May 14, 1999—Today, in the journal Science a team of researchers funded in part by the Juvenile Diabetes Foundation International (JDF) published successful results in preventing the development of Type 1 diabetes in mice—a step closer toward the discovery of a vaccine for this deadly disease in humans.

    Type 1, or juvenile, diabetes is an autoimmune disease in which the body’s “killer” T-cells infiltrate the pancreas and destroy the insulin-producing beta cells. Because the body can no longer produce insulin, people with Type 1 diabetes must take up to four shots of insulin every day—just to stay alive. Insulin is in no way a cure for diabetes and its severe complications.

    Since 1991, researchers have known that a protein on the surface of beta cells called glutamic acid decarboxylase (GAD) is an early target of the immune system in the disease process leading to Type 1 diabetes. In the years since, many groups have been working to deepen the understanding of GAD and its role in the initiation of the disease.

    In a research project funded by JDF since 1997, Ji-Won Yoon, Ph.D., at the Julia McFarland Diabetes Research Center at the University of Calgary, Canada, has attempted to determine whether the development of Type 1 diabetes actually requires the expression of GAD to trigger the disease, and whether blocking GAD expression could prevent diabetes from occurring.

    Working with an animal model, the nonobese diabetic (NOD) mouse, which develops a diabetic syndrome resembling human Type 1 diabetes, Dr. Yoon and colleagues selectively blocked the expression of GAD on the pancreatic beta cells, to observe whether diabetes might be prevented. In a new study published today in the journal Science, the team reports that the absence of GAD on beta cells blocks the development of the destructive autoimmune T-cell attack and “is sufficient to nearly completely prevent autoimmune diabetes” in the animal model. According to Dr. Yoon, it may be possible to prevent diabetes with a vaccine that would work in the same way to “re-educate” the immune system.

    Robert A. Goldstein, M.D., Ph.D., JDF’s vice-president of research, described Dr. Yoon’s discovery as a “very important step” toward perhaps eventually developing a preventive diabetes vaccine. “This approach has the promise of modulating the autoimmune response and going toward prevention,” said Dr. Goldstein, “but it is only one brick in the house.” Many further studies will be required to determine how GAD plays its role in initiating diabetes, and experimental vaccines are currently being tried in mice. The hope is that similar immunization of children might one day produce the same results and prevent diabetes.