Tfh细胞-IL21-B细胞轴在慢性乙型肝炎HBeAg血清学转换中的作用及补肾方的干预机制

HBeAg seroconversion is the marker of immune control in chronic hepatitis B patients. In previous RCT researches, we found that the HBeAg seroconversion rate was increased after patients were administrated with Bushen Recipe, and the percentages of CXCR5+CD4+Tfh cells and B cells in peripheral blood in patients who achieved HBeAg seroconversion were higher than those in patients who did not achieve HBeAg seroconversion, which suggested that Tfh cell played the key role in HBeAg seroconversion. Bcl-6 and Blimp-1 are a couple of transcription factors of controling the differentiation of Tfh cells, and they are antagonistic to each other.The high expression of Bcl-6 promotes the differentiation of Tfh cells, and IL21 expressed by Tfh cells promotes to the production of HBeAb by B cells. Therefore, the research hepothesis is proposed that when HBeAg positive patients were administrated with Bushen Recipe, the expression of Bcl-6 in CD4+ cells of peripheral blood is upregulated and the expression of Blimp-1 is reduced, which promotes CD4+T cells to defferentiate into Tfh cells, and then IL21 expressed by Tfh cells activates B cells ,and finally HBeAb is secreted. In this study, the relationship between HBeAg seroconversion induced by BSR treatment an the balance of Bcl-6/Blimp-1 and the axis of Tfh cell-IL21-B cell will be explored through the clinial RCT research and in vitro experiments, and the mechanism of HBeAg seroconversion induced by BSR and its herbs treatment will be further confirmed in mouse model of chronic HBV infection,which will illuminate the key targets of immunoregulatory mechanism of Bushen Recipe in chronic hepatitis B patients.

乙肝e抗原（eAg）血清转换是慢乙肝（CHB）免疫控制标志。前期RCT研究证实,补肾方（BSR）提高CHB患者eAg阴转率,且eAg血清转换者外周血CXCR5+CD4+Tfh细胞和B细胞频数高于未转换者,提示Tfh是eAg血清转换关键。BCL-6/Blimp-1是Tfh分化的一对相互拮抗的转录因子,高表达BCL-6促进Tfh分化,Tfh表达IL21促进B细胞分泌HBeAb。据此提出假说,BSR通过上调eAg+患者外周血CD4+T细胞BCL-6、下调Blimp-1,促进自身分化为Tfh并表达IL21,活化B细胞分泌HBeAb,提高血清转换率。拟通过临床RCT研究和体外实验探索BSR促进eAg血清转换与BCL-6/Blimp-1平衡和Tfh-IL21-B细胞轴分子表达的内在关系,应用HBV持续感染小鼠模型进一步证实BSR及拆方促进eAg血清转换机制,阐明BSR调节免疫治疗CHB关键靶点。

补肾方是治疗慢乙肝的有效验方。乙肝 e 抗原(eAg)血清转换是慢乙肝(CHB)免疫控制标志。前期 RCT 研究证 实,补肾方(BSF)提高 CHB 患者 eAg 阴转率,且 eAg 血清转换者外周血 CXCR5+CD4+Tfh 细胞 和 B 细胞频数高于未转换者,提示 Tfh 是 eAg 血清转换关键。BCL-6/Blimp-1 是 Tfh 分化的一 对相互拮抗的转录因子,高表达 BCL-6 促进 Tfh 分化,Tfh 表达 IL21 促进 B 细胞分泌 HBeAb。本研究主要通过临床RCT研究和体外实验探索 BSR 促进 eAg 血清转换与 BCL-6/Blimp-1 平衡和 Tfh-IL21-B 细胞轴分子表达的内在关系,应用 HBV 持续感染小鼠模型进一步证实 BSF及其组成药物促进 eAg 血清转换机制,阐明 BSF 调节免疫治疗 CHB 关键靶点。临床研究结果表明，补肾方治疗后，患者的中医证候积分明显降低， HBVDNA的阴转率、HBeAg的阴转率和HBeAg的血清学转换率均明显高于抗病毒药物组，但治疗后两组患者HBsAg的阴转率差异无显著性。机制研究发现，补肾方可明显上调慢乙肝患者外周血Tfh细胞表达的IL-21， 但对PD-1和Blimp-1无显著调节作用；补肾方可明显上调B细胞亚群IgD+CD38+CD19+细胞和IgD+CD27+细胞频数，降低IgD+CD38-CD19+细胞频数，抗病毒药物治疗可降低IgD+CD38- CD19+细胞频数。体外研究和转基因动物模型研究证实，补肾方抗HBV的有效药物为仙灵脾，其通过上调CXCR5+CD4+细胞的频数降低CXCR5+CD19+细胞的频数，促进IL-21的表达，以降低HBeAg的表达水平，发挥抗病毒作用。该研究结果明确了中药补肾方治疗CHB的免疫调节的有效药物和关键靶点，丰富了中药治疗CHB的现代医学内涵，为开发现代中药提供了新的研究方向。