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Chan R, Buckley PT, O'Malley A, Sause WE, Alonzo F, Lubkin A, Boguslawski KM, Payne A, Fernandez J, Strohl WR, Whitaker B, Lynch AS, Torres VJ. Identification of biologic agents to neutralize the bicomponent leukocidins of Staphylococcus aureus. Sci Transl Med 2020; 11:11/475/eaat0882. [PMID: 30651319 DOI: 10.1126/scitranslmed.aat0882] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 01/22/2018] [Accepted: 12/17/2018] [Indexed: 12/12/2022]
Abstract
A key aspect underlying the severity of infections caused by Staphylococcus aureus is the abundance of virulence factors that the pathogen uses to thwart critical components of the human immune response. One such mechanism involves the destruction of host immune cells by cytolytic toxins secreted by S. aureus, including five bicomponent leukocidins: PVL, HlgAB, HlgCB, LukED, and LukAB. Purified leukocidins can lyse immune cells ex vivo, and systemic injections of purified LukED or HlgAB can acutely kill mice. Here, we describe the generation and characterization of centyrins that bind S. aureus leukocidins with high affinity and protect primary human immune cells from toxin-mediated cytolysis. Centyrins are small protein scaffolds derived from the fibronectin type III-binding domain of the human protein tenascin-C. Although centyrins are potent in tissue culture assays, their short serum half-lives limit their efficacies in vivo. By extending the serum half-lives of centyrins through their fusion to an albumin-binding consensus domain, we demonstrate the in vivo efficacy of these biologics in a murine intoxication model and in models of both prophylactic and therapeutic treatment of live S. aureus systemic infections. These biologics that target S. aureus virulence factors have potential for treating and preventing serious staphylococcal infections.
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Affiliation(s)
- Rita Chan
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Peter T Buckley
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Aidan O'Malley
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - William E Sause
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Francis Alonzo
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Ashira Lubkin
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Kristina M Boguslawski
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Angela Payne
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Jeffrey Fernandez
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - William R Strohl
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Brian Whitaker
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Anthony Simon Lynch
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA.
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA.
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Host-Receptor Post-Translational Modifications Refine Staphylococcal Leukocidin Cytotoxicity. Toxins (Basel) 2020; 12:toxins12020106. [PMID: 32041354 PMCID: PMC7076806 DOI: 10.3390/toxins12020106] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 02/02/2020] [Accepted: 02/05/2020] [Indexed: 01/23/2023] Open
Abstract
Staphylococcal bi-component pore-forming toxins, also known as leukocidins, target and lyse human phagocytes in a receptor-dependent manner. S-components of the leukocidins Panton-Valentine leukocidin (PVL), γ-haemolysin AB (HlgAB) and CB (HlgCB), and leukocidin ED (LukED) specifically employ receptors that belong to the class of G-protein coupled receptors (GPCRs). Although these receptors share a common structural architecture, little is known about the conserved characteristics of the interaction between leukocidins and GPCRs. In this study, we investigated host cellular pathways contributing to susceptibility towards S. aureus leukocidin cytotoxicity. We performed a genome-wide CRISPR/Cas9 library screen for toxin-resistance in U937 cells sensitized to leukocidins by ectopic expression of different GPCRs. Our screen identifies post-translational modification (PTM) pathways involved in the sulfation and sialylation of the leukocidin-receptors. Subsequent validation experiments show differences in the impact of PTM moieties on leukocidin toxicity, highlighting an additional layer of refinement and divergence in the staphylococcal host-pathogen interface. Leukocidin receptors may serve as targets for anti-staphylococcal interventions and understanding toxin-receptor interactions will facilitate the development of innovative therapeutics. Variations in the genes encoding PTM pathways could provide insight into observed differences in susceptibility of humans to infections with S. aureus.
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Astley R, Miller FC, Mursalin MH, Coburn PS, Callegan MC. An Eye on Staphylococcus aureus Toxins: Roles in Ocular Damage and Inflammation. Toxins (Basel) 2019; 11:E356. [PMID: 31248125 PMCID: PMC6628431 DOI: 10.3390/toxins11060356] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen of the eye, capable of infecting external tissues such as the tear duct, conjunctiva, and the cornea, as well the inner and more delicate anterior and posterior chambers. S. aureus produces numerous toxins and enzymes capable of causing profound damage to tissues and organs, as well as modulating the immune response to these infections. Unfortunately, in the context of ocular infections, this can mean blindness for the patient. The role of α-toxin in corneal infection (keratitis) and infection of the interior of the eye (endophthalmitis) has been well established by comparing virulence in animal models and α-toxin-deficient isogenic mutants with their wild-type parental strains. The importance of other toxins, such as β-toxin, γ-toxin, and Panton-Valentine leukocidin (PVL), have been analyzed to a lesser degree and their roles in eye infections are less clear. Other toxins such as the phenol-soluble modulins have yet to be examined in any animal models for their contributions to virulence in eye infections. This review discusses the state of current knowledge of the roles of S. aureus toxins in eye infections and the controversies existing as a result of the use of different infection models. The strengths and limitations of these ocular infection models are discussed, as well as the need for physiological relevance in the study of staphylococcal toxins in these models.
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Affiliation(s)
- Roger Astley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Frederick C Miller
- Department of Cell Biology and Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Md Huzzatul Mursalin
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Phillip S Coburn
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Michelle C Callegan
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd., DMEI PA-418, Oklahoma City, OK 73104, USA.
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The Role of Streptococcal and Staphylococcal Exotoxins and Proteases in Human Necrotizing Soft Tissue Infections. Toxins (Basel) 2019; 11:toxins11060332. [PMID: 31212697 PMCID: PMC6628391 DOI: 10.3390/toxins11060332] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/04/2019] [Accepted: 06/10/2019] [Indexed: 12/31/2022] Open
Abstract
Necrotizing soft tissue infections (NSTIs) are critical clinical conditions characterized by extensive necrosis of any layer of the soft tissue and systemic toxicity. Group A streptococci (GAS) and Staphylococcus aureus are two major pathogens associated with monomicrobial NSTIs. In the tissue environment, both Gram-positive bacteria secrete a variety of molecules, including pore-forming exotoxins, superantigens, and proteases with cytolytic and immunomodulatory functions. The present review summarizes the current knowledge about streptococcal and staphylococcal toxins in NSTIs with a special focus on their contribution to disease progression, tissue pathology, and immune evasion strategies.
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Abstract
Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Despite broad literature including basic and translational scientific studies, many gaps in our understanding of host-pathogen interactions remain. In this review, pathogen virulence factors that drive lung infection and injury are discussed in relation to their associated host immune pathways. CAP epidemiology is considered, with a focus on Staphylococcus aureus and Streptococcus pneumoniae as primary pathogens. Bacterial factors involved in nasal colonization and subsequent virulence are illuminated. A particular emphasis is placed on bacterial pore-forming toxins, host cell death, and inflammasome activation. Identified host-pathogen interactions are then examined by linking pathogen factors to aberrant host response pathways in the context of acute lung injury in both primary and secondary infection. While much is known regarding bacterial virulence and host immune responses, CAP management is still limited to mostly supportive care. It is likely that improvements in therapy will be derived from combinatorial targeting of both pathogen virulence factors and host immunomodulation.
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Tam K, Torres VJ. Staphylococcus aureus Secreted Toxins and Extracellular Enzymes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0039-2018. [PMID: 30873936 PMCID: PMC6422052 DOI: 10.1128/microbiolspec.gpp3-0039-2018] [Citation(s) in RCA: 197] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a formidable pathogen capable of causing infections in different sites of the body in a variety of vertebrate animals, including humans and livestock. A major contribution to the success of S. aureus as a pathogen is the plethora of virulence factors that manipulate the host's innate and adaptive immune responses. Many of these immune modulating virulence factors are secreted toxins, cofactors for activating host zymogens, and exoenzymes. Secreted toxins such as pore-forming toxins and superantigens are highly inflammatory and can cause leukocyte cell death by cytolysis and clonal deletion, respectively. Coagulases and staphylokinases are cofactors that hijack the host's coagulation system. Exoenzymes, including nucleases and proteases, cleave and inactivate various immune defense and surveillance molecules, such as complement factors, antimicrobial peptides, and surface receptors that are important for leukocyte chemotaxis. Additionally, some of these secreted toxins and exoenzymes can cause disruption of endothelial and epithelial barriers through cell lysis and cleavage of junction proteins. A unique feature when examining the repertoire of S. aureus secreted virulence factors is the apparent functional redundancy exhibited by the majority of the toxins and exoenzymes. However, closer examination of each virulence factor revealed that each has unique properties that have important functional consequences. This chapter provides a brief overview of our current understanding of the major secreted virulence factors critical for S. aureus pathogenesis.
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Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
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57
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Lubkin A, Lee WL, Alonzo F, Wang C, Aligo J, Keller M, Girgis NM, Reyes-Robles T, Chan R, O'Malley A, Buckley P, Vozhilla N, Vasquez MT, Su J, Sugiyama M, Yeung ST, Coffre M, Bajwa S, Chen E, Martin P, Kim SY, Loomis C, Worthen GS, Shopsin B, Khanna KM, Weinstock D, Lynch AS, Koralov SB, Loke P, Cadwell K, Torres VJ. Staphylococcus aureus Leukocidins Target Endothelial DARC to Cause Lethality in Mice. Cell Host Microbe 2019; 25:463-470.e9. [PMID: 30799265 DOI: 10.1016/j.chom.2019.01.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/24/2018] [Accepted: 01/23/2019] [Indexed: 01/16/2023]
Abstract
The pathogenesis of Staphylococcus aureus is thought to depend on the production of pore-forming leukocidins that kill leukocytes and lyse erythrocytes. Two leukocidins, Leukocidin ED (LukED) and γ-Hemolysin AB (HlgAB), are necessary and sufficient to kill mice upon infection and toxin challenge. We demonstrate that LukED and HlgAB cause vascular congestion and derangements in vascular fluid distribution that rapidly cause death in mice. The Duffy antigen receptor for chemokines (DARC) on endothelial cells, rather than leukocytes or erythrocytes, is the critical target for lethality. Consistent with this, LukED and HlgAB injure primary human endothelial cells in a DARC-dependent manner, and mice with DARC-deficient endothelial cells are resistant to toxin-mediated lethality. During bloodstream infection in mice, DARC targeting by S. aureus causes increased tissue damage, organ dysfunction, and host death. The potential for S. aureus leukocidins to manipulate vascular integrity highlights the importance of these virulence factors.
