Lipopolysaccharide of Shigella flexneri serotype 2a (LPS of S. flexneri 2a)

Lipopolysaccharide (LPS) of Shigella flexneri serotype 2a is a surface glycolipid consisting of lipid A, a core oligosaccharide, and a serotype-specific O-polysaccharide (O-antigen) composed of a tetrasaccharide backbone (three L-rhamnose and one N-acetylglucosamine) modified by glucosylation and O-acetylation. It serves as the principal antigenic determinant distinguishing S. flexneri 2a from other serotypes, drives the host immune response, and supports virulence by mediating acid resistance, resisting complement killing, and promoting cell adhesion and invasion. LPS is the main target of protective antibodies and vaccine candidates, and serotype-specific immunity to Shigella is largely driven by recognition of this molecule. This molecule is not a receptor, enzyme, or typical human therapeutic target, but is classified as a bacterial structural antigen that is an essential target for immunotherapy and vaccine design.

Other names

S. flexneri 2a LPSShigella flexneri serotype 2a O-antigenShigella flexneri O-specific polysaccharide (O-SP)

Antibodies bind and neutralize bacterial LPS, blocking colonization and invasion Vaccines induce LPS-specific protective immunity