Capsular polysaccharide of Streptococcus pneumoniae serotype 7F (CPS 7F)

The capsular polysaccharide of Streptococcus pneumoniae serotype 7F is a complex carbohydrate polymer that forms the outermost protective layer of the bacterium. It serves as a primary virulence factor by shielding the pathogen from the host's immune system, specifically by preventing opsonization and subsequent phagocytosis by immune cells like neutrophils. Serotype 7F is recognized as a highly invasive strain, frequently associated with severe invasive pneumococcal diseases (IPD) such as meningitis, bacteremia, and pneumonia, particularly in children and the elderly. Due to its clinical significance, this polysaccharide is a key antigenic target in several multivalent pneumococcal vaccines, including conjugate vaccines like PCV13, PCV15, and PCV20, as well as the polysaccharide vaccine PPSV23. These vaccines work by inducing the production of serotype-specific antibodies that bind to the 7F polysaccharide, thereby facilitating the clearance of the bacteria through opsonophagocytosis.

Other names

Serotype 7F capsular polysaccharidePnPs 7FPneumococcal polysaccharide 7FStreptococcus pneumoniae type 7F polysaccharidePn7F

Induction of a serotype-specific humoral immune response where vaccine-derived antibodies (IgG) bind to the capsular polysaccharide, promoting opsonization and subsequent clearance by phagocytic cells.