Animals defend themselves from many Gram-negative bacteria by 1) sensing the lipopolysaccharide found in the bacterial cell wall and then 2) mounting inflammatory reactions that kill the bacteria. Our research has produced strong evidence for a new concept: In order to recover from infection, animals must kill these bacteria and inactivate their LPS. We made mice that are unable to inactivate LPS and found that they never completely recover from exposure to LPS or to bacteria that make LPS. Their macrophages and other cells remain "reprogrammed" in ways that make them respond very slowly when they are re-exposed to LPS or other microbial molecules. As a result, they are much more likely to die when they are challenged with virulent Gram-negative bacteria.
Robert S. Munford, M.D.Senior Clinician and Deputy Chief, Laboratory of Clinical Infectious DiseasesChief, Antibacterial Host Defense Section
Mingfang Lu, Ph.D.
Last Updated July 20, 2010
Last Reviewed July 20, 2010