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.

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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.

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.  

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.

I would like to retrieve all HMT and HDM in Leishmania

Looking for DNMT (DNA methyltransferase) orthologs in Leishmania which could be potential targets of epigenetic inhibitors active against the parasite.

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.

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.

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...).

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.

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