Effect of two synthetic alpha-gliadin peptides on lymphocytes in celiac disease: identification of a novel class of opioid receptors.
Two synthetic peptides containing residues 43-47 and 43-49 of alpha-gliadin were tested for inhibition of leukocyte migration in 47 patients with celiac disease. In nineteen patients, all on a normal diet, leukocyte migration was inhibited by the peptides and naloxone blocked this effect. In twenty-eight patients (24 of whom were on strict gluten-free diet) leukocyte migration was not affected by the peptides. Our results suggest that alpha-gliadin-(43-49), Tyr-Pro-Gln-Pro-Gln-Pro-Phe, is closely related to the active fragment, or to one of the active fragments of alpha-gliadin, and that it interacts with receptors that are similar to but not identical with the known opiate receptors.
D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D002446:Celiac Disease / Q000276:immunology*; D002464:Cell Migration Inhibition; D002648:Child; D002675:Child, Preschool; D005260:Female; D005903:Gliadin / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007223:Infant; D007962:Leukocytes / Q000276:immunology*; D008297:Male; D010446:Peptide Fragments / Q000276:immunology* / Q000378:metabolism; D010940:Plant Proteins / Q000276:immunology*; D011957:Receptors, Opioid / Q000378:metabolism
D010446:Peptide Fragments; D010940:Plant Proteins; D011957:Receptors, Opioid; D005903:Gliadin