Role of 'killer cells' in diabetes identified

London, Jan 16 (ANI): Scientists have shed new light on the role of 'killer cells' in the development of Type 1 diabetes.

They have uncovered that killer T-cells in the human body, which help protect us from disease, can inadvertently destroy cells that produce insulin.

The study provides the first evidence of this mechanism in action and could offer new understanding of the cause of Type 1 diabetes.

Professor Andy Sewell, an expert in human T-cells from Cardiff University's School of Medicine and diabetes experts from King's College London isolated a T-cell from a patient with Type 1 diabetes to view a unique molecular interaction, which results in the killing of insulin-producing cells in the pancreas.

"Type 1 diabetes is a result of the body's own immune system attacking and destroying the cells in the pancreas that manufacture the hormone insulin. Insulin controls blood sugar levels and a lack of insulin is fatal if untreated," said Professor Sewell.

"The mechanism by which the body attacks its own insulin producing cells in the pancreas is not fully understood. Our findings show how killer T-cells might play an important role in autoimmune diseases like diabetes and we've secured the first ever glimpse of the mechanism by which killer T-cells can attack our own body cells to cause disease," he added.

The team now hope that by gaining a better understanding of this process it will put them in a much stronger position to devise new ways to prevent or even halt the disease.

The study found that the killer T-cell receptor utilises an abnormal mode of binding in order to recognise cells producing insulin.

This unusual binding is thought to allow the T-cell to survive the culling process designed to rid the body of autoreactive T-cells.

The structure of the killer T-cell receptor bound to the insulin peptide shows that the interaction is highly focused on just a small part of the molecule.

The finding was published in Nature Immunology.

In a further study published in the Journal of Biological Chemistry the same Cardiff and King's team has shown that this focused binding mode allows this T-cell receptor to respond to over 1.3 million other peptides of different molecular shape.

This ability to bind peptides with a multitude of different shapes may provide a clue as to how autoimmune diseases are initiated. It is possible that this T-cell was raised to fight an infection via one of the other 1.3 million peptides it can recognise but then inadvertently also recognised insulin once it had been put on 'red alert' by this infection. (ANI)