Premium
Hypoallergenic mutants of Ole e 1, the major olive pollen allergen, as candidates for allergy vaccines
Author(s) -
Marazuela E. G.,
Rodríguez R.,
Barber D.,
Villalba M.,
Batanero E.
Publication year - 2007
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2006.02632.x
Subject(s) - immunoglobulin e , hypoallergenic , allergen , pichia pastoris , epitope , mutant , basophil , microbiology and biotechnology , biology , mutagenesis , immunology , allergy , antibody , chemistry , recombinant dna , biochemistry , gene
Summary Background The C‐terminal region of Ole e 1, a major allergen from olive pollen, is a dominant IgE‐reactive site and offers a target for site‐directed mutagenesis to produce variants with reduced IgE‐binding capability. Objective To evaluate in vitro and in vivo the immunogenic properties of three engineered derivatives of Ole e 1. Methods One point (Y141A) and two deletion (135Δ10 and 140Δ5) mutants were generated by site‐directed mutagenesis of Ole e 1‐specific cDNA and produced in Pichia pastoris . Ole e 1 mutants were analysed for IgE reactivity by ELISA using sera from olive pollen‐allergic patients. Their allergenicity was also investigated in both a mouse model of allergic sensitization and in basophil activation assays. IgG1 response was assayed by immunoblotting and competitive ELISA. T cell reactivity was evaluated by proliferation assays and cytokine production in splenocyte cultures. Results The 135Δ10 mutant showed the strongest reduction in the IgE‐binding capability of sera from olive pollen‐allergic patients. Rat basophil leukaemia assays identified the deletion mutant 135Δ10 as the variant with the lowest β‐hexosaminidase‐releasing capacity. Furthermore, the same 135Δ10 mutant induced the lowest IgE levels in a BALB/c mouse model of sensitization. All Ole e 1 mutants retained their allergen‐specific T cell reactivity. Immunization of mice with the mutants induced IgG1 antibodies, which cross‐reacted with Ole e 1 and Ole e 1‐like allergens from ash, lilac and privet pollens. The ability of the human IgE to block the binding of anti‐Ole e 1 mutant‐specific mouse IgG1 antibodies to natural Ole e 1 demonstrated that Ole e 1 mutants are able to induce in vivo antibodies reactive to the natural allergen. Conclusion The 135Δ10 mutant with reduced allergenicity, intact T cell reactivity and capacity to induce blocking antibodies could provide a suitable candidate vaccine for efficient and safer therapy of olive pollen allergy.