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Goh KGK, Desai D, Thapa R, Prince D, Acharya D, Sullivan MJ, Ulett GC. An opportunistic pathogen under stress: how Group B Streptococcus responds to cytotoxic reactive species and conditions of metal ion imbalance to survive. FEMS Microbiol Rev 2024; 48:fuae009. [PMID: 38678005 PMCID: PMC11098048 DOI: 10.1093/femsre/fuae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/26/2024] [Accepted: 04/16/2024] [Indexed: 04/29/2024] Open
Abstract
Group B Streptococcus (GBS; also known as Streptococcus agalactiae) is an opportunistic bacterial pathogen that causes sepsis, meningitis, pneumonia, and skin and soft tissue infections in neonates and healthy or immunocompromised adults. GBS is well-adapted to survive in humans due to a plethora of virulence mechanisms that afford responses to support bacterial survival in dynamic host environments. These mechanisms and responses include counteraction of cell death from exposure to excess metal ions that can cause mismetallation and cytotoxicity, and strategies to combat molecules such as reactive oxygen and nitrogen species that are generated as part of innate host defence. Cytotoxicity from reactive molecules can stem from damage to proteins, DNA, and membrane lipids, potentially leading to bacterial cell death inside phagocytic cells or within extracellular spaces within the host. Deciphering the ways in which GBS responds to the stress of cytotoxic reactive molecules within the host will benefit the development of novel therapeutic and preventative strategies to manage the burden of GBS disease. This review summarizes knowledge of GBS carriage in humans and the mechanisms used by the bacteria to circumvent killing by these important elements of host immune defence: oxidative stress, nitrosative stress, and stress from metal ion intoxication/mismetallation.
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Affiliation(s)
- Kelvin G K Goh
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Devika Desai
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Ruby Thapa
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Darren Prince
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Dhruba Acharya
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Matthew J Sullivan
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Glen C Ulett
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
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2
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Darwitz BP, Genito CJ, Thurlow LR. Triple threat: how diabetes results in worsened bacterial infections. Infect Immun 2024:e0050923. [PMID: 38526063 DOI: 10.1128/iai.00509-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024] Open
Abstract
Diabetes mellitus, characterized by impaired insulin signaling, is associated with increased incidence and severity of infections. Various diabetes-related complications contribute to exacerbated bacterial infections, including hyperglycemia, innate immune cell dysfunction, and infection with antibiotic-resistant bacterial strains. One defining symptom of diabetes is hyperglycemia, resulting in elevated blood and tissue glucose concentrations. Glucose is the preferred carbon source of several bacterial pathogens, and hyperglycemia escalates bacterial growth and virulence. Hyperglycemia promotes specific mechanisms of bacterial virulence known to contribute to infection chronicity, including tissue adherence and biofilm formation. Foot infections are a significant source of morbidity in individuals with diabetes and consist of biofilm-associated polymicrobial communities. Bacteria perform complex interspecies behaviors conducive to their growth and virulence within biofilms, including metabolic cross-feeding and altered phenotypes more tolerant to antibiotic therapeutics. Moreover, the metabolic dysfunction caused by diabetes compromises immune cell function, resulting in immune suppression. Impaired insulin signaling induces aberrations in phagocytic cells, which are crucial mediators for controlling and resolving bacterial infections. These aberrancies encompass altered cytokine profiles, the migratory and chemotactic mechanisms of neutrophils, and the metabolic reprogramming required for the oxidative burst and subsequent generation of bactericidal free radicals. Furthermore, the immune suppression caused by diabetes and the polymicrobial nature of the diabetic infection microenvironment may promote the emergence of novel strains of multidrug-resistant bacterial pathogens. This review focuses on the "triple threat" linked to worsened bacterial infections in individuals with diabetes: (i) altered nutritional availability in diabetic tissues, (ii) diabetes-associated immune suppression, and (iii) antibiotic treatment failure.
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Affiliation(s)
- Benjamin P Darwitz
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Christopher J Genito
- Division of Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill Adams School of Dentistry, Chapel Hill, North Carolina, USA
| | - Lance R Thurlow
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
- Division of Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill Adams School of Dentistry, Chapel Hill, North Carolina, USA
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Melbouci D, Haidar Ahmad A, Decker P. Neutrophil extracellular traps (NET): not only antimicrobial but also modulators of innate and adaptive immunities in inflammatory autoimmune diseases. RMD Open 2023; 9:e003104. [PMID: 37562857 PMCID: PMC10423839 DOI: 10.1136/rmdopen-2023-003104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/14/2023] [Indexed: 08/12/2023] Open
Abstract
Polymorphonuclear neutrophils (PMN) represent one of the first lines of defence against invading pathogens and are the most abundant leucocytes in the circulation. Generally described as pro-inflammatory cells, recent data suggest that PMN also have immunomodulatory capacities. In response to certain stimuli, activated PMN expel neutrophil extracellular traps (NET), structures made of DNA and associated proteins. Although originally described as an innate immune mechanism fighting bacterial infection, NET formation (or probably rather an excess of NET together with impaired clearance of NET) may be deleterious. Indeed, NET have been implicated in the development of several inflammatory and autoimmune diseases as rheumatoid arthritis or systemic lupus erythematosus, as well as fibrosis or cancer. They have been suggested as a source of (neo)autoantigens or regulatory proteins like proteases or to act as a physical barrier. Different mechanisms of NET formation have been described, leading to PMN death or not, depending on the stimulus. Interestingly, NET may be both pro-inflammatory and anti-inflammatory and this probably partly depends on the mechanism, and thus the stimuli, triggering NET formation. Within this review, we will describe the pro-inflammatory and anti-inflammatory activities of NET and especially how NET may modulate immune responses.
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Affiliation(s)
- Dyhia Melbouci
- Inserm UMR 1125, Li2P, Université Sorbonne Paris Nord-Campus de Bobigny, Bobigny, Île-de-France, France
| | - Ahmad Haidar Ahmad
- Inserm UMR 1125, Li2P, Université Sorbonne Paris Nord-Campus de Bobigny, Bobigny, Île-de-France, France
| | - Patrice Decker
- Inserm UMR 1125, Li2P, Université Sorbonne Paris Nord-Campus de Bobigny, Bobigny, Île-de-France, France
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4
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Affiliation(s)
- Rebecca A. Keogh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, Colorado, United States of America
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, Colorado, United States of America
- * E-mail:
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Qian M, Xu K, Zhang M, Niu J, Zhao T, Wang X, Jia Y, Li J, Yu Z, He L, Li Y, Wu T, Wei Y, Chen J, Chen S, Zhang C, Liao C. 5'-Nucleotidase is dispensable for the growth of Salmonella Typhimurium but inhibits the bactericidal activity of macrophage extracellular traps. Arch Microbiol 2022; 205:20. [PMID: 36482126 DOI: 10.1007/s00203-022-03353-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022]
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a zoonotic pathogen that causes severe gastroenteritis. The 5'-nucleotidases of pathogens can dephosphorylate adenosine phosphates, boost adenosine levels and suppress the pro-inflammatory immune response. In our previous study, an extracellular nuclease, 5'-nucleotidase, was identified in the extracellular proteins of S. Typhimurium. However, the nuclease activity and the function of the 5'-nucleotidase of S. Typhimurium have not been explored. In the present study, deletion of the 5'-nucleotidase gene is dispensable for S. Typhimurium growth, even under environmental stress. Fluorescence microscopy revealed that the 5'-nucleotidase mutant induced more macrophage extracellular traps (METs) than the wild type did. Furthermore, recombinant 5'-nucleotidase protein (r5Nuc) could degrade λDNA, and the nuclease activity of r5Nuc was optimum at 37 °C and pH 6.0-7.0. The Mg2+ enhanced the nuclease activity of r5Nuc, whereas Zn2+ inhibited it. Meanwhile, deletion of the 5'-nucleotidase gene increased the bactericidal activity of METs, and r5Nuc could degrade METs and inhibit the bactericidal activity of METs. In conclusion, S. Typhimurium growth was independent of 5'-nucleotidase, but the nuclease activity of 5'-nucleotidase assisted S. Typhimurium to evade macrophage-mediated extracellular killing through degrading METs.
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Affiliation(s)
- Man Qian
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Ke Xu
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Mengke Zhang
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Junhui Niu
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Tianxiang Zhao
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Xiaoli Wang
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471023, People's Republic of China
| | - Yanyan Jia
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Jing Li
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Zuhua Yu
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Lei He
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Yinju Li
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Tingcai Wu
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Ying Wei
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Jian Chen
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Songbiao Chen
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China
| | - Chunjie Zhang
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China.
| | - Chengshui Liao
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, People's Republic of China.
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de Jesus Gonzalez-Contreras F, Zarate X. Neutrophil extracellular traps: Modulation mechanisms by pathogens. Cell Immunol 2022; 382:104640. [PMID: 36413806 DOI: 10.1016/j.cellimm.2022.104640] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/03/2022] [Accepted: 11/05/2022] [Indexed: 11/11/2022]
Abstract
Neutrophils, as innate effector cells, play an essential role in the containment and elimination of pathogens. Among the main neutrophil mechanisms use for these processes is the release of neutrophil extracellular traps (NETs), which consist of decondensed DNA decorated with various cytoplasmic proteins. NETs' principal role is the trapping and elimination of infectious agents; therefore, the formation of NETs is regulated by bacteria, fungi, parasites, and viruses through different mechanisms: the presence of virulence factors (adhered or secreted), microbial load, size of the microorganism, and even due to other immune cells activation (mainly platelets). This review summarizes the significant aspects that contribute to NETs modulation by pathogens and their components, and the effect NETs have on these pathogens as a cellular defense mechanism.
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Affiliation(s)
| | - Xristo Zarate
- Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Av. Universidad s/n, San Nicolas de los Garza 66455, NL, Mexico
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Keogh RA, Haeberle AL, Langouët-Astrié CJ, Kavanaugh JS, Schmidt EP, Moore GD, Horswill AR, Doran KS. Group B Streptococcus adaptation promotes survival in a hyperinflammatory diabetic wound environment. SCIENCE ADVANCES 2022; 8:eadd3221. [PMID: 36367946 PMCID: PMC9651866 DOI: 10.1126/sciadv.add3221] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Diabetic wounds have poor healing outcomes due to the presence of numerous pathogens and a dysregulated immune response. Group B Streptococcus (GBS) is commonly isolated from diabetic wound infections, but the mechanisms of GBS virulence during these infections have not been investigated. Here, we develop a murine model of GBS diabetic wound infection and, using dual RNA sequencing, demonstrate that GBS infection triggers an inflammatory response. GBS adapts to this hyperinflammatory environment by up-regulating virulence factors including those known to be regulated by the two-component system covRS, such as the surface protein pbsP, and the cyl operon, which is responsible for hemolysin/pigmentation production. We recover hyperpigmented/hemolytic GBS colonies from the murine diabetic wound, which we determined encode mutations in covR. We further demonstrate that GBS mutants in cylE and pbsP are attenuated in the diabetic wound. This foundational study provides insight into the pathogenesis of GBS diabetic wound infections.
