An Experimental Study On Th17 Cells And Human Medulloblastoma

Medulloblastoma is a commonly malignant tumor of the puerile cerebellum. Patients with medulloblastomas after primary therapy have a particularly poor prognosis, with a median survival of less than 6 months; the 2-year survival rate among these patients is approximately 9%. Medulloblastoma is one of the difficult problems for resolving in neurosurgery. Current therapies have serious short-term and long-term adverse effects, including postoperative mutism, neurocognitive deficits. Recently, a new member of the CD4+ effector T-cell family (Th17 cells) has substantially advanced our understanding of T cell-mediated immunity. These cells are characterized as preferential producers of IL-17 and IL-23 in humans. Although human Th17-cell development is less well understood, IL-23 have been shown to collectively mediate the differentiation of human Th17 cells in vitro. Recently some findings suggest Th17 cells may also play an active role in tumor pathogenesis.PartⅠObjective:In this study, we want to find the relationship between the Th17 cells and medulloblastoma.Method and material:Peripheral blood was collected from 23 patients with medulloblastoma and 17 healthy volunteers. Peripheral blood mononuclear cells (PBMCs) were obtained by Ficoll-Hypaque density centrifugation. Then the PBMCs were cultured for 24 hours. We determined the prevalence of Th17 cells in peripheral blood by flow cytometric analysis. The concentrations of IL-17 and IL-23 cytokines in serum were measured by ELISA.Result:The proportion of peripheral blood Th17 cells in medulloblastoma patients was significantly higher than that in healthy donors (2.7±1.4% vs 0.8±0.3%, p< 0.01, the cytokines concentrations were significantly higher in patients than that in control subjects (IL-17:79.5±37.7 pg/ml vs 15±9.1 pg/ml, p<0.01;IL-23: 293±132pg/ml vs 102±55 pg/ml, p< 0.01).Part II Objective:To study Th17-related factors (IL-17, IL-23, and RORC) in tumor tissues from patients with medulloblastoma and evaluated the potential association of Th17 cells with human medulloblastoma.Method:13 tumor tissues were collected during surgery. Tumor-infiltrating lymphcytes were obtained by Ficoll-Hypaque density centrifugation. Control group cotained 13 cases. Then the tumor-infiltrating lymphcytes were cultured for 24 hours. The PBMCs were cultured for 24 hours. We determined the prevalence of Th17 cells in tumor-infiltrating lymphcytes by flow cytometric analysis. Th17-re-lated factors (IL-17, IL-23pl9, and RORC) in tumor-infiltrating lymphcytes and autologous normal tissues was measured by RT-PCRResult:Our data indicated an increased prevalence of Th17 cells in Medulloblastoma-infiltrating T cells s in comparison to controls (6.7±2.4% vs 1.7±2.1%, p< 0.01). IL-17 and RORC mRNA expressions were synchronically detected in 6 out of the 13 samples. Increased expression of IL-23p19 mRNA was observed in 9 out of 13 specimens. No expression was detected in autologous normal tissues.PartⅢObjective:To study the activity of IL-17 in immunologic reconstitution BALB/c nu/nu mouse bearing Medulloblastoma and detecte the expression level of IL-23, IL-6, CCL-2, CCL-20 in tumorsMethod:IL-17 was added to immunologic reconstitution BALB/c nu/nu mouse bearing Medulloblastoma. The mouse's survival time and the tumors weights were observed. We also detected the expression level of IL-23, IL-6, CCL-2, CCL-20 in tumors by Westle blot and Real-time PCR.Result:The survival times of IL-17 adding group were prolonged and the growing of the tumor of experimental group was retarded.the expression level of IL-23, IL-6, CCL-2, CCL-20 of IL-17 adding group was ascent.Conclusion:(1) Th17 cells and relative cytokines IL-17, IL-23 may take a role in the development of medulloblastoma. (2) Th17 cells and related factors (IL-17, IL-23, and RORC) may take a role in the development of medulloblastoma. (3) IL-17 may play a role in the antineoplastic immunity in medulloblastoma.