Regulation of IgE antibody production by serum molecules. I. Serum from complete Freund's adjuvant-immune donors suppresses irradiation-enhanced IgE production in low responder mouse strains

International Nuclear Information System (INIS)

Tung, A.S.; Chiorazzi, N.; Katz, D.H.

1978-01-01

Exposure of mice to low doses of x irradiation at or near the time of primary immunization with 2,4-dinitrophenyl (DNP)-Ascaris suum extract (ASC) results in substantial enhancement of IgE anti-DNP antibody responses; the IgG antibody responses of such mice do not increase after such manipulations. This selective enhancement of IgE antibody production occurs in mice of both high and low IgE responder phenotype, although the extent of enhancement compared to unmanipulated control animals is more striking in low IgE responder mice. The studies presented here demonstrate that the irradiation-enhanced IgE antibody responses of low responder SJL and C57BL/6 mice as well as of intermediate responder AKR mice can be effectively suppressed by passive transfer of CFA-immune serum obtained from isologous donor mice. Moreover, adoptive secondary IgE antibody responses in SJL recipients of primed syngeneic spleen cells can be totally abolished by passive transfer of CFA-immune serum or ascitic fluid from CFA-immune mice. The suppressive activity of CFA-immune serum can be diminished or eliminated by exposure of CFA-primed donor mice to low dose x irradiation at an appropriate point during the priming regimen, after a single inoculation of CFA, and before collection of serum. Low dose x irradiation was not effective in eliminating suppressive activity of CFA-induced ascites fluid obtained from donor mice inoculated repeatedly with CFA. In contrast to the capacity of CFA-immune serum from isologous donors to suppress irradiation-enhanced IgE responses of low responder mice, similar sera or ascites fluids were ineffective in suppressing irradiation-enhanced responses of high responder BALB/c or (SJL x BALB/c)F 1 hybrid mice

Tus-Ter-lock immuno-PCR assays for the sensitive detection of tropomyosin-specific IgE antibodies.

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Johnston, Elecia B; Kamath, Sandip D; Lopata, Andreas L; Schaeffer, Patrick M

2014-02-01

The increasing prevalence of food allergies requires development of specific and sensitive tests capable of identifying the allergen responsible for the disease. The development of serologic tests that can detect specific IgE antibodies to allergenic proteins would, therefore, be highly received. Here we present two new quantitative immuno-PCR assays for the sensitive detection of antibodies specific to the shrimp allergen tropomyosin. Both assays are based on the self-assembling Tus-Ter-lock protein-DNA conjugation system. Significantly elevated levels of tropomyosin-specific IgE were detected in sera from patients allergic to shrimp. This is the first time an allergenic protein has been fused with Tus to enable specific IgE antibody detection in human sera by quantitative immuno-PCR.

Structural basis of omalizumab therapy and omalizumab-mediated IgE exchange

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Pennington, Luke F.; Tarchevskaya, Svetlana; Brigger, Daniel; Sathiyamoorthy, Karthik; Graham, Michelle T.; Nadeau, Kari Christine; Eggel, Alexander; Jardetzky, Theodore S.

2016-01-01

Omalizumab is a widely used therapeutic anti-IgE antibody. Here we report the crystal structure of the omalizumab–Fab in complex with an IgE-Fc fragment. This structure reveals the mechanism of omalizumab-mediated inhibition of IgE interactions with both high- and low-affinity IgE receptors, and explains why omalizumab selectively binds free IgE. The structure of the complex also provides mechanistic insight into a class of disruptive IgE inhibitors that accelerate the dissociation of the high-affinity IgE receptor from IgE. We use this structural data to generate a mutant IgE-Fc fragment that is resistant to omalizumab binding. Treatment with this omalizumab-resistant IgE-Fc fragment, in combination with omalizumab, promotes the exchange of cell-bound full-length IgE with omalizumab-resistant IgE-Fc fragments on human basophils. This combination treatment also blocks basophil activation more efficiently than either agent alone, providing a novel approach to probe regulatory mechanisms underlying IgE hypersensitivity with implications for therapeutic interventions. PMID:27194387

The property distance index PD predicts peptides that cross-react with IgE antibodies

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Ivanciuc, Ovidiu; Midoro-Horiuti, Terumi; Schein, Catherine H.; Xie, Liping; Hillman, Gilbert R.; Goldblum, Randall M.; Braun, Werner

2009-01-01

Similarities in the sequence and structure of allergens can explain clinically observed cross-reactivities. Distinguishing sequences that bind IgE in patient sera can be used to identify potentially allergenic protein sequences and aid in the design of hypo-allergenic proteins. The property distance index PD, incorporated in our Structural Database of Allergenic Proteins (SDAP, http://fermi.utmb.edu/SDAP/), may identify potentially cross-reactive segments of proteins, based on their similarity to known IgE epitopes. We sought to obtain experimental validation of the PD index as a quantitative predictor of IgE cross-reactivity, by designing peptide variants with predetermined PD scores relative to three linear IgE epitopes of Jun a 1, the dominant allergen from mountain cedar pollen. For each of the three epitopes, 60 peptides were designed with increasing PD values (decreasing physicochemical similarity) to the starting sequence. The peptides synthesized on a derivatized cellulose membrane were probed with sera from patients who were allergic to Jun a 1, and the experimental data were interpreted with a PD classification method. Peptides with low PD values relative to a given epitope were more likely to bind IgE from the sera than were those with PD values larger than 6. Control sequences, with PD values between 18 and 20 to all the three epitopes, did not bind patient IgE, thus validating our procedure for identifying negative control peptides. The PD index is a statistically validated method to detect discrete regions of proteins that have a high probability of cross-reacting with IgE from allergic patients. PMID:18950868

Immunization with Hypoallergens of shrimp allergen tropomyosin inhibits shrimp tropomyosin specific IgE reactivity.

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Christine Y Y Wai

Full Text Available Designer proteins deprived of its IgE-binding reactivity are being sought as a regimen for allergen-specific immunotherapy. Although shrimp tropomyosin (Met e 1 has long been identified as the major shellfish allergen, no immunotherapy is currently available. In this study, we aim at identifying the Met e 1 IgE epitopes for construction of hypoallergens and to determine the IgE inhibitory capacity of the hypoallergens. IgE-binding epitopes were defined by three online computational models, ELISA and dot-blot using sera from shrimp allergy patients. Based on the epitope data, two hypoallergenic derivatives were constructed by site-directed mutagenesis (MEM49 and epitope deletion (MED171. Nine regions on Met e 1 were defined as the major IgE-binding epitopes. Both hypoallergens MEM49 and MED171 showed marked reduction in their in vitro reactivity towards IgE from shrimp allergy patients and Met e 1-sensitized mice, as well as considerable decrease in induction of mast cell degranulation as demonstrated in passive cutaneous anaphylaxis assay. Both hypoallergens were able to induce Met e 1-recognizing IgG antibodies in mice, specifically IgG2a antibodies, that strongly inhibited IgE from shrimp allergy subjects and Met e 1-sensitized mice from binding to Met e 1. These results indicate that the two designer hypoallergenic molecules MEM49 and MED171 exhibit desirable preclinical characteristics, including marked reduction in IgE reactivity and allergenicity, as well as ability to induce blocking IgG antibodies. This approach therefore offers promises for development of immunotherapeutic regimen for shrimp tropomyosin allergy.

Differential IgE binding to isoallergens from Asian seabass (Lates calcarifer) in children and adults.

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Sharp, Michael F; Kamath, Sandip D; Koeberl, Martina; Jerry, Dean R; O'Hehir, Robyn E; Campbell, Dianne E; Lopata, Andreas L

2014-11-01

Fish allergy is a common food allergy, with prevalence rates in the general population ranging between 0.2% and 2.3%. In both adults and children fish ranks in the top eight foods known to cause IgE mediated food allergy. Fish allergy is rarely outgrown and individuals with fish allergy may be allergic to some but not all species of fish. Whilst fish allergy occurs around the world, the characterization of allergenic components of individual species of fish has been largely confined to Northern hemisphere and European fish species. To date allergy to commonly consumed fish in the Asian-Pacific region including barramundi (Asian seabass; Lates calcarifer) have been less well investigated. The aim of this study was to identify and characterize allergenic proteins from barramundi in both fish allergic adult and pediatric patients. Serum from 17 fish allergic adults and children from Australia were characterized by immunoblotting and enzyme linked immunosorbent assays (ELISA) against raw and heated barramundi. Molecular analysis of identified allergens included genetic sequencing and generation of recombinant isoallergens. Two novel parvalbumin isoforms of the β-type were identified as the only allergens in barramundi and subsequently designated as Lat c 1.0101 and Lat c 1.0201 by the International Union of Immunological Societies. These two isoallergens do not differ in their ability to bind IgE antibodies, but are differentially expressed in barramundi tissue. This study characterized two novel heat stable parvalbumin allergens from barramundi, with differential IgE binding capacity between adults and pediatric patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Specific IgE antibodies to vespids in the course of immunotherapy with Vespula germanica administered to patients sensitized to Polistes dominulus.

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Juarez, C; Blanca, M; Miranda, A; Sanchez, F; Carmona, M J; Avila, M J; Fernandez, S; Fernandez, J; Terrados, S

1992-08-01

Sera from a group of 12 patients with anaphylactic reactions to vespids were studied. Field observations and RAST values suggested that the offending insect was Polistes dominulus (PD). Specific IgE antibodies to PD appeared in all cases and to Vespula germanica (VG) in nine. Absorption studies in these basal sera showed that IgE antibodies to VG were due to cross-reactivity with PD. The RAST value to both venoms was higher after immunotherapy (IT) in six cases. IgE antibodies increased to determinants common to both vespids, and in 41% of the cases to specific epitopes of VG venom allergens not initially detected in the basal sera. In one case antibodies increased only to VG without a corresponding rise to PD. These results indicate that if the correct venom to which the individuals are sensitized is not administered IgE antibodies may appear which were not initially detected in the patients' sera. The levels of these antibodies declined during the course of IT.

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

Rapid polyclonal desensitization with antibodies to IgE and FcεRIα.

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Khodoun, Marat V; Kucuk, Zeynep Yesim; Strait, Richard T; Krishnamurthy, Durga; Janek, Kevin; Lewkowich, Ian; Morris, Suzanne C; Finkelman, Fred D

2013-06-01

Rapid desensitization, a procedure in which persons allergic to an antigen are treated at short intervals with increasing doses of that antigen until they tolerate a large dose, is an effective, but risky, way to induce temporary tolerance. We wanted to determine whether this approach can be adapted to suppress all IgE-mediated allergies in mice by injecting serially increasing doses of monoclonal antibodies (mAbs) to IgE or FcεRIα. Active and passive models of antigen- and anti-IgE mAb-induced IgE-mediated anaphylaxis were used. Mice were desensitized with serially increasing doses of anti-IgE mAb, anti-FcεRIα mAb, or antigen. Development of shock (hypothermia), histamine and mast cell protease release, cytokine secretion, calcium flux, and changes in cell number and FcεRI and IgE expression were evaluated. Rapid desensitization with anti-IgE mAb suppressed IgE-mediated immediate hypersensitivity; however, some mice developed mild anaphylaxis during desensitization. Rapid desensitization with anti-FcεRIα mAb that only binds FcεRI that is not occupied by IgE suppressed both active and passive IgE-mediated anaphylaxis without inducing disease. It quickly, but temporarily, suppressed IgE-mediated anaphylaxis by decreasing mast cell signaling through FcεRI, then slowly induced longer lasting mast cell unresponsiveness by removing membrane FcεRI. Rapid desensitization with anti-FcεRIα mAb was safer and longer lasting than rapid desensitization with antigen. A rapid desensitization approach with anti-FcεRIα mAb safely desensitizes mice to IgE-mediated anaphylaxis by inducing mast cell anergy and later removing all mast cell IgE. Rapid desensitization with an anti-human FcεRIα mAb may be able to prevent human IgE-mediated anaphylaxis. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Analysis of calcium-induced conformational changes in calcium-binding allergens and quantitative determination of their IgE binding properties.

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Parody, Nuria; Fuertes, Miguel Angel; Alonso, Carlos; Pico de Coaña, Yago

2013-01-01

The polcalcin family is one of the most epidemiologically relevant families of calcium-binding allergens. Polcalcins are potent plant allergens that contain one or several EF-hand motifs and their allergenicity is primarily associated with the Ca(2+)-bound form of the protein. Conformation, stability, as well as IgE recognition of calcium-binding allergens greatly depend on the presence of protein-bound calcium ions. We describe a protocol that uses three techniques (SDS-PAGE, circular dichroism spectroscopy, and ELISA) to describe the effects that calcium has on the structural changes in an allergen and its IgE binding properties.

IgE and allergen-specific immunotherapy-induced IgG4 recognize similar epitopes of Bet v 1, the major allergen of birch pollen.

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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.

Measurement of IgE antibodies against purified grass pollen allergens (Lol p 1, 2, 3 and 5) during immunotherapy

NARCIS (Netherlands)

van Ree, R.; van Leeuwen, W. A.; Dieges, P. H.; van Wijk, R. G.; de Jong, N.; Brewczyski, P. Z.; Kroon, A. M.; Schilte, P. P.; Tan, K. Y.; Simon-Licht, I. F.; Roberts, A. M.; Stapel, S. O.; Aalberse, R. C.

1997-01-01

BACKGROUND: IgE titres tend to rise early after the start of immunotherapy, followed by a decline to pre-immunotherapy levels or lower. OBJECTIVES: We were interested to know whether the early increase in IgE antibodies includes new specificities of IgE, and whether these responses persist. METHODS:

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

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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.

98 Specific IGE and IGG Binding to Allergoids of Phleum pratense

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Cases, Barbara; Fernandez-Caldas, Enrique; Tudela, Jose Ignacio; Fernandez, Eva Abel; Sanchez-Garcia, Silvia; Ibañez, M. Dolores; Escudero, Carmelo; Casanovas, Miguel

2012-01-01

Background Allergoids were first used in the decades of the 60s and 70s of the last century as an effective treatment of allergic respiratory diseases. Allergoids can be modified with formaldehyde or glutaraldehyde. Modified allergens, or allergoids, decrease the risk of adverse reactions while administering higher allergen doses. The objective of this study was to analyse specific IgE and IgG binding to glutaraldehyde modified and non-modified allergen extracts of Phleum pratense. Methods The sera of 69 patients sensitized to P. pratense were tested. All these patients had signs and symptoms of rhinoconjunctivitis with, or without, asthma in May and June of 2011. All these patients had positive skin prick tests to a standardized extract of P. pratense, and other grass species. Most patients were also sensitized to olive pollen. Specific IgE and IgG binding were analysed by direct ELISA against P. pratense native (non-modified) and allergoid extracts. Relative potencies were evaluated through ELISA inhibition assays, and the protein composition of non-modified and allergoid samples was determined by Mass Spectrometry (MS/MS). Results Mean Specific IgE levels against the native extract was 16.68 ± 11.65 Units (U) and against the allergoid: 7.26 ± 8.24 U (P allergoid (P = 0.16; Mann-Whitney). Linear regression coefficients obtained between immunoglobulin reactivity against both extracts were: r2 = 0.51 for specific IgE and r2 = 0.83 for specific IgG. An important decrease in the allergenic activity, measured by inhibition ELISA, was clearly observed. The MS/MS assay revealed the presence of the mayor allergen, and some isoforms, in non-modified and allergoid extracts. Conclusions Results obtained demonstrate that the glutaraldehyde polymerization process induces an important decrease in specific IgE binding to allergoids of P. pratense while there are no significant differences in specific IgG binding. The allergenic composition of the P. pratense allergoid was

Serum IgE Antibodies against Hazelnut in Hazelnut Processing Workers

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Ege Gulec Balbay

2012-01-01

Full Text Available Aim. Previous studies have shown a higher sensitization rate to hazelnut in processing workers but no relation was found between the respiratory symptoms in workplace and hazelnut sensitization. Material and Method. To evaluate the association between the hazelnut sensitization and workplace-related respiratory complaints, hazelnut processing workers had undergone a questionnaire included work-related respiratory symptoms, smoking history, pulmonary function testing, and measurement of serum IgE antibodies against hazelnut. Results. This study consisted of 88 hazelnut processing workers (79 females and 9 males, aged 14–59 years (Mean ± SD: years. The mean working duration was months (min: 1–max: 180. Specific IgE against hazelnut allergens was positive in 14 of cases (17.1%. There was no significant difference between the cases with and without specific IgE against hazelnut allergens regarding respiratory symptoms, history of allergy, smoking status and spirometric values. Conclusion. 17.1% of the hazelnut processing workers were seropositive against hazelnut. Being sensitized to hazelnut was not found to be associated with work-related respiratory symptoms in this study. Further studies are needed in hazelnut workers respiratory health to search topics other than asthma.

IgE antibodies to Hymenoptera venoms in the serum are common in the general population and are related to indications of atopy.

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Schäfer, T; Przybilla, B

1996-06-01

Determination of Hymenoptera venom (HV)-specific serum IgE antibodies is a useful diagnostic method in patients with systemic anaphylactic reaction (SAR) to Hymenoptera stings. In a general population cohort, we determined the prevalence of SAR and HV-specific IgE antibodies and assessed parameters associated with the latter. A total of 277 voluntarily participating inhabitants of rural Bavaria (Germany) (232 adults, mean age 38.0 years; 45 children, mean age 8.4 years) were investigated for a history of atopic disease or SAR to insect stings; in 258 of these, total IgE and specific IgE antibodies to HV (Apis mellifera, Vespula vulgaris/germanica) and four common aeroallergens (birch pollen, grass pollen, house-dust mite, and cat dander) in the serum were determined. Nine (3.3%) subjects reported SAR to insect stings. In 27.1% of the sera, specific IgE antibodies to HV were found, to bee venom in 24.8%, and to wasp venom in 8.5% (P 100 kU/l was found in 22.5%. Specific serum IgE to HV was significantly associated with male sex (female vs. male, OR = 0.47; CI 0.25-0.86), young age (children vs. adults, OR = 2.80; CI 1.25-6.28), a history of SAR to insect stings (OR = 4.16; CI 1.15-15.03), total sIgE > 100 kU/l (OR = 3.88; CI 1.98-7.60), and specific IgE antibodies to three of the four aeroallergens (grass pollen, OR = 7.24 CI 3.66-14.38; birch pollen, OR = 3.67 CI 1.54-8.81; and house-dust mite, OR = 4.61 CI 2.08-10.32). It is concluded that immunologic sensitization to HV is common in the general population and is associated with atopy-related humoral IgE hyperresponsiveness.

Isoforms of the major peanut allergen Ara h 2: IgE binding in children with peanut allergy.

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Hales, Belinda J; Bosco, Anthony; Mills, Kristina L; Hazell, Lee A; Loh, Richard; Holt, Patrick G; Thomas, Wayne R

2004-10-01

The major peanut allergen Ara h 2 consists of two isoforms, namely Ara h 2.0101 and Ara h 2.0201. The recently identified Ara h 2.0201 isoform contains an extra 12 amino acids including an extra copy of the reported immunodominant epitope DPYSPS. This study aimed to evaluate the IgE binding of the two Ara h 2 isoforms. Ten clones of Ara h 2 were sequenced to assess the relative frequency of the Ara h 2 isoforms and to identify whether there was further variation in the Ara h 2 sequence. IgE binding to Ara h 2.0101 and Ara h 2.0201 was measured for 70 peanut-allergic children using an IgE DELFIA assay to quantitate specific IgE binding. A competition assay was used to measure whether Ara h 2.0201 contained IgE epitopes other than those found for Ara h 2.0101. The original Ara h 2.0101 sequence was found for 6/10 clones and Ara h 2.0201 was found for 2/10 clones. Ara h 2.0201 had the expected insertion of 12 amino acids as well as substitutions at positions 40 (40G) and 142 (142E). Two new isoforms were identified as different polymorphisms of position 142. One Ara h 2.01 clone (Ara h 2.0102) contained 142E and one Ara h 2.02 clone (Ara h 2.0202) contained 142D. A polymorphism that was previously identified by other investigators at position 77 (77Q or 77R) was not found for any of the 10 sequences. Although the level of IgE binding to Ara h 2.0201 of individual patients was frequently higher than the binding to Ara h 2.0101 (p originally sequenced Ara h 2.0101 isoform and contains other IgE specificities.

Screening for hen's egg and chicken meat specific IgE antibodies in ...

African Journals Online (AJOL)

Background: Allergy to hen's egg and meat contributes significantly to the manifestations of food allergy all over the world. Objectives: This study was performed to assess the presence of hen's egg and meat specific IgE antibodies among patients investigated for various allergic disorders. Methods. This is a retrospective ...

Screening for hen's egg and chicken meat specific IgE antibodies in ...

African Journals Online (AJOL)

Abstract. Background: Allergy to hen's egg and meat contributes significantly to the manifestations of food allergy all over the world. Objectives: This study was performed to assess the presence of hen's egg and meat specific IgE antibodies among patients investigated for various allergic disorders. Methods. This is a ...

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).

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)

Prevalence of IgE antibodies to grain and grain dust in grain elevator workers.

Science.gov (United States)

Lewis, D M; Romeo, P A; Olenchock, S A

1986-01-01

IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies. PMID:3709478

Prevalence of IgE antibodies to grain and grain dust in grain elevator workers

Energy Technology Data Exchange (ETDEWEB)

Lewis, D.M.; Romeo, P.A.; Olenchock, S.A.

1986-04-01

IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies.

Prevalence of IgE antibodies to grain and grain dust in grain elevator workers

International Nuclear Information System (INIS)

Lewis, D.M.; Romeo, P.A.; Olenchock, S.A.

1986-01-01

IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies

Staphylococcal superantigen-specific IgE antibodies: degree of sensitization and association with severity of asthma.

Science.gov (United States)

Elabras, José; Mello, Fernanda Carvalho de Queiroz; Lupi, Omar; Bica, Blanca Elena Rios Gomes; Papi, José Angelo de Souza; França, Alfeu Tavares

2016-01-01

To determine the presence of staphylococcal superantigen-specific IgE antibodies and degree of IgE-mediated sensitization, as well as whether or not those are associated with the severity of asthma in adult patients. This was a cross-sectional study involving outpatients with asthma under treatment at a tertiary care university hospital in the city of Rio de Janeiro, Brazil. Consecutive patients were divided into two groups according to the severity of asthma based on the Global Initiative for Asthma criteria: mild asthma (MA), comprising patients with mild intermittent or persistent asthma; and moderate or severe asthma (MSA). We determined the serum levels of staphylococcal toxin-specific IgE antibodies, comparing the results and performing a statistical analysis. The study included 142 patients: 72 in the MA group (median age = 46 years; 59 females) and 70 in the MSA group (median age = 56 years; 60 females). In the sample as a whole, 62 patients (43.7%) presented positive results for staphylococcal toxin-specific IgE antibodies: staphylococcal enterotoxin A (SEA), in 29 (20.4%); SEB, in 35 (24.6%); SEC, in 33 (23.2%); and toxic shock syndrome toxin (TSST), in 45 (31.7%). The mean serum levels of IgE antibodies to SEA, SEB, SEC, and TSST were 0.96 U/L, 1.09 U/L, 1.21 U/L, and 1.18 U/L, respectively. There were no statistically significant differences between the two groups in terms of the qualitative or quantitative results. Serum IgE antibodies to SEA, SEB, SEC, and TSST were detected in 43.7% of the patients in our sample. However, neither the qualitative nor quantitative results showed a statistically significant association with the clinical severity of asthma. Determinar a presença de anticorpos IgE específicos para superantígenos estafilocócicos e o grau de sensibilização mediada por esses, assim como se esses estão associados à gravidade da asma em pacientes adultos. Estudo transversal incluindo asmáticos adultos em acompanhamento ambulatorial em

Respiratory infections in adults with atopic disease and IgE antibodies to common aeroallergens.

Directory of Open Access Journals (Sweden)

Aino Rantala

Full Text Available BACKGROUND: Atopic diseases, including allergic rhinitis, allergic dermatitis and asthma, are common diseases with a prevalence of 30-40% worldwide and are thus of great global public health importance. Allergic inflammation may influence the immunity against infections, so atopic individuals could be susceptible to respiratory infections. No previous population-based study has addressed the relation between atopy and respiratory infections in adulthood. We assessed the relation between atopic disease, specific IgE antibodies and the occurrence of upper and lower respiratory infections in the past 12 months among working-aged adults. METHODS AND FINDINGS: A population-based cross-sectional study of 1008 atopic and non-atopic adults 21-63 years old was conducted. Information on atopic diseases, allergy tests and respiratory infections was collected by a questionnaire. Specific IgE antibodies to common aeroallergens were measured in serum. Adults with atopic disease had a significantly increased risk of lower respiratory tract infections (LRTI; including acute bronchitis and pneumonia with an adjusted risk ratio (RR 2.24 (95% confidence interval [CI] 1.43, 3.52 and upper respiratory tract infections (URTI; including common cold, sinusitis, tonsillitis, and otitis media with an adjusted RR 1.55 (1.14, 2.10. The risk of LRTIs increased with increasing level of specific IgE (linear trend P = 0.059. CONCLUSIONS: This study provides new evidence that working-aged adults with atopic disease experience significantly more LRTIs and URTIs than non-atopics. The occurrence of respiratory infections increased with increasing levels of specific IgE antibodies to common aeroallergens, showing a dose-response pattern with LRTIs. From the clinical point of view it is important to recognize that those with atopies are a risk group for respiratory infections, including more severe LRTIs.

Measurement of IgE antibodies against purified grass pollen allergens (Lol p 1, 2, 3 and 5) during immunotherapy.

Science.gov (United States)

Van Ree, R; Van Leeuwen, W A; Dieges, P H; Van Wijk, R G; De Jong, N; Brewczyski, P Z; Kroon, A M; Schilte, P P; Tan, K Y; Simon-Licht, I F; Roberts, A M; Stapel, S O; Aalberse, R C

1997-01-01

IgE titres tend to rise early after the start of immunotherapy, followed by a decline to pre-immunotherapy levels or lower. We were interested to know whether the early increase in IgE antibodies includes new specificities of IgE, and whether these responses persist. Sera of 64 patients undergoing grass pollen immunotherapy were tested for IgE against four purified grass pollen allergens: Lol p 1, 2, 3, and 5. At least two serum samples were taken, one before the start of therapy and one between 5 and 18 months after the first immunization (mean: 10 months). The mean IgE responses to Lol p 1, 2 and 3 showed a moderate but not significant increase. In contrast, the mean IgE response to Lol p 5 showed a significant decrease of > 30%. IgE against total Lohum perenne pollen extract moderately increased (> 20%), showing that a RAST for total pollen is not always indicative for the development of IgE against its major allergens. For > 40% of the patients it was found that IgE against one or more of the four allergens increased, while IgE against the remaining allergen(s) decreased. For 10 sera the ratio of IgE titres against at least two allergens changed by at least a factor of 5. The changes in specific IgE also included conversions from negative (< 0.1 RU) to positive (0.6 to 5.0 RU) for five patients. For two patients, the induction of these 'new' IgE antibodies against major allergens was shown to result in a response that was persistent over several years. Although active induction of new IgE specificities by immunotherapy was not really proven, the observations in this study indicate that monitoring of IgE against purified (major) allergens is necessary to evaluate changes in specific IgE in a reliable way.

Close-up of the alpha-1,3-Gal epitope as defined by a monoclonal chimeric IgE and human serum using saturation transfer difference (STD) NMR

DEFF Research Database (Denmark)

Plum, Melanie; Michel, Yvonne; Wallach, Katharina

2011-01-01

of an alpha-Gal-specific murine IgM antibody was employed to construct chimeric IgE and IgG antibodies. Reactivity and specificity of the resulting antibodies were assessed by means of ELISA and receptor binding studies. Using defined carbohydrates, interaction of the IgE and human serum was assessed...... by mediator release assays, surface plasmon resonance (SPR) and STD NMR analyses. The alpha-Gal-specific chimeric IgE and IgG antibodies were proven functional regarding interaction with antigen and Fc receptors. SPR measurements demonstrated affinities in the micromolar range. In contrast to a reference...

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

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

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

Science.gov (United States)

Hébert, J; Bernier, D; Mourad, W

1990-06-01

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

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...

Comparison between sensitivity of autologous skin serum test and autologous plasma skin test in patients with Chronic Idiopathic Urticaria for detection of antibody against IgE or IgE receptor (FcεRIα).

Science.gov (United States)

Sajedi, Vahid; Movahedi, Masoud; Aghamohammadi, Asghar; Aghamohamadi, Asghar; Gharagozlou, Mohammad; Ghareguzlou, Mohammad; Shafiei, Alireza; Soheili, Habib; Sanajian, Nahal

2011-06-01

Intradermal injection of autologous serum and plasma elicit a cutaneous reactivity in almost 45-60% of patients with Chronic Idiopathic Urticaria (CIU). This reactivity is associated with the presence of auto antibodies against IgE or IgE receptors. This study was carried out to compare the cutaneous reactivity of autologous serum and plasma skin tests in a series of patients with CIU for diagnosis of auto antibodies against IgE or IgE receptor. Fifty eight patients with CIU were injected intradermally with autologous serum and plasma (anticoagulated by citrate). Histamine was used as positive control and normal saline as negative control. The study group was checked by routine laboratory tests (CBC, U/A etc), allergens with skin prick tests, and serum IgE level, and auto antibodies against thyroid as well. Duration of urticaria was another factor which was assessed.There was no significant difference between positive ASST and positive APST patients for the above mentioned tests. 77.6% of the patients were Positive for APST and 65.5% were ASST positive. Duration of urticaria was longer in patients with positive ASST and APST than ASST and APST negative patients, although the difference was not statistically significant.Autologus serum skin test (ASST) and autologous plasma skin test (APST) could be used for estimation of duration and severity of urticaria and planning for the treatment.

Combined effect of glycation and sodium carbonate-bicarbonate buffer concentration on IgG binding, IgE binding and conformation of ovalbumin.

Science.gov (United States)

Ma, Xiao-juan; Gao, Jin-yan; Chen, Hong-bing

2013-10-01

Ovalbumin (OVA) is a major allergen in hen egg. During thermal processing, reducing sugars contained in the hen egg white might easily undergo glycation with OVA, but few studies have been conducted on its corresponding immunoreactivity changes. The aim of the present study was to assess changes of the antigenicity, potential allergenicity and conformation of OVA after glycation in a wet-thermal processing system under different concentrations of sodium carbonate-bicarbonate buffer. IgE binding of the glycated OVA was increased after glycation, and the higher the sodium carbonate-bicarbonate buffer concentration, the higher the IgE binding capacity. The increase in IgE binding of OVA corresponded well with the disruption of the disulfide bond, which exposed the epitopes initially buried. Antigenicity of the glycated OVA was increased, and the amount of the increase varied among samples treated under different buffer concentrations. Glycation increased the allergenic potential for OVA, with the amount of increase varying with different sodium carbonate-bicarbonate buffer concentrations. © 2013 Society of Chemical Industry.

Relationship between natural and heme-mediated antibody polyreactivity

Energy Technology Data Exchange (ETDEWEB)

Hadzhieva, Maya; Vassilev, Tchavdar [Stephan Angelov Institute of Microbiology, Bulgarian Academy of Sciences, Sofia 1113 (Bulgaria); Bayry, Jagadeesh; Kaveri, Srinivas; Lacroix-Desmazes, Sébastien [Sorbonne Universités, UPMC Univ Paris 06, UMR-S 1138, Centre de Recherche des Cordeliers, F-75006 Paris (France); INSERM, UMR-S 1138, F-75006 Paris (France); Université Paris Descartes, Sorbonne Paris Cité, UMR-S 1138, F-75006 Paris (France); Dimitrov, Jordan D., E-mail: jordan.dimitrov@crc.jussieu.fr [Sorbonne Universités, UPMC Univ Paris 06, UMR-S 1138, Centre de Recherche des Cordeliers, F-75006 Paris (France); INSERM, UMR-S 1138, F-75006 Paris (France); Université Paris Descartes, Sorbonne Paris Cité, UMR-S 1138, F-75006 Paris (France)

2016-03-25

Polyreactive antibodies represent a considerable fraction of the immune repertoires. Some antibodies acquire polyreactivity post-translationally after interaction with various redox-active substances, including heme. Recently we have demonstrated that heme binding to a naturally polyreactive antibody (SPE7) results in a considerable broadening of the repertoire of recognized antigens. A question remains whether the presence of certain level of natural polyreactivity of antibodies is a prerequisite for heme-induced further extension of antigen binding potential. Here we used a second monoclonal antibody (Hg32) with unknown specificity and absence of intrinsic polyreactivity as a model to study the potential of heme to induce polyreactivity of antibodies. We demonstrated that exposure to heme greatly extends the antigen binding potential of Hg32, suggesting that the intrinsic binding promiscuity is not a prerequisite for the induction of polyreactivity by heme. In addition we compared the kinetics and thermodynamics of the interaction of heme-exposed antibodies with a panel of unrelated antigens. These analyses revealed that the two heme-sensitive antibodies adopt different mechanisms of binding to the same set of antigens. This study contributes to understanding the phenomenon of induced antibody polyreactivity. The data may also be of importance for understanding of physiological and pathological roles of polyreactive antibodies. - Highlights: • Exposure of certain monoclonal IgE antibodies to heme results in gain of antigen binding polyreactivity. • Natural polyreactivity of antibodies is dispensable for acquisition of polyreactivity through interaction with heme. • Heme-induced monoclonal IgE antibodies differ in their thermodynamic mechanisms of antigen recognition.

Analysis of IgE binding proteins of mesquite (Prosopis juliflora) pollen and cross-reactivity with predominant tree pollens.

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Dhyani, Anamika; Arora, Naveen; Gaur, Shailendra N; Jain, Vikram K; Sridhara, Susheela; Singh, Bhanu P

2006-01-01

Pollen from the mesquite tree, Prosopis juliflora, is an important source of respiratory allergy in tropical countries. Our aim was to partially characterize the IgE binding proteins of P. juliflora pollen extract and study cross-reactivity with prevalent tree pollen allergens. Intradermal tests with P. juliflora and five other tree pollen extracts were performed on respiratory allergy patients from Bikaner (arid) and Delhi (semi arid). Prosopis extract elicited positive skin reactions in 71/220 of the patients. Sera were collected from 38 of these 71 patients and all demonstrated elevated specific IgE to P. juliflora. Immunoblotting with pooled patients' sera demonstrated 16 IgE binding components, with components of 24, 26, 29, 31, 35, 52, 58, 66 and 95 kDa recognized by more than 80% of individual patients' sera. P. juliflora extract is allergenically potent requiring 73 ng of self-protein for 50% inhibition of IgE binding in ELISA inhibition. Cross-inhibition assays showed close relationship among P. juliflora, Ailanthus excelsa, Cassia siamea and Salvadora persica. IgE binding components of 14, 41, 52 and 66 kDa were shared allergens whereas 26 and 29 kDa were specific to P. juliflora. The findings suggest that purification of cross-reactive allergens will be helpful for diagnosis and immunotherapy of tree pollen allergic patients.

Presence of functional, autoreactive human milk-specific IgE in infants with cow's milk allergy.

Science.gov (United States)

Järvinen, K M; Geller, L; Bencharitiwong, R; Sampson, H A

2012-02-01

Occasionally, exclusively breastfed infants with cow's milk allergy (CMA) remain symptomatic despite strict maternal milk avoidance. To determine whether or not persistence of symptoms could be due to sensitization against endogenous human milk proteins with a high degree of similarity to bovine allergens. Ten peptides representing known bovine milk IgE-binding epitopes [α-lactalbumin (ALA), β- and κ-casein] and the corresponding, highly homologous human milk peptides were labelled with sera from 15 breastfed infants with CMA, aged 3 weeks to 12 months, and peptide (epitope)-specific IgE antibodies were assessed. Nine of the 15 breastfed infants became asymptomatic during strict maternal avoidance of milk and other major food allergens; six infants remained symptomatic until weaned. Ten older children, aged 5-15 years, with CMA were also assessed. The functional capacity of specific IgE antibodies was assessed by measuring β-hexosaminidase release from rat basophilic leukaemia cells passively sensitized and stimulated with human and bovine ALA. A minimum of one human milk peptide was recognized by IgE antibodies from 9 of 15 (60%) milk-allergic infants, and the majority of older children with CMA. Genuine sensitization to human milk peptides in the absence of IgE to bovine milk was occasionally seen. There was a trend towards specific IgE being detected to more human milk peptides in those infants who did not respond to the maternal milk elimination diet than in those who did (P = 0.099). Functional IgE antibody to human ALA was only detected in infants not responding to the maternal diet. Endogenous human milk epitopes are recognized by specific IgE from the majority of infants and children with CMA. Such autoreactive, human milk-specific IgE antibodies appear to have functional properties in vitro. Their role in provoking allergic symptoms in infants exclusively breastfed by mothers strictly avoiding dietary milk remains unclear. © 2011 Blackwell

The absence of serum IgE antibodies indicates non-type 2 disease in young asthmatics.

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Tsolakis, N; Malinovschi, A; Nordvall, L; Janson, C; Borres, M P; Alving, K

2018-06-01

Atopic asthma is associated with elevated type-2 biomarkers such as fraction of exhaled nitric oxide (FeNO) and blood eosinophil (B-Eos) count. However, increased type 2 markers have also been reported in traditionally defined non-atopic asthma. To determine a clinically useful level of IgE sensitization for ruling out type 2 asthma. Asthmatics (N = 408; age 10-35 years) were analysed using the multi-allergen tests Phadiatop and fx5 (ImmunoCAP). Subjects were grouped based on IgE-antibody concentrations: ≥0.35 kU A /L for at least one test (n = 326) or <0.35 kU A /L for both tests (n = 82). Τhe latter group was subsequently divided into 2 groups: IgE 0.10-0.34 kU A /L (n = 34) and IgE < 0.10 kU A /L (n = 48). The relationships between type 2 biomarkers, and inadequate asthma control (ACT < 20), reduced lung function (FEV 1  < 80%), recent asthma attacks and airway hyperresponsiveness (AHR) to methacholine were determined. In univariate analyses, at least one type 2 marker related to each asthma outcome in subjects with IgE ≥0.35 kU A /L. In subjects with IgE 0.10-0.34 kU A /L, elevated FeNO related to reduced lung function (P = .008) and B-Eos to AHR (P = .03). No associations were found in subjects with IgE < 0.10 kU A /L. In multivariate analysis, a relationship between FeNO and reduced lung function remained in subjects with IgE < 0.35 kU A /L (P = .03). Clinically relevant elevation of type 2 biomarkers was seen in young asthmatics with IgE antibodies <0.35 kU A /L, but not those with IgE < 0.10 kU A /L. It seems possible to define non-type 2 asthma through sensitive IgE-antibody measurement. © 2018 John Wiley & Sons Ltd.

An Allergen Portrait Gallery: Representative Structures and an Overview of IgE Binding Surfaces

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Ovidiu Ivanciuc

2010-10-01

Full Text Available Recent progress in the biochemical classification and structural determination of allergens and allergen–antibody complexes has enhanced our understanding of the molecular determinants of allergenicity. Databases of allergens and their epitopes have facilitated the clustering of allergens according to their sequences and, more recently, their structures. Groups of similar sequences are identified for allergenic proteins from diverse sources, and all allergens are classified into a limited number of protein structural families. A gallery of experimental structures selected from the protein classes with the largest number of allergens demonstrate the structural diversity of the allergen universe. Further comparison of these structures and identification of areas that are different from innocuous proteins within the same protein family can be used to identify features specific to known allergens. Experimental and computational results related to the determination of IgE binding surfaces and methods to define allergen-specific motifs are highlighted.

Infusion reactions during infliximab treatment are not associated with IgE anti-infliximab antibodies

NARCIS (Netherlands)

van Schie, Karin A.; Ooijevaar-de Heer, Pleuni; Kruithof, Simone; Plasencia, Chamaida; Jurado, Teresa; Pascual Salcedo, Dora; Brandse, Johannan F.; D'Haens, Geert Ram; Wolbink, Gerrit Jan; Rispens, Theo

2017-01-01

Controversy exists on the role of IgE antidrug antibodies (IgE-ADA) in infusion reactions (IR) on infliximab treatment, partly due to the lack of a positive control used for assay validation. We sought to (1) develop a robust assay to measure IgE-ADA, including a positive control, (2) determine the

Specific IgE Antibodies in Young Children with Atopic Dermatitis--Correlation of Multiple Allergen Simultaneous Immunoblot Test and ImmunoCap System.

Science.gov (United States)

Konopka, Ewa; Ceregra, Aldona; Maciorkowska, Elzbieta; Surowska, Barbara; Trojanowska, Ilona; Roszko-Kirpsza, Izabela; Cukrowska, Bozena

2016-01-01

Sensitization to food allergens is a common condition in pediatric atopic dermatitis (AD). Recently, the multiple allergen simultaneous test (MAST) allowing for a comprehensive assessment of atopy has been developed, but the usefulness in young AD children is not known. The aim of this study was to determine IgE specificity in AD children using MAST and to compare the results for selected food allergens with the reference ImmunoCap system. The study enrolled 50 children up to 2 years old with a diagnosis of AD. IgE antibodies were measured with the MAST-immunoblots. Children with specific IgE levels ≥ 0.35 kU/L were identified as sensitized to allergens. Most often children were sensitized to food allergens (egg white and yolk, hazelnuts, potato, cow's milk proteins, wheat flour, codfish, and soybean), but a high percentage of them also had IgE antibodies against house dust mites (12%), grass (10%), and birch (10%). Eight percent of children were sensitized to domestic animals (cats and dogs). Almost perfect (kappa index 0.8 - 1.0) and substantial (kappa index 0.6 - 0.8) agreement between MAST and ImmunoCap was found for food allergens except codfish. Pearson's analysis of antibody classes showed a very strong correlation between two methods (r = 0.8 - 1.0) for egg white, hazelnuts, potato, cow's milk proteins, wheat flour, and soybean, and a strong correlation (r = 0.6 - 0.79) was observed for peanut, egg yolk, and codfish. The study showed the frequent occurrence of IgE antibodies against food and airborne and animal allergens in young AD children and confirmed the usefulness of MAST-immunoblots for screening of sensitization in pediatric patients.

IgE to penicillins with different specificities can be identified by a multiepitope macromolecule: Bihaptenic penicillin structures and IgE specificities.

Science.gov (United States)

Ariza, A; Barrionuevo, E; Mayorga, C; Montañez, M I; Perez-Inestrosa, E; Ruiz-Sánchez, A; Rodríguez-Guéant, R M; Fernández, T D; Guéant, J L; Torres, M J; Blanca, M

2014-04-01

Quantitation of specific IgE by immunoassay is a recommended in vitro test for the diagnosis of immediate hypersensitivity reactions to betalactams (BLs), particularly when skin test results are negative. IgE antibodies that recognize the common nuclear structure of all BLs or the specific side chain structure can be mainly distinguished by immunoassays. The aim of this study was to develop an immunoassay system to detect IgE antibodies with different specificities. Cellulose discs conjugated with benzylpenicillin (BP), amoxicillin (AX) or both drugs, with poly-l-lysine (PLL) as carrier molecule, were used as solid phases in the radioallergosorbent test (RAST). Direct and inhibition radioimmunoassay studies were made to verify the structures recognized by serum IgE antibodies from penicillin-allergic patients. Our results indicated that the addition of both haptens did not decrease the capacity to capture IgE when serum specific to either BP or AX was used, at least in terms of sensitivity. In addition, the inclusion of two haptens improved significantly the levels of IgE detection in patients who recognized both BP and AX. Therefore, the use of a solid phase with a carrier molecule conjugated with two determinants (AX and BP) is helpful to recognize IgE antibodies against either of these determinants and is useful for screening sera with different specificities. Copyright © 2014 Elsevier B.V. All rights reserved.

Polyphenol-Rich Pomegranate Juice Reduces IgE Binding to Cashew Nut Allergens

Science.gov (United States)

Cashew nut allergy is mediated by IgE binding to seed-storage proteins including Ana o 1, 2, and 3. Cashew nuts commonly cause severe reactions and only small amounts are needed. Polyphenol rich juices and polyphenol compounds have been demonstrated to complex with peanut allergens. The interacti...

NOSOTROPIC SUBSTANTIATION OF ANTI IgE ANIBODY THERAPY

Directory of Open Access Journals (Sweden)

Yu.G. Levina

2008-01-01

Full Text Available This article studies the specifics of allergic diseases pathogenesis. Such common allergic diseases as bronchial asthma, allergic rhinitis and atopic dermatitis are conditioned by processes based on increase of immunoglobulin e synthesis. Omalizunab, which is a recombinant humanized monoclone anti-Ige antibody, prevents Ige fixing to membrane receptors of mast cells and significantly reduces the level of immunoglobulin e circulating in blood.Key words: anti-Ige antibody, omalizumab, allergic diseases, Bronchial asthma, children.

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.

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...

Heat-induced alterations in cashew allergen solubility and IgE binding

Directory of Open Access Journals (Sweden)

Christopher P. Mattison

Full Text Available Cashew nuts are an increasingly common cause of food allergy. We compare the soluble protein profile of cashew nuts following heating. SDS-PAGE indicate that heating can alter the solubility of cashew nut proteins. The 11S legumin, Ana o 2, dominates the soluble protein content in ready to eat and mildly heated cashew nuts. However, we found that in dark-roasted cashew nuts, the soluble protein profile shifts and the 2S albumin Ana o 3 composes up to 40% of the soluble protein. Analysis of trypsin-treated extracts by LC/MS/MS indicate changes in the relative number and intensity of peptides. The relative cumulative intensity of the 5 most commonly observed Ana o 1 and 2 peptides are altered by heating, while those of the 5 most commonly observed Ana o 3 peptides remaine relatively constant. ELISA experiments indicate that there is a decrease in rabbit IgG and human serum IgE binding to soluble cashew proteins following heating. Our findings indicate that heating can alter the solubility of cashew allergens, resulting in altered IgE binding. Our results support the use of both Ana o 2 and Ana o 3 as potential cashew allergen diagnostic targets. Keywords: Cashew nut, Food allergy, Immunoglobulin E, Mass-spectrometry, Peptide, Solubility

Methods of quantifying circulating IgE

International Nuclear Information System (INIS)

Merrett, T.G.; Merrett, J.

1978-01-01

Four radioimmunoassay techniques, two conventional and two sandwich, have been used to measure circulating IgE levels in 100 sera. The test sera had IgE levels ranging from 1.0 to 20,000 u/ml, and each was measured at five dilutions, ranging from three-fold to 400-fold. The same IgE standards were used throughout, and the optimal range for each assay was determined by assessing data for quality control sera and the WHO standard 69/204. To be of general use in the United Kingdom an IgE test must measure accurately levels as low as 20-30 u IgE/ml. The Phadebas RIST method failed to meet this criterion, and of the remaining tests the double antibody method had the most useful operating range and produced the most reliable results. However, the double antibody method is not available commercially and so, for the majority of laboratories, the Phadebas PRIST technique should be the method chosen. (author)

Tear and serum IgE concentrations by Tandem-R IgE immunoradiometric assay in allergic patients

International Nuclear Information System (INIS)

Insler, M.S.; Lim, J.M.; Queng, J.T.; Wanissorn, C.; McGovern, J.P.

1987-01-01

The authors studied a population of 39 allergic and 15 nonallergic patients, and determined their tear and serum IgE concentrations. Samples of tear and serum were tested for IgE by the Tandem-R immunoradiometric assay, which uses monoclonal antibody to produce a specific assay for IgE. The serum IgE levels in the study group showed a range from 23,280 to 16 IU/ml compared with controls of 72 to 2 IU/ml. Tear IgE in the study group varied from 159 IU/ml to less than 1 IU/ml compared with controls of 8 IU/ml to less than 1 IU/ml. A statistically significant correlation between tear and serum IgE exists in the allergic patients with eye symptoms. It also exists when serum IgE was greater than 100 IU/ml, the tear IgE greater than 4 IU/ml, or when both the serum IgE was greater than 100 IU/ml and the tear IgE greater than 4 IU/ml

Specific binding assay technique; standardization of reagent

International Nuclear Information System (INIS)

Huggins, K.G.; Roitt, I.M.

1979-01-01

The standardization of a labelled constituent, such as anti-IgE, for use in a specific binding assay method is disclosed. A labelled ligand, such as IgE, is standardized against a ligand reference substance, such as WHO standard IgE, to determine the weight of IgE protein represented by the labelled ligand. Anti-light chain antibodies are contacted with varying concentrations of the labelled ligand. The ligand is then contacted with the labelled constituent which is then quantitated in relation to the amount of ligand protein present. The preparation of 131 I-labelled IgE is described. Also disclosed is an improved specific binding assay test method for determining the potency of an allergen extract in serum from an allergic individual. The improvement involved using a parallel model system of a second complex which consisted of anti-light chain antibodies, labelled ligand and the standardized labelled constituent (anti-IgE). The amount of standardized labelled constituent bound to the ligand in the first complex was determined, as described above, and the weight of ligand inhibited by addition of soluble allergen was then used as a measure of the potency of the allergen extract. (author)

Regulation of IgE antibody production by serum molecules. II. Strain-specificity of the suppressive activity of serum from complete Freund's adjuvant-immune low responder mouse donors

International Nuclear Information System (INIS)

Katz, D.H.; Tung, A.S.

1978-01-01

IgE antibody production in mice of high and low IgE responder phenotypes, respectively, can be appreciably enhanced in magnitude after low-dose whole-body x irradiation. Such enhanced responses, as well as adoptive secondary IgE responses, can be markedly suppressed by passive transfer of CFA-immune serum in low responder strains, but not in high responder strains. The studies presented here demonstrate that the suppressive activity of CFA-immune serum on IgE antibody production is strain specific. This is true even in reciprocal combinations of low IgE responder SJL and C57BL/6 mice, in which it was shown that serum capable of suppressing mice of the isologous strain was ineffective in diminishing IgE antibody production in the other low responder strain. Absence of suppressive activity in CFA-immune sera obtained from H-2 haplotypes while sharing many similarities in the background genome and, conversely, effective suppressive activity of H-2 congenic donor sera when H-2-identities between donor and recipient mice existed, strongly suggested a role, at least in part, of H-2 genes in dictating the strain specificity of such suppressive activity. Additional experiments provided evidence for a possible role of macrophages in catabolism of the active molecules in CFA-immune sera. These observations, together with those presented in the preceding paper, may provide valuable insight toward successful development of appropriate manipulations that could ultimately convert high IgE responder individuals into low responders

125I-Clq-binding and specific antibodies as indicators of pulmonary disease activity in cystic fibrosis

International Nuclear Information System (INIS)

Moss, R.B.; Hsu, Y.P.; Lewiston, N.J.

1981-01-01

We studied the incidence and levels of circulating immune complexes by the 125 I-Clq-binding assay in patients with cystic fibrosis in relation to clinical respiratory status and specific IgG and IgE antibodies to Pseudomonas aeruginosa. Staphylococcus aureus, Aspergillus fumigatus, and Candida albicans. Overall prevalence of CIC was 43%, but 86% of serially studied patients had evidence of CIC at some time. Patients with acute respiratory exacerbations and deteriorating pulmonary function had a higher incidence of CIC (76%) as compared to stable patients (36%, P less than 0.01), as well as significantly higher levels of CIC. Acute exacerbations were also associated with significant increases in IgG antibody to Pseudomonas (P less than 0.005) but not in other antibodies. CIC did not correlate with Pseudomonas-specific IgG nor with any other specific antibody studied. A variety of age-related differences in specific antibody levels were seen. The episodic appearance of CIC is common in CF and is usually associated with exacerbation of lung disease

Variability of crossreactivity of IgE antibodies to group I and V allergens in eight grass pollen species

NARCIS (Netherlands)

van Ree, R.; Driessen, M. N.; van Leeuwen, W. A.; Stapel, S. O.; Aalberse, R. C.

1992-01-01

Crossreactivity to Dactylis glomerata, Festuca rubra, Phleum pratense, Anthoxanthum odoratum, Secale cereale, Zea mays, and Phragmites communis of IgE antibodies against Lol p I or Lol p V was investigated by means of RAST-inhibition. Within a group of sera the degree of crossreactivity was

IgE antibodies, FcεRIα, and IgE-mediated local anaphylaxis can limit snake venom toxicity.

