Desensization Of Hen'S Egg Sensitized Mice As A Result Of Dietary (therapeutic) Intervention With A Specific Mixture Of Non-digestible Oligosaccharides

Abstract

M O N D A Y 661 Desensization Of Hen'S Egg Sensitized Mice As A Result Of Dietary (therapeutic) Intervention With A Specific Mixture Of Non-digestible Oligosaccharides A. Hogenkamp, S. de Kivit, L. M. J. Knippels, J. Garssen, B. C. A. M. van Esch; Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science,Utrecht University, Utrecht, NETHERLANDS, Danone Research-Centre for Specialised Nutrition, Wageningen, NETHERLANDS. RATIONALE: Currently, themain strategy for prevention of food allergic symptoms is the avoidance of the offended food. Non-digestible oligosaccharides, mimicking oligosaccharides present in human milk, have been shown effective in highrisk children. In this study the non-specific desensitizing capacity of a specific oligosaccharides mixture was investigated in allergic mice sensitized to ovalbumin (OVA). METHODS: Mice were sensitized orally once a week for five weeks with OVA using cholera toxin as adjuvant. After the last sensitization micewere fed either a control diet or a specific non-digestible oligosaccharide mixture containing shortchain-Galacto-, longchain-Fructoand Acidicoligosaccharides (9:1:1) (GFA-mixture) for two weeks. Subsequently, mice were challenged intradermally with OVA. The acute allergic skin response, OVA-specific antibodies and IL5 production by splenocytes upon OVA re-stimulation was measured. Dendritic cells (DC) from mesenteric lymph nodes were isolated by MACS, co-cultured with na€ive splenocytes in the presence of OVA and TGF-b. The in vitro induction of Foxp3+ regulatory T-cells was determined by flow cytometry. RESULTS: The GFA-mixture reduced the acute allergic skin response after intradermal OVA challenge. Sensitization with OVA induced upregulation of OVA-specific IgE/IgG1 and IL5 production by splenocytes, but no differences were observed between treatment groups. Preliminary results indicate that DC isolated from GFA-treated mice induced Foxp3+ regulatory T-cells in vitro in the presence of OVA. CONCLUSIONS: A specific mixture of non-digestible oligosaccharide reduced the acute allergic effector response to OVA in mice sensitized to ovalbumin. Preliminary results show a role for regulatory T-cells. Nondigestible oligosaccharides might prove their benefit in supporting allergen specific immunotherapy.