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The human CXC chemokine granulocyte chemotactic protein 2 (GCP-2)/CXCL6 possesses membrane-disrupting properties and is antibacterial

Linge, Helena M LU ; Collin, Mattias LU ; Nordenfelt, Pontus LU ; Mörgelin, Matthias LU ; Malmsten, Martin and Egesten, Arne LU (2008) In Antimicrobial Agents and Chemotherapy 52(7). p.2599-2607
Abstract

Granulocyte chemotactic protein 2 (GCP-2)/CXCL6 is a CXC chemokine expressed by macrophages and epithelial and mesenchymal cells during inflammation. Through binding and activation of its receptors (CXCR1 and CXCR2), it exerts neutrophil-activating and angiogenic activities. Here we show that GCP-2/CXCL6 itself is antibacterial. Antibacterial activity against gram-positive and gram-negative pathogenic bacteria of relevance to mucosal infections was seen at submicromolar concentrations (minimal bactericidal concentration at which 50% of strains tested were killed, 0.063 +/- 0.01 to 0.37 +/- 0.03 muM). In killed bacteria, GCP-2/CXCL6 associated with bacterial surfaces, which showed membrane disruption and leakage. A structural prediction... (More)

Granulocyte chemotactic protein 2 (GCP-2)/CXCL6 is a CXC chemokine expressed by macrophages and epithelial and mesenchymal cells during inflammation. Through binding and activation of its receptors (CXCR1 and CXCR2), it exerts neutrophil-activating and angiogenic activities. Here we show that GCP-2/CXCL6 itself is antibacterial. Antibacterial activity against gram-positive and gram-negative pathogenic bacteria of relevance to mucosal infections was seen at submicromolar concentrations (minimal bactericidal concentration at which 50% of strains tested were killed, 0.063 +/- 0.01 to 0.37 +/- 0.03 muM). In killed bacteria, GCP-2/CXCL6 associated with bacterial surfaces, which showed membrane disruption and leakage. A structural prediction indicated the presence of three antiparallel NH(2)-terminal beta-sheets and a short amphipathic COOH-terminal alpha-helix; the latter feature is typical of antimicrobial peptides. However, when the synthetic derivatives corresponding to the NH(2)-terminal (50 amino acids) and COOH-terminal (19 amino acids, corresponding to the putative alpha-helix) regions were compared, higher antibacterial activity was observed for the NH(2)-terminus-derived peptide, indicating that the holopeptide is necessary for full antibacterial activity. An artificial model of bacterial membranes confirmed these findings. The helical content of GCP-2/CXCL6 in the presence or absence of lipopolysaccharide or negatively charged membranes was studied by circular dichroism. As with many antibacterial peptides, membrane disruption by GCP-2/CXCL6 was dose-dependently reduced in the presence of NaCl, which, we here demonstrate, inhibited the binding of the peptide to the bacterial surface. Compared with CXC chemokines ENA-78/CXCL5 and NAP-2/CXCL7, GCP-2/CXCL6 showed a 90-fold-higher antibacterial activity. Taken together, GCP/CXCL6, in addition to its chemotactic and angiogenic properties, is likely to contribute to direct antibacterial activity during localized infection.

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keywords
Amino Acid Sequence, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Blood Bactericidal Activity, Cell Membrane, Chemokine CXCL5, Chemokine CXCL6, Escherichia coli, Gram-Negative Bacteria, Gram-Positive Bacteria, Humans, In Vitro Techniques, Liposomes, Microbial Sensitivity Tests, Models, Molecular, Protein Structure, Secondary, Recombinant Proteins, Staphylococcus aureus, Streptococcus pyogenes, beta-Thromboglobulin, Journal Article, Research Support, Non-U.S. Gov't
in
Antimicrobial Agents and Chemotherapy
volume
52
issue
7
pages
9 pages
publisher
American Society for Microbiology
external identifiers
  • wos:000257183400042
  • pmid:18443119
  • scopus:46249102418
ISSN
1098-6596
DOI
10.1128/AAC.00028-08
language
English
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yes
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1ea89df9-6551-48ce-ab60-2620d6211255 (old id 1154702)
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http://www.ncbi.nlm.nih.gov/pubmed/18443119?dopt=Abstract
date added to LUP
2008-06-04 15:02:20
date last changed
2017-01-02 14:49:46
@article{1ea89df9-6551-48ce-ab60-2620d6211255,
  abstract     = {<p>Granulocyte chemotactic protein 2 (GCP-2)/CXCL6 is a CXC chemokine expressed by macrophages and epithelial and mesenchymal cells during inflammation. Through binding and activation of its receptors (CXCR1 and CXCR2), it exerts neutrophil-activating and angiogenic activities. Here we show that GCP-2/CXCL6 itself is antibacterial. Antibacterial activity against gram-positive and gram-negative pathogenic bacteria of relevance to mucosal infections was seen at submicromolar concentrations (minimal bactericidal concentration at which 50% of strains tested were killed, 0.063 +/- 0.01 to 0.37 +/- 0.03 muM). In killed bacteria, GCP-2/CXCL6 associated with bacterial surfaces, which showed membrane disruption and leakage. A structural prediction indicated the presence of three antiparallel NH(2)-terminal beta-sheets and a short amphipathic COOH-terminal alpha-helix; the latter feature is typical of antimicrobial peptides. However, when the synthetic derivatives corresponding to the NH(2)-terminal (50 amino acids) and COOH-terminal (19 amino acids, corresponding to the putative alpha-helix) regions were compared, higher antibacterial activity was observed for the NH(2)-terminus-derived peptide, indicating that the holopeptide is necessary for full antibacterial activity. An artificial model of bacterial membranes confirmed these findings. The helical content of GCP-2/CXCL6 in the presence or absence of lipopolysaccharide or negatively charged membranes was studied by circular dichroism. As with many antibacterial peptides, membrane disruption by GCP-2/CXCL6 was dose-dependently reduced in the presence of NaCl, which, we here demonstrate, inhibited the binding of the peptide to the bacterial surface. Compared with CXC chemokines ENA-78/CXCL5 and NAP-2/CXCL7, GCP-2/CXCL6 showed a 90-fold-higher antibacterial activity. Taken together, GCP/CXCL6, in addition to its chemotactic and angiogenic properties, is likely to contribute to direct antibacterial activity during localized infection.</p>},
  author       = {Linge, Helena M and Collin, Mattias and Nordenfelt, Pontus and Mörgelin, Matthias and Malmsten, Martin and Egesten, Arne},
  issn         = {1098-6596},
  keyword      = {Amino Acid Sequence,Anti-Bacterial Agents,Antimicrobial Cationic Peptides,Blood Bactericidal Activity,Cell Membrane,Chemokine CXCL5,Chemokine CXCL6,Escherichia coli,Gram-Negative Bacteria,Gram-Positive Bacteria,Humans,In Vitro Techniques,Liposomes,Microbial Sensitivity Tests,Models, Molecular,Protein Structure, Secondary,Recombinant Proteins,Staphylococcus aureus,Streptococcus pyogenes,beta-Thromboglobulin,Journal Article,Research Support, Non-U.S. Gov't},
  language     = {eng},
  number       = {7},
  pages        = {2599--2607},
  publisher    = {American Society for Microbiology},
  series       = {Antimicrobial Agents and Chemotherapy},
  title        = {The human CXC chemokine granulocyte chemotactic protein 2 (GCP-2)/CXCL6 possesses membrane-disrupting properties and is antibacterial},
  url          = {http://dx.doi.org/10.1128/AAC.00028-08},
  volume       = {52},
  year         = {2008},
}