Erschienen in:
01.11.2012 | Article
Interleukin-15 plays an essential role in the pathogenesis of autoimmune diabetes in the NOD mouse
verfasst von:
D. Bobbala, X.-L. Chen, C. Leblanc, M. Mayhue, J. Stankova, T. Tanaka, Y.-G. Chen, S. Ilangumaran, S. Ramanathan
Erschienen in:
Diabetologia
|
Ausgabe 11/2012
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Abstract
Aims/hypothesis
IL-15, induced by innate immune stimuli, promotes rheumatoid arthritis and inflammatory bowel disease. However, its role in autoimmune type 1 diabetes is unclear. Our aim is to define the role of IL-15 in the pathogenesis of diabetes in the NOD mouse model.
Methods
We generated NOD.Il15
−/− mice expressing a polyclonal repertoire of T cell antigen receptor (TCR) or a transgenic TCR and monitored diabetes onset and insulitis. NOD Scid.Il15
−/− (full name NOD.CB17-Prkdc
scid
/NCrCrl) and NOD Scid.gamma (full name NOD.Cg-Prkdc
scid
Il2rg
tm1Wjl
/SzJ) mice were used to distinguish the requirement for IL-15 signalling in CD8+ T cells and antigen-presenting cells (APCs) to induce disease. We examined the effect of blocking IL-15 signalling on diabetes onset in NOD mice.
Results
At 7 months of age, more than 75% of the NOD Il15
−/− female mice remained diabetes free compared with only 30% in the control group. Diabetes incidence was also decreased in 8.3-NOD (full name NOD Cg-Tg[TcraTcrbNY8.3]-1Pesa/DvsJ).Il15
−/− mice expressing a highly pathogenic transgenic TCR on CD8+ T cells. Adoptive transfer of splenocytes from diabetic NOD and 8.3-NOD donors induced disease in NOD Scid recipients but not in NOD Scid.Il15
−/− or NOD Scid.gamma mice. Transient blockade of IL-15 signalling at the onset of insulitis prevented diabetes in NOD mice.
Conclusions/interpretation
Our results show that IL-15 is needed for the initial activation of diabetogenic CD8+ T cells as well as for sustaining the diabetogenic potential of antigen-stimulated cells, acting on both CD8+ T cells and on APCs. Our findings demonstrate a critical role for IL-15 in the pathogenesis of autoimmune diabetes and suggest that IL-15 is a promising therapeutic target.