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

The Hepatitis B surface antigen-specific B cell receptor (HBsAg-specific BCR) is a specialized transmembrane protein complex located on the surface of B lymphocytes (Burton et al., 2018, J. Clin. Invest.). Its primary biological function is the specific recognition and binding of the Hepatitis B surface antigen (HBsAg), the major envelope protein of the Hepatitis B virus (HBV) (Zhang et al., 2023, Front. Immunol.). Upon antigen binding, the BCR initiates a cascade of intracellular signaling that drives B cell activation, clonal expansion, and differentiation into antibody-secreting plasma cells (Salimzadeh et al., 2018, Gut). These plasma cells produce neutralizing anti-HBs antibodies, which are critical for clearing the virus and providing long-term immunity. In chronic Hepatitis B (CHB) infection, HBsAg-specific B cells often become dysfunctional or exhausted due to prolonged exposure to high levels of circulating HBsAg, characterized by high expression of inhibitory receptors like PD-1 (Burton et al., 2018, J. Clin. Invest.). Therapeutic interventions targeting this machinery include therapeutic vaccines like VBI-2601 (BRII-179) and monoclonal antibodies like VIR-3434, which aim to restore B cell activity or provide passive immunity (Zhang et al., 2023, Front. Immunol.). Restoring the functionality of these B cells is considered a cornerstone for achieving a functional cure in patients with chronic HBV.

Other names

HBsAg-specific B-cell receptorAnti-HBs B-cell receptorHepatitis B surface antigen recognition complexB-cell receptor for HBsAg

Activation of B cell signaling pathways to induce the production of neutralizing anti-HBs antibodies and establish immunological memory.