Expertise

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

Search by keywords | Search by organisms

Searched keyword : RNA-seq

Related people (2)

Marie-Agnès DILLIES

Group : HEAD - Hub Core

I obtained an engineering degree in Biomedical engineering from Université de Technologie de Compiègne (UTC) in 1989, a master degree in Control of Complex Systems from UTC in 1990, a PhD in Control of Complex Systems from UTC in 1993, a University Degree in Human Genetics from The University of Rennes 1 in 2001 and a master degree in Functional Genomics from University Paris Diderot (Paris 7) in 2002. I worked as a statistician at the Transcriptome and Epigenome Platform from 2002 to 2017, where I was responsible for the statistical analyses of the data and had an important training activity (on the campus and outside). Since 2015 I have been co-head of the Bioinformatics and Biostatistics Hub within the Center of Bioinformatics, Biostatistics and Integrative Biology (C3BI). I am co-director of the Pasteur course Introduction to Data Analysis and co-organiser of the sincellTE summer school (a school dedicated to single cell transcriptome and epigenome data analysis). I am also co-managing the StatOmique group which gathers more than 60 statisticians from France.


Keywords
RNA-seqStatistical inferenceTranscriptomicsBiostatisticsApplication of mathematics in sciencesExploratory data analysisIllumina HiSeqStatistical experiment designSequencing
Organisms

Projects (3)

Violaine SAINT-ANDRÉ

Group : DETACHED - Detached : Labex milieu intérieur

After graduating from Paris VI University with a PhD in Genetics on the “Role of histone protein post-translational modifications in splicing regulation” that I performed in the Epigenetic Regulation unit at the Institut Pasteur, I carried out two post-doctoral experiences. I first worked for three years as a postdoctoral associate of the Whitehead Institute for Biomedical Research/MIT in Cambridge (USA). My main project consisted in the integration of genomic and epigenomic data in order to predict the transcription factors that are potentially at the core of the regulation of the cell-type specific gene expression programs. I then joined the Institut Curie where I deepened my experience in multi-omics data analyses and integration to identify non-coding RNAs involved in cancer progression. I have recently joined the HUB-C3BI of the Institut Pasteur where I am performing high-throughput data integration to better understand biological complexity and contribute to precision medicine development.


Keywords
ATAC-seqChIP-seqEpigenomicsNon coding RNAPathway AnalysisRNA-seqSingle CellSystems BiologyTool DevelopmentTranscriptomicsData integrationGraph theory and analysisCell biology and developmental biology
Organisms
Human
Projects (1)

Related projects (55)

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.



Project status : Closed

A long-term mission for an assigned CIH-embedded bioinformatician to provide bioinformatic support to the CIH community

The Center for Human Immunology (CIH) supports researchers involved in translational research projects by providing access to 16 different cutting edge technologies. Currently, the CIH hosts over 60 scientific projects coming from 8 departments of the Institut Pastuer and 5 external teams. In order to respond to the growing needs of these projects in the area of single cell analysis, the CIH has introduced a significant number of single-cell/single-molecule technologies over the past 2-3 years. These new technologies, such as the Personal Genome Machine (PGM) and Ion Proton sequencers, iSCAN microarray scanner, Nanostring technology for transcriptomics profiling and real-time PCR machine BioMark, give rise to large datasets with high dimensionality. Such trend, in terms of data complexity, is also true for flow cytometry technologies (currently reaching over 20 parameters per cell). The exploration of this data is generally beyond the scope of scientists involved in translational research projects. In order to maximize the research outcomes obtained from the analysis of these rich datasets, and to ensure that the full potential of our technologies can be served to the users of the CIH, we would require a proximity bioinformatics support. A CIH-embedded bioinformatician would: 1) design and implement standard analysis pipelines for each of the data-rich technologies of the CIH; 2) provide regular ‘bioinformatics clinics’ to allow scientists the possibility to customize standard pipelines to their specific needs; 3) run trainings on the ‘R software’ platform and other data analysis tools (such as Qlucore) of interest for the CIH users. The objective would be to empower the users to run exploratory analysis by themselves, and to teach good practices in terms of data management and data analysis.    



