Figure 4. Administration of WT PRs enriched in TSP-1 to Thbs1^–/– mice after Pseudomonas aeruginosa infection reduce lung bacterial burden, airspace neutrophil recruitment, and lung NE activity when compared with Thbs1^–/– PR-treated mice.

(A) Platelet releasates (PRs) from WT mice and Thbs1^–/– mice were analyzed for TSP-1 isoforms by Western blot using an anti–TSP-1 antibody. Purified human TSP-1 was used as positive control. (B–M) Thbs1^–/– mice (KO) were inoculated with P. aeruginosa strain PA14 at 10⁶ inoculum, and mice were subsequently administered either WT PRs or Thbs1^–/– PRs by i.p. injection. Outcome measurements (B) lung CFU/ml, (C) total bronchoalveolar lavage (BAL) cells counts/ml, (D) total BAL PMN counts/ml, (E) lung myeloperoxidase (MPO) activity, and (F) lung neutrophil elastase (NE) activity were obtained 20 hours after infection. (G) G-CSF, (H) GM-CSF, (I) keratinocyte chemoattractant (KC), (J) IL-6, (K) IL-10, (L) IL-17A, and (M) TNF-α concentrations were measured in lung tissue homogenates. Each data point represents an individual mouse, n = 7 mice per group. Lines indicate the median. *P < 0.05, **P < 0.01 by 2-tailed Mann-Whitney U test.