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Olof Gidlöf

Research project participant

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The host defense peptide LL-37 triggers release of nucleic acids from human mast cells

Author

  • Sara Dahl
  • Emma Anders
  • Olof Gidlöf
  • Daniel Svensson
  • Bengt Olof Nilsson

Summary, in English

The human host defense peptide LL-37 possesses antimicrobial activity but also affects host cell function and viability. Mast cells are involved in innate immunity but no data have been presented on effects of LL-37 on human mast cell viability and export of nucleic acids. Here, we demonstrated by immunofluorescence microscopy that synthesized LL-37 was internalized by human LAD2 mast cells and detected both in cytoplasm and nucleus. Treatment with high (4 and 10 μM) but not low (1 μM) concentrations of LL-37 for 4 h reduced cell viability assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Stimulation with 10 μM LL-37 for 4 h enhanced export of nucleic acids, total protein and lactate dehydrogenase (LDH), suggesting that both nuclear and plasma membranes are permeabilized by LL-37. Although LL-37 triggered release of nucleic acids, no extracellular trap-like structures were observed by laser scanning confocal microscopy of cells incubated with the plasma membrane impermeable nucleic acid fluorophore SYTOX-Green, indicating that LL-37 promotes export of nucleic acids but not formation of extracellular traps. On the other hand, phorbol-12-myristate-13-acetate (PMA), which is a well-known inducer of extracellular traps, stimulated export of nucleic acids and also formation of extracellular trap-like structures. However, PMA had no effect on export of either total protein or LDH. Hence, LL-37 and PMA seem to stimulate export of nucleic acids from LAD2 mast cells through different pathways. In conclusion, we demonstrate that LL-37 triggers release of nucleic acids from human mast cells but not the formation of extracellular trap-like structures.

Department/s

  • Vascular Physiology
  • Molecular Cardiology

Publishing year

2018

Language

English

Pages

39-45

Publication/Series

Peptides

Volume

109

Document type

Journal article

Publisher

Elsevier

Topic

  • Cell and Molecular Biology
  • Immunology in the medical area

Keywords

  • Cathelicidin
  • Cell viability
  • Extracellular trap
  • Host defense peptide (HDP)
  • Innate immunity
  • Mast cells

Status

Published

Research group

  • Vascular Physiology
  • Molecular Cardiology

ISBN/ISSN/Other

  • ISSN: 0196-9781