Salmonella typhimurium lipopolysaccharide (LPS)

Salmonella typhimurium lipopolysaccharide (LPS) is a complex glycolipid located in the outer leaflet of the bacterial outer membrane, serving as a critical structural component and a primary barrier against environmental stress and host immune factors (Raetz & Whitfield, 2002, Annu Rev Biochem). It is composed of three distinct regions: the hydrophobic Lipid A, which anchors the molecule and acts as the endotoxic moiety; a core oligosaccharide; and the O-antigen, a repeating polysaccharide chain that determines serological specificity (Whitfield & Trent, 2014, Biochim Biophys Acta). LPS is a potent pathogen-associated molecular pattern (PAMP) that is recognized by the host's Toll-like receptor 4 (TLR4)/MD-2 complex, initiating a robust pro-inflammatory signaling cascade (Park & Lee, 2013, Exp Mol Med). While essential for bacterial survival, its release during infection or bacterial lysis can lead to systemic inflammation, sepsis, and life-threatening septic shock (Gal-Mor et al., 2014, Front Immunol). Therapeutic targeting of LPS involves antibiotics like polymyxins, which bind to Lipid A to disrupt membrane integrity, as well as experimental approaches including LpxC inhibitors to block biosynthesis and monoclonal antibodies to neutralize the endotoxin (Poirel et al., 2017, Clin Microbiol Rev).

Other names

Salmonella enterica serovar Typhimurium lipopolysaccharideS. typhimurium LPSEndotoxinLipid AO-antigenBacterial lipoglycan

Drugs targeting this molecule typically work by binding to the Lipid A moiety to disrupt the bacterial outer membrane (e.g., polymyxins), inhibiting the biosynthetic enzymes such as LpxC to prevent LPS formation, or neutralizing the endotoxin to prevent TLR4-mediated inflammatory signaling.