The interaction of macrophages and bacteria: Escherichia coli species, bacterial lipopolysaccharide, and lipid A differ in their ability to induce tumoricidal activity and the secretion of reactive nitrogen intermediates in macrophages

Cell Immunol. 1992 Apr 15;141(1):47-58. doi: 10.1016/0008-8749(92)90126-a.


The ability of nine Escherichia coli strains, and of bacterial lipopolysaccharide (LPS)3 and lipid A preparations, to elicit in a pure population of bone marrow-derived mononuclear phagocytes (BMM phi) tumoricidal activity and/or the generation of reactive nitrogen intermediates (RNI) was compared. Generally, low concentrations of E. coli organisms were able to trigger the generation of RNI: however, for induction of tumoricidal activity, higher concentrations were required. Nonisogenic E. coli species exhibited different ability; isogenic E. coli organisms that differed only in the expression of K antigen exhibited similar ability to elicit the macrophage activities. LPS proved to be highly efficient in triggering the secretion of reactive nitrogen intermediates; lipid A was clearly less potent, but evidence is presented to suggest that this was due to the diminished solubility of these reagents. On the other hand, all LPS and lipid A samples were very poor inducers of tumoricidal activity. Although RNI secretion and expression of tumoricidal activity are both strongly dependent on L-arginine, various evidence suggests that the two functions are not closely correlated and are induced by different bacterial structures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial*
  • Antigens, Surface / immunology
  • Dose-Response Relationship, Immunologic
  • Escherichia coli / immunology*
  • Lipid A / pharmacology*
  • Lipopolysaccharides*
  • Macrophage Activation / immunology
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Male
  • Nitrites / immunology*
  • Polymyxin B / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Tumor Necrosis Factor-alpha / immunology*


  • Antigens, Bacterial
  • Antigens, Surface
  • K antigens
  • Lipid A
  • Lipopolysaccharides
  • Nitrites
  • Tumor Necrosis Factor-alpha
  • Polymyxin B