Publications by category
Journal articles
Campbell JS, Davidson AJ, Todd H, Rodrigues FSLM, Elliot AM, Early JJ, Lyons DA, Feng Y, Wood W (2021). PTPN21/Pez is a Novel and Evolutionarily Conserved Key Regulator of Inflammation In Vivo.
Curr Biol,
31(4), 875-883.e5.
Abstract:
PTPN21/Pez is a Novel and Evolutionarily Conserved Key Regulator of Inflammation In Vivo.
Drosophila provides a powerful model in which to study inflammation in vivo, and previous studies have revealed many of the key signaling events critical for recruitment of immune cells to tissue damage. In the fly, wounding stimulates the rapid production of hydrogen peroxide (H2O2).1,2 This then acts as an activation signal by triggering a signaling pathway within responding macrophages by directly activating the Src family kinase (SFK) Src42A,3 which in turn phosphorylates the damage receptor Draper. Activated Draper then guides macrophages to the wound through the detection of an as-yet unidentified chemoattractant.3-5 Similar H2O2-activated signaling pathways are also critical for leukocyte recruitment following wounding in larval zebrafish,6-9 where H2O2 activates the SFK Lyn to drive neutrophil chemotaxis. In this study, we combine proteomics, live imaging, and genetics in the fly to identify a novel regulator of inflammation in vivo; the PTP-type phosphatase Pez. Pez is expressed in macrophages and is critical for their efficient migration to wounds. Pez functions within activated macrophages downstream of damage-induced H2O2 and operates, via its band 4.1 ezrin, radixin, and moesin (FERM) domain, together with Src42A and Draper to ensure effective inflammatory cell recruitment to wounds. We show that this key role is conserved in vertebrates, because "crispant" zebrafish larvae of the Draper ortholog (MEGF10) or the Pez ortholog (PTPN21) exhibit a failure in leukocyte recruitment to wounds. This study demonstrates evolutionary conservation of inflammatory signaling and identifies MEGF10 and PTPN21 as potential therapeutic targets for the treatment of inflammatory disorders.
Abstract.
Author URL.
Campbell JS, Hallett MB (2015). Active calpain in phagocytically competent human neutrophils: Electroinjection of fluorogenic calpain substrate. Biochemical and Biophysical Research Communications, 457(3), 341-346.
Lewis KJ, Masterman B, Laffafian I, Dewitt S, Campbell JS, Hallett MB (2014). Minimal impact electro-injection of cells undergoing dynamic shape change reveals calpain activation. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, 1843(6), 1182-1187.
Chapters
Hallett MB, Campbell JS, Laffafian I, Dewitt S (2020). Microinjection and Micropipette-Controlled Phagocytosis Methods for Neutrophils. In (Ed)
Methods in Molecular Biology, 117-125.
Abstract:
Microinjection and Micropipette-Controlled Phagocytosis Methods for Neutrophils
Abstract.
Publications by year
2023
Campbell JS, Bebes A, Pradhan A, Yuecel R, Brown A, Wakefield JG (2023). Characterising phagocytes and measuring phagocytosis from live<i>Galleria mellonella</i>larvae.
Abstract:
Characterising phagocytes and measuring phagocytosis from liveGalleria mellonellalarvae
AbstractOver the last 20 years, the larva of the greater waxmoth,Galleria mellonella, has rapidly increased in popularity as anin vivomammalian replacement model organism for the study of human pathogens. Despite this, experimental readouts of response to infection are generally limited to observing the melanisation cascade – where the organism turns black as part of the systemic immune response – and quantifying larval death over time. As an invertebrate,Galleriaharbour an innate immune system comprised of both humoral components and a repertoire of innate immune cells – termed hemocytes. Though information on subtypes of hemocytes exist, there are conflicting reports on their exact number and function. Flow cytometry has previously been used to assayGalleriahemocytes, but protocols include both centrifugation and fixation - physical methods which have the potential to affect hemocyte morphology prior to analysis. Here, we present a method for live hemocyte analysis by flow cytometry, revealing thatGalleriahemocytes constitute only a single resolvable population, based on relative size or internal complexity. Using fluorescent zymosan particles, we extend our method to show that up to 80% of theGalleriahemocyte population display phagocytic capability. Finally, we demonstrate that the developed assay reliably replicatesin vitrodata, showing that cell wall β-1,3-glucan masking byCandida albicanssubverts phagocytic responses. As such, our method provides a new tool with which to rapidly assess phagocytosis and understand live infection dynamics inGalleria.
Abstract.
2021
Campbell JS, Davidson AJ, Todd H, Rodrigues FSLM, Elliot AM, Early JJ, Lyons DA, Feng Y, Wood W (2021). PTPN21/Pez is a Novel and Evolutionarily Conserved Key Regulator of Inflammation In Vivo.
Curr Biol,
31(4), 875-883.e5.
Abstract:
PTPN21/Pez is a Novel and Evolutionarily Conserved Key Regulator of Inflammation In Vivo.
Drosophila provides a powerful model in which to study inflammation in vivo, and previous studies have revealed many of the key signaling events critical for recruitment of immune cells to tissue damage. In the fly, wounding stimulates the rapid production of hydrogen peroxide (H2O2).1,2 This then acts as an activation signal by triggering a signaling pathway within responding macrophages by directly activating the Src family kinase (SFK) Src42A,3 which in turn phosphorylates the damage receptor Draper. Activated Draper then guides macrophages to the wound through the detection of an as-yet unidentified chemoattractant.3-5 Similar H2O2-activated signaling pathways are also critical for leukocyte recruitment following wounding in larval zebrafish,6-9 where H2O2 activates the SFK Lyn to drive neutrophil chemotaxis. In this study, we combine proteomics, live imaging, and genetics in the fly to identify a novel regulator of inflammation in vivo; the PTP-type phosphatase Pez. Pez is expressed in macrophages and is critical for their efficient migration to wounds. Pez functions within activated macrophages downstream of damage-induced H2O2 and operates, via its band 4.1 ezrin, radixin, and moesin (FERM) domain, together with Src42A and Draper to ensure effective inflammatory cell recruitment to wounds. We show that this key role is conserved in vertebrates, because "crispant" zebrafish larvae of the Draper ortholog (MEGF10) or the Pez ortholog (PTPN21) exhibit a failure in leukocyte recruitment to wounds. This study demonstrates evolutionary conservation of inflammatory signaling and identifies MEGF10 and PTPN21 as potential therapeutic targets for the treatment of inflammatory disorders.
Abstract.
Author URL.
2020
Hallett MB, Campbell JS, Laffafian I, Dewitt S (2020). Microinjection and Micropipette-Controlled Phagocytosis Methods for Neutrophils. In (Ed)
Methods in Molecular Biology, 117-125.
Abstract:
Microinjection and Micropipette-Controlled Phagocytosis Methods for Neutrophils
Abstract.
2015
Campbell JS, Hallett MB (2015). Active calpain in phagocytically competent human neutrophils: Electroinjection of fluorogenic calpain substrate. Biochemical and Biophysical Research Communications, 457(3), 341-346.
2014
Lewis KJ, Masterman B, Laffafian I, Dewitt S, Campbell JS, Hallett MB (2014). Minimal impact electro-injection of cells undergoing dynamic shape change reveals calpain activation. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, 1843(6), 1182-1187.