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Affiliation(s)
- Ashira Lubkin
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Warren L Lee
- Keenan Research Centre, St Michael's Hospital, 30 Bond Street, Toronto, ON M5B 1W8, Canada; Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.
| | - Francis Alonzo
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Changsen Wang
- Keenan Research Centre, St Michael's Hospital, 30 Bond Street, Toronto, ON M5B 1W8, Canada
| | - Jason Aligo
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA
| | - Matthew Keller
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Natasha M Girgis
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Tamara Reyes-Robles
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Rita Chan
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Aidan O'Malley
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Peter Buckley
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA
| | - Nikollaq Vozhilla
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Marilyn T Vasquez
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Johnny Su
- Keenan Research Centre, St Michael's Hospital, 30 Bond Street, Toronto, ON M5B 1W8, Canada
| | - Michael Sugiyama
- Keenan Research Centre, St Michael's Hospital, 30 Bond Street, Toronto, ON M5B 1W8, Canada
| | - Stephen T Yeung
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Maryaline Coffre
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Sofia Bajwa
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Eric Chen
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Patricia Martin
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Sang Y Kim
- Department of Pathology, New York University School of Medicine, New York, NY, USA; Office of Collaborative Sciences, NYU School of Medicine, New York, NY, USA; Department of Pathology, NYU School of Medicine, New York, NY, USA
| | - Cynthia Loomis
- Department of Pathology, New York University School of Medicine, New York, NY, USA; Office of Collaborative Sciences, NYU School of Medicine, New York, NY, USA; Department of Pathology, NYU School of Medicine, New York, NY, USA
| | - G Scott Worthen
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, USA; Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Bo Shopsin
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA; Division of Infectious Diseases, Department of Medicine, NYU School of Medicine, New York, NY 10016, USA
| | - Kamal M Khanna
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Daniel Weinstock
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA
| | - Anthony Simon Lynch
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA
| | - Sergei B Koralov
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - P'ng Loke
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Ken Cadwell
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
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Adaptation of the Staphylococcus aureus leukocidin LukGH for the rabbit host by protein engineering. Biochem J 2019; 476:275-292. [PMID: 30559327 DOI: 10.1042/bcj20180691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 12/12/2018] [Accepted: 12/14/2018] [Indexed: 02/07/2023]
Abstract
Host defense against Staphylococcus aureus greatly depends on bacterial clearance by phagocytic cells. LukGH (or LukAB) is the most potent staphylococcal leukocidin towards human phagocytes in vitro, but its role in pathogenesis is obscured by the lack of suitable small animal models because LukGH has limited or no cytotoxicity towards rodent and rabbit compared with human polymorphonuclear cells (PMNs) likely due to an impaired interaction with its cellular receptor, CD11b. We aimed at adapting LukGH for the rabbit host by improving binding to the rabbit homolog of CD11b, specifically its I-domain (CD11b-I). Targeted amino acid substitutions were introduced into the LukH polypeptide to map its receptor interaction site(s). We found that the binding affinity of LukGH variants to the human and rabbit CD11b-I correlated well with their PMN cytotoxicity. Importantly, we identified LukGH variants with significantly improved cytotoxicity towards rabbit PMNs, when expressed recombinantly (10-15-fold) or by engineered S. aureus strains. These findings support the development of small animal models of S. aureus infection with the potential for demonstrating the importance of LukGH in pathogenesis.
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59
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Buchan KD, Foster SJ, Renshaw SA. Staphylococcus aureus: setting its sights on the human innate immune system. MICROBIOLOGY-SGM 2019; 165:367-385. [PMID: 30625113 DOI: 10.1099/mic.0.000759] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Staphylococcus aureus has colonized humans for at least 10 000 years, and today inhabits roughly a third of the population. In addition, S. aureus is a major pathogen that is responsible for a significant disease burden, ranging in severity from mild skin and soft-tissue infections to life-threatening endocarditis and necrotizing pneumonia, with treatment often hampered by resistance to commonly available antibiotics. Underpinning its versatility as a pathogen is its ability to evade the innate immune system. S. aureus specifically targets innate immunity to establish and sustain infection, utilizing a large repertoire of virulence factors to do so. Using these factors, S. aureus can resist phagosomal killing, impair complement activity, disrupt cytokine signalling and target phagocytes directly using proteolytic enzymes and cytolytic toxins. Although most of these virulence factors are well characterized, their importance during infection is less clear, as many display species-specific activity against humans or against animal hosts, including cows, horses and chickens. Several staphylococcal virulence factors display species specificity for components of the human innate immune system, with as few as two amino acid changes reducing binding affinity by as much as 100-fold. This represents a major issue for studying their roles during infection, which cannot be examined without the use of humanized infection models. This review summarizes the major factors S. aureus uses to impair the innate immune system, and provides an in-depth look into the host specificity of S. aureus and how this problem is being approached.
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Affiliation(s)
- Kyle D Buchan
- 1The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Simon J Foster
- 2Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Stephen A Renshaw
- 1The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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60
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Jing C, Liu C, Liu F, Gao Y, Liu Y, Guan Z, Xuan B, Yu Y, Yang G. Novel human monoclonal antibodies targeting the F subunit of leukocidins reduce disease progression and mortality caused by Staphylococcus aureus. BMC Microbiol 2018; 18:181. [PMID: 30419818 PMCID: PMC6233355 DOI: 10.1186/s12866-018-1312-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 10/11/2018] [Indexed: 01/17/2023] Open
Abstract
Background Staphylococcus aureus is a leading cause of Gram-positive bacterial infections worldwide; however, the treatment of S. aureus infection has become increasingly difficult due to the prevalence of methicillin-resistant S. aureus strains, highlighting the urgent need for the development of novel strategies. The complexity of S. aureus pathogenesis relies on virulence factors. Recent studies have demonstrated that leukocidins expressed by the majority of clinical isolates play important roles in the pathogenesis of S. aureus. Results In this study, we developed three human monoclonal antibodies against all F-components of leukocidins HlgABC, LukSF, and LukED with high affinity. These antibodies were found to be capable of blocking leukocidin-mediated cell lysis in vitro. Furthermore, the antibodies dramatically reduced disease progression and mortality after S. aureus infection in vivo. Conclusions Our findings revealed that neutralizing bicomponent leukocidins may be a promising strategy to combat infections caused by S. aureus. Electronic supplementary material The online version of this article (10.1186/s12866-018-1312-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chendi Jing
- Department of Infectious Diseases, Peking University First Hospital, Beijing, 100034, China
| | - Chenghua Liu
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Fangjie Liu
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yaping Gao
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yu Liu
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Zhangchun Guan
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Bo Xuan
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yanyan Yu
- Department of Infectious Diseases, Peking University First Hospital, Beijing, 100034, China.
| | - Guang Yang
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China. .,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China.
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Abstract
ABSTRACT
Fulminant staphylococcal infection indicates an explosive, intense, and severe infection occurring in a patient whose previous condition and antecedent would never have caused any anticipation of life-threatening development. This includes necrotizing pneumonia, necrotizing fasciitis, and to some extent toxic shock syndrome and infective endocarditis. In the three former diseases, toxin production plays a major role whereas in the latter (fulminant presentation of infective endocarditis), association with any particular toxinic profile has never been demonstrated. This article reviews the clinical, pathophysiological, and therapeutic aspects of these diseases.
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62
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Peng Z, Shibata N, Tada H, Kaneko J. Cytotoxicity analysis of staphylococcal bi-component β-pore forming toxins using the CHO cells expressing human lymphocyte receptor CCR5. Biosci Biotechnol Biochem 2018; 82:2094-2097. [PMID: 30185128 DOI: 10.1080/09168451.2018.1515614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
CCR5-mediated cytotoxicity of staphylococcal bi-component toxins was investigated using human CCR5-expressing CHO cells. Cytotoxicity of rim domain loop-exchange mutants between LukE and Hlg2 indicated that loop-4 of LukE is essential for cytotoxicity in combination with LukD. Interestingly, Hlg2 showed LukF-dependent CCR5-mediated cytotoxicity, suggesting that the F-components of toxins also play a role in the cell-specific cytotoxicity.
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Affiliation(s)
- Zhao Peng
- a Department of Microbial Biotechnology , Graduate School of Agricultural Science, Tohoku University , Sendai , Japan
| | - Nao Shibata
- b Exploratory Research Laboratories , Tsukuba Research Institute, ONO pharmaceutical Co., LTD , Tsukuba , Japan
| | - Hideaki Tada
- b Exploratory Research Laboratories , Tsukuba Research Institute, ONO pharmaceutical Co., LTD , Tsukuba , Japan
| | - Jun Kaneko
- a Department of Microbial Biotechnology , Graduate School of Agricultural Science, Tohoku University , Sendai , Japan
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Darisipudi MN, Nordengrün M, Bröker BM, Péton V. Messing with the Sentinels-The Interaction of Staphylococcus aureus with Dendritic Cells. Microorganisms 2018; 6:microorganisms6030087. [PMID: 30111706 PMCID: PMC6163568 DOI: 10.3390/microorganisms6030087] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/12/2018] [Accepted: 08/14/2018] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a dangerous pathogen as well as a frequent colonizer, threatening human health worldwide. Protection against S. aureus infection is challenging, as the bacteria have sophisticated strategies to escape the host immune response. To maintain equilibrium with S. aureus, both innate and adaptive immune effector mechanisms are required. Dendritic cells (DCs) are critical players at the interface between the two arms of the immune system, indispensable for inducing specific T cell responses. In this review, we highlight the importance of DCs in mounting innate as well as adaptive immune responses against S. aureus with emphasis on their role in S. aureus-induced respiratory diseases. We also review what is known about mechanisms that S. aureus has adopted to evade DCs or manipulate these cells to its advantage.
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Affiliation(s)
- Murthy N Darisipudi
- Department of Immunology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße DZ7, D-17475 Greifswald, Germany.
| | - Maria Nordengrün
- Department of Immunology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße DZ7, D-17475 Greifswald, Germany.
| | - Barbara M Bröker
- Department of Immunology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße DZ7, D-17475 Greifswald, Germany.
| | - Vincent Péton
- Department of Immunology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße DZ7, D-17475 Greifswald, Germany.
