Non-allergic beekeepers, who are exposed to multiple honeybee stings owing to their profession, represent a suitable model for high-dose allergen exposure and still a healthy immune response. These beekeepers have 1000-times higher specific IgG4 versus specific IgE ratio compared with allergic individuals  The level of specific IgG4 primarily reflects exposure. 

In beekeepers, the amount of bee venom (BV) specific serum IgG4 produced correlates with the number of annual stings and with the number of years spent in bee-keeping. High dose of exposure appears to induce clinical tolerance: 45% of beekeepers who were stung <25 times a year had a history of systemic sting reactions, compared with no allergy in those with >200 stings per year  

In healthy individuals, Tr1 cells represent the dominant subset for common environmental allergens, whereas a high frequency of allergen-specific IL-4-secreting T cells is found in allergic individuals. Interestingly, the same features of peripheral tolerance were found in the T cells of healthy beekeepers who had previously been stung by high numbers of bees. 

Akdis, M. (2006). Healthy immune response to allergens: T regulatory cells and more. Current opinion in immunology, 18(6), 738-744.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html