Phagocytosis of immunoglobulin-coated emulsion droplets

M’Barek, Kalthoum Ben; Molino, Diana; Quignard, Sandrine; Plamont, Marie‐Aude; Chen, Yong; Chavrier, Philippe; Fattaccioli, Jacques

doi:10.1016/j.biomaterials.2015.02.030

Cited by 39 publications

(45 citation statements)

References 49 publications

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“…Emulsions are colloidal liquid-liquid metastable suspensions stabilized by a surfactant monolayer 45 that have already shown their biocompatibility and their interest as liquid probes in a biophysical context 46 47 . To fabricate the droplets, we manually shear soybean oil in an aqueous solution of a polymeric surfactant (poloxamer 188) to stabilize the emulsion and a viscosifier (sodium alginate) to increase the viscoelasticity of the continuous phase and ease the fragmentation.…”

Section: Resultsmentioning

confidence: 99%

“…), our method increases the dimensionality of the cell migration analysis: in addition to the measurement of physical parameters such as speed or directionality, using droplets as sensors allows measuring the mechanical stress that cells exert while migrating, along to probing the invasiveness of immune cells in a crowded confinement, and exploring by fluorescent microscopy the molecular machinery necessary for generating such stress. Moreover, the possibility to functionalize the interface of the droplets with adhesive molecules or proteins 46 68 would make possible to decipher the interplay between adhesion on the obstacles and migration.…”

Section: Discussionmentioning

confidence: 99%

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On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

Molino

Quignard

Gruget³

et al. 2016

Sci Rep

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The ability of immune cells to migrate within narrow and crowded spaces is a critical feature involved in various physiological processes from immune response to metastasis. Several in-vitro techniques have been developed so far to study the behaviour of migrating cells, the most recent being based on the fabrication of microchannels within which cells move. To address the question of the mechanical stress a cell is able to produce during the encounter of an obstacle while migrating, we developed a hybrid microchip made of parallel PDMS channels in which oil droplets are sparsely distributed and serve as deformable obstacles. We thus show that cells strongly deform droplets while passing them. Then, we show that the microdevice can be used to study the influence of drugs on migration at the population level. Finally, we describe a quantitative analysis method of the droplet deformation that allows measuring in real-time the mechanical stress exerted by a single cell. The method presented herein thus constitutes a powerful analytical tool for cell migration studies under confinement.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

Molino

Quignard

Gruget³

et al. 2016

Sci Rep

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“…PI was defined as the mean over the different repetitions of the total number of internalised oocysts divided by the total number of macrophage cells, i.e. either hosting an oocyst or not 49 .…”

Section: Methodsmentioning

confidence: 99%

Macrophages facilitate the excystation and differentiation of Toxoplasma gondii sporozoites into tachyzoites following oocyst internalisation

Freppel

Puech

Ferguson

et al. 2016

Sci Rep

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Toxoplasma gondii is a common parasite of humans and animals, which is transmitted via oocysts in cat faeces or tissue cysts in contaminated meat. The robust oocyst and sporocyst walls protect the infective sporozoites from deleterious external attacks including disinfectants. Upon oocyst acquisition, these walls lose their integrity to let the sporozoites excyst and invade host cells following a process that remains poorly understood. Given the resistance of the oocyst wall to digestive enzymes and the ability of oocysts to cause parenteral infections, the present study investigated the possible contribution of macrophages in supporting sporozoite excystation following oocyst internalisation. By using single cell micromanipulations, real-time and time-point imaging techniques, we demonstrated that RAW macrophages could interact rapidly with oocysts and engulfed them by remodelling of their actin cytoskeleton. Internalised oocysts were associated to macrophage acidic compartments and showed evidences of wall disruption. Sporozoites were observed in macrophages containing oocyst remnants or in new macrophages, giving rise to dividing tachyzoites. All together, these results highlight an unexpected role of phagocytic cells in processing T. gondii oocysts, in line with non-classical routes of infection, and open new perspectives to identify chemical factors that lead to oocyst wall disruption under physiological conditions.

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“…We have developed a semi-automatic method for the quantitation of phagocytosis by adherent or semiadherent phagocytes ingesting various phagocytic probes such as polystyrene beads [34] or lipid droplets [35]. RAW 264.7 murine macrophages [36] were used as the model cell line; and we focused our study on the FcγR-mediated phagocytosis of IgG-coated fluid and solid microparticles, lipid droplets [35] and polystyrene particles [34], respectively.…”

Section: Resultsmentioning

confidence: 99%

A multiparametric, quantitative and high-throughput assay to quantify the influence of target size on phagocytic uptake

Montel

Pinon

Fattaccioli

2018

Preprint

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Phagocytosis by macrophages represents a fundamental process essential for both immunity and tissue homeostasis. It consists in the uptake of pathogenic or cellular targets larger than 0.5µm. For the biggest particles, the phagocytic process involves a massive reorganization of membrane and actin cytoskeleton as well as an important intracellular deformation, all in a matter of minutes. The study of the role of the size of objects in their phagocytosis has lead to contradictory results in the last decades.We designed a method using confocal microscopy, automated image analysis and databases for fast quantitative analysis of phagocytosis assays. It yields comprehensive data on the cells and targets geometric and fluorescence intensity parameters, automatically discriminates internalized from external targets, and stores the relationship between a cell and the targets it has engulfed. We used two types of targets, solid polystyrene beads and liquid lipid droplets, to investigate the influence of size on the phagocytic uptake of macrophages. The method made it possible, not only to perform phagocytic assays with functionalized droplets and beads of different sizes, but to use polydisperse particles to further our understanding of the role of size in phagocytosis.The use of monodisperse and polydisperse objects shows that while smaller monodisperse objects are internalized in greater numbers, objects of different sizes presented simultaneously are internalized without preferred size. Throughout results, the total surface engulfed by the cell appeared to be the main factor limiting the uptake of particles, regardless of their nature or size. A meta-analysis of the literature reveals that this dependence in surface is consistently conserved throughout cell types, targets' nature or activated receptors.

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Phagocytosis of immunoglobulin-coated emulsion droplets

Cited by 39 publications

References 49 publications

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

Macrophages facilitate the excystation and differentiation of Toxoplasma gondii sporozoites into tachyzoites following oocyst internalisation

A multiparametric, quantitative and high-throughput assay to quantify the influence of target size on phagocytic uptake

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