Capsular polysaccharide of Streptococcus pneumoniae serotype 18C (CPS18C)

The capsular polysaccharide of Streptococcus pneumoniae serotype 18C is a complex carbohydrate structure that forms the outermost layer of the bacterium. It serves as a critical virulence factor by protecting the pathogen from host phagocytosis and complement-mediated killing, thereby facilitating invasive disease. The chemical structure of the 18C polysaccharide typically consists of a branched pentasaccharide repeating unit containing D-glucose, D-galactose, L-rhamnose, and N-acetyl-D-glucosamine, often substituted with glycerol phosphate. Due to its high immunogenicity when conjugated to carrier proteins, it is a primary component in several multivalent pneumococcal conjugate vaccines (PCVs) and polysaccharide vaccines. These vaccines aim to elicit protective IgG antibodies that recognize the 18C capsule, leading to the opsonization and clearance of the bacteria by the host immune system.

Other names

Pneumococcal polysaccharide serotype 18CS. pneumoniae serotype 18C capsular polysaccharideStreptococcus pneumoniae type 18C capsular polysaccharideCPS type 18C

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