Oral administration of PDX1 confers protection against insulitis in the non-obese diabetic (NOD) mice

Type 1 diabetes is a T cell-mediated organ-specific autoimmune disease. Antigen-specific immune intervention allows the selective targeting of autoreactive T cell, while leaving the remainder of the immune system intact. However, immune intervention for type 1 diabetes has not yielded perfect results clinically. In our paper published previously, we asked whether pancreatic duodenal home box 1 (PDX1) is a target of anti-islet autoimmunity in type 1 diabetes. In this experiment, we assessed the therapeutic effect of oral administration of PDX1 on diabetes development of 4-week-old non-obese diabetic (NOD) mice. The results indicate that PDX1 immunization is an effective intervention strategy for delaying the onset of diabetes in NOD mice in association with: 1) reduced insulitis; 2) suppression of destructive autoreactive T cells; 3) augmentation of regulatory T cells; 4) a shift in cytokine production. The present observations suggest that immunization with PDX1 modulates immune cell responses in NOD mice, raising the possibility that it is beneficial in ameliorating autoimmune destruction of beta-cells and delaying type 1 diabetes development clinically.