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Affiliation(s)
- Rebecca A. Keogh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
| | - Amanda L. Haeberle
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
| | | | - Jeffrey S. Kavanaugh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
| | - Eric P. Schmidt
- Department of Medicine–Pulmonary Sciences and Critical Care, University of Colorado Anschutz, Aurora, CO, USA
| | - Garrett D. Moore
- Department of Orthopedics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
- Department of Veterans Affairs Eastern Colorado Healthcare System, Aurora, CO, USA
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz, Aurora, CO, USA
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8
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Kuryłek A, Stasiak M, Kern-Zdanowicz I. Virulence factors of Streptococcus anginosus - a molecular perspective. Front Microbiol 2022; 13:1025136. [PMID: 36386673 PMCID: PMC9643698 DOI: 10.3389/fmicb.2022.1025136] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/10/2022] [Indexed: 07/21/2023] Open
Abstract
Streptococcus anginosus together with S. constellatus and S. intermedius constitute the Streptococcus anginosus group (SAG), until recently considered to be benign commensals of the human mucosa isolated predominantly from oral cavity, but also from upper respiratory, intestinal, and urogenital tracts. For years the virulence potential of SAG was underestimated, mainly due to complications in correct species identification and their assignment to the physiological microbiota. Still, SAG representatives have been associated with purulent infections at oral and non-oral sites resulting in abscesses formation and empyema. Also, life threatening blood infections caused by SAG have been reported. However, the understanding of SAG as potential pathogen is only fragmentary, albeit certain aspects of SAG infection seem sufficiently well described to deserve a systematic overview. In this review we summarize the current state of knowledge of the S. anginosus pathogenicity factors and their mechanisms of action.
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9
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Zang X, Dang G, Cai Z, Shao M, Tang Y, Cao J, Cui Z, Liu S. Extracellular DNase MAP3916c attacks the neutrophil extracellular traps and is needed for Mycobacterium avium subsp. paratuberculosis virulence. Vet Microbiol 2022; 273:109529. [PMID: 35944391 DOI: 10.1016/j.vetmic.2022.109529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 11/27/2022]
Abstract
Extracellular DNases/nucleases are important virulence factors in many bacteria. However, no DNase/nucleases have been reported in Mycobacterium avium subsp. paratuberculosis (MAP), which is a pathogen of paratuberculosis. Genome analyses of MAP K-10 revealed that the map3916c gene putatively encodes a nuclease. In this study, we show that MAP3916c is an extracellular nonspecific DNase requiring a divalent cation, especially Mg2+. The optimum DNase activity of MAP3916c was exhibited at 41 °C and pH 9.0. Site-directed mutagenesis studies indicated that 125-Histidine is necessary for MAP3916c DNase activity. In addition, MAP3916c DNase could destroy the neutrophil extracellular traps (NETs) induced by Phorbol 12-myristate 13-acetate in vitro and degrade the NETs induced by MAP K-10 upon infection. Furthermore, MAP3916c DNase promoted the colonization of MAP K-10, induced the formation of granulomas in the liver and small intestine and promoted the release of IL-1β, IL-6 and TNF-α inflammatory cytokines during the infection of mice. These results indicated that MAP3916c is relevant to NETs escape and the pathogenicity of MAP. It also provides a basis for further study of the function of nuclease activity on the MAP immune evasion.
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Affiliation(s)
- Xinxin Zang
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China
| | - Guanghui Dang
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China
| | - Zhuming Cai
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China
| | - Mingzhu Shao
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China
| | - Yangyang Tang
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Jun Cao
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China
| | - Ziyin Cui
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China
| | - Siguo Liu
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin 150069, China.
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Liao C, Mao F, Qian M, Wang X. Pathogen-Derived Nucleases: An Effective Weapon for Escaping Extracellular Traps. Front Immunol 2022; 13:899890. [PMID: 35865526 PMCID: PMC9294136 DOI: 10.3389/fimmu.2022.899890] [Citation(s) in RCA: 7] [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: 03/19/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
Since the 2004 publication of the first study describing extracellular traps (ETs) from human neutrophils, several reports have shown the presence of ETs in a variety of different animals and plants. ETs perform two important functions of immobilizing and killing invading microbes and are considered a novel part of the phagocytosis-independent, innate immune extracellular defense system. However, several pathogens can release nucleases that degrade the DNA backbone of ETs, reducing their effectiveness and resulting in increased pathogenicity. In this review, we examined the relevant literature and summarized the results on bacterial and fungal pathogens and parasites that produce nucleases to evade the ET-mediated host antimicrobial mechanism.
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Affiliation(s)
- Chengshui Liao
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang, China
- *Correspondence: Chengshui Liao, ; Xiaoli Wang,
| | - Fuchao Mao
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang, China
- Animal Diseases and Public Health Engineering Research Center of Henan Province, Luoyang Vocational and Technical College, Luoyang, China
| | - Man Qian
- College of Animal Science and Technology/Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, Luoyang, China
| | - Xiaoli Wang
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, China
- *Correspondence: Chengshui Liao, ; Xiaoli Wang,
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Ma F, Yang S, Wang G, Zhou M, Zhang J, Deng B, Yin W, Wang H, Lu Y, Fan H. Effect of multiplicity of infection on the evasion of neutrophil killing by Streptococcus agalactiae isolated from clinical mastitis bovine. Vet Microbiol 2022; 270:109450. [PMID: 35580447 DOI: 10.1016/j.vetmic.2022.109450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/21/2022] [Accepted: 04/30/2022] [Indexed: 10/18/2022]
Abstract
Streptococcus agalactiae (S. agalactiae) causes intramammary infection in dairy cows. Increased neutrophils and a high bacterial load are important characteristics of bovine bacterial mastitis. We hypothesized that the multiplicity of infection (MOI) of S. agalactiae in bovine mastitis plays an important role in bacterial pathogenicity by modulating the neutrophil response to promote bacterial survival. Neutrophils from BALB/c mice were infected with the bovine mastitis isolate of S. agalactiae SAG-FX17 at various MOIs, and neutrophil responses were investigated. Infecting neutrophils with SAG-FX17 at an MOI of 1 induced reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) formation. Bacteria at an MOI of 10 suppressed neutrophil responses, including ROS bursts, NET formation, and cell necrosis, which are conducive to bacterial multiplication within 30 min postinfection. In addition, neutrophils are destroyed by SAG-FX17 at an MOI of 100 or greater. This study identified the MOIs related to the ROS and NET suppression caused by SAG-FX17, and the findings suggested that interventions to decrease bacterial loads before the MOI of 10 could be necessary and effective to harness the power of innate immune response to eliminate pathogens.
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Affiliation(s)
- Fang Ma
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Shifang Yang
- College of Veterinary Medicine, Nanjing Agriculture University, Nanjing, China
| | - Guangyu Wang
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, Jiangsu 210023, China
| | - Mingxu Zhou
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Jinqiu Zhang
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Bihua Deng
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Wenzhu Yin
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Haiyan Wang
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yu Lu
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agriculture University, Nanjing, China.
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Ma F, Yang S, Zhou M, Lu Y, Deng B, Zhang J, Fan H, Wang G. NADPH oxidase-derived reactive oxygen species production activates the ERK1/2 pathway in neutrophil extracellular traps formation by Streptococcus agalactiae isolated from clinical mastitis bovine. Vet Microbiol 2022; 268:109427. [PMID: 35405476 DOI: 10.1016/j.vetmic.2022.109427] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 03/08/2022] [Accepted: 04/01/2022] [Indexed: 11/29/2022]
Abstract
Streptococcus agalactiae (S. agalactiae) continues to be challenging for milk quality in some countries and leads to huge economic losses. A large number of neutrophils are recruited into inflammatory foci when S. agalactiae infection occurs, and most studies have focused on the interaction between neutrophil extracellular traps (NETs) and this bacterium in the context of human pathogenicity. However, there is little information on the NET formation mechanism induced by S. agalactiae in the context of bovine mastitis. Here, neutrophils isolated from BALB/c mice were infected with S. agalactiae SAG-FX17, and NET formation was evaluated. SAG-FX17 could induce NADPH oxidase-derived reactive oxygen species (NOX-ROS)-dependent NET formation, and 21.8% of bacteria could be eliminated by NETs via NET DNA and associated proteins. SAG-FX17 could induce the phosphorylation of p38 MAPK, ERK1/2 MAPK, and JNK/SAPK in neutrophils. However, only ERK1/2 MAPK was shown to play an important role in SAG-FX17-induced NET formation. Importantly, NOX-ROS production occurs upstream of ERK1/2 MAPK activation and then induces NET release. ERK1/2 MAPK phosphorylation can, in turn, enhance NOX-ROS generation, which further contributes to NET release and bacterial elimination. This study provides evidence of the molecular mechanism underlying serotype Ia S. agalactiae SAG-FX17-induced NET formation and the interaction between bacteria and NETs, and these findings will increase our knowledge about bacterial mastitis in dairy cattle and contribute to the prevention and clinical treatment of bovine mastitis.
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Affiliation(s)
- Fang Ma
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Nanjing 210014, China
| | - Shifang Yang
- College of Veterinary Medicine, Nanjing Agriculture University, Nanjing, China
| | - Mingxu Zhou
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yu Lu
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Bihua Deng
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Jinqiu Zhang
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agriculture University, Nanjing, China
| | - Guangyu Wang
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, Jiangsu 210023, China.
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13
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Furuta A, Brokaw A, Manuel G, Dacanay M, Marcell L, Seepersaud R, Rajagopal L, Adams Waldorf K. Bacterial and Host Determinants of Group B Streptococcal Infection of the Neonate and Infant. Front Microbiol 2022; 13:820365. [PMID: 35265059 PMCID: PMC8899651 DOI: 10.3389/fmicb.2022.820365] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/27/2022] [Indexed: 12/15/2022] Open
Abstract
Group B streptococci (GBS) are Gram-positive β-hemolytic bacteria that can cause serious and life-threatening infections in neonates manifesting as sepsis, pneumonia, meningitis, osteomyelitis, and/or septic arthritis. Invasive GBS infections in neonates in the first week of life are referred to as early-onset disease (EOD) and thought to be acquired by the fetus through exposure to GBS in utero or to vaginal fluids during birth. Late-onset disease (LOD) refers to invasive GBS infections between 7 and 89 days of life. LOD transmission routes are incompletely understood, but may include breast milk, household contacts, nosocomial, or community sources. Invasive GBS infections and particularly meningitis may result in significant neurodevelopmental injury and long-term disability that persists into childhood and adulthood. Globally, EOD and LOD occur in more than 300,000 neonates and infants annually, resulting in 90,000 infant deaths and leaving more than 10,000 infants with a lifelong disability. In this review, we discuss the clinical impact of invasive GBS neonatal infections and then summarize virulence and host factors that allow the bacteria to exploit the developing neonatal immune system and target organs. Specifically, we consider the mechanisms known to enable GBS invasion into the neonatal lung, blood vessels and brain. Understanding mechanisms of GBS invasion and pathogenesis relevant to infections in the neonate and infant may inform the development of therapeutics to prevent or mitigate injury, as well as improve risk stratification.
