T-cell epitopes of the major peach allergen, Pru p 3: Identification and differential T-cell response of peach-allergic and non-allergic subjects

Mol Immunol. 2009 Feb;46(4):722-8. doi: 10.1016/j.molimm.2008.10.018. Epub 2008 Dec 2.

Abstract

Lipid transfer proteins (LTPs), particularly peach Pru p 3, are the most relevant plant food allergens in the South of Europe, and, therefore, their allergic properties have been extensively studied. However, neither T-cell epitopes nor their effect on the patients' T-cell response has been investigated in any member of the LTP panallergen family. The objective of the present study was to map the major T-cell epitopes of Pru p 3, as well as to evaluate their induced T-cell response in peach-allergic versus control subjects. Thus, peripheral blood mononuclear cells (PBMCs) from 18 peach-allergic patients and Pru p 3-specific T-cell lines (TCLs) from 9 of them were cultured with Pru p 3 and with a panel of 17 derived peptides (10-mer overlapping in 5 amino acids representing the full sequence of Pru p 3). Proliferation in 5-day assays was carried out via tritiated-thymidine incorporation, while IL4 and IFNgamma production was assessed via sandwich enzyme-linked immunosorbent tests (ELISA) of TCL culture supernatants. The results were compared to those obtained from 10 non-peach allergic control volunteers. Two consecutive peptides showed the highest activation capacity. About 74% of PBMCs and TCLs recognized them, forming a single T-epitope: Pru p 3(65-80). Additionally, other specific T-cell epitopes were observed. Pru p 3(25-35) was detected by more than 60% of TCLs from peach-allergic patients, and Pru p 3(45-55) only activated PBMCs from control subjects. Interestingly, TCLs from patients were associated with a Th2-type, whereas control TCLs presented a Th1-type cytokine response. The major immunogenic T-cell epitope identified in Pru p 3, Pru p 3(65-80), is a good candidate to develop new vaccines for hypersensitivity reactions associated with LTP allergens from Rosaceae fruits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / chemistry
  • Allergens / immunology*
  • Amino Acid Sequence
  • Antigens, Plant / immunology*
  • Antigens, Plant / metabolism
  • Epitope Mapping*
  • Epitopes, T-Lymphocyte / immunology*
  • Epitopes, T-Lymphocyte / metabolism
  • Food Hypersensitivity / immunology*
  • Food Hypersensitivity / metabolism
  • Humans
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / immunology
  • Interleukin-4 / biosynthesis
  • Interleukin-4 / immunology
  • Molecular Sequence Data
  • Peptides / immunology
  • Peptides / metabolism
  • Plant Proteins
  • Protein Conformation
  • Prunus / immunology*
  • Prunus / metabolism
  • Vaccines / chemistry
  • Vaccines / immunology

Substances

  • Allergens
  • Antigens, Plant
  • Epitopes, T-Lymphocyte
  • IL4 protein, human
  • Peptides
  • Plant Proteins
  • Pru p 3 allergen
  • Vaccines
  • Interleukin-4
  • Interferon-gamma