Localization of Der f 2 in the gut and faecal pellets of Dermatophagoides farinae

Abstract

Background: House dust mite derived materials are known to be the most potent agent inducing allergic diseases. Localization of Der f 2 was attempted to specify the sites and concentrations of Der f 2 within the mite, which may indicate the importance of secreted materials and nonexcreted body components as allergen sources.

Methods: Serial cryostat sections of embedded live mites and the fecal pellets, collected by brush, were immunoprobed using monoclonal antibody (mAb) 2F38 raised against recombinant (r) Der f 2.

Results: Highest concentrations were found in the anterior midgut, implying that this is the site of Der f 2 synthesis and secretion. Digestive material and defecated fecal pellets were also labeled with mAb.

Conclusions: Our results show that the major allergen, Der f 2, found in the house dust mite D. farinae is derived from the digestive tract, and is concentrated in the feces.