A macrophage subpopulation recruited by CC chemokine ligand-2 clears apoptotic cells in noninfectious lung injury

J Liang, Y Jung, RM Tighe, T Xie… - … of Physiology-Lung …, 2012 - journals.physiology.org
J Liang, Y Jung, RM Tighe, T Xie, N Liu, M Leonard, MD Gunn, D Jiang, PW Noble
American Journal of Physiology-Lung Cellular and Molecular …, 2012journals.physiology.org
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 …
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/IEintCD11cint 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/IEintCD11cint cells engulfed apoptotic cells during acute lung injury. Our data suggested a previously undiscovered role for MHCII IA/IEintCD11cint cells in apoptotic cell clearance and inflammation resolution.
American Physiological Society