Interleukin-8 gene expression by a pulmonary epithelial cell line : a model for cytokine networks in the lung

• Published in: The Journal of clinical investigation Vol. 86; no. 6; pp. 1945 - 1953
• Main Authors: STANDIFORD, T. J, KUNKEL, S. L, BASHA, M. A, CHENSUE, S. W, LUNCH, J. P, TOEWS, G. B, WESTWICK, J, STRIETER, R. M
• Format: Journal Article
• Language: English
• Published: Ann Arbor, MI American Society for Clinical Investigation 01.12.1990
• Subjects: Biological and medical sciences; Blotting, Northern; Cell Communication; Cell Line; Chemotaxis, Leukocyte; Cytokines - physiology; Dose-Response Relationship, Drug; Epithelium - physiology; Fundamental and applied biological sciences. Psychology; Gene Expression; Humans; Immunologic Techniques; In Vitro Techniques; Interleukin-1 - pharmacology; Interleukin-8 - genetics; Lung - physiology; Macrophages - physiology; Molecular and cellular biology; Molecular genetics; Pulmonary Alveoli - cytology; RNA, Messenger - genetics; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha - pharmacology; Tumor necrosis factor; Interleukin; Lung; Epithelial cell; Models; Molecular biology; Gene expression
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/jci114928

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.