Interleukin-8 Gene Expression by a Pulmonary Epithelial Cell Line. A Model for Cytokine Networks in the Lung

J Clin Invest. 1990 Dec;86(6):1945-53. doi: 10.1172/JCI114928.

Abstract

Cellular constituents of the alveolar-capillary wall may be key participants in the recruitment of polymorphonuclear leukocytes to the lung through the generation of the novel neutrophil chemotactic peptide interleukin-8 (IL-8). This interaction appears to occur via the ability of human alveolar macrophage (AM)-derived monokines, tumor necrosis factor (TNF), and interleukin-1 (IL-1) to induce gene expression of IL-8 from pulmonary type II-like epithelial cells (A549). Northern blot analysis demonstrated that steady-state IL-8 mRNA expression, by either TNF- or IL-1 beta-treated A549 cells, occurred in both a dose- and time-dependent fashion. Similarly, extracellular antigenic IL-8, as assessed by specific ELISA, was expressed from TNF- or IL-1 beta-stimulated epithelial cells in a time-dependent fashion with maximal IL-8 antigen detected at 24 h poststimulation. Immunohistochemical staining utilizing rabbit anti-human IL-8 antibody identified immunoreactive, cell-associated IL-8 antigen as early as 8 h post-TNF or IL-1 beta stimulation. A549-generated neutrophil chemotactic bioactivity paralleled IL-8 steady-state mRNA levels. Signal specificity was demonstrated in this system as IL-8 mRNA or protein expression by lipopolysaccharide (LPS)-treated A549 cells was not different from unstimulated cells. Although LPS did not serve as a direct stimulus for the production of IL-8 by type II-like epithelial cells, the condition media from LPS-challenged AM induced a significant expression of IL-8 mRNA by the A549 cells. 24-h conditioned media from LPS-treated cells was as potent as either IL-1 beta or TNF in generating steady-state IL-8 mRNA by A549 cells. Preincubation of LPS-treated AM-conditioned media with anti-human TNF or IL-1 beta neutralizing antibodies resulted in significant abrogation of IL-8 gene expression by A549 pulmonary epithelial cells. These findings demonstrate potential cell-to-cell communication circuits that may be important between AMs and pulmonary epithelial cells during the recruitment phase of acute lung inflammation.

Publication types

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

MeSH terms

  • Blotting, Northern
  • Cell Communication
  • Cell Line
  • Chemotaxis, Leukocyte
  • Cytokines / physiology*
  • Dose-Response Relationship, Drug
  • Epithelium / physiology
  • Gene Expression
  • Humans
  • Immunologic Techniques
  • In Vitro Techniques
  • Interleukin-1 / pharmacology
  • Interleukin-8 / genetics*
  • Lung / physiology*
  • Macrophages / physiology
  • Pulmonary Alveoli / cytology
  • RNA, Messenger / genetics
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Cytokines
  • Interleukin-1
  • Interleukin-8
  • RNA, Messenger
  • Tumor Necrosis Factor-alpha