title: The effect of the food matrix on in vivo immune responses to purified peanut allergens.
abstract: There is little knowledge about the factors that determine the allergenicity of food proteins. One aspect that remains to be elucidated is the effect of the food matrix on immune responses to food proteins. To study the intrinsic immunogenicity of allergens and the influence of the food matrix, purified peanut allergens (Ara h 1, Ara h 2, Ara h 3, or Ara h 6) and a whole peanut extract (PE) were tested in the popliteal lymph node assay (PLNA) and in an oral model of peanut hypersensitivity. In the PLNA, peanut proteins were injected into the hind footpad of BALB/c mice; in the oral exposure experiments C3H/HeOuJ mice were gavaged weekly with PE or allergens in the presence of cholera toxin (CT). Upon footpad injection, none of the allergens induced significant immune activation. In contrast, PE induced an increase in cell number, cytokine production, and activation of antigen-presenting cells. Furthermore, the presence of a food matrix enhanced the immune response to the individual allergens. Oral exposure to the purified allergens in the presence of CT induced specific IgE responses, irrespective of the presence of a food matrix. These results suggest that purified peanut allergens possess little intrinsic immune-stimulating capacity in contrast to a whole PE. Moreover, the data indicate that the food matrix can influence responses to individual proteins and, therefore, the food matrix must be taken into account when developing models for allergenic potential assessment.
authors.affiliation: Department of Immunotoxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. F.vanWijk@iras.uu.nl
authors.forename: F
authors.initials: F
authors.lastname: van Wijk
authors.forename: S
authors.initials: S
authors.lastname: Nierkens
authors.forename: I
authors.initials: I
authors.lastname: Hassing
authors.forename: M
authors.initials: M
authors.lastname: Feijen
authors.forename: S J
authors.initials: SJ
authors.lastname: Koppelman
authors.forename: G A H
authors.initials: GA
authors.lastname: de Jong
authors.forename: R
authors.initials: R
authors.lastname: Pieters
authors.forename: L M J
authors.initials: LM
authors.lastname: Knippels
mesh_terms: D055516:2S Albumins, Plant; D000485:Allergens / Q000494:pharmacology; D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D052179:Antigens, Plant; D010367:Arachis / Q000737:chemistry / Q000276:immunology*; D018122:B7-1 Antigen / Q000276:immunology; D051940:B7-2 Antigen; D002772:Cholera Toxin / Q000008:administration & dosage; D016207:Cytokines / Q000096:biosynthesis; D004041:Dietary Fats / Q000494:pharmacology*; D005260:Female; D006023:Glycoproteins / Q000494:pharmacology; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D008198:Lymph Nodes / Q000187:drug effects* / Q000276:immunology; D008562:Membrane Glycoproteins / Q000276:immunology; D008565:Membrane Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D021183:Peanut Hypersensitivity / Q000276:immunology*; D010940:Plant Proteins / Q000494:pharmacology
chemical_list: D055516:2S Albumins, Plant; D000485:Allergens; D015703:Antigens, CD; D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; C500890:Ara h 2 allergen, Arachis hypogaea; C492737:Ara h 6 allergen, Arachis hypogaea; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D016207:Cytokines; D004041:Dietary Fats; D006023:Glycoproteins; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010940:Plant Proteins; D018799:Intercellular Adhesion Molecule-1; D007073:Immunoglobulin E; D002772:Cholera Toxin