Bio-impedance measurement allows displaying the early stages of neutrophil extracellular traps

Authors

  • Caren Linnemann Siegfried Weller Institute for Trauma Research, BG Unfallklinik Tuebingen, Eberhard Karls Universität Tuebingen, Tuebingen, Germany
  • Sascha Venturelli Institute of Physiology, Department of Vegetative and Clinical Physiology, University Hospital Tuebingen, Tuebingen, Germany; Institute of Nutritional Sciences, Department of Nutritional Biochemistry, University of Hohenheim, Stuttgart, Germany
  • Franziska Konrad Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tuebingen, Tuebingen, Germany
  • Andreas K. Nussler Siegfried Weller Institute for Trauma Research, BG Unfallklinik Tuebingen, Eberhard Karls Universität Tuebingen, Tuebingen, Germany
  • Sabrina Ehnert Siegfried Weller Institute for Trauma Research, BG Unfallklinik Tuebingen, Eberhard Karls Universität Tuebingen, Schnarrenbergstr. 95, 72076 Tuebingen, Germany; Tel.: +497071 606 1065, Fax.: +49 70 71 606 1978; E-mail: sabrina.ehnert@gmail.com https://orcid.org/0000-0003-4347-1702

DOI:

https://doi.org/10.17179/excli2020-2868

Keywords:

bio-impedance, neutrophils, neutrophil extracellular traps, Sytox Green Assay, xCelligence, immune cell activation

Abstract

Neutrophils are the most abundant immune cells in the blood. Besides common immune defense mechanisms, releasing their DNA covered with antimicrobial proteases and histones represent another strong defense mechanism: neutrophil extracellular traps. In vitro the two most common inducers of these, so called, NETs are calcium ionophores (CI) and PMA (Phorbol 12-myristate 13-acetate). Following stimulation monitoring of NET release is necessary. For now, the methods of choice are quantification of free DNA by fluorescent dyes or analysis of immunofluorescence images. As a new method we tested bio-impedance monitoring of neutrophils after stimulation with the two inducers PMA and CI in gold-electrode coated plates. Bio-impedance (cell index) was measured over time. Results were compared to the monitoring of NETs by the fluorescent DNA-binding dye Sytox Green and immunofluorescence analysis. Cell index peaked about 25 min faster following CI stimulation than following PMA stimulation. The activation in Sytox Green Assay was significantly later detectable for PMA (+ approx. 90 min) but not for CI stimulation. The earlier and faster activation by CI was also confirmed by immunofluorescence staining. Our data suggest that bio-impedance measurement allows an easy online tracking of early neutrophil activation. This offers new opportunities to monitor early phases and stimuli-dependent dynamics of NETosis.

Published

2020-11-05

How to Cite

Linnemann, C., Venturelli, S. ., Konrad, F., Nussler, A. K., & Ehnert, S. (2020). Bio-impedance measurement allows displaying the early stages of neutrophil extracellular traps. EXCLI Journal, 19, 1481–1495. https://doi.org/10.17179/excli2020-2868

Issue

Section

Original articles

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