title: Phagocytosis of immunoglobulin-coated emulsion droplets.
abstract: Phagocytosis by macrophages represents a fundamental process essential for both immunity and tissue homeostasis. The size of targets to be eliminated ranges from small particles as bacteria to large objects as cancerous or senescent cells. Most of our current quantitative knowledge on phagocytosis is based on the use of solid polymer microparticles as model targets that are well adapted to the study of phagocytosis mechanisms that do not involve any lateral mobility of the ligands, despite the relevance of this parameter in the immunological context. Herein we designed monodisperse, IgG-coated emulsion droplets that are efficiently and specifically internalized by macrophages through in-vitro FcγR-mediated phagocytosis. We show that, contrary to solid polymeric beads, droplet uptake is efficient even for low IgG densities, and is accompagnied by the clustering of the opsonins in the zone of contact with the macrophage during the adhesion step. Beyond the sole interest in the design of the material, our results suggest that lateral mobility of proteins at the interface of a target greatly enhances the phagocytic uptake.
authors.affiliation: Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24 rue Lhomond, F-75005, Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005, Paris, France; CNRS, UMR 8640 PASTEUR, F-75005, Paris, France.
authors.forename: Kalthoum
authors.initials: K
authors.lastname: Ben M'Barek
authors.affiliation: Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24 rue Lhomond, F-75005, Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005, Paris, France; CNRS, UMR 8640 PASTEUR, F-75005, Paris, France.
authors.forename: Diana
authors.initials: D
authors.lastname: Molino
authors.affiliation: Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24 rue Lhomond, F-75005, Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005, Paris, France; CNRS, UMR 8640 PASTEUR, F-75005, Paris, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Quignard
authors.affiliation: Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24 rue Lhomond, F-75005, Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005, Paris, France; CNRS, UMR 8640 PASTEUR, F-75005, Paris, France.
authors.forename: Marie-Aude
authors.initials: MA
authors.lastname: Plamont
authors.affiliation: Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24 rue Lhomond, F-75005, Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005, Paris, France; CNRS, UMR 8640 PASTEUR, F-75005, Paris, France.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Institut Curie, Research Center, Paris, France; Membrane and Cytoskeleton Dynamics, CNRS, UMR 144, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Chavrier
authors.affiliation: Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24 rue Lhomond, F-75005, Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005, Paris, France; CNRS, UMR 8640 PASTEUR, F-75005, Paris, France. Electronic address: jacques.fattaccioli@ens.fr.
authors.forename: Jacques
authors.initials: J
authors.lastname: Fattaccioli
mesh_terms: D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D004655:Emulsions / Q000378:metabolism*; D004705:Endocytosis; D007074:Immunoglobulin G / Q000378:metabolism*; D066292:Lipid Droplets / Q000378:metabolism*; D051379:Mice; D009895:Opsonin Proteins / Q000378:metabolism; D010587:Phagocytosis; D010743:Phospholipids / Q000737:chemistry; D011137:Polystyrenes / Q000378:metabolism; D000067996:RAW 264.7 Cells; D013997:Time Factors
chemical_list: D004655:Emulsions; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D010743:Phospholipids; D011137:Polystyrenes
keywords: Adhesion; Emulsion; Immune response; Immunoglobulin; Interface; Lateral mobility; Macrophage; Microsphere; Particulates