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The human antimicrobial peptide LL-37 transfers extracellular DNA plasmid to the nuclear compartment of mammalian cells via lipid rafts and proteoglycan-dependent endocytosis

Sandgren, Staffan LU ; Wittrup, Anders LU ; Cheng, Fang LU ; Jönsson, Mats LU ; Eklund, Erik LU ; Busch, S and Belting, Mattias LU (2004) In Journal of Biological Chemistry 279(17). p.17951-17956
Abstract
Antimicrobial peptides, such as LL-37, are found both in nonvertebrates and vertebrates, where they represent important components of innate immunity. Bacterial infections at epithelial surfaces are associated with substantial induction of LL-37 expression, which allows efficient lysis of the invading microbes. Peptide-mediated lysis results in the release of bacterial nucleic acids with potential pathobiological activity in the host. Here, we demonstrate that LL-37 targets extracellular DNA plasmid to the nuclear compartment of mammalian cells, where it is expressed. DNA transfer occurred at physiological LL-37 concentrations that killed bacterial cells, whereas virtually no cytotoxic or growth-inhibitory effects were observed in... (More)
Antimicrobial peptides, such as LL-37, are found both in nonvertebrates and vertebrates, where they represent important components of innate immunity. Bacterial infections at epithelial surfaces are associated with substantial induction of LL-37 expression, which allows efficient lysis of the invading microbes. Peptide-mediated lysis results in the release of bacterial nucleic acids with potential pathobiological activity in the host. Here, we demonstrate that LL-37 targets extracellular DNA plasmid to the nuclear compartment of mammalian cells, where it is expressed. DNA transfer occurred at physiological LL-37 concentrations that killed bacterial cells, whereas virtually no cytotoxic or growth-inhibitory effects were observed in mammalian cells. Furthermore, LL-37 protected DNA from serum nuclease degradation. LL-37.DNA complex uptake was a saturable time- and temperature-dependent process and was sensitive to cholesterol-depleting agents that are known to disrupt lipid rafts and caveolae, as shown by flow cytometry. Confocal fluorescence microscopy studies showed localization of internalized DNA to compartments stained by cholera toxin B, a marker of lipid rafts, but failed to demonstrate any co-localization of internalized DNA with caveolin-positive endocytotic vesicles. Moreover, LL-37-mediated plasmid uptake and reporter gene expression were strictly dependent on cell surface proteoglycans. We conclude that the human antimicrobial peptide LL-37 binds to, protects, and efficiently targets DNA plasmid to the nuclei of mammalian cells through caveolae-independent membrane raft endocytosis and cell surface proteoglycans. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
279
issue
17
pages
17951 - 17956
publisher
ASBMB
external identifiers
  • wos:000220870400129
  • scopus:2342520028
ISSN
1083-351X
DOI
10.1074/jbc.M311440200
language
English
LU publication?
yes
id
89fe9b70-6078-4d35-9533-a15717e32868 (old id 281243)
date added to LUP
2007-10-31 12:12:40
date last changed
2017-12-10 03:42:28
@article{89fe9b70-6078-4d35-9533-a15717e32868,
  abstract     = {Antimicrobial peptides, such as LL-37, are found both in nonvertebrates and vertebrates, where they represent important components of innate immunity. Bacterial infections at epithelial surfaces are associated with substantial induction of LL-37 expression, which allows efficient lysis of the invading microbes. Peptide-mediated lysis results in the release of bacterial nucleic acids with potential pathobiological activity in the host. Here, we demonstrate that LL-37 targets extracellular DNA plasmid to the nuclear compartment of mammalian cells, where it is expressed. DNA transfer occurred at physiological LL-37 concentrations that killed bacterial cells, whereas virtually no cytotoxic or growth-inhibitory effects were observed in mammalian cells. Furthermore, LL-37 protected DNA from serum nuclease degradation. LL-37.DNA complex uptake was a saturable time- and temperature-dependent process and was sensitive to cholesterol-depleting agents that are known to disrupt lipid rafts and caveolae, as shown by flow cytometry. Confocal fluorescence microscopy studies showed localization of internalized DNA to compartments stained by cholera toxin B, a marker of lipid rafts, but failed to demonstrate any co-localization of internalized DNA with caveolin-positive endocytotic vesicles. Moreover, LL-37-mediated plasmid uptake and reporter gene expression were strictly dependent on cell surface proteoglycans. We conclude that the human antimicrobial peptide LL-37 binds to, protects, and efficiently targets DNA plasmid to the nuclei of mammalian cells through caveolae-independent membrane raft endocytosis and cell surface proteoglycans.},
  author       = {Sandgren, Staffan and Wittrup, Anders and Cheng, Fang and Jönsson, Mats and Eklund, Erik and Busch, S and Belting, Mattias},
  issn         = {1083-351X},
  language     = {eng},
  number       = {17},
  pages        = {17951--17956},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {The human antimicrobial peptide LL-37 transfers extracellular DNA plasmid to the nuclear compartment of mammalian cells via lipid rafts and proteoglycan-dependent endocytosis},
  url          = {http://dx.doi.org/10.1074/jbc.M311440200},
  volume       = {279},
  year         = {2004},
}