title: Ara h 1 CD4+ T cell epitope-based peptides: candidates for a peanut allergy therapeutic.
abstract: BACKGROUND
  Peanut allergy is a life-threatening condition; there is currently no cure. While whole allergen extracts are used for specific immunotherapy for many allergies, they can cause severe reactions and even fatalities in peanut allergy.
  
  
  OBJECTIVE
  To identify short, HLA-degenerate CD4(+) T cell epitope-based peptides of the major peanut allergen Ara h 1 that target allergen-specific T cells without causing IgE-mediated inflammatory cell activation, as candidates for safe peanut-specific immunotherapy.
  
  
  METHODS
  Ara h 1-specific CD4(+) T cell lines (TCL) were generated from peripheral blood mononuclear cells (PBMC) of peanut-allergic subjects using CFSE-based methodology. T cell epitopes were identified using CFSE and thymidine-based proliferation assays. Epitope HLA-restriction was investigated using blocking antibodies, HLA-genotyping and epitope prediction algorithms. Functional peanut-specific IgE reactivity to peptides was assessed by basophil activation assay.
  
  
  RESULTS
  A total of 145 Ara h 1-specific TCL were generated from 18 HLA-diverse peanut-allergic subjects. The TCL recognized 20-mer peptides throughout Ara h 1. Nine 20-mers containing the most frequently recognized epitopes were selected and their recognition confirmed in 18 additional peanut-allergic subjects. Ten core epitopes were mapped within these 20-mers. These were HLA-DQ and/or HLA-DR restricted, with each presented on at least two different HLA-molecules. Seven short (≤ 20 aa) non-basophil-reactive peptides encompassing all core epitopes were designed and validated in peanut-allergic donor PBMC T cell assays.
  
  
  CONCLUSIONS
  Short CD4(+) T cell epitope-based Ara h 1 peptides were identified as novel candidates for a safe, T cell targeted peanut-specific immunotherapy for HLA-diverse populations.
authors.affiliation: Department of Immunology, Monash University, Melbourne, Vic., Australia.
authors.forename: S R
authors.initials: SR
authors.lastname: Prickett
authors.forename: A L
authors.initials: AL
authors.lastname: Voskamp
authors.forename: T
authors.initials: T
authors.lastname: Phan
authors.forename: A
authors.initials: A
authors.lastname: Dacumos-Hill
authors.forename: S I
authors.initials: SI
authors.lastname: Mannering
authors.forename: J M
authors.initials: JM
authors.lastname: Rolland
authors.forename: R E
authors.initials: RE
authors.lastname: O'Hehir
mesh_terms: D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000276:immunology*; D001491:Basophils / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D021183:Peanut Hypersensitivity / Q000276:immunology*; D010455:Peptides / Q000737:chemistry / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology*
chemical_list: D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D000949:Histocompatibility Antigens Class II; D008565:Membrane Proteins; D010455:Peptides; D010940:Plant Proteins; D007073:Immunoglobulin E