Localization of a major allergen, Der p 2, in the gut and faecal pellets of Dermatophagoides pteronyssinus

Background The house dust mite Dermatophagoides ptronyssinus is one of the most significant indoor sensitizing agents of allergy. Allergen localizatio n may indicate the importance of secreted materials, faeces, and nonexcrete d mite body components as allergen sources. Objective This study attempted to localize the sites and concentrations of Der p 2 in the cryostat sections of D. pteronyssinus using antirecombinant Der p 2 monoclonal antibody. Methods Male and female mites and mite faeces collected separately from bot h sexes were used. Live mites were embedded and serial cryostat sections fo r light microscopy were performed. Anti-recombinant Der p 2 monoclonal anti body previously produced by the authors was used. For immunoprobing, mite c ryostat sections were incubated in the following antibody-containing soluti ons: monoclonal antibody against Der p 2 was initially applied to the secti ons and fluorescent isothiocyanate conjugated antimouse immunoglobulin G wa s reacted as the secondary antibody. The faecal pellets were treated the sa me as described above. Results Immunofluorescent probing of cryostat sections with the monoclonal antibody showed labelling of the gut lining,,out contents and defecated fae cal pellets. No other internal organs were identified as positively labelle d. Conclusion This study suggested that a major allergen, Der p 2, found in th e house dust mite D. pteronyssinus is derived from the digestive tract and concentrated in the faeces.