Th22/Th17协同通过STAT3通路促进HBV相关性肝癌发生发展

The immune response caused by HBV infection is the key to the occurrence of hepatocellular carcinoma (HCC). Lymphocytes are the main body of immune response, Th22 and Th17 are two newly discovered CD4 helper cell subsets, the recent independent each other reseach found that Th22 and Th17 may be involved in the pathogenesis of hepatitis B, and both can promote HCC progression. Our preliminary study found that Th17 cells and IL-17 involved in the transformation of hepatitis and HCC, and the development of liver cancer. In addition, we also found that IL-22 + T cells in HCC tissue expression increased, cell experiments show that IL-22 can promote the proliferation of liver cancer cells. And both are inflammatory factors, studies have shown that both of them can trigger inflammation through STAT3 pathway. In addition, studies have shown that both also can promote tumor progression through the STAT3 pathway. we speculate that both Th22 and Th17 cells play a coordinating role in the process of tumor development. The aim of this project is to study the role of Th22 and Th17 cells in the development and progression of HCC in the context of HBV infection through the STAT3 pathway.

HBV的感染所引起的炎症免疫反应是导致肝癌发生的关键所在。淋巴细胞是免疫反应的主体，Th22及Th17是两种新近发现的CD4辅助细胞亚群，近期各自独立的研究发现Th22及Th17可能参与了乙肝的发病机制，并且两者均可促进肝癌进展。我们前期研究发现Th17细胞及IL-17参与了肝炎肝癌转化以及肝癌发展。此外，我们预实验中也发现IL-22+T细胞在肝癌组织表达增加，细胞实验表明IL-22能促进肝癌细胞增殖。并且两者均为炎症因子，有研究表明均可通过STAT3路径触发炎症反应。另外有研究表明两者在肿瘤发生和发展中也均通过STAT3通路促进肿瘤进展，我们推测两者在肿瘤发生发展过程中起协调作用。本项目旨在通过组织水平、细胞水平及活体水平三个层次的实验深入研究Th22与Th17细胞协同通过STAT3通路促进HBV感染背景下的肝癌发生发展过程中的作用，阐述其可能机制。

HBV相关肝细胞癌组织中聚集过多的Th22及Th17细胞，其产生的主要细胞因子IL22及IL17与肝细胞癌的发生发展关系密切。Th22/Th17在HBV相关肝细胞癌进展中的作用机制需要进一步阐明。健康人被采集外周血以分离获得Th22及Th17细胞，分别与人肝癌细胞HepG2和表达HBV病毒的人肝癌细胞HepG2.2.15共培养。观察Th22细胞IL22及Th17细胞IL17生产情况，以及肝癌细胞的增殖、凋亡情况。使用western blotting检测p-STAT3、Cyclin D1、Bcl2、cleaved caspase 3蛋白表达水平。结果显示，相比HepG2细胞，Th22细胞共培养能够明显促进HepG2.2.15细胞增殖，抑制其凋亡，并显著上调HepG2.2.15细胞中p-STAT3、Cyclin D1、bcl-2蛋白表达水平，下调cleaved caspase 3蛋白水平。在敲低了Th22细胞中IL22表达或HepG2.2.15细胞中STAT3表达后，Th22细胞的上述作用被明显逆转。并且细胞实验发现Th22及Th17细胞与肝癌细胞共培养组，其STAT3蛋白及肝癌细胞增殖高于Th22及Th17细胞单独培养组。静脉注射 IL-22、IL-17、IL-22 和 IL-17 ，结果显示联合注射 IL-22 和 IL-17 的小鼠，肿瘤体积增长高于其他两组。以上结果说明，HBV通过诱使宿主Th22及Th17细胞产生大量细胞因子，协同激活肝癌细胞中STAT3及其下游信号蛋白，促进肝癌的进展。