Induction of antigen-specific tolerance by oral administration of Lactococcus lactis delivered immunodominant DQ8-restricted Gliadin peptide in sensitized NOD AB° DQ8 transgenic mice

摘要

Active delivery of recombinant autoantigens or allergens at the intestinal mucosa by genetically modified Lactococcus lactis (LL) provides a novel therapeutic approach for the induction of tolerance. Celiac disease is associated with either HLA-DQ2 or HLA-DQ8 restricted responses to specific antigenic epitopes of gliadin, and may be treated by induction of antigen-specific tolerance. We investigated whether oral administration of LL-delivered DQ8-specific gliadin epitope induces antigen-specific tolerance.L. lactiswas engineered to secrete a deamidated DQ8 gliadin epitope (LL-eDQ8d) and the induction of antigen-specific tolerance was studied in NOD AB° DQ8 transgenic mice. Tolerance was assessed by delayed-type hypersensitivity reaction, cytokine measurements, eDQ8d-specific proliferation and regulatory T cell analysis. Oral administration of LL-eDQ8d induced suppression of local and systemic DQ8 restricted T-cell responses in NOD AB° DQ8 transgenic mice. Treatment resulted in an antigen-specific decrease of the proliferative capacity of inguinal lymph node cells and lamina propria cells. Production of IL-10 and TGF-β and a significant induction of Foxp3+ regulatory T-cells were associated with the eDQ8d-specific suppression induced by LL-eDQ8d.These data provide support for the development of effective therapeutic approaches for gluten-sensitive disorders using orally administered antigen-secreting LL. Such treatments may be effective even in the setting of established hypersensitivity.