Interleukin-8 and the neutrophil response to mucosal gram-negative infection

J Clin Invest. 1993 Aug;92(2):780-5. doi: 10.1172/JCI116650.

Abstract

Urinary tract infections activate a mucosal inflammatory response, which includes cytokine secretion and neutrophil influx. The mechanisms involved in the neutrophil influx have not been identified. Interleukin-8, a potent chemoattractant for neutrophils, is produced by urinary tract epithelial cell lines in vitro. This study analyzed the human IL-8 response to deliberate Escherichia coli infection of the urinary tract. Urine and serum samples were obtained before and after intravesical instillation of E. coli. Neutrophil numbers were determined on uncentrifuged urine, and IL-8 levels were measured by ELISA. A urinary IL-8 response was found in all patients after bacterial instillation, but no serum IL-8 was detected. There was a strong correlation between urinary IL-8 levels and urinary neutrophil numbers. The same E. coli strains used to colonize the patients stimulated IL-8 production in urinary tract epithelial cells. The level of IL-8 secreted by epithelial cell lines was influenced by the fimbrial properties of the E. coli. These results demonstrated that E. coli elicit a mucosal IL-8 response in humans, and suggested that IL-8 is involved in the onset of pyuria. Epithelial cells may be an important source of IL-8 during urinary tract infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Enzyme-Linked Immunosorbent Assay
  • Epithelium / metabolism
  • Epithelium / pathology
  • Escherichia coli Infections / immunology
  • Escherichia coli Infections / physiopathology*
  • Escherichia coli Infections / urine
  • Female
  • Humans
  • Immunohistochemistry
  • Interleukin-8 / analysis
  • Interleukin-8 / biosynthesis*
  • Interleukin-8 / blood
  • Neutrophils / physiology*
  • Urinary Tract / microbiology
  • Urinary Tract / pathology
  • Urinary Tract / physiopathology
  • Urinary Tract Infections / immunology
  • Urinary Tract Infections / physiopathology*
  • Urinary Tract Infections / urine

Substances

  • Interleukin-8