To examine the functional changes in macrophages following a chlamydial lung infection, we explored the polarisation status of the macrophage subpopulations (AMs, IMs, and Mo/Mφ) at early and later stages of infection using iNOS and CD206 as respective M1 and M2 macrophage markers (Figure 3, Figure 4 and Figure 5). This evidence concerns the gene MRC1 and infection.