Evaluation of allergenicity of acid-hydrolyzed wheat protein using an in vitro elicitation test.
BACKGROUND
We performed an in vitro elicitation test to determine the ability of different types of wheat-allergic patients' IgE to induce humanized mast cell activation after the addition of various time-treated acid-hydrolyzed wheat proteins (HWPs).


METHODS
The reactivity of heat- and various time-treated acid-hydrolyzed glutens (acid-HGs) and commercial acid-HWP (HWP1), using serum IgE from wheat allergy accompanied by skin and rhinoconjunctival sensitization to HWP1 in the facial soap, pediatric subjects with food allergy to native wheat, adult wheat-dependent exercise-induced anaphylaxis subjects, and nonatopic healthy subjects, was elucidated by dot blot and a luciferase assay-based in vitro elicitation test (EXiLE test).


RESULTS
Serum from subjects sensitized with HWP1 reacted only to acid-HGs (acid-HGs treated for 0.5-3 or 6 h), but not native gluten, in the results of the dot blot. In contrast, sera from pediatric subjects sensitized with native wheat reacted to native gluten more strongly and showed only slight reactions to 0.5- to 1-hour-treated acid-HGs. The results of the in vitro elicitation test showed that acid hydrolyzation of the gluten attenuated antigen-induced luciferase expression in a time-dependent manner for sera from native-wheat-sensitized pediatric subjects. On the other hand, in the sera from HWP1-sensitized subjects, acid hydrolyzation of the gluten for 0.5 h dramatically increased luciferase expression.


CONCLUSIONS
Even after prolonged hydrolyzation, acid-HGs still retained the ability to activate mast cells in the case of HWP1-sensitized subjects.
Division of Novel Foods and Immunochemistry, National Institute of Health Sciences (NIHS), Tokyo, Japan.
Rika
R
Nakamura
Ryosuke
R
Nakamura
Reiko
R
Adachi
Yasuharu
Y
Itagaki
Yuma
Y
Fukutomi
Reiko
R
Teshima
D000143:Acids / Q000737:chemistry; D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology*; D000707:Anaphylaxis / Q000150:complications / Q000276:immunology*; D001250:Asthma, Exercise-Induced / Q000150:complications / Q000276:immunology*; D015550:Cell Degranulation; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003233:Conjunctivitis, Allergic / Q000150:complications / Q000276:immunology*; D005260:Female; D005983:Glutens / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D006868:Hydrolysis; D007073:Immunoglobulin E / Q000378:metabolism; D007223:Infant; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D008875:Middle Aged; D010940:Plant Proteins / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology*; D011485:Protein Binding; D012221:Rhinitis, Allergic, Perennial / Q000150:complications / Q000276:immunology*; D012867:Skin / Q000276:immunology*; D014908:Triticum / Q000009:adverse effects / Q000276:immunology; D021182:Wheat Hypersensitivity / Q000150:complications / Q000276:immunology*; D055815:Young Adult
D000143:Acids; D000485:Allergens; D010940:Plant Proteins; D007073:Immunoglobulin E; D005983:Glutens