MRC1 and infection: Similarly, 1.0 mg/kg and 10 mg/kg groups maintained their CD163+ MRC1+ alveolar macrophage populations across the course of infection, while the 0.1 mg/kg dose and control groups exhibited significant reductions in this population compared to 10 mg/kg treated animals at 2 dpi (p = .007937 and p = .008658 respectively) (Fig 2C and 2F).