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Based on two clinical observations of adverse reactions during exercise with latex sport bands, we aimed to assess the possible risk for allergic patients posed by this equipment by investigating allergen content and IgE binding potential. Protein extracts of three different latex sport bands were characterized with sera of latex allergic patients. The IgE recognition profile of the allergic patients was identified by component resolved diagnosis and the allergen composition of the extracts was characterized by inhibition assays with the recombinant latex allergens Hev b 1, 3, 5, 6.02, and 8. The sera showed pronounced IgE binding to all three blotted extracts, however with diverse patterns. Inhibition assays revealed the presence of Hev b 1, 3, 5, and 8 in latex sport band extracts. The clinical relevance of contained allergens was demonstrated by strong skin reactions when testing with latex sport bands. From our results we conclude that latex sport bands contain clinically relevant allergens and may cause latex allergic individuals to experience allergic symptoms, potentially amplified by exercise-induced mechanisms. Even though latex is labeled on products, it is important that patients as well as athletic trainers and physical therapists recognize the risk of adverse reactions with these bands.

Background: Engineered hypoallergens are currently being investigated for specific immunotherapy of allergic diseases in preclinical and clinical studies. Naturally occurring hypoallergens have by and large not been considered as a source of vaccine candidates., Objective: Evaluation of the antibody response in atopic individuals induced by birch pollen containing isoforms of the major birch pollen allergen Bet v 1., Methods: Isoform-specific antibody isotype responses for Bet v 1.0101, Bet v 1.0401, and Bet v 1.1001 were determined for 35 sera of individuals with birch pollen allergy. Isoform structures were compared and related to IgE-binding inhibitory capacities and induction of mediator release in human Fcvarepsilon receptor transformed rat basophilic leukemia cells., Results: Bet v 1.0101 induced a predominant IgE response, whereas the significant highest levels of IgG(4) antibodies were directed against Bet v 1.0401. Bet v 1.1001 induced only a minimal antibody response. Structural comparisons revealed that most of the amino acid differences between the isoforms were located on the protein surfaces. IgE induced by Bet v 1.0101 only partly cross-reacted with the 2 other isoforms and bound to them with notably lower affinity. Bet v 1.0401 and Bet v 1.1001 also were poor inducers of mediator release., Conclusion: Bet v 1 isoforms possess highly variant immunogenic and allergenic properties. Bet v 1.0101 acts as the sensitizing agent, whereas Bet v 1.0401 and Bet v 1.1001 can induce only a minimal IgE response.

A role of IgE antibodies in cancer surveillance has been implicated for a long time. Studies dealing with IgE antibodies directly targeted to tumor antigens have shown marked anticancer effects mediated by this antibody class. Thus, the basic function of IgE antibodies may be to control tumor growth. Thus far, cancer-specific IgE has only been applied passively. Consequently, the aim of this study was to establish an active vaccination protocol to induce tumor antigen-specific IgE antibodies, and to evaluate functional properties. We previously generated epitope mimics, so-called mimotopes, for the epitope recognized by the anti-HER-2 antibody trastuzumab. Upon i.p. immunizations, IgG antibodies with trastuzumab-like properties could be elicited. In the present study, we immunized BALB/c mice via the oral route with these trastuzumab mimotopes, under simultaneous neutralization and suppression of gastric acid. As shown in preceding experiments, this feeding regimen effectively induces Th2 immune responses. Oral immunizations with trastuzumab mimotopes under hypoacidic conditions indeed resulted in the formation of IgE antibodies towards the HER-2 antigen. Moreover, anti-HER-2 IgE-sensitized effector cells mediated SK-BR-3 target cell lysis in an antibody-dependent cytotoxicity assay. We conclude that directed and epitope-specific induction of IgE against tumor antigens is feasible with an oral mimotope vaccination regimen, and that these antibodies mediate anticancer effects.