Science.gov (United States)

Starkl, Philipp; Marichal, Thomas; Gaudenzio, Nicolas; Reber, Laurent Lionel; Sibilano, Riccardo; Tsai, Mindy; Galli, Stephen Joseph

2016-01-01

Type 2 cytokine-related immune responses associated with development of antigen-specific IgE antibodies can contribute to pathology in patients with allergic diseases and to fatal anaphylaxis. However, recent findings in mice indicate that IgE also can enhance defense against honeybee venom. We tested whether IgE antibodies, IgE-dependent effector mechanisms, and a local anaphylactic reaction to an unrelated antigen can enhance defense against Russell viper venom (RVV) and determined whether such responses can be influenced by immunization protocol or mouse strain. We compared the resistance of RVV-immunized wild-type, IgE-deficient, and Fcer1a-deficient mice after injection of a potentially lethal dose of RVV. A single prior exposure to RVV enhanced the ability of wild-type mice, but not mice lacking IgE or functional FcεRI, to survive challenge with a potentially lethal amount of RVV. Moreover, IgE-dependent local passive cutaneous anaphylaxis in response to challenge with an antigen not naturally present in RVV significantly enhanced resistance to the venom. Finally, we observed different effects on resistance to RVV or honeybee venom in BALB/c versus C57BL/6 mice that had received a second exposure to that venom before challenge with a high dose of that venom. These observations illustrate the potential benefit of IgE-dependent effector mechanisms in acquired host defense against venoms. The extent to which type 2 immune responses against venoms can decrease pathology associated with envenomation seems to be influenced by the type of venom, the frequency of venom exposure, and the genetic background of the host. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Beyond Antibodies as Binding Partners: The Role of Antibody Mimetics in Bioanalysis.

Science.gov (United States)

Yu, Xiaowen; Yang, Yu-Ping; Dikici, Emre; Deo, Sapna K; Daunert, Sylvia

2017-06-12

The emergence of novel binding proteins or antibody mimetics capable of binding to ligand analytes in a manner analogous to that of the antigen-antibody interaction has spurred increased interest in the biotechnology and bioanalytical communities. The goal is to produce antibody mimetics designed to outperform antibodies with regard to binding affinities, cellular and tumor penetration, large-scale production, and temperature and pH stability. The generation of antibody mimetics with tailored characteristics involves the identification of a naturally occurring protein scaffold as a template that binds to a desired ligand. This scaffold is then engineered to create a superior binder by first creating a library that is then subjected to a series of selection steps. Antibody mimetics have been successfully used in the development of binding assays for the detection of analytes in biological samples, as well as in separation methods, cancer therapy, targeted drug delivery, and in vivo imaging. This review describes recent advances in the field of antibody mimetics and their applications in bioanalytical chemistry, specifically in diagnostics and other analytical methods.

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.

Pulsed Ultraviolet Light Reduces Immunoglobulin E Binding to Atlantic White Shrimp (Litopenaeus setiferus Extract

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Si-Yin Chung

2011-06-01

Full Text Available Pulsed ultraviolet light (PUV, a novel food processing and preservation technology, has been shown to reduce allergen levels in peanut and soybean samples. In this study, the efficacy of using PUV to reduce the reactivity of the major shrimp allergen, tropomyosin (36-kDa, and to attenuate immunoglobulin E (IgE binding to shrimp extract was examined. Atlantic white shrimp (Litopenaeus setiferus extract was treated with PUV (3 pulses/s, 10 cm from light source for 4 min. Tropomyosin was compared in the untreated, boiled, PUV-treated and [boiled+PUV]-treated samples, and changes in the tropomyosin levels were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. IgE binding of the treated extract was analyzed via immunoblot and enzyme-linked immunosorbent assay (ELISA using pooled human plasma containing IgE antibodies against shrimp allergens. Results showed that levels of tropomyosin and IgE binding were reduced following PUV treatment. However, boiling increased IgE binding, while PUV treatment could offset the increased allergen reactivity caused by boiling. In conclusion, PUV treatment reduced the reactivity of the major shrimp allergen, tropomyosin, and decreased the IgE binding capacity of the shrimp extract.

Determination of IgE rheumatoid factor

International Nuclear Information System (INIS)

Herrmann, D.; Schlenvoigt, G.; Jaeger, L.

1987-01-01

A solid-phase radioimmunoassay and an enzyme-linked immunosorbent assay have been developed for the identification of IgE rheumatoid factor (IgE RF). For both, human IgG was used as antigen. Bound IgE RF was detected by means of commercially available rabbit anti-human IgE antiserum and 125 I-labelled sheep anti-rabbit IgG as well as monoclonal anti-human-ε-chain antibody and horse-radish peroxidase-labelled sheep anti-mouse IgG. The presence of IgM RF did not cause false positive results. Correlation in the results of both assays were significant, the reproducibility was very good. In 50.6% of 79 sera from patients with rheumatoid arthritis IgE RF has been detected with both or one of the methods. Only in 1 out of 12 seronegative rheumatoid arthritis sera IgE RF was identified. (author)

98 Specific IGE and IGG Binding to Allergoids of Phleum pratense

OpenAIRE

Cases, Barbara; Fernandez-Caldas, Enrique; Tudela, Jose Ignacio; Fernandez, Eva Abel; Sanchez-Garcia, Silvia; Ibañez, M. Dolores; Escudero, Carmelo; Casanovas, Miguel

2012-01-01

Background Allergoids were first used in the decades of the 60s and 70s of the last century as an effective treatment of allergic respiratory diseases. Allergoids can be modified with formaldehyde or glutaraldehyde. Modified allergens, or allergoids, decrease the risk of adverse reactions while administering higher allergen doses. The objective of this study was to analyse specific IgE and IgG binding to glutaraldehyde modified and non-modified allergen extracts of Phleum pratense. Methods Th...

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

Identification of IgE- binding pollen protein from Cannabis sativa in pollen-hypersensitive patients from north Pakistan.

Science.gov (United States)

Choudhary, Shazia; Murad, Sheeba; Hayat, Muhammad Qasim; Shakoor, Zahid; Arshad, Muhammad

2017-01-01

Cannabis sativa (C.sativa) is well-known for its medicinal, industrial and recreational use. However, allergies in relation to Cannabis sativa (C.sativa) are rarely reported. C. sativa is one of the common weeds found in Pakistan and its pollen grains are common in spring and fall season. Although categorized as an aeroallergen, there are limited number of reports regarding allergenic potential in C. sativa. Therefore, the current study is aimed at exploring the IgE- binding potential among the C. sativa pollen in local pollen allergic patients. Initial screening of C. sativa sensitized individuals was carried out by dot blot from the sera of pollen allergic patients. Proteins from the pollen grains were extracted and resolved on 10% gel. Eight bands were visible on gel however only one protein fragment i.e. of 14KDa size was found to bind to IgE as analyzed through protein gel blot analysis. Strong IgE affinity of a 14 kDa protein fragment from C. sativa pollen extract suggests its allergenic potential. Further study is required to find the exact nature of this protein fragment.

Staphylococcal superantigen-specific IgE antibodies: degree of sensitization and association with severity of asthma

OpenAIRE

Elabras Filho, José; Mello, Fernanda Carvalho de Queiroz; Lupi, Omar; Bica, Blanca Elena Rios Gomes; Papi, José Angelo de Souza; França, Alfeu Tavares

2016-01-01

ABSTRACT Objective: To determine the presence of staphylococcal superantigen-specific IgE antibodies and degree of IgE-mediated sensitization, as well as whether or not those are associated with the severity of asthma in adult patients. Methods: This was a cross-sectional study involving outpatients with asthma under treatment at a tertiary care university hospital in the city of Rio de Janeiro, Brazil. Consecutive patients were divided into two groups according to the severity of asthma ba...

Silencing ß1,2-xylosyltransferase in transgenic tomato fruits reveals xylose as constitutive component of IgE binding epitopes

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Kathrin Elisabeth Paulus

2011-08-01

Full Text Available Complex plant N-glycans containing β1,2-xylose and core α1,3-fucose are regarded as the major class of the so-called ‘carbohydrate cross-reactive determinants’ reactive with IgE antibodies in sera of many allergic patients, but their clinical relevance is still under debate. Plant glycosyltransferases, β1,2-xylosyltransferase (XylT and core α1,3-fucosyltransferase (FucT are responsible for the transfer of β1,2-linked xylose and core α1,3-linked fucose residues to N-glycans of glycoproteins, respectively. To test the clinical relevance of ß 1,2-xylose containing epitopes, expression of the tomato β1,2-xylosyltransferase was down-regulated by RNA interference (RNAi in transgenic plants. Fruits harvested from these transgenic plants were analysed for accumulation of XylT mRNA, abundance of ß1,2-xylose epitopes and their allergenic potential. Based on qPCR analysis XylT mRNA levels were reduced up to 10-fold in independent transgenic lines as compared to untransformed control, whereas no xylosylated N-glycans could be revealed by MS analysis. Immunoblotting using anti-xylose-specific IgG antibodies revealed a strong reduction of ß1,2-xylose containing epitopes. Incubating protein extracts from untransformed controls and XylT_RNAi plants with sera from tomato allergic patients showed a patient-specific reduction in IgE binding, indicating a reduced allergenic potential of XylT_RNAi tomato fruits, in vitro. To elucidate the clinical relevance of ß1,2-xylose containing complex N-glycans skin prick tests were performed demonstrating a reduced responsiveness of tomato allergic patients, in vivo. This study provides strong evidence for the clinical relevance of ß1,2-xylose containing epitopes in vivo.

Omalizumab decreases IgE production in patients with allergic (IgE-mediated) asthma; PKPD analysis of a biomarker, total IgE

Science.gov (United States)

Lowe, Philip J; Renard, Didier

2011-01-01

AIM To determine whether excessive IgE production by patients with atopic allergic asthma decreases with omalizumab therapy. METHODS Omalizumab, free and total IgE data were obtained from an epidemiological study and six randomized, double-blind, placebo-controlled trials in patients with allergic asthma. The binding between omalizumab and IgE together with the production and elimination of IgE were modelled as previously, except that, in order to explain why total IgE was decreasing over a period of 5 years, the expression of IgE was allowed to change. RESULTS The prior constant IgE production model failed to converge on the data once long-term observations were included, whereas models allowing IgE production to decrease fitted. A feedback model indicated that, on average, IgE production decreased by 54% per year. This model was further developed with covariate searches indicating clinically small but statistically significant effects of age, gender, body mass index and race on some parameters. Model predictions were checked internally and externally against 3–5 year data from paediatric and adult atopic asthmatic patients and externally against extensive total IgE data from a long-duration (>1 year) phase 1 study which was not used in the model building. CONCLUSIONS A pharmacokinetic–pharmacodynamic model incorporating omalizumab–IgE binding and feedback for control of IgE production indicates that omalizumab reduces production of IgE. This raises the possibility that indefinite treatment may not be required, only for perhaps a few years. After the initial accumulation, total IgE should provide a means to monitor IgE production and guide individual treatment decisions. PMID:21392073

Allosteric mechanism of action of the therapeutic anti-IgE antibody omalizumab.

Science.gov (United States)

Davies, Anna M; Allan, Elizabeth G; Keeble, Anthony H; Delgado, Jean; Cossins, Benjamin P; Mitropoulou, Alkistis N; Pang, Marie O Y; Ceska, Tom; Beavil, Andrew J; Craggs, Graham; Westwood, Marta; Henry, Alistair J; McDonnell, James M; Sutton, Brian J

2017-06-16

Immunoglobulin E and its interactions with receptors FcϵRI and CD23 play a central role in allergic disease. Omalizumab, a clinically approved therapeutic antibody, inhibits the interaction between IgE and FcϵRI, preventing mast cell and basophil activation, and blocks IgE binding to CD23 on B cells and antigen-presenting cells. We solved the crystal structure of the complex between an omalizumab-derived Fab and IgE-Fc, with one Fab bound to each Cϵ3 domain. Free IgE-Fc adopts an acutely bent structure, but in the complex it is only partially bent, with large-scale conformational changes in the Cϵ3 domains that inhibit the interaction with FcϵRI. CD23 binding is inhibited sterically due to overlapping binding sites on each Cϵ3 domain. Studies of omalizumab Fab binding in solution demonstrate the allosteric basis for FcϵRI inhibition and, together with the structure, reveal how omalizumab may accelerate dissociation of receptor-bound IgE from FcϵRI, exploiting the intrinsic flexibility and allosteric potential of IgE. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

IgE antipolymyxin B antibody formation in a T cell-depleted bone marrow transplant patient

International Nuclear Information System (INIS)

Lakin, J.D.; Grace, W.R.; Sell, K.W.

1975-01-01

The production of IgE-class antibody specific for polymyxin B is documented in an 18-year-old white female acute myelocytic leukemic patient in relapse. The patient was rendered T cell--deficient by total-body x irradiation and antihuman thymocyte globulin for the purpose of bone marrow transplantation. Thereafter, symptoms of nasal congestion, rhinorrhea, and perinasal urtication produced by topical application of a polymyxin solution were noted. Reaginic activity mediated by an IgE antibody against polymyxin is documented by Prausnitz-Kuestner--type passive transfer reactions and by an indirect hemagglutination technique developed for these studies. The occurrence of type I hypersensitivity to this topical antibiotic is rare. It is speculated that pharmaceuticals normally having a low sensitizing potential might demonstrate increased reaginic immunogenicity in a spontaneously or iatrogenically T cell-depleted patient

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.

A Cross-Reactive Human Single-Chain Antibody for Detection of Major Fish Allergens, Parvalbumins, and Identification of a Major IgE-Binding Epitope.

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Merima Bublin

Full Text Available Fish allergy is associated with moderate to severe IgE-mediated reactions to the calcium binding parvalbumins present in fish muscle. Allergy to multiple fish species is caused by parvalbumin-specific cross-reactive IgE recognizing conserved epitopes. In this study, we aimed to produce cross-reactive single chain variable fragment (scFv antibodies for the detection of parvalbumins in fish extracts and the identification of IgE epitopes. Parvalbumin-specific phage clones were isolated from the human ETH-2 phage display library by three rounds of biopanning either against cod parvalbumin or by sequential biopanning against cod (Gad m 1, carp (Cyp c 1 and rainbow trout (Onc m 1 parvalbumins. While biopanning against Gad m 1 resulted in the selection of clones specific exclusively for Gad m 1, the second approach resulted in the selection of clones cross-reacting with all three parvalbumins. Two clones, scFv-gco9 recognizing all three parvalbumins, and scFv-goo8 recognizing only Gad m 1 were expressed in the E. coli non-suppressor strain HB2151 and purified from the periplasm. scFv-gco9 showed highly selective binding to parvalbumins in processed fish products such as breaded cod sticks, fried carp and smoked trout in Western blots. In addition, the scFv-gco9-AP produced as alkaline phosphatase fusion protein, allowed a single-step detection of the parvalbumins. In competitive ELISA, scFv-gco9 was able to inhibit binding of IgE from fish allergic patients' sera to all three β-parvalbumins by up to 80%, whereas inhibition by scFv-goo8 was up to 20%. 1H/15N HSQC NMR analysis of the rGad m 1:scFv-gco9 complex showed participation of amino acid residues conserved among these three parvalbumins explaining their cross-reactivity on a molecular level. In this study, we have demonstrated an approach for the selection of cross-reactive parvalbumin-specific antibodies that can be used for allergen detection and for mapping of conserved epitopes.

A Cross-Reactive Human Single-Chain Antibody for Detection of Major Fish Allergens, Parvalbumins, and Identification of a Major IgE-Binding Epitope.

Science.gov (United States)

Bublin, Merima; Kostadinova, Maria; Fuchs, Julian E; Ackerbauer, Daniela; Moraes, Adolfo H; Almeida, Fabio C L; Lengger, Nina; Hafner, Christine; Ebner, Christof; Radauer, Christian; Liedl, Klaus R; Valente, Ana Paula; Breiteneder, Heimo

2015-01-01

Fish allergy is associated with moderate to severe IgE-mediated reactions to the calcium binding parvalbumins present in fish muscle. Allergy to multiple fish species is caused by parvalbumin-specific cross-reactive IgE recognizing conserved epitopes. In this study, we aimed to produce cross-reactive single chain variable fragment (scFv) antibodies for the detection of parvalbumins in fish extracts and the identification of IgE epitopes. Parvalbumin-specific phage clones were isolated from the human ETH-2 phage display library by three rounds of biopanning either against cod parvalbumin or by sequential biopanning against cod (Gad m 1), carp (Cyp c 1) and rainbow trout (Onc m 1) parvalbumins. While biopanning against Gad m 1 resulted in the selection of clones specific exclusively for Gad m 1, the second approach resulted in the selection of clones cross-reacting with all three parvalbumins. Two clones, scFv-gco9 recognizing all three parvalbumins, and scFv-goo8 recognizing only Gad m 1 were expressed in the E. coli non-suppressor strain HB2151 and purified from the periplasm. scFv-gco9 showed highly selective binding to parvalbumins in processed fish products such as breaded cod sticks, fried carp and smoked trout in Western blots. In addition, the scFv-gco9-AP produced as alkaline phosphatase fusion protein, allowed a single-step detection of the parvalbumins. In competitive ELISA, scFv-gco9 was able to inhibit binding of IgE from fish allergic patients' sera to all three β-parvalbumins by up to 80%, whereas inhibition by scFv-goo8 was up to 20%. 1H/15N HSQC NMR analysis of the rGad m 1:scFv-gco9 complex showed participation of amino acid residues conserved among these three parvalbumins explaining their cross-reactivity on a molecular level. In this study, we have demonstrated an approach for the selection of cross-reactive parvalbumin-specific antibodies that can be used for allergen detection and for mapping of conserved epitopes.

Contribution of Phadebas IgE test to typification of allergic patients

International Nuclear Information System (INIS)

Cap, J.; Spanar, E.; Holan, J.; Zahradny, V.

1976-01-01

Experience is reported with the examination of serum immunoglobulin E in a control group (n=22), in a group of asthmatics with bacterial allergy (n=25) and in a group of asthmatics with antibody allergy (n=33). In the examination by radioimmunosorbent method (Phadebas IgE Test) the levels of IgE over 500 mU/ml were considered as proof of allergy of the antibody type where other etiological factors could be excluded. A marked immunosuppressive effect of corticoids on the level of IgE is pointed out. The method mentioned is considered as suitable for the objective typification of allergic patients. (author)

Determination of IgE antibodies to Polistes dominulus, Vespula germanica and Vespa crabro in sera of patients allergic to vespids.

Science.gov (United States)

Blanca, M; Garcia, F; Miranda, A; Carmona, M J; Garcia, J; Fernandez, J; Terrados, S; Vega, J M; Juarez, C

1991-02-01

The study was undertaken to investigate the presence of IgE antibodies to Polistes dominulus (PD), Vespula germanica (VG) and Vespa crabro (VC) in a large group of sera belonging to patients sensitized to Vespids in Spain. RAST values showed that although the majority of patients had IgE antibodies to PD, VG and VC, there was a marked predominance of PD. These results were related to the distribution of the insect in the areas where the sera were obtained. Due to geographical and insect distribution differences, the whole area was divided into three zones: Central, East and South. Comparison of the positive RAST values obtained indicated that, although the positivity to PD predominated over VG and this over VC, there were significant differences in percentage positivities to each vespid in the different regions studied. The results of the RAST absorption studies indicated that in most instances patients were originally sensitized to one vespid and were RAST positive to the other venoms due to cross-reactivity. Only in a minority of cases were coexisting antibodies to two insects present. These results show that PD and VG are the important vespids followed to a lesser extent by VC. This study provides relevant information concerning insect distribution sensitivity in a European country.

Molecular Allergen-Specific IgE Assays as a Complement to Allergen Extract-Based Sensitization Assessment

NARCIS (Netherlands)

Aalberse, Rob C.; Aalberse, Joost A.

2015-01-01

Molecular allergen-based component-resolved diagnostic IgE antibody tests have emerged in the form of singleplex assays and multiplex arrays. They use both native and recombinant allergen molecules, sometimes in combination with each other, to supplement allergen extract-based IgE antibody analyses.

A mechanism-based binding model for the population pharmacokinetics and pharmacodynamics of omalizumab

Science.gov (United States)

Hayashi, Naoto; Tsukamoto, Yuko; Sallas, William M; Lowe, Philip J

2007-01-01

Aim Omalizumab, a humanized IgG monoclonal antibody that binds to human immunoglobulin E (IgE), interrupts the allergic cascade in asthmatic patients. The aim was to compare simultaneously drug exposure and IgE biomarker responses in Japanese and White patient populations. Methods An instantaneous equilibrium drug–ligand binding and turnover population model was built from 202 Japanese patients. A posterior predictive evaluation for the steady-state distributions of omalizumab and IgE was then carried out against 531 White patients. Results The mean parameters estimated from the Japanese patients were as follows: omalizumab clearance 7.32 ± 0.153 ml h−1, IgE clearance 71.0 ± 4.68 ml h−1 and the difference between that for omalizumab and the complex 5.86 ± 0.920 ml h−1, the volume of distribution for omalizumab and IgE 5900 ± 107 ml, and that for the complex 3630 ± 223 ml, the rate of IgE production 30.3 ± 2.04 µg h−1. Half-lives of IgG (23 days) and IgE (2.4 days) were close to previous reports. The dissociation constant for binding, 1.07 nM, was similar to in vitro values. Clearance and volume of distribution for omalizumab varied with bodyweight, whereas the clearance and rate of production of IgE were predicted accurately by baseline IgE. Overall, these covariates explained much of the interindividual variability. Conclusions The predictiveness of the Japanese model was confirmed by Monte-Carlo simulations for a White population, also providing evidence that the pharmacokinetics of omalizumab and IgE were similar in these two populations. Furthermore, the model enabled the estimation of not only omalizumab disposition parameters, but also the binding with and the rate of production, distribution and elimination of its target, IgE. PMID:17096680

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.

Comparison of an enzyme linked immunosorbent assay (ELISA) and a radioallergosorbent test (RAST) for detection of IgE antibodies to Brugia malayi

NARCIS (Netherlands)

Wahyuni, Sitti; van Ree, Ronald; Mangali, Andarias; Supali, Taniawati; Yazdanbakhsh, Maria; Sartono, Erliyani

2003-01-01

The enzyme linked immunosorbent assay (ELISA) for specific IgE antibodies to Brugia malayi was compared with the radioallergosorbent test (RAST) for use in immunoepidemiological studies of lymphatic filariasis. Sera used were from individuals (aged 5-82 years) living in an area endemic for lymphatic

Population PK and IgE pharmacodynamic analysis of a fully human monoclonal antibody against IL4 receptor.

Science.gov (United States)

Kakkar, Tarundeep; Sung, Cynthia; Gibiansky, Leonid; Vu, Thuy; Narayanan, Adimoolam; Lin, Shao-Lee; Vincent, Michael; Banfield, Christopher; Colbert, Alex; Hoofring, Sarah; Starcevic, Marta; Ma, Peiming

2011-10-01

For AMG 317, a fully human monoclonal antibody to interleukin receptor IL-4Rα, we developed a population pharmacokinetic (PK) model by fitting data from four early phase clinical trials of intravenous and subcutaneous (SC) routes simultaneously, investigated important PK covariates, and explored the relationship between exposure and IgE response. Data for 294 subjects and 2183 AMG 317 plasma concentrations from three Phase 1 and 1 Phase 2 studies were analyzed by nonlinear mixed effects modeling using first-order conditional estimation with interaction. The relationship of IgE response with post hoc estimates of exposure generated from the final PK model was explored based on data from asthmatic patients. The best structural model was a two-compartment quasi-steady-state target-mediated drug disposition model with linear and non-linear clearances. For a typical 80-kg, 40-year subject, linear clearance was 35.0 mL/hr, central and peripheral volumes of distribution were 1.78 and 5.03 L, respectively, and SC bioavailability was 24.3%. Body weight was an important covariate on linear clearance and central volume; age influenced absorption rate. A significant treatment effect was observable between the cumulative AUC and IgE response measured. The population PK model adequately described AMG 317 PK from IV and SC routes over a 60-fold range of doses with two dosing strengths across multiple studies covering healthy volunteers and patients with mild to severe asthma. IgE response across a range of doses and over the sampling time points was found to be related to cumulative AMG 317 exposure.

Role and Redirection of IgE against Cancer

Directory of Open Access Journals (Sweden)

Elisa A. Nigro

2013-05-01

Full Text Available IgE is a highly elusive antibody class, yet a tremendously powerful elicitor of immune reactions. Despite huge efforts spent on the characterization and understanding of the IgE system many questions remain either unanswered or only marginally addressed. One above all relates to the role of IgE. A common doubt is based on whether IgE mode of action should only be relegated to anti-parasite immunity and allergic manifestations. In search for a hidden role of IgE, reports from several laboratories are described herein in which a natural IgE link to cancer or the experimental redirection of IgE against cancer have been investigated. Epidemiological and investigational studies are trying to elucidate a possible direct intervention of endogenous IgE against cancer, raising thus far no definitive evidence. Conversely, experimental approaches implementing several strategies and engineered IgE formats built up a series of convincing results indicating that cancer might be tackled by the effector functions of this immunoglobulin class. Because of its peculiar immune features, IgE may present a superior anti-tumor performance as compared to IgG. However, extreme care should be taken on how IgE-based anti-tumor approaches should be devised. Overall, IgE appears as a promising resource, likely destined to enrich the anti-cancer arsenal.

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

Determination of IgE antibodies to the benzylpenicilloyl determinant: a comparison of the sensitivity and specificity of three radio allergo sorbent test methods.

Science.gov (United States)

Garcia, J J; Blanca, M; Moreno, F; Vega, J M; Mayorga, C; Fernandez, J; Juarez, C; Romano, A; de Ramon, E

1997-01-01

The quantitation of in vitro IgE antibodies to the benzylpenicilloyl determinant (BPO) is a useful tool for evaluating suspected penicillin allergic subjects. Although many different methods have been employed, few studies have compared their diagnostic specificity and sensitivity. In this study, the sensitivity and specificity of three different radio allergo sorbent test (RAST) methods for quantitating specific IgE antibodies to the BPO determinant were compared. Thirty positive control sera (serum samples from penicillin allergic subjects with a positive clinical history and a positive penicillin skin test) and 30 negative control sera (sera from subjects with no history of penicillin allergy and negative skin tests) were tested for BPO-specific IgE antibodies by RAST using three different conjugates coupled to the solid phase: benzylpenicillin conjugated to polylysine (BPO-PLL), benzylpenicillin conjugated to human serum albumin (BPO-HSA), and benzylpenicillin conjugated to an aminospacer (BPO-SP). Receiver operator control curves (ROC analysis) were carried out by determining different cut-off points between positive and negative values. Contingence tables were constructed and sensitivity, specificity, negative predictive values (PV-), and positive predictive values (PV+) were calculated. Pearson correlation coefficients (r) and intraclass correlation coefficients (ICC) were determined and the differences between methods were compared by chi 2 analysis. Analysis of the areas defined by the ROC curves showed statistical differences among the three methods. When cut-off points for optimal sensitivity and specificity were chosen, the BPO-HSA assay was less sensitive and less specific and had a lower PV- and PV+ than the BPO-PLL and BPO-SP assays. Assessment of r and ICC indicated that the correlation was very high, but the concordance between the PLL and SP methods was higher than between the PLL and HSA or SP and HSA methods. We conclude that for quantitating IgE

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.)

Conformational plasticity at the IgE-binding site of the B-cell receptor CD23.

Science.gov (United States)

Dhaliwal, Balvinder; Pang, Marie O Y; Yuan, Daopeng; Yahya, Norhakim; Fabiane, Stella M; McDonnell, James M; Gould, Hannah J; Beavil, Andrew J; Sutton, Brian J

2013-12-01

IgE antibodies play a central role in allergic disease. They recognize allergens via their Fab regions, whilst their effector functions are controlled through interactions of the Fc region with two principal cell surface receptors, FcɛRI and CD23. Crosslinking of FcɛRI-bound IgE on mast cells and basophils by allergen initiates an immediate inflammatory response, while the interaction of IgE with CD23 on B-cells regulates IgE production. We have determined the structures of the C-type lectin "head" domain of CD23 from seven crystal forms. The thirty-five independent structures reveal extensive conformational plasticity in two loops that are critical for IgE binding. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

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.

Binding-site analysis of opioid receptors using monoclonal anti-idiotypic antibodies

International Nuclear Information System (INIS)

Conroy, W.G.

1988-01-01

Structural relatedness between the variable region of anti-ligand antibodies and opioid binding sites allowed the generation of anti-idiotypic antibodies which recognized opioid receptors. The IgG 3 k antibodies which bound to opioid receptors were obtained when an anti-morphine antiserum was the idiotype. Both antibodies bound to opioid receptors, but only one of these blocked the binding of [ 3 H]naloxone. The antibody which did not inhibit the binding of [ 3 H]naloxone was itself displaced from the receptor by opioid ligands. The unique binding properties displayed by this antibody indicated that anti-idiotypic antibodies are not always a perfect image of the original ligand, and therefore may be more useful than typical ligands as probes for the receptor. An auto-anti-idiotypic technique was successfully used to obtain anti-opioid receptor antibodies. Another IgG 3 k antibody that blocked the binding of [ 3 H]naloxone to rat brain opioid receptors was obtained when a mouse was immunized with naloxone conjugated to bovine serum albumin. These data confirmed that an idiotype-anti-idiotype network which can generate an anti-receptor antibody normally functions when an opioid ligand is introduced into an animal in an immunogenic form

IgE-binding capacity of recombinant timothy grass (Phleum pratense) pollen allergens

NARCIS (Netherlands)

Laffer, S.; Vrtala, S.; Duchêne, M.; van Ree, R.; Kraft, D.; Scheiner, O.; Valenta, R.

1994-01-01

A panel of 60 cDNA clones coding for IgE-binding proteins from timothy grass pollen was immunocharacterized with sera from 30 patients allergic to grass pollen and antibodies raised against natural grass pollen allergens. In the cases of five representative patients in whom the IgE reactivity

Mapping of cat albumin using monoclonal antibodies: identification of determinants common to cat and dog.

Science.gov (United States)

Boutin, Y; Hébert, J; Vrancken, E R; Mourad, W

1989-01-01

Cat and dog albumins from commercial extracts were used to produce monoclonal antibodies (MoAb). Anti-cat albumin MoAb recognized both cat and dog albumin equally, as did anti-dog albumin MoAb; this confirms cross-reactivity between cat and dog. The MoAb were separated into two groups according to their epitopic specificity; they recognized two overlapping epitopes of cat albumin. Furthermore, by competitive inhibition of radio-allergosorbent test (RAST), it was shown that one MoAb group inhibited significantly the binding of human IgE antibodies (from a pool of 13 patients allergic to both cats and dogs) to insolubilized cat or dog extracts. These observations suggest that murine anti-cat or anti-dog MoAb and human IgE antibodies recognize identical or closely related determinants on cat and dog albumin. Images Fig. 1 Fig. 2 PMID:2478325

Detection of IgE in the sera of rodents: comparison of the applicability of ELISA and RIA

Energy Technology Data Exchange (ETDEWEB)

Reiner, G; Zahner, H [Institut fuer Parasitologie der Justus-Liebig-Universitaet Giessen, Germany, F.R.; Haque, A [Institut Pasteur, 59 - Lille (France). Centre d' Immunologie et de Biologie Parasitaire

1984-04-13

RIA and ELISA were compared for their ability to detect IgE in different rodent species. With a sheep anti-rat IgE antibody good correlation (P < 0.001) between the 2 assay methods for IgE was found in rats. RIA failed to detect the IgE of Mastomys natalensis while ELISA proved to be a suitable test. However, both tests failed to measure IgE in sera of Nile rats.

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

EFFICACY OF COMBINATION TREATMENT WITH ANTI_IGE PLUS SPECIFIC IMMUNOTHERAPY IN PATIENTS WITH ATOPIC DISEASES

Directory of Open Access Journals (Sweden)

N.I. Il'ina

2008-01-01

Full Text Available Allergen specific immunotherapy (ASIT is a very effective technique in treatment of many allergic diseases. It greatly improves the quality of life. There's a risk of adverse system reactions at the time of ASIT. Treatment with anti Ige antibodies (omalizumab, xolair allows decreasing the circulating Ige level and lessening an expression of high affinity fc_r1 receptors on the surface of basophiles and mast cells, inhibition of early and late phase of allergic inflammatory response. Combination of antibige therapy and ASIT can lead to decrease of risk of adverse system reactions.Key words: omalizumab, anti Ige antibodies, allergen specific immunotherapy.

B Cell Intrinsic Mechanisms Constraining IgE Memory

Directory of Open Access Journals (Sweden)

Brice Laffleur

2017-11-01

Full Text Available Memory B cells and long-lived plasma cells are key elements of adaptive humoral immunity. Regardless of the immunoglobulin class produced, these cells can ensure long-lasting protection but also long-lasting immunopathology, thus requiring tight regulation of their generation and survival. Among all antibody classes, this is especially true for IgE, which stands as the most potent, and can trigger dramatic inflammatory reactions even when present in minute amounts. IgE responses and memory crucially protect against parasites and toxic components of venoms, conferring selective advantages and explaining their conservation in all mammalian species despite a parallel broad spectrum of IgE-mediated immunopathology. Long-term memory of sensitization and anaphylactic responses to allergens constitute the dark side of IgE responses, which can trigger multiple acute or chronic pathologic manifestations, some punctuated with life-threatening events. This Janus face of the IgE response and memory, both necessary and potentially dangerous, thus obviously deserves the most elaborated self-control schemes.

Anti-idiotypes against a monoclonal anti-haloperidol antibody bind to dopamine receptor

International Nuclear Information System (INIS)

Elazar, Z.; Kanety, H.; Schreiber, M.; Fuchs, S.

1988-01-01

Anti-idiotypic antibodies were raised in rabbits by immunization with a monoclonal anti-haloperidol antibody. Some of these anti-idiotypic antibodies bind in a concentration dependent manner to bovine striatal membranes. Following affinity purification, these antibodies inhibit haloperidol binding to striatal membranes and deplete [ 3 H]-spiperone binding sites from a solubilized preparation of striatal membranes. It is thus concluded that these anti-idiotypic antibodies are an internal image of haloperidol and as such can interact with D 2 -dopamine receptors

Chimeras of Bet v 1 and Api g 1 reveal heterogeneous IgE responses in patients with birch pollen allergy.

Science.gov (United States)

Gepp, Barbara; Lengger, Nina; Bublin, Merima; Hemmer, Wolfgang; Breiteneder, Heimo; Radauer, Christian

2014-07-01

Characterization of IgE-binding epitopes of allergens and determination of their patient-specific relevance is crucial for the diagnosis and treatment of allergy. We sought to assess the contribution of specific surface areas of the major birch pollen allergen Bet v 1.0101 to binding IgE of individual patients. Four distinct areas of Bet v 1 representing in total 81% of its surface were grafted onto the scaffold of its homolog, Api g 1.0101, to yield the chimeras Api-Bet-1 to Api-Bet-4. The chimeras were expressed in Escherichia coli and purified. IgE binding of 64 sera from Bet v 1-sensitized subjects with birch pollen allergy was determined by using direct ELISA. Specificity was assessed by means of inhibition ELISA. rApi g 1.0101, Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4 bound IgE from 44%, 89%, 80%, 78%, and 48% of the patients, respectively. By comparing the amount of IgE binding to the chimeras and to rApi g 1.0101, 81%, 70%, 75%, and 45% of the patients showed significantly enhanced IgE binding to Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4, respectively. The minority (8%) of the sera revealed enhanced IgE binding exclusively to a single chimera, whereas 31% showed increased IgE binding to all 4 chimeras compared with rApi g 1.0101. The chimeras inhibited up to 70% of IgE binding to rBet v 1.0101, confirming the specific IgE recognition of the grafted regions. The Bet v 1-specific IgE response is polyclonal, and epitopes are spread across the entire Bet v 1 surface. Furthermore, the IgE recognition profile of Bet v 1 is highly patient specific. Copyright © 2014 The Authors. Published by Mosby, Inc. All rights reserved.

Isolation and functional effects of monoclonal antibodies binding to thymidylate synthase.

Science.gov (United States)

Jastreboff, M M; Todd, M B; Malech, H L; Bertino, J R

1985-01-29

Monoclonal antibodies against electrophoretically pure thymidylate synthase from HeLa cells have been produced. Antibodies (M-TS-4 and M-TS-9) from hybridoma clones were shown by enzyme-linked immunoassay to recognize thymidylate synthase from a variety of human cell lines, but they did not bind to thymidylate synthase from mouse cell lines. The strongest binding of antibodies was observed to enzyme from HeLa cells. These two monoclonal antibodies bind simultaneously to different antigenic sites on thymidylate synthase purified from HeLa cells, as reflected by a high additivity index and results of cross-linked radioimmunoassay. Both monoclonal antibodies inhibit the activity of thymidylate synthase from human cell lines. The strongest inhibition was observed with thymidylate synthase from HeLa cells. Monoclonal antibody M-TS-9 (IgM subclass) decreased the rate of binding of [3H]FdUMP to thymidylate synthase in the presence of 5,10-methylenetetrahydrofolate while M-TS-4 (IgG1) did not change the rate of ternary complex formation. These data indicate that the antibodies recognize different epitopes on the enzyme molecule.

An IgE epitope of Bet v 1 and fagales PR10 proteins as defined by a human monoclonal IgE

DEFF Research Database (Denmark)

Hecker, J.; Diethers, A.; Schulz, D.

2012-01-01

-reactivities predicted by primary structure analyses of different isoforms and PR10 proteins were verified by allergen chip-based analyses. CONCLUSIONS: The obtained results demonstrate that hybrid IgE repertoires represent a source for human antibodies with genuine paratopes. The IgE-derived information about the Ig...... generation and epitope delineation of a human monoclonal IgE against the prototypic allergen Bet v 1. METHODS: Phage-display scFv hybrid libraries of allergic donor-derived VH epsilon and synthetic VL were established from 107 mononuclear cells. An obtained scFv was converted into human immunoglobulin...

Increase of lymphocytes with Fc receptors for IgE in patients with allergic rhinitis during the grass pollen season.

OpenAIRE

Spiegelberg, H L; Simon, R A

1981-01-01

Peripheral blood lymphocytes from 10 nonallergic donors and 7 patients suffering from seasonal allergic rhinitis and receiving desensitization therapy were analyzed by rosette assays for Fc receptors for IgE (Fc epsilon R) and IgG (Fc gamma R) before, during and after the grass pollen season. Six of seven patients had moderately elevated IgE levels (330 +/- 268 IU/ml), all had high titers of skin sensitizing antibodies to grass pollens and serum IgE antibodies as measured by radio-allergosorb...

Direct binding of radioiodinated monoclonal antibody to tumor cells: significance of antibody purity and affinity for drug targeting or tumor imaging

International Nuclear Information System (INIS)

Kennel, S.J.; Foote, L.J.; Lankford, P.K.; Johnson, M.; Mitchell, T.; Braslawsky, G.R.

1983-01-01

For MoAb to be used efficiently for drug targeting and tumor imaging, the fraction of antibody binding to tumor cells must be maximized. The authors have studied the binding of 125 I MoAb in three different tumor systems. The fraction of antibody that could be bound to the cell surface was directly proportional to the antibody purity. The affinity constant also limits the fraction of antibody that can bind to cells at a given antigen concentration. Rearrangement of the standard expression for univalent equilibrium binding between two reactants shows that in antigen excess, the maximum fraction of antibody that can bind =Ka[Ag total]/1 + Ka[Ag total]. Binding data using four different MoAb with three cell systems confirm this relationship. Estimates for reasonable concentrations of tumor antigens in vivo indicate that antibodies with binding constants less than 10 8 M -1 are not likely to be useful for drug targeting or tumor imaging

[Analysis of clinical features and allergic status of asthmatic patients with positive serum mycosis-specific IgE].

Science.gov (United States)

Mou, Yan; Ye, Ling; Gong, Ying; Zhang, Zhi-feng; Jin, Mei-ling

2013-08-01

To improve understanding of the clinical characteristics and diagnosis of allergic bronchopulmonary mycosis (ABPM). We retrospectively analyzed the clinical data, including clinical symptoms, laboratory tests, pulmonary function tests and chest CT imaging of 95 asthmatic patients with positive serum mycosis-specific IgE from January 2010 to September 2012 in Zhongshan Hospital Affiliated to Fudan University. Of the 95 patients, 59 cases met the diagnostic criteria of ABPM. There were 34 males and 25 females, with a mean age of (53 ± 4) years and a duration of asthma for (21 ± 4) years. Thirty-six cases showed mycosis hypersensitivity (MH). There were 10 males and 26 females, with a mean age of (46 ± 6) years and a duration of asthma for (16 ± 5) years. Clinical symptoms such as wheeze (52 vs 21, χ(2) = 11.159, P = 0.001), cough (54 vs 27, χ(2) = 4.859, P = 0.030) and expectoration (43 vs 9, χ(2) = 25.731, P = 0.000) were more common in the ABPM group compared to the MH group.In the ABPM group, 58 were A. fumigatus-specific IgE antibody positive, 34 Penicillium-specific IgE antibody positive and 1 only Penicillium-specific IgE antibody positive.While in the MH group, 15 were A.fumigatus-specific IgE antibody positive, 24 Penicillium-specific IgE antibody positive and 17 only Penicillium-specific IgE antibody positive.In the ABPM group, the percentage of positive fumigatus-specific IgE antibody was higher (58 vs 15, χ(2) = 24.500, P = 0.000), while the percentages of dermatophagoides pteronyssinus(21 vs 20, χ(2) = 3.632, P = 0.045) and Dermatophagoides farinae(17 vs 21, χ(2) = 8.118, P = 0.004) were lower. Total serum IgE [(4395 ± 1437) IU/ml vs (276 ± 133) IU/ml, T = 4.384, P = 0.000], peripheral eosinophil percentage[(12.56 ± 1.20)% vs (1.30 ± 0.15)%, t = 8.175, P = 0.000] and count [(2.09 ± 0.43)×10(9)/L vs (0.19 ± 0.04)×10(9)/L, t = 7.032, P = 0.000] were higher in the ABPM group as compared to the MH group.FEV1% slightly declined in the ABPM

Comparison of serum concentrations of environmental allergen-specific IgE in atopic and healthy (nonatopic) horses.

Science.gov (United States)

Wilkołek, P; Sitkowski, W; Szczepanik, M; Adamek, Ł; Pluta, M; Taszkun, I; Gołyński, M; Malinowska, A

2017-12-01

Allergic responses in humans, horses and other species are mediated by immunoglobulin E (IgE) antibodies. Serum testing to detect allergen-specific IgE antibodies has been developed for dogs, cats and horses; this allows for the identification of allergens and determination of appropriate allergen- specific immunotherapies. This study compared serum allergen-specific IgE concentrations in atopic and healthy horses. The study was performed on Malopolski breed atopic (n=21) and nonatopic (n=21) clinically healthy horses. Allergen-specific IgE serum concentrations were measured in summer seasons of 2008-2015 using a monoclonal anti-IgE antibody. A Northern and Central European allergen panel containing mite, insect, mould and plant pollen allergens, including 15 tests of individual allergens and 5 tests of allergen mixtures was used. The mean allergen-specific IgE concentrations in the atopic and normal horse populations were compared. Among the atopic horses, the strongest positive reactions occurred against the storage mites Tyrophagus putrescentiae and the domestic mite Dermatophagoides farinae. The atopic horses also demonstrated high IgE concentrations against insects, particularly Tabanus sp., the plant pollens colza, cultivated rye and the mould pollen mixture Aspergillus/Penicillium. No horses in the atopic group were IgE-negative. Among all mite, insect, mould and some plant allergen groups the differences in mean specific IgE concentrations between allergic and healthy horses were significant. The mean IgE concentrations for most allergen groups were significantly higher in the atopic horses than in the healthy animals. However, a high incidence of positive reactions was observed in both healthy and allergic horses. Our results showed a high frequency of polysensitization in atopic horses. Copyright© by the Polish Academy of Sciences.

A soluble form of the high affinity IgE receptor, Fc-epsilon-RI, circulates in human serum.

Directory of Open Access Journals (Sweden)

Eleonora Dehlink

Full Text Available Soluble IgE receptors are potential in vivo modulators of IgE-mediated immune responses and are thus important for our basic understanding of allergic responses. We here characterize a novel soluble version of the IgE-binding alpha-chain of Fc-epsilon-RI (sFcεRI, the high affinity receptor for IgE. sFcεRI immunoprecipitates as a protein of ∼40 kDa and contains an intact IgE-binding site. In human serum, sFcεRI is found as a soluble free IgE receptor as well as a complex with IgE. Using a newly established ELISA, we show that serum sFcεRI levels correlate with serum IgE in patients with elevated IgE. We also show that serum of individuals with normal IgE levels can be found to contain high levels of sFcεRI. After IgE-antigen-mediated crosslinking of surface FcεRI, we detect sFcεRI in the exosome-depleted, soluble fraction of cell culture supernatants. We further show that sFcεRI can block binding of IgE to FcεRI expressed at the cell surface. In summary, we here describe the alpha-chain of FcεRI as a circulating soluble IgE receptor isoform in human serum.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-09-07

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

A four-step sandwich radioimmunoassay for direct selection of monoclonal antibodies to allergen molecules

International Nuclear Information System (INIS)

Ley, V.; Corbi, A.L.; Sanchez-Madrid, F.; Carreira, J.C.

1985-01-01

A 4-step radioimmunoassay has been devised for direct identification of monoclonal antibodies (MAb) directed to IgE-binding molecules. Polyvinyl chloride wells coated with purified anti-mouse kappa chain MAb (187-1) were successively incubated with: (1) MAb-containing hybridoma supernatants, (2) allergen extract, (3) allergic patients' serum pool, and (4) 125 I-labeled anti-human IgE antiserum, to detect MAb-allergen-IgE complexes. MAb to allergens from Parietaria judaica pollen and Dermatophagoides mites have been selected with this screening procedure. The affinity-purified allergen molecules competed the binding of IgE to allergen extracts coated to paper discs in a RAST inhibition assay, confirming the anti-allergen specificity of the selected MAb. This screening method is sensitive enough to allow detection of MAb directed to poorly represented allergens. (Auth.)

Design of a Heterotetravalent Synthetic Allergen That Reflects Epitope Heterogeneity and IgE Antibody Variability to Study Mast Cell Degranulation

Science.gov (United States)

Handlogten, Michael W.; Kiziltepe, Tanyel; Bilgicer, Basar

2013-01-01

SYNOPSIS This study describes the design of a heterotetravalent allergen (HtTA) as a multi-component experimental system that enables an integrative approach to study mast cell degranulation. The HtTA design allows presentation of two distinct haptens, each with a valency of two, thereby better reflecting the complexity of natural allergens by displaying epitope heterogeneity and IgE antibody variability. Using the HtTA design, synthetic allergens HtTA-1 and HtTA-2 were synthesized to model a combination of epitope/IgE affinities. HtTA-1 presented DNP and dansyl haptens (Kd = 22 and 54 nM for IgEDNP and IgEdansyl respectively), and HtTA-2 presented dansyl and the weak affinity DNP-Pro haptens (Kd = 550 nM for IgEDNP). Both HtTAs effectively induced degranulation when mast cells were primed with both IgEDNP and IgEdansyl antibodies. Interestingly, tetravalent DNP-Pro or bivalent dansyl were insufficient in stimulating a degranulation response, illustrating the significance of valency, affinity, and synergy in allergen-IgE interactions. Importantly, maximum degranulation with both HtTA-1 and HtTA-2 was observed when only 50% of the mast cell-bound IgEs were hapten specific (25% IgEdansyl + 25% IgEDNP). Taken together, this study establishes the HtTA system as a physiologically relevant experimental model and demonstrates its utility in elucidating critical mechanisms of mast cell degranulation. PMID:23050868

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

Monoclonal antibodies that bind the renal Na+/glucose symport system. 1. Identification

International Nuclear Information System (INIS)

Wu, J.S.R.; Lever, J.E.

1987-01-01

Phlorizin is a specific, high-affinity ligand that binds the active site of the Na + /glucose symporter by a Na + -dependent mechanism but is not itself transported across the membrane. The authors have isolated a panel of monoclonal antibodies that influence high-affinity, Na + -dependent phlorizin binding to pig renal brush border membranes. Antibodies were derived after immunization of mice either with highly purified renal brush border membranes or with apical membranes purified from LLC-PK 1 , a cell line of pig renal proximal tubule origin. Antibody 11A3D6, an IgG/sub 2b/, reproducibly stimulated Na + -dependent phlorizin binding whereas antibody 18H10B12, an IgM, strongly inhibited specific binding. These effects were maximal after 30-min incubation and exhibited saturation at increased antibody concentrations. Antibodies did not affect Na + -dependent sugar uptake in vesicles but significantly prevented transport inhibition by bound phlorizin. Antibodies recognized a 75-kDa antigen identified by Western blot analysis of brush border membranes, and a 75-kDa membrane protein could be immunoprecipitated by 18H10B12. These properties, provide compelling evidence that the 75-kDa antigen recognized by these antibodies is a component of the renal Na + /glucose symporter

FcγRII-binding Centyrins mediate agonism and antibody-dependent cellular phagocytosis when fused to an anti-OX40 antibody.

Science.gov (United States)

Zhang, Di; Whitaker, Brian; Derebe, Mehabaw G; Chiu, Mark L

2018-04-01

Immunostimulatory antibodies against the tumor necrosis factor receptors (TNFR) are emerging as promising cancer immunotherapies. The agonism activity of such antibodies depends on crosslinking to Fc gamma RIIB receptor (FcγRIIB) to enable the antibody multimerization that drives TNFR activation. Previously, Fc engineering was used to enhance the binding of such antibodies to Fcγ receptors. Here, we report the identification of Centyrins as alternative scaffold proteins with binding affinities to homologous FcγRIIB and FcγRIIA, but not to other types of Fcγ receptors. One Centyrin, S29, was engineered at distinct positions of an anti-OX40 SF2 antibody to generate bispecific and tetravalent molecules named as mAbtyrins. Regardless of the position of S29 on the SF2 antibody, SF2-S29 mAbtyrins could bind FcγRIIB and FcγRIIA specifically while maintaining binding to OX40 receptors. In a NFκB reporter assay, attachment of S29 Centyrin molecules at the C-termini, but not the N-termini, resulted in SF2 antibodies with increased agonism owing to FcγRIIB crosslinking. The mAbtyrins also showed agonism in T-cell activation assays with immobilized FcγRIIB and FcγRIIA, but this activity was confined to mAbtyrins with S29 specifically at the C-termini of antibody heavy chains. Furthermore, regardless of the position of the molecule, S29 Centyrin could equip an otherwise Fc-silent antibody with antibody-dependent cellular phagocytosis activity without affecting the antibody's intrinsic antibody-dependent cell-meditated cytotoxicity and complement-dependent cytotoxicity. In summary, the appropriate adoption FcγRII-binding Centyrins as functional modules represents a novel strategy to engineer therapeutic antibodies with improved functionalities.

Isotopic and enzymatic IgE assays in non-allergic subjects

International Nuclear Information System (INIS)

Stein, R.; Evans, S.; Milner, R.; Rand, C.; Dolovich, J.

