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Major Allergen (major + allergen)

Distribution by Scientific Domains

Medical Sciences	84%
Chemistry	13%

Distribution within Medical Sciences

Allergy & Clinical Immunology	85%
Immunology	8%
2 Other Subdomains	7%

Selected Abstracts

Latex allergy: diagnosis and management

DERMATOLOGIC THERAPY, Issue 4 2004
James S. Taylor
ABSTRACT:, Latex allergy is an IgE-mediated immediate hypersensitivity response to natural rubber latex (NRL) protein with a variety of clinical signs ranging from contact urticaria, angioedema, asthma, and anaphylaxis. Major allergens include dipped latex products such as gloves and balloons. In highest risk for NRL allergy are patients with spina bifida, but health care workers and others who wear latex gloves are also at risk. NRL allergic patients may also react to fruits/foods, especially banana, kiwi, and avocado. Diagnosis is made by a positive latex RAST and/or skin prick test or challenge test to NRL. Allergen avoidance and substitution and the use of latex-safe devices including synthetic gloves (vinyl, synthetic polyisoprene, neoprene, nitrile, block polymers, or polyurethane) are essential for the affected patient. Accommodation in the workplace may include the use of powder-free, low-allergen NRL gloves or synthetic gloves. These preventive measures have significantly reduced the prevalence of reported reactions to NRL. Hyposensitization is not yet feasible. [source]

Bet,v,1, the major birch pollen allergen, initiates sensitization to Api,g,1, the major allergen in celery: evidence at the T,cell level

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2003
Barbara Bohle
Abstract Due to IgE cross-reactivity, birch pollen-allergic individuals frequently develop type,I hypersensitivity reactions to celery tuber. We evaluated the T,cell response to the major allergen in celeriac, Api,g,1, and the cellular cross-reactivity with its homologous major allergen in birch pollen, Bet,v,1. Api,g,1-specific T,cell lines (TCL) and clones (TCC) were established from peripheralblood mononuclear cells of allergic patients. Epitope mapping of Api,g,1 with overlapping Api,g,1-derived peptides revealed one dominant T,cell-activating region, Api,g,1109,126. TCL and TCC generated with Api,g,1 cross-reacted with the birch pollen allergen and, although initially stimulated with the food allergen, cellular responses to Bet,v,1 were stronger than to Api,g,1. Epitopemapping with Bet,v,1-derived peptides revealed that T,cells specific for several distinct epitopes distributed over the complete Bet,v,1 molecule could be activated by Api,g,1. Bet,v,1109,126 was identified as the most important T,cell epitope for cross-reactivity with Api,g,1. This epitope shares 72% amino acid sequence similarity with the major T,cell-activating region of the food allergen, Api,g,1109,126. Our data provide evidence that humoral as well as cellular reactivity to the major celery allergen is predominantly based on cross-reactivity with the major birch pollen allergen. The activation of Bet,v,1-specific Th2 cells by Api,g,1, in particular outside the pollen season, may have consequences for birch pollen-allergic individuals. [source]

Lep d 2 polymorphisms in wild and cultured Lepidoglyphus destructor mites

FEBS JOURNAL, Issue 4 2003
Liselotte Kaiser
We have previously cloned, expressed and characterized two variants of the major allergen Lep d 2 from cultured Lepidoglyphus destructor mites. These variants, Lep d 2.0101 and Lep d 2.0201, differ at 13 amino acid positions. In this study we investigated Lep d 2 sequence diversity between wild and cultured mites. PCR, Southern blot and DNA sequence analysis revealed the presence of two different Lep d 2 genes, one with and one without an intron. In addition, two new variants of Lep d 2, Lep d 2.0102 and Lep d 2.0202, were found at different frequencies in wild and cultured mites. When we expressed the Lep d 2 variants and compared their IgE binding properties by ELISA inhibition, we found that Lep d 2.0102 was a more potent inhibitor than Lep d 2.0101, and to a lesser extent Lep d 2.0202 was more potent than Lep d 2.0201. Long-term cultures of peripheral blood mononuclear cells were used to assess the ability of the expressed Lep d 2 variants to induce cytokine release. Although cells from different individuals released different amounts of interferon-, and interleukin-5, no consistent cytokine release pattern could be linked to any specific Lep d 2 variant. In conclusion, we show that both cultured and wild Lepidoglyphus destructor mites contain the same pattern of polymorphism. Furthermore, this Lep d 2 sequence diversity seems not to have any significant impact on the allergens IgE binding or its ability to induce T cell cytokine release. [source]

State of the art and new horizons in the diagnosis and management of egg allergy

ALLERGY, Issue 3 2010
A. H. Benhamou
To cite this article: Benhamou AH, Caubet J-C, Eigenmann PA, Nowak-We,grzyn A, Marcos CP, Reche M, Urisu A. State of the art and new horizons in the diagnosis and management of egg allergy. Allergy 2010; 65: 283,289. Abstract Egg allergy is one of the most frequent food allergies in children below the age of three. Common symptoms of egg allergy involve frequently the skin as well as the gut and in more severe cases result in anaphylaxis. Non-IgE-mediated symptoms such as in eosinophilic diseases of the gut or egg-induced enterocolitis might also be observed. Sensitization to egg white proteins can be found in young children in absence of clinical symptoms. The diagnosis of egg allergy is based on the history, IgE tests as well as standardized food challenges. Ovomucoid is the major allergen of egg, and recent advances in technology have improved the diagnosis and follow-up of patients with egg allergy by using single allergens or allergens with modified allergenic properties. Today, the management of egg allergy is strict avoidance. However, oral tolerance induction protocols, in particular with egg proteins with reduced allergenic properties, are promising tools for inducing an increased level of tolerance in specific patients. [source]

Instability of the structure and allergenic protein content in Arizona cypress pollen

ALLERGY, Issue 12 2009
Y. Shahali
Background:, The allergenic characteristics of pollen and their levels of expression may vary depending on the plant species, the degree of maturation and the influence of environmental factors such as climate and atmospheric pollution. The objective of this survey was the comparison of the structure and allergenic protein content in Arizona cypress (Cupressus arizonica, CA) pollen collected just after microsporangia dehiscence and 2 weeks later in urban areas. Methods:, The morphology and structure of pollen were examined by scanning electron microscopy. Pollen protein content was quantitatively and qualitatively investigated by Bradford protein assay, SDS-PAGE and densitometric analysis respectively. Fifteen allergic subjects, according to their clinical history of seasonal rhino-conjunctivitis and bronchial asthma have been selected for skin prick testing and ImmunoCap using CA standard allergen and for immunoblotting using extracts of CA mature pollen collected from Tehran. Results:, After 2 weeks, numerous cracks and collapses appeared in pollen surfaces. Western blotting performed by using extracts of pollen collected from Tehran, revealed that sera-specific immunoglobulin E of all allergic subjects reacted to a 35 kDa protein. The presence of this new major allergen and the decrease of Cup a 1 provide reliable explications about the low efficiency of standard commercial allergens in the diagnosis of the CA pollen allergy in Tehran. Conclusion:, The instability of the pollen structure and protein content affects CA pollen allergenic properties. This study also suggests that to optimize CA standard allergen preparations, the eventual variability of pollen allergenic components have to be considered for each region. [source]

Molecular and immunological characterization of Asp f 34, a novel major cell wall allergen of Aspergillus fumigatus

ALLERGY, Issue 8 2009
A. G. Glaser
Background:, Although fungal spores have been recognized as triggers of respiratory allergy and asthma, only two allergenic fungal cell wall components have so far been described. Methods:, Eighty-one sequences derived from an Aspergillus fumigatus cDNA library encoding putative allergens were examined for the presence of cell wall components. A new allergen (Asp f 34) was evaluated by Western blots, enzyme-linked immunosorbent assay (ELISA), peripheral blood mononuclear cell (PBMC) proliferation assays, and skin prick test (SPT). Results:, The cDNA encoding Asp f 34 contained an open reading frame predicting a protein of 185 amino acids with a molecular weight of 19.38 kDa, showing sequence homology to phiA, an essential protein for the formation of conidia in the genus Aspergillus. The recombinant Asp f 34 was binding IgE from sensitized individuals in Western blots. An ELISA survey showed that 94% of the ABPA and 46% of the A. fumigatus -sensitized individuals tested had Asp f 34-specific serum IgE. Asp f 34 induced allergen-specific proliferation exclusively of PBMCs from patients sensitized to the allergen. Eight patients with anti-Asp f 34 serum IgE tested reacted positively in SPT, whereas four A. fumigatus -sensitized individuals without Asp f 34-specific IgE and eight healthy controls scored negatively. Conclusions:, A cell wall protein of the phialides of A. fumigatus was identified as a major allergen. Asp f 34 belongs to the Aspergillus -specific proteins of the phiA family and has relevant potential for a specific diagnosis of Aspergillus sensitization. [source]

EU Forum: The CREATE Project: development of certified reference materials for allergenic products and validation of methods for their quantification

ALLERGY, Issue 3 2008
R. Van Ree
Allergen extracts have been used for diagnosis and treatment of allergy for around 100 years. During the second half of 20th century, the notion increasingly gained foothold that accurate standardization of such extracts is of great importance for improvement of their quality. As a consequence, manufacturers have implemented extensive protocols for standardization and quality control. These protocols have overall IgE-binding potencies as their focus. Unfortunately, each company is using their own in-house reference materials and their own unique units to express potencies. This does not facilitate comparison of different products. During the last decades, most major allergens of relevant allergen sources have been identified and it has been established that effective immunotherapy requires certain minimum quantities of these allergens to be present in the administered maintenance dose. Therefore, the idea developed to introduce major allergens measurements into standardization protocols. Such protocols based on mass units of major allergen, quantify the active ingredients of the treatment and will at the same time allow comparison of competitor products. In 2001, an EU funded project, the CREATE project, was started to support introduction of major allergen based standardization. The aim of the project was to evaluate the use of recombinant allergens as reference materials and of ELISA assays for major allergen measurements. This paper gives an overview of the achievements of the CREATE project. [source]

Mala s 12 is a major allergen in patients with atopic eczema and has sequence similarities to the GMC oxidoreductase family,