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64
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Peng Z, Takeshita M, Shibata N, Tada H, Tanaka Y, Kaneko J. Rim domain loops of staphylococcal β-pore forming bi-component toxin S-components recognize target human erythrocytes in a coordinated manner. J Biochem 2018; 164:93-102. [PMID: 29474554 DOI: 10.1093/jb/mvy030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/07/2018] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus bi-component pore-forming toxins consist of S- and F-components, and form hetero-octameric beta-barrel pores on target blood cell membranes. Among them, γ-haemolysin (Hlg2 and F-component of Luk (LukF)) and LukED (LukE and LukD) possess haemolytic activity, whereas the Panton-Valentine leukocidin (LukS-PV and LukF-PV) does not lyse human erythrocytes. Here, we focussed on four loop structures in the rim domain of S-component, namely loops -1, -2, -3 and -4, and found that replacement of Loop-4 in both Hlg2 and LukE with that of LukS-PV abolished their haemolytic activity. Furthermore, LukS-PV gained haemolytic activity by Loop-4 exchange with Hlg2 or LukE, suggesting that Loop-4 of these S-components determined erythrocyte specificity. LOOP-1 and -2 enhanced the erythrocytes-binding ability of both components. Although Hlg2 and LukE recognize Duffy antigen receptor for chemokines on human erythrocytes, the ability of Loop-4 was not complementary between Hlg2 and LukE. Exchange of Hlg2 with LukE Loop-4 showed weaker activity than intact Hlg2, and LukE mutant with Hlg2 Loop-4 lost its haemolytic activity in combination of LukD. Interestingly, the haemolytic activities of these Loop-4 exchange mutants were affected by F-component, namely LukF enhanced haemolytic activities of these Hlg2 and LukE Loop-4 mutants, and also haemolytic activity of LukS-PV mutant with LukE Loop-4.
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Affiliation(s)
- Zhao Peng
- Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Miyu Takeshita
- Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Nao Shibata
- Exploratory Research Laboratories, Tsukuba Research Institute, ONO Pharmaceutical Co., LTD, 17-2 Wadai, Tsukuba 300-4247, Japan
| | - Hideaki Tada
- Exploratory Research Laboratories, Tsukuba Research Institute, ONO Pharmaceutical Co., LTD, 17-2 Wadai, Tsukuba 300-4247, Japan
| | - Yoshikazu Tanaka
- Laboratory of Applied Biological Molecular Science, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Jun Kaneko
- Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan
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He C, Xu S, Zhao H, Hu F, Xu X, Jin S, Yang H, Gong F, Liu Q. Leukotoxin and pyrogenic toxin Superantigen gene backgrounds in bloodstream and wound Staphylococcus aureus isolates from eastern region of China. BMC Infect Dis 2018; 18:395. [PMID: 30103694 PMCID: PMC6090790 DOI: 10.1186/s12879-018-3297-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 08/01/2018] [Indexed: 11/10/2022] Open
Abstract
Background The bicomponent leukotoxins and the pyrogenic toxin superantigens (PTSAgs) are important virulence factors of Staphylococcus aureus. It is necessary to survey the prevalence and expression of these toxin-encoding genes for understanding the possible pathogenic capacity of S. aureus to cause disease. Methods Five leukotoxin genes and thirteen PTSAg determinants were detected for 177 S. aureus isolates from blood (n = 88) and wound (n = 89) infections by Polymerase Chain Reaction (PCR). The expression of leukotoxin ED (lukED) was determined by quantitative real-time PCR (qRT-PCR). The genetic backgrounds of isolates were analyzed by Staphylococcal Cassette Chromosome mec (SCCmec) typing (for methicillin-resistant S. aureus isolates), Pulsed-Field Gel Electrophoresis (PFGE), accessory gene regulator (agr) typing and Multilocus Sequence Typing (MLST, for representative isolates based on PFGE type) methods. Results 99.4% (176/177) isolates contained at least one of leukotoxin genes. Among them, 94.9% (168/177), 81.4% (144/177) and 67.8% (120/177) isolates harbored hlgBC, lukED and lukAB, respectively. Compared to leukotoxin genes, there was a relatively lower overall prevalence of PTSAg genes [99.4% versus 72.9% (129/177), P < 0.001], and they were organized in 59 patterns, with the most common combination of the egc cluster with or without other PTSAg genes. Genetic analysis showed the distributions of certain toxin genes were associated with the genetic backgrounds of isolates. The egc cluster was a common feature of CC5 isolates, among which ST5 and ST764 isolates harbored more PTSAg genes. The lukED was not present in ST398 isolates, and its expression was quite different among isolates. No significant correlations were observed between the lukED expression levels of strains and the ST or agr types. Conclusions The present study elucidated the distribution of leukotoxin and PTSAg genes and the expression of lukED in blood and wound isolates, and analyzed the relationship between them with genetic characteristics of isolates. These data improve the current understanding of the possible pathogenicity of S. aureus. Electronic supplementary material The online version of this article (10.1186/s12879-018-3297-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chunyan He
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200080, China
| | - Su Xu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, 200080, China
| | - Huanqiang Zhao
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200080, China
| | - Fupin Hu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, 200080, China
| | - Xiaogang Xu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, 200080, China
| | - Shu Jin
- Experimental Research Center, Shanghai People's Hospital of Putuo District, Shanghai, 200080, China
| | - Han Yang
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200080, China
| | - Fang Gong
- Department of Clinical Laboratory, the Third Hospital Affiliated to Nantong University, Wuxi, 226000, China
| | - Qingzhong Liu
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200080, China.
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Production of Staphylococcal Complement Inhibitor (SCIN) and Other Immune Modulators during the Early Stages of Staphylococcus aureus Biofilm Formation in a Mammalian Cell Culture Medium. Infect Immun 2018; 86:IAI.00352-18. [PMID: 29784858 DOI: 10.1128/iai.00352-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 02/07/2023] Open
Abstract
Immune modulators are known to be produced by matured biofilms and during different stages of planktonic growth of Staphylococcus aureus Little is known about immune modulator production during the early stages of biofilm formation, thus raising the following question: how does S. aureus protect itself from the innate immune responses at these stages? Therefore, we determined the production of the following immune modulators: chemotaxis inhibitory protein of staphylococci (CHIPS); staphylococcal complement inhibitor (SCIN); formyl peptide receptor-like 1 inhibitor; gamma-hemolysin component B; leukocidins D, E, and S; staphylococcal superantigen-like proteins 1, 3, 5, and 9; and staphylococcal enterotoxin A. Production was determined during in vitro biofilm formation in Iscove's modified Dulbecco's medium at different time points using a competitive Luminex assay and mass spectrometry. Both methods demonstrated the production of the immune modulators SCIN and CHIPS during the early stages of biofilm formation. The green fluorescence protein promoter fusion technology confirmed scn (SCIN) and, to a lesser extent, chp (CHIPS) transcription during the early stages of biofilm formation. Furthermore, we found that SCIN could inhibit human complement activation induced by early biofilms, indicating that S. aureus is able to modulate the innate immune system already during the early stages of biofilm formation in vitro These results form a stepping stone toward elucidating the role of immune modulators in the establishment of biofilms in vivo and present opportunities to develop preventive strategies.
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67
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Staphylococcus aureus biofilms release leukocidins to elicit extracellular trap formation and evade neutrophil-mediated killing. Proc Natl Acad Sci U S A 2018; 115:7416-7421. [PMID: 29941565 DOI: 10.1073/pnas.1721949115] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bacterial biofilms efficiently evade immune defenses, greatly complicating the prognosis of chronic infections. How methicillin-resistant Staphylococcus aureus (MRSA) biofilms evade host immune defenses is largely unknown. This study describes some of the major mechanisms required for S. aureus biofilms to evade the innate immune response and provides evidence of key virulence factors required for survival and persistence of bacteria during chronic infections. Neutrophils are the most abundant white blood cells in circulation, playing crucial roles in the control and elimination of bacterial pathogens. Specifically, here we show that, unlike single-celled populations, S. aureus biofilms rapidly skew neutrophils toward neutrophil extracellular trap (NET) formation through the combined activity of leukocidins Panton-Valentine leukocidin and γ-hemolysin AB. By eliciting this response, S. aureus was able to persist, as the antimicrobial activity of released NETs was ineffective at clearing biofilm bacteria. Indeed, these studies suggest that NETs could inadvertently potentiate biofilm infections. Last, chronic infection in a porcine burn wound model clearly demonstrated that leukocidins are required for "NETosis" and facilitate bacterial survival in vivo.
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68
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Wolfmeier H, Mansour SC, Liu LT, Pletzer D, Draeger A, Babiychuk EB, Hancock REW. Liposomal Therapy Attenuates Dermonecrosis Induced by Community-Associated Methicillin-Resistant Staphylococcus aureus by Targeting α-Type Phenol-Soluble Modulins and α-Hemolysin. EBioMedicine 2018; 33:211-217. [PMID: 29936135 PMCID: PMC6085503 DOI: 10.1016/j.ebiom.2018.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/05/2018] [Accepted: 06/12/2018] [Indexed: 12/31/2022] Open
Abstract
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), typified by the pulse-field type USA300, is an emerging endemic pathogen that is spreading rapidly among healthy people. CA-MRSA causes skin and soft tissue infections, life-threatening necrotizing pneumonia and sepsis, and is remarkably resistant to many antibiotics. Here we show that engineered liposomes composed of naturally occurring sphingomyelin were able to sequester cytolytic toxins secreted by USA300 and prevent necrosis of human erythrocytes, peripheral blood mononuclear cells and bronchial epithelial cells. Mass spectrometric analysis revealed the capture by liposomes of phenol-soluble modulins, α-hemolysin and other toxins. Sphingomyelin liposomes prevented hemolysis induced by pure phenol-soluble modulin-α3, one of the main cytolytic components in the USA300 secretome. In contrast, sphingomyelin liposomes harboring a high cholesterol content (66 mol/%) were unable to protect human cells from phenol-soluble modulin-α3-induced lysis, however these liposomes efficiently sequestered the potent staphylococcal toxin α-hemolysin. In a murine cutaneous abscess model, a single dose of either type of liposomes was sufficient to significantly decrease tissue dermonecrosis. Our results provide further insights into the promising potential of tailored liposomal therapy in the battle against infectious diseases.
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Affiliation(s)
- Heidi Wolfmeier
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Sarah C Mansour
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Leo T Liu
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Annette Draeger
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3000 Bern, Switzerland
| | - Eduard B Babiychuk
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3000 Bern, Switzerland
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada.
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69
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Staphylococcus aureus Toxins and Their Molecular Activity in Infectious Diseases. Toxins (Basel) 2018; 10:toxins10060252. [PMID: 29921792 PMCID: PMC6024779 DOI: 10.3390/toxins10060252] [Citation(s) in RCA: 234] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/14/2018] [Accepted: 06/15/2018] [Indexed: 12/04/2022] Open
Abstract
Staphylococcus aureus is a microorganism resident in the skin and nasal membranes with a dreadful pathogenic potential to cause a variety of community and hospital-acquired infections. The frequency of these infections is increasing and their treatment is becoming more difficult. The ability of S. aureus to form biofilms and the emergence of multidrug-resistant strains are the main reasons determining the challenge in dealing with these infections. S. aureus' infectious capacity and its success as a pathogen is related to the expression of virulence factors, among which the production of a wide variety of toxins is highlighted. For this reason, a better understanding of S. aureus toxins is needed to enable the development of new strategies to reduce their production and consequently improve therapeutic approaches. This review focuses on understanding the toxin-based pathogenesis of S. aureus and their role on infectious diseases.
