Figure 1.

Kinetics of inflammatory responses triggered by influenza A virus (IAV) infection. Mice were infected with IAV (10⁴ and 10⁶ PFU) or instilled with PBS (Mock) and after 1, 3, 4, 5, 7, and 10 days of infection were euthanized. Levels of the chemokines CXCL1 and CXCL2 (A,D), number of neutrophils and mononuclear cells in the airways (B,E) and myeloperoxidase assay (MPO) levels in lungs (C,F) were evaluated at different times after infection (n = 5–6 mice per group—representative of two experiments). Results are expressed as the number of cells, levels of cytokines (pg/ml), absorbance or percentage of initial weight, and are shown as the mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001, when compared with Mock mice or indicated groups.