Figure 4.

Alveolar macrophages and neutrophils are both infected with Brucella melitensis in the lungs of Alt-sensitized BALB/c mice. Wild-type BALB/c mice received repeated i.n. administration of Alt before i.n. infection with 2 × 10⁴ CFU of mCherry-B. melitensis. The mice were sacrificed at 12 days post infection. The lungs were harvested, fixed, and frozen sections were immunostained and examined by confocal microscopy. (A,B) Representative confocal images of single optical sections of mCherry-Br infected CD11c⁺ cells and Ly-6G⁺ cells stained with DAPI from Alt sensitized wild-type BALB/c mice. (C) Representative infected multinucleated giant cells stained with DAPI and phalloidin. The panels are color-coded for DAPI, phalloidin, the cell surface antigen examined or mCherry-Brucella. Scale bars = 10 µm, as indicated.