1983-01-01

In order to establish normal values in an adult population for serum IgE concentration, sera were obtaned from 446 ambulatory Canadian caucasian subjects with negative allergy histories. A standard isotopic procedure, the Phadebas paper radioimmunosorbent test (PRIST), was compared with the new enzymatic counterpart, the Phadezyme PRIST. By the isotopic method, serum IgE concentrations in women and men were comparable from one age group to another with no age-related trend in the seven age groups examined (15-20, 21-30, 31-40, 41-50, 51-60, 61-70, above 70). The median and 95th percentile units (U)/ml respectively were 17.5 and 145 for 224 women and 25.5 and 275 for 222 men. Mean values +- 1 SD for women were 43 +- 102 and for men, 58 +- 137. Levels were significantly higher in men as a group. Sera with IgE concentrations above 100 U and a sampling of additional sera were tested for specific IgE antibodies to 13 common allergens by the radioallergosorbent test (RAST). After exclusion of RAST-positive sera, the mean U/ml values +- ISD were 22 +- 29 for 204 women and 37 +- 54 for 196 men. Geometric mean U/ml values for these sera were 14.6 for women and 22.3 for men and the median and 95th percentile U/ml respectively for the women were 15 and 66, for the men, 24 and 135. These 95th percentile values are considered the upper limits of normal in this population. The RAST identifiction of antibodies to allergens to which sensitization was demonstrated provided a potential explanation for serum IgE concentrations above 100 U/ml in less than 30% of the sera in this population with negative allergy histories. The isotopic method and the counterpart enzymatic method (Phadezyme PRIST) were highly comparable; the correlation coefficient (r) for all the sera was +- 0.93(P<0.001). IgE levels were significantly higher in male smokers than non-smokers by both methods but these differences were not significant in women. (author)

IgE - the main player of food allergy

DEFF Research Database (Denmark)

Broekman, Henrike C H; Eiwegger, Thomas; Upton, Julia

2017-01-01

Food allergy is a growing problem worldwide, presently affecting 2-4% of adults and 5-8% of young children. IgE is a key player in food allergy. Consequently huge efforts have been made to develop tests to detect either the presence of IgE molecules, their allergen binding sites...... or their functionality, in order to provide information regarding the patient's food allergy. The ultimate goal is to develop tools that are capable of discriminating between asymptomatic sensitization and a clinically relevant food allergy, and between different allergic phenotypes in an accurate and trustworthy manner...

A study of the prevalence and clinical significance of venom-specific IgE.

Science.gov (United States)

Zora, J A; Swanson, M C; Yunginger, J W

1988-01-01

The prevalence of unrecognized Hymenoptera-venom sensitization, assessed by venom skin tests (VSTs) in adults with no history of adverse reactions to sting, has been as high as 12% in previous epidemiologic studies. To assess further the clinical importance of positive VSTs in such individuals, we skin tested 33 subjects stung in the field during the preceding 12 months without reaction, and 33 persons who denied being stung in the preceding 3 years. Among the recently stung group, 12/33 had at least one positive VST (greater than or equal to 2+) at 1.0 microgram/ml, whereas 5/33 had positive VST at 0.1 microgram/ml. In contrast, only 2/33 nonstung subjects had positive VST at 1.0 microgram/ml, and none were positive at 0.1 microgram/ml. To estimate, prospectively, the sensitization rate after insect stings, we studied a third group of 11 nonsensitive patients with negative skin tests to Hymenoptera. After a deliberate in-hospital honeybee sting, only 1/11 developed a persistently positive honeybee VST. From among the three groups, we then performed nine sting challenges in eight patients with positive VSTs, and all stings were tolerated without significant reaction. We also measured IgE antibodies to Hymenoptera venoms in random blood bank donors. During April to May, 2/216 sera contained elevated venom-specific IgE antibodies, whereas 14/201 sera collected from October to November contained elevated venom-specific IgE antibodies. We conclude that a small but appreciable portion of the population has venom-specific IgE antibodies and that the prevalence is seasonably variable. Our data indicate that persons recently stung without significant reaction contribute to this group but that only a small portion of this group is at risk for a systemic reaction with a future sting.

Effects of altered FcγR binding on antibody pharmacokinetics in cynomolgus monkeys

Science.gov (United States)

Leabman, Maya K; Meng, Y Gloria; Kelley, Robert F; DeForge, Laura E; Cowan, Kyra J; Iyer, Suhasini

2013-01-01

Antibody interactions with Fcγ receptors (FcγRs), like FcγRIIIA, play a critical role in mediating antibody effector functions and thereby contribute significantly to the biologic and therapeutic activity of antibodies. Over the past decade, considerable work has been directed towards production of antibodies with altered binding affinity to FcγRs and evaluation of how the alterations modulate their therapeutic activity. This has been achieved by altering glycosylation status at N297 or by engineering modifications in the crystallizable fragment (Fc) region. While the effects of these modifications on biologic activity and efficacy have been examined, few studies have been conducted to understand their effect on antibody pharmacokinetics (PK). We present here a retrospective analysis in which we characterize the PK of three antibody variants with decreased FcγR binding affinity caused by amino acid substitutions in the Fc region (N297A, N297G, and L234A/L235A) and three antibody variants with increased FcγRIIIA binding affinity caused by afucosylation at N297, and compare their PK to corresponding wild type antibody PK in cynomolgus monkeys. For all antibodies, PK was examined at a dose that was known to be in the linear range. Since production of the N297A and N297G variants in Chinese hamster ovary cells results in aglycosylated antibodies that do not bind to FcγRs, we also examined the effect of expression of an aglycosylated antibody, without sequence change(s), in E. coli. All the variants demonstrated similar PK compared with that of the wild type antibodies, suggesting that, for the six antibodies presented here, altered FcγR binding affinity does not affect PK. PMID:24492343

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

As part of an ongoing effort to develop immunoassays for chelated uranium(VI) on a hand-held flow fluorimeter, an anti-uranium monoclonal antibody designated as 8A11 was fluorescently labeled using two different strategies. When 8A11 was coupled via reactive lysines to either ALEXATM 488 or Cy5TM, the resulting fluorescent antibody conjugate exhibited positive cooperativity in the presence of its antigen, U(VI) chelated with 2,9-dicarboxy-1,10-phenanthroline (U(VI)-DCP). That is, when one of the two binding sites on the covalently modified 8A11 was occupied with bound antigen, the affinity of the remaining site on the antibody for U(VI)-DCP appeared to increase. Unmodified 8A11 bound U(VI)-DCP with the expected hyperbolic dependence on the concentration of antigen, consistent with independent and equal binding of ligand at both sites. Proteolytic cleavage of the fluorescently conjugated 8A11 to produce the fluorescent monovalent Fab fragment yielded an active preparation that now bound U(VI)-DCP with no evidence of positive cooperativity. Although, in principle, any divalent antibody has the potential to exhibit positive cooperativity in its binding interactions with its antigen, very little literature precedent for this type of behavior exists. Native 8A11 was also noncovalently labeled with highly fluorescent ZENONTM reagents. These reagents are fluorescently-labeled Fab fragments of goat anti-mouse antibodies that bind to the Fc portion of 8A11. These high-affinity, monovalent fluorescent reagents permitted the intact 8A11 mouse antibody to be labeled in situ with no covalent modifications. Incubation of the 8A11 with ZENON 647 produced a fluorescent protein complex that showed an 8-fold higher affinity for U(VI)-DCP than did the free 8A11 alone. Again, very few literature precedents exist for this phenomenon, where agents that bind to the Fc portion of an intact antibody change the affinity of the antibody for the antigen at the structurally distant Fab portion

Specific binding of antigen-antibody in physiological environments: Measurement, force characteristics and analysis

Science.gov (United States)

Gu, Xin; Zhou, Jun; Zhou, Lu; Xie, Shusen; Petti, Lucia; Wang, Shaomin; Wang, Fuyan

2018-05-01

The specific recognition of the antigen by the antibody is the crucial step in immunoassays. Measurement and analysis of the specific recognition, including the ways in which it is influenced by external factors are of paramount significance for the quality of the immunoassays. Using prostate-specific antigen (PSA)/anti-PSA antibody and α-fetoprotein (AFP) /anti-AFP antibody as examples, we have proposed a novel solution for measuring the binding forces between the antigens and their corresponding antibodies in different physiological environments by combining laminar flow control technology and optical tweezers technology. On the basis of the experimental results, the different binding forces of PSA/anti-PSA antibody and AFP/anti-AFP antibody in the same phosphate-buffered saline (PBS) environments are analysed by comparing the affinity constant of the two antibodies and the number of antigenic determinants of the two antigens. In different electrolyte environments, the changes of the binding force of antigens-antibodies are explained by the polyelectrolyte effect and hydrophobic interaction. Furthermore, in different pH environments, the changes of binding forces of antigens-antibodies are attributed to the role of the denaturation of protein. The study aims to recognise the antigen-antibody immune mechanism, thus ensuring further understanding of the biological functions of tumour markers, and it promises to be very useful for the clinical diagnosis of early-stage cancer.

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.)

Antibody binding constants from Farr test and other radioimmunoassays. A theoretical and experimental analysis

International Nuclear Information System (INIS)

Engel, J.; Schalch, W.

1980-01-01

For the reaction of monovalently reacting antibody (116-700pIEF) with its antigen (streptococcal group A-variant polysaccharide), an apparent binding constant Ksub(a) was derived by the ammonium sulfate precipitation technique (Farr assay) which was 40 times larger than the true binding constant K = 10 6 M -1 determined by fluorescence titration and equilibrium dialysis. For monovalently reacting antibodies the time needed for re-equilibration of the binding reaction is short as compared to the time of ammonium sulfate incubation. A thermodynamic analysis was therefore performed for the case of complete equilibration of all components in solution and in the ammonium sulfate precipitate. It was found that in this limiting case Ksub(a)/K is equal to the ratio of the solubilities of the antibody and the antibody complex corrected by the activity coefficients of the components in the precipitate. For other antibody-antigen reactions in which the antibody reacts with both binding sites to the same antigen molecule, re-equilibration of the binding reaction in solution is much slower. For such systems a disturbance of the binding reaction by the precipitation is less likely and correct binding constants may be obtained by the Farr technique or other radioimmunoassays involving precipitation. (author)

Mast cells and IgE in defense against venoms: Possible “good side” of allergy?

Directory of Open Access Journals (Sweden)

Stephen J. Galli

2016-01-01

Full Text Available Physicians think of mast cells and IgE primarily in the context of allergic disorders, including fatal anaphylaxis. This ‘bad side’ of mast cells and IgE is so well accepted that it can be difficult to think of them in other contexts, particularly those in which they may have beneficial functions. However, there is evidence that mast cells and IgE, as well as basophils (circulating granulocytes whose functions partially overlap with those of mast cells, can contribute to host defense as components of adaptive type 2 immune responses to helminths, ticks and certain other parasites. Accordingly, allergies often are conceptualized as “misdirected” type 2 immune responses, in which IgE antibodies are produced against any of a diverse group of apparently harmless antigens, as well as against components of animal venoms. Indeed, certain unfortunate patients who have become sensitized to venoms develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. In this review, we will describe evidence that mast cells can enhance innate resistance to reptile or arthropod venoms during a first exposure to such venoms. We also will discuss findings indicating that, in mice which survive an initial encounter with venom, acquired type 2 immune responses, IgE antibodies, the high affinity IgE receptor (FcɛRI, and mast cells can contribute to acquired resistance to the lethal effects of both honeybee venom and Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against venoms and perhaps other noxious substances.

Rifampicin-dependent antibodies bind a similar or identical epitope to glycoprotein IX-specific quinine-dependent antibodies

NARCIS (Netherlands)

Burgess, Janette K.; Lopez, Jose A.; Gaudry, Leonie E.; Chong, Beng H.

2000-01-01

The drug-dependent antibody of a patient with rifampicin-induced thrombocytopenia was characterized using the antigen-capture enzyme-linked immunosorbent assay (MAIPA assay), flow cytometry, and immunoprecipitation. The antibody was found to bind glycoprotein (GP) Ib-IX but not GPIIb-IIIa because

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.

Evidence of a common regulation of IgE and IgG-subclass antibodies in humans during immunotherapy

DEFF Research Database (Denmark)

Søndergaard, I; Poulsen, L K; Osterballe, O

1992-01-01

Based on a 3-year prospective study of 20 pollen-allergic patients, where a detailed analysis of the IgE, IgG1 and IgG4 immune response was performed, we propose that a common regulatory mechanism exists between the IgE and IgG1 synthesis and between IgE and IgG4 synthesis during immunotherapy. I...

Pro j 2 is mesquite profilin: molecular characteristics and specific IgE binding activity.

Science.gov (United States)

Ali-Sadeghi, Hosein; Khodadadi, Ali; Amini, Akram; Assarehzadegan, Mohammad-Ali; Sepahi, Najmeh; Zarinhadideh, Farnoosh

2015-06-01

Pollens from mesquite (Prosopis juliflora) are potent allergen responsible in causing immediate hypersensitivity reactions in susceptible people in tropical countries. This study aimed to clone, express and purify the mesquite pollen profilin (Pro j 2) as well as evaluating its nucleotide sequence homology in order to predict allergenic cross-reactivity with profilins of common allergenic plants. Immunoblotting assay and specific ELISA were applied to determine the immunoreactivity of sera from 35 patients who were allergic to mesquite pollen. The mesquite profilin-coding sequence was cloned into PTZ57R/T vector and amplified. The cDNA of mesquite pollen profilin was then expressed in Escherichia coli using pET-21b (+) vector and puri?ed by one-step Ni2+ a?nity chromatography. IgE binding capacity of the recombinant mesquite profiling (rPro j 2) was analyzed by specific ELISA, immunoblotting, and inhibition assays. cDNA nucleotide sequencing revealed an open reading frame of 399bp encoding for 133 amino acids which belongs to the profilin family. Seventeen patients (17/35, 48.57%) had significant specific IgE level for rPro j 2. Immunodetection and inhibition assays indicated that puri?ed rPro j 2 might be similar as that in the crude extract. Pro j 2, as a new allergen from mesquite pollen, was produced in E. coli with an IgE-reactivity similar to that of its natural counterpart. The amino acid sequences homology analysis of mesquite profilin and several profilin molecules from other plants showed high degree of cross-reactivity among plant-derived profilins from unrelated families.

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.

Serum IgE reactivity profiling in an asthma affected cohort.

Directory of Open Access Journals (Sweden)

Tania Dottorini

Full Text Available BACKGROUND: Epidemiological evidence indicates that atopic asthma correlates with high serum IgE levels though the contribution of allergen specific IgE to the pathogenesis and the severity of the disease is still unclear. METHODS: We developed a microarray immunoassay containing 103 allergens to study the IgE reactivity profiles of 485 asthmatic and 342 non-asthmatic individuals belonging to families whose members have a documented history of asthma and atopy. We employed k-means clustering, to investigate whether a particular IgE reactivity profile correlated with asthma and other atopic conditions such as rhinitis, conjunctivitis and eczema. RESULTS: Both case-control and parent-to-siblings analyses demonstrated that while the presence of specific IgE against individual allergens correlated poorly with pathological conditions, particular reactivity profiles were significantly associated with asthma (p<10E-09. An artificial neural network (ANN-based algorithm, calibrated with the profile reactivity data, correctly classified as asthmatic or non-asthmatic 78% of the individual examined. Multivariate statistical analysis demonstrated that the familiar relationships of the study population did not affect the observed correlations. CONCLUSIONS: These findings indicate that asthma is a higher-order phenomenon related to patterns of IgE reactivity rather than to single antibody reactions. This notion sheds new light on the pathogenesis of the disease and can be readily employed to distinguish asthmatic and non-asthmatic individuals on the basis of their serum reactivity profile.

The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children

Directory of Open Access Journals (Sweden)

Alcântara-Neves Neuza M

2010-08-01

Full Text Available Abstract Background The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders. Objective The aim of this study was to explore the association of Trichuris trichiura and Ascaris lumbricoides infections with wheezing and atopy in early childhood. Study design A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations (Dermatophagoides pteronyssinus, Blomia tropicalis and common child food, as well as against A. lumbricoides antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations. Results Active T. trichiura infection but not A. lumbricoides infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-A. lumbricoides IgE antibodies, but not current A. lumbricoides infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non

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...

Screening of transgenic proteins expressed in transgenic food crops for the presence of short amino acid sequences identical to potential, IgE – binding linear epitopes of allergens

Directory of Open Access Journals (Sweden)

Peijnenburg Ad ACM

2002-12-01

Full Text Available Abstract Background Transgenic proteins expressed by genetically modified food crops are evaluated for their potential allergenic properties prior to marketing, among others by identification of short identical amino acid sequences that occur both in the transgenic protein and allergenic proteins. A strategy is proposed, in which the positive outcomes of the sequence comparison with a minimal length of six amino acids are further screened for the presence of potential linear IgE-epitopes. This double track approach involves the use of literature data on IgE-epitopes and an antigenicity prediction algorithm. Results Thirty-three transgenic proteins have been screened for identities of at least six contiguous amino acids shared with allergenic proteins. Twenty-two transgenic proteins showed positive results of six- or seven-contiguous amino acids length. Only a limited number of identical stretches shared by transgenic proteins (papaya ringspot virus coat protein, acetolactate synthase GH50, and glyphosate oxidoreductase and allergenic proteins could be identified as (part of potential linear epitopes. Conclusion Many transgenic proteins have identical stretches of six or seven amino acids in common with allergenic proteins. Most identical stretches are likely to be false positives. As shown in this study, identical stretches can be further screened for relevance by comparison with linear IgE-binding epitopes described in literature. In the absence of literature data on epitopes, antigenicity prediction by computer aids to select potential antibody binding sites that will need verification of IgE binding by sera binding tests. Finally, the positive outcomes of this approach warrant further clinical testing for potential allergenicity.

IgE- and IgG mediated severe anaphylactic platelet transfusion reaction in a known case of cerebral malaria

Directory of Open Access Journals (Sweden)

B Shanthi

2013-01-01

Full Text Available Background: Allergic reactions occur commonly in transfusion practice. However, severe anaphylactic reactions are rare; anti-IgA (IgA: Immunoglobulin A in IgA-deficient patients is one of the well-illustrated and reported causes for such reactions. However, IgE-mediated hypersensitivity reaction through blood component transfusion may be caused in parasitic hyperimmunization for IgG and IgE antibodies. Case Report: We have evaluated here a severe anaphylactic transfusion reaction retrospectively in an 18year-old male, a known case of cerebral malaria, developed after platelet transfusions. The examination and investigations revealed classical signs and symptoms of anaphylaxis along with a significant rise in the serum IgE antibody level and IgG by hemagglutination method. Initial mild allergic reaction was followed by severe anaphylactic reaction after the second transfusion of platelets. Conclusion: Based on these results, screening of patients and donors with mild allergic reactions to IgE antibodies may help in understanding the pathogenesis as well as in planning for preventive desensitization and measures for safe transfusion.

The antibody response against human and chimeric anti-TNF therapeutic antibodies primarily targets the TNF binding region

NARCIS (Netherlands)

van Schie, K. A.; Hart, M. H.; de Groot, E. R.; Kruithof, S.; Aarden, L. A.; Wolbink, G. J.; Rispens, T.

2015-01-01

In a subset of patients, anti tumour necrosis factor (TNF) therapeutic antibodies are immunogenic, resulting in the formation of antidrug antibodies (ADAs). Neutralising ADAs compete with TNF for its binding site and reduces the effective serum concentration, causing clinical non-response. It is

Complement-mediated bactericidal activity of anti-factor H binding protein monoclonal antibodies against the meningococcus relies upon blocking factor H binding.

Science.gov (United States)

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

2011-09-01

Binding of the complement-downregulating protein factor H (fH) to the surface of the meningococcus is important for survival of the organism in human serum. The meningococcal vaccine candidate factor H binding protein (fHbp) is an important ligand for human fH. While some fHbp-specific monoclonal antibodies (MAbs) block binding of fH to fHbp, the stoichiometry of blocking in the presence of high serum concentrations of fH and its effect on complement-mediated bactericidal activity are unknown. To investigate this question, we constructed chimeric antibodies in which the human IgG1 constant region was paired with three murine fHbp-specific binding domains designated JAR 3, JAR 5, and MAb502. By surface plasmon resonance, the association rates for binding of all three MAbs to immobilized fHbp were >50-fold higher than that for binding of fH to fHbp, and the MAb dissociation rates were >500-fold lower than that for fH. While all three MAbs elicited similar C1q-dependent C4b deposition on live bacteria (classical complement pathway), only those antibodies that inhibited binding of fH to fHbp (JAR 3 and JAR 5) had bactericidal activity with human complement. MAb502, which did not inhibit fH binding, had complement-mediated bactericidal activity only when tested with fH-depleted human complement. When an IgG1 anti-fHbp MAb binds to sparsely exposed fHbp on the bacterial surface, there appears to be insufficient complement activation for bacteriolysis unless fH binding also is inhibited. The ability of fHbp vaccines to elicit protective antibodies, therefore, is likely to be enhanced if the antibody repertoire is of high avidity and includes fH-blocking activity.

A study of the human immune response to Lolium perenne (rye) pollen and its components, Lol p I and Lol p II (rye I and rye II). I. Prevalence of reactivity to the allergens and correlations among skin test, IgE antibody, and IgG antibody data.

Science.gov (United States)

Freidhoff, L R; Ehrlich-Kautzky, E; Grant, J H; Meyers, D A; Marsh, D G

1986-12-01

In a stratified random sample of 320 white adults, the prevalence of puncture skin test positivity (ST +) to Lolium perenne (rye grass)-pollen extract (LPE) was 16%. Fifteen percent of all subjects (or 84% of subjects classified LPE IgE antibody positive [Ab +]) was classified IgE Ab + to highly purified Lol p I (Rye I), and 4% of all subjects (or 26% of subjects classified LPE IgE Ab +) was classified IgE Ab + to highly purified Lol p II (Rye II). These data and similar results obtained in an allergy-enriched group of 361 subjects are consistent with previous studies that Lol I is a major allergen and Lol II is a minor allergen of LPE. Whether we studied LPE, Lol I, or Lol II, responder subjects were younger than nonresponder subjects and more male than female subjects were responders. We then investigated the quantitative interrelationships among ST, IgE, and IgG Ab responsiveness to LPE, Lol I, and Lol II in the allergy-enriched group. For each allergen, log-log correlations were strong and significant for ST versus IgE Ab and for IgE Ab versus IgG Ab. All subjects IgE Ab + to Lol I or Lol II were IgG Ab + to that allergen, supporting other evidence for a commonality in the genetic control influencing the production of IgE and IgG Abs to a given allergen. Log-log correlations among ST end points, IgE Ab levels, or IgG Ab levels were strong for LPE versus either Lol I or Lol II but weak between Lol I and Lol II, consistent with the reported lack of cross-reactivity between Lol I and Lol II. Despite these findings, almost all Lol II + subjects were Lol I + by ST (98%), IgE Ab (91%), and IgG Ab (83%), suggesting that the Ia-restricted immune recognition of both these molecules is at least in part under a common genetic control.

Two Loci on Chromosome 5 Are Associated with Serum IgE Levels in Labrador Retrievers

Science.gov (United States)

Owczarek-Lipska, Marta; Lauber, Béatrice; Molitor, Vivianne; Meury, Sabrina; Kierczak, Marcin; Tengvall, Katarina; Webster, Matthew T.; Jagannathan, Vidhya; Schlotter, Yvette; Willemse, Ton; Hendricks, Anke; Bergvall, Kerstin; Hedhammar, Åke; Andersson, Göran; Lindblad-Toh, Kerstin; Favrot, Claude; Roosje, Petra; Marti, Eliane; Leeb, Tosso

2012-01-01

Crosslinking of immunoglobulin E antibodies (IgE) bound at the surface of mast cells and subsequent mediator release is considered the most important trigger for allergic reactions. Therefore, the genetic control of IgE levels is studied in the context of allergic diseases, such as asthma, atopic rhinitis, or atopic dermatitis (AD). We performed genome-wide association studies in 161 Labrador Retrievers with regard to total and allergen-specific immunoglobulin E (IgE) levels. We identified a genome-wide significant association on CFA 5 with the antigen-specific IgE responsiveness to Acarus siro. We detected a second genome-wide significant association with respect to the antigen-specific IgE responsiveness to Tyrophagus putrescentiae at a different locus on chromosome 5. A. siro and T. putrescentiae both belong to the family Acaridae and represent so-called storage or forage mites. These forage mites are discussed as major allergen sources in canine AD. No obvious candidate gene for the regulation of IgE levels is located under the two association signals. Therefore our studies offer a chance of identifying a novel mechanism controlling the host's IgE response. PMID:22720065

An automated multiplex specific IgE assay system using a photoimmobilized microarray.

Science.gov (United States)

Ito, Yoshihiro; Moritsugu, Nozomi; Matsue, Takahisa; Mitsukoshi, Kiyomi; Ayame, Hirohito; Okochi, Norihiko; Hattori, Hideshi; Tashiro, Hideo; Sato, Sakura; Ebisawa, Motohiro

2012-11-15

An automated microarray diagnostic system for specific IgE using photoimmobilized allergen has been developed. Photoimmobilization is useful for preparing microarrays, where various types of biological components are covalently immobilized on a plate. Because the immobilization is based on a photo-induced radical cross-linking reaction, it does not require specific functional groups on the immobilized components. Here, an aqueous solution of a photoreactive poly(ethylene glycol)-based polymer was spin-coated on a plate, and an aqueous solution of each allergen was microspotted on the coated plate and allowed to dry in air. Finally, the plate was irradiated with an ultraviolet lamp for covalent immobilization. An automated machine using these plates was developed for the assay of antigen-specific IgE. Initially, the patient serum was added to the microarray plate, and after reaction of the microspotted allergen with IgE, the adsorbed IgE was detected by a peroxidase-conjugated anti-IgE-antibody. The chemical luminescence intensity of the substrate decomposed by the peroxidase was automatically detected using a sensitive charge-coupled device camera. All the allergens were immobilized stably using this method, which was used to screen for allergen-specific IgE. The results were comparable with those using conventional specific IgE. Using this system, six different allergen-specific IgE were assayed using 10 μL of serum within a period of 20 min. Copyright © 2012 Elsevier B.V. All rights reserved.

Cord blood IgE. I. IgE screening in 2814 newborn children

DEFF Research Database (Denmark)

Hansen, L G; Høst, A; Halken, S

1992-01-01

Screening of total IgE in 2814 cord blood samples was analysed by Phadebas IgE PRIST in 2 1-year birth cohorts (1983-1984 and 1985-1986) in Denmark (n = 1189 + 1625). 48.6% of the sera contained less IgE than the detection limit 0.1 kU/l. Cord blood IgE values greater than or equal to 0.5 kU/l we...

JSI-124 inhibits IgE production in an IgE B cell line

International Nuclear Information System (INIS)

Cui, Lulu; Bi, Jiacheng; Yan, Dehong; Ye, Xiufeng; Zheng, Mingxing; Yu, Guang; Wan, Xiaochun

2017-01-01

IgE is a key effector molecule in atopic diseases; however, the regulation mechanisms of IgE production in IgE B cells remain poorly understood. In the present study, we demonstrate that JSI-124 (cucurbitacin I), a selective STAT3 inhibitor, selectively inhibits production of IgE by a human IgE B cell line, CRL-8033 cells, while does not affect the IgG production by IgG B cell lines. In the aspect of molecular mechanism, we found that Igλ, but not Ighe, gene expression was suppressed by JSI-124. The above effects of JSI-124 were not mediated by affecting cellular proliferation or apoptosis. Furthermore, multiple B cell differentiation-related genes expression was not significantly affected by JSI-124. Taken together, we demonstrate a potential strategy of therapeutically suppressing IgE production without affecting IgG production in atopic patients. - Highlights: • JSI-124 inhibits IgE production in an IgE B cell line, CRL-8033 cells. • JSI-124 does not affect IgG production by IgG B cell lines. • JSI-124 inhibits IgE production mainly by suppressing transcription of Igλ.

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.

Total and allergen-specific IgE levels during and after pregnancy in relation to maternal allergy.

Science.gov (United States)

Sandberg, Martina; Frykman, Anne; Jonsson, Yvonne; Persson, Marie; Ernerudh, Jan; Berg, Göran; Matthiesen, Leif; Ekerfelt, Christina; Jenmalm, Maria C

2009-07-01

Type 2 T-helper cell (Th2)-skewed immunity is associated with successful pregnancy and the ability to easily direct immune responses to a Th2-polarised profile may be an evolutionary benefit. The Th2-like immunity associated with allergic disease might generate favourable effects for the maintenance of pregnancy, but could also promote development of Th2-like immune responses and allergic disease in the offspring. The aim of this study was to explore, by using IgE as a stable proxy for Th2, the Th1/Th2 balance in allergic and non-allergic women by measuring allergen-specific and total IgE antibody levels in plasma during pregnancy and after delivery. Specific and total IgE antibody levels were determined by ImmunoCAP technology at five occasions during pregnancy (gestational weeks 10-12, 15-16, 25, 35 and 39), as well as at 2 and 12 months after delivery. Thirty-six women without and 20 women with allergic symptoms were included, of whom 13 were sensitised with allergic symptoms and 30 were non-sensitised without allergic symptoms. The levels of total IgE, but not allergen-specific IgE, were increased during early pregnancy when compared to 12 months after delivery in the sensitised women with allergic symptoms, but not in the non-sensitised women without allergic symptoms (ppregnancy only in the sensitised women with allergic symptoms indicates that allergy is associated with an enhanced Th2 deviation during pregnancy.

NASA-IGES Translator and Viewer

Science.gov (United States)

Chou, Jin J.; Logan, Michael A.

1995-01-01

NASA-IGES Translator (NIGEStranslator) is a batch program that translates a general IGES (Initial Graphics Exchange Specification) file to a NASA-IGES-Nurbs-Only (NINO) file. IGES is the most popular geometry exchange standard among Computer Aided Geometric Design (CAD) systems. NINO format is a subset of IGES, implementing the simple and yet the most popular NURBS (Non-Uniform Rational B-Splines) representation. NIGEStranslator converts a complex IGES file to the simpler NINO file to simplify the tasks of CFD grid generation for models in CAD format. The NASA-IGES Viewer (NIGESview) is an Open-Inventor-based, highly interactive viewer/ editor for NINO files. Geometry in the IGES files can be viewed, copied, transformed, deleted, and inquired. Users can use NIGEStranslator to translate IGES files from CAD systems to NINO files. The geometry then can be examined with NIGESview. Extraneous geometries can be interactively removed, and the cleaned model can be written to an IGES file, ready to be used in grid generation.

Suppression of immune response to Lol pI by administration of idiotype.

Science.gov (United States)

Boutin, Y; Hébert, J

1995-03-01

Allergic diseases are characterized by an increased production of specific IgE antibodies. Suppression of IgE antibody production may be accomplished through idiotypic manipulation. Using an animal model, we explored the effects of anti-Lol pI monoclonal antibody administration on the subsequent IgE and IgG antibody response against Lol pI. Mice were treated with an anti-Lol pI monoclonal antibody (290A-167), which resulted in the production of anti-idiotypic antibodies as evidenced by their ability to bind to the Fab fraction of 290A-167 and to inhibit the binding of rabbit polyclonal anti-idiotypic antibodies to 290A-167. The animals were then immunized with Lol pI adsorbed onto alum, and the immune response to the protein was analyzed. Antigen-specific IgG1 and IgE responses were strongly suppressed as determined by immunoassay. Suppression of anti-Lol pI IgE antibodies was confirmed by a reduction of end-point titers measured by passive cutaneous anaphylaxis. The suppression of antigen-specific antibody was accompanied by a reduction of anti-Lol pI antibody-producing spleen cells. These data indicate that pretreatment with 290A-167 can strongly downregulate the IgE response to the main allergen of ryegrass pollen, which is associated with an increase in anti-idiotypic antibodies. This approach could provide rapid, long-term hyposensitization in patients with grass pollen allergy.

Different mechanisms are involved in the antibody mediated inhibition of ligand binding to the urokinase receptor

DEFF Research Database (Denmark)

List, K; Høyer-Hansen, G; Rønne, E

1999-01-01

Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance or interfer......Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance......) can be employed as a highly useful tool to characterize the inhibitory mechanism of specific antagonist antibodies. Two inhibitory antibodies against uPAR, mAb R3 and mAb R5, were shown to exhibit competitive and non-competitive inhibition, respectively, of ligand binding to the receptor. The former...

Distance between two binding sites of the same antibody molecule

International Nuclear Information System (INIS)

Cser, L.; Gladkikh, I.A.; Ostanevich, Y.M.; Franek, F.; Novotny, J.; Nezlin, R.S.

1978-01-01

Neutron small-angle scattering experiments are reported, aimed at determining the distance between the two binding sites of the same antibody molecule employing complexes of anti-Dnp antibody with an antigenically univalent, high molecular weight ligand. Although the distance values could be determined only with a large statistical error, the data allowed the conclusion that the geometrical parameters of the complexes formed with the early (i.e., precipitating) antibody are significantly different from those of the complexes formed with the late (i.e, non-precipitating) antibody. The data suggest that the precipitating antibody complexed with a high molecular weight antigen assumes an extended shape with an antigen to antigen distance of 35.8 +- 1.3 nm. (Auth.)

An Engineered Disulfide Bond Reversibly Traps the IgE-Fc_3-4 in a Closed, Nonreceptor Binding Conformation

Energy Technology Data Exchange (ETDEWEB)

Wurzburg, Beth A.; Kim, Beomkyu; Tarchevskaya, Svetlana S.; Eggel, Alexander; Vogel, Monique; Jardetzky, Theodore S. [Bern; (Stanford-MED)

2013-08-02

IgE antibodies interact with the high affinity IgE Fc receptor, FcϵRI, and activate inflammatory pathways associated with the allergic response. The IgE-Fc region, comprising the C-terminal domains of the IgE heavy chain, binds FcϵRI and can adopt different conformations ranging from a closed form incompatible with receptor binding to an open, receptor-bound state. A number of intermediate states are also observed in different IgE-Fc crystal forms. To further explore this apparent IgE-Fc conformational flexibility and to potentially trap a closed, inactive state, we generated a series of disulfide bond mutants. Here we describe the structure and biochemical properties of an IgE-Fc mutant that is trapped in the closed, non-receptor binding state via an engineered disulfide at residue 335 (Cys-335). Reduction of the disulfide at Cys-335 restores the ability of IgE-Fc to bind to its high affinity receptor, FcϵRIα. The structure of the Cys-335 mutant shows that its conformation is within the range of previously observed, closed form IgE-Fc structures and that it retains the hydrophobic pocket found in the hinge region of the closed conformation. Locking the IgE-Fc into the closed state with the Cys-335 mutation does not affect binding of two other IgE-Fc ligands, omalizumab and DARPin E2_79, demonstrating selective blocking of the high affinity receptor binding.

Heparin-independent, PF4-dependent binding of HIT antibodies to platelets: implications for HIT pathogenesis.

Science.gov (United States)

Padmanabhan, Anand; Jones, Curtis G; Bougie, Daniel W; Curtis, Brian R; McFarland, Janice G; Wang, Demin; Aster, Richard H

2015-01-01

Antibodies specific for platelet factor 4 (PF4)/heparin complexes are the hallmark of heparin-induced thrombocytopenia and thrombosis (HIT), but many antibody-positive patients have normal platelet counts. The basis for this is not fully understood, but it is believed that antibodies testing positive in the serotonin release assay (SRA) are the most likely to cause disease. We addressed this issue by characterizing PF4-dependent binding of HIT antibodies to intact platelets and found that most antibodies testing positive in the SRA, but none of those testing negative, bind to and activate platelets when PF4 is present without any requirement for heparin (P HIT antibodies recognize PF4 in a complex with heparin, only a subset of these antibodies recognize more subtle epitopes induced in PF4 when it binds to CS, the major platelet glycosaminoglycan. Antibodies having this property could explain "delayed HIT" seen in some individuals after discontinuation of heparin and the high risk for thrombosis that persists for weeks in patients recovered from HIT. © 2015 by The American Society of Hematology.

A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix

OpenAIRE

Hui Liang; Xiaoran Li; Bin Wang; Bing Chen; Yannan Zhao; Jie Sun; Yan Zhuang; Jiajia Shi; He Shen; Zhijun Zhang; Jianwu Dai

2016-01-01

Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of ...

Efficacy and safety of omalizumab in patients with chronic urticaria who exhibit IgE against thyroperoxidase

DEFF Research Database (Denmark)

Maurer, Marcus; Altrichter, Sabine; Bieber, Thomas

2011-01-01

BACKGROUND: A subgroup of patients with chronic spontaneous urticaria (CU) exhibits IgE antibodies directed against autoantigens, such as thyroperoxidase (TPO). We conducted this study to investigate whether such patients with CU with IgE against TPO benefit from treatment with omalizumab......, a humanized anti-IgE mAb licensed for the treatment of severe persistent allergic (IgE-mediated) asthma. OBJECTIVES: We sought to assess the efficacy of omalizumab treatment in patients with CU with IgE autoantibodies against TPO. METHODS: In this multicenter, randomized, double-blind, placebo......-controlled study patients with CU (male/female, 18-70 years of age) with IgE autoantibodies against TPO who had persistent symptoms (wheals and pruritus) despite standard antihistamine therapy were randomized to receive either omalizumab (75-375 mg, dose determined by using the approved asthma dosing table...

Many Routes to an Antibody Heavy-Chain CDR3: Necessary, Yet Insufficient, for Specific Binding

Science.gov (United States)

D’Angelo, Sara; Ferrara, Fortunato; Naranjo, Leslie; Erasmus, M. Frank; Hraber, Peter; Bradbury, Andrew R. M.

2018-01-01

Because of its great potential for diversity, the immunoglobulin heavy-chain complementarity-determining region 3 (HCDR3) is taken as an antibody molecule’s most important component in conferring binding activity and specificity. For this reason, HCDR3s have been used as unique identifiers to investigate adaptive immune responses in vivo and to characterize in vitro selection outputs where display systems were employed. Here, we show that many different HCDR3s can be identified within a target-specific antibody population after in vitro selection. For each identified HCDR3, a number of different antibodies bearing differences elsewhere can be found. In such selected populations, all antibodies with the same HCDR3 recognize the target, albeit at different affinities. In contrast, within unselected populations, the majority of antibodies with the same HCDR3 sequence do not bind the target. In one HCDR3 examined in depth, all target-specific antibodies were derived from the same VDJ rearrangement, while non-binding antibodies with the same HCDR3 were derived from many different V and D gene rearrangements. Careful examination of previously published in vivo datasets reveals that HCDR3s shared between, and within, different individuals can also originate from rearrangements of different V and D genes, with up to 26 different rearrangements yielding the same identical HCDR3 sequence. On the basis of these observations, we conclude that the same HCDR3 can be generated by many different rearrangements, but that specific target binding is an outcome of unique rearrangements and VL pairing: the HCDR3 is necessary, albeit insufficient, for specific antibody binding. PMID:29568296

Monoclonal antibody to the rat glucocorticoid receptor. Relationship between the immunoreactive and DNA-binding domain

International Nuclear Information System (INIS)

Eisen, L.P.; Reichman, M.E.; Thompson, E.B.; Gametchu, B.; Harrison, R.W.; Eisen, H.J.

1985-01-01

The region of the glucocorticoid receptor that reacted with a monoclonal antibody (BUGR-1) was identified. In order to identify the immunoreactive region, the rat liver glucocorticoid receptor was subjected to limited proteolysis; immunoreactive fragments were identified by Western blotting. The monoclonal antibody reacted with both the undigested Mr approximately 97,000 receptor subunit and a Mr approximately 45,000 fragment containing the steroid-binding and DNA-binding domains. Digestion by trypsin also produced two steroid-binding fragments of Mr approximately 27,000 and 31,000 which did not react with the antibody and an immunoreactive Mr approximately 16,000 fragment. This Mr approximately 16,000 fragment was shown to bind to DNA-cellulose, indicating that it contained a DNA-binding domain of the receptor. The undigested receptor must have steroid associated with it to undergo activation to a DNA-binding form. However, the Mr approximately 16,000 immunoreactive fragment binds to DNA-cellulose even if it is obtained by digestion of the steroid-free holoreceptor which does not itself bind to DNA

Blocking antibodies induced by immunization with a hypoallergenic parvalbumin mutant reduce allergic symptoms in a mouse model of fish allergy.

Science.gov (United States)

Freidl, Raphaela; Gstoettner, Antonia; Baranyi, Ulrike; Swoboda, Ines; Stolz, Frank; Focke-Tejkl, Margarete; Wekerle, Thomas; van Ree, Ronald; Valenta, Rudolf; Linhart, Birgit

2017-06-01

Fish is a frequent elicitor of severe IgE-mediated allergic reactions. Beside avoidance, there is currently no allergen-specific therapy available. Hypoallergenic variants of the major fish allergen, parvalbumin, for specific immunotherapy based on mutation of the 2 calcium-binding sites have been developed. This study sought to establish a mouse model of fish allergy resembling human disease and to investigate whether mouse and rabbit IgG antibodies induced by immunization with a hypoallergenic mutant of the major carp allergen protect against allergic symptoms in sensitized mice. C3H/HeJ mice were sensitized with recombinant wildtype Cyp c 1 or carp extract by intragastric gavage. Antibody, cellular immune responses, and epitope specificity in sensitized mice were investigated by ELISA, rat basophil leukemia assay, T-cell proliferation experiments using recombinant wildtype Cyp c 1, and overlapping peptides spanning the Cyp c 1 sequence. Anti-hypoallergenic Cyp c 1 mutant mouse and rabbit sera were tested for their ability to inhibit IgE recognition of Cyp c 1, Cyp c 1-specific basophil degranulation, and Cyp c 1-induced allergic symptoms in the mouse model. A mouse model of fish allergy mimicking human disease regarding IgE epitope recognition and symptoms as close as possible was established. Administration of antisera generated in mice and rabbits by immunization with a hypoallergenic Cyp c 1 mutant inhibited IgE binding to Cyp c 1, Cyp c 1-induced basophil degranulation, and allergic symptoms caused by allergen challenge in sensitized mice. Antibodies induced by immunization with a hypoallergenic Cyp c 1 mutant protect against allergic reactions in a murine model of fish allergy. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Anti-Hemagglutinin Antibody Derived Lead Peptides for Inhibitors of Influenza Virus Binding.

Directory of Open Access Journals (Sweden)

Henry Memczak

Full Text Available Antibodies against spike proteins of influenza are used as a tool for characterization of viruses and therapeutic approaches. However, development, production and quality control of antibodies is expensive and time consuming. To circumvent these difficulties, three peptides were derived from complementarity determining regions of an antibody heavy chain against influenza A spike glycoprotein. Their binding properties were studied experimentally, and by molecular dynamics simulations. Two peptide candidates showed binding to influenza A/Aichi/2/68 H3N2. One of them, termed PeB, with the highest affinity prevented binding to and infection of target cells in the micromolar region without any cytotoxic effect. PeB matches best the conserved receptor binding site of hemagglutinin. PeB bound also to other medical relevant influenza strains, such as human-pathogenic A/California/7/2009 H1N1, and avian-pathogenic A/Mute Swan/Rostock/R901/2006 H7N1. Strategies to improve the affinity and to adapt specificity are discussed and exemplified by a double amino acid substituted peptide, obtained by substitutional analysis. The peptides and their derivatives are of great potential for drug development as well as biosensing.

Binding of monoclonal antibody to protein antigen in fluid phase or bound to solid supports

Energy Technology Data Exchange (ETDEWEB)

Kennel, S J

1982-01-01

Rat monoclonal antibody (MoAb) to fragment D (FgD) of human fibrinogen was used to characterize the direct binding of antibody to protein in solution or bound to solid supports. Purified IgG, F(ab')/sub 2/ and Fab' were prepared from ascites fluid of hybridoma 104-14B which is a fusion product of spleen cells from a rat immunized with FgD and the mouse myeloma cell line, P3-X63-Ag8. Two-dimensional electrophoresis of radioiodinated antibody preparations demonstrated the presence of hybrid immunoglobulin molecules, but only structures having rat heavy and rat light chains had active antibody combinig sites. The affinity constant for IgG as well as F(ab')/sub 2/ and Fab', 6x10/sup 9/ M/sup -1/, was identical when tested using fluid phase antigen (/sup 125/I-labeled FgD). Affinity constants determined for direct binding of iodinated IgG using FgD immobilized on solid supports showed a slight dependence on the antigen concentration used in the measurement. These values ranged from 0.5x10/sup 9/ M/sup -1/ at high antigen concentrations (1.3x10/sup -7/ M) to 9x10/sup 9/ M/sup -1/ at low antigen concentration (1.3x10/sup -10/ M). Binding constants for F(ab')/sub 2/ and Fab' gave similar results indicating that binding was homogeneous and univalent. The capacity of solid state antigen to bind antibody varied with the method used to bind FgD to the solid support. FgD bound directly to polystyrene plates was least efficient at binding labeled antibody; FgD bound to plates through intermediate carriers poly(L-lysine) was only slightly more efficient, while antigen bound to Sepharose beads by cyanogen bromide activation was the most active.

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.

Resource Allocation and Time Utilization in IGE and Non-IGE Schools. Technical Paper No. 410.

Science.gov (United States)

Rossmiller, Richard A.; Geske, Terry G.

This study addressed two basic questions; (1) Do individually guided education (IGE) schools cost more or exhibit different expenditure patterns than non-IGE schools? (2) Do instructional personnel in IGE schools allocate their time differently than instructional personnel in non-IGE schools? Data were obtained from a random sample of 41 IGE…

HYDROXYCHLOROQUINE REDUCES BINDING OF ANTIPHOSPHOLIPID ANTIBODIES TO SYNCYTIOTROPHOBLASTS AND RESTORES ANNEXIN A5 EXPRESSION

Science.gov (United States)

Wu, Xiao-Xuan; Guller, Seth; Rand, Jacob H.

2011-01-01

Objectives Antibody-mediated disruption of the annexin A5 (AnxA5) anticoagulant shield has been posited to be a thrombogenic mechanism in the antiphospholipid syndrome. We recently showed that the antimalarial drug, hydroxychloroquine, dissociates antiphospholipid immune complexes and restores AnxA5 binding to planar phospholipid bilayer. Using quantitative immunoassays, we demonstrated similar effects on BeWo trophoblasts. We therefore investigated the effects of the drug on localization of AnxA5 in primary cultures of human placental syncytiotrophoblasts (SCTs). Study Laser confocal microscopy with computer-based morphometric analysis was used to localize AnxA5 and antiphospholipid antibodies on SCTs exposed to polyclonal and monoclonal antiphospholipid and control IgGs. Results Hydroxychloroquine reversed the effects of the antiphospholipid antibodies on the SCTs by markedly reducing IgG binding and restoring AnxA5 expression. Conclusions These results provide the first morphologic evidence for this effect of hydroxychloroquine on human placental SCTs and support the possibility of novel treatments that target antiphospholipid antibody binding. PMID:21871597

A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix.

Science.gov (United States)

Liang, Hui; Li, Xiaoran; Wang, Bin; Chen, Bing; Zhao, Yannan; Sun, Jie; Zhuang, Yan; Shi, Jiajia; Shen, He; Zhang, Zhijun; Dai, Jianwu

2016-02-17

Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of cetuximab was fused with CBD (CBD-Fab) and expressed in Pichia pastoris. CBD-Fab maintained antigen binding and anti-tumor activity of cetuximab and obtained a collagen-binding ability in vitro. The results also showed CBD-Fab was mainly enriched in tumors and had longer retention time in tumors in A431 s.c. xenografts. Furthermore, CBD-Fab showed a similar therapeutic efficacy as cetuximab in A431 xenografts. Although CBD-Fab hasn't showed better therapeutic effects than cetuximab, its smaller molecular and special target may be applicable as antibody-drug conjugates (ADC) or immunotoxins.

Agonistic Human Antibodies Binding to Lecithin-Cholesterol Acyltransferase Modulate High Density Lipoprotein Metabolism*

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Gunawardane, Ruwanthi N.; Fordstrom, Preston; Piper, Derek E.; Masterman, Stephanie; Siu, Sophia; Liu, Dongming; Brown, Mike; Lu, Mei; Tang, Jie; Zhang, Richard; Cheng, Janet; Gates, Andrew; Meininger, David; Chan, Joyce; Carlson, Tim; Walker, Nigel; Schwarz, Margrit; Delaney, John; Zhou, Mingyue

2016-01-01

Drug discovery opportunities where loss-of-function alleles of a target gene link to a disease-relevant phenotype often require an agonism approach to up-regulate or re-establish the activity of the target gene. Antibody therapy is increasingly recognized as a favored drug modality due to multiple desirable pharmacological properties. However, agonistic antibodies that enhance the activities of the target enzymes are rarely developed because the discovery of agonistic antibodies remains elusive. Here we report an innovative scheme of discovery and characterization of human antibodies capable of binding to and agonizing a circulating enzyme lecithin cholesterol acyltransferase (LCAT). Utilizing a modified human LCAT protein with enhanced enzymatic activity as an immunogen, we generated fully human monoclonal antibodies using the XenoMouseTM platform. One of the resultant agonistic antibodies, 27C3, binds to and substantially enhances the activity of LCAT from humans and cynomolgus macaques. X-ray crystallographic analysis of the 2.45 Å LCAT-27C3 complex shows that 27C3 binding does not induce notable structural changes in LCAT. A single administration of 27C3 to cynomolgus monkeys led to a rapid increase of plasma LCAT enzymatic activity and a 35% increase of the high density lipoprotein cholesterol that was observed up to 32 days after 27C3 administration. Thus, this novel scheme of immunization in conjunction with high throughput screening may represent an effective strategy for discovering agonistic antibodies against other enzyme targets. 27C3 and other agonistic human anti-human LCAT monoclonal antibodies described herein hold potential for therapeutic development for the treatment of dyslipidemia and cardiovascular disease. PMID:26644477

GENERALIZED ANALYSIS OF MONOCLONAL ANTIBODIES TO IGE IN THE TREATMENT OF BRONCHIAL ASTHMA IN CHILDREN IN RUSSIAN FEDERATION

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T.V. Kulichenko

2011-01-01

Full Text Available The article presents a generalized 2-year Russian experience in the application of monoclonal antibodies to IgE in children and adolescents with severe, resistant to standard treatment of bronchial asthma. Data on 65 patients treated with anti-IgE therapy with omalizumab within more than 6 months period in 6 centers of the Russian Federation from 2007 to 2010 were analyzed. The results of this analysis demonstrate the safety and high clinical effectiveness of anti-IgE-therapy in children and adolescents with severe uncontrolled atopic bronchial asthma. Full control of the disease or marked improvement can be achieved in 73% patients, the effect in most cases significantly increases during the first 6 months of treatment and becomes stable in the future, providing a good quality of life and normal lung function.Key words: bronchial asthma, anti-IgE-therapy, treatment, adolescents, children, quality of life, omalizumab.

A Cherry Seed-Derived Spice, Mahleb, is Recognized by Anti-Almond Antibodies Including Almond-Allergic Patient IgE.

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Noble, Kyle A; Liu, Changqi; Sathe, Shridhar K; Roux, Kenneth H

2017-08-01

There are a number of examples of immunologic cross-reactivity elicited by pollens, fruits, seeds, and nuts of closely related plant species. Such cross-reactivity is of particular concern for patients with food allergies. In this report, we investigated a spice (mahleb) that is prepared from the kernel of the St. Lucie cherry, Prunus mahaleb, for cross-reactivity with almond (Prunus dulcis), using enzyme-linked immunosorbent assay (ELISA) and Western blot. Almond and mahleb are members of the same genus. Cross-reactivity between the mahleb and almond was demonstrated by reaction of cherry and almond kernel protein extracts with antibodies raised against almond proteins. Almond-specific murine monoclonal IgG, rabbit polyclonal IgG, and almond-allergic serum IgE each exhibited cross-reactivity with cherry kernel protein. Because of the demonstrated cross-reactivity between almond and mahleb, these findings should be of special concern to almond-allergic patients and attending medical personnel. © 2017 Institute of Food Technologists®.

Binding induced conformational changes of proteins correlate with their intrinsic fluctuations: a case study of antibodies

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Keskin Ozlem

2007-05-01

Full Text Available Abstract Background How antibodies recognize and bind to antigens can not be totally explained by rigid shape and electrostatic complimentarity models. Alternatively, pre-existing equilibrium hypothesis states that the native state of an antibody is not defined by a single rigid conformation but instead with an ensemble of similar conformations that co-exist at equilibrium. Antigens bind to one of the preferred conformations making this conformation more abundant shifting the equilibrium. Results Here, two antibodies, a germline antibody of 36–65 Fab and a monoclonal antibody, SPE7 are studied in detail to elucidate the mechanism of antibody-antigen recognition and to understand how a single antibody recognizes different antigens. An elastic network model, Anisotropic Network Model (ANM is used in the calculations. Pre-existing equilibrium is not restricted to apply to antibodies. Intrinsic fluctuations of eight proteins, from different classes of proteins, such as enzymes, binding and transport proteins are investigated to test the suitability of the method. The intrinsic fluctuations are compared with the experimentally observed ligand induced conformational changes of these proteins. The results show that the intrinsic fluctuations obtained by theoretical methods correlate with structural changes observed when a ligand is bound to the protein. The decomposition of the total fluctuations serves to identify the different individual modes of motion, ranging from the most cooperative ones involving the overall structure, to the most localized ones. Conclusion Results suggest that the pre-equilibrium concept holds for antibodies and the promiscuity of antibodies can also be explained this hypothesis: a limited number of conformational states driven by intrinsic motions of an antibody might be adequate to bind to different antigens.

