Figure 2.

Plasminogen activator protease (Pla) suppresses early neutrophil infiltration into the lungs. A, Flow cytometry plots representing neutrophil abundance in the bronchoalveolar lavage fluid (BALF) of a single mouse infected intranasally with 5 × 10⁴ colony-forming units (CFUs) of CO92 wild type (WT) or CO92 Δpla at 4 and 12 hours after infection. Gate contains F4/80⁻CD11b^highLy-6G⁺ cells (neutrophils), and the percentage of the F4/80⁻ population is shown. Abbreviation: Cy7, cyanine 7; PE, phycoerythrin; WT, wild type. B, Quantification of the abundance of neutrophils in the BALF of mice, as described in A. Plot represents the number of neutrophils found in every 1000 live cells in the BALF of 10 mice. C, D, Quantification of the abundance of other CD45⁺CD3⁻ cell types in the BALF of mice, as described in A. Plots represent the number of each cell type found in every 1000 live cells in the BALF at 4 hours (C) and 12 hours (D) after infection. Populations were identified as alveolar macrophages (F4/80⁺CD11c^highCD11b^low), interstitial macrophages (F4/80⁺CD11c^lowCD11b^high), monocytes (F4/80⁻CD11b^highCD11c^lowLy-6G⁻), and dendritic cells (F4/80⁻CD11c^highCD11b^{high or low}). All experiments were performed ≥3 times. Error bars represent standard deviations. (n = 5 or 10). *P < .001 (Welch t test).