A recent study identified unique characteristics in CD8-positive T cells found in blood samples from children with newly diagnosed type 1 diabetes and in autoantibody-positive children who later developed the condition. The research was published in the journal Diabetes.
Type 1 diabetes is an autoimmune disease that often appears in childhood. The onset of type 1 diabetes is linked to the destruction of insulin-producing beta cells in the pancreas by T cells. CD4-positive helper T cells play a role in orchestrating the immune response, while CD8-positive cytotoxic T cells directly contribute to beta cell destruction. Interestingly, a specific CD8-positive T-cell signature in the blood has been associated with a positive response to immunotherapy treatments aimed at delaying the onset of type 1 diabetes.
In this study conducted by Professor Tuure Kinnunen at the University of Eastern Finland, two distinct signatures were identified in a subset of highly differentiated CD8-positive T cells present in children at different stages of type 1 diabetes development. An inflammatory signature, characterized by an increased frequency of T cells producing proinflammatory cytokines like IFN-γ and TNF-α, was observed in children with newly diagnosed type 1 diabetes. In contrast, in autoantibody-positive children at risk of developing type 1 diabetes, there was an increased frequency of T cells expressing the co-inhibitory receptors KLRG1 and TIGIT. Notably, this latter signature resembled the CD8-positive T-cell pattern associated with a positive response to immunotherapy seen in previous research.
“Our findings suggest that children who later progress to clinical type 1 diabetes exhibit a specific CD8-positive T-cell profile detectable in their blood before disease onset. This profile may indicate an immune system response to counter the autoimmune reaction, though it may ultimately be ineffective. In the future, these T-cell signatures could potentially serve as valuable biomarkers for assessing the risk of developing type 1 diabetes and identifying individuals who could benefit from preventive immunotherapy. Further in-depth analysis of these distinct cell types is necessary to enhance our understanding of the type 1 diabetes disease process,” remarked University Teacher Anna-Mari Schroderus, the lead author of the study.
The study utilized samples from the Finnish DIPP follow-up study, a unique initiative that tracks children with a genetic predisposition to type 1 diabetes from birth. Researchers from the universities of Turku, Oulu, and Helsinki, as well as Kuopio University Hospital, were also involved in the research.
