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Imaging the antimicrobial mechanism(s) of cathelicidin-2

Host defence peptides (HDPs) have the potential to become alternatives to conventional antibiotics in human and veterinary medicine. The HDP chicken cathelicidin-2 (CATH-2) has immunomodulatory and direct killing activities at micromolar concentrations. In this study the mechanism of action of CATH-...

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Autores principales: Schneider, Viktoria A. F., Coorens, Maarten, Ordonez, Soledad R., Tjeerdsma-van Bokhoven, Johanna L. M., Posthuma, George, van Dijk, Albert, Haagsman, Henk P., Veldhuizen, Edwin J. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5021996/
https://www.ncbi.nlm.nih.gov/pubmed/27624595
http://dx.doi.org/10.1038/srep32948
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author Schneider, Viktoria A. F.
Coorens, Maarten
Ordonez, Soledad R.
Tjeerdsma-van Bokhoven, Johanna L. M.
Posthuma, George
van Dijk, Albert
Haagsman, Henk P.
Veldhuizen, Edwin J. A.
author_facet Schneider, Viktoria A. F.
Coorens, Maarten
Ordonez, Soledad R.
Tjeerdsma-van Bokhoven, Johanna L. M.
Posthuma, George
van Dijk, Albert
Haagsman, Henk P.
Veldhuizen, Edwin J. A.
author_sort Schneider, Viktoria A. F.
collection PubMed
description Host defence peptides (HDPs) have the potential to become alternatives to conventional antibiotics in human and veterinary medicine. The HDP chicken cathelicidin-2 (CATH-2) has immunomodulatory and direct killing activities at micromolar concentrations. In this study the mechanism of action of CATH-2 against Escherichia coli (E. coli) was investigated in great detail using a unique combination of imaging and biophysical techniques. Live-imaging with confocal fluorescence microscopy demonstrated that FITC-labelled CATH-2 mainly localized at the membrane of E. coli. Upon binding, the bacterial membrane was readily permeabilized as was shown by propidium iodide influx into the cell. Concentration- and time-dependent effects of the peptide on E. coli cells were examined by transmission electron microscopy (TEM). CATH-2 treatment was found to induce dose-dependent morphological changes in E. coli. At sub-minimal inhibitory concentrations (sub-MIC), intracellular granulation, enhanced vesicle release and wrinkled membranes were observed, while membrane breakage and cell lysis occurred at MIC values. These effects were visible within 1–5 minute of peptide exposure. Immuno-gold TEM showed CATH-2 binding to bacterial membranes. At sub-MIC values the peptide rapidly localized intracellularly without visible membrane permeabilization. It is concluded that CATH-2 has detrimental effects on E. coli at concentrations that do not immediately kill the bacteria.
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spelling pubmed-50219962016-09-20 Imaging the antimicrobial mechanism(s) of cathelicidin-2 Schneider, Viktoria A. F. Coorens, Maarten Ordonez, Soledad R. Tjeerdsma-van Bokhoven, Johanna L. M. Posthuma, George van Dijk, Albert Haagsman, Henk P. Veldhuizen, Edwin J. A. Sci Rep Article Host defence peptides (HDPs) have the potential to become alternatives to conventional antibiotics in human and veterinary medicine. The HDP chicken cathelicidin-2 (CATH-2) has immunomodulatory and direct killing activities at micromolar concentrations. In this study the mechanism of action of CATH-2 against Escherichia coli (E. coli) was investigated in great detail using a unique combination of imaging and biophysical techniques. Live-imaging with confocal fluorescence microscopy demonstrated that FITC-labelled CATH-2 mainly localized at the membrane of E. coli. Upon binding, the bacterial membrane was readily permeabilized as was shown by propidium iodide influx into the cell. Concentration- and time-dependent effects of the peptide on E. coli cells were examined by transmission electron microscopy (TEM). CATH-2 treatment was found to induce dose-dependent morphological changes in E. coli. At sub-minimal inhibitory concentrations (sub-MIC), intracellular granulation, enhanced vesicle release and wrinkled membranes were observed, while membrane breakage and cell lysis occurred at MIC values. These effects were visible within 1–5 minute of peptide exposure. Immuno-gold TEM showed CATH-2 binding to bacterial membranes. At sub-MIC values the peptide rapidly localized intracellularly without visible membrane permeabilization. It is concluded that CATH-2 has detrimental effects on E. coli at concentrations that do not immediately kill the bacteria. Nature Publishing Group 2016-09-14 /pmc/articles/PMC5021996/ /pubmed/27624595 http://dx.doi.org/10.1038/srep32948 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Schneider, Viktoria A. F.
Coorens, Maarten
Ordonez, Soledad R.
Tjeerdsma-van Bokhoven, Johanna L. M.
Posthuma, George
van Dijk, Albert
Haagsman, Henk P.
Veldhuizen, Edwin J. A.
Imaging the antimicrobial mechanism(s) of cathelicidin-2
title Imaging the antimicrobial mechanism(s) of cathelicidin-2
title_full Imaging the antimicrobial mechanism(s) of cathelicidin-2
title_fullStr Imaging the antimicrobial mechanism(s) of cathelicidin-2
title_full_unstemmed Imaging the antimicrobial mechanism(s) of cathelicidin-2
title_short Imaging the antimicrobial mechanism(s) of cathelicidin-2
title_sort imaging the antimicrobial mechanism(s) of cathelicidin-2
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5021996/
https://www.ncbi.nlm.nih.gov/pubmed/27624595
http://dx.doi.org/10.1038/srep32948
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