Porphyromonas gingivalis capsular polysaccharide (CPS (commonly used as abbreviation in literature for capsular polysaccharide, but rarely as a unique abbreviation for this species))

Porphyromonas gingivalis capsular polysaccharide (CPS) is a high-molecular-weight carbohydrate polymer forming a capsule surrounding the bacterium Porphyromonas gingivalis, a Gram-negative oral pathogen strongly associated with the onset and severity of chronic periodontitis and related inflammatory disorders[4][5][1]. The CPS is structurally diverse, composed of sugars such as mannuronic acid, glucuronic acid, galacturonic acid, galactose, and glucosamine or galactosamine, with strain-specific variations leading to the existence of at least seven immunochemically distinct serotypes[1][2][5]. As a major virulence factor, the capsule confers resistance to phagocytosis and environmental stress, enhances the organism’s persistence, modulates chemokine expression by host cells, and plays a key role in biofilm formation, collectively contributing to the microorganism’s survival and immune evasion[1][4][5][7]. Nonencapsulated strains are markedly less virulent in animal models, and the CPS has demonstrated immunogenic potential; immunization with purified CPS can elicit protective responses in mice[5][1]. No approved drugs directly target or interact with the capsular polysaccharide in clinical use, but the molecule is under study as a vaccine antigen and an immunologic marker of exposure and disease progression[5][1]. Expression of the capsular polysaccharide is genetically regulated by a large biosynthetic operon, and its synthesis and surface display are tightly linked to bacterial virulence[2][4][7]. The heterogeneity of capsule types in clinical isolates represents a notable challenge for therapeutics and diagnostics[5][1].

Other names

K-antigen capsulecapsuleCPScapsular antigen

Eliciting immune responses as an antigen; immune modulation via chemokine induction; mediating resistance to phagocytosis[1][5]