Organ-specific tissue-resident macrophages dynamics during blood stage malaria

Blood-stage malaria initiates both innate and adaptive immune responses, inclusive a strong activation of the mononuclear phagocyte network. Here we show that Plasmodium infection results in a transient loss of embryonically established tissue-resident macrophages in spleen, liver and lungs, much before the peak of parasitemia. During acute blood-stage malaria, fate mapping analysis revealed that inflammatory monocytes contribute to the repopulation of the emptied niches of splenic red pulp macrophages and hepatic Kupffer cells, while lung alveolar macrophages refill their niche mainly through self-renewal. Interestingly, the local microenvironment of spleen and liver can “imprint” the molecular characteristics of fetal-derived macrophages in new immigrants from bone marrow including almost identical gene expression profiles and turnover kinetics. Mice were infected with parasitized P. yoelii erythrocytes. Organ samples were collected in triplicates from uninfected mice and from mice infected 35 days before and after parasite clearance.