A first insight into the effect of Lotilaner on GABA-gated channels from the european tick <em>Ixodes ricinus</em> - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Communication Dans Un Congrès Année : 2019

A first insight into the effect of Lotilaner on GABA-gated channels from the european tick Ixodes ricinus

Résumé

Ticks are strict blood-feeding arthropods (Acari), which represent a major health issue for wild or domesticated animals and humans, due to their potential to transmit disease agents. Control of ticks is increasingly difficult due to the development of drug-resistant parasites. Ligand-gated ion channels of the tick central nervous system are the primary targets of acaricides. Among those receptors, the γ-aminobutyric acid-gated chloride ion channels (GABACls) are the main synaptic inhibitory receptors. Lotilaner is a recently developed parasiticide from the isoxazoline chemical class that was shown to be a non-competitive antagonist of GABACls from the livestock tick Rhipicephalus microplus. In the present study, we characterized the GABACls from the European tick species Ixodes ricinus. We extracted RNAs from Ixodes ricinus nymphs. Taking advantage of the phylogenetic closeness of I. ricinus and R. microplus in the Arthropoda phylum, we identified the I. ricinus GABACl subunit homologue. The cDNA encoding the Iri- GABACl was cloned and the corresponding in vitro synthesized cRNAs were micro-injected into Xenopus laevis oocytes to investigate its pharmacological properties. Functional expression and two-electrode voltage clamp studies demonstrated that the GABACl subunit formed a homomeric receptor gated by GABA. Importantly, the insecticides like lotilaner, fipronil and picrotoxin efficiently blocked the GABA currents as previously observed for the R. microplus GABACl. Surprisingly, I. ricinus GABACl was not sensitive to the pesticide dieldrin, suggesting a potential naturally existing resistance mechanism involving alternative exons. Here we report the functional characterization of the first GABACl of I. ricinus demonstrating that it is an important molecular target for lotilaner. Transcriptomic analysis of I. ricinus are in progress to identify new acaricidal targets.
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Dates et versions

hal-02736790 , version 1 (02-06-2020)

Identifiants

  • HAL Id : hal-02736790 , version 1
  • PRODINRA : 494082

Citer

Claude Charvet, Clément Auger, Claude Rispe, Caroline Hervet, Elise Courtot, et al.. A first insight into the effect of Lotilaner on GABA-gated channels from the european tick Ixodes ricinus. 27. Conference of the World Association for the Advancement of Veterinary Parasitology, Jul 2019, Madison, United States. 349 p. ⟨hal-02736790⟩
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