MOLECULAR CHARACTERIZATION OF ANTIBODIES WITH THERAPEUTIC POTENTIAL FOR BIRCH POLLINOSIS AND RELATED FOOD ALLERGY
Abstract
In addition to pollinosis the majority of birch pollen-allergic individuals develops food allergy, most commonly to apple. Birch pollen-related apple allergy is the most abundant food allergy in adolescent/adult individuals and also affects children. Although this IgE-mediated hypersensitivity reaction is a consequence of birch pollen allergy, effective treatment of the latter often fails to reduce the related food allergy. We seek for efficient and safe strategies for concomitant treatment of both birch pollinosis and related food allergies. In The FWF-funded clinical trial KLI96 we found that sublingual administration of the recombinant major apple allergen Mal d 1 induced tolerance to apples in birch pollen-allergic individuals with apple allergy. The clinical success was associated with the induction of Mal d 1-specific IgG4 antibodies that prevented IgE-mediated allergic reactions. In this project, we intend to identify the molecular and immunological requirements for functional IgE-blocking ability. In particular, we will identify the features of antibodies with cross-blocking activity, i.e. antibodies that block IgE-binding to both major allergens. Superior expertise in allergology, molecular and structural biology will be combined with cutting-edge technologies to delineate and compare the biophysical and immunological characteristics of recombinant Mal d 1-specific IgG4 antibodies. Combinatorial antibody fragment libraries using yeast surface display will be constructed from individuals who tolerated apples after sublingual treatment with Mal d 1. Mal d 1-specific antibodies isolated from these libraries will be produced in recombinant form and their stability and binding affinity will be analysed by differential scanning calorimetry, circular dichroism, multi-angle light scattering, surface plasmon resonance, and isothermal titration calorimetry. Antibodies will also be assessed for their binding-sites on the allergens, their cross-reactivity with the major birch pollen allergen and their ability to block allergic reactions in vitro and in a humanized mouse model. The knowledge of the binding sites of blocking antibodies will allow the rational design of recombinant allergen variants that promote the induction of functional blocking antibodies during active immunotherapy. Recombinant antibodies with cross-blocking activity represent candidate vaccines for passive immunotherapy. Thus, this project will develop two contrary but complementary approaches to concomitantly treat birch pollen allergy and birch pollen-related food allergies. Moreover, the insights gained in this project will improve our understanding of the immune mechanisms involved in successful allergy treatment and may be applied to other disorders caused by immunological cross-reactivity.
keywords active immunotherapy birch pollinosis and related food allergy blocking IgE binding Mal d 1-specific IgG4 Antibodies
Publikationen
Project staff
Gordana Wozniak-Knopp
Dipl.-Biol. Dr.rer.nat. Gordana Wozniak-Knopp
gordana.wozniak@boku.ac.at
Tel: +43 1 47654-79868
BOKU Project Leader
01.01.2020 - 30.06.2024
BOKU partners
External partners
Medical University of Vienna
Prof. Dr. Barbara Bohle
partner