Streptococcus pneumoniae type 9V capsular polysaccharide (CPS 9V)

The Streptococcus pneumoniae type 9V capsular polysaccharide (CPS) is a high molecular weight polymer forming the bacterium's outer layer. This capsule is a major virulence factor that protects the organism from host immune responses. It's a key component of vaccines used to prevent pneumococcal diseases. The repeating unit is a pentasaccharide, and the polymer is partially O-acetylated, affecting immunogenicity. Biosynthesis is Wzx/Wzy-dependent. Type-specific antibodies recognize structural features including O-acetate modifications, and immunization induces protective immunity against S. pneumoniae type 9V.

Other names

Streptococcus pneumoniae Type 9V Capsular Polysaccharide AntigenPneumococcal Capsular Polysaccharide Type 9V VaccinePneumococcal Polysaccharide Powder Type 9V

Antibodies bind to the polysaccharide capsule, promoting opsonophagocytosis and complement-mediated killing of the bacteria. Vaccines elicit the production of such antibodies.