Cereal Chem 72:475-479  |  VIEW ARTICLE

Activation of Celiac Disease Immune System by Specific alpha- Gliadin Peptides.

M.-L. L"hdeaho, E. Vainio, M. Lehtinen, P. Parkkonen, J. Partanen, S. Koskimies, and M. M"ki. Copyright 1995 by the American Association of Cereal Chemists, Inc. 

Two different gliadin molecules (designated alpha-gliadin and alpha/beta-gliadin) were synthesized as 52 and 58 ten amino acid (aa) long overlapping peptides for the determination of their B-cell epitopes. Monoclonal antibodies and human serum pools revealed two epitopes common for both gliadins (peptide 14 aa:s 66-75 and peptides 34alpha aa:s 166-175, 36alpha/beta aa:s 176-185) and two unique epitopes (alpha- gliadin peptides 48 aa:s 236-245 and alpha/beta-gliadin peptide 52 aa:s 256-275). In addition, peptide 9 (QPYPQPQPFP) aa:s 41-50 and peptide 42 (LGQGSFRPSQ) aa:s 206-215 were detectable by monoclonal antibodies and serum pools from patients with untreated celiac disease but not by serum pools from disease control patients who had antigliadin antibodies. Patients with celiac disease were also studied for their human leukocyte antigen (HLA) class II status (the presence of genetically determined proteins on antigen- presenting cells that are important for immunological recognition). Antigliadin antibody response to peptide QPYPQPQPFP was restricted by celiac disease (and HLA class II) because relative amounts of the antipeptide antibodies were significantly (P less than 0.05) increased in celiac disease patients. The HLA alleles DQA1*0501 and DQB1*0201 are strongly associated with celiac disease. The difference between patients with celiac disease and healthy control subjects with regard to peptide QPYPQPQPFP suggest that this region in the gliadin molecule is of pathogenetic importance in celiac disease.