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

Dahl, Sara LU ; Anders, Emma LU ; Gidlöf, Olof LU ; Svensson, Daniel LU and Nilsson, Bengt Olof LU (2018) In Peptides 109. p.39-45
Abstract

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... (More)

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.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cathelicidin, Cell viability, Extracellular trap, Host defense peptide (HDP), Innate immunity, Mast cells
in
Peptides
volume
109
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85054627565
ISSN
0196-9781
DOI
10.1016/j.peptides.2018.10.001
language
English
LU publication?
yes
id
9cb02667-7ea3-45d6-96ac-2e6bca3ba609
date added to LUP
2018-11-09 12:12:07
date last changed
2019-05-07 15:54:36
@article{9cb02667-7ea3-45d6-96ac-2e6bca3ba609,
  abstract     = {<p>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.</p>},
  author       = {Dahl, Sara and Anders, Emma and Gidlöf, Olof and Svensson, Daniel and Nilsson, Bengt Olof},
  issn         = {0196-9781},
  keyword      = {Cathelicidin,Cell viability,Extracellular trap,Host defense peptide (HDP),Innate immunity,Mast cells},
  language     = {eng},
  pages        = {39--45},
  publisher    = {Elsevier},
  series       = {Peptides},
  title        = {The host defense peptide LL-37 triggers release of nucleic acids from human mast cells},
  url          = {http://dx.doi.org/10.1016/j.peptides.2018.10.001},
  volume       = {109},
  year         = {2018},
}