London team reports diabetes breakthrough

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.

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. 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. Jevnikar said the proteins fed to the mice, glutamic acid decarboxylase (GAD), are thought to be a trigger factor for Type I diabetes, which is caused by the body’s immune system damaging insulin-producing cells in the pancreas. When the proteins are part of the diet, the immune system is reprogrammed not to attack the cells, a mechanism known as “oral immune tolerance,” Jevnikar said. A major hurdle for the London scientists was producing enough of the GAD proteins and interleukin-4, which is added to the diet to magnify the effect of the GAD proteins. The costs using traditional laboratory methods were prohibitive for the interleukin-4 and not enough GAD proteins could be produced. That was solved by genetically engineering non-nicotine tobacco plants to manufacture the proteins. The mice used in the research were simply fed the genetically modified leaf tissue. If the method works in humans, it will mean people who are identified as susceptible to Type I diabetes could have the proteins added to their diet to prevent the disease, Jevnikar said. It could also be an important protection for diabetics who have received a pancreas transplant, because they remain susceptible to the harmful immune response that originally destroyed their insulin-producing cells, he said. Jevnikar said the advantage of the approach discovered by the London scientists is it doesn’t involve powerful drugs with potentially harmful side-effects. (Source: London Free Press, March 2004)