Subproject 3 - Stratification in skin-induced and gut-induced wheat allergy as a model for human food allergy

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a common form of IgE-mediated wheat allergy. Food allergies are caused by a loss of tolerance either in the intestine or in the skin. We can divide WDEIA patients into those who have acquired their sensitisation in the gut (WDEIA_gut) and those who have acquired it through the skin (WDEIA_skin). The latter are characterised by a special sensitisation profile. Our aim is to understand the underlying mechanisms of allergic sensitisation and the predisposition that lead to the different immune responses in patients with WDEIA. For this purpose, patients are divided into four groups: 1) allergic WDEIA_gut, 2) allergic WDEIA_skin, 3) non-allergic with sensitisation (IgE), and 4) non-allergic without sensitisation (IgE_abs). These groups will be further investigated for their barrier function in skin and intestine, local bacterial colonisation, uptake of wheat proteins through intestine and skin and the allergenicity of wheat proteins. KIT will isolate and provide well defined and characterised wheat protein fractions to identify the most allergenic fractions. This is complemented by the determination of wheat allergens in biological samples to compare the barrier function of the intestine or skin and its changes. In close cooperation with the other applicants, samples will be taken to identify biomarkers (SP5) and individual bacterial colonisation (SP6) and the results will be compared with those of SP1 and SP2. Together we will look for evidence of predisposition and resistance to food allergies, which will enable us to better identify individuals at risk and prevention options.