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Although macrophages are widely recognized to have a profibrotic role in inflammation, we have used a highly tractable CCl₄-induced model of reversible hepatic fibrosis to identify and characterize the macrophage phenotype responsible for tissue remodeling: the hitherto elusive restorative macrophage. This CD11B^hi F4/80^int Ly-6C^lo macrophage subset was most abundant in livers during maximal fibrosis resolution and represented the principle matrix metalloproteinase (MMP) -expressing subset. Depletion of this population in CD11B promoter–diphtheria toxin receptor (CD11B-DTR) transgenic mice caused a failure of scar remodeling. Adoptive transfer and in situ labeling experiments showed that these restorative macrophages derive from recruited Ly-6C^hi monocytes, a common origin with profibrotic Ly-6C^hi macrophages, indicative of a phenotypic switch in vivo conferring proresolution properties …