Abstract
Neutrophil extracellular traps (NETs) are released as neutrophils die in vitro in a process requiring hours, leaving a temporal gap that invasive microbes may exploit. Neutrophils capable of migration and phagocytosis while undergoing NETosis have not been documented. During Gram-positive skin infections, we directly visualized live polymorphonuclear cells (PMNs) in vivo rapidly releasing NETs, which prevented systemic bacterial dissemination. NETosis occurred during crawling, thereby casting large areas of NETs. NET-releasing PMNs developed diffuse decondensed nuclei, ultimately becoming devoid of DNA. Cells with abnormal nuclei showed unusual crawling behavior highlighted by erratic pseudopods and hyperpolarization consistent with the nucleus being a fulcrum for crawling. A requirement for both Toll-like receptor 2 and complement-mediated opsonization tightly regulated NET release. Additionally, live human PMNs injected into mouse skin developed decondensed nuclei and formed NETS in vivo, and intact anuclear neutrophils were abundant in Gram-positive human abscesses. Therefore early in infection NETosis involves neutrophils that do not undergo lysis and retain the ability to multitask.
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References
Kollef, M.H. & Micek, S.T. Methicillin-resistant Staphylococcus aureus: a new community-acquired pathogen? Curr. Opin. Infect. Dis. 19, 161–168 (2006).
Skrupky, L.P., Micek, S.T. & Kollef, M.H. Bench-to-bedside review: Understanding the impact of resistance and virulence factors on methicillin-resistant Staphylococcus aureus infections in the intensive care unit. Crit. Care 13, 222 (2009).
Angus, D.C. et al. Epidemiology of severe sepsis in the United States: analysis of incidence, outcome and associated costs of care. Crit. Care Med. 29, 1303–1310 (2001).
Martin, G.S., Mannino, D.M., Eaton, S. & Moss, M. The epidemiology of sepsis in the United States from 1979 through 2000. N. Engl. J. Med. 348, 1546–1554 (2003).
Cole, J.N., Barnett, T.C., Nizet, V. & Walker, M.J. Molecular insight into invasive group A streptococcal disease. Nat. Rev. Microbiol. 9, 724–736 (2011).
Li, P. et al. PAD4 is essential for antibacterial innate immunity mediated by neutrophil extracellular traps. J. Exp. Med. 207, 1853–1862 (2010).
Nauseef, W.M. How human neutrophils kill and degrade microbes: an integrated view. Immunol. Rev. 219, 88–102 (2007).
Segal, A.W. How neutrophils kill microbes. Annu. Rev. Immunol. 23, 197–223 (2005).
Brinkmann, V. et al. Neutrophil extracellular traps kill bacteria. Science 303, 1532–1535 (2004).
Brinkmann, V. & Zychlinsky, A. Beneficial suicide: why neutrophils die to make NETs. Nat. Rev. Microbiol. 5, 577–582 (2007).
Fuchs, T.A. et al. Novel cell death program leads to neutrophil extracellular traps. J. Cell Biol. 176, 231–241 (2007).
Lee, W.L., Harrison, R.E. & Grinstein, S. Phagocytosis by neutrophils. Microbes Infect. 5, 1299–1306 (2003).
Flannagan, R.S., Cosio, G. & Grinstein, S. Antimicrobial mechanisms of phagocytes and bacterial evasion strategies. Nat. Rev. Microbiol. 7, 355–366 (2009).
Pilsczek, F.H. et al. A novel mechanism of rapid nuclear neutrophil extracellular trap formation in response to Staphylococcus aureus. J. Immunol. 185, 7413–7425 (2010).
Clark, S.R. et al. Platelet TLR4 activates neutrophil extracellular traps to ensnare bacteria in septic blood. Nat. Med. 13, 463–469 (2007).
Ji, P., Jayapal, S.R. & Lodish, H.F. Enucleation of cultured mouse fetal erythroblasts requires Rac GTPases and mDia2. Nat. Cell Biol. 10, 314–321 (2008).
