Effect of in vitro gastric and duodenal digestion on the allergenicity of grape lipid transfer protein.
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.
Vassilopoulou
Emilia
E
Allergy Research Laboratories, 2nd Paediatric Clinic, University of Athens Greece, 41 Fidippidou str., Athens 11527, Greece. emi@allergy.gr
Rigby
Neil
N
Moreno
F Javier
FJ
Zuidmeer
Laurian
L
Akkerdaas
Jaap
J
Tassios
Ioannis
I
Papadopoulos
Nikos G
NG
Saxoni-Papageorgiou
Photini
P
van Ree
Ronald
R
Mills
Clare
C
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*
D000485:Allergens; D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; C511920:lipid transfer proteins, plant; D007073:Immunoglobulin E