In type I allergy, the cross-linking of membrane IgE on B lymphocytes and of cytophilic IgE on effector cells by their respective allergens are key events. For cross-linking two IgE molecules, allergens need at least two epitopes. On large molecules, these could be different epitopes in a multivalent, or identical epitopes in a symmetrical, fashion. However, the availability of epitopes may be limited on small allergens such as Bet v 1, the major birch pollen allergen. The present work analyzes whether dimerization is required for the cross-linking capacity of this allergen. In immunoblots, murine monoclonal and polyclonal human Bet v 1-specific Abs detected, besides a Bet v 1 monomer of 17 kDa, a dimer of 34 kDa. In dynamic light scattering, Bet v 1 appeared as dimers and even multimers, but a single condition could be defined where it behaved exclusively monomerically. Small-angle x-ray scattering of the monomeric and dimeric samples resulted in diagrams agreeing with the calculated models. Circular dichroism measurements indicated that the structure of Bet v 1 was preserved under monomeric conditions. Skin tests in Bet v 1-allergic mice were positive with Bet v 1 dimer, but remained negative using the monomer. Furthermore, in contrast to dimeric Bet v 1, the monomer was less capable of activating murine memory B cells for IgE production in vivo. Our data indicate that the presentation of two identical epitopes by dimerized allergens is a precondition for cross-linking of IgE on mast cells and B lymphocytes.

Recently, we have demonstrated that anti-ulcer drugs, such as H2-receptor blockers and proton pump inhibitors, promote the development of immediate type food allergy toward digestion-labile proteins in mice. The aim of this study was to examine the allergological relevance of these findings in humans. In an observational cohort study, we screened 152 adult patients from a gastroenterological outpatient clinic with negative case histories for atopy or allergy, who were medicated with H2-receptor blockers or proton pump inhibitors for 3 months. IgE reactivities to food allergens before and after 3 months of anti-acid treatment were compared serologically. Ten percent of the patients showed a boost of preexisting IgE antibodies and 15% de novo IgE formation toward numerous digestion-labile dietary compounds, like milk, potato, celery, carrots, apple, orange, wheat, and rye flour. Thus, the relative risk to develop food-specific IgE after anti-acid therapy was 10.5 (95% confidence interval: 1.44-76.48). The long-term effect was evaluated 5 months after therapy. Food-specific IgE could still be measured in 6% of the patients, as well as significantly elevated serum concentrations of ST2, a Th2-specific marker. An unspecific boost during the pollen season could be excluded, as 50 untreated control patients revealed no changes in their IgE pattern. In line with our previous animal experiments, our data strongly suggest that anti-ulcer treatment primes the development of IgE toward dietary compounds in long-term acid-suppressed patients.

Background: Phl p 5 represents a major allergen of timothy grass pollen (Phleum pratense). Detailed knowledge about the structures responsible for IgE binding would allow the design of a novel generation of allergy vaccines., Objective: We aimed to characterize the IgE epitopes of Phl p 5a using phage display combined with a molecular modeling approach., Methods: Phl p 5a-specific IgE from sera of patients with grass pollen allergy was used for screening of a random peptide phage library displaying constrained decamers., Results: Fifteen phage clones that shared sequence motifs and could be grouped into families were selected by using Phl p 5a-specific IgE. Peptide alignment with the solvent-accessible amino acids of Phl p 5a revealed 3 sequence sections with frequent hits of identical or similar amino acids. On the surface of Phl p 5a, these sections assembled in compact patches, most likely representing conformational IgE epitopes, whereas no matching clusters were found on the back sides of the 2 Phl p 5a halves. In surface plasmon resonance experiments, the high-affinity interaction between IgE and Phl p 5 could be competed by phage-displayed peptides up to 24%, indicating that they represent true epitope mimics (ie, mimotopes). Allergen-specific immunogenicity of the mimotopes was proved in Biozzi mice., Conclusion: The selected mimotopes facilitated the localization of conformational IgE epitopes of Phl p 5. We suggest them to be suitable candidates for the development of an epitope-specific immunotherapy.

