title: Phenotypic analysis of perennial airborne allergen-specific CD4+ T cells in atopic and non-atopic individuals.
abstract: BACKGROUND
  Accumulating evidence suggests that T cells play an important role in the pathogenesis of atopic dermatitis (AD); yet, little is known of the differentiation status of CD4+ T cells specific for common environmental allergens, such as the major cat allergen, Fel d 1.
  
  
  OBJECTIVE
  To determine the frequency, differentiation phenotype and function of circulating Fel d 1-specific CD4+ T cells in adult individuals with severe persistent AD in comparison with healthy controls.
  
  
  METHODS
  Using HLA class II tetrameric complexes based on a HLA-DPB1*0401-restricted Fel d 1 epitope, ex vivo and cultured T cell frequency and phenotype were analysed in individuals with AD and healthy controls. Cytokine secretion was measured by ex vivo and cultured IL-4 and IFN-γ ELISpots.
  
  
  RESULTS
  Ex vivo Fel d 1-specific DPB1*0401-restricted CD4+ T cells in both atopics and non-atopics express high levels of CCR7, CD62L, CD27 and CD28, placing the cells largely within the central memory subgroup. However, the functional phenotype was distinct, with greater IL-4 production from the cells derived from atopics, which correlated with disease severity.
  
  
  CONCLUSIONS
  Circulating Fel d 1-specific DPB1*0401-restricted CD4+ T cells in both atopic and non-atopic donors maintain a central memory phenotype; however in atopics, the cells had greater Th2 effector function, compatible with a disease model of altered antigen delivery in atopic individuals.
authors: MRC Human Immunology Unit, University of Oxford, Weatherall Institute of Molecular Medicine, Oxford, UK.
authors: L R
authors: LR
authors: Crack
authors: H W
authors: HW
authors: Chan
authors: T
authors: T
authors: McPherson
authors: G S
authors: GS
authors: Ogg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002415:Cats; D002460:Cell Line; D003876:Dermatitis, Atopic / Q000276:immunology / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D059868:HLA-DP beta-Chains / Q000276:immunology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology* / Q000378:metabolism; D007073:Immunoglobulin E / Q000276:immunology; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000276:immunology; D010641:Phenotype; D055503:Protein Multimerization / Q000276:immunology; D055815:Young Adult
chemical_list: D000485:Allergens; D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D059868:HLA-DP beta-Chains; C071170:HLA-DPB1 antigen; D010455:Peptides; D007073:Immunoglobulin E; C059296:Fel d 1 protein, Felis domesticus