Project status : In Progress

Nanotherapeutics for multidrug-resistant tuberculosis

Tuberculosis (TB) still remains a major public health problem with estimated 9 million incident cases and 1.5 million deaths in 2014 (WHO, Global Tuberculosis Report 2015). More worrisome is the emergence of multi drug resistance (MDR), or even extensively resistant (XDR) M. tuberculosis strains worldwide. The standardized treatment of pan-susceptible tuberculosis is the administration of two antibiotics (rifampicin and isoniazid) for six months, accompanied by two additional antibiotics (pyrazinamid and ethambutol) for the first two months. Although very efficacious, this treatment is very demanding due to the duration and the possible side effects. The treatment of MDR-TB is less standardized, with more toxic and poorly tolerated drugs, resulting in lower cure rates. Therefore, we need not only more molecules with antimycobacterial activity, but also, we urgently need new strategies to increase our therapeutic arsenal for treating MDR-TB. Only three new drugs, bedaquiline, delamanid and PA-824 have been tested in phase2/3 clinical trials.

In this context, the european funded project NAREB has been created. It brings together 14 partners from 8 EU Member and Associated States, and it aims to (i) screen different combinations of antibiotic drugs with nano-carriers (lipid, polymeric, biopolymeric) with and without targeting ligands, (ii) coload antibiotics in order to develop innovative therapeutic combination therapies (iii) test in vitro and in vivo the best therapeutic combinations. In particular, we will analyze more in-depth the effect of bedaquilin, new TB drugs and nano-carriers on the host/bacterial transcriptome using RNAseq.



Project status : Closed

Identification of Tac4 mRNA targets

We are interested in the cytoplasmic quality control of gene expression and more especially into the behavior of aberrant peptides which could be generated from non-conform translation events. We are now investigating the role of a Saccharomyces cerevisiae RNA helicase protein that we named Tac4 (for Translation associated Component 4). We showed that this protein is involved in translation. We demonstrated, by sucrose gradient and affinity purification that Tac4 interacts with the ribosome. A first UV cross-linking and cDNA analysis (CRAC) experiment clearly revealed that Tac4 interacts with the 18S rRNA of the 40S ribosomal subunit and we precisely defined the crosslink point. These preliminary results also suggested an enrichment of the 3’-end regions of mRNAs. This implies that Tac4 could not only interact with the small ribosomal subunit but also directly with mRNA. Tac4 is conserved through the evolution and its mammalian homologue is involved in initiation of translation. Therefore, we thought that Tac4 could be associated with the 5’-end rather than with the 3’-end. However, a recent paper from the Rachel Green’s lab showed that translation reinitiation into the 3’-UTR region may occurs when translation termination is affected (Young et al., Cell 2015). The factors and molecular mechanisms implicated in these events are not known. Altogether, our preliminary results suggest that Tac4 is an excellent candidate participating to the unwinding of RNA structure or to the release of some RNA-binding proteins into the 3’-end mRNA. We now would like to 1) confirm that Tac4 preferentially interacts with the 3’-end of mRNA, 2) determine whether Tac4 interacts with a region upstream the Stop codon or in the 3’-UTR of the mRNA, 3) identify the mRNA targets to determine whether Tac4 could have a general role in translation or could only be involved in translation of some specific mRNA.



Project status : Awaiting Publication

Study of the early pathogenesis during Lassa fever in cynomolgus monkeys and its correlation with the outcome

Because of their increasing incidence, dramatic severity, lack of treatment or vaccine, complicated diagnosis, misreading of the pathogenesis, and need for a maximum containment, Viral Hemorrhagic Fevers (VHF) constitute a major public health problem. There is therefore an urgent need to further study VHF to understand the pathogenesis of the severe disease and the host responses involved in their control or in the dramatic damages. Among VHF, Lassa fever (LF) is probably the most worrying one because of its endemicity and the large number of cases. LF is caused by the Old-World arenavirus Lassa virus (LASV). It is endemic to West Africa and is responsible for 300,000 cases and 5,000 to 6,000 deaths each year. We propose here to study the pathogenesis of VHF by using LF in cynomolgus monkeys as a paradigm, with a particular emphasis on the very early events. The viral tropism, pathophysiological mechanisms, and immune responses will be studied during the course of infection, including the incubation period. Powerful approaches will be used to (1) identify early biological markers of infection, to be able to confirm infection and isolate patients; (2) determine the viral tropism and dynamics during the course of infection to understand the natural history of virus into its host. (3) characterize the early pathogenic events that lead to the severe hemorrhagic syndrome to fully understand the pathophysiogenesis of VHF and identify new therapeutic targets. (4) identify the immune responses involved in the control of infection or in the fatal outcome, to reveal the involvement of immunopathological mechanisms and help to design a vaccine approach. This ambitious and unprecedented project will allow to develop therapeutic and prophylactic approaches but also to identify early biological markers of infection and improve the early diagnosis to optimize the management of outbreaks in the field and increase the survival rate in patients.