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70
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Tromp AT, Van Gent M, Abrial P, Martin A, Jansen JP, De Haas CJC, Van Kessel KPM, Bardoel BW, Kruse E, Bourdonnay E, Boettcher M, McManus MT, Day CJ, Jennings MP, Lina G, Vandenesch F, Van Strijp JAG, Lebbink RJ, Haas PJA, Henry T, Spaan AN. Human CD45 is an F-component-specific receptor for the staphylococcal toxin Panton-Valentine leukocidin. Nat Microbiol 2018; 3:708-717. [PMID: 29736038 DOI: 10.1038/s41564-018-0159-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 04/13/2018] [Indexed: 12/22/2022]
Abstract
The staphylococcal bi-component leukocidins Panton-Valentine leukocidin (PVL) and γ-haemolysin CB (HlgCB) target human phagocytes. Binding of the toxins' S-components to human complement C5a receptor 1 (C5aR1) contributes to cellular tropism and human specificity of PVL and HlgCB. To investigate the role of both leukocidins during infection, we developed a human C5aR1 knock-in (hC5aR1KI) mouse model. HlgCB, but unexpectedly not PVL, contributed to increased bacterial loads in tissues of hC5aR1KI mice. Compared to humans, murine hC5aR1KI neutrophils showed a reduced sensitivity to PVL, which was mediated by the toxin's F-component LukF-PV. By performing a genome-wide CRISPR-Cas9 screen, we identified CD45 as a receptor for LukF-PV. The human-specific interaction between LukF-PV and CD45 provides a molecular explanation for resistance of hC5aR1KI mouse neutrophils to PVL and probably contributes to the lack of a PVL-mediated phenotype during infection in these mice. This study demonstrates an unsuspected role of the F-component in driving the sensitivity of human phagocytes to PVL.
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Affiliation(s)
- Angelino T Tromp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Michiel Van Gent
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Pauline Abrial
- CIRI, Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, Hospices Civils de Lyon, Lyon, France
| | - Amandine Martin
- CIRI, Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, Hospices Civils de Lyon, Lyon, France
| | - Joris P Jansen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Carla J C De Haas
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kok P M Van Kessel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bart W Bardoel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Elisabeth Kruse
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Emilie Bourdonnay
- CIRI, Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, Hospices Civils de Lyon, Lyon, France
| | - Michael Boettcher
- Department of Microbiology and Immunology, UCSF Diabetes Center, Keck Center for Noncoding RNA, University of California, San Francisco, San Francisco, CA, USA
| | - Michael T McManus
- Department of Microbiology and Immunology, UCSF Diabetes Center, Keck Center for Noncoding RNA, University of California, San Francisco, San Francisco, CA, USA
| | - Christopher J Day
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Gérard Lina
- CIRI, Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, Hospices Civils de Lyon, Lyon, France
| | - François Vandenesch
- CIRI, Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, Hospices Civils de Lyon, Lyon, France
| | - Jos A G Van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Robert Jan Lebbink
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Pieter-Jan A Haas
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Thomas Henry
- CIRI, Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, Hospices Civils de Lyon, Lyon, France.
| | - András N Spaan
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands. .,St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA.
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71
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Hughes CE, Nibbs RJB. A guide to chemokines and their receptors. FEBS J 2018; 285:2944-2971. [PMID: 29637711 PMCID: PMC6120486 DOI: 10.1111/febs.14466] [Citation(s) in RCA: 721] [Impact Index Per Article: 120.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 03/25/2018] [Accepted: 04/03/2018] [Indexed: 12/12/2022]
Abstract
The chemokines (or chemotactic cytokines) are a large family of small, secreted proteins that signal through cell surface G protein-coupled heptahelical chemokine receptors. They are best known for their ability to stimulate the migration of cells, most notably white blood cells (leukocytes). Consequently, chemokines play a central role in the development and homeostasis of the immune system, and are involved in all protective or destructive immune and inflammatory responses. Classically viewed as inducers of directed chemotactic migration, it is now clear that chemokines can stimulate a variety of other types of directed and undirected migratory behavior, such as haptotaxis, chemokinesis, and haptokinesis, in addition to inducing cell arrest or adhesion. However, chemokine receptors on leukocytes can do more than just direct migration, and these molecules can also be expressed on, and regulate the biology of, many nonleukocytic cell types. Chemokines are profoundly affected by post-translational modification, by interaction with the extracellular matrix (ECM), and by binding to heptahelical 'atypical' chemokine receptors that regulate chemokine localization and abundance. This guide gives a broad overview of the chemokine and chemokine receptor families; summarizes the complex physical interactions that occur in the chemokine network; and, using specific examples, discusses general principles of chemokine function, focusing particularly on their ability to direct leukocyte migration.
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Affiliation(s)
- Catherine E Hughes
- Institute of Infection, Inflammation & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Robert J B Nibbs
- Institute of Infection, Inflammation & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
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72
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Affiliation(s)
- Isaac P Thomsen
- a Department of Pediatrics , Division of Pediatric Infectious Diseases and the Vanderbilt Vaccine Research Program, Vanderbilt University Medical Center , Nashville , Tennessee , USA
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73
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Thomsen IP, Liu GY. Targeting fundamental pathways to disrupt Staphylococcus aureus survival: clinical implications of recent discoveries. JCI Insight 2018. [PMID: 29515041 DOI: 10.1172/jci.insight.98216] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The emergence of community-associated methicillin-resistant Staphylococcus aureus during the past decade along with an impending shortage of effective antistaphylococcal antibiotics have fueled impressive advances in our understanding of how S. aureus overcomes the host environment to establish infection. Backed by recent technologic advances, studies have uncovered elaborate metabolic, nutritional, and virulence strategies deployed by S. aureus to survive the restrictive and hostile environment imposed by the host, leading to a plethora of promising antimicrobial approaches that have potential to remedy the antibiotic resistance crisis. In this Review, we highlight some of the critical and recently elucidated bacterial strategies that are potentially amenable to intervention, discuss their relevance to human diseases, and address the translational challenges posed by current animal models.
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Affiliation(s)
- Isaac P Thomsen
- Department of Pediatrics, Division of Pediatric Infectious Diseases, and Vanderbilt Vaccine Research Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - George Y Liu
- Division of Pediatric Infectious Diseases and Research Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
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74
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Staphylococcus aureus produces pain through pore-forming toxins and neuronal TRPV1 that is silenced by QX-314. Nat Commun 2018; 9:37. [PMID: 29295977 PMCID: PMC5750211 DOI: 10.1038/s41467-017-02448-6] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 11/30/2017] [Indexed: 12/22/2022] Open
Abstract
The hallmark of many bacterial infections is pain. The underlying mechanisms of pain during live pathogen invasion are not well understood. Here, we elucidate key molecular mechanisms of pain produced during live methicillin-resistant Staphylococcus aureus (MRSA) infection. We show that spontaneous pain is dependent on the virulence determinant agr and bacterial pore-forming toxins (PFTs). The cation channel, TRPV1, mediated heat hyperalgesia as a distinct pain modality. Three classes of PFTs-alpha-hemolysin (Hla), phenol-soluble modulins (PSMs), and the leukocidin HlgAB-directly induced neuronal firing and produced spontaneous pain. From these mechanisms, we hypothesized that pores formed in neurons would allow entry of the membrane-impermeable sodium channel blocker QX-314 into nociceptors to silence pain during infection. QX-314 induced immediate and long-lasting blockade of pain caused by MRSA infection, significantly more than lidocaine or ibuprofen, two widely used clinical analgesic treatments.
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75
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Rouha H, Weber S, Janesch P, Maierhofer B, Gross K, Dolezilkova I, Mirkina I, Visram ZC, Malafa S, Stulik L, Badarau A, Nagy E. Disarming Staphylococcus aureus from destroying human cells by simultaneously neutralizing six cytotoxins with two human monoclonal antibodies. Virulence 2017; 9:231-247. [PMID: 29099326 PMCID: PMC5955178 DOI: 10.1080/21505594.2017.1391447] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pathogenesis of Staphylococcus aureus is increasingly recognized to be driven by powerful toxins. Staphylococcus aureus employs up to six pore-forming toxins to subvert the human host defense and to promote bacterial invasion: alpha-hemolysin that disrupts epithelial and endothelial barriers and five leukocidins that lyse phagocytes involved in bacterial clearance. Previously, we described two human monoclonal antibodies (mAbs), ASN-1 that neutralizes alpha-hemolysin and four leukocidins (LukSF-PV, LukED, HlgAB, HlgCB), and ASN-2 that inactivates the 5th leukocidin, LukGH. In this study we tested the individual and combined effects of ASN-1 and ASN-2 in multiple in vitro models employing relevant human target cells. We found that diverse S. aureus isolates with different genetic backgrounds (based on MLST- and spa-typing) and antibiotic sensitivity (both MRSA and MSSA) displayed greatly different cytotoxin expression patterns influenced by the type of growth medium used. Both mAbs were required to fully prevent the lysis of human neutrophils exposed to the mixture of recombinant cytotoxins or native toxins present in the culture supernatants of S. aureus isolates. Flow cytometry confirmed the protective effects of ASN-1 + ASN-2 (known as ASN100) on granulocytes, monocytes, NK-cells and T-lymphocytes. ASN-1 alone preserved the integrity of a 3D-primary culture of human tracheal/bronchial mucociliary epithelial tissue infected with S. aureus. We conclude that simultaneous inhibition of alpha-hemolysin and five leukocidins by ASN100 blocks cytolytic activity of S. aureus towards human target cells in vitro.
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Affiliation(s)
- Harald Rouha
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Susanne Weber
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Philipp Janesch
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Barbara Maierhofer
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Karin Gross
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Ivana Dolezilkova
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Irina Mirkina
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Zehra C Visram
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Stefan Malafa
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Lukas Stulik
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Adriana Badarau
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
| | - Eszter Nagy
- a Arsanis Biosciences, Helmut-Qualtinger-Gasse 2, Campus Vienna Biocenter , Vienna , Austria
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76
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Balasubramanian D, Harper L, Shopsin B, Torres VJ. Staphylococcus aureus pathogenesis in diverse host environments. Pathog Dis 2017; 75:ftx005. [PMID: 28104617 DOI: 10.1093/femspd/ftx005] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/18/2017] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is an eminent human pathogen that can colonize the human host and cause severe life-threatening illnesses. This bacterium can reside in and infect a wide range of host tissues, ranging from superficial surfaces like the skin to deeper tissues such as in the gastrointestinal tract, heart and bones. Due to its multifaceted lifestyle, S. aureus uses complex regulatory networks to sense diverse signals that enable it to adapt to different environments and modulate virulence. In this minireview, we explore well-characterized environmental and host cues that S. aureus responds to and describe how this pathogen modulates virulence in response to these signals. Lastly, we highlight therapeutic approaches undertaken by several groups to inhibit both signaling and the cognate regulators that sense and transmit these signals downstream.
