TGFβ及IL-10通过Eomes介导肝细胞癌浸润性γδT细胞功能受损的机制研究

The immunosuppressive network in the tumor milieu is one ofthe major obstacles for the anti-tumor immunity. Previously, we found that thefunction of the hepatocellular carcinoma (HCC) infiltrating γδ T cells was significantly impaired; TGFβ and IL-10 can suppress the maturational differentiation and IFN-γ secretion of γδ T cells. But the mechanism through which TGFβ and IL-10 mediate the suppression of γδ T cells was undetermined. Eomes, one of the key transcriptional factors, regulate the maturational differention and effector function of multiple effector cells, such as CD8+ T cells and natural killer cells. Our microarray study showed that Eomes was significantly downregulated in HCC-infiltrating γδ T cells compared with peritumoral γδ T cells. We speculate that TGFβ and IL-10 mediate the functional impairment of γδ T cells through the down-regulation of Eomes. Taking advantage of co-culture, signal pathway analysis and in vivo analysis, we try to illuminate the mechanism underlying TGFβ and IL-10 mediated functional suppression of γδ T cells in HCC, as well as the detailed molecular mechanisms. Increasing the Eomes expression in vitro can enhance the anti-tumor function of γδ T cells in vivo, remitting or even reversing theimmunosuppressive status in tumor.

肿瘤局部的免疫抑制网络是机体抗癌免疫失败的主要原因之一。我们已发现，肝细胞癌浸润性γδT细胞功能受损，TGFβ及IL-10显著抑制γδT细胞效应功能的发挥；然而机制尚不明确。Eomes是促进效应细胞成熟分化及效应功能发挥的关键转录因子，其在肝细胞癌浸润性γδT细胞中显著下调。我们推测，TGFβ及IL-10能通过下调Eomes表达介导γδT细胞功能受损。借助共培养、信号通路分析及体内研究，拟阐明TGFβ及IL-10通过Eomes介导肝细胞浸润性γδT细胞成熟分化障碍及效应功能抑制。上调Eomes将有助于增强肝癌局部γδT细胞的抗癌效应，减轻甚至逆转肝癌局部的免疫抑制状态。

肿瘤局部的免疫抑制网络是机体抗癌免疫失败的主要原因之一。我们前期发现，肝细胞癌浸润性γ δ T 细胞功能受损， TGFβ 及 IL-10 显著抑制γ δ T 细胞效应功能的发挥；然而机制尚不明确。 Eomes 是促进效应细胞成熟分化及效应功能发挥的关键转录因子，其在肝细胞癌浸润性γ δ T 细胞中显著下调。我们推测， TGFβ 及 IL-10 能通过下调 Eomes 表达介导γ δ T 细胞功能受损。本项目在既往研究工作基础上，研究了TGF-β及IL-10对γδT细胞的抑制作用，及Eomes在这一过程中所起的关键转录因子作用。通过研究发现：1、TGF-β及IL-10体外显著抑制γδT细胞的成熟分化及效应细胞功能；2、TGF-β及IL-10体外显著抑制γδT细胞中Eomes表达；3、Eomes在γδT细胞的效应功能中发挥关键转录因子作用。4、初步发现了Eomes介导γδT细胞分化及功能受损的潜在信号通路。在完成以上工作的同时，我们研究了系统性炎症评分预测肝细胞癌预后的价值，发现了通过组合术前及术后中性粒细胞与淋巴细胞比例建立新的系统性炎症评分以用于预测肝细胞癌患者术后预后。此外探讨了肝细胞癌内IL-35的表达及其与CD39+Foxp3+Treg浸润的相关性及预后价值。目前的研究成果有助于进一步理解γ δ T 细胞在肝癌肿瘤免疫微环境中的作用，以及免疫抑制分子（包括TGF-beta、IL-10、IL-35）及细胞（Treg细胞）促癌作用发挥的潜在机理。