Metabolically inactive insulin analogue does not prevent autoimmune diabetes in NOD mice
Insulin is widely considered to be a driver antigen in type 1 diabetes in humans and in mouse models of the disease. Therefore, insulin or insulin analogues are candidates for tolerogenic drugs to prevent disease onset in individuals with risk of diabetes. Previous experiments have shown that autoimmune diabetes can be prevented in NOD mice by repeated doses of insulin administered via an oral, nasal or parenteral route, but clinical trials in humans have not succeeded. The hypoglycaemic activity of insulin is dose-limiting in clinical studies attempting tolerance and disease prevention. Here, we aimed to investigate the therapeutic potential of metabolically inactive insulin analogue (MII) in NOD mice.
The tolerogenic potential of MII to prevent autoimmune diabetes was studied by administering multiple i.v. or s.c. injections of MII to non-diabetic 7–12-week-old female NOD mice in three geographical colony locations. The incidence of diabetes was assessed from daily or weekly blood glucose measurements. The effect of MII on insulin autoantibody levels was studied using an electrochemiluminescence-based insulin autoantibody assay. The effect on the number of insulin-reactive CD8+ and CD4+ T lymphocytes in peripheral lymphoid tissue was studied with MHC class I and MHC class II tetramers, respectively.
We found that twice-weekly s.c. administration of MII accelerates rather than prevents diabetes. High-dose i.v. treatment did not prevent disease or affect insulin autoantibody levels, but it increased the amount of insulin-reactive CD4+ T lymphocytes in peripheral lymphoid tissue.
Our data suggest that parenteral MII, even when used in high doses, has little or no therapeutic potential in NOD mice and may exacerbate disease.
KeywordsAutoimmune diabetes Insulin Non-obese diabetic mouse Tolerance
Antigen presenting cell
Hen egg lysozyme
Islet-specific glucose-6-phosphatase catalytic subunit-related protein
Metabolically inactive insulin analogue
Novo Nordisk Research Center
Programmed death-ligand 1
Re-stimulation-induced cell death
We thank L. Zheng and K. Shafer-Weaver (both from Laboratory of Immunology, NIAID, NIH, Bethesda, MD, USA) for their scientific advice and B. Chao (Laboratory of Immunology, NIAID, NIH, Bethesda, MD, USA), A. Bel Hani and Y. Manenkova (La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA) for technical assistance. We thank the NIAID Research Technologies Branch for producing the HEL11-25 and insulin B9-23 peptides and the NIH Tetramer Core Facility at Emory University, Atlanta, GA, USA for the tetramers.
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
This research was supported by the Division of Intramural Research, NIAID, Clinical Center and National Human Genome Research Institute, NIH. JG was supported by a fellowship grant from the Sigrid Juselius Foundation and by a grant from the Emil Aaltonen Foundation. Wellstat Immunotherapeutics supported this research with Cooperative Research and Development Agreement (CRADA) C-087-2006 (2006-0203) and Wellstat Diagnostics with CRADA C-022-2006 (2006-0369). The study was also funded in part by Novo Nordisk.
Duality of interest
MvH, JLV, PPP, CBG and MNP are employed or affiliated with Novo Nordisk. All other authors declare that there is no duality of interest associated with their contribution to this manuscript.
JG, MvH, JLV, PPP and MJL designed the experiments. JG, JLV, PPP, MNP, PFM and CBG performed the experiments and analysed the results. JG, PPP, MNP, PFM and JLV drafted the manuscript. All authors performed critical analysis of the manuscript and approved the final version to be published. MJL is a guarantor of this study and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.