Lipopolysaccharide structure influences the macrophage response via CD14-independent and CD14-dependent pathways

Clin Infect Dis. 1999 Mar;28(3):491-6. doi: 10.1086/515176.


CD14, a protein expressed on the surface of monocytes and neutrophils, is a major receptor for lipopolysaccharide (LPS). Studies with normal and CD14-deficient macrophages show that responses to low concentrations of LPS require expression of CD14, whereas responses to high concentrations of LPS are CD14-independent. Since LPS isolated from different bacterial species shows structural variability, studies were performed to determine whether differences in LPS structure influence CD14-dependent and CD14-independent responses. Studies with LPS purified from Escherichia coli, Salmonella abortus subspecies equi, Salmonella minnesota, Pseudomonas aeruginosa, Neisseria meningitidis, Bacteroides fragilis, and Rhodobacter sphaeroides show that the strongest CD14-dependent responses require a typical O-antigen, long carbohydrate chains, at least 6 acyl chains in their lipid A, and 2-phosphorylated Kdo moieties; wild-type LPS lacking a typical O-antigen and containing short carbohydrate chains and 2-phosphorylated Kdo moieties induces the strongest CD14-independent response.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Gram-Negative Bacteria / immunology*
  • Lipopolysaccharide Receptors / physiology*
  • Lipopolysaccharides / chemistry*
  • Lipopolysaccharides / metabolism
  • Macrophage Activation
  • Macrophages, Peritoneal / immunology*
  • Mice
  • Mice, Inbred BALB C


  • Lipopolysaccharide Receptors
  • Lipopolysaccharides