Reversal of Experimental Autoimmune Diabetes With an sCD39/Anti-CD3 Treatment

Extracellular (e)ATP, a potent proinflammatory molecule, is released by dying/damaged cells at the site of inflammation and is degraded by the membrane ectonucleotidases CD39 and CD73. In this study, we sought to unveil the role of eATP degradation in autoimmune diabetes. We then assessed the effect of soluble CD39 (sCD39) administration in prevention and reversal studies in NOD mice as well as in mechanistic studies. Our data showed that eATP levels were increased in hyperglycemic NOD mice compared with prediabetic NOD mice. CD39 and CD73 were found expressed by both α- and β-cells and by different subsets of T cells. Importantly, prediabetic NOD mice displayed increased frequencies of CD3+CD73+CD39+ cells within their pancreata, pancreatic lymph nodes, and spleens. The administration of sCD39 into prediabetic NOD mice reduced their eATP levels, abrogated the proliferation of CD4+- and CD8+-autoreactive T cells, and increased the frequency of regulatory T cells, while delaying the onset of T1D. Notably, concomitant administration of sCD39 and anti-CD3 showed a strong synergism in restoring normoglycemia in newly hyperglycemic NOD mice compared with monotherapy with anti-CD3 or with sCD39. The eATP/CD39 pathway plays an important role in the onset of T1D, and its targeting might represent a potential therapeutic strategy in T1D.