Hub members Have many expertise, covering most of the fields in bioinformatics and biostatistics. You'll find below a non-exhaustive list of these expertise
Searched keyword : Parasite
Related people (2)
Initially trained in evolutionary and environmental sciences, I studied population genetics and micro-evolutionary processes in a number of postdoctoral research projects. I recently joined the C3BI-Hub at the Institut Pasteur, where I work on various aspects involving Biostatistics and the analysis of genetic data.
Association studiesGenomicsGenotypingBiostatisticsGeneticsEvolutionPopulation genetics
BacteriaParasiteHumanInsect or arthropodOther animal
Rachel Legendre is a bioinformatics engineer. She completed her master degree in apprenticeship for two years at INRA in Jouy-en-Josas in the Genetic Animal department. She was involved in a project aiming at the detection and the expression analysis of micro-RNA involved in an equine disease. In 2012, she joined the Genomic, Structure and Translation Team at Paris-Sud (Paris XI) university. She worked principally on Ribosome Profiling data analysis, a new technique that allows to identify the position of the ribosome on the mRNA at the nucleotide level. Since november 2015, she worked at Institut Pasteur. During 4 years, she was detached to the Biomics Platform, where she was in charge of the bioinformatics analyses for transcriptomics and epigenomics projects. She was also involved in Long Reads (PacBio and Nanopore) developments with other bioinformaticians of Biomics. Since november 2019, she has joined the Hub of Bioinformatics and Biostatistics, et more precisely the Genome Organization Regulation and Expression group.
AlgorithmicsChIP-seqEpigenomicsNon coding RNATranscriptomicsGenome analysisProgram developmentScientific computingSofware development and engineeringIllumina HiSeqRead mappingSequencingWorkflow and pipeline developmentChromatin accessibility assaysPac BioRibosome profiling
BacteriaFungiParasiteHumanInsect or arthropodOther animal
- Exploring pathogenic mechanisms of chronic inflammatory disease: unresolved issues in IL-23/IL-17 biology(YAHIA HANANE - Immunoregulation) - Pending
- Identification of factors influencing the activity of bacteriophage within the gut of mammals(Devon CONTI - Other) - In Progress
- HKA: systemic analysis of two-component signalling(Arnaud FIRON - Biology of Gram-Positive Pathogens) - In Progress
Related projects (34)
Across bacterial, archaeal and eukaryotic kingdoms, heat shock proteins (HSPs) are defined as a class of highly conserved chaperone proteins that are rapidly induced in response to temperature increase through dedicated heat shock transcription factors. While this transcriptional response governs cellular adaptation of fungal, plant and animal cells to thermic shock and other forms of stress, early-branching eukaryotes of the kinetoplastid order, including trypanosomatid parasites, lack classical mechanisms of transcriptional regulation and show largely constitutive expression of HSPs, thus raising important questions on the function of HSPs in the absence of stress and the regulation of their chaperone activity in response to environmental adversity. Understanding parasite-specific mechanisms of stress-response regulation is especially relevant for protozoan parasites of the genus Leishmania that are adapted for survival inside highly toxic phagolysosomes of host macrophages causing the various immuno-pathologies of leishmaniasis. To gain first insight into the role the heat shock repsonse for Leishmania differentiation and pathogenicity, we are studying the evolution and function of members of the HSP70 protein family combining bio-informatics and transgenics apporahces.
The aim of the project is to create a viewer that will help visualisation and correlation between genomic, transcriptomic, proteomic and metabolomic data generated by the comparison of amastigote and promastigote stages of the Leishmania donovani parasite.
