Open AccessA macrophage subpopulation recruited by CC chemokine ligand-2 clears apoptotic cells in noninfectious lung injury
Author(s) -
Jiurong Liang,
Yoosun Jung,
Robert Tighe,
Ting Xie,
Ningshan Liu,
Maura Leonard,
Michael D. Gunn,
Dianhua Jiang,
Paul W. Noble
Publication year - 2012
Publication title -
american journal of physiology. lung cellular and molecular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.892
H-Index - 163
eISSN - 1522-1504
pISSN - 1040-0605
DOI - 10.1152/ajplung.00256.2011
Subject(s) - chemokine , apoptosis , macrophage , lung , ligand (biochemistry) , medicine , cancer research , immunology , microbiology and biotechnology , chemistry , biology , inflammation , receptor , biochemistry , in vitro
CC chemokine ligand-2 (CCL2)/monocyte chemoattractant protein (MCP)-1 expression is upregulated during pulmonary inflammation, and the CCL2-CCR2 axis plays a critical role in leukocyte recruitment and promotion of host defense against infection. The role of CCL2 in mediating macrophage subpopulations in the pathobiology of noninfectious lung injury is unknown. The goal of this study was to examine the role of CCL2 in noninfectious acute lung injury. Our results show that lung-specific overexpression of CCL2 protected mice from bleomycin-induced lung injury, characterized by significantly reduced mortality, reduced neutrophil accumulation, and decreased accumulation of the inflammatory mediators IL-6, CXCL2 (macrophage inflammatory protein-2), and CXCL1 (keratinocyte-derived chemokine). There were dramatic increases in the recruitment of myosin heavy chain (MHC) II IA/IE(int)CD11c(int) cells, exudative macrophages, and dendritic cells in Ccl2 transgenic mouse lungs both at baseline and after bleomycin treatment compared with levels in wild-type mice. We further demonstrated that MHCII IA/IE(int)CD11c(int) cells engulfed apoptotic cells during acute lung injury. Our data suggested a previously undiscovered role for MHCII IA/IE(int)CD11c(int) cells in apoptotic cell clearance and inflammation resolution.