One reason for the development of allergy may be malfunction of the respiratory epithelium, which allows allergens to bind to, enter and travel through the epithelium. Two studies by Finnish research groups on this subject have recently been published in two international biomedical journals (1) Allergy, and (2) Journal of Allergy and Clinical Immunology.
Research on the mechanisms of allergy has focused on the understanding of aberrant immunoresponses. Only lately the role of epithelium as the first line of defense against allergens has been realized. So far, we do not know why and how allergens are transported through the epithelium.
The research groups of the Helsinki University and Helsinki University Central Hospital in collaboration with several other Finnish research groups aimed to clarify what happens in the epithelium immediately after allergen exposure, before the allergic reaction develops. They used birch pollen allergen (Bet v 1) exposure and showed that this allergen binds to, enters and travels through conjunctival and nasal epithelium of allergic patients but not of healthy subjects within one minute after the exposure. An allergic reaction developed when the allergen reached mast cells under the basement membrane.
During the research it became evident that during spring, in allergic patients the birch pollen allergen Bet v 1 changed the expression of hundreds of genes of the nasal epithelium compared to samples taken during winter; and of these genes several were connected with protein transport and regulation of cytoskeleton. An astonishing finding was that the immune response of in healthy controls to pollen exposure was strong, and hundreds of genes changed their expression during winter and spring; however, many of these genes were related to the function of the immune response.
"We were able to describe a mechanism whereby birch pollen allergen Bet v 1 travels through the epithelium of a
|Contact: Professor Risto Renkonen|
University of Helsinki