In humans type 1 diabetes is a serious autoimmune disease caused by the destruction of insulin producing cells in the pancreas by the body's immune system. This leaves diabetics unable to regulate their blood sugar without injections of insulin and at greater risk of developing blindness, heart disease and nerve problems.
In an effort to treat type 1 diabetes small molecules, known as peptides, are being developed to mimic the cells that trigger the autoimmune response. The idea of this immunotherapy is to trick the body into tolerating the cells that it would otherwise attack by "training" the immune system to ignore the insulin producing cells instead of killing them.
Earlier work had shown peptides derived from a protein known as GAD 65, that is expressed in the insulin producing cells in the pancreas, could be used to reduce the incidence of diabetes in mice that are genetically programmed to develop diabetes (NOD mice). This approach was thought to work by inducing a form of "tolerance" and/or by inducing a type of immune response that can be associated with allergic reactions.
Rosetta Pedotti and Maija Sanna and their colleagues from Stanford University investigated whether the injection of relatively large amounts of GAD 65 peptides into NOD mice might be effective in inducing tolerance and whether it caused any side effects.
The researchers injected the GAD 65 peptides into the abdomen of NOD mice each week for 3 weeks. Unfortunately, the potential therapeutic benefits of this treatment could not be evaluated because of an unanticipated side effect of the treatment. When the researc
Contact: Gordon Fletcher