Cytokine-binding proteins in the lung. Bonner, James C., and Arnold R. Brody. Laboratory of Pulmonary Pathobiology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, Lung Biology Program, Department of Pathology, Tulane University Medical Center, New Orleans, Louisiana 70112
APStracts 2:0034L, 1995.
Numerous cytokines and growth factors signal the normal processes of tissue maintenance and remodeling in the lung, yet the abberant expression of these peptide mediators are involved in a variety of pulmonary diseases. Furthermore, several different binding proteins function in controlling the extracellular levels of many of these cytokines in the lung. For example, a variety of cytokines and growth factors bind to and are regulated by the ubiquitous proteinase inhibitor, [alpha]2-macroglobulin. The insulin-like growth factors are controlled by a specific class of six different insulin-like growth factor binding proteins. The transforming growth factor-[beta] family and fibroblast growth factors interact with extracellular matrix proteins. Several growth factor receptors are shed into the extracellular milleau where they retain a functional binding domain and thereby act as specific binding proteins. Cytokine-binding proteins appear to have a diversity of functions and may serve as extracellular cytokine reservoirs, protective shields against proteolytic degradation of cytokines, modifiers of cytokine-induced biological activity, or as clearance avenues for cytokines. The wide spectrum of cytokine-regulating molecules are important in cell-cell communications under normal conditions, whereas cytokine-binding protein dysfunction could contribute to a number of pulmonary diseases.

Received 3 March 1995; accepted in final form 4 March 1995.
APS Manuscript Number L73-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 March 1995.