Identification of a Serum Induced Transcriptional Signature Associated with Type 1 Diabetes in the BioBreeding Rat

Here we report that sera of both spontaneously diabetic BB DRlyp/lyp and diabetes inducible BB DR+/+ rats induce inflammatory signatures in healthy PBMC of non-diabetic Brown Norway (BN) rats, while allogeneic BN sera does not. Consistent with their common T1D susceptibility, transcriptional signatures of both BB sub-strains share identity, including cytokines, immune receptors and signaling molecules. However, like the human T1D signature, the DRlyp/lyp signature, which is associated with progression to diabetes, is differentiated from that of the DR+/+ by induction of many IL-1 regulated genes. Addition of IL-1RA to cultures significantly ablates the DRlyp/lyp signature. Daily treatment of DRlyp/lyp rats with human recombinant IL-1RA significantly delays onset and sera of treated animals do not induce the characteristic IL-1 signature. Consistent with the presence of immune regulation in DR+/+ rats is induction of a signature showing negative regulation of the NF¿B pathway. This study supports prior human investigations of serum that reflect disease processes associated with progression to T1D and add to a growing body of evidence implicating the balance of IL-1 and IL-1RA as key factors influencing the severity and outcome of inflammatory responses.