Abstract
A strict gluten-free diet (GFD) is the only currently available therapeutic treatment for patients with celiac disease (CD). Traditionally, treatment with a GFD has excluded wheat, barley and rye, while the presence of oats is a subject of debate. The most-recent research indicates that some cultivars of oats can be a safe part of a GFD. In order to elucidate the toxicity of the prolamins from oat varieties with low, medium, and high CD toxicity, the avenin genes of these varieties were cloned and sequenced, and their expression quantified throughout the grain development. At the protein level, we have accomplished an exhaustive characterization and quantification of avenins by RP-HPLC and an analysis of immunogenicity of peptides present in prolamins of different oat cultivars. Avenin sequences were classified into three different groups, which have homology with S-rich prolamins of Triticeae. Avenin proteins presented a lower proline content than that of wheat gliadin; this may contribute to the low toxicity shown by oat avenins. The expression of avenin genes throughout the development stages has shown a pattern similar to that of prolamins of wheat and barley. RP-HPLC chromatograms showed protein peaks in the alcohol-soluble and reduced-soluble fractions. Therefore, oat grains had both monomeric and polymeric avenins, termed in this paper gliadin- and glutenin-like avenins. We found a direct correlation between the immunogenicity of the different oat varieties and the presence of the specific peptides with a higher/lower potential immunotoxicity. The specific peptides from the oat variety with the highest toxicity have shown a higher potential immunotoxicity. These results suggest that there is wide range of variation of potential immunotoxicity of oat cultivars that could be due to differences in the degree of immunogenicity in their sequences.
Highlights
Celiac disease (CD) is an autoimmune disorder with genetic, environmental, and immunological components as a consequence of sensitivity to gluten proteins present in cereals
As the oat alcohol-soluble proteins have the same solubility features as the gliadins from wheat, throughout the article we will refer to these oat proteins as gliadinlike avenins
Plots show a representative chromatogram of each oat variety and of bread wheat used as a reference
Summary
Celiac disease (CD) is an autoimmune disorder with genetic, environmental, and immunological components as a consequence of sensitivity to gluten proteins present in cereals. The peptides produced in the digestive tract by the partial digestion of gluten from wheat, barley, rye and possibly oats, cause inflammation of the small intestine and villous atrophy. The response is a consequence of deamidation of glutamine residues in peptides, resulting from activity of the tissue transglutaminase (tTG) in the gut mucosa. The modified peptides are able to bind to class II human histocompatibility leukocyte antigen (HLA) molecules DQ2 and DQ8, which stimulate T-cells, resulting in an inflammatory response in the small intestine that leads to flattening of the mucosa [3]. The only effective treatment for CD is to maintain a strict gluten-free diet throughout life. This is complicated as gluten is a ubiquitous additive in most sectors of the prepared-food industry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
