EXPRESSION OF THE HOUSE-DUST MITE ALLERGEN DER-P-2 IN THE BAKERS-YEAST SACCHAROMYCES-CEREVISIAE

Background and Results The major house dust mite allergen Der p 2 was expressed as a recombinant mature protein in the baker's yeast Sacchar omyces cerevisiae. The yeast produces the protein fused to the inverta se signal peptide, leading to the secretion of Der p 2 as a soluble pr otein into the culture medium. The signal peptide is hereby cleaved of f, resulting in a mature allergen. In this system Der p 2 was produced in 7.6(+/- 2.9) mg/L growth culture. Purification of the recombinant allergen was achieved by a single gel filtration step, resulting in a purity greater than or equal to 95%. The yeast-derived Der p 2 was alm ost indistinguishable from natural Der p 2 with respect to IgE-reactiv ity and binding to the majority of Der p 2 specific MoAbs - as was sho wn in RAST analysis (n = 168) and a sandwich ELISA and RIA analysis, r espectively. Recombinant and natural Der p 2 also showed similar biolo gical activity in histamine release assays (n = 4). Conclusion An expr ession system for Der p 2 was developed that enables the production of a soluble allergen in the culture supernatant with immunological char acteristics similar to the natural allergen. In addition, yeast offers the advantage of the absence of endotoxin in comparison to E. coli. T his might facilitate acceptance of recombinant allergens for in vivo a pplications as immunotherapy or skin-prick testing.