Bøgh, Katrine Lindholm

Dahl, L.

Kroghsbo, Stine

Madsen, Charlotte Bernhard

Rigby, N.

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 20, 2017Degraded food allergens may retain their sensitising capacityBøgh, Katrine Lindholm; Kroghsbo, Stine; Dahl, L.; Rigby, N.; Madsen, Charlotte BernhardPublication date:2007Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Bøgh, K. L., Kroghsbo, S., Dahl, L., Rigby, N., & Madsen, C. B. (2007). Degraded food allergens may retain theirsensitising capacity.What makes an antigen an allergen is not currently known. However, food allergens are assumed to be stable to heat, acid and proteolysis making them resistance to degradation during food preparation and digestion. It is believed that a protein needs to be presented to the immune system in intact form to sensitise an individual and elicit an allergic reaction.   The aim of this project was to examine the sensitising capacity of a digested allergen known to be allergenic.   Understanding the properties that make a protein a food allergen has implications for development of hypoallergenic foods. Break down products from protein ingredients is especially important for manufactures using hydrolysates in hypoallergenic infant formulas. Cow’s milk-based formulas and even extensively hydrolysed milk formulas are known still to provoke allergenic reaction Currently there are no firm criteria on which to base the manufacture of hypoallergenic formulas.   Allergen: A purified peanut allergen Ara h 1 was digested in an in vitro model designed to mimic the human digestion. The digesta contained to intact Ara h 1. Ara h 1 digesta was composed of peptides of ≤ 2 kDa of which approximately 1/3 had aggregated to larger complexes of Mr 4000-10000.     Animal model: Brown Norway rats were immunised i.p. three times with 1 µg, 50 µg or 200 µg of intact Ara h 1 or 200 µg of digested Ara h 1.        Both intact and digested Ara h 1 were able to induce an immunologic (IgG1, IgG2a) as well as an allergic (IgE) response. Looking at the immunologic antibody response it is clear that intact Ara h 1 had a higher sensitising capacity than digested Ara h 1. However, it is evident that some epitopes have the ability to survive the digestion process (Fig. 1).  Degraded food allergens may retain their sensitising capacity Nielsen, KK¹; Kroghsbo, S¹; Dahl, L¹; Rigby, N²; Mills, ENC²; Madsen, C¹  1Technical University of Denmark, National Food Insitute, Department of Toxicology and Risk Assessment, Copenhagen, Denmark; 2Institute of Food Research, Biochemistry, Norwich, United Kingdom         Figure 1: Comparison of intact and digested Ara h 1-specific IgE response In general rats immunised with intact Ara h 1 reacted more readily with intact than digested Ara h 1. In contrast rats immunised with digested Ara h 1 reacted equally well with digested and intact Ara h 1.  Looking at the allergic response, represented by an RBL-assay, it is seen that both intact and digested Ara h 1 were able to induce an allergic response. However, sera raised against digested Ara h 1 had a high mediator release when stimulated with both intact and digested Ara h 1 (Fig. 2a), while sera raised against intact Ara h 1 had only a high release when stimulated whit intact Ara h 1 (Fig. 2b).               Figure 2: Allergen-specific IgE-mediated mediator release of RBL cells sensitised with sera raised against either digested (A) or intact (B) Ara h 1.   Digestion of an allergen to small peptide fragments does not necessarily lead to elimination of the sensitising potential of that allergen Could this be a result of these small peptide fragments aggregating to complexes of larger sizes? This is now being investigated in a Ph.D. project supported by Danish Dairy Board.   Background Aim of project Perspectives for the dairy Conclusion Methods Digested and intact Ara h 1-specific IgG1 responsePBS200 µg digest1 µg Ara h1 50 µg Ara h 1200 µg Ara h 12610141822 Anti-digested Ara h 1Anti-intact Ara h 1Titre (Log2)Sera raised against 200 µg digested Ara h 19 10 11 12 13 14 15 16 17 18 19 20 21 22 23 240102030405060708090100AAnimal no.%β-hexoaminidase releaseSera raised aganist 200 µg intact Ara h 149 50 51 52 53 54 55 56 57 58 59 60010203040506070809010010 µg digested Ara h 1/ml 100 µg digested Ara h 1/ml10 µg intact Ara h 1/ml 100 µg intact Ara h 1/mlBAnimal no.%β-hexoaminidase releaseResults 

Degraded food allergens may retain their sensitising capacity

http://orbit.dtu.dk/ws/files/35964395/poster.pdf

Degraded food allergens may retain their sensitising capacity

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology