Figure 2

Kinetics of pulmonary immune cells in mice with fatal dose (5 × 10⁵p.f.u.) of A/PR/8/34 (H1N1) virus infection. The frequencies of macrophages (CD11b⁺/CD11c⁻/Ly6G/c⁻) and neutrophils (CD11b⁺/CD11c⁻/Ly6G/c⁺) were determined by appropriate gating within the total lung leukocytes. For determination of the frequencies of CD4⁺ and CD8⁺ T cells, the CD3⁺ T cells were first determined by appropriate gating within the pulmonary lymphocytes, and then CD4⁺/CD8⁻T cells and CD4⁻/CD8⁺ T cells were detected by gating within the CD3⁺ T cells. In the detection of frequency of CD138⁺ cells and CD38⁺ cells, B220/CD45R was used to identify different B cell subtypes within the pulmonary lymphocytes, then CD138⁺ and CD38⁺ B cells were determined by appropriate gating within the determined B cell subtype, respectively. Mice without infection were used as the control group. Mean lung cell numbers were representative of at least 3 mice lungs per time point group, and error bars indicated the standard deviations. The dotted lines were the control level. *p < 0.05 compared with control group.