immunoglobulin G4-related disease (IgG4-RD) and its most common manifestations, IgG4-associated (sclerosing) cholangitis and autoimmune pancreatitis, remains largely unknown, but IgG4 is presumably involved. IgG4 is a promiscuous antibody, which could be directly pathogenic,

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

    Science.gov (United States)

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

    2014-01-01

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

  16. Clearance of human IgG1-sensitised red blood cells in vivo in humans relates to the in vitro properties of antibodies from alternative cell lines.

    Directory of Open Access Journals (Sweden)

    Kathryn L Armour

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

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    A monoclonal antibody was produced against the recombinant human alpha subunit of CK-2. The antibody was of the IgG1 subclass and it was isolated from serum-free cell culture media and purified by affinity chromatography on Protein G Sepharose. The antibody can be used to detect specifically the CK......-2 alpha subunit in immunoblots from tissue extracts. An ELISA detection test was also established which also allows the identification of the CK-2 alpha subunit....

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

    Directory of Open Access Journals (Sweden)

    Hempel Franziska

    2012-09-01

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

  19. Chlamydial serum IgG, IgA and local IgA antibodies in patients with genital-tract infections measured by solid-phase radioimmunoassay

    International Nuclear Information System (INIS)

    Terho, P.; Meurman, O.

    1981-01-01

    A solid-phase radioimmunoassay (RIA) for IgG and IgA class antibodies to Chlamydia trachomatis was developed with C. trachomatis serotype L2 as antigen. The assay was sensitive, reproducible and correlated well with an immunofluorescence test (r = 0.85). Serum IgG antibodies were detected in 79% of Chlamydia isolation-positive versus 43% of isolation-negative male patients with urethritis and serum IgA antibodies in 53% and 21%, respectively. Urethral IgA antibodies, measured from specimens taken for chlamydial isolation, could be detected in 94% and 38%, respectively. From 737 male urethral and 909 female cervical secretions screened for the presence of IgA antibodies, about half were isolation and IgA negative. Only 4% (6/151) of male and 5.4% (2/37) of female isolation-positive specimens were IgA negative. The determination of local IgA antibodies may be used as a screening test in chlamydial genital infections. (author)

  20. Detection of phase I IgG antibodies to Coxiella burnetii with EIA as a screening test for blood donations.

    Science.gov (United States)

    van der Hoek, W; Wielders, C C H; Schimmer, B; Wegdam-Blans, M C A; Meekelenkamp, J; Zaaijer, H L; Schneeberger, P M

    2012-11-01

    The presence of a high phase I IgG antibody titre may indicate chronic infection and a risk for the transmission of Coxiella burnetii through blood transfusion. The outbreak of Q fever in the Netherlands allowed for the comparison of an enzyme immunoassay (EIA) with the reference immunofluorescence assay (IFA) in a large group of individuals one year after acute Q fever. EIA is 100 % sensitive in detecting high (≥1:1,024) phase I IgG antibody titres. The cost of screening with EIA and confirming all EIA-positive results with IFA is much lower than screening all donations with IFA. This should be taken into account in cost-effectiveness analyses of screening programmes.

  1. Dynamics evaluation of total IgG, IgG1 and IgG2a in the serum of mice immunized with radioattenuated paracoccidioides brasiliensis yeast cells

    International Nuclear Information System (INIS)

    Martins, Estefania M.N.; Andrade, Antero S.R.; Reis, Bernardo S.; Goes, Alfredo M.

    2007-01-01

    Paracoccidioides brasiliensis is the fungus agent of paracoccidioidomycosis, a deep-seated systemic infection of humans. Up to the moment no vaccine has still been reported. The potential of gamma radiation for pathogens attenuation and vaccine development was explored in this work. In our laboratory we developed radioattenuated yeast cells of P. brasiliensis and the aim of the present work was to evaluate the antibody production dynamics in mice immunized with this cells. Were analyzed the IgG antibodies titers as well as the type of response by analyzing the IgG1 and IgG2a antibody pattern in the course of infection. The mice were divided in two groups that were immunized one time and two times respectively. The mice infected with the virulent P. brasiliensis showed a high level of antibody production while the infection with the radioattenuated yeast did not significantly change the antibody level. The level of IgG raised in both immunized groups after the challenge. In the group immunized one time was not observed a significant difference between the levels of both subclasses when compared with the control. After the challenge of the group immunized two times the IgG2a levels increased significantly when analyzed 90 days post challenge. We concluded that a pattern related to the disease control was apparent in the group submitted to two immunizations. The mice had not developed a totally polarized pattern of TH1/TH2 response but a trend to a TH1 response was evident. (author)

  2. Dynamics evaluation of total IgG, IgG1 and IgG2a in the serum of mice immunized with radioattenuated paracoccidioides brasiliensis yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Estefania M.N.; Andrade, Antero S.R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: estefaniabio@yahoo.com.br; antero@cdtn.br; Reis, Bernardo S.; Goes, Alfredo M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia]. E-mail: brsgarbi@mono.icb.ufmg.br; goes@mono.icb.ufmg.br

    2007-07-01

    Paracoccidioides brasiliensis is the fungus agent of paracoccidioidomycosis, a deep-seated systemic infection of humans. Up to the moment no vaccine has still been reported. The potential of gamma radiation for pathogens attenuation and vaccine development was explored in this work. In our laboratory we developed radioattenuated yeast cells of P. brasiliensis and the aim of the present work was to evaluate the antibody production dynamics in mice immunized with this cells. Were analyzed the IgG antibodies titers as well as the type of response by analyzing the IgG1 and IgG2a antibody pattern in the course of infection. The mice were divided in two groups that were immunized one time and two times respectively. The mice infected with the virulent P. brasiliensis showed a high level of antibody production while the infection with the radioattenuated yeast did not significantly change the antibody level. The level of IgG raised in both immunized groups after the challenge. In the group immunized one time was not observed a significant difference between the levels of both subclasses when compared with the control. After the challenge of the group immunized two times the IgG2a levels increased significantly when analyzed 90 days post challenge. We concluded that a pattern related to the disease control was apparent in the group submitted to two immunizations. The mice had not developed a totally polarized pattern of TH1/TH2 response but a trend to a TH1 response was evident. (author)

  3. Isolation of high-affinity human IgE and IgG antibodies recognising Bet v 1 and Humicola lanuginosa lipase from combinatorial phage libraries

    DEFF Research Database (Denmark)

    Jakobsen, Charlotte G; Bødtger, Uffe; Kristensen, Peter

    2004-01-01

    Allergen-specific Fab fragments isolated from combinatorial IgE and IgG libraries are useful tools for studying allergen-antibody interactions. To characterise the interaction between different allergens and antibodies we have created recombinant human phage antibody libraries in the Fab format...

  4. Fluorescent IgG fusion proteins made in E. coli

    Science.gov (United States)

    Luria, Yael; Raichlin, Dina; Benhar, Itai

    2012-01-01

    Antibodies are among the most powerful tools in biological and biomedical research and are presently the fastest growing category of new bio-pharmaceutics. The most common format of antibody applied for therapeutic, diagnostic and analytical purposes is the IgG format. For medical applications, recombinant IgGs are made in cultured mammalian cells in a process that is too expensive to be considered for producing antibodies for diagnostic and analytical purposes. Therefore, for such purposes, mouse monoclonal antibodies or polyclonal sera from immunized animals are used. While looking for an easier and more rapid way to prepare full-length IgGs for therapeutic purposes, we recently developed and reported an expression and purification protocol for full-length IgGs, and IgG-based fusion proteins in E. coli, called “Inclonals.” By applying the Inclonals technology, we could generate full-length IgGs that are genetically fused to toxins. The aim of the study described herein was to evaluate the possibility of applying the “Inclonals” technology for preparing IgG-fluorophore fusion proteins. We found that IgG fused to the green fluorescent proteins enhanced GFP (EGFP) while maintaining functionality in binding, lost most of its fluorescence during the refolding process. In contrast, we found that green fluorescent Superfolder GFP (SFGFP)-fused IgG and red fluorescent mCherry-fused IgG were functional in antigen binding and maintained fluorescence intensity. In addition, we found that we can link several SFGFPs in tandem to each IgG, with fluorescence intensity increasing accordingly. Fluorescent IgGs made in E. coli may become attractive alternatives to monoclonal or polyclonal fluorescent antibodies derived from animals. PMID:22531449

  5. IgG4 antibodies in Egyptian patients with schistosomiasis

    NARCIS (Netherlands)

    Iskander, R.; Das, P. K.; Aalberse, R. C.

    1981-01-01

    Serum immunoglobulins were determined in 40 Egyptian patients with schistosomiasis. In addition to the well-established elevation in total IgE, a striking imbalance in the IgG subclass levels was found: IgG3 and IgG4 levels were markedly elevated, whereas IgG2 levels were normal. The IgG4 level did

  6. Prospective estimation of IgG, IgG subclass and IgE antibodies to dietary proteins in infants with cow milk allergy. Levels of antibodies to whole milk protein, BLG and ovalbumin in relation to repeated milk challenge and clinical course of cow milk allergy

    DEFF Research Database (Denmark)

    Høst, A; Husby, S; Gjesing, B

    1992-01-01

    Prospectively, serum levels of IgE, specific IgE antibodies (AB) to whole cow milk protein (CMP), bovine se-albumin, bovine immunoglobulin, bovine lactoferrin, bovine lactalbumin and beta-lactoglobulin (BLG), IgG and IgG subclass antibodies to ovalbumin (OA) and BLG, and IgG4 RAST to CMP (bovine...... whey) were measured in 39 infants with cow milk protein allergy (CMPA) at birth (cord blood), at time of diagnosis and before and after milk challenge at the age of 12 months. Immunological measurements were also undertaken in 33 control infants without CMPA at birth, at 6 months and at 18 months...... of the type of CMPA (IgE-mediated (CMA) or non-IgE-mediated (CMI)), and irrespective of whether remission had occurred. In cord blood 25/33 (76%) of the infants with CMPA had specific IgE-AB to one or more of the bovine milk proteins indicating a prenatal intrauterine sensitization to cow milk protein. At 6...

  7. Humanised IgG1 antibody variants targeting membrane-bound carcinoembryonic antigen by antibody-dependent cellular cytotoxicity and phagocytosis.

    Science.gov (United States)

    Ashraf, S Q; Umana, P; Mössner, E; Ntouroupi, T; Brünker, P; Schmidt, C; Wilding, J L; Mortensen, N J; Bodmer, W F

    2009-11-17

    The effect of glycoengineering a membrane specific anti-carcinoembryonic antigen (CEA) (this paper uses the original term CEA for the formally designated CEACAM5) antibody (PR1A3) on its ability to enhance killing of colorectal cancer (CRC) cell lines by human immune effector cells was assessed. In vivo efficacy of the antibody was also tested. The antibody was modified using EBNA cells cotransfected with beta-1,4-N-acetylglucosaminyltransferase III and the humanised hPR1A3 antibody genes. The resulting alteration of the Fc segment glycosylation pattern enhances the antibody's binding affinity to the FcgammaRIIIa receptor on human immune effector cells but does not alter the antibody's binding capacity. Antibody-dependent cellular cytotoxicity (ADCC) is inhibited in the presence of anti-FcgammaRIII blocking antibodies. This glycovariant of hPR1A3 enhances ADCC 10-fold relative to the parent unmodified antibody using either unfractionated peripheral blood mononuclear or natural killer (NK) cells and CEA-positive CRC cells as targets. NK cells are far more potent in eliciting ADCC than either freshly isolated monocytes or granulocytes. Flow cytometry and automated fluorescent microscopy have been used to show that both versions of hPR1A3 can induce antibody-dependent cellular phagocytosis (ADCP) by monocyte-derived macrophages. However, the glycovariant antibody did not mediate enhanced ADCP. This may be explained by the relatively low expression of FcgammaRIIIa on cultured macrophages. In vivo studies show the efficacy of glycoengineered humanised IgG1 PR1A3 in significantly improving survival in a CRC metastatic murine model. The greatly enhanced in vitro ADCC activity of the glycoengineered version of hPR1A3 is likely to be clinically beneficial.

  8. High levels of IgG4 antibodies to foods during infancy are associated with tolerance to corresponding foods later in life.

    Science.gov (United States)

    Tomicić, Sara; Norrman, Gunilla; Fälth-Magnusson, Karin; Jenmalm, Maria C; Devenney, Irene; Böttcher, Malin Fagerås

    2009-02-01

    Children with eczema and sensitization to foods are recommended skin care and, if food allergy is proven by challenge, an elimination diet. For most children the diet period is transient, but the process behind tolerance development and the influence of decreased allergen exposure is not fully known. The aim of the study was to investigate the effect of elimination diet on serum and salivary antibodies and to identify immunological parameters related to the ability to tolerate foods. Eighty-nine children, below 2 yr of age, with eczema and suspected food allergy were included. Recommended treatment was skin care to all children, and 60 children had a period of elimination diet. At 4(1/2) yr of age, the children were divided into two groups, based on if they had been able to introduce the eliminated foods, or not. Serum and salivary antibodies were analyzed with enzyme-linked immunosorbent assay and UniCAP before and after a 6-wk treatment period and at 4(1/2) yr of age. Children sensitized to egg and/or milk that could eat and drink the offending foods at 4(1/2) yr of age, had higher levels of Immunoglobulin G(4) antibodies to ovalbumin and beta-lactoglobulin and also higher IgG(4)/Immunoglobulin E ratios on inclusion in the study, than those who had to eliminate egg and/or milk from their diet, beyond 4(1/2) yr of age. The highest IgG(4)/IgE ratios were found in children with circulating IgE antibodies to egg and/or milk but negative skin prick test on inclusion. The 6-wk treatment period did not significantly affect the levels of serum and salivary antibodies. In conclusion, eczematous, food sensitized infants with high levels of IgG(4) and high ratios of IgG(4)/IgE antibodies to food allergens are more likely to consume these foods at 4(1/2) yr than infants with low levels and ratios.

  9. Influenza virus neutralizing antibodies and IgG isotype profiles after immunization of mice with influenza A subunit vaccine using various adjuvants

    NARCIS (Netherlands)

    Benne, CA; Harmsen, M; vanderGraaff, W; Verheul, AFM; Snippe, H; Kraaijeveld, CA

    The influence of various adjuvants on the development of influenza virus neutralizing antibodies and distribution of anti-influenza virus IgG isotypes after immunization of mice with influenza A (H3N2) subunit vaccine was investigated. Serum titres of influenza virus neutralizing antibodies and

  10. What is IgG4? A review of the biology of a unique immunoglobulin subtype.

    Science.gov (United States)

    Nirula, Ajay; Glaser, Scott M; Kalled, Susan L; Taylor, Frederick R; Taylora, Frederick R

    2011-01-01

    Recent descriptions of the group of clinical disorders collectively defined as IgG4-related systemic disease (IgG4-RSD) have prompted this review of the unique biology of the IgG4 antibody. This article will discuss IgG4 structure and function, the unique phenomenon of half-antibody exchange, and the implications of IgG4 biology for its proposed role in immunologic diseases. IgG4 antibodies have unique structural and functional properties and undergo 'half-antibody exchange' in vivo, resulting in recombined antibodies composed of two different binding specificities. The production of IgG4 antibodies appears to be driven in part by T helper 2 (Th2) cytokines that mediate allergic responses and IgE production. Although serum IgG4 levels in healthy individuals vary significantly, data from multiple sclerosis (MS) patients suggest tight regulation of individual IgG4 levels over time. IgG4-RSD represents a diverse group of clinical disorders unified by elevated IgG4 levels and specific histopathologic findings. A key unanswered question is whether IgG4, a relatively weak activator of effector cells, is pathogenic in these disorders. IgG4 is a unique antibody biologically and structurally. Increased understanding of its precise role in the clinical syndromes that comprise IgG4-RSD may ultimately elucidate the underlying pathogenesis.

  11. Pathological manifestations in lymphatic filariasis correlate with lack of inhibitory properties of IgG4 antibodies on IgE-activated granulocytes.

    Science.gov (United States)

    Prodjinotho, Ulrich F; von Horn, Charlotte; Debrah, Alex Y; Batsa Debrah, Linda; Albers, Anna; Layland, Laura E; Hoerauf, Achim; Adjobimey, Tomabu

    2017-07-01

    Helminth parasites are known to be efficient modulators of their host's immune system. To guarantee their own survival, they induce alongside the classical Th2 a strong regulatory response with high levels of anti-inflammatory cytokines and elevated plasma levels of IgG4. This particular antibody was shown in different models to exhibit immunosuppressive properties. How IgG4 affects the etiopathology of lymphatic filariasis (LF) is however not well characterized. Here we investigate the impact of plasma and affinity-purified IgG/IgG4 fractions from endemic normals (EN) and LF infected pathology patients (CP), asymptomatic microfilaraemic (Mf+) and amicrofilaraemic (Mf-) individuals on IgE/IL3 activated granulocytes. The activation and degranulation states were investigated by monitoring the expression of CD63/HLADR and the release of granule contents (neutrophil elastase (NE), eosinophil cationic protein (ECP) and histamine) respectively by flow cytometry and ELISA. We could show that the activation of granulocytes was inhibited in the presence of plasma from EN and Mf+ individuals whereas those of Mf- and CP presented no effect. This inhibitory capacity was impaired upon depletion of IgG in Mf+ individuals but persisted in IgG-depleted plasma from EN, where it strongly correlated with the expression of IgA. In addition, IgA-depleted fractions failed to suppress granulocyte activation. Strikingly, affinity-purified IgG4 antibodies from EN, Mf+ and Mf- individuals bound granulocytes and inhibited activation and the release of ECP, NE and histamine. In contrast, IgG4 from CP could not bind granulocytes and presented no suppressive capacity. Reduction of both the affinity to, and the suppressive properties of anti-inflammatory IgG4 on granulocytes was reached only when FcγRI and II were blocked simultaneously. These data indicate that IgG4 antibodies from Mf+, Mf- and EN, in contrast to those of CP, natively exhibit FcγRI/II-dependent suppressive properties on

  12. Correlation between the Amount of Anti-D Antibodies and IgG Subclasses with Severity of Haemolytic Disease of Foetus and Newborn.

    Science.gov (United States)

    Velkova, Emilija

    2015-06-15

    The aim of this study was to investigate the influence of subclasses to IgG anti-D on the intensity of hemolytic disease of fetus and newborn (HDFN) at 45 fetuses/newborns with symptoms of mild and severe HDFN in Republic of Macedonia. In retrospective and prospective studies, in a period of 10 years, from 2004 to 2014, there have been immunohemathology tests performed on 22 009 samples on serums of pregnant women. At 37.78% of the total number of tested patients, IgG1 and IgG3 was the reason for severe HDFN. At 17.77% of the total number of tested patients, which had only IgG1detected, was the reason for serious intensity of HDFN. The correlation of the titer to anti-D antibodies in the mother's serum and the intensity of HDFN were researched in 48 newborns. The titers between 1:8 and 1:32 resulted in 3 cases of HDFN with symptoms of severe disease and in 4 cases there were no signs of HDFN. At 12 women that had a titre between 1:32 and 1:512, five of the newborns developed severe HDFN, and seven had symptoms of mild and weak intensity form. In 3 cases the titer was higher than 512, and out of them one newborn had weak symptoms of HDFN, one developed severe HDFN and one ended with foetal death. Only in one case the titer reached a value higher than 1000, and it ended with a fetal death. The titers of the pregnant women serum those are lower than 32 and those higher than 1000 can well predict HDFN. The titers of anti-D antibodies between 64 and 512 have no exact predictive value. IgG1 and IgG3 subclasses of anti-D have no predictive value by themselves, and cannot foresee the outcome of HDFN. The research study results suggest that IgG1 and IgG3 should be included in a multi - parameter protocol for evaluation of the HDFN intensity. They can give a real assessment of the expected HDFN intensity in combination with the titer hight and the significance of the antibodies.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Surinder Batra

    2006-01-01

    Current therapeutic approaches against the advanced stages of human solid tumors are palliative rather than curative. Many modalities, including, surgery, radiation, and chemotherapy, either alone or in combination have met with only modest success for advanced metastatic cancers. Radioimmunotherapy (RIT) combines the specificity of monoclonal antibodies with cytotoxic effects of radioisotopes. It is the ''smart'' way of delivering radiation to the known and occult metastatic cancer cells and is independent of drug toxicity and/or hormone resistance. The tumor associated glycoprotein-72 (TAG-72) containing the unique disaccharide sialyl-Tn, is highly expressed in majority of adenocarcinomas, including carcinomas of the prostate, breast, ovaries, pancreas and colon (80-90%) compared to undetectable expression in normal tissues. Monoclonal antibody CC49, reactive with TAG-72, after conjugation to potent gamma- and beta-emitting radionuclides, has been useful in selective systemic radiolocalization of disease and therapy of primary and metastatic tumor sites. However, limited therapeutic responses were observed in patients. Limited success of antibody based delivery of radioisotopes can be attributed to several factors including undesirable pharmacokinetics, poor tumor uptake and high immunogenicity of intact antibodies (IgGs). The primary factors contributing towards the failure of RIT include: (1) longer serum half-lives of the intact IgG molecules resulting in the radiotoxicity, (2) generation of human antibodies against murine antibodies (HAMA) that limits the frequency of dose administration, (3) poor diffusion rates of intact IgG due to the large size and (4) high interstitial fluid pressures (IFP) encountered in solid tumors. The major goal of our multidisciplinary project was to develop specific novel radiopharmaceuticals, with desired pharmacokinetics, for the diagnosis and therapy of solid tumors. To overcome the low uptake of radioactivity by tumors and to

  15. Association of beta2-glycoprotein I IgG and IgM antibodies with thrombosis and thrombocytopenia

    DEFF Research Database (Denmark)

    Voss, Anne-Sofie Boertmann; Jacobsen, Søren; Heegaard, Niels Henrik Helweg

    2001-01-01

    Antiphospholipid antibodies (APA) have been known for decades. Their relation to clinical manifestations, primarily thromboses and thrombocytopenia, was recognised in the 1980s. In this clinical study two cohorts of patients, a population-based (84 patients with systemic lupus erythematosus (SLE......)) and a hospital-based (87 patients with SLE and 53 with other connective tissue diseases) were investigated for APA and associated clinical manifestations. Anticardiolipin antibodies (ACA) of IgG and IgM classes were found in 13 and 38% of the population-based patients and in 29 and 58% of the hospital...

  16. Differential antibody isotype reactivity to specific antigens in human lymphatic filariasis: gp15/400 preferentially induces immunoglobulin E (IgE), IgG4, and IgG2

    NARCIS (Netherlands)

    Yazdanbakhsh, M.; Paxton, W. A.; Brandenburg, A.; van Ree, R.; Lens, M.; Partono, F.; Maizels, R. M.; Selkirk, M. E.

    1995-01-01

    Lymphatic filarial infection in humans is associated with a strong skewing of the immune response towards the TH2 arm, with prominent interleukin 4-producing cells and elevated levels of immunoglobulin G4 (IgG4) and IgE antibodies in peripheral blood. To determine how such a generalized TH2

  17. Infectious Mononucleosis Triggers Generation of IgG Auto-Antibodies against Native Myelin Oligodendrocyte Glycoprotein.

    Science.gov (United States)

    Kakalacheva, Kristina; Regenass, Stephan; Wiesmayr, Silke; Azzi, Tarik; Berger, Christoph; Dale, Russell C; Brilot, Fabienne; Münz, Christian; Rostasy, Kevin; Nadal, David; Lünemann, Jan D

    2016-02-12

    A history of infectious mononucleosis (IM), symptomatic primary infection with the Epstein Barr virus, is associated with the development of autoimmune diseases and increases the risk to develop multiple sclerosis. Here, we hypothesized that immune activation during IM triggers autoreactive immune responses. Antibody responses towards cellular antigens using a HEp-2 based indirect immunofluorescence assay and native myelin oligodendrocyte glycoprotein (MOG) using a flow cytometry-based assay were determined in 35 patients with IM and in 23 control subjects. We detected frequent immunoglobulin M (IgM) reactivity to vimentin, a major constituent of the intermediate filament family of proteins, in IM patients (27/35; 77%) but rarely in control subjects (2/23; 9%). IgG autoantibodies binding to HEp-2 cells were absent in both groups. In contrast, IgG responses to native MOG, present in up to 40% of children with inflammatory demyelinating diseases of the central nervous system (CNS), were detectable in 7/35 (20%) patients with IM but not in control subjects. Normalization of anti-vimentin IgM levels to increased total IgM concentrations during IM resulted in loss of significant differences for anti-vimentin IgM titers. Anti-MOG specific IgG responses were still detectable in a subset of three out of 35 patients with IM (9%), even after normalization to increased total IgG levels. Vimentin-specific IgM and MOG-specific IgG responses decreased following clinical resolution of acute IM symptoms. We conclude from our data that MOG-specific memory B cells are activated in subset of patients with IM.

  18. Evaluation of cysticercus-specific IgG (total and subclasses and IgE antibody responses in cerebrospinal fluid samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies Avaliação das respostas de anticorpos anti-cisticercos IgG (total e subclasses e IgE em amostras de líquido cefalorraquidiano de pacientes com neurocisticercose apresentando produção intratecal de anticorpos específicos IgG

    Directory of Open Access Journals (Sweden)

    Lisandra Akemi Suzuki

    2013-01-01

    Full Text Available In the present study, an enzyme-linked immunosorbent assay (ELISA standardized with vesicular fluid of Taenia solium cysticerci was used to screen for IgG (total and subclasses and IgE antibodies in cerebrospinal fluid (CSF samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies and patients with other neurological disorders. The following results were obtained: IgG-ELISA: 100% sensitivity (median of the ELISA absorbances (MEA=1.17 and 100% specificity; IgG1-ELISA: 72.7% sensitivity (MEA=0.49 and 100% specificity; IgG2-ELISA: 81.8% sensitivity (MEA=0.46 and 100% specificity; IgG3-ELISA: 63.6% sensitivity (MEA=0.12 and 100% specificity; IgG4-ELISA: 90.9% sensitivity (MEA=0.85 and 100% specificity; IgE-ELISA 93.8% sensitivity (MEA=0.60 and 100% specificity. There were no significant differences between the sensitivities and specificities in the detection of IgG-ELISA and IgE-ELISA, although in CSF samples from patients with neurocysticercosis the MEA of the IgG-ELISA was significantly higher than that of the IgE-ELISA. The sensitivity and MEA values of the IgG4-ELISA were higher than the corresponding values for the other IgG subclasses. Future studies should address the contribution of IgG4 and IgE antibodies to the physiopathology of neurocysticercosis.No presente estudo, uma reação imunoenzimática (ELISA padronizada com o fluido vesicular de cisticercos de Taenia solium foi utilizada para avaliar as respostas de anticorpos anti-cisticercos IgG (total e subclasses e IgE em amostras de líquido cefalorraquidiano (LCR de pacientes com neurocisticercose apresentando produção intratecal de anticorpos específicos IgG e pacientes com outras desordens neurológicas. Os seguintes resultados foram obtidos: ELISA-IgG: 100% de sensibilidade (mediana das absorbâncias das reações ELISA (MAE=1,17 e especificidade 100%; ELISA-IgG1: sensibilidade 72,7% (MAE=0,49 e especificidade 100%; ELISA-IgG2

  19. Prevalence of rubella-specific IgG antibodies in unimmunized young female population

    Directory of Open Access Journals (Sweden)

    Jayakrishnan Thayyil

    2016-01-01

    Full Text Available Context: Rubella is a mild self-limiting disease all over the world; nevertheless, it is of significant public health importance due to its teratogenic effect of congenital rubella syndrome. Rubella vaccine is currently not included in the national immunization program in India. Rubella-specific IgG in the unvaccinated population is a marker of previous rubella infection. Rubella IgG estimation in children will provide data for initiation and necessary modification to the immunization strategy. Aims: In this background, this study was conducted with an aim to know the age-specific susceptibility of acquiring rubella infections and future risk of congenital rubella syndrome (CRS among girls. Settings and Design: This was a community-based, observational study. Participants and Methods: The study was conducted at a randomly selected rural area Mavoor Panchayath of Kozhikode District, Kerala, among adolescent girls. The estimation of rubella-specific IgG antibody was done by quantitative enzyme-linked immunosorbent assay method. IgG titer value of >15 IU was taken positive, 8-15 IU as equivocal, and <8 IU as negative. Statistical Analysis Used: Statistical analysis was performed using Statistical program for Social science version 16 for Windows. Chi-square test was applied to find out significant difference and Fisher′s exact test wherever applicable. Results: The data and blood sample collection was done from 250 girls. The mean IgG titer was 151.93 ± 128.78 IU, and as per the criteria, 68.3% were positive, 28.5% were negative, and 3.2% were equivocal. At this age, majority (68.3% of the girls get protection by natural infection without any vaccine. Some girls (32% may remain susceptible to infection during adulthood and pregnancy. Conclusions: Natural rubella infection was widely prevalent among child population and at this age. An immunization policy recommending rubella-containing vaccine is highly desirable to prevent rubella and CRS.

  20. Generation and characterisation of murine monoclonal antibodies specific for cervine immunoglobulin light chain, IgM and IgG

    International Nuclear Information System (INIS)

    Hibma, M.; Griffin, J.F.T.

    1992-01-01

    Monoclonal antibodies (mAb) which react with cervine immunoglobulin (Ig) light chain, IgM and IgG were produced using conventional cell fusion technology. Hybridoma supernatants were initially screened for specificity against cervine Ig using an enzyme-linked immunosorbent assay (ELISA). The specificity of supernatants against size-fractionated cervine Ig was further determined. Supernatants were characterised using western blotting and autoradiographic techniques. The mAb OU1G, OU2G and OU3G were specific for cervine gamma-chain of IgG, whereas OU1L was specific for light chain of Ig. A further mAb (OU1M) bound IgM and not IgG. These mAb were found to have varying cross-reactivity against Ig from other species

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

    Directory of Open Access Journals (Sweden)

    Dale O Starkie

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

  2. Generation and characterization of antibodies against Asian elephant (Elephas maximus IgG, IgM, and IgA.

    Directory of Open Access Journals (Sweden)

    Alan F Humphreys

    Full Text Available Asian elephant (Elephas maximus immunity is poorly characterized and understood. This gap in knowledge is particularly concerning as Asian elephants are an endangered species threatened by a newly discovered herpesvirus known as elephant endotheliotropic herpesvirus (EEHV, which is the leading cause of death for captive Asian elephants born after 1980 in North America. While reliable diagnostic assays have been developed to detect EEHV DNA, serological assays to evaluate elephant anti-EEHV antibody responses are lacking and will be needed for surveillance and epidemiological studies and also for evaluating potential treatments or vaccines against lethal EEHV infection. Previous studies have shown that Asian elephants produce IgG in serum, but they failed to detect IgM and IgA, further hampering development of informative serological assays for this species. To begin to address this issue, we determined the constant region genomic sequence of Asian elephant IgM and obtained some limited protein sequence information for putative serum IgA. The information was used to generate or identify specific commercial antisera reactive against IgM and IgA isotypes. In addition, we generated a monoclonal antibody against Asian elephant IgG. These three reagents were used to demonstrate that all three immunoglobulin isotypes are found in Asian elephant serum and milk and to detect antibody responses following tetanus toxoid booster vaccination or antibodies against a putative EEHV structural protein. The results indicate that these new reagents will be useful for developing sensitive and specific assays to detect and characterize elephant antibody responses for any pathogen or vaccine, including EEHV.

  3. Seropositivity and determinants of immunoglobulin-G (IgG ...

    African Journals Online (AJOL)

    Background: This study is the first documented prevalence of IgG antibody against HSV-1&-2 in Port Harcourt, Nigeria and thus provides baseline data for future in-depth studies on HSV infection in South-South, Nigeria. Objective: This study determined the seropositivity and determinants of serum IgG antibody against ...

  4. A solid-phase radioimmunoassay for IgG gliadin antibodies using 125I-labelled staphylococcal protein A

    International Nuclear Information System (INIS)

    Troncone, R.; Pignata, C.; Farris, E.; Ciccimarra, F.

    1983-01-01

    A sensitive radioimmunoassay for IgG gliadin antibodies is described. Serum specimens were added to wells of plastic microtitre plates coated with gliadin. After removal of the unbound material, gliadin antibodies were detected by adding 125 I-labelled staphylococcal protein A ( 125 I-SpA). Serum specimens from coeliac patients on a normal diet or on a gluten-free diet were tested, as well as sera from an age-matched control group. Measurements to obtain precise quantitative values were made with gliadin antibody-rich serum as reference standard. High titres of gliadin antibodies were found in 18 out of 19 coeliac patients on a normal diet (95%); in patients on a strict gluten-free diet serum values did not exceed 2 S.D. of the control mean. Due to the high sensitivity of the method a low but detectable amount of gliadin antibody was present in the sera of all controls. (Auth.)

  5. Solid-phase radioimmunoassay for IgG gliadin antibodies using /sup 125/I-labelled staphylococcal protein A

    Energy Technology Data Exchange (ETDEWEB)

    Troncone, R.; Pignata, C.; Farris, E.; Ciccimarra, F. (Naples Univ. (Italy). II Facolta di Medicina)

    1983-10-14

    A sensitive radioimmunoassay for IgG gliadin antibodies is described. Serum specimens were added to wells of plastic microtitre plates coated with gliadin. After removal of the unbound material, gliadin antibodies were detected by adding /sup 125/I-labelled staphylococcal protein A (/sup 125/I-SpA). Serum specimens from coeliac patients on a normal diet or on a gluten-free diet were tested, as well as sera from an age-matched control group. Measurements to obtain precise quantitative values were made with gliadin antibody-rich serum as reference standard. High titres of gliadin antibodies were found in 18 out of 19 coeliac patients on a normal diet (95%); in patients on a strict gluten-free diet serum values did not exceed 2 S.D. of the control mean. Due to the high sensitivity of the method a low but detectable amount of gliadin antibody was present in the sera of all controls.

  6. Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses.

    Science.gov (United States)

    Tay, Matthew Zirui; Liu, Pinghuang; Williams, LaTonya D; McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T; Dennison, S Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S Munir; Moody, M Anthony; Hope, Thomas J; Haynes, Barton F; Tomaras, Georgia D

    2016-08-01

    Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine

  7. Sialylated Autoantigen-Reactive IgG Antibodies Attenuate Disease Development in Autoimmune Mouse Models of Lupus Nephritis and Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Yannic C. Bartsch

    2018-06-01

    Full Text Available Pro- and anti-inflammatory effector functions of IgG antibodies (Abs depend on their subclass and Fc glycosylation pattern. Accumulation of non-galactosylated (agalactosylated; G0 IgG Abs in the serum of rheumatoid arthritis and systemic lupus erythematosus (SLE patients reflects severity of the diseases. In contrast, sialylated IgG Abs are responsible for anti-inflammatory effects of the intravenous immunoglobulin (pooled human serum IgG from healthy donors, administered in high doses (2 g/kg to treat autoimmune patients. However, whether low amounts of sialylated autoantigen-reactive IgG Abs can also inhibit autoimmune diseases is hardly investigated. Here, we explore whether sialylated autoantigen-reactive IgG Abs can inhibit autoimmune pathology in different mouse models. We found that sialylated IgG auto-Abs fail to induce inflammation and lupus nephritis in a B cell receptor (BCR transgenic lupus model, but instead are associated with lower frequencies of pathogenic Th1, Th17 and B cell responses. In accordance, the transfer of small amounts of immune complexes containing sialylated IgG Abs was sufficient to attenuate the development of nephritis. We further showed that administration of sialylated collagen type II (Col II-specific IgG Abs attenuated the disease symptoms in a model of Col II-induced arthritis and reduced pathogenic Th17 cell and autoantigen-specific IgG Ab responses. We conclude that sialylated autoantigen-specific IgG Abs may represent a promising tool for treating pathogenic T and B cell immune responses in autoimmune diseases.

  8. IgG4 autoantibodies against muscle-specific kinase undergo Fab-arm exchange in myasthenia gravis patients.

    Science.gov (United States)

    Koneczny, Inga; Stevens, Jo A A; De Rosa, Anna; Huda, Saif; Huijbers, Maartje G; Saxena, Abhishek; Maestri, Michelangelo; Lazaridis, Konstantinos; Zisimopoulou, Paraskevi; Tzartos, Socrates; Verschuuren, Jan; van der Maarel, Silvère M; van Damme, Philip; De Baets, Marc H; Molenaar, Peter C; Vincent, Angela; Ricciardi, Roberta; Martinez-Martinez, Pilar; Losen, Mario

    2017-02-01

    Autoimmunity mediated by IgG4 subclass autoantibodies is an expanding field of research. Due to their structural characteristics a key feature of IgG4 antibodies is the ability to exchange Fab-arms with other, unrelated, IgG4 molecules, making the IgG4 molecule potentially monovalent for the specific antigen. However, whether those disease-associated antigen-specific IgG4 are mono- or divalent for their antigens is unknown. Myasthenia gravis (MG) with antibodies to muscle specific kinase (MuSK-MG) is a well-recognized disease in which the predominant pathogenic IgG4 antibody binds to extracellular epitopes on MuSK at the neuromuscular junction; this inhibits a pathway that clusters the acetylcholine (neurotransmitter) receptors and leads to failure of neuromuscular transmission. In vitro Fab-arm exchange-inducing conditions were applied to MuSK antibodies in sera, purified IgG4 and IgG1-3 sub-fractions. Solid-phase cross-linking assays were established to determine the extent of pre-existing and inducible Fab-arm exchange. Functional effects of the resulting populations of IgG4 antibodies were determined by measuring inhibition of agrin-induced AChR clustering in C2C12 cells. To confirm the results, κ/κ, λ/λ and hybrid κ/λ IgG4s were isolated and tested for MuSK antibodies. At least fifty percent of patients had IgG4, but not IgG1-3, MuSK antibodies that could undergo Fab-arm exchange in vitro under reducing conditions. Also MuSK antibodies were found in vivo that were divalent (monospecific for MuSK). Fab-arm exchange with normal human IgG4 did not prevent the inhibitory effect of serum derived MuSK antibodies on AChR clustering in C2C12 mouse myotubes. The results suggest that a considerable proportion of MuSK IgG4 could already be Fab-arm exchanged in vivo. This was confirmed by isolating endogenous IgG4 MuSK antibodies containing both κ and λ light chains, i.e. hybrid IgG4 molecules. These new findings demonstrate that Fab-arm exchanged antibodies

  9. Radioimmunolocalization and selective delivery of radiation in a rat model system: comparison of intact and fragmented antibody

    International Nuclear Information System (INIS)

    Walker, K.Z.; Seymour-Munn, K.; Axiak, S.M.; Raison, R.L.; Basten, A.; Towson, J.E.; Bautovitch, G.J.; Morris, J.

    1988-01-01

    Monoclonal antibody (MoAb) fragments are known to have advantages over intact immunoglobulins for radioimmunoscintigraphy. It is less clear whether they are as effective in the delivery of radioimmunotherapy. The imaging and dosimetric properties of an intact MoAb, K-1-21, reactive against human kappa light chains (LC) were compared with that of its F(ab') 2 and Fab fragments using a normal rat model system. Two days after injection of 131 I-K-1-21 into rats bearing antigen-sepharose implants, gamma camera images showed specific localization of the MoAb to the target (kappa LC) but not to the control (lambda LC) implant. Better images were obtained with K-1-21 F(ab') 2 than with Fab or intact antibody. Mean kappa implant: blood ratios were 8.6 ± 3.9 for Fab, 7.9 ± 1.8 for F(ab') 2 and 2.0 ± 0.3 for intact K-1-21. The improvement associated with the use of 131 I-K-1-21 fragments was, however, achieved at the expense of lower absolute values of activity at the target site. Thus the absorbed dose delivered to the implant by the intact K-1-21 was double that delivered with F(ab') 2 and six times that delivered with Fab. As intact K-1-21 also delivered a greater radiation dose to normal tissues, F(ab') 2 fragments may have the greatest overall advantages for therapy with radionuclide MoAb conjugates. (author)

  10. Seroprevalence of Toxoplasma gondii IgG antibody in HIV/AIDS-infected individuals in Maputo, Mozambique

    Directory of Open Access Journals (Sweden)

    Abílio Domingos

    2013-10-01

    Full Text Available OBJECTIVE To analyze the prevalence of IgG antibodies to Toxoplasma gondii in patients infected with HIV/AIDS and the association of demographic and social variables. METHODS Descriptive cross-sectional study that included the analysis of sociodemographic data and laboratory findings of 200 patients infected with HIV/AIDS treated in a laboratory unit in Maputo, Mozambique, in 2010. Individual data for all participants were collected with a self-administered questionnaire. Plasma samples were tested for IgG testing of anti- T. gondii using hemagglutination for the analysis of antibodies. RESULTS The seroprevalence of IgG anti- T. gondii was 46.0% (95%CI 39.2;52.9, 39.3% (95%CI 29.5;50.0 in men and 50.9% (95%CI 41.9;59.8 in women, with no difference between sex (OR 1.30; 95%CI 0.95;1.77; p = 0.12. Ages ranged from 10 to 60 years, with a higher prevalence of infection in older age groups, but with no significant difference between them. Regularly consuming cattle meat (OR 1.74; 95%CI 1.04;2.89, p = 0.05, breeding cats/dogs (OR 6.18; 95%CI 3.60;10.62, p < 0.000 and having regular contact with soil (OR 3.38; 95%CI 2.19;5.21; p < 0.000 were significantly associated with risk of latent infection. CONCLUSIONS Toxoplasmosis is an infection with high prevalence in Mozambique. Cultural and behavioral aspects increase the risk. Toxoplasmosis can be responsible in our environment by the great burden of morbidity and mortality associated with meningoencephalic injuries in patients with HIV/AIDS.

  11. Perfil de isotipos de imunoglobulinas e subclasses de IgG na leishmaniose tegumentar americana Immunoglobulin isotype and IgG subclass profiles in american tegumentary leishmaniasis

    Directory of Open Access Journals (Sweden)

    Maria Aparecida de Souza

    2005-04-01

    Full Text Available O presente trabalho avaliou o perfil de anticorpos em amostras de soro de 37 pacientes com diagnóstico clínico confirmado ou compatível com leishmaniose tegumentar americana atendidos no Hospital de Clínicas da Universidade Federal de Uberlândia, MG. Os perfis das classes de imunoglobulinas e subclasses de IgG foram analisados pelo teste ELISA indireto, utilizando-se antígeno solúvel de Leishmania (Leishmania amazonensis. A avidez dos anticorpos foi determinada pelo tratamento com uréia a 6 M, após incubação dos soros com o antígeno. Observou-se que 97%, 94,6%, 57,5 e 21,5% das amostras testadas apresentaram anticorpos anti-Leishmania das classes IgE, IgG, IgA e IgM, respectivamente e, os perfis das subclasses de IgG demonstraram, IgG1>IgG3>IgG2>IgG4. Os anticorpos IgE anti-Leishmania de alta avidez corresponderam a 44,4%. Por outro lado, IgG e IgA anti-Leishmania foram em sua maioria (62,8 e 47,8%, respectivamente, de média avidez. A variação do perfil de isotipos, bem como a avidez das imunoglobulinas refletiu a complexidade da resposta imune humoral contra a leishmaniose tegumentar americana.The present work investigated the serum antibody profiles in 37 patients with American tegumentary leishmaniasis, who were attended at Hospital de Clinicas - Universidade Federal de Uberlandia, MG, Brazil. The immunoglobulin class and IgG subclass profiles were analyzed by indirect ELISA using Leishmania (Leishmania amazonensis soluble antigen. The antibody avidity was determined by 6 M urea treatment after incubation with immunoenzymatic conjugate. It was observed that 97% of the serum samples presented anti-Leishmania antibodies for IgE class, 94.6% IgG, 57.5% IgA and 21.5% IgM class. For IgG subclasses the profiles were in the following order of frequency: IgG1>IgG3>IgG2>IgG4. High avidity of anti-Leishmania IgE antibodies was found in 44.4% of the samples. On the other hand, moderate avidity of specific IgG and IgA was observed in 62

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

    Science.gov (United States)

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

    2012-04-30

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

  13. Evaluation of Immunity and Seropositivity of IgG Antibodies to Canine Parvoviruses in Vaccinated and Unvaccinated Dogs in Abeokuta, Nigeria.

    Science.gov (United States)

    Babalola, E T; Ijaopo, O K; Okonko, I O

    2016-01-01

    Canine Parvovirus (CPV) is a very contagious and virulent viral disease affecting domestic dogs all over the world causing high morbidity and mortality in dogs, especially puppies. This study aimed at determining the seropositivity of IgG antibodies against CPV in vaccinated and unvaccinated dogs and to evaluate the immune status of dogs presented in Abeokuta. Forty-eight dogs were enrolled in this study. These dogs were presented at random for treatment, routine checkup, and vaccination at the State Veterinary Hospital and Veterinary Teaching Hospital all in Abeokuta. All the dogs were fully maintained under domestic setting. Selection for study was done based on thorough examination of the dogs and their medical records. The clients were informed of the nature of the investigation. Blood samples were collected and analyzed for anti-CPV-IgG. In principle, protective immunity correlates with high antibody titers and this was determined using a commercially available immunocomb® test kit for anti-CPV IgG antibody. Of 48 dogs sampled, 38 (79.2%) had high level of anti-CPV antibody titer and 10 (20.8%) had low level of anti-CPV antibody titer. Twenty six (54.2%) were males while 22 (45.8%) were females. Forty-five (93.75%) dogs were exotic breeds while 3 (6.25%) dogs were mongrels. Thirty (62.5%) of the dogs were less than one year old and the age range of all dogs sampled was between 7 weeks and 7 years. There was no significant difference (P > 0.05) between sex and the level of immunity but significant differences (P canine parvovirus among dogs in Abeokuta, Nigeria. Of all variables evaluated, ages of dogs, breeds and post-vaccination period were the main correlates of the level of immunity to CPV. This study also showed agreement with previous studies in the diagnostic value of using the immunoblot ELISA assay for the rapid detection of anti-CPV IgG antibody.

  14. Effect of IgG subclasses on in vivo bioavailability and metabolic fate of immune-complexed insulin in Lewis rats

    International Nuclear Information System (INIS)

    Arquilla, E.R.; Stenger, D.; McDougall, B.; Ulich, T.R.

    1987-01-01

    The bioavailability, distribution, and metabolic fate of 125 I-labeled insulin complexed to antibodies in guinea pig antiserum, purified guinea pig IgG1, IgG2, a mixture of IgG1 and IgG2, and homologous Lou/m rat antiserum were studied in inbred Lewis rats. 125 I-insulin complexed to purified guinea pig IgG2 antibodies was rapidly cleared from the blood and sequestered in increasing amounts with time in the liver. Large amounts of the 125 I-insulin complexed to guinea pig IgG1 antibodies remained in the blood for at least 30 min. The bioavailability of 125 I-insulin bound to IgG1 and IgG2 antibodies was inhibited for at least 30 min because significantly less was available for rapid binding to insulin receptors on hepatocytes and renal tubular cells and its subsequent rapid degradation. The bioavailability of 125 I-insulin was further decreased when bound to antibodies in native guinea pig antiserum or a mixture of IgG1 and IgG2 antibodies compared with the 125 I-insulin complexed to either purified IgG1 or IgG2 antibodies alone. The 125 I-insulin bound to antibodies in native guinea pig antiserum or a mixture of IgG1 and IgG2 antibodies was distributed in vivo in a manner reflecting the relative concentrations of the IgG1 and IgG2 antibodies present. The bioavailability, distribution, and metabolic fate of 125 I-insulin in immune complexes prepared with homologous Lou/m rat insulin antiserum was qualitatively similar to that observed with immune complexes prepared with guinea pig insulin antiserum. It appears that the Lewis rat can be used as an in vivo model to study the bioavailability,distribution,and metabolic fate of insulin bound to xenogenic or homologous insulin antibodies

  15. Solid-phase radioimmunoassay for the detection fo IgG antibodies to gramineae pollen (Dactylis glomerata) and to acarida (dermatophagoides Pteronyssinus)

    Energy Technology Data Exchange (ETDEWEB)

    Guilloux, L.; Ville, G.

    1985-01-01

    A solid-phase radioimmunoassay using SVI-protein A onto polystyrene microplates, was applied successfully for the detection of IgG antibodies to acarida and to grass pollen in allergic patients and in patients undergoing desensitization therapy.

  16. Serum IgG antibodies from healthy subjects up to 100 years old react to JC polyomavirus.

    Science.gov (United States)

    Bononi, Ilaria; Mazzoni, Elisa; Pietrobon, Silvia; Manfrini, Marco; Torreggiani, Elena; Rossini, Marika; Lotito, Francesca; Guerra, Giovanni; Rizzo, Paola; Martini, Fernanda; Tognon, Mauro

    2018-08-01

    JC polyomavirus (JCPyV) was identified in 1971 in the brain tissue of a patient (J.C.) affected by the progressive multifocal leukoencephalopathy (PML). JCPyV encodes for the oncoproteins large T antigen (Tag) and small t-antigen (tag). These oncoproteins are responsible of the cell transformation and tumorigenesis in experimental animals. JCPyV is ubiquitous in human populations. After the primary infection, which is usually asymptomatic, JCPyV remains lifelong in the host in a latent phase. Its reactivation may occur in heathy subjects and immunocompromised patients. Upon reactivation, JCPyV could reach (i) the CNS inducing the PML, (ii) the kidney of transplant patients causing the organ rejection. Association between JCPyV, which is a small DNA tumor virus, and gliomas and colorectal carcinomas has been published. In the present investigation, we report on a new indirect ELISA with two specific synthetic peptides mimicking JCPyV VP1 immunogenic epitopes to detect specific serum IgG antibodies against JCPyV. Serum samples of healthy subjects (n = 355) ranging 2-100 years old, were analyzed by this new indirect ELISA. The linear peptides VP1 K and VP1 N resemble the natural JCPyV VP1 capsidic epitopes constituting a docking site for serum antibodies. Data from this innovative immunologic assay indicate that the overall prevalence of JCPyV-VP1 antibodies in healthy subjects is at 39%. The innovative indirect ELISA with JCPyV VP1 mimotopes seems to be a useful method to detect specific IgG antibodies against this virus, without cross-reactivity with the closely related SV40 and BKPyV polyomaviruses. © 2018 Wiley Periodicals, Inc.

  17. Combined roles of human IgG subclass, alternative complement pathway activation, and epitope density in the bactericidal activity of antibodies to meningococcal factor h binding protein.

    Science.gov (United States)

    Giuntini, Serena; Reason, Donald C; Granoff, Dan M

    2012-01-01

    Meningococcal vaccines containing factor H binding protein (fHbp) are in clinical development. fHbp binds human fH, which enables the meningococcus to resist complement-mediated bacteriolysis. Previously, we found that chimeric human IgG1 mouse anti-fHbp monoclonal antibodies (MAbs) had human complement-mediated bactericidal activity only if the MAb inhibited fH binding. Since IgG subclasses differ in their ability to activate complement, we investigated the role of human IgG subclasses on antibody functional activity. We constructed chimeric MAbs in which three different murine fHbp-specific binding domains were each paired with human IgG1, IgG2, or IgG3. Against a wild-type group B isolate, all three IgG3 MAbs, irrespective of their ability to inhibit fH binding, had bactericidal activity that was >5-fold higher than the respective IgG1 MAbs, while the IgG2 MAbs had the least activity. Against a mutant with increased fHbp expression, the anti-fHbp MAbs elicited greater C4b deposition (classical pathway) and greater bactericidal activity than against the wild-type strain, and the IgG1 MAbs had similar or greater activity than the respective IgG3 MAbs. The bactericidal activity against both wild-type and mutant strains also was dependent, in part, on activation of the alternative complement pathway. Thus, at lower epitope density in the wild-type strain, the IgG3 anti-fHbp MAbs had the greatest bactericidal activity. At a higher epitope density in the mutant, the IgG1 MAbs had similar or greater bactericidal activity than the IgG3 MAbs, and the activity was less dependent on the inhibition of fH binding than at a lower epitope density.

  18. Trends in the patterns of IgM and IgG antibodies in febrile persons with suspected dengue in Barbados, an English-speaking Caribbean country, 2006–2013

    Directory of Open Access Journals (Sweden)

    Alok Kumar

    2015-11-01

    Full Text Available Summary: Long-term seroprevalence studies of dengue have provided a measure of the degree of endemicity and future trends in disease prevalence and severity. In this study, we describe the seroprevalence of dengue antibodies in febrile persons with suspected acute dengue in Barbados. It is a retrospective population-based study of all febrile persons with suspected dengue from 2006 to 2013. All of the cases had IgM and IgG antibodies in the blood sample drawn between days 3 and 5 of their illness. Among the 8296 cases that were tested for IgM antibodies, 3037 (36.6% had recent dengue infection. In the age groups 20 years, 23.3%, 39.6% and 35.5% had acute infection, respectively. Of the 7227 cases with documented IgG results, 5473 (75.7% were positive and had a past infection. In the age groups 20 years, 31.2%, 65.2% and 86.6%, respectively, had a past infection (IgG positive. During the first 5 years of life, 10–20% of febrile persons investigated for dengue had a positive IgM and a negative IgG titer, between 5 and 10% had a positive IgM and IgG titer, 5% had a positive IgG and a negative IgM titer, and between 45% and 65% had a negative IgM and a negative IgG titer. Throughout the study period, between 12% and 20% of febrile persons failed to show any evidence of current or previous dengue. In the age groups 20 years, 45.0%, 18.8% and 7.2%, respectively, had no evidence of recent or past dengue (both IgM and IgG negative. Between 37% and 59% of the febrile persons had serological evidence of past dengue in the absence of any current dengue. In conclusion, the pattern of IgG antibodies in this study was comparable to those in countries known to be hyperendemic for dengue. The age of infection is likely to shift to younger adults and children who are more likely to have severe dengue in the future. Keywords: Dengue, Seroprevalence, Febrile, Caribbean

  19. IgG4-Related Disease Combined with Autoimmune Hemolytic Anemia and Steroid-Responsive Transient Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Sho Hasegawa

    2015-01-01

    Full Text Available A 67-year-old man with elevated serum immunoglobulin G4 (IgG4 levels, systemic lymphadenopathy infiltrated by IgG4-positive plasma cells, and Coombs-positive autoimmune hemolytic anemia (AIHA showed marked hypercalcemia. Although the intact parathyroid hormone (PTH level was elevated, 99mTc-MIBI scintigraphy and thyroid ultrasonography revealed no evidence of primary hyperparathyroidism. Liver biopsy showed marked infiltration of IgG4-positive plasma cells, which confirmed the diagnosis of IgG4-related disease (IgG4-RD. Corticosteroid therapy was initiated, and subsequently, intact PTH and serum calcium levels gradually normalized. Transient hypercalcemia in a patient with AIHA may therefore be associated with IgG4-RD.

  20. Differential expression of IgE and IgG4 specific antibody responses in asymptomatic and chronic human filariasis

    NARCIS (Netherlands)

    Kurniawan, A.; Yazdanbakhsh, M.; van Ree, R.; Aalberse, R.; Selkirk, M. E.; Partono, F.; Maizels, R. M.

    1993-01-01

    A population of 164 adult individuals resident in an area endemic for Brugia malayi lymphatic filariasis has been studied for humoral immune responses to filarial parasites. Antibody levels to Ag extracted from adult worms were determined for each of the IgG subclasses, for IgM and for IgE. The

  1. Relative stabilities of IgG1 and IgG4 Fab domains: Influence of the light–heavy interchain disulfide bond architecture

    Science.gov (United States)

    Heads, James T; Adams, Ralph; D'Hooghe, Lena E; Page, Matt J T; Humphreys, David P; Popplewell, Andrew G; Lawson, Alastair D; Henry, Alistair J

    2012-01-01

    The stability of therapeutic antibodies is a prime pharmaceutical concern. In this work we examined thermal stability differences between human IgG1 and IgG4 Fab domains containing the same variable regions using the thermofluor assay. It was found that the IgG1 Fab domain is up to 11°C more stable than the IgG4 Fab domain containing the same variable region. We investigated the cause of this difference with the aim of developing a molecule with the enhanced stability of the IgG1 Fab and the biological properties of an IgG4 Fc. We found that replacing the seven residues, which differ between IgG1 CH1 and IgG4 CH1 domains, while retaining the native IgG1 light-heavy interchain disulfide (L–H) bond, did not affect thermal stability. Introducing the IgG1 type L–H interchain disulfide bond (DSB) into the IgG4 Fab resulted in an increase in thermal stability to levels observed in the IgG1 Fab with the same variable region. Conversely, replacement of the IgG1 L–H interchain DSB with the IgG4 type L–H interchain DSB reduced the thermal stability. We utilized the increased stability of the IgG1 Fab and designed a hybrid antibody with an IgG1 CH1 linked to an IgG4 Fc via an IgG1 hinge. This construct has the expected biophysical properties of both the IgG4 Fc and IgG1 Fab domains and may therefore be a pharmaceutically relevant format. PMID:22761163

  2. Solid-phase radioimmunoassay for the detection fo IgG antibodies to gramineae pollen (Dactylis glomerata) and to acarida (dermatophagoides Pteronyssinus)

    International Nuclear Information System (INIS)

    Guilloux, L.; Ville, G.

    1985-01-01

    A solid-phase radioimmunoassay using 125 I-protein A onto polystyrene microplates, was applied successfully for the detection of IgG antibodies to acarida and to grass pollen in allergic patients and in patients undergoing desensitization therapy [fr

  3. Measurement of the IgG2 response to Pneumococcal capsular polysaccharides may identify an antibody deficiency in individuals referred for immunological investigation.

    Science.gov (United States)

    Parker, Antony; Irure Ventura, Juan; Sims, Dawn; Echeverría de Carlos, Ainara; Gómez de la Torre, Ricardo; Tricas Aizpún, Lourdes; Ocejo-Vinyals, J Gonzalo; López-Hoyos, Marcos; Wallis, Gregg; Harding, Stephen

    2017-01-01

    IgG2 is the most efficient subclass for providing protection against pneumococcal pathogens. We hypothesised that some individuals may be unable to mount an effective pneumococcal capsular polysaccharide (PCP) IgG2 response despite having a normal PCP IgG concentration (PCP IgG2 deficient). The median pre-vaccination PCP IgG2 concentration was significantly lower in individuals referred for immunological investigation compared to healthy controls (2.8 mg/L range, 95% CI 1.1-88 vs. 29.5mg/L, 95% CI 13.5-90, p = 0.0002). PCP IgG:IgG2 ratios were significantly higher for the referral population than for healthy controls suggesting the increased production of PCP specific subclasses other than IgG2. The percentage of individuals with PCP IgG2 deficiency was significantly higher in referral groups compared to controls (31% vs. 5%; p = 0.0009) and in an individual with PCP IgG2 deficiency, the balance of PCP specific IgG subclass antibodies post vaccination changed from IgG2>IgG1>IgG3>IgG4 to IgG1>IgG3>IgG2>IgG4. The median PCP IgG2 concentration in those with PCP IgG2 deficiency was significantly lower in the referral groups compared to controls (7.8 mg/L, 95% CI 1.1-12 vs. 12.7 mg/L, 95% CI 11.8-13.1; p = 0.006). The data suggests a defect in the production PCP IgG2 may be present in individuals with normal PCP IgG referred for immunological investigation.

  4. Serum IgG antibody levels to periodontal microbiota are associated with incident Alzheimer disease.

    Directory of Open Access Journals (Sweden)

    James M Noble

    Full Text Available Periodontitis and Alzheimer disease (AD are associated with systemic inflammation. This research studied serum IgG to periodontal microbiota as possible predictors of incident AD.Using a case-cohort study design, 219 subjects (110 incident AD cases and 109 controls without incident cognitive impairment at last follow-up, matched on race-ethnicity, were drawn from the Washington Heights-Inwood Columbia Aging Project (WHICAP, a cohort of longitudinally followed northern Manhattan residents aged >65 years. Mean follow-up was five years (SD 2.6. In baseline sera, serum IgG levels were determined for bacteria known to be positively or negatively associated with periodontitis (Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans Y4, Treponema denticola, Campylobacter rectus, Eubacterium nodatum, and Actinomyces naeslundii genospecies-2. In all analyses, we used antibody threshold levels shown to correlate with presence of moderate-severe periodontitis.Mean age was 72 years (SD 6.9 for controls, and 79 years (SD 4.6 for cases (p640 ng/ml, present in 10% of subjects was associated with increased risk of AD (HR = 2.0, 95%CI: 1.1-3.8. This association was stronger after adjusting for other significant titers (HR = 3.1, 95%CI: 1.5-6.4. In this model, high anti-E. nodatum IgG (>1755 ng/ml; 19% of subjects was associated with lower risk of AD (HR = 0.5, 95%CI: 0.2-0.9.Serum IgG levels to common periodontal microbiota are associated with risk for developing incident AD.

  5. IgG4-Related Sclerosing Cholangitis.

    Science.gov (United States)

    Nakazawa, Takahiro; Shimizu, Shuya; Naitoh, Itaru

    2016-08-01

    More men than women develop immunoglobulin G4-related sclerosing cholangitis (IgG4-SC). Age at clinical onset is significantly older in patients with IgG4-SC. Patients with IgG4-SC appear similar to those with cholangiocarcinoma and primary sclerosing cholangitis (PSC). The association between IgG4-SC and autoimmune pancreatitis (AIP) is useful for the diagnosis of IgG4-SC. However, some IgG4-SC cases are isolated from AIP and are difficult to diagnose. The authors focus on three distinct features of IgG4-SC. First, diffuse inflammation induces a longer stenosis on cholangiography in contrast to the short stenosis of patients with PSC. Second, fibroinflammatory involvement is observed mainly in the stroma of the bile duct wall, whereas the bile duct epithelium is intact. Third, steroid therapy results in remarkable improvement. Although the prognosis of patients with IgG4-SC is good, some cases have developed portal hypertension and liver cirrhosis during their clinical course. Further study is needed to elucidate the long-term outcomes and mechanism of IgG4-SC. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

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

    DEFF Research Database (Denmark)

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

    1993-01-01

    Monoclonal mouse IgG3 antibody (ABL 364) against the carbohydrate Le(y) antigen enhanced infection in vitro with HTLV-1 and with HIV-1 when propagated in both transformed and normal lymphocytes. Enhancement was independent of complement, occurred with both lymphocytes and monocytes as target cells...

