601
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Karaji N, Sattentau QJ. Efferocytosis of Pathogen-Infected Cells. Front Immunol 2017; 8:1863. [PMID: 29312342 PMCID: PMC5743670 DOI: 10.3389/fimmu.2017.01863] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/07/2017] [Indexed: 12/20/2022] Open
Abstract
The prompt and efficient clearance of unwanted and abnormal cells by phagocytes is termed efferocytosis and is crucial for organism development, maintenance of tissue homeostasis, and regulation of the immune system. Dying cells are recognized by phagocytes through pathways initiated via "find me" signals, recognition via "eat me" signals and down-modulation of regulatory "don't eat me" signals. Pathogen infection may trigger cell death that drives phagocytic clearance in an immunologically silent, or pro-inflammatory manner, depending on the mode of cell death. In many cases, efferocytosis is a mechanism for eliminating pathogens and pathogen-infected cells; however, some pathogens have subverted this process and use efferocytic mechanisms to avoid innate immune detection and assist phagocyte infection. In parallel, phagocytes can integrate signals received from infected dying cells to elicit the most appropriate effector response against the infecting pathogen. This review focuses on pathogen-induced cell death signals that drive infected cell recognition and uptake by phagocytes, and the outcomes for the infected target cell, the phagocyte, the pathogen and the host.
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Affiliation(s)
- Niloofar Karaji
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
| | - Quentin J Sattentau
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
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602
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Hopke A, Wheeler RT. In vitro Detection of Neutrophil Traps and Post-attack Cell Wall Changes in Candida Hyphae. Bio Protoc 2017; 7:e2213. [PMID: 28670603 DOI: 10.21769/bioprotoc.2213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In this protocol we describe how to visualize neutrophil extracellular traps (NETs) and fungal cell wall changes in the context of the coculture of mouse neutrophils with fungal hyphae of Candida albicans. These protocols are easily adjusted to test a wide array of hypotheses related to the impact of immune cells on fungi and the cell wall, making them promising tools for exploring host-pathogen interactions during fungal infection.
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Affiliation(s)
- Alex Hopke
- Molecular and Biomedical Sciences, University of Maine, Orono, Maine, USA
| | - Robert T Wheeler
- Molecular and Biomedical Sciences, University of Maine, Orono, Maine, USA.,Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine, USA
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603
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Gasteiger G, D'Osualdo A, Schubert DA, Weber A, Bruscia EM, Hartl D. Cellular Innate Immunity: An Old Game with New Players. J Innate Immun 2016; 9:111-125. [PMID: 28006777 DOI: 10.1159/000453397] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 12/29/2022] Open
Abstract
Innate immunity is a rapidly evolving field with novel cell types and molecular pathways being discovered and paradigms changing continuously. Innate and adaptive immune responses are traditionally viewed as separate from each other, but emerging evidence suggests that they overlap and mutually interact. Recently discovered cell types, particularly innate lymphoid cells and myeloid-derived suppressor cells, are gaining increasing attention. Here, we summarize and highlight current concepts in the field, focusing on innate immune cells as well as the inflammasome and DNA sensing which appear to be critical for the activation and orchestration of innate immunity, and may provide novel therapeutic opportunities for treating autoimmune, autoinflammatory, and infectious diseases.
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Affiliation(s)
- Georg Gasteiger
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg Medical Center, Freiburg, Germany
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604
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Ajendra J, Specht S, Ziewer S, Schiefer A, Pfarr K, Parčina M, Kufer TA, Hoerauf A, Hübner MP. NOD2 dependent neutrophil recruitment is required for early protective immune responses against infectious Litomosoides sigmodontis L3 larvae. Sci Rep 2016; 6:39648. [PMID: 28004792 PMCID: PMC5177913 DOI: 10.1038/srep39648] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/15/2016] [Indexed: 12/22/2022] Open
Abstract
Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) recognizes muramyl dipeptide (MDP) of bacterial cell walls, triggering NFκB-induced pro-inflammation. As most human pathogenic filariae contain Wolbachia endobacteria that synthesize the MDP-containing cell wall precursor lipid II, NOD2’s role during infection with the rodent filaria Litomosoides sigmodontis was investigated. In NFκB reporter-cells, worm-extract containing Wolbachia induced NOD2 and NOD1. NOD2-deficient mice infected with L. sigmodontis had significantly more worms than wildtype controls early in infection. Increased worm burden was not observed after subcutaneous infection, suggesting that protective NOD2-dependent immune responses occur within the skin. Flow cytometry demonstrated that neutrophil recruitment to the skin was impaired in NOD2−/− mice after intradermal injection of third stage larvae (L3), and blood neutrophil numbers were reduced after L. sigmodontis infection. PCR array supported the requirement of NOD2 for recruitment of neutrophils to the skin, as genes associated with neutrophil recruitment and activation were downregulated in NOD2−/− mice after intradermal L3 injection. Neutrophil depletion before L. sigmodontis infection increased worm recovery in wildtype mice, confirming that neutrophils are essential against invading L3 larvae. This study indicates that NOD-like receptors are implemented in first-line protective immune responses against filarial nematodes.
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Affiliation(s)
- Jesuthas Ajendra
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Sebastian Ziewer
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Andrea Schiefer
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Marijo Parčina
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Thomas A Kufer
- Institute of Nutritional Medicine, University Hohenheim, Stuttgart, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Marc P Hübner
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
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605
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Maueröder C, Mahajan A, Paulus S, Gößwein S, Hahn J, Kienhöfer D, Biermann MH, Tripal P, Friedrich RP, Munoz LE, Neurath MF, Becker C, Schett GA, Herrmann M, Leppkes M. Ménage-à-Trois: The Ratio of Bicarbonate to CO 2 and the pH Regulate the Capacity of Neutrophils to Form NETs. Front Immunol 2016; 7:583. [PMID: 28018350 PMCID: PMC5145884 DOI: 10.3389/fimmu.2016.00583] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/25/2016] [Indexed: 12/23/2022] Open
Abstract
In this study, we identified and characterized the potential of a high ratio of bicarbonate to CO2 and a moderately alkaline pH to render neutrophils prone to undergo neutrophil extracellular trap (NET) formation. Both experimental settings increased the rate of spontaneous NET release and potentiated the NET-inducing capacity of phorbol esters (phorbol-2-myristate-13-acetate), ionomycin, monosodium urate, and LPS. In contrast, an acidic environment impaired NET formation both spontaneous and induced. Our findings indicate that intracellular alkalinization of neutrophils in response to an alkaline environment leads to an increase of intracellular calcium and neutrophil activation. We further found that the anion channel blocker DIDS strongly reduced NET formation induced by bicarbonate. This finding suggests that the effects observed are due to a molecular program that renders neutrophils susceptible to NET formation. Inflammatory foci may be characterized by an acidic environment. Our data indicate that NET formation is favored by the higher pH at the border regions of inflamed areas. Moreover, our findings highlight the necessity for strict pH control during assays of NET formation.
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Affiliation(s)
- Christian Maueröder
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Aparna Mahajan
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Susanne Paulus
- Department of Medicine 1 - Gastroenterology, Pulmonology and Endocrinology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Stefanie Gößwein
- Department of Medicine 1 - Gastroenterology, Pulmonology and Endocrinology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Jonas Hahn
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Deborah Kienhöfer
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Mona H Biermann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Philipp Tripal
- Optical Imaging Center Erlangen (OICE), Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Ralf P Friedrich
- ENT Clinic, Section of Experimental Oncology and Nanomedicine (SEON), University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Luis E Munoz
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Markus F Neurath
- Department of Medicine 1 - Gastroenterology, Pulmonology and Endocrinology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Christoph Becker
- Department of Medicine 1 - Gastroenterology, Pulmonology and Endocrinology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Georg Andreas Schett
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Martin Herrmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Moritz Leppkes
- Department of Medicine 1 - Gastroenterology, Pulmonology and Endocrinology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
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606
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Pfeiler S, Stark K, Massberg S, Engelmann B. Propagation of thrombosis by neutrophils and extracellular nucleosome networks. Haematologica 2016; 102:206-213. [PMID: 27927771 DOI: 10.3324/haematol.2016.142471] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/17/2016] [Indexed: 12/23/2022] Open
Abstract
Neutrophils, early mediators of the innate immune defense, are recruited to developing thrombi in different types of thrombosis. They amplify intravascular coagulation by stimulating the tissue factor-dependent extrinsic pathway via inactivation of endogenous anticoagulants, enhancing factor XII activation or decreasing plasmin generation. Neutrophil-dependent prothrombotic mechanisms are supported by the externalization of decondensed nucleosomes and granule proteins that together form neutrophil extracellular traps. These traps, either in intact or fragmented form, are causally involved in various forms of experimental thrombosis as first indicated by their role in the enhancement of both microvascular thrombosis during bacterial infection and carotid artery thrombosis. Neutrophil extracellular traps can be induced by interactions of neutrophils with activated platelets; vice versa, these traps enhance adhesion of platelets via von Willebrand factor. Neutrophil-induced microvascular thrombus formation can restrict the dissemination and survival of blood-borne bacteria and thereby sustain intravascular immunity. Dysregulation of this innate immune pathway may support sepsis-associated coagulopathies. Notably, neutrophils and extracellular nucleosomes, together with platelets, critically promote fibrin formation during flow restriction-induced deep vein thrombosis. Neutrophil extracellular traps/extracellular nucleosomes are increased in thrombi and in the blood of patients with different vaso-occlusive pathologies and could be therapeutically targeted for the prevention of thrombosis. Thus, during infections and in response to blood vessel damage, neutrophils and externalized nucleosomes are major promoters of intravascular blood coagulation and thrombosis.
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Affiliation(s)
- Susanne Pfeiler
- Institut für Laboratoriumsmedizin, Ludwig-Maximilians-Universität, Munich, Germany
| | - Konstantin Stark
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-Universität, Munich, Germany
| | - Steffen Massberg
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-Universität, Munich, Germany
| | - Bernd Engelmann
- Institut für Laboratoriumsmedizin, Ludwig-Maximilians-Universität, Munich, Germany
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607
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Sercundes MK, Ortolan LS, Debone D, Soeiro-Pereira PV, Gomes E, Aitken EH, Neto AC, Russo M, D' Império Lima MR, Alvarez JM, Portugal S, Marinho CRF, Epiphanio S. Targeting Neutrophils to Prevent Malaria-Associated Acute Lung Injury/Acute Respiratory Distress Syndrome in Mice. PLoS Pathog 2016; 12:e1006054. [PMID: 27926944 PMCID: PMC5142790 DOI: 10.1371/journal.ppat.1006054] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/10/2016] [Indexed: 12/28/2022] Open
Abstract
Malaria remains one of the greatest burdens to global health, causing nearly 500,000 deaths in 2014. When manifesting in the lungs, severe malaria causes acute lung injury/acute respiratory distress syndrome (ALI/ARDS). We have previously shown that a proportion of DBA/2 mice infected with Plasmodium berghei ANKA (PbA) develop ALI/ARDS and that these mice recapitulate various aspects of the human syndrome, such as pulmonary edema, hemorrhaging, pleural effusion and hypoxemia. Herein, we investigated the role of neutrophils in the pathogenesis of malaria-associated ALI/ARDS. Mice developing ALI/ARDS showed greater neutrophil accumulation in the lungs compared with mice that did not develop pulmonary complications. In addition, mice with ALI/ARDS produced more neutrophil-attracting chemokines, myeloperoxidase and reactive oxygen species. We also observed that the parasites Plasmodium falciparum and PbA induced the formation of neutrophil extracellular traps (NETs) ex vivo, which were associated with inflammation and tissue injury. The depletion of neutrophils, treatment with AMD3100 (a CXCR4 antagonist), Pulmozyme (human recombinant DNase) or Sivelestat (inhibitor of neutrophil elastase) decreased the development of malaria-associated ALI/ARDS and significantly increased mouse survival. This study implicates neutrophils and NETs in the genesis of experimentally induced malaria-associated ALI/ARDS and proposes a new therapeutic approach to improve the prognosis of severe malaria.
