Virtual Optimization of Nasal Insulin Therapy Predicts Immunization Frequency to Be Crucial for Diabetes Protection

Abstract Objective - Development of antigen-specific strategies to treat or prevent type 1 diabetes has been slow and difficult due to the lack of experimental tools and defined biomarkers that account for the underlying therapeutic mechanisms. Research Design and Methods - The type 1 diabetes PhysioLab® platform, a large-scale mathematical model of disease pathogenesis in the NOD, was employed to investigate the possible mechanisms underlying the efficacy of nasal insulin B:9-23 peptide therapy. The experimental aim was to evaluate the impact of dose, frequency of administration and age at treatment on Treg induction and optimal therapeutic outcome. Results - In virtual NOD mice treatment efficacy was predicted to depend primarily on the immunization frequency and stage of the disease and to a lesser extent on the dose. While low-frequency immunization protected from diabetes due to Treg and IL-10 induction in the pancreas 1-2 weeks after treatment, high-frequency immunization failed. These predictions were confirmed with wet-lab approaches, where only low-frequency immunization started at an early disease stage in the NOD resulted in significant protection from diabetes by inducing IL-10 and Treg. Conclusions - Here, the advantage of applying computer modeling in optimizing the therapeutic efficacy of nasal insulin immunotherapy was confirmed. In silico modeling was able to streamline the experimental design and to identify the particular time frame at which biomarkers associated with protection in live NODs were induced. These results support the development and application of humanized platforms for the design of clinical trials, i.e. for the ongoing nasal insulin prevention studies.