CD39 expression on Treg and Th17 cells is associated with metabolic factors in patients with type 2 diabetes

Th17 cells are involved in the pathogenesis of multiple inflammatory diseases such as type two diabetes (T2D). CD39⁺ Treg cells have been implicated as responsible for suppressing Th17 cells. The aim of this study was to evaluate the number and function of CD4⁺CD25^highCD39⁺ Treg and Th17 cells in peripheral blood mononuclear cells (PBMC) from T2D patients and healthy control subjects. The Th17 cells were detected in PBMC under culture with human anti-CD3/CD28 and PMA/ionomycin and the levels of IL-17 were assessed by ELISA and qPCR. The T2D patients with obesity showed significantly lower percentages of CD39⁺ Treg cells. A negative correlation between CD39⁺ Treg cells and weight, and body mass index was detected. In contrast, the low levels of CD4⁺IL-17⁺ cells in overweight and obese T2D patients showed a positive correlation with glucose and HbA1c. Additionally, we found a subpopulation of Th17 cells that express CD39 and were correlated with glucose and HbA1c. Our findings suggest that the expression of CD39 on Treg cells and also in CD4⁺IL-17⁺ cells from T2D patients is related to hyperglycemia as well as to overweight and obesity and therefore may participate as a modulator of the effector capacity of Th17 cells.