Mise a disposition d'un(e) bioinformaticien(ne) du hub pour les analyses bioinformatiques du transcriptome et de l epigenome
La PF Transcriptome et Epigenome développe des projets de séquençage à haut débit (collaboration et service) avec des équipes du Campus. Ceux-ci couvrent l'ensemble des thématiques du campus ainsi qu'une large gamme d'organismes (des virus aux mammifères). La plate-forme exerce des activités de biologie humide (construction des librairies et séquençage) et de biologie sèche (analyse bioinformatiques et statistiques). La personne mise a disposition interagira étroitement avec les autres bioinformaticiens du pôle BioMics et du Hub. Ses activités concerneront notamment: - La participation à la conception et à la mise en place des projets avec les équipes demandeuses, la prise en charge des analyses et le reporting aux utilisateurs - La mise en place d'un workflow d'analyse bioinformatique des données de transcriptome /épigénome en étroite collaboration avec le C3BI, la DSI et les autres bioinformaticiens du pole. Ce workflow permettra le contrôle qualité des données, leur prétraitement, le mapping des séquences sur les génomes/transcriptomes de réference, et le comptage des reads pour les différents éléments de l'annotation - L'adaptation du workflow d'analyse aux questions biologiques et aux organismes étudiés dans le cadre des activités de la PF - L'activité de veille technologique et bibliographique (test et validation de nouveaux outils d'analyse, updates d'outils existants...) - La mise en place et le développement d'outils d'analyse adaptés aux futurs projets de la PF: single cell RNAseq, métatranscriptome, ChIPseq, analyse des isoformes de splicing.. Ceci se fera notamment via la réalisation d'analyses dédiées avec certains utilisateurs. Les outils mis en place et validés dans ce cadre seront ensuite utilisés pour l'ensemble des projets. - L'activité de communication et de formation (participation aux réunions du consortium France Génomique,formation permanente à l' Institut Pasteur… - la participation a d autres projets du Pole BioMics (selon disponibilité) Bernd Jagla, qui était le bioinformaticien de la plateforme a rejoint le Hub au 1er janvier 2016. Rachel Legendre est mise a disposition depuis le 2 novembre 2015 et remplace Bernd Jagla. Je souhaite que Rachel Legendre soit mise à disposition de la plateforme pour une durée d'au moins 2 ans.
The Sudanese L. donovani strain Ld1SA is the most important experimental reference strain in our field and has been used for various systems level analysis (DNAseq, RNAseq, proteomics). However, all these analyses are strongly compromised by the fact that the current L. donovani genome reference strain LdBPK is from Nepal and very different from the Sudanese isolate (only 60% of DNAseq reads can be mapped).
BioHub LeiSHield project This proposal summarizes the contribution of the BioHub to the LeiSHield action that may be carried out by a single BioHub Leishmania coordinator (Giovanni Bussotti). The coordinator will be implicated in the following actions: 1) Establish the link between LeiSHield members and the BioHub team for all questions regarding data analysis and interpretation. The coordinator will present to the BioHub the bio-informatics needs of the LeiSHield partners. Short (easy) tasks will be answered directly (following the BioHub open door strategy). For more involved tasks i twill be asked to deposit projects via the C3BI web site. 2) Coordinate the setup of an HTseq analysis pipeline, including quality control, read mapping, determination of CNV and SNPs, and data visualization using a combination of tools available at the BioHub, such as SyntView and Listeriomics. A link to Cedric Notredame will be established as scripts for Leishmania have been created there. 3) Oversee the submission of DNA from the different LeiSHield WPs to the IP HTseq facility, follow the progress, store the acquired data, and dispatch the datasets to the corresponding WP leaders. This will be coordinate with the Biomix infrastrcuture. 4) Apply the HTseq analysis pipeline (see point 1) on selected data sets for defined work packages, including WP4 (“Analysis of newly isolated anthroponotic L. donovani s.l. strains from Cyprus and correlation of genotypic profiles to tropism and drug resistance”), WP6 (“Population genetics of Brazilian L. infantum isolates from endemic areas presenting distinct transmission cycle”), WP7 (“Leishmania dovovani genome sequence diversity and disease tropism in the Sudan”), and WP9 (“Systems-wide analysis of Leishmania genomic and transcriptomic adaptation”). 5) Co-organize a course on HTseq data visualization (June 2016) with members of the BioHub team.
