Molecular characterization of α-gliadin gene sequences in Indian wheat cultivars vis-à-vis celiac disease eliciting epitopes
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α-Gliadin proteins of the wheat gluten form a multigene family encoded by genomic loci Gli-A2, Gli-B2 and Gli-D2 located on the homoeologous wheat chromosomes 6AS, 6BS, and 6DS, respectively which upon partial digestion elicits celiac disease (CD) in the genetically susceptible individuals. The present investigation was planned to study the variations in the amino acid sequence of the α-gliadin proteins and CD eliciting epitopes in the Indian wheat cultivars. Representative wheat varieties released and cultivated in India during the period 1905–2011 were selected for studying the α-gliadin genes by cloning and sequencing followed by in silico analysis of the gene sequences. A lot of variation for α-gliadin gene sequences especially in T cell stimulatory epitopes glia-α9, glia-α20, glia-α2 and glia-α was observed in different wheat varieties. Modern varieties released during 1971–2011 had higher proportion of intact T-cell stimulatory epitopes. The old wheat varieties released in the period 1905–1970 on the other hand had large proportion of variant epitopes. We identified three wheat varieties namely C591, C273 and K78 having only variant epitopes at Gli-D2 and Gli-B2 and both intact and variant epitopes at Gli-A2. Identification of lower proportion of T-cell stimulatory epitopes in these three varieties is the first step towards developing a wheat variety less immunogenic for celiac disease patients. The gene sequences of the selected varieties have been submitted at NCBI with accession numbers GenBank KJ410473–KJ410488.
Keywordsα-Gliadin genes Celiac disease T-cell stimulatory epitopes Wheat
- HLA-DQ2 and HLA-DQ8
Human leukocyte antigen DQ2 and DQ8 locus
Open reading frame
High molecular weight
Low molecular weight
Financial assistance provided by Department of Biotechnology, Ministry of Science and Technology, Government of India, New Delhi in the form of various grants is gratefully acknowledged.
Anupriya Kaur: Acquisition of data, analysis and interpretation of data, statistical analysis; Navtej S. Bains: Plant Material, critical revision of the manuscript; Ajit Sood: Study concept, critical revision of the manuscript; Bharat Yadav: Analysis and interpretation of data; Priti Sharma: Acquisition of data; Monika Garg: Acquisition of data and manuscript editing; Vandana Midha: Critical revision of the manuscript; Parveen Chhuneja: Study concept and design, Study Supervision, drafting of the manuscript, Manuscript submission.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interests.
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