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Affiliation(s)
- Michelle K. Sercundes
- Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
| | - Luana S. Ortolan
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Daniela Debone
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
| | | | - Eliane Gomes
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Elizabeth H. Aitken
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Antonio Condino Neto
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Momtchilo Russo
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Maria R. D' Império Lima
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - José M. Alvarez
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Silvia Portugal
- Center of Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Claudio R. F. Marinho
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Sabrina Epiphanio
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
- * E-mail:
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608
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Pieterse E, Jeremic I, Czegley C, Weidner D, Biermann MHC, Veissi S, Maueröder C, Schauer C, Bilyy R, Dumych T, Hoffmann M, Munoz LE, Bengtsson AA, Schett G, van der Vlag J, Herrmann M. Blood-borne phagocytes internalize urate microaggregates and prevent intravascular NETosis by urate crystals. Sci Rep 2016; 6:38229. [PMID: 27917897 PMCID: PMC5137018 DOI: 10.1038/srep38229] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/07/2016] [Indexed: 12/31/2022] Open
Abstract
Hyperuricemia is strongly linked to cardiovascular complications including atherosclerosis and thrombosis. In individuals with hyperuricemia, needle-shaped monosodium urate crystals (nsMSU) frequently form within joints or urine, giving rise to gouty arthritis or renal calculi, respectively. These nsMSU are potent instigators of neutrophil extracellular trap (NET) formation. Little is known on the mechanism(s) that prevent nsMSU formation within hyperuricemic blood, which would potentially cause detrimental consequences for the host. Here, we report that complement proteins and fetuins facilitate the continuous clearance by blood-borne phagocytes and resident macrophages of small urate microaggregates (UMA; <1 μm in size) that initially form in hyperuricemic blood. If this clearance fails, UMA exhibit bipolar growth to form typical full-sized nsMSU with a size up to 100 μm. In contrast to UMA, nsMSU stimulated neutrophils to release NETs. Under conditions of flow, nsMSU and NETs formed densely packed DNase I-resistant tophus-like structures with a high obstructive potential, highlighting the importance of an adequate and rapid removal of UMA from the circulation. Under pathological conditions, intravascularly formed nsMSU may hold the key to the incompletely understood association between NET-driven cardiovascular disease and hyperuricemia.
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Affiliation(s)
- Elmar Pieterse
- Department of Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Ivica Jeremic
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.,Institute of Rheumatology, Resavska 69, Belgrade, Serbia
| | - Christine Czegley
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Daniela Weidner
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Mona H C Biermann
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Susan Veissi
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Christian Maueröder
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Christine Schauer
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Rostyslav Bilyy
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.,Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Tetiana Dumych
- Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Markus Hoffmann
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Luis E Munoz
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | | | - Georg Schett
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Johan van der Vlag
- Department of Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Martin Herrmann
- Department of Internal Medicine 3, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
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609
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Agraz-Cibrian JM, Giraldo DM, Mary FM, Urcuqui-Inchima S. Understanding the molecular mechanisms of NETs and their role in antiviral innate immunity. Virus Res 2016; 228:124-133. [PMID: 27923601 DOI: 10.1016/j.virusres.2016.11.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/30/2016] [Accepted: 11/30/2016] [Indexed: 01/09/2023]
Abstract
Polymorphonuclear neutrophils (PMNs) are the most abundant cells in the context of innate immunity; they are one of the first cells to arrive at the site of viral infection constituting the first line of defense in response to invading pathogens. Indeed, neutrophils are provided with several defense mechanisms including release of cytokines, cytotoxic granules and the last recently described neutrophil extracellular traps (NETs). The main components of NETs are DNA, granular antimicrobial peptides, and nuclear and cytoplasmic proteins, that together play an important role in the innate immune response. While NETs were first described as a mechanism against bacteria and fungi, recently, several studies are beginning to elucidate how NETs are involved in the host antiviral response and the prominent characteristics of this new mechanism are discussed in the present review.
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Affiliation(s)
- Juan Manuel Agraz-Cibrian
- Unidad Académica de Ciencias Químico Biológicas y Farmacéuticas, Universidad Autónoma de Nayarit, Tepic, Nayarit, Mexico.
| | - Diana M Giraldo
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
| | - Fafutis-Morris Mary
- Laboratorio de Inmunología, Departamento de Fisiología, CUCS, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
| | - Silvio Urcuqui-Inchima
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
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610
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Cystic fibrosis lung environment and Pseudomonas aeruginosa infection. BMC Pulm Med 2016; 16:174. [PMID: 27919253 PMCID: PMC5139081 DOI: 10.1186/s12890-016-0339-5] [Citation(s) in RCA: 229] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/24/2016] [Indexed: 12/20/2022] Open
Abstract
Background The airways of patients with cystic fibrosis (CF) are highly complex, subject to various environmental conditions as well as a distinct microbiota. Pseudomonas aeruginosa is recognized as one of the most important pulmonary pathogens and the predominant cause of morbidity and mortality in CF. A multifarious interplay between the host, pathogens, microbiota, and the environment shapes the course of the disease. There have been several excellent reviews detailing CF pathology, Pseudomonas and the role of environment in CF but only a few reviews connect these entities with regards to influence on the overall course of the disease. A holistic understanding of contributing factors is pertinent to inform new research and therapeutics. Discussion In this article, we discuss the deterministic alterations in lung physiology as a result of CF. We also revisit the impact of those changes on the microbiota, with special emphasis on P. aeruginosa and the influence of other non-genetic factors on CF. Substantial past and current research on various genetic and non-genetic aspects of cystic fibrosis has been reviewed to assess the effect of different factors on CF pulmonary infection. A thorough review of contributing factors in CF and the alterations in lung physiology indicate that CF lung infection is multi-factorial with no isolated cause that should be solely targeted to control disease progression. A combinatorial approach may be required to ensure better disease outcomes. Conclusion CF lung infection is a complex disease and requires a broad multidisciplinary approach to improve CF disease outcomes. A holistic understanding of the underlying mechanisms and non-genetic contributing factors in CF is central to development of new and targeted therapeutic strategies.
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611
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Biermann MHC, Podolska MJ, Knopf J, Reinwald C, Weidner D, Maueröder C, Hahn J, Kienhöfer D, Barras A, Boukherroub R, Szunerits S, Bilyy R, Hoffmann M, Zhao Y, Schett G, Herrmann M, Munoz LE. Oxidative Burst-Dependent NETosis Is Implicated in the Resolution of Necrosis-Associated Sterile Inflammation. Front Immunol 2016; 7:557. [PMID: 27990145 PMCID: PMC5131011 DOI: 10.3389/fimmu.2016.00557] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/18/2016] [Indexed: 02/05/2023] Open
Abstract
Necrosis is associated with a profound inflammatory response. The regulation of necrosis-associated inflammation, particularly the mechanisms responsible for resolution of inflammation is incompletely characterized. Nanoparticles are known to induce plasma membrane damage and necrosis followed by sterile inflammation. We observed that injection of metabolically inert nanodiamonds resulted in paw edema in WT and Ncf1** mice. However, while inflammation quickly resolved in WT mice, it persisted over several weeks in Ncf1** mice indicating failure of resolution of inflammation. Mechanistically, NOX2-dependent reactive oxygen species (ROS) production and formation of neutrophil extracellular traps were essential for the resolution of necrosis-induced inflammation: hence, by evaluating the fate of the particles at the site of inflammation, we observed that Ncf1** mice deficient in NADPH-dependent ROS failed to generate granulation tissue therefore being unable to trap the nanodiamonds. These data suggest that NOX2-dependent NETosis is crucial for preventing the chronification of the inflammatory response to tissue necrosis by forming NETosis-dependent barriers between the necrotic and healthy surrounding tissue.
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Affiliation(s)
- Mona H C Biermann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Malgorzata J Podolska
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Jasmin Knopf
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Christiane Reinwald
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Daniela Weidner
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Christian Maueröder
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Jonas Hahn
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Deborah Kienhöfer
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Alexandre Barras
- UMR CNRS 8520, Institut d'Electronique de Microélectronique et de Nanotechnologie (IEMN), Université Lille 1 , Villeneuve d'Ascq , France
| | - Rabah Boukherroub
- UMR CNRS 8520, Institut d'Electronique de Microélectronique et de Nanotechnologie (IEMN), Université Lille 1 , Villeneuve d'Ascq , France
| | - Sabine Szunerits
- UMR CNRS 8520, Institut d'Electronique de Microélectronique et de Nanotechnologie (IEMN), Université Lille 1 , Villeneuve d'Ascq , France
| | - Rostyslav Bilyy
- Danylo Halytsky Lviv National Medical University , Lviv , Ukraine
| | - Markus Hoffmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Yi Zhao
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University , Chengdu , China
| | - Georg Schett
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Martin Herrmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
| | - Luis E Munoz
- Department of Internal Medicine 3 - Rheumatology and Immunology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg , Erlangen , Germany
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612
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Hector A, Frey N, Hartl D. Update on host-pathogen interactions in cystic fibrosis lung disease. Mol Cell Pediatr 2016; 3:12. [PMID: 26905568 PMCID: PMC4764602 DOI: 10.1186/s40348-016-0039-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/16/2016] [Indexed: 12/05/2022] Open
Abstract
Bacterial and fungal infections are hallmarks of cystic fibrosis (CF) lung disease. In the era of long-term inhaled antibiotics and increasing CF patient survival, new "emerging" pathogens are detected in CF airways, yet their pathophysiological disease relevance remains largely controversial and incompletely defined. As a response to chronic microbial triggers, innate immune cells, particularly neutrophils, are continuously recruited into CF airways where they combat pathogens but also cause tissue injury through release of oxidants and proteases. The coordinated interplay between host immune cell activation and pathogens is essential for the outcome of CF lung disease. Here, we provide a concise overview and update on host-pathogen interactions in CF lung disease.
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Affiliation(s)
- Andreas Hector
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Nina Frey
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Dominik Hartl
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany.
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613
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Floyd M, Winn M, Cullen C, Sil P, Chassaing B, Yoo DG, Gewirtz AT, Goldberg JB, McCarter LL, Rada B. Swimming Motility Mediates the Formation of Neutrophil Extracellular Traps Induced by Flagellated Pseudomonas aeruginosa. PLoS Pathog 2016; 12:e1005987. [PMID: 27855208 PMCID: PMC5113990 DOI: 10.1371/journal.ppat.1005987] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 10/10/2016] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections often characterized by robust neutrophilic infiltration. Neutrophils provide the first line of defense against P. aeruginosa. Aside from their defense conferred by phagocytic activity, neutrophils also release neutrophil extracellular traps (NETs) to immobilize bacteria. Although NET formation is an important antimicrobial process, the details of its mechanism are largely unknown. The identity of the main components of P. aeruginosa responsible for triggering NET formation is unclear. In this study, our focus was to identify the main bacterial factors mediating NET formation and to gain insight into the underlying mechanism. We found that P. aeruginosa in its exponential growth phase promoted strong NET formation in human neutrophils while its NET-inducing ability dramatically decreased at later stages of bacterial growth. We identified the flagellum as the primary component of P. aeruginosa responsible for inducing NET extrusion as flagellum-deficient bacteria remained seriously impaired in triggering NET formation. Purified P. aeruginosa flagellin, the monomeric component of the flagellum, does not stimulate NET formation in human neutrophils. P. aeruginosa-induced NET formation is independent of the flagellum-sensing receptors TLR5 and NLRC4 in both human and mouse neutrophils. Interestingly, we found that flagellar motility, not flagellum binding to neutrophils per se, mediates NET release induced by flagellated bacteria. Immotile, flagellar motor-deficient bacterial strains producing paralyzed flagella did not induce NET formation. Forced contact between immotile P. aeruginosa and neutrophils restored their NET-inducing ability. Both the motAB and motCD genetic loci encoding flagellar motor genes contribute to maximal NET release; however the motCD genes play a more important role. Phagocytosis of P. aeruginosa and superoxide production by neutrophils were also largely dependent upon a functional flagellum. Taken together, the flagellum is herein presented for the first time as the main organelle of planktonic bacteria responsible for mediating NET release. Furthermore, flagellar motility, rather than binding of the flagellum to flagellum-sensing receptors on host cells, is required for P. aeruginosa to induce NET release.
