Wheat amylase/trypsin inhibitors exacerbate intestinal and airway allergic immune responses in humanized mice

Publication date: Available online 21 March 2018
Source:Journal of Allergy and Clinical Immunology
Author(s): Iris Bellinghausen, Benno Weigmann, Victor Zevallos, Joachim Maxeiner, Sonja Reißig, Ari Waisman, Detlef Schuppan, Joachim Saloga
BackgroundAmylase-trypsin inhibitors (ATIs) in wheat and related cereals are potent activators of myeloid innate immune cells via engagement of TLR4. Furthermore, ATIs have been shown to serve as adjuvants in experimental intestinal inflammatory diseases.ObjectiveThe aim of this study was to analyze whether ATIs are also modifiers of allergic inflammation.MethodsTherefore, CD4⁺ T cells from grass or birch pollen sensitized donors were stimulated with autologous allergen-pulsed dendritic cells in the presence or absence of ATIs or the control storage protein zein from corn. To analyze allergen-induced gut and lung inflammation, immunodeficient mice were engrafted with PBMC from these allergic donors plus the respective allergen, and fed with selected diets. Three weeks later, inflammation was induced by rectal or intranasal allergen challenge and monitored by mini-endoscopy or airway hyperreactivity (AHR), respectively.ResultsAllergen-specific T cell proliferation and cytokine production was significantly exacerbated by ATIs and not by zein. In vivo, allergen-specific human IgE was strongly elevated in sera of mice receiving an ATI-containing diet compared to mice that were fed gluten- and thus ATI-free. Importantly, allergen-induced IgE-dependent colitis and AHR were also enhanced in ATI-fed mice. Gut inflammation was further increased in mice receiving an additional ATI injection and even detectable in the absence of the aeroallergen, while zein had no such effect. Injection of anti-human TLR4 mAbs or the anti-human IgE mAb omalizumab completely abolished ATI-induced allergic inflammation.ConclusionThese results underline that wheat ATIs are important nutritional activators and adjuvants of allergy which might be exploited for nutritional therapeutic strategies.Clinical ImplicationsAllergen-induced IgE-mediated inflammation of the intestine and the lung is exacerbated by ATIs which might be important for future therapies.

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