B-cell antigen receptor (BCR) specific for SARS-CoV-2 receptor-binding domain (RBD) epitopes (SARS-CoV-2 RBD-specific BCR)

The B-cell antigen receptor (BCR) specific for the SARS-CoV-2 receptor-binding domain (RBD) is a membrane-bound immunoglobulin complex that plays a pivotal role in the adaptive immune response to COVID-19. Located on the surface of B lymphocytes, these receptors specifically recognize and bind to epitopes within the RBD of the viral spike protein, which is the primary mediator of viral entry into host cells via the ACE2 receptor (Robbiani et al., Nature 2020). Upon antigen binding, the BCR initiates a signaling cascade that leads to B-cell activation, germinal center formation, and the production of high-affinity neutralizing antibodies (Turner et al., Nature 2021). This target is the primary focus of most COVID-19 vaccines, which aim to elicit a robust population of RBD-specific memory B cells to provide long-lasting protection (Sakharkar et al., Nature Communications 2021). The diversity and affinity of these receptors determine the breadth of the immune response against various SARS-CoV-2 variants (Gaebler et al., Nature 2021). Monitoring the frequency and evolution of RBD-specific BCRs serves as a critical biomarker for assessing the durability of vaccine-induced immunity. Understanding the structural basis of BCR-RBD interactions is also vital for the development of next-generation vaccines and therapeutic monoclonal antibodies. These receptors are essential for the generation of immunological memory, allowing the host to respond more rapidly and effectively upon re-exposure to the virus.

Other names

SARS-CoV-2 RBD-specific B-cell receptorAnti-SARS-CoV-2 RBD BCRSpike RBD-specific BCRAnti-RBD B-cell antigen receptor

Vaccine-delivered antigens (e.g., mRNA-encoded spike protein or recombinant RBD) bind to the BCR on naive or memory B cells, inducing receptor clustering and intracellular signaling through the Ig-alpha/Ig-beta (CD79a/CD79b) complex, which leads to B-cell proliferation and differentiation (Turner et al., Nature 2021).