title: IL-5 production by resident mucosal allergen-specific T cells in an explant model of allergic rhinitis.
abstract: BACKGROUND
  Seasonal allergic rhinitis is a chronic inflammation in the nasal mucosa triggered by inhaled aeroallergens. The inflammatory reaction is controlled by allergen-specific T cells, but where and how these T cells become activated is not fully understood.
  
  
  OBJECTIVE
  We wanted to determine whether allergen-specific T-helper (Th) 2 cells are residing in the nasal mucosa under steady-state conditions outside of the pollen season and, if so, whether these cells are activated locally in response to allergen challenge.
  
  
  METHODS
  Mucosal biopsies from the lower turbinate were obtained out of season from patients with either birch- or grass-pollen-allergic rhinitis and from healthy controls. Cultured explant samples were challenged with relevant pollen extract or with a mix of overlapping 20-mer peptides derived from the sequence of the major birch allergen, Betula verrucosa (Bet v) 1. After 24 h, culture medium was harvested for multiplex cytokine and tryptase analysis.
  
  
  RESULTS
  Significant amounts of interleukin (IL)-5 were secreted from resident cells in response to ex vivo allergen challenge in the allergic group only. No increase was observed for the other cytokines measured. Production of IL-5 in response to both extract and the Bet v1-derived peptide mix strongly suggested that T cells were a major source of IL-5.
  
  
  CONCLUSIONS
  Our explant model indicated that local presentation of antigen to resident allergen-specific Th2 cells is the early event in the pathogenesis of allergic rhinitis. These findings identify possible cellular targets for anti-inflammatory treatment.
authors.affiliation: Department of Pathology and Centre for Immune Regulation, Oslo University Hospital and University of Oslo, Oslo, Norway.|Department of Otorhinolaryngology, Akershus University Hospital, Lørenskog, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Skrindo
authors.affiliation: Department of Pathology and Centre for Immune Regulation, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: C
authors.initials: C
authors.lastname: Ballke
authors.affiliation: Department of Otolaryngology, Lovisenberg Diakonale Hospital, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Gran
authors.affiliation: Department of Pathology and Centre for Immune Regulation, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: F-E
authors.initials: FE
authors.lastname: Johansen
authors.affiliation: Department of Pathology and Centre for Immune Regulation, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: E S
authors.initials: ES
authors.lastname: Baekkevold
authors.affiliation: Department of Pathology and Centre for Immune Regulation, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: F L
authors.initials: FL
authors.lastname: Jahnsen
mesh_terms: D000293:Adolescent; D000328:Adult; D052179:Antigens, Plant / Q000276:immunology*; D002648:Child; D005260:Female; D006801:Humans; D015848:Interleukin-5 / Q000276:immunology*; D008297:Male; D018448:Models, Immunological; D009297:Nasal Mucosa / Q000276:immunology* / Q000473:pathology; D065631:Rhinitis, Allergic / Q000276:immunology* / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology* / Q000473:pathology; D046509:Tissue Culture Techniques
chemical_list: D052179:Antigens, Plant; C508599:IL5 protein, human; D015848:Interleukin-5; C061312:Bet v 1 allergen, Betula
keywords: T cells; airway mucosa; allergens; allergic disease