An Engineered Hybrid Protein from Dermatophagoides pteronyssinus Allergens Shows Hypoallergenicity

Abstract

The house dust mite (HDM) Dermatophagoides pteronyssinus is an important risk factor for asthma and rhinitis. Allergen specific immunotherapy that is based on recombinant proteins has been proposed for the safer and more efficient treatment of allergic diseases. The aim of this study was to design and obtain a hybrid protein (DPx4) containing antigenic regions of allergens Der p 1, Der p 2, Der p 7, and Der p 10 from this mite. DPx4 was produced in Escherichia coli and its folding was determined by circular dichroism. Non-denaturing dot-blot, ELISA, basophil activation test, dot blot with monoclonal antibodies, ELISA inhibition, and cysteine protease activity assays were performed. Mice that were immunized with DPx4 were also analyzed. We found that DPx4 had no cysteine protease activity and it showed significantly lower IgE reactivity than Der p 1, Der p 2, and D. pteronyssinus extract. DPx4 induced lower basophil activation than Der p 2 and the allergen extract. Immunized mice produced IgG antibodies that inhibited the binding of allergic patient’s IgE to the allergen extract and induced comparatively higher levels of IL-10 than the extract in peripheral blood mononuclear cells (PBMC) culture. These results suggest that DPx4 has immunological properties that are useful for the development of a mite allergy vaccine.

Der p 2.1 Peptide Abrogates House Dust Mites-Induced Asthma Features in Mice and Humanized Mice by Inhibiting DC-Mediated T Cell Polarization

“…Despite their efficacy in decreasing asthma features, allergen-derived peptides may also be improved. Indeed, Martıńez and colleagues showed that the combination of several Der p allergen-derived peptides exhibits anti-inflammatory properties (52). Moreover, the use of nanoparticles as adjuvants (53) in allergen-derived peptide immunotherapy could potentially improve their ability to polarize innate and adaptive cells into a tolerogenic phenotype.…”

Novel vaccines for allergen-specific immunotherapy

“…For example, basophil activation experiments demonstrated that a hybrid consisting of major allergens from two different aeroallergen sources, Bet v 1 and Phl p 5 induced a much reduced activation, compared with the monomeric forms of the proteins [ 68 ]. Similarly, fusion proteins consisting of four antigenic regions from the major allergens of the mite species D. pteronyssinus showed a significantly reduced IgE reactivity, compared with the individual proteins (Der p 1, Der p 2 and Der p 7) [ 69 ]. Mice immunized with the HDM hybrid protein generated blocking IgG antibodies, thus showing a possibility for a novel HDM vaccine [ 69 ].…”

“…Similarly, fusion proteins consisting of four antigenic regions from the major allergens of the mite species D. pteronyssinus showed a significantly reduced IgE reactivity, compared with the individual proteins (Der p 1, Der p 2 and Der p 7) [ 69 ]. Mice immunized with the HDM hybrid protein generated blocking IgG antibodies, thus showing a possibility for a novel HDM vaccine [ 69 ].…”

Identification and Physicochemical Characterization of a New Allergen from Ascaris lumbricoides

“…Allergen-induced upregulation of CD203c was expressed as the stimulation index (SI), calculated using mean fluorescence intensities (MFI) obtained with stimulated sample (MFI stim) divided by unstimulated sample (MFI control), SI = MFI stim/MFI control. SI ≥ 2.0 was considered positive [ 53 , 54 ].…”