Background: Kiwifruits have become a major elicitor of plant food allergy. Until recently, the only species of kiwifruit grown commercially was the common green-fleshed Actinidia deliciosa cv Hayward. In 1999, the yellow-fleshed cultivar Actinidia chinensis cv Hort16A was introduced into the international market., Objective: We compared the allergen compositions of green and gold kiwifruits and assessed the sensitization patterns of patients with kiwifruit allergy toward both varieties., Methods: Sera from 90 patients with kiwifruit allergy from Austria, central Italy, and the Netherlands were tested for IgE binding to green and gold kiwifruit protein extracts and to purified actinidin, the major kiwifruit allergen, by ELISA. In addition, ELISA inhibitions and immunoblots were performed with selected sera. Relevant allergens were identified by N-terminal sequencing and immunoblotting with allergen-specific antibodies., Results: IgE immunoblotting showed marked differences in the allergen compositions of green and gold kiwifruit extracts. Phytocystatin, a novel plant food allergen, and a thaumatin-like protein were identified as allergens common for both cultivars. Two allergens with homologies to chitinases were found in gold kiwifruits, whereas actinidin was detected exclusively in green kiwifruits. Patients from Central Europe and central Italy showed distinct sensitization profiles toward green and gold kiwifruit extracts as well as actinidin. Whereas sera from Austrian and Dutch patients mainly recognized green kiwifruit extract and actinidin, almost all Italian sera showed IgE binding to both kiwifruit species, but only half of them contained actinidin-specific IgE. Green and gold kiwifruit extracts were shown to be highly cross-reactive as determined by IgE ELISA inhibition., Conclusion: The presence of common allergens and the IgE cross-reactivity to green kiwifruit qualifies gold kiwifruit as a potential new allergen source for patients allergic to green kiwifruits.

Allergy diagnosis relying on the determination of specific IgE is frequently complicated by the presence of cross-reacting IgE of unclear clinical relevance. Particularly, the anaphylactogenic activity of IgE directed to cross-reactive carbohydrate moieties of glycoproteins from plants and invertebrates has been a matter of debate. In this study, we present the biochemical and immunological characterization of Api g 5, a glycoprotein allergen from celery with homology to FAD containing oxidases. Carbohydrate analysis of the allergen revealed the presence of glycans carrying fucosyl and xylosyl residues, structures previously shown to bind IgE. Chemical deglycosylation of the protein completely abolished binding of serum IgE from all 14 patients tested. Likewise, basophils from a patient allergic to mugwort pollen and celery were stimulated only by native Api g 5, whereas the deglycosylated allergen did not trigger release of histamine. IgE inhibition immunoblots showed that native Api g 5 other than the deglycosylated protein completely inhibited IgE binding to high molecular weight allergens in protein extracts from birch pollen, mugwort pollen, and celery. A similar inhibition was accomplished using the IgE binding oligosaccharide, MUXF, coupled to bovine serum albumin. All these observations taken together confer convincing evidence that IgE directed to cross-reactive carbohydrates is capable of eliciting allergic reactions in vivo.

Mal d 2 is a thaumatin-like protein and important allergen of apple fruits that is associated with IgE-mediated symptoms in apple allergic individuals. We obtained a full-length cDNA clone of Mal d 2 from RNA isolated from ripe apple (Malus domestica cv. Golden Delicious). The cDNA's open reading frame encodes a protein of 246 amino acid residues including a signal peptide of 24 residues and two putative glycosylation sites. The deduced amino acid sequence of the mature Mal d 2 protein results in a predicted molecular mass of 23,210.9Da and a calculated pI of 4.55. Sequence comparisons and molecular modeling place Mal d 2 among those pathogenesis-related thaumatin-like proteins that contain a conserved acidic cleft. In order to ensure the correct formation of the protein's eight conserved disulfide bridges we expressed Mal d 2 in Nicotiana benthamiana plants by the use of a tobacco mosaic viral vector. Transfected N.benthamiana plants accumulated Mal d 2 to levels of at least 2% of total soluble protein. MALDI-TOF mass spectrometric analyses of the recombinant Mal d 2 and its proteolytic fragments showed that the apple-specific leader peptide was correctly cleaved off by the host plant and that the mature recombinant protein was intact and not glycosylated. Purified recombinant Mal d 2 displayed the ability to bind IgE from apple-allergic individuals equivalent to natural Mal d 2. In addition, the recombinant thaumatin-like Mal d 2 exhibited antifungal activity against Fusarium oxysporum and Penicillium expansum, implying a function in plant defense against fungal pathogens.

