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Project description:Drug resistance is a major public health challenge in Leishmaniasis chemotherapy, particularly in the case of emerging Leishmania/HIV-1 co-infections. Recently, we have delineated the mechanism of cell death induced by the HIV-1 protease inhibitor, Nelfinavir, in the Leishmania parasite. In order to investigate the underlying molecular mechanism involved in Nelfinavir resistance, in vitro Nelfinavir resistant amastigotes were developed by direct drug pressure in culture. RNA expression profiling analyses of closely related Leishmania species were used as a screening tool to compare Nelfinavir-resistant and -sensitive parasites in order to identify candidate genes involved in drug resistance, and several genes were found to be differentially expressed. Comparative gene hybridization (CGH) analyses of Nelfinavir-resistant and -sensitive Leishmania using whole-genome 60-mer oligonucleotide microarrays were also carried out. RNA expression profiles and the CGH of Nelfinavir resistant vs sensitive Leishmania amastigotes suggest that parasites regulate mRNA levels either by modulating gene copy numbers through chromosome aneuploidy, or gene deletion/duplication by homologous recombination. Interestingly, supernumerary chromosomes 6 and 11 in the resistant parasites lead to upregulation of the ABC class of transporters, which are involved in vesicular trafficking. Transporter assays using radiolabeled Nelfinavir suggest that the drug accumulates in greater amounts in the resistant parasites and in a time dependent manner. Furthermore, high-resolution electron microscopy showed an increased number of vacuoles in Nelfinavir-resistant parasites. Together these results suggest that Nelfinavir is rapidly and dramatically sequestered in these intracellular vesicles.
2013-06-27 | GSE42195 | GEO
Project description:Drug resistance is a major public health challenge in Leishmaniasis chemotherapy, particularly in the case of emerging Leishmania/HIV-1 co-infections. Recently, we have delineated the mechanism of cell death induced by the HIV-1 protease inhibitor, Nelfinavir, in the Leishmania parasite. In order to investigate the underlying molecular mechanism involved in Nelfinavir resistance, in vitro Nelfinavir resistant amastigotes were developed by direct drug pressure in culture. RNA expression profiling analyses of closely related Leishmania species were used as a screening tool to compare Nelfinavir-resistant and -sensitive parasites in order to identify candidate genes involved in drug resistance, and several genes were found to be differentially expressed. Comparative gene hybridization (CGH) analyses of Nelfinavir-resistant and -sensitive Leishmania using whole-genome 60-mer oligonucleotide microarrays were also carried out. RNA expression profiles and the CGH of Nelfinavir resistant vs sensitive Leishmania amastigotes suggest that parasites regulate mRNA levels either by modulating gene copy numbers through chromosome aneuploidy, or gene deletion/duplication by homologous recombination. Interestingly, supernumerary chromosomes 6 and 11 in the resistant parasites lead to upregulation of the ABC class of transporters, which are involved in vesicular trafficking. Transporter assays using radiolabeled Nelfinavir suggest that the drug accumulates in greater amounts in the resistant parasites and in a time dependent manner. Furthermore, high-resolution electron microscopy showed an increased number of vacuoles in Nelfinavir-resistant parasites. Together these results suggest that Nelfinavir is rapidly and dramatically sequestered in these intracellular vesicles. Two condition experiment: NFV-sensitive vs resistant. Biological replicates: Three. One dye swap.
2013-06-27 | E-GEOD-42195 | biostudies-arrayexpress
Project description:Drug resistance is a major public health challenge in Leishmaniasis chemotherapy, particularly in the case of emerging Leishmania/HIV-1 co-infections. Recently, we have delineated the mechanism of cell death induced by the HIV-1 protease inhibitor, Nelfinavir, in the Leishmania parasite. In order to investigate the underlying molecular mechanism involved in Nelfinavir resistance, in vitro Nelfinavir resistant amastigotes were developed by direct drug pressure in culture. RNA expression profiling analyses of closely related Leishmania species were used as a screening tool to compare Nelfinavir-resistant and -sensitive parasites in order to identify candidate genes involved in drug resistance, and several genes were found to be differentially expressed. Comparative gene hybridization (CGH) analyses of Nelfinavir-resistant and -sensitive Leishmania using whole-genome 60-mer oligonucleotide microarrays were also carried out. RNA expression profiles and the CGH of Nelfinavir resistant vs sensitive Leishmania amastigotes suggest that parasites regulate mRNA levels either by modulating gene copy numbers through chromosome aneuploidy, or gene deletion/duplication by homologous recombination. Interestingly, supernumerary chromosomes 6 and 11 in the resistant parasites lead to upregulation of the ABC class of transporters, which are involved in vesicular trafficking. Transporter assays using radiolabeled Nelfinavir suggest that the drug accumulates in greater amounts in the resistant parasites and in a time dependent manner. Furthermore, high-resolution electron microscopy showed an increased number of vacuoles in Nelfinavir-resistant parasites. Together these results suggest that Nelfinavir is rapidly and dramatically sequestered in these intracellular vesicles. Two condition experiment: NFV-sensitive vs resistant. Biological replicates: Three. One dye swap.