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Affiliation(s)
- Divya Balasubramanian
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Lamia Harper
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Bo Shopsin
- Department of Medicine, Division of Infectious Diseases, New York University School of Medicine, New York, NY 10016 USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
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77
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Functional classification of protein toxins as a basis for bioinformatic screening. Sci Rep 2017; 7:13940. [PMID: 29066768 PMCID: PMC5655178 DOI: 10.1038/s41598-017-13957-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/02/2017] [Indexed: 01/05/2023] Open
Abstract
Proteins are fundamental to life and exhibit a wide diversity of activities, some of which are toxic. Therefore, assessing whether a specific protein is safe for consumption in foods and feeds is critical. Simple BLAST searches may reveal homology to a known toxin, when in fact the protein may pose no real danger. Another challenge to answer this question is the lack of curated databases with a representative set of experimentally validated toxins. Here we have systematically analyzed over 10,000 manually curated toxin sequences using sequence clustering, network analysis, and protein domain classification. We also developed a functional sequence signature method to distinguish toxic from non-toxic proteins. The current database, combined with motif analysis, can be used by researchers and regulators in a hazard screening capacity to assess the potential of a protein to be toxic at early stages of development. Identifying key signatures of toxicity can also aid in redesigning proteins, so as to maintain their desirable functions while reducing the risk of potential health hazards.
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78
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Prince A, Wang H, Kitur K, Parker D. Humanized Mice Exhibit Increased Susceptibility to Staphylococcus aureus Pneumonia. J Infect Dis 2017; 215:1386-1395. [PMID: 27638942 DOI: 10.1093/infdis/jiw425] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/11/2016] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus is a highly successful human pathogen that has evolved in response to human immune pressure. The common USA300 methicillin-resistant S. aureus (MRSA) strains express a number of toxins, such as Panton-Valentine leukocidin and LukAB, that have specificity for human receptors. Using nonobese diabetic (NOD)-scid IL2Rγnull (NSG) mice reconstituted with a human hematopoietic system, we were able to discriminate the roles of these toxins in the pathogenesis of pneumonia. We demonstrate that expression of human immune cells confers increased severity of USA300 infection. The expression of PVL but not LukAB resulted in more-severe pulmonary infection by the wild-type strain (with a 30-fold increase in the number of colony-forming units/mL; P < .01) as compared to infection with the lukS/F-PV (Δpvl) mutant. Treatment of mice with anti-PVL antibody also enhanced bacterial clearance. We found significantly greater numbers (by 95%; P < .05) of macrophages in the airways of mice infected with the Δpvl mutant compared with those infected with the wild-type strain, as well as significantly greater expression of human tumor necrosis factor and interleukin 6 (84% and 51% respectively; P < .01). These results suggest that the development of humanized mice may provide a framework to assess the contribution of human-specific toxins and better explore the roles of specific components of the human immune system in protection from S. aureus infection.
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Affiliation(s)
- Alice Prince
- Department Pediatrics
- Department of Pharmacology, and
| | - Hui Wang
- Humanized Mouse Core Facility, Columbia Center for Translational Immunology, Columbia University, New York
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79
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Gillman AN, Breshears LM, Kistler CK, Finnegan PM, Torres VJ, Schlievert PM, Peterson ML. Epidermal Growth Factor Receptor Signaling Enhances the Proinflammatory Effects of Staphylococcus aureus Gamma-Toxin on the Mucosa. Toxins (Basel) 2017; 9:toxins9070202. [PMID: 28657583 PMCID: PMC5535149 DOI: 10.3390/toxins9070202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/02/2017] [Accepted: 06/09/2017] [Indexed: 12/27/2022] Open
Abstract
Staphylococcus aureus (S. aureus) produces many different exotoxins including the gamma-toxins, HlgAB and HlgCB. Gamma-toxins form pores in both leukocyte and erythrocyte membranes, resulting in cell lysis. The genes encoding gamma-toxins are present in most strains of S. aureus, and are commonly expressed in clinical isolates recovered from menstrual Toxic Shock Syndrome (mTSS) patients. This study set out to investigate the cytotoxic and proinflammatory effects of gamma-toxins on vaginal epithelial surfaces. We found that both HlgAB and HlgCB were cytotoxic to cultured human vaginal epithelial cells (HVECs) and induced cytokine production at sub-cytotoxic doses. Cytokine production induced by gamma-toxin treatment of HVECs was found to involve epidermal growth factor receptor (EGFR) signaling and mediated by shedding of EGFR ligands from the cell surface. The gamma-toxin subunits displayed differential binding to HVECs (HlgA 93%, HlgB 97% and HlgC 28%) with both components (HlgAB or HlgCB) required for maximum detectable binding and significant stimulation of cytokine production. In studies using full thickness ex vivo porcine vaginal mucosa, HlgAB or HlgCB stimulated a dose-dependent cytokine response, which was reduced significantly by inhibition of EGFR signaling. The effects of gamma-toxins on porcine vaginal tissue and cultured HVECs were validated using ex vivo human ectocervical tissue. Collectively, these studies have identified the EGFR-signaling pathway as a key component in gamma-toxin-induced proinflammatory changes at epithelial surfaces and highlight a potential therapeutic target to diminish toxigenic effects of S. aureus infections.
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Affiliation(s)
- Aaron N Gillman
- Department of Pharmacy, University of Tromsø, Tromsø 9019, Troms, Norway.
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Laura M Breshears
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
| | | | | | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
| | - Patrick M Schlievert
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | - Marnie L Peterson
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
- Extherid Biosciences, LLC., Jackson, WY 83001, USA.
- School of Pharmacy, University of Wyoming, Laramie, WY 82071, USA.
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80
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The Controversial C5a Receptor C5aR2: Its Role in Health and Disease. J Immunol Res 2017; 2017:8193932. [PMID: 28706957 PMCID: PMC5494583 DOI: 10.1155/2017/8193932] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/11/2017] [Indexed: 01/24/2023] Open
Abstract
After the discovery of the C5a receptor C5aR1, C5aR2 is the second receptor found to bind C5a and its des-arginine form. As a heptahelical G protein-coupled receptor but devoid of the intracellular Gα signal, C5aR2 is special and confusing. Ramifications and controversies about C5aR2 are under debate since its identification, from putative ligands and cellular localization to intracellular signals and pathological roles in inflammation and immunity. The ruleless and even conflicting pro- or anti-inflammatory role of C5aR2 in animal models of diverse diseases makes one bewildered. This review summarizes reports on C5aR2, tries to clear up available evidence on these four controversial aspects, and delineates C5aR2 function(s). It also summarizes available toolboxes for C5aR2 study.
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Seilie ES, Bubeck Wardenburg J. Staphylococcus aureus pore-forming toxins: The interface of pathogen and host complexity. Semin Cell Dev Biol 2017; 72:101-116. [PMID: 28445785 DOI: 10.1016/j.semcdb.2017.04.003] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/22/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
Abstract
Staphylococcus aureus is a prominent human pathogen capable of infecting a variety of host species and tissue sites. This versatility stems from the pathogen's ability to secrete diverse host-damaging virulence factors. Among these factors, the S. aureus pore-forming toxins (PFTs) α-toxin and the bicomponent leukocidins, have garnered much attention for their ability to lyse cells at low concentrations and modulate disease severity. Although many of these toxins were discovered nearly a century ago, their host cell specificities have only been elucidated over the past five to six years, starting with the discovery of the eukaryotic receptor for α-toxin and rapidly followed by identification of the leukocidin receptors. The identification of these receptors has revealed the species- and cell type-specificity of toxin binding, and provided insight into non-lytic effects of PFT intoxication that contribute to disease pathogenesis.
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Affiliation(s)
- E Sachiko Seilie
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, United States; Department of Microbiology, The University of Chicago, Chicago, IL 60637, United States
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82
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Spaan AN, van Strijp JAG, Torres VJ. Leukocidins: staphylococcal bi-component pore-forming toxins find their receptors. Nat Rev Microbiol 2017; 15:435-447. [PMID: 28420883 DOI: 10.1038/nrmicro.2017.27] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Staphylococcus aureus is a major bacterial pathogen that causes disease worldwide. The emergence of strains that are resistant to commonly used antibiotics and the failure of vaccine development have resulted in a renewed interest in the pathophysiology of this bacterium. Staphylococcal leukocidins are a family of bi-component pore-forming toxins that are important virulence factors. During the past five years, cellular receptors have been identified for all of the bi-component leukocidins. The identification of the leukocidin receptors explains the cellular tropism and species specificity that is exhibited by these toxins, which has important biological consequences. In this Review, we summarize the recent discoveries that have reignited interest in these toxins and provide an outlook for future research.
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Affiliation(s)
- András N Spaan
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, 430 East 29th Street, 10016 New York, USA
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83
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Janesch P, Rouha H, Weber S, Malafa S, Gross K, Maierhofer B, Badarau A, Visram ZC, Stulik L, Nagy E. Selective sensitization of human neutrophils to LukGH mediated cytotoxicity by Staphylococcus aureus and IL-8. J Infect 2017; 74:473-483. [PMID: 28237625 DOI: 10.1016/j.jinf.2017.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/14/2017] [Accepted: 02/17/2017] [Indexed: 01/03/2023]
Abstract
OBJECTIVES Staphylococcus aureus produces up to five bi-component leukocidins - LukSF-PV, gamma-hemolysins AB and CB, LukGH (LukAB) and LukED - to evade innate immunity by lysing phagocytic cells. Species specificity of these leukocidins limits the relevance of animal models, therefore we assessed their individual contribution using human neutrophils. METHODS Human polymorphonuclear leukocytes (PMNs) were activated with stimuli relevant during bacterial infections and sensitivity to recombinant leukocidins was measured in cell-viability assays. Leukocidin receptor expression was quantified by flow cytometry. RESULTS We observed greatly variable sensitivities of different PMN preparations towards LukGH. Activation of PMNs by lipopolysaccharide (LPS) or S. aureus culture supernatant (CS) lacking all leukocidins resulted in higher surface expression of CD11b, the LukGH receptor, and greatly enhanced the sensitivity towards LukGH, eliminating the variability observed with unstimulated cells. In contrast, CS induced a decrease in sensitivity of PMNs to the other four leukocidins and reduced surface staining for their cognate receptors (CXCR1, CXCR2, C5aR, C5L2). Delta-toxin and peptidoglycan mimicked the effect of CS. Moreover, IL-8, an important cytokine in neutrophil activation, also selectively increased LukGH sensitivity. Deletion of lukGH, but not other leukocidin genes, prevented PMN killing upon infection with USA300 CA-MRSA. CONCLUSION Inflammatory signals enhance the susceptibility of human PMNs to lysis by LukGH rendering this toxin dominant among the S. aureus leukocidins in vitro.
