Bacterial pneumonia induces senescence in resident alveolar macrophages that are outcompeted by monocytes

This study show that embryonic-derived resident alveolar macrophages recovered from acute respiratory Streptococcal pneumoniae infection show features of cell senescence and reduced proliferation capacity. In the weeks after resolution of infection, these senescent resident alveolar macrophages are outcompeted by monocyte-derived alveolar macrophages with hyper-immunoreactivity and heterologous anti-infectious functions. After mice were infected with Streptococcus pneumoniae/PBS, AMs in the lungs were isolated at different time points and subjected to RNA-seq.