Gliadins, and primarily α-
gliadins containing several sequences such as
aa 31-49, aa 56-88 (33-mer),
aa 57-68, and aa 69-82, are critical in the induction of immune response or toxic reaction leading to the development of
celiac disease (CLD). The role of
IgA anti-
gliadin antibodies (
IgA AGA) is unknown. To this end, we prepared several humanized monoclonal
IgA AGA using transgenic α1KI mice. Employing Pepscan with overlapping decapeptides of α-
gliadin we observed a robust similarity between the specificity of humanized mouse monoclonal
IgA AGA and
IgA AGA from patients with florid CLD. The common
immunodominant region included several sequential
epitopes localized in the N-terminal part of α-
gliadin (QFQGQQQPFPPQQPYPQPQPFP, aa 29-50, and QPFPSQQPYLQL, aa 47-58). Notably,
IgA AGA produced by clones 8D12, 15B9, 9D12, and 18E2 had significant reactivity against sequences localized in the 33-mer, LQLQPFPQPQ (aa 56-65) and PQLPYPQPQPFL (aa 69-80). Humanized mouse monoclonal
IgA AGA that have a known specificity are suitable as standard in ELISAs to detect serum
IgA AGA of CLD patients and for studying the AGA pathogenic role in CLD, especially for analyzing the translocation of complex of specific
IgA antibodies and individual
gliadin peptides through enterocyte barrier.