Binding of HIV-1 gp41-directed neutralizing and non-neutralizing fragment antibody binding domain (Fab and single chain variable fragment (ScFv antibodies to the ectodomain of gp41 in the pre-hairpin and six-helix bundle conformations.

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John M Louis

Full Text Available We previously reported a series of antibodies, in fragment antigen binding domain (Fab formats, selected from a human non-immune phage library, directed against the internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41. Broadly neutralizing antibodies from that series bind to both the fully exposed N-HR trimer, representing the pre-hairpin intermediate state of gp41, and to partially-exposed N-HR helices within the context of the gp41 six-helix bundle. While the affinities of the Fabs for pre-hairpin intermediate mimetics vary by only 2 to 20-fold between neutralizing and non-neutralizing antibodies, differences in inhibition of viral entry exceed three orders of magnitude. Here we compare the binding of neutralizing (8066 and non-neutralizing (8062 antibodies, differing in only four positions within the CDR-H2 binding loop, in Fab and single chain variable fragment (ScFv formats, to several pre-hairpin intermediate and six-helix bundle constructs of gp41. Residues 56 and 58 of the mini-antibodies are shown to be crucial for neutralization activity. There is a large differential (≥ 150-fold in binding affinity between neutralizing and non-neutralizing antibodies to the six-helix bundle of gp41 and binding to the six-helix bundle does not involve displacement of the outer C-terminal helices of the bundle. The binding stoichiometry is one six-helix bundle to one Fab or three ScFvs. We postulate that neutralization by the 8066 antibody is achieved by binding to a continuum of states along the fusion pathway from the pre-hairpin intermediate all the way to the formation of the six-helix bundle, but prior to irreversible fusion between viral and cellular membranes.

A radioisotope dilution assay for unlabelled vitamin B12-intrinsic factor complex employing the binding intrinsic factor antibody: probable evidence for two types of binding antibody

International Nuclear Information System (INIS)

Jacob, E.; O'Brien, H.A.W.; Mollin, D.L.

1977-01-01

A new radioisotope dilution assay for vitamin B 12 -intrinsic factor complex is described. The method is based on the use of the binding type intrinsic antibody (the binding reagent), which when combined with the intrinsic factor-vitamin B 12 complex (labelled ligand), is quantitatively adsorbed onto zirconium phosphate gel pH 6.25. The new assay has been shown to provide a measure of intrinsic factor comparable with other intrinsic factor assays, but it has the important advantage of being able to measure the unlabelled vitamin B 12 -intrinsic factor complex (unlabelled ligand), and will, therefore, be valuable in the study of physiological events in the gastrointestinal tract. During the study, it was found that there is some evidence for at least two types of binding intrinsic factor antibody: One which combines preferentially with the intrinsic factor-vitamin B 12 complex and one which combines equally well with this complex or with free intrinsic factor. (author)

Effect of Pulsed Ultraviolet Light and High Hydrostatic Pressure on the Antigenicity of Almond Protein Extracts.

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The efficacy of pulsed ultraviolet light (PUV) and high hydrostatic pressure (HHP) on reducing the IgE binding to the almond extracts, was studied using SDS-PAGE, Western Blot, and ELISA probed with human plasma containing IgE antibodies to almond allergens, and a polyclonal antibody against almond ...

Targeting IgE in Severe Atopic Dermatitis with a Combination of Immunoadsorption and Omalizumab

DEFF Research Database (Denmark)

Zink, Alexander; Gensbaur, Anna; Zirbs, Michael

2015-01-01

immunoadsorption and anti-IgE antibody omalizumab in 10 patients with severe, therapy-refractory AD. IgE levels decreased after immunoadsorption and decreased continuously in all patients during anti-IgE therapy. The reverse trend was observed during 6 months follow-up without treatment. In parallel...

Specific binding of large aggregates of amphiphilic molecules to the respective antibodies.

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Nabok, Alexei; Tsargorodskaya, Anna; Holloway, Alan; Starodub, Nikolay F; Demchenko, Anna

2007-07-31

The Binding of nonylphenol to respective antibodies immobilized on solid substrates was studied with the methods of total internal reflection ellipsometry (TIRE) and QCM (quartz crystal microbalance) impedance spectroscopy. The binding reaction was proved to be highly specific having an association constant of KA=1.6x10(6) mol(-1) L and resulted in an increase in both the adsorbed layer thickness of 23 nm and the added mass of 18.3 microg/cm2 at saturation. The obtained responses of both TIRE and QCM methods are substantially higher than anticipated for the immune binding of single molecules of nonylphenol. The mechanism of binding of large aggregates of nonylphenol was suggested instead. Modeling of the micelle of amphiphilic nonylphenol molecules in aqueous solutions yielded a micelle size of about 38 nm. The mechanism of binding of large molecular aggregates to respective antibodies can be extended to other hydrophobic low-molecular-weight toxins such as T-2 mycotoxin. The formation of large molecular aggregates of nonylphenol and T-2 mycotoxin molecules on the surface was proved by the AFM study.

IgE-Binding Epitope Mapping and Tissue Localization of the Major American Cockroach Allergen Per a 2.

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Lee, Mey Fann; Chang, Chia Wei; Song, Pei Pong; Hwang, Guang Yuh; Lin, Shyh Jye; Chen, Yi Hsing

2015-07-01

Cockroaches are the second leading allergen in Taiwan. Sensitization to Per a 2, the major American cockroach allergen, correlates with clinical severity among patients with airway allergy, but there is limited information on IgE epitopes and tissue localization of Per a 2. This study aimed to identify Per a 2 linear IgE-binding epitopes and its distribution in the body of a cockroach. The cDNA of Per a 2 was used as a template and combined with oligonucleotide primers specific to the target areas with appropriate restriction enzyme sites. Eleven overlapping fragments of Per a 2 covering the whole allergen molecule, except 20 residues of signal peptide, were generated by PCR. Mature Per a 2 and overlapping deletion mutants were affinity-purified and assayed for IgE reactivity by immunoblotting. Three synthetic peptides comprising the B cell epitopes were evaluated by direct binding ELISA. Rabbit anti-Per a 2 antibody was used for immunohistochemistry. Human linear IgE-binding epitopes of Per a 2 were located at the amino acid sequences 57-86, 200-211, and 299-309. There was positive IgE binding to 10 tested Per a 2-allergic sera in 3 synthetic peptides, but none in the controls. Immunostaining revealed that Per a 2 was localized partly in the mouth and midgut of the cockroach, with the most intense staining observed in the hindgut, suggesting that the Per a 2 allergen might be excreted through the feces. Information on the IgE-binding epitope of Per a 2 may be used for designing more specific diagnostic and therapeutic approaches to cockroach allergy.

Native Mass Spectrometry, Ion mobility, and Collision-Induced Unfolding Categorize Malaria Antigen/Antibody Binding

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Huang, Yining; Salinas, Nichole D.; Chen, Edwin; Tolia, Niraj H.; Gross, Michael L.

2017-09-01

Plasmodium vivax Duffy Binding Protein (PvDBP) is a promising vaccine candidate for P. vivax malaria. Recently, we reported the epitopes on PvDBP region II (PvDBP-II) for three inhibitory monoclonal antibodies (2D10, 2H2, and 2C6). In this communication, we describe the combination of native mass spectrometry and ion mobility (IM) with collision induced unfolding (CIU) to study the conformation and stabilities of three malarial antigen-antibody complexes. These complexes, when collisionally activated, undergo conformational changes that depend on the location of the epitope. CIU patterns for PvDBP-II in complex with antibody 2D10 and 2H2 are highly similar, indicating comparable binding topology and stability. A different CIU fingerprint is observed for PvDBP-II/2C6, indicating that 2C6 binds to PvDBP-II on an epitope different from 2D10 and 2H2. This work supports the use of CIU as a means of classifying antigen-antibody complexes by their epitope maps in a high throughput screening workflow. [Figure not available: see fulltext.

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

Technical note: Protozoa-specific antibodies raised in sheep plasma bind to their target protozoa in the rumen.

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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.

Serum IgE Induced Airway Smooth Muscle Cell Remodeling Is Independent of Allergens and Is Prevented by Omalizumab

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Roth, Michael; Zhao, Feng; Zhong, Jun; Lardinois, Didier; Tamm, Michael

2015-01-01

Background Airway wall remodeling in allergic asthma is reduced after treatment with humanized anti-IgE-antibodies. We reported earlier that purified IgE, without the presence of allergens, is sufficient to induce airway wall remodeling due to airway smooth muscle cell (ASMC) activity deposing extracellular matrix. Objective We postulate that IgE contained in serum of allergic asthma patients, in the absence of allergens, stimulates ASMC remodeling activities and can be prevented by anti-IgE antibodies. Methods Isolated human ASMC were exposed to serum obtained from: (i) healthy controls, or patients with (ii) allergic asthma, (iii) non-allergic asthma, and (iv) atopic non-asthma patients. Proliferation and the deposition of collagens and fibronectin were determined after 3 and 5 days. Results Serum from patients with allergies significantly stimulated: (i) ASMC proliferation, (ii) deposition of collagen type-I (48 hours) and (iii) of fibronectin (24 hours). One hour pre-incubation with Omalizumab prevented these three effects of allergic serum, but had no significant effect on serum from healthy donors or non-allergic asthma patients. Interestingly, the addition of allergens did not further increase any of the IgE effects. Conclusion and Clinical Relevance Our data provides experimental evidence that the beneficial effect of Omalizumab on airway wall remodeling and improved lung function may be due to its direct action on IgE bound ASMC. PMID:26332463

Serum IgE Induced Airway Smooth Muscle Cell Remodeling Is Independent of Allergens and Is Prevented by Omalizumab.

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Michael Roth

Full Text Available Airway wall remodeling in allergic asthma is reduced after treatment with humanized anti-IgE-antibodies. We reported earlier that purified IgE, without the presence of allergens, is sufficient to induce airway wall remodeling due to airway smooth muscle cell (ASMC activity deposing extracellular matrix.We postulate that IgE contained in serum of allergic asthma patients, in the absence of allergens, stimulates ASMC remodeling activities and can be prevented by anti-IgE antibodies.Isolated human ASMC were exposed to serum obtained from: (i healthy controls, or patients with (ii allergic asthma, (iii non-allergic asthma, and (iv atopic non-asthma patients. Proliferation and the deposition of collagens and fibronectin were determined after 3 and 5 days.Serum from patients with allergies significantly stimulated: (i ASMC proliferation, (ii deposition of collagen type-I (48 hours and (iii of fibronectin (24 hours. One hour pre-incubation with Omalizumab prevented these three effects of allergic serum, but had no significant effect on serum from healthy donors or non-allergic asthma patients. Interestingly, the addition of allergens did not further increase any of the IgE effects.Our data provides experimental evidence that the beneficial effect of Omalizumab on airway wall remodeling and improved lung function may be due to its direct action on IgE bound ASMC.

Allergen cross-reactivity between Pityrosporum orbiculare and Candida albicans.

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Huang, X; Johansson, S G; Zargari, A; Nordvall, S L

1995-08-01

Pityrosporum orbiculare and Candida albicans extracts were separated by SDS-PAGE, and IgE binding was detected by immunoblotting with 21 patient sera that were RAST positive to both yeasts. Cross-wise inhibition was performed of IgE binding of a serum pool containing IgE antibodies to both yeasts. The pool was mixed with serial dilutions of P. orbiculare or C. albicans extracts, and incubated with strips containing separated allergen. IgE binding was quantified by densitometric scanning and percent inhibition was calculated as well as the respective ratios between required extract concentration for 50% inhibition in heterologous compared to homologous inhibition for each component (inhibition ratio). Ten components of P. orbiculare were detected by more than 60% of the sera. IgE binding to C. albicans was weak, and only to four bands was IgE binding detected by more than 30% of the sera. The most important C. albicans allergen was a 48-kDa band, to which IgE of half of the patient sera bound. There was little inhibition of IgE binding to P. orbiculare with C. albicans. Thus, all but three components exhibited an inhibition ratio higher than 100. The inhibition ratio of the 48-kDa C. albicans compound was 50, thus indicating some degree of cross-reactivity. Significant cross-reactivity was shown by C. albicans compounds of 18, 24, 26, 34, and 38 kDa, the inhibition ratios of which were less than 10. There was some degree of cross-reactivity between apparent protein allergens of the two yeasts, but IgE antibodies to C. albicans do not merely reflect sensitization to P. orbiculare.

The influence of a residual group in low-molecular-weight allergoids of Artemisia vulgaris pollen on their allergenicity, IgE- and IgG-binding properties.

Science.gov (United States)

Cirković, T; Gavrović-Jankulović, M; Prisić, S; Jankov, R M; Burazer, L; Vucković, O; Sporcić, Z; Paranos, S

2002-11-01

Reaction of epsilon-amino groups of lysine with potassium cyanate, maleic, or succinic anhydride leads to allergoids of low molecular weight. No study has been performed to compare their properties and investigate the influence of a residual group on allergenicity and human IgE- and IgG-binding of these derivatives. Allergoids of a pollen extract of Artemisia vulgaris were obtained by means of potassium cyanate, and succinic and maleic anhydride. Biochemical properties were investigated by determination of amino groups, enzyme activity, isoelectric focusing IEF and SDS-PAGE. IgE- and IgG-binding was determined using immunoblots and ELISA inhibition. Allergenicity was investigated by skin prick tests (SPT) on a group of 52 patients, of which 6 were control subjects, 30 were patients with no previous immunotherapy (IT), and 16 were patients undergoing immunotherapy. The same degree of amino-group modification (more than 85%), residual enzyme activity (less then 15%), IEF, and SDS-PAGE pattern were noted. In the immunoblots of IgE-binding, there was more pronounced reduction in the succinyl and maleyl derivatives than in the carbamyl one. IgG-binding was less affected by carbamylation than by acid anhydride modification. The SPT showed that the succinylated derivative had the most reduced allergenicity (98% showed a reduced wheal diameter when tested with the succinyl derivative, 87% with the maleyl allergoid, and 83% with the carbamyl allergoid). The most significant difference among allergoids could be seen in the group of patients with high skin reactivity (83% of patients showed no reaction to the succinyl derivative when compared to the value of 28% for the carbamyl derivative or 22% for the maleyl derivative). According to our results, all three modification procedures yielded allergoids with a similar extent of modification. No single biochemical parameter investigated in the study could predict the degree of reduced allergenicity in vivo. The most reduced

Light-chain residue 95 is critical for antigen binding and multispecificity of monoclonal antibody G2.

Science.gov (United States)

Usui, Daiki; Inaba, Satomi; Kamatari, Yuji O; Ishiguro, Naotaka; Oda, Masayuki

2017-09-02

The monoclonal antibody, G2, specifically binds to the immunogen peptide derived from the chicken prion protein, Pep18mer, and two chicken proteins derived peptides, Pep8 and Pep395; G2 binds with equal affinity to Pep18mer. The amino acid sequences of the three peptides are completely different, and so the recognition mechanism of G2 is unique and interesting. We generated a single-chain Fv (scFv) antibody of G2, and demonstrated its correct folding with an antigen binding function similar to intact G2 antibody. We also generated a Pro containing mutant of G2 scFv at residue 95 of the light chain, and analyzed its antigen binding using a surface plasmon biosensor. The mutant lost its binding ability to Pep18mer, but remained those to Pep8 and Pep395. The results clearly indicate residue 95 as being critical for multispecific antigen binding of G2 at the site generated from the junctional diversity introduced at the joints between the V and J gene segments. Copyright © 2017 Elsevier Inc. All rights reserved.

Heparin-associated thrombocytopenia: antibody binding specificity to platelet antigens.

Science.gov (United States)

Lynch, D M; Howe, S E

1985-11-01

Sera from four patients with heparin-associated thrombocytopenia (HAT) were evaluated by a quantitative enzyme-linked immunosorbent assay (ELISA) to detect heparin-dependent serum platelet-bindable immunoglobulin (S-PBIg) and by Western blotting and immunoprecipitation to investigate the specificity of the antibody binding. All HAT sera showed mildly increased S-PBIg (mean, 7.8 fg per platelet; normal, less than 6.0 fg per platelet) to intact target platelets in the ELISA, which was markedly increased in the presence of heparin (mean, 20.9 fg per platelet). This increase was 20-fold greater than normal control sera, which showed a mean differential increase of only 0.5 fg per platelet. Immunoglobulin binding specificity to platelet antigens was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of platelet lysate with transfer of the platelet fractions onto nitrocellulose strips (Western blotting) and subsequent immunoassay using HAT and normal sera. In the presence of heparin, the four HAT patients demonstrated increased binding of immunoglobulin to platelet antigens of apparent molecular weights of 180, 124, and 82 kd. Radiolabeled heparin when incubated with HAT sera, normal sera, or albumin blanks bound to platelet proteins of the same apparent molecular weights. These observations are consistent with current hypotheses suggesting that HAT antibody is directed to heparin-platelet complexes or, alternatively, that heparin induces conformational change of antigenic sites on the platelet membrane.

IgG4 and IgE co-positive group found in idiopathic orbital inflammatory disease

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Peng-Xiang Zhao

2018-01-01

Full Text Available AIM: To reveal the cytokines involved in idiopathic orbital inflammatory disease (IOID and the relationship between Th17 cells, IgE and IOID pathogenesis. METHODS: Whole blood samples were processed immediately after collection and serological IgG4, IgG, and IgE antibodies were tested using ELISA. IOID and orbital cavernous hemangioma (CH tissue samples underwent Bio-Plex multiplex cytokine detection. Hematoxylin-Eosin (HE staining of all paraffin samples suggested the histological features of IOIDs, and expressions of IgG4 and IL-17A in affected tissues were detected by immunohistochemistry. RESULTS: Among 40 IOID plasma samples, 52.5% (21/40 were positive for IgG4 and 25% (10/40 were positive for IgE. Overlapped IgG4 or IgE positive samples accounted for 22.5% (9/40. Therefore, IOID samples were separated into three groups. The IgE+/IgG4+ group had a relevantly lower level of pro-inflammatory cytokine expression. IL-4 (Th2 cell related, IL-10 and TGF-β1 (Treg cell immunity related were elevated in all three groups. Some of the Th17 cell related cytokines (i.e. IL-17A/F, IL-25, IL-23, and IL-33 displayed higher expression levels in the IgE-/IgG4- group compared to the other two groups. CONCLUSION: We discovered an IgG4-IgE co-positive group as well as Th17 cell immune involvement in IgG4-IgE co-negative subgtroup in IOID for the first time. The pathogenesis of IOID could differ from different subgroups according to the IgG4 and IgE detection. Therefore, we recommend that, Treatment stratagy should be made according to the clinical assessment of IgG4-IgE and Th17 profile detection.

Antigen-decorated shell cross-linked nanoparticles: synthesis, characterization, and antibody interactions.

Science.gov (United States)

Joralemon, Maisie J; Smith, Norah L; Holowka, David; Baird, Barbara; Wooley, Karen L

2005-01-01

Antigen-decorated shell cross-linked knedel-like nanoparticles (SCKs) were synthesized and studied as multivalent nanoscale surfaces from which antibody-binding units were presented in a manner that was designed to approach virus particle surfaces. The SCK nanostructures were fabricated with control over the number of antigenic groups, from mixed micellization of amphiphilic diblock copolymer building blocks that contained either an antigen (2,4-dinitrophenyl) or an ethylpropionate group at the hydrophilic alpha-chain terminus. Amphiphilic diblock copolymers were synthesized by atom transfer radical polymerization of tert-butyl acrylate and methyl acrylate sequentially from either a 2,4-dinitrophenyl-functionalized initiator or ethyl 2-bromopropionate, followed by selective removal of the tert-butyl groups to afford 2,4-dinitrophenyl-poly(acrylic acid)60-b-poly(methyl acrylate)60 (DNP-PAA(60)-b-PMA60) and poly(acrylic acid)70-b-poly(methyl acrylate) (PAA70-b-PMA70). Micelles were assembled via addition of water to THF solutions of the polymers in 0:1, 1:1, and 1:0 molar ratios of DNP-PAA60-b-PMA60 to PAA70-b-PMA70, followed by dialysis against water. The acrylic acid groups of the micelle coronas were partially cross-linked (nominally 50%) with 2,2'-(ethylenedioxy)bis(ethylamine), in the presence of 1-(3'-dimethylaminopropyl)-3-ethylcarbodiimide methiodide. Following extensive dialysis against water, the 0%, 50%, and 100% dinitrophenylated shell cross-linked nanoparticles (DNP-SCKs) were characterized with dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), infrared and UV-vis spectroscopies, and analytical ultracentrifugation (AU). The surface accessibility and bioavailability of the DNP units upon the DNP-SCKs were investigated by performing quenching titrations of fluorescein-labeled IgE antibody in solution and degranulation of IgE

Generation of IgE-based immunotherapies against HER-2 overexpressing tumours

International Nuclear Information System (INIS)

Knittelfelder, R.

2010-01-01

In combination with chemotherapy or radiation, passive immunotherapy with monoclonal antibodies is state of the art in cancer therapy. For this purpose, two properties of antibodies are harnessed: i) via the Fab fragment they bind a specific tumour antigen and ii) via the Fc portion they recruit effector cells and activate the complement system. One of these antibodies is trastuzumab (Herceptin), a growth-inhibitory humanized monoclonal IgG1 antibody recognizing the tumour antigen HER-2, which is overexpressed in 30% of human breast cancers. Interestingly, all antibodies applied for passive immunotherapy are so far exclusively of the IgG subclass. In contrast, antibodies of the IgE subclass are best-known for their detrimental function in type I hypersensitivity. It is little-known that IgE has anti-tumour capacity which could be exploited for immunotherapy of cancer. Thus, the aim of this doctoral thesis was to examine alternative strategies for cancer treatment based on IgE antibodies, and to compare their efficacy with that of IgG. The oral immunization route is well suited for the induction of a Th2 immunity including high affine IgE responses to administered antigens. Therefore, the establishment of an IgE dependent food allergy model in mice is described, which we applied also for our cancer studies. When mice were fed with different concentrations of ovalbumin under concomitant anti-acid medication, an antigen-specific IgE induction in a Th2 environment could be achieved. This oral vaccination regimen was also used for feeding HER-2 mimotopes, i.e. epitope-mimics of the anti-HER-2 IgG antibody trastuzumab. Indeed, these mimotopes induced IgE antibodies recognizing the tumour antigen which were able to bind HER-2 overexpressing breast cancer cells and led to tumour cell lysis. Complementary to this active immunotherapeutic approach a trastuzumab-like IgE antibody for passive immunotherapy was constructed. We could show that this trastuzumab IgE exhibited the

Immunoglobulin E antibodies to pollens augmented in dogs by virus vaccines.

Science.gov (United States)

Frick, O L; Brooks, D L

1983-03-01

An inbred "atopic dog colony" was established to study the effect of viruses on immunoregulation of immunoglobulin (Ig) E antibodies. Dogs were selected for high skin reactivity to grass and weed pollens. Their offspring were inoculated with pollen extracts in alum immediately after routine vaccinations (attenuated live-virus vaccines for canine distemper and infectious canine hepatitis, and a killed bacterin for Leptospira). Heat labile antipollen IgE antibodies were measured by passive cutaneous anaphylaxis. Pups vaccinated for canine distemper before being given pollen extracts had many more IgE antibodies than did their control littermates who were not vaccinated until after the last pollen extract injection. This may be a natural example of the "allergic break-through phenomenon."

Antibody-Unfolding and Metastable-State Binding in Force Spectroscopy and Recognition Imaging

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Kaur, Parminder; Qiang-Fu; Fuhrmann, Alexander; Ros, Robert; Kutner, Linda Obenauer; Schneeweis, Lumelle A.; Navoa, Ryman; Steger, Kirby; Xie, Lei; Yonan, Christopher; Abraham, Ralph; Grace, Michael J.; Lindsay, Stuart

2011-01-01

Force spectroscopy and recognition imaging are important techniques for characterizing and mapping molecular interactions. In both cases, an antibody is pulled away from its target in times that are much less than the normal residence time of the antibody on its target. The distribution of pulling lengths in force spectroscopy shows the development of additional peaks at high loading rates, indicating that part of the antibody frequently unfolds. This propensity to unfold is reversible, indicating that exposure to high loading rates induces a structural transition to a metastable state. Weakened interactions of the antibody in this metastable state could account for reduced specificity in recognition imaging where the loading rates are always high. The much weaker interaction between the partially unfolded antibody and target, while still specific (as shown by control experiments), results in unbinding on millisecond timescales, giving rise to rapid switching noise in the recognition images. At the lower loading rates used in force spectroscopy, we still find discrepancies between the binding kinetics determined by force spectroscopy and those determined by surface plasmon resonance—possibly a consequence of the short tethers used in recognition imaging. Recognition imaging is nonetheless a powerful tool for interpreting complex atomic force microscopy images, so long as specificity is calibrated in situ, and not inferred from equilibrium binding kinetics. PMID:21190677

The monoclonal S9.6 antibody exhibits highly variable binding affinities towards different R-loop sequences.

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Fabian König

Full Text Available The monoclonal antibody S9.6 is a widely-used tool to purify, analyse and quantify R-loop structures in cells. A previous study using the surface plasmon resonance technology and a single-chain variable fragment (scFv of S9.6 showed high affinity (0.6 nM for DNA-RNA and also a high affinity (2.7 nM for RNA-RNA hybrids. We used the microscale thermophoresis method allowing surface independent interaction studies and electromobility shift assays to evaluate additional RNA-DNA hybrid sequences and to quantify the binding affinities of the S9.6 antibody with respect to distinct sequences and their GC-content. Our results confirm high affinity binding to previously analysed sequences, but reveals that binding affinities are highly sequence specific. Our study presents R-loop sequences that independent of GC-content and in different sequence variations exhibit either no binding, binding affinities in the micromolar range and as well high affinity binding in the nanomolar range. Our study questions the usefulness of the S9.6 antibody in the quantitative analysis of R-loop sequences in vivo.

Topography of the high-affinity lysine binding site of plasminogen as defined with a specific antibody probe

International Nuclear Information System (INIS)

Miles, L.A.; Plow, E.F.

1986-01-01

An antibody population that reacted with the high-affinity lysine binding site of human plasminogen was elicited by immunizing rabbits with an elastase degradation product containing kringles 1-3 (EDP I). This antibody was immunopurified by affinity chromatography on plasminogen-Sepharose and elution with 0.2 M 6-aminohexanoic acid. The eluted antibodies bound [ 125 I]EDP I, [ 125 I]Glu-plasminogen, and [ 125 I]Lys-plasminogen in radioimmunoassays, and binding of each ligand was at least 99% inhibited by 0.2 M 6-aminohexanoic acid. The concentrations for 50% inhibition of [ 125 I]EDP I binding by tranexamic acid, 6-aminohexanoic acid, and lysine were 2.6, 46, and l730 μM, respectively. Similar values were obtained with plasminogen and suggested that an unoccupied high-affinity lysine binding site was required for antibody recognition. The antiserum reacted exclusively with plasminogen derivatives containing the EDP I region and did not react with those lacking an EDP I region, or with tissue plasminogen activator or prothrombin, which also contains kringles. By immunoblotting analyses, a chymotryptic degradation product of M/sub r/ 20,000 was derived from EDP I that retained reactivity with the antibody. α 2 -Antiplasmin inhibited the binding of radiolabeled EDP I, Glu-plasminogen, or Lys-plasminogen by the antiserum, suggesting that the recognized site is involved in the noncovalent interaction of the inhibitor with plasminogen. The binding of [ 125 I]EDP I to fibrin was also inhibited by the antiserum. The observations provide independent evidence for the role of the high-affinity lysine binding site in the functional interactions of plasminogen with its primary substrate and inhibitor

Neutralisation and binding of VHS virus by monovalent antibody fragments

DEFF Research Database (Denmark)

Cupit, P.M.; Lorenzen, Niels; Strachan, G.

2001-01-01

We have previously reported the cloning and characterisation of the heavy and light chain variable domain genes encoding three monoclonal antibodies (Mabs) that bind viral haemorrhagic septicaemia virus (VHSV). Two of these antibodies, 3F1H10 and 3F1A2 both neutralised the virus though 3F1A2...... appeared to recognise a broader range of virus isolates. The variable domains of these two antibodies differ by only four residues (Lorenzen et al., 2000a. Fish Shellfish Immunol. 10, 129-142). To further study the mechanism of neutralisation, Fab fragments as well as a series of recombinant bacterial...... single chain antibody (scAb) fragments were generated from the three anti-VHSV Mabs and their variable domain genes, respectively. Fabs and scAbs derived from the neutralising Mabs were both able to neutralise the VHSV type 1 isolate DK-F1. In addition, a series of scAb fragments were produced using...

Maximizing in vivo target clearance by design of pH-dependent target binding antibodies with altered affinity to FcRn.

Science.gov (United States)

Yang, Danlin; Giragossian, Craig; Castellano, Steven; Lasaro, Marcio; Xiao, Haiguang; Saraf, Himanshu; Hess Kenny, Cynthia; Rybina, Irina; Huang, Zhong-Fu; Ahlberg, Jennifer; Bigwarfe, Tammy; Myzithras, Maria; Waltz, Erica; Roberts, Simon; Kroe-Barrett, Rachel; Singh, Sanjaya

2017-10-01

Antibodies with pH-dependent binding to both target antigens and neonatal Fc receptor (FcRn) provide an alternative tool to conventional neutralizing antibodies, particularly for therapies where reduction in antigen level is challenging due to high target burden. However, the requirements for optimal binding kinetic framework and extent of pH dependence for these antibodies to maximize target clearance from circulation are not well understood. We have identified a series of naturally-occurring high affinity antibodies with pH-dependent target binding properties. By in vivo studies in cynomolgus monkeys, we show that pH-dependent binding to the target alone is not sufficient for effective target removal from circulation, but requires Fc mutations that increase antibody binding to FcRn. Affinity-enhanced pH-dependent FcRn binding that is double-digit nM at pH 7.4 and single-digit nM at pH 6 achieved maximal target reduction when combined with similar target binding affinities in reverse pH directions. Sustained target clearance below the baseline level was achieved 3 weeks after single-dose administration at 1.5 mg/kg. Using the experimentally derived mechanistic model, we demonstrate the essential kinetic interplay between target turnover and antibody pH-dependent binding during the FcRn recycling, and identify the key components for achieving maximal target clearance. These results bridge the demand for improved patient dosing convenience with the "know-how" of therapeutic modality by design.

Comparison of in vitro cell binding characteristics of four monoclonal antibodies and their individual tumor localization properties in mice

International Nuclear Information System (INIS)

Andrew, S.M.; Johnstone, R.W.; Russell, S.M.; McKenzie, I.F.; Pietersz, G.A.

1990-01-01

Although many antibodies are being used for imaging studies, it is not clear which in vitro properties of antibodies will best reflect their in vivo characteristics. The ability to correlate in vitro binding characteristics of monoclonal antibodies to tumor antigens with their in vivo localization characteristics, particularly with respect to tumor localization properties, is desirable for rapid selection of monoclonal antibodies with potential for clinical use. The in vitro binding characteristics of three monoclonal antibodies to the murine Ly-2.1 antigen and one to the Ly-3.1 antigen have been studied on cultured tumor cells bearing these antigens. The association and dissociation rate constants, apparent affinity, and immunoreactivity of each antibody in vitro were compared with their ability to localize the s.c. tumors from the same cell line growing in Ly-2.1-/Ly-3.1-mice. The antibody with the highest affinity and fastest association rate localized to tumor at the earliest time (16-20 h after injection) and had the highest percentage of the injected dose/g in the tumor (greater than 25%). The antibody with the lowest affinity showed significantly less localization to tumor cells, compared with the other three antibodies. The ranking of the antibodies by affinity agreed with the ranking in terms of their ability to localize to tumors, but the in vitro immunoreactivity of the antibodies, as measured by a cell binding assay, did not correlate with their tumor localization properties. Immunoscintigraphic studies did not precisely correlate with biodistribution data or in vitro binding characteristics, because tumors could be satisfactorily imaged with each antibody, although it was noted that the antibody with the highest affinity gave the best image

Naturally Acquired Antibodies to Plasmodium vivax Duffy Binding Protein (DBP) in Rural Brazilian Amazon

Science.gov (United States)

Souza-Silva, Flávia A.; da Silva-Nunes, Mônica; Sanchez, Bruno A. M.; Ceravolo, Isabela P.; Malafronte, Rosely S.; Brito, Cristiana F. A.; Ferreira, Marcelo U.; Carvalho, Luzia H.

2010-01-01

Duffy binding protein (DBP), a leading malaria vaccine candidate, plays a critical role in Plasmodium vivax erythrocyte invasion. Sixty-eight of 366 (18.6%) subjects had IgG anti-DBP antibodies by enzyme-linked immunosorbent assay (ELISA) in a community-based cross-sectional survey in the Brazilian Amazon Basin. Despite continuous exposure to low-level malaria transmission, the overall seroprevalence decreased to 9.0% when the population was reexamined 12 months later. Antibodies from 16 of 50 (36.0%) subjects who were ELISA-positive at the baseline were able to inhibit erythrocyte binding to at least one of two DBP variants tested. Most (13 of 16) of these subjects still had inhibitory antibodies when reevaluated 12 months later. Cumulative exposure to malaria was the strongest predictor of DBP seropositivity identified by multiple logistic regression models in this population. The poor antibody recognition of DBP elicited by natural exposure to P. vivax in Amazonian populations represents a challenge to be addressed by vaccine development strategies. PMID:20133990

IgE profiles of Bermuda grass pollen sensitised patients evaluated by Phleum pratense allergens Phl P 1, 2, 4, 5, 6 , 7, 11, 12.

Science.gov (United States)

Rossi, Renato E; Monasterolo, Giorgio; Prina, Paolo; Coco, Giuseppe; Operti, Daniela; Rossi, Lucilla

2008-06-01

Despite the difference in geographical dominance of certain grasses, a high degree of allergenic similarity or cross-reactivity between Bermuda grass pollen (BGP) and timothy grass pollen (TGP) has been previously demonstrated. The aim of the present study was to ascertain the sensitisation to TGP in 411 patients known for their reactivity to BGP extracts by analysing their reactivity to crude timothy pollen extract and timothy pollen purified allergens, establishing their specific IgE-profiles. Using the immunoenzymatic CAP method we evaluated IgE-specific antibodies for BGP- and TGP- extracts and the timothy recombinant (r) and natural (n) allergens rPhl p 1, rPhl p 2, nPhl p 4, rPhl p 5, rPhl p 6, rPhl p 7, rPhl p 11, and rPhl p 12. BGP-IgE positive patients (median = 8.0 kUA/l, 2.8-22.2 kUA/l 25th-75th percentile) simultaneously had IgE positive results for TGP (100% of subjects)(median = 48.9 kUA/l, 19.8- > 100 kUA/l 25th-75th percentile) and high prevalence of sensitization to 6/8 Phleum pratense allergens (Phl p 1, 2, 4, 5, 6, 11, markers of genuine sensitisation to TGP) other than profilin and calcium binding protein. More than 72% of BGP allergic patients were co-sensitised to rPhl p 1, rPhl p 2, nPhl p 4, rPhl p 5, rPhl p 6. A decrease of total and specific IgE with patients' age was observed. Our data show that all BGP-allergic patients simultaneously exhibit higher IgE antibody levels to recombinant and natural P. pratense allergens as well as to crude TGP extract. This suggests that when choosing an immunotherapeutic regimen for BGP-sensitised patients (after establishing their IgE profile via purified TGP-allergens), subcutaneous or sublingual TGP-extract vaccines in appropriate doses, in order to influence T epitope specificity, might be beneficial. Though extremely uncommon, in cases where a patient is exclusively BGP allergen-sensitised, BGP-extract therapy is the appropriate therapeutic response.

Site-directed antibody immobilization using a protein A-gold binding domain fusion protein for enhanced SPR immunosensing.

Science.gov (United States)

de Juan-Franco, Elena; Caruz, Antonio; Pedrajas, J R; Lechuga, Laura M

2013-04-07

We have implemented a novel strategy for the oriented immobilization of antibodies onto a gold surface based on the use of a fusion protein, the protein A-gold binding domain (PAG). PAG consists of a gold binding peptide (GBP) coupled to the immunoglobulin-binding domains of staphylococcal protein A. This fusion protein provides an easy and fast oriented immobilization of antibodies preserving its native structure, while leaving the antigen binding sites (Fab) freely exposed. Using this immobilization strategy, we have demonstrated the performance of the immunosensing of the human Growth Hormone by SPR. A limit of detection of 90 ng mL(-1) was obtained with an inter-chip variability lower than 7%. The comparison of this method with other strategies for the direct immobilization of antibodies over gold surfaces has showed the enhanced sensitivity provided by the PAG approach.

Mutational epitope analysis of Pru av 1 and Api g 1, the major allergens of cherry (Prunus avium) and celery (Apium graveolens): correlating IgE reactivity with three-dimensional structure.

Science.gov (United States)

Neudecker, Philipp; Lehmann, Katrin; Nerkamp, Jörg; Haase, Tanja; Wangorsch, Andrea; Fötisch, Kay; Hoffmann, Silke; Rösch, Paul; Vieths, Stefan; Scheurer, Stephan

2003-01-01

Birch pollinosis is often accompanied by adverse reactions to food due to pollen-allergen specific IgE cross-reacting with homologous food allergens. The tertiary structure of Pru av 1, the major cherry (Prunus avium) allergen, for example, is nearly identical with Bet v 1, the major birch (Betula verrucosa) pollen allergen. In order to define cross-reactive IgE epitopes, we generated and analysed mutants of Pru av 1 and Api g 1.0101, the major celery (Apium graveolens) allergen, by immunoblotting, EAST (enzyme allergosorbent test), CD and NMR spectroscopy. The mutation of Glu45 to Trp45 in the P-loop region, a known IgE epitope of Bet v 1, significantly reduced IgE binding to Pru av 1 in a subgroup of cherry-allergic patients. The backbone conformation of Pru av 1 wild-type is conserved in the three-dimensional structure of Pru av 1 Trp45, demonstrating that the side chain of Glu45 is involved in a cross-reactive IgE epitope. Accordingly, for a subgroup of celery-allergic patients, IgE binding to the homologous celery allergen Api g 1.0101 was enhanced by the mutation of Lys44 to Glu. The almost complete loss of IgE reactivity to the Pru av 1 Pro112 mutant is due to disruption of its tertiary structure. Neither the mutation Ala112 nor deletion of the C-terminal residues 155-159 influenced IgE binding to Pru av 1. In conclusion, the structure of the P-loop partially explains the cross-reactivity pattern, and modulation of IgE-binding by site-directed mutagenesis is a promising approach to develop hypo-allergenic variants for patient-tailored specific immunotherapy. PMID:12943529

Collaborative enhancement of antibody binding to distinct PECAM-1 epitopes modulates endothelial targeting.

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Ann-Marie Chacko

Full Text Available Antibodies to platelet endothelial cell adhesion molecule-1 (PECAM-1 facilitate targeted drug delivery to endothelial cells by "vascular immunotargeting." To define the targeting quantitatively, we investigated the endothelial binding of monoclonal antibodies (mAbs to extracellular epitopes of PECAM-1. Surprisingly, we have found in human and mouse cell culture models that the endothelial binding of PECAM-directed mAbs and scFv therapeutic fusion protein is increased by co-administration of a paired mAb directed to an adjacent, yet distinct PECAM-1 epitope. This results in significant enhancement of functional activity of a PECAM-1-targeted scFv-thrombomodulin fusion protein generating therapeutic activated Protein C. The "collaborative enhancement" of mAb binding is affirmed in vivo, as manifested by enhanced pulmonary accumulation of intravenously administered radiolabeled PECAM-1 mAb when co-injected with an unlabeled paired mAb in mice. This is the first demonstration of a positive modulatory effect of endothelial binding and vascular immunotargeting provided by the simultaneous binding a paired mAb to adjacent distinct epitopes. The "collaborative enhancement" phenomenon provides a novel paradigm for optimizing the endothelial-targeted delivery of therapeutic agents.

Transfer of maternal IgE can be a common cause of increased IgE levels in cord blood

DEFF Research Database (Denmark)

Bønnelykke, Klaus; Pipper, Christian Bressen; Bisgaard, Hans

2010-01-01

IgE in cord blood is thought to be a product of the fetus. A high level of total IgE is therefore used as a measure of atopic propensity in the newborn. We recently found strong evidence that allergen-specific IgE in cord blood was the result of transfer of maternal IgE to fetal blood or cord blood...

The prevalence and identity of Chlamydia-specific IgE in children with asthma and other chronic respiratory symptoms

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Patel Katir K

2012-04-01

Full Text Available Abstract Background Recent studies have confirmed the presence of viable Chlamydia in the bronchoalveolar lavage (BAL fluid of pediatric patients with airway hyperresponsiveness. While specific IgG and IgM responses to C. pneumoniae are well described, the response and potential contribution of Ag-specific IgE are not known. The current study sought to determine if infection with Chlamydia triggers the production of pathogen-specific IgE in children with chronic respiratory diseases which might contribute to inflammation and pathology. Methods We obtained BAL fluid and serum from pediatric respiratory disease patients who were generally unresponsive to corticosteroid treatment as well as sera from age-matched control patients who saw their doctor for wellness checkups. Chlamydia-specific IgE was isolated from BAL and serum samples and their specificity determined by Western blot techniques. The presence of Chlamydia was confirmed by species-specific PCR and BAL culture assays. Results Chlamydial DNA was detected in the BAL fluid of 134/197 (68% patients. Total IgE increased with age until 15 years old and then decreased. Chlamydia-specific IgE was detected in the serum and/or BAL of 107/197 (54% patients suffering from chronic respiratory disease, but in none of the 35 healthy control sera (p p = 0.0001 tested positive for Chlamydia-specific IgE. Asthmatic patients had significantly higher IgE levels compared to non-asthmatics (p = 0.0001. Patients who were positive for Chlamydia DNA or culture had significantly higher levels of serum IgE compared to negative patients (p = 0.0071 and p = 0.0001 respectively. Only 6 chlamydial antigens induced Chlamydia-specific IgE and patients with C. pneumoniae-specific IgE had significantly greater levels of total IgE compared to C. pneumoniae-specific IgE negative ones (p = 0.0001. Conclusions IgE antibodies play a central role in allergic inflammation; therefore production of Chlamydia

Negativization rates of IgE radioimmunoassay and basophil activation test in immediate reactions to penicillins.

Science.gov (United States)

Fernández, T D; Torres, M J; Blanca-López, N; Rodríguez-Bada, J L; Gomez, E; Canto, G; Mayorga, C; Blanca, M

2009-02-01

Skin test sensitivity in patients with immediate allergy to penicillins tends to decrease over time, but no information is available concerning in vitro tests. We analysed the negativization rates of two in vitro methods that determine specific immunoglobulin E (IgE) antibodies, the basophil activation test using flow cytometry (BAT) and the radioallergosorbent test (RAST), in immediate allergic reactions to penicillins. Forty-one patients with immediate allergic reactions to amoxicillin were followed up over a 4-year period. BAT and RAST were performed at 6-month intervals. Patients were randomized into groups: Group I, skin tests carried out at regular intervals; Group II, skin tests made only at the beginning of the study. Differences were observed between RAST and BAT (P testing influenced the rate of negativization of the RAST assay, contributing to maintenance of in vitro sensitivity. Because of the loss of sensitivity over time, the determination of specific IgE antibodies to penicillins in patients with immediate allergic reactions must be done as soon as possible after the reaction.

Investigations on antibody binding to a micro-cantilever coated with a BAM pesticide residue

DEFF Research Database (Denmark)

Bache, Michael; Taboryski, Rafael Jozef; Schmid, Silvan

2011-01-01

-BAM antibody is measured using the CantiLab4© system from Cantion A/S with four gold-coated cantilevers and piezo resistive readout. The detection mechanism is in principle label-free, but fluorescent-marked antibodies have been used to subsequently verify the binding on the cantilever surface. The bending...

Development and characterization of polyclonal antibodies against the linker region of the telomere-binding protein TRF2

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Nadya V. Ilicheva

2018-03-01

Full Text Available Background: TRF2 (telomeric repeat binding factor 2 is an essential component of the telomere-binding protein complex shelterin. TRF2 induces the formation of a special structure of telomeric DNA and counteracts activation of DNA damage-response pathways telomeres. TRF2 has a poorly characterized linker region (udTRF2 between its homodimerization and DNA-binding domains. Some lines of evidence have shown that this region could be involved in TRF2 interaction with nuclear lamina. Results: In this study, the fragment of the TERF2 gene encoding udTRF2 domain of telomere-binding protein TRF2 was produced by PCR and cloned into the pET32a vector. The resulting plasmid pET32a-udTRF2 was used for the expression of the recombinant udTRF2 in E. coli RosettaBlue (DE3. The protein was isolated and purified using ammonium sulfate precipitation followed by ion-exchange chromatography. The purified recombinant protein udTRF2 was injected into guinea pigs to generate polyclonal antibodies. The ability of anti-udTRF2 antibodies to bind endogenous TRF2 in human skin fibroblasts was tested by western blotting and immunofluorescent staining. Conclusions: In this study, the recombinant protein udTRF2 and antibodies to it were generated. Both protein and antibodies will provide a useful tool for investigation of the functions of the udTRF2 domain and its role in the interaction between TRF2 and nuclear lamina. Keywords: Chromosomes, Molecular cloning, Nuclear lamina, Nucleoprotein complexes, Polyclonal antibodies, Recombinant polypeptide, Shelterin, Telomere-binding protein TRF2, Telomeres, Telomeric DNA, TTAGGG repeats

Diclofenac hypersensitivity: antibody responses to the parent drug and relevant metabolites.

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Andrea Harrer

2010-10-01

Full Text Available Hypersensitivity reactions against nonsteroidal antiinflammatory drugs (NSAIDs like diclofenac (DF can manifest as Type I-like allergic reactions including systemic anaphylaxis. However, except for isolated case studies experimental evidence for an IgE-mediated pathomechanism of DF hypersensitivity is lacking. In this study we aimed to investigate the possible involvement of drug- and/or metabolite-specific antibodies in selective DF hypersensitivity.DF, an organochemically synthesized linkage variant, and five major Phase I metabolites were covalently coupled to carrier proteins. Drug conjugates were analyzed for coupling degree and capacity to crosslink receptor-bound IgE antibodies from drug-sensitized mice. With these conjugates, the presence of hapten-specific IgE antibodies was investigated in patients' samples by ELISA, mediator release assay, and basophil activation test. Production of sulfidoleukotrienes by drug conjugates was determined in PBMCs from DF-hypersensitive patients. All conjugates were shown to carry more than two haptens per carrier molecule. Immunization of mice with drug conjugates induced drug-specific IgE antibodies capable of triggering mediator release. Therefore, the conjugates are suitable tools for detection of drug-specific antibodies and for determination of their anaphylactic activity. Fifty-nine patients were enrolled and categorized as hypersensitive either selectively to DF or to multiple NSAIDs. In none of the patients' samples evidence for drug/metabolite-specific IgE in serum or bound to allergic effector cells was found. In contrast, a small group of patients (8/59, 14% displayed drug/metabolite-specific IgG.We found no evidence for an IgE-mediated effector mechanism based on haptenation of protein carriers in DF-hypersensitive patients. Furthermore, a potential involvement of the most relevant metabolites in DF hypersensitivity reactions could be excluded.

Kinetics of Antibody Binding to Membranes of Living Bacteria Measured by a Photonic Crystal-Based Biosensor

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Ekaterina Rostova

2016-10-01

Full Text Available Optical biosensors based on photonic crystal surface waves (PC SWs offer a possibility to study binding interactions with living cells, overcoming the limitation of rather small evanescent field penetration depth into a sample medium that is characteristic for typical optical biosensors. Besides this, simultaneous excitation of s- and p-polarized surface waves with different penetration depths is realized here, permitting unambiguous separation of surface and volume contributions to the measured signal. PC-based biosensors do not require a bulk signal correction, compared to widely used surface plasmon resonance-based devices. We developed a chitosan-based protocol of PC chip functionalization for bacterial attachment and performed experiments on antibody binding to living bacteria measured in real time by the PCSW-based biosensor. Data analysis reveals specific binding and gives the value of the dissociation constant for monoclonal antibodies (IgG2b against bacterial lipopolysaccharides equal to KD = 6.2 ± 3.4 nM. To our knowledge, this is a first demonstration of antibody-binding kinetics to living bacteria by a label-free optical biosensor.

Human vaccination against Plasmodium vivax Duffy-binding protein induces strain-transcending antibodies

OpenAIRE

Payne, Ruth O.; Silk, Sarah E.; Elias, Sean C.; Milne, Kathryn H.; Rawlinson, Thomas A.; Llewellyn, David; Shakri, A. Rushdi; Jin, Jing; Labb?, Genevi?ve M.; Edwards, Nick J.; Poulton, Ian D.; Roberts, Rachel; Farid, Ryan; J?rgensen, Thomas; Alanine, Daniel G.W.

2017-01-01

BACKGROUND: Plasmodium vivax is the most widespread human malaria geographically; however, no effective vaccine exists. Red blood cell invasion by the P. vivax merozoite depends on an interaction between the Duffy antigen receptor for chemokines (DARC) and region II of the parasite's Duffy-binding protein (PvDBP_RII). Naturally acquired binding-inhibitory antibodies against this interaction associate with clinical immunity, but it is unknown whether these responses can be induced by human vac...

Thermodynamic model of binding of flexible bivalent haptens to antibody

Energy Technology Data Exchange (ETDEWEB)

Dembo, M; Goldstein, B

1978-01-01

Studies by Wilder et al. of the binding of Fab' fragments to small haptens have shown that the cross-linking constant (the equilibrium constant for binding an additional Fab' fragment to a hapten-Fab' complex) is strongly dependent on the length of the hapten. We present a simple model for predicting the relationship between the intermolecular cross-linking constant and the monovalent hapten-antibody binding constant. In particular we used the model to obtain the dependence of the cross-linking constant on the length of th hapten, the depth to which the hapten fills th Fab' binding site, and the size of the Fab' fragment. To test the model, we devised expressions which allowed us to analyze the data of Wilder et al. From their data we determined the values of two parameters which we took to be unknown in the theory, the size of the Fab' fragment and the depth to which the hapten fills the Fab' binding site. The values arrived at in this way agreed well with published measurements of these parameters.

Antibody Binding Alters the Characteristics and Contents of Extracellular Vesicles Released by Histoplasma capsulatum

Energy Technology Data Exchange (ETDEWEB)

Baltazar, Ludmila M.; Nakayasu, Ernesto S.; Sobreira, Tiago; Choi, Hyungwon; Casadevall, Arturo; Nimrichter, Leonardo; Nosanchuk, Joshua D.

2016-03-30

Histoplasma capsulatumproduces extracellular vesicles containing virulence-associated molecules capable of modulating host machinery, benefiting the pathogen. Treatment ofH. capsulatumcells with monoclonal antibodies (MAbs) can change the outcome of infection in mice. We evaluated the sizes, enzymatic contents, and proteomic profiles of the vesicles released by fungal cells treated with either protective MAb 6B7 (IgG1) or nonprotective MAb 7B6 (IgG2b), both of which bindH. capsulatumheat shock protein 60 (Hsp60). Our results showed that treatment with either MAb was associated with changes in size and vesicle loading. MAb treatments reduced vesicle phosphatase and catalase activities compared to those of vesicles from untreated controls. We identified 1,125 proteins in vesicles, and 250 of these manifested differences in abundance relative to that of proteins in vesicles isolated from yeast cells exposed to Hsp60-binding MAbs, indicating that surface binding of fungal cells by MAbs modified protein loading in the vesicles. The abundance of upregulated proteins in vesicles upon MAb 7B6 treatment was 44.8% of the protein quantities in vesicles from fungal cells treated with MAb 6B7. Analysis of orthologous proteins previously identified in vesicles from other fungi showed that different ascomycete fungi have similar proteins in their extracellular milieu, many of which are associated with virulence. Our results demonstrate that antibody binding can modulate fungal cell responses, resulting in differential loading of vesicles, which could alter fungal cell susceptibility to host defenses. This finding provides additional evidence that antibody binding modulates microbial physiology and suggests a new function for specific immunoglobulins through alterations of fungal secretion.