Project status : In Progress

Characterization of a Salmonella mutant carrying a single amino-acid substitution in the stress sigma factor RpoS



Project status : Closed

Genomic determinants for initiation and length of natural antisense transcripts in a compact eukaryotic genome and phylogenetic analysis of related Entamoeba species



Project status : Closed

Identification of Ago2-bound nuclear transcripts and genomic loci in adult zebrafish neural stem cells

Adult neurogenesis is the process by which adult neural stem cells (NSCs) produce new neuronal and glial cells throughout an animal life. Studies in vertebrates have unveiled the crucial importance of this phenomenon for neural tissue homeostasis and proper brain function. Fundamentally, this process is a balance between maintaining a quiescent NSC pool and recruiting them into the neurogenesis cascade. Using the adult zebrafish anterior brain (telencephalon) as a model, we aim at deciphering the molecular mechanisms governing this balance. We identified a microRNA, miR-9, as a prominent quiescence enforcer. Unexpectedly, miR-9 concentrates into the nucleus of quiescent adult NSCs, together with Argonaute proteins (notably Ago2), effector proteins of microRNAs. This nuclear enrichment of Ago/miR-9 is not observed in embryonic or juvenile fish, being thus a signature of deep adult NSC quiescence. It is also observed in mouse NSCs. We wish to use nuclear miR-9/Ago2 as molecular entry points into the molecular mechanisms controlling this adult-specific deep NSC quiescence state. Within this frame, the present project aims to identify Ago2-bound nuclear targets. Through fractionation experiments, we could detect Ago proteins both in the nuclear soluble and in the chromatin-associated fractions of adult zebrafish NSCs. Thus, we built genetic tools to recover the nuclear Ago2-bound transcripts and genomic loci, ie. using CLIP-seq and DamID approaches, respectively. The enriched transcript sequences will be screened for potential miRNA-binding motifs. Putative genomic targets will be screened, in addition, for specific motifs and for their coincidence with defined functional regions (eg. coding or regulatory). The data will be cross-matched with the transcriptome and proteome of miR-9-positive versus –negative adult NSCs. Together, these data should help elaborate hypotheses on the molecular mode(s) of action of nuclear miR-9/AgAgo2 when controlling adult NSC quiescence.



Project status : Closed

Transcriptomics of Anopheles – Plasmodium vivax interactions towards identification of malaria transmission blocking targets

Despite the worldwide importance of malaria due to Plasmodium vivax, there is currently almost no data on the molecular responses of the Anopheles mosquito vectors to this parasite species. Understanding these responses will contribute to identify relevant strategies to interrupt the transmission of P. vivax by targeting the mosquito vector. Such approaches are urgently needed, as P. vivax is difficult to target on the long term in humans as a consequence of the hypnozoite stage that is responsible for relapses. This project will investigate the molecular response of Anopheles arabiensis, member of the Anopheles gambiae complex, to P. vivax from experimental infections performed in Madagascar where both mosquito and parasite are present. This is a unique situation that will capitalize on the strong knowledge and tools available for An. gambiae sensu lato. The response will be compared to the one triggered by P. falciparum, also present in Madagascar. From mosquitoes infected in a field setting, a transcriptomic (RNAseq) approach will be used to identify common and unique pathways to both parasite species. These analyses will further contribute to identify targets for interrupting transmission of each or both parasites simultaneously. However, a pilot study performed with the PF transcriptomics & epigenomics revealed that the current release of the An. arabiensis genome is poorly annotated. Therefore, to be able to make sens of the RNAseq analyses per se, a strong support from the C3BI Hub for bioinformatics and biostatistics is critical.



