Role of Protein Synthesis and CD 11 /CD 18 Adhesion Complex in Neutrophil Emigration into the Lung

The mechanism of neutrophil (PMN) emigration into the lung may he stimulus-dependent. This study examined PMN emigration in the lung induced by intratracheal instillation of lipopolysaccharide (LPS), Streptococcus pneumoniae (S. pneu) organisms, supernatant from S. pneu incubated with alveolar macrophages (AMФ), Escherichia coli (E. coli) organisms, or phorhol myristate acetate (PMA). Rabbits were pre-treated with either the CD18 monoclonal antibody (MAb) 60.3, the protein synthesis inhibitor cycloheximide (Cx), or, in one case, both. Animals were then given one of the above stimuli to elicit PMN emigration. Four hours after the stimulus was instilled, animals were killed and total and differential cell counts were performed on bronchoal-veolar lavage (BAL) fluid. PMN emigration in response to PMA was virtually abolished by MAb 60.3, but was not significantly inhibited by Cx. Emigration induced by LPS was inhibited by 80% by either MAb 60.3 or Cx, and greater than 94% when MAb 60.3 and Cx were given simul...