Streptococcus pneumoniae cell wall phosphocholine and capsular polysaccharide (PC/CPS)

Streptococcus pneumoniae cell wall phosphocholine (PC) and related surface carbohydrates, primarily the capsular polysaccharide (CPS), are essential determinants of pneumococcal virulence and host-pathogen interactions. Phosphocholine is a key component of teichoic and lipoteichoic acids, acting as a docking site for choline-binding proteins (CBPs) and facilitating bacterial adherence to host cells by binding to the platelet-activating factor (PAF) receptor [1][2]. The capsular polysaccharide forms the outermost layer of the bacterium, providing protection against opsonophagocytosis and environmental stress, with over 100 distinct serotypes identified to date [3]. These surface structures are the primary targets for pneumococcal vaccines, including conjugate and polysaccharide formulations, which elicit protective antibodies to enhance bacterial clearance [4]. Additionally, phosphocholine is a target for the innate immune system via C-reactive protein (CRP) and has been investigated as a target for broad-spectrum monoclonal antibody therapies due to its conserved nature across different pneumococcal strains [5].

Other names

Pneumococcal surface carbohydratesC-polysaccharideTeichoic acid phosphocholineLipoteichoic acid phosphocholinePneumococcal capsular polysaccharideC-substance

Induction of opsonophagocytic antibodies that bind to surface carbohydrates, facilitating bacterial clearance by the immune system; inhibition of bacterial adherence to host tissues by blocking phosphocholine-mediated binding to host receptors.