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Affiliation(s)
- Anna Furuta
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Alyssa Brokaw
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Gygeria Manuel
- Morehouse School of Medicine, Atlanta, GA, United States
| | - Matthew Dacanay
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Lauren Marcell
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Ravin Seepersaud
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States
| | - Kristina Adams Waldorf
- Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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14
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Garcia Gonzalez J, Hernandez FJ. Nuclease activity: an exploitable biomarker in bacterial infections. Expert Rev Mol Diagn 2022; 22:265-294. [PMID: 35240900 DOI: 10.1080/14737159.2022.2049249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION In the increasingly challenging field of clinical microbiology, diagnosis is a cornerstone whose accuracy and timing are crucial for the successful management, therapy, and outcome of infectious diseases. Currently employed biomarkers of infectious diseases define the scope and limitations of diagnostic techniques. As such, expanding the biomarker catalog is crucial to address unmet needs and bring about novel diagnostic functionalities and applications. AREAS COVERED This review describes the extracellular nucleases of 15 relevant bacterial pathogens and discusses the potential use of nuclease activity as a diagnostic biomarker. Articles were searched for in PubMed using terms: "nuclease", "bacteria", "nuclease activity" or "biomarker". For overview sections, original and review articles between 2000 and 2019 were searched for using terms: "infections", "diagnosis", "bacterial", "burden", "challenges". Informative articles were selected. EXPERT OPINION Using the catalytic activity of nucleases offers new possibilities compared to established biomarkers. Nucleic acid activatable reporters in combination with different transduction platforms and delivery methods can be used to detect disease-associated nuclease activity patterns in vitro and in vivo for prognostic and diagnostic applications. Even when these patterns are not obvious or of unknown etiology, screening platforms could be used to identify new disease reporters.
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Affiliation(s)
- Javier Garcia Gonzalez
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.,Wallenberg Centre for Molecular Medicine (WCMM), Linköping, Sweden.,Nucleic Acids Technologies Laboratory (NAT-lab), Linköping University, Linköping, Sweden
| | - Frank J Hernandez
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.,Wallenberg Centre for Molecular Medicine (WCMM), Linköping, Sweden.,Nucleic Acids Technologies Laboratory (NAT-lab), Linköping University, Linköping, Sweden
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15
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Polymorphonuclear Neutrophils in Rheumatoid Arthritis and Systemic Lupus Erythematosus: More Complicated Than Anticipated. IMMUNO 2022. [DOI: 10.3390/immuno2010007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Polymorphonuclear neutrophils (PMN) are the most abundant leucocytes in the circulation in humans. They represent a heterogeneous population exerting diverse functions through several activities. Usually described as typical pro-inflammatory cells, immunomodulatory properties of PMNs have been reported. Among others, once activated and depending on the stimulus, PMNs expel neutrophil extracellular traps (NET) in the extracellular space. NETs are complexes made of DNA and granule proteins representing an innate immune mechanism fighting infections. Nevertheless, an excess of NET formation might be involved in the development of inflammatory or autoimmune responses. Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two chronic, inflammatory, autoimmune diseases of unknown etiology and affecting mostly women. Several abnormal or non-classical functions of PMNs or PMN sub-populations have been described in SLE and RA. Particularly, NETs have been suggested to trigger pro-inflammatory responses by exposing pro-inflammatory mediators. Likewise, NETs may be the targets of autoantibodies or even might trigger the development of autoantibodies by exposing autoantigens. In the present review, we will summarize heterogeneous properties of human PMNs and we will discuss recent evidence linking PMNs and NETs to the pathogenesis of both SLE and RA.
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16
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Mechanisms of Acetoin Toxicity and Adaptive Responses in an Acetoin-Producing Species, Lactococcus lactis. Appl Environ Microbiol 2021; 87:e0107921. [PMID: 34613757 PMCID: PMC8612267 DOI: 10.1128/aem.01079-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Acetoin, 3-hydroxyl,2-butanone, is extensively used as a flavor additive in food products. This volatile compound is produced by the dairy bacterium Lactococcus lactis when aerobic respiration is activated by haem addition, and comprises ∼70% of carbohydrate degradation products. Here we investigate the targets of acetoin toxicity, and determine how acetoin impacts L. lactis physiology and survival. Acetoin caused damage to DNA and proteins, which related to reactivity of its keto group. Acetoin stress was reflected in proteome profiles, which revealed changes in lipid metabolic proteins. Acetoin provoked marked changes in fatty acid composition, with massive accumulation of cycC19:0 cyclopropane fatty acid at the expense of its unsaturated C18:1 fatty acid precursor. Deletion of the cfa gene, encoding the cycC19:0 synthase, sensitized cells to acetoin stress. Acetoin-resistant transposon mutagenesis revealed a hot spot in the high affinity phosphate transporter operon pstABCDEF, which is known to increase resistance to multiple stresses. This work reveals the causes and consequences of acetoin stress on L. lactis, and may facilitate control of lactic acid bacteria production in technological processes. IMPORTANCE Acetoin, 3-hydroxyl,2-butanone, has diverse uses in chemical industry, agriculture, and dairy industries as a volatile compound that generates aromas. In bacteria, it can be produced in high amount by Lactococcus lactis when it grows under aerobic respiration. However, acetoin production can be toxic and detrimental for growth and/or survival. Our results showed that it damages DNA and proteins via its keto group. We also showed that acetoin modifies membrane fatty acid composition with the production of cyclopropane C19:0 fatty acid at the expense of an unsaturated C18:1. We isolated mutants more resistant to acetoin than the wild-type strain. All of them mapped to a single locus pstABCDEF operon, suggesting a simple means to limit acetoin toxicity in dairy bacteria and to improve its production.
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17
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Mazzuoli MV, Daunesse M, Varet H, Rosinski-Chupin I, Legendre R, Sismeiro O, Gominet M, Kaminski PA, Glaser P, Chica C, Trieu-Cuot P, Firon A. The CovR regulatory network drives the evolution of Group B Streptococcus virulence. PLoS Genet 2021; 17:e1009761. [PMID: 34491998 PMCID: PMC8448333 DOI: 10.1371/journal.pgen.1009761] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/17/2021] [Accepted: 08/09/2021] [Indexed: 01/31/2023] Open
Abstract
Virulence of the neonatal pathogen Group B Streptococcus is under the control of the master regulator CovR. Inactivation of CovR is associated with large-scale transcriptome remodeling and impairs almost every step of the interaction between the pathogen and the host. However, transcriptome analyses suggested a plasticity of the CovR signaling pathway in clinical isolates leading to phenotypic heterogeneity in the bacterial population. In this study, we characterized the CovR regulatory network in a strain representative of the CC-17 hypervirulent lineage responsible of the majority of neonatal meningitis. Transcriptome and genome-wide binding analysis reveal the architecture of the CovR network characterized by the direct repression of a large array of virulence-associated genes and the extent of co-regulation at specific loci. Comparative functional analysis of the signaling network links strain-specificities to the regulation of the pan-genome, including the two specific hypervirulent adhesins and horizontally acquired genes, to mutations in CovR-regulated promoters, and to variability in CovR activation by phosphorylation. This regulatory adaptation occurs at the level of genes, promoters, and of CovR itself, and allows to globally reshape the expression of virulence genes. Overall, our results reveal the direct, coordinated, and strain-specific regulation of virulence genes by the master regulator CovR and suggest that the intra-species evolution of the signaling network is as important as the expression of specific virulence factors in the emergence of clone associated with specific diseases. Streptococcus agalactiae, commonly known as the Group B Streptococcus (GBS), is a commensal bacterium of the intestinal and vaginal tracts found in approximately 30% of healthy adults. However, GBS is also an opportunistic pathogen and the leading cause of neonatal invasive infections. Epidemiologic data have identified a particular GBS clone, designated the CC-17 hypervirulent clonal complex, as responsible for the overwhelming majority of neonatal meningitis. The hypervirulence of CC-17 has been linked to the expression of two specific surface proteins increasing their abilities to cross epithelial and endothelial barriers. In this study, we characterized the role of the major regulator of virulence gene expression, the CovR response regulator, in a representative hypervirulent strain. Transcriptome and genome-wide binding analysis reveal the architecture of the CovR signaling network characterized by the direct repression of a large array of virulence-associated genes, including the specific hypervirulent adhesins. Comparative analysis in a non-CC-17 wild type strain demonstrates a high level of plasticity of the regulatory network, allowing to globally reshape pathogen-host interaction. Overall, our results suggest that the intra-species evolution of the regulatory network is an important factor in the emergence of GBS clones associated with specific pathologies.
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Affiliation(s)
- Maria-Vittoria Mazzuoli
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
- Sorbonne Paris Cité, Université de Paris, Paris, France
| | - Maëlle Daunesse
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
| | - Hugo Varet
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Isabelle Rosinski-Chupin
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | - Rachel Legendre
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Odile Sismeiro
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
- Plate-forme Technologique Biomics—Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Myriam Gominet
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
| | - Pierre Alexandre Kaminski
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
| | - Philippe Glaser
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | - Claudia Chica
- Hub de Bioinformatique et Biostatistique—Département Biologie Computationnelle, Institut Pasteur, Paris, France
| | - Patrick Trieu-Cuot
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
| | - Arnaud Firon
- Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS UMR2001 Microbiologie Intégrative et Moléculaire, Institut Pasteur, Paris, France
- * E-mail:
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18
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NAD+ pool depletion as a signal for the Rex regulon involved in Streptococcus agalactiae virulence. PLoS Pathog 2021; 17:e1009791. [PMID: 34370789 PMCID: PMC8376106 DOI: 10.1371/journal.ppat.1009791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 08/19/2021] [Accepted: 07/08/2021] [Indexed: 12/16/2022] Open
Abstract
In many Gram-positive bacteria, the redox-sensing transcriptional repressor Rex controls central carbon and energy metabolism by sensing the intra cellular balance between the reduced and oxidized forms of nicotinamide adenine dinucleotide; the NADH/NAD+ ratio. Here, we report high-resolution crystal structures and characterization of a Rex ortholog (Gbs1167) in the opportunistic pathogen, Streptococcus agalactiae, also known as group B streptococcus (GBS). We present structures of Rex bound to NAD+ and to a DNA operator which are the first structures of a Rex-family member from a pathogenic bacterium. The structures reveal the molecular basis of DNA binding and the conformation alterations between the free NAD+ complex and DNA-bound form of Rex. Transcriptomic analysis revealed that GBS Rex controls not only central metabolism, but also expression of the monocistronic rex gene as well as virulence gene expression. Rex enhances GBS virulence after disseminated infection in mice. Mechanistically, NAD+ stabilizes Rex as a repressor in the absence of NADH. However, GBS Rex is unique compared to Rex regulators previously characterized because of its sensing mechanism: we show that it primarily responds to NAD+ levels (or growth rate) rather than to the NADH/NAD+ ratio. These results indicate that Rex plays a key role in GBS pathogenicity by modulating virulence factor gene expression and carbon metabolism to harvest nutrients from the host.
