CD11c+ Cells Are Required to Prevent Progression from Local Acute Lung Injury to Multiple Organ Failure and Death

To investigate the role of CD11c+ cells in endotoxin-induced acute lung injury, wild-type or CD11c-diphtheria toxin receptor transgenic mice were treated with intraperitoneal diphtheria toxin (5 ng/g b.wt.) in the presence or absence of intratracheal lipopolysaccharide (51 μg). Lipopolysaccharide treatment resulted in 100% mortality in CD11c-depleted animals but not in control animals. Analysis of local lung tissue revealed no differences in acute lung injury severity; however, analysis of distal tissues revealed severe damage and necrosis to multiple organs (liver, spleen, and kidneys) in CD11c-diphtheria toxin receptor mice but not in wild-type mice. In addition, dramatic increases in systemic levels of liver enzymes (alanine aminotransferase, 657 U/L, aspartate aminotransferase, 1401 U/L), blood urea (53 mg/dl), and 8-iso-prostaglandin F2α, a marker of oxidative stress (350 pg/ml), were observed. These data demonstrate that CD11c+ cells play a critical role in protecting the organs from systemic injury caused by a pulmonary endotoxin challenge.