Neisseria meningitidis serogroup W-135 capsular oligosaccharide

The **Neisseria meningitidis serogroup W-135 capsular oligosaccharide** is a linear, high-molecular-weight polysaccharide consisting of partly O-acetylated repeating disaccharide units of **sialic acid (N-acetylneuraminic acid)** and **D-galactose,** linked via α-(2→6) and α-(1→4) glycosidic bonds. This polysaccharide forms the outer capsule of serogroup W-135 strains and serves as a major virulence factor by protecting the bacteria from host immune clearance, particularly complement-mediated killing and opsonization. The capsule is the target of protective antibodies and forms the basis of conjugate vaccines against meningococcal disease caused by this serogroup. Its structure is closely related to, but distinct from, the serogroup Y capsule, differing in the use of D-galactose (W-135) versus D-glucose (Y) as the partner sugar in the disaccharide repeat, and its biosynthetic genes are closely linked but distinct among serogroups. Capsule switching, whereby the genetic locus encoding the capsule can be replaced by those from other serogroups, allows immune escape and complicates disease surveillance and vaccine strategy.

Other names

Neisseria meningitidis serogroup W-135 capsuleNeisseria meningitidis group W-135 capsular polysaccharideN. meningitidis W-135 oligosaccharidegroup W-135 polysaccharideGWMP (group W-135 meningococcal polysaccharide)

Induction of protective antibody response against W-135 polysaccharide capsule (via vaccination with conjugated oligosaccharide); Antibody-mediated bacterial clearance through opsonization