hMSCs decrease LPS-induced lung injury in immunocompetent mice. BALB/C mice were treated with LPS or PBS via oropharyngeal aspiration (OA) and four hours later 5 × 105 hMSCs and HLFs or PBS as controls, were delivered by OA. Lung injury was assessed 24 and 48 h later. (a) Representative images of hematoxylin and eosin staining of lung sections demonstrate reduced exudation and cellularity in hMSC treated lungs 48 h after LPS. (b) A lung injury index was quantified by threshold image analysis of whole lung sections and reported as fold change over control (PBS + PBS). (c) Pulmonary edema as measured by lung wet/dry weight ratio was significantly reduced in hMSC treated groups (n = 7 to 8 per group). (d) Total protein in BALF was also reduced in the hMSC treated groups (n = 4 to 6 per group). Data are presented as mean ± SEM. *P < 0.05 compared with LPS + PBS treated mice; † P < 0.05 compared with LPS + HLF treated group, and ‡ P < 0.0007 versus mice treated with PBS + PBS.