Staphylococcus aureus capsular polysaccharide serotype 5 (CP5) (CP5)

Staphylococcus aureus capsular polysaccharide serotype 5 (CP5) is a major surface-expressed carbohydrate antigen that plays a critical role in the pathogenesis of S. aureus infections. It is composed of a repeating trisaccharide unit containing N-acetyl-D-mannosaminuronic acid, N-acetyl-L-fucose, and N-acetyl-D-fucose (PMID: 2624429). CP5 functions primarily as a virulence factor by inhibiting opsonophagocytosis by host polymorphonuclear leukocytes, thereby allowing the bacteria to evade the innate immune system (PMID: 11514592). Because approximately 75-85% of clinical S. aureus isolates express either CP5 or CP8, these polysaccharides have been primary targets for vaccine development (PMID: 15557066). Therapeutic strategies have included conjugate vaccines, such as StaphVAX, which aimed to induce protective opsonophagocytic antibodies, although clinical trials have faced challenges in achieving sustained efficacy (PMID: 16333005). Additionally, CP5 is a target for passive immunotherapy using monoclonal antibodies or hyperimmune globulin to enhance bacterial clearance during bacteremia and other invasive infections (PMID: 12531339).

Other names

Type 5 capsular polysaccharideS. aureus CP5Serotype 5 capsular polysaccharideStaphylococcus aureus CP5

Induction of opsonophagocytic antibodies to facilitate bacterial clearance by neutrophils