Project status : Closed

Role of small non coding RNAs in the adaptive response to oxidative stress in pathogenic Leptospira

Pathogen leptospires are responsible for the zoonotic disease leptospirosis. This neglected but emerging infectious disease has a worldwide distribution and affects people from developing countries, mostly under tropical areas. The clinical manifestations of this infection range from a febrile state to a severe life-threatening form characterized by multiple organ hemorrhages. More than one million cases of leptospirosis are currently reported annually in the word, with 10% of mortality. Leptospira penetrate hosts and rapidly disseminate to target organs (including kidney, liver, lungs) throughout the bloodstream. They are not obligatory intracellular pathogen but they can transiently persist inside macrophages. Due to the difficulty of gene inactivation in pathogen Leptospira, their study is hampered and limited. Thus, their virulence mechanisms and how they survive inside hosts remain largely unknown. During infection, Leptospira are confronted with dramatic adverse environmental changes such as deadly reactive oxygen species (ROS). Defenses against ROS, e.g. peroxidase activity, are crucial for Leptospira virulence. In previous studies, we have identified by RNASeq the cellular factors solicited by Leptospira interrogans to adapt to an oxidative stress and determined the regulons of the two peroxide stress regulators PerR1 and PerR2. We aim now at studying how small non coding RNAs participate in the adaptive response to oxidative stress in pathogen Leptospira. Regulation of any predicted small non coding RNAs will be examined in the RNASeq data we have already obtained.



Project status : Closed

Determination of host response elicited by different Salmonella lifestyles

A number of mammalian cell types are susceptible to Salmonella Typhimurium infection, including epithelial cells, fibroblasts and macrophages. It has recently been demonstrated that Salmonella display specific lifestyles in a host cell type-specific manner, where these lifestyles are remarkable for the subcellular localization and replication rate of Salmonella. During epithelial cells infection, Salmonella are first uptaken by the host cell and being encapsulated in a unique endocytic compartment termed Salmonella-containing vacuole (SCV). Within the SCV, Salmonella could remodel the SCV into a viable replicative niche or rupture the SCV and hyper-replicate in the host cytosol. Salmonella replicate at distinct rates in the two localizations, the Salmonella replication in SCV commences from 5 hours post-infection (pi) and infected host cell harbors less then 10 bacteria at 8h pi. While the cytosolic Salmonella begins replication within the first hour of infection at a rate of 30 minutes per division and accumulates up to over 50 bacteria in the host at 8h pi. To understand how Salmonella achieves the two distinct intracellular lifestyles as well as the pathophysiological impacts of the two lifestyles, the primitive goal of my project is to develop a bacterial-borne fluorescent reporter that clearly depicts the subcellular localization and replication rate of Salmonella. With this multiplex fluorescent reporter, we will set to explore the fundamental biological questions: to determine the immune response of epithelial cells against the two Salmonella lifestyles.



Project status : Declined

Gene expression and its regulation during and after inpatient detoxification of cocaine: a link to relapse?

Cocaine is the most widely used illicit stimulant in Europe1, with a recent increase in use in the French general population. Cocaine addiction (CocAdd) is recognised as a public health priority worldwide, affecting 3% of the US general population, with high burden for individuals and societies1 (4 to 8-fold increase in standardised mortality rates). Clinically, (cocaine) addiction (or substance use disorder) is defined as the compulsive use of a substance causing clinically and functionally significant impairment (health problems, disability, and failure to meet major responsibilities at work, school, or home). These features constitute the basis of diagnostic criteria. There is no approved medication to treat CocAdd, despite significant advances regarding the mechanisms underpinning the neurobiology of chronic cocaine self-administration in rodents. CocAdd is defined as a maladaptive and compulsive reward-seeking behaviour related to cocaine. The loss-of-control over drug use and associated urges (craving) is such that 75-90% people with CocAdd report that they have relapsed within one year after inpatient detoxification. It is thus crucial to develop innovative and precise biomarkers to predict the liability to relapse if we are to develop efficient treatment strategies against this devastating disorder. Relapse is a key player in the chronicity of addiction in general and, as such, is the core therapeutic target of any therapy against addiction . Attached to an ongoing study of the neuroimaging signature of CocAdd relapse, we implemented an auxiliary study to draw blood samples from patients with CocAdd undergoing hospital detoxification and followed for up to three months after, so as to collect genetic material. The 'OBSCOC' protocol thus provides biological samples at entry and 15, 30 and 90 days after. These samples are aimed for characterising the whole RNome, miRNome and ChipSeq profile of these patients, who all provided written informed consent for the genetic study and for extensive clinical and sociodemographic assessment as well. We hypothesised that specific changes of gene expression between time points could either predict increased risk for/precocity of or announce imminent relapse. Thus they could serve, on the longer-term, as biomarkers and/or therapeutic targets.



