Klotho protein inhibits Treg/TH17 cell-mediated immune escape of cervical cancer cells by regulating TGF-β1/Foxp3/RORγt signaling pathway / 中国肿瘤生物治疗杂志

ABSTRACT

@#Objective: To study the effect of anti-aging Klotho protein on immune escape mediated by regulatory T cells (Treg)/helper T cells 17 (TH17) in mice bearing cervical cancer and its mechanism. Methods: The model of cervical cancer-bearing mice were established, and the control group (normal mice), model group (cervical cancer-bearing mice model), and Klotho treatment group (cervical cancer-bearing mice treated with Klotho protein, 200 ng/d) were set up. The weight of cervical cancer tumors in mice of each group was weighed at 7 and 14 days after treatment respectively, PBMCs were separated at the same time. Flow cytometry was used to detect the changes of T lymphocyte function and the proportion of Treg and TH17 cells in mice. qPCR was used to detect the expressions of Foxp3 and RORγt, the key transcription factors of Treg/TH17 cells, in PBMCs of mice in each group. The changes of IL-17, IL-6, IL10, TGF-β and IL-23 in PBMCs were detected by ELISA. The protein expressions of Klotho, TGF-β, Foxp3 and RORγt in PBMCs of mice were detected by WB assay. Results: On the 14th day, the tumor inhibition rate of the cervical cancer-bearing mice in the Klotho group was significantly higher than that in the Model group [(52.16±8.25)% vs (23.33±6.29)% the model group to be supplemented, P< 0.05). Compared with the Control group, the ratios of Treg and TH17 cells in the lymphocytes of the tumor-bearing mice significantly increased (all P<0.05), the ratios of total T lymphocytes (CD3+), auxiliary/induced T lymphocytes (CD3+CD4+) and immune index (CD3+CD4+/CD3+CD8+ cells) decreased significantly (all P<0.05); in addition, the mRNAexpressions of Foxp3 and RORγt genes, cytokines of IL-17, IL-6, IL-10, TGF-β and IL-23, as well as protein expressions of TGF-β1, Foxp3 and RORγt increased significantly (all P <0.05), while the level of Klotho protein significantly decreased in Model group (P<0.05). Compared with the Model group, the above indicators showed opposite changes in Klotho group (P<0.05), but there was no significant difference with the Control group (all P> 0.05). Conclusion: Klotho protein may inhibit Treg/TH17 cell-mediated immune evasion in cervical cancer-bearing mice by inhibiting TGF-β1/Foxp3/RORγt signaling pathway and exert anti-tumor effect.