Université PSL



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Diversification of human plasmacytoid predendritic cells in response to a single stimulus
Alculumbre SG, Saint-André V, Di Domizio J, Vargas P, Sirven P, Bost P, Maurin M, Maiuri P, Wery M, Roman MS, Savey L, Touzot M, Terrier B, Saadoun D, Conrad C, Gilliet M, Morillon A, Soumelis V
Nat Immunol. - 19(1) 63-75 - doi: 10.1038/s41590-017-0012-z. - 2018
Innate immune cells adjust to microbial and inflammatory stimuli through a process termed environmental plasticity, which links a given individual stimulus to a unique activated state. Here, we report that activation of human plasmacytoid predendritic cells (pDCs) with a single microbial or cytokine stimulus triggers cell diversification into three stable subpopulations (P1-P3). P1-pDCs (PD-L1+CD80-) displayed a plasmacytoid morphology and specialization for type I interferon production. P3-pDCs (PD-L1-CD80+) adopted a dendritic morphology and adaptive immune functions. P2-pDCs (PD-L1+CD80+) displayed both innate and adaptive functions. Each subpopulation expressed a specific coding- and long-noncoding-RNA signature and was stable after secondary stimulation. P1-pDCs were detected in samples from patients with lupus or psoriasis. pDC diversification was independent of cell divisions or preexisting heterogeneity within steady-state pDCs but was controlled by a TNF autocrine and/or paracrine communication loop. Our findings reveal a novel mechanism for diversity and division of labor in innate immune cells.
In situ targeted activation of an anticancer agent using ultrasound-triggered release of composite droplets
Bezagu M, Clarhaut J, Renoux B, Monti F, Tanter M, Tabeling P6, Cossy J, Couture O, Papot S, Arseniyadis S
- 142 44014 - DOI: 10.1016/j.ejmech.2017.03.057 - 2017
The efficiency of a drug is usually highly dependent on the way it is administered or delivered. As such, targeted-therapy, which requires conceiving drug-delivery vehicles that will change their state from a relatively stable structure with a very slow leak-rate to an unstable structure with a fast release, clearly improves the pharmacokinetics, the absorption, the distribution, the metabolism and the therapeutic index of a given drug. In this context, we have developed a particularly effective double stimuli-responsive drug-delivery method allowing an ultrasound-induced release of a monomethylauristatin E-glucuronide prodrug and its subsequent activation by a β-glucuronidase. This led to an increase of cytotoxicity of about 80% on cancer cells.
Study of the Stability and Hydrophilicity of Plasma‐Modified Microfluidic Materials
Bradley Da Silva Mengxue Zhang Guillaume Schelcher Lea Winter Cédric Guyon Patrick Tabeling Daniel Bonn Michael Tatoulian
- - doi.org/10.1002/ppap.201600034 - 2017
Polymers among new classes of materials such as polydimethylsiloxane (PDMS), cyclic olefin copolymer (COC), Norland optical adhesive (NOA), and THV (fluoropolymer) were evaluated as surface‐modified microfluidic materials, including investigating the incorporation of silica‐like functional groups onto these surfaces. The functionalization of these materials was performed using a hybrid reactor equipped with magnetron sputtering using a silica target and with a PECVD apparatus starting from hexamethyldisiloxane as a chemical precursor. Coated microfluidic materials were then evaluated in terms of wettability, stability, composition, and structure. The deposited coatings were proved to be stable up to 2 month in air and water storage for these materials, with COC providing the
The development and numerical simulation of a plasma microreactor dedicated to chemical synthesis
Mengxue Zhang / Stephanie Ognier / Nadia Touati / Laurent Binet / Christophe Thomas / Patrick Tabeling / Michaël Tatoulian
- - DOI: https://doi.org/10.1515/gps-2016-0086 - 2017
A plasma microreactor dedicated to chemical synthesis has been conceived and developed using soft-lithography techniques. In this study, we propose to use highly reactive species created by the plasma discharge to replace traditionally used chemical initiators. A dielectric barrier discharge plasma was generated under atmospheric pressure and then dispersed into a continuous liquid phase with a T-junction geometry. Injected metal electrodes made it possible for in situ optical observations with an intensified charge-coupled device camera. No signal was detected when analyzing the exhaust liquid by electron spin resonance (ESR) spectroscopy. Numerical simulations confirmed that only low quantities of hydroxyl radicals could diffuse into the liquid phase, giving a concentration of DMPO-OH of 10−6 mol/l, below the detection limit of ESR.
