(A) Drug treatment regimen with anti-neutrophil antibody (anti-Ly6G). Arrows denote days on which anti-Ly6G was i.p. injected, drug injections were performed, and 7,000 PFU Sendai virus (SeV) was intranasally inoculated in 5 μL PBS. (B) Peripheral blood neutrophil counts. (C) Peripheral blood lymphocyte counts. (D) Percent change in starting weight. (E-G) Bioluminescence in the nasopharynx (E), trachea (F), and lungs (G). Groups include PBS (black circles), Dexa + Cy (blue triangles), and Dexa + Cy + anti-Ly6G (red circles). The data shown are averages of 5 mice from each group. In all graphs, error bars represent the standard deviation. d.p.i., days postinfection; d.a.d.s., days after drug started.