Recombinant Interferon Alpha-2b is a High-Affinity Antigen for Type 1 Diabetes Autoantibodies

Objectives: Type 1 diabetes results from T-cell-mediated destruction of the beta cells of the pancreas and is associated with several autoimmune phenomena. Many studies have suggested the involvement of interferon alpha (IFN alpha) in the development of type 1 diabetes, but the exact mechanism remains unclear. In this study, the binding of type 1 diabetes antibodies with recombinant interferon alpha-2b (hrIFN alpha-2b), their gene (cIFN alpha-2b gene) and commercially available interferon alpha-2b (IFN alpha-2b) were assessed. Furthermore, we also sought to use anti-hrIFN alpha-2b antibodies as a probe for the estimation of plasma IFN alpha in patients with type 1 diabetes. Methods: The binding specificity of antibodies was analyzed by direct binding, inhibition ELISA and quantitative precipitin titration in 45 patients with type 1 diabetes and 30 control subjects. Competition ELISA was also used to estimate INF alpha in the serum of patients with type 1 diabetes. Results: Antibodies from type 1 diabetes sera, purified in a protein A-agarose matrix, exhibited greater recognition of hrIFN alpha-2b than IFN alpha-2b (p<0.05) and cIFN alpha-2b gene (p<0.001). The relative affinity of type 1 diabetes antibodies for the hrIFN alpha-2b, IFN alpha-2b and cIFN alpha-2b genes was found to be 1.34x10(-7), 1.28x10(-6) and 1.13x10(-6), respectively. The concentration of plasma INF alpha evaluated by induced antibodies was found to be significantly higher than in controls (p<0.05). Conclusions: High binding of hrIFN alpha-2b with IgG from patients with type 1 diabetes might suggest involvement of hrIFN alpha-2b in type 1 diabetes, especially as an antigenic agent. Anti-hrIFN alpha-2b antibodies were shown to be good probes for estimation of plasma INF alpha in patients with type 1 diabetes. (C) 2016 Canadian Diabetes Association.