The deleterious role of plasminogen is independent on virus replication.

<p>(A) Virus replication of IAV A/PR/8/34 and A/Netherlands/602/09 after inoculation of A549 cells in presence or absence (triangle) of plasminogen (square) or trypsin (circle). Data represent mean ± s.e.m of three independent experiments. (B) Western blot analysis of A/PR/8/34 and A/Netherlands/602/09 HA cleavage after infection of A549 cells in presence or absence of plasminogen (PLG) or trypsin (Try). Membranes were probed with anti-HA and anti-tubulin antibodies. kDa (apparent molecular weight). NI stands for uninfected. (C) Infectious A/PR/8/34 (n = 3–5) and A/Netherlands/602/09 (n = 3) lung virus titers at the indicated time points post-inoculation of WT (black bars) or PLG-KO mice (white bars). Data represent mean ± s.e.m of 3–5 individual mice per group. n = mice per group and per time-point.