Insulin trigger for diabetes

摘要

Type I diabetes occurs when the immune system destroys crucial cells in the pancreas. But what prompts the body to turn against itself so disastrously? It seems that insulin is the key.Autoimmune disorders are caused by aberrant immune responses directed towards the body's own proteins (or 'autoantigens'). In type I diabetes, for example, immune cells called lymphocytes react against and destroy the beta-cells in the pancreas of genetically susceptible individuals (Fig, 1). As these cells produce insulin — the hormone that helps to regulate glucose metabolism — their loss leads to the chaotic blood glucose levels that characterize diabetes and that have serious consequences. How the lymphocytes target beta-cells has been unclear, but work from Nakayama et al. and Kent et al. in this issue (on pages 220 and 224) shows that insulin is itself an auto-antigen that initiates the immune response leading to diabetes.