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Affiliation(s)
- Madison Floyd
- College of Veterinary Medicine, Department of Infectious Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Matthew Winn
- College of Veterinary Medicine, Department of Infectious Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Christian Cullen
- College of Veterinary Medicine, Department of Infectious Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Payel Sil
- College of Veterinary Medicine, Department of Infectious Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Benoit Chassaing
- Center for Inflammation, Immunity, & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Dae-goon Yoo
- College of Veterinary Medicine, Department of Infectious Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Andrew T. Gewirtz
- Center for Inflammation, Immunity, & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Joanna B. Goldberg
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Linda L. McCarter
- Carver College of Medicine, Department of Microbiology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Balázs Rada
- College of Veterinary Medicine, Department of Infectious Diseases, The University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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614
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Johnson CM, O'Brien XM, Byrd AS, Parisi VE, Loosely AJ, Li W, Witt H, Faridi MH, LeFort CT, Gupta V, Kim M, Reichner JS. Integrin Cross-Talk Regulates the Human Neutrophil Response to Fungal β-Glucan in the Context of the Extracellular Matrix: A Prominent Role for VLA3 in the Antifungal Response. THE JOURNAL OF IMMUNOLOGY 2016; 198:318-334. [PMID: 27852744 DOI: 10.4049/jimmunol.1502381] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 10/20/2016] [Indexed: 11/19/2022]
Abstract
Candida albicans infection produces elongated hyphae resistant to phagocytic clearance compelling alternative neutrophil effector mechanisms to destroy these physically large microbial structures. Additionally, all tissue-based neutrophilic responses to fungal infections necessitate contact with the extracellular matrix (ECM). Neutrophils undergo a rapid, ECM-dependent mechanism of homotypic aggregation and NETosis in response to C. albicans mediated by the β2 integrin, complement receptor 3 (CR3, CD11b/CD18, αMβ2). Neither homotypic aggregation nor NETosis occurs when human neutrophils are exposed either to immobilized fungal β-glucan or to C. albicans hyphae without ECM. The current study provides a mechanistic basis to explain how matrix controls the antifungal effector functions of neutrophils under conditions that preclude phagocytosis. We show that CR3 ligation initiates a complex mechanism of integrin cross-talk resulting in differential regulation of the β1 integrins VLA3 (α3β1) and VLA5 (α5β1). These β1 integrins control distinct antifungal effector functions in response to either fungal β-glucan or C. albicans hyphae and fibronectin, with VLA3 inducing homotypic aggregation and VLA5 regulating NETosis. These integrin-dependent effector functions are controlled temporally whereby VLA5 and CR3 induce rapid, focal NETosis early after binding fibronectin and β-glucan. Within minutes, CR3 undergoes inside-out auto-activation that drives the downregulation of VLA5 and the upregulation of VLA3 to support neutrophil swarming and aggregation. Forcing VLA5 to remain in the activated state permits NETosis but prevents homotypic aggregation. Therefore, CR3 serves as a master regulator during the antifungal neutrophil response, controlling the affinity states of two different β1 integrins, which in turn elicit distinct effector functions.
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Affiliation(s)
- Courtney M Johnson
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Warren Alpert Medical School, Brown University, Providence, RI 02912.,Graduate Program in Pathobiology, Brown University, Providence, RI 02912
| | - Xian M O'Brien
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Warren Alpert Medical School, Brown University, Providence, RI 02912
| | - Angel S Byrd
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Warren Alpert Medical School, Brown University, Providence, RI 02912.,Graduate Program in Pathobiology, Brown University, Providence, RI 02912
| | - Valentina E Parisi
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Graduate Program in Pathobiology, Brown University, Providence, RI 02912
| | - Alex J Loosely
- Department of Physics, Brown University, Providence, RI 02912
| | - Wei Li
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903
| | - Hadley Witt
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Warren Alpert Medical School, Brown University, Providence, RI 02912.,Graduate Program in Pathobiology, Brown University, Providence, RI 02912
| | - Mohd H Faridi
- Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612
| | - Craig T LeFort
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Warren Alpert Medical School, Brown University, Providence, RI 02912
| | - Vineet Gupta
- Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612
| | - Minsoo Kim
- David H. Smith Center for Vaccine Biology and Immunology, Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642
| | - Jonathan S Reichner
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI 02903.,Warren Alpert Medical School, Brown University, Providence, RI 02912.,Graduate Program in Pathobiology, Brown University, Providence, RI 02912
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615
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Corsiero E, Pratesi F, Prediletto E, Bombardieri M, Migliorini P. NETosis as Source of Autoantigens in Rheumatoid Arthritis. Front Immunol 2016; 7:485. [PMID: 27895639 PMCID: PMC5108063 DOI: 10.3389/fimmu.2016.00485] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 10/21/2016] [Indexed: 12/29/2022] Open
Abstract
In neutrophils (but also in eosinophils and in mast cells), different inflammatory stimuli induce histone deimination, chromatin decondensation, and NET formation. These web-like structures that trap and kill microbes contain DNA, cationic granule proteins, and antimicrobial peptides, but the most abundant proteins are core histones. Histones contained in NETs have been deiminated, and arginines are converted in citrullines. While deimination is a physiological process amplified in inflammatory conditions, only individuals carrying genetic predisposition to develop rheumatoid arthritis (RA) make antibodies to deiminated proteins. These antibodies, collectively identified as anti-citrullinated proteins/peptides antibodies (ACPA), react with different deiminated proteins and display partially overlapping specificities. In this paper, we will summarize current evidence supporting the role of NETosis as critical mechanism in the breach of tolerance to self-antigens and in supporting expansion and differentiation of autoreactive cells. In fact, several lines of evidence connect NETosis with RA: RA unstimulated synovial fluid neutrophils display enhanced NETosis; sera from RA patients with Felty's syndrome bind deiminated H3 and NETs; a high number of RA sera bind deiminated H4 contained in NETs; human monoclonal antibodies generated from RA synovial B cells decorate NETs and bind deiminated histones. In RA, NETs represent on one side an important source of autoantigens bearing posttranslational modifications and fueling the production of ACPA. On the other side, NETs deliver signals that maintain an inflammatory milieu and contribute to the expansion and differentiation of ACPA-producing B cells.
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Affiliation(s)
- Elisa Corsiero
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | - Federico Pratesi
- Clinical Immunology and Allergy Unit, Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy
| | - Edoardo Prediletto
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | - Michele Bombardieri
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
| | - Paola Migliorini
- Clinical Immunology and Allergy Unit, Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy
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616
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Bliss-Moreau M, Chen AA, D'Cruz AA, Croker BA. A motive for killing: effector functions of regulated lytic cell death. Immunol Cell Biol 2016; 95:146-151. [PMID: 27826146 DOI: 10.1038/icb.2016.113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 11/03/2016] [Accepted: 11/04/2016] [Indexed: 12/23/2022]
Abstract
Immunological responses activated by pathogen recognition come in many guises. The proliferation, differentiation and recruitment of immune cells, and the production of inflammatory cytokines and chemokines are central to lifelong immunity. Cell death serves as a key function in the resolution of innate and adaptive immune responses. It also coordinates cell-intrinsic effector functions to restrict infection. Necrosis was formally considered a passive form of cell death or a consequence of pathogen virulence factor expression, and necrotic tissue is frequently associated with infection. However, there is now emerging evidence that points to a role for regulated forms of necrosis, such as pyroptosis and necroptosis, driving inflammation and shaping the immune response.
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Affiliation(s)
- Meghan Bliss-Moreau
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Alyce A Chen
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Akshay A D'Cruz
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Ben A Croker
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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617
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Pieterse E, Rother N, Yanginlar C, Hilbrands LB, van der Vlag J. Neutrophils Discriminate between Lipopolysaccharides of Different Bacterial Sources and Selectively Release Neutrophil Extracellular Traps. Front Immunol 2016; 7:484. [PMID: 27867387 PMCID: PMC5095130 DOI: 10.3389/fimmu.2016.00484] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 10/21/2016] [Indexed: 01/26/2023] Open
Abstract
The release of neutrophil extracellular traps (NETs), either during "suicidal" or "vital" NETosis, represents an important strategy of neutrophils to combat Gram-negative bacteria. Lipopolysaccharide (LPS), a major component of the outer membrane of Gram-negative bacteria, is a reported stimulus for NET formation. Although it is widely acknowledged that the structural diversity in LPS structures can elicit heterogeneous immune responses, species- and serotype-specific differences in the capacity of LPS to trigger NET formation have not yet been investigated. In the present study, we compared the NET-inducing potential of LPS derived from Escherichia coli (serotypes O55:B5, O127:B8, O128:B12, O111:B4, and O26:B6), Salmonella enterica (serotype enteritidis), and Pseudomonas aeruginosa (serotype 10), under platelet-free and platelet-rich conditions in vitro, and in whole blood ex vivo. Here, we demonstrate that under serum- and platelet-free conditions, mimicking tissue circumstances, neutrophils discriminate between LPS of different bacterial sources and selectively release NETs only in response to LPS derived from E. coli O128:B12 and P. aeruginosa 10, which both induced "suicidal" NETosis in an autophagy- and reactive oxygen species (ROS)-dependent, but TLR4-independent manner. Intriguingly, in whole blood cultures ex vivo, or in vitro in the presence of platelets, all LPS serotypes induced "vital" NET formation. This platelet-dependent release of NETs occurred rapidly without neutrophil cell death and was independent from ROS formation and autophagy but required platelet TLR4 and CD62P-dependent platelet-neutrophil interactions. Taken together, our data reveal a complex interplay between neutrophils and LPS, which can induce both "suicidal" and "vital" NETosis, depending on the bacterial origin of LPS and the presence or absence of platelets. Our findings suggest that LPS sensing by neutrophils may be a critical determinant for restricting NET release to certain Gram-negative bacteria only, which in turn may be crucial for minimizing unnecessary NET-associated immunopathology.
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Affiliation(s)
- Elmar Pieterse
- Department of Nephrology, Radboud University Medical Center , Nijmegen , Netherlands
| | - Nils Rother
- Department of Nephrology, Radboud University Medical Center , Nijmegen , Netherlands
| | - Cansu Yanginlar
- Department of Nephrology, Radboud University Medical Center , Nijmegen , Netherlands
| | - Luuk B Hilbrands
- Department of Nephrology, Radboud University Medical Center , Nijmegen , Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud University Medical Center , Nijmegen , Netherlands
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618
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Konig MF, Andrade F. A Critical Reappraisal of Neutrophil Extracellular Traps and NETosis Mimics Based on Differential Requirements for Protein Citrullination. Front Immunol 2016; 7:461. [PMID: 27867381 PMCID: PMC5095114 DOI: 10.3389/fimmu.2016.00461] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/14/2016] [Indexed: 12/18/2022] Open
Abstract
NETosis, an antimicrobial form of neutrophil cell death, is considered a primary source of citrullinated autoantigens in rheumatoid arthritis (RA) and immunogenic DNA in systemic lupus erythematosus (SLE). Activation of the citrullinating enzyme peptidylarginine deiminase type 4 (PAD4) is believed to be essential for neutrophil extracellular trap (NET) formation and NETosis. PAD4 is therefore viewed as a promising therapeutic target to inhibit the formation of NETs in both diseases. In this review, we examine the evidence for PAD4 activation during NETosis and provide experimental data to suggest that protein citrullination is not a universal feature of NETs. We delineate two distinct biological processes, leukotoxic hypercitrullination (LTH) and defective mitophagy, which have been erroneously classified as “NETosis.” While these NETosis mimics share morphological similarities with NETosis (i.e., extracellular DNA release), they are biologically distinct. As such, these processes can be readily classified by their stimuli, activation of distinct biochemical pathways, the presence of hypercitrullination, and antimicrobial effector function. NETosis is an antimicrobial form of cell death that is NADPH oxidase-dependent and not associated with hypercitrullination. In contrast, LTH is NADPH oxidase-independent and not bactericidal. Rather, LTH represents a bacterial strategy to achieve immune evasion. It is triggered by pore-forming pathways and equivalent signals that cumulate in calcium-dependent hyperactivation of PADs, protein hypercitrullination, and neutrophil death. The generation of citrullinated autoantigens in RA is likely driven by LTH, but not NETosis. Mitochondrial DNA (mtDNA) expulsion, the result of a constitutive defect in mitophagy, represents a second NETosis mimic. In the presence of interferon-α and immune complexes, this process can generate highly interferogenic oxidized mtDNA, which has previously been mistaken for NETosis in SLE. Distinguishing NETosis from LTH and defective mitophagy is paramount to understanding the role of neutrophil damage in immunity and the pathogenesis of human diseases. This provides a framework to design specific inhibitors of these distinct biological processes in human disease.