ANALYSIS OF TRANSCRIPTIONAL MODULATIONS RELATED TO CELL DEATH PROCESSES IN MURINE BONE-MARROW DERIVED MACROPHAGES AND DENDRITIC CELLS INFECTED BY LEISHMANIA AMAZONENSIS
Aim : In vitro infection of innate immune cells by L. amazonensis (L.am.) seems to be associated to an increase in resistance to cell death of infected cells. This project aims at deciphering the impact of in vitro L. amazonensis (L.am.) amastigotes infection on cell death processes including apoptosis, autophagy, pyroptosis and necroptosis in different host cells, i.e. Bone-marrow- derived macrophages (BMDMs) and dendritic cells (BMDCs) after one day of infection. Material : RNA samples were obtained from control and infected BMDMs (BALB/c mice) or BMDCs (BALB/c, C57BL/6 and DBA/2 mice) after their sorting by Fluorescence Activated- Cell sorting. For BALB/c BMDCs, amastigotes were also added to cells in presence of immune serum to trigger their opsonization. Samples were analysed a few years ago at the « Plateforme Transcriptome et Epigénome » with the Affymetrix technology. RNAs from BMDMs and BMDCs were analysed with the Affymetrix Mouse430_2 GeneChips and the Affymetrix Mouse Gene ST 1.0 arrays respectively.
ANALYSIS OF TRANSCRIPTIONNAL MODULATIONS INDUCED IN C57BL/6 BONE-MARROW DERIVED MACROPHAGES INFECTED BY LEISHMANIA AMAZONENSIS IN PRESENCE OR ABSENCE OF INFLAMMASOME-ACTIVATING CONDITIONS
Aim : When L. amazonensis (L.am.) amastigotes infect BMDMs, they induce multiple strategies to allow their survival and multiplication. This project aims at deciphering the transcriptional modulations induced after three days of in vitro infection of C57BL/6 BMDMs with L. amazonensis (L.am.) amastigotes, in unstimulated conditions, or conditions that induce NLRP3 inflammasome activation.
Mining the Plasmodium genome to identify novel blood stage antigens for use as malaria vaccine candidates
Malaria remains a major problem in many tropical countries with Plasmodium falciparum accounting for up to 1 million deaths, primarily in infants and children residing in endemic areas of sub-Saharan Africa. P. vivax, the other important species for human malaria is geographically more widespread and causes 80-100 million cases of malaria each year. All the pathology related to malaria is attributed to the blood stage of the parasite life cycle during which Plasmodium merozoites invade and multiply within host erythrocytes. We are interested in understanding the process of RBC invasion by malaria parasites at the molecular level with the goal of blocking their interaction with antibodies to inhibit invasion and kill the parasite. The first generation of recombinant blood stage malaria vaccine candidates based on antigens such as the merozoite surface protein (MSP1) and apical merozoite antigen-1 (AMA01) have been tested in field trials and failed to provide any efficacy against P. falciparum malaria. There is thus an urgent need to identify novel parasite antigens that play a role in invasion and can serve as vaccine candidates that elicit strong antibody responses that block blood stage parasite growth. In this project, we propose to mine the P. falciparum and P. vivax genome databases using bio-informatic tools to identify potential, novel blood stage invasion related parasite antigens that can serve as potential candidates for blood stage malara vaccines. Criteria such as expression profile, presence of conserved domains in orthologs from related plasmodium species, limited polymorphisms in field isolates, interaction with other invasion related proteins and localization to apical organelles or merozoite surface will be used to interrogate P. falciparum and P. vivax genome sequence data and identify potential invasion related antigens that will be selected for validation as vaccine candidates for malaria.
Chromosome amplification is commonly used by Leishmania during adaptation to environment. In this context it is challenging to look for genes relevant for parasite virulence/attenuation/drug resistance... To restrict this chromosomal amplification, a cosmid approach (CoSeq) has been chosen to select for genes that provide fitness gain to Leishmania donovani parasites in culture and in the animal. Therefore, a cosmid library has been generated with genomic DNA from the parasites which needs to be sequenced to control for genome coverage before transfection to the parasites. The transfected parasites will then be injected to animals or submitted to different culture conditions. Only those transfected with cosmids providing advantage under the studied conditions will be selected and will replicate. These cosmids will be extracted from the parasites and will be sequenced to reveal genes relevant for the parasite survival. The C3Bi would be implicated in the analyses of the sequencing data obtained from the PF1 (retrieve the data, mapping of the reads to Leishmania genome, estimation of the genome coverage, listing of genes selected for a given condition...).
