Cor a 1-reactive T cells and IgE are predominantly cross-reactive to Bet v 1 in patients with birch pollen-associated food allergy to hazelnut

J Allergy Clin Immunol. 2013 May;131(5):1384-92.e6. doi: 10.1016/j.jaci.2012.10.037. Epub 2012 Dec 11.

Abstract

Background: IgE- and T-cell cross-reactivity contribute to the birch pollen-food syndrome.

Objectives: We performed a comprehensive analysis of T-cell cross-reactivity in primary cell cultures, facilitating the identification of allergen-specific T-cell subpopulations from individual patients.

Methods: Patients with birch pollen allergy and associated food allergy to hazelnuts, carrots, or both were analyzed for IgE cross-reactivity, T-cell responses, and T-cell cross-reactivity to recombinant Bet v 1.0101 (Bet v 1; birch), Cor a 1.0401 (Cor a 1; hazelnut), and Dau c 1.0104 (Dau c 1; carrot). A novel flow cytometry-based method using a 2-step staining process with fluorescent dyes was established to identify subpopulations of cross-reactive T cells.

Results: IgE-binding inhibition tests of individual sera revealed that the vast majority of Cor a 1-reactive IgE was cross-reactive to Bet v 1, whereas Bet v 1-reactive IgE was only partially inhibited by preincubation with Cor a 1. Primary stimulation of T cells with Bet v 1 or Cor a 1 resulted in a significant increase in specific responses to Cor a 1 or Bet v 1 after secondary stimulation, respectively, indicating T-cell cross-reactivity between birch and hazelnut allergens in all patients of the study cohort. Preactivation with Dau c 1 induced less pronounced effects. A novel flow cytometry-based proliferation assay identified a predominant Cor a 1/Bet v 1-cross-reactive T-cell subpopulation within highly Bet v 1/Cor a 1-responsive T cells.

Conclusion: Analysis of primary allergen-specific T cells combined with flow cytometry-based proliferation assays facilitates investigation of allergen-specific T-cell subpopulations in subjects and might be helpful to evaluate the effect of birch-specific immunotherapy on pollen-associated food allergies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Allergens / adverse effects
  • Allergens / immunology
  • Antigens, Plant / adverse effects
  • Antigens, Plant / immunology
  • Antigens, Plant / metabolism
  • Betula / adverse effects
  • Betula / immunology*
  • Case-Control Studies
  • Cells, Cultured
  • Corylus / adverse effects
  • Corylus / immunology*
  • Cross Reactions
  • Daucus carota / adverse effects
  • Daucus carota / immunology
  • Female
  • Food Hypersensitivity / etiology*
  • Food Hypersensitivity / immunology*
  • Humans
  • Immunoglobulin E / metabolism*
  • Male
  • Middle Aged
  • Plant Proteins / adverse effects*
  • Plant Proteins / immunology*
  • Plant Proteins / metabolism
  • Pollen / adverse effects
  • Pollen / immunology
  • T-Lymphocyte Subsets / immunology*
  • Young Adult

Substances

  • Allergens
  • Antigens, Plant
  • Cor a I protein, hazel
  • Plant Proteins
  • Bet v 1 allergen, Betula
  • Immunoglobulin E