Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts

Toll-like receptors (TLRs) recognise a wide range of molecular patterns, and are key in activation and coordination of the innate and adaptive immune responses. TLR ligands include pathogen-associated and damage-associated molecular patterns (PAMPs and DAMPs, respectively), as well as an increasing...

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Main Author: Thirlaway, Khalil
Format: Thesis (University of Nottingham only)
Language:English
Published: 2018
Subjects:
Online Access:https://eprints.nottingham.ac.uk/52526/
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author Thirlaway, Khalil
author_facet Thirlaway, Khalil
author_sort Thirlaway, Khalil
building Nottingham Research Data Repository
collection Online Access
description Toll-like receptors (TLRs) recognise a wide range of molecular patterns, and are key in activation and coordination of the innate and adaptive immune responses. TLR ligands include pathogen-associated and damage-associated molecular patterns (PAMPs and DAMPs, respectively), as well as an increasing number of plant-derived ligands. Novel TLR ligands represent promising potential therapeutics, for example as vaccine adjuvants or selectively immunosuppressive drugs. Exploiting Malaysia’s diverse and largely unexplored repertoire of endemic plant species, lyophilised extracts of leaf and bark tissue from various species were screened for stimulatory or inhibitory activity in four stably transfected HEK cell lines expressing TLR 2/1, 2/6, 4 and 5. Extracts showing significant changes in CXCL8 production relative to controls were fractionated to identify active components, and chemically modified to identify functional molecular groups. To better assess biological relevance of any effects, active extracts were tested for modulation of class-switching and proliferation in primary murine splenic B-lymphocytes. Of the 21 extracts screened, three showing interactions with TLR2/6 were chosen for further analysis: 1402EtL and 1412EtB showed stimulatory activity and 1404EtL showed inhibitory activity. 1402EtL was insoluble in aqueous solution, which prevented further characterisation, but a >100kDa active fraction of 1412EtB and a 10-30kDa active fraction of 1404EtL were identified. Neither boiling nor acid-treatment affected the stimulatory activity of 1412EtB, but oxidation with metaperiodate eliminated activity. None of the three treatments affected the inhibitory activity of 1404EtL. In primary murine B-cells 1402EtL was found to induce IgG1 isotype switching and crude 1412EtB induced proliferation and upregulation of IgM expression. The acid-treated, boiled and >100kDa forms of 1412EtB produced a stronger proliferative and IgM response, as well as inducing IgG1 class switching. These data suggest that these plants represent promising candidates for development of novel TLR-mediated immunomodulatory pharmaceuticals.
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format Thesis (University of Nottingham only)
id nottingham-52526
institution University of Nottingham Malaysia Campus
institution_category Local University
language English
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publishDate 2018
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spelling nottingham-525262025-02-28T14:10:55Z https://eprints.nottingham.ac.uk/52526/ Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts Thirlaway, Khalil Toll-like receptors (TLRs) recognise a wide range of molecular patterns, and are key in activation and coordination of the innate and adaptive immune responses. TLR ligands include pathogen-associated and damage-associated molecular patterns (PAMPs and DAMPs, respectively), as well as an increasing number of plant-derived ligands. Novel TLR ligands represent promising potential therapeutics, for example as vaccine adjuvants or selectively immunosuppressive drugs. Exploiting Malaysia’s diverse and largely unexplored repertoire of endemic plant species, lyophilised extracts of leaf and bark tissue from various species were screened for stimulatory or inhibitory activity in four stably transfected HEK cell lines expressing TLR 2/1, 2/6, 4 and 5. Extracts showing significant changes in CXCL8 production relative to controls were fractionated to identify active components, and chemically modified to identify functional molecular groups. To better assess biological relevance of any effects, active extracts were tested for modulation of class-switching and proliferation in primary murine splenic B-lymphocytes. Of the 21 extracts screened, three showing interactions with TLR2/6 were chosen for further analysis: 1402EtL and 1412EtB showed stimulatory activity and 1404EtL showed inhibitory activity. 1402EtL was insoluble in aqueous solution, which prevented further characterisation, but a >100kDa active fraction of 1412EtB and a 10-30kDa active fraction of 1404EtL were identified. Neither boiling nor acid-treatment affected the stimulatory activity of 1412EtB, but oxidation with metaperiodate eliminated activity. None of the three treatments affected the inhibitory activity of 1404EtL. In primary murine B-cells 1402EtL was found to induce IgG1 isotype switching and crude 1412EtB induced proliferation and upregulation of IgM expression. The acid-treated, boiled and >100kDa forms of 1412EtB produced a stronger proliferative and IgM response, as well as inducing IgG1 class switching. These data suggest that these plants represent promising candidates for development of novel TLR-mediated immunomodulatory pharmaceuticals. 2018-07-12 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/52526/1/Khalil%20Thirlaway%20FINAL%20CORRECTIONS%20Characterising%20novel%20TLR%20dependent%20immunomodulators%20from%20tropical%20plant%20extracts.pdf Thirlaway, Khalil (2018) Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts. PhD thesis, University of Nottingham. Immunology Immunomodulation Plant based medicine Phytotherapy Bioprospecting TLR Toll-like receptors innate immunity PRR pattern recognition receptors
spellingShingle Immunology
Immunomodulation
Plant based medicine
Phytotherapy
Bioprospecting
TLR
Toll-like receptors
innate immunity
PRR
pattern recognition receptors
Thirlaway, Khalil
Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts
title Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts
title_full Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts
title_fullStr Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts
title_full_unstemmed Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts
title_short Characterisation of novel TLR-dependent immunomodulators from tropical plant extracts
title_sort characterisation of novel tlr-dependent immunomodulators from tropical plant extracts
topic Immunology
Immunomodulation
Plant based medicine
Phytotherapy
Bioprospecting
TLR
Toll-like receptors
innate immunity
PRR
pattern recognition receptors
url https://eprints.nottingham.ac.uk/52526/