ALLERGY, Issue 6 2007
A. Zargari
Background:, Atopic eczema (AE) is a chronic inflammatory skin disorder, characterized by impaired skin barrier and itch. The yeast Malassezia belongs to the normal human skin microflora and can induce IgE- and T-cell-mediated allergic reactions in AE patients. Previously, we have identified several IgE-binding components in Malassezia sympodialis extract. Methods:, Here, we report cloning, production and characterization of a M. sympodialis 67-kDa allergen. Results:, The sequence of the 67-kDa protein, termed Mala s 12, showed sequence similarity to the glucose,methanol,choline (GMC) oxidoreductase enzyme superfamily and was expressed as a recombinant protein in Escherichia coli. The purified protein bound flavin adenine dinucleotide with 1:1 stoichiometry per monomer of protein. The protein-bound flavin showed an extinction coefficient at 451 nm of 11.3 mM,1cm,1. The recombinant 67-kDa protein did not show any enzymatic activity when tested as oxidase or dehydrogenase using choline, glucose, myo-inositol, methanol, ethanol, 1-pentanol, benzyl alcohol, 2-phenylethanol, cholesterol or lauryl alcohol as possible substrates. Recombinant Mala s 12 was recognized by serum IgE from 13 of 21 (62%) M. sympodialis -sensitized AE patients indicating that the 67-kDa component is a major allergen. Conclusions:, The data show that Mala s 12 has sequence similarity to the GMC oxidoreductase family and is a major allergen in AE patients. [source]

Structure of the major carrot allergen Dau,c,1

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2009
-Housley, Zora Markovi
Dau,c,1 is a major allergen of carrot (Daucus carota) which displays IgE cross-reactivity with the homologous major birch-pollen allergen Bet,v,1. The crystal structure of Dau,c,1 has been determined to a resolution of 2.7,Å, revealing tight dimers. The structure of Dau,c,1 is similar to those of the major allergens from celery, Api,g,1, and birch pollen, Bet,v,1. Electron density has been observed in the hydrophobic cavity of each monomer and has been modelled with polyethylene glycol oligomers of varying length. Comparison of the surface topology and physicochemical properties of Dau,c,1 and Bet,v,1 revealed that they may have some, but not all, epitopes in common. This is in agreement with the observation that the majority of carrot-allergic patients have Bet,v,1 cross-reactive IgE antibodies, whereas others have Dau,c,1-specific IgE antibodies which do not recognize Bet,v,1. [source]

Crystallization and preliminary X-ray analysis of Der f 2, a potent allergen derived from the house dust mite (Dermatophagoides farinae)

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003
Dana Roeber
Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophagoides sp.) are ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis and asthma associated with allergic reactions to these arthropods are frequently caused by relatively small (125,129 amino acids) mite proteins of unknown biological function. Der,f,2, a major allergen from the mite D.,farinae, has been recombinantly expressed, characterized and crystallized. The crystals belong to the tetragonal space group I4122, with unit-cell parameters a = b = 95.2, c = 103.3,Å. An essentially complete (97.2%) data set has been collected to 2.4,Å at a synchrotron source. Attempts to solve the crystal structure of Der,f,2 by molecular replacement using the NMR coordinates for either Der,f,2 or Der,p,2 (the homologous protein from D.,pteronyssinus) failed, but preliminary searches using the crystalline Der p 2 atomic coordinates appear to be promising. [source]

Production of native and modified recombinant Der p 1 molecules in tobacco plants

CLINICAL & EXPERIMENTAL ALLERGY, Issue 5 2009
D. Burtin
Summary Background As a complex molecule requiring post-translational processing, it has been difficult to produce the Der p 1 major allergen from the Dermatophagoides pteronyssinus house dust mite in a recombinant form. Objective Here, we tested whether transgenic tobacco plants are suitable to express Der p 1, either as a wild-type molecule or as variants lacking N -glycosylation sites (Gly,) and/or cysteine protease activity (Enz,). Methods Using Agrobacterium tumefaciens -based transformation, pro Der p 1 molecules bearing mutations within either the N -glycosylation sites (N34Q, N150Q) and/or the cysteine protease-active site (C132V) were expressed in tobacco plants. After purification by ion exchange chromatography, allergens were characterized using immunoblotting, circular dichroism (CD), as well as basophil and T lymphocyte stimulation assays. Results Four forms of recombinant Der p 1 (i.e. wild-type Gly+/Enz+, as well as Gly,/Enz+, Gly+/Enz, or Gly,/Enz, variants) were successfully expressed in tobacco leaves as pro Der p 1 molecules. Spontaneous cleavage of the pro-peptide was observed in tobacco leaf extracts for all forms of recombinant Der p 1 (r Der p 1). CD confirmed that all r Der p 1 molecules, with the exception of the Gly,/Enz, variant, exhibited secondary structures comparable to the natural protein. A cysteine protease activity was associated only with the Gly+/Enz+ form. All these molecules exhibit a profile similar to natural Der p 1 with respect to IgE immunoreactivity, basophil activation and T cell recognition. Conclusion A tobacco plant expression system allows the production of various forms of mature Der p 1, which could be used for diagnostic or immunotherapeutic purposes. [source]

Kiwifruit allergy: actinidin is not a major allergen in the United Kingdom

CLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2007
J. S. A. Lucas
Summary Background Actinidin has previously been reported as the major allergen in kiwifruit. Objectives To investigate the relevance of actinidin in a well-characterized population of UK patients with kiwifruit allergy. Methods To identify the allergens in kiwifruit, using Western blots, we examined the IgE-binding patterns of 76 patients with a history of kiwifruit allergy, 23 of who had had a positive double-blind, placebo-controlled food challenge. In addition, IgE binding to purified native actinidin was studied in 30 patients, and to acidic and basic isoforms of recombinant actinidin in five patients. Inhibition of IgE binding to kiwifruit protein extract by purified native actinidin was investigated by both inhibition immunoblots and inhibition ELISAs using pooled sera. Results Twelve protein bands in kiwifruit protein extract were bound by IgE. A protein band with a molecular weight of 38 kDa was the major allergen recognized by 59% of the population. IgE did not bind to actinidin in the kiwifruit protein extract, or to purified native or recombinant forms of actinidin during Western blotting. Pooled sera bound to kiwifruit protein extract but not purified actinidin on ELISA, and pre-incubating sera with actinidin did not inhibit IgE binding to kiwifruit protein extract on immunoblot or ELISA. Conclusion A novel 38 kDa protein, not actinidin, is the major allergen in this large study population. Identification of major allergens in one patient group is therefore not necessarily reproducible in another; therefore, major allergens should not be defined until there is a sufficient body of data from diverse geographical and cultural populations. [source]