IMPORTANCEDiverse fungal species release extracellular vesicles, indicating that this is a

Investigations on antibody binding to a micro-cantilever coated with a BAM pesticide residue

Directory of Open Access Journals (Sweden)

Aamand Jens

2011-01-01

Full Text Available Abstract The attachment of an antibody to an antigen-coated cantilever has been investigated by repeated experiments, using a cantilever-based detection system by Cantion A/S. The stress induced by the binding of a pesticide residue BAM (2,6 dichlorobenzamide immobilized on a cantilever surface to anti-BAM antibody is measured using the CantiLab4© system from Cantion A/S with four gold-coated cantilevers and piezo resistive readout. The detection mechanism is in principle label-free, but fluorescent-marked antibodies have been used to subsequently verify the binding on the cantilever surface. The bending and increase in mass of each cantilever has also been investigated using a light interferometer and a Doppler Vibrometer. The system has been analyzed during repeated measurements to investigate whether the CantiLab4© system is a suited platform for a pesticide assay system.

Parvalbumin, a cross-reactive fish allergen, contains IgE-binding epitopes sensitive to periodate treatment and Ca2+ depletion.

Science.gov (United States)

Bugajska-Schretter, A; Elfman, L; Fuchs, T; Kapiotis, S; Rumpold, H; Valenta, R; Spitzauer, S

1998-01-01

Type I allergy to fish is a severe health problem in countries in which a large percentage of the population derive income from fishing. The aim of the study was to characterize cross-reactive IgE-binding components in six different fish species (cod, tuna, salmon, perch, carp, and eel). The effect of reducing extraction conditions, periodate treatment, and depletion of Ca2+ on binding of IgE to the allergens was investigated. Extracts were prepared under nonreducing and reducing conditions. IgE-binding components were characterized by IgE immunoblotting, and cross-reactive epitopes were studied by IgE-immunoblot inhibition experiments. To reveal calcium-sensitive or carbohydrate-containing epitopes, nitrocellulose-blotted extracts were exposed to ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) and periodate. Sera from all patients allergic to fish (n = 30) displayed IgE reactivity to parvalbumin, a 12 kd protein present in fish extracts from six different species. Reducing extraction conditions had no effect on IgE binding to parvalbumins, whereas periodate treatment and depletion of protein-bound calcium led to a substantial reduction of IgE binding. Parvalbumins from six different species contained cross-reactive IgE epitopes. Parvalbumin represents a cross-reactive fish allergen. It contains IgE epitopes that are sensitive to periodate treatment and Ca2+-depletion.

Solid phase measurements of antibody and lectin binding to xenogenic carbohydrate antigens

DEFF Research Database (Denmark)

Kirkeby, Svend; André, Sabine; Gabius, Hans-Joachim

2004-01-01

OBJECTIVES: In future pig-to-man xenotransplantation it is important to master tools that identify potentially xenogenic alphagalactose (Galalpha) antigens in the doner tissue. DESIGN AND METHODS: We have measured the binding potentials of Galalpha detecting lectins and antibodies, including...

Local IgE production in nonatopic nasal polyposis.

LENUS (Irish Health Repository)

Sheahan, Patrick

2012-02-01

INTRODUCTION: Chronic rhinosinusitis with nasal polyposis (CRSwNP) represents an eosinophilic T-helper 2 inflammatory response. Local production of IgE within nasal polyps (NPs) has been demonstrated, suggesting a role for local IgE in the pathogenesis of NP in atopic CRS patients. We hypothesized that local IgE specific to inhalant allergens may also play a role in the genesis of NP in nonatopic CRS patients. METHODS: Sinus and inferior turbinate tissue was obtained from nonatopic CRSwNP patients (n = 7), chronic rhinosinusitis without nasal polyps (CRSsNP) patients (n = 15), and healthy controls (n = 9) at the time of surgery. ImmunoCAP analysis (Phadia AB, Portage, MI) for 14 common inhalant antigens was performed on tissue homogenates to determine the antigen-specific response. RESULTS: Total IgE levels did not differ in sinus or turbinate tissue between CRSwNP, CRSsNP, or control patients. CRSwNP sinus tissue had higher levels of specific IgE for cockroach and plantain (p = .03) than other groups and elevated Alternaria IgE levels when compared with CRSsNP sinus tissue (p < .05). No significant differences were found for any of the other antigen-specific IgE levels. Fifty-seven percent of CRSwNP polyps demonstrated a polyclonal IgE response, whereas the other 43% had no demonstrable antigen-specific IgE. In contrast, only 17% of CRSsNP patients demonstrated a polyclonal response within sinus tissue, whereas 67% had no detectable antigen-specific IgE. There was no significant difference in levels of IgE in inferior turbinate tissue between the groups (p > .05). CONCLUSIONS: Localized mucosal IgE specific to common inhalant allergens appears to play a role in a subset of CRSwNP patients without evidence of systemic atopy.

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

Use of thermodynamic coupling between antibody-antigen binding and phospholipid acyl chain phase transition energetics to predict immunoliposome targeting affinity.

Science.gov (United States)

Klegerman, Melvin E; Zou, Yuejiao; Golunski, Eva; Peng, Tao; Huang, Shao-Ling; McPherson, David D

2014-09-01

Thermodynamic analysis of ligand-target binding has been a useful tool for dissecting the nature of the binding mechanism and, therefore, potentially can provide valuable information regarding the utility of targeted formulations. Based on a consistent coupling of antibody-antigen binding and gel-liquid crystal transition energetics observed for antibody-phosphatidylethanolamine (Ab-PE) conjugates, we hypothesized that the thermodynamic parameters and the affinity for antigen of the Ab-PE conjugates could be effectively predicted once the corresponding information for the unconjugated antibody is determined. This hypothesis has now been tested in nine different antibody-targeted echogenic liposome (ELIP) preparations, where antibody is conjugated to dipalmitoylphosphatidylethanolamine (DPPE) head groups through a thioether linkage. Predictions were satisfactory (affinity not significantly different from the population of values found) in five cases (55.6%), but the affinity of the unconjugated antibody was not significantly different from the population of values found in six cases (66.7%), indicating that the affinities of the conjugated antibody tended not to deviate appreciably from those of the free antibody. While knowledge of the affinities of free antibodies may be sufficient to judge their suitability as targeting agents, thermodynamic analysis may still provide valuable information regarding their usefulness for specific applications.

A camelid single-domain antibody neutralizes botulinum neurotoxin A by blocking host receptor binding

Energy Technology Data Exchange (ETDEWEB)

Yao, Guorui; Lam, Kwok-ho; Weisemann, Jasmin; Peng, Lisheng; Krez, Nadja; Perry, Kay; Shoemaker, Charles B.; Dong, Min; Rummel, Andreas; Jin, Rongsheng (BCH); (Cornell); (Tufts CTSI); (UCI); (MHH)

2017-08-07

Antibody treatment is currently the only available countermeasure for botulism, a fatal illness caused by flaccid paralysis of muscles due to botulinum neurotoxin (BoNT) intoxication. Among the seven major serotypes of BoNT/A-G, BoNT/A poses the most serious threat to humans because of its high potency and long duration of action. Prior to entering neurons and blocking neurotransmitter release, BoNT/A recognizes motoneurons via a dual-receptor binding process in which it engages both the neuron surface polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Previously, we identified a potent neutralizing antitoxin against BoNT/A1 termed ciA-C2, derived from a camelid heavy-chain-only antibody (VHH). In this study, we demonstrate that ciA-C2 prevents BoNT/A1 intoxication by inhibiting its binding to neuronal receptor SV2. Furthermore, we determined the crystal structure of ciA-C2 in complex with the receptor-binding domain of BoNT/A1 (HCA1) at 1.68 Å resolution. The structure revealed that ciA-C2 partially occupies the SV2-binding site on H_CA1, causing direct interference of HCA1 interaction with both the N-glycan and peptide-moiety of SV2. Interestingly, this neutralization mechanism is similar to that of a monoclonal antibody in clinical trials, despite that ciA-C2 is more than 10-times smaller. Taken together, these results enlighten our understanding of BoNT/A1 interactions with its neuronal receptor, and further demonstrate that inhibiting toxin binding to the host receptor is an efficient countermeasure strategy.

Double positivity to bee and wasp venom: improved diagnostic procedure by recombinant allergen-based IgE testing and basophil activation test including data about cross-reactive carbohydrate determinants.

Science.gov (United States)

Eberlein, Bernadette; Krischan, Lilian; Darsow, Ulf; Ollert, Markus; Ring, Johannes

2012-07-01

Specific IgE (sIgE) antibodies to both bee and wasp venom can be due to a sensitivity to both insect venoms or due to cross-reactive carbohydrate determinants (CCDs). Investigating whether a basophil activation test (BAT) with both venoms as well as with bromelain and horseradish peroxidase (HRP) or recombinant allergen-based IgE testing can improve the diagnostic procedure. Twenty-two Hymenoptera-venom allergic patients with sIgE antibodies to both bee and wasp venom were studied. sIgE antibodies to MUXF3 CCD, bromelain, HRP, rApi m 1, and rVes v 5 were determined, and a BAT (Flow2 CAST) with venom extracts, bromelain, and HRP was performed. Further recombinant allergen-based IgE testing was done by using an ELISA, if required. The reactivity of basophils was calculated from the insect venom concentration at half-maximum stimulation. Double positivity/double negativity/single positivity to rApi m 1 and rVes v 5 was seen in 12/1/9 patients. Further recombinant allergen-based IgE testing in the last ones revealed positive results to the other venom in all cases except one. BAT was double positive/double negative/single positive in 6/2/14 patients. Four patients with negative results in sIgE antibodies to CCDs had positive results in BAT. BAT with bromelain/HRP showed a sensitivity of 50%/81% and a specificity of 91%/90%. Component-resolved IgE testing elucidates the pattern of double positivity, showing a majority of true double sensitizations independent of CCD sensitization. BAT seems to add more information about the culprit insect even if the true clinical relevance of BAT is not completely determined because of ethical limitations on diagnostic sting challenges. BAT with HRP is a good method to determine sensitivity to CCDs. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Generation of a haptoglobin-hemoglobin complex-specific Fab antibody blocking the binding of the complex to CD163

DEFF Research Database (Denmark)

Horn, Ivo R; Nielsen, Marianne Jensby; Madsen, Mette

2003-01-01

During intravascular hemolysis hemoglobin (Hb) binds to haptoglobin (Hp) leading to endocytosis of the complex by the macrophage receptor, CD163. In the present study, we used a phage-display Fab antibody strategy to explore if the complex formation between Hp and Hb leads to exposure of antigenic...... epitopes specific for the complex. By Hp-Hb-affinity screening of a phage-Fab library, we isolated a phage clone against the ligand complex. Surface plasmon resonance analyses of the Fab part expressed as a recombinant protein revealed a high affinity binding (KD = 3.9 nm) to Hp-Hb, whereas no binding...... was measured for non-complexed Hp or Hb. The Fab antibody completely inhibited the binding of 125I-labeled Hp-Hb complexes to CD163 and blocked their uptake in CD163-transfected cells. In conclusion, we have raised a receptor-blocking antibody specifically recognizing the Hp-Hb complex. In addition to provide...

Low prevalence of antibodies and other plasma factors binding to CC chemokines and IL-2 in HIV-positive patients

DEFF Research Database (Denmark)

Meyer, C N; Svenson, M; Schade Larsen, C

2000-01-01

of HIV-infected patients were therefore assessed by radioimmunoassay and radioreceptor assay. IgG from 4/505 HIV patients and 9/2000 healthy controls (p>0.05) bound rMIP-1alpha and rMIP-1beta, but not rRANTES. No other plasma factors bound the chemokines. The antibodies inhibited receptor binding of both...... chemokines. There was no association between presence of antibodies and disease stage or HIV progression rate. Three of 11 patients treated with rIL-2 developed IgG antibodies suppressing cellular binding and growth promotion of rIL-2. Hence, circulating factors, including antibodies MIP-1alpha/MIP-1beta...

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

Recombinant pollen allergens from Dactylis glomerata: preliminary evidence that human IgE cross-reactivity between Dac g II and Lol p I/II is increased following grass pollen immunotherapy.

Science.gov (United States)

Roberts, A M; Van Ree, R; Cardy, S M; Bevan, L J; Walker, M R

1992-07-01

We previously described the isolation of three identical complementary DNA (cDNA) clones, constructed from Orchard/Cocksfoot grass (Dactylis glomerata) anther messenger RNA (mRNA), expressing a 140,000 MW beta-galactosidase fusion protein recognized by IgE antibodies in atopic sera. Partial nucleotide sequencing and inferred amino acid sequence showed greater than 90% homology with the group II allergen from Lolium perenne (Lol II) indicating they encode the group II equivalent, Dac g II. Western blot immunoprobing of recombinant lysates with rabbit polyclonal, mouse monoclonal and human polyclonal antisera demonstrates immunological identity between recombinant Dac g II, Lol p I and Lol p II. Similar cross-identity is observed with pollen extracts from three other grass species: Festuca rubra, Phleum pratense and Anthoxanthum odoratum. Recombinant Dac g II was recognized by species- and group-cross-reactive human IgE antibodies in 33% (4/12) of sera randomly selected from grass-sensitive individuals and in 67% (14/21) of sera from patients receiving grass pollen immunotherapy, whilst 0/4 sera from patients receiving venom immunotherapy alone contained Dac g II cross-reactive IgE. Cross-reactive IgG4 antibodies were detectable in 95% of sera from grass pollen immunotherapy patients. These preliminary data suggest that conventional grass pollen allergoid desensitization immunotherapy may induce IgE responses to a cross-reactive epitope(s) co-expressed by grass pollen groups I and II (and possibly group III) allergens.

B1 Cell IgE Impedes Mast Cell-Mediated Enhancement of Parasite Expulsion through B2 IgE Blockade

Directory of Open Access Journals (Sweden)

Rebecca K. Martin

2018-02-01

Full Text Available Helminth infection is known for generating large amounts of poly-specific IgE. Here we demonstrate that innate-like B1 cells are responsible for this IgE production during infection with the nematode parasites Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. In vitro analysis of B1 cell immunoglobulin class switch recombination to IgE demonstrated a requirement for anti-CD40 and IL-4 that was further enhanced when IL-5 was added or when the B1 source was helminth infected mice. An IL-25-induced upregulation of IgE in B1 cells was also demonstrated. In T cell-reconstituted RAG1−/− mice, N. brasiliensis clearance was enhanced with the addition of B2 cells in an IgE-dependent manner. This enhanced clearance was impeded by reconstitution with IgE sufficient B1 cells. Mucosal mast cells mediated the B2 cell enhancement of clearance in the absence of B1 cells. The data support B1 cell IgE secretion as a regulatory response exploited by the helminth.

IgE vs IgG4 epitopes of the peanut allergen Ara h 1 in patients with severe allergy

DEFF Research Database (Denmark)

Bøgh, Katrine Lindholm; Nielsen, H.; Eiwegger, T.

2013-01-01

to the allergen. However, recent studies have demonstrated the very importance of the IgG4-epitope affinity for the blocking ability. Studies comparing IgE and IgG4 binding epitopes mainly focus on the identification of linear epitopes. Peanut allergy is one of the most severe and persistent forms of food allergy....... The importance of conformational epitopes, of the major peanut allergen Ara h 1, has been demonstrated. The aim of this study was to compare Ara h 1-specific epitope patterns for IgE and IgG4 in patients with severe peanut allergy applying a method suitable to identify both linear and conformational epitopes....... Methods: Ara h 1-specific IgE and IgG4 epitope patterns were examined by competitive immunoscreening of a phage-displayed random 7-mer peptide library using polyclonal IgE and IgG4 from three individual patients suffering from severe peanut allergy. The resulting peptide sequences were mapped...

An efficiently cleaved HIV-1 clade C Env selectively binds to neutralizing antibodies.

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Saikat Boliar

Full Text Available An ideal HIV-1 Env immunogen is expected to mimic the native trimeric conformation for inducing broadly neutralizing antibody responses. The native conformation is dependent on efficient cleavage of HIV-1 Env. The clade B isolate, JRFL Env is efficiently cleaved when expressed on the cell surface. Here, for the first time, we report the identification of a native clade C Env, 4-2.J41 that is naturally and efficiently cleaved on the cell surface as confirmed by its biochemical and antigenic characteristics. In addition to binding to several conformation-dependent neutralizing antibodies, 4-2.J41 Env binds efficiently to the cleavage-dependent antibody PGT151; thus validating its native cleaved conformation. In contrast, 4-2.J41 Env occludes non-neutralizing epitopes. The cytoplasmic-tail of 4-2.J41 Env plays an important role in maintaining its conformation. Furthermore, codon optimization of 4-2.J41 Env sequence significantly increases its expression while retaining its native conformation. Since clade C of HIV-1 is the prevalent subtype, identification and characterization of this efficiently cleaved Env would provide a platform for rational immunogen design.

Conserved epitope on several human vitamin K-dependent proteins: location of the antigenic site and influence of metal ions on antibody binding

International Nuclear Information System (INIS)

Church, W.R.; Messier, T.; Howard, P.R.; Amiral, J.; Meyer, D.; Mann, K.G.

1988-01-01

A murine monoclonal antibody (designated H-11) produced by injecting mice with purified human protein C was found to bind several human vitamin K-dependent proteins. Using a solid-phase competitive radioimmunoassay with antibody immobilized onto microtiter plates, binding of 125 I-labeled protein C to the antibody was inhibited by increasing amounts of protein C, prothrombin, and Factors X and VII over a concentration range of 1 x 10 -8 to 1 x 10 -6 M. Chemical treatment of prothrombin with a variety of agents did not destroy the antigenic site recognized by the antibody as measured by immunoblotting of prothrombin or prothrombin derivative immobilized onto nitrocellulose. Immunoblotting of purified vitamin K-dependent polypeptides with the monoclonal antibody following sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretic transfer to nitrocellulose indicated that the antigenic site was found on the light chains of protein C and Factor X. The exact location of the antigenic determinant for antibody H-11 was established using synthetic peptides. Comparison of protein sequences of bovine and human vitamin K-dependent proteins suggests that the sequence Phe-Leu-Glu-Glu-Xaa-Arg/Lys is required for antibody binding. Increasing concentrations of Ca 2+ , Mg 2+ , or Mn 2+ partially inhibited binding of 125 I-protein C to the antibody in a solid-phase assay system with half-maximal binding observed at divalent metal ion concentrations of 2, 4, and 0.6 mM, respectively. The antigenic site thus recognized by monoclonal antibody H-11 is located at the amino-terminal region in the highly conserved γ-carboxyglutamic acid-containing domains of several, but not all, vitamin K-dependent proteins

Dynamics behind affinity maturation of an anti-HCMV antibody family influencing antigen binding

KAUST Repository

Di Palma, Francesco; Tramontano, Anna

2017-01-01

The investigation of antibody affinity maturation and its effects on antigen binding is important with respect to understanding the regulation of the immune response. To shed light on this crucial process, we analyzed two Igs neutralizing the human cytomegalovirus: the primary germline antibody M2J1 and its related mature antibody 8F9. Both antibodies target the AD-2S1 epitope of the gB envelope protein and are considered to establish similar interactions with the cognate antigen. We used molecular dynamics simulations to understand the effect of mutations on the antibody–antigen interactions. The results provide a qualitative explanation for the increased 8F9 peptide affinity compared with that of M2J1. The emerging atomistic-detailed description of these complexes reveals the molecular effects of the somatic hypermutations occurring during affinity maturation.

Dynamics behind affinity maturation of an anti-HCMV antibody family influencing antigen binding

KAUST Repository

Di Palma, Francesco

2017-08-03

The investigation of antibody affinity maturation and its effects on antigen binding is important with respect to understanding the regulation of the immune response. To shed light on this crucial process, we analyzed two Igs neutralizing the human cytomegalovirus: the primary germline antibody M2J1 and its related mature antibody 8F9. Both antibodies target the AD-2S1 epitope of the gB envelope protein and are considered to establish similar interactions with the cognate antigen. We used molecular dynamics simulations to understand the effect of mutations on the antibody–antigen interactions. The results provide a qualitative explanation for the increased 8F9 peptide affinity compared with that of M2J1. The emerging atomistic-detailed description of these complexes reveals the molecular effects of the somatic hypermutations occurring during affinity maturation.

Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine

International Nuclear Information System (INIS)

He Yuxian; Zhou Yusen; Liu Shuwen; Kou Zhihua; Li Wenhui; Farzan, Michael; Jiang Shibo

2004-01-01

The spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (CoV), a type I transmembrane envelope glycoprotein, consists of S1 and S2 domains responsible for virus binding and fusion, respectively. The S1 contains a receptor-binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. Here we show that a recombinant fusion protein (designated RBD-Fc) containing 193-amino acid RBD (residues 318-510) and a human IgG1 Fc fragment can induce highly potent antibody responses in the immunized rabbits. The antibodies recognized RBD on S1 domain and completely inhibited SARS-CoV infection at a serum dilution of 1:10,240. Rabbit antisera effectively blocked binding of S1, which contains RBD, to ACE2. This suggests that RBD can induce highly potent neutralizing antibody responses and has potential to be developed as an effective and safe subunit vaccine for prevention of SARS

Quantitative relationship between antibody affinity and antibody avidity

International Nuclear Information System (INIS)

Griswold, W.R.

1987-01-01

The relationship between antibody avidity, measured by the dissociation of the antigen-antibody bond in antigen excess, and antibody affinity was studied. Complexes of radiolabelled antigen and antibody of known affinity were prepared in vitro and allowed to stand for seven days to reach equilibrium. Then nonlabelled antigen in one hundred fold excess was added to dissociate the complexes. After an appropriate incubation the fraction of antigen bound to antibody was measured by the ammonium sulfate precipitation method. The dissociation index was the fraction bound in the experimental sample divided by the fraction bound in the control. The correlation coefficient between the dissociation index and the antibody binding constant was 0.92 for early dissociation and 0.98 for late dissociation. The regression equation relating the binding constant to the dissociation index was K = 6.4(DI) + 6.25, where DI is the late dissociation index and K is the logarithm to the base 10 of the binding constant. There is a high correlation between avidity and affinity of antibody. Antibody affinity can be estimated from avidity data. The stability of antigen-antibody complexes can be predicted from antibody affinity

Hymenoptera venom allergy: analysis of double positivity to honey bee and Vespula venom by estimation of IgE antibodies to species-specific major allergens Api m1 and Ves v5.

Science.gov (United States)

Müller, U R; Johansen, N; Petersen, A B; Fromberg-Nielsen, J; Haeberli, G

2009-04-01

In patients with hymenoptera venom allergy diagnostic tests are often positive with honey bee and Vespula venom causing problems in selection of venoms for immunotherapy. 100 patients each with allergic reactions to Vespula or honey bee stings and positive i.e. skin tests to the respective venom, were analysed for serum IgE to bee venom, Vespula venom and crossreacting carbohydrate determinants (CCDs) by UNICAP (CAP) and ADVIA Centaur (ADVIA). IgE-antibodies to species specific recombinant major allergens (SSMA) Api m1 for bee venom and Ves v5 for Vespula venom, were determined by ADVIA. 30 history and skin test negative patients served as controls. By CAP sensitivity was 1.0 for bee and 0.91 for Vespula venom, by ADVIA 0.99 for bee and 0.91 for Vespula venom. None of the controls were positive with either test. Double positivity was observed in 59% of allergic patients by CAP, in 32% by ADVIA. slgE to Api m1 was detected in 97% of bee and 17% of Vespula venom allergic patients, slgE to Ves v5 in 87% of Vespula and 17% of bee venom allergic patients. slgE to CCDs were present in 37% of all allergic patients and in 56% of those with double positivity and were more frequent in bee than in Vespula venom allergic patients. Double positivity of IgE to bee and Vespula venom is often caused by crossreactions, especially to CCDs. IgE to both Api m1 and Ves v5 indicates true double sensitization and immunotherapy with both venoms.

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

Are basophil histamine release and high affinity IgE receptor expression involved in asymptomatic skin sensitization?

DEFF Research Database (Denmark)

Jensen, Bettina Margrethe; Assing, K; Jensen, Lone Hummelshøj

2006-01-01

Immunoglobulin (Ig)E-sensitized persons with positive skin prick test, but no allergy symptoms, are classified as being asymptomatic skin sensitized (AS). The allergic type 1 disease is dependant on IgE binding to the high affinity IgE-receptor (FcepsilonRI) expressed on basophils and mast cells....

Characterisation of peptide microarrays for studying antibody-antigen binding using surface plasmon resonance imagery.

Directory of Open Access Journals (Sweden)

Claude Nogues

Full Text Available BACKGROUND: Non-specific binding to biosensor surfaces is a major obstacle to quantitative analysis of selective retention of analytes at immobilized target molecules. Although a range of chemical antifouling monolayers has been developed to address this problem, many macromolecular interactions still remain refractory to analysis due to the prevalent high degree of non-specific binding. We describe how we use the dynamic process of the formation of self assembling monolayers and optimise physical and chemical properties thus reducing considerably non-specific binding and allowing analysis of specific binding of analytes to immobilized target molecules. METHODOLOGY/PRINCIPAL FINDINGS: We illustrate this approach by the production of specific protein arrays for the analysis of interactions between the 65kDa isoform of human glutamate decarboxylase (GAD65 and a human monoclonal antibody. Our data illustrate that we have effectively eliminated non-specific interactions with the surface containing the immobilised GAD65 molecules. The findings have several implications. First, this approach obviates the dubious process of background subtraction and gives access to more accurate kinetic and equilibrium values that are no longer contaminated by multiphase non-specific binding. Second, an enhanced signal to noise ratio increases not only the sensitivity but also confidence in the use of SPR to generate kinetic constants that may then be inserted into van't Hoff type analyses to provide comparative DeltaG, DeltaS and DeltaH values, making this an efficient, rapid and competitive alternative to ITC measurements used in drug and macromolecular-interaction mechanistic studies. Third, the accuracy of the measurements allows the application of more intricate interaction models than simple Langmuir monophasic binding. CONCLUSIONS: The detection and measurement of antibody binding by the type 1 diabetes autoantigen GAD65 represents an example of an antibody

Isolation of a monoclonal antibody from a phage display library binding the rhesus macaque MHC class I allomorph Mamu-A1*001.

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Nathan Holman

Full Text Available Monoclonal antibodies that bind to human leukocyte antigen (HLA are useful tools for HLA-typing, tracking donor-recipient chimerisms after bone marrow transplants, and characterizing specific major histocompatibility complexes (MHC on cell surfaces. Unfortunately, equivalent reagents are not available for rhesus macaques, which are commonly used animal as models in organ transplant and infectious disease research. To address this deficiency, we isolated an antibody that recognizes the common Indian rhesus macaque MHC class I molecule, Mamu-A1*001. We induced Mamu-A1*001-binding antibodies by alloimmunizing a female Mamu-A1*001-negative rhesus macaque with peripheral blood mononuclear cells (PBMC from a male Mamu-A1*001-positive donor. A Fab phage display library was constructed with PBMC from the alloimmunized macaque and panned to isolate an antibody that binds to Mamu-A1*001 but not to other common rhesus macaque MHC class I molecules. The isolated antibody distinguishes PBMC from Mamu-A1*001-positive and -negative macaques. Additionally, the Mamu-A1*001-specific antibody binds the cynomolgus macaque MHC class I ortholog Mafa-A1*001:01 but not variants Mafa-A1*001:02/03, indicating a high degree of binding specificity. The Mamu-A1*001-specific antibody will be useful for identifying Mamu-A1*001-positive rhesus macaques, for detecting Mamu-A1*001-positive cells in populations of Mamu-A1*001-negative cells, and for examining disease processes that alter expression of Mamu-A1*001 on cell surfaces. Moreover, the alloimmunization process we describe will be useful for isolating additional MHC allomorph-specific monoclonal antibodies or antibodies against other polymorphic host proteins which are difficult to isolate with traditional technologies.

Omalizumab therapy in atopic dermatitis: depletion of IgE does not improve the clinical course - a randomized, placebo-controlled and double blind pilot study.

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Heil, Peter Maximilian; Maurer, Dieter; Klein, Brigitte; Hultsch, Thomas; Stingl, Georg

2010-12-01

Our understanding of the pathogenic role of IgE in atopic dermatitis is incomplete. We asked whether blocking free IgE would alter the course of the disease. We administered either omalizumab, a humanized monoclonal mouse antibody against IgE, or placebo subcutaneously for 16 weeks to 20 atopic dermatitis patients and measured immunological and clinical disease parameters. Omalizumab (I) reduced free serum IgE, (II) lowered surface IgE and FcɛRI expression on different peripheral blood mononuclear cells, (III) reduced the saturation of FcɛRI with IgE, (IV) increased the number of free FcɛRI and (V) lowered the number of IgE+, but not of FcɛRI+ cells in skin. The in vivo relevance of these results is evidenced by the increase in the threshold allergen concentration required to give a type I hypersensitivity reaction in the titrated skin test. While not significantly altering the clinical disease parameters, omalizumab treatment led to an improvement of the atopy patch test results in single patients, i.e. an eczematous reaction upon epicutaneous allergen challenge. The interference with immediate and delayed type skin tests may imply that a therapeutic benefit of omalizumab treatment, if present at all, would be seen in patients with acute rather than chronic forms of the disease. © The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.

Chloramine-T induced binding of monoclonal antibody B72. 3 to concanavalin-A

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Cole, W.C.; Jhingran, S.G. (Methodist Hospital, Houston, TX (United States) Baylor Coll. of Medicine, Houston, TX (United States))

1993-07-01

The effects of chloramine-T (CT) on monoclonal antibody B72.3 were studied with particular reference to Con-A lectin binding. After exposure to chloramine-T concentrations from 0.8 to 4.0 mg/mL (115-574 mol CT/mol B72.3), B72.3 showed progressive binding to agarose-linked Con-A. This behavior was paralleled by decreasing immunoreactivity and increasing fragmentation and aggregation of B72.3 demonstrated by SDS-PAGE and size exclusion HPLC. (Author).

Structure of an N276-Dependent HIV-1 Neutralizing Antibody Targeting a Rare V5 Glycan Hole Adjacent to the CD4 Binding Site

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Wibmer, Constantinos Kurt; Gorman, Jason; Anthony, Colin S.; Mkhize, Nonhlanhla N.; Druz, Aliaksandr; York, Talita; Schmidt, Stephen D.; Labuschagne, Phillip; Louder, Mark K.; Bailer, Robert T.; Karim, Salim S. Abdool; Mascola, John R.; Williamson, Carolyn; Moore, Penny L.; Kwong, Peter D.; Morris, Lynn (NHLS-South Africa); (NIH); (Witwatersrand); (KwaZulu-Natal)

2016-08-31

All HIV-1-infected individuals develop strain-specific neutralizing antibodies to their infecting virus, which in some cases mature into broadly neutralizing antibodies. Defining the epitopes of strain-specific antibodies that overlap conserved sites of vulnerability might provide mechanistic insights into how broadly neutralizing antibodies arise. We previously described an HIV-1 clade C-infected donor, CAP257, who developed broadly neutralizing plasma antibodies targeting an N276 glycan-dependent epitope in the CD4 binding site. The initial CD4 binding site response potently neutralized the heterologous tier 2 clade B viral strain RHPA, which was used to design resurfaced gp120 antigens for single-B-cell sorting. Here we report the isolation and structural characterization of CAP257-RH1, an N276 glycan-dependent CD4 binding site antibody representative of the early CD4 binding site plasma response in donor CAP257. The cocrystal structure of CAP257-RH1 bound to RHPA gp120 revealed critical interactions with the N276 glycan, loop D, and V5, but not with aspartic acid 368, similarly to HJ16 and 179NC75. The CAP257-RH1 monoclonal antibody was derived from the immunoglobulin-variable IGHV3-33 and IGLV3-10 genes and neutralized RHPA but not the transmitted/founder virus from donor CAP257. Its narrow neutralization breadth was attributed to a binding angle that was incompatible with glycosylated V5 loops present in almost all HIV-1 strains, including the CAP257 transmitted/founder virus. Deep sequencing of autologous CAP257 viruses, however, revealed minority variants early in infection that lacked V5 glycans. These glycan-free V5 loops are unusual holes in the glycan shield that may have been necessary for initiating this N276 glycan-dependent CD4 binding site B-cell lineage.

IMPORTANCEThe conserved CD4 binding site on gp120 is a major target for HIV-1 vaccine design, but key events in the elicitation and maturation of

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

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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

Fab-dsFv: A bispecific antibody format with extended serum half-life through albumin binding.

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Davé, Emma; Adams, Ralph; Zaccheo, Oliver; Carrington, Bruce; Compson, Joanne E; Dugdale, Sarah; Airey, Michael; Malcolm, Sarah; Hailu, Hanna; Wild, Gavin; Turner, Alison; Heads, James; Sarkar, Kaushik; Ventom, Andrew; Marshall, Diane; Jairaj, Mark; Kopotsha, Tim; Christodoulou, Louis; Zamacona, Miren; Lawson, Alastair D; Heywood, Sam; Humphreys, David P

2016-10-01

An antibody format, termed Fab-dsFv, has been designed for clinical indications that require monovalent target binding in the absence of direct Fc receptor (FcR) binding while retaining substantial serum presence. The variable fragment (Fv) domain of a humanized albumin-binding antibody was fused to the C-termini of Fab constant domains, such that the VL and VH domains were individually connected to the Cκ and CH1 domains by peptide linkers, respectively. The anti-albumin Fv was selected for properties thought to be desirable to ensure a durable serum half-life mediated via FcRn. The Fv domain was further stabilized by an inter-domain disulfide bond. The bispecific format was shown to be thermodynamically and biophysically stable, and retained good affinity and efficacy to both antigens simultaneously. In in vivo studies, the serum half-life of Fab-dsFv, 2.6 d in mice and 7.9 d in cynomolgus monkeys, was equivalent to Fab'-PEG.

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

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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

Identification of Aspergillus (A. flavus and A. niger) Allergens and Heterogeneity of Allergic Patients' IgE Response.

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Vermani, Maansi; Vijayan, Vannan Kandi; Agarwal, Mahendra Kumar

2015-08-01

Aspergillus species (A. flavus and A. niger) are important sources of inhalant allergens. Current diagnostic modalities employ crude Aspergillus extracts which only indicate the source to which the patient has been sensitized, without identifying the number and type of allergens in crude extracts. We report a study on the identification of major and minor allergens of the two common airborne Aspergillus species and heterogeneity of patients' IgE response to them. Skin prick tests were performed on 300 patients of bronchial asthma and/or allergic rhinitis and 20 healthy volunteers. Allergen specific IgE in patients' sera was estimated by enzyme allergosorbent test (EAST). Immunoblots were performed to identify major/minor allergens of Aspergillus extracts and to study heterogeneity of patients'IgE response to them. Positive cutaneous responses were observed in 17% and 14.7% of patients with A. flavus and A. niger extracts, respectively. Corresponding EAST positivity was 69.2% and 68.7%. In immunoblots, 5 allergenic proteins were identified in A. niger extract, major allergens being 49, 55.4 and 81.5 kDa. Twelve proteins bound patients' IgE in A. flavus extract, three being major allergens (13.3, 34 and 37 kDa). The position and slopes of EAST binding and inhibition curves obtained with individual sera varied from patient to patient. The number and molecular weight of IgE-binding proteins in both the Aspergillus extracts varied among patients. These results gave evidence of heterogeneity of patients' IgE response to major/minor Aspergillus allergens. This approach will be helpful to identify disease eliciting molecules in the individual patients (component resolved diagnosis) and may improve allergen-specific immunotherapy.

IgE and the role of the Radio-Allergo-Sorbent Test (RAST)

International Nuclear Information System (INIS)

Grond, K.

1976-01-01

In 1966 a new immunoglobulin was found in persons with allergies and in non-typical myeloma proteins. Normally this immunoglobulin E is present only in nanogramms and rests with predilection on the membrane of mast-cells. There is a reaginic-anaphylactic reaction after re-exposure of antigens to the antigen-antibody reaction followed by denudation of mediators of the anaphylactic reaction. With the Radio-Immuno-Sorbent-Test (RIST) the IgE can be quantitatively determined. Elevated IgE-blood levels are typically found in atopic eczema. With the Radio-Allergo-Sorbent-Test (RAST) the allergen specific IgE can be defined. A conformity with appropriate patchtests can be achieved in 60-80% of the cases. In this review advantoses and problem of RIST- and RAST-diagnoses are described. RAST presents a valuable aid in diagnosis of allergies beeing not burdensome and risky, as it is easy to perform and bears no risk to the patients. At the present time, however, patch tests are necessary in the diagnosis of allergies. (orig.) [de

Interleukin-7 (IL-7) enhances class switching to IgE and IgG4 in the presence of T cells via IL-9 and sCD23.

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Jeannin, P; Delneste, Y; Lecoanet-Henchoz, S; Gretener, D; Bonnefoy, J Y

1998-02-15

Interleukin-7 (IL-7) is a B-cell growth factor produced by both bone marrow stroma cells and follicular dendritic cells (FDCs) located in primary lymphoid follicles and germinal centers. In this study, we have evaluated the role of IL-7 on human Ig class switching. IL-7 was added to peripheral blood mononuclear cells (PBMCs) or tonsillar B cells in the absence or presence of IL-4 and/or anti-CD40 monoclonal antibody (MoAb). Alone, IL-7 did not affect Ig production by PBMCs or by anti-CD40 MoAb-stimulated B cells. Rather, IL-7 potentiated IL-4-induced IgE and IgG4 production by PBMCs. In parallel, IgG3 production was also enhanced but to a lesser extent, whereas the production of the other isotypes was unaltered. The activity of IL-2, IL-9, or IL-15, which share usage of the common gamma chain for signaling, was also assessed. IL-9, like IL-7, potentiated mainly IgE and IgG4 production by IL-4-stimulated PBMCs. IL-15, in contrast, was ineffective, whereas IL-2 enhanced the production of all isotypes. More precisely, IL-7 potentiation of IgE and IgG4 production required the presence of T cells and was accompanied by an increase of the expression of two soluble molecules favoring preferentially IgE and IgG4 synthesis: CD23 (sCD23) and IL-9. Moreover, neutralizing anti-CD23 and anti-IL-9 antibodies partly inhibited the increase of IgE synthesis induced by IL-7. Thus, IL-7 produced locally in the germinal centers by FDCs may interact with T cells and potentiate human IgE and IgG4 switching by favoring IL-9 and sCD23 production.

High-throughput screening of monoclonal antibodies against plant cell wall glycans by hierarchical clustering of their carbohydrate microarray binding profiles

DEFF Research Database (Denmark)

Moller, Isabel Eva; Marcus, Susan E.; Haeger, Ash

2008-01-01

Antibody-producing hybridoma cell lines were created following immunisation with a crude extract of cell wall polymers from the plant Arabidopsis thaliana. In order to rapidly screen the specificities of individual monoclonal antibodies (mAbs), their binding to microarrays containing 50 cell wall...... investigated using subsequent immunochemical and biochemical analyses and two novel mAbs are described in detail. mAb LM13 binds to an arabinanase-sensitive pectic epitope and mAb LM14, binds to an epitope occurring on arabinogalactan-proteins. Both mAbs display novel patterns of recognition of cell walls...

Simplifying complex sequence information: a PCP-consensus protein binds antibodies against all four Dengue serotypes.

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Bowen, David M; Lewis, Jessica A; Lu, Wenzhe; Schein, Catherine H

2012-09-14

Designing proteins that reflect the natural variability of a pathogen is essential for developing novel vaccines and drugs. Flaviviruses, including Dengue (DENV) and West Nile (WNV), evolve rapidly and can "escape" neutralizing monoclonal antibodies by mutation. Designing antigens that represent many distinct strains is important for DENV, where infection with a strain from one of the four serotypes may lead to severe hemorrhagic disease on subsequent infection with a strain from another serotype. Here, a DENV physicochemical property (PCP)-consensus sequence was derived from 671 unique sequences from the Flavitrack database. PCP-consensus proteins for domain 3 of the envelope protein (EdomIII) were expressed from synthetic genes in Escherichia coli. The ability of the purified consensus proteins to bind polyclonal antibodies generated in response to infection with strains from each of the four DENV serotypes was determined. The initial consensus protein bound antibodies from DENV-1-3 in ELISA and Western blot assays. This sequence was altered in 3 steps to incorporate regions of maximum variability, identified as significant changes in the PCPs, characteristic of DENV-4 strains. The final protein was recognized by antibodies against all four serotypes. Two amino acids essential for efficient binding to all DENV antibodies are part of a discontinuous epitope previously defined for a neutralizing monoclonal antibody. The PCP-consensus method can significantly reduce the number of experiments required to define a multivalent antigen, which is particularly important when dealing with pathogens that must be tested at higher biosafety levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

Senile amyloidosis and neuron binding antibody in the aging Syrian hamster

International Nuclear Information System (INIS)

Blumenthal, H.T.; Musacchia, X.J.

1985-01-01

The effects of age, sex, and irradiation on the genesis of amyloidosis, neuron-binding antibody (NBA), and the concomitant appearance of these two phenomena were studied in a colony of Syrian hamsters. In nonirradiated controls amyloidosis increased in prevalence with age after 12 months, and prevalence was higher in females than in males. Irradiation had the effect of advancing the appearance of amyloidosis to the 7-12 months group but did not intensify the amyloidotic process. IgG binding to the nucleus or cytoplasm of neurons was rare, and, despite the fact that IgM and IgA binding to these structures was present in about one-third of the animals, there was neither an aging nor an irradiation effect. The only statistically significant findings with respect to the concomitant occurrence of amyloid and NBA were negative correlations between nuclear IgM and IgA binding and amyloidosis. Of the various species thus far studied, the hamster is the first in which there has been no aging effect in respect to NBA

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

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Jin, Hongjun; Zangar, Richard C.

2017-01-17

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

Effect of iodination site on binding of radiolabeled ligand by insulin antibodies and insulin autoantibodies

International Nuclear Information System (INIS)

Diaz, J.L.; Wilkin, T.J.

1988-01-01

Four human insulins and four porcine insulins, each monoiodinated to the same specific activity at one of the four tyrosine residues (A14, A19, B16, B26) and purified by reversed-phase liquid chromatography, were tested in a radiobinding assay against a panel of insulin-antibody (IA)-positive sera from 10 insulin-treated diabetics and insulin-autoantibody-positive (IAA) sera from 10 nondiabetics. Of the 10 IAA-positive sera, five were fully cross reactive with both insulin species, and five were specific for human insulin. The rank order of binding of sera with the four ligands from each species was random for IA (mean rank values of 1.9 for A14, 2.0 for A19, 2.5 for B16, and 3.6 for B26 from a possible ranking range of 1 to 4), but more consistent for non-human-insulin-specific IAA (mean rank values 1.3 for A14, 3.8 for A19, 1.7 for B16, and 3.2 for B26 for labeled human insulins; 1.2 for A14, 4.0 for A19, 1.8 for B16, and 3.0 for B26 for labeled porcine insulins). The rank order of binding was virtually uniform for human-insulin-specific IAA (mean values 1.2 for A14, 3.0 for A19, 1.8 for B16, and 4.0 for B26). The influence of iodination site on the binding of labeled insulin appears to be dependent on the proximity of the labeled tyrosine to the antibody binding site and the clonal diversity, or restriction, of insulin-binding antibodies in the test serum. When IA and IAA are measured, the implications of this study regarding the choice of assay ligand may be important

Comparison of (/sup 125/I)beta-endorphin binding to rat brain and NG108-15 cells using a monoclonal antibody directed against the opioid receptor

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Bidlack, J.M.; O' Malley, W.E.; Schulz, R.

1988-02-01

The properties of (/sup 125/I)beta h-endorphin-binding sites from rat brain membranes and membranes from the NG108-15 cell line were compared using a monoclonal antibody directed against the opioid receptor and opioid peptides as probes. The binding of (/sup 125/I)beta h-endorphin to both rat brain and NG108-15 membranes yielded linear Scatchard plots with Kd values of 1.2 nM and 1.5 nM, respectively, and Bmax values of 865 fmol/mg rat brain membrane protein and 1077 fmol/mg NG108-15 membrane protein. A monoclonal antibody, OR-689.2.4, capable of inhibiting mu and delta binding but not kappa binding to rat brain membranes, noncompetitively inhibited the binding of 1 nM (/sup 125/I)beta h-endorphin to rat brain and NG108-15 membranes with an IC50 value of 405 nM for rat brain membranes and 543 nM for NG108-15 membranes. The monoclonal antibody also inhibited the binding of 3 nM (/sup 3/H) (D-penicillamine2, D-penicillamine5) enkephalin to NG108-15 membranes with an IC50 value of 370 nM. In addition to blocking the binding of (/sup 125/I)beta h-endorphin to brain membranes, the antibody also displaced (/sup 125/I)beta h-endorphin from membranes. Site-specific opioid peptides had large variations in their IC50 values depending on whether they were inhibiting (/sup 125/I)beta h-endorphin binding to rat brain or the NG108-15 membranes. When the peptides were tested with the monoclonal antibody for their combined ability to inhibit (/sup 125/I)beta h-endorphin binding to both membrane preparations, the peptides and antibody blocked binding as though they were acting at allosterically coupled sites, not two totally independent sites. These studies suggest that mu-, delta-, and beta-endorphin-binding sites share some sequence homology with the 35,000-dalton protein that the antibody is directed against.

IgE by itself affects mature rat mast cell preformed and de novo-synthesized mediator release and amplifies mast cell migratory response.

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Aleksandra Słodka

Full Text Available BACKGROUND: Immunoglobulin E (IgE binds to high affinity receptor FcεRI numerously expressed on mast cells. Recent findings have revealed that IgE by itself may regulate various aspects of mast cell biology, however, detailed data is still limited. METHODOLOGY/FINDINGS: Here, we have examined the influence of IgE alone, used at different concentrations, on mast cell activity and releasability. For the study we have employed in vivo differentiated mature tissue mast cells isolated from rat peritoneal cavity. Mast cells were exposed to IgE alone and then the release of preformed and de novo-synthesized mediators, surface FcεRI expression and mast cell migratory response were assessed. IgE by itself was found to up-regulate FcεRI expression and activate mast cells to degranulation, as well as de novo synthesis and release of cysteinyl leukotrienes and TNF. We have provided evidence that IgE alone also amplified spontaneous and CCL5- or TNF-induced migration of mast cells. Importantly, IgE was effective only at concentrations ≥ 3 µg/mL. A molecular basis investigation using an array of specific inhibitors showed that Src kinases, PLC/PLA2, MAP kinases (ERK and p38 and PI3K were entirely or partially involved in IgE-induced mast cell response. Furthermore, IgE alone stimulated the phosphorylation of MAP kinases and PI3K in rat mast cells. CONCLUSION: Our results clearly demonstrated that IgE by itself, at higher concentrations, influences mast cell activity and releasability. As there are different conditions when the IgE level is raised it might be supposed that in vivo IgE is one of the important factors modulating mast cell biology within tissues.

MAST CELLS, MAST/STEM CELL GROWTH FACTOR RECEPTOR (C-KIT/CD117 AND IGE MAY BE INTEGRAL TO THE PATHOGENESIS OF ENDEMIC PEMPHIGUS FOLIACEUS

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Ana Maria Roselino

2013-11-01

Full Text Available Introduction: Pemphigus foliaceus (PF is endemic in some South American countries, especially in Colombia and Brazil; in Brazil, it is also known as fogo selvagem (FS. We aimed to study the presence of mast cells and the expression of the mast/stem cell growth factor receptor (c-kit/CD117 in PF skin biopsies, as well as the role of IgE in the disease pathogenesis. Methods: Forty-four skin biopsies from patients affected by endemic PF (EPF (30 patients from El Bagre, Colombia, and 14 from the northeastern region of São Paulo State, Brazil, 48 control biopsies from Colombian and Brazilian endemic areas, and additional control biopsies from none endemic areas in Colombia and the USA non were studied. Immunohistochemistry (IHC was performed to evaluate skin biopsies with anti-mast cell tryptase (MCT, anti-c-kit and anti-IgE antibodies. We also searched for serum IgE in 30 EPF and 30 non-atopic controls from the El Bagre region via ELISA. In our El Bagre patients and controls, we also searched for IgE in skin samples by direct immunofluorescence. Results: In 100% of the EPF biopsies, MCT, c-kit and IgE were identified with stronger expression relative to control biopsies, especially in the inflammatory infiltrates around upper dermal blood vessels and dermal eccrine glands. IgE staining was positive along the BMZ in some EPF skin samples. The DIF results confirmed a linear deposition of IgE at the BMZ. Increased IgE serum levels were also noted in PF patients relative to controls.. Conclusions: In patients with EPF, the observed increased expression of MCT, c-kit and IgE in lesional skin, associated with higher serum IgE levels may indicate possible IgE participation in the antigenic response.

Association between the MHC gene region and variation of serum IgE levels against specific mould allergens in the horse

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Curik Ino

2003-06-01

Full Text Available Abstract To investigate whether the equine major histocompatibility complex (MHC gene region influences the production of mould-specific immunoglobulin E antibodies (IgE, alleles of the equine leukocyte antigen (ELA-A locus and three microsatellite markers (UM-011, HTG-05 and HMS-42 located on the same chromosome as the equine MHC were determined in 448 Lipizzan horses. Statistical analyses based on composite models, showed significant associations of the ELA-A and UM-011 loci with IgE titres against the recombinant Aspergillus fumigatus 7 antigen (rAsp f 7. UM-011 was also significantly associated with IgE titres against the recombinant Aspergillus fumigatus 8 antigen (rAsp f 8. In addition to the loci mentioned above, the MHC class II DQA and DRA loci were determined in 76 Lipizzans from one stud. For IgE levels against rAsp f 7, the composite model showed the strongest association for DQA (P rAsp f 8 specific IgE levels, similarly to the results found with all 448 horses, the strongest association was found with UM-011 (P = 0.01, which is closely linked with the MHC class II DRB locus. These results suggest that the equine MHC gene region and possibly MHC class II loci, influence the specific IgE response in the horse. However, although the strongest associations were found with DQA and UM-011, this study did not distinguish if the observed effects were due to the MHC itself or to other tightly linked genes.

Study of the epitope structure of purified Dac G I and Lol p I, the major allergens of Dactylis glomerata and Lolium perenne pollens, using monoclonal antibodies.

Science.gov (United States)

Mourad, W; Mécheri, S; Peltre, G; David, B; Hébert, J

1988-11-15

The use of mAb allowed us to further analyze the cross-reactivity between purified Dac g I and Lol p I, the major allergens of Dactylis glomerata (cocksfoot) and Lolium perenne (Rye grass), respectively. It was first shown, using IEF, followed by immunoprinting, that serum IgE antibodies from most grass-sensitive patients recognize both Dac g I and Lol p I. Second, three different anti-Lol p I mAb, 290A-167, 348A-6, and 539A-6, and one anti-Dac g I mAb, P3B2 were all shown to react with Dac g I and Lol p I, indicating that the two molecules share common epitopes. Epitope specificity of the mAb was determined by competitive binding inhibition of a given labeled mAb to solid phase fixed Dac g I or Lol p I by the mAb. The results indicated that the four mAb are directed against four different and non-overlapping epitopes present on both allergens. Using double-binding RIA, our data strongly suggest that the common epitopes are not repetitive on both molecules. In addition to their similar physicochemical characteristics, such as isolectric points and m.w., Dac g I and Lol p I share four identical epitopes. Binding inhibition of human IgE to Lol p I and Dac g I by the mAb was also assessed. The results indicated that each mAb was able to inhibit such reactions to variable degree but no additive inhibition was observed when two mAb of different specificities were used in combination, suggesting that the human IgE binding site is partially shared by each epitope recognized by the four mAb.

Covalent Binding of Antibodies to Cellulose Paper Discs and Their Applications in Naked-eye Colorimetric Immunoassays.

