June 2017
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Lundi 11h00
Amphi Pasteur
Séminaire Externe |
“ Encoding more than memories in the hippocampus ” |
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Dr. Baptiste JAEGER (Brain Research Institut, Université de Zurich - Suisse) Contact : thierry.walzer@inserm.fr
The hippocampus is a brain region critical for learning and memory. Typically, behavioral stimulations - such as exposure to a novel environment (NE) - trigger neuronal activation and subsequent memory encoding in the hippocampus. We combined flow cytometry and single nucleus RNA sequencing of activated hippocampal neurons following NE exposure, to dissect the molecular changes at the basis of memory formation. Our results demonstrate that activity-induced transcriptional changes select the components of the neuronal network that are ultimately involved in the encoding and retrieval of memories. Using our extensive characterization of the neuronal population encoding NE as the gold-standard mechanism of memory formation, we are now exploring the processing of other types of natural stimulations. In particular, we aim to uncover how the brain processes peripheral changes in immune homeostasis and feeds back on the immune system.
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Lundi 11h00
Salle Condorcet
Séminaire Externe |
« Toward understanding how biological clocks drive sleep » | |
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Steven BROWN (University of Zurich)
Host: Kiran Padmanabhan .
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Lundi 11h00
Salle des Thèses CRC
Séminaire Externe
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« Physical nature of nuclear subcompartments: hints from single molecule tracking in living cells » | |
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Angela TADDEI (Institut Curie, Paris) . |
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Mardi 11h00
Amphi Pasteur
Forum Infectiologie |
“ Novel restriction factors targeting HIV-1 dependencies ” | |
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Dr. Franck KIRCHHOFF (Institut of Molecular Virology, Ulm University Medical Center, Ulm– RFA)
Contact : andrea.cimarelli@ens-lyon.fr
HIV, the causative agent of AIDS, has a complex evolutionary history involving several cross-species transmissions and recombination events as well as changes in the repertoire and function of its accessory genes. Understanding the factors and adaptations required for the spread of HIV in the human population provides key insights into innate defence mechanisms and prerequisites for the emergence of the AIDS pandemic. Here, I will first briefly summarize some of our current knowledge on the function of antiviral restriction factors and their viral antagonists, i.e. the accessory viral factors Vpr, Vpx, Vpu and Nef. Next, I will discuss viral features and adaptations preceding the AIDS pandemic. Finally, I will present examples for novel interferon-inducible antiviral factors that modulate the activity of virus-dependency factors rather than targeting the virus directly. Altogether, it is becoming evident that the mechanisms of viral restriction as well as viral countermeasures are even more complex and intertwined than anticipated, and apparently still play relevant roles in the spread of HIV/AIDS.
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Lundi 11h00
Salle Condorcet
Séminaire externe
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« Early land plant evolution» | |
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Stefan RENSING (University of Marburg, RFA)
Host: Yoan Coudert .
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Mardi 11h00
Salle des Thèses CRC
Séminaire externe |
“ The dialogue between conventional T cells and Intestinal Epithelial Cells ” | |
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Dr. Saidi HOMA SOUDJA (CRCL)
Contact : henri.gruffat@ens-lyon.fr
Dysregulated immune responses against commensal bacteria have been associated to inflammatory bowel disease (IBD). Among immune cells, the activation of CD8ab T cells correlates with the worse experiences of IBDs in human patients. Thus, deciphering what regulate CD8ab T cell activation within the intestine is a major challenge (1). In the gut, intestinal epithelial cells (IECs) establish a link between commensal bacteria and mucosal immune system, and particular conventional T cells. IECs are equipped with innate sensor machineries such as Toll Like Receptors (TLRs). IECs could also express the antigen processing machinery such as the immunoproteasome. As a result, IECs are able to efficiently sense the tremendous quantity of microbes hosted in the gut. It is a constant challenge to control IEC reactivity to commensal bacteria and avoid inappropriate immune reaction and IBD development. However, the mechanisms by which intestinal epithelial cell responses to microbiota are tuned remain elusive (2). Globally, we are deciphering the cues of the dialogue between conventional T cells and intestinal epithelial cells in homeostatic condition or in pathological settings. |
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Mercredi 13h30
Amphithéâtre Mérieux
Plénière Celphedia |
«Le sexe, une variable à ne pas négliger : Implication pour la prise en compte de la règle des 3R en expérimentation animale» | |
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Inscriptions, informations pratiques, liste des intervenants : https://www.sfr-biosciences.fr/animation/actualites/Celphedia_20-11-19 Le but de ces conférences est de discuter du biais expérimental encore très souvent constaté dans les protocoles de recherche, dû au fait que le sexe n'est pas pris en compte comme un paramètre expérimental en tant que tel. Quelle est l'ampleur de ce biais expérimental, quelles en sont les conséquences ? Éviter ce biais dans les protocoles en expérimentation animale ne permettrait-il pas de mieux exploiter les données expérimentales ? Ce sont ces questions que nous discuterons le 20 novembre, avec des exemples de dimorphisme sexuel non attendu, un exposé sur l'analyse multiparamétrique des données , et un éclairage philosophique de l'importance de raffiner la conception des protocoles. Ces conférences, prévues sur l'après midi du 20 novembre, de 13h30 à 18h, sont ouvertes à tous, sur inscription gratuite, obligatoire. Au plaisir de vous retrouver le 20 novembre, |
