title: Pru p 3, the nonspecific lipid transfer protein from peach, dominates the immune response to its homolog in hazelnut.
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 3(61-75) . 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.
authors.affiliation: Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.
authors.forename: V
authors.initials: V
authors.lastname: Schulten
authors.forename: B
authors.initials: B
authors.lastname: Nagl
authors.forename: E
authors.initials: E
authors.lastname: Scala
authors.forename: M L
authors.initials: ML
authors.lastname: Bernardi
authors.forename: A
authors.initials: A
authors.lastname: Mari
authors.forename: M A
authors.initials: MA
authors.lastname: Ciardiello
authors.forename: I
authors.initials: I
authors.lastname: Lauer
authors.forename: S
authors.initials: S
authors.lastname: Scheurer
authors.forename: P
authors.initials: P
authors.lastname: Briza
authors.forename: A
authors.initials: A
authors.lastname: Jürets
authors.forename: F
authors.initials: F
authors.lastname: Ferreira
authors.forename: B
authors.initials: B
authors.lastname: Jahn-Schmid
authors.forename: G F
authors.initials: GF
authors.lastname: Fischer
authors.forename: B
authors.initials: B
authors.lastname: Bohle
mesh_terms: D000485:Allergens / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology*; D031211:Corylus / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology*; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D008247:Lysosomes / Q000276:immunology; D010940:Plant Proteins; D027861:Prunus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C527352:Cor a 8 allergen, Corylus avellana; D010940:Plant Proteins; C463181:Pru p 3 allergen