A crucial early wound response is the recruitment of inflammatory cells drawn by danger cues released damaged tissue. Hydrogen peroxide (H2O2) has recently been identified as earliest attractant in Drosophila embryos and zebrafish larvae [1Moreira S. Stramer B. Evans I. Wood W. Martin P. Prioritization competing damage developmental signals migrating macrophages embryo.Curr. Biol. 2010; 20: 464-470Abstract Full Text PDF PubMed Scopus (155) Google Scholar, 2Niethammer Grabher C. Look A.T....

Macrophages are multifunctional cells that perform diverse roles in health and disease. Emerging evidence has suggested these innate immune might also be capable of developing immunological memory, a trait previously associated with the adaptive system alone. While recent studies have focused on dramatic macrophage reprogramming follows infection protects against secondary microbial attack, can macrophages develop memory response to other cues? Here, we show apoptotic corpse engulfment by...

Drosophila melanogaster macrophages are highly migratory cells that lend themselves beautifully to high resolution in vivo imaging experiments. By expressing fluorescent probes reveal actin and microtubules, we can observe the dynamic interplay of these two cytoskeletal networks as migrate interact with one another within a living organism. We show before an episode persistent motility, whether responding developmental guidance or wound cues, assemble polarized array microtubules bundle into...

Drosophila phagocytes participate in development and immune responses through their abilities to perform phagocytosis and/or secrete extra-cellular matrix components, antimicrobial peptides, clotting factors signalling molecules. However, our knowledge of functional impact on host resistance infection is limited. To address this, we have used a genetic cell ablation strategy generate individuals lacking phagocytes. Our results highlight the essential contribution embryonic including central...

Translation of hundreds small ORFs (smORFs) less than 100 amino acids has recently been revealed in vertebrates and Drosophila. Some these peptides have essential conserved cellular functions. In Drosophila, we predicted a particular smORF class encoding ~80 aa hydrophobic peptides, which may function membranes cell organelles. Here, characterise hemotin, gene an 88aa transmembrane peptide localised to early endosomes Drosophila macrophages. hemotin regulates endosomal maturation during...

Tissue damage leads to a robust and rapid inflammatory response whereby leukocytes are actively drawn toward the wound. Hydrogen peroxide (H2O2) has been shown be an immediate signal essential for recruitment of these blood cells wound sites in both Drosophila vertebrates [1Niethammer P. Grabher C. Look A.T. Mitchison T.J. A tissue-scale gradient hydrogen mediates detection zebrafish.Nature. 2009; 459: 996-999Crossref PubMed Scopus (1128) Google Scholar, 2Moreira S. Stramer B. Evans I. Wood...

Drosophila embryos are well studied developmental microcosms that have been used extensively as models for early development and more recently wound repair. Here we extend this work by looking at model systems following bacterial infection in real time. We examine the behaviour of injected pathogenic (Photorhabdus asymbiotica) non-pathogenic (Escherichia coli) bacteria their interaction with embryonic hemocytes using time-lapse confocal microscopy. find both recognise phagocytose wild type,...

Actin regulators facilitate cell migration by controlling protrusion architecture and dynamics. As the behavior of individual actin becomes clear, we must address why cells require multiple with similar functions how they cooperate to create diverse protrusions. We characterized Diaphanous (Dia) Enabled (Ena) as a model, using complementary approaches: culture, biophysical analysis, Drosophila morphogenesis. found that Dia Ena have distinct biochemical properties contribute different...

Macrophages are responsible for diverse and fundamental functions in vertebrates. Drosophila blood cells (haemocytes) dominated by bearing a striking homology to vertebrate macrophages (plasmatocytes). The importance of haemocytes has been demonstrated previously, with immune developmental phenotypes observed upon haemocyte ablation. Here we show that can increase Hml-positive cell numbers using constitutively-active form ras ablate the pro-apoptotic transgene bax. However, adults, compared...

During embryonic development, Drosophila macrophages (haemocytes) undergo a series of stereotypical migrations to disperse throughout the embryo. One major migratory route is along ventral nerve cord (VNC), where haemocytes are required for correct development this tissue. We show, first time, that reciprocal relationship exists between and VNC defects in prevent haemocyte migration structure. Using live imaging, we demonstrate axonal guidance cue Slit its receptor Robo both migration, but...

Vertebrate macrophages are a highly heterogeneous cell population, but while Drosophila blood is dominated by macrophage-like lineage (plasmatocytes), until very recently these cells were considered to represent homogeneous population. Here, we present our identification of enhancer elements labelling plasmatocyte subpopulations, which vary in abundance across development. These subpopulations exhibit functional differences compared the overall including more potent injury responses and...

SUMMARY It is seldom the primary tumour that proves fatal in cancer, with metastasis fundamental pathological process for disease progression. Upregulation of Mena, a member evolutionarily conserved Ena/VASP family actin cytoskeletal regulators, promotes and invasive motility breast cancer cells vivo. To complement vitro studies function fibroblasts, we manipulated levels Ena, Drosophila homologue migrating embryonic macrophages (haemocytes). Consistent data from fibroblasts vitro, Ena...

Throughout embryonic development, macrophages not only constitute the first line of defense against infection but also help to sculpt organs and tissues embryo by removing dead cells secreting extracellular matrix components. Key their function is ability migrate disperse throughout embryo. Yet despite these important developmental functions, little known about molecular mechanisms underlying macrophage migration in vivo. Integrins are key regulators many adult responses, role remains poorly...

Macrophages encounter and clear apoptotic cells during normal development homeostasis, including at numerous sites of pathology. Clearance has been intensively studied, but the effects macrophage–apoptotic cell interactions on macrophage behaviour are poorly understood. Using Drosophila embryos, we have exploited ease manipulating death clearance in this model to identify that loss receptor Six-microns-under (Simu) leads perturbation migration inflammatory responses via pathological levels...

Many studies address cell migration using in vitro methods, whereas the physiologically relevant environment is that of organism itself. Here we present a protocol for mounting Drosophila melanogaster embryos and subsequent live imaging fluorescently labeled hemocytes, embryonic macrophages this organism. Using Gal4-uas system1 drive expression variety genetically encoded, tagged markers hemocytes to follow their developmental dispersal throughout embryo. Following collection at desired...

The actin cytoskeleton is the engine that powers inflammatory chemotaxis of immune cells to sites tissue damage or infection. Here we combine genetics with live, in vivo imaging investigate how cytoskeletal rearrangements drive macrophage recruitment wounds Drosophila. We find actin-regulatory protein Ena a master regulator lamellipodial dynamics migrating macrophages where it remodels form linear filaments can then be bundled together by cross-linker Fascin. In contrast, formin Dia...

In Drosophila blood, plasmatocytes of the haemocyte lineage represent functional equivalent vertebrate macrophages and have become an established in vivo model with which to study macrophage function behaviour. However, use as a has been limited by historical perspective that homogenous population cells, contrast high levels heterogeneity macrophages. Recently, number groups reported transcriptomic approaches suggest existence plasmatocyte heterogeneity, while we identified enhancer elements...

Ena/VASP proteins negatively regulate cell motility and contribute to repulsion from several guidance cues; however, there is currently no evidence for a role downstream of Eph receptors. receptors mediate ephrins at sites intercellular contact during developmental migrations. For example, the expression ephrin-Bs in posterior halves somites restricts neural crest migration anterior halves. Here we show that ephrin-B2 destabilises lamellipodia when presented substrate-bound or soluble form....