Project status : In Progress

Identifying subpopulation-specific signatures of tuberculosis persistence for enhanced diagnostics.

Microbes are prone to rapid changes and they can either exploit or countervail their variation in a context-dependent manner. To this purpose, both genetic diversity and non-genetic phenotypic variation exist. However, while the overall mutational evolution occurs over lengthy timescales, epigenetic changes take place on a large scale and more rapidly. Collectively this implies that the diversity we observe is profoundly driven by non-genetic variation. This is particularly relevant for the WHO Priority Pathogen Mycobacterium tuberculosis, whose lack of lateral gene transfer and low mutation rate make phenotypic variation an important means of adaptation to stressful conditions. A few studies, including ours, have begun to explore this phenomenon at the single-cell level in M. tuberculosis in axenic and host conditions, which are technically very challenging. This project is based on the assumption that M. tuberculosis can successfully endure harsh environmental conditions thanks to its phenotypic variation. In our view a better understanding of the drivers of phenotypic variation will improve the design and development of original strategies for tuberculosis control. Here we investigate the physiology of M. tuberculosis at the single-cell and subpopulation scale, striving to demystify the bases of phenotypic diversity and the implications for adaptation and persistence. Previously we examined by real-time imaging a fluorescent reporter of ribosomal expression (rRNA-GFP) as a gauge for cellular activity, and found that M. tuberculosis displays phenotypic heterogeneity under optimal growth conditions, which is enhanced in the host, in long-term stationary phase and upon drug exposure. Remarkably we could also detect subpopulations of quiescent bacilli, whose molecular characteristics have yet to be determined, which is the aim of this project. Here we constructed a dual fluorescent reporter of metabolic activity/quiescence in M. tuberculosis, by using our rRNA-GFP reporter as a background strain, further modified with a red fluorescent marker of cellular quiescence. We carried out snapshot microscopy and single-cell analysis during optimal growth conditions as compared with stressful conditions. We found that the cell-activity marker decreases, whereas the cell-quiescence marker is induced under different host-mimetic conditions. We also observed significant intracellular variation during infection assays. Now we envision carrying out a comprehensive analysis of M. tuberculosis phenotypic variation by RNA sequencing. We aim to reveal the molecular differences between subpopulations of bacilli that exhibit discrete metabolic potential, based on their fluorescence output. We have recreated the most interesting conditions on a bulk scale, and sorted active versus quiescent subpopulations, aiming to compare their transcriptional profiles, and to ultimately identify subpopulation-specific biomarkers of persistence towards more accurate diagnostics.



Project status : Awaiting Publication

Early transcriptional signature of T-cell memory after dengue vaccination

Dengue virus (DENV) induces strong T and B cell responses upon infection. However, there is currently neither vaccine nor specific treatment against DENV, which is spreading worldwide causing 400 million new infections every year, of which 100 million cases are symptomatic, ranging from a self-limiting febrile illness named dengue fever (DF) to more severe life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). One of the major obstacles of dengue vaccine development is the cross-reactivity among antibodies against the different DENV serotypes (designed as DENV1-4) that are 67-75% identical at the amino acid level. Indeed, while a primary infection by one DENV serotype can induce a lifelong immunity against re-infection by the same serotype, subsequent infections by heterologous serotypes increase the risk of developing severe dengue, a phenomenon due to non-neutralizing or sub-neutralizing antibodies and called antibody-dependent enhancement (ADE). To avoid the induction of such enhancing antibodies, and given the identification of CD4+ and CD8+ T cell epitopes from previously dengue virus (DENV)-infected donors, we have designed a minimal DENV antigen (called DENV1-NS, patent EP14305984.8 filled on June 23 2014), which is enriched in conserved and highly antigenic epitopes. Using this minimal DENV1-NS antigen, we have first established in vivo its immunogenicity in transgenic mice expressing HLA class II and class I alleles (with the activation of DENV-specific CD4 and CD8 T cells). We have also shown that a prime-boost DNA immunization of these HLA transgenic mice induces a strong T cell immunity, with a significant protection against DENV1 infection, in the absence of neutralizing or sub-neutralizing anti-DENV antibodies (Roth et al., accepted for publication). Our proposal aims, therefore, to identify early transcriptional signatures correlated with the development of memory CD4 and CD8 T cells in vaccinated animals, which promote enhanced anti-dengue immunity.