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Affiliation(s)
- Maximilian F Konig
- Division of Rheumatology, Johns Hopkins University School of Medicine , Baltimore, MD , USA
| | - Felipe Andrade
- Division of Rheumatology, Johns Hopkins University School of Medicine , Baltimore, MD , USA
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619
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Bernut A, Nguyen-Chi M, Halloum I, Herrmann JL, Lutfalla G, Kremer L. Mycobacterium abscessus-Induced Granuloma Formation Is Strictly Dependent on TNF Signaling and Neutrophil Trafficking. PLoS Pathog 2016; 12:e1005986. [PMID: 27806130 PMCID: PMC5091842 DOI: 10.1371/journal.ppat.1005986] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 10/10/2016] [Indexed: 01/08/2023] Open
Abstract
Mycobacterium abscessus is considered the most common respiratory pathogen among the rapidly growing non-tuberculous mycobacteria. Infections with M. abscessus are increasingly found in patients with chronic lung diseases, especially cystic fibrosis, and are often refractory to antibiotic therapy. M. abscessus has two morphotypes with distinct effects on host cells and biological responses. The smooth (S) variant is recognized as the initial airway colonizer while the rough (R) is known to be a potent inflammatory inducer associated with invasive disease, but the underlying immunopathological mechanisms of the infection remain unsolved. We conducted a comparative stepwise dissection of the inflammatory response in S and R pathogenesis by monitoring infected transparent zebrafish embryos. Loss of TNFR1 function resulted in increased mortality with both variants, and was associated with unrestricted intramacrophage bacterial growth and decreased bactericidal activity. The use of transgenic zebrafish lines harboring fluorescent macrophages and neutrophils revealed that neutrophils, like macrophages, interact with M. abscessus at the initial infection sites. Impaired TNF signaling disrupted the IL8-dependent neutrophil mobilization, and the defect in neutrophil trafficking led to the formation of aberrant granulomas, extensive mycobacterial cording, unrestricted bacterial growth and subsequent larval death. Our findings emphasize the central role of neutrophils for the establishment and maintenance of the protective M. abscessus granulomas. These results also suggest that the TNF/IL8 inflammatory axis is necessary for protective immunity against M. abscessus and may be of clinical relevance to explain why immunosuppressive TNF therapy leads to the exacerbation of M. abscessus infections. The incidence of non-tuberculous mycobacterial infections has recently increased and has even surpassed tuberculosis as a public health concern in many developed countries. These infections require long treatment regimens that are often unsuccessful. Among these, Mycobacterium abscessus has emerged as perhaps the most difficult-to-manage pathogen, especially in cystic fibrosis patients. Unfortunately, very little is known regarding the contributions of the pro-inflammatory and innate immune responses during M. abscessus infection. Here, we exploited the transparency of zebrafish embryos to study, at high resolution, the interactions of M. abscessus with macrophages and neutrophils, and found that both cell types are required to control the infection. We also describe the dramatic consequences of impaired TNF/IL8 immunity on the outcome of the infection. Most importantly, by tracking the dynamics of neutrophil mobilization, we demonstrated the crucial role of these cells in the formation and integrity of protective granulomas. Together, our data provide a significant advance in deciphering the immunopathology of M. abscessus infection, which is particularly relevant for understanding the exquisite vulnerability of cystic fibrosis patients to this bacterium.
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Affiliation(s)
- Audrey Bernut
- Centre d’études d’agents Pathogènes et Biotechnologies pour la Santé, FR3689, CNRS, Univ Montpellier, Montpellier, France
| | | | - Iman Halloum
- Centre d’études d’agents Pathogènes et Biotechnologies pour la Santé, FR3689, CNRS, Univ Montpellier, Montpellier, France
| | - Jean-Louis Herrmann
- UMR1173, INSERM, Université de Versailles St Quentin, Montigny le Bretonneux, France
| | | | - Laurent Kremer
- Centre d’études d’agents Pathogènes et Biotechnologies pour la Santé, FR3689, CNRS, Univ Montpellier, Montpellier, France
- INSERM, CPBS, Montpellier, France
- * E-mail:
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620
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Hosseinzadeh A, Thompson PR, Segal BH, Urban CF. Nicotine induces neutrophil extracellular traps. J Leukoc Biol 2016; 100:1105-1112. [PMID: 27312847 PMCID: PMC5069087 DOI: 10.1189/jlb.3ab0815-379rr] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 05/20/2016] [Accepted: 05/30/2016] [Indexed: 01/09/2023] Open
Abstract
NETs serve to ensnare and kill microbial pathogens. However, NETs can at the same time contribute to tissue damage and excessive inflammation. Nicotine is a major toxic agent and has been associated with exacerbated inflammatory diseases. The current study aimed at investigating the role of nicotine, the addictive component of tobacco and electronic cigarettes, on triggering NET formation. We report that nicotine induces neutrophils to release NETs in a dose-dependent manner. Nicotine-induced NET formation is mediated via nicotine acetylcholine receptors, depends on Akt and PAD4 activation, but is Nox2-independent, as demonstrated by pharmacological inhibition of Nox2 and by use of Nox2-deficient mouse neutrophils. These findings demonstrate that nicotine induces NETs, which may in turn contribute to smoking-related diseases.
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Affiliation(s)
- Ava Hosseinzadeh
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå, Sweden
- Laboratory for Molecular Infection Medicine, Umeå, Sweden (MIMS)
| | - Paul R Thompson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester Massachusetts, USA
| | - Brahm H Segal
- Department of Medicine, Roswell Park Cancer Institute, Buffalo, New York, USA
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
- Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Constantin F Urban
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden;
- Umeå Centre for Microbial Research (UCMR), Umeå, Sweden
- Laboratory for Molecular Infection Medicine, Umeå, Sweden (MIMS)
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621
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Singh A, Lelis F, Braig S, Schäfer I, Hartl D, Rieber N. Differential Regulation of Myeloid-Derived Suppressor Cells by Candida Species. Front Microbiol 2016; 7:1624. [PMID: 27790210 PMCID: PMC5061774 DOI: 10.3389/fmicb.2016.01624] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/29/2016] [Indexed: 12/25/2022] Open
Abstract
Myeloid-derived suppressor cells (MDSCs) are innate immune cells characterized by their ability to suppress T-cell responses. Recently, we demonstrated that the human-pathogenic fungi Candida albicans and Aspergillus fumigatus induced a distinct subset of neutrophilic MDSCs. To dissect Candida-mediated MDSC induction in more depth, we studied the relative efficacy of different pathogenic non-albicans Candida species to induce and functionally modulate neutrophilic MDSCs, including C. glabrata, C. parapsilosis, C. dubliniensis, and C. krusei. Our data demonstrate that the extent of MDSC generation is largely dependent on the Candida species with MDSCs induced by C. krusei and C. glabrata showing a higher suppressive activity compared to MDSCs induced by C. albicans. In summary, these studies show that fungal MDSC induction is differentially regulated at the species level and differentially affects effector T-cell responses.
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Affiliation(s)
- Anurag Singh
- University Children's Hospital and Interdisciplinary Center for Infectious Diseases, University of Tübingen Tübingen, Germany
| | - Felipe Lelis
- University Children's Hospital and Interdisciplinary Center for Infectious Diseases, University of Tübingen Tübingen, Germany
| | - Stefanie Braig
- University Children's Hospital and Interdisciplinary Center for Infectious Diseases, University of Tübingen Tübingen, Germany
| | - Iris Schäfer
- University Children's Hospital and Interdisciplinary Center for Infectious Diseases, University of Tübingen Tübingen, Germany
| | - Dominik Hartl
- University Children's Hospital and Interdisciplinary Center for Infectious Diseases, University of Tübingen Tübingen, Germany
| | - Nikolaus Rieber
- University Children's Hospital and Interdisciplinary Center for Infectious Diseases, University of TübingenTübingen, Germany; Department of Pediatrics, Kinderklinik München Schwabing, StKM GmbH und Klinikum rechts der Isar, Technische Universität MünchenMunich, Germany
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622
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Chen GY, Li Z, Duarte JN, Esteban A, Cheloha RW, Theile CS, Fink GR, Ploegh HL. Rapid capture and labeling of cells on single domain antibodies-functionalized flow cell. Biosens Bioelectron 2016; 89:789-794. [PMID: 27816596 DOI: 10.1016/j.bios.2016.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/01/2016] [Accepted: 10/05/2016] [Indexed: 01/13/2023]
Abstract
Current techniques to characterize leukocyte subgroups in blood require long sample preparation times and sizable sample volumes. A simplified method for leukocyte characterization using smaller blood volumes would thus be useful in diagnostic settings. Here we describe a flow system comprised of two functionalized graphene oxide (GO) surfaces that allow the capture of distinct leukocyte populations from small volumes blood using camelid single-domain antibodyfragments (VHHs) as capture agents. We used site-specifically labeled leukocytes to detect and identify cells exposed to fungal challenge. Combining the chemical and optical properties of GO with the versatility of the VHH scaffold in the context of a flow system provides a quick and efficient method for the capture and characterization of functional leukocytes.
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Affiliation(s)
- Guan-Yu Chen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Institute of Biomedical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan; Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Zeyang Li
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Joao N Duarte
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | | | - Ross W Cheloha
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | | | - Gerald R Fink
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hidde L Ploegh
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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623
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Sin YW, Newman C, Dugdale HL, Buesching C, Mannarelli ME, Annavi G, Burke T, Macdonald DW. No Compensatory Relationship between the Innate and Adaptive Immune System in Wild-Living European Badgers. PLoS One 2016; 11:e0163773. [PMID: 27695089 PMCID: PMC5047587 DOI: 10.1371/journal.pone.0163773] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/14/2016] [Indexed: 11/19/2022] Open
Abstract
The innate immune system provides the primary vertebrate defence system against pathogen invasion, but it is energetically costly and can have immune pathological effects. A previous study in sticklebacks found that intermediate major histocompatibility complex (MHC) diversity correlated with a lower leukocyte coping capacity (LCC), compared to individuals with fewer, or many, MHC alleles. The organization of the MHC genes in mammals, however, differs to the highly duplicated MHC genes in sticklebacks by having far fewer loci. Using European badgers (Meles meles), we therefore investigated whether innate immune activity, estimated functionally as the ability of an individual’s leukocytes to produce a respiratory burst, was influenced by MHC diversity. We also investigated whether LCC was influenced by factors such as age-class, sex, body condition, season, year, neutrophil and lymphocyte counts, and intensity of infection with five different pathogens. We found that LCC was not associated with specific MHC haplotypes, MHC alleles, or MHC diversity, indicating that the innate immune system did not compensate for the adaptive immune system even when there were susceptible MHC alleles/haplotypes, or when the MHC diversity was low. We also identified a seasonal and annual variation of LCC. This temporal variation of innate immunity was potentially due to physiological trade-offs or temporal variation in pathogen infections. The innate immunity, estimated as LCC, does not compensate for MHC diversity suggests that the immune system may function differently between vertebrates with different MHC organizations, with implications for the evolution of immune systems in different taxa.
