HBx/DCreg-Treg轴上调IL-35表达致HBV感染慢性化的分子机制及干预策略研究

免疫调控在HBV感染慢性化中起重要作用。已知，HBx蛋白是病毒致病重要激活因子，HBV特异性细胞毒T细胞（CTL）耗竭是感染慢性化关键因素。我们前期发现IL-35在慢性乙肝患者中高表达且抑制CTL功能，是调控乙肝慢性化的关键分子，但其表达上调机制不明。本项目拟在此基础上，首先利用细胞模型确定HBx经DCreg-Treg轴激活ERK/JNK/NF-κB通路及其与IL-35表达上调的关系；进而探明上述信号转录因子与IL-35结合，调控其表达的确切证据；然后了解miR-122结合并降解IL-35各亚基mRNA抑制其表达的作用与机制；最后采用HBV转基因小鼠模型，进一步验证HBx经DCreg-Treg轴诱导IL-35表达和miR-122抑制HBx、IL-35表达及其与HBV特异性CTL耗竭关系，以期深入了解HBV感染慢性化的分子调控机制，为开拓新型疗法提供潜在靶标，为慢性乙肝的精准治疗提供新策略。

Immunoregulation plays pivotal roles in the processes of chronic hepatitis B virus (HBV) infection. Previous studies have demonstrated that HBV x protein (HBx) is considered to be an important transcriptional activator of HBV pathogenesis, and HBV-specific cytotoxic T lymphocyte (CTL) exhaustion has been confirmed as a key causative agent in chronic HBV infection. Our former studies have shown that IL-35 is highly expressed in chronic hepatitis B patients and inhibits CTL function. It suggests that IL-35 is a critical molecule for regulating the chronicity of HBV infection. However, the mechanism of its up-regulated expression is unknown. Based on the above findings, in this project, we will establish cell model to confirm that HBx can activate the ERK/JNK and NF-κB signaling pathways in regulatory T cell (Treg) via regulatory dendritic cells (DCreg)-Treg axis and find the relationship between this pathway and IL-35 expression up-regulation, to further clarify the above evidence that the signal transcription factor binds to IL-35 and regulates its expression. Then we will reveal the role and mechanism of miR-122 binding and degradation of IL-35 subunit mRNA to inhibit its expression. Finally, the mouse model was transfected with HBV genome to further verify the expression of IL-35 induced by DCreg-Treg axis, the inhibition of HBx and IL-35 expression by miR-122, and its relationship with HBV-specific CTL exhaustion. Our aim is to gain an in-depth understanding of the regulation mechanism of chronic HBV infection in molecular resolution and to provide potential targets for the development of new therapies, which brings new strategies for the precise treatment of chronic hepatitis B.