Dysregulated BCR repertoire and metabolic state of HBsAg-specific B cells in chronic hepatitis B revealed by integrated single-cell analysis
Mengying He, Liangjun Shen, Yaming Li, Menghan Hao, Bing Wang, Yi Zhang, Min Wu, Zhanqing Zhang, Zhong Fang, Zhenghong Yuan, Jieliang ChenBackground:
Humoral immunity targeting hepatitis B virus (HBV) surface antigen (HBsAg) is critical for viral clearance. However, the phenotypic, repertoire, and metabolic features of HBsAg-specific B cells in chronic hepatitis B (CHB) remain incompletely defined.
Methods:
HBsAg-specific B cells were enriched using oligonucleotide-tagged antigen probes and profiled by integrated single-cell RNA sequencing (scRNA-seq) and single-cell B cell receptor sequencing (scBCR-seq) in HBeAg-positive CHB patients, convalescent individuals, and vaccinated healthy controls. Key findings were further evaluated in an independent cohort. Recombinant monoclonal antibodies (mAbs) were generated for functional validation, and
Results:
CHB patients exhibited expansion of unswitched memory (USW) and double-negative 1 (DN1) B cell subsets, characterized by impaired immunoglobulin class switching, altered co-stimulatory molecule expression, and increased clonal expansion. B cell receptor (BCR) repertoire analysis revealed biased immunoglobulin heavy chain variable (IGHV) gene usage and elevated somatic hypermutation in specific isotypes. Single-cell metabolic analysis demonstrated increased oxidative phosphorylation (OXPHOS) and reduced glutamine metabolism in CHB HBsAg-specific B cells. Recombinant mAbs showed heterogeneous and conformation-dependent antigen binding, with limited neutralizing activity. In
Conclusions:
HBsAg-specific B cells in CHB display coordinated alterations in subset composition, BCR repertoire, and metabolic state. These findings identify reproducible features of B-cell dysregulation and suggest a potential link between immunometabolic imbalance and impaired humoral responses, providing a framework for further mechanistic investigation.