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Affiliation(s)
- Yung Wa Sin
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney House, Abingdon Road, Tubney, Abingdon, Oxfordshire, OX13 5QL, United Kingdom
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, United States of America
- * E-mail:
| | - Chris Newman
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney House, Abingdon Road, Tubney, Abingdon, Oxfordshire, OX13 5QL, United Kingdom
| | - Hannah L. Dugdale
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, PO Box 11103, 9700 CC, Groningen, Netherlands
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Christina Buesching
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney House, Abingdon Road, Tubney, Abingdon, Oxfordshire, OX13 5QL, United Kingdom
| | - Maria-Elena Mannarelli
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, United Kingdom
| | - Geetha Annavi
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney House, Abingdon Road, Tubney, Abingdon, Oxfordshire, OX13 5QL, United Kingdom
- Faculty of Science, Department of Biology, University of Putra Malaysia, UPM 43400, Serdang, Selangor, Malaysia
| | - Terry Burke
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - David W. Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney House, Abingdon Road, Tubney, Abingdon, Oxfordshire, OX13 5QL, United Kingdom
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624
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Nauseef WM, Kubes P. Pondering neutrophil extracellular traps with healthy skepticism. Cell Microbiol 2016; 18:1349-57. [PMID: 27470975 PMCID: PMC5025378 DOI: 10.1111/cmi.12652] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 12/12/2022]
Abstract
The authors engage in a dialogue that evaluates critically the state of the study of neutrophil extracellular traps (NETs), a phenomenon currently the object of considerable interest, with the goal of identifying those aspects that merit clarification in order to assign the process its proper place in our current understanding of cell biology. Since the seminal observations in the Zychlinsky laboratory that described the extrusion of filaments of nuclear DNA associated with histones and granule proteins from neutrophils stimulated in vitro, many investigators have examined the phenomenon of NET formation in numerous and diverse settings. However, an overview of work in this rapidly growing field prompts several fundamental questions about NETs, including their precise composition, the mechanisms by which they arise, their clinical relevance, and the interrelationship of those observed in vitro and in vivo. In this discussion, the authors challenge interpretation of data from some experimental settings and provide recommendations for specific studies that would address the concerns raised, improve understanding of the biological relevance of NETs, and strengthen the field.
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Affiliation(s)
- William M Nauseef
- Inflammation Program and Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, and Veterans Administration Medical Center, Iowa City, Iowa, 52240, USA.
| | - Paul Kubes
- Department of Physiology and Pharmacology, Immunology Research Group, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, T2N 4N1, Canada.
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625
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The Role of Phagocytes and NETs in Dermatophytosis. Mycopathologia 2016; 182:263-272. [PMID: 27659806 DOI: 10.1007/s11046-016-0069-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 09/15/2016] [Indexed: 02/03/2023]
Abstract
Innate immunity is the host first line of defense against pathogens. However, only in recent years, we are beginning to better understand the ways it operates. A key player is this branch of the immune response that are the phagocytes, as macrophages, dendritic cells and neutrophils. These cells act as sentinels, employing specialized receptors in the sensing of invaders and host injury, and readily responding to them by production of inflammatory mediators. They afford protection not only by ingesting and destroying pathogens, but also by providing a suitable biochemical environment that shapes the adaptive response. In this review, we aim to present a broad perspective about the role of phagocytes in dermatophytosis, focusing on the mechanisms possibly involved in protective and non-protective responses. A full understanding of how phagocytes fit in the pathogenesis of these infections may open the venue for the development of new and more effective therapeutic approaches.
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626
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Schönrich G, Raftery MJ. Neutrophil Extracellular Traps Go Viral. Front Immunol 2016; 7:366. [PMID: 27698656 PMCID: PMC5027205 DOI: 10.3389/fimmu.2016.00366] [Citation(s) in RCA: 182] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/05/2016] [Indexed: 12/14/2022] Open
Abstract
Neutrophils are the most numerous immune cells. Their importance as the first line of defense against bacterial and fungal pathogens is well described. In contrast, the role of neutrophils in controlling viral infections is less clear. Bacterial and fungal pathogens can stimulate neutrophils extracellular traps (NETs) in a process called NETosis. Although NETosis has previously been described as a special form of programmed cell death, there are forms of NET production that do not end with the demise of neutrophils. As an end result of NETosis, genomic DNA complexed with microbicidal proteins is expelled from neutrophils. These structures can kill pathogens or at least prevent their local spread within host tissue. On the other hand, disproportionate NET formation can cause local or systemic damage. Only recently, it was recognized that viruses can also induce NETosis. In this review, we discuss the mechanisms by which NETs are produced in the context of viral infection and how this may contribute to both antiviral immunity and immunopathology. Finally, we shed light on viral immune evasion mechanisms targeting NETs.
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Affiliation(s)
- Günther Schönrich
- Institute of Medical Virology, Helmut-Ruska-Haus, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Martin J Raftery
- Institute of Medical Virology, Helmut-Ruska-Haus, Charité - Universitätsmedizin Berlin , Berlin , Germany
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627
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O'Brien XM, Reichner JS. Neutrophil Integrins and Matrix Ligands and NET Release. Front Immunol 2016; 7:363. [PMID: 27698655 PMCID: PMC5027203 DOI: 10.3389/fimmu.2016.00363] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/02/2016] [Indexed: 12/23/2022] Open
Abstract
Neutrophils are motile and responsive to tissue injury and infection. As neutrophils emigrate from the bloodstream and migrate toward a site of affliction, they encounter the tissue extracellular matrix (ECM) and thereby engage integrins. Our laboratory studies the neutrophilic response to the fungal pathogen Candida albicans either in the filamentous state of the microbe or to the purified pathogen-associated molecular pattern, β-glucan. We have gained an appreciation for the role of integrins in regulating the neutrophil anti-Candida response and how the presence or absence of ECM can drive experimental outcome. The β2 integrin CR3 (complement receptor 3; αMβ2; Mac-1; CD11b/CD18) plays an important role in fungal recognition by its ability to bind β-glucan at a unique lectin-like domain. The presence of ECM differentially regulates essential neutrophil anti-fungal functions, including chemotaxis, respiratory burst, homotypic aggregation, and the release of neutrophil extracellular traps (NETs). We have shown that NET release to C. albicans hyphae or immobilized β-glucan occurs rapidly and without the requirement for respiratory burst on ECM. This is in contrast to the more frequently reported mechanisms of NETosis to other pathogens without the context of ECM, which occur after a prolonged lag period and require respiratory burst. As expected for an ECM-dependent phenotype, NETosis and other neutrophil functions are dependent on specific integrins. The focus of this review is the role of ECM ligation by neutrophil integrins as it pertains to host defense functions with an emphasis on lessons we have learned studying the anti-Candida response of human neutrophils.
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Affiliation(s)
- Xian M O'Brien
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI, USA; Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Jonathan S Reichner
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, RI, USA; Warren Alpert Medical School, Brown University, Providence, RI, USA
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628
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The Extracellular Matrix of Candida albicans Biofilms Impairs Formation of Neutrophil Extracellular Traps. PLoS Pathog 2016; 12:e1005884. [PMID: 27622514 PMCID: PMC5021349 DOI: 10.1371/journal.ppat.1005884] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/21/2016] [Indexed: 12/31/2022] Open
Abstract
Neutrophils release extracellular traps (NETs) in response to planktonic C. albicans. These complexes composed of DNA, histones, and proteins inhibit Candida growth and dissemination. Considering the resilience of Candida biofilms to host defenses, we examined the neutrophil response to C. albicans during biofilm growth. In contrast to planktonic C. albicans, biofilms triggered negligible release of NETs. Time lapse imaging confirmed the impairment in NET release and revealed neutrophils adhering to hyphae and migrating on the biofilm. NET inhibition depended on an intact extracellular biofilm matrix as physical or genetic disruption of this component resulted in NET release. Biofilm inhibition of NETosis could not be overcome by protein kinase C activation via phorbol myristate acetate (PMA) and was associated with suppression of neutrophil reactive oxygen species (ROS) production. The degree of impaired NET release correlated with resistance to neutrophil attack. The clinical relevance of the role for extracellular matrix in diminishing NET production was corroborated in vivo using a rat catheter model. The C. albicans pmr1Δ/Δ, defective in production of matrix mannan, appeared to elicit a greater abundance of NETs by scanning electron microscopy imaging, which correlated with a decreased fungal burden. Together, these findings show that C. albicans biofilms impair neutrophil response through an inhibitory pathway induced by the extracellular matrix.
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629
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Li X, Cullere X, Nishi H, Saggu G, Durand E, Mansour MK, Tam JM, Song XY, Lin X, Vyas JM, Mayadas T. PKC-δ activation in neutrophils promotes fungal clearance. J Leukoc Biol 2016; 100:581-8. [PMID: 26965632 PMCID: PMC6608027 DOI: 10.1189/jlb.4a0915-405r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/02/2016] [Accepted: 02/17/2016] [Indexed: 12/18/2022] Open
Abstract
The C-type lectin receptor dectin-1 and the integrin Mac-1 have key roles in controlling fungal infection. Here, we demonstrate that dectin-1- and Mac-1-induced activation of protein kinase Cδ in neutrophils, independent of the Card9 adaptor, is required for reactive oxygen species production and for intracellular killing upon Candida albicans uptake. Protein kinase Cδ was also required for zymosan-induced cytokine generation in neutrophils. In macrophages, protein kinase Cδ deficiency prevented fungi-induced reactive oxygen species generation but had no effect on activation of TGF-β-activated kinase-1, an effector of Card9, or nuclear factor κB activation, nor did it affect phagolysosomal maturation, autophagy, or intracellular C. albicans killing. In vivo, protein kinase Cδ-deficient mice were highly susceptible to C. albicans and Aspergillus fumigatus infection, which was partially rescued with adoptively transferred wild-type neutrophils. Thus, protein kinase Cδ activation downstream of dectin-1 and Mac-1 has an important role in neutrophil, but not macrophage, functions required for host defense against fungal pathogens.
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Affiliation(s)
- Xun Li
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Department of Laboratory Medicine, The First Affiliated Hospital, Medical College of Xiamen University, Xiamen, Fujian, China
| | - Xavier Cullere
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Hiroshi Nishi
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Gurpanna Saggu
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Enrique Durand
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Michael K Mansour
- Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Jenny M Tam
- Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Xiu-Yu Song
- Department of Laboratory Medicine, The First Affiliated Hospital, Medical College of Xiamen University, Xiamen, Fujian, China
| | - Xin Lin
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jatin M Vyas
- Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Tanya Mayadas
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA;
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630
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Yang H, Biermann MH, Brauner JM, Liu Y, Zhao Y, Herrmann M. New Insights into Neutrophil Extracellular Traps: Mechanisms of Formation and Role in Inflammation. Front Immunol 2016; 7:302. [PMID: 27570525 PMCID: PMC4981595 DOI: 10.3389/fimmu.2016.00302] [Citation(s) in RCA: 194] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 07/26/2016] [Indexed: 02/05/2023] Open
Abstract
Recent data suggest that NETosis plays a crucial role in the innate immune response and disturbs the homeostasis of the immune system. NETosis is a form of neutrophil-specific cell death characterized by the release of large web-like structures referred to as neutrophil extracellular traps (NETs). NETs are composed of DNA strands associated with histones and decorated with about 20 different proteins, including neutrophil elastase, myeloperoxidase, cathepsin G, proteinase 3, high mobility group protein B1, and LL37. Reportedly, NETosis can be induced by several microbes, and particulate matter including sterile stimuli, via distinct cellular mechanisms. Meanwhile, suicidal NETosis and vital NETosis are controversial. As we enter the second decade of research on NETosis, we have partly understood NETs as double-edged swords of innate immunity. In this review, we will discuss the mechanisms of NETosis, its antimicrobial action, and role in autoimmune diseases, as well as the relatively new field of NET-associated mitochondrial DNA.
