Studies in vivo of ω-gliadins in gluten sensitivity (coeliac sprue disease)

1. Highly purified ω-gliadins from wheat were used to challenge gluten-sensitized individuals. Characteristic responses by mucosal CD3⁺ and γδ⁺ lymphocytes were demonstrated. Each lymphocyte subset showed an increase within 8-12 h post-challenge, indicating a specific response by the rectal mucosa to this gliadin species. 2. Available sequence data for the ω-gliadins and homologous proteins from barley and rye indicate a common repeating octapeptide motif (consensus PQQPFPQQ). The results indicate, therefore, that the octapeptide repeat, or a contained sequence such as PQQP, plays an important role in the mucosal immunopathology of gluten sensitivity.