Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification

Ronan A. Murphy; Jade Pizzato; Leah Cuhbertson; Akshay Sabnis; Andrew M. Edwards; Laura M. Nolan; Thomas Vorup-Jensen; Gerald Larrouy-Maumus; Jane C. Davies

doi:10.1038/s44259-024-00022-x

Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification

Ronan A. Murphy, Jade Pizzato, Leah Cuhbertson, Akshay Sabnis, Andrew M. Edwards, Laura M. Nolan, Thomas Vorup-Jensen, Gerald Larrouy-Maumus, Jane C. Davies^*

^*Corresponding author for this work

Department of Biomedicine

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

Abstract

Antimicrobial peptides (AMPs) are key components of innate immunity across all domains of life. Natural and synthetic AMPs are receiving renewed attention in efforts to combat the antimicrobial resistance (AMR) crisis and the loss of antibiotic efficacy. The gram-negative pathogen Pseudomonas aeruginosa is one of the most concerning infecting bacteria in AMR, particularly in people with cystic fibrosis (CF) where respiratory infections are difficult to eradicate and associated with increased morbidity and mortality. Cationic AMPs exploit the negatively charged lipopolysaccharides (LPS) on P. aeruginosa to bind and disrupt bacterial membrane(s), causing lethal damage. P. aeruginosa modifies its LPS to evade AMP killing. Free-LPS is also a component of CF sputum and feeds pro-inflammatory cycles. Glatiramer acetate (GA) is a random peptide co-polymer—of glycine, lysine, alanine, tyrosine—used as a drug in treatment of multiple sclerosis (MS); we have previously shown GA to be an AMP which synergises with tobramycin against CF P. aeruginosa, functioning via bacterial membrane disruption. Here, we demonstrate GA’s direct binding and sequestration/neutralisation of P. aeruginosa LPS, in keeping with GA’s ability to disrupt the outer membrane. At CF-relevant LPS concentrations, however, membrane disruption by GA was not strongly inhibited. Furthermore, exposure to GA did not result in increased Lipid A modification of LPS or in increased gene expression of systems involved in AMP sensing and LPS modification. Therefore, despite the electrostatic targeting of LPS by GA as part of its activity, P. aeruginosa does not demonstrate LPS modification in its defence.

Original language	English
Article number	4
Journal	npj Antimicrobials and Resistance
Volume	2
Issue	4
Number of pages	15
ISSN	2731-8745
DOIs	https://doi.org/10.1038/s44259-024-00022-x
Publication status	Published - 20 Feb 2024

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Murphy, R. A., Pizzato, J., Cuhbertson, L., Sabnis, A., Edwards, A. M., Nolan, L. M., Vorup-Jensen, T., Larrouy-Maumus, G., & Davies, J. C. (2024). Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification. npj Antimicrobials and Resistance, 2(4), Article 4. https://doi.org/10.1038/s44259-024-00022-x

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title = "Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification",

abstract = "Antimicrobial peptides (AMPs) are key components of innate immunity across all domains of life. Natural and synthetic AMPs are receiving renewed attention in efforts to combat the antimicrobial resistance (AMR) crisis and the loss of antibiotic efficacy. The gram-negative pathogen Pseudomonas aeruginosa is one of the most concerning infecting bacteria in AMR, particularly in people with cystic fibrosis (CF) where respiratory infections are difficult to eradicate and associated with increased morbidity and mortality. Cationic AMPs exploit the negatively charged lipopolysaccharides (LPS) on P. aeruginosa to bind and disrupt bacterial membrane(s), causing lethal damage. P. aeruginosa modifies its LPS to evade AMP killing. Free-LPS is also a component of CF sputum and feeds pro-inflammatory cycles. Glatiramer acetate (GA) is a random peptide co-polymer—of glycine, lysine, alanine, tyrosine—used as a drug in treatment of multiple sclerosis (MS); we have previously shown GA to be an AMP which synergises with tobramycin against CF P. aeruginosa, functioning via bacterial membrane disruption. Here, we demonstrate GA{\textquoteright}s direct binding and sequestration/neutralisation of P. aeruginosa LPS, in keeping with GA{\textquoteright}s ability to disrupt the outer membrane. At CF-relevant LPS concentrations, however, membrane disruption by GA was not strongly inhibited. Furthermore, exposure to GA did not result in increased Lipid A modification of LPS or in increased gene expression of systems involved in AMP sensing and LPS modification. Therefore, despite the electrostatic targeting of LPS by GA as part of its activity, P. aeruginosa does not demonstrate LPS modification in its defence.",

keywords = "antimicrobial peptide, Pseudomonas, cystic fibrosis, antimicrobial resistance",

author = "Murphy, {Ronan A.} and Jade Pizzato and Leah Cuhbertson and Akshay Sabnis and Edwards, {Andrew M.} and Nolan, {Laura M.} and Thomas Vorup-Jensen and Gerald Larrouy-Maumus and Davies, {Jane C.}",

