IMR Press / FBL / Volume 11 / Issue 2 / DOI: 10.2741/1904

Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on as a courtesy and upon agreement with Frontiers in Bioscience.

Neutrophil depletion inhibits early and late monocyte/macrophage increase in lung inflammation
Show Less
1 Immunology Research Group, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
Front. Biosci. (Landmark Ed) 2006, 11(2), 1569–1576;
Published: 1 May 2006

Monocytes/macrophages have critical impact on outcomes of lung inflammation. Kinetics and mechanisms for the increase of monocytes/macrophages in lungs are not completely understood. To better understand these mechanisms, E. coli-LPS (250 micro grams; N = 35) or endotoxin-free saline (N = 5) were instilled intratracheally in Sprague-Dawley rats and the increase in monocytes/macrophages, neutrophils and monocyte chemotactic protein-1 (MCP-1) was quantified at various time points after LPS treatment. In contrast to typical pattern of neutrophil influx between 6 and 24 hours, monocytes/macrophages increased in two distinct phases, very early at 3 hours and late at 24 hours. The role of neutrophils in monocyte/macrophage increase was addressed in LPS-challenged neutropenic rats (N = 8). Neutrophil depletion before instillation of LPS abrogated the early as well as late monocyte/macrophage increases in the lung. Quantification of MCP-1, which is one of the major chemoattractants for monocytes, in lung homogenates showed similar concentrations in neutropenic and non-neutropenic LPS-challenged rats. These findings show that increase in monocytes/macrophages in lung occurs in two, early and late phases, both being dependent on neutrophils but not on MCP-1.

Monocyte chemotactic protein-1
Polymorphonuclear leukocytes
Electron microscopy
Back to top