  7. Comparison of in-house biotin-avidin tetanus IgG enzyme-linked-immunosorbent assay (ELISA) with gold standard in vivo mouse neutralization test for the detection of low level antibodies.

    Science.gov (United States)

    Sonmez, Cemile; Coplu, Nilay; Gozalan, Aysegul; Akin, Lutfu; Esen, Berrin

    2017-06-01

    Detection of anti-tetanus antibody levels is necessary for both determination of the immune status of individuals and also for planning preventive measures. ELISA is the preferred test among in vitro tests however it can be affected by the cross reacting antibodies. A previously developed in-house ELISA test was found not reliable for the antibody levels ≤1.0IU/ml. A new method was developed to detect low antibody levels correctly. The aim of the present study was to compare the results of the newly developed in-house biotin-avidin tetanus IgG ELISA test with the in vivo mouse neutralization test, for the antibody levels ≤1.0IU/ml. A total of 54 serum samples with the antibody levels of three different levels, =0.01IU/ml, 0.01-0.1IU/ml, 0.1-1IU/ml, which were detected by in vivo mouse neutralization test were studied by the newly developed in-house biotin-avidin tetanus IgG ELISA test. Test was validated by using five different concentrations (0.01IU/ml, 0.06IU/ml, 0.2IU/ml, 0.5IU/ml, 1.0IU/ml). A statistically significant correlation (r 2 =0.9967 p=0,001) between in vivo mouse neutralization test and in-house biotin-avidin tetanus IgG ELISA test, was observed. For the tested concentrations intra-assay, inter-assay, accuracy, sensitivity, specificity and coefficients of variations were determined as ≤15%. In-house biotin-avidin tetanus IgG ELISA test can be an alternative method to in vivo mouse neutralization method for the detection of levels ≤1.0IU/ml. By using in-house biotin-avidin tetanus IgG ELISA test, individuals with non protective levels, will be reliably detected. Copyright © 2017. Published by Elsevier B.V.

  8. Site-specific proteolytic degradation of IgG monoclonal antibodies expressed in tobacco plants.

    Science.gov (United States)

    Hehle, Verena K; Lombardi, Raffaele; van Dolleweerd, Craig J; Paul, Mathew J; Di Micco, Patrizio; Morea, Veronica; Benvenuto, Eugenio; Donini, Marcello; Ma, Julian K-C

    2015-02-01

    Plants are promising hosts for the production of monoclonal antibodies (mAbs). However, proteolytic degradation of antibodies produced both in stable transgenic plants and using transient expression systems is still a major issue for efficient high-yield recombinant protein accumulation. In this work, we have performed a detailed study of the degradation profiles of two human IgG1 mAbs produced in plants: an anti-HIV mAb 2G12 and a tumour-targeting mAb H10. Even though they use different light chains (κ and λ, respectively), the fragmentation pattern of both antibodies was similar. The majority of Ig fragments result from proteolytic degradation, but there are only a limited number of plant proteolytic cleavage events in the immunoglobulin light and heavy chains. All of the cleavage sites identified were in the proximity of interdomain regions and occurred at each interdomain site, with the exception of the VL /CL interface in mAb H10 λ light chain. Cleavage site sequences were analysed, and residue patterns characteristic of proteolytic enzymes substrates were identified. The results of this work help to define common degradation events in plant-produced mAbs and raise the possibility of predicting antibody degradation patterns 'a priori' and designing novel stabilization strategies by site-specific mutagenesis. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  9. Effects of genetic engineering on the pharmacokinetics of antibodies

    International Nuclear Information System (INIS)

    Colcher, D.; Goel, A.; Pavlinkova, G.; Beresford, G.; Booth, B.; Batra, S.K.

    1999-01-01

    Monoclonal antibodies (MAbs) may be considered 'magic bullets' due to their ability to recognize and eradicate malignant cells. MAbs, however, have practical limitations for their rapid application in the clinics. The structure of the antibody molecules can be engineered to modify functional domains such as antigen-binding sites and/or effectors functions. Advanced in genetic engineering have provided rapid progress the development of new immunoglobulin constructs of MAbs with defined research and therapeutic application. Recombinant antibody constructs are being engineered, such as human mouse chimeric, domain-dispositioned, domain-deleted, humanized and single-chain Fv fragments. Genetically-engineered antibodies differ in size and rate of catabolism. Pharmacokinetics studies show that the intact IgG (150 kD), enzymatically derived fragments Fab' (50 kD) and single chain Fv (28 kD) have different clearance rates. These antibody forms clear 50% from the blood pool in 2.1 days, 30 minutes and 10 minutes, respectively. Genetically-engineered antibodies make a new class of immunotherapeutic tracers for cancer treatment

  10. Proteolysis breaks tolerance toward intact α345(IV) collagen, eliciting novel anti-GBM autoantibodies specific for α345NC1 hexamers

    Science.gov (United States)

    Olaru, Florina; Wang, Xu-Ping; Luo, Wentian; Ge, Linna; Miner, Jeffrey H; Kleinau, Sandra; Geiger, Xochiquetzal J.; Wasiluk, Andrew; Heidet, Laurence; Kitching, A. Richard; Borza, Dorin-Bogdan

    2012-01-01

    Goodpasture disease is an autoimmune kidney disease mediated by autoAbs against NC1 monomers of α3(IV) collagen that bind to the glomerular basement membrane (GBM), usually causing rapidly progressive glomerulonephritis. We identified a novel type of human IgG4-restricted anti-GBM autoAbs associated with mild non-progressive glomerulonephritis, which specifically targeted α345NC1 hexamers but not α3NC1 monomers. The mechanisms eliciting these anti-GBM autoAbs were investigated in mouse models recapitulating this phenotype. Wild type and FcγRIIB−/− mice immunized with autologous murine GBM NC1 hexamers produced mouse IgG1-restricted autoAbs specific for α345NC1 hexamers, which bound to the GBM in vivo but did not cause glomerulonephritis. In these mice, intact collagen IV from murine GBM was not immunogenic. However, in Col4a3−/− Alport mice, both intact collagen IV and NC1 hexamers from murine GBM elicited IgG antibodies specific for α3α4α5NC1 hexamers, which were not subclass restricted. As heterologous antigen in COL4A3-humanized mice, murine GBM NC1 hexamers elicited mouse IgG1, IgG2a and IgG2b autoAbs specific for α345NC1 hexamers and induced anti-GBM Ab glomerulonephritis. These findings indicate that tolerance toward autologous intact α3α4α5(IV) collagen is established in hosts expressing this antigen, even though autoreactive B cells specific for α345NC1 hexamers are not purged from their repertoire. Proteolysis selectively breaches this tolerance by generating autoimmunogenic α3α4α5NC1 hexamers. This provides a mechanism eliciting autoAbs specific for α345NC1 hexamers, which are restricted to non-inflammatory IgG subclasses and non-nephritogenic. In Alport syndrome, lack of tolerance toward α3α4α5(IV) collagen promotes production of alloantibodies to α345NC1 hexamers, including pro-inflammatory IgG subclasses which mediate post-transplant anti-GBM nephritis. PMID:23303673

  11. Detection of phase I IgG antibodies to Coxiella burnetii with EIA as a screening test for blood donations

    NARCIS (Netherlands)

    van der Hoek, W.; Wielders, C. C. H.; Schimmer, B.; Wegdam-Blans, M. C. A.; Meekelenkamp, J.; Zaaijer, H. L.; Schneeberger, P. M.

    2012-01-01

    The presence of a high phase I IgG antibody titre may indicate chronic infection and a risk for the transmission of Coxiella burnetii through blood transfusion. The outbreak of Q fever in the Netherlands allowed for the comparison of an enzyme immunoassay (EIA) with the reference immunofluorescence

  12. Serum IgG antibody levels to periodontal microbiota are associated with incident Alzheimer disease.

    Science.gov (United States)

    Noble, James M; Scarmeas, Nikolaos; Celenti, Romanita S; Elkind, Mitchell S V; Wright, Clinton B; Schupf, Nicole; Papapanou, Panos N

    2014-01-01

    Periodontitis and Alzheimer disease (AD) are associated with systemic inflammation. This research studied serum IgG to periodontal microbiota as possible predictors of incident AD. Using a case-cohort study design, 219 subjects (110 incident AD cases and 109 controls without incident cognitive impairment at last follow-up), matched on race-ethnicity, were drawn from the Washington Heights-Inwood Columbia Aging Project (WHICAP), a cohort of longitudinally followed northern Manhattan residents aged >65 years. Mean follow-up was five years (SD 2.6). In baseline sera, serum IgG levels were determined for bacteria known to be positively or negatively associated with periodontitis (Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans Y4, Treponema denticola, Campylobacter rectus, Eubacterium nodatum, and Actinomyces naeslundii genospecies-2). In all analyses, we used antibody threshold levels shown to correlate with presence of moderate-severe periodontitis. Mean age was 72 years (SD 6.9) for controls, and 79 years (SD 4.6) for cases (pthe sample. In a model adjusting for baseline age, sex, education, diabetes mellitus, hypertension, smoking, prior history of stroke, and apolipoprotein E genotype, high anti-A. naeslundii titer (>640 ng/ml, present in 10% of subjects) was associated with increased risk of AD (HR = 2.0, 95%CI: 1.1-3.8). This association was stronger after adjusting for other significant titers (HR = 3.1, 95%CI: 1.5-6.4). In this model, high anti-E. nodatum IgG (>1755 ng/ml; 19% of subjects) was associated with lower risk of AD (HR = 0.5, 95%CI: 0.2-0.9). Serum IgG levels to common periodontal microbiota are associated with risk for developing incident AD.

  13. Monovalent IgG4 molecules

    Science.gov (United States)

    Wilkinson, Ian C.; Fowler, Susan B.; Machiesky, LeeAnn; Miller, Kenneth; Hayes, David B.; Adib, Morshed; Her, Cheng; Borrok, M. Jack; Tsui, Ping; Burrell, Matthew; Corkill, Dominic J.; Witt, Susanne; Lowe, David C.; Webster, Carl I.

    2013-01-01

    Antibodies have become the fastest growing class of biological therapeutics, in part due to their exquisite specificity and ability to modulate protein-protein interactions with a high biological potency. The relatively large size and bivalency of antibodies, however, limits their use as therapeutics in certain circumstances. Antibody fragments, such as single-chain variable fragments and antigen binding-fragments, have emerged as viable alternatives, but without further modifications these monovalent formats have reduced terminal serum half-lives because of their small size and lack of an Fc domain, which is required for FcRn-mediated recycling. Using rational engineering of the IgG4 Fc domain to disrupt key interactions at the CH3-CH3 interface, we identified a number of point mutations that abolish Fc dimerization and created half-antibodies, a novel monovalent antibody format that retains a monomeric Fc domain. Introduction of these mutations into an IgG1 framework also led to the creation of half-antibodies. These half-antibodies were shown to be soluble, thermodynamically stable and monomeric, characteristics that are favorable for use as therapeutic proteins. Despite significantly reduced FcRn binding in vitro, which suggests that avidity gains in a dimeric Fc are critical to optimal FcRn binding, this format demonstrated an increased terminal serum half-life compared with that expected for most alternative antibody fragments. PMID:23567207

  14. Merkel cell polyomavirus IgG antibody levels are associated with progression to AIDS among HIV-infected individuals.

    Science.gov (United States)

    Vahabpour, Rouhollah; Nasimi, Maryam; Naderi, Niloofar; Salehi-Vaziri, Mostafa; Mohajel, Nasir; Sadeghi, Farzin; Keyvani, Hossein; Monavari, Seyed Hamidreza

    2017-04-01

    The association of Merkel cell polyomavirus (MCP y V) with Merkel cell carcinoma (MCC) in immunocompromised individuals has been revealed in a number of surveys. The study of MCP y V specific antibody titers and viral loads in such patients has a great attraction for research groups interested in viral reactivation. In this cross-sectional study to evaluate MCP y V antibody titer, DNA prevalence and viral load in peripheral blood mononuclear cells (PBMCs), we examined 205 HIV-1 infected patients and 100 un-infected controls. The HIV-1 infected patients divided into two groups (HIV/AIDS and non-AIDS) according to their CD4 status. Total IgG antibody titer against MCP y V was analyzed by virus like particle (VLP)-based enzyme linked immunosorbent assay (ELISA). Presence of MCP y V-DNA in subject's PBMCs was examined by quantitative real-time PCR assay. Levels of anti-MCP y V IgG in HIV/AIDS patients were significantly higher than those in non-AIDS HIV-infected and control subjects (p value = <0.001). The prevalence rate of MCP y V-DNA in PBMCs of HIV/AIDS, non-AIDS HIV-infected and un-infected controls were 17%, 16%, and 14% respectively. The MCP y V viral load among the groups ranged between 0.15 to 2.9 copies/10 3 cells (median, 1.9 copies/10 3 cells), with no significant difference between the studied populations (p value = 0.3).

  15. IgG4 autoantibodies are inhibitory in the autoimmune disease bullous pemphigoid.

    Science.gov (United States)

    Zuo, Yagang; Evangelista, Flor; Culton, Donna; Guilabert, Antonio; Lin, Lin; Li, Ning; Diaz, Luis; Liu, Zhi

    2016-09-01

    The IgG4 subclass of antibodies exhibits unique characteristics that suggest it may function in an immunoregulatory capacity. The inhibitory function of IgG4 has been well documented in allergic disease by the demonstration of IgG4 blocking antibodies, but similar functions have not been explored in autoimmune disease. Bullous pemphigoid (BP) is a subepidermal autoimmune blistering disease characterized by autoantibodies directed against BP180 and an inflammatory infiltrate including eosinophils and neutrophils. Animal models have revealed that the NC16A region within BP180 harbors the critical epitopes necessary for autoantibody mediated disease induction. BP180 NC16A-specific IgG belong to the IgG1, IgG3, and IgG4 subclasses. The purpose of this study was to determine effector functions of different IgG subclasses of NC16A-specific autoantibodies in BP. We find that IgG4 anti-NC16A autoantibodies inhibit the binding of IgG1 and IgG3 autoantibodies to the NC16A region. Moreover, IgG4 anti-NC16A blocks IgG1 and IgG3 induced complement fixation, neutrophil infiltration, and blister formation clinically and histologically in a dose-dependent manner following passive transfer to humanized BP180-NC16A mice. These findings highlight the inhibitory role of IgG4 in autoimmune disease and have important implications for the treatment of BP as well as other antibody mediated inflammatory and autoimmune diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The role of IgG antibodies in allergy and immunotherapy

    NARCIS (Netherlands)

    Aalberse, R.

    2011-01-01

    In specific immunotherapy (SIT), a beneficial response is associated with an increase in allergen-specific IgG(4) . This does not indicate that IgE-producing B cells have switched to IgG(4) production, because in human DNA, IgE is downstream from IgG(4) . Thus, by conventional switching, B cells

  17. Antibodies to poliovirus detected by immunoradiometric assay with a monoclonal antibody

    International Nuclear Information System (INIS)

    Spitz, M.; Fossati, C.A.; Schild, G.C.; Spitz, L.; Brasher, M.

    1982-01-01

    An immunoradiometric assay (IRMA) for the assay of antibodies to poliovirus antigens is described. Dilutions of the test sera or whole (finger prick) blood samples were incubated with the poliovirus antigen bound to a solid phase and the specific antibody was detected by the addition of a mouse anti-human IgG monoclonal antibody (McAb), which was itself revealed by iodinated sheep IgG antimouse F(ab). The authors have shown that this technique is suitable for the estimation of IgG anti-poliovirus antibodies induced in children following polio vaccine. The present study shows that SPRIA provides a simple and inexpensive method for serological studies with poliovirus particularly for use in large-scale surveys. (Auth.)

  18. Antibodies to poliovirus detected by immunoradiometric assay with a monoclonal antibody

    Energy Technology Data Exchange (ETDEWEB)

    Spitz, M.; Fossati, C.A.; Schild, G.C.; Spitz, L.; Brasher, M. (National Inst. for Biological Standards and Control, London (UK))

    1982-10-01

    An immunoradiometric assay (IRMA) for the assay of antibodies to poliovirus antigens is described. Dilutions of the test sera or whole (finger prick) blood samples were incubated with the poliovirus antigen bound to a solid phase and the specific antibody was detected by the addition of a mouse anti-human IgG monoclonal antibody (McAb), which was itself revealed by iodinated sheep IgG antimouse F(ab). The authors have shown that this technique is suitable for the estimation of IgG anti-poliovirus antibodies induced in children following polio vaccine. The present study shows that SPRIA provides a simple and inexpensive method for serological studies with poliovirus particularly for use in large-scale surveys.

  19. Cetuximab in combination with anti-human IgG antibodies efficiently down-regulates the EGF receptor by macropinocytosis

    International Nuclear Information System (INIS)

    Berger, Christian; Madshus, Inger Helene; Stang, Espen

    2012-01-01

    The monoclonal antibody C225 (Cetuximab) blocks binding of ligand to the epidermal growth factor receptor (EGFR). In addition, it is known that incubation with C225 induces endocytosis of the EGFR. This endocytosis has previously been shown to be increased when C225 is combined with an additional monoclonal anti-EGFR antibody. However, the effects of antibody combinations on EGFR activation, endocytosis, trafficking and degradation have been unclear. By binding a secondary antibody to the C225-EGFR complex, we here demonstrate that a combination of antibodies can efficiently internalize and degrade the EGFR. Although the combination of antibodies activated the EGFR kinase and induced ubiquitination of the EGFR, the kinase activity was not required for internalization of the EGFR. In contrast to EGF-induced EGFR down-regulation, the antibody combination efficiently degraded the EGFR without initiating downstream proliferative signaling. The antibody-induced internalization of EGFR was found not to depend on clathrin and/or dynamin, but depended on actin polymerization, suggesting induction of macropinocytosis. Macropinocytosis may cause internalization of large membrane areas, and this could explain the highly efficient internalization of the EGFR induced by combination of antibodies. -- Highlight: ► Cetuximab induced endocytosis of EGFR increases upon combination with anti-human IgG. ► Antibody combination causes internalization of EGFR by macropinocytosis. ► Antibody-induced internalization of EGFR is independent of EGFR kinase activity. ► Antibody combination may have a zipper effect and cross-link EGFRs on neighboring cells.

  20. Mitochondrial-dependent Autoimmunity in Membranous Nephropathy of IgG4-related Disease

    Science.gov (United States)

    Buelli, Simona; Perico, Luca; Galbusera, Miriam; Abbate, Mauro; Morigi, Marina; Novelli, Rubina; Gagliardini, Elena; Tentori, Chiara; Rottoli, Daniela; Sabadini, Ettore; Saito, Takao; Kawano, Mitsuhiro; Saeki, Takako; Zoja, Carlamaria; Remuzzi, Giuseppe; Benigni, Ariela

    2015-01-01

    The pathophysiology of glomerular lesions of membranous nephropathy (MN), including seldom-reported IgG4-related disease, is still elusive. Unlike in idiopathic MN where IgG4 prevails, in this patient IgG3 was predominant in glomerular deposits in the absence of circulating anti-phospholipase A2 receptor antibodies, suggesting a distinct pathologic process. Here we documented that IgG4 retrieved from the serum of our propositus reacted against carbonic anhydrase II (CAII) at the podocyte surface. In patient's biopsy, glomerular CAII staining increased and co-localized with subepithelial IgG4 deposits along the capillary walls. Patient's IgG4 caused a drop in cell pH followed by mitochondrial dysfunction, excessive ROS production and cytoskeletal reorganization in cultured podocytes. These events promoted mitochondrial superoxide-dismutase-2 (SOD2) externalization on the plasma membrane, becoming recognizable by complement-binding IgG3 anti-SOD2. Among patients with IgG4-related disease only sera of those with IgG4 anti-CAII antibodies caused low intracellular pH and mitochondrial alterations underlying SOD2 externalization. Circulating IgG4 anti-CAII can cause podocyte injury through processes of intracellular acidification, mitochondrial oxidative stress and neoantigen induction in patients with IgG4 related disease. The onset of MN in a subset of patients could be due to IgG4 antibodies recognizing CAII with consequent exposure of mitochondrial neoantigen in the context of multifactorial pathogenesis of disease. PMID:26137589

  1. Genetic and infectious profiles influence cerebrospinal fluid IgG abnormality in Japanese multiple sclerosis patients.

    Directory of Open Access Journals (Sweden)

    Satoshi Yoshimura

    Full Text Available BACKGROUND: Abnormal intrathecal synthesis of IgG, reflected by cerebrospinal fluid (CSF oligoclonal IgG bands (OBs and increased IgG index, is much less frequently observed in Japanese multiple sclerosis (MS cohorts compared with Western cohorts. We aimed to clarify whether genetic and common infectious backgrounds influence CSF IgG abnormality in Japanese MS patients. METHODOLOGY: We analyzed HLA-DRB1 alleles, and IgG antibodies against Chlamydia pneumoniae, Helicobacter pylori, Epstein-Barr virus nuclear antigen (EBNA, and varicella zoster virus (VZV in 94 patients with MS and 367 unrelated healthy controls (HCs. We defined CSF IgG abnormality as the presence of CSF OBs and/or increased IgG index (>0.658. PRINCIPAL FINDINGS: CSF IgG abnormality was found in 59 of 94 (62.8% MS patients. CSF IgG abnormality-positive patients had a significantly higher frequency of brain MRI lesions meeting the Barkhof criteria compared with abnormality-negative patients. Compared with HCs, CSF IgG abnormality-positive MS patients showed a significantly higher frequency of DRB1 1501, whereas CSF IgG abnormality-negative patients had a significantly higher frequency of DRB1 0405. CSF IgG abnormality-positive MS patients had a significantly higher frequency of anti-C. pneumoniae IgG antibodies compared with CSF IgG abnormality-negative MS patients, although there was no difference in the frequency of anti-C. pneumoniae IgG antibodies between HCs and total MS patients. Compared with HCs, anti-H. pylori IgG antibodies were detected significantly less frequently in the total MS patients, especially in CSF IgG abnormality-negative MS patients. The frequencies of antibodies against EBNA and VZV did not differ significantly among the groups. CONCLUSIONS: CSF IgG abnormality is associated with Western MS-like brain MRI features. DRB1 1501 and C. pneumoniae infection confer CSF IgG abnormality, while DRB1 0405 and H. pylori infection are positively and negatively

  2. Well-oriented ZZ–PS-tag with high Fc-binding onto polystyrene surface for controlled immobilization of capture antibodies

    International Nuclear Information System (INIS)

    Tang, Jin-Bao; Sun, Xi-Feng; Yang, Hong-Ming; Zhang, Bao-Gang; Li, Zhi-Jian; Lin, Zhi-Juan; Gao, Zhi-Qin

    2013-01-01

    Graphical abstract: -- Highlights: •A versatile platform for immobilizing functionally intact IgG is proposed. •The mechanism relies on properly oriented ZZ–PS-tag onto a hydrophilic PS surface. •The oriented ZZ–PS-tag presents ∼fivefold higher IgG-binding activity. •The platform shows tenfold higher sensitivity and a wider linear range in ELISA. -- Abstract: The site specificity and bioactivity retention of antibodies immobilized on a solid substrate are crucial requirements for solid phase immunoassays. A fusion protein between an immunoglobulin G (IgG)-binding protein (ZZ protein) and a polystyrene-binding peptide (PS-tag) was constructed, and then used to develop a simple method for the oriented immobilization of the ZZ protein onto a PS support by the specific attachment of the PS-tag onto a hydrophilic PS. The orientation of intact IgG was achieved via the interaction of the ZZ protein and the constant fragment (Fc), thereby displayed the Fab fragment for binding antigen. The interaction between rabbit IgG anti-horseradish peroxidase (anti-HRP) and its binding partner HRP was analyzed. Results showed that the oriented ZZ–PS-tag yielded an IgG-binding activity that is fivefold higher than that produced by the passive immobilization of the ZZ protein. The advantage of the proposed immunoassay strategy was demonstrated through an enzyme-linked immunosorbent assay, in which monoclonal mouse anti-goat IgG and HRP-conjugated rabbit F(ab′) 2 anti-goat IgG were used to detect goat IgG. The ZZ–PS-tag presented a tenfold higher sensitivity and a wider linear range than did the passively immobilized ZZ protein. The proposed approach may be an attractive strategy for a broad range of applications involving the oriented immobilization of intact IgGs onto PS supports, in which only one type of phi-PS (ZZ–PS-tag) surface is used

  3. Well-oriented ZZ–PS-tag with high Fc-binding onto polystyrene surface for controlled immobilization of capture antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jin-Bao, E-mail: tangjinbao@yahoo.com.cn [School of Pharmacy and Biology, Weifang Medical University, Weifang 261053 (China); Sun, Xi-Feng [Clinical Laboratory, Weifang People' s Hospital, Weifang 261041 (China); Yang, Hong-Ming [School of Pharmacy and Biology, Weifang Medical University, Weifang 261053 (China); Zhang, Bao-Gang [School of Basic Medicine, Weifang Medical University, Weifang 261053 (China); Li, Zhi-Jian [School of Pharmacy and Biology, Weifang Medical University, Weifang 261053 (China); Lin, Zhi-Juan [School of Basic Medicine, Weifang Medical University, Weifang 261053 (China); Gao, Zhi-Qin, E-mail: zhiqingao@yahoo.cn [School of Pharmacy and Biology, Weifang Medical University, Weifang 261053 (China)

    2013-05-07

    Graphical abstract: -- Highlights: •A versatile platform for immobilizing functionally intact IgG is proposed. •The mechanism relies on properly oriented ZZ–PS-tag onto a hydrophilic PS surface. •The oriented ZZ–PS-tag presents ∼fivefold higher IgG-binding activity. •The platform shows tenfold higher sensitivity and a wider linear range in ELISA. -- Abstract: The site specificity and bioactivity retention of antibodies immobilized on a solid substrate are crucial requirements for solid phase immunoassays. A fusion protein between an immunoglobulin G (IgG)-binding protein (ZZ protein) and a polystyrene-binding peptide (PS-tag) was constructed, and then used to develop a simple method for the oriented immobilization of the ZZ protein onto a PS support by the specific attachment of the PS-tag onto a hydrophilic PS. The orientation of intact IgG was achieved via the interaction of the ZZ protein and the constant fragment (Fc), thereby displayed the Fab fragment for binding antigen. The interaction between rabbit IgG anti-horseradish peroxidase (anti-HRP) and its binding partner HRP was analyzed. Results showed that the oriented ZZ–PS-tag yielded an IgG-binding activity that is fivefold higher than that produced by the passive immobilization of the ZZ protein. The advantage of the proposed immunoassay strategy was demonstrated through an enzyme-linked immunosorbent assay, in which monoclonal mouse anti-goat IgG and HRP-conjugated rabbit F(ab′){sub 2} anti-goat IgG were used to detect goat IgG. The ZZ–PS-tag presented a tenfold higher sensitivity and a wider linear range than did the passively immobilized ZZ protein. The proposed approach may be an attractive strategy for a broad range of applications involving the oriented immobilization of intact IgGs onto PS supports, in which only one type of phi-PS (ZZ–PS-tag) surface is used.

  4. Characteristics of enzyme-linked immunosorbent assay for detection of IgG antibodies specific to Сhlamydia trachomatis heat shock protein (HSP-60

    Directory of Open Access Journals (Sweden)

    O. Yu. Galkin

    2017-02-01

    Full Text Available The goal of this work was to study sensitivity and specificity of the developed ELISA set for the identification of IgG antibodies against Chlamydia trachomatis HSP-60 (using biotinylated tyramine-based signal amplification system. The study was conducted using a panel of characterized sera, as well as two reference ELISA sets of similar purpose. According to the results of ELISA informative value parameters, the ELISA we have developed showed the highest specificity and sensitivity parameters (no false negative or false positive results were registered. In 4 out of 15 intralaboratory panel serum samples initially identified as negative, anti-HSP-60 IgG-antibodies test result in reference ELISA sets upon dilution changed from negative to positive. The nature of titration curves of false negative sera and commercial monoclonal antibodies А57-В9 against C. trachomatis HSP-60 after incubation for 24 h was indicative of the presence of anti-idiotypic antibodies in these samples. Upon sera dilution, idiotypic-anti-idiotypic complexes dissociated, which caused the change of test result. High informative value of the developed ELISA set for identification of IgG antibodies against C. trachomatis HSP-60 has been proven. Anti-idiotypic antibodies possessing C. trachomatis anti-HSP-60 activity and being one of the causes of false negative results of the relevant ELISA-based tests have been identified in blood sera of individuals infected with chlamydial genitourinary infection agents.

  5. Blood-brain barrier drug delivery of IgG fusion proteins with a transferrin receptor monoclonal antibody.

    Science.gov (United States)

    Pardridge, William M

    2015-02-01

    Biologic drugs are large molecules that do not cross the blood- brain barrier (BBB). Brain penetration is possible following the re-engineering of the biologic drug as an IgG fusion protein. The IgG domain is a MAb against an endogenous BBB receptor such as the transferrin receptor (TfR). The TfRMAb acts as a molecular Trojan horse to ferry the fused biologic drug into the brain via receptor-mediated transport on the endogenous BBB TfR. This review discusses TfR isoforms, models of BBB transport of transferrin and TfRMAbs, and the genetic engineering of TfRMAb fusion proteins, including BBB penetrating IgG-neurotrophins, IgG-decoy receptors, IgG-lysosomal enzyme therapeutics and IgG-avidin fusion proteins, as well as BBB transport of bispecific antibodies formed by fusion of a therapeutic antibody to a TfRMAb targeting antibody. Also discussed are quantitative aspects of the plasma pharmacokinetics and brain uptake of TfRMAb fusion proteins, as compared to the brain uptake of small molecules, and therapeutic applications of TfRMAb fusion proteins in mouse models of neural disease, including Parkinson's disease, stroke, Alzheimer's disease and lysosomal storage disorders. The review covers the engineering of TfRMAb-avidin fusion proteins for BBB targeted delivery of biotinylated peptide radiopharmaceuticals, low-affinity TfRMAb Trojan horses and the safety pharmacology of chronic administration of TfRMAb fusion proteins. The BBB delivery of biologic drugs is possible following re-engineering as a fusion protein with a molecular Trojan horse such as a TfRMAb. The efficacy of this technology will be determined by the outcome of future clinical trials.

  6. STUDY ON SEROPREVALENCE OF MUMPS - SPECIFIC IgG ANTIBODIES IN A HEALTHY POPULATION

    Directory of Open Access Journals (Sweden)

    Milena Karcheva

    2010-09-01

    Full Text Available Mumps is a vaccine preventable viral infection. Its typical clinical manifestations are characterized by pain and swelling of the salivary glands, fever, and fatigue. Often other organs are affected - testes in males after puberty (orchitis, ovaries in women (ooforitis, pancreas (pancreatitis, central nervous system (meningities. The use of specific immune prophylaxis led to a significant success in the fight against mumps, but there are still unresolved issues related to the immunological and epidemiological effectiveness of the vaccines. The disease continues to interest researchers today. The main issues being tackled are related to the conduct of virological, clinical and sero-epidemiological studies in different countries. Objectives of the study is to determine the frequency distribution of mumps-specific IgG antibodies in healthy populations in the region of Pleven, Bulgaria. Methods: a cross-sectional sero - epidemiological representative population - based survey in the area was made. Enzyme immunoassay method was used for an indirect proof of mumps - specific IgG serum antibodies. 410 people were examined at an average age of 25 (1 to 84. Of these, 250 (61 % were women and 160 (39 % - men. Results: Of all test results, the negative were 72 (19 %, the borderline were 12 (3 %, the positive were 182 (44 %, and highly positive were 144 (35 %. The vaccination status showed that 242 (69 % of all surveyed were immunized with a vaccine against mumps. According to the immunization schedule in Bulgaria, 132 (33 % people were immunized with monovaccine during the years - 1 intake, 80 (20 % with trivaccine - 1 intake, and 64 (16 % - 2 doses. Conclusion: We believe that despite the specific immunprophylaxis carried out against mumps decades on end, the necessary level of protection leading to its elimination has not yet been reached.

  7. Monitoring the systemic human memory B cell compartment of melanoma patients for anti-tumor IgG antibodies.

    Directory of Open Access Journals (Sweden)

    Amy E Gilbert

    Full Text Available Melanoma, a potentially lethal skin cancer, is widely thought to be immunogenic in nature. While there has been much focus on T cell-mediated immune responses, limited knowledge exists on the role of mature B cells. We describe an approach, including a cell-based ELISA, to evaluate mature IgG antibody responses to melanoma from human peripheral blood B cells. We observed a significant increase in antibody responses from melanoma patients (n = 10 to primary and metastatic melanoma cells compared to healthy volunteers (n = 10 (P<0.0001. Interestingly, we detected a significant reduction in antibody responses to melanoma with advancing disease stage in our patient cohort (n = 21 (P<0.0001. Overall, 28% of melanoma patient-derived B cell cultures (n = 1,800 compared to 2% of cultures from healthy controls (n = 600 produced antibodies that recognized melanoma cells. Lastly, a patient-derived melanoma-specific monoclonal antibody was selected for further study. This antibody effectively killed melanoma cells in vitro via antibody-mediated cellular cytotoxicity. These data demonstrate the presence of a mature systemic B cell response in melanoma patients, which is reduced with disease progression, adding to previous reports of tumor-reactive antibodies in patient sera, and suggesting the merit of future work to elucidate the clinical relevance of activating humoral immune responses to cancer.

  8. Monitoring the Systemic Human Memory B Cell Compartment of Melanoma Patients for Anti-Tumor IgG Antibodies

    Science.gov (United States)

    Gilbert, Amy E.; Karagiannis, Panagiotis; Dodev, Tihomir; Koers, Alexander; Lacy, Katie; Josephs, Debra H.; Takhar, Pooja; Geh, Jenny L. C.; Healy, Ciaran; Harries, Mark; Acland, Katharine M.; Rudman, Sarah M.; Beavil, Rebecca L.; Blower, Philip J.; Beavil, Andrew J.; Gould, Hannah J.; Spicer, James; Nestle, Frank O.; Karagiannis, Sophia N.

    2011-01-01

    Melanoma, a potentially lethal skin cancer, is widely thought to be immunogenic in nature. While there has been much focus on T cell-mediated immune responses, limited knowledge exists on the role of mature B cells. We describe an approach, including a cell-based ELISA, to evaluate mature IgG antibody responses to melanoma from human peripheral blood B cells. We observed a significant increase in antibody responses from melanoma patients (n = 10) to primary and metastatic melanoma cells compared to healthy volunteers (n = 10) (P<0.0001). Interestingly, we detected a significant reduction in antibody responses to melanoma with advancing disease stage in our patient cohort (n = 21) (P<0.0001). Overall, 28% of melanoma patient-derived B cell cultures (n = 1,800) compared to 2% of cultures from healthy controls (n = 600) produced antibodies that recognized melanoma cells. Lastly, a patient-derived melanoma-specific monoclonal antibody was selected for further study. This antibody effectively killed melanoma cells in vitro via antibody-mediated cellular cytotoxicity. These data demonstrate the presence of a mature systemic B cell response in melanoma patients, which is reduced with disease progression, adding to previous reports of tumor-reactive antibodies in patient sera, and suggesting the merit of future work to elucidate the clinical relevance of activating humoral immune responses to cancer. PMID:21559411

  9. Cetuximab in combination with anti-human IgG antibodies efficiently down-regulates the EGF receptor by macropinocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Christian [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Madshus, Inger Helene [Institute of Pathology, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Stang, Espen, E-mail: espsta@rr-research.no [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway)

    2012-12-10

    The monoclonal antibody C225 (Cetuximab) blocks binding of ligand to the epidermal growth factor receptor (EGFR). In addition, it is known that incubation with C225 induces endocytosis of the EGFR. This endocytosis has previously been shown to be increased when C225 is combined with an additional monoclonal anti-EGFR antibody. However, the effects of antibody combinations on EGFR activation, endocytosis, trafficking and degradation have been unclear. By binding a secondary antibody to the C225-EGFR complex, we here demonstrate that a combination of antibodies can efficiently internalize and degrade the EGFR. Although the combination of antibodies activated the EGFR kinase and induced ubiquitination of the EGFR, the kinase activity was not required for internalization of the EGFR. In contrast to EGF-induced EGFR down-regulation, the antibody combination efficiently degraded the EGFR without initiating downstream proliferative signaling. The antibody-induced internalization of EGFR was found not to depend on clathrin and/or dynamin, but depended on actin polymerization, suggesting induction of macropinocytosis. Macropinocytosis may cause internalization of large membrane areas, and this could explain the highly efficient internalization of the EGFR induced by combination of antibodies. -- Highlight: Black-Right-Pointing-Pointer Cetuximab induced endocytosis of EGFR increases upon combination with anti-human IgG. Black-Right-Pointing-Pointer Antibody combination causes internalization of EGFR by macropinocytosis. Black-Right-Pointing-Pointer Antibody-induced internalization of EGFR is independent of EGFR kinase activity. Black-Right-Pointing-Pointer Antibody combination may have a zipper effect and cross-link EGFRs on neighboring cells.

  10. Functional characterization of the high affinity IgG Receptor : making heads and tails of FcγRI

    NARCIS (Netherlands)

    van der Poel, C.E.

    2011-01-01

    This thesis focuses on human FcγRI, a high affinity receptor for antibodies of the IgG isotype. IgG is the most abundant antibody type in blood and all currently FDA approved therapeutic antibodies are of the IgG isotype. FcγRI, a member of the activating Fcγ receptors, exists as a complex of a

  11. A rare case of Addison's disease, hepatitis, thyreoiditis, positive IgG anti-tissue transglutaminase antibodies and partial IgA deficiency.

    Science.gov (United States)

    Baleva, Marta P; Mihaylova, Snejina; Yankova, Petja; Atanasova, Iliana; Nikolova-Vlahova, Milena; Naumova, Elissaveta

    2016-01-01

    Selective IgA deficiency (IgAD) is the most prevalent type of primary immune deficiencies, but partial IgA deficiency is even more common. Addison's disease is a rare condition associated with primary adrenal insufficiency due to infection or autoimmune destruction of the adrenals. The association between IgA deficiency and Addison's disease is very rare. We observed a 22-year-old male patient with marked darkening of the skin, especially on the palms and areolae, jaundice on the skin and sclera, astheno-adynamia, hypotension (80/50 mm Hg), and pain in the right hypochondrium. The laboratory investigations revealed increased serum levels of total and indirect bilirubin, AST, ALT, GGT and LDH, negative HBsAg, anti-HBc IgM, anti-HCV and anti-HAV IgM, very low serum IgA levels (0.16 g/l) with normal IgG and IgM, negative ANA, ANCA, AMA, LKM-1, anti-GAD-60, anti-IA-2, anti-thyroglobulin antibodies, a mild increase in anti-TPO antibodies titer, a marked increase in IgG anti-tissue transglutaminase antibodies, with no typical changes in cellular immunity, negative T-SPOT-TB test, HLA - A*01; B*08; DRB1*03; DQB1*02, karyotype - 46, XY. We present a rare case of partial IgA deficiency with Addison's disease, hepatitis, thyroiditis and positive anti-tissue transglutaminase antibodies. IgAD and some autoimmune disorders share several predisposing HLA genes, thus explaining the increased prevalence of IgAD in certain patient groups.

  12. Total lymphoid irradiation reduces IgG autoantibody production and enhances specific antibody responses in NZB/NZW F1 mice

    Energy Technology Data Exchange (ETDEWEB)

    Farinas, M.C.; Strober, S.

    1989-07-01

    Thymus-independent primary antibody responses were studied in young and old (9 months) untreated and TLI-treated NZB/NZW and BALB/c mice. Untreated old NZB/NZW mice had a low primary response to Brucella abortus (BA) as compared to that of young NZB/NZW and BALB/c mice. However, TLI treatment resulted in a 130-fold increase in the IgG anti-BA primary antibody response at day 21 postimmunization, achieving similar levels to those of young NZB/NZW or nonautoimmune BALB/c mice. Anti-TNP responses to trinitrophenylated BA or Ficoll were masked by high background levels of anti-TNP antibodies. Despite the increase in the anti-BA response, spontaneous immunoglobulin secretion and autoantibody levels were markedly decreased after TLI in old NZB/NZW mice.

  13. Total lymphoid irradiation reduces IgG autoantibody production and enhances specific antibody responses in NZB/NZW F1 mice

    International Nuclear Information System (INIS)

    Farinas, M.C.; Strober, S.

    1989-01-01

    Thymus-independent primary antibody responses were studied in young and old (9 months) untreated and TLI-treated NZB/NZW and BALB/c mice. Untreated old NZB/NZW mice had a low primary response to Brucella abortus (BA) as compared to that of young NZB/NZW and BALB/c mice. However, TLI treatment resulted in a 130-fold increase in the IgG anti-BA primary antibody response at day 21 postimmunization, achieving similar levels to those of young NZB/NZW or nonautoimmune BALB/c mice. Anti-TNP responses to trinitrophenylated BA or Ficoll were masked by high background levels of anti-TNP antibodies. Despite the increase in the anti-BA response, spontaneous immunoglobulin secretion and autoantibody levels were markedly decreased after TLI in old NZB/NZW mice

  14. Incorporation of FcRn-mediated disposition model to describe the population pharmacokinetics of therapeutic monoclonal IgG antibody in clinical patients.

    Science.gov (United States)

    Ng, Chee M

    2016-03-01

    The two-compartment linear model used to describe the population pharmacokinetics (PK) of many therapeutic monoclonal antibodies (TMAbs) offered little biological insight to antibody disposition in humans. The purpose of this study is to develop a semi-mechanistic FcRn-mediated IgG disposition model to describe the population PK of TMAbs in clinical patients. A standard two-compartment linear PK model from a previously published population PK model of pertuzumab was used to simulate intensive PK data of 100 subjects for model development. Two different semi-mechanistic FcRn-mediated IgG disposition models were developed and First Order Conditional Estimation (FOCE) with the interaction method in NONMEM was used to obtain the final model estimates. The performances of these models were then compared with the two-compartment linear PK model used to simulate the data for model development. A semi-mechanistic FcRn-mediated IgG disposition model consisting of a peripheral tissue compartment and FcRn-containing endosomes in the central compartment best describes the simulated pertuzumab population PK data. This developed semi-mechanistic population PK model had the same number of model parameters, produced very similar concentration-time profiles but provided additional biological insight to the FcRn-mediated IgG disposition in human subjects compared with the standard linear two-compartment linear PK model. This first reported semi-mechanistic model may serve as an important model framework for developing future population PK models of TMAbs in clinical patients. Copyright © 2015 John Wiley & Sons, Ltd.

  15. NOG-hIL-4-Tg, a new humanized mouse model for producing tumor antigen-specific IgG antibody by peptide vaccination.

    Directory of Open Access Journals (Sweden)

    Yoshie Kametani

    Full Text Available Immunodeficient mice transplanted with human peripheral blood mononuclear cells (PBMCs are promising tools to evaluate human immune responses to vaccines. However, these mice usually develop severe graft-versus-host disease (GVHD, which makes estimation of antigen-specific IgG production after antigen immunization difficult. To evaluate antigen-specific IgG responses in PBMC-transplanted immunodeficient mice, we developed a novel NOD/Shi-scid-IL2rγnull (NOG mouse strain that systemically expresses the human IL-4 gene (NOG-hIL-4-Tg. After human PBMC transplantation, GVHD symptoms were significantly suppressed in NOG-hIL-4-Tg compared to conventional NOG mice. In kinetic analyses of human leukocytes, long-term engraftment of human T cells has been observed in peripheral blood of NOG-hIL-4-Tg, followed by dominant CD4+ T rather than CD8+ T cell proliferation. Furthermore, these CD4+ T cells shifted to type 2 helper (Th2 cells, resulting in long-term suppression of GVHD. Most of the human B cells detected in the transplanted mice had a plasmablast phenotype. Vaccination with HER2 multiple antigen peptide (CH401MAP or keyhole limpet hemocyanin (KLH successfully induced antigen-specific IgG production in PBMC-transplanted NOG-hIL-4-Tg. The HLA haplotype of donor PBMCs might not be relevant to the antibody secretion ability after immunization. These results suggest that the human PBMC-transplanted NOG-hIL-4-Tg mouse is an effective tool to evaluate the production of antigen-specific IgG antibodies.

  16. Hinge-deleted IgG4 blocker therapy for acetylcholine receptor myasthenia gravis in rhesus monkeys.

    Science.gov (United States)

    Losen, Mario; Labrijn, Aran F; van Kranen-Mastenbroek, Vivianne H; Janmaat, Maarten L; Haanstra, Krista G; Beurskens, Frank J; Vink, Tom; Jonker, Margreet; 't Hart, Bert A; Mané-Damas, Marina; Molenaar, Peter C; Martinez-Martinez, Pilar; van der Esch, Eline; Schuurman, Janine; de Baets, Marc H; Parren, Paul W H I

    2017-04-20

    Autoantibodies against ion channels are the cause of numerous neurologic autoimmune disorders. Frequently, such pathogenic autoantibodies have a restricted epitope-specificity. In such cases, competing antibody formats devoid of pathogenic effector functions (blocker antibodies) have the potential to treat disease by displacing autoantibodies from their target. Here, we have used a model of the neuromuscular autoimmune disease myasthenia gravis in rhesus monkeys (Macaca mulatta) to test the therapeutic potential of a new blocker antibody: MG was induced by passive transfer of pathogenic acetylcholine receptor-specific monoclonal antibody IgG1-637. The effect of the blocker antibody (IgG4Δhinge-637, the hinge-deleted IgG4 version of IgG1-637) was assessed using decrement measurements and single-fiber electromyography. Three daily doses of 1.7 mg/kg IgG1-637 (cumulative dose 5 mg/kg) induced impairment of neuromuscular transmission, as demonstrated by significantly increased jitter, synaptic transmission failures (blockings) and a decrease in the amplitude of the compound muscle action potentials during repeated stimulations (decrement), without showing overt symptoms of muscle weakness. Treatment with three daily doses of 10 mg/kg IgG4Δhinge-637 significantly reduced the IgG1-637-induced increase in jitter, blockings and decrement. Together, these results represent proof-of principle data for therapy of acetylcholine receptor-myasthenia gravis with a monovalent antibody format that blocks binding of pathogenic autoantibodies.

  17. Performance of two Aspergillus IgG EIA assays compared with the precipitin test in chronic and allergic aspergillosis.

    Science.gov (United States)

    Baxter, C G; Denning, D W; Jones, A M; Todd, A; Moore, C B; Richardson, M D

    2013-04-01

    Detection of Aspergillus IgG antibodies is important in the diagnosis of chronic pulmonary aspergillosis and allergic bronchopulmonary aspergillosis. Immunoprecipitation techniques to detect these antibodies appear to lack sensitivity and accurate quantitation compared with enzyme immunoassays (EIA). This study assessed the performance of two commercial EIAs compared with counterimmunoelectrophoresis (CIE). This was a prospective cohort study of 175 adult patients with chronic or allergic pulmonary aspergillosis. Aspergillus IgG antibodies were detected using CIE, Phadia ImmunoCap Aspergillus IgG and Bio-Rad Platelia Aspergillus IgG. Inter-assay reproducibility was determined for each method and 25 patients had two serum samples analysed within a 6-month interval. When compared with CIE, both ImmunoCap and Platelia Aspergillus IgG had good sensitivity (97 and 93%, respectively) for detection of Aspergillus IgG antibodies. The level of agreement between the two EIAs for positive results was good, but the concentration of antibodies was not correlated between the tests or with CIE titre. ImmunoCap IgG inter-assay coefficient of variation was 5%, whereas Platelia IgG was 33%. Median ImmunoCap IgG values for CPA and allergic aspergillosis were 95 and 32 mg/L, respectively, whereas Platelia IgG values were >80 and 6 AU/mL. The direction of CIE titre change over 6 months was mirrored by ImmunoCap IgG levels in 92% of patients, and by Platelia IgG in 72% of patients. Both ImmunoCap and Platelia Aspergillus IgG EIAs are sensitive measures of Aspergillus IgG antibodies compared with CIE. However, ImmunoCap appears to have better reproducibility and may be more suitable for monitoring patient disease. © 2012 The Authors Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  18. An Enhanced Pre- and Postnatal Development Study in Cynomolgus Monkeys with Tabalumab: A Human IgG4 Monoclonal Antibody.

    Science.gov (United States)

    Breslin, William J; Hilbish, Kim G; Martin, Jennifer A; Halstead, Carolyn A; Newcomb, Deanna L; Chellman, Gary J

    2015-06-01

    Tabalumab, a human IgG4 monoclonal antibody (mAb) with neutralizing activity against both soluble and membrane B-cell activating factor (BAFF), has been under development for the treatment of autoimmune diseases. The purpose of this study was to determine the potential adverse effects of maternal tabalumab exposure on pregnancy, parturition, and lactation of the mothers and on the growth, viability, and development of the offspring through postnatal day (PND) 204. Tabalumab was administered by subcutaneous injection to presumed pregnant cynomolgus monkeys (16-19 per group) every 2 weeks from gestation day (GD) 20 to 22 until parturition at doses of 0, 0.3, or 30 mg/kg. Evaluations in mothers and infants included clinical signs, body weight, toxicokinetics, blood lymphocyte phenotyping, T-cell-dependent antibody response (infants only), antitherapeutic antibody (ATA), organ weights (infants only), and gross and microscopic histopathology. Infants were also examined for external and visceral morphologic and neurobehavioral development. There were no adverse tabalumab-related effects on maternal or infant endpoints. An expected pharmacological decrease in peripheral blood B-lymphocytes occurred in adults and infants; however, B-cell recovery was evident by PND154 in adults and infants at 0.3 mg/kg and by PND204 in infants at 30 mg/kg. At 30 mg/kg, a reduced IgM antibody response to T-cell-dependent antigen keyhole limpet hemocyanin (KLH) was observed following primary immunization. Following secondary KLH immunization, all infants in both dose groups mounted anti-KLH IgM and IgG antibody responses similar to control. Placental and mammary transfer of tabalumab was demonstrated. In conclusion, the no-observed-adverse-effect level for maternal and developmental toxicity was 30 mg/kg, the highest dose tested. Exposures at 30 mg/kg provide a margin of safety of 16× the anticipated clinical exposure. © 2015 Wiley Periodicals, Inc.

  19. Assessing drivers of the IgG4 antibody reactivity to recombinant antigen Bm14 in Wuchereria bancrofti endemic populations in East Africa

    DEFF Research Database (Denmark)

    Hansen, Johanne Damgaard; Meyrowitsch, Dan W.; Rwegoshora, Rwehumbiza T.

    2016-01-01

    to the recombinant filarial antigen Bm14 in Wuchereria bancrofti endemic populations in East Africa. Sera collected during previous studies from 395 well characterized individuals with regard to age, sex, mf, CFA, household vector biting and household exposure to infective filarial larvae were tested for IgG4......A high proportion of the human population in lymphatic filariasis (LF) endemic areas is positive for filarial specific IgG4 antibodies, including many individuals without microfilariae (mf; circulating larvae in the human blood) or circulating filarial antigens (CFA; marker of adult worm infection...

  20. Induction of IgG3 to LPS via Toll-like receptor 4 co-stimulation.

    Directory of Open Access Journals (Sweden)

    Francisco J Quintana

    Full Text Available B-cells integrate antigen-specific signals transduced via the B-cell receptor (BCR and antigen non-specific co-stimulatory signals provided by cytokines and CD40 ligation in order to produce IgG antibodies. Toll-like receptors (TLRs also provide co-stimulation, but the requirement for TLRs to generate T-cell independent and T-cell dependent antigen specific antibody responses is debated. Little is known about the role of B-cell expressed TLRs in inducing antigen-specific antibodies to antigens that also activate TLR signaling. We found that mice lacking functional TLR4 or its adaptor molecule MyD88 harbored significantly less IgG3 natural antibodies to LPS, and required higher amounts of LPS to induce anti-LPS IgG3. In vitro, BCR and TLR4 signaling synergized, lowering the threshold for production of T-cell independent IgG3 and IL-10. Moreover, BCR and TLR4 directly associate through the transmembrane domain of TLR4. Thus, in vivo, BCR/TLR synergism could facilitate the induction of IgG3 antibodies against microbial antigens that engage both innate and adaptive B-cell receptors. Vaccines might exploit BCR/TLR synergism to rapidly induce antigen-specific antibodies before significant T-cell responses arise.

  1. Complete assignment of the methionyl carbonyl carbon resonance in switch variant anti-dansyl antibodies labeled with [1-13C]methionine

    International Nuclear Information System (INIS)

    Kato, Koichi; Matsunaga, C.; Igarashi, Takako; Kim, Hahyung; Odaka, Asano; Shimada, Ichio; Arata, Yoji

    1991-01-01

    A 13 C NMR study is reported of switch variant anti-dansyl antibodies developed by Dangl et al. who had used the fluorescence-activated cell sorter to select and clone these variants. These switch variant antibodies possess the identical V H , V L , and C L domains in conjunction with different heavy chain constant regions. In the present study, switch variant antibodies of IgG1, IgG2a, and IgG2b subclasses were used along with a short-chain IgG2a antibody, in which the entire C H 1 domain is deleted. The switch variant antibodies were specifically labeled with [1- 13 C]methionine by growing hybridoma cells in serum-free medium. Assignments of all the methionyl carbonyl carbon resonances have been completed by using the intact antibodies along with their fragments and recombined proteins in which either heavy or light chain is labeled. A double labeling method has played a crucial role in the process of the spectral assignments. The strategy used for the assignments has been described in detail. In incorporating 15 N-labeled amino acids into the antibodies for the double labeling, isotope dilution caused a serious problem except in the cases of [α- 15 N]lysine and [ 15 N]threonine, both of which cannot become the substrate of transaminases. It was found that β-chloro-L-alanine is most effective in suppressing the isotope scrambling. So far, spectral assignments by the double labeling method have been possible with 15 N-labeled Ala, His, Ile, Lys, Met, Ser, Thr, Tyr, and Val. On the basis of the results of the present 13 C study, possible use of the assigned carbonyl carbon resonances for the elucidation of the structure-function relationship in the antibody system has been briefly discussed

  2. Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.; Suzuki, M.; Adachi, S.

    1983-01-01

    Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization at low temperatures was studied. The antibody activity of antibody was not affected by irradiation at an irradiation dose of below 8 MR and low temperatures. Immobilization of peroxidase-labeled anti-rabbit IgG goat IgG, anti-peroxidase, peroxidase, and anti-alpha-fetoprotein was carried out with hydrophilic and hydrophobic monomers. The activity of the immobilized enzyme-labeled antibody membranes varied with the thickness of the membranes and increased with decreasing membrane thickness. The activity of the immobilized antibody particles was varied by particle size. Immobilized anti-alpha-fetoprotein particles and membranes can be used for the assay of alpha-fetoprotein by the antigen-antibody reaction, such as a solid-phase sandwich method with high sensitivity

  3. Comparison of enzyme-linked immunosorbent assay, radioimmunoassay, complement fixation, anticomplement immunofluorescence and passive haemaglutination techniques for detecting cytomegalovirus IgG antibody

    Energy Technology Data Exchange (ETDEWEB)

    Booth, J C; Hannington, G; Bakir, T M.F.; Stern, H; Kangro, H; Griffiths, P D; Heath, R B [Saint George' s Hospital Medical School, London (UK); Saint Bartholomew' s Hospital, London (UK))

    1982-12-01

    The radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques were found to be comparable in sensitivity and specificity for detecting cytomegalovirus IgG antibody, and 10 to 100 times more sensitive than complement-fixation (CF), anticomplement immunofluorescence (ACIF) and passive haemagglutination (PHA). In screening tests for antibody, the frequency of false-positive and -negative results was 0.6% for RIA and ELISA, 1.5% for CF, 1.6% for ACIF and 3.6% for PHA. PHA was the least satisfactory test, largely because of technical problems.

  4. Complete assignment of the methionyl carbonyl carbon resonance in switch variant anti-dansyl antibodies labeled with (1- sup 13 C)methionine

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Koichi; Matsunaga, C.; Igarashi, Takako; Kim, Hahyung; Odaka, Asano; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo, Hongo (Japan))

    1991-01-01

    A {sup 13}C NMR study is reported of switch variant anti-dansyl antibodies developed by Dangl et al. who had used the fluorescence-activated cell sorter to select and clone these variants. These switch variant antibodies possess the identical V{sub H}, V{sub L}, and C{sub L} domains in conjunction with different heavy chain constant regions. In the present study, switch variant antibodies of IgG1, IgG2a, and IgG2b subclasses were used along with a short-chain IgG2a antibody, in which the entire C{sub H}1 domain is deleted. The switch variant antibodies were specifically labeled with (1-{sup 13}C)methionine by growing hybridoma cells in serum-free medium. Assignments of all the methionyl carbonyl carbon resonances have been completed by using the intact antibodies along with their fragments and recombined proteins in which either heavy or light chain is labeled. A double labeling method has played a crucial role in the process of the spectral assignments. The strategy used for the assignments has been described in detail. In incorporating {sup 15}N-labeled amino acids into the antibodies for the double labeling, isotope dilution caused a serious problem except in the cases of ({alpha}-{sup 15}N)lysine and ({sup 15}N)threonine, both of which cannot become the substrate of transaminases. It was found that {beta}-chloro-L-alanine is most effective in suppressing the isotope scrambling. So far, spectral assignments by the double labeling method have been possible with {sup 15}N-labeled Ala, His, Ile, Lys, Met, Ser, Thr, Tyr, and Val. On the basis of the results of the present {sup 13}C study, possible use of the assigned carbonyl carbon resonances for the elucidation of the structure-function relationship in the antibody system has been briefly discussed.

  5. Viscosity of high concentration protein formulations of monoclonal antibodies of the IgG1 and IgG4 subclass - Prediction of viscosity through protein-protein interaction measurements

    DEFF Research Database (Denmark)

    Neergaard, Martin S; Kalonia, Devendra S; Parshad, Henrik

    2013-01-01

    The purpose of this work was to explore the relation between protein-protein interactions (PPIs) and solution viscosity at high protein concentration using three monoclonal antibodies (mAbs), two of the IgG4 subclass and one of the IgG1 subclass. A range of methods was used to quantify the PPI...... low or high protein concentration determined using DLS. The PPI measurements were correlated with solution viscosity (measured by DLS using polystyrene nanospheres and ultrasonic shear rheology) as a function of pH (4-9) and ionic strength (10, 50 and 150mM). Our measurements showed that the highest...... solution viscosity was observed under conditions with the most negative kD, the highest apparent radius and the lowest net charge. An increase in ionic strength resulted in a change in the nature of the PPI at low pH from repulsive to attractive. In the neutral to alkaline pH region the mAbs behaved...

  6. Sensitive and specific detection of Crimean-Congo Hemorrhagic Fever Virus (CCHFV)—Specific IgM and IgG antibodies in human sera using recombinant CCHFV nucleoprotein as antigen in μ-capture and IgG immune complex (IC) ELISA tests

    Science.gov (United States)

    Emmerich, Petra; Mika, Angela; von Possel, Ronald; Rackow, Anne; Liu, Yang; Schmitz, Herbert; Sherifi, Kurtesh; Halili, Barie; Jakupi, Xhevat; Berisha, Lindita; Ahmeti, Salih

    2018-01-01

    As the most widespread tick-borne arbovirus causing infections in numerous countries in Asia, Africa and Europe, Crimean-Congo Hemorrhagic Fever Virus (CCHFV, family Nairoviridae) was included in the WHO priority list of emerging pathogens needing urgent Research & Development attention. To ensure preparedness for potential future outbreak scenarios, reliable diagnostic tools for identification of acute cases as well as for performance of seroprevalence studies are necessary. Here, the CCHFV ortholog of the major bunyavirus antigen, the nucleoprotein (NP), was recombinantly expressed in E.coli, purified and directly labeled with horseradish peroxidase (HRP). Employing this antigen, two serological tests, a μ-capture ELISA for the detection of CCHFV-specific IgM antibodies (BLACKBOX CCHFV IgM) and an IgG immune complex (IC) ELISA for the detection of CCHFV-specific IgG antibodies (BLACKBOX CCHFV IgG), were developed. Test performance was evaluated and compared with both in-house gold standard testing by IgM/IgG indirect immunofluorescence (IIF) and commercially available ELISA tests (VectoCrimean-CHF-IgM/IgG, Vector-Best, Russia) using a serum panel comprising paired samples collected in Kosovo during the years 2013–2016 from 15 patients with an acute, RT-PCR-confirmed CCHFV infection, and 12 follow-up sera of the same patients collected approximately one year after having overcome the infection. Reliably detecting IgM antibodies in all acute phase sera collected later than day 4 after onset of symptoms, both IgM ELISAs displayed excellent diagnostic and analytical sensitivity (100%, 95% confidence interval (CI): 85.2%–100.0%). While both IgG ELISAs readily detected the high IgG titers present in convalescent patients approximately one year after having overcome the infection (sensitivity 100%, 95% CI: 73.5%–100.0%), the newly developed BLACKBOX CCHFV IgG ELISA was superior to the commercial IgG ELISA in detecting the rising IgG titers during the acute phase

  7. Generating and Purifying Fab Fragments from Human and Mouse IgG Using the Bacterial Enzymes IdeS, SpeB and Kgp.

    Science.gov (United States)

    Sjögren, Jonathan; Andersson, Linda; Mejàre, Malin; Olsson, Fredrik

    2017-01-01

    Fab fragments are valuable research tools in various areas of science including applications in imaging, binding studies, removal of Fc-mediated effector functions, mass spectrometry, infection biology, and many others. The enzymatic tools for the generation of Fab fragments have been discovered through basic research within the field of molecular bacterial pathogenesis. Today, these enzymes are widely applied as research tools and in this chapter, we describe methodologies based on bacterial enzymes to generate Fab fragments from both human and mouse IgG. For all human IgG subclasses, the IdeS enzyme from Streptococcus pyogenes has been applied to generate F(ab')2 fragments that subsequently can be reduced under mild conditions to generate a homogenous pool of Fab' fragments. The enzyme Kgp from Porphyromonas gingivalis has been applied to generate intact Fab fragments from human IgG1 and the Fab fragments can be purified using a CH1-specific affinity resin. The SpeB protease, also from S. pyogenes, is able to digest mouse IgGs and has been applied to digest antibodies and Fab fragments can be purified on light chain affinity resins. In this chapter, we describe methodologies that can be used to obtain Fab fragments from human and mouse IgG using bacterial proteases.