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84
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Koop G, Vrieling M, Storisteanu DML, Lok LSC, Monie T, van Wigcheren G, Raisen C, Ba X, Gleadall N, Hadjirin N, Timmerman AJ, Wagenaar JA, Klunder HM, Fitzgerald JR, Zadoks R, Paterson GK, Torres C, Waller AS, Loeffler A, Loncaric I, Hoet AE, Bergström K, De Martino L, Pomba C, de Lencastre H, Ben Slama K, Gharsa H, Richardson EJ, Chilvers ER, de Haas C, van Kessel K, van Strijp JAG, Harrison EM, Holmes MA. Identification of LukPQ, a novel, equid-adapted leukocidin of Staphylococcus aureus. Sci Rep 2017; 7:40660. [PMID: 28106142 PMCID: PMC5247767 DOI: 10.1038/srep40660] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/08/2016] [Indexed: 11/09/2022] Open
Abstract
Bicomponent pore-forming leukocidins are a family of potent toxins secreted by Staphylococcus aureus, which target white blood cells preferentially and consist of an S- and an F-component. The S-component recognizes a receptor on the host cell, enabling high-affinity binding to the cell surface, after which the toxins form a pore that penetrates the cell lipid bilayer. Until now, six different leukocidins have been described, some of which are host and cell specific. Here, we identify and characterise a novel S. aureus leukocidin; LukPQ. LukPQ is encoded on a 45 kb prophage (ΦSaeq1) found in six different clonal lineages, almost exclusively in strains cultured from equids. We show that LukPQ is a potent and specific killer of equine neutrophils and identify equine-CXCRA and CXCR2 as its target receptors. Although the S-component (LukP) is highly similar to the S-component of LukED, the species specificity of LukPQ and LukED differs. By forming non-canonical toxin pairs, we identify that the F-component contributes to the observed host tropism of LukPQ, thereby challenging the current paradigm that leukocidin specificity is driven solely by the S-component.
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Affiliation(s)
- Gerrit Koop
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands
| | - Manouk Vrieling
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Daniel M. L. Storisteanu
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke’s and Papworth Hospitals, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Laurence S. C. Lok
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke’s and Papworth Hospitals, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Tom Monie
- Medical Research Council Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, United Kingdom
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
| | - Glenn van Wigcheren
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Claire Raisen
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
| | - Xiaoliang Ba
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
| | - Nicholas Gleadall
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
| | - Nazreen Hadjirin
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
| | - Arjen J. Timmerman
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, 3584 CL Utrecht, The Netherlands
| | - Jaap A. Wagenaar
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, 3584 CL Utrecht, The Netherlands
- Central Veterinary Institute of Wageningen UR, 8200 AB Lelystad, The Netherlands
| | - Heleen M. Klunder
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands
| | - J. Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, EH25 9RG, Edinburgh, United Kingdom
| | - Ruth Zadoks
- Moredun Research Institute, Bush Loan, Penicuik EH26 0PZ, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, United Kingdom
| | - Gavin K. Paterson
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, United Kingdom
| | - Carmen Torres
- Área Bioquímica y Biología Molecular, Universidad de La Rioja, Madre de Dios 51, Logroño 26006, Spain
| | - Andrew S. Waller
- Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Anette Loeffler
- Department of Clinical Sciences and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, North Mymms, Hertfordshire AL9 7TA, United Kingdom
| | - Igor Loncaric
- Institute of Microbiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | - Armando E. Hoet
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
- Veterinary Public Health Program, College of Public Health, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
| | - Karin Bergström
- Department of Animal Health and Antimicrobial Strategies, SVA, SE-751 89 Uppsala, Sweden
| | - Luisa De Martino
- Department of Veterinary Medicine and Animal Production, Infectious Diseases Section, University of Naples “Federico II”, 80137 Naples, Italy
| | - Constança Pomba
- Interdisciplinary Centre of Research in Animal Health, Faculdade de Medicina Veterinária, Universidade de Lisboa, 1300-477 LISBOA, Portugal
| | - Hermínia de Lencastre
- Laboratório de Genética Molecular, Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB/UNL), Oeiras, Portugal
- Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, NY10065, USA
| | - Karim Ben Slama
- Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, 2092 Tunis, Tunisia
- Institut Supérieur des Sciences Biologiques Appliquées de Tunis, Université de Tunis El Manar, 2092 Tunis, Tunisia
| | - Haythem Gharsa
- Laboratoire de Microorganismes et Biomolécules actives, Département de Biologie, Faculté de Sciences de Tunis, 2092 Tunis, Tunisia
| | - Emily J. Richardson
- Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, UK
| | - Edwin R. Chilvers
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke’s and Papworth Hospitals, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Carla de Haas
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Kok van Kessel
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Jos A. G. van Strijp
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Ewan M. Harrison
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
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Zimmermann-Meisse G, Prévost G, Jover E. Above and beyond C5a Receptor Targeting by Staphylococcal Leucotoxins: Retrograde Transport of Panton-Valentine Leucocidin and γ-Hemolysin. Toxins (Basel) 2017; 9:toxins9010041. [PMID: 28117704 PMCID: PMC5308273 DOI: 10.3390/toxins9010041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/10/2017] [Accepted: 01/16/2017] [Indexed: 12/03/2022] Open
Abstract
Various membrane receptors associated with the innate immune response have recently been identified as mediators of the cellular action of Staphylococcus aureus leucotoxins. Two of these, the Panton–Valentine leucotoxin LukS-PV/LukF-PV and the γ-hemolysin HlgC/HlgB, bind the C5a complement-derived peptide receptor. These leucotoxins utilize the receptor to induce intracellular Ca2+ release from internal stores, other than those activated by C5a. The two leucotoxins are internalized with the phosphorylated receptor, but it is unknown whether they divert retrograde transport of the receptor or follow another pathway. Immunolabeling and confocal microscopic techniques were used to analyze the presence of leucotoxins in endosomes, lysosomes, endoplasmic reticulum, and Golgi. The two leucotoxins apparently followed retrograde transport similar to that of the C5a peptide-activated receptor. However, HlgC/HlgB reached the Golgi network very early, whereas LukS-PV/LukF-PV followed slower kinetics. The HlgC/HlgB leucotoxin remained in neutrophils 6 h after a 10-min incubation of the cells in the presence of the toxin with no signs of apoptosis, whereas apoptosis was observed 3 h after neutrophils were incubated with LukS-PV/LukF-PV. Such retrograde transport of leucotoxins provides a novel understanding of the cellular effects initiated by sublytic concentrations of these toxins.
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Affiliation(s)
- Gaëlle Zimmermann-Meisse
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), VBP EA7290, Institut de Bactériologie, Université de Strasbourg, 3 rue Koeberlé, F-67000 Strasbourg, France.
| | - Gilles Prévost
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), VBP EA7290, Institut de Bactériologie, Université de Strasbourg, 3 rue Koeberlé, F-67000 Strasbourg, France.
| | - Emmanuel Jover
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), VBP EA7290, Institut de Bactériologie, Université de Strasbourg, 3 rue Koeberlé, F-67000 Strasbourg, France.
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Structure and Function of the Two-Component Cytotoxins of Staphylococcus aureus - Learnings for Designing Novel Therapeutics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 966:15-35. [PMID: 28455832 DOI: 10.1007/5584_2016_200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus can produce up to five different bi-component cytotoxins: two gamma-hemolysins HlgAB and HlgCB, and leukocidins SF-PV (Panton Valentine leukocidin), ED (LukED) and GH (LukGH, also called LukAB). Their major function in S. aureus pathogenesis is to evade innate immunity by attacking phagocytic cells and to support bacterial growth by lysing red blood cells. The five cytotoxins display different levels of amino acid sequence conservation (30-82%), but all form a remarkably similar beta-barrel type pore structure (greatly resembling the mono-component toxin alpha-hemolysin) that inserts into the target cell membrane leading to necrotic cell death. This review provides an overview of the culmination of decades of research on the structure of these toxins, their unique sequence and structural features that helps to explain the observed functional differences, such as toxin potency towards different cell types and species, receptor specificity and formation of functional non-cognate toxin pairs. The vast knowledge accumulated in this field supports novel approaches and the design of therapeutics targeting these cytotoxins to tame virulence and fight S. aureus infections.
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Staphylococcus aureus Leukocidin LukED and HIV-1 gp120 Target Different Sequence Determinants on CCR5. mBio 2016; 7:mBio.02024-16. [PMID: 27965453 PMCID: PMC5156306 DOI: 10.1128/mbio.02024-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Leukocidin ED (LukED) is a bicomponent pore-forming toxin produced by Staphylococcus aureus that lyses host cells by targeting the chemokine receptors CC chemokine receptor type 5 (CCR5), CXCR1, CXCR2, and DARC. In addition to its role as a receptor for LukED, CCR5 is the major coreceptor for primary isolates of human immunodeficiency virus type 1 (HIV-1) and has been extensively studied. To compare how LukED and HIV-1 target CCR5, we analyzed their respective abilities to use CCR5/CCR2b chimeras to mediate cytotoxicity and virus entry. These analyses showed that the second and third extracellular loops (ECL) of CCR5 are necessary and sufficient for LukED to target the receptor and promote cell lysis. In contrast, the second ECL of CCR5 is necessary but not sufficient for HIV-1 infectivity. The analysis of CCR5 point mutations showed that glycine-163 is critical for HIV-1 infectivity, while arginine-274 and aspartic acid-276 are critical for LukED cytotoxicity. Point mutations in ECL2 diminished both HIV-1 infectivity and LukED cytotoxicity. Treatment of cells with LukED did not interfere with CCR5-tropic HIV-1 infectivity, demonstrating that LukED and the viral envelope glycoprotein use nonoverlapping sites on CCR5. Analysis of point mutations in LukE showed that amino acids 64 to 69 in the rim domain are required for CCR5 targeting and cytotoxicity. Taking the results together, this study identified the molecular basis by which LukED targets CCR5, highlighting the divergent molecular interactions evolved by HIV-1 and LukED to interact with CCR5. The bicomponent pore-forming toxins are thought to play a vital role in the success of Staphylococcus aureus as a mammalian pathogen. One of the leukocidins, LukED, is necessary and sufficient for lethality in mice. At the molecular level, LukED causes cell lysis through binding to specific cellular receptors. CCR5 is one of the receptors targeted by LukED and is the major coreceptor for CCR5-tropic HIV-1. While the molecular interaction of CCR5 and HIV-1 is well characterized, the means by which LukED interacts with CCR5 is less clear. In this study, we demonstrated that receptor specificity is conferred through unique interactions between key domains on CCR5 and LukE. Although HIV-1 and LukED target the same receptor, our data demonstrated that they interact with CCR5 differently, highlighting the molecular complexity of host-pathogen interactions.