Background: PLA2 is known to regulate vesicle secretion in diverse eukaryotic cells. We are interested in determining the putative role of PLA2 in secretion of apical vesicular organelles called micronemes and rhoptries in P. falciparum merozoites. PLA2 inhibitors such as 4-BPB are known to block growth of the related Apicomplexan parasite Toxoplasma gondii. There are 3 annotated PLA2 genes in the P. falciparum genome database (Pf3D70209100, PF3D71358000, PF3D70924000). We would like to analyze these putative PLA2 genes using bioinformatics to support our drug development studies.
Prediction of RNA-RNA interactions between a family of GC-rich ncRNAs and nascent transcripts of virulence genes in Plasmodium falciparum
In Plasmodium falciparum a virulence gene family with 60 var genes codes for the PfEMP1 surface proteins, which undergo antigenic variation. This epigenetically controlled mechanism promotes immune evasion of the parasite. As ncRNAs are emerging as relevant regulators of gene expression we are investigating a GC-rich ncRNA gene family consisting of 15 highly homologous members all positioned next to var gene clusters. We recently found that GC-rich ncRNA transcript associates with the distinct nuclear expression site in which a single var gene is transcribed. We hypothesize that GC-rich ncRNAs interact with the nascent mRNA of var virulence genes. We intend to predict potential RNA-RNA interaction with thermodynamic calculation provided by the RNAup software. In silico prediction of potential binding sites and strength of interaction will help to generate hypotheses and inform our further experimental design.
Identification of new or unexpected pathogens, including viruses, bacteria, fungi and parasites associated with acute or progressive diseases
Microbial discovery remains a challenging task for which there are a lot of unmet medical and public health needs. Deep sequencing has profoundly modified this field, which can be summarized in two questions : i) which pathogens or association of pathogens are associated with diseases of unknown etiology and ii) among microbes infecting animal (including arthropod) reservoirs, which ones are able to infect large vertebrates, including humans. We are currently addressing these two questions and our current request comes with the willingness for Institut Pasteur to increase its contribution and visibility of this thematic, in particular in relation with hospitals and the Institut Pasteur International network (IPIN). We expect to identify new microbes associated with human diseases, and this is expected to pave the way for basic research programs focusing on virulence mechanisms and host specificity, and will also lead to phylogenetic and epidemiological studies (frequency of host infection, mode of transmission etc...), as well as the development of improved diagnostic tests for human infections. Our objective is also to contribute to the efforts of Institut Pasteur in the field of infectious diseases, by building a pipeline, from sample to microbial identification, able to manage large cohorts of samples. This project is currently supported by the LABEX IBEID and the CITECH, and critically requires a bioIT support, justifying this application. Partners include different hospitals including Necker-Enfants malades University Hospital regarding patients with progressive disease, different IPIN laboratories, as well as INRA and CIRAD regarding animal/arthropod reservoirs.
We are interested in determining the differences in the transcriptome of select developmental stages of the malaria parasite, Plasmodium.
Gene ontology analysis of RNAseq data from uninfected and Leishmania-infected mouse macrophages. Scientific context During the course of cutaneous or visceral disease in humans or experimental animal models, the resolution of leishmanial infections or the control of parasite growth is dependent on appropriate innate and adaptive immune responses developed by the parasitized host. Leishmania largely evades and subverts these responses by its intracellular life style inside the mammalian host, where the parasites develop into amastigotes mainly within macrophages (BMDMs). We have focused our interest in the BMDM inflammasome and the way Leishmania amastigotes interfere or subvert BMDM inflammatory responses. Our recent data are in favor of an absence of stimulation, even a down-regulation of the inflammasome in BMDMs harboring replicating amastigotes at the gene and protein expression levels. To go further on this, we have performed RNAseq experiments on uninfected and infected BMDMs. This project was done at the “Transcriptome and Epigenome” platform and in close collaboration with the C3BI for normalization and statistical analysis procedures. Objective In the present proposal we will perform a deep analysis of the repartition of modulated genes between the different conditions using these RNAseq data. Using C3Bi expertise we will classify known functions of modulated genes into GO aspects i.e. molecular function, cellular component and biological process, visualize gene annotations and perform statistical analyses for the distribution of the annotated genes over the GO hierarchy for the different gene lists analyzed. Hopefully, these analyses will bring us a better understanding of the mechanisms underlying the subversion of BMDM functions in the innate and adaptive immune response to Leishmania infection which is a prerequisite to design novel anti-parasitic intervention strategies targeting the infected host cell rather than the parasite.