  8. Primary biliary cirrhosis is characterized by IgG3 antibodies cross-reactive with the major mitochondrial autoepitope and its Lactobacillus mimic.

    Science.gov (United States)

    Bogdanos, Dimitrios-Petrou; Baum, Harold; Okamoto, Manabu; Montalto, Paolo; Sharma, Umesh C; Rigopoulou, Eirini I; Vlachogiannakos, John; Ma, Yun; Burroughs, Andrew K; Vergani, Diego

    2005-08-01

    The serological hallmark of primary biliary cirrhosis (PBC) is the presence of pyruvate dehydrogenase complex E2 subunit (PDC-E2) antimitochondrial antibodies (AMAs). Anti-PDC-E2 antibodies cross-react specifically with mycobacterial hsp65, and we have demonstrated that the motif SxGDL[ILV]AE shared by PDC-E2(212-226) and hsp's is a cross-reactive target. Having found that this same motif is present only in beta-galactosidase of Lactobacillus delbrueckii (BGAL LACDE), we hypothesized that this homology would also lead to cross-reactivity. The mimics were tested via ELISA for reactivity and competitive cross-reactivity using sera from 100 AMA-positive and 23 AMA-negative PBC patients and 190 controls. An Escherichia coli (ECOLI) PDC-E2 mimic that has been pathogenetically linked to PBC but lacks this motif has been also tested. Anti-BGAL(266-280) LACDE antibodies were restricted to AMA-positive patients (54 of 95, 57%) and belonged to immunoglobulin (Ig) G3. Of the 190 controls, 22 (12%; P ECOLI PDC-E2 reactivity was virtually absent. BGAL(266-280)/PDC-E2(212-226) reactivity of the IgG3 isotype was found in 52 (52%) AMA-positive PBC patients but in only 1 of the controls (P ECOLI PDC-E2 mimics. In conclusion, IgG3 antibodies to BGAL LACDE cross-react with the major mitochondrial autoepitope and are characteristic of PBC.

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

    OpenAIRE

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

    2017-01-01

    Background Multiple anti-PD-L1/PD-1 checkpoint monoclonal antibodies (MAb) have shown clear evidence of clinical benefit. All except one have been designed or engineered to omit the possibility to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) as a second potential mode of anti-tumor activity; the reason for this is the concern of lysis of PD-L1 positive immune cells. Avelumab is a fully human IgG1 MAb which has been shown in prior in vitro studies to mediate ADCC versus a range...

  10. Rabbit IgG antibodies against Phospholipase A2 from Crotalus durissus terrificus neutralize the lethal activity of the venom Los anticuerpos IgG de conejos anti-fosfolipasa A2 de Crotalus durissus terrificus neutralizan la actividad letal del veneno

    Directory of Open Access Journals (Sweden)

    Juan P. Rodríguez

    2006-12-01

    Full Text Available Crotalus durissus terrificus (C.d.t. (South American rattlesnake venom possesses myotoxic and neurotoxic activities, both of which are also expressed by crotoxin, the principal toxin of this venom. Crotoxin contains a basic phospholipase A2 (PLA2 and a non toxic acidic protein, crotapotin. We have produced and investigated the ability of IgG antibodies raised in rabbits against PLA2 to neutralize the lethality of the whole venom. PLA2 was isolated by gel filtration chromatography (Sephadex G-75. Specific antibodies were obtained by subcutaneous and intramuscular inoculation of PLA2 (700 µg with Freund adjuvant. Groups of six mice (20 + 2 g were inoculated with 0.5 ml i.p. of C. d. t. venom (4 µg or a mixture of venom that had been preincubated with the desired volume of IgG antibodies. Mortality, recorded 24 and 48 h after inoculation, showed that IgG anti-PLA2 were more effective than anticrotalic serum in neutralizing the lethal activity. These results demonstrate that it could be possible to obtain an anti-venom made by specific antibodies with a high level of protection against the lethal component of C.d.t. venom, and/or the inclusion of these antibodies as a supplement in heterologous anti-venoms.El veneno de Crotalus durissus terrificus (C.d.t. (Cascabel de Sud América posee actividad miotóxica y neurotóxica, actividades que también exhibe el complejo crotoxina, principal componente tóxico de este veneno. El complejo crotoxina está constituido por una fosfolipasa A2 básica (PLA2 y una proteína acídica no tóxica, el crotapotín. En este trabajo se estudió la capacidad neutralizante de anticuerpos IgG anti-PLA2 sobre la letalidad inducida por el veneno entero. El antígeno PLA2, fue aislado por cromatografía de filtración en gel (Sephadex G-75. Se inocularon conejos machos por vía subcutánea e intramuscular, con 700 µg de PLA2 y adyuvante para la obtención de anticuerpos específicos. La capacidad neutralizante del

  11. Immunoglobulin G4: an odd antibody

    NARCIS (Netherlands)

    Aalberse, R. C.; Stapel, S. O.; Schuurman, J.; Rispens, T.

    2009-01-01

    Despite its well-known association with IgE-mediated allergy, IgG4 antibodies still have several poorly understood characteristics. IgG4 is a very dynamic antibody: the antibody is involved in a continuous process of half-molecules (i.e. a heavy and attached light-chain) exchange. This process, also

  12. The apparent monovalency of human IgG4 is due to bispecificity

    NARCIS (Netherlands)

    Aalberse, R. C.; Schuurman, J.; van Ree, R.

    1999-01-01

    A hypothesis is put forward to explain the apparent monovalency of human IgG4. It is based upon the known instability of the IgG4 hinge. IgG4 is secreted as a regular bivalent antibody, but after secretion interacts with another IgG4 molecule. This interaction results in the exchange of half

  13. Next Generation Antibody Therapeutics Using Bispecific Antibody Technology.

    Science.gov (United States)

    Igawa, Tomoyuki

    2017-01-01

    Nearly fifty monoclonal antibodies have been approved to date, and the market for monoclonal antibodies is expected to continue to grow. Since global competition in the field of antibody therapeutics is intense, we need to establish novel antibody engineering technologies to provide true benefit for patients, with differentiated product values. Bispecific antibodies are among the next generation of antibody therapeutics that can bind to two different target antigens by the two arms of immunoglobulin G (IgG) molecule, and are thus believed to be applicable to various therapeutic needs. Until recently, large scale manufacturing of human IgG bispecific antibody was impossible. We have established a technology, named asymmetric re-engineering technology (ART)-Ig, to enable large scale manufacturing of bispecific antibodies. Three examples of next generation antibody therapeutics using ART-Ig technology are described. Recent updates on bispecific antibodies against factor IXa and factor X for the treatment of hemophilia A, bispecific antibodies against a tumor specific antigen and T cell surface marker CD3 for cancer immunotherapy, and bispecific antibodies against two different epitopes of soluble antigen with pH-dependent binding property for the elimination of soluble antigen from plasma are also described.

  14. Development of a new high-affinity human antibody with antitumor activity against solid and blood malignancies.

    Science.gov (United States)

    Sioud, Mouldy; Westby, Phuong; Vasovic, Vlada; Fløisand, Yngvar; Peng, Qian

    2018-04-16

    mAbs have emerged as a promising strategy for the treatment of cancer. However, in several malignancies, no effective antitumor mAbs are yet available. Identifying therapeutic mAbs that recognize common tumor antigens could render the treatment widely applicable. Here, a human single-chain variable fragment (scFv) antibody library was sequentially affinity selected against a panel of human cancer cell lines and an antibody fragment (named MS5) that bound to solid and blood cancer cells was identified. The MS5 scFv was fused to the human IgG1 Fc domain to generate an antibody (MS5-Fc fusion) that induced antibody-dependent cellular cytotoxicity and phagocytosis of cancer cells by macrophages. In addition, the MS5-Fc antibody bound to primary leukemia cells and induced antibody-dependent cellular cytotoxicity. In the majority of analyzed cancer cells, the MS5-Fc antibody induced cell surface redistribution of the receptor complexes, but not internalization, thus maximizing the accessibility of the IgG1 Fc domain to immune effector cells. In vitro stability studies showed that the MS5-Fc antibody was stable after 6 d of incubation in human serum, retaining ∼60% of its initial intact form. After intravenous injections, the antibody localized into tumor tissues and inhibited the growth of 3 different human tumor xenografts (breast, lymphoma, and leukemia). These antitumor effects were associated with tumor infiltration by macrophages and NK cells. In the Ramos B-cell lymphoma xenograft model, the MS5-Fc antibody exhibited a comparable antitumor effect as rituximab, a chimeric anti-CD20 IgG1 mAb. These results indicate that human antibodies with pan-cancer abilities can be generated from phage display libraries, and that the engineered MS5-Fc antibody could be an attractive agent for further clinical investigation.-Sioud, M., Westby, P., Vasovic, V., Fløisand, Y., Peng, Q. Development of a new high-affinity human antibody with antitumor activity against solid and

  15. Sensitivity of some Immunoglobulin G class and subclass antibodies ...

    African Journals Online (AJOL)

    Indirect sandwich enzyme-linked immunosorbent assay (ELISA) was used to measure serum antibody responses in onchocerciasis patients. Apparently, IgG antibody class was more sensitive than IgG1, IgG3 and IgG4 responses to Onchocerca volvulus adult worms sodium duodecyl sulphate (SDS) extracted crude ...

  16. Isolation of Mal d 1 and Api g 1 - specific recombinant antibodies from mouse IgG Fab fragment libraries - Mal d 1-specific antibody exhibits cross-reactivity against Bet v 1.

    Science.gov (United States)

    Haka, Jaana; Niemi, Merja H; Iljin, Kristiina; Reddy, Vanga Siva; Takkinen, Kristiina; Laukkanen, Marja-Leena

    2015-05-27

    Around 3-5% of the population suffer from IgE-mediated food allergies in Western countries and the number of food-allergenic people is increasing. Individuals with certain pollen allergies may also suffer from a sensitisation to proteins in the food products. As an example a person sensitised to the major birch pollen allergen, Bet v 1, is often sensitised to its homologues, such as the major allergens of apple, Mal d 1, and celery, Api g 1, as well. Development of tools for the reliable, sensitive and quick detection of allergens present in various food products is essential for allergic persons to prevent the consumption of substances causing mild and even life-threatening immune responses. The use of monoclonal antibodies would ensure the specific detection of the harmful food content for a sensitised person. Mouse IgG antibody libraries were constructed from immunised mice and specific recombinant antibodies for Mal d 1 and Api g 1 were isolated from the libraries by phage display. More detailed characterisation of the resulting antibodies was carried out using ELISA, SPR experiments and immunoprecipitation assays. The allergen-specific Fab fragments exhibited high affinity towards the target recombinant allergens. Furthermore, the Fab fragments also recognised native allergens from natural sources. Interestingly, isolated Mal d 1-specific antibody bound also to Bet v 1, the main allergen eliciting the cross-reactivity syndrome between the birch pollen and apple. Despite the similarities in Api g 1 and Bet v 1 tertiary structures, the isolated Api g 1-specific antibodies showed no cross-reactivity to Bet v 1. Here, high-affinity allergen-specific recombinant antibodies were isolated with interesting binding properties. With further development, these antibodies can be utilised as tools for the specific and reliable detection of allergens from different consumable products. This study gives new preliminary insights to elucidate the mechanism behind the pollen

  17. Purification of polyclonal IgG specific for Camelid’s antibodies and their recombinant nanobodies

    Directory of Open Access Journals (Sweden)

    Haddad Muhammad

    2016-01-01

    Full Text Available Camelid’ s heavy-chain antibody (HCAb consists of only two heavy chains and lacks the two light chains together with the CH1 domain usually found in conventional immunoglobulins. A recombinant single antigen-binding entity, named VHH (or Nanobody® was generated by reengineering the variable domains from HCAb. This study focuses on the detection of camelid´s immunoglobulins as well as their derivative nanobodies using a universal anti-camel antibody produced in rabbit (rIgG. Starting from a crude rabbit serum, a standard stock of rIgG (1 mg/ml was prepared after purification by affinity chromatography using protein-A column. As expected, rIgG was able to detect camel antibodies in ELISA and immunoblotting, and its reactivity was equal against all different camel IgG subclasses, which were purified from serum by differential affinity chromatography on protein-G and -A. Interestingly, rIgG also recognized nanobodies since they were originally part of camel HCAbs, providing an alternative method to detect the corpus of these recombinant proteins rather than targeting their artificial tags. These data suggest that the anti-camel rIgG described here could be efficiently applied at different stages of nanobody technology, including the quantitation of the issued nanobodies and their detection when bound to target antigens.

  18. Estimation of polyclonal IgG4 hybrids in normal human serum.

    Science.gov (United States)

    Young, Elizabeth; Lock, Emma; Ward, Douglas G; Cook, Alexander; Harding, Stephen; Wallis, Gregg L F

    2014-07-01

    The in vivo or in vitro formation of IgG4 hybrid molecules, wherein the immunoglobulins have exchanged half molecules, has previously been reported under experimental conditions. Here we estimate the incidence of polyclonal IgG4 hybrids in normal human serum and comment on the existence of IgG4 molecules with different immunoglobulin light chains. Polyclonal IgG4 was purified from pooled or individual donor human sera and sequentially fractionated using light-chain affinity and size exclusion chromatography. Fractions were analysed by SDS-PAGE, immunoblotting, ELISA, immunodiffusion and matrix-assisted laser-desorption mass spectrometry. Polyclonal IgG4 purified from normal serum contained IgG4κ, IgG4λ and IgG4κ/λ molecules. Size exclusion chromatography showed that IgG4 was principally present in monomeric form (150 000 MW). SDS-PAGE, immunoblotting and ELISA showed the purity of the three IgG4 samples. Immunodiffusion, light-chain sandwich ELISA and mass spectrometry demonstrated that both κ and λ light chains were present on only the IgG4κ/λ molecules. The amounts of IgG4κ/λ hybrid molecules ranged from 21 to 33% from the five sera analysed. Based on the molecular weight these molecules were formed of two IgG4 heavy chains plus one κ and one λ light chain. Polyclonal IgG (IgG4-depleted) was similarly fractionated according to light-chain specificity. No evidence of hybrid IgG κ/λ antibodies was observed. These results indicate that hybrid IgG4κ/λ antibodies compose a substantial portion of IgG4 from normal human serum. © 2014 John Wiley & Sons Ltd.

  19. Different Somatic Hypermutation Levels among Antibody Subclasses Disclosed by a New Next-Generation Sequencing-Based Antibody Repertoire Analysis

    Directory of Open Access Journals (Sweden)

    Kazutaka Kitaura

    2017-05-01

    Full Text Available A diverse antibody repertoire is primarily generated by the rearrangement of V, D, and J genes and subsequent somatic hypermutation (SHM. Class-switch recombination (CSR produces various isotypes and subclasses with different functional properties. Although antibody isotypes and subclasses are considered to be produced by both direct and sequential CSR, it is still not fully understood how SHMs accumulate during the process in which antibody subclasses are generated. Here, we developed a new next-generation sequencing (NGS-based antibody repertoire analysis capable of identifying all antibody isotype and subclass genes and used it to examine the peripheral blood mononuclear cells of 12 healthy individuals. Using a total of 5,480,040 sequences, we compared percentage frequency of variable (V, junctional (J sequence, and a combination of V and J, diversity, length, and amino acid compositions of CDR3, SHM, and shared clones in the IgM, IgD, IgG3, IgG1, IgG2, IgG4, IgA1, IgE, and IgA2 genes. The usage and diversity were similar among the immunoglobulin (Ig subclasses. Clonally related sequences sharing identical V, D, J, and CDR3 amino acid sequences were frequently found within multiple Ig subclasses, especially between IgG1 and IgG2 or IgA1 and IgA2. SHM occurred most frequently in IgG4, while IgG3 genes were the least mutated among all IgG subclasses. The shared clones had almost the same SHM levels among Ig subclasses, while subclass-specific clones had different levels of SHM dependent on the genomic location. Given the sequential CSR, these results suggest that CSR occurs sequentially over multiple subclasses in the order corresponding to the genomic location of IGHCs, but CSR is likely to occur more quickly than SHMs accumulate within Ig genes under physiological conditions. NGS-based antibody repertoire analysis should provide critical information on how various antibodies are generated in the immune system.

  20. Assessment of IgG Antibodies Against HSV1, HSV2, CMV and EBV in Patients with Pemphigus Vulgaris versus Healthy People

    Directory of Open Access Journals (Sweden)

    Parichehr Ghalayani

    2016-08-01

    Full Text Available Objectives: Regarding the implication of viruses particularly herpes in pemphigus vulgaris, we sought to assess and compare the level of immunoglobulin G (IgG antibodies against herpes simplex virus types 1 and 2 (HSV1 and HSV2, cytomegalovirus (CMV and Epstein-Barr virus (EBV in patients with pemphigus vulgaris and healthy people.    Materials and Methods: In this cross-sectional study, 25 patients with pemphigus vulgaris and 27 healthy individuals comprised the experimental and control groups, respectively. Serum samples were taken from both groups; the levels of IgG antibodies against HSV1, HSV2, CMV and EBV were measured using ELISA.  Results: Immunoglobulin G titer was higher for all four viruses in the patient group in comparison to the control group. This difference was significant for anti-EBV (P= 0.005, anti-CMV (P=0.0001 and anti-HSV2 (P=0.001 but not significant for anti-HSV1 (P= 0.36.Conclusion: Viruses including EBV, CMV, and HSV2 probably play a role in the pathogenesis of pemphigus in addition to the effects of genetics, toxins and other predisposing factors. In this study, no statistically significant relationship was observed between HSV1 and pemphigus vulgaris, which was probably due to the high titer of anti-HSV1 IgG in healthy individuals in the community. More studies must be done in this regard.

  1. Long-term clinical protection from falciparum malaria is strongly associated with IgG3 antibodies to merozoite surface protein 3.

    Directory of Open Access Journals (Sweden)

    Christian Roussilhon

    2007-11-01

    Full Text Available BACKGROUND: Surrogate markers of protective immunity to malaria in humans are needed to rationalize malaria vaccine discovery and development. In an effort to identify such markers, and thereby provide a clue to the complex equation malaria vaccine development is facing, we investigated the relationship between protection acquired through exposure in the field with naturally occurring immune responses (i.e., induced by the parasite to molecules that are considered as valuable vaccine candidates. METHODS AND FINDINGS: We analyzed, under comparative conditions, the antibody responses of each of six isotypes to five leading malaria vaccine candidates in relation to protection acquired by exposure to natural challenges in 217 of the 247 inhabitants of the African village of Dielmo, Senegal (96 children and 121 older adolescents and adults. The status of susceptibility or resistance to malaria was determined by active case detection performed daily by medical doctors over 6 y from a unique follow-up study of this village. Of the 30 immune responses measured, only one, antibodies of the IgG3 isotype directed to merozoite surface protein 3 (MSP3, was strongly associated with clinical protection against malaria in all age groups, i.e., independently of age. This immunological parameter had a higher statistical significance than the sickle cell trait, the strongest factor of protection known against Plasmodium falciparum. A single determination of antibody was significantly associated with the clinical outcome over six consecutive years in children submitted to massive natural parasite challenges by mosquitoes (over three parasite inoculations per week. Finally, the target epitopes of these antibodies were found to be fully conserved. CONCLUSIONS: Since anti-MSP3 IgG3 antibodies can naturally develop along with protection against P. falciparum infection in young children, our results provide the encouraging indication that these antibodies should be

  2. Evaluation of anti-Schistosoma mansoni igG antibodies in patients with chronic schistosomiasis mansoni before and after specific treatment Avaliação da presença de anticorpos IgG anti-Schistosoma mansoni no soro de pacientes com esquistossomose mansônica crônica, antes e após tratamento específico

    Directory of Open Access Journals (Sweden)

    Célia Maria V. VENDRAME

    2001-06-01

    Full Text Available The circumoval precipitin test (COPT, enzyme-linked immunosorbent assay (ELISA and the immunoblotting anti-adult worm antigen (AWA and soluble egg antigen (SEA tests were applied to 17 chronically schistosome-infected patients for the detection of anti-Schistosoma mansoni antibodies before and on four occasions after oxamniquine administration over a period of six months. Compared to a control group, schistosomiasis patients showed high levels of IgG antibodies in AWA and SEA-ELISA. A decrease in IgG levels was observed six months after treatment, although negative reactions were not obtained. Significant decreases in IgG1, IgG3 and, mainly, IgG4, but not anti-SEA IgG2 levels were observed six months after treatment, again without negativity. Analysis of anti-AWA IgG antibodies by immunoblotting before treatment showed a 31 kDa strand in 14 patients (82% which disappeared in three cases up to six months after treatment; furthermore, anti-SEA IgG antibodies showed the same band in nine patients (53% before treatment, which disappeared in only four cases up to six months after treatment.Em 17 pacientes com infecção crônica por Schistosoma mansoni utilizaram-se os testes de reação periovular, imunoenzimático (ELISA e imunoblotting, empregando-se antígenos obtidos a partir de vermes adultos (AWA ou de ovos de S. mansoni (SEA, para detecção de anticorpos anti-S. mansoni, antes e em quatro ocasiões após tratamento com oxamniquine. Quando cotejados a grupo controle os pacientes esquistossomóticos revelaram altos níveis séricos de anticorpos IgG nos testes ELISA (anti-AWA e anti-SEA, não se observando, porém, negativação até seis meses após tratamento específico. Encontrou-se, entretanto, decréscimo significativo, sem negativação, dos níveis de IgG1, IgG3 e, principalmente, IgG4, quando se utilizou antígeno solúvel obtido a partir de ovos de S. mansoni (SEA, seis meses após administração de oxamniquine. O mesmo não foi

  3. Fc-Glycosylation in Human IgG1 and IgG3 Is Similar for Both Total and Anti-Red-Blood Cell Anti-K Antibodies

    Directory of Open Access Journals (Sweden)

    Myrthe E. Sonneveld

    2018-01-01

    Full Text Available After albumin, immunoglobulin G (IgG are the most abundant proteins in human serum, with IgG1 and IgG3 being the most abundant subclasses directed against protein antigens. The quality of the IgG-Fc-glycosylation has important functional consequences, which have been found to be skewed toward low fucosylation in some antigen-specific immune responses. This increases the affinity to IgG1-Fc-receptor (FcγRIIIa/b and thereby directly affects downstream effector functions and disease severity. To date, antigen-specific IgG-glycosylation have not been analyzed for IgG3. Here, we analyzed 30 pregnant women with anti-K alloantibodies from a prospective screening cohort and compared the type of Fc-tail glycosylation of total serum- and antigen-specific IgG1 and IgG3 using mass spectrometry. Total serum IgG1 and IgG3 Fc-glycoprofiles were highly similar. Fc glycosylation of antigen-specific IgG varied greatly between individuals, but correlated significantly with each other for IgG1 and IgG3, except for bisection. However, although the magnitude of changes in fucosylation and galactosylation were similar for both subclasses, this was not the case for sialylation levels, which were significantly higher for both total and anti-K IgG3. We found that the combination of relative IgG1 and IgG3 Fc-glycosylation levels did not improve the prediction of anti-K mediated disease over IgG1 alone. In conclusion, Fc-glycosylation profiles of serum- and antigen-specific IgG1 and IgG3 are highly similar.

  4. Production of double antibody for radioimmunoassay (sheep anti-rabbit IgG antiserum); Producao de duplo anticorpo para radioimunoensaio (antissoro de carneiro anti-IgG de coelho)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, S.R. da

    1994-12-31

    A second antibody (sheep anti-rabbit IgG antiserum) to be used in RIAs in which the first antibody is raised in rabbits was produced. For this production, initially the IgG was isolated from rabbit serum and purified by sodium sulphate precipitation followed by ion exchange chromatography on DEAE-cellulose. Four sheep were immunized with 500 u g of purified rabbit IgG, emulsified in Freund Complete Adjuvant and administered by multisite subcutaneous injections. These injections were repeated at 20-days intervals and blood samples (40 ml) were taken from the jugular vein 10 days after the boosts for the evaluation of the antisera title. After each four boosts a great bleeding was done by the same route. Approximately 500 ml of serum were obtained in each bleeding per animal. The antisera were evaluated by the human thyrotropin RIA developed at IPEN laboratories employing reagents provided by NIDDKD, USA. These evaluations referred to the determination of the antisera title and of the ideal concentration of carrier IgG, to the study of the kinetic of precipitation and to the confirmation of the inexistent cross-reactivity with human IgG, in comparison with a reference antiserum of know precipitation characteristics supplied by the Radioassay System Laboratories. Approximately 3,6 l of antiserum (sheep anti-rabbit IgG serum) were produced from the four sheep, which presented title and precipitation characteristics very similar to those exhibited by the imported commercial product, even presenting higher titles. The results obtained in this work indicated that it was created enough experience for the production of this biological reagent for RIA, that could be done integrally in the country in greater scale, and at a very reduced cost. (author). 81 refs, 36 figs, 33 tabs.

  5. Duration of detection of anti-BmR1 IgG4 antibodies after mass-drug administration (MDA) in Sarawak, Malaysia.

    Science.gov (United States)

    Noordin, R; Muhi, J; Md Idris, Z; Arifin, N; Kiyu, A

    2012-03-01

    The detection rates of brugian filariasis in three regions of Sarawak namely Central, North and South after three courses of mass drug administration (MDA) from year 2004 to 2006 was investigated. A recombinant BmR1 antigen-based IgG4 detection test, named Brugia Rapid and night blood smear for microfilaria (mf) detection were used. All three regions recorded a sharp fall in mf positive rates after a year post-MDA. Meanwhile Brugia Rapid positive rates declined more gradually to 3.8% and 5.6% of the pre-MDA levels in the Central and North regions, respectively. This study showed that in filariasis endemic areas in Sarawak, anti-filarial IgG4 antibodies to BmR1, as detected by the Brugia Rapid test, were positive for one to two years after mf disappearance.

  6. Leaky RAG Deficiency in Adult Patients with Impaired Antibody Production against Bacterial Polysaccharide Antigens.

    Directory of Open Access Journals (Sweden)

    Christoph B Geier

    Full Text Available Loss of function mutations in the recombination activating genes RAG1 and RAG2 have been reported to cause a T-B-NK+ type of severe combined immunodeficiency. In addition identification of hypomorphic mutations in RAG1 and RAG2 has led to an expansion of the spectrum of disease to include Omenn syndrome, early onset autoimmunity, granuloma, chronic cytomegalovirus- or EBV-infection with expansion of gamma/delta T-cells, idiophatic CD4 lymphopenia and a phenotype resembling common variable immunodeficiency. Herein we describe a novel presentation of leaky RAG1 and RAG2 deficiency in two unrelated adult patients with impaired antibody production against bacterial polysaccharide antigens. Clinical manifestation included recurrent pneumonia, sinusitis, otitis media and in one patient recurrent cutaneous vasculitis. Both patients harbored a combination of a null mutation on one allele with a novel hypomorphic RAG1/2 mutation on the other allele. One of these novel mutations affected the start codon of RAG1 and resulted in an aberrant gene and protein expression. The second novel RAG2 mutation leads to a truncated RAG2 protein, lacking the C-terminus with intact core RAG2 and reduced VDJ recombination capacity as previously described in a mouse model. Both patients presented with severely decreased numbers of naïve CD4+ T cells and defective T independent IgG responses to bacterial polysaccharide antigens, while T cell-dependent IgG antibody formation e.g. after tetanus or TBEV vaccination was intact. In conclusion, hypomorphic mutations in genes responsible for SCID should be considered in adults with predominantly antibody deficiency.

  7. Characteristics of primary Sjögren's syndrome patients with IgG4 positive plasma cells infiltration in the labial salivary glands.

    Science.gov (United States)

    Liu, Chang; Zhang, Huayong; Yao, Genhong; Hu, Yunxia; Qi, Jingjing; Wang, Yan; Chen, Weiwei; Tang, Xiaojun; Li, Wenchao; Lu, Liwei; Gu, Luo; Sun, Lingyun

    2017-01-01

    The purpose of this study was to investigate the characteristics of primary Sjögren's syndrome (pSS) patients with IgG4 positive (IgG4 + ) plasma cell infiltration in labial salivary glands (LSGs). Paraffin sections of LSGs from 336 pSS patients were stained with IgG4 and IgG monoclonal antibodies. According to the infiltration of IgG4 + plasma cells, patients were divided and clinical and serological characteristics were analyzed and compared. Based on the infiltration of IgG4 + plasma cells in the LSGs, patients were divided into three subgroups, low IgG4, moderate IgG4, and high IgG4 groups. A negative association between the number of infiltrated IgG4 + plasma cells and the disease characteristics was observed. We found that the higher the IgG4 + expression in plasma cells, the lower the positive rates of serum anti-SSA antibodies, anti-SSB antibodies, antinuclear antibodies (ANA), and rheumatoid factor (RF). Besides, patients from the high IgG4 group had the highest frequency of interstitial lung disease (ILD, 30.6%) and tubulointerstitial nephritis (TIN, 13.9%), but the lowest frequency of leucopenia (13.9%), thrombocytopenia (11.1%), and abnormal thyroidal function (0%). PSS patients with different IgG4 + plasma cells infiltration in the LSGs had distinctive clinical and laboratory characteristics. It may help us to further understand the role of IgG4 + plasma cells in pSS.

  8. IgG western blot for confirmatory diagnosis of equivocal cases of toxoplasmosis by EIA-IgG and fluorescent antibody test.

    Science.gov (United States)

    Khammari, Imen; Saghrouni, Fatma; Yaacoub, Alia; Gaied Meksi, Sondoss; Ach, Hinda; Garma, Lamia; Fathallah, Akila; Ben Saïd, Moncef

    2013-08-01

    The performance values of available techniques used in serodiagnosis of toxoplasmosis are satisfactory but they raise problems of equivocal and discordant results for very low IgG titers. Recently marketed, LDBio-Toxo II IgG Western blot (IB) showed an excellent correlation with the dye test. We estimated the proportion of equivocal and discordant results between the enzyme immunoassay Platelia Toxo IgG (EIA-IgG) and fluorescent antibody test (FAT) and assessed the usefulness of the IB as a confirmatory test. Out of 2,136 sera collected from pregnant women, 1,644 (77.0%) tested unequivocally positive and 407 (19.0%) were negative in both EIA-IgG and FAT. The remaining 85 (4%) sera showed equivocal or discordant results. Among them, 73 (85.9%) were positive and 12 (14.1%) were negative in IB. Forty-one (89.1%) equivocal sera in EIA-IgG and 46 (86.8%) equivocal sera in FAT were positive in IB. Reducing the cut-off values of both screening techniques improved significantly their sensitivity in detecting very low IgG titers at the expense of their specificity. In conclusion, equivocal results in routine-used techniques and their discordance in determination of the immune status in pregnancy women were not uncommon. IB test appeard to be highly useful in these situations as a confirmatory technique.

  9. Simultaneous detection of IgG antibodies associated with viral hemorrhagic fever by a multiplexed Luminex-based immunoassay.

    Science.gov (United States)

    Wu, Wei; Zhang, Shuo; Qu, Jing; Zhang, Quanfu; Li, Chuan; Li, Jiandong; Jin, Cong; Liang, Mifang; Li, Dexin

    2014-07-17

    Viral hemorrhagic fevers (VHFs) are worldwide diseases caused by several kinds of viruses. With the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of VHFs. Based on Luminex xMAP technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (HFVs) specific IgG antibodies was developed. Recombinant antigens of nine HFVs including Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), Andes virus (ANDV), Sin Nombre virus (SNV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) and dengue virus (DENV) were produced and purified from a prokaryotic expression system and the influence of the coupling amount was investigated. Cross-reactions among antigens and their rabbit immune sera were evaluated. Serum samples collected from 51 laboratory confirmed hemorrhagic fever with renal syndrome (HFRS) patients, 43 confirmed SFTS patients and 88 healthy donors were analyzed. Results showed that recombinant nucleocapsid protein of the five viruses belonging to the genus Hantavirus, had serological cross-reactivity with their corresponding rabbit immune sera, but not apparent with immune sera of other four viruses. Evaluation of this new method with clinical serum samples showed 98.04% diagnostic sensitivity for HFRS, 90.70% for SFTS detection and the specificity was ranging from 66.67% to 100.00%. The multiplexed Luminex-based immunoassay has firstly been established in our study, which provides a potentially reliable diagnostic tool for IgG antibody detection of VHFs. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. ANTIBODIES TO LEUKEMIA DIFFERENTIATION FACTOR (HLDF IN PATIENTS WITH GASTROINTESTINAL CANCER

    Directory of Open Access Journals (Sweden)

    A. I. Autenshlus

    2010-01-01

    Full Text Available Antibodies to leukemia differentiation factor (HLDF in patients with gastrointestinal cancer Abstract. Patients with gastric cancer exhibit higher levels of IgG4-antibodies to human leukemia differentiation factor (HLDF, as compared with healthy individuals, whereas, in patients with colorectal cancer, one may detect high levels of IgA anti-HDLF antibodies, along with lower levels of IgG1 class antibodies against HLDF than in control group. Among patients with gastrointestinal cancer, a positive correlation is revealed between contents of highly differentiated cells in the tumor, and IgM antibodies to HDLF. Meanwhile, a reverse relationship is noted between low differentiation of tumor cells and levels of IgG2 antibodies to HDLF in gastric cancer patients, or IgG3 antibodies to HDLF in patients with colorectal cancer.

  11. Kinetics of IgG antibody to cytomegalovirus (CMV) after birth and seroprevalence of anti-CMV IgG in Chinese children.

    Science.gov (United States)

    Chen, Jie; Hu, Lingqing; Wu, Meiling; Zhong, Tianying; Zhou, Yi-Hua; Hu, Yali

    2012-12-10

    Prevalence of cytomegalovirus (CMV) infection is 90-100% in developing countries; however, the kinetics of anti-CMV IgG in infants remains elusive. Sera from 112 mother-newborn pairs and longitudinal samples from 41 infants up to 2-year old were tested for anti-CMV IgG and IgM. Additionally, samples from 837 healthy children were included. Of 112 mothers, 108 (96.4%) were anti-CMV IgG positive; their 108 newborns were also seropositive. In a 2-year follow-up among 40 infants of positive mothers, anti-CMV IgG level in 8 individuals decreased with time and became undetectable by age of 3.5-8 months, and that in 32 others decreased at 1- and 3.5-month old, and then increased. Based on the positive IgM, rising IgG levels, and low anti-CMV IgG avidity index, 76.7% of the primary infections were demonstrated to occur during 1-3.5 months of age. The overall seroprevalence of anti-CMV in 837 children was 82.4%, which was generally constant from 2 to 8 years old (χ2 = 3.150, p = 0.790). The maternally acquired anti-CMV IgG in infants disappears before 8-month old. Primary CMV infection in Chinese children mostly occurs during 1-3.5 months of age. Whether the relatively lower seroprevalence of anti-CMV in Chinese children found in this survey may reflect the positive rate in child-bearing age women in the future remains to be further studied.

  12. Dose-dependent platelet stimulation and inhibition induced by anti-PIA1 IgG

    International Nuclear Information System (INIS)

    Ryu, T.; Davis, J.M.; Schwartz, K.A.

    1990-01-01

    The PIA1 antibody produces several clinically distinct and severe thrombocytopenias. Investigations have demonstrated divergent effects on platelet function; prior reports demonstrated inhibition, while a conflicting publication showed platelet activation. We have resolved this conflict using anti-PIA1 IgG produced by a patient with posttransfusion purpura. Relatively low concentrations stimulated platelet aggregation and release of adenosine triphosphate (ATP) whereas high concentrations inhibited platelet function, producing a thrombasthenia-like state. The number of molecules of platelet-associated IgG necessary to initiate aggregation and ATP release (2,086 +/- 556) or produce maximum aggregation (23,420 +/- 3,706) or complete inhibition (63,582 +/- 2654) were measured with a quantitative radiometric assay for bound anti-PIA1. Preincubation of platelets with high concentrations of PIA1 antibody inhibited platelet aggregation with 10 mumol/L adenosine diphosphate and blocked 125I-labeled fibrinogen platelet binding. Platelet activation with nonfibrinogen dependent agonist, 1 U/ml thrombin, was not inhibited by this high concentration of PIA1 IgG. In conclusion, anti-PIAI IgG produces (1) stimulation of platelet aggregation and ATP release that is initiated with 2000 molecules IgG per platelet and is associated with an increase of 125I-fibrinogen binding; (2) conversely, inhibition of platelet aggregation is observed with maximum antibody binding, 63,000 molecules IgG per platelet, and is mediated via a blockade of fibrinogen binding

  13. Structure of a mouse immunoglobulin G that lacks the entire CH1 domain: Protein sequencing and small-angle X-ray scattering studies

    International Nuclear Information System (INIS)

    Igarashi, Takako; Tanaka, Toshiyuki; Nakanishi, Mamoru; Arata, Yoji; Sato, Mamoru; Katsube, Yukiteru; Takio, Koji

    1990-01-01

    The structure of a short-chain IgG2a antibody, which is a member of the family of mouse anti-dansyl switch variant antibodies with identical variable regions but different heavy-chain constant regions, is reported. Amino acid sequencing analyses have demonstrated that in the short-chain IgG2a antibody the entire C H 1 domain is deleted whereas the hinge region remains intact. Small-angle X-ray scattering data were collected for the short-chain IgG2a antibody and compared with those for the switch variant IgG1, IgG2a, and IgG2b antibodies with the normal heavy chain. It has been concluded that deletion of the C H 1 domain results in a large structural change and the short-chain IgG2a antibody possesses an elongated molecular shape with a much smaller hinge angle as compared with the normal IgG2a antibody that is a Y-shaped molecule

  14. Structure of a mouse immunoglobulin G that lacks the entire C sub H 1 domain: Protein sequencing and small-angle X-ray scattering studies

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, Takako; Tanaka, Toshiyuki; Nakanishi, Mamoru; Arata, Yoji (Univ. of Tokyo (Japan)); Sato, Mamoru; Katsube, Yukiteru (Osaka Univ. (Japan)); Takio, Koji (Institute of Physical and Chemical Research, Saitama (Japan))

    1990-06-19

    The structure of a short-chain IgG2a antibody, which is a member of the family of mouse anti-dansyl switch variant antibodies with identical variable regions but different heavy-chain constant regions, is reported. Amino acid sequencing analyses have demonstrated that in the short-chain IgG2a antibody the entire C{sub H}1 domain is deleted whereas the hinge region remains intact. Small-angle X-ray scattering data were collected for the short-chain IgG2a antibody and compared with those for the switch variant IgG1, IgG2a, and IgG2b antibodies with the normal heavy chain. It has been concluded that deletion of the C{sub H}1 domain results in a large structural change and the short-chain IgG2a antibody possesses an elongated molecular shape with a much smaller hinge angle as compared with the normal IgG2a antibody that is a Y-shaped molecule.

  15. Domestic cat microsphere immunoassays: detection of antibodies during feline immunodeficiency virus infection.

    Science.gov (United States)

    Wood, Britta A; Carver, Scott; Troyer, Ryan M; Elder, John H; VandeWoude, Sue

    2013-10-31

    Microsphere immunoassays (MIAs) allow rapid and accurate evaluation of multiple analytes simultaneously within a biological sample. Here we describe the development and validation of domestic cat-specific MIAs for a) the quantification of total IgG and IgA levels in plasma, and b) the detection of IgG and IgA antibodies to feline immunodeficiency virus (FIV) capsid (CA) and surface (SU) proteins, and feline CD134 in plasma. These assays were used to examine the temporal antibody response of domestic cats infected with apathogenic and pathogenic FIVs, and domestic cats infected with parental and chimeric FIVs of varying pathogenicity. The results from these studies demonstrated that a) total IgG antibodies increase over time after infection; b) α-CA and α-SU IgG antibodies are detectable between 9 and 28 days post-infection and increase over time, and these antibodies combined represent a fraction (1.8 to 21.8%) of the total IgG increase due to infection; c) measurable α-CD134 IgG antibody levels vary among individuals and over time, and are not strongly correlated with viral load; d) circulating IgA antibodies, in general, do not increase during the early stage of infection; and e) total IgG, and α-CA and α-SU IgG antibody kinetics and levels vary with FIV viral strain/pathogenicity. The MIAs described here could be used to screen domestic cats for FIV infection, and to evaluate the FIV-specific or total antibody response elicited by various FIV strains/other diseases. © 2013.

  16. Monoclonal antibody

    International Nuclear Information System (INIS)

    Oyamada, Hiyoshimaru

    1987-01-01

    Some aspects of monoclonal antibodies are described, centering on studies made by the author and those presented at the Second International Conference on Monoclonal Antibody Immunoconjugates for Cancer held in March this year (1987). The history of immuno-nuclear medicine and procedures for producing monoclonal antibodies are briefly outlined. Monoclonal antibodies are immunoglobulins. Here, the structure of IgG, which is used most frequently, is described. An IgG is composed of two antigen binding fragments (Fab) and one crystallizable fragment (Fc). The end portion of a Fab reacts with an antigen. One of the major applications of immuno-nuclear medicine is the diagnosis of cancer. As label nucleides, 131 I and 111 I were selected in most cases in the past while 123 I and 99m Tc are currently used more often. Advantages and disadvantages of this diagnosis method is discussed citing studies presented at the First (1986) and Second (1987) International Conference on Monoclonal Antibody Immunoconjugates for Cancer. The present status of the application of monoclonal antibodies to treatment of cancer is also described. (Nogami, K.)

  17. Quantitative cumulative biodistribution of antibodies in mice

    Science.gov (United States)

    Yip, Victor; Palma, Enzo; Tesar, Devin B; Mundo, Eduardo E; Bumbaca, Daniela; Torres, Elizabeth K; Reyes, Noe A; Shen, Ben Q; Fielder, Paul J; Prabhu, Saileta; Khawli, Leslie A; Boswell, C Andrew

    2014-01-01

    The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn’s role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn’s role in antibody PK and catabolism at the tissue level. PMID:24572100

  18. Kinetics of IgG antibody to cytomegalovirus (CMV after birth and seroprevalence of anti-CMV IgG in Chinese children

    Directory of Open Access Journals (Sweden)

    Chen Jie

    2012-12-01

    Full Text Available Abstract Background Prevalence of cytomegalovirus (CMV infection is 90–100% in developing countries; however, the kinetics of anti-CMV IgG in infants remains elusive. Methods Sera from 112 mother-newborn pairs and longitudinal samples from 41 infants up to 2-year old were tested for anti-CMV IgG and IgM. Additionally, samples from 837 healthy children were included. Results Of 112 mothers, 108 (96.4% were anti-CMV IgG positive; their 108 newborns were also seropositive. In a 2-year follow-up among 40 infants of positive mothers, anti-CMV IgG level in 8 individuals decreased with time and became undetectable by age of 3.5–8 months, and that in 32 others decreased at 1- and 3.5-month old, and then increased. Based on the positive IgM, rising IgG levels, and low anti-CMV IgG avidity index, 76.7% of the primary infections were demonstrated to occur during 1–3.5 months of age. The overall seroprevalence of anti-CMV in 837 children was 82.4%, which was generally constant from 2 to 8 years old (χ2 = 3.150, p = 0.790. Conclusions The maternally acquired anti-CMV IgG in infants disappears before 8-month old. Primary CMV infection in Chinese children mostly occurs during 1–3.5 months of age. Whether the relatively lower seroprevalence of anti-CMV in Chinese children found in this survey may reflect the positive rate in child-bearing age women in the future remains to be further studied.

  19. [Detection of split products of the immunoglobulins IgG, IgA and IgM during chronic otitis media (author's transl)].

    Science.gov (United States)

    Kastenbauer, E R; Hochgesand, K; Hochstrasser, K; Tappermann, G

    1975-07-01

    Proteolytic enzymes such as pepsine or papaine are able to split IgG antibodies into large fragments in vitro. These immunoglobulin fragments (IgG, IgA, IgM) were now detected in vivo from the purulent secretions of cholesteatoma, chronic otitis media and radical mastoid cavities. During chronic otitis media the intact immunoglobulins are split due to the proteolytic activity of neutral proteinases. These fragments were qualitatively and quantitatively investigated by means of various immunological procedures. After the immunoelectrophoretic separation of the purulent middle-ear-secretions and after diffusion against anti-IgG-, anti-IgA- and anti-IgM- serum double precipitate lines could be observed especially in middle-ear-secretion with a bacterial flora of pseudomonas aeruginosa (pyocyanea) and of the proteus-providencia-group. This was the first proof of the presence of split products of the immunoglobulins. The exact demonstration of these split products could be carried out by gel-filtration and fractionation of the intact and split immunoglobulins. During chronic otitis media intact immunoglobulins are split by leucocytic and extracellular bacterial proteinases into fragments of different molecular weight. The most malignant extracellular proteinases with the greatest proteolytic activity against intact immunoglobulins are the bacterial proteinases of pseudomonas aeruginosa. These proteinases can not be inhibited by the other serum proteinaseinhibitors except for alpha-2-macroglobulin of the human blood serum. This inhibitor has a very high molecular weight so that we can not find it in a higher concentration in the middle-ear-secretion. We can liberate this inhibitor by injuring the blood vessels during a tympanoplasty. In this way we get an inhibitory effect against these proteinases and combined with an appropriate antibiotic therapy we can cure a chronic otitis media.

  20. Quantitation of parasite-specific human IgG and IgE in sera: evaluation of solid-phase RIA and ELISA methodology

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, R G [Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Medicine; Hussain, R; Ottesen, E A [National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA); Adkinson, Jr, N F [Johns Hopkins Univ., Baltimore, MD (USA). School of Medicine

    1981-07-17

    The authors have developed a non-competitive solid-phase radioimmunoassay (SPRIA) to quantitate both human IgE and IgG antibodies against soluble adult antigens of Brugia malayi (B.m.), a filarial parasite causing extensive infection throughout the tropics. Previously enzyme-linked immunosorbent assays (ELISA) had been used to detect ..mu..g/ml levels of IgG anti-B.m., but IgE antibodies were difficult to detect in this system. Since the SPRIA successfully quantitates both IgG and IgE anti-B.m., they sought to examine the reasons for the SPRIA's apparent superiority in detecting IgE anti-B.m. by extracting specific IgG from sera with high levels of IgE and IgG anti-B.m. antibodies. IgE anti-B.m. was then quantitated in these sera using both the SPRIA and ELISA methods. Results indicate that IgG anti-B.m. does not interfere with detection of specific IgE antibody in the SPRIA but does interfere in the ELISA. While ELISA permits detection of IgE anti-B.m. in the absence of competing IgG anti-B.m., as levels of specific IgG increase, the IgE is no longer detectable. These differences between SPRIA and ELISA can be explained by the SPRIA's antigen excess conditions which assure that there are sufficient antigens both to detect all anti-B.m. antibodies present in the serum and to adequately represent all antigen specificities in the crude B.m. extract. Their findings commend the use of SPRIA methods over ELISA in assessment of B.m.-specific IgE antibody in filariasis and indicate a potential role for SPRIA methods in absolute quantitation of specific serum antibodies.

  1. Quantification of the IgG2/4 kappa Monoclonal Therapeutic Eculizumab from Serum Using Isotype Specific Affinity Purification and Microflow LC-ESI-Q-TOF Mass Spectrometry.

    Science.gov (United States)

    Ladwig, Paula M; Barnidge, David R; Willrich, Maria A V

    2017-05-01

    As therapeutic monoclonal antibodies (mAbs) become more humanized, traditional tryptic peptide approaches used to measure biologics in serum become more challenging since unique clonotypic peptides used for quantifying the mAb may also be found in the normal serum polyclonal background. An alternative approach is to monitor the unique molecular mass of the intact light chain portion of the mAbs using liquid chromatography-mass spectrometry (LC-MS). Distinguishing a therapeutic mAb from a patient's normal polyclonal immunoglobulin (Ig) repertoire is the primary limiting factor when determining the limit of quantitation (LOQ) in serum. The ability to selectively extract subclass specific Igs from serum reduces the polyclonal background in a sample. We present here the development of an LC-MS method to quantify eculizumab in serum. Eculizumab is a complement component 5 (C5) binding mAb that is fully humanized and contains portions of both IgG2 and IgG4 subclasses. Our group developed a method that uses Life Technologies CaptureSelect IgG4 (Hu) affinity matrix. We show here the ability to quantitate eculizumab with a LOQ of 5 mcg/mL by removing the higher abundance IgG1, IgG2, and IgG3 from the polyclonal background, making this approach a simple and efficient procedure. Graphical Abstract ᅟ.

  2. Elevated serum antiphospholipid antibodies in adults with celiac disease.

    Science.gov (United States)

    Laine, Outi; Pitkänen, Katariina; Lindfors, Katri; Huhtala, Heini; Niemelä, Onni; Collin, Pekka; Kurppa, Kalle; Kaukinen, Katri

    2018-05-01

    An increased incidence of thrombosis is suggested in celiac disease. We explored serum levels of antiphospholipid antibodies in untreated and treated adult celiac disease patients. A cohort of 179 biopsy-proven celiac disease patients (89 untreated, 90 on long-term gluten-free diet) and 91 non-celiac controls underwent clinical examination, assessment of celiac serology and enzyme immunoassay testing for anticardiolipin IgG and IgM, prothrombin IgG, and phosphatidylserine-prothrombin IgG and IgM. The level of antiphospholipid antibodies was higher in celiac disease patients compared with controls: anticardiolipin IgG 4.9 (0.7-33.8) vs 2.2 (0.4-9.6) U/ml, antiprothrombin IgG 2.9 (0.3-87.8) vs 2.1 (0.5-187.0) U/ml, antiphosphatidylserine-prothrombin IgG 6.9 (0.0-54.1) vs 2.3 (0.5-15.1) U/ml; p celiac disease at presentation (gastrointestinal symptoms, malabsorption or anemia, and extraintestinal symptoms or screen-detected disease) had no effect on the level of serum antiphospholipid antibodies. The serum level of antiphospholipid antibodies is increased in adults with celiac disease. The higher level of antibodies in treated patients suggests that the increase is not gluten-dependent. The prothrombotic role of antiphospholipid antibodies in celiac disease warrants further studies. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  3. Kinetics of IgG antibody to cytomegalovirus (CMV) after birth and seroprevalence of anti-CMV IgG in Chinese children

    OpenAIRE

    Chen, Jie; Hu, Lingqing; Wu, Meiling; Zhong, Tianying; Zhou, Yi-Hua; Hu, Yali

    2012-01-01

    Abstract Background Prevalence of cytomegalovirus (CMV) infection is 90–100% in developing countries; however, the kinetics of anti-CMV IgG in infants remains elusive. Methods Sera from 112 mother-newborn pairs and longitudinal samples from 41 infants up to 2-year old were tested for anti-CMV IgG and IgM. Additionally, samples from 837 healthy children were included. Results Of 112 mothers, 108 (96.4%) were anti-CMV IgG positive; their 108 newborns were also seropositive. In a 2-year follow-u...

  4. Development of a solid-phase radioimmunoassay for antibody to antigens of Babesia bovis infected bovine erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kahl, L.P.; Anders, R.F.; Mitchell, G.F. (Walter and Eliza Hall Inst. of Medical Research, Parkville (Australia)); Callow, L.L.; Rodwell, B.J. (Animal Research Inst. Wacol (Australia). Tick Fever Research Centre)

    1982-06-01

    A quantitative solid-phase radioimmunoassay (RIA) has been developed for the purpose of ranking sera from exposed animals according to their titre of anti-B. bovis antibody. The antigen was a sonicate of lysed infected blood cells, and antibody binding was detected with /sup 125/I-labelled anti-bovine IgG. The assay was tested using sera from experimentally infected splenectomized and intact cattle and from animals resident in an endemic area. A high specificity for B. bovis was demonstrated. There was good agreement in identifying exposed cattle when the test was compared with an indirect fluorescent antibody (IFA) test although no correlation was seen between titres obtained in the two tests. Analysis of the effects of challenge infection with B. bovis on IFA and RIA titres in previously exposed animals illustrated that the RIA was a more sensitive test for detecting changes in antibody titre.

  5. Targeting the CXCR4 pathway using a novel anti-CXCR4 IgG1 antibody (PF-06747143 in chronic lymphocytic leukemia

    Directory of Open Access Journals (Sweden)

    Manoj K. Kashyap

    2017-05-01

    Full Text Available Abstract Background The CXCR4-CXCL12 axis plays an important role in the chronic lymphocytic leukemia (CLL-microenvironment interaction. Overexpression of CXCR4 has been reported in different hematological malignancies including CLL. Binding of the pro-survival chemokine CXCL12 with its cognate receptor CXCR4 induces cell migration. CXCL12/CXCR4 signaling axis promotes cell survival and proliferation and may contribute to the tropism of leukemia cells towards lymphoid tissues and bone marrow. Therefore, we hypothesized that targeting CXCR4 with an IgG1 antibody, PF-06747143, may constitute an effective therapeutic approach for CLL. Methods Patient-derived primary CLL-B cells were assessed for cytotoxicity in an in vitro model of CLL microenvironment. PF-06747143 was analyzed for cell death induction and for its potential to interfere with the chemokine CXCL12-induced mechanisms, including migration and F-actin polymerization. PF-06747143 in vivo efficacy was determined in a CLL murine xenograft tumor model. Results PF-06747143, a novel-humanized IgG1 CXCR4 antagonist antibody, induced cell death of patient-derived primary CLL-B cells, in presence or absence of stromal cells. Moreover, cell death induction by the antibody was independent of CLL high-risk prognostic markers. The cell death mechanism was dependent on CXCR4 expression, required antibody bivalency, involved reactive oxygen species production, and did not require caspase activation, all characteristics reminiscent of programmed cell death (PCD. PF-06747143 also induced potent B-CLL cytotoxicity via Fc-driven antibody-dependent cell-mediated cytotoxicity (ADCC and complement-dependent cytotoxicity activity (CDC. PF-06747143 had significant combinatorial effect with standard of care (SOC agents in B-CLL treatment, including rituximab, fludarabine (F-ara-A, ibrutinib, and bendamustine. In a CLL xenograft model, PF-06747143 decreased tumor burden and improved survival as a monotherapy

  6. A toolbox of anti–mouse and anti–rabbit IgG secondary nanobodies

    Science.gov (United States)

    2018-01-01

    Polyclonal anti–immunoglobulin G (anti-IgG) secondary antibodies are essential tools for many molecular biology techniques and diagnostic tests. Their animal-based production is, however, a major ethical problem. Here, we introduce a sustainable alternative, namely nanobodies against all mouse IgG subclasses and rabbit IgG. They can be produced at large scale in Escherichia coli and could thus make secondary antibody production in animals obsolete. Their recombinant nature allows fusion with affinity tags or reporter enzymes as well as efficient maleimide chemistry for fluorophore coupling. We demonstrate their superior performance in Western blotting, in both peroxidase- and fluorophore-linked form. Their site-specific labeling with multiple fluorophores creates bright imaging reagents for confocal and superresolution microscopy with much smaller label displacement than traditional secondary antibodies. They also enable simpler and faster immunostaining protocols, and allow multitarget localization with primary IgGs from the same species and of the same class. PMID:29263082

  7. Lol p I-specific IgE and IgG synthesis by peripheral blood mononuclear cells from atopic subjects in SCID mice.

    Science.gov (United States)

    Gagnon, R; Boutin, Y; Hébert, J

    1995-06-01

    The development of an animal model representative of the in vivo situation of human atopic diseases is always of interest for a better understanding of IgE production and regulation. Along these lines, mice with severe combined immunodeficiency (SCID mice) engrafted with lymphocytes from atopic subjects might be a suitable model for such studies. This study aims to analyze the production of Lol p I-specific IgE and IgG antibodies in SCID mice after transplantation of human peripheral blood mononuclear cells from atopic patients sensitive to grass pollens and from nonatopic donors. Peripheral blood mononuclear cells were transplanted into SCID mice, which were then challenged with Lol p I, and antibody responses (IgG and IgE) were analyzed over a 6-week period. Total IgG antibody was measured in each mouse serum after transplantation. Also, most mice (regardless of whether donors were atopic) that were challenged with Lol p I produced specific IgG antibody. Total IgE antibody production was observed only in mice grafted with cells from atopic patients. Lol p I-specific IgE antibodies were also produced after immunization with Lol p I. Although IgG antibody/response tended to plateau, the IgE antibody response increased until it peaked and declined thereafter. Interferon-gamma was detected in sera from mice producing IgE antibody, which supports a possible role of interferon-gamma in the decrease of IgE response. This study suggests that the SCID mouse model could represent an interesting approach to studying specific, total IgG and IgE antibody production, and ultimately their regulation.

  8. The quantitation of parasite-specific human IgG and IgE in sera: evaluation of solid-phase RIA and ELISA methodology

    International Nuclear Information System (INIS)

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

    1981-01-01

    The authors have developed a non-competitive solid-phase radioimmunoassay (SPRIA) to quantitate both human IgE and IgG antibodies against soluble adult antigens of Brugia malayi (B.m.), a filarial parasite causing extensive infection throughout the tropics. Previously enzyme-linked immunosorbent assays (ELISA) had been used to detect μg/ml levels of IgG anti-B.m., but IgE antibodies were difficult to detect in this system. Since the SPRIA successfully quantitates both IgG and IgE anti-B.m., they sought to examine the reasons for the SPRIA's apparent superiority in detecting IgE anti-B.m. by extracting specific IgG from sera with high levels of IgE and IgG anti-B.m. antibodies. IgE anti-B.m. was then quantitated in these sera using both the SPRIA and ELISA methods. Results indicate that IgG anti-B.m. does not interfere with detection of specific IgE antibody in the SPRIA but does interfere in the ELISA. While ELISA permits detection of IgE anti-B.m. in the absence of competing IgG anti-B.m., as levels of specific IgG increase, the IgE is no longer detectable. These differences between SPRIA and ELISA can be explained by the SPRIA's antigen excess conditions which assure that there are sufficient antigens both to detect all anti-B.m. antibodies present in the serum and to adequately represent all antigen specificities in the crude B.m. extract. Their findings commend the use of SPRIA methods over ELISA in assessment of B.m.-specific IgE antibody in filariasis and indicate a potential role for SPRIA methods in absolute quantitation of specific serum antibodies. (Auth.)

  9. Thrombus imaging with indium-111 and iodine-131-labeled fibrin-specific monoclonal antibody and its F(ab')2 and Fab fragments

    International Nuclear Information System (INIS)

    Rosebrough, S.F.; Grossman, Z.D.; McAfee, J.G.

    1988-01-01

    We have previously reported successful imaging of fresh (2-4 hr old) and aged (1-5 days old) canine thrombi with 131 I-labeled intact monoclonal antibody (MAb) specific for fibrin. We now report thrombus imaging with 131 I-labeled F(ab')2 and Fab and 111 In-labeled intact MAb, F(ab')2, and Fab. Indium-111-labeled F(ab')2 proved to be the best imaging agent due to less nonspecific binding in the liver than whole IgG. Image quality was improved by the higher administered dose permissible with 111 In and its better physical characteristics for imaging, compared to 131 I. Immunofluorescence of fresh human histologic sections showed intact MAb and F(ab')2 binding to thrombi, pulmonary emboli, and atherosclerotic plaques, strengthening the feasibility of clinical thrombus imaging

  10. GAMBARAN IgG4 dan IgE TERHADAP PROTEIN MIKROFILARIA PADA SERA PENDUDUK ENDEMIS FILARIASIS DI KECAMATAN PASIR PENYU, RIAU

    Directory of Open Access Journals (Sweden)

    Basundari SU

    2012-09-01

    Full Text Available Western blot test to detect specific IgG4 and IgE was performed to 12 microfilaraemic and 13 amicrofilaraemic individuals from malayan filariasis endemic area, Pasir Penyu, Riau. No differences in binding patterns of IgG4 and IgE antibodies to microfUarial protein components was shown. There was a parallel protein components recognition by IgG4 and IgE of molecular weight ranging from 158 kd to 14 kd. Protein component of 125 kd was only recognized by IgG4 and of 112 kd only by IgE. These findings suggest that in filarial infection IgG4 antibodies play a role as a blocking antibodies to inhibit the spesific reaction of IgE that is usually expressed as an allergic reaction.

  11. Anti-Taenia solium metacestode IgG antibodies in serum samples from inhabitants of a central-western region of Brazil

    Directory of Open Access Journals (Sweden)

    Oliveira Heliana B. de

    2006-01-01

    Full Text Available A total of 354 serum samples from inhabitants who frequent the Clinical Laboratory in Catalão, Goiás, in the central-western region of Brazil, were collected from June to August, 2002. The samples were evaluated by indirect immunofluorescence antibody tests and an enzyme linked immunosorbent assay in order to detect anti-Taenia solium metacestode IgG antibodies. Reactive and inconclusive samples were tested by Western blotting (WB. Considering WB as a confirmation, the frequency of antibodies in the serum samples of the above population was 11.3% (CI 5.09 - 17.51. The immunodominant bands most frequently recognized in WB were 64-68 kDa (97.5% and 47-52 kDa (80%. The percentage of seropositivity to cysticercosis was significantly higher for individuals residing in areas without sewage systems (p < 0.0001. In conclusion, the results indicate a probable endemic situation of cysticercosis in this population. These results reinforce the urgent need for control and prevention measures to be taken by the local public health services.

  12. Bone marrow dosimetry in rats using direct tissue counting after injection of radio-iodinated intact monoclonal antibodies or F(ab')2 fragments

    International Nuclear Information System (INIS)

    Buchegger, F.; Chalandon, Y.; Pelegrin, A.; Hardman, N.; Mach, J.P.

    1991-01-01

    Normal rats were injected intravenously with 131I- and 125I-labeled intact murine and chimeric mouse-human monoclonal antibodies directed against carcinoembryonic antigen or with the corresponding F(ab')2 fragments. At different times after injection, individual animals were killed and radioactivity of blood and major organs, including bones and bone marrow, was determined. Ratios comparing radioactivity concentration in different tissues with that of bone marrow were calculated and found to remain stable during several effective half-lives of the antibodies. Mean bone marrow radioactivity was 35% (range, 29%-40%) of that of blood and 126% (range, 108%-147%) of that of liver after injection of intact Mabs or F(ab')2 fragments. In nude rats bearing human colon carcinoma xenografts producing carcinoembryonic antigen, relative bone marrow radioactivity was slightly lower than that in normal rats

  13. Antibodies against Food Antigens in Patients with Autistic Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Laura de Magistris

    2013-01-01

    Full Text Available Purpose. Immune system of some autistic patients could be abnormally triggered by gluten/casein assumption. The prevalence of antibodies to gliadin and milk proteins in autistic children with paired/impaired intestinal permeability and under dietary regimen either regular or restricted is reported. Methods. 162 ASDs and 44 healthy children were investigated for intestinal permeability, tissue-transglutaminase (tTG, anti-endomysium antibodies (EMA-IgA, and total mucosal IgA to exclude celiac disease; HLA-DQ2/-DQ8 haplotypes; total systemic antibodies (IgA, IgG, and IgE; specific systemic antibodies: α-gliadin (AGA-IgA and IgG, deamidated–gliadin-peptide (DGP-IgA and IgG, total specific gliadin IgG (all fractions: α, β, γ, and ω, β-lactoglobulin IgG, α-lactalbumin IgG, casein IgG; and milk IgE, casein IgE, gluten IgE, -lactoglobulin IgE, and α-lactalbumin IgE. Results. AGA-IgG and DPG-IgG titers resulted to be higher in ASDs compared to controls and are only partially influenced by diet regimen. Casein IgG titers resulted to be more frequently and significantly higher in ASDs than in controls. Intestinal permeability was increased in 25.6% of ASDs compared to 2.3% of healthy children. Systemic antibodies production was not influenced by paired/impaired intestinal permeability. Conclusions. Immune system of a subgroup of ASDs is triggered by gluten and casein; this could be related either to AGA, DPG, and Casein IgG elevated production or to impaired intestinal barrier function.

  14. Potential of Murine IgG1 and Human IgG4 to Inhibit the Classical Complement and Fcγ Receptor Activation Pathways

    Directory of Open Access Journals (Sweden)

    Gina-Maria Lilienthal

    2018-05-01

    Full Text Available IgG antibodies (Abs mediate their effector functions through the interaction with Fcγ receptors (FcγRs and the complement factors. The main IgG-mediated complement activation pathway is induced through the binding of complement C1q to IgG Abs. This interaction is dependent on antigen-dependent hexamer formation of human IgG1 and IgG3 to increase the affinity for the six-headed C1q molecule. By contrast, human IgG4 fails to bind to C1q. Instead, it has been suggested that human IgG4 can block IgG1 and IgG3 hexamerization required for their binding to C1q and activating the complement. Here, we show that murine IgG1, which functionally resembles human IgG4 by not interacting with C1q, inhibits the binding of IgG2a, IgG2b, and IgG3 to C1q in vitro, and suppresses IgG2a-mediated complement activation in a hemolytic assay in an antigen-dependent and IgG subclass-specific manner. From this perspective, we discuss the potential of murine IgG1 and human IgG4 to block the complement activation as well as suppressive effects of sialylated IgG subclass Abs on FcγR-mediated immune cell activation. Accumulating evidence suggests that both mechanisms seem to be responsible for preventing uncontrolled IgG (autoAb-induced inflammation in mice and humans. Distinct IgG subclass distributions and functionally opposite IgG Fc glycosylation patterns might explain different outcomes of IgG-mediated immune responses and provide new therapeutic options through the induction, enrichment, or application of antigen-specific sialylated human IgG4 to prevent complement and FcγR activation as well.

  15. Early diagnosis of congenital toxoplasmosis in newborn infants using IgG subclasses against two Toxoplasma gondii recombinant proteins

    Directory of Open Access Journals (Sweden)

    Carlos Henryque de Souza e Silva

    2012-05-01

    Full Text Available The aim of this work was to evaluate the utility of ELISA-based testing of total IgG (IgGt antibodies and its subclasses (IgG1, IgG2, IgG3 and IgG4 against soluble (STAg and recombinant (rSAG1 and rMIC3 antigens of Toxoplasma gondii for diagnosing congenital toxoplasmosis. Sera from 217 newborns initially testing positive for specific IgM in filter paper dried blood spots were tested for specific IgM and IgG by ELFA-VIDAS®. Congenital toxoplasmosis was confirmed in 175 and ruled out in 42 infants. The validity of the ELISA tests was determined using the persistence of IgG antibodies (ELFA-VIDAS® kit at the end of 12 months, which is considered the reference test for the diagnosis of congenital toxoplasmosis. The frequency of positivity with IgGt against STAg, rSAG1 and rMIC3 was found in 97.2%, 96.3% and 80.2%, respectively, of the newborns with confirmed congenital toxoplasmosis. IgG1 reacted with all three antigens, while IgG3 and IgG4 reacted preferentially with rMIC3. Higher mean values of reactivity (sample optical density/cut-off were found for all subclasses when using rMIC3. All of the antigens showed high sensitivity and low specificity in detecting anti-T. gondii IgGt and IgG1 and low sensitivity and high specificity in detecting IgG3 and IgG4. In conclusion, the combined detection of IgG antibody subclasses against recombinant toxoplasmic antigens may be useful for the early diagnosis of congenital toxoplasmosis.

  16. Secondary IgG responses to type III pneumococcal polysaccharide. II. Different cellular requirements for induction and elicitation.

    Science.gov (United States)

    Braley-Mullen, H

    1976-04-01

    Mice primed with a thymus- (T) dependent form of Type III pneumococcal polysaccharide (S3), i.e., S3 coupled to erythrocytes (S3-RBC) produce S3-specific IgG antibody after secondary challenge with either S3 or S3-RBC. The production of IgG antibody by mice challenged with S3 was shown to be T independent since secondary responses were enhanced when mice were treated with anti-lymphocyte serum (ALS) at the time of secondary challenge with S3 and T-depleted spleen cells responded as well as unfractionated spleen cells to S3 in an adoptive transfer system. Secondary S3-specific IgG responses in mice challenged with S3-RBC were shown to be T dependent by the same criteria. The results obtained by using S3 as the antigen indicate that IgG-producing B cells (B lambda cells) can recognize and respond to antigen in the absence of helper T cells. On the other hand, T cells were required for the induction of S3-specific memory B lambda cells since mice depleted of T cells by treatment with ALS at the time of priming with S3-RBC failed to produce S3-specific IgG antibody after secondary challenge with either S3-specific IgG antibody after secondary chall-nge with either S3 or S3rbc. Since RBC-specific memory cells were induced in T-deprived mice the results suggest that T cell regulation of IgG antibody production may vary for different antigens.

  17. Estimation of antibodies to human cytomegalovirus by immunofluorescence and radioimmunoassay

    International Nuclear Information System (INIS)

    Jankowski, M.; Gut, W.; Nawrocka, E.

    1980-01-01

    The 125 I labelled IgG fraction against rabbit IgG of goat origin was employed for the detection of CMV IgG and IgM antibodies in the double indirect radioimmunoassay. The results were compared with those obtained in complement fixation, indirect immunofluorescence and anti-complement immunofluorescence tests. The application of labelled anti-fc antisera, instead of antisera against whole IgG in the tests for detection of specific CMV IgG antibody resulted in increased sensitivity of radioimmunoassay and reduction of non-specific cytoplasmatic reactions in preparations stained by indirect immunofluorescence. The absorption of sera with protein A rich staphylococci and aggregates to immunoglobulin eliminated unwanted secondary IgM staining caused by rheumatoid factors both in indirect immunofluorescence and radioimmunoassay tests for CMV antibodies. (author)

  18. Immunodominant IgM and IgG Epitopes Recognized by Antibodies Induced in Enterovirus A71-Associated Hand, Foot and Mouth Disease Patients.

    Directory of Open Access Journals (Sweden)

    Kam Leng Aw-Yong

    Full Text Available Enterovirus A71 (EV-A71 is one of the main causative agents of hand, foot and mouth disease (HFMD. Unlike other enteroviruses that cause HFMD, EV-A71 is more frequently associated with severe neurological complications and fatality. To date, no effective licensed antivirals are available to combat EV-A71 infection. Little is known about the immunogenicity of viral non-structural proteins in humans. Previous studies have mainly focused on characterization of epitopes of EV-A71 structural proteins by using immunized animal antisera. In this study, we have characterized human antibody responses against the structural and non-structural proteins of EV-A71. Each viral protein was cloned and expressed in either bacterial or mammalian systems, and tested with antisera by western blot. Results revealed that all structural proteins (VP1-4, and non-structural proteins 2A, 3C and 3D were targets of EV-A71 IgM, whereas EV-A71 IgG recognized all the structural and non-structural proteins. Sixty three synthetic peptides predicted to be immunogenic in silico were synthesized and used for the characterization of EV-A71 linear B-cell epitopes. In total, we identified 22 IgM and four IgG dominant epitopes. Synthetic peptide PEP27, corresponding to residues 142-156 of VP1, was identified as the EV-A71 IgM-specific immunodominant epitope. PEP23, mapped to VP1 41-55, was recognized as the EV-A71 IgG cross-reactive immunodominant epitope. The structural protein VP1 is the major immunodominant site targeted by anti-EV-A71 IgM and IgG antibodies, but epitopes against non-structural proteins were also detected. These data provide new understanding of the immune response to EV-A71 infection, which benefits the development of diagnostic tools, potential therapeutics and subunit vaccine candidates.

  19. Quantitative analysis of the IgG and IgG subclass immune responses to chromosomal Pseudomonas aeruginosa beta-lactamase in serum from patients with cystic fibrosis by western blotting and laser scanning densitometry

    DEFF Research Database (Denmark)

    Petersen, T D; Ciofu, O; Pressler, T

    1996-01-01

    BACKGROUND: Antibodies against chromosomal beta-lactamase of Pseudomonas aeruginosa (a beta ab) are markers of the development of resistance of P aeruginosa to beta-lactam antibiotics in patients with cystic fibrosis and chronic lung infection. The role of these antibodies in patients with chronic...... of the chronic infection the a beta ab titres were higher in patients with good lung function than in those with poor lung function. CONCLUSIONS: The association of a weak IgG3 and a strong IgG4 a beta ab response suggests that the contribution of a beta ab antibodies to lung diseases mediated by immune...... complexes might be less important than other antipseudomonal antibodies. A beneficial neutralising effect of the a beta ab antibodies on the antibiotic destroying enzymes may be an additional factor....

  20. Antineutrophil cytoplasmic antibody-associated vasculitides and IgG4-related disease: A new overlap syndrome.

    Science.gov (United States)

    Danlos, François-Xavier; Rossi, Giovanni Maria; Blockmans, Daniel; Emmi, Giacomo; Kronbichler, Andreas; Durupt, Stéphane; Maynard, Claire; Luca, Luminita; Garrouste, Cyril; Lioger, Bertrand; Mourot-Cottet, Rachel; Dhote, Robin; Arlet, Jean-Benoit; Hanslik, Thomas; Rouvier, Philippe; Ebbo, Mikael; Puéchal, Xavier; Nochy, Dominique; Carlotti, Agnès; Mouthon, Luc; Guillevin, Loïc; Vaglio, Augusto; Terrier, Benjamin

    2017-10-01

    Atypical manifestations have been described in patients with ANCA-associated vasculitides (AAV), such as pachymeningitis, orbital mass or chronic periaortitis. Because these manifestations have been associated to the spectrum of IgG4-related disease (IgG4-RD), we hypothesized that both diseases could overlap. We conducted a European retrospective multicenter observational study including patients fulfilling ACR and Chapel Hill criteria for AAV and IgG4-RD Comprehensive Diagnostic Criteria. Eighteen patients were included (median age 55.5years, 13 men). AAV and IgG4-RD were diagnosed concomitantly in 13/18 (72%) patients; AAV preceded IgG4-RD in 3/18 (17%) while IgG4-RD preceded AAV in 2/18 (11%). AAV diagnoses included granulomatosis with polyangiitis in 14 (78%), microscopic polyangiitis in 3 (17%), and eosinophilic granulomatosis with polyangiitis in one case. IgG4-RD diagnosis included definite IgG4-RD in 5 (28%) cases, probable IgG4-RD in 5 (28%) and possible IgG4-RD in 8 (44%). IgG4-RD manifestations were chronic periaortitis in 9/18 (50%) patients, orbital mass and tubulointerstitial nephritis in 4 (22%) cases, prevertebral fibrosis in 3 (17%), pachymeningitis and autoimmune pancreatitis in 2 (11%) cases. Patients required median number of 2 (range 0-4) lines of immunosuppressants in combination with glucocorticoids. During the follow-up (median 49,8months, range 17,25-108months), AAV manifestations relapsed in 10/18 (56%) cases and IgG4-RD lesions in 5/18 (28%). When used, mainly for relapses, rituximab showed response in all cases. AAV and IgG4-RD may overlap. Clinicians should consider that atypical manifestations during AAV could be related to IgG4-RD rather than to refractory granulomatous or vasculitic lesions. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Igg Subclasses Targeting the Flagella of Salmonella enterica Serovar Typhimurium Can Mediate Phagocytosis and Bacterial Killing

    Science.gov (United States)

    Goh, Yun Shan; Armour, Kathryn L; Clark, Michael R; Grant, Andrew J; Mastroeni, Pietro

    2016-01-01

    Invasive non-typhoidal Salmonella are a common cause of invasive disease in immuno-compromised individuals and in children. Multi-drug resistance poses challenges to disease control, with a critical need for effective vaccines. Flagellin is an attractive vaccine candidate due to surface exposure and high epitope copy number, but its potential as a target for opsonophacytic antibodies is unclear. We examined the effect of targeting flagella with different classes of IgG on the interaction between Salmonella Typhimurium and a human phagocyte-like cell line, THP-1. We tagged the FliC flagellar protein with a foreign CD52 mimotope (TSSPSAD) and bacteria were opsonized with a panel of humanised CD52 antibodies with the same antigen-binding V-region, but different constant regions. We found that IgG binding to flagella increases bacterial phagocytosis and reduces viable intracellular bacterial numbers. Opsonisation with IgG3, followed by IgG1, IgG4, and IgG2, resulted in the highest level of bacterial uptake and in the highest reduction in the intracellular load of viable bacteria. Taken together, our data provide proof-of-principle evidence that targeting flagella with antibodies can increase the antibacterial function of host cells, with IgG3 being the most potent subclass. These data will assist the rational design of urgently needed, optimised vaccines against iNTS disease. PMID:27366588

  2. Structural and immunological characterization of hydroxyl radical modified human IgG: Clinical correlation in rheumatoid arthritis

    Science.gov (United States)

    Islam, Sidra; Mir, Abdul Rouf; Arfat, Mir Yasir; Khan, Farzana; Zaman, Masihuz; Ali, Asif; Moinuddin

    2018-04-01

    Structural alterations in proteins under oxidative stress have been widely implicated in the immuno-pathology of various disorders. This study has evaluated the extent of damage in the conformational characteristics of IgG by hydroxyl radical (OHrad) and studied its implications in the immuno-pathology of rheumatoid arthritis (RA). Using various biophysical and biochemical techniques, changes in aromatic microenvironment of the IgG and the protein aggregation became evident after treatment with OHrad . The SDS-PAGE study confirmed the protein aggregation while far ultraviolet circular dichroism spectroscopy (Far-UV CD) and fourier transform infrared spectroscopy (FTIR) inferred towards the alterations in secondary structure of IgG under OHrad stress. Dynamic light scattering showed that the modification increased the hydrodynamic radius and polydispersity of IgG. The free arginine and lysine content reduced upon modification. OHrad induced aggregation was confirmed by enhanced thioflavin-T (ThT) fluorescence and red shift in the congo red (CR) absorbance. The study on experimental animals reiterates the earlier findings of enhanced immunogenicity of OHrad treated IgG (OHrad -IgG) compared to that of native IgG. OHrad -IgG strongly interacted with the antibodies derived from the serum of 80 rheumatoid arthritis (RA) patients. The overwhelming and strong tendency of OHrad -IgG to bind the antibodies derived from the serum of RA patients points towards the modification of IgG under patho-physiological conditions in RA that generate neo-epitopes and eventually cause the generation of auto antibodies that circulate in the patient sera. Further studies on this aspect may possibly lead to the development of a biomarker for RA.

  3. Radioimmunoassay of class-specific antibodies (RIACA): chicken antibodies to DNP

    International Nuclear Information System (INIS)

    Viljanen, M.K.; Granfors, K.; Toivanen, P.

    1977-01-01

    A radioimmunological method for the quantitation of class-specific antibodies has been developed. The method allows the quantitation of nanogram per ml concentrations of IgG and IgM-anti-DNP antibodies without any physical or chemical pretreatment of the sample. DNP was coupled covalently to a cyanogen bromide activated paper disk with the augmentation of lysine molecule. Anti-DNP antibodies were allowed to react with the coupled DNP and then quantitated by their capacity to bind 125 I-labelled anti-chicken-μ or anti-chicken-γ. The inter-assay variation coefficients ranged from 8.1 to 14.7% and the mean standard deviations of duplicate determinations were about 11%. The combination of this method with the exact immunoradiometric quantitation of the total serum IgM and IgG, and with an immunoabsorption technique, makes it possible to quantitate class-specific antibodies on weight units

  4. A shark antibody heavy chain encoded by a nonsomatically rearranged VDJ is preferentially expressed in early development and is convergent with mammalian IgG.

    Science.gov (United States)

    Rumfelt, L L; Avila, D; Diaz, M; Bartl, S; McKinney, E C; Flajnik, M F

    2001-02-13

    In most vertebrate embryos and neonates studied to date unique antigen receptors (antibodies and T cell receptors) are expressed that possess a limited immune repertoire. We have isolated a subclass of IgM, IgM(1gj), from the nurse shark Ginglymostoma cirratum that is preferentially expressed in neonates. The variable (V) region gene encoding the heavy (H) chain underwent V-D-J rearrangement in germ cells ("germline-joined"). Such H chain V genes were discovered over 10 years ago in sharks but until now were not shown to be expressed at appreciable levels; we find expression of H(1gj) in primary and secondary lymphoid tissues early in life, but in adults only in primary lymphoid tissue, which is identified in this work as the epigonal organ. H(1gj) chain associates covalently with light (L) chains and is most similar in sequence to IgM H chains, but like mammalian IgG has three rather than the four IgM constant domains; deletion of the ancestral IgM C2 domain thus defines both IgG and IgM(1gj). Because sharks are the members of the oldest vertebrate class known to possess antibodies, unique or specialized antibodies expressed early in ontogeny in sharks and other vertebrates were likely present at the inception of the adaptive immune system.

  5. Cloning of pCDNA3-IgG4 and pQE-2-IgG4 human hinge region ...

    African Journals Online (AJOL)

    GREGORY

    2011-12-16

    Dec 16, 2011 ... diseases and in allergy-related immunoassays, thus, anti-hIgG4 antibody is of interest in the development of ... pQE-2-. IgG4 will be used for protein expression in M15 prokaryotic .... Solution conformation of wild-type and ...

  6. Glycoengineered Monoclonal Antibodies with Homogeneous Glycan (M3, G0, G2, and A2) Using a Chemoenzymatic Approach Have Different Affinities for FcγRIIIa and Variable Antibody-Dependent Cellular Cytotoxicity Activities.

    Science.gov (United States)

    Kurogochi, Masaki; Mori, Masako; Osumi, Kenji; Tojino, Mami; Sugawara, Shu-Ichi; Takashima, Shou; Hirose, Yuriko; Tsukimura, Wataru; Mizuno, Mamoru; Amano, Junko; Matsuda, Akio; Tomita, Masahiro; Takayanagi, Atsushi; Shoda, Shin-Ichiro; Shirai, Takashi

    2015-01-01

    Many therapeutic antibodies have been developed, and IgG antibodies have been extensively generated in various cell expression systems. IgG antibodies contain N-glycans at the constant region of the heavy chain (Fc domain), and their N-glycosylation patterns differ during various processes or among cell expression systems. The Fc N-glycan can modulate the effector functions of IgG antibodies, such as antibody-dependent cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC). To control Fc N-glycans, we performed a rearrangement of Fc N-glycans from a heterogeneous N-glycosylation pattern to homogeneous N-glycans using chemoenzymatic approaches with two types of endo-β-N-acetyl glucosaminidases (ENG'ases), one that works as a hydrolase to cleave all heterogeneous N-glycans, another that is used as a glycosynthase to generate homogeneous N-glycans. As starting materials, we used an anti-Her2 antibody produced in transgenic silkworm cocoon, which consists of non-fucosylated pauci-mannose type (Man2-3GlcNAc2), high-mannose type (Man4-9GlcNAc2), and complex type (Man3GlcNAc3-4) N-glycans. As a result of the cleavage of several ENG'ases (endoS, endoM, endoD, endoH, and endoLL), the heterogeneous glycans on antibodies were fully transformed into homogeneous-GlcNAc by a combination of endoS, endoD, and endoLL. Next, the desired N-glycans (M3; Man3GlcNAc1, G0; GlcNAc2Man3GlcNAc1, G2; Gal2GlcNAc2Man3GlcNAc1, A2; NeuAc2Gal2GlcNAc2Man3GlcNAc1) were transferred from the corresponding oxazolines to the GlcNAc residue on the intact anti-Her2 antibody with an ENG'ase mutant (endoS-D233Q), and the glycoengineered anti-Her2 antibody was obtained. The binding assay of anti-Her2 antibody with homogenous N-glycans with FcγRIIIa-V158 showed that the glycoform influenced the affinity for FcγRIIIa-V158. In addition, the ADCC assay for the glycoengineered anti-Her2 antibody (mAb-M3, mAb-G0, mAb-G2, and mAb-A2) was performed using SKBR-3 and BT-474 as target cells, and

  7. Glycoengineered Monoclonal Antibodies with Homogeneous Glycan (M3, G0, G2, and A2 Using a Chemoenzymatic Approach Have Different Affinities for FcγRIIIa and Variable Antibody-Dependent Cellular Cytotoxicity Activities.

    Directory of Open Access Journals (Sweden)

    Masaki Kurogochi

    Full Text Available Many therapeutic antibodies have been developed, and IgG antibodies have been extensively generated in various cell expression systems. IgG antibodies contain N-glycans at the constant region of the heavy chain (Fc domain, and their N-glycosylation patterns differ during various processes or among cell expression systems. The Fc N-glycan can modulate the effector functions of IgG antibodies, such as antibody-dependent cellular cytotoxicity (ADCC and complement dependent cytotoxicity (CDC. To control Fc N-glycans, we performed a rearrangement of Fc N-glycans from a heterogeneous N-glycosylation pattern to homogeneous N-glycans using chemoenzymatic approaches with two types of endo-β-N-acetyl glucosaminidases (ENG'ases, one that works as a hydrolase to cleave all heterogeneous N-glycans, another that is used as a glycosynthase to generate homogeneous N-glycans. As starting materials, we used an anti-Her2 antibody produced in transgenic silkworm cocoon, which consists of non-fucosylated pauci-mannose type (Man2-3GlcNAc2, high-mannose type (Man4-9GlcNAc2, and complex type (Man3GlcNAc3-4 N-glycans. As a result of the cleavage of several ENG'ases (endoS, endoM, endoD, endoH, and endoLL, the heterogeneous glycans on antibodies were fully transformed into homogeneous-GlcNAc by a combination of endoS, endoD, and endoLL. Next, the desired N-glycans (M3; Man3GlcNAc1, G0; GlcNAc2Man3GlcNAc1, G2; Gal2GlcNAc2Man3GlcNAc1, A2; NeuAc2Gal2GlcNAc2Man3GlcNAc1 were transferred from the corresponding oxazolines to the GlcNAc residue on the intact anti-Her2 antibody with an ENG'ase mutant (endoS-D233Q, and the glycoengineered anti-Her2 antibody was obtained. The binding assay of anti-Her2 antibody with homogenous N-glycans with FcγRIIIa-V158 showed that the glycoform influenced the affinity for FcγRIIIa-V158. In addition, the ADCC assay for the glycoengineered anti-Her2 antibody (mAb-M3, mAb-G0, mAb-G2, and mAb-A2 was performed using SKBR-3 and BT-474 as target

  8. ORIGINAL ARTICLE RUBELLA IgG ANTIBODY AMONG NIGERIAN ...

    African Journals Online (AJOL)

    boaz

    capable of causing a spectrum of birth defects described as congenital rubella syndrome (CRS). Despite the availability of safe and effective ... designed to determine the prevalence of anti- rubella IgG among pregnant women in order to ..... Vyse A.J., Gay N.J., White J.M., Ramsay. M.E., Brown D.W., Cohen B.J. Evolution.

  9. 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

  10. Opsonization of Cryptococcus neoformans by a family of isotype-switch variant antibodies specific for the capsular polysaccharide.

    Science.gov (United States)

    Schlageter, A M; Kozel, T R

    1990-06-01

    A family of immunoglobulin isotype-switch variants was isolated by sib selection from a murine hybridoma which produced an immunoglobulin G subclass 1 (IgG1) antibody specific for the capsular polysaccharide of Cryptococcus neoformans. Antibodies of the IgG1, IgG2a, and IgG2b isotypes had similar serotype specificity patterns in double immunodiffusion assays which used polysaccharides of the four cryptococcal serotypes as antigens. A quantitative difference in the ability of the isotypes to form a precipitate with the polysaccharide was observed in a double immunodiffusion assay and confirmed in a quantitative precipitin assay. The relative precipitating activity of the antibodies was IgG2a greater than IgG1 much greater than IgG2b. Analysis by enzyme-linked immunosorbent assay of the reactivity of the three isotypes with cryptococcal polysaccharide showed identical titers and slopes, suggesting that the variable region of the class-switch antibodies was unaltered. This system allowed us to examine the effect of the Fc portion of the antibody on opsonization of encapsulated cryptococci. Yeast cells were precoated with antibodies of each isotype and incubated with murine macrophages or cultured human monocytes. Antibodies of all three isotypes exhibited a dose-dependent opsonization for phagocytosis by both human and murine phagocytes. The relative opsonic activity of the antibodies was IgG2a greater than IgG1 greater than IgG2b.

  11. Lysine conjugation properties in human IgGs studied by integrating high-resolution native mass spectrometry and bottom-up proteomics

    NARCIS (Netherlands)

    Gautier, Violette|info:eu-repo/dai/nl/372660851; Boumeester, Anja J.; Lössl, Philip|info:eu-repo/dai/nl/371559693; Heck, Albert J R|info:eu-repo/dai/nl/105189332

    2015-01-01

    Antibody-drug conjugates (ADCs) are a novel class of biopharmaceuticals several of which are now being investigated in clinical studies. In ADCs, potent cytotoxic drugs are coupled via a linker to reactive residues in IgG monoclonal antibodies. Linkage to lysine residues in the IgGs, using

  12. Purification of antibodies to bacterial antigens by an immunoadsorbent and a method to quantify their reaction with insoluble bacterial targets

    International Nuclear Information System (INIS)

    Mathews, H.L.; Minden, P.

    1979-01-01

    A combination of procedures was employed to develop a radioimmunoassay which quantified the binding of antibodies to antigens of either intact Propionibacterium acnes or to antigens of insoluble extracts derived from the bacteria. Reactive antibody populations were purified by use of bacterial immunoadsorbents which were prepared by coupling P. acnes to diethylaminoethyl cellulose. Binding of antibodies was detected with [ 125 I]staphylococcal protein A ([ 125 I]SpA) and optimal conditions for the assay defined by varying the amounts of antibodies, bacterial antigenic targets and [ 125 I]SpA. In antibody excess, 100% of available [ 125 I]SpA was bound by the target-antibody complexes. However, when antibody concentration was limiting, a linear relationship was demonstrated between per cent specific binding of[ 125 I]SpA and antibodies bound to bacterial targets. These results were achieved only with immunoadsorbent-purified antibody populations and not with hyperimmune sera or IgG. The radioimmunoassay detected subtle antigenic differences and similarities between P. acnes, P. acnes extracts and a variety of unrelated microorganisms. (Auth.)

  13. Localization of radioiodinated antibody to alpha-fetoprotein in rats with transplanted hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Koji, T; Ishii, N; Munehisa, T; Kusumoto, Y; Nakamura, S; Tamenishi, A [Nagasaki Univ. (Japan). School of Medicine; Kobayashi, K; Hara, A; Tsukada, Y; Nishi, S

    1980-01-01

    Total body scintigraphy, organ and subcellular distribution of radioactivity and autoradiography of tissue sections has been assessed in an animal model using radioiodinated horse antibody to rat alpha-fetoprotein (AFP). Rats bearing subcutaneous transplants of AH-7974 ascites hepatoma were injected with /sup 125/I-labeled anti-AFP and scintigraphed. Localization of radioactivity in the tumors was observed 48-168 h after injection. Scintigraphy using /sup 125/I-labeled F(ab')/sub 2/ fragment of the antibody gave approximately the same results as that with the intact anti-AFP antibody. /sup 125/I-labeled normal horse IgG was used as control. The tumor/blood radioactivity ratio after a week after injection was approximately four times higher in the antibody group than that in the control group. This ratio suggested an active accumulation of radioactive antibody in the tumor tissue. In its subcellular distribution, about 30 to 60% of the total radioactivity administered was found in a fraction of the cell membrane plus nucleus. The specific activity of this fraction increased in the antibody group with time over 10 days. In autoradiograms of the fixed tissue sections specific localization of the antibody was observed on the tumor cell surface. The specific uptake of radiolabeled antibody to AFP into AFP producing tumor cells was confirmed.

  14. Prohibitin Is Involved in Patients with IgG4 Related Disease.

    Directory of Open Access Journals (Sweden)

    Hongwu Du

    Full Text Available IgG4-related disease (IgG4-RD is a chronic systemic disease involved in many organs and tissues. As only limited autoantigens have been found since the beginning of this century, the aim of this study was to reveal new candidate autoantigens of IgG4-RD.Multiple cell lines including HT-29, EA.hy926, HEK 293 and HepG2 were used to test the binding ability of circulating autoantibodies from IgG4-RD sera. The amino-acid sequence was then analyzed by matrix-assisted laser desorption/ionization time-of-flight tandem (MALDI-TOF/TOF mass spectrometry. After the cloning and expression of recombinant putative autoantigen in a bacterial expression system, the corresponding immuno assay was set up and utilized to observe the prevalence of serum autoantibodies in a large set of confirmed clinical samples.One positive autoantigen was identified as prohibitin. ELISA analysis showed that a majority of patients with IgG4-RD have antibodies against prohibitin. Anti-prohibitin antibodies were present in the sera of patients with definite autoimmune pancreatitis (25/34; 73.5%, Mikulicz's disease (8/15; 53.3%, retroperitoneal fibrosis (6/11; 54.5%, other probable IgG4-RD (26/29; 89.7% and Sjögren's syndrome (4/30; 13.3% but not in apparently healthy donors (1/70; 1.4%.An association between prohibitin and patients with some IgG4-RD was observed, although the results were quite heterogeneous among different individuals within autoimmune pancreatitis, Mikulicz's disease and retroperitoneal fibrosis.

  15. Discovery and characterization of antibody variants using mass spectrometry-based comparative analysis for biosimilar candidates of monoclonal antibody drugs.

    Science.gov (United States)

    Li, Wenhua; Yang, Bin; Zhou, Dongmei; Xu, Jun; Ke, Zhi; Suen, Wen-Chen

    2016-07-01

    Liquid chromatography mass spectrometry (LC-MS) is the most commonly used technique for the characterization of antibody variants. MAb-X and mAb-Y are two approved IgG1 subtype monoclonal antibody drugs recombinantly produced in Chinese hamster ovary (CHO) cells. We report here that two unexpected and rare antibody variants have been discovered during cell culture process development of biosimilars for these two approved drugs through intact mass analysis. We then used comprehensive mass spectrometry-based comparative analysis including reduced light, heavy chains, and domain-specific mass as well as peptide mapping analysis to fully characterize the observed antibody variants. The "middle-up" mass comparative analysis demonstrated that the antibody variant from mAb-X biosimilar candidate was caused by mass variation of antibody crystalline fragment (Fc), whereas a different variant with mass variation in antibody antigen-binding fragment (Fab) from mAb-Y biosimilar candidate was identified. Endoproteinase Lys-C digested peptide mapping and tandem mass spectrometry analysis further revealed that a leucine to glutamine change in N-terminal 402 site of heavy chain was responsible for the generation of mAb-X antibody variant. Lys-C and trypsin coupled non-reduced and reduced peptide mapping comparative analysis showed that the formation of the light-heavy interchain trisulfide bond resulted in the mAb-Y antibody variant. These two cases confirmed that mass spectrometry-based comparative analysis plays a critical role for the characterization of monoclonal antibody variants, and biosimilar developers should start with a comprehensive structural assessment and comparative analysis to decrease the risk of the process development for biosimilars. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Labeling and stability of radiolabeled antibody fragments by a direct 99mTc-labeling method

    International Nuclear Information System (INIS)

    Pak, K.Y.; Nedelman, M.A.; Tam, S.H.; Wilson, E.; Daddona, P.E.

    1992-01-01

    The in vitro labeling and stability of 99m Tc-labeled antibody Fab' fragments prepared by a direct labeling technique were evaluated. Eight antibody fragments derived from murine IgG1 (N = 5), IgG2a (N = 2) and IgG3 (N = 1) isotypes were labeled with a preformed 99m Tc-D-glucarate complex. No loss of radioactivity incorporation was observed for all the 99m Tc-labeled antibody fragments after 24 h incubation at 37 o C. 99m Tc-labeled antibody fragments (IgG1, N = 2; IgG2a, n = 2; IgG3, N = 1) were stable upon challenge with DTPA, EDTA or acidic pH. Using the affinity chromatography technique, two of the 99m Tc-labeled antibody fragments displayed no loss of immunoreactivity after prolonged incubation in phosphate buffer up to 24 h at 37 o C. Bonding between 99m Tc and antibody fragments was elucidated by challenging with a diamide ditholate (N 2 S 2 ) compound. The Fab' with IgG2a isotype displayed tighter binding to 99m Tc in comparison to Fab' from IgG1 and IgG3 isotype in N 2 S 2 challenge and incubation with human plasma. The in vivo biodistribution of five 99m Tc-labeled fragments were evaluated in normal mice. (Author)

  17. IgA, IgE e subclasses de IgG anti-Candida albicans no soro e lavado vaginal de pacientes com candidíase vulvovaginal IgA, IgE and IgG subclasses to Candida albicans in serum and vaginal fluid from patients with vulvovaginal candidiasis

    Directory of Open Access Journals (Sweden)

    Ricardo José Victal de Carvalho

    2003-01-01

    Full Text Available OBJETIVO: Determinar níveis de anticorpos IgA, IgE, IgG e subclasses (IgG1, IgG4 específicos a C. albicans no soro e lavado vaginal de mulheres com ou sem candidíase vulvovaginal para avaliar o papel destes anticorpos na imunopatogênese desta doença. MÉTODOS: Foram selecionadas 30 mulheres com sintomas clínicos de candidíase vulvovaginal (15 com cultura de secreção vaginal positiva para C. albicans, 11 com cultura negativa e quatro com cultura positiva para Candida não-albicans e 12 mulheres controles assintomáticas (nove com cultura negativa. Amostras de soro e lavado vaginal foram obtidas para a detecção de anticorpos anti-C. albicans por ELISA. RESULTADOS: Pacientes sintomáticas com cultura positiva apresentaram níveis de IgA específicas significativamente maiores no lavado vaginal e menores no soro do que aquelas com cultura negativa. Níveis séricos de IgE específica foram extremamente baixos em relação ao lavado vaginal. Altos níveis de IgG total específica foram encontrados no soro e lavado vaginal em ambos os grupos, independente da presença do fungo. Níveis de IgG1 e IgG4 específicas foram significativamente maiores somente no lavado vaginal de mulheres sintomáticas e cultura positiva, com relação IgG1/IgG4 ligeiramente maior, indicando que a resposta de anticorpos IgG1 possa estar predominantemente envolvida na resolução da infecção fúngica. CONCLUSÕES: Nossos resultados indicam resposta acentuada de IgA, IgG1 e IgG4 anti-C. albicans no lavado vaginal de mulheres sintomáticas com cultura positiva, sugerindo importante papel destes anticorpos na resposta imune local estimulada pela presença do fungo.PURPOSE: To determine the levels of IgA, IgE, IgG and subclasses (IgG1, IgG4 antibodies specific to C. albicans in serum and vaginal washes from women with or without vulvovaginal candidiasis in order to evaluate the role of these antibodies in the immunopathogenesis of the disease. METHODS: Thirty women

  18. P. falciparum infection and maternofetal antibody transfer in malaria-endemic settings of varying transmission.

    Directory of Open Access Journals (Sweden)

    Alistair R D McLean

    Full Text Available During pregnancy, immunoglobulin G (IgG is transferred from the mother to the fetus, providing protection from disease in early infancy. Plasmodium falciparum infections may reduce maternofetal antibody transfer efficiency, but mechanisms remain unclear.Mother-cord paired serum samples collected at delivery from Papua New Guinea (PNG and the Thailand-Myanmar Border Area (TMBA were tested for IgG1 and IgG3 to four P. falciparum antigens and measles antigen, as well as total serum IgG. Multivariable linear regression was conducted to assess the association of peripheral P. falciparum infection during pregnancy or placental P. falciparum infection assessed at delivery with maternofetal antibody transfer efficiency. Path analysis assessed the extent to which associations between P. falciparum infection and antibody transfer were mediated by gestational age at delivery or levels of maternal total serum IgG.Maternofetal antibody transfer efficiency of IgG1 and IgG3 was lower in PNG compared to TMBA (mean difference in cord antibody levels (controlling for maternal antibody levels ranged from -0.88 to 0.09, median of -0.20 log2 units. Placental P. falciparum infections were associated with substantially lower maternofetal antibody transfer efficiency in PNG primigravid women (mean difference in cord antibody levels (controlling for maternal antibody levels ranged from -0.62 to -0.10, median of -0.36 log2 units, but not multigravid women. The lower antibody transfer efficiency amongst primigravid women with placental infection was only partially mediated by gestational age at delivery (proportion indirect effect ranged from 0% to 18%, whereas no mediation effects of maternal total serum IgG were observed.Primigravid women may be at risk of impaired maternofetal antibody transport with placental P. falciparum infection. Direct effects of P. falciparum on the placenta, rather than earlier gestational age and elevated serum IgG, are likely responsible for

  19. Quantification of anti-Leishmania antibodies in saliva of dogs.

    Science.gov (United States)

    Cantos-Barreda, Ana; Escribano, Damián; Bernal, Luis J; Cerón, José J; Martínez-Subiela, Silvia

    2017-08-15

    Detection of serum anti-Leishmania antibodies by quantitative or qualitative techniques has been the most used method to diagnose Canine Leishmaniosis (CanL). Nevertheless, saliva may represent an alternative to blood because it is easy to collect, painless and non-invasive in comparison with serum. In this study, two time-resolved immunofluorometric assays (TR-IFMAs) for quantification of anti-Leishmania IgG2 and IgA antibodies in saliva were developed and validated and their ability to distinguish Leishmania-seronegative from seropositive dogs was evaluated. The analytical study was performed by evaluation of assay precision, sensitivity and accuracy. In addition, serum from 48 dogs (21 Leishmania-seropositive and 27 Leishmania-seronegative) were analyzed by TR-IFMAs. The assays were precise, with an intra- and inter-assay coefficients of variation lower than 11%, and showed high level of accuracy, as determined by linearity under dilution (R 2 =0.99) and recovery tests (>88.60%). Anti-Leishmania IgG2 antibodies in saliva were significantly higher in the seropositive group compared with the seronegative (pLeishmania IgA antibodies between both groups were observed. Furthermore, TR-IFMA for quantification of anti-Leishmania IgG2 antibodies in saliva showed higher differences between seropositive and seronegative dogs than the commercial assay used in serum. In conclusion, TR-IFMAs developed may be used to quantify anti-Leishmania IgG2 and IgA antibodies in canine saliva with an adequate precision, analytical sensitivity and accuracy. Quantification of anti-Leishmania IgG2 antibodies in saliva could be potentially used to evaluate the humoral response in CanL. However, IgA in saliva seemed not to have diagnostic value for this disease. For future studies, it would be desirable to evaluate the ability of the IgG2 assay to detect dogs with subclinical disease or with low antibody titers in serum and also to study the antibodies behaviour in saliva during the

  20. Prevalence of Serum IgG Antibodies to Cystic Echinococcus Antigen among Patients in an Uzbekistan Emergency Hospital.

    Science.gov (United States)

    Park, Se Jin; Han, Sung Sik; Anvarov, Khikmat; Khajibaev, Abdukhakim; Choi, Min-Ho; Hong, Sung-Tae

    2015-12-01

    Cystic echinococcosis (CE) is one of the most widespread zoonotic helminthiases, which can last an asymptomatic infection for several years. The purpose of this study was to demonstrate serum antibody prevalence of CE among asymptomatic people in Uzbekistan using ELISA. A total of 2,547 serum samples were collected, 66 from confirmed CE patients and 2,481 of patients with other diseases than CE at a hospital in Tashkent, Uzbekistan. The serum samples were screened for CE specific IgG antibodies by ELISA using cystic fluid antigen obtained from sheep. The serum antibody positive rate was 89.4% (59/66) in CE and 3.6% (89/2,481) in other disease patients. The present ELISA recognized 89.4% sensitivity and 96.4% specificity. The ELISA absorbance of positive samples was distributed 0.271-0.971 for CE and 0.273-0.887 for other disease patients. The other disease patients with high absorbance over 0.3 were 50 (2.0%) who were presumed to be active CE patients. The patients in their 40s showed the highest positive rate of 5.2% (P=0.181), and women were 4.4% while men were 3.1% positive (P=0.136). The data confirmed that there are many asymptomatic patients of CE in Tashkent. It is indicated that CE is an endemic disease of public health importance in Uzbekistan.

  1. Anti-HIV activity in cervical-vaginal secretions from HIV-positive and -negative women correlate with innate antimicrobial levels and IgG antibodies.

    Directory of Open Access Journals (Sweden)

    Mimi Ghosh

    2010-06-01

    Full Text Available We investigated the impact of antimicrobials in cervicovaginal lavage (CVL from HIV(+ and HIV(- women on target cell infection with HIV. Since female reproductive tract (FRT secretions contain a spectrum of antimicrobials, we hypothesized that CVL from healthy HIV(+ and (- women inhibit HIV infection.CVL from 32 HIV(+ healthy women with high CD4 counts and 15 healthy HIV(- women were collected by gently washing the cervicovaginal area with 10 ml of sterile normal saline. Following centrifugation, anti-HIV activity in CVL was determined by incubating CVL with HIV prior to addition to TZM-bl cells. Antimicrobials and anti-gp160 HIV IgG antibodies were measured by ELISA. When CXCR4 and CCR5 tropic HIV-1 were incubated with CVL from HIV(+ women prior to addition to TZM-bl cells, anti-HIV activity in CVL ranged from none to 100% inhibition depending on the viral strains used. CVL from HIV(- controls showed comparable anti-HIV activity. Analysis of CH077.c (clone of an R5-tropic, mucosally-transmitted founder virus viral inhibition by CVL was comparable to laboratory strains. Measurement of CVL for antimicrobials HBD2, trappin-2/elafin, SLPI and MIP3alpha indicated that each was present in CVL from HIV(+ and HIV(- women. HBD2 and MIP3alpha correlated with anti-HIV activity as did anti-gp160 HIV IgG antibodies in CVL from HIV(+ women.These findings indicate that CVL from healthy HIV(+ and HIV(- women contain innate and adaptive defense mechanisms that inhibit HIV infection. Our data suggest that innate endogenous antimicrobials and HIV-specific IgG in the FRT can act in concert to contribute toward the anti-HIV activity of the CVL and may play a role in inhibition of HIV transmission to women.

  2. Allergenicity, immunogenicity and dose-relationship of three intact allergen vaccines and four allergoid vaccines for subcutaneous grass pollen immunotherapy.

    Science.gov (United States)

    Henmar, H; Lund, G; Lund, L; Petersen, A; Würtzen, P A

    2008-09-01

    Different vaccines containing intact allergens or chemically modified allergoids as active ingredients are commercially available for specific immunotherapy. Allergoids are claimed to have decreased allergenicity without loss of immunogenicity and this is stated to allow administration of high allergoid doses. We compared the allergenicity and immunogenicity of four commercially available chemically modified grass pollen allergoid products with three commercially available intact grass pollen allergen vaccines. The allergenicity was investigated with immunoglobulin (Ig)E-inhibition and basophil activation assays. Human T cell proliferation and specific IgG-titres following mouse immunizations were used to address immunogenicity. Furthermore, intact allergen vaccines with different contents of active ingredients were selected to study the influence of the allergen dose. In general, a lower allergenicity for allergen vaccines was clearly linked to a reduced immunogenicity. Compared with the vaccine with the highest amount of intact allergen, the allergoids caused reduced basophil activation as well as diminished immunogenicity demonstrated by reduced T cell activation and/or reduced induction of murine grass-specific IgG antibodies. Interestingly, intact allergen vaccines with lower content of active ingredient exhibited similarly reduced allergenicity, while immunogenicity was still higher or equal to that of allergoids. The low allergenicity observed for some allergoids was inherently linked to a significantly lower immunogenic response questioning the rationale behind the chemical modification into allergoids. In addition, the linkage between allergenicity, immunogenicity and dose found for intact allergen vaccines and the immunogen as well as allergenic immune responses observed for allergoids suggest that the modified allergen vaccines do not contain high doses of immunologically active ingredients.

  3. Antiradiation Antitoxin IgG : Immunological neutralization of Radiation Toxins at Acute Radiation Syndromes.

    Science.gov (United States)

    Popov, Dmitri; Maliev, Slava

    Introduction: High doses of radiation induce apoptotic necrosis of radio-sensitive cells. Mild doses of radiation induce apoptosis or controlled programmed death of radio-sensitive cells with-out development of inflammation and formation of Radiation Toxins. Cell apoptotic necrosis initiates Radiation Toxins (RT)formation. Radiation Toxins play an important role as a trig-ger mechanism for inflammation development and cell lysis. If an immunotherapy approach to treatment of the acute radiation syndromes (ARS) were to be developed, a consideration could be given to neutralization of radiation toxins (Specific Radiation Determinants-SRD) by specific antiradiation antibodies. Therapeutic neutralization effects of the blocking anti-radiation antibodies on the circulated RT had been studied. Radiation Toxins were isolated from the central lymph of irradiated animals with Cerebrovascular(Cv ARS),Cardiovascular (Cr ARS),Gastrointestinal(Gi ARS) and Haemopoietic (Hp ARS) forms of ARS. To accomplish this objective, irradiated animals were injected with a preparation of anti-radiation immunoglobulin G (IgG) obtained from hyperimmune donors. Radiation-induced toxins that we call Specific Radiation Determinants (SRD) possess toxic (neurotoxic, haemotoxic) characteristics as well as specific antigenic properties. Depending on direct physiochemical radiation damage, they can induce development of many of the pathological processes associated with ARS. We have tested several specific hyperimmune IgG preparations against these radiation toxins and ob-served that their toxic properties were neutralized by the specific antiradiation IgGs. Material and Methods: A scheme of experiments was following: 1.Isolation of radiation toxins (RT) from the central lymph of irradiated animals with different form of ARS. 2.Transformation of a toxic form of the RT to a toxoid form of the RT. 3.Immunization of radiation naive animals. Four groups of rabbits were inoculated with a toxoid form of SRD

  4. IgG4-related sialadenitis and Sjögren's syndrome.

    Science.gov (United States)

    Fragoulis, G E; Zampeli, E; Moutsopoulos, H M

    2017-03-01

    IgG4-related disease (IgG4-RD) has emerged as a new entity in the last decade. It comprises numerous conditions previously thought to be unrelated. Macroscopically, these diseases cause diffuse organ swelling and formation of pseudotumorous masses. Histopathologically, they are characterized by a lymphoplasmacytic infiltrate with increased IgG4+ plasma cells and storiform fibrosis. Despite rapid progress within the last years, our knowledge on these conditions is still fragmented. To date, more than forty organs have been reported to be included in IgG4-RD, and salivary gland involvement is amongst the most common organs affected [IgG4-related sialadenitis (IgG4-RS)]. Interestingly, IgG4-RS shares commonalities with Sjögren's syndrome (SS), like glandular enlargement, sicca symptoms, arthralgias, hypergammaglobulinemia, hypocomplementemia, and circulating antinuclear antibodies. Nonetheless, they differ in that the incidence of anti-Ro and anti-La reactivity is not frequently found in patients with IgG4-RS, their salivary glands are infiltrated by a large number of IgG4+ plasma cells and IgG4-RS symptoms respond promptly to steroids. The aim of this review was to describe the clinical, serological, histopathological and pathophysiological aspects of IgG4-RS in the context of IgG4-RD and highlight the differences between IgG4-RS and SS. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. How immunoglobulin G antibodies kill target cells: revisiting an old paradigm.

    Science.gov (United States)

    Biburger, Markus; Lux, Anja; Nimmerjahn, Falk

    2014-01-01

    The capacity of immunoglobulin G (IgG) antibodies to eliminate virtually any target cell has resulted in the widespread introduction of cytotoxic antibodies into the clinic in settings of cancer therapy, autoimmunity, and transplantation, for example. More recently, it has become apparent that also the protection from viral infection via IgG antibodies may require cytotoxic effector functions, suggesting that antibody-dependent cellular cytotoxicity (ADCC) directed against malignant or virally infected cells is one of the most essential effector mechanisms triggered by IgG antibodies to protect the host. A detailed understanding of the underlying molecular and cellular pathways is critical, therefore, to make full use of this antibody effector function. Several studies over the last years have provided novel insights into the effector pathways and innate immune effector cells responsible for ADCC reactions. One of the most notable outcomes of many of these reports is that cells of the mononuclear phagocytic system rather than natural killer cells are critical for removal of IgG opsonized target cells in vivo. © 2014 Elsevier Inc. All rights reserved.

  6. Homogeneous immunoassay for human IgG using oriented hen egg IgY immobilized on gold sol nanoparticles

    International Nuclear Information System (INIS)

    Yeritsyan, H.E.; Gasparyan, V.K.

    2012-01-01

    Homogeneous immunoassays using (red) gold nanoparticles represent an attractive detection scheme because of the option of photometric readout. We have applied oriented immobilization of hen egg immunoglobulin Y (IgY) on gold nanoparticles when developing a homogeneous immunoassay for human IgG. In oriented immobilization, as opposed to random immobilization, the antigen binding capabilities of the antibodies are retained. It is shown that such immunoassay has significantly better sensitivity in comparison with methods based on conventional immobilization of affinity-purified antibodies. It is also shown that hen egg IgY is better suited than rabbit antibodies, because much more antibody can be immobilized on gold nanoparticles without any destabilization, probably because of the more acidic nature of these antibodies. In addition, hen egg IgY can be supplied in higher quantity and can be prepared more easily than IgG from rabbits. Bleeding and slaughtering of animals is not needed. The assay presented here has a wide detection range (30-500 ng. mL -1 ) and a limit of detection as low as 30 ng. mL -1 of human IgG. (author)

  7. Antigen-antibody reactions of UV-irradiated phage DNA

    International Nuclear Information System (INIS)

    Fink, A.

    1976-01-01

    The observation of others could be confirmed that UV-irradiated DNA is a better immunogen than unirradiated DNA. The author's immune sera contained a high amount of antibodies with a specific action against photoproducts in the DNA. The thymine dimer was identified as relevant photoproduct and thus as antigenic determinant. In comparison, the amount of unspecific antibodies reacting with denaturated DNA was low and varied between sera. Thymin-dimer antibodies showed a high specificity without cross-reaction with other pyrimidine dimers such as anti CC and anti CT; they belong to the class of IgG molecules. UV-irradiated dinucleotide dTpT is sufficient to induce the formation of antibodies reacting with the cis-syn thymine dimers in UV-irradiated DNA. Antibody binding is proportional to the UV doses applied to the DNA. When using completely denaturated DNA, there is a linear increase changing into a plateau at higher doses. The extent of antigen-antibody binding is strongly dependent on the degree of denaturation of the DNA. With increasing denaturation, the antibody binding of the DNA increases. The antigen-antibody reaction can thus be used to estimate the degree of denaturation of the DNA. There were no signs of an influence of the degree of denaturation of the DNA on the quantum yield of thymine dimers. The different amounts of antibodies is therefore due to the masking of thymine dimers in native DNA. When irradiating intact phage particles, there was no sign of an influence of the phages' protein covers on the antibody binding capacity of DNA compared with DNA irradiated in vitro. (orig.) [de

  8. Low anti-streptokinase IgG concentrations following streptokinase-streptodornase treatment of leg ulcer patients

    DEFF Research Database (Denmark)

    Munkvad, S; Breuning, L; Tvedskov, Jesper

    1994-01-01

    We have evaluated whether neutralising anti-streptokinase IgG antibodies are produced following streptokinase-streptodornase therapy of leg ulcer patients. Serum anti-streptokinase IgG concentrations in 10 leg ulcer patients were determined before, and 1 week, 2 weeks, and 3 weeks following the t...... the treatment. We observed only a negligible increase in neutralizing anti-streptokinase IgG concentrations during the observation period, which was probably of no therapeutical significance....

  9. Optimization of photoactive protein Z for fast and efficient site-specific conjugation of native IgG.

    Science.gov (United States)

    Hui, James Z; Tsourkas, Andrew

    2014-09-17

    Antibody conjugates have been used in a variety of applications from immunoassays to drug conjugates. However, it is becoming increasingly clear that in order to maximize an antibody's antigen binding ability and to produce homogeneous antibody-conjugates, the conjugated molecule should be attached onto IgG site-specifically. We previously developed a facile method for the site-specific modification of full length, native IgGs by engineering a recombinant Protein Z that forms a covalent link to the Fc domain of IgG upon exposure to long wavelength UV light. To further improve the efficiency of Protein Z production and IgG conjugation, we constructed a panel of 13 different Protein Z variants with the UV-active amino acid benzoylphenylalanine (BPA) in different locations. By using this panel of Protein Z to cross-link a range of IgGs from different hosts, including human, mouse, and rat, we discovered two previously unknown Protein Z variants, L17BPA and K35BPA, that are capable of cross-linking many commonly used IgG isotypes with efficiencies ranging from 60% to 95% after only 1 h of UV exposure. When compared to existing site-specific methods, which often require cloning or enzymatic reactions, the Protein Z-based method described here, utilizing the L17BPA, K35BPA, and the previously described Q32BPA variants, represents a vastly more accessible and efficient approach that is compatible with nearly all native IgGs, thus making site-specific conjugation more accessible to the general research community.

  10. The effect of parenteral immunisation on antibody production in the pig colon.

    Science.gov (United States)

    Rees, A S; Lysons, R J; Stokes, C R; Bourne, F J

    1989-11-30

    Local and systemic antibody production was studied in pigs to compare responses to live and killed bacterial antigen and purified protein antigen, with and without prior mucosal stimulation. Recovery from challenge with live bacteria and intramuscular injection with killed bacteria gave rise to similar high levels of serum IgG antibody, but the ratio of specific IgA to IgG in the colon was significantly higher after infection than following vaccination with killed bacteria. Vaccination with a protein antigen gave rise to serum and local antibody production. Prior feeding of the antigen had a tolerising effect on the serum antibody response, but production of IgG and IgA antibody by the colon was not suppressed.

  11. Seroprevalence of Leptospira antibodies among populations at risk

    Directory of Open Access Journals (Sweden)

    Abdul-Baki Abdullah Al-Robasi

    2015-03-01

    Full Text Available Objective: This study was performed to assess the Leptospira IgG antibodies seroprevalence among populations at risk in Hodeida Governorate, Yemen. Methods: A total of 200 subjects (136 males and 64 females participated in this study during June and December 2012.They represented 10 sewage workers, 22 butchers, 16 construction workers, 108 agriculture workers, 20 hospital sanitary workers and 24 blood donors. Predesigned questionnaires and consent were taken from each individual. Blood samples were collected from subjects, and the sera were tested by ELISA to detect the presence of leptospira IgG antibodies. The possible related factors for seropositivity were evaluated. Results: Leptospira IgG antibodies were found positive in 42% of the participants. The highest seroprevalence level was detected in sewage workers (80%, followed by hospital sanitary workers (60%, construction workers (37.5% and farmers (37%. The lowest of antibodies was in butchers (36.4%. Seroprevalence among blood donors was 25% which was comparatively less than of the populations at risk. Seropositivity of Leptospira IgG antibodies was found higher among males than females (42.6% vs. 34.4%. The highest Leptospira antibodies seropositivity was among elderly participants (81.8%. The seropositivity of antibodies in population live in rural and urban areas was not significant differences. As for closely contacting with animals, the highest antibodies were discovered in people who had goats (80% and sheep (60.9%. Conclusion: Individuals engaged in risk activities are often exposed to leptospiral infection. Therefore, control and prevention policy toward these people are necessary. J Microbiol Infect Dis 2015;5(1: 1-4

  12. Brain antibodies in the cortex and blood of people with schizophrenia and controls.

    Science.gov (United States)

    Glass, L J; Sinclair, D; Boerrigter, D; Naude, K; Fung, S J; Brown, D; Catts, V S; Tooney, P; O'Donnell, M; Lenroot, R; Galletly, C; Liu, D; Weickert, T W; Shannon Weickert, C

    2017-08-08

    The immune system is implicated in the pathogenesis of schizophrenia, with elevated proinflammatory cytokine mRNAs found in the brains of ~40% of individuals with the disorder. However, it is not clear if antibodies (specifically immunoglobulin-γ (IgG)) can be found in the brain of people with schizophrenia and if their abundance relates to brain inflammatory cytokine mRNA levels. Therefore, we investigated the localization and abundance of IgG in the frontal cortex of people with schizophrenia and controls, and the impact of proinflammatory cytokine status on IgG abundance in these groups. Brain IgGs were detected surrounding blood vessels in the human and non-human primate frontal cortex by immunohistochemistry. IgG levels did not differ significantly between schizophrenia cases and controls, or between schizophrenia cases in 'high' and 'low' proinflammatory cytokine subgroups. Consistent with the existence of IgG in the parenchyma of human brain, mRNA and protein of the IgG transporter (FcGRT) were present in the brain, and did not differ according to diagnosis or inflammatory status. Finally, brain-reactive antibody presence and abundance was investigated in the blood of living people. The plasma of living schizophrenia patients and healthy controls contained antibodies that displayed positive binding to Rhesus macaque cerebellar tissue, and the abundance of these antibodies was significantly lower in patients than controls. These findings suggest that antibodies in the brain and brain-reactive antibodies in the blood are present under normal circumstances.

  13. Determining the IgM and IgG antibody titer against CMV and helicobacter pylori in the serum of multiple sclerosis patients comparing to the control group in Hamadan.

    Science.gov (United States)

    Salim, Masome Afiati; Eftekharian, Mohammad Mahdi; Taheri, Mohammad; Yousef Alikhani, Mohammad

    2017-07-19

    Multiple sclerosis (MS) is a chronic autoimmune disease that disables central nervous system (CNS) system. Cytomegalovirus (CMV) probably has an important role in the MS pathology. The infection with helicobacter pylori also is recognized as a protective agent against MS in female. Serum samples were isolated and frozen at -70∘C. The earlier mentioned anti-virus antibodies and antibacterial antibodies were quantified by Elisa kit. The results showed that IgG antibody average value against cytomegalovirus in the blood of multiple sclerosis patients not only decreased but also was significant statistically (pmultiple sclerosis patients against helicobacter pylori shown a statistically significant decrease (pmultiple sclerosis patients.

  14. Comparative study of the second antibody for radioimmunoassay totally produced in the country to a similar imported one (sheep serum anti-rabbit IgG)

    International Nuclear Information System (INIS)

    Silva, S.R. da; Borghi, V.C.; Wajchenberg, B.L.

    1992-01-01

    This work compares a second antibody for radioimmunoassay (RIA) produced at IPEN-CNEN/SP with a commercial one of known quality, produced by Radioassay Systems Laboratories, U.S.A.. This antiserum, sheep serum anti-rabbit IgG produced in its totality in the country, presented title and precipitation characteristics similar to those exhibited by the commercial product, being as suitable for the RIA separation as its imported similar. (author)

  15. Evaluation of treatment of colostrum-deprived kittens with equine IgG.

    Science.gov (United States)

    Crawford, P Cynda; Hanel, Rita M; Levy, Julie K

    2003-08-01

    To evaluate equine IgG as a treatment for kittens with failure of passive transfer of immunity (FPT). 13 specific pathogen-free queens and their 77 kittens. Kittens were randomized at birth into 9 treatment groups. One group contained colostrum-fed (nursing) kittens; the other groups contained colostrum-deprived kittens that were administered supplemental feline or equine IgG PO or SC during the first 12 hours after birth. Blood samples were collected at serial time points from birth to 56 days of age for determination of serum IgG concentrations. The capacity of equine IgG to opsonize bacteria for phagocytosis by feline neutrophils was determined via flow cytometry. Kittens that received feline or equine IgG SC had significantly higher serum IgG concentrations than those of kittens that received the supplements PO. In kittens that were administered supplemental IgG SC, serum IgG concentrations were considered adequate for protection against infection. The half-life of IgG in kittens treated with equine IgG was shorter than that in kittens treated with feline IgG. Feline IgG significantly enhanced the phagocytosis of bacteria by feline neutrophils, but equine IgG did not. Serum concentrations of equine IgG that are considered protective against infection are easily attained in kittens, but the failure of these antibodies to promote bacterial phagocytosis in vitro suggests that equine IgG may be an inappropriate treatment for FPT in kittens.

  16. Sphingosine-1-phosphate (S1P) enhances glomerular endothelial cells activation mediated by anti-myeloperoxidase antibody-positive IgG.

    Science.gov (United States)

    Sun, Xiao-Jing; Chen, Min; Zhao, Ming-Hui

    2018-03-01

    Cumulating evidences suggested an important role of sphingosine-1-phosphate (S1P) and its receptors in regulating endothelial barrier integrity. Our previous study revealed that the circulating S1P levels and renal expression of S1PRs correlated with disease activity and renal damage in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This study investigated the role of S1P and its receptors in myeloperoxidase (MPO)-ANCA-positive IgG-mediated glomerular endothelial cell (GEnC) activation. The effect of S1P on morphological alteration of GEnCs in the presence of MPO-ANCA-positive IgG was observed. Permeability assay was performed to determine endothelial monolayer activation in quantity. Both membrane-bound and soluble ICAM-1 and VCAM-1 levels were measured. Furthermore, antagonists and/or agonists of various S1PRs were employed to determine the role of different S1PRs. S1P enhanced MPO-ANCA-positive IgG-induced disruption of tight junction and disorganization of cytoskeleton in GEnCs. S1P induced further increase in monolayer permeability of GEnC monolayers in the presence of MPO-ANCA-positive IgG. S1P enhanced MPO-ANCA-positive IgG-induced membrane-bound and soluble ICAM-1/VCAM-1 up-regulation of GEnCs. Soluble ICAM-1 levels in the supernatants of GEnCs stimulated by S1P and MPO-ANCA-positive IgG increased upon pre-incubation of S1PR1 antagonist, while pre-incubation of GEnCs with the S1PR1 agonist down-regulated sICAM-1 level. Blocking S1PR2-4 reduced sICAM-1 levels in the supernatants of GEnCs stimulated by S1P and MPO-ANCA-positive IgG. Pre-incubation with S1PR5 agonist could increase sICAM-1 level in the supernatants of GEnC stimulated by S1P and MPO-ANCA-positive IgG. S1P can enhance MPO-ANCA-positive IgG-mediated GEnC activation through S1PR2-5. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  17. Analysis of antibody and cytokine markers for leprosy nerve damage and reactions in the INFIR cohort in India.

    Directory of Open Access Journals (Sweden)

    Rupendra Jadhav

    2011-03-01

    Full Text Available The ILEP Nerve Function Impairment in Reaction (INFIR is a cohort study designed to identify predictors of reactions and nerve function impairment (NFI in leprosy.Antibodies to mycobacteria, nerve components and serum cytokine were measured as potential markers for their possible association with reactions and NFI.303 newly diagnosed leprosy patients from two centres in North India were enrolled. Antibodies to PGL-1, LAM (IgG1 and IgG3, ceramide, S100 and TNFα levels were measured using ELISA techniques.S-100, PGL IgG and IgM antibody levels were lowest in patients with BT leprosy and highest in patients with lepromatous leprosy. LAM IgG1 and LAM IgG3 antibody levels were highest in patients with BL leprosy. Ceramide antibody levels were not correlated with type of leprosy. Levels of all the antibodies tested and TNF α were lowest in patients with only skin reaction. PGL IgM antibody levels were elevated in patients with skin reactions and NFI. Old sensory NFI is associated with significant elevation of PGL IgG, LAM IgG and S100 antibody levels.These results reveal that the antibody response to mycobacterial antigens, nerve antigens and cytokines are in a dynamic flux and could collectively contribute to NFI in leprosy. The association of multiple markers with old NFI may indicate the contribution of different pathological processes.

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

    DEFF Research Database (Denmark)

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

    1993-01-01

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

  19. Selective localization of IgG from cerebrospinal fluid to brain parenchyma

    DEFF Research Database (Denmark)

    Mørch, Marlene Thorsen; Forsberg Sørensen, Sofie; Khorooshi, Reza M. H.

    2018-01-01

    the cerebrospinal fluid and induce subpial and periventricular NMO-like lesions and blood-brain barrier breakdown, in a complement-dependent manner. To investigate how IgG trafficking from cerebrospinal fluid to brain parenchyma can be influenced by injury. IgG from healthy donors was intrathecally injected...... into the cerebrospinal fluid via cisterna magna at 1, 2, 4, or 7 days after a distal stereotactic sterile needle insertion to the striatum. Antibody deposition, detected by staining for human IgG, peaked 1 day after the intrathecal injection and was selectively seen close to the needle insertion. When NMO...

  20. Hepatitis C viremia is associated with cytomegalovirus IgG antibody levels in HIV-infected women.

    Directory of Open Access Journals (Sweden)

    Mark H Kuniholm

    Full Text Available Individuals with HIV infection exhibit high cytomegalovirus (CMV IgG levels, but there are few data regarding the association of hepatitis C virus (HCV with the immune response against CMV.Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART prior to or at CMV testing.In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 - 4.83; P = 0.004. The association of HCV RNA with CMV IgG differed by age (P(interaction = 0.0007, with a strong association observed among women in the low and middle age tertiles (≤ 45.3 years of age; β = 6.21, 95% CI:3.30 - 9.11, P<0.0001 but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV IgG levels did not affect the association between HCV and CMV.CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients.

  1. Polyfunctional HIV-Specific Antibody Responses Are Associated with Spontaneous HIV Control.

    Directory of Open Access Journals (Sweden)

    Margaret E Ackerman

    2016-01-01

    Full Text Available Elite controllers (ECs represent a unique model of a functional cure for HIV-1 infection as these individuals develop HIV-specific immunity able to persistently suppress viremia. Because accumulating evidence suggests that HIV controllers generate antibodies with enhanced capacity to drive antibody-dependent cellular cytotoxicity (ADCC that may contribute to viral containment, we profiled an array of extra-neutralizing antibody effector functions across HIV-infected populations with varying degrees of viral control to define the characteristics of antibodies associated with spontaneous control. While neither the overall magnitude of antibody titer nor individual effector functions were increased in ECs, a more functionally coordinated innate immune-recruiting response was observed. Specifically, ECs demonstrated polyfunctional humoral immune responses able to coordinately recruit ADCC, other NK functions, monocyte and neutrophil phagocytosis, and complement. This functionally coordinated response was associated with qualitatively superior IgG3/IgG1 responses, whereas HIV-specific IgG2/IgG4 responses, prevalent among viremic subjects, were associated with poorer overall antibody activity. Rather than linking viral control to any single activity, this study highlights the critical nature of functionally coordinated antibodies in HIV control and associates this polyfunctionality with preferential induction of potent antibody subclasses, supporting coordinated antibody activity as a goal in strategies directed at an HIV-1 functional cure.

  2. Clinical significance of anti-domain 1 β2-glycoprotein I antibodies in antiphospholipid syndrome.

    Science.gov (United States)

    Iwaniec, Teresa; Kaczor, Marcin P; Celińska-Löwenhoff, Magdalena; Polański, Stanisław; Musiał, Jacek

    2017-05-01

    Antiphospholipid syndrome (APS) is characterized by the presence of circulating antiphospholipid antibodies (aPL) in patients with thrombosis and/or pregnancy morbidity. In APS patients anti-domain 1 β2-glycoprotein I (anti-D1 β2GPI) IgG antibodies correlate strongly with thrombosis and to the lesser extent, with pregnancy complications. The aim of this study was to assess clinical utility of the anti-D1 β2GPI antibodies in the diagnosis and risk stratification of antiphospholipid syndrome. In this retrospective study 202 autoimmune patients were studied (primary APS - 58, secondary - 45 SLE - 99). Anticardiolipin (aCL) and anti-β 2 GPI (aβ 2 GPI antibodies) (IgG and IgM class) together with anti-D1 IgG were tested with QUANTA Flash chemiluminescent immunoassay and lupus anticoagulant (LA) with coagulometric methods. The highest anti-D1 values were observed in triple positive patients as compared to patients with other antiphospholipid antibody profiles. A strong correlation was found between levels of anti-D1 IgG and a β2GPI IgG antibodies for all patients analyzed (Spearman's ρ=0.87; p<0.0001). Anti-D1 IgG antibodies increase specificity resulting from classic aPL positivity but at the expense of sensitivity. Anti-D1 test does not add accuracy in predicting APS thrombotic complications on the top of accuracy offered by classic aPL tests and their profiles. Anti-D1 IgG antibodies did not add diagnostic power to the standard laboratory aPL tests as assessed by this retrospective study. A true clinical significance of anti-D1 antibodies in thrombotic risk stratification of aPL positive patients will require a properly designed clinical prospective trials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. 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.

  4. Thrombosis and antiphospholipid antibody syndrome during acute Q fever

    Science.gov (United States)

    Million, Matthieu; Bardin, Nathalie; Bessis, Simon; Nouiakh, Nadia; Douliery, Charlaine; Edouard, Sophie; Angelakis, Emmanouil; Bosseray, Annick; Epaulard, Olivier; Branger, Stéphanie; Chaudier, Bernard; Blanc-Laserre, Karine; Ferreira-Maldent, Nicole; Demonchy, Elisa; Roblot, France; Reynes, Jacques; Djossou, Felix; Protopopescu, Camelia; Carrieri, Patrizia; Camoin-Jau, Laurence; Mege, Jean-Louis; Raoult, Didier

    2017-01-01

    Abstract Q fever is a neglected and potentially fatal disease. During acute Q fever, antiphospholipid antibodies are very prevalent and have been associated with fever, thrombocytopenia, acquired heart valve disease, and progression to chronic endocarditis. However, thrombosis, the main clinical criterion of the 2006 updated classification of the antiphospholipid syndrome, has not been assessed in this context. To test whether thrombosis is associated with antiphospholipid antibodies and whether the criteria for antiphospholipid syndrome can be met in patients with acute Q fever, we conducted a cross-sectional study at the French National Referral Center for Q fever. Patients included were diagnosed with acute Q fever in our Center between January 2007 and December 2015. Each patient's history and clinical characteristics were recorded with a standardized questionnaire. Predictive factors associated with thrombosis were assessed using a rare events logistic regression model. IgG anticardiolipin antibodies (IgG aCL) assessed by an enzyme-linked immunosorbent assay were tested on the Q fever diagnostic serum. A dose-dependent relationship between IgG aCL levels and thrombosis was tested using a receiver operating characteristic (ROC) analysis. Of the 664 patients identified for inclusion in the study, 313 (47.1%) had positive IgG aCL and 13 (1.9%) were diagnosed with thrombosis. Three patients fulfilled the antiphospholipid syndrome criteria. After multiple adjustments, only positive IgG aCL (relative risk, 14.46 [1.85–113.14], P = .011) were independently associated with thrombosis. ROC analysis identified a dose-dependent relationship between IgG aCL levels and occurrence of thrombosis (area under curve, 0.83, 95%CI [0.73–0.93], P antiphospholipid antibodies are associated with thrombosis, thrombocytopenia, and acquired valvular heart disease. Antiphospholipid antibodies should be systematically assessed in acute Q fever patients. Hydroxychloroquine

  5. Highly sensitive detection of human IgG using a novel bio-barcode assay combined with DNA chip technology

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhenbao [Central South University, School of Pharmaceutical Sciences (China); Zhou, Bo, E-mail: zhoubo1771@163.com [The Affiliated Zhongda Hospital of Southeast University, Department of Gerontology (China); Wang, Haiqing; Lu, Feng; Liu, Tianjun; Song, Cunxian; Leng, Xigang, E-mail: lengxigyky@163.com [Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College (China)

    2013-09-15

    A simple and ultrasensitive detection of human IgG based on signal amplification using a novel bio-barcode assay and DNA chip technology was developed. The sensing platform was a sandwich system made up of antibody-modified magnetic microparticles (Ab-MMPs)/human IgG/Cy3-labeled single-stranded DNA and antibody-modified gold nanoparticles (Cy3-ssDNA-Ab-AuNPs). The MMPs (2.5 {mu}m in diameter) modified with mouse anti-human IgG monoclonal-antibodies could capture human IgG and further be separated and enriched via a magnetic field. The AuNPs (13 nm in diameter) conjugated with goat anti-human IgG polyclonal-antibodies and Cy3-ssDNA could further combine with the human IgG/Ab-MMP complex. The Cy3-ssDNA on AuNPs was then released by TCEP to hybridize with the DNA chip, thus generating a detectable signal by the fluorescence intensity of Cy3. In order to improve detection sensitivity, a three-level cascaded signal amplification was developed: (1) The MMP enrichment as the first-level; (2) Large quantities of Cy3-ssDNA on AuNPs as the second-level; (3) The Cy3-ssDNA conjugate with DNA chip as the third-level. The highly sensitive technique showed an increased response of the fluorescence intensity to the increased concentration of human IgG through a detection range from 1 pg mL{sup -1} to 10 ng mL{sup -1}. This sensing technique could not only improve the detection sensitivity for the low concentration of human IgG but also present a robust and efficient signal amplification model. The detection method has good stability, specificity, and reproducibility and could be applied in the detection of human IgG in the real samples.

  6. Highly sensitive detection of human IgG using a novel bio-barcode assay combined with DNA chip technology

    Science.gov (United States)

    Liu, Zhenbao; Zhou, Bo; Wang, Haiqing; Lu, Feng; Liu, Tianjun; Song, Cunxian; Leng, Xigang

    2013-09-01

    A simple and ultrasensitive detection of human IgG based on signal amplification using a novel bio-barcode assay and DNA chip technology was developed. The sensing platform was a sandwich system made up of antibody-modified magnetic microparticles (Ab-MMPs)/human IgG/Cy3-labeled single-stranded DNA and antibody-modified gold nanoparticles (Cy3-ssDNA-Ab-AuNPs). The MMPs (2.5 μm in diameter) modified with mouse anti-human IgG monoclonal-antibodies could capture human IgG and further be separated and enriched via a magnetic field. The AuNPs (13 nm in diameter) conjugated with goat anti-human IgG polyclonal-antibodies and Cy3-ssDNA could further combine with the human IgG/Ab-MMP complex. The Cy3-ssDNA on AuNPs was then released by TCEP to hybridize with the DNA chip, thus generating a detectable signal by the fluorescence intensity of Cy3. In order to improve detection sensitivity, a three-level cascaded signal amplification was developed: (1) The MMP enrichment as the first-level; (2) Large quantities of Cy3-ssDNA on AuNPs as the second-level; (3) The Cy3-ssDNA conjugate with DNA chip as the third-level. The highly sensitive technique showed an increased response of the fluorescence intensity to the increased concentration of human IgG through a detection range from 1 pg mL-1 to 10 ng mL-1. This sensing technique could not only improve the detection sensitivity for the low concentration of human IgG but also present a robust and efficient signal amplification model. The detection method has good stability, specificity, and reproducibility and could be applied in the detection of human IgG in the real samples.

  7. Highly sensitive detection of human IgG using a novel bio-barcode assay combined with DNA chip technology

    International Nuclear Information System (INIS)

    Liu, Zhenbao; Zhou, Bo; Wang, Haiqing; Lu, Feng; Liu, Tianjun; Song, Cunxian; Leng, Xigang

    2013-01-01

    A simple and ultrasensitive detection of human IgG based on signal amplification using a novel bio-barcode assay and DNA chip technology was developed. The sensing platform was a sandwich system made up of antibody-modified magnetic microparticles (Ab-MMPs)/human IgG/Cy3-labeled single-stranded DNA and antibody-modified gold nanoparticles (Cy3-ssDNA-Ab-AuNPs). The MMPs (2.5 μm in diameter) modified with mouse anti-human IgG monoclonal-antibodies could capture human IgG and further be separated and enriched via a magnetic field. The AuNPs (13 nm in diameter) conjugated with goat anti-human IgG polyclonal-antibodies and Cy3-ssDNA could further combine with the human IgG/Ab-MMP complex. The Cy3-ssDNA on AuNPs was then released by TCEP to hybridize with the DNA chip, thus generating a detectable signal by the fluorescence intensity of Cy3. In order to improve detection sensitivity, a three-level cascaded signal amplification was developed: (1) The MMP enrichment as the first-level; (2) Large quantities of Cy3-ssDNA on AuNPs as the second-level; (3) The Cy3-ssDNA conjugate with DNA chip as the third-level. The highly sensitive technique showed an increased response of the fluorescence intensity to the increased concentration of human IgG through a detection range from 1 pg mL −1 to 10 ng mL −1 . This sensing technique could not only improve the detection sensitivity for the low concentration of human IgG but also present a robust and efficient signal amplification model. The detection method has good stability, specificity, and reproducibility and could be applied in the detection of human IgG in the real samples

  8. Passive immunization against Cryptococcus neoformans with an isotype-switch family of monoclonal antibodies reactive with cryptococcal polysaccharide.

    OpenAIRE

    Sanford, J E; Lupan, D M; Schlageter, A M; Kozel, T R

    1990-01-01

    The in vivo properties of an immunoglobulin isotype-switch family of monoclonal antibodies specific for the polysaccharide capsule of Cryptococcus neoformans were examined in a murine model of cryptococcosis. Subclass-switch variants were isolated by sequential sublining of an immunoglobulin G subclass 1 (IgG1)-secreting cell line. Antibodies of the IgG1, IgG2a, and IgG2b isotypes with identical reactivities with cryptococcal polysaccharide were prepared. The antibodies had the distinct biolo...

  9. Analysis of the relations between allergen specific LgG antibody and allergic dermatosis of 14 kinds foods

    Directory of Open Access Journals (Sweden)

    Yin’e Hu

    2015-01-01

    Full Text Available To use food-specific IgG antibody detection to explore its application in the allergy dermatoses. 181 patients were included from January 2014 to September 2014. Fourteen food-specific IgG antibodies were detected by ELISA. The positive rates of IgG antibody of the patient group and the healthy group were significantly different. The positive rates of IgG antibody of egg, milk, shrimp and crab took a large proportion in three groups of patients with three kinds of allergy dermatoses of urticaria, eczema and allergic dermatitis, the proportion of which was respectively 70.2%, 77.8% and 71.7%. There was mild and moderate intolerance of food in the allergic dermatitis group while there was no distribution difference of food intolerance in urticaria group and eczema group. Among urticaria and allergic dermatitis patients with positive antibody, the positive rate of children was significantly higher than that of adults while there was no significant difference between children and adults among eczema patients with positive antibody. Allergy dermatoses are closely related to food-specific IgG antibody and the allergy dermatoses patients have a high incidence rate of food intolerance; detecting IgG antibody in patients is of great significance for the diagnosis and treatment of allergy dermatoses.

  10. Presence of Mycoplasma fermentans in the bloodstream of Mexican patients with rheumatoid arthritis and IgM and IgG antibodies against whole microorganism

    Directory of Open Access Journals (Sweden)

    Salinas Salvador

    2009-08-01

    Full Text Available Abstract Background Increasing evidence incriminates bacteria, especially Mycoplasma fermentans, as possible arthritogenic agents in humans. The purpose of this study was to investigate M. fermentans in the bloodstream of patients with rheumatoid arthritis. Methods Two hundred and nineteen blood samples from patients with rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, and healthy individuals were screened by bacterial culture and direct PCR in order to detect mycoplasmas; IgM and IgG against M. fermentans PG18 were also detected by ELISA and Immunoblotting assays in patients with rheumatoid arthritis and healthy individuals. Results Blood samples from patients with antiphospholipid syndrome and healthy individuals were negative for mycoplasma by culture or direct PCR. In blood samples from patients with systemic lupus erythematosus were detected by direct PCR M. fermentans in 2/50 (2%, M. hominis in 2/50 (2% and U. urealyticum in 1/50 (0.5%. In patients with RA M. fermentans was detected by culture in 13/87 blood samples and in 13/87 by direct PCR, however, there was only concordance between culture and direct PCR in six samples, so M. fermentans was detected in 20/87(23% of the blood samples from patients with RA by either culture or PCR. Antibody-specific ELISA assay to M. fermentans PG18 was done, IgM was detected in sera from 40/87 patients with RA and in sera of 7/67 control individuals, IgG was detected in sera from 48/87 RA patients and in sera from 7/67 healthy individuals. Antibody-specific immunoblotting to M. fermentans PG18 showed IgM in sera from 35/87 patients with RA and in sera from 4/67 healthy individuals, IgG was detected in sera from 34/87 patients and in sera from 5/67 healthy individuals. Conclusion Our findings show that only M. fermentans produce bacteremia in a high percentage of patients with RA. This finding is similar to those reported in the literature. IgM and IgG against M

  11. Hepatitis C Viremia Is Associated with Cytomegalovirus IgG Antibody Levels in HIV-Infected Women

    Science.gov (United States)

    Kuniholm, Mark H.; Parrinello, Christina M.; Anastos, Kathryn; Augenbraun, Michael; Plankey, Michael; Nowicki, Marek; Peters, Marion; Golub, Elizabeth T.; Lurain, Nell; Landay, Alan L.; Strickler, Howard D.; Kaplan, Robert C.

    2013-01-01

    Background Individuals with HIV infection exhibit high cytomegalovirus (CMV) IgG levels, but there are few data regarding the association of hepatitis C virus (HCV) with the immune response against CMV. Methods Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART) prior to or at CMV testing. Results In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 – 4.83; P = 0.004). The association of HCV RNA with CMV IgG differed by age (P interaction = 0.0007), with a strong association observed among women in the low and middle age tertiles (≤45.3 years of age; β = 6.21, 95% CI:3.30 – 9.11, P<0.0001) but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV) IgG levels did not affect the association between HCV and CMV. Conclusions CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients. PMID:23613990

  12. Catalase activity of IgG antibodies from the sera of healthy donors and patients with schizophrenia.

    Science.gov (United States)

    Ermakov, Evgeny A; Smirnova, Ludmila P; Bokhan, Nikolay A; Semke, Arkadiy V; Ivanova, Svetlana A; Buneva, Valentina N; Nevinsky, Georgy A

    2017-01-01

    We present first evidence showing that some electrophoretically homogeneous IgGs from the sera of patients with schizophrenia (36.4%) and their Fab and F(ab)2 fragments as well as from healthy donors (33.3%) possess catalase activity. The relative catalase activity of IgGs from the sera of individual schizophrenia patients (and healthy donors) significantly varied from patient to patient, but the activity of IgGs from healthy donors is on average 15.8-fold lower than that for schizophrenia patients. After extensive dialysis of purified IgGs against EDTA chelating metal ions, the relative catalase activity of IgGs decreases on average approximately 2.5-3.7-fold; all IgGs possess metal-dependent and independent catalase activity. The addition of external Me2+ ions to dialyzed and non-dialyzed IgGs leads to a significant increase in their activity. The best activator of dialyzed and non-dialyzed IgGs is Co2+, the activation by Cu2+, Mn2+, and Ni2+ ions were rare and always lower than by Co2+. Every IgG preparation demonstrates several individual sets of very well expressed pH optima in the pH range from 4.0 to 9.5. These data speak for the individual repertoire of catalase IgGs in every person and an extreme diversity of abzymes in their pH optima and activation by different metal ions. It is known that antioxidant enzymes such as superoxide dismutases, catalases, and glutathione peroxidases represent critical defense mechanisms preventing oxidative modifications of DNA, proteins, and lipids. Catalase activity of human IgGs could probably also play a major role in the protection of organisms from oxidative stress and toxic compounds.

  13. Mouse allergen exposure and immunologic responses: IgE-mediated mouse sensitization and mouse specific IgG and IgG4 levels

    NARCIS (Netherlands)

    Matsui, Elizabeth C.; Krop, Esmeralda J. M.; Diette, Gregory B.; Aalberse, Rob C.; Smith, Abigail L.; Eggleston, Peyton A.

    2004-01-01

    Although there is evidence that contact with mice is associated with IgE-mediated mouse sensitization and mouse specific antibody responses, the exposure-response relationships remain unclear. To determine whether IgE-mediated mouse sensitization and mouse specific IgG (mIgG) and mIgG4 levels

  14. Effect of biotherapeutics on antitoxin IgG in experimentally induced Clostridium difficile infection

    Directory of Open Access Journals (Sweden)

    S Kaur

    2012-01-01

    Full Text Available Purpose: Recurrent diarrhoea after successful treatment of primary Clostridium difficile associated disease (CDAD occurs due to bowel flora alterations and failure to mount an effective antibody response. Apart from antibiotics, risk factors include immunosuppressive and acid-suppressive drug administration. Biotherapeutics such as probiotic and epidermal growth factor (EGF may offer potential effective therapy for CDAD. Materials and Methods: The effect of biotherapeutics in mounting an antibody response against C. difficile toxins was studied in BALB/c mice challenged with C. difficile after pre-treatment with ampicillin, lansoprazole or cyclosporin. Sera from sacrificed animals were estimated for antitoxin IgG by enzyme linked immunosorbent assay. Results: Antitoxin IgG was significantly higher (P0.05 in animals in which C. difficile was given after pre-treatment with cyclosporin compared to those without any pre-treatment, or pre-treatment with antibiotic or lansoprazole. In inter-subgroup comparisons also significant anomaly in production of antitoxin IgG was found. The antitoxin IgG levels were raised in animals administered C. difficile after pre-treatment with ampicillin, but lower in animals administered cyclosporin. High levels of antitoxin IgG were also found in the serum samples of animals receiving lansoprazole and C. difficile. Conclusions: Probiotics showed their beneficial effect by boosting the immune response as seen by production of antitoxin IgG. Oral administration of EGF did not affect the immune response to C. difficile toxins as significant increase was not observed in the serum antitoxin IgG levels in any of the groups investigated.

  15. Antisporozoite antibodies in mice immunized with irradiation-attenuated Plasmodium berghei sporozoites

    International Nuclear Information System (INIS)

    Hansen, R.; Silva, S.de; Strickland, G.T.

    1979-01-01

    Sera from NMRI/NIH mice were tested for the presence of IgM and IgG anti-sporozoite antibodies using the indirect fluorescent antibody test (IFAT). Both IgM and IgG antibody titres were related to the number of immunizations with irradiation-attenuated Plasmodium berghei sporozoites, and protection from challenge with subsequent non-attenuated sporozoites correlated with the pre-challenge antibody titre. Sera taken five days following challenge showed marked reductions in antibody titres, except for the group receiving the maximum (four) immunizations. Groups immunized with frozen sporozoites or mosquito tissue antigen developed neither antibodies to sporozoites nor protective immunity; nor did animals infected with parasitized blood. However, sera from mice immunized four times with attenuated sporozoites demonstrated IFA titres to blood-stage antigens. The results showed that both IgM and IgG anti-sporozoite antibodies could be detected in mice immunized with attenuated-sporozoites by IFAT, and that the antibody titres correlated with protective immunity. Cross reaction with blood-stage antigens occurred, but the test should still prove useful. (author)

  16. Patch testing and allergen-specific serum IgE and IgG antibodies in the diagnosis of canine adverse food reactions.

    Science.gov (United States)

    Bethlehem, Simone; Bexley, Jennifer; Mueller, Ralf S

    2012-02-15

    Adverse food reaction (AFR) is a common differential diagnosis for pruritic dogs. The only way to diagnose AFR is an elimination diet of 6-8 weeks with a protein and a carbohydrate source not previously fed. In humans, patch testing has been shown to be a useful tool to diagnose food allergies. In veterinary medicine, serum food allergen-specific antibody testing is widely offered to identify suitable ingredients for such diets. The aim of this study was to determine sensitivity, specificity, negative and positive predictability of patch testing with and serum antibody testing for a variety of common food stuffs. Twenty-five allergic dogs underwent an elimination diet and individual rechallenge with selected food stuffs, food patch testing and serum testing for food-antigen specific IgE and IgG. Eleven clinically normal control dogs only were subjected to patch and serum testing. The sensitivity and specificity of the patch test were 96.7 and 89.0% respectively, negative and positive predictability were 99.3 and 63.0%. For IgE and IgG the sensitivity was 6.7 and 26.7%, specificity were 91.4 and 88.3%, the negative predictive values 80.7 and 83.7% and the positive predictive values were 15.4 and 34.8%. Based on these results, a positive reaction of a dog on these tests is not very helpful, but a negative result indicates that this antigen is tolerated well. We conclude that patch testing (and to a lesser degree serum testing) can be helpful in choosing ingredients for an elimination diet in a dog with suspected AFR. Copyright © 2012. Published by Elsevier B.V.

  17. Human anti-luteinizing hormone-releasing hormone antibodies in patients treated with synthetic luteinizing hormone-releasing hormone

    International Nuclear Information System (INIS)

    Meakin, J.L.; Keogh, E.J.; Martin, C.E.

    1985-01-01

    One hundred sixty-three patients who were given synthetic LH-RH therapeutically underwent monitoring of serum IgG anti-LH-RH antibodies. Five of the patients showed specific binding to antibodies. Development of anti-LH-RH antibodies was not limited to those patients with a congenital deficiency of LH-RH. Urticarial responses occurred in four patients, only one of whom had IgG antibodies. Patients who had IgG antibodies or an urticarial response underwent monitoring of their serum IgE anti-LH-RH antibodies, but none had a positive binding response. The refractory state which has been reported in patients in whom similar antibodies to LH-RH develop was not invariably observed among these patients

  18. Immunology of IgG4-related disease

    Science.gov (United States)

    Della-Torre, E; Lanzillotta, M; Doglioni, C

    2015-01-01

    Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition that derives its name from the characteristic finding of abundant IgG4+ plasma cells in affected tissues, as well as the presence of elevated serum IgG4 concentrations in many patients. In contrast to fibrotic disorders, such as systemic sclerosis or idiopathic pulmonary fibrosis in which the tissues fibrosis has remained largely intractable to treatment, many IgG4-RD patients appear to have a condition in which the collagen deposition is reversible. The mechanisms underlying this peculiar feature remain unknown, but the remarkable efficacy of B cell depletion in these patients supports an important pathogenic role of B cell/T cell collaboration. In particular, aberrant T helper type 2 (Th2)/regulatory T cells sustained by putative autoreactive B cells have been proposed to drive collagen deposition through the production of profibrotic cytokines, but definitive demonstrations of this hypothesis are lacking. Indeed, a number of unsolved questions need to be addressed in order to fully understand the pathogenesis of IgG4-RD. These include the identification of an antigenic trigger(s), the implications (if any) of IgG4 antibodies for pathophysiology and the precise immunological mechanisms leading to fibrosis. Recent investigations have also raised the possibility that innate immunity might precede adaptive immunity, thus further complicating the pathological scenario. Here, we aim to review the most recent insights on the immunology of IgG4-RD, focusing on the relative contribution of innate and adaptive immune responses to the full pathological phenotype of this fibrotic condition. Clinical, histological and therapeutic features are also addressed. PMID:25865251

  19. Antibody-dependent cellular cytotoxicity and skin disease

    International Nuclear Information System (INIS)

    Norris, D.A.; Lee, L.A.

    1985-01-01

    Antibody dependent cellular cytotoxicity (ADCC) is a recently described mechanism of immunologic lysis in which cellular targets sensitized by specific antibodies are efficiently and selectively lysed by Fc receptor (FcR) bearing nonspecific effectors. Immunoglobulins of various classes (IgG, IgM, IgA, IgE) and various cellular effectors (large granular lymphocytes, monocyte/macrophages, T lymphocytes, neutrophils, and eosinophils) can induce ADCC in vitro, and the importance of ADCC in vivo is being tested experimentally in resistance to viral, bacterial, and parasitic infection, in tumor surveillance, in allograft rejection, and in inflammatory diseases. There is much indirect evidence that ADCC may be the mechanism of damage of different cellular targets in skin diseases, but the best direct evidence concerns immunologic keratinocyte damage, especially in cutaneous lupus erythematosus (LE). The authors have shown that keratinocytes of several species are highly susceptible to lymphocyte and monocyte-mediated ADCC, but not to neutrophil or eosinophil ADCC in vitro using two different cytotoxicity assays. In contrast, complement was a relatively ineffective mediator of lysis of metabolically intact keratinocyte targets. Patients with certain cutaneous lupus syndromes have serum antibodies capable of inducing monocyte and lymphocyte ADCC of targets coated with extractable nuclear antigens. The authors have shown that these antigens apparently move to the cell membrane of keratinocytes in vitro following ultraviolet irradiation. In an animal model, they have shown that antibodies to SSA/Ro bind to human keratinocytes in vivo, especially after ultraviolet irradiation

  20. 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.

  1. Is perceived intolerance to milk and wheat associated with the corresponding IgG and IgA food antibodies? A cross sectional study in subjects with morbid obesity and gastrointestinal symptoms.

    Science.gov (United States)

    Kvehaugen, Anne Stine; Tveiten, Dag; Farup, Per G

    2018-01-30

    Serum IgG and IgA food antibodies have been used for dietary advice to subjects with gastrointestinal symptoms and perceived food intolerance, but the role of these antibodies in mediating intolerance is controversial. The present study investigated associations between perceived gastrointestinal intolerance to milk-or wheat and the corresponding s-IgG and s-IgA food antibodies in subjects with morbid obesity. Subjects with morbid obesity (BMI ≥ 40 kg/m 2 or ≥35 kg/m 2 with obesity-related complications) were included. Irritable Bowel Syndrome (IBS) was diagnosed based on the Rome III criteria. Severity of specific gastrointestinal symptoms were measured with the Gastrointestinal Symptom Rating Scale (GSRS)-IBS. S-IgG against cow's milk, cheese, wheat and gluten, and s-IgA against casein and gliadin were measured. Ninety-seven subjects (80 females) with mean age 45 (SD 8.4) years were included, 70 had gastrointestinal complaints, 25 had IBS, and 22 and 20 reported milk- and wheat- intolerance respectively. There were no significant differences in serum concentrations or proportions of subjects above defined cut-off values for the antibodies between subjects with and without gastrointestinal complaints. In the group with gastrointestinal complaints, no significant differences were found between subjects with and without perceived food intolerance. Except for a significant correlation between IgG against cheese and GSRS-diarrhea (Rho: -0.25, P = 0.04), no significant correlations were found between the antibodies and type or degree of gastrointestinal symptoms, including IBS. The study showed no associations between perceived milk or wheat intolerance and the corresponding s-IgG and s-IgA food antibodies in subjects with morbid obesity.

  2. Radiometric immunosorbent assay for the detection of anti-hormone-binding protein antibodies

    International Nuclear Information System (INIS)

    Pierce, E.A.; Dame, M.C.; DeLuca, H.F.

    1986-01-01

    A radiometric immunosorbent assay (RISA) for the detection of monoclonal antibodies to hormone-binding proteins has been developed. The assay involves incubating hybridoma supernatants in microtiter wells that have been coated with goat anti-mouse IgG antibodies. Any mouse IgG in the test supernatant is thus specifically retained in the wells. Radioactive ligand-binding protein complexes are then incubated in the wells. The presence of anti-binding protein antibodies in the supernatant is indicated by specific retention of radioactive ligand-binding protein complexes in the wells. Crude antigen preparations, such as tissue homogenates, can be used to detect antibodies. The assay is capable of detecting antibody at concentrations 20 ng/ml (approx. 100 pM IgG). The RISA has been used successfully to screen for monoclonal antibodies to the intracellular receptor for 1,25-dihydroxyvitamin D 3 and should be useful for the detection of antibodies to ligand-binding proteins in general

  3. Antibodies Against Hypocretin Receptor 2 Are Rare in Narcolepsy.

    Science.gov (United States)

    Giannoccaro, Maria Pia; Waters, Patrick; Pizza, Fabio; Liguori, Rocco; Plazzi, Giuseppe; Vincent, Angela

    2017-02-01

    Recently, antibodies to the hypocretin receptor 2 (HCRTR2-Abs) were reported in a high proportion of narcolepsy patients who developed the disease following Pandemrix® vaccination. We tested a group of narcolepsy patients for the HCRTR2-Abs using a newly established cell-based assay. Sera from 50 narcolepsy type 1 (NT1) and 11 narcolepsy type 2 (NT2) patients, 22 patients with other sleep disorders, 15 healthy controls, and 93 disease controls were studied. Cerebrospinal fluid (CSFs) from three narcoleptic patients were subsequently included. Human embryonic kidney cells were transiently transfected with human HCRTR2, incubated with patients' sera for 1 hr at 1:20 dilution and then fixed. Binding of antibodies was detected by fluorescently labeled secondary antibodies to human immunoglobulin G (IgG) and the different IgG subclasses. A nonlinear visual scoring system was used from 0 to 4; samples scoring ≥1 were considered positive. Only 3 (5%) of 61 patients showed a score ≥1, one with IgG1- and two with IgG3-antibodies, but titers were low (1:40-1:100). CSFs from these patients were negative. The three positive patients included one NT1 case with associated psychotic features, one NT2 patient, and an NT1 patient with normal hypocretin CSF levels. Low levels of IgG1 or IgG3 antibodies against HCRTR2 were found in 3 of 61 patients with narcolepsy, although only 1 presented with full-blown NT1. HCRTR2-Abs are not common in narcolepsy unrelated to vaccination. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  4. Diagnosis and Treatment of IgG4-Related Disease.

    Science.gov (United States)

    Kamisawa, Terumi; Okazaki, Kazuichi

    2017-01-01

    It is critical to differentiate IgG4-related disease (IgG4-RD) from malignant tumor and similar disease of the affected organ to apply appropriate therapy and avoid unnecessary surgery. IgG4-RD is diagnosed on combination of typical radiological findings; elevation of serum IgG4 levels; histopathological findings of abundant infiltration of IgG4-positive plasma cells and lymphocytes, storiform fibrosis , and obliterative phlebitis ; association with other IgG4-related diseases; and response to steroids. Histopathological approach is particularly recommended. Systemic glucocorticoids are currently the first-line approach for IgG4-RD, and the indications are symptoms. The initial recommended dose of oral prednisolone for induction of remission is 0.6 mg/kg/day, administered for 2-4 weeks. This dose is gradually tapered to a maintenance dose of 2.5-5 mg/day over a period of 2-3 months. As IgG4-RD sometimes relapses after steroids, maintenance therapy is usually performed in Japan. However, as IgG4-RD patients are typically elderly and are at high risk of developing steroid-related complications, cessation of the medication should be attempted at least within 3 years. For relapsed IgG4-RD, re-administration or dose up of steroid is effective, but the addition of immunomodulatory drugs such as azathioprine has been considered to be appropriate. B cell depletion with rituximab (an anti-CD20 antibody) is effective, even in many patients in whom treatment with immunomodulatory drugs was unsuccessful. The short-term clinical, morphological, and functional outcomes of most IgG4-RD patients treated with steroid therapy are good, but the long-term outcomes are less clear due to several unknown factors such as relapse, developed fibrosis, and associated malignancy.

  5. New Insights into the Functional Behavior of Antibodies as Revealed by Binding Studies on an Anti-Uranium Monoclonal Antibody

    International Nuclear Information System (INIS)

    Blake, Diane A.; Xia Li; Haini Yu; Blake, Robert C.

    2004-01-01

    of the molecule. The addition of protein G, a bacterial protein that also binds to the Fc portion of mouse IgG, to the covalently modified 8A11 produced an antibody preparation that showed a lower affinity for U(VI)-DCP than that observed in the absence of protein G. This protein G-dependent decrease in the affinity of 8A11for U(VI)-DCP was dose-dependent. Similarly, U(VI)-DCP was observed to decrease the affinity between 8A11 and protein G, also in a dose-dependent manner. These reciprocal binding effects between protein G and U(VI)-DCP were taken as further evidence that binding to the Fc portion on the intact 8A11 antibody could influence the strength of the interaction at the antigen binding sites on the Fab portions of the protein, and vice versa. These practical, development-driven binding experiments have revealed a fundamental facet of antibody functional behavior that appears to have been largely unnoticed. The binding phenomena described for the first time in this report may have physiological relevance and can be purposefully exploited to improve the sensitivity and utility of selected immunoassays.

  6. The effect of treatment on the age-antibody relationship in children infected with Schistosoma mansoni and Schistosoma haematobium

    Directory of Open Access Journals (Sweden)

    Mutapi Francisca

    2002-01-01

    Full Text Available The effect of praziquantel treatment on the age-antibody relationship was studied in 174 children aged between 6 and 17 years from a schistosome endemic area in Zimbabwe. The children were co-infected with Schistosoma mansoni and S. haematobium with infection prevalences of 74% and 53% respectively. Antibody levels for the isotypes IgA, IgE, IgM, IgG1, IgG2, IgG3 and IgG4, directed against soluble egg antigen were measured using an indirect ELISA assay. Treatment resulted in a significant increase in levels of IgG2 and IgG3 while levels of IgA decreased significantly. In untreated children there were significant decreases in levels of IgG4. Treatment also resulted in significant alteration in the age-antibody profiles for the isotypes IgE, IgM, IgG1 and IgG2 in treated children but not in untreated children. The results are discussed in the context of factors believed to give rise to the age-antibody relationship; i.e. age-related exposure patterns, age-related development of acquired immunity, age-related hormonal changes and age-related changes in innate susceptibility to infection.

  7. 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.

  8. TOXOPLASMA AND VIRAL ANTIBODIES AMONG HIV PATIENTS AND INMATES IN CENTRAL JAVA, INDONESIA.

    Science.gov (United States)

    Sari, Yulia; Haryati, Sri; Raharjo, Irvan; Prasetyo, Afiono Agung

    2015-11-01

    In Indonesia, Toxoplasma and its associations with blood-borne viruses have been poorly studied. In order to study the association between anti-Toxoplasma antibodies and blood-borne viral antibodies, blood samples from 497 participants (375 inmates from four prisons in Central Java, Indonesia and 122 HIV patients at a Voluntary Counseling and Testing Clinic in Surakarta, Indonesia) were tested for serological markers of Toxoplasma, human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and human T-lymphotropic virus types I and II (HTLV-1/2). Anti-Toxoplasma IgG and IgM positivity rates were 41.6% and 3.6%, respectively. One point two percent of participants was positive for both anti-Toxoplasma IgG and IgM antibodies. Sixteen point five percent, 11.3%, 2.6% and 2.8% of participants were positive for anti- Toxoplasma IgG combined with anti-HCV antibodies, anti-Toxoplasma IgG combined with anti-HIV antibodies, anti-Toxoplasma IgM combined with anti-HIV antibodes and anti-Toxoplasma IgG combined with both anti-HIV and anti-HCV antibodies, respectively. Anti-Toxoplasma IgM seropositivity was associated with anti-HIV (aOR = 4.3; 95% CI: 1.112-16.204, p = 0.034). Anti-Toxoplasma IgG antibodies were associated with anti-HCV (aOR = 2.8; 95% CI: 1.749-4.538, p < 0.001) and history of injection drug use (aOR = 3.1; 95% CI: 1.905-5.093, p < 0.001). In conclusion, we recommend patients with HIV, HCV infection and injection drug users should be screened for Toxoplasma infection in Indonesia.

  9. A Label-Free Immunosensor for IgG Based on an Extended-Gate Type Organic Field Effect Transistor

    Directory of Open Access Journals (Sweden)

    Tsukuru Minamiki

    2014-09-01

    Full Text Available A novel biosensor for immunoglobulin G (IgG detection based on an extended-gate type organic field effect transistor (OFET has been developed that possesses an anti-IgG antibody on its extended-gate electrode and can be operated below 3 V. The titration results from the target IgG in the presence of a bovine serum albumin interferent, clearly exhibiting a negative shift in the OFET transfer curve with increasing IgG concentration. This is presumed to be due an interaction between target IgG and the immobilized anti-IgG antibody on the extended-gate electrode. As a result, a linear range from 0 to 10 µg/mL was achieved with a relatively low detection limit of 0.62 µg/mL (=4 nM. We believe that these results open up opportunities for applying extended-gate-type OFETs to immunosensing.

  10. Asma y deficiencia de subclases de IgG Asthma and IgG subclases deficiency

    Directory of Open Access Journals (Sweden)

    Lucía Santamaría Ortiz

    1995-04-01

    G deficiency was found in four steroid. dependent patients. Serum levels of IgG subclasses 1 to 4 were measured by means of a sandwich-like ELISA with specific monoclonal antibodies. One or more subclass deficiencies were present In 55.6% of the patients. Significant differences were not found between the following groups: steroid and nonsteroid dependent patients; allergic or intrinsic, asthma; and individuals with or without history of infection. IgG 1 deficiency was the most commonly found: It was present in 46.7% of the patients, either as an isolated disorder or combined with alteration of other subclasses. Deficiency of other subclasses was present in the following proportions: 31.1% for IgG2; 24.4% for IgG3 and 17.8 for IgG4. The high incidence of subclass deficiency may be due to steroid action or to primary Immune defects leading to disorders of IgG synthesis. Such situation might be responsible for the aggressive behavior of the disease.

  11. Increased levels of anti-non-Gal IgG following pig-to-baboon bone marrow transplantation correlate with failure of engraftment

    Science.gov (United States)

    Liang, Fan; Wamala, Isaac; Scalea, Joseph; Tena, Aseda; Cormack, Taylor; Pratts, Shannon; Struuck, Raimon Duran; Elias, Nahel; Hertl, Martin; Huang, Christene A.; Sachs, David H.

    2013-01-01

    Background The development of genetically modified pigs which lack the expression of alpha 1–3 galactosyl transferase, (GalT-KO pigs) has facilitated the xenogeneic transplantation of porcine organs and tissues into primates by avoiding hyperacute rejection due to pre-existing antibodies against the Gal epitope. However, antibodies against other antigens (anti-non-Gal antibodies), are found at varying levels in the pre-transplant sera of most primates. We have previously found that baboons with high levels of pre-transplant anti-non-Gal IgG, conditioned with a non-myeloablative conditioning regimen, failed to engraft following pig-to-baboon bone marrow transplantation [8]. Two baboons with low levels of pre-transplant anti-non-Gal IgG, conditioned with the same regimen, showed porcine bone marrow progenitors at 28 days following transplantation, suggesting engraftment. These baboons also showed evidence of donor-specific hypo-responsiveness. This observation led us to investigate the hypothesis that selecting for baboon recipients with low pre-transplant anti-non-Gal IgG levels might improve engraftment levels following GalT-KO pig-to-baboon bone marrow transplantation. Methods Five baboons, with low pre-transplant anti-non-Gal IgG levels, received transplantation of bone marrow cells (1–5 × 10^9/kg of recipient weight) from GalT-KO pigs. They received a non-myeloablative conditioning regimen consisting of low-dose total body irradiation (150cGy), thymic irradiation (700cGy), anti-thymocyte globulin (ATG) and tacrolimus. In addition, two baboons received Rituximab and Bortezomib (Velcade) treatment as well as extra-corporeal immunoadsorption using GalT-KO pig livers. Bone marrow engraftment was assessed by porcine-specific PCR on colony forming units (CFU) of day 28 bone marrow aspirates. Anti-non-Gal antibody levels were assessed by serum binding towards GalT-KO PBMC using flow cytometry (FACS). Peripheral macro-chimerism was measured by FACS using pig and

  12. Antigen-Specific Antibody Glycosylation Is Regulated via Vaccination

    NARCIS (Netherlands)

    Mahan, Alison E.; Jennewein, Madeleine F.; Suscovich, Todd; Dionne, Kendall; Tedesco, Jacquelynne; Chung, Amy W.; Streeck, Hendrik; Pau, Maria; Schuitemaker, Hanneke; Francis, Don; Fast, Patricia; Laufer, Dagna; Walker, Bruce D.; Baden, Lindsey; Barouch, Dan H.; Alter, Galit

    2016-01-01

    Antibody effector functions, such as antibody-dependent cellular cytotoxicity, complement deposition, and antibody-dependent phagocytosis, play a critical role in immunity against multiple pathogens, particularly in the absence of neutralizing activity. Two modifications to the IgG constant domain

  13. Characterization of antibody response in neuroinvasive infection caused by Toscana virus.

    Science.gov (United States)

    Pierro, A; Ficarelli, S; Ayhan, N; Morini, S; Raumer, L; Bartoletti, M; Mastroianni, A; Prati, F; Schivazappa, S; Cenni, P; Vocale, C; Rossini, G; Gaibani, P; Sambri, V; Landini, M P; Lewis, R E; Charrel, R N; Varani, S

    2017-11-01

    Among sandfly-borne pathogens, Toscana virus (TOSV) is a prominent cause of summer meningitis in Mediterranean Europe. Here, we assessed the kinetics of anti-TOSV antibodies over time in 41 patients diagnosed with TOSV meningitis or meningoencephalitis in northeastern Italy. Acute and follow-up serum samples were collected up to 20 months after diagnosis of TOSV infection and tested for the presence of specific antibody using immunoenzymatic and indirect immunofluorescence assays. In addition, maturation of anti-TOSV IgG over time was evaluated as well as production of neutralizing antibodies. Specific IgM and IgG response was present at diagnosis in 100% of patients; TOSV-specific IgM and IgG were detected in patients' sera up to 6 and 20 months after diagnosis, respectively. The avidity index (AI) increased over the first month after infection in 100% of patients and most cases exceeded 60% by Day 30 post infection. The AI subsequently plateaued then declined at 20 months after diagnosis. Finally, neutralization assay to TOSV was performed in 217 sera collected from 41 patients; 69.6% of tested samples resulted in reactive and moderate levels of neutralizing antibodies observed during all phases of infection despite high titres of total anti-TOSV IgG. Specific antibody response develops rapidly and is long-lasting for neuroinvasive TOSV infection. Serodiagnosis of neuroinvasive TOSV requires simultaneous detection of specific IgM and IgG. Moderate levels of neutralizing antibodies were maintained over the study period, while the protective role of antibodies lacking neutralizing activity is unclear and requires further evaluation. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  14. Serum IgG2 and tissue IgG2 plasma cell elevation in orbital IgG4-related disease (IgG4-RD): Potential use in IgG4-RD assessment.

    Science.gov (United States)

    Chan, Anita S Y; Mudhar, Hardeep; Shen, Sunny Yu; Lang, Stephanie S; Fernando, Malee; Hilmy, Maryam Hazly; Guppy, Naomi Jayne; Rennie, Ian; Dunkley, Lisa; Al Jajeh, Issam

    2017-11-01

    To determine the role of serum and tissue IgG2 in orbital biopsies with the histological features of IgG4-related disease (IgG4-RD) in comparison with non-IgG4-related orbital inflammatory disorders (OID), including autoimmune disorders. This is an international (Sheffield, UK, and Singapore) collaborative, retrospective case review of 69 patients (38 from Singapore National Eye Centre and 31 from Royal Hallamshire Hospital, Sheffield) with orbital inflammatory biopsies between 2002 and 2016. Clinical information and histology were reviewed and cases were classified into three groups: Group 1: IgG4-RD orbital inflammation (n=43); Group 2: idiopathic OID (n=12) and Group 3: autoimmune OID (n=14). Serum IgG1, IgG2, IgG3 and IgG4 levels were collated where available and immunohistochemistry (IHC) for tissue IgG2 plasma cells was performed. Dual IHC showed IgG2 plasma cells as a distinct population from IgG4 plasma cells. Significant (twofold) serum IgG2 elevation was noted among IgG4-RD (group 1), idiopathic (group 2) and autoimmune OID (group 3). Similarly, significant elevation of tissue IgG2 plasma cells was also seen among IgG4-RD (group 1), idiopathic and autoimmune OID (groups 2 and 3). Significant elevations of serum IgG2 and tissue IgG2 plasma cells are present in orbital IgG4-RD in comparison with non-IgG4 orbital inflammation (idiopathic and autoimmune OID), suggesting that IgG2 may play a role in IgG4-RD. A serum IgG2 cut-off >5.3 g/L was found to be 80% sensitive and 91.7% specific for orbital IgG4-RD, with an accuracy of 0.90. Tissue IgG2 and IgG4 subclass reporting may provide additional insight regarding the 'IgG4-RD' pathogenesis. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Seropositivity of Dengue Antibodies during Pregnancy

    Directory of Open Access Journals (Sweden)

    Nor Azlin Mohamed Ismail

    2014-01-01

    Full Text Available Purpose. Malaysia a dengue endemic country with dengue infections in pregnancy on the rise. The present study was aimed at determining dengue seroprevalence (IgG or IgM during pregnancy and its neonatal transmission in dengue seropositive women. Methods. Maternal with paired cord blood samples were tested for dengue antibodies (IgG and IgM using an enzyme-linked immunosorbent assay (ELISA. Maternal age, parity, occupation, ethnic group, and gestational age were recorded. Data on neonatal Apgar score and admissions to the Neonatal Intensive Care Unit (NICU were analyzed. Results. Out of 358 women recruited, about 128 (35.8% patients were seropositive. Twelve patients (3.4% had recent infections (IgM positive and another 116 women (32.4% were with past infections (IgG positive. All babies born to seropositive mothers had positive IgG paired cord blood; however, no IgM seropositivity was observed. All neonates had good Apgar scores and did not require NICU admission. Conclusion. In this study, 35.8% pregnant women were found to be dengue seropositive. However, transplacental transfer of IgG antibodies had no detrimental effect on the neonatal outcomes.

  16. [EFFICACY OF IVIG TREATMENT IN BRONCHIECTASIS ASSOCIATED WITH IGG SUBCLASS DEFICIENCY].

    Science.gov (United States)

    Shostak, Yael; Kramer, Mordechai R

    2017-11-01

    Bronchiectasis is characterized by an abnormal dilatation of the bronchi leading to a chronic inflammatory process, airway blockage and impaired clearance of secretions. The damage to the airways is usually progressive and is the result of several pathogenic processes. In the past, healing of infections (especially pulmonary tuberculosis) was the main cause of airway dilatation and progression of chronic inflammation. Today, congenital illnesses, anatomical defects and immune deficiency play an important role in the pathogenesis of bronchiectasis formation. The immunoglobulin repertoire is vital for effective host protection against a wide variety of pathogens. Primary antibody deficiency diseases are defects of the humoral arm of the immune system and involve an absence/reduced levels of one or more immunoglobulin classes/subclasses or defects of specific antibody formation. Immunoglobulin G (IGG) subclass deficiency can occur in a healthy person and could be without clinical significance. However, in recent years there is emerging evidence that in patients with recurrent infections, early diagnosis of antibody deficiency affects the prognosis and prevention of ongoing lung damage. The use of IVIG has contributed significantly to the survival rate in primary antibody deficiencies. There is limited literature on the treatment of IVIG for patients with IGG subclass deficiency. However, all studies presented so far demonstrated that immunoglobulin therapy reduced the rate of bacterial infections, days of antibiotic usage, hospital admissions and significantly increased patients' quality of life. Therefore, in the appropriate clinical setting, ie: a patient with bronchiectasis and recurrent infections, it is justified to test whether there are humoral immune defects such as IGG subclass deficiency. In a patient with proven deficiency, we should recommend to start IVIG treatment until clinical benefit is achieved.

  17. Viral control in chronic HIV-1 subtype C infection is associated with enrichment of p24 IgG1 with Fc effector activity.

    Science.gov (United States)

    Chung, Amy; Makuba, Jenniffer M; Ndlovu, Bongiwe; Licht, Anna; Robinson, Hannah; Ramlakhan, Yathisha; Ghebremichael, Musie; Reddy, Tarylee; Goulder, Philip; Walker, Bruce; Ndung'u, Thumbi; Alter, Galit

    2018-04-03

    Postinfection HIV viral control and immune correlates analysis of the RV144 vaccine trial indicate a potentially critical role for Fc receptor-mediated antibody functions. However, the influence of functional antibodies in clade C infection is largely unknown. Plasma samples from 361 chronic subtype C-infected, antiretroviral therapy-naïve participants were tested for their HIV-specific isotype and subclass distributions, along with their Fc receptor-mediated functional potential. Total IgG, IgG subclasses and IgA binding to p24 clade B/C and gp120 consensus C proteins were assayed by multiplex. Antibody-dependent uptake of antigen-coated beads and Fc receptor-mediated natural killer cell degranulation were evaluated as surrogates for antibody-dependent cellular phagocytosis (ADCP) and antibody-dependent cellular cytotoxicity (ADCC), respectively. p24 IgG1 was the only subclass associated with viral control (P = 0.01), with higher p24-specific ADCP and ADCC responses detected in individuals with high p24 IgG1. Although p24 IgG1 levels were enriched in patients with elevated Gag-specific T-cell responses, these levels remained an independent predictor of low-viral loads (P = 0.04) and high CD4 counts (P = 0.004) after adjusting for Gag-specific T-cell responses and for protective HLA class I alleles. p24 IgG1 levels independently predict viral control in HIV-1 clade C infection. Whether these responses contribute to direct antiviral control via the recruited killing of infected cells via the innate immune system or simply mark a qualitatively superior immune response to HIV, is uncertain, but highlights the role of p24-specific antibodies in control of clade C HIV-1 infection.

  18. New radioimmunoassay for IgM and IgG rheumatoid factors, based on a double antibody method

    Energy Technology Data Exchange (ETDEWEB)

    Nordfang, O. (Rigshospitalet, Copenhagen (Denmark)); Hoeier-Madsen, M.; Lieberkind, J. (Statens Seruminstitut, Copenhagen (Denmark)); Halberg, P. (Medical Department, Division of Rheumatology, Hvidovre Hospital, Hvidovre, Denmark)

    1981-11-30

    A new radioimmunoassay has been developed for measuring IgM and IgG rheumatoid factors. Diluted sera from donors and patients were incubated with immunoprecipitates prepared from sheep serum and rabbit anti-sheep IgG antiserum. The precipitates were washed, and radioiodinated rabbit F(ab')/sub 2/ fragments specific for human IgM or IgG were added. The precipitates were isolated by filtration and measured in a gamma counter. With this assay IgM rheumatoid factors were detected in sera from all patients with seropositive rheumatoid arthritis and in sera from 40% of patients with seronegative rheumatoid arthritis. IgG rheumatoid factors were found in sera from 68% of the seropositive and 40% of the seronegative patients. Gel filtration experiments demonstrated that it is possible to detect monomeric IgG rheumatoid factors and IgM rheumatoid factors of molecular weight smaller than pentameric IgM. Furthermore it has been shown that IgG rheumatoid factor activity is still present after reduction of IgM rheumatoid factors with dithiotreitol.

  19. Comparative studies on Fc receptors for IgG on resting and activated T lymphocytes

    International Nuclear Information System (INIS)

    Hueckel, C.; Jensen, H.L.; Rychly, J.; Sandor, M.; Erdei, A.; Gergely, J.

    1986-01-01

    Fc-receptors for IgG (FcγR) on resting (i.e. freshly prepared) and mitogen (Con A) or alloantigen-activated mouse spleen T cells were compared using binding of different markers such as 125 I-labelled immune complexes, 125 I-labelled anti FcγR monoclonal antibody, FITC-labelled aggr. IgG and sheep erythrocytes covered with specific antibody (EA rosetting). C3b receptors were detected by rosetting with sheep erythrocytes covered with antibody and complement (EAC rosetting). The electrophoretic mobility of the cells without or after binding of aggr. IgG was also tested. Differences between resting and activated T cells were found: (1) After activation of T cells by mitogen or alloantigen, a proportion of FcγR-positive cells increased two to four times. (2) FcγR number per FcγR-positive cell seemed to be higher on activated then on resting cells. (3) FcγR-positive resting cells did not shed their FcγR upon incubation at 4 0 C followed by incubation at 37 0 C, but FcγR-positive activated cells shed a remarkable proportion of their FcγR on the same conditions. (4) Binding of aggr. IgG caused a decrease of electrophoretic mobility of activated but not resting cells. (5) FcγR-positive resting cells were also C3b receptor-positive, whereas FcγR-positive activated cells had no detectable C3b receptors. (author)

  20. Effect of antibody charge and concentration on deposition of antibody to glomerular basement membrane

    International Nuclear Information System (INIS)

    Madaio, M.P.; Salant, D.J.; Adler, S.; Darby, C.; Couser, W.G.

    1984-01-01

    Fixed anionic sites within the glomerular capillary wall influence the permeation of serum proteins, the localization of various antigens, and the deposition of antibody in the subepithelial space. In anti-GBM nephritis antibody deposition occurs very rapidly to antigenic sites located relatively proximal in the glomerular capillary wall. The authors examined the influence of the glomerular charge barrier on anti-GBM antibody deposition by comparing the rate of deposition of antibodies with cationic and anionic isoelectric points. Purified sheep anti-rat GBM IgG was isolated from acid eluates of kidneys obtained 24 hr after rats were injected with sheep antiserum to rat GBM. Anti-GBM IgG was separated into cationic (pI 6.4-8.5) and anionic (pI 4.2-6.8) fractions, which were radiolabelled with 131 I and 125 I, respectively, shown to have equal antibody contents measured by in vitro binding to normal glomeruli, mixed in equal amounts, and injected in incremental doses to ten rats. At 1 hr the glomerular antibody binding of each fraction was directly related to the blood level (r . 0.95, r . 0.97) and delivery of antibody (r . 0.98, r . 0.98). Glomerular binding of cationic antibody was four times greater than anionic antibody over the entire range of deliveries studied (P less than 0.001). The authors conclude that glomerular deposition of anti-GBM antibody is directly related to blood concentration and delivery of antibody. Furthermore, the deposition of cationic antibodies to GBM antigens was significantly greater than the deposition of anionic antibodies

  1. The Malaria Vaccine Candidate GMZ2 Elicits Functional Antibodies in Individuals From Malaria Endemic and Non-Endemic Areas

    DEFF Research Database (Denmark)

    Jepsen, Micha Phill Grønholm; Jogdand, Prajakta S; Singh, Susheel K

    2013-01-01

    against Plasmodium falciparum. Results. We showed that the maximum level of immunoglobulin G (IgG) antibodies obtained by GMZ2 vaccination is independent of ethnicity, time under malaria-exposure, and vaccine dose and that GMZ2 elicits high levels of functionally active IgG antibodies. Both, malaria......-naive adults and malaria-exposed preschool children elicit vaccine-specific antibodies with broad inhibitory activity against geographically diverse P. falciparum isolates. Peptide-mapping studies of IgG subclass responses identified IgG3 against a peptide derived from MSP3 as the strongest predictor...

  2. Kinetics of intralymphatically delivered monoclonal antibodies

    International Nuclear Information System (INIS)

    Wahl, R.L.; Geatti, O.; Liebert, M.; Beers, B.; Jackson, G.; Laino, L.; Kronberg, S.; Wilson, B.S.; Beierwaltes, W.H.

    1985-01-01

    Radiolabeled monoclonal antibody (MoAb) administration subcutaneously (sq), so that preferential uptake is to the lymphatics, holds significant promise for the detection of lymph node metastases. Only limited information is available about clearance rates of intralymphatically administered MoAbs. I-131 labeled intact IgG (225.28S), F(ab's)2 (225.28S) or IgM (FT162) were administered sq to anesthetized Balb/C mice. Eight mice were studied with each MoAb, 4 with a foot-pad injection, 4 with an anterior abdominal injection. Gamma camera images were collected into a computer, over the first 6 hrs after injection with the animals anesthetized and immobile. Animals were then allowed to move about freely. Additional images were then acquired out to 48 hrs. Regions of interest wre selected over the injection site and the kinetics of antibody egress determined. Clearance rates from local sq injection sites are influenced by motion and somewhat by location. The class and fragment status of the MoAb appear relatively less important in determining clearance rates from sq injections than they are in determining whole-body clearance after iv injections. Additional studies using Fab fragments and additional monoclonals will be useful in extending these observations

  3. Evaluation of Salivary Antibodies to Detect Infection with Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Mark B Loeb

    1997-01-01

    Full Text Available Helicobacter pylori infection is an important cause of peptic ulcer disease and chronic gastritis. Infection with this bacterium stimulates the production of immunoglobulin (Ig G antibody. Salivary IgG antibody tests to detect H pylori infection offer a convenient and noninvasive method of diagnosis. To evaluate an IgG salivary antibody kit, saliva was collected from 157 out-patients with dyspepsia referred for endoscopy to a tertiary centre. A salivary IgG ELISA antibody assay was performed using the Helisal Helicobacter pylori (IgG assay kit, and at least four gastric biopsies were obtained. H pylori infection was confirmed by demonstration of the organism on Warthin-Starry silver stain (sensitivity 85%, specificity 55%. The prevalence of infection with H pylori was 30%. When the analysis was redone, excluding those treated with eradication therapy, the results were similar (sensitivity 86%, specificity 58%. The positive predictive value of the assay was 45% and the negative predictive value was 90%. Despite the ease of sampling, the assay used has limited diagnostic utility, lacking the predictive value to indicate which patients referred with dyspeptic symptoms to a tertiary care setting are infected with H pylori.

  4. Improved radioimaging and tumor localization with monoclonal F(ab')2

    International Nuclear Information System (INIS)

    Wahl, R.L.; Parker, C.W.; Philpott, G.W.

    1983-01-01

    Monoclonal anti-tumor antibodies have great promise for radioimmunodetection and localization of tumors. Fab and F(ab')2 fragments, which lack the Fc fragment of antibody (Ab), are cleared more rapidly from the circulation and may have less nonspecific tissue binding than intact Ab. In radioimaging studies using a murine monoclonal antibody to carcinoembryonic antigen in a human colon carcinoma xenografted into hamsters, F(ab')2 fragments were shown superior to Fab fragments and intact antibody for scintiscanning. In double-label experiments with anti-CEA antibody and control monoclonal IgG, F(ab')2 fragments were found to give better and more rapid specific tumor localization than intact antibody or Fab fragments. F(ab')2 fragments offer significant promise for tumor imaging and possibly therapy

  5. Cytokine profiles and antibody responses to Plasmodium falciparum ...

    African Journals Online (AJOL)

    Estimated higher ratios of IFN-γ/IL-10 and IFN-γ/IL-12 were also observed in the symptomatic children while the asymptomatic controls had higher IL-12/IL-10 ratio. The mean concentration levels of anti-P. falciparum IgG1, IgG2, IgG3 antibodies were statistically significantly higher in the individuals >5 years of age than <5 ...

  6. Separation of hemagglutination-inhibiting immunoglobulin M antibody to rubella virus in human serum by high-performance liquid chromatography.

    OpenAIRE

    Kobayashi, N; Suzuki, M; Nakagawa, T; Matumoto, M

    1986-01-01

    High-performance liquid chromatography was successfully used to separate hemagglutination-inhibiting immunoglobulin M (IgM) rubella virus antibody from IgG rubella virus antibody in human serum. The fractionation by high-performance liquid chromatography was as effective as sucrose density gradient centrifugation in separating IgM antibody from IgG antibody.

  7. Antilymphocytic antibodies and marrow transplantation. VIII. Recipient conditioning with Clq-affine monoclonal anti-pan T antibodies prevents GVHD in homozygous fully mismatched mice

    International Nuclear Information System (INIS)

    Thierfelder, S.; Kummer, U.; Schuh, R.; Mysliwietz, J.

    1986-01-01

    An approach to suppressing secondary disease with antibodies was studied that differed from conventional antibody treatment of donor marrow in vitro. It consisted of the selection of anti-Thy-1 antibodies with high affinity for Clq, the first subunit of the complement cascade, and a single injection of such antibodies into prospective irradiated marrow recipients. Monoclonal mouse IgM and rat IgG 2c antibodies of high titers in complement-dependent test systems but with low affinity for Clq caused little immunosuppression. Monoclonal rat IgG2b or mouse IgG2a anti-Thy-1 antibodies with high affinity for Clq prevented acute and chronic mortality of graft-v-host disease (GVHD), however, when injected in irradiated CBA or AKR mice prior to C57BL/6 spleen and/or bone marrow cell transfusion. This treatment simultaneously suppressed residual host-v-graft reactivity of the irradiated mice, so that permanent hematopoietic engraftment ensued even at 5 or 6 Gy. Full chimerism and specific tolerance were obtained. Primary immune response to SRBC was clearly depressed in the chimeras; secondary immune response was not. Clearance of T cell antibody activity (greater than 6 days), timing, and dose of injected antibody, as well as other modalities of the conditioning treatment that may have contributed to the remarkable immunosuppression, are discussed

  8. Demonstration of carbohydrate-specific immunoglobulin G4 antibodies in sera of patients receiving grass pollen immunotherapy

    NARCIS (Netherlands)

    van Ree, R.; Aalberse, R. C.

    1995-01-01

    From a group of 92 patients receiving grass pollen immunotherapy, and selected on grounds of high IgG4 titers against Lol p I, sera were tested for IgG4 antibodies against the glycosylated grass pollen allergen Lol p XI. In 72 of 92 cases IgG4 antibodies were demonstrated. The N-glycan of Lol p XI

  9. Efficient generation of monoclonal antibodies from single rhesus macaque antibody secreting cells.

    Science.gov (United States)

    Meng, Weixu; Li, Leike; Xiong, Wei; Fan, Xuejun; Deng, Hui; Bett, Andrew J; Chen, Zhifeng; Tang, Aimin; Cox, Kara S; Joyce, Joseph G; Freed, Daniel C; Thoryk, Elizabeth; Fu, Tong-Ming; Casimiro, Danilo R; Zhang, Ningyan; A Vora, Kalpit; An, Zhiqiang

    2015-01-01

    Nonhuman primates (NHPs) are used as a preclinical model for vaccine development, and the antibody profiles to experimental vaccines in NHPs can provide critical information for both vaccine design and translation to clinical efficacy. However, an efficient protocol for generating monoclonal antibodies from single antibody secreting cells of NHPs is currently lacking. In this study we established a robust protocol for cloning immunoglobulin (IG) variable domain genes from single rhesus macaque (Macaca mulatta) antibody secreting cells. A sorting strategy was developed using a panel of molecular markers (CD3, CD19, CD20, surface IgG, intracellular IgG, CD27, Ki67 and CD38) to identify the kinetics of B cell response after vaccination. Specific primers for the rhesus macaque IG genes were designed and validated using cDNA isolated from macaque peripheral blood mononuclear cells. Cloning efficiency was averaged at 90% for variable heavy (VH) and light (VL) domains, and 78.5% of the clones (n = 335) were matched VH and VL pairs. Sequence analysis revealed that diverse IGHV subgroups (for VH) and IGKV and IGLV subgroups (for VL) were represented in the cloned antibodies. The protocol was tested in a study using an experimental dengue vaccine candidate. About 26.6% of the monoclonal antibodies cloned from the vaccinated rhesus macaques react with the dengue vaccine antigens. These results validate the protocol for cloning monoclonal antibodies in response to vaccination from single macaque antibody secreting cells, which have general applicability for determining monoclonal antibody profiles in response to other immunogens or vaccine studies of interest in NHPs.

  10. A Model System for Concurrent Detection of Antigen and Antibody Based on Immunological Fluorescent Method

    Directory of Open Access Journals (Sweden)

    Yuan-Cheng Cao

    2015-01-01

    Full Text Available This paper describes a combined antigen/antibody immunoassay implemented in a 96-well plate using fluorescent spectroscopic method. First, goat anti-human IgG was used to capture human IgG (model antigen; goat anti-human IgG (Cy3 or FITC was used to detect the model antigen; a saturating level of model antigen was then added followed by unlabelled goat anti-human IgG (model antibody; finally, Cy3 labelled rabbit anti-goat IgG was used to detect the model antibody. Two approaches were applied to the concomitant assay to analyze the feasibility. The first approach applied FITC and Cy3 when both targets were present at the same time, resulting in 50 ng/mL of the antibody detection limit and 10 ng/mL of antigen detection limit in the quantitative measurements of target concentration, taking the consideration of FRET efficiency of 68% between donor and acceptor. The sequential approach tended to lower the signal/noise (S/N ratio and the detection of the model antigen (lower than 1 ng/mL had better sensitivity than the model antibody (lower than 50 ng/mL. This combined antigen/antibody method might be useful for combined detection of antigens and antibodies. It will be helpful to screen for both antigen and antibody particularly in the situations of the multiserotype and high-frequency mutant virus infections.

  11. Analysis of Tn antigenicity with a panel of new IgM and IgG1 monoclonal antibodies raised against leukemic cells

    DEFF Research Database (Denmark)

    Blixt, Klas Ola; Lavrova, Olga I; Mazurov, Dmitriy V

    2012-01-01

    antigenicity remain poorly understood. As a consequence, a broad variety of anti-Tn monoclonal antibodies (mAbs) have been generated. To further investigate the nature and complexity of the Tn antigen, we generated seven different anti-Tn mAbs of IgM and IgG classes raised against human Jurkat T cells, which...... are Tn-positive due to the low activity of T-synthase and mutation in specific chaperone Cosmc. The binding analysis of anti-Tn mAbs with the array of synthetic saccharides, glycopeptides and O-glycoproteins revealed unexpected differences in specificities of anti-Tn mAbs. IgM mAbs bound the terminal Gal...

  12. Multinuclear NMR study of the structure of the Fv fragment of anti-dansyl mouse IgG2a antibody

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hideo; Odaka, Asano; Matsunaga, Chigusa; Kato, Koichi; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo (Japan)); Kawaminami, Shunro (Kao Corp., Tochigi (Japan))

    1991-07-02

    A multinuclear NMR study is reported of Fv, which is a minimum antigen-binding unit of immunoglobulin. Fv has been prepared by clostripain digestion of a mouse anti-dansyl IgG2a monoclonal antibody that lacks the entire C{sub H}1 domain. A variety of Fv analogues labeled with {sup 2}H in the aromatic rings and with {sup 13}C and/or {sup 15}N in the peptide bonds have been prepared and used for multinuclear NMR analyses of Fv spectra of Fv sensitively reflect the antigen binding and can be used along with {sup 1}H and {sup 13}C spectral data for the structural analyses of antigen-antibody interactions. Hydrogen-deuterium exchange of the amide protons has been folowed in the absence and presence of DNS-Lys by using the {sup 1}H-{sup 15}N shift correlation spectra. Use of the {beta}-shift observed for the carbonyl carbon resonances has also been helpful in following the hydrogen-deuterium exchange. On the basis of the NMR data obtained, the static and dynamic structure of the Fv fragment in the absence and presence of DNS-Lys has been discussed.

  13. Multinuclear NMR study of the structure of the Fv fragment of anti-dansyl mouse IgG2a antibody

    International Nuclear Information System (INIS)

    Takahashi, Hideo; Odaka, Asano; Matsunaga, Chigusa; Kato, Koichi; Shimada, Ichio; Arata, Yoji; Kawaminami, Shunro

    1991-01-01

    A multinuclear NMR study is reported of Fv, which is a minimum antigen-binding unit of immunoglobulin. Fv has been prepared by clostripain digestion of a mouse anti-dansyl IgG2a monoclonal antibody that lacks the entire C H 1 domain. A variety of Fv analogues labeled with 2 H in the aromatic rings and with 13 C and/or 15 N in the peptide bonds have been prepared and used for multinuclear NMR analyses of Fv spectra of Fv sensitively reflect the antigen binding and can be used along with 1 H and 13 C spectral data for the structural analyses of antigen-antibody interactions. Hydrogen-deuterium exchange of the amide protons has been folowed in the absence and presence of DNS-Lys by using the 1 H- 15 N shift correlation spectra. Use of the β-shift observed for the carbonyl carbon resonances has also been helpful in following the hydrogen-deuterium exchange. On the basis of the NMR data obtained, the static and dynamic structure of the Fv fragment in the absence and presence of DNS-Lys has been discussed

  14. Detection of serum antitrichomonal antibodies in urogenital trichomoniasis by immunofluorescence.

    Directory of Open Access Journals (Sweden)

    Bhatt R

    1992-04-01

    Full Text Available Trichomonas vaginalis is a frequently encountered genital pathogen in both males and females. In females, vaginitis due to this parasite is one of the most common manifestation. The indirect fluorescent technique (IFA test was carried out to detect antitrichomonal antibodies in 370 female patients using whole cell antigen. Seventy one (19.18% gave positive reaction for either of the class IgG, IgM and IgA antibodies. The level of the IgG class antibodies was found to be higher i.e. 58 (81.69% than IgM 11 (15.27% antibodies, which may be suggestive of past infection or a prolonged manifestation by the organisms.

  15. ROLE OF PREEXISTING VIRUS-SPECIFIC IgG IN PRIMARY DISEASE AND IN REINFECTION WITH RESPIRATORY SYNCYTIAL VIRUS

    Directory of Open Access Journals (Sweden)

    V. Z. Krivitskaya

    2012-01-01

    Full Text Available Abstract. The aim of the study is evaluation of links between presence in blood of specific pre-existing IgG to respiratory-syncytial virus (RSV, clinical course of RSV infection and character specific to RSV humoral immune response in patients of different ages. The antibodies were detected by ELISA using whole RS virus or synthetic peptides corresponded to the selected determinants of the envelope RSV proteins. It was shown that RS specific maternal IgG antibodies passively transferred to babies in utero can circulate in the blood up to 10 months of life. The analysis of paired sera of 45 babies in the age of 1–10 months revealed firstly that presence of maternal IgG specific antibodies to the conservative B-cell immunogenic determinants of the F-protein (amino acids 221–232 and/or the G-protein (amino acids 152–164 and 184–198 is coupled with more high morbidity of primary RSV infection (89% versus 56%, p = 0.023, and also with more high frequency of complicated by bronchus obstruction course of the disease (81% versus 20%, р = 0.001 in compare with babies who were serologically negative to the maternal determinants specific antibodies. The correlation analysis has shown that the high presence of maternal determinant-specific IgG in the blood in babies till 10 months of life is associated in the case of primary infection with disbalance of humoral anti-viral immune response: intensive synthesis of serum RSV IgA. This is evidence of complicated course of infection with simultaneous suppression of response to RSV specific IgG. As opposed to the primary RSV infection in patients older than 3 years (n = 121 it was not detected links between anamnestic determinant-specific IgG synthesized by own immune system as the results of previous disease episodes and synthesis of anti-RSV IgG, IgM, IgE and IgA in RSV re-infections. In the contrast to babies in more older patients the feedback connection between level of pre-existing determinant

  16. Engineering an improved IgG4 molecule with reduced disulfide bond heterogeneity and increased Fab domain thermal stability.

    Science.gov (United States)

    Peters, Shirley J; Smales, C Mark; Henry, Alistair J; Stephens, Paul E; West, Shauna; Humphreys, David P

    2012-07-13

    The integrity of antibody structure, stability, and biophysical characterization are becoming increasingly important as antibodies receive increasing scrutiny from regulatory authorities. We altered the disulfide bond arrangement of an IgG4 molecule by mutation of the Cys at the N terminus of the heavy chain constant domain 1 (C(H)1) (Kabat position 127) to a Ser and introduction of a Cys at a variety of positions (positions 227-230) at the C terminus of C(H)1. An inter-LC-C(H)1 disulfide bond is thus formed, which mimics the disulfide bond arrangement found in an IgG1 molecule. The antibody species present in the supernatant following transient expression in Chinese hamster ovary cells were analyzed by immunoblot to investigate product homogeneity, and purified product was analyzed by a thermofluor assay to determine thermal stability. We show that the light chain can form an inter-LC-C(H)1 disulfide bond with a Cys when present at several positions on the upper hinge (positions 227-230) and that such engineered disulfide bonds can consequently increase the Fab domain thermal stability between 3 and 6.8 °C. The IgG4 disulfide mutants displaying the greatest increase in Fab thermal stability were also the most homogeneous in terms of disulfide bond arrangement and antibody species present. Importantly, mutations did not affect the affinity for antigen of the resultant molecules. In combination with the previously described S241P mutation, we present an IgG4 molecule with increased Fab thermal stability and reduced product heterogeneity that potentially offers advantages for the production of IgG4 molecules.

  17. Autoimmune hemolytic anemia, as part of Evans' syndrome, caused by cold reactive IgG autoantibodies

    NARCIS (Netherlands)

    Jaarsma, AS; Muis, N; DeGraaf, SSN

    1996-01-01

    We describe a boy with Evans' syndrome, consisting of immune thrombocytopenic purpura at age 2 and autoimmune hemolytic anemia (AIHA) at age 4. AIHA was caused by cold Ige autoantibodies. This is unusual because AIHA is generally associated with either warm IgG antibodies or cold IgM antibodies.

  18. Stability of monoclonal antibodies at high-concentration

    DEFF Research Database (Denmark)

    Neergaard, Martin S; Nielsen, Anders D; Parshad, Henrik

    2014-01-01

    Few studies have so far directly compared the impact of antibody subclass on protein stability. This case study investigates two mAbs (one IgG1 and one IgG4 ) with identical variable region. Investigations of mAbs that recognize similar epitopes are necessary to identify possible differences betw...

  19. Diagnostic accuracy and comparison of two assays for Borrelia-specific IgG and IgM antibodies

    DEFF Research Database (Denmark)

    Dessau, Ram

    2013-01-01

    characteristic (ROC) curves to optimize and standardize test interpretation, it was shown that testing with both IDEIA IgG and IgM was comparable to testing with Liaison IgG alone by comparing the area under the curve of the diagnostically relevant 25 % partial ROC curve (P = 0.1). When using the Liaison Osp......M combined) were 85 and 95 % and for the Liaison (VlsE IgG) method were 67 and 96 %, respectively. Methods for test evaluation, test interpretation and statistical testing are presented and discussed. In conclusion, Liaison VlsE IgG alone and IDEIA IgG/IgM combined showed a high and comparable discriminatory...

  20. Production and purification of polyclonal antibody against F(ab')2 fragment of human immunoglobulin G

    OpenAIRE

    Nasiri, Hadi; Valedkarimi, Zahra; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Kazemi, Tohid; Esparvarinha, Mojghan; Majidi, Jafar

    2017-01-01

    Antibodies are essential tools of biomedical and biochemical researches. Polyclonal antibodies are produced against different epitopes of antigens. Purified F(ab')2 can be used for animal’s immunization to produce polyclonal antibodies. Human immunoglobulin G (IgG) was purified by ion exchange chromatography method. In all stages verification method of the purified antibodies was sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Purified IgG was digested by pepsin enzyme a...

  1. A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

    DEFF Research Database (Denmark)

    Barington, T; Sparholt, S; Juul, L

    1992-01-01

    A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...... antibodies in one incubation, the second incubation and washing procedure could be omitted from the original technique. The simplified assay had the same sensitivity for anti-TT and anti-DT spot-forming cells as the ordinary ELISPOT assay. The IgG anti-PRP spots were, however, improved both in quality...... and in quantity (median: 40% more spots), while the detection of IgM and IgA anti-PRP spot-forming cells was the same in the two techniques. This simplified technique can probably also be used to save time in other antigen systems and should be considered when designing ELISPOT assays for the detection...

  2. Technical note: Protozoa-specific antibodies raised in sheep plasma bind to their target protozoa in the rumen.

    Science.gov (United States)

    Williams, Y J; Rea, S M; Popovski, S; Skillman, L C; Wright, A-D G

    2014-12-01

    Binding of IgG antibodies to Entodinium spp. in the rumen of sheep (Ovis aries) was investigated by adding IgG, purified from plasma, directly into the rumen. Plasma IgG was sourced from sheep that had or had not been immunized with a vaccine containing whole fixed Entodinium spp. cells. Ruminal fluid was sampled approximately 2 h after each antibody dosing. Binding of protozoa by a specific antibody was detected using an indirect fluorescent antibody test. An antibody titer in the ruminal fluid was determined by ELISA, and the concentration of ruminal fluid ammonia-N and ruminal pH were also determined. Entodinium spp. and total protozoa from IgG-infused sheep were enumerated by microscopic counts. Two-hourly additions of IgG maintained a low antibody titer in the rumen for 12 h and the binding of the antibody to the rumen protozoa was demonstrated. Increased ammonia-N concentrations and altered ruminal fluid pH patterns indicated that additional fermentation of protein was occurring in the rumen after addition of IgG. No reduction in numbers of Entodinium spp. was observed (P>0.05). Although binding of antibodies to protozoa has been demonstrated in the rumen, it is unclear how much cell death occurred. On the balance of probability, it would appear that the antibody was degraded or partially degraded, and the impact of this on protozoal populations and the measurement of a specific titer is also unclear.

  3. ANTIBODI MONOKLONAL STREPTOKOKUS MUTANS 1(c 67 kDa DALAM PASTA GIGI BAHAN DASAR UNTUK MENGHAMBAT PERTUMBUHAN STREPTOKOKUS MUTANS

    Directory of Open Access Journals (Sweden)

    Rini Devijanti R.

    2015-08-01

    Full Text Available Prevention of dental caries is still continuing, because the prevalency caries is high. There was many methods to prevent dental caries etc. dental education, oral hygiene, special method on tooth brushing, water fluoridation, fissure sealant and later on the passive immunization with monoclonal antibodies. The purpose of this study was to investigate about monoclonal antibodies IgA, IgG1 and IgG3 against Streptococcus mutans 1(c in basic paste for inhibiting the growth Streptococcus mutans. The monoclonal antibodies were IgA Ab, IgG1 Ab and IgG3 Ab. Formula basic paste from PT “X” contained Aqua, Sorbitol, Nipagin, Dicalcium Phosphat, Titanium Dioxid, Sodium Carboxyl Methyl Sel. Sodium Lauryl Sulfate and Sacarin. Basic paste was mixed with monoclonal antibodies IgA, IgG1 and IgG3 in room temperature (27oC then to investigate zone of inhibition from these tooth paste with Wistreich and Lechman methods. The data obtained in this study was analyzed with one way Anova and LSD. The result showed that there was a significant differences between basic paste with or without monoclonal antibodies. From the data analyzed in this study it can be concluded that monoclonal antibodies against S. mutans 1( c could be formulation with basic paste.

  4. Development of radiolabelling techniques of anti-CEA monoclonal antibody

    International Nuclear Information System (INIS)

    Castiglia, S.G. de

    1998-01-01

    The purpose of this work was to label monoclonal and polyclonal antibodies with 99 Tc m such as the ior-CEA-1 antibody and polyclonal IgG using a direct method, to check the radiochemical and biological behavior of labelled products, to prepare it under sterile and apyrogenic conditions as a lyophilized kit and to employ it in clinical trials. In addition, a photoactivation method was used to label polyclonal IgG with 99 Tc m and to compare with the established method using mercaptoethanol (2-ME) as the reducing agent. Finally polyclonal IgG was labelled using an indirect method in which a chelator was covalently attached to the protein and the 99 Tc m added as glucoheptonate complex. The properties of 99 Tc m when labelled with monoclonal and polyclonal antibodies by different methods were assessed by in vitro and in vivo studies

  5. IgE and allergen-specific immunotherapy-induced IgG4 recognize similar epitopes of Bet v 1, the major allergen of birch pollen.

    Science.gov (United States)

    Groh, N; von Loetzen, C S; Subbarayal, B; Möbs, C; Vogel, L; Hoffmann, A; Fötisch, K; Koutsouridou, A; Randow, S; Völker, E; Seutter von Loetzen, A; Rösch, P; Vieths, S; Pfützner, W; Bohle, B; Schiller, D

    2017-05-01

    Allergen-specific immunotherapy (AIT) with birch pollen generates Bet v 1-specific immunoglobulin (Ig)G 4 which blocks IgE-mediated hypersensitivity mechanisms. Whether IgG 4 specific for Bet v 1a competes with IgE for identical epitopes or whether novel epitope specificities of IgG 4 antibodies are developed is under debate. We sought to analyze the epitope specificities of IgE and IgG 4 antibodies from sera of patients who received AIT. 15 sera of patients (13/15 received AIT) with Bet v 1a-specific IgE and IgG 4 were analyzed. The structural arrangements of recombinant (r)Bet v 1a and rBet v 1a _11x , modified in five potential epitopes, were analyzed by circular dichroism and nuclear magnetic resonance spectroscopy. IgE binding to Bet v 1 was assessed by ELISA and mediator release assays. Competitive binding of monoclonal antibodies specific for Bet v 1a and serum IgE/IgG 4 to rBet v 1a and serum antibody binding to a non-allergenic Bet v 1-type model protein presenting an individual epitope for IgE was analyzed in ELISA and western blot. rBet v 1a _11x had a Bet v 1a - similar secondary and tertiary structure. Monomeric dispersion of rBet v 1a _11x was concentration and buffer-dependent. Up to 1500-fold increase in the EC 50 for IgE-mediated mediator release induced by rBet v 1a _11x was determined. The reduction of IgE and IgG 4 binding to rBet v 1a _11x was comparable in 67% (10/15) of sera. Bet v 1a-specific monoclonal antibodies inhibited binding of serum IgE and IgG 4 to 66.1% and 64.9%, respectively. Serum IgE and IgG 4 bound specifically to an individual epitope presented by our model protein in 33% (5/15) of sera. Patients receiving AIT develop Bet v 1a-specific IgG 4 which competes with IgE for partly identical or largely overlapping epitopes. The similarities of epitopes for IgE and IgG 4 might stimulate the development of epitope-specific diagnostics and therapeutics. © 2016 John Wiley & Sons Ltd.

  6. Possible role of specific immunoglobulin M antibodies to Plasmodium falciparum antigens in immunoprotection of humans living in a hyperendemic area, Burkina Faso

    DEFF Research Database (Denmark)

    Boudin, C; Chumpitazi, B; Dziegiel, M

    1993-01-01

    of antibodies to crude extracts of Plasmodium falciparum (IgG or IgM antisomatic and IgG antiexoantigens) were tested by IFI or enzyme-linked immunosorbent assay and were followed up according to the fluctuations of the parasite densities. Specific IgG antibodies had the same evolution as parasite densities....... Group 3 was composed of immunoprotected adults. Specific IgM and IgG antibodies to crude extracts or a recombinant antigen (glutamate-rich protein) of P. falciparum were tested. Specific IgM antibodies were lower in group 1 (nonimmune) than in groups 2 (semiimmune) and 3 (immunoprotected). Furthermore...

  7. Passive immunization against Cryptococcus neoformans with an isotype-switch family of monoclonal antibodies reactive with cryptococcal polysaccharide.

    Science.gov (United States)

    Sanford, J E; Lupan, D M; Schlageter, A M; Kozel, T R

    1990-01-01

    The in vivo properties of an immunoglobulin isotype-switch family of monoclonal antibodies specific for the polysaccharide capsule of Cryptococcus neoformans were examined in a murine model of cryptococcosis. Subclass-switch variants were isolated by sequential sublining of an immunoglobulin G subclass 1 (IgG1)-secreting cell line. Antibodies of the IgG1, IgG2a, and IgG2b isotypes with identical reactivities with cryptococcal polysaccharide were prepared. The antibodies had the distinct biological properties associated with the heavy chains of each respective isotype. The antibodies were used prophylactically or therapeutically in an attempt to alter the course of cryptococcal infection in mice. Survival of mice and a tissue census of the numbers of viable cryptococci in the lung, spleen, and brain were used as indicators of efficacy. Passive immunization with the IgG2a and IgG2b antibodies effected a reduction in the numbers of cryptococci in lung and spleen. Passive immunization with the IgG1 antibody was markedly less effective. Passive immunization had little or no effect on the numbers of cryptococci in brain tissue, regardless of the immunoglobulin isotype. Despite apparent efficacy with regard to reduction in the numbers of yeast cells in the lung and spleen, the results showed no improvement in survival from murine cryptococcosis. Our results indicate that passive immunization produces a modest effect on the course of murine cryptococcosis in tissues other than brain. However, under the experimental conditions used, such treatment does not have a measurable impact on the ultimate outcome of the infection. PMID:2341184

  8. IgG4-related Hypophysitis with Subtle Hypopituitarism in an Elderly Diabetic Patient: Is Treatment or Observation Preferable?

    Science.gov (United States)

    Kawasaki, Motoki; Tsujino, Motoyoshi; Sato, Fuminori; Sakurada, Maya; Nishida, Kenji; Kise, Takayasu; Hijioka, Yuko; Ishizawa, Mitsugu; Enatsu, Kazuaki; Ogawa, Yoshihiro

    2017-10-15

    A 70-year-old man with diabetes mellitus presented with an enlarged pituitary stalk in 2014. IgG4-related parotitis and submandibular sialoadenitis were diagnosed in 2012. He denied any symptoms related to a pituitary mass. His visual field was intact, and his hypopituitarism was subtle. The serum IgG4 level was elevated. A lip biopsy revealed strong fibrosis and hyper-infiltration of IgG4-positive plasma cells. Based on these findings, IgG4-related hypophysitis was diagnosed. The patient was carefully followed without specific intervention. His clinical condition showed no change until December 2016, suggesting a stable, natural course. Care should be taken when considering glucocorticoid therapy, especially for elderly diabetic patients, given possible side effects.

  9. Site-specific photoconjugation of antibodies using chemically synthesized IgG-binding domains.

    Science.gov (United States)

    Perols, Anna; Karlström, Amelie Eriksson

    2014-03-19

    Site-specific labeling of antibodies can be performed using the immunoglobulin-binding Z domain, derived from staphylococcal protein A (SpA), which has a well-characterized binding site in the Fc region of antibodies. By introducing a photoactivable probe in the Z domain, a covalent bond can be formed between the Z domain and the antibody by irradiation with UV light. The aim of this study was to improve the conjugation yield for labeling of different subclasses of IgG having different sequence composition, using a photoactivated Z domain variant. Four different variants of the Z domain (Z5BPA, Z5BBA, Z32BPA, and Z32BBA) were synthesized to investigate the influence of the position of the photoactivable probe and the presence of a flexible linker between the probe and the protein. For two of the variants, the photoreactive benzophenone group was introduced as part of an amino acid side chain by incorporation of the unnatural amino acid benzoylphenylalanine (BPA) during peptide synthesis. For the other two variants, the photoreactive benzophenone group was attached via a flexible linker by coupling of benzoylbenzoic acid (BBA) to the ε-amino group of a selectively deprotected lysine residue. Photoconjugation experiments using human IgG1, mouse IgG1, and mouse IgG2A demonstrated efficient conjugation for all antibodies. It was shown that differences in linker length had a large impact on the conjugation efficiency for labeling of mouse IgG1, whereas the positioning of the photoactivable probe in the sequence of the protein had a larger effect for mouse IgG2A. Conjugation to human IgG1 was only to a minor extent affected by position or linker length. For each subclass of antibody, the best variant tested using a standard conjugation protocol resulted in conjugation efficiencies of 41-66%, which corresponds to on average approximately one Z domain attached to each antibody. As a combination of the two best performing variants, Z5BBA and Z32BPA, a Z domain variant with

  10. Application of hanging drop technique to optimize human IgG formulations.

    Science.gov (United States)

    Li, Guohua; Kasha, Purna C; Late, Sameer; Banga, Ajay K

    2010-01-01

    The purpose of this work is to assess the hanging drop technique in screening excipients to develop optimal formulations for human immunoglobulin G (IgG). A microdrop of human IgG and test solution hanging from a cover slide and undergoing vapour diffusion was monitored by a stereomicroscope. Aqueous solutions of IgG in the presence of different pH, salt concentrations and excipients were prepared and characterized. Low concentration of either sodium/potassium phosphate or McIlvaine buffer favoured the solubility of IgG. Addition of sucrose favoured the stability of this antibody while addition of NaCl caused more aggregation. Antimicrobial preservatives were also screened and a complex effect at different buffer conditions was observed. Dynamic light scattering, differential scanning calorimetry and size exclusion chromatography studies were performed to further validate the results. In conclusion, hanging drop is a very easy and effective approach to screen protein formulations in the early stage of formulation development.

  11. Malaria resistance genes are associated with the levels of IgG subclasses directed against Plasmodium falciparum blood-stage antigens in Burkina Faso

    Directory of Open Access Journals (Sweden)

    Afridi Sarwat

    2012-09-01

    Full Text Available Abstract Background HBB, IL4, IL12, TNF, LTA, NCR3 and FCGR2A polymorphisms have been associated with malaria resistance in humans, whereas cytophilic immunoglobulin G (IgG antibodies are thought to play a critical role in immune protection against asexual blood stages of the parasite. Furthermore, HBB, IL4, TNF, and FCGR2A have been associated with both malaria resistance and IgG levels. This suggests that some malaria resistance genes influence the levels of IgG subclass antibodies. Methods In this study, the effect of HBB, IL4, IL12, TNF, LTA, NCR3 and FCGR2A polymorphisms on the levels of IgG responses against Plasmodium falciparum blood-stage extract was investigated in 220 individuals living in Burkina Faso. The Pearson’s correlation coefficient among IgG subclasses was determined. A family-based approach was used to assess the association of polymorphisms with anti-P. falciparum IgG, IgG1, IgG2, IgG3 and IgG4 levels. Results After applying a multiple test correction, several polymorphisms were associated with IgG subclass or IgG levels. There was an association of i haemoglobin C with IgG levels; ii the FcγRIIa H/R131 with IgG2 and IgG3 levels; iii TNF-863 with IgG3 levels; iv TNF-857 with IgG levels; and, v TNF1304 with IgG3, IgG4, and IgG levels. Conclusion Taken together, the results support the hypothesis that some polymorphisms affect malaria resistance through their effect on the acquired immune response, and pave the way towards further comprehension of genetic control of an individual’s humoral response against malaria.

  12. Membranous glomerulonephritis in a patient with anti-u1 ribonucleoprotein (RNP antibody-positive mixed connective tissue disease: A case report

    Directory of Open Access Journals (Sweden)

    Naoya Toriu

    2018-03-01

    Full Text Available We report a 33-year-old Japanese man diagnosed with mixed connective tissue disease (MCTD who developed nephrotic proteinuria. Both speckled antinuclear antibody (ANA and anti-U1 ribonucleoprotein (RNP antibody were positive, but anti-double-stranded DNA (dsDNA antibody and anti-Smith (Sm antibody were negative, while complement levels were normal. Renal biopsy revealed membranous glomerulonephritis (MGN with diffuse thickening of the glomerular basement membrane (GBM plus spike and bubble formation. Immunofluorescence demonstrated granular deposits of IgG and C3 along the GBM. Analysis of IgG subclasses showed predominant deposition of IgG1 and IgG4, unlike typical lupus nephritis in which there is predominant deposition of IgG1, IgG2, IgG3, and C1q. Electron microscopy identified numerous large electron-dense deposits (EDD of various types in the subepithelial region of the GBM, but there were no EDD localized in the mesangium or subendothelium. Based on these findings, MGN was considered to be closely related to MCTD in this patient.

  13. Gambaran Igg4 dan Ige terhadap Protein Mikrofilaria pada Sera Penduduk Endemis Filariasis di Kecamatan Pasir Penyu, Riau

    OpenAIRE

    SU, Basundari; Kurniawan, Liliana; A., Soeroto; Marleta, Rita; Yasin, M

    1993-01-01

    Western blot test to detect specific IgG4 and IgE was performed to 12 microfilaraemic and 13 amicrofilaraemic individuals from malayan filariasis endemic area, Pasir Penyu, Riau. No differences in binding patterns of IgG4 and IgE antibodies to microfUarial protein components was shown. There was a parallel protein components recognition by IgG4 and IgE of molecular weight ranging from 158 kd to 14 kd. Protein component of 125 kd was only recognized by IgG4 and of 112 kd only by IgE. These fin...

  14. Neutralisation of venom-induced haemorrhage by IgG from camels and llamas immunised with viper venom and also by endogenous, non-IgG components in camelid sera

    NARCIS (Netherlands)

    Harrison, R.A.; Hasson, S.S.; Harmsen, M.M.; Laing, G.D.; Theakston, R.D.

    2006-01-01

    Envenoming by snakes results in severe systemic and local pathology. Intravenous administration of antivenom, prepared from IgG of venom immunised horses or sheep, is the only effective treatment of systemic envenoming. Conventional antivenoms, formulated as intact IgG, papain-cleaved (Fab) or

  15. Relative Contribution of Dengue IgG Antibodies Acquired during Gestation or Breastfeeding in Mediating Dengue Disease Enhancement and Protection in Type I Interferon Receptor-Deficient Mice.

    Directory of Open Access Journals (Sweden)

    Pei Xuan Lee

    2016-06-01

    Full Text Available Dengue virus (DENV causes a spectrum of diseases ranging from self-limiting dengue fever to severe conditions such as haemorrhagic fever and dengue shock syndrome. Antibody-dependent enhancement (ADE is thought to explain the occurrence of severe dengue whereby pre-existing binding but non-neutralising antibodies enhance DENV infection. The ADE phenomenon is supported by epidemiological findings that infants that born to dengue immune mothers are at greater risk to develop severe dengue upon primary infection. The role of maternally acquired dengue-specific antibodies in disease enhancement was recently recapitulated in a mouse model where mice born to DENV1-immune mothers experienced enhanced disease severity upon DENV2 infection. Here, this study investigates the relative contribution of maternal dengue-specific antibodies acquired during gestation and breastfeeding in dengue disease. Using a surrogate breastfeeding mother experimental approach, we showed that majority of the maternal dengue-specific antibodies were acquired during breastfeeding and conferred an extended enhancement window. On the other hand, in the context of homologous infection, breastfeeding conferred protection. Furthermore, measurement of dengue-specific antibody titres over time in mice born to dengue immune mothers revealed a biphasic pattern of antibody decay as reported in humans. Our work provides evidence of the potential contribution of breast milk-acquired dengue-specific IgG antibodies in enhancement and protection against dengue. Should such contribution be established in humans as well, it may have important implications for the development of guidelines to dengue-immune breastfeeding mothers.

  16. Relative Contribution of Dengue IgG Antibodies Acquired during Gestation or Breastfeeding in Mediating Dengue Disease Enhancement and Protection in Type I Interferon Receptor-Deficient Mice.

    Science.gov (United States)

    Lee, Pei Xuan; Ong, Li Ching; Libau, Eshele Anak; Alonso, Sylvie

    2016-06-01

    Dengue virus (DENV) causes a spectrum of diseases ranging from self-limiting dengue fever to severe conditions such as haemorrhagic fever and dengue shock syndrome. Antibody-dependent enhancement (ADE) is thought to explain the occurrence of severe dengue whereby pre-existing binding but non-neutralising antibodies enhance DENV infection. The ADE phenomenon is supported by epidemiological findings that infants that born to dengue immune mothers are at greater risk to develop severe dengue upon primary infection. The role of maternally acquired dengue-specific antibodies in disease enhancement was recently recapitulated in a mouse model where mice born to DENV1-immune mothers experienced enhanced disease severity upon DENV2 infection. Here, this study investigates the relative contribution of maternal dengue-specific antibodies acquired during gestation and breastfeeding in dengue disease. Using a surrogate breastfeeding mother experimental approach, we showed that majority of the maternal dengue-specific antibodies were acquired during breastfeeding and conferred an extended enhancement window. On the other hand, in the context of homologous infection, breastfeeding conferred protection. Furthermore, measurement of dengue-specific antibody titres over time in mice born to dengue immune mothers revealed a biphasic pattern of antibody decay as reported in humans. Our work provides evidence of the potential contribution of breast milk-acquired dengue-specific IgG antibodies in enhancement and protection against dengue. Should such contribution be established in humans as well, it may have important implications for the development of guidelines to dengue-immune breastfeeding mothers.

  17. Relative Contribution of Dengue IgG Antibodies Acquired during Gestation or Breastfeeding in Mediating Dengue Disease Enhancement and Protection in Type I Interferon Receptor-Deficient Mice

    Science.gov (United States)

    Lee, Pei Xuan; Ong, Li Ching; Libau, Eshele Anak; Alonso, Sylvie

    2016-01-01

    Dengue virus (DENV) causes a spectrum of diseases ranging from self-limiting dengue fever to severe conditions such as haemorrhagic fever and dengue shock syndrome. Antibody-dependent enhancement (ADE) is thought to explain the occurrence of severe dengue whereby pre-existing binding but non-neutralising antibodies enhance DENV infection. The ADE phenomenon is supported by epidemiological findings that infants that born to dengue immune mothers are at greater risk to develop severe dengue upon primary infection. The role of maternally acquired dengue-specific antibodies in disease enhancement was recently recapitulated in a mouse model where mice born to DENV1-immune mothers experienced enhanced disease severity upon DENV2 infection. Here, this study investigates the relative contribution of maternal dengue-specific antibodies acquired during gestation and breastfeeding in dengue disease. Using a surrogate breastfeeding mother experimental approach, we showed that majority of the maternal dengue-specific antibodies were acquired during breastfeeding and conferred an extended enhancement window. On the other hand, in the context of homologous infection, breastfeeding conferred protection. Furthermore, measurement of dengue-specific antibody titres over time in mice born to dengue immune mothers revealed a biphasic pattern of antibody decay as reported in humans. Our work provides evidence of the potential contribution of breast milk-acquired dengue-specific IgG antibodies in enhancement and protection against dengue. Should such contribution be established in humans as well, it may have important implications for the development of guidelines to dengue-immune breastfeeding mothers. PMID:27341339

  18. [IgG4-related disease - a case report].

    Science.gov (United States)

    Milczarek-Banach, Justyna; Brodzińska, Kinga; Jankowska, Anna; Ambroziak, Urszula; Szczepankiewicz, Benedykt; Nałęcz-Janik, Jolanta; Miśkiewicz, Piotr

    2017-09-29

    Immunoglobulin G4-related disease (IgG4-RD) is a comparatively new condition that may involve more than one organ. The lack of characteristic, pathognomonic clinical symptoms may delay the diagnosis of this disease. The diagnosis is based upon clinical manifestation, elevated serum levels of IgG4 and histopathologic examination with immunohistochemical staining to reveal infiltration of IgG4-positive plasma cells. The first line treatment is oral glucocorticoids. 38-year-old woman with Hashimoto disease, chronic sinusitis and chronic hepatitis of unknown etiology was admitted to the Department of Endocrinology because of moderate eyelids swelling accompanied by redness for 3 years. Graves' orbitopathy and systemic vasculitis were suspected, however both were excluded (negative antibodies results: anty-TSHR, ANCA, ANA). Serologic investigation of Sjögren's syndrome was also negative. In Magnetic Resonance Imaging (MRI) of orbits there were described bilateral mild extension of lateral rectus muscles, normal signal of adipose tissue and bilateral lacrimal glands enlargement. Moreover, increased IgG4 serum levels were detected. The material derived from perinasal sinuses surgery was analyzed in histopathology examination with immunohistochemical staining, which revealed characteristic features of chronic inflammatory process and increased numbers of IgG4 - positive plasma cells (>50 in a large field of view). The diagnosis of IgG4-RD was established. Because of non-effective oral methylprednisolone therapy in the past, the patient was referred to Clinic of Rheumatology for further treatment. After the therapy with methylprednisolone and azathioprine there were observed the significant reduction of symptoms. Because of lack of characteristic symptoms of IgG4- RD, it should be always considered in differential diagnosis of chronic inflammatory diseases of various organs.

  19. Genetic engineering of cell lines using lentiviral vectors to achieve antibody secretion following encapsulated implantation.

    Science.gov (United States)

    Lathuilière, Aurélien; Bohrmann, Bernd; Kopetzki, Erhard; Schweitzer, Christoph; Jacobsen, Helmut; Moniatte, Marc; Aebischer, Patrick; Schneider, Bernard L

    2014-01-01

    The controlled delivery of antibodies by immunoisolated bioimplants containing genetically engineered cells is an attractive and safe approach for chronic treatments. To reach therapeutic antibody levels there is a need to generate renewable cell lines, which can long-term survive in macroencapsulation devices while maintaining high antibody specific productivity. Here we have developed a dual lentiviral vector strategy for the genetic engineering of cell lines compatible with macroencapsulation, using separate vectors encoding IgG light and heavy chains. We show that IgG expression level can be maximized as a function of vector dose and transgene ratio. This approach allows for the generation of stable populations of IgG-expressing C2C12 mouse myoblasts, and for the subsequent isolation of clones stably secreting high IgG levels. Moreover, we demonstrate that cell transduction using this lentiviral system leads to the production of a functional glycosylated antibody by myogenic cells. Subsequent implantation of antibody-secreting cells in a high-capacity macroencapsulation device enables continuous delivery of recombinant antibodies in the mouse subcutaneous tissue, leading to substantial levels of therapeutic IgG detectable in the plasma.

  20. Pathogenicity of IgG in patients with IgG4-related disease.

    Science.gov (United States)

    Shiokawa, Masahiro; Kodama, Yuzo; Kuriyama, Katsutoshi; Yoshimura, Kenichi; Tomono, Teruko; Morita, Toshihiro; Kakiuchi, Nobuyuki; Matsumori, Tomoaki; Mima, Atsushi; Nishikawa, Yoshihiro; Ueda, Tatsuki; Tsuda, Motoyuki; Yamauchi, Yuki; Minami, Ryuki; Sakuma, Yojiro; Ota, Yuji; Maruno, Takahisa; Kurita, Akira; Sawai, Yugo; Tsuji, Yoshihisa; Uza, Norimitsu; Matsumura, Kazuyoshi; Watanabe, Tomohiro; Notohara, Kenji; Tsuruyama, Tatsuaki; Seno, Hiroshi; Chiba, Tsutomu

    2016-08-01

    IgG4-related disease (IgG4-RD) is a systemic disease characterised by elevated serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in the affected tissues. The pathogenic role of IgGs, including IgG4, in patients with IgG4-RD, however, is unknown. We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal male Balb/c mice. Binding of patient IgGs to pancreatic tissue was also analysed in an ex vivo mouse organ culture model and in tissue samples from patients with autoimmune pancreatitis (AIP). Subcutaneous injection of patient IgG, but not control IgG, resulted in pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patient IgG1 or IgG4, with more destructive changes induced by IgG1 than by IgG4. The potent pathogenic activity of patient IgG1 was significantly inhibited by simultaneous injection of patient IgG4. Binding of patient IgG, especially IgG1 and IgG4, to pancreatic tissue was confirmed in both the mouse model and AIP tissue samples. IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding affected tissues in neonatal mice. 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/

  1. Radioimmunoimaging using F(ab')2 fragment of monoclonal antibodies against human alpha-fetoprotein

    International Nuclear Information System (INIS)

    Sakahara, Harumi; Endo, Keigo; Nakashima, Tetsuo; Koizumi, Mitsuru; Ohta, Hitoya; Torizuka, Kanji; Okada, Kenichiro; Yoshida, Osamu; Nishi, Shinzo.

    1985-01-01

    Using monoclonal antibodies against human α-fetoprotein (AFP), radioiodinated F(ab') 2 fragments were compared with whole IgG as a radiotracer for radioimmunoimaging of cancer. F(ab') 2 fragments were obtained by pepsin digestion of whole IgG (IgGl). IgG and F(ab') 2 were labeled with 125 I or 131 I by the chloramine-T method with almost full retention of antibody activity. F(ab') 2 fragments were cleared more rapidly from the circulation in normal mice with a half life of 6.3 hours than whole IgG with a half life of 5.5 days. Radioactivity of F(ab') 2 in various organs also decreased faster than IgG. In nude mice transplanted with AFP-producing human testicular tumor, F(ab') 2 fragments demonstrated superior scintigrams to whole IgG at 2 days after the injection, because of the fast disappearance of background radioactivity. Although absolute accumulation of 131 I labeled F(ab') 2 in the tumor was less than that of 131 I labeled IgG, tumor to other organ ratios were much higher with F(ab') 2 than those of IgG. The tumor to blood ratio of 131 I labeled F(ab') 2 was 1.04 at day 2, whereas tumor to blood ratio of 131 I labeled IgG was 0.55 at day 2 and 0.92 at day 4, respectively. These results indicated that for the radiolabeling of monoclonal antibodies, F(ab') 2 fragments would be superior to whole IgG in the radioimmunoimaging of cancer. (author)

  2. Highly sensitive electrochemical immunoassay for human IgG using double-encoded magnetic redox-active nanoparticles

    International Nuclear Information System (INIS)

    Tang, D.; Tang, J.; Su, B.; Chen, H.; Chen, G.; Huang, J.

    2010-01-01

    A new sandwich-type electrochemical immunoassay was developed for the detection of human IgG using doubly-encoded and magnetic redox-active nanoparticles as recognition elements on the surface of a glassy carbon electrode modified with anti-IgG on nanogold particles. The recognition elements were synthesized by coating magnetic Fe3O4 nanoparticles with Prussian blue nanoparticles and then covered with peroxidase-labeled anti-IgG antibodies (POx-anti-IgG) on Prussian blue nanoparticles. The immunoelectrode displays very good electrochemical properties towards detection of IgG via using double-encoded magnetic redox-active nanoparticles as trace and hydrogen peroxide as enzyme substrate. Its limit of detection (10 pmol.L -1 ) is 10-fold better than that of using plain POx-anti-IgG secondary antibodies. The method was applied to the detection of IgG in serum samples, and an excellent correspondence with the reference values was found. (author)

  3. [Determination of cytomegalovirus IgG synthesis by the albumin correction in the aqueous humor of posner-schlossmann syndrome].

    Science.gov (United States)

    Wang, X L; Wang, Z J; Tang, L; Cao, W W; Sun, X H

    2017-02-11

    Objective: To evaluate the usefulness of albumin correction in determination of cytomegalovirus IgG in the aqueous humor of Posner-Schlossman syndrome (PSS) patients. Methods: Cases series studies. Forty-two patients (26 men and 16 women) who were diagnosed as PSS were enrolled from Oct. 2009 to Oct. 2015 at the Eye and ENT Hospital. During the same period, 20 patients with primary open-angle glaucoma (POAG) and 30 patients with bacterial endophthalmitis or retinal necrosis were enrolled as negative control group and inflammatory disease control group, respectively. Aqueous humor and serum samples were assayed to detect CMV IgG by enzyme-linked immunosorbent assay (ELISA), and albumin by scattering immunonephelometry. CMV DNA in aqueous humor was assayed by polymerase chain reaction (PCR). The ratio which was calculated as the (aqueous humor CMV IgG/serum CMV IgG)/(aqueous humor concentration of albumin/serum albumin concentration) over 0.6 was considered as intraocular antibody formation. Performance of differentiating control eyes from eyes with CMV-positive PSS was evaluated by the receiver operating characteristic curve. The ANOVA test, Mann-Whitney test and Chi-square test were performed to compare the differences among groups. Results: The detectable rate of CMV IgG antibody in the aqueous humor was 76.2%, 100.0% and 10.0% in PSS, inflammatory disease control and POAG groups, respectively. The levels of CMV IgG antibody in the PSS groups were significantly higher than that of POAG groups ( Z= 4.23, Palbumin was 71.4%, 3.3% and 0.0%.The corrected positive rate in PSS groups was significantly higher than that of the inflammatory disease control and POAG groups (χ(2)=30.38, Palbumin could effectively improve aqueous antibody specificity in PSS patients. Furthermore, CMV IgG antibody ratio combined with PCR could improve the sensitivity of CMV detection. All of which help clarify the CMV infection in PSS in CMV DNA negative eyes. (Chin J Ophthalmol, 2017, 53

  4. Immunoglobulin G1 Allotype Influences Antibody Subclass Distribution in Response to HIV gp140 Vaccination

    Directory of Open Access Journals (Sweden)

    Sven Kratochvil

    2017-12-01

    Full Text Available Antibody subclasses exhibit extensive polymorphisms (allotypes that could potentially impact the quality of HIV-vaccine induced B cell responses. Allotypes of immunoglobulin (Ig G1, the most abundant serum antibody, have been shown to display altered functional properties in regard to serum half-life, Fc-receptor binding and FcRn-mediated mucosal transcytosis. To investigate the potential link between allotypic IgG1-variants and vaccine-generated humoral responses in a cohort of 14 HIV vaccine recipients, we developed a novel protocol for rapid IgG1-allotyping. We combined PCR and ELISA assays in a dual approach to determine the IgG1 allotype identity (G1m3 and/or G1m1 of trial participants, using human plasma and RNA isolated from PBMC. The IgG1-allotype distribution of our participants mirrored previously reported results for caucasoid populations. We observed elevated levels of HIV gp140-specific IgG1 and decreased IgG2 levels associated with the G1m1-allele, in contrast to G1m3 carriers. These data suggest that vaccinees homozygous for G1m1 are predisposed to develop elevated Ag-specific IgG1:IgG2 ratios compared to G1m3-carriers. This elevated IgG1:IgG2 ratio was further associated with higher FcγR-dimer engagement, a surrogate for potential antibody-dependent cellular cytotoxicity (ADCC and antibody-dependent cellular phagocytosis (ADCP function. Although preliminary, these results suggest that IgG1 allotype may have a significant impact on IgG subclass distribution in response to vaccination and associated Fc-mediated effector functions. These results have important implications for ongoing HIV vaccine efficacy studies predicated on engagement of FcγR-mediated cellular functions including ADCC and ADCP, and warrant further investigation. Our novel allotyping protocol provides new tools to determine the potential impact of IgG1 allotypes on vaccine efficacy.

  5. Proteolytic activity of IgGs from blood serum of wistar rats at experimental rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Yu. Ya. Kit

    2014-10-01

    Full Text Available The aim of this work was to study the proteolytic activity of IgGs purified from blood serum of Wistar rats at experimental rheumatoid arthritis (ERA induced by an injection of bovine collagen of type II. Twenty rats were immunized with a preparation of bovine collagen II (Sigma-Aldrich, USA in the presence of complete Freund’s adjuvant. ERA development was determined by inflammation in limbs of treated animals. IgG preparations were isolated from blood serum of immunized and non-immunized animals by precipitation of antibodies with 33% ammonium sulfate followed by chromatography on the Protein G-Sepharose column. Human histone H1, bovine collagen II, calf thymus histones, myelin basic protein (MBP, bovine serum albumin (BSA, and bovine casein were used as substrates of the proteolytic activity of IgGs. It was found that IgG preparations from blood serum of rats with ERA were capable of cleaving histone H1 and MBP, however, they were catalytically inactive towards collagen II, casein, BSA, and core histones. IgGs from blood serum of non-immunized rats were proteolytically inactive towards all used protein substrates. Thus, we demonstrated that immunization of rats with bovine collagen II induced IgG-antibodies possessing the proteolytic activity towards histone H1 and MBP. This activity might be associated with the development of inflammatory processes in the immunized rats.

  6. Technetium-99m labeling anti-amastigote polyclonal antibodies of Leishmania amazonensis

    International Nuclear Information System (INIS)

    Araujo, J.G.V.C.; Toledo, V.P.C.P.; Guimaraes, T.M.P.D.; Bernardo-Filho, M.; Simal, C.J.R.; Mota, L.G.; Diniz, S.O.F.; Cardoso, V.N.

    2002-01-01

    Anti-amastigote polyclonal antibody (IgG) was incubated with solutions of stannous chloride and sodium borohidride. After that, 3.7 MBq of technetium-99m ( 99m Tc) was added. A labeling yield of the antibody about 84% was obtained. After filtration of 99m Tc-IgG, the radiochemical purity increased from 84 to 95%. The labeling of IgG with 99m Tc did not modify the immunoreactivity of the antibody, since it was able to identify in vitro and in vivo the specific antigen of Leishmania amazonensis

  7. Application of monoclonal antibodies in functional and comparative investigations of heavy-chain immunoglobulins in new world camelids.

    Science.gov (United States)

    Daley, L P; Gagliardo, L F; Duffy, M S; Smith, M C; Appleton, J A

    2005-03-01

    Of the three immunoglobulin G (IgG) isotypes described to occur in camelids, IgG2 and IgG3 are distinct in that they do not incorporate light chains. These heavy-chain antibodies (HCAbs) constitute approximately 50% of the IgG in llama serum and as much as 75% of the IgG in camel serum. We have produced isotype-specific mouse monoclonal antibodies (MAbs) in order to investigate the roles of HCAbs in camelid immunity. Seventeen stable hybridomas were cloned, and three MAbs that were specific for epitopes on the gamma chains of llama IgG1, IgG2, or IgG3 were characterized in detail. Affinity chromatography revealed that each MAb bound its isotype in solution in llama serum. The antibodies bound to the corresponding alpaca IgGs, to guanaco IgG1 and IgG2, and to camel IgG1. Interestingly, anti-IgG2 MAbs bound three heavy-chain species in llama serum, confirming the presence of three IgG2 subisotypes. Two IgG2 subisotypes were detected in alpaca and guanaco sera. The MAbs detected llama serum IgGs when they were bound to antigen in enzyme-linked immunosorbent assays and were used to discern among isotypes induced during infection with a parasitic nematode. Diseased animals, infected with Parelaphostrongylus tenuis, did not produce antigen-specific HCAbs; rather, they produced the conventional isotype, IgG1, exclusively. Our data document the utility of these MAbs in functional and physiologic investigations of the immune systems of New World camelids.

  8. Violation of an evolutionarily conserved immunoglobulin diversity gene sequence preference promotes production of dsDNA-specific IgG antibodies.

    Directory of Open Access Journals (Sweden)

    Aaron Silva-Sanchez

    Full Text Available Variability in the developing antibody repertoire is focused on the third complementarity determining region of the H chain (CDR-H3, which lies at the center of the antigen binding site where it often plays a decisive role in antigen binding. The power of VDJ recombination and N nucleotide addition has led to the common conception that the sequence of CDR-H3 is unrestricted in its variability and random in its composition. Under this view, the immune response is solely controlled by somatic positive and negative clonal selection mechanisms that act on individual B cells to promote production of protective antibodies and prevent the production of self-reactive antibodies. This concept of a repertoire of random antigen binding sites is inconsistent with the observation that diversity (DH gene segment sequence content by reading frame (RF is evolutionarily conserved, creating biases in the prevalence and distribution of individual amino acids in CDR-H3. For example, arginine, which is often found in the CDR-H3 of dsDNA binding autoantibodies, is under-represented in the commonly used DH RFs rearranged by deletion, but is a frequent component of rarely used inverted RF1 (iRF1, which is rearranged by inversion. To determine the effect of altering this germline bias in DH gene segment sequence on autoantibody production, we generated mice that by genetic manipulation are forced to utilize an iRF1 sequence encoding two arginines. Over a one year period we collected serial serum samples from these unimmunized, specific pathogen-free mice and found that more than one-fifth of them contained elevated levels of dsDNA-binding IgG, but not IgM; whereas mice with a wild type DH sequence did not. Thus, germline bias against the use of arginine enriched DH sequence helps to reduce the likelihood of producing self-reactive antibodies.

