This week several news outlets are reporting on research from the University of Cardiff which suggests germs could be a cause of type 1 diabetes. This comes from an excellent study by a research team in the south Wales University published in The Journal of Clinical Investigation.
The research team have used super intense X-rays to understand the way key molecules come together to activate T cells in type 1 diabetes. T cells are an important part of our immune system and are vital in helping us fight off infections. But in autoimmune conditions like type 1 diabetes, T cells start to destroy our own normal tissue. Why they do this has been very hard to answer.
In this study the Cardiff team have looked at the key molecule that allows T cells to become activated, the T cell receptor. In type 1 diabetes activated T cells attack insulin producing beta cells. The researchers have looked at exactly how the structure of the T cell receptor allows it to interact with the molecules on the surface of insulin producing beta cells, but also what this vital molecule ‘prefers’ to bind to.
They have found that bacterial proteins are a much better ‘fit’ for the T cell receptor which is found on T cells responsible for attacking beta cells. But once activated the T cell can, and does, recognise proteins found on beta cells too.
This clever study indicates that molecules found on bacteria may act almost as an ‘ignition key’ for T cells that can attack beta cells. Once the T cells have been activated, similar shaped molecules found on beta cells can act as a ‘lock pick’, triggering the T cells to destroy these insulin producing cells by accident.