We are generating massive amounts of omics data for Leishmania donovani. Anna Zukhova enabled to use the BiNGO module of Cytoskape to perform and visualize our GO enrichment analyses. We would like to continue our collaboration and ask Anna's help to assess the current state of GO annotation of the Leishmania genome and if possible to complete it using domain searches or ortholog mapping from other genomes, including L. major, T. bruce or model organisms such as yeast. We expect that improvement of GO annotation will also us to better reveal enriched GO terms in our datasets and generate testable hypotheses.
Genomic determinants for initiation and length of natural antisense transcripts in a compact eukaryotic genome and phylogenetic analysis of related Entamoeba species
Entamoeba histolytica is a protozoan parasite and an amitochondriate pathogenic amoeba, which causes amoebiasis (dysentery and liver abscess) in humans. In addition to E. histolytica several species infect the human intestine although these do not cause disease and include in most of cases E. dispar and ocassionnally E. moshkovskii. A phylogenetically close Entamoeba, E. invadens infecting snails, is used as cellular model for Entamoeba cyst formation.
Supported by the National Agency for Research (ANR-10-GENM-0011) we developed a project to firstly study the transcriptional landscape of pathogenic E. histolytica. Among the results we discovered that 60% of ORFs present anti-sense RNAs (NATs) that map to the 3‘ end of genes. Their regulation is modified upon environmental changes. The regulation of NATs is basically governed by genomic sequences within the very short intragenic region of the amoeba genome. Secondly, we have started to conduct comparative genomics and transcriptomics approaches to understand phenotypic differences between Entamoeba species, in particular with respect to virulence.
Antimalarial drug resistance in Africa: A comprehensive molecular analysis of the emergence of artemisinin resistant parasites in Africa
We are involved, in collboration with the WHO, in the SaMARA which aims at detecting the emergence of antimalarial drug resistance in Africa. Samples (dried blood spots) are collected from the Nantional Malaria Control Programmes in Africa during clinical efficacy studies. My group at the Institut Pasteur in collaboration with the Institut Cochin (Frédéric Ariey) tested these samples and assessed the proportion of parasites harboring SNPs or CNV associated to antimalarial drug resistance. We have previously demonstrated that mutations in the propeller dommain of a Kelch gene located on the chromosome 13 are strongly predictive of artemsinin resistance. Until last year, artemisinin resistance was confined in South east Asia. Recently, we have detected in African samples a high proportion of mutant parasites. This mutation has never been observed before in South east Asia. To perform comprenhensive genomic analysis, we have sequenced (Illumina) all mutants (=24) and paired wild type samples. Analysis of these sequences (and 400 whole genome sequences from parasites collected in Asia, Africa and America, upload on a dedicated website) should allow to: - define if the mutants have emerged locally or have spread from Asia - define the genetic background of these mutants (are specific alleles facilitated the emergence of K13 mutantions) - describe the genomic profile(s) of these mutants (especially the haplotypes associated to multidrug resistance)
Asymptomatic pathogen carriage in stunted and non-stunted children living in Antananarivo, Madagascar
This project is integrated in the analysis of the gut ecosystem of children implicated in the AFRIBIOTA project, a translational project performed within a consortium of researchers and medical doctors from the Central African Republic, Madagascar, France and Canada (see https://research.pasteur.fr/fr/program_project/the-afribiota-project/). AFRIBIOTA aims at understanding the risk factors and pathophysiological changes underlying chronic child malnutrition as manifested through delayed growth. Within the project submitted, we aim at assessing a possible link between asymptomatic pathogen carriage, gut inflammation and stunted growth of children included in the study site in Antananarivo, Madagascar.