Hypoallergenic mutants of Ole e 1, the major olive pollen allergen, as candidates for allergy vaccines

CLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2007
E. G. Marazuela
Summary Background The C-terminal region of Ole e 1, a major allergen from olive pollen, is a dominant IgE-reactive site and offers a target for site-directed mutagenesis to produce variants with reduced IgE-binding capability. Objective To evaluate in vitro and in vivo the immunogenic properties of three engineered derivatives of Ole e 1. Methods One point (Y141A) and two deletion (135,10 and 140,5) mutants were generated by site-directed mutagenesis of Ole e 1-specific cDNA and produced in Pichia pastoris. Ole e 1 mutants were analysed for IgE reactivity by ELISA using sera from olive pollen-allergic patients. Their allergenicity was also investigated in both a mouse model of allergic sensitization and in basophil activation assays. IgG1 response was assayed by immunoblotting and competitive ELISA. T cell reactivity was evaluated by proliferation assays and cytokine production in splenocyte cultures. Results The 135,10 mutant showed the strongest reduction in the IgE-binding capability of sera from olive pollen-allergic patients. Rat basophil leukaemia assays identified the deletion mutant 135,10 as the variant with the lowest ,-hexosaminidase-releasing capacity. Furthermore, the same 135,10 mutant induced the lowest IgE levels in a BALB/c mouse model of sensitization. All Ole e 1 mutants retained their allergen-specific T cell reactivity. Immunization of mice with the mutants induced IgG1 antibodies, which cross-reacted with Ole e 1 and Ole e 1-like allergens from ash, lilac and privet pollens. The ability of the human IgE to block the binding of anti-Ole e 1 mutant-specific mouse IgG1 antibodies to natural Ole e 1 demonstrated that Ole e 1 mutants are able to induce in vivo antibodies reactive to the natural allergen. Conclusion The 135,10 mutant with reduced allergenicity, intact T cell reactivity and capacity to induce blocking antibodies could provide a suitable candidate vaccine for efficient and safer therapy of olive pollen allergy. [source]

Characterization of the T cell response to the major hazelnut allergen, Cor a 1.04: evidence for a relevant T cell epitope not cross-reactive with homologous pollen allergens

CLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2005
B. Bohle
Summary Background IgE antibodies specific for the major birch-pollen allergen, Bet v 1, cross-react with homologous allergens in particular foods, e.g. apples, carrots and hazelnuts. In a high number of tree pollen-allergic individuals, this cross-reactivity causes clinical symptoms, commonly known as the ,birch-fruit-syndrome'. Objective To characterize the T cell response to the Bet v 1-related major allergen in hazelnuts, Cor a 1.04, and its cellular cross-reactivity with Bet v 1 and the homologous hazel pollen allergen, Cor a 1. Methods Using recombinant Cor a 1.04, T cell lines (TCL) and T cell clones (TCC) were established from peripheral blood mononuclear cells of tree pollen-allergic patients with associated food allergy. T cell epitopes were determined using overlapping synthetic peptides in Cor a 1.04-reactive TCL and TCC. In parallel, reactivity to Bet v 1 and Cor a 1 was tested. Results In total, 20 distinct T cell epitopes on the hazelnut allergen were identified. Several Cor a 1.04-specific TCL and TCC reacted with pollen allergens albeit less pronounced than with the hazelnut allergen. Several Cor a 1.04-specific TCC did not react with pollen allergens. Interestingly, these clones were found to react with the Bet v 1-related major allergen in carrots, Dau c 1. The cellular cross-reactivity between both food allergens could be associated with the most frequently recognized T cell epitope of Cor a 1.04, Cor a 1.04142,153. Conclusions The major hazelnut allergen cross-reacts with the major allergens of birch and hazel pollen but apparently contains a relevant T cell epitope not shared with pollen allergens. Our finding may have important implications for the specific immunotherapy of tree pollen-allergic patients suffering from concomitant hazelnut allergy. [source]

Transgenic mice expressing the T cell antigen receptor specific for an immunodominant epitope of a major allergen of house dust mite develop an asthmatic phenotype on exposure of the airways to allergen

CLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2005
E. R. Jarman
Summary Background Current studies on mechanisms underlying allergen-induced pulmonary inflammation and asthma are hampered by the lack of appropriate physiological in vivo models that reflect the natural route of allergen exposure and sensitization. Objective To generate and phenotype a transgenic mouse strain expressing the T cell receptor (TCR) specific for an immunodominant domain of the major inhalant allergen Dermatophagoides pteronyssinus species of house dust mite (Der p 1), for the development of an in vivo model of allergic asthma. Methods Der p 1 transgenic mice were generated using TCR-,, derived from a CD4+ T cell hybridoma reactive with Der p 1 residues p 110,131. The frequency and functional activity of peripheral T cells were determined and parameters of airway inflammation assessed following allergen challenge of the airways with Der p 1. Results CD4+ T cells are functionally active, exhibiting dose-dependent proliferation and IL-4 production on primary stimulation with Der p 1 or Der p 1, p 110,131 in vitro, independent of in vivo antigen priming. On sensitization of the airways with allergen, in the absence of systemic priming or the application of adjuvants, the TCR transgenic mice develop airway inflammation characterized by a marked lymphocytic and eosinophilic infiltrate with goblet cell hyperplasia and enhanced mucin production. Conclusion The Der p 1 TCR transgenic mice provide a model for investigating the pathophysiological mechanisms of pulmonary inflammation following sensitization by exposure of the airways to allergen and for investigating the mode of action and efficacy of novel immunotherapeutics. [source]

Pho d 2, a major allergen from date palm pollen, is a profilin: cloning, sequencing, and immunoglobulin E cross-reactivity with other profilins

CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2005
J. A. Asturias
Summary Background Up to now, some date palm pollen (DPP) allergens have been described but very few data are available about their molecular nature. The aim of this study was to identify and characterize Pho d 2, a major allergen from this pollen. Methods Sera from 25 patients allergic to DPP were analysed by immunoblotting. Purification of DPP profilin was performed by poly- l -proline affinity chromatography. Profilin-encoding cDNA from DPP was cloned by using a RT-PCR strategy and recombinant allergen was expressed as a non-fusion protein in Escherichia coli. Natural and recombinant Pho d 2 were investigated by means of enzyme allergosorbent test to compare the immunologic properties of both allergens and to analyse cross-reactivity with other profilins. Results A 14.4 kDa protein was identified as a major allergen in DPP extract. Purification, cloning, heterologous expression, and inhibition experiments identified it as profilin (Pho d 2). Pho d 2 comprises 131 amino acids and has high sequence identity with other allergenic food and pollen profilins. The prevalence of specific IgE antibody reactivity to natural Pho d 2 by ELISA was 56% and 64% by skin prick test (SPT). Pho d 2 is an important allergen as it is responsible for more than 70% of the IgE reactivity to the pollen extract. IgE directed against Pho d 2 showed a strong cross-reactivity with other profilins such as those from olive tree and grass pollens. Conclusion Pho d 2, a 14.4 kDa protein identified as profilin, is a major and relevant allergen in DPP, as confirmed by SPT and thereby may elicit clinical symptoms in sensitized patients. [source]

Analysis of sequential immunoglobulin E-binding epitope of Japanese cedar pollen allergen (Cry j 2) in humans, monkeys and mice

CLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2003
Y. Tamura
Summary Background Japanese cedar (Cryptomeria japonica; CJ) pollinosis has been reported to occur naturally in Japanese monkeys (Macaca fuscata) as well as in humans. Most human patients and monkeys with pollinosis have specific IgE for Cry j 2, a major allergen of CJ pollen. Objective The main purpose of this study was to identify IgE B cell epitopes of Cry j 2 using a synthetic peptide in humans, monkeys and mice. Methods We synthesized 38 overlapping peptides that span the entire length of Cry j 2. We examined the B cell epitopes of Cry j 2 that are recognized by IgE in the sera of human patients and monkeys with pollinosis and immunized mice using synthetic peptides of Cry j 2. We also examined the reaction of Cry j 2-specific mouse monoclonal IgG antibodies to the peptides. Furthermore, we conducted a histamine release assay with leucocytes from a pollinosis patient using human serum albumin (HSA) conjugated with the peptides as a B cell epitope. Results We found that 16 of the 20 pollinosis patients who had specific IgE to Cry j 2 also exhibited IgE reaction with some Cry j 2 peptides. Of these 16 patients, 10 exhibited IgE reaction with Cry j 2 peptide no. 13 (121GQCKWVNGREICNDRDRPTA140). Five of the seven monkeys with CJ pollinosis exhibited a reaction with peptide no. 13. Furthermore, IgE in mice immunized with Cry j 2 and two mouse monoclonal IgG antibodies reacted with peptide no. 13. Peptide no. 13-conjugated HSA showed the release of histamine from basophils. Furthermore, to determine the minimum epitope in peptide no. 13, we conducted an enzyme-linked immunosorbent assay inhibition test. The core of the epitope in humans, monkeys and mice was 124KWVNGREI131. Conclusion We found that 124KWVNGREI131 is an important B cell epitope recognized by IgE in humans, monkeys and mice. [source]

What is the role of the hevein-like domain of fruit class I chitinases in their allergenic capacity?

CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2002
A. Dìaz-Perales
Background Class I chitinases are the major panallergens in fruits associated with the latex,fruit syndrome. These enzymes contain an N-terminal hevein-like domain homologous to latex hevein, and a larger catalytic domain. The role of these domains in their allergenic capacity is still controversial. Objective We sought to evaluate the role of both domains of class I chitinases in their IgE-binding properties, using Cas s 5, the major allergen from chestnut, as a model. Methods Recombinant Cas s 5 and its deleted form, lacking the hevein-like domain, designated rCat, were expressed in Pichia pastoris using the pPIC 9 vector. Both recombinant products were purified from the supernatants of transformed yeast cultures by gel-filtration and cation-exchange chromatography. The isolated proteins were characterized by N-terminal sequencing, enzymatic activity and N-glycosylation tests, anti-chitinase and specific IgE immunodetection. Immunoblot, RAST and CAP inhibition assays were also performed. Results Both purified rCas s 5 and rCat showed the expected N-terminal amino acid sequences and an enzymatic activity similar to that of their natural counterparts isolated from chestnut seeds, and were strongly recognized by anti-chitinase antibodies. In contrast, only rCas s 5, but not rCat, bound specific IgE from sera of patients suffering from the latex,fruit syndrome, and fully inhibited IgE-binding to natural Cas s 5 in immunoblot inhibition assays. Latex hevein also exerted a strong immunoblot inhibition of IgE-binding to chestnut Cas s 5. RAST and CAP inhibition using whole chestnut extract on the solid phase, rendered inhibition levels around 70,90% for rCas s 5 and 60% for rCat, in contrast to the immunoblotting results. Conclusions Recombinant Cas s 5 behaves like natural Cas s 5 in IgE-binding assays in vitro. The hevein-like domain of allergenic class I chitinases seems to include all their main IgE-binding epitopes when tested by immunodetection and immunoblot inhibition experiments. RAST and CAP inhibition assays, on the contrary, suggest that relevant epitopes are also harboured in the catalytic domain of these allergens. [source]

Identification and characterization of a group 2 conifer pollen allergen from Chamaecyparis obtusa, a homologue of Cry j 2 from Cryptomeria japonica

CLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2000
Yasueda
Background Not only Cryptomeria japonica (Japanese cedar) pollen but also that of Chamaecyparis obtusa (Japanese cypress) induces the allergic symptoms of Japanese cedar pollinosis. However, allergens from C. obtusa pollen have not been as well characterized as those from C. japonica pollen. Objective We sought to identify and characterize a homologue of the second major allergen of C. japonica pollen, Cry j 2, from the pollen of C. obtusa. Methods An allergen homologous to Cry j 2 was identified in C. obtusa pollen extract by immunoblot analysis, probed with anti-Cry j 2 monoclonal antibodies and purified by a series of column chromatographic steps. Results The allergen isolated from the extract showed a slightly diffuse band of 45 kDa and closely spaced double-bands of 42 and 45 kDa on SDS-PAGE, under reducing and non-reducing conditions, respectively; the bands were approximately 5,7 kDa larger than those of Cry j 2. In 24 of 30 residues, the N-terminal amino acid sequence of the allergen was identical with corresponding sequence in Cry j 2. Most patients with pollinosis who were IgE antibody-positive to Cry j 2 were shown to be IgE antibody-positive to this allergen, and the IgE antibody levels to both allergens were highly correlated. Conclusion The results indicate that the allergen isolated from C. obtusa pollen in this study is a homologue of Cry j 2. The allergen was designated as Cha o 2 according to the WHO/IUIS Allergen Nomenclature Subcommittee recommendation. [source]

Effect of proteolytic activity of Epicoccum purpurascens major allergen, Epi p 1 in allergic inflammation

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2008
N. Kukreja
Summary Enzymes play an important role in inducing airway inflammation, but knowledge is limited to few proteins. This study was carried out to assess the role of Epi p 1, a serine protease of Epicoccum purpurascens, in inducing allergy and inflammation in a murine model. Balb/c mice were sensitized with Epi p 1 active protease (EAP) or Epicoccum extract. Subsequently, Epi p 1 sensitized mice were boosted on day 14 with EAP or inactivated protease (EIAP). Three intranasal challenges were given and mice were killed to obtain blood, bronchoalveolar lavage fluid (BALF), spleen and lung tissues. Cellular airways infiltration, immunoglobulin E (Ig)E titres and cytokine levels in BALF and splenocyte culture supernatant were compared. Mice immunized with EAP had higher Epi p 1-specific serum IgE and IgG1 than EIAP immunized mice (P < 0·01). There was a twofold difference in the number of eosinophils in BALF of EAP mice and EIAP mice (P < 0·01). A similar trend was recorded for eosinophil peroxidase activity (P < 0·05), indicating the role of proteolytic activity in inducing inflammation. Further, lung histology revealed increased leucocyte infiltration and airway narrowing, with higher inflammation scores in the EAP group than in the EIAP group. The lungs of EAP mice showed increased mucus and goblet cell metaplasia. Interleukin (IL)-4 and IL-5 levels were higher in BALF and splenocyte culture supernatant of EAP mice than in EIAP mice (P < 0·05), indicating a T helper 2 response. Proteolytic activity of Epi p 1 plays an important role in inducing allergic inflammation. The enzymatically inactive form may be investigated for immunotherapy. [source]

Seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients with Helicobacter pylori infection: histological and laboratory findings and clinical significance

CLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2006
C. Toro
Abstract Previous studies have demonstrated a high prevalence of seropositivity to the Ani s 1 protein in dyspeptic patients with Helicobacter pylori infection, but it is not known whether this represents episodes of anisakiasis misdiagnosis or previous exposure to the parasite without clinical relevance. To investigate the clinical significance of seropositivity to the Ani s 1 protein, a cohort study was performed with 87 consecutive dyspeptic patients who were treated for H. pylori infection. Fourteen (16.5%) patients were seropositive for the Ani s 1 protein, which was associated with the consumption of uncooked fish (p 0.0002). There were no differences in histological findings between subjects seropositive or seronegative for Ani s 1, but seropositive patients had increased eosinophil and basophil leukocyte counts (p < 0.05). Anti-Ani s 1 IgE was associated with a lack of improvement in the group of patients with non-ulcer dyspepsia after successful eradication of H. pylori (p 0.016). Thus, in at least a subset of patients with H. pylori infection, seropositivity to Ani s 1 could have clinical relevance. In addition, these data highlight that only anisakiasis associated with severe allergic or gastric symptoms is currently being diagnosed. [source]

