Enzymatic detoxification of gluten by germinating wheat proteases: implications for new treatment of celiac disease.
BACKGROUND
Currently the only treatment for celiac disease is a lifelong gluten-free diet. The diet is, however, often burdensome, and thus new treatment options are warranted. We isolated proteases from germinating wheat grain naturally meant for total digestion of wheat storage proteins and investigated whether these enzymes can diminish toxic effects of gluten in vitro and ex vivo.


METHODS
Pepsin and trypsin digested (PT) gliadin was pretreated with proteases from germinating wheat, whereafter the degradation was analyzed by HPLC-MS (high-performance liquid chromatography and mass spectroscopy) and sodium dodecyl sulphate polyacrylamide gel electrophoresis. The toxicity of cleaved PT-gliadin products was assessed in Caco-2 epithelial cells, celiac patient-derived T cells, and in human small intestinal mucosal organ culture biopsies.


RESULTS
Proteases from germinating wheat degraded gliadin into small peptide fragments, which, unlike unprocessed PT-gliadin, did not increase epithelial permeability, induce cytoskeletal rearrangement or changes in ZO-1 expression in Caco-2 cells. Pretreated gliadin did not stimulate T cell proliferation in vitro or enhance the production of autoantibodies to culture supernatants and the activation of CD25+ lymphocytes in the organ culture to the same extent as unprocessed PT-gliadin.


CONCLUSIONS
Germinating wheat enzymes reduce the toxicity of wheat gliadin in vitro and ex vivo. Further studies are justified to develop an alternative therapy for celiac disease.
Stenman
Satumarja M
SM
Pediatric Research Center, Medical School, University of Tampere, Finland.
Venäläinen
Jarkko I
JI
Lindfors
Katri
K
Auriola
Seppo
S
Mauriala
Timo
T
Kaukovirta-Norja
Anu
A
Jantunen
Anna
A
Laurila
Kaija
K
Qiao
Shuo-Wang
SW
Sollid
Ludvig M
LM
Männisto
Pekka T
PT
Kaukinen
Katri
K
Mäki
Markku
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D018938:Caco-2 Cells; D002446:Celiac Disease / Q000201:enzymology / Q000473:pathology / Q000628:therapy*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005903:Gliadin / Q000493:pharmacokinetics*; D006801:Humans; D008658:Inactivation, Metabolic; D007421:Intestine, Small / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010447:Peptide Hydrolases / Q000378:metabolism*; D011379:Prognosis; D013601:T-Lymphocytes / Q000276:immunology; D014908:Triticum / Q000201:enzymology; D055815:Young Adult
D005903:Gliadin; D010447:Peptide Hydrolases