OMENTAL HIGH ENDOTHELIAL VENULES AS CRITICAL NEUTROPHIL EXIT SITE IN PERITONITIS

Neutrophil recruitment from the blood into the peritoneal cavity is critical in acute peritonitis but precise mechanisms of extravasation are largely unknown. In this study we identified the greater omentum as major exit site in early phases of mono- and polymicrobial peritoneal inflammation. A novel intravital microscopy technique was developed to image the inflamed omentum showing that high endothelial venules, known for their role in constitutive lymphocyte homing, are the preferred vascular bed for neutrophil recruitment with a unique requirement of adhesion receptors. Specific inhibition of the omental pathway in mice leads to delayed neutrophil deployment in the peritoneum, increased bacterial load, and aggravates septic progression of bacterial peritonitis. Support or Funding Information - German Research Foundation grant to LS (CRC1009/A02, So285/9-1, EXE1003)- German Research Foundation grant to KB (BU 3247/1)- Cells-in-Motion Cluster of Excellence Flexible Funds grant (FF-2014-07) to JS and KB- ...