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19
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Silvestre I, Nunes A, Borges V, Isidro J, Silva C, Vieira L, Gomes JP, Borrego MJ. Genomic insights on DNase production in Streptococcus agalactiae ST17 and ST19 strains. INFECTION GENETICS AND EVOLUTION 2021; 93:104969. [PMID: 34147652 DOI: 10.1016/j.meegid.2021.104969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 10/21/2022]
Abstract
Streptococcus agalactiae evasion from the human defense mechanisms has been linked to the production of DNases. These were proposed to contribute to the hypervirulence of S. agalactiae ST17/capsular-type III strains, mostly associated with neonatal meningitis. We performed a comparative genomic analysis between ST17 and ST19 human strains with different cell tropism and distinct DNase production phenotypes. All S. agalactiae ST17 strains, with the exception of 2211-04, were found to display DNase activity, while the opposite scenario was observed for ST19, where 1203-05 was the only DNase(+) strain. The analysis of the genetic variability of the seven genes putatively encoding secreted DNases in S. agalactiae revealed an exclusive amino acid change in the predicted signal peptide of GBS0661 (NucA) of the ST17 DNase(-), and an exclusive amino acid change alteration in GBS0609 of the ST19 DNase(+) strain. Further core-genome analysis identified some specificities (SNVs or indels) differentiating the DNase(-) ST17 2211-04 and the DNase(+) ST19 1203-05 from the remaining strains of each ST. The pan-genomic analysis evidenced an intact phage without homology in S. agalactiae and a transposon homologous to TnGBS2.3 in ST17 DNase(-) 2211-04; the transposon was also found in one ST17 DNase(+) strain, yet with a different site of insertion. A group of nine accessory genes were identified among all ST17 DNase(+) strains, including the Eco47II family restriction endonuclease and the C-5 cytosine-specific DNA methylase. None of these loci was found in any DNase(-) strain, which may suggest that these proteins might contribute to the lack of DNase activity. In summary, we provide novel insights on the genetic diversity between DNase(+) and DNase(-) strains, and identified genetic traits, namely specific mutations affecting predicted DNases (NucA and GBS0609) and differences in the accessory genome, that need further investigation as they may justify distinct DNase-related virulence phenotypes in S. agalactiae.
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Affiliation(s)
- Inês Silvestre
- Department of Life Sciences, UCIBIO, Nova School of Science and Technology, 2829-516 Caparica, Portugal; National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; CBIOS - Research Center for Biosciences & Health Technologies, Lusófona University of Humanities and Technologies, Campo Grande 376, 1749-024 Lisbon, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Joana Isidro
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Catarina Silva
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Maria José Borrego
- National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
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20
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Alves-Barroco C, Paquete-Ferreira J, Santos-Silva T, Fernandes AR. Singularities of Pyogenic Streptococcal Biofilms - From Formation to Health Implication. Front Microbiol 2021; 11:584947. [PMID: 33424785 PMCID: PMC7785724 DOI: 10.3389/fmicb.2020.584947] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 11/20/2020] [Indexed: 01/09/2023] Open
Abstract
Biofilms are generally defined as communities of cells involved in a self-produced extracellular matrix adhered to a surface. In biofilms, the bacteria are less sensitive to host defense mechanisms and antimicrobial agents, due to multiple strategies, that involve modulation of gene expression, controlled metabolic rate, intercellular communication, composition, and 3D architecture of the extracellular matrix. These factors play a key role in streptococci pathogenesis, contributing to therapy failure and promoting persistent infections. The species of the pyogenic group together with Streptococcus pneumoniae are the major pathogens belonging the genus Streptococcus, and its biofilm growth has been investigated, but insights in the genetic origin of biofilm formation are limited. This review summarizes pyogenic streptococci biofilms with details on constitution, formation, and virulence factors associated with formation.
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Affiliation(s)
- Cinthia Alves-Barroco
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - João Paquete-Ferreira
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - Teresa Santos-Silva
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
| | - Alexandra R Fernandes
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal
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21
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Bouchery T, Moyat M, Sotillo J, Silverstein S, Volpe B, Coakley G, Tsourouktsoglou TD, Becker L, Shah K, Kulagin M, Guiet R, Camberis M, Schmidt A, Seitz A, Giacomin P, Le Gros G, Papayannopoulos V, Loukas A, Harris NL. Hookworms Evade Host Immunity by Secreting a Deoxyribonuclease to Degrade Neutrophil Extracellular Traps. Cell Host Microbe 2020; 27:277-289.e6. [PMID: 32053791 DOI: 10.1016/j.chom.2020.01.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/15/2019] [Accepted: 01/17/2020] [Indexed: 12/11/2022]
Abstract
Hookworms cause a major neglected tropical disease, occurring after larvae penetrate the host skin. Neutrophils are phagocytes that kill large pathogens by releasing neutrophil extracellular traps (NETs), but whether they target hookworms during skin infection is unknown. Using a murine hookworm, Nippostrongylus brasiliensis, we observed neutrophils being rapidly recruited and deploying NETs around skin-penetrating larvae. Neutrophils depletion or NET inhibition altered larvae behavior and enhanced the number of adult worms following murine infection. Nevertheless, larvae were able to mitigate the effect of NETs by secreting a deoxyribonuclease (Nb-DNase II) to degrade the DNA backbone. Critically, neutrophils were able to kill larvae in vitro, which was enhanced by neutralizing Nb-DNase II. Homologs of Nb-DNase II are present in other nematodes, including the human hookworm, Necator americanus, which also evaded NETs in vitro. These findings highlight the importance of neutrophils in hookworm infection and a potential conserved mechanism of immune evasion.
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Affiliation(s)
- Tiffany Bouchery
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia; Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Mati Moyat
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia; Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Javier Sotillo
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia; Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid 28222, Spain
| | - Solomon Silverstein
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia
| | - Beatrice Volpe
- Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Gillian Coakley
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia
| | | | - Luke Becker
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia
| | - Kathleen Shah
- Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Manuel Kulagin
- Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Romain Guiet
- Bioimaging and Optics Core Facility, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Mali Camberis
- Malaghan Institute of Medical Research, Wellington 6242, New Zealand
| | - Alfonso Schmidt
- Hugh Green Cytometry Centre, Malaghan Institute of Medical Research, Wellington 6242, New Zealand
| | - Arne Seitz
- Bioimaging and Optics Core Facility, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Paul Giacomin
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia
| | - Graham Le Gros
- Malaghan Institute of Medical Research, Wellington 6242, New Zealand
| | | | - Alex Loukas
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia
| | - Nicola L Harris
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia.
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22
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Carreras-Abad C, Ramkhelawon L, Heath PT, Le Doare K. A Vaccine Against Group B Streptococcus: Recent Advances. Infect Drug Resist 2020; 13:1263-1272. [PMID: 32425562 PMCID: PMC7196769 DOI: 10.2147/idr.s203454] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/10/2020] [Indexed: 01/12/2023] Open
Abstract
Group B streptococcus (GBS) causes a high burden of neonatal and infant disease globally. Implementing a vaccine for pregnant women is a promising strategy to prevent neonatal and infant GBS disease and has been identified as a priority by the World Health Organisation (WHO). GBS serotype-specific polysaccharide – protein conjugate vaccines are at advanced stages of development, but a large number of participants would be required to undertake Phase III clinical efficacy trials. Efforts are therefore currently focused on establishing serocorrelates of protection in natural immunity studies as an alternative pathway for licensure of a GBS vaccine, followed by Phase IV studies to evaluate safety and effectiveness. Protein vaccines are in earlier stages of development but are highly promising as they might confer protection irrespective of serotype. Further epidemiological, immunological and health economic studies are required to enable the vaccine to reach its target population as soon as possible.
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Affiliation(s)
- Clara Carreras-Abad
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK.,Department of Paediatrics, Obstetrics and Gynecology and Preventive Medicine and Public Health, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laxmee Ramkhelawon
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Paul T Heath
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Kirsty Le Doare
- Paediatric Infectious Diseases Research Group and Vaccine Institute, Institute for Infection and Immunity, St George's, University of London, London, UK.,Pathogen Immunity Group, Public Health England, Porton Down,UK.,Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine, Uganda Research Unit, Entebbe, Uganda
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23
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Neumann A, Brogden G, von Köckritz-Blickwede M. Extracellular Traps: An Ancient Weapon of Multiple Kingdoms. BIOLOGY 2020; 9:biology9020034. [PMID: 32085405 PMCID: PMC7168307 DOI: 10.3390/biology9020034] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/31/2022]
Abstract
The discovery, in 2004, of extracellular traps released by neutrophils has extended our understanding of the mode of action of various innate immune cells. This fascinating discovery demonstrated the extracellular trapping and killing of various pathogens by neutrophils. During the last decade, evidence has accumulated showing that extracellular traps play a crucial role in the defence mechanisms of various cell types present in vertebrates, invertebrates, and plants. The aim of this review is to summarise the relevant literature on the evolutionary history of extracellular traps used as a weapon in various kingdoms of life.
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Affiliation(s)
- Ariane Neumann
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, Baravägen 27, 22184 Lund, Sweden;
| | - Graham Brogden
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Buenteweg 17, 30559 Hannover, Germany;
| | - Maren von Köckritz-Blickwede
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Buenteweg 17, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Bünteweg 17, 30559 Hannover, Germany
- Correspondence: ; Tel.: +49-511-953-8787
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24
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Soh KY, Loh JMS, Proft T. Cell wall-anchored 5'-nucleotidases in Gram-positive cocci. Mol Microbiol 2020; 113:691-698. [PMID: 31872460 DOI: 10.1111/mmi.14442] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 11/29/2022]
Abstract
5'-nucleotidases (5'-NTs) are enzymes that catalyze the hydrolysis of nucleoside monophosphates to produce nucleosides and phosphate. Since the identification of adenosine synthase A (AdsA) in Staphylococcus aureus in 2009, several other 5'-NTs have been discovered in Gram-positive cocci, mainly in streptococci. Despite some differences in substrate specificity, pH range and metal ion requirements, all characterized 5'-NTs use AMP and ADP, and in some cases ATP, to produce the immunosuppressive adenosine, which dampens pro-inflammatory immune responses. Several 5'-NTs are also able to use dAMP as substrate to generate deoxy-adenosine which is cytotoxic for macrophages. A synergy between 5'-NTs and exonucleases which are commonly expressed in Gram-positive cocci has been described, where the nucleases provide dAMP as a cleavage product from DNA. Some of these nucleases produce dAMP by degrading the DNA backbone of neutrophil extracellular traps (NETs) resulting in a "double hit" strategy of immune evasion. This Micro Review provides an overview of the biochemical properties of Gram-positive cell wall-anchored 5'-NTs and their role as virulence factors. A potential use of 5'-NTs for vaccine development is also briefly discussed.
