Prevent Disease.com - Study Suggests New Way to Prevent Type 1 Diabetes



		Study Suggests New Way to Prevent Type 1 Diabetes Excerpt By Suzanne Rostler, Reuters Health NEW YORK (Reuters Health) - In a discovery that could lay the groundwork for a preventive therapy for type 1 diabetes, a team of scientists was able to prevent the disorder in a group of at-risk mice by manipulating certain immune system cells. The cells, known as iNKT cells, prevent the immune system from attacking healthy tissue. In type 1 diabetes, the immune system destroys insulin-producing cells of the pancreas, so patients usually must take several daily injections of insulin to survive. Previous studies have shown that a decrease in the numbers of iNKT cells caused diabetes to worsen in pre-diabetic mice. The current report reveals exactly how these cells function. ``Because iNKT cells work in much the same way in mice and humans, techniques for increasing the production of these cells could be the basis of preventive treatments for people with a genetic risk of diabetes,'' Dr. Brian Wilson, the study's senior author, said in a prepared statement. According to the report in the November 20th issue of the Proceedings of the National Academy of Sciences, iNKT cells stop the immune system from attacking healthy tissue in the presence of one particular fat molecule, a-galactosylceramide (a-GalCer). This and other fat molecules are carried by proteins on the surface of immune system components known as dendritic cells. The investigators found that when injected into pre-diabetic female mice, the fat molecule prevented the development of diabetes. And when researchers turned off a gene that regulates the proteins on dendritic cells, the cells were unable to produce a-galactosylceramide. As a result, iNKT cells were not activated and mice developed diabetes. The findings indicate that boosting the supply of iNKT cells, possibly by administering a-galactosylceramide, might help prevent individuals with pre-diabetic conditions such as high blood sugar from developing diabetes. ``Our study suggests a novel mechanism of action that could in theory be used to prevent diabetes and to assist in the acceptance of transplanted islets. Therefore, one could prevent type 1 diabetes in individuals at risk, and help those patients who've lost their islets (the tissue that makes insulin) by replacing the destroyed islets with transplanted ones,'' said Wilson, from Dana-Farber Cancer Institute in Boston, Massachusetts. ``We need to test a-GalCer in clinical trials.'' But it is difficult to estimate how far off such a preventive therapy might be, Wilson noted, since preventing diabetes in mice that are genetically bred to be predisposed to the disease is far easier than preventing the disease in a diverse group of people. ``Despite novel approaches suggested by the animal models, the only way to truly say that a therapy works is to test that therapy in well-controlled clinical trials in human subjects,'' Wilson said in an interview. He and his colleagues estimate that a preventive therapy for type 1 diabetes would help about 1 in 500 people in the US. SOURCE: Proceedings of the National Academy of Sciences 2001;98:13838- Reference Source 89 For more information on how to prevent other diseases, use PreventDisease.com's "Quick Prevention Resources".