Meningococcal group Y capsular polysaccharide (MenY CPS)

The meningococcal group Y capsular polysaccharide is a high-molecular-mass, surface-exposed glycoconjugate composed of alternating D-glucose and partially O-acetylated sialic acid residues, unique to *N. meningitidis* serogroup Y[1]. It is synthesized by specific capsule biosynthesis genes within the *cps* locus, which regulate not only the polymer’s composition but also its level of surface expression on the bacterium[1][3]. This capsule is a major *virulence factor*, allowing the organism to evade host immune mechanisms, such as complement-mediated lysis and opsonophagocytosis[2]. Critically, the group Y polysaccharide is both the target of immune responses elicited by meningococcal polysaccharide and conjugate vaccines and a biomarker for monitoring protection against serogroup Y disease[4]. The structure–function relationship of this capsule also informs rational vaccine design and understanding of pathogenesis[1][2][3].

Other names

Group Y capsuleNeisseria meningitidis serogroup Y capsular polysaccharideMenY capsule

Vaccines stimulate the production of anti-capsular polysaccharide antibodies, promoting complement-mediated lysis, phagocytosis, and clearance of the bacteria