Identification of polarized macrophage subsets in zebrafish

• DOI: 10.7554/elife.07288
• Publication Date: 2015-07-08T11:32:46Z
• Authors: Mai Nguyen-Chi; Béryl Laplace-Builhe; Jana Travnickova; Patricia Luz-Craw...; Gautier Tejedor; Quang Tien Phan; Isabelle Duroux-R...; Jean-Pierre Levraud; Karima Kissa; Georges Lutfalla; Christian Jorgensen; Farida Djouad
• Keywords: 0301 basic medicine; genomic DNA; interleukin 1beta; chemokine receptor CCR2; polymerase chain reaction; enhanced green fluorescent protein; transforming growth factor beta1; animal behavior; confocal microscopy; phenotypic plasticity; fluorescence activated cell sorting; immunology; Animals, Genetically Modified; Genes, Reporter; lymphotoxin; zebra fish; animal; Biology (General); Escherichia coli infection; macrophage function; Escherichia coli Infections; Zebrafish; 0303 health sciences; tumor necrosis factor alpha; Microscopy, Confocal; messenger RNA; Reverse Transcriptase Polymerase Chain Reaction; Q; R; live imaging; Flow Cytometry; reporter gene; unclassified drug; 3. Good health; [SDV] Life Sciences [q-bio]; cytokine release; classification; real time polymerase chain reaction; Medicine; Kaede protein; 570; injury; QH301-705.5; tumor necrosis factor; wound; Science; animal experiment; Molecular Sequence Data; DNA sequence; interleukin 6; macrophage; Real-Time Polymerase Chain Reaction; Article; reverse transcription polymerase chain reaction; 03 medical and health sciences; larva; macrophage activation; gene expression profiling; Animals; controlled study; fluorescence in situ hybridization; photochemical efficiency; protein expression; [SDV.IMM.II] Life Sciences [q-bio]/Immunology/Innate immunity; cell subpopulation; polarization; nonhuman; Tumor Necrosis Factor-alpha; chemokine receptor CXCR4; flow cytometry; Gene Expression Profiling; Macrophages; Sequence Analysis, DNA; zebrafish; microenvironment; transgenic animal; Developmental Biology and Stem Cells; inflammation; molecular genetics; Wounds and Injuries; biosynthesis

While the mammalian macrophage phenotypes have been intensively studied in vitro, the dynamic of their phenotypic polarization has never been investigated in live vertebrates. We used the zebrafish as a live model to identify and trail macrophage subtypes. We generated a transgenic line whose macrophages expressing tumour necrosis factor alpha (tnfa), a key feature of classically activated (M1) macrophages, express fluorescent proteins Tg(mpeg1:mCherryF/tnfa:eGFP-F). Using 4D-confocal microscopy, we showed that both aseptic wounding and Escherichia coli inoculation triggered macrophage recruitment, some of which started to express tnfa. RT-qPCR on Fluorescence Activated Cell Sorting (FACS)-sorted tnfa+ and tnfa− macrophages showed that they, respectively, expressed M1 and alternatively activated (M2) mammalian markers. Fate tracing of tnfa+ macrophages during the time-course of inflammation demonstrated that pro-inflammatory macrophages converted into M2-like phenotype during the resolution step. Our results reveal the diversity and plasticity of zebrafish macrophage subsets and underline the similarities with mammalian macrophages proposing a new system to study macrophage functional dynamic.