The profile of Th17 subset in glioma

The Th17 cell subset is involved in many autoimmune and infectious pathologies. It is also associated with the tumorigenesis process and poor prognosis of certain tumors. However, its expression and function in glioma cases remain unclear. We measured the percentage of Th17 cells in peripheral blood mononuclear cells (PBMCs) and compared the concentrations of relevant cytokines in the serum of 35 glioma patients and 20 healthy donors. Protein, mRNA, and levels of Th17-relevant cytokines in 24 glioma tissues and 5 cerebral trauma tissues were also assessed. We evaluated whether Th17-relevant cytokines were associated with the clinical stages of glioma. The results showed that there were no significant differences in the volume of Th17 cells in PBMCs and serum concentrations of interferon (IFN)-γ, interleukin (IL)-17, IL-6, IL-23, and TGF-β between glioma patients and healthy donors nor did these differences exist in patients with different clinical stages of glioma. Different expression patterns of Th17-relevant cytokines were observed in glioma tissues when compared to trauma tissues. High mRNA-positive ratios of IL-17 (19/24) and retinoid-related orphan receptor (RORC) (18/24) were observed in glioma tissues, but not in trauma tissues. Positive ratios of transforming growth factor (TGF)-β were higher in trauma tissues and glioma grade II than in glioma grade IV. IL-6, IFN-γ, and IL-1β showed high positive ratios, but showed no significant differences between trauma tissues or grades of glioma. None of the glioma and trauma tissues was positive for IL-23. High positive ratios of IL-17 in glioma tissue were confirmed via analysis of immunohistochemical staining. The results demonstrated that IL-17 and other Th17-relevant cytokines could be expressed in glioma tissues. IL-17 expression, the hallmark of Th17 cell subset, may play an important role in glioma tumorigenesis and progression.