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Identification of a Dau c PRP like protein (Dau c 1.03) as a new allergenic isoform in carrots (cultivar R odelika )
Author(s) -
Wangorsch A.,
Weigand D.,
Peters S.,
Mahler V.,
Fötisch K.,
Reuter A.,
Imani J.,
DeWitt Å. M.,
Kogel K.H.,
Lidholm J.,
Vieths S.,
Scheurer S.
Publication year - 2012
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2011.03900.x
Subject(s) - gene isoform , immunoglobulin e , in vitro , microbiology and biotechnology , chemistry , daucus carota , allergen , reactivity (psychology) , potency , biology , allergy , biochemistry , immunology , gene , botany , antibody , medicine , alternative medicine , pathology
Abstract Background Up to 25% of food allergic subjects in central E urope suffer from carrot allergy. Until now, two isoforms of the major carrot ( D aucus carota ) allergen Dau c 1 have been described: Dau c 1.01, comprising five variants (Dau c 1.0101–Dau c 1.0105) and Dau c 1.02. Objective To investigate potential allergenic properties of a Dau c PRP like protein, a novel isoform of the PR ‐10 protein family in carrot. Methods Dau c PRP like cDNA from carrot roots (cv R odelika ) was cloned after RT‐PCR and 5′RACE. Dau c PRP like protein was expressed in E . coli , purified under native conditions by Ni‐NTA chromatography and analysed by CD spectroscopy. Immuno‐reactivity of the rD au c PRP like protein was compared with rD au c 1.0104 and rD au c 1.0201 in terms of IgE binding (immunoblotting, ImmunoCAP ™ ), IgE cross‐reactivity (ELISA inhibition) and in vitro mediator release with sera from carrot allergic patients. mRNA expression of Dau c PRP like protein in wild‐type and transgenic carrot roots was analysed by qRT ‐ PCR . Results The Dau c PRP like protein was identified as a new allergenic isoform, Dau c 1.03, in carrot roots. 68% of carrot allergic patients were sensitized to rD au c 1.03. The IgE‐reactivity of rD au c 1.03 strongly correlated with reactivity to rD au c 1.0104, but not to rD au c 1.0201. The extent of IgE cross‐reactivity and allergenic potency of Dau c 1 isoforms varied between the individual sera tested. Dau c 1.03 mRNA transcripts were up‐regulated in Dau c 1.01 and Dau c 1.02 gene‐silenced carrot roots. Conclusion and clinical relevance Dau c 1 isoforms display distinct IgE epitope heterogeneity. Dau c 1.03 appears to contribute to the allergenicity of carrots and the manifestation of carrot allergy. The epitope diversity of different Dau c 1 isoforms should be considered for component‐resolved diagnosis and gene silencing of carrot allergens.