Heat denaturation affects the ProDer p 1 IgE reactivity and downregulates the development of the specific allergic response.
BACKGROUND
Modified allergens with reduced IgE-binding activity represent an elegant approach to circumvent the risk of anaphylactic reactions in allergen-specific immunotherapy.


OBJECTIVE
The current work investigated the effect of heat denaturation on the allergenic properties of recombinant ProDer p 1, a precursor form of the major house dust mite allergen Der p 1.


METHODS
The IgE reactivity was estimated by direct and competition ELISA. The immunogenicity of heat-denatured ProDer p 1 was evaluated in naive and Der p 1-allergic mice.


RESULTS
Heat denaturation in reducing conditions drastically reduced the in vitro ProDer p 1 IgE reactivity toward human allergic sera. In naive mice, heat-denatured ProDer p 1 generated mixed T(H)1-T(H)2 responses characterized by the absence of specific IgE with concomitant rise in specific IgG2a titers and the presence of IL-5 and IFN-gamma in splenocyte cultures. In contrast, natural Der p 1 or native ProDer p 1 induced typical strict T(H)2-biased allergic responses with strong IgG1 and IgE titers, whereas spleen cells exhibited only high IL-5 secretion. Moreover, native or heat-denatured ProDer p 1 vaccinations prevented airway eosinophil infiltrations after challenge. Although native or heat-treated ProDer p 1 adjuvanted with SBAS1b induced mixed T(H)1-T(H)2 responses in allergic mice, heat-denatured ProDer p 1, compared with native ProDer p 1, proved to be more effective in redirecting the T(H)2-allergic response toward T(H)1.


CONCLUSIONS
Taken together, our results suggest that variants of Der p 1 with reduced IgE-binding reactivity could represent hypoallergenic molecules suitable for allergen-specific immunotherapy.
Magi
Mauro
M
Service de Génétique Appliquée, Institut de Biologie et de Médecine Moléculaires, Université Libre de Bruxelles, Gosselies, Belgium.
Garcia
Lida
L
Vandenbranden
Michel
M
Palmantier
Rémi
R
Jacquet
Alain
A
D000818:Animals; D039741:Antigens, Dermatophagoides / Q000008:administration & dosage / Q000009:adverse effects* / Q000378:metabolism; D060829:Arthropod Proteins; D003546:Cysteine Endopeptidases; D015536:Down-Regulation; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000503:physiopathology*; D007114:Immunization; D007073:Immunoglobulin E / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011489:Protein Denaturation; D011498:Protein Precursors / Q000008:administration & dosage / Q000009:adverse effects* / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D011498:Protein Precursors; D007073:Immunoglobulin E; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1