Insulin-dependent, or Type I, diabetes is one of the most common and potentially devastating chronic diseases. Yale investigators took a step toward unlocking the mechanisms behind it by creating an animal model showing one gene can cause the disease, while another gene can provide resistance to it. The findings were made when the researchers induced diabetes in a mouse with HLA-DQ8 in the presence of the B7 co-stimulatory molecule. HLA-DQ8 is a human gene long suspected of being a factor in the disease. They also prevented diabetes from developing in a transgenic mouse expressing the HLA-DQ6 gene.
Type I diabetes is an autoimmune disease in which the body produces an immune reaction that attacks its own tissues, eventually preventing the pancreas from producing insulin, which is necessary for the body to metabolize sugars. Researchers have previously shown in the laboratory that HLA-DQ8 is associated with diabetes. The study’s lead author, immunologist Li Wen, M.D., Ph.D., assistant professor of medicine, said: “This is the first time it has been shown in vivo that HLA-DQ8 causes Type I diabetes and HLA-DQ6 confers resistance. Not only can we now study the molecular mechanism in more detail in a living organism, this is also very important for work in preventing and even curing the disease.”
The study was published January 3 in the Journal of Experimental Medicine. Wen and colleagues are now looking further into the roles of both genes in diabetes.