A Microsphere-based Vaccine Prevents And Reverses New-onset Autoimmune Diabetes

摘要

OBJECTIVE-This study was aimed at ascertaining the efficacy of antisense oligonucleotide-formulated microspheres to prevent type 1 diabetes and to reverse new-onset disease.rnRESEARCH DESIGN AND METHODS-Microspheres carrying antisense oligonucleotides to CD40, CD80, and CD86 were delivered into NOD mice. Glycemia was monitored to determine disease prevention and reversal. In recipients that remained and/or became diabetes free, spleen and lymph node T-cells were enriched to determine the prevalence of Foxp3~+ putative regulatory T-cells (Treg cells). Splenocytes from diabetes-free micro-sphere-treated recipients were adoptively cotransferred with splenocytes from diabetic NOD mice into NOD-scid recipients. Live-animal in vivo imaging measured the microsphere accumulation pattern. To rule out nonspecific systemic immunosuppres-sion, splenocytes from successfully treated recipients were pulsed with β-cell antigen or ovalbumin or cocultured with allogeneic splenocytes.rnRESULTS-The microspheres prevented type 1 diabetes and, most importantly, exhibited a capacity to reverse clinical hy-perglycemia, suggesting reversal of new-onset disease. The microspheres augmented Foxp3~+ Treg cells and induced hypo-responsiveness to NOD-derived pancreatic p-cell antigen, without compromising global immune responses to alloantigens and nominal antigens. T-cells from successfully treated mice suppressed adoptive transfer of disease by diabetogenic splenocytes into secondary immunodeficient recipients. Finally, micro-spheres accumulated within the pancreas and the spleen after either intraperitoneal or subcutaneous injection. Dendritic cells from spleen of the microsphere-treated mice exhibit decreased cell surface CD40, CD80, and CD86.rnCONCLUSIONS-This novel microsphere formulation represents the first diabetes-suppressive and reversing nucleic acid vaccine that confers an immunoregulatory phenotype to endogenous dendritic cells.