Wang, Y. et al. Histone hypercitrullination mediates chromatin decondensation and neutrophil extracellular trap formation. J. Cell Biol. 184, 205–213 (2009).
Papayannopoulos, V., Metzler, K.D., Hakkim, A. & Zychlinsky, A. Neutrophil elastase and myeloperoxidase regulate the formation of neutrophil extracellular traps. J. Cell Biol. 191, 677–691 (2010).
Yousefi, S., Mihalache, C., Kozlowski, E., Schmid, I. & Simon, H.U. Viable neutrophils release mitochondrial DNA to form neutrophil extracellular traps. Cell Death Differ. 16, 1438–1444 (2009).
Yousefi, S. et al. Catapult-like release of mitochondrial DNA by eosinophils contributes to antibacterial defense. Nat. Med. 14, 949–953 (2008).
Hajishengallis, G. & Lambris, J.D. Crosstalk pathways between Toll-like receptors and the complement system. Trends Immunol. 31, 154–163 (2010).
Hakkim, A. et al. Activation of the Raf-MEK-ERK pathway is required for neutrophil extracellular trap formation. Nat. Chem. Biol. 7, 75–77 (2011).
Yan, J. et al. Glutathione Reductase facilitates host defense by sustaining phagocytic oxidative burst and promoting the development of neutrophil extracellular traps. J. Immunol. 188, 2316–2327 (2012).
Malawista, S.E. & Van Blaricom, G. Phagocytic capacity of cytokineplasts from human blood polymorphonuclear leukocytes. Blood Cells 12, 167–177 (1986).
Malawista, S.E. & Van Blaricom, G. Cytoplasts made from human blood polymorphonuclear leukocytes with or without heat: preservation of both motile function and respiratory burst oxidase activity. Proc. Natl. Acad. Sci. USA 84, 454–458 (1987).
Malawista, S.E., Van Blaricom, G. & Breitenstein, M.G. Cryopreservable neutrophil surrogates. Stored cytoplasts from human polymorphonuclear leukocytes retain chemotactic, phagocytic, and microbicidal function. J. Clin. Invest. 83, 728–732 (1989).
Malawista, S.E., Montgomery, R.R. & van Blaricom, G. Evidence for reactive nitrogen intermediates in killing of staphylococci by human neutrophil cytoplasts. A new microbicidal pathway for polymorphonuclear leukocytes. J. Clin. Invest. 90, 631–636 (1992).
Friedl, P., Wolf, K. & Lammerding, J. Nuclear mechanics during cell migration. Curr. Opin. Cell Biol. 23, 55–64 (2011).
Dahl, K.N., Booth-Gauthier, E.A. & Ladoux, B. In the middle of it all: mutual mechanical regulation between the nucleus and the cytoskeleton. J. Biomech. 43, 2–8 (2010).
Remijsen, Q. et al. Dying for a cause: NETosis, mechanisms behind an antimicrobial cell death modality. Cell Death Differ. 18, 581–588 (2011).
Amulic, B. & Hayes, G. Neutrophil extracellular traps. Curr. Biol. 21, R297–R298 (2011).
Berends, E.T. et al. Nuclease expression by Staphylococcus aureus facilitates escape from neutrophil extracellular traps. J. Innate Immun. 2, 576–586 (2010).
Sumby, P. et al. Extracellular deoxyribonuclease made by group A Streptococcus assists pathogenesis by enhancing evasion of the innate immune response. Proc. Natl. Acad. Sci. USA 102, 1679–1684 (2005).
Buchanan, J.T. et al. DNase expression allows the pathogen group A Streptococcus to escape killing in neutrophil extracellular traps. Curr. Biol. 16, 396–400 (2006).
Walker, M.J. et al. DNase Sda1 provides selection pressure for a switch to invasive group A streptococcal infection. Nat. Med. 13, 981–985 (2007).
Ji, P., Murata-Hori, M. & Lodish, H.F. Formation of mammalian erythrocytes: chromatin condensation and enucleation. Trends Cell Biol. 21, 409–415 (2011).
