Degradation of NETs by rhDNase in vitro. (A) PMN were isolated from bone marrow of naive mice and stimulated with 50 nM PMA. Supernatants were incubated with 0, 0.02, 0.2, 2.0 and 20.0 µg/ml rhDNase. An rhDNase concentration of 2 µg/ml resolves 140 µg/ml of NETs completely. n.d. = not detected. *P < 0.05, ***P < 0.001. (B) Immunofluorescence staining of NETs. The image of unstimulated PMN shows the nuclear localization of DNA (blue fluorescence) and the granular pattern of MPO (green fluorescence; top left). After stimulation morphological changes during NETs formation could be determined with loss of nuclear lobules and granular integrity of MPO (bottom left). Exposure of fixed NETs with 2 µg/ml (top right) and 20 µg/ml (bottom right) rhDNase resulted in the disintegration of NETs with loss of DNA structures. CLP, cecal ligation and puncture; DNase, desoxyribonuclease; MPO, myeloperoxidase; NETs, neutrophil extracellular traps; PMN, neutrophils; rh, recombinant human.