Identification Of IgE-binding Proteins Research Articles

Identification of the Most Common Allergens of Acer velutinum Pollen.

Pollens have been identified as potent inducers of allergic diseases worldwide. Acer velutinum (Persian maple) tree is an important source of allergic pollens in Iran. This study aimed to identify the immunoglobulin E (IgE)-reactive components of A. velutinum pollen extract in patients with maple allergy. We aimed to evaluate its allergenic components; using IgE in the serum of patients with maple allergy. Twenty-two patients with a clinical history of reaction and a positive skin-prick test to maple pollen extract were included in this study. Identification of IgE-binding proteins in A. velutinum pollen extract was performed by immunoblotting using sera from sensitive patients. A protein band with a molecular weight of around 70 kDa was the most IgE-reactive allergen in A. velutinum pollen extract detected by this method. Identification of a protein with a molecular weight of about 70kDa, as the most reactive allergen of A. velutinum pollen extract, can be considered as a potential allergen for designing diagnostic kits or as a target for immunotherapy of allergic patients with maple allergy.

Survey of IgE Reactivity to Nonbiting Midges in Korea and Identification of IgE-Binding Protein.

PurposeChironomids (nonbiting midges) are widely and abundantly distributed near ponds, rivers, and artificially dammed pools used for irrigation. Chironomids contain allergens and cause airway allergy in humans. In this study, we aimed to examine the allergic potential of chironomids in inhabitants living near artificially dammed pools.MethodsWe examined immunoglobulin E (IgE) reactivity to chironomid extracts in the sera of residents living around installed dams and assessed the correlations of IgE responses between chironomids (Chironomus flaviplumus, Chironomus kiiensis, Cricotopus bicinctus) and house dust mites (Dermatophagoides farinae). In addition, we identified potential IgE binding proteins specific for adult C. bicinctus, a popular species in Korea. Specific IgE antibodies in sera collected from the participants against the extracts were tested using enzyme-linked immunosorbent assay (ELISA).ResultsThe average IgE-positive rates were 10.4%, 8.1%, and 8.2% in C. bicinctus, C. flaviplumus, and C. kiiensis, respectively. The IgE-positive rate and IgE titer of C. bicinctus antigen were higher in residents living around installed dams than in those who lived other places (P = 0.013). Western blotting using sera having high IgE titers to C. bicinctus in ELISA showed the presence of a protein of approximately 42 kDa that was homologous to the actin protein isoform in C. bicinctus extracts as demonstrated using mass spectrometry.ConclusionsOur results showed that people living near installed dams were more sensitized to C. bicinctus and that the 42 kDa IgE-binding protein could be useful for further studies on chironomid allergic disease and clinical applications.

Proteins derived from Prunus armeniaca kernel are possible to cause Immunoglobulin E reactivity in human sera

Allergic diseases are always caused by protein molecules and in most cases arise in individuals with documented immunologic reactions to foods, pollen, or plant IgE. However, proteins derived from herbal medicine which act as an allergen have not been widely studied. Here, we aim to confirm if the herbal medicine Prunus armeniaca kernel at the proteomic level triggers IgE immunoreactivity. If it does, we can hypothesize what components of protein molecules in the herbal medicine Prunus armeniaca kernel react with and bind to IgE. To test this hypothesis, we utilized proteomic tools and SDS-PAGE stained with Coomassie blue and identified proteins using LC-MS/MS. We also assessed the degree of plasma IgE reactivity in an isolated protein of Prunus armeniaca kernel using western blots of human IgE and an enzyme immunoassay panel, the Allergy-Q test, in 400 human sera. As a result, we found three sera which were positive candidates as Prunus armeniaca kernel IgE binding proteins. The results imply that Prunus armeniaca kernel can act as an allergen given the identification of IgE binding proteins among the isolated proteins of Prunus armeniaca kernel.

Identification of IgE-binding proteins in buckwheat

Background Buckwheat (Fagopyrum esculentum) is not only common pseudo-cereal in Japan, Korea, and other East Asian countries, but also a health food and substitute for wheat flour in Western countries. Buckwheat allergy is an immunoglobulin E (IgE)-mediated hypersensitivity manifesting as severe and critical symptoms induced by ingestion or inhalation of even a small amount of the flour or food products. It is therefore important to identify buckwheat IgE-binding proteins and clarify the mechanism of buckwheat allergy for developing an accurate diagnostic procedure and safer immunotherapy.