Malawista, S.E. & De Boisfleury Chevance, A. The cytokineplast: purified, stable, and functional motile machinery from human blood polymorphonuclear leukocytes. J. Cell Biol. 95, 960–973 (1982).
Kessenbrock, K. et al. Netting neutrophils in autoimmune small-vessel vasculitis. Nat. Med. 15, 623–625 (2009).
Fuchs, T.A. et al. Extracellular DNA traps promote thrombosis. Proc. Natl. Acad. Sci. USA 107, 15880–15885 (2010).
Hakkim, A. et al. Impairment of neutrophil extracellular trap degradation is associated with lupus nephritis. Proc. Natl. Acad. Sci. USA 107, 9813–9818 (2010).
Manzenreiter, R. et al. Ultrastructural characterization of cystic fibrosis sputum using atomic force and scanning electron microscopy. J. Cyst. Fibros. 11, 84–92 (2012).
Young, R.L. et al. Neutrophil extracellular trap (NET)-mediated killing of Pseudomonas aeruginosa: evidence of acquired resistance within the CF airway, independent of CFTR. PLoS ONE 6, e23637 (2011).
Kaltwasser, M., Wiegert, T. & Schumann, W. Construction and application of epitope- and green fluorescent protein-tagging integration vectors for Bacillus subtilis. Appl. Environ. Microbiol. 68, 2624–2628 (2002).
Brückner, R. Gene replacement in Staphylococcus carnosus and Staphylococcus xylosus. FEMS Microbiol. Lett. 151, 1–8 (1997).
Diep, B.A. et al. Complete genome sequence of USA300, an epidemic clone of community-acquired meticillin-resistant Staphylococcus aureus. Lancet 367, 731–739 (2006).
Wu, K. et al. Caenorhabditis elegans as a host model for community-associated methicillin-resistant Staphylococcus aureus. Clin. Microbiol. Infect. 16, 245–254 (2010).
Ho, M., Hickey, M.J., Murray, A.G., Andonegui, G. & Kubes, P. Visualization of Plasmodium falciparum–endothelium interactions in human microvasculature: mimicry of leukocyte recruitment. J. Exp. Med. 192, 1205–1211 (2000).
Carvalho-Tavares, J. et al. A role for platelets and endothelial selectins in tumor necrosis factor-α–induced leukocyte recruitment in the brain microvasculature. Circ. Res. 87, 1141–1148 (2000).
Acknowledgements
The pBT2 was a gift from R. Brückner (University of Kaiserslautern). Myd88−/− and Tlr2−/− mice were provided by S. Akira (Osaka University). T. Graf (Barcelona, Spain) provided the Tg(LysMeGFP). We thank D. Knight and C. Baddick for technical assistance and ongoing support. We acknowledge P. Colarusso and the support staff of the Snyder Institute Live Cell Imaging Facility for assisting in the image capturing and analysis (Canada Foundation for Innovation funded). We also thank the University of Calgary Flow Cytometry Facility and L. Kennedy for their assistance. We are grateful to P. Forsyth for use of the IVIS 200. We thank the physicians, nurses and support staff in the Division of Infectious Diseases in the Department of Medicine, Alberta Health Services–Calgary and Area for assistance in obtaining clinical samples. We thank E. Yung, C. Horn, K. Nelson and K. Headley from Calgary Lab Services for assistance with the electron microscopy experiments. The Canadian Institute of Health Research (CIHR) provided the operating grants to support this work. P.K. is an Alberta Innovates–Health Solutions (AIHS) Scientist, Canada Research Chair and the Snyder Chair in Critical Care Medicine. B. Petri received an AIHS postdoctoral fellowship. B. Yipp is a Clinical Scholar (Department of Critical Care Medicine, Calgary), an AIHS clinical fellow and a CIHR fellow. During a portion of this study he received salary support from the Rockefeller University by Grant Award Number UL1RR024143 from the National Center for Research Resources (NCRR), a component of the US National Institutes of Health (NIH) and NIH Roadmap for Medical Research. The contents are solely the responsibility of the authors and do not necessarily represent the official views of the NCRR or the NIH.
