Using Antigen Mimicry to Prevent Diabetes

Antigen mimicry may become an effective strategy in preventing type 1 diabetes.

Researchers at the Institute of Diabetes Research, part of the Helmholtz Zentrum Munchen in Neuherberg, Germany, examined the effect of modified insulin mimotypes on the immune system. Mimotypes are macromolecules such as peptides that mimic the structure of an epitope, the part of an antigen that the immune system recognizes.

Carolin Daniel, PhD, who directed the study had previously found that insulin mimetopes were significantly more efficient in inducing a tolerance toward insulin through regulatory T cells, compared with natural epitopes. In mouse models, giving low doses of the insulin mimetopes halted development of type 1 diabetes.

In this study, her team created a “humanized mouse model” to further test the results of that study. The mice used lack their own immune system, but have reconstituted systems made with human stem cells.

"In particular, we wanted to find out whether we can induce the protective regulatory T cells to produce a tolerance of the body against insulin, if we bring them into contact with our novel peptides," said Daniel.

In the humanized mouse models, the vaccine worked again, indicating that optimizing human insulin mimetopes could become an effective tool to prevent type 1 diabetes.

"In fact, we were able to show that the new vaccine efficiently stimulates the regulatory T cells, which then can impede the attack of the immune system on the insulin-producing cells," said lead author Isabelle Serr, a doctoral candidate at the Technische Universitat Munchen, in Neuherberg.

Ultimately, the team would like to develop the method as a preventive treatment in children who are at high risk for developing type 1 diabetes. The report appears in the March 15 issue of Nature Communications.