title: Allergen interactions with epithelium.
abstract: OBJECTIVE
  Allergies are a global health problem with rapidly increasing prevalence but still lacking pathogenetic knowledge or optimal treatment. The objective is to add to the conventional thinking that allergies are caused by overactive, mainly T-cell-mediated, immunological responses and thus to raise the putative role of altered epithelial functions.
  
  
  RESULTS
  Birch pollen allergen was rapidly and actively transported through the respiratory epithelium via caveolar-dependent mechanisms only in patients allergic to birch pollen but not their healthy controls. Transcriptomic analyses showed that whereas healthy individuals raised a strong epithelial response after intranasal allergen challenge, the allergic patients had a reduced response. Thus allergies could also be due to hyporeactive responses on the epithelial level.
  
  
  CONCLUSIONS
  Epithelium has emerged as an active and complex organ with mechanical, biochemical and immunological functions. The increasing awareness that epithelium interacts actively with allergens might provide new targets for the prevention and management of allergy.
authors.affiliation: Transplantation Laboratory & Infection Biology Research Program, Haartman Institute, University of Helsinki & HUSLAB, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Sanna
authors.initials: S
authors.lastname: Toppila-Salmi
authors.forename: Jutta
authors.initials: J
authors.lastname: Renkonen
authors.forename: Sakari
authors.initials: S
authors.lastname: Joenväärä
authors.forename: Pirkko
authors.initials: P
authors.lastname: Mattila
authors.forename: Risto
authors.initials: R
authors.lastname: Renkonen
mesh_terms: D000485:Allergens / Q000009:adverse effects*; D029662:Betula / Q000009:adverse effects / Q000276:immunology; D001693:Biological Transport, Active; D016207:Cytokines / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D021962:Membrane Microdomains / Q000276:immunology; D011058:Pollen / Q000009:adverse effects / Q000276:immunology; D020545:Respiratory Mucosa / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology / Q000276:immunology*
chemical_list: D000485:Allergens; D016207:Cytokines