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B.G.Y. and B.P. designed the overall study, performed experiments, analyzed the data and wrote the manuscript, D.S. designed, performed and analyzed the transmission electron microscopy experiments, C.N.J. designed, performed and analyzed the immunofluorescence microscopy experiments, B.N.V.S. performed intravital imaging, L.D.Z. performed intravital imaging, Xenogen and dissemination experiments and analyzed the data, K.P. performed human neutrophil experiments, M.A. performed in vitro NET assays, K.W. developed the transgenic bacteria, H.C.M. helped develop the imaging analysis protocols, S.E.M. and A.d.B.C. designed and performed the human cytoplast experiments, K.Z. designed and supervised the development of the transgenic bacteria and provided expert advice on microbiology, J.C. designed the clinical experiments, supervised the acquisition of patient samples and clinical histories and provided expert advice on infectious diseases and microbiology, and P.K. provided overall supervision, analyzed the data and wrote the manuscript.
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Supplementary Text and Figures
Supplementary Figures 1–8 and Supplementary Table 1 (PDF 2439 kb)
Supplementary Video 1
Live emigrated neutrophils rapidly form NETs in vivo within Gram-positive infected skin. Spinning-disk confocal intravital microscopy was performed using SYTOX Orange to visualize extracellular DNA. Neutrophils (green) chemotax through tissue NETs (red) in response to S. aureus (Xen29). PMNs do not take up the vital dye SYTOX. Neutrophils are hyperpolarized and form multiple pseudopods. White arrows demonstrate aberrant PMN crawling throughout NETs with hyperpolarization and multiple pseudopods. (MOV 1570 kb)
Supplementary Video 2
Live emigrated neutrophils rapidly release extracellular histones as a component of NETs during a Gram-positive infection. PE-conjugated histone specific antibody demonstrates extracellular histone proteins (red) as a major component of NET structure. Live PMN chemotax throughout the tissue in response to S. aureus (Xen8.1). (MOV 2306 kb)
Supplementary Video 3
Live emigrated PMN undergo NETosis while crawling during a Gram-positive infection. In vivo PMN nuclei were prelabeled with the cell-permeable dye SYTO 60. The NETosing PMN continues to crawl toward the live GFP-staphylococcus. Released NETs surround the PMN. At the conclusion of the video, we changed to Z-stack imaging, and this PMN is highlighted in Figure 2a. During the 3D imaging this PMN eventually engulfs the GFP-bacteria seen in the video. (MOV 784 kb)
Supplementary Video 4
Live PMNs form NETs while crawling in vivo. Four-color spinning-disk confocal intravital microscopy was used to visualize NET release from live PMNs in response to Gram-positive skin infection. A PMN (yellow) that is crawling while releasing NETs is circled. Extracellular DNA NETs are visualized using the cell-impermeable DNA dye SYTOX Orange. GFP-staphylococcus can be seen within this crawling PMN. A PMN with retained intracellular nuclear dye (SYTO 60, blue) can be seen crawling to the right of the highlighted NETTing PMN. This cell is not releasing NETs. (MOV 4726 kb)
Supplementary Video 5
In vivo intracellular imaging demonstrates PMNs with normal, diffuse and absent nuclei during a Gram-positive skin infection. Normal nuclei are easily distinguished by their distinct multilobar morphology. Anuclear PMNs are alive and continue to migrate. Examples are demonstrated of anuclear PMNs engorged with GFP-staphylococcus as well as anuclear PMNs devoid of bacteria. A PMN with an abnormal diffuse nucleus is highlighted for its multiple and erratic pseudopod formation and hyperpolarization. NETs are visualized within the area of anuclear PMNs. (MOV 8034 kb)
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Yipp, B., Petri, B., Salina, D. et al. Infection-induced NETosis is a dynamic process involving neutrophil multitasking in vivo. Nat Med 18, 1386–1393 (2012). https://doi.org/10.1038/nm.2847
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DOI: https://doi.org/10.1038/nm.2847
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