Evaluating risks of celiac disease from dietary proteins using gluten sandwich ELISAs, a celiac peptide and protein database, and an ABeta degrees.DQ8.NOD mouse model

Celiac disease (CD) is an immune-mediated enteropathy triggered by glutens in wheat, barley, rye, and possibly oat in individuals carrying HLA DQ2.5 or DQ8 genes. Lifelong avoidance of specific glutens is the only effective treatment for CD consumers. Homologous proteins from other grains such as corn and rice do not elicit CD. The overall goal of this research is to help identify immunogenic glutens and thus to help prevent CD. The first aim was to compare four commercial sandwich ELISA assays for detection of glutens in a variety of foods and ingredients. Although the numerical results differed between assays and samples, the four assays could be successfully used to support the definitions of gluten-free in various samples. The second aim was to develop a CD database that can be used to predict potential risks from novel proteins used as ingredients or produced by genetically-modified crops for eliciting CD. The constructed database includes 1,114 peptides and 68 representative gluten proteins with published evidence of CD activity. Exact match and FASTA comparison programs could be used for evaluating novel proteins for homology with these peptides and proteins. Query proteins containing an exact peptide match or having a FASTA alignment of \u3e45% identity with ≥100 amino acids overlap to any of the 68 proteins and with an E score of \u3c 1e-16, may represent a risk for CD. Extensive testing showed that only prolamins within the Pooideae grass subfamily meet these criteria. The third aim was to compare cultivars of wheat and bread ingredients that might pose a greater risk of sensitizing or eliciting CD reactions in the consumers carrying HLA DQ8 haplotype. A transgenic DQ8.NOD mouse model was used to test T cell responses to gluten digests from whole wheat breads made with two Hard Red Winter wheat cultivars, Turkey Red and Expedition, and a commercial Spring wheat. Results indicated that the Turkey Red cultivar was less immunogenic compared to the others. Addition of 1% vital gluten and TG2 deamidation of glutens led to higher immunogenicity, and one commercial bread was more immunogenic than the other