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88
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LukMF' is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis. Sci Rep 2016; 6:37759. [PMID: 27886237 PMCID: PMC5123576 DOI: 10.1038/srep37759] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/31/2016] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal leukocidins in the pathogenesis of bovine S. aureus disease. We show that LukAB, in contrast to the γ-hemolysins, LukED, and LukMF′, was unable to kill bovine neutrophils, and identified CXCR2 as a bovine receptor for HlgAB and LukED. Furthermore, we assessed functional leukocidin secretion by bovine mastitis isolates and observed that, although leukocidin production was strain dependent, LukMF′ was most abundantly secreted and the major toxin killing bovine neutrophils. To determine the role of LukMF′ in bovine mastitis, cattle were challenged with high (S1444) or intermediate (S1449, S1463) LukMF′-producing isolates. Only animals infected with S1444 developed severe clinical symptoms. Importantly, LukM was produced in vivo during the course of infection and levels in milk were associated with the severity of mastitis. Altogether, these findings underline the importance of LukMF′ as a virulence factor and support the development of therapeutic approaches targeting LukMF′ to control S. aureus mastitis in cattle.
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Improved Protection in a Rabbit Model of Community-Associated Methicillin-Resistant Staphylococcus aureus Necrotizing Pneumonia upon Neutralization of Leukocidins in Addition to Alpha-Hemolysin. Antimicrob Agents Chemother 2016; 60:6333-40. [PMID: 27527081 DOI: 10.1128/aac.01213-16] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/06/2016] [Indexed: 12/31/2022] Open
Abstract
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), especially the USA300 pulsotype, is a frequent cause of skin and soft tissue infections and severe pneumonia. Despite appropriate antibiotic treatment, complications are common and pneumonia is associated with high mortality. S. aureus strains express multiple cytotoxins, including alpha-hemolysin (Hla) and up to five bicomponent leukocidins that specifically target phagocytic cells for lysis. CA-MRSA USA300 strains carry the genes for all six cytotoxins. Species specificity of the leukocidins greatly contributes to the ambiguity regarding their role in S. aureus pathogenesis. We performed a comparative analysis of the leukocidin susceptibility of human, rabbit, and mouse polymorphonuclear leukocytes (PMNs) to assess the translational value of mouse and rabbit S. aureus models. We found that mouse PMNs were largely resistant to LukSF-PV, HlgAB, and HlgCB and susceptible only to LukED, whereas rabbit and human PMNs were highly sensitive to all these cytotoxins. In the rabbit pneumonia model with a USA300 CA-MRSA strain, passive immunization with a previously identified human monoclonal antibody (MAb), Hla-F#5, which cross-neutralizes Hla, LukSF-PV, HlgAB, HlgCB, and LukED, provided full protection, whereas an Hla-specific MAb was only partially protective. In the mouse USA300 CA-MRSA pneumonia model, both types of antibodies demonstrated full protection, suggesting that Hla, but not leukocidin(s), is the principal virulence determinant in mice. As the rabbit recapitulates the high susceptibility to leukocidins characteristic of humans, this species represents a valuable model for assessing novel, cytotoxin-targeting anti-S. aureus therapeutic approaches.
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Badarau A, Rouha H, Malafa S, Battles MB, Walker L, Nielson N, Dolezilkova I, Teubenbacher A, Banerjee S, Maierhofer B, Weber S, Stulik L, Logan DT, Welin M, Mirkina I, Pleban C, Zauner G, Gross K, Jägerhofer M, Magyarics Z, Nagy E. Context matters: The importance of dimerization-induced conformation of the LukGH leukocidin of Staphylococcus aureus for the generation of neutralizing antibodies. MAbs 2016; 8:1347-1360. [PMID: 27467113 PMCID: PMC5058624 DOI: 10.1080/19420862.2016.1215791] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
LukGH (LukAB) is a potent leukocidin of Staphylococcus aureus that lyses human phagocytic cells and is thought to contribute to immune evasion. Unlike the other bi-component leukocidins of S. aureus, LukGH forms a heterodimer before binding to its receptor, CD11b expressed on professional phagocytic cells, and displays significant sequence variation. We employed a high diversity human IgG1 library presented on yeast cells to discover monoclonal antibodies (mAbs) neutralizing the cytolytic activity of LukGH. Recombinant LukG and LukH monomers or a LukGH dimer were used as capture antigens in the library selections. We found that mAbs identified with LukG or LukH as bait had no or very low toxin neutralization potency. In contrast, LukGH dimer-selected antibodies proved to be highly potent, and several mAbs were able to neutralize even the most divergent LukGH variants. Based on biolayer interferometry and mesoscale discovery, the high affinity antibody binding site on the LukGH complex was absent on the individual monomers, suggesting that it was generated upon formation of the LukG-LukH dimer. X-ray crystallography analysis of the complex between the LukGH dimer and the antigen-binding fragment of a very potent mAb (PDB code 5K59) indicated that the epitope is located in the predicted cell binding region (rim domain) of LukGH. The corresponding IgG inhibited the binding of LukGH dimer to target cells. Our data suggest that knowledge of the native conformation of target molecules is essential to generate high affinity and functional mAbs.
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Affiliation(s)
- Adriana Badarau
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Harald Rouha
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Stefan Malafa
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | | | | | | | | | | | - Srijib Banerjee
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | | | - Susanne Weber
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Lukas Stulik
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Derek T Logan
- c SARomics Biostructures AB , Medicon Village, Lund , Sweden
| | - Martin Welin
- c SARomics Biostructures AB , Medicon Village, Lund , Sweden
| | - Irina Mirkina
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Clara Pleban
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Gerhild Zauner
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Karin Gross
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | | | - Zoltán Magyarics
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
| | - Eszter Nagy
- a Arsanis Biosciences , Campus Vienna Biocenter, Vienna , Austria
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91
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Staphylococcus aureus Coordinates Leukocidin Expression and Pathogenesis by Sensing Metabolic Fluxes via RpiRc. mBio 2016; 7:mBio.00818-16. [PMID: 27329753 PMCID: PMC4916384 DOI: 10.1128/mbio.00818-16] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Staphylococcus aureus is a formidable human pathogen that uses secreted cytolytic factors to injure immune cells and promote infection of its host. Of these proteins, the bicomponent family of pore-forming leukocidins play critical roles in S. aureus pathogenesis. The regulatory mechanisms governing the expression of these toxins are incompletely defined. In this work, we performed a screen to identify transcriptional regulators involved in leukocidin expression in S. aureus strain USA300. We discovered that a metabolic sensor-regulator, RpiRc, is a potent and selective repressor of two leukocidins, LukED and LukSF-PV. Whole-genome transcriptomics, S. aureus exoprotein proteomics, and metabolomic analyses revealed that RpiRc influences the expression and production of disparate virulence factors. Additionally, RpiRc altered metabolic fluxes in the trichloroacetic acid cycle, glycolysis, and amino acid metabolism. Using mutational analyses, we confirmed and extended the observation that RpiRc signals through the accessory gene regulatory (Agr) quorum-sensing system in USA300. Specifically, RpiRc represses the rnaIII promoter, resulting in increased repressor of toxins (Rot) levels, which in turn negatively affect leukocidin expression. Inactivation of rpiRc phenocopied rot deletion and increased S. aureus killing of primary human polymorphonuclear leukocytes and the pathogenesis of bloodstream infection in vivo. Collectively, our results suggest that S. aureus senses metabolic shifts by RpiRc to differentially regulate the expression of leukocidins and to promote invasive disease. IMPORTANCE The bicomponent pore-forming leukocidins play pivotal roles in the ability of S. aureus to kill multiple host immune cells, thus enabling this pathogen to have diverse tissue- and species-tropic effects. While the mechanisms of leukocidin-host receptor interactions have been studied in detail, the regulatory aspects of leukocidin expression are less well characterized. Moreover, the expression of the leukocidins is highly modular in vitro, suggesting the presence of regulators other than the known Agr, Rot, and S. aureus exoprotein pathways. Here, we describe how RpiRc, a metabolite-sensing transcription factor, mediates the repression of two specific leukocidin genes, lukED and pvl, which in turn has complex effects on the pathogenesis of S. aureus Our findings highlight the intricacies of leukocidin regulation by S. aureus and demonstrate the involvement of factors beyond traditional virulence factor regulators.
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92
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Flammier S, Rasigade JP, Badiou C, Henry T, Vandenesch F, Laurent F, Trouillet-Assant S. Human Monocyte-Derived Osteoclasts Are Targeted by Staphylococcal Pore-Forming Toxins and Superantigens. PLoS One 2016; 11:e0150693. [PMID: 26934588 PMCID: PMC4774977 DOI: 10.1371/journal.pone.0150693] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/18/2016] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus is the leading cause of bone and joint infections (BJIs). Staphylococcal pathogenesis involves numerous virulence factors including secreted toxins such as pore-forming toxins (PFTs) and superantigens. The role of these toxins on BJI outcome is largely unknown. In particular, few studies have examined how osteoclasts, the bone-resorbing cells, respond to exposure to staphylococcal PFTs and superantigens. We investigated the direct impact of recombinant staphylococcal toxins on human primary mature monocyte-derived osteoclasts, in terms of cytotoxicity and cell activation with cell death and bone resorption assays, using macrophages of the corresponding donors as a reference. Monocyte-derived osteoclasts displayed similar toxin susceptibility profiles compared to macrophages. Specifically, we demonstrated that the Panton-Valentine leukocidin, known as one of the most powerful PFT which lyses myeloid cells after binding to the C5a receptor, was able to induce the death of osteoclasts. The archetypal superantigen TSST-1 was not cytotoxic but enhanced the bone resorption activity of osteoclasts, suggesting a novel mechanism by which superantigen-producing S. aureus can accelerate the destruction of bone tissue during BJI. Altogether, our data indicate that the diverse clinical presentations of BJIs could be related, at least partly, to the toxin profiles of S. aureus isolates involved in these severe infections.
