Oleosins in nut allergies : biochemical characterization of allergens and analysis of
cross-reactivity with pollens

Contrary to water-soluble allergens, hydrophobic allergens have been poorly investigated so far due
to extraction problem. The present project focuses on the biochemical characterization of oleosins, a
family of hydrophobic allergens involved in nut allergies. The first step will be to prepare aqueous
extracts containing oleosins from peanut and mustard seeds by adapting the method set up on
rapeseed oleosins. Allergens will be detected in these extracts by immunoblot using sera from
allergic patients and identified by proteomic. To ascertain allergen identification, IgE binding will be
performed on recombinant version of the allergens. Moreover, truncated recombinant allergens will
be used to deciphering immunoreactive domains. As oleosins are present not only in seeds but also
in pollens and display a highly homologous domain, these allergens might be involved in
cross-allergies between seeds from different species and between seed and pollen. This hypothesis
will be investigated. Overall, this project will contribute to better evaluate the importance of
hydrophobic allergens and should release new methods to produce aqueous extracts containing
hydrophobic allergens, useful for diagnostic purposes.