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Affiliation(s)
- Hang Yang
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University , Chengdu, Sichuan , China
| | - Mona Helena Biermann
- Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Jan Markus Brauner
- Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
| | - Yi Liu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University , Chengdu, Sichuan , China
| | - Yi Zhao
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University , Chengdu, Sichuan , China
| | - Martin Herrmann
- Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) , Erlangen , Germany
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631
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Crosby HA, Kwiecinski J, Horswill AR. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:1-41. [PMID: 27565579 DOI: 10.1016/bs.aambs.2016.07.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion.
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Affiliation(s)
- H A Crosby
- University of Iowa, Iowa City, IA, United States
| | - J Kwiecinski
- University of Iowa, Iowa City, IA, United States
| | - A R Horswill
- University of Iowa, Iowa City, IA, United States
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632
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Hosseini R, Lamers GEM, Soltani HM, Meijer AH, Spaink HP, Schaaf MJM. Efferocytosis and extrusion of leukocytes determine the progression of early mycobacterial pathogenesis. J Cell Sci 2016; 129:3385-95. [PMID: 27469488 DOI: 10.1242/jcs.135194] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/25/2016] [Indexed: 12/12/2022] Open
Abstract
Macrophages and neutrophils are the first responders to invading pathogens and contribute strongly to the host defense against intracellular pathogens. The collective interplay and dynamic interactions between these leukocytes are to a large extent not understood. In the present study, we have investigated their role using a combination of confocal laser-scanning and electron microscopy in a zebrafish model for tuberculosis, a local Mycobacterium marinum infection in the tissue of the larval tail fin. Our results show that neutrophils are efficient in phagocytosis of mycobacteria and that they contribute largely to their dissemination. Macrophages appear to play a major role in efferocytosis, phagocytosis of dead cells that contain bacterial content. Phagocytic cells with large bacterial aggregates are formed that can be extruded out of the tissue after cell death. Alternatively, these excessively infected cells can undergo necrosis leading to immediate recruitment of surrounding leukocytes and subsequent phagocytosis of released bacteria. Our data show that these necrotic burst events result in progression of the infection, whereas extrusion abates the infection.
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Affiliation(s)
- Rohola Hosseini
- Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Gerda E M Lamers
- Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Hiwa M Soltani
- Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Annemarie H Meijer
- Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Herman P Spaink
- Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Marcel J M Schaaf
- Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
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633
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Weckmann M, Schultheiss C, Hollaender A, Bobis I, Rupp J, Kopp MV. Treatment with rhDNase in patients with cystic fibrosis alters in-vitro CHIT-1 activity of isolated leucocytes. Clin Exp Immunol 2016; 185:382-91. [PMID: 27324468 DOI: 10.1111/cei.12827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2016] [Indexed: 11/28/2022] Open
Abstract
Recent data suggest a possible relationship between cystic fibrosis (CF) pharmacotherapy, Aspergillus fumigatus colonization (AC) and/or allergic bronchopulmonary aspergillosis (ABPA). The aim of this study was to determine if anti-fungal defence mechanisms are influenced by CF pharmacotherapy, i.e. if (1) neutrophils form CF and non-CF donors differ in their ability to produce chitotriosidase (CHIT-1); (2) if incubation of isolated neutrophils with azithromycin, salbutamol, prednisolone or rhDNase might influence the CHIT-1 activity; and (3) if NETosis and neutrophil killing efficiency is influenced by rhDNase. Neutrophils were isolated from the blood of CF patients (n = 19; mean age 26·8 years or healthy, non-CF donors (n = 20; 38·7 years) and stimulated with phorbol-12-myristate-13-acetate (PMA), azithromycin, salbutamol, prednisolone or rhDNase. CHIT-1 enzyme activity was measured with a fluorescent substrate. NETosis was induced by PMA and neutrophil killing efficiency was assessed by a hyphae recovery assay. Neutrophil CHIT-1 activity was comparable in the presence or absence of PMA stimulation in both CF and non-CF donors. PMA stimulation and preincubation with rhDNase increased CHIT-1 activity in culture supernatants from non-CF and CF donors. However, this increase was significant in non-CF donors but not in CF patients (P < 0·05). RhDNase reduced the number of NETs in PMA-stimulated neutrophils and decreased the killing efficiency of leucocytes in our in-vitro model. Azithromycin, salbutamol or prednisolone had no effect on CHIT-1 activity. Stimulation of isolated leucocytes with PMA and treatment with rhDNase interfered with anti-fungal defence mechanisms. However, the impact of our findings for treatment in CF patients needs to be proved in a clinical cohort.
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Affiliation(s)
- M Weckmann
- Department of Pediatric Allergy and Pulmonology, Clinic of Pediatrics UKSH, University of Luebeck, Luebeck.,Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL)
| | - C Schultheiss
- Department of Pediatric Allergy and Pulmonology, Clinic of Pediatrics UKSH, University of Luebeck, Luebeck.,Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL)
| | - A Hollaender
- Department of Pediatric Allergy and Pulmonology, Clinic of Pediatrics UKSH, University of Luebeck, Luebeck.,Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL)
| | - I Bobis
- Clinic of Internal Medicine, UKSH, University of Kiel, Kiel
| | - J Rupp
- Department of Molecular and Clinical Infectious Diseases, University of Luebeck, Luebeck, Germany
| | - M V Kopp
- Department of Pediatric Allergy and Pulmonology, Clinic of Pediatrics UKSH, University of Luebeck, Luebeck.,Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL)
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634
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Hoffmann JHO, Enk AH. Neutrophil extracellular traps in dermatology: Caught in the NET. J Dermatol Sci 2016; 84:3-10. [PMID: 27481818 DOI: 10.1016/j.jdermsci.2016.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 07/03/2016] [Accepted: 07/04/2016] [Indexed: 01/21/2023]
Abstract
Neutrophil, or polymorphonuclear granulocytes (PMN) constitute the most abundant type of leucocytes in peripheral human blood. One of the major advances in the last decade was the discovery of neutrophil extracellular trap (NET) formation: a process by which neutrophils externalize web-like chromatin strands decorated with antimicrobial peptides. These structures were soon implicated in immune defense and auto-immunity alike and now link neutrophils to the pathogenesis of a variety of diseases of dermatological relevance. Currently, NET formation is mainly subdivided into suicidal and vital NETosis. Controversy exists regarding the capacity of NETs to kill pathogens, and little is known about the way NETs are formed in vivo. Here, we discuss the current terminology, methods for NET quantification, pathways leading to NET formation, and the role of NETs in systemic and cutaneous immune defense and auto-immunity, with a focus on psoriasis and systemic lupus erythematosus.
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Affiliation(s)
| | - Alexander H Enk
- Department of Dermatology, University of Heidelberg, Germany
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635
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Carestia A, Kaufman T, Schattner M. Platelets: New Bricks in the Building of Neutrophil Extracellular Traps. Front Immunol 2016; 7:271. [PMID: 27458459 PMCID: PMC4933697 DOI: 10.3389/fimmu.2016.00271] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/28/2016] [Indexed: 12/22/2022] Open
Abstract
In addition to being key elements in hemostasis and thrombosis, platelets have an important role in the inflammatory and innate immune response. This activity is associated with their capability to recognize pathogens through the expression of toll-like receptors, the secretion of various cytokines, chemokines, and growth factors stored within their granules, and the expression of cell adhesion molecules that allows interaction with other immune cells, mainly neutrophils and monocytes. As part of the first line of defense, neutrophils control invading pathogens by phagocytosis, the release of antimicrobial proteins during degranulation, or through the formation of web-like structures named neutrophil extracellular traps (NETs). NETs are formed by chromatin, proteases, and antimicrobial proteins, and their main function is to trap and kill bacteria, virus, and fungi, avoiding their dissemination. Besides microorganisms, NET formation is also triggered by proinflammatory molecules and platelets. The uncontrolled formation of NETs might exert tissue damage and has been involved in a pathogenic mechanism of autoimmune and prothrombotic clinical conditions. In this review, we discuss the role of platelets in NET generation highlighting the mediators, stimuli, and molecular mechanisms involved in this phenomenon, both in human and murine models.
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Affiliation(s)
- Agostina Carestia
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine-CONICET, National Academy of Medicine , Buenos Aires , Argentina
| | - Tomas Kaufman
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine-CONICET, National Academy of Medicine , Buenos Aires , Argentina
| | - Mirta Schattner
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine-CONICET, National Academy of Medicine , Buenos Aires , Argentina
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636
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A dinuclear ruthenium(II) complex as turn-on luminescent probe for hypochlorous acid and its application for in vivo imaging. Sci Rep 2016; 6:29065. [PMID: 27356618 PMCID: PMC4928191 DOI: 10.1038/srep29065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/14/2016] [Indexed: 12/30/2022] Open
Abstract
A dinuclear ruthenium(II) complex Ruazo was designed and synthesized, in which oxidative cyclization of the azo and o-amino group was employed for the detection of hypochlorous acid (HClO) in aqueous solution. The non-emissive Ruazo formed highly luminescent triazole-ruthenium(II) complex in presence of HClO and successfully imaged HClO in living cell and living mouse.
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637
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Far beyond Phagocytosis: Phagocyte-Derived Extracellular Traps Act Efficiently against Protozoan Parasites In Vitro and In Vivo. Mediators Inflamm 2016; 2016:5898074. [PMID: 27445437 PMCID: PMC4944069 DOI: 10.1155/2016/5898074] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/02/2016] [Accepted: 06/05/2016] [Indexed: 12/30/2022] Open
Abstract
Professional mononuclear phagocytes such as polymorphonuclear neutrophils (PMN), monocytes, and macrophages are considered as the first line of defence against invasive pathogens. The formation of extracellular traps (ETs) by activated mononuclear phagocytes is meanwhile well accepted as an effector mechanism of the early host innate immune response acting against microbial infections. Recent investigations showed evidence that ETosis is a widely spread effector mechanism in vertebrates and invertebrates being utilized to entrap and kill bacteria, fungi, viruses, and protozoan parasites. ETs are released in response to intact protozoan parasites or to parasite-specific antigens in a controlled cell death process. Released ETs consist of nuclear DNA as backbone adorned with histones, antimicrobial peptides, and phagocyte-specific granular enzymes thereby producing a sticky extracellular matrix capable of entrapping and killing pathogens. This review summarizes recent data on protozoa-induced ETosis. Special attention will be given to molecular mechanisms of protozoa-induced ETosis and on its consequences for the parasites successful reproduction and life cycle accomplishment.
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638
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Malachowa N, Kobayashi SD, Quinn MT, DeLeo FR. NET Confusion. Front Immunol 2016; 7:259. [PMID: 27446089 PMCID: PMC4923183 DOI: 10.3389/fimmu.2016.00259] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/17/2016] [Indexed: 12/17/2022] Open
Abstract
Neutrophils are arguably the most important white blood cell for defense against bacterial and fungal infections. These leukocytes are produced in high numbers on a daily basis in humans and are recruited rapidly to injured/infected tissues. Phagocytosis and subsequent intraphagosomal killing and digestion of microbes have historically been the accepted means by which neutrophils carry out their role in innate host defense. Indeed, neutrophils contain and produce numerous cytotoxic molecules, including antimicrobial peptides, proteases, and reactive oxygen species, that are highly effective at killing the vast majority of ingested microbes. On the other hand, it is these characteristics - high numbers and toxicity - that endow neutrophils with the potential to injure and destroy host tissues. This potential is borne out by many inflammatory processes and diseases. Therefore, it is not surprising that host mechanisms exist to control virtually all steps in the neutrophil activation process and to prevent unintended neutrophil activation and/or lysis during the resolution of inflammatory responses or during steady-state turnover. The notion that neutrophil extracellular traps (NETs) form by cytolysis as a standard host defense mechanism seems inconsistent with these aforementioned neutrophil "containment" processes. It is with this caveat in mind that we provide perspective on the role of NETs in human host defense and disease.
