Human B cell receptor specific for pneumococcal capsular polysaccharide epitopes (BCR-PnPS)

The human B cell receptor (BCR) specific for pneumococcal capsular polysaccharide (PnPS) epitopes is a specialized transmembrane protein complex that mediates the recognition of Streptococcus pneumoniae (Nature Reviews Immunology). This receptor consists of a membrane-bound immunoglobulin (mIg) that binds to specific carbohydrate antigens on the bacterial capsule, coupled with the CD79a and CD79b signaling subunits (PubMed, PMID: 30135203). Activation of these BCRs is the fundamental mechanism by which the immune system generates protective antibodies, which are essential for the opsonization and clearance of the bacteria (Clinical Microbiology Reviews). These receptors are the primary targets for pneumococcal vaccines, including both pure polysaccharide (PPSV23) and protein-polysaccharide conjugate (PCV13, PCV20) formulations (CDC). While plain polysaccharides act as T-cell independent antigens, conjugate vaccines allow the BCR to internalize the antigen-protein complex, facilitating T-cell help and the development of long-lived memory B cells (Vaccine). Understanding the diversity and specificity of these BCRs is critical for monitoring vaccine efficacy and addressing the challenges of serotype replacement (Journal of Infectious Diseases).

Other names

Anti-pneumococcal B cell receptorPneumococcal polysaccharide-specific B cell receptorPnPS-specific BCRAnti-PnPS BCR

Antigen-induced cross-linking of the B cell receptor (BCR) triggers intracellular signaling cascades through the CD79a/CD79b heterodimer, leading to B cell proliferation, differentiation into antibody-secreting plasma cells, and the generation of immunological memory.