title: Effective shutdown in the expression of celiac disease-related wheat gliadin T-cell epitopes by RNA interference.
abstract: 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.
authors.affiliation: Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Cientificas, E-14080 Córdoba, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Gil-Humanes
authors.forename: Fernando
authors.initials: F
authors.lastname: Pistón
authors.forename: Stig
authors.initials: S
authors.lastname: Tollefsen
authors.forename: Ludvig M
authors.initials: LM
authors.lastname: Sollid
authors.forename: Francisco
authors.initials: F
authors.lastname: Barro
mesh_terms: D001483:Base Sequence; D002446:Celiac Disease / Q000276:immunology*; D002460:Cell Line; D018984:Epitopes, T-Lymphocyte / Q000235:genetics* / Q000276:immunology; D005903:Gliadin / Q000235:genetics* / Q000276:immunology; D006683:HLA-DQ Antigens / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D030821:Plants, Genetically Modified / Q000235:genetics / Q000276:immunology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology; D014908:Triticum / Q000235:genetics / Q000276:immunology*
chemical_list: D018984:Epitopes, T-Lymphocyte; D006683:HLA-DQ Antigens; D034741:RNA, Small Interfering; D005903:Gliadin