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Affiliation(s)
- Natalia Malachowa
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, MT , USA
| | - Scott D Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, MT , USA
| | - Mark T Quinn
- Department of Microbiology and Immunology, Montana State University , Bozeman, MT , USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, MT , USA
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639
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Abstract
Klebsiella pneumoniae causes a wide range of infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Historically, K. pneumoniae has caused serious infection primarily in immunocompromised individuals, but the recent emergence and spread of hypervirulent strains have broadened the number of people susceptible to infections to include those who are healthy and immunosufficient. Furthermore, K. pneumoniae strains have become increasingly resistant to antibiotics, rendering infection by these strains very challenging to treat. The emergence of hypervirulent and antibiotic-resistant strains has driven a number of recent studies. Work has described the worldwide spread of one drug-resistant strain and a host defense axis, interleukin-17 (IL-17), that is important for controlling infection. Four factors, capsule, lipopolysaccharide, fimbriae, and siderophores, have been well studied and are important for virulence in at least one infection model. Several other factors have been less well characterized but are also important in at least one infection model. However, there is a significant amount of heterogeneity in K. pneumoniae strains, and not every factor plays the same critical role in all virulent Klebsiella strains. Recent studies have identified additional K. pneumoniae virulence factors and led to more insights about factors important for the growth of this pathogen at a variety of tissue sites. Many of these genes encode proteins that function in metabolism and the regulation of transcription. However, much work is left to be done in characterizing these newly discovered factors, understanding how infections differ between healthy and immunocompromised patients, and identifying attractive bacterial or host targets for treating these infections.
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640
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Kenno S, Perito S, Mosci P, Vecchiarelli A, Monari C. Autophagy and Reactive Oxygen Species Are Involved in Neutrophil Extracellular Traps Release Induced by C. albicans Morphotypes. Front Microbiol 2016; 7:879. [PMID: 27375599 PMCID: PMC4896927 DOI: 10.3389/fmicb.2016.00879] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/25/2016] [Indexed: 12/31/2022] Open
Abstract
Neutrophil extracellular traps (NETs) are a combination of DNA fibers and granular enzymes, such as elastase and myeloperoxidase. In this study, we demonstrate that Candida albicans hyphal (CAH) cells and yeast (CAY) cells induce differential amounts, kinetics and mechanisms of NET release. CAH cells induced larger quantities of NET compared to CAY cells and can stimulate rapid NET formation up to 4 h of incubation. CAY cells are, also, able to induce rapid NET formation, but this ability was lost at 4 h. Both reactive oxygen species (ROS) and autophagy are implicated in NET induced by CAH and CAY cells, but with a time-different participation of these two mechanisms. In particular, in the early phase (15 min) CAH cells stimulate NET via autophagy, but not via ROS, while CAY cells induce NET via both autophagy and ROS. At 4 h, only CAH cells stimulate NET formation using autophagy as well as ROS. Finally, we demonstrate that NET release, in response to CAH cells, involves NF-κB activation and is strongly implicated in hyphal destruction.
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Affiliation(s)
- Samyr Kenno
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University Innsbruck, Austria
| | - Stefano Perito
- Microbiology Section, Department of Experimental Medicine, University of Perugia Perugia, Italy
| | - Paolo Mosci
- Internal Medicine, Department of Veterinary Medicine, University of Perugia Perugia, Italy
| | - Anna Vecchiarelli
- Microbiology Section, Department of Experimental Medicine, University of Perugia Perugia, Italy
| | - Claudia Monari
- Microbiology Section, Department of Experimental Medicine, University of Perugia Perugia, Italy
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641
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Domingo-Gonzalez R, Martínez-Colón GJ, Smith AJ, Smith CK, Ballinger MN, Xia M, Murray S, Kaplan MJ, Yanik GA, Moore BB. Inhibition of Neutrophil Extracellular Trap Formation after Stem Cell Transplant by Prostaglandin E2. Am J Respir Crit Care Med 2016; 193:186-97. [PMID: 26417909 DOI: 10.1164/rccm.201501-0161oc] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
RATIONALE Autologous and allogeneic hematopoietic stem cell transplant (HSCT) patients are susceptible to pulmonary infections, including bacterial pathogens, even after hematopoietic reconstitution. We previously reported that murine bone marrow transplant (BMT) neutrophils overexpress cyclooxygenase-2, overproduce prostaglandin E2 (PGE2), and exhibit defective intracellular bacterial killing. Neutrophil extracellular traps (NETs) are DNA structures that capture and kill extracellular bacteria and other pathogens. OBJECTIVES To determine whether NETosis was defective after transplant and if so, whether this was regulated by PGE2 signaling. METHODS Neutrophils isolated from mice and humans (both control and HSCT subjects) were analyzed for NETosis in response to various stimuli in the presence or absence of PGE2 signaling modifiers. MEASUREMENTS AND MAIN RESULTS NETs were visualized by immunofluorescence or quantified by Sytox Green fluorescence. Treatment of BMT or HSCT neutrophils with phorbol 12-myristate 13-acetate or rapamycin resulted in reduced NET formation relative to control cells. NET formation after BMT was rescued both in vitro and in vivo with cyclooxygenase inhibitors. Additionally, the EP2 receptor antagonist (PF-04418948) or the EP4 antagonist (AE3-208) restored NET formation in neutrophils isolated from BMT mice or HSCT patients. Exogenous PGE2 treatment limited NETosis of neutrophils collected from normal human volunteers and naive mice in an exchange protein activated by cAMP- and protein kinase A-dependent manner. CONCLUSIONS Our results suggest blockade of the PGE2-EP2 or EP4 signaling pathway restores NETosis after transplantation. Furthermore, these data provide the first description of a physiologic inhibitor of NETosis.
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Affiliation(s)
| | | | | | - Carolyne K Smith
- 1 Immunology Graduate Program.,3 Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland; and
| | - Megan N Ballinger
- 4 Pulmonary, Allergy, Critical Care and Sleep Division, Department of Internal Medicine, The Ohio State University, Columbus, Ohio
| | - Meng Xia
- 5 Biostatistics Department, School of Public Health
| | - Susan Murray
- 5 Biostatistics Department, School of Public Health
| | - Mariana J Kaplan
- 3 Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland; and
| | - Gregory A Yanik
- 6 Department of Pediatrics, Division of Hematology-Oncology, Medical School
| | - Bethany B Moore
- 7 Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, and.,8 Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan
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642
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Obar JJ, Hohl TM, Cramer RA. New advances in invasive aspergillosis immunobiology leading the way towards personalized therapeutic approaches. Cytokine 2016; 84:63-73. [PMID: 27253487 DOI: 10.1016/j.cyto.2016.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 05/16/2016] [Indexed: 01/07/2023]
Abstract
Invasive aspergillosis (IA) remains a devastating disease in immune compromised patients despite significant advances in our understanding of fungal virulence and host defense mechanisms. In this review, we summarize important research advances in the fight against IA with particular focus on early events in the interactions between Aspergillus fumigatus and the host that occur in the respiratory tract. Advances in understanding mechanisms of immune effector cell recruitment, antifungal effector mechanisms, and how the dynamic host-fungal interaction alters the local microenvironment to effect outcomes are highlighted. These advances illustrate exciting new therapeutic opportunities, but also emphasize the importance of understanding each unique fungus-host interaction for improving patient outcomes.
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Affiliation(s)
- Joshua J Obar
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States.
| | - Tobias M Hohl
- Infectious Disease Service, Department of Medicine, Sloan Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, NY, United States; Immunology Program, Sloan Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, NY, United States.
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States.
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643
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Hopke A, Nicke N, Hidu EE, Degani G, Popolo L, Wheeler RT. Neutrophil Attack Triggers Extracellular Trap-Dependent Candida Cell Wall Remodeling and Altered Immune Recognition. PLoS Pathog 2016; 12:e1005644. [PMID: 27223610 PMCID: PMC4880299 DOI: 10.1371/journal.ppat.1005644] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/28/2016] [Indexed: 01/09/2023] Open
Abstract
Pathogens hide immunogenic epitopes from the host to evade immunity, persist and cause infection. The opportunistic human fungal pathogen Candida albicans, which can cause fatal disease in immunocompromised patient populations, offers a good example as it masks the inflammatory epitope β-glucan in its cell wall from host recognition. It has been demonstrated previously that β-glucan becomes exposed during infection in vivo but the mechanism behind this exposure was unknown. Here, we show that this unmasking involves neutrophil extracellular trap (NET) mediated attack, which triggers changes in fungal cell wall architecture that enhance immune recognition by the Dectin-1 β-glucan receptor in vitro. Furthermore, using a mouse model of disseminated candidiasis, we demonstrate the requirement for neutrophils in triggering these fungal cell wall changes in vivo. Importantly, we found that fungal epitope unmasking requires an active fungal response in addition to the stimulus provided by neutrophil attack. NET-mediated damage initiates fungal MAP kinase-driven responses, particularly by Hog1, that dynamically relocalize cell wall remodeling machinery including Chs3, Phr1 and Sur7. Neutrophil-initiated cell wall disruptions augment some macrophage cytokine responses to attacked fungi. This work provides insight into host-pathogen interactions during disseminated candidiasis, including valuable information about how the C. albicans cell wall responds to the biotic stress of immune attack. Our results highlight the important but underappreciated concept that pattern recognition during infection is dynamic and depends on the host-pathogen dialog. Opportunistic fungal infections, including those caused by C. albicans, have emerged as a significant global health burden and the disseminated form of these infections still have unacceptably high mortality rates despite modern antifungal treatments. The fungal cell wall controls its interaction with the host environment and immune recognition, although cell wall dynamics during infection are poorly understood. C. albicans organizes its cell wall to mask the inflammatory β-glucan as a form of immune evasion and it is known that during infection this β-glucan becomes exposed. Here, we investigated how β-glucan becomes exposed and discovered a dynamic interaction where host NETs provoke an active fungal response that disrupts cell wall architecture and unmasks β-glucan. We revealed an unexpected level of local fungal cell wall dynamics in response to immune mediated stress, suggesting this may represent a model that can be leveraged to identify novel drug targets. Our results highlight the understudied concept that the cell wall is a dynamic landscape during infection and can be influenced by the host.
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Affiliation(s)
- Alex Hopke
- Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States of America
| | - Nadine Nicke
- Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States of America
| | - Erica E. Hidu
- Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States of America
| | - Genny Degani
- Department of Biosciences, University of Milan, Milan, Italy
| | - Laura Popolo
- Department of Biosciences, University of Milan, Milan, Italy
| | - Robert T. Wheeler
- Molecular and Biomedical Sciences, University of Maine, Orono, Maine, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine, United States of America
- * E-mail:
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644
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Kashem SW, Kaplan DH. Skin Immunity to Candida albicans. Trends Immunol 2016; 37:440-450. [PMID: 27178391 DOI: 10.1016/j.it.2016.04.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 12/20/2022]
Abstract
Candida albicans is a dimorphic commensal fungus that colonizes healthy human skin, mucosa, and the reproductive tract. C. albicans is also a predominantly opportunistic fungal pathogen, leading to disease manifestations such as disseminated candidiasis and chronic mucocutaneous candidiasis (CMC). The differing host susceptibilities for the sites of C. albicans infection have revealed tissue compartmentalization with tailoring of immune responses based on the site of infection. Furthermore, extensive studies of host genetics in rare cases of CMC have identified conserved genetic pathways involved in immune recognition and the response to the extracellular pathogen. We focus here on human and mouse skin as a site of C. albicans infection, and we review established and newly discovered insights into the cellular pathways that promote cutaneous antifungal immunity.
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Affiliation(s)
- Sakeen W Kashem
- Department of Dermatology, Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel H Kaplan
- Departments of Dermatology and Immunology, University of Pittsburgh, Pittsburgh, PA 15216, USA.
