A unique therapeutic nanovaccine that successfully reverses diabetes in a mouse model of the disease is providing new insight into diabetes, according to a study published in the online edition of the journal Immunity. It also reveals an aspect of the development of the autoimmune response that may provide a therapeutic strategy for multiple autoimmune disorders.

Type 1 diabetes is a chronic autoimmune disease that results from destruction of insulin-producing pancreatic cells by certain white blood cells, called T cells. Eliminating the extensive repertoire of harmful T cells that attack the pancreas cannot currently be done without also eliminating T cells that protect us from infections and cancer, says Pere Santamaria, from the Julia McFarlane Diabetes Research Centre at the University of Calgary in Alberta.

Santamaria and colleagues wanted to find a way to counteract the harmful autoimmune response without compromising general immunity. They discovered that the body has a built-in mechanism that tries to stop the progression of autoimmune diseases like type 1 diabetes. They say there is an internal tug-of-war between aggressive T- cells that want to cause the disease and weaker T cells that want to stop it from occurring.

The researchers developed a unique nanotechnology-based vaccine that selectively boosted the weak white blood T cells, enabling them to effectively counter the damage caused by their overactive T cell relatives. The vaccine consisted of nanoparticles coated with individual type 1 diabetes-relevant protein fragments bound to self MHC molecules. MHC molecules are used by another type of white blood cell, called an “antigen presenting cell” to “present” antigen to T cells as part of all immune responses.

Using a mouse model of type 1 diabetes, the researchers discovered that their nanovaccine blunted progression of the disease in prediabetic mice and restored normal blood sugar in diabetic mice. Further, nanoparticle displaying human diabetes-relevant complexes restored normal blood sugar levels in a humanized model of diabetes. The authors pointed out that only the disease-generated white blood cells responded to the therapy, so the treatment would be inconsequential in healthy individuals because it would not have nonspecific effects on the immune system.

The researchers say such nanovaccines might hold promise in chronic autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, and others.