Dataset Information

A novel marker, ARM58, confers antimony resistance to Leishmania spp.

ABSTRACT: Protozoa of the Leishmania genus cause a variety of disease forms that rank at the top of the list of neglected tropical diseases. Anti-leishmanial drugs based on pentavalent antimony have been the mainstay of therapy for over 60 years and resistance against them is increasingly encountered in the field. The biochemical basis for this is poorly understood and likely diverse. No stringent correlation between genetic markers and antimony resistance has so far been shown, prompting us to use a functional cloning approach to identify markers of resistance. Using gene libraries derived from drug-resistant and drug-sensitive Leishmania braziliensis clinical isolates in a functional cloning strategy, we repeatedly selected one gene locus located on chromosome 20 whose amplification confers increased antimony (III) resistance in vitro to an otherwise sensitive L. braziliensis clone. The gene responsible for the effect encodes a previously hypothetical protein that we dubbed LbrARM58. It comprises four repeats of a domain of unknown function, DUF1935, one of them harbouring a potential trans-membrane domain. The gene is so far unique to the Leishmania genus, while a structurally related gene without antimony resistance functionality is also found in Trypanosoma spp. Overexpression of LbrARM58 also confers antimony resistance to promastigotes and intracellular amastigotes of the related species Leishmania infantum, indicating a conserved function in Old World and New World Leishmania species. Our results also show that in spite of their RNAi system, L. braziliensis promastigotes can serve as acceptor cells for episomally propagated cosmid libraries, at least for the initial stages of functional cloning efforts.

SUBMITTER: Nuhs A

PROVIDER: S-EPMC3940081 | biostudies-other | 2014 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

A novel marker, ARM58, confers antimony resistance to Leishmania spp.

Nühs Andrea A Schäfer Carola C Zander Dorothea D Trübe Leona L Tejera Nevado Paloma P Schmidt Sonja S Arevalo Jorge J Adaui Vanessa V Maes Louis L Dujardin Jean-Claude JC Clos Joachim J

International journal for parasitology. Drugs and drug resistance 20131206 1

Protozoa of the Leishmania genus cause a variety of disease forms that rank at the top of the list of neglected tropical diseases. Anti-leishmanial drugs based on pentavalent antimony have been the mainstay of therapy for over 60 years and resistance against them is increasingly encountered in the field. The biochemical basis for this is poorly understood and likely diverse. No stringent correlation between genetic markers and antimony resistance has so far been shown, prompting us to use a func ...[more]

PMID: 24596667

Similar Datasets

Project description:Purpose: In this study, we have used a translatomic approach by coupling polysome profiling and deep RNA-sequencing to estimate changes in the translatome of antimony-resistant Leishmania parasites Methods: Leishmania tropica promastigotes were stepwise selected for resistance to trivalent antimony. Two different strains were studied, the L. tropica SbIII-sensitive or wildtype strain (WT) and the derived highly resistant strain (HR). After polysome profiling four types of samples were evaluated by deep RNAseq: total mRNA used as input, monosomes (MS), light polysomes (LP), and heavy polysomes (HP). The DESeq2 algorithm was used for differential expression analysis to identify translational changes at the basal level (HR Vs. WT), translational changes to combat the drug (HR+SbIII Vs. HR), and to compare translatomic Vs. transcriptomic changes (HP Vs. Total input) [see overall design section below]. Results: Differential translational analysis (cutoff of fold change ≥ 1.5 and p-value corrected by Benjamini-Hochberg FDR ≤ 0.05) showed that transcripts composition per polysome fraction was different in the resistant strain. It included several upregulated (Up) and downregulated (Down) transcripts. At the basal level, 2431 different transcripts were differentially translated: monosome (Down: 4, Up: 0), light polysomes (Down: 906, Up: 951), and heavy polysomes (Down: 1096, Up: 1064). Under the antimony challenge, 189 different transcripts were differentially translated: monosome (Down: 0, Up: 2), light polysomes (Down: 9, Up: 57), and heavy polysomes (Down: 30, Up: 134). Overall, most of the changes were identified in polysome fraction when compared with monosomes or total transcriptome. Conclusions: Our study shows evidence that translational control has a main role in coordinating the resistance to antimony in Leishmania parasites. We propose a novel model that establishes translational control as a major driver of antimony-resistant phenotypes in Leishmania parasites.

Project description:Antimonials (Sb) were used for decades for chemotherapy of visceral leishmaniasis (VL). Now abandoned in the Indian subcontinent (ISC) because of Leishmania donovani resistance, this drug offers a unique model for understanding drug resistance dynamics. In a previous phylogenomic study, we found two distinct populations of L. donovani: the core group (CG) in the Gangetic plains and ISC1 in the Nepalese highlands. Sb resistance was only encountered within the CG, and a series of potential markers were identified. Here, we analyzed the development of resistance to trivalent antimonials (SbIII) upon experimental selection in ISC1 and CG strains. We observed that (i) baseline SbIII susceptibility of parasites was higher in ISC1 than in the CG, (ii) time to SbIII resistance was higher for ISC1 parasites than for CG strains, and (iii) untargeted genomic and metabolomic analyses revealed molecular changes along the selection process: these were more numerous in ISC1 than in the CG. Altogether these observations led to the hypothesis that CG parasites are preadapted to SbIII resistance. This hypothesis was experimentally confirmed by showing that only wild-type CG strains could survive a direct exposure to the maximal concentration of SbIII The main driver of this preadaptation was shown to be MRPA, a gene involved in SbIII sequestration and amplified in an intrachromosomal amplicon in all CG strains characterized so far. This amplicon emerged around 1850 in the CG, well before the implementation of antimonials for VL chemotherapy, and we discuss here several hypotheses of selective pressure that could have accompanied its emergence.IMPORTANCE The "antibiotic resistance crisis" is a major challenge for scientists and medical professionals. This steady rise in drug-resistant pathogens also extends to parasitic diseases, with antimony being the first anti-Leishmania drug that fell in the Indian subcontinent (ISC). Leishmaniasis is a major but neglected infectious disease with limited therapeutic options. Therefore, understanding how parasites became resistant to antimonials is of commanding importance. In this study, we experimentally characterized the dynamics of this resistance acquisition and show for the first time that some Leishmania populations of the ISC were preadapted to antimony resistance, likely driven by environmental factors or by drugs used in the 19th century.

Dataset Information

A novel marker, ARM58, confers antimony resistance to Leishmania spp.

Publications

A novel marker, ARM58, confers antimony resistance to Leishmania spp.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets