Fig. 1.

Therapeutic model of GM-CSF during IAV infection using an inducible airway GM-CSF over-expression transgenic mouse model, and effects on survival and body mass during IAV infection. To simulate a therapeutic model of GM-CSF administration doxycycline was administered to both DTGM and LM control mice starting 3 days after i.n. infection with PR8 IAV. Doxycycline-containing water was protected from light and changed every three days (a). DTGM (n = 23, red circles/lines) and LM control (n = 15, black squares/lines) mice were administered approximately 2 LD₅₀ of IAV PR8 virus i.n. and administered doxycycline in water starting on +3 dpi, and the effects on survival and body weight are shown. Mice were euthanized if they lost >30% body weight and were moribund. GM-CSF over-expression (DTGM mice) conferred a significant survival benefit (b) but not a significant effect on weight loss/recovery (c) as compared to wild-type levels (LM mice). Results shown represent three independent experiments (**p < 0.005)