Pneumococcal capsular polysaccharide serotype 6B (CPS6B)

Pneumococcal capsular polysaccharide serotype 6B is a high-molecular-weight polymer that forms the outermost protective layer of Streptococcus pneumoniae serotype 6B. This polysaccharide is a primary virulence factor that enables the bacterium to evade the host immune system by inhibiting opsonophagocytosis (PubMed, PMID: 11854811). Structurally, it is composed of repeating tetrasaccharide units linked by phosphodiester bonds, containing rhamnose, ribitol, galactose, and glucose (PubChem, CID: 71306852). Because serotype 6B is frequently associated with invasive diseases such as pneumonia, meningitis, and febrile bacteremia, it is a standard component in pneumococcal vaccines. These vaccines, such as PCV13 and PCV20, utilize the purified polysaccharide to induce a protective humoral immune response characterized by the production of serotype-specific IgG antibodies (CDC, 2022, https://www.cdc.gov/vaccines/pubs/pinkbook/pneumo.html). These antibodies facilitate the clearance of the bacteria by promoting their recognition and ingestion by phagocytic cells. The 6B serotype is particularly noted for its historical prevalence in pediatric populations and its inclusion in the earliest conjugate vaccine formulations. Therapeutic targeting of this polysaccharide remains a cornerstone of global efforts to reduce the burden of pneumococcal disease.

Other names

Streptococcus pneumoniae serotype 6B capsular polysaccharidePn6B polysaccharide6B CPSPneumococcal polysaccharide 6BPneumococcal capsular antigen 6B

Induction of active immunity through the production of serotype-specific opsonizing antibodies that facilitate phagocytosis and killing of Streptococcus pneumoniae.