NCIt definition : An endotoxin and biologically active component of the Gram-negative bacterial cell
wall that is a Toll-like receptor 4 (TLR4) agonist with potential immunostimulatory
activity. Upon internalization, lipopolysaccharide (LPS) activates TLR4 which in turn
activates the NFkappaB pathway, in addition to mitogen-activated protein kinases signaling
pathways. This leads to the release of proinflammatory cytokines and stimulates an
innate immune response against vaccine antigens.;