Characterization of house dust for peptidase activity from fungal and mite allergens using monoclonal antibodies and specific peptidase assays

Abstract

Rationale Exposure to active peptidase enzymes is an occupational hazard. Active peptidases are known to be a major concern in the pathology of allergies in airways of the lungs. The study set out to detect and characterize domestic dust samples for house dust mite ( Dermatophagoides pteronyssinus) and fungal ( Aspergillus fumigatus) allergens and the contribution of peptidase activity from these allergens. Methods Domestic dust samples were collected and extracted in a Tris buffer at pH 7.5. Extracts were subsequently assessed by commercially available ELISA and a peptidase activity assay using peptide pNA substrates. These were compared to the peptidase activities and allergen contents of standard extracts of Dermatophagoides pteronyssinus and Aspergillus fumigatus. Samples were further characterized by screening the extracts with a variety of peptide substrates and peptidase inhibitors. Results ELISA results demonstrated the presence of allergens from Dermatophagoides pteronyssinus and Aspergillus fumigatus in a variety of the dust samples that were tested. Further characterization of these samples with a panel of peptide pNA substrates and peptidase inhibitors demonstrated peptidase activities can contributed to fungal and dust mite allergens. The significance of peptidase activities from both Dermatophagoides pteronyssinus and Aspergillus fumigatus allergens will be discussed. Conclusions Presence of both house dust mite and fungal allergens and peptidases were demonstrated in domestic dust samples using both mABs and specific peptidase action. Exposure to these peptidases can be a health hazard and contribute to allergic conditions.