Resident and recruited macrophages orchestrate the liver's defense against infection

Scientists have demonstrated that liver-resident macrophages are rapidly killed by the pathogenic bacterium Listeria monocytogenes. This early death triggers the recruitment of macrophages from the bloodstream to the liver. These macrophages start by bringing the bacterial infection under control; then, in an unexpected development, they actually replace the liver-resident macrophages that have been killed by the infection.