Birch pollen allergen Bet v 1 binds to and is transported through conjunctival epithelium in allergic patients

Allergy. 2009 Jun;64(6):868-75. doi: 10.1111/j.1398-9995.2008.01919.x. Epub 2009 Jan 15.

Abstract

Background: Previous work in type-I pollen allergies has mainly focused on lymphocytes and immune responses. Here, we begin to analyse with a systems biology view the differences in conjunctival epithelium obtained from healthy and allergic subjects.

Methods: Transcriptomics analysis combined with light and electron microscopic analysis of birch pollen allergen Bet v 1 located within conjunctival epithelial cells and tissues from birch allergic subjects and healthy controls was carried out.

Results: Bet v 1 pollen allergen bound to conjunctival epithelial cells within minutes after the exposure even during the nonsymptomatic winter season only in allergic, but not in healthy individuals. Light- and electron microscopy showed that Bet v 1 was transported through the epithelium within lipid rafts/caveolae and reached mast cells only in allergic patients, but not in healthy individuals. Transcriptomics yielded 22 putative receptors expressed at higher levels in allergic epithelium compared with healthy specimens. A literature search indicated that out of these receptors, eight (i.e. 37%) were associated with lipid rafts/caveolae, which suggested again that Bet v 1 transport is lipid raft/caveola-dependent.

Conclusions: We show a clear difference in the binding and uptake of Bet v 1 allergen by conjunctival epithelial cells in allergic vs healthy subjects and several putative lipid raft/caveolar receptors were identified, which could mediate or be co-transported with this entry. The application of discovery driven methodologies on human conjunctival epithelial cells and tissues can provide new hypotheses worth a further analysis to the molecular mechanisms of a complex multifactorial disease such as type-I birch pollen allergy.

MeSH terms

  • Adult
  • Allergens / pharmacokinetics*
  • Antigens, Plant
  • Biological Transport
  • Caveolae / physiology
  • Conjunctiva / metabolism*
  • Epithelium / metabolism
  • Female
  • Gene Expression Profiling
  • Humans
  • Male
  • Membrane Microdomains / physiology
  • Plant Proteins / pharmacokinetics*
  • Rhinitis, Allergic, Seasonal / etiology*

Substances

  • Allergens
  • Antigens, Plant
  • Plant Proteins
  • Bet v 1 allergen, Betula