Birch pollen allergen Bet v 1 binds to and is transported through conjunctival epithelium in allergic patients.
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.
Renkonen
J
J
Transplantation laboratory & Infection Biology Research Program, Haartman Institute, University of Helsinki, Helsinki, Finland.
Mattila
P
P
Lehti
S
S
Mäkinen
J
J
Sormunen
R
R
Tervo
T
T
Paavonen
T
T
Renkonen
R
R
D000328:Adult; D000485:Allergens / Q000493:pharmacokinetics*; D052179:Antigens, Plant; D001692:Biological Transport; D021941:Caveolae / Q000502:physiology; D003228:Conjunctiva / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D021962:Membrane Microdomains / Q000502:physiology; D010940:Plant Proteins / Q000493:pharmacokinetics*; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology*
D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula