Additional file 4: Figure S2A and B. of GM-CSF overexpression after influenza a virus infection prevents mortality and moderates M1-like airway monocyte/macrophage polarization

Characterization of the Double Transgenic GM-csf (DTGM) mouse model. In the absence of influenza A virus infection, GM-CSF levels (A) in bronchoalveolar lavage (BAL) fluid was low, near the limit of detection in littermate (LM) and DTGM mice. Upon influenza A virus infection DTGM mice without doxycycline-induction (DTGM noDox) demonstrate "leakiness" that corresponds to the peak of type II interferon levels at days 7-8 post-infection. DTGM +Dox mice demonstrate supra-physiologic levels of GM-CSF in BAL fluid at all time points after induction. DTGM mice were less susceptible to IAV infection (B) even in the absence of doxycycline induction, whereas doxycycline administration to LM mice had no effect. (ZIP 55Â kb)