Figure 1.

C-X-C motif chemokine receptor (CXCR) 2–expressing myeloid-derived cell expansion in macrophage-depleted, bleomycin-treated mice. (A) CXCR2 expression, by in situ hybridization (ISH), in the bone marrow (brown stain, open arrowheads) of mice that underwent 33-day intraperitoneal bleomycin protocol with either PBS or clodronate (CL₂MDP) liposome treatment. Scale bar: 100 μm, magnification ×60. (B) CXCR2⁺ cells within the lung, analyzed by flow cytometry, (C) percentage gated on CD45⁺ cells. (D) CXCL1 protein expression, assessed by multiplex array in whole mouse lung. (E) ISH of lung histology for CXCR2 expression (brown, solid arrowheads). Scale bar: 100 μm, magnification ×60 (n = 12 per mouse group over course of three independent experiments). Results are plotted as the mean (±SEM). *P < 0.05. Bleo = bleomycin; FSC = forward scatter; KC = CXCL1; Veh = vehicle.