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Affiliation(s)
- Sacha Flammier
- Centre International de Recherche en Infectiologie, INSERM U1111, Pathogenesis of staphylococcal infections, University of Lyon 1, Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, 103 grande rue de la Croix Rousse, 69004 Lyon, France
- * E-mail:
| | - Jean-Philippe Rasigade
- Centre International de Recherche en Infectiologie, INSERM U1111, Pathogenesis of staphylococcal infections, University of Lyon 1, Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, 103 grande rue de la Croix Rousse, 69004 Lyon, France
| | - Cédric Badiou
- Centre International de Recherche en Infectiologie, INSERM U1111, Pathogenesis of staphylococcal infections, University of Lyon 1, Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, 103 grande rue de la Croix Rousse, 69004 Lyon, France
| | - Thomas Henry
- Centre International de Recherche en Infectiologie, INSERM U1111, Inflammasome, bacterial infections and autoinflammatory diseases, University of Lyon 1, 21 avenue Tony Garnier, 69365 Lyon cedex 07, France
| | - François Vandenesch
- Centre International de Recherche en Infectiologie, INSERM U1111, Pathogenesis of staphylococcal infections, University of Lyon 1, Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, 103 grande rue de la Croix Rousse, 69004 Lyon, France
| | - Frédéric Laurent
- Centre International de Recherche en Infectiologie, INSERM U1111, Pathogenesis of staphylococcal infections, University of Lyon 1, Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, 103 grande rue de la Croix Rousse, 69004 Lyon, France
| | - Sophie Trouillet-Assant
- Centre International de Recherche en Infectiologie, INSERM U1111, Pathogenesis of staphylococcal infections, University of Lyon 1, Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, 103 grande rue de la Croix Rousse, 69004 Lyon, France
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93
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Kaufmann SH, Dorhoi A. Molecular Determinants in Phagocyte-Bacteria Interactions. Immunity 2016; 44:476-491. [DOI: 10.1016/j.immuni.2016.02.014] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 01/28/2016] [Accepted: 02/17/2016] [Indexed: 12/24/2022]
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94
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Chow SH, Deo P, Naderer T. Macrophage cell death in microbial infections. Cell Microbiol 2016; 18:466-74. [PMID: 26833712 DOI: 10.1111/cmi.12573] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/21/2016] [Accepted: 01/27/2016] [Indexed: 12/26/2022]
Abstract
Macrophages can respond to microbial infections with programmed cell death. The major cell death pathways of apoptosis, pyroptosis and necroptosis are tightly regulated to ensure adequate immune reactions to virulent and persistent invaders. Macrophage death eliminates the replicative niche of intracellular pathogens and induces immune attack. Not surprisingly, successful pathogens have evolved strategies to modulate macrophage cell death pathways to enable microbial survival and replication. Uncontrolled macrophage death can also lead to tissue damage, which may augment bacterial dissemination and pathology. In this review, we highlight how pathogens hijack macrophage cell death signals to promote microbial survival and immune evasion.
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Affiliation(s)
- Seong H Chow
- Department of Biochemistry and Molecular Biology and the Biomedicine Discovery Institute, Monash University, Clayton, 3800, VIC, Australia
| | - Pankaj Deo
- Department of Biochemistry and Molecular Biology and the Biomedicine Discovery Institute, Monash University, Clayton, 3800, VIC, Australia
| | - Thomas Naderer
- Department of Biochemistry and Molecular Biology and the Biomedicine Discovery Institute, Monash University, Clayton, 3800, VIC, Australia
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95
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Parker D, Ahn D, Cohen T, Prince A. Innate Immune Signaling Activated by MDR Bacteria in the Airway. Physiol Rev 2016; 96:19-53. [PMID: 26582515 DOI: 10.1152/physrev.00009.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Health care-associated bacterial pneumonias due to multiple-drug resistant (MDR) pathogens are an important public health problem and are major causes of morbidity and mortality worldwide. In addition to antimicrobial resistance, these organisms have adapted to the milieu of the human airway and have acquired resistance to the innate immune clearance mechanisms that normally prevent pneumonia. Given the limited efficacy of antibiotics, bacterial clearance from the airway requires an effective immune response. Understanding how specific airway pathogens initiate and regulate innate immune signaling, and whether this response is excessive, leading to host-induced pathology may guide future immunomodulatory therapy. We will focus on three of the most important causes of health care-associated pneumonia, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and review the mechanisms through which an inappropriate or damaging innate immune response is stimulated, as well as describe how airway pathogens cause persistent infection by evading immune activation.
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Affiliation(s)
- Dane Parker
- Departments of Pediatrics and Pharmacology, Columbia University, New York, New York
| | - Danielle Ahn
- Departments of Pediatrics and Pharmacology, Columbia University, New York, New York
| | - Taylor Cohen
- Departments of Pediatrics and Pharmacology, Columbia University, New York, New York
| | - Alice Prince
- Departments of Pediatrics and Pharmacology, Columbia University, New York, New York
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96
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Reyes-Robles T, Lubkin A, Alonzo F, Lacy DB, Torres VJ. Exploiting dominant-negative toxins to combat Staphylococcus aureus pathogenesis. EMBO Rep 2016; 17:428-40. [PMID: 26882549 DOI: 10.15252/embr.201540994] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/05/2016] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a human pathogen that relies on the subversion of host phagocytes to support its pathogenic lifestyle. S. aureus strains can produce up to five beta-barrel, bi-component, pore-forming leukocidins that target and kill host phagocytes. Thus, preventing immune cell killing by these toxins is likely to boost host immunity. Here, we describe the identification of glycine-rich motifs within the membrane-penetrating stem domains of the leukocidin subunits that are critical for killing primary human neutrophils. Remarkably, leukocidins lacking these glycine-rich motifs exhibit dominant-negative inhibitory effects toward their wild-type toxin counterparts as well as other leukocidins. Biochemical and cellular assays revealed that these dominant-negative toxins work by forming mixed complexes that are impaired in pore formation. The dominant-negative leukocidins inhibited S. aureus cytotoxicity toward primary human neutrophils, protected mice from lethal challenge by wild-type leukocidin, and reduced bacterial burden in a murine model of bloodstream infection. Thus, we describe the first example of staphylococcal bi-component dominant-negative toxins and their potential as novel therapeutics to combat S. aureus infection.
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Affiliation(s)
- Tamara Reyes-Robles
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Ashira Lubkin
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Francis Alonzo
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - D Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
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97
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do Vale A, Cabanes D, Sousa S. Bacterial Toxins as Pathogen Weapons Against Phagocytes. Front Microbiol 2016; 7:42. [PMID: 26870008 PMCID: PMC4734073 DOI: 10.3389/fmicb.2016.00042] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/11/2016] [Indexed: 12/31/2022] Open
Abstract
Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favor microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signaling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.
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Affiliation(s)
- Ana do Vale
- Host Interaction and Response, Instituto de Investigação e Inovação em Saúde, Universidade do PortoPorto, Portugal; Group of Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular, Universidade do PortoPorto, Portugal
| | - Didier Cabanes
- Host Interaction and Response, Instituto de Investigação e Inovação em Saúde, Universidade do PortoPorto, Portugal; Group of Molecular Microbiology, Instituto de Biologia Molecular e Celular, Universidade do PortoPorto, Portugal
| | - Sandra Sousa
- Host Interaction and Response, Instituto de Investigação e Inovação em Saúde, Universidade do PortoPorto, Portugal; Group of Molecular Microbiology, Instituto de Biologia Molecular e Celular, Universidade do PortoPorto, Portugal
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98
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Abstract
PURPOSE OF REVIEW Staphylococcus aureus is the most common cause of skin and soft tissue infections (SSTI) in the United States and elsewhere. Recurrent infections occur frequently in patients with S. aureus SSTI, underscoring the need to better understand the nature of protective immunity against these infections. Here, we review recent findings concerning the host factors that predispose to S. aureus SSTI. RECENT FINDINGS Recurrent infections occur in nearly half of all patients with S. aureus SSTI. Epidemiologic and environmental factors, such as exposure to healthcare, age, and household contacts with S. aureus SSTI, and contaminated household fomites are associated with recurrence. The majority of the population has evidence of antistaphylococcal antibodies, but whether these are protective remains enigmatic. In contrast, recent clinical and experimental findings clearly highlight the critical roles of innate and T cell-mediated immunity in defense against these infections. S. aureus interferes with innate and adaptive immunity by a number of recently elucidated mechanisms. SUMMARY Recurrent S. aureus SSTIs are common, suggesting incomplete or absent protective immunity among these patients. Our understanding of protective immunity against recurrent infections is incomplete, and further basic and translational investigation is urgently needed to design strategies to prevent and treat these infections.
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Reyes-Robles T, Torres VJ. Staphylococcus aureus Pore-Forming Toxins. Curr Top Microbiol Immunol 2016; 409:121-144. [PMID: 27406190 DOI: 10.1007/82_2016_16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Staphylococcus aureus (S. aureus) is a formidable foe equipped with an armamentarium of virulence factors to thwart host defenses and establish a successful infection. Among these virulence factors, S. aureus produces several potent secreted proteins that act as cytotoxins, predominant among them the beta-barrel pore-forming toxins. These toxins play several roles in pathogenesis, including disruption of cellular adherens junctions at epithelial barriers, alteration of intracellular signaling events, modulation of host immune responses, and killing of eukaryotic immune and non-immune cells. This chapter provides an updated overview on the S. aureus beta-barrel pore-forming cytotoxins, the identification of toxin receptors on host cells, and their roles in pathogenesis.
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Affiliation(s)
- Tamara Reyes-Robles
- Department of Microbiology, Microbial Pathogenesis Program, New York University School of Medicine, 522 First Avenue, Smilow Research Building, Room 1010, New York, NY, 10016, USA
| | - Victor J Torres
- Department of Microbiology, Microbial Pathogenesis Program, New York University School of Medicine, 522 First Avenue, Smilow Research Building, Room 1010, New York, NY, 10016, USA.
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100
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Melehani JH, Duncan JA. Inflammasome Activation Can Mediate Tissue-Specific Pathogenesis or Protection in Staphylococcus aureus Infection. Curr Top Microbiol Immunol 2016; 397:257-82. [PMID: 27460814 DOI: 10.1007/978-3-319-41171-2_13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Staphylococcus aureus is a Gram-positive coccus that interacts with human hosts on a spectrum from quiet commensal to deadly pathogen. S. aureus is capable of infecting nearly every tissue in the body resulting in cellulitis, pneumonia, osteomyelitis, endocarditis, brain abscesses, bacteremia, and more. S. aureus has a wide range of factors that promote infection, and each site of infection triggers a different response in the human host. In particular, the different patterns of inflammasome activation mediate tissue-specific pathogenesis or protection in S. aureus infection. Although still a nascent field, understanding the unique host-pathogen interactions in each infection and the role of inflammasomes in mediating pathogenesis may lead to novel strategies for treating S. aureus infections. Reviews addressing S. aureus virulence and pathogenesis (Thammavongsa et al. 2015), as well as epidemiology and pathophysiology (Tong et al. 2015), have recently been published. This review will focus on S. aureus factors that activate inflammasomes and their impact on innate immune signaling and bacterial survival.
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Affiliation(s)
- Jason H Melehani
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joseph A Duncan
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. .,Department of Medicine, Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. .,Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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