乙型肝炎病毒抑制肝细胞免疫检查点PD-1配体基因表达的研究

摘要

目的 在细胞水平上分析乙型肝炎病毒(HBV)复制及其编码的X基因(HBx)表达对细胞基因表达谱的影响,特别是免疫相关基因表达水平的变化.方法 通过慢病毒和pcDNA瞬时转染过表达HBx基因,利用RNA-Seq和RT-qPCR等方法检测免疫相关基因的表达水平,并在HBV复制细胞系中进行验证.结果 HBV复制和HBx表达可以剂量依赖性抑制免疫检查点程序性死亡分子1(PD-1)配体基因(PD-L1/CD274)的表达,而HBx基因的H-box突变体的表达失去该抑制效应.结论 HBV/HBx具有抑制PD-L1/CD274基因表达的能力,在病毒感染的急性期解除抗原特异性T细胞激活的检查点,活化细胞毒性T细胞,这可能导致T细胞对高度复制的细胞进行攻击和清除,帮助病毒进入较低复制状态,达到病毒-宿主的平衡状态并奠定HBV慢性感染的基础.%Objective To analyze the impact of hepatitis B virus (HBV) replication and its coded X gene (HBx) expression on cell gene expression profile,especially the immune related gene expression level changes.Methods Overexpressed HBx gene was transiently transfected through lenti-virus and pcDNA3,the RNA-Seq and RT-qPCR methods were used to detect the expression levels of immune related genes,which were verified in HBV replication cell line.Results This study found that the HBV replication and HBx expression suppressed the expression of immune checkpoint PD-1 ligand gene (PD-L1/CD274) in a dose-dependent manner,while the expression of H-box mutant in HBx gene lost this inhibition effect.Conclusion HBV/HBx possesses the ability for inhibiting PD-L1/CD274 ligand gene expression,may relieve the checkpoint of antigen-specific T cell activation in viral infection acute stage,activates cytotoxic T cells,which may cause that T cell attack and clear highly replicated cells,helps virus to enter the lower replication status,and reaches the balance status between virus-host and lays a basis of HBV chronic infection.