Shigella dysenteriae O1 polysaccharide

The **Shigella dysenteriae O1 polysaccharide** is the O-specific polysaccharide (O-antigen) component of the lipopolysaccharide (LPS) found on the surface of *Shigella dysenteriae* type 1 bacteria. It consists of repeating oligosaccharide units specific to this serotype and serves as both a critical virulence factor and a major protective antigen that determines the immunological specificity of the bacterium[4]. This polysaccharide is a key target for vaccine development, as antibodies generated against it can confer protection against infection by neutralizing or aiding in the clearance of the bacteria[2][3]. Due to its poor immunogenicity as a free molecule, it must be covalently conjugated to a carrier protein in order to induce a strong and protective IgG antibody response in humans. Conjugate vaccines using this polysaccharide have been developed and shown both immunogenicity and safety in human clinical trials[2][3]. There are no known small-molecule drugs that act directly on this target, with its primary therapeutic application being in vaccine development for prevention of shigellosis, a severe infectious diarrheal disease.

Other names

Shigella dysenteriae type 1 O-specific polysaccharideS. dysenteriae type 1 O-antigenShigella dysenteriae type 1 O-SP

Vaccine conjugates stimulate production of protective anti-polysaccharide IgG antibodies[2][3] Induction of immune memory by presentation as a conjugate with protein carriers[2][3]