ANTIINTERCELLULAR ADHESION MOLECULE1 ANTIBODY AND INTERCELLULAR ADHESION MOLECULE1 GENE DEFICIENCY DO NOT PREVENT PULMONARY NEUTROPHIL RECRUITMENT IN POLYMICROBIAL SEPSIS

The intercellular adhesion molecule (ICAM)-1 is expressed constitutively in normal lungs and increased in pulmonary inflammation. Whether increased ICAM-1 expression in the lung contributes to neutrophil sequestration during lung inflammation in sepsis is unclear. We tested this hypothesis in mice after systemic sepsis from cecal ligation and puncture (CLP). ICAM-1 expression in mouse CLP lung tissue was found to increase with time. The time course of lung ICAM-1 up-regulation correlated with increases in lung myeloperoxidase (MPO) activity and neutrophil sequestration by light microscopy. The monoclonal IgG2b rat anti-mouse antibody, an anti-ICAM-1 antibody (YN1/1.7), administered intravenously at doses of 3, 10, or 30 mg/kg, however, did not decrease the lung MPO levels compared with nonimmune rat IgG. In support of these findings, lung MPO content in ICAM-1 -deficient mice that underwent CLP was significantly higher than similarly treated ICAM-1 -sufficient mice. Our results suggest that neutrophil sequestration in the mouse lung after CLP is not dependent on ICAM-1.