Hematopoietic transplants for disease suppression and cure in type 1 diabetes.

Recent clinical studies have demonstrated the capacity of immunosuppressive therapy to delay progression of inflammatory insulitis in type 1 diabetes (T1D). The procedure includes depletion of pathogenic cells by immunosuppressive therapy and support of recovery by reinfusion of autologous hematopoietic progenitors. The short-term outcome of these clinical transplants is similar to the predictions drawn from NOD mice: debulking of diabetogenic cells is ineffectively achieved by immunosuppressive therapy, and resetting of immune homeostasis does not restrain autoimmunity. Murine models indicate that allogeneic transplants are potentially curative, through restored mechanisms of negative regulation that are effective in continuous and indefinite suppression of autoimmunity.