Looking for DNMT (DNA methyltransferase) orthologs in Leishmania which could be potential targets of epigenetic inhibitors active against the parasite.
We tested DNMT and RNMT inhibitors on Leishmania parasites survival and would like to know which could be the potential targets.
African trypanosomes are transmitted by the bite of the tsetse fly and cause the debilitating, and often fatal, neglected tropical disease sleeping sickness, or Human African Trypanosomiasis (HAT). Trypanosoma brucei gambiense, the parasites responsible for 98% of human cases, first reside in the patient blood and skin for months to years before invading the central nervous system, where they cause the neurological symptoms of the disease. HAT is approaching elimination, with the number of cases reported in 2017 dropping to approximately 1,442 from only a dozen African countries. In this context, HAT was included in the WHO roadmap on neglected tropical diseases, with 2020 set as target date for elimination as a public health problem. A secondary goal of zero transmission by 2030 has also been set. These targets have, in part, been encouraged by the success of surveillance efforts that rely on detecting extracellular trypanosomes in human blood. Nevertheless, the reduction in case numbers brings about other challenges. For example, the sensitivity of any diagnostic test diminishes as the disease burden drops, and this is being seen with the serological tests available for HAT. In this context, new highly sensitive and specific diagnostic tools will be required to accurately monitor the occurrence of new cases and the possible emergence of drug-resistant trypanosomes during the elimination phase. Most diagnostic tests currently under development are based on optimization of existing methods that may not combine all the requirements to stand up to the harsh constraints imposed by the elimination phase requirements, especially in terms of sensitivity and specificity. We propose that adapting the recently developed Specific High-sensitivity Enzymatic Reporter unLOCKing (SHERLOCK) technology that combines a CRISPR-Cas system and lateral flow test to trypanosomes will provide the sensitivity and specificity required for a diagnostic test in the elimination and post elimination phases. The SHERLOCK system relies on the collateral effect of Cas13a promiscuous RNA cleavage activity upon target recognition. Combining the collateral effect with pre-amplification of RNAs resulted in rapid RNA detection with attomolar (10^-18 moles/l) sensitivity and single-base mismatch specificity, in a diagnostic setting. This technology has been used to detect specific strains of Zika and Dengue viruses and distinguish pathogenic bacteria in a mixed sample. Furthermore, SHERLOCK reaction reagents can be lyophilized for cold-chain independence and long-term storage and be readily reconstituted on paper for field applications. A lateral flow test for a simple and rapid readout can be easily implemented after a reaction that does not exceed two hours from the sampling step. The first step of this project is to identify promising RNA targets in silico by data mining and multiple alignements of all available transcriptomic data on bloodstream African trypanosomes.
In this project, we aim to identify P. vivax ligands involved in host cell invasion and understand how P. vivax has gained the capacity to infect reticulocytes from Duffy-negative individuals. Our strategy will be based on a 2-step approach by taking full advantage of next-generation sequencing and functional biological analysis (including in vitro invasion assays and infection in humanized mice) and by availing our access to P. vivax isolates from both Duffy-negative and Duffy-positive vivax malaria patients in Madagascar. This strategy should explore and charactere the full repertoire of parasite ligands involved in invasion of human reticulocytes in Malagasy malaria endemic settings where two human populations with distinct Duffy blood group phenotypes (Duffy-negative and Duffy-positive) are frequently exposed to P. vivax. The main objectives of this project are to uncover the molecular basis for the ability of P. vivax to infect reticulocytes from Duffy-positive and Duffy-negative individuals by identifying and defining the role of parasite ligands (including erythrocyte binding proteins (PvEBPs) and reticulocyte binding proteins (PvRBPs)) in mediating invasion and explore the feasibility of targeting combinations of P. vivax invasion related proteins with antibodies to block invasion with high efficiency.
