Hepatitis B surface antigen-specific B cell receptor (HBsAg-specific BCR)

The Hepatitis B surface antigen-specific B cell receptor (HBsAg-specific BCR) is a membrane-bound immunoglobulin complex located on the surface of B lymphocytes that specifically recognizes the Hepatitis B surface antigen (HBsAg). Its primary biological function is to mediate the humoral immune response by binding to HBsAg, which triggers B cell activation, clonal expansion, and differentiation into plasma cells that secrete neutralizing anti-HBs antibodies (Salimzadeh et al., 2018, J Clin Invest). In acute Hepatitis B virus (HBV) infection, these receptors are essential for viral clearance and the establishment of protective immunity. However, in chronic Hepatitis B (CHB), HBsAg-specific B cells often become functionally impaired or exhausted, failing to produce sufficient neutralizing antibodies to control the infection (Le Bert et al., 2020, Gastroenterology). This receptor is the primary target for prophylactic vaccines, such as Engerix-B and Heplisav-B, which aim to induce a robust memory B cell population (CDC, 2023). Furthermore, novel therapeutic vaccines like VBI-2601 are currently being investigated for their ability to re-activate these dysfunctional B cells in chronic patients as part of a functional cure strategy (ClinicalTrials.gov, 2024). Monitoring the frequency and activation state of HBsAg-specific BCRs serves as a critical biomarker for evaluating the efficacy of HBV immunotherapies.

Other names

HBsAg-specific BCRAnti-HBs B-cell receptorHepatitis B surface antigen-binding receptorHBsAg-binding B-cell receptor

Agonism of the B cell receptor to stimulate B cell activation, proliferation, and differentiation into anti-HBs antibody-secreting plasma cells (Salimzadeh et al., 2018; Le Bert et al., 2020).