背景:慢性HCV感染导致与适应性免疫细胞的复杂相互作用,可能导致B细胞异常,如冷球蛋白血症或淋巴瘤。虽然直接作用的抗病毒治疗降低了严重肝损伤的发生率,其对肝外HCV表现如B细胞异常的影响尚不清楚。
方法:我们对慢性HCV单感染患者和直接抗病毒治疗后持续病毒学应答(SVR)的HCV患者的B细胞受体(BCR)谱进行了测序。挖掘该数据集用于高度中和HCV抗体,并与弥漫性大B细胞淋巴瘤数据集进行比较。使用TKO模型在体外测试所选择的B-BCR的信号传导强度。进行慢性HCV和HCVSVR样品的单细胞RNA测序以分析具有HCV中和抗原受体的B细胞的转录组。
结果:我们在慢性HCV和SVR患者中鉴定了一个具有高丰富度和体细胞超突变的B细胞指纹。与特定免疫球蛋白基因的融合产生了高连接性的互补决定区3网络。此外,我们观察到,作为高中和HCV抗体特征的IGHV1-69CDR1和FR3突变与高级别淋巴瘤克隆型BCR中发现的复发点突变相对应.这些BCR在体外细胞模型中不显示自主信号传导,而是显示较低的活化阈值,用于评估BCR信号传导强度。单细胞RNA测序显示,携带这些点突变的B细胞显示出持续的致癌转录组特征,在信号节点如CARD11,MALT1,RelB,MAPK,NFAT。
结论:我们提供了淋巴瘤样细胞来源于抗HCV免疫应答的证据。在许多患者中,这些细胞在SVR后持续数年,可以解释为HCV相关B细胞恶变和淋巴瘤风险增加的机制基础,甚至超过病毒消除.
BACKGROUND: Chronic HCV infection leads to a complex interplay with adaptive immune cells that may result in B cell dyscrasias like cryoglobulinemia or lymphoma. While direct-acting antiviral therapy has decreased the incidence of severe liver damage, its effect on extrahepatic HCV manifestations such as B cell dyscrasias is still unclear.
METHODS: We sequenced B cell receptor (BCR) repertoires in patients with chronic HCV mono-infection and patients with HCV with a sustained virological response (SVR) after direct-acting antiviral therapy. This data set was mined for highly neutralizing HCV antibodies and compared to a diffuse large B cell lymphoma data set. The TKO model was used to test the signaling strength of selected B-BCRs in vitro. Single-cell RNA sequencing of chronic HCV and HCV SVR samples was performed to analyze the transcriptome of B cells with HCV-neutralizing antigen receptors.
RESULTS: We identified a B cell fingerprint with high richness and somatic hypermutation in patients with chronic HCV and SVR. Convergence to specific immunoglobulin genes produced high-connectivity complementarity-determining region 3 networks. In addition, we observed that IGHV1-69 CDR1 and FR3 mutations characterizing highly neutralizing HCV antibodies corresponded to recurrent point mutations found in clonotypic BCRs of high-grade lymphomas. These BCRs did not show autonomous signaling but a lower activation threshold in an in vitro cell model for the assessment of BCR signaling strength. Single-cell RNA sequencing revealed that B cells carrying these point mutations showed a persisting oncogenic transcriptome signature with dysregulation in signaling nodes such as CARD11, MALT1, RelB, MAPK, and NFAT.
CONCLUSIONS: We provide evidence that lymphoma-like cells derive from the anti-HCV immune response. In many patients, these cells persist for years after SVR and can be interpreted as a mechanistic basis for HCV-related B cell dyscrasias and increased lymphoma risk even beyond viral elimination.