Elevated TIM3 expression of T helper cells affects immune system in patients with myelodysplastic syndrome.

T cell immunoglobulin and mucin domain 3 (TIM3) expression is associated with immunosuppression and clinical outcomes in many diseases. However, the specific mechanism of TIM3 in immune system has not been clarified. In order to illustrate the mechanism of TIM3 in immune system, we analyzed the expression, function and regulation of TIM3 in T helper (Th)1 cells, Th2 cells, Th17 cells and regulatory T cells (Treg) through flow cytometry in patients with myelodysplastic syndrom (MDS). Our data showed elevated proportion of Th2 and Treg cells, while the proportion of Th1 and Th17 cells decreased in patients with MDS (p<0.05) and the expression of TIM3 increased in Th1, Th17 and Treg cells in patients with MDS when compared with expression in control patients (p<0.05). The secretion of transforming growth factor-β in TIM3+Treg cells decreased in patients with MDS. These findings suggested that TIM3 might affect immune helper systems by regulating Treg cells and related immune cells. Therefore, studying the role of the TIM3 pathway in MDS is necessary and may help to provide a new way to explore the pathogenesis and treatments of MDS.