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645
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The Staphylococcus aureus Global Regulator MgrA Modulates Clumping and Virulence by Controlling Surface Protein Expression. PLoS Pathog 2016; 12:e1005604. [PMID: 27144398 PMCID: PMC4856396 DOI: 10.1371/journal.ppat.1005604] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/07/2016] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is a human commensal and opportunistic pathogen that causes devastating infections in a wide range of locations within the body. One of the defining characteristics of S. aureus is its ability to form clumps in the presence of soluble fibrinogen, which likely has a protective benefit and facilitates adhesion to host tissue. We have previously shown that the ArlRS two-component regulatory system controls clumping, in part by repressing production of the large surface protein Ebh. In this work we show that ArlRS does not directly regulate Ebh, but instead ArlRS activates expression of the global regulator MgrA. Strains lacking mgrA fail to clump in the presence of fibrinogen, and clumping can be restored to an arlRS mutant by overexpressing either arlRS or mgrA, indicating that ArlRS and MgrA constitute a regulatory pathway. We used RNA-seq to show that MgrA represses ebh, as well as seven cell wall-associated proteins (SraP, Spa, FnbB, SasG, SasC, FmtB, and SdrD). EMSA analysis showed that MgrA directly represses expression of ebh and sraP. Clumping can be restored to an mgrA mutant by deleting the genes for Ebh, SraP and SasG, suggesting that increased expression of these proteins blocks clumping by steric hindrance. We show that mgrA mutants are less virulent in a rabbit model of endocarditis, and virulence can be partially restored by deleting the genes for the surface proteins ebh, sraP, and sasG. While mgrA mutants are unable to clump, they are known to have enhanced biofilm capacity. We demonstrate that this increase in biofilm formation is partially due to up-regulation of SasG, a surface protein known to promote intercellular interactions. These results confirm that ArlRS and MgrA constitute a regulatory cascade, and that they control expression of a number of genes important for virulence, including those for eight large surface proteins. Staphylococcus causes a wide range of diseases, ranging from skin infections to deadly invasive condition like endocarditis, septicemia, osteomyelitis, and pneumonia. In this work we examine the ArlRS two-component regulatory system, which controls interactions with the host plasma protein fibrinogen. S. aureus normally forms large aggregates called clumps in the presence of fibrinogen, but the arlRS mutant is unable to clump. We demonstrate that ArlRS activates expression of the DNA-binding protein MgrA, and that mgrA is also required for clumping. Transcriptional analysis of an mgrA mutant shows that MgrA regulates expression of eight surface proteins. Expression of these surface proteins affects clumping, possibly by physically interfering with fibrinogen binding. Strains lacking mgrA are less virulent in an endocarditis model, and virulence can be partially restored by deleting genes for three of these surface proteins. An mgrA mutant is also known to have enhanced biofilm formation, and we show that this is partially due to increased production of one of these surface proteins. These results demonstrate that ArlRS and MgrA constitute a regulatory cascade in S. aureus that is crucial for pathogenesis and may be a good candidate to target for drug development.
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646
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Pionnier N, Brotin E, Karadjian G, Hemon P, Gaudin-Nomé F, Vallarino-Lhermitte N, Nieguitsila A, Fercoq F, Aknin ML, Marin-Esteban V, Chollet-Martin S, Schlecht-Louf G, Bachelerie F, Martin C. Neutropenic Mice Provide Insight into the Role of Skin-Infiltrating Neutrophils in the Host Protective Immunity against Filarial Infective Larvae. PLoS Negl Trop Dis 2016; 10:e0004605. [PMID: 27111140 PMCID: PMC4844152 DOI: 10.1371/journal.pntd.0004605] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 03/12/2016] [Indexed: 01/06/2023] Open
Abstract
Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs. Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4+/1013). We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin. Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4+/1013 mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3). This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice. Indeed, the parasitic success in Cxcr4+/1013 mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3. Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin. Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET). This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host. Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis. Filariases are chronic debilitating diseases caused by parasitic nematodes affecting more than 150 million people worldwide. None of the current drugs are selective, neither able to eliminate the parasites nor to prevent new infections once the drug pressure has waned. Therefore, blocking the entry and the migration of the infective larvae (L3) could be an efficient way to control the infection. In the present study we investigated the early interaction between the host and the L. sigmodontis murine filariasis with a focus on the neutrophils in the innate host responses. We uncovered a key role of neutrophils in the control of infection provided by the CXCR4-gain-of-function mice (Cxcr4+/1013) that display a blood neutropenia as well as an accumulation of skin-infiltrating neutrophils. Overall, we reveal that in the early phase of filariasis, i.e. after L3 are delivered into the skin and before they reach their site for reproduction, neutrophils are critical elements of the host innate protective response arsenal. A better understanding of their indirect and/or effector role(s) may provide mechanistic clues to host factors implicated in parasitic nematode entry and potentially lead to the identification of new drug targets.
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Affiliation(s)
- Nicolas Pionnier
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Emilie Brotin
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Gregory Karadjian
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Patrice Hemon
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
- US31-UMS3679 -Plateforme PLAIMMO, Institut Paris-Saclay d’Innovation Thérapeutique (IPSIT), Inserm, CNRS, Univ Paris-Sud, Université Paris-Saclay, Clamart, France
| | - Françoise Gaudin-Nomé
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
- US31-UMS3679 -Plateforme PLAIMMO, Institut Paris-Saclay d’Innovation Thérapeutique (IPSIT), Inserm, CNRS, Univ Paris-Sud, Université Paris-Saclay, Clamart, France
| | - Nathaly Vallarino-Lhermitte
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Adélaïde Nieguitsila
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Frédéric Fercoq
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
| | - Marie-Laure Aknin
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Viviana Marin-Esteban
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Sylvie Chollet-Martin
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Géraldine Schlecht-Louf
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
| | - Françoise Bachelerie
- UMR996—Inflammation, Chemokines and Immunopathology, Inserm, Univ Paris-Sud, Université Paris-Saclay, Clamart and Châtenay-Malabry, France
- * E-mail: (FB); (CM)
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d’Histoire Naturelle, CNRS; CP52, Paris, France
- * E-mail: (FB); (CM)
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Glass KA, Longley SJ, Bliss JM, Shaw SK. Protection of Candida parapsilosis from neutrophil killing through internalization by human endothelial cells. Virulence 2016; 6:504-14. [PMID: 26039751 DOI: 10.1080/21505594.2015.1042643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Candida parapsilosis is a fungal pathogen that is associated with hematogenously disseminated disease in premature neonates, acutely ill or immunocompromised patients. In cell culture, C. parapsilosis cells are actively and avidly endocytosed by endothelial cells via actin polymerization mediated by N-WASP. Here we present evidence that C. parapsilosis that were internalized by endothelial cells remained alive, and avoided being acidified or otherwise damaged via the host cell. Internalized fungal cells reproduced intracellularly and eventually burst out of the host endothelial cell. When neutrophils were added to endothelium and C. parapsilosis, they patrolled the endothelial surface and efficiently killed most adherent fungal cells prior to endocytosis. But after endocytosis by endothelial cells, internalized fungal cells evaded neutrophil killing. Silencing endothelial N-WASP blocked endocytosis of C. parapsilosis and left fungal cells stranded on the cell surface, where they were susceptible to neutrophil killing. These observations suggest that for C. parapsilosis to escape from the bloodstream, fungi may adhere to and be internalized by endothelial cells before being confronted and phagocytosed by a patrolling leukocyte. Once internalized by endothelial cells, C. parapsilosis may safely replicate to cause further rounds of infection. Immunosurveillance of the intravascular lumen by leukocytes crawling on the endothelial surface and rapid killing of adherent yeast may play a major role in controlling C. parapsilosis dissemination and infected endothelial cells may be a significant reservoir for fungal persistence.
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Affiliation(s)
- Kyle A Glass
- a Department of Pediatrics; Women & Infants Hospital of Rhode Island ; Providence , RI , USA
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648
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Trevijano-Contador N, Rueda C, Zaragoza O. Fungal morphogenetic changes inside the mammalian host. Semin Cell Dev Biol 2016; 57:100-109. [PMID: 27101887 DOI: 10.1016/j.semcdb.2016.04.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/12/2016] [Accepted: 04/15/2016] [Indexed: 10/21/2022]
Abstract
One of the main features of the majority of pathogenic fungi is the ability to switch between different types of morphological forms. These changes include the transition between cells of different shapes (such as the formation of pseudohyphae and hyphae), or the massive growth of the blastoconidia and formation of titan cells. Morphological changes occur during infection, and there is extensive evidence that they play a key role in processes required for disease, such as adhesion, invasion and dissemination, immune recognition evasion, and phagocytosis avoidance. In the present review, we will provide an overview of how morphological transitions contribute to the development of fungal disease, with special emphasis in two cases: Candida albicans as an example of yeast that switches between blastoconidia and filaments, and Cryptococcus neoformans as an example of a fungus that changes the size without modifying the shape of the cell.
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Affiliation(s)
- Nuria Trevijano-Contador
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo Km2, Majadahonda 28220, Madrid, Spain
| | - Cristina Rueda
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo Km2, Majadahonda 28220, Madrid, Spain
| | - Oscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo Km2, Majadahonda 28220, Madrid, Spain.
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649
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Alhamdi Y, Toh CH. The role of extracellular histones in haematological disorders. Br J Haematol 2016; 173:805-11. [PMID: 27062156 DOI: 10.1111/bjh.14077] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 02/05/2016] [Accepted: 02/06/2016] [Indexed: 12/22/2022]
Abstract
Over the past decades, chromosomal alterations have been extensively investigated for their pathophysiological relevance in haematological malignancies. In particular, epigenetic modifications of intra-nuclear histones are now known as key regulators of healthy cell cycles that have also evolved into novel therapeutic targets for certain blood cancers. Thus, for most haematologists, histones are DNA-chained proteins that are buried deep within chromatin. However, the plot has deepened with recent revelations on the function of histones when unchained and released extracellularly upon cell death or from activated neutrophils as part of neutrophil extracellular traps (NETs). Extracellular histones and NETs are increasingly recognized for profound cytotoxicity and pro-coagulant effects. This article highlights the importance of recognizing this new paradigm of extracellular histones as a key player in host defence through its damage-associated molecular patterns, which could translate into novel diagnostic and therapeutic biomarkers in various haematological and critical disorders.
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Affiliation(s)
- Yasir Alhamdi
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Cheng-Hock Toh
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.,Roald Dahl Haemostasis & Thrombosis Centre, Royal Liverpool University Hospital, Liverpool, UK
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650
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Schneider AE, Sándor N, Kárpáti É, Józsi M. Complement factor H modulates the activation of human neutrophil granulocytes and the generation of neutrophil extracellular traps. Mol Immunol 2016; 72:37-48. [PMID: 26938503 DOI: 10.1016/j.molimm.2016.02.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 02/18/2016] [Accepted: 02/20/2016] [Indexed: 01/27/2023]
Abstract
Factor H (FH) is a major inhibitor of the alternative pathway of complement activation in plasma and on certain host surfaces. In addition to being a complement regulator, FH can bind to various cells via specific receptors, including binding to neutrophil granulocytes through complement receptor type 3 (CR3; CD11b/CD18), and modulate their function. The cellular roles of FH are, however, poorly understood. Because neutrophils are important innate immune cells in inflammatory processes and the host defense against pathogens, we aimed at studying the effects of FH on various neutrophil functions, including the generation of extracellular traps. FH co-localized with CD11b on the surface of neutrophils isolated from peripheral blood of healthy individuals, and cell-bound FH retained its cofactor activity and enhanced C3b degradation. Soluble FH supported neutrophil migration and immobilized FH induced cell spreading. In addition, immobilized but not soluble FH enhanced IL-8 release from neutrophils. FH alone did not trigger the cells to produce neutrophil extracellular traps (NETs), but NET formation induced by PMA and by fibronectin plus fungal β-glucan were inhibited by immobilized, but not by soluble, FH. Moreover, in parallel with NET formation, immobilized FH also inhibited the production of reactive oxygen species induced by PMA and by fibronectin plus β-glucan. Altogether, these data indicate that FH has multiple regulatory roles on neutrophil functions. While it can support the recruitment of neutrophils, FH may also exert anti-inflammatory effects and influence local inflammatory and antimicrobial reactions, and reduce tissue damage by modulating NET formation.
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Affiliation(s)
- Andrea E Schneider
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Noémi Sándor
- MTA-ELTE Immunology Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Éva Kárpáti
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Mihály Józsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary.
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