Tim-3 on Peripheral CD4+ and CD8+ T Cells Is Involved in the Development of Glioma

Tim-3 acts as a negative regulatory molecule and plays a critical role in immune tolerance. The purpose of this study was to investigate the expression of Tim-3 on peripheral CD4(+) and CD8(+) T cells in glioma. A total of 30 newly diagnosed glioma patients and 30 healthy controls were recruited and leukocytes from peripheral blood mononuclear cells were analyzed for Tim-3 surface expression by flow cytometry. Plasma tumor necrosis factor-alpha (TNF-alpha) was also measured. Data showed that expression of Tim-3 was significantly increased in both CD4(+) and CD8(+) T cells in glioma patients than in controls (pp<0.001, respectively). Patients with a higher tumor grade revealed further elevated Tim-3 expression in CD8(+) T cells compared with those with a lower tumor grade. Also, the Karnofsky score of patients was negatively correlated with the percentage of Tim-3(+)CD8(+) T cells in glioma patients (p=0.007). In addition, an inverse correlation was observed between the plasma level of TNF-alpha and Tim-3(+)CD4(+) T cells (p=0.005) or Tim-3(+)CD8(+) T cells (p<0.001) in glioma patients. Our results suggested that Tim-3 may be involved in the development of glioma.