The Changes And Clinical Significance Of Treg And TH17Cells In The Peripheral Blood Of Patients With Lung Adenocarcinoma

Background:CD4+CD25+Foxp3+Treg cells (Treg) and CD3+CD8+IL-17+Thl7(Th17) cells are two new identified CD4+T cells subsets in recent years. Regulatory T cell (Treg) is a functionally immunosuppressive subset of T cells, which play important roles in immunological selftolerance, Treg is characteristic by expressing Foxp3. Th17cell is characterized by expressing ROR γ t and secreting IL-17, which plays critical roles in the development of autoimmunity and allergic reactions. Treg cells and Th17cells share TGF-β in the stage of differential, CD4+T cells tend to differentiate into Treg cell in the high dose of TGF-β, while CD4+T cells incline to differentiate into Th17cells when in the low dose of TGF-β with IL-6/IL-21; as the high affinity binding ligand of CD25, IL-2can promote the differential and expansion of Treg while suppress the function and expansion of Th17cells. On the other hand, Treg can secrete IL-10to suppress the function of th17cells. Previous clinical researches showed that Treg and Th17cells increased in the TILs and PBMCs of a variety of malignant tumors such as ovarian cancer, gastric cancer and prostate cancer, the similar findings were observed in the animal model of lung cancer, but the study of Treg and Th17cells in the human lung cancer is still limited.Purpose: To investigate the frequencies of Treg cells and Thl7cells in patients with lung adenocarcinoma and explore its clinical significance.Methods:Frequencies of Treg cells and Th17cells were detected in39patients with lung adenocarcinoma and20healthy volunteers by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum concentrations of IL-17.14of39patients with lung adenocarcinoma underwent operations, we compared the index between preoperation and postoperation.Results:The frequency of Treg cells in patients with lung adenocarcinoma was significantly higher than that in healthy volunteers (5.11±1.06%vs4.24±0.70%, P<0.01). the frequency of Treg cells in the last-stage was significantly higher than that in the early-stage patients.The frequency of Th17cells in patients with lung adenocarcinoma was significantly higher than that in healthy volunteers (3.01±1.94%vs1.11±0.29%, P<0.01), accompanied by elevated serum concentrations of IL-17. The frequency of Th17cells and the level of IL-17in the last-stage patients were significantly lower than that in the early-stage patients.The frequency of Th17cells in the postoperation patients was significantly lower than that in the preoperation patients, accompanied by descreased serum concentrations of IL-17(P<0.05). Compared with the preoperation patients, The frequency of Treg cells in the the postoperation patients is of no changeThe frequency of Th17cells and IL-17had inverse correlation with the situation of lymph node metastasis and distant metastasis. Conclusion: There are abnormal changes of Treg cells and Th17cells which are related to the tumor load in the peripheral blood of patients with lung adenocarcinoma, the significance of which is still for further research.