B-cell receptor recognizing Streptococcus pneumoniae type 19F capsular polysaccharide (BCR-Sp19F)

The B-cell receptor (BCR) recognizing Streptococcus pneumoniae type 19F capsular polysaccharide is a specialized membrane-bound immunoglobulin complex found on the surface of specific B cell subsets. Its primary biological role is to detect and bind the unique repeating oligosaccharide units of the serotype 19F capsule, a critical virulence factor that allows the bacterium to evade the host immune system. Binding of the 19F antigen to the BCR triggers a cascade of intracellular signaling events, primarily through the Ig-alpha and Ig-beta subunits, leading to B cell activation and the subsequent production of protective antibodies. This receptor is the primary target for pneumococcal vaccines, such as conjugate (PCV13, PCV20) and polysaccharide (PPSV23) vaccines, which aim to stimulate the production of serotype-specific IgG and IgM. These antibodies facilitate the opsonization and clearance of the bacteria by phagocytes, thereby preventing invasive diseases like pneumonia, meningitis, and sepsis. Understanding the interaction between this BCR and its cognate epitopes is essential for the design of more effective vaccines and for monitoring population-level immunity against Streptococcus pneumoniae.

Other names

Anti-pneumococcal 19F B-cell receptorS. pneumoniae serotype 19F-specific B-cell receptorBCR for pneumococcal polysaccharide 19F

Antigen-mediated cross-linking of the B-cell receptor triggers intracellular signaling, leading to B-cell activation, proliferation, and differentiation into plasma cells that secrete serotype-specific antibodies.