AJP - Lung Cellular and Molecular Physiology, Vol 263, Issue 4 471-L478, Copyright © 1992 by American Physiological Society

ARTICLES

Cigarette smoking decreases bioactive interleukin-6 secretion by alveolar macrophages

D. M. Soliman and H. L. Twigg 3rd
Department of Medicine, Indiana University Medical Center, Indianapolis 46202.

Studies suggest smokers have decreased alveolar macrophage (AM) accessory cell (AC) function and a reduced incidence of immune-mediated lung diseases such as sarcoidosis. Impaired AM secretion of cytokines important in T-cell immune responses could explain this observation. We investigated production and secretion of interleukin-1 (IL-1) and interleukin-6 (IL-6) in smokers and nonsmokers. Lipopolysaccharide-induced AM IL-1 secretion in smokers was significantly reduced compared with nonsmoker AM. However, intracellular IL-1 in smoker AM was higher than in nonsmokers, suggesting that reduced IL-1 secretion was due to impaired release rather than reduced production. Smoker AM secreted significantly less bioactive IL-6 measured in a bioassay compared with nonsmoker AM. Intracellular IL-6 was virtually undetectable in both groups. In some smokers IL-6 production determined by immunoprecipitation was reduced. However, as a group antigenic IL-6 secretion determined by enzyme-linked immunoabsorbent assay was similar in smokers and nonsmokers, suggesting that smoker AM may cosecrete an inhibitor of IL-6 bioactivity. Indeed, AM supernatants from smokers inhibited B9 proliferation in response to maximal recombinant IL-6 stimulation, whereas supernatants from nonsmokers did not. We conclude that AM from smokers secrete less cytokines important in T-cell proliferation than AM from nonsmokers and suggest that for IL-6 this impairment is related to both decreased production of antigenic protein as well as cosecretion of an IL-6 inhibitor.

This article has been cited by other articles:

				H. M. Wu, M. Jin, and C. B. Marsh Toward functional proteomics of alveolar macrophages Am J Physiol Lung Cell Mol Physiol, April 1, 2005; 288(4): L585 - L595. [Abstract] [Full Text] [PDF]

				K. Matsunaga, T. W. Klein, H. Friedman, and Y. Yamamoto Epigallocatechin Gallate, a Potential Immunomodulatory Agent of Tea Components, Diminishes Cigarette Smoke Condensate-Induced Suppression of Anti-Legionella pneumophila Activity and Cytokine Responses of Alveolar Macrophages Clin. Vaccine Immunol., July 1, 2002; 9(4): 864 - 871. [Abstract] [Full Text] [PDF]