  9. Bronchial asthma is not associated with auto-antibodies to lipocortin-1.

    Science.gov (United States)

    Wilkinson, J R; Podgorski, M R; Godolphin, J L; Goulding, N J; Lee, T H

    1990-03-01

    Corticosteroids may mediate some of their anti-inflammatory action by the induction of lipocortin-1, which inhibits phospholipase A2 activity. Raised levels of antibodies to lipocortin have been found in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) and it has been postulated that these may contribute to steroid resistance. A proportion of asthmatic patients fail to respond to treatment with corticosteroids and one possible mechanism is that these patients have raised levels of anti-lipocortin antibodies. We have therefore measured IgG and IgM antibodies to lipocortin by enzyme linked immunosorbent assay (ELISA) in eight corticosteroid-sensitive (CS) and 7 corticosteroid-resistant (CR) asthmatic subjects, and in eight normal controls. Comparison of asthmatic subjects with normal controls revealed no significant differences in either IgG or IgM antibodies to lipocortin. Comparison of CS asthmatic subjects with CR asthmatic subjects similarly revealed no significant differences in the concentration of either IgG or IgM antibodies to lipocortin. Levels of anti-lipocortin antibodies did not correlate with clinical response to treatment with 40 mg/day of prednisolone. Anti-lipocortin antibodies are unlikely to be involved in the inflammation seen in asthma, or in the relative insensitivity to corticosteroids seen in CR asthmatic subjects.

  10. Antiphospholipid antibodies in Brazilian hepatitis C virus carriers

    Directory of Open Access Journals (Sweden)

    A.M. Atta

    2008-06-01

    Full Text Available Hepatitis C, a worldwide viral infection, is an important health problem in Brazil. The virus causes chronic infection, provoking B lymphocyte dysfunction, as represented by cryoglobulinemia, non-organ-specific autoantibody production, and non-Hodgkin's lymphoma. The aim of this research was to screen for the presence of antiphospholipid autoantibodies in 109 Brazilian hepatitis C virus carriers without clinical history of antiphospholipid syndrome. Forty healthy individuals were used as the control group. IgA, IgG, and IgM antibodies against cardiolipin and β2-glycoprotein I were measured with an enzyme-linked immunosorbent assay, using a cut-off point of either 20 UPL or 20 SBU. While 24 (22.0% hepatitis C carriers had moderate titers of IgM anticardiolipin antibodies (median, 22.5 MPL; 95%CI: 21.5-25.4 MPL, only three carriers (<3% had IgG anticardiolipin antibodies (median, 23 GPL; 95%CI: 20.5-25.5 GPL. Furthermore, IgA anticardiolipin antibodies were not detected in these individuals. Male gender and IgM anticardiolipin seropositivity were associated in the hepatitis C group (P = 0.0004. IgA anti-β2-glycoprotein-I antibodies were detected in 29 of 109 (27.0% hepatitis C carriers (median, 41 SAU; 95%CI: 52.7-103.9 SAU. Twenty patients (18.0% had IgM anti-β2-glycoprotein I antibodies (median, 27.6 SMU; 95%CI: 23.3-70.3 SMU, while two patients had IgG antibodies against this protein (titers, 33 and 78 SGU. Antiphospholipid antibodies were detected in only one healthy individual, who was seropositive for IgM anticardiolipin. We concluded that Brazilian individuals chronically infected with hepatitis C virus present a significant production of antiphospholipid antibodies, mainly IgA anti-β2-glycoprotein I antibodies, which are not associated with clinical manifestations of antiphospholipid syndrome.

  11. Fibrosing variant of Hashimoto thyroiditis is an IgG4 related disease.

    Science.gov (United States)

    Deshpande, Vikram; Huck, Amelia; Ooi, Esther; Stone, John H; Faquin, William C; Nielsen, G Petur

    2012-08-01

    Hashimoto thyroiditis (HT) and the fibrosing variant of Hashimoto thyroiditis (FVHT) are immune-mediated tumefactive lesions of the thyroid. Immunoglobulin G4-related disease (IgG4-RD) is now a widely recognised multi-organ system disease characterised by elevated serum and tissue concentrations of IgG4. In this study, the authors address several unresolved questions pertaining to the relationship between HT and FVHT, and the association of each of these diseases with IgG4-RD. The authors evaluated 28 consecutive cases of HT and nine cases of FVHT. The clinical, demographic and serological data were recorded. The slides were stained immunohistochemically using antibodies to IgG4 and IgG and the quantitative analysis was recorded. Data on thyroid function tests were available on seven cases of FVHT and 14 cases of HT. Based on the availability of data, hypothyroidism was noted in 62% (9/14) of HT and 86% of FVHT (6/7). FVHT demonstrated an exaggerated lobular pattern with lobules separated by cellular storiform-type fibrosis, resembling fibrosis seen in other forms of IgG-RD. The median IgG4 counts per high power field (×40) in HT and FVHT were 2.3 and 22, respectively. The median IgG4:IgG ratios in HT and FVHT were 0.11 and 0.58, respectively. The authors propose that FVHT belongs to the spectrum of IgG4-RD. Although a proportion of cases of HT show elevated numbers of IgG4 positive plasma cells, these cases lack the histological features typically associated with IgG4-RD, and thus the relationship between HT and IgG4-RD remains unproven.

  12. Thrombosis and antiphospholipid antibody syndrome during acute Q fever: A cross-sectional study.

    Science.gov (United States)

    Million, Matthieu; Bardin, Nathalie; Bessis, Simon; Nouiakh, Nadia; Douliery, Charlaine; Edouard, Sophie; Angelakis, Emmanouil; Bosseray, Annick; Epaulard, Olivier; Branger, Stéphanie; Chaudier, Bernard; Blanc-Laserre, Karine; Ferreira-Maldent, Nicole; Demonchy, Elisa; Roblot, France; Reynes, Jacques; Djossou, Felix; Protopopescu, Camelia; Carrieri, Patrizia; Camoin-Jau, Laurence; Mege, Jean-Louis; Raoult, Didier

    2017-07-01

    Q fever is a neglected and potentially fatal disease. During acute Q fever, antiphospholipid antibodies are very prevalent and have been associated with fever, thrombocytopenia, acquired heart valve disease, and progression to chronic endocarditis. However, thrombosis, the main clinical criterion of the 2006 updated classification of the antiphospholipid syndrome, has not been assessed in this context. To test whether thrombosis is associated with antiphospholipid antibodies and whether the criteria for antiphospholipid syndrome can be met in patients with acute Q fever, we conducted a cross-sectional study at the French National Referral Center for Q fever.Patients included were diagnosed with acute Q fever in our Center between January 2007 and December 2015. Each patient's history and clinical characteristics were recorded with a standardized questionnaire. Predictive factors associated with thrombosis were assessed using a rare events logistic regression model. IgG anticardiolipin antibodies (IgG aCL) assessed by an enzyme-linked immunosorbent assay were tested on the Q fever diagnostic serum. A dose-dependent relationship between IgG aCL levels and thrombosis was tested using a receiver operating characteristic (ROC) analysis.Of the 664 patients identified for inclusion in the study, 313 (47.1%) had positive IgG aCL and 13 (1.9%) were diagnosed with thrombosis. Three patients fulfilled the antiphospholipid syndrome criteria. After multiple adjustments, only positive IgG aCL (relative risk, 14.46 [1.85-113.14], P = .011) were independently associated with thrombosis. ROC analysis identified a dose-dependent relationship between IgG aCL levels and occurrence of thrombosis (area under curve, 0.83, 95%CI [0.73-0.93], P antiphospholipid antibodies are associated with thrombosis, thrombocytopenia, and acquired valvular heart disease. Antiphospholipid antibodies should be systematically assessed in acute Q fever patients. Hydroxychloroquine, which has been

  13. Charge-mediated Fab-Fc interactions in an IgG1 antibody induce reversible self-association, cluster formation, and elevated viscosity.

    Science.gov (United States)

    Arora, Jayant; Hu, Yue; Esfandiary, Reza; Sathish, Hasige A; Bishop, Steven M; Joshi, Sangeeta B; Middaugh, C Russell; Volkin, David B; Weis, David D

    Concentration-dependent reversible self-association (RSA) of monoclonal antibodies (mAbs) poses a challenge to their pharmaceutical development as viable candidates for subcutaneous delivery. While the role of the antigen-binding fragment (Fab) in initiating RSA is well-established, little evidence supports the involvement of the crystallizable fragment (Fc). In this report, a variety of biophysical tools, including hydrogen exchange mass spectrometry, are used to elucidate the protein interface of such non-covalent protein-protein interactions. Using dynamic and static light scattering combined with viscosity measurements, we find that an IgG1 mAb (mAb-J) undergoes RSA primarily through electrostatic interactions and forms a monomer-dimer-tetramer equilibrium. We provide the first direct experimental mapping of the interface formed between the Fab and Fc domains of an antibody at high protein concentrations. Charge distribution heterogeneity between the positively charged interface spanning complementarity-determining regions CDR3H and CDR2L in the Fab and a negatively charged region in C H 3/Fc domain mediates the RSA of mAb-J. When arginine and NaCl are added, they disrupt RSA of mAb-J and decrease the solution viscosity. Fab-Fc domain interactions between mAb monomers may promote the formation of large transient antibody complexes that ultimately cause increases in solution viscosity. Our findings illustrate how limited specific arrangements of amino-acid residues can cause mAbs to undergo RSA at high protein concentrations and how conserved regions in the Fc portion of the antibody can also play an important role in initiating weak and transient protein-protein interactions.

  14. Identification of conformational epitopes for human IgG on Chemotaxis inhibitory protein of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Furebring Christina

    2009-03-01

    Full Text Available Abstract Background The Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS blocks the Complement fragment C5a receptor (C5aR and formylated peptide receptor (FPR and is thereby a potent inhibitor of neutrophil chemotaxis and activation of inflammatory responses. The majority of the healthy human population has antibodies against CHIPS that have been shown to interfere with its function in vitro. The aim of this study was to define potential epitopes for human antibodies on the CHIPS surface. We also initiate the process to identify a mutated CHIPS molecule that is not efficiently recognized by preformed anti-CHIPS antibodies and retains anti-inflammatory activity. Results In this paper, we panned peptide displaying phage libraries against a pool of CHIPS specific affinity-purified polyclonal human IgG. The selected peptides could be divided into two groups of sequences. The first group was the most dominant with 36 of the 48 sequenced clones represented. Binding to human affinity-purified IgG was verified by ELISA for a selection of peptide sequences in phage format. For further analysis, one peptide was chemically synthesized and antibodies affinity-purified on this peptide were found to bind the CHIPS molecule as studied by ELISA and Surface Plasmon Resonance. Furthermore, seven potential conformational epitopes responsible for antibody recognition were identified by mapping phage selected peptide sequences on the CHIPS surface as defined in the NMR structure of the recombinant CHIPS31–121 protein. Mapped epitopes were verified by in vitro mutational analysis of the CHIPS molecule. Single mutations introduced in the proposed antibody epitopes were shown to decrease antibody binding to CHIPS. The biological function in terms of C5aR signaling was studied by flow cytometry. A few mutations were shown to affect this biological function as well as the antibody binding. Conclusion Conformational epitopes recognized by human antibodies

  15. The Fab Conformations in the Solution Structure of Human Immunoglobulin G4 (IgG4) Restrict Access to Its Fc Region

    Science.gov (United States)

    Rayner, Lucy E.; Hui, Gar Kay; Gor, Jayesh; Heenan, Richard K.; Dalby, Paul A.; Perkins, Stephen J.

    2014-01-01

    Human IgG4 antibody shows therapeutically useful properties compared with the IgG1, IgG2, and IgG3 subclasses. Thus IgG4 does not activate complement and shows conformational variability. These properties are attributable to its hinge region, which is the shortest of the four IgG subclasses. Using high throughput scattering methods, we studied the solution structure of wild-type IgG4(Ser222) and a hinge mutant IgG4(Pro222) in different buffers and temperatures where the proline substitution suppresses the formation of half-antibody. Analytical ultracentrifugation showed that both IgG4 forms were principally monomeric with sedimentation coefficients s20,w0 of 6.6–6.8 S. A monomer-dimer equilibrium was observed in heavy water buffer at low temperature. Scattering showed that the x-ray radius of gyration Rg was unchanged with concentration in 50–250 mm NaCl buffers, whereas the neutron Rg values showed a concentration-dependent increase as the temperature decreased in heavy water buffers. The distance distribution curves (P(r)) revealed two peaks, M1 and M2, that shifted below 2 mg/ml to indicate concentration-dependent IgG4 structures in addition to IgG4 dimer formation at high concentration in heavy water. Constrained x-ray and neutron scattering modeling revealed asymmetric solution structures for IgG4(Ser222) with extended hinge structures. The IgG4(Pro222) structure was similar. Both IgG4 structures showed that their Fab regions were positioned close enough to the Fc region to restrict C1q binding. Our new molecular models for IgG4 explain its inability to activate complement and clarify aspects of its stability and function for therapeutic applications. PMID:24876381

  16. Diagnostic Performance of Tuberculosis-Specific IgG Antibody Profiles in Patients with Presumptive Tuberculosis from Two Continents.

    Science.gov (United States)

    Broger, Tobias; Basu Roy, Robindra; Filomena, Angela; Greef, Charles H; Rimmele, Stefanie; Havumaki, Joshua; Danks, David; Schneiderhan-Marra, Nicole; Gray, Christen M; Singh, Mahavir; Rosenkrands, Ida; Andersen, Peter; Husar, Gregory M; Joos, Thomas O; Gennaro, Maria L; Lochhead, Michael J; Denkinger, Claudia M; Perkins, Mark D

    2017-04-01

    Development of rapid diagnostic tests for tuberculosis is a global priority. A whole proteome screen identified Mycobacterium tuberculosis antigens associated with serological responses in tuberculosis patients. We used World Health Organization (WHO) target product profile (TPP) criteria for a detection test and triage test to evaluate these antigens. Consecutive patients presenting to microscopy centers and district hospitals in Peru and to outpatient clinics at a tuberculosis reference center in Vietnam were recruited. We tested blood samples from 755 HIV-uninfected adults with presumptive pulmonary tuberculosis to measure IgG antibody responses to 57 M. tuberculosis antigens using a field-based multiplexed serological assay and a 132-antigen bead-based reference assay. We evaluated single antigen performance and models of all possible 3-antigen combinations and multiantigen combinations. Three-antigen and multiantigen models performed similarly and were superior to single antigens. With specificity set at 90% for a detection test, the best sensitivity of a 3-antigen model was 35% (95% confidence interval [CI], 31-40). With sensitivity set at 85% for a triage test, the specificity of the best 3-antigen model was 34% (95% CI, 29-40). The reference assay also did not meet study targets. Antigen performance differed significantly between the study sites for 7/22 of the best-performing antigens. Although M. tuberculosis antigens were recognized by the IgG response during tuberculosis, no single antigen or multiantigen set performance approached WHO TPP criteria for clinical utility among HIV-uninfected adults with presumed tuberculosis in high-volume, urban settings in tuberculosis-endemic countries. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  17. Conversion of a Mouse Fab into a Whole Humanized IgG Antibody for Detecting Botulinum Toxin

    National Research Council Canada - National Science Library

    Palys, Thomas J; Schmid, Kara E; Scherer, John M; Schoepp, Randal J

    2006-01-01

    .... Therefore we sought to convert a murine Fab into a whole humanized IgG. The variable regions from an anti-botulinum Fab were cloned into human IgG heavy and light chain vectors and produced in myeloma cells...

  18. Pertussis serology: assessment of IgG anti-PT ELISA for replacement of the CHO cell assay*

    Science.gov (United States)

    DALBY, TINE; SØRENSEN, CHARLOTTE; PETERSEN, JESPER WESTPHAL; KROGFELT, KAREN ANGELIKI

    2010-01-01

    Dalby T, Sørensen C, Petersen JW, Krogfelt KA. Pertussis serology: assessment of IgG anti-PT ELISA for replacement of the CHO cell assay. APMIS 2010; 118: 968–72. Two types of serological assays are commonly used for the assessment of pertussis vaccine-induced antibodies; the Chinese hamster ovary cell (CHO cell) assay and the immunoglobulin G (IgG) anti pertussis toxin (PT) enzyme-linked immunosorbent assay (IgG anti-PT ELISA). Recently, both the techniques have been modified to improve performance with sera with interfering activity (CHO cell assay) or with heat-treated sera (IgG anti-PT ELISA). These two improved techniques were compared by the analysis of 100 individual serum samples from a previous clinical trial and 213 sera from a longitudinal serum collection from 20 Danish adults recently vaccinated with the Danish acellular pertussis vaccine. The comparison showed a significant linear correlation between the results of the two assays with a p-value of ELISA can be used as a replacement for the often troublesome and time-consuming CHO cell assay for the measurement of vaccine-induced human antibodies to PT. PMID:21091778

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hirche TO

    2011-09-01

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

  1. Human IgG repertoire of malaria antigen-immunized human immune system (HIS) mice.

    Science.gov (United States)

    Nogueira, Raquel Tayar; Sahi, Vincent; Huang, Jing; Tsuji, Moriya

    2017-08-01

    Humanized mouse models present an important tool for preclinical evaluation of new vaccines and therapeutics. Here we show the human variable repertoire of antibody sequences cloned from a previously described human immune system (HIS) mouse model that possesses functional human CD4+ T cells and B cells, namely HIS-CD4/B mice. We sequenced variable IgG genes from single memory B-cell and plasma-cell sorted from splenocytes or whole blood lymphocytes of HIS-CD4/B mice that were vaccinated with a human plasmodial antigen, a recombinant Plasmodium falciparum circumsporozoite protein (rPfCSP). We demonstrate that rPfCSP immunization triggers a diverse B-cell IgG repertoire composed of various human VH family genes and distinct V(D)J recombinations that constitute diverse CDR3 sequences similar to humans, although low hypermutated sequences were generated. These results demonstrate the substantial genetic diversity of responding human B cells of HIS-CD4/B mice and their capacity to mount human IgG class-switched antibody response upon vaccination. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  2. The Scaffolding Protein Synapse-Associated Protein 97 is Required for Enhanced Signaling Through Isotype-Switched IgG Memory B Cell Receptors

    Science.gov (United States)

    Liu, Wanli; Chen, Elizabeth; Zhao, Xing Wang; Wan, Zheng Peng; Gao, Yi Ren; Davey, Angel; Huang, Eric; Zhang, Lijia; Crocetti, Jillian; Sandoval, Gabriel; Joyce, M. Gordon; Miceli, Carrie; Lukszo, Jan; Aravind, L.; Swat, Wojciech; Brzostowski, Joseph; Pierce, Susan K.

    2012-01-01

    Memory B cells are generated during an individual's first encounter with a foreign antigen and respond to re-encounter with the same antigen through cell surface immunoglobulin G (IgG) B cell receptors (BCRs) resulting in rapid, high-titered IgG antibody responses. Despite a central role for IgG BCRs in B cell memory, our understanding of the molecular mechanism by which IgG BCRs enhance antibody responses is incomplete. Here, we showed that the conserved cytoplasmic tail of the IgG BCR, which contains a putative PDZ-binding motif, associated with synapse-associated protein 97 (SAP97), a member of the PDZ domain–containing, membrane-associated guanylate-kinase family of scaffolding molecules that play key roles in controlling receptor density and signal strength at neuronal synapses. We showed that SAP97 accumulated and bound to IgG BCRs in the immune synapses that formed in response to engagement of the B cell with antigen. Knocking down SAP97 in IgG-expressing B cells or mutating the putative PDZ-binding motif in the tail impaired immune synapse formation, the initiation of IgG BCR signaling, and downstream activation of p38 mitogen-activated protein kinase. Thus, heightened B cell memory responses are encoded, in part, by a mechanism that involves SAP97 serving as a scaffolding protein in the IgG BCR immune synapse. PMID:22855505

  3. Development of mPMab-1, a Mouse-Rat Chimeric Antibody Against Mouse Podoplanin.

    Science.gov (United States)

    Yamada, Shinji; Kaneko, Mika K; Nakamura, Takuro; Ichii, Osamu; Konnai, Satoru; Kato, Yukinari

    2017-04-01

    Podoplanin (PDPN), the ligand of C-type lectin-like receptor-2, is used as a lymphatic endothelial marker. We previously established clone PMab-1 of rat IgG 2a as a specific monoclonal antibody (mAb) against mouse PDPN. PMab-1 is also very sensitive in immunohistochemical analysis; however, rat mAbs seem to be unfavorable for pathologists because anti-mouse IgG and anti-rabbit IgG are usually used as secondary antibodies in commercially available kits for immunohistochemical analysis. In this study, we develop a mouse-rat chimeric antibody, mPMab-1 of mouse IgG 2a , which was derived from rat PMab-1 mAb. Immunohistochemical analysis shows that mPMab-1 detects podocytes of the kidney, lymphatic endothelial cells of the colon, and type I alveolar cells of the lung. Importantly, mPMab-1 is more sensitive than PMab-1. This conversion strategy from rat mAb to mouse mAb could be applicable to other mAbs.

  4. Scanning force microscopy and fluorescence microscopy of microcontact printed antibodies and antibody fragments.

    Science.gov (United States)

    LaGraff, John R; Chu-LaGraff, Quynh

    2006-05-09

    Unlabeled primary immunoglobulin G (IgG) antibodies and its F(ab')2 and Fc fragments were attached to oxygen-plasma-cleaned glass substrates using either microcontact printing (MCP) or physical adsorption during bath application from dilute solutions. Fluorescently labeled secondary IgGs were then bound to surface-immobilized IgG, and the relative surface coverage was determined by measuring the fluorescence intensity. Results indicated that the surface coverage of IgG increased with increasing protein solution concentration for both MCP and bath-applied IgG and that a greater concentration of IgG was transferred to a glass substrate using MCP than during physisorption during bath applications. Scanning force microscopy (SFM) showed that patterned MCP IgG monolayers were 5 nm in height, indicating that IgG molecules lie flat on the substrate. After incubation with a secondary IgG, the overall line thickness increased to around 15 nm, indicating that the secondary IgG was in a more vertical orientation with respect to the substrate. The surface roughness of these MCP patterned IgG bilayers as measured by SFM was observed to increase with increasing surface coverage. Physisorption of IgG to both unmodified patterned polydimethylsiloxane (PDMS) stamps and plasma-cleaned glass substrates was modeled by Langmuir adsorption kinetics yielding IgG binding constants of K(MCP) = 1.7(2) x 10(7) M(-1) and K(bath) = 7.8(7) x 10(5) M(-1), respectively. MCP experiments involving primary F(ab')2 and Fc fragments incubated in fluorescently labeled fragment-specific secondary IgGs were carried out to test for the function and orientation of IgG. Finally, possible origins of MCP stamping defects such as pits, pull outs, droplets, and reverse protein transfer are discussed.

  5. Ventricular assist device elicits serum natural IgG that correlates with the development of primary graft dysfunction following heart transplantation.

    Science.gov (United States)

    See, Sarah B; Clerkin, Kevin J; Kennel, Peter J; Zhang, Feifan; Weber, Matthew P; Rogers, Kortney J; Chatterjee, Debanjana; Vasilescu, Elena R; Vlad, George; Naka, Yoshifumi; Restaino, Susan W; Farr, Maryjane A; Topkara, Veli K; Colombo, Paolo C; Mancini, Donna M; Schulze, P Christian; Levin, Bruce; Zorn, Emmanuel

    2017-08-01

    Pre-transplant sensitization is a limiting factor in solid-organ transplantation. In heart transplants, ventricular assist device (VAD) implantation has been associated with sensitization to human leukocyte antigens (HLA). The effect of VAD on non-HLA antibodies is unclear. We have previously shown that polyreactive natural antibodies (Nabs) contribute to pre-sensitization in kidney allograft recipients. Here we assessed generation of Nabs after VAD implantation in pre-transplant sera and examined their contribution to cardiac allograft outcome. IgM and IgG Nabs were tested in pre-transplant serum samples collected from 206 orthotopic heart transplant recipients, including 128 patients with VAD (VAD patients) and 78 patients without VAD (no-VAD patients). Nabs were assessed by testing serum reactivity to apoptotic cells by flow cytometry and to the generic oxidized epitope, malondialdehyde, by enzyme-linked immunosorbent assay. No difference was observed in serum levels of IgM Nabs between VAD and no-VAD patients. However, serum IgG Nabs levels were significantly increased in VAD compared with no-VAD patients. This increase was likely due to the presence of the VAD, as revealed by lower serum IgG Nabs levels before implantation. Elevated pre-transplant IgG Nabs level was associated with development of primary graft dysfunction (PGD). Our study demonstrates that VAD support elicits IgG Nabs reactive to apoptotic cells and oxidized epitopes. These findings further support broad and non-specific B-cell activation by VAD, resulting in IgG sensitization. Moreover, the association of serum IgG Nabs levels with development of PGD suggests a possible role for these antibodies in the inflammatory reaction accompanying this complication. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  6. Primary cytomegalovirus infection in pregnant Egyptian women confirmed by cytomegalovirus IgG avidity testing.

    Science.gov (United States)

    Kamel, N; Metwally, L; Gomaa, N; Sayed Ahmed, W A; Lotfi, M; Younis, S

    2014-01-01

    To determine the frequency of primary cytomegalovirus (CMV) infection in pregnant Egyptian women using CMV IgG avidity testing. A cross-sectional study was conducted at Suez Canal University Hospital, Ismailia, Egypt. A total of 546 pregnant women, presenting for routine antenatal screening, were tested for CMV IgG and IgM using a commercially available enzyme-linked immunosorbent assay (ELISA). Sera from CMV IgM-positive women were tested by CMV IgG avidity assay. All the 546 pregnant women were seropositive for anti-CMV IgG. Of the 546 women, 40 (7.3%) were positive or equivocal for IgM antibodies. All sera from the 40 women (IgG+/IgM+) showed a high or intermediate CMV IgG avidity index. Of the 40 women, 23 (57.5%) were in the second or third trimesters of pregnancy and had their first-trimester blood retrieved, and the tested CMV IgG avidity assay showed a high avidity index. Women who were IgM positive had no primary CMV infection in the index pregnancy as evidenced by the high CMV IgG avidity testing. © 2013 S. Karger AG, Basel.

  7. Biotin-avidin sandwich elisa with specific human isotypes IgG1 and IgG4 for Culicidae mosquito blood meal identification from an epizootic yellow fever area in Brazil

    Directory of Open Access Journals (Sweden)

    AM Marassá

    2009-01-01

    Full Text Available With a view toward investigating the feeding behavior of Culicidae mosquitoes from an area of epizootic yellow fever transmission in the municipalities of Garruchos and Santo Antônio das Missões, Rio Grande do Sul State, Brazil, specimens were collected by aspiration from September 2005 to April 2007. The engorged females were submitted to blood meal identification by enzyme-linked immunosorbent assay (ELISA. A total of 142 blood-engorged samples were examined for human or monkey blood through species-specific IgG. Additional tests for specificity utilizing isotypes IgG1 and IgG4 of human monoclonal antibodies showed that only anti-human IgG1 was effective in recognizing blood meals of human origin. The results indicated a significant difference (p = 0.027 in detection patterns in samples of Haemagogus leucocelaenus recorded from human blood meals at Santo Antônio das Missões, which suggests some degree of exposure, since it was an area where epizootic outbreaks have been reported.

  8. Measurement of spesific IgG to 14 foods in the serum of 32 alleric patients

    International Nuclear Information System (INIS)

    Zou Hanbing; Xu Yiping

    2006-01-01

    To evaluate the serum specific IgG to 14 food allergens in allergic patients, the food specific IgG was measured by ELISA in 32 allergic patients as well as 22 normal subjects. Results showed that the food specific IgG increased in 32 allergic patients. The positive rates for allergic patients were: shrimp: 34.4%, peanut:21.9%, egg:18.8%, crab:15.6%, wheat:12. 5%, ling:9.4%, corn:6.3%, soja:6.3%, beef:3.1%, mushroom:3.1%, tomato:3.1%, chicken:0, pork:0, rice:0. Only low increased levels of specific IgG to egg and pork in normal subjects were found with the same positive rate of 4.5% and the specific IgG to other food were negative. The fact that the food specific IgG increased in allergic disease patients means that not only IgE but also IgG could be prodused in allergic patients and there exists some relation between the two antibodies. It suggests that the measurement of food specific IgG in patients suffering from food allergy might be useful for diagnosis, prevention and treatment for such patients. (authors)

  9. Antibodies to sulfatide in leprosy and leprosy reactions

    NARCIS (Netherlands)

    Spierings, E.; de Vlieger, M.; Brand, A.; Klatser, P. R.; Ottenhoff, T. H.

    1999-01-01

    Antibodies to sulfatide have been reported in various demyelinating peripheral polyneuropathies. We have investigated the diagnostic value of these antibodies in leprosy. Anti-sulfatide IgM in leprosy patients was not significantly elevated. High anti-sulfatide IgG titers were observed in

  10. N-Linked Glycosylation is an Important Parameter for Optimal Selection of Cell Lines Producing Biopharmaceutical Human IgG

    NARCIS (Netherlands)

    van Berkel, Patrick H. C.; Gerritsen, Jolanda; Perdok, Gerrard; Valbjorn, Jesper; Vink, Tom; van de Winkel, Jan G. J.; Parren, Paul W. H. I.

    2009-01-01

    We studied the variations in N-linked glycosylation of human IgG molecules derived from 105 different stable cell lines each expressing one of the six different antibodies. Antibody expression was based on glutamine synthetase selection technology in suspension growing CHO-KISV cells. The glycans

  11. Detection of acute inflammation with 111In-labeled nonspecific polyclonal IgG

    International Nuclear Information System (INIS)

    Fischman, A.J.; Rubin, R.H.; Khaw, B.A.

    1988-01-01

    The detection of focal sites of inflammation is an integral part of the clinical evaluation of the febrile patient. When anatomically distinct abscesses are present, lesion detection can be accomplished by standard radiographic techniques, particularly in patients with normal anatomy. At the phlegmon stage, however, and in patients who have undergone surgery, these techniques are considerably less effective. While radionuclide methods, such as Gallium-67 (67Ga)-citrate and Indium-111 (111In)-labeled WBCs have been relatively successful for the detection of early inflammation, neither approach is ideal. In the course of studies addressing the use of specific organism-directed antibodies for imaging experimental infections in animals, we observed that nonspecific polyclonal immunoglobulin G (IgG) localized as well as specific antibodies. Preliminary experiments suggested that the Fc portion of IgG is necessary for effective inflammation localization. Since polyclonal IgG in gram quantities has been safely used for therapy in patients with immune deficiency states, we decided to test whether milligram quantities of radiolabeled IgG could image focal sites of inflammation in humans. Thus far, we have studied a series of 84 patients with suspected lesions in the abdomen, pelvis, vascular grafts, lungs, or bones/joints. In 48 of 52 patients with focal lesions detected by surgery, computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound (US), the IgG scan correctly localized the site, while 31 patients without focal inflammation had no abnormal focal localization of the radiopharmaceutical. Four patients had false negative scans and one patient had a false positive scan. For this small series, the overall sensitivity and specificity were 92% and 95%, respectively. In this report, we review our experience with this exciting new agent

  12. SEROPREVALANCE OF TOXOPLASMA IgG AMONG PREGNANT WOMEN IN THE PROVINCE OF HATAY AND CONTRIBUTION OF AVIDITY TEST TO THE DIAGNOSE

    Directory of Open Access Journals (Sweden)

    Ayşe Güler Okyay

    2013-09-01

    Full Text Available Objective: Toxoplasma gondii, an obligate intracellular parasite, is a common zoonosis in the world and causes toxoplasmosis. The infection is usually asymptomatic and if it occurs during pregnancy it may cause congenital anomalies, miscarriage, stillbirth and premature delivery. In this study, determination of seroprevalance of Toxoplazma IgG and IgM among pregnant women in the province of Hatay was aimed. In addition, IgG avidity test was performed in subjects who had positive test results for both of the two antibodies. Design: In this study, 3340 pregnant women who admitted to the outpatient clinic of gynecelogy and obstetrics department of Mustafa Kemal University/Hatay between the years of 2007 and 2012were included. Toxoplazma IgM and IgG antibody test results of the subjects were examined retrospectively by screening the records of microbiology laboratory of the hospital. Additionally, IgG avidity test was performed in 114 cases whoose test results for both Toxoplazma IgM and IgG were positive. Main outcome measures: IgM and IgG seropositivity rates were found as 3.6% (n = 120 and 57% (n = 1910, respectively. The rate of new infection was detected with avidity test as 31%. Conclusions: Remarkably high seropositivity rate was observed in the Mediterranean region especially in the province of Hatay. Antibody testing for Toxoplasma gondii may be useful during routine examinations of women who are in the first trimester of pregnancy and who plan gestation. In addition, measures should be taken to raise awareness of hygiene in our region in terms of water and sanitation.

  13. Passive transfer with serum and IgG antibodies of irradiated cercaria-induced resistance against Schistosoma mansoni in mice

    International Nuclear Information System (INIS)

    Mangold, B.L.; Dean, D.A.

    1986-01-01

    The role of humoral immunity to Schistosoma mansoni infection in C57BL/6J mice was examined by employing a passive transfer system. Sera from highly resistant mice that had been exposed to two or three immunizations with 50-kilorad-gamma-irradiated cercariae were tested for their ability to transfer protection against S. mansoni challenge. All five batches of serum tested were observed to have protective activity. Immune serum recipients exhibited statistically significant reductions in challenge worm burdens of 20 to 50% compared with recipients of normal serum or no serum. The most consistent level of resistance was obtained when immune serum was administered several days post-challenge, i.e., at a time coincident with schistosomulum residence in the lungs. Furthermore, it was shown that the protective activity in immune serum was associated with factors that bind to staphylococcal protein A and that are precipitated by 50% ammonium sulfate; thus it appears that the protective factors in immune serum are IgG antibodies

  14. Histopathology of IgG4-Related Autoimmune Hepatitis and IgG4-Related Hepatopathy in IgG4-Related Disease.

    Science.gov (United States)

    Nakanuma, Yasuni; Ishizu, Yoji; Zen, Yoh; Harada, Kenichi; Umemura, Takeji

    2016-08-01

    Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease involving many organs; it includes IgG4-related sclerosing cholangitis and inflammatory pseudotumor in the hepatobiliary system. Two types of hepatic parenchymal involvement have been reported in IgG4-RD: IgG4-related autoimmune hepatitis (AIH) and IgG4-hepatopathy. Moreover, only three cases of IgG4-related AIH have been reported. Immunoglobulin G4-related AIH is clinicopathologically similar to AIH, except for an elevated serum IgG4 level and heavy infiltration of IgG4-positive plasma cells in the liver tissue. Interestingly, IgG4-related AIH can be complicated by well-known IgG4-RD(s). Immunoglobulin G4-hepatopathy, which includes various histopathological lesions encountered in the liver of patients with type I autoimmune pancreatitis, is classified into five histological categories: portal inflammation, large bile duct damage, portal sclerosis, lobular hepatitis, and cholestasis. Immunoglobulin G4-hepatopathy is currently a collective term covering hepatic lesions primarily or secondarily related to IgG4-related sclerosing cholangitis and type 1 autoimmune pancreatitis. In conclusion, the liver is not immune to IgG4-RD, and at least two types of hepatic involvement in IgG4-RD have been reported: IgG4-related AIH and IgG4-hepatopathy. Additional studies are required to clarify their precise clinical significance with respect to IgG4-RD and inherent liver diseases. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. Comparison of allergenicity and immunogenicity of an intact allergen vaccine and commercially available allergoid products for birch pollen immunotherapy.

    Science.gov (United States)

    Lund, L; Henmar, H; Würtzen, P A; Lund, G; Hjortskov, N; Larsen, J N

    2007-04-01

    Specific immunotherapy with intact allergen vaccine is a well-documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10-year period did not indicate increased safety of allergoids over intact allergens. The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine. Solid-phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose. IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen-specific IgG responses in mice. While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid

  16. Seroprevalence of immunoglobulin G antibody to parvovirus B19 in Ontario

    Science.gov (United States)

    Wasfy, Samia; Nishikawa, John; Petric, Martin

    1996-01-01

    The prevalence of antibody to parvovirus B19 was assessed in two populations. In a group of 494 residents from Ontario and the Maritimes, virus-specific immunoglobulin (Ig) M antibody, a marker of acute infection, was found throughout the year but was most prevalent during the late winter and early spring months. The overall prevalence of IgG antibody in this group was 30.3%. In an effort to examine age-specific prevalence in this population, a second group of sera from 210 pediatric patients at The Hospital for Sick Children, Toronto, Ontario and from Red Cross blood donors was tested for the presence of B19-specific IgG, and of these, 31.4% of the samples were positive. This prevalence varied from 3.3% in the under five-year-old age group to 66.7% in the 35- to 45-year-old age group. Eighty per cent of sera from females of this group were seropositive. This study provides insight into the prevalence of parvovirus B19 IgG antibody in the population. PMID:22514456

  17. Immune thrombocytopenia. Use of a Coombs antiglobulin test to detect IgG and C3 on platelets

    International Nuclear Information System (INIS)

    Cines, D.B.; Schreiber, A.D.

    1979-01-01

    We applied a radiolabeled Coombs antiglobulin test to the diagnosis and management of immune thrombocytopenia in adults and children. This assay substantiated that the majority of patients with idiopathic thrombocytopenic purpura have increased levels of IgG on their platelets. Platelets from a patient with the post-transfusion-purpura syndrome also carried increased IgG, indicating a role for IgG antibody or IgG-containing immune complexes in the destruction of host platelets in this disease. The radiolabeled Coombs test provides a general means to help diagnose, manage, and study immune platelet disorders

  18. Human IgG is produced in a pro-form that requires clipping of C-terminal lysines for maximal complement activation

    DEFF Research Database (Denmark)

    van den Bremer, E. T. J.; Beurskens, F. J.; Voorhorst, M.

    2015-01-01

    Human IgG is produced with C-terminal lysines that are cleaved off in circulation. The function of this modification was unknown and generally thought not to affect antibody function. We recently reported that efficient C1q binding and complement-dependent cytotoxicity (CDC) requires IgG hexameri...

  19. Lack of IgG antibody seropositivity to Borrelia burgdorferi in patients with Parry-Romberg syndrome and linear morphea en coup de sabre in Mexico.

    Science.gov (United States)

    Gutiérrez-Gómez, Claudia; Godínez-Hana, Ana L; García-Hernández, Marisela; Suárez-Roa, María de Lourdes; Toussaint-Caire, Sonia; Vega-Memije, Elisa; Gutiérrez-Mendoza, Daniela; Pérez-Dosal, Marcia; Medina-De la Garza, Carlos E

    2014-08-01

    Progressive hemifacial atrophy or Parry-Romberg Syndrome (PRS) is a rare, acquired, progressive dysplasia of subcutaneous tissue and bone characterized by unilateral facial involvement. Its etiology is unknown, but theories about its pathogenesis include infectious, degenerative, autoimmune, and traumatic causes among others. The causal relationship of PRS and linear morphea en coup de sabre (LMCS) with Borrelia burgdorferi infection remains controversial. Our goal was to serologically determine anti-B. burgdorferi antibodies in patients diagnosed with PRS and LMCS to establish a possible association as a causative agent. We conducted a serology study with patients belonging to a group of 21 individuals diagnosed with PRS, six with LMCS, and 21 matched controls. Anti-Borrelia IgG antibodies were determined by ELISA. A descriptive statistical analysis and Fischer's exact test were done. In serological tests, only two cases had borderline values and were further analyzed by Western blot with non-confirmatory results. For both the PRS and LMCS group, the association test was not significant, suggesting a lack of association between PRS or LMCS and the presence of anti-Borrelia antibodies. In Mexico there are no previous studies on Borrelia infection and its relationship between PRS or LMCS. Our result showed a lack of association of either clinical entities with anti-Borrelia-antibodies. Former reports of this association may suggest coincidental findings without causal relationship. © 2014 The International Society of Dermatology.

  20. Application of 99mTc-labeled chimeric Fab fragments of monoclonal antibody A7 for radioimmunoscintigraphy of pancreatic cancer

    International Nuclear Information System (INIS)

    Matsumura, Hiroomi

    1999-01-01

    Pancreatic cancer is one of the most lethal diseases and its prognosis is still poor. To improve the survival rate, it is essential to develop new technologies for early and definitive diagnosis. In this study, chimeric Fab fragments of monoclonal antibody A7 were successfully radio-labeled with 99m Tc, preventing depression of the antigen-binding activity. 99m Tc-labeled monoclonal antibody A7, 99m Tc-labeled chimeric Fab fragments of monoclonal antibody A7, 99m Tc-labeled normal mouse IgG and 99m Tc-labeled Fab fragments of normal mouse IgG were injected intravenously into nude mice bearing human pancreatic cancer xenografts and the radioactivity was subsequently measured. The tumor accumulation was significantly higher with labeled monoclonal antibody A7 than with normal mouse IgG, and higher with chimeric Fab fragments of monoclonal antibody A7 than with Fab fragments of normal mouse IgG. The tumor/blood ratio of radioactivity increased rapidly over time with chimeric Fab fragments of monoclonal antibody A7. These results suggest that chimeric Fab fragments of monoclonal antibody A7 may be useful for diagnosing pancreatic cancer by means of radioimmunoscintigraphy. (author)

  1. Monoclonal antibody PAL-E specific for endothelium

    NARCIS (Netherlands)

    Schlingemann, R. O.; Dingjan, G. M.; Emeis, J. J.; Blok, J.; Warnaar, S. O.; Ruiter, D. J.

    1985-01-01

    A monoclonal antibody, PAL-E, is described that is specific for endothelial cells. The monoclonal antibody, an IgG2a, markedly stains endothelium of capillaries, medium-sized and small veins, and venules in frozen sections of human and some animal tissues tested. It reacts not at all or only weakly

  2. An enzyme-linked immuno-filtration assay used to compare infant and maternal antibody profiles in toxoplasmosis.

    Science.gov (United States)

    Pinon, J M; Thoannes, H; Gruson, N

    1985-02-28

    Enzyme-linked immuno-filtration assay is carried out on a micropore membrane. This doubly analytical technique permits simultaneous study of antibody specificity by immunoprecipitation and characterisation of antibody isotypes by immuno-filtration with enzyme-labelled antibodies. Recognition of the same T. gondii antigenic constituent by IgG, IgA, IgM or IgE antibodies produces couplets (IgG-IgM; IgG-IgA) or triplets (IgG-IgM-IgA; IgG-IgM-IgE) which identify the functional fractions of the toxoplasmosis antigen. In acquired toxoplasmosis, the persistence of IgM antibody long after infestation puts in question the implication of recent infestation normally linked to detection of this isotype. For sera of comparable titres, comparison of immunological profiles by the method described demonstrates disparities in the composition of the specific antibody content as expressed in international units. Use of the same method to detect IgM antibodies or distinguish between transmitted maternal IgG and IgG antibodies synthesised by the foetus or neonate makes a diagnosis of congenital toxoplasmosis possible in 85% of cases during the first few days of life. With the method described the diagnosis may be made on average 5 months earlier than with classical techniques. In the course of surveillance for latent congenital toxoplasmosis, the appearance of IgM or IgE antibodies raises the possibility of complications (hydrocephalus, chorioretinitis). After cessation of treatment, a rise in IgG antibodies indicating persistence of infection is detected earlier by the present than by classical methods.

  3. Serum antibody responses in pigs trickle-infected with Ascaris and Trichuris: Heritabilities and associations with parasitological findings.

    Science.gov (United States)

    Kringel, Helene; Thamsborg, Stig Milan; Petersen, Heidi Huus; Göring, Harald Heinz Herbert; Skallerup, Per; Nejsum, Peter

    2015-07-30

    A humoral immune response following helminth infection in pigs is well documented. However, it has been difficult to confirm the existence of antibody mediated resistance against the large roundworm, Ascaris suum, and whipworm, Trichuris suis, in experimental settings by correlating worm burdens or egg excretion with specific antibody levels. We set out to investigate the association between worm load and T. suis and A. suum specific serum antibody levels (IgG1, IgG2 and IgA) against excretory-secretory products of adults and third stage larvae, respectively, measured at 0, 7 and 14 weeks p.i. in a trickle-infected F1-resource-population of crossbred pigs (n=195). Furthermore, we wanted to determine the heritability of these antibody isotypes during the course of infection. Most pigs remained infected with A. suum throughout the experiment while they expelled T. suis between 7 and 14 weeks post infection (p.i.). Parasite specific IgG1 and IgA were significantly (P<0.001) elevated after 7 and 14 weeks of infection, whereas parasite specific IgG2 levels only changed slightly at 14 weeks p.i.. However, the observed association between specific antibody isotype levels and faecal egg counts and macroscopic worm load was weak. The relative heritabilities of the different parasite specific isotypes were assessed and resulted in significant heritability estimates for parasite specific IgG1 and IgA. The highest heritabilities were found for A. suum specific IgG1 (h(2)=0.41 and 0.46 at 7 and 14 weeks p.i., respectively). Thus, the present study demonstrates that host genetic factors influence the IgG1 and IgA antibody isotype responses specific to two of the most common gastrointestinal nematodes of swine whereas specific antibody levels were poorly associated with egg excretion and the presence of macroscopic worms. Copyright © 2015. Published by Elsevier B.V.

  4. Serum total IgG and IgG4 levels in thyroid eye disease

    Directory of Open Access Journals (Sweden)

    Sy A

    2016-10-01

    Full Text Available Aileen Sy, Rona Z Silkiss Department of Ophthalmology, California Pacific Medical Center, San Francisco, CA, USA Purpose: To investigate the relationship between immunoglobulin G (IgG4-related disease (IgG4-RD and thyroid eye disease (TED with respect to IgG levels. Patients and methods: A retrospective review of total IgG, IgG subclass, and thyroid stimulating immunoglobulin (TSI levels in 24 patients with TED. Results: Five patients (20.8% demonstrated serum IgG4 levels consistent with IgG4-RD without any additional systemic disease. Total IgG and IgG subclass levels were found to be an inadequate proxy for TSI elevation. Conclusion: There may be a subtype of TED patients with elevated IgG4 in the absence of IgG4-RD systemic findings. Keywords: thyroid eye disease, IgG subclass, IgG4, Graves’ disease, Graves’ ophthalmopathy, IgG4-RD

  5. From hybridomas to a robust microalgal-based production platform: molecular design of a diatom secreting monoclonal antibodies directed against the Marburg virus nucleoprotein.

    Science.gov (United States)

    Hempel, Franziska; Maurer, Michael; Brockmann, Björn; Mayer, Christian; Biedenkopf, Nadine; Kelterbaum, Anne; Becker, Stephan; Maier, Uwe G

    2017-07-27

    The ideal protein expression system should provide recombinant proteins in high quality and quantity involving low production costs only. However, especially for complex therapeutic proteins like monoclonal antibodies many challenges remain to meet this goal and up to now production of monoclonal antibodies is very costly and delicate. Particularly, emerging disease outbreaks like Ebola virus in Western Africa in 2014-2016 make it necessary to reevaluate existing production platforms and develop robust and cheap alternatives that are easy to handle. In this study, we engineered the microalga Phaeodactylum tricornutum to produce monoclonal IgG antibodies against the nucleoprotein of Marburg virus, a close relative of Ebola virus causing severe hemorrhagic fever with high fatality rates in humans. Sequences for both chains of a mouse IgG antibody were retrieved from a murine hybridoma cell line and implemented in the microalgal system. Fully assembled antibodies were shown to be secreted by the alga and antibodies were proven to be functional in western blot, ELISA as well as IFA studies just like the original hybridoma produced IgG. Furthermore, synthetic variants with constant regions of a rabbit IgG and human IgG with optimized codon usage were produced and characterized. This study highlights the potential of microalgae as robust and low cost expression platform for monoclonal antibodies secreting IgG antibodies directly into the culture medium. Microalgae possess rapid growth rates, need basically only water, air and sunlight for cultivation and are very easy to handle.

  6. An Adult Case of Recurrent Guillain-Barré Syndrome with Anti-galactocerebroside Antibodies

    Science.gov (United States)

    Takahashi, Hisashi; Kimura, Tadashi; Yuki, Natsuko; Yoshioka, Akira

    2017-01-01

    A 79-year-old woman with a history of Guillain-Barré syndrome (GBS) developed somnolence and tetraparesis after pneumonia. Based on clinical and laboratory findings, she was diagnosed with complications of acute inflammatory demyelinating polyneuropathy (AIDP) and acute disseminated encephalomyelitis (ADEM). Anti-galactocerebroside (Gal-C) IgG antibodies were detected in her serum. Cases of recurrent GBS in patients who are positive for this antibody are extremely rare. The anti-Gal-C IgG antibodies likely played an important role in the pathogenesis of the AIDP and ADEM. PMID:29093388

  7. Seroprevalence of toxoplasma-specific antibodies in patients suspected to have active toxoplasmosis: A cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Abbas Ali Eskandarian

    2014-01-01

    Full Text Available Background: The aim of this study was to investigate the presence and distribution of anti-toxoplasma-specific IgM and IgG tantibodies in patients suspected to have toxoplasmosis and investigate for any association between IgM and IgG antibodies and some toxoplasmosis risk factors as well. Materials and Methods: In a comparative cross-sectional study, 70 patients suspected to had active toxoplasmosis and 30 control volunteers, who gave informed consent, entered the study. In each group, patient age, sex, signs of appearance, education level, residency status (urban / rural, occupation, frequency of toxoplasma-specific IgG and IgM antibodies, abortion history, and some risk factors (Direct cat exposure, Occupational exposure to raw meat, and Raw vegetable consumption were recorded. The enzyme-linked immunosorbent assay (ELISA kits (EUROIMMUN®, United Kingdom were used for the evaluation of anti-toxoplasma IgG and IgM antibodies according to the manufacturer›s instructions. All analyses were done using SPSS-20. Results: The frequency of toxoplasma-specific IgG and IgM antibodies like: Direct cat exposures, Occupational exposure to raw meat, and Raw vegetable consumption were not statistically significant between the two groups (P > 0.05. The history of previous abortions in women in the toxoplasmosis-suspected group was significantly higher than that in the controls (31.4% versus 6.7%; P = 0.009. Conclusion: The frequency of specific IgM and IgG antibodies in toxoplasmosis suspected in the toxoplasmosis and control groups was not statistically significant.

  8. An immunochemical method for the quantitation of insulin antibodies

    International Nuclear Information System (INIS)

    Reeves, W.G.; Kelly, U.

    1980-01-01

    A 125 I-labelled insulin binding assay is described in which IgG antibody is precipitated by the addition of an optimal concentration of second antibody. Other features include the removal of unlabelled insulin from test sera prior to assay and the use of 22 Na as a volume marker. This approach overcomes problems associated with previous assays for insulin antibodies. Clear differences are seen in the IgG insulin binding capacity (IBC) of sera from patients with insulin resistance and injection site lipo-atrophy when compared with insulin-treated diabetics who lack such complications. The precision and flexibility of this technique make it particularly suitable for studies of the immune response to different species and forms of insulin. (Auth.)

  9. Analytical FcRn affinity chromatography for functional characterization of monoclonal antibodies

    Science.gov (United States)

    Schlothauer, Tilman; Rueger, Petra; Stracke, Jan Olaf; Hertenberger, Hubert; Fingas, Felix; Kling, Lothar; Emrich, Thomas; Drabner, Georg; Seeber, Stefan; Auer, Johannes; Koch, Stefan; Papadimitriou, Apollon

    2013-01-01

    The neonatal Fc receptor (FcRn) is important for the metabolic fate of IgG antibodies in vivo. Analysis of the interaction between FcRn and IgG in vitro might provide insight into the structural and functional integrity of therapeutic IgG that may affect pharmacokinetics (PK) in vivo. We developed a standardized pH gradient FcRn affinity liquid chromatography method with conditions closely resembling the physiological mechanism of interaction between IgG and FcRn. This method allows the separation of molecular IgG isoforms, degradation products and engineered molecules based on their affinity to FcRn. Human FcRn was immobilized on the column and a linear pH gradient from pH 5.5 to 8.8 was applied. FcRn chromatography was used in comparison to surface plasmon resonance to characterize different monoclonal IgG preparations, e.g., oxidized or aggregated species. Wild-type and engineered IgGs were compared in vitro by FcRn chromatography and in vivo by PK studies in huFcRn transgenic mice. Analytical FcRn chromatography allows differentiation of IgG samples and variants by peak pattern and retention time profile. The method can distinguish: 1) IgGs with different Fabs, 2) oxidized from native IgG, 3) aggregates from monomer and 4) antibodies with mutations in the Fc part from wild-type IgGs. Changes in the FcRn chromatographic behavior of mutant IgGs relative to the wild-type IgG correlate to changes in the PK profile in the FcRn transgenic mice. These results demonstrate that FcRn affinity chromatography is a useful new method for the assessment of IgG integrity. PMID:23765230

  10. Antibody dynamics in BRSV-infected Danish dairy herds as determined by isotype-specific immunoglobulins

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Larsen, Lars Erik; Philipsen, J.S.

    2000-01-01

    Using specific ELISAs, antibody levels of four different isotypes to bovine respiratory syncytial virus (BRSV) were determined in calves, following experimental BRSV infection. Most calves experienced an increase in the specific IgM and IgG1 titres about 6-10 days after infection with BRSV. The Ig......M titre was transient showing positive titres for only 5-10 days, while specific IgG1 was present for a longer time. IgA was detected concomitantly with IgM but at a lower level. Production of IgG2 anti-BRSV antibodies was detected from 3 weeks after infection. In two closed herds, repeated blood......, another herd with acute BRSV was followed by weekly blood samples in six calves; in both herds IgM and IgG1 was detected shortly after the appearance of clinical signs. Serum samples from 50 Danish dairy herds (453 samples) were tested for immunoglobulins of the isotypes IgG1, IgG2 and IgM. The presence...

  11. Survey of malaria and anti-dengue virus IgG among febrile HIV-infected patients attending a tertiary hospital in Abuja, Nigeria.

    Science.gov (United States)

    Mustapha, Jelili Olaide; Emeribe, Anthony Uchenna; Nasir, Idris Abdullahi

    2017-01-01

    Dengue and malaria are infections, of great public health concern, especially in sub-Saharan Africa where the burden of HIV infection is high. This study was conducted to determine the seroprevalence of dengue virus IgG antibodies and dengue/malaria coinfection among febrile HIV-infected patients attending the University of Abuja Teaching Hospital, Gwagwalada, Abuja. In this cross-sectional study, blood samples from 178 consenting HIV-infected patients receiving antiretroviral therapy were collected and tested for plasmodiasis and anti-Dengue virus IgG using malaria microscopy and ELISA, respectively. Interviewer-based questionnaires were used to assess subjects' sociodemographic variables and dengue risk factors. Of the 178 screened participants, 44.4% were seropositive for dengue virus IgG antibody, whereas 29.2% were positive for Plasmodium falciparum. About 44.2% were positive for both dengue virus and P. falciparum . There was a statistical association between anti-dengue IgG and occupation ( p =0.03) but not with age, residential area, educational level and patients' gender ( p >0.05). Seroprevalence of anti-dengue specific IgG was relatively higher in participants who adopted protective measures. There was a statistical association between seroprevalence of anti-dengue IgG and adoption of preventive measures ( p <0.05). The high prevalence of malaria and dengue virus IgG indicates the need to strengthen vector control and dengue surveillance programs.

  12. Neuromyelitis optica spectrum disorders: comparison of clinical and magnetic resonance imaging characteristics of AQP4-IgG versus MOG-IgG seropositive cases in the Netherlands.

    Science.gov (United States)

    van Pelt, E D; Wong, Y Y M; Ketelslegers, I A; Hamann, D; Hintzen, R Q

    2016-03-01

    Neuromyelitis optica spectrum disorders (NMOSDs) are a group of rare inflammatory demyelinating disorders of the central nervous system. The identification of specific antibodies directed to aquaporin 4 (AQP4-IgG) led to the distinction from multiple sclerosis. However, up to 25% of the clinically diagnosed NMO patients are seronegative for AQP4-IgG. A subgroup of these patients might be identified by antibodies directed to myelin oligodendrocyte glycoprotein (MOG-IgG). Our objective was to investigate whether the clinical characteristics of these patients differ. Using a cell-based assay, samples of 61 AQP4-IgG seronegative patients and 41 AQP4-IgG seropositive patients with clinically NMOSD were analysed for the presence of MOG-IgG. Clinical characteristics of the AQP4-IgG, MOG-IgG seropositive and double seronegative NMOSD patients were compared. Twenty of the 61 AQP4-IgG seronegative patients tested MOG-IgG seropositive (33%). MOG-IgG seropositive patients were more frequently males in contrast to AQP4-IgG seropositive patients (55% vs. 15%, P < 0.01) and Caucasians (90% vs. 63%, P = 0.03). They more frequently presented with coincident optic neuritis and transverse myelitis (40% vs. 12%, P = 0.02) and had a monophasic disease course (70% vs. 29%, P < 0.01). AQP4-IgG seropositive patients were 2.4 times more likely to suffer from relapses compared with MOG-IgG seropositive patients (relative risk 2.4, 95% confidence interval 1.2-4.7). AQP4-IgG seropositive patients had higher Expanded Disability Status Scale levels at last follow-up (P < 0.01). Antibodies directed to MOG identify a subgroup of AQP4-IgG seronegative NMO patients with generally a favourable monophasic disease course. © 2015 EAN.

  13. Oriented immobilized anti-hIgG via F(c) fragment-imprinted PHEMA cryogel for IgG purification.

    Science.gov (United States)

    Bereli, Nilay; Ertürk, Gizem; Tümer, M Aşkin; Say, Ridvan; Denizli, Adil

    2013-05-01

    Antibodies are used in many applications, especially as diagnostic and therapeutic agents. Among the various techniques used for the purification of antibodies, immunoaffinity chromatography is by far the most common. For this purpose, oriented immobilization of antibodies is an important step for the efficiency of purification step. In this study, F(c) fragment-imprinted poly(hydroxyethyl methacrylate) cryogel (MIP) was prepared for the oriented immobilization of anti-hIgG for IgG purification from human plasma. Non-imprinted poly(hydroxyethyl methacrylate) cryogel (NIP) was also prepared for random immobilization of anti-hIgG to compare the adsorption capacities of oriented (MIP/anti-hIgG) and random (NIP/anti-hIgG) cryogel columns. The amount of immobilized anti-hIgG was 19.8 mg/g for the NIP column and 23.7 mg/g for the MIP column. Although the amount of immobilized anti-hIgG was almost the same for the NIP and MIP columns, IgG adsorption capacity was found to be three times higher than the NIP/anti-hIgG column (29.7 mg/g) for the MIP/anti-hIgG column (86.9 mg/g). Higher IgG adsorption capacity was observed from human plasma (up to 106.4 mg/g) with the MIP/anti-hIgG cryogel column. Adsorbed IgG was eluted using 1.0 M NaCl with a purity of 96.7%. The results obtained here are very encouraging and showed the usability of MIP/anti-hIgG cryogel prepared via imprinting of Fc fragments as an alternative to conventional immunoaffinity techniques for IgG purification. Copyright © 2012 John Wiley & Sons, Ltd.

  14. Antibody index and specific antibody quotient in horses after intragastric administration of Sarcocystis neurona sporocysts.

    Science.gov (United States)

    Heskett, Katherine A; Mackay, Robert J

    2008-03-01

    To investigate the use of a specific antibody index (AI) that relates Sarcocystis neurona-specific IgG quotient (Q(SN)) to total IgG quotient (Q(IgG)) for the detection of the anti-S neurona antibody fraction of CNS origin in CSF samples obtained from horses after intragastric administration of S neurona sporocysts. 18 adult horses. 14 horses underwent intragastric inoculation (day 0) with S neurona sporocysts, and 4 horses remained unchallenged; blood and CSF samples were collected on days - 1 and 84. For purposes of another study, some challenged horses received intermittent administration of ponazuril (20 mg/kg, PO). Sarcocystis neurona-specific IgG concentrations in CSF (SN(CSF)) and plasma (SN(plasma)) were measured via a direct ELISA involving merozoite lysate antigen and reported as ELISA units (EUs; arbitrary units based on a nominal titer for undiluted immune plasma of 100,000 EUs/mL). Total IgG concentrations in CSF (IgG(CSF)) and plasma (IgG(plasma)) were quantified via a sandwich ELISA and a radial immunodiffusion assay, respectively; Q(SN), Q(IgG), and AI were calculated. Following sporocyst challenge, mean +/- SEM SN(CSF) and SN(plasma) increased significantly (from 8.8 +/- 1.0 EUs/mL to 270.0 +/- 112.7 EUs/mL and from 1,737 +/- 245 EUs/mL to 43,169 +/- 13,770 EUs/mL, respectively). Challenge did not affect total IgG concentration, Q(SN), Q(IgG), or AI. S neurona-specific IgG detected in CSF samples from sporocyst-challenged horses appeared to be extraneural in origin; thus, this experimental challenge may not reliably result in CNS infection. Calculation of a specific AI may have application to the diagnosis of S neurona-associated myeloencephalitis in horses.