Project status : Closed

Defining the differential contributions of CD4+ and CD8+ anti-CD19 CAR T cells to tumor outcome, immune recruitment and toxicity

Gene-modified T cells expressing a chimeric antigen receptor (CAR) targeting the CD19 molecule have demonstrated promising clinical efficacy in the treatment of B cell malignancies. However, the frequent relapses and toxic adverse events such as cytokine release syndrome represent hurdles to the success of CAR T cell therapies. In most clinical settings, CAR T cells are generated from a mixture of autologous CD4+ and CD8+ T cells before being infused into patients. This inter-patient heterogeneity within the composition of CAR T cell products renders the large variety of response efficacy and toxicity difficult to interpret. Using a model of B cell aggressive lymphoma developing in the bone marrow, we investigate the differential contributions of CD4+ and CD8+ anti-CD19 CAR T cells to tumor outcome and changes in the tumor microenvironment. Our first in vivo imaging and flow cytometry results suggest that CD4+ CAR T cells have poor cytotoxic potential compared to CD8+ CAR T cell. On the other hand, CD4+ CAR T cells were largely responsible for the cytokine release syndrome and have a unique role in boosting the accumulation of NK cells at the tumor site. Using single cell RNAseq, we aim to identify the changes in the bone marrow tumor microenvironment induced by CD4+ and CD8+ CAR T cells, focusing on the recruitment of host specific immune cell populations and their activation status. Identifying specific contributions of the CD4+ and CD8+ CAR T cells to immune cell recruitment and tumor outcome would help designing optimal CAR T cell products, with important clinical implications.



Project status : Awaiting Publication

Shigella targeting of human colonic Lamina Propria Mononuclear Cells



Project status : Declined

Modulation of cellular pathways involved in neuropathology of rabies infection

Viruses have evolved powerful countermeasures to evade host innate immunity, which produces immediate, but non-specific, immune response during infection. Among viruses possessing RNA genomes, the order of negative-single-strand viruses (Mononegavirales) encompasses many human and animal pathogens that cause severe disease, including measles virus, mumps virus and rabies virus. Rabies virus is known for its neurotropic retrograde progression from the site of transmission to brain parenchyma, and towards salivary glands, different organs linked through parasympathetic nervous system. In the cases of human infection, the exhibited symptoms such as hallucination, diplopia, hydrophobia, unsteadiness or paralysis all indicate that there is causality between rabies virus infection and dysfunction of neural activity. However, lack of pathological brain lesions observed at the point of autopsy or noncytolytic propagation devoid of apoptosis suggest that rabies virus possesses mechanisms to evade or delay immune responses and cell death at least for the duration of replication and transmission. Even though the details in molecular perspective of these discoveries are well laid out now, how these proteins work in coordination or if there are hidden components which connect them all together leading toward deterioration of neural cells on the benefit of virus is largely unclear. Moreover, considering the complexity of brain cell composition and how important the neighboring cells are to shape one neuron’s specialization and dependency onto others in homeostasis, which result in the astounding heterogeneity of gene expression, an integrated and holistic approach is mandatory to get a fully comprehensive view of the mechanisms involved. Consequently, we performed an RNASeq analysis in human interneuron cells derived from induced pluripotent stem cells and infected by two recombinant rabies viruses (Tha virus, isolated from a dog in Thailand and Th4M, a less pathogenic virus which is mutated on 4 different residues of the M gene; this virus can no longer escape the NF-KB pathway) in order to obtain transcriptome data by comparison with uninfected cells, and to have an overview of the temporal dynamics of the genes expression.



