Figure 4.

CD11c⁺ macrophages and DCs are induced by PCN administration. Mice are dosed five times daily with PCN or PBS a week before MRSA infection. Mice are sacrificed at designated time points after infection, and cells isolated from BALF are stained and analyzed by FACS. The gating strategy is as follows. A: The live cells gate is set on FCS (forward scatter; representing cell volume) versus SSC (side scatter; representing the inner complexity of the particle like granularity of a cell). Staining for CD11c versus CD11b is determined by gating total live cells. Representative FACS plots are shown. B: The expression of SiglecF is evaluated on live CD11c⁺ F4/80⁺ or CD11c⁺ F4/80⁻ cells. C: Live cells are gated for F4/80⁺ cells and then for CD11c⁺ versus MHCII⁺ cells. CD11c⁺MHCII^low AMs are shown for PCN-dosed mice, and CD11c⁺MHCII^high DCs are shown for PBS-dosed mice. D: In an independent experiment, the presence of M1 (CD11c⁺CD206⁻) and M2 (CD11c⁺CD206⁺) cells is determined after gating on live F4/80⁺ cells. Each panel represents the results from a single experiment (mean ± SD from five mice per group). Each experiment is repeated two to three times. **P < 0.01, ***P < 0.001 versus PBS-dosed mice.