Su1863 Component-Resolved Diagnostics Demonstrate Birch Pollen Sensitization With Cross-Reactivity to Food Allergens in Adult Eosinophilic Esophagitis

In many cases, patients allergic to birch pollen also show allergic reactions after ingestion of certain fruits or vegetables. This observation is explained at the molecular level by cross-reactivity of IgE antibodies induced by sensitization to the major birch pollen allergen Bet v 1 with homologous food allergens. As IgE antibodies recognize conformational epitopes, a precise structural characterization of the allergens involved is necessary to understand cross-reactivity and thus to develop new methods of allergen-specific immunotherapy for allergic patients. Here, we report the three-dimensional solution structure of the soybean allergen Gly m 4, a member of the superfamily of Bet v 1 homologous proteins and a cross-reactant with IgE antibodies originally raised against Bet v 1 as shown by immunoblot inhibition and histamine release assays. Although the overall fold of Gly m 4 is very similar to that of Bet v 1, the three-dimensional structures of these proteins differ in detail. The Gly m 4 local structures that display those differences are also found in proteins from yellow lupine with known physiological function. The three-dimensional structure of Gly m 4 may thus shed some light on the physiological function of this subgroup of PR10 proteins (class 10 of pathogenesis-related proteins) and, in combination with immunological data, allow us to propose surface patches that might represent cross-reactive epitopes.

Download Full-text

Crossreactive allergen-specific IgE in children with birch pollen allergic rhinitis

Rossiiskii Allergologicheskii ZHurnal ◽

10.36691/rja325 ◽

2017 ◽

Vol 14 (2) ◽

pp. 66-70

Author(s):

P V Samoylikov ◽

S A Mazurina ◽

P I Gushchin ◽

V B Gervazieva

Keyword(s):

Allergic Rhinitis ◽

Birch Pollen ◽

Humoral Response ◽

Specific Ige ◽

Cross Reactivity ◽

Oral Allergy Syndrome ◽

Food Allergens ◽

Homologous Proteins ◽

Total Ige ◽

Bet V 1

Objective. The aim of this study was to research a sIgE allergen profile of birch pollen and to evaluate a contribution of some homologous food allergens as well as latex allergen to the development of sensibility in allergic rhinitis (AR) / rhinoconjunctivitis patients, in focus of cross-reactivity and oral allergy syndrome.. Methods. Blood sera of 21 AR/rhinoconjunctivitis patients (at the age of 3 to 16) and 20 healthy persons without allergy symptoms were used. sIgE to birch pollen, soybean, latex, apple and celery as well as the total IgE levels were measured by the ImmunoCAP method (Phadia, Sweden) and the ELISA kits (Alkorbio, Russia). Results. We detected high total IgE levels, sIgE to allergens of birch pollen, apple, celery, as well as to recombinant allergens of birch Bet v 1, Bet v 2 and soybean - Gly m 4 in AR patients. Correlation analysis of IgE humoral response to homologous proteins showed the direct valid dependence between the sIgE levels to birch isoallergen Bet v 1 and soy isoallergen Gly m 4 (r=0,84; p

Download Full-text

Common food allergens and cross-reactivity

Journal of Food Allergy ◽

10.2500/jfa.2020.2.200020 ◽

2020 ◽

Vol 2 (1) ◽

pp. 17-21

Author(s):

Olivia L. Francis ◽

Kathleen Y. Wang ◽

Edwin H. Kim ◽

Timothy P. Moran

Keyword(s):

Food Allergy ◽

Protein Stability ◽

Cross Reactivity ◽

Molecular Characteristics ◽

Food Allergens ◽

Tree Nuts ◽

Heat Stable ◽

Systemic Reactions ◽

Hen’S Egg ◽

Fish And Shellfish

The most clinically relevant food allergens are cow’s milk, hen’s egg, peanut, tree nuts, wheat, soy, fish, shellfish, and seeds. Heat-stable food allergens have molecular characteristics that enhance protein stability and gastrointestinal absorption and thus are more likely to cause systemic reactions on ingestion. In contrast, heat-labile food allergens lack these characteristics and do not typically elicit reactions if sufficiently altered by heat or acid. Immunologic cross-sensitization between food allergens is more common than clinical cross-reactivity. However, certain groups of food allergens, such as tree nuts, fish, and shellfish, are associated with high rates of clinical cross-reactivity. Knowing the rates of clinical cross-reactivity is important when providing guidance to patients with food allergy and families on what foods can be safely added to the diet and what foods should be avoided.

Download Full-text

Purification and characterization of natural Ara h 8, the Bet v 1 homologous allergen from peanut, provides a novel isoform

Biological Chemistry ◽

10.1515/bc.2008.038 ◽

2008 ◽

Vol 389 (4) ◽

pp. 415-423 ◽

Cited By ~ 20

Author(s):

Susanne Riecken ◽

Buko Lindner ◽

Arnd Petersen ◽

Uta Jappe ◽

Wolf-Meinhard Becker

Keyword(s):

Birch Pollen ◽

Diagnostic Procedures ◽

Cross Reactivity ◽

Exchange Chromatography ◽

Size Exclusion ◽

Reactive Protein ◽

Bet V 1 ◽

Peanut Extract ◽

Natural Counterpart

Abstract The peanut allergen Ara h 8 is an important allergen for birch pollen allergic patients because of the cross-reactivity to the homologous Bet v 1. As the existence of Ara h 8 has been shown at the cDNA level so far (AY328088) and the allergen has indirectly been detected as natural protein, it was the aim of our study to identify natural Ara h 8 in peanut extract and to develop a purification strategy. This was achieved using a unique combination of purification steps, including optimized extraction conditions, size exclusion and ion exchange chromatography and treatment of the interfering contaminants with iodo-acetic acid. A characterization of the protein by microsequencing showed discrepancies to the deduced amino acid sequence of AY328088. For this reason, we cloned and expressed a new Ara h 8 isoform from cDNA (EU046325). This IgE-reactive protein corresponds to the results of microsequencing, ESI-FTICR-MS and trypsin fingerprinting analysis of the authentic and purified nAra h 8. Apart from the ultimate use of recombinant allergens for diagnostic procedures, there is also a scientific need for the natural counterpart, as it represents an excellent reference point by which to compare protein characteristics and to standardize diagnostic and therapeutic allergens.

Download Full-text