title: Effect of in vitro gastric and duodenal digestion on the allergenicity of grape lipid transfer protein.
abstract: BACKGROUND
  Severe grape allergy has been linked to lipid transfer protein (LTP) sensitization. LTPs are known to be resistant to pepsin digestion, although the effect of gastroduodenal digestion on its allergenicity has not been reported.
  
  
  OBJECTIVE
  We sought to investigate the effect of gastric and gastroduodenal digestion on the allergenic activity of grape LTP.
  
  
  METHODS
  The proteolytic stability of grape LTP was investigated by using an in vitro model of gastrointestinal digestion. The allergenicity of LTP and its digesta was assessed in vitro by means of IgE immunoblotting, RASTs, and in vivo skin prick tests in the same patients with grape allergy.
  
  
  RESULTS
  Grape LTP was resistant to gastric digestion, and yielded a 6000-d relative molecular mass C-terminally trimmed fragment after duodenal digestion. This fragment retained the in vitro IgE reactivity of the intact protein. Inclusion of phosphatidylcholine during gastric digestion protected the LTP to a limited extent against digestion. Digestion did not affect the in vivo (skin prick test) biologic activity of LTP.
  
  
  CONCLUSIONS
  The allergenic activity of grape LTP was highly resistant to in vitro digestion. This property might facilitate sensitization through the gastrointestinal tract and might also potentiate the ability of LTPs to elicit severe allergic reactions in sensitized individuals.
  
  
  CONCLUSIONS
  Purified natural allergens will facilitate the development of component-resolved diagnostic approaches, including allergen chips. This study contributes to our understanding of the role digestion plays in symptom elicitation in true food allergy.
authors.affiliation: Allergy Research Laboratories, 2nd Paediatric Clinic, University of Athens Greece, 41 Fidippidou str., Athens 11527, Greece. emi@allergy.gr
authors.forename: Emilia
authors.initials: E
authors.lastname: Vassilopoulou
authors.forename: Neil
authors.initials: N
authors.lastname: Rigby
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Moreno
authors.forename: Laurian
authors.initials: L
authors.lastname: Zuidmeer
authors.forename: Jaap
authors.initials: J
authors.lastname: Akkerdaas
authors.forename: Ioannis
authors.initials: I
authors.lastname: Tassios
authors.forename: Nikos G
authors.initials: NG
authors.lastname: Papadopoulos
authors.forename: Photini
authors.initials: P
authors.lastname: Saxoni-Papageorgiou
authors.forename: Ronald
authors.initials: R
authors.lastname: van Ree
authors.forename: Clare
authors.initials: C
authors.lastname: Mills
mesh_terms: D000485:Allergens / Q000276:immunology; D052179:Antigens, Plant; D001491:Basophils / Q000276:immunology; D002352:Carrier Proteins / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004063:Digestion / Q000502:physiology*; D004386:Duodenum / Q000378:metabolism*; D005512:Food Hypersensitivity / Q000097:blood / Q000276:immunology; D005750:Gastric Juice / Q000378:metabolism*; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D010940:Plant Proteins; D027843:Vitis / Q000276:immunology*
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; C511920:lipid transfer proteins, plant; D007073:Immunoglobulin E