31-43 amino acid sequence of the alpha-gliadin induces anti-endomysial antibody production during in vitro challenge.
BACKGROUND
Wheat gliadin is the culprit antigen of coeliac disease (CD). Two short sequences of NH2-terminal portion of gliadin seem to be responsible for CD. Antiendomysial antibodies (EMA), highly sensitive and specific for CD, are detectable in the culture media from treated CD patients, after in vitro challenge with peptic-tryptic (PT) digest of gliadin. In this study we detected EMA production after in vitro challenge with 31-43 peptide. We used 56-68 peptide, lacking toxic sequences, as a negative control.


METHODS
Duodenal samples from 11 treated CD patients and 9 control patients were cultured with 31-43 and 56-68 peptides and PT gliadin. Indirect immunofluorescence analysis was used for EMA detection.


RESULTS
EMA were detected in culture media of 10 of 11 specimens challenged with PT-gliadin and in the media of all specimens challenged with 31-43 peptide. No EMA were detectable in any treated patients cultured with 56-68 peptide or with medium alone. No EMA were observed in cultures of control specimens.


CONCLUSIONS
The ability of the 31-43 sequence of the alpha-gliadin to induce EMA production suggests its involvement in the pathogenesis of CD. Furthermore, it may be a more useful antigenic substance than PT gliadin for both in vitro and in vivo studies of CD.
Picarelli
A
A
Medical Clinic II, University of Rome La Sapienza, and Superiore Institute of Health, Italy.
Di Tola
M
M
Sabbatella
L
L
Anania
M C
MC
Di Cello
T
T
Greco
R
R
Silano
M
M
De Vincenzi
M
M
D000328:Adult; D000917:Antibody Formation / Q000187:drug effects; D000941:Antigens; D001323:Autoantibodies / Q000032:analysis / Q000096:biosynthesis*; D002446:Celiac Disease / Q000276:immunology* / Q000473:pathology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005903:Gliadin / Q000276:immunology* / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology* / Q000494:pharmacology
D000941:Antigens; D001323:Autoantibodies; D010446:Peptide Fragments; D005903:Gliadin