Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
LPS (Lipopolysaccharide) is a major component of the outer membrane of Gram-negative bacteria, acting as an endotoxin. It plays a crucial role in triggering strong immune responses and can lead to conditions like septic shock.
5 Must Know Facts For Your Next Test
LPS consists of three parts: lipid A, core polysaccharide, and O antigen.
The lipid A component is responsible for the toxic effects associated with LPS.
LPS can activate the innate immune system by binding to Toll-like receptor 4 (TLR4).
High levels of LPS in the bloodstream can cause severe inflammatory responses and septic shock.
LPS is a key virulence factor for many Gram-negative pathogens such as Escherichia coli and Salmonella.