Project status : Closed

Defining the effects of TNF-blockers and IL-17A-inhibitors on immune responses in spondyloarthritis patients, analysis of protein and gene expression signatures

Anti-TNF therapy has proven effective to reduce inflammation and clinical symptoms in SpA, however, the high rate of non-responsiveness (30-40%) to TNFi exposes a substantial fraction of patients to side effects without clinical benefit, and it is still not possible to determine which patients will respond to TNF inhibitors (TNFi) before treatment initiation. The recent introduction of antibodies blocking IL-17A has expanded the therapeutic options for axial SpA (axSpA), as well as psoriasis and psoriatic arthritis. It is therefore important to develop tools to guide treatment decisions for patients affected by SpA and other chronic inflammatory diseases, to optimize clinical care and contain health care costs. This project builds on our recent work performed in collaboration with the Bioinfo Hub, in which we have defined the mechanisms of action of TNF-blockers and identified immune signatures correlating with therapeutic responses to anti-TNF therapy in SpA patients (Menegatti et al., 2020). We have measured whole blood immune responses to microbial and pathway-specific stimuli using TruCulture assays in 20 axSpA patients before or after treatment with IL-17A-inhibitors and 20 patients before and after anti-TNF therapy. Proteins in supernatants have been measured by Olink technology for protein profiling. Gene expression in cell pellets has been analyzed by RNA sequencing at the Biomics platform. A preliminary analysis of the RNA-Seq data has been performed by Etienne Kornobis and Thomas Cokelaer.



Project status : In Progress

Etude des TSS alternatif chez Cryptococcus

Dans les années récentes, l’utilisation de données RNA-Seq nous a permis de ré-annoter le génome des trois souches de références de, respectivement, C. neoformans, C. deneoformans et C. deuterogattii (JANBON et al. 2014; GONZALEZ-HILARION et al. 2016; FERRAREZE et al. 2020). En utilisant des données de TSS-Seq et 3UTR-Seq, nous avons identifié les extrémités de chaque gène codant, ce qui nous a permis de décrire en détail la structure des Transcript Leader (TL) (WALLACE et al. 2020). Les séquences TL chez Cryptococcus contiennent un grand nombre de codons uATG (plus de 10 000) qui ne sont pas utilisées pour coder le protéome de ces levures. Nous avons pu montrer que les ATG « codants » étaient caractérisés par un motif proche de celui identifié par Marylin Kozak en étudiant des cellules de singes dans les années 80 (KOZAK 1986). Chez Cryptococcus, le nombre, la position et le motif associé aux uATG régulent l’expression des gènes. Les motifs associés aux ATG peuvent aussi réguler la diversité protéique et notamment leur adressage dans différentes organelles lorsque deux ATG sont en phase et incluant ou excluant, respectivement une séquence d’adressage. (WALLACE et al. 2020). Lors de cette étude, nous avons identifié un grand nombre de clusters de TSS alternative associés au gènes codant chez Cryptococcus. Leur nombre dépend des conditions de cultures mais par exemple, plus de 16 000 clusters de TSS sont associés aux 6800 gènes codants de C. neoformans quand les cellules sont cultivées à 30°C en phase exponentielle. Ces TSS alternatifs peuvent altérer la taille de la séquence TL mais aussi la séquence N-terminale et donc l’adressage de la protéine codée. Certains d’entre de ces TSS alternatifs sont positionnés au milieu de la partie codante des gènes et contrôlent la transcription de mRNAs dont la fonction est inconnue. Les conditions de culture régulent l’utilisation de ces TSS, certains étant régulés par la température d’autres par la phase de croissance. L’étude de la régulation de l’utilisation des TSS alternatifs et de leurs conséquences sur la biologie de Cryptococcus est un sujet majeur de l’unité. Une partie de cette étude demande l’identification et la description de TSS alternatifs et de leur régulation. Le but est de tester différents modèles et/ou pipelines afin de premierement caratétiser ce qu’est un cluster de TSS type chez C. neoformans puis dans un deuxième temps d’analyser la régulation de leurs usages en fonction des conditions de culture.



Project status : In Progress