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Affiliation(s)
- Kar Yan Soh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand
| | - Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Biomolecular Discoveries, The University of Auckland, Auckland, New Zealand
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25
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Sharma P, Garg N, Sharma A, Capalash N, Singh R. Nucleases of bacterial pathogens as virulence factors, therapeutic targets and diagnostic markers. Int J Med Microbiol 2019; 309:151354. [PMID: 31495663 DOI: 10.1016/j.ijmm.2019.151354] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/12/2019] [Accepted: 08/29/2019] [Indexed: 12/25/2022] Open
Abstract
New frontiers of therapy are being explored against the upcoming bacterial diseases rendered untreatable due to multiple, extreme and pan- antibiotic resistance. Nucleases are ubiquitous in bacterial pathogens performing various functions like acquiring nucleotide nutrients, allowing or preventing uptake of foreign DNA, controlling biofilm formation/dispersal/architecture, invading host by tissue damage, evading immune defence by degrading DNA matrix of neutrophil extracellular traps (NETs) and immunomodulating the host immune response. Secretory nucleases also provide means of survival to other bacteria like iron-reducing Shewanella and such functions help them adapt and survive proficiently. Other than their pro-pathogen roles in survival, nucleases can be used directly as therapeutics. One of the powerful armours of pathogens is the formation of biofilms, thus helping them resist and persist in the harshest of environments. As eDNA forms the structural and binding component of biofilm, nucleases can be used against the adhering component, thus increasing the permeability of antimicrobial agents. Nucleases have recently become a model system of intense study for their biological functions and medical applications in diagnosis, immunoprophylaxis and therapy. Rational implications of these enzymes can impact human medicine positively in future by opening new ways for therapeutics which have otherwise reached saturation due to multi drug resistance.
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Affiliation(s)
- Prince Sharma
- Department of Microbiology, Panjab University, Chandigarh, India.
| | - Nisha Garg
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Anshul Sharma
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Ravinder Singh
- Department of Microbiology, Panjab University, Chandigarh, India
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26
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27
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28
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Florindo C, Barroco CA, Silvestre I, Damião V, Gomes JP, Spellerberg B, Santos-Sanches I, Borrego MJ. Capsular Type, Sequence Type and Microbial Resistance Factors Impact on DNase Activity of Streptococcus agalactiae Strains from Human and Bovine Origin. Eur J Microbiol Immunol (Bp) 2018; 8:149-154. [PMID: 30719332 PMCID: PMC6348702 DOI: 10.1556/1886.2018.00026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/13/2018] [Indexed: 12/20/2022] Open
Abstract
Extracellular deoxyribonucleases (DNases) contribute to the spread of pathogenic bacteria through the evasion from host innate immunity. Our main objective was to evaluate the production of extracellular DNases by human and bovine Streptococcus agalactiae clinical strains and perform a correlation of genetic lineages and DNase activity with capsular type, genetic determinants, clinical origin (colonization and infection), and host (human or bovine). DNase activity was evaluated by qualitative and quantitative assays for a collection of 406 human (n = 285) and bovine (n = 121) strains. All (121/121) bovine were isolated from mastitis and revealed to be DNase (+), indicating a putative pathogenic role in this clinical scenario. From the human S. agalactiae strains, 86% (245/285) showed DNase activity, among which all strains belonging to capsular types, namely, Ia, Ib, III-2, and IV. All CC17 strains (n = 58) and 56/96 (58.3%) of the CC19 displayed DNase activity. DNase (-) strains belonged to the CC19 group. However, the subcharacterization of CC19 S. agalactiae strains through multiple-locus variable number tandem repeat analysis (MLVA), antibiotic resistance, mobile elements, and surface proteins did not provide any distinction among DNase producers and non-producers. The production of DNases by all human CC17 strains, about two-fifths of human CC19, and all bovine strains, suggest an important contribution of DNases to hypervirulence.
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Affiliation(s)
- Carlos Florindo
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | - Cinthia Alves Barroco
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
| | - Inês Silvestre
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | - Vera Damião
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | - João Paulo Gomes
- Department of Infectious Diseases, National Institute of Health, Lisbon
| | | | - Ilda Santos-Sanches
- Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Departamento de Ciências da Vida, UCIBIO
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Type 2 NADH Dehydrogenase Is the Only Point of Entry for Electrons into the Streptococcus agalactiae Respiratory Chain and Is a Potential Drug Target. mBio 2018; 9:mBio.01034-18. [PMID: 29970468 PMCID: PMC6030563 DOI: 10.1128/mbio.01034-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The opportunistic pathogen Streptococcus agalactiae is the major cause of meningitis and sepsis in a newborn’s first week, as well as a considerable cause of pneumonia, urinary tract infections, and sepsis in immunocompromised adults. This pathogen respires aerobically if heme and quinone are available in the environment, and a functional respiratory chain is required for full virulence. Remarkably, it is shown here that the entire respiratory chain of S. agalactiae consists of only two enzymes, a type 2 NADH dehydrogenase (NDH-2) and a cytochrome bd oxygen reductase. There are no respiratory dehydrogenases other than NDH-2 to feed electrons into the respiratory chain, and there is only one respiratory oxygen reductase to reduce oxygen to water. Although S. agalactiae grows well in vitro by fermentative metabolism, it is shown here that the absence of NDH-2 results in attenuated virulence, as observed by reduced colonization in heart and kidney in a mouse model of systemic infection. The lack of NDH-2 in mammalian mitochondria and its important role for virulence suggest this enzyme may be a potential drug target. For this reason, in this study, S. agalactiae NDH-2 was purified and biochemically characterized, and the isolated enzyme was used to screen for inhibitors from libraries of FDA-approved drugs. Zafirlukast was identified to successfully inhibit both NDH-2 activity and aerobic respiration in intact cells. This compound may be useful as a laboratory tool to inhibit respiration in S. agalactiae and, since it has few side effects, it might be considered a lead compound for therapeutics development. S. agalactiae is part of the human intestinal microbiota and is present in the vagina of ~30% of healthy women. Although a commensal, it is also the leading cause of septicemia and meningitis in neonates and immunocompromised adults. This organism can aerobically respire, but only using external sources of heme and quinone, required to have a functional electron transport chain. Although bacteria usually have a branched respiratory chain with multiple dehydrogenases and terminal oxygen reductases, here we establish that S. agalactiae utilizes only one type 2 NADH dehydrogenase (NDH-2) and one cytochrome bd oxygen reductase to perform respiration. NADH-dependent respiration plays a critical role in the pathogen in maintaining NADH/NAD+ redox balance in the cell, optimizing ATP production, and tolerating oxygen. In summary, we demonstrate the essential role of NDH-2 in respiration and its contribution to S. agalactiae virulence and propose it as a potential drug target.
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30
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Jhelum H, Sori H, Sehgal D. A novel extracellular vesicle-associated endodeoxyribonuclease helps Streptococcus pneumoniae evade neutrophil extracellular traps and is required for full virulence. Sci Rep 2018; 8:7985. [PMID: 29789571 PMCID: PMC5964101 DOI: 10.1038/s41598-018-25865-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/26/2018] [Indexed: 12/22/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a major bacterial pathogen that causes pneumonia and septicemia in humans. Pneumococci are cleared from the host primarily by antibody dependent opsonophagocytosis by phagocytes like neutrophils. Neutrophils release neutrophil extracellular traps (NETs) on contacting pneumococci. NETs immobilize pneumococci and restrict its dissemination in the host. One of the strategies utilized by pneumococci to evade the host immune response involves use of DNase(s) to degrade NETs. We screened the secretome of autolysin deficient S. pneumoniae to identify novel DNase(s). Zymogram analysis revealed 3 bands indicative of DNase activity. Mass spectrometric analysis led to the identification of TatD as a potential extracellular DNase. Recombinant TatD showed nucleotide sequence-independent endodeoxyribonuclease activity. TatD was associated with extracellular vesicles. Pneumococcal secretome degraded NETs from human neutrophils. Extracellular vesicle fraction from tatD deficient strain showed little NET degrading activity. Recombinant TatD efficiently degraded NETs. tatD deficient pneumococci showed lower bacterial load in lungs, blood and spleen in a murine sepsis model compared to wildtype strain, and showed less severe lung pathology and compromised virulence. This study provides insights into the role of a novel extracellular DNase in evasion of the innate immune system.
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Affiliation(s)
- Hina Jhelum
- Molecular Immunology Laboratory, National Institute of Immunology, New Delhi, India
| | - Hema Sori
- Molecular Immunology Laboratory, National Institute of Immunology, New Delhi, India
| | - Devinder Sehgal
- Molecular Immunology Laboratory, National Institute of Immunology, New Delhi, India.
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31
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Mitiku F, Hartley CA, Sansom FM, Coombe JE, Mansell PD, Beggs DS, Browning GF. The major membrane nuclease MnuA degrades neutrophil extracellular traps induced by Mycoplasma bovis. Vet Microbiol 2018; 218:13-19. [DOI: 10.1016/j.vetmic.2018.03.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 03/04/2018] [Accepted: 03/05/2018] [Indexed: 12/19/2022]
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32
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Pietrocola G, Arciola CR, Rindi S, Montanaro L, Speziale P. Streptococcus agalactiae Non-Pilus, Cell Wall-Anchored Proteins: Involvement in Colonization and Pathogenesis and Potential as Vaccine Candidates. Front Immunol 2018; 9:602. [PMID: 29686667 PMCID: PMC5900788 DOI: 10.3389/fimmu.2018.00602] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/09/2018] [Indexed: 11/13/2022] Open
Abstract
Group B Streptococcus (GBS) remains an important etiological agent of several infectious diseases including neonatal septicemia, pneumonia, meningitis, and orthopedic device infections. This pathogenicity is due to a variety of virulence factors expressed by Streptococcus agalactiae. Single virulence factors are not sufficient to provoke a streptococcal infection, which is instead promoted by the coordinated activity of several pathogenicity factors. Such determinants, mostly cell wall-associated and secreted proteins, include adhesins that mediate binding of the pathogen to host extracellular matrix/plasma ligands and cell surfaces, proteins that cooperate in the invasion of and survival within host cells and factors that neutralize phagocytosis and/or modulate the immune response. The genome-based approaches and bioinformatics tools and the extensive use of biophysical and biochemical methods and animal model studies have provided a great wealth of information on the molecular structure and function of these virulence factors. In fact, a number of new GBS surface-exposed or secreted proteins have been identified (GBS immunogenic bacterial adhesion protein, leucine-rich repeat of GBS, serine-rich repeat proteins), the three-dimensional structures of known streptococcal proteins (αC protein, C5a peptidase) have been solved and an understanding of the pathogenetic role of "old" and new determinants has been better defined in recent years. Herein, we provide an update of our current understanding of the major surface cell wall-anchored proteins from GBS, with emphasis on their biochemical and structural properties and the pathogenetic roles they may have in the onset and progression of host infection. We also focus on the antigenic profile of these compounds and discuss them as targets for therapeutic intervention.
