AJP - Lung Cellular and Molecular Physiology, Vol 262, Issue 5 600-L605, Copyright © 1992 by American Physiological Society
IL-1 beta and IL-6 gene expression in alveolar macrophages: modulation by extracellular matrices
Z. Xing, M. Jordana and J. Gauldie
Department of Pathology, McMaster University, Hamilton, Ontario, Canada.
Interleukin-1 (IL-1) and interleukin-6 (IL-6) are two cytokines involved in
a variety of host inflammatory reactions. The alveolar macrophage (AM), a
predominant cell source for IL-1 and IL-6, exists in a microenvironment in
which there are abundant extracellular matrix (ECM) components, and it is
likely that ECM may participate in the inflammatory response in the lung by
modulating the effector activities of AMs. To investigate this hypothesis,
we cultured rat AMs on different substrates including plastic, collagen,
and airways fibroblast-derived ECM (fECM) and assessed IL-1 beta and IL-6
gene expression in these cells. Our study demonstrates that cytokine gene
expression in AMs is affected by the conditions of culture. IL-1 gene
expression is stimulated by adherence to plastic and exposure to endotoxin,
whereas IL-6 mRNA is detectable only in the cells stimulated by endotoxin.
Coating the plastic with collagen or fECM modifies cytokine gene
expression. At early time points, collagen enhances gene expression. At
later times (5 days), actin and cytokine gene expression are predominantly
maintained in the endotoxin-stimulated cells cultured on fECM. These
findings suggest an extracellular environment-directed mechanism of
regulation of cytokine expression in alveolar macrophages.
