The University of Southampton
University of Southampton Institutional Repository

Deciphering the molecular determinants of cholinergic anthelmintic sensitivity in nematodes: When novel functional validation approaches highlight major differences between the model Caenorhabditis elegans and parasitic species

Deciphering the molecular determinants of cholinergic anthelmintic sensitivity in nematodes: When novel functional validation approaches highlight major differences between the model Caenorhabditis elegans and parasitic species
Deciphering the molecular determinants of cholinergic anthelmintic sensitivity in nematodes: When novel functional validation approaches highlight major differences between the model Caenorhabditis elegans and parasitic species
Cholinergic agonists such as levamisole and pyrantel are widely used as anthelmintics to treat parasitic nematode infestations. These drugs elicit spastic paralysis by activating acetylcholine receptors (AChRs) expressed in nematode body wall muscles. In the model nematode Caenorhabditis elegans, genetic screens led to the identification of five genes encoding levamisole-sensitive-AChR (L-AChR) subunits: unc-38, unc-63, unc-29, lev-1 and lev-8. These subunits form a functional L-AChR when heterologously expressed in Xenopus laevis oocytes. Here we show that the majority of parasitic species that are sensitive to levamisole lack a gene orthologous to C. elegans lev-8. This raises important questions concerning the properties of the native receptor that constitutes the target for cholinergic anthelmintics. We demonstrate that the closely related ACR-8 subunit from phylogenetically distant animal and plant parasitic nematode species functionally substitutes for LEV-8 in the C. elegans L-AChR when expressed in Xenopus oocytes. The importance of ACR-8 in parasitic nematode sensitivity to cholinergic anthelmintics is reinforced by a ‘model hopping’ approach in which we demonstrate the ability of ACR-8 from the hematophagous parasitic nematode Haemonchus contortus to fully restore levamisole sensitivity, and to confer high sensitivity to pyrantel, when expressed in the body wall muscle of C. elegans lev-8 null mutants. The critical role of acr-8 to in vivo drug sensitivity is substantiated by the successful demonstration of RNAi gene silencing for Hco-acr-8 which reduced the sensitivity of H. contortus larvae to levamisole. Intriguingly, the pyrantel sensitivity remained unchanged thus providing new evidence for distinct modes of action of these important anthelmintics in parasitic species versus C. elegans. More broadly, this highlights the limits of C. elegans as a predictive model to decipher cholinergic agonist targets from parasitic nematode species and provides key molecular insight to inform the discovery of next generation anthelmintic compounds.
1553-7366
Blanchard, Alexandra
72427d57-cf54-49f2-8c85-21ed96e0c85a
Guégnard, Fabrice
4658f573-7655-4b1b-9923-81430da7cf0e
Charvet, Claude L.
c0436a6e-8e1a-4073-9cbf-c3d3c5df25a1
Crisford, Anna
135675e1-a172-4d93-989b-93d1efb022c3
Courtot, Elise
26996726-8a53-489a-9c46-63873f48c4f6
Sauvé, Christine
b04193cd-c5d1-4899-ab47-df722185e561
Harmache, Abdallah
a30da77c-6385-47a6-ba7a-d191d7f631fd
Duguet, Thomas
a90a0e02-ee55-4480-aa44-227e0cfaf7b9
O’Connor, Vincent
8021b06c-01a0-4925-9dde-a61c8fe278ca
Castagnone-Sereno, Philippe
258d332e-b87b-4dfb-8cab-65d6fee38662
Reaves, Barbara
bcf3443a-9b84-41a3-a579-ddda728552e4
Wolstenholme, Adrian J.
d2435238-9dfe-4b96-8cf8-82f47f7ed94a
Beech, Robin N.
dff8610f-f1d9-4c07-9f1c-c012319808eb
Holden-Dye, Lindy
8032bf60-5db6-40cb-b71c-ddda9d212c8e
Neveu, Cedric
e982e088-7835-4ba6-ad49-8c4949781c78
Blanchard, Alexandra
72427d57-cf54-49f2-8c85-21ed96e0c85a
Guégnard, Fabrice
4658f573-7655-4b1b-9923-81430da7cf0e
Charvet, Claude L.
c0436a6e-8e1a-4073-9cbf-c3d3c5df25a1
Crisford, Anna
135675e1-a172-4d93-989b-93d1efb022c3
Courtot, Elise
26996726-8a53-489a-9c46-63873f48c4f6
Sauvé, Christine
b04193cd-c5d1-4899-ab47-df722185e561
Harmache, Abdallah
a30da77c-6385-47a6-ba7a-d191d7f631fd
Duguet, Thomas
a90a0e02-ee55-4480-aa44-227e0cfaf7b9
O’Connor, Vincent
8021b06c-01a0-4925-9dde-a61c8fe278ca
Castagnone-Sereno, Philippe
258d332e-b87b-4dfb-8cab-65d6fee38662
Reaves, Barbara
bcf3443a-9b84-41a3-a579-ddda728552e4
Wolstenholme, Adrian J.
d2435238-9dfe-4b96-8cf8-82f47f7ed94a
Beech, Robin N.
dff8610f-f1d9-4c07-9f1c-c012319808eb
Holden-Dye, Lindy
8032bf60-5db6-40cb-b71c-ddda9d212c8e
Neveu, Cedric
e982e088-7835-4ba6-ad49-8c4949781c78

Blanchard, Alexandra, Guégnard, Fabrice, Charvet, Claude L., Crisford, Anna, Courtot, Elise, Sauvé, Christine, Harmache, Abdallah, Duguet, Thomas, O’Connor, Vincent, Castagnone-Sereno, Philippe, Reaves, Barbara, Wolstenholme, Adrian J., Beech, Robin N., Holden-Dye, Lindy and Neveu, Cedric (2018) Deciphering the molecular determinants of cholinergic anthelmintic sensitivity in nematodes: When novel functional validation approaches highlight major differences between the model Caenorhabditis elegans and parasitic species. PLOS Pathogens, 14 (5), [e1006996]. (doi:10.1371/journal.ppat.1006996).

Record type: Article

Abstract

Cholinergic agonists such as levamisole and pyrantel are widely used as anthelmintics to treat parasitic nematode infestations. These drugs elicit spastic paralysis by activating acetylcholine receptors (AChRs) expressed in nematode body wall muscles. In the model nematode Caenorhabditis elegans, genetic screens led to the identification of five genes encoding levamisole-sensitive-AChR (L-AChR) subunits: unc-38, unc-63, unc-29, lev-1 and lev-8. These subunits form a functional L-AChR when heterologously expressed in Xenopus laevis oocytes. Here we show that the majority of parasitic species that are sensitive to levamisole lack a gene orthologous to C. elegans lev-8. This raises important questions concerning the properties of the native receptor that constitutes the target for cholinergic anthelmintics. We demonstrate that the closely related ACR-8 subunit from phylogenetically distant animal and plant parasitic nematode species functionally substitutes for LEV-8 in the C. elegans L-AChR when expressed in Xenopus oocytes. The importance of ACR-8 in parasitic nematode sensitivity to cholinergic anthelmintics is reinforced by a ‘model hopping’ approach in which we demonstrate the ability of ACR-8 from the hematophagous parasitic nematode Haemonchus contortus to fully restore levamisole sensitivity, and to confer high sensitivity to pyrantel, when expressed in the body wall muscle of C. elegans lev-8 null mutants. The critical role of acr-8 to in vivo drug sensitivity is substantiated by the successful demonstration of RNAi gene silencing for Hco-acr-8 which reduced the sensitivity of H. contortus larvae to levamisole. Intriguingly, the pyrantel sensitivity remained unchanged thus providing new evidence for distinct modes of action of these important anthelmintics in parasitic species versus C. elegans. More broadly, this highlights the limits of C. elegans as a predictive model to decipher cholinergic agonist targets from parasitic nematode species and provides key molecular insight to inform the discovery of next generation anthelmintic compounds.

Text
journal.ppat.1006996 - Version of Record
Available under License Creative Commons Attribution.
Download (3MB)

More information

Accepted/In Press date: 18 April 2018
e-pub ahead of print date: 2 May 2018
Published date: 2 May 2018

Identifiers

Local EPrints ID: 420454
URI: http://eprints.soton.ac.uk/id/eprint/420454
ISSN: 1553-7366
PURE UUID: 7097f0bb-57ed-4cd8-b6a7-1aab21e98063
ORCID for Anna Crisford: ORCID iD orcid.org/0000-0001-5775-643X
ORCID for Vincent O’Connor: ORCID iD orcid.org/0000-0003-3185-5709
ORCID for Lindy Holden-Dye: ORCID iD orcid.org/0000-0002-9704-1217

Catalogue record

Date deposited: 08 May 2018 16:30
Last modified: 16 Mar 2024 03:58

Export record

Altmetrics

Contributors

Author: Alexandra Blanchard
Author: Fabrice Guégnard
Author: Claude L. Charvet
Author: Anna Crisford ORCID iD
Author: Elise Courtot
Author: Christine Sauvé
Author: Abdallah Harmache
Author: Thomas Duguet
Author: Philippe Castagnone-Sereno
Author: Barbara Reaves
Author: Adrian J. Wolstenholme
Author: Robin N. Beech
Author: Cedric Neveu

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×