In treating autoimmune disease, doctors have long used therapies to suppress the immune system, but now researchers have found a way to prevent type 1 diabetes in mice by actually using a vaccine to boost the immune system and turn it on itself. The technique uses the immune system's regulatory T cells, whose job it is to squelch over-the-top immune responses. The nanovaccine was shown to prevent diabetes in a prediabetic mouse, and brought diabetic mice back to normal blood sugar levels.