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Affiliation(s)
- Giampiero Pietrocola
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Bologna, Italy.,Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Simonetta Rindi
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Lucio Montanaro
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Bologna, Italy.,Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Pietro Speziale
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Department of Industrial and Information Engineering, University of Pavia, Pavia, Italy
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33
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Li P, Xu J, Rao HM, Li X, Zhang YK, Jiang F, Wu WX. Mechanism of Apoptosis Induction by Mycoplasmal Nuclease MGA_0676 in Chicken Embryo Fibroblasts. Front Cell Infect Microbiol 2018; 8:105. [PMID: 29670864 PMCID: PMC5893762 DOI: 10.3389/fcimb.2018.00105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 03/19/2018] [Indexed: 12/22/2022] Open
Abstract
MGA_0676 has been characterized as a Mycoplasma gallisepticum nuclease that can induce apoptosis of chicken cells. However, the mechanism by which MGA_0676 induces apoptosis has remained unclear. In this study, we evaluated MGA_0676-induced apoptosis and internalization in immortalized chicken embryo fibroblasts (DF-1) and cancer cell lines. The internalization of MGA_0676 was proven through caveolin-mediated endocytosis by blocking the endocytosis with specific inhibitors or with siRNA. We identified the Thif domain of NEDD8-activating enzyme E1 regulatory subunit (NAE) in DF-1 as the target region interacting with the SNC domain of MGA_0676. The interaction between the Thif and SNC domains was observed co-located in the perinuclear and nuclear of DF-1. We found that the interaction between NAE and MGA_0676 increased the ability of apoptosis and accelerated the process of cullin neddylation in DF-1 cells, in turn activating NF-κB. This resulted in the observed aggregation of NF-κB in the nuclei of DF-1 cells. Moreover, the apoptosis induced by MGA_0676 decreased significantly when NF-κB was inhibited by siRNA or BAY 11-7082 or when NAE was silenced by siRNA. Overall, our results demonstrate that MGA_0676 is internalized through caveolin-mediated endocytosis, interacts with SNC-dependent Thif to accelerate the process of cullin neddylation and activates NF-κB in DF-1 cells, ultimately playing a key role in apoptosis in chicken cells. Our results indicate MGA_0676 constitutes a critical etiological virulence factor of the respiratory disease caused by M. gallisepticum. This study also opens a venue to investigate MGA_0676 as a potential candidate as pro-apoptotic drug in cancer studies.
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Affiliation(s)
- Peng Li
- Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jian Xu
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
| | - Hong-Mei Rao
- Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xia Li
- Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yun-Ke Zhang
- Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Fei Jiang
- Veterinary Diagnostic Laboratory, China Animal Disease Control Center, Beijing, China
| | - Wen-Xue Wu
- Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, China Agricultural University, Beijing, China
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34
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Neutrophils and neutrophil extracellular traps in the liver and gastrointestinal system. Nat Rev Gastroenterol Hepatol 2018; 15:206-221. [PMID: 29382950 DOI: 10.1038/nrgastro.2017.183] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neutrophil extracellular traps (NETs) have an important role during infection by helping neutrophils to capture and kill pathogens. However, evidence is accumulating that uncontrolled or excessive production of NETs is related to the exacerbation of inflammation and the development of autoimmunity, cancer metastasis and inappropriate thrombosis. In this Review, we focus on the role of NETs in the liver and gastrointestinal system, outlining their protective and pathological effects. The latest mechanistic insights in NET formation, interactions between microorganisms and NETs and the relationship between neutrophil subtypes and their functions are also discussed. Additionally, we describe the potential importance of NET-related molecules, including cell-free DNA and hypercitrullinated histones, as biomarkers and targets for therapeutic intervention in gastrointestinal diseases.
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35
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Remmington A, Turner CE. The DNases of pathogenic Lancefield streptococci. MICROBIOLOGY (READING, ENGLAND) 2018; 164:242-250. [PMID: 29458565 DOI: 10.1099/mic.0.000612] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
DNases are abundant among the pathogenic streptococci, with most species harbouring genes for at least one. Despite their prevalence, however, the role for these extracellular enzymes is still relatively unclear. The DNases of the Lancefield group A Streptococcus, S. pyogenes are the best characterized, with a total of eight DNase genes identified so far. Six are known to be associated with integrated prophages. Two are chromosomally encoded, and one of these is cell-wall anchored. Homologues of both prophage-associated and chromosomally encoded S. pyogenes DNases have been identified in other streptococcal species, as well as other unique DNases. A major role identified for streptococcal DNases appears to be in the destruction of extracellular traps produced by immune cells, such as neutrophils, to ensnare bacteria and kill them. These traps are composed primarily of DNA which can be degraded by the secreted and cell-wall-anchored streptococcal DNases. DNases can also reduce TLR-9 signalling to dampen the immune response and produce cytotoxic deoxyadenosine to limit phagocytosis. Upper respiratory tract infection models of S. pyogenes have identified a role for DNases in potentiating infection and transmission, possibly by limiting the immune response or through some other unknown mechanism. Streptococcal DNases may also be involved in interacting with other microbial communities through communication, bacterial killing and disruption of competitive biofilms, or control of their own biofilm production. The contribution of DNases to pathogenesis may therefore be wide ranging and extend beyond direct interference with the host immune response.
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Affiliation(s)
- Alex Remmington
- Department of Molecular Biology and Biotechnology, The Florey Institute, University of Sheffield, Sheffield, UK
| | - Claire E Turner
- Department of Molecular Biology and Biotechnology, The Florey Institute, University of Sheffield, Sheffield, UK
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36
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Jablonska J, Matelska D, Steczkiewicz K, Ginalski K. Systematic classification of the His-Me finger superfamily. Nucleic Acids Res 2017; 45:11479-11494. [PMID: 29040665 PMCID: PMC5714182 DOI: 10.1093/nar/gkx924] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/29/2017] [Indexed: 02/06/2023] Open
Abstract
The His-Me finger endonucleases, also known as HNH or ββα-metal endonucleases, form a large and diverse protein superfamily. The His-Me finger domain can be found in proteins that play an essential role in cells, including genome maintenance, intron homing, host defense and target offense. Its overall structural compactness and non-specificity make it a perfectly-tailored pathogenic module that participates on both sides of inter- and intra-organismal competition. An extremely low sequence similarity across the superfamily makes it difficult to identify and classify new His-Me fingers. Using state-of-the-art distant homology detection methods, we provide an updated and systematic classification of His-Me finger proteins. In this work, we identified over 100 000 proteins and clustered them into 38 groups, of which three groups are new and cannot be found in any existing public domain database of protein families. Based on an analysis of sequences, structures, domain architectures, and genomic contexts, we provide a careful functional annotation of the poorly characterized members of this superfamily. Our results may inspire further experimental investigations that should address the predicted activity and clarify the potential substrates, to provide more detailed insights into the fundamental biological roles of these proteins.
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Affiliation(s)
- Jagoda Jablonska
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Dorota Matelska
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Kamil Steczkiewicz
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Krzysztof Ginalski
- Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
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Regli IB, Passelli K, Hurrell BP, Tacchini-Cottier F. Survival Mechanisms Used by Some Leishmania Species to Escape Neutrophil Killing. Front Immunol 2017; 8:1558. [PMID: 29250059 PMCID: PMC5715327 DOI: 10.3389/fimmu.2017.01558] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 10/31/2017] [Indexed: 12/27/2022] Open
Abstract
Neutrophils are the most abundant leukocytes in human blood. Upon microbial infection, they are massively and rapidly recruited from the circulation to sites of infection where they efficiently kill pathogens. To this end, neutrophils possess a variety of weapons that can be mobilized and become effective within hours following infection. However, several microbes including some Leishmania spp. have evolved a variety of mechanisms to escape neutrophil killing using these cells as a basis to better invade the host. In addition, neutrophils are also present in unhealing cutaneous lesions where their role remains to be defined. Here, we will review recent progress in the field and discuss the different strategies applied by some Leishmania parasites to escape from being killed by neutrophils and as recently described for Leishmania mexicana, even replicate within these cells. Subversion of neutrophil killing functions by Leishmania is a strategy that allows parasite spreading in the host with a consequent deleterious impact, transforming the primary protective role of neutrophils into a deleterious one.
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Affiliation(s)
- Ivo B Regli
- Department of Biochemistry, WHO Immunology Research and Training Collaborative Center, University of Lausanne, Lausanne, Switzerland
| | - Katiuska Passelli
- Department of Biochemistry, WHO Immunology Research and Training Collaborative Center, University of Lausanne, Lausanne, Switzerland
| | - Benjamin P Hurrell
- Department of Biochemistry, WHO Immunology Research and Training Collaborative Center, University of Lausanne, Lausanne, Switzerland
| | - Fabienne Tacchini-Cottier
- Department of Biochemistry, WHO Immunology Research and Training Collaborative Center, University of Lausanne, Lausanne, Switzerland
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Streptococcus pyogenes nuclease A (SpnA) mediated virulence does not exclusively depend on nuclease activity. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2017; 53:42-48. [PMID: 29158081 DOI: 10.1016/j.jmii.2017.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/21/2017] [Accepted: 09/18/2017] [Indexed: 01/25/2023]
Abstract
BACKGROUND Streptococcus pyogenes, or Group A Streptococcus (GAS), is a human pathogen that causes a wide range of diseases, including pharyngitis, necrotizing fasciitis and toxic shock syndrome. The bacterium produces a large arsenal of virulence factors, including the cell wall-anchored Streptococcus pyogenes nuclease A (SpnA), which facilitates immune evasion by degrading the DNA backbone of neutrophil extracellular traps. SpnA consists of a C-terminal endo/exonuclease domain and a N-terminal domain of unknown function. METHODS Recombinant SpnA mutants were generated by alanine conversion of selected residues that were predicted to play a role in the enzymatic activity and tested for their ability to degrade DNA. A GAS spnA deletion mutant was complemented with a plasmid-borne catalytic site mutant and analyzed for virulence in a Galleria mellonella (wax moth) infection model. RESULTS Several predicted residues were experimentally confirmed to play a role in SpnA enzymatic activity. These include Glu592, Arg696, His716, Asp767, Asn769, Asp810 and Asp842. Complementation of a GAS spnA deletion mutant with a spnA H716A mutant gene partially restored virulence in wax moth larvae, whereas complementation with the spnA wt gene completely restored activity. Furthermore, complementation with a secreted form of SpnA showed reduced virulence. CONCLUSION Our results show that abolishing the enzymatic activity of SpnA only partially reduces virulence suggesting that SpnA has an additional virulence function, which might be located on the N-terminal domain. Furthermore, cell wall-anchoring of SpnA results in higher virulence compared to secreted SpnA, probably due to a higher local density of the enzyme.
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Intrinsic Maturational Neonatal Immune Deficiencies and Susceptibility to Group B Streptococcus Infection. Clin Microbiol Rev 2017; 30:973-989. [PMID: 28814408 DOI: 10.1128/cmr.00019-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although a normal member of the gastrointestinal and vaginal microbiota, group B Streptococcus (GBS) can also occasionally be the cause of highly invasive neonatal disease and is an emerging pathogen in both elderly and immunocompromised adults. Neonatal GBS infections are typically transmitted from mother to baby either in utero or during passage through the birth canal and can lead to pneumonia, sepsis, and meningitis within the first few months of life. Compared to the adult immune system, the neonatal immune system has a number of deficiencies, making neonates more susceptible to infection. Recognition of GBS by the host immune system triggers an inflammatory response to clear the pathogen. However, GBS has developed several mechanisms to evade the host immune response. A comprehensive understanding of this interplay between GBS and the host immune system will aid in the development of new preventative measures and therapeutics.
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40
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McFarland AP, Woodward JJ. Flying Under the Radar: Immune Evasion by Group B Streptococcus. Cell Host Microbe 2017; 20:4-6. [PMID: 27414494 DOI: 10.1016/j.chom.2016.06.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Type I IFN production is an important host defense mechanism against Gram-positive Streptococci. In this issue of Cell Host & Microbe, Andrade et al. (2016) report that Group B Streptococcus limits type I IFN by expressing a surface phosphodiesterase that degrades extracellular bacterial cyclic dinucleotides, thereby promoting virulence.