Science.gov (United States)

Peng, Yanfen; Gelder, Victor Van; Amaladoss, Anburaj; Patel, Kadamb Haribhai

2016-10-21

This report presents two methods for the covalent immobilization of capture antibodies on cellulose filter paper grade No. 1 (medium-flow filter paper) discs and grade No. 113 (fast-flow filter paper) discs. These cellulose paper discs were grafted with amine functional groups through a silane coupling technique before the antibodies were immobilized on them. Periodate oxidation and glutaraldehyde cross-linking methods were used to graft capture antibodies on the cellulose paper discs. In order to ensure the maximum binding capacity of the capture antibodies to their targets after immobilization, the effects of various concentrations of sodium periodate, glutaraldehyde, and capture antibodies on the surface of the paper discs were investigated. The antibodies that were coated on the amine-functionalized cellulose paper discs through a glutaraldehyde cross-linking agent showed enhanced binding activity to the target when compared to the periodate oxidation method. IgG (in mouse reference serum) was used as a reference target in this study to test the application of covalently immobilized antibodies through glutaraldehyde. A new paper-based, enzyme-linked immunosorbent assay (ELISA) was successfully developed and validated for the detection of IgG. This method does not require equipment, and it can detect 100 ng/ml of IgG. The fast-flow filter paper was more sensitive than the medium-flow filter paper. The incubation period of this assay was short and required small sample volumes. This naked-eye, colorimetric immunoassay can be extended to detect other targets that are identified with conventional ELISA.

Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition

DEFF Research Database (Denmark)

Green, M R; Couchman, J R

1985-01-01

, the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing......Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map...... whether EGF-R1 could recognize molecules unrelated to the EGF receptor, the EGF binding and EGF-R1 recognition profiles were compared on cultures of SVK14 cells, a SV40 transformed human keratinocyte cell line. EGF binding and EGF-R1 monoclonal antibody distribution on these cells was found to be similar...

Epitopes in α8β1 and other RGD-binding integrins delineate classes of integrin-blocking antibodies and major binding loops in α subunits.

Science.gov (United States)

Nishimichi, Norihisa; Kawashima, Nagako; Yokosaki, Yasuyuki

2015-09-09

Identification of epitopes for integrin-blocking monoclonal antibodies (mAbs) has aided our understanding of structure-function relationship of integrins. We mapped epitopes of chicken anti-integrin-α8-subunit-blocking mAbs by mutational analyses, examining regions that harboured all mapped epitopes recognized by mAbs against other α-subunits in the RGD-binding-integrin subfamily. Six mAbs exhibited blocking function, and these mAbs recognized residues on the same W2:41-loop on the top-face of the β-propeller. Loop-tips sufficiently close to W2:41 (face was identified as an additional component of the epitope of one antibody, clone YZ5. Binding sequences on the two loops were conserved in virtually all mammals, and that on W3:34 was also conserved in chickens. These indicate 1) YZ5 binds both top and bottom loops, and the binding to W3:34 is by interactions to conserved residues between immunogen and host species, 2) five other blocking mAbs solely bind to W2:41 and 3) the α8 mAbs would cross-react with most mammals. Comparing with the mAbs against the other α-subunits of RGD-integrins, two classes were delineated; those binding to "W3:34 and an top-loop", and "solely W2:41", accounting for 82% of published RGD-integrin-mAbs.

Utility of serum periostin and free IgE levels in evaluating responsiveness to omalizumab in patients with severe asthma.

Science.gov (United States)

Tajiri, T; Matsumoto, H; Gon, Y; Ito, R; Hashimoto, S; Izuhara, K; Suzukawa, M; Ohta, K; Ono, J; Ohta, S; Ito, I; Oguma, T; Inoue, H; Iwata, T; Kanemitsu, Y; Nagasaki, T; Niimi, A; Mishima, M

2016-10-01

Omalizumab, a humanized anti-IgE monoclonal antibody, has demonstrated efficacy in patients with severe allergic asthma. However, treatment responses vary widely among individuals. Despite a lack of data, free serum IgE levels following omalizumab treatment have been proposed as a marker of treatment responsiveness. In this prospective, observational study, we assessed the utility of biomarkers of type 2 inflammation in predicting omalizumab treatment responses, as determined by the absence of asthma exacerbation during the first year of treatment. Free serum IgE levels were monitored for 2 years to examine their association with baseline biomarker levels and the number of exacerbations. We enrolled thirty patients who had been treated with omalizumab for at least 1 year, of whom 27 were treated for 2 years. Baseline serum periostin levels and blood eosinophil counts were significantly higher in patients without exacerbations during the first year of treatment than in patients with exacerbations. Baseline serum periostin levels, but not eosinophil counts, were negatively associated with free serum IgE levels after 16 or 32 weeks of treatment. Reduced free serum IgE levels during treatment from those at baseline were associated with reduced exacerbation numbers at 2 years. In 14 patients who continued to have exacerbations during the first year of treatment, exacerbation numbers gradually and significantly decreased over the 2-year study period, with concurrent significant reductions in free serum IgE levels. Baseline serum periostin levels and serum free IgE levels during treatment follow-up may be useful in evaluating responses to omalizumab treatment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Ala12]MCD peptide: a lead peptide to inhibitors of immunoglobulin E binding to mast cell receptors.

Science.gov (United States)

Buku, A; Condie, B A; Price, J A; Mezei, M

2005-09-01

An effort was made to discover mast cell degranulating (MCD) peptide analogs that bind with high affinity to mast cell receptors without triggering secretion of histamine or other mediators of the allergic reaction initiated by immunoglobulin E (IgE) after mast cell activation. Such compounds could serve as inhibitors of IgE binding to mast cell receptors. An alanine scan of MCD peptide reported previously showed that the analog [Ala12]MCD was 120-fold less potent in histamine-releasing activity and fivefold more potent in binding affinity to mast cell receptors than the parent MCD peptide. Because this analog showed marginal intrinsic activity and good binding affinity it was subsequently tested in the present study as an IgE inhibitor. In contrast to MCD peptide, [Ala12]MCD showed a 50% inhibition of IgE binding to the Fc epsilon RI alpha mast cell receptor by using rat basophilic leukemia (RBL-2H3) mast cells and fluorescence polarization. Furthermore, in a beta-hexosaminidase secretory assay, the peptide also showed a 50% inhibition of the secretion of this enzyme caused by IgE. An attempt was made to relate structural changes and biologic differences between the [Ala12]MCD analog and the parent MCD peptide. The present results show that [Ala12]MCD may provide a base for designing agents to prevent IgE/Fc epsilon RI alpha interactions and, consequently, allergic conditions.

Sequence homology: A poor predictive value for profilins cross-reactivity

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Pazouki Nazanin

2005-09-01

Full Text Available Summary Background Profilins are highly cross-reactive allergens which bind IgE antibodies of almost 20% of plant-allergic patients. This study is aimed at investigating cross-reactivity of melon profilin with other plant profilins and the role of the linear and conformational epitopes in human IgE cross-reactivity. Methods Seventeen patients with melon allergy were selected based on clinical history and a positive skin prick test to melon extract. Melon profilin has been cloned and expressed in E. coli. The IgE binding and cross-reactivity of the recombinant profilin were measured by ELISA and inhibition ELISA. The amino acid sequence of melon profilin was compared with other profilin sequences. A combination of chemical cleavage and immunoblotting techniques were used to define the role of conformational and linear epitopes in IgE binding. Comparative modeling was used to construct three-dimensional models of profilins and to assess theoretical impact of amino acid differences on conformational structure. Results Profilin was identified as a major IgE-binding component of melon. Alignment of amino acid sequences of melon profilin with other profilins showed the most identity with watermelon profilin. This melon profilin showed substantial cross-reactivity with the tomato, peach, grape and Cynodon dactylon (Bermuda grass pollen profilins. Cantaloupe, watermelon, banana and Poa pratensis (Kentucky blue grass displayed no notable inhibition. Our experiments also indicated human IgE only react with complete melon profilin. Immunoblotting analysis with rabbit polyclonal antibody shows the reaction of the antibody to the fragmented and complete melon profilin. Although, the well-known linear epitope of profilins were identical in melon and watermelon, comparison of three-dimensional models of watermelon and melon profilins indicated amino acid differences influence the electric potential and accessibility of the solvent-accessible surface of

B1 Cell IgE Impedes Mast Cell-Mediated Enhancement of Parasite Expulsion through B2 IgE Blockade

OpenAIRE

Rebecca K. Martin; Sheela R. Damle; Yolander A. Valentine; Matthew P. Zellner; Briana N. James; Joseph C. Lownik; Andrea J. Luker; Elijah H. Davis; Martha M. DeMeules; Laura M. Khandjian; Fred D. Finkelman; Joseph F. Urban, Jr.; Daniel H. Conrad

2018-01-01

Helminth infection is known for generating large amounts of poly-specific IgE. Here we demonstrate that innate-like B1 cells are responsible for this IgE production during infection with the nematode parasites Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. In vitro analysis of B1 cell immunoglobulin class switch recombination to IgE demonstrated a requirement for anti-CD40 and IL-4 that was further enhanced when IL-5 was added or when the B1 source was helminth infected mi...

Serum IgE levels in patients with intracranial tumors

Directory of Open Access Journals (Sweden)

George A Alexiou

2015-03-01

Full Text Available Aim: Several epidemiological studies have shown an inverse correlation between allergy and brain cancer. The purpose of this study was to compare the serum IgE levels between patients with gliomas and nonglial tumors and their possible prognostic role. Methods: A total of 84 patients with intracranial tumors were included in this study. At clinical presentation, estimation of serum IgE levels was assessed by nephelometry. Detailed information regarding the history of allergies was collected by interview. Results: Of the 84 cases, 42 were gliomas, 23 were meningiomas, 16 were metastases and 3 were primary central nervous system lymphomas. Patients with high-grade glioma had lower IgE levels than patients with low-grade glioma. Patients with glioma and meningioma had statistical significant lower serum IgE levels than patients with metastases. Patients with glioblastoma with serum IgE levels greater than 24 U/mL had a better survival. Conclusion: Patients with glioma and meningioma had lower IgE levels than patients with metastatic lesions. A prognostic role of serum IgE levels was found in glioblastoma. Further studies in larger patient series are required in order to verify our preliminary observations.

Broad and potent HIV-1 neutralization by a human antibody that binds the gp41-gp120 interface

Energy Technology Data Exchange (ETDEWEB)

Huang, Jinghe; Kang, Byong H.; Pancera, Marie; Lee, Jeong Hyun; Tong, Tommy; Feng, Yu; Imamichi, Hiromi; Georgiev, Ivelin S.; Chuang, Gwo-Yu; Druz, Aliaksandr; Doria-Rose, Nicole A.; Laub, Leo; Sliepen, Kwinten; van Gils, Marit J.; de la Peña, Alba Torrents; Derking, Ronald; Klasse, Per-Johan; Migueles, Stephen A.; Bailer, Robert T.; Alam, Munir; Pugach, Pavel; Haynes, Barton F.; Wyatt, Richard T.; Sanders, Rogier W.; Binley, James M.; Ward, Andrew B.; Mascola, John R.; Kwong, Peter D.; Connors, Mark [NIH

2015-10-15

The isolation of human monoclonal antibodies is providing important insights into the specificities that underlie broad neutralization of HIV-1 (reviewed in ref. 1). Here we report a broad and extremely potent HIV-specific monoclonal antibody, termed 35O22, which binds a novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with a half-maximum inhibitory concentration (IC₅₀) <50 μg ml^-1. The median IC₅₀ of neutralized viruses was 0.033 μg ml^-1, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and a reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed that it bound to a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current monoclonal-antibody-based approaches to immunotherapies, prophylaxis and vaccine design.

Omalizumab: an anti-immunoglobulin E antibody for the treatment of allergic respiratory diseases

Directory of Open Access Journals (Sweden)

J. Bousquet

2008-04-01

Full Text Available Immunoglobulin E (IgE is central to the development of allergic diseases. Cross-linking of cell-bound IgE by the allergen leads to the initiation of the inflammatory cascade. Omalizumab, an anti-IgE antibody, forms complexes with free IgE, thereby inhibiting the allergic reaction before its commencement. A survey of the clinical trials performed on omalizumab indicated that this anti-IgE antibody is efficacious and well tolerated in the treatment of separate and concomitant asthma and rhinitis. In patients with poorly controlled asthma, omalizumab reduced the asthma exacerbation and emergency visit rate, along with improving the quality of life. The improvement in asthma control was associated with a reduction of inhaled and oral corticosteroids. Improved nasal symptom scores and a reduced need for antihistamines were observed in patients with allergic rhinitis. Omalizumab was also proven to be effective as an add-on therapy for concomitant asthma and rhinitis. In conclusion, omalizumab provides an integrated approach for the treatment and management of allergic respiratory diseases.

Total and Candida - Specific IgE in Recurrent Vaginal Candidiasis

Directory of Open Access Journals (Sweden)

K V Ratnam

1987-01-01

Full Text Available Total and candida specific serum IgE levels were studied in 21 patients who fulfilled the criteria for recurrent vaginal candidiasis, and 45 controls. The candida specific IgE levels were significantly higher in patients with recurrent vaginal candidiasis when compared with the controls. There was no significant difference in the total IgE levels between patients and the controls. IgE is postulated to inhibit the cellular immune respsnse to candida and thereby prevent its eradication. There may be a genetic basis for the increased IgE levels.

Anti-idiotypes to anti-Lolp I (Rye) antibodies in allergic and non-allergic individuals. Influence of immunotherapy.

Science.gov (United States)

Bose, R; Marsh, D G; Delespesse, G

1986-01-01

Anti-idiotypes (aId) reacting with anti-Lol I (Lolp I; Rye I) antibodies were detected by their ability to bind to radioiodinated F(ab')2 anti-Lol I. Sera were tested after removal of anti-Lol I and anti-heavy and light chain activity by adsorption on Lol I-Sepharose 4B and normal human serum Sepharose 4B. The binding of aId to Id was inhibited by affinity purified anti-Lol I but not by certain unrelated immunoglobulins; in some sera this binding was also inhibited by Lol I. The levels of aId were measured in serial bleedings collected over a 1 year period from Lol I-sensitive patients, allergic donors not sensitive to Lol I and non-allergic persons. In Lol I-allergic patients the levels of aId were significantly influenced by seasonal exposure to pollen and by immunotherapy with extracts of grass pollen. Moreover, in 12 out of 16 cases, there was also a significant inverse relationship between changes in serum levels of aId and of IgG or IgE anti-Lol I. Most interestingly, aId were also detected in non-allergic individuals; in this case, the levels of aId were not influenced by the pollen season. The data suggest that Id-aId interactions may play a role in the regulation of anti-Lol I antibody production. PMID:3492316

Carbon-13 NMR study of switch variant anti-dansyl antibodies: Antigen binding and domain-domain interactions

International Nuclear Information System (INIS)

Kato, Koichi; Matsunaga, Chigusa; Odaka, Asano; Yamato, Sumie; Takaha, Wakana; Shimada, Ichio; Arata, Yoji

1991-01-01

A 13 C NMR study is reported of switch variant anti-dansyl antibodies, which possess the identical V H , V L , and C L domains in conjunction with highly homologous but not identical heavy-chain constant regions. Each of the antibodies has been selectively labeled with 13 C at the carbonyl carbon of Trp, Tyr, His, or Cys residue by growing hybridoma cells in serum-free medium. Spectral assignments have been made by folowing the procedure described previously for the switch variant antibodies labeled with [1- 13 C]Met. On the basis of the spectral data collected for the antibodies and their proteolytic fragments, the authors discuss how 13 C NMR spectroscopy can be used for the structural analyses of antigen binding and also of domain-domain interactions in the antibody molecule

Analytical criteria for performance characteristics of IgE binding methods for evaluating safety of biotech food products

NARCIS (Netherlands)

Holzhauser, Thomas; van Ree, Ronald; Poulsen, Lars K.; Bannon, Gary A.

2008-01-01

There is detailed guidance on how to perform bioinformatic analyses and enzymatic degradation studies for genetically modified crops under consideration for approval by regulatory agencies; however, there is no consensus in the scientific community on the details of how to perform IgE serum studies.

Construction of hevein (Hev b 6.02) with reduced allergenicity for immunotherapy of latex allergy by comutation of six amino acid residues on the conformational IgE epitopes.

Science.gov (United States)

Karisola, Piia; Mikkola, Jari; Kalkkinen, Nisse; Airenne, Kari J; Laitinen, Olli H; Repo, Susanna; Pentikäinen, Olli T; Reunala, Timo; Turjanmaa, Kristiina; Johnson, Mark S; Palosuo, Timo; Kulomaa, Markku S; Alenius, Harri

2004-02-15

Recently we have established that IgE Abs bind to conformational epitopes in the N- and C-terminal regions of the major natural rubber latex allergen, hevein (Hev b 6.02). To identify the critical amino acid residues that interact with IgE, the hevein sequence was scanned by using site-specific mutations. Twenty-nine hevein mutants were designed and produced by a baculovirus expression system in insect cells and tested by IgE inhibition-ELISA using sera from 26 latex allergic patients. Six potential IgE-interacting residues of hevein (Arg(5), Lys(10), Glu(29), Tyr(30), His(35), and Gln(38)) were identified and characterized further in detail. Based on these six residues, two triple mutants (Hdelta3A, Hdelta3B) and hevein mutant where all six residues were mutated (Hdelta6), were designed, modeled, and produced. Structural and functional properties of these combinatory mutants were compared experimentally and in silico with those of recombinant hevein. The IgE-binding affinity of the mutants decreased by three to five orders of magnitude as compared with that of recombinant hevein. Skin prick test reactivity of the triple mutant HDelta3A was drastically reduced and that of the six-residue mutant Hdelta6 was completely abolished in all patients examined in this study. The approach presented in this paper offers tools for identification and modification of amino acid residues on conformational epitopes of allergens that interact with IgE. Hevein with a highly reduced ability to bind IgE should provide a valuable candidate molecule for immunotherapy of latex allergy and is anticipated to have a low risk of systemic side effects.

Identification of antibody glycosylation structures that predict monoclonal antibody Fc-effector function.

Science.gov (United States)

Chung, Amy W; Crispin, Max; Pritchard, Laura; Robinson, Hannah; Gorny, Miroslaw K; Yu, Xiaojie; Bailey-Kellogg, Chris; Ackerman, Margaret E; Scanlan, Chris; Zolla-Pazner, Susan; Alter, Galit

2014-11-13

To determine monoclonal antibody (mAb) features that predict fragment crystalizable (Fc)-mediated effector functions against HIV. Monoclonal antibodies, derived from Chinese hamster ovary cells or Epstein-Barr virus-immortalized mouse heteromyelomas, with specificity to key regions of the HIV envelope including gp120-V2, gp120-V3 loop, gp120-CD4(+) binding site, and gp41-specific antibodies, were functionally profiled to determine the relative contribution of the variable and constant domain features of the antibodies in driving robust Fc-effector functions. Each mAb was assayed for antibody-binding affinity to gp140(SR162), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and for the ability to bind to FcγRIIa, FcγRIIb and FcγRIIIa receptors. Antibody glycan profiles were determined by HPLC. Neither the specificity nor the affinity of the mAbs determined the potency of Fc-effector function. FcγRIIIa binding strongly predicted ADCC and decreased galactose content inversely correlated with ADCP, whereas N-glycolylneuraminic acid-containing structures exhibited enhanced ADCP. Additionally, the bi-antenary glycan arm onto which galactose was added predicted enhanced binding to FcγRIIIa and ADCC activity, independent of the specificity of the mAb. Our studies point to the specific Fc-glycan structures that can selectively promote Fc-effector functions independently of the antibody specificity. Furthermore, we demonstrated antibody glycan structures associated with enhanced ADCP activity, an emerging Fc-effector function that may aid in the control and clearance of HIV infection.

Increases in IgE, Eosinophils, and Mast Cells Can be Used in Diagnosis and to Predict Relapse of IgG4-Related Disease.

Science.gov (United States)

Culver, Emma L; Sadler, Ross; Bateman, Adrian C; Makuch, Mateusz; Cargill, Tamsin; Ferry, Berne; Aalberse, Rob; Barnes, Eleanor; Rispens, Theo

2017-09-01

IgG subclass 4-related disease (IgG4-RD) is characterized by increased serum levels of IgG4 and infiltration of biliary, pancreatic, and other tissues by IgG4-positive plasma cells. We assessed the prevalence of allergy and/or atopy, serum, and tissue IgE antibodies, and blood and tissue eosinophils in patients with IgG4-RD. We investigated the association between serum IgE and diagnosis and relapse of this disease. We performed a prospective study of 48 patients with IgG4-RD, 42 patients with an increased serum level of IgG4 with other inflammatory and autoimmune conditions (disease control subjects), and 51 healthy individuals (healthy control subjects) recruited from Oxford, United Kingdom from March 2010 through March 2014, and followed for a median of 41 months (range, 3-73 months). Serum levels of immunoglobulin were measured at diagnosis, during steroid treatment, and at disease relapse for patients with IgG4-RD; levels at diagnosis were compared with baseline levels of control subjects. Allergen-specific IgEs were measured using the IgE ImmunoCAP. Levels and distribution of IgG4 and IgE antibodies in lymphoid, biliary, and pancreatic tissues from patients with IgG4-RD and disease control subjects were measured by immunohistochemistry. We analyzed data using the Spearman rank correlation and receiver operating characteristic curves. Serum levels of IgG4 increased to 1.4 g/L or more, and IgE increased to 125 kIU/L or more, in 81% and 54% of patients with IgG4-RD, respectively, compared with 6% and 16% of healthy control subjects (P IgG4-RD versus 9% of healthy control subjects (P = .004). Of patients with IgG4-RD, 63% had a history of allergy and 40% had a history of atopy with an IgE-specific response; these values were 60% and 53% in patients with increased serum levels of IgE (P 480 kIU/L distinguished patients with IgG4-RD from disease control subjects with 86% specificity, 36% sensitivity, and a likelihood ratio of 3.2. Level of IgE at diagnosis >380 k

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.

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

International Nuclear Information System (INIS)

Aalberse, R.C.; Amsterdam Univ.

1978-01-01

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

Carbon-13 NMR study of switch variant anti-dansyl antibodies: Antigen binding and domain-domain interactions

Energy Technology Data Exchange (ETDEWEB)

Kato, Koichi; Matsunaga, Chigusa; Odaka, Asano; Yamato, Sumie; Takaha, Wakana; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo (Japan))

1991-07-02

A {sup 13}C NMR study is reported of switch variant anti-dansyl antibodies, which possess the identical V{sub H}, V{sub L}, and C{sub L} domains in conjunction with highly homologous but not identical heavy-chain constant regions. Each of the antibodies has been selectively labeled with {sup 13}C at the carbonyl carbon of Trp, Tyr, His, or Cys residue by growing hybridoma cells in serum-free medium. Spectral assignments have been made by folowing the procedure described previously for the switch variant antibodies labeled with (1-{sup 13}C)Met. On the basis of the spectral data collected for the antibodies and their proteolytic fragments, the authors discuss how {sup 13}C NMR spectroscopy can be used for the structural analyses of antigen binding and also of domain-domain interactions in the antibody molecule.

IgE production by normal human lymphocytes is induced by interleukin 4 and suppressed by interferons gamma and alpha and prostaglandin E2

NARCIS (Netherlands)

Pène, J.; Rousset, F.; Brière, F.; Chrétien, I.; Bonnefoy, J. Y.; Spits, H.; Yokota, T.; Arai, N.; Arai, K.; Banchereau, J.

1988-01-01

The effect of human recombinant interleukin 4 (IL-4) on antibody production by normal peripheral blood mononuclear cells enriched for B cells was investigated. IL-4 preferentially induced IgE synthesis in vitro. In addition, a low induction of IgG production was observed, whereas IL-4 had no effect

IgE recognition of chimeric isoforms of the honeybee (Apis mellifera) venom allergen Api m 10 evaluated by protein array technology.

Science.gov (United States)

Van Vaerenbergh, Matthias; De Smet, Lina; Rafei-Shamsabadi, David; Blank, Simon; Spillner, Edzard; Ebo, Didier G; Devreese, Bart; Jakob, Thilo; de Graaf, Dirk C

2015-02-01

Api m 10 has recently been established as novel major allergen that is recognized by more than 60% of honeybee venom (HBV) allergic patients. Previous studies suggest Api m 10 protein heterogeneity which may have implications for diagnosis and immunotherapy of HBV allergy. In the present study, RT-PCR revealed the expression of at least nine additional Api m 10 transcript isoforms by the venom glands. Two distinct mechanisms are responsible for the generation of these isoforms: while the previously known variant 2 is produced by an alternative splicing event, novel identified isoforms are intragenic chimeric transcripts. To the best of our knowledge, this is the first report of the identification of chimeric transcripts generated by the honeybee. By a retrospective proteomic analysis we found evidence for the presence of several of these isoforms in the venom proteome. Additionally, we analyzed IgE reactivity to different isoforms by protein array technology using sera from HBV allergic patients, which revealed that IgE recognition of Api m 10 is both isoform- and patient-specific. While it was previously demonstrated that the majority of HBV allergic patients display IgE reactivity to variant 2, our study also shows that some patients lacking IgE antibodies for variant 2 display IgE reactivity to two of the novel identified Api m 10 variants, i.e. variants 3 and 4. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monoclonal antibodies to meningococcal factor H binding protein with overlapping epitopes and discordant functional activity.

Science.gov (United States)

Giuntini, Serena; Beernink, Peter T; Reason, Donald C; Granoff, Dan M

2012-01-01

Meningococcal factor H binding protein (fHbp) is a promising vaccine candidate. Anti-fHbp antibodies can bind to meningococci and elicit complement-mediated bactericidal activity directly. The antibodies also can block binding of the human complement down-regulator, factor H (fH). Without bound fH, the organism would be expected to have increased susceptibility to bacteriolysis. Here we describe bactericidal activity of two anti-fHbp mAbs with overlapping epitopes in relation to their different effects on fH binding and bactericidal activity. Both mAbs recognized prevalent fHbp sequence variants in variant group 1. Using yeast display and site-specific mutagenesis, binding of one of the mAbs (JAR 1, IgG3) to fHbp was eliminated by a single amino acid substitution, R204A, and was decreased by K143A but not by R204H or D142A. The JAR 1 epitope overlapped that of previously described mAb (mAb502, IgG2a) whose binding to fHbp was eliminated by R204A or R204H substitutions, and was decreased by D142A but not by K143A. Although JAR 1 and mAb502 appeared to have overlapping epitopes, only JAR 1 inhibited binding of fH to fHbp and had human complement-mediated bactericidal activity. mAb502 enhanced fH binding and lacked human complement-mediated bactericidal activity. To control for confounding effects of different mouse IgG subclasses on complement activation, we created chimeric mAbs in which the mouse mAb502 or JAR 1 paratopes were paired with human IgG1 constant regions. While both chimeric mAbs showed similar binding to fHbp, only JAR 1, which inhibited fH binding, had human complement-mediated bactericidal activity. The lack of human complement-mediated bactericidal activity by anti-fHbp mAb502 appeared to result from an inability to inhibit binding of fH. These results underscore the importance of inhibition of fH binding for anti-fHbp mAb bactericidal activity.

Hyposensitization therapy with whole pollen extract or purified allergens monitored by immunoblotting

DEFF Research Database (Denmark)

Jarolim, E; Matthiesen, F; Skov, P S

1990-01-01

. Inhibition experiments using allergenic components isolated by preparative sodium dodecyl sulphate-polyacrylamide gel electrophoresis indicated that all antigenic components of timothy grass pollen detected in immunoblot dispose of private and cross-reactive determinants for binding of human IgE. The worse......Patients allergic to grass pollen were hyposensitized with two major allergenic components or whole extract of timothy grass pollen. Specific IgE, IgG1, and IgG4 formed during immunotherapy were analyzed by immunoblotting. Similar antibody-binding patterns were observed in both patient groups...

Mycoplasma infection of cell lines can simulate the expression of Fc receptors by binding of the carbohydrate moiety of antibodies.

Science.gov (United States)

Lemke, H; Krausse, R; Lorenzen, J; Havsteen, B

1985-05-01

During the production of Fc receptor (FcR)-bearing hybridomas it was observed with a particular monoclonal anti-sheep red blood cell antibody (anti-SRBC 1/5, IgG1) that the contamination with Mycoplasma arginini of in vitro cultured cell lines leads to an apparent FcR activity. This property did not correspond with the serological typing since other antibodies of the same isotype could not support FcR rosette formation. Another mycoplasma strain M. orale lacked this property. Analysis of the binding reaction revealed that M. arginini contains a lectin which binds the carbohydrate moiety of the anti-SRBC 1/5 antibody, i.e. anti-SRBC 1/5 synthesized under the influence of tunicamycin or deglycosylated by NaIO4 oxidation did not support rosette formation. These data suggest that binding of antibodies to certain mycoplasma strains may be a pathogenic factor during mycoplasma infections by masking the microorganisms with the host's own defense molecules. The experiments with M. arginini-infected cell lines gain immunological importance since we obtained identical results with staphylococcal protein A, as another bacteriological FcR, and cell lines expressing intrinsic membrane FcR. Although it is an open question whether the glycoconjugates are directly bound by the FcR or else by influencing the three-dimensional structure of the antibodies, it seems possible that FcR in general may be lectins.

IgE, IgG4 and IgA specific to Bet v 1-related food allergens do not predict oral allergy syndrome.

Science.gov (United States)

Guhsl, E E; Hofstetter, G; Lengger, N; Hemmer, W; Ebner, C; Fröschl, R; Bublin, M; Lupinek, C; Breiteneder, H; Radauer, C

2015-01-01

Birch pollen-associated plant food allergy is caused by Bet v 1-specific IgE, but presence of cross-reactive IgE to related allergens does not predict food allergy. The role of other immunoglobulin isotypes in the birch pollen-plant food syndrome has not been investigated in detail. Bet v 1-sensitized birch pollen-allergic patients (n = 35) were diagnosed for food allergy by standardized interviews, skin prick tests, prick-to-prick tests and ImmunoCAP. Concentrations of allergen-specific IgE, IgG1, IgG4 and IgA to seven Bet v 1-related food allergens were determined by ELISA. Bet v 1, Cor a 1, Mal d 1 and Pru p 1 bound IgE from all and IgG4 and IgA from the majority of sera. Immunoglobulins to Gly m 4, Vig r 1 and Api g 1.01 were detected in allergy and increased or reduced levels of IgE, IgG1, IgG4 or IgA specific to most Bet v 1-related allergens. Api g 1-specific IgE was significantly (P = 0.01) elevated in celeriac-allergic compared with celeriac-tolerant patients. Likewise, frequencies of IgE (71% vs 15%; P = 0.01) and IgA (86% vs 38%; P = 0.04) binding to Api g 1.01 were increased. Measurements of allergen-specific immunoglobulins are not suitable for diagnosing Bet v 1-mediated plant food allergy to hazelnut and Rosaceae fruits. In contrast, IgE and IgA to the distantly related allergen Api g 1 correlate with allergy to celeriac. © 2014 The Authors. Allergy Published by John Wiley & Sons Ltd.

Designing two-in-one antibodies.

Science.gov (United States)

Valladares, Ignacio Garcia; Espinoza, Luis R

2009-09-01

Evaluation of: Bostrom J, Shang-Fan Y, Kan D et al.: Variants of the antibody Herceptin that interact with HER2 and VEGF at the antigen binding site. Science 323, 1610-1614 (2009). The longstanding held notion that one antibody equals one antigen and, hence, one function has been challenged in recent years. Improved technology in antibody production, especially the accumulation of sequence data of immunoglobulin genes and the advent of PCR have made it possible to clone antibody gene repertoires. The current paper provides further challenge to the notion of one antibody = one antigen by developing 'two-in-one' antibodies with an antigen-binding site that binds two distinct proteins with high affinity. A therapeutic variant antibody of Herceptin (Genentech, CA, USA) was isolated that binds the human EGF receptor (HER)2 and also to VEGF. This development may represent a breakthrough discovery and may have significant implications in the therapy of malignant, infectious, allergic and autoimmune disorders.

The binding affinity of a soluble TCR-Fc fusion protein is significantly improved by crosslinkage with an anti-C{beta} antibody

Energy Technology Data Exchange (ETDEWEB)

Ozawa, Tatsuhiko; Horii, Masae; Kobayashi, Eiji [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Jin, Aishun [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Department of Immunology, College of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin 150081 (China); Kishi, Hiroyuki, E-mail: immkishi@med.u-toyama.ac.jp [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Muraguchi, Atsushi [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan)

2012-06-01

Highlights: Black-Right-Pointing-Pointer A novel soluble TCR composed of TCR V and C regions with Ig Fc region is generated. Black-Right-Pointing-Pointer TCR-Fc protein immobilized by an anti-C{beta} antibody bound to a p/MHC tetramer. Black-Right-Pointing-Pointer Binding affinity of TCR-Fc was markedly increased by binding with anti-C{beta} antibody. -- Abstract: The identification and cloning of tumor antigen-specific T cell receptors (TCRs) and the production of the soluble form of the TCR (sTCR) contributed to the development of diagnostic and therapeutic tools for cancer. Recently, several groups have reported the development of technologies for the production of sTCRs. The native sTCR has a very low binding affinity for the antigenic peptide/MHC (p/MHC) complex. In this study, we established a technology to produce high affinity, functional sTCRs. We generated a novel sTCR-Fc fusion protein composed of the TCR V and C regions of the TCR linked to the immunoglobulin (Ig) Fc region. A Western blot analysis revealed that the molecular weight of the fusion protein was approximately 60 kDa under reducing conditions and approximately 100-200 kDa under non-reducing conditions. ELISAs using various antibodies showed that the structure of each domain of the TCR-Fc protein was intact. The TCR-Fc protein immobilized by an anti-C{beta} antibody effectively bound to a p/MHC tetramer. An SPR analysis showed that the TCR-Fc protein had a low binding affinity (KD; 1.1 Multiplication-Sign 10{sup -5} M) to the p/MHC monomer. Interestingly, when the TCR-Fc protein was pre-incubated with an anti-C{beta} antibody, its binding affinity for p/MHC increased by 5-fold (2.2 Multiplication-Sign 10{sup -6} M). We demonstrated a novel method for constructing a functional soluble TCR using the Ig Fc region and showed that the binding affinity of the functional sTCR-Fc was markedly increased by an anti-C{beta} antibody, which is probably due to the stabilization of the V

Identification of epitopes within integrin β4 for binding of auto-antibodies in ocular cicatricial and mucous membrane pemphigoid: preliminary report.

Science.gov (United States)

Rashid, Khwaja Aftab; Foster, C Stephen; Ahmed, A Razzaque

2013-11-19

To identify the epitopes on human β4 integrin to which the sera of patients with ocular cicatricial pemphigoid (OCP) and mucous membrane pemphigoid (MMP) without ocular involvement bind. Fragments of the intracellular domain of the β4 molecule were cloned, expressed, purified and peptides were synthesized. Antibodies to various fragments and peptides were produced in rabbits. Binding specificity was determined via Western blot and blocking experiments. Test sera and controls were injected into neonatal BALB/c mice for in vivo passive transfer. Sera from patients with OCP, MMP, and both OCP and MMP were bound to cloned fragments of IC3.0. Its subcloned fragments IC3.4 (1489 aa-1572 aa) and IC3.4.1 (1489 aa-1510 aa) were bound with the sera from patients with OCP only. Subcloned fragments IC3.6 (1573 aa-1822 aa) and IC3.6.1 (1689 aa-1702 aa) were bound with MMP sera only. No cross-reactivity in binding was observed. Immuno-affinity-purified sera from patients with OCP, MMP, and rabbit antibodies to IC3.0, IC3.4, IC3.4.1, IC3.6, and IC3.6.1, when injected in neonatal BALB/c mice, produced subepidermal blisters in their skin. These preliminary observations identified IC3.4.1 as the possible epitope for the binding of OCP auto-antibody and IC3.6.1 as the possible epitope for the binding of MMP auto-antibody without ocular disease. Antibodies specific to these peptides produced blisters when injected in mice. Still-unidentified epitopes may exist. These observations may enhance our understanding of the role of β4 integrin in the pathobiology of OCP and MMP. Early diagnosis may be possible if serologic tests with specificity and sensitivity can be developed.

Structure-based engineering to restore high affinity binding of an isoform-selective anti-TGFβ1 antibody

Science.gov (United States)

Honey, Denise M.; Best, Annie; Qiu, Huawei

2018-01-01

ABSTRACT Metelimumab (CAT192) is a human IgG4 monoclonal antibody developed as a TGFβ1-specific antagonist. It was tested in clinical trials for the treatment of scleroderma but later terminated due to lack of efficacy. Subsequent characterization of CAT192 indicated that its TGFβ1 binding affinity was reduced by ∼50-fold upon conversion from the parental single-chain variable fragment (scFv) to IgG4. We hypothesized this result was due to decreased conformational flexibility of the IgG that could be altered via engineering. Therefore, we designed insertion mutants in the elbow region and screened for binding and potency. Our results indicated that increasing the elbow region linker length in each chain successfully restored the isoform-specific and high affinity binding of CAT192 to TGFβ1. The crystal structure of the high binding affinity mutant displays large conformational rearrangements of the variable domains compared to the wild-type antigen-binding fragment (Fab) and the low binding affinity mutants. Insertion of two glycines in both the heavy and light chain elbow regions provided sufficient flexibility for the variable domains to extend further apart than the wild-type Fab, and allow the CDR3s to make additional interactions not seen in the wild-type Fab structure. These interactions coupled with the dramatic conformational changes provide a possible explanation of how the scFv and elbow-engineered Fabs bind TGFβ1 with high affinity. This study demonstrates the benefits of re-examining both structure and function when converting scFv to IgG molecules, and highlights the potential of structure-based engineering to produce fully functional antibodies. PMID:29333938

Quantum dots-based lateral flow immunoassay combined with image analysis for semiquantitative detection of IgE antibody to mite

Directory of Open Access Journals (Sweden)

Zhao Y

2017-07-01

Full Text Available Yan Zhao,1,* Qiang Zhang,2,* Qingfeng Meng,3 Fenglian Wu,4 Lihua Zhang,1 Yao Tang,1 Yuanyuan Guan,1 Lixin An1 1Department of Allergy, The First Affiliated Hospital, Harbin Medical University, Harbin, 2Department of Otorhinolaryngology Head and Neck Surgery, The Affiliated Yantai Yuhuangding Hospital, Qingdao University, Yantai, 3Department of Ophthalmology, The First Affiliated Hospital, Harbin Medical University, Harbin, 4Department of Burn and Plastic Surgery, The First Affiliated Hospital of Qinhuangdao, Qinhuangdao, People’s Republic of China *These authors contributed equally to this work Abstract: Semiquantitative and rapid detection of specific IgE (sIgE with well clinical relevance to house dust mite (HDM are promising for prevalence rhinitis and asthma patients due to the increasing air pollution. However, the conventional IgE measurement systems are time-consuming, complicated and require special instruments. Herein, we overcome the above limitations of sIgE to HDM detection system by developing a quantum dot nanobeads-based lateral flow immunoassay and an image analysis procedure. The proposed detection system could semiquantitatively measure the IgE in a linear range of 0.2–10 U/mL. Moreover, there is a well correlation between the developed detection system and the clinical symptoms by a comparison study using 56 positive patients’ sera and 40 healthy control sera. The proposed detection system is simple, robust and easy-to-use and promising for in home test. Keywords: lateral flow immunoassay, quantum dots, house dust mite, IgE 

Effects of industrial processing on the immunogenicity of commonly ingested fish species.

Science.gov (United States)

Sletten, Gaynour; Van Do, Thien; Lindvik, Helene; Egaas, Eliann; Florvaag, Erik

2010-01-01

Food-processing techniques may induce changes in fish protein immunogenicity. Allergens from >100 fish species have been identified, but little is known on the effects of processing on fish protein immunogenicity. IgE binding of sera of patients allergic to fresh and processed (smoked, salted/sugar-cured, canned, lye-treated and fermented) cod, haddock, salmon, trout, tuna, mackerel and herring and of hydrolysates based on salmon and whiting was investigated using immunoblot and inhibition ELISA. Parvalbumin oligomers were identified using monoclonal and polyclonal antibodies. IgE binding was seen in most sera at 12-14 kDa (parvalbumin), and at 17-60 kDa for all fish except tuna. Changes in IgE binding appeared to reflect altered parvalbumin monomers and oligomers. Smoked haddock, salmon and mackerel had increased IgE binding and novel bands at 30 kDa. Chemically processed cod, salmon, trout and pickled herring had reduced or abolished IgE binding. The serum of 1 subject, however, had increased IgE binding to these products and also inhibition of binding by both fish hydrolysates to their constituent fish species. Process-induced changes in fish protein immunogenicity were more dependent on process rather than species, although individual responses varied. Changes in the allergenicity of a product may depend on the net effect of processing on parvalbumin oligomerization patterns, which may also vary in different species. Chemical processes generally caused loss in IgE-binding activity, though sensitization may occur to modified or degraded rather than intact peptides as shown by increased binding by chemically processed fish and hydrolysates in 1 subject. The clinical significance of these findings remains to be established.

Repeated vaccination with tetanus toxoid of plasma donors with pre-existing specific IgE transiently elevates tetanus-specific IgE but does not induce allergic symptoms

NARCIS (Netherlands)

Unger, Peter-Paul A.; Makuch, Mateusz; Aalbers, Marja; Derksen, Ninotska I. L.; ten Brinke, Anja; Aalberse, Rob C.; Rispens, Theo; van Ham, S. Marieke

2018-01-01

IgE responses against allergens have acquired much attention due to their pathogenic nature as mediators of allergic reactions. In contrast, IgE responses against vaccines like Diphtheria-Tetanus-Pertussis (DTP) and the potential persistence of IgE production have received relatively little

Characteristics Studies of 125I- and total PSA antibody's Binding with prostate specific antigen (PSA) in Human Uterus Tumors

International Nuclear Information System (INIS)

Al-Mudaffar, S.; Al-Salihi, J.

2005-01-01

Two groups of uterus tumors (benign and malignant) postmenopausal patients were used to investigate the presence of prostate specific antigen (PSA). Preliminary experiments were performed to follow the binding of '1 25 I-anti total PSA antibody with PSA in uterus tissues homogenates of the two groups with their corresponding antigen and found to be (8.8,7.1%) for benign and malignant tumors, respectively. An Immuno Radio Metric Assay (IRMA) procedure was developed for measuring PSA in benign and malignant uterus tumors homogenates. The optimum conditions of the binding of 125 I-anti total PSA antibody with PSA were as follows: PSA concentration (150,200 μg protein),tracer antibody concentration (125,250 μg protein), p H (7.6,7.2), temp (15,25?C) and time (1.5 hrs) for postmenopausal benign and malignant uterus tumors tissue homogenates, respectively. The use of different concentrations of Na + and Mg 2+ ions were shown to cause an increase in the binding at concentration of (125,75 mΜ) of Na 1+ ions (75,225 mΜ) of Mg 2+ ions for benign and malignant uterus tumors homogenates, respectively, while the use of different concentrations of urea and polyethylene glycol (PEG) Caused a decrease in the binding with the increase in the concentration of each of urea and PEG in the both cases

Hierarchy and molecular properties of house dust mite allergens

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Wayne R. Thomas

2015-10-01

Full Text Available The allergenic load of house dust mite allergy is largely constituted by a few proteins with a hierarchical pattern of allergenicity. The serodominant specificities are the group 1&2 and the group 23 faecal allergens. The collective IgE binding to the group 1&2 allergens can measure unequivocal HDM sensitisation better than HDM extracts although discrepancies have been found in regions with complex acarofauna suggesting a need to investigate the specificity with allergen components. The group 4, 5, 7&21 allergens that each induce responses in about 40% of subjects are mid-tier allergens accounting for most of the remaining IgE binding. Their titres are proportional to the concomitant responses to Der p1&2. Group 2 allergen variants have different antibody binding. Body proteins only occasionally induce sensitisation although a higher prevalence of binding by atopic dermatitis patients provides a new avenue of research. A broad spectrum of IgE binding has been associated with diverse symptoms but not with the severity of asthma which is associated with low IgG antibody. Some allergens such as the group 14 large lipid binding proteins and the recently described proteins Der f 24–33, need further investigation but with the cognoscence that other denominated allergens have been found to be minor sensitisers by comparative quantitative analyses. Scabies is a confounder for diagnosis with extracts, inducing cross-reactive antibodies with Der p 4&20 as is seafood allergy with cross reactivity to Der p 10 a minor HDM allergen. The HDM genome sequence can now be used to verify allelic and paralogous variations.

Mechanism of Binding to Ebola Virus Glycoprotein by the ZMapp, ZMAb, and MB-003 Cocktail Antibodies

OpenAIRE

Davidson, Edgar; Bryan, Christopher; Fong, Rachel H.; Barnes, Trevor; Pfaff, Jennifer M.; Mabila, Manu; Rucker, Joseph B.; Doranz, Benjamin J.

2015-01-01

Cocktails of monoclonal antibodies (MAbs) that target the surface glycoprotein (GP) of Ebola virus (EBOV) are effective in nonhuman primate models and have been used under emergency compassionate-treatment protocols in human patients. However, the amino acids that form the detailed binding epitopes for the MAbs in the ZMapp, ZMAb, and the related MB-003 cocktails have yet to be identified. Other binding properties that define how each MAb functionally interacts with GP—such as affinity, epito...

Generation and epitope analysis of human monoclonal antibody isotypes with specificity for the timothy grass major allergen Phl p 5a

DEFF Research Database (Denmark)

Hecker, J.; Diethers, A.; Seismann, H.

2011-01-01

The scarcity of monoclonal human IgE antibodies with specificity for defined allergens is a bottleneck for the molecular characterisation of allergens and their epitopes. Insights into the characteristics of such antibodies may allow for analyses of the molecular basis underlying allergenicity an...

Identification of a CD4-Binding-Site Antibody to HIV that Evolved Near-Pan Neutralization Breadth

Energy Technology Data Exchange (ETDEWEB)

Huang, Jinghe; Kang, Byong H.; Ishida, Elise; Zhou, Tongqing; Griesman, Trevor; Sheng, Zizhang; Wu, Fan; Doria-Rose, Nicole A.; Zhang, Baoshan; McKee, Krisha; O’Dell, Sijy; Chuang, Gwo-Yu; Druz, Aliaksandr; Georgiev, Ivelin S.; Schramm, Chaim A.; Zheng, Anqi; Joyce, M.  Gordon; Asokan, Mangaiarkarasi; Ransier, Amy; Darko, Sam; Migueles, Stephen A.; Bailer, Robert T.; Louder, Mark K.; Alam, S.  Munir; Parks, Robert; Kelsoe, Garnett; Von Holle, Tarra; Haynes, Barton F.; Douek, Daniel C.; Hirsch, Vanessa; Seaman, Michael S.; Shapiro, Lawrence; Mascola, John R.; Kwong, Peter D.; Connors, Mark

2016-11-01

Detailed studies of the broadly neutralizing antibodies (bNAbs) that underlie the best available examples of the humoral immune response to HIV are providing important information for the development of therapies and prophylaxis for HIV-1 infection. Here, we report a CD4-binding site (CD4bs) antibody, named N6, that potently neutralized 98% of HIV-1 isolates, including 16 of 20 that were resistant to other members of its class. N6 evolved a mode of recognition such that its binding was not impacted by the loss of individual contacts across the immunoglobulin heavy chain. In addition, structural analysis revealed that the orientation of N6 permitted it to avoid steric clashes with glycans, which is a common mechanism of resistance. Thus, an HIV-1-specific bNAb can achieve potent, near-pan neutralization of HIV-1, making it an attractive candidate for use in therapy and prophylaxis.

Total and antigen-specific Ige levels in umbilical cord blood

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Sybilski AJ

2009-12-01

Full Text Available Abstract The present study was conducted to learn whether the perinatal and environmental factors could influence the total and antigen-specific IgE levels in umbilical cord blood. Retrospective data were obtained from 173 mother-infant pairs. Total and specific (for children's food, wheat/grass and house dust mite-HDM cord blood IgE levels were determined using the immunoassay test. The total cord blood IgE was between 0.0-23.08 IU/ml (mean 0.55 ± 2.07 IU/ml; median 0.16 IU/ml. Total IgE levels were significantly higher in boys compared with girls (OR = 2.2; P = 0.007, and in newborns with complicated pregnancy (OR = 2.7; P = 0.003. A greater number of siblings correlated with increases in the total cord blood IgE (P

Mapping of the antigenic and allergenic epitopes of Lol p VB using gene fragmentation.

Science.gov (United States)

Ong, E K; Knox, R B; Singh, M B

1995-03-01

The recombinant proteins of Lol p VA and Lol p VB expressed in E. coli reacted with IgE antibodies from sera of allergic patients and mAbs FMC A7 and PpV1. Cross-absorption analyses using these recombinant proteins showed that Lol p VA and Lol p VB possess both similar and unique IgE binding determinants. Gene fragmentation was utilized to localize the antigenic and allergenic determinants of Lol p VB. When full-length cDNA of Lol p VB was digested into three fragments and expressed as the fusions from the glutathione transferase of pGEX vectors, fragments Met1-Val196 and Asp197-Val339 bound IgE while fragment Met1-Pro96 did not. The data suggest that there are at least two IgE binding determinants in Lol p VB. In addition, only fragment Met1-Val196 reacted with mAb PpV1. The localization of these determinants was further resolved using random fragment expression libraries. The mAb PpV1 determinant was near the N-terminal region of Lol p VB molecule. The IgE binding determinants were distributed in the central region: region I (amino acids 111-195) and II (199-254). These IgE binding determinants are conserved in Lol p VA.

TRYPTASE OF ORAL LIQUID AND IgE-ANTIBODIES AS A MARKER OF ALLERGIC INFLAMMATION IN THE ORAL MUCOSA

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I. Yu. Karpuk

2018-01-01

Full Text Available The goal of present study was to determine the levels of mast cell tryptase (MCT in whole saliva, and blood serum IgE antibodies in patients with intolerance for dental prosthetic materials (IDM before and after removal of prosthetic constructs. We have conducted examination of the patients suffering from the IDM symptoms, who were divided into 2 groups depending on the time span between the end of prosthetic treatment and emergence of pathological symptoms: group 1 (n = 19, 1 to 14 days (symptoms emerged immediately after treatment; group 2, (n = 18, IDM symptoms occuring 6 months to 5 years later; group 3 (n = 16, controls without complaints for IDM. Whole saliva (WS samples were collected before removal of prosthetic constructs and 1 month later. In group 1, salivary MCT was detected in 16 subjects (84.2% before removal of prosthetic constructs, while 1 month after MCT not detectable in saliva (p < 0.001. Salivary MCT in control group was not detected both before and after removal of prosthetic constructions. Hence, mast cell tryptase in whole saliva could be a diagnostic marker for intolerance to dental materials. In group 1 of the patients, we detected IgE antibodies to Ni-HSA in 78.9% of patients, IgE antibodies to Cr-HSA in 68.4% of patients and IgE to Co-HSA in 52.6% of patients. Salivary MCT levels strongly correlated with IgE levels to Ni-HSA (Rspearman = 0.9; p < 0.05, showing moderate correlation with Cr-HSA (Rspearman = 0.7; p < 0.05. The data obtained suggest some prevalence of immediate type immune reaction against dental materials. Notable local increase of MCT level could be an important diagnostic marker of local inflammatory process initiation. MCT in whole saliva was found only in 3 patients (16.7% from group 2; those had IgE antibodies to metal ions in blood serum, thus indicating IgE-dependent reaction type. Other patients from group 2 were likely to develop a different type of allergic reaction, e. g. delayed or

IgE in lupus pathogenesis: Friends or foes?

Science.gov (United States)

Augusto, Jean-François; Truchetet, Marie-Elise; Charles, Nicolas; Blanco, Patrick; Richez, Christophe

2018-04-01

Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving multiple immunological pathways. Recently, several studies have suggested an implication of Immunoglobulin E (IgE) in the pathophysiology of SLE. In the Lyn -/- and FcγIIB -/- .Yaa lupus mouse models, autoreactive IgE activate basophils, and promote a Th2 environment with, subsequently, production of autoantibodies by plasma cells. Autoreactive IgE has been also shown to play a role in the activation of human plasmacytoid dendritic cells (pDCs), in synergy with IgG, which results in an increase of interferon-alpha (IFN-α) production. In contrast, a protective effect of total non-autoreactive IgE has also been suggested, through a decreased ability of FcεRI-triggered pDCs to secrete IFN-α. This review summarizes in a comprehensive manner the emerging recent literature in the field, and propose new concepts to reconcile the observations. Copyright © 2018 Elsevier B.V. All rights reserved.

Generation of HER2 monoclonal antibodies using epitopes of a rabbit polyclonal antibody.

Science.gov (United States)

Hu, Francis Jingxin; Uhlen, Mathias; Rockberg, Johan

2014-01-25

One of the issues in using polyclonal antibodies is the limited amount of reagent available from an immunisation, leading to batch-to-batch variation and difficulties in obtaining the same antibody performance when the same antigen is re-immunised into several separate animals. This led to the development of hybridoma technology allowing, at least theoretically, for an unlimited production of a specific binder. Nevertheless, polyclonal antibodies are widely used in research and diagnostics and there exists a need for robust methods to convert a polyclonal antibody with good binding performance into a renewable monoclonal with identical or similar binding specificity. Here we have used precise information regarding the functional recognition sequence (epitope) of a rabbit polyclonal antibody with attractive binding characteristics as the basis for generation of a renewable mouse monoclonal antibody. First, the original protein fragment antigen was used for immunisation and generation of mouse hybridoma, without obtaining binders to the same epitope region. Instead a peptide designed using the functional epitope and structural information was synthesised and used for hybridoma production. Several of the monoclonal antibodies generated were found to have similar binding characteristics to those of the original polyclonal antibody. These monoclonal antibodies detected native HER2 on cell lines and were also able to stain HER2 in immunohistochemistry using xenografted mice, as well as human normal and cancer tissues. Copyright © 2013 Elsevier B.V. All rights reserved.

Recombinant pollen allergens from Dactylis glomerata: preliminary evidence that human IgE cross-reactivity between Dac g II and Lol p I/II is increased following grass pollen immunotherapy

NARCIS (Netherlands)

Roberts, A. M.; van Ree, R.; Cardy, S. M.; Bevan, L. J.; Walker, M. R.

1992-01-01

We previously described the isolation of three identical complementary DNA (cDNA) clones, constructed from Orchard/Cocksfoot grass (Dactylis glomerata) anther messenger RNA (mRNA), expressing a 140,000 MW beta-galactosidase fusion protein recognized by IgE antibodies in atopic sera. Partial

Higher Plasma Concentration of Food-Specific Antibodies in Persons with Autistic Disorder in Comparison to Their Siblings

Science.gov (United States)

Trajkovski, Vladimir; Petlichkovski, Aleksandar; Efinska-Mladenovska, Olivija; Trajkov, Dejan; Arsov, Todor; Strezova, Ana; Ajdinski, Ljubomir; Spiroski, Mirko

2008-01-01

Specific IgA, IgG, and IgE antibodies to food antigens in 35 participants with autistic disorder and 21 of their siblings in the Republic of Macedonia were examined. Statistically significant higher plasma concentration of IgA antibodies against alpha-lactalbumin, beta-lactoglobulin, casein, and gliadin were found in the children with autistic…

Cooperative binding of anti-tetanus toxin monoclonal antibodies: Implications for designing an efficient biclonal preparation to prevent tetanus toxin intoxication.

Science.gov (United States)

Lukic, Ivana; Filipovic, Ana; Inic-Kanada, Aleksandra; Marinkovic, Emilija; Miljkovic, Radmila; Stojanovic, Marijana

2018-05-15

Oligoclonal combinations of several monoclonal antibodies (MAbs) are being considered for the treatment of various infectious pathologies. These combinations are less sensitive to antigen structural changes than individual MAbs; at the same time, their characteristics can be more efficiently controlled than those of polyclonal antibodies. The main goal of this study was to evaluate the binding characteristics of six biclonal equimolar preparations (BEP) of tetanus toxin (TeNT)-specific MAbs and to investigate how the MAb combination influences the BEPs' protective capacity. We show that a combination of TeNT-specific MAbs, which not only bind TeNT but also exert positive cooperative effects, results in a BEP with superior binding characteristics and protective capacity, when compared with the individual component MAbs. Furthermore, we show that a MAb with only partial protective capacity but positive effects on the binding of the other BEP component can be used as a valuable constituent of the BEP. Copyright © 2018 Elsevier Ltd. All rights reserved.

Increased IgD milk antibody responses in a patient with Down's syndrome, pulmonary hemosiderosis and cor pulmonale.

Science.gov (United States)

Galant, S; Nussbaum, E; Wittner, R; DeWeck, A L; Heiner, D C

1983-10-01

IgD antibody responses to cow's milk were investigated in a two-year-old black boy with evidence of pulmonary hemosiderosis and pulmonary hypertension. Initially a broad spectrum of immunologic responses to cow's milk were observed including IgD, IgE, and precipitin antibodies. Specific IgD antibody responses to cow's milk could be modulated in terms of challenge or elimination and correlated with the clinical course. It is possible that IgD antibodies may be important in milk-related pulmonary hemosiderosis.

Serum IgE and IgG4 against muscle larva excretory-secretory products during the early and late phases of human trichinellosis.

Science.gov (United States)

Calcagno, Marcela A; Forastiero, María A; Saracino, María P; Vila, Cecilia C; Venturiello, Stella M

2017-11-01

In human trichinellosis, the relevance of the presence and persistence of specific serum IgE and IgG4 during the early and late phases of infection is still controversial.The aim of this work was to determine the percentage of human sera presenting IgE and IgG4 against Trichinella spiralis muscle larvae excretory-secretory products as well as their levels during the early and late phases of the infection. The antigen recognition pattern by serum total immunoglobulins (IgGAM), IgE, and IgG4 was assessed over time. Serum samples during early and late phases were analyzed by ELISA and immunoelectrotransfer blot (IETB).Results showed that (a)-IgE and IgG4 are present at constant levels in both phases; (b)-IgE recognized the glycoproteins of ~ 45 and ~ 55 kDa and IgG4 only the ~ 45 kDa; (c)-in the late phase, the percentage of specific IgE positive sera was higher than that of specific IgG4 by IETB; while in serum samples taken during the early phase, no differences were found between both isotypes; (d)-both isotypes displayed different glycoprotein recognition patterns: the pattern corresponding to IgE was coincident with that of IgGAM, comprising seven glycoproteins (ranging from ~ 116 to ~ 29 kDa), whereas IgG4 revealed four glycoproteins (ranging from ~ 97 to ~ 45 kDa), showing a different sera recognition percentage depending on the phase studied.In conclusion, IgE and IgG4 cannot be considered exclusive isotypes of neither the early nor the late phase of infection and they are as useful as the detection of total antibodies in the early diagnosis.

Allergenic fragments of ryegrass (Lolium perenne) pollen allergen Lol p IV.

Science.gov (United States)

Jaggi, K S; Ekramoddoullah, A K; Kisil, F T

1989-01-01

To facilitate studies on establishing the nature of structure/function relationships of allergens, ryegrass pollen allergen, Lol p IV, was cleaved into smaller fragments by cyanogen bromide (CNBr) and the resulting peptides were further digested with trypsin. The resulting peptides were then fractionated by high performance liquid chromatography (HPLC) on a C-18 reverse phase column. The allergenic activity of the HPLC fractions was evaluated in terms of their ability to inhibit the binding of 125I-Lol p IV to serum IgE antibodies of a grass-allergic patient. Many of these fractions inhibited the binding between the native allergen and IgE antibodies in a dose-dependent manner. The inhibitions were specific, i.e., the fractions did not inhibit the binding between 125I-Lol p I (a group-I ryegrass pollen allergen) and the IgE antibodies present in the allergic human serum. The possibility that the allergenic peptide fractions were contaminated by the native undegraded allergen, which might have accounted for the observed inhibition, was ruled out by the fact that the native allergen could not be detected by SDS-PAGE and the elution profiles of allergenically active peptides did not coincide with that of native allergen. One of the allergenic sites recognized by monoclonal antibody (Mab) 90, i.e., site A, was located in HPLC fractions 90-100 while another allergenic site B (recognized by Mab 12) appeared to be lost following the sequential digestion of Lol p IV with CNBr and trypsin.

Prediction of allergy from family history and cord blood IgE levels. A follow-up at the age of 5 years. Cord blood IgE. IV

DEFF Research Database (Denmark)

Hansen, L G; Halken, S; Høst, A

1993-01-01

was not influenced by cord blood IgE levels or atopic predisposition. Cord blood IgE levels had a low sensitivity as a predictor of atopic disease. A statistically significant correlation between serum levels of IgE at birth and at 5 years was however found (p ... with elevated cord blood IgE levels developed allergic disease before 5 years of age (p 63 kU/l (geometric mean + 1 SD) at the age of 5 years can be regarded as being an elevated level. A cord...... blood IgE level > or = 0.3 kU/l in combination with atopic predisposition was predictive of allergic disease, especially allergic bronchial asthma. With regard to allergic disease, the positive predictive value was 26%, the sensitivity 33% and the rate ratio for development of allergic disease 4...

[IgE myeloma. Laboratory typing difficulties].

Science.gov (United States)

Bovone, Nora S; Fuente, María Cristina; Gastiazoro, Ana María; Alfonso, Graciela; Freitas, María Josefina

2014-01-01

The IgE multiple myeloma is a rare neoplasm of plasma cell accounting for 0.01% of all plasma cell dyscrasias. They are generally of more aggressive development and to date there are no more than 50 cases published in current literature. Laboratory studies are, in these cases, essential for the classification of the monoclonal component in serum and urine. The aim of this presentation is to report a patient diagnosed with IgE myeloma and to point out that the laboratory difficulties noted in these rare cases can lead to an erroneous report.

A Rational Engineering Strategy for Designing Protein A-Binding Camelid Single-Domain Antibodies

Science.gov (United States)

Henry, Kevin A.; Sulea, Traian; van Faassen, Henk; Hussack, Greg; Purisima, Enrico O.; MacKenzie, C. Roger; Arbabi-Ghahroudi, Mehdi

2016-01-01

Staphylococcal protein A (SpA) and streptococcal protein G (SpG) affinity chromatography are the gold standards for purifying monoclonal antibodies (mAbs) in therapeutic applications. However, camelid VHH single-domain Abs (sdAbs or VHHs) are not bound by SpG and only sporadically bound by SpA. Currently, VHHs require affinity tag-based purification, which limits their therapeutic potential and adds considerable complexity and cost to their production. Here we describe a simple and rapid mutagenesis-based approach designed to confer SpA binding upon a priori non-SpA-binding VHHs. We show that SpA binding of VHHs is determined primarily by the same set of residues as in human mAbs, albeit with an unexpected degree of tolerance to substitutions at certain core and non-core positions and some limited dependence on at least one residue outside the SpA interface, and that SpA binding could be successfully introduced into five VHHs against three different targets with no adverse effects on expression yield or antigen binding. Next-generation sequencing of llama, alpaca and dromedary VHH repertoires suggested that species differences in SpA binding may result from frequency variation in specific deleterious polymorphisms, especially Ile57. Thus, the SpA binding phenotype of camelid VHHs can be easily modulated to take advantage of tag-less purification techniques, although the frequency with which this is required may depend on the source species. PMID:27631624

Binding of antibodies to dsDNA by UVB-irradiated spermatozoa in vitro

Energy Technology Data Exchange (ETDEWEB)

Wollina, U; Schaarschmidt, H; Thiel, W; Knopf, B

1986-08-01

Human spermatozoa were exposed to monochromatic UVB light (300 nm) at a dosage range from 1-10/sup 3/ J/m/sup 2/ (xenon-mercury short-arc lamp) and 10/sup -2/-10/sup -1/ J/m/sup 2/ (xenon lamp). UVB irradiation >= 10 J/m/sup 2/ resulted in a subsequent binding of antibodies to double-stranded (ds) DNA. A strong homogeneous head fluorescence was visible. There was no immunoglobulin class restriction. The results were discussed in regards to lupus antigen expression by UV light.

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.

IgE epitopes of intact and digested Ara h 1

DEFF Research Database (Denmark)

Bøgh, Katrine Lindholm; Nielsen, H.; Madsen, Charlotte Bernhard

2012-01-01

epitopes have been suggested to be of great importance. ObjectiveThe aim of this study was to identify IgE specific epitopes of intact and digested Ara h 1, and to compare epitope patterns between humans and rats. MethodsSera from five peanut allergic patients and five Brown Norway rats were used...... to identify intact and digested Ara h 1-specific IgE epitopes by competitive immunoscreening of a phage-displayed random hepta-mer peptide library using polyclonal IgE from the individual sera. The resulting peptide sequences were mapped on the surface of a three-dimensional structure of the Ara h 1 molecule...... to mimic epitopes using a computer-based algorithm. ResultsPatients as well as rats were shown to have individual IgE epitope patterns. All epitope mimics were conformational and found to cluster into three different areas of the Ara h 1 molecule. Five epitope motifs were identified by patient IgE, which...

T cell responsiveness correlates differentially with antibody isotype levels in clinical and asymptomatic filariasis

NARCIS (Netherlands)

Yazdanbakhsh, M.; Paxton, W. A.; Kruize, Y. C.; Sartono, E.; Kurniawan, A.; van het Wout, A.; Selkirk, M. E.; Partono, F.; Maizels, R. M.

1993-01-01

To establish the relationships among T and B cell responses, active infection, and clinical manifestations in lymphatic filariasis, filarial-specific lymphocyte proliferation, IgG antibody isotypes, and IgE levels were determined in an exposed population: 31 asymptomatic amicrofilaremics, 43

Characterization of cogon grass (Imperata cylindrica) pollen extract and preliminary analysis of grass group 1, 4 and 5 homologues using monoclonal antibodies to Phleum pratense.

Science.gov (United States)

Kumar, L; Sridhara, S; Singh, B P; Gangal, S V

1998-11-01

Previous studies have established the role of Imperata cylindrica (Ic) pollen in type I allergic disorders. However, no systematic information is available on the allergen composition of Ic pollen extract. To characterize the IgE-binding proteins of Ic pollen extract and to detect the presence of grass group 1, 4 and 5 allergen homologues, if any. Pollen extract of Ic was analyzed by in vivo and in vitro procedures such as intradermal tests (ID), enzyme-linked immunosorbent assay (ELISA), ELISA-inhibition, thin-layer isoelectric focusing (TLIEF), sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Dot blot assay was carried out to check the presence of well-known group 1, 4, and 5 allergen homologues in Ic pollen extract. Out of 303 respiratory allergies patients skin-tested, 27 showed sensitivity to Ic pollen extract. Specific IgE levels were elevated in all 15 serum samples tested. The extract prepared for this study was found to be highly potent since it required only 400 ng of homologous proteins for 50% inhibition of binding in ELISA inhibition assays. TLIEF of Ic pollen extract showed 44 silver-stained bands (pI 3.5-7.0) while SDS-PAGE resolved it into 24 Coomassie-Brilliant-Blue-stained bands (MW 100-10 kD). Immunoblotting with individual patient sera recognized 7 major IgE-binding bands (MW 85, 62, 57, 43, 40, 28 and 16 kD) in Ic pollen extract. A panel of monoclonal antibodies, specific to group 1, 4 and 5 allergens from Phleum pratense pollen extract identified group 5 and group 4 homologues in Ic pollen extract. Ic pollen extract was characterized for the protein profile by TLIEF and SDS-PAGE. IgE reactivity was determined by ELISA and immunoblot. Monoclonal antibodies to group 5 and group 4 allergens reacted weakly showing that this pollen contains group 5 and group 4 homologous allergens.

Predictive value of IgE/IgG4 antibody ratio in children with egg allergy

Directory of Open Access Journals (Sweden)

Okamoto Shindou

2012-06-01

Full Text Available Abstract Background The aim of this study was to investigate the role of specific IgG4 antibodies to hen’s egg white and determine their utility as a marker for the outcome of oral challenge test in children sensitized to hen’s egg Methods The hen’s egg oral food challenge test was performed in 105 sensitized children without atopic dermatitis, and the titers of egg white-specific immunoglobulin G4 (IgG4 and immunoglobulin E (IgE antibodies were measured. To set the cut-off values of IgG4, IgE, and the IgE/IgG4 ratio for predicting positive results in oral challenges, receiver operating characteristic curves were plotted and the area under the curves (AUC were calculated. Results Sixty-four of 105 oral challenges with whole eggs were assessed as positive. The AUC for IgE, IgG4, and IgE/IgG4 for the prediction of positive results were 0.609, 0.724, and 0.847, respectively. Thus, the IgE/IgG4 ratio generated significantly higher specificity, sensitivity, positive predictive value (%, and negative predictive value (% than the individual IgE and IgG4. The negative predictive value of the IgE/IgG4 ratio was 90% at a value of 1. Conclusions We have demonstrated that the egg white-specific serum IgE/IgG4 ratio is important for predicting reactivity to egg during food challenges.

Vaccine-Elicited Tier 2 HIV-1 Neutralizing Antibodies Bind to Quaternary Epitopes Involving Glycan-Deficient Patches Proximal to the CD4 Binding Site.

Directory of Open Access Journals (Sweden)

Ema T Crooks

2015-05-01

Full Text Available Eliciting broad tier 2 neutralizing antibodies (nAbs is a major goal of HIV-1 vaccine research. Here we investigated the ability of native, membrane-expressed JR-FL Env trimers to elicit nAbs. Unusually potent nAb titers developed in 2 of 8 rabbits immunized with virus-like particles (VLPs expressing trimers (trimer VLP sera and in 1 of 20 rabbits immunized with DNA expressing native Env trimer, followed by a protein boost (DNA trimer sera. All 3 sera neutralized via quaternary epitopes and exploited natural gaps in the glycan defenses of the second conserved region of JR-FL gp120. Specifically, trimer VLP sera took advantage of the unusual absence of a glycan at residue 197 (present in 98.7% of Envs. Intriguingly, removing the N197 glycan (with no loss of tier 2 phenotype rendered 50% or 16.7% (n = 18 of clade B tier 2 isolates sensitive to the two trimer VLP sera, showing broad neutralization via the surface masked by the N197 glycan. Neutralizing sera targeted epitopes that overlap with the CD4 binding site, consistent with the role of the N197 glycan in a putative "glycan fence" that limits access to this region. A bioinformatics analysis suggested shared features of one of the trimer VLP sera and monoclonal antibody PG9, consistent with its trimer-dependency. The neutralizing DNA trimer serum took advantage of the absence of a glycan at residue 230, also proximal to the CD4 binding site and suggesting an epitope similar to that of monoclonal antibody 8ANC195, albeit lacking tier 2 breadth. Taken together, our data show for the first time that strain-specific holes in the glycan fence can allow the development of tier 2 neutralizing antibodies to native spikes. Moreover, cross-neutralization can occur in the absence of protecting glycan. Overall, our observations provide new insights that may inform the future development of a neutralizing antibody vaccine.

Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

International Nuclear Information System (INIS)

Bates, John T.; Keefer, Christopher J.; Slaughter, James C.; Kulp, Daniel W.; Schief, William R.; Crowe, James E.

2014-01-01

The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K on ) for binding to RSV F protein, while alteration of dissociation rate (K off ) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K on with reduced potency mirrored the effect of increased K on found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K on ) correlated well with the potency of neutralization

Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

Energy Technology Data Exchange (ETDEWEB)

Bates, John T. [The Vanderbilt Vaccine Center, Departments of Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Keefer, Christopher J. [The Vanderbilt Vaccine Center, Departments of Pediatrics, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Slaughter, James C. [The Vanderbilt Vaccine Center, Departments of Biostatistics and Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Kulp, Daniel W. [IAVI Neutralizing Antibody Center and Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA (United States); Schief, William R. [IAVI Neutralizing Antibody Center and Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA (United States); Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA (United States); Crowe, James E., E-mail: james.crowe@vanderbilt.edu [The Vanderbilt Vaccine Center, Departments of Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); The Vanderbilt Vaccine Center, Departments of Pediatrics, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States)

2014-04-15

The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K{sub on}) for binding to RSV F protein, while alteration of dissociation rate (K{sub off}) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K{sub on} with reduced potency mirrored the effect of increased K{sub on} found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K{sub on}) correlated well with the potency of neutralization.

Four-year evaluation of workers exposed to trimellitic anhydride. A brief report

International Nuclear Information System (INIS)

McGrath, K.G.; Roach, D.; Zeiss, C.R.; Patterson, R.

1984-01-01

In a four-year clinical, immunologic, and environmental study of trimellitic anhydride (TMA) exposure in a single plant, 20 workers exposed to TMA powder were evaluated in 1979 and a total of 32 workers were evaluated from 1979 to 1983. Two distinct groups emerged before and after workplace control improvements were made in 1979. Seventeen of the original 20 workers were available for longitudinal study through 1983. Annual clinical evaluations and serum radioimmunoassays for total antibody binding and specific IgE binding to 125I TM-HSA (human serum albumin) were performed on all 32 workers. In 1979, six workers had antibody against TM-HSA, three had the late respiratory systemic syndrome, and two had TMA-induced allergic rhinitis or allergic rhinitis and asthma. One worker had antibody against TM-HSA without illness. Fifteen additional workers were evaluated longitudinally after institution of several workplace control measures. Four of these 15 workers had TMA exposure prior to environmental improvement and joined the study in 1982. The remaining 11 workers joined the study in 1982 and had at least two years of TMA exposure in the modified workplace. None of these 11 workers developed a TMA-induced immunologic syndrome or significant total or specific IgE antibody binding to 125I TM-HSA

The Antibody Response of Pregnant Cameroonian Women to VAR2CSA ID1-ID2a, a Small Recombinant Protein Containing the CSA-Binding Site

Science.gov (United States)

Babakhanyan, Anna; Leke, Rose G. F.; Salanti, Ali; Bobbili, Naveen; Gwanmesia, Philomina; Leke, Robert J. I.; Quakyi, Isabella A.; Chen, John J.; Taylor, Diane Wallace

2014-01-01

In pregnant women, Plasmodium falciparum-infected erythrocytes expressing the VAR2CSA antigen bind to chondroitin sulfate A in the placenta causing placental malaria. The binding site of VAR2CSA is present in the ID1-ID2a region. This study sought to determine if pregnant Cameroonian women naturally acquire antibodies to ID1-ID2a and if antibodies to ID1-ID2a correlate with absence of placental malaria at delivery. Antibody levels to full-length VAR2CSA and ID1-ID2a were measured in plasma samples from 745 pregnant Cameroonian women, 144 Cameroonian men, and 66 US subjects. IgM levels and IgG avidity to ID1-ID2a were also determined. As expected, antibodies to ID1-ID2a were absent in US controls. Although pregnant Cameroonian women developed increasing levels of antibodies to full-length VAR2CSA during pregnancy, no increase in either IgM or IgG to ID1-ID2a was observed. Surprisingly, no differences in antibody levels to ID1-ID2a were detected between Cameroonian men and pregnant women. For example, in rural settings only 8–9% of males had antibodies to full-length VAR2CSA, but 90–96% had antibodies to ID1-ID2a. In addition, no significant difference in the avidity of IgG to ID1-ID2a was found between pregnant women and Cameroonian men, and no correlation between antibody levels at delivery and absence of placental malaria was found. Thus, the response to ID1-ID2a was not pregnancy specific, but predominantly against cross-reactivity epitopes, which may have been induced by other PfEMP1 antigens, malarial antigens, or microbes. Currently, ID1-ID2a is a leading vaccine candidate, since it binds to the CSA with the same affinity as the full-length molecule and elicits binding-inhibitory antibodies in animals. Further studies are needed to determine if the presence of naturally acquired cross-reactive antibodies in women living in malaria endemic countries will alter the response to ID1-ID2a following vaccination with ID1-ID2a. PMID:24505415

The antibody response of pregnant Cameroonian women to VAR2CSA ID1-ID2a, a small recombinant protein containing the CSA-binding site.

Directory of Open Access Journals (Sweden)

Anna Babakhanyan

Full Text Available In pregnant women, Plasmodium falciparum-infected erythrocytes expressing the VAR2CSA antigen bind to chondroitin sulfate A in the placenta causing placental malaria. The binding site of VAR2CSA is present in the ID1-ID2a region. This study sought to determine if pregnant Cameroonian women naturally acquire antibodies to ID1-ID2a and if antibodies to ID1-ID2a correlate with absence of placental malaria at delivery. Antibody levels to full-length VAR2CSA and ID1-ID2a were measured in plasma samples from 745 pregnant Cameroonian women, 144 Cameroonian men, and 66 US subjects. IgM levels and IgG avidity to ID1-ID2a were also determined. As expected, antibodies to ID1-ID2a were absent in US controls. Although pregnant Cameroonian women developed increasing levels of antibodies to full-length VAR2CSA during pregnancy, no increase in either IgM or IgG to ID1-ID2a was observed. Surprisingly, no differences in antibody levels to ID1-ID2a were detected between Cameroonian men and pregnant women. For example, in rural settings only 8-9% of males had antibodies to full-length VAR2CSA, but 90-96% had antibodies to ID1-ID2a. In addition, no significant difference in the avidity of IgG to ID1-ID2a was found between pregnant women and Cameroonian men, and no correlation between antibody levels at delivery and absence of placental malaria was found. Thus, the response to ID1-ID2a was not pregnancy specific, but predominantly against cross-reactivity epitopes, which may have been induced by other PfEMP1 antigens, malarial antigens, or microbes. Currently, ID1-ID2a is a leading vaccine candidate, since it binds to the CSA with the same affinity as the full-length molecule and elicits binding-inhibitory antibodies in animals. Further studies are needed to determine if the presence of naturally acquired cross-reactive antibodies in women living in malaria endemic countries will alter the response to ID1-ID2a following vaccination with ID1-ID2a.

Genotoxic effect and antigen binding characteristics of SLE auto-antibodies to peroxynitrite-modified human DNA.

Science.gov (United States)

Khan, Md Asad; Alam, Khursheed; Mehdi, Syed Hassan; Rizvi, M Moshahid A

2017-12-01

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by auto-antibodies against native deoxyribonucleic acid after modification and is one of the reasons for the development of SLE. Here, we have evaluated the structural perturbations in human placental DNA by peroxynitrite using spectroscopy, thermal denaturation and high-performance liquid chromatography (HPLC). Peroxynitrite is a powerful potent bi-functional oxidative/nitrative agent that is produced both endogenously and exogenously. In experimental animals, the peroxynitrite-modified DNA was found to be highly immunogenic. The induced antibodies showed cross-reactions with different types of DNA and nitrogen bases that were modified with peroxynitrite by inhibition ELISA. The antibody activity was inhibited by approximately 89% with its immunogen as the inhibitor. The antigen-antibodies interaction between induced antibodies with peroxynitrite-modified DNA showed retarded mobility as compared to the native form. Furthermore, significantly increased binding was also observed in SLE autoantibodies with peroxynitrite-modified DNA than native form. Moreover, DNA isolated from lymphocyte of SLE patients revealed significant recognition of anti-peroxynitrite-modified DNA immunoglobulin G (IgG). Our data indicates that DNA modified with peroxynitrite presents unique antigenic determinants that may induce autoantibody response in SLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Laminin binding protein, 34/67 laminin receptor, carries stage-specific embryonic antigen-4 epitope defined by monoclonal antibody Raft.2

International Nuclear Information System (INIS)

Katagiri, Yohko U.; Kiyokawa, Nobutaka; Nakamura, Kyoko; Takenouchi, Hisami; Taguchi, Tomoko; Okita, Hajime; Umezawa, Akihiro; Fujimoto, Junichiro

2005-01-01

We previously produced monoclonal antibodies against the detergent-insoluble microdomain, i.e., the raft microdomain, of the human renal cancer cell line ACHN. Raft.2, one of these monoclonal antibodies, recognizes sialosyl globopentaosylceramide, which has the stage-specific embryonic antigen (SSEA)-4 epitope. Although the mouse embryonal carcinoma (EC) cell line F9 does not express SSEA-4, some F9 cells stained with Raft.2. Western analysis and matrix-assisted laser desorption ionization-time of flight mass spectrometry identified the Raft.2 binding molecule as laminin binding protein (LBP), i.e., 34/67 laminin receptor. Weak acid treatment or digestion with Clostridium perfringens sialidase reduced Raft.2 binding to LBP on nitrocellulose sheets and [ 14 C]galactose was incorporated into LBP, indicating LBP to have a sialylated carbohydrate moiety. Subcellular localization analysis by sucrose density-gradient centrifugation and examination by confocal microscopy revealed LBP to be localized on the outer surface of the plasma membrane. An SSEA-4-positive human EC cell line, NCR-G3 cells, also expressed Raft.2-binding LBP

Stimulation of chymosin secretion by simultaneous expression with chymosin-binding llama single-domain antibody fragments in yeast

NARCIS (Netherlands)

Harmsen, M.M.; Smits, C.B.; Geus, de B.

2002-01-01

We studied the effect of coexpression of chymosin and chymosin-binding llama single-domain antibody fragments (VHHs) on the secretion of chymosin by Saccharomyces cerevisiae cells. A VHH expression library containing chymosin-specific VHHs was obtained by immunization of a llama and coexpressed with

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...

Structure of the omalizumab Fab

Science.gov (United States)

Jensen, Rasmus K.; Plum, Melanie; Tjerrild, Luna; Jakob, Thilo; Spillner, Edzard; Andersen, Gregers Rom

2015-01-01

Omalizumab is a humanized anti-IgE antibody that inhibits the binding of IgE to its receptors on mast cells and basophils, thus blocking the IgE-mediated release of inflammatory mediators from these cells. Omalizumab binds to the Fc domains of IgE in proximity to the binding site of the high-affinity IgE receptor Fc∊RI, but the epitope and the mechanisms and conformations governing the recognition remain unknown. In order to elucidate the molecular mechanism of its anti-IgE activity, the aim was to analyse the interaction of omalizumab with human IgE. Therefore, IgE Fc C∊2–4 was recombinantly produced in mammalian HEK-293 cells. Functionality of the IgE Fc was proven by ELISA and mediator-release assays. Omalizumab IgG was cleaved with papain and the resulting Fab was purified by ion-exchange chromatography. The complex of IgE Fc with omalizumab was prepared by size-exclusion chromatography. However, crystals containing the complex were not obtained, suggesting that the process of crystallization favoured the dissociation of the two proteins. Instead, two structures of the omalizumab Fab with maximum resolutions of 1.9 and 3.0 Å were obtained. The structures reveal the arrangement of the CDRs and the position of omalizumab residues known from prior functional studies to be involved in IgE binding. Thus, the structure of omalizumab provides the structural basis for understanding the function of omalizumab, allows optimization of the procedure for complex crystallization and poses questions about the conformational requirements for anti-IgE activity. PMID:25849503

Digestibility and IgE-Binding of Glycosylated Codfish Parvalbumin

Science.gov (United States)

de Jongh, Harmen H. J.; Robles, Carlos López; Nordlee, Julie A.; Lee, Poi-Wah; Baumert, Joseph L.; Hamilton, Robert G.; Taylor, Steve L.; Koppelman, Stef J.

2013-01-01

Food-processing conditions may alter the allergenicity of food proteins by different means. In this study, the effect of the glycosylation as a result of thermal treatment on the digestibility and IgE-binding of codfish parvalbumin is investigated. Native and glycosylated parvalbumins were digested with pepsin at various conditions relevant for the gastrointestinal tract. Intact proteins and peptides were analysed for apparent molecular weight and IgE-binding. Glycosylation did not substantially affect the digestion. Although the peptides resulting from digestion were relatively large (3 and 4 kDa), the IgE-binding was strongly diminished. However, the glycosylated parvalbumin had a strong propensity to form dimers and tetramers, and these multimers bound IgE intensely, suggesting stronger IgE-binding than monomeric parvalbumin. We conclude that glycosylation of codfish parvalbumin does not affect the digestibility of parvalbumin and that the peptides resulting from this digestion show low IgE-binding, regardless of glycosylation. Glycosylation of parvalbumin leads to the formation of higher order structures that are more potent IgE binders than native, monomeric parvalbumin. Therefore, food-processing conditions applied to fish allergen can potentially lead to increased allergenicity, even while the protein's digestibility is not affected by such processing. PMID:23878817

Digestibility and IgE-Binding of Glycosylated Codfish Parvalbumin

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Harmen H. J. de Jongh

2013-01-01

Full Text Available Food-processing conditions may alter the allergenicity of food proteins by different means. In this study, the effect of the glycosylation as a result of thermal treatment on the digestibility and IgE-binding of codfish parvalbumin is investigated. Native and glycosylated parvalbumins were digested with pepsin at various conditions relevant for the gastrointestinal tract. Intact proteins and peptides were analysed for apparent molecular weight and IgE-binding. Glycosylation did not substantially affect the digestion. Although the peptides resulting from digestion were relatively large (3 and 4 kDa, the IgE-binding was strongly diminished. However, the glycosylated parvalbumin had a strong propensity to form dimers and tetramers, and these multimers bound IgE intensely, suggesting stronger IgE-binding than monomeric parvalbumin. We conclude that glycosylation of codfish parvalbumin does not affect the digestibility of parvalbumin and that the peptides resulting from this digestion show low IgE-binding, regardless of glycosylation. Glycosylation of parvalbumin leads to the formation of higher order structures that are more potent IgE binders than native, monomeric parvalbumin. Therefore, food-processing conditions applied to fish allergen can potentially lead to increased allergenicity, even while the protein’s digestibility is not affected by such processing.

Structural basis for the binding of the neutralizing antibody, 7D11, to the poxvirus L1 protein

International Nuclear Information System (INIS)

Su, Hua-Poo; Golden, Joseph W.; Gittis, Apostolos G.; Hooper, Jay W.; Garboczi, David N.

2007-01-01

Medical countermeasures to prevent or treat smallpox are needed due to the potential use of poxviruses as biological weapons. Safety concerns with the currently available smallpox vaccine indicate a need for research on alternative poxvirus vaccine strategies. Molecular vaccines involving the use of proteins and/or genes and recombinant antibodies are among the strategies under current investigation. The poxvirus L1 protein, encoded by the L1R open reading frame, is the target of neutralizing antibodies and has been successfully used as a component of both protein subunit and DNA vaccines. L1-specific monoclonal antibodies (e.g., mouse monoclonal antibody mAb-7D11, mAb-10F5) with potent neutralizing activity bind L1 in a conformation-specific manner. This suggests that proper folding of the L1 protein used in molecular vaccines will affect the production of neutralizing antibodies and protection. Here, we co-crystallized the Fab fragment of mAb-7D11 with the L1 protein. The crystal structure of the complex between Fab-7D11 and L1 reveals the basis for the conformation-specific binding as recognition of a discontinuous epitope containing two loops that are held together by a disulfide bond. The structure of this important conformational epitope of L1 will contribute to the development of molecular poxvirus vaccines and also provides a novel target for anti-poxvirus drugs. In addition, the sequence and structure of Fab-7D11 will contribute to the development of L1-targeted immunotherapeutics

Novel IgE Inhibitors for the Treatment of Food Allergies

Science.gov (United States)

2016-10-01

our chances of identifying inhibitors of the IgE:FcR Figure 4. Yeast surface display and selection of mutated anti-IgE scFv clone 18 from an error...complex was used to generate a point mutation in the IgE-Fc, yielding an omalizumab-resistant IgE. Omalizumab-resistant IgE, in combination with...display experiments with wt and mutant IgE-Fc Month 10 Obtained yeast display library, generated selection reagents (IgE), completed anti-IgE

Structural analysis of the endogenous glycoallergen Hev b 2 (endo-β-1,3-glucanase) from Hevea brasiliensis and its recognition by human basophils

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Rodríguez-Romero, Adela, E-mail: adela@unam.mx; Hernández-Santoyo, Alejandra; Fuentes-Silva, Deyanira [Universidad Nacional Autónoma de México, Circuito Exterior, CU, 04310 Coyoacán, DF (Mexico); Palomares, Laura A. [Universidad Nacional Autónoma de México, Apartado Postal 510-3, 62250 Cuernavaca, MOR (Mexico); Muñoz-Cruz, Samira; Yépez-Mulia, Lilian [Centro Médico Nacional Siglo XXI, IMSS, Avenida Cuauhtémoc 330, Colonia Doctores, Mexico, DF (Mexico); Orozco-Martínez, Socorro [Instituto Nacional de Pediatría, Insurgentes Sur 3700C, 04530 Cuicuilco, DF (Mexico); Universidad Nacional Autónoma de México, Circuito Exterior, CU, 04310 Coyoacán, DF (Mexico)

2014-02-01

This study describes the three-dimensional structure of the endogenous glycosylated allergen Hev b 2 (endo-β-1,3-glucanase), which exhibits three post-translational modifications that form a patch on the surface of the molecule that is proposed to be an allergenic IgE epitope. Endogenous glycosylated Hev b 2 (endo-β-1,3-glucanase) from Hevea brasiliensis is an important latex allergen that is recognized by IgE antibodies from patients who suffer from latex allergy. The carbohydrate moieties of Hev b 2 constitute a potentially important IgE-binding epitope that could be responsible for its cross-reactivity. Here, the structure of the endogenous isoform II of Hev b 2 that exhibits three post-translational modifications, including an N-terminal pyroglutamate and two glycosylation sites at Asn27 and at Asn314, is reported from two crystal polymorphs. These modifications form a patch on the surface of the molecule that is proposed to be one of the binding sites for IgE. A structure is also proposed for the most important N-glycan present in this protein as determined by digestion with specific enzymes. To analyze the role of the carbohydrate moieties in IgE antibody binding and in human basophil activation, the glycoallergen was enzymatically deglycosylated and evaluated. Time-lapse automated video microscopy of basophils stimulated with glycosylated Hev b 2 revealed basophil activation and degranulation. Immunological studies suggested that carbohydrates on Hev b 2 represent an allergenic IgE epitope. In addition, a dimer was found in each asymmetric unit that may reflect a regulatory mechanism of this plant defence protein.

Food related antibodies in headache patients.

OpenAIRE

Merrett, J; Peatfield, R C; Rose, F C; Merrett, T G

1983-01-01

Highly sensitive and specific methods for assaying IgE and IgG4 for antibodies in serum have been developed in order to test a recent suggestion that food allergy is a major cause of migraine. Sera were collected from 208 adults--74 with dietary migraine, 45 with non-dietary migraine, 29 with cluster headache and 60 controls. No significant differences were identified between any of the groups with the one exception that cluster headache patients had significantly raised levels of total serum...

The 1.7 Å X-ray crystal structure of the porcine factor VIII C2 domain and binding analysis to anti-human C2 domain antibodies and phospholipid surfaces.

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Caileen M Brison

Full Text Available The factor VIII C2 domain is essential for binding to activated platelet surfaces as well as the cofactor activity of factor VIII in blood coagulation. Inhibitory antibodies against the C2 domain commonly develop following factor VIII replacement therapy for hemophilia A patients, or they may spontaneously arise in cases of acquired hemophilia. Porcine factor VIII is an effective therapeutic for hemophilia patients with inhibitor due to its low cross-reactivity; however, the molecular basis for this behavior is poorly understood. In this study, the X-ray crystal structure of the porcine factor VIII C2 domain was determined, and superposition of the human and porcine C2 domains demonstrates that most surface-exposed differences cluster on the face harboring the "non-classical" antibody epitopes. Furthermore, antibody-binding results illustrate that the "classical" 3E6 antibody can bind both the human and porcine C2 domains, although the inhibitory titer to human factor VIII is 41 Bethesda Units (BU/mg IgG versus 0.8 BU/mg IgG to porcine factor VIII, while the non-classical G99 antibody does not bind to the porcine C2 domain nor inhibit porcine factor VIII activity. Further structural analysis of differences between the electrostatic surface potentials suggest that the C2 domain binds to the negatively charged phospholipid surfaces of activated platelets primarily through the 3E6 epitope region. In contrast, the G99 face, which contains residue 2227, should be distal to the membrane surface. Phospholipid binding assays indicate that both porcine and human factor VIII C2 domains bind with comparable affinities, and the human K2227A and K2227E mutants bind to phospholipid surfaces with similar affinities as well. Lastly, the G99 IgG bound to PS-immobilized factor VIII C2 domain with an apparent dissociation constant of 15.5 nM, whereas 3E6 antibody binding to PS-bound C2 domain was not observed.

Monoclonal Antibodies Against Fusicoccin with Binding Characteristics Similar to the Putative Fusicoccin Receptor of Higher Plants 1

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Feyerabend, Martin; Weiler, Elmar W.

1987-01-01

Monoclonal antibodies were raised against fusicoccin. The toxin, linked to bovine serum albumin through its t-pentenyl moiety, served as immunogen. Hybridomas secreting anti-fusicoccin antibodies were screened by radioimmunoassay employing a novel radioactive derivative, [3H]-nor-fusicoccin-alcohol of high specific activity (1.5 × 1014Bq/mole). The two monoclonal antibodies reported here are of high apparent affinity for fusicoccin (0.71 × 10−9 molar and 1.85 × 10−9 molar). This is comparable to the apparent affinity of rabbit antiserum raised against the same type of conjugate (9.3 × 10−9 molar). A method for the single step purification of the monoclonal antibodies from ascites fluid is reported. A solid-phase immunoassay, using alkaline phosphatase as enzyme, exhibits a measuring range from 0.1 to 1.5 picomoles (about 70 picograms to 1 nanogram) of fusicoccin. The displacement of [3H]-nor-fusicoccin-alcohol from the antibodies by compounds structurally related to fusicoccin exhibits similar selectivity as a microsomal binding assay with the same tracer as radiolabeled probe. Images Fig. 2 PMID:16665786

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

Optimization of the Small Glycan Presentation for Binding a Tumor-Associated Antibody

DEFF Research Database (Denmark)

Kveton, Filip; Blšáková, Anna; Hushegyi, Andras

2017-01-01

on the immobilization of the Tn antigen on a mixed self-assembled monolayer (SAM) (2D biosensor) and the third one utilizing a layer of a human serum albumin (HSA) for the immobilization of a glycan forming a 3D interface. Results showed that the 3D interface with the immobilized Tn antigen is the most effective...... bioreceptive surface for binding its analyte. The 3D impedimetric glycan biosensor exhibited a limit of detection of 1.4 aM, a wide linear range (6 orders of magnitude), and high assay reproducibility with an average relative standard deviation of 4%. The buildup of an interface was optimized using various...... techniques with the visualization of the glycans on the biosensor surface by atomic force microscopy. The study showed that the 3D biosensor is not only the most sensitive compared to other two biosensor platforms but that the Tn antigen on the 3D biosensor surface is more accessible for antibody binding...

Development of β-lactoglobulin-specific chimeric human IgEκ monoclonal antibodies for in vitro safety assessment of whey hydrolysates.

Science.gov (United States)

Knipping, Karen; Simons, Peter J; Buelens-Sleumer, Laura S; Cox, Linda; den Hartog, Marcel; de Jong, Niels; Teshima, Reiko; Garssen, Johan; Boon, Louis; Knippels, Léon M J

2014-01-01

Cow's milk-derived whey hydrolysates are nutritional substitutes for allergic infants. Safety or residual allergenicity assessment of these whey hydrolysates is crucial. Currently, rat basophilic leukemia RBL-2H3 cells expressing the human IgE receptor α-chain (huFcεRIα-RBL-2H3), sensitized with serum IgE from cow's milk allergic children, are being employed to assess in vitro residual allergenicity of these whey hydrolysates. However, limited availability and inter-lot variation of these allergic sera impede standardization of whey hydrolysate safety testing in degranulation assays. An oligoclonal pool of chimeric human (chu)IgE antibodies against bovine β-lactoglobulin (a major allergen in whey) was generated to increase sensitivity, specificity, and reproducibility of existing degranulation assays. Mice were immunized with bovine β-lactoglobulin, and subsequently the variable domains of dissimilar anti-β-lactoglobulin mouse IgG antibodies were cloned and sequenced. Six chimeric antibodies were generated comprising mouse variable domains and human constant IgE/κ domains. After sensitization with this pool of anti-β-lactoglobulin chuIgEs, huFcεRIα-expressing RBL-2H3 cells demonstrated degranulation upon cross-linking with whey, native 18 kDa β-lactoglobulin, and 5-10 kDa whey hydrolysates, whereas a 3 kDa whey hydrolysate and cow's milk powder (mainly casein) showed no degranulation. In parallel, allergic serum IgEs were less sensitive. In addition, our pool anti-β-lactoglobulin chuIgEs recognized multiple allergenic immunodominant regions on β-lactoglobulin, which were also recognized by serum IgEs from cow's milk allergic children. Usage of our 'unlimited' source and well-defined pool of β-lactoglobulin-specific recombinant chuIgEs to sensitize huFcεRIα on RBL-2H3 cells showed to be a relevant and sensitive alternative for serum IgEs from cow's milk allergic patients to assess safety of whey-based non-allergic hydrolyzed formula.

Characterization of Palytoxin Binding to HaCaT Cells Using a Monoclonal Anti-Palytoxin Antibody

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Chiara Florio

2013-02-01

Full Text Available Palytoxin (PLTX is the reference compound for a group of potent marine biotoxins, for which the molecular target is Na+/K+-ATPase. Indeed, ouabain (OUA, a potent blocker of the pump, is used to inhibit some PLTX effects in vitro. However, in an effort to explain incomplete inhibition of PLTX cytotoxicity, some studies suggest the possibility of two different binding sites on Na+/K+-ATPase. Hence, this study was performed to characterize PLTX binding to intact HaCaT keratinocytes and to investigate the ability of OUA to compete for this binding. PLTX binding to HaCaT cells was demonstrated by immunocytochemical analysis after 10 min exposure. An anti-PLTX monoclonal antibody-based ELISA showed that the binding was saturable and reversible, with a Kd of 3 × 10−10 M. However, kinetic experiments revealed that PLTX binding dissociation was incomplete, suggesting an additional, OUA-insensitive, PLTX binding site. Competitive experiments suggested that OUA acts as a negative allosteric modulator against high PLTX concentrations (0.3–1.0 × 10−7 M and possibly as a non-competitive antagonist against low PLTX concentrations (0.1–3.0 × 10−9 M. Antagonism was supported by PLTX cytotoxicity inhibition at OUA concentrations that displaced PLTX binding (1 × 10−5 M. However, this inhibition was incomplete, supporting the existence of both OUA-sensitive and -insensitive PLTX binding sites.

Antibody Binding Selectivity: Alternative Sets of Antigen Residues Entail High-Affinity Recognition.

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Yves Nominé

Full Text Available Understanding the relationship between protein sequence and molecular recognition selectivity remains a major challenge. The antibody fragment scFv1F4 recognizes with sub nM affinity a decapeptide (sequence 6TAMFQDPQER15 derived from the N-terminal end of human papilloma virus E6 oncoprotein. Using this decapeptide as antigen, we had previously shown that only the wild type amino-acid or conservative replacements were allowed at positions 9 to 12 and 15 of the peptide, indicating a strong binding selectivity. Nevertheless phenylalanine (F was equally well tolerated as the wild type glutamine (Q at position 13, while all other amino acids led to weaker scFv binding. The interfaces of complexes involving either Q or F are expected to diverge, due to the different physico-chemistry of these residues. This would imply that high-affinity binding can be achieved through distinct interfacial geometries. In order to investigate this point, we disrupted the scFv-peptide interface by modifying one or several peptide positions. We then analyzed the effect on binding of amino acid changes at the remaining positions, an altered susceptibility being indicative of an altered role in complex formation. The 23 starting variants analyzed contained replacements whose effects on scFv1F4 binding ranged from minor to drastic. A permutation analysis (effect of replacing each peptide position by all other amino acids except cysteine was carried out on the 23 variants using the PEPperCHIP® Platform technology. A comparison of their permutation patterns with that of the wild type peptide indicated that starting replacements at position 11, 12 or 13 modified the tolerance to amino-acid changes at the other two positions. The interdependence between the three positions was confirmed by SPR (Biacore® technology. Our data demonstrate that binding selectivity does not preclude the existence of alternative high-affinity recognition modes.

The effect of treatment on the age-antibody relationship in children infected with Schistosoma mansoni and Schistosoma haematobium

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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.

Tumor necrosis factor-alpha binding capacity and anti-infliximab antibodies measured by fluid-phase radioimmunoassays as predictors of clinical efficacy of infliximab in Crohn's disease

DEFF Research Database (Denmark)

Ainsworth, Mark A; Bendtzen, Klaus; Brynskov, Jørn

2007-01-01

To investigate if the combined assessment of anti-infliximab antibodies (Ab) and the degree of TNF-alpha binding capacity (TNF-alpha-BC) afforded by infliximab may predict the response to infliximab treatment in patients with Crohn's disease (CD).......To investigate if the combined assessment of anti-infliximab antibodies (Ab) and the degree of TNF-alpha binding capacity (TNF-alpha-BC) afforded by infliximab may predict the response to infliximab treatment in patients with Crohn's disease (CD)....

Combining Phage and Yeast Cell Surface Antibody Display to Identify Novel Cell Type-Selective Internalizing Human Monoclonal Antibodies.

Science.gov (United States)

Bidlingmaier, Scott; Su, Yang; Liu, Bin

2015-01-01

Using phage antibody display, large libraries can be generated and screened to identify monoclonal antibodies with affinity for target antigens. However, while library size and diversity is an advantage of the phage display method, there is limited ability to quantitatively enrich for specific binding properties such as affinity. One way of overcoming this limitation is to combine the scale of phage display selections with the flexibility and quantitativeness of FACS-based yeast surface display selections. In this chapter we describe protocols for generating yeast surface antibody display libraries using phage antibody display selection outputs as starting material and FACS-based enrichment of target antigen-binding clones from these libraries. These methods should be widely applicable for the identification of monoclonal antibodies with specific binding properties.

Human monoclonal antibodies: the residual challenge of antibody immunogenicity.

Science.gov (United States)

Waldmann, Herman

2014-01-01

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

Presence of IgE cells in human placenta is independent of malaria infection or chorioamnionitis

DEFF Research Database (Denmark)

Rindsjö, E; Hulthén Varli, I; Ofori, M F

2006-01-01

We have shown previously that numerous IgE(+) macrophage-like cells are present in the villous stroma of full term placenta and that there was no difference in the amount of IgE(+) cells between allergic and non-allergic mothers. The presence of such an abundant number of IgE(+) cells...... from Ghana with and without malaria parasites. The immunohistochemical staining pattern for IgE looked similar to our previous study, with the IgE located on Hofbauer-like cells. We could not find any difference in the amount or distribution of IgE(+) cells between malaria-infected and non...

Antibody engineering using phage display with a coiled-coil heterodimeric Fv antibody fragment.

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Xinwei Wang

Full Text Available A Fab-like antibody binding unit, ccFv, in which a pair of heterodimeric coiled-coil domains was fused to V(H and V(L for Fv stabilization, was constructed for an anti-VEGF antibody. The anti-VEGF ccFv showed the same binding affinity as scFv but significantly improved stability and phage display level. Furthermore, phage display libraries in the ccFv format were constructed for humanization and affinity maturation of the anti-VEGF antibody. A panel of V(H frameworks and V(H-CDR3 variants, with a significant improvement in affinity and expressibility in both E. coli and yeast systems, was isolated from the ccFv phage libraries. These results demonstrate the potential application of the ccFv antibody format in antibody engineering.

Novel Prostate Specific Antigen plastic antibody designed with charged binding sites for an improved protein binding and its application in a biosensor of potentiometric transduction

International Nuclear Information System (INIS)

Rebelo, Tânia S.C.R.; Santos, C.; Costa-Rodrigues, J.; Fernandes, M.H.; Noronha, João P.; Sales, M. Goreti F.

