title: Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potential.
abstract: BACKGROUND
  The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release.
  
  
  METHODS
  An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel.
  
  
  RESULTS
  In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments M(r) L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-gamma/IL-13 ratio and IFN-gamma/IL-4 ratio of CFSE(low) CD4(+) T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products.
  
  
  CONCLUSIONS
  Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein.
authors.affiliation: Department of Pediatrics, Division of General Pediatrics, Medical University of Vienna, Vienna, Austria.
authors.forename: T
authors.initials: T
authors.lastname: Eiwegger
authors.forename: N
authors.initials: N
authors.lastname: Rigby
authors.forename: L
authors.initials: L
authors.lastname: Mondoulet
authors.forename: H
authors.initials: H
authors.lastname: Bernard
authors.forename: M-T
authors.initials: MT
authors.lastname: Krauth
authors.forename: A
authors.initials: A
authors.lastname: Boehm
authors.forename: E
authors.initials: E
authors.lastname: Dehlink
authors.forename: P
authors.initials: P
authors.lastname: Valent
authors.forename: J M
authors.initials: JM
authors.lastname: Wal
authors.forename: E N C
authors.initials: EN
authors.lastname: Mills
authors.forename: Z
authors.initials: Z
authors.lastname: Szépfalusi
mesh_terms: D000485:Allergens / Q000276:immunology* / Q000378:metabolism*; D052179:Antigens, Plant; D001491:Basophils / Q000276:immunology; D016022:Case-Control Studies; D049109:Cell Proliferation; D003429:Cross Reactions; D016207:Cytokines / Q000378:metabolism; D004063:Digestion; D004386:Duodenum / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005512:Food Hypersensitivity / Q000276:immunology* / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology* / Q000378:metabolism*; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D008565:Membrane Proteins; D010940:Plant Proteins / Q000276:immunology* / Q000378:metabolism*; D012107:Research Design; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; D016207:Cytokines; D006023:Glycoproteins; D008565:Membrane Proteins; D010940:Plant Proteins; D007073:Immunoglobulin E