Par j 1 and Par j 2, the two major allergens in Parietaria judaica, bind preferentially to monoacylated negative lipids

FEBS JOURNAL, Issue 6 2009
Roberto González-Rioja
Par j 1 and Par j 2 proteins are the two major allergens in Parietaria judaica pollen, one of the main causes of allergic diseases in the Mediterranean area. Each of them contains eight cysteine residues organized in a pattern identical to that found in plant nonspecific lipid transfer proteins. The 139- and 102-residue recombinant allergens, corresponding respectively to Par j 1 and Par j 2, refold properly to fully functional forms, whose immunological properties resemble those of the molecules purified from the natural source. Molecular modeling shows that, despite the lack of extensive primary structure homology with nonspecific lipid transfer proteins, both allergens contain a hydrophobic cavity suited to accommodate a lipid ligand. In the present study, we present novel evidence for the formation of complexes of these natural and recombinant proteins from Parietaria pollen with lipidic molecules. The dissociation constant of oleyl-lyso-phosphatidylcholine is 9.1 ± 1.2 ,m for recombinant Par j 1, whereas pyrenedodecanoic acid shows a much higher affinity, with a dissociation constant of approximately 1 ,m for both recombinant proteins, as well as for the natural mixture. Lipid binding does not alter the secondary structure content of the protein but is very efficient in protecting disulfide bonds from reduction by dithiothreitol. We show that Par j 1 and Par j 2 not only bind lipids from micellar dispersions, but also are able to extract and transfer negative phospholipids from bilayers. [source]

The N-glycans of yellow jacket venom hyaluronidases and the protein sequence of its major isoform in Vespula vulgaris

FEBS JOURNAL, Issue 20 2005
Daniel Kolarich
Hyaluronidase (E.C. 3.2.1.35), one of the three major allergens of yellow jacket venom, is a glycoprotein of 45 kDa that is largely responsible for the cross-reactivity of wasp and bee venoms with sera of allergic patients. The asparagine-linked carbohydrate often appears to constitute the common IgE-binding determinant. Using a combination of MALDI MS and HPLC of 2-aminopyridine-labelled glycans, we found core-difucosylated paucimannosidic glycans to be the major species in the 43,45 kDa band of Vespula vulgaris and also in the corresponding bands of venoms from five other wasp species (V. germanica, V. maculifrons, V. pensylvanica, V. flavopilosa and V. squamosa). Concomitant peptide mapping of the V. vulgaris 43 kDa band identified the known hyaluronidase, Ves v 2 (SwissProt P49370), but only as a minor component. De novo sequencing by tandem MS revealed the predominating peptides to resemble a different, yet homologous, sequence. cDNA cloning retrieved a sequence with 58 and 59% homology to the previously known isoform and to the Dolichovespula maculata and Polistes annularis hyaluronidases. Close homologues of this new, putative hyaluronidase b (Ves v 2b) were also the major isoform in the other wasp venoms. [source]

Identification of spore allergens from the indoor mould Aspergillus versicolor

ALLERGY, Issue 4 2008
D. Benndorf
Background:, Indoor mould growth and dampness are associated with respiratory health effects and allergies and several studies demonstrated that mainly Aspergillus versicolor and Penicillium expansum are responsible for indoor mould exposure. In contrast, commercialized test systems to diagnose allergic reactions to this mould species are not available. In this study, allergenic proteins from spores of the indoor relevant species A. versicolor and P. expansum should get detected and identified. Methods:, We used two-dimensional (2D)-gel electrophoresis of spore proteins and immunoblotting with sera from patients participating in an epidemiologic study about indoor exposure of moulds and their influence on the development of allergies (ESTERSPEGA). Sera were screened for IgE antibodies specific for proteins from A. versicolor, A. fumigatus and P. expansum in one-dimensional blots and in 2D immunoblots. From the 2D gels, the corresponding spots were picked and identified by mass spectrometry. Results:, More than 20 allergens from A. versicolor were identified; in particular, seven major allergens were selected, which were detected by more than 90% of the positive sera. The most abundant allergen was glyceraldehyde-3-phosphate dehydrogenase, followed by an unnamed protein, which displays a high homology to sobitol/xylose reductase. The other allergens were identified as catalase A, hypothetical protein AN6918.2, enolase, hypothetical protein AN0297.2 and a protein with homology to a fungal malate dehydrogenase. Conclusions:, The results indicate an important role of spore proteins from A. versicolor for sensitization against indoor moulds and identification of the major allergens might enable species-specific diagnosis of allergic reactions. [source]

EU Forum: The CREATE Project: development of certified reference materials for allergenic products and validation of methods for their quantification

Natural rubber latex and chestnut allergy: cross-reactivity or co-sensitization?

