Celiac disease (CD) is an enteropathy triggered by the ingestion of gluten proteins from wheat and similar proteins from barley and rye. The inflammatory reaction is controlled by T cells that recognize gluten peptides in the context of human leukocyte antigen (HLA) DQ2 or HLA-DQ8 molecules. The only available treatment for the disease is a lifelong gluten-exclusion diet. We have used RNAi to down-regulate the expression of gliadins in bread wheat. A set of hairpin constructs were designed and expressed in the endosperm of bread wheat. The expression of gliadins was strongly down-regulated in the transgenic lines. Total gluten protein was extracted from transgenic lines and tested for ability to stimulate four different T-cell clones derived from the intestinal lesion of CD patients and specific for the DQ2-α-II, DQ2-γ-VII, DQ8-α-I, and DQ8-γ-I epitopes. For five of the transgenic lines, there was a 1.5-2 log reduction in the amount of the DQ2-α-II and DQ2-γ-VII epitopes and at least 1 log reduction in the amount of the DQ8-α-I and DQ8-γ-I epitopes. Furthermore, transgenic lines were also tested with two T-cell lines that are reactive with ω-gliadin epitopes. The total gluten extracts were unable to elicit T-cell responses for three of the transgenic wheat lines, and there were reduced responses for six of the transgenic lines. This work shows that the down-regulation of gliadins by RNAi can be used to obtain wheat lines with very low levels of toxicity for CD patients.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Sep 28 2010|
- Celiac sprue
- Gluten intolerance
- Post-transcriptional gene silencing