Oriental plane pollen allergy: Identification of allergens and cross-reactivity between relevant species

Pollen from different tree and grass species represent the greatest inducers of type I allergy worldwide. Oriental plane trees, as Platanus orientalis, are an important source of airborne allergens in cities of the southwest Asia and southeast Europe. This study was aimed to identify relevant allergens of P. orientalis pollen and to ascertain whether P. orientalis allergens have cross-reactivity with related plane trees, such as Platanus acerifolia and Platanus occidentalis pollen components. Nineteen patients with a clinical history of reaction to P. orientalis pollen and a positive skin-prick test (SPT) to P. orientalis pollen extract were included in this study. Identification of IgE-binding proteins in Platanus pollen extracts was elucidated by immunoblotting using sera from P. orientalis pollen-sensitive patients. Cross-reactivity studies among P. orientalis allergens and relevant species was evaluated by immunoblot-inhibition and ELISA inhibition assays. All the patients were polysensitive and exhibited positive SPT to grass and tree pollen allergens. The IgE-binding pattern of P. orientalis pollen extract was well defined. The inhibition experiments showed that the capacity of P. occidentalis was greater than P. acerifolia pollen extract in preventing the reactivity of immobilized P. orientalis pollen extract with the IgE antibodies of patients. The 28-kDa molecule was the most frequent allergen among nine IgE-binding proteins of P. orientalis pollen. The IgE-reactive components of P. orientalis pollen showed a higher level of cross-reactivity with P. occidentalis pollen in comparison with P. acerifolia pollen.

Identification of IgE-binding proteins of Thunnus tonggol (tongkol) by mass spectrometry analysis

Identification of IgE-binding proteins of Thunnus tonggol (tongkol) by mass spectrometry analysis

Identification and Characterisation of the IgE-Binding Proteins 2S Albumin and Conglutin γ in Almond (Prunus dulcis) Seeds

Background: Almond proteins can cause severe anaphylactic reactions in susceptible individuals. The aim of this study was the identification of IgE-binding proteins in almonds and the characterisation of these proteins by N-terminal sequencing. Methods: Five sera were selected from individuals with a positive reaction to food challenge. Sodium dodecylsulphate-polyacrylamide gel electrophoresis and immunoblotting were performed on almond seed proteins. Purified IgE-binding proteins were tested for immunoblot inhibition with sera pre-incubated with extracts of hazelnut and walnut. Results: N-terminal sequences of the 12-, 30- and 45-kD proteins were obtained. The 45- and 30-kD proteins shared the same N terminus, with 60% homology to the conglutin γ heavy chain from lupine seed (Lupinus albus) and to basic 7S globulin from soybean (Glycine max). The sequences of the N-terminal 12-kD protein and of an internal peptide obtained by endoproteinase digestion showed good homology to 2S albumin from English walnut (Jug r 1). Immunoblot inhibition experiments were performed and IgE binding to almond 2S albumin and conglutin γ was detected in the presence of cross-reacting walnut or hazelnut antigens. Conclusions: Two IgE-binding almond proteins were N-terminally sequenced and identified as almond 2S albumin and conglutin γ. Localisation and conservation of IgE binding in a 6-kD peptide obtained by endoproteinase digestion of 2S albumin was shown.

Identification of IgE-Binding Proteins in Soy Lecithin

Background: Soy lecithin is widely used as an emulsifier in processed foods, pharmaceuticals and cosmetics. Soy lecithin is composed principally of phospholipids; however, it has also been shown to contain IgE-binding proteins, albeit at a low level. A few clinical cases involving allergic reactions to soy lecithin have been reported. The purpose of this investigation is to better characterize the IgE-binding proteins typically found in lecithin. Methods: Soy lecithin proteins were isolated following solvent extraction of lipid components and then separated on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The separated lecithin proteins were immunoblotted with sera from soy-sensitive individuals to determine the pattern of IgE-binding proteins. The identity of IgE-reactive bands was determined from their N-terminal sequence. Results: The level of protein in six lecithin samples obtained from commercial suppliers ranged from 100 to 1,400 ppm. Lecithin samples showed similar protein patterns when examined by SDS-PAGE. Immunoblotting with sera from soy-sensitive individuals showed IgE binding to bands corresponding to 7, 12, 20, 39 and 57 kD. N-terminal analysis of these IgE-binding bands resulted in sequences for 3 components. The 12-kD band was identified as a methionine-rich protein (MRP) and a member of the 2S albumin class of soy proteins. The 20-kD band was found to be soybean Kunitz trypsin inhibitor. The 39-kD band was matched to a soy protein with unknown function. Conclusions: Soy lecithin contains a number of IgE-binding proteins; thus, it might represent a source of hidden allergens. These allergens are a more significant concern for soy-allergic individuals consuming lecithin products as a health supplement. In addition, the MRP and the 39-kD protein identified in this study represent newly identified IgE-binding proteins.

Identification of IgE-binding proteins from Lepidoglyphus destructor and production of monoclonal antibodies to a major allergen

The allergen composition of one of the most important storage mites, Lepidoglyphus destructor, has been studied by immunodetection after SDS-PAGE with individual patient sera. An allergenic polypeptide of 14 kDa was identified with 95% of the sera. This major allergen was isolated in the supernatant of 60% ammonium sulfate salt precipitation of the whole extract, which was subsequently used to immunize BALB/c mice so as to produce monoclonal antibodies. Four mAbs recognizing molecules with IgE-binding ability were obtained. The specificity of the mAbs was assayed against different allergenic extracts, and the molecules recognized by them were characterized by immunoblotting. Two mAbs (Le5B5 and Le9E4) were directed to the 14-kDa allergen; the other two to several proteins of lesser allergenic significance.