title: Unique and cross-reactive T cell epitope peptides of the major Bahia grass pollen allergen, Pas n 1.
abstract: BACKGROUND
  Bahia grass pollen (BaGP) is a major cause of allergic rhinitis. Subcutaneous allergen-specific immunotherapy is effective for grass pollen allergy, but is unsuitable for patients with moderate to severe asthma due to the risk of anaphylaxis. T cell-reactive but IgE nonreactive peptides provide a safer treatment option. This study aimed to identify and characterize dominant CD4(+) T cell epitope peptides of the major BaGP allergen, Pas n 1.
  
  
  METHODS
  Pas n 1-specific T cell lines generated from the peripheral blood of BaGP-allergic subjects were tested for proliferative and cytokine response to overlapping 20-mer Pas n 1 peptides. Cross-reactivity to homologous peptides from Lol p 1 and Cyn d 1 of Ryegrass and Bermuda grass pollen, respectively, was assessed using Pas n 1 peptide-specific T cell clones. MHC class II restriction of Pas n 1 peptide T cell recognition was determined by HLA blocking assays and peptide IgE reactivity tested by dot blotting.
  
  
  RESULTS
  Three Pas n 1 peptides showed dominant T cell reactivity; 15 of 18 (83%) patients responded to one or more of these peptides. T cell clones specific for dominant Pas n 1 peptides showed evidence of species-specific T cell reactivity as well as cross-reactivity with other group 1 grass pollen allergens. The dominant Pas n 1 T cell epitope peptides showed HLA binding diversity and were non-IgE reactive.
  
  
  CONCLUSIONS
  The immunodominant T cell-reactive Pas n 1 peptides are candidates for safe immunotherapy for individuals, including those with asthma, who are allergic to Bahia and possibly other grass pollens.
authors: Department of Immunology, Monash University, Melbourne, Vic., Australia.
authors: Tamara
authors: T
authors: Etto
authors: Carmela
authors: C
authors: de Boer
authors: Sara
authors: S
authors: Prickett
authors: Leanne M
authors: LM
authors: Gardner
authors: Astrid
authors: A
authors: Voskamp
authors: Janet M
authors: JM
authors: Davies
authors: Robyn E
authors: RE
authors: O'Hehir
authors: Jennifer M
authors: JM
authors: Rolland
mesh_terms: D000328:Adult; D000485:Allergens / Q000737:chemistry / Q000276:immunology*; D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000737:chemistry / Q000276:immunology; D001249:Asthma / Q000150:complications / Q000188:drug therapy / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D002999:Clone Cells; D003429:Cross Reactions; D031744:Cynodon / Q000737:chemistry / Q000276:immunology; D003888:Desensitization, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008129:Lolium / Q000737:chemistry / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology* / Q000627:therapeutic use; D031781:Paspalum / Q000737:chemistry / Q000276:immunology*; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology*; D011058:Pollen / Q000737:chemistry / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000188:drug therapy / Q000276:immunology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D018984:Epitopes, T-Lymphocyte; D009842:Oligopeptides; C577590:Pas n 1 allergen, Bahia grass; D010940:Plant Proteins; D007073:Immunoglobulin E