The EXTOD Mechanisms study
The EXTOD Mechanisms study was undertaken to explore the mechanisms through which physical exercise could preserve ß cell function in type 1 diabetes. Peripheral blood samples were taken from people with type 1 diabetes before and after a bout of vigorous exercise and the behaviour of immune cells in these samples studied. In particular, we were interested in the behaviour of a subset of immune cells called CD8 T cells. CD8 T cells are important in the pathogenesis of type 1 diabetes and the pancreatic islet is heavily infiltrated with these cells during the development of the disease.
CD8 T cells mobilised into the peripheral blood in people with type 1 diabetes as well as people without diabetes. However the mobilisation of a small subset of CD8 cells which have markers of memory and are antigen experienced (CD8 EMRA) mobilised less in people with type 1 diabetes than they did in people without diabetes (Curren et al 2019). To read more about this see (Type 1 diabetes impairs the mobilisation of highly-differentiated CD8+T cells during a single bout of acute exercise).
We postulate the reasons for a reduced mobilisation of CD8+ EMRA cells includes differences in blood glucose, adrenaline receptor density, and sequestration of T cells in the pancreas of type 1 diabetes participants.