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Murphy, RA, Pizzato, J, Cuhbertson, L, Sabnis, A, Edwards, AM, Nolan, LM, Vorup-Jensen, T, Larrouy-Maumus, G & Davies, JC 2024, 'Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification', npj Antimicrobials and Resistance, vol. 2, no. 4, 4. https://doi.org/10.1038/s44259-024-00022-x

Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification. / Murphy, Ronan A.; Pizzato, Jade; Cuhbertson, Leah et al.
In: npj Antimicrobials and Resistance, Vol. 2, No. 4, 4, 20.02.2024.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

TY - JOUR

T1 - Antimicrobial peptide glatiramer acetate targets Pseudomonas aeruginosa lipopolysaccharides to breach membranes without altering lipopolysaccharide modification

AU - Murphy, Ronan A.

AU - Pizzato, Jade

AU - Cuhbertson, Leah

AU - Sabnis, Akshay

AU - Edwards, Andrew M.

AU - Nolan, Laura M.

AU - Vorup-Jensen, Thomas

AU - Larrouy-Maumus, Gerald

AU - Davies, Jane C.

PY - 2024/2/20

Y1 - 2024/2/20

N2 - Antimicrobial peptides (AMPs) are key components of innate immunity across all domains of life. Natural and synthetic AMPs are receiving renewed attention in efforts to combat the antimicrobial resistance (AMR) crisis and the loss of antibiotic efficacy. The gram-negative pathogen Pseudomonas aeruginosa is one of the most concerning infecting bacteria in AMR, particularly in people with cystic fibrosis (CF) where respiratory infections are difficult to eradicate and associated with increased morbidity and mortality. Cationic AMPs exploit the negatively charged lipopolysaccharides (LPS) on P. aeruginosa to bind and disrupt bacterial membrane(s), causing lethal damage. P. aeruginosa modifies its LPS to evade AMP killing. Free-LPS is also a component of CF sputum and feeds pro-inflammatory cycles. Glatiramer acetate (GA) is a random peptide co-polymer—of glycine, lysine, alanine, tyrosine—used as a drug in treatment of multiple sclerosis (MS); we have previously shown GA to be an AMP which synergises with tobramycin against CF P. aeruginosa, functioning via bacterial membrane disruption. Here, we demonstrate GA’s direct binding and sequestration/neutralisation of P. aeruginosa LPS, in keeping with GA’s ability to disrupt the outer membrane. At CF-relevant LPS concentrations, however, membrane disruption by GA was not strongly inhibited. Furthermore, exposure to GA did not result in increased Lipid A modification of LPS or in increased gene expression of systems involved in AMP sensing and LPS modification. Therefore, despite the electrostatic targeting of LPS by GA as part of its activity, P. aeruginosa does not demonstrate LPS modification in its defence.

AB - Antimicrobial peptides (AMPs) are key components of innate immunity across all domains of life. Natural and synthetic AMPs are receiving renewed attention in efforts to combat the antimicrobial resistance (AMR) crisis and the loss of antibiotic efficacy. The gram-negative pathogen Pseudomonas aeruginosa is one of the most concerning infecting bacteria in AMR, particularly in people with cystic fibrosis (CF) where respiratory infections are difficult to eradicate and associated with increased morbidity and mortality. Cationic AMPs exploit the negatively charged lipopolysaccharides (LPS) on P. aeruginosa to bind and disrupt bacterial membrane(s), causing lethal damage. P. aeruginosa modifies its LPS to evade AMP killing. Free-LPS is also a component of CF sputum and feeds pro-inflammatory cycles. Glatiramer acetate (GA) is a random peptide co-polymer—of glycine, lysine, alanine, tyrosine—used as a drug in treatment of multiple sclerosis (MS); we have previously shown GA to be an AMP which synergises with tobramycin against CF P. aeruginosa, functioning via bacterial membrane disruption. Here, we demonstrate GA’s direct binding and sequestration/neutralisation of P. aeruginosa LPS, in keeping with GA’s ability to disrupt the outer membrane. At CF-relevant LPS concentrations, however, membrane disruption by GA was not strongly inhibited. Furthermore, exposure to GA did not result in increased Lipid A modification of LPS or in increased gene expression of systems involved in AMP sensing and LPS modification. Therefore, despite the electrostatic targeting of LPS by GA as part of its activity, P. aeruginosa does not demonstrate LPS modification in its defence.

KW - antimicrobial peptide

KW - Pseudomonas

KW - cystic fibrosis

KW - antimicrobial resistance

U2 - 10.1038/s44259-024-00022-x

DO - 10.1038/s44259-024-00022-x

M3 - Journal article

C2 - 39843948

SN - 2731-8745

VL - 2

JO - npj Antimicrobials and Resistance

JF - npj Antimicrobials and Resistance

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ER -