Functional characterization of interstitial macrophages and subpopulations of alveolar macrophages from rat lung

• Published in: Journal of leukocyte biology 1994-02, Vol.55 (2), p.141-146
• Main Authors: Prokhorova, Svetlana, Lavnikova, Natasha, Laskin, Debra L.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cell Separation; Cells, Cultured; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; IFN‐γ; Immunobiology; Interferon-gamma - pharmacology; lipopolysaccharide; Lipopolysaccharides - pharmacology; Lung - cytology; Lung - physiology; Macrophages - cytology; Macrophages - drug effects; Macrophages - physiology; Macrophages, Alveolar - cytology; Macrophages, Alveolar - drug effects; Macrophages, Alveolar - physiology; Monocytes, macrophages; Myeloid cells: ontogeny, maturation, markers, receptors; nitric oxide; Nitric Oxide - biosynthesis; Phagocytosis; Rats; Rats, Sprague-Dawley; Receptors, Fc - metabolism; Recombinant Proteins - pharmacology; superoxide anion; Superoxides - metabolism; Tetradecanoylphorbol Acetate - pharmacology; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.55.2.141

The specific function of interstitial macrophages (IM) in the lung is poorly understood because of difficulties in isolating these cells in high purity or large number. In the present studies, a pure population of en‐zymatically isolated IM and lung macrophages obtained mechanically from the lung were compared functionally with alveolar macrophages recovered by lavage (AM). Macrophages isolated mechanically from the tissue and AM displayed similarly high levels of Fc‐receptor mediated phagocytosis. In contrast, IM phagocytized significantly fewer opsonized sheep red blood cells per macrophage than AM. In addition, although some variations in the amounts of nitric oxide and superoxide anion produced by AM and macrophages obtained by mechanical tissue disruption were observed, these subpopulations released significantly more of these mediators than IM. These data support the concept that macrophages isolated by mechanical disruption of the tissue represent a subpopulation of AM. We also found that, in contrast to AM, IM did not respond synergistically to combinations of IFN‐γ and lipopolysaccharide (LPS) or tumor necrosis factor α in terms of nitric oxide production. Furthermore, regulation of superoxide anion release in AM and IM by LPS and/or IFN‐γ was distinct. Taken together, these studies demonstrate that IM are functionally different from other macrophage subpopulations which might reflect their unique location within the lung. J. Leukoc. Biol. 55: 141–146; 1994.