Figure 1.

Loss of myeloperoxidase (MPO) increases neutrophil transmigration in sterile vascular inflammation in vivo. Intravital microscopy was performed as described in “Materials and Methods.” Intrascrotal injection of tumor necrosis factor-α induced cremaster vascular inflammation, and neutrophils and platelets were labeled by infusion of Alexa Fluor 647-conjugated anti-Ly-6G and DyLight 488-conjugated anti-CD42c antibodies, respectively. (A) Representative images at various time points. The direction of blood flow is indicated by the arrows. Arrowheads highlight emigrated neutrophils. (B) The rolling influx of neutrophils (cells per minute). (C) The number of adherent neutrophils (cells per 5 min). (D) The number of transmigrated neutrophils (cells per 5 min). (E) The platelet signal (integrated median fluorescence intensities of anti-CD42c antibodies) over time was quantified and normalized to the number of adherent neutrophils and the vessel length. Data are shown as the mean ± SEM (n = 30 venules from 3 mice per group). ***P < 0.001 versus wild-type (WT) after Student’s t-test.