TGF-β mediates increased resistance in asthmatic mice.

<p>(<b>A</b>) TGF-β1 levels in BALF of noninfluenza-infected asthmatic mice (4 mice/group) were determined by ELISA. The dotted line represents background TGF-β1 levels in BALF of non-asthmatic mice. (<b>B</b>) TGF-β1 levels in BALF after CA04 infection were determined by Luminex (3–4 mice/group). (<b>C</b>) Cell surface expression of LAP was measured on day 7 after the last OVA inoculation (4 mice/group). (<b>D</b> and <b>E</b>) Asthmatic mice (5–8 mice/group) infected at different time points after the last OVA treatment were monitored for survival (D) and weight loss (E). (<b>F</b> and <b>G</b>) Survival of <i>TβRII</i>^<i>f/f</i><i>-Cre</i> and control mice were monitored for survival after infection of either 2x10³ PFU (F) or 50 PFU (G) of CA04 (4–8 mice/group). (<b>H</b> and <b>I</b>) Total protein levels (H) and viral burdens (I) in BALF were measured on day 3 post-infection (6 mice/group). *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.