Quality and potency profile of eight recombinant isoallergens, largely mimicking total Bet v 1-specific IgE binding of birch pollen.
Clin Exp Allergy
; 49(5): 712-723, 2019 05.
Article
em En
| MEDLINE
| ID: mdl-30706562
ABSTRACT
BACKGROUND:
To date, only limited information on structure, expression levels and IgE binding of Bet v 1 variants, which are simultaneously expressed in birch pollen, is available.OBJECTIVE:
To analyse and compare structure and serum IgE/IgG binding of rBet v 1 variants to Bet v 1.0101.METHODS:
Recombinant Bet v 1 variants were studied with sera of 20 subjects allergic to birch pollen. Folding, aggregation and solubility of the rBet v 1 variants were analysed to attribute diverging IgE binding to either allergen structure or methodological features. IgE/IgG binding was studied with rBet v 1 in solution or adsorbed to solid phases. Allergen-mediated cross-linking of FcεRI receptors was determined by mediator release of sensitized humanized rat basophil leukaemia cells.RESULTS:
All variants, except for rBet v 1.0113, were monomeric and had Bet v 1-type conformation. Serum IgE binding to variants adsorbed to solid phase was reduced to 6.6%-36.5% compared with Bet v 1.0101. In contrast, inhibition of IgE binding to Bet v 1.0101 by rBet v 1 variants ranged from 62% to 83%. Similarly, mediator release ranged from 30.7% to 55.2% for all variants and was only clearly reduced for rBet v 1.0301 (10.4%). The IgE-binding potency of rBet v 1 variants representing their native quantities in birch pollen was only slightly lower compared to extract. IgG binding to variants was between 50.9% and 134.5% compared with rBet v 1.0101 (100%). CONCLUSION AND CLINICAL RELEVANCE Bet v 1 variants previously classified as hypoallergenic can exhibit similar functional IgE binding as Bet v 1.0101. Eight rBet v 1 variants largely reproduce total Bet v 1-specific IgE binding of birch pollen extracts. Assay format-dependent variation in IgE-binding properties needs to be considered in the development of diagnostic or therapeutic products.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Pólen
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Imunoglobulina E
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Betula
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Antígenos de Plantas
Limite:
Animals
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article