Single-cell deep phenotyping of IgG-secreting cells for high-resolution immune monitoring.
Eyer K, Doineau RCL,Castrillon C, Briseño-Roa L, Menrath V, Mottet G, England P, Godina A, Brient-Litzler E, Nizak C, Jensen A, Griffiths AD, Bibette J, Bruhns P, Baudry J.
Nat Biotechnol. - 35(10) 977-982 - doi: 10.1038/nbt.3964. - 2017
Studies of the dynamics of the antibody-mediated immune response have been hampered by the absence of quantitative, high-throughput systems to analyze individual antibody-secreting cells. Here we describe a simple microfluidic system, DropMap, in which single cells are compartmentalized in tens of thousands of 40-pL droplets and analyzed in two-dimensional droplet arrays using a fluorescence relocation-based immunoassay. Using DropMap, we characterized antibody-secreting cells in mice immunized with tetanus toxoid (TT) over a 7-week protocol, simultaneously analyzing the secretion rate and affinity of IgG from over 0.5 million individual cells enriched from spleen and bone marrow. Immunization resulted in dramatic increases in the range of both single-cell secretion rates and affinities, which spanned at maximum 3 and 4 logs, respectively. We observed differences over time in dynamics of secretion rate and affinity within and between anatomical compartments. This system will not only enable immune monitoring and optimization of immunization and vaccination protocols but also potentiate antibody screening.
Hydrophobization of Silica Nanoparticles in Water: Nanostructure and Response to Drying Stress
Solenn Moro, Caroline Parneix, Bernard Cabane†, Nicolas Sanson, and Jean-Baptiste d’Espinose de Lacaillerie
Langmuir - 33, 19 4709-4719 - DOI: 10.1021/acs.langmuir.6b04505 - 2017
We report on the impact of surface hydrophobization on the structure of aqueous silica dispersions and how this structure resists drying stress. Hydrophilic silica particles were hydrophobized directly in water using a range of organosilane precursors, with a precise control of the grafting density. The resulting nanostructure was precisely analyzed by a combination of small-angle X-ray scattering (SAXS) and cryo-microscopy (cryo-TEM). Then, the dispersion was progressively concentrated by drying, and the evolution of the nanostructures as a function of the grafting density was followed by SAXS. At the fundamental level, because the hydrophobic character of the silica surfaces could be varied continuously through a precise control of the grafting density, we were able to observe how the hydrophobic interactions change particles interactions and aggregates structures. Practically, this opened a new route to tailor the final structure, the residual porosity, and the damp-proof properties of the fully dried silica. For example, regardless of the nature of the hydrophobic precursor, a grafting density of 1 grafter per nm2 optimized the interparticle interactions in solution in view to maximize the residual porosity in the dried material (0.9 cm3/g) and reduced the water uptake to less than 4% in weight compared to the typical value of 13% for hydrophilic particles (at T = 25 °C and relative humidity = 80%).
Interparticle Capillary Forces at a Fluid − Fluid Interface with Strong Polymer-Induced Aging
Stefano Cappelli, Arthur M. de Jon, Jean Baudry, and Menno W. J. Prins
Langmuir - 33 (3) 696–705 - DOI: 10.1021/acs.langmuir.6b03910 - 2017
We report on a measurement of forces between particles adsorbed at a water–oil interface in the presence of an oil-soluble polymer. The cationic polymer interacts electrostatically with the negatively charged particles, thereby modulating the particle contact angle and the magnitude of capillary attraction between the particles. However, polymer adsorption to the interface also generates an increase in the apparent interfacial viscosity over several orders of magnitude in a time span of a few hours. We have designed an experiment in which repeated motion trajectories are measured on pairs of particles. The experiment gives an independent quantification of the interfacial drag coefficient (10–7–10–4 Ns/m) and of the interparticle capillary forces (0.1–10 pN). We observed that the attractive capillary force depends on the amount of polymer in the oil phase and on the particle pair. However, the attraction appears to be independent of the surface rheology, with changes over a wide range of apparent viscosity values due to aging. Given the direction (attraction), the range (∼μm), and the distance dependence (∼1/S5) of the observed interparticle force, we interpret the force as being caused by quadrupolar deformations of the fluid–fluid interface induced by particle surface roughness. The results suggest that capillary forces are equilibrated in the early stages of interface aging and thereafter do not change anymore, even though strong changes in surface rheology still occur. The described experimental approach is powerful for studying dissipative as well as conservative forces of micro- and nanoparticles at fluid–fluid interfaces for systems out of equilibrium.
