A new angle for preventing type 1 diabetes

Researchers have isolated immune cells (T cells) from the pancreas of an organ donor who had type 1 diabetes and shown that the cells recognise a particular part of the insulin molecule.

Dr Stuart Mannering and colleagues at St Vincent’s Institute of Medical Research (SVI) in Melbourne made the discovery through studying a pancreas that had been donated by the family of a 19-year-old man who died due to complications of type 1 diabetes.

Type 1 diabetes is an autoimmune disease in which the body’s immune cells mistakenly destroy the insulin-producing beta cells of the pancreas. Until now it has not been known which exact components of the beta cells the immune system targets in this disease.

The researchers isolated the immune cells from the islets of the donated pancreas - pancreatic islets contain the beta cells, along with several other cell types.

“We caught the immune cells at the ‘scene of the crime’ in the pancreas and then we were able to characterise them: no one has been able to do this in humans before,” Mannering said.

The researchers also showed that the T cells targeted connecting peptide (C-peptide), a short protein that connects the A-chain to the B-chain in the proinsulin molecule.

The existence of cells with these properties has long been predicted and identifying the involvement of the C peptide provides a new target for drug development.

“Manipulating the immune system provides a promising approach to finding a cure for type 1 diabetes, which is the ultimate goal of our research program,” said Mannering.

The study has been published in Diabetes.