BackgroundIgE antibodies play a paramount role in the pathogenesis of various intestinal disorders. To gain insights in IgE-mediated pathophysiology of the gut, we investigated the expression of the high affinity IgE receptor Fc epsilonRI in human intestinal epithelium.Methodology/principal findingsFc epsilonRI alpha-chain, as detected by immunohistochemistry, was positive in epithelial cells for eight of eleven (8/11) specimens from colon cancer patients and 5/11 patients with inflammation of the enteric mucosa. The Fc epsilonRIalpha positive epithelial cells co-expressed Fc epsilonRIgamma, whereas with one exception, none of the samples was positive for the beta-chain in the epithelial layer. The functionality of Fc epsilonRI was confirmed in situ by human IgE binding. In experiments with human intestinal tumor cell lines, subconfluent Caco-2/TC7 and HCT-8 cells were found to express the alpha- and gamma-chains of Fc epsilonRI and to bind IgE, whereas confluent cells were negative for gamma-chains.Conclusions/significanceOur data provide the first evidence that the components of a functional Fc epsilonRI are in vitro expressed by the human intestinal epithelial cells depending on differentiation and, more importantly, in situ in epithelia of patients with colon cancer or gastrointestinal inflammations. Thus, a contribution of Fc epsilonRI either to immunosurveillance or pathophysiology of the intestinal epithelium is suggested.

BackgroundIgE antibodies play a paramount role in the pathogenesis of various intestinal disorders. To gain insights in IgE-mediated pathophysiology of the gut, we investigated the expression of the high affinity IgE receptor Fc epsilonRI in human intestinal epithelium.Methodology/principal findingsFc epsilonRI alpha-chain, as detected by immunohistochemistry, was positive in epithelial cells for eight of eleven (8/11) specimens from colon cancer patients and 5/11 patients with inflammation of the enteric mucosa. The Fc epsilonRIalpha positive epithelial cells co-expressed Fc epsilonRIgamma, whereas with one exception, none of the samples was positive for the beta-chain in the epithelial layer. The functionality of Fc epsilonRI was confirmed in situ by human IgE binding. In experiments with human intestinal tumor cell lines, subconfluent Caco-2/TC7 and HCT-8 cells were found to express the alpha- and gamma-chains of Fc epsilonRI and to bind IgE, whereas confluent cells were negative for gamma-chains.Conclusions/significanceOur data provide the first evidence that the components of a functional Fc epsilonRI are in vitro expressed by the human intestinal epithelial cells depending on differentiation and, more importantly, in situ in epithelia of patients with colon cancer or gastrointestinal inflammations. Thus, a contribution of Fc epsilonRI either to immunosurveillance or pathophysiology of the intestinal epithelium is suggested.

Background: The association of pollinosis with allergy to plant foods occurs in up to 70% of tree pollen-allergic patients. In recent years, some of the relevant cross-reacting proteins have been characterized at the molecular and immunological level. Api g 1 has been identified as the celery homologue of the major birch pollen allergen, Bet v 1. Although a number of Bet v 1 isoforms have been characterized from birch pollen, little is known about isoforms of food allergens and their allergenic features. Methods: Api g 1.0201, an isoform of Api g 1, was isolated from a cDNA library, cloned and sequenced. The cDNA was expressed in Escherichia coli and the purified recombinant protein was tested in immunoblots. Results: Api g 1.0201 displays 72% sequence similarity to the previously identified Api g 1.0101 and consists of 159 amino acid residues. The sequence of Api g 1.0201 has five additional amino acid residues at the carboxy-terminus as compared to Api g 1.0101. Purified recombinant Api g 1.0201 is recognized by IgE from the sera of celery-allergic patients, as well as by the murine monoclonal anti-Bet v 1 antibody. In general, this isoform displays a weaker IgE-binding capacity than Api g 1.0101, as concluded from immunoblotting experiments. Results from inhibition assays revealed that IgE-binding to Api g 1.0201 is only slightly reduced by preincubation with either purified recombinant Api g 1.0101 or purified recombinant Bet v 1a. Total inhibition was only achieved when using purified natural Bet v 1. Conclusions: At present, little is known about the IgE-binding capacity of isoforms of Bet v 1 homologues of food allergens. Identification and characterization of such isoforms may help to contribute to a better understanding of food allergy and the observed cross-reactivity to pollen allergy.Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Little is known about the role of bell peppers in food allergy. We collected sera from 11 patients with food allergy to bell peppers to analyze bell pepper extracts for allergen composition. Methods: Proteins of mature fruits of eight horticultural strains of bell peppers were extracted and tested with patients’ sera for IgE binding and with monoclonal and polyclonal antibodies in immunoblot. Results: Profilin was detected in bell pepper extracts by an anti-celery profilin antibody. It showed high IgE binding activity in all extracts, which could be inhibited by recombinant birch pollen profilin. Anti-birch pollen monoclonal antibody BIP3, directed against birch pollen proteins between 30 and 69 kD, bound to bell pepper antigens of comparable molecular weights. A homologue of the major birch pollen allergen Bet v 1 was detected in four of eight horticultural strains of bell peppers, and was shown to bind IgE in 1 of the 11 patients. A 23-kD allergen of bell peppers was shown to correspond to the 23-kD major paprika allergen by IgE absorption experiments. Its N-terminal sequence showed 100% identity to P23 from tomatoes. Conclusion: The appearance of profilin in all and Bet v 1 in 50% of the tested horticultural strains indicates that bell peppers have to be considered potentially dangerous for Bet v 1- and profilin-sensitized patients. Moreover, in 4 of 8 horticultural strains of bell peppers a homologue of the osmotin-like protein P23 from tomatoes is responsible for substantial IgE binding. Contact with Bet v 1 and P23 homologues in bell peppers can therefore be minimized by avoidance of the respective horticultural strains. [ABSTRACT FROM AUTHOR]

