EDITORIAL Lipopolysaccharide and the lung: a story of love and hate

ipopolysaccharide (LPS) is a major component of the outer membrane of Gram-negative bacteria. LPS is one of the most potent microbial inducers of inflammation and is responsible for many of the deleterious effects of pulmonary infections. In contrast, surfaces of the body are constantly exposed to small amounts of LPS. This interaction appears to stimulate more beneficial, protective mechanisms. Overall, the interactions between LPS and the body are important; however, factors that determine the nature of this response are not known. LPS is a prototypical pathogen associated molecular pattern (PAMP), a term that was introduced by JANEWAY and MEDZHITOV [1], which describes structurally conserved mol-ecules of microorganisms. PAMPs bind to receptors of the innate immune system, consequently called pattern recogni