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Team Publications
Exosomes and tumor growth
Year of publication 2016
Dorian Obino, Francesca Farina, Odile Malbec, Pablo J Sáez, Mathieu Maurin, Jérémie Gaillard,
Florent Dingli, Damarys Loew, Alexis Gautreau, Maria-Isabel Yuseff, Laurent Blanchoin, Manuel
Théry, Ana-Maria Lennon-Duménil (2016 Mar 19)
Actin nucleation at the centrosome controls lymphocyte polarity.
Nature communications : 10969 : DOI : 10.1038/ncomms10969
Summary
Cell polarity is required for the functional specialization of many cell types including
lymphocytes. A hallmark of cell polarity is the reorientation of the centrosome that allows
repositioning of organelles and vesicles in an asymmetric fashion. The mechanisms
underlying centrosome polarization are not fully understood. Here we found that in resting
lymphocytes, centrosome-associated Arp2/3 locally nucleates F-actin, which is needed for
centrosome tethering to the nucleus via the LINC complex. Upon lymphocyte activation,
Arp2/3 is partially depleted from the centrosome as a result of its recruitment to the immune
synapse. This leads to a reduction in F-actin nucleation at the centrosome and thereby allows
its detachment from the nucleus and polarization to the synapse. Therefore, F-actin
nucleation at the centrosome-regulated by the availability of the Arp2/3 complex-determines
its capacity to polarize in response to external stimuli.
Mercedes Tkach, Clotilde Théry (2016 Mar 10)
Communication by Extracellular Vesicles: Where We Are and Where We Need to
Go.
Cell : 1226-32 : DOI : 10.1016/j.cell.2016.01.043
Summary
In multicellular organisms, distant cells can exchange information by sending out signals
composed of single molecules or, as increasingly exemplified in the literature, via complex
packets stuffed with a selection of proteins, lipids, and nucleic acids, called extracellular
vesicles (EVs; also known as exosomes and microvesicles, among other names). This Review
covers some of the most striking functions described for EV secretion but also presents the
limitations on our knowledge of their physiological roles. While there are initial indications
that EV-mediated pathways operate in vivo, the actual nature of the EVs involved in these
effects still needs to be clarified. Here, we focus on the context of tumor cells and their
microenvironment, but similar results and challenges apply to all patho/physiological
systems in which EV-mediated communication is proposed to take place.
Joanna Kowal, Guillaume Arras, Marina Colombo, Mabel Jouve, Jakob Paul Morath, Bjarke PrimdalBengtson, Florent Dingli, Damarys Loew, Mercedes Tkach, Clotilde Théry (2016 Feb 8)
INSTITUT CURIE, 20 rue d’Ulm, 75248 Paris Cedex 05, France | 1
Team Publications
Exosomes and tumor growth
Proteomic comparison defines novel markers to characterize heterogeneous
populations of extracellular vesicle subtypes.
PNAS : 113: E968-977 : DOI : 10.1073/pnas.1521230113
Summary
Extracellular vesicles (EVs) have become the focus of rising interest because of their
numerous functions in physiology and pathology. Cells release heterogeneous vesicles of
different sizes and intracellular origins, including small EVs formed inside endosomal
compartments (i.e., exosomes) and EVs of various sizes budding from the plasma
membrane. Specific markers for the analysis and isolation of different EV populations are
missing, imposing important limitations to understanding EV functions. Here, EVs from
human dendritic cells were first separated by their sedimentation speed, and then either by
their behavior upon upward floatation into iodixanol gradients or by immuno-isolation.
Extensive quantitative proteomic analysis allowing comparison of the isolated populations
showed that several classically used exosome markers, like major histocompatibility
complex, flotillin, and heat-shock 70-kDa proteins, are similarly present in all EVs. We
identified proteins specifically enriched in small EVs, and define a set of five protein
categories displaying different relative abundance in distinct EV populations. We
demonstrate the presence of exosomal and nonexosomal subpopulations within small EVs,
and propose their differential separation by immuno-isolation using either CD63, CD81, or
CD9. Our work thus provides guidelines to define subtypes of EVs for future functional
studies.
Thomas Lener, Mario Gimona, Ludwig Aigner, Verena Börger, Edit Buzas, Giovanni Camussi,
Nathalie Chaput, Devasis Chatterjee, Felipe A Court, Hernando A Del Portillo, Lorraine O'Driscoll,
Stefano Fais, Juan M Falcon-Perez, Ursula Felderhoff-Mueser, Lorenzo Fraile, Yong Song Gho,
André Görgens, Ramesh C Gupta, An Hendrix, Dirk M Hermann, Andrew F Hill, Fred Hochberg,
Peter A Horn, Dominique de Kleijn, Lambros Kordelas, Boris W Kramer, Eva-Maria Krämer-Albers,
Sandra Laner-Plamberger, Saara Laitinen, Tommaso Leonardi, Magdalena J Lorenowicz, Sai Kiang
Lim, Jan Lötvall, Casey A Maguire, Antonio Marcilla, Irina Nazarenko, Takahiro Ochiya, Tushar
Patel, Shona Pedersen, Gabriella Pocsfalvi, Stefano Pluchino, Peter Quesenberry, Ilona G Reischl,
Francisco J Rivera, Ralf Sanzenbacher, Katharina Schallmoser, Ineke Slaper-Cortenbach, Dirk
Strunk, Torsten Tonn, Pieter Vader, Bas W M van Balkom, Marca Wauben, Samir El Andaloussi,
Clotilde Théry, Eva Rohde, Bernd Giebel (2016 Jan 5)
Applying extracellular vesicles based therapeutics in clinical trials – an ISEV
position paper.
Journal of extracellular vesicles : 30087 : DOI : 10.3402/jev.v4.30087
Summary
Extracellular vesicles (EVs), such as exosomes and microvesicles, are released by different
cell types and participate in physiological and pathophysiological processes. EVs mediate
INSTITUT CURIE, 20 rue d’Ulm, 75248 Paris Cedex 05, France | 2
Team Publications
Exosomes and tumor growth
intercellular communication as cell-derived extracellular signalling organelles that transmit
specific information from their cell of origin to their target cells. As a result of these
properties, EVs of defined cell types may serve as novel tools for various therapeutic
approaches, including (a) anti-tumour therapy, (b) pathogen vaccination, (c) immunemodulatory and regenerative therapies and (d) drug delivery. The translation of EVs into
clinical therapies requires the categorization of EV-based therapeutics in compliance with
existing regulatory frameworks. As the classification defines subsequent requirements for
manufacturing, quality control and clinical investigation, it is of major importance to define
whether EVs are considered the active drug components or primarily serve as drug delivery
vehicles. For an effective and particularly safe translation of EV-based therapies into clinical
practice, a high level of cooperation between researchers, clinicians and competent
authorities is essential. In this position statement, basic and clinical scientists, as members
of the International Society for Extracellular Vesicles (ISEV) and of the European Cooperation
in Science and Technology (COST) program of the European Union, namely European
Network on Microvesicles and Exosomes in Health and Disease (ME-HaD), summarize recent
developments and the current knowledge of EV-based therapies. Aspects of safety and
regulatory requirements that must be considered for pharmaceutical manufacturing and
clinical application are highlighted. Production and quality control processes are discussed.
Strategies to promote the therapeutic application of EVs in future clinical studies are
addressed.
INSTITUT CURIE, 20 rue d’Ulm, 75248 Paris Cedex 05, France | 3