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Affiliation(s)
- Adelle P McFarland
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
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Rebordão MR, Alexandre-Pires G, Carreira M, Adriano L, Carneiro C, Nunes T, Mateus L, Ferreira-Dias G. Bacteria causing pyometra in bitch and queen induce neutrophil extracellular traps. Vet Immunol Immunopathol 2017; 192:8-12. [PMID: 29042016 DOI: 10.1016/j.vetimm.2017.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 08/22/2017] [Accepted: 09/02/2017] [Indexed: 12/18/2022]
Abstract
Neutrophils are capable of releasing their DNA in response to infectious agents to form neutrophil extracellular traps (NETs) to destroy pathogens. Even though pyometra in queens and bitches is a common disease, its pathogenesis is not fully understood. The aim of this study was to assess the presence of NETs in the endometrium of queens and bitches suffering from pyometra. Pyometra and normal uteri were obtained after ovariohysterectomy from adult queens and bitches in diestrus. Uterine contents were evaluated for bacterial isolation and identification and for NETs presence. Escherichia coli were isolated in 5/5 queens and 4/5 bitches, and Streptococcus spp in one bitch. Sterile glass coverslips were placed on the endometrium surface to obtain material for NETs that were evaluated by immunocytochemistry (histone, neutrophil elastase or myeloperoxidase), fluorescence microscopy or scanning electron microscopy. NETs in endometrium content were positively stained by DNA histone DAPI, myeloperoxidase and by neutrophil elastase. NETs were spread in all observed queen and bitch endometria of pyometra cases. Ultrastructure images of NETs depicted clusters of globular material with fine filaments deposited on or around thick filaments and trapped bacteria. To the best of our knowledge these are the first findings confirming NETs endometrial presence in queen and bitch pyometra. Nevertheless, the precise role of NETs in pyometra in the bitch and queen, either to contribute to the defeat of infection or to its persistence remains to be unraveled.
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Affiliation(s)
- M R Rebordão
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal; Clínica Veterinária das Nogueiras, R. Estádio 6, 3030-318 Coimbra, Portugal; Coimbra College of Agriculture, Bencanta, 3045-601 Coimbra, Portugal
| | - G Alexandre-Pires
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal
| | - M Carreira
- Clínica Veterinária das Nogueiras, R. Estádio 6, 3030-318 Coimbra, Portugal
| | - L Adriano
- Clínica Veterinária das Nogueiras, R. Estádio 6, 3030-318 Coimbra, Portugal
| | - C Carneiro
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal
| | - T Nunes
- Faculty of Sciences, Microscopy Center, University of Lisbon, Campo Grande C2, 1749-016 Lisbon, Portugal
| | - L Mateus
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal
| | - G Ferreira-Dias
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal.
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Gomez-Lopez N, Romero R, Xu Y, Miller D, Unkel R, Shaman M, Jacques SM, Panaitescu B, Garcia-Flores V, Hassan SS. Neutrophil Extracellular Traps in the Amniotic Cavity of Women with Intra-Amniotic Infection: A New Mechanism of Host Defense. Reprod Sci 2017; 24:1139-1153. [PMID: 27884950 PMCID: PMC6343453 DOI: 10.1177/1933719116678690] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Neutrophil extracellular traps (NETs) control microbial infections through their antimicrobial activities attributed to DNA, histones, granules, and cytoplasmic proteins (eg, elastase). Intra-amniotic infection is characterized by the influx of neutrophils into the amniotic cavity; therefore, the aim of this study was to determine whether amniotic fluid neutrophils form NETs in this inflammatory process. METHODS Amniotic fluid samples from women with intra-amniotic infection (n = 15) were stained for bacteria detection using fluorescent dyes. Amniotic fluid neutrophils were purified by filtration. As controls, neutrophils from maternal blood samples (n = 3) were isolated by density gradients. Isolated neutrophils were plated onto glass cover slips for culture with and without 100 nM of phorbol-12-myristate-13-acetate (PMA). NET formation was assessed by 4',6-diamidino-2-phenylindole (DAPI) staining and scanning electron microscopy. Different stages of NET formation were visualized using antibodies against elastase and histone H3, in combination with DAPI staining, by confocal microscopy. Finally, maternal or neonatal neutrophils were added to amniotic fluid samples from women without intra-amniotic infection (n = 4), and NET formation was evaluated by DAPI staining. RESULTS (1) NETs were present in the amniotic fluid of women with intra-amniotic infection; (2) all of the amniotic fluid samples had detectable live and dead bacteria associated with the presence of NETs; (3) in contrast to neutrophils from the maternal circulation, amniotic fluid neutrophils did not require PMA stimulation to form NETs; (4) different stages of NET formation were observed by co-localizing elastase, histone H3, and DNA in amniotic fluid neutrophils; and (5) neither maternal nor neonatal neutrophils form NETs in the amniotic fluid of women without intra-amniotic infection. CONCLUSION NETs are detectable in the amniotic fluid of women with intra-amniotic infection.
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Affiliation(s)
- Nardhy Gomez-Lopez
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
- Department of Immunology and Microbiology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Roberto Romero
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor,
MI, USA
- Department of Epidemiology and Biostatistics, Michigan State University,
East Lansing, MI, USA
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit,
MI, USA
| | - Yi Xu
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Derek Miller
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
- Department of Immunology and Microbiology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Ronald Unkel
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Majid Shaman
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Suzanne M. Jacques
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Pathology, Hutzel Women’s Hospital/Harper University Hospital,
Wayne State University School of Medicine, Detroit, MI, USA
| | - Bogdan Panaitescu
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Valeria Garcia-Flores
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
| | - Sonia S. Hassan
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, USA and Detroit,
MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of
Medicine, Detroit, MI, USA
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Storisteanu DML, Pocock JM, Cowburn AS, Juss JK, Nadesalingam A, Nizet V, Chilvers ER. Evasion of Neutrophil Extracellular Traps by Respiratory Pathogens. Am J Respir Cell Mol Biol 2017; 56:423-431. [PMID: 27854516 DOI: 10.1165/rcmb.2016-0193ps] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The release of neutrophil extracellular traps (NETs) is a major immune mechanism intended to capture pathogens. These histone- and protease-coated DNA structures are released by neutrophils in response to a variety of stimuli, including respiratory pathogens, and have been identified in the airways of patients with respiratory infection, cystic fibrosis, acute lung injury, primary graft dysfunction, and chronic obstructive pulmonary disease. NET production has been demonstrated in the lungs of mice infected with Staphylococcus aureus, Klebsiella pneumoniae, and Aspergillus fumigatus. Since the discovery of NETs over a decade ago, evidence that "NET evasion" might act as an immune protection strategy among respiratory pathogens, including group A Streptococcus, Bordetella pertussis, and Haemophilus influenzae, has been growing, with the majority of these studies being published in the past 2 years. Evasion strategies fall into three main categories: inhibition of NET release by down-regulating host inflammatory responses; degradation of NETs using pathogen-derived DNases; and resistance to the microbicidal components of NETs, which involves a variety of mechanisms, including encapsulation. Hence, the evasion of NETs appears to be a widespread strategy to allow pathogen proliferation and dissemination, and is currently a topic of intense research interest. This article outlines the evidence supporting the three main strategies of NET evasion-inhibition, degradation, and resistance-with particular reference to common respiratory pathogens.
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Affiliation(s)
| | | | - Andrew S Cowburn
- Departments of 1 Medicine and.,2 Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Jatinder K Juss
- Departments of 1 Medicine and.,3 Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada; and
| | | | - Victor Nizet
- 4 Department of Pediatrics, University of California-La Jolla, San Diego, California
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Hoppenbrouwers T, Autar ASA, Sultan AR, Abraham TE, van Cappellen WA, Houtsmuller AB, van Wamel WJB, van Beusekom HMM, van Neck JW, de Maat MPM. In vitro induction of NETosis: Comprehensive live imaging comparison and systematic review. PLoS One 2017; 12:e0176472. [PMID: 28486563 PMCID: PMC5423591 DOI: 10.1371/journal.pone.0176472] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 04/11/2017] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Multiple inducers of in vitro Neutrophil Extracellular Trap (NET) formation (NETosis) have been described. Since there is much variation in study design and results, our aim was to create a systematic review of NETosis inducers and perform a standardized in vitro study of NETosis inducers important in (cardiac) wound healing. METHODS In vitro NETosis was studied by incubating neutrophils with PMA, living and dead bacteria (S. aureus and E. coli), LPS, (activated) platelets (supernatant), glucose and calcium ionophore Ionomycin using 3-hour periods of time-lapse confocal imaging. RESULTS PMA is a consistent and potent inducer of NETosis. Ionomycin also consistently resulted in extrusion of DNA, albeit with a process that differs from the NETosis process induced by PMA. In our standardized experiments, living bacteria were also potent inducers of NETosis, but dead bacteria, LPS, (activated) platelets (supernatant) and glucose did not induce NETosis. CONCLUSION Our systematic review confirms that there is much variation in study design and results of NETosis induction. Our experimental results confirm that under standardized conditions, PMA, living bacteria and Ionomycin all strongly induce NETosis, but real-time confocal imaging reveal different courses of events.
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Affiliation(s)
- Tamara Hoppenbrouwers
- Department of Plastic and Reconstructive Surgery, Erasmus MC, Rotterdam, The Netherlands
- Department of Hematology, Erasmus MC, Rotterdam, The Netherlands
| | - Anouchska S. A. Autar
- Department of Hematology, Erasmus MC, Rotterdam, The Netherlands
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - Andi R. Sultan
- Department of Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Tsion E. Abraham
- Optical Imaging Center, Department of Pathology, Erasmus MC, Rotterdam, The Netherlands
| | | | | | - Willem J. B. van Wamel
- Department of Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | | | - Johan W. van Neck
- Department of Plastic and Reconstructive Surgery, Erasmus MC, Rotterdam, The Netherlands
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Pieper J, Locke M, Ruzaike G, Voigt S, Methner U, Berndt A. In vitro and in vivo generation of heterophil extracellular traps after Salmonella exposure. Vet Immunol Immunopathol 2017; 188:1-11. [PMID: 28615122 DOI: 10.1016/j.vetimm.2017.04.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 01/22/2023]
Abstract
The release of extracellular traps (ETs) by granulocytes is a unique strategy to stop the dissemination of microbial pathogens. This study was undertaken to elucidate the potential of avian granulocytes (heterophils) to form ETs that can arrest and kill Salmonella organisms. After in vitro exposure of isolated heterophils and in vivo infection of day-old chicks with Salmonella enterica subsp. enterica serovars Infantis (SI) or Enteritidis (SE), the generation of ETs as well as the trapping and survivability of Salmonella organisms in the ET meshwork were determined by means of microscopy and spectrophotometry. In vitro, heterophils were able to form ETs within 15min after SE and SI inoculation. At 120min and with a multiplicity of infection of 1 and 5, SI induced significantly more ETs and DNA release than SE. Both SE and SI were found to be associated with the ET structures. Live-dead staining showed most of the microorganisms within the extracellular scaffold alive. In vivo, heterophils were detected in cecal lumen of SE-, but not SI-infected chicks. In cecum of the SE-exposed chicks, ET formations were scarcely detected whereas intact heterophils with phagocytosed bacteria were frequently found. The results evidence the capability of heterophils to generate ETs after SE and SI exposure in vitro. However, an infection of chicks with Salmonella did not significantly induce the formation of ET structures in cecum. Thus, the process to form ETs (ETosis) seems not to be of special relevance for Salmonella defense within the cecal lumen of young chicks.
