Amb a 1 isoforms: Unequal siblings with distinct immunological features.

M Wolf, T E Twaroch, S Huber, M Reithofer, M Steiner, L Aglas, M Hauser, I Aloisi, C Asam, H Hofer, M A Parigiani, C Ebner, B Bohle, P Briza, A Neubauer, F Stolz, B Jahn-Schmid, M Wallner, F Ferreira

Allergy 2017 Dec

filter terms:

Ragweed pollen represents a major allergy risk factor. Ragweed extracts contain five different isoforms of the major allergen Amb a 1. However, the immunological characteristics of Amb a 1 isoforms are not fully investigated. Here, we compared the physicochemical and immunological properties of three most important Amb a 1 isoforms. After purification, the isoforms were physicochemically characterized, tested for antibody binding and induction of human T-cell proliferative responses. Their immunological properties were further evaluated in vitro and in vivo in a mouse model. Amb a 1 isoforms exhibited distinct patterns of IgE binding and immunogenicity. Compared to Amb a 1.02 or 03 isoforms, Amb a 1.01 showed higher IgE-binding activity. Isoforms 01 and 03 were the most potent stimulators of patients' T cells. In a mouse model of immunization, Amb a 1.01 induced higher levels of IgG and IgE antibodies when compared to isoforms 02 and 03. Interestingly, ragweed-sensitized patients also displayed an IgG response to Amb a 1 isoforms. However, unlike therapy-induced antibodies, sensitization-induced IgG did not show IgE-blocking activity. The present study showed that naturally occurring isoforms of Amb a 1 possess different immunogenic and sensitizing properties. These findings should be considered when selecting sequences for molecule-based diagnosis and therapy for ragweed allergy. Due to its high IgE-binding activity, isoform Amb a 1.01 should be included in diagnostic tests. In contrast, due to their limited B- and T-cell cross-reactivity patterns, a combination of different isoforms might be a more attractive strategy for ragweed immunotherapy. © 2017 The Authors. Allergy Published by John Wiley & Sons Ltd.

Citation

M Wolf, T E Twaroch, S Huber, M Reithofer, M Steiner, L Aglas, M Hauser, I Aloisi, C Asam, H Hofer, M A Parigiani, C Ebner, B Bohle, P Briza, A Neubauer, F Stolz, B Jahn-Schmid, M Wallner, F Ferreira. Amb a 1 isoforms: Unequal siblings with distinct immunological features. Allergy. 2017 Dec;72(12):1874-1882