FIG. 7.

Dynamics of neutrophil and macrophage infiltration during acute S. aureus pulmonary infection. (A) Cells isolated from the lungs of naïve and S. aureus-infected WT and Pilrb^−/− mice were divided into two main populations. Cells defined as FSC^loSSC^lo were gated as R2 (primarily comprising the lymphocyte and monocyte populations), and those defined as FSC^mid-hiSSC^mid-hi were gated as R3 (primarily comprising the granulocyte population). The R3 population was significantly increased in infected mice compared to that in naïve mice. (B and D) Plots showing a significant increase in the CD11b⁺Gr1^lo-int (macrophage) population in the Pilrb^−/− mice (white squares) compared to that in the WT mice (gray squares) at 24 h in the R2 gate and at both 24 and 48 h in the R3 gate. (C and E) Plots showing cellular infiltration in R2 and R3 gates, with a significant increase in the CD11b⁺Gr1^+hi (neutrophil) population in Pilrb^−/− mice at 24 h postinfection. The plots are representative of three to four separate experiments with five to six mice per group at each time point. Data are expressed as means ± SEM. *, P ≤ 0.05; **, P ≤ 0.001.