Abstract
We have studied the expression of the lipopolysaccharide (LPS) receptor CD14 on monocytes (Mo) and alveolar macrophages (AM), including density- and size-defined subpopulations. Bronchoalveolar lavage (BAL) was performed on eleven healthy non-smokers and blood sampled from 5 of them, and the levels of cell CD14 expression was investigated using flow cytometry. The influence of LPS stimulation on the CD14 expression of AM was studied at various intervals during prolonged incubation. Further, the relationship between CD14 expression and LPS binding to Mo and subpopulations of AM was studied by measuring fluorescein isothiocyanate (FITC)-LPS binding (flow cytometry) and binding of radioiodinated LPS (I25I-LPS). The CD14 expression was 13-fold higher (P < 0.02) on Mo than on unfractionated and high density AM. The CD14 level on the latter was higher than on low density AM, and also higher (P < 0.05) on small AM compared to large (flow cytometrically defined) AM. LPS stimulation had a downregulating effect on AM CD14 level, but after several hours of continuing decreased expression, an increased (P < 0.05) CD14 expression was demonstrated, indicating de novo synthesis. The binding of LPS to subpopulations of AM and isolated Mo was not significantly different, but the binding of FITC-LPS to Mo in whole blood was higher than to AM (P < 0.02). The presented results indicate that AM of different size and maturity have different and variable (activation dependent) CD14 levels. The LPS binding capacity was, however, not proportional to the CD14 expression, indicating that LPS binding mechanisms unrelated to CD14 levels were also operable.
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REFERENCES
Martin, T. R., G. Rubenfeld, K. P. Steinberg, L. D. Hudson, G. Raghu, A. M. Moriarty, D. J. Leturcq, P. S. Tobias, and R. J. Ulevitch. 1994. Endotoxin, endotoxin-binding protein, and soluble CD14 are present in bronchoalveolar lavage fluid of patients with adult respiratory distress syndrome. Chest 105:3:55S–56S.
Chen, T-Y., M-G. Lei, T. Suzuki, and D. C. Morrison. 1992. Lipopolysaccharide receptors and signal transduction pathways in mononuclear phagocytes. Current Topics in Microbiology and Immunology 181:169–187.
Simmons, D. L., S. Tan, D. G. Tenen, A. Nicholson Weller, and B. Seed. 1989. Monocyte antigen CD14 is a phospholipid anchored membrane protein. Blood 73:284–289.
Haziot A., S. Chen, E. Ferrero, M. G. Low, R. Silber, and S. M. Goyert. 1988. The monocyte differentiation antigen, CD14, is anchored to the cell membrane by a phosphatidylinositol linkage. J. Immunol. 141:547–552.
Wright, S. D., R. A. Ramos, P. S. Tobias, R. J. Ulevitch, and J. C. Mathison. 1990. CD14, a receptor for complexes of lipopolysaccharide (LPS) and LPS binding protein. Science 249:1431–1433.
Haziot, A., B-Z. Tsuberi, and S. M. Goyert. 1993. Neutrophil CD14: Biochemical Properties and Role in the Secretion of Tumor Necrosis Factor-α in Response to Lipopolysaccharide. J. Immunol. 150:5556–5565.
Martin, T. R., J. C. Mathison, P. S. Tobias, D. J. Leturcq, A. M. Moriarty, R. J. Maunder and R. J. Ulevitch. 1992. Lipopolysaccharide binding protein enhances the responsiveness of alveolar macrophages to bacterial lipopolysaccharide. J. Clin. Invest. 90:2209–2219.
Dentener M. A., V. Bazil, E. J. U. Von Asmuth, M. Ceska, and W. A. Buurman. 1993. Involvement of CD14 in lipopolysaccharide-induced tumor necrosis factor-α, IL-6 and IL-8 release by human monocytes and alveolar macrophages. J. Immunol. 150:2885–2891.
Sibille Y., and H. Y. Reynolds. 1990. Macrophages and polymorphonuclear neutrophils in lung defence and injury. Am. Rev. Respir. Dis. 141:471–501.
Nakstad B., T. Lyberg, F. SkjØrten, and N. P. Boye. 1989. Subpopulations of human lung alveolar macrophages: Ultrastructural Features. Ultrastruct. Pathol. 13:1–13.
Calhoun W. J., H. E. Reed, D. R. Moest, and C. A. Stevens. 1992. Enhanced Superoxide Production by Alveolar Macrophages and Air-Space Cells, Airway Inflammation, and Alveolar Macrophage Density Changes after Segmental Antigen Bronchoprovocation in Allergic Subjects. Am. Rev. Respir. Dis. 145:317–325.