  15. A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

    International Nuclear Information System (INIS)

    Qi, Zhi; Pan, Chungen; Lu, Hong; Shui, Yuan; Li, Lin; Li, Xiaojuan; Xu, Xueqing; Liu, Shuwen; Jiang, Shibo

    2010-01-01

    Research highlights: → One recombinant mimetics of gp41 prehairpin fusion intermediate (PFI) consisting of gp41 N46 sequence, foldon and IgG Fc, designated N46FdFc, was expressed. → N46FdFc-induced antibodies in mice that neutralized HIV-1 infection, inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. → These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines. -- Abstract: HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.

  16. Anti Helicobacter pylori IgG and IgA response in patients with gastric cancer and chronic gastritis.

    Science.gov (United States)

    Manojlovic, Nebojsa; Babic, Dragana; Filipovic-Ljeshovic, Ivana; Pilcevic, Dijana

    2008-01-01

    Immune response against Helicobacter pylori is important for the course and outcome of infection. We conducted study looking for the difference in anti H. pylori IgG and IgA between patients with intestinal type of gastric cancer, superficial and atrophic gastritis. For this study, 133 patients infected with H. pylori were enrolled: 50 with superficial gastritis, 42 with atrophic gastritis and 41 with gastric cancer. Anti H. pylori IgG and IgA ELISA tests were performed. The difference in antibody titers of IgG and IgA, frequency of IgA > IgG ratio and combination of low IgG and IgA > IgG ratio were analyzed. The patients with gastritis had higher titer of IgG that the patients with gastric cancer (p gastritis had higher titer of IgA than the patients with gastric cancer (p IgG ratio is more frequent in patients with gastric cancer than in the patients with superficial gastritis (p IgG is more frequent in the patients with gastric cancer than in the patients with gastritis (p cancer elicit different anti H. pylori IgG and IgA response than the patients with superficial and atrophic gastritis. Low IgG and IgA predominance seems characteristic for gastric cancer.

  17. Measles IgG antibody index correlates with T2 lesion load on MRI in patients with early multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Berit Rosche

    Full Text Available BACKGROUND: B cells and humoral immune responses play an important role in the pathogenesis and diagnosis of multiple sclerosis (MS. A characteristic finding in patients with MS is a polyspecific intrathecal B cell response against neurotropic viruses, specifically against measles virus, rubella virus, and varicella zoster virus, also known as an MRZ reaction (MRZR. Here, we correlated from the routine clinical diagnostics individual IgG antibody indices (AIs of MRZR with magnetic resonance imaging (MRI findings in patients with first MS diagnosis. METHODS/RESULTS: MRZR was determined in 68 patients with a clinically isolated syndrome (CIS or early relapsing-remitting MS (RRMS. Absolute AI values for measles virus, rubella virus, and varicella zoster virus were correlated with T2 lesion load and gadolinium enhancing lesions on cerebral MRI (cMRI and cMRI combined with spinal MRI (sMRI. Measles virus AI correlated significantly with T2 lesion load on cMRI (p = 0.0312, Mann-Whitney U test and the sum of lesions on cMRI and sMRI (p = 0.0413. Varicella zoster virus AI also showed a correlation with T2 lesion load on cMRI but did not reach statistical significance (p = 0.2893. CONCLUSION: The results confirm MRZR as part of the polyspecific immune reaction in MS with possible prognostic impact on MRI and clinical parameters. Furthermore, the data indicate that intrathecal measles virus IgG production correlates with disease activity on cMRI and sMRI in patients with early MS.

  18. Immunoglobulin E and G4 antibody responses in occupational airway exposure to bovine and porcine plasma proteins

    NARCIS (Netherlands)

    Krop, E. J. M.; Stapel, S. O.; de Vrieze, H.; van der Zee, J. S.

    2006-01-01

    BACKGROUND: Production of both antigen-specific immunoglobulin (Ig)E and IgG4 antibodies is dependent on stimulation of B cells by T helper 2 cell-derived cytokines. However, there is controversy as to their interaction. In this study, we investigated the interdependency of IgE and IgG4 antibody

  19. Antibodies to Lactobacilli and Bifidobacteria in young children with different propensity to develop islet autoimmunity.

    Science.gov (United States)

    Talja, Ija; Kubo, Anna-Liisa; Veijola, Riitta; Knip, Mikael; Simell, Olli; Ilonen, Jorma; Vähä-Mäkilä, Mari; Sepp, Epp; Mikelsaar, Marika; Utt, Meeme; Uibo, Raivo

    2014-01-01

    The intestinal microbiota is essential to the maturation and homeostasis of the immune system. Immunoblot assays were used to establish the prevalence of serum IgG, IgM, and IgA antibodies specific for Bifidobacterium adolescentis, Bifidobacterium longum, and Lactobacillus rhamnosus GG proteins in young children presenting with or without type 1 diabetes (T1D). We demonstrated that children between the ages of 6 and 12 months had a substantial increase in the frequency of IgG antibodies specific for L. rhamnosus GG proteins. We measured IgG, IgM, and IgA class antibody reactivity against B. adolescentis DSM 20083, B. adolescentis DSM 20086, and B. longum DSM 20088 proteins demonstrating significantly higher IgA responses against B. adolescentis DSM 20083 strain proteins in children who developed islet autoimmunity and T1D later in life. B. adolescentis strains showed more IgM type antibodies in children who developed T1D later in life, but the difference was not statistically significant. B. longum proteins were recognized by IgG and IgA antibodies to a higher extent compared to other bacteria studied. These results confirm that differences in immune reactivity against some commensal strains in young children may represent a different risk factor for developing T1D.

  20. Challenges in Developing a Biochip for Intact Histamine Using Commercial Antibodies

    Directory of Open Access Journals (Sweden)

    Leena Mattsson

    2017-12-01

    Full Text Available This study describes the development and the challenges in the development of an on-chip immunoassay for histamine using commercially available antibodies. Histamine can be used as an indicator of food freshness and quality, but it is also a relevant marker in clinical diagnostics. Due to its low molecular weight, simple structure and thus low immunogenicity production of high specificity and affinity antibodies is difficult. From six commercial anti-histamine antibodies tested, only two bound the histamine free in the solution. A fluorescent on-chip immunoassay for histamine was established with a dynamic range of 8–111 µg/mL using polyclonal anti-histamine antibody H7403 from Sigma (Mendota Heights, MN, USA. The anti-histamine antibodies described and used in published literature are thoroughly reviewed and the quality of commercial antibodies and their traceability and quality issues are highlighted and extensively discussed.

  1. Chemical modification of birch allergen extract leads to a reduction in allergenicity as well as immunogenicity.

    Science.gov (United States)

    Würtzen, Peter Adler; Lund, Lise; Lund, Gitte; Holm, Jens; Millner, Anders; Henmar, Helene

    2007-01-01

    In Europe, specific immunotherapy is currently conducted with vaccines containing allergen preparations based on intact extracts. In addition to this, chemically modified allergen extracts (allergoids) are used for specific allergy treatment. Reduced allergenicity and thereby reduced risk of side effects in combination with retained ability to activate T cells and induce protective allergen-specific antibody responses has been claimed for allergoids. In the current study, we compared intact allergen extracts and allergoids with respect to allergenicity and immunogenicity. The immunological response to birch allergen extract, alum-adsorbed extract, birch allergoid and alum-adsorbed allergoid was investigated in vitro in human basophil histamine release assay and by stimulation of human allergen-specific T cell lines. In vivo, Bet v 1-specific IgG titers in mice were determined after repetitive immunizations. In all patients tested (n = 8), allergoid stimulations led to reduced histamine release compared to the intact allergen extract. However, the allergoid preparations were not recognized by Bet v 1-specific T cell lines (n = 7), which responded strongly to the intact allergen extract. Mouse immunizations showed a clearly reduced IgG induction by allergoids and a strongly potentiating effect of the alum adjuvant. Optimal IgG titers were obtained after 3 immunizations with intact allergen extracts, while 5 immunizations were needed to obtain maximal response to the allergoid. The reduced histamine release observed for allergoid preparations may be at the expense of immunological efficacy because the chemical modifications lead to a clear reduction in T cell activation and the ability to induce allergen-specific IgG antibody responses. Copyright 2007 S. Karger AG, Basel.

  2. Expression of human FcgammaRIIIa as a GPI-linked molecule on CHO cells to enable measurement of human IgG binding.

    Science.gov (United States)

    Armour, Kathryn L; Smith, Cheryl S; Clark, Michael R

    2010-03-31

    The efficacy of a therapeutic IgG molecule may be as dependent on the optimisation of the constant region to suit its intended indication as on the selection of its variable regions. A crucial effector function to be maximised or minimised is antibody-dependent cell-mediated cytotoxicity by natural killer cells. Traditional assays of ADCC activity suffer from considerable inter-donor and intra-donor variability, which makes the measurement of antibody binding to human FcgammaRIIIa, the key receptor for ADCC, an attractive alternative method of assessment. Here, we describe the development of cell lines and assays for this purpose. The transmembrane receptor, FcgammaRIIIa, requires co-expression with signal transducing subunits to prevent its degradation, unlike the homologous receptor FcgammaRIIIb that is expressed as a GPI-anchored molecule. Therefore, to simplify the production of cell lines as reliable assay components, we expressed FcgammaRIIIa as a GPI-anchored molecule. Separate, stable CHO cell lines that express either the 158F or the higher-affinity 158V allotype of FcgammaRIIIa were isolated using fluorescence-activated cell sorting. The identities of the expressed receptors were confirmed using a panel of monoclonal antibodies that distinguish between subclasses and allotypes of FcgammaRIII and the cell lines were shown to have slightly higher levels of receptor than FcgammaRIII-positive peripheral blood mononuclear cells. Because the affinity of FcgammaRIIIa for IgG is intermediate amongst the receptors that bind IgG, we were able to use these cell lines to develop flow cytometric assays to measure the binding of both complexed and monomeric immunoglobulin. Thus, by choosing the appropriate method, weakly- or strongly-binding IgG can be efficiently compared. We have quantified the difference in the binding of wildtype IgG1 and IgG3 molecules to the two functional allotypes of the receptor and report that the FcgammaRIIIa-158V-antibody interaction is 3

  3. Prevalência de anticorpos IgG antiparvovírus B19 em gestantes durante o atendimento pré-natal e casos de hidropisia fetal não imune atribuídos ao parvovírus B19, na Cidade do Rio de Janeiro Anti-parvovirus B19 IgG antibody prevalence in pregnant women during antenatal follow-up and cases of non-immune hydropsis fetalis due to parvovirus B19, in the City of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    André Ricardo Araujo da Silva

    2006-10-01

    Full Text Available Com o objetivo de medir a prevalência de anticorpos IgG contra o parvovírus B19 em gestantes com até 24 semanas de idade gestacional e detectar a ocorrência de casos de hidropisia fetal não-imune atribuídos a esse vírus, coletamos 249 amostras de soro em uma maternidade de referência na cidade do Rio de Janeiro, entre junho de 2003 e março de 2005. As gestantes foram acompanhadas até o termo da gestação, sendo detectados 17 casos de hidropisia fetal. Quatro casos foram atribuídos ao parvovírus B19 e dois destes ocorreram em gestantes residentes na zona oeste da cidade, em fevereiro de 2005. Resultados positivos para anticorpos IgG antiparvovírus B19 foram encontrados em 172 (71,6% gestantes (IC 95% 65,5-77,7%, sendo esta prevalência de anticorpos comparável à encontrada em outras cidades brasileiras. A única variável associada com aquisição prévia de anticorpos IgG foi número de gestações anteriores maior que um(p= 0,02, IC 95% 0,36-0,94.With the aim of measuring the prevalence of anti-parvovirus B19 IgG antibodies during pregnancy up to 24 weeks of gestation and detecting cases of nonimmune hydrops fetalis, 249 sera from pregnant women attending a reference hospital in Rio de Janeiro city, from June 2003 to November 2004 were collected. They were followed-up until the end of pregnancy, with 17 cases of fetal hydrops detected. Four cases were caused by parvovirus B19 and two of them occurred in pregnant women living in the western zone of the city, during February 2005. Anti-parvovirus B19 IgG antibodies were found in 172 (71.6% pregnant women (CI 95% 65.5%-77.7%; this antibody prevalence is similar to results found for others Brazilian cities. The only variable associated with previous acquisition of IgG antibodies to parvovirus B19 was number of pregnancies greater than one (p= 0.02, CI 95% 0.36-0.94.

  4. The prevalence of toxoplasma igG and IgM in pregnant women residing in Rawalpindi

    International Nuclear Information System (INIS)

    Kausar, N.; Akhtar, S.; Ikram, A.

    2010-01-01

    Objective: To determine the prevalence of Toxoplasma gondii antibodies (IgG/IgM) among pregnant women visiting Military Hospital Rawalpindi and to develop a relationship between various risk factors and disease prevalence. Methods: One thousand pregnant women reporting in out patient Gynaecology department of Military Hospital (MH) Rawalpindi from October 2008 through January 2009 for antenatal check up were included in the study. Their serum samples were tested for the presence of Toxoplasma IgM and IgG immunoglobulins. Enzyme Linked immunosorbent assay test kits for both IgG and IgM were used to detect 1: gondii immunoglobulins in serum samples. Rest of the serum was stored at -20 degree C. Results: Of the 1000 women sampled at hospital, 46 (4.6%) had evidence of past infection and were seropositive for immunoglobulins of T. gondii IgG, while none of them were seropositive for IgM immunoglobulin, suggesting absence of recent infections during pregnancy. Conclusion: In twin cities of Islamabad and Rawalpindi, the sero prevalence of T. gondii IgG in pregnant women is relatively high (4.6%) as compared to other areas nearby. Consequently, the risk of, primary infection during pregnancy and the potential for congenital infection of foetus remains there as a large number of pregnant women were sero-negative for both the antibodies.

  5. Performance of the multitarget Mikrogen Chlamydia trachomatis IgG ELISA in the prediction of tubal factor infertility (TFI) in subfertile women : Comparison with the Medac MOMP IgG ELISA plus

    NARCIS (Netherlands)

    van Ess, Eleanne F.; Ouburg, Sander; Spaargaren, Joke; Land, Jolande A.; Morre, Servaas A.

    2017-01-01

    There is a need for more accurate Chlamydia trachomatis (CT) IgG antibody tests for tubal factor infertility (TFI) diagnostics. We evaluated the predictive value for TFI of Medac ELISA plus (MOMP) and multitarget Mikrogen ELISA (MOMP-CPAF-TARP). Based on Medac ELISA plus results, 183 subfertile

  6. Preparation and characterization of chimeric CD19 monoclonal antibody

    International Nuclear Information System (INIS)

    Zola, H.; Macardle, P.J.; Bradford, T.; Weedon, H.; Yasui, H.; Kurosawa, Y.

    1991-01-01

    CD19 antibodies have been suggested as candidates for immunological attack on leukemic and lymphoma cells of the B lineage because the antigen is restricted to the B lineage. With the potential use of FMC63 in immunotherapy in mind a mouse-human chimera was produced in which the genes coding for the VDJ region of the heavy chain and the VJ region of the light chain derive from the FMC63 mouse hybridoma, while the C region genes code for human IgG1. The genes have been transfected back into a mouse myeloma line, which secretes low levels of immunoglobulin. (Ig). This Ig was purified and biotinylated in order to determine the specificity of the antibody. The chimeric antibody has a reaction profile concordant with the original FMC63 antibody, but has the properties of a human IgG1, including the ability to fix human complement. However, the antibody is not cytotoxic in vitro in the presence of complement or cells capable of mediating antibody-dependent cellular cytotoxicity. Possible reasons for this and ways of using the antibody are discussed. 47 refs., 7 figs

  7. Systemic and Mucosal Antibody Responses to Soluble and Nanoparticle-Conjugated Antigens Administered Intranasally

    Directory of Open Access Journals (Sweden)

    Savannah E. Howe

    2016-10-01

    Full Text Available Nanoparticles (NPs are increasingly being used for drug delivery, as well as antigen carriers and immunostimulants for the purpose of developing vaccines. In this work, we examined how intranasal (i.n. priming followed by i.n. or subcutaneous (s.c. boosting immunization affects the humoral immune response to chicken ovalbumin (Ova and Ova conjugated to 20 nm NPs (NP-Ova. We show that i.n. priming with 20 mg of soluble Ova, a dose known to trigger oral tolerance when administered via gastric gavage, induced substantial systemic IgG1 and IgG2c, as well as mucosal antibodies. These responses were further boosted following a s.c. immunization with Ova and complete Freund’s adjuvant (Ova+CFA. In contrast, 100 µg of Ova delivered via NPs induced an IgG1-dominated systemic response, and primed the intestinal mucosa for secretion of IgA. Following a secondary s.c. or i.n. immunization with Ova+CFA or NP-Ova, systemic IgG1 titers significantly increased, and serum IgG2c and intestinal antibodies were induced in mice primed nasally with NP-Ova. Only Ova- and NP-Ova-primed mice that were s.c.-boosted exhibited substantial systemic and mucosal titers for up to 6 months after priming, whereas the antibodies of i.n.-boosted mice declined over time. Our results indicate that although the amount of Ova delivered by NPs was 1000-fold less than Ova delivered in soluble form, the antigen-specific antibody responses, both systemic and mucosal, are essentially identical by 6 months following the initial priming immunization. Additionally, both i.n.- and s.c.-boosting strategies for NP-Ova-primed mice were capable of inducing a polarized Th1/Th2 immune response, as well as intestinal antibodies; however, it is only by using a heterogeneous prime-boost strategy that long-lasting antibody responses were initiated. These results provide valuable insight for future mucosal vaccine development, as well as furthering our understanding of mucosal antibody responses.

  8. Prevalence of IgG varicella zoster virus antibodies in the Kuikuro and Kaiabi indigenous communities in Xingu National Park, Brazil, before varicella vaccination Prevalência de anticorpos IgG contra o vírus varicela zoster nas aldeias indígenas Kuikuro e Kaiabi do Parque Nacional do Xingu, Brasil, antes da vacinação contra varicela

    Directory of Open Access Journals (Sweden)

    Manuel Mindlin Lafer

    2005-06-01

    Full Text Available The purpose of the study was to estimate the prevalence of IgG antibodies against varicella zoster virus (VZV in the two most populated indigenous ethnic groups from Xingu Indigenous National Park, in Brazil, prior to the introduction of vaccination against the disease, and to determine the positive and the negative predictive values of a history of varicella infection. In 2001, 589 inhabitants of two Kuikuro villages and three Kaiabi villages were evaluated and provided information concerning previous varicella infection. An indirect immunosorbent assay (ELISA to detect IgG anti-VZV antibodies was performed in 224 blood samples - volunteer selection had no interference of anamnesis. IgG prevalence was 80.8% (95% Confidence Interval: 76% - 86%. The seroepidemiology of varicella in Xingu National Park prior to varicella vaccine introduction was comparable to the Brazilian national seroprevalence described in the literature, and so were the positive (98% and the negative predictive value (41% of the referred history.O objetivo do estudo foi aferir a prevalência de anticorpos IgG contra o Vírus Varicela-Zoster (VVZ nos dois grupos étnicos indígenas mais povoados do Parque Nacional Indígena do Xingu, Brasil, antes da introdução da vacinação contra a doença, e determinar os valores preditivos positivo e negativo da história de infecção de varicela. Em 2001, 589 habitantes de duas aldeias Kuikuro e três aldeias Kaiabi foram avaliados e forneceram dados referentes à infecção prévia por varicela. Um ensaio imunoenzimático indireto (ELISA foi realizado em 224 amostras de sangue para detectar anticorpos IgG anti-VVZ - a seleção de voluntários não teve interferência da anamnese. A prevalência de IgG foi de 80,8% (Intervalo de Confiança de 95%: 76% - 86%. A soroepidemiologia de varicela no Parque Nacional do Xingu antes da introdução da vacina foi comparável à soroprevalência nacional descrita na literatura, assim como os

  9. Preparación de un conjugado peroxidasa-anti IgG humana (cadena en conejo Preparation of a peroxidase-anti human IgG conjugate (chain g in rabbit

    Directory of Open Access Journals (Sweden)

    Julio C Merlín Linares

    2001-08-01

    Full Text Available Se preparó un conjugado con peroxidasa a partir de los anticuerpos específicos aislados de un suero de conejo anti cadenas g de la IgG humana. Los anticuerpos específicos se aislaron por cromatografía de afinidad, y el conjugado se preparó por el método de oxidación con peryodato. El conjugado obtenido presentó una relación molar IgG/peroxidasa de 1,07, un valor de RZ de 0,33 y resultó evaluado satisfactoriamente en cuanto a su especificidad y reactividad en los ensayos inmunoenzimáticos realizadosA peroxidase conjugate was prepared starting from the specific antibodies isolated from an anti-chain rabbit serum and from human IgG. The specific antibodies were isolated by affinity chromatography and the conjugate was prepared by the method of oxidation with periodate. The conjugate obtained presented a molar IgG/peroxidase relation of 1.07, a RZ value of 0.33 and it was satisfactorily evaluated as regards its specificity and reactivity in the immunoenzimatic assays carried out

  10. Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus.

    Science.gov (United States)

    Karau, Melissa J; Tilahun, Mulualem E; Krogman, Ashton; Osborne, Barbara A; Goldsby, Richard A; David, Chella S; Mandrekar, Jayawant N; Patel, Robin; Rajagopalan, Govindarajan

    2017-10-03

    Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.

  11. Felix Hoppe-Seyler Lecture 1997. Protective antibody responses against viruses.

    Science.gov (United States)

    Zinkernagel, R M

    1997-08-01

    Neutralizing antibody responses against the acute cytopathic vesicular stomatitis virus (VSV) have been studied in mice to evaluate their general characteristics including specificity, self-/non-self discrimination and memory. IgM responses are generated very early, by day 3 to 4, in a T helper cell-independent fashion and without VSV having polyclonal activating capacities. The order of the glycoprotein tips on the virus envelope (multiple, 8-10 nm distance, paracrystalline) exhibiting the neutralizing determinants are key to this prompt response. These paracrystalline identical multimeric antigens are characteristic of infectious agents and are always reacted against by B cells. Self-antigens that are accessible to B cells in the intact host are either monomeric in serum or mobile multimers on cell surfaces; these configurations need contact dependent or contact independent T help, respectively. Because T help is tolerant against self-antigens, no anti-self B cell responses are usually induced against monomeric self-antigens. If collagen or DNA (rigid multimeric self-antigens) become accessible, however, they may become targets of auto-antibody responses. The antibody repertoire against VSV is partially contained in the germline and partially is generated by somatic mutation; they seem not to undergo affinity-maturation. In any case protection against lethal infection is dependent upon strictly T helper cell dependent IgG generated by day 6 to 7 and reaches a protective level of about 1-10 micrograms/ml. Interesting affinity/avidity and onrate above a minimal threshold are of no apparent advantage for protection in vivo. Maintenance of these antibody levels by antigen depots, and not the presence of memory B cells alone, is key to providing protective immunological memory. Collectively these data suggest that studying biologically important protective antibody responses may modify some of the parameters that have been defined by studying hapten specific antibody

  12. Quantitative and temporal analyses of murine antibody response in serum and gut secretions to infection with Giardia muris.

    Science.gov (United States)

    Snider, D P; Underdown, B J

    1986-04-01

    We analyzed the appearance and level of Giardia muris-specific antibody of immunoglobulin A (IgA), IgG, and IgM isotypes, at weekly intervals, over the course of a 7-week infection in BALB/c and C57BL/6 mice. Using sensitive immunoradiometric assays, we observed that IgA antibody was the only detectable anti-G. muris antibody in intestinal secretions throughout the course of infection. No secreted IgG or IgM anti-G. muris antibody was detected even in concentrated intestinal secretions. The expulsion of G. muris by the mice was associated closely with the appearance and increasing levels of secreted anti-G. muris IgA antibody. Both IgG and IgA serum antibody to G. muris were detected, but no serum IgM antibody was detected. Serum IgA and IgG anti-G. muris antibody remained at high levels up to 10 weeks following clearance of the parasite. An interesting observation indicated that serum IgA antibody to G. muris developed more slowly in response to infection than secreted IgA antibody. An analysis of the molecular weight distribution of total serum IgA in infected mice determined that infection produced a transient but significant shift in serum IgA to high-molecular-weight (greater than or equal to dimeric IgA) forms. The results indicate that a substantial IgA antibody response occurs in sera and in gut secretions of G. muris-resistant mice and that IgA antibody is the dominant and possibly the only effector antibody active in intestinal secretions during G. muris infection in mice.

  13. The immunological properties of haptens coupled to thymus-independent carrier molecules. IV. The IgG response to dinitrophenylated Ficoll.

    Science.gov (United States)

    Klaus, G G; Phillips, J M; Humphrey, J H; Dresser, D W; Cross, A M

    1976-06-01

    Dinitrophenylated polysucrose (DNP-Ficoll) elicits T cell-independent IgM anti-DNP antibody formation in mice. This antigen also elicits a heterogeneous IgG1 and IgG2 anti-DNP response, which is operationally as T-independent as the IgM response. However, a concomitant graft-versus-host reaction markedly enhances the IgG response (allogeneic effect). These results confirm those of others, indicating that a certain proportion of the precursors of IgG-producing cells can be triggered by some T-independent antigens. However, our results suggest that even with such antigens optimal triggering of IgG precursors requires T cell help.

  14. Direct electrical control of IgG conformation and functional activity at surfaces

    Science.gov (United States)

    Ghisellini, Paola; Caiazzo, Marialuisa; Alessandrini, Andrea; Eggenhöffner, Roberto; Vassalli, Massimo; Facci, Paolo

    2016-11-01

    We have devised a supramolecular edifice involving His-tagged protein A and antibodies to yield surface immobilized, uniformly oriented, IgG-type, antibody layers with Fab fragments exposed off an electrode surface. We demonstrate here that we can affect the conformation of IgGs, likely pushing/pulling electrostatically Fab fragments towards/from the electrode surface. A potential difference between electrode and solution acts on IgGs’ charged aminoacids modulating the accessibility of the specific recognition regions of Fab fragments by antigens in solution. Consequently, antibody-antigen affinity is affected by the sign of the applied potential: a positive potential enables an effective capture of antigens; a negative one pulls the fragments towards the electrode, where steric hindrance caused by neighboring molecules largely hampers the capture of antigens. Different experimental techniques (electrochemical quartz crystal microbalance, electrochemical impedance spectroscopy, fluorescence confocal microscopy and electrochemical atomic force spectroscopy) were used to evaluate binding kinetics, surface coverage, effect of the applied electric field on IgGs, and role of charged residues on the phenomenon described. These findings expand the concept of electrical control of biological reactions and can be used to gate electrically specific recognition reactions with impact in biosensors, bioactuators, smart biodevices, nanomedicine, and fundamental studies related to chemical reaction kinetics.

  15. Cutoff Values of Serum IgG4 and Histopathological IgG4+ Plasma Cells for Diagnosis of Patients with IgG4-Related Disease

    Directory of Open Access Journals (Sweden)

    Yasufumi Masaki

    2012-01-01

    Full Text Available IgG4-related disease is a new disease classification established in Japan in the 21st century. Patients with IgG4-related disease display hyper-IgG4-gammaglobulinemia, massive infiltration of IgG4+ plasma cells into tissue, and good response to glucocorticoids. Since IgG4 overexpression is also observed in other disorders, it is necessary to diagnose IgG4-related disease carefully and correctly. We therefore sought to determine cutoff values for serum IgG4 and IgG4/IgG and for IgG4+/IgG+ plasma cells in tissue diagnostic of IgG4-related disease. Patients and Methods. We retrospectively analyzed serum IgG4 concentrations and IgG4/IgG ratio and IgG4+/IgG+ plasma cell ratio in tissues of 132 patients with IgG4-related disease and 48 patients with other disorders. Result. Serum IgG4 >135  mg/dl demonstrated a sensitivity of 97.0% and a specificity of 79.6% in diagnosing IgG4-related disease, and serum IgG4/IgG ratios >8% had a sensitivity and specificity of 95.5% and 87.5%, respectively. IgG4+cell/IgG+ cell ratio in tissues >40% had a sensitivity and specificity of 94.4% and 85.7%, respectively. However, the number of IgG4+ cells was reduced in severely fibrotic parts of tissues. Conclusion. Although a recent unanimous consensus of all relevant researchers in Japan recently established the diagnostic criteria for IgG4-related disease, findings such as ours indicate that further discussion is needed.

  16. “Inclonals”: IgGs and IgG-enzyme fusion proteins produced in an E. coli expression-refolding system

    OpenAIRE

    Hakim, Rahely; Benhar, Itai

    2009-01-01

    Full-length antibodies and antibodies that ferry a cargo to target cells are desired biopharmaceuticals. We describe the production of full-length IgGs and IgG-toxin fusion proteins in E. coli. In the presented examples of anti CD30 and anti EGF-receptor antibodies, the antibody heavy and light chains or toxin fusions thereof were expressed in separate bacterial cultures, where they accumulated as insoluble inclusion bodies. Following refolding and purification, high yields (up to 50 mg/L of ...

  17. Characterization of isotypes of antibody response against leishmania parasite

    International Nuclear Information System (INIS)

    Elassad, Asma M.S.; Ghalib, Hashim W.; Younis, Saddia A.

    1994-01-01

    In this study an enzyme linked immunosorbent assay (ELIZA) was developed to detect IgG,IgM and IgA response in visceral leishmaniasis patients (VL) against L.donovain and L. major antigens compared to control groups; cutaneous leishmaniasis patients (CL), mucosal leishmaniasis patients (ML), patients with other tropical diseases and healthy controls.Highly specific IgG were found in VL patients with test specificity (93.7%) and sensitivity(93.4%). A moderate IgG were found in VL patients but non-specific while no IgA were detected in all studied groups. Also VL patients showed high specificity and sensitivity (95.2 and 96.6% respectively) against L.major antigen.The distribution of IgG subclasses (IgG1,IgG2,IgG3 and IgG4) antibodies in VL patients were assayed.IgG3 showed the highest specificity and sensitivity and titers followed by IgG1.Also the diagnostic value of ELIZA test for different leishmaniasis forms were discussed. (Author)

  18. Multiplex assay (Mikrogen recomBead) for detection of serum IgG and IgM antibodies to 13 recombinant antigens of Borrelia burgdorferi sensu lato in patients with neuroborreliosis

    DEFF Research Database (Denmark)

    Dessau, Ram Benny; Møller, Jens K.; Kolmos, Birte

    2015-01-01

    A multiplex-bead-based assay for the detection of serum antibodies to Borrelia burgdorferi sensu lato was evaluated. The assay contained 13 different antigens in both the IgG and the IgM assay; thus, a total of 26 measurement results were available from each sample. A total of 49 Danish patients......, the construction of a diagnostic score, evaluation of the scoring method using an independent dataset and an assessment of the analytical quality of the multiplex assay. The VlsE IgG had the highest diagnostic value with an AUC (area under the curve) of 96% on the receiver operating characteristic curve. The Osp......C IgM had AUCs just above 80%. All the other antigens had both low quantitative reactivity and lower contrast in the patients with LNB compared to controls. The diagnostic value of the assay may be improved by using a logistic model giving a sensitivity of 90 and 79% for the specificities at 92 and 98...

  19. Label Free QCM Immunobiosensor for AFB1 Detection Using Monoclonal IgA Antibody as Recognition Element

    Directory of Open Access Journals (Sweden)

    Özlem Ertekin

    2016-08-01

    Full Text Available This study introduces the use of an IgA isotype aflatoxin (AF specific monoclonal antibody for the development of a highly sensitive Quartz Crystal Microbalance (QCM immunobiosensor for the detection of AF in inhibitory immunoassay format. The higher molecular weight of IgA antibodies proved an advantage over commonly used IgG antibodies in label free immunobiosensor measurements. IgA and IgG antibodies with similar affinity for AF were used in the comparative studies. Sensor surface was prepared by covalent immobilization of AFB1, using self assembled monolayer (SAM formed on gold coated Quartz Crystal, with 1-Ethyl-3-(3-dimethylaminopropyl carbodiimide/N-hydroxy succinimide (EDC/NHS method using a diamine linker. Nonspecific binding to the surface was decreased by minimizing the duration of EDC/NHS activation. Sensor surface was chemically blocked after AF immobilization without any need for protein blocking. This protein free sensor chip endured harsh solutions with strong ionic detergent at high pH, which is required for the regeneration of the high affinity antibody-antigen interaction. According to the obtained results, the detection range with IgA antibodies was higher than IgG antibodies in QCM immunosensor developed for AFB1.

  20. Human IgG4 binds to IgG4 and conformationally altered IgG1 via Fc-Fc interactions

    NARCIS (Netherlands)

    Rispens, Theo; Ooievaar-de Heer, Pleuni; Vermeulen, Ellen; Schuurman, Janine; van der Neut Kolfschoten, Marijn; Aalberse, Rob C.

    2009-01-01

    The Fc fragment of IgG4 can interact with the Fc fragment of another IgG molecule. This interaction is a confounding factor when measuring IgG4 rheumatoid factor levels. Recently, we demonstrated that half-molecules of IgG4 can exchange to form a bispecific Ab. We expected these two phenomena to be

  1. Labelling of TTHA coupled IgG and MCAb with rare earth radionuclides

    International Nuclear Information System (INIS)

    Wu Younghui; Zhang Yulei; Wu Chuanchu; Wang Xiangyun; Liu Yuanfang

    1988-07-01

    This article expands a process of labelling G-immunoglobulin (IgG) and monoclonal antibody (MCAb) with rare earth radionuclides. In this labelling process, cycloanhydride (CTTHAA) of Tri-ethyl Tetra-amine Hexa-acetic Acid (TTHA) is employed as a bifunctional chelating conjugate, the metal chelation takes place after CTTHAA has first been linked to IgG, followed by chemical reaction with rare earth radionuclides. Detailed investigations have been carried out to examine the influencing parameters of labelling globulins with rare earth, such as metal to CTTHAA mole-ratio, pH value and labelling time. The immunoreactivity of the labelled compound (RE-TTHA-IgG) has been retained throughout the whole labelling process

  2. Comparing domain interactions within antibody Fabs with kappa and lambda light chains.

    Science.gov (United States)

    Toughiri, Raheleh; Wu, Xiufeng; Ruiz, Diana; Huang, Flora; Crissman, John W; Dickey, Mark; Froning, Karen; Conner, Elaine M; Cujec, Thomas P; Demarest, Stephen J

    2016-10-01

    IgG antibodies are multi-domain proteins with complex inter-domain interactions. Human IgG heavy chains (HCs) associate with light chains (LCs) of the κ or λ isotype to form mature antibodies capable of binding antigen. The HC/LC interaction involves 4 domains: VH and CH1 from the HC and VL and CL from the LC. Human Fabs with κ LCs have been well characterized for their unfolding behaviors and demonstrate a significant level of cooperativity and stabilization when all 4 domains are intact. Very little is known regarding the thermodynamic properties of human Fabs with λ LCs. Here, we dissect the domain contributions to Fab stability for both κ and λ LC-containing Fabs. We find the cooperativity of unfolding between the constant domains, CH1/Cλ, and variable domains, VH/Vλ, within λ LC-containing Fabs is significantly weaker than that of κ LC-containing Fabs. The data suggests there may not be an evolutionary necessity for strong variable/constant domain cooperativity within λ LC-containing Fabs. After investigating the biophysical properties of Fabs with mismatched variable and constant domain subunits (e.g., VH/Vκ paired with CH1/Cλ or T cell receptor Cα/Cβ), the major role of the constant domains for both κ- and λ-containing Fabs may be to reduce the hydrophobic exposure at the VH/VL interface. Even though Fabs with these non-native pairings were thermodynamically less stable, they secreted well from mammalian cells as well behaved monodisperse proteins, which was in contrast to what was observed with the VH/Vκ and VH/Vλ scFvs that secreted as a mixture of monomer and aggregates.

  3. Relationship between exposure to vector bites and antibody responses to mosquito salivary gland extracts.

    Science.gov (United States)

    Fontaine, Albin; Pascual, Aurélie; Orlandi-Pradines, Eve; Diouf, Ibrahima; Remoué, Franck; Pagès, Frédéric; Fusaï, Thierry; Rogier, Christophe; Almeras, Lionel

    2011-01-01

    Mosquito-borne diseases are major health problems worldwide. Serological responses to mosquito saliva proteins may be useful in estimating individual exposure to bites from mosquitoes transmitting these diseases. However, the relationships between the levels of these IgG responses and mosquito density as well as IgG response specificity at the genus and/or species level need to be clarified prior to develop new immunological markers to assess human/vector contact. To this end, a kinetic study of antibody levels against several mosquito salivary gland extracts from southeastern French individuals living in three areas with distinct ecological environments and, by implication, distinct Aedes caspius mosquito densities were compared using ELISA. A positive association was observed between the average levels of IgG responses against Ae. caspius salivary gland extracts and spatial Ae. caspius densities. Additionally, the average level of IgG responses increased significantly during the peak exposure to Ae. caspius at each site and returned to baseline four months later, suggesting short-lived IgG responses. The species-specificity of IgG antibody responses was determined by testing antibody responses to salivary gland extracts from Cx. pipiens, a mosquito that is present at these three sites at different density levels, and from two other Aedes species not present in the study area (Ae. aegypti and Ae. albopictus). The IgG responses observed against these mosquito salivary gland extracts contrasted with those observed against Ae. caspius salivary gland extracts, supporting the existence of species-specific serological responses. By considering different populations and densities of mosquitoes linked to environmental factors, this study shows, for the first time, that specific IgG antibody responses against Ae. caspius salivary gland extracts may be related to the seasonal and geographical variations in Ae. caspius density. Characterisation of such immunological

  4. Comparison of the chemical behaviour of humanized ACMS VS. Human IGG radiolabeled with 99mTc

    International Nuclear Information System (INIS)

    Rivero Santamaria, Alejandro; Zayas Crespo, Francisco; Mesa Duennas, Niurka; Castillo Vitloch, Adolfo J.

    2003-01-01

    The purpose of this work is to compare the chemical behaviour of humanized AcMs vs. human IgG radiolabeled with 99 mTc. to this end, 3 immunoglobulins were analyzed, the IgG (human), the humanized monoclonal antibody R3 (Acm-R3h) and the humanized monoclonal antibody T1. The results obtained reveal slight differences as regards the behaviour of theses immunoglobulins before the labelling with 99T c, which shows differences in the chemical behaviour of these proteins. Although in theory the modifications that are made to the AcMs in order to humanize them must not affect their chemical behaviour, the obtained data indicate that the conditions for their radiolabelling should not be extrapolated from other proteins; on the contrary, particular procedures should be elaborated for each AcM-h

  5. Rabbit IgG directed to a synthetic C-terminal peptide of the major grass pollen allergen Lol p I inhibits human basophil histamine release induced by natural Lol p I.

    Science.gov (United States)

    van Ree, R; Aalberse, R C

    1995-03-01

    The potential role of allergen-specific IgG antibodies as 'blocking' antibodies in allergen-induced human basophil histamine release was investigated. This was studied in a model with the major grass pollen allergen Lol p I and polyclonal rabbit antisera directed against this allergen and against a synthetic peptide of its C terminus. When allergen and antibodies were allowed to preincubate, Lol p I induced histamine release was inhibited up to 85% by the antiserum against Lol p I. By omitting preincubation, and thereby more closely mimicking an in vivo situation, up to 55% inhibition was realized. This indicates that allergen-specific IgG can act as 'blocking' antibody without preincubation. Immunization of rabbits with a synthetic C-terminal peptide of Lol p I resulted in antibodies reactive with natural Lol p I. Despite their 100-fold lower avidity for Lol p I (as compared with antinatural Lol p I), these antibodies had the capacity to inhibit Lol p I induced histamine release for > 90% (up to 50% without preincubation). This indicates that it is possible to block histamine release induced by a major allergen with low-avidity IgG antibodies directed against a minor proportion of the allergen (25 amino acids). IgE antibodies from the donors studied were unreactive with this synthetic peptide, indicating that for blocking activity identical epitope specificity of IgE and IgG is not essential. This opens interesting perspectives for application of synthetic peptides in immunotherapy, distinct from their effects on T cell reactivity.

  6. Human monoclonal antibodies reactive with human myelomonocytic leukemia cells.

    Science.gov (United States)

    Posner, M R; Santos, D J; Elboim, H S; Tumber, M B; Frackelton, A R

    1989-04-01

    Peripheral blood mononuclear cells from a patient with chronic myelogenous leukemia (CML), in remission, were depleted of CD8-positive T-cells and cultured with Epstein-Barr virus. Four of 20 cultures (20%) secreted human IgG antibodies selectively reactive with the cell surfaces of certain human leukemia cell lines. Three polyclonal, Epstein-Barr virus-transformed, B-cell lines were expanded and fused with the human-mouse myeloma analogue HMMA2.11TG/O. Antibody from secreting clones HL 1.2 (IgG1), HL 2.1 (IgG3), and HL 3.1 (IgG1) have been characterized. All three react with HL-60 (promyelocytic), RWLeu4 (CML promyelocytic), and U937 (monocytic), but not with KG-1 (myeloblastic) or K562 (CML erythroid). There is no reactivity with T-cell lines, Burkitt's cell lines, pre-B-leukemia cell lines, or an undifferentiated CML cell line, BV173. Leukemic cells from two of seven patients with acute myelogenous leukemia and one of five with acute lymphocytic leukemia react with all three antibodies. Normal lymphocytes, monocytes, polymorphonuclear cells, red blood cells, bone marrow cells, and platelets do not react. Samples from patients with other diverse hematopoietic malignancies showed no reactivity. Immunoprecipitations suggest that the reactive antigen(s) is a lactoperoxidase iodinatable series of cell surface proteins with molecular weights of 42,000-54,000 and a noniodinatable protein with a molecular weight of 82,000. Based on these data these human monoclonal antibodies appear to react with myelomonocytic leukemic cells and may detect a leukemia-specific antigen or a highly restricted differentiation antigen.

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

    Directory of Open Access Journals (Sweden)

    Galván Ramírez María de la Luz

    1999-01-01

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

  8. A quantitative ELISA procedure for the measurement of membrane-bound platelet-associated IgG (PAIgG).

    Science.gov (United States)

    Lynch, D M; Lynch, J M; Howe, S E

    1985-03-01

    A quantitative ELISA assay for the measurement of in vivo bound platelet-associated IgG (PAIgG) using intact patient platelets is presented. The assay requires quantitation and standardization of the number of platelets bound to microtiter plate wells and an absorbance curve using quantitated IgG standards. Platelet-bound IgG was measured using an F(ab')2 peroxidase labeled anti-human IgG and o-phenylenediamine dihydrochloride (OPD) as the substrate. Using this assay, PAIgG for normal individuals was 2.8 +/- 1.6 fg/platelet (mean +/- 1 SD; n = 30). Increased levels were found in 28 of 30 patients with clinical autoimmune thrombocytopenia (ATP) with a range of 7.0-80 fg/platelet. Normal PAIgG levels were found in 26 of 30 patients with nonimmune thrombocytopenia. In the sample population studied, the PAIgG assay showed a sensitivity of 93%, specificity of 90%, a positive predictive value of 0.90, and a negative predictive value of 0.93. The procedure is highly reproducible (CV = 6.8%) and useful in evaluating patients with suspected immune mediated thrombocytopenia.

  9. Local oral immunization with synthetic peptides induces a dual mucosal IgG and salivary IgA antibody response and prevents colonization of Streptococcus mutans.

    Science.gov (United States)

    Lehner, T; Haron, J; Bergmeier, L A; Mehlert, A; Beard, R; Dodd, M; Mielnik, B; Moore, S

    1989-01-01

    A small cell surface antigen of Streptococcus mutans was partially sequenced and the amino terminal peptides of 11, 15 and 20 amino acid residues and a dimer of the 15 and 20 residues peptides were synthesized. The synthetic peptides (SP) were used in topical oral immunization of the gingivomucosal epithelium of macaque monkeys. Sequential examination for antibodies over a period of up to 30 weeks revealed that six applications of the linear or cyclized SP11 and a random SP11 induced negligible or very low antibody levels. In contrast, the SP17 (SP15 with added cysteine at each terminus), SP21 (SP20 with one cysteine) and the dimer (SP35) induced significant anti-SP as well as anti-native streptococcal antibodies in the gingival fluid and in saliva. The functional significance of this immune response was examined by studying its effect on oral colonization of S. mutans following feeding of a carbohydrate-rich diet. Whereas control animals, sham-immunized with a random SP of 11 residues, showed increased colonization of the teeth by S. mutans, there was no colonization or a significant reduction in colonization of animals immunized with the cyclized SP17, linear SP21 or dimerized SP35. These experiments suggest that local immunization with SP derived from the sequences of a streptococcal cell surface antigen induce a dual local immune response of gingival IgG and salivary IgA antibodies against the SP and native SA. These antibodies may be involved in preventing colonization of S. mutans, which is the principal agent in the development of dental caries. PMID:2759661

  10. [Analysis of epitopes and function of anti-M3 muscarinic acetylcholine receptor antibodies in patients with Sjögren's syndrome].

    Science.gov (United States)

    Tsuboi, Hiroto; Matsuo, Naomi; Iizuka, Mana; Nakamura, Yumi; Matsumoto, Isao; Sumida, Takayuki

    2010-01-01

    Sjögren's syndrome (SS) is an autoimmune disease that affects exocrine glands including salivary and lacrimal glands. It is characterized by lymphocytic infiltration into exocrine glands, leading to dry mouth and eyes. A number of auto-antibodies, such as anti-SS-A and SS-B antibodies, are detected in patients with SS. However, no SS-specific pathologic auto-antibodies have yet been found in this condition. M3 muscarinic acetylcholine receptor (M3R) plays a crucial role in the secretion of saliva from salivary glands. It is reported that some patients with SS carried inhibitory auto-antibodies against M3R. To clarify the epitopes and function of anti-M3R antibodies in SS, we examined antibodies to the extracellular domains (N terminal region, the first, second, and third extracellular loop) of M3R by ELISA using synthesized peptide antigens encoding these domains in 42 SS and 42 healthy controls (HC). Titers and positivity of anti-M3R antibodies to every extracellular domain of M3R were significantly higher in SS than in HC. For functional analysis, human salivary gland (HSG) cells were pre-cultured with IgG from anti-M3R antibodies positive SS, negative SS, and HC. HSG cells were stimulated with cevimeline hydrochloride and intracellular calcium concentration ([Ca(2+)](i)) was measured. IgG from anti-M3R antibodies to the second loop positive SS inhibited the increase of [Ca(2+)](i), but IgG from antibodies to the N terminal or the first loop positive SS enhanced it, while IgG from antibodies to the third loop positive SS showed no effect on [Ca(2+)](i) as well as IgG from anti-M3R antibodies negative SS and HC. These findings indicated the presence of several B cell epitopes on M3R in SS and effect of anti-M3R antibodies on the salivary secretion might differ with these epitopes.

  11. Anti-Toxoplasma gondii antibodies in patients with beta-hemoglobinopathies: the first report in the Americas.

    Science.gov (United States)

    Ferreira, Marina Neves; Bonini-Domingos, Claudia Regina; Fonseca Estevão, Isabeth; de Castro Lobo, Clarice Lopes; Souza Carrocini, Gisele Cristina; Silveira-Carvalho, Aparecida Perpétuo; Ricci, Octávio; de Mattos, Luiz Carlos; Brandão de Mattos, Cinara Cássia

    2017-06-14

    In Brazil, there have been no previous studies of Toxoplasma gondii infection in sickle cell anemia patients and carriers of severe forms of beta-thalassemia. This study evaluated T. gondii infection in patients with beta-hemoglobinopathies. A total of 158 samples, 77 (48.7%) men and 81 (51.3%) women, were evaluated. Three groups were formed: G1 (85 patients with sickle cell disease); G2 (11 patients with homozygous beta-thalassemia; G3 (62 patients with heterozygous beta-thalassemia). ELISA was employed to identify anti-T. gondii IgM and IgG antibodies, and molecular analysis was performed to determine beta-hemoglobin mutations. Fisher's exact test was used to compare frequencies of anti-T. gondii IgM and IgG antibodies in respect to gender and age. Anti-T. gondii IgG antibodies were found in 43.5% of individuals in G1, 18.1% in G2 and 50% in G3. All samples from G1 and G2 were seronegative for anti-T. gondii IgM antibodies, but 3.2% from G3 were seropositive. Considering anti-T. gondii IgG antibodies, no statistical significant differences were found between these groups nor in seroprevalence between genders within each group. Despite this, comparisons of the mean ages between G1, G2 and G3 were statistically significant (G2 vs. G1: p value = 0.0001; G3 vs. G1: p-value <0.0001; G3 vs. G2: p-value = 0.0001). A comparison by age of patients with sickle cell anemia showed a trend of lower risk of infection among younger individuals. Therefore, this study demonstrates that T. gondii infection occurs in patients with beta-thalassemia and sickle cell anemia in Brazil as seen by the presence of anti-T. gondii IgM and IgG antibodies.

  12. Avian IgY antibodies: characteristics and applications in immunodiagnostic

    Directory of Open Access Journals (Sweden)

    Lívia Silveira Munhoz

    2014-01-01

    Full Text Available Immunoglobulin Y (IgY is the major antibody isotype in birds, reptiles, amphibia, and lungfish, playing a similar biological role as mammal IgG. Due to its phylogenetic distance, immune diversification and presence in the egg yolk, IgY provide a number of advantages in immunodiagnostic compared to IgG from mammals. Moreover, IgY production is in agreement with international efforts to reduce, refine and if possible, to replace animals in experimentation, contributing substantially in favor of animal welfare. This article presents an overview about structural and functional features, production and applications of IgY in immunodiagnostic, as well as the advantages of chicken antibodies use.

  13. Human IgG Antibody Response to Aedes Nterm-34kDa Salivary Peptide, an Epidemiological Tool to Assess Vector Control in Chikungunya and Dengue Transmission Area.

    Science.gov (United States)

    Elanga Ndille, Emmanuel; Doucoure, Souleymane; Poinsignon, Anne; Mouchet, François; Cornelie, Sylvie; D'Ortenzio, Eric; DeHecq, Jean Sébastien; Remoue, Franck

    2016-12-01

    Arboviral diseases are an important public health concerns. Vector control remains the sole strategy to fight against these diseases. Because of the important limits of methods currently used to assess human exposure to Aedes mosquito bites, much effort is being devoted to develop new indicators. Recent studies have reported that human antibody (Ab) responses to Aedes aegypti Nterm-34kDa salivary peptide represent a promising biomarker tool to evaluate the human-Aedes contact. The present study aims investigate whether such biomarker could be used for assessing the efficacy of vector control against Aedes. Specific human IgG response to the Nterm-34kDa peptide was assessed from 102 individuals living in urban area of Saint-Denis at La Reunion Island, Indian Ocean, before and after the implementation of vector control against Aedes mosquitoes. IgG response decreased after 2 weeks (P Aedes mosquito density, as estimated by entomological parameters and closely correlated to vector control implementation and was not associated with the use of individual protection, daily commuting outside of the house, sex and age. Our findings indicate a probable short-term decrease of human exposure to Aedes bites just after vector control implementation. Results provided in the present study indicate that IgG Ab response to Aedes aegypti Nterm-34kDa salivary peptide could be a relevant short-time indicator for evaluating the efficacy of vector control interventions against Aedes species.

  14. In vitro Fab display: a cell-free system for IgG discovery

    Science.gov (United States)

    Stafford, Ryan L.; Matsumoto, Marissa L.; Yin, Gang; Cai, Qi; Fung, Juan Jose; Stephenson, Heather; Gill, Avinash; You, Monica; Lin, Shwu-Hwa; Wang, Willie D.; Masikat, Mary Rose; Li, Xiaofan; Penta, Kalyani; Steiner, Alex R.; Baliga, Ramesh; Murray, Christopher J.; Thanos, Christopher D.; Hallam, Trevor J.; Sato, Aaron K.

    2014-01-01

    Selection technologies such as ribosome display enable the rapid discovery of novel antibody fragments entirely in vitro. It has been assumed that the open nature of the cell-free reactions used in these technologies limits selections to single-chain protein fragments. We present a simple approach for the selection of multi-chain proteins, such as antibody Fab fragments, using ribosome display. Specifically, we show that a two-chain trastuzumab (Herceptin) Fab domain can be displayed in a format which tethers either the heavy or light chain to the ribosome while retaining functional antigen binding. Then, we constructed synthetic Fab HC and LC libraries and performed test selections against carcinoembryonic antigen (CEA) and vascular endothelial growth factor (VEGF). The Fab selection output was reformatted into full-length immunoglobulin Gs (IgGs) and directly expressed at high levels in an optimized cell-free system for immediate screening, purification and characterization. Several novel IgGs were identified using this cell-free platform that bind to purified CEA, CEA positive cells and VEGF. PMID:24586053

  15. Anti-Glycoprotein G Antibodies of Herpes Simplex Virus 2 Contribute to Complete Protection after Vaccination in Mice and Induce Antibody-Dependent Cellular Cytotoxicity and Complement-Mediated Cytolysis

    Directory of Open Access Journals (Sweden)

    Staffan Görander

    2014-11-01

    Full Text Available We investigated the role of antibodies against the mature portion of glycoprotein G (mgG-2 of herpes simplex virus 2 (HSV-2 in protective immunity after vaccination. Mice were immunized intramuscularly with mgG-2 and oligodeoxynucleotides containing two CpG motifs plus alum as adjuvant. All C57BL/6 mice survived and presented no genital or systemic disease. High levels of immunoglobulin G subclass 1 (IgG1 and IgG2 antibodies were detected and re-stimulated splenic CD4+ T cells proliferated and produced IFN-γ. None of the sera from immunized mice exhibited neutralization, while all sera exerted antibody-dependent cellular cytotoxicity (ADCC and complement-mediated cytolysis (ACMC activity. Passive transfer of anti-mgG-2 monoclonal antibodies, or immune serum, to naive C57BL/6 mice did not limit disease progression. Immunized B‑cell KO mice presented lower survival rate and higher vaginal viral titers, as compared with vaccinated B-cell KO mice after passive transfer of immune serum and vaccinated C57BL/6 mice. Sera from mice that were vaccinated subcutaneously and intranasally with mgG-2 presented significantly lower titers of IgG antibodies and lower ADCC and ACMC activity. We conclude that anti-mgG-2 antibodies were of importance to limit genital HSV‑2 infection. ADCC and ACMC activity are potentially important mechanisms in protective immunity, and could tentatively be evaluated in future animal vaccine studies and in clinical trials.

  16. Detection of anti neutrophil antibodies by radio-iodinated protein A binding test

    International Nuclear Information System (INIS)

    Cartron, J.; Muller, J.Y.; Tchernia, G.; Paule, B.; Varet, B.

    1983-01-01

    The granulocyte associated IgG in normal and neutropenic subjects has been determined by a direct quantitative assay using radiolabeled staphylococcal protein A. This assay allows to postulate an immunological mechanism to explain the neutropenia in 19 cases of neutropenias associated with malfunctions of the immune system and in 4 cases of idiopathic neutropenias. Discussed in this report is the possible interaction of immune complexes bound in vivo to the granulocytes. By an immunofluorescence test, it has been possible to detect IgG or IgM antibodies in only 52% of patients with a positive direct assay. The determination of granulocyte-associated IgG is therefore a better indicator for defining an auto-immune neutropenia than the detection of free antibodies in the sera [fr

  17. Parvovirus B19 antibodies and correlates of infection in pregnant women attending an antenatal clinic in central Nigeria

    Directory of Open Access Journals (Sweden)

    Samuel E Emiasegen

    2011-03-01

    Full Text Available Human parvovirus B19 infection is associated with spontaneous abortion, hydrops foetalis, intrauterine foetal death, erythema infectiosum (5th disease, aplastic crisis and acute symmetric polyarthropathy. However, data concerning Nigerian patients with B19 infection have not been published yet. The purpose of this study was to establish the prevalence of B19 IgG and IgM antibodies, including correlates of infection, among pregnant women attending an antenatal clinic in Nigeria. Subsequent to clearance from an ethical committee, blood samples were collected between August-November 2008 from 273 pregnant women between the ages of 15-40 years who have given their informed consent and completed self-administered questionnaires. Recombinant IgG and IgM enzyme linked immunosorbent assay kits (Demeditec Diagnostics, Germany were used for the assays. Out of the 273 participants, 111 (40.7% had either IgG or IgM antibodies. Out of these, 75 (27.5% had IgG antibodies whereas 36 (13.2% had IgM antibodies, and those aged 36-40 years had the highest prevalence of IgG antibodies. Significant determinants of infection (p < 0.05 included the receipt of a blood transfusion, occupation and the presence of a large number of children in the household. Our findings have important implications for transfusion and foeto-maternal health policy in Nigeria. Routine screening for B19 IgM antibodies and accompanying clinical management of positive cases should be made mandatory for all Nigerian blood donors and women of childbearing age.

  18. Association between serum antibodies to periodontal bacteria and rheumatoid factor in NHANES III

    Science.gov (United States)

    Goh, Charlene E.; Kopp, Jacob; Papapanou, Panos N.; Molitor, Jerry A.; Demmer, Ryan T.

    2016-01-01

    Objective Alterations in the microbiome, including the periodontal microbiome, may be a risk factor for rheumatoid arthritis (RA). Most studies that have analyzed this association are relatively small, focus primarily on a single periodontal pathogen (Porphyromonas gingivalis), and are not population-based. We investigated the association between elevated serum IgG antibodies to 19 periodontal species and the prevalence of rheumatoid factor (RF) in a large nationally representative sample of adults. Methods The Third National Health and Nutrition Examination Survey is a cross-sectional sample of the non-institutionalized US population (n=33,994). Our study population included all dentate participants ≥60 years, who did not have RA as defined by a modified version of the American College of Rheumatology 1987 criteria, and had complete data for both serum IgG antibodies against periodontal bacteria and serum RF antibody titer (n=2461). Results Adjusted odds ratios (ORs) (95% CI) summarizing the relationship between the 19 periodontal serum IgGs and RF seropositivity ranged from 0.53 (0.29, 0.97) to 1.27 (0.79, 2.06), and 17 of the 19 observed ORs were periodontal IgGs to be mostly unassociated with RF seropositivity in the nationally representative NHANES III. Elevated antibody levels to P. intermedia and C. ochracea were associated with lower odds of RF seropositivity. PMID:27110949

  19. Glycation, oxidation and glycoxidation of IgG: a biophysical, biochemical, immunological and hematological study.

    Science.gov (United States)

    Islam, Sidra; Moinuddin; Mir, Abdul Rouf; Raghav, Alok; Habib, Safia; Alam, Khursheed; Ali, Asif

    2017-09-12

    Glycation and oxidation induce structural alterations in the proteins in an interdependent manner with consequent pathological implications. The published literature presents wide range of modifications in conformational characteristics of proteins by glycation and oxidation; however, there is little data that could elaborate the cumulative effect of both the processes. This study has analysed the modifications in IgG by methylglyoxal (MG) (glycative stress), hydroxyl radical ([Formula: see text]) (oxidative stress) and by their combined action i.e. [Formula: see text] treatment of MG glycated IgG (glycoxidation). It further addresses the implications of the altered structural integrity of IgG on its immunological characteristics and impact on haematological parameters in rabbits. Using circular dichroism, FTIR, SDS-PAGE analysis, thioflavin-T fluorescence assay, congo red absorbance analysis, dynamic light scattering, transmission electron microscopy, ELISA, blood cell counts and rectal temperature studies, we report that the glycoxidative modification caused maximum alteration in the IgG as compared to the glycatively and oxidatively modified protein. Far-UV CD results confirmed the highest decline in the beta-pleated sheet content of the protein by glycoxidation. The damage led to the reduced flexibility and enhanced electronic interactions in IgG as observed by near-UV CD. Modifications caused cross-linking and adduct formation in the serum protein. The electron micrograph confirmed amorphous aggregation in modified IgG. The modifications increased the hydrodynamic radius of IgG by allowing the attachment of [Formula: see text] and MG residues. The glycoxidatively modified IgG induced the maximum antibody titres that showed high specificity towards the altered IgG. The glycoxidation of IgG leads to activation of inflammatory pathways.

  20. A Unique Report: Development of Super Anti-Human IgG Monoclone with Optical Density Over Than 3

    Directory of Open Access Journals (Sweden)

    Leili Aghebati Maleki

    2013-08-01

    Full Text Available Purpose: Monoclonal antibodies and related conjugates are key reagents used in biomedical researches as well as, in treatment, purification and diagnosis of infectious and non- infectious diseases. Methods: Balb/c mice were immunized with purified human IgG. Spleen cells of the most immune mouse were fused with SP2/0 in the presence of Poly Ethylene Glycol (PEG. Supernatant of hybridoma cells was screened for detection of antibody by ELISA. Then, the sample was assessed for cross-reactivity with IgM & IgA by ELISA and confirmed by immunoblotting. The subclasses of the selected mAbs were determined. The best clone was injected intraperitoneally to some pristane-injected mice. Anti-IgG mAb was purified from the animals' ascitic fluid by Ion exchange chromatography and then, mAb was conjugated with HRP. Results: In the present study, over than 50 clones were obtained that 1 clone had optical density over than 3. We named this clone as supermonoclone which was selected for limiting dilution. The result of the immunoblotting, showed sharp band in IgG position and did not show any band in IgM&IgA position. Conclusion: Based on the findings of this study, the conjugated monoclonal antibody could have application in diagnosis of infectious diseases like Toxoplasmosis, Rubella and IgG class of other infectious and non- infectious diseases.