A cost-effective molecular Tool for Strengthening Antimalarial drug Resistance surveillance in Africa (TSARA)
In the TSARA project, we aim at developing and validating a molecular platform (Dual Index Targeted Amplicon Deep Sequencing on Illumina iSeq) and a dedicated bioinformatics pipeline for targeted high throughput sequencing of genetic loci related to antimalarial drug resistance. The iSeq Illumina platform, proposed here, is designed for dual indexing of samples, consisting of a 3’ and 5’ individual barcode, which allow the user to connect every sequence generated to a specific sample (up to 384 samples). The development and the validation of this novel molecular tool will be performed at IP Paris first by using DNA extracted from P. falciparum reference strains (3D7, Dd2 and culture-adapted Cambodian strains) (WP1) and second, by using P. falciparum DBS samples collected from two malaria endemic areas (Central African Republic and Cameroon) (WP2). In the WP3, we will host and train staff from IP Bangui and CP Cameroon to this new approach. Our final objective is that Dual Index Targeted Amplicon Deep Sequencing on iSeq along with minimal bioinformatics infrastructure operated in countries that are endemic for malaria to facilitate routine large-scale surveillance of the emergence of drug resistance and to ensure continued success of the malaria treatment policy.
Paleo(meta)genomics is an emerging and rapidly growing field where most is yet to be done. In most cases, it consists in the analysis of ancient DNA high-throughput sequencing data obtained from archaeological material or historical samples, and the goal is to retrieve and interpret the genomic information from species that from the past (microbial, eukaryotic, etc.) It combines tools borrowed from different fields, such as genomics, computational biology, microbial ecology, phylogenetics, population genetics, etc. However, at the moment there are no well-established tools for the analysis of this type of data. Hence, each lab must develop custom solutions, combining existing tools or developing new ones to meet the goals of their research programs. As a recently established lab, the microbial paleogenomics unit will spend the upcoming months setting up diverse pipelines and analysis tools for the different projects that will be developed in the coming years, many of which have been already used but need to be re-written in an understandable languaje and structure.
A cost-effective molecular Tool for Strengthening Antimalarial drug Resistance surveillance in Africa (TSARA)
In the TSARA project, we aim at developing and validating a molecular platform (Dual Index Targeted Amplicon Deep Sequencing on Illumina iSeq) and a dedicated bioinformatics pipeline for targeted high throughput sequencing of genetic loci related to antimalarial drug resistance. The iSeq Illumina platform, proposed here, is designed for dual indexing of samples, consisting of a 3’ and 5’ individual barcode, which allows the user to connect every sequence generated to a specific sample (up to 384 samples). The development and the validation of this novel molecular tool will be performed at IP Paris first by using DNA extracted from P. falciparum reference strains (3D7, Dd2 and culture-adapted Cambodian strains) (WP1) and second, by using P. falciparum DBS samples collected from two malaria-endemic areas (The central African Republic and Cameroon) (WP2). In the WP3, we will host and train staff from IP Bangui and CP Cameroon to this new approach. Our final objective is that Dual Index Targeted Amplicon Deep Sequencing on iSeq along with minimal bioinformatics infrastructure operated in countries that are endemic for malaria to facilitate routine large-scale surveillance of the emergence of drug resistance and to ensure the continued success of the malaria treatment policy
The LeiSHield-MATI consortium: Investigating genomic adaptation of Leishmania parasites in endemic areas
Leishmania causes devastating human diseases – leishmaniases - representing an important public health problem in the Mediterranean basin and declared as emerging diseases in the EU due to climate change and population displacement. The LeiSHield-MATI consortium will for the first time investigate in an integrative fashion the complex parasite-vector-host interplay in cutaneous leishmaniasis affecting Morocco, Algeria, Tunisia, and Iran (MATI), using field isolates and human clinical samples. The ultimate goal of our project is to identify genetic factors selected during natural infection and to understand how the complex parasite-vector-animal interaction impacts clinical outcome in infected patients. This goal will be achieved through a highly ambitious secondment plan between all partners, and the organization of courses and workshops to train the next generation of scientists generating a long-term impact on the research capacities in endemic areas. Capitalizing on complementary infrastructures of its EU, African and Asian partners and their expertise in molecular parasitology, epidemiology, systems level analyses, bioinformatics, computational biology, immunology, dermatology, field studies, and public health, our project will drive important innovation in clinical research, strengthen capacities in disease endemic regions, inform authorities on control measures, and raise awareness in all partner countries on this emerging EU public health problem. The highly inter-disciplinary and inter-sectorial structure of LeiSHield-MATI, and its powerful integrative and comparative approach is novel in parasitic systems and will drive a unique bio-marker discovery pipeline for the future development of new prognostic and diagnostic tools, as well as novel preventive and therapeutic measures that will ensure long-term collaboration, promote scientific and commercial self-sustainability of its partners, and will have an important impact to improve public health.
