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Pru p 3, the nonspecific lipid transfer protein from peach, dominates the immune response to its homolog in hazelnut

Authors


  • Edited by: Reto Crameri

Barbara Bohle, PhD, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18–20, AKH-3Q, A-1090 Wien, Austria.
Tel.: 43-1-40400-5114
Fax: 43-1-40400-5130
E-mail: barbara.bohle@meduniwien.ac.at

Abstract

To cite this article: Schulten V, Nagl B, Scala E, Bernardi ML, Mari A, Ciardiello MA, Lauer I, Scheurer S, Briza P, Jürets A, Ferreira F, Jahn-Schmid B, Fischer GF, Bohle B. Pru p 3, the nonspecific lipid transfer protein from peach, dominates the immune response to its homolog in hazelnut. Allergy 2011; 66: 1005–1013.

Abstract

Background:  Nonspecific lipid transfer proteins (nsLTPs) are important food allergens. Often, patients allergic to the nsLTP in peach suffer from allergy to hazelnuts. We aimed to analyse the T-cell response to Cor a 8, the nsLTP in hazelnut and its immunological cross-reactivity with the nsLTP in peach, Pru p 3.

Methods:  Cor a 8-reactive T-cell lines (TCL) established from patients allergic to hazelnut and peach were stimulated with 12-mer peptides representing the complete amino acid sequence of Cor a 8 to identify its T-cell-activating regions and with Pru p 3 to investigate cellular cross-reactivity. T-cell clones specific for different major T-cell-activating regions of Pru p 3 were stimulated with Cor a 8. Both nsLTPs were subjected to endolysosomal degradation assays. Immunoglobulin E (IgE) cross-reactivity between Cor a 8 and Pru p 3 was assessed in inhibition enzyme-linked immunosorbent assay.

Results:  No major T-cell-activating region was found among 26 T-cell-reactive peptides identified in Cor a 8. Although generated with Cor a 8, 62% of the TCL responded more strongly to Pru p 3. This cross-reactivity was mediated by T cells specific for the immunodominant region Pru p 361–75. Peptide clusters encompassing this region were generated during lysosomal degradation of both nsLTPs. Cor a 8 was more rapidly degraded by lysosomal proteases than Pru p 3. Pre-incubation of sera with Pru p 3 completely abolished IgE binding to Cor a 8, which was not the case vice versa.

Conclusions:  T-cell reactivity to Cor a 8 is predominantly based on cross-reactivity with Pru p 3, indicating that the latter initiates sensitisation to its homolog in hazelnut. The limited allergenic potential of Cor a 8 seems to be associated with rapid lysosomal degradation during allergen processing and the lack of major T-cell-activating regions.

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