Figure 1.

Matrix metalloproteinase (MMP) 7 and syndecan-1 (Sdc1) promote neutrophil influx in response to acute Pseudomonas aeruginosa infection. Wild-type (WT), Mmp7^−/−, and Sdc1^−/− mice were intubated with 2 × 10⁹ colony-forming units of live P. aeruginosa, and bronchoalveolar lavage (BAL) was collected at the indicated times. (A) Total neutrophils (PMN) were quantified on stained cytospins (n = 4, mean ± SE; P < 0.01, WT relative to ^#Mmp7^−/− and *Sdc1^−/−). (B) Representative pictures at 9 and 24 hours after infection. (C) CXCL1 (KC) levels in BAL were determined by ELISA. *P < 0.01. (D) WT BAL was immunoprecipitated with control rat IgG (solid bars) or syndecan-1 ectodomain antibody 281-2 (open bars). KC levels remaining in BAL were determined by ELISA. *P < 0.01 compared with IgG control.