2014-01-01

Graphical abstract: EF13-201, Novel Prostate Specific Antigen plastic antibody designed with charged binding sites for an improved protein binding and its application in a biosensor of potentiometric transduction. - Abstract: This work shows that the synthesis of protein plastic antibodies tailored with selected charged monomers around the binding site enhances protein binding. These charged receptor sites are placed over a neutral polymeric matrix, thus inducing a suitable orientation the protein reception to its site. This is confirmed by preparing control materials with neutral monomers and also with non-imprinted template. This concept has been applied here to Prostate Specific Antigen (PSA), the protein of choice for screening prostate cancer throughout the population, with serum levels >10 ng/mL pointing out a high probability of associated cancer. Protein Imprinted Materials with charged binding sites (C/PIM) have been produced by surface imprinting over graphene layers to which the protein was first covalently attached. Vinylbenzyl(trimethylammonium chloride) and vinyl benzoate were introduced as charged monomers labelling the binding site and were allowed to self-organize around the protein. The subsequent polymerization was made by radical polymerization of vinylbenzene. Neutral PIM (N/PIM) prepared without oriented charges and non imprinted materials (NIM) obtained without template were used as controls. These materials were used to develop simple and inexpensive potentiometric sensor for PSA. They were included as ionophores in plasticized PVC membranes, and tested over electrodes of solid or liquid conductive contacts, made of conductive carbon over a syringe or of inner reference solution over micropipette tips. The electrodes with charged monomers showed a more stable and sensitive response, with an average slope of -44.2 mV/decade and a detection limit of 5.8 × 10 −11 mol/L (2 ng/mL). The corresponding non-imprinted sensors showed lower

Differential induction of total IgE by two Salmonella enterica serotypes

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Zhanna eKtsoyan

2015-06-01

Full Text Available The main goal of this study was to establish how the inflammation caused by infection with two different Salmonella enterica serotypes, S. Typhimurium and S. Enteritidis, may lead to the predisposition to allergy as measured by total IgE level in the blood. Infection by S. Typhimurium did not affect the systemic IgE concentration while in S. Enteritidis-infected patients there was a significant 3.5-fold increase. This effect was especially profound in patients >4 years old, with up to the eight-fold increase above the norm. The degree of dysbiosis in these two infections measured with the comparative counts of cultivated bacteria showed an inverse relationship with the IgE concentration. Earlier we reported the elevated level of IL-17 in patients infected by S. Enteritidis. In the current study a significant correlation was found between the concentrations of IL-17 and IgE suggesting a possible role played by this cytokine in triggering the production of IgE in response to S. Enteritidis infection.

Development of radioactivity labelling method of new antibody by using the antibody engineering

International Nuclear Information System (INIS)

Yamazaki, Takeshi; Nakajima, Osamu; Saito, Yoshiro; Hachisuka, Akiko; Tanaka, Toichi; Sawada, Junichi

1999-01-01

With an aim to develop a method to produce labelled antibodies with low immunogenicity, two recombinant fusion proteins; scFv-His and scFv-MTβ were produced using gene engineering techniques. The former was constructed with scFv-antibody and histidine hexamer, a metal-chelated protein (or peptide). The latter was done with scFv-antibody and β-domain of metallothionein. Then, antigen-binding activity and metal-binding activity of these fusion proteins were determined using gel-filtration chromatography and ELISA. The main antigen-binding activity of scFv-His preparation was detected in a domain of about 25-30 kDa, which agreed with the peak of 29 kDa corresponding to the presumed molecular weight for the protein. Whereas the antigen-binding activity of scFv-MTβ was found in a domain of 30-35 kDa, which agreed with 32 kDa, the presumed molecular weight of scFv-MTβ. Gel-filtration chromatography of scFv-His preparation after the addition of Cu 2+ ion revealed an optical absorption at 280 nm and a Cu-peak near at 14 kDa. These results suggested that the metal affinity of the histidine-hexamer was too weak to chelate Cu 2+ in a solution. The chromatography of scFv-MTβ preparation added with Cd 2+ showed a peak of Cd appeared around a position of about 20 kDa but the peak was not coincident with that of the antigen-binding activity (ca. 30 kDa), suggesting that the present preparation of scFv-MTβ had no Cd-binding activity due to metal-exchange reaction. Based on these results, problems on the production of recombinant scFv-antibody fused with metal-binding domain of cystein-binding type or histidine-binding one were discussed. (M.N.)

Microarray-based IgE detection in tears of patients with vernal keratoconjunctivitis.

Science.gov (United States)

Leonardi, Andrea; Borghesan, Franco; Faggian, Diego; Plebani, Mario

2015-11-01

A specific allergen sensitization can be demonstrated in approximately half of the vernal keratoconjunctivitis (VKC) patients by conventional allergic tests. The measurement of specific IgE in tears using a multiplex allergen microarray may offer advantages to identify local sensitization to a specific allergen. In spring-summer 2011, serum and tears samples were collected from 10 active VKC patients (three females, seven males) and 10 age-matched normal subjects. Skin prick test, symptoms score and full ophthalmological examination were performed. Specific serum and tear IgE were assayed using ImmunoCAP ISAC, a microarray containing 103 components derived from 47 allergens. Normal subjects resulted negative for the presence of specific IgE both in serum and in tears. Of the 10 VKC patients, six resulted positive to specific IgE in serum and/or tears. In three of these six patients, specific IgE was found positive only in tears. Cross-reactivity between specific markers was found in three patients. Grass, tree, mites, animal but also food allergen-specific IgE were found in tears. Conjunctival provocation test performed out of season confirmed the specific local conjunctival reactivity. Multiple specific IgE measurements with single protein allergens using a microarray technique in tear samples are a useful, simple and non-invasive diagnostic tool. ImmunoCAP ISAC detects allergen sensitization at component level and adds important information by defining both cross- and co-sensitization to a large variety of allergen molecules. The presence of specific IgE only in tears of VKC patients reinforces the concept of possible local sensitization. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

At least two Fc Neu5Gc residues of monoclonal antibodies are required for binding to anti-Neu5Gc antibody

OpenAIRE

Yu, Chuanfei; Gao, Kai; Zhu, Lei; Wang, Wenbo; Wang, Lan; Zhang, Feng; Liu, Chunyu; Li, Meng; Wormald, Mark R.; Rudd, Pauline M.; Wang, Junzhi

2016-01-01

Two non-human glycan epitopes, galactose-Į-1,3-galactose (Į-gal) and Neu5Gc-Į-2-6-galactose (Neu5Gc) have been shown to be antigenic when attached to Fab oligosaccharides of monoclonal antibodies (mAbs) , while Į-gal attached to Fc glycans were not. However, the antigenicity of Neu5Gc on the Fc glycans remains unclear in the context that most mAbs carry only Fc glycans. After studying two clinical mAbs carrying significant amounts of Fc Neu5Gc, we show that their binding activity with anti-Ne...

Antibody or Antibody Fragments: Implications for Molecular Imaging and Targeted Therapy of Solid Tumors

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Katerina T. Xenaki

2017-10-01

Full Text Available The use of antibody-based therapeutics has proven very promising for clinical applications in cancer patients, with multiple examples of antibodies and antibody–drug conjugates successfully applied for the treatment of solid tumors and lymphomas. Given reported recurrence rates, improvements are clearly still necessary. A major factor limiting the efficacy of antibody-targeted cancer therapies may be the incomplete penetration of the antibody or antibody–drug conjugate into the tumor. Incomplete tumor penetration also affects the outcome of molecular imaging, when using such targeting agents. From the injection site until they arrive inside the tumor, targeting molecules are faced with several barriers that impact intratumoral distribution. The primary means of antibody transport inside tumors is based on diffusion. The diffusive penetration inside the tumor is influenced by both antibody properties, such as size and binding affinity, as well as tumor properties, such as microenvironment, vascularization, and targeted antigen availability. Engineering smaller antibody fragments has shown to improve the rate of tumor uptake and intratumoral distribution. However, it is often accompanied by more rapid clearance from the body and in several cases also by inherent destabilization and reduction of the binding affinity of the antibody. In this perspective, we discuss different cancer targeting approaches based on antibodies or their fragments. We carefully consider how their size and binding properties influence their intratumoral uptake and distribution, and how this may affect cancer imaging and therapy of solid tumors.

Human tonsillar IgE biosynthesis in vitro. I. Enhancement of IgE and IgG synthesis in the presence of pokeweed mitogen by T-cell irradiation

International Nuclear Information System (INIS)

Ohta, K.; Manzara, T.; Harbeck, R.J.; Kirkpatrick, C.H.

1982-01-01

A study of the events regulating human IgE biosynthesis in vitro was undertaken with tonsillar lymphocytes. IgG synthesis was also studied to evaluate the specificity of our observations. T-cell irradiation significantly enhanced synthesis of IgE by pokeweed mitogen (PWM)-stimulated B cells from 12 of 18 donors and IgG in all 18 donors. This enhancement was the result of de novo immunoglobulin synthesis, since the amount of IgE and IgG spontaneously released from lysed and lysed-and-cultured mononuclear cells was significantly less than that detected in the cell cultures, and the augmentation was completely ablated by the treatment of the cells with cycloheximide or mitomycin C. Enhancement was also dependent on the presence of PWM; T-cell irradiation did not enhance IgE synthesis in unstimulated cultures. Moreover, this enhancement was also observed in the co-cultures of B cells and allogeneic irradiated T cells. These observations suggest that radiosensitive T cells exert a suppressive activity that contributes to regulation of human IgE and IgG synthesis and that the suppressor function as well as the helper function can overcome allogeneic disparities

Syntaxin-4 is essential for IgE secretion by plasma cells

Energy Technology Data Exchange (ETDEWEB)

Rahman, Arman; DeCourcey, Joseph; Larbi, Nadia Ben [Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland); Loughran, Sinéad T.; Walls, Dermot [School of Biotechnology and National Centre for Sensor Research, Dublin City University (Ireland); Loscher, Christine E., E-mail: christine.loscher@dcu.ie [Immunomodulation Group, School of Biotechnology, Dublin City University (Ireland)

2013-10-11

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE within the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients.

Syntaxin-4 is essential for IgE secretion by plasma cells

International Nuclear Information System (INIS)

Rahman, Arman; DeCourcey, Joseph; Larbi, Nadia Ben; Loughran, Sinéad T.; Walls, Dermot; Loscher, Christine E.

2013-01-01

Highlights: •Knock-down of syntaxin-4 in U266 plasma cells resulted in reduction of IgE secretion. •Knock-down of syntaxin-4 also leads to the accumulation of IgE in the cell. •Immuno-fluorescence staining shows co-localisation of IgE and syntaxin-4 in U266 cells. •Findings suggest a critical requirement for syntaxin-4 in IgE secretion from plasma cells. -- Abstract: The humoral immune system provides a crucial first defense against the invasion of microbial pathogens via the secretion of antigen specific immunoglobulins (Ig). The secretion of Ig is carried out by terminally differentiated B-lymphocytes called plasma cells. Despite the key role of plasma cells in the immune response, the mechanisms by which they constitutively traffic large volumes of Ig out of the cell is poorly understood. The involvement of Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in the regulation of protein trafficking from cells has been well documented. Syntaxin-4, a member of the Qa SNARE syntaxin family has been implicated in fusion events at the plasma membrane in a number of cells in the immune system. In this work we show that knock-down of syntaxin-4 in the multiple myeloma U266 human plasma cell line results in a loss of IgE secretion and accumulation of IgE within the cells. Furthermore, we show that IgE co-localises with syntaxin-4 in U266 plasma cells suggesting direct involvement in secretion at the plasma membrane. This study demonstrates that syntaxin-4 plays a critical role in the secretion of IgE from plasma cells and sheds some light on the mechanisms by which these cells constitutively traffic vesicles to the surface for secretion. An understanding of this machinery may be beneficial in identifying potential therapeutic targets in multiple myeloma and autoimmune disease where over-production of Ig leads to severe pathology in patients

Low prevalence of antibodies and other plasma factors binding to CC chemokines and IL-2 in HIV-positive patients

DEFF Research Database (Denmark)

Meyer, C N; Svenson, M; Larsen, Carsten Schade

2000-01-01

Neutralizing cytokine antibodies are found in healthy and diseased individuals, including patients treated with recombinant cytokines. Identification of CCR-5 as co-receptor for HIV has focused interest on CC chemokines and their potential therapeutic use. Chemokine-binding components in plasma...

An anti vimentin antibody promotes tube formation

DEFF Research Database (Denmark)

Jørgensen, Mathias Lindh; Møller, Carina Kjeldahl; Rasmussen, Lasse

2017-01-01

antibody technology, promotes tube formation of endothelial cells in a 2D matrigel assay. By binding vimentin, the antibody increases the tube formation by 21% after 5 hours of incubation. Addition of the antibody directly to cultured endothelial cells does not influence endothelial cell migration...... or proliferation. The enhanced tube formation can be seen for up to 10 hours where after the effect decreases. It is shown that the antibody-binding site is located on the coil 2 domain of vimentin. To our knowledge this is the first study that demonstrates an enhanced tube formation by binding vimentin in a 2D...

Phthalate treatment does not influence levels of IgE or Th2 cytokines in B6C3F1 mice

International Nuclear Information System (INIS)

Butala, John H.; David, Raymond M.; Gans, Gerhard; McKee, Richard H.; Guo, Tai L.; Peachee, Vanessa L.; White, Kimber L.

2004-01-01

parameters, demonstrating responsiveness of the assay. Another control, dinitrochlorobenzene (DNCB), a contact sensitizer, also responded as expected, producing smaller but statistically significant increases in IgE and in mRNA for IL-4 and IL-13 but not in the levels of these cytokines. In summary, treatment with DEHP, DINP, DIHP, and BBP did not result in significant elevations in total serum IgE, IL-4, or IL-13. As such it is unlikely that these substances would produce antibody-mediated respiratory allergy

In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis.

Science.gov (United States)

Salinas-Jazmín, Nohemi; González-González, Edith; Vásquez-Bochm, Luz X; Pérez-Tapia, Sonia M; Velasco-Velázquez, Marco A

2017-05-04

Therapeutic monoclonal antibodies (mAbs) are relevant to the treatment of different pathologies, including cancers. The development of biosimilar mAbs by pharmaceutical companies is a market opportunity, but it is also a strategy to increase drug accessibility and reduce therapy-associated costs. The protocols detailed here describe the evaluation of target binding and CDC induction by rituximab in Daudi cells. These two functions require different structural regions of the antibody and are relevant to the clinical effect induced by rituximab. The protocols allow the side-to-side comparison of a reference rituximab and a marketed rituximab biosimilar. The evaluated products showed differences both in target binding and CDC induction, suggesting that there are underlying physicochemical differences and highlighting the need to analyze the impact of those differences in the clinical setting. The methods reported here constitute simple and inexpensive in vitro models for the evaluation of the activity of rituximab biosimilars. Thus, they can be useful during biosimilar development, as well as for quality control in biosimilar production. Furthermore, the presented methods can be extrapolated to other therapeutic mAbs.

Method of stably radiolabeling antibodies with technetium and rhenium

International Nuclear Information System (INIS)

Paik, C.H.; Reba, R.C.; Eckelman, W.C.

1987-01-01

A method is described for labeling antibodies or antibody fragments with radionuclides of technetium or rhenium to obtain stable labeling, comprising: reacting a reduced radioisotope of technetium or rhenium with an antibody or antibody fragment, or a diethylenetriaminepentaacetic acid conjugated antibody or antibody fragment, in the presence of free or carrier-bound diethylenetriaminepentaacetic acid (DTPA). The amount of DTPA is sufficient to substantially completely inhibit binding of the reduced technetium or rhenium to nonstable binding sites of the antibody or antibody fragment, or the DTPA-conjugated antibody or antibody fragment. The resultant stably labeled antibody or antibody fragment, or DTPA[conjugated antibody or antibody fragment is recovered

A monoclonal antibody interferes with TIMP-2 binding and incapacitates the MMP-2-activating function of multifunctional, pro-tumorigenic MMP-14/MT1-MMP

DEFF Research Database (Denmark)

Shiryaev, S A; Remacle, A G; Golubkov, V S

2013-01-01

Matrix metalloproteinases (MMPs) and, especially membrane type 1 (MT1)-MMP/MMP-14, are promising drug targets in malignancies. In contrast with multiple small-molecule and protein pan-inhibitors of MT1-MMP cleavage activity, the murine 9E8 monoclonal antibody targets the MMP-2-activating function...... of cellular MT1-MMP alone, rather than the general proteolytic activity and the pro-migratory function of MT1-MMP. Furthermore, the antibody does not interact in any detectable manner with other members of the membrane type (MT)-MMP family. The mechanism of this selectivity remained unknown. Using mutagenesis......, binding and activity assays, and modeling in silico, we have demonstrated that the 9E8 antibody recognizes the MT-loop structure, an eight residue insertion that is specific for MT-MMPs and that is distant from the MT1-MMP active site. The binding of the 9E8 antibody to the MT-loop, however, prevents...

A study of the human immune response to Lolium perenne (rye) pollen and its components, Lol p I and Lol p II (Rye I and Rye II). II. Longitudinal variation of antibody levels in relation to symptomatology and pollen exposure and correction of seasonally elevated antibody levels to basal values.

Science.gov (United States)

Freidhoff, L R; Ehrlich-Kautzky, E; Meyers, D A; Marsh, D G

1987-11-01

This study used a standardized, dialyzed, Lolium perenne (ryegrass) pollen extract and two of its well-characterized components, Lol p I (Rye I) and Lol p II (Rye II), to characterize the longitudinal variation of both IgE and IgG antibody (Ab) levels, as well as total serum IgE levels, in 20 grass-allergic subjects followed for 13 months. Ab levels declined toward a basal level just before, and increased just after, the grass-pollination season, returning to the same basal level just before the next grass-pollination season. The least complex allergen, Lol II, demonstrated the most uniform pattern of variation in both IgE and IgG Ab levels. Total serum IgE levels demonstrated the least regular pattern of variation. Grass-pollen counts were strongly correlated with symptom-medication scores for these subjects (rs = 0.87). Initial values were correlated with the rise in total IgE and IgE Ab to Lol II across the grass-pollen season. Skin test results were correlated with initial IgE Ab levels for L. perenne pollen extract and Lol II. Finally, a procedure for correcting IgE Ab levels to basal values was proposed and tested. The correction procedure, for each IgE Ab, was based on the average rise during the grass-pollination season (or average decline after the grass-pollination season) observed for all subjects with that IgE Ab.

Nederlandse richtlijn Chronische urticaria - Behandeling met omalizumab

NARCIS (Netherlands)

Van Den Elzen, M. T.; Urgert, M. C.; Van Doorn, M. B A; Tupker, R. A.; Knulst, A. C.; Van Zuuren, E. J.

2015-01-01

The Dutch guideline Chronic Urticaria aims to present a stepped-care model for the treatment of chronic spontaneous urticaria (CSU). In this manuscript omalizumab is discussed as a treatment option. Omalizumab is a humanized monoclonal antibody that selectively binds to immunoglobulin E (IgE). We

Template-directed covalent conjugation of DNA to native antibodies, transferrin and other metal-binding proteins

Science.gov (United States)

Rosen, Christian B.; Kodal, Anne L. B.; Nielsen, Jesper S.; Schaffert, David H.; Scavenius, Carsten; Okholm, Anders H.; Voigt, Niels V.; Enghild, Jan J.; Kjems, Jørgen; Tørring, Thomas; Gothelf, Kurt V.

2014-09-01

DNA-protein conjugates are important in bioanalytical chemistry, molecular diagnostics and bionanotechnology, as the DNA provides a unique handle to identify, functionalize or otherwise manipulate proteins. To maintain protein activity, conjugation of a single DNA handle to a specific location on the protein is often needed. However, preparing such high-quality site-specific conjugates often requires genetically engineered proteins, which is a laborious and technically challenging approach. Here we demonstrate a simpler method to create site-selective DNA-protein conjugates. Using a guiding DNA strand modified with a metal-binding functionality, we directed a second DNA strand to the vicinity of a metal-binding site of His6-tagged or wild-type metal-binding proteins, such as serotransferrin, where it subsequently reacted with lysine residues at that site. This method, DNA-templated protein conjugation, facilitates the production of site-selective protein conjugates, and also conjugation to IgG1 antibodies via a histidine cluster in the constant domain.

Prolonged in vivo residence times of llama single-domain antibody fragments in pigs by binding to porcine immunoglobulins

NARCIS (Netherlands)

Harmsen, M.M.; Solt, van C.B.; Fijten, H.P.D.; Setten, van M.C.

2005-01-01

The therapeutic parenteral application of llama single-domain antibody fragments (VHHs) is hampered by their small size, resulting in a fast elimination from the body. Here we describe a method to increase the serum half-life of VHHs in pigs by fusion to another VHH binding to porcine immunoglobulin

Structural Characterization of Peptide Antibodies

DEFF Research Database (Denmark)

Chailyan, Anna; Marcatili, Paolo

2015-01-01

The role of proteins as very effective immunogens for the generation of antibodies is indisputable. Nevertheless, cases in which protein usage for antibody production is not feasible or convenient compelled the creation of a powerful alternative consisting of synthetic peptides. Synthetic peptides...... can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery....... To better understand the underlying mechanisms of antibody-antigen interaction here we present a pipeline developed by us to structurally classify immunoglobulin antigen binding sites and to infer key sequence residues and other variables that have a prominent role in each structural class....

The original Pathologische Anatomie Leiden-Endothelium monoclonal antibody recognizes a vascular endothelial growth factor binding site within neuropilin-1

NARCIS (Netherlands)

Jaalouk, Diana E.; Ozawa, Nfichael G.; Sun, Jessica; Lahdenranta, Johanna; Schlingemann, Reinier O.; Pasqualini, Renata; Arap, Wadih

2007-01-01

For two decades, the antigen recognized by the Pathologische Anatomie Leiden-Endothelium (PAL-E) monoclonal antibody, a standard vascular endothelial cell marker, has remained elusive. Here, we used a combinatorial phage display-based approach ("epitope mapping") to select peptides binding to the

Heparin binding domain of antithrombin III: Characterization using a synthetic peptide directed polyclonal antibody

International Nuclear Information System (INIS)

Smith, J.W.; Dey, B.; Knauer, D.J.

1990-01-01

Antithrombin III (ATIII) is a plasma-borne serine protease inhibitor that apparently forms covalent complexes with thrombin. The interaction between ATIII and thrombin is enhanced several thousandfold by the glycosaminoglycan, heparin. The authors have previously proposed that the heparin binding site of ATIII residues within a region extending from amino acid residues 114-156. Computer-assisted analysis of this region revealed the presence of a 22 amino acid domain (residues 124-145), part of which shows a strong potential for the formation of an amphipathic helix: hydrophobic on one face and highly positively charged on the other. In the presence studies, polyclonal antisera were generated against a synthetic peptide corresponding to residues 124-145 in native human ATIII. Affinity-purified IgG from these antisera, as well as monovalent Fab's derived from them, specifically blocked the binding of heparin to ATIII. Additionally, occupancy of the heparin binding site by these same monovalent and bivalent IgG's at least partially substituted for heparin, accelerating linkage formation between ATIII and thrombin. These results provide the first immunological evidence that region 124-145 is directly involved in the binding of heparin to ATIII and that an antibody-induced conformational change within this region can mediate ATIII activation

Aeroallergen and food IgE sensitization and local and systemic inflammation in asthma.

Science.gov (United States)

Patelis, A; Janson, C; Borres, M P; Nordvall, L; Alving, K; Malinovschi, A

2014-03-01

We recently reported an independent association between IgE sensitization to food allergens and increased airway inflammation, assessed by fraction of exhaled nitric oxide (FeNO), in a population-based study (J Allergy Clin Immunol, 130, 2012, 397). Similar studies have not been performed in populations with asthma. The aim of the present study was to investigate the allergic sensitization profile in asthmatics and examine FeNO, airway responsiveness and blood eosinophilia in relation to type and degree of IgE sensitization. FeNO, airway responsiveness, blood eosinophil count (B-Eos) and IgE sensitization to food allergens and aeroallergens were determined in 408 subjects with asthma, aged 10-34 years. Asthmatics had higher prevalence of IgE sensitization against all allergens than controls (P < 0.001). Mite, pollen, furry animal, mould and food sensitizations were each associated with increased FeNO, airway responsiveness and B-Eos in asthmatics. IgE sensitization to mould, furry animals and food allergens was independently related to FeNO (all P < 0.05) after adjustment for age, sex, height, smoking history and medication. IgE sensitization to mould (P < 0.001) and furry animals (P = 0.02) was related to airway responsiveness in a similar model. Finally, IgE sensitization to mould (P = 0.001), furry animals (P < 0.001) and food allergens (P < 0.001) was independently related to B-Eos. Independent effects of IgE sensitization to aeroallergens (furry animals and mould) and food allergens were found on both local and systemic markers of inflammation in asthma. The finding regarding food IgE sensitization is novel, and a clinical implication might be that even food sensitization must be assessed to fully understand inflammation patterns in asthma. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Boronated monoclonal antibody conjugates for neutron capture therapy

International Nuclear Information System (INIS)

Borg, D.C.; Elmore, J.J. Jr.; Ferrone, S.

1986-01-01

This paper describes the effectiveness of 10 B-labeled monoclonal antibodies against Colo-38 human melanoma in vitro. The authors obtained high boron to antibody ratios while maintaining antibody activity by using dextran intermediate carriers to link 10 B to the antibody. They developed a double cell quasi-competitive binding bioassay to minimize the effects of nonspecific binding of boronated complexes to cells. 1 fig., 2 tabs

Immunoglobulin-E reactivity to wine glycoproteins in heavy drinkers

DEFF Research Database (Denmark)

Gonzalez-Quintela, Arturo; Gomez-Rial, Jose; Valcarcel, Catalina

2011-01-01

and biological significance of IgE antibodies to N-glycans from wine glycoproteins in heavy drinkers. A structured questionnaire, skin prick tests, serum IgE levels, IgE-immunoblotting to wine extracts, and basophil activation tests were used to characterize 20 heavy drinkers and 10 control subjects. Eleven...... heavy drinkers (55%) showed IgE binding to proteins in wine extracts. The proteins were identified by mass spectrometry as grape-derived vacuolar invertase and thaumatin-like protein. Immunoblot reactivity was closely associated with the presence of IgE to CCDs and was inhibited by preincubation...... with a glycoconjugate containing bromelain-type N-glycans. The same conjugate, CCD-bearing allergens, and wine extracts activated basophils in patients with high-titer CCD-specific IgE but not in healthy controls. There was no relationship between immunoblot reactivity and consumption of any specific type of wine...

Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

Directory of Open Access Journals (Sweden)

Gomes Maria A

2010-03-01

Full Text Available Abstract Background Human amoebiasis is caused by the parasitic protozoan Entamoeba histolytica that lives in the large intestine of hosts, where can produce asymptomatic colonization until severe invasive infections with blood diarrhea and spreading to other organs. The amoebic abscesses in liver are the most frequent form of amoebiasis outside intestine and still there are doubts about the pathogenic mechanisms involved in their formation. In this study we evaluated the in situ binding of antibodies, C3 and C9 complement components on trophozoites, in livers of hamsters infected with E. histolytica or E. dispar. These parameters were correlated with the extension of the hepatic lesions observed in these animals and with trophozoites survivor. Methods Hamsters were inoculated intra-hepatically with 100,000 trophozoites of E. histolytica or E. dispar strain and necropsied 12, 24, 48, 72, 144 and 192 h after inoculation. Antibodies, C3 and C9 binding to trophozoites were detected by immunohistochemistry. The estimation of the necrosis area and the number of labeled trophozoites was performed using digital morphometry analysis. Results In the liver sections of animals inoculated with the amoebas, the binding of antibodies to E. histolytica trophozoites was significantly lower than to E. dispar trophozoites. Trophozoites of E. dispar were also more frequently vacuolated and high labeled cellular debris observed in the lesions. Positive diffuse reaction to C3 complement component was more intense in livers of animals inoculated with E. histolytica after 24 and 72 h of infection. C3(+ and C9(+ trophozoites were detected in the vascular lumen, granulomas and inside and in the border of necrotic areas of both infected group animals. C3(+ and C9(+ trophozoite debris immunostaining was higher in livers of E. dispar than in livers of E. histolytica. A positive correlation between necrotic areas and number of C9(+ trophozoites was observed in animals

Intranasal sensitization with Blomia Tropicalis antigens induces allergic responses in mice characterized by elevated antigen-specific and non-specific serum ige and peripheral blood eosinophil counts Sensibilização intranasal com antígenos de Blomia tropicalis induz respostas alérgicas em camundos caracterizadas pela elevada contagem de soro IgE antígeno-específico e não específico e de eosinófilos no sangue periférico

Directory of Open Access Journals (Sweden)

Fumiko Takeda

2004-02-01

Full Text Available In order to evaluate the potential allergenicity of Blomia tropicalis (Bt antigen, IgE production of both specific and non-specific for Bt antigen was monitored in BALB/c mice after exposure to the antigen by nasal route. It was evidenced that B. tropicalis contains a functional allergen in its components. The allergenic components, however, when administered intranasally without any adjuvant, did not function to induce IgE response within a short period. On the other hand, intranasal inoculation of Bt antigens augmented serum IgE responses in mice pretreated by a subcutaneous priming injection of the same antigens. Inoculation of Bt antigen without subcutaneous priming injections induced IgE antibody production only when the antigen was continuously administered for a long period of over 24 weeks. Even when the priming injection was absent, the Bt antigen inoculated with cholera toxin (CT as a mucosal adjuvant also significantly augmented the Bt antigen-specific IgE responses depending on the dose of CT co-administered. The present study also demonstrated that Bt antigen/CT-inoculated mice showed increased non-specific serum IgE level and peripheral blood eosinophil rates without noticeable elevations of the total leukocyte counts. The immunoblot analysis demonstrated 5 main antigenic components reactive to IgE antibodies induced. These components at about 44-64 kDa position were considered to be an important candidate antigen for diagnosis of the mite-related allergy.Para avaliar a capacidade alergizante do antígeno da Blomia tropicalis (Bt a produção de IgE específica e não específica a antígeno Bt foi monitorada em camundongos BALB/c após exposição ao antígeno por via nasal. Foi evidenciado que Bt contem um alérgeno funcional em seus componentes. Os componentes alergênicos entretanto, quando administrados por via intra-nasal, sem qualquer adjuvante, não induzem resposta IgE durante um pequeno período. Por outro lado, a inocula

The PD-1/PD-L1 complex resembles the antigen-binding Fv domains of antibodies and T cell receptors

Energy Technology Data Exchange (ETDEWEB)

Lin, David Yin-wei; Tanaka, Yoshimasa; Iwasaki, Masashi; Gittis, Apostolos G.; Su, Hua-Poo; Mikami, Bunzo; Okazaki, Taku; Honjo, Tasuku; Minato, Nagahiro; Garboczi, David N. (NIH); (Kyoto)

2008-07-29

Signaling through the programmed death 1 (PD-1) inhibitory receptor upon binding its ligand, PD-L1, suppresses immune responses against autoantigens and tumors and plays an important role in the maintenance of peripheral immune tolerance. Release from PD-1 inhibitory signaling revives 'exhausted' virus-specific T cells in chronic viral infections. Here we present the crystal structure of murine PD-1 in complex with human PD-L1. PD-1 and PD-L1 interact through the conserved front and side of their Ig variable (IgV) domains, as do the IgV domains of antibodies and T cell receptors. This places the loops at the ends of the IgV domains on the same side of the PD-1/PD-L1 complex, forming a surface that is similar to the antigen-binding surface of antibodies and T cell receptors. Mapping conserved residues allowed the identification of residues that are important in forming the PD-1/PD-L1 interface. Based on the structure, we show that some reported loss-of-binding mutations involve the PD-1/PD-L1 interaction but that others compromise protein folding. The PD-1/PD-L1 interaction described here may be blocked by antibodies or by designed small-molecule drugs to lower inhibitory signaling that results in a stronger immune response. The immune receptor-like loops offer a new surface for further study and potentially the design of molecules that would affect PD-1/PD-L1 complex formation and thereby modulate the immune response.

Effect of trastuzumab interchain disulfide bond cleavage on Fcγ receptor binding and antibody-dependent tumour cell phagocytosis.

Science.gov (United States)

Suzuki, Mami; Yamanoi, Ayaka; Machino, Yusuke; Ootsubo, Michiko; Izawa, Ken-ichi; Kohroki, Junya; Masuho, Yasuhiko

2016-01-01

The Fc domain of human IgG1 binds to Fcγ receptors (FcγRs) to induce effector functions such as phagocytosis. There are four interchain disulfide bonds between the H and L chains. In this study, the disulfide bonds within the IgG1 trastuzumab (TRA), which is specific for HER2, were cleaved by mild S-sulfonation or by mild reduction followed by S-alkylation with three different reagents. The cleavage did not change the binding activities of TRA to HER2-bearing SK-BR-3 cells. The binding activities of TRA to FcγRIIA and FcγRIIB were greatly enhanced by modification with mild reduction and S-alkylation with ICH2CONH2 or N-(4-aminophenyl) maleimide, while the binding activities of TRA to FcγRI and FcγRIIIA were decreased by any of the four modifications. However, the interchain disulfide bond cleavage by the different modifications did not change the antibody-dependent cell-mediated phagocytosis (ADCP) of SK-BR-3 cells by activated THP-1 cells. The order of FcγR expression levels on the THP-1 cells was FcγRII > FcγRI > FcγRIII and ADCP was inhibited by blocking antibodies against FcγRI and FcγRII. These results imply that the effect of the interchain disulfide bond cleavage on FcγRs binding and ADCP is dependent on modifications of the cysteine residues and the FcγR isotypes. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Development of Broadly Neutralizing Antibody Mimitopes for Characterization of CRF01_AE HIV-1 Antibody Responses

Directory of Open Access Journals (Sweden)

Jesse V. Schoen

2017-10-01

Full Text Available Mapping humoral immune responses to HIV-1 over the course of natural infection is important in understanding epitope exposure in relation to elicitation of broadly neutralizing antibodies (bNAbs, which is considered imperative for effective vaccine design. When analyzing HIV-specific immune responses, the antibody binding profiles may be a correlate for functional antibody activity. In this study, we utilized phage display technology to identify novel mimitopes that may represent Env epitope structures bound by bNAbs directed at V1V2 and V3 domains, CD4 binding site (CD4bs and the membrane proximal external region (MPER of Env. Mimitope sequence motifs were determined for each bNAb epitope. Given the ongoing vaccine development efforts in Thailand, these mimitopes that represent CD4bs and MPER epitopes were used to map immune responses of HIV-1 CRF01_AE-infected individuals with known neutralizing responses from two distinct time periods, 1996-98 and 2012-15. The more contemporary cohort showed an increase in binding breadth with binding observed for all MPER and CD4bs mimitopes, while the older cohort showed only 75% recognition of the CD4bs mimitopes and no MPER mimotope binding. Furthermore, mimitope binding profiles correlated significantly with magnitude (p=0.0036 and breadth (p=0.0358 of neutralization of a multi-subtype Tier 1 panel of pseudoviruses. These results highlight the utility of this mimitope mapping approach for detecting human plasma IgG-specificities that target known neutralizing antibody epitopes, and may also provide an indication of the plasticity of antibody binding within HIV-1 Env neutralization determinants.

Radioimmunological proof of thyroglobulin antibodies in humans by the use of a double antibody method

International Nuclear Information System (INIS)

Waller, V.

1982-01-01

Thyroid antibodies, especially thyroglobulin antibodies, allow themselves to be proven with the double antibody method, in competitive radio binding assays and with the solid phase technique. These methods offer advantages relative to sensitivity and quantifiability. In this work a sensitive radioimmunoassay as a double antibody method was worked out whereby a 125 I-thyroglobulin/thyroglobulin antibody immune complex was precipitated out using anti-human immunoglobulin. The measured results from the radioimmunoassay show a good correlation with the results of the immune histological findings. A high to very high Tg antibody level occurs with autoimmune thyroiditis (80%), primary hypothyroidism (74%) and hyperthyroidism (70%). The control values with healthy people came to less than 5% specific binding. In correlation with the results of other authors this method is advantageous relative to test start and evaluation procedures. (orig.) [de

Effect of praziquantel treatment of Schistosoma mansoni during pregnancy on intensity of infection and antibody responses to schistosome antigens

DEFF Research Database (Denmark)

Tweyongyere, Robert; Mawa, Patrice A.; Emojong, Nicholas O.

2009-01-01

with those first treated after delivery (undetected (88.5%), light (10.6%), moderate (0.9%) and heavy (0%), p = 0.16). Parasite specific antibody levels were lower during pregnancy than after delivery. Praziquantel treatment during pregnancy boosted anti-worm IgG isotypes and to a lesser extent Ig......E, but these boosts were less pronounced than in women whose treatment was delayed until after delivery. Praziquantel had limited effects on antibodies against egg antigens. Conclusion S mansoni antigen-specific antibody levels and praziquantel-induced boosts in antibody levels were broadly suppressed during...

Determination of High-affinity Antibody-antigen Binding Kinetics Using Four Biosensor Platforms.

Science.gov (United States)

Yang, Danlin; Singh, Ajit; Wu, Helen; Kroe-Barrett, Rachel

2017-04-17

Label-free optical biosensors are powerful tools in drug discovery for the characterization of biomolecular interactions. In this study, we describe the use of four routinely used biosensor platforms in our laboratory to evaluate the binding affinity and kinetics of ten high-affinity monoclonal antibodies (mAbs) against human proprotein convertase subtilisin kexin type 9 (PCSK9). While both Biacore T100 and ProteOn XPR36 are derived from the well-established Surface Plasmon Resonance (SPR) technology, the former has four flow cells connected by serial flow configuration, whereas the latter presents 36 reaction spots in parallel through an improvised 6 x 6 crisscross microfluidic channel configuration. The IBIS MX96 also operates based on the SPR sensor technology, with an additional imaging feature that provides detection in spatial orientation. This detection technique coupled with the Continuous Flow Microspotter (CFM) expands the throughput significantly by enabling multiplex array printing and detection of 96 reaction sports simultaneously. In contrast, the Octet RED384 is based on the BioLayer Interferometry (BLI) optical principle, with fiber-optic probes acting as the biosensor to detect interference pattern changes upon binding interactions at the tip surface. Unlike the SPR-based platforms, the BLI system does not rely on continuous flow fluidics; instead, the sensor tips collect readings while they are immersed in analyte solutions of a 384-well microplate during orbital agitation. Each of these biosensor platforms has its own advantages and disadvantages. To provide a direct comparison of these instruments' ability to provide quality kinetic data, the described protocols illustrate experiments that use the same assay format and the same high-quality reagents to characterize antibody-antigen kinetics that fit the simple 1:1 molecular interaction model.

Epigenome-wide DNA methylation study of IgE concentration in relation to self-reported allergies.

Science.gov (United States)

Ek, Weronica E; Ahsan, Muhammad; Rask-Andersen, Mathias; Liang, Liming; Moffatt, Miriam F; Gyllensten, Ulf; Johansson, Åsa

2017-04-01

Epigenetic mechanisms are critical for normal immune development and epigenetic alterations might therefore be possible contributors to immune diseases. To investigate if DNA methylation in whole blood is associated with total and allergen-specific IgE levels. We performed an epigenome-wide association study to investigate the association between DNA methylation and IgE level, allergen-specific IgE and self-reported immune diseases and allergies in 728 individuals. We identified and replicated 15 CpG sites associated with IgE, mapping to biologically relevant genes, including ACOT7, ILR5A, KCNH2, PRG2 and EPX. A total of 331 loci were associated with allergen-specific IgE, but none of these CpG sites were associated with self-reported allergies and immune diseases. This study shows that IgE levels are associated with DNA methylation levels at numerous CpG sites, which might provide new leads for investigating the links between IgE and allergic inflammation.

Mouse Chromosome 4 Is Associated with the Baseline and Allergic IgE Phenotypes

Directory of Open Access Journals (Sweden)

Cynthia Kanagaratham

2017-08-01

Full Text Available Regulation of IgE concentration in the blood is a complex trait, with high concentrations associated with parasitic infections as well as allergic diseases. A/J strain mice have significantly higher plasma concentrations of IgE, both at baseline and after ovalbumin antigen exposure, when compared to C57BL/6J strain mice. Our objective was to determine the genomic regions associated with this difference in phenotype. To achieve this, we used a panel of recombinant congenic strains (RCS derived from A/J and C57BL/6J strains. We measured IgE in the RCS panel at baseline and following allergen exposure. Using marker by marker analysis of the RCS genotype and phenotype data, we identified multiple regions associated with the IgE phenotype. A single region was identified to be associated with baseline IgE level, while multiple regions wereassociated with the phenotype after allergen exposure. The most significant region was found on Chromosome 4, from 81.46 to 86.17 Mbp. Chromosome 4 substitution strain mice had significantly higher concentration of IgE than their background parental strain mice, C57BL/6J. Our data presents multiple candidate regions associated with plasma IgE concentration at baseline and following allergen exposure, with the most significant one located on Chromosome 4.

The who, where, and when of IgE in allergic airway disease.

Science.gov (United States)

Dullaers, Melissa; De Bruyne, Ruth; Ramadani, Faruk; Gould, Hannah J; Gevaert, Philippe; Lambrecht, Bart N

2012-03-01

Allergic asthma and allergic rhinitis/conjunctivitis are characterized by a T(H)2-dominated immune response associated with increased serum IgE levels in response to inhaled allergens. Because IgE is a key player in the induction and maintenance of allergic inflammation, it represents a prime target for therapeutic intervention. However, our understanding of IgE biology remains fragmentary. This article puts together our current knowledge on IgE in allergic airway diseases with a special focus on the identity of IgE-secreting cells ("who"), their location ("where"), and the circumstances in which they are induced ("when"). We further consider the therapeutic implications of the insights gained. Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Mapping of monoclonal antibody- and receptor-binding domains on human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) using a surface plasmon resonance-based biosensor.

Science.gov (United States)

Laricchia-Robbio, L; Liedberg, B; Platou-Vikinge, T; Rovero, P; Beffy, P; Revoltella, R P

1996-10-01

An automated surface plasmon resonance (SPR)-based biosensor system has been used for mapping antibody and receptor-binding regions on the recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) molecule. A rabbit antimouse IgG1-Fc antibody (RAM.Fc) was coupled to an extended carboxymethylated-hydrogel matrix attached to a gold surface in order to capture an anti-rhGM-CSF monoclonal antibody (MAb) injected over the sensing layer. rhGM-CSF was subsequently injected and allowed to bind to this antibody. Multisite binding assays were then performed, by flowing sequentially other antibodies and peptides over the surface, and the capacity of the latter to interact with the entrapped rhGM-CSF in a multimolecular complex was monitored in real time with SPR. Eleven MAb (all IgG1K), were analyzed: respectively, four antipeptide MAb raised against three distinct epitopes of the cytokine (two clones against residues 14-24, that includes part of the first alpha-helix toward the N-terminal region; one clone against peptide 30-41, an intrahelical loop; and one clone against residues 79-91, including part of the third alpha-helix) and seven antiprotein MAbs raised against the entire rhGM-CSF, whose target native epitopes are still undetermined. In addition, the binding capacity to rhGM-CSF of a synthetic peptide, corresponding to residues 238-254 of the extracellular human GM-CSF receptor alpha-chain, endowed with rhGM-CSF binding activity, was tested. The results from experiments performed with the biosensor were compared with those obtained by a sandwich enzyme-linked immunosorbent assay (ELISA), using the same reagents. The features of the biosensor technology (fully automated, measure in real time, sharpened yes/no response, less background disturbances, no need for washing step or labeling of the reagent) offered several advantages in these studies of MAb immunoreactivity and epitope mapping, giving a much better resolution and enabling more distinct

Work-related allergy and asthma in spice mill workers - The impact of processing dried spices on IgE reactivity patterns.

Science.gov (United States)

van der Walt, Anita; Lopata, Andreas L; Nieuwenhuizen, Natalie E; Jeebhay, Mohamed F

2010-01-01

Three spice mill workers developed work-related allergy and asthma after prolonged exposure to high levels (>10 mg/m(3)) of inhalable spice dust. Patterns of sensitization to a variety of spices and putative allergens were identified. Work-related allergy and asthma were assessed on history, clinical evaluation, pulmonary function and fractional exhaled nitric oxide. Specific IgE reactivity to a range of common inhalant, food and spice allergens was evaluated using ImmunoCAP and allergen microarray. The presence of non-IgE-mediated reactions was determined by basophil stimulation (CAST-ELISA). Specific allergens were identified by immunoblotting to extracts of raw and dried processed garlic, onion and chili pepper. Asthma was confirmed in all 3 subjects, with work-related patterns prominent in worker 1 and 3. Sensitization to multiple spices and pollen was observed in both atopic workers 1 and 2, whereas garlic and chili pepper sensitization featured in all 3 workers. Microarray analysis demonstrated prominent profilin reactivity in atopic worker 2. Immunoblotting demonstrated a 50-kDa cross-reactive allergen in garlic and onion, and allergens of approximately 40 and 52 kDa in chili pepper. Dry powdered garlic and onion demonstrated greater IgE binding. This study demonstrated IgE reactivity to multiple spice allergens in workers exposed to high levels of inhalable spice dust. Processed garlic and onion powder demonstrated stronger IgE reactivity than the raw plant. Atopy and polysensitization to various plant profilins, suggesting pollen-food syndrome, represent additional risk factors for sensitizer-induced work-related asthma in spice mill workers. 2010 S. Karger AG, Basel.

Protein adsorption/desorption and antibody binding stoichiometry on silicon interferometric biosensors examined with TOF-SIMS

Science.gov (United States)

Gajos, Katarzyna; Budkowski, Andrzej; Petrou, Panagiota; Pagkali, Varvara; Awsiuk, Kamil; Rysz, Jakub; Bernasik, Andrzej; Misiakos, Konstantinos; Raptis, Ioannis; Kakabakos, Sotirios

2018-06-01

Time-of-flight secondary ion mass spectrometry has been employed to examine, with biomolecular discrimination, sensing arm areas (20 μm × 600 μm) of integrated onto silicon chips Mach-Zehnder interferometers aiming to optimize their biofunctionalization with regard to indirect immunochemical (competitive) detection of ochratoxin A. Sensing areas are examined after: modification with (3-aminopropyl)triethoxysilane, spotting of OTA-ovalbumin conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin, reaction with OTA-specific mouse monoclonal antibody followed by goat anti-mouse IgG secondary antibody. Component mass loadings of all proteins involved in immunodetection are determined from TOF-SIMS micro-analysis combined with ellipsometry of planar surfaces. These data show that partial desorption of surface-bound probe and blocking protein takes place upon primary immunoreaction to a degree that depends on probe concentration in spotting solution. Taking into account this desorption, apparent binding stoichiometry of both antibodies in immune complexes formed onto chip surface is determined more accurately than the respective evaluation based on real-time sensor response. In addition, mass loadings for probe and secondary antibody is observed to saturate for optimum probe concentrations. Also, principal component analysis of TOF-SIMS data could resolve both immunoreactions and biofunctionalization and discriminate surfaces prepared with optimum probe concentrations from those prepared using suboptimum ones.

Protein adsorption/desorption and antibody binding stoichiometry on silicon interferometric biosensors examined with TOF-SIMS

KAUST Repository

Gajos, Katarzyna

2018-03-05

Time-of-flight secondary ion mass spectrometry has been employed to examine, with biomolecular discrimination, sensing arm areas (20 μm x 600 μm) of integrated onto silicon chips Mach-Zehnder interferometers aiming to optimize their biofunctionalization with regard to indirect immunochemical (competitive) detection of ochratoxin A. Sensing areas are examined after: modification with (3-aminopropyl)triethoxysilane, spotting of OTA-ovalbumin conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin, reaction with OTA-specific mouse monoclonal antibody followed by goat anti-mouse IgG secondary antibody. Component mass loadings of all proteins involved in immunodetection are determined from TOF-SIMS micro-analysis combined with ellipsometry of planar surfaces. These data show that partial desorption of surface-bound probe and blocking protein takes place upon primary immunoreaction to a degree that depends on probe concentration in spotting solution. Taking into account this desorption, apparent binding stoichiometry of both antibodies in immune complexes formed onto chip surface is determined more accurately than the respective evaluation based on real-time sensor response. In addition, mass loadings for probe and secondary antibody is observed to saturate for optimum probe concentrations. Also, principal component analysis of TOF-SIMS data could resolve both immunoreactions and biofunctionalization and discriminate surfaces prepared with optimum probe concentrations from those prepared using suboptimum ones.

Protein adsorption/desorption and antibody binding stoichiometry on silicon interferometric biosensors examined with TOF-SIMS

KAUST Repository

Gajos, Katarzyna; Budkowski, Andrzej; Petrou, Panagiota; Pagkali, Varvara; Awsiuk, Kamil; Rysz, Jakub; Bernasik, Andrzej; Misiakos, Konstantinos; Raptis, Ioannis; Kakabakos, Sotirios

2018-01-01

Time-of-flight secondary ion mass spectrometry has been employed to examine, with biomolecular discrimination, sensing arm areas (20 μm x 600 μm) of integrated onto silicon chips Mach-Zehnder interferometers aiming to optimize their biofunctionalization with regard to indirect immunochemical (competitive) detection of ochratoxin A. Sensing areas are examined after: modification with (3-aminopropyl)triethoxysilane, spotting of OTA-ovalbumin conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin, reaction with OTA-specific mouse monoclonal antibody followed by goat anti-mouse IgG secondary antibody. Component mass loadings of all proteins involved in immunodetection are determined from TOF-SIMS micro-analysis combined with ellipsometry of planar surfaces. These data show that partial desorption of surface-bound probe and blocking protein takes place upon primary immunoreaction to a degree that depends on probe concentration in spotting solution. Taking into account this desorption, apparent binding stoichiometry of both antibodies in immune complexes formed onto chip surface is determined more accurately than the respective evaluation based on real-time sensor response. In addition, mass loadings for probe and secondary antibody is observed to saturate for optimum probe concentrations. Also, principal component analysis of TOF-SIMS data could resolve both immunoreactions and biofunctionalization and discriminate surfaces prepared with optimum probe concentrations from those prepared using suboptimum ones.

Omalizumab: Clinical Use for the Management of Asthma

OpenAIRE

Thomson, Neil C.; Chaudhuri, Rekha

2012-01-01

Omalizumab, a humanized monoclonal antibody that binds circulating IgE antibody, is a treatment option for patients with moderate to severe allergic asthma whose asthma is poorly controlled with inhaled corticosteroids and inhaled long-acting β 2 agonist bronchodilators. This review considers the mechanism of action, pharmacokinetics, efficacy, safety and place in management of omalizumab in asthma and focuses particularly on key articles published over the last three years. Omalizumab reduce...

Triggers of IgE class switching and allergy development

DEFF Research Database (Denmark)

Poulsen, Lars K.; Hummelshoj, Lone

2007-01-01

type 2 (Th2) T cell subset are the actions of thymic stromal lymphopoietin (TSLP) on dendritic cells and the OX40 ligand on CD4+ T cells. In order for a B lymphocyte to switch to IgE production it needs two signals provided by a Th2 cell in the form of the cytokines interleukin (IL-) 4/IL-13...... the need for more knowledge on preventable causes of IgE- and allergy development....

Assignment of C1q-binding HLA antibodies as unacceptable HLA antigens avoids positive CDC-crossmatches prior to transplantation of deceased donor organs.

Science.gov (United States)

Juhl, David; Marget, Matthias; Hallensleben, Michael; Görg, Siegfried; Ziemann, Malte

2017-03-01

Soon, a virtual crossmatch shall replace the complement-dependent cytotoxicity (CDC) allocation crossmatch in the Eurotransplant region. To prevent positive CDC-crossmatches in the recipient centre, careful definition of unacceptable antigens is necessary. For highly sensitized patients, this is difficult by CDC alone. Assignment of all antibodies detected by sensitive assays, however, could prevent organ allocation. To assess the usefulness of the Luminex C1q-assay to prevent positive CDC-crossmatches, all CDC-crossmatches performed prior to deceased kidney transplantation in a 16-month-period were reviewed. Sera causing positive crossmatches were investigated by the C1q-assay. 31 out of 1432 crossmatches (2.2%) were positive. Sera involved in 26 positive crossmatches were available. C1q-binding donor-specific antibodies were detected in 19 sera (73.1%). The other sera were from recipients without any HLA antibodies detectable by CDC or common solid phase assays. Three patients had known Non-HLA antibodies causing positive CDC-results. Four crossmatches were only weak positive. Therefore, avoidance of donors with HLA antigens against whom C1q-binding antibodies were detected would have prevented all positive crossmatches due to HLA antibodies. Provided that all HLA specificities against which antibodies are detected by the Luminex C1q-assay are considered as unacceptable antigens, CDC-crossmatches prior to transplantation might safely be omitted in many patients. They should be maintained in highly immunized patients, however, for whom assignment of all C1q-positive antibodies as unacceptable antigens could lead to a significant delay or even prevention of transplantation. Copyright © 2017 Elsevier B.V. All rights reserved.

A monoclonal antibody against PDGF B-chain inhibits PDGF-induced DNA synthesis in C3H fibroblasts and prevents binding of PDGF to its receptor.