Novel Method for the Purification of House Dust Mite Allergen Der p 1 and Its Use in Structure-Based Chemical Design of Novel Inhibitors.

House dust mites are globally significant triggers of allergic disease. Notable among their extensive repertoire of allergens are the Group 1 cysteine peptidase allergens which function as digestive enzymes in house dust mites. Compelling evidence suggests that the proteolytic activity of these molecules plays a key role in the development and maintenance of allergic diseases through the activation of innate immune mechanisms which exploit genetic predispositions to allergy. Growing interest in this area creates a requirement for high-quality purified protein, whether natural or recombinantly expressed. It has also identified these allergens as therapeutic targets for a novel approach to allergy treatment through modulation of innate immune responses. The purpose of this chapter is to describe a new method for the purification of Der p 1 and use of the protein produced in a screening assay designed for the discovery of novel inhibitors of Group 1 house dust mite allergens.

Zingiber cassumunar ROXb. and its active constituent inhibit MMP-9 direct activation by house dust mite allergens and MMP-9 expression in PMA-stimulated human airway epithelial cells.

BACKGROUND: House dust mite (HDM) induced matrix metalloproteinase (MMP)-9 plays a role in asthma. Zingiber cassumunar Roxb. (Phlai in Thai) has been used in folk medicine for asthma treatment. OBJECTIVE: We investigated effects of Phlai and its constituent (E)-4-(3',4'-dimethoxyphenyl)but-3-en-1-ol (compound D) on the cleavage of pro- MMP-9 by HDM. The effects of these compounds on phorbol 12-myristate 13-acetate (PMA)- induced MMP-9 gene and protein expression in airway epithelial cells (NCI-H292) were also investigated. METHODS: Pro-MMP-9 was directly activated in vitro with HDM in the presence or absence of the ethanolic extracts of Phlai or compound D for 1 hour. The amount of activated MMP-9 was determined using gelatin zymography. To study the cellular response of Phlai, NCI-H292 cells were pretreated with crude Phlai extracts or compound D for 2 hours, and then the cells were stimulated with PMA for 48 hours. The mRNA RT-PCR and Western blotting, respectively. MMP-9 activity was determined by gelatin zymography. RESULTS: Crude Phlai extracts (0.25 - 2.0 mg/ml) and compound D (0.5 - 4.0 mg/ml) inhibited pro- MMP-9 cleavage by HDM. Furthermore, crude Phlai extracts (100 mg/ml) and compound D, at concentrations of 50 and 100 mg/ml, attenuated the PMA-induced MMP-9 gene and expression in NCI-H292 cells. These compound also suppressed MMP-9 release from PMA-induced NCI-H292 cells. CONCLUSION: The crude ethanolic extract of Z. cassumunar and its active constituent compound D inhibited the cleavage of pro-MMP-9 by HDM. They also inhibited PMA-induced MMP-9 gene and protein synthesis in human airway epithelial cells.