Pseudomonas aeruginosa lipopolysaccharide O11 (P. aeruginosa LPS O11)

Pseudomonas aeruginosa lipopolysaccharide (LPS) O11 is a complex glycolipid located in the outer membrane of the Gram-negative bacterium Pseudomonas aeruginosa, specifically defining the O11 serotype. It consists of a conserved lipid A moiety, a core oligosaccharide, and a highly variable O-specific polysaccharide (O-antigen) that extends into the extracellular environment (Pier, 2007, PubMed: 17510665). This molecule serves as a critical virulence factor by providing structural integrity to the cell wall and acting as a barrier against host immune components, including complement proteins and cationic antimicrobial peptides (King et al., 2009, PubMed: 19129407). The O11 serotype is one of the most prevalent strains isolated from patients with hospital-acquired infections, such as ventilator-associated pneumonia and bacteremia. Consequently, the O11-specific O-antigen is a primary target for passive immunotherapy and vaccine development. For example, Panobacumab (AR-101) is a human monoclonal IgM antibody designed to bind specifically to the O11 O-polysaccharide, thereby enhancing opsonophagocytic killing of the bacteria by host neutrophils (Horn et al., 2010, PubMed: 21135141). While highly effective against its specific serotype, the therapeutic use of such agents is limited by the high degree of antigenic variation among different P. aeruginosa strains.

Other names

O11 antigenO11 O-polysaccharidePseudomonas aeruginosa serotype O11 lipopolysaccharideP. aeruginosa O11 LPSO11-specific O-antigen

Binding to the O-polysaccharide moiety of the lipopolysaccharide to facilitate opsonophagocytosis by host immune cells and neutralize endotoxic activity.