Centrosomes are the main microtubule organizing center of eukaryotic cells with critical roles in cell division, polarity, signaling and structure. In most cells, one or both centrioles act as basal body (BB), nucleating microtubules to form cilia or flagella, sensory and motile organelles of vital importance for a wide range of biological functions. Notorious deadly diseases such as cancer, microcephaly and ciliopathies correlate with dysregulation in the number and/or structure of the centrosome/BB. Defects in centriolar proteins also impact cell division and flagellar function of parasitic protists. Notably, T. gondii can assemble flagella during its sexual cycle within the cat’s enteroepithelial tissue, a largely unattainable life stage in vitro. The state of the art of the field points at the centrosome and basal body of apicomplexan and trypanosomatid parasites as potentially rich sources of novel therapeutic targets to fight parasitic diseases. However, their molecular composition and the regulation of their biogenesis remain ill-described. Albeit a number of structural components appear to be conserved between parasitic protozoa and their vertebrate hosts, the absence of conserved homologs of regulatory components, suggests that their biogenesis is likely controlled by divergent triggers of unknown targets. Within the framework of a funded ACIP grant (076-2017), this team pursued the characterization of the centrosome composition in T. gondii, and explored the localization of newly identified principles in T. brucei. This proposal focuses on deciphering the role of the newly identified proteins in the biology of the centrosome in Toxoplasma gondii, as a model for the phylum apicomplexa, and to analyze the role of these conserved proteins in basal body biogenesis and function in Trypanosoma brucei. Based on our preliminary identification of novel centrosomal/basal body components and the powerful tools available in our model organisms, we now propose: 1. To analyze the phylogenetic distribution and functional domains of 20 novel proteins of T. gondii through bioinformatic approaches. 2. To assess the localization of these 20 proteins, and the function and cell cycle dynamics of those localized to the centrosome, in T. gondii. 3. To characterize the function of a protein complex linking the centrosome to nascent daughter cells in T. gondii. 4. To characterize the role of 3 novel T. brucei proteins homologs in basal body biology.
Gene conversion and allelic selection drives L. donovani genomic adaptation in experimental Sand fly infection
Leishmania genomic adaptation during sand fly infection is only poorly understood. In particular, the possibility of allelic selection in a given parasite population inside the insect vector has not been investigated, even though sexual recombination and the possibly of self-sex (selfing) can change allele frequencies and thus may be relevant for parasite transmission and virulence. We investigate this important open question conducting experimental sand fly infection with bona fide amastigotes isolated from infected hamster spleen, and derived promastigotes with different karyotypic profiles. Applying our genome instability pipeline (GIP) on sand fly-recovered parasites revealed a novel form of Leishmania genome instability inside the insect vector relying on gene conversion, which causes haplotype shuffling and likely allows for the selection of beneficial alleles.
We are working on malaria drug discovery. In an attempt to understand the mode of action of epigenetic inhibitors active against Plasmodium falciparum, we culture the parasite under drug pressure to induce drug resistance, along with a control treated in the same conditions with the solvent only. We then clone resistant and control parasite lines and sequence their genomes to compare them to try to understand which gene is responsible for the resistance and thus may constitute the inhibitor's target (through SNPs, amplification of gene copies).
Transcriptional analysis of niche cells in the context of tumour progression in the Drosophila brain
We are interested in the behaviour of healthy cells in the context of tumour growth in the Drosophila brain We want to know the genes changing in healthy cells response to the tumour.