Of all the quests that researchers have undertaken in search of a cure or decisive treatment for type 1 diabetes, the search for a vaccine has to be the boldest. But how would you develop such a vaccine, and how would it work?
Massimo Trucco, MD, an immunologist affiliated with the University of Pittsburgh School of Medicine and a director of the Juvenile Diabetes Foundation, thinks he may be on to something: a way to make the body thwart attacks by immune system killer T cells on the pancreatic beta cells that produce insulin.
What goes wrong in people with type 1 diabetes is that certain white blood cells, called dendritic cells, wrongly tell the T cells that beta cells are invaders. The T cells, consequently, kill the beta cells. (Think of dendritic cells as conniving little playground tattletales who loves to get other kids in trouble with the teachers by spreading misinformation.)
Dr. Trucco’s approach is to alter molecules on the dendritic surface that the cells use to communicate. By garbling up the information that the dendritic cells deliver to the immune system, he can stop the continual T cell attacks that eventually destroy all pancreatic beta cells.
Dr. Trucco’s experiments with mice, injecting them with “reprogrammed” dendritic cells from their own bodies, have worked to completely stop T cell attacks. He is currently working with 15 adults with type 1 diabetes to test a vaccine, derived from their blood, in which their dendritic cells have been altered. He injects the vaccine into the skin near the pancreas, and the cells work their way to the organ to begin offering their new message.
If the trial with adults goes well, Dr. Trucco will then begin testing the effects of reprogrammed dendritic cells on children. Also in the works is research on ways to alter dendritic cells without having to remove them from patients and then re-inject them, perhaps by using drugs.
Dr. Trucco’s approach gets around a long-standing problem in the treatment of diabetes. Because it is an autoimmune disease, it could theoretically be thwarted by suppressing a patient’s immune system. In real life, however, such an approach would leave type 1 patients open to infection and opportunistic diseases.
For many long-time type 1 patients, the attacks on their beta cells over the years have left them with no realistic hope of recovering the ability to produce insulin. But if a vaccine could be developed that specifically targets the misbehaving dendritic cells, it could help newer type 1’s without having to shut down the entire immune system.
This Associated Press story gives more details about Dr. Trucco’s research.