Background: The prevalence of allergy to fruits and vegetables increased with pollinosis over the last 10 years. So far, clusters of hypersensitivity have been established and corroborated by the molecular characterization of individual cross-reacting allergens. Several case studies demonstrated the existence of allergic reactions to fruits of the subfamily Prunoideae (apricots, cherries, plums and peaches). Here, we present the characterization of a major allergen in cherry. Methods: Characterization was performed using IgE immunoblotting and immunoblot inhibition, N-terminal sequencing, mass spectroscopy analysis and PCR-based cDNA cloning. Results: A 23-kD protein was identified as IgE-binding component. As all cherry-extract-reactive sera displayed IgE-binding to this band, it was designated a major allergen from Prunus avium (Pru a 2). Sequencing the corresponding cDNA identified Pru a 2 as a thaumatin-like protein belonging to the group 5 of pathogenesis-related proteins. Conclusions: A thaumatin-like protein in cherry has been identified as a major allergen (Pru a 2). Homologous proteins from the thaumatin family share sequence similarities and should therefore be checked for the capability to elicit an IgE-mediated allergic reaction. [ABSTRACT FROM AUTHOR]

Background: An association of Crohn’s disease (CD) with food allergy has been discussed, but the role of food-specific IgE has not been clarified yet. Since CD is combined with immune complex formation, we examined in the present study whether anti-IgE autoantibodies in such complexes might hinder the determination of specific IgE. Methods: In order to elucidate the role of food-specific IgE in CD, we tested sera from CD patients (n = 107), healthy controls (n = 65) and allergics subjects (n = 7) for their IgE binding to food antigens (yeast, corn, celeriac, wheat) by an immunodot assay. After determining levels of IgE/IgG anti-IgE immune complexes, we purified them from serum pools of patients with CD, allergic subjects and healthy controls by affinity absorption using a monoclonal anti-IgE antibody. These purified immune complexes were treated by low pH (pH = 4) in order to dissolve them and to increase the detectability of food-specific IgE by RAST and CAP assay. Results: In CD sera no food-specific IgE could be detected, but levels of immune complexes of IgE and IgG anti-IgE autoantibodies were statistically significantly increased compared to healthy controls. pH treatment of purified IgE/IgG anti-IgE immune complexes resulted in a significant increase in specific IgE to yeast, corn, wheat and celeriac detected by RAST, however, only in the serum sample purified from allergic subjects. After pH treatment of CD immune complexes, specific IgE levels remained still very low. Conclusion: Thus, even if IgE seems to represent an autoantigen in CD, it is unlike to specifically participate in the pathophysiology of the putative food adverse reactions. [ABSTRACT FROM AUTHOR]

Previous studies showed that pollens from trees of the order Fagales (e.g. birch, alder, hazel and hornbeam) all contain one major allergen. These proteins are cross-reactive between these tree species, and approximately 95% of tree-pollen-allergic patients display IgE binding m these allergens. Using the reported N-terminal amino acid sequence of the hazel pollen allergen Cor aI, it was possible to amplify Cor-a-I cDNA by use of the polymerase chain reaction. Four clones with cDNA inserts were isolated. All four clones contained an open reading frame of 477 nucleotides (159 amino acids) but differed in length of their 3′-non-coding regions. Within the overlapping regions, the nucleotide sequence of the 3′-non-coding regions of the four clones were nearly identical. The open reading frames coded for different isoforms of the major hazel pollen allergen, Cor aI. The clones were designated Cor a I/5, 6, 11 and 16, respectively. Comparison of the deduced amino acid sequences of these Cor aI isoforms revealed identifies of 96–99%. The sequence identities between the Cor aI isoforms and Bet vI, the major birch pollen allergen, were 71–73% (80.5–83% similarity). Comparing amino acid sequences of Cor aI isoforms with the published sequences of Aln gI, the major allergen from alder, and Car bI and isoforms, the major allergen from hornbeam, 75.5–76.7% identity (83.6–85% similarity) and 83.6–89.9% sequence identity (89.3–95% similarity), respectively, was found. The four Cor aI cDNAs were subcloned into plasmid pKK223-3 and expressed in Escherichia coli as non-fusion proteins; their capacity to bind serum IgE from tree-pollen-allergic patients was investigated. The four cloned isoforms showed an apparent molecular mass of 17 kDa in SDS/PAGE, identical to the natural, pollen-derived Cor aI. IgE antibodies from tree-pollen-allergic patients reacted with all four recombinant isoforms. However, we noted marked differences in the IgE-binding patterns of the distinct isoforms. Furthermore, Cor a I/11 was the only isoform recognized by the anti-(Bet vI) mAb, BIP 1. Our results demonstrate that Cor aI isoforms display different antigenic and allergenic properties, very likely due to few but significant changes in their amino acid sequences. These findings have implications for the development of reagents for diagnosis and immunotherapy of type I allergies. [ABSTRACT FROM AUTHOR]

Background: The induction of nonanaphylactogenic ‘blocking’ IgG antibodies capable of inhibiting the IgE/allergen interaction represents a favorable therapeutic concept for type I allergy. However, IgG antibodies to allergens may block or enhance specific IgE binding, depending on the recognized epitope. Taking the major birch pollen allergen Bet v 1 as a model, we developed a strategy for the precise induction of IgG antibodies of a desired epitope specificity. Methods: Random phage display peptide libraries were applied to define peptide structures mimicking natural epitopes (mimotopes) of Bet v 1. Selections were performed with BIP 1, a murine monoclonal antibody known to enhance the IgE binding to Bet v 1, and with anti-Bet v 1 IgE purified from patients’ sera. The characterized Bet v 1 mimotopes were used to localize the corresponding epitope at the surface of Bet v 1 by a computer-aided mathematical approach based on the three-dimensional structure and the chemical character of the amino acids. The Bet v 1 mimotopes were further used to immunize BALB/c mice. The specificity of the induced antibodies was tested by immunoblotting and inhibition assays. Results: With the three-dimensional epitope search it became possible to localize a discontinuous IgE epitope on the surface of Bet v 1 in a substantial distance from the IgG epitope of the monoclonal antibody BIP 1. Moreover, we could demonstrate that phage displaying mimotopes are immunogenic vectors for the precise induction of epitope-specific IgG. Immunization with BIP 1 mimotopes induced IgG enhancing the IgE binding to Bet v 1, whereas immunization with IgE mimotopes resulted in IgG capable of blocking human IgE binding in vitro. Conclusion: Allergen mimotopes can be used for the induction of anti allergen IgG of desired specificity. We propose that mimotope immunotherapy based on IgE mimotopes generated by biopannings may represent a future concept for therapy of type I allergy.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Parvalbumin, the major fish allergen, is recognized by allergen-specific IgE of more than 90% of all fish-allergic patients. A detailed knowledge of allergenic structures is crucial for developing a vaccine inducing blocking antibodies specifically directed towards the IgE binding epitopes. In the present study we aimed to use the phage display technique to generate mimotopes, which mimic epitopes on parvalbumin. Parvalbumin-specific IgE was purified from sera of fish-allergic patients and used for screening of a constrained decamer phage library. After four rounds of biopanning using parvalbumin-specific IgE, five phage clones were selected which were specifically recognized by parvalbumin-specific IgE as well as IgG. DNA sequencing and peptide alignment revealed a high degree of sequence similarities between the mimotopes. Interestingly, on the surface of natural parvalbumin three regions could be defined by computational mimotope matching. In accordance, previously defined allergenic peptides of cod parvalbumin highlighted areas in close proximity or overlapping with the mimotope matching sites. From the presented data we conclude that our approach identified conformational epitopes of parvalbumin relevant for IgE and IgG binding. We suggest that these mimotopes are suitable candidates for an epitope-specific immunotherapy of fish-allergic patients. [Copyright &y& Elsevier]