E-Thesis 268 views 244 downloads
Targeted amplification of the oxidative burst in neutrophils as a bactericidal strategy against uropathogenic Escherichia coli / LOUIE BARNES
Swansea University Author: LOUIE BARNES
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Copyright: The Author, Louie Arron Barnes, 2025. Licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) License. Third party content is excluded for use under the license terms.
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Abstract
Urinary tract infections (UTIs), commonly caused by the Gram-negative bacteria Escherichia. coli, affect 50% of women and 12% of men in their lifetimes and represent an enormous burden on healthcare providers. UTIs have a high rate of recurrence and a low rate of resolution without antibiotic interv...
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Swansea, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Chick, Heather ; Wilkinson, Tom |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69857 |
| Abstract: |
Urinary tract infections (UTIs), commonly caused by the Gram-negative bacteria Escherichia. coli, affect 50% of women and 12% of men in their lifetimes and represent an enormous burden on healthcare providers. UTIs have a high rate of recurrence and a low rate of resolution without antibiotic intervention, making them a driving force in the rise of antimicrobial resistance (AMR). Alternative therapies such as immunomodulation could aid in reduction of antibiotic prescription and AMR. Small molecule compounds RE-04-001 and RE-04-006 selectively target Formyl peptide receptor 1 (FPR1) in neutrophils, the most abundant innate immune cells in UTIs, resulting in the generation of toxic reactive oxygen species via the oxidative burst. This research aimed to characterize interactions between FPR1-stimulated neutrophils and Uropathogenic E. coli (UPEC). Neutrophils isolated from whole blood were co-cultured with UPEC strain CFT-073 or laboratory strain K12 and co-treated with FPR1-stimulating RE-04-001, RE-04-006 or N-Formylmethionyl-leucyl-phenylalanine. The internal killing ability of neutrophils was assessed using a gentamicin protection assay. Light microscopy was used to investigate phagocytosis. Neutrophil morphology following FPR1 stimulation was observed using flow cytometry, and viability was tested with DRAQ7™. Finally, confocal microscopy assessed FPR1-driven NETosis. FPR1 stimulation was found to enhance intracellular killing of CFT-073 but not K12. Extracellular killing of K12 but not UPEC CFT-073 in the supernatant was enhanced by FPR1 activation. FPR1 stimulation was found to have no significant effects on the phagocytosis of E. coli, contrasting other findings in the literature. FPR1-stimulating compounds had no impact on neutrophil viability but caused a significant shift in their morphology. Finally, FPR1 stimulation was observed to induce NETosis in neutrophils after 3 hours but no NETosis was recorded in co-cultures with E. coli. This work highlights FPR1 as a target for immunostimulatory therapy which is a critical alternative to or co-therapy with antibiotic treatment in UTIs. |
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| Item Description: |
ORCiD identifier: https://orcid.org/0009-0006-5519-8845 |
| Keywords: |
Urinary tract infection, UPEC, Escherichia coli, Neutrophils, Reactive oxygen species, Formyl peptide receptor 1, Oxidative stress |
| College: |
Faculty of Medicine, Health and Life Sciences |
| Funders: |
Neutrocure |