慢性乙型肝炎（CHB）患者接受聚乙二醇干扰素-α（PEG-IFNα）治疗并实现功能性治愈后，HBV特异性B细胞的变化仍不清楚。我们的目的是评估治疗期间 HBV 特异性 B 细胞的变化，从而探讨 HBsAg 特异性 B 细胞功能恢复的机制。我们纳入了 39 名接受核苷（酸）类似物治疗的 CHB 患者，他们接受了序贯联合治疗PEG-IFNα 和 8 名初治慢性乙型肝炎患者。使用荧光标记的 HBsAg 和 HBcAg 体外表征 HBV 特异性 B 细胞。使用流式细胞术检测 HBV 特异性 B 细胞和滤泡辅助 T 细胞 (Tfh 细胞) 的频率、表型和亚群。通过 ELISpot 检测对 HBV 特异性 B 细胞的功能进行量化。治疗期间，HBsAg 特异性 B 细胞中活化记忆 B 细胞 (MBC) 的比例以及 IgG、CXCR3 和 CD38 的表达增加。只有在功能性治愈的患者治疗后，HBsAg特异性B细胞的抗体分泌能力才会恢复，并且与血清乙型肝炎表面抗体水平呈正相关。 HBsAg 特异性 B 细胞的表型和功能在功能性治愈和未功能性治愈的患者之间存在差异。功能性治愈的患者在 HBsAg 特异性 B 细胞中表现出 IgG 经典 MBC 和浆母细胞。治疗后，无论有无功能性治愈，HBcAg 特异性 B 细胞均表现出抗体分泌减弱、IgG 表达减少和 IgM 非典型类型的 MBC。 PEG-IFNα处理后CD40L Tfh细胞数量增加，并与HBsAg特异性B细胞活化呈正相关。PEG-IFNα处理后，HBsAg和HBcAg特异性B细胞在抗体分泌方面表现出各种变化。它们的功能差异反映在表型和亚型的改变上。 CD40L Tfh 细胞的存在与 HBsAg 特异性 B 细胞的主动恢复有关。HBV 相关并发症和肝细胞癌仍然是全世界慢性肝病死亡的主要原因，并且抗病毒治疗很少能治愈。阐明慢性乙型肝炎患者功能性治愈背后的免疫学机制为病毒清除提供了一种有前景的治疗策略，例如治疗性疫苗。我们分析了接受 PEG-IFNα 治疗的患者中 HBV 特异性 B 细胞的变化，并确定了免疫治疗增强 B 细胞免疫的新途径。版权所有 © 2024。由 Elsevier B.V 出版。

The changes of HBV-specific B-cells in chronic hepatitis B (CHB) patients underwent pegylated interferon-alfa (PEG-IFNα) treatment and achieved functional cure remain unclear. We aimed to evaluate the alterations in HBV-specific B-cells during treatment and therefore explored the mechanism of functional recovery of HBsAg-specific B-cells.We included 39 nucleos(t)ide analogues-treated CHB patients who received sequential combination therapy with PEG-IFNα and 8 treatment-naive CHB patients. HBV-specific B-cells were characterized ex vivo using fluorescent labeled HBsAg and HBcAg. The frequency, phenotype, and subsets of HBV-specific B-cells and follicular helper T cells (Tfh-cells) were detected using flow cytometry. The functionality of HBV-specific B-cells was quantified through ELISpot assays.During treatment, the fraction of activated memory B-cells (MBCs) among HBsAg-specific B-cells and the expression of IgG, CXCR3, and CD38 increased. Antibody-secretion capacity of HBsAg-specific B-cell was restored after treatment only in patients with a functional cure and it showed a positive correlation with serum hepatitis B surface antibody levels. The phenotype and function of HBsAg-specific B-cells differed between patients with and without functional cure. Patients with functional cure exhibited IgG+ classical MBCs and plasmablasts in HBsAg-specific B-cells. HBcAg-specific B-cells displayed both attenuated antibody secretion with reduced IgG expression and an IgM+ atypical type of MBCs after treatment, irrespective of with and without functional cure. The number of CD40L+ Tfh-cells increased after PEG-IFNα treatment and positively correlated with HBsAg-specific B-cell activation.After PEG-IFNα treatment, HBsAg- and HBcAg-specific B-cells exhibit various changes in antibody secretion. Their functional differences are reflected in the alterations in phenotypes and subtypes. The presence of CD40L+ Tfh-cells is associated with the active recovery of HBsAg-specific B-cells.HBV-related complications and hepatocellular carcinoma remain the leading causes of mortality from chronic liver disease worldwide, and a cure is rarely achieved with antiviral therapies. Elucidating the immunological mechanisms underlying the functional cure of CHB patients offers a promising therapeutic strategy for viral clearance, such as therapeutic vaccine. We analyzed the alterations in HBV-specific B-cells in patients treated with PEG-IFNα and identified novel pathways for immunotherapeutic boosting of B cell immunity.Copyright © 2024. Published by Elsevier B.V.