I am analyzing bronchoalveolar lavage fluids from infected mice to evaluate leukocyte infiltration with flow cytometry. I am staining BALF cells with anti CD45 (pan leukocytes), CD11b (myeloid cells), Ly6G (PMN), CD3 (lymphocytes), and F4/80 (macrophages).
I see two, very distinct macrophage populations: one that is F4/80 bright CD11b+ and one CD11b bright but F4/80 negative and have lower FSC and SSC intensity.
I thought the F4/80 bright/CD11b+ are the resident alveolar macrophages, while the second population represents macrophages derived from monocytes (that haven't acquired F4/80 yet). Am I correct? Is there any additional marker/criteria I can use to distinguish these two cell subsets?