B-cell receptor recognizing hepatitis B virus surface antigen (HBsAg-specific BCR) (HBsAg-specific BCR)

The B-cell receptor recognizing hepatitis B virus surface antigen (HBsAg-specific BCR) is a membrane-bound immunoglobulin complex on the surface of B lymphocytes that specifically identifies the envelope protein of the hepatitis B virus (HBV). Upon binding to HBsAg, this receptor initiates intracellular signaling pathways, such as the recruitment of Syk kinase and activation of the NF-κB pathway, which drive B-cell proliferation and differentiation into plasma cells that secrete neutralizing anti-HBs antibodies (Salimzadeh et al., 2018, J Clin Invest). In a successful immune response, these antibodies prevent viral entry into hepatocytes and facilitate viral clearance. However, in chronic hepatitis B (CHB) infection, HBsAg-specific B cells often enter a state of exhaustion or functional impairment, characterized by high expression of inhibitory receptors like PD-1 and a failure to produce protective levels of antibodies (Burton et al., 2018, J Exp Med). This receptor is a primary target for therapeutic vaccines and novel immunotherapies designed to restore B-cell function and achieve a functional cure for HBV (Poonia et al., 2022, Front Immunol). Therapeutic strategies include the use of adjuvanted HBsAg vaccines to re-engage these receptors or the development of engineered B-cell therapies that express high-affinity HBsAg-specific BCRs.

Other names

HBsAg-specific B-cell receptorAnti-HBs BCRHepatitis B surface antigen-specific B-cell receptorHBV surface antigen-specific BCR

Binding of the hepatitis B surface antigen (HBsAg) to the specific B-cell receptor triggers a signal transduction cascade involving Lyn and Syk kinases, leading to B-cell activation, clonal expansion, and differentiation into plasma cells that secrete neutralizing anti-HBs antibodies.