Open AccessInflammatory Response to Fine Particulate Air Pollution Exposure: Neutrophil versus Monocyte
Author(s) -
Xiaohua Xu,
Silis Y. Jiang,
Tse-Yao Wang,
Yuntao Bai,
Mianhua Zhong,
Aixia Wang,
Morton Lippmann,
Lung Chi Chen,
Sanjay Rajagopalan,
Qinghua Sun
Publication year - 2013
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0071414
Subject(s) - bronchoalveolar lavage , immunology , monocyte , inflammation , immune system , flow cytometry , inhalation exposure , intravital microscopy , cytokine , medicine , inhalation , lung , microcirculation , anatomy
Objectives Studies have shown that chronic exposure to ambient fine particulate matter (less than 2.5 µ m in aerodynamic diameter, PM 2.5 ) pollution induces insulin resistance through alterations in inflammatory pathways. It is critical to study how the immune system responds to this stimulant, which has been linked to cardiovascular and autoimmune diseases, but few studies have been focused on such involvement of both neutrophils and monocytes in a timely manner. We hypothesized that the neutrophil was involved in the inflammatory response to air pollution. Methods and Results C57BL/6 mice were exposed to PM 2.5 or filtered air (6 hours/day, 5 days/week) for 5, 14, and 21 days, respectively, in Columbus, OH. At the end of each of the exposure periods, we investigated the inflammatory response through flow cytometry, histology, intravital microscopy, and real-time PCR. PM 2.5 -exposed mice demonstrated a significant inflammatory response after 5 days of exposure. In the lung tissue and bronchoalveolar lavage fluid, monocytes/macrophages showed a transient response, while neutrophils showed a cumulative response. In addition, exposure to PM 2.5 resulted in elevation of the monocyte chemoattractant protein 1 (MCP-1) cytokine, a monocyte/macrophage attractant in blood, at an early stage of exposure. Conclusions These findings suggest that PM 2.5 exposure induces the inflammatory responses from both macrophages and neutrophils involvement.