title: T cell responses to recombinant isoforms, synthetic peptides and a mutant variant of Lep d 2, a major allergen from the dust mite Lepidoglyphus destructor.
abstract: BACKGROUND
  The dust mite Lepidoglyphus destructor is an important cause of allergic reactions to dust, especially in farming environments. Two isoforms, recombinant (r)Lep d 2.01 and rLep d 2.02, of the major allergen Lep d 2, have previously been expressed as recombinant proteins. These isoforms differ 10.4% at the amino acid level. Furthermore, a mutant form of Lep d 2.01 (rLep d 2.6Cys) with a highly reduced IgE reactivity, has also been produced.
  
  
  OBJECTIVE
  To investigate the T cell responses to the recombinant isoforms of Lep d 2, the Lep d 2.6Cys mutant and peptides of Lep d 2, in allergic and non-allergic individuals.
  
  
  METHODS
  Peripheral blood mononuclear cells from 18 allergic and 16 non-allergic individuals were stimulated with the different antigens and the proliferative responses were measured. The cytokine production (interleukin (IL)-4, IL-5 and interferon (IFN)-gamma) were measured by ELISA.
  
  
  RESULTS
  Higher T cell proliferation was measured to isoform 01 than to 02 in 28/34 subjects. The responses to rLep d 2.6Cys were lower than to isoform 01 in most subjects, but higher than to Lep d 2.02. Two immuno-dominant peptides, corresponding to amino acid residue 11-25 and 61-75 were identified. The atopic subjects produced significantly lower IFN-gamma in response to Lep d 2.01 as compared to the non-atopics.
  
  
  CONCLUSIONS
  There was a significant difference in T cell response between the two isoforms of rLep d 2. The hypoallergenic mutant rLep d 2.6Cys was able to evoke a T cell response with a magnitude which is between the two isoforms. Amino acid residue 11-25 and 61-75 are the most frequently recognized parts of Lep d 2 and are likely to contain the immuno-dominant T cell epitopes.
authors.affiliation: Department of Medicine, Unit of Clinical Immunology & Allergy, Karolinska Hospital and Institutet, Stockholm, Sweden. tove.eriksson@ks.se
authors.forename: T L
authors.initials: TL
authors.lastname: Eriksson
authors.forename: G
authors.initials: G
authors.lastname: Gafvelin
authors.forename: L H
authors.initials: LH
authors.lastname: Elfman
authors.forename: C
authors.initials: C
authors.lastname: Johansson
authors.forename: M
authors.initials: M
authors.lastname: Van Hage-Hamsten
authors.forename: S
authors.initials: S
authors.lastname: Olsson
mesh_terms: D000328:Adult; D000383:Agriculture; D000485:Allergens / Q000009:adverse effects* / Q000276:immunology; D000818:Animals; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D014644:Genetic Variation; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000097:blood / Q000276:immunology; D008875:Middle Aged; D008925:Mites / Q000276:immunology; D010455:Peptides / Q000009:adverse effects* / Q000276:immunology*; D020033:Protein Isoforms / Q000276:immunology; D011506:Proteins / Q000235:genetics*; D011994:Recombinant Proteins / Q000009:adverse effects* / Q000276:immunology*; D013548:Sweden / Q000453:epidemiology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000485:Allergens; D016207:Cytokines; C090039:Lep d I allergen; D010455:Peptides; D020033:Protein Isoforms; D011506:Proteins; D011994:Recombinant Proteins