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Affiliation(s)
- Jana Pieper
- University of Applied Sciences, Department for Medical Engineering and Biotechnology, Jena, Germany
| | - Maria Locke
- Institute of Molecular Pathogenesis, 'Friedrich-Loeffler-Institut' (Federal Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany
| | - Gunda Ruzaike
- University of Applied Sciences, Department for Medical Engineering and Biotechnology, Jena, Germany
| | - Stefanie Voigt
- Friedrich-Schiller-University, Faculty of Biology and Pharmacy, Jena, Germany
| | - Ulrich Methner
- Institute of Bacterial Infections and Zoonoses, 'Friedrich-Loeffler-Institut' (Federal Institute for Animal Health), Jena, Germany
| | - Angela Berndt
- Institute of Molecular Pathogenesis, 'Friedrich-Loeffler-Institut' (Federal Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany.
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Kothary V, Doster RS, Rogers LM, Kirk LA, Boyd KL, Romano-Keeler J, Haley KP, Manning SD, Aronoff DM, Gaddy JA. Group B Streptococcus Induces Neutrophil Recruitment to Gestational Tissues and Elaboration of Extracellular Traps and Nutritional Immunity. Front Cell Infect Microbiol 2017; 7:19. [PMID: 28217556 PMCID: PMC5289994 DOI: 10.3389/fcimb.2017.00019] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/16/2017] [Indexed: 12/14/2022] Open
Abstract
Streptococcus agalactiae, or Group B Streptococcus (GBS), is a gram-positive bacterial pathogen associated with infection during pregnancy and is a major cause of morbidity and mortality in neonates. Infection of the extraplacental membranes surrounding the developing fetus, a condition known as chorioamnionitis, is characterized histopathologically by profound infiltration of polymorphonuclear cells (PMNs, neutrophils) and greatly increases the risk for preterm labor, stillbirth, or neonatal GBS infection. The advent of animal models of chorioamnionitis provides a powerful tool to study host-pathogen relationships in vivo and ex vivo. The purpose of this study was to evaluate the innate immune response elicited by GBS and evaluate how antimicrobial strategies elaborated by these innate immune cells affect bacteria. Our work using a mouse model of GBS ascending vaginal infection during pregnancy reveals that clinically isolated GBS has the capacity to invade reproductive tissues and elicit host immune responses including infiltration of PMNs within the choriodecidua and placenta during infection, mirroring the human condition. Upon interacting with GBS, murine neutrophils elaborate DNA-containing extracellular traps, which immobilize GBS and are studded with antimicrobial molecules including lactoferrin. Exposure of GBS to holo- or apo-forms of lactoferrin reveals that the iron-sequestration activity of lactoferrin represses GBS growth and viability in a dose-dependent manner. Together, these data indicate that the mouse model of ascending infection is a useful tool to recapitulate human models of GBS infection during pregnancy. Furthermore, this work reveals that neutrophil extracellular traps ensnare GBS and repress bacterial growth via deposition of antimicrobial molecules, which drive nutritional immunity via metal sequestration strategies.
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Affiliation(s)
- Vishesh Kothary
- Department of Medicine, Vanderbilt University School of Medicine Nashville, TN, USA
| | - Ryan S Doster
- Department of Medicine, Vanderbilt University Medical Center Nashville, TN, USA
| | - Lisa M Rogers
- Department of Medicine, Vanderbilt University Medical Center Nashville, TN, USA
| | - Leslie A Kirk
- Department of Medicine, Vanderbilt University Medical Center Nashville, TN, USA
| | - Kelli L Boyd
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center Nashville, TN, USA
| | - Joann Romano-Keeler
- Department of Pediatrics, Vanderbilt University Medical Center Nashville, TN, USA
| | - Kathryn P Haley
- Department of Medicine, Vanderbilt University Medical CenterNashville, TN, USA; Department of Biomedical Sciences, Grand Valley State UniversityGrand Rapids, MI, USA
| | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA
| | - David M Aronoff
- Department of Medicine, Vanderbilt University School of Medicine Nashville, TN, USA
| | - Jennifer A Gaddy
- Department of Medicine, Vanderbilt University Medical CenterNashville, TN, USA; Department of Veterans Affairs, Tennessee Valley Healthcare SystemsNashville, TN, USA
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Abstract
Antimicrobial peptides (AMPs), also known as host defense peptides, are small naturally occurring microbicidal molecules produced by the host innate immune response that function as a first line of defense to kill pathogenic microorganisms by inducing deleterious cell membrane damage. AMPs also possess signaling and chemoattractant activities and can modulate the innate immune response to enhance protective immunity or suppress inflammation. Human pathogens have evolved defense molecules and strategies to counter and survive the AMPs released by host immune cells such as neutrophils and macrophages. Here, we review the various mechanisms used by human bacterial pathogens to resist AMP-mediated killing, including surface charge modification, active efflux, alteration of membrane fluidity, inactivation by proteolytic digestion, and entrapment by surface proteins and polysaccharides. Enhanced understanding of AMP resistance at the molecular level may offer insight into the mechanisms of bacterial pathogenesis and augment the discovery of novel therapeutic targets and drug design for the treatment of recalcitrant multidrug-resistant bacterial infections.
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48
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Boldenow E, Gendrin C, Ngo L, Bierle C, Vornhagen J, Coleman M, Merillat S, Armistead B, Whidbey C, Alishetti V, Santana-Ufret V, Ogle J, Gough M, Srinouanprachanh S, MacDonald JW, Bammler TK, Bansal A, Liggitt HD, Rajagopal L, Adams Waldorf KM. Group B Streptococcus circumvents neutrophils and neutrophil extracellular traps during amniotic cavity invasion and preterm labor. Sci Immunol 2016; 1:1/4/eaah4576. [PMID: 27819066 DOI: 10.1126/sciimmunol.aah4576] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Preterm birth is a leading cause of neonatal morbidity and mortality. Although microbial invasion of the amniotic cavity (MIAC) is associated with the majority of early preterm births, the temporal events that occur during MIAC and preterm labor are not known. Group B Streptococci (GBS) are β-hemolytic, gram-positive bacteria, which commonly colonize the vagina but have been recovered from the amniotic fluid in preterm birth cases. To understand temporal events that occur during MIAC, we utilized a unique chronically catheterized nonhuman primate model that closely emulates human pregnancy. This model allows monitoring of uterine contractions, timing of MIAC and immune responses during pregnancy-associated infections. Here, we show that adverse outcomes such as preterm labor, MIAC, and fetal sepsis were observed more frequently during infection with hemolytic GBS when compared to nonhemolytic GBS. Although MIAC was associated with systematic progression in chorioamnionitis beginning with chorionic vasculitis and progressing to neutrophilic infiltration, the ability of the GBS hemolytic pigment toxin to induce neutrophil cell death and subvert killing by neutrophil extracellular traps (NETs) in placental membranes in vivo facilitated MIAC and fetal injury. Furthermore, compared to maternal neutrophils, fetal neutrophils exhibit decreased neutrophil elastase activity and impaired phagocytic functions to GBS. Collectively, our studies demonstrate how a unique bacterial hemolytic lipid toxin enables GBS to circumvent neutrophils and NETs in placental membranes to induce fetal injury and preterm labor.
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Affiliation(s)
- Erica Boldenow
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Claire Gendrin
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Lisa Ngo
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Craig Bierle
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Jay Vornhagen
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America; Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Michelle Coleman
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Sean Merillat
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Blair Armistead
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America; Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Christopher Whidbey
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America; Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Varchita Alishetti
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Veronica Santana-Ufret
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Jason Ogle
- Washington National Primate Center, University of Washington, Seattle, Washington, United States of America
| | - Michael Gough
- Washington National Primate Center, University of Washington, Seattle, Washington, United States of America
| | - Sengkeo Srinouanprachanh
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - James W MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Aasthaa Bansal
- Department of Pharmacy, University of Washington, Seattle, Washington, United States of America
| | - H Denny Liggitt
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lakshmi Rajagopal
- Department of Pediatric Infectious Diseases, University of Washington and Seattle Children's Research Institute, Seattle, Washington, United States of America; Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Kristina M Adams Waldorf
- Department of Obstetrics & Gynecology, University of Washington, Seattle, Washington, United States of America
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Doke M, Fukamachi H, Morisaki H, Arimoto T, Kataoka H, Kuwata H. Nucleases from Prevotella intermedia can degrade neutrophil extracellular traps. Mol Oral Microbiol 2016; 32:288-300. [PMID: 27476978 PMCID: PMC5516193 DOI: 10.1111/omi.12171] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2016] [Indexed: 01/19/2023]
Abstract
Periodontitis is an inflammatory disease caused by periodontal bacteria in subgingival plaque. These bacteria are able to colonize the periodontal region by evading the host immune response. Neutrophils, the host's first line of defense against infection, use various strategies to kill invading pathogens, including neutrophil extracellular traps (NETs). These are extracellular net‐like fibers comprising DNA and antimicrobial components such as histones, LL‐37, defensins, myeloperoxidase, and neutrophil elastase from neutrophils that disarm and kill bacteria extracellularly. Bacterial nuclease degrades the NETs to escape NET killing. It has now been shown that extracellular nucleases enable bacteria to evade this host antimicrobial mechanism, leading to increased pathogenicity. Here, we compared the DNA degradation activity of major Gram‐negative periodontopathogenic bacteria, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. We found that Pr. intermedia showed the highest DNA degradation activity. A genome search of Pr. intermedia revealed the presence of two genes, nucA and nucD, putatively encoding secreted nucleases, although their enzymatic and biological activities are unknown. We cloned nucA‐ and nucD‐encoding nucleases from Pr. intermedia ATCC 25611 and characterized their gene products. Recombinant NucA and NucD digested DNA and RNA, which required both Mg2+ and Ca2+ for optimal activity. In addition, NucA and NucD were able to degrade the DNA matrix comprising NETs.
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Affiliation(s)
- M Doke
- Department of Oral Microbiology and Immunology, Showa University School of Dentistry, Shinagawa, Tokyo, Japan
| | - H Fukamachi
- Department of Oral Microbiology and Immunology, Showa University School of Dentistry, Shinagawa, Tokyo, Japan
| | - H Morisaki
- Department of Oral Microbiology and Immunology, Showa University School of Dentistry, Shinagawa, Tokyo, Japan
| | - T Arimoto
- Department of Oral Microbiology and Immunology, Showa University School of Dentistry, Shinagawa, Tokyo, Japan
| | - H Kataoka
- Department of Oral Microbiology and Immunology, Showa University School of Dentistry, Shinagawa, Tokyo, Japan
| | - H Kuwata
- Department of Oral Microbiology and Immunology, Showa University School of Dentistry, Shinagawa, Tokyo, Japan
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50
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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: 191] [Impact Index Per Article: 23.9] [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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