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Vendredi 11h00
Salle des Thèses CRC
Séminaire externe |
« Managing sequences that stall replication » | |
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Julian E. SALE (MRC Laboratory of Molecular Biology, Cambridge) The ability of certain DNA sequences to form secondary structures means that DNA itself can pose on of the most potent barriers to its own replication. By harnessing the fact that impediments to processive replication can lead to local, heritable loss of epigenetic information, we are able to monitor episodes of in vivo replication pausing at defined sequences, for example those able to form G-quadruplexes and triplexes, with exquisite sensitivity (Schiavone et al.,2014; Schiavone et al., 2016; Guilbaud et al., 2017). Our recent work suggests that even short sequences with structureforming potential that were previously not thought to impede replication actually do cause transient polymerase stalling (Šviković et al., 2019). My talk will focus on the mechanisms that ensure replication through these sequences, preventing more deleterious genetic consequences. I will also discuss unpublished data exploring the relationship between sequence, structure formation and the response of a model polymerase. I will show how the response of a polymerase in a simple primer extension assay can make predictions about the structure that a given sequence forms and that this correlates with the extent to which the sequence is maintained or mutated in the genome during evolution. The data suggest how relatively simple replication parameters may determine the genome wide distribution and stability of short tandem repeats. |
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Lundi 11h00
Salle IBCP Conf
Séminaire Externe |
“ Structures and transitions of the serotonin 5-HT3 receptor ” | |
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Hugues NURY (IBS Grenoble) Invited by S. Ravaud
The serotonin 5-HT3 receptor is a pentameric ligand-gated ion channel. It belongs to a large family of receptors that transduce signals across the plasma membrane: upon binding of neurotransmitter molecules to extracellular sites, the receptors undergo complex conformational transitions, which result in transient opening of a pore permeable to ions. 5-HT3 receptors are therapeutic targets for emesis and nausea, irritable bowel syndrome and depression. I will present structures of the 5-HT3 receptor obtained by crystallography or cryo-electron microscopy. The structures, obtained in complex with inhibitors or agonists, represent snapshots in different states: inhibited, pre-active, active. Together with molecular dynamics simulations and functional recordings, they reveal the molecular mechanism of the fast neurotransmission mediated by 5HT3 receptors. |
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Mardi 10h30 Amphithéatre de la Rotonde, INSA campus de la Doua (Villeurbanne)
Conférence EvoLyon |
“ http://evolyon.universite-lyon.fr/” | |
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EvoLyon
La publication par Darwin de "L’origine des espèces" en 1859 a marqué un tournant majeur dans l’histoire des sciences. Au cours du XXème siècle, grâce aux travaux scientifiques dans les domaines les plus divers (génétique moléculaire, écologie des populations, paléontologie, phylogénie, biomathématiques, etc.), notre connaissance de l’histoire et notre compréhension des processus de l’évolution ont considérablement progressé. Ces connaissances constituent le socle sur lequel repose toute la biologie puisque – comme l’a si bien formulé Dobzhansky – "en biologie, rien n’a de sens si ce n’est à la lumière de l’évolution". Plus que jamais, l’évolution du monde vivant est au cœur de nombreux axes de recherches, dont beaucoup dépassent largement le cadre strict des sciences biologiques (sciences de l’homme et de la société, linguistique, philosophie, ...). |
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Mardi 11h00
Amphi Pasteur
Séminaire Externe |
“ Long-term lineage tracing of neonatal B cells in health and disease ” | |
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Pr. Joan YUAN (Lund University – Division of molecular hematology Lund - SWEDEN)
Contact : thierry.defrance@inserm.fr
A wave of long-lived B cells enter the B cell lineage shortly after birth. These early life derived B cells are unevenly scattered across different anatomical locations and are often tissue resident. Their selection into the neonatal B cell repertoire occurs under relaxed tolerance constraints in a Lin28b dependent Fashion (1). Our findings reveal a new way of stratifying the adult B cell compartment, based on cellular turnover, with important implications in health and disease
(1) Vanhee et al. Lin28b controls a neonatal to adult switch in B cell positive selection. 2019, Science Immunology |
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Jeudi & Vendredi 10h30 Délégation Régionale CNRS Workshop régional Microbiome |
“ https://microbiome.sciencesconf.org/” | |
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L'inscription est gratuite mais obligatoire (date limite : 17 novembre 2019) Le workshop régional 'Microbiome' aura lieu les 28 et 29 novembre 2019 à la délégation régionale du CNRS à Villeurbanne. Trois thématiques principales seront développées : Nous aurons le plaisir d'écouter des scientifiques à la pointe de ces recherches (Tobias Engl - Mainz (Allemagne), Estelle Grasset - Göteborg (Suède), Laure Ségurel - Paris) et des scientifiques locaux sur les trois thématiques. |
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