2013-06-27 | E-GEOD-42196 | biostudies-arrayexpress
Project description:Drug resistance is a major public health challenge in Leishmaniasis chemotherapy, particularly in the case of emerging Leishmania/HIV-1 co-infections. Recently, we have delineated the mechanism of cell death induced by the HIV-1 protease inhibitor, Nelfinavir, in the Leishmania parasite. In order to investigate the underlying molecular mechanism involved in Nelfinavir resistance, in vitro Nelfinavir resistant amastigotes were developed by direct drug pressure in culture. RNA expression profiling analyses of closely related Leishmania species were used as a screening tool to compare Nelfinavir-resistant and -sensitive parasites in order to identify candidate genes involved in drug resistance, and several genes were found to be differentially expressed. Comparative gene hybridization (CGH) analyses of Nelfinavir-resistant and -sensitive Leishmania using whole-genome 60-mer oligonucleotide microarrays were also carried out. RNA expression profiles and the CGH of Nelfinavir resistant vs sensitive Leishmania amastigotes suggest that parasites regulate mRNA levels either by modulating gene copy numbers through chromosome aneuploidy, or gene deletion/duplication by homologous recombination. Interestingly, supernumerary chromosomes 6 and 11 in the resistant parasites lead to upregulation of the ABC class of transporters, which are involved in vesicular trafficking. Transporter assays using radiolabeled Nelfinavir suggest that the drug accumulates in greater amounts in the resistant parasites and in a time dependent manner. Furthermore, high-resolution electron microscopy showed an increased number of vacuoles in Nelfinavir-resistant parasites. Together these results suggest that Nelfinavir is rapidly and dramatically sequestered in these intracellular vesicles.
2013-06-27 | GSE42196 | GEO
Project description:We explored the potential reprogramming of Leishmania infantum proteome during its stationary phase after an initial, single-dose exposure to EVs released by drug-resistant parasites
2022-06-13 | PXD034487 |
Project description:Leishmania are ancient eukaryotes that have retained the ability to produce extracellular vesicles (EVs) through evolution. Until date, it was unclear if different DNA entities could be associated to Leishmania EVs, and whether these could constitute a novel mechanism of horizontal gene transfer (HGT). Herein, we investigated the DNA content of EVs derived from drug-resistant parasites, as well as the potential of EVs as shuttles for DNA transfer. Next-generation sequencing, and PCR assays confirmed the enrichment of amplicons carrying drug-resistance genes associated to EVs. Transfer assays of drug-resistant EVs highlighted a significant impact in the phenotype of recipient parasites induced by the expression of the transferred DNA. Recipient parasites displayed an enhanced growth and better control of oxidative stress. We provide the first evidence that eukaryotic EVs function as efficient mediators in HGT, thereby facilitating the transmission of drug-resistance genes and increasing the fitness of cells when encountering stressful environments.
2022-07-19 | GSE200222 | GEO
Project description:Leishmaniasis is a group of diseases caused by parasites of the genus Leishmania that affects millions of people worldwide. The disease outcome is determined by both the parasite species and the host's immune response. Leishmania major infection causes a localized cutaneous lesion in patients and has been widely used to study the development of T cell responses in mice. L. major infected C57BL/6 mice are resistant to infection due to the development of Th1 responses, whereas BALB/c mice develop a Th2 response resulting in disease susceptibility and failure to control parasite replication. However, these disparate host phenotypes are not observed with all Leishmania species. For example, during L. braziliensis infection both BALB/c and C57BL/6 mice are resistant. In order to better understand the host genetic basis underlying disease susceptibility in vivo, we performed a whole genome transcriptional analysis from skin lesions of BALB/c and C57BL/6 mice infected intradermally for 4 weeks with either L. braziliensis or L. major.
2019-02-19 | GSE56029 | GEO
Project description:Leishmaniasis is a neglected tropical disease affecting millions of people worldwide. Emerging drug resistance of Leishmania species poses threaten to the effective control and elimination of this neglected tropical disease. Here we conducted whole genome resequencing, proteome profiling, and comparative analyses of a drug-resistant clinical isolate and two drug-susceptible strains of Leishmania donovani to explore genetic features that might contribute to the establishment of drug resistance in this parasite. By comparative genomic analysis, exclusive variations were identified in the drug-resistant isolate of L. donovani, including 86 copy number variations, 271 frameshift mutations in protein-coding genes and two site mutations in non-coding genes. Comparative proteomic analysis indicated significant differences in protein expression between resistant and susceptible strains of L. donovani, including 69 exclusive detected molecules and 84 consistent down-/up-regulations in the former. Integrating the genomic mutations and proteomic specificities linked nine of the genomic mutations (gene duplication, insertion and deletion) to significantly altered protein expression changes in the drug-resistant clinical isolate. These genetic features were inferred to be associated with nucleotide-binding and fatty acid metabolism (biosynthesis and degradation), which might contribute to fitness-gains allowing for the drug-resistant phenotype of L. donovani. This comparative and integrative work provided deep insights into the molecular basis underlying resistance establishment, suggesting new aspects to be investigated for novel intervention strategies against L. donovani and related species.
2021-09-09 | PXD017089 | Pride
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.
2023-04-04 | GSE173848 | GEO
Project description:Drug resistance threatens the effective control of infections, including parasitic diseases such as leishmaniases. Neutrophils are essential players in antimicrobial control, but their role in drug-resistant infections is poorly understood. Here, we evaluated human neutrophil response to clinical parasite strains having distinct natural drug susceptibility. We found that Leishmania antimony drug resistance significantly altered the expression of neutrophil genes, some of them transcribed by specific neutrophil subsets. Infection with drug-resistant parasites increased the expression of detoxification pathways and reduced the production of cytokines. Among these, the chemokine CCL3 was predominantly impacted, which resulted in an impaired ability of neutrophils to attract myeloid cells. Moreover, decreased myeloid recruitment when CCL3 levels are reduced was confirmed by blocking CCL3 in a mouse model. Collectively, these findings reveal that the interplay between naturally drug-resistant parasites and neutrophils modulates the infected skin immune microenvironment, revealing a key role of neutrophils in drug resistance.
2024-04-23 | GSE244972 | GEO