Critical role of gliadin for both enteropathy and insulitis development in NOD-DQ8 mice

GALIPEAU H; RULLI E; ARAYA R; JURY J; HUANG X; MURRAY J; DAVID C; MCCOY K; CHIRDO F; VERDU E

Chicago

Congreso; Digestive Disease Week; 2011

Critical role of gliadin for both enteropathy and insulitis development in NOD-DQ8 mice Heather Galipeau1, Ezequiel Rulli2, Romina Araya2, Jennifer Jury1, Xianxi Huang1, Joseph A. Murray3, Chella David4, Kathy D. McCoy1, Fernando Chirdo2, Elena F. Verdu1. Introduction: Type 1 diabetes (T1D) results from the autoimmune destruction of the insulin-producing beta cells in the pancreas and is associated with celiac disease (CD). Exposure to environmental antigens in individuals with altered immuno-regulatory mechanisms is hypothesized to increase susceptibility to disease. The exact environmental antigens remain unknown, but gliadin, the protein in cereal-gluten that causes CD, has been suggested to play a role in the T1D pathogenesis. The objective of this study was to investigate the role of gliadin in the development of enteropathy and insulitis in NOD-DQ8 mice, a mouse model that resists spontaneous development of diabetes. Methods: Male NOD-DQ8 mice were treated with anti-CD25 antibodies to induce immune dysregulation, followed by oral gavage of gliadin or bovine serum albumin (BSA) plus cholera toxin. Control NOD-DQ8 mice were treated with anti-CD25 alone, gliadin alone, or neither. Intestinal barrier function was assessed using Ussing chambers. Enteropathy and insulitis were assessed by histological analysis. CD4+ T-cells were isolated from the pancreatic lymph nodes (PLN) of anti-CD25 plus gliadin-sensitized mice and naïve control mice and cultured in the presence of gliadin, BSA, or media. Cell proliferation and cytokine production were measured. Results: Gliadin-sensitization in NOD-DQ8 mice resulted in a 27% increase in tissue conductance compared to controls. In addition, gliadin-sensitized mice developed a Marsh II lesion in the small intestine, but no insulitis. Administration of anti-CD25 antibodies before gliadin-sensitization induced a 53% reduction of CD4+CD25+Foxp3+ T-cells and led to severe insulitis, with a 50% increase in insulitis scores. Anti-CD25 antibody treated only or anti-CD25 plus BSA-sensitized mice did not develop barrier dysfunction or insulitis. CD4+ T-cells isolated from PLN of mice that developed insulitis showed increased proliferation and proinflammatory cytokine production towards gliadin but not towards the unrelated antigen, BSA. Conclusions: Gliadin-sensitization induced mucosal dysfunction and a Marsh II-like enteropathy in NOD-DQ8 mice. However, development of insulitis in NOD-DQ8 mice required oral gliadin-sensitization and partial systemic depletion of CD25+Foxp3+ T-cells. The presence of T-cells that responded to gliadin in the PLN of mice that develop insulitis suggests that gliadin-specific T-cell reactivity may play a role in the development of insulitis in NOD-DQ8 mice. This animal model will be useful to investigate the pathways by which gliadin can induce intestinal and extra-intestinal inflammation.