Kuo H. P. and C. T. Yu. 1993. Alveolar macrophage subpopulations in patients with active pulmonary tuberculosis. Chest 104(6):1773–1778.
BØyum A. 1968. Isolation of mononuclear cells and granulocytes from human blood. J. Clin. Invest. (Suppl.) 97:77.
Ulevitch R. J. 1978. The preparation and characterization of radioiodinated bacterial lipolysaccharide. Immunochemistry 15:157–164.
Espevik T., and J. Nissen-Meyer. 1986. A highly sensitive cell line, WEHI 164 clone 13, for measuring cytotoxic factor/tumor necrosis factor from human monocytes. J. Imm. Meth. 95:99–105.
HalldÉn, G., C. M. SkÖld, A. Eklund, J. Forslid, and J. Hed. 1991. Quenching of intracellular autofluorescence in alveolar macrophages permits analysis of fluorochrome labeled surface antigens by flow cytofluorometry. J. Immun. Meth. 142:207–214.
Smith, P. K., R. I. Krohn, G. T. Hermanson, A. K. Mallia, F. H. Gartner, M. D. Provenzano, E. K. Fujimoto, N. M. Goeke, B. J. Olson, and D. C. Klenk. 1985. Measurement of protein using bicinchoninic acid. Anal. Biochem. 150:76–85.
Wassermann, K., M. Subklewe, G. Pothoff, N. Banik and E. Schell-Frederick. 1994. Expression of surface markers on alveolar macrophages from symptomatic patients with HIV infection as detected by flow cytometry. Chest 105:1324–1334.
Ziegler-Heitbrock H. W. L., and R. J. Ulevitch. 1993. CD14: Cell surface receptor and differentiation marker. Immunol. Today 14:3: 121–125.
Bitterman, P. B., L. E. Salzman, S. Adelberg, V. J. Ferrans, and R. G. Crystal. 1984. Alveolar macrophage replication: one mechanism for the expansion of the mononuclear phagocyte population in the chronically inflamed lung. J. Clin. Invest. 74:460–469.
Striz I., L. Zheng, Y. M. Wang, H. Pokorna, P. C. Bauer, and U. Costabel. 1995. Soluble CD14 is increased in bronchoalveolar lavage of active sarcoidosis and correlates with alveolar macrophage membrane-bound CD14. Am. J. Respir. Crit. Care Med. 151:544–547.
Haugen T., B. Nakstad, O. H. SkjØnsberg, and T. Lyberg. 1993. Lungemakrofagers CD14 ekspresjon og cytokinproduksjon. Lungeforum 4(1): 12.
Hopkins H. H., M. M. Monick, and G. W. Hunninghake. 1995. Lipopolysaccharide upregulates surface expression of CD14 on human alveolar macrophages. Am. J. Physiol. 269 (Lung Cell Mol. Physiol. 13):L849–L854.
HØgevold H. E., and T. Lyberg. 1993. Monocyttenes ekspresjon av CD14 ved endotoxin-stimulering. De Norske Kirurgiske Foreninger Vitenskapelige Forhandlinger 253.
Lohmann-Matthes M-L., C. SteinmÜller, and G. Franke-Ullmann. 1994. Pulmonary macrophages. Eur. Respir. J. 7:1678–1689.
Morrison D. C. 1985. Non-specific interactions of bacterial lipopolysaccharides with membranes and membrane components. In Berry LJ, Editor Handbook of Endotoxin, vol. 3. Elsevier Science, New York 25–55.
Vasselon T., R. Pironkova, and P. A. Detmers. 1997. Sensitive responses of leukocytes to lipopolysaccharide require a protein distinct from CD14 at the cell surface. J. Immunol. 159:4498–4505.
Hampton, R. Y., D. T. Golenbock, and R. H. Raetz. 1988. Lipid A binding sites in membranes of macrophage tumor cells. J. Biol. Chem. 263:29: 14802–14807.
Wright, S. D. 1991. Multiple receptors for endotoxin. Curr. Opin. Immunol. 3:83–90.
Marchant A., J. Duchow, J. P. Delville, and M. Goldman. 1992. Lipopolysaccharide induces up-regulation of CD14 molecule on monocytes in human whole blood. Eur. J. Immunol. 22:1663–1665.
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Haugen, T.S., Nakstad, B., Skjønsberg, O.H. et al. CD14 Expression and Binding of Lipopolysaccharide to Alveolar Macrophages and Monocytes. Inflammation 22, 521–532 (1998). https://doi.org/10.1023/A:1022302228051
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DOI: https://doi.org/10.1023/A:1022302228051