Figure 2. Neutrophilic inflammation in bronchoalveolar lavage (BAL) fluid following RSV-RFP infection. BALB/c mice were infected with RSV-RFP and bronchoalveolar lavage (BAL) were obtained up to 21 days post infection (dpi). (A) Total BAL cell numbers were significantly raised at 5 dpi. Differential cell types were assessed using Leishman’s stain. Macrophage number (B) and proportion (C) decreased with infection, but recovered by 21 dpi. Neutrophils number (D) and proportion (E) increased during infection before returning to baseline level by 21 dpi. Lymphocyte recruitment was more transient (F, G) peaking only at 5 dpi. Data are displayed as mean ± SEM; n= 6-9 per group. Statistical analysis was done by Kruskal-Wallis test with Dunn’s multiple comparison compared to baseline (0 dpi), *p<0.05.