Our goal is to identify the earliest immunologically relevant events that trigger autoimmune diabetes. The first detectable inflammatory signature in the NOD mouse is the upregulation of type I interferons and an interferon-inducible gene signature. We reason that understanding the early interferon signature may provide targets for the prevention, treatment, or diagnosis of autoimmune diabetes. The two ubiquitous interferon receptors (IFNAR and IFNGR) upregulate hundreds genes, some shared and some unique to each receptor. We backcrossed the type I interferon receptor onto NOD background to determine the relative contribution of IFNAR-inducible transcripts in type I diabetes induction. In our specific pathogen-free colony, NOD.IFNAR-/- mice developed diabetes at a decreased rate and penetrance from littermate controls. This reduction in incidence was gender independent and NOD.IFNAR heterozygous mice developed diabetes normally. There was a reduction in the number of the immunological infiltrates in the islets of Langerhans of NOD.IFNAR-/- mice from 4-8 wks of age as detected by flow cytometry and immunofluorescence. Concomitantly, there was a reduction in inflammatory gene expression in NOD.IFNAR-/- when compared to controls. Additionally, analysis of the NOD.IFNGR-/- mice showed a decrease in penetrance and kinetics of type I diabetes. Based on this data, we hypothesize that IFNAR and IFNGR induce a common genetic signature that is required for type I diabetes to proceed.

2014