Streptococcus pneumoniae serotype 8 capsular polysaccharide (PPS8)

Streptococcus pneumoniae serotype 8 capsular polysaccharide is a high-molecular-weight carbohydrate polymer that encapsulates the serotype 8 pneumococcal bacterium [1]. It is a linear polymer consisting of a repeating tetrasaccharide unit containing glucose, galactose, and rhamnose [2]. This capsule is a primary virulence factor that allows the bacterium to evade the host immune system by inhibiting opsonization and phagocytosis [3]. Serotype 8 is currently one of the most prevalent serotypes causing invasive pneumococcal disease (IPD) in adults worldwide [4]. The polysaccharide serves as a critical antigen in vaccine development to provide protection against pneumonia, meningitis, and sepsis [5]. It is a component of the 23-valent pneumococcal polysaccharide vaccine (PPSV23), the 20-valent pneumococcal conjugate vaccine (PCV20), and the 21-valent conjugate vaccine (PCV21) [6]. These vaccines work by stimulating the production of serotype-specific IgG antibodies that promote bacterial killing via the classical complement pathway [5]. Monitoring the immune response to this target is typically done through opsonophagocytic activity (OPA) assays or ELISA-based antibody quantification [6].

Other names

Pneumococcal polysaccharide serotype 8S. pneumoniae serotype 8 CPSType 8 pneumococcal polysaccharidePneumococcal polysaccharide type 8

Vaccine-mediated induction of serotype-specific IgG antibodies that facilitate opsonophagocytosis and complement-mediated lysis of the bacteria.