The scientists' findings, released this week in the prestigious Proceedings of the National Academy of Sciences journal, showed it is possible to prevent mice that are prone to diabetes from developing the disease by feeding them proteins made by insulin-producing cells of the pancreas.
The next step will be to do clinical testing in people. A team of London scientists is reporting a possible breakthrough in preventing Type I diabetes in individuals considered at high risk for the disease through work with genetically engineered tobacco plants. "There is no other group in the world that has this approach or is as advanced as we are in this area," researcher Dr. Anthony Jevnikar, program director of transplantation, immunity and regenerative medicine at the Lawson Health Research Institute in London, said yesterday, report canoe.ca
Diabetes affects more than 18 million Americans, according to the American Diabetes Association. There are two types of diabetes, type 1 and type 2. Both studies concentrated on type 1 diabetes, once known as juvenile-onset diabetes, which is an autoimmune disease. The immune system perceives normal insulin-producing cells in the pancreas as foreign invaders and mistakenly attacks and destroys these cells. The complete destruction of these cells takes time, but once all are destroyed, the body can no longer produce insulin, and people with this form of the disease must take daily insulin injections.
Weiss says the therapeutic compounds in both studies are designed to stop that process before it begins, or possibly reverse it before the complete destruction of the insulin-producing cells has occurred. He explains that these compounds aren't actually vaccines because they dampen the immune response rather than stimulate it, as most vaccines do.
The first study was a clinical trial of a drug called Diamyd, which helps the body tolerate the "GAD" protein. GAD is found in both the brain and the pancreas. In type 1 diabetes, it appears the immune system attacks the GAD protein in the pancreas. A test has been developed by UCLA researchers to identify antibodies to GAD in the blood, which can help identify who is at risk for developing diabetes. Weiss says not everyone with type 1 diabetes tests positive for GAD antibodies, but a majority do, healthday.com
According to reuters.co.uk type 1 diabetes occurs in genetically susceptible people when a faulty immune response targets and destroys the beta cells in the pancreas that produce insulin. Researchers have now been able to stop this "autoimmune" damage happening in mice.
When administered to mice before they were treated chemically to induce diabetes, ISO-1 completely prevented the onset of high blood sugar levels. And in mice bred genetically to develop diabetes, 90 percent of the animals were protected.
The protection was long lasting; 10 days of treatment prevented diabetes occurring for at least the next 50 days. "That's why we call it a vaccine-like drug," Al-Abed said. Doses 10 times higher than those required to prevent diabetes appeared to be harmless to the animals.
He suggested that people at risk for developing diabetes would perhaps benefit the most from early treatment with ISO-1, and they could be identified by genetic screening at birth or by testing for antibody markers later in life.
His group hopes to start testing ISO-1 in dogs and monkeys within the next year, in preparation for moving into early human safety trials.