M2 Polarization of Human Macrophages Favors Survival of the Intracellular Pathogen Chlamydia pneumoniae
Fig 1
(A) CD14 positive human blood monocytes were treated either with 25 ng/mL GM-CSF or 50 ng/mL M-CSF for 7 days to yield M1-like or M2-like macrophages. M1-like macrophages were activated with GM-CSF, LPS and 50 ng/mL IFN-γ for an additional 48 h to yield M1 macrophages, while M2-like macrophages were treated with M-CSF and IL-4 to yield M2. (B) To examine the impact of macrophage polarization on survival and proliferation of C. pneumoniae, M1 and M2 macrophages were infected and cultured with C. pneumoniae for 24 h. (C) M1-like macrophages were infected with C. pneumoniae and cultured for 48 h in the presence of GM-CSF and IFN-γ, while infected M2-like macrophages were cultured with M-CSF and IL-4. Uninfected macrophages served as control.