ALLERGY, Issue 11 2007
M. Raulf-Heimsoth
Background:, Chestnut and natural rubber latex (NRL) allergy are often associated in the latex-fruit syndrome. Aim of the study:, To establish whether the concurrent NRL and chestnut IgE antibody reactivity are the results of co-sensitization or cross-reactivity. Methods:, Sera from 19 patients with chestnut- and NRL-specific IgE were selected and tested for reactivity with recombinant (r) latex allergens. Cross-reactivity was explored by IgE-inhibition experiments using chestnut or NRL allergens as solid phase on ImmunoCAP. Results:, IgE-antibodies were detected to rHev b 6.01 (prohevein) in 58% of the sera, to rHev b 5 in 32%, to rHev b 12 in four of 13 sera, to rHev b 7.02 and rHev b 11 in four, and to rHev b 1 in two of 19 sera. rHev b 8-IgE antibodies were found in nine sera (47%), whereas six displayed mono-sensitization to rHev b 8 with regard to our test panel. Three of 16 sera showed IgE to cross-reactive carbohydrate determinants. In most sera recognizing rHev b 5 and/or rHev b 6.01 as major allergens the IgE-reactivity to NRL remained unaffected by chestnut extract and chestnut-IgE remained unaffected by NRL extract. Conversely, in sera with rHev b 8 as dominant allergen IgE-binding to NRL was nearly completely inhibited by chestnut and vice versa. IgE-binding to rHev b 8 was abolished by chestnut extract. Conclusions:, Although patients have concomitant IgE antibody reactivity to chestnut and NRL, cross-reactivity could be demonstrated mainly in those patients with IgE to Hev b 8 (profilin) from NRL. [source]

Genetic differences in omega-gliadins involved in two different immediate food hypersensitivities to wheat

ALLERGY, Issue 8 2007
M. Laurière
Background:, Anti-gliadin IgE are expressed in patients with food allergy associated to skin immediate hypersensitivity to hydrolyzed wheat proteins (IHHWP). It is not known if they react with ,5-gliadins, the major allergens in wheat dependant exercise-induced food anaphylaxis (WDEIA), encoded on wheat chromosomes 1B. Methods:, Unmodified gliadins from 14 wheat varieties expressing most of the 1B ,-gliadin alleles, were immunoprobed after SDS-PAGE and blotting, with four sera from patients with IHHWP, and two with WDEIA. Gliadins reacting with IgE were visualized using chemiluminescence and identified according to their mobility and typical SDS-PAGE pattern. The resulting signal was also measured to compare their IgE reactivity. Results:, IHHWP and WDEIA sera exhibited distinct patterns of reactivity. IgE of patients with IHHWP reacted mainly with all ,-gliadins alleles and one ,-gliadin encoded respectively on chromosomes 1D and 1B, but not with any ,5-gliadins alleles as for WDEIA. A few other reactive alleles of ,-gliadins were encoded on chromosomes 1A. Unassigned additional bands of the whole gliadin pattern were also reactive. The four patients with IHHWP exhibited almost the same pattern of reactivity. Main differences concerned band reactivity which modulated the overall reactivity of each wheat variety. Conclusions:, The IgE epitopes involved in IHHWP and WDEIA are different. This suggests that the protein state and the route of exposure to very similar gluten structures, probably orientate the pattern of epitope reactivity and the wheat food allergy manifestations. [source]

Suspension-cultured BY-2 tobacco cells produce and mature immunologically active house dust mite allergens

PLANT BIOTECHNOLOGY JOURNAL, Issue 1 2007
David Lienard
Summary The replacement of crude allergen extracts by selected allergens currently represents a major goal for the improvement of allergy diagnosis and immunotherapy. Indeed, the development of molecularly defined vaccines would facilitate both standardization and enhance batch-to-batch reproducibility as well as treatment specificity. In this study, we have investigated the potential of tobacco plant cells to produce biologically active forms of the two major allergens from the house dust mite. A detailed characterization of these plant-made allergens has shown similar proteolytic maturation and folding as well as comparable immunoreactivity to their natural counterparts. Altogether, our results exemplify that suspension-cultured BY-2 tobacco cells represent a low cost and environmentally safe expression system suitable to produce recombinant allergens from Dermatophagoides pteronyssinus under a form appropriate for diagnostic and therapeutic purposes. [source]

Structure of the major carrot allergen Dau,c,1

Characterization of the major allergens of Pachycondyla chinensis in ant sting anaphylaxis patients

CLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2009
E. K. Lee
Summary Background The ant species Pachycondyla chinensis, which has spread from Far Eastern Asia to New Zealand and North America, induces anaphylactic reactions in human with its sting. However, the major allergens of P. chinensis have not yet been characterized. Methods We selected seven patients with histories of anaphylaxis induced by P. chinensis. Two-dimensional electrophoresis (2-DE) was used to identify the major allergens. We subsequently performed Western blots for P. chinensis -specific IgEs, N-terminal amino acid sequencing, ESI-MS/MS, and RT-PCR using primers based on the N-terminal sequence. Results Six of the anaphylactic subjects had an IgE specific to a 23 kDa allergen of P. chinensis. Two candidates for major allergens, 23 kDa (pI 8.7) and 25 kDa (pI 6.2), were revealed by 2-DE using P. chinensis -specific IgE immunoblotting. In N-terminal sequencing and ESI-MS/MS analysis, 23 kDa (pI 8.7) and 25 kDa (pI 6.2) allergens, belonging to the protein families of antigen 5, were identified and share marked amino acid sequence similarity. The 23 kDa allergen is 206 amino acids in length and homology searches showed 54.0% and 50.0% homology with Sol i 3 and Ves v 5, respectively. Conclusion The major allergens of P. chinensis are 23 kDa (pI 8.7) and 25 kDa (pI 6.2) proteins that belong to the antigen 5 family of proteins. [source]