Controlled production of sub-millimeter liquid core hydrogel capsules for parallelized 3D cell culture
Hugo Doméjean, Mathieu de la Motte Saint Pierre, Anette Funfak, Nicolas Atrux-Tallau, Kevin Alessandri, Pierre Nassoy, Jérôme Bibettea and Nicolas Bremond
Lab. Chip - 17 110-119 - DOI: 10.1039/C6LC00848H - 2017
Liquid core capsules having a hydrogel membrane are becoming a versatile tool for three-dimensional culture of micro-organisms and mammalian cells. Making sub-millimeter capsules at a high rate, via the breakup of a compound jet in air, opens the way to high-throughput screening applications. However, control of the capsule size monodispersity, especially required for quantitative bioassays, was still lacking. Here, we report how the understanding of the underlying hydrodynamic instabilities that occur during the process can lead to calibrated core–shell bioreactors. The requirements are: i) damping the shear layer instability that develops inside the injector arising from the co-annular flow configuration of liquid phases having contrasting viscoelastic properties; ii) controlling the capillary instability of the compound jet by superposing a harmonic perturbation onto the shell flow; iii) avoiding coalescence of drops during jet fragmentation as well as during drop flight towards the gelling bath; iv) ensuring proper engulfment of the compound drops into the gelling bath for building a closed hydrogel shell. We end up with the creation of numerous identical compartments in which cells are able to form multicellular aggregates, namely spheroids. In addition, we implement an intermediate composite hydrogel layer, composed of alginate and collagen, allowing cell adhesion and thus the formation of epithelia or monolayers of cells.
Long-term high-resolution imaging of C. elegans larval development with microfluidics
Keil W, Kutscher LM, Shaham S, Siggia ED
Dev Cell - 10(1) 202-214 - doi: 10.1016/j.devcel.2016.11.022 - 2017
Long-term studies of Caenorhabditis elegans larval development traditionally require tedious manual observations because larvae must move to develop, and existing immobilization techniques either perturb development or are unsuited for young larvae. Here, we present a simple microfluidic device to simultaneously follow development of ten C. elegans larvae at high spatiotemporal resolution from hatching to adulthood (∼3 days). Animals grown in microchambers are periodically immobilized by compression to allow high-quality imaging of even weak fluorescence signals. Using the device, we obtain cell-cycle statistics for C. elegans vulval development, a paradigm for organogenesis. We combine Nomarski and multichannel fluorescence microscopy to study processes such as cell-fate specification, cell death, and transdifferentiation throughout post-embryonic development. Finally, we generate time-lapse movies of complex neural arborization through automated image registration. Our technique opens the door to quantitative analysis of time-dependent phenomena governing cellular behavior during C. elegans larval development.
Information-theoretic analysis of the directional influence between cellular processes
Sourabh Lahiri, Philippe Nghe, Sander J. Tans, Martin Luc Rosinberg, David Lacoste
- 12(11) - https://doi.org/10.1371/journal.pone.0187431 - 2017
Inferring the directionality of interactions between cellular processes is a major challenge in systems biology. Time-lagged correlations allow to discriminate between alternative models, but they still rely on assumed underlying interactions. Here, we use the transfer entropy (TE), an information-theoretic quantity that quantifies the directional influence between fluctuating variables in a model-free way. We present a theoretical approach to compute the transfer entropy, even when the noise has an extrinsic component or in the presence of feedback. We re-analyze the experimental data from Kiviet et al. (2014) where fluctuations in gene expression of metabolic enzymes and growth rate have been measured in single cells of E. coli. We confirm the formerly detected modes between growth and gene expression, while prescribing more stringent conditions on the structure of noise sources. We furthermore point out practical requirements in terms of length of time series and sampling time which must be satisfied in order to infer optimally transfer entropy from times series of fluctuations.

414 publications.