Antileukinate, a Hexapeptide Inhibitor of CXC-Chemokine Receptor, Suppresses Bleomycin-induced Acute Lung Injury in Mice

A hexapeptide, Ac-RRWWCR-NH 2 (Antileukinate), has been reported to be a potent inhibitor of CXC-chemokine receptor. However, the in vivo anti-inflammatory activity of this agent has not been tested except in a rabbit skin edema model. This study was undertaken to investigate the effect of subcutaneously administered Antileukinate on experimental bleomycin-induced acute lung injury in mice, in which CXC-chemokines have been reported to be involved. Lung injury was assessed on the basis of histopathology, the number of total cells, the percentage of neutrophils, and protein concentration in the bronchoalveolar lavage (BAL) fluid, and the wet lung weight at 7 days after intratracheal instillation of bleomycin. Histopathological studies revealed that treatment with Antileukinate markedly suppressed inflammatory cell infiltration and interstitial lung edema. The neutrophil counts in the BAL fluid were significantly decreased in the Antileukinate-treated group. The suppression of pulmonary edema was further confirmed by the reduction of wet lung weight and total protein concentration in the BAL fluid. These findings suggest that